[Experimental study on huogu granule in treating aseptic necrosis of femur head]

The pharmacological activities and acute toxicological activities of Huogu Granule (HGG) on the basis of clinical treatment of aseptic necrosis of head of femur were studied. It was observed that medium and high dose of HGG could reduce the inflammatory reaction, inhibit the enhancement of the capillary permeability and decrease the frequency of body twisting obviously in mice. All of these were significantly better than that of normal saline control group (P < 0.05, P < 0.01). It showed that HGG had a noticeable anti-inflammatory and analgesic effect. Also HGG was found to improve the absorption of serum Ca, P and the development of femoral growth in chicken embryo. LD50 could not be determined in acute toxicity test, although the dose of 50g/kg.24hr was about 166.7 times of the dosage used for human adult clinically. It demonstrated that the acute toxicity of HGG is negligible.

The role of monosialoganglioside GM1 in LTP-induction in rat hippocampal slices

The effect of monosialoganglioside GM1 of different doses on the long-term potentiation (LTP) of synaptic transmission has been studied in the CA1 region of rat hippocampal slices, and the possible role that calcium ion and NMDA receptor play has also been investigated. The results reveal that larger magnitude of LTP is induced in hippocampal slices pre-incubated with GM1. The dose-response curve appears in diphase, and the largest magnitude of LTP has been obtained at the GM1 concentration of 50 mg/L in incubation ACSF. Moreover, the magnitude of LTP induced from the slices pre-incubated with GM1 at lower calcium ion concentration is similar to that obtained from the control slices at normal calcium ion concentration. Under higher calcium ion concentration, the enhancing effect of GM1 on LTP seems relatively feeble. After NMDA receptors were blocked, no enhancing effect of GM1 was observed. The mechanism of GM1 action on LTP is discussed.

Gene transplantation: combined antisense inhibition and gene replacement strategies

Optimal gene replacement protocols would include both inhibition of the endogenous gene and overexpression of the preferred (or mutant) gene. We have developed a novel gene transfer method to test whether antisense-resistant genes (designed by deletion of antisense RNA target sequences) can replace the function of endogenous genes. Immunoprecipitation studies demonstrated that inducible anti-fos RNA (antisense directed against the c-fos gene) reduces endogenous c-fos expression by 90%, but did not affect the transfected antisense-resistant mutant c-fos genes. Cell growth studies demonstrated that full-length and minimally truncated c-fos expression vectors could restore serum-induced DNA synthesis but that C-terminally truncated Fos mutants including FBR v-fos could not. Transcriptional studies demonstrate that the endogenous c-fos protein contributes to AP-1 activity and normally suppresses regulated SRE (serum response element) activity. This "gene transplant" method for inhibition of endogenous genes and replacement with preferred genes has implications for gene therapy of hereditary hematologic disorders and for the correction or "repair" of oncogenes or tumor suppressor genes in leukemias and lymphomas.

Equations for InsP3 receptor-mediated [Ca2+]i oscillations derived from a detailed kinetic model: a Hodgkin-Huxley like formalism

The nine-variable De Young-Keizer model (1992) for [Ca2+]i oscillations mediated by InsP3 receptor channels in endoplasmic reticulum (ER) membrane is analyzed and reduced to a two-variable system. The different time scales in the three basic channel gating processes, namely InsP3 regulation, Ca2+ activation, and Ca2+ inactivation, are revealed and characterized. The method of multiple scales is used in solving the equations on a succession of faster time scales and reducing them to a 2D system. The reduced system, (Vcy/fcy) dC/dt = -P1P3Rm3 infinity h3(C-C0)-PL(C-C0)-Jpump(C); dh/dt = (h infinity-h)/tau h, is analogous in form to the Hodgkin-Huxley equations for plasma membrane electrical excitability. [Ca2+]i dynamics in this model thus involve ER membrane-associated excitability. The reduced system has a bifurcation diagram almost identical to that of the original system and retains the most important dynamic features of the latter. The analysis also shows that the reduced system becomes simpler when the different gating processes are more independent from each other, i.e. when the rates for Ca2+ binding at the site associated with one gating process are independent of occupancy at the other two binding sites. Assuming further that binding of InsP3 does not depend on Ca2+ occupancy at the inactivation site, we obtain a "minimal" form yet retain significant ability to reproduce experimental observations.

