Biomedical subjects
R Rowland
Publications and source records attributed to R Rowland.
Ultrastructure and electron-probe x-ray analysis of the pigment in melanosis duodeni.
A patient with peptic ulceration developed melanosis duodeni, which was studied by light microscopy, histochemistry, electron microscopy and electron-probe x-ray analysis. Our studies show that the pigment in melanosis duodeni resides in the lysosomes of macrophages in the lamina propria. The pigment is not melanin or a melanin-like compound as has been claimed by previous workers. On the basis of electron-probe x-ray analytical findings we have concluded that the pigment is essentially FeS. On the basis of the history of this patient and cases reported in the literature we think that the Fe in this pigment is derived from haemorrhage in the gastrointestinal tract. We also found small amounts of Ca, K, Al, Mg, Si, and Ag. It would appear that Al, Mg and Si were probably derived from the biological milieu and/or other drugs and/or food and/or specimen contamination.
Radiation veno-occlusive liver disease.
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Whipple's disease: a case with circulating immune complexes.
A patient with Whipple's disease was studied for 56 wk from diagnosis, during which time he received continuous antibiotic therapy. Intramucosal bacillary bodies detected by electron microscopy disappeared within 12 wk and a threefold fall in antibody titer to Hemophilus influenza type B bacillus occurred during this period. Circulating immune complexes of IgG class were consistently detected during the first 28 wk of treatment but not subsequently. IgM class immune complexes were detected at a time when mucosal recovery had occurred and when IgG complexes were no longer detectable. A further rise of IgM immune complexes could be induced by enteric challenge with bovine serum albumin in our patient but not in control subjects. The detection of serum immune complexes in Whipple's disease may reflect the entry of foreign antigen through intestinal mucosa. These observations also support the possibility of an underlying defect of antigen exclusion in this disorder, which persists despite apparent mucosal recovery.
Alpha-fetoprotein in the diagnosis of hepatoma.
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Task specific changes in maximal oxygen uptake resulting from arm versus leg training.
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Effects of severe prior exercise on assessment of maximal oxygen uptake.
Five moderately fit males (50.8 ml.kg-1.min-1) performed 14 continuous type VO2 max tests on a motor-driven treadmill. Randomly assigned experimental sessions, consisting of three tests each and separated by 10 (tests 1, 2, 3), 20 (tests 4, 5, 6), 30 (tests 7, 8, 9), or 40 (tests 10, 11, 12) min, were conducted at a consistent hour for each subject every 4th day. Two separately performed tests were also included in the random assignment with the test eliciting the highest VO2 max value designated as the standard reference (SR). VO2 max values for tests 1 through 12 were not significantly different from the SR in spite of elevated pretest blood lactate concentrations ranging from 5 mM to 16 mM. Performance time was reduced for all tests other than tests 1, 4, 7, and 10, reaching the level of statistical significance (P less than 0.05) in tests 2, 3, 5, 6, and 9. It was concluded that valid and reliable assessment of VO2 max is possible even though testing is initiated with subjects in varying stages of exhaustion.
Alpha1-fetoprotein in the diagnosis of hepatoma: statistical and cost benefit aspects.
A rational comparison of different serum concentrations of alpha1-fetoprotein (S-AFP) in the diagnosis of hepatoma must be made. We took data on the sensitivity and specificity of different diagnostic S-AFP concentrations from the literature and evaluated them statistically and by Bayesian analysis. In our patients (hepatoma prevalence 0.028) a sensitive diagnostic concentration (30-50 ng/ml) will misdiagnose hepatoma so often that a positive test will indicate hepatoma in only 10% of cases. A positive test at a specific diagnostic concentration (500 ng/ml) indicates hepatoma in 100% of cases and is preferable in terms of cost benefit. Although the lower concentration will diagnose a larger proportion of patients with hepatoma (74% compared with 59%) the 'costs' of excluding false positives are considerable (A$2545 per extra case with 2.5% of patients suffering significant morbidity). In western societies, where the prevalence of hepatoma is low, a higher, less sensitive but more specific diagnostic S-AFP concentration is appropriate.
