It has been recently demonstrated that transferrin (TRF) can inhibit the functional differentiation of rat granulosa cells, but the mechanism remains unknown. In present experiment, the effect of TRF on the binding of 125I-rFSH to receptors and on the maintenance of FSH receptors in granulosa cells from immature, diethylstilbestrol treated rats were studied. The results show that the physiological range of TRF partially blocked the binding of 125I-rFSH to granulosa cells in a dose-dependent manner. TRF also dose-dependently inhibited the maintenance of FSH receptors in accordance with the reduced production of progesterone and estradiol. In view of the present and our previous investigation, it could be concluded that mechanisms of the inhibitory effect of TRF on the functional differentiation of granulosa cells mainly involve blockade of FSH binding to its receptors and inhibition of FSH receptor maintenance by FSH.

Animals↗

PubMed1992

[The changes in plasma renin angiotensin and arginine vasopressin in pulmonary hypertension rats].

The plasma renin activity (RA), the concentration and the ratio of angiotensin (AI) conversion into angiotensin II (AII), and arginine vasopressin (AVP) level were observed in Wistar rats with pulmonary hypertension (PH) induced by extracardiac left-to-right shunting (LRS), hypobaric hypoxia (HH) and shunting plus HH (SHH). In comparison with normal control rats, RA in LRS and SHH rats showed an increasing trend, although no statistical significance appeared (P > 0.05). No change occurred in HH rats. The concentration and ratio of AI conversion into AII were significantly increased in LRS rats (P < 0.05), but decreased in HH and SHH rats (more markedly in HH rats). AVP increased significantly in LRS rats, and also showed an increasing trend in HH and SHH, but no significance was found (P > 0.05). The action of humoral factors in PH formation was discussed.

Angiotensin I↗

PubMed1992

[Thin layer chromatography and extractive technology of Panax japonicum C.A. Mey. var. major (Burk.) C. Y. Wu et K. M. Feng growing in Qingba Mountain Area].

Chemical components of the root, stem and leaves of Panax japonicum var. major were compared with those of Radix ginseng and Radix notoginseng by TLC. The results showed that the total saponin of the root Panax japonicum var. major was closer to that of Radix ginseng and the total saponin of its stem and leaves was similar to Radix notoginseng. A better extractive technology was obtained after isolating and purifying the whole herb of Panax japonicum var. major by ethyl alcohol at different concentrations. The components were compared by TLC. The results showed that with 60% ethyl alcohol the yield of the total extract was 17.15%.

Alkynes↗

PubMed1992

Urinary ANP, ADH, and electrolyte excretion during saturation-excursion diving to pressures equivalent to 250 and 300 m.

Four male divers were exposed to an environment of 26 and 31 atm abs He-O2 for 2 days. Urine was collected during the day (0700-1900 h) and at night (1900-0700 h) before (predive 1 atm abs air), during, and after (decompression and postdive 1 atm abs air) the exposure. Urine flow increased markedly and was mostly attributable to the urine flow during 1900-0700 h. The secretion of atrial natriuretic polypeptide (ANP) increased only at night during hyperbaria. On the other hand, the secretion of antidiuretic hormone (ADH) was suppressed, but increased during compression and the early phase of hyperbaric exposure before it decreased. Linear regression analysis showed that urinary excretion of ANP was correlated significantly with urine flow (r = 0.88, P less than 0.01) and that excretion of ADH negatively correlated with urine flow (r = -0.61, P less than 0.01). Urinary excretion of Na, Cl, Ca, and Mg increased significantly at night during hyperbaria, whereas there was no consistent change in the excretion of K and P. These results suggest that both stimulated ANP secretion and suppressed ADH secretion correlate with the increase of urine and that nocturia is mostly attributable to stimulated ANP secretion. We observed that urinary excretion of ANP increased significantly as early as during the compression phase, which suggested that ANP plays a decisive role in the early diuresis.

Adult↗

PubMed1991

Linkage of faulty major histocompatibility complex class I to autoimmune diabetes.

