Diethylmesoxalate hydrate,a new irreversible inhibitor of cholinesterases

Summary Bovine erythrocyte acetylcholinesterase and human plasma cholinesterase are irreversibly inhibited by diethylmesoxalate hydrate, the inhibition potency being comparable to that of certain insecticidal organophosphates and carbamates. Insect cholinesterases, however, appear to be much less affected by diethylmesoxalate hydrate. The compound was also found to inhibit the hydrolysis of paraoxon by rabbit plasma A-esterase, but in a reversible mode.     

Effect of anaesthesia on growth hormone secretion in the domestic fowl (Gallus domesticus)

Summary Chloral hydrate, Equithesin, Althesin, Rompun, Sagatal and ether anaesthesia lowered the concentration of plasma growth hormone in immature cockerels. Handling and serial bleeding of the conscious controls had no effect on the growth hormone concentration.     

The effect of anesthetics on the basal secretion of immunoreactive growth hormone in rats]

The authors investigated basal levels of plasma immunoreactive growth-hormone in the rat (R-GH) after administration of 3 different anesthetic drugs: urethan, chloral hydrate and gamma-hdroxy-butyrate (GHB). Lowest R-GH concentrations (5 +/- 3 ng/ml) are observed after urethan; they are significantly higher (15 +/- 4 ng/ml) after chloral hydrate but this anesthetic also causes hyperglycemia (210 +/- 30 mg/100 ml). Normal blood glucose levels are observed under GHB narco-analgesia which elicits a clear-cut R-GH secretory episode (70 +/- 5 ng/ml); basal values (12 +/- 3 ng/ml) are maintained for several hours thereafter.     

不同体系中甲烷水合物储气特性实验研究

为了研究不同体系甲烷水合物的储气特性，利用自行设计的小型水舍物合成装置，分别合成了一系列不同体系下的甲烷水合物（包括不同压力下的十二烷基硫酸钠（SDS）水溶液-甲烷体系、粉末冰-甲烷体系以及粉末冰-不同粒度砂-甲烷体系）；并采用真空容积法分别测定了三种不同体系条件下水合物样品的储气量；结合水合物生成动力学知识，探讨了不同反应时间、压力和环境介质对形成笼状结构水合物储气量的影响。结果表明，在SDS-水-甲烷体系中，相同的反应时间内，随着体系甲烷初始压力的增大，水合物储气量逐渐增大；冰粉-甲烷体系中，合成方式（静止或振摇）较初始压力对储气量影响更大；冰粉-沉积物-甲烷体系中。甲烷水合物储气量与沉积物粒度的变化无明显关系。     

Chloral hydrate induced haploidization inAspergillus nidulans

Summary This is the first report of induction of haploidization inAspergillus nidulans by chloral hydrate, which is an efficient polyploidizing agent for higher plants and a psychotropic drug for man. A new procedure has been described to isolate haploids from diploids with a very high frequency, as compared top-fluorophenylalanine, which is generally used for this purpose.     

Chromosome counting on 79-year-old dried seaweed,Porphyra leucostica (Rhodophyta)

Summary An adaptation of the aceto-iron-haematoxylin-chloral hydrate staining solution is described for chromosome counting of dried seaweeds. The chromosome number ofPorphyra leucosticta (Rhodophyta) collected recently and fixed in ethanol-acetic acid compares well with material of the same species collected and dried in 1897. The significance of this new source of data, allowing the study of the old type material, is stressed in the paper.Under a CNPq fellowship No. 5503/74.We thank Prof.C. Pavan for valuable suggestions.     

慢性心力衰竭失代偿患者血浆β-内啡肽与脑钠肽变化的意义

目的探讨慢性心力衰竭（CHF）患者血浆β-内啡肽（β-EP）在诊断和预后中的意义。材料和方法CHF患者71例，按NY-HA心功能分级分为3组（Ⅱ一Ⅳ）。应用放射免疫法（RIA）测患者血浆β-EP浓度，采用床旁Triager BNP测定仪测定同期血浆脑钠肽（BNP）量。结果CHF各组血浆β-EP和BNP含量与对照组相比显著性升高，并随心功能分级的增加呈上升趋势（P〈0．01）。CHF组血浆β-EP与BNP呈显著性线性正相关（P〈0．01）；血浆β-EP和BNP水平与EF值及EF呈显著性线性负相关（P〈0．01）。血浆中β-内啡肽含量越高则半年内心血管事件发生率越高（P〈0．01）。结论血浆β-内啡肽和BNP的水平是诊断CHF的重要实验室指标，并可用于心功能及预后的评估。     

Vasoactive intestinal polypeptide stimulates prolactin release in vivo in the ring dove (Streptopelia risoria)

Summary I.v. administration of vasoactive intestinal polypeptide (VIP) to ring doves significantly elevated the plasma concentration of prolactin after 10 min in a dose-related manner. The plasma prolactin concentration of nonbreeding doves with low basal levels was increased by a similar amount as in brooding doves whose initially high concentration of plasma prolactin had been reduced by nest deprivation prior to treatment.     

