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Biomedical subjects

A Simpson

Publications and source records attributed to A Simpson.

At least 37 records · Page 2Linked to original sources
PubMed1988

Monoclonal antibodies to human antigens recognise feline myeloid cells.

Immunological techniques have been used to study the expression of a series of cell surface antigens in cat haemopoietic tissues. Forty-two monoclonal antibodies raised against well-defined antigens of human origin were tested by indirect immunofluorescence on feline blood, bone marrow, spleen and thymus. Myeloid cells from all tissues reacted with antibodies to CD9, CD10 and CD18 antigens. No antibodies specific for T or B lymphocytes were found to react with cat lymphoid cells. Osteoclasts, isolated from juvenile bone marrow, were found to express the 23C6 human osteoclast-specific antigen. The potential use of such antibodies in experimental and diagnostic veterinary haematology are discussed.

Animals↗
PubMed1988

Thermode for deep focal cooling.

A cooling thermode is described that can be used to reversibly lesion deep structures with minimal penetration damage. Construction, associated equipment, and use of this thermode are simpler and less expensive, and it can be made smaller in size, than previously described thermodes. The user has a choice of a simple, inexpensive control arrangement that is somewhat more complicated to use, or a more expensive control system that is simpler to use. The diameter of this thermode can be at least as small as 0.3 mm, which is smaller than any previously described thermode. The cooling agent, Co2, is used in such small quantities that toxicity is no problem.

Animals↗
PubMed1988

The treatment of chronic idiopathic thrombocytopenia with anti-D (Rho) immunoglobulin: its effectiveness, safety and mechanism of action.

Twenty-three courses of i.v. anti-D (Rho) immunoglobulin were administered to 13 Rh D-positive patients with chronic idiopathic thrombocytopenia (ITP). Clinically significant responses were seen in a proportion of patients treated with 500-2500 i.u. anti-D, but all those treated with 12,500 i.u. (180 i.u./kg) responded. Patients refractory to other forms of treatment responded well to anti-D, and previous splenectomy did not influence the clinical response. No adverse reactions were observed. The anti-D response was preceded by a lag period of 3-16 days and was maintained for 14-145 days. Platelet-associated IgG was increased after treatment, due to improved survival of immunosensitized platelets or platelet Fc receptor binding of high molecular weight IgG in the therapeutic material. There was no clinical or biochemical evidence of haemolysis. The erythrocyte direct Coombs' test remained positive for 3-45 days, and histological examination of splenic material showed no erythrophagocytosis. We conclude that anti-D (Rho) immunoglobulin is a safe and effective treatment for chronic ITP and that the therapeutic dose is now established in standardized units. The mechanism of action appears to be complex and is probably not due to macrophage Fc receptor blockade with immunosensitized red cells.

Adult↗
PubMed1988

Stereoacuity levels and vision problems in children from 7 to 11 years.

A longitudinal study of stereoacuity levels of 859 children at 7 years, 811 children at 9 years and 796 children at 11 years was conducted using the TNO random dot stereotest. The prevalence of defective stereoscopic vision was found to be between 2.1 and 3.2 per cent. A further 10-16 per cent of children had only moderate stereoacuity levels when compared with their peers. The stereoacuity levels achieved by most of the children improved with age, but the rank order correlations for the stereoacuity levels between ages 7 and 9, and ages 9 and 11, were small. Defective stereopsis and poor stereoacuity levels were clearly associated with manifest strabismus and problems of visual acuity, and if failure to pass the quantitative plates was a cut-off point for screening purposes most of the children with visual problems would have been identified.

Child↗
PubMed1987

Central control of gastric acid secretion by extralateralhypothalamic nuclei.

Whether secretion of gastric acid (GAS) is in response to peripheral and/or central administration of chemical or electrical stimuli can be differentiated by vagotomy. GAS has been shown to be controlled by specific lateral hypothalamic (LHA) neurons. Application of 2-deoxy-D-glucose (2-DG) or insulin to the LHA by microinjection or iontophoresis has experimentally induced GAS. The paraventricular nucleus (PVN) has now been found to also affect GAS. GAS was produced more copiously and more quickly by rostral PVN lesion than by lesion of the ventromedial (VMH) or dorsomedial (DMH) nucleus, and nearly as much by caudal PVN lesion. Microinjection of 2-DG into the LHA induced GAS more potently in animals with rostral PVN lesions than in those with caudal PVN, VMH or DMH lesions, or in intact animals. Results indicate that the PVN may be an additional central site from which GAS is affected.

