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Biomedical subjects

N Wilson

Publications and source records attributed to N Wilson.

At least 145 records · Page 8Linked to original sources
PubMed1992

Successful repair of pulmonary atresia with ventricular septal defect without the use of a conduit: a new surgical option. Report of two cases.

A new technique for the restoration of continuity between the pulmonary artery and the right ventricle in pulmonary atresia with ventricular septal defect without the use of a conduit is described. This was accomplished by anastomosing the inferior margin of the distal pulmonary artery to the apex of a T-shaped infundibular ventriculotomy to form the posterior wall of the reconstructed right ventricular outflow tract. A winged patch of bovine pericardium was then used for the anterior wall to complete reconstruction of the transannular right ventricular outflow tract. This technique was used successfully in two patients.

Anastomosis, Surgical↗
PubMed1992

Dentists' attitudes to cross-infection control.

The wearing of gloves by dentists undertaking clinical procedures has been recommended by many authorities as an essential element of dental surgery cross-infection control. This paper reports an investigation into patterns of glove-wearing by practising dentists, and considers the effect of practice location and practising arrangements on this issue and other aspects of cross-infection control. The results show that these factors, including the type of patient treated, may influence the pattern of glove-wearing by dentists in England and Wales. These findings suggest that groups least likely to follow the recommended infection control procedures should be targeted when assessing dental education requirements.

Attitude of Health Personnel↗
PubMed1992

99mTechnetium-labelled red blood cell scintigraphy as an alternative to angiography in the investigation of gastrointestinal bleeding: clinical experience in a district general hospital.

99mTechnetium-labelled red blood cell scintigraphy (99mTc RBC scintigraphy) was used as the second-line investigation to localise bleeding in 23 patients (11 male, 12 female; mean age 67 years) presenting with active bleeding per rectum. Scintigraphy was available on a 24 h basis. A total of 18 patients had positive scans (78%). Surgery was performed urgently in 11 patients and the site of bleeding, as predicted by scintigraphy, was confirmed in 9 (82%). 99mTc RBC scintigraphy was less useful in patients who were not bleeding actively or who were being investigated for chronic anaemia. This study suggests that 99mTc RBC scintigraphy can play a useful role in the preoperative localisation of unexplained gastrointestinal bleeding in hospitals with nuclear medicine facilities, but confirms it has little place in the management of patients unless they are bleeding actively.

Adult↗
PubMed1991

Risk factors for hepatitis B at a residential institution for intellectually handicapped persons.

We conducted a cross sectional study to evaluate risk factors for hepatitis B (HBV) infection among residents and staff at Braemar Hospital in Nelson. We obtained serum and abstracted medical charts for 114 of the 122 (93%) residents; 129 of 226 (57%) staff members completed questionnaires and provided serum. Seventy (61%) of the residents had serological markers of past HBV infection, including 42 (37%) who were identified as carriers. Residents' risk of being infected increased by 17% for each additional year they had lived in this institution; there were no significant differences in the likelihood of having markers of HBV infection by a person's age at first admission, sex, ethnicity, admission diagnosis, medical history, or various behavioural attributes. Among staff, 20 (16%) showed evidence of past exposure to HBV, but none were identified as being carriers; of these, 5 (25%) reported having received hepatitis B vaccine. Excluding the vaccinated persons who were seropositive, there were no demographic or occupational risk factors that were significantly associated with having serological markers of past HBV exposure. To control further HBV transmission in this setting, all current and future residents, as well as staff members who have direct contact with residents, should be screened for serological markers of HBV and persons identified as being susceptible should be vaccinated.

Adult↗
PubMed1991

Long-term outcome for children with acute renal failure following cardiac surgery.

Acute renal failure requiring dialysis occurred in 34 children (2.9%) following cardiac surgery over a five year period. 17 children (50%) recovered renal function with 11 (32%) long-term survivors. The long-term outcome for the survivors, in terms of renal function, was studied from 1 to 5 years after their episodes of acute renal failure. Three children had significant abnormalities of renal function despite normal urinalysis. Detailed assessment of renal function is advocated for children who survive acute renal failure following cardiac surgery.

Acute Kidney Injury↗
PubMed1991

Big ANF: large-molecular-weight ANF in plasma. I. Gel filtration and affinity chromatography studies.

