bluuebunny/crossref_metadata_2025 huggingface dataset:
Chemical Analysis of Single Cells
Authors: Borland Laura M. , Kottegoda Sumith , Phillips K. Scott , Allbritton Nancy L.
Published: May 2008

Chemical analysis of single cells requires methods for quickly and quantitatively detecting a diverse array of analytes from extremely small volumes (femtoliters to nanoliters) with very high sensitivity and selectivity. Microelectrophoretic separations, using both traditional capillary electrophoresis and emerging microfluidic methods, are well suited for handling the unique size of single cells and limited numbers of intracellular molecules. Numerous analytes, ranging from small molecules such as amino acids and neurotransmitters to large proteins and subcellular organelles, have been quantified in single cells using microelectrophoretic separation techniques. Microseparation techniques, coupled to varying detection schemes including absorbance and fluorescence detection, electrochemical detection, and mass spectrometry, have allowed researchers to examine a number of processes inside single cells. This review also touches on a promising direction in single cell cytometry: the development of microfluidics for integrated cellular manipulation, chemical processing, and separation of cellular contents.
Chemical Cytometry: Fluorescence-Based Single-Cell Analysis
Authors: Cohen Daniella , Dickerson Jane A. , Whitmore Colin D. , Turner Emily H. , Palcic Monica M. , Hindsgaul Ole , Dovichi Norman J.
Published: May 2008

Cytometry deals with the analysis of the composition of single cells. Flow and image cytometry employ antibody-based stains to characterize a handful of components in single cells. Chemical cytometry, in contrast, employs a suite of powerful analytical tools to characterize a large number of components. Tools have been developed to characterize nucleic acids, proteins, and metabolites in single cells. Whereas nucleic acid analysis employs powerful polymerase chain reaction–based amplification techniques, protein and metabolite analysis tends to employ capillary electrophoresis separation and ultrasensitive laser-induced fluorescence detection. It is now possible to detect yoctomole amounts of many analytes in single cells.
Terrestrial Analysis of the Organic Component of Comet Dust
Authors: Sandford Scott A.
Published: May 2008

The nature of cometary organics is of great interest, both because these materials are thought to represent a reservoir of the original carbon-containing materials from which everything else in our solar system was made and because these materials may have played key roles in the origin of life on Earth. Because these organic materials are the products of a series of universal chemical processes expected to operate in the interstellar media and star-formation regions of all galaxies, the nature of cometary organics also provides information on the composition of organics in other planetary systems and, by extension, provides insights into the possible abundance of life elsewhere in the universe. Our current understanding of cometary organics represents a synthesis of information from telescopic and spacecraft observations of individual comets, the study of meteoritic materials, laboratory simulations, and, now, the study of samples collected directly from a comet, Comet P81/Wild 2.
A Personal Journey of Discovery: Developing Technology and Changing Biology
Authors: Hood Lee
Published: May 2008

This autobiographical article describes my experiences in developing chemically based, biological technologies for deciphering biological information: DNA, RNA, proteins, interactions, and networks. The instruments developed include protein and DNA sequencers and synthesizers, as well as ink-jet technology for synthesizing DNA chips. Diverse new strategies for doing biology also arose from novel applications of these instruments. The functioning of these instruments can be integrated to generate powerful new approaches to cloning and characterizing genes from a small amount of protein sequence or to using gene sequences to synthesize peptide fragments so as to characterize various properties of the proteins. I also discuss the five paradigm changes in which I have participated: the development and integration of biological instrumentation; the human genome project; cross-disciplinary biology; systems biology; and predictive, personalized, preventive, and participatory (P4) medicine. Finally, I discuss the origins, the philosophy, some accomplishments, and the future trajectories of the Institute for Systems Biology.
Protein Design by Directed Evolution
Authors: Jäckel Christian , Kast Peter , Hilvert Donald
Published: May 2008

While nature evolved polypeptides over billions of years, protein design by evolutionary mimicry is progressing at a far more rapid pace. The mutation, selection, and amplification steps of the evolutionary cycle may be imitated in the laboratory using existing proteins, or molecules created de novo from random sequence space, as starting templates. However, the astronomically large number of possible polypeptide sequences remains an obstacle to identifying and isolating functionally interesting variants. Intelligently designed libraries and improved search techniques are consequently important for future advances. In this regard, combining experimental and computational methods holds particular promise for the creation of tailored protein receptors and catalysts for tasks unimagined by nature.
The Protein Folding Problem
Authors: Dill Ken A. , Ozkan S. Banu , Shell M. Scott , Weikl Thomas R.
Published: May 2008

The “protein folding problem” consists of three closely related puzzles: (a) What is the folding code? (b) What is the folding mechanism? (c) Can we predict the native structure of a protein from its amino acid sequence? Once regarded as a grand challenge, protein folding has seen great progress in recent years. Now, foldable proteins and nonbiological polymers are being designed routinely and moving toward successful applications. The structures of small proteins are now often well predicted by computer methods. And, there is now a testable explanation for how a protein can fold so quickly: A protein solves its large global optimization problem as a series of smaller local optimization problems, growing and assembling the native structure from peptide fragments, local structures first.
Acquired obesity and poor physical fitness impair expression of genes of mitochondrial oxidative phosphorylation in monozygotic twins discordant for obesity
Authors: Mustelin Linda , Pietiläinen Kirsi H. , Rissanen Aila , Sovijärvi Anssi R. , Piirilä Päivi , Naukkarinen Jussi , Peltonen Leena , Kaprio Jaakko , Yki-Järvinen Hannele
Published: May 2008

