Evidence for a lipochaperonin: association of active protein-folding GroESL oligomers with lipids can stabilize membranes under heat shock conditions.

During heat shock, structural changes in proteins and membranes may lead to cell death. While GroE and other chaperone proteins are involved in the prevention of stress-induced protein aggregation and in the recovery of protein structures, a mechanism for short-term membrane stabilization during stress remains to be established. We found that GroEL chaperonin can associate with model lipid membranes.

Effects of the application of aluminium, strontium and magnesium solutions to the leaf surface of maize, and determinations of these elements by ICP-AES.

The uptakes of aluminium, magnesium and strontium through maize leaves were investigated. The plants were grown in the light and in the dark (etiolation). Samples of leaves were digested with a mixture of nitric acid and hydrogen peroxide, and measurements were made by ICP-AES.

Membrane lipid perturbation modifies the set point of the temperature of heat shock response in yeast.

Addition of a saturated fatty acid (SFA) induced a strong increase in heat shock (HS) mRNA transcription when cells were heat-shocked at 37 degrees C, whereas treatment with an unsaturated fatty acid (UFA) reduced or eliminated the level of HS gene transcription at 37 degrees C. Transcription of the delta 9-desaturase gene (Ole1) of Histoplasma capsulatum, whose gene product is responsible for the synthesis of UFA, is up-regulated in a temperature-sensitive strain. We show that when the L8-14C mutant of Saccharomyces cerevisiae, which has a disrupted Ole1 gene, is complemented with its own Ole1 coding region under control of its own promoter or Ole1 promoters of H.

The possible role of uric acid in renal hyper-echogenicity in neonatal hypoxic acute shock.

Sonographic examinations as well as blood and urine chemistry tests were carried out in 4 neonates (3 mature, 1 premature) with transient renal failure, who were suffering from the effects of neonatal asphyxia of varying etiology. The first ultrasound examinations of the kidneys were performed within 24 hours after the hypoxic event. Simultaneously, blood and urine tests for parameters of renal function and purine metabolites were also carried out.

Relation between bronchial and cardiac vagal tone in healthy humans.

A generally increased vagal nervous activity was suggested to exist in bronchial asthma; however, this contention has never been fully tested. Before studying vagal activity in asthma, we raised the question if there existed any relation between vagal outflows to different target organs in the physiologic state. The specific aim of this study was to determine the relation between the resting level of bronchial and cardiac vagal activity in healthy volunteers.

Facile catalyst separation without water: fluorous biphase hydroformylation of olefins.

A novel concept for performing stoichiometric and catalytic chemical transformations has been developed that is based on the limited miscibility of partially or fully fluorinated compounds with nonfluorinated compounds. A fluorous biphase system (FBS) consists of a fluorous phase containing a dissolved reagent or catalyst and another phase, which could be any common organic or nonorganic solvent with limited or no solubility in the fluorous phase. The fluorous phase is defined as the fluorocarbon (mostly perfluorinated alkanes, ethers, and tertiary amines)-rich phase of a biphase system.

[Autoantibodies or immune defense against cholesterol?].

Serological study was made on the lues aspecific positive sera (BAP); The serum reactivity was demonstrated by Kolmer and rapid plasma reagin (RPR) tests. The specificity was verified by treponema immobilization est (TPIT), fluorescent treponemal antibody (FTA-ABS) and treponema haemagglutination (TPHA) tests. The BAP sera were studied by enzyme labelled immunoassay (ELISA) with the isolated antigen components of Kolmer and RPR tests.

Role of nitric oxide in regulating cerebrocortical oxygen consumption and blood flow during hypercapnia.

The effect of the nitric oxide (NO) synthase inhibitor N omega-nitro-L-arginine methyl ester (L-NAME) on the response of cerebrocortical oxygen consumption (CMRO2) and blood flow (CBF) to two levels of hypercapnia (PaCO2 approximately 60 mm Hg and PaCO2 approximately 90 mm Hg) was investigated in ketamine-anesthetized rats. CBF was calculated using the Kety-Schmidt approach and CMRO2 was calculated from the product of CBF and the arteriovenous (superior sagittal sinus) difference for oxygen. L-NAME treatment did not have a significant effect on either CMRO2 or CBF under normocapnic conditions but inhibited the hypercapnic increase of CMRO2 and the hypercapnic increase in CBF.

The primary signal in the biological perception of temperature: Pd-catalyzed hydrogenation of membrane lipids stimulated the expression of the desA gene in Synechocystis PCC6803.

One of the well-characterized phenomena associated with the acclimation of organisms to changes in ambient temperature is the regulation of the molecular motion or "fluidity" of membrane lipids via changes in the extent of unsaturation of the fatty acids of membrane lipids. The enzymes responsible for this process when the temperature is decreased are the desaturases, the activities of which are enhanced at low temperature. To examine whether the change in the fluidity of membrane lipids is the first event that signals a change in temperature, we studied the effect of the Pd-catalyzed hydrogenation of membrane lipids on the expression of the desA gene, which is responsible for the desaturation of fatty acids of membrane lipids in the cyanobacterium Synechocystis PCC6803.

The temperature-dependent expression of the desaturase gene desA in Synechocystis PCC6803.