A large molecular form of immunoreactive atrial natriuretic factor (irANF) was demonstrated in plasma of rabbit and rat on the basis of gel filtration experiments. This big ANF was not retained by octadecylsilane cartridges and cross-reacted with four anti-ANF antisera of different specificities. Gel filtration in acid, but not in 8 M urea, resulted in material with elution characteristics of irANF. Affinity chromatography and gel electrophoresis of big ANF suggested that the material was similar to albumin. However, high concentrations of big ANF were found in analbuminemic rats, with characteristics similar to those seen in rabbit and normal rats (affinity and gel chromatography and gel electrophoresis). We thus conclude that big ANF represents a bound form of ANF in circulation and that the carrier is similar to but not identical with albumin.

Acetates↗
PubMed1991

Big ANF: large-molecular-weight ANF in rabbit plasma. II. Acid dissociation and HPLC of dissociated irANF.

A large-molecular-weight form of atrial natriuretic factor (ANF) was found in rabbit plasma. When extraction of plasma utilizing octadecylsilane cartridges is employed, this big ANF is not retained by the cartridge. When this material is dissociated with acid, immunoreactive ANF (irANF) is released. Of the acids tested, formic and acetic acid (0.05 M) were indicated as the most effective in causing the dissociation. High-performance liquid chromatography analysis of dissociated ANF, confirmed by coelution with synthetic peptides, disclosed the presence of ANF-(99-126) and ANF-(103-126) in a ratio of approximately 2:1. Atriopeptin I was detected in most of the samples analyzed, but atriopeptin II was only detected in one analysis. Despite the wide spectrum of the antiserum used for detection of irANF in the eluent fractions, only immunoreactive peaks coeluting with the four standards were detected. We therefore conclude that big ANF is a bound form of atrial peptides found in normal circulation.

Acetates↗
PubMed1991

Effect of V2 antagonist on clearance of arginine vasopressin by isolated perfused rat kidneys.

Isolated rat kidneys were perfused with Krebs-Henseleit-bovine serum albumin solution at a mean pressure of 99 +/- 2.6 mmHg. After control periods, arginine vasopressin (AVP) was added to the perfusate at a final calculated concentration of 25 pg/ml (2.5 x 10(-11) M). Urine and perfusate samples were collected at 15-min intervals for the following 60 min to measure kidney function and the renal clearance of immunoreactive AVP (irAVP). At 15-30 min after the addition of AVP, total renal clearance of irAVP was 1,623 +/- 190 microliters.min-1.g kidney wt-1. Glomerular filtration accounted for 35 +/- 3.0% of the total clearance, and 65 +/- 10.3% was cleared by peritubular pathways. Of the filtered irAVP, 48 +/- 4.8% was recovered in the urine. To investigate the importance of V2 receptors in the metabolism of AVP, clearance measurements were made in the presence of the V2 antagonist [d(CH2)5,D-Ile2,Ile4,Arg8]AVP (5 x 10(-9) M). Total renal clearance of irAVP was reduced by 48% to 848 +/- 79 microliters.min-1.g-1. This reduction was entirely accounted for by the complete inhibition of peritubular clearance of irAVP. In the presence of the V2 antagonist, irAVP was cleared only by filtration. The proportion of filtered AVP recovered in the urine (53 +/- 8.7%) was not significantly altered by the presence of the V2 antagonist. We conclude that a major component of the renal clearance of AVP depends on receptor-mediated uptake of AVP in the kidney cells.

Animals↗
PubMed1991

Abnormal renal response to twenty-four-hour dehydration and fasting in Nagase analbuminemic rats.

We assessed renal function in fasting adult Nagase analbuminemic rats (NAR). Sodium output in male and female NAR was 68% and 46%, respectively, of the output of age- and sex-matched normal Sprague-Dawley (SD) rats. Potassium excretion was significantly greater in female NAR but there was no difference between male NAR and SD rats. The renal clearances of urea and creatinine were reduced in NAR with corresponding increases in plasma concentrations; however, the urea and creatinine concentrations were not different in plasma samples taken from normally fed and hydrated SD and NAR rats. Exchangeable body sodium and sodium space was significantly larger in normally fed and hydrated NAR than in SD but there were no differences in plasma sodium concentrations or plasma volumes. Although plasma concentrations of albumin in NAR were only about 0.07% of the concentration in SD rats, the renal clearance of albumin in NAR was threefold greater. Kidney weights in NAR were 10 to 16% less than in SD rats but liver weights were 22 to 42% greater. Clearly, renal function was markedly abnormal in Nagase rats during a 24-hour fast.

