[Vitamin D induces proliferation in rat endometrium cultured cells]

OBJECTIVE

To study the effects of 1,25-dihydroxyvitaminD3 (1,25-(OH)2D3) on proliferation and cell death in the rat uterus.

MATERIAL AND METHODS

A rat endometrial cell line (Rentro 1) grown in a Dulbecco Minimal Essential Medium (DMEM) supplemented with 1% charcoal stripped serum was used in all experiments in order to eliminate the steroid hormone. Cell monolayer was incubated in the presence and absence of 1,25-(OH)2D3 or 17 beta-estradiol or vehicle. After stimulation, we evaluated cell proliferation and DNA synthesis by trypan blue counting method and flow cytofluorometry, respectively. Finally, the genomic DNA integrity was evaluated by electrophoresis and the bands visualized with ultraviolet light.

RESULTS

The cells in medium containing 1% fetal bovine serum free of steroid hormones stimulated the cell growth 85% more than without serum. Supplement with albumin did not allow cell growth. The cells did not respond to 17 beta-estradiol but the presence of 1,25-(OH)2D3 induced cell proliferation. These results confirm that Rentro 1 cells do not express the estrogen receptor and demonstrate their capacity to respond to 1,25-(OH)2D3. Finally, the integrity of DNA was not affected by 1,25(OH)2D3, suggesting that this hormone is not involved in cell death by apoptosis in our cell line, as seen in other cell lines.

CONCLUSIONS

1) 1,25-dihydroxyvitamin D induced cell proliferation in the endometrial cell line Rentro 1 in a dose-dependent fashion and this effect is independent of the presence of an estrogenic stimulus; 2) the increase in cell number was related to DNA synthesis during the cell cycle; and 3) the presence of the hormone in the culture medium was not able to induce cell death.

[Chronic Chagas' disease: effects of treatment nn the levels of antibodies to crude and partially purified Trypanosoma cruzi antigens]

The specific therapy in Chagas' disease is useful in acute and neonatal infection and in children under three years old. The results of antiparasitic treatment during chronic infection are still controversial. It will be interesting to analyze the serological behavior in patients treated during chronic infection, to advance in the search of evolutive markers and markers of therapeutic efficacy. In the present work we have measured the antibody response by conventional serology and the response to partially purified T. cruzi antigens in chagasic patients who received nifurtimox or benznidazol 2 to 20 years before. The results showed that, by indirect immunofluorescence in 29% of treated patients the antibody levels were below the established cut off (1:32). By indirect hemagglutination 55% of treated patients showed this serological behavior. In this group a high number of discordant results was observed. By immunoenzimatic assay it was possible to detect a significative decrease of serologic reactivity to a partially purified acidic antigen (F IV) and to exoantigen of T. cruzi. It will be interesting to perform longitudinal surveys employing these antigens, to go further in the knowledge of possible immunological evolutive markers in Chagas' disease.

[Estrogen receptors and the mammary gland]

For several decades it has been known that steroid hormones, estrogen and progesterone, regulate some genes involved in the growth, proliferation and differentiation of the mammary-gland in animals and humans. In the last years, the presence or absence of the nuclear estrogen receptor has been used by clinicians as a marker for tumor malignancy, as a prognostic index or as an important parameter for hormonal therapy with anti-estrogenic compounds of some hormone-dependent breast cancers. This review shows some advances in the knowledge of the structure, function, molecular mechanisms of estrogenic activity, and interaction with proteins like protooncogenes and growth factors. Also, we refer to the role of the estrogen receptor in the physiophatology of breast cancer.

Prognostic significance of lymph node reactivity in the control of pathologic negative node squamous cell carcinomas of the oral cavity

BACKGROUND

Identification of high-risk patients and defining prognostic factors may be useful in the treatment of head and neck cancer. The role of the lymph node reactivity is still obscure. The value of the node reactivity pattern as a predictor of tumor control in oral cavity cancer was analyzed.

METHODS

Retrospective analysis of patients with oral cavity squamous cell carcinoma (OCSCC), submitted to tumor resection and neck dissection, with pathologic negative lymph nodes (pN0). Dominant node reactivity pattern was defined as lymphocytic predominance (LP), germinal centers (GC), normal (NL), sinus hystiocytosis (SH), and lymphocytic depletion (LD). Clinical and pathological characteristics of patients free of disease (DF) were compared with those of patients with control failure (CF), which included local, regional, and distant recurrences.

