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Biomedical subjects

H Wu

Publications and source records attributed to H Wu.

At least 379 records · Page 21Linked to original sources
PubMed1999

Nesidioblastosis, myelodysplastic syndrome and nodular diabetic glomerulosclerosis in an elderly nondiabetic woman: an autopsy report.

Nesidioblastosis as the cause of hyperinsulinaemic hypoglycaemia in an adult is rare. We report here an additional case of nesidioblastosis, which resulted in fatal hyperinsulinaemic hypoglycaemia in a 72-year-old woman with an underlying myelodysplastic syndrome. The diagnosis of nesidioblastosis was established only after post-mortem examination with a careful exclusion of minute insulinoma. To our surprise, the renal pathology disclosed typical diabetic nodular glomerulosclerosis in the same patient who had no previous history of diabetes mellitus (DM). Nesidioblastosis has been reported to cause 'reversal' of Type 1 DM and insulinoma causing 'reversal' of Type 2 disease. We therefore hypothesize that our patient might have had an undiagnosed DM in the past, which resulted in the typical diabetic nodular glomerulosclerosis. The nesidioblastosis caused a 'reversal' of DM and even the ultimate development of hyperinsulinaemic hypoglycaemia.

Aged↗
PubMed1999

Conserved T-cell receptor beta chain CDR3 sequences in IgA nephropathy biopsies.

BACKGROUND: We have previously reported that both alpha beta and gamma delta T cells are involved in the progression of IgA nephropathy (IgAN) to renal failure. To determine whether the T-cells seen in the interstitium represent a generalized inflammatory response or whether they are proliferating oligoclonally in response to a particular antigen, we analyzed the TCR Vbeta gene usage by T cells infiltrating renal biopsies from patients with IgAN. METHODS: Fourteen IgAN patients were divided by clinical criteria into stable and progressive groups (7 in each group). Reverse transcription-polymerase chain reaction (RT-PCR) and cloning were used to characterize the expression of TCR Vbeta families in renal biopsies and in peripheral blood lymphocytes. RESULTS: TCR Vbeta8 was significantly and preferentially expressed in most IgAN kidney biopsies compared with peripheral blood lymphocytes from both IgAN patients and healthy controls (P < 0.001). TCR Vbeta8 expression was more marked in progressive biopsies than in stable biopsies (P < 0.05). Spectratyping of Vbeta8 RT-PCR products from T cells infiltrating the kidney showed an intense spectratype band at the shortest range of amplified CDR3s in the renal biopsies of four patients. Analysis of nucleotide and deduced amino acid sequences of Vbeta8 PCR products derived from intense spectratype bands from these renal biopsies revealed a high concordance across the CDR3 region. A conserved amino acid (leucine) at the first position of the nongermline-encoded nucleotides and diversity (ND) junction of Vbeta8 was found at a frequency of 95% in multiple sequences obtained from the renal biopsies of all four patients examined. CONCLUSIONS: The preferential use of Vbeta8 with marked similarities in the CDR3 region by some renal infiltrating T cells suggests clonal expansion of T cells in the kidneys of some IgAN patients. Conserved amino acids in the TCR CDR3 hypervariable region may contribute to the recognition of a particular antigen or set of antigens.

Adult↗
PubMed1999

Colloidal bismuth pectin: an alternative to bismuth subcitrate for the treatment of Helicobacter pylori--positive duodenal ulcer.

