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Biomedical subjects

C Ray

Publications and source records attributed to C Ray.

At least 37 records · Page 2Linked to original sources
PubMed1993

Community mental health and managed care.

CMHOs are the heirs to a rich tradition of coordinated and comprehensive services and appropriate clinical outcomes in the least restrictive settings. The early CMHO focus on prevention, coordination of services, continuity of care, and partial and residential services, as well as psychosocial and case management methodologies, underlies contemporary managed behavioral health programs. This provides CMHOs with a great opportunity to be major participants in the new programs.

Community Mental Health Services↗
PubMed1993

Ways of coping with chronic fatigue syndrome: development of an illness management questionnaire.

Chronic fatigue syndrome (CFS) is a disorder of uncertain aetiology, and there is uncertainty also about the appropriate way in which patients should manage the illness. An illness management questionnaire (IMQ) was designed to assess coping in CFS. This was completed by 207 patients, in parallel with the COPE scales (a general measure of coping that can be applied situationally), and measures of functional impairment, anxiety and depression. The IMQ yielded four factors: maintaining activity, accommodating to the illness, focusing on symptoms and information-seeking. Scales based upon these factors together predicted 26, 27 and 22% of the variance in functional impairment, anxiety and depression, respectively, and each scale had significant relationships with relevant scales of the COPE, supporting the interpretation of the factors. It is suggested that the IMQ may be employed to relate ways of coping to outcomes in CFS, and to assess coping as a mediator of change in cognitive-behavioural interventions.

Adaptation, Psychological↗
PubMed1993

Somatostatin as a modulator of distal nephron water permeability.

1. Experiments in vivo and in vitro were performed in the rat to define the role of somatostatin in modulating the hydro-osmotic action of arginine vasopressin. 2. Somatostatin had a biphasic effect on basal collecting duct diffusional water permeability with 10(-9) mol/l somatostatin producing a 14% reduction in permeability, whereas concentrations of 10(-6) and 10(-5) mol/l significantly increased basal water permeability by 13% and 22%, respectively. Somatostatin (10(-9) mol/l) also inhibited the increase in water permeability produced by arginine vasopressin, although this inhibitory effect was reduced by a 10-fold increase in arginine vasopressin concentration (5 ng/ml). 3. In the anaesthetized water-diuretic rat, low dose somatostatin (60 micrograms/h) increased free water clearance by 23% (P < 0.01), whereas increasing the somatostatin concentration (600 micrograms/h) produced a transitory 40% fall in free water clearance (P < 0.01). As in the experiment in vitro, somatostatin inhibited the action of arginine vasopressin, although a very high concentration of arginine vasopressin (250 ng/h) partly overcame this effect. 4. Glomerular filtration rate and renal electrolyte excretion (sodium, potassium, calcium, magnesium) were not altered by somatostatin, although renal inorganic phosphate excretion was increased. The papillary solute gradient was unaltered by somatostatin. 5. These results suggest that circulating somatostatin may have a physiological role in modulating distal nephron water transport with a low concentration directly inhibiting and a high concentration facilitating water transport. There is also evidence of competitive binding between somatostatin and arginine vasopressin which antagonizes the hydro-osmotic action of arginine vasopressin.

Animals↗
PubMed1993

Quality of attention in chronic fatigue syndrome: subjective reports of everyday attention and cognitive difficulty, and performance on tasks of focused attention.

Patients with chronic fatigue syndrome (also known as post-viral fatigue syndrome or myalgic encephalomyelitis) commonly report cognitive difficulties concerning attention, concentration and memory. In this study, patients were compared with matched controls on two questionnaires which assess subjective difficulties with attention and general cognitive functioning, and on two tasks requiring focused attention. Patients reported significantly greater difficulty with attention on the Everyday Attention Questionnaire and more cognitive symptoms on the Profile of Fatigue-Related Symptoms. The objective tests did not clearly indicate a deficit in patients' focused attention; patients tended to perform less well on the Embedded Figures Test and the Stroop Colour-Word Interference Test, but these differences were not significant. There was, however, evidence of psychomotor retardation, with patients having longer response times for word reading and colour naming in the Stroop test. Difficulties in interpreting findings for both subjective and objective cognitive measures are discussed.

