[The enhancing effect of calcium ionophore A23187 on the accessory function of mouse dendritic cells]

In this paper, the immunoregulatory effects of calcium ionophore A23187 on the accessory function of mouse spleen dendritic cells (DC) in primary mixed lymphocyte reaction (1.MLR) and oxidative mitogenesis are reported. A23187 had a direct enhancing effect on DC. When pretreated with 0.5-1 mumol/L A23187 for 6-8 h, the accessory activity of DC was twice as high as that of the control. This is circumstantial evidence indicating an up-regulation of activity mediated by an increase in intracellular Ca2+ levels and PKC activation.

1291 cases of cholelithiasis treated with electric shock on otoacupoints

Since 1985, the authors began to use electric shock on otoacupoints of varying electric resistance for the treatment of cholelithiasis. The instrument used was the Channel Therapeutic Instrument made in China, and the otoacupoints of varying electric resistance were Sympathetic, Pancreas--Gall Bladder, Stomach, Liver, Sanjiao, Endocrine, and Ermigen. In the 1291 cases treated, the total effective rate was 99.69%, the rate of calculus excretion was 91.32%, and the rate of total excretion was 19.51%. The composition of the calculi was cholesterol crystals (31.25%), bilirubin crystals (28.17%), and mixed crystals (40.58%). The largest calculus excreted was an extrahepatic biliary duct calculus of 1.75 cm X 1.5 cm; the largest number of calculi excreted was 152 cholecystic stones 0.3 cm X 0.5 cm in size. In 100 random cases, the biliary system was shown to manifest vigorous dilations and constrictions under Ultrasonic B-scan when the relevant otoacupoints were stimulated with electric shock. Among the 78 control cases, no cholecystic stones were excreted, inspite of the Magnesium Sulfate, Folium Cassiae and fatty meals administered to many cases with constipation.

Water diffusion in a basaltic melt

Water is the most abundant volatile component in terrestrial basalts and is a significant constituent of the gases that escape from basaltic magmas. Knowledge of the diffusivity of water (and other volatiles) in basaltic melts is important for understanding the degassing of basaltic magma and for assessing the fractionation of volatiles during degassing. We report here measurements of water diffusivity in a basaltic liquid. The water concentration profiles through the samples, determined by Fourier-transform infrared spectroscopy, cannot be modelled adequately on the basis of a constant water diffusivity, but instead can be fitted by assuming that only molecular H2O is diffusing and that there is a local equilibrium between H2O molecules and OH groups. The concentration-dependent total water diffusivities in the basaltic melt at 1,300-1,500 degrees C are 30-50 times as large as those in rhyolitic melts, and are greater than the total CO2 diffusivity in basaltic melts, contrary to previous expectations. These results suggest that diffusive fractionation would increase the ratio of water to carbon dioxide in growing bubbles relative to equilibrium partitioning, and decrease the ratio in interface melts near an advancing anhydrous phenocryst.

CT-guided stereotactic evacuation of hypertensive intracerebral hematoma

From January 1986 to June 1989, the CT-guided stereotactic evacuation was performed in 38 cases of hypertensive intracerebral hematoma with satisfactory result. 24 patients were male and 14 female. The age ranged from 37 to 78 years, with an average of 55. 24 cases had their hematoma in internal capsule, 7 in cerebellum, 5 in subcortex, and 2 in brain stem. The interval between the occurrence of hemorrhage and evacuation of hematoma was 24 hours or less in 18 cases, 2-3 days in 14 and 4-7 days in 6. The volume of hematoma was estimated by CT scanning being more than 100 ml in 6 cases whereas much less in 2 cases of the brain stem.

