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Biomedical subjects

P Lewis

Publications and source records attributed to P Lewis.

At least 145 records · Page 8Linked to original sources

Closure of loop ileostomy after restorative proctocolectomy.

The outcome of loop ileostomy closure was evaluated in 40 patients who had previously undergone restorative proctocolectomy. A standard operative technique was used which incorporated a circumstomal incision, non-resectional reconstruction and primary skin closure. Thirty-six patients (90%) enjoyed an uncomplicated recovery. One patient (3%) developed a superficial wound infection. Enterocutaneous fistula was not encountered. Small bowel obstruction occurred in three patients (8%) two of whom required a further laparotomy, but subsequently made an uncomplicated recovery. No incisional hernias were identified at follow-up. We conclude that loop ileostomy closure can be achieved with a low morbidity which should not preclude the use of this stoma in restorative proctocolectomy.

Adolescent↗

Prognosis after surgery for colonic Crohn's disease.

The long-term prognosis including operation rates, the incidences of recurrent disease, morbidity and mortality and current status has been analysed in a group of 360 patients with Crohn's colitis grouped according to the primary site of macroscopic disease at diagnosis. The group has been followed from diagnosis for a mean period of 14.9 years. The overall operation rate was 76 per cent. Prolonged spontaneous or drug induced remission occurred at all sites: right-sided disease (11 per cent), extensive colonic disease (21 per cent) and left-sided disease (38 per cent). The cumulative reoperation rates at 5 and 10 years after right hemicolectomy were 26 and 46 per cent, after colectomy and ileorectal anastomosis 46 and 60 per cent, and after panproctocolectomy 10 and 21 per cent, respectively. There was a twofold excess mortality rate from related Crohn's disease deaths during the period of review, but the mortality rate has fallen with time. There have only been 11 related deaths in the last decade, of which eight were probably unavoidable. The current status of most patients is good, although treatment has included a permanent stoma in less than half (41 per cent) the patients still under review. Currently all but 14 patients are well and symptom-free and only 16 are receiving specific medical treatment. Until the aetiology of Crohn's colitis is understood, if medical treatment has failed to resolve symptoms, appropriate surgical treatment in experienced hands is an effective way of restoring patients with chronic persistent symptoms to good health.

Adolescent↗

Nifedipine in patients with peripheral vascular disease.

The calcium antagonist nifedipine has been studied in a group of patients with intermittent claudication. In a long-term double blind, placebo controlled trial in 27 patients there was no effect on exercise tolerance as measured by pedal ergometry and only a limited improvement in symptom score on double dose nifedipine. Common femoral artery volumetric blood flow (measured by duplex ultrasound) was unaffected. The acute effects on blood flow were also studied, with a mean increase of 23% in common femoral artery blood flow 30 min after sublingual nifedipine. The administration of nifedipine to patients with peripheral vascular disease will not adversely affect claudication symptoms, and may result in an acute improvement in lower limb blood flow. Nifedipine is a suitable antihypertensive in patients who suffer from intermittent claudication.

Administration, Sublingual↗

Speech recognition measures with noise suppression hearing aids using a single-subject experimental design.

Research aimed at quantifying the benefits a hearing aid user might expect from noise suppression hearing aids purported to improve hearing in the presence of background noise have yielded widely varying results. We suggest this may in part be due to the inappropriate use of experimental approaches based on group design and inferential statistical analysis. Included in this paper is our rationale for employing a single-subject experimental design to investigate subject performance with two commercially available hearing-aid noise suppression systems. Preliminary results with two subjects indicate that both the Siemens Automatic Signal Processing (ASP) and Zeta Noise Blocker (ZNB) noise suppression systems markedly improve listener scores on the low predictability sentence material of the SPIN Test. We conclude these two noise suppression systems may improve performance as the listening situation becomes contextually more difficult, and that single-subject experimental designs could be a valuable addition to applied behavioral research with hearing aids.

Evaluation Studies as Topic↗

Relationship of cataract to radiation sensitivity.

Considerable exposure to radiation always causes posterior subcapsular cataract (PSC). This investigation was conducted to ascertain whether cellular hypersensitivity to radiation may be identified as a possible cause of cataract in persons exposed to low levels of radiation. Patients were studied in whom PSC had followed probable exposure to low levels of radiation or in whom PSC had developed before the age of 60 without known exposure. The patients with cataract were compared with age and sex matched controls without cataract. Radiation sensitivity was estimated by measuring clonal growth of skin fibroblasts and peripheral blood lymphocytes after exposure to graded doses of radiation and by measuring postirradiation reconstruction of separated nuclear material from lymphocytes. The results show variations in the level of radiation sensitivity between the patients, without significant differences from the controls. It is concluded that radiation hypersensitivity, as tested by the methods used in this study, is not normally associated with the development of posterior subcapsular cataract.

Cataract↗

The metabolic effects of fatal cyanide poisoning.

