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Biomedical subjects

B Young

Publications and source records attributed to B Young.

At least 199 records · Page 11Linked to original sources

Nephrotoxicity of parenterally administered cyclosporine after orthotopic liver transplantation.

The frequency of nephrotoxicity in the absence of identifiable prerenal or postrenal causes within five days of operation in 27 liver transplant recipients was found to be 71% in those treated with i.v. cyclosporine alone, 37.5% with i.m. cyclosporine alone, and 16.7% with prednisolone and azathioprine. Renal failure following i.v. cyclosporine was characterized by an immediate fall in urine output and creatinine clearance with well-preserved tubular function--findings consistent with a reduction in renal blood flow or glomerular filtration rate, or both.

Acute Kidney Injury↗

Failure of prophylactically administered phenytoin to prevent post-traumatic seizures in children.

We report the results of a randomized, double-blind, placebo-controlled study to determine whether phenytoin administered soon after a head injury lessens the incidence of late post-traumatic epilepsy in children. 41 patients were randomized into either a phenytoin or placebo group and followed for 18 months. The patients were administered phenytoin or placebo intravenously or intramuscularly within 24 h of hospital admission. The patients were parenterally administered phenytoin or placebo until oral doses could be tolerated. There was no significant difference in the percentage of children having seizures in the treated and placebo groups (p = 0.25).

Brain Injuries↗

Cutaneous reactions in head-injured patients receiving phenytoin for seizure prophylaxis.

Two types of adverse effects are caused by phenytoin, reversible dose-dependent central nervous system effects and non-dose dependent hypersensitivity effects. The most common presenting symptom of the hypersensitivity reaction is the development of a morbilliform rash. During a 45-month period, 151 head-injured patients received phenytoin for seizure prophylaxis using an 11-mg/kg i.v. and a 13-mg/kg i.m. parenteral loading dose followed by an i.m. or p.o. maintenance dose for therapeutic blood concentrations (10 to 20 micrograms/ml). The patients were followed for 18 months. The incidence of skin reaction to phenytoin was 19.4%, or 24 of 124 patients. Cutaneous reactions occurred from Day 5 through Day 91 of phenytoin therapy. Two patients had more serious reactions after the cutaneous reaction. One patient developed exfoliative dermatitis, and 1 had a pseudolymphoma type syndrome. Both recovered. Patients with cutaneous reactions had higher absolute eosinophil counts (P = 0.01). Other laboratory parameters of the white blood count and the total lymphocyte counts did not differ significantly. Patients receiving dexamethasone had a higher incidence of rash, but this did not reach statistical significance. Because recent data have not documented a seizure-prophylactic effect of phenytoin, only a head-injured patient who has experienced a first posttraumatic seizure should receive the drug.

Adolescent↗

Failure of prophylactically administered phenytoin to prevent early posttraumatic seizures.

A randomized double-blind placebo-controlled study was carried out to determine whether phenytoin administered soon after injury lessens the incidence of epilepsy in the 1st week after severe head trauma. In this study, 244 patients were randomized into either a phenytoin or placebo group. The patients in the phenytoin group were administered phenytoin intravenously or intramuscularly within 24 hours of hospital admission. Patients in the placebo group received intravenous or intramuscular diluent. The patients were switched from parenterally administered phenytoin or placebo as soon as oral doses could be tolerated. Over 78% of the phenytoin patients had plasma concentrations of at least 10 micrograms/ml at 1, 3, and 7 days after injury. There was no significant difference in the percentage of patients having early seizures in the treated and placebo groups (p = 0.99). There was no significant difference in the interval from injury to first seizure between the treated and placebo groups (p = 0.41). The early administration of phenytoin did not lessen the occurrence of seizures in the 1st week after head injury. Since the effectiveness of seizure prophylaxis has not been established, the authors suggest that anticonvulsant drugs be administered only after an early seizure has occurred.

Brain Injuries↗

Failure of prophylactically administered phenytoin to prevent late posttraumatic seizures.

