PubMed Health⌕ Search

Biomedical subjects

M Suarez

Publications and source records attributed to M Suarez.

At least 37 records · Page 2Linked to original sources
PubMed1993

4-Hydroxybenzoate uptake in Klebsiella pneumoniae is driven by electrical potential.

The uptake of 4-hydroxybenzoic acid (4-HBA) in intact cells of a mutant of Klebsiella pneumoniae was investigated. Uptake of 4-HBA was shown to be an inducible system. This uptake system, at pH 7.0, has a high affinity for its substrate (apparent Kt = 13 microM) and a maximal velocity of 27.6 nmol min-1 mg protein-1. Competition studies with various structural analogs indicated a very narrow specificity of the 4-HBA uptake system. The transport system has been inhibited by inhibitors of energy metabolism and its activity has not been detected in the crude shock extracts. The effect of two ionophores, nigericin and valinomycin, on 4-HBA uptake with respect to the external pH has been studied. All observations indicate that 4-HBA uptake is active and energized by the membrane potential.

Benzoates↗
PubMed1992

Trimethoprim-sulfamethoxazole versus pentamidine for Pneumocystis carinii pneumonia in AIDS patients: results of a large prospective randomized treatment trial.

OBJECTIVE: To compare the clinical efficacy and safety of trimethoprim-sulfamethoxazole (TMP-SMX) with pentamidine in the therapy of Pneumocystis carinii pneumonia (PCP) in patients with AIDS. PATIENTS, PARTICIPANTS: TMP-SMX (TMP, 20 mg/kg/day plus SMX, 100 mg/kg/day) was compared with pentamidine (4 mg/kg/day), both administered intravenously for 21 days in a prospective randomized treatment trial of 163 patients diagnosed with PCP between November 1984 and May 1988. RESULTS: Ninety-two evaluable patients received TMP-SMX as initial therapy; 68 received pentamidine. Failure to complete therapy was common. Of those receiving TMP-SMX, 39 (42%) required change in therapy because of failure to respond, and an additional 31 (34%) because of drug toxicity. This compared with 27 (40%; P = 0.733) and 17 (25%; P = 0.235), respectively, in the pentamidine-treated group. The overall survival rates were similar in the two groups, 62 out of 92 (67%) initially administered TMP-SMX versus 50 out of 68 (74%) initially administered pentamidine (P = 0.402). The survival rates for patients requiring a change in therapy because of failure to respond was 46% (18 out of 39) for the TMP-SMX group compared with 56% (15 out of 27) for the pentamidine group. When a change in therapy was made because of toxicity, survival rates were 97% (30 out of 31) for those receiving TMP-SMX versus 94% (16 out of 17) for those receiving pentamidine. CONCLUSION: TMP-SMX and pentamidine are of equivalent efficacy as initial therapies for PCP in patients with AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Reduction of primary posttraumatic adhesion formation with the prostacyclin analog iloprost in a rodent model.

Recent evidence suggests that inhibition of postsurgical adhesion formation may be effected by modulation of the activities of inflammatory cells contributing to mesothelial repair. Iloprost, a stable analog of prostacyclin, has been shown to exert vasodilatory, antiinflammatory, fibrinolytic, and antithrombotic influences. To determine whether these properties of iloprost might protect mesothelial surfaces from perioperative damage and hence prevent adhesion formation, we evaluated the effect of iloprost on peritoneal healing in a hamster model for primary pelvic injury. Perioperative iloprost therapy significantly reduced posttraumatic adhesion formation when compared with that in vehicle-treated controls. Dose-response studies demonstrate adhesion prevention with doses ranging from 0.04 to 4 mg/kg per 8 hours given subcutaneously over the course of 3 days. These data demonstrate that iloprost is a potent positive modulator of peritoneal healing after pelvic trauma. Further studies to characterize the potential application of iloprost as an adjuvant in reproductive surgery are indicated.

Animals↗
PubMed1991

Immunomodulation in the treatment of endometriosis-associated subfertility: use of pentoxifylline to reverse the inhibition of fertilization by surgically induced endometriosis in a rodent model.

OBJECTIVE: To determine the effect of pentoxifylline on early reproductive performance in an animal model for endometriosis. DESIGN: Preclinical blinded study in a rodent model. SETTING: Animal research laboratory. PