bluuebunny/crossref_metadata_2025 huggingface dataset:
Colonic gene expression profile in NHE3-deficient mice: evidence for spontaneous distal colitis
Authors: Laubitz Daniel , Larmonier Claire B. , Bai Aiping , Midura-Kiela Monica T. , Lipko Maciej A. , Thurston Robert D. , Kiela Pawel R. , Ghishan Fayez K.
Published: May 2008

Na+/H+exchanger 3 (NHE3) provides a major route for intestinal Na+absorption. NHE3 has been considered a target of proinflammatory cytokines and enteropathogenic bacteria, and impaired NHE3 expression and/or activity may be responsible for inflammation-associated diarrhea. However, the possibility of loss of NHE3 function reciprocally affecting gut immune homeostasis has not been investigated. In this report, we describe that NHE3-deficient mice spontaneously develop colitis restricted to distal colonic mucosa. NHE3−/−mice housed in a conventional facility exhibited phenotypic features such as mild diarrhea, occasional rectal prolapse, and reduced body weight. Genomewide microarray analysis identified not only a large group of transport genes that potentially represent an adaptive response, but also a considerable number of genes consistent with an inflammatory response. Histological examination demonstrated changes in the distal colon consistent with active inflammation, including crypt hyperplasia with an increased number of 5-bromo-2′-deoxyuridine-positive cells, diffuse neutrophilic infiltrate with concomitant 15-fold increase in matrix metalloproteinase 8 expression, an increased number of pSer276-RelA-positive cells, and a significant decrease in periodic acid-Schiff-positive goblet cells. Real-time PCR demonstrated elevated expression of inducible nitric oxide synthase (38-fold), TNF-α (6-fold), macrophage inflammatory protein-2 (48-fold), and IL-18 (3-fold) in the distal colon of NHE3−/−mice. NHE3−/−mice showed enhanced bacterial adhesion and translocation in the distal colon. Colitis was ameliorated by oral administration of broad-spectrum antibiotics. In conclusion, NHE3 deficiency leads to an exacerbated innate immune response, an observation suggesting a potentially novel role of NHE3 as a modifier gene, which when downregulated during infectious or chronic colitis may modulate the extent and severity of colonic inflammation.
Upregulation of GRAIL is associated with remission of ulcerative colitis
Authors: Egawa Satoshi , Iijima Hideki , Shinzaki Shinichiro , Nakajima Sachiko , Wang Jun , Kondo Jumpei , Ishii Shuji , Yoshio Toshiyuki , Irie Takanobu , Nishida Tsutomu , Kakiuchi Yoshimi , Yasumaru Masakazu , Yoshihara Harumasa , Kanto Tatsuya , Tsujii Masahiko , Tsuji Shingo , Hayashi Norio
Published: May 2008

Abrogating tolerance against unidentified antigens is a critical step in the pathogenesis of ulcerative colitis (UC). T cell anergy, one of the main mechanisms of tolerance, has been shown to be induced by E3 ubiquitin ligases, such as gene related to anergy in lymphocytes (GRAIL), Itch, and c-Cbl in mice. However, it is not well known whether these E3 ligases play roles in human diseases. The pathophysiological role of the E3 ligases in patients with UC was investigated. At first, the expression of GRAIL, Itch, and c-Cbl in human anergic T cells was analyzed by quantitative RT-PCR and Western immunoblotting. Next, the mRNA expression of the E3 ligases was analyzed in peripheral CD4+T cells of 20 patients with UC and 10 healthy volunteers (HV). mRNA expression was analyzed in patients with active UC before and after treatment with prednisolone and leukocytapheresis. Anergic human CD4+T cells expressed significantly higher levels of GRAIL, Itch, and c-Cbl than nonanergic cells. GRAIL expression was significantly higher in patients with UC in remission than in patients with active disease and in HV ( P < 0.01). The level of GRAIL expression was also significantly increased in patients with active disease whose clinical activity index scores improved after treatment ( P < 0.05). There were no significant differences in Itch and c-Cbl expression among patients with active UC, patients with UC in remission, and HV. These data suggest that GRAIL plays an important role in maintaining remission in patients with UC.
Effects of leptin deficiency on postnatal lung development in mice
Authors: Huang Kewu , Rabold Richard , Abston Eric , Schofield Brian , Misra Vikas , Galdzicka Ewa , Lee Hannah , Biswal Shyam , Mitzner Wayne , Tankersley Clarke G.
Published: May 2008

Leptin modulates energy metabolism and lung development. We hypothesize that the effects of leptin on postnatal lung development are volume dependent from 2 to 10 wk of age and are independent of hypometabolism associated with leptin deficiency. To test the hypotheses, effects of leptin deficiency on lung maturation were characterized in age groups of C57BL/6J mice with varying Lep ob genotypes. Quasi-static pressure-volume curves and respiratory impedance measurements were performed to profile differences in respiratory system mechanics. Morphometric analysis was conducted to estimate alveolar size and number. Oxygen consumption was measured to assess metabolic rate. Lung volume at 40-cmH2O airway pressure (V40) increased with age in each genotypic group, and V40 was significantly ( P < 0.05) lower in leptin-deficient ( ob/ ob) mice beginning at 2 wk. Differences were amplified through 7 wk of age relative to wild-type (+/+) mice. Morphometric analysis showed that alveolar surface area was lower in ob/ ob compared with +/+ and heterozygote ( ob/+) mice beginning at 2 wk. Unlike the other genotypic groups, alveolar size did not increase with age in ob/ ob mice. In another experiment, ob/ ob at 4 wk received leptin replacement (5 μg·g−1·day−1) for 8 days, and expression levels of the Col1a1, Col3a1, Col6a3, Mmp2, Tieg1, and Stat1 genes were significantly increased concomitantly with elevated V40. Leptin-induced increases in V40 corresponded with enlarged alveolar size and surface area. Gene expression suggested a remodeling event of lung parenchyma after exogenous leptin replacement. These data support the hypothesis that leptin is critical to postnatal lung remodeling, particularly related to increased V40 and enlarged alveolar surface area.
Cardiac changes induced by immersion and breath-hold diving in humans
Authors: Marabotti Claudio , Scalzini Alessandro , Cialoni Danilo , Passera Mirko , L'Abbate Antonio , Bedini Remo
Published: May 2008

