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Biomedical subjects

W Smith

Publications and source records attributed to W Smith.

At least 271 records · Page 15Linked to original sources
PubMed1987

Analysis of bowel perforation in necrotizing enterocolitis.

The most severe complication of necrotizing enterocolitis (NEC) is bowel perforation. Identification of neonates at high risk for perforation and optimization of radiologic imaging to identify bowel perforation are necessary to reduce the high mortality rate associated with this catastrophic event. One hundred and fifty-five cases of NEC were seen at our institution during a 5.5-year period. Nineteen (12%) progressed to perforation. A review of surgical findings, autopsy results and radiographs from these patients shows only 63% had radiographic evidence of free air in the peritoneal cavity at the time of perforation. Twenty-one percent had radiographic evidence of ascites but no pneumoperitoneum, and 16% had neither free air nor ascites. Thus purely radiographic criteria for bowel perforation in NEC are imprecise, and paracentesis is mandatory in NEC patients with ascites or clinical findings indicative of peritonitis. Timing of radiographic studies and site of bowel involvement are also important. Seventy-nine percent of perforations occurred by 30 h from confirmation of diagnosis (by clinical or radiographic criteria). Surgery or autopsy revealed involvement of the ileo-cecal region in 89% of cases with the actual site of perforation occurring in this area in 58% of patients.

Enterocolitis, Pseudomembranous↗
PubMed1987

Locomotion-inducing sites in the vicinity of the pedunculopontine nucleus.

The mesencephalic locomotor region (MLR) was identified physiologically by inducing controlled locomotion on a treadmill in the precollicular rat following application of low amplitude current pulses to areas of the pontomesencephalic tegmentum. The same brains were processed using either of two techniques known to label neurons of the pedunculopontine nucleus (PPN)-choline acetyltransferase (ChAT) immunocytochemistry or nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase histochemistry. Histological reconstruction of locomotion-inducing sites were localized within or adjacent to ChAT or NADPH-diaphorase labeled cell groups. Three dimensional reconstructions of the PPN were used to visualize the colocalization of low threshold locomotion-inducing stimulation sites within PPN neuronal aggregates. These findings lend further support to the suggestion that the PPN is part of the MLR. A theoretical framework is proposed to account for results derived from various lines of research on this area.

Animals↗
PubMed1987

IgG (kappa) paraproteinaemia and arthritis.

Three patients with IgG (kappa) paraproteinaemia in association with inflammatory polyarthritis are described. Two of the patients had an erosive deforming arthritis, and the third had a non-erosive arthritis and necrotizing vasculitis. Possible aetiological relationships between the paraproteinaemia, arthritis and vasculitis are discussed.

Arthritis↗
PubMed1987

Measurement of right ventricular volume using cine computed tomography.

Volume measurements of the right ventricle are clinically important, particularly in the assessment of congenital heart disease. The complex configuration of the right ventricular cavity, however, makes assessment of its volume difficult. Cine computed tomography (CT) permits depiction of cardiac anatomy in parallel, sequential, high-resolution tomographic images. To test whether cine CT would allow accurate, reproducible determination of right ventricular volumes, 11 excised, fixed canine hearts were scanned ex vivo. The endocardial contours of the right ventricular cavity were traced by two independent observers. The right ventricular cavity areas were measured in each image and right ventricular volume calculated by a Simpson's rule approximation. Actual right ventricular volume (range 24-86.5 mL) was measured by cavity fluid capacity. Right ventricular volumes derived from cine CT data correlated closely with actual volumes (R = .96, cine CT volume = 0.99 X [actual volume] + 0.2 mL). Interobserver correlation was excellent (R = .99). It is concluded that cine CT scanning permits accurate, reproducible determination of right ventricular volume ex vivo. This technique should be immediately applicable to the noninvasive evaluation of right ventricular function in children and adults.

Animals↗
PubMed1987

Reversal of progressive renal allograft dysfunction with OKT3.

The safety and efficacy of treatment with Orthoclone OKT3 was evaluated in 14 renal transplant patients with allograft dysfunction unresponsive to conventional therapy. Eleven of the 14 initially improved on OKT3, and 9 have retained their kidneys after a median 13-month follow-up. The mean serum creatinine among successes is 2.4 mg/dl. It is concluded that OKT3 is a safe and effective drug for treatment of rejection, and may be used during temporary discontinuation of ciclosporin in cases in which nephrotoxicity is questioned.

Antibodies, Monoclonal↗
PubMed1987

Oocyte maturity and human follicular fluid prostanoids, gonadotropins, and prolactin after administration of clomiphene and pergonal.

Follicular fluid (FF) and oocytes were obtained from 130 follicles of 52 women in whom ovulation was induced with human menopausal gonadotropin (Pergonal) and clomiphene citrate. Follicular aspiration was performed 36 h after an ovulatory injection of hCG. The concentrations of LH, FSH, PRL, and the prostanoids prostaglandin E2 (PGE2), PGF2 alpha, PGI2 (as 6-oxo-PGF2 alpha), and thromboxane A2 (as TXB2) in the FF were measured by RIA and related to the degree of maturation of the oocyte-corona-cumulus complex mass (OCCC). FF obtained from follicles with immature OCCC contained significantly lower concentrations of all four prostanoids (median concentrations, picograms per mL: PGE2, 88; PGF2 alpha, 85; 6-oxo-PGF1 alpha, 40; TXB2, 50) than those with intermediate OCCC (PGE2, 175; PGF2 alpha, 325; 6-oxo-PGF1 alpha, 130; TXB2, 65) and mature OCCC (PGE2, 425; PGF2 alpha, 860; 6-oxo-PGF1 alpha, 235; TXB2, 78; all P less than 0.01). There were no significant differences between the maturity of the complexes and the concentrations of LH, FSH, or PRL. There were significant correlations between the FF concentrations of LH and FSH and those of all of the prostanoids, but not with PRL, concentrations. These results indicate that the synthesis of prostanoids in the human Graafian follicles may be modulated by gonadotropins and consolidates the view that prostanoids may play a role in human oocyte maturation and ovulation.

