bluuebunny/crossref_metadata_2025 huggingface dataset:
Salvage Treatment of Metastatic Breast Cancer with Docetaxel and Carboplatin
Authors: Mavroudis D. , Alexopoulos A. , Malamos N. , Ardavanis A. , Kandylis C. , Stavrinidis E. , Kouroussis Ch. , Agelaki S. , Androulakis N. , Bozionelou V. , Georgoulias V.
Published: April 2003

Objectives: To evaluate the efficacy and safety of docetaxel in combination with carboplatin as salvage treatment in women with metastatic breast cancer (MBC). Patients and Methods: Chemotherapy-pretreated women with MBC were treated with docetaxel 75 mg/m2 as 1-hour i.v. infusion followed by carboplatin AUC 6 mg/ml·min, using the Calvert’s formula, as 30-min i.v. infusion. Cycles were repeated on an outpatient basis every 3 weeks. Results: Thirty-six patients received a total of 210 chemotherapy cycles (median 6 cycles/patient). All but one patient had previously received anthracyclines for the treatment of metastatic disease and half of the patients had failed to respond to front-line treatment. Twenty-eight (78%) patients had visceral disease. On an intention-to-treat analysis there were three (8%) complete and 19 (53%) partial responses for an overall response rate of 61% (95% CI: 45.2–77.0%). The response rate was 44% (2 CRs, 6 PRs) among 18 patients who had progressive or stable disease as best response to front-line treatment. The median duration of response was 8 months, the median time to tumor progression 10 months, and the probability of 1-year survival 66%. Grade 3–4 neutropenia was the main hematologic toxicity occurring in 16 (45%) patients or 36 (17%) cycles. Seven (19%) patients developed 8 (4%) febrile neutropenic episodes. Grade 3 thrombocytopenia occurred in 4 (11%) patients or 6 (3%) cycles. Non-hematologic toxicity was generally mild. G-CSF was used in 19 (53%) patients or 134 (64%) cycles. There was one sudden death possibly related to the treatment. Conclusion: The docetaxel-carboplatin combination is an active outpatient salvage regimen for the treatment of women with MBC relapsing or not responding to anthracycline-based front-line therapy.
Preoperatively Irradiated Rectal Carcinoma: Analysis of the Histopathologic Response and Predictive Value of Proliferating Cell Nuclear Antigen Immunostaining
Authors: Díez M. , Ramos P. , Medrano M.J. , Mugüerza J.M. , Villeta R. , Lozano O. , Escribano J. , Noguerales F. , Ruíz A. , Granell J.
Published: April 2003

Objectives: To investigate the relationship between the histopathologic effects of preoperative chemoradiotherapy in rectal cancer and the proteins, proliferating cell nuclear antigen (PCNA) and p53. Methods: Samples from 73 tumors were examined. The histopathologic effects observed in the resected specimens induced by preoperative chemoradiotherapy were correlated with the inmunohistochemical expression of PCNA and p53 in biopsies obtained by rectoscopy before chemoradiotherapy. Results: Thirty-five tumors showed a high PCNA index (48%). Nuclear accumulation of p53 protein was detected in 53 tumors (72%). Specimens were assigned one of four grades based on the amount of residual viable tumor. Three neoplasms (4%) showed complete regression; 8 other carcinomas (11%) showed only small numbers of tumor cells scattered within the field of stromal reaction. In these cases, it was considered that the tumor had responded significantly to radiotherapy. Tumors with a high PCNA index responded to chemoradiotherapy more frequently (8/35; 72%) than tumors with a low index (3/38; 43%) (p = 0.07). p53-negative tumors responded more frequently (4/20; 20%) than positive tumors (7/53; 13.2%) (p = 0.50). When pathologic and immunohistochemical characteristics of the tumors were included in a logistic regression model, only high PCNA index (odds ratio 5.35, 95% confidence interval 1.07–26.7) (p = 0.04) was significantly associated with the histologic response to preoperative chemoradiotherapy. Conclusion: High proliferative activity of rectal cancer, as determined by PCNA immunostaining, is predictive of the response to preoperative chemoradiotherapy.
Altered Expression of Cardiac Ankyrin Repeat Protein and Its Homologue, Ankyrin Repeat Protein with PEST and Proline-Rich Region, in Atrophic Muscles in Amyotrophic Lateral Sclerosis
Authors: Nakamura Kyoko , Nakada Chisato , Takeuchi Kengo , Osaki Mitsuhiko , Shomori Kohei , Kato Shinsuke , Ohama Eisaku , Sato Kenzo , Fukayama Masashi , Mori Shigeo , Ito Hisao , Moriyama Masatsugu
Published: April 2003

Objectives: Cardiac ankyrin repeat protein, CARP, is a protein that is restrictedly expressed in the heart but barely expressed in skeletal muscles. Since CARP is induced by pressure overload to the heart, it is proposed to be a genetic marker for cardiac hypertrophy. We recently identified a novel protein, ankyrin repeat protein with PEST and proline-rich region (ARPP), which is homologous to CARP and is preferentially expressed in type 1 skeletal muscle fibers (cf. slow fibers). We also found that both ARPP and CARP expression is induced in experimentally denervated skeletal muscles in mice. Based on these findings, we hypothesized that their expression may be induced in skeletal muscles in neurodegenerating disease. This work aimed to determine the expression pattern of ARPP and CARP in amyotrophic lateral sclerosis (ALS). Methods: In this study, we immunohistochemically analyzed the expression of ARPP and CARP in skeletal muscles of 9 ALS cases. Results: We found that CARP was aberrantly expressed in atrophic skeletal muscle fibers in ALS. Although ARPP-positive fibers were randomly scattered in a checkerboard-like pattern in normal skeletal muscle, this pattern was absent in ALS muscles. Furthermore, we also found that ARPP was expressed in fast myosin heavy chain-positive fibers (cf. type 2 fiber). Conclusion: These findings suggest that type-specific expression patterns of ARPP and CARP are altered in skeletal muscles of ALS.
Effect of Glycyrrhizin, an Active Component of Licorice Roots, on HIV Replication in Cultures of Peripheral Blood Mononuclear Cells from HIV-Seropositive Patients
Authors: Sasaki Hidetaka , Takei Miwa , Kobayashi Makiko , Pollard Richard B. , Suzuki Fujio
Published: April 2003

