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Biomedical subjects

H C Hsu

Publications and source records attributed to H C Hsu.

At least 343 records · Page 19Linked to original sources
PubMedDate not supplied

Impaired gallbladder function in spinal cord injury on quantitative Tc-99m DISIDA cholescintigraphy.

BACKGROUND: Patients with spinal cord injury (SCI) have increased prevalences of gallstones and acute acalculous cholecystitis. A possible explanation for the increased prevalence of gallstone disease in SCI patients is decreased gallbladder motility causing gallbladder stasis, a known risk factor for gallstone disease. We investigated gallbladder function in SCI. METHODS: Twenty-five normal control subjects and 50 SCI patients were included in this study. Gallbladder function was measured by technium 99m-labeled imino-diacetic acid analogue (Tc-99m DISIDA) cholescintigraphy and represented by the filling fraction (FF) and the ejection fraction (EF). The SCI patients were assigned to subgroups: old versus young, female versus male, high- versus low-level injury, and long versus short injury duration. RESULTS: Forty-two percent of SCI patients had abnormal FFs and 54% of SCI patients had abnormal EFs. Significantly decreased FF and EF values were found in SCI patients, especially in those who were female and had high-level injuries. CONCLUSION: With the use of quantitative Tc-99m DISIDA cholescintigraphy, we found that SCI can significantly impair gallbladder function.

Adult↗
PubMedDate not supplied

Detection of hepatitis B virus DNA in hepatocellular carcinoma: methylation of integrated viral DNA.

In order to determine whether integrated hepatitis B virus DNA sequences in primary liver tumours are methylated we have analysed tumour DNA digested with either MspI or HpaII restriction endonuclease by Southern hybridization. Our results demonstrate methylation in 11 of 17 tumour DNA samples. Where possible, we have examined the tumour tissues for expression of HBsAg and HBcAg using the indirect immunoperoxidase technique. One tumour was positive for both HBsAg and HBcAg and a second was positive for HBsAg alone. Both of these tumours were in the group in which methylation of integrated HBV DNA sequences could not be detected. We postulate that methylation of integrated HBV DNA sequences may influence HBV gene expression in hepatocellular carcinoma.

Carcinoma, Hepatocellular↗
PubMedDate not supplied

High quality of DNA retrieved for Southern blot hybridization from microwave-fixed, paraffin-embedded liver tissues.

To overcome the degradation problem encountered in DNA extracted from formalin-fixed, paraffin-embedded tissue blocks, several methods of tissue fixation were examined in order to improve the quality of the DNA recovered for use in nucleic acid analysis. The fixation methods included formalin fixation alone, alcohol fixation alone, and microwave fixation with tissues immersed in phosphate-buffered saline (PBS), alcohol, or formalin. Unfixed fresh frozen tissue served as the control. Using hepatitis B virus (HBV) DNA sequences and the type I human procollagen gene as markers and liver tissue as a target, microwave fixation, with formalin omitted, not only preserved the DNA very well, but also the labile viral antigen. Both high molecular weight-integrated and free-form HBV DNAs were well preserved, and suitable for polymerase chain reaction and Southern blot analysis. The restriction enzyme fragment pattern of DNA recovered from these paraffin blocks was identical to that of unfixed fresh frozen tissue. Microwave fixation also preserved the labile preS2 epitope of the hepatitis B surface antigen (HBsAg) considerably better than formalin. These results suggest that microwave fixation is superior to routine formalin fixation for the preservation of excellent quality of genomic and viral DNAs for nucleic acid hybridization analysis. Alcohol, often used for nucleic acid purification, was also a good fixative for preserving DNA and the antigenicity of the labile antigen, especially when carried out in combination with microwave fixation.

Base Sequence↗
PubMedDate not supplied

Clinical features associated with correction of T-cell senescence: increased acute-phase response, amyloidosis and arthritis.

