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Biomedical subjects

A Ruiz

Publications and source records attributed to A Ruiz.

At least 217 records · Page 12Linked to original sources
PubMed1995

Chromosome 9p deletions in cutaneous malignant melanoma tumors: the minimal deleted region involves markers outside the p16 (CDKN2) gene.

We have analyzed 12 microsatellite markers on chromosome 9p in 54 paired cutaneous malignant melanoma (CMM) tumors and normal tissues. Forty-six percent of the tumors, including two in situ CMMs, showed loss of heterozygosity (LOH) at 9p. Only one tumor was homozygously deleted for 9p markers. The smallest deleted region was defined by five tumors and included markers D9S126 to D9S259. Loss of eight or more markers correlated significantly with worse prognosis (P < .002). Among the primary tumors, 87.5% of those with large deletions have a high risk of metastasis, as compared with only 18% of those without deletions or with loss of fewer than 8 markers (P < .001). It was not possible to demonstrate homozygous deletions of p16 in any of the CMM tumors. In four tumors, the LOH for 9p markers did not involve p16. The reported data suggest the existence of several tumor suppressor genes at 9p that are involved in the predisposition to and/or progression of CMM and exclude p16 from involvement in the early development of some melanoma tumors.

Base Sequence↗
PubMed1995

[Evaluation of specificity of pneumococcal antigen detection in clinical samples by using the polymerase chain reaction as reference method].

BACKGROUND: Sensitivity and specificity of latex agglutination test on samples obtained by transthoracic needle aspiration was evaluated for diagnosis of pneumococcal pneumonia by using the polymerase chain reaction as reference method. METHODS: Samples from 29 patients with community acquired pneumonia were processed for culture, antigen detection and polymerase chain reaction. The latex agglutination test was performed with a reagents kit (Slidex méningite kit, BioMérieux, France) using the procedure recommended by the manufacturer. The polymerase chain reaction was carried out by using two primers: Pn2x up and Pn2x down that amplify the PBP2x gene of Streptococcus pneumoniae. RESULTS: Culture was positive in 5 patients, antigen detection in 15 and polymerase chain reaction in 14 patients. The specificity of latex agglutination test was 93% compared with polymerase chain reaction as reference method. CONCLUSION: The pneumococcal antigen detection by latex agglutination test is as sensitive as the polymerase chain reaction, it seems to be highly specific, and it is rapid and easy to perform.

Antigens, Bacterial↗
PubMed1995

One day estrous cycle shortening induced by antiprogestagen RU486 administration in proestrus to 4-day cyclic rats.

Administration of 4 mg of the antiprogestagen RU486 to 4-day cyclic rats in proestrus, which blocks proestrous and diestrous progesterone actions, induced a one day shortening of the ovarian cycle and a reduction of the ovulation rate in the following cycle. These effects were not present when RU486 was administered in estrus or metestrus. RU486 injections either in proestrus or estrus increased the serum levels of LH and 17 beta-estradiol during metestrus. However, only rats injected with RU486 in proestrus presented a 24 hour advancement of the preovulatory surge of gonadotropins and a lack of the LH-inhibiting effect of exogenous estradiol. These results suggest that, in 4-day cyclic rats, the secretion of progesterone by the corpora lutea during diestrous phase retards the follicular development by lowering the serum concentrations of LH, whereas progesterone secretion by the preovulatory follicles in proestrus regulates the estrous cycle length by antagonizing the desensitization of the pituitary to the estrogen negative feedback on LH secretion.

Animals↗
PubMed1994

Two cases of deep dyslexia in unilingual hispanophone aphasics.

This paper addresses the interaction between a particular cognitive property inherent to the human brain, i.e., the capacity to learn how to process written information in a manner such that reading words aloud can become a standard aspect of overt behavior, and some of the culture-linked characteristics of the written codes invented by the species. First, the paper reiterates that the Spanish written code is transparent to the point of entailing full graphophonemic conversion, i.e., reading behavior is possible without access to one's memory of written words (to one's "logographic lexicon"). The Ardila claim (Ardila, 1991; Ardila, Rosselli, & Pinzon, 1989) that certain clinical forms of acquired reading disorders which have been reported to occur among various cultural subgroups do not occur among unilingual readers of Spanish is then summarized. This is followed by two brief case reports of acquired aphasia in native speakers and fluent readers of Spanish; prototypical "deep dyslexia" was documented to exist in both cases (Ruiz & Ansaldo, 1990). The Ardila claim is thereafter assessed by reference to the notions of surface, phonological, and deep dyslexia; parameters such as educational background are taken into account in this discussion.

Aphasia↗
PubMed1994

Estradiol receptors in combination with neu or myc oncogene amplifications might define new subtypes of breast cancer.

