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Biomedical subjects

W Zhou

Publications and source records attributed to W Zhou.

At least 163 records · Page 9Linked to original sources

Hoxa5 gene regulation: A gradient of binding activity to a brachial spinal cord element.

The Hox genes cooperate in providing positional information needed for spatial and temporal patterning of the vertebrate body axis. However, the biological mechanisms behind spatial Hox expression are largely unknown. In transgenic mice, gene fusions between Hoxa5 (previously called Hox-1.3) 5' flanking regions and the lacZ reporter gene show tissue- and time-specific expression in the brachial spinal cord in day 11-13 embryos. A 604-bp regulatory region with enhancer properties directs this spatially specific expression. Fine-detail mapping of the enhancer has identified several elements involved in region-specific expression, including an element required for expression in the brachial spinal cord. Factors in embryonic day 12.5 nuclear extracts bind this element in electrophoretic mobility shift assays (EMSA) and protect three regions from DNase digestion. All three sites contain an AAATAA sequence and mutations at these sites reduce or abolish binding. Furthermore, this element binds specific individual embryonic proteins on a protein blot. The binding activity appears as a gradient along the anterior-posterior axis with two- to threefold higher levels observed in extracts from anterior regions than from posterior regions. In parallel with the EMSA, the proteins on the protein blot also show reduced binding to probes with mutations at the AAATAA sites. Most importantly, transgenic mice carrying Hoxa5/lacZ fusions with the three AAATAA sites mutated either do not express the transgene or have altered transgene expression. The brachial spinal cord element and its binding proteins are likely to be involved in spatial expression of Hoxa5 during development.

Animals↗

Contribution of renal secreted complement C3 to the circulating pool in humans.

Complement C3 produced within the kidney may be an important mediator of local inflammatory and immunological injury. The overall level of renal C3 production and consequently its contribution to the total circulating C3 level are, however, unknown. This was investigated by using the conversion of C3 from recipient to donor allotype following renal transplantation. The C3 F and S allotypes of 80 consecutive renal donor-recipient pairs (148 individuals) were determined by amplification refractory mutation system analysis. The extent of allotype conversion in C3 F/S mismatched recipients was quantified at different stages after transplantation, using an enzyme-linked immunosorbent assay specific for the HAV 4-1 polymorphism of C3 that is strongly associated with C3F. Twenty-one of the eighty recipients were potentially informative, i.e., were C3 SS recipients of C3 FF or FS donor kidneys. In the early postoperative period, donor-derived C3 (HAV 4-1-positive) was undetectable, increasing to 9.6% of the total circulating C3 at times of acute allograft rejection. When graft dysfunction occurred from causes other than rejection, donor C3 remained undetectable. After stable graft function was attained (3-13 mo after transplantation), donor C3 made up 4.5% of the total circulating C3 pool. Our findings demonstrate that human transplant kidney in the resting state is a significant source of extrahepatic C3. Its heightened local synthesis during rejection episodes suggests a possible pathogenic role for C3 in this immunological process.

Adolescent↗

Differential regulation of cellular target genes by p53 devoid of the PXXP motifs with impaired apoptotic activity.

Activation of the p53 tumor suppressor protein can lead to either cell cycle arrest or apoptosis. Several functional domains necessary for mediating cell cycle arrest and apoptosis in p53 have been mapped, e.g., the proline-rich domain. The proline-rich domain is located within residues 60-90, which comprise five PXXP motifs (where P represents proline and X any amino acid). To further delineate the function of the proline-rich domain and its potential role in transactivation, we generated several groups of cell lines that inducibly express various p53 mutants using a tetracycline-regulated expression system. We found that p53(delta62-91), which lacks all five PXXP motifs in human p53, is capable of inducing cell cycle arrest but not apoptosis, while p53(gln22-ser23/delta62-91), which contains a double point mutation in the activation domain as well as deletion of the proline-rich domain, completely loses its activity. However, p53(delta74-91), which contains only one PXXP motif at its N-terminus, is not only capable of inducing cell cycle arrest but also retains a partial apoptotic activity. Furthermore, we found that deletion of the proline-rich region has no or very mild effects on activation of several transiently transfected p53 target gene promoters, i.e., the p21, MDM2, BAX, and GADD45 promoters. However, such deletion differentially affects p53 induction of endogenous target genes, i.e., induction of p21, MDM2, BTG2, p85, PIG3, PIG6 and PIG11 was reduced or abrogated but induction of BAX, KILLER/DR5, PIG2, PIG7 and PIG8 was not substantially affected. Interestingly, induction of GADD45 was enhanced. These results suggest that the proline-rich region may play a role in chromatin remodeling, which counteracts chromatin-mediated repression for some of the endogenous p53 target genes.

