bluuebunny/crossref_metadata_2025 huggingface dataset:
Perinatal changes in expression of aquaporin‐4 and other water and ion transporters in rat lung
Authors: Yasui Masato , Serlachius Eva , Löfgren Malin , Belusa Roger , Nielsen Søren , Aperia Anita
Published: September 2004

At birth, rapid removal of lung liquid from potential airspaces is required to establish pulmonary gas exchange. To investigate the role for water channels, aquaporins (AQP) and ion transporters in this process, the mRNA expression of AQP, Na+,K+‐ATPase and the amiloride‐sensitive Na+ channel (ENaC) were studied in the fetal and postnatal rat lung.

The mRNA expression of all transporters studied increased postnatally.

The following water channels were expressed in the lung, AQP1, 4 and 5. The most specific perinatal induction pattern was observed for AQP4. A sharp and transient increase of AQP4 mRNA occurred just after birth coinciding with the time course for clearance of lung liquid. This transient induction of AQP4 mRNA at birth was lung‐tissue specific. Around birth there was a moderate increase in AQP1 mRNA, which was not transient. AQP5 increased continuously until adulthood.

Fetal lung AQP4 mRNA was induced by both β‐adrenergic agonists and glucocorticoid hormone, which are factors that have been suggested to accelerate the clearance of lung liquid.

Immunocytochemistry revealed that AQP4 was located in the basolateral membranes of bronchial epithelia in newborn rats, consistent with the view that this is the major site for perinatal lung liquid absorption.

The Na+, K+‐ATPase α1 subunit and ENaC α‐subunit mRNA also increased around birth, suggesting that they co‐operatively facilitate lung liquid clearance at birth.

These data indicate that removal of lung liquid at birth is associated with pronounced and well‐synchronized changes in the expression of AQP and the ion transporters studied. The transient perinatal induction of AQP4, which could be prenatally induced by β‐adrenergic agonists, and the localization of this water channel strongly suggest that it plays a critical role for removal of lung liquid at the time of birth.
Currents evoked in Bergmann glial cells by parallel fibre stimulation in rat cerebellar slices
Authors: Clark Beverley A. , Barbour Boris
Published: September 2004

Whole‐cell recordings were obtained from Bergmann glial cells in rat cerebellar slices.

The cells had low input resistances (70 ± 38 mV; n= 13) and a mean resting potential of −82 ± 6 mV (n= 12) with a potassium‐based internal solution. Electrical and dye coupling between Bergmann glia were confirmed.

Stimulation of parallel fibres induced a complex, mostly inward current which could be decomposed pharmacologically.

The ionotropic glutamate receptor antagonist, 6‐cyano‐7‐nitroqumoxalme‐2,3‐dione (CNQX; 10 μM), but not DL‐2‐amino‐5‐phosphonopentanoic acid (DL‐APV; 100μM) consistently blocked an early inward current component that may reflect synaptic activation of AMPA/kainate receptors in Bergmann glia.

Addition of cadmium ions (100 μM) to inhibit transmitter release blocked most of the CNQX‐APV‐insensitive current. This component probably reflects electrogenic uptake of the synaptically released glutamate.

Tetrodotoxin (TTX; 1 μM) blocked the remaining inward current: a slow component, possibly produced by the potassium ion efflux during action potential propagation in parallel fibres. An initial triphasic component of the response was also TTX sensitive and reflected passage of the parallel fibre action potential volley.

The putative glutamate uptake current was further characterized; it was blocked by the competitive uptake blockers D‐aspartate (0.5 mM) and L‐trans‐pyrrolidine‐2,4‐dicarboxylic acid (PDC; 0.5 mM), and by replacement of sodium with lithium. Monitoring the triphasic TTX‐sensitive component showed that this inhibition did not result from changes of action potential excitation and propagation.

Intracellular nitrate ions increased the putative uptake current, consistent with the effect of this anion on glutamate transporters.

The putative uptake current was reduced by depolarization, consistent with the voltage dependence of glutamate uptake.

It is concluded that a large fraction of the current induced by parallel fibre stimulation reflects the uptake of synaptically released glutamate. The uptake current activated rapidly, with a 20–80% rise time of 2.3 ± 0.7 ms (n= 10), and decayed with a principal time constant of 25 ± 6 ms (n= 10).
Electrically induced vasomotor responses and their propagation in rat renal vessels In vivo
Authors: Steinhausen Michael , Endlich Karlhans , Nobiling Rainer , Parekh Niranjan , Schütt Florian
Published: September 2004

Vasomotor responses (VMR) induced by local electrical stimulation were studied in the vasculature of the split hydronephrotic rat kidney by in vivo microscopy.

Unipolar pulses, which were applied by a micropipette positioned close to the vessel wall, elicited local and propagated VMR. Depolarizing and hyperpolarizing currents caused vaso‐constriction and vasodilatation, respectively.

The magnitude of VMR could be controlled within seconds by variation of pulse frequency, pulse width and voltage. VMR were abolished by slight retraction of the stimulating micro‐pipette. Repetitive electrical stimulation resulted in reproducibly uniform VMR.

Propagated VMR decayed with increasing distance from the stimulation site. They decayed more rapidly in the upstream than in the downstream flow direction in interlobular arteries. The longitudinal decay was well approximated by an exponential function with significantly different length constants of 150 ± 40 μm (upstream, n= 5) and 420 ± 90 μm (downstream, n=8).