BACKGROUND: Bismuth triple therapy provides consistently good results in Helicobacter pylori eradication worldwide, whereas quadruple therapy using a combination of omeprazole and bismuth triple regimen has produced cure rates in excess of 90%. The prevalence of metronidazole-resistant strains was 26.8% in our area. Colloidal bismuth pectin (CBP) is a new, lower-priced bismuth salt made in China. The purpose of this study was to investigate the efficacy and safety of CBP triple and quadruple regimens in the treatment of H. pylori-positive duodenal ulcer. MATERIALS AND METHODS: In this prospective trial, 205 patients with H. pylori-positive duodenal ulcer were allocated randomly to receive one of four regimens: metronidazole, 200 mg; amoxicillin, 250 mg; and colloidal bismuth subcitrate (CBS), 120 mg (group 1), or CBP, 100 mg qid (group 2) for 2 weeks, then continued CBS, 240 mg, or CBP, 200 mg bid for a further 2 weeks. A quadruple regimen using a combination of omeprazole, 20 mg bid, and CBS triple therapy (group 3) or CBP triple therapy (group 4), respectively, was given to patients for 1 week, followed by omeprazole, 20 mg once daily for a further 3 weeks. Further endoscopy was performed at least 4 weeks after cessation of the treatment. H. pylori status was determined by histology, a 14C urea breath test, and a urease test. RESULTS: The per-protocol H. pylori cure rates were 85% (22 of 26 patients), 90% (35 of 39), 96% (46 of 48), and 95% (75 of 79) for groups 1 through 4. In the intention-to-treat analysis, cure rates were 79% (22 of 28), 83% (35 of 42), 90% (46 of 51), and 89% (75 of 84), respectively. The cure rates of quadruple therapy were higher than those of triple therapy; an 8.2% difference was not statistically significant (95% confidence interval [CI], 2.3-18.7%). The ulcer-healing rates were 88%, 87%, 98%, and 97%, respectively, for groups 1 through 4. The ulcer pain was relieved more rapidly in quadruple- than in triple-therapy regimens. Two patients discontinued treatment prematurely owing to drug-related side effects. CONCLUSION: One-week quadruple therapy is highly effective and safe in H. pylori eradication in Chinese patients. CBP is as effective as CBS.

Adolescent↗
PubMed1999

Comparison of different wound closure techniques in translabyrinthine acoustic neuroma surgery.

In a series of 277 patients with translabyrinthine acoustic neuroma, three techniques of wound closure were used to prevent cerebrospinal fluid (CSF) leakage. In the first group, we used a piece of fascia to cover the dural defect and then placed several pieces of fat on the fascia. The incidence of CSF leak was 28.2%; 7.7% required reoperation. In the second group, in addition to the fasia-fat complex, we made a large musculoperiosteal flap to compress the fat. The incidence of CSF leak and revision were not reduced, however. In recent cases, we placed several pieces of fat directly into the operative cavity without fascia graft; then it was covered with a musculoperiosteal flap. With this technique, CSF leak was significantly reduced to 7.4%, and reoperation was rare (3.7%). The direct application of fat into the translabyrinthine operation cavity appears to be effective to prevent CSF leaks.

Journal Article↗
PubMed1999

Catecholamine storage vesicle protein expression in genetic hypertension.

Chromogranin A expression is heritable in humans, and both plasma chromogranin A concentration and its releasable adrenal and sympathetic neuronal pools are augmented in established essential (hereditary) hypertension. To evaluate chromogranin A further as a simpler or "intermediate phenotype" in the complex trait of hypertension, we studied chromogranin A expression in the spontaneously hypertensive rat (SHR), a rodent model of essential hypertension. Both plasma (p < 0.0001) and adrenal medullary (p = 0.003 to p < 0.0001) chromogranin A were elevated in the SHR, even at the earliest stages (3-4 weeks of age). In the adult adrenal gland, both chromogranin A (p=0.005) and norepinephrine (p=0.011) were increased in the SHR, while dopamine beta-hydroxylase activity was diminished (p < 0.0001). Chromogranin A mRNA expression was also elevated in the SHR adrenal medulla (p = 0.017). Differences in chromogranin A processing were not noted between SHR and Wistar Kyoto control (WKY) rats. In an SHR x WKY genetic intercross, control of the adrenal chromogranin A phenotype by a single major locus was suggested by comparison of phenotypic variance of the F2 vs F1 generations, and by bimodal frequency histogram (3:1 ratio), confirmed by maximum likelihood analysis (chi2 = 74.6, p < 0.000001) in the F2 generation. However, microsatellite alleles at a surrogate locus (Ighe) 12.7 cM from chromogranin A (Chga), on rat chromosome 6, failed to co-segregate with blood pressure in an F2 generation (F = 0.06, p = 0.94). In another rodent model of hereditary hypertension, the genetically hypertensive mouse (BPH/2), adrenal chromogranin A (p=0.018) and norepinephrine (p = 0.004) were actually diminished. We conclude that over-expression of chromogranin A is a variable feature of mammalian genetic hypertension. In one rodent model (the SHR), over-expression of chromogranin A is largely controlled by a single genetic locus, but the chromogranin A locus itself is not directly linked to determination of the blood pressure elevation of the SHR.