Two prominent features associated with immunosenescence are thymic involution and altered T-cell phenotype and responsiveness. We have shown previously that in CD2-fas transgenic mice, in which the Fas apoptosis molecule is constituatively expressed on T cells, T-cell senescence is greatly reduced. Using a different experimental approach, the relationship between T-cell senescence and apoptosis was analyzed on human PBMCs. The results indicate that there was increased apoptosis of CD45RO- (CD45RA+) T cells upon activation. We propose that this could account for the increase in CD45RO+ 'memory' T cells with aging in humans. Together these results are consistent with the notion that T-cell senescence is associated with altered apoptosis and decreased T-cell responsiveness. T-cell responsiveness remained high in CD2-fas transgenic aged mice, but there was no increase in overall life span of the mice. Increased T-cell responsiveness was associated with an increased acute-phase response and amyloid A deposition in the glomerulus of these mice. These data suggest that restoration of the T-cell immune function in aged individuals must be carried out in concert with correction of other immune factors that down modulate the acute-phase response to prevent undesirable side-effects.

Acute-Phase Reaction↗
PubMedDate not supplied

Influence of rotator cuff tearing on glenohumeral stability.

This study hypothesizes that full-thickness tearing of the rotator cuff can lead to joint instability and that the degree of instability depends on the size and location of the tear. Twelve cadaveric shoulder specimens were divided into two groups: group 1 had a circular tear centered at the critical area, and group 2 had a circular tear centered at the rotator interval. Each group was tested at 2.5 cm and 5 cm tear sizes. Unloaded, and with the arm in 90 degrees flexion and full internal rotation, the humeral head shifted posteriorly. With loading, a large and more anteriorly located defect had the most influence on stability. The tear size had the greatest effect on stability in the inferior direction for group 1 and on the anterior direction for group 2. The tear location had the most significant effect on stability in the inferior and anterior directions for the smaller tear and on the anterior direction for a larger tear.

Aged↗
PubMedDate not supplied

Mechanical environment associated with rotator cuff tears.

A simplified 2-dimensional finite element model was used to investigate the stress environment in the supraspinatus tendon. The extrafibrillar matrix and collagen fiber were modeled with fiber-reinforced composite elements. The stress was evaluated at humeroscapular elevation angles of 0 degree, 30 degrees, and 60 degrees. Two acromion conditions were simulated. In the first set of conditions there was no subacromial impingement. In the second set there was subacromial impingement of the bursal side. Impingement was simulated by producing a 1-mm indentation on the bursal surface, an indentation similar to the type of impingement associated with deltoid contraction. The results demonstrated that subacromial impingement generates high stress concentrations in and around the critical zone. Such high stress could initiate a tear; tears that result from stress point to an extrinsic mechanism. However, we found that high stress and potential tears caused by impingement may occur on the bursal side, the articular side, or within the tendon. This result is unaccounted for by traditional mechanical models in which only bursal-sided partial tears are initiated by subacromial impingement.

Aged↗
PubMedDate not supplied

Genetic dissection of age-related changes of immune function in mice.

Understanding of the genetic basis of normal and abnormal development of the immune response is an enormous undertaking. The immune response, at the most minimal level, involves interactions of antigen presenting cells (APCs), T and B cells. Each of these cells produce cell surface and soluble factors (cytokines) that affect both autocrine and paracrine functions. A second level of complexity needs to consider the development of the macrophage/monocyte lineage as well as the production of the common lymphoid precursor which undergoes distinct maturation steps in the thymus and periphery to form mature T cells as well as in BM (BM) and lymphoid organs to form mature B cells. A third level of complexity involves the immune response to infectious agents including viruses and also the response to tumour antigens. In addition, there are imbalances that predispose to decreased responses (immunodeficiencies) or increased responses (autoimmunity). A fourth level of complexity involves attempts to understand the differences in the immune response that occurs at a very young age, in adults, and at a very old age. This review will focus on the use of C57BL/6 J X DBA/2 J (BXD) recombinant inbred (RI) strains of mice to map genetic loci associated with the production of lymphoid precursors in the BM, development of T cells in the thymus, and T-cell responses to stimulation in the peripheral lymphoid organs in adult and in aged mice. Strategies to improve the power and precision in which complex traits such as the age-related immune response can be mapped is limited with the current set of 35 strains of BXD mice. Strategies to increase these strains by generating recombinant intercross (RIX) strains of mice are being developed to enable this large set of lines to detect quantitative trait loci (QTLs) with a much higher consistency and statistical power. More importantly, the resolution with which these QTLs can be mapped would be greatly improved and, in many cases, adequate to carry out direct identification of candidate genes. It is likely that, given the complexity of the immune system development, the number of cells involved in an immune response, and especially the changes in the immune system with ageing, mapping hundreds of genes will be required to fully understand age-related changes in the immune response. This review outlines ongoing and future strategies that will enable the mapping and identification of these genes.