Amplifications of neu and c-myc were evaluated in 218 and 145 breast cancers (BC), respectively. Oncogene amplifications were determined for the most part by Southern blot. An association between the proportion of nodes affected and the intensity of neu amplification in estadiol receptor negative (ER-) BC was found (P = 0.028), which was confirmed by the multi-factor analysis of variance (P = 0.05). A significantly greater incidence in neu amplifications among BC with metastases was also found (P = 0.031). A strong association (P = 0.01) between the neu and myc amplification was observed. There is a strong association between myc amplification and ER- BC (P < 0.01). It is concluded that (1) the combination ER- with neu amplification might define a new group of more aggressive BC, as is suggested by their associated nodal involvement; (2) the linkage of myc amplifications with ER- BC and high grade of neu amplification might reflect a trait of tumor aggressivity.

Adult↗
PubMed1994

Immunohistochemical localization of intracellular progesterone and glucocorticoid receptors in the rabbit lung.

We have determined the presence and distribution of intracellular progesterone receptors (PRs) and glucocorticoid receptors (GRs) in the lung of adult female rabbits using immunohistochemistry. The effects of ovariectomy and administration of oestradiol benzoate (10 micrograms for 3 consecutive days) upon PR and GR immunoreactivity were also studied. The results demonstrated the presence of both steroid hormone receptors in the female rabbit lung. PR and GR immunoreactivity was predominantly nuclear and located in alveolar epithelial cells and various interstitial cells such as polymorphonuclear leucocytes. Tissue distribution of both receptors was similar in all cases. Oestradiol treatment induced a marked increase in the number of PR immunoreactive cells compared with intact and ovariectomized female animals. Neither ovariectomy nor oestradiol treatment modified the number of GR immunoreactive cells. The presence and localization of intracellular PRs and GRs in several lung cell types suggest that they may play an important role in mediating the effects of progesterone and glucocorticoids in various physiological processes in the rabbit lung. The data also indicated an oestrogen regulation of PRs in the rabbit lung.

Animals↗
PubMed1994

Effect of antiprogestagen RU486 on both natural and prolactin-induced morphological luteolysis in rat..

Adult female cyclic rats were hypophysectomized and their pituitary glands autotransplanted beneath the left kidney capsule (Aptr) on day 1 (metestrus). To induce the luteolytic effect of prolactin (PRL) the rats were injected s.c. with 0.4 mg of 2-bromo-alpha-ergocryptine (CB154) on cycle days 12, 13 and 14. Other groups of Aptr rats were injected daily with CB154 or ethanol vehicle from day 12 to day 23. To study the role of progesterone (P) on the luteotrophic effect of PRL as well as on the natural and on the PRL-induced luteolysis, rats without CB154 treatment or with long or short CB154 treatment were injected s. c. with 2 mg of the antiprogestagen RU486 or 0.1 ml oil from day 1 to day 23. From each rat the mean weight of the corpus luteum (CL) was noted on day 24. The serum PRL level rose from day 1 to day 12 and fell thereafter by day 15 in CB154-treated rats. The serum level of PRL rose again in short term CB154-treated rats, and remained low in long term CB154-treated rats. No effect of RU486 on serum PRL levels was noted in any group. The serum P level fell rapidly as the treatment with CB154 began after day 12. Neither the rise in serum PRL after day 15 in short term CB154-treated rats nor RU486 treatment affected the P level. Treatment with RU486 did not affect the CL weight on day 24 in ethanol vehicle injected rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Use of thallium-201 brain SPECT to differentiate cerebral lymphoma from toxoplasma encephalitis in AIDS patients.

PURPOSE: To determine whether thallium-201 brain single-photon emission CT could be used to make the distinction between central nervous system lymphoma and toxoplasma encephalitis, which may not be possible by routine MR and CT. METHODS: A total of 37 patients with acquired immunodeficiency syndrome who had intracranial mass lesions found during a 9-month prospective study by either MR or CT underwent further evaluation with Tl-201 brain single-photon emission CT. RESULTS: Twelve patients had increased intense focal Tl-201 uptake. All of these patients had either biopsy- or autopsy-proven lymphoma. Twenty-five of the patients studied had no Tl-201 brain uptake in the lesion(s); 24 of these patients had toxoplasma encephalitis on clinical follow-up. One patient with no Tl-201 uptake was found by cerebrospinal fluid analysis to have mycobacterium tuberculosis abscess. CONCLUSION: Patients with acquired immunodeficiency syndrome who have intracranial mass lesions on MR or CT may benefit from Tl-201 brain single-photon emission CT because it can help distinguish between lymphoma and infectious lesions such as toxoplasma encephalitis.

AIDS Dementia Complex↗
PubMed1994

[Effect of treatment with 13-cis-retinoic acid and ara-C on the hematopoietic stem cells of patients with myelodysplastic syndromes].