To evaluate the separate cardiovascular response to body immersion and increased environmental pressure during diving, 12 healthy male subjects (mean age 35.2 ± 6.5 yr) underwent two-dimensional Doppler echocardiography in five different conditions: out of water (basal); head-out immersion while breathing ( condition A); fully immersed at the surface while breathing ( condition B) and breath holding ( condition C); and breath-hold diving at 5-m depth ( condition D). Heart rate, left ventricular volumes, stroke volume, and cardiac output were obtained by underwater echocardiography. Early (E) and late (A) transmitral flow velocities, their ratio (E/A), and deceleration time of E (DTE) were also obtained from pulsed-wave Doppler, as left ventricular diastolic function indexes. The experimental protocol induced significant reductions in left ventricular volumes, left ventricular stroke volume ( P < 0.05), cardiac output ( P < 0.001), and heart rate ( P < 0.05). A significant increase in E peak ( P < 0.01) and E/A ( P < 0.01) and a significant reduction of DTE ( P < 0.01) were also observed. Changes occurring during diving ( condition D) accounted for most of the changes observed in the experimental series. In particular, cardiac output at condition D was significantly lower compared with each of the other experimental conditions, E/A was significantly higher during condition D than in conditions A and C. Finally, DTE was significantly shorter at condition D than in basal and condition C. This study confirms a reduction of cardiac output in diving humans. Since most of the changes were observed during diving, the increased environmental pressure seems responsible for this hemodynamic rearrangement. Left ventricular diastolic function changes suggest a constrictive effect on the heart, possibly accounting for cardiac output reduction.
Technique for quantitative RT-PCR analysis directly from single muscle fibers
Authors: Wacker Michael J. , Tehel Michelle M. , Gallagher Philip M.
Published: May 2008

The use of single-cell quantitative RT-PCR has greatly aided the study of gene expression in fields such as muscle physiology. For this study, we hypothesized that single muscle fibers from a biopsy can be placed directly into the reverse transcription buffer and that gene expression data can be obtained without having to first extract the RNA. To test this hypothesis, biopsies were taken from the vastus lateralis of five male subjects. Single muscle fibers were isolated and underwent RNA isolation ( technique 1) or placed directly into reverse transcription buffer ( technique 2). After cDNA conversion, individual fiber cDNA was pooled and quantitative PCR was performed using primer-probes for β2-microglobulin, glyceraldehyde-3-phosphate dehydrogenase, insulin-like growth factor I receptor, and glucose transporter subtype 4. The no RNA extraction method provided similar quantitative PCR data as that of the RNA extraction method. A third technique was also tested in which we used one-quarter of an individual fiber's cDNA for PCR (not pooled) and the average coefficient of variation between fibers was <8% (cycle threshold value) for all genes studied. The no RNA extraction technique was tested on isolated muscle fibers using a gene known to increase after exercise (pyruvate dehydrogenase kinase 4). We observed a 13.9-fold change in expression after resistance exercise, which is consistent with what has been previously observed. These results demonstrate a successful method for gene expression analysis directly from single muscle fibers.
Protein-containing nutrient supplementation following strength training enhances the effect on muscle mass, strength, and bone formation in postmenopausal women
Authors: Holm Lars , Olesen Jens L. , Matsumoto Keitaro , Doi Tatsuya , Mizuno Masao , Alsted Thomas J. , Mackey Abigail L. , Schwarz Peter , Kjær Michael
Published: May 2008

We evaluated the response of various muscle and bone adaptation parameters with 24 wk of strength training in healthy, early postmenopausal women when a nutrient supplement (protein, carbohydrate, calcium, and vitamin D) or a placebo supplement (a minimum of energy) was ingested immediately following each training session. At inclusion, each woman was randomly and double-blindedly assigned to a nutrient group or a placebo (control) group. Muscle hypertrophy was evaluated from biopsies, MRI, and dual-energy X-ray absorptiometry (DEXA) scans, and muscle strength was determined in a dynamometer. Bone mineral density (BMD) was measured using DEXA scans, and bone turnover was determined from serum osteocalcin and collagen type I cross-linked carboxyl terminal peptide. The nutrient group improved concentric and isokinetic (60°/s) muscle strength from 6 to 24 wk by 9 ± 3% ( P < 0.01), whereas controls showed no change (1 ± 2%, P > 0.05). Only the nutrient group improved lean body mass ( P < 0.05) over the 24 wk. BMD responded similarly at the lumbar spine but changed differently in the two groups at the femoral neck ( P < 0.05) [control: 0.943 ± 0.028 to 0.930 ± 0.024 g/mm3 (−1.0 ± 1.4%); nutrient group: 0.953 ± 0.051 to 0.978 ± 0.043 g/mm3 (3.8 ± 3.4%)] when adjusted for age, body mass index, and BMD at inclusion. Bone formation displayed an interaction ( P < 0.05), mainly caused by increased osteocalcin at 24 wk in the nutrient group. In conclusion, we report that nutrient supplementation results in superior improvements in muscle mass, muscle strength, femoral neck BMD, and bone formation during 24 wk of strength training. The observed differences following such a short intervention emphasize the significance of postexercise nutrient supply on musculoskeletal maintenance.
High rates of muscle glycogen resynthesis after exhaustive exercise when carbohydrate is coingested with caffeine
Authors: Pedersen David J. , Lessard Sarah J. , Coffey Vernon G. , Churchley Emmanuel G. , Wootton Andrew M. , Ng They , Watt Matthew J. , Hawley John A.
Published: May 2008

