Low- and high-density lipoproteins as mitogenic factors for vascular smooth muscle cells: individual, additive and synergistic effects

The mitogenic activities of low (LDL)- and high (HDL)-density lipoproteins have been examined in cultures of human vascular smooth muscle cells (VSMC). LDL and HDL3 dose-dependently (EC50 values approximately 50 micrograms/ml) stimulated DNA and protein synthesis ([3H]-thymidine and [3H]-leucine incorporation, respectively) in the absence of exogenously added mitogens. The synthetic responses of VSMC to combinations of LDL and HDL3 were additive, indicating that each lipoprotein mediates discrete effects. LDL or HDL3 promoted VSMC proliferation under strict mitogen-free conditions, but this growth response was not sustained. VSMC exposed to combinations of lipoproteins (either LDL or HDL3) and growth factors (either PDGF-BB, EGF, bFGF or IGF) exhibited synergistic DNA synthesis responses. In the combined presence of PDGF-BB and either LDL or HDL3, VSMC proliferation was sustained. Anionized lipoprotein preparations (oxidized, acetylated, carbamylated or malonimylated) also stimulated DNA and protein synthesis. Since the antioxidant beta-hydroxylated toluene did not block the effect of native LDL on DNA synthesis, and fucoidin, a specific competitor for the 'scavenger' receptor, did not inhibit oxidized LDL-induced DNA synthesis, activation of mitogenic signals by lipoproteins does not depend on lipid peroxidation. Rather, the apparent intrinsic mitogenic potential of lipoproteins may depend upon their direct activation of replication-coupled signal transduction systems.     

Gastric emphysema simulating perforated hollow viscus: case report and review of literature

Gastric emphysema is a benign condition in which air from non bacterial sources accumulate within the wall of the stomach. This pathology is usually associated with gastric and, or small bowel obstruction. A case report of gastric emphysema is presented, together with a pertinent review of the literature.     

Polymorphism of pericentromere heterochromatin of polytene chromosomes of ovarian trophocytes in natural populations of the malaria mosquito Anopheles messeae Fall

The HBsAg status and demographic data of 2480 pregnant women who attended antenatal clinics at Maternal and Child Health Centres in Hong Kong were collected by means of a self-administered questionnaire over a 1-week period in July 1996, to explore the underlying reason of a higher than expected HBsAg prevalence. Local women constituted 49.2% of the sample, mainland Chinese 39.7% and others 11.1%. The overall HBsAg prevalence was 10.0%. When related to place of birth, those born in Hong Kong had a prevalence of 8.4% whereas the prevalence of those born in mainland China was 13.1% (P < 0.001). The overall HBsAg carriage rate is high because of a higher rate in immigrants in the community. It is apparent that the HBsAg prevalence of local people in Hong Kong has been decreasing in the past decade. Overall, the current HBsAg carriage rate in the local adult population is estimated to have declined to about 8%.     

A comparison of the hypolipidemic action of probucol at doses of 500 and 1000 mg/day in moderate hyperlipoproteinemia

AIM: Evaluation of effectiveness of hypolipidemic action of probucol in doses 500 and 1000 mg/day and comparison of probucol blood concentrations on the treatment month 3 and 6. MATERIALS AND METHODS: Probucol (Akrikhin, Russia) was given to 41 patients with primary hypercholesterolemia in a dose 500 mg/day. 3 months later the patients were divided into two groups. Group 1 patients exhibited a > 10% decrease in cholesterol levels and continued to take probucol in the dose 500 mg/day. Group 2 patients were crossed over to higher cholesterol dose--up to 1000 mg/day. Lipids levels were measured by enzyme tests, apoproteins--by immunoturbidimetry and immunodiffusion, probucol concentrations--by high-performance liquid chromatography. RESULTS: After 3 months of treatment, cholesterol lowered by 14.3 and 9.2% in groups 1 and 2, respectively. After 6 months, by 19.7 and 12.9%, respectively. Probucol concentrations in blood were higher after 6 months of treatment than after 3 months in both groups. No significant differences existed between the groups by probucol concentrations in 3 and 6 months. CONCLUSION: Hypolipidemic effect of probucol depended on the individual features of lipoproteins metabolic disorders rather than the drug blood concentration. Larger probucol doses fail to reduce cholesterol further.     

The work of the epidemiological health laboratory of the Black Sea Fleet in World War II

Between October 1983 and December 1991, 14 patients (mean age 48.1 [range 38 to 68] years) presented with single, clear, cystic-appearing juxtafoveal lesions beneath the retina, with discrete borders measuring approximately 2 mm in diameter. All patients had vision of 6/7.5 or better, which did not deteriorate over a follow-up period of 3 to 91 (mean 18.1) months. Angiographically, the lesions showed relative homogeneous hyperfluorescence with very discrete margins, the angiographic appearance of serous retinal pigment epithelial detachment. We describe the clinical and angiographic appearance on presentation and in follow-up and discuss the probable relationship of these lesions to central serous choroidopathy.     

A comparative study of the thermal stability of phenylalanyl tRNA synthetase from Escherichia coli MRE-600 and Thermus thermophilus HB 8

The thermal stability of phenylalanyl-tRNA-synthetase (PTS) from E. coli and T.thermophilus HB 8 was studied in solution at various conditions by scanning microcalorimetry. It has been shown that the value of heating rate, concentration of the enzyme and Mg2+ ions in the solution affects the parameters of thermal denaturation of both enzymes. The higher thermal stability of PTS from T. thermophilus was observed as well as the independence of its properties upon broad variations of experimental conditions. The role of thermostability of the enzymes are discussed with respect to the biological properties of E. coli and T.thermophilus.     

Mullerian-inhibiting substance secretion is delayed in XX sex-reversed dog embryos

A mathematical multiple dosing model was designed so that human plasma concentration-versus-time curves of beta-lactams are reproduced in mouse plasma. The pharmacokinetic parameters of FK037, a new injective cephalosporin, in volunteers and in the mice model were 6,966 and 6,894 ml, respectively, for Vc, 2.592 and 2.698/h for alpha, 0.2875 and 0.3027/h for beta, and 0.9079 and 1.0506 for K21. Therefore, real pharmacokinetics of humans were reproduced in mice by this method. The 8-hour therapeutic efficacy (the decrease of the viable counts in the lung) against pneumonia with Staphylococcus aureus and Pseudomonas aeruginosa in mice was well correlated with the time above MIC value, but not with AUC, Cmax or AUC above MIC. These results indicate that this model was valuable to evaluate the beta-lactam antibiotics for predicting their clinical efficacy and that the time above MIC is an important factor in selecting beta-lactam agents and determining dosage in pulmonary infection.     

The diagnostic and treatment characteristics of focal liver lesions using computed tomography

Under analysis is an experience with examining and treatment of 167 patients with focal lesions of the liver using computed tomography. Percutaneous transhepatic puncture and draining the hepatic abscesses and cysts under control of computed tomography is an independent method of treatment used in 53 patients. The technique of performing the puncture and drainage is described. Specific features of surgical treatment of focal lesions of the liver are described. Decompression of bile ducts in the postoperative period is shown to be necessary. A conclusion is made about high efficiency of computed tomography in diagnosis and treatment of focal lesions of the liver.