Pancreatic islet cells are the targets of an autoimmune response in type I diabetes. In the nonobese diabetic (NOD) mouse model of autoimmune diabetes, expression of major histocompatibility complex (MHC) class I proteins was inversely correlated with diabetes; in this mouse a mutation in the MHC class II-linked gene for the putative MHC class I peptide transporter was also present. Mice deficient in MHC class I expression because they do not produce beta 2-microglobulin also developed late onset autoimmune diabetes. In cells from humans with type I diabetes expression of MHC class I was decreased; subsets of prediabetics categorized as most likely to become hyperglycemic also had low MHC class I. T cell responses to self antigens are faulty in diabetics. In sets of genetically identical twins that are discordant for diabetes, the defect appeared to reside with the antigen presenting cell. Thus, a lack of surface MHC class I protein is associated with autoimmune diabetes; the concomitant defect in antigen presentation may impair the development of self tolerance, which could result in autoimmune disease.

Animals↗

PubMed1991

High-performance liquid chromatography of lipids for the identification of human metabolic disease.

We describe a system for quantitative lipid analysis employing ternary gradient high-performance liquid chromatography with evaporative light scattering detection. This technique was applied to extracts of cultured fibroblasts, cultured lymphocytes, and leukocytes and to liver and spleen biopsy specimens. Separation of nonpolar lipids, glycolipids, phospholipids, and sphingolipids was achieved in a single run. Detection did not depend on the presence of any specific chemical reactions, uv absorption, or fluorescence. The sensitivity of the technique is well below 200 ng for individual lipids, and many individual lipid classes were detected in samples as small as 1 mg of total protein, the yield of a single flask of cultured skin fibroblasts. The characteristic stored lipids cholesterol ester and sphingomyelin were seen in excess in human fibroblast cultures from patients with Wolman's disease and Niemann-Pick disease, respectively. A biopsy spleen sample from a patient with Gaucher's disease showed a large glucosylceramide peak. This system provides a tool for detecting lipids that accumulate in tissues of patients with currently unidentified metabolic storage disorders.

Cells, Cultured↗

PubMed1991

Purification and properties of bilirubin oxidase from Myrothecium verrucaria.

Bilirubin oxidase was purified from a culture filtrate of Myrothecium verrucaria Mv 2, 1089 by DEAE-cellulose and Sephadex G-100 column chromatographies. The purified enzyme had a specific activity of 30 U/mg protein and showed a single band on polyacrylamide gel electrophoresis. Some of the general properties of this bilirubin oxidase were as follows: the optimum pH for the enzyme reaction was 7.5 and the optimum temperature was 50 degrees C. The enzyme was stable at pH ranging from 9.0 to 9.5. The mol wt was calculated to be 61,900-62,700 by SDS-PAGE and gel-filtration technique. The apparent Km value of the bilirubin oxidase was calculated to be 9.4 x 10(-5) mol/L. The enzyme activity was greatly reduced by incubation of bilirubin oxidase with Fe2+, Hg+, NaN3, NH+4, and Zn2+. The enzyme reaction was inhibited in the presence of Ca2+, Hg+, Zn2+, Fe2+, and BSA.

Chromatography↗

PubMed1991

[Chemical constituents of Swertia tetraptera Maxim. var. xinglongensis Ji Ma et R. N. Zhao].

Five natural products were isolated from S. tetraptera var. xinglongensis of which four were proved to be oleanolic acid, 1,3-dihydroxy-4,7-dimethoxyxanthone, 1-hydroxy-2,3,5-trimethoxyxanthone and beta-sitosterol. 1,3-dihydroxy-4,7-dimethoxyxanthone has been obtained for the first time from the genus Swertia.

Drugs, Chinese Herbal↗

PubMed1991

[Bronchoplasty and pulmonary arterioplasty with lobectomy in the treatment of central type lung carcinoma].