Adrenal Medulla↗
PubMed1999

Estimate of the frequency of true incomplete exchanges in human lymphocytes exposed to 1 GeV/u Fe ions in vitro.

PURPOSE: To study the frequency of true incomplete exchanges induced by high-LET radiation. MATERIALS AND METHODS: Human lymphocytes were exposed to 1 GeV/u Fe ions (LET = 140 keV/microm). Chromosome aberrations were analysed by a fluorescence in situ hybridization using a combination of whole-chromosome-specific probes and human telomere probes. Chromosomes 1, 3 and 4 were investigated. RESULTS: The percentage of incomplete exchanges was between 23 and 29% if telomere signals were not considered. The percentage decreased to approximately 10% after ruling out false incomplete exchanges containing telomere signals. The final estimation of true incomplete exchanges was <10%. CONCLUSION: Within a degree of uncertainty, the percentage of true incomplete exchanges in 1 GeV/u Fe ion-irradiated human lymphocytes was similar to that induced by gamma rays.

Chromosome Aberrations↗
PubMed1999

Characterization of viral dynamics in human immunodeficiency virus type 1-infected patients treated with combination antiretroviral therapy: relationships to host factors, cellular restoration, and virologic end points.

Biphasic plasma viral decays were modeled in 48 patients treated with ritonavir, zidovudine, and lamivudine. Estimated first- and second-phase decay rates were d1 as 0.47/day and d2 as 0.04/day. Interpatient differences in both decay rates were significant. The d1 was directly correlated with baseline CD4+, CD4+CD28+, and CD8+CD28+ T lymphocyte counts (P<.05) and inversely correlated with baseline virus load (P=.044) and the magnitude of CD4+ and CD8+ T lymphocyte recovery (P<.01). The d2 was directly correlated with baseline percentage of CD8+ T lymphocytes (P=.023), the CD8+CD38+ cell number (P=.024), and the level of IgG that binds to human immunodeficiency virus (HIV) type 1 gp120 (P=.02). Viral decay rates were not predictive of treatment failure or durability of viral suppression. These exploratory findings are consistent with a model in which immunologic factors contribute to elimination of HIV-infected cells and suggest a dynamic interplay between regulation of HIV expression and lymphocyte activation and recovery.

ADP-ribosyl Cyclase↗
PubMed1999

Post-fine-needle aspiration spindle cell nodules of the thyroid (PSCNT).

Postoperative spindle cell proliferations have been well described in the lower genitourinary tract. These lesions show an exuberant proliferation of spindle cells with bland cytology and numerous mitoses. We report similar lesions in the thyroid gland of 10 patients who had undergone fine-needle aspiration (FNA). The proliferations were nodular, measured 1 to 7 mm, and were relatively circumscribed and nonencapsulated. In most cases, they were limited to the central part of the preexisting thyroid lesions and showed plump spindle cells with a rich network of thin-walled blood vessels and an inflammatory component constituted mainly of histiocytes and few lymphocytes. Mitotic figures were exceedingly rare. Immunostains showed diffuse positivity with smooth muscle actin, suggesting a myofibroblastic nature to the spindle cell component, and endothelial markers highlighted a network of thin-walled blood vessels. The histiocytic component stained with the macrophage marker CD68. The degree of cellularity was variable and may be related to the interval between FNA and surgery, size of the biopsy needle, and undetermined host response factors. We believe it is important to recognize these nodules as posttraumatic benign lesions without clinical consequence to avoid misdiagnosis of other lesions in thyroid-containing spindle cells, such as anaplastic carcinoma, medullary carcinoma, and sarcoma.