Animals↗
PubMed1991

[Echocardiography findings in isolated anomalous origin of the right pulmonary artery from the ascending aorta].

Origin of the right pulmonary artery from the ascending aorta is extremely rare. We describe the echocardiographic findings of this lesion in a single case. The absence of an image of the right pulmonary artery in the echocardiographic short axis view at the level of the great arteries, is highly suggestive of this lesion. Differentiation from truncus arteriosus, aorto-pulmonary window and transposition of the great arteries must, and can be made by a comprehensive echocardiographic study.

Aorta↗
PubMed1991

A flow interruption device for measurement of airway resistance.

Unlike conventional methods, the interrupter method for measuring airway resistance is non-invasive and requires minimal patient co-operation. It can therefore be applied in critically ill patients, acute asthmatics, neonates, pre-school children, geriatric patients and unconscious patients. The method is based on transient interruption of airflow at the mouth for a brief period during which alveolar pressure equilibrates with mouth pressure. Measurement of mouth pressure is used to estimate alveolar pressure prior to interruption and the ratio of this to flow prior to interruption gives airway resistance. Using the interrupter method we have developed a portable device for measuring airway resistance which is simple to use and gives a direct instantaneous reading. Measurements of airway resistance obtained using the new device were compared with those obtained using conventional body plethysmograph methods in 43 adult patients. A close correlation was seen (r = 0.86). The two methods appear equally sensitive in detecting changes in airway resistance following bronchodilator therapy. The device has been used successfully in pre-school children unable to co-operate with conventional methods.

Adult↗
PubMed1991

Parasitic and phoretic arthropods of sylvatic and commensal white-footed mice (Peromyscus leucopus) in central Tennessee, with notes on Lyme disease.

Sixteen species of parasitic or phoretic arthropods were collected from 56 white-footed mice, Peromyscus leucopus, live-trapped in central Tennessee from April through November 1987. Arthropod infestation was compared for mice taken from sylvatic (woodland) versus commensal (household) habitats. Three species were recorded from hosts in both habitats: the sucking louse Hoplopleura hesperomydis, the flea Epitedia wenmanni, and the laelapid mite Androlaelaps casalis. Twelve of the 13 remaining arthropod species were taken only from mice trapped in woodland whereas the phoretic glycyphagid mite Glycyphagus hypudaei was collected only from commensal mice. Arthropod faunas on commensal hosts clearly were impoverished. The 12 additional arthropod species recorded from the woodland mice consisted of 1 nidicolous beetle, Leptinus orientamericanus; 1 bot, Cuterebra fontinella; 3 fleas, Ctenophthalmus pseudagyrtes, Orchopeas leucopus and Peromyscopsylla scotti; 1 tick, Dermacentor variabilis; 2 mesostigmatid mites, Androlaelaps fahrenholzi and Ornithonyssus bacoti; 3 chiggers, Comatacarus americanus, Euschoengastia peromysci, and Leptotrombidium peromysci; and 1 undescribed pygmephorid mite of the genus Pygmephorus. Two nymphal and 100 larval D. variabilis were examined for spirochetes and found to be uninfected.

Animals↗
PubMed1990

The evolution of antihypertensive therapy.

The goal of antihypertensive therapy has changed dramatically over the past 40 years. What was once a treatment for a life-threatening disease has gradually evolved to become just one of the many ways of modifying a symptomless risk factor. The development of safer drugs throughout the 1970s resulted in treatment being offered at successively lower levels of blood pressure elevation, and consequently to an ever increasing proportion of the population. Based on new evidence from clinical trials, however, recent policy guidelines for the treatment of hypertension--especially mild hypertension--have become more conservative. Yet, there are a number of reasons for doubting that this policy reversal will be transmitted into actual clinical practice, unless major changes are made to the arrangement of structural interests--professional, industrial and third-party funders--which currently support and maintain antihypertensive therapy on a mass scale. Meanwhile, 'control' of blood pressure, 'quality of life', and 'compliance' with therapy have become ends in themselves, often to the exclusion of much-needed discussion on the real therapeutic goal of antihypertensive medication, i.e., the prevention of cardiovascular and cerebrovascular morbidity and mortality and the question of whether drugs are always the best way to achieve this.

Antihypertensive Agents↗