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Biomedical subjects

A Phillips

Publications and source records attributed to A Phillips.

At least 109 records · Page 6Linked to original sources
PubMed1994

Aneurysms of the pulmonary artery. Radiographic manifestations.

We analyzed the radiographic manifestations of aneurysms of the pulmonary artery in a retrospective study of 16 patients. The location, shape, size, and number of these lesions were assessed. Pulmonary artery aneurysms can be fusiform or saccular, central or peripheral, solitary or multiple. Many disease processes can lead to aneurysm formation. Correct diagnosis of these vascular lesions is important for patient management.

Adolescent↗
PubMed1993

A malaria control trial using insecticide-treated bed nets and targeted chemoprophylaxis in a rural area of The Gambia, west Africa. 5. Design and implementation of the trial.

A large-scale malaria intervention programme using insecticide-treated bed nets and chemoprophylaxis administered to children was introduced into a rural area of The Gambia. The operation was carried out using the existing primary health care (PHC) service in the region. Training of the village health workers, sensitization of the communities, and implementation of net impregnation and the drug delivery programme are described. This delivery system resulted in over 90% of nets being treated with insecticide and 80% of children receiving over 90% of their tablets during the rainy season. There was considerable variation in the distribution of permethrin on a bed net and between individual nets, which is likely to facilitate the spread of insecticide resistance in the local mosquito populations. Bed nets made from heavier fabrics tended to absorb more insecticide than those made from lighter materials. Four months after dipping, 89% of the insecticide had been lost from treated nets. This was probably due mainly to women washing their nets, an activity carried out on average once every 2 months during the rainy season. The high number of insecticide-treated bed nets in the study area demonstrated that a malaria control programme operated through a PHC system can be implemented successfully.

Antimalarials↗
PubMed1993

Gestalt relations and object perception: a developmental study.

We investigated whether adults and infants aged 3, 5, and 9 months perceive the unity and boundaries of visible objects in accord with the Gestalt relations of color and texture similarity, good continuation, or good form. Adults and infants were presented with simple but unfamiliar displays in which all three Gestalt relations specified either one object or two objects-perception of the objects was assessed by a verbal rating method in the adults and by a preferential looking method in the infants. The Gestalt relations appeared to influence the adults' perceptions strongly. However, the relations appeared to have no effect on the perceptions of 3-month-old infants and weak effects on the perceptions of 5-month-old and 9-month-old infants. The findings support the suggestion that developmental changes in object perception occur slowly. These changes, and the organizational phenomena to which Gestalt psychology called attention, may depend in part on the child's developing ability to recognize objects of particular kinds.

Adolescent↗
PubMed1993

Cuticular hydrocarbon discrimination/variation among strains of the mosquito, Anopheles (Cellia) stephensi Liston.

Cuticular lipids were removed from adult female Anopheles stephensi Liston and the hydrocarbons present were separated and quantified by gas chromatography. Comparison was made between the hydrocarbons of four An. stephensi strains: Russ, sensitive to DDT and malathion and originally isolated in the former U.S.S.R.; Beech, a DDT-resistant Indian strain with high sensitivity to Plasmodium species; St Mal, a strain from Pakistan shown to be resistant to malathion; and Iraq, a DDT-susceptible strain from Iraq. Discriminant analysis indicated that the four groups were distinct and that, on average, 78% of the population could be separated on the basis of the quantities of some of the cuticular hydrocarbons. The profiles of Beech and Russ or Russ and St Mal could be separated in 98% of the cases. There was reduced segregation between the profiles of St. Mal and Iraq, suggesting greater similarity in the hydrocarbons of these two strains. The usefulness of cuticular hydrocarbon in determining species relationships is discussed.

Animals↗
PubMed1993

The constitutive exocytotic pathway in microvillous atrophy.

Microvillous atrophy is a disorder within the intractable diarrhea of infancy syndrome. The disease is believed to stem from a transport defect that prevents exocytosis of brush border-related material. We investigated this hypothesis by examining the direct constitutive exocytotic pathway using sucrase-isomaltase as a representative protein. We also studied various other brush border and lysosomal marker enzymes. The biosynthesis and localization of selected intestinal epithelial enzymes were studied in small-intestinal mucosal biopsy specimens from a total of nine children with microvillous atrophy by: (a) metabolic labeling in organ culture, (b) radioiodination and immunoprecipitation, (c) indirect immunoperoxidase immunocytochemistry, and (d) immunogold electron microscopy. The results demonstrated that brush border enzymes were synthesized normally and could be located in the apical brush border membrane and on microvillous membrane within microvillous inclusions. Brush border enzymes were not detected in the "secretory granules" that accumulated within the apical cytoplasm of epithelial cells. Lysosomal enzymes were only detected within lysosomal bodies. Thus, the direct constitutive pathway is not involved in microvillous atrophy, and a disturbance of endocytosis or the indirect constitutive pathway is unlikely. Any transport defect in the disease probably involves a different, unidentified exocytotic pathway.

