Biomedical subjects
Publications and source records attributed to A Chong.
The aim of total hip arthroplasty surgery is to relieve pain. There are many postulated causes of thigh pain following total hip arthroplasty, some of which are not easily corrected. Muscle hernia as a result of hip surgery is a cause of thigh pain that is disabling, relatively easy to diagnose, and may be preventable.
The neuropathic joint is one of the most difficult management problems in orthopaedic practice. The surgeon is often referred the patient late in the course of the disease, when there has been marked joint destruction so that non-operative measures are not suitable. We report a case of a severely deformed neuropathic knee joint, for which an uncemented total knee replacement was performed. The rationale for use of this procedure instead of arthrodesis, and discussion of the condition follow.
More than 50,000 patients were affected in Cuba during an epidemic outbreak of peripheral neuropathy from January 1992 until September 1993. The disease presented as either a retrobulbar optic neuropathy, a predominantly sensory peripheral neuropathy, a dorsolateral myeloneuropathy, or as mixed forms. The morphological findings in sural nerve biopsies from 34 patients with various forms of the disease are presented here. Frozen, paraffin and semi-thin sections were prepared for light and electron microscopy, immunohistochemistry and morphometric analysis. Every case presented morphological alterations ranging from mild axonal dystrophy (9 cases, or 27%) to moderate and severe axonal damage (25 cases, or 73%). In 6 cases (18%), axonal damage was accompanied by perineural fibrosis and vascular abnormalities. Axonal regeneration was noted in 8 cases (23%) and remyelination in 9 (26%). Morphometric analysis showed a predominant loss of myelinated fibers in 92% of the patients. Quantification of myelinated fiber loss in 11 patients revealed a remarkable decrease in large caliber fibers. Scarce mononuclear cells were observed in 17 cases. No virus-like elements were seen. The morphological features found in this study indicate that, regardless of the clinical presentation, peripheral nerve lesions of the epidemic neuropathy in Cuba correspond to an axonal neuropathy. These lesions are compatible with nutritional, toxic, or metabolic etiologies. An inflammatory etiology would be unusual with these lesions.
Explore the source record for details and available documents.
D'Allergen is a recently available acaricidal and allergen reducing agent. To study any beneficial effects of treating houses with this agent in asthmatic children with dust mite allergy, histamine bronchial responsiveness was measured in 18 children before and 6-8 weeks after their homes were treated with the agent. Comparisons were with nine similar asthmatics whose homes were not treated. The mean provocative concentration of histamine causing a 20% fall in forced expiratory volume in 1 s (PC20) increased from 1.02 mg/L to 2.07 mg/L in all 18 children who were studied (1.01 doubling doses). Bronchial responsiveness was relatively unchanged in a well matched control group of nine children studied over comparable time periods (PC20 pre was 1.25 mg/L, PC20 post was 0.67 mg/L). The results suggest that treating homes with D'Allergen reduces bronchial reactivity in asthmatic residents with house dust mite allergy.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Keeping an open mind is often the cornerstone of good management in general practice, especially when treating the elderly as the following cases illustrate.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The brains from 18 cats were examined for the presence of the fibrils and modified PrP protein which are molecular diagnostic markers for scrapie-like diseases. Thirteen cats were referred with clinical neurological signs potentially indicative of feline spongiform encephalopathy (FSE). Of these, five had histopathological changes of FSE, five had other lesions of the central nervous system, and in three the brain was normal. The remaining five cats had no clinical neurological signs and were selected as controls. Fibrils and modified PrP protein were found in the brains of the five cats with FSE and in one of the cats with neurological signs but no histopathological changes in the central nervous system. Fibrils were present in the absence of modified PrP in the brains of two cats, one with neurological signs and a histologically confirmed meningioma, and one with no neurological signs and a histologically normal brain.
Dyskeratosis congenita has been found to be associated with abnormal immune function. In this study we report a patient with this association. He developed Pneumocystis carinii interstitial pneumonia, and impaired cell mediated immunity was confirmed by the presence of depressed lymphoproliferative responses to in vitro stimulation with mitogen. Enumeration of T cell subsets showed a severely depressed CD4:CD8 ratio (0.38), which is the likely cause for impaired cell mediated immunity. The T cell activation pathway appeared intact, as his T lymphocytes were able to express activation markers (CD25 and HLA-DR) after mitogen stimulation.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Incubation of peripheral blood mononuclear cells with interleukin-2 (IL-2) results in the release of a factor which is cytostatic and cytotoxic both to tumor cell lines (A375M, A375P, C480, MCF-7, Hey) and fresh tumor cells (in the human tumor cloning assay), including breast cancer, colon cancer, melanoma, myeloma and ovarian cancer. The factor cannot be detected in a 4-h chromium-release assay, but is best demonstrated after tumor cells have been to it for exposed 3 days. The factor is not cytotoxic to normal peripheral blood leukocytes or normal fibroblasts, and is not toxic to certain targets sensitive to lymphokine-activated killer (LAK) cells, such as K562 and Daudi cells. The factor is diffusible, non-dialyzable, relatively stable to heat and acid and does not contain appreciable amounts of targets resistant to interferon-alpha and beta, tumor necrosis factor beta and interleukin-1. The data suggest that there are several mechanisms of LAK cell activity against tumor cells including one which requires direct interaction of LAK and tumor cells and one which is mediated by LAK cell supernatant. The former is detected by 4-h chromium release while the latter is not.