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Biomedical subjects

C Barros

Publications and source records attributed to C Barros.

At least 19 recordsLinked to original sources

[Non-Hodgkin's lymphomas associated with the acquired immunodeficiency syndrome. A multicenter clinical study of 77 cases].

BACKGROUND: The aim of the present was to study the prevalence of non Hodgkin's lymphoma (NHL) in AIDS patients as well as the clinicopathologic characteristics, response to treatment and survival. METHODS: From January 1984 to January 1991, 77 patients with NHL associated with AIDS diagnosed in 9 hospitals in Madrid were retrospectively studied. RESULTS: Ninety-two per cent of the patients were men (mean age 30 years: range: 9-66 years), 62% were intravenous drug abusers and 20 (26%) homosexuals. Pathologic study determined that 62 (80%) patients had high grade NHL (44% small noncleaved), 17% immunoblastic and 20% unclassifiable, and 15 (20%) had intermediate grade (16% diffuse large cell) being all the cases of the B immunophenotype. Sixty-five per cent were in advanced stages and 69% had B symptoms. Extranodal localizations were present in 88%, bone marrow in 29% and CNS in 29%. Six cases had primary CNS lymphomas. 50% of the patients had less than 200 x 10(6)/l CD4 lymphocytes. Forty-seven patients were evaluable for response to chemotherapy: 12 (26%) showed a complete response 27 (57%) a partial response and 8 (17%) did not respond. Opportunistic infections developed in 18%. The estimated survival at 3 years was 14% (median 6 months). On univariate analysis the parameters related to the worst survival were: primary CNS lymphoma, liver involvement, lack of treatment response, LDH > or = 300 UI/l, alkaline phosphatase > or = 500 UI/l and ESR > or = 70 mm. CONCLUSIONS: Non Hodgkin's lymphomas associated with AIDS usually behave in an "aggressive" way with a high frequency of advanced stages, B symptoms, high grade histologic subtypes and extranodal involvement. Response to treatment is poor, bone marrow toxicity frequent and survival short.

Adolescent

Immunodetection of acrosin during the acrosome reaction of hamster, guinea-pig and human spermatozoa.

Mammalian sperm acrosomes contain a trypsin-like protease called acrosin which causes limited and specific hydrolysis of the extracellular matrix of the mammalian egg, the zona pellucida. Acrosin was localized on hamster, guinea-pig and human sperm using monoclonal and polyclonal antibodies to human acrosin labelled with colloidal gold. This was visualized directly with transmission electron microscopy, and with light and scanning microscopy after silver enhancement of the colloidal gold probe. Four distinct labelling patterns were found during capacitation and the acrosome reaction in hamster and guinea-pig spermatozoa, and three patterns were found in human spermatozoa. In the hamster, acrosin was not detected on the inner acrosomal surface after the completion of the acrosome reaction, thus correlating with the observation that hamster spermatozoa lose the ability to penetrate the zona after the acrosome reaction. With guinea-pig and human spermatozoa, acrosin was still detected after the completion of the acrosome reaction, thus correlating with the observation that acrosome reacted guinea-pig spermatozoa bind to and penetrate the zona pellucida.

Acrosin

[The results of a program of in vitro fertilization and tubal embryo transfer (ZIFT)].

Twenty-one sterile couples, between September 1989, and August 1991, were treated for ovulation stimulation of their cycles, in order to practice in them, a in vitro fertilization and tube embryo transfer (ZIFT). Two protocols of ovulation induction were used, both with leuprolide acetate (Lupron), one in the luteal phase and the other in follicular phase and since the second or the fourth day of the cycle, respectively, gonadotropins were added (Metrodine and Pergonal). Out of all the twenty-nine initiated cycles, twenty-seven were aspirated (93.1%) and twenty-four reached an embryo transfer (82.8%). Seven clinic pregnancies were obtained (29.17% per transfer) and four deliveries (16.67% per transfer). The sterility period average was 69.64 +/- 36.6 months and the patients age average was 34.1 +/- 4.38 years. The global rate of fertilization was 63.53%. With luteal phase Lupron best results were got (pregnancy rate of 38.46% per transfer) and there were not considerable difference in the number of gonadotropins ampulla employed. When embryos were transfer to the tubes and the uteri the pregnant rate was 50% per transfer, in comparison to 18.75% when transfer was made only in the tubes.

