Search PubMed⌕ Search

Biomedical subjects

M Robinson

Publications and source records attributed to M Robinson.

At least 307 records · Page 17Linked to original sources
PubMed1990

The role of the contralateral limb in below-knee amputee gait.

Very little quantitative biomechanical research has been carried out evaluating issues relevant to prosthetic management. The literature available suggests that amputees may demonstrate an asymmetrical gait pattern. Furthermore, studies suggest that the forces occurring during amputee gait may be unequally distributed between the contralateral and prosthetic lower limbs. This study investigates the role of the contralateral limb in amputee gait by determining lower limb joint reaction forces and symmetry of motion in an amputee and non-amputee population. Seven adult below-knee amputees and four non-amputees participated in the study. Testing involved collection of kinematic coordinate data employing a WATSMART video system and ground reaction force data using a Kistler force plate. The degree of lower limb symmetry was determined using bilateral angle-angle diagrams and a chain encoding technique. Ankle, knee and hip joint reaction forces were estimated in order to evaluate the forces acting across the joints of the amputee's contralateral limb. The amputees demonstrated a lesser degree of lower limb symmetry than the non-amputees. This asymmetrical movement was attributed to the inherent variability of the actions of the prosthetic lower limb. The forces acting across the joints of the contralateral limb were not significantly higher than that of the non-amputee. This suggests that, providing the adult amputee has a good prosthetic fit, there will not be increased forces across the joints of the contralateral limb and consequently no predisposition for the long-term wearer to develop premature degenerative arthritis.

Adult↗
PubMed1989

Differing hepatotoxicity and lethality after subacute trichloroethylene exposure in aqueous or corn oil gavage vehicles in B6C3F1 mice.

Subacute toxicity of trichloroethylene (TCE) was evaluated in male and female B6C3F1 mice using corn oil or aqueous gavage vehicles. Mice received oral doses of TCE five times a week for 4 weeks at 600, 1200 and 2400 mg/kg/day for males and 450, 900 and 1800 mg/kg/day for females. Vehicle control mice were dosed with either corn oil or a 20% aqueous solution of Emulphor. A dose-related increase in lethality occurred in male and female mice receiving TCE in Emulphor but not corn oil during the first week of treatment. Lethality was consistent with central nervous system depressant effects of TCE. After 4 weeks of exposure, body weights were not altered by TCE but liver/body weight ratios were uniformly increased by TCE administered in either vehicle in both sexes. Only male mice treated with TCE in corn oil, however, sustained elevations in serum enzyme levels, accompanied by liver histopathology. TCE in corn oil produced inflammation-associated focal necrosis in 30-40% of the male mice, with increasing severity from low to high dose. Lipid accumulation, as indicated by Oil-Red O staining, was most prevalent in male mice treated with TCE in corn oil but also occurred to a lesser degree in animals receiving either gavage vehicle alone. This study indicates that the type of oral gavage vehicle is an important factor in determining the nature of TCE toxicity.

Administration, Oral↗
PubMed1989

Carcinogenic activity associated with halogenated acetones and acroleins in the mouse skin assay.

Several chlorinated acetones have been identified in drinking water and these, as well as a number of chlorinated acroleins, are produced by chlorination of humic acid solutions. Many of these chlorinated compounds and the brominated acrolein analog were positive in the Ames Assay in the laboratory. To determine if carcinogenic activity was associated with these chemicals the following acetone derivatives: monochloro (MCA); 1,1-dichloro (1,1-DCA), 1,3-dichloro (1,3-DCA), 1,1,1-trichloro (1,1,1-TCA), 1,1,3-trichloro (1,1,3-TCA), and substituted acroleins: 2-chloro (CAC), 3,3-dichloro (DCAC), 2,3,3-trichloro (TCAC) and 2-bromo (BAC), were applied topically to SENCAR mice (25, 30, or 40/group) at the following dose levels: 50 mg/kg (MCA and 1,1,3-TCA); 50, 75 and 100 mg/kg (1,3-DCA); 100, 200 and 400 mg/kg (CAC, DCAC, and TCAC); 200 and 300 mg/kg (BAC); and 400, 600, and 800 mg/kg (1,1-DCA, and 1,1,1-TCA). Doses were applied six times over a 2-week period in 0.2 ml ethanol per application. 1,3-DCA was also tested with single doses of 37.5, 75, 150 and 300 mg/kg in 0.2 ml ethanol. Control animals received 0.2 ml ethanol per application as a single dose or multiple doses to match corresponding studies. Two weeks after the final dose, 1.0 microgram TPA in 0.2 ml acetone was applied three times weekly for 20 weeks. After 24 weeks the percentage of animals with tumors for dose groups above were: MCA (8); 1,1,3-TCA (10); 1,3-DCA, multiple doses (48, 45, 32); CAC (30, 28, 38); DCAC (3, 0, 0); TCAC (10, 5, 0); BAC (54, 43); 1,1-DCA (0, 5, 0); 1,1,1-TCA (10, 5, 0); 1,3-DCA, single doses (47, 47, 63, 20); controls (12--Table 3, 9--Table 4 average). These data show that 1,3-DCA, CAC and BAC, when applied topically, initiate tumors in the mouse skin. These chemicals administered orally in a 2% emulphor solution, at doses described in Table 3, did not initiate tumors in the mouse skin.