Defects in expression of genes of oxidative phosphorylation in mitochondria have been suggested to be a key pathophysiological feature in familial insulin resistance. We examined whether such defects can arise from lifestyle-related factors alone. Fourteen obesity-discordant (BMI difference 5.2 ± 1.8 kg/m2) and 10 concordant (1.0 ± 0.7 kg/m2) monozygotic (MZ) twin pairs aged 24–27 yr were identified among 658 MZ pairs in the population-based FinnTwin16 study. Whole body insulin sensitivity was measured using the euglycemic hyperinsulinemic clamp technique. Transcript profiles of mitochondrial genes were compared using microarray data of fat biopsies from discordant twins. Body composition of twins was determined using DEXA and maximal oxygen uptake (V̇o2max) and working capacity (Wmax) using a bicycle ergometer exercise test with gas exchange analysis. The obese cotwins had lower insulin sensitivity than their nonobese counterparts (M value 6.1 ± 2.0 vs. 9.2 ± 3.2 mg·kg LBM−1·min−1, P < 0.01). Transcript levels of genes involved in the oxidative phosphorylation pathway (GO:0006119) in adipose tissue were lower ( P < 0.05) in the obese compared with the nonobese cotwins. The obese cotwins were also less fit, as measured by V̇o2max (50.6 ± 6.5 vs. 54.2 ± 6.4 ml·kg LBM−1·min−1, for obese vs. nonobese, P < 0.05), Wmax (3.9 ± 0.5 vs. 4.4 ± 0.7 W/kg LBM, P < 0.01) and also less active, by the Baecke leisure time physical activity index (2.8 ± 0.5 vs. 3.3 ± 0.6, P < 0.01). This implies that acquired poor physical fitness is associated with defective expression of the oxidative pathway components in adipose tissue mitochondria.
Systemic arterial compliance, systemic vascular resistance, and effective arterial elastance during exercise in endurance-trained men
Authors: Otsuki Takeshi , Maeda Seiji , Iemitsu Motoyuki , Saito Yoko , Tanimura Yuko , Ajisaka Ryuichi , Miyauchi Takashi
Published: May 2008

Systemic arterial compliance (C) and vascular resistance (R) regulate effective arterial elastance (Ea), an index of artery load. Increases in Ea during exercise are due primarily to reductions of C and maintain optimal ventricular-arterial coupling. Because C at rest and left ventricular functional reserve are greater in endurance-trained (ET) compared with sedentary control (SC) humans, we hypothesized that reductions of C and increases in Ea are greater in ET than SC individuals. The aim of this study was to investigate C, R, and Ea during exercise in ET and SC humans. C, R, Ea, and cardiac cycle length (T) were measured at rest and during exercise of 40, 60, and 80% maximal oxygen uptake using Doppler ultrasonography in 12 SC and 13 ET men. C decreased in an exercise intensity-dependent manner in both groups, but its reductions were greater in the ET than SC subjects. Consequently, although C at rest was greater in the ET than SC group, the intergroup difference in C disappeared during exercise. Exercise-related changes in R/T were relatively slight and R/T was lower in the ET than the SC group, both at rest and during exercise. Although Ea at rest was lower in the ET than SC group, there were no intergroup differences in Ea at 40, 60, or 80% maximal oxygen uptake. We conclude that the reductions of C from rest to exercise are more marked in ET than SC humans. This may be related to the exercise-associated disappearance of the difference in Ea between ET and SC humans.
An In Vitro Protocol for Recording From Spinal Motoneurons of Adult Rats
Authors: Carp Jonathan S. , Tennissen Ann M. , Mongeluzi Donna L. , Dudek Christopher J. , Chen Xiang Yang , Wolpaw Jonathan R.
Published: May 2008

In vitro slice preparations of CNS tissue are invaluable for studying neuronal function. However, up to now, slice protocols for adult mammal spinal motoneurons—the final common pathway for motor behaviors—have been available for only limited portions of the spinal cord. In most cases, these preparations have not been productive due to the poor viability of motoneurons in vitro. This report describes and validates a new slice protocol that for the first time provides reliable intracellular recordings from lumbar motoneurons of adult rats. The key features of this protocol are: preexposure to 100% oxygen; laminectomy prior to perfusion; anesthesia with ketamine/xylazine; embedding the spinal cord in agar prior to slicing; and, most important, brief incubation of spinal cord slices in a 30% solution of polyethylene glycol to promote resealing of the many motoneuron dendrites cut during sectioning. Together, these new features produce successful recordings in 76% of the experiments and an average action potential amplitude of 76 mV. Motoneuron properties measured in this new slice preparation (i.e., voltage and current thresholds for action potential initiation, input resistance, afterhyperpolarization size and duration, and onset and offset firing rates during current ramps) are comparable to those recorded in vivo. Given the mechanical stability and precise control over the extracellular environment afforded by an in vitro preparation, this new protocol can greatly facilitate electrophysiological and pharmacological study of these uniquely important neurons and other delicate neuronal populations in adult mammals.
Validating the genomic signature of pediatric septic shock
Authors: Cvijanovich Natalie , Shanley Thomas P. , Lin Richard , Allen Geoffrey L. , Thomas Neal J. , Checchia Paul , Anas Nick , Freishtat Robert J. , Monaco Marie , Odoms Kelli , Sakthivel Bhuvaneswari , Wong Hector R.
Published: May 2008