[A two-year prospective survey on nosocomial infections]

A two-year randomized prospective survey on nosocomial infections in hospitalized patients of Hua Shan Hospital from 1985 to 1987 was carried out. Altogether 1,826 patients were enrolled in the study, the incidence of nosocomial infection being 13.1%. The incidence in dermatology ward was the highest (19.8%), then in order of frequency; medical ward 16.5%, surgical ward 14.8%, ward of neurology 13.7%, ward of neurosurgery 12.7% etc. Regarding the location of infection, lower respiratory tract infection was the most frequent (45.2%), followed by urinary tract infection (18%), wound infection (10%), biliary tract infection (7.5%), and bacteremia (5%). Out of 271 nosocomial strains of pathogens, 180 were Gram negative organisms (66.4%), among which P. aeruginosa accounted for 13.3%, K. pneumonia 12.2%, E. coli 8.9%, Acinetobacter sp 7.7%, and Enterobacter sp 7.7%. Gram positive cocci accounted for 22.9%; fungi 10.7%, candida sp. being the commonest. Results of bacterial susceptibility testing showed that the nosocomial strains were more resistant to commonly used antibiotics than the community strains, such as the resistance of E coli to ampicillin, P. aeruginosa to polymyxin B, S. aureus to lincomycin and gentamicin. Multiply factor analysis was done by Logistic regression model in 1,826 hospitalized patients, nine factors being statistically significant. Nosocomial infection is becoming increasingly important, it is imperative to have more intensive epidemiological surveillance data and to take effective control measures.

[Experiment on stability of total flavones in guanshu tablet]

This paper reports the study on the stability of total flavones in guanshu tablet by heating and accelerating method. Taking the total flavone contents of the tablet as the index, the time of validity of guanshu tablet at room temperature 25 degrees C is calculated to be 9.6 years by chemical kinetic analysis.

Antidromic identification of midbrain near response cells projecting to the oculomotor nucleus

Medial rectus motoneurons carry both conjugate and vergence eye position signals. Abducens internuclear neurons, whose axons travel in the medial longitudinal fasciculus, provide these motoneurons with the major signal for conjugate eye movements but not for vergence eye movements. A vergence signal appropriate for these motoneurons is seen on the near response cells that are found in the mesencephalic reticular formation within 2 mm of the oculomotor nucleus. The goal of the present study was to determine if midbrain near response cells project to the medial rectus subdivision of the oculomotor nucleus. Near response cells were recorded in two trained rhesus monkeys with ocular search coils. A stimulating electrode was positioned within the medial rectus subdivision of the oculomotor nucleus. Twenty-eight near response cells were found that could be driven by single pulse microstimulation of the ipsilateral medial rectus subdivision. In all cases, antidromic activation was confirmed by collision testing. Attempts to antidromically activate midbrain near response cells from the contralateral medial rectus subdivision were unsuccessful. Most antidromically activated cells had a steady state firing rate proportional to vergence angle. One cell also showed burst activity during the vergence eye movements. Divergence cells were not antidromically activated.

Interaction between radiation and drug damage in mammalian cells. V. DNA damage and repair induced in LZ cells by adriamycin and/or radiation

A multi-drug-resistant cell line selected in increasing concentrations of Adriamycin and designated LZ (J. A. Belli, Radiat. Res. 119, 88-100, 1989) is shown to exhibit a survival response characterized by radiation sensitivity and Adriamycin resistance. To determine if this response is due to alterations in either the initial levels of damage induced or the repair of DNA damage, LZ cells and the parental V79 cells were exposed to either radiation or Adriamycin and the damage and repair were measured with alkaline or nondenaturing filter elution. After exposure to radiation, induction and repair of both single-strand and double-strand breaks were equivalent. LZ cells exposed to 100 micrograms/ml Adriamycin for 1 h contained no measurable damage while the same treatment induced breaks and crosslinks in V79 cells. Pretreatment of LZ cells for 1 h with Adriamycin before irradiation did not alter either the initial levels of induced damage or the repair of strand breakage. These results suggest that (1) mechanisms other than differential induction and repair of strand breaks are responsible for the increased radiation sensitivity in LZ, and (2) the lack of Adriamycin-induced DNA damage in LZ is at least partially responsible for the increased cell survival after treatment.