Chile

Golden hamster perivitelline spermatozoa do not show proacrosin/acrosin at the inner acrosomal membrane.

It has been suggested that acrosin may function in penetration of the zona pellucida and of the highly structured extracellular matrix of the perivitelline space. In this study we investigated whether golden hamster perivitelline spermatozoa contain proacrosin/acrosin, as evidenced by the silver enhanced immunogold technique using the monoclonal antibody antiacrosin C2E5. None of the 197 spermatozoa recovered from the perivitelline space showed proacrosin/acrosin associated with the acrosomal region, suggesting that acrosin would not play a role in the penetration of the perivitelline extracellular matrix.

Acrosin

[Anisakiasis in Spain. Report of 3 cases].

We reported here three cases of non-imported anisakiasis in Spanish patients. Eating raw sardines was the only common epidemiological feature. Two of the cases presented clinically as a bowel obstruction, and underwent an emergency surgical procedure. In the intestinal biopsy a larva of Anisakiasis simplex was found in the abdominal wall, surrounded by a eosinophilic granuloma and large edema. The third case presented as a peptic ulcer disease with longer evolution time, and a larva of Pseudoterranova decipiens (Phocanema) was found during an upper gastrointestinal endoscopic procedure.

Adult

[Renal fungal infection: presentation forms and therapeutic advances].

Fluconazole is a broad spectrum anti-fungal agent which combines good tolerance, efficacy and low toxicity, and offers useful advantages in the treatment of certain forms of mycosis. Three cases of renal fungal disease treated with surgery (nephrectomy in two cases and pyelolitectomy plus partial nephrectomy in the third one) and fluconazole or amphotericin B are presented. In all three cases there was at least one predisposing factor (diabetes, urolithiasis, urinary catheter, previous therapy with antibiotics, or AIDS), and the causing pathogens were Candida and Mucor. Administration of fluconazole 100 mg b.i.d. for 4 weeks in the two candida infected patients accomplished a complete cure of the disease. Incidence, etiopathology, presentation forms and diagnostic techniques of urinary mycosis are analyzed together with the current therapeutical options, making special reference to fluconazole.

Adult

Localization of microfilaments and a tubulin-like protein in crustacean (Rhynchocinetes typus) spermatozoon.

Sperm from the decapod crustacean Rhynchocinetes typus undergo dramatic shape changes as they pass from the vas deferens to seawater and interact with the oocyte envelopes. Using FITC-phalloidin and antitubulin antibodies, we were able to localize microfilaments and a tubulin-like protein in R. typus spermatozoon. Microfilaments and the tubulin-like protein were associated with the sperm rays and spines, but were absent at the spike and at its base. Folded and unfolded spermatozoa display similar fluorescence patterns. SDS-PAGE of whole spermatozoa and electrotransfer to nitrocellulose confirmed the presence of actin and two proteins at 97 kd and 120 kd that bind to tubulin antibodies (tubulin-like proteins). These results demonstrate the presence of actin, but not tubulin, and localize microfilaments in these sperm. It is proposed that this cytoskeletal component is active in sperm during crustacean fertilization.

Actin Cytoskeleton

Human spermatozoa selected by Percoll gradient or swim-up are equally capable of binding to the human zona pellucida and undergoing the acrosome reaction.