Animals↗
PubMed1986

Variations in operation rates in New Zealand.

The standardised rates of nine common operations in the seven largest hospital boards in New Zealand varies markedly with the ratio of highest/lowest ranging from 1.2 for cholecystectomy to 2.9 for tonsillectomy. There were also marked variations between New Zealand, Scotland, USA and England and Wales with the ratio of high/low ranging from 1.2 for appendicectomy to 4.5 for haemorrhoidectomy. The New Zealand rates tended to be higher than the English but lower than the USA rates. Several operation rates were correlated with the size of waiting lists but there were no other consistent relationships with any of the other variables studied - hospital board funding, percentage of operations performed in private hospitals, and rates of general practitioners, specialist surgeons, and acute surgical beds in public hospitals per 100,000 population.

Female↗
PubMed1986

The in situ saphenous vein bypass graft: radiologic aspects.

The use of the in situ saphenous vein for bypassing arterial occlusions in the lower extremities appears to have a higher patency rate than other bypass procedures but presents unique technical problems, such as lysing valves and occluding venous tributaries. Forty-four patients undergoing in situ bypasses had preoperative arteriograms. Special attention was paid to the small runoff vessels around the ankle, which are not suitable for reversed bypass procedures but may be adequate for in situ bypasses. Eight patients also had preoperative saphenous venograms, which revealed surgically important abnormalities in six cases. Postoperative arteriograms obtained within 2 weeks in 10 patients and within 2-12 months in 15 patients revealed persistent arteriovenous fistulas in four patients, stenoses in nine, occlusions in five, and progressive disease in the nonbypassed arteries in five patients. Early recognition of these problems led to 11 surgical repairs; nine repairs used the interventional radiologic procedures of balloon angioplasty, transcatheter embolization, and catheter thrombolysis. In this group of 44 patients, five patients died with patent bypasses and three patients required amputation despite functioning bypasses. Only four amputations were attributed to bypass failure. This low figure may be due to the close cooperation of the vascular surgeons and the vascular radiologists in dealing with these complicated cases.

Adult↗
PubMed1985

The value of an erect abdominal radiograph in the diagnosis of intestinal obstruction.

The value of an erect abdominal radiograph in the diagnosis of acute intestinal obstruction has been studied. Four observers independently assessed 100 supine abdominal films and then reassessed them in combination with an erect film. The addition of the erect film did not significantly increase the accuracy of diagnosis of obstruction or help in the correct identification of its level. The presence or absence of gas in the rectum was of no diagnostic value.

Humans↗
PubMed1985

Structural evaluation of anorectic action induced by 1,5-anhydro-D-glucitol.

In previous studies, 1,5-anhydro-D-glucitol (1-DG), an endogenous glucose analog, was found to significantly influence physiological feeding behavior. The relationships between the hydroxyl group positions on the pyranose ring carbons and the anorectic action induced by 1-DG and its analogs are discussed. To investigate the effects of these glucose analogs on ingestive behavior, 24 mumole of test solution was injected into the rat third cerebral ventricle immediately before normal eating time, which starts at the beginning of the dark. After initial transient hyperphagia, 1-DG suppressed feeding during the first 12-hr dark period. It prolonged postprandial intermeal interval beginning shortly after injection, but eating rate was not affected and meal size did not decrease until near the end of the normal feeding period. The incidence of drinking episodes decreased concomitant with feeding suppression. Feeding and drinking suppression were also produced by 1,2-dideoxy-D-glucose, 1,3-dideoxy-D-glucose, and 1,4-dideoxy-D-glucose, although they were less potent than 1-DG. They suppressed feeding by prolonging the postprandial intermeal interval, but did not change meal size or eating rate. The anorectic effects of 1-DG were abolished by removal of the hydroxyl group at carbon 6 and by epimerization at carbons 2, 3, and 4. These findings indicate that feeding suppression induced by 1-DG and its analogs is induced mainly by prolongation of the postprandial intermeal interval, and the presence or absence of a hydroxyl group on each carbon of 1-DG is important for its feeding suppression.

