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Biomedical subjects

N Davies

Publications and source records attributed to N Davies.

107 records · Page 6Linked to original sources

Isolation, biochemical characterization, and culture of lung type II cells of the rat.

A method is described for the isolation of rat lung epithelial Type II cells using trypsin digestion of tissue to release cells for subsequent separation by Percoll gradient centrifugation. Both the concentration of trypsin and the age (body weight) of the rat affect the yield from primary digestion and the final number of Type II cells obtained. A lung weighing 1 g from a 200 g rat yields approximately 30 X 10(6) washed Type II cells (approximately 25% of the total estimated lung population). These cells have a plating efficiency of 40-50% after 48 h of culture. The cells have a high alkaline to acid phosphatase ratio (usually greater than 4.0) compared with that of alveolar macrophages (0.1) and accumulate putrescine by an active transport mechanism with an apparent KM between 8 and 14 microM. Together with studies of [3H]thymidine uptake into DNA, which is maximal between 48 and 72 h of culture, these quantitative measurements form a good basis for investigating the interactions between a number of chemical agents and Type II cells in vitro.

Aging↗

The complications of colposuspension.

Fifty patients with stress incontinence treated by a colposuspension procedure were reviewed symptomatically and urodynamically before and after surgery and followed up for 1 to 6 years (mean 4.5). Although 84% were continent post-operatively, only 63% of those previously operated on for incontinence were dry, and only 44% were dry and complication-free in the long term.

Adult↗

Carcinoma associated with augmentation cystoplasty.

Three patients with augmentation ileocystoplasties developed carcinoma at the ileovesical junction 7, 22 and 24 years after surgery. All were originally reconstructed for genitourinary tuberculosis and all had developed huge capacity ileal segments with large residual urines, associated with recurrent urinary tract infection. With the current trend for using small bowel for both augmentation and substitution cystoplasty, balanced voiding must be achieved and maintained, and long-term follow-up is mandatory.

Adenocarcinoma↗

Venereal trichomoniasis: role of men.

It has been suggested that high zinc concentrations found in men may prevent Trichomonas vaginalis from being established in the male reproductive tract. In this investigation T vaginalis was readily killed at concentrations of zinc that occur in the prostatic fluid of healthy men (minimum trichomonacidal concentration (MTC) of 6.4 mmol/l). T vaginalis was also shown to be killed by human prostatic extracts as well as by human seminal fluid, even when the zinc content was much lower than the MTC for T vaginalis. It seems likely, therefore, that there are at least two antitrichomonal mechanisms in the male reproductive tract, one being zinc dependent and the other not relating to zinc content. Tritrichomonas foetus, which causes venereal trichomoniasis in cattle, was unaffected by bovine seminal fluid and was killed by zinc only at concentrations far higher than those found in the prostatic fluid in the bull (MTC 200 mmol/l).

Animals↗

Clinical and haemodynamic effects of diazoxide in primary pulmonary hypertension.

Diazoxide was injected into the pulmonary artery in nine patients with primary pulmonary hypertension. There was no significant change in pulmonary artery pressure, which fell by more than 10 mmHg in only two patients. The pulmonary blood flow increased in all patients as a result of a fall in pulmonary vascular resistance (by 4 to 17 units). Systematic vasuclar resistance also fell as expected in all patients. Oral diazoxide was given to seven patients, two of whom showed sustained clinical improvement while remaining on treatment (400 to 600 mg daily). Five patients were unable to tolerate the drug, because of nausea and sickness (two), peripheral oedema requiring large doses of diuretics (four), diabetes (three), and postural hypotension (one). Hirsutes was troublesome in the two patients remaining on treatment. Diazoxide may be useful in the management of some patients with primary pulmonary hypertension, but its use is limited by the frequency of side effects. Our results suggest that examination of othe potent vasodilators may be worth while.

Administration, Oral↗

Which characteristics of schizophrenia predate psychosis?