Improved high-pressure liquid chromatographic-fluorometric assay for measurement of adenosine in plasma

A high-pressure liquid chromatographic system using fluorescence detection was characterized for the determination of adenosine levels in plasma from anesthetized cat, rat, dog, mouse, rabbit, and guinea pig. The optimal concentration of chloroacetaldehyde necessary to convert physiological levels of adenosine to its fluorescent derivative 1,N6-ethenoadenosine (ethenoadenosine) was in excess of 220 mM. As little as 0.2 pmol of ethenoadenosine could be measured, and detection was linear up to 200 pmol. Derivatization of adenosine into ethenoadenosine was highly dependent on temperature and time. However, ethenoadenosine showed thermal instability in that levels dropped sharply after 30 min at 100 degrees C, 2 h at 80 degrees C, and 24 h at 55 degrees C. Adenosine nucleotides were extracted from plasma samples with an efficiency of greater than 91% to prevent adenosine formation from ATP and AMP that would have otherwise occurred during the derivatization procedure. Plasma levels (microM) of adenosine in venous blood were 0.31 in dog, 0.54 in cat, 0.71 in guinea pig, 1.03 in mouse, 1.04 in rat, and 1.68 in rabbit. Plasma levels of adenosine in arterial blood were not significantly different from levels in venous blood. This method can be used to measure even very low levels of adenosine without interference from nucleotide breakdown.

[The effects of nifedipine, diltiazem, and Paeonia lactiflora Pall. on atherogenesis in rabbits]

The effects of nifedipine, diltiazem, and Paeonia lactiflora Pall (PLP) on serum lipids. Plasma lipid peroxides (LPO), TXB2, and 6-keto-PGF1 alpha in cholesterol-fed rabbits have been investigated. Oral administration of nifedipine (15 mg/kg.d), diltiazem (30 mg/kg.d), and PLP (5 g/kg.d) caused 60.8%, 45.2%, and 74.2% reduction in the area of atherosclerosis in the aorta respectively. The levels of plasma LPO and TXB2 and the contents of cholesterol, phospholipid, and calcium in the intimal-media of the aorta in the treated groups were significantly lower than those in the cholesterol group, but the level of plasma 6-keto-PGF1 alpha in the treated groups was significantly higher. The appearance of cholesterol-induced TXB2 elevation and 6-keto-PGF1 alpha decrease in the treated groups was delayed. There are positive correlation between plasma TXB2 and the followings: serum lipids, plasma LPO, and the content of calcium in the intimal-media of the aorta, and the percentage of area of lesion in the aorta, while plasma 6-keto-PGF1 alpha showed significantly negative correlation with the above data. TXB2/6-keto-PGF1 alpha was found to be positively correlated with the percentage of lesion area of the aorta. It was shown that Ca2+ metabolism plays an important role in thromboxane, prostaglandin, and LPO metabolism. In conclusion, the inhibition of LPO production and regulation of TXA2-PGI2 balance may be one of the main mechanisms of the antiatherogenic effects of calcium antagonists and PLP.

X-ray absorption fine structure investigation of the zinc transition metal binding site of Zn concanavalin A in solution and in the crystal

We report details on measurements by the X-ray absorption fine structure (XAFS) technique of the conformational changes around the transition metal binding site (S1) of the protein concanavalin A induced by crystallization when that site is occupied by Zn. A change from hexa- to tetracoordination occurs at the S1 site on crystallization when the calcium-binding site (S2) is occupied by a calcium atom. When the S2 site is unoccupied, the Zn is pentacoordinated both in solution and in the crystal. The average distance to the coordination shell increases with coordination number as expected. Conformational changes are detected up to 4.5 A from the Zn, the limit of sensitivity of the XAFS technique. When the Zn is hexacoordinated, the ligands around the Zn, as determined by XAFS, are consistent with the crystal structure determination results of five oxygens and one nitrogen. The atom that is released in the tetracoordinated Zn. decreases to five is an oxygen atom, and, in addition, the nitrogen is released in the tetracoordinated Zn. Thus, when S2 is emptied, the protein gains a ligand about the Zn site in the crystal and loses one in solution. These results provide direct evidence that the protein conformation can be altered by the intermolecular forces of crystallization.

