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Biomedical subjects

C M Williams

Publications and source records attributed to C M Williams.

At least 163 records · Page 9Linked to original sources
PubMed1987

Clinical and microbiologic risk evaluation for post-cesarean section endometritis by multivariate discriminant analysis: role of intraoperative mycoplasma, aerobes, and anaerobes.

The clinical and microbiologic risk factors for postpartum endometritis were studied prospectively in 77 patients undergoing cesarean section without antibiotic prophylaxis at Harbor-University of California at Los Angeles Medical Center. Intraoperative cultures were obtained from the amniotic fluid, lower uterine segment, and abdominal wound for isolation of genital mycoplasmas, aerobes, and anaerobes. Postsection endometritis developed in 21 (27%) patients and was significantly associated with presence of either high-virulence bacteria (predominantly, coliforms, streptococci, anaerobic cocci, and bacteroides) (35% to 60% versus 10% to 24%; p less than 0.05) or Ureaplasma urealyticum (15% to 42% versus 0% to 10%; p less than 0.05) at any site compared with afebrile women. Multivariate analysis identified primary cesarean section, younger maternal age, presence of ruptured membranes, and presence of Ureaplasma as significant risk factors independent of other confounding variables (p less than 0.01). It is suggested that genital mycoplasmas could play a primary role in some cases of postsection endometritis or that they are cofactors or markers for the presence of other high-virulence aerobic and anaerobic bacteria.

Anti-Bacterial Agents↗
PubMed1987

Beta-adrenergic activities of octopamine and synephrine stereoisomers on guinea-pig atria and trachea.

The activities of the (-)- and (+)-forms of m- and p-octopamine and m- and p-synephrine on beta 1- and beta 2-adrenoceptors in guinea-pig atria and trachea have been compared with that of noradrenaline. The rank order of potency of the (-)-forms on beta 1-adrenoceptors was noradrenaline greater than m-synephrine greater than m-octopamine = p-octopamine greater than p-synephrine. m-Synephrine was 100-fold, m- and p-octopamine about 6000-fold, and p-synephrine about 40,000-fold less active than noradrenaline. The (+)-forms were 1-2 orders of magnitude less active than their (-)-counterparts. The four (-)-compounds were more than four orders of magnitude less active than noradrenaline on beta 2-adrenoceptors, and the (+)-forms had no detectable activity in concentrations as high as 10(-4) M. If m- and p-octopamine are co-released with noradrenaline in amounts proportional to their concentration, their activities at these structures are too low to be physiologically significant.

Adrenergic beta-Agonists↗
PubMed1987

Radiation dosimetry of iodine-123 HEAT, an alpha-1 receptor imaging agent.

Biologic distribution data in the rat were obtained for the alpha-1 adrenoceptor imaging agent (+/-) 2-[beta-(iodo-4-hydroxyphenyl)ethylaminomethyl]tetralone (HEAT) labeled with [125I]. The major excretory routes were through the liver (67%) and the kidney (33%). Internal radiation absorbed dose estimates to nine source organs, total body, the GI tract, gonads, and red bone marrow were calculated for the human using the physical decay data for [123I]. The critical organ was found to be the lower large intestine, receiving 1.1 rad per mCi of [123I]HEAT administered. The total-body dose was found to be 58 mrad per mCi.

Adult↗
PubMed1986

Excretion of octopamine metabolites in neuroblastoma.

The urinary concentrations of o-hydroxymandelic acid, m-hydroxymandelic acid, p-hydroxymandelic acid, homovanillic acid and vanillylmandelic acid were determined in 57 healthy children and 9 patients with neuroblastoma. The concentrations of o-hydroxymandelic acid and p-hydroxymandelic were not significantly different for both groups whereas the concentrations of m-hydroxymandelic acid, homovanillic acid and vanillylmandelic acid were elevated 20- to 30-fold in the neuroblastoma patients.

2-Hydroxyphenethylamine↗
PubMed1986

Plasma lipids and prolactin in patients with breast cancer.

