In vivo kinetics of oxidatively modified HDL

The kinetics of oxidatively modified high-density lipoprotein (HDL) in vivo were investigated. 125I-labeled oxidized (Ox) HDL and 131I-labeled native (N) HDL were injected simultaneously into control and WHHL rabbits. The fractional catabolic rates of 125I-labeled Ox-HDL were significantly greater than those of 131I-labeled N-HDL in both control (2.52 +/- 0.36/day vs 0.94 +/- 0.02/day) and WHHL rabbits (4.07/day vs 1.32/day). Oxidized HDL was catabolized faster than native HDL and was taken up primarily by the liver, spleen, and kidney.

The effect of carbohydrate ingestion on performance during a 30-km race

Seven experienced endurance runners completed a 30-km road race on two occasions separated by 10 days. On each occasion the subjects consumed 250 ml of either a 5% carbohydrate (CHO) solution or nonflavored tap water (W) immediately prior to the start of the race, and 150 ml of the assigned fluid every 5 km thereafter. Performance time for the CHO trial was faster compared with the time recorded for the W trial (128.3 +/- 19.9 min vs. 131.2 +/- 18.7 min [p < 0.01] respectively). Running speed was maintained throughout the race in the CHO trial, whereas a decrease in the running speed occurred after 25 km (p < 0.05) in the W trial. No difference was found between the two trials in blood glucose concentration, plasma electrolyte concentrations, body weight loss, change in plasma volume, and rating of perceived exertion. Blood lactate concentration was higher at 25 km during the CHO trial compared with the W trial (p < 0.01), but plasma FFA and glycerol concentrations were lower at 30 km during the CHO trial than during the W trial (p < 0.05). In conclusion, this study shows that performance time for a 30-km road race is improved after ingesting a 5% CHO solution.

Effects of heparin and other glycosaminoglycans on elastin production by cultured neonatal rat lung fibroblasts

Proteoglycans are important structural elements of the extracellular matrix, and may contribute to the dynamic architecture of the lung and also influence pulmonary gas and solute exchange. The potential for proteoglycans and glycosaminoglycans to modulate the synthesis and deposition of elastin, another important extracellular matrix component of the lung, has not been established. Therefore the effects of glycosaminoglycans on the steady-state level of elastin mRNA, the incorporation of [3H]valine into tropoelastin, the distribution of soluble elastin in the medium and cell layer, and insoluble elastin deposition have been examined using cultured neonatal rat lung fibroblasts. Heparin decreases the soluble elastin content of the culture medium while increasing the soluble elastin content of the cell layer. This altered partitioning of soluble elastin is associated with an increase in steady-state elastin mRNA and an increase in the deposition of insoluble elastin in the extracellular matrix. Some of these effects may result from the binding of heparin to soluble elastin at physiological concentrations of NaCl. The galactosamine-containing glycosaminoglycans, chondroitin sulfate and dermatan sulfate, differ from heparin in that they increase the quantity of soluble elastin in the culture medium and decrease the deposition of insoluble elastin in the extracellular matrix. Proteoglycans, which are present in most elastic tissues, may participate in the regulation of elastin synthesis and deposition during periods of new elastin formation.

In vivo conversion of recombinant human proapolipoprotein AI (rh-Met-proapo AI) to apolipoprotein AI in rabbits