We previously generated genome-wide expression data (microarray) from children with septic shock having the potential to lead the field into novel areas of investigation. Herein we seek to validate our data through a bioinformatic approach centered on a validation patient cohort. Forty-two children with a clinical diagnosis of septic shock and 15 normal controls served as the training data set, while 30 separate children with septic shock and 14 separate normal controls served as the test data set. Class prediction modeling using the training data set and the previously reported genome-wide expression signature of pediatric septic shock correctly identified 95–100% of controls and septic shock patients in the test data set, depending on the class prediction algorithm and the gene selection method. Subjecting the test data set to an identical filtering strategy as that used for the training data set, demonstrated 75% concordance between the two gene lists. Subjecting the test data set to a purely statistical filtering strategy, with highly stringent correction for multiple comparisons, demonstrated <50% concordance with the previous gene filtering strategy. However, functional analysis of this statistics-based gene list demonstrated similar functional annotations and signaling pathways as that seen in the training data set. In particular, we validated that pediatric septic shock is characterized by large-scale repression of genes related to zinc homeostasis and lymphocyte function. These data demonstrate that the previously reported genome-wide expression signature of pediatric septic shock is applicable to a validation cohort of patients.
Characterization of the acute temporal changes in excisional murine cutaneous wound inflammation by screening of the wound-edge transcriptome
Authors: Roy Sashwati , Khanna Savita , Rink Cameron , Biswas Sabyasachi , Sen Chandan K.
Published: May 2008

This work represents a maiden effort to systematically screen the transcriptome of the healing wound-edge tissue temporally using high-density GeneChips. Changes during the acute inflammatory phase of murine excisional wounds were characterized histologically. Sets of genes that significantly changed in expression during healing could be segregated into the following five sets: up-early (6–24 h; cytokine-cytokine receptor interaction pathway), up-intermediary (12–96 h; leukocyte-endothelial interaction pathway), up-late (48–96 h; cell-cycle pathway), down-early (6–12 h; purine metabolism) and down-intermediary (12–96 h; oxidative phosphorylation pathway). Results from microarray and real-time PCR analyses were consistent. Results listing all genes that were significantly changed at any specific time point were further mined for cell-type (neutrophils, macrophages, endothelial, fibroblasts, and pluripotent stem cells) specificity. Candidate genes were also clustered on the basis of their functional annotation, linking them to inflammation, angiogenesis, reactive oxygen species (ROS), or extracellular matrix (ECM) categories. Rapid induction of genes encoding NADPH oxidase subunits and downregulation of catalase in response to wounding is consistent with the fact that low levels of endogenous H2O2is required for wound healing. Angiogenic genes, previously not connected to cutaneous wound healing, that were induced in the healing wound-edge included adiponectin, epiregulin, angiomotin, Nogo, and VEGF-B. This study provides a digested database that may serve as a valuable reference tool to develop novel hypotheses aiming to elucidate the biology of cutaneous wound healing comprehensively.
Genomic dissection of the cytokine-controlled STAT5 signaling network in liver
Authors: Hosui Atsushi , Hennighausen Lothar
Published: May 2008

Growth hormone (GH) controls the physiology and pathophysiology of the liver, and its signals are conducted by two members of the family of signal transducers and activators of transcription, STAT5A and STAT5B. Mice in which the Stat5a/b locus has been inactivated specifically in hepatocytes display GH resistance, the sex-specific expression of genes associated with liver metabolism and the cytochrome P-450 system is lost, and they develop hepatosteatosis. Several groups have shown by global gene expression profiling that a cadre of STAT5A/B target genes identify genetic cascades induced by GH and other cytokines. Evidence is accumulating that in the absence of STAT5A/B GH aberrantly activates STAT1 and STAT3 and their downstream target genes and thereby offers a partial explanation of some of the physiological alterations observed in Stat5a/b-null mice and human patients. We hypothesize that phenotypic changes observed in the absence of STAT5A/B are due to two distinct molecular consequences: first, the failure of STAT5A/B target genes to be activated by GH and second, the rerouting of GH signaling to other members of the STAT family. Rerouting of GH signaling to STAT1 and STAT3 might partially compensate for the loss of STAT5A/B, but it certainly activates biological programs distinct from STAT5A/B. Here we discuss the extent to which studies on global gene expression profiling have fostered a better understanding of the biology behind cytokine-STAT5A/B networks in hepatocytes. We also explore whether this wealth of information on gene activity can be used to further understand the roles of cytokines in liver disease.
Predictors and Non-Predictors of Symptom Relief in Dyspepsia Consultations in Primary Care
Authors: Agréus Lars , Talley Nicholas J. , Sheen Adrian , Johansson Sven-Erik , Jones Michael P. , Svärdsudd Kurt
Published: May 2008

Objective: We aimed to evaluate if the course of dyspepsia is influenced by medical consultation in primary care. Design, Setting and Patients: Australian general practitioners (n = 27) recruited 157 dyspeptic patients, of whom 94 were eligible for follow-up. Dyspepsia, comorbidity, quality of life, emotional status, locus of control and consultation satisfaction were measured at baseline and follow-up (mean 3 months). Main Outcome Measure: Response was defined as improvement of dyspepsia over time on the Nepean Dyspepsia Index score. Results: Dyspepsia improved in 82% (n = 77). There was no significant change in non-gastrointestinal symptoms. Half were worried or stressed by their symptoms, and 85% wanted reassurance, a need that (univariately) differentiated responders from non-responders (p = 0.02). Most patients seen in primary care with dyspepsia improved. If the doctor believed it was likely that the patient would follow their recommendations, the patient was nearly five times as likely to be a responder (OR 4.9, 95% CI 1.2–19.0). The only other significant predictor was acid suppression therapy (OR 3.5, 95% CI 1.1–10.9). Conclusion: Most primary care visits for dyspepsia are followed by improvement, which may be predicted in part by indicators of patient compliance. Prescription of acid suppression therapy may also improve outcome in dyspepsia.
An International Comparison of the Burden of Illness in Patients with Dyspepsia
Authors: Halling Katarina , Kulich Károly , Carlsson Jonas , Wiklund Ingela
Published: May 2008