Animals↗
PubMed1984

Vision and eye problems in seven year olds: a report from the Dunedin Multidisciplinary Health and Development Research Unit.

An eye examination, including tests of distance visual acuity, near visual acuity, cover tests, and an examination of pupils, eyes, adnexia, and eye movements, was carried out on 988 Dunedin children within approximately one month of their seventh birthday. Information concerning glasses and patching of one eye was obtained by questionnaire. Eye defects were noted in 9.4% of the children with several having more than one problem. Eye defects noted included 5.1% with unaided distance visual acuity of 6/12 or worse in one or both eyes, 4.4% with near visual acuity of the equivalent of N8 or worse in one or both eyes, 3.9% had manifest strabismus, 2.9% had had occlusion of one eye for amblyopia, and 1.2% had other important eye defects. Glasses had been prescribed for 3.6%.

Amblyopia↗
PubMed1984

The concentration of plasma fibronectin in burns patients treated with fresh frozen plasma or plasma protein fraction.

A group of 10 patients with 30-70% burns were given intravenous infusions during the first 48 h following hospital admission either with fresh frozen plasma (FFP) or human plasma protein fraction ( HPPF ). FFP contained 300-400 mg/dl plasma fibronectin whereas none was detectable in HPPF . Circulating plasma fibronectin levels fell quickly in those patients receiving HPPF and levels remained low for 2-3 weeks. In those receiving FFP, plasma fibronectin remained normal during the 48-h transfusion period but fell subsequently. Fibronectin may be an important determinant in the resistance to shock and infections. Consideration should therefore be given to the use of blood products which contain fibronectin and to the monitoring of plasma levels both during the acute and recovery periods after burn injury.

Adolescent↗
PubMed1984

Conformational changes and loss of opsonic function in frozen or heat-treated plasma fibronectin.

Using human peripheral blood monocytes to assay opsonic protein activity, we have examined the efficiency of various procedures for isolating fibronectin from plasma for experimental or therapeutic use. In addition, we have assessed the protein's opsonic activity after cold storage, and after heat treatment to inactivate hepatitis virus. The purification procedures recovered only 30% of available plasma fibronectin whilst cold storage and heat treatment of the purified protein removed all of its remaining opsonic activity. This was associated with no alteration in overall molecular weight or in subunit size but was accompanied by changes in ultraviolet spectrum, suggesting a conformational change in the protein structure. Initial experiments to protect the purified protein against these changes were unsuccessful and unless further attempts are more encouraging, fresh-frozen plasma may be the only current economic source of opsonically active fibronectin. Since this would waste other valuable proteins required for other purposes, the widespread use of plasma fibronectin outside of clinical trials may be unjustified at this present time.

Chromatography, Affinity↗
PubMed1984

A longitudinal study of enuresis from five to nine years.

The prevalence of primary and secondary enuresis was examined longitudinally in a large sample of New Zealand children at ages 5, 7, and 9 years. While the prevalence of primary enuresis fell over time, secondary enuresis increased in prevalence between 5 and 7 years. There were no sex differences. An examination of some of the developmental and background characteristics of the sample indicated that enuresis was not associated with neurodevelopmental delay or 'psychosocial' factors. However, there were strong, long term associations between secondary enuresis and behavioural deviance. The behavioural results suggested that behaviour problems did not arise as a consequence of enuresis, but rather preceded it.

Child↗
PubMed1983

A preliminary evaluation of the use of an automatic impedance tympanometer in the diagnosis of otitis media with effusion in children: a report from the Dunedin Multidisciplinary Health and Development Research Unit.

Microscopic examination by two trained examiners, conventional impedance tympanometry by a trained audiometrist, automatic impedance tympanometry by a person with minimal training and puretone audiometry by trained audiometrists were compared in 468 ears, studied blind. There was complete examiner agreement in microscopic examination in 465 (99.3%) ears, minor disagreement in three (0.7%) ears. There was a more complex relationship between examination methods, with microscopic evidence of effusion being present in 88.2% of ears showing B tympanograms to conventional tympanometry and in 66.7% of ears to automatic tympanometry. Automatic tympanometry provides a reasonably accurate method of detecting middle ear effusion, but tends to overdiagnose this condition compared to alternate methods.

Acoustic Impedance Tests↗
PubMed1983

Abortion.

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Abortion, Legal↗