Search PubMed⌕ Search

Biomedical subjects

J Palacios

Publications and source records attributed to J Palacios.

At least 109 records · Page 6Linked to original sources
PubMed1986

Somatostatin and Alzheimer's disease: a hypothesis.

Recent data suggest a disturbance of some brain somatostatin neurons in Alzheimer's disease. Moreover, some endocrine activities known to be regulated by somatostatin, such as growth hormone, thyroid-stimulating-hormone, somatomedins, as well as insulin and glucose metabolism, also seem to be affected in some patients. It is speculated that these changes are due to a global CNS and endocrine somatostatin defect in Alzheimer's disease and that the described endocrine imbalance may indirectly be responsible for at least part of the CNS pathology.

Alzheimer Disease↗
PubMed1986

Acute hemorrhagic conjunctivitis epidemic in Colon, Republic of Panama.

Acute hemorrhagic conjunctivitis has caused numerous outbreaks throughout Africa and Asia since it was first recognized in 1969 but did not involve the New World until 1981. This unprecedented outbreak reached Colon, Panama during August 1981 and by October 8,401 cases had been reported (14% of Colon's population). In October the Gorgas Memorial Laboratory and Ministry of Health conducted a survey in Colon to collect descriptive data on household living units, epidemiologic and clinical data from residents, and venous blood from all residents one year or older. The survey sampled 127 households and interviewed 608 people (1% of Colon's homes and 1% of the population). Overall 336 (55%) study subjects recalled having conjunctivitis. Disease rates differed according to residence; poor sectors of the city had 67% attack rates, lower class 52%, middle class 34%, and upper class 13%. Within each sector adults were more likely than children to be index cases, and communal bathrooms and household crowding were the most important risk factors for acute hemorrhagic conjunctivitis. Between 4-20% of people denying acute conjunctivitis had antibody to enterovirus 70 and may represent asymptomatic cases.

Adolescent↗
PubMed1986

Effects of intravenous ajmaline on atrial excitability and conduction in man.

Slow conduction of early extrastimuli and short refractory periods are some of the factors underlying atrial fibrillation in man. In order to study the effect of ajmaline, a class I antiarrhythmic agent, on these variables, we have performed electrophysiologic studies in 13 patients with and without atrial arrhythmias, before and after the intravenous administration of 1 mg kg-1 of ajmaline chlorhydrate. During paced rhythm with a 600 ms cycle length, extrastimuli were applied to the right atrial appendage, and conduction to the low septal right atrium and the coronary sinus were measured. Ajmaline prolonged P wave duration from 111 +/- 15 to 140 +/- 24 ms (P less than 0.001), conduction of baseline stimuli to low septal right atrium from 69 +/- 14 to 95 +/- 21 ms (P less than 0.001) and to coronary sinus from 127 +/- 18 to 165 +/- 29 ms (P less than 0.001). Atrial effective refractory period increased from 207 +/- 23 to 255 +/- 27 ms (P less than 0.001). Maximum conduction delay of early extrastimuli decreased at the low septal right atrium from 43 +/- 22 to 29 +/- 16 ms (P less than 0.25) and at the coronary sinus from 47 +/- 22 to 21 +/- 14 ms (P less than 0.001). These results show interesting electrophysiologic effects of ajmaline on atrial tissue, with reversion of some of the abnormalities underlying atrial fibrillation, and suggest an antiarrhythmic effect.

Ajmaline↗
PubMed1986

Postsurgical focal testicular infarct.

A 74-year-old man was surgically treated owing to incarcerated right inguinal hernia. Following surgery, he developed a focal hemorrhagic testicular infarct localized in the anterior pole of the right testis. The cause of the infarct seemed to bei either thrombosis or compression by edema of the veins draining the testis.

Aged↗
PubMed1986

Testicular toxoplasmosis in two men with the acquired immunodeficiency syndrome (AIDS).