Background/Aims: This study investigates the symptoms and the impact of symptoms on health-related quality of life (HRQL) in patients consulting with dyspepsia. Methods: Consecutive patients with a diagnosis of dyspepsia were recruited from primary and secondary care in Germany, Hungary, Italy, Poland, South Africa and Spain. Investigators assessed symptom frequency and severity, and subjects completed the following questionnaires: the Gastrointestinal Symptom Rating Scale (GSRS), the Quality of Life in Reflux and Dyspepsia (QOLRAD) questionnaire, the Hospital Anxiety and Depression (HAD) scale and the Short Form 36 (SF-36). Results: 853 dyspepsia patients were included. Mean GSRS scores showed that patients were most troubled by abdominal pain and indigestion. QOLRAD scores indicated that symptoms caused emotional distress, food/drink problems and reduced vitality, with a lesser effect on sleep and physical functioning. Mean SF-36 scores were lower than mean normative values for all domains, indicating that patients had a worse HRQL than the normal population, particularly for Bodily Pain, Role Physical and Role Emotional. Of patients in each country, 18–43% were anxious and 11–21% were depressed. Conclusions: Patients with dyspepsia have reduced HRQL because their symptoms – particularly abdominal pain and indigestion – cause emotional distress, problems with food and drink, and impaired vitality.
Expression of α-AR Subtypes in T Lymphocytes and Role of the α-ARs in Mediating Modulation of T Cell Function
Authors: Bao Jing-Yin , Huang Yan , Wang Feng , Peng Yu-Ping , Qiu Yi-Hua
Published: May 2008

Objectives: Previous work in our laboratory has shown that α-adrenoreceptors (α-ARs) and β-ARs exist on lymphocytes from functional profile, and that the receptors mediate the regulation of lymphocyte function by catecholamines. In the present study, we directly examined the expression of α-AR subtypes, α1-AR and α2-AR mRNAs, in T lymphocytes and explored the roles of the α-AR subtypes and intracellular signal transduction mechanisms linked to the receptors in mediating the modulation of T lymphocyte function. Methods: T lymphocytes from mesenteric lymph nodes of rats were purified by using a nylon wool column. Reverse transcription polymerase chain reaction was used to detect the expression of α1-AR and α2-AR mRNAs in the freshly isolated T cells and the mitogen concanavalin A (Con A)-activated lymphocytes. Colorimetric methylthiazoletetrazolium assay was employed to measure lymphocyte proliferation induced by Con A. Interferon-γ (IFN-γ) and interleukin-4 (IL-4) levels in the Con A-stimulated lymphocyte culture supernatants were examined by enzyme-linked immunosorbent assay. Results: T cells expressed both α1-AR and α2-AR mRNAs. The expression of both α1-AR and α2-AR mRNAs was significantly higher in the Con A-activated lymphocytes than in the resting lymphocytes. Phenylephrine, a selective α1-AR agonist, had no evident effect on lymphocyte proliferation nor on IFN-γ and IL-4 production induced by Con A. However, the selective α2-AR agonist clonidine attenuated Con A-induced lymphocyte proliferation as well as IFN-γ and IL-4 production. The inhibited lymphocyte proliferation and IFN-γ and IL-4 production by clonidine were blocked by yohimbine, an α2-AR antagonist. Either phospholipase C inhibitor U-73122 or protein kinase C inhibitor chelerythrine partially prevented the suppressive effect of clonidine on Con A-stimulated lymphocyte proliferation and IL-4 production. Conclusions: T lymphocytes express both α1-ARs and α2-ARs, but only the α2-ARs participate in the suppressive modulation of lymphocyte proliferation and cytokine production in vitro. The inhibitory effect of α2-AR stimulation on lymphocyte function is partially mediated via the phospholipase C-protein kinase C pathway.
Multifractal Description of the Maternal Surface of the Placenta
Authors: Kikuchi Akihiko , Unno Nobuya , Shiba Masahiro , Sunagawa Sorahiro , Ogiso Yoshifumi , Kozuma Shiro , Taketani Yuji
Published: May 2008

Background: Recently, multifractal analysis based on generalized concepts of fractals has been applied to biological tissues composed of complex structures. Methods: Using digitized images of the maternal surface of 278 placentas, multifractal parameters were measured with a fractal analysis software. Results: The values of αmin, α(0), αmax and the degree of multifractality given by the αmax – αmin difference calculated from 278 placentas were 1.840 ± 0.068, 2.089 ± 0.034, 2.856 ± 0.128 and 1.017 ± 0.136, respectively. A significant decrease of αmin and as a consequence a significant increase in the degree of multifractality were observed according to gestational age. The α(0) value of the placenta complicated by pregnancy-induced hypertension (PIH) was significantly higher than that without PIH. The αmin and α(0) values of the placenta having intrauterine growth restriction (IUGR) were significantly higher than those without IUGR. On the other hand, the presence of chorioamnionitis did not change multifractal properties of the maternal surface of the placenta. Conclusion: The multifractal parameters may be objective indices of the heterogeneity or complexity of the macroscopic morphology of the maternal surface of the placenta. Multifractal analysis holds a promise for quantitatively evaluating physiological and pathological development of the placenta.
Effect of Low Molecular Weight Fucoidan and Low Molecular Weight Heparin in a Rabbit Model of Arterial Thrombosis
Authors: Durand Eric , Helley Dominique , Al Haj Zen Ayman , Dujols Céline , Bruneval Patrick , Colliec-Jouault Sylvia , Fischer Anne-Marie , Lafont Antoine
Published: May 2008