Apoptosis↗

Microbial conversion of indene to indandiol: a key intermediate in the synthesis of CRIXIVAN.

Indene is oxidized to mixtures of cis- and trans-indandiols and related metabolites by Pseudomonas putida and Rhodococcus sp. isolates. Indene metabolism is consistent with monooxygenase and dioxygenase activity. P. putida resolves enantiomeric mixtures of cis-1,2-indandiol by further selective oxidation of the 1R, 2S-enantiomer yielding high enantiomeric purity of cis-(1S, 2R)-indandiol, a potential intermediate in the synthesis of indinavir sulfate (CRIXIVAN), a protease inhibitor used in the treatment of AIDS. Molecular cloning of P. putida toluene dioxygenase in Escherichia coli confirmed the requirement for the dihydrodiol dehydrogenase in resolving racemic mixtures of cis-indandiol. Rhodococcus sp. isolates convert indene to cis-(1S, 2R)-indandiol at high initial enantiomeric excess and one isolate also produces trans-(1R, 2R)-indandiol, suggesting the presence of monooxygenase activity. Scale up and optimization of the bioconversions to these key synthons for chiral synthesis of potential intermediates for commercial manufacture of indinavir sulfate are described.

Drug Design↗

Kainic acid (KA)-induced seizures in Sprague-Dawley rats and the effect of dietary taurine (TAU) supplementation or deficiency.

Male Sprague-Dawley rats received TAU supplementation (1.5% in drinking water) or TAU deficient diets for 4 weeks to test for a possible neuroprotective role of TAU in KA-induced (10 mg/kg s.c.) seizures. TAU supplementation significantly increased serum and hippocampal TAU levels, but not TAU content in temporal cortex or striatum. TAU deficient diets did not attenuate serum or tissue TAU levels. Dietary TAU supplementation failed to decrease the number or latency of partial or clonic-tonic seizures or wet dog shakes, whereas a TAU deficient diet decreased the number of clonictonic and partial seizures. This study does not support previous observations of an anticonvulsant effect of TAU against KA-induced seizures. KA-treatment decreased alpha 2-adrenergic receptor binding sites and TAU content in the temporal cortex across all dietary treatment groups, supporting previous evidence of severe KA-induced damage and neuronal loss in this brain region.

Amino Acids↗

Induced abortion and subsequent pregnancy duration.

OBJECTIVE: To examine whether induced abortion influences subsequent pregnancy duration. METHODS: Women who had their first pregnancies during 1980, 1981, and 1982 were identified in three Danish national registries. A total of 15,727 women whose pregnancies were terminated by first-trimester induced abortions were compared with 46,026 whose pregnancies were not terminated by induced abortions. All subsequent pregnancies until 1994 were identified by register linkage. RESULTS: Preterm and post-term singleton live births were more frequent in women with one, two, or more previous induced abortions. After adjusting for potential confounders and stratifying by gravidity, the odds ratios of preterm singleton live births in women with one, two, or more previous induced abortions were 1.89 (95% confidence interval [CI] 1.70, 2.11), 2.66 (95% CI 2.09, 3.37), and 2.03 (95% CI 1.29, 3.19), respectively. Odds ratios of post-term singleton live births in women with one, two, or more previous induced abortions were 1.34 (95% CI 1.24, 1.44), 1.50 (95% CI 1.26, 1.78), and 1.58 (95% CI 1.09, 2.28), respectively. CONCLUSION: The study showed an increase in preterm and post-term pregnancies after induced abortions. The risk of post-term delivery was high regardless of the interpregnancy interval, whereas increased risk of preterm delivery was seen mainly when interpregnancy intervals were longer than 12 months.

Abortion, Induced↗

Wolbachia infections are distributed throughout insect somatic and germ line tissues.