Acetone↗
PubMed1989

Immunological relationships during primary infection with Heligmosomoides polygyrus (Nematospiroides dubius): dose-dependent expulsion of adult worms.

The survival of Heligmosomoides polygyrus was monitored during primary infections in female C57Bl10, NIH and BALB/c mice at low and high intensities of infection. Survivorship curves were fitted for each data set and analysed. C57Bl10 mice, given either low or high intensities of infection, harboured parasites for 28-37 weeks, heavier infections surviving marginally but significantly longer. Essentially the survivorship curves of H. polygyrus in C57Bl10 mice could be accounted for by senility, the increased probability of worms with a longer life-span occurring at high infection intensities and, possibly, by a contribution from host-protective immune mechanisms in the terminal stages of infection. The pattern of survivorship was different in NIH and BALB/c mice. NIH mice showed weak but significant density-dependent suppression of parasite loss and infections in this strain did not exceed 27.5 weeks in duration. Primary infections in BALB/c mice were briefer still and showed marked dependence on parasite density. Thus low-level infections lasted 10-15 weeks whereas heavier infections survived for 21-34 weeks. The data suggested that both strains developed host-protective responses to adult H. polygyrus and that parasite survival was curtailed earlier than would be expected if senility alone was involved. The hybrid strains (C57Bl10 x NIH)F1 and (B10G x NIH)F1 both expelled H. polygyrus in a dose-dependent manner, worm loss commencing within 10 weeks of infection. In some experiments worm loss was clearly evident by weeks 4 and 6. These hybrid strains showed gene complementation in that adult worms were cleared considerably earlier than in parental strains.

Animals↗
PubMed1989

Immunological relationships during primary infection with Heligmosomoides polygyrus (Nematospiroides dubius): expulsion of adult worms from fast responder syngeneic and hybrid strains of mice.

The time-course of low and high intensity primary infections with Heligmosomoides polygyrus was monitored in SJL and SWR mice, both of which usually expel worms within 7 weeks of larval administration. Worm expulsion in these strains was not dependent on the intensity of infection, with low and high intensity worm burdens being lost within the same period of time. The ability to expel worms rapidly was inherited in a dominant manner in F1 offspring of SJL or SWR mice mated with C57Bl10 mice; the latter being a strain in which no loss of worms was evident within 10 weeks of infection. However, neither (SJL x C57Bl10)F1 nor (SWR x C57Bl10)F1 mice expelled worms as rapidly as the parental SJL and SWR strains. (SWR x B10G)F1 [H-2q] mice eliminated worms faster than (SWR x C57Bl10)F1 [H-2bq], suggesting that the b haplotype had a moderating influence on the expulsion process. In fact (SWR x B10G)F1 mice showed a significant reduction in worm burdens by week 4 but by weeks 6-8 the rate of worm loss had slowed considerably. In contrast, SJL and SWR mice, whilst initiating rejection slightly later, (after week 4) expelled all worms within the following 2 weeks. Thus two distinct patterns of response were observed among the fast responder strains as exemplified by SWR and SJL mice on the one hand and (SWR x B10G)F1 on the other. Our results support the hypothesis that the course of a primary infection with H. polygyrus is influenced by multiple host gene loci, some of which are encoded within the MHC. SJL and SWR mice probably have similar if not identical gene combinations at loci which determine a fast responder phenotype, distinguishing them from the other mouse strains which have been studied.

Animals↗
PubMed1989

A perspex grid for localization of non-palpable mammographic lesions in breast biopsies.

The examination of excised, non-palpable mammographic lesions in breast biopsies is a recognized problem for the pathologist. There may be difficulties in identifying the lesion macroscopically and in subsequent sampling. This paper describes a simple method for resolving these problems. The breast biopsy is attached to a perspex grid and then radiographed. Use of the grid co-ordinates assists appropriate sampling of the specimen. Advantages over previously described methods are discussed.

