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Biomedical subjects

M Brown

Publications and source records attributed to M Brown.

At least 613 records · Page 34Linked to original sources
PubMed1986

Heart rate and blood pressure effects of esmolol after ketamine induction and intubation.

Both ketamine and tracheal intubation are associated with increased heart rate (HR) and systolic blood pressure (SBP). Beta blockers prevent or attenuate this increase. Esmolol (E) is a new, intravenous, rapidly metabolized beta blocker. An open-label study was performed in 41 ASA Class II and III patients divided into groups 1-4: control, 100, 200, and 300 micrograms X kg-1 X min-1 (n = 10, 10, 11, and 10, respectively). E was infused over 10 min, the first one-fourth of which was a loading dose of 500 micrograms X kg-1 X min-1; at 4 min, ketamine was followed by succinylcholine, intubation, and enflurane-N2O-O2. HR, SBP, blood E, and plasma catecholamine levels were obtained during the 40 min of study. The control group had a baseline HR of 83 +/- 5 beats/min while esmolol groups 2-4 had an HR of 73 +/- 3, 72 +/- 3, and 68 +/- 4 beats/min, respectively (P less than 0.05). After ketamine, the control group HR increased to 93 +/- 6 beats/min and groups 2-4 remained at the baseline level, 73 +/- 3, 73 +/- 3 and 67 +/- 4 beats/min, respectively (P less than 0.05). Postintubation, the control increased further to 113 +/- 5 beats/min while groups 2-4 were significantly less, 91 +/- 5, 84 +/- 3, and 78 +/- 4 beats/min, respectively. The mean SBP in most E groups was less than the control within groups, but only in group 4 between groups was the SBP less at postintubation (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia↗
PubMed1986

Prolonged isoflurane anesthesia in status asthmaticus.

We report a case of status asthmaticus that was unresponsive to the usual agents. The use of an inhalational anesthetic agent allowed us to ventilate the patient with lower inspiratory pressures; however, lasting improvement did not occur until she mobilized large quantities of secretions. To our knowledge, this is the first clinical report on the use of isoflurane anesthesia to treat severe asthma. Despite prolonged administration, there were no significant side-effects. This case demonstrates both the benefits and limitations of such therapy.

Adult↗
PubMed1986

Phenytoin hypersensitivity hepatitis and mononucleosis syndrome.

We present a patient who developed a mononucleosis syndrome 6 weeks after starting phenytoin therapy for a seizure disorder. Improvement followed initial discontinuation of the phenytoin, but near-fatal hepatic necrosis resulted from intravenous phenytoin rechallenge. A serious reaction with a 18% overall mortality, phenytoin hepatitis may closely resemble infectious mononucleosis with fever, pharyngitis, lymphadenopathy, and atypical lymphocytosis. Continued administration of phenytoin or later rechallenge may increase the severity of the reaction.

Adult↗
PubMed1986

Extended leukocyte parameters for hematology analyzers.

Newly introduced, extended leukocyte parameters on laser-based hematology analyzers permit normal samples to be readily identified allowing these samples to be excluded from manual analysis. This enables more hematology laboratory resources to be focused on abnormal specimens. A new reagent that lyses erythrocytes while leaving the optical properties of the leukocytes unaltered is used. A special optical bench measures both narrow-angle forward light scatter (an indicator of cell size) and wide-angle light scatter (an indicator of cell granularity). The two scatter measurements are combined to produce a histogram in which lymphocytes, monocytes, and granulocytes are clearly delineated. A microprocessor detects the separation between histogram peaks, sets the proper thresholds, produces the three-part count, and indicates abnormal samples on the basis of histogram peak position, shape, and resolution. In a clinical study correlations between instrument counts and manual leukocyte differentials were very good. The potential for reducing the number of manual differentials of normal samples is significant.

Autoanalysis↗
PubMed1986

Evaluation of cell line 293 for virus isolation in routine viral diagnosis.

Cell line 293, a continuous line of transformed human embryonic kidney cells, has been recognized for its sensitivity in the isolation of adenoviruses, particularly the fastidious species 40 and 41, from stool specimens. To explore the possibility of using this cell line for the isolation of other viruses from clinical specimens, 293 cells were tested for their susceptibility to a variety of viruses including herpes simplex virus, parainfluenza viruses, respiratory syncytial virus, and the enteroviruses ECHO 11, coxsackie B5, and coxsackie B6. All of the viruses induced a cytopathic effect in 293 cells. Consequently, 293 cells were introduced into the diagnostic laboratory and used along with primary African green monkey kidney (AGMK) cell cultures for the inoculation of all respiratory and stool specimens. The study represents a retrospective analysis of the performance of 293 cells over a 22-month period. It was confirmed that 293 cells were more sensitive than AGMK cells for the isolation of adenoviruses from both respiratory and stool specimens. The 293 cells were also sensitive for the isolation of enteroviruses (untyped) but more so from stool specimens than from respiratory specimens. Parainfluenza virus and respiratory syncytial virus were only rarely isolated in 293 cells. Herpesvirus isolates were obtained with equal frequency in both 293 and AGMK cells. This retrospective analysis confirms the value of 293 cells for the isolation of adenoviruses and demonstrates that 293 cells are also useful for the isolation of certain enteroviruses from both respiratory and stool specimens.

Adenoviruses, Human↗
PubMed1986

A recombinant murine retrovirus for simian virus 40 large T cDNA transforms mouse fibroblasts to anchorage-independent growth.