We determined the effect of coingestion of caffeine (Caff) with carbohydrate (CHO) on rates of muscle glycogen resynthesis during recovery from exhaustive exercise in seven trained subjects who completed two experimental trials in a randomized, double-blind crossover design. The evening before an experiment subjects performed intermittent exhaustive cycling and then consumed a low-CHO meal. The next morning subjects rode until volitional fatigue. On completion of this ride subjects consumed either CHO [4 g/kg body mass (BM)] or the same amount of CHO + Caff (8 mg/kg BM) during 4 h of passive recovery. Muscle biopsies and blood samples were taken at regular intervals throughout recovery. Muscle glycogen levels were similar at exhaustion [∼75 mmol/kg dry wt (dw)] and increased by a similar amount (∼80%) after 1 h of recovery (133 ± 37.8 vs. 149 ± 48 mmol/kg dw for CHO and Caff, respectively). After 4 h of recovery Caff resulted in higher glycogen accumulation (313 ± 69 vs. 234 ± 50 mmol/kg dw, P < 0.001). Accordingly, the overall rate of resynthesis for the 4-h recovery period was 66% higher in Caff compared with CHO (57.7 ± 18.5 vs. 38.0 ± 7.7 mmol·kg dw−1·h−1, P < 0.05). After 1 h of recovery plasma Caff levels had increased to 31 ± 11 μM ( P < 0.001) and at the end of the recovery reached 77 ± 11 μM ( P < 0.001) with Caff. Phosphorylation of CaMKThr286was similar after exercise and after 1 h of recovery, but after 4 h CaMKThr286phosphorylation was higher in Caff than CHO ( P < 0.05). Phosphorylation of AMP-activated protein kinase (AMPK)Thr172and AktSer473was similar for both treatments at all time points. We provide the first evidence that in trained subjects coingestion of large amounts of Caff (8 mg/kg BM) with CHO has an additive effect on rates of postexercise muscle glycogen accumulation compared with consumption of CHO alone.
Chronic Inflammation and CD16+ Natural Killer Cell Zeta-Chain Downregulation in Hemodialysis Patients
Authors: Eleftheriadis Theodoros , Kartsios Charalambos , Yiannaki Efi , Kazila Polizo , Antoniadi Georgia , Liakopoulos Vassilios , Markala Dimitra
Published: May 2008

Background: Natural killer (NK) cell activity is decreased in hemodialysis (HD) patients. Zeta-chain phosphorylation is an early event that follows the triggering of some NK cell-activating receptors. NK cell zeta-chain is downregulated in patients with cancer due to chronic inflammation. HD is also a chronic inflammatory state. NK cell zeta-chain expression in HD was evaluated. Patients and Methods: Thirty-three HD patients and 30 healthy volunteers were enrolled into the study. The CD3–CD16+ subpopulation was examined, since it corresponds to 90% of all NK cells and has the highest cytotoxicity.NK cell count and zeta-chain mean fluorescence intensity were evaluated with flow cytometry. The inflammatory markers C-reactive protein, IL-6 and tumor necrosis factor-α were measured with ELISA. Results: The inflammatory markers were increased in HD patients. NK cell count did not differ between HD patients and healthy volunteers. NK cell zeta-chain mean fluorescence intensity was decreased in the patient group. Conclusions: Chronic inflammation could be responsible for the NK cell zeta- chain downregulation in HD patients, contributing to the decreased NK cell activity.
An Animal Model of Ischemic Facial Palsy
Authors: Takeda Setsuko , Takeda Taizo , Okada Teruhiko , Nakatani Hiroaki , Hamada Masashi , Kakigi Akinobu
Published: May 2008

We investigated facial palsy which was induced by the interruption of the petrosal artery in guinea pigs. Forty animals were observed for 2 months regarding their behavioral facial nerve function and assessed by the blink reflex. Morphological changes in the intratemporal portion were observed with transmission electron microscopy in 20 animals with an interrupted petrosal artery. Facial palsy developed in 85.0% within 3 days after the interruption. The degree of palsy varied from mild to severe. Remission of palsy required 2–3 months in severe cases, 3 weeks or less in mild/moderate cases. Histological studies revealed a striking difference in the degree of degenerative changes between severe cases and mild/moderate cases. Animals with severe palsy showed extensive axonal atrophy and myelin disruption from the early stage. Meanwhile, degenerative changes were slight in cases with mild/moderate palsy. Regenerating unmyelinated fibers appeared 1 week after the interruption, but diminished in number 4 weeks later. Thereafter, new myelin was reformed on fibers. In cases of severe nerve damage, however, this regeneration process did not always seem to work well. A decrease in number and an irregular shape of the fibers were noted in animals with incomplete recovery. This animal model may be helpful for understanding the pathophysiology of ischemic facial palsy.
Proximal Esophageal Stenosis in Head and Neck Cancer Patients after Total Laryngectomy and Radiation
Authors: Vu Kim N. , Day Terry A. , Gillespie M. Boyd , Martin-Harris Bonnie , Sinha Debajyoti , Stuart Robert K. , Sharma Anand K.
Published: May 2008

