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S Harwood

Publications and source records attributed to S Harwood.

14 recordsLinked to original sources
PubMed2000

Analysis of human ouabainlike compound by micellar electrokinetic chromatography.

In this preliminary study we have optimised micellar electrokinetic chromatography (MEKC, a form of capillary electrophoresis) to enable the chromatographic and spectral characteristics of human ouabainlike compound (OLC) to be investigated. Sera from fifty patients were combined to form a pool (100 ml) whilst urine (92.5 ml) was obtained from a normal healthy volunteer. Both samples were initially concentrated and partially purified by solid phase extraction before further purification by sequential HPLC separations. Final volumes for both extracts were 100 microl. MEKC was performed on a HP(3D) CE instrument with voltage set at 20 KV, capillary temperature at 20 degrees C, injection time 4 s, sample volume 10 nl, with detection by photodiode array. A compound was found in both serum and urine that had similar elution and spectral characteristics to authentic ouabain. We conclude that MEKC is potentially a useful tool for the analysis of human OLC.

Cardenolides↗
PubMed1997

Development of enzyme immunoassay for endogenous ouabain-like compound in human plasma.

Widespread evidence supports the existence of an endogenous digitalis-like compound in mammals. We report here the development of a novel enzyme immunoassay for ouabain that, in conjunction with a detailed HPLC study, identifies a ouabain-like compound (OLC) in extracted human plasma. The assay is sensitive-minimum detection limit for OLC 37 pmol/L (11 pmol/L in plasma)-and has a working range (between-assay CV < 10%) of 180-10000 pmol/L (54-3000 pmol/L in plasma). Mean recoveries of ouabain added to plasma ranged from 90% to 100%, and plasma extracts diluted in parallel to the standard curve. Plasma OLC concentrations in 10 healthy volunteers averaged 92 pmol/L (range 55-168), assuming 100% cross-reactivity of OLC in the ouabain assay. HPLC analysis with two distinct chromatographic conditions demonstrated that endogenous human plasma OLC co-eluted with authentic ouabain. The enzyme immunoassay is rapid and easy to perform and will support further investigation of the nature of this controversial endogenous steroid.

Chromatography, High Pressure Liquid↗
PubMed1997

Anaphylaxis.

Explore the source record for details and available documents.

Adult↗
PubMed1995

Effect of diabetes and peritonitis on the peritoneal equilibration test.

Peritoneal equilibration tests (PET) were performed on 47 patients (15 diabetics) who had been on CAPD for 1 to 112 months. Among new patients on CAPD (1 to 3 months) with no history of peritonitis, diabetics had higher D/PCr than non-diabetics (P < 0.02). However, after > or = 7 months of CAPD, in patients with < or = 2 episodes of peritonitis, glucose and creatinine transport rates were lower (P < 0.05) in diabetic than non-diabetic patients. Among patients on CAPD for > or = 7 months, creatinine (P < 0.05) and glucose transport (P < 0.01) were higher in patients with a history of > or = 3 episodes of peritonitis than in those with < or = 2 episodes. Drain volumes did not differ between any of the subgroups (all P > 0.05). The observations in patients newly established on CAPD were substantiated in a larger study of 55 non-diabetic and 35 non-insulin dependent diabetic patients. D/D0 glucose correlated with plasma glucose (r = 0.40, P < 0.02) in the diabetic group. Net ultrafiltration was reduced in hyperglycemic (P = 0.022) but not normoglycemic diabetics (non-diabetics 231 +/- 167 ml, hyperglycemic diabetics 127 +/- 177 ml, normoglycemic diabetics 238 +/- 159 ml). Creatinine clearance was higher in normoglycemic (P = 0.02) but not hyperglycemic diabetics (non-diabetics 6.8 +/- 0.9 ml/min, hyperglycemic diabetics 6.9 +/- 0.8 ml/min, normoglycemic diabetics 7.4 +/- 0.7 ml/min). These data show that diabetes and peritonitis incidence should be borne in mind when interpreting results of the PET.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Determinants of low systemic vascular resistance during cardiopulmonary bypass.

