Search PubMed⌕ Search

Biomedical subjects

A R Smith

Publications and source records attributed to A R Smith.

At least 109 records · Page 6Linked to original sources
PubMed1989

The pathogenesis of genitourinary prolapse and stress incontinence of urine. A histological and histochemical study.

Histological and histochemical analysis of biopsy samples of pubococcygeus muscle obtained from asymptomatic women and from women with stress incontinence of urine, with or without genitourinary prolapse, have been compared. In the asymptomatic women both age and parity appeared to be related to the morphological features of the samples and in particular those obtained from the posterior part of the pubococcygeus. In the symptomatic women there was a significant increase in the number of muscle fibres showing pathological damage which were obtained from the posterior part of the pelvic floor. The range of diameters of both Type I and Type II fibres obtained from this region was significantly different between symptomatic and asymptomatic women. These findings may be attributable to partial denervation of the pelvic floor in patients with urinary stress incontinence with or without genital tract prolapse.

Adult↗
PubMed1989

The role of partial denervation of the pelvic floor in the aetiology of genitourinary prolapse and stress incontinence of urine. A neurophysiological study.

Single-fibre electromyography of the pubococcygeus muscle of the pelvic floor was performed in 69 asymptomatic women and 105 women with stress incontinence of urine or genitourinary prolapse or both. The results suggest that partial denervation of the pelvic floor with subsequent reinnervation is a normal accompaniment of ageing and is increased by childbirth. Women with stress incontinence of urine or genitourinary prolapse or both have a significant increase in denervation of the pelvic floor compared with asymptomatic women.

Adult↗
PubMed1989

The role of pudendal nerve damage in the aetiology of genuine stress incontinence in women.

Conduction was studied in the terminal branches of the pudendal nerve in 42 women with normal urinary control and 87 women with stress incontinence of urine, genitourinary prolapse, or both. Women with stress incontinence of urine had delayed conduction to both the striated urethral muscle and the pelvic floor muscle, indicative of denervation injury. Women with normal urinary control and genitourinary prolapse had similar conduction times to the urethral sphincter striated muscle as normal women but clear evidence of denervation damage to the pelvic floor.

Female↗
PubMed1988

Late effects of fractionated pi-mesons compared to X rays on mouse lung.

Early and late delayed effects of up to 20 fractions of pions and X rays were investigated in the mouse lung. The whole thorax of female CD-1 mice was irradiated under Ethrane/O2 anesthesia. Respiration rate was measured by whole body plethysmography at biweekly to monthly intervals. With signs of irreversible respiratory distress, animals were sacrificed and their lungs evaluated histologically. In addition to the effect of fractionation, the influence of dose-rate and anesthesia was studied as well. The degree of injury for the most predominant lesions (macrophage accumulation, fibrosis, vascular congestion) was scored, and the correlation with the relative change in respiratory rate and survival was analyzed. This analysis showed the primary lesion to be radiation pneumonitis at a median survival time of approximately 100 days. Focal fibrosis was observed to occur soon thereafter, and no evidence was obtained for an independent second wave of fibrotic injury. Fibrosis seemed primarily the result of pathological organization in areas with heavy concentration of macrophages. It was observed that the mice were unusually sensitive, with a single dose X ray ED50/180 of 8.8 Gy. A similar value was found for unanesthetized mice. This might have been the result of performing these studies at an altitude of 2100 m. The fractionation effect also seemed more pronounced, with alpha/beta values of 0.6 Gy for X rays and 4 Gy for pions, which is significantly lower compared to reported values. At the pion dose-rate of 0.25 Gy.min-1, RBE values for single doses were 0.9 when compared to high dose-rate X rays, and 1.36 at equivalent dose rates. This clearly shows that significant repair occurs during the relatively low dose-rate pion irradiations. With smaller doses per fraction, the dose-rate effect became less dominant, and for 20 fractions of pions the RBE was 1.4 compared to fractionated high dose-rate X rays. These RBE's are similar to values reported for acute effects in skin.

Acute Disease↗
PubMed1988

Maximum hypothermic ischemia in replants containing muscular tissue.