Background: There has been an increasing focus on late functional effects of head and neck cancer (HNC) treatment. This study was undertaken to evaluate the incidence of late proximal esophageal stricture in patients undergoing total laryngectomy (TL) and radiation therapy (RT). Material and Methods: An institutional retrospective review of HNC patients treated between 1995 and 2003 with TL and RT was undertaken. Thirty-three patients with stage II–IV disease were included; 25 patients had TL and postoperative RT (group 1), while 8 patients had definitive RT with salvage laryngectomy (group 2). Results: The median follow-up was 28 months. At the last follow-up, 25 patients (76%) were alive and disease free. Four had died and 3 developed distant metastasis. Dysphagia or stenosis developed in 40% in group 1 and 75% in group 2 patients. The median time to dysphagia was 5.5 months for all patients. Conclusions: The incidence of esophageal stenosis was 33% for all patients. Contributing factors for esophageal stenosis after TL and RT include continued alcohol and tobacco use, the dose-volume relationship of the RT and normal tissue damage from the tumor and the treatment.
Expression of Cytosolic Phospholipase A2 and Cyclooxygenase 2 and Their Significance in Human Oral Mucosae, Dysplasias and Squamous Cell Carcinomas
Authors: Zhang Shuangyue , Du Yifei , Tao Jiangfeng , Wu Yunong , Chen Ning
Published: May 2008

Prostaglandin E2 (PGE2) plays an important role in promoting carcinogenesis. Cytosolic phospholipase A2 (cPLA2) and cyclooxygenase 2 (COX-2) are both key enzymes for PGE2 biosynthesis. Recent evidence suggests that the coordinated function of cPLA2 and COX-2 in the arachidonic acid pathway may contribute to the process of carcinogenesis in various tissue types. However, the concomitant effect of these enzymes on oral carcinogenesis remains unclear. In this study,we evaluated the expression of cPLA2 and COX-2 in normal oral mucosa, dysplastic oral mucosa and squamous carcinoma (SCC) using immunohistochemistry. In an in vitro assay, Tca8113 and KB oral cancer cells were treatedwith NS-398 (a selective inhibitor of COX-2) for varying time intervals: 6, 12, 24, 48 and 72 h. The levels of cPLA2 and COX-2 expression were evaluated by Western blot, and PGE2 production was analyzed by radioimmunoassay. We found that cPLA2 and COX-2 were expressed at higher levels in oral dysplasia and SCC than in normal oral mucosa. cPLA2 expression was also found to correlate closely with COX-2 expression. Moreover, the enzymatic activities of cPLA2 and COX-2 were gradually downregulated with longer durations of treatment with NS-398, as demonstrated by a reduction in the amount of PGE2 production over time. Our data suggest that the coordinated activity of cPLA2 and COX-2 contribute to the process of oral carcinogenesis, thus identifying cPLA2 as a potential target for the prevention and treatment of oral cancers.
Twisted Ovarian Tumor Causing Progressive Hemothorax: A Case Report of Porous Diaphragm Syndrome
Authors: Saito F. , Tashiro H. , Honda R. , Ohtake H. , Katabuchi H.
Published: May 2008

Background: Porous diaphragm syndrome is caused by a defect in the diaphragm. The defect may induce pleural effusion in a patient with an ovarian tumor. Case Report: A 59-year-old Japanese woman with an ovarian tumor and right hemothorax underwent thoracotomy and presented with a fenestra in the right diaphragm through which bloody fluids were flowing from the peritoneal cavity into the pleural space. Following suturing of the fenestra, laparotomy revealed intraabdominal bleeding due to torsion of an ovarian tumor. Conclusion: This is the first report in which the diaphragmatic defect was identified in a patient with an ovarian tumor and hemothorax. Porous diaphragm syndrome may be involved in the pathophysiology of right pleural effusion observed in other medical conditions such as Meigs’ syndrome, ovarian hyperstimulated syndrome, and ovarian cancer.
Selective elimination of chromosomally unbalanced zygotes at the two-cell stage in the Chinese hamster
Authors: Sonta S. , Fukui K. , Yamamura H.
Published: May 2008

The gametic and zygotic selection of genome imbalance was investigated in the Chinese hamster by direct chromosome analyses of spermatocytes and preimplantation embryos from crosses between chromosomally normal females and males heterozygous for a reciprocal translocation, T(2;10)3Idr, abbreviated here as T3. The karyotypes and the frequencies of embryos observed at the first cleavage in the cross + / + ♀ × T3/ + ♂ were consistent with those expected from Mil scoring in male T3 heterozygotes. Therefore, it was concluded that there was neither gametic selection against genome imbalance nor zygotic selection from fertilization until the first cleavage metaphase. However, 9.1–10.8% of embryos were arrested at the two-cell stage, and karyotypes of these embryos were confirmed as 22(2,10,10,102), 21(2,10,10), and 21(2,10,102). The common abnormality of these embryos was partial monosomy of chromosome 2. Among day 4 embryos, some chromosomally unbalanced embryos, mainly with a deficiency of other segments of chromosomes 2 and 10, had fewer blastomeres than chromosomally balanced embryos. This finding suggests that cleavage of these embryos had been retarded by day 4 of gestation.
Pachytene analysis of a man with a 13q;14q translocation and infertility
Authors: Luciani J.M. , Guichaoua M.R. , Mattei A. , Morazzani M.R.
Published: May 2008