Our results show that vasomotor responses, which are initiated by changes in membrane potential, are propagated over distances of potential physiological importance in interlobular arteries.
TEM evidence for eukaryotic diversity in mid‐Proterozoic oceans
Authors: JAVAUX EMMANUELLE J. , KNOLL ANDREW H. , WALTER MALCOLM R.
Published: September 2004

Biomarker molecular fossils in 2770 Ma shales suggest that the Eucarya diverged from other principal domains early in Earth history. Nonetheless, at present, the oldest fossils that can be assigned to an extant eukaryotic clade are filamentous red algae preserved in ca. 1200 Ma cherts from Arctic Canada. Between these records lies a rich assortment of potentially protistan microfossils. Combined light microscopy, scanning electron microscopy, and transmission electron microscopy on 1500‐1400 Ma fossils from the Roper Group, Australia, and broadly coeval rocks from China show that these intermediate assemblages do indeed include a moderate diversity of eukaryotic remains. In particular, preserved cell wall ultrastructure, observed using transmission electron microscopy (TEM), can help to bridge the current stratigraphic gap between the unambiguous eukaryotic morphologies of later Proterozoic assemblages and molecular biomarkers in much older rocks.
Archaeal phylotypes in a metal‐rich and low‐activity deep subsurface sediment of the Peru Basin, ODP Leg 201, Site 1231
Authors: SØRENSEN K. B. , LAUER A. , TESKE A.
Published: September 2004

Site 1231 of the Ocean Drilling Project (ODP) was characterized by low concentrations of organic carbon, as well as low cell numbers and biological activity rates. A 16S rRNA survey was performed in order to analyse the microbial community composition of these central oceanic sediments. Archaeal 16S rRNA genes from subsurface sediments at Site 1231 (1.8, 9.0, and 43 mbsf) were affiliated with uncultured lineages from subsurface or hydrothermal vent habitats. Members of the Marine Group I (MGI) found in the 1.8 mbsf sediment formed distinct clusters, some dominated by phylotypes from Site 1231 and other subsurface environments. The archaeal community survey at Site 1231 indicated that several archaeal lineages were widespread in subsurface environments, marine sediments as well as hydrothermal habitats.
Hydrogen isotope fractionation during H2/CO2 acetogenesis: hydrogen utilization efficiency and the origin of lipid‐bound hydrogen
Authors: VALENTINE D. L. , SESSIONS A. L. , TYLER S. C. , CHIDTHAISONG A.
Published: September 2004

Hydrogen metabolism was studied in the anaerobic bacterium, Sporomusa sp. strain DMG 58, by measuring natural abundance levels of deuterium in H2, H2O, and individual fatty acids during acetogenic growth on H2/CO2. Four cultures were grown, each in medium with a distinct hydrogen‐isotopic composition (δD‐H2O). The δD value of H2 was quantified in the residual gas exiting the growth chambers and found to decrease concurrently with net H2 consumption, indicating rapid isotope exchange between H2 and H2O. An isotopic mass balance was used to constrain the efficiency with which H2 was activated by the cell and the reducing equivalents catabolized, which we term the H2 utilization efficiency. Results indicate that H2 utilization efficiency in these cultures is less than 20% during the growth phase, and less than 2% after the growth phase. The gross rate of cellular H2 activation was similar in the growth phase and afterward. Biomass harvested at the end of each experiment was used to analyse the D/H of individual membrane lipids. Values of δD were highly correlated between lipids and water (δD‐lipids = 0.59 × δD‐water – 381‰; R2 = 0.995), indicating the source of lipid hydrogen is in isotopic equilibrium with water. Results are consistent with two possibilities: (i) water is the sole source of hydrogen to lipids, and the fractionation during biosynthesis is significantly larger than previously observed (α = 0.59), or (ii) hydrogen from H2 is incorporated into lipids, but only after reaching isotopic equilibrium with H2O. Fatty acids were strongly depleted in deuterium relative to all other organisms studied thus far, and such large depletions may prove useful as biomarkers for studying H2 cycling in anoxic environments as well as in the geological record.
Fructose overload modifies vascular morphology and prostaglandin production in rats
Authors: Puyó A. M. , Mayer M. A. , Cavallero S. , Donoso A. S. , Peredo H. A.
Published: September 2004

1 A fructose (Fru)‐enriched diet induces a mild increase in blood pressure associated with hyperglycaemia, hypertriglyceridaemia, and insulin resistance, resembling the human ‘syndrome X’, being an useful model to study hypertension and type 2 diabetes.

2 A sustained elevation of blood pressure is associated with cardiovascular structural modifications such as left ventricular hypertrophy and increased wall thickness:lumen diameter ratio in blood vessels.

3 Prostanoids (PR), metabolites of arachidonic acid through the cyclooxygenase pathway, include vasoactive substances synthesized and released by the vessel walls.

4 The aim of the present study was to analyse, in Fru‐treated rats: (i) the morphology of mesenteric vessels and; (ii) the PR production in aorta and mesenteric vessels, in order to assess whether these parameters are related with the haemodynamic alterations observed in this experimental model.

5 Blood pressure, glycaemia and triglyceridaemia, were significantly elevated in both (4 and 22 weeks) Fru‐treated groups. Meanwhile body and heart weight as well as insulinaemia were similar between experimental animals and controls.

6 The mesenteric vessels of Fru‐treated rats (22 weeks) showed an increased thickness and area of the media when compared with the controls; meanwhile, the lumen diameter was similar in both groups.

