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Biomedical subjects

M Reynolds

Publications and source records attributed to M Reynolds.

At least 109 records · Page 6Linked to original sources
PubMed1986

Sequential studies of bone marrow haemopoietic progenitors (CFU-GEM, BFU-E, CFU-E, CFU-GM) following busulfan treatment in Balb/c mice.

The effect of multiple sublethal doses of busulfan on the haemopoietic system of the Balb/c mouse was examined. FBC's bone marrow histology and bone marrow progenitor cell assays (CFU-E, BFU-E, CFU-GM and CFU-GEM) were performed. No effect was seen on FBC's or on marrow histology. However there was a significant depletion noted in the number of haemopoietic progenitor cells as measured by in vitro culture.

Aging↗
PubMed1985

Histochemical assessment of cytochrome oxidase activity for monitoring ischemic muscle injury.

Electromyographic detection of increased neuromuscular conduction latency that follows electrostimulation of spinal nerves has been used widely as a clinical tool for detection of ischemic muscle injury. We hypothesized that a biochemical marker for stagnant hypoxia provides more direct evidence for evaluating severity and monitoring resolution of ischemic muscle injury than the EMG. To detect intracellular changes in oxygen use during experimental ischemia, ultrathin sections of rat gastrocnemius muscle were treated with reducing agent, 3,3'-diaminobenzidine (DAB), a histochemical marker for intramitochondrial cytochrome oxidase activity. The observed decrease in mitochondrial uptake of DAB suggested that a decrease in cytochrome oxidase activity was associated with experimental ischemia. Neuromuscular conduction latency in rat gastrocnemius muscle was also quantitated after electrostimulation of the sciatic nerve. Ligation of the femoral artery produced ischemic tissue injury, during which recordings of the EMG showed that conduction latency increased [from a mean +/- SEM control value of 3.09 +/- 0.13 to 3.92 +/- 0.22 ms (N = 11, P less than 0.001).] The changes in both histochemically detectable cytochrome oxidase activity and neuromuscular conduction latency were reversed by reperfusion. Response of the rat tissue to arterial occlusion was thereby shown to be a physiologic model for skeletal muscle response to ischemia. In addition, histochemical detection of cytochrome oxidase activity was shown to be a sensitive intracellular marker for decreased oxygen use during ischemic muscle injury.

Animals↗
PubMed1985

The valved conduit prevents ascending cholangitis: a follow-up.

Reflux of bacteria-laden intestinal contents into the biliary tree can be prevented by an intussuscepted valve in an isolated segment of jejunum interposed between the porta hepatis and the duodenum. This method of bile duct reconstruction was adopted in 1979 and since then has been used in 17 children with biliary atresia and 9 with choledochal duct cysts. Those with choledochal duct cysts are well. Follow-up HIDA scans demonstrate normal bile flow, and ultrasound examinations have not revealed dilated bile ducts. Bile flow was established in 13 infants with biliary atresia and was persistent in 8. Two expired because of unrelated problems between 2 to 6 months postoperatively. One of these children developed cholangitis, but at autopsy the nipple valve was incompetent. Six children currently have normal serum bilirubin levels and are clinically well. The average postoperative stay for these patients was 7.5 days. Three were rehospitalized for brief periods for suspected cholangitis which was not proven. Bile flow was never established in 4 babies and was present only briefly in 5. Five of these children died of progressive liver failure and one from unrelated causes. Two have had liver transplants, and a third is awaiting transplantation.

Bile↗
PubMed1985

Human marrow stromal cells in short-term semi-solid bone marrow culture in aplastic anaemia.

A short-term methylcellulose technique was used to study the proliferation of marrow-derived stromal, erythroid and myeloid colonies from normal controls and from patients with aplastic anaemia. There was a significant reduction in all colony types in patients with aplastic anaemia when compared with normal controls. In 4 patients who achieved remission following treatment with ATG + oxymetholone or with oxymetholone alone there was a return to normal range of stromal colonies and also of CFU-E. There was no change in the numbers of BFU-E's and only a slight increase in the numbers of CFU-C's.

Adolescent↗
PubMed1985

Treatment of severe aplastic anaemia with anti-thymocyte globulin.

Ten patients (9 adults, 1 child) with severe aplastic anaemia (SAA) were treated with anti-thymocyte globulin (ATG). All patients developed serum sickness. No long-term adverse sequelae attributable to ATG were noted. Fifty percent of patients are alive at 1 year post-ATG. One patient received an allogeneic bone marrow transplant because of failure to respond to ATG. One long-term survivor is severely thrombocytopenic and requires support, and one patient has mild thrombocytopenia requiring oxymetholone therapy.