Although low systemic vascular resistance occurs during normothermic and hypothermic cardiopulmonary bypass, the determinants of depressed systemic vascular resistance and its effect on outcomes are unknown. To assess the predictors and clinical effects of low systemic vascular resistance, 555 patients undergoing isolated coronary artery bypass grafting were evaluated prospectively. The extent of low systemic vascular resistance during bypass was estimated by the amount of the vasoconstrictor phenylephrine administered: group 1, 0 to 160 micrograms; group 2, 161 to 800 micrograms; group 3, more than 800 micrograms. Multivariate analysis identified bypass temperature, bypass time, and ventricular function as determinants of low systemic vascular resistance. Patients on normothermic bypass accounted for 65% of the patients in group 3 and only 34% of the patients in group 1 (p < 0.0001). The bypass time was longer in the patients in group 3 (97 +/- 28 minutes) than in the patients in group 1 (89 +/- 24 minutes; p < 0.006). Patients with a preoperative left ventricular ejection fraction of 0.40 or less required less phenylephrine during cardiopulmonary bypass (498 +/- 68 micrograms) than did patients with a fraction exceeding 0.40 (1,087 +/- 88 micrograms; p < 0.001). By multivariate analysis, advanced age and the presence of peripheral vascular disease were found to decrease the likelihood of low systemic vascular resistance during normothermic bypass. Diabetes, the left ventricular ejection fraction, the bypass time, and the total cardioplegia infused were found to influence the likelihood of low systemic vascular resistance during hypothermic bypass. Patients in group 3 had a higher cardiac index and lower-mean arterial pressure and systemic vascular resistance postoperatively. In those patients who received a left internal mammary artery graft, the incidences of the low-output syndrome (group 1, 4.9%; group 3, 2.7%; p = not significant) and myocardial infarction (group 1, 1.4%; group 3, 1.8%; p = not significant) were not influenced by the amount of phenylephrine infused during cardiopulmonary bypass. In those patients who were at high risk of suffering a stroke preoperatively, the hypotension induced by the low systemic vascular resistance and its treatment with phenylephrine was not associated with an increased incidence of stroke (group 1, 5.8%; group 3, 2.8%; p = not significant).

Aged↗
PubMed1993

A trial of two cognitive behavioural methods of treating drug-resistant residual psychotic symptoms in schizophrenic patients. II. Treatment-specific changes in coping and problem-solving skills.

Changes in coping skills and problem-solving skills were examined in two groups of schizophrenic patients. The groups received either coping skills enhancement or problem-solving treatments to reduce their drug-resistant residual psychotic symptoms. The coping skills group showed significant increases both in the number of positive coping strategies used and in their efficacy, whereas the problem-solving group showed a decrease in these measures during treatment. Both groups showed significant improvements in problem-solving skills. Changes in coping but not problem solving were significantly related to decreases in psychotic symptoms during treatment. It was concluded that treatment involving the teaching of coping skills had a specific treatment effect.

Adaptation, Psychological↗
PubMed1993

A trial of two cognitive-behavioural methods of treating drug-resistant residual psychotic symptoms in schizophrenic patients: I. Outcome.

Despite neuroleptic medication, many schizophrenic patients continue to experience residual positive psychotic symptoms. These residual symptoms cause distress and disability. We report a controlled trial of two cognitive-behavioural treatments to alleviate residual hallucinations and delusions. Forty-nine patients were recruited into the trial, of whom 27 entered the trial and completed post-treatment assessment, and 23 were reassessed at six-month follow-up. Patients were randomly allocated to either coping strategy enhancement (CSE) or problem solving (PS). Half the patients were allocated to a high-expectancy positive demand condition and half to a counter-demand condition to evaluate expectation of improvement. Patients receiving either cognitive-behavioural treatment showed significant reductions in psychotic symptoms compared with those in the waiting period, who showed no improvement. There was some evidence, although equivocal, that patients receiving CSE improved more than those receiving PS. There was no evidence that improvements generalised to negative symptoms or social functioning, nor was there evidence that expectancy of treatment benefit contributed to the treatment effect.

Activities of Daily Living↗
PubMed1985

Antiemetic efficacy of levonantradol compared to delta-9-tetrahydrocannabinol for chemotherapy-induced nausea and vomiting.

The antiemetic efficacy of im levonantradol, a synthetic cannabinoid, given at a dose of 1 mg every 4 hours, was compared to oral delta-9-tetrahydrocannabinol (THC) given at a dose of 15 mg every 4 hours in a double-blind crossover study. Twenty-six patients receiving emetogenic cancer chemotherapy were evaluated. For each drug, 28% of treated patients had no nausea. The median number of emetic episodes with levonantradol was 2.0 versus 3.0 for THC (P = 0.06). Side effects occurred in 91.7% and 97.3% of levonantradol and THC patients, respectively, with drowsiness and dizziness most commonly seen. Side effects were generally well-tolerated, with only 13.9% of levonantradol and 21.6% of THC patients discontinuing treatment because of side effects. Levonantradol appears to be at least as effective an antiemetic as THC and is the only cannabinoid available for parenteral use.