Limitation to the use of the urinary S-/R-mephenytoin ratio in pharmacogenetic studies

The reproducibility of the S-/R-mephenytoin ratio was examined in urines stored at -20 degrees C over 2 years. Large changes in this ratio were observed in some urine samples stored for only a few months under these conditions. The changes observed in the S-/R-mephenytoin ratio are attributed to the decomposition of an acid labile metabolite of S-mephenytoin which is eliminated in the urine. The instability of this metabolite makes it desirable to process urine shortly after its collection in order to avoid inaccurate phenotype assignments based upon the urinary S-/R-mephenytoin ratio. If rapid processing of urines is impractical, additional methods are described for preventing improper phenotype assignment of subjects.

Phorbol myristate acetate and calcium ionophore A23187 modulate the accessory cell function of mouse dendritic cells

Dendritic cells (DC) comprise a small subpopulation of lymphoid cells, with distinct morphologic features, surface phenotypes and a potent accessory function in T cell-dependent immune responses. In the present study, we investigated the in vitro effects of a tumor promoter, phorbol myristate acetate (PMA), and calcium ionophore A23187 on the accessory cell function of mouse spleen DCs in the primary mixed lymphocyte reaction (1 degree MLR) and oxidative mitogenesis (OM). A multi-step purification procedure was used to procure a highly enriched DC population from mouse spleen. The accessory cell activity of the DCs so obtained was much stronger than that of M phi s in both MLR and OM. The effects of PMA, a protein kinase C (PKC) activator, on DC were dose-dependent. If pretreated with 50 ng/ml of PMA for 3 h, DC activity was enhanced by about two-fold; whereas 200 ng/ml decreased DC activity with an inhibition rate of about 50%. However, in the latter situation, a moderate increase in DC activity was seen in the early phase of the response. When pretreated with 0.5-1.0 mumol/L A23187 for 6-8 h, the accessory cell activity of DCs was twice as potent as that of the control, and the enhancing effect was sustained in both MLR and OM. Our results indicate that the function of DCs, a cell type with constitutively high accessory cell activity, can be further promoted by A23187 or a low dose of PMA. This is also circumstantial evidence of an up-regulation of DC activity via PKC activation and/or an increase in cytoplasmic calcium.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of alpha adrenergic blockade during stellate ganglion stimulation on arrhythmias induced by acute myocardial ischemia in pigs

The effects of alpha-adrenergic receptor blockade during stellate ganglion stimulation on arrhythmias induced by repeated coronary artery occlusion in pigs under spontaneous breathing were studied. Prazosin, alpha 1-receptor blocker, did not have any effect on the early ischemic dysrhythmia. Yohimbine, which selectively blocks alpha 2-receptor, significantly increased the number of premature ventricular complexes (19 +/- 3----32 +/- 2 PVC; P less than 0.01), but produced no effects on the percentage of appearance of ventricular fibrillation (VF) and ventricular tachycardia (VT). However, nonselective alpha-receptor blocker phentolamine significantly reduced the number of premature ventricular complexes (30.5 +/- 4.5----11 +/- 3 PVC; P less than 0.05), but did not affect the frequency of occurrence of VF and VT. The above results show that alpha-adrenergic mechanisms do not play any important role in the genesis of arrhythmias during ischemia in the pig model.

The effects of perfusion of lateral ventricle with CaCl2 on the febrile response and cAMP content in plasma and cerebrospinal fluid during LP-induced fever

Artificial cerebrospinal fluid (c.s.f.) containing 40 mmol/L excess calcium was perfused through the lateral ventricles of New Zealand white rabbits in order to reduce the Na+/Ca++ ratio in the brain and the effects on both the febrile response and adenosine cyclic monophosphate (cAMP) concentration in plasma and c.s.f. during leucocytic pyrogen (LP)-induced fever were observed. The results showed that cAMP concentration in c.s.f. increased significantly during LP-induced fever while the cAMP level in Plasma remained unchanged, and the perfusion of artificial c.s.f. containing 40 mmol/L excess calcium can significantly inhibit not only the febrile response but also the increase in c.s.f. cAMP level, while there appears no effect on plasma cAMP concentration, thus demonstrating that the increase of Na+/Ca++ ratio causing the increase of cAMP content in the brain may be an essential link in the pathogenesis of LP-induced fever.