Calcium oscillations in pituitary gonadotrophs: comparison of experiment and theory

We have developed a mathematical model that describes several aspects of agonist-induced Ca2+ signaling in single pituitary gonadotrophs. Our model is based on fast activation of the inositol 1,4,5-trisphosphate (InsP3) receptor Ca2+ channels at low free cytosolic Ca2+ concentration ([Ca2+]i) and slow inactivation at high [Ca2+]i. Previous work has shown that these gating properties, when combined with a Ca(2+)-ATPase, are sufficient to generate simulated Ca2+ oscillations. The Hodgkin-Huxley-like description we formulate here incorporates these different gating properties explicitly and renders their effects transparent and easy to modulate. We introduce regulatory mechanisms of channel opening which enable the model, both in the absence and in the presence of Ca2+ entry, to give responses to a wide range of agonist doses that are in good agreement with experimental findings, including subthreshold responses, superthreshold oscillations with frequency determined by [InsP3], and nonoscillatory "biphasic" responses followed occasionally by small-amplitude oscillations. A particular added feature of our model, enhanced channel opening by reduced concentration of Ca2+ in the lumen of the endoplasmic reticulum, allows oscillations to continue during pool depletion. The model predicts that ionomycin and thapsigargin can induce oscillations with basal [InsP3] and zero Ca2+ entry, while Ca2+ injection cannot. Responses to specific pairings of sub- or superthreshold stimuli of agonist, ionomycin, and thapsigargin are also correctly predicted. Since this model encompasses a wide range of observed dynamic behaviors within a single framework, based on well-established mechanisms, its relevance should not be restricted to gonadotrophs.

[Defects in insulin binding, internalization and degradation of monocytes from patients with non-insulin-dependent diabetes mellitus]

A14-125I-monoiodoinsulin binding to, internalization into, and degradation inside human circulating monocytes, a cell type widely used for insulin receptor studied, from normal(32) and weight, age-matched NIDDM(31) subject were studied. The specific insulin binding, internalization and degradation were decreased in the cells from NIDDM compared to that in the cells from normal subjects. Scatchard plot analysis of these group data reveal that cells from the normal control subject contain 28,000 receptor sites per cell, while monocytes from the NIDDM patients contain 15,000 sites per cell. These results indicate that the decreased abilities of insulin binding, internalization and degradation of target cells may play a role in the cellular resistance to insulin that occurs in the NIDDM.

[Synchronous and metachronous bilateral testicular germ cell tumors]

Eleven of 605 (1.82%) patients evaluated at this Cancer Hospital for testicular germ cell malignancy between 1958 and 1992 had evidence of bilateral testicular malignancy. The age ranged from 28 to 72 years. Five patients had a history of undescended testes and one of them was surgically corrected at age of 11 years. Four of these were synchronous and seven metachronous. Histologically, all four synchronous tumors were pure seminoma. Two of seven metachronous tumor cases had unilateral testicular non-seminoma. The other 5 patients had pure seminoma. The second tumor was diagnosed between 8 months to 150 months after diagnosis of the first one. Three of 7 (42.9%) patients were diagnosed within 5 years. Two patients with synchronous tumors died within 1 year (3 months and 6 months, respectively). Only one patient with metachronous tumors died of the disease. This study indicates that the overall prognosis and outcome depends on the histologic type and stage of the disease and reemphasizes the low but definite risk for development of a second testicular malignancy.

Relationship between the characteristics of immunopathological expression of hepatitis C virus antigen and hepatocytic injury

Biopsied liver tissues from 352 cases were tested for hepatitis C virus (HCVAg) with improved PAP immunohistologic chemical method. Furthermore, corresponding seroantibody to hepatitis C virus was also tested. The total HCVAg positive rate was 9.1%. The HCVAg positive rate in chronic persistent hepatitis (CPH) was 5%. The HCVAg positive rate in chronic active hepatitis (CAH) was 11.2%. The HCVAg positive rate raised gradually along with the severity of hepatocytic injury. HCVAg may be seen in necrotic liver cells exfoliating into the liver sinus, indicating a close relationship between HCVAg and hepatocytic injury. Expression of HCVAg was mostly of the nucleus type in CPH cases and was mostly of the plasma type in CAH cases. The periphery of nucleus type-expressed positive cells generally had no marked inflammatory cell infiltration. The periphery of plasma type-expressed positive cells had a certain amount of inflammatory cell infiltration. Along with the severity of hepatocytic injury, HCVAg expressed itself in a positive correlation according to the nucleus and plasma types. The HCVAg positive cells were located mostly in the lobular peripheral band and rarely located in the venoperipheral band. It was possible that this had some relation with the lobular microcirculation of blood and blood supply. In this study, there was no obvious correlation between the HCVAg positive rate in hepatic tissues and the anti-HCV positive rate in sera. Neither the patients with HCVAg positive liver tissues nor the patients with seropositive anti-HCV had any history of blood transfusion and the use of blood products.(ABSTRACT TRUNCATED AT 250 WORDS)