Vasoactive intestinal polypeptide stimulates prolactin release in vivo in the ring dove (Streptopelia risoria)

I.v. administration of vasoactive intestinal polypeptide (VIP) to ring doves significantly elevated the plasma concentration of prolactin after 10 min in a dose-related manner. The plasma prolactin concentration of nonbreeding doves with low basal levels was increased by a similar amount as in brooding doves whose initially high concentration of plasma prolactin had been reduced by nest deprivation prior to treatment.     

Effect of haemolysis on plasms and serum immunoglobulin estimations.

Plasma IgG, IgM and IgA estimations were carried out in blood samples with varying degrees of haemolysis, produced by controlled ultrasonication. Extent of haemolysis was determined by plasma haemoglobin, plasma potassium and packed cell volume; and plasma IgG, IgM and IgA estimations showed a steady and significant fall with increasing haemolysis. A calculated correction is proposed which compensates for the dilutional effect of haemolysis, during estimations of plasma and serum immunoglobulins.     

Detailed analysis of the plasma extracellular vesicle proteome after separation from lipoproteins

The isolation of extracellular vesicles (EVs) from blood is of great importance to understand the biological role of circulating EVs and to develop EVs as biomarkers of disease. Due to the concurrent presence of lipoprotein particles, however, blood is one of the most difficult body fluids to isolate EVs from. The aim of this study was to develop a robust method to isolate and characterise EVs from blood with minimal contamination by plasma proteins and lipoprotein particles. Plasma and serum were collected from healthy subjects, and EVs were isolated by size-exclusion chromatography (SEC), with most particles being present in fractions 8–12, while the bulk of the plasma proteins was present in fractions 11–28. Vesicle markers peaked in fractions 7–11; however, the same fractions also contained lipoprotein particles. The purity of EVs was improved by combining a density cushion with SEC to further separate lipoprotein particles from the vesicles, which reduced the contamination of lipoprotein particles by 100-fold. Using this novel isolation procedure, a total of 1187 proteins were identified in plasma EVs by mass spectrometry, of which several proteins are known as EV-associated proteins but have hitherto not been identified in the previous proteomic studies of plasma EVs. This study shows that SEC alone is unable to completely separate plasma EVs from lipoprotein particles. However, combining SEC with a density cushion significantly improved the separation of EVs from lipoproteins and allowed for a detailed analysis of the proteome of plasma EVs, thus making blood a viable source for EV biomarker discovery.     

Effect of haemolysis on plasma and serum immunoglobulin estimations

Summary Plasma IgG, IgM and IgA estimations were carried out in blood samples with varying degrees of haemolysis, produced by controlled ultrasonication. Extent of haemolysis was determined by plasma haemoglobin, plasma potassium and packed cell volume; and plasma IgG, IgM and IgA estimations showed a steady and significant fall with increasing haemolysis. A calculated correction is proposed which compensates for the dilutional effect of haemolysis, during estimations of plasma and serum immunoglobulins.     

Die Bedeutung von Plasmafaktoren für die isolierte umströmte Kaninchennetzhaut

Summary Theb-wave in the electroretinogram of the isolated retina of the rabbit can be completely preserved by addition of plasma to the perfusing fluid. The plasma factor is a non-protein (heat-stable, molecular size <24Å), and was found in the plasma of rabbit, man, and horse.     

Thiamine-binding activity of Saccharomyces cerevisiae plasma membrane

The specific binding activity to [14C]thiamine was found to be located in hte plasma membrane of Saccharomyces cerevisiae. The activity was inhibited by several thiamine analogs and it was hardly detectable in the plasma membrane from a thiamine transport mutant of Saccharomyces cerevisiae. Some properties of the thiamine-binding activity of yeast plasma membrane are discussed in connection with those of the thiamine transport system.     