RESULTS

Of the 26 patients with pN0 OCSCC, prevalence of SH was found in 10 cases, GC in 13, and LD, NL and PL in 1 case each. Comparing CF and DF groups, there was no significant statistical difference regarding: age, gender, performance status index, weight loss, smoking and drinking habits, complementary treatment, average follow-up, tumor grade or thickness, margins, or tumor inflammatory and desmoplastic reaction. Although there was a higher proportion of perineural invasion and larger tumors in the CF group, the difference was not statistically significant either. Germinal centers or LP were noted in only 27% of the CF group and in 73% of the DF group. Collectively, NL, SH, or LD patterns were observed in 73% of CF. This incidence was statistically different from 27% of the DF group (P <0.05).

CONCLUSIONS

Lymph node reactivity pattern seems to be a prognostic index in pN0 OCSCC patients. Prospective analysis is advised to confirm these results. Prophylactic neck dissection as a staging procedure could select high-risk patients even when no metastasis is found.

Description of a project for the production and evaluation of oxygen-carrying hemosubstitutes

Scarce availability and risk of transmission of infections and diseases (HIV, hepatitis B, Chagas' disease) limit the use and benefits of homologous blood transfusions for surgical purposes. Recent trials of perfluorocarbon-based hemosubstitutes (PFC-HSs) in experimental cardiopulmonary bypass (CPB) have demonstrated their ability to improve brain oxygenation, as compared with conventional crystalloid priming solutions. The objective of the project described here is to test different formulations of PFC-HSs and optimize their formulation and dosage for use in CPB. The project includes: (1) study the feasibility of implementing a laboratory for small scale production of PFC-HSs; (2) evaluate the efficacy of use of PFC-HSs in an animal model of CPB; and (3) evaluate the safety of use of PFC-HSs in an animal model of hemorrhagic shock. Several in-house PFC-HSs and outside PFC-HSs are being evaluated. The current state of the project is: (1) the feasibility study has been completed and several PFCs, emulsifiers and surfactants are being tested; (2) and (3) the animal models have been implemented are being used to test in-house and outside PFC-HSs as priming solutions in CPB and reinfusion fluids in hemorrhagic shock respectively. Some preliminary results are presented.

[Silent ischemia]

The state of art in the treatment of silent myocardial ischemia is reviewed in such a way as to provide with the cardiologist information for the correct decision to be made in patients with ischemia, but without clinical symptoms of angina and its equivalents. Previewed-required, the concept, the classification and the diagnostic methods were reviewed. The prognosis, pharmacological treatment, intervention procedures and their results on the natural history of the disease are emphasised. It is recommended that the treatment of silent ischemia be done, at first, with primary and secondary prevention, and with pharmacological therapy. It is assumed that with the reduction of general ischemic episodes, survival can be individualized. New techniques have been introduced that modify the results in both the short and long term of these procedures.

[Intracardiac thrombosis in a patient with primary antiphospholipid syndrome. Report of a case]

Antiphospholipid antibody syndrome is characterized by arterial or venous thrombosis associated to the presence of antiphospholipid antibodies. We report a 32 atrial thrombus. Four months later, being with anticoagulant treatment, he had a deep venous thrombosis. A new echocardiogram did not show the atrial thrombus. The laboratory work-up confirmed an antiphospholipid syndrome. Five months later the patient has not presented new thrombotic episodes and is receiving oral anticoagulants and antiplatelet therapy.

[Multicenter comparative study of felodipine-ER and nifedipine-OROS in the treatment of mild-to-moderate arterial hypertension]

PURPOSE

To compare the efficacy and tolerance of felodipine-ER and nifedipine OROS, both once daily, in the treatment of mild-to-moderate uncomplicated arterial hypertension (AH).

METHODS

This was a multicentric, opened, randomized, paralled trial, that selected 121 patients with uncomplicated, mild to moderate essential AH (diastolic blood pressure (DBP) > or = 95 and < or = 110 mmHg; not under anti-hypertensive medication. All patients received placebo for two weeks. After that period, they would take either 5mg/day of felodipine, or 30mg/day of nifedipine OROS, both once daily, in a randomized fashion. Patients underwent laboratory tests and electrocardiogram (ECG) at the begining and at the end of the study, and heart rate and blood pressure (BP) measurements, nearly 24 hours after the last active drug dose.

