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Biomedical subjects

R H Taylor

Publications and source records attributed to R H Taylor.

At least 73 records · Page 4Linked to original sources
PubMed1991

Minimum alveolar concentration of desflurane and hemodynamic responses in neonates, infants, and children.

We sought to determine the minimum alveolar concentration (MAC) and hemodynamic responses to desflurane in 72 fasting and unpremedicated full-term neonates, infants, and children up to 12 yr of age. The patients were divided into six groups (n = 12) according to age. After awake tracheal intubation, neonates were anesthetized with desflurane in oxygen and air. Infants greater than 1 month of age and all older children were anesthetized with desflurane in 100% oxygen, and their tracheas were intubated without muscle relaxation. MAC was determined using the "up-and-down technique" and logistic regression. Heart rate and systolic arterial pressure were recorded awake, at approximately 1 MAC desflurane before skin incision and at approximately 1 MAC during the peak hemodynamic responses to skin incision. We found that the relationship between MAC (mean +/- standard deviation) as determined by the up-and-down technique and age was quadratic, reaching a maximum value in infants 6-12 months of age: in neonates 0-1 month MAC was 9.16 +/- 0.02%, in infants 1-6 months 9.42 +/- 0.06%, in infants 6-12 months 9.92 +/- 0.44%, in children 1-3 yr 8.72 +/- 0.59%, in children 3-5 yr 8.62 +/- 0.45%, and in children 5-12 yr 7.98 +/- 0.43%. MAC values obtained using logistic regression were similar. Heart rate decreased an average of 16% before skin incision in infants 6-12 months of age and children 1-3 and 3-5 yr of age when compared to awake values (P less than 0.025) but did not change significantly in the remaining three groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1991

The use of tinted glasses in childhood migraine.

20 children with clinically diagnosed migraine were asked to wear either a rose coloured tint or density matched blue tint for a period of 4 months. The frequency, duration and intensity of migraine attacks were recorded, together with the amount of visually provoked beta activity in the EEG. After one month's wear all the children in the study revealed an initial improvement in headache frequency. However, only those children wearing rose tints sustained this improvement up to 4 months, when the mean headache frequency had improved from 6.2 per month to 1.6 per month. The headache frequency of those children wearing blue tints revealed no overall improvement after 4 months. The improvements in headache frequency in children wearing rose tints correlated with a reduction in visually provoked beta activity.

Adolescent↗
PubMed1991

Cerebral hemodynamics in neonates and infants undergoing cardiopulmonary bypass and profound hypothermic circulatory arrest: assessment by transcranial Doppler sonography.

Profound hypothermic circulatory arrest (PHCA) is followed by a transient period of increased intracranial pressure and a longer period of neurophysiologic dysfunction. To investigate the effect of cardiopulmonary bypass (CPB) with PHCA on cerebral hemodynamics, we used transcranial Doppler sonography to measure cerebral blood flow velocity in 10 neonates and infants before and after PHCA. Cerebral blood flow velocity was compared before and after PHCA during normothermic cardiopulmonary bypass at the same mean arterial pressure, central venous pressure, hematocrit, and arterial carbon dioxide tension. Cerebral blood flow velocity decreased exponentially with decreasing nasopharyngeal temperature before PHCA (P less than 0.05) and remained decreased after PHCA during normothermic CPB, compared with values for normothermic CPB before PHCA (P less than 0.005). During normothermic CPB after PHCA, the modified cerebral vascular resistance (mm Hg.cm.s-1) was increased above values for normothermic CPB before PHCA (P less than 0.05). The results of this study suggest that the observed increase in intracranial pressure during PHCA is not caused by increased cerebral perfusion, but rather that cerebral perfusion is reduced in response to a decreased demand for cerebral metabolic oxygen.

Cardiopulmonary Bypass↗
PubMed1991

Macrophotography of the eyes: a technique for eyelid retraction.

It is important when photographing ocular movements or the bulbar conjunctiva that the full visualizations of the eye positions can be seen. This will require the upper eyelids to be retracted. The most common method is the use of fingers to retract the eyelids. A much improved technique is described using either cotton wool buds or orange sticks. It is simple and painless and makes the photographs superior in quality.

Eye Diseases↗
PubMed1988

Ultrasound assessment of the suspected scaphoid fracture.

A prospective study of 111 patients thought to have sustained a recent scaphoid fracture on clinical grounds but who were radiologically negative was undertaken over a period of 7 months. All such patients were subjected to ultrasound scanning within a week of their injury under double blind conditions. All patients were re-X-rayed 2-3 weeks after their injury. The authors' results suggest that ultrasonic diagnosis of the possibly fractured scaphoid is unreliable.