7 The Fru treatment for 4 weeks did not modify PR production in aorta, whereas in the mesenteric bed it diminished prostaglandin (PG) E2 release significantly compared with the controls. However, in the group treated for 22 weeks, Fru reduced PGI2 production in the aorta, as assessed by 6‐keto‐PGF1α measurements. Meanwhile, in the mesenteric bed, the chronic Fru treatment decreased PGE2 release but, rather surprisingly, increased the output of PGI2 when compared with its corresponding controls.

8 In conclusion, the present study shows the existence of an alteration in the morphology of mesenteric vessels in Fru‐treated rats, which could be related to an increase in peripheral resistance and the consequent mild hypertension observed in this model. However, a diminished release of vasodilator PRs, such as PGE2 in mesenteric vessels at 4 and 22 weeks and PGI2 in aorta at 22 weeks could further impair the vessel response. The increase in PGI2 observed in the chronic group in mesenteric vessels could be attributed to a compensatory mechanism.
Identifying women at‐risk for postpartum depression in the immediate postpartum period
Authors: Dennis C.‐L. E. , Janssen P. A. , Singer J.
Published: September 2004

Objective:  To develop a multifactorial predictive model of depressive symptomatology in the first week postpartum in order to assist in targeted screening procedures.

Method:  As part of a longitudinal study, a population‐based sample of 594 mothers in a health region near Vancouver, British Columbia completed a mailed questionnaire at 1‐week postpartum that included diverse risk factors from the following domains: sociodemographic, biological, pregnancy‐related, life stressors, social support, obstetric and adjustment to motherhood. Following univariate analysis, sequential regression analysis was completed to develop a multifactorial predictive model.

Results:  In the multivariate model, the factors predictive of depressive symptomatology at 1‐week postpartum included immigration within the last 5 years, history of depression independent of childbirth, diagnosis of pregnancy‐induced hypertension, vulnerable personality style, stressful life events, lack of perceived support, lack of readiness for hospital discharge and dissatisfaction with infant feeding method.

Conclusion:  The findings suggest that several risk factors for depressive symptomatology in the immediate postpartum period are consistent with previously identified factors but other factors such as recent immigrant status, feeling unready for hospital discharge, dissatisfaction with their infant feeding method, and pregnancy‐induced hypertension should also be examined.
Prevalence of bipolar disorder in the general population: a Reappraisal Study of the Netherlands Mental Health Survey and Incidence Study
Authors: Regeer E. J. , Ten Have M. , Rosso M. L. , Hakkaart‐van Roijen L. , Vollebergh W. , Nolen W. A.
Published: September 2004

Objective:  The Netherlands Mental Health Survey and Incidence Study (NEMESIS) is a Dutch population study using a fully structured interview (Composite International Diagnostic Interview, CIDI), administered by trained interviewers. Based on all three assessments of NEMESIS, 2.4% of the respondents were identified with lifetime bipolar disorder (DSM‐III‐R).

The primary aim of the study was to estimate the prevalence of bipolar disorder in the same population based on a semistructured interview administered by clinicians.

Method:  Seventy‐four persons identified with a lifetime CIDI/DSM‐III‐R bipolar disorder and 40 persons with a major depressive disorder (MDD) were reinterviewed with the Structured Clinical Interview for DSM (SCID).

Results:  Based on the SCID, 30 of 74 respondents with a CIDI/DSM‐III‐R bipolar disorder and eight of 40 respondents with MDD met DSM‐IV criteria for bipolar disorder or cyclothymia, corresponding with an adjusted lifetime prevalence in these groups of 1% (95% CI: 0.7–1.3%) and 4.2% (95% CI: 1.6–6.9%) respectively.

Conclusion:  Compared with the SCID, the CIDI on the one hand overdiagnoses bipolar disorder but on the other hand underdiagnoses bipolar disorder.
Early detection of relapse in panic disorder
Authors: Mavissakalian M. R. , Guo S.
Published: September 2004

Objective:  To explore predictive models of relapsing based on change in symptoms at a time when panic disorder patients are still in remission following discontinuation of antidepressants.

Method:  Forty‐seven subjects, who were randomized to double‐blind placebo and who had valid data at four time points: pretreatment, randomization to placebo substitution, an assessment on placebo prior to the last assessment or relapse and their last assessment (relapsers n = 15, non‐relapsers n = 32) were studied using descriptive, growth curve analysis and logistic regression methodologies.

Results:  Measures of generalized anxiety, fearfulness and disability at work and at home were better predictors of relapse than measures of panic and anxiety sensitivity. Logistic regression models using any one of these four general variables and its linear change correctly predicted relapse for 78.7–84.4% of the study subjects.

Conclusion:  It is possible to gauge, with a fair degree of accuracy, the probability of relapsing in panic disorder patients who have discontinued serotonergic antidepressants 2 months prior to the return of panic.
Predictors of parenting outcome in women with psychotic disorders discharged from mother and baby units
Authors: Howard L. M. , Thornicroft G. , Salmon M. , Appleby L.
Published: September 2004

Objective:  To compare the social and clinical characteristics of mothers with psychotic disorders with parenting difficulties, with mothers with no significant parenting problems.

Method:  Descriptive and case–control study.