Several techniques have been used for selecting motile spermatozoa including Percoll and albumin gradients, swim-up, and glass wool filtration. A high yield of motile spermatozoa as well as an enhancement of motility are the most desirable features of a practical method. An equally important consideration is whether or not these techniques select functionally normal spermatozoa. In this study we have compared two methods for separation of motile cells, swim-up and Percoll gradient. Normal semen samples from 12 different men were used in this study. Each sample was simultaneously processed by swim-up and Percoll gradient using modified Tyrode's medium. After the sperm concentration was adjusted to 1 x 10(7) spermatozoa/ml, the suspensions were incubated at 37 degrees C, 5% CO2 in air. In each suspension the percentage of sperm recovery, percentage of motile spermatozoa, percentage of acrosome reacted spermatozoa (either spontaneously or stimulated with human follicular fluid), percentage of zona-free hamster oocytes penetrated, and number of spermatozoa bound to the human zona pellucida were determined. The results obtained indicated that the percentage of sperm recovery was higher with the Percoll gradient than with the swim-up procedure (P less than 0.001). However, no significant differences were found between these two sperm populations in the percentage of motile cells, in the percentage of acrosome reacted spermatozoa, and in the percentage of zona-free hamster oocytes penetrated. In addition, the number of spermatozoa bound per zona pellucida was similar for spermatozoa selected by Percoll or swim-up. We conclude that there were no functional differences between the spermatozoa selected by either method.

Acrosome

Latent Haemophilus influenzae pneumonia in patients infected with HIV.

Pneumonia caused by common pyogenic bacteria occurs frequently in HIV-infected patients. Its clinical presentation has been described as being similar to that seen in non-immunosuppressed hosts but clearly different to that of opportunistic pneumonias. An atypical presentation has rarely been seen. In a 10-month period, we saw 12 HIV-infected patients who presented with Haemophilus influenzae pneumonia which was clinically and radiologically indistinguishable from Pneumocystis carinii pneumonia. Ten of the patients were intravenous drug users and were in different stages of HIV disease. The clinical picture was characterized by a prolonged course (median 4 weeks), non-productive cough, dyspnoea, and absence of findings usually present in bacterial pneumonia. Laboratory data frequently showed absence of leukocytosis, increased lactate dehydrogenase levels, hypoxaemia, and decreased CD4+ cell counts. All presented with interstitial or mixed bilateral infiltrates. Resistance to ampicillin and trimethoprim-sulphamethoxazole were each found in seven cases. Eleven patients were cured with antibiotic therapy, although five relapsed. H. influenzae pneumonia should be considered in HIV-infected patients who present with pulmonary symptoms and bilateral infiltrates of subacute or chronic onset. Clinical resolution of pneumonia is the usual outcome, but recurrences of infection are frequent.

Adult

[Splenic abscess: clinico-microbiologic study of 15 cases].

We have reviewed 15 cases of splenic abscesses diagnosed using a histopathological and microbiological study. Mean age was 48 years (range 18-78). Eight of them were male and 7 female. Eighty per cent of them had predisposing diseases, amongst which the most frequent were endocarditis and bacteriemia of other origin (26.6% in both cases). All patients presented fever and in 7 of them (47%) splenomegaly was appreciated. The most frequently isolated germs were gramnegative bacteria (33%), anaerobics (20%), and with a similar incidence grampositive bacteria, tuberculosis and fungii; in only one case cultures were sterile. Seven patients had multiple splenic abscesses and 8 patients single abscesses. Thorax x-ray showed alterations in more than half of the patients (53%). Abdominal echography was the diagnostic method in 67% of the patients and TAC in all the cases in which it was performed. Eight patients underwent splenectomy and one was surgically drained being the mortality rate of this group of 22%. Overall mortality was 33% and was related to the presence of multiple splenic abscesses (5/7, 71.4%), positive hemocultures (6/6, 100%), extrasplenic abscesses (7/8, 87.5%), and endocarditis (4/4, 100%), fungii infections (2/2, 100%), and late diagnosis (6/6, 100%).

Abscess

Effect of Test-yolk upon human sperm acrosome reaction.