Pachytene analysis was undertaken in a sterile 13q;14q heterozygous translocation carrier in an attempt to follow the segregational behavior of the trivalent and to evaluate the relationship of Robertsonian translocations in man to the impairment of spermatogenesis. Well-spread bivalents from pachytene nuclei were identified by their chromomere patterns. The trivalent was found always in cis configuration. Silver staining demonstrated the loss of nucleolar organizer regions from the translocated chromosomes. A nonrandom association was found between the trivalent configuration and the sex vesicle in 61% of the pachytene nuclei examined. Such an association has been described before in mice heterozygous for Robertsonian or reciprocal translocations, and may thus represent a general phenomenon. As in mice, this contact was restricted to the centromeric region of the trivalent. A hypothesis relating the association of the trivalent with the sex vesicle to impairment of normal X-chromosome inactivation and subsequent spermatogenic breakdown is discussed. Other chromosomal abnormalities in which sex-vesicle anomalies are associated with male sterility (such as X-or Y-autosomal translocations) are also considered. It is proposed that any process interfering with normal X-chromosome inactivation in pachytene spermatocytes could disturb subsequent meiotic or postmeiotic germ-cell development.
Induction of sister chromatid exchange by 3-aminobenzamide is independent of bromodeoxyuridine
Authors: Morgan W.F. , Wolff S.
Published: May 2008

The poly(ADP-ribose) polymerase inhibitor, 3-aminobenzamide (3AB), significantly increases sister chromatid exchange (SCE) frequency without causing apparent damage to cellular DNA. A previous study has suggested that the increase of SCEs by 3AB results from DNA replication on a template strand containing bromodeoxyuridine (BrdU), which is used to visualize SCEs. Therefore, to study the importance of BrdU incorporation on the induction of SCEs by 3AB, we analyzed exchanges induced during the first round of replication (twin SCEs) and those induced during the second (single SCEs). 3AB increased the formation of SCEs in both replication cycles, but significantly more exchanges were induced in the second cycle, when BrdU was present in the template DNA. These data are consistent with the suggestion that the presence of BrdU in the template strand of DNA plays an important role in SCE induction by 3AB. However, we also studied 3AB-induced SCEs by autoradiography of cells cultured with 3H-thymidine (3H-dT) instead of BrdU. A significant increase in SCE frequency was also observed in cells from these cultures. Furthermore, the analysis of twin and single SCEs showed that with 3H-dT too, there was a greater increase in SCEs in the second cycle than in the first. Thus, SCE induction by 3AB in the second cycle is not dependent on the presence of BrdU in template DNA. Incubation of cells with deoxycytidine was found to have no effect on the frequency of SCEs induced by 3AB, suggesting that an imbalance in the deoxycytidine precursor pool did not account for the effect.
Unusual C-band patterns in three karyotypically rearranged forms of Scapteromys (Rodentia, Cricetidae) from Brazil
Authors: Freitas T.R.O. , Mattevi M.S. , Oliveira L.F.B.
Published: May 2008

Chromosome studies of 30 specimens of the rodent Scapteromys collected at nine localities in southern Brazil revealed the occurrence of three karyotypic taxa with 2n = 36 (one locality), 34 (two localities), and 24 (six localities), although all three had 40 autosomal arms (AN). The G-band analysis indicated that this reduction in diploid number was mainly due to Robertsonian translocations which have occurred along a gradient, possibly in two independent evolutive routes. The C-bands occur on one autosomal pair and on the X and Y in the 2n = 36 and 34 forms and on the X and Y chromosomes only in the 2n = 24 taxon. The broad genomic reorganization which has occurred in this genus, in which the chromosomes do not have large amounts of constitutive heterochromatin, argues against the idea that a large amount of constitutive heterochromatin favors chromosome evolution and speciation.
An X1X1X2X2/X1X2Y mechanism of sex determination in a South American rodent, Deltamys kempi (Rodentia, Cricetidae)
Authors: Sbalqueiro I.J. , Mattevi M.S. , Oliveira L.F.B.
Published: May 2008

Chromosome studies on 14 specimens of Deltamys kempi disclosed six males with 2n = 37, NF = 38, six females with 2n = 38, NF = 38, and two females with 2n = 37, NF = 38. G- and C-band analyses revealed a Y-autosome translocation in the males leading to a multiple chromosome system of sex determination of the type X1X1X2X2/X1X2Ythis being the second case of such a mechanism described in rodents. At meiosis the males presented a trivalent in which C-banding studies showed an alternate orientation of the sex chromosomes due to end-to-end association of the X1and Y chromosomes, the Y and the X2 being held together by interstitial chiasmata. At metaphase II both n=17 + Y and n=18+X1 are regularly observed. The two females with 2n = 37, NF = 38, are heterozygous for an autosomal centric fusion involving chromosomes 1 and 13. The product of the Y-autosome translocation constitutes the largest element of the karyotype (9.4% of the haploid set); the X1 chromosome amounts to 7.8% of this set, including a large heterochromatic block. When only its euchromatic region is considered, this percentage decreases to 4.6%. From two to seven NORs were observed at the telomeres, with a mean of 4.4+ 1.1 per cell.
X chromosome inactivation in bone marrow cells of adult mice carrying Searle’s X-autosome translocation: occurrence of the early-replicating inactive X chromosome
Authors: Takagi N. , Endo S. , Sugawara O.
Published: May 2008

Using BrdU labelling-acridine orange fluorescence staining and the expression of PGK-1 isozymes, we attempted to clarify the pattern of X chromosome inactivation in bone marrow cells from adult female mice heterozygous for Searle’s X-autosome translocation. The asynchronously replicating X chromosome was always the morphologically normal one, and neither of the translocated X chromosomes showed allocyclic behavior. Unexpectedly, a substantial proportion of the allocyclic X chromosome apparently finished replication earlier than any other chromosomes of the cell. This early replicating allocyclic X chromosomes was judged to be as genetically inactive as the late replicating one, since the Pgk-1b allele on the normal X was never expressed in bone marrow cells. Study of karyotypically normal females and females carrying Cattanach’s insertion showed that the early replicating X chromosome is not just a feature of the Searle’s translocation in the adult bone marrow cells and may be either paternal or maternal in origin. This type of allocyclic X chromosome deserves attention in assessing X chromosome inactivation in female somatic cells.
NRAS transforming gene maps to region p11→p13 on chromosome 1 by in situ hybridization
Authors: Rabin M. , Watson M. , Barker P.E. , Ryan J. , Breg W.R. , Ruddle F.H.
Published: May 2008

