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Biomedical subjects

P Gray

Publications and source records attributed to P Gray.

At least 55 records · Page 3Linked to original sources
PubMed1994

Modulation of mustard toxicity by tacrine.

Compounds containing the chloroethyl group are potent inhibitors of DNA synthesis and cell growth. Tacrine, a choline carrier inhibitor, was found to protect both HeLa cells and rat thymocytes against the effects of nitrogen mustard. DNA synthesis was restored from 13 to 71% of the control value and cell viability restored from 27 to 57% of the control value by exposure of the cells to an equimolar concentration of tacrine immediately prior to nitrogen mustard. In contrast, tacrine was unable to significantly protect rat thymocytes against the toxic effects of sulphur mustard. These results have implications for the clinical use of nitrogen mustard.

Animals↗
PubMed1994

Symptomatic relief from treatment-induced psychosis in Parkinson's disease: an open-label pilot study with remoxipride.

Current treatment strategies for levodopa-induced psychosis in Parkinson's disease have had limited success. Remoxipride, a selective D2 receptor antagonist, was administered in an open label pilot study to seven parkinsonian patients exhibiting thought disorder. Symptoms improved significantly in six patients after treatment durations of 1-6 months and cleared completely in two individuals. One patient (at age 90 the oldest in the group) could not tolerate the compound due to significant motor deterioration, and the drug had to be discontinued after 1 week. In all remaining patients, no motor complications appeared, and therapeutic effects of remoxipride continued for up to 3 months after treatment cessation and have lasted for 2 years now in one individual. Further study of this compound in the context of treatment-induced psychosis in Parkinson's disease appears to be warranted.

Aged↗
PubMed1994

Use of on-line gas analysis to monitor recombinant mammalian cell cultures.

The development of a system capable of accurately measuring the oxygen uptake and carbon dioxide production rates during mammalian cell cultures is described. A detailed study of the specifications of the various components used in the system for the measurement of gas flow rates and composition, coupled with the validation of the system independent of the bioreactor was carried out. The aim of this study was to identify and eliminate where possible the errors controlling the accuracy of determination of gaseous metabolic rates. This study showed the importance of controlling the temperature of gaseous oxygen entering the system. With such temperature control, it was possible to obtain data with an accuracy of +/- 5% at the 95% confidence level. Another source of error, the use of bi-carbonate buffer, was studied. A mathematical model was used to compensate for the affect of such buffers on the determination of carbon dioxide production rates. The use of the system for the continuous determination of gaseous metabolism during the growth and production phase for recombinant CHO cell cultures is described.

Animals↗
PubMed1994

Evaluation of the short-term impact of counseling in general practice.

This paper describes the findings of a randomised controlled trial of the short-term impact of counseling in the general practice setting. Compared with patients who received usual advice from their general practitioner for acute problems such as relationship difficulties, anxiety and depression, those who received counseling from qualified counselors working within the primary health care context showed greater improvement in psychological health as measured by the General Health Questionnaire. Significantly fewer of those counselled were prescribed anti-depressant drugs by the general practitioners in the study, or were referred to psychiatrists or clinical psychologists for care. In addition those patients who attended sessions with the practice counselor were more likely to report that they were satisfied with their treatment and more expressed feelings of well-being.

Adult↗
PubMed1994

Thermogenic, hormonal, and metabolic effects of a TPN mixture. Influence of glucose and amino acids.

The thermogenic, hormonal, and metabolic effects of intravenous nutrition were examined by administering a complete total parenteral nutrition (TPN) mixture to 11 subjects, and the relative contributions of the glucose and amino acid components of the mixture were evaluated by administering these nutrients separately (n = 7 and n = 6, respectively). The complete TPN mixture caused a 22.9% rise in resting energy expenditure (REE), which significantly exceeded that associated with glucose (10.4% P < 0.02). The rise in REE produced by the amino acids (11.5%) did not differ significantly from that associated with administration of the TPN or glucose. The rise in REE associated with the TPN was almost exactly equal to the sum of the rises associated with the separate components of the mixture (22.9% and 22.0%, respectively), indicating that glucose and amino acids contributed equally to the thermogenic effect of the TPN mixture. In contrast, although the amino acid component of the TPN mixture was associated with small but significant reductions in plasma free fatty acid and glycerol concentration and with small increases in plasma insulin concentration, the effects of the complete TPN mixture were significantly greater and attributable to the glucose component.

Adult↗
PubMed1994

Total parenteral nutrition modifies the acute phase response to Crohn's disease.