Aging↗
PubMedDate not supplied

Long-term culture of fetal liver cells using a three-dimensional porous polymer substrate.

To develop a bioartificial liver, long-term culture of fetal liver cells over a month's time was performed under three different culture conditions, i.e., stationary cultures and shaken-flask cultures, both by using a substratum made of porous polyvinyl formal (PVF) resin and conventional monolayer dish cultures as controls. Time course changes in cell numbers and albumin secretion were evaluated in cultures using Williams' E medium (WE) or minimum essential medium alpha (aMEM) supplemented with serum and hormones. In the WE medium, the numbers of fetal liver cells in all culture conditions gradually decreased with time, and albumin secretion rates rapidly decreased. In the stationary cultures using PVF, however, a significant increase in albumin secretion was observed after two weeks of culture. When cells were cultured in aMEM, the fetal liver cells exhibited sufficient proliferation in stationary and monolayer cultures, although albumin secretion rates per single cell were lower than those in WE. On the basis of these results, another series of culture experiments were performed, in which aMEM was used for the first 10 days to encourage cell proliferation, and the medium was changed to WE afterward. In these cultures, albumin secretion rates in the stationary cultures dramatically increased after the medium exchanges and were maintained at these high levels throughout the remaining culture period.

Animals↗
PubMedDate not supplied

Neonatal hepatitis: a follow-up study.

Fifty-six patients with moderate to severe neonatal hepatitis were followed for 12 to 78 months. Two died from causes other than hepatitis itself and were free from liver disease at the time of death. Of the remaining 54 patients, seven died of hepatitis, two are living with chronic liver disease and psychomotor retardation, and 45 are living without liver disease. High peak bilirubin levels and liver histologic findings of periportal fibrosis, moderate to severe portal inflammation, and/or diffuse giant cell transformation appear to be major factors predictive for poor outcome. Cytomegalovirus (CMV) infection was a common associated infection. Evidence of CMV infection was found in 22 (49%) of the 45 patients studied. Three of them died, and one is still living with cirrhosis of the liver. Metabolic disorders such as alpha-1-antitrypsin deficiency, galactosemia, and aminoaciduria and/or aminoacidemia were carefully screened but were not found in these cases. A fatal case had a sibling who had died of a similar disease course. Chinese infants may have metabolic and familial cholestasis diseases requiring further investigation.

Bilirubin↗
PubMedDate not supplied

A comparative study of cefepime versus ceftazidime as empiric therapy of febrile episodes in neutropenic patients.

An open-label, randomized comparative study was conducted to evaluate the efficacy and safety of cefepime (2.0 g q. 8 h) and ceftazidime (2.0 g q. 8 h) in the empiric therapy of febrile neutropenic patients. A total of 45 eligible febrile episodes were randomized (1:1) to be treated with the study regimen. Nineteen febrile episodes treated with cefepime and 22 febrile episodes treated with ceftazidime were evaluable for efficacy. The two groups were comparable in terms of age, sex, height, weight, underlying neoplasm, number of pretherapy neutrophil, duration of neutropenia and types of infections. The overall therapeutic success rate of the cefepime group (53%) was comparable to the ceftazidime group (50%). It did not differ significantly (95% confidence interval: -0.28 to 0. 34, p = 0.85). Eighty-eight percent of pathogens in each group were bacteriologically eradicated. The safety profile was similar in both groups. No patients in either group discontinued the therapy because of adverse events. None (0%) of the cefepime patients and 2 (9%) of the ceftazidime patients died of infection. The results of this study suggest that cefepime is an effective and safe agent in the empiric therapy of febrile episodes in neutropenic patients.

