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Biomedical subjects

O Larraza

Publications and source records attributed to O Larraza.

17 recordsLinked to original sources

The spectrum of clinical and pathological manifestations of AIDS in a consecutive series of autopsied patients in Mexico.

OBJECTIVE: Little is known about the clinical profile of AIDS in Latin American populations. This study characterizes the clinical and pathological manifestations of AIDS in a representative series of Mexican AIDS patients at autopsy. DESIGN: The clinical and pathological findings were abstracted retrospectively for a sequential series of autopsied AIDS patients. SETTING: Autopsies were conducted at the four major tertiary level hospitals that serve the majority of AIDS patients in Mexico City. PATIENTS: Subjects included 177 consecutive patients diagnosed with AIDS between March 1984 and January 1989 who subsequently died and were autopsied in the same period in the study hospitals. MAIN OUTCOME MEASURES: Demographic characteristics, including age, gender, residence, socioeconomic status, and risk group; clinical presentation and autopsy findings, including opportunistic infections and malignancies. RESULTS: Sixty per cent of the AIDS patients presented with wasting syndrome. The most common infections were cytomegalovirus (69%), tuberculosis (25%), and Pneumocystis carinii pneumonia (24%). Central nervous system infections were also common and included toxoplasmosis (19%) and cryptococcoses (10%). Kaposi's sarcoma was present in 30% of cases and non-Hodgkin's lymphoma in 9%. CONCLUSION: Clinical manifestation, and types and frequency of opportunistic infections in our Mexican AIDS patients were more similar to those seen in AIDS patients in Africa and Haiti than in the United States and Europe. These findings suggest that the AIDS epidemic in Mexico has an 'intermediate' pattern and may be a prototype for Latin American countries.

Acquired Immunodeficiency Syndrome↗

The role of the endoscopic biopsy in the diagnosis of gastric lymphoma: a morphologic and immunohistochemical reappraisal.

Forty-three endoscopic biopsies from 29 patients with confirmed gastric lymphoma (GL) were analyzed retrospectively to establish the morphologic criteria of greatest diagnostic significance. An average of 10 tissue samples was obtained at each endoscopy. In 44% of the cases, lymphoma was discovered in only one or two of the tissue portions. Eighteen lymphomas were primary, six were probably primary, and five were generalized. The diagnosis of lymphoma was originally suspected or established in 46% of the biopsies. However, a review of the histologic sections indicated that the changes, either diagnostic of or compatible with lymphoma, were present in 75% and 18% of the sections, respectively. Most diagnostic errors consisted of confusion with diffuse lymphoid infiltrates in chronic gastritis and/or peptic ulcer, and less frequently with poorly differentiated carcinoma. In those cases confused with chronic gastritis or peptic ulcer, biopsies showed centrocyte-like cells of the standard type or small lymphocytes which produced: (1) a marked increase in density of the lymphoid infiltrate in the gastric mucosa, (2) massive substitution of gastric glands by lymphoid infiltration, and (3) a collection of lymphocytes infiltrating and partially destroying isolated glands (lymphoepithelial lesion). From 48 biopsies having intense benign lymphoid infiltrates, three were interpreted (by means of a blinded study) as compatible with GL. In poorly differentiated neoplasms (blastic and pleomorphic types), cytologic features were sufficient to diagnose GL or malignant neoplasms; immunohistochemical techniques were useful to define their lymphoid nature. It is concluded that many GLs can be suspected or correctly diagnosed by routine endoscopic biopsy.

Adult↗

Differential response to aminergic stimuli and biological behavior of growth hormone secreting pituitary adenomas.

Growth hormone (GH) serum levels in response to the administration of aminergic drugs and thyroliberine (TRH) were determined in a group of 34 acromegalics. Administration of bromocriptine (10 mg single oral dose) was followed by a decrease in GH below 60% control values in 35% of the cases. Administration of diazepam (10 mg single oral dose) to those cases not responding to bromocriptine induced a decrease in GH in 58% of the cases and an increase in GH in 42%. Administration of cyproheptadine (24 mg/day for one month) to those cases not responding to bromocriptine or with increased GH after the administration of diazepam, decreased GH in 75%, while increased GH in 25% of the cases. TRH 200 micrograms single I.V. dose induced increase of 128% GH basal level in 65% of cases (TRH positive) which correlated with more benign clinical course, decreased GH levels in response to bromocriptine, increased PRL levels, PRL-GH mixed secreting adenomas in immunohistochemistry studies, presence of granulated cells in electron microscopy studies and normalization of GH in the majority of surgically treated cases. By contrast, TRH negative cells correlated with aggressive tumor growth, lack of response to bromocriptine, normal PRL levels, pure GH secreting adenomas by immunohistochemistry, poorly granulated cells and lack of response to surgical treatment. Results suggest that there is more than one type of acromegaly that might be distinguished by the aminergic control on GH secretion.