Adolescent↗
PubMed1985

The effect of vitamin E on mammary dysplasia: a double-blind study.

Alpha-tocopherol (vitamin E) has been used to treat patients with benign breast disease. To evaluate the efficacy of this treatment, a randomized, double-blind placebo-controlled study was performed on 128 women with confirmed mammary dysplasia. Patients were treated with placebo or 150, 300, or 600 IU of d, 1 alpha-tocopherol per day for two months; breast examinations, sonography, and thermography were performed in the midluteal phase of the menstrual cycle before and after treatment. No significant objective effects to treatment were noted in any of the parameters monitored. In addition, serum concentrations of estradiol, progesterone, dehydroepiandrosterone sulfate, and testosterone were measured before and after treatment. There were no significant effects on concentrations of these hormones. From this study, d, 1 alpha-tocopherol does not seem to be beneficial in the treatment of patients with mammary dysplasia.

Clinical Trials as Topic↗
PubMed1984

Relationship between intracellular oxygenation and neuromuscular conduction during hypoxic hypoxia.

Previous studies have shown that high-altitude hypoxic hypoxia is associated with reduced ventilatory capacity that may be related to skeletal muscle weakness. In the present investigation, ascent to high altitude (4,000 m) was simulated experimentally by exposure of male rats (Sprague-Dawley, 250-350 g), anesthetized with thiopental sodium (25 mg/kg, i.p.), to a breathing gas mixture of 12% oxygen diluted in 88% nitrogen (FiO2 = 0.12). Determinations of oxygen saturation on microsamples (250 ul) of arterial and central venous blood were made spectrophotometrically. Neuromuscular conduction latency was measured following electrostimulation of the sciatic nerve (1-5 V, 0.5 msec duration, 1-40 Hz) and recording of the electromyogram from the gastrocnemius muscle. Experimental hypoxia (FiO2 = 0.12) produced a highly significant increase in conduction latency from a control value (mean +/- SEM) of 3.06 +/- 0.16 msec to 4.02 +/- 0.31 msec (n = 10, P less than 0.001). Conduction latency increased with decreasing arterial oxygen saturation from a control value of 92.9% +/- 0.18% to 83.2% +/- 0.76% (P less than 0.001) in the absence of statistically significant changes in central venous oxygen saturation, central venous pressure, arterial and central venous pH, and heart rate. A significant decrement in the mean arterial blood pressure from a control value of 85 +/- 1.5 mm Hg to 69 +/- 1.5 mm Hg suggests that local ischemia may be a component of this model. These responses were accompanied by marked reduction in uptake of 3,3'-diaminobenzidine (DAB) by gastrocnemius muscle mitochondria, suggesting decreased intracellular activity of cytochrome oxidase. It was concluded that exposure of rodents to hypoxic gas mixtures may provide a suitable model for studying the mechanism of skeletal muscle weakness associated with ascent to high altitude and of other conditions wherein the supply of oxygen to tissues is limited.

3,3'-Diaminobenzidine↗
PubMed1984

The effects of a series of capsaicin analogues on nociception and body temperature in the rat.

A series of capsaicin analogues have been synthesized in an attempt to try to separate the antinociceptive properties of capsaicin from its hypothermic effects. In capsaicin analogues with an unbranched alkyl side-chain of varying length, maximum antinociceptive and hypothermic activity was achieved with a chain length of 8-9 C atoms. Decreasing the chain length decreased both parameters equally. Substitution in the aromatic ring abolished activity. Several compounds related to homovanilloyl dodecylamide, an analogue of capsaicin in which the acylamide linkage is reversed, produced some antinociceptive activity without concomitant hypothermia, but the maximum antinociceptive effect achieved was very small. In the present series of capsaicin analogues good antinociception without hypothermia was not found.

Animals↗
PubMed1984

The "critical" neonate with diaphragmatic hernia: a 21-year perspective.