RESULTS

Completed the study 111 patients, 60 in the felodipine group and 51 in the nifedipine group. Compared to baseline, the average of systolic BP and DBP decreased from 162.5 +/- 14.3mmHg and from 102.2 +/- 5.1mmHg to 143.3 +/- 14.6 and 87.9 +/- 7.2mmHg, respectively, at the end of the treatment in the felodipine group; and from 160.5 +/- 16.3mmHg and 102.5 +/- 6.2mmHg to 136.1 +/- 14.2 and 86.7 +/- 7.0mmHg, respectively in nifedipine group (p < 0.0001 for all diferences). Adequate BP response to the treatment (DBP normalization or reduction > 10mmHg from baseline) occured in 47/60 (78.3%) patients in the felodipine group and in 38/51 (74.5%) in the nifedipine group (NS). Side effects, occured in approximately 15% of the cases, and were similar in both groups. These were usually moderate and transient, but were responsible for the withdrawal from the study of two cases in the felodipine group and of three cases in the nifedipine group.

CONCLUSION

Felodipine-ER and nifedipine OROS, are similarly effective and generally well tolerated in patients with mild-to-moderate essential hypertension.

[Seronegative arthritis: reexamination of the initial diagnosis and prognosis after 10 years]

Seronegative arthritides are a heterogeneous group of diseases that includes rheumatoid arthritis with negative rheumatoid factor. Between 1980 and 1984 we studied 38 patients with seronegative arthritis. Thirty of these patients were reassessed in 1994 after 9 to 20 years of evolution. Seventeen patients had a diagnosis of seronegative rheumatoid arthritis; this diagnosis was maintained in 12, changed to seropositive rheumatoid arthritis in three, to psoriatic arthritis in one and connective tissue disease in one. Thirteen patients had a diagnosis of undifferentiated arthritis; in 1994 the diagnosis was maintained in three, seven patients were diagnosed as having a spondyloarthropathy, two as having a reactive arthritis and one as having a connective tissue disease. In 1994, nine patients fulfilled the 1991 criteria for spondyloarthritis and six of these did so on admission. Six of 12 patients with seronegative rheumatoid arthritis had an active disease or used antiinflammatory drugs and 64% had erosions on hand X ray examinations. These figures are in contrast with the enign evolution classically attributed to this disease and agree with recent reports. The usefulness of classification criteria for rheumatoid arthritis and spondyloarthritis in the initial assessment of patients with seronegative arthritis is emphasized.

[Adequacy of of pacemakers responsive to the volume-minute ventilation rate in heart transplantation patients]

PURPOSE

To evaluate in the late post-operative period (PO) the chronotropic response to exercise of patients submitted to orthotopic cardiac transplantation (CT) and the implant of a cardiac pacemaker (PM).

METHODS

A rate response ventricular PM (VVI+R) which uses minute ventilation (MV) as a sensor was implanted in five patients in the early PO of CT due to chronotropic incompetence. The patients were 31 to 64 years old and the indication to implant of PM was low ventricular escape rhythm following atrial taquicardia/bradycardia (one case) or sinus bradycardia (4 cases). The study was performed by means of paired exercise tests using Naughton protocol in order to compare the heart rate in VVI (prefixed heart rate) and VVIR+MV (rate response) mode. The duration of the exercise was compared between the two modes of stimulation.

RESULTS

In VVI mode the heart rate was significantly lower than in VVIR+MV mode for comparable periods of exercise (101 +/- 12 ppm vs 132 +/- 4 ppm; p < 0.05); in VVIR+MV mode the patients had a prolonged time of exercise as compared to VVI mode (15 +/- 7 min vs 12 +/- 7 min; NS).

CONCLUSION

The MV rate response PM provided patients with satisfactory heart during exercise and may be an adequate option to patients submitted to CT who present chronotropic incompetence.

Molecular mechanisms of the antihormonal and antiimplantation effects of norethisterone and its A-ring reduced metabolites

Norethisterone (NET) has been used as a contragestational postcoital agent. It is biotransformed to 5 alpha dihydro-NET (5 alpha-NET) and 3 beta,5 alpha tetrahydro-NET (3 beta,5 alpha-NET) in target tissues. The participation of these metabolites in NET effects is unknown. We have examined the antiimplantation and antiprogestational effects of NET and its metabolites, in adult mated female rabbits, by assessing the number of implantation sites and the expression products of the uteroglobin (UTG) gene in the uterus, and by comparing them with those of RU-486 and estradiol. Steroids were daily administered s.c. at several doses for 7 consecutive days, starting 24 hr after coitus. To assure that fertilization occurred in all animals, the presence of early pregnancy factor was determined. The results demonstrated that high doses (5 mg/kg) of NET reduced both implantation and the expression of the UTG gene. On the other hand, lower doses (1.5 mg/kg) of 5 alpha-NET produced an antiimplantation effect and suppressed UTG synthesis and its mRNA. These effects were similar to those of RU-486. At lower doses (1 mg/kg), both estradiol and the estrogenic metabolite 3 beta,5 alpha-NET were also effective in inhibiting implantation and UTG gene expression. The overall results suggest that NET metabolites exert antiimplantation and antiprogestational effects through their interaction with progesterone and estrogen receptors, and provide an explanation for the molecular mechanisms involved in the postcoital contraceptive action of NET.