The effect of glycyrrhizin (GR) on HIV replication in cultures of peripheral blood mononuclear cells (PBMC) from HIV-infected patients was investigated. After the depletion of CD8+ T cells, PBMC from HIV+ patients (patient PBMC) and PBMC from healthy donors (healthy PBMC) were cocultured in the presence or absence of GR (100 µg/ml) for 21 days. In cultures of 13 of 42 samples of patient PBMC (13/42, 31%), GR inhibited more than 90% of HIV replication. Among 42 samples of patient PBMC, 20 were identified to be infected with a non-syncytium-inducing variant of HIV (NSI-HIV), 15 with a syncytium-inducing variant of HIV (SI-HIV), and the remaining 7 were classified as cells infected with SI-HIV and/or NSI-HIV. GR inhibited more than 90% of HIV replication in cultures of 12 patient PBMC samples infected with NSI-HIV (12/20, 60%). In patient PBMC infected with SI-HIV, GR inhibited HIV replication in only 1 patient (1/15, 7%). In cultures of patient PBMC, GR induced the production of CC chemokine ligand (CCL)4 and CCL5 in a dose-dependent manner. When the assay was performed in PBMC cultures supplemented with a mixture of monoclonal antibodies for CCL4 and CCL5, no evidence of anti-HIV activity of GR was found. These results indicate that GR has the potential to inhibit NSI-HIV replication in patient PBMC cultures by inducing the production of β-chemokines.
Stressful Life Events, Social Support, Attachment Security and Alexithymia in Vitiligo
Authors: Picardi A. , Pasquini P. , Cattaruzza M.S. , Gaetano P. , Melchi C.F. , Baliva G. , Camaioni D. , Tiago A. , Abeni D. , Biondi M.
Published: April 2003

Background: It has often been suggested that stress might trigger vitiligo. However, only one study supported this hypothesis, and no study explored the role of other personality or social factors. Methods: Out-patients experiencing a recent onset or exacerbation of vitiligo (n = 31) were compared with out-patients with skin conditions in which psychosomatic factors are commonly were regarded as negligible (n = 116). Stressful events during the last 12 months were assessed with Paykel’s Interview for Recent Life Events. Attachment style, alexithymia and social support were assessed with the ‘Experiences in Close Relationships’ questionnaire, the Toronto Alexithymia Scale (TAS-20), and the Multidimensional Scale of Perceived Social Support, respectively. Results: Cases and controls did not differ regarding the total number of events and the number of undesirable, uncontrollable or major events. Three or more uncontrollable events had occurred more frequently among cases than controls. Perceived social support was lower in cases than in controls. Cases scored higher than controls on anxious attachment, tended towards higher scores on avoidant attachment and were classified more often as insecure. Cases scored higher than controls on the TAS-20 and were classified more often as alexithymic or borderline alexithymic. The occurrence of many uncontrollable events, alexithymia and anxious attachment were associated with vitiligo also in multiple logistic regression analysis. Conclusions: These findings suggest that vulnerability to vitiligo is not increased by stressful events, except for many uncontrollable events. Alexithymia, insecure attachment and poor social support appear to increase susceptibility to vitiligo, possibly through deficits in emotion regulation or reduced ability to cope effectively with stress.
Effects of a Supportive-Expressive Group Intervention on Long-Term Psychosocial Adjustment in HIV-Infected Gay Men
Authors: Weiss Jeffrey J. , Mulder Cornelis L. , Antoni Michael H. , de Vroome Ernest M.M. , Garssen Bert , Goodkin Karl
Published: April 2003

Background: This study compared the effects of a supportive-expressive group intervention (GI) with an educational control condition (EC) on long-term psychosocial adjustment in gay men with HIV infection. Method: Subjects (n = 85) were randomized after stratification for disease stage and use of antiretroviral medication. GI consisted of 4 months of weekly group sessions followed by 5 monthly maintenance sessions plus written educational material, whereas the EC subjects received educational material only. Results: There were no between-group differences in effects on distress, coping or social support in analyses examining 4 time points over 15 months. Both conditions decreased in distress over time on the Hopkins Symptom Checklist and Beck Depression Inventory. Conclusions: Several explanations are offered for the reason why no additional benefit of the GI was found on outcome measures studied when compared with the EC condition and recommendations are made for future psychosocial intervention research with HIV-infected persons.
Flares in Patients with Systemic Lupus erythematosus Are Associated with Daily Psychological Stress
Authors: Pawlak Cornelius R. , Witte Torsten , Heiken Hans , Hundt Matthias , Schubert Jörg , Wiese Birgitt , Bischoff-Renken Annette , Gerber Katrin , Licht Birgit , Goebel Marion U. , Heijnen Cobi J. , Schmidt Reinhold E. , Schedlowski Manfred
Published: April 2003