Results:  Over half of the women with psychotic disorders admitted to psychiatric mother and baby units had a good outcome at the time of discharge – 70% did not need social services supervision, and had no significant parenting problem as judged by clinical staff. Diagnosis was independently associated with all measures of poor parenting; compared with a diagnosis of psychotic depression, a diagnosis of schizophrenia was highly significantly associated with social services supervision [adjusted odds ratio (OR) 25.7; 95% CI 5.97, 111.05], and staff rated problems with emotional responsiveness (adjusted OR 3.39;95% CI 1.42, 8.08), practical baby care (adjusted OR 6.07; 95% CI 2.12, 17.39), and perceived risk of harm to baby (adjusted OR 7.81; 95% CI. 2, 30.53). Low social class and psychiatric illness in the partner were also significantly associated with poor parenting outcomes, including social services supervision (adjusted OR 3.88; 95% CI 2.07, 7.25 and 4.23; 95% CI 2.1, 8.55, respectively).

Conclusions:  Although these associations do not demonstrate causality, these findings suggest preventative interventions targeting socio‐economic difficulties, early treatment of psychosis, and detection and treatment of psychiatric problems in the partner may be helpful in improving parenting outcomes in these vulnerable families.
Early maternal stress and health behaviours and offspring expression of psychosis in adolescence
Authors: Spauwen J. , Krabbendam L. , Lieb R. , Wittchen H. U. , van Os J.
Published: September 2004

Objective:  It has been suggested that influences operating early in life may affect the risk of postpubertal psychosis outcomes. This hypothesis was tested using a broad outcome of psychotic symptoms expressed in adolescence (prevalence: 15.6%).

Method:  Findings are based on a longitudinal, population‐based cohort study of 963 adolescents aged 15–20 years and their parents in the area of Munich, Germany. Trained psychologists assessed adolescents with the Munich‐Composite International Diagnostic Interview. Independently, direct diagnostic interviews were conducted with the parents.

Results:  A range of medical complications of pregnancy and delivery, including lower birth weight, were not associated with the psychosis outcome. However, a number of maternal health behaviours and experiences did show associations, independent of confounders.

Conclusion:  Not maternally reported medical complications of pregnancy and delivery, but maternal prenatal health behaviours predicted expression of psychosis along a continuum in adolescence. This effect may either be direct or constitute a proxy for later postnatal maternal behaviours associated with psychosis risk in the offspring.
Characterization of virus infectivity and cell‐free capsid assembly of SIVMneCL8
Authors: Dooher Julia E. , Pineda Mario Javier , Overbaugh Julie , Lingappa Jaisri R.
Published: September 2004

Abstract:  We have previously described a cell‐free system that reconstitutes immature capsid assembly of Gag polypeptides from viruses belonging to three major primate lentiviral lineages, including HIV‐1, HIV‐2 and SIVagm. Studies described here examine a member of the SIVmac/Mne lineage, SIVMneCL8, using assays for virus production and infectivity as well as cellular events in capsid formation. We report that SIVMneCL8, a molecular clone with properties typical of transmitted viral variants, is less infectious per unit p27 Gag than another member of the SIVmac/Mne lineage, SIVmac239. SIVMneCL8 Gag polypeptides are arrested at an early stage of capsid assembly in the cell‐free system. Additionally, SIVMneCL8 Gag polypeptides associate minimally with the host factor human HP68. This is the first report of a primate lentivirus that does not complete capsid assembly in the cell‐free system.
Cell‐free systems for capsid assembly of primate lentiviruses from three different lineages
Authors: Dooher Julia E. , Lingappa Jaisri R.
Published: September 2004

Abstract:  We recently demonstrated that capsids from three main primate lentiviral lineages appear to form via a pathway of assembly intermediates in primate cells. Retroviral capsid assembly intermediates were initially identified and characterized using a cell‐free system for assembly of immature HIV‐1 capsids. Because cell‐free capsid assembly systems are useful tools, we are interested in developing such systems for other primate lentiviruses besides HIV‐1. Here we extend previous cell‐free studies by showing that Gag proteins of HIV‐2, from a second primate lentiviral lineage, progress from early intermediates to late intermediates and completed capsids over time. Additionally, we demonstrate that Gag proteins of SIVagm, from a third primate lentiviral lineage, associate with the cellular factor HP68 and complete assembly in this system. Therefore, cell‐free systems reproduce assembly of Gag from three main primate lentiviral lineages, and can be used to compare mechanistic features of capsid assembly of genetically divergent primate lentiviruses.
AIDS as a zoonosis? Confusion over the origin of the virus and the origin of the epidemics
Authors: Marx Preston A. , Apetrei Cristian , Drucker Ernest
Published: September 2004

Abstract:  Based on findings demonstrating the simian ancestry of HIV, AIDS has been reported to be a zoonosis. However, this theory has never been proved and must seriously be questioned. Several arguments show that HIV‐AIDS is not a zoonosis. (i) If AIDS were a zoonosis, there must be evidence of AIDS being directly acquired from an animal species, as is rabies, a disease that is directly acquired from animals. (ii) Despite long‐term and frequent human exposure to SIV‐infected monkeys in Africa, only 11 cross‐species transmission events are known, and only four of these have resulted in significant human‐to‐human transmission, generating HIV‐1 groups M and O and HIV‐2 groups A and B. The closest relatives of SIVcpz (HIV‐1 group N) and of SIVsm (HIV‐2 groups C–H) are extremely rare, with only six HIV‐1 group N‐infected patients and only single individuals known to be infected by HIV‐2 groups C–H. SIV, while capable of cross‐species transmission, is thus poorly adapted for disease and epidemic spread. If AIDS were a zoonosis that is capable of significant human‐to‐human spread, there would be a plethora of founder subtypes and groups. (iii) Human exposure to SIV is thousands of years old, but AIDS emerged only in the 20th century. If AIDS were a zoonosis that spread into the human population, it would have spread to the West during slave trade. (iv) Experimental transmission of SIVs to different species of monkeys is often well controlled by the new host, showing that the virus and not the disease is transmitted. Therefore, we conclude that cross‐species transmission of SIV does not in itself constitute the basis for a zoonosis. Transmission per se is not the major requirement for the generation of the AIDS epidemic. All HIVs do derive from simian species, but AIDS does not qualify as a zoonosis and this explanation cannot in itself account for the origin of AIDS epidemic. It is important to distinguish AIDS from true zoonoses (e.g. rabies) because research is needed to understand the processes by which animal viruses cause sustained human‐to‐human transmission, epidemics and even pandemics. Much is known about emerging viruses, but almost nothing is known about emerging viral diseases.
Perinatal transmission of SHIV‐SF162P3 in Macaca nemestrina
Authors: Jayaraman Pushpa , Mohan Deepika , Polacino Patricia , Kuller LaRene , Sheikh Nadeem , Bielefeldt‐Ohmann Helle , Richardson Barbra , Anderson David , Hu Shiu‐Lok , Haigwood Nancy L.
Published: September 2004

