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At least 289 records · Page 16Linked to original sources
PubMed1989

Haemodynamic responses during general anaesthesia for renal transplantation in patients with and without hypertensive disease.

Haemodynamic changes in 81 patients undergoing surgery for renal transplantation were studied. They were allocated to three groups depending on whether or not they had chronic hypertension and which drugs were used to control it. The patients in Group I (N = 18, 22%) were normotensive and were not receiving antihypertensive therapy, those in Group II (N = 21, 26%) were taking beta-blockers and those in Group III (N = 42, 52%) both beta-blockers and vasodilating agents. Antihypertensive medication was continued as prescribed until surgery. No anticholinergic premedication was given. All patients received a standardized anaesthesia which included thiopentone, fentanyl, vecuronium and isoflurane. Mean arterial blood pressure and mean heart rate were lowest in Group I compared with the other groups immediately before induction, following vecuronium and thiopentone administration, and after tracheal intubation (P less than 0.05). After the 10-min induction period, blood pressure and heart rate values did not differ between the groups. Although before and during surgery and anaesthesia central venous pressure did not differ between the groups, CVP was higher in Group I postoperatively compared with the other groups (P less than 0.05). No serious anaesthesia-related complications occurred.

Adrenergic beta-Antagonists↗
PubMed1998

Cerebral hemodynamic response to generalized spike-wave discharges.

PURPOSE: Data in the literature concerning metabolic demand during generalized spike-wave activity (gSW) are conflicting. We investigated instantaneous changes in cerebral blood flow velocities (CBFV) in both middle cerebral arteries (MCAs) by transcranial Doppler sonography (TCD) during gSW paroxysms recorded by scalp EEG. METHODS: In 13 patients, CBFVs in both MCAs were averaged, time-locked to the occurrence of the gSW; respiratory rate (RR) and end-expiratory pco2 were measured in one patient. RESULTS: Nine patients showed significant changes in CBFV during gSW. Four had biphasic flow changes with an initial increase (p < 0.05) and a subsequent decrease (p < 0.01). This was partially paralleled by an increase in RR (p < 0.01) and a decrease in pco2 (p < 0.01). In three patients, an increase in CBFV that preceded the onset of gSW by several seconds was observed, followed by a decrease in CBFV. Two patients showed a significant decrease only of CBFV. Only gSWs of a median duration of >0.8 s were associated with significant changes in CBFV. CONCLUSIONS: We were able to demonstrate that gSWs of several seconds duration lead to cortical perfusion changes. We suggest that the initial increase of CBFV demonstrated in some patients reflects neuronal activation, whereas the subsequent decrease might in part be due to hyperventilation-induced hypocapnia.

Adult↗
PubMed2006

Treatment with combined oral contraceptives induces a rise in serum C-reactive protein in the absence of a general inflammatory response.

BACKGROUND: The role of inflammation in the pathogenesis of cardiovascular disease is well established. C-reactive protein (CRP) is the strongest independent predictor of myocardial infarction and stroke in women. Recent studies have indicated that CRP levels are raised during use of combined oral contraceptives (COCs). OBJECTIVES: The aim of the study was to investigate the effect of COCs on serum CRP levels and to indicate the underlying mechanisms of an expected increase. METHOD: In a prospective randomized cross over-study 35 women used two different preparations of COC, one second and one third generation. Serum levels of CRP, serum amyloid A (SAA), interleukin-6 (IL-6), tumor necrosis factor alpha (TNFalpha), antibodies against oxidized LDL, insulin and insulin-like growth factor-I (IGF-I) along with insulin-like growth factor binding protein-1 (IGFBP-1) and IGFBP-3 were analyzed before and during the two treatments. E-selectin, von Willebrand factor and factor VIII concentrations in plasma were also measured. RESULTS: A rise in serum CRP was observed during both treatments; the median level increased from 0.45 mg L(-1) at baseline to 1.48 mg L(-1) with second generation and to 2.02 mg L(-1) with third generation COC. The serum levels of SAA increased slightly during treatment with the third generation COC. IL-6 and TNFalpha were unaffected by treatment. Both preparations lowered IGF-I and raised IGFBP-1 and IGFBP-3 concentrations. CONCLUSION: The raised serum CRP concentration during treatment with COCs appears to be related to a direct effect on hepatocyte CRP synthesis and does not reflect IL-6 mediated inflammation, endothelial activation or induction of insulin resistance.