The human transforming gene NRAS, cloned from SK-N-SH neuroblastoma cells, has been mapped to region p11→p13 on chromosome 1 by in situ hybridization.
Localization of the cellular oncogenes ABL, SIS, and FES on human germ-line chromosomes
Authors: Jhanwar S.C. , Neel B.G. , Hayward W.S. , Chaganti R.S.K.
Published: May 2008

The human germ-line positions of the oncogenes ABL, SIS, and FES, the cellular counterparts of the v-onc genes of Abelson murine leukemia virus, simian sarcoma virus, and feline sarcoma virus, respectively, have been determined by in situ molecular hybridization of 3H-labeled v-onc gene probes to meiotic pachytene chromosomes. The position of ABL at 9q34.1 corresponds to the breakpoint in chromosome 9 in the translocation that gives rise to the Philadelphia chromosome, t(9; 22) (q34; q11); the position of SIS at 22ql3.1 is distal to the breakpoint in this chromosome. FES at 15q26.1 is also distal to the breakpoint in chromosome 15 in the translocation commonly seen in acute promyelocytic leukemia, t(15;17) (q24;q22).
Localization of the human glucagon gene (GCG) to chromosome segment 2q36→37
Authors: Schroeder W.T. , Lopez L.C. , Harper M.E. , Saunders G.F.
Published: May 2008

Hybridization of a 3H-labeled bovine glucagon cDNA plasmid to human metaphase chromosomes revealed significant labeling of the distal portion of the long arm of chromosome 2. A large portion (37%) of the cells analyzed exhibited labeling of the 2. A significant percentage (40%) of the labeled sites on the 2 were in segment 2q36→37. Therefore, the human glucagon gene (GCG), was assigned to this segment. Localization of the glucagon gene, whose chromosomal assignment was previously not known, demonstrates the general applicability of in situ hybridization as a powerful gene mapping technique.
Cytogenetic analysis of retinoblastoma: evidence for multifocal origin and in vivo gene amplification
Authors: Chaum E. , Ellsworth R.M. , Abramson D.H. , Haik B.G. , Kitchin F.D. , Chaganti R.S.K.
Published: May 2008

Retinoblastoma (Rb) is an uncommon childhood tumor of the neural retina with a significant genetic component in its etiology. A small proportion of patients have a deletion in chromosome 13 encompassing band 13q14, an observation which permitted the assignment of the RBI locus to this region. About 20% of Rb tumors exhibit microscopic deletions of band 13q14 or monosomy 13. Trisomy 1q and i(6p) have also been reported in a high percentage of tumors. We analyzed the chromosome complements from direct preparations of 10 Rb tumors derived from seven patients. Modal chromosome numbers ranged from 45 to 48, and occasional duplications of the genomes were noted. In general, the tumors were chromosomally stable, although karyotypic evolution and random chromosome loss were encountered. Consistent abnormalities included trisomy 1q, i(6p), 6q-, and del(13)(q12→14). One patient with bilateral Rb had three tumor clones (two in one eye and one in the other) with chromosome abnormalities unrelated in origin. A second patient with unilateral Rb had two tumor clones with chromosome abnormalities again unrelated in origin. These two patients provide some of the first cytogenetic evidence for the multifocal origin of primary Rb. In the untreated tumor of a third patient, a homogeneously staining region (HSR) was detected in 1p32, indicating gene amplication in vivo; previously, an HSR at this site has been reported in the established Rb cell line Y79.
Evidence for heterosynaptic pairing of the inverted segment in pericentric inversion heterozygotes of the deer mouse (Peromyscus maniculatus)
Authors: Greenbaum I.F. , Reed M.J.
Published: May 2008

Silver-stained pachytene cells of male deer mice, Peromyscus maniculatus, which were heterozygous for a naturally occurring pericentric inversion of chromosome 6, were analyzed by light microscopy. The presence of the terminally positioned inversion, involving approximately 30% of the length of chromosome 6, was detected by G-banding. Within the inversion, C-band-positive heterochromatin was restricted to the centromeric region. Silver-staining of spermatocytes revealed the synaptonemal complexes (SCs) of the autosomal bivalents and the X-Y chromosome association. Pachytene cells were scored for the presence of inversion loops corresponding to the pericentric inversion of chromosome 6. Possible loop 6 configurations were detected in less than 1% of the cells examined, the vast majority of cells having regularly formed autosomal SCs similar to those reported for homomorphic chromosome pairs in other rodent species. It appears, therefore, that in these mice the inverted region of chromosome 6 was heterosynaptic throughout pachytene. Heterosynapsis is hypothesized as a mechanism which might obviate the production of duplication and deletion chromatids expected from crossing-over in pericentric inversion loops. The observation of heterosynaptic pairing in the inverted segment and the hypothesis of inversion heterosynapsis as a mechanism averting gametic loss are consistent with the widespread occurrence of pericentric inversion polymorphisms in P maniculatus and the apparent failure of pericentric inversions to genetically isolate populations of this species.
In situ hybridization and translocation breakpoint mapping
Authors: Emanuel B.S. , Selden J.R. , Wang E. , Nowell P.C. , Croce C.M.
Published: May 2008

In situ chromosomal hybridization of a probe for part of the lamda light chain constant region (Cλ) has demonstrated that the 22q11 breakpoints of chronic myelogenous leukemia (CML) t(9;22) and Burkitt lymphoma t(8;22) are not identical. For CML, the breakpoint is distal to the IGLC genes, whereas for Burkitt lymphoma it is proximal. The study provides direct evidence for regional assignment of the IGLC gene cluster to 22q11.
Expression and regional assignment of Chinese hamster ESD and rRNA genes associated with translocations giving rise to chromosomes Z1 and Z6 in CHO cells
Authors: Stallings R.L. , Adair G.M. , Lin J.C. , Siciliano M.J.
Published: May 2008