Background: Therapeutic use of unfractionated heparin and low molecular weight heparins (LMWHs) is limited by hemorrhagic adverse effects. We compared the antithrombotic effect of LMW fucoidan (LMWF) and LMWH in an experimental model. Methods: Thrombosis was induced in femoral arteries of male New Zealand White rabbits by in situ induction of endothelial apoptosis with staurosporine (10–5M for 30 min). Starting the day before apoptosis induction, the animals received subcutaneous LMWF (15 mg/kg), LMWH (enoxaparin 2.5 mg/kg) or saline solution (control group) twice a day for 4 days. Results: The degrees of apoptosis and endothelial denudation were similar in the 3 groups. The thrombotic score was significantly lower in the LMWF group than in the LMWH and control groups (p = 0.01). Tissue factor expression was significantly lower in the LMWF group than in the control and LMWH groups (p = 0.01). The plasma concentration of tissue factor pathway inhibitor was significantly increased after LMWF injection (137 ± 28 vs. 102 ± 17; p = 0.01), whereas no change was observed after LMWH treatment. LMWF did not prolong the bleeding time or decrease platelet aggregation. Conclusions: LMWF appeared to be more effective than LMWH for preventing arterial thrombosis in this experimental model. LMWF also had a lower hemorrhagic risk than LMWH.
CSF/Serum Folate Gradient: Physiology and Determinants with Special Reference to Dementia
Authors: Hagnelius Nils-Olof , Wahlund Lars-Olof , Nilsson Torbjörn K.
Published: May 2008

Background: Folate depletion has been implicated as a risk factor for neurodegenerative disorders. We hypothesized that transport of folate to the cerebrospinal fluid (CSF) compartment could be involved in the pathophysiology of these disorders. Methods: The CSF/serum folate gradient (RCSF/S) was studied in 205 subjects with suspected cognitive disorder. Its relation to clinical and biochemical indices, including the integrity of the blood-CSF barrier, were characterized. Results: In subjects who were diagnosed as nondemented (ND) the mean RCSF/S ± SD was 2.46 ± 0.62 versus 2.09 ± 0.67 (p = 0.008) in the dementia subgroup with a vascular component (VaD + mixed). The ND subgroup had higher CSF folate (p = 0.001) and lower serum homocysteine values (p = 0.001) than the VaD + mixed subgroup. The folate gradient RCSF/S was negatively correlated with serum folate (p < 0.001, R2 = 0.518) and to the albumin ratio, a blood-CSF barrier biomarker (β = –0.235). The Alzheimer patients had RCSF/S and albumin ratios similar to the ND subjects. Conclusion: The RCSF/S was significantly lower in the VaD + mixed dementia subgroup, suggestive of a defect in the transport of folate over the choroid plexus that seems to be characteristic of, and limited to, the VaD + mixed dementia subgroup.
Improved Outcome of Patients with Colorectal Cancer: The Ljubljana University Medical Centre Experience
Authors: Štor Z. , Jelenc F. , Juvan R. , Omejc M. , Bunc M. , Repše S.
Published: May 2008

Background/Aims: Analysis of outcome in patients undergoing resection for colorectal carcinoma. Methods: Between 1/1/1991 and 31/12/2000, 1,478 patients with a colon and rectal carcinoma underwent a potentially curative resection. The results were analyzed for two groups of patients given different treatment regimens during two consecutive 5-year periods. The 5-year survival rate was estimated by the Kaplan-Meier method. Results: Over a period of 10 years, 1,478 patients were treated by resection. The 5-year survival rate for R0 resected patients with stage I and stage III colon cancer in the period 1996–2000 was significantly higher than for patients operated on between 1991 and 1995 (stage I: 86 vs. 70%; stage III: 58 vs. 40%). Similarly, the 5-year survival rate for R0 resected patients with stage III rectal cancer between 1996 and 2000 was significantly better than that for patients operated on during the early period (58 vs. 31%). Conclusions: Patients who underwent R0 resection for colorectal cancer during the period 1995–2000 showed a significantly improved 5-year survival rate compared to those operated on between 1991 and 1995. Improved survival in these patients is to a great extent attributable to improvements in clinical practice combining surgery and adjuvant therapy.
Aortic Stiffness and Diastolic Flow Abnormalities in End-Stage Renal Disease Assessed by Magnetic Resonance Imaging
Authors: Doyle Arthur , Mark Patrick B. , Johnston Nicola , Foster John , Connell John M.C. , Dargie Henry , Jardine Alan , Padmanabhan Neal
Published: May 2008