Adolescent↗
PubMed1985

Blood pressure responses to care procedures in ventilated preterm infants.

Responses of mean aortic blood pressure to sequences of routine care procedures in 22 ventilated, preterm infants were studied daily for the first 3 days of life. In the first 11 infants standard care procedures were used, whereas the next 11 infants were preoxygenated by a preceding 10% increase in inspired oxygen concentration; in these infants, chest physiotherapy was entirely omitted while the frequency of endotracheal suctioning was reduced. A total of 259 blood pressure responses were recorded. In general, responses were biphasic, consisting of an initial blood pressure drop followed by a greater blood pressure rise of longer duration. Baseline blood pressure, as well as the minimum and maximum blood pressure during the care procedures, increased with gestational age and with postnatal age. The blood pressure drop was most pronounced in the infants requiring the most intensive ventilatory support and was reduced by modifying the care procedures. The blood pressure rise was the least in the infants receiving pancuronium and phenobarbitone. Eight infants, 4 in each group, had intraventricular haemorrhage; in these infants, the care procedures induced more pronounced blood pressure drops in the first day of life when compared to the infants without haemorrhage.

Blood Pressure↗
PubMed2004

RpoS is not central to the general stress response in Borrelia burgdorferi but does control expression of one or more essential virulence determinants.

Borrelia burgdorferi, the Lyme disease spirochete, undergoes dramatic changes in antigenic composition as it cycles between its arthropod and mammalian hosts. A growing body of evidence suggests that these changes reflect, at least in part, the need for spirochetes to adapt to the physiological stresses imposed by abrupt changes in environmental conditions and nutrient availability. In many microorganisms, global responses are mediated by master regulators such as alternative sigma factors, with Escherichia coli RpoS (sigmaS) serving as a prototype. The importance of this transcriptional activator in other bacteria, coupled with the report by Hubner et al. (A. Hubner, X. Yang, D. M. Nolen, T. G. Popova, F. C. Cabello, and M. V. Norgard, Proc. Natl. Acad. Sci. USA 98:12724-12729, 2001) demonstrating that the borrelial RpoS ortholog controls expression of OspC and decorin-binding protein A (DbpA), prompted us to examine more closely the roles of RpoS-dependent and -independent differential gene expression in physiological adaptation by the Lyme disease spirochete. We observed that B. burgdorferi rpoS (rpoSBb) was induced following temperature shift and transcript levels were further enhanced by reduced pH (pH 6.8). Using quantitative real-time reverse transcription-PCR (RT-PCR), we demonstrated that, in contrast to its ortholog (rpoSEc) in Escherichia coli, rpoSBb was expressed at significant levels in B. burgdorferi throughout all phases of growth following temperature shift. By comparing a B. burgdorferi strain 297 rpoSBb mutant to its wild-type counterpart, we determined that RpoSBb was not required for survival following exposure to a wide range of environmental stresses (i.e., temperature shift, serum starvation, increased osmolality, reactive oxygen intermediates, and increased or reduced oxygen tension), although the mutant was more sensitive to extremes of pH. While B. burgdorferi strains lacking RpoS were able to survive within intraperitoneal dialysis membrane chambers at a level equivalent to that of the wild type, they were avirulent in mice. Lastly, RT-PCR analysis of the ospE-ospF-elp paralogous lipoprotein families complements earlier findings that many temperature-inducible borrelial loci are controlled in an RpoSBb-independent manner. Together, these data point to fundamental differences between the role(s) of RpoS in B. burgdorferi and that in E. coli. Rather than functioning as a master regulator, RpoSBb appears to serve as a stress-responsive activator of a subset of virulence determinants that, together with the RpoS-independent, differentially expressed regulon, encompass the spirochete's genetic programs required for mammalian host adaptation.

Animals↗
PubMed2006

Comparison of the RpoH-dependent regulon and general stress response in Neisseria gonorrhoeae.

