Biomedical subjects
Publications and source records attributed to R Lin.
Diagnostic fibre optic endoscopy has a well established role in clinical gastroenterology. The authors highlight the expanding therapeutic applications of this technology.
This is an exploratory study of the nature, course and rates of delayed post-traumatic stress disorder (PTSD). We reviewed 150 medical files of Israeli soldiers who sought help between 6 months and 5 years after the 1982 Lebanon War. Results indicated that only 10% of the cases were truly examples of delayed PTSD; in a large proportion of the cases, help-seeking rather than onset was delayed.
In this study, we have constructed synthetic peptides which are identical to hyperacetylated amino termini of two Tetrahymena core histones (tetra-acetylated H4 and penta-acetylated hv1) and used them to generate polyclonal antibodies specific for acetylated forms (mono-, di-, tri-, etc.) of these histones. Neither of these antisera recognizes histone that is unacetylated. Immunoblotting analyses demonstrate that both transcription-related and deposition-related acetate groups on H4 are recognized by both antisera. In addition, the antiserum raised against penta-acetylated hv1 also recognizes acetylated forms of this variant. Immunofluorescent analyses with both antisera demonstrate that, as expected, histone acetylation is specific to macronuclei (or new macronuclei) at all stages of the life cycle except when micronuclei undergo periods of rapid replication and chromatin assembly. During this time micronuclear staining is also detected. Our results also suggest that transcription-related acetylation begins selectively in new macronuclei immediately after the second postzygotic division. Acetylated histone is not observed in new micronuclei during stages corresponding to anlagen development and, therefore, histone acetylation can be distributed asymmetrically in development. Equally striking is the rapid turnover of acetylated histone in parental macronuclei during the time of their inactivation and elimination from the cell. Taken together, these data lend strong support to the idea that modulation of histone acetylation plays an important role in gene activation and in chromatin assembly.
Long-chain free fatty acids (FFAs) in pulmonary bronchoalveolar lavage fluid (BALF) are antimicrobial agents that may participate in lung defenses. FFAs may also participate in synthetic and metabolic activities of bronchoalveolar lining cells. In evaluating the origins of FFAs, we found that rat triglyceride lipase activity was readily detectable in rat BALF. This activity appeared to be caused mainly by lipoprotein lipase (LPL), because it was inhibited by protamine, a high salt concentration, or specific anti-LPL antibody. LPL activity was detected in BALF from guinea pigs, humans, and rabbits, but rats had significantly more LPL activity than the other species. LPL activity in rat BALF was enhanced by heat-inactivated serum, but LPL-mediated hydrolysis of triglycerides in BALF proceeded at 37 degrees C in vitro even without serum. The possibility that BALF contained an intrinsic LPL activating factor(s) was suggested by the fact that concentrated, heat-inactivated lavage was 85% as effective as heat-inactivated serum in enhancing the LPL activity of fresh BALF. Macrophages are the likely source of LPL in BALF, and we confirmed that rat resident alveolar macrophages produce LPL in culture in a time-dependent fashion. It was concluded that FFAs in BALF were produced by the hydrolysis of triglycerides by LPL.
The effect of the prostaglandin synthesis inhibitor diclofenac sodium (Voltaren) on spermatogenesis in infertile oligospermic patients has been studied. Diclofenac sodium was given orally at a daily dose of 100 mg for 30 days. Seminal fluid parameters were evaluated. Group II with high levels of seminal prostaglandin showed a statistically significant increase in the number and motility of spermatozoa (p less than 0.01), whilst no significant variations were observed in patients of group I with normal values of seminal prostaglandin.
The activity of the caudal neurosecretory system including its neurohemal organ, the urophysis, was assessed in six populations of brook trout (Salvelinus fontinalis)--three from acidified lakes and three from nonacidified lakes (Laurentides Parc, Québec). The acidified lakes were characterized by low pH (mean annual value around 5.5), poor buffering capacity and low conductivity. The activity of the caudal neurosecretory cells was evaluated by morphometry (cell and nuclear sizes). The urophysial content of the neuropeptide urotensin II was measured by isolated trout rectum bioassay. Fish from acidified lakes showed markedly larger cell and nuclear sizes and a lower content of urotensin II than fish from nonacidified lakes. An acidified environment appears to stimulate the synthetic activity of caudal neurosecretory neurons and promote release of urotensin II from the urophysis. This modified endocrine activity in brook trout may reflect adjustment to adverse external ionic conditions.
Toxicological findings are described in 16 medical examiner cases directly related to the combination of codeine and glutethimide. The cases described represent a six-month period, July through December 1982, showing the epidemic rate of abuse of this drug combination, most prominent in the Newark, NJ area since the late 1970s. Concentrations of codeine and glutethimide, measured by gas liquid chromatography (GLC), in the blood averaged 0.62 and 4.07 mg/L, respectively. Similarly determined urine concentrations averaged 38.06 and 12.68 mg/L, respectively. Specific concentrations of each drug in most cases were in the high therapeutic range, suggesting a possible toxic synergistic effect.
