Biomedical subjects
Publications and source records attributed to J Tapia.
We performed cerebral biopsy in 4 patients with AIDS and evidence of expanding intracerebral lesions. Three patients had cerebral toxoplasmosis and the fourth had Chagas encephalitis. No patient developed complications. We feel that cerebral biopsy is warranted and safe in patients with AIDS and intracerebral lesions of uncertain origin.
A 68 year old diabetic male was admitted with hyponatremia and developed a "deafferentiation" syndrome. Central pontine myelinolysis was suspected after clinical, EEG and brain CAT scan. The diagnosis was confirmed at necropsy. The pathogenesis, clinical manifestations and treatment of this disorder are discussed.
We report the clinical and immunohistochemical features of six cases of intravascular lymphomatosis. All patients presented with symptoms referable to central nervous system (CNS) involvement. In two patients, the diagnosis was made on brain biopsy specimens. In the remaining four cases, diagnosis was made at autopsy. Three of the four autopsied patients had focal extravascular lymphoma, diffuse large cell type. In all five cases tested, immunohistochemical stains on paraffin-embedded sections confirmed the lymphoid nature of the malignant cells. Stains on frozen sections in one case, and on paraffin-embedded tissue in the other four cases, demonstrated B-lymphocyte lineage. In the remaining case, electron microscopy confirmed the lymphoid nature of the tumor cells. All three cases tested expressed the Hermes 3-defined homing receptor antigen and lacked peanut agglutinin receptors. Our results are consistent with other reports confirming the lymphoid nature of so-called malignant angioendotheliomatosis. Our limited analysis of surface receptor molecules suggests that the expression of the homing receptor for high endothelial venules is not in itself responsible for the unusual intravascular location of these cells.
A case of lateral ponto-medullary infarction was studied pathologically using serial sections of the involved region. The infarct involved 4 mm of the lower pons and 10 mm of the upper medulla. The feeding arteries of most of the infarct were traced back to form one small artery 350 micron in diameter which arose from an artery 2 mm in diameter identified as the posterior inferior cerebellar artery. The latter was occluded by a recent thrombus or embolus which blocked the mouth of the branch to ponto-medullary region.
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Severe bleeding from the lower gastrointestinal tract commonly occurs from mucosal lesions such as angiodysplasia and less often from acute ulcerations. Endoscopic coagulation of such lesions is now feasible. Our purpose was to compare the efficacy and histologic injury of bipolar electrocoagulation and argon laser photocoagulation applied at laparotomy in the canine colon. After right colotomy and heparinization in adult mongrel dogs, bleeding standard ulcers were randomly assigned to treatment or control. The colonic ulcers randomized to each group were not significantly different in size or bleeding rate. Efficacy of treatment was evaluated acutely. Adjacent normal mucosa was treated with the same modality as the ulcer to simulate treatment of a mucosal lesion. The same total exposure time (argon laser photocoagulation) or number of pulses (bipolar electrocoagulation) was used for these paired treatments. Gross and histologic injury were determined after 7 days. Both argon laser photocoagulation and bipolar electrocoagulation were uniformly effective in controlling bleeding from standard colonic ulcers and the incidence of full thickness injury was similar, 33%-48%. The histologic damage seen with normal mucosa treatment was consistently less than with standard ulcers for all treatment groups. The difference is easily explained by the reduction in colonic wall thickness of about 50% with creation of standard ulcers. In our opinion, argon laser photocoagulation and bipolar electrocoagulation are safe enough to be used in clinical trials for control of colonic bleeding from mucosal lesions but not acute colonic ulcers.
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The possible interaction of DDT with the lipids dimyristoyl lecithin (DML), dipalmitoylphosphatidylethanolamine (DPPE) and tripalmitin (TP) was studied. The work was carried out on oriented films and crystalline powders of DDT-lipid mixtures at different molar ratios by X-ray diffraction techniques. The diagrams showed only the patterns of pure DDT and that of the corresponding lipid. It is concluded that new phases were not formed and, therefore, no interactions occurred.
An analysis of infant's deaths caused by heart diseases in Chile during year 1988, was performed through a critical review of 5,598 death's certificates and 4,419 infant death audits. The mortality rates due to congenital cardiac defects were 177 per 100,000 liveborn (LB) and varied between 31.5 and 293.0 for 100,000 LB along the country's 26 health districts. In 69% of death's certificates and 25% of death audits, diagnoses were nonspecific regarding to the type of cardiac malformation, in 15% of deaths diagnostic orientation was incorrect and in 32% a clinical suspicion of congenital heart disease was raised by the primary physician but patients did not reach specialized treatment. One half of deaths occurred at general regional non specialized hospitals and 28% at hospitals of higher complexity. Of these late, 10% occurred after corrective or palliative surgery and 7% in patients considered to be inoperable.
To describe the incidence of mitral valve abnormalities among infants aged 0 to 24 months, their anatomic features, site of lesion, severity and associated heart defects, the records of 3,583 such patients submitted for bi-dimensional ultrasound and pulsed Doppler cardiac studies by presumptive heart disease were analyzed. Mitral valve abnormalities were thus detected in 88 of these cases, and were also documented by clinical examination (n: 88), heart catheterization and angiocardiography (n: 11), surgery (n: 17) and necropsy (n: 2). Seventy five cases had additional heart disease, most commonly aortic stenosis (27%), aortic coarctaction (26%) and ventricular septal defects (43%). Papillary muscle deformities at the subvalvar mitral apparatus were considered to be the most frequent mechanism for congenital mitral stenosis (100%), and annulus dilatation was the most frequent cause of mitral insufficiency (49%). Relative incidences of mitral valve stenosis and insufficiency among the whole studied sample were 0.5% and 1.48% respectively. There was a rough correlation between Doppler transmital gradient or regurgitation jet area and the corresponding mitral valve abnormality. This kind of noninvasively obtained data about mitral architecture and function seems to be a very useful and sensitive guide to define and manage this patients.
A study was done in 322 healthy, well nourished infants, 3 to 18 months old from day care centers of metropolitan Santiago, Chile, that were given BCG immunization in their neonatal period: 304 (94.4%) of them showed BCG scars and were included in a double blind open study, to determine the cutaneous responses to 2 TU and 10 TU tuberculin (PPD). There were no differences in the mean size of cutaneous reactions nor in percent positive responses (greater than or equal to 10 mm), but cutaneous reactions greater than or equal to 15 mm were more frequent in infants tested with PPD 10 TU. In 184 out of 304 infants (60.5%) tuberculin reactions were negative (less than or equal to 10 mm). Eighteen out of 322 infants (5.6%) that didn't show BCG scars were injected with PPD 2 TU: tuberculin reactions sized 6 to 9 mm were recorded in 3/18 of these infants but none of them attained 10 mm. Fifty five infants whose tuberculin reactions were 5 mm or less were retested: a booster effect was likely from the appearance of enhanced dermal response after a second tuberculin test done with the same or higher tuberculin strength than the first one in 12/47 of these infants with BCG scar (25%) and in only 1/8 such subjects without BCG scar.
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