Abstract:  We developed a SHIV/macaque model of transmission from infected dams to their infants. Ten pregnant dams were infected intravenously with 100 MID50 of macaque‐titered SHIV‐SF162P3 during the second trimester. Nine infants were born; the seven surviving beyond day of birth suckled for 6 months. Four of nine infants were infected (transmission rate = 44.4%), with one infection in utero, and three intrapartum and/or immediately post‐birth via suckling. Varying levels of binding and neutralizing antibodies were transplacentally transferred to infants. Passive antibodies were detected in plasma on the day of birth and persisted for 5 weeks. Infants infected at or after birth controlled acute and post‐acute viremia. Exposure to maternal SHIV‐SF162P3 during birth and suckling in the presence of autologous maternal neutralizing antibodies may have affected transmission or pathogenesis in the infants. This transmission model can allow investigation of key parameters involved in perinatal transmission of HIV.
A retrospective study of dental behavior management problems in children with attention and learning problems
Authors: Blomqvist My , Holmberg Kirsten , Fernell Elisabeth , Dahllöf Göran
Published: September 2004

Attention and learning problems in children are common. The aim of this study was to investigate whether children with attention and learning problems had more dental behavior management problems (BMP), more cancelled and missed appointments, and more traumatic dental injuries compared with a control group. All children born in 1991 attending mainstream schools (n = 555) in one Swedish municipality were screened for behavioral and learning problems. Conners' 10‐item questionnaire and a questionnaire focused on executive and learning problems were used. A total of 128 screen‐positive patients were index cases and 131 screen‐negative patients control cases. The dental records of these children were studied from 1 yr of age until the child reached 10 yr. Behavior management problems on at least one occasion were more common in the index group (54% vs. 37%). The percentage of appointments at which the children exhibited BMP was higher in the index group (13% vs. 7%). No differences were found for cancelled or missed appointments or dental traumatic injuries between the two groups. In conclusion, the results of this study show that children with attention and learning problems had significantly more dental behavior management problems compared with a control group.
Delivery of cytolethal distending toxin B induces cell cycle arrest and apoptosis in gingival squamous cell carcinoma in vitro
Authors: Yamamoto Kozo , Tominaga Kazuhiro , Sukedai Miho , Okinaga Toshinori , Iwanaga Kenjiro , Nishihara Tatsuji , Fukuda Jin‐ichi
Published: September 2004

The cytolethal distending toxin (Cdt) from Actinobacillus actinomycetemcomitans consists of three proteins, CdtA, CdtB, and CdtC, which are responsible for cell cycle arrest and apoptosis. In the present study, local delivery systems of recombinant CdtB and CdtB‐expressing plasmid were established using Ca9‐22, human gingival squamous cell carcinoma cell line. When CdtB was delivered to Ca9‐22 cells using a BioPORTER, a 32‐kDa protein was detected by Western blotting, and G2 cell cycle arrest and apoptosis occurred. In addition, the CdtB delivered upregulated the expression of phosphorylated p53 and the cyclin‐dependent kinase inhibitor p21CIP1/WAF1 in Ca9‐22 cells, suggesting that these intracellular molecules might contribute to the induction of G2 cell cycle arrest and apoptosis. When the CdtB‐expressing plasmid was transfected into Ca9‐22 cells by lipofection or electroporation, CdtB (32 kDa) was clearly detected. Further, TdT‐mediated dUTP nick end labeling positive cells were observed after transfection of the CdtB‐expressing plasmid. These findings indicated that delivery of the CdtB protein and transfection of the cdtB gene induced cell cycle arrest and apoptosis in Ca9‐22 cells in vitro, and we conclude that it may be possible to induce apoptosis in human gingival squamous cell carcinoma by electroporation of the cdtB gene.
Collinearity in linear regression is a serious problem in oral health research
Authors: Tu Yu‐Kang , Clerehugh Valerie , Gilthorpe Mark S.
Published: September 2004