Adolescent↗
PubMed1988

Manipulation of gut hormone response to food by soluble fiber and alpha-glucosidase inhibition.

Preliminary data indicated that viscous fiber (guar) and alpha-glycosidase inhibition (acarbose) used in combination to slow carbohydrate absorption have an apparently additive effect in reducing the postprandial glycemic response. The full endocrine data reported here also demonstrate that reductions in insulin and gastric inhibitory polypeptide are most significant when guar and acarbose are used in combination. The results are divergent for enteroglucagon when guar and acarbose were given singly. Raised enterglucagon levels seen after acarbose are in keeping with inhibition of proximal absorption resulting in more distal absorption of carbohydrate. However, with viscous fiber, the enteroglucagon response was reduced, and this reduction was maintained even after addition of acarbose. The results demonstrate that the gut endocrine response can be manipulated by pharmacological interventions which alter the pattern of carbohydrate absorption.

Acarbose↗
PubMed1987

Effect of modifying the rate of digestion of a food on the blood glucose, amino acid, and endocrine responses in patients with cirrhosis.

To see whether foods with slower rates of digestion may benefit the metabolic abnormalities seen in cirrhosis, the same food, processed in two different ways, was fed to seven patients with cirrhosis. The breakfast of lentils processed by prolonged heating, to produce more rapid in vitro digestion, resulted in a significantly higher incremental rise in large neutral amino acid levels at 60 min (p less than 0.02) and a tendency for a more rapid rise in total amino acid concentrations by comparison with conventionally cooked lentils with slower in vitro digestion rates. After more rapidly digested lentils, incremental levels of branched-chain amino acids were also higher at 60 min (67 +/- 9, p less than 0.001) despite a greater overall insulin response. Comparable incremental amino acid areas after both meals suggested that the total amount of amino acids absorbed was not influenced by processing. Greater blood glucose, insulin, and gastric inhibitory polypeptide responses were seen after the more processed meal with no significant differences in pancreatic glucagon, entroglucagon, or neurotensin levels. Processing a food to alter the rate of digestion may therefore be used to manipulate amino acid, glucose, and endocrine responses in cirrhosis.

Aged↗
PubMed1986

Randomized trial of oral adjuvant razoxane (ICRF 159) in resectable colorectal cancer: five-year follow-up.

Razoxane is one of the few agents which has shown activity in the treatment of advanced colorectal cancer. The drug has therefore been evaluated in a prospective randomized controlled trial as an adjuvant to surgery for resectable colorectal cancer. The results to median follow-up of 5 years are reported here. Accrual has ceased and a total of 272 patients entered the trial (133 control, 139 treatment). Treated patients received razoxane postoperatively on a continuous, long-term basis while control patients received identical clinical care but no adjuvant chemotherapy. Analysis of the results shows a significant prolongation of the time to recurrence for Dukes' C patients. All other groups including the overall analysis show no benefit although there is a consistent trend in favour of the treated patients except in Dukes' group 'D'. Razoxane is tolerated well by patients and causes minimal side-effects. However acute leukaemia occurred in three patients (2.45 per cent) after prolonged exposure to the drug and further evaluation should be in patients who are at high risk of developing recurrent cancer, in whom such a risk may be acceptable. It is concluded that razoxane is suitable for further evaluation in colorectal cancer and for incorporation into combination chemotherapy regimens.

Clinical Trials as Topic↗
PubMed1986

Regulation of the absorption of dietary carbohydrate in man by two new glycosidase inhibitors.

Two new reversible inhibitors of intestinal alpha-glycosidases (BAY m1099 & o1248) have been derived from deoxynojirimycin. Their inhibitory substrate specificity has been investigated in man using test meals of the dietary carbohydrates, sucrose, maltose, and starch. Both inhibitors abolished the postprandial glycaemic rise after sucrose and m1099 50 mg did after maltose and starch, whereas o1248 20 mg had no effect after maltose and only a small effect after starch. Breath hydrogen evolution, as an indirect measure of malabsorption, showed that the reduced glycaemic responses, particularly after sucrose, were associated with considerable substrate malabsorption. Dose response studies showed that lower doses of both inhibitors could reduce postprandial glycaemia significantly without causing malabsorption. Both inhibitors were tolerated well. These two new enzyme inhibitors have different substrate specificity in man and can, in appropriate dose, regulate postprandial glycaemia by selective inhibition of brush border enzymes without causing malabsorption. In addition to their therapeutic importance, they provide a valuable experimental model of specific intestinal enzyme deficiency states.

1-Deoxynojirimycin↗