Adult↗
PubMed1999

Chronic stress associated with spousal caregiving of patients with Alzheimer's dementia is associated with downregulation of B-lymphocyte GH mRNA.

BACKGROUND: It has been demonstrated that growth hormone (GH) is synthesized and secreted by human peripheral mononuclear cells (PBMC), and the expression of GH mRNA can be found throughout the human immune system. METHODS: We studied a population of female caregivers of patients with Alzheimer's dementia (AD) who suffered from the stress of caring for these patients. We utilized quantitative RT-PCR to determine GH mRNA levels in T- and B-cell populations from PBMC. Subjects were nine caregivers of AD patients and nine age- and sex-matched controls. RESULTS: In the control group we found a threefold greater GH mRNA expression in B cells than in T cells. This finding was consistent with our previous in situ hybridization observation, suggesting GH mRNA in predominately B-cell areas of immune organs in humans. We also found that the expression of GH mRNA from total peripheral blood mononuclear cells and B cells in caregivers was 50% and 60% respectively less than that in the control group. CONCLUSIONS: Because the B-cell population is the source of antibody production, our findings suggest that the decrease in B-cell GH mRNA may contribute to the poor immune response to influenza virus vaccination that has been reported previously in chronically stressed caregivers.

Aged↗
PubMed1999

Population HIV-1 dynamics in vivo: applicable models and inferential tools for virological data from AIDS clinical trials.

In this paper, we introduce a novel application of hierarchical nonlinear mixed-effect models to HIV dynamics. We show that a simple model with a sum of exponentials can give a good fit to the observed clinical data of HIV-1 dynamics (HIV-1 RNA copies) after initiation of potent antiviral treatments and can also be justified by a biological compartment model for the interaction between HIV and its host cells. This kind of model enjoys both biological interpretability and mathematical simplicity after reparameterization and simplification. A model simplification procedure is proposed and illustrated through examples. We interpret and justify various simplified models based on clinical data taken during different phases of viral dynamics during antiviral treatments. We suggest the hierarchical nonlinear mixed-effect model approach for parameter estimation and other statistical inferences. In the context of an AIDS clinical trial involving patients treated with a combination of potent antiviral agents, we show how the models may be used to draw biologically relevant interpretations from repeated HIV-1 RNA measurements and demonstrate the potential use of the models in clinical decision-making.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Cathelicidin gene expression in porcine tissues: roles in ontogeny and tissue specificity.

Cathelicidins constitute a family of mammalian antimicrobial peptides that are synthesized in the bone marrow as prepropeptides, stored in neutrophil granules as propeptides, and released as active, mature peptides upon neutrophil degranulation. We investigated the developmental expression of two porcine cathelicidins, PR-39 and protegrin. Both cathelicidins were expressed constitutively in the bone marrow of all pigs at all of the ages tested. Peripheral blood neutrophils from young pigs expressed PR-39 and protegrin mRNA, which were not detectable at 42 days of age. At earlier ages, expression of PR-39 mRNA was detected in the kidney and liver and several lymphoid organs, including the thymus, spleen, and mesenteric lymph nodes, but disappeared at 4 weeks of age. These data provide the first evidence of cathelicidin gene expression in peripheral leukocytes and may indicate a role for these antimicrobial peptides in the development of host defense mechanisms.