Norethisterone metabolites modulate the uteroglobin and progesterone receptor gene expression in prepubertal rabbits

Norethisterone (NET) is a synthetic progestin, used as a contraceptive agent, that is biotransformed at target tissues into 5 alpha-NET and 3 beta,5 alpha-NET, which possess different pharmacological properties. The effects of these metabolites on the expression of uteroglobin (UG) and progesterone receptor (PR) genes, both regulated by progesterone (P4), were evaluated in the uterus of prepubertal female rabbits that were simultaneously treated with P4 (1.0 mg) for 5 consecutive days. As determined by Western and Northern blot analyses, 5 alpha-NET inhibited the P4-induced UG gene expression in a dose-dependent manner. A similar inhibition was observed with the administration of RU-486. The estrogenic agent 3 beta,5 alpha-NET and estradiol at a dose of 1.0 mg also inhibited the UG gene expression induced by P4. Both 5 alpha-NET and 3 beta,5 alpha-NET blocked the PR down-regulation induced by P4 as assessed by Western and Northern blot methods. The inhibition of UG synthesis and PR down-regulation by 5 alpha-NET and 3 beta,5 alpha-NET indicates that these NET metabolites possess antiprogestational properties.

Two distinct factors bind to the rabbit uteroglobin TATA-box region and are required for efficient transcription

The rabbit uteroglobin gene is expressed in a variety of epithelial cell types like the lung Clara cells and the glandular and luminal epithelial cells of the endometrium. Expression in Clara cells is on a high constitutive level, whereas expression in the rabbit endometrium is under tight hormonal control. One important element of the rabbit uteroglobin gene mediating its efficient transcription in two epithelial cell lines from human endometrium (Ishikawa) and lung (NCI-H441) is its noncanonical TATA box (TACA). Here, we show that two factors (TATA core factor [TCF] and TATA palindrome factor [TPF]) different from the TATA-box binding protein bind to the DNA major groove at two adjacent sites within the uteroglobin TATA-box region and that one of them (TCF) is specifically expressed in cell lines derived from uteroglobin-expressing tissues. The binding sites for TCF and TPF, respectively, are both required for efficient transcription in Ishikawa and NCI-H441 cells. Mutation of the TACA box, which we show is a poor TATA box in functional terms, to a canonical TATA motif does not affect TCF and TPF binding. Therefore, we suggest that the function of the unusual cytosine could be to reduce rabbit uteroglobin expression in cells lacking TCF and that the interaction of TATA-box binding protein with the weak TACA site is facilitated in TCF- and TPF-positive cells.

Characterization of multiresistant strains of Neisseria gonorrhoeae isolated in Nicaragua

The extensive use of antibiotics in Nicaragua raises concerns about the resulting levels of susceptibility of pathogenic bacteria. This is the first study that characterizes 18 strains of N. gonorrhoeae isolated in Nicaragua (1989), for their antibiotic susceptibility. Strains were predominantly of the auxotype/serotype Proto/PIB. There was no difference in lipopolysaccharides profiles obtained after SDS-PAGE for all strains. Variable expression of the PII outer membrane protein was not associated to antimicrobial resistance. All strains were susceptible to ceftriaxone, spectinomycin, rifampin and cefoxitin. The strains were classified in five groups based on plasmid profiles. A total of 78% of the isolates were penicillinase-producing (PPNG) and 22% were tetracycline-resistant N. gonorrhoeae (TRNG). One PPNG strain showed a concomitant decreased of penicillin binding to penicillin-binding protein 2. These randomly chosen isolates of N. gonorrhoeae from Nicaragua possess high levels of resistance to multiple families of drugs.

