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Biomedical subjects

L J Morgan

Publications and source records attributed to L J Morgan.

15 recordsLinked to original sources
PubMed1997

Insulin activation of phosphatidylinositol 3-kinase in human skeletal muscle in vivo.

The purpose of this investigation was to determine whether insulin-stimulated phosphatidylinositol 3-kinase (PI3-kinase) activity is detectable in needle biopsies of human skeletal muscle. Sixteen healthy nonobese males matched for age, percent fat, fasting insulin, and fasting glucose participated in one of two experimental protocols. During an intravenous glucose tolerance test (IVGTT) protocol, insulin-stimulated PI3-kinase activity was determined from percutaneous needle biopsies at 2, 5, and 15 min post-insulin administration (0.025 U/kg). In the second group, a 2-h, 100 mU . m-2 . min-1 euglycemic hyperinsulinemic clamp was performed, and biopsies were obtained at 15, 60, and 120 min after insulin infusion was begun. Insulin stimulated PI3-kinase activity by 1.6 +/- 0.2-, 2. 2 +/- 0.3-, and 2.2 +/- 0.4-fold at 2, 5, and 15 min, respectively, during the IVGTT. During the clamp protocol, PI3-kinase was elevated by 5.3 +/- 1.3-, 8.0 +/- 2.6-, and 2.7 +/- 1.4-fold above basal at 15, 60, and 120 min, respectively. Insulin-stimulated PI3-kinase activity at 15 min post-insulin administration was significantly greater during the clamp protocol vs. the IVGTT (P < 0.05). These observations suggest that insulin-stimulated PI3-kinase activity is detectable in needle biopsies of human skeletal muscle, and furthermore, that the euglycemic, hyperinsulinemic clamp protocol may be a useful tool to assess insulin signaling in vivo.

Adult↗
PubMed1994

Peritoneal drainage as primary management of perforated NEC in the very low birth weight infant.

Advances in perinatal and neonatal care in the past decade have produced a change in the population of infants with perforated necrotizing enterocolitis (NEC) treated at our institution: the majority are now of very low birth weight (VLBW, < 1,000 g). Peritoneal drainage has been reported as an initial resuscitative procedure for unstable infants who have complicated NEC. Initial success with peritoneal drainage prompted us to adopt an aggressive approach to its use in this patient population. Since 1987, peritoneal drainage has been the primary treatment for most infants weighing less than 1,500 g who have perforation, and for unstable infants weighing more than 1,500 g. Perforation was documented by pneumoperitoneum or aspiration of meconium by paracentesis. Intestinal resection was performed in most infants weighing more than 1,500 g and in those for whom drainage was ineffective. Twenty-nine infants with low or VLBW (mean gestational age, 27 weeks; mean birth weight, 994 g) were treated with one or two drains in the right lower quadrant. Broad spectrum antibiotics were continued until all drains were removed, usually within 10 to 14 days. Nasogastric suction was continued until patency of the gastrointestinal (GI) tract was confirmed by a nonionic upper GI series. Six (21%) infants died, although one of the deaths occurred 5 months after drainage; the patient had chronic lung disease and an intact GI tract. Seventeen of the 23 (74%) survivors required no further operative procedure, and 6 (26%) required laparotomy and resection because drainage had been ineffective. Peritoneal drainage provided definitive treatment in 18 of 29 (62%) infants in this series.(ABSTRACT TRUNCATED AT 250 WORDS)

Drainage↗
PubMed1994

Caffeine-induced hypercalciuria and renal prostaglandins: effect of aspirin and n-3 polyunsaturated fatty acids.

Effects of aspirin and fish-oil ingestion on caffeine-induced hypercalciuria and renal prostaglandins (PG) were investigated in 12 healthy women. The 11-wk study consisted of 7-d baseline, 5-d aspirin (1000 mg/d), 11-d washout, and two 24-d fish-oil periods (FO-1 and FO-2, respectively, providing 1.5 vs 3.0 g n-3 fatty acids/d) separated by a 4-d washout period. Caffeine-load (CL) tests providing 5 mg caffeine/kg body wt were administered after baseline and each experimental period. Timed urine samples were collected precaffeine (basal) and at 1, 2, and 3 h post-caffeine. PGE2 excretion decreased during tests after aspirin and FO-2. There were significant increases in PGF2 alpha from baseline during each CL test. Hypercalciuria was observed during each CL test and the magnitude of this response was not altered by the experimental treatments. The finding that concentrations of post-caffeine urinary PGF2 alpha paralleled concentrations of urinary calcium supports the possibility that this prostaglandin plays a role in caffeine-induced hypercalciuria.

