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Biomedical subjects

D Navarro

Publications and source records attributed to D Navarro.

69 records · Page 4Linked to original sources
PubMed1989

Monoclonal antibody characterization of progesterone receptors, estrogen receptors and the stress-responsive protein of 27 kDa (SRP27) in human uterine leiomyoma.

Uterine leiomyoma occurs in one of every four or five women during their reproductive life. Its origin is unknown but it is accepted that estrogens play a significant role in its development. In order to learn more about the estrogen dependency of leiomyoma, the biochemical and immunological properties of two markers of estrogen response in target cells (the progesterone receptor (PR) and the stress-responsive protein of 27 kDa (SRP27)) were studied in leiomyoma. The ER (estrogen receptor) and PR content were determined by conventional DCC exchange assays. Specific anti-ER, anti-PR and anti-SRP27 monoclonal antibodies were used in immunoblots and immunohistochemical (IHC) studies. The binding properties of PR from cytosol of leiomyoma showed a Kd of 0.8-1.3 nM, which is in the range described for other human tissues. 80% of all studied leiomyoma contained PR, in a range of 805-2000 fmol/mg protein. The Kd for leiomyoma ER was 0.1-0.9 nM, and 84% of the samples were positive for ER. The PR of leiomyoma has the two A and B forms of 120 and 94 kDa, as shown in the immunoblot using the AB52 anti-PR monoclonal antibody. The IHC study revealed that the PR is concentrated in the cell nuclei, in the form of perinuclear bodies, with a homogeneous staining pattern from cell to cell. The leiomyoma fibres contain SRP27 in a higher concentration than the healthy myometrium. The leiomyoma SRP27 shows a typical doublet of 24 kDa and 27 kDa in immunoblot, the same as in MCF-7 cells. The IHC study revealed a high degree of organization of SRP27 in leiomyoma cells, suggesting that this protein may be part of the cytoskeleton. The results obtained show that human leiomyomas contain ER, PR and RSP27 with similar immunological and biochemical properties to those of other human tissues, including the MCF-7 breast cancer cell line.

Adult↗
PubMed1989

Influence of premature rupture of membranes on induction of labor and plasma 13,14-dihydro-15-keto-prostaglandin F2 alpha and oxytocin levels in patients with unripe cervix.

Rupture of membranes at term, whether spontaneous or artificial, causes rapid and sustained increase in prostaglandin F2 alpha (PGF2 alpha) metabolite (PGFM) levels and is associated with augmentation of uterine contractions. To investigate why premature rupture of membranes (PROM) often fails to initiate uterine contractions, we measured plasma concentrations of PGFM and oxytocin (OT) in patients with PROM near term. Serial blood samples were taken before and after PROM as well as before and after local PGE2 gel application for cervical ripening. For comparison, patients with similar criteria with intact membranes were also studied, as were patients in spontaneous labor at term with and without spontaneous rupture of membranes. PROM was always associated with an initial, marked increase in plasma PGFM. Whether or not this increased PGF2 alpha production was maintained was related to the cervical status at the time of PROM. In patients with unripe cervix PGFM levels returned to initial levels within 2 hours and no contractions were elicited; when the cervix was 3 cm or more dilated, PGFM levels remained high and contractions began within 1 to 3 hours. PROM had no significant effect on plasma OT levels. When PGE2 gel was applied to ripen the cervix, PGFM levels increased moderately within 30 minutes in all patients regardless of the status of the membranes. In patients with intact membranes the concentration of PGFM in plasma declined to initial levels within 4 hours, whereas in patients with PROM, PGFM levels remained increased throughout the study period.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Autoradiographic comparison of thallium-201 diethyldithiocarbamate, isopropyliodoamphetamine and iodoantipyrine as cerebral blood flow tracers.

