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C Ray

Publications and source records attributed to C Ray.

At least 19 recordsLinked to original sources
PubMed1994

Trans-splicing of a Meloidogyne incognita mRNA encoding a putative esophageal gland protein.

A monoclonal antibody, 7A9, specific for antigens in the subventral esophageal glands of adult female Meloidogyne incognita and for antigens in the longitudinal muscles of second-stage juveniles, was used to isolate a clone from a M. incognita cDNA expression library. The corresponding genomic DNA was isolated by hybridization and the gene designated sec-1. DNA sequence analysis of sec-1 revealed the presence of 9 introns having structural similarities to introns from the free-living nematode Caenorhabditis elegans. The sec-1 message was also trans-spliced and the leader sequence differed in one position from the sequence of the C. elegans trans-spliced leader SL1. Sequences analogous to sec-1 were specific to the genus Meloidogyne, and regulation of sec-1 expression did not involve differences in overall rates of transcript accumulation. The deduced amino acid sequence of the protein encoded by sec-1 had some similarities to the rod portions of several myosin heavy chains.

Amino Acid Sequence↗
PubMed1994

Epidermal growth factor inhibits large granulosa cell apoptosis by stimulating progesterone synthesis and regulating the distribution of intracellular free calcium.

The initial study was designed to determine whether all granulosa cells (GCs) undergo apoptosis in vitro. GCs were isolated from immature rat ovaries and separated on a 15-45% Percoll gradient. Twelve fractions were collected, and GCs were pooled according to size: small GCs (approximately 50 mu 2; fractions 2-5) and large GCs (> or = 75 mu 2; fractions 6-8). GCs were cultured in serum-free medium for 24 h. After 24 h of culture, fragmented DNA, detected by in situ end labeling of the 3'OH ends of DNA fragments, was observed within 70-80% of large GCs. Similarly, in situ DNA staining demonstrated that at least 50% of large GCs possessed apoptotic nuclei. These degenerative changes in DNA were observed within < or = 5% of small GCs. These studies demonstrate that in serum-free medium, most large GCs die via an apoptotic mechanism within 24 h. Subsequent studies focused on the mechanism by which epidermal growth factor (EGF) inhibits large GC apoptosis. EGF reduced the percentage of large GCs with apoptotic nuclei from 47 +/- 1% for controls to 18 +/- 2% (p < 0.05). EGF also increased progesterone (P4) secretion from large GCs (6.3 +/- 0.7 for controls vs. 18.7 +/- 1.0 ng/ml for EGF treatment; p < 0.05). The effect of EGF on apoptosis was mimicked by P4 and attenuated by the P4 antagonist, RU 486, and aminoglutethimide (AG), an inhibitor of P4 synthesis. The effect of AG was overridden by P4. Therefore, EGF reduces large GC apoptosis by stimulating P4 synthesis, with P4 mediating its action through its receptor.(ABSTRACT TRUNCATED AT 250 WORDS)

Aminoglutethimide↗
PubMed1994

The effect of adrenalectomy on water permeability in rat papillary collecting duct.

1. Chronic adrenal insufficiency impairs maximal urine concentration, probably in part due to reduced medullary tonicity but also possibly by inhibition of distal nephron water transport. This latter defect has been demonstrated in rabbit but not in rat. 2. Since the time between adrenalectomy and experiment was different in rabbit and rat studies, diffusional water permeability was evaluated in the papillary collecting duct in the absence and presence of submaximal (20 microU/mL) and supramaximal (200 microU/mL) arginine vasopressin (AVP) in adrenalectomized rats at 7, 14 and 21 days. 3. Experimentation 7 days after adrenalectomy failed to demonstrate significantly altered basal or AVP-induced water permeability which increased by 23 and 78% with submaximal and supramaximal concentrations, respectively. Submaximal AVP concentrations also induced a comparable change in water permeability in adrenalectomized rats at 14 days; however, 21 days after adrenalectomy, diffusional water permeability was not increased by 20 microU/mL AVP (3.31 +/- 0.22 to 3.31 +/- 0.24 microns/s). Nevertheless, the effect of a supramaximal AVP concentration (200 microU/mL) was not altered by adrenalectomy (4.54 +/- 0.39 to 8.08 +/- 0.96; P < 0.01). Incubation of collecting ducts in aldosterone for 2 h did not reverse the inhibitory effect of chronic adrenalectomy on AVP-stimulated water transport. 4. These studies suggest that mineralocorticoid withdrawal does impair the hydro-osmotic action of AVP in the rat papillary collecting duct but that this effect takes between 14 and 21 days to occur.

Adrenal Glands↗
PubMed1994

Accuracy of reported family history of heart disease: the impact of 'don't know' responses.

BACKGROUND: Usual 'Yes/No' definitions of a family history of heart disease do not allow for 'Don't know' responses. In some families, misclassification of family history may result if these are not considered. AIMS: To study the accuracy of family history reporting and the impact of 'Don't know' responses. METHODS: We compared reported family history of coronary heart disease (CHD) and cancer among 360 deceased relatives of 59 probands with 'gold standard' diagnoses recorded on official death certificates. RESULTS: For first degree relatives, sensitivity of reporting was 81% for CHD, 86% for any heart disease and 60% for cancer, while for second degree relatives, sensitivity was 73%, 69% and 90%, respectively. When 'Don't know' responses were classified as 'No', sensitivity in first degree relatives was not affected, but in second degree relatives, it fell to 49%, 41% and 60%, respectively. Specificities were unchanged. These data show that in families where information beyond first degree relatives is considered, failing to account for 'Don't know' responses is likely to lead to misclassification of family history of CHD.

Adult↗
PubMed1993

Birth weight from pregnancies dated by ultrasonography in a multicultural British population.

OBJECTIVE: To produce standard curves of birth weight according to gestational age validated by ultrasonography in the British population, with particular reference to the effects of ethnic origin. DESIGN: Retrospective analysis of computerised obstetric database. SETTING: Three large maternity units associated with Nottingham University with over 16,000 deliveries a year. PATIENTS: 41,718 women with ultrasound dated singleton pregnancies and delivery between 168 and 300 days' gestation. MAIN OUTCOME MEASURES: Length of gestation, ethnic origin, parity, maternal height and weight at booking, smoking during pregnancy; the effect of these variables on birth weight. RESULTS: Birth weights from ultrasound dated pregnancies have a higher population mean and show less flattening of the birthweight curve at term than those of pregnancies dated from menstrual history. Significant differences were observed in mean birth weights of babies of mothers of European origin (3357 g), of Afro-Caribbean origin (3173 g), and from the Indian subcontinent (3096 g). There were also significant interethnic differences in length of gestation, parity, maternal height, booking weight, and smoking habit which affected birth weight. The ethnic differences in birth weight were even greater when the effect of smoking was excluded. CONCLUSIONS: Birthweight standards require precise dating of pregnancy and should describe the population from which they were derived. In a heterogeneous maternity population the accurate assessment of an individual baby's weight needs to take the factors which affect birthweight standards into consideration.

Birth Weight↗
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↗