Atrophy↗
PubMed1993

Comparative safety and efficacy of clarithromycin and amoxicillin/clavulanate in the treatment of acute otitis media in children.

Clarithromycin is a new macrolide antibiotic with a wide spectrum of activity that includes the pathogens commonly causing pediatric otitis media. This randomized, investigator-blinded, multicenter trial compared the safety and efficacy of clarithromycin and amoxicillin/clavulanate in the treatment of acute otitis media in patients ages 6 months to 12 years. A total of 338 patients with acute otitis media diagnosed by otoscopy were randomized to receive clarithromycin 7.5 mg/kg twice daily, maximum 500 mg twice daily (n = 161), or amoxicillin/clavulanate 13.3 mg/kg three times daily, maximum 500 mg three times daily (n = 177), for 10 days. Treatment groups were comparable with respect to demographics, severity of infection and number of previous episodes. Efficacy was assessed by clinical examination performed within 48 hours of finishing study medication. A successful clinical response was seen in 90% (121 of 135) of evaluable clarithromycin patients vs. 92% (133 of 145) of evaluable amoxicillin/clavulanate patients (P = 0.681). Clinical failure or relapse (Posttreatment Days 0 to 4) occurred in 10% (14 of 135) of clarithromycin-treated patients vs. 8% (12 of 145) of amoxicillin/clavulanate-treated patients. Gastrointestinal adverse events were the most commonly reported in both groups. Of these events diarrhea was the most frequent, occurring in 12% (19 of 161) of clarithromycin and 32% (57 of 177) of amoxicillin/clavulanate-treated patients (P < 0.001). These results indicate that the efficacy of clarithromycin oral suspension was comparable with amoxicillin/clavulanate oral suspension in the treatment of acute otitis media in children. Clarithromycin was better tolerated than amoxicillin/clavulanate with a lower incidence of gastrointestinal side effects.

Acute Disease↗
PubMed1993

The progression of HIV disease in a haemophilic cohort followed for 12 years.

A cohort of haemophilic patients who seroconverted to HIV-1 between October 1979 and July 1985 has been followed to 1 January 1992. The median age at initial seropositivity was 24 years with a range of 2-77 years. By January 1992, 38/111 (34%) had developed AIDS and 39/111 (35%) had died (four of liver failure including one hepatoma). Using Kaplan-Meier plots, the calculated progression to AIDS at 12 years is 45% (95% CI 31, 58): for age > 25 years 63% (95% CI 45, 82), age < 25 years 32% (95% CI 15, 48) P = 0.0001; CMV positive 68% (95% CI 48, 87) CMV -ve 20% (95% CI 8, 32) P = 0.0009. The 12-year progression rate to CD4 + 0.2 or AIDS is 66% (95% CI 55, 76). 21/34 (63%) of patients who are p24 antigen positive have developed AIDS compared to 17/77 (22%) who are p24 antigen negative (= 0.0001). 19/34 (56%) and 20/77 (23%) of those p24 positive and negative respectively have died (P = 0.007). Before antiviral and prophylactic treatment for asymptomatic patients there were nine AIDS cases in 3.84 years experience with CD4+ < 0.05 (1/0.43 years) and since treatment, 10 AIDS cases in 18.22 years (1/1.8 years). Age, CMV status and p24 remain strongly predictive of disease progression. Treatment appears to reduce the incidence of AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Use of a low pressure liquid chromatography system for haemoglobinopathy screening.