In vivo conversion of recombinant human proapolipoprotein AI (rh-Met-proapo AI) from E. coli to apolipoprotein (apo) AI was investigated. rh-Met-proapo AI was labeled with 125I, and then administered intravenously to rabbits. Blood was sampled periodically for 6 days. The plasma decay curves of radioiodinated rt-Met-proapo AI were similar to those of human mature apo AI (fractional catabolic rate (FCR); 1.018 +/- 0.090/day vs. 0.976 1 0.031/day, respectively). In vivo conversion of rh-Met-proapo AI to mature apo AI was examined by autoradiography of the isoelectric focusing (IEF) slab gel, i.e., the HDL fraction from each sampling point was semiquantitatively applied to IEF. It was found that the radioactivity of rh-Met-proapo AI migrated to more acidic isoproteins, the conversion was complete within 24 h, and the FCR of rh-Met-proapo AI was 9.20 +/- 1.34/day. Although the plasma decay curves of both human pro (rh-Met-proapo AI) and mature apo AI were significantly steeper than those of rabbit mature apo AI4 and apo AI5 (FCR; 0.703 +/- 0.027/day and 0.795 +/- 0.031/day, respectively), the conversion rate of human rt-Met-proapo AI to mature apo AI in rabbit was assumed to be 1:1. In vitro incubation of rh-Met-proapo AI with rabbit serum produced mature apo AI isoproteins, as determined by the apo AI immunoblotting method. Prediction of the amino acid sequence at the NH2 terminus of rabbit proapo AI showed that the prosegment consisted of an alpha helix with a high probability of a beta turn at Pro9, which is close to that in humans. Thus, (1) the proteolytic cleavage of proapo AI is an extracellular event, (2) the converting enzyme in rabbits can also process human proapo AI, (3) this converting enzyme does not specifically and directly attack the Gln6-Asp7 bond which links the carboxyl-terminal residue of the hexapeptide to the amino-terminal residue of human mature apo AI. The conformation of proapo AI at the NH2 terminus (alpha helix of the prosegment and a beta turn at Pro9) may have a key role in this cleavage, and (4) the examination of rh-Met-proapo AI in rabbits helps to explain the early events of HDL biogenesis.

Serum lipoprotein (a) levels in maintenance hemodialysis patients

To further understand lipoprotein (a) [Lp(a)] and atherosclerosis, we measured serum Lp(a), lipoprotein, and apolipoprotein levels in 55 patients (males, 24-73 years old) on maintenance hemodialysis, and compared them with those of 82 controls (males, 21-81 years old). The serum Lp(a) levels in patients on maintenance hemodialysis were significantly higher than those of the normal controls, while serum total cholesterol (TC), high-density lipoprotein-cholesterol, (HDL-C), HDL2-C, HDL3-C, apolipoprotein (apo) Al, apo All levels, and lecithin-cholesterol acyltransferase (LCAT) activities were significantly (p < 0.05) reduced in the patient group. The frequency distribution of serum Lp(a) levels in the patients was different from that in the control group, and no prognostic tendency of serum Lp(a) levels was noted by the etiology of renal failure as histologically determined by the renal biopsies. In the patient group, we also found that serum Lp(a) levels negatively correlated with serum triglycerides (TG) and total protein (TP) concentrations (p < 0.05), but no correlation was found between the duration of hemodialysis therapy or patient age and the serum levels of TC, TG, apo B and Lp(a) levels when tested for simple regression. Significant (p < 0.05) positive correlations were also found between TP and serum TG, apo B, and LCAT activities. These opposing tendencies of Lp(a) and serum TG, apo B, when measured against TP concentrations, indicate that serum TP levels may not affect serum lipoprotein and Lp(a) levels in the same direction. These data suggest that hemodialysis or end-stage renal disease itself, rather than hypoproteinemia, may hold the key to high serum Lp(a) levels in hemodialysis patients.

[Experimental study on kidney invigorating and lipid reducing decoction-yishen jiangzhi tang in the treatment of chronic renal failure]

In exploring the effect of treatment of supporting the body resistance on chronic renal failure, a chronic renal failure model of rat was created by gastroperfusion of adenine and evaluation was made on the therapeutic effect of Kidney Invigorating and Lipid Reducing Decoction (KILRD). The mental state and body weight of the treated group have recovered well with polyuria and proteinurea improving, BUN and Creatinine decreasing, which appeared to be superior to the naturally recovered group. Renal pathological examination showed that: although the renal parenchymal damage was not reversed but its compensation was satisfactory with compensatory hypertrophy appearing in unaffected nephron. The dominant reaction in the affected area was polynucleomacrocytosis, foreign body granulamatosis, and interstitial lymphocytic infiltration, the fibrosis was inevident, while the above-mentioned condition in the naturally recovered group was relatively more serious, with fibrosis being observed. It was indicated that KILRD could increase the compensatory capacity and immunity, promote protein synthetization and improve renal function. The study on KILRD proved to be a significant conservative medical treatment for chronic renal failure.

