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Biomedical subjects

E Navarro

Publications and source records attributed to E Navarro.

At least 19 recordsLinked to original sources
PubMed1994

Permanent dopaminergic alterations in the n. accumbens after prenatal stress.

It has been suggested that stress during the initial stages of human life may serve as a predisposing factor to mental illness. Recently, we reported that in pregnant rats, stress induces an increase of behavioral depression in the female offsprings when adult. This article describes the effect of prenatal stress on central dopaminergic transmission during adulthood. The offspring of stressed mothers showed an increase of behavioral depression in the Porsolt test and a reduction of DOPAC, HVA, and DOPAC/DA index in the n. accumbens. The effect on the right accumbens was more marked than on the left. A great body of information exists to suggest that depression is related to a decrease of dopaminergic neurotransmission, and the present data provide new evidence in support of the hypothesis that maternal stress during gestation increases the risk of depression in the offspring. We are also reporting a hitherto uncommented relationship between behavioral depression in the Porsolt test and the decrease of dopamine transmission in the n. accumbens.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1994

Diuretic action of an aqueous extract of Lepidium latifolium L.

An aqueous extract of Lepidium latifolium L. given orally and intraperitoneally considerably enhanced urinary excretion (UV) in rats with respect to control groups. A slight increase in ion excretion was also observed. Other parameters such as specific gravity, nitrite, pH, glucose, ketone bodies, urobilinogen, and blood were also studied. A good correlation for the dosage rat/man for the aqueous extract was achieved.

Administration, Oral↗
PubMed1994

Molecular phylogenetic analysis of Nitrobacter spp.

The phylogeny of bacteria belonging to the genus Nitrobacter was investigated by sequencing the whole 16S rRNA gene. The average level of similarity for the three Nitrobacter strains examined was high (99.2%), and the similarity level between Nitrobacter winogradskyi and Nitrobacter sp. strain LL, which represent two different genomic species, was even higher (99.6%). When all of the Nitrobacter strains and their phylogenetic neighbors Bradyrhizobium and Rhodopseudomonas species were considered, the average similarity level was 98.1%. When complete sequences were used, Nitrobacter hamburgensis clustered with the two other Nitrobacter strains, while this was not the case when partial sequences were used. The two Rhodopseudomonas palustris strains examined exhibited a low similarity level (97.6%) and were not clustered.

Base Sequence↗
PubMed1992

Immunoglobulin heavy-chain and CD3 delta-chain gene enhancers are DNase I-hypersensitive in hemopoietic progenitor cells.

Multipotential interleukin 3-dependent non-immortalized murine hemopoietic progenitor cells have DNase I-hypersensitive sites in the immunoglobulin heavy-chain and CD3 delta enhancers and transcribe germ-line T-cell antigen receptor gamma-chain (TCR gamma), but not IgM or TCR beta, genes. Induction of myeloid differentiation in these cells clones down expression and/or transcriptional accessibility of the immunoglobulin heavy-chain and TCR gamma genes. The CD3 delta enhancer region remains DNase I-hypersensitive but closes down in B cells. In embryonic stem cells and pan-mesodermal cells, these genes or enhancer regions are neither expressed nor DNase I-hypersensitive. These data suggest that lineage potential may be programmed, at least in part, by alterations in the accessibility or conformation of regulatory regions of genes and that some promiscuity of gene expression and/or accessibility can precede lineage commitment and maturation in progenitor cells induced to self-renew by interleukin 3.

Animals↗
PubMed1992

Multilineage phenotypes of interleukin-3-dependent progenitor cells.

Interleukin-3 (IL-3)-dependent murine FDCP-mix cells have multilineage differentiation capacity; they are nonleukemic, have a normal karyotype, and are nonimmortalized. These cells coexpress on their cell surface the "early" B-lineage marker B220/CD45R and the myeloid marker Mac-1/iC3b receptor (CR3), transcribe germline T-cell receptor gamma genes, and express the macrophage lineage growth factor receptor gene c-fms as a predominant 8.4-kb transcript. They do not detectably express at the stable mRNA or protein level other lymphoid precursor cell genes including CD2, TdT, lambda 5, and BP1. Induction of granulocyte/macrophage differentiation in these cells closes down expression of the lymphoid genes and activates stable expression of genes specific to the myeloid lineage, including myeloperoxidase. Expression of the c-fms gene at the mRNA level is upregulated and the dominant stable transcript is now in the 4.1-kb form typical of the macrophage lineage. These data provide a plausible explanation for the coexpression of lymphoid and myeloid lineage markers on human leukemic cells of stem cell or progenitor cell origin and have implications for the programming of lineage potential in normal multipotential hematopoiteic progenitor cells.