Interaction of cortisol and epinephrine in the regulation of leucine kinetics in man

To assess the interaction of the two major stress hormones epinephrine and cortisol in the regulation of leucine kinetics in man, epinephrine (50 ng/kg/min) was infused either alone or in combination with cortisol (2 micrograms/kg/min) into two groups of 6 postabsorptive normal male subjects during 180 min. Plasma leucine concentrations decreased by 28% (p less than 0.05) from baseline during epinephrine treatment (plasma levels 515 pg/ml); this was due to a decrease of leucine appearance (determined by 1-13C-leucine infusions) by 23% (p less than 0.025); leucine oxidation decreased by 29% (p less than 0.05). However, when plasma cortisol concentrations were elevated to supraphysiological levels (16.3 mumol/l) during epinephrine administration, the decreases of leucine plasma concentrations, appearance and oxidation were abolished. Plasma glucose and FFA concentrations were similarly elevated during both kinds of treatment. Since leucine appearance represents a measurement of total body protein breakdown and leucine disappearance into non-oxidative pathways reflects protein synthesis, the data indicate that plasma epinephrine concentrations during severe stress exert a protein anabolic effect in man which may counteract catabolic properties of elevated plasma cortisol.     

Effects of epinephrine on plasma fibrinogen levels in rats submitted to tissue injury

Summary Tissue injury (laparotomy) produces an increase in plasma fibrinogen. This increase is inhibited by the removal of the adrenal medulla, but injection of epinephrine in laparotomized-medullectomized rats returns fibrinogen levels to values similar to those observed in only laparotomized rats. Epinephrine administration to laparotomized rats increases the fibrinogen compared with the group of laparotomized rats without treatment, but epinephrine by itself does not modify plasma fibrinogen levels in uninjured rats. Epinephrine is apparently responsible for the increase of plasma fibrinogen in rats subjected to tissue injury, probably through beta adrenergic stimulation.     

Is glucagon involved in cold acclimatization?

Cold acclimatization in rats at 5 degrees C for 2 weeks caused a significant elevation of plasma glucagon concentration, accompanied by increased plasma FFA and glucose levels. Acute cold exposure at 5 degrees C for 5 or 60 min did not affect these parameters in plasma.     

Corticotropin releasing factor increases the adrenocortical responsiveness to adrenocorticotropin

Summary In the course of studying the plasma adrenocorticotropic hormone (ACTH) and corticosterone responses to synthetic corticotropin releasing factor (CRF), we noted some disparity in the responses. A higher dose (20 g compared with 5 g per rat i.a.) produced an equal plasma ACTH but greater plasma corticosterone response in adult male rats. Thus, we examined the possibility that CRF increases adrenocortical responsiveness to ACTH. CRF significantly (p<0.0005) increased the plasma corticosterone response to ACTH in rats pretreated with dexamethasone. Thus, synthetic CRF increases corticosterone secretion in rats not only by stimulating ACTH secretion, but also by increasing the adrenocortical responsiveness to ACTH.Acknowledgments. This research was supported by grant MT-5183 from the Medical Research Council of Canada and by the Department of Medicine, University of Kentucky.     

Increased melatonin levels after hemorrhagic shock in male and female C3H/HeN mice

Although hemorrhagic shock leads to significant alterations of several hormones, e.g. ACTH, corticosterone and -endorphin, it is not known whether plasma melatonin levels are affected under this condition and if so, whether the effects are comparable in males and females. Using a radioimmunoassay, it was found that plasma melatonin levels were significantly increased in male and proestrus female C3H/HeN mice immediately after hemorrhagic shock. However, in male mice, by two hours after hemorrhage and resuscitation, plasma melatonin returned to levels comparable to those seen in control and sham-operated animals. Proestrus female mice, on the other hand, showed significantly increased plasma melatonin levels at two hours after surgery when compared to unoperated control animals. Although the significance and biological role of the transient increased plasma melatonin levels after hemorrhagic shock remain to be determined, it appears that the pineal gland and/or an extrapineal source of melatonin, of both male and proestrus female mice responds to severe hypotension by increased release of melatonin.     

Detection of human cytomegalovirus (HCMV) DNA from cell-free plasma of immunosuppressed patients by nested PCR: influence of nucleic acid extraction method

Conclusions Blood cells and plasma preparations from HCMV-seropositive healthy blood donors were all nPCR negative. Detection of HCMV DNA from PBMC and granulocytes (DNAemia) of immunosuppressed patients by nPCR did not correlate with the isolation of infectious virus from these cell populations in cell culture (viremia). However HCMV could be isolated in 60% of cases from other materials of the same patient. HCMV DNA detected in blood cells persisted for up to one year in an asymptomatically infected individual after NTX. The sensitivity of HCMV DNA detection in cell-free plasma (up to 5 fg) depended on the method used for DNA isolation. The rate of HCMV DNA detection in plasma was lower than in leukocytes. In all cases of positive plasma PCR infectious virus could be isolated from any other material of the symptomatically infected patients. Therefore HCMV DNA PCR from plasma of immunosuppressed patients seems to be a suitable and easy alternative to HCMV RT/PCR for routine diagnosis of HCMV disease.