Background: The aetiology of systemic lupus erythematosus (SLE) remains unclear. Clinical observations and a small number of studies performed so far suggest an association between psychological stress and self-reported symptoms of SLE patients. This longitudinal study was designed to investigate whether daily psychological stress is associated with flares in SLE patients, measured by clinical and laboratory parameters. Methods: Female SLE patients (n = 41) were followed over a period of six months. Daily stress was monitored by a hand-held PC diary programmed with 44 items based on standardized measures and clinical experience. Once every four weeks patients visited the outpatient clinic for medical evaluation. Disease activity was evaluated using the European Consensus Lupus Activity Measurement (ECLAM), laboratory parameters, and intake of steroids. Results: Classification and regression tree (CART) patient-wise analyses revealed that SLE patients with vs. without flares using complement and ECLAM as activity measures show greater negative self-ratings in mood, and social duties (p < 0.01). In addition, mixed model analysis of variance showed that daily hassles with social relationships were significantly associated with flares in SLE measured by an increase in steroid medication >5mg/d (p < 0.01). Conclusions: These results suggest that psychological stress is associated with flares in SLE. Particularly daily stress with social relationships and social duties may be factors to be related to the course of disease activity in SLE.
The Problem of the Placebo Response in Clinical Trials for Psychiatric Disorders: Culprits, Possible Remedies, and a Novel Study Design Approach
Authors: Fava Maurizio , Evins A. Eden , Dorer David J. , Schoenfeld David A.
Published: April 2003

The placebo response is a major issue in clinical trials for psychiatric disorders. Possible contributing factors to this problem include diagnostic misclassification, issues concerning inclusion/exclusion criteria, outcome measures’ lack of sensitivity to change, measurement errors, poor quality of data entry and verification, waxing and waning of the natural course of illness, regression toward the mean phenomenon, patient and clinician expectations about the trial, study design issues, non-specific therapeutic effects, and high attrition. Over the past few decades, researchers have attempted to reduce the placebo effect in a variety of ways. Unfortunately, approaches with very little or no benefit have included restricting enrollment to selected populations, rater training, requirement of same rater, and placebo lead-in phases. Some benefits, although often marginal, have been derived from standardizing diagnostic procedures, managing clinicians’ overestimation of change, simplification of study visits and assessments, minimizing non-specific, therapeutic effects, extending trial duration, reducing number of sites, increasing the sensitivity of outcome measures, and reducing the number of treatment arms. Thus far, there has been no attempt to develop new study designs aimed at reducing the placebo effect. We are proposing a novel study design, called ‘Sequential Parallel Comparison Design’, suitable for double-blind, placebo-controlled trials in psychiatric disorders. This design is aimed at reducing both the overall placebo response rate and the sample size required for such trials. Its usefulness in clinical research needs to be tested empirically. If this study design were to be found to meet its stated goals, this could markedly facilitate the process of clinical development of new compounds for the treatment of psychiatric disorders.
Stem Cells and Tissue Engineering: Prospects for Regenerating Tissues in Dental Practice
Authors: Thesleff Irma , Tummers Mark
Published: April 2003

In general, human tissues have a very limited potential to regenerate. However, recent progress in stem cell research and in tissue engineering promises novel prospects for tissue regeneration in dental practice in the future. Stem cells have been discovered in many adult tissues, including teeth, and stem cells from embryos have the potential to form all adult tissues. Embryonic stem cells can now be cultured and even produced from adult cells by the nuclear transfer method. Due to the rapid progress of research in molecular biology, particularly in the field of developmental biology, we are now starting to understand at the level of genes and molecules how the development of dental tissues is regulated. For instance, specific signal molecules have been identified which regulate the development of teeth and bones from progenitor cells. This information is already being used for the generation of dentoalveolar tissues in vitro and in vivo. Could we perhaps grow new enamel, dentine, periodontal ligament, bone, or even whole new teeth for our patients in the future?
CYP2E1 and Clinical Features in Alcoholics
Authors: Nakamura Kazuhiko , Iwahashi Kazuhiko , Ameno Kiyoshi , Sekine Yoshimoto , Suzuki Katsuaki , Minabe Yoshio , Mori Norio
Published: April 2003

It is known that P-4502E1 metabolizes both ethanol and acetaldehyde, and that it can be induced after birth by inducers such as ethanol. Genetic polymorphisms in the 5′-flanking region change its transcriptional regulation. Persons who are either hetereozygous or mutant homozygous for CYP2E1 (C1/C2 or C2/C2) can drink much more alcohol than persons who are normal homozygous for CYP2E1 (C1/C1) among those whose aldehyde dehydrogenase 2 genotype is heterozygous. Subjects were composed of 52 Japanese alcoholics. The alcoholics having no C2 (group 1) and the alcoholics having C2 (group 2) were compared with each other with respect to their clinical characteristics: family history, past history, alcohol-related symptoms, complications, social disabilities, self-consciousness and short alcohol dependence date. In the social disabilities, the genotypes of CYP2E1 (C1/C2 or C2/C2) showed significantly more cases of guilts (p < 0.05). In regard to liver disease or self-consciousness, this was at a trend level (p = 0.08). We have shown that the genotypes of CYP2E1 are associated with clinical features of alcoholics.
L-Carnitine Decreases Severity and Type of Fatigue Induced by Interferon-α in the Treatment of Patients with Hepatitis C
Authors: Neri Sergio , Pistone Giovanni , Saraceno Barbara , Pennisi Giovanni , Luca Salvatore , Malaguarnera Mariano
Published: April 2003

