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%.     

Essential phospholipids in the treatment of chronic pyelonephritis]

Through TCD test, observation on the blood flow dynamics change before and after treatment with 31 cases of the child cerebral atrophy was made. It is found that scalp therapy is able to speed up the blood flow of part artery, especially increase the even blood flow speed of MCA, ACA obviously (P < 0.05), which preliminary shows the mechanism of scalp therapy for child cerebral atrophy mean while. It is found that scalp therapy also has the function to restrain epilepsy.     

A 90-kD Na(+)-H+ exchanger kinase has increased activity in spontaneously hypertensive rat vascular smooth muscle cells

Increased activity of the Na(+)-H+ exchanger (NHE-1 isoform) has been observed in cells and tissues from hypertensive humans and animals, including the spontaneously hypertensive rat (SHR). No mutation in NHE-1 DNA sequence or alteration in NHE-1 mRNA and protein expression has been demonstrated in hypertension, indicating that alterations in proteins that regulate NHE-1 activity are responsible for increased activity. The recent finding that NHE-1 phosphorylation in SHR vascular smooth muscle cells (VSMCs) was greater than in Wistar-Kyoto rat (WKY) VSMCs suggested that NHE-1 kinases may represent an abnormal regulatory pathway present in hypertension. To define NHE-1 kinases altered in the hypertensive phenotype. We measured NHE-1 kinase activity by an in-gel-kinase assay using a recombinant glutathione S-transferase NHE-1 fusion protein as a substrate. At least 7 NHE-1 kinases (42 to 90 kD) were present in VSMCs. We studied a 90-kD kinase because it was the major NHE-1 kinase and exhibited differences between SHR and WKY. Comparison of 90-kD kinase activity revealed that SHR VSMCs had increased activity in growth-arrested cells and in cells stimulated by angiotensin II (100 nmol/L for 5 minutes). Activation of the 90-kD kinase by angiotensin II was Ca2+ dependent, PKC independent, and partially dependent on the mitogen-activated protein kinase pathway. These findings indicate that increased activity of a 90-kD NHE-1 kinase is a characteristic of SHR VSMCs in culture and suggest that alterations in the 90-kD NHE-1 kinase and/or proteins that regulate its activity may be a pathogenic component in hypertension in the SHR.     

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.