Selective sensitization by L-glutamate of baroreflex-mediated bradycardia following microinjection into the rostral ventrolateral medulla

This study examined the role of L-glutamate receptors in different sites in the rostral ventrolateral medulla (RVL) on baseline mean arterial pressure (MAP), heart rate (HR), sympathetic efferent discharge (SED) as well as baroreflex control of HR and SED. Depending on the site, the hemodynamic responses varied from an increase to a decrease in MAP which was accompanied by a similar or an opposite change in HR; the change in SED correlated positively with the change in MAP. Because injection of the test dose of glutamate (5 nM) into the deepest portion of the RVL produced the most pronounced increases in MAP, which was accompanied by a brisk bradycardia, we decided to investigate the nature of these responses. Dose-related sympathoexcitatory, pressor and bradycardic effects were obtained in response to 1, 3, 5 and 10 nM glutamate. The glutamate antagonist, glutamate diethylester (GDEE) abolished these responses and decreased baseline MAP, HR and SED. That glutamate-evoked bradycardia was baroreceptor-mediated was supported by: (1) the bradycardia was not only eliminated but was also converted to a small but significant tachycardic response in sinoaortic denervated rats and following cardiac muscarinic blockade; (2) glutamate substantially sensitized the baroreceptor HR and had no effect on SED response when tested by phenylephrine; and (3) GDEE abolished the sensitizing action of glutamate on the baroreflex control of HR. We conclude that glutamatergic pathways in the deepest portion of the RVL are tonically active and subserve sympathoexcitatory, pressor and tachycardic effects. Also, glutamate differentially sensitizes the baroreceptor reflex pathways that control HR by mainly activating the vagal component of the reflex, an effect which masks its tachycardic effect.

[Glycosylated hemoglobin in the diagnosis of diabetes mellitus]

Blood glucose at fasting and 1, 2, and 3 hours after meals GHb (glycosylated hemoglobin) were determined in 66 subjects. Based on WHO criterion, 34 of them were diabetics, and 32 were nondiabetics, in whom impairing of glucose tolerance (IGT) and diabetes were ruled out. The results showed that the concentrations of blood glucose, at fasting, and 1, 2, and 3 hours after meals, blood glucose area, and GHb in diabetic patients were significantly higher than those in the controls. There was a significant positive correlation between GHb and blood glucose at fasting and 2 hours after meal, and between GHb and blood glucose area in all subjects. Relative sensitivity of GHb for detecting diabetes mellitus was 88%, and relative specificity was 93.75%.

[Constituents of the seed coat of Arachis hypogaea L]

From the seed coat of Arachis hypogaea two compounds were isolated. They were identified as the dimer of proanthocyanidin-A type(I) and D-(+)-catechin (II) on the basis of UV, IR, MS, CD, 1H-NMR, 13C-NMR and chemical evidences. It has been found that II is the effective constituent of this plant and I has some active effects as well.

[A simple useful rhinoresistometer: mechanical principle and clinical applications]

A new rhinoresistometer consisting of a pressure nozzle, a flow nozzle, a two-U-tube manometer and a X-Y chart recorder is introduced in this paper. Such an apparatus is simple in construction and easy to use. The expiratory transnasal pressure difference is measured by a U-tube manometer while the nasal airflow is measured by flowmeter. With this apparatus, the subject's nasal airway resistance can be evaluated accurately and the nasal airway resistance curves drawn automatically. The mechanical principle of the apparatus is described and the nasal airway resistances of 200 normal subjects are reported in this article.

Laboratory and clinical diagnosis of human cytomegalovirus infection after transplantation

Urine and blood specimens from 32 recipients of allograft organ transplant were investigated for human cytomegalovirus (HCMV) by conventional cell culture, indirect immunofluorescent assay subsequent to the rapid cell culture and DNA-DNA hybridization. The results showed that the rapid cell culture technique might be the best method for rapid detection of active HCMV infection after transplantation because it possesses the advantages of simplicity, speediness, sensitiveness, and high reliability of detecting productive HCMV infection. The major symptoms were prolonged or intermittent fever unresponsive to antibiotics, dysfunction or loss of function of the transplanted organ, pulmonary infiltrates and leukopenia. As our results suggested, reactivation of a latent infection appears to be the most probable etiologic factor contributing to HCMV infection after transplantation.