Background: Hepatitis C virus (HCV) is one of the major agents of chronic hepatitis and liver disease worldwide. Infection with HCV leads to chronic hepatitis in about 80% of the cases. The most used treatment is based on interferon (IFN)-α, which is effective in less than 50% of patients; however, a high proportion of responders may relapse after interferon withdrawal. Fatigue is a common complaint in patients with liver disease. The aim of our study was to evaluate the efficacy of carnitine on IFN-induced fatigue in subjects with chronic hepatitis C. Patients and Methods: We studied 50 patients (30 males and 20 females) with chronic hepatitis C. Chronic hepatitis was diagnosed by determination of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels (at least 2-fold upper normal values for 1 year). Our study series was divided into two groups and matched as to number, age, sex, as well as grade and duration of disease. Group 1, composed of 25 patients, was treated with leucocytic IFN-α at a dosage of 3 million IU thrice a week; group 2 (25 patients) was treated with the same protocol as group 1, but was also administered carnitine 2 g per os daily. Patients’ response was evaluated on the basis of serum levels of AST and ALT as well as liver functions; fatigue was evaluated by Wessely and Powell scores. All patients studied were tested before treatment and then 1, 3 and 6 months after the beginning of IFN administration. Results: The difference of physical fatigue between the two groups after 1 month of therapy was significant (p < 0.01) for patients treated with carnitine. This significance continued at the end of month 3 (p < 0.01). With reference to mental fatigue, the comparison between the two groups showed a significant difference for group 2 after 1 month (p < 0.01). Finally, with respect to the fatigue severity, the comparison between the two groups showed that after 1 and 3 months of therapy, fatigue was significantly less severe in group 2 than group 1 (p < 0.0005). Conclusions: If we take into account baseline values of mental and physical fatigue as well as the severity of this symptom in our study series, one observes that therapy with IFN alone induces fatigue in the majority of cases after 1 and 3 months, while at month 6, the values decrease. In contrast, patients treated with IFN + carnitine show a marked and early significant reduction of fatigue levels. These data suggest that the greater energetic substrate utilised by group 2 patients may in some way provide a better response of the patients to this side-effect. Abnormalities of neurotransmission concerning serotonine seem involved in the genesis of depression and fatigue. In addition, depression and fatigue commonly occur together, and the former is the most commonly observed symptom in patients with chronic fatigue syndrome.
Acoustic and Perceptual Indicators of Normal and Pathological Voice
Authors: Muñoz J. , Mendoza E. , Fresneda M.D. , Carballo G. , López P.
Published: April 2003

The aim of this study was to obtain acoustic correlates to vocal quality of a group of men and women with and without voice disorders, based on evaluations of a group of judges experienced in the field of vocal rehabilitation. In male subjects, perceptual evaluation of normal, hoarse and rough voice qualities was related to the following acoustic features: frequency perturbation measures (JITA, RAP, and SPPQ), amplitude perturbation (SAPQ and VAM), soft phonation index (SPI) and fundamental frequency tremor intensity (FTRI). While these measures presented normal values for normal voice, hoarseness showed some deviations in perturbation frequency variables and very high SPI values, while rough voice showed deviations in all the measures. Qualities of female voices were perceived as normal, breathy and hoarse, but the acoustic correlates of these qualities were less conclusive.
Central Role of Connexin40 in the Propagation of Electrically Activated Vasodilation in Mouse Cremasteric Arterioles In Vivo
Authors: Figueroa Xavier F. , Paul David L. , Simon Alexander M. , Goodenough Daniel A. , Day Kathy H. , Damon David N. , Duling Brian R.
Published: April 2003

When a short segment of arteriole is stimulated, vasomotor responses spread bidirectionally along the vessel axis purportedly via gap junctions. We used connexin40 knockout (Cx40
−/−
) mice to study vasomotor responses induced by 10-second trains of electrical stimulation (30 Hz, 1 ms, 30 to 50 V) in 2nd or 3rd order arterioles of the cremaster muscle. Measurements were made at the stimulation site (local) and at conducted sites (500, 1000, and 2000 μm upstream). In wild-type (Cx40
+/+
) animals, electrical stimulation evoked a local vasoconstriction and a conducted vasodilation that spread very rapidly along the vessel length without detectable decay. In Cx40
−/−
mice, the conducted dilation was converted into either vasoconstriction or a slowly developing vasodilation that decayed along the vessel length. Tetrodotoxin (TTX, 1 μmol/L) had no effect on the local vasoconstriction in either Cx40
+/+
or Cx40
−/−
mice, but enhanced the conducted vasodilation in Cx40
+/+
animals. In Cx40
−/−
mice, TTX abolished the conducted vasoconstriction when present and revealed a small vasodilation that decayed with distance. In the group of Cx40
−/−
mice in which electrical stimulation elicited a conducted vasodilation, TTX had no effect. Immunocytochemistry revealed Cx40 only in the endothelial layer of arterioles from Cx40
+/+
mice and complete elimination of this connexin in the Cx40
−/−
animals. These results indicate that focal current stimulation causes vasoconstriction by a combination of perivascular nerve stimulation and smooth muscle activation. Moreover, electrical stimulation activates a nonneuronal, Cx40-dependent vasodilator response that spreads along the vessel length without decay.
Ets-1 and Ets-2 Transcription Factors Are Essential for Normal Coronary and Myocardial Development in Chicken Embryos
Authors: Lie-Venema Heleen , Gittenberger-de Groot Adriana C. , van Empel Louis J.P. , Boot Marit J. , Kerkdijk Henri , de Kant Eric , DeRuiter Marco C.
Published: April 2003