We investigated [201Tl]diethyldithiocarbamate (DDC) as a tracer for local cerebral blood flow (LCBF). Awake male rats were given intravenous infusions of a mixture of DDC and reference tracer(s): [123I]isopropyliodoamphetamine (IMP) and/or [14C]iodoantipyrine (IAP). LCBF values for DDC, IMP, and IAP were measured using simultaneous multiple radionuclide autoradiography and quantitative digital image analysis. Patterns of local cerebral blood flow (LCBF) obtained with DDC were intermediate compared to IMP and IAP, although they were more similar to those of IMP. DDC and IMP underestimated LCBF in some white matter and adjacent structures, while IAP underestimated LCBF values in high flow regions. We conclude that DDC uptake generally reflects local cerebral blood flow and that it can therefore be used as a cerebral perfusion tracer in humans using SPECT imaging.

Amphetamines↗
PubMed1983

Attention disturbance in Graves' disease.

Twenty-seven patients with untreated Graves' disease were studied in order to determine alterations of concentration/attention and their possible association with levels of T4, T3RU, free thyroxin index (FTI), and anxiety. The patients obtained significantly lower values (p less than 0.01) throughout the whole application period of the concentration/attention test in comparison with control healthy group. Multiple regression equations relating the attention indexes with levels of T4 and T3RU, FTI and anxiety in the patients were determined, and no significant relationships were found. Similarly, a non-linear regression equation relating attention index and FTI gave a non-significant result. Possible mechanisms that could explain the deficiency in concentration/attention in ths disease are discussed.

Adult↗
PubMed1982

[Diffuse gastric pseudolymphoma or reactive lymphoid hyperplasia (RLH). Apropos of a case].

The authors report a case of superficial diffuse gastric pseudolymphoma studied by double contrast examination induced by pharmacologic agents and full filling of the stomach after compressive manoeuvres. The authors emphasize the importance of this nosologic entity and the problems of differentials diagnosis with all the stages of gastric cancer, with the peptic ulcer, with the healed ulcer, with lymphomas, with erosive gastritis, with nodular benign lesions. The stress that the certitude of diagnosis is given only by the histologic examination.

Diagnosis, Differential↗
PubMedDate not supplied

Estrogen antagonism on T3 and growth hormone control of the liver microsomal low-affinity glucocorticoid binding site (LAGS).

Male rat liver microsomes contain a low-affinity glucocorticoid binding site (LAGS) capable of binding all natural glucocorticoids and progesterone with a Kd from 20 to 100 nM. The LAGS level is under endocrine control by T3, glucocorticoids and GH. These hormones act synergistically at physiological concentrations to increase the LAGS level. Since female rats show a LAGS level that is much lower than the males (0.15 vs 23 pmol/mg protein, respectively), here we investigated whether estradiol could decrease the LAGS in the male rat. Orchiectomized (OX) male rats showed a higher LAGS level than intact rats. This effect was reversed by implanting a Sylastic capsule containing testosterone. When the OX rats were implanted for 20 days with estrogen capsules that provided an estradiol level in serum of 40 pg/ml, their LAGS level decreased from 23 to 0.2 pmol/mg protein. This effect was not observed in intact male rats and can be partially reversed by testosterone implants into OX rats. Both hypophysectomized male rats and hypothyroid-orchiectomized male rats showed very low levels of LAGS. Administration of physiological doses of GH and/or T3 to these rats greatly increased their LAGS level (from 0.3 to 15 and 16 pmol/mg protein, respectively). Implantation of estrogen capsules to these rats two weeks prior to starting treatment completely inhibited the increase in the LAGS level in response to T3, and significantly decreased the response to hGH, and to a combination of hGH and T3. These results suggest that physiological estradiol levels can antagonize the LAGS induction by T3 and hGH in the male rat, and could be responsible for the low level of LAGS in the female rat. Moreover, estrogen capsules also inhibited the increase in the body and hepatic weights observed after hGH treatment, which suggests a powerful inhibitory effect of low estradiol levels on the male rat liver functions under regulation by T3 and/or GH.

Animals↗
PubMedDate not supplied

In vitro interaction between ofloxacin and cefotaxime against gram-positive and gram-negative bacteria involved in serious infections.

