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Biomedical subjects

W He

Publications and source records attributed to W He.

At least 199 records · Page 11Linked to original sources
PubMed1994

Full-load expansion technique and preliminary clinical application.

For accelerating the inflation process of soft-tissue expansion, a continuous inflation protocol regarding pain as the criterion of overinflation, the full-load expansion technique, has been introduced. It is carried out by restricting persistently the pressure in the expander near the pain threshold in a state of dynamic equilibrium between the infusing rate and the skin expansion velocity with a simple and practical device. This inflation is neither at a uniform infusion rate nor at a constant filling pressure. Nineteen expanders in 13 patients were inflated following this protocol. Their inflations were fulfilled in 5 to 20 days, depending individually on their anatomic regions, total volumes of infusion, areas of the overlying skin, and patient susceptibilities.

Adult↗
PubMed1994

Whole body and splanchnic leucine, phenylalanine, and glucose kinetics during endotoxemia in humans.

To examine the whole body and splanchnic tissue substrate handling during endotoxemia, an intravenous bolus of endotoxin was given to six healthy volunteers during primed, continuous infusions of [1-13C]leucine, [ring-2H5]phenylalanine, and [6,6-2H2]glucose. Whole body protein breakdown, based on whole body Leu and Phe appearance rates (Ra), increased in response to endotoxin given at time 0 (RaLeu 77 +/- 2 mol.kg-1 x h-1, t = 0 h; 88 +/- 6, t = 4 h; P < 0.05) (RaPhe 39 +/- 2 mol.kg-1 x h-1, t = 0; 46 +/- 3, t = 4 h; P < 0.05). Splanchnic amino acid balance (Bal) increased (BalLeu 7 +/- 4 mol.kg-1 x h-1, t = 0; 21 +/- 5, t = 2 h; P < 0.05) (BalPhe 3 +/- 2 mol.kg-1 x h-1, t = 0; 16 +/- 4, t = 2 h; P < 0.05) and can be accounted for by increased splanchnic uptake (Rd) of Phe and Leu (RdLeu 21 +/- 3 mol.kg-1 x h -1, t = 0; 37 +/- 7, t = 120 min; P < 0.05) (RdPhe 10 +/- 3 mol.kg-1 x h-1, t = 0; 24 +/- 5, t = 120 min; P < 0.05). Splanchnic conversion of Leu to ketoisocaproate increased with endotoxin administration (0.7 +/- 0.6 mol.kg-1 x h-1, t = 0; 8 +/- 3, t = 360 min; P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute-Phase Proteins↗
PubMed1994

Cytokines involved in intrathymic T cell development.

Cytokines play an important role in intrathymic T cell development. Over the past several years, genes of newly discovered cytokines have been cloned, and the respective recombinant proteins have become available for functional studies of T cell development. In this paper we have attempted to review the respective roles of interleukins 1, 2, 4, 6, and 7. Special emphasis was given to interleukin 7 which has been shown to play a key role in early T cell differentiation.

Animals↗
PubMed1994

Assessment of proliferating cell nuclear antigen (PCNA) in breast cancer using anti-PCNA PC10 and 19A2: correlation with 5-bromo-2'-deoxyuridine or tritiated thymidine labeling and flow cytometric analysis.

We compared immunohistochemical staining by two monoclonal antibodies, PC10 and 19A2, to standard methods for cell proliferation, 3H-TdR or BrdU labeling index (S-LI) and S-phase fraction by flow cytometry (S-flow). One hundred thirty-two breast carcinomas were studied retrospectively using formalin fixed, paraffin embedded archival tissues on which S-LI and S-flow had been obtained originally. Percentages of tumor cells positive with PC10 and 19A2 correlated well (r = 0.736, p < 0.0001), although the mean marking index for 19A2 was lower and closer to reference measurements than the mean PC10 index. Correlations between PC10 or 19A2 vs. S-LI, S-flow or DNA ploidy (DNAI) were significant in a group of 64 tumors obtained between 1988 and June 1992, and poor in another group of 68 tumors obtained between 1985 and 1988, suggesting deterioration of stainability with prolonged storage. Discrimination of faint staining from negative nuclei was difficult on PCNA stained sections. Carnoy fixation did not improve results over those fixed with formalin. S-flow and S-LI predicted relapse-free survival, but PCNA indices did not. We conclude that PC10 and 19A2 immunostaining of formalin or Carnoy fixed archival breast cancer tissue correlated with reference measures of proliferation only in cases of short storage periods. Although statistically significant, levels of correlation were too low to use PCNA indices for prognosis.