Preclinical studies on the anticancer activity of the somatostatin analog octreotide (SMS 201-995)

The antiproliferative effect of somatostatin-14 and its analog octreotide on in vitro pancreatic and breast tumor cells has led to the suggestion that octreotide may have further oncological indications in addition to gastroenteropancreatic tumors. To extend these in vitro observations, we evaluated the effect of octreotide in rodent models of pancreatic and breast tumors. Octreotide of 5 or 50 micrograms b.i.d. in nude mice bearing solid MiaPaCa pancreatic tumors (subline 21) or ZR-75-1 breast tumors induced significant inhibition of tumor growth from week 2 until the end of treatment at week 5. After 5 weeks the mean volume of ZR-75-1 tumors in animals treated with the 50-micrograms regimen was 48% that of control. Autoradiographic studies showed a high percentage (71%) of ZR-75-1 tumors to be somatostatin receptor-positive. In addition, the growth of ZR-75-1 cells in vitro was significantly inhibited by octreotide. The drug was also tested in a second breast cancer model, DMBA-induced mammary tumors in rats, and continuous administration of 10 micrograms/kg/h over 6 weeks led to an approximately 50% reduction in the number of tumors arising in the rat mammary gland. These data suggest that pancreatic and breast cancer may be among the malignant diseases clinically susceptible to octreotide.

Effects of manidipine and delapril on serum lipids, lipoproteins, and apolipoproteins in patients with mild to moderate essential hypertension: a randomized trial with one-year follow-up

Forty-five patients with mild to moderate essential hypertension were randomly assigned to receive 10 to 40 mg of manidipine HCl or 15 to 60 mg of delapril daily for 12 months. In the manidipine-treated group were 13 women and 5 men (mean age, 48.2 years) and in the delapril-treated group 11 women and 11 men (mean age, 53.7 years). Blood samples were taken at baseline and after 6 and 12 months of treatment and again at 2 months after treatment discontinuation. Significant reductions in blood pressure were observed in both treatment groups. The reduction in diastolic blood pressure was significantly greater in the manidipine-treated patients than in the delapril-treated patients; no significant between-groups differences in systolic blood pressure were noted. Heart rate increased significantly in the manidipine group. No changes in serum levels of total cholesterol, triglycerides, and high-density and low-density lipoprotein cholesterol were noted during or after treatment. In the manidipine group, a small but significant decrease in apolipoprotein (apo) A-I and an increase in lipoprotein(a) were found at 6 months and a significant increase in apo A-II and apo E at 12 months; in the delapril group a significant decrease in apo A-I was found at 6 months. The results indicate that both manidipine and delapril are lipid-neutral antihypertensive drugs, since neither drug greatly affected serum lipid metabolism.

[Application of serum somatomedin C level to assess the disease activity in patients with acromegaly]

Serum SMC level was measured in acromegalic patients with different disease activity. The serum SMC level of 10 untreated and 15 treated patients with active disease was 30.5 +/- 17.6 and 23.8 +/- 16.3 KU/L respectively. These levels were significantly higher than the value 2.7 +/- 2.8 KU/L in 7 patients during remitting state. The serum SMC level correlated with the basal and the nadir GH level and the area under the GH curve in glucose suppression test. The serum SMC levels in 6 patients with prolactinoma, 10 patients with Grave's disease and 8 patients with renal failure were all in normal range, but in 10 patients with liver cirrhosis it was 0.36 +/- 0.39 KU/L, which was significantly lower than the normal value. We concluded that serum SMC level is a good criterion for assessment of disease activity of acromegaly for it does not require a dynamic test and it does not increase in other diseases.