Polymorphonuclear leukocyte chemiluminescence and chemotaxis assays were performed on cells obtained from normal individuals and patients with defined defects in chemotaxis or chemiluminescence. After in-vitro pre-incubation with trimethoprim/sulphamethoxazole, its separate components, clindamycin and cefotaxime, normal cells showed some enhancement in chemotaxis and significant increase in chemiluminescence. There was an even more marked increase in chemotaxis when these antibiotics were incubated with cells from patients with leukocyte chemotaxic defects. When the cells from patients with chemiluminescence defects were pre-incubated with these antibiotics, there was also substantial enhancement in chemiluminescence.
Carpal tunnel syndrome is a result of median nerve compression within the carpal canal. Factors associated with the appearance of carpal tunnel syndrome can be related to the bony architecture of the carpal canal, to its contents and to systemic disease. The purpose of this work is to see if changes in the elasticity of the transverse carpal ligament may cause carpal tunnel syndrome.
The efficacy of concomitant lumbar sympathectomy in improving results of aortoiliac reconstruction was assessed by a prospective, randomized study of 51 patients undergoing operation for occlusive or aneurysmal disease. Sympathectomy was performed on 50 limbs, while 52 extremities served as controls. Sympathectomy resulted in a significant reduction in foot vascular resistance determined by plethysmography. However, the procedure had no effect on leg circulation, assessed by ankle/arm pressure indices determined by Doppler ultrasound. In the sympathectomy group, there were three early postoperative amputations for ischemia, despite patent grafts. In the control group, there was one late graft occlusion, caused by progressive atherosclerotic disease. Although sympathectomy may improve pedal circulation, the procedure does not appear to improve the results of aortoiliac reconstruction.
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HIV infection leads to the progressive loss of CD4+ T cells and the near complete destruction of the immune system in the majority of infected individuals. High levels of viral gene expression and replication result in part from the activation of NF-kappaB transcription factors, which in addition to orchestrating the host inflammatory response also activate the HIV-1 long terminal repeat. NF-kappaB induces the expression of numerous cytokine, chemokine, growth factor and immunoregulatory genes, many of which promote HIV-1 replication. Thus, NF-kappaB activation represents a double edged sword in HIV-1 infected cells, since stimuli that induce an NF-kappaB mediated immune response will also lead to enhanced HIV-1 transcription. NF-kappaB has also been implicated in apoptotic signaling, protecting cells from programmed cell death under most circumstances and accelerating apoptosis in others. Therefore, activation of NF-kappaB can impact upon HIV-1 replication and pathogenesis at many levels, making the relationship between HIV-1 expression and NF-kappaB activation multi-faceted. This review will attempt to analyse the many faces and functions of NF-kappaB in the HIV-1 lifecycle.
First generation serologic tests (ELISA-1) for hepatitis C virus infection measure antibodies directed against a short non-structural segment of the virus (anti-c100-3). A major disadvantage of this test is that it lacks sensitivity in the identification of hepatitis C virus among patients at risk of infection. Thus, only 70-90% of chronic non-A, non-B cases are ELISA-1 positive. The present study set out to determine whether antibodies directed against the core region would be a more sensitive indicator of hepatitis C virus infection in patients with chronic non-A, non-B hepatitis. Sera were studied from 97 patients with raised serum alanine aminotransferase levels for more than 6 months in whom other causes of abnormal alanine aminotransferase were excluded. Using ELISA-1, 85 sera (87%) were anti-c100-3 positive. Sera were then tested for presence of antibody directed against Po, a core peptide of a Japanese strain of hepatitis C virus, using an ELISA method. Eighty-eight sera (91%) were anti-Po positive. Among the 12 anti-c100-3 negative patients, six were anti-Po positive. A second generation ELISA for anti-HCV (ELISA-2) incorporates a different antibody to the core region (c22-3) in addition to an expanded non-structural region, c200, which consists of c100-3 plus c33c. With these tests, all sera but one were positive, including 11 of 12 ELISA-1 negative and eight of nine anti-Po negative sera.(ABSTRACT TRUNCATED AT 250 WORDS)
OBJECTIVE: To identify and compare the amount of material on physical activity and the management of smoking, hypertension and hypercholesterolaemia in medical journals and magazines frequently read by general practitioners. METHOD: Qualitative study assessing the total number of articles and advertisements to which Australian GPs are exposed in journals and medical magazines they are likely to read. RESULTS: Only 6% of articles about cardiovascular disease (CVD) risk factors in the Medline search and 5% in the medical magazine search discussed exercise prescription or how to start and maintain an exercise program. Most CVD risk factor articles were on the pharmacological treatment of hypertension (42%), followed by hypercholesterolaemia (32%) and smoking cessation (20%). A review of medical magazines found similarly ranked results, and a count of advertisements indicated 67% related to hypertension, 26% to hypercholesterolaemia and 7% to smoking cessation. CONCLUSIONS: GPs are less well informed by the medical media about physical activity than about other traditional CVD risk factors, although the epidemiological evidence for their health benefits is similar. Strategies should be developed to inform doctors about the evidence of benefits from regular moderate physical activity, and for GPs to recommend exercise in most clinical encounters.