Administration, Oral↗
PubMed1994

Frequency of (n-3) polyunsaturated fatty acid consumption induces alterations in tissue lipid composition and eicosanoid synthesis in CD-1 mice.

This study assessed the effect of frequency of consumption of a diet containing 10 g fat/100 g, with a (n-3):(n-6) polyunsaturated fatty acid (PUFA) ratio of 0.5, on tissue fatty acid composition and eicosanoid synthesis in CD-1 mice. With greater (n-3) PUFA consumption frequency, hepatic and peritoneal cell (n-3) PUFA levels changed to 14.4 +/- 1.3 and 12.4 +/- 0.9 mol/100 mol, respectively, from 2.4 +/- 0.3 and 1.9 +/- 0.3 mol/100 mol in control animals consuming a diet without (n-3) PUFA. Hepatic and peritoneal cell (n-6) PUFA levels were reduced to 6.4 +/- 0.5 and 7.6 +/- 0.5 mol/100 mol, respectively, with daily (n-3) PUFA consumption, compared with 23.6 +/- 0.7 and 17.9 +/- 0.7 mol/100 mol in control animals. Prostaglandin E, 6-keto-prostaglandin F1 alpha, and 4-series sulfidopeptide leukotriene biosyntheses reflected frequency of (n-3) PUFA consumption, with daily (n-3) PUFA consumption reducing prostaglandin E, consumption of (n-3) PUFA every other day reducing 6-keto-prostaglandin F1 alpha, and (n-3) PUFA consumption every 3 d reducing leukotriene C4 and leukotriene E4. Leukotriene C5 and leukotriene E5 changed from undetectable in animals consuming the control diet to > 40% of total leukotriene production in animals consuming (n-3) PUFA daily. Daily to biweekly consumption of fish or fish oil [1.26-0.63 g/wk of (n-3) PUFA, 6-3% of energy] may be a means for changing eicosanoid production. Consumption of (n-3) PUFA less often than twice a week may not change eicosanoid synthesis.

Administration, Oral↗
PubMed1990

Glycated haemoglobin and fructosamine in non-diabetic subjects with chronic renal failure.

Measurements of glycated haemoglobin by electroendosmotic and chromatographic methods, fructosamine, and fructosamine:albumin ratio were made in 91 non-diabetic subjects with chronic renal failure managed conservatively (n = 25), by continuous ambulatory peritoneal dialysis (n = 22), by haemodialysis (n = 22), or by renal transplantation (n = 22). Results were compared with those in a control group of 43 non-diabetic subjects with normal renal function. Mean glycated haemoglobin measured by electroendosmosis was significantly greater in all groups with chronic renal failure except the transplant group. Mean glycated haemoglobin measured by affinity chromatography was not significantly different from controls in any of the groups with chronic renal failure. No difference in mean fructosamine concentration was detected in the transplant or conservatively managed groups compared to controls, but values were significantly lower in the CAPD group, and greater in the haemodialysis group predialysis. Post-haemodialysis samples showed a significant reduction in mean fructosamine concentration when compared with prehaemodialysis samples. Fructosamine:albumin ratios were elevated in all groups of patients with renal failure, with the exception of the transplant group. Of the four indices of glycaemic control considered in this study, only glycated haemoglobin measured by affinity chromatography appears to be unaffected by chronic renal failure.

Adolescent↗
PubMed1987

External ventricular drainage for initial treatment of neonatal posthemorrhagic hydrocephalus: surgical and neurodevelopmental outcome.