Wolbachia are intracellular microorganisms that form maternally-inherited infections within numerous arthropod species. These bacteria have drawn much attention, due in part to the reproductive alterations that they induce in their hosts including cytoplasmic incompatibility (CI), feminization and parthenogenesis. Although Wolbachia's presence within insect reproductive tissues has been well described, relatively few studies have examined the extent to which Wolbachia infects other tissues. We have examined Wolbachia tissue tropism in a number of representative insect hosts by western blot, dot blot hybridization and diagnostic PCR. Results from these studies indicate that Wolbachia are much more widely distributed in host tissues than previously appreciated. Furthermore, the distribution of Wolbachia in somatic tissues varied between different Wolbachia/host associations. Some associations showed Wolbachia disseminated throughout most tissues while others appeared to be much more restricted, being predominantly limited to the reproductive tissues. We discuss the relevance of these infection patterns to the evolution of Wolbachia/host symbioses and to potential applied uses of Wolbachia.

Animals↗

Induced abortion and duration of third stage labour in a subsequent pregnancy.

We set out to evaluate the impact of first trimester induced abortion on the duration of third stage labour and related complications in a subsequent pregnancy. The study was conducted in Shanghai city at 15 general hospitals (or maternity and infant health institutes) from November 1993 to March 1998. We identified all nulliparae who came for antenatal care within the first 63 days of pregnancy (2953); the women were divided into two cohorts according to their previous history of first trimester induced abortion. After enrollment, the women were interviewed five times from recruitment until 42 days after delivery. We included in the study all 1363 women who had a singleton vaginal live birth. Of these women, 703 were primigravida (non-exposed), 534 had had one previous first trimester induced abortion, and 126 women had had two or more first trimester induced abortions. The duration of third stage labour in minutes was longer in women with one or more previous induced abortions (mean=7.32 minutes) compared with primigravid women (mean=6.79 minutes). Prolonged third stage labour (>30 minutes) following one or more induced abortions was seen for 3.4% versus 1.0% in primigravid women. After adjusting for a number of potential confounders, women with one or more previous first trimester induced abortions had an odds ratio of prolonged third stage labour of 2.59 (95%C.I.=1.06-6.37) compared with primigravida, especially after an interpregnancy interval of more than 6 months (OR=3.24, 95%C.I.=1.29-8.13). The odds ratio of prolonged third stage labour was 3.14 (95%C.I.=1.22-8.09) if gestational age at the time of the induced abortion exceeded 49 days. Women with a first trimester induced abortion had no significantly increased risk of postpartum haemorrhage or retained placenta. It was concluded that a history of one or more first trimester induced abortions was related to an increased risk of prolonged third stage labour in the following pregnancy, particularly if the induced abortion was performed after 49 days of gestation.

Journal Article↗

Tachycardia-induced subendocardial necrosis in acutely instrumented dogs with fixed coronary stenosis.

UNLABELLED: It has been speculated but never proven that tachycardia-induced ischemia per se may lead to myocardial infarction. In 17 anesthetized dogs, the proximal left anterior descending (LAD) artery was cannulated and perfused via bypass from the left subclavian artery. Distal LAD pressure was reduced by a screw clamp to cause > or =20% decrease in wall thickening during pacing tachycardia but no decrease in resting heart rate (approximately 90 bpm). Dogs were randomly assigned to three groups: 1) control (n = 6) maintained at resting heart rate (approximately 90 bpm) and mean coronary pressure of 49+/-5 mm Hg for 4 h; 2) 4-h ischemia (n = 6), paced at 150 bpm and mean coronary pressure maintained at 59+/-6 mm Hg for 4 h; and 3) 1-h ischemia (n = 5), paced at 150 bpm and mean coronary pressure of 54+/-8 mm Hg for 1 h. Myocardial blood flow and infarct area were measured by radiolabeled microspheres and triphenyl-tetrazolium chloride staining, respectively. Despite the higher coronary pressure in the 4-h ischemia group (P = 0.02), patchy subendocardial necrosis occurred in all these dogs and in two of the 1-h ischemia dogs, and one control dog had minimal papillary muscle necrosis. Infarct area was largest in the 4-h ischemic group (15.5%+/-9.1%) compared with control and 1-h ischemia groups (0.09%+/-0.2% and 1.6%+/-2.1%, respectively) (P < 0.002). Relative (risk/ nonrisk areas) subendocardial flow was lower at the end of ischemia in the 4- and 1-h ischemia groups compared with the control group (0.3+/-0.1 and 0.4+/-0.1 vs 0.9+/-0.2; P = 0.008 and 0.01, respectively). Prolonged tachycardia-induced ischemia, in the face of fixed coronary stenosis causing no ischemia at the resting heart rate, leads to patchy subendocardial necrosis, despite anticoagulation and antiplatelet treatment. IMPLICATIONS: Prolonged tachycardia-induced ischemia, in the face of fixed coronary stenosis causing no ischemia at the resting heart rate, leads to subendocardial infarction in dogs. These findings suggest a possible mechanism for postoperative myocardial infarction.