In the development of a functional myocardium and formation of the coronary vasculature, epicardium-derived cells play an essential role. The proepicardial organ contributes to the developing coronary system by delivering mural cells to the endothelium-lined vessels. In search of genes that regulate the behavior of (pro)epicardial cells, the Ets-1 and Ets-2 transcription factors stand out as strong candidates. In the present study, the hypothesis that Ets transcription factors have a role in proper coronary and myocardial development was tested via antisense technology, by targeting
Ets-1
and
Ets-2
mRNAs to downregulate protein expression in chicken embryos. The results suggest that hereby the development of the coronary system is hampered, primarily by defects in the process of epithelial-mesenchymal transformation of the mesothelia of the primary and secondary heart fields. This was indicated by a lack of periarterial and epicardial mesenchyme, of peripheral coronary smooth muscle cells, and changes in myocardial morphology. A defect in myocardial perfusion caused by the absence of one or both coronary ostia seems to be “solved” by the development of numerous small fistulae connecting the ventricular lumen with the subepicardially located coronary vessels. The presence of coronary vascular aberrations in the antisense-
Ets
phenotype enabled us for the first time to study abnormal coronary development in a model that is not lethal to the embryo.
Myocytes Die by Multiple Mechanisms in Failing Human Hearts
Authors: Kostin Sawa , Pool Lieven , Elsässer Albrecht , Hein Stefan , Drexler Hannes C.A. , Arnon Eyal , Hayakawa Yukihiro , Zimmermann René , Bauer Erwin , Klövekorn Wolf-Peter , Schaper Jutta
Published: April 2003

We tested the hypothesis that myocyte loss in failing human hearts occurs by different mechanisms: apoptosis, oncosis, and autophagic cell death. Explanted hearts from 19 patients with idiopathic dilated cardiomyopathy (EF≤20%) and 7 control hearts were analyzed. Myocyte apoptosis revealed by caspase-3 activation and TUNEL staining occurred at a rate of 0.002±0.0005% (
P
<0.05 versus control) and oncosis assessed by complement 9 labeling at 0.06±0.001% (
P
<0.05). Cellular degeneration including appearance of ubiquitin containing autophagic vacuoles and nuclear disintegration was present at the ultrastructural level. Nuclear and cytosolic ubiquitin/protein accumulations occurred at 0.08±0.004% (
P
<0.05). The ubiquitin-activating enzyme E1 and the ligase E3 were not different from control. In contrast, ubiquitin mRNA levels were 1.8-fold (
P
<0.02) elevated, and the conjugating enzyme E2 was 2.3-fold upregulated (
P
<0.005). The most important finding, however, is the 2.3-fold downregulation of the deubiquitination enzyme isopeptidase-T and the 1.5-fold reduction of the ubiquitin-fusion degradation system-1, which in conjunction with unchanged proteasomal subunit levels and proteasomal activity results in massive storage of ubiquitin/protein complexes and in autophagic cell death. A 2-fold decrease of cathepsin D might be an additional factor responsible for the accumulation of ubiquitin/protein conjugates. It is concluded that in human failing hearts apoptosis, oncosis, and autophagy act in parallel to varying degrees. A disturbed balance between a high rate of ubiquitination and inadequate degradation of ubiquitin/protein conjugates may contribute to autophagic cell death. Together, these different types of cell death play a significant role for myocyte disappearance and the development of contractile dysfunction in failing hearts.
Duplicate FLORICAULA/LEAFY homologs zfl1 and zfl2 control inflorescence architecture and flower patterning in maize
Authors: Bomblies Kirsten , Wang Rong-Lin , Ambrose Barbara A. , Schmidt Robert J. , Meeley Robert B. , Doebley John
Published: April 2003

The homologous transcription factors FLORICAULA of Antirrhinum and LEAFY of Arabidopsis share conserved roles in flower meristem identity and floral patterning. While roles for FLORICAULA/LEAFYhomologs in flower development have been demonstrated in numerous dicots,little is known about the function of these meristem identity genes in the more distantly related flowering plants, the monocots. We used reverse genetics to investigate the role of two duplicate FLORICAULA/LEAFYhomologs in maize (Zea mays L. ssp. mays) – a monocot species with dramatically different flower and inflorescence morphology from that of dicot species. Transposon insertions into the maize genes, zfl1 and zfl2, led to a disruption of floral organ identity and patterning, as well as to defects in inflorescence architecture and in the vegetative to reproductive phase transition. Our results demonstrate that these genes share conserved roles with their dicot counterparts in flower and inflorescence patterning. The phenotype of zfl1; zfl2 double mutants suggests that these maize FLORICAULA/LEAFY homologs act as upstream regulators of the ABC floral organ identity genes, and this along with previously published work, indicates that the transcriptional network regulating flower development is at least partially conserved between monocots and dicots. Our data also suggest that the zfl genes may play a novel role in controlling quantitative aspects of inflorescence phyllotaxy in maize,consistent with their candidacy for quantitative trait loci that control differences in inflorescence structure between maize and its progenitor,teosinte.
The regional pattern of retinoic acid synthesis by RALDH2 is essential for the development of posterior pharyngeal arches and the enteric nervous system
Authors: Niederreither Karen , Vermot Julien , Roux Isabelle Le , Schuhbaur Brigitte , Chambon Pierre , Dollé Pascal
Published: April 2003