In a comparative study of pre- and postmenopausal women with benign and malignant breast disease, a number of differences were observed in circulating plasma prolactin and lipid concentrations. Plasma lipids, phospholipids, triglycerides, cholesterol and free fatty acids were all higher in blood obtained from breast cancer patients prior to surgery. HDL-Cholesterol levels were significantly lower in these patients. These differences remained when the patient groups were sub-divided according to menopausal status. Plasma prolactin concentrations were also found to be higher in cancer compared with non-cancer patients, this effect being more marked in premenopausal than in postmenopausal patients. Premenopausal patients with invasive or poorly differentiated disease had significantly higher prolactin levels than those with non-invasive disease. No correlations were found between plasma prolactin and any of the lipid fractions.

Adult↗
PubMed1986

A longitudinal study of adipose tissue glucose utilization during pregnancy and the puerperium in normal subjects.

A longitudinal study of carbohydrate and lipid metabolism in normal pregnant volunteers demonstrated distinct alterations in maternal fuel utilization as pregnancy progresses. Glucose uptake into maternal adipose tissue and plasma glucose levels were significantly reduced in late pregnancy compared to early pregnancy and post-partum values. Plasma fatty acids, glycerol and ketone levels were elevated in late pregnancy. This confirms the concept of the third trimester as a catabolic phase within the maternal system, and provides support for the view that the insulin resistance of pregnancy may be a compensatory response to overcome the inhibitive effects of metabolites such as fatty acids on peripheral uptake of glucose.

Adipose Tissue↗
PubMed1985

Importance of imaging plane for magnetic resonance imaging of the normal left ventricle.

Visualization of the left ventricle by magnetic resonance imaging (MRI) is largely a function of imaging planes. The best depiction of the myocardium is possible when the imaging plane is perpendicular to the region of interest. The effect of imaging plane on the visualization of the left ventricle has not been fully described. To assess this effect, 10 normal adults underwent electrocardiogram-gated multiplanar cardiac MRI. The imaging planes being evaluated were standard planes, transverse, sagittal and coronal, and modified planes relating to the left ventricular (LV) long axis: coronal long axis parallel to the ventricular septum (VS), sagittal long axis perpendicular to the VS and transverse short axis perpendicular to the VS and long axis. The myocardium was separated into 9 segments. Using each plane, the LV segments were evaluated for quality of LV depiction. The planes based on the LV long axis were superior to standard planes in depicting the LV segments.

Adolescent↗
PubMed1985

Thermogenic and metabolic consequences of thyroid hormone treatment in brown and white adipose tissue.

Male rats were treated with triiodothyronine in the drinking water for 12 days. In vitro rates of isoprenaline stimulated lipolysis were significantly greater in brown but not white adipose tissue. Rates of [14C]glucose incorporation into triacylglycerols were significantly reduced in BAT (brown adipose tissue) and WAT (white adipose tissue) under basal and isoprenaline stimulated conditions. In a second experiment, hyperthyroid animals showed impaired weight gain, despite increased food intake during 19 days' treatment. Energy expenditure on days 5 and 12, and BAT core temperature differences (TBAT - TCORE) on day 19, were significantly greater than in control animals. Epididymal white fat pad weight was reduced and interscapular brown fat pad weight increased by triiodothyronine treatment.

Adipose Tissue↗
PubMed1985

Increased urinary excretion of m-octopamine in neuroblastoma.

The urine of three patients with neuroblastoma was found to have a 3 to 5-fold elevation of m-octopamine concentration. The concentration of m-synephrine was normal in two cases and slightly elevated in the third. These findings were attributed to an increased formation of m-octopamine by this tumor.

2-Hydroxyphenethylamine↗
PubMed1985

Aluminum-based temporary removable partial dentures.

The fabrication of an aluminum-based temporary removable partial denture has been presented. The advantages of this type of prosthesis include compatibility with oral tissues, accuracy of fit, decreased bulk, and improved thermal conductivity.

Aluminum↗
PubMed1985

m-Octopamine: normal occurrence with p-octopamine in mammalian sympathetic nerves.