6-Ketoprostaglandin F1 alpha↗
PubMed1987

Xiaoke, a traditional Chinese treatment for diabetes. Studies in streptozotocin diabetic mice and spontaneously diabetic BB/E rats.

Xiaoke tea is consumed as a traditional herbal treatment for diabetes mellitus in China. An aqueous extract of Xiaoke (1 g of dried plant preparation in 64 ml of water), supplied ad lib in place of drinking water during the induction and development of streptozotocin diabetes in mice, reduced (about 30%) plasma glucose concentrations by 25 days. The polydipsia and hyperphagia of the streptozotocin diabetic mice were also reduced by Xiaoke, and the effects lapsed after treatment was withdrawn. Xiaoke did not significantly alter plasma insulin concentrations. Consumption of the Xiaoke extract by insulin-treated diabetic BB/E Wistar rats did not affect glycaemic control or body wt. When insulin treatment was reduced and discontinued, Xiaoke failed to prevent the progression of severe hyperglycaemia and weight loss. The results suggest that the slowly generated antihyperglycaemic effect of Xiaoke in streptozotocin diabetic mice may involve an extrapancreatic effect on food intake, glucose production or glucose clearance. However, as evidenced in BB/E rats, Xiaoke does not substitute for insulin in the absence of endogenous insulin secretion.

Animals↗
PubMed1986

Transluminal laser irradiation of coronary arteries in live dogs: an angiographic and morphologic study of acute effects.

In vivo coronary transluminal laser irradiation, using energies known to vaporize atherosclerotic plaques and thrombi, was performed in normal coronary arteries of 5 anesthetized mongrel dogs. A 200-mu core silica optical fiber with a radiopaque tip was advanced through a catheter to either the left anterior descending or circumflex coronary arteries. Coronary artery perforation occurred during manipulation of the fiber in 1 dog. In 4 dogs, argon laser radiation was delivered at 1-second intervals. A total of 45 different sites were irradiated in 8 coronary arteries. In 5 of these arteries 1 W was used and in the 3 other arteries 2 W were used. Coronary angiography showed perforation of 5 of these 8 arteries. Two arteries were perforated using 1 W and 3 using 2 W. Within 30 minutes, 3 dogs with perforation died of cardiac tamponade. In all 4 dogs postmortem examination showed perivascular blood extravasation around all 8 lased coronary arteries. Transluminal lasing of normal dog coronary arteries using delivery systems and energies similar to those known to vaporize atherosclerotic plaques and thrombi resulted in arterial perforation, frequently followed by cardiac tamponade.

Angiography↗
PubMed1986

Drug localisation and growth inhibition studies of vindesine-monoclonal anti-CEA conjugates in a human tumour xenograft.

The distribution of tritiated vindesine (3H-VDS) was studied in the tissues and tumours of athymic mice bearing a human colorectal tumour xenograft. Selective tumour localisation was obtained when 3H-VDS was injected as a conjugate with a monoclonal anti-CEA antibody (11.285.14) but not as a conjugate with a non-binding monoclonal IgGl (Ag8) or as free succinoyl-VDS. The amounts of VDS that localised in the tumour following injections of 3H-VDS-11.285.14 increased in proportion to the amount injected, over a wide dose range. Conjugates prepared using the Fab fragments of 11.285.14 showed no evidence of selective tumour uptake in comparison with normal tissues. Various dose levels of VDS-11.285.14 conjugate and free VDS were studied for effects on the growth of the tumour xenograft. A growth inhibition of 50% was obtained at 1.5 mg/kg with free VDS and at 2.5 mg/kg with conjugated VDS. The conjugate was, however, considerably less toxic.

Animals↗
PubMed1986

MR findings of malignant intracranial teratoma in a neonate.

Intracranial teratomas are the most common intracranial tumor in newborns. Their clinical symptoms are ambiguous but they have a characteristic pattern of a bulky midline lesion with a solid component, multiple loculated cysts and occasionally calcifications. This pattern is easily evident on cranial MR examination.

Brain Neoplasms↗
PubMed1986

Cine CT diagnosis of pulmonary artery sling.

This report documents the use of a Cine CT scanner for documentation of pulmonary artery sling. The examination can be carried out on outpatients and involves only a peripheral venous contrast injection. Excellent visualization of the anatomy is obtained.

Cineangiography↗
PubMed1986

Detection of heterotopic gray matter in children by magnetic resonance imaging.

Heterotopic gray matter results from abnormal brain development and is a recognized focus of seizures. It may be associated with mental retardation and/or severe malformations of the brain. Three patients with heterotopia of gray matter were identified by magnetic resonance imaging (MRI). CT failed to detect the heterotopic gray matter in each case. One child was referred for removal of a neoplasm based on CT studies until MRI demonstrated the developmental nature of his condition. One infant had severely dysplastic left cerebral hemisphere associated with heterotopic gray matter and the syndrome of Hypomelanosis of Ito. All three children suffered from seizures and/or mental retardation. MRI provided important information in the management of each case and appears to be the imaging method of choice in evaluating children with seizures or retardation for heterotopic gray matter in the brain.

Brain Neoplasms↗