Targeted inactivation of the mouse retinaldehyde dehydrogenase 2(RALDH2/ALDH1a2), the enzyme responsible for early embryonic retinoic acid synthesis, is embryonic lethal because of defects in early heart morphogenesis. Transient maternal RA supplementation from E7.5 to (at least)E8.5 rescues most of these defects, but the supplemented Raldh2–/– mutants die prenatally, from a lack of septation of the heart outflow tract (Niederreither, K., Vermot, J.,Messaddeq, N., Schuhbaur, B., Chambon, P. and Dollé, P.(2001). Development 128, 1019-1031). We have investigated the developmental basis for this defect, and found that the RA-supplemented Raldh2–/– embryos exhibit impaired development of their posterior (3rd-6th) branchial arch region. While the development of the first and second arches and their derivatives, as well as the formation of the first branchial pouch, appear to proceed normally, more posterior pharyngeal pouches fail to form and the pharyngeal endoderm develops a rudimentary, pouch-like structure. All derivatives of the posterior branchial arches are affected. These include the aortic arches, pouch-derived organs(thymus, parathyroid gland) and post-otic neural crest cells, which fail to establish segmental migratory pathways and are misrouted caudally. Patterning and axonal outgrowth of the posterior (9th-12th) cranial nerves is also altered. Vagal crest deficiency in Raldh2–/–mutants leads to agenesis of the enteric ganglia, a condition reminiscent of human Hirschprung's disease. In addition, we provide evidence that: (i)wildtype Raldh2 expression is restricted to the posteriormost pharyngeal mesoderm; (ii) endogenous RA response occurs in both the pharyngeal endoderm and mesoderm, and extends more rostrally than Raldh2expression up to the 2nd arch; (iii) RA target genes (Hoxa1, Hoxb1)are downregulated in both the pharyngeal endoderm and mesoderm of mutant embryos. Thus, RALDH2 plays a crucial role in producing RA required for pharyngeal development, and RA is one of the diffusible mesodermal signals that pattern the pharyngeal endoderm.
Pitx3 is required for motor activity and for survival of a subset of midbrain dopaminergic neurons
Authors: van den Munckhof Pepijn , Luk Kelvin C. , Ste-Marie Line , Montgomery Jane , Blanchet Pierre J. , Sadikot Abbas F. , Drouin Jacques
Published: April 2003

Mesencephalic dopaminergic (MesDA) neurons play crucial roles in motor and behavioral processes; their loss in Parkinson's disease (PD) results in striatal dopamine (DA) deficiency and hypokinetic movement disorder. The Pitx3 homeobox gene is expressed in the MesDA system. We now show that only a subset of MesDA neurons express Pitx3 and that in Pitx3-deficient aphakia mice, this subset is progressively lost by apoptosis during fetal (substantia nigra, SN) and postnatal (ventral tegmental area) development, resulting in very low striatal DA and akinesia. Similar to human PD, dorsal SN neurons (which are Pitx3 negative) are spared in mutant mice. Thus, Pitx3 defines a pathway for survival of neurons that are implicated in PD and that are required for spontaneous locomotor activity.
Drosophilahomeodomain protein REPO controls glial differentiation by cooperating with ETS and BTB transcription factors
Authors: Yuasa Yoshihiro , Okabe Masataka , Yoshikawa Shingo , Tabuchi Katsuhiko , Xiong Wen-Cheng , Hiromi Yasushi , Okano Hideyuki
Published: April 2003

In Drosophila, cell-fate determination of all neuroectoderm-derived glial cells depends on the transcription factor Glial cells missing (GCM), which serves as a binary switch between the neuronal and glial cell fates. Because the expression of GCM is restricted to the early phase of glial development, other factors must be responsible for the terminal differentiation of glial cells. Expression of three transcription factors,Reversed Polarity (REPO), Tramtrack p69 (TTK69) and PointedP1 (PNTP1), is induced by GCM in glial cells. REPO is a paired-like homeodomain protein,expressed exclusively in glial cells, and is required for the migration and differentiation of embryonic glial cells. To understand how REPO functions in glial terminal differentiation, we have analyzed the mechanism of gene regulation by REPO. We show that REPO can act as a transcriptional activator through the CAATTA motif in glial cells, and define three genes whose expression in vivo depends on REPO function. In different types of glial cells, REPO can act alone, or cooperate with either TTK69 or PNTP1 to regulate different target genes. Coordination of target gene expression by these three transcription factors may contribute to the diversity of glial cell types. In addition to promoting glial differentiation, we found that REPO is also necessary to suppress neuronal development, cooperating with TTK69. We propose that REPO plays a key role in both glial development and diversification.
Reaction Stereochemistry of 2-Deoxy-scyllo-inosose Synthase, the Key Enzyme in the Biosynthesis of 2-Deoxystreptamine
Authors: Nango Eriko , Kudo Fumitaka , Eguchi Tadashi , Kakinuma Katsumi
Published: April 2003

The reaction stereochemistry of 2-deoxy-scyllo-inosose (DOI) synthase (DOIS) derived from butirosin-producing Bacillus circulans, the key starter enzyme of 2-deoxystreptamine biosynthesis, was closely analyzed by use of the purified recombinant DOIS. The stereochemical pathway of the DOIS reaction is common in the aminoglycoside-producing Bacillus and Streptomyces, but is distinct from a related dehydroquinate synthase reaction in the shikimate pathway. Evolutionary relationship between these enzymes is also discussed.
Long-range RNA–RNA interaction between the 5′ nontranslated region and the core-coding sequences of hepatitis C virus modulates the IRES-dependent translation
Authors: KIM YOON KI , LEE SONG HEE , KIM CHON SAENG , SEOL SU KYOUNG , JANG SUNG KEY
Published: April 2003

Hepatitis C virus (HCV) is a positive-sense RNA virus ∼9600 bases long. An internal ribosomal entry site (IRES) spans the 5′ nontranslated region, which is the most conserved and highly structured region of the HCV genome. In this study, we demonstrate that nucleotides 428–442 of the HCV core-coding sequence anneal to nucleotides 24–38 of the 5′NTR, and that this RNA–RNA interaction modulates IRES-dependent translation in rabbit reticulocyte lysate and in HepG2 cells. The inclusion of the core-coding sequence (nucleotides 428–442) significantly suppressed the translational efficiency directed by HCV IRES in dicistronic reporter systems, and this suppression was relieved by site-directed mutations that blocked the long-range interaction between nucleotides 24–38 and 428–442. These findings suggest that the long-range interaction between the HCV 5′NTR and the core-coding nucleotide sequence down-regulate cap-independent translation via HCV IRES. The modulation of protein synthesis by long-range RNA–RNA interaction may play a role in the regulation of viral gene expression.
Stable RNA structures can repress RNA synthesis in vitro by the brome mosaic virus replicase
Authors: ZHANG XIN , KIM CHUL-HYUN , SIVAKUMARAN K. , KAO CHENG
Published: April 2003