We examined the temperature-dependent regulation of the expression of the desA gene, which encodes delta 12 desaturase of Synechocystis PCC6803. The level of desA transcript increased 10-fold within 1 h upon a decrease in temperature from 36 degrees C to 22 degrees C. This suggests that the low-temperature-induced desaturation of membrane lipid fatty acids is regulated at the level of the expression of the desaturase genes.

A second groEL-like gene, organized in a groESL operon is present in the genome of Synechocystis sp. PCC 6803.

Using a groEL gene of Synechococcus sp. PCC 7942 as a DNA probe, a 4.8-kilobase pair (kbp) BamHI fragment of chromosomal DNA of Synechocystis sp.

Effect of the cold pressor test in healthy and hyperacid subjects.

The aim of this study was to estimate the effects of the cold pressor test (CPT) on hemodynamic changes and to analyze the differences in the changes between normal and hyperacid subjects. Twelve healthy volunteers and 12 hyperacid patients were studied. The different hemodynamic parameters (basic impedance, ZO; heart rate, HR; systolic and diastolic blood pressure, RRs and RRd; ventricular ejection time, VET; stroke volume, SV; cardiac output, CO; rate-pressure-product, RPP) were measured and calculated with the impedance cardiographic method (ICG).

Hemorrhagic hypotension impairs endothelium-dependent relaxations in the renal artery of the cat.

The effect of hemorrhagic shock on the vasodilatory responses of the feline renal artery was studied in vitro. In sodium pentobarbital anaesthetized cats, a steady level of hypotension (50 mm Hg) was reached by bleeding into a reservoir and maintained at this level by further bleeding or autotransfusion for 2 hr (shock). One to 3 mm long rings of the arteries (from control and shocked animals) were suspended for isometric tension recording in organ chambers filled with modified Krebs-Henseleit solution, aerated with 95% O2-5% CO2 at 37 degrees C.

Heat shock protein synthesis of the cyanobacterium Synechocystis PCC 6803: purification of the GroEL-related chaperonin.

Synechocystis PCC 6803 cells could be induced to synthesize four major HSPs with apparent molecular sizes of 70, 64, 15 and 14 kDa. Heat stress at 42.5 degrees C appeared to be the optimum temperature for HSP formation in cells grown at 30 degrees C.

[Jaundice with indirect bilirubinemia via the mother's milk].

Among the clinical entities included in the differential diagnosis of the prolonged jaundice at the end of neonatal period and in the small infant is the jaundice due to mother's milk, whose incidence is of 0.5-2% in the naturally fed infants. The authors present two cases in which the diagnosis was reached by exclusion and confirmed by the therapeutically positive test.

Lipid hydrogenation induces elevated 18:1-CoA desaturase activity in Candida lipolytica microsomes.

Microsomal membranes prepared from the mesophilic yeast Candida lipolytica grown at 10 degrees C were hydrogenated by the homogeneous Pd-catalyst, palladium di (sodium alizarine sulfonate) (Pd(QS)2). After hydrogenation to various levels, the microsomes were washed free of the Pd-complex and transferred to a reaction mixture (containing NADH, MgCl2, ATP, CoA and [14C]18:1-CoA) for assay of 18:1-CoA desaturase activity. Microviscosity alterations were also followed by measuring changes in DPH fluorescence polarization.

Endothelium-dependent influence of small changes in extracellular magnesium concentration on the tone of feline middle cerebral arteries.

The aim of this study was to investigate the effect of small alterations in the extracellular magnesium concentration on the tone of feline middle cerebral arteries and to examine the role of the endothelium in these responses. We measured the isometric tension of isolated arterial rings placed between two stainless steel wires in a tissue chamber containing Krebs-Henseleit solution aerated with a gas mixture containing 95% O2 and 5% CO2 at 37 degrees C. After precontraction with noradrenaline, a decrease of the extracellular magnesium concentration from 1.

Complex hydrogenation/oxidation reactions of the water-soluble hydrogenation catalyst palladium di (sodium alizarinmonosulfonate) and details of homogeneous hydrogenation of lipids in isolated biomembranes and living cells.

Palladium di (sodium alizarinmonosulfonate) is a highly efficient catalyst for the hydrogenation of unsaturated fatty acids esterified in lipids of model or biological membranes, enabling the study of the relationship between function and the physical state of membranes. However, the catalyst shows a complex behavior in the action of molecular hydrogen and oxygen, giving rise to the formation of at least four products. Two of these are free radicals.

Contractile and endothelium-dependent dilatory responses of cerebral arteries at various extracellular magnesium concentrations.

To clarify the effect of extracellular magnesium (Mg2+) on the vascular reactivity of feline isolated middle cerebral arteries, the effects of slight alterations in the Mg2+ concentration on the contractile and endothelium-dependent dilatory responses were investigated in vitro. The contractions, induced by 10(-8)-10(-5) M norepinephrine, were significantly potentiated at low Mg2+ (0.8 mM v.

Differential vascular actions of ethanol in feline middle cerebral and mesenteric artery.

The vascular actions of ethanol on feline middle cerebral and mesenteric arteries were investigated in vitro. Ethanol (20-500 mM) caused potent contraction in cerebral arteries, but it contracted the mesenteric arteries only weakly. In the middle cerebral artery (but not in the mesenteric artery) ethanol (300 mM) potentiated the noradrenaline (5.