A closed low pressure liquid chromatography system (LPLC) is described which is suitable for haemoglobinopathy screening. The system (Glycomat) was originally developed for the quantitation of the glycated haemoglobin (HbA1). The same biochemical principles have been applied to the separation of haemoglobin A2 (HbA2) and haemoglobin variants. The instrument offers three modes of use including a fast haemoglobin elution, a variant screen and a HbA2 assay for thalassaemia screening. The fast screen isolates all of the common haemoglobin variants except HbE which elutes with HbA. This mode is a more rapid alternative to the Sickledex test. The variant screen produces a wider separation of abnormal variants giving an identification and quantitation for each. The HbA2 assay separates this minor fraction from all other haemoglobins giving an accurate percentage. Abnormal variants are also separated. To validate the HbA2 assay 252 samples were assayed by the cellulose acetate electrophoresis/elution method and LPLC with a correlation of 0.932. The system provides an accurate and sensitive alternative to traditional manual chromatography and electrophoresis methods. The automated sampler allows batches from 1-99 samples to be processed with significant savings in operator time.

Chromatography, Liquid↗
PubMed1993

Anderson's disease: no linkage to the apo B locus.

We describe three patients with Anderson's disease who are members of one family; the father and mother are close relatives and three of seven children show symptoms of the disease. All patients suffered from diarrhea, failure to thrive, and recurrent infections during infancy. Although these symptoms disappeared later in life, biochemical disorders (such as low plasma levels of apolipoproteins A1 and B and cholesterol, resulting in avitaminosis E, plus failure to secrete chylomicrons after a fat meal) persisted. Electron microscopy of enterocytes of one of the patients showed accumulation of lipid vacuoles with no significant aberration of the Golgi apparatus itself. It is possible, therefore, that the disease reflects a defect in chylomicron assembly. We found that low levels of apolipoprotein (apo) B48 were present in the patients' plasma. This suggests that the processing of the B100 message resulting in apo B48 functions normally. The possibility that a mutation in the apo B gene results in an abnormal apo B48 protein is very unlikely since a variable number tandem repeat (VNTR) polymorphism probe mapped to chromosome 2 failed to show correspondence of the parent alleles with the disease. These observations confirm the suggestion that Anderson's disease is not linked to the apo B locus.

Apolipoprotein B-48↗
PubMed1992

The effects of alcohol use on rebleeding and mortality in patients with alcoholic cirrhosis following variceal haemorrhage.

The effect of continued alcohol intake on prognosis in alcoholic cirrhotics who have already bled from varices is controversial. To investigate the effect of alcohol intake on prognosis we studied 189 consecutive alcoholic cirrhotics admitted, for the first time, to the Royal Free Hospital with variceal bleeding. Sixty-six died within 30 days of admission and 23 were excluded from the study for other reasons. Of the 100 remaining 15 remained 'probably abstinent' over long-term follow-up, 29 drank occasionally and 56 continued to misuse/abuse alcohol. The percentage survival probability at 2 years was 66% in the probable abstainers, 68% in the occasional drinkers and 63% in the alcohol abuse/misuse group. There were no significant differences in either mortality or rebleeding rates between the three groups. A rebleeding index (designed to take account of the number of rebleeds per patient and the total length of follow-up) also failed to show any significant difference between the three groups. The Cox proportional hazard model was used to study the effect of the following factors on rebleeding and mortality; age, sex, alcohol use, Pugh's score, acute treatment received for initial variceal bleed and long-term treatment received for prevention of recurrent variceal haemorrhage. Pugh's score was significantly related to risk of death during follow-up (p = 0.0122), but none of the other factors was significantly related to risk of rebleeding or mortality. Using conventional methods to determine alcohol use we were unable to demonstrate significant effects of alcohol intake on rebleeding or mortality in alcoholic cirrhotics who had bled from oesophageal varices.

Alcohol Drinking↗
PubMed1992

Preclinical evaluation of norgestimate, a progestin with minimal androgenic activity.

Norgestimate is a novel progestin with highly selective progestational activity and minimal androgenicity. In rabbits, norgestimate binds to uterine progestin receptors, stimulates the endometrium, and inhibits ovulation. Norgestimate acts directly on target organs, stimulating rabbit endometrium when injected into the uterine cavity and inhibiting luteinizing hormone-releasing hormone-stimulated luteinizing hormone release in dispersed rat pituitary cells in culture. Norgestimate has no estrogenic activity, and like other progestins, it suppresses the action of estrogen. Unlike some other progestins, it is relatively free of androgenic activity. Norgestimate and its 17-deacetylated metabolite demonstrate very poor affinity for androgen receptors compared with levonorgestrel and gestodene and do not exhibit androgenic activity when measured as the stimulation of prostatic growth in immature rats. Norgestimate's lack of affinity for human sex hormone-binding globulin is further evidence of its minimal androgenicity.