New triple microbore cannula system for push-pull perfusion of brain nuclei of the rat

A new miniaturized triple-barreled cannula system has been developed for the push-pull perfusion of a circumscribed area of brain tissue and/or simultaneous microinjection of a drug or other chemical substance at the same site. A three-lumen, microbore glass capillary tube is drawn to a length of 10-15 mm with a tip diameter of 150-190 microM and connected by lengths of PE tubing to a multichannel peristaltic pump. An artificial CSF is then perfused through either one or two tubes at a rate of 5.0-10.0 microliters/min at a selected site. Thus, a pharmacological receptor agonist and/or antagonist, for example, can be delivered simultaneously to the tissue quantitatively to achieve steady-state levels over time. Alternatively, a single volume of a given drug can be micro-injected at the perfusion site during the course of a push-pull perfusion, simply by replacing one push channel with an injection tube. In both cases, aliquots of CSF perfusate from the pull channel(s) are collected on ice for assay by HPLC or other procedures. Because of the diminutive size of the triple-bore cannula system, it is now possible to perfuse an individual nucleus in the hypothalamus or lower brainstem not only with minimal cytopathological damage but also with a punctate dispersion of the perfusion medium. The large number of possible in vivo manipulations which can be undertaken using this cannula system is illustrated experimentally by recovery studies of [14C]glutamate and 45Ca from the nucleus tractus solitarius and hypothalamus of the rat.

[Biological characteristics of Psoralea corylifolia L]

A study has been made on the biological characteristics of Psoralea corylifolia under general cultivating conditions. To search for the laws of growth and development so as to facilitate further studies on the cultivating techniques for higher production of Psoralea corylifolia.

Presence of amino acids and insulin in a chemically defined medium improves development of 8-cell rat embryos in vitro and subsequent implantation in vivo

This study examined the effects of some components in a chemically defined medium on rat 8-cell embryo development in vitro. The basal medium was a modified culture medium for in vitro fertilization of rat oocytes, containing inorganic salts and energy substrates. After 36 h in culture, 28.8% of the 8-cell embryos developed into blastocysts in the basal medium. This percentage was increased by supplementing the basal medium with free amino acids, but not a premix of insulin/transferrin/selenium (ITS). However, ITS synergized the beneficial effect of amino acids. The beneficial effect of free amino acids could not be duplicated by bovine serum albumin. The synergistic action of ITS was primarily due to insulin. The removal of glucose and/or phosphate from the culture medium had no effect on embryo development in vitro. After transfer to unilaterally pregnant rats, 23.1% of the blastocysts formed in the basal medium developed to Day 18 fetuses, compared to 64.3% for those formed in the medium containing amino acids. These data indicate that the presence of amino acids in the culture medium is beneficial for embryo development in vitro and for implantation and fetal development following transfer to pregnant recipients.

Sequential anaerobic degradation of 2,4-dichlorophenol in freshwater sediments

2,4-Dichlorophenol (2,4-DCP) was anaerobically degraded in freshwater lake sediments. From observed intermediates in incubated sediment samples and from enrichment cultures, the following sequence of transformations was postulated. 2,4-DCP is dechlorinated to 4-chlorophenol (4-CP), 4-CP is dechlorinated to phenol, phenol is carboxylated to benzoate, and benzoate is degraded via acetate to methane and CO2; at least five different organisms are involved sequentially. The rate-limiting step was the transformation of 4-CP to phenol. Sediment-free enrichment cultures were obtained which catalyzed only the dechlorination of 2,4-DCP, the carboxylation of phenol, and the degradation of benzoate, respectively. Whereas the dechlorination of 2,4-DCP was not inhibited by H2, the dechlorination of 4-CP, and the transformation of phenol and benzoate were. Low concentrations of 4-CP inhibited phenol and benzoate degradation. Transformation rates and maximum concentrations allowing degradation were determined in both freshly collected sediments and in adapted samples: at 31 degrees C, which was the optimal temperature for the dechlorination, the average adaptation time for 2,4-DCP, 4-CP, phenol, and benzoate transformations were 7, 37, 11 and 2 days, respectively. The maximal observed transformation rates for these compounds in acclimated sediments were 300, 78, 2, 130, and 2,080 micromol/liter(-1)/day(-1), respectively. The highest concentrations which still allowed the transformation of the compound in acclimated sediments were 3.1 m/M 2,4-DCP, 3.1 mM 4-CP, 13 mM phenol, and greater than 52 mM benzoate. The corresponding values were lower for sediments which had not been adapted for the transformation steps.

Interactions of 7-[3-(4-[2,3-dimethylphenyl]piperazinyl)-propoxy]-2(1H)-quinolinone binding in rat striatum: effects of lesions

7-[3-(4-[2,3-Dimethylphenyl]piperazinyl)propoxy]-2(1H)-quinolinone (OPC-4392), a presynaptic dopamine autoreceptor agonist and postsynaptic D-2 receptor antagonist (Yasuda et al., Life Sci. 42: 1941-1954, 1988), was studied for its binding characteristics at 3H-SCH 23390-labeled dopamine D-1 receptors and 3H-spiperone-labeled dopamine D-2 receptors in rat striatum. The binding affinity of OPC-4392 for 3H-spiperone-labeled D-2 receptors was 500 times higher than for 3H-SCH 23390-labeled D-1 receptors. 6-Hydroxydopamine lesions of striatum and high-frequency current lesions of medial forebrain bundle did not affect the competition of OPC-4392 for 3H-spiperone binding. Kainic acid lesions of striatum significantly changed the one-site model fit to a two-site model fit of the competition curve of OPC-4392 for 3H-spiperone binding, suggesting that OPC-4392 competed with 3H-spiperone binding differently for postsynaptic dopamine D-2 receptors and for presynaptic dopamine autoreceptors.