Animals↗

Propofol-induced alterations in myocardial beta-adrenoceptor binding and responsiveness.

UNLABELLED: Propofol (iv) depresses cardiovascular function in both humans and animals. However, the mechanism underlying this action has not been well described. The present study was designed to test the hypothesis that this effect of propofol results in part from an antagonism of adrenergic control of the heart. Experiments examined effects of propofol on: 1) [3H]CGP12177 (a beta-adrenoceptor antagonist) binding in rat myocardial membranes; and 2) the inotropic and chronotropic actions of isoproterenol in rat left atrial muscle and right atria, respectively. Propofol (25-200 microM) increased the apparent dissociation constant for [3H]CGP12177 without affecting binding site density. Similarly, 200 microM propofol increased the 50% effective concentration values for the dose-dependent positive chronotropic and inotropic actions of isoproterenol in right and left atria, and depressed the maximum increase in spontaneous rate elicited by this beta-adrenoceptor agonist. Other experiments demonstrated that propofol does not alter muscarinic receptor binding as monitored using [3H]quinuclidi-nylbenzilate. In conclusion, these results indicate that propofol can decrease cardiac beta-adrenoceptor responsiveness; however, the concentrations of propofol required suggest that this action contributes to the cardiovascular depression produced by this anesthetic only during large-dose bolus injection. IMPLICATIONS: Experiments in membranes and cardiac preparations isolated from rat heart demonstrate that relatively high concentrations of propofol (25-200 microM) are required to antagonize beta-adrenoceptor binding and tissue responsiveness.

Adrenergic beta-Agonists↗

Concatamerization of adeno-associated virus circular genomes occurs through intermolecular recombination.

Long-term recombinant AAV (rAAV) transgene expression in muscle has been associated with the molecular conversion of single-stranded rAAV genomes to high-molecular-weight head-to-tail circular concatamers. However, the mechanisms by which these large multimeric concatamers form remain to be defined. To this end, we tested whether concatamerization of rAAV circular intermediates occurs through intra- or intermolecular mechanisms of amplification. Coinfection of the tibialis muscle of mice with rAAV alkaline phosphatase (Alkphos)- and green fluorescent protein (GFP)-encoding vectors was used to evaluate the frequency of circular concatamer formation by intermolecular recombination of independent viral genomes. The GFP shuttle vector also encoded ampicillin resistance and contained a bacterial origin of replication to allow for bacterial rescue of circular intermediates from Hirt DNA of infected muscle samples. The results demonstrated a time-dependent increase in the abundance of rescued plasmids encoding both GFP and Alkphos, which reached 33% of the total circular intermediates by 120 days postinfection. Furthermore, these large circular concatamers were capable of expressing both GFP- and Alkphos-encoding transgenes following transient transfection in cell lines. These findings demonstrate that concatamerization of AAV genomes in vivo occurs through intermolecular recombination of independent monomer circular viral genomes and suggest new viable strategies for delivering multiple DNA segments at a single locus. Such developments will expand the utility of rAAV for splicing large gene inserts or large promoter-gene combinations carried by two or more independent rAAV vectors.

Alkaline Phosphatase↗

Dominant negative murine serum response factor: alternative splicing within the activation domain inhibits transactivation of serum response factor binding targets.