Neuropsychological and brain structural abnormalities are present in first onset schizophrenia; the balance of evidence is that in the majority of cases these are developmental in origin. A proportion of first degree relatives also show lateral ventricular enlargement, cortical volume decrease and possibly loss of the normal cerebral asymmetry; these findings suggest that certain families transmit a genetic defect in the control of neurodevelopment. On the contrary, decrement in left hippocampal volume appears to be secondary to perinatal hypoxia. High risk, follow-back and cohort studies all demonstrate that preschizophrenics as a group show deviant development; delayed milestones, lower IQ, solitary play, excessive anxiety, and minor neurological problems are all common. It seems likely, but not proven, that these are a manifestation of underlying neurodevelopmental disorder.

Adolescent↗

Alcohol dehydrogenase: an autoantibody target in patients with alcoholic liver disease.

The link between alcohol consumption and liver disease is not direct and several factors including autoimmunity to hepatocyte components have been implicated. We have previously identified alcohol dehydrogenase (ADH) as an autoantigen in autoimmune liver disease and in a proportion of patients with alcoholic liver disease. The aim of the present study is to investigate the association between the presence of anti-ADH antibodies, alcohol consumption and severity of liver damage in alcoholic patients. The presence of antibodies to human ADH beta2 and horse ADH was investigated in 108 patients with documented history of alcohol consumption and alcohol related liver disease, 86 being active alcohol abusers and 22 on sustained alcohol withdrawal, 39 with non-alcohol related disease and 22 normal subjects. Antibodies to either ADH form were more frequently detected in active alcohol abusers (55/86, 64%) than in patients on sustained alcohol withdrawal longer than 6 months (1/8, 13 %, P < 0.005), HBV infection (2/8, 25 %, P=0.03), non-alcohol related disease (9/29, 23 %, P < 0.0001) and in normal controls (3/22, 14 %, P < 0.0001); were more frequent in patients with cirrhosis than in those with steatosis (26/34, 76 % vs 34/64, 53 %, P=0.02); and were associated with elevated levels of ALT (anti-ADH beta2, P < 0.05), immunoglobulin A (P < 0.05) and gamma-glutamyl transpeptidase (P=0.01). Anti-ADH antibody positive serum samples were able to inhibit the enzymatic activity of ADH. These findings suggest that anti-ADH antibodies may be triggered by alcohol consumption and act as a disease activity marker in alcoholic liver disease.

Adult↗

Acute myocardial infarction: contemporary risk and management in older versus younger patients.

The in-hospital management and risk of death of 101 patients 70 years of age or older with acute myocardial infarction in 1987 (group 1) were compared with management and risk for 106 temporally matched patients less than 70 years old (group 2). In group 1, 49% had histories of previous myocardial infarction, compared to 25% in group 2 (P less than 0.001), and 23% of group 1 presented without cardiac pain, versus 7% of group 2 (P less than 0.001). Among the younger patients, other conventional risk factors were, in contrast, more common (Q wave infarction 84% in group 2 versus 70% in group 1; P less than 0.05) or higher (peak creatine kinase values 2222 iu/L in group 2 versus 1366 iu/L in group 1; P less than 0.001). Prior to infarction, all cardiac drugs were used more frequently in the older group 1 patients, whereas post infarction thrombolysis, beta-blockers and acetylsalicylic acid use were all more common (P less than 0.01 to P less than 0.001) in the younger group 2 patients. Post infarction exercise testing, left ventricular ejection fraction calculations and coronary angiography were all performed less frequently in group 1 (P less than 0.001). The in-hospital mortality was 35% for group 1 versus 7% for group 2 (P less than 0.001). Among all 207 study subjects, multiple logistic regression revealed thrombolysis, absence of cardiac pain, and age 70 years or older to be associated with the greatest relative mortality risk. Increased relative risk to a lesser degree was associated with previous infarction, male sex and post infarction use of antiarrhythmic medication.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