Metabolic and toxicological data were obtained during the first 24 hours following severe and eventually fatal cyanide poisoning. Initial blood cyanide concentrations were 804 mumol/l but fell rapidly over 24 hours following cobalt edetate therapy to 15 mumol/l. However, plasma thiocyanate concentrations rose over 24 hours (147-267 mumol/l) suggesting continued tissue detoxification. The major metabolic abnormality was lactic acidosis (initial pH 7.21, blood lactate 17.5 mmol/l) which corrected over 12 hours. Despite high circulating insulin concentrations the responses of blood glucose, plasma non-esterified fatty acid, blood glycerol and 3-hydroxybutyrate suggested marked insulin resistance.

Acidosis, Lactic↗

Respiratory health of brickworkers in Cape Town, South Africa. Background, aims and dust exposure determinations.

The respiratory health and work environment of 575 brickworkers in five brickworks in Cape Town, South Africa, were investigated by means of a questionnaire, a physical examination, pulmonary function testing, chest radiography, and dust measurements. This study presents the background, aims, and methods of the determining dust exposure assignments. The mean concentrations of respirable dust and total dust were 2.22 and 15.16 mg/m3, respectively, with a mean free-silica percentage of 2.1%. Subjective and objective, as well as categorical and continuous, dust indicators were constructed for subsequent analyses, together with findings from the health survey, which are reported elsewhere.

Air Pollutants, Occupational↗

Mortality in Crohn's disease--a clinical analysis.

We have examined the causes of death and the changing pattern of mortality over time among 769 patients with Crohn's disease under long-term review between 1944 and 1984. One hundred and fifty-six patients have died. The cause of death could not be classified in five. The deaths were divided into those related directly to Crohn's disease and unrelated deaths from incidental causes. The cause and age at death among 59 unrelated deaths was similar to that expected in the general population. The common causes of related deaths were sepsis, digestive tract cancer, pulmonary embolus and metabolic disorders. There were 30 deaths after surgery, usually from sepsis after emergency surgical treatment. There have been fewer deaths in recent years and the cause of death has altered. Sepsis and electrolyte imbalance have declined in importance and cancer of the digestive tract is now the most common cause of related death. Occasional death from sepsis occurs in elderly patients. Elective rather than emergency surgical treatment and the routine use of antimicrobial prophylaxis before surgery has probably reduced mortality. With the exception of cancer of the digestive tract the appropriate medical and surgical treatment of patients with Crohn's disease can eliminate excess mortality previously associated with the disorder.

Adolescent↗

Analysis of 1071 gift procedures--the case for a flexible approach to treatment.

An analysis of the outcome of first gamete intrafallopian transfers for 1071 women indicates that for those aged 40 years or more all the oocytes had to be transferred to obtain a 19.2% pregnancy rate. In this age-group pregnancy rate and multiple pregnancy rate were significantly lower than those for younger women. Success rate, but not multiple pregnancy rate, was significantly higher in the group of women from whom 11 or more oocytes were recovered and transferred after ovulation induction than when only 1-4 oocytes were recovered and transferred. The findings suggest that the number of oocytes transferred should depend on clinical circumstances.

Abortion, Spontaneous↗

A multicentre open clinical trial of teicoplanin in infections caused by gram-positive bacteria.

A multicentre open trial of teicoplanin in 81 centres in nine European countries included 1431 cases: 531 female, 900 male; mean age 49.4 years, range 1-93 years. These were hospitalized patients most of whom had infections caused by Staphylococcus aureus (816 isolates). Of a total of 1427 Gram-positive pathogens 280 (19.6%) were methicillin resistant. There were 536 skin and soft tissue infections, 263 septicaemias, 135 lower respiratory tract infections, 179 joint and bone infections and 83 endocarditides. More than a third of the infections were severe. Complicating medical factors were present in 69% of cases, including malignant disease in 14% and diabetes mellitus in 11%. Mean teicoplanin dose was 289 mg/day; mean duration of treatment was 14 days. A total of 471 patients received a high dose regimen, 400 mg teicoplanin daily for at least five days. Monotherapy with teicoplanin was used in 1037 cases and combination with other antibiotics in 394. Overall 91.7% of the 1333 evaluable cases were clinical cured or improved. The MIC of teicoplanin was less than or equal to 1 mg/l for 90% of Gram-positive isolates. Adverse events were reported in 189 cases (13.2%). The most common drug-related event was an allergic type skin reaction which occurred in 35 cases (2.4%). Transient hepatic dysfunction was reported in 28 patients (2.0%).

Adolescent↗

Ranitidine--bolus or infusion prophylaxis for stress ulcer.

Stress ulcer is a dangerous complication for the critically ill patient. Prophylaxis with antacids can undoubtedly reduce this risk, if gastric pH is maintained above 3.5. Histamine receptor antagonists may achieve this more conveniently. We have studied the effects of ranitidine, given either as 50-mg boluses every 6 h or as one of two infusion regimes (125 or 250 micrograms/kg.h), in controlling pH in critically ill patients on a ventilator. The percentage of samples with a pH less than 4 fell in all groups during therapy; while there was no significant difference between groups, pH control was achieved more rapidly in the bolus group. Infusion therapy with ranitidine is an attractive concept but a loading dose must be used. The presence of occult blood in the gastric juice did not correlate with pH and was not affected by ranitidine therapy.

Adolescent↗