Animals↗
PubMed1992

Characterization of natural populations of Nitrobacter spp. using PCR/RFLP analysis of the ribosomal intergenic spacer.

DNA sequences from the intergenic spacer (IGS) region of the ribosomal operon were amplified by the polymerase chain reaction (PCR) technique using two primers derived from 16S and 23S rRNA conserved sequences. The PCR products, cleaved by 4 base cutting restriction enzymes, were used to differentiate Nitrobacter strains. This method offered a convenient alternative to serological testing for characterization of Nitrobacter isolates and enabled a large number of strains to be genotypically characterized easily and rapidly. This method was successfully used to characterize natural populations of Nitrobacter from various soils and a lake. A diversity was demonstrated in various soils, and in a lake both in freshwater and in sediments. Strains closely related to both WL and LL were found in these ecosystems. It seems that the diversity of Nitrobacter populations was not associated with global environments but may be related to the presence of locally coexisting niches.

Base Sequence↗
PubMed1992

Experimental Trichosporon infection in persistently granulocytopenic rabbits: implications for pathogenesis, diagnosis, and treatment of an emerging opportunistic mycosis.

Disseminated Trichosporon infection, an uncommon but emerging opportunistic mycosis due to Trichosporon beigelii, is frequently difficult to diagnose, refractory to treatment, and associated with a high attributable mortality. Models of disseminated and gastrointestinal Trichosporon infection were developed in persistently granulocytopenic rabbits. The patterns of infection resembled those of clinical disease, including cutaneous lesions, chorioretinitis, renal infection, pulmonary infection, and antigenemia cross-reactive with cryptococcal capsular polysaccharide. Antigenemia, an early manifestation of disseminated Trichosporon infection, originated in vivo from a fibrillar extracellular matrix. Trichosporon organisms disseminated from the gastrointestinal tract to visceral tissue in colonized immunosuppressed rabbits, whereas there was no dissemination from the gastrointestinal tract of otherwise normal rabbits. The antifungal triazoles, fluconazole and SCH 39304, were most active; maximum tolerated doses of amphotericin B and liposomal amphotericin B were ineffective. Trichosporon antigenemia declined in response to antifungal therapy. These findings contribute to improved understanding of the pathogenesis, diagnosis, and treatment of disseminated Trichosporon infection.

Agranulocytosis↗
PubMed1992

Conversion from pure 17,20-desmolase- to combined 17,20-desmolase/17 alpha-hydroxylase deficiency with age.

A previously described phenotypically female 46,XY-individual with 17,20-desmolase deficiency was followed from adolescence to adulthood. While at age 16.9 years her 17 alpha-hydroxylating capacity was normal and steroids not hydroxylated in position 17 low, decreasing 17 alpha-hydroxylated and increasing unhydroxylated steroids were observed thereafter up to the age of 25.2 years. Simultaneously with the steroid changes, previously normal blood pressure (110/80 mmHg) increased (180/130 mmHg). Since 17 alpha-hydroxylation and 17,20-desmolase activity are regulated by one cytochrome P450-17 alpha, it is concluded that, in this same patient, 17 alpha-hydroxylase activity was normal during childhood and adolescence, but decreased in the young adult. 17,20-desmolase activity, by contrast, was completely absent already in the fetus, causing absence of masculinization. The factors modulating this difference in cytochrome P450-17 alpha activity with age are as yet unknown.

Adrenal Hyperplasia, Congenital↗
PubMed1992

[Hodgkin's disease. Our 9-year experience with the 1980 protocol].

The purpose of this work was to evaluate the therapeutic results attained with our 1980 protocol for Hodgkin's disease. The usefulness of staging laparotomy was also analysed. Along a 9-year period, 94 patients were diagnosed (stages IA and IIA: 26 cases, IB, IIB and IIIA: 24 cases, and IIIB and IV: 44 cases). The complete remission (CR) rate, as a whole, was 85%; there were 14 relapses, of whom a new CR was attained in 9 instances. The overall actuarial survival is 64% at 47 months. The appearance of 3 cases of acute non-lymphoblastic leukaemia is noteworthy. Laparotomy induced changes of the patient's staging in 49% of cases (rise in 43% and descent in 6%). In account of this, laparotomy seems an adequate procedure in staging, although the criteria for selecting the patients who will undergo this, procedure should be perhaps restrictive.