The aim of this article is to encourage good practice in the statistical analysis of dental research data. Our objective is to highlight the statistical problems of collinearity and multicollinearity. These are among the most common statistical pitfalls in oral health research when exploring the relationship between clinical variables using multiple regression analysis. We hope that this article will show why these problems arise and how they can be avoided and overcome. Examples from the periodontal literature will be used to illustrate how collinearity and multicollinearity can seriously distort the model development process as a result of the phenomenon of mathematical coupling. Knowledge of these problems can help to eliminate misleading results and improve any subsequent interpretations. Regression analyses are useful tools in oral health research when their limitations are recognized. However, care is required in planning and it is worthwhile seeking statistical advice when formulating the study's research questions.
Relationship between bacterial infection and evaluation using a laser fluorescence device, DIAGNOdent
Authors: Iwami Yukiteru , Shimizu Ayako , Narimatsu Masahiro , Hayashi Mikako , Takeshige Fumio , Ebisu Shigeyuki
Published: September 2004

The aim of this in vitro study was to investigate the relationship between bacterial infections in carious dentin when detected by two different methods – polymerase chain reaction (PCR), and a laser fluorescence device, DIAGNOdent. Dentin was removed every 300 µm in the direction of the pulp chamber in 10 extracted molars with occlusal dentin caries and 3 extracted sound molars. Dentin surfaces were evaluated using DIAGNOdent, and dentinal tissue samples were removed by using a round bur before and after each removal. Bacterial DNA in the dentinal tissues was detected by PCR, using primers based on the nucleotide sequence of a conserved region of the 16S rDNA, and yielded a PCR product of 466 bp. The rates of bacterial detection increased as the DIAGNOdent values increased. In the 10 specimens, the lowest DIAGNOdent value at which bacteria were detected was 15.6; at DIAGNOdent values below 15.6, no bacteria were detected. The results of a receiver operating characteristic (ROC) curve for the DIAGNOdent values showed that the area under the ROC curve was 0.91. This study clarified the relationship between the DIAGNOdent values of dentin caries and the rates of bacterial detection.
Dentin adhesion and microleakage of a resin‐based calcium phosphate pulp capping and basing cement
Authors: Dickens Sabine H. , Kelly Sean R. , Flaim Glenn M. , Giuseppetti Anthony A.
Published: September 2004

An experimental resin‐based bioactive calcium phosphate cement, intended as a pulp capping and basing material, was evaluated for dentin shear bond strength and microleakage. The interfacial morphology was examined by scanning electron microscopy (SEM). For microleakage, dentin cavities without (Group A) or after (Group B) acid etching were restored with the calcium phosphate cement. A resin‐based calcium hydroxide (VLC Dycal; Group C) was used as control material according to the manufacturer's instructions. After water storage and thermocycling, the microleakage was scored using a AgNO3 staining procedure. For the shear bond strength, flat exposed dentin surfaces were treated as for the microleakage test. Metal irises pressed against the dentin surface were filled with the cements, which were photocured. Both tests were carried out after 1 wk. While acid etching did not result in significantly greater microleakage, it led to higher shear bond strength, and allowed, as shown by SEM, the formation of a hybrid layer and resin tags. Both groups treated with the calcium phosphate cement had significantly lower microleakage scores and higher mean shear bond strength values than the groups treated with the control material.
Expression of monocarboxylate transporters in rat ocular tissues
Authors: Chidlow Glyn , Wood John P. M. , Graham Mark , Osborne Neville N.
Published: September 2004

The aim of the present study was to determine the distribution of monocarboxylate transporter (MCT) subtypes 1-4 in the various structures of the rat eye by using a combination of conventional and real-time RT-PCR, immunoblotting, and immunohistochemistry. Retinal samples expressed mRNAs encoding all four MCTs. MCT1 immunoreactivity was observed in photoreceptor inner segments, Müller cells, retinal capillaries, and the two plexiform layers. MCT2 labeling was concentrated in the inner and outer plexiform layers. MCT4 immunolabeling was present only in the inner retina, particularly in putative Müller cells, and the plexiform layers. No MCT3 labeling could be observed. The retinal pigment epithelium (RPE)/choroid expressed high levels of MCT1 and MCT3 mRNAs but lower levels of MCT2 and MCT4 mRNAs. MCT1 was localized to the apical and MCT3 to the basal membrane of the RPE, whereas MCT2 staining was faint. Although MCT1-MCT4 mRNAs were all detectable in iris and ciliary body samples, only MCT1 and MCT2 proteins were expressed. These were present in the iris epithelium and the nonpigmented epithelium of the ciliary processes. MCT4 was localized to the smooth muscle lining of large vessels in the iris-ciliary body and choroid. In the cornea, MCT1 and MCT2 mRNAs and proteins were detectable in the epithelium and endothelium, whereas evidence was found for the presence of MCT4 and, to a lesser extent, MCT1 in the lens epithelium. The unique distribution of MCT subtypes in the eye is indicative of the pivotal role that these transporters play in the maintenance of ocular function.
Weight loss through ileal transposition is accompanied by increased ileal hormone secretion and synthesis in rats
Authors: Strader April D. , Vahl Torsten P. , Jandacek Ronald J. , Woods Stephen C. , D’Alessio David A. , Seeley Randy J.
Published: September 2004