Adult↗
PubMed1992

Illness perception and symptom components in chronic fatigue syndrome.

Two-hundred and eight patients with chronic fatigue syndrome (post-viral fatigue syndrome) completed a questionnaire which dealt both with their illness in general and with the extent to which they experienced specific symptoms. A factor analysis of the symptom data yielded four components: emotional distress; fatigue; somatic symptoms; and cognitive difficulty. Emotional disturbance is a common feature of the disorder and its role has been widely debated. When the symptom components were considered independently, fatigue, somatic symptoms and cognitive difficulty were associated with questionnaire items relating to general illness severity, but emotional distress was not. Thus negative emotions did not contribute directly to patients' perception of illness severity. They were, however, correlated with the other symptom components. It is argued that this correlation reflects a reciprocal influence, with negative emotions exacerbating fatigue and other key symptoms and the debilitating nature of these symptoms enhancing emotional vulnerability.

Activities of Daily Living↗
PubMed1992

Gut-specific and developmental expression of a Caenorhabditis elegans cysteine protease gene.

A Caenorhabditis elegans cysteine protease gene fragment, amplified by PCR using conserved eukaryotic protease gene sequences as primers, was used as a probe to isolate cDNA and genomic clones. The genomic clone, which had a coding sequence of 987 bp interrupted by 2 small introns, was physically mapped to the middle of linkage group V. The predicted amino acid sequence of the mature C. elegans cysteine protease was homologous to those of other eukaryotic cysteine proteases, particularly to that of the nematode parasite Haemonchus contortus (50%) and to the cathepsin B-like hemoglobinase of the trematode parasite Schistosoma mansoni (54%). The pro region of the C. elegans protease was homologous only to that of the H. contortus enzyme, implying a similar mechanism of protease activation. The C. elegans cysteine protease gene was temporally regulated: abundant 1.1-kb transcripts were detected in larvae and adults, but not in embryos. Transcription also was spatially regulated, occurring only in the intestine. Like the vitellogenin genes, which also are transcribed exclusively in the intestine, the 5' end of the C. elegans cysteine protease gene had at least one copy of each of 2 heptameric sequences which may be transcriptional regulatory elements governing gut-specific expression.

Amino Acid Sequence↗
PubMed1992

Positive and negative social support in a chronic illness.

A measure of social support was developed and administered to 207 patients with chronic fatigue syndrome. Positive social support was related to anxiety, and negative social support was related to both anxiety and depression.

Activities of Daily Living↗
PubMed1992

Effect of ethanol on water and chloride transport in the rat papillary collecting duct.

While it is believed that the effect of ethanol on human renal water homeostasis is indirect, amphibian membrane experiments have demonstrated direct effects albeit at high concentrations. To evaluate the direct effect of ethanol, diffusional water and chloride permeability was simultaneously measured in isolated rat papillary collecting ducts with increasing concentrations of ethanol (0, 0.12, 0.24, 0.48, 0.96 and 1.92 g%) both in the presence and absence of arginine vasopressin (AVP). Low concentration of ethanol (0.12 g%) increased basal water permeability by 9%. With increasing concentrations it then fell to control levels (0.48 g%) only to increase again with concentrations of 0.96 and 1.92 g% to a maximum increase of 26%. Similar changes in chloride permeability occurred. Water permeability in the presence of submaximal concentrations of AVP (20 microU/ml) was also significantly increased with lower concentrations of ethanol (0.12, 0.24 and 0.48 g%) but fell to control levels with higher concentrations. With the highest ethanol concentration (1.92 g%), submaximal AVP did not significantly increase water permeability. However water permeability was unaltered by increasing concentrations of ethanol in the presence of supramaximal AVP (2,000 microU/ml). These results demonstrate a direct effect of ethanol upon distal nephron water and chloride transport.

Animals↗
PubMed1991

Characterization of the alpha-2C adrenergic receptor subtype in the opossum kidney and in the OK cell line.