Background: Arterial stiffness is associated with adverse cardiovascular outcomes, particularly in end-stage renal disease (ESRD). One mechanism linking arterial stiffness with cardiovascular events may be the changes in pressure wave reflection on ventricular ejection and coronary perfusion during diastole. We illustrate this using MRI to describe aortic elastic properties and alterations of diastolic flow in comparison to derived central pressure characteristics. Methods: Ten patients with ESRD and ten control subjects were studied. Transverse images of the ascending aorta were obtained by cardiac MRI. Aortic distensibility was calculated using brachial pulse pressure. MRI flow maps were obtained from the ascending aorta and aortic pressure was calculated using SphygmoCor™. Results: ESRD patients had reduced aortic distensibility compared to the controls (median 0.00464 mm Hg–1 vs. 0.00152 mm Hg–1, p = 0.0057). Furthermore, in diastole, normal subjects show net reversal of blood flow in the ascending aorta, with a mean of –19.6 versus +7.6 ml/min in the ESRD group; p = 0.045. Conclusions: Using non-invasive methods we have demonstrated a marked reduction in aortic distensibility along with disturbances in aortic flow, providing insight into the pathophysiology of ventricular–vascular interaction. The normal group showed reversal of diastolic blood flow, which may have a direct relationship with coronary perfusion parameters, which was absent in the ESRD group.
Somatic cell genetics resource for research in aging
Authors: Murphy D.G. , Nichols W.W.
Published: May 2008

A mutant cell bank in support of research in aging has been established at the Institute for Medical Research, Camden, N.J. The bank is under contract support of the Adult Development and Aging Program of the National Institute of Child Health and Human Development. We anticipate that the bank, with associated services such as an annual workshop, will facilitate the growth of the NIH grant-supported cellular aging research program and thus contribute to the elucidation of mechanisms in human aging at the cellular and molecular level.
Reassessment of presumed Y/22 and Y/15 translocations in man using a new technique
Authors: Spowart G.
Published: May 2008

A new chromosome banding technique, distamycin A plus DAPI, has been used to reexamine cases of presumed Y/autosome translocations. In contrast with the results obtained with quinacrine fluorescence (Q-banding), the satellites of acrocentric chromosomes do not fluoresce brightly with this new (DA-DAPI) method, making it more specific for the long arm of the Y chromosome. Previous cases with intensely Q-fluorescent and abnormally long short arms on a chromosome 22 were considered as presumptive 22/Y translocations: The new technique clearly shows that, in these cases, the additional material on 22p is not derived from Yq. In contrast, in other cases the Yq nature of additional material on 15p, in conjunction with the presence of an extra Y-body in interphase nuclei and the presence of a male-specific DNA, supports the previous diagnosis of a presumptive 15/Y translocation.
Cytogenetics of somatic cell hybrids
Authors: Chen T.R.
Published: May 2008

Karyotypes of hybrid cells were studied in continuous uncloned cultures by Q- and C-bandings. Cultures were initiated by virus-mediated or spontaneous cell fusions from normal human diploid fibroblasts and mouse heteroploid RAG cells. Heterokaryons containing complete genomes of both parental cells randomly lost chromosomes from both species. The majority of cells in early growth stages, however, still possessed a nearly complete human genome. The rate of human chromosome loss in subsequent growth periods was not uniform, being gradual in some and rapid in others. The initially predominant 2n human-1s mouse (1h:1m) type was soon replaced by a less frequent 2n human-2s mouse (1h:2m) type. Over an increased period of time in mass culture, the number of stemlines decreased. One stemline, often a (1h:2m) type with a greatly reduced human complement, outgrew the others and occupied the entire culture. Therefore, the usual process of clonal isolation may confer a negative selection bias against cell hybrids retaining a large number of human chromosomes. Hybrid stemlines with stable karyotypes were established in the present HAT-agar selection system before 36 days after fusion had elapsed.
Chromosome markers in 12 inbred strains of the Norway rat, Rattus norvegicus
Authors: Sasaki M. , Kodama Y. , Hayata I. , Yoshida M.C.
Published: May 2008

Morphological details of metaphase chromosomes were compared among 12 inbred strains of rats (Rattus norvegicus) by means of conventional Giemsa staining and by a sequential Q- and C-banding method. Interstrain variations were found in seven pairs, as identified on the basis of size differences in the short arms and/or satellites of chromosomes 3 and 12 and the X chromosome and in the centromeric C-bands of chromosomes 4, 5, 7, and 9. All pairs were homomorphic in the inbred strains, while F1 hybrids between two inbred strains showed certain heteromorphic pairs expected from the parents. These chromosome markers appear to be useful for characterization of inbred strains as well as for various genetic studies, including linkage analyses.
New karyotypes and somatic and germ-cell banding in Akodon arviculoides (Rodentia, Cricetidae)
Authors: Yonenaga-Yassuda Y.
Published: May 2008

Chromosomal polymorphism resulting from three autosomal pericentric inversions and a complex rearrangement involving the largest chromosome of the complement (pair 1) in Akodon arviculoides (2n = 14, 15) is reported. G- and C-banding patterns in somatic and meiotic cells allowed the precise identification of all chromosomes and rearrangements. In meiosis of male specimens with 2n=15, a large trivalent reflecting the complex rearrangement in autosomal pair 1 was observed. Two possible explanations for it are discussed. G- and C-bands in diplotene cells in heterozygotes for the inversions showed different configurations depending on the pairing in the inverted segments. Chiasma frequency data fro three specimens are analyzed.
Effects of DAPI on human leukocytes in vitro
Authors: Rocchi A. , di Castro M. , Prantera G.
Published: May 2008