The development of a radiochemical enzyme assay for p-octopamine in 1969 led to its identification in a large number of invertebrate nerve systems and in mammalian sympathetic nerves. The original method by which p-octopamine was measured has now been found to be nonspecific; however, modifications of this procedure can determine both m- and p-octopamine. We recently developed a new specific method for the unequivocal identification and quantitative determination in tissue of the six octopamine and synephrine isomers. With this method--negative chemical ionization gas chromatography-mass spectrometry--the more physiologically active m-octopamine has been found in association with p-octopamine in 10 organs of the rat. m-Octopamine is present in concentrations equal to those of p-octopamine in heart, spleen, and liver and in concentrations from 30 to 60% of p-octopamine in adrenals, vas deferens, brain, kidney, large intestine, bladder, and lungs. In vivo inhibition of monoamine oxidase markedly increased the concentrations of both m- and p-octopamine in all organs examined. Both amines were virtually absent from all organs except the adrenals following chemical sympathectomy with 6-hydroxydopamine, thereby establishing that m- and p-octopamine are localized within sympathetic nerve endings.

2-Hydroxyphenethylamine↗
PubMed1985

Effect of 6-hydroxydopamine on the metabolism of endogenous octopamines and catecholamines.

The daily excretion in rat urine of o-(OHMA) (0.2), m-(MHMA) (0.9), p-(PHMA) hydroxymandelic acid (78), vanillylmandelic acid (VMA) (3.5) and homovanillic acid (30 micrograms day-1), terminal metabolites of the isomeric octopamines and catecholamines, has been determined by gas chromatography-mass spectrometry. Chemical sympathectomy with 6-hydroxydopamine (i.p.) caused the daily output of each acid (except OHMA) to drop by 50% and that of PHMA was restored to normal the most rapidly after cessation of treatment. These results indicate that m- and p- (but not o-) octopamine coexist with catecholamines in sympathetic nerve terminals, are subject to the same compensatory biosynthetic mechanism following chemical sympathectomy and that p-octopamine has the highest turnover rate of these biogenic amines in the rat.

Animals↗
PubMed1985

Renal morphology and function immediately after extracorporeal shock-wave lithotripsy.

The acute effects of extracorporeal shock-wave lithotripsy (ESWL) on morphology and function of the kidney were evaluated by excretory urography, quantitative radionuclide renography (QRR), and magnetic resonance imaging (MRI) in 33 consecutive patients. Excretory urograms demonstrated an enlarged kidney in seven (18%) of 41 treatments and partial or complete obstruction of the ureter by stone fragments after 15 (37%) of 41 treatments. Total effective renal plasma flow (ERPF) was not changed after ESWL, but the percentage ERPF of the treated kidney was decreased by more than 5% in 10 (30%) of 33 cases. QRR images showed partial parenchymal obstruction in 10 (25%) of 41 treated kidneys and total parenchymal obstruction in 9 (22%). MRI disclosed one or more of the following abnormalities in 24 (63%) of 38 treated kidneys: (1) loss of corticomedullary differentiation, (2) perirenal fluid, (3) subcapsular hematoma, (4) hemorrhage into a renal cyst, and (5) unexplained abnormalities. Treated kidneys were normal by all three imaging methods in 26% and abnormal by one or more tests in 74% of cases. The morphologic and functional changes are attributed to renal contusion resulting in edema and extravasation of urine and blood into the interstitial, subcapsular, and perirenal spaces.

Humans↗
PubMed1984

Effect of intracerebroventricularly administered octopamines and synephrines on angiotensin II-induced water intake in rats.

Recent studies from this laboratory showed that l-m-synephrine (phenylephrine), a metabolite of l-m-octapamine, inhibited the drinking response of rats to peripherally administered angiotensin II. The objective of this investigation was to determine whether the isomers of both octapamine and synephrine could inhibit angiotensin II-induced dipsogenesis in the rat. Of the isomers tested, only d,l-m-octopamine and l-m-synephrine blocked the dipsogenic response to administration of angiotensin II (200 micrograms/kg, SC). The antidipsogenic effect of both d,l-m-octopamine and l-m-synephrine could be blocked by concurrent administration of yohimbine (300 micrograms/kg, IP), an alpha 2-adrenoceptor antagonist. The results indicate that m-octopamine and m-synephrine exert their antidipsogenic effect via alpha 2-adrenoceptors. These studies add to a growing body of data suggesting that activation of alpha 2-adrenoceptors inhibits, while blockade of these receptors enhances, angiotensin II-induced drinking.

2-Hydroxyphenethylamine↗