We have seen a modest improvement in the survival of a homogeneous group of critically ill newborns with congenital diaphragmatic hernia since 1979. Twenty-seven "critical" infants have been treated who developed respiratory distress shortly after birth, required urgent resuscitation, and could not be stabilized before operation. Two died with other anomalies that appeared incompatible with prolonged survival. Ten of the 27 lived. This survival contrasts with that of only two of 17 similarly affected babies treated from 1962 to 1978. In addition, there has been no operative mortality outside of this "critical" group since 1979; whereas six noncritical babies died between 1967 to 1978. Our current therapeutic plan includes the early establishment of a respiratory alkalosis and vasodilator therapy before or during transport. Postoperatively we have attempted to maintain the baby's arterial pH greater than 7.5, Pco2 less than 25 to 30 and the PO2 approximately 150 torr. The most effective ventilatory parameters have been a rate of 130, PEEP of 5 and an inspiratory:expiratory ratio of 1:1. Peak airway pressures are kept as low as possible. Pharmacologic and ventilator therapy are weaned slowly, and intensive support has been required for at least 48 hours in each baby. Retained secretions and atelectasis of the hypoplastic lung persisted for two to several weeks postoperatively. Two babies that are one year or older still appear to have severely hypoplastic lungs on chest x-ray. M-mode echocardiography has been used to measure ventricular ejection periods. The right ventricular systolic time interval correlates with the degree of pulmonary hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)

Critical Care↗
PubMed1984

The effect of alpha-tocopherol on premenstrual symptomatology: a double-blind study. II. Endocrine correlates.

In a randomized, double-blind, dose-response study, alpha-tocopherol significantly ameliorated symptoms in three of the four classes of the premenstrual syndrome (PMS). Alpha-tocopherol treatment had no significant effect on serum concentrations of testosterone, dehydroepiandrosterone sulfate (DHEA-S), estradiol, and progesterone. However, independent of treatment, a significant correlation emerged between temporal changes in one PMS category and changes in DHEA-S concentrations. These results suggest that improvement in PMS severity is not mediated through direct effects of alpha-tocopherol on serum steroids. Androgens, however, may play a role in some PMS symptomatology.

Clinical Trials as Topic↗
PubMed1984

Reliability of contact-thermogram reading services.

Contact thermography has been advocated by some as a rapid, noninvasive diagnostic modality in evaluating patients at risk for breast cancer. In order to study the value of different criteria for interpreting thermograms, two sets of contact thermograms from 34 patients with benign breast disease were submitted to two different reading services. The results suggest that interrater agreement is enhanced when thermograms are classified as "normal" and "abnormal" rather than as class I-V.

Body Temperature↗
PubMed1983

Serum unconjugated estriol concentrations before and after the oxytocin challenge test: an index of fetal well-being.

Serum unconjugated estriol concentrations before and after the oxytocin challenge test (stress test) were measured in 54 high-risk, obstetric patients. Six of the stress test results were positive, and eight were equivocal. Eleven patients demonstrated decrements in estriol of greater than or equal to 25% after stress tests, and the infants of six of these patients demonstrated perinatal morbidity. Three patients exhibited positive stress test results but had estriol concentrations which were unaltered by the stress test; all were delivered vaginally of healthy infants shortly after the stress test. The coefficient of correlation between the stress test and perinatal outcome was 0.58 (P less than 0.001). When the estriol and stress test results were combined to predict outcome, a multiple correlation coefficient of 0.71 was obtained (P less than 0.001). This increment represents a significant (P less than 0.001) and substantial (18%) improvement in the prediction of perinatal outcome. These findings indicate that the measurement of changes in estriol with the stress test significantly improves one's ability to define the fetus at risk.

Estriol↗
PubMed1983

Ventriculoperitoneal shunt infection masquerading as an acute surgical abdomen.

Shunting of cerebrospinal fluid to the peritoneal cavity has brightened the outlook for children with hydrocephalus. Nine hundred sixty-nine primary ventriculoperitoneal shunts were inserted for hydrocephalus between 1970 and 1981. During this same period, 2205 shunt revisions were performed in 847 children, some of whose primary shunt had been inserted prior to 1970 or at other institutions. Nineteen patients with a ventriculoperitoneal shunt infection persented with abdominal pain, fever, and abdominal tenderness; each had acute peritonitis. Three underwent laparotomy with the preoperative diagnosis of appendicitis; however, only infected peritoneal fluid and nonobstructing adhesions were found. A fourth child underwent an unnecessary intestinal resection at another hospital and required prolonged nutritional support and treatment of severe postoperative complications. Fifteen children who presented with an "acute surgical abdomen" were managed with intravenous fluids, gastric decompression, antibiotics, and removal of the intraperitoneal shunt. External ventricular drainage was employed until the cerebrospinal fluid was sterile. The shunt was then internalized in the peritoneal cavity. The abdominal signs and symptoms improved after removing the peritoneal tubing in all children. This plan of therapy has eliminated unnecessary laparotomy in those who may require repeated procedures for control of hydrocephalus.

Abdomen, Acute↗