DAPI (4’-6-diamidino-2-phenylindole), a fluorochrome specific for AT-rich DNA, was supplied for 24 h at various concentrations to human leukocytes in culture. This treatment caused the appearance on the chromosomes of specific areas lacking spiralization. In particular, the centromeric regions of chromosomes 1, 9, and 16, a short region on the long arm of chromosomes 1 and 2, and the distal heterochromatic part of the long arm of the Y chromosome were despiralized. The despiralization pattern of DAPI is compared with those previously obtained with Hoechst 33258 and Distamycin A.
Colinearity in the mouse genome: a study of chromosome 2
Authors: Searle A.G. , Beechey C.V. , Eicher E.M. , Nesbitt M.N. , Washburn L.L.
Published: May 2008

The cytologic positions (determined by G-banding) of the breakpoints on mouse chromosome 2 of a series of ten reciprocal translocations were compared with their most probable genetic positions on the linkage map, as determined by studies on recombination with known chromosome 2 (= linkage group V) markers. The most probable proximal-distal orders of the genetic and cytologic breakpoints were found to be the same; i.e., the two sets of breakpoints were colinear. However, there was no close correspondence between these two measures of the distance apart of adjacent breakpoints, since some translocation breaks which were well separated in G-band positions seemed close together in terms of the linkage map, and vice versa. This helps to confirm Lyon’s conclusion that in certain mouse chromosomes, including No. 2, the distribution of chiasmata is non-random.
A case of trisomy 22 in Pongo pygmaeus
Authors: Andrle M. , Fiedler W. , Rett A. , Ambros P. , Schweizer D.
Published: May 2008

A behaviorally and clinically abnormal female orangutan was analyzed cytologically using general banding techniques and by an alkaline silver method for staining nucleolus organizer regions. The karyotype had 49 chromosomes, including an extra chromosome 22 (49, XX, + 22). No variant chromosome types or heterozygous structural rearrangements were found. Nine of the 14 large acrocentric chromosomes, Nos. 11–17, and three of the five presumptive human G-group equivalents, i.e., two of three chromosomes 22, and one chromosome from pair 23, exhibited positive silver staining of the nucleolus organizer region (NOR).
Demonstration of specific heterochromatic segments in the orangutan (Pongo pygmaeus) by a distamycin/DAPI double staining technique
Authors: Schweizer D. , Ambros P. , Andrle M. , Rett A. , Fiedler W.
Published: May 2008

Orangutan metaphase chromosomes, obtained from a female animal with trisomy 22, were stained by a recently developed distamycin/DAPI fluorescent technique which had been shown to differentiate specific C-bands on human chromosomes, as well as by other banding techniques. Distamycin/DAPI-brilliant fluorescence was observed in the short arm regions of acrocentric chromosomes 11–17, 22 and 23, and a brightly fluorescent paracentromeric band was seen on chromosome 8. A smaller amount of fluorescence was found adjacent to the centromere of most of the other chromosomes. Sequential distamycin/DAPI and Giemsa C-staining of the same metaphases revealed that the “hot-spots” on acrocentrics correspond to C-band material in their short arm. The less intensely fluorescent centric bands on other chromosomes coincide with centromeric C-bands. Reverse fluorescent staining of orangutan chromosomes with chromomycin A3 revealed brightly fluorescent regions at short arms of some acrocentrics probably confined to the satellite, either in a heteromorphic form (Nos. 11, 14, 17) or of similar size (No. 22).
A tdic(5;15)(p13;p11) chromosome showing variation for constriction in the centromeric regions in a patient with the cri du chat syndrome
Authors: Dewald G.W. , Boros S.J. , Conroy M.M. , Dahl R.J. , Spurbeck J.L. , Vitek H.A.
Published: May 2008

Some dicentric chromosomes show only one primary constriction at metaphase and behave in cell division as if they are monocentric. The few previous reports of tdic (translocation dicentric) chromosomes showing one morphologic centromere indicate that among the cells of an individual the same centromere consistently shows the primary constriction. The present case deals with a tdic(5;15)(pl3;pll) chromosome that is an exception to this pattern. Scoring 98 GTG-, C-, and QFQ-banded metaphases specifically for primary constrictions revealed 15 (15%) containing a tdic chromosome with a single primary constriction. Among these chromosomes, 8 (8%) were at the chromosome 15 centromere and 7 (7%) were at the chromosome 5 centromere. The remaining 83 (85%) tdic chromosomes showed two primary constrictions. We analyzed a total of 172 metaphases from peripheral blood, and all except 3 (1.7%) contained the tdic chromosome. Among these three cells, the tdic chromosome was broken in two and absent in one, which indicates that there was some unstable separation of this dicentric in cell division. In two metaphases, there was a chromatid gap at the site of one centromere. Possibly, the absence of certain primary constrictions was associated with deletion of centromeres. This mechanism may be a continual source for additional centromere inactivation during the life of this patient. This case demonstrates that for some dicentrics either centromere may become nonfunctional and inactivation can occur more than once within an individual. The karyotype of this patient was 45, XX, tdic(5;15)(pl3;pll). Thus, she was monosomic for about % of the chromosome 5 short arm. Clinically, this infant had a shrill catlike cry and facies of the cri du chat syndrome.
Confirmation of the assignment of the gene for galactose-1-phosphate uridylyltransferase (E.C. 2.7.7.12) to human chromosome 9
Authors: Benn P.A. , D’Ancona G.G. , Croce C.M. , Shows T.B. , Mellman W.J.
Published: May 2008

The gene for galactose-1-phosphate uridylyltransferase (GALT) has previously been assigned to human chromosomes 2, 3, and 9. We have studied a further series of human-mouse hybrids and are able to confirm that the human gene for GALT is located on human chromosome 9.
Sterility in hybrid cattle
Authors: Pathak S. , Kieffer N.M.
Published: May 2008