This randomized double-blind placebo-controlled study was undertaken in a series of 179 patients to determine whether phenytoin administered soon after head injury lessens the incidence of late posttraumatic epilepsy. When delayed hypersensitivity to phenytoin developed, the patient was switched to phenobarbital. The patients were followed for 18 months to detect the occurrence of seizures and to serially measure plasma phenytoin concentrations. There was no significant difference in the percentage of patients having late seizures in the treated and placebo groups (p = 0.75). The time between injury and seizures did not significantly differ between the two groups. The results provide no support for the continued use of phenytoin in the low therapeutic range for prophylaxis against late posttraumatic seizures. It cannot be concluded that higher phenytoin plasma concentrations and higher compliance rates than obtained in this study would not have significantly decreased the occurrence of late posttraumatic epilepsy. The finding that no patient with a phenytoin plasma concentration of 12 microgram/ml or higher had a seizure raises the question of whether phenytoin in blood concentrations in higher therapeutic ranges might lessen the occurrence of posttraumatic epilepsy, and should be studied further. Posttraumatic epilepsy is a major public health problem deserving a large cooperative trial to determine if phenytoin at higher blood levels than obtained in this study, or other currently available or newly developed drugs, can prevent the occurrence of posttraumatic epilepsy.

Adolescent↗

The favorable effect of early parenteral feeding on survival in head-injured patients.

This prospective randomized controlled clinical trial compares the effects of early parenteral nutrition and traditional delayed enteral nutrition upon the outcome of head-injured patients. Thirty-eight head-injured patients were randomly assigned to receive total parenteral nutrition (TPN) or standard enteral nutrition (SEN). Clinical and nutritional data were collected on all patients until death or for 18 days of hospitalization. Survival and functional recovery were monitored in survivors for 1 year. Of the 38 patients, 18 were randomized to the SEN group and 20 to the TPN group. Demographically, the two groups of patients were similar on admission. There was no significant difference in the severity of head injury between the two groups as measured by the Glasgow Coma Scale (p = 0.52). The outcome for the two groups was quite different, with eight of the 18 SEN patients dying within 18 days of injury, whereas no patient in the TPN group died within this period (p less than 0.0001). The basis for the improved survival in the TPN patients appears to be improved nutrition. The TPN patients had a more positive nitrogen balance (p less than 0.06), and a higher serum albumin level and total lymphocyte count. More adequate nutritional status may have improved the patients' immunocompetence, resulting in decreased susceptibility to sepsis. The data from this study strongly support the favorable effect of early TPN on survival from head injury.

Adult↗

The role of radiation treatment in craniopharyngioma.

The long natural course of craniopharyngioma and short-term follow-up period in many reports make comparison of various treatment results difficult. Some patients may enjoy virtually symptom-free lives despite known recurrence. Some patients with recurrence may have a good response to retreatment. Such unpredictable behavior and treatment responses have led to considerable disparity in clinical reports concerning the best treatment method. Treatments using surgery alone and/or low dose postoperative radiation treatment could prolong survival time, but may not prevent recurrence leading to ultimate failure. High dose postoperative radiotherapy following radical surgery should be an ideal approach in dealing with this tumor.

Adolescent↗

Double-blind clinical trial of acyclovir and adenine arabinoside in herpetic corneal ulceration.

The results of a double-blind clinical trials of acyclovir and adenosine arabinoside (ara-A) in 93 patients with herpetic keratitis demonstrated a significantly faster healing rate for acyclovir (p less than 0.01). Ulcers in 45 (94 percent) of acyclovir-treated patients and 37 (82 percent) of ara-A-treated patients healed within 14 days. No serious side effects were observed.

Acyclovir↗

Increased hyaluronic acid is associated with dermal delayed-type hypersensitivity.

Rabbits sensitized subcutaneously with heat-killed bacilli Calmette-Guerin (BCG) and challenged intradermally with heat-killed BCG or purified protein derivative (PPD) demonstrated classical dermal delayed-type hypersensitivity which peaked two days postchallenge. Animals challenged with BCG developed dermal granulomas as measured by induration and gross observation. Challenge with either PPD or BCG resulted in increased levels of dermal hyaluronic acid (HA) by two days postchallenge. Dermal HA returned to normal levels by seven days postchallenge regardless of the challenge antigen. These results indicated that increased HA is associated with dermal delayed-type sensitivity, but increased HA is not associated with dermal granulomatous hypersensitivity. These results are in contrast to previously reported work which indicates that increased HA is associated with both pulmonary delayed hypersensitivity and pulmonary granulomatous hypersensitivity.