Primary transcripts encoding the MADS box superfamily of proteins, such as MEF2 in animals and ZEMa in plants, are alternatively spliced, producing several isoformic species. We show here that murine serum response factor (SRF) primary RNA transcripts are alternatively spliced at the fifth exon, deleting approximately one-third of the C-terminal activation domain. Among the different muscle types examined, visceral smooth muscles have a very low ratio of SRFDelta5 to SRF. Increased levels of SRFDelta5 correlates well with reduced smooth muscle contractile gene activity within the elastic aortic arch, suggesting important biological roles for differential expression of SRFDelta5 variant relative to wild-type SRF. SRFDelta5 forms DNA binding-competent homodimers and heterodimers. SRFDelta5 acts as a naturally occurring dominant negative regulatory mutant that blocks SRF-dependent skeletal alpha-actin, cardiac alpha-actin, smooth alpha-actin, SM22alpha, and SRF promoter-luciferase reporter activities. Expression of SRFDelta5 interferes with differentiation of myogenic C2C12 cells and the appearance of skeletal alpha-actin and myogenin mRNAs. SRFDelta5 repressed the serum-induced activity of the c-fos serum response element. SRFDelta5 fused to the yeast Gal4 DNA binding domain displayed low transcriptional activity, which was complemented by overexpression of the coactivator ATF6. These results indicate that the absence of exon 5 might be bypassed through recruitment of transcription factors that interact with extra-exon 5 regions in the transcriptional activating domain. The novel alternatively spliced isoform of SRF, SRFDelta5, may play an important regulatory role in modulating SRF-dependent gene expression.

3T3 Cells↗

Suppression of beta-adrenergic responsiveness of L-type Ca2+ current by IL-1beta in rat ventricular myocytes.

The possible mechanism by which interleukin-1beta (IL-1beta) affects beta-adrenergic responsiveness of L-type Ca2+ current (ICa,L) was examined in adult rat ventricular myocytes by use of whole cell patch-clamp techniques. In the presence of isoproterenol (Iso), exposure for 3 min to IL-1beta suppressed the Iso-activated ICa,L. In the presence of IL-1beta, the response of ICa,L to Iso was decreased, and the EC50 for Iso stimulation was increased. However, IL-1beta had no effect on [3H]CGP-12177 binding, displacement of [3H]CGP-12177 binding by Iso, or on basal and Iso-enhanced cAMP content. When ICa,L was activated by extracellular application of forskolin or 8-(4-chlorophenylthio)-cAMP, a membrane-permeable cAMP analog, or by intracellular dialysis with cAMP, IL-1beta had little effect on ICa,L. In contrast, in the presence of cAMP, IL-1beta still suppressed the Iso-enhanced ICa,L. These results show that the IL-1beta-induced decrease in beta-adrenergic responsiveness of ICa,L does not result from inhibition of beta-adrenoceptor binding, adenylyl cyclase activity, or cAMP-mediated pathways, suggesting a cAMP-independent mechanism.

Animals↗

Submucosal gland development in the airway is controlled by lymphoid enhancer binding factor 1 (LEF1).

Previous studies have demonstrated that transcription of the lymphoid enhancer binding factor 1 (Lef1) gene is upregulated in submucosal gland progenitor cells just prior to gland bud formation in the developing ferret trachea. In the current report, several animal models were utilized to functionally investigate the role of LEF1 in initiating and supporting gland development in the airway. Studies on Lef1-deficient mice and antisense oligonucleotides in a ferret xenograft model demonstrate that LEF1 is functionally required for submucosal gland formation in the nasal and tracheal mucosa. To determine whether LEF1 expression was sufficient for the induction of airway submucosal glands, two additional model systems were utilized. In the first, recombinant adeno-associated virus was used to overexpress the human LEF1 gene in a human bronchial xenograft model of regenerative gland development in the adult airway. In a second model, the LEF1 gene was ectopically overexpressed under the direction of the proximal airway-specific CC10 promoter in transgenic mice. In both of these models, morphometric analyses revealed no increase in the number or size of airway submucosal glands, indicating that ectopic LEF1 expression alone is insufficient to induce submucosal gland development. In summary, these studies demonstrate that LEF1 expression is required, but in and of itself is insufficient, for the initiation and continued morphogenesis of submucosal glands in the airway.

Adult↗

Apical proteins stimulate complement synthesis by cultured human proximal tubular epithelial cells.