Adult↗
PubMedDate not supplied

Posttraumatic benign pleomorphic adenoma of the lacrimal gland.

A 55-year-old man presented with a painless and slowly developing mass in the right superior lateral eyelid region. He had sustained periorbital blunt injury about 4 years previously. The mass was observed several months later in the persisting traumatic tumefaction region. Computed tomography showed a cystic soft-tissue mass with central low density and peripheral enhancement over the upper anterior quadrant of the right orbit. Lateral orbitotomy was performed to remove the lesion. Histopathologic examination showed proliferation of epithelial and myoepithelial cells arranged in ductules and nests in the myxoid stroma. Benign pleomorphic adenoma of the lacrimal gland associated with traumatic tumefaction, as demonstrated in our patient, may be rare.

Adenoma↗
PubMedDate not supplied

Orbital epithelial cyst derived from the lacrimal sac.

We describe a 32-year-old female who presented with a painless, moderately hard mass in the left inferior medial canthal region which had been present for about 6 years. She suffered from epiphora in the left eye in that time. The nasolacrimal system was completely patent on irrigation. Computed tomography showed a nodular mass with a diameter measuring about 25 mm located over the upper portion of the left lacrimal sac. The lesion was found to be a cyst located separately with close proximity to the lacrimal sac via anterior orbitotomy. Histopathologic examination revealed a cystic cavity lined by columnar to cuboidal epithelium consistent with a cyst derived from lacrimal sac epithelium. The patient has remained free of symptoms with a patent lacrimal system during the follow-up period of 1 year, without recurrence of the lesion. Orbital cysts of lacrimal sac derivation should be considered in the diagnosis of medial orbital tumors. Careful evaluation clinically with imaging studies and planning surgery constituted adequate therapy in this case.

Adult↗
PubMedDate not supplied

Corneal autofluorescence and epithelial barrier function in diabetic patients.

Corneal autofluorescence and corneal epithelial barrier function of 146 diabetic patients and 121 controls were examined using anterior segment fluorophotometry. Corneal autofluorescence in diabetic patients was significantly higher when compared with that of controls (14.6 +/- 3.7 vs. 10.9 +/- 2.7 ng/ml, p < 0.001), and was increased in patients with more severe diabetic retinopathy (r = 0.23, p = 0.005), higher postprandial blood glucose level (r = 0.25, p = 0.009), and higher glycosylated hemoglobin (r = 0.21, p = 0.047). No correlation existed between corneal autofluorescence and the duration of diabetes mellitus. The corneal fluorescein concentration 45 min after topical application of 20 microliters of 2% sodium fluorescein was also significantly higher in diabetics than in controls (1,373.2 +/- 1,081.5 vs. 363.0 +/- 308.3 ng/ml, p < 0.001). No correlation existed with postprandial blood sugar (r = -0.19, p = 0.056) nor with glycosylated hemoglobin (r = -0.13, p = 0.20). The corneas in diabetics became more hypesthetic with longer duration of diabetes mellitus (r = -0.19, p = 0.02), although the mean corneal sensitivity threshold was not statistically higher in the diabetic group (p = 0.57). There was no correlation of the epithelial barrier function with the duration of diabetes (r = -0.07, p = 0.38), the severity of diabetic retinopathy (r = 0.07, p = 0.38), and the corneal sensitivity threshold (r = -0.06, p = 0.43).

Aged↗
PubMedDate not supplied

Imerslund-Gräsbeck syndrome in two brothers: renal biopsy and ultrastructural findings.