Antibodies, Monoclonal↗
PubMed1994

Serum hyaluronate in the assessment of liver endothelial cell function after orthotopic liver transplantation in the rat.

This study was designed to evaluate the use of serum hyaluronate as a marker of liver endothelial cell function after liver transplantation. We performed orthotopic liver transplantation in both isogeneic and allogeneic rejector models. After transplantation, hepatocyte function was assessed on the basis of serum ALT and total bilirubin levels, and liver endothelial cell function was judged on the basis of serum hyaluronate levels. Significant increase of hyaluronate in the rejector model, compared with the isogeneic model, was seen before any significant results could be obtained from conventional liver function tests. The impaired metabolism of hyaluronate in the rejector model was observed after intravenous injection of trace amounts of radioactive material. Serial studies demonstrate that the endothelial cell is a more susceptible target for the immune response than the hepatocyte. Serum hyaluronate concentration may be a better indicator in the early assessment of graft function. We also examined serum hyaluronate levels to evaluate cold ischemia-reperfusion injury to the liver endothelial cells in the isogeneic model. At 2 hr after reperfusion, hyaluronate levels in the 6-hr cold ischemia (nonviable allograft) group were significantly higher than in the 1-hr and 3-hr cold ischemia (viable allograft) groups. However, there was little difference between the viable allograft groups. After an intravenous injection of 1 mg/kg hyaluronate, the hyaluronate elimination rate in the 3-hr group was distinctly slower than that in the 1-hr group. These data indicate that the hyaluronate elimination rate may be a more sensitive marker of liver endothelial cell function in viable liver after a short period of ischemia.

Animals↗
PubMed1994

[Effects of guifu dihuang pills extract on rabbit IgG accelerated mouse nephritis induced by nephrotoxic serum].

The effects of Guifu Dihuang Pills extract were observed in rabbit IgG accelerated mouse nephritis model induced by nephrotoxic serum. The results showed that this preparation could increase serum albumin, reduce urine protein, serum urea nitrogen and total cholesterol in serum, and improve the histological lesions in kidneys. The effects of Guifu Dihuang Pills extract in dosages of 0.3g/kg and 1.2g/kg were similar to those of cyclophosphamide 0.015g/kg.

Animals↗
PubMed1993

Micromanipulation of chromosomes in PTK2 cells using laser microsurgery (optical scalpel) in combination with laser-induced optical force (optical tweezers).

An optical scalpel and optical tweezer have been combined to perform intracellular microsurgery and micromanipulation in vivo. When only laser microsurgery was performed on metaphase chromosomes, the dissected sister chromatid fragments drifted off to either the side of the spindle or completely off the spindle. At anaphase the fragments separated and the two arms generally moved to their respective daughter cells. When the chromosome arm was cut during anaphase A and B, the distal chromosome fragment separated from the rest of the chromosome and moved toward the pole, following the proximal chromosome fragment. Distal chromosome fragments laser-dissected during metaphase were held together throughout anaphase using the optical trap. Optical trapping of dissected chromosome fragments during anaphase A and B inhibited movement of the chromosome fragment to its pole. As a result, the trapped chromosome fragments were (1) incorporated into the opposite daughter cell, (2) lost in the cleavage furrow during cytokinesis, or (3) eventually incorporated into the correct daughter cell. These results indicate that optical traps are effective in holding laser-dissected chromosome fragments throughout mitosis. This new tool should be useful for studies on chromosome movement and cell genetics.

Animals↗
PubMed1993

A fluorimetric enzyme assay for the diagnosis of Sanfilippo disease type D (MPS IIID).