The Chinese hamster genes ADK, NP, ESD, PGM2, PEPS, PEPB, GLO, and GSR, all of which are on Chinese hamster chromosome 1, were assigned to CHO-LA chromosomes by analysis of the segregation of CHO isozymes and chromosomes from interspecific somatic cell hybrids made with CHO cells and mouse C11D cells. One allele of each of these eight loci remained linked on the normal chromosome 1 homolog. For seven loci, the other allele remained linked on chromosome Zl, but ESD was shown to have been translocated to chromosome Z6 (Chinese hamster chromosome 5q+). Ag-NOR staining of CHO chromosomes indicated that the (1; 5) translocation was very likely reciprocal, since the Chinese hamster chromosome 5, which gave rise to the CHO Z6, lacks an NOR and the Zl now has one. These data allowed regional assignment of ESD to the distal portion of Chinese hamster chromosome 1p and provided genetic evidence for the origin of CHO chromosomes Z1and Z6 from Chinese hamster chromosomes 1 and 5. Induced electrophoretic shift mutations of ESD and positive Ag-NOR staining for the rRNA genes on the Z1 showed that the activities of the genes lying close to the translocation breakpoints were maintained.
A 39,X/40,XY/41,XYY mosaic male mouse
Authors: Das RK. , Behera AK.
Published: May 2008

Cytogenetic analyses of bone marrow and gonadal cells in a male mouse, which appeared to be normal, revealed mosaicism in both tissues. Three chromosome complements, 39, X, 40, XY, and 41, XYY, were found in both bone marrow and spermatogonia, while only the last two complements were found in spermatocytes. In this mouse, unlike in the human, the XYY cells showed a proliferative advantage over the XY cells. In XYY cells at diakinesis/metaphase I the gonosomes showed all possible types of association, and a pairing advantage of the X chromosome was clearly demonstrated. The fertility of the mouse was not determined. However, since the epididymal sperm count was reduced by only 55% and the incidence of sperm head abnormality was near normal, it is not evident that the mouse was sterile.
Gene mapping in the rat by mouse-rat somatic cell hybridization: synteny of the albumin and α-fetoprotein genes and assignment to chromosome 14
Authors: Szpirer J. , Levan G. , Thorn M. , Szpirer C.
Published: May 2008

The methods of somatic cell genetics and molecular hybridization were applied to a panel of mouse × rat hepatocyte hybrids segregating rat chromosomes to assign the rat genes coding for two serum proteins, albumin and α-fetoprotein (Alb and Afp). The molecular hybridization of DNAs from different hybrids with cloned DNA probes showed that all the hybrid clones possessing the rat Alb gene and expressing it also retained the rat Afp locus, which is not expressed in these hybrids. So the Alb and Afp genes are syntenic in the rat, as in the mouse. Furthermore, the cytogenetic analysis allowed the assignment of these two loci to rat chromosome 14.
Assignment of the gene for human arylsulfatase B, ARSB, to chromosome region 5p11→5qter
Authors: Fidzianska E. , Abramowicz T. , Czartoryska B. , Glogowska I. , Gorska D. , Rodo M.
Published: May 2008

The structural gene coding for human arylsulfatase B, ARSB, is assigned to 5p11→5qter by analysis of somatic cell hybrids isolated from two separate fusions of human fibroblasts carrying a translocation involving chromosome 5 with the Chinese hamster cell line a3.
Bleomycin-induced chromosome breakage in G2 lymphocytes of retinoblastoma patients
Authors: Chaum E. , Doucette L.A. , Ellsworth R.M. , Abramson D.H. , Haik B.G. , Kitchin F.D. , Chaganti R.S.K.
Published: May 2008

Retinoblastoma (Rb) cells may be more sensitive to X-irradiation than normal cells when assayed for clonogenic survival, suggesting that such sensitivity can be used as a trait for detecting RBI gene carriers. We studied induction of chromosome damage in lymphocytes from patients with Rb by the radiomimetic antineoplastic antibiotic, bleomycin (BL). Lymphocytes were treated in G2 for 4 h at four concentrations of the drug (0.0, 0.3, 0.9, and 2.7 µg/ml), and chromosome damage was evaluated. No difference in levels of spontaneous or induced damage was detected among hereditary Rb, non-hereditary Rb, and normal lymphocytes. The role of X-ray treatment in the induction of second tumors in Rb patients is discussed.
Analysis of three whole-arm translocations in a mouse sarcoma cell line
Authors: Ghosh S. , Chaudhuri A.
Published: May 2008

Three apparently whole-arm translocation chromosomes in the mouse sarcoma 180 ascites cell line have been studied by G- and C-banding and by Hoechst staining. All three chromosomes appear to have two centromeres. Both centromeres of one, which are very close together, are likely to be active and to produce parallel separation of the chromatids. The centromeres of the other two chromosomes are well separated. One of these two centromeres may be inactive either because the kinetochore organizer has been inactivated or because the kinetochore plate has been deleted, leaving the AT-rich centromeric constituative heterochromatin intact. The possibility that these whole arm translocations arose by telomeric fusion and the molecular basis of such fusions are discussed.
Ultrastructural organization of double minute chromosomes and HSR regions in human colon carcinoma cells
Authors: Rattner J.B. , Lin C.C.
Published: May 2008