Acromegaly↗

Signet-ring lymphoma: report of a case.

Signet-ring lymphoma is a rare entity in which the synthesis or secretion of immunoglobulins is impaired, producing a signet-ring appearance to the lymphoma cells. A case of this type of lymphoma is described, and the cytologic aspects of the cells obtained from the fixative fluid are described.

Aged↗

Inherited male pseudohermaphroditism due to gonadotrophin unresponsiveness.

An inherited form of incomplete male pseudohermaphroditism was studied in two post-pubertal and one pre-pubertal sibling. All patients presented a 46XY karyotype infantile female external genitalia, lack of breast development and sexual hair. Persistently elevated serum levels of gonadotrophins with normal pituitary responsiveness to LRH were found. Serum 17-OH progesterone, androstenedione, and testosterone levels were extremely low before and after gonadal stimulation with hCG. Laparotomy revealed absence of Wolffian and Mullerian derivatives. Testes were small and cryptorchidic. Microscopic and ultrastructural examination revealed seminiferous tubules with absence of spermatogenesis and normal Sertoli cells. The interstitial spaces were mainly occupied by poorly differentiated cells although in the post-pubertal patients there were small and randomly distributed nodules of Leydig cells without crystaloids. Incubation of testicular tissue from one post-pubertal patient with [14C]acetate showed lack of 14C-incorporation into appropriate steroid carriers. These data were interpreted as demonstrating that gonadotrophin resistance was the underlying abnormality of this syndrome, representing the human counter part of the "vet" pseudohermaphroditic rat.

Adolescent↗

Serum growth hormone and ultrastructural studies of adenohypophysial tissue in bromocriptine treated acromegalic patients.

The therapeutic effectiveness of bromocriptine as well as the post-operative ultrastructural aspects of treated pituitary adenomas were investigated in five acromegalic patients. Although concentrations of GH basal decreased and the glucose tolerance test and the TSH responses were significantly improved, the release of GH induced by TRH was not prevented by the dopaminergic agonist. Adenomatous cells were densely granulated and contained a dilated endoplasmic reticulum. Misplaced exocytosis was frequently observed. These findings clearly indicate that bromocriptine inhibits the spontaneous release of GH but does not interfere with the abnormal GH response to TRH. This suggests a separate site of action. The drug seems not to block the synthesizing activity of the adenomatous cell, a finding in accordance with clinical observations that warns against its use as a single therapeutic agent.

Acromegaly↗

Carcinoid of the uterine cervix: additional observations on a new tumor entity.

Twelve carcinoid tumors of the uterine cervix were studied. Based on the microscopic structure, they were divided into well-differentiated and poorly differentiated types. Both tumor varieties affected adult women. The clinical and gross features of these tumors were indistinguishable from those of invasive squamous cell carcinoma. Of the 12 patients, six died, four with poorly differentiated carcinoid and two with the well-differentiated type. Three patients are alive and symptom-free 9 months to 2 years after treatment; the remaining three were lost to follow-up. Microscopically, four well-differentiated carcinoids showed argyrophil cells, and ultrastructurally two had neurosecretory granules. One of the well-differentiated carcinoids resembled islet cell carcinoma and two had areas resembling medullary carcinoma of the thyroid. The poorly differentiated type of carcinoid had a histologic structure and a cell population very similar to that of the oat cell carcinoma of the lung. Of this group, four were argyrophilic, and by electron microscopy four contained pleomorphic secretory granules. It is considered that these tumors arise from the normal argyrophil cell of the cervix and are part of the group of neoplasms of the diffuse endocrine cell system (APUD).

Adult↗

[Multiple paragangliomas. The problem of its localization. Report of the first case studied with 131I meta-iodobenzylguanidine in our milieu and review of the literature].

We report the case of a young woman, with an 8 year history of paroxysmal episodes of dyspnea, palpitations, blurred vision, tremors, precordial oppression and hypertension; the diagnosis of a chromaffin tumor was established, with an increase in serum and urine catecholamines level. She had three surgical interventions and also the following studies: abdominal and pelvic ultrasound, computed tomography, cavography; selective arteriography, and infusion of the meta iodobenzyl-guanidine 131, which localizes tissues hypersecretors rich in catecholamines.

3-Iodobenzylguanidine↗