Measurements of the acute phase proteins, C-reactive protein (CRP) and orosomucoid are widely used to monitor the activity of Crohn's disease. The effect of TPN upon the levels of acute phase proteins is unknown. Serum levels of CRP and orosomucoid were measured simultaneously over a four year period in 13 patients receiving TPN for Crohn's disease, nine patients with noninflammatory causes of intestinal failure, and 16 patients with Crohn's disease treated without TPN. An acute phase response was found with a similar frequency in both groups of patients with Crohn's disease (73.6% and 83.9% for Crohn's with and without TPN respectively), but was less prevalent in patients receiving TPN for non-inflammatory causes of intestinal failure (56.1%, P < 0.01). In this latter group, the acute phase response consisted primarily of an isolated elevation of orosomucoid (78.4%), compared with patients with Crohn's disease alone (21.1%, P < 0.001) and with Crohn's disease and TPN (46.6%, P < 0.05). Liver function abnormalities were seen on 68.8% of occasions in patients with noninflammatory causes of intestinal failure who had elevated levels of orosomucoid, compared with 34.9% of occasions on which orosomucoid levels were normal (P < 0.001). TPN may lead to isolated elevation of serum levels of orosomucoid, reducing the value of this acute phase protein in monitoring the activity of Crohn's disease in patients receiving TPN.

Acute-Phase Proteins↗
PubMed1994

Excessive infant crying: a controlled study of mothers helping mothers.

OBJECTIVE: To determine the efficacy of behavioral management counseling in the treatment of persistent, excessive infant crying (> 3 hours per day). DESIGN: Two treatments, one no treatment control group. Infants were group-matched according to baseline fuss/cry levels, sociodemographic, and infant variables. Treatments were carried out sequentially by the same counselors. SETTING: Telephone counseling by volunteers (mothers) of CRY-SIS, a national support group for the parents of crying infants. PATIENTS AND INTERVENTIONS: Sequential sample of 27 mother-infant pairs receiving treatment 1 (Tr1, empathy: talking through the problem), 21 receiving treatment 2 (Tr2, behavioral management: specific care taking suggestions) and 44 receiving no treatment (C, controls). Infants were between 1 to 5 months of age. MEASUREMENTS AND RESULTS: Mother-infant pairs had a pretreatment baseline assessment and a posttreatment follow-up (3 months after baseline) using 1-week diaries. Total fuss/cry duration reduced significantly more in the behavioral management group (by 51%) than the empathy group (37%) or the control group (35%). This was mainly due to significantly reduced evening fussing/crying in Tr2 (67%) compared with Tr1 (45%) and C (42%). No differences in total number of fuss/cry bouts/day were found. However, the number of fuss/cry bouts reduced significantly more in the evening in Tr2 (by 55%) compared with Tr1 (27%) and C (32%). Behavioral management mothers evaluated the same counselors as more sympathetic, knowledgeable, and understanding. Tr2 was also perceived by mothers to have helped them more in reducing the crying problem, coping with the infant, and improving the relationship with their infant than Tr1. No effects of treatment on infant difficult temperament were found. CONCLUSIONS: Behavioral management was more effective in reducing fussing/crying than spending time with the mother talking through the problem or just waiting for spontaneous remission. Treatment by suitably but briefly trained lay counselors is an inexpensive and successful treatment option.

Adaptation, Psychological↗
PubMed1993

Individualizing aminophylline doses in premature infants using bioelectrical impedance: a non-invasive approach.

The role of bioelectrical impedance (BI) in estimating the pharmacokinetics and, therefore, individualized doses, of aminophylline in preterm infants (gestational age 26-35 weeks) was assessed in a two-phase study. Multiple regression analysis in the first group of neonates (phase I, n = 19) identified resistance, reactance, weight and length as optimal predictors of distribution volume (adjusted R2 = 0.84, coefficient of variation (CV) = 10.17%), and length2/impedance and postconceptual age as predictors of clearance (adjusted R2 = 0.74, CV = 26.73%). Application of these models to an independent group (phase II, n = 20) generated doses which satisfactorily achieved target theophylline loading and steady-state (SS) 'peaks' of 10 micrograms/mL and SS 'troughs' of 7.7 +/- 0.6 micrograms/mL. A better understanding of specific criteria and limitations of the impedance technique in neonates is necessary in order to refine BI measurements.

Aminophylline↗
PubMed1993

Exercise conditioning in older coronary patients. Submaximal lactate response and endurance capacity.

BACKGROUND: Older coronary patients are at high risk of cardiac disability. Exercise conditioning programs have been demonstrated to improve functional capacity, particularly in younger coronary patients. In this study, the effects of aerobic conditioning on submaximal and maximal indicators of exercise performance were examined in 45 older coronary patients. METHODS AND RESULTS: Forty-five patients (mean age, 69 +/- 6 years; range, 62 to 82 years) entered 3-month and 12-month (n = 11) endurance training programs. Training effects were assessed during an exhaustive submaximal exercise protocol with measurement of endurance time, serum lactate, perceived exertion, and expired ventilatory measures. Exhaustive endurance time increased by more than 40% (30 +/- 10 to 41 +/- 10 minutes), with associated decreases in serum lactate, perceived exertion, minute ventilation, heart rate, and systolic blood pressure during steady-state exercise. Respiratory exchange ratio during steady-state exercise, an indicator of substrate utilization, decreased, indicating a shift toward greater use of free fatty acids as a metabolic fuel. In a subset of 10 patients, percent body fat was decreased (32 +/- 8% to 29 +/- 10%) over a period of 3 months. CONCLUSIONS: Older coronary patients respond to aerobic conditioning with remarkable improvements in submaximal endurance capacity, out of proportion to the more modest increases in VO2max. Activities that were exhaustive before training became sustainable for extended periods of time at a lower perceived exertion. Measurements of serum lactate, respiratory exchange ratio, and ventilation during steady-state exercise document that at an identical absolute work load after conditioning, exercise is performed using aerobic substrate to a greater degree, and ventilatory response to a given work load is lessened.