In the gammaproteobacteria the RpoH regulon is often equated with the stress response, as the regulon contains many of the genes that encode what have been termed heat shock proteins that deal with the presence of damaged proteins. However, the betaproteobacteria primarily utilize the HrcA repressor protein to control genes involved in the stress response. We used genome-wide transcriptional profiling to compare the RpoH regulon and stress response of Neisseria gonorrhoeae, a member of the betaproteobacteria. To identify the members of the RpoH regulon, a plasmid-borne copy of the rpoH gene was overexpressed during exponential-phase growth at 37 degrees C. This resulted in increased expression of 12 genes, many of which encode proteins that are involved in the stress response in other species. The putative promoter regions of many of these up-regulated genes contain a consensus RpoH binding site similar to that of Escherichia coli. Thus, it appears that unlike other members of the betaproteobacteria, N. gonorrhoeae utilizes RpoH, and not an HrcA homolog, to regulate the stress response. In N. gonorrhoeae exposed to 42 degrees C for 10 min, we observed a much broader transcriptional response involving 37 differentially expressed genes. Genes that are apparently not part of the RpoH regulon showed increased transcription during heat shock. A total of 13 genes were also down-regulated. From these results we concluded that although RpoH acts as the major regulator of protein homeostasis, N. gonorrhoeae has additional means of responding to temperature stress.

Gene Expression Regulation, Bacterial↗
PubMed1989

Responses by general practitioners in Avon to proposals for general practice in the white paper Working for Patients.

OBJECTIVE: To determine the views of Avon's general practitioners about the general practice proposals within the government's white paper Working for Patients. DESIGN: Postal questionnaire survey. SETTING: A county in south west England. SUBJECTS: All general practitioner principals (n = 537) under contract with Avon Family Practitioner Committee. MEASUREMENTS AND MAIN RESULTS: 492 doctors (92%) responded to the survey. More than three quarters of the respondents were opposed to the government's proposals on budgets for specific surgical procedures, prescribing, and diagnostic tests; and between 63% and 93% felt negative about advantages that might accrue from the proposals. Over three quarters of general practitioners were in favour of family practitioner committees monitoring work load, prescribing, and referrals. General practitioners in large, potentially budget holding practices held similar views to doctors in smaller practices. CONCLUSIONS: Avon's general practitioners substantially reject most of the government's proposals about general practice in the white paper Working for Patients.

Attitude of Health Personnel↗
PubMed1977

Adaptation to short-term respiratory effects of ozone in men exposed repeatedly.

To investigate whether adaptation which modifies some acute effects of ozone (O3) exposure can develop in humans, six male volunteers with respiratory hyperreactivity were exposed in a controlled environment chamber to 0.5 ppm O3 2h/day for 4 successive days under conditions stimulating ambient pollution exposures. One subject showed little measurable response, while five showed function decrement on exposure days 1-3 which was largely reversed by day 4. Symptom responses generally paralleled the physiological responses. These results suggest that at least some humans adapt to O3 exposure at concentrations occurring in severe community air pollution episodes, to the extent that obvious acute respiratory effects are prevented. Other adverse effects of O3 may not be prevented by this adaptation.

Adaptation, Physiological↗
PubMedDate not supplied

Cyclic nucleotide-gated channel activation is not required for activity-dependent labeling of zebrafish olfactory receptor neurons by amino acids.

The olfactory epithelium of fish is heterogeneous both with respect to the types of receptor cells (ORNs) present and the families of odorant receptors expressed in these cells. As a consequence of this diversity, the transduction cascade(s) activated by odorants has yet to be unambiguously established. In the current study, electrophysiological and activity-dependent labeling techniques were used to assess the role of the cyclic nucleotide-gated channel in zebrafish olfactory transduction. Both amino acid and bile salt odorants elicited robust electrophysiological responses, however, activity-dependent labeling of ORNs could be stimulated only by the amino acid odorants. An adenylate cyclase (AC) activator (forskolin) and a phosphodiesterase inhibitor (3-isobutyl-1-methylxanthine, IBMX) also elicited robust electrophysiological responses; generally larger than the responses elicited by either the amino acid or bile salt odorants. However, neither forskolin alone or a mixture of forskolin and IBMX stimulated activity-dependent labeling. Bathing the olfactory epithelium with forskolin, which presumably increased the intracellular concentration of cAMP, reduced the responses to bile salt odorants to a significantly greater extent than amino acid odorants. Collectively, these findings suggest that the transduction of amino acid input does not rely primarily on cyclic nucleotide-gated (CNG) channel activation and that CNG channel activation may be required for the transduction of bile salt input.