Effects of Chinese herbal drugs on serum lipids, lipoproteins and apolipoproteins in mild to moderate essential hypertensive patients

We investigated the effects of the traditional Chinese herbal drugs, Dai-saiko-to (D) and Saiko-ka-ryukotsuboreito (S) on blood pressure, pulse rates, serum lipids, lipoproteins and apolipoproteins in 30 patients with mild to moderate hypertension in an open, randomised trial. After the drug treatment, BP remained unchanged, but pulse rates declined significantly after 3 months in the S treated group. Serum total cholesterol and triglyceride values did not change, but high density lipoprotein-cholesterol increased significantly (P < 0.05) in both groups. Apo-AI (P < 0.1 in S group) and apo-AII (P < 0.05 in D group, P < 0.1 in S group) tended to increase 3 months after treatment. These data indicate that both of these traditional Chinese medicines have a preferential effect on lipid metabolism with little antihypertensive action.

Antiproliferative effects of the somatostatin analogue octreotide (SMS 201-995) on ZR-75-1 human breast cancer cells in vivo and in vitro

The somatostatin analogue octreotide (SMS 201-995) inhibits secretion and growth of certain tumor cells, and current efforts are directed toward the elucidation of its mode of antiproliferative action. In this study, the effect of octreotide on the growth of ZR-75-1 human breast cancer cells has been characterized in immunodeficient nude mice and in cell culture. These results have been related to the expression of somatostatin receptors in vivo and in vitro. Continuous infusion of 10 micrograms/kg/h of octreotide yielded plasma levels of 5.7 ng/ml and elicited highly significant growth inhibitory effects on solid ZR-75-1 breast tumors in nude mice. After 2 and 4 weeks of treatment, tumor volumes in the octreotide group were 39.1 and 36.7% of those of control animals treated with vehicle, respectively. Autoradiographic studies demonstrated that 8 of 12 ZR-75-1 tumors studied were somatostatin receptor positive. When ZR-75-1 tumor cells were exposed in vitro to nanomolar concentrations of octreotide, a dose-dependent inhibition of cell growth was observed in the presence of 5% fetal calf serum or under serum-free conditions using epidermal growth factor, insulin-like growth factor type I, or insulin as growth stimulus. In parallel receptor-binding experiments, ZR-75-1 cells were shown to express specific high-affinity somatostatin receptors (Kd value = 0.9 nM, Bmax = 6000 sites/cell). From these experiments, we conclude that octreotide is a powerful inhibitor of ZR-75-1 tumor cell growth in nude mice and in culture. This inhibitory action of octreotide and the presence of somatostatin receptors on ZR-75-1 tumor cells in vitro and in vivo suggest a direct, somatostatin receptor-mediated effect of octreotide.

Preclinical studies on the anticancer activity of the somatostatin analogue octreotide (SMS 201-995)

The antiproliferative effect of somatostatin-14 and its analogue, octreotide, on in vitro pancreatic and breast tumor cells has led to the suggestion that octreotide may have further oncological indications in addition to its use in the treatment of gastroentero-pancreatic (GEP) tumors. To extend these in vitro observations, we evaluated the effect of octreotide in rodent models of pancreatic and breast tumors. Octreotide at a dose of 5 micrograms or 50 micrograms twice a day in nude mice bearing solid MiaPaCa pancreatic tumors (subline 21) or ZR-75-1 breast tumors induced a significant inhibition of tumor growth from week 2 until the end of treatment at week 5. After 5 weeks, the mean volume of ZR-75-1 tumors in animals treated with the 50-micrograms regimen was 48% of that in controls. Autoradiographic studies showed that a high percentage (71%) of ZR-75-1 tumors were somatostatin receptor-positive. In addition, the growth of ZR-75-1 cells in vitro was significantly inhibited by octreotide. The drug was also tested in a second breast cancer model, 7,12-dimethylbenzanthracene (DMBA)-induced mammary tumors in rats, and continuous administration of 10 micrograms/kg/h over 6 weeks led to an approximate 50% reduction in the number of tumors arising in the rat mammary gland. These data suggest that pancreatic and breast cancer may be among the malignant diseases clinically susceptible to octreotide.