A 15-nucleotide (nt) unstructured RNA with an initiation site but lacking a promoter could direct the initiation of RNA synthesis by the brome mosaic virus (BMV) replicase in vitro. However, BMV RNA with a functional initiation site but a mutated promoter could not initiate RNA synthesis either in vitro or in vivo. To explain these two observations, we hypothesize that RNA structures that cannot function as promoters could prevent RNA synthesis by the BMV RNA replicase. We documented that four different nonpromoter stem-loops can inhibit RNA synthesis from an initiation-competent RNA sequence in vitro. Destabilizing these structures increased RNA synthesis. However, RNA synthesis was restored in full only when a BMV RNA promoter element was added in cis. Competition assays to examine replicase–RNA interactions showed that the structured RNAs have a lower affinity for the replicase than do RNAs lacking stable structures or containing a promoter element. The results characterize another potential mechanism whereby the BMV replicase can specifically recognize BMV RNAs.
Structure of the U6 RNA intramolecular stem–loop harboring an SP-phosphorothioate modification
Authors: REITER NICHOLAS J. , NIKSTAD LAURA J. , ALLMANN ANNE M. , JOHNSON RANDAL J. , BUTCHER SAMUEL E.
Published: April 2003

Phosphorothioate-substitution experiments are often used to elucidate functionally important metal ion-binding sites on RNA. All previous experiments with SP-phosphorothioate-substituted RNAs have been done in the absence of structural information for this particular diastereomer. Yeast U6 RNA contains a metal ion-binding site that is essential for spliceosome function and includes the pro-SP oxygen 5′ of U80. SP-phosphorothioate substitution at this location creates spliceosomes dependent on thiophilic ions for the first step of splicing. We have determined the solution structure of the U80SP-phosphorothioate-substituted U6 intramolecular stem–loop (ISL), and also report the refined NMR structure of the unmodified U6 ISL. Both structures were determined with inclusion of 1H–13C residual dipolar couplings. The precision of the structures with and without phosphorothioate (RMSD = 1.05 and 0.79 Å, respectively) allows comparison of the local and long-range structural effect of the modification. We find that the U6-ISL structure is unperturbed by the phosphorothioate. Additionally, the thermodynamic stability of the U6 ISL is dependent on the protonation state of the A79–C67 wobble pair and is not affected by the adjacent phosphorothioate. These results indicate that a single SP-phosphorothioate substitution can be structurally benign, and further validate the metal ion rescue experiments used to identify the essential metal-binding site(s) in the spliceosome.
Analysis of the stimulatory effect of splicing on mRNA production and utilization in mammalian cells
Authors: LU SHIHUA , CULLEN BRYAN R.
Published: April 2003

We have examined how splicing affects the expression of a range of human and nonhuman genes in vertebrate cells. Although our data demonstrate that splicing invariably enhances the level of gene expression, this positive effect is generally moderate. However, in the case of the human β-globin gene, splicing is essential for significant protein expression. In the absence of introns, 3′ end processing is inefficient, and this appears to be causally linked to a significant decrease in the level of both nuclear and cytoplasmic 3′ end-processed RNA. In contrast, splicing appears to only modestly enhance nuclear mRNA export. Consistent with this observation, intronless β-globin gene expression was only partially rescued by the insertion of retroviral nuclear mRNA export elements. Surprisingly, in the case of the highly intron dependent β-globin gene, the mRNA that did reach the cytoplasm was also only inefficiently translated if it derived from an intronless expression plasmid. Together, these data argue that splicing can increase gene expression by enhancing mRNA 3′ end processing, and hence, mRNA production. Moreover, in the case of the highly intron-dependent β-globin gene, splicing also significantly enhanced the translational utilization of cytoplasmic β-globin mRNAs.
Prevalence of birth defects among infants of Gulf War veterans in Arkansas, Arizona, California, Georgia, Hawaii, and Iowa, 1989–1993
Authors: G. Araneta Maria Rosario , Schlangen Karen M. , Edmonds Larry D. , Destiche Daniel A. , Merz Ruth D. , Hobbs Charlotte A. , Flood Timothy J. , Harris John A. , Krishnamurti Diane , Gray Gregory C.
Published: April 2003

BACKGROUND

Epidemiologic studies of birth defects among infants of Gulf War veterans (GWV) have been limited to military hospitals, anomalies diagnosed among newborns, or self‐reported data. This study was conducted to measure the prevalence of birth defects among infants of GWVs and nondeployed veterans (NDV) in states that conducted active case ascertainment of birth defects between 1989–93.

METHODS

Military records of 684,645 GWVs and 1,587,102 NDVs were electronically linked with 2,314,908 birth certificates from Arizona, Hawaii, Iowa, and selected counties of Arkansas, California, and Georgia; 11,961 GWV infants and 33,052 NDV infants were identified. Of these, 450 infants had mothers who served in the Gulf War, and 3966 had NDV mothers.

RESULTS

Infants conceived postwar to male GWVs had significantly higher prevalence of tricuspid valve insufficiency (relative risk [RR], 2.7; 95% confidence interval [CI], 1.1–6.6; p = 0.039) and aortic valve stenosis (RR, 6.0; 95% CI, 1.2–31.0; p = 0.026) compared to infants conceived postwar to NDV males. Among infants of male GWVs, aortic valve stenosis (RR, 16.3; 95% CI, 0.09–294; p = 0.011) and renal agenesis or hypoplasia (RR, 16.3; 95% CI, 0.09–294; p = 0.011) were significantly higher among infants conceived postwar than prewar. Hypospadias was significantly higher among infant sons conceived postwar to GWV women compared to NDV women (RR, 6.3; 95% CI, 1.5–26.3; p = 0.015).