The alpha-2 adrenergic receptors have been subdivided into two pharmacological subtypes known as alpha-2A and alpha-2B. The OK cell, a cell line derived from an opossum kidney, expresses an alpha-2 adrenergic receptor which has pharmacological characteristics different from both the alpha-2A and alpha-2B subtypes, and thus may be a third subtype. To test this hypothesis, we compared the affinities (Ki values from radioligand binding) of 49 drugs in the OK cell with their affinity for the alpha-2A (HT-29 cells) and alpha-2B (neonatal rat lung) adrenergic receptor subtypes. Eight drugs (spiroxarine, prazosin, WY 27127, L-657,743, ARC 239, akuammigine, rauwolscine and oxymetazoline) were identified whose Ki differed by 10-fold or more between the OK cells and HT29 cells. Five drugs (BAM 1303, raubasine, WB 4101, akuammigine and rauwolscine) differentiated, by at least 10-fold, between OK cells and neonatal rat lung. Correlations of pKi values between the OK cell and tissues or cell lines expressing either the alpha-2A or alpha-2B subtypes were poor, confirming that the OK cell receptor could not be classified as either alpha-2A or alpha-2B. In contradistinction, there was a good correlation between pKi values for the OK cell line and opossum kidney showing that they express the same subtype. In addition, ratios of subtype-selective drug Ki values were similar for the OK cell and opossum kidney, but different from other tissues or cell lines expressing either the alpha-2A or alpha-2B subtypes. We conclude that the OK cell line and opossum kidney express a novel subtype of alpha-2 adrenergic receptor which we term the alpha-2C subtype.

Animals↗
PubMed1991

Synthetic human parathyroid hormone-related protein and rat renal electrolyte transport.

The effect of parathyroid hormone (PTH)-like peptide PTH-related protein (PTHrP)(1-34) from a human cancer cell line on renal electrolyte transport was compared with human PTH(1-34) in a thyroparathyroidectomized anesthetized rat model. Comparing submaximal, maximal and supramaximal phosphaturic concentrations of hPTH with the same PTHrP concentrations, no significant difference could be demonstrated in the urinary excretion of calcium, magnesium, inorganic phosphate or cAMP. Even the small (30.3%) and brief (45 min) reduction in fractional water excretion with the maximal (1 nM/kg/h) hPTH concentration was approximated by PTHrP. It is concluded that the structural homology between hPTH and PTHrP allows a similar action on renal electrolyte transport, including the partial agonist effect of higher concentrations of PTH on vasopressin-induced water transport.

Animals↗
PubMed1990

Frequency response of the peripheral sampling sites of a clinical mass spectrometer.

Mass spectrometers are used in ICUs and ORs to measure the concentration of medical and anesthetic gases gathered from multiple sites. This investigation was designed to determine the accuracy of a clinical system, which included 12 ICU bedside stations monitored by a medical mass spectrometer (Perkin-Elmer RMS III, Pomona, CA). Each site station was connected to the analyzing unit via two Teflon tubes, one permanently installed, 30-m long, and the second disposable, 2.4-m long. A gas mixture containing 95% O2 and 5% CO2, alternating with room air, was delivered to a solenoid valve and from there to the connecting tubes. Gas flow-rate, delay time, rise time, and peak and trough concentrations were determined for each gas at solenoid cycling frequencies of 25, 50, and 100/min. After the first set of measurements, the 30-m tubes were thoroughly cleaned and all measurements repeated. In addition, the authors also measured CO2 delay and rise times when the gas was delivered to the mass spectrometer through an unused 30-m tube or a new 2.4-m tube. Gas flow-rate increased from 143 +/- 12 ml/min (mean +/- SD) to 238 +/- 9 ml/min after the tubes were cleaned. Delay time was identical for all gases at all solenoid cycling rates but decreased significantly (P less than 0.05), from 11.5 +/- 0.3 to 4.8 +/- 0.7 s after the ceiling tubes were cleaned. As solenoid valve rate increased, the difference between measured and actual gas concentration increased. The lowest accuracy was 63.6 +/- 2.1%, for CO2 at 100 cycles/min.(ABSTRACT TRUNCATED AT 250 WORDS)

Gases↗
PubMed1989

The myth of the yo-yo: consistent rate of weight loss with successive dieting by VLCD.