Animals↗
PubMed1999

Porcine epithelial beta-defensin 1 is expressed in the dorsal tongue at antimicrobial concentrations.

Epithelial cells and phagocytes contain antimicrobial polypeptides that participate in innate host defense. A recently cloned porcine beta-defensin, PBD-1, was detected by Northern organ blots exclusively in the tongue epithelium. We generated recombinant PBD-1 peptide by using a baculovirus-insect cell expression system and obtained two forms (PBD-142 and PBD-138), which differed by N-terminal truncation. Only PBD-142 was found in scrapings of the surface of the dorsal tongue or the buccal mucosa. Immunohistochemical staining with antibody to PBD-142 revealed that PBD-1 was highly concentrated in an approximately 0.1-mm-thick layer in the cornified tips of the filiform (but not fungiform) papillae of the dorsal tongue and in the superficial squamous cell layers of the buccal mucosa. By scraping, extraction, and semiquantitative Western blotting, the concentration of PBD-1 in the dorsal tongue surface and the buccal mucosa was estimated at 20 to 100 micrograms/ml. PBD-1 had antibacterial activity against Escherichia coli, Salmonella typhimurium, Listeria monocytogenes, and Candida albicans in 10 mM sodium phosphate buffer (pH 7.4). Added NaCl progressively inhibited the activity of PBD-1 against E. coli and C. albicans. In 10 mM sodium phosphate with 125 mM NaCl, the combinations of sublethal concentrations of PBD-1 and the porcine neutrophil peptide PG-3, PR-39, or PR-26 showed synergistic activity against E. coli or the multidrug-resistant S. typhimurium DT104. At its physiologic concentration, PBD-1 has antimicrobial effects under both low- and high-salt conditions encountered in the oral cavity and may contribute to the antimicrobial barrier properties of the dorsal tongue and oral epithelium.

Amino Acid Sequence↗
PubMed1999

Dynamics of human immunodeficiency virus type 1 replication in vertically infected infants.

Plasma human immunodeficiency virus type 1 (HIV-1) turnover and kinetics were studied in children aged 15 days to 2 years following the initiation of a triple antiretroviral drug regimen consisting of zidovudine, lamivudine, and nevirapine. HIV-1 turnover was at least as rapid as that previously described in adults; turnover rates were more rapid in infants and children aged 3 months to 2 years than in infants less than 3 months of age. These data confirm the central role of HIV-1 replication in the pathogenesis of vertical HIV-1 infection and reinforce the importance of early, potent combination therapies for the long-term control of HIV-1 replication.

Acquired Immunodeficiency Syndrome↗
PubMed1999

MRI changes during water loading in patients with polydipsia and intermittent hyponatremia.

OBJECTIVE: Patients with polydipsia and intermittent hyponatremia have greater ventricle-brain ratios (VBRs) than matched patients without polydipsia and intermittent hyponatremia and normal subjects. Unlike previous studies, this study controlled for the impact of water loading when examining the volume of intracranial structures. METHOD: Under controlled conditions, eight male schizophrenic patients with polydipsia and intermittent hyponatremia were first assigned to either normal fluid intake or oral water loading and then the alternative condition the following day. Magnetic resonance imaging (MRI) volumetric measurements were made with the use of a standardized protocol. RESULTS: During water loading, total VBR and lateral ventricle volume significantly decreased by 13.1% and 12.6%, respectively. A strong association between change in serum sodium concentration and change in VBR was noted across conditions. CONCLUSIONS: These findings indicate that 1) water loading does not account for the diminished brain volume observed in patients with polydipsia and intermittent hyponatremia in previous studies, and 2) hyponatremia can significantly alter brain morphology on MRI.

Adult↗
PubMed1999

Inactivation of erythropoietin leads to defects in cardiac morphogenesis.