The checkerboard method was used to determine the antimicrobial activity of the combination cefotaxime/ofloxacin against 217 bacterial isolates involved in serious infections. Synergy or partial synergy was observed against 19 of 34 (55.8%) Staphylococcus aureus methicillin-susceptible isolates, 4 of 47 (8.4%) Streptococcus pneumoniae isolates, 28 of 34 (82.2%) Escherichia coli isolates and 70 of 102 (68.5%) Pseudomonas aeruginosa isolates. Antagonism was not observed with any of the isolates examined.

Anti-Infective Agents↗
PubMedDate not supplied

Meropenem permeation through the outer membrane of Pseudomonas aeruginosa can involve pathways other than the OprD porin channel.

The outer membrane protein (OMP) OprD is the major channel through which carbapenems permeate the outer membrane of Pseudomonas aeruginosa. In this study, we analyzed the OMP profiles of several P. aeruginosa clinical isolates showing diminished susceptibility to imipenem while remaining susceptible to meropenem. All these isolates lacked OprD or showed a reduced expression of this porin. Susceptibility to meropenem was thus independent of the level of OprD expression, indicating that the antimicrobial could be taken up via an alternative route. The level of expression of OprC (70 kD) was also unrelated to meropenem susceptibility. Nevertheless, OMPs OprF and OprE were expressed by all isolates, suggesting that in the absence of OprD, these porins might be involved in the permeation of meropenem.

Drug Resistance, Microbial↗
PubMedDate not supplied

Susceptibility of Pseudomonas aeruginosa isolates to ceftazidime is unrelated to the expression of the outer membrane protein OprC.

Previously, it has been postulated that the porin OprC facilitates the diffusion of ceftazidime through the outer membrane of Pseudomonas aeruginosa. To further investigate this claim, the outer membrane protein (OMP) profiles of 22 ceftazidime-susceptible clinical isolates were analyzed. No correlation was found between MIC values and the level of expression of OprC. Further, OprC was either undetectable or expressed in reduced amounts in 12 isolates. In contrast, OprF and OprE were present in all isolates studied. This study suggests that OprC is dispensable for the permeation of ceftazidime through the outer membrane of P. aeruginosa.

Bacterial Outer Membrane Proteins↗
PubMedDate not supplied

[Psychological characteristics of Cushing's syndrome].

Psychological state of 15 patients with Cushing's syndrome was studied, including 8 subjects with bilateral adrenocortical hyperplasia, 4 with adrenocortical adenoma, 2 with hypophyseal adenoma and 1 with adrenocortical cancer. The weakened intellect was noted in patients, suffering from adrenocortical hyperplasia. Low emotional stability, anxiety, suspiciousness and hesitation were characteristic of the patients under study. Psychic stability was lowered. A possible role of endogenous and exogenic factors of depression, as well as the conditions of hospitalization for such patients are discussed.

Adenoma↗
PubMedDate not supplied

[Activity of erythromycin and clarithromicin against isolates of Streptococcus pneumoniae with decreased sensitivity to penicillin obtained from healty carriers. Spanish Collaborative Group].

BACKGROUND: Empirical treatment of pneumococcal upper and lower respiratory infections must be chosen on the basis of the susceptibility patterns of nasopharyngeal colonizing strains isolated from healthy carriers. METHODS: The susceptibility to erythromycin and clarithromycin was investigated by a conventional microdilution method among 103 pneumococci isolates recovered from healthy children (n = 63) and adults (n = 40) exhibiting decreased susceptibility to penicillin (MIC > or = 0.12 mg/l). RESULTS: 63% of penicillin -resistant pediatric isolates were susceptible to erythromycin and 78.9% were susceptible to clarithromycin . Among isolates with diminished susceptibility to penicillin , 77.7% were susceptible to erythromycin and 86.3% to clarithromycin . 90% of adult isolates were susceptible to erythromycin and to clarithromycin . Overall, clarithromycin exhibited a better activity than erythromycin . CONCLUSIONS: Clarithromycin , and to a lesser extent erythromycin , are good alternatives to penicillin in the empirical treatment of respiratory tract infections caused by pneumococci with diminished susceptibility to penicillin .

Adolescent↗