Endothelin-1 stimulates the release of arachidonic acid and prostaglandins in rabbit iris sphincter smooth muscle: activation of phospholipase A2

We have investigated the effects of endothelin-1 (ET1) on phospholipid hydrolysis and 3H-arachidonic acid (AA) release and prostaglandin synthesis in the rabbit iris sphincter smooth muscle. ET1 actions are concentration- and time dependent with an EC50 for AA release of 1 nM and t1/2 value of 1.5 min. We have identified the AA metabolites released by ET1, employing HPLC, as both cyclooxygenase and lipoxygenase products. The AA released by ET1 appears to derive mainly from the phosphoinositides through phospholipase A2, rather than phospholipase C activation. A key role for phospholipase A2 in AA release in the sphincter muscle is supported by the following observations. (1) Pretreatment of the labeled sphincter with the phorbol ester, PDBu (100 nM) inhibited ET1-stimulated IP3 formation, but it potentiated ET1-stimulated AA release. (2) Pretreatment of the labeled tissue with isoproterenol (5 M) inhibited ET1-stimulated IP3 production without altering AA release. (3) The potency for ET1-stimulated AA release (EC50 = 1 nM) was much higher than that for IP3 formation (EC50 = 45 nM). (4) There were considerable increases, rather than decreases, in 1, 2-diacyl-glycerol formation (1.2-folds) and its phosphorylated product, phosphatidic acid (2.6-folds) by ET1. It is concluded that in the rabbit iris sphincter ET1 is a potent agonist for AA release and eicosanoid synthesis and that AA is released from phosphoinositides mainly through activation of phospholipase A2.

Characterization of prominent protein antigens from mycobacteria

Detailed analysis of mycobacterial proteins originally identified by their prominent interaction with the host immune system reveals a number of interesting biochemical characteristics. M. tuberculosis antigens with molecular weights of 71, 65 and 12 kilodaltons (kD) belong to highly conserved heat shock protein families. A group of closely related antigens with molecular weights around 30 kD are major secreted antigens which share the ability to bind to fibronectin. Antigens with molecular weights of 38 kD and 19 kD are probably lipoproteins with a role in nutrient transport, while the 23 kD antigen is the superoxide dismutase enzyme of M. tuberculosis. It is anticipated that further studies along these lines will generate information of importance to the understanding of the lifestyle of mycobacteria in vivo and also to the elucidation of immune mechanisms in mycobacterial disease.

Acquired resistance of Nocardia brasiliensis to clavulanic acid related to a change in beta-lactamase following therapy with amoxicillin-clavulanic acid

Previous studies have demonstrated that Nocardia brasiliensis is susceptible to amoxicillin-clavulanic acid and that its beta-lactamases are inhibited in vitro by clavulanic acid. A cardiac transplant patient with disseminated infection caused by N. brasiliensis was treated with this drug combination with good response, but relapsed while still on therapy. The relapse isolate was found to be identical to the initial isolate by using genomic DNA restriction fragment patterns obtained by pulsed field gel electrophoresis, but it was resistant to amoxicillin-clavulanic acid. On isoelectric focusing, the beta-lactamase from the relapse isolate exhibited a shift in the isoelectric point (pI) of its major band from 5.10 to 5.04 compared with the enzyme from the pretreatment isolate. As determined by using values of the amount of beta-lactamase inhibitor necessary to give 50 +/- 5% inhibition of beta-lactamase-mediated hydrolysis of 50 microM nitrocefin, the beta-lactamase of the relapse isolate was also 200-fold more resistant than the enzyme from the pretreatment isolate to clavulanic acid and was more resistant to sulbactam, tazobactam, cloxacillin, and imipenem. The beta-lactamase of the relapse isolate exhibited a 10-fold decrease in hydrolytic activity for cephaloridine and other hydrolyzable cephalosporins compared with that for nitrocefin. Acquired resistance to amoxicillin-clavulanic acid in this isolate of N. brasiliensis appears to have resulted from a mutational change affecting the inhibitor and active site(s) in the beta-lactamase.