Testicular infection due to Toxoplasma gondii in two young men with the acquired immunodeficiency syndrome manifested as a multifocal necrotizing lesion of the testicular parenchyma. At the periphery of the necrotic area were inflammatory infiltrates consisting mainly of eosinophilic leukocytes. The Toxoplasma organisms were mainly found within the necrotic seminiferous tubules, where they were identified with periodic acid-Schiff or May-Grünwald-Giemsa stains and by electron microscopy. The histologic pattern of this orchitis is characteristic and should be suspected in patients with severe disorders of the immune response.

Acquired Immunodeficiency Syndrome↗
PubMed1986

[Mediastinal teratomas. A clinical and pathologic study of 3 pediatric cases].

Mediastinal teratomas are reported in three children. Two cases: an eighteen-month-old female and a twelve-years-old female, were diagnosed of mature cystic teratoma. Third patient was a twelve-year-old male with an immature mediastinal teratoma. All tumors were located in anterior mediastinum. Mediastinal mature cystic teratomas were completely excised and their evolution were favourable. However, immature mediastinal teratoma infiltrated lung parenchyma and great blood vessels; in this case only a biopsy was performed. This patient died a month after surgical procedure. Clinical, radiological and pathological findings of mediastinal teratomas in childhood are commented. Prognostic factors and evolution of different histological types of mediastinal teratomas are evaluated.

Child↗
PubMed1983

Electrophysiologic studies in atrial fibrillation. Slow conduction of premature impulses: a possible manifestation of the background for reentry.

Extrastimulus-induced intraatrial conduction delays were measured in 12 patients with documented episodes of atrial fibrillation (AF) by recording atrial electrograms at the high right atrium, His bundle region, and coronary sinus. Seventeen patients with and without heart disease, but without atrial arrhythmias served as the control group. During baseline-paced atrial rhythms, a conduction delay zone could be delineated, near the atrial effective refractory period, during which all extrastimuli produced conduction delays. When compared at the same paced cycle lengths (500 to 650 ms), the patients with AF had shorter atrial effective refractory periods (mean +/- standard deviation 206 +/- 24.1 versus 233 +/- 28.2 in control patients, p less than 0.02), wider conduction delay zones (79 +/- 21.7 ms versus 52 +/- 21 in control patients, p less than 0.01), and longer conduction delays both to the His bundle region (64 +/- 18.3 ms versus 35 +/- 21.7 in control patients, p less than 0.005) and the coronary sinus (76 +/- 18.9 ms versus 35 +/- 16.1 in control patients, p less than 0.001). Repetitive atrial responses were recorded in 6 patients with AF and in 9 control subjects. Sinus nodal function abnormalities were detected in 6 of the patients with fibrillation. Patients with AF had a higher tendency than control subjects to develop slow intraatrial conduction, as well as shorter effective refractory periods. Since both features would favor reentry, they may be the electrophysiologic manifestations of the abnormalities making these patients prone to atrial reentrant arrhythmias. Repetitive atrial responses were of no predictive value. Sinus nodal dysfunction was frequently found, but was not essential for the occurrence of AF.

Adult↗
PubMed1982

[Physiological effects of the ingestion of Vicia ervila W. (lentils) in chickens].

Five week old chickens have been fed a diet of 30% lentils. The animals showed an 80% growth decrease and a higher excitability level in relation to the control group. The animals were slaughtered after the 2nd, 3rd, 4th and 5th week of age. The gall-bladder showed a 20% size increase in the 4th week. The relation pancreas weight/body weight is significant with the highest proportion at 34% in the 4th week. No important differences have been observed in D.N.A. content in pancreatic tissue between animals fed the lentils diet and the control group. The enzimatic activity has been analyzed. The proteolytic activity varies significantly, being 22% higher in the lentils group in the 3rd week, and 30% in the 4th week. The amylasic activity showed significant statistical differences, being 23% higher in the 5th week.

Animals↗
PubMed1981

Rotavirus. II. Viruses associated with acute gastroenteritis in children.

Rotavirus was investigated in the feces of 232 children under five years of age with acute infectious gastroenteritis by means of viral RNA electrophoretic technique. 15.1 per cent of cases were positive and no predominance was observed regarding age or seasonal period. Approximately 50 per cent corresponded to one of the two rotavirus types, byt type 2 (2 L) was predominant in the first six months of the year and type 1 (2 S) in the other six. Results are consistent with those obtained by other authors for it is considered that approximately 20 per cent of acute diarrheas during infancy are caused by viral agents.