4-Methylumbelliferyl-alpha-N-acetylglucosamine 6-sulphate was synthesized and shown to be a substrate for the lysosomal N-acetylglucosamine-6-sulphate sulphatase (GlcNAc-6S sulphatase). Fibroblasts and leukocytes from 3 different Sanfilippo D patients showed < 1% of mean normal GlcNAc-6S sulphatase activity. The enzymatic liberation of the fluorochrome from 4-methyl-umbelliferyl-alpha-N-acetylglucosamine 6-sulphate requires the sequential action of the GlcNAc-6S sulphatase and alpha-N-acetylglucosaminidase. A normal level of alpha-N-acetylglucosaminidase activity was insufficient to complete the hydrolysis of the reaction intermediate 4-methylumbelliferyl-alpha-N-acetylglucosaminide formed by the GlcNAc-6S sulphatase. A second incubation in the presence of excess alpha-N-acetylglucosaminidase is needed to avoid underestimation of the GlcNAc-6S sulphatase activity.

Acetylglucosamine↗
PubMed1993

New cyanocyclines from a cyanide-treated broth of Streptomyces lusitanus.

Organic extracts of Streptomyces lusitanus, the producer of the anticancer antibiotic naphthyridinomycin [1], were found to contain two additional compounds active in an antibiotic screen. As with 1, these reacted with NaCN added at the end of the fermentation. One of the addition products has been named cyanocycline B [3] and is derived from N-desmethylnaphthyridinomycin [4], while the other has been named cyanocycline C [5], and is derived from the hydroquinone 6 of 1. Cyanocycline C is unstable and was characterized after conversion to the dimethyl derivative with CH2N2 in the presence of TFA. The implications of these metabolites for the biosynthesis of 1 are discussed. A third new antibiotic, cyanocycline D [8] was isolated from the cyanide-treated broth and proved to be an artifact in which the oxazolidine ring had been opened by cyanide. The potential relevance of the formation of 8 to the reaction of 1 with DNA is also discussed.

Anti-Bacterial Agents↗
PubMed1993

Differential effects of interleukin-7 and interleukin-2 on T-cell receptor gamma delta-expressing cells within CD4-CD8- postnatal human thymocytes.

Highly purified CD4-8- double-negative (DN) human thymocytes proliferated significantly more in response to interleukin (IL)-7 than to IL-2 in a dose-dependent fashion. Both IL-7 and IL-2 promoted the appearance of T-cell receptor (TCR) gamma delta-expressing cells in single cell suspension culture of DN thymocytes. While IL-7 exerted a vigorous growth-stimulating effect on TCR gamma delta-bearing DN thymocytes, IL-2 preferentially maintained the viability of gamma delta thymocytes without promoting their strong proliferation. In both instances, the major subset of gamma delta thymocytes expressed V delta 1 rather than V delta 2 as a variable delta-chain element on their surface. These results reveal differential effects of IL-7 and IL-2 on TCR gamma delta-bearing human thymocytes and underline the importance of both ILs in the development of DN thymocytes.

CD4-Positive T-Lymphocytes↗
PubMed1993

Dual immunologic property of S-100 protein in normal eyes and eyes with retinoblastoma: a histopathological and immunohistochemical study of 88 cases.

To ascertain the cell types expressing S-100 protein in eyes with retinoblastoma, a follow-up study was made on 88 formalin-fixed and paraffin-embedded retinoblastoma specimens histopathologically and immunohistochemically, using antibodies against S-100 protein. In normal retinas and morphologically normal retinas with retinoblastoma, both astrocytes and ganglion cells were stained positively for S-100 protein. In the retinoblastomas, not only the reactive astrocytes in most cases, but also large tumor cells with large cell bodies, prominent nucleoli and well-differentiated figures were positive for S-100 proteins in 2 cases. These large tumor cells were thought to be neuronal and were called ganglion-like cells because they were morphologically and immunohistochemically compatible with the large ganglion cells in normal retina. The results indicate that in eyes with retinoblastoma, S-100 protein has both neuronal and glial immunologic properties and could have a limited value as a glial marker for the histogenesis study of retinoblastoma.