Human spermatozoa stored in Test-yolk buffer show an increased rate of fusion with zona-free hamster oocytes as compared with freshly ejaculated spermatozoa. Therefore, in this work, we studied the kinetics of the acrosome reaction and fertilization using fresh and TEST-yolk stored human spermatozoa in order to determine whether the rate fertilization was related to the rate of acrosome reaction. The semen samples were divided in two aliquots, one was used fresh (control) and the other stored for 48 hours at 4 degrees C in TEST-yolk buffer (experimental). Spermatozoa of each aliquot were evaluated every two hours for: a) the incidence of acrosome reaction, as studied by scanning electron microscopy, and b) their ability to fuse with zona-free hamster oocytes. The results showed that--as a function of the incubation time--there was an increase in the percentage of acrosome reaction, both in controls (zero to 28.3%) and in the experimental ones (5 to 27.8). It was also found that there were no significant differences between the incidence of the acrosome reaction when using fresh or TEST-yolk treated spermatozoa. On the other hand the rate of fertilization was significantly (p < 0.05) higher when TEST-yolk stored (experimental) spermatozoa were used as compared with the use of fresh (control) spermatozoa. These results suggest that the increase in the rate of fertilization when using TEST-yolk stored spermatozoa is not associated with an increase in the rate of the acrosome reaction, but most probably to an improvement in the efficiency of the gamete membrane fusion.

Acrosome

Oxytocin and vasopressin binding sites in human and bovine ovaries.

Human ovarian tissue and bovine ovarian stroma and follicles bound tritiated oxytocin and tritiated arginine vasopressin with similar affinity, whereas bovine corpora lutea bound tritiated oxytocin only. Competition for the binding of tritiated oxytocin by various agonists and antagonists was suggestive of receptor function. The number of oxytocin binding sites varied cyclically in all tissues. In bovine ovarian stroma and corpora lutea the concentrations were lowest on day 14 and highest on days 17, 19, and 21 after ovulation, with a striking peak in the luteal concentration on day 19. In human ovarian tissues the concentrations also were highest in samples obtained in late luteal phase. In large follicles the concentration of oxytocin binding sites was highest on the day of estrus and lowest on day 7. In bovine ovary the number of arginine vasopressin binding sites was approximately 50% lower than oxytocin binding sites and the cyclic variations were not significant. Human ovarian tissue had similar numbers of oxytocin and arginine vasopressin binding sites. Because bovine ovaries produce oxytocin and arginine vasopressin the results suggest a paracrine or autocrine role for these neuropeptides in luteolysis and ovulation. Although their synthesis in human ovaries is still controversial the presence of binding sites suggests a physiologic role in the regulation of human ovarian function as well.

Analysis of Variance

Ceftriaxone monotherapy for severe bacteremic infections. Spanish Ceftriaxone Study Group.

We tested the efficacy of a single daily dose of ceftriaxone (active ingredient of Rocephin) for the treatment of severe bacteremic infections in 125 non-neutropenic adult patients. A single daily dose of ceftriaxone ranging from 1 to 4 g was given. Surgical procedures were performed if needed. Seventy-six (60.8%) were males and bacteremia was nosocomially acquired in 45 (36%). Microbiologically proven bacteremia was demonstrated in all patients. The most common microorganisms isolated were Escherichia coli (46 episodes), Streptococcus pneumoniae (17 episodes), Klebsiella pneumoniae, and Haemophilus influenzae, Serratia marcescens, Salmonella sp., and Staphylococcus aureus (9, 7, 6, 6, respectively). The urinary tract was the source of the bacteremia in 45 cases (36%), and the lower respiratory tract in 33 (26.4%). Mean duration of treatment was 10.8 days (range 3-21 days). One hundred and six patients (84.8%) recovered completely, 11 (8.8%) improved, but needed an alternative antibiotic treatment. An alternative treatment was also given to a patient whose condition had initially deteriorated. Seven patients (5.6%) died. Death was directly related to the infection in 2 cases. Three patients (2.4%) developed a superinfection, and 5 (4%) a severe (1 case) or mild (4 cases) adverse effect. In summary, a single daily dose of ceftriaxone proved to be useful for the treatment of selected severe bacteremic infections.