Subcellular distribution of Ca2+ release channels underlying Ca2+ waves and oscillations in exocrine pancreas

Agonists trigger Ca2+ waves and oscillations in exocrine gland cells. Our confocal Ca2+ imaging revealed three distinct phases during the Ca2+ waves in the rat pancreatic acinar cell. Rises in Ca2+ concentration were initiated at a small trigger zone, or T zone, in the granular area; then, Ca2+ waves rapidly spread within the area and, at high agonist concentrations, propagated slowly toward the basal pole. Injection of inositol 1,4,5-trisphosphate (IP3) or Ca2+ from patch pipettes demonstrated the presence of high sensitivity IP3 receptors at the T zone, Ca(2+)-induced Ca2+ release channels in the granular area, and low sensitivity IP3 receptors in the basal area. The IP3 receptors at the T zone appeared to generate autonomous Ca2+ spikes and to initiate patterned Ca2+ oscillations. Thus, heterogeneous cytosolic localization of Ca2+ release channels plays a key role in Ca2+ waves and oscillations.

Agonist-induced localized Ca2+ spikes directly triggering exocytotic secretion in exocrine pancreas

We investigated how agonist-induced patterned rises in cytosolic Ca2+ concentration ([Ca2+]i) regulate exocytotic secretion in the rat pancreatic acinar cell. The distribution of [Ca2+]i was visualized with a confocal microscope, which revealed that a Ca2+ ionophore, A23187, induced slow and homogeneous [Ca2+]i rises, while acetylcholine (ACh) always triggered primary Ca2+ spikes at the granular area which bears secretory granules. Secretion was monitored by measuring capacitance with the patch clamp method. Errors in the estimates of membrane capacitance (C) due to changes in conductance (G) were experimentally as well as theoretically evaluated to be one-tenth of the actual signals. We found that A23187 raised G without changing C at a low concentration, while it triggered asynchronous rises in G and C with lags in C, at a high concentration. By contrast, ACh triggered simultaneous rapid rises in G and C. Our results support the hypothesis that exocytotic secretion is less sensitive to Ca2+ than to ion channels and is directly caused by agonist-induced primary Ca2+ spikes at the granular area. It is therefore suggested that spatio-temporal patterns of Ca2+ oscillations could play a key role in exocytotic secretion from the exocrine acinar cell.

[Contraction stimulates incorporation of 3H-leucine and cell growth in cultured neonatal rat ventricular myocytes]

To determine whether contraction could influence cell growth, the rate of protein synthesis (3H-leucine incorporation) and cell diameter and volume were measured in cultured neonatal rat cardiac myocytes beating spontaneously or arrested by high potassium. In medium supplemented with 10% calf serum, the 3H-leucine incorporation for 24 h in contracting myocytes (CMC) was significantly higher by 14.2% than that in quiescent myocytes (QMC), i.e. 1,229 +/- 29 cpm/10(5) cells vs. 1,076 +/- 60 cpm/10(5) cells (P < 0.01, n = 5 for each group). The cell diameter and cell volume in QMC group were respectively 15.14 +/- 0.42 microns and 1,842 +/- 123 microns3, while in the CMC group the corresponding figures reached to 16.82 +/- 0.64 microns3 and 2,495 +/- 210 microns3, increased by 11.1% and 35.5% respectively (P < 0.01, n = 6 for each group). With prolongation of culture time, the differences in these parameters between CMC and QMC became even more significant. In all these experiments, there was no significant difference in cell number between the two groups (P > 0.05). It is concluded that contraction per se can accelerate protein synthesis and cell growth in neonatal rat ventricular myocardium.

[Use of a computer-controlled servo system to produce "ephysiological" contraction of isolated rat papillary muscle]

A computer-controlled servo system consisting of an ergometer with a force-displacement dual mode transducer, a Z-80 single-board microcomputer and a designed software was constructed. This servo system can be used to generate physiological contraction in isolated rat papillary muscle, in which the muscle went through a complete 4-phase cycle of force and length changes, similar to those undergone by muscle fibers in the beating heart during the cardiac cycle. This system is being used to investigate the tension-length relation and the network of isolated myocardium as well as the end-systolic tension-length relation and the force-velocity relation simultaneously.