Astrocytes↗
PubMed1993

Determinants of accrual of women to a large, multicenter clinical trials program of human immunodeficiency virus infection. The AIDS Clinical Trials Group.

To determine factors influencing the enrollment of women in a large multicenter human immunodeficiency virus (HIV) clinical trials program in the United States, we analyzed enrollment and demographic data of the AIDS Clinical Trials Group (ACTG) during the period 1987-90. Women comprised 6.7% of 11,909 ACTG participants enrolled in 1987-90. Women entering ACTG trials were significantly more likely to be white (48.5%) and less likely to have ever used i.v. drugs (22.6%) than U.S. women reported to have AIDS (26.5% were white; 51.0% had ever used i.v. drugs, p < 0.0001). In a multiple logistic regression model, specific attributes of individual trials did not influence enrollment of women with the exception that trials that targeted asymptomatic persons had greater enrollment of women. There was wide variation among research units in the percentage of women enrolled (1.0-37.5%), and evidence of significant regional variation in the ability of units to recruit available women. Units with female principal or coprincipal investigators had more than twice the percentage of female enrollment as units headed by men (10.8 vs. 5.3%, p < 0.001). Enrollment of women in a large HIV clinical trials program was low and appeared to be influenced more by demographic and geographic factors that attributes of specific trials. An apparent positive influence of female leadership on the enrollment of women warrants further study.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Clinicopathologic analysis of 60 cases of basal cell carcinoma.

An analysis of 60 cases of basal cell carcinoma is reported. Among the 60 patients were 29 men and 31 women (1:1.1). Their ages ranged from 22 to 88, with an average of 58.8 years. The courses were from 2 months to more than 20 years, with 50% being less than 5 years. The head and face were the main sites involved. The etiology, clinical appearance, pathologic classification, and clinical therapy of the basaloma are discussed briefly. To minimize the patient's psychological burden, and according to the low rate of metastasis, we suggest that the tumor be designated basaloma or basal cell epithelioma rather than basal cell carcinoma.

Adult↗
PubMed1992

A controlled trial of trimethoprim-sulfamethoxazole or aerosolized pentamidine for secondary prophylaxis of Pneumocystis carinii pneumonia in patients with the acquired immunodeficiency syndrome. AIDS Clinical Trials Group Protocol 021.

BACKGROUND: Pneumocystis carinii pneumonia (PCP) continues to be the most common index diagnosis in the acquired immunodeficiency syndrome (AIDS), but it is not clear which of several available agents is the most effective in preventing a recurrence of PCP. METHODS: We conducted a comparative, open-label trial in 310 adults with AIDS who had recently recovered from an initial episode of PCP and had no treatment-limiting toxic effects of trimethoprim-sulfamethoxazole or pentamidine. All the patients were treated with zidovudine and were randomly assigned to receive either 800 mg of sulfamethoxazole and 160 mg of trimethoprim once daily or 300 mg of aerosolized pentamidine administered every four weeks by jet nebulizer. The participants were followed for a median of 17.4 months. RESULTS: In the trimethoprim-sulfamethoxazole group (n = 154) there were 14 recurrences of PCP, as compared with 36 recurrences (including 1 extrapulmonary recurrence) in the aerosolized-pentamidine group (n = 156). The estimated recurrence rates at 18 months were 11.4 percent with trimethoprim-sulfamethoxazole and 27.6 percent with pentamidine (P < 0.001). The risk of a recurrence (adjusted for initial CD4 cell count) was 3.25 times higher in the pentamidine group (P < 0.001, 95 percent confidence interval, 1.72 to 6.16). There were no significant differences between the groups in survival or in hematologic or hepatic toxicity. Crossovers from trimethoprim-sulfamethoxazole to aerosolized pentamidine were more common than the reverse (27 vs. 4 percent), partly because of the study protocols for the management of leukopenia. There were 19 serious bacterial infections in the trimethoprim-sulfamethoxazole group and 38 in the pentamidine group. The time to a first bacterial infection was significantly greater for those assigned to trimethoprim-sulfamethoxazole (P = 0.017). CONCLUSIONS: In patients with AIDS who are receiving zidovudine, trimethoprim-sulfamethoxazole is more effective than aerosolized pentamidine in conventional doses for the prevention of recurrent pneumocystis infection.