Endometrial expression of progesterone receptor and uteroglobin genes during early pregnancy in the rabbit

The progesterone receptor (PR) plays a pivotal role in the maturation process of the secretory endometrium, implantation and maintenance of pregnancy in rabbits. To determine the dynamics of PR gene expression and its physiological significance, the endometrial expression of PR and PR mRNA were evaluated and compared with the expression of the progesterone-regulated uteroglobin (UG) gene during 0-5 days post-coitus in rabbits. The results of immunoblot experiments indicated the presence of PR in endometrial cell extracts from days 1-4 of pregnancy with maximum PR immunostaining on day 2, followed by a marked diminution until its complete disappearance on day 5. When endometrial PR mRNA content was assessed by Northern blots, the results were similar to those of PR immunostaining, with maximal concentrations on the second day after mating. However, PR mRNA levels were still high on day 3, despite the concomitant decrease in immunostainable PR. Endometrial UG gene expression, on the other hand, exhibited a different time sequence. Thus, the UG content in uterine flushings progressively increased from day 3 after mating, reaching maximal levels on the fifth day. The endometrial UG mRNA content presented a similar profile, as its maximum concentration occurred on days 4-5. The overall results indicate that endometrial PR is down-regulated at both the mRNA and protein levels, possibly by endogenous progesterone during early pregnancy. The striking observation that maximal expression of endometrial UG gene products occurred when PR and its mRNA are no longer detectable suggests an important role for this progesterone-binding uterine protein during the preimplantation period.

Toxoid preparation from venom of Bothrops colombiensis (Central and South American snake)

A new technique is described for the preparation of Bothrops venom and their different fractions toxoid. This method preserves a high degree of immunogenicity but eliminates lethal effects. All the animals vaccinated with Bothrops crude venom toxoid survived when they were injected with crude venom.

[Evaluation of the use of amiodarone in outpatients]

From the group of patients follow-up at the arrhytmias out-patients clinic of the Institute of Cardiology from Rio Grande do Sul, Brasil, one hundred (100) patients were selected in order to evaluate the efficacy, benefits and side effects of short term use (minimum of 3 months) of amiodarone. During the period of study, the authors had found that average doses of amiodarone (200 mg/day) were highly effective for ventricular and supraventricular in addition, they also noticed a very low incidence of side-effects independent of the cardiopathy.

Calcium antagonists and heat-induced hepatic injury

Several laboratories have demonstrated the value of the isolated perfused rat liver as a suitable model for heat-induced hepatic injury in vivo. Membrane changes caused by perfusion of rat livers at 42 degrees C for 90 min were similar to those induced by toxic chemicals or hypoxia. In an evaluation of several categories of drugs reported to reduce cell injury, calcium antagonists (nifedipine, dantrolene, and verapamil), were evaluated for their therapeutic potential for heat injury. Isolated rat livers were perfused at 42 degrees C for 90 min with and without calcium antagonists. Livers were also perfused at 37 degrees C. Potassium and transaminase leakage, bile production and ultrastructure were used to evaluate their responses. Neither of the three calcium antagonists significantly improved any of the functional parameters measured. However, dantrolene produced dilated or vesicular rough endoplasmic reticulum in the heated livers. These changes suggest selective intracellular action on endoplasmic reticulum of heated livers. Ring-shaped mitochondria and vesicular endoplasmic reticulum were observed in the heated, verapamil-treated livers, but these could not be quantitatively distinguished from controls. Nifedipine did not appear to alter intracellular membranes, but did increase bile production.

Existence of ornamentations on macroconidia and hyphae of Epidermophyton floccosum

The surface features of cell walls of several recent clinical isolates of Epidermophyton floccosum were examined by scanning electron microscopy. Macroconidia from each of our isolates displayed excrescences on the wall which were similar in their location and in their substructural appearance. We believe these irregularities sufficiently developed to regard them as true wall ornamentations. Comparisons were made with wall features of the macroconidia of Microsporum persicolor. In some cases, our Epidermophyton isolates possessed warty as well as secondary smooth spiral hyphae. The demonstration of these structures in recent isolates might imply that some sexual activity persists so that discovery of a teleomorph(s) for the genus Epidermophyton may yet be forthcoming.

A familial pericentric inversion of chromosome 8 analysed with a high resolution chromosome banding technique

A familial pericentric inversion of chromosome 8 is described. The break points were localized by a high resolution chromosome banding technique and found to be inv(8)(p23.108q12.100). None of the family members had an unbalanced product of the inversion. There were no phenotypical abnormalities in the carriers. The break points and segregation pattern are compared with those of previously reported pericentric inversion of chromosome 8.

A girl with an interstitial deletion of the short arm of chromosome 3 studied with a high-resolution banding technique

A girl with delayed growth in body height and weight, retarded psychomotor development, facial dysmorphism, high-arched palate, extension defects of elbows, and a probable hearing impairment is presented. A chromosome investigation by both conventional and high-resolution banding techniques revealed an apparently pure interstitial deletion of the proximal segment of the short arm of chromosome 3 (46,XX,del(3) (p11p14.2) de novo). The paternal karyotype is 47,XYY. The clinical features of the patient are compared with those of two previously reported cases in the literature with an interstitial 3p deletion.