Agmatine↗
PubMed1989

Symptoms and treatment responses of generalized anxiety disorder patients with high versus low levels of cardiovascular complaints.

Clinical observations suggest that patients with generalized anxiety disorder differ in somatic symptoms. The authors compared 28 patients with generalized anxiety disorder who had high levels of cardiovascular complaints with 32 patients with generalized anxiety disorder who had low levels of cardiovascular complaints on rating instruments, physiological measures, and use of anxiolytic medication. The two groups differed on somatic but not psychic symptoms on rating instruments. Patients with high levels of cardiovascular symptoms had higher levels of cardiac lability and required higher doses of alprazolam. These findings suggest that anxious patients with comparable levels of psychic anxiety may differ in levels of physical symptoms.

Adult↗
PubMed2004

Antiviral efficacy of abacavir in antiretroviral therapy-experienced adults harbouring HIV-1 with specific patterns of resistance to nucleoside reverse transcriptase inhibitors.

OBJECTIVE: To evaluate HIV-1 reverse transcriptase genotypic and phenotypic indicators of resistance to abacavir (ABC) as predictors of ABC antiviral efficacy. DESIGN: The study was a retrospective, combined analysis of five multicentre trials in which ABC was added as a single agent to background antiretroviral therapy in experienced adults. METHODS: Baseline HIV-1 genotype and phenotypic susceptibility to ABC were determined and the association of genotype and phenotype with virological response after addition of ABC was analysed. RESULTS: Overall, 68% of these therapy-experienced subjects had a virological response (>0.5 log10 or <400 copies/ml; 42% <400 copies/ml) 4 weeks after addition of ABC. Multivariable analyses revealed no significant difference in the response rate between subjects with wild-type virus and those carrying virus with 1-2 nucleoside reverse transcriptase inhibitor (NRTI)-associated mutations. At the 4-week time-point subjects harbouring virus with > or = 3 mutations associated with NRTI resistance were significantly less likely to respond to ABC than were subjects harbouring wild-type virus (P=0.015). However, at the last viral RNA measurement after addition of ABC (12-28 weeks), > or = 4 mutations were required to diminish virological response significantly (P=0.012). Phenotypic resistance was also predictive of antiviral response. Significant breakpoints were identified for virological responses for the PhenoSense HIV assay and the Antivirogram assay. CD4 responses generally paralleled the antiviral responses with a median increase of 55 cells/microl by weeks 12-28. CONCLUSIONS: Virological response to ABC may be diminished significantly by multiple NRTI-associated mutations and/or by reductions in phenotypic susceptibility to ABC. However, many subjects with baseline samples showing evidence of resistance to NRTIs respond to ABC.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Homozygosity for a dominant negative thyroid hormone receptor gene responsible for generalized resistance to thyroid hormone.

Generalized resistance to thyroid hormones (GRTH) commonly results from mutations in the T3-binding domain of the c-erbA beta thyroid hormone receptor gene. We have reported on a novel deletion mutation in c-erbA beta in a kindred, S, with GRTH. One patient from this kindred was the product of a consanguineous union from two affected members and was homozygous for the beta-receptor defect. This patient at 3.5 weeks of age had unprecedented elevations of TSH, free T4, and free T3 (TSH, 389 mU/L; free T4, 330.8 pmol/L; free T3, 82,719 fmol/L). He displayed a complex mixture of tissue-specific hyperthyroidism and hypothyroidism. He had delayed growth (height age, 1 3/12 yr at chronological age 2 9/12 yr) and skeletal maturation (bone age, 4 months), and developmental delay (developmental age, 8 months), but he was quite tachycardic. The homozygous patient of kindred S is markedly different from a recently reported patient with no c-erbA beta-receptor. This difference indicates that a dominant negative form of c-erbA beta in man can inhibit at least some thyroid hormone action mediated by the c-erbA alpha-receptors.

Adolescent↗