AIDS-Related Opportunistic Infections↗
PubMed1992

A reassessment of histologic classification and an immunohistochemical study of 88 retinoblastomas. A special reference to the advent of bipolar-like cells.

BACKGROUND: Despite perpetual efforts of investigators, the histogenesis of retinoblastoma is still in dispute and histologic classification satisfactorily predictive of prognosis does not seem to be in use. METHODS: The authors studied 88 cases of retinoblastoma clinicopathologically and immunohistochemically, paying special attention to the presence of a "bipolar-like cell" element that would be used as one of the criteria for the diagnosis of differentiated retinoblastoma. RESULTS: Twelve cases of retinoblastoma with the bipolar-like cell element in the absence of rosettes and 41 cases of the tumor with rosettes were classified as differentiated retinoblastomas. The other 35 cases without rosettes or bipolar-like cells were classified as undifferentiated tumors. Tumor cells forming rosettes usually had positive results for synaptophysin and neuron-specific enolase (NSE) and negative results for glial fibrillary acidic protein (GFAP) and S-100 protein; however, undifferentiated cells had negative results for these four antibodies. The bipolar-like cells had positive results for synaptophysin and NSE but negative results for GFAP and S-100 protein. Twelve tumors with bipolar-like cells that lacked rosettes showed no optic nerve invasion, and the patients had a significantly better prognosis (100% 5-year survival rate) than 35 patients with undifferentiated tumors (71% 5-year survival rate) (P < 0.01). CONCLUSIONS: The findings support a neuronal origin of the tumor and indicate that, not only the rosettes symbolizing the photoreceptor differentiation, but also other neuronal elements, such as bipolar-like cells, can be used as criteria for histologic classification of retinoblastoma.

Adolescent↗
PubMed1992

Tumour location influences local cytokine production and host metabolism.

To determine whether the location of tumour growth influences host cytokine and metabolic responses, experimental subcutaneous (SQ) and liver (LIV) tumours were compared in Buffalo rats. An LIV tumour that was only 1 +/- 1% (P < 0.05 versus SQ) of body weight produced similar anorexia, weight loss, acute phase response, and systemic cytokine responses as are SQ tumour that was 10 +/- 2% of body weight. Neither tumour-bearing group had abnormal liver function tests or evidence of obstructive biliary pathology. Tumour necrosis factor (TNF) was detected by western analysis in both tumour as well as histologically normal liver remote from the tumour in the LIV group but not in livers of animals in freely fed and SQ groups. The proximity of the tumour to competent tissue macrophage populations, such as hepatic Kupffer cells, may be sufficient to induce cachexia. Hence, tumour location may be as important as tumour burden in determining the host's response to cancer.

Animals↗
PubMed1992

Tolerance to endotoxin prevents mortality in infected thermal injury: association with attenuated cytokine responses.

Endotoxin, a lipopolysaccharide (LPS), is a bacterial cell wall product instrumental in producing deleterious host responses to infection. This LPS appears to act, in part, by triggering release of endogenous mediators such as cytokines. Repeated exposures to endotoxin produce attenuated responses to this molecule. To examine the mechanisms and biologic consequences of this tolerance to LPS, Wistar rats were subjected to a 14-day course of LPS administration. Tolerance to LPS with regard to anorexia, weight loss, and acute-phase responses was noted. Attenuation of these physiologic responses was accompanied by abrogation of circulating cytokine appearance in response to endotoxin, suggesting that tolerance to LPS is in part due to a decreased production of cytokines. Tolerance to LPS also diminished the response to a subsequent infected thermal injury, as measured by food intake, body weight, fibrinogen levels, and mortality. Thus, clinical conditions involving repeated exposure to LPS may modify the host's responses to subsequent injury. The attenuated responses to injury accompanying the decreased production of cytokines further implicate cytokines in the pathogenesis of injury and disease.

Acute-Phase Reaction↗