Adolescent

[In vitro fertilization program. Preliminary results].

Three infertile couples were submitted to in vitro fertilization and uterine embryo transfer (IVF+ET) and 7 to in vitro fertilization and pronuclear stage tubal transfer (IVF+PROST). In order to programmed menstruation Norethisterone, 10 mg daily, were administered during the cycle preceding the one of controlled ovarian hyperstimulation. In order to inhibit endogenous production of FSH and LH, leuprolide acetate, a Gn-RH agonist, was injected subcutaneously 1 mg daily during 6 days and 0.5 mg fowardly from the luteal phase of the cycle proceeding the one of hyperstimulation until the day of HCG administration. To achieve superovulation pure FSH (Metrodine), HMG (Pergonal) and HCG (Endocorion) were used. Oocyte retrieval was performed through transvaginal puncture under ultrasonographic control. For oocyte and embryo identification and classification, spermatozoa separation and capacitation and gamete insemination and incubation procedures habitual techniques were employed. Pronuclear embryo tubal transfer was performed through a laparoscope 17 hours after insemination and embryo transfer to the uterine cavity after 48 hours. Nine of 10 patients responded to gonadotrophin hyperstimulation and were submitted to ovarian puncture. 69 oocytes (7, per patient) were obtained, 59 (81.15% of which were mature. 74.55% of the inseminated oocytes fertilized. Two patients got pregnant: one, submitted to IVF+PROST, presently has a multiple pregnancy with triplets and the second, submitted to IVF+UT, had a missed abortion at 8 weeks of pregnancy.

Adult

[Bioassay of gamete membrane fusion: the past, present and future].

The gamete membrane fusion test, that uses zona-free hamster oocytes to evaluate the fertilizing ability of human spermatozoa, is being widely used in andrologic laboratories throughout the world. This test evaluates several steps of the reproductive process such as: a) sperm capacitation; b) acrosome reaction; c) gamete membrane fusion; d) sperm chromatin decondensation; e) chromosome condensation; f) egg activation as measured by the cortical granule breakdown and completion of meiosis. This test does not evaluates the sperm transit from the vagina to the site of fertilization nor the sperm passage through the human egg vestments. However, the sperm transit has been partly solved by the use of naturally occurring human cervical mucus to obtain seminal plasma free spermatozoa. This latter technique has greatly increased the diagnostic value of the gamete membrane fusion test. Notwithstanding, the results obtained with this test can vary considerably among the different laboratories, because of variations in the experimental design of the test. These differences can have an important effect upon the attitude the scientist and/or the physician might take in a given case of infertility. The parameters that vary most among the different laboratories are: a) obtention of seminal plasma-free spermatozoa; b) sperm concentrations; c) sperm preincubation time; d) type and concentration of serum albumin used. The original objective of this test was to evaluate the fertilizing ability of spermatozoa of men with problems of infertility. Nowadays is being also used for the assessment of male infertility agents and drugs that might affect the human reproductive function. The correlation found between the results of the gamete membrane fusion test with fertility has resulted in its use in testing the fertilizing ability of bovine and equine spermatozoa.

Acrosome

Aortic endocarditis caused by gentamicin-resistant Enterococcus faecalis.

A case is reported of a patient who developed aortic endocarditis after protracted hospitalization during which time the patient received multiple courses of aminoglycoside and cephalosporin therapy. The infecting organism, an Enterococcus faecalis strain, was resistant to gentamicin and to the combination of ampicillin with gentamicin. Valve replacement was performed after four weeks of therapy with ampicillin, and enterococci were isolated from cardiac vegetations. Valve replacement may be necessary to achieve cure of endocarditis due to enterococci highly resistant to gentamicin.

Aged