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Biomedical subjects

D Adams

Publications and source records attributed to D Adams.

At least 217 records · Page 12Linked to original sources
PubMed1984

Clinical results and concentrations of cefmenoxime in serum, amniotic fluid, mother's milk, and umbilical cord.

Cefmenoxime administered intravenously was used to treat a variety of gynecologic and obstetric infections in 40 patients. Many were mixed infections. The mean age of the patients was 39.7 +/- 2.39 years. The dosage of cefmenoxime was 2 g per day (n = 30) or 1 g per day (n = 10). Cefmenoxime levels were assayed microbiologically in serum, milk, amniotic fluid, and placental tissues. The overall bacteriologic cure rate was 86 percent. Clinically, 100 percent of the patients were treated successfully. Side effects were generally mild, and in no case was treatment discontinued. Twelve hours after the last bolus injection, levels of cefmenoxime were 1.1 microgram/ml in serum and 1.75 microgram/ml in milk. Thirty minutes after a 1 g bolus injection in patients undergoing cesarean section, mean maternal serum concentrations were 33 micrograms/ml. Concentrations were 7.4 micrograms/ml in umbilical cord blood and 2.3 micrograms/ml in amniotic fluid.

Adult↗
PubMed1984

The response of bone to carbon--carbon composites.

A cloth-sandwich construction of a carbon-carbon composite material has been implanted in the femora of a series of rats and the response of the bone to this material compared to the response to titanium. It is shown that the carbon provides for excellent hard tissue biocompatibility. When the composite has a surface texture associated with fibre run out there is a degree of bony attachment, the interfacial shear strength for the composite-bone system being significantly greater than that for the titanium-bone system during the period 4-40 weeks post implantation.

Animals↗
PubMed1984

Coexisting thyroid and gastric autoimmune diseases are not due to cross-reactive autoantibodies.

Some autoimmune diseases tend to cluster within families, patients with one such disease showing an increased tendency to develop certain other autoimmune diseases within the same group. We have investigated the possibility that this clustering arises because some patients produce autoantibodies which cross-react with antigenic determinants which are shared by diverse tissues. Our data indicate that this is not the case, at least so far as thyroid and gastric autoimmune diseases are concerned. This observation increases the likelihood that the real explanation for such clustering concerns sharing of idiotypic determinants by the different pathogenic clones involved or by their precursors.

Anemia, Pernicious↗
PubMed1983

Abnormal responses to the carcinogen 4-nitroquinoline 1-oxide of cultured fibroblasts from patients with dysplastic nevus syndrome and hereditary cutaneous malignant melanoma.

The dysplastic nevus syndrome (DNS) is a preneoplastic melanocyte abnormality which occurs in families affected by hereditary cutaneous malignant melanoma (HCMM). A putative role of host-environmental interactions in the etiology of hereditary melanoma has been strengthened by the recent finding that fibroblasts derived from HCMM/DNS patients demonstrated enhanced sensitivity to u.v.-irradiation in vitro. We report here an extension of these studies in which we have examined the in vitro responses to a model environmental carcinogen, 4-nitroquinoline 1-oxide (4NQO), of six non-tumor skin fibroblast strains from HCMM/DNS patients representing five families. Three of the six HCMM/DNS strains showed enhanced cell killing with sensitivities greater than that of a xeroderma pigmentosum (XP) variant strain but less than those of ataxia telangiectasia and XP Group D cell strains. The inhibition and recovery of de novo DNA synthesis, together with the expression of repair synthesis, following 4NQO exposure appeared to be normal in HCMM/DNS strains, irrespective of their subsequent clonogenic potential. Our data point to a metabolic anomaly which may contribute to the carcinogenic risk of the melanoma prone preneoplastic state presented by some DNS patients.

4-Nitroquinoline-1-oxide↗
PubMed1983

Aeromonas hydrophila typing scheme based on patterns of agglutination with erythrocytes and yeast cells.

An agglutination typing scheme has been developed for strains of Aeromonas hydrophila. Primary agglutination typing is based on testing agar-grown A. hydrophila cells with human, horse, rat, and guinea pig erythrocytes and Saccharomyces cerevisiae cells. Further subdivision of primary groups is based firstly on whether yeast cell agglutination is inhibited by a D-mannose polymer, yeast mannan, and secondly on patterns of inhibition of hemagglutination by yeast mannan and the monomeric sugars L-fucose, D-galactose, and D-mannose. A total of 320 isolates were tested, and these were divisible into 39 distinct types on the basis of this scheme. Application of this typing scheme in the future to isolates of A. hydrophila known to be associated with human infection may enable correlations to be made between particular agglutination types and human pathogenicity.

Aeromonas↗
PubMed1983

Liquid-chromatographic quantification of piracetam.