Bariatric surgeries, such as gastric bypass, result in dramatic and sustained weight loss that is usually attributed to a combination of gastric volume restriction and intestinal malabsorption. However, studies parceling out the contribution of enhanced intestinal stimulation in the absence of these two mechanisms have received little attention. Previous studies have demonstrated that patients who received intestinal bypass or Roux-en-Y surgery have increased release of gastrointestinal hormones. One possible mechanism for this increase is the rapid transit of nutrients into the intestine after eating. To determine whether there is increased secretion of anorectic peptides produced in the distal small intestine when this portion of the gut is given greater exposure to nutrients, we preformed ileal transpositions (IT) in rats. In this procedure, an isolated segment of ileum is transposed to the jejunum, resulting in an intestinal tract of normal length but an alteration in the normal distribution of endocrine cells along the gut. Rats with IT lost more weight ( P < 0.05) and consumed less food ( P < 0.05) than control rats with intestinal transections and reanastomosis without transposition. Weight loss in the IT rats was not due to malabsorption of nutrients. However, transposition of distal gut to a proximal location caused increased synthesis and release of the anorectic ileal hormones glucagon-like peptide-1 (GLP-1) and peptide YY (PYY; P < 0.01). The association of weight loss with increased release of GLP-1 and PYY suggests that procedures that promote gastrointestinal endocrine function can reduce energy intake. These findings support the importance of evaluating the contribution of gastrointestinal hormones to the weight loss seen with bariatric surgery.
Differential expression of Kv4 pore-forming and KChIP auxiliary subunits in rat uterus during pregnancy
Authors: Suzuki Takahiro , Takimoto Koichi
Published: September 2004

Regulation of voltage-gated K+(Kv) channel expression may be involved in controlling contractility of uterine smooth muscle cells during pregnancy. Functional expression of these channels is not only controlled by the levels of pore-forming subunits, but requires their association with auxiliary subunits. Specifically, rapidly inactivating Kvcurrent is prominent in myometrial cells and may be carried by complexes consisting of Kv4 pore-forming and KChIP auxiliary subunits. To determine the molecular identity of the channel complexes and their changes during pregnancy, we examined the expression and localization of these subunits in rat uterus. RT-PCR analysis revealed that rat uterus expressed all three Kv4 pore-forming subunits and KChIP2 and -4 auxiliary subunits. The expression of mRNAs for these subunits was dynamically and region selectively regulated during pregnancy. In the corpus, Kv4.2 mRNA level increased before parturition, whereas the expression of Kv4.1 and Kv4.3 mRNAs decreased during pregnancy. A marked increase in KChIP2 mRNA level was also seen at late gestation. In the cervix, the expression of all three pore-forming and two auxiliary subunit mRNAs increased at late gestation. Immunoprecipitaton followed by immunoblot analysis indicated that Kv4.2-KChIP2 complexes were significant in uterus at late pregnancy. Kv4.2- and KChIP2-immunoreactive proteins were present in both circular and longitudinal myometrial cells. Finally, Kv4.2 and KChIP2 mRNA levels were similarly elevated in pregnant and nonpregnant corpora of one side-conceived rats. These results suggest that diffusible factors coordinate the pregnancy-associated changes in molecular compositions of myometrial Kv4-KChIP channel complexes.
Heart-type fatty acid-binding protein reciprocally regulates glucose and fatty acid utilization during exercise
Authors: Shearer Jane , Fueger Patrick T. , Rottman Jeffrey N. , Bracy Deanna P. , Binas Bert , Wasserman David H.
Published: September 2004

The role of heart-type cytosolic fatty acid-binding protein (H-FABP) in mediating whole body and muscle-specific long-chain fatty acid (LCFA) and glucose utilization was examined using exercise as a phenotyping tool. Catheters were chronically implanted in a carotid artery and jugular vein of wild-type (WT, n = 8), heterozygous (H-FABP+/−, n = 8), and null (H-FABP−/−, n = 7) chow-fed C57BL/6J mice, and mice were allowed to recover for 7 days. After a 5-h fast, conscious, unrestrained mice were studied during 30 min of treadmill exercise (0.6 mph). A bolus of [125I]-15-( p-iodophenyl)-3- R, S-methylpentadecanoic acid and 2-deoxy-[3H]glucose was administered to obtain rates of whole body metabolic clearance (MCR) and indexes of muscle LCFA (Rf) and glucose (Rg) utilization. Fasting, nonesterified fatty acids (mM) were elevated in H-FABP−/− mice (2.2 ± 0.9 vs. 1.3 ± 0.1 and 1.3 ± 0.2 for WT and H-FABP+/−). During exercise, blood glucose (mM) increased in WT (11.7 ± 0.8) and H-FABP+/− (12.6 ± 0.9) mice, whereas H-FABP−/− mice developed overt hypoglycemia (4.8 ± 0.8). Examination of tissue-specific and whole body glucose and LCFA utilization demonstrated a dependency on H-FABP with exercise in all tissues examined. Reductions in H-FABP led to decreasing exercise-stimulated Rf and increasing Rg with the most pronounced effects in heart and soleus muscle. Similar results were seen for MCR with decreasing LCFA and increasing glucose clearance with declining levels of H-FABP. These results show that, in vivo, H-FABP has reciprocal effects on glucose and LCFA utilization and whole body fuel homeostasis when metabolic demands are elevated by exercise.
Omi/HtrA2 protease mediates cisplatin-induced cell death in renal cells
Authors: Cilenti Lucia , Kyriazis George A. , Soundarapandian Mangala M. , Stratico Valerie , Yerkes Adam , Park Kwon Moo , Sheridan Alice M. , Alnemri Emad S. , Bonventre Joseph V. , Zervos Antonis S.
Published: September 2004