Actuarial Analysis↗
PubMed1991

Pharmacological study of the muscle paralyzing activity of the juice of the banana trunk.

Extracts of the juice of the banana trunk were assayed in the isolated phrenic nerve-diaphragm muscle preparation of the rat. The chemical composition of those producing muscular paralysis was then studied. As active extracts mainly consisted of monopotassium oxalate, the effect of this compound on the muscle preparation was investigated and compared with that of the active extracts. The pattern of muscular paralysis induced by monopotassium oxalate was the same as that seen with the juice extracts. Likewise inhibition of contractions of the tibialis muscle was observed in vivo after intra-arterial administration of both the crude concentration of the juice and monopotassium oxalate. These findings suggest that monopotassium oxalate could be responsible for the muscular paralysis caused by the juice of banana trunk.

Animals↗
PubMed1991

Anti-Sm sera are misdetected by counterimmunoelectrophoresis. A critical analysis of CIE and western blotting on the detection of human antinuclear antibodies.

The ability of CIE and Western blotting to detect antibodies against the Sm, RNP and SS/B antigens was tested in 84 sera from SLE patients. CIE and Western blotting gave identical results for anti-RNP and anti-SS/B; positivity was detected in the same sera regardless of the technique used and no new positive sera were found by Western blotting among those classified by CIE as not showing immunological relationship to the anti-RNP and anti-SS/B references. CIE detected only half of the anti-Sm that were positive by Western blotting. The inability of CIE to detect sera positive for anti-Sm could not be ascribed to specific features of the sera, such as low titer or the lack of antibodies to the Sm antigens B/B' and/or D. The identity of a number of these new anti-Sm sera was confirmed by the utilization of an in vitro translation test, where the 'cell-free' translation products were immunoprecipitated with the new positive anti-Sm sera.

Antibodies, Antinuclear↗
PubMed1991

[Non-Hodgkin's lymphoma in childhood. Review of 33 cases].

A retrospective study was performed of 33 cases of non Hodgkin's lymphoma in children diagnosed in our hospital. The mean age was 10 years and there were 24 males and 9 females. The distribution, according to Rappaport's diagnostic classification, was: 11 undifferentiated lymphomas, 9 lymphoblastic lymphomas, 6 diffuse histiocytic lymphomas, and 7 cases of other types. Of the 33 patients, 23 had bulky disease (over 5 cm. in diameter). The mean serum LDH and uric acid values were, respectively, 537 (68-2021) and 6.0 (2.7-19). According to Murphy's staging system, the distribution of the cases was as follows: I (1), II (4), III (12), IV (16). Since this study spreads for a long period, several protocols have been used in the treatment of the group, but most patients received the LSA2-L2 regimen. Complete remission (CR) was achieved in 26 cases (78%), this being 100% of the lymphoblastic lymphomas. After a mean follow-up of 45 months, the actuarial survival is 48.1%, and the disease-free survival of patients attaining CR is 60.4%. The prognostic factors analysed, such as histologic type, stage, and serum LDH showed no statistical significance, probably due to the low number of cases studied.

Abdominal Neoplasms↗
PubMed1990

[Treatment of macroprolactinomas with delayed bromocriptine. Effectiveness of a single intramuscular injection].

The aim of the present study was to evaluate the effectiveness and tolerance of a new pharmaceutical preparation of long acting bromocryptine (bromocryptine depot of L.A.), characterized by the slow release of bromocryptine during 4 or 6 weeks after a deep intramuscular injection. It was administered to 9 patients with macroprolactinoma, 7 of which had visual abnormalities. The tolerance of the drug was excellent, and only one patient had nausea within the first 24 hours. In all cases, PRL values fell between 40% and 97%. All patients with visual abnormalities, including 2 patients with cranial nerve palsy (IIIth and VIIth pairs) returned to normal or improved. In the CT controls carried out after 4 weeks of therapy a reduction in tumor size was observed in 7 of 9 patients. Two patients were operated through the transesphenoidal route, PRL being demonstrated in the immunohistochemical study of the resected specimen. Subsequently, all patients received oral bromocryptine therapy with perfect tolerance. The results show that parenteral long acting bromocryptine is an effective, well tolerated and convenient way to start the therapy of macroprolactinoma, even when severe visual abnormalities are present.

Adolescent↗