Androgens↗
PubMed1992

Detection of vancomycin resistance in Enterococcus species.

Enterococcus faecalis and Enterococcus faecium isolates that are resistant to vancomycin have recently been identified in North America and Europe. Of 155 clinical isolates of enterococci (113 E. faecium and 42 E. faecalis), we found that 98 were resistant, 52 were moderately susceptible, and 5 had intermediate susceptibilities to vancomycin by using broth microdilution susceptibility testing according to the National Committee for Clinical Laboratory Standards (NCCLS) (Approved Standard M7-A2). Using NCCLS disk diffusion methodology (Approved Standard M2-A4), we evaluated the NCCLS supplemental M100-S3 revisions for zone diameter interpretive standards and incubation conditions and found 5.8% minor errors. A total of 234 isolates, which included an additional 79 E. faecium isolates that were moderately susceptible to vancomycin, were used to evaluate the Vitek GPS-TA card (bioMerieux, Inc., Hazelwood, Mo.) and the Pos MIC type 6 panel (MicroScan; Baxter Health Care Corp., West Sacramento, Calif.) for the detection of vancomycin resistance. The Vitek card was 100% specific and 72% sensitive, whereas the MicroScan panel with the Walk/Away system was 98% specific, with a sensitivity of 93% which increased to 99% when readings were performed manually. An agar screen plate method was evaluated with vancomycin concentrations of 6, 8, 10, or 12 micrograms/ml; plates were inoculated so as to obtain a final concentration of 10(5) CFU per spot. This method was found to be 100% sensitive and specific at all concentrations.

Drug Resistance, Microbial↗
PubMed1992

Motivational effect of cholesterol measurement in general practice health checks.

A randomized trial was conducted in five general practices in and around Aylesbury, Buckinghamshire to assess the motivational effect of cholesterol measurement on compliance with advice to reduce dietary fat intake and to stop smoking. The advice was given by practice nurses during health checks for cardiovascular risk factors. A total of 578 patients were recruited to the study and randomized into two groups. Both groups were given the same advice and were followed up after a median of three months, but the intervention group was also given immediate feedback on their cholesterol concentration. Follow up was completed for 88.2% of subjects, and those who were not followed up were assumed not to have changed their behaviour. The mean fall in total cholesterol at follow up was 0.11 mmol l-1 (95% confidence interval 0.03 to 0.18) in the intervention group who were told their cholesterol result and 0.02 mmol l-1 (95% CI -0.06 to 0.10) in the control group who were not. The proportion of smokers who were not smoking at follow up was 10.7% and 10.1% in the two groups, respectively. Patients in the intervention group with an initial total cholesterol level of 6.50 mmol l-1 or greater showed a mean fall of 6.2% in cholesterol level whereas those with an initial cholesterol level of less than 5.20 mmol l-1 experienced a mean increase of 3.6%, but as differences of this magnitude were also seen in the control group they probably reflect regression to the mean rather than an effect of knowledge of cholesterol level.(ABSTRACT TRUNCATED AT 250 WORDS)

Attitude to Health↗
PubMed1992

Effect of dialyser composition and reuse on neutrophil count and elastase alpha-1 proteinase inhibitor complex formation.

To assess the inter-relationship of leucopenia and PMN elastase release we undertook a prospective crossover study of 6 patients dialysed with new and reused cuprophane, cellulose acetate and polysulfone membranes. Serial blood samples were analysed for PMN count, and elastase-alpha 1-proteinase inhibitor complex (E alpha 1PI) concentrations. After 15 min dialysis with new membranes median PMN counts fell by 72.2%, 25.3% and 22.1% with cuprophane, cellulose and polysulfone, respectively. With reuse the decreases were reduced to 6.4%, 8% and 13.6%. All membranes produced a gradual increase of E alpha 1PI. Median E alpha 1PI accumulation rates (ng ml-1 min-1) with new membranes were 175, 169 and 187 for cuprophane, cellulose acetate and polysulfone, respectively. With reuse of cuphrophane and cellulose acetate these rates fell to 99 and 109 (p less than 0.05 and p less than 0.05, respectively), however, with polysulfone it remained unchanged at 180 ng ml-1 min-1. This study highlights differences between two aspects of the neutrophil response to haemodialysis, and demonstrates that extrapolation from individual parameters to conclusions concerning biocompatibility may be inappropriate.

Adult↗