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Biomedical subjects

S M Scott

Publications and source records attributed to S M Scott.

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

Intravenous infusion of prostaglandin E1 (PGE1) in management of limb ischemia.

Twenty-three patients who had advanced arteriosclerotic disease of the lower extremities as manifested by rest pain, nonhealing ischemic ulcers, or impending gangrene and who were not candidates for direct arterial revascularization procedure underwent intravenous infusion of prostaglandin E1 (PGE1). Thirty-nine per cent of the patients showed subjective and/or objective improvement in the blood supply, and in 22 per cent (5 patients) amputation was avoided. Complications were minor and disappeared once the infusion was discontinued. PGE1 in prescribed dosages can be safely infused intravenously. Even though the results are not as encouraging as when PGE1 is given by the intra-arterial route, IV therapy improves the ischemic symptoms and avoids the necessity of amputation in some patients.

Adult↗
PubMed1984

Effect of calcium therapy in the sick premature infant with early neonatal hypocalcemia.

Twenty-seven sick premature infants with serum calcium concentrations less than 6.0 mg/dl during the first day of age were enrolled in a prospective controlled study involving two treatment regimens--calcium given as a bolus or a drip--or no treatment. Mean total calcium concentration was 5.5 +/- 0.8 mg/dl, and ionized calcium was 3.1 +/- .3 mg/dl, with no significant difference between treatment groups. By 24 hours, in all groups total calcium had increased to greater than 6.0 mg/dl (bolus 6.5 +/- 1.1, drip 7.0 +/- 0.4, control 6.6 +/- 0.4) and ionized calcium to greater than 3.5 mg/dl (bolus 3.9 +/- 0.3, drip 3.6 +/- 0.6, control 3.6 +/- 0.3). Ionized and total calcium concentrations were significantly correlated (r = 0.562; P less than 0.001), but total calcium did not predict ionized calcium in any group. These data support the concept that, even in sick infants, early neonatal hypocalcemia is a physiologic phenomenon that may not require treatment.

Adult↗
PubMed1983

The effect of concanavalin A on egestion of food vacuoles in Tetrahymena.

The ability of concanavalin A (conA) to disrupt food vacuole elimination at the cytoproct of Tetrahymena pyriformis, strain GL-C, was investigated using fluorescence microscopy and thin section electron microscopy. ConA was found to induce "tails" in Tetrahymena. These tails were specifically stained by fluorescent conA. Thin section observations of conA-treated cells revealed that these tails were the result of abnormal egestion of food vacuole contents at the cytoproct. Tail formation appears to result from an inhibition of endocytosis of food vacuole membrane during egestion. Instead, the food vacuole membrane appears to be cast out of the cell, along with the contents of the vacuole. The mechanism of this inhibition may be related to an apparent absence of microtubules or microfilamentous mat in the cytoproct region of conA-treated cells. Although conA is ingested into food vacuoles in large amounts, conA appears to affect endocytosis only from outside the cell; ingested conA does not appear to be effective. ConA may exert its influence by binding to the cytoproct region. The ability of conA to induce tail formation is inhibited by sugars specific to it. Numerous membranous vesicles are found in association with the oral cilia and cytoproct region of conA-treated cells. These vesicles may be the conA-binding material reported to be secreted by Tetrahymena.

Animals↗
PubMed1983

Tension pneumoperitoneum and gastric rupture following cardiopulmonary resuscitation.

Inadvertent esophageal intubation during cardiopulmonary resuscitation following aortocoronary bypass grafting resulted in gastric rupture and tension pneumoperitoneum in a 65-year-old patient. Rapid hemodynamic deterioration necessitated emergency laparotomy with successful repair of the gastric rupture. The patient's recovery was uneventful, and he was doing well at six months follow up. Awareness of this unusual complication may lead to early recognition and successful treatment.

Aged↗
PubMed1983

Effect of thyroid hormones on epidermal growth factor concentration in neonatal mouse skin.