CONCLUSION

We observed a higher prevalence of tricuspid valve insufficiency, aortic valve stenosis, and renal agenesis or hypoplasia among infants conceived postwar to GWV men, and a higher prevalence of hypospadias among infants conceived postwar to female GWVs. We did not have the ability to determine if the excess was caused by inherited or environmental factors, or was due to chance because of myriad reasons, including multiple comparisons. Although the statistical power was sufficient to compare the combined birth defects prevalence, larger sample sizes were needed for less frequent individual component defects. Birth Defects Research (Part A) 67:246–260, 2003. Published 2003 Wiley‐Liss, Inc.
Zinc treatment prevents lipopolysaccharide‐induced teratogenicity in mice
Authors: Carey Luke C. , Berbée Paulien L. , Coyle Peter , Philcox Jeffrey C. , Rofe Allan M.
Published: April 2003

Background

During pregnancy, exposure to lipopolysaccharide (LPS) can lead to abortion, preterm delivery, and teratogenicity. The mechanisms underlying these effects are unclear. Both LPS and ethanol are potent inducers of liver metallothionein (MT), a key Zn binding protein. The teratogenic effects of ethanol have been linked to MT‐induced changes in maternal‐fetal Zn homeostasis, leading to fetal deficiency. This study was designed to assess whether the teratogenic effects of LPS are also related to MT induction and changes in Zn homeostasis.

METHODS

Non‐pregnant normal (MT+/+) and MT‐null (MT−/−) mice were injected subcutaneously with 0.5 μg/gm LPS and killed over 48 hr. In MT+/+ mice, liver MT concentrations were elevated from 6 hr, and were maximal at 24 hr (30‐fold basal), whereas liver Zn levels were also increased from 6 hr. Plasma Zn concentrations decreased by 80% at 6 hr, and were below normal between 6 and 24 hr. In MT−/− mice, plasma Zn levels were increased from basal between 6 and 16 hr. Dams were injected with LPS, saline, or LPS and ZnSO4 (2 μg/gm, MT+/+ only) on Day 8 of gestation (GD8), killed on GD18, and the fetuses examined for malformations.

RESULTS

External abnormalities were most prevalent in fetuses from MT+/+ dams exposed to LPS, where 34% of fetuses in each litter were affected. MT+/+ dams treated with LPS and ZnSO4, and MT−/− dams treated with LPS had litters in which 5.4 and 4.8% of fetuses were abnormal respectively.

CONCLUSIONS

The findings of this study strongly support the hypothesis that LPS teratogenicity is mediated at least in part by MT‐induced changes in maternal Zn homeostasis, which compromises fetal Zn supply. Birth Defects Research (Part A) 67:240–245, 2003. © 2003 Wiley‐Liss, Inc.
Population‐based study of congenital diaphragmatic hernia: Risk factors and survival in metropolitan Atlanta, 1968–1999
Authors: Dott Mary M. , Wong Lee‐Yang C. , Rasmussen Sonja A.
Published: April 2003

BACKGROUND

Congenital diaphragmatic hernia affects about 1000 United States infants a year. In most cases, the etiology of this condition is unknown. Treatment strategies have changed in recent years. We sought to calculate the birth prevalence, determine risk factors, examine associated defects, and assess trends in survival.

METHODS

We conducted a population‐based cohort study of all infants born during 1968–99 whose mothers resided in the five‐county metropolitan Atlanta area (n = 1,029,143). Infants with congenital diaphragmatic hernia were identified using the Metropolitan Atlanta Congenital Defects Program. To document vital status, we used data from hospital records, Georgia vital records, and the National Death Index.

RESULTS

The birth prevalence of congenital diaphragmatic hernia was 2.4 per 10,000 births. Infants with isolated congenital diaphragmatic hernia were more likely to be premature, macrosomic, and male than their birth cohort. About one‐third of affected infants had additional major defects. Of infants with congenital diaphragmatic hernia, 8% had known syndromes, most commonly chromosomal abnormalities. During the study period, the percentage of infants with congenital diaphragmatic hernia who survived to 1 year of age increased from 19% (1968–71) to about 54% (1996–99). During the last 10 years of the study, infants who were of low birth weight, had a syndrome, or were prenatally diagnosed were more likely to die than other infants with congenital diaphragmatic hernia.

CONCLUSIONS

Despite new treatments, the death rate from congenital diaphragmatic hernia remains substantial, highlighting the need to identify mechanisms for primary prevention. Birth Defects Research (Part A) 67:261–267, 2003. Published 2003 Wiley‐Liss, Inc.
Asymmetry in first‐price auctions with affiliated private values
Authors: Campo Sandra , Perrigne Isabelle , Vuong Quang
Published: April 2003

Collusion and heterogeneity across firms may introduce asymmetry in bidding games. A major difficulty in asymmetric auctions is that the Bayesian Nash equilibrium strategies are solutions of an intractable system of differential equations. We propose a simple method for estimating asymmetric first‐price auctions with affiliated private values. Considering two types of bidders, we show that these differential equations can be rewritten using the observed bid distribution. We establish the identification of the model, characterize its theoretical restrictions, and propose a two‐step non‐parametric estimation procedure for estimating the private value distributions. An empirical analysis of joint bidding in OCS auctions is provided. Copyright © 2003 John Wiley & Sons, Ltd.
Why “auditing” is a dirty word
Authors: Noland Thomas G.
Published: April 2003

Because of recent corporate scandals, “auditing” is held in low esteem by the public. However,
auditing has also become a “dirty word” for large accounting firms—who are offering profitable
new services at the expense of quality audits. But are there other reasons audit quality has plummeted?
© 2003 Wiley Periodicals, Inc.