Acute Disease↗
PubMedDate not supplied

The apical mitochondria-rich cells of the mammalian epididymis.

The morphology and function of the apical mitochondria-rich cells in the mammalian ductus epididymidis epithelium are revised. These cells are similar in all mammalian species studied. Apical mitochondria-rich cells are scarce (1-5 cells/100 principal cells) and are mainly found in the initial epididymal segments. Their morphology varies from slender cells that extend from the basal lamina to the epididymal lumen, to round cells that protrude into the lumen and are not in contact with the basal lamina. Their cytoplasm is more electron-dense than that of principal cells and contains more mitochondria which, in some species, are surrounded by rough endoplasmic reticulum cisternae. The adluminal cytoplasm displays a few short microvilli and contains many acid phosphatase positive vesicles. Apical mitochondria-rich cells differ from the principal cells in some histochemical features such as: (a) different lectin-staining pattern; (b) more intense reaction to the enzymatic activities: carbonic anhydrase, Ca(2+)-ATPase, peanut-agglutinin-sialidase, NADP dehydrogenase, succinate dehydrogenase, alpha-galactosidase and beta-galactosidase; (c) more intense immunoreaction to several cytokeratin types and to estradiol-related receptor protein; (d) weaker immunoreaction to epithelial membrane antigen and to retinol-binding protein. Although the function of the apical mitochondria-rich cells is still unknown, the following possible functions have been suggested: holocrine secretion; cooperation with the principal cells in epididymal reabsorption of testicular fluid; and acidification of epididymal fluid. Experimental results suggest that differentiation and maintenance of apical mitochondria-rich cells are not under androgen control and that these cells are sensitive to estrogen stimulation.

Animals↗
PubMedDate not supplied

Posttransplant CD30 (Ki-1)-positive anaplastic large cell lymphoma. Report of a case with presentation as a pleural effusion.

BACKGROUND: Posttransplant lymphoproliferative disorders (PTLDs) are almost always of B-cell derivation and have a strong association with Epstein-Barr virus (EBV). Only rare cases of CD30 (Ki-1)-positive anaplastic large cell (ALC) lymphomas in transplant recipients have been described. EBV has been studied in few of these cases. Pleural effusion is an uncommon clinical manifestation of both PTLDs and CD30-positive ALC lymphoma. CASE: A 60-year-old, male renal transplant recipient presented with fever and pleural effusion. Cytologic examination of the effusion revealed a large cell lymphoma. Immunocytologic studies disclosed a T-cell phenotype. Subsequently a cutaneous lesion and an accessory spleen were observed, and cervical lymphadenopathies developed. Fine needle aspiration of lymph nodes confirmed the presence of lymphoma. Histologic and immunohistochemical studies of the lymph nodes, skin and accessory spleen revealed the presence of CD30-positive, T-cell, ALC lymphoma. No EBV DNA was detected by polymerase chain reaction analysis. Despite chemotherapy, the patient died seven months after the initial cytologic diagnosis of lymphoma. CONCLUSION: CD30-positive ALC lymphomas are an uncommon variant of PTLDs that should be considered in the differential diagnosis of neoplastic disorders arising in immunosuppressed patients. Cytology and immunocytochemistry are useful diagnostic procedures for their early detection.

Antigens, CD↗
PubMedDate not supplied

Adrenal gland leiomyoma in a child with acquired immunodeficiency syndrome.

An adrenal gland leiomyoma was incidentally found at autopsy in a 2-year-old boy with acquired immunodeficiency syndrome (AIDS). Smooth muscle neoplasms have been described in pediatric AIDS and affect mainly the tracheobronchopulmonary, gastrointestinal, and hepatobiliary systems. An association between Epstein-Barr virus (EBV) and smooth muscle tumors in patients with AIDS has been described. This case is the first leiomyoma to be reported in the adrenal gland of a child with AIDS. EBV genome was demonstrated in the tumor by polymerase chain reaction.

Acquired Immunodeficiency Syndrome↗