In two Chinese siblings with Imerslund-Gräsbeck syndrome, light microscopy of renal biopsies showed no remarkable change. Ultrastructurally, there were small possible focal defects in the glomerular basement membrane. Neither podocytes nor tubular cells showed evident change. No electron dense deposit was found. Our observations on renal ultrastructure differ from the previous five reports. The literature on renal pathology of this syndrome is reviewed.

Anemia, Megaloblastic↗
PubMedDate not supplied

Reappraisal of K-ras and p53 gene mutations in the recurrence of Dukes' B2 rectal cancer after curative resection.

BACKGROUND/AIMS: Recurrence of rectal cancer remains a major clinical problem. This study was conducted to evaluate the impact of K-ras and p53 mutations on the recurrence of rectal cancer. METHODOLOGY: A total of 166 resected Dukes' B2 stage rectal carcinomas were collected between January 1990 and April 1994. The stored frozen tissues were retrieved for immunocytochemistry of p53 and genomic analysis of K-ras and p53 genes. The data of K-ras and p53 gene mutations were correlated with clinicopathological variables. The concordance of immunocytochemistry with genomic analysis in the survey of p53-mutations was examined. The follow-up data were analyzed by Kaplan-Meier estimator. RESULTS: Sixty-nine patients (41.6%) developed recurrent tumor. A significantly higher recurrence rate (p = 0.0013) and shorter median recurrence time were noted in p53 mutated than non-mutated cancers. Mutations in K-ras gene do not significantly increase the risk of tumor recurrence (p = 0.1702). K-ras and p53 mutations are not associated with clinicopathological parameters (p > 0.05). Kappa statistic indicates highly significant reproducibility between immunocytochemistry and genomic analysis for p53 mutations (p < 0.0001). CONCLUSIONS: Presence of p53 mutation significantly increases the recurrence rate and shortens the recurrence time of the resected rectal cancers. Pre-operative routine check for p53 mutations by immunocytochemistry may be beneficial in choosing the optimal surgical strategy for rectal cancer.

Aged↗
PubMedDate not supplied

Clinicopathologic and carcinogenetic appraisal of DNA replication error in sporadic T3N0M0 stage colorectal cancer after curative resection.

BACKGROUND/AIMS: DNA replication error (RER) was found to play a role in the carcinogenesis of a subset of sporadic colorectal cancers. This study was conducted to evaluate the clinicopathologic implications of RER in T3N0M0 stage colorectal cancers. To better understand the carcinogenesis of sporadic colorectal cancer, the RER status was further correlated with the alterations of K-ras, p53 and deleted in colorectal cancer (DCC) genes which were frequently involved in the adenoma-carcinoma sequence. METHODOLOGY: Seventy-eight patients with curatively resected T3N0M0 stage sporadic colorectal cancer were accumulated. The stored frozen tissues were retrieved for analyses of 1) microsatellite instability at 7 distinct chromosomal loci, 2) loss of heterozygosity at DCC gene, 3) K-ras gene mutation, 4) p53 expression, and 5) DNA content. The RER status was correlated with various clinicopathologic and molecular genetic factors. The survival of patients stratified by RER status was analyzed by Kaplan-Meier estimator. RESULTS: The RER-positive tumor was detected in 32.1% (25/78) of patients. The RER-positive cancer patients presented with distinct clinicopathologic features including young age of tumor onset, proximal tumor location, mucin production in histology, a higher rate of synchronous and metachronous colorectal cancers, and an increased incidence of extracolonic primary cancer. Patients with RER-positive tumor were found to have an improved prognosis with the 5-year survival probability of 76% and 45% in RER-positive and RER-negative groups, respectively (p < 0.05). The RER-positive tumors tended to have normal p53 expression, DNA diploidy, and a lower DNA index. The rate for the loss of heterozygosity of DCC gene was significantly lower in RER-positive tumors. RER status was not associated with K-ras mutation. CONCLUSIONS: The clinicopathologic features and carcinogenesis of RER-positive sporadic colorectal cancers were considered different from those of RER-negative tumors. The presence of RER may identify a subset of less aggressive tumors with good prognosis in T3N0M0 stage colorectal cancers.

Adenocarcinoma↗