Immunoglobulin-bearing cells in giardiasis.
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The diagnosis of giardiasis.
Four methods of diagnosing giardiasis are compared. Examination of smear preparations made from the jeunal biopsy specimen showed positive results in all of the 20 consecutive cases of giardiasis reported. The test was more reliable than examination of histological sections of the jejunal biopsy, wet preparations of jejunal aspirate, or faecal smears.
How many endoscopic biopsy specimens?
In cases in which the endoscopist considers it necessary to attempt to confirm or exclude a diagnosis of carcinoma of the stomach or oesophagus by biopsy and histopathological examination, we find that a minimum of four fragments should be taken. Taking more than eight biopsy specimens appears to do little more than prolong the time taken for a highly skilled team to complete the operation.
Solitary ulcer of the rectum, A report of fiteen cases.
Fifteen cases of solitary ulcer of the rectum are described. The patients complained mainly of rectal bleeding, discomfort and passage per rectum of mucus. The lesion is most commonly situated on the anterior wall of the rectum and can be red and granular, nodular or ulcerating. Peolapse was found in nine cases. The histological lesion is similar to that seen in rectal prolapse. The condition can be mistaken for colitis, adenomatous polyp or carcinoma. Reassurance, defaecation reeducation and dealing with the patients'emotional problems alleviated the condition in some cases. Surgery to remove a prolapsing segment was performed in one case only.
The significance of lowered jejunal disaccharidase levels.
Disaccharidase estimations on 115 consecutive jejunal biopsies are reported. The patients were divided into four groups: 1. Normal jejunal biopsy light microscopy, not milk intolerant, 82 cases. 2. Normal jejunal biopsy light microscopy, milk intolerant, eight cases. 3. Patients with giardiasis, 11 cases. 4. Coeliac disease patients, 14 cases. The lowest disaccharidase levels were found in coeliac disease, with giardiasis cases showing intermediate levels. Poor correlation of lactase levels with milk intolerance was found. Three cases in Group 1 showing lowered lactase levels were given metronidazole and showed remission of clinical symptoms, raising the possibility that they had undiagnosed infections with Giardia lamblia.
The value of endoscopy and biopsy in the diagnosis of gastric carcinoma.
The value of endoscopy and biopsy in the diagnosis of gastric carcinoma has been examined. Out of a total of 550 patients, gastric carcinoma was suspected in 101. Endoscopy and biopsy provided a firm diagnosis in 43 of the 44 cases of gastric carcinoma present, and effectively excluded gastric carcinoma in 48 cases. We recommend endoscopy and biopsy as valuable diagnostic procedures in the investigation of patients suspected of having gastric carcinoma. Used together they can eliminate the necessity for diagnostic laparotomy.
Early gastric carcinoma.
Seven cases of early gastric carcinoma are reported. This condition by definition refers to a carcinoma confined to the mucosa and submucosa only. The definition depends upon the depth of spread and not the surface area covered by tumour or the period over which it is believed to have been present. Each patient had a history indistinguishable from one of benign ulceration. All seven patients had barium meal studies, and in only two was the possibility of malignancy raised. In the other five patients the ulcers demonstrated radiologically were considered benign. Fibreoptic endoscopy was done in six cases; in three the appearances were suspicious of malignancy, and in the remaining three the lesions appeared benign. Biopsy specimens taken at endoscopy contained carcinomatous tissue in all six cases. The patients all had partial gastrectomy, and no recurrence has yet been found. The longest follow-up period is 36 months.
Diarrhoea and colitis associated with antibiotic treatment.
Sixteen cases of colitis developing within twenty-one days of antibiotic therapy are reported. There was a wide range of disease severity. Lincomycin and Clindamycin were implicated in twelve. The colitis was of two pathological patterns pseudomembranous colitis and "non-specific" colitis. There is a relative sparing of the rectum in some cases making the diagnosis more difficult on sigmoidoscopy.
Sickle-cell haemolglobin C disease and sickle-cell beta thalassaemia in white South Africans.
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