Excision and replantation of the latissimus dorsi muscle of the rabbit was done after various periods of hypothermic ischemia (5 degrees C). Sections studied under the light microscope were classified as having minimal changes, slight degenerative changes, severe degenerative changes, or necrosis. In all sections of the 24-hour group total or nearly total necrosis was found. In the 5-, 8-, and 16-hour groups slight degenerative changes and severe degenerative changes, with a severe reactive proliferation of fibroblasts were seen. A sliding scale was found in which severe degenerative changes were seen more often as ischemia time lasted longer. No statistical significance was found between the various groups.

Animals↗
PubMed1988

Microbial transformation of the pyrethroid insecticides: permethrin, deltamethrin, fastac, fenvalerate, and fluvalinate.

Pure cultures of Bacillus cereus, Pseudomonas fluorescens, and Achromobacter sp. were shown to transform five pyrethroid insecticides in the presence of Tween 80. One of the major products, 3-phenoxybenzoic acid, was further transformed to 4-hydroxy-3-phenoxybenzoic acid. Permethrin was the most rapidly transformed of the pyrethroids, with a half-life of less than 5 days.

Alcaligenes↗
PubMed1987

Structure of the sidechain of lipopolysaccharide from Erwinia amylovora T.

The sidechain of lipopolysaccharide from Erwinia amylovora T was composed of D-fucose, D-galactose and D-glucose in equimolar proportions. Using NMR spectroscopy, methylation analysis, mass spectrometry, Smith degradation and optical rotation data, the repeat unit was shown to have the following most probable structure: (formula; see text)

Carbohydrate Conformation↗
PubMed1987

Long-term results of pion therapy at Los Alamos.

Two hundred twenty-eight patients were treated at the Los Alamos Meson Physics Facility (LAMPF) with negative pi-mesons (pions) between 1974 and 1981. Of these, 19 patients with metastatic disease were treated in pilot studies. Following the clinical determination of relative biological effectiveness (RBE) of pions, 209 patients were treated in site and dose searching studies beginning in 1977. Advanced but regionally localized cancers that were considered poorly responsive to conventional therapy were selected for treatment. A wide range of treatment fractions (22 to 45) and of total dose (1800 to 4200 cGy at the 80% isodose level) to the prescribed target volumes was explored. A follow-up observation period of between 4.5 and 9 years has been completed. The analysis focuses on 129 patients receiving pion therapy alone. Thirty-six (28%) had persisting local tumor control of which 12 (9%) suffered complications of treatment. The results varied among treatment sites, for example: prostate cancer, 18/21 (86%) locally controlled, 6/21 (29%) complications; head and neck, 8/31 (26%) locally controlled, 1/31 (3%) complications; and pancreas, none controlled and no complications. Analysis of dose-fraction response suggests a steep rising curve of complications beyond the dose level of 3750 cGy minimum, 4700 cGy maximum, in 38 fractions. The tumor control response has a broader and ill-defined curve possibly due to the heterogeneity of tumor types. The RBE for late effects in normal tissues appeared to be higher than that for acute effects although the mixture of tumor types, sites, dose, and fractionation made this estimate highly uncertain. No late secondary neoplastic changes in pion irradiated tissues were seen. It is concluded that pions can locally ablate some advanced cancers, often without significant sequelae, but that the optimum therapeutic range is critical. The Los Alamos data may be of use to ongoing pion studies in Canada and Switzerland.

Elementary Particles↗
PubMed1987

Lymphatic drainage in patients after replantation of extremities.

Lymph drainage was studied by means of lymph scintigraphy in eight patients in whom successful replantation of a totally or subtotally amputated extremity had been performed. Scintigrams were made after subcutaneous injection of technetium-99m in the replanted part of the patient and the contralateral, normal extremity. In all scintigrams, axillary or inguinal lymph node activity is seen, implying drainage of lymph by means of the lymph vessels. Retention of colloid in the replanted part (79 to 94 percent) shows no significant difference with the contralateral, normal side (86 to 94 percent). Unquestionable evidence of regeneration of lymphatics in humans is delivered in the three patients, in whom lymph node activity and normal retention percentages are seen on the scintigrams after total amputation of an extremity followed by replantation without anastomosing of interrupted lymph vessels.

