Respiratory distress syndrome in the newborn: Radiological aspects

No Abstract

Inflammatory bowel disease in Cape Town, 1975-1980 Part I. Ulcerative colitis

Previously documented and new patients with ulcerative colitis seen between 1975 and 1980 in the Gastro-intestinal Clinic of Groote Schuur Hospital were studied to establish the local incidence and clinical features of tHis disease. There were 220 patients and the mean follow-up was 7,7 ± 0,4 years. Sixty percent of patients were White, 37% Coloured and 3% Black. The incidence for the Coloured and White population was calculated' to be 1,3 and 2,4/100000 per year during 1970-1974 and 1,6 and 2,1/100000per year during 1975-1980. respectively. In Jews the rates were 8.5 and 10.4/100 000 per year for the two periods. Insufficient data are available to calculate an incidence for the Black population. The disease was limited to less than 15 cm above the anus in 14% of patients, to the rectoSigmoid colon in 45%. and to the rest of the colon in 40%. Although the severity of symptoms was related to the extent of disease, 22% of patients with extensive colitis had mild symptoms, while 15% with disease limited to the rectum had severe symptoms. The clinical features were similar in the White and Coloured population groups. A total colectomy was performed on 20% of patients with extensive colitis; in 2%the diseasewas complicated by colonic-carcinom

Combined assessment (aspiration cytology and mammography) of clinically suspicious breast masses

We examined the safety and utility of the combined assessment of aspiration cytology and mammography in 705 women who had clinically suspicious or malignant palpable breast masses. Histological assessment confirmed 176 benign and 529 malignant lesions. There were no incorrect (false positive) diagnoses made in the 176 benign masses when combined assessment was used (specificity 1,0; predictive value 0,86); in isolation, however, there was a false positive cytological diagnosis ('papillary carcinoma') and 3 false positive mammographic diagnoses. Benign disease (false negative) was incorrectly diagnosed by combined assessment in 4 of the 529 malignant masses (sensitivity 0,99; predictive value 0,98): cytological diagnoses were of fat necrosis (2) and benign cells on cytospin (1) and aspiration biopsy (1); mammographic diagnoses were of benign disease (2) and normality (2). Indeterminate ('atypical', 'suspicious') diagnoses were problematic and frequent (overall 223 (31,6%), malignant masses 137 (25,9%), benign masses 86 (48,9%); cytology 117 (16,6%), mammography 141 (20%). Thus, with the combined assessment of mammography and cytology in clinically suspicious breast masses, a decisive diagnosis was made in about two-thirds of cases allowing the safe commencement of therapy; the balance of patients required core or excision biopsy

Fixed-Parameter Algorithms in Analysis of Heuristics for Extracting Networks in Linear Programs

We consider the problem of extracting a maximum-size reflected network in a linear program. This problem has been studied before and a state-of-the-art SGA heuristic with two variations have been proposed. In this paper we apply a new approach to evaluate the quality of SGA\@. In particular, we solve majority of the instances in the testbed to optimality using a new fixed-parameter algorithm, i.e., an algorithm whose runtime is polynomial in the input size but exponential in terms of an additional parameter associated with the given problem. This analysis allows us to conclude that the the existing SGA heuristic, in fact, produces solutions of a very high quality and often reaches the optimal objective values. However, SGA contain two components which leave some space for improvement: building of a spanning tree and searching for an independent set in a graph. In the hope of obtaining even better heuristic, we tried to replace both of these components with some equivalent algorithms. We tried to use a fixed-parameter algorithm instead of a greedy one for searching of an independent set. But even the exact solution of this subproblem improved the whole heuristic insignificantly. Hence, the crucial part of SGA is building of a spanning tree. We tried three different algorithms, and it appears that the Depth-First search is clearly superior to the other ones in building of the spanning tree for SGA. Thereby, by application of fixed-parameter algorithms, we managed to check that the existing SGA heuristic is of a high quality and selected the component which required an improvement. This allowed us to intensify the research in a proper direction which yielded a superior variation of SGA

Inflammatory bowel disease in Cape Town, 1975-1980 Part n. Crohn's disease

Patients with Crohn's disease seen in the Gastrointestinal Clinic of Groote Schuur Hospital between 1975 and 1980 were studied to establish the incidence and clinical features of this disease. There were 117 patients and the mean (± SEM) follow-up was 6,1 ± 0,5 years. Of these patients 72% were White, 37% Coloured and 1% Black. The incidence for the Coloured and White population groups was calculated to be 0,4 and 0,9/100000 per year during 1970-1974 and 1,3 and 1,2/100000 per year during 1975-1980 respectively. In Jews the rates were 5,0 and 7,2/100000 per year forthe two periods. Insufficient data are available to calculate an incidence for the Black population. The disease involved the ileum in 39%, the colon in 17%and both areas in 44% of patients. At presentation 18% of patients had mild, 37% moderate, and 45% severe disease. The severity of symptoms was not related to the extent of the disease. A peri-anal fistula was present in 24% of patients. There was no difference in clinical features between the different population groups. Surgical resection had been performed in 50% of patients and 29% of these had had two or more resections. The surgical rate in the ileitis group was 63%, in the ileocolitis group 49% and in those with colitis 20%

Primary sclerosing cholangitis associated with inflammatory bowel disease in Cape Town, 1975 -1981

Patients with inflammatory bowel disease and serum akaline phosphatase persistently raised to more than twice the normal level were investigated to assess the frequency of primary sclerosing cholangitis (PSC) in the Gastro-intestinal Clinic from 1975 to 1981. Twelve patients had a persistently raised alkaline phosphatase level of hepatic origin, 9 out of 250 with ulcerative colitis and 3 out of 164 with Crohn's disease. PSC was demonstrated in 8 (3%) of the patients with ulcerative colitis, and carcinoma of the pancreas in the remaining 1. Three of the patients with PSC also had gallstones. The colitis antedated the biliary symptoms and signs in all but 1 patient. There was no correlation between the duration, extent and activity of the colitis and the development and outcome of the liver involvement. Investigations in the 3 patients with Crohn"s disease revealed the presence of PSC in 2 (1,2%) and chronic active hepatitis in the 3rd. Of the 2 with PSC, one had cholelithiasis and has had recurrent episodes of cholangitis. The other has had only mild symptpms

Mimetic butterflies support Wallace's model of sexual dimorphism

Theoretical and empirical observations generally support Darwin's view that sexual dimorphism evolves due to sexual selection on, and deviation in, exaggerated male traits. Wallace presented a radical alternative, which is largely untested, that sexual dimorphism results from naturally selected deviation in protective female coloration. This leads to the prediction that deviation in female rather than male phenotype causes sexual dimorphism. Here I test Wallace's model of sexual dimorphism by tracing the evolutionary history of Batesian mimicry—an example of naturally selected protective coloration—on a molecular phylogeny of Papilio butterflies. I show that sexual dimorphism in Papilio is significantly correlated with both female-limited Batesian mimicry, where females are mimetic and males are non-mimetic, and with the deviation of female wing colour patterns from the ancestral patterns conserved in males. Thus, Wallace's model largely explains sexual dimorphism in Papilio. This finding, along with indirect support from recent studies on birds and lizards, suggests that Wallace's model may be more widely useful in explaining sexual dimorphism. These results also highlight the contribution of naturally selected female traits in driving phenotypic divergence between species, instead of merely facilitating the divergence in male sexual traits as described by Darwin's model