[The incidence of low birth weight infant in north China]

From September 1989 to August 1990, the incidence of low birth weight (LBW) infant was studied collaboratively in 8 areas in north China. 29,941 infants (14,003 males and 12,938 females) were investigated, 1,348 LBW infants included those of preterm and small for gestational age (SGA) term. The incidence of LBW infant was 5.00%. The incidence of male preterm (3.15%) was higher than that of female preterm (2.39%). The incidence of female SGA term (2.46%) was higher than that of male SGA term (1.82%). 52.09% of the infants with birth weight (BW) < 2,500g was of SGA term. 35-36 weeks premature infants accounted for 61.78% and 1,500-2,499g LBW infants for 93.28%. The incidence of SGA preterm (GA < 37 weeks) was 17.8%. In this study, the incidence of LBW infant was higher in Changchun and Huhehot than in other areas.

[Entrainment phenomenon of atrioventricular nodal reentrant and atrioventricular reentrant tachycardias]

Atrioventricular nodal reentrant tachycardia (AVNRT) and atrioventricular reentrant tachycardia (AVRT) were induced by esophageal pacing and their entrainment zones were examined in 20 patients. The results showed that the entrainment phenomenon, which was a common electrophysiological phenomenon in reentrant tachycardia, occurred during overdrive pacing in 19 cases (19/20). The entrainment zone was 10-70 (30.50 +/- 20.85, mean +/- s) ms. The tachycardias could not be interrupted by pacing within the entrainment zone, but they were terminated by burst pacing, with starting pacing cycle length shorter than the shortest entrainment cycle length.

[A new method of expanding free skin grafts]

The harvested skin was processed by a skin-cutting-machine into strips of 0.3 or 0.5 cm in width. Then, the skin strips were glued on alternate folds of a pleated sheet of paper, each fold of which was 0.3 cm or 0.5 cm in width. The paper with skin strips on it was spread flat and cut across into 0.3 cm or 0.5 cm strips. These strips were again glued to another sheet of plicate paper. After being cut across again, many small blocks of skin in equidistance were finally obtained. They were then grafted on the recipient site. The area of grafted wound was four fold or more of the original area of the harvested skin. This method has been used in 6 patients with good result.

Prevalence of growth hormone deficiency of children in Beijing

103,753 (male 51,994, female 51,759) primary and middle school students aged 6-15 years in two districts in Beijing city were surveyed from October 1987 to April 1989. The heights of the students were measured. According to the height standard of northern cities in China, 202 students with heights below the 3rd percentile for age were requested for detailed history, physical examination, screening GH test bone age, T4, SGPT, chest X-ray, routine urine test and sex chromatin (in female). If GH less than 10 micrograms/L, two provocative tests (L-dopa or clonidine and insulin hypoglycaemia test) were done. Then the heights of the short students were observed for 1/2-2 years. GHD was diagnosed in 12 cases based on the GH peak levels less than 10 micrograms/L in two provocative tests, whose growth velocity was slower than that for students of the same age and sex. Of these subjects with GHD, total GHD (GH less than 5 micrograms/L) was present in 7 and partial GHD (GH = 5-9.9 micrograms/L) in 5. The 12 GHD students (male 9, female 3) aged 8.9-15.7 years accounted for 1/8,646 in the total surveyed students. The male and female GHD accounted for 1/5,777 and 1/17,253 in the total males and females respectively.

[The characterization of mutant No. 68 from midecamycin producing strain S. mycarofaciens 1748]

A stable mutant No. 68 was obtained by treatment of S. mycarofaciens 1748 spores at high temperature. The electromicroscopic examination has shown that the mutant No. 68 and parent strain 1748 both have the spore chains of the spiratype. The spores of both strain are cylindrical in shape. The only difference is that the spores of the mutant No. 68 are of smooth surface, but the 1748 are of thorny. The physiological characteristics of both strains are also very similar with slight differences in utilization of few carbon sources and in cultural characters in few medium. Feeding experiment has shown that the mutant No. 68 was blocked in the formation of the macrolide lactone in the midecamycin biosynthetic pathway. This suggested that the mutant No. 68 might be a polyketide synthase genes deficient mutant. The ability of the mutant No. 68 to convert spiramycin into 4"-propionylspiramycin indicated that the mutant No. 68 contained the midecamycin 4"-propionyltransferase and could be used for microbial bioconversion of spiramycin into 4"-propionylspiramycin.