From 1982 to 1989, bronchoplasty or segmental bronchoplasty and pulmonary arterioplasty in combination with lobectomy and segmentectomy were performed for 9 patients with central type lung carcinoma. Lobectomy with sleeve excision of the bronchus and the pulmonary artery was done in 3 patients, of which one had bilobectomy plus one segmentectomy with segmental bronchoplasty, lobectomy with wedge excision of the bronchus and the pulmonary artery in 2, lobectomy with wedge excision of the bronchus and sleeve excision of the pulmonary artery in 2, lobectomy with sleeve excision of the bronchus and wedge excision of the pulmonary artery in 1, and regular lobectomy with sleeve excision of the pulmonary artery in 1. Histological examination showed that 5 patients had squamous cell carcinoma, 2 adenocarcinoma, 1 small cell carcinoma, and 1 alveolar cell carcinoma. The postoperative course was uneventful. Follow-up showed that 1 patient lived for more than 5 years, 2 more than 2 years, 1 more than 1 year, and 5 less than 1 year.

Adenocarcinoma↗

PubMed1991

[The diagnosis and treatment of congenital bilateral superior oblique palsy].

13 patients with surgically treated congenital superior oblique palsy are presented. Follow-up ranged at least three months after surgery. Most patients received one operation, three cases required the secondary operation. Clinical symptom, Asymmetrical palsies: anomalous head posturing; hypertropia in primary position. Symmetrical palsies; a right hypertropia in left gaze and left hypertropia in right gaze; a positive Bielschowsky test on tiltion the head toward either shoulder, many cases have "V" pattern. The patients who need operation should usually undergo bilateral surgery. The most patients obtained satisfactory results after surgery.

Adolescent↗

PubMed1991

[Isolation of bilirubin oxidase from Myrothecium verrucaria and the optimum conditions of enzyme production].

A bilirubin oxidase (EC 1.3.3.5) producing strain, Mv 2.1089, was isolated from several strains of Myrothecium verrucaria by dilution method. The optimum conditions of enzyme production were investigated and the results were as follows: the suitable medium was cultured at 25 degrees C on a rotating shaker glucose and peptone, at pH 6.0. The strain was cultured at 25 degrees C on a rotating shaker (150 r/min) for 96 h. Bilirubin oxidase with 0.5-1.5 u/ml was obtained in the culture medium.

Mitosporic Fungi↗

PubMed1991

[A canine trial using transventricular laser channel].

Revascularization of ischemic myocardium by Nd: YAG laser channels was studied in 33 dogs with myocardial infarction. The dogs were separated into epi- and endo-cardial (percutaneous and intraoperative) groups. Laser channels with a diameter of 400 microns were made by 6.7-6.8 watt lasersonics Nd: YAG unit. Then the dogs were killed and core samples of myocardium from the laser area were taken as planned. Evaluation includes pre- and post-operative echocardiography and radionuclide scanning to measure left ventricular (LV) function and regional blood flow. Improved LV function and increased uptake of radionuclides were demonstrated. There was no operative mortality. The histologic evidences of reconstructed myocardial microcirculation and communications with myocardial channels by laser were also reported.

Angioplasty, Laser↗

PubMed1991

Effects of changes in pattern of LHRH pulse on LH secretion by perfused anterior pituitary cells of male rats.

In the present study, a perfusion system of dispersed cells was used to investigate the effects of LHRH pulse amplitude and frequency, and LHRH continuous stimulation on LH secretion by anterior pituitary cells of adult male rats. The results have shown that, in the range of LHRH concentrations from 1 X 10(-10) to 1 X 10(-6) mol/L, the dose-response curve of LH secretion was linear. LHRH pulse frequency generated a biphasic LH response: increasing LHRH pulse frequency increased the basal LH secretion and decreased LH/pulse. When 1 X 10(-9) mol/L or greater LHRH was given at frequencies of 3 pulses/h or higher, it was observed that a maximal LH peak was induced and then the LH release declined progressively to its LH basal level, i.e. LHRH self-priming effect and LH desensitization occurred. Enhancement of amplitude of LHRH pulses could reduce pulse frequency required for priming. Increases in frequency of LHRH pulses with high amplitude would provoke the priming effect more quickly. In addition, continuous perfusion of LHRH with different concentrations could also elicit the LHRH self-priming effect and lH desensitization. LHRH with low concentration (1 X 10(-10) mol/L) would take much longer to evoke a self-priming effect. These results indicate that the LH secretion pattern is dependent on LHRH pulsatile amplitude and frequency, and will help to clarify the kinetics mechanisms by which LH pulses fluctuate in vivo.

Animals↗