Omi/HtrA2 is a mitochondrial proapoptotic serine protease that is able to induce both caspase-dependent and caspase-independent cell death. After apoptotic stimuli, Omi is released to the cytoplasm where it binds and cleaves inhibitor of apoptosis proteins. In this report, we investigated the role of Omi in renal cell death following cisplatin treatment. Using primary mouse proximal tubule cells, as well as established renal cell lines, we show that the level of Omi protein is upregulated after treatment with cisplatin. This upregulation is followed by the release of Omi from mitochondria to the cytoplasm and degradation of XIAP. Reducing the endogenous level of Omi protein using RNA interference renders renal cells resistant to cisplatin-induced cell death. Furthermore, we show that the proteolytic activity of Omi is necessary and essential for cisplatin-induced cell death in this system. When renal cells are treated with Omi's specific inhibitor, ucf-101, they become significantly resistant to cisplatin-induced cell death. Ucf-101 was also able to minimize cisplatin-induced nephrotoxic injury in animals. Our results demonstrate that Omi is a major mediator of cisplatin-induced cell death in renal cells and suggest a way to limit renal injury by specifically inhibiting its proteolytic activity.
Phosphatonin washout inHypmice proximal tubules: evidence for posttranscriptional regulation
Authors: Baum Michel , Moe Orson W. , Zhang Jianning , Dwarakanath Vangipuram , Quigley Raymond
Published: September 2004

X-linked hypophosphatemia is the most common inherited form of rickets. It is characterized by renal phosphate wasting, leading to hypophosphatemia and an inappropriately normal or low serum level of 1,25(OH)2vitamin D. Previous studies have pointed to a circulating factor or phosphatonin-inhibiting phosphate transport by decreasing mRNA of the proximal tubule NaPicotransporter NaPi-2A. The present study examined the hypothesis that there was also posttranscriptional regulation of the NaPi-2A cotransporter in Hyp mice proximal tubules and whether the phosphate transport defect in Hyp mice persisted when they were studied in vitro. We found that the rate of phosphate transport in Hyp mice was <50% that in C57/B6 control mice. While phosphate transport remained stable during incubation with time in C57/B6 mice proximal tubules, it increased from 0.46 ± 0.47 to 1.83 ± 0.40 pmol·mm−1·min−1in Hyp proximal tubules ( P < 0.01) consistent with phosphatonin washout in Hyp proximal tubules perfused in vitro. This time-dependent increase in phosphate transport was still observed in the presence of cycloheximide. There was also a reduction of proximal tubule apical NaPi-2A expression from Hyp mice compared with C57/B6 mice using single-tubule immunohistochemistry. Using immunohistochemistry, we demonstrate an increase in apical expression of the NaPi-2A transporter in proximal tubules perfused in vitro in Hyp mice even in the presence of bath cycloheximide. The increase in apical expression of the NaPi-2A transporter in proximal tubules perfused in vitro in Hyp mice was blocked by colchicine. These data are consistent with a rapidly reversible posttranscriptional defect in Hyp mice causing a reduction in phosphate transport.
Inhibition of ROMK potassium channel by syntaxin 1A
Authors: Sun Tie-Jun , Zeng Wei-Zhong , Huang Chou-Long
Published: September 2004

ROMK potassium channels are present in the cortical collecting duct (CCD) of the kidney and serve as apical exit pathways for K+secretion in this nephron segment. K+secretion in the CCD is regulated by multiple factors. In this study, we show that syntaxin 1A, but not syntaxin 3 or 4, inhibited whole cell ROMK currents in Xenopus laevis oocytes. Syntaxin 1A, but not syntaxin 3 or 4, interacted with the COOH-terminal cytoplasmic domain of ROMK in intro. Coexpression with synaptobrevin 2 reversed inhibition of whole cell ROMK currents by syntaxin 1A. In excised inside-out membranes of oocytes, application of fusion proteins containing the cytoplasmic region of syntaxin 1A to the cytoplasmic face caused a dose-dependent inhibition of ROMK. We further examined regulation of the K+channels in the CCD by syntaxin 1A. Application of botulinum toxin C1 to the excised inside-out membranes of the CCD caused an increase in the activity of K+channels. In contrast, application of toxin B had no effects. These results suggest that syntaxin 1A causes a tonic inhibition of the K+channels in the apical membrane of the CCD. Binding of synaptobrevin 2 to syntaxin 1A during docking and fusion of transport vesicles to the plasma membranes of CCD may lead to activation of these channels.
Fast Adaptation of the Internal Model of Gravity for Manual Interceptions: Evidence for Event-Dependent Learning
Authors: Zago Myrka , Bosco Gianfranco , Maffei Vincenzo , Iosa Marco , Ivanenko Yuri P. , Lacquaniti Francesco
Published: September 2004

We studied how subjects learn to deal with two conflicting sensory environments as a function of the probability of each environment and the temporal distance between repeated events. Subjects were asked to intercept a visual target moving downward on a screen with randomized laws of motion. We compared five protocols that differed in the probability of constant speed (0 g) targets and accelerated (1 g) targets. Probability ranged from 9 to 100%, and the time interval between consecutive repetitions of the same target ranged from about 1 to 20 min. We found that subjects systematically timed their responses consistent with the assumption of gravity effects, for both 1 and 0 g trials. With training, subjects rapidly adapted to 0 g targets by shifting the time of motor activation. Surprisingly, the adaptation rate was independent of both the probability of 0 g targets and their temporal distance. Very few 0 g trials sporadically interspersed as catch trials during immersive practice with 1 g trials were sufficient for learning and consolidation in long-term memory, as verified by retesting after 24 h. We argue that the memory store for adapted states of the internal gravity model is triggered by individual events and can be sustained for prolonged periods of time separating sporadic repetitions. This form of event-related learning could depend on multiple-stage memory, with exponential rise and decay in the initial stages followed by a sample-and-hold module.