Biopsy↗
PubMed1989

Hypoglycaemic brittle diabetes successfully managed by social worker intervention.

The case is presented of a 39-year-old Type 1 diabetic patient of 22 years duration with recurrent hypoglycaemic comas. He was of unusual personality and had bizarre ideas on self-regulation of his diabetes, resulting in wide variations of insulin dosage. In one 12-month period he had 88 separate admissions to an emergency department with severe hypoglycaemic coma requiring intravenous glucose administration. The cycle of admissions was eventually broken by the intervention of a social worker, who provided structured non-medical support. The patient's diabetic misconceptions remained, but he appeared to gain sufficient insight to prevent recurrent hypoglycaemia.

Adult↗
PubMed1989

Plasma fibronectin in Crohn's disease.

The hypothesis that abnormal fibronectin metabolism in Crohn's disease could be an important mechanism leading to stricture formation or postoperative infection was tested in three related studies. (1) Lower concentrations of plasma fibronectin (p less than 0.05) were found in 20 patients with small and large bowel Crohn's disease (mean 0.24 g/l) compared with 13 patients with more limited disease confined to only small or only large bowel (mean 0.27 g/l) or 20 healthy controls (mean 0.29 g/l). (2) In 25 patients followed for 10 days after operation for Crohn's disease, there was a significant fall in fibronectin concentrations of 43% (p less than 0.01, Wilcoxon's rank-sum test). This fall was maximal on the second postoperative day and was more marked in patients undergoing more major operative procedures. (3) The predictive value of plasma fibronectin for subsequent stricture formation or progression was studied for one year; during which 10 patients developed strictures requiring operative treatment. Higher plasma fibronectin concentrations were related to stricture formation, although there was not a complete, predictive relationship. In this study we found that plasma fibronectin concentrations were low in patients with extensive or severe Crohn's disease, fall after operation and may be related to the risk of stricture formation. This relationship is unlikely to be of clinical value, although it shows the potential significance of fibronectin in the pathogenesis of strictures.

Adult↗
PubMed1989

Blood cell rheology in acute cerebral infarction.

Recently it has been hypothesized that leukocyte rheology could be a relevant variable of the microcirculation during cerebral ischemia. However, relatively few studies have been carried out on the rheologic behavior of leukocytes in vascular diseases. This study aimed at quantifying the filterability through Nuclepore filters (mean pore diameter 5 microns) of both leukocyte subpopulations and red blood cells in patients with acute stroke compared with age-matched healthy controls. Leukocytes were separated by density into polymorphonuclear and mononuclear cells. Filterability of the red blood cells and polymorphonuclear and mononuclear subpopulations in buffer was measured using a constant-flow and low-positive pressure system. We used one-way analysis of variance, signed rank sum, and simple and multiple regression tests for statistical analysis. Twenty consecutive male patients with acute ischemic infarction were compared with 20 age-matched healthy subjects. Mononuclear cell filterability was impaired in acute stroke (7.26 +/- 2.00) compared with the controls (5.55 +/- 1.23) (p less than 0.01). Polymorphonuclear cell filterability was less, but still significantly (p less than 0.05), impaired in acute infarction (5.75 +/- 0.87 vs. 4.19 +/- 0.43). The results show that leukocyte and, especially, mononuclear cell filterability is impaired in acute infarction, while no differences exist in red blood cell filterability.

Acute Disease↗
PubMed1989

Catheterisation for nephrectomy?

A retrospective review of 64 nephrectomies performed in 1985 and 1986 revealed an incidence of postoperative catheterisation of 48%, compared with 20% in an age and sex matched group of patients undergoing cholecystectomy (P less than 0.01). In the 27 male patients over 40 years of age undergoing nephrectomy, there was a 75% incidence of postoperative catheterisation. A figure of 47% was found for the comparable female group. We recommend that routine peroperative catheterisation should be performed in patients over 40 years of age undergoing a nephrectomy.

Adult↗
PubMed1989

Issues in the nursing management of patients with water intoxication.

The syndrome of water intoxication, experienced by a small percentage of hospitalized chronically mentally ill patients, is a two-stage process, usually beginning with polydipsia. In some patients the physiological ability to excrete excess free water is lost, and polydipsia progresses to hypervolemia and hyponatremia. The hyponatremia responds to fluid restriction. Nevertheless, nursing intervention associated with limiting a patient's fluids is complex, including psychodynamic, social, and behavioral factors. Because of the complexity of nursing care, and because of the unanswered questions about etiology and treatment of water intoxication, the area is fertile for nursing research.

Humans↗