T4 and epidermal growth factor (EGF), given exogenously, both promote similar maturational events in the skin of newborn mice, i.e. precocious incisor eruption and eyelid opening. Moreover, T4 markedly increases the concentration of EGF in developing mouse submandibular glands. To examine the effect(s) of thyroid hormones on local cutaneous levels of EGF, a rapid and sensitive double antibody RIA was developed and standardized for newborn mouse skin. After fixed daily injections of T4, immunoreactive EGF concentrations in whole skin homogenates showed a dose-dependent increase when measured on postnatal days 4, 6, and 17. A similar increase was seen after T3 treatment, but administration of the structurally similar, metabolically inactive analog rT3 produced no significant effect on EGF concentrations. Induction of experimental hypothyroidism with propylthiouracil (PTU) and methimazole produced a relative decrease in skin EGF levels on postnatal day 8. Maternal sialoadenectomy did not result in a significant decrease in neonatal skin EGF, suggesting the presence of an extrasalivary source(s). These studies suggest that the epidermal maturation that follows thyroid hormone administration is mediated by local tissue levels of EGF. Moreover, the results admit of a possible physiological relation between thyroid hormones and EGF during postnatal cutaneous development.

Animals↗
PubMed1983

Nerve growth factor concentration in a congenitally hypothyroid mouse model (hyt/hyt) and its responsivity to thyroxine treatment.

Earlier our laboratory reported the ontogenic profiles of serum thyroxine (T4) and triiodothyronine (T3) concentrations and nerve growth factor levels in the submandibular gland of Swiss-Webster mice. Further, we demonstrated a responsivity of submandibular gland-nerve growth factor concentrations to exogenously administered T4. To further our understanding of the interactions between thyroid hormones and submandibular gland-nerve growth factor we utilized a congenitally hypothyroid mouse model to examine submandibular gland-nerve growth factor in euthyroid, hypothyroid and hypothyroid-T4 replaced mouse pups. Serum T4 values in the congenitally hypothyroid (hyt/hyt) mice were unmeasurable and their growth in body weight, their incisor eruption, and their eyelid opening were significant delayed. Submandibular gland/body weight ratios were significantly reduced relative to control or heterozygous (+/hyt) animals through 40 days. The increase in submandibular gland-nerve growth factor concentrations observed in normal animals before 20 days was delayed to 35 days in the (hyt/hyt) animals. T4 treatment of (hyt/hyt) animals from 11 or 18 days of age significantly increased mean 40 day submandibular gland/body weight ratios and submandibular gland-nerve growth factor concentrations. However, the 40 day submandibular gland-nerve growth factor levels in treated animals remained significantly below the level of control euthyroid mice. Thus, the possibility of critical time of thyroid hormone replacement for normal submandibular gland maturation has not been shown but must be further explored in this model.

Animals↗
PubMed1982

Dimensional characteristics of left ventricular function after coronary artery bypass grafting.

During coronary artery bypass grafting, 20 patients underwent epicardial placement of miniature ultrasonic dimension transducers across the minor-axis diameter of the left ventricle to monitor cardiac function postoperatively. Left atrial or left ventricular pressure was measured in all patients, and thermodilution cardiac outputs were obtained routinely. Data from 1, 6, 12 and 20 hours postoperatively were analyzed. Directional changes in systolic shortening of the left ventricular diameter correlated well with stroke volume measured by thermodilution techniques and could be used as an on-line index of cardiac output. In five patients who had preoperative abnormalities in wall motion, systolic bulging of the minor-axis diameter was seen initially after revascularization and then gradually resolved over the next 12 hours. Systolic bulging that did not resolve was the earliest indication of a perioperative myocardial infarction in another patient. The end-diastolic diameter increased progressively in all patients in the first 12 hours postoperatively and was associated with stabilization of cardiac function. This improvement in diastolic left ventricular filling was not reflected (p greater than 0.2) by changes in mean left atrial pressure. Therefore, ultrasonic assessment of left ventricular diameter is a simple, precise and safe method of monitoring systolic and diastolic ventricular function postoperatively.