Piracetam, an analog of gamma-aminobutyric acid, absorbs maximally at 197 nm. Its molar absorptivity at 208 nm and pH 4.5 is 3576 (SD 251) L . mol-1 cm-1, approximately 45% of its absorptivity at 197 nm. Direct quantification of piracetam at 197 nm in biological extracts is complicated by the fact that many other compounds absorb between 190 and 220 nm due to carbon-nitrogen bonding. Chromatography of methanol extracts of serum and aqueous humor on a reversed-phase C-18 column developed isocratically with KH2PO4 (0.1 mol/L, pH 4.8) allows detection and quantification of 0.2 mmol of piracetam per liter. Under these conditions the retention time of piracetam is about 5 min. The detector response is linear for quantities between 5 and 15 nmol. The method is rapid, inexpensive, and convenient for the clinical laboratory.

Animals↗
PubMed1982

The identification of specific brain nuclei in which catecholamine turnover is increased by left ventricular receptors during acute myocardial infarction in the rat.

Central catecholaminergic nerves have been shown to participate in the integration of cardio-cardiac reflexes induced by coronary artery ligation in the rat. In this study we measured the turnover of dopamine, norepinephrine and epinephrine in microdissected brain regions to identify some of the specific neural loci involved in this integration. Three groups of rats, treated with alpha-methyltyrosine, an inhibitor of catecholamine biosynthesis were examined: left coronary artery ligation, left coronary artery ligation with the left ventricle painted with lidocaine, and sham operation. An untreated group of resting rats was also examined. Dopamine, norepinephrine and epinephrine turnover was increased in ligated rats in nucleus tractus solitarius (right and left), nucleus commissuralis, A1-region, locus coeruleus, nucleus cuneatus, and area postrema in the pons-medulla and nucleus dorsomedialis in the hypothalamus. Norepinephrine and dopamine (but not epinephrine) turnover was increased in nucleus ambiguus in the brain stem and nucleus paraventricularis in the hypothalamus. A ligation-induced increase in norepinephrine turnover, alone, was exhibited by the A2-region and nucleus gigantocellularis in the medulla and nucleus supraopticus and nucleus hypothalamicus posterior in the hypothalamus. Dopaminergic nerves to the nucleus gigantocellularis appeared to be inhibited following coronary ligation. The catecholamine stores of 11 nuclear regions were not influenced by coronary artery occlusion. Topical lidocaine, applied to the ischemic left ventricle, only, of ligated rats, completely restored regional brain catecholamine turnover to that found in sham-operated animals. In conclusion, we have identified discrete loci in the brain in which catecholamine turnover (as measured by alpha-methyltyrosine induced disappearance) is increased by the stimulation of left ventricular receptors during acute myocardial ischemia in the rat.

Animals↗
PubMed1982

A 1/3 octave-band noise generator for sound-field audiometric measurements.

The design of a low-cost 1/3 octave-band noise generator is presented. This device produces 1/3 octave bands of noise with center frequencies from 100 to 10,000 Hz using a recently introduced switch-capacitor filter with a frequency response which is similar to that of the 1/3 octave filters in the GR 1925 multifilter. The spectrum level of the noise bands produced by this device falls at a rate of 60 dB/octave or more. The noise generator may be used with an audiometer for sound-field measurements in non-anechoic audiometric testing rooms or for earphone measurements. It may also be used as a 1/3 octave-band filter with a center frequency from 100 to 10,000 Hz or as an octave-band filter with a center frequency from 125 to 8000 Hz.

Acoustic Stimulation↗
PubMed1981

Inhibition of serotonin synthesis within the medulla and posterior hypothalamus by cardiac vagal afferents during acute myocardial ischemia in the rat.

Serotonin synthesis, as estimated by the accumulation of 5-hydroxytryptophan 25 min following aromatic-L-amino acid decarboxylase inhibition, was measured in the medulla, pons-midbrain and posterior and anterior hypothalamus of rats subjected to left coronary artery ligation and their sham-operated controls. Left coronary artery ligation led to reduction in the rate of serotonin synthesis in the medulla and posterior hypothalamus. The topical administration of lidocaine to the left ventricle or vagotomy completely obviated these occlusion-induced changes. We conclude that there is an inhibition of serotonergic activity in the medulla and posterior hypothalamus after left coronary artery occlusion in the rat. The afferent signal arises from receptors in the ischemic left ventricle and is conducted by the vagus.

Afferent Pathways↗
PubMed1981

Fistula in ano.

An eight year retrospective review of 133 patients with fistula in ano found the majority to be of cryptoglandular causation. Many patients had symptoms for longer than one year. Operation was performed safely under spinal anesthesia, locating the internal opening in 117 patients, performing a fistulectomy in 80 patients and a fistulotomy in the remainder. Associated procedures, such as a hemorrhoidectomy, could be performed safely. Early recurrence of a fistula, spinal headache, bleeding and temporary incontinence were the complications present in 14 patients. All patients with an early recurrence had undergone a fistulotomy.

Adult↗