Extremities↗
PubMed1986

Trends in psychotropic prescribing in general practice and general medical patients.

Psychotropic drug prescribing in 1280 medical inpatients between 1973-75 was compared with that in 1200 similar patients during 1982-83. Three benzodiazepines accounted for 64% of prescriptions in 1973-75 and nine benzodiazepines for 82% of prescriptions in 1982-83. Over the decade, use of psychotropic drugs fell from 56% to 38% (P less than 0.001), primarily due to a reduction in patients treated only in hospital (34% vs 16%, P less than 0.001). Before admission, the proportions of patients receiving these drugs were similar (17% vs 18%). During admission, concomitant administration of similar drugs declined from 22% of patients in 1973-75 to 11% in 1982-83 (P less than 0.001), while concurrent prescribing before admission increased from 13 to 19%. The marked fall in psychotropic drug use and in inappropriate concomitant therapy indicates an encouraging trend towards more rational drug use at least in hospital. This was achieved without fiscal control and further rationalization of prescribing habits may be achieved by self-audit within the profession without legislative action.

Adolescent↗
PubMed1986

Endotoxin-induced bovine mastitis: arachidonic acid metabolites in milk and plasma and effect of flunixin meglumine.

Arachidonic acid metabolites (AAM) were measured in milk and plasma during the course of acute endotoxin-induced mastitis in 12 lactating cows. Mastitis was induced by intramammary challenge exposure with 10 micrograms of Escherichia coli (026:B6) endotoxin. Endotoxin was injected into the teat cistern via the teat canal of a single randomly selected rear quarter of each cow. Concentrations of prostaglandin (PG) F2 alpha and thromboxane (Tx) B2 in fat-free unextracted milk and of 15-keto-13,14-dihydro-PGF2 alpha in plasma were measured by radioimmunoassay. Total production of AAM in milk was determined by measuring quarter milk production. The AAM were compared in 6 cows administered flunixin meglumine (1.1 mg/kg of body weight) and in 6 cows administered saline solution. Concentrations of TxB2 in milk were significantly (P less than 0.001) increased during the early course of acute mastitis in endotoxin-treated quarters of cows not administered flunixin meglumine. Peak concentrations of TxB2 in milk occurred at 8 hours after endotoxin inoculation. Flunixin meglumine treatment produced significant (P less than 0.05) reductions in milk TxB2 and plasma 15-keto-13,14-dihydro-PGF2 alpha concentrations. Concentrations of PGF2 alpha in milk and total PGF2 alpha and TxB2 production per quarter per milking were not significantly influenced by endotoxin challenge or by flunixin meglumine treatment.

Animals↗
PubMed1986

Efficacy of flunixin meglumine for the treatment of endotoxin-induced bovine mastitis.

The clinical effect of flunixin meglumine administration was determined in cows with acute mastitis induced by intramammary administration of endotoxin. In 12 lactating cows, 10 micrograms of Escherichia coli 026:B6 endotoxin were administered via a teat cannula into the teat cistern of single randomly selected rear quarters. Cows were challenge exposed as pairs. One cow in each pair was administered parenteral flunixin meglumine (6 cows) and 1 cow per pair was administered saline solution (6 cows). Multiple doses (7) of 1.1 mg of flunixin meglumine/kg of body weight or saline solution were administered at 8-hour intervals beginning 2 hours after endotoxin. Cow and quarter clinical signs as well as milk somatic cell concentrations, bovine serum albumin, electrical conductivity, and milk production were determined before and for 14 days after endotoxin inoculation. Intramammary endotoxin produced signs characteristic of acute coliform mastitis. Quarter and systemic abnormalities occurred and milk production was reduced by approximately 50% at 12 hours after endotoxin. Flunixin meglumine therapy significantly (P less than or equal to 0.05) reduced rectal temperatures and quarter signs of inflammation and improved clinically graded depression when compared with these signs in saline solution-treated controls. Milk production and laboratory indicators of inflammation in milk were not significantly (P greater than 0.05) different for flunixin meglumine vs saline solution controls. The clinical response observed was consistent with the antipyretic, analgesic, and anti-inflammatory properties of flunixin meglumine.

Animals↗