There is increasing evidence to suggest that the renal tubular epithelium is important in the pathogenesis of progressive renal failure resulting from persistent proteinuria. The role of complement in the progression of chronic renal failure is not well defined. The purpose of this study was to characterize the production of complement by human proximal tubular epithelial cells exposed to serum proteins at the apical surface. Complement C3 gene expression was analyzed by reverse transcription and PCR. C3 protein biosynthesis was confirmed by metabolic labeling followed by immunoprecipitation and quantified by enzyme-linked immunosorbent assay. In the quiescent state, proximal tubular epithelial cells grown on permeable membrane supports secreted C3 predominantly into the apical medium. The addition of 5 mg/ml serum proteins led to an 8.9-fold increase in basolateral C3 secretion and a 2.1-fold increase in apical C3 secretion, altering the ratio of basolateral: apical C3 secretion from 0.44 +/- 0.16 to 1.87 +/- 0.52. C3 mRNA expression was also upregulated in a time- and dose-dependent manner. Serum fractionation demonstrated that the stimulant responsible for these effects was in the molecular weight range 30 to 100 kD. The observed phenomenon was not reproduced when purified human albumin alone was used as the stimulant. These findings could provide a possible mechanism for the link between proteinuria and interstitial fibrosis. This may have potential implications for strategies directed against complement in retarding the progression of chronic renal failure.

Cells, Cultured↗

Interaction of angiotensin II and mechanical stretch on vascular endothelial growth factor production by human mesangial cells.

The antiproteinuric effect of angiotensin-converting enzyme inhibitors underscores the importance of a hemodynamic injury and the renin-angiotensin system in the proteinuria of various glomerular diseases. Vascular endothelial growth factor (VEGF), a potent promoter of vascular permeability, is induced in mesangial cells by both mechanical stretch and TGF-beta1. This study investigates the effect of TGF-beta blockade, angiotensin II (AngII), and the interaction between AngII and stretch on human mesangial cell VEGF production. Exposure to AngII (1 microM) induced a significant increase in VEGF mRNA and protein levels (1.5+/-0.1 and 1.7+/-0.3, respectively, fold increase over control, P<0.05). The AngII receptor (AT1) antagonist Losartan (10 microM) prevented AngII-induced, but not stretch-induced, VEGF protein secretion (AngII 1.7+/-0.3, AngII + Losartan 1.0+/-0.1, P<0.05; stretch 2.4+/-0.4, stretch + Losartan 2.6+/-0.5). Stretch-induced VEGF production was also unaffected by the addition of an anti-TGF-beta neutralizing antibody (stretch 2.85+/-0.82 versus stretch + anti-TGF-beta 2.84+/-0.01, fold increase over control). Simultaneous exposure to both AngII and stretch for 12 h had an additive effect on VEGF production (AngII 1.6+/-0.1, stretch 2.6+/-0.27, AngII + stretch 3.1+/-0.35). Conversely, preexposure to stretch magnified AngII-induced VEGF protein secretion (unstretched + AngII 1.3+/-0.0, stretched + AngII 1.9+/-0.1, P<0.01) with a parallel 1.5-fold increase in AT1 receptor levels. AngII and stretch can both independently induce VEGF production; in addition, mechanical stretch upregulates the AT1 receptor, enhancing the cellular response to AngII.

Analysis of Variance↗

Mice transgenic for an expanded CAG repeat in the Huntington's disease gene develop diabetes.

The autosomal dominant neurological syndrome of Huntington's disease has been modeled in transgenic mice by the expression of a portion of the human huntingtin gene together with 140 CAG repeats (the R6/2 strain). The mice develop progressive chorea with onset at approximately 9 weeks of age and with death at approximately 13 weeks. Associated symptoms include weight loss and polyuria in the absence of eating or drinking deficits. We have found that these mice have insulin-responsive diabetes. Fasting glucose was 211 + 19 mg/dl in R6/2 mice compared with 93 + 5 mg/dl in C57/B6 controls (n = 12, both groups; P < 0.01). Administration of insulin intraperitoneally led to a reduction in blood glucose. At 12.5 weeks, animals were killed and pancreas weighed and analyzed for insulin and glucagon. Pancreatic mass in R6/2 mice was the same as controls, and islets appeared normal in morphology without lymphocytic infiltration. Immunohistochemical staining showed dramatic reductions in glucagon in the alpha-cells and in insulin in the beta-cells. Direct tissue assays showed glucagon and insulin content were reduced to only 10 and 15% of controls, respectively. Diabetes has been reported as being more common in Huntington's disease and other triplet repeat disorders. The R6/2 mouse should prove useful for elucidating the mechanism of diabetes in these genetic diseases.

Aging↗