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Biomedical subjects

J A Barcat

Publications and source records attributed to J A Barcat.

At least 19 recordsLinked to original sources

[Hodgkin's disease of mediastino-pulmonary onset associated with tuberculosis of unusual presentation].

A 36 year-old non-smoker woman was admitted because of a rapidly growing mass at the left hilum. Fiberoptic bronchoscopy did not show any abnormality. A percutaneous Rotex needle biopsy and a cutting needle biopsy showed atypical cells suggestive of an anaplastic tumor, possibly a sarcoma. A thoracotomy biopsy demonstrated nodal and pulmonary involvement by Hodgkin lymphoma (nodular-sclerosis form) and pulmonary TBC (granulomas with caseum and acid fast bacilli (AFB)). The patient started treatment with isoniazid, rifampin and pirazynamide and then she received chemotherapy and radiotherapy. One year later her chest and abdominal CT were normal. Twelve months after that she developed severe dyspnea with a chest x-ray film with interstitial infiltrates and a mass at the left-hilum. She worsened quickly and died. At autopsy no evidence of active TBC was found and extensive involvement by lymphoma was demonstrated. The diagnosis in this patient was not obtained by clinical-radiological signs or by non-invasive tests but only by surgical biopsy. The association between neoplasm and TBC is well known, but now is very rare. In Argentina TBC prevalence in lymphomas is 1.2% (higher than control population). TBC diagnosis can occasionally be difficult. In most of undiagnosed patients TBC is the main contributor to death. In this patient the mediastinopulmonary mass was adequately diagnosed only after an open biopsy which showed it to be caused by two coexistent diseases, previously unsuspected and both amenable of effective treatment. This case shows the heterogeneity of TBC presentation and stresses the need to consider it in each non-defined mediastino-pulmonary lesion in countries where TBC is highly prevalent.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Depressed plasma erythropoietin levels in rats with hemodynamically-mediated acute renal failure.

Adult female Wistar rats were injected with 125 mg/kg b.w. of human methemoglobin (M-Hb) in order to induce a first episode of hemodynamically-mediated acute renal failure (HMARF). Eleven days after the injection of M-Hb, other groups of rats received another equal dose of the drug in order to induce a second episode of HMARF. Evaluation of renal function, histopathology studies, and determinations of plasma and kidney erythropoietin (Epo) titers by radioimmunoassay in normoxic and hypoxic conditions were performed 1, 2, 3, 5 and 10 days after M-Hb administration. Treatment induced transient increases in plasma urea concentration, fractional sodium excretion, and urine volume, and significant depression in urine osmolality. In every case, the maximal effect of the first injection of M-Hb on the individual parameters was always greater than that of the second injection, and observed on the 5th post-injection day. Histologic sections showed interstitial cellular infiltration, desquamation of the proximal tubular epithelium and collapse or dilation of the tubular lumen. Treatment with M-Hb depressed Epo titers in both kidney homogenates and plasma in normoxic as well as hypoxic rats. Here again, the effect of the first injection of the drug was higher than that of the second one. These observations indicate that there is a negative correlation between kidney tubule injury and Epo production in normoxic and hypoxic conditions. The findings give support to the concept that Epo production is related to proximal tubular function.

Acute Kidney Injury↗

Severe pulmonary hypertension with diffuse smooth muscle proliferation of the lungs. Pulmonary tuberous sclerosis?

A 49-year-old man with normal intelligence and no cutaneous lesions had symptoms and signs of cor pulmonale. The chest roentgenogram showed an interstitial pattern. Hemodynamic studies revealed increased pulmonary arterial and wedge pressures. The patient died in shock, and the postmortem findings were a diffuse smooth muscle proliferation in the lungs as the cause of the pulmonary hypertension. We presume that this is a form of pulmonary tuberous sclerosis of which few cases are reported with such severe pulmonary hypertension as shown by our measurements.

Humans↗

[Eclampsia induced by skin allografts in spontaneously hypertensive rats].

In order to develop an experimental model for eclampsia, 22 female inbred Spontaneously Hypertensive Rats (SHR) were grafted with skin from Holtzman males. The implantation of four sequential grafts took place at an interval of ten days. Each SHR was mated with its corresponding skin donor ten days after the last graft. Five non grafted SHR mated with Holtzman males were used as controls. In most of the experimental rats that became pregnant we found changes which consisted in: low number of offspring, stillborn fetuses, abortions and growth delay. Renal function was evaluated before and during pregnancy showing a physiological increase in glomerular filtration of 7.5% (basal = 0.93 +/- 0.12 ml/min, peak = 1.00 +/- 0.12 ml/min) as compared with an increase of 166% (basal = 0.68 +/- 0.22 ml/min, peak = 1.85 +/- 0.33 ml/min) in the control group. Renal histology showed lesions corresponding to disseminated intravascular coagulation. These results indicate that the association of skin grafts and hypertension in these rats affects the normal development of pregnancy and suggest that immunological factors could be involved in experimental eclampsia.

Animals↗