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Biomedical subjects

W Lui

Publications and source records attributed to W Lui.

8 recordsLinked to original sources

A highly aggressive primitive mesenchymal tumor with a translocation (1;19)(q12;q13.2).

Soft tissue sarcomas constitute a heterogeneous group of malignant tumors of mesenchymal origin, the classification of which may present a diagnostic challenge. We present here the cytological, histopathological, immunohistochemical, and cytogenetic findings of an unusual case of a highly aggressive sarcoma. Based on the morphology and the immunohistochemical profile, this primitive tumor and its metastases could not be conclusively classified as any of the defined subtypes of sarcomas, although the findings were suggestive of a variant of rhabdomyosarcoma. Cytogenetic characterization using G-banding, SKY, FISH, and CGH revealed almost identical chromosomal compositions of the primary tumor and the metastasis. The hypertetraploid karyotype was characterized by numerical imbalances as well as by an unbalanced translocation t(1;19)(q12;q13.2), which has not been previously reported.

Amputation, Surgical↗

Effect of anular repair on the healing strength of the intervertebral disc: a sheep model.

STUDY DESIGN: The intervertebral disc, in a sheep model, was used to assess the effect of directly repairing three different anular incisions on the subsequent healing strength of the intervertebral disc. OBJECTIVES: To assess whether directly repairing an anular defect, made at the time of lumbar discectomy, could influence the healing rate and strength of the anulus fibrosus. METHODS: Twenty-four sheep underwent a retroperitoneal approach to five lumbar disc levels. An anular incision, followed by partial discectomy was done at each exposed level. Anular incisions used in this study consisted of 1) a straight transverse slit, 2) a cruciate incision, and 3) a window or box excision. Healing strength was measured at three time intervals: 2 weeks, 4 weeks, and 6 weeks. Each anular incision type was performed on 30 lumbar discs, 10 discs in each time interval. Five discs in each time interval underwent direct repair, and five discs were left unrepaired to heal as controls. The sheep were killed at 2, 4, and 6 weeks after surgery. The lumbar spines were removed en bloc, and the intervertebral discs were subjected to pressure-volume testing to assess the anular strength of repaired versus unrepaired disc injuries at each time interval. RESULTS: Statistical analysis was performed to evaluate the effects of healing time, incision technique, and repair on the pressure-volume characteristics of the involved discs. Pressure-volume testing showed trends of stronger healing for repaired discs, but at no time interval was any significant difference found between repaired and nonrepaired anular strength. Of the nonrepaired discs, the box incision was only 40 to 50% as strong as the slit or cruciate incised discs during early healing. CONCLUSION: Direct repair of anular incisions in the lumbar spine does not significantly alter the healing strength of the intervertebral disc after lumbar discectomy.

Animals↗

Overland heroin trafficking routes and HIV-1 spread in south and south-east Asia.

OBJECTIVES: Burma produces approximately 60% of the world's heroin, Laos is the third leading producer. Recent outbreaks of injecting drug use and HIV-1 in Burma, India, China, and Vietnam have been associated with Burmese and Laotian overland heroin trafficking routes. We analyzed findings from narcotics investigations, molecular epidemiology studies of HIV-1, and epidemiologic and behavioral studies of injecting drug use, to evaluate the roles that the heroin export routes play in the spread of drug use and HIV-1 in south and south-east Asia. METHODS: We reviewed the medical and narcotics literature, the molecular epidemiology of HIV, and did key informant interviews in India, China, and Burma with injecting drug users, drug traffickers, public health staff, and narcotics control personnel. RESULTS: Four recent outbreaks of HIV-1 among injecting drug users appear linked to trafficking routes. Route 1: From Burma's eastern border to China's Yunnan Province, with initial spread of HIV-1 subtype B, and later C. Route 2: Eastern Burma to Yunnan, going north and west, to Xinjiang Province, with B, C, and a B/C recombinant subtype. Route 3: Burma and Laos, through northern Vietnam, to China's Guangxi Province, subtype E. Route 4: Western Burma, across the Burma-India border to Manipur, predominant subtype C, and B and E. CONCLUSIONS: Overland heroin export routes have been associated with dual epidemics of injecting drug use and HIV infection in three Asian countries and along four routes. Molecular epidemiology is useful for mapping heroin routes. Single country narcotics and HIV programs are unlikely to succeed unless the regional narcotic-based economy is addressed.

Acquired Immunodeficiency Syndrome↗

Sex hormone receptors of hemangiomas in children.

OBJECTIVE: To investigate whether or not estrogen receptor and other sex hormone receptors are present in hemangioma tissues of children. METHODS: Fifty-two specimens of hemangiomas were taken from 52 children. The specimens were doubly stained with hematoxylin-eosin and enzyme-linking affinity immunohistochemistry. The prepared tissue slides were observed under the microscope to search for estrogen receptors (ER), progestogen receptors (PR) and androgen receptors (AR) in all the cells. RESULTS: ER, PR and AR were detected in various kinds of hemangiomas. The mean positive cell rate of each sex hormone receptor in different hemangioma tissues revealed no significant distinction in statistics (P > 0.05). CONCLUSIONS: The results suggest that hemangiomas are one of the target tissues of estrogen. Estrogen, ER, PR, and AR may play an important role in the growth and development of hemangiomas.

Adolescent↗

[Fluorescent determination of magnolol by surfaceactive emulsifier].

Fluorescent determination of magnolol has been effected employing the sensitivity- and stability-enhancing action of the non-ionic surfaceactive emulsifier OP. As a result the accuracy of determination is raised by 2 orders of magnitude as compared to that of ultraviolet spectrophotometry.

Biphenyl Compounds↗

Luminal secretion of myo-inositol by the rat epididymis perfused in vitro.

A technique for perfusing the lumen of rat epididymal tubules maintained in vitro showed that [3H]inulin was largely excluded from the lumen of unravelled tubules from the cauda and tubules from the corpus if the connective tissue capsule was removed. The preparation transported [3H]inositol from the bath fluid for 3 h against a concentration gradient in both regions with activity rising (16-29% of bath fluid values) in the cauda and reaching a plateau (18%) in the corpus epididymidis. HPLC showed that radioactivity was solely associated with inositol and its movement to the lumen was reduced by raising inositol in the bath fluid from 50 microM (plasma levels) to 10 mM, but not affected by reducing the glucose concentration in the bath fluid or introducing physiological concentrations of inositol (30 mM) into the lumen. Secretion into the caudal lumen of unlabelled inositol measured by g.l.c. was maintained for 3 h at concentrations (300 microM) greater than those in the bath fluid and was not reduced when glucose or inositol were removed from the bath. In contrast, glucose was only detectable in the lumen when it was present in the bathing medium, reaching 1% of this concentration. Radioactivity appeared in the epididymal lumen reaching a plateau (19% of bath fluid values) in the corpus and cauda when [3H]glucose was added to the bath fluid, but no radiolabelled inositol was found in the lumen. We conclude that epididymal tissue is a major source of secreted inositol.

Animals↗