Four subjects in a recent trial of eight weeks dieting with the 405 kcal/day, 42 g protein formula (Cambridge diet extra), had participated 18 months previously in an 8-week trial using the 330 kcal/day Cambridge diet formula. This permitted a quantitative comparison of two similar dieting episodes, but following substantial weight loss and variable weight regain after a successful experience with a very low calorie diet. Within the reasonable bounds of comparison between outpatient dieting experiences, there was no suggestion of impairment in ability to lose weight in subsequent dieting after weight loss on a VLCD. The experience of these subjects would not support the contention that lasting metabolic debilitation had occurred that could be attributed to repeated dieting experiences with VLCD.

Diet, Reducing↗
PubMed1988

An automated mechanism for protection of mass spectrometry sampling tubing.

The usefulness of medical mass spectrometers in intensive care units can be limited by too frequent obstruction of the tubing that transports gases from the patients to the analyzing unit. To overcome this problem, we developed an automated system consisting of an infrared light sensor and a three-way valve. One port of the three-way valve connects to 2.4-m disposable tubing that collects gases from the patient's airway. The second port is connected to a mass spectrometer analyzing unit through 30-m permanently installed tubing. The third port is connected to a pressurized oxygen source. An infrared light sensor is placed on the shorter tubing, between the patient and the three-way valve. When increased optical density is detected, due to entrainment of respiratory secretions, the three-way valve is activated. Gas flow is closed between the patient and the mass spectrometer and opened between the pressurized oxygen source and patient tubing to flush its contents. During the six years that the protection system has been in use, the frequency with which the disposable gas collection tubing is changed has been halved. Furthermore, periodic tests of delay and response times, performed at each bedside station, indicate that permanent connection tubing only needed cleaning at 2- to 3-year intervals. The system has decreased the cost of operating our mass spectrometers while also reducing periods of unavailability due to equipment failure.

Anesthesiology↗
PubMed1988

Capnography in mechanically ventilated patients.

Capnography, the science of CO2 waveforms analysis, can play a role in the management of mechanically ventilated patients. Mass spectrometers are the devices most commonly used to collect sequentially and examine CO2 waveforms from multiple patients in the ICU or operating rooms. We present here a review of some clinical and technical problems, which may be resolved efficiently and expeditiously through the use of mass spectrometry and capnography. Mechanical failures, especially those that lead to rebreathing of exhaled gases, can be readily detected. The patient's progress during weaning and the consequences of changes in mechanical assistance can be virtually and noninvasively determined. An expanded role of capnography in mechanically ventilated patients can increase the use of mass spectrometers in the ICU.

Carbon Dioxide↗
PubMed1988

Suppression of ctc promoter mutations in Bacillus subtilis.

Transcription from the Bacillus subtilis ctc promoter is induced as cells enter stationary phase under conditions in which the enzymes of the tricarboxylic acid cycle are repressed. This transcription requires the presence of a secondary form of RNA polymerase, E sigma B, that is found in exponentially growing cells and in early-stationary-phase cells. Starting with a defective ctc promoter that had either a base substitution at position -15 or a base substitution at position -36, we were able to identify four independent second-site mutations within these mutated promoters that suppressed the effect of the original mutations and thereby restored function to the ctc promoter. Three of these mutated promoters had an additional base substitution(s) at positions -5, -9, or both -5 and -9 that enhanced their utilization in vivo by E sigma B, whereas one of the promoters had a single-base-pair deletion in the -15 region that placed it under a completely different form of regulation than that of the wild-type ctc promoter. In addition to mutations in the ctc promoter region, we also isolated three classes of mutants that exhibited increased ctc expression. The effects of the mutations in these strains were not allele specific, since they increased expression from both mutant and wild-type ctc promoters. One class of mutants which affected expression from the ctc promoter carried mutations that blocked the activity of the tricarboxylic acid cycle. A second class of mutations mapped near cysA and was unable to sporulate. Three-factor transformation crosses and complementation analysis indicated that one of these mutations was an allele of spo0H. The third class of mutations is closely linked to dal and may define a regulatory gene for sigB, the sigma B structural gene.

Acetyltransferases↗
PubMed1987

Indirect calorimetry in the mechanically ventilated patient.

We used indirect calorimetry to measure oxygen consumption (VO2) and carbon dioxide production in 29 mechanically ventilated patients. These data were compared to VO2 measured simultaneously by a standard thermodilution technique. A good correlation was demonstrated between the methods, but VO2 measured by indirect calorimetry was 15% higher than VO2 measured by thermodilution.

Adolescent↗