PURPOSE: To assess the "in vivo" effect of 13-cis-retinoic acid and low dose Ara-C in MDS as well as to establish "in vitro" advantage of retinoid dose-related growth pattern on bone marrow cultures as defined by culture timing and CFU-GM proliferative response. PATIENTS AND METHODS: We evaluated 28 patients diagnosed of MDS according to FAB classification, of whom 4 cases had RA, 8 cases SRA, 14 cases RAEB and 2 cases RAEB-T. Patients who had RA and SRA were treated with oral 13-cis-retinoic acid at doses of 20-40 mg daily for 4 months and those cases with RAEB and RAEB-T had subcutaneous Ara-C at doses of 3 mg/m2 twice a day for 21 days. The "in vivo" and "in vitro" effect of retinoic acid on the haemopoietic differentiation was evaluated by the growth CFU-GM in semisolid cell culture methods. RESULTS: Increasing in vitro concentrations of 13-cis retinoic acid did not enhance the growth of myelodysplastic progenitors. Nevertheless, our study did not find any beneficial therapeutic effect of retinoic compounds in MDS patients. In this study, low-dose Ara-C (3 mg/m2) showed similar effects when compared with higher doses reported by others. Furthermore, in terms of CFU-GM proliferation the concentration of colonies before and after treatment were fairly similar in all but two patients. CONCLUSIONS: The results drawn from our study demonstrated that there is no beneficial advantage of 13-cis-retinoic acid as a differentiation inducing agent on myelodysplastic patients. In contrast, lower doses of Ara-C showed similar effects on haemopoiesis of MDS patients than standard doses of 10-20 mg/m2 but with less side effects.

Blood Cell Count↗
PubMed1994

[Buruli ulcer in the Amansi West district, Ashanti Region, Ghana. The Cuban experience. I].

A study was made on 105 patients with Buruli ulcer in the Amansie West district, Ashanti Region, Ghana, representing 37.6% of the registered patients. The Tontokrom neighborhood showed the highest prevalence: 84 x 1,000 inhabitants. Predominance of females (54%) was observed. 74.8% did agricultural work and only 3 reported a previous trauma, predominantly with one lesion. Household contacts were identified. Coverage with the BCG vaccine was low. It is concluded that there has been a real increase of the prevalence of Buruli in the region during the last years, especially among children and women. This has become a serious problem due to its invalidating and irreversible sequelae. Measures of control are proposed.

Adolescent↗
PubMed1993

Differential effects of haloperidol on negative symptoms in drug-naive schizophrenic patients: effects on plasma homovanillic acid.

After 5 weeks of haloperidol, positive symptoms in drug-naive schizophrenic patients substantially subsided. Negative symptoms, although with a different temporal pattern, decreased after the fifth week of haloperidol treatment; specifically, a decrease was seen in anhedonia and affective flattening, whereas avolition-apathy and attentional impairment presented no changes. Alogia showed a decrease during the third week and a trend to return to placebo scores during weeks 4 and 5. Changes in affective flattening, alogia and attentional impairment correlated with changes in positive symptoms. During placebo, plasma homovanillic acid (HVA) correlated with negative symptoms and with changes presented by negative symptoms between the first and the fifth treatment week. These data show that negative symptoms respond differentially to neuroleptics and suggest that avolition-apathy may represent a different behavioral component of the schizophrenia process.

Adolescent↗
PubMed1993

Evolutionary cytogenetics of the Drosophila buzzatii species complex.

The salivary gland chromosomes of 10 species in the Drosophila mulleri subgroup (repleta group) have been re-analysed. These include the eight members of the South American buzzatti and martensis clusters, previously ascribed to the mulleri complex, and the two Caribbean species D. stalkeri and D. richardsoni, previously comprising the stalkeri complex. The chief results can be summarized as follows. Inversion 3a is not present in the martensis cluster. Hence, there is no cytological link between this cluster, or the buzzatii cluster, and the rest of the mulleri complex. Accordingly, a new species complex, the buzzatii complex, is established with the two South American clusters. D. stalkeri and D. richardsoni share at least two inversions with all the species in the buzzatii and martensis clusters, and produce hybrids in interspecific crosses with many of them. This indicates a close phylogenetic relationship. Therefore, D. stalkeri and D. richardsoni are incorporated as a cluster within the newly erected buzzatii complex. A phylogenetic tree illustrating the chromosomal evolution of the buzzatii complex is presented and all the previous cytological information concerning its members is reviewed.

Animals↗
PubMed1993

Effects of epidermal growth factor in the final stages of nuclear and cytoplasmic oocyte maturation in humans.

Evidence has accumulated in mammals suggesting a positive role for epidermal growth factor (EGF) as an inducer of oocyte maturation. The potential use of EGF as inducer of cytoplasmic and nuclear maturation was tested in women with > 10 oocytes retrieved in in-vitro fertilization (IVF), since we have previously observed that such oocytes are immature. Oocytes from 17 high responders were randomly allocated to one of the three treatment groups upon retrieval: control receiving no EGF (n = 93), 1.0 ng/ml EGF (n = 92) and 10.0 ng/ml EGF (n = 77) for 6 h before insemination. The rates of fertilization were respectively 54.6, 59.0, and 46.1%, suggesting that EGF is not effective at this maturational stage after this length of exposure. Embryo development was further analysed by the appearance of the embryos under the dissecting microscope and the number of blastomeres developed 48 h after insemination. No difference between groups was observed considering the number of blastomeres developed. However, embryos derived from oocytes treated with 10 ng/ml EGF displayed a worse appearance under the microscope. It is concluded that a 6 h incubation with EGF does not seem to affect cytoplasmic maturation in oocytes obtained after gonadotrophin treatment, as ascertained by the rate of fertilization following oocyte insemination.

Blastomeres↗