Thirty-seven infants were treated for posthemorrhagic hydrocephalus (PHH) with external ventricular drainage (EVD) in 1977-1985. The mean age at EVD placement was 13 days; the mean duration of drainage was 21 days, and an average of 1.8 drains was used per patient. Complications were apnea (10%), hemorrhage (8%) and ventriculitis (6%). Ten infants died from pulmonary disease unrelated to the surgery. Thirty-two percent of the survivors did not require a permanent shunt. Neurodevelopmental outcome was evaluated at a mean age of 38 months. Eighteen of the twenty-seven survivors (67%) had normal cognitive function, 3 had borderline and 6 (22%) had moderate to profound mental retardation. Nine of the children (33%) had a normal neuromuscular exam. One child had mild, 11 had moderate and 6 had severe cerebral palsy. Four children had serious visual impairment. The worst outcomes were in the children with parenchymal or large intraventricular hemorrhages.

Cerebral Hemorrhage↗
PubMed1986

Serum galactosyltransferase as a prognostic marker in patients with solid tumors.

The serum level of galactosyltransferase was measured in a group of 218 patients with a variety of solid tumors and most with advanced disease. The pretreatment enzyme level showed little potential as a diagnostic tumor marker, and its change with treatment did not reflect the initial response. There was, however, a significant correlation between the length of survival and the pretreatment enzyme level. Patients with normal levels survived over twice as long as those with elevated levels. When Cox's proportional hazards regression analysis was used to compare the prognostic potential of galactosyltransferase with a number of known clinical indicators of prognosis, the variable most related to survival was performance status (P less than 10(-4) followed by galactosyltransferase (P = 0.01) and then the extent of disease (P = 0.03). The other variables, such as previous therapy, the type, site, and size of primary tumor, did not contribute significantly to the relationship with survival. The pretreatment level of galactosyltransferase is therefore a relatively independent prognosticator of survival and, as such, could be potentially useful in patient management by increasing the accuracy of the initial assessment of prognosis.

Galactosyltransferases↗
PubMed1982

Neonatal mortality risk in relation to birth weight and gestational age: update.

Neonatal mortality risk for all birth weight-gestational age categories has been prepared based on data from an inborn population at the University of Colorado Health Sciences Center for the years 1974 to 1980. There were 14,413 live births and 252 neonatal deaths during this six-year period, reflecting fairly current clinical practices. Based on birth weight alone, neonatal mortality was 0.47% for infants weighing greater than 2,500 gm; based on gestational age alone, mortality was 0.28% for infants greater than 34 weeks. A chart of neonatal mortality risk has been constructed based on birth weights and gestational ages of all these infants. The zones of mortality risk have been color matched to equivalent areas of mortality for the 1958 to 1969 data previously published from the Center for easy comparison. These two populations have also been compared on a graph plotting the predicted mortality at the estimated gestational age and its fiftieth percentile birth weight. This may be useful for consultation by perinatal obstetricians who must make decisions about transfer and care of high-risk mothers before delivery occurs. Where comparisons can be made with other perinatal centers, there is a remarkable similarity in neonatal survival rates, indicating that continuing communication between obstetric perinatologists and neonatologists is a prime factor in reducing mortality, rather than specific new therapeutic procedures at any single clinical center.

Birth Weight↗
PubMedDate not supplied

Our chemical burn experience: exposing the dangers of anhydrous ammonia.

Although chemical injuries account for only a small number of one burn unit's cases, the diversity, resulting complications, and sequelae of these burns pose special problems. We reviewed a 19-year period of the chemical burn experience of our burn unit. The population of patients with these types of burns consisted of young men (mean age: 29.8 years), the majority of whom were injured on the job. Unique to our series is the largest collection of injuries (30%) resulting from the common fertilizer anhydrous ammonia. Another population of concern, accounting for 14% of the injuries in our unit, is that of patients injured at home with routine household cleaners. Nearly one half of those patients injured at home incurred injuries that required grafting. The cornerstone of chemical burn prevention and treatment involves education regarding the caustic nature of chemicals, proper handling, adequate protection, and copious irrigation of the wound at the scene. From the analysis of our retrospective review, adequate education and treatment at the scene appear to be well implemented in the industrial and farming communities. The focus of our education efforts should be directed toward the public and emphasize the safe use of household chemicals. Finally our review illuminated the potential benefit of immediate excision and grafting for decreasing the length of stay, complications, and loss of productivity.

Adult↗