Aged↗
PubMed1992

Correspondence.

Explore the source record for details and available documents.

Letter↗
PubMed1992

Value of postprocedural chest radiographs in the adult intensive care unit.

OBJECTIVE: To evaluate the necessity for postprocedural chest radiographs after catheterization of central veins, insertion of pulmonary artery catheters, and placement of endotracheal tubes. DESIGN: Prospective, controlled study. SETTING: Two academic tertiary adult ICUs. PATIENTS: Consecutive patients (n = 316) requiring central vein cannulation or endotracheal intubation in the ICUs. INTERVENTION: After each invasive procedure, the physician was instructed to complete a detailed evaluation sheet. Criteria based on the details of the procedure and immediate postprocedural clinical evaluation of the patient were used to determine the likelihood of a radiologically detectable complication. Actual radiologic findings were subsequently compared against clinical predictions. MAIN OUTCOME MEASUREMENTS: Ability of housestaff to correctly predict the absence of radiologically detectable postprocedural complications (predictive negatives). RESULTS: Ability to predict the absence of complications after cordis catheter insertions via the subclavian vein or internal jugular vein was very high (151/152; p < .001). Unsuspected complications were more frequent with central vein multilumen catheter insertions (3/24; p < .001). Ability to predict uncomplicated pulmonary artery catheterization was also high (110/111; p < .001). Physicians were unable to predict the majority of complications associated with endotracheal intubations (28/32; p > .50). CONCLUSIONS: The use of a protocol that includes an evaluation of the characteristics of the procedure and postprocedural physical examination can greatly reduce the need for routine chest radiographs after subclavian and internal jugular vein cordis catheterizations and pulmonary artery catheter placement. Chest radiographs should be performed after endotracheal intubation and multilumen catheter insertion.

Catheterization, Central Venous↗
PubMed1992

Thermogenic and hormonal responses to amino acid infusion in septic humans.

Metabolic effects of a commercially available amino acid infusate were investigated in five preoperative patients with abdominal sepsis and five healthy subjects. Oxygen consumption (VO2) was measured continuously during the 3-h study, and blood samples were taken regularly for hormone and metabolite analyses. During 1 h of preinfusion measurements, VO2 was 15% higher (P less than 0.05) in the septic patients. Preinfusion plasma cortisol, glucagon, and catecholamines were also significantly elevated in the septic group. The amino acid solution (9 g nitrogen; 950 kJ; 227 kcal) was infused into each subject through their central venous catheter during the 2nd and 3rd h of the study. VO2 increased similarly in both groups by approximately 21% during the infusion (P less than 0.05), whereas respiratory quotient increased significantly in only the controls (P less than 0.05). Plasma insulin and glucagon concentrations rose significantly in both groups during the infusion, despite little change in glucose levels. Plasma norepinephrine increased in both groups, although the response was significant in only the control subjects. In summary, the amino acid infusate stimulated metabolic rate similarly in the septic and nonseptic subjects.

Amino Acids↗
PubMed1992

Memory as resistance, and the telling of a dream.

Traditional analytic orientation to memory as subject to repression has overshadowed examination of some of the ego's other activities bearing on memory. The author examines the defensive use of memory with the analytic goal of maximum autonomous access for the patient to the ego's previously unconscious management of intrapsychic conflict. A close scrutiny of an example of this in the form of the telling of a dream explores this resistance process and illustrates a technical approach. Some aspects of this perspective are considered in relation to traditional approaches to dream material. Certain technical priorities for differing clinical settings are discussed.

Adult↗
PubMed1991

The effects of systematic errors on the analysis of irreversible enzyme inhibition progress curves.

The effects of errors in Km and Vmax. on the determination of the kinetic constants for the irreversible inhibition of acetylcholinesterase were determined. The results show that small errors in the values of Km and Vmax. give rise to large errors in the fitted parameters k2 and Kd. The problem may be minimized for multiple progress curves by selecting an appropriate number and distribution of inhibitor concentrations.

Acetylcholinesterase↗
PubMed1991

An unusual case of traumatic haematoma of soft palate.

Ingestion of small bones often causes oropharyngeal trauma. I present an unusual case of a potentially life-threatening haematoma of the soft palate caused by a chicken bone. To my knowledge, this is the only case reported in the English literature.

Female↗