[Quantitative assay method for total saponins in Panax quinquefolium Api]

This article adopts macro-reticular resins to separate and get rid of water soluble impurities such as carbohydrate in Panax quinquefolium so as to determine its total saponin content by spectrophotometry. This method also yields good results in determining the total saponins in P. ginseng ora solution. For the control or appraise of the quality of preparations containing P. quinquefolium or P. ginseng oral solutions this method has practice value.

An electron microscopic study on substance P-like immunoreactive nerve fibers in the pars distalis of the adenohypophysis in the dog

The pars distalis of the adenohypophysis has recently been proved to be innervated by substance P-like immunoreactive nerve fibers in the monkey and the dog. The present study investigated immuno-electron microscopically the morphology of these nerve fibers and their relationship to anterior pituitary gland cells in the dog. The nerve fibers were unmyelinated and varicose. Direct contacts between them and every cell type of the gland could be ascertained, including folliculostellate cells. Typical synapses were identified on somatotropes and corticotropes. Most of them were of asymmetrical type with round to oval small clear vesicles and scattered large dense-cored vesicles. Occasional symmetrical type synapses were also seen. The results imply that substance P-like immunoreactive nerve fibers have an effector role in the pars distalis of the dog.

Gene imprinting and major histocompatibility complex class I antigen expression in the rat placenta

Ultrastructural immunocytochemical studies of the expression of major histocompatibility complex class I antigens in the placentas of inbred rats were performed using placentas derived from natural matings and from embryo transfers into females made pseudopregnant by mechanical stimulation. The studies utilized the WF (u) and DA (a) strains and monoclonal antibodies to all of the class I antigens involved. All four mating combinations of the two strains showed that only paternal antigens were expressed in the placenta and that they were limited to the basal trophoblast. This conclusion was confirmed using embryo transfer experiments. In allogeneic natural matings, the allele-specific class I transplantation antigens were not expressed on the membrane of the basal trophoblast but they were expressed in embryo transfers involving embryos of the same genotype. In both types of pregnancies, the pregnancy-associated (Pa) antigen was present on the membrane of the basal trophoblast. The antibody response to DA X DA and to WF X DA embryos transferred into pseudopregnant WF females was against the allele-specific RT1.Aa antigen and the Pa antigen, whereas the antibody response to the heterozygous embryo in the natural WF (female) X DA (male) mating was against the Pa antigen only. These results are consistent with the hypothesis that the suppression of the expression of the allele-specific major histocompatibility complex class I antigens occurs shortly after fertilization and that it requires the uterine environment of a natural mating.

Fibronectin in patients with chronic renal failure undergoing dialysis

Fibronectin (FN) levels were determined in 64 cases with chronic renal failure (CRF), some of whom were undergoing dialysis. FN levels were 14.9 +/- 7.6 mg/dl in CRF (n = 20), 13.4 +/- 4.3 mg/dl in patients on continuous ambulatory peritoneal dialysis (CAPD) (n = 20) and 16.7 +/- 7.2 mg/dl in patients on hemodialysis (HD) (n = 24). All the levels were significantly lower than in normal subjects (23.1 +/- 4.6 mg/dl). Serum FN was compared with some nutritional indices. Positive correlations were found between serum FN and nitrogen balance (BN), serum prealbumin (PreA) and transferrin (Tf) in all the patients. With serum albumin (Alb), however, this correlation was only found in patients undergoing dialysis. Negative correlations were found between serum FN and the ratio of serum urea to serum creatinine (Surea/Scr) in CAPD and HD patients. In 10 CAPD patients, the low serum FN levels went up after increased protein intake. This indicates that it was the result of malnutrition due to decreased protein intake. Serum FN level reflects a negative BN earlier and better than serum PreA, Tf and Alb. It is a sensitive, reliable and simple index for judging the nutritional protein status and the effect of nutritional treatment in patients with CRF undergoing dialysis.

[Relation of Fourier transform infrared spectroscopic characteristics of pilose antler and its traditional quality grade]

The relationship between FTIR characteristics of Pilose Antler and its traditional quality grade was studied and a rule governing its quality value "Z" was found. We have thus advanced a new objective target for preparing Pilose Antler tablets and powder.