A recombinant murine retrovirus containing the intact cDNA sequence for the simian virus 40 (SV40) large T antigen (T) was constructed by using the pZIPNeo SV(X)1 vector. Psi 2 packaging cells were then transfected, and G418-resistant clones were used to generate helper-free viral stocks. NIH 3T3 mouse fibroblasts infected by the recombinant T cDNA retrovirus were selected fro G418 resistance. Such cultures synthesized authentic SV40 T and were transformed to anchorage-independent growth at high efficiency. Therefore, this vector has allowed the study of the transformation properties of T under conditions of neutral drug selection and in the absence of SV40 small t antigen.

Animals↗
PubMed1986

Calcitonin gene-related peptide: a potent dilator of human epicardial coronary arteries.

To investigate the action of calcitonin gene-related peptide (CGRP) on human epicardial coronary arteries, six patients received intracoronary CGRP at doses of 50,100, and 200 ng/min. The effect of CGRP was measured angiographically with a computerized analysis system. A dose-dependent increase in coronary arterial diameter was observed. At the highest dose there were 34%, 7%, 38%, and 40% mean increases in the diameters of the circumflex, proximal, mid, and distal left anterior descending arteries, respectively. No further increase in diameter was found after a subsequent dose of 1 mg intracoronary isosorbide dinitrate. Prior infusion of CGRP did not prevent coronary arterial spasm induced by ergonovine in two patients with variant angina, but a subsequent bolus of CGRP partially relieved the spasm. We propose that CGRP has a role in the regulation of coronary vascular smooth muscle tone.

Angina Pectoris↗
PubMed1986

Surgical experience following intervertebral discolysis with collagenase.

Of 410 patients with refractory herniated lumbar disc disease treated with intradiscal collagenase, 82 (20%) did not respond to enzyme treatment and subsequently underwent surgery. Failure to improve in 6 to 8 weeks was the predominant cause for surgical intervention (53 patients). Increased pain (18 patients), progressing neurological deficit (10 patients), and disc-space infection (one patient) were the other indications for surgery. At surgery, extrusions and/or sequestrations were found in 46 patients, undigested protrusions in 16 patients, and other causes of treatment failure in 14 patients. Six patients had normal findings. There was no evidence of adverse enzyme activity on the surrounding structures. Surgical results showed an overall success rate of 87%, and did not appear to be compromised by the previous enzyme therapy.

Adult↗
PubMed1986

Peritoneal fluid volume, estrogen, progesterone, prostaglandin, and epidermal growth factor concentrations in patients with and without endometriosis.

Elevated prostaglandin (PG) levels in peritoneal fluid have been implicated as playing a role in infertility associated with endometriosis. This study was designed to measure peritoneal fluid levels of PG and other hormones that may influence PG release. Specific hormones measured included PGF2 alpha, PGE2, TxB2, 6-keto-PGF1 alpha, estrogen, progesterone, and epidermal growth factor. Peritoneal fluid volume and levels of estrogen, progesterone, and epidermal growth factor were significantly (P less than .05) increased during the secretory, as opposed to the proliferative, phase in both groups of patients, but no significant differences in these parameters were found between patients with and without endometriosis during either the proliferative or secretory phases. Although PG levels did not vary during the menstrual cycle in either group of patients, all four prostanoids were present in significantly (P less than .05) higher concentrations in patients with endometriosis as compared with patients without endometriosis. Furthermore, increased PG levels in patients with endometriosis appear to be due primarily to an increase in PG levels during the secretory phase of the cycle.

6-Ketoprostaglandin F1 alpha↗
PubMed1986

Oestrogen receptor concentration and macrophage infiltration in human breast cancer.

Oestrogen receptor concentration and percentage macrophage content were estimated in 40 human primary breast cancers. Macrophages were identified by Fc (IgG) receptor expression and by the presence of a macrophage-associated antigen. A significant inverse correlation between receptor concentration and macrophage content was found, and this was strengthened by correcting receptor level for tumour cellularity.

Breast Neoplasms↗
PubMed1986

Control of hypertension following carotid endarterectomy.

The role of carotid endarterectomy in the treatment of extracranial carotid artery disease has been well established. Postoperative hypertension is a significant prognostic factor and is associated with an increased incidence of both transient and permanent neurologic deficits. We studied 110 patients undergoing unilateral carotid endarterectomy to review the efficacy of the drug combination of hydralazine and propranolol to treat postoperative hypertension. All patients receiving hydralazine and propranolol had their blood pressure controlled postoperatively, and no patients developed hypotension, myocardial infarction, or postoperative neurologic deficits. There were no mortalities in the study group. We conclude that propranolol-hydralazine therapy is a safe and effective means to control hypertension associated with carotid endarterectomy.

Aged↗
PubMed1985

Both [1-14C]glucose and 2-[1-14C]deoxyglucose produce selective iso-frequency labelling in the inferior colliculus of the cat with short stimulation periods.

Both [1-14C]glucose and 2-[1-14C]deoxyglucose (2-DG) revealed selective autoradiographic labelling to tones in the inferior colliculus of the cat with short stimulation periods (5-15 min). With longer periods of stimulation (45 min), the selectivity disappeared with glucose but remained with 2-DG. At all stimulation intervals, 2-DG labelling was always more selective than that obtained with glucose. However, the selectivity seen with glucose was good enough to indicate that isotopes of glucose with short half-lives could still be employed to study human functional activity with the positron emission tomography technique, provided that short stimulation periods were used.

Animals↗