The ultrastructural organization of double minute chromosomes (DMs) and marker chromosomes displaying homogeneously staining regions (HSRs) have been investigated in two cell lines, COLO-320 DM and COLO-320 HSR, derived from a human colon carcinoma. Double minute chromosomes in the COLO-320 DM cell line vary in number from several to several hundred and in diameter from 0.5 to 2 µm. These chromosomes lack kinetochore structures which appear as discrete electron dense plates on the centromeric chromosomes. The DMs are composed of regularly arranged nucleosome-containing fibers. These are folded to form 30 nm fibers which extend as loops from the central portion of the chromosome. In COLO-320 HSR, a majority of cells contain a single submetacentric HSR marker chromosome with HSR regions in both chromosome arms. The HSR chromosome appears structurally analogous in EM preparations to the other centromeric chromosomes of the karyotype.
A twin study of sister chromatid exchanges in human lymphocytes following carcinogen exposure and DNA repair incubation
Authors: Hedner K. , Iselius L. , Mitelman F. , Nordén Å. , Pero R.W.
Published: May 2008

Sister chromatid exchanges (SCEs) were analyzed in peripheral lymphocytes obtained from nine healthy monozygotic (MZ) and nine healthy dizygotic (DZ) pairs of male twins. In addition, increases in SCE rates following in vitro treatment of whole blood with 100 µM N-acetoxy-2-acethylaminofluorene (NA-AAF), and after an 18-h DNA repair incubation period, were analyzed in the same twins. There was no significant intrapair difference in the variance of SCE frequencies among MZ and DZ twins at the baseline level, after NA-AAF treatment, or after a DNA repair incubation period. It was concluded that genetic factors probably do not contribute significantly to the individual variation that has been observed in baseline or NA-AAF-induced SCE rates. Thus, any observed alterations in SCE frequencies are probably caused by environmental influences.
Distamycin A/DAPI bands and the effects of 5-azacytidine on the chromosomes of the chimpanzee, Pan troglodytes
Authors: Schmid M. , Haaf T.
Published: May 2008

The chromosomes of the chimpanzee were stained with distamycin A/DAPI, which labels specific C-bands. Bright distamycin A/DAPI fluorescence was found in the heterochromatic regions of chromosomes 6, 11, 14 to 16, 18 to 20, and 23 and the Y. Lymphocyte cultures from chimpanzees were treated with low doses of 5-azacytidine during the last hours of culture. This cytosine analog induces highly distinct undercondensations in 28 heterochromatic regions of 19 chromosomes. These 5-azacytidine-sensitive regions are predominantly located in the terminal C-bands of the chromosomes. In vitro treatment with 5-azacytidine also preserves into the metaphase stage somatic pairings between the 5-azacytidine-sensitive heterochromatic regions in interphase nuclei. The homologies and differences regarding the chromosomal localization of distamycin A/DAPI-bright C-bands, 5-azacytidine-sensitive heterochromatin, 5-methylcytosine-rich DNA sequences, and satellite DNAs in the chimpanzee and man are discussed.
Temporal changes in chromosome abnormality rate in human spontaneous abortions: evidence for an association between sex-chromosome monosomy and trisomy 16
Authors: Hassold T. , MacLean C.
Published: May 2008

As part of a cytogenetic survey of human spontaneous abortions, the relative frequencies of different categories of chromosome abnormalities were evaluated for possible temporal changes. Three classes of chromosome abnormalities showed significant linear trends; sex-chromosome monosomy and tetraploidy decreased over the study period, while trisomy increased. The increase in trisomy was largely attributable to trisomy 16, which showed a two-fold increase over the duration of the study. The linear increase in trisomy 16 was inversely related to sex-chromosome monosomy. This effect was restricted to women over 30 yr of age and was most pronounced among Oriental women.
Cytogenetics of Atlantic eels: C- and G-banding, nucleolus organizer regions, and DNA content
Authors: Sola L. , Camerini B. , Cataudella S.
Published: May 2008

C- and G-banding, silver staining, and cytofluorometric analysis of DNA content were carried out on two species of eels, Anguilla anguilla and A. rostrata, to compare them, to investigate the existence of sex chromosomes in both species, on which different authors disagree, and to understand the significance of the sex-independent variability found in one chromosome pair.
An in vitro and in vivo study of a BrdU-sensitive fragile site in the Chinese hamster
Authors: Lin M.S. , Takabayashi T. , Wilson M.G. , Marchese C.A.
Published: May 2008

The frequencies of chromosome aberrations and development of the bromodeoxyuridine (BrdU)-sensitive fragile site were studied in vitro in Chinese hamster kidney and bone marrow cells and in vivo in Chinese hamster bone marrow cells. Chromosome aberrations in these cell systems were measured in response to different concentrations of BrdU, fluorodeoxyuridine, or both. The fragile site was found in both homologues of chromosome 1 at 1q22. Treatment with BrdU in vitro but not in vivo produces significant chromosome aberrations. About 50% of chromosome aberrations found after treatment in vitro were at the BrdU-sensitive fragile site compared with 12.5% after treatment in vivo. These results show that BrdU is much more potent in vitro than in vivo in inducing both chromosome aberrations and the expression of the BrdU-sensitive site.
On the nature and extent of XY pairing at meiotic prophase in man
Authors: Chandley A.C. , Goetz P. , Hargreave T.B. , Joseph A.M. , Speed R.M.
Published: May 2008

Evidence is presented that pairing between the human X and Y chromosomes could be more extensive at early pachytene than has previously been supposed and could involve even the entire euchromatic portion of the Y chromosome. Following desynapsis over the major part of the X and Y axes, a small paired segment of Xp and Yp remains into late pachytene. Association between the distal tips of Xq and Yq can also be observed in about one half of the spermatocytes examined. A hypothesis linking meiotic pairing to early replicating sites along the chromosomes is proposed.