Animals↗

Limited usefulness of aortic arch angiography in the evaluation of carotid occlusive disease.

The role of aortic arch angiography in the evaluation of cerebral ischemic disease is not well defined. In an attempt to develop guidelines for its optimal use, a prospective study of 100 patients with carotid distribution ischemic events was undertaken. Each patient underwent bilateral selective carotid angiography followed by arch aortography. In only two of the cases did the arch examination affect patient management. In the other individuals, the arch study either added no clinically useful information (69), or demonstrated abnormalities that did not affect patient care (29). The findings of this study support the use of arch aortography only in those patients who have surgical lesions demonstrated by the selective carotid examinations.

Adolescent↗

Concanavalin A stimulation of mouse lymphocytes at low concentration. I. The effect of peritoneal exudate cells.

The results presented here show that concanavalin A (Con A) stimulated mouse spleen lymphocytes cultured at 1/10th optimal concentration incorporated less [3H]-TdR than those cultured at the optimal concentration. It was possible to increase the response of 1/10th optimal concentration lymphocytes by supplementing the cultures with macrophage-rich peritoneal exudate cell (PEC) preparations. This effect was dependent on the PEC concentration. [3H]-TdR incorporation by lymphocytes at optimal concentration was inhibited by the addition of PEC to the cultures. Thymocyte cultures at 1/10th optimal concentration also showed increased [3H]-TdR incorporation when supplemented with PEC but there was no inhibition effect at optimal concentration. PEC which had been pretreated with fresh mitomycin C to prevent cell division were as effective as controls at promoting the stimulation of 1/10th optimal concentration lymphocytes. PEC which had been killed were much less effective than controls.

Animals↗

Concanavalin A stimulation of mouse lymphocytes at low concentration. II. The effect of conditioned medium from peritoneal exudate cells and from lymphocyte cultures.

The first paper in this series reported that it was possible to reconstitute the response of low concentrations of mouse spleen lymphocytes to concanavalin A (Con A) by adding smaller numbers of peritoneal exudate cells (PEC) to the cultures. In this paper it is shown that the role of the PEC in this system can be partially replaced by conditioned medium (CM) prepared from PEC cultures or completely replaced by CM taken from lymphocytes cultured at optimal concentration. These CM were inactive unless fresh Con A was added to the assay cultures. Activity was present in Cm which was incubated with lymphocytes or PEC for the shortest possible time but maximal activity was found after 24 hr of incubation. Activity was also found in Cm prepared in the absence of Con A. Only in the case of lymphocytes cultured at optimal concentration for 24 hr was there substantially more activity in the CM thus prepared if Con A was present. PEC preparations depleted of T lymphocytes produced as much activity in Cm as the untreated control. CM produced by PEC was less sensitive to heat treatment or to freezing and thawing than that produced by lymphocyte cultures.

Animals↗

Anterior decompression and fusion for thoracolumbar fractures with neurological deficits.

Anterior spinal decompression and fusion was used as the primary treatment for thoracolumbar fractures in eleven patients with neurological deficits. Each patient achieved stability by interbody fusion. Significant progressive kyphosis did not occur. No patients with a complete neurological deficit was improved by operation, but all eight patients with partial neurological deficits showed improved lower extremity motor function postoperatively. Bladder function improved in five of the eight patients with incomplete lesions. The authors recommend this operative approach for spinal stabilization and removal of anteriorly located bone or disc fragments causing progressing and stable partial neurological deficits, and find second-stage posterior fixation with Harrington rods unnecessary in the great majority of cases.

Female↗

Theophylline toxicity after the use of aminophylline in the treatment of cerebral vasospasm.

We are reporting a case of theophylline toxicity after the initiation of i.v. aminophylline and isoproterenol in the treatment of cerebral vasospasm. The dose of aminophylline (125 mg/hour) previously recommended results in a toxic serum theophylline concentration in a majority of patients if the infusion is continued for more than 24 to 48 hours. The rapid achievement of an optimal serum level is obtained with a standard loading dose of 8.0 mg/kg. The initial infusion rate should be based on calculated pharmacokinetic data. Maintenance dosing adjustments are then based on serum determinations and the presence of toxic effects.

Aminophylline↗