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Biomedical subjects

A Gonzalez

Publications and source records attributed to A Gonzalez.

At least 217 records · Page 12Linked to original sources
PubMed1989

Specific estrogen-induced cell proliferation of cultured Syrian hamster renal proximal tubular cells in serum-free chemically defined media.

It has long been recognized that the renal proximal tubular epithelium of the hamster is a bona fide estrogen target tissue. The effect of estrogens on the growth of proximal tubule cell explants and dissociated single cells derived from these explant outgrowths has been studied in culture. Renal tubular cells were grown on a PF-HR-9 basement membrane under serum-free chemically defined culture conditions. The cells of tissue explant outgrowths exhibited ultrastructural features typical of proximal tubules including junctional complexes, numerous mitochondria, peroxisomes, and microvilli. At 7-14 days in culture, cell number was enhanced 3-fold in the presence of either 17 beta-estradiol or diethylstilbestrol. Maximal proliferative response was observed at hormone concentrations of 0.6-1 nM. A similar 3-fold increase in cell number was also seen at 1 nM 17 beta-estradiol in subcultured dissociated single tubular cells derived from hamster renal tubular explant outgrowths at 21 days in culture. Neither progesterone, 5 alpha-dihydrotestosterone, nor the inactive diethylstilbestrol metabolite beta-dienestrol elicited this mitogenic effect. Concomitant exposure of tamoxifen at 3-fold molar excess in culture completely abolished the increase in cell number seen with 17 beta-estradiol. Tubular cells obtained from hamster medulla did not exhibit this proliferative response when exposed similarly to 17 beta-estradiol or diethylstilbestrol. The proliferative effect of estrogens on proximal tubular cell growth appears to be species specific since 17 beta-estradiol did not alter the growth of either rat or guinea pig proximal tubules in culture. In addition, at 7-10 days in culture in the presence of 17 beta-estradiol, [3H]thymidine labeling of hamster tubular cells was enhanced 3-fold. A similar increase in mitoses was also observed in cultures containing these potent estrogens during the same time interval of estrogen exposure. These results clearly indicate that estrogens can directly induce primary epithelial cell proliferation at physiologic concentrations and provide strong additional evidence for an important hormonal role in the neoplastic transformation of the hamster kidney.

Animals↗
PubMed1989

Single photon emission computed tomography (SPECT) with [123I]IMP in the differential diagnosis of psychiatric disorders.

Single photon emission computed tomography (SPECT) with [123I]N-isopropyl iodoamphetamine--[123I]IMP--was used to study regional cerebral blood flow (rCBF) in 94 psychiatric patients and six controls. Patients with dementias had distinct brain-image patterns, consistent with the expected neuropathology. Major depressives had decreased cortical and subcortical rCBF. Increased caudate rCBF was observed in schizophrenics and other psychoses with positive symptoms. SPECT is a practical method of functional brain imaging with potential in the differential diagnosis of neuropsychiatric disorders. Further studies are needed to assess the effect of other variables on brain-image patterns.

AIDS Dementia Complex↗
PubMed1989

Herpes simplex retinitis in the mouse. Clinicopathologic correlations.

BALB/c mice inoculated with herpes simplex virus type 1 in one anterior chamber develop retinitis with subsequent retinal necrosis in the contralateral eye. The clinical features of this disease were characterized with indirect ophthalmoscopy and fundus photography. Three phases of the disease were delineated: (1) acute retinitis; (2) retinal necrosis; and (3) resolution; the clinical findings in each phase were correlated with the microscopic features. In addition, we compared the virus titers from individual animals with and without clinical evidence of retinitis to demonstrate that retinal inflammation correlated with the titer of virus in the uninoculated eye. This animal model is useful for the analysis of the clinical, virologic and immunologic manifestations of herpetic retinitis.

Animals↗
PubMed1989

Induced changes of the peritoneal diffusion capacity by smoking, intraabdominal hypertension and omentectomy.