Adult↗
PubMed1983

Delayed hypersensitivity skin testing as a prognostic indicator in patients with small cell lung cancer.

The prognostic importance of pretreatment delayed hypersensitivity skin test reactivity was determined in 154 newly diagnosed, carefully staged and aggressively treated small cell lung cancer patients. One hundred twenty-one patients were reactive to at least 1 of 5 skin test antigens and 33 were anergic. Skin test reactive patients survived significantly longer than anergic patients. This result was expected since there was a significant trend for reactive patients to have good performance status (P = 0.005) and low tumor burden (P = 0.005) compared to anergic patients. The principal finding of this study was that skin test reactivity was of prognostic utility primarily in otherwise good prognosis patients, i.e., individuals with good performance status and low tumor burden. In this group anergy was associated with significantly shortened survival (P = 0.025). In poor prognosis (poor performance status and high tumor burden) or intermediate prognosis (either poor performance status or high tumor burden) patients skin test reactivity or anergy had no significant influence on survival.

Adult↗
PubMed1977

Systolic honks in young children.

Three children with loud systolic honks were studied noninvasively with phonocardiography and echocardiography. It was shown that the precordial honk, like the late systolic mitral murmur and the clicking apical systolic sound, is part of a continuum of auscultatory sounds that result from a defect of mitral valve support and are classified under the general heading of mitral valve prolapse syndrome. Prolapse of one or both of the mitral valve leaflets is believed to cause the characteristic auscultatory findings of click, murmur or honk. The timing of these sounds in systole varies with different physiologic or pharmacologic maneuvers. Variations in the onset of prolapse are associated with changes in left ventricular end-diastolic dimensions.

Adolescent↗
PubMedDate not supplied

A new sterile bicarbonate dialysis solution for use during cardiopulmonary bypass.

Adding a dialysis filter to the perfusion circuit at the end of cardiopulmonary bypass (CPB) has become an accepted means of reducing potassium rapidly and safely. Rapid removal of solute requires a dialysate for diffusion, and peritoneal dialysis solutions have been the standard because of availability, although occasionally normal saline or bicarb/ saline mixtures are used. Cardioplegia solution is high in glucose as well as potassium and, with many diabetic patients undergoing CPB, it is desirable to minimize glucose loads. In this prospective cohort study, six patients received a commercially available sterile bicarbonate dialysate prepared in a point of care fashion. From the cardiovascular data base, four control patients (receiving lactate based dialysis solution during CPB) were matched for age, surgery type, body surface area (BSA), and pump duration for each of the six patients receiving bicarbonate dialysate. All of the control patients were dialysed against lactate buffered peritoneal dialysis solution. Plasma levels of potassium, glucose, and bicarb were measured before and after dialysis for each dialysate. Plasma potassium, glucose, and bicarb were not significantly different at start of dialysis. The lactate dialysate (LD) group received a mean of 17.4+/-7.7 L of lactate containing dialysate versus 14.6+/-4.7 L of bicarbonate dialysate (BD) (p = 0.41). After dialysis, potassium had been reduced to a similar degree in both groups, but plasma glucose levels had increased during LD while they fell during BD, and bicarbonate levels fell during LD while they rose during BD. Use of a commercially available sterile bicarbonate dialysate can safely help to lower plasma potassium during CPB and preserve more physiologic levels of glucose and bicarbonate.

Acidosis↗
PubMedDate not supplied

Release of ouabain-like compound (OLC) from the intact perfused rat adrenal gland.

The present study was designed to investigate the effect of ACTH on release of OLC from the intact isolated rat adrenal, perfused in situ. OLC was measured by EIA. The limit of detection of the assay was 23 pmol/10 minutes. Basal levels of OLC varied from 240 to <23 pmol/10 min. Basal corticosterone levels were generally higher than OLC while aldosterone were generally lower. In 3 of the 5 perfusions the addition of ACTH was followed by rapid increases in both OLC and corticosterone secretion rates within 10 minutes of stimulation. Stimulated levels of OLC were 2 to 4-fold and of corticosterone were 3 to 7-fold those found in basal samples. OLC was found to co-elute with authentic ouabain under isocratic HPLC analysis whilst perfusion medium itself contained no detectable OLC immunoreactivity. These preliminary data suggest that the intact perfused rat adrenal preparation is a useful model for investigating the acute regulation of OLC secretion.

Adrenal Glands↗