Erythropoietin is an essential growth factor that promotes survival, proliferation, and differentiation of mammalian erythroid progenitor cells. Erythropoietin(-/-) and erythropoietin receptor(-/-) mouse embryos die around embryonic day 13.5 due, in part, to failure of erythropoiesis in the fetal liver. In this study, we demonstrated a novel role of erythropoietin and erythropoietin receptor in cardiac development in vivo. We found that erythropoietin receptor is expressed in the developing murine heart in a temporal and cell type-specific manner: it is initially detected by embryonic day 10.5 and persists until day 14.5. Both erythropoietin(-/-) and erythropoietin receptor(-/-) embryos suffered from ventricular hypoplasia at day 12-13 of gestation. This defect appears to be independent from the general state of hypoxia and is likely due to a reduction in the number of proliferating cardiac myocytes in the ventricular myocardium. Cell proliferation assays revealed that erythropoietin acts as a mitogen in cells isolated from erythropoietin(-/-) mice, while it has no effect in hearts from erythropoietin receptor(-/-) animals. Erythropoietin(-/-) and erythropoietin receptor(-/-) embryos also suffered from epicardium detachment and abnormalities in the vascular network. Finally, through a series of chimeric analysis, we provided evidence that erythropoietin acts in a manner which is non-cell-autonomous. Our results elucidate a novel role of erythropoietin in cardiac morphogenesis and suggest a combination of anemia and cardiac failure as the cause of embryonic lethality in the erythropoietin(-/-) and erythropoietin receptor(-/-) animals.

Animals↗
PubMed1999

The human suprascapular nerve belongs to both anterior and posterior divisions of the brachial plexus.

For the sake of clarifying which division of the brachial plexus, anterior or posterior, does the human suprascapular nerve belong to, the suprascapular nerve and cervical nerves concerned were teased into bundles of fibers by the fiber analysis method in six adult human arms of cadavers. The suprascapular nerve received fibers from C4, C5 and C6 in two cases which have a communicating branch between C4 and C5, from C6 and C6 in three cases and only from C5 in one case. In contrast with the posterior root fibers, the anterior root fibers of C5 and C6 could easily be divided into anterior and posterior groups of bundles which entered the anterior and the posterior divisions of the brachial plexus and were called anterior motor and posterior motor elements respectively. The suprascapular nerve received fibers from the anterior and the posterior motor elements of C5 in all cases. In addition to the C5, the nerve received fibers from both elements of C6 in three cases or from the anterior element of C6 in two cases. From this result the suprascapular nerve is judged to be a nerve which belongs to both anterior and posterior divisions of the brachial plexus.

Adult↗
PubMed1999

Evidence for an improvement in cognitive function following treatment of Schistosoma japonicum infection in Chinese primary schoolchildren.

A double-blind, placebo-controlled, treatment trial was conducted in Sichuan, China to investigate the unique and combined effects on the cognitive function (working memory) of children after treating geohelminth infections with albendazole and treating Schistosoma japonicum infection with praziquantel. One hundred eighty-one children 5-16 years of age participated. At baseline, the praziquantel and placebo groups were similar in all background characteristics. Three months after praziquantel treatment, there was a significant reduction in the prevalence and intensity of S. japonicum infection. There were significant age group by praziquantel treatment interaction effects in three of the five cognitive tests, Fluency, Picture Search, and Free Recall, with effects being strongest in the youngest children (5-7 years old). Exploratory analysis within the youngest children showed a significant positive main effect of treatment on Fluency (P < 0.001), after controlling for sex, anthropometric, and parasitic and iron status. There was also a treatment by height-for-age interaction (P = 0.03) and a treatment by iron status interaction (P = 0.024) on Fluency. There was a treatment by S. japonicum intensity interaction (P < 0.001) on Free Recall, but the main effect of treatment on Picture Search was not significant (P = 0.058). Younger children and those who are physically the most vulnerable are likely to benefit the most from the treatment of S. japonicum infection in terms of improved performance on tests of working memory.

Adolescent↗