Adult↗
PubMed1981

Bioassay detection of mouse nerve growth factor (mNGF) in the brain of adult mice.

Two pools of seven brains each from adult Swiss-Webster mice were homogenized, and supernatants were collected for bioassay. PC-12 cells were placed in a bioassay plate at time zero, at a concentration of 10(4) cells per well, and primed for 48 hours in a medium containing 50 ng/ml of mNGF. The PC-12 cell bioassay for neurite outgrowth was conducted after primed cells were exposed to an NGF-free medium for 24 hours. Suitable controls for serum toxicity and cell viability were established. The sensitivity of the bioassay approximates 100 pg NGF/ml. The results showed 80-100% neurite outgrowth in wells exposed to brain pool supernatant (BPS) alone, and control level outgrowth (3-8%) in wells containing BPS and specific anti-beta-NGF antibody. Therefore, the brains of Swiss-Webster adult mice contain an NGF-like substance which promotes neurite outgrowth in PC-12 cells. The substance probably is NGF itself, since the effect is blocked by specific NGF antiserum.

Animals↗
PubMed1981

Nerve growth factor in human umbilical cord serum: demonstration of a veno-arterial gradient.

An heterologous radioreceptor assay (RRA) for nerve growth factor (NGF) has been developed to measure NGF in human umbilical cord serum. The RRA uses mouse NGF (mNGF) as iodination material and as standard and a rat pheochromocytoma clonal line of cells (PC-12) as a source of NGF receptor (KD = 3.8 X 10(-9)M). Human cord serum exhibited parallel displacement of radiolabeled NGF in the RRA. Umbilical vein and artery NGF concentrations were measured in 22 healthy, full-term infants. The mean and (SEM) umbilical vein NGF concentration (30.4 +/- 3.2 pM/ml) significantly exceeded the mean umbilical artery NGF concentration (22.4 +/- 3.3 pM/ml) (p less than 0.05). Cord serum also produced a positive bioassay response (neurite outgrowth) in PC-12 cells, and this response was inhibited by anti-hNGF antiserum. These results are compatible with placental synthesis and secretion of NGF and suggest the possibility that NGF may play a role in autonomic and perhaps central nervous system maturation in the human fetus.

Fetal Blood↗
PubMed1980

Acquired left ventricular-right atrial fistula following aortic valve replacement.

Intracardiac communications produced as a complication of valve replacement can result in left-to-right shunts and a poor surgical result. The successful surgical closure of a left ventricular-right atrial fistula following aortic valve replacement is discussed. The intricate relationships of the membranous interventricular septum, the aortic, mitral, and tricuspid valves, and the aortic root predispose to the creation of abnormal intracardiac shunts when aggressive debridement of extensive valvular calcification is performed at the time of valve excision and replacement.

Aged↗
PubMed1980

Engaging "resistant" families in treatment. I. Getting the drug addict to recruit his family members.

For family therapy to have any effect on correcting drug problems, the family must obviously be involved. However, such families are often resistant to treatment. This paper describes techniques in working with the addicted member toward recruiting his family for therapy. A sequential approach to the initial interview is presented. Interview rationale, structure, and strategy are outlined, along with examples of common resistances and therapeutic counters. The model and techniques are potentially applicable to other types of symptomatic families as well.

Family Therapy↗
PubMed1980

Pulmonary hemorrhage associated with balloon flotation catheters: report of a case and review of the literature.

The development of the flow-directed balloon catheter has greatly facilitated the monitoring of seriously ill patients. As the use of this catheter has increased, so have the reports of complications, the most serious of which is fatal pulmonary hemorrhage. Eleven cases of pulmonary hemorrhage have been described in the literature, and we have reported an additional case. The presenting symptom in 10 patients was hemoptysis, and the course of eight of these patients was rapidly fatal. The most frequent significant finding at autopsy was a laceration of a small peripheral pulmonary artery, usually at a bifurcation. The pathogenesis, prophylaxis, and management of this complication are discussed.

Cardiac Catheterization↗