UNLABELLED: Peritoneal membrane suffers in some CAPD patients changes which modify its functionalism. In order to know whether these changes could be expected or appropriate, it is necessary to explore the general and particular conditions which can alter peritoneal physiology. Three aspects, smoking, intraabdominal hyperpressure and and omentectomy are situations which have not been included in the studies of peritoneal physiology. PATIENTS: The control group was constituted by 23 patients. Diabetics were studied as a separate group, with their own 10 patient controls. Smokers (1-20 cigarettes per day): 15 were non-diabetic patients, 9 were females. Diabetic smokers: 7 patients. Intraabdominal hyperpressure was determined by two big polycycstic kidneys (PCKD) in 8 patients, none diabetic. Omentectomy was performed in 6 non-diabetic and 9 diabetic patients. In all cases the procedure was prescribed because of an early catheter entrapment. Smoker patients show significant higher MTCs values for urea and creatinine than controls, but the slightly lower ultrafiltration value did not reached significant difference. Polycystic kidney patients showed lower MTCs values in respect to controls. Ultrafiltration capacity was similar. Omentectomized patients did not show any differences in respect to controls. In the diabetic patients group, neither ultrafiltration nor MTCs values presented significant differences between the established subgroups. So, smoking did not seem to induce higher MTC values as in the non-diabetic group. In conclusion, and according to the present results, two more situations should be taken into account in the evaluation of the peritoneal membrane dialyzing capacities: smoking, which increases diffusion capacity except for diabetics and PCKD with tow big kidneys, which decreases this capacity.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdomen↗
PubMed1989

[Echocardiographic diagnosis of a hydatid cyst localized at the intraventricular septum].

A patient with case of an hydatid cyst located in the interventricular septum is presented. The two-dimensional echocardiography clearly visualized the cystic configuration of the disease, demonstrating its great usefulness for detecting this type of cardiac pathology. The patient underwent surgery with extracorporeal circulation. In this article we also discuss the surgical indications of this pathology.

Adult↗
PubMed1989

Immunological approaches to contraception in dogs.

The demand for safe, effective and cost-efficient means of pet population control has generated interest in the development of alternatives to surgical gonadectomy. The purpose of this review is to discuss the potential of immunological approaches to fertility control and to outline recent developments that may aid their design. Among the most promising candidates for immunoneutralization is gonadotrophin releasing hormone (GnRH). We have developed a reliable and reproducible GnRH-protein conjugate antigen and demonstrated that immunologically induced infertility is possible in dogs.

Adjuvants, Immunologic↗
PubMed1988

Central distribution of the efferent cells and the primary afferent fibers of the trigeminal nerve in Pleurodeles waltlii (Amphibia, Urodela).

As part of a study on the organization of the brainstem in a primitive group of vertebrates, the efferent cells and primary afferent fibers of the urodele amphibian Pleurodeles waltlii were examined by means of retrograde and anterograde axonal transport and anterograde degeneration. The trigeminal motor nucleus is located in the periventricular gray just medial to the sulcus limitans. Its rostral part is a band of pear-shaped cells lying parallel to the wall of the ventricle, whereas its caudal part is a round mass consisting of polygonal cells. In addition, a small group of scattered neurons is situated ventral to the rostral part of the nucleus. The primary afferent fibers enter the brainstem in the dorsal two-thirds of the trigeminal root. They diverge into a short ascending and a long descending tract. The former distributes its axons to the principal sensory trigeminal nucleus, which is an ill-defined cell group located at the ventrolateral edge of the periventricular gray. In the descending tract, the fibers of the ophthalmic nerve are predominantly located ventromedially, and those of the maxillomandibular nerve dorsolaterally. A fascicle of the ophthalmic nerve leaves the descending tract and, apparently, makes contact with the accessory abducens nucleus. The descending tract extends caudally into the three upper cervical segments of the spinal cord. The mesencephalic trigeminal nucleus consists of conspicuous large cells, which are scattered through the tectum of the mesencephalon. The cells with peripheral branches in the ophthalmic nerve are mainly located in the caudal half of the tectum, and those with peripheral branches in the maxillomandibular nerve in the rostral half. Collaterals of the central branches of the mesencephalic trigeminal system were traced to an area of the periventricular gray situated between the motor nucleus and the principal sensory nucleus of the trigeminus.

Animals↗
PubMed1988

Human promyelocytic leukemia HL-60 cell proliferation and c-myc protein expression are inhibited by an antisense pentadecadeoxynucleotide targeted against c-myc mRNA.