The distribution of constitutive heterochromatin and nucleolus organizer regions (NORs) in somatic as well as in meiotic chromosomes of Bos taurus, Bos banteng, Bison bison, and their hybrids are analyzed. C-bands are present in the centromeric regions of every autosome. The X chromosome does not show a distinct C-band in the centromeric region, whereas the Y chromosome contains an appreciable amount of C-band material. In somatic metaphases, NORs are present on the telomeric ends of five pairs of autosomes. During pachytene, five autosomal bivalents contain NORs on their terminal ends. Meiotic preparations made from sterile bulls did not contain stages beyond the degenerating pachytene, which after C-banding, more frequently showed clustering of heterochromatin than did the pachytene stage in normal bulls.
Heterogeneity of constitutive heterochromatin in somatic Syrian hamster chromosomes
Authors: Popescu N.C. , DiPaolo J.A.
Published: May 2008

Syrian hamster constitutive heterochromatin was analyzed for C-band distribution and for BrdU late-replication pattern. Characteristic for this species is relatively large amounts of sex-chromosome and autosomal heterochromatin. The distribution of constitutive heterochromatin was determined. The long arm of the X chromosome, the whole Y, the short arms of 8 autosomal pairs, the long arm of the smallest metacentric pair, and the centromeric regions of 12 pairs stained intensely dark on C-band preparations. In contrast to the heterochromatin in the centromeric regions, the autosomal short-arm heterochromatin has an increased susceptibility to the denaturation process, as indicated by prolonged exposure to NaOH or Ba(OH)2. Such further exposure to denaturing agents results in an intense dark stain only on the sex-chromosome heterochromatin and centromeric regions of the autosomes. The BrdU late-replication pattern demonstrated that the late-replicating regions correspond to C-bands. Centromeric regions replicate late in the S phase; however, no centromeric region is among the latest replicating segments of the complement. Centromeric and noncentromeric heterochromatin are two distinct categories of constitutive heterochromatin.
Aging and sister chromatid exchange
Authors: Nakanishi Y. , Kram D. , Schneider E.L.
Published: May 2008

Induction of sister chromatid exchanges (SCE’s) was examined in bone marrow cells of young and old C57BL/6J mice exposed to three different DNA-damaging agents (cyclophosphamide, mitomycin C, and doxorubicin). At low concentrations of all three mutagens, the levels of induced SCE’s were similar in young and old cell populations. However, at higher mutagen concentrations, SCE induction was significantly reduced in old cell populations. Studies of mice aged 5 to 32 months revealed that induced SCE frequencies remain stable during early adulthood (5 to 12 months) and then begin to decline as a function of age. These results indicate that with aging there exists a gradual alteration of cellular response to DNA damage.
Breeding studies reveal segregation of a canine Robertsonian translocation along Mendelian proportions
Authors: Larsen R.E. , Dias E. , Flores G. , Selden J.R.
Published: May 2008

Six matings of golden retriever-type mongrel dogs with a 13/23 Robertsonian translocation were studied. Three matings between normal dogs and dogs heterozygous for the translocation produced 12 normals and 11 heterozygotes. In three matings between heterozygotes, the distribution of normal, heterozygous, and homozygous progeny was Mendelian (8:12:5). No gross phenotypic anomalies were observed, with the exception of congenital inguinal hernia in two female homozygotes. Nondisjunction in the form of trisomic or monosomic individuals for either autosome 13 or 23 was not observed.
Assignment of a gene for uridine diphosphate galactose-4-epimerase to human chromosome 1 by somatic cell hybridization, with evidence for a regional assignment to 1pter→1p21
Authors: Benn P.A. , Shows T.B. , D’Ancona G.G. , Croce C.M. , Orkwiszewski K.G. , Mellman W.J.
Published: May 2008

The presence of human uridine diphosphate galactose-4-epimerase (GALE) was found to correlate with the presence of chromosome 1 in somatic cell hybrids between man and mouse. The gene for GALE can therefore be assigned to human chromosome 1. Using a chromosome 1 rearrangement, we have been able to regionally assign GALE to the pter→p21 region.
Chromosome studies on a human liposarcoma cell line
Authors: Bey E. , Bernstein R.
Published: May 2008

Numerical and structural chromosome analysis of a human retroperitoneal liposarcoma cell line maintained under standard cell culture conditions revealed a very stable hypodiploid mode. If the cells were not trypsinized for several generations, a near-triploid stemline, which was generally a duplication of the hypodiploid mode, emerged. Some chromosomes appeared to be relatively stable pairs (1, 2, 7, 9, and 12), but most had “lost” one homolog or both (4 and 21) or were rearranged into “new” marker chromosomes. Quantitation of the genetic material showed a loss of 12.0 ± 3.7% per spread. Only one characteristically long marker chromosome, which is present in every cell, could be identified with certainty as a translocation between chromosomes 4 and 11. Several of the marker chromosomes showed interstitial negatively staining regions with the trypsin-Giemsa method.
Sequential silver staining and hybridization in situ on nucleolus organizing regions in human cells
Authors: Warburton D. , Henderson A.S.
Published: May 2008

Chromosome preparations from eight individuals were first stained with silver nitrate to reveal the nucleolus organizing regions (NORs) and then hybridized in situ with ribosomal RNA. In six individuals the size of the silver-staining regions was positively correlated with the amount of label present after hybridization in situ. Thus the variation in silver-staining intensity among chromosomes was largely explained by variation in the number of rDNA gene copies per NOR. However, in two individuals this correlation was absent, suggesting that other factors can also influence the size of the silver-staining region.