The human promyelocytic leukemia cell line HL-60 overexpresses the c-myc protooncogene. A calculated secondary structure for c-myc mRNA placed the initiation codon in a bulge of a weakly base-paired region. Treatment of HL-60 cells with 5' d(AACGTTGAGGGGCAT) 3', complementary to the initiation codon and the next four codons of c-myc mRNA, inhibited c-myc protein expression in a dose-dependent manner. However, treatment of HL-60 cells with 5' d(TTGGGATAACACTTA) 3', complementary to nucleotides 17-31 of vesicular stomatitis virus matrix protein mRNA, displayed no such effects. These results agree with analogous studies of normal human T lymphocytes [Heikkila, R., Schwab, G., Wickstrom, E., Loke, S. L., Pluznik, D. H., Watt, R. & Neckers, L. M. (1987) Nature (London) 328, 445-449], except that only one-third as much oligomer was needed for a comparable effect. Proliferation of HL-60 cells in culture was inhibited in a sequence-specific, dose-dependent manner by the c-myc-complementary oligomer, but neither the oligomer complementary to vesicular stomatitis virus matrix protein mRNA nor 5' d(CATTTCTTGCTCTCC) 3', complementary to nucleotides 5399-5413 of human immunodeficiency virus tat gene mRNA, inhibited proliferation. It thus appears that antisense oligodeoxynucleotides added to myc-transformed cells via culture medium are capable of eliciting sequence-specific, dose-dependent inhibition of c-myc protein expression and cell proliferation.

Base Sequence↗
PubMed1988

Treatment of chromoblastomycosis with itraconazole.

The results of long-term itraconazole therapy in 10 patients with active chromoblastomycosis due to F. pedrosoi were reported. Therapy consisted of 100 or 200 mg/day of itraconazole, the length of therapy depending on the patient's response (12 to 24 months). This new triazole proved effective in reducing the number, size, and severity of the lesions in nine of the patients. Those patients with minor involvement profited more from therapy and were cured; patients with moderate involvement achieved either minor or major improvement. In most cases, signs and symptoms began to improve after 6 months of therapy. Mycological tests (in which tissue samples were treated with potassium hydroxide and cultured) became negative in six patients, but the fungus was eradicated in only three patients. Itraconazole produced no side effects. In spite of the need for long-term therapy, this new azole derivative effectively controls the disease.

Antifungal Agents↗
PubMed1988

Improvement in exercise capacity and exercise hemodynamics 3 months after double-balloon, catheter balloon valvuloplasty treatment of patients with symptomatic mitral stenosis.

Clinical status, exercise treadmill performance, and hemodynamics were determined in 24 patients with symptomatic mitral stenosis before catheter balloon valvuloplasty (CBV) and at 3 months follow-up. Hemodynamic determinations at rest showed that mitral CBV performed by the double-balloon technique resulted in significant immediate decreases in mean pulmonary arterial wedge pressure (28 +/- 7 to 16 +/- 5 mm Hg, p less than .01), mean pulmonary arterial pressure (41 +/- 11 to 33 +/- 10 mm Hg, p less than .05), and mitral valve gradient (16 +/- 7 to 6 +/- 3 mm Hg, p less than .01), and significant increases in cardiac output (4.3 +/- 1.1 to 5.0 +/- 1.4 liters/min, p less than .01). Mitral valve area increased from 1.0 +/- 0.3 to 2.2 +/- 0.7 cm2 (p less than .01). The mitral valve area was unchanged (2.0 +/- 0.7 cm2, p = NS) at 3 months. The lower pulmonary arterial wedge pressure, pulmonary arterial pressure, and mitral valve gradient persisted at 3 month follow-up catheterization. Clinical examinations showed that before CBV, 21 of 24 patients were in New York Heart Association functional class III or IV; 3 months after CBV, 22 patients were in class I or II. Before CBV, the mean exercise treadmill time was 5.9 +/- 3.2 min and it had increased to 9.8 +/- 2.9 min (p less than .01) by the 3 month follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

[Use of cultured, virus-infected cells to study the biogenesis of polarity of epithelial cells].

The major characteristic of the eucaryote cell is the presence of specialized organelles in which macromolecular components responsible for various subcellular functions are segregated. The membranes of these organelles serve not only as divisions between the various cytoplasmic compartments, but also provide scaffolding within which the macromolecular complexes of the organelle assemble and become functionally integrated. It is obvious that because of the degree of complexity resulting from the existence of numerous compartments and membrane systems, the development of a genetic programme in a eucaryote cell requires not only the transcription of specific genes and translation in the cytoplasma of the resultant messenger RNA, but also the activity of mechanisms which ensure that each polypeptide reaches the site of its function, which may be in the cytosol, in a membrane, or in the luminal cavity of an organelle. In the special case of membrane proteins, such mechanisms must result not only in the specific distribution of polypeptides newly synthesized in the various types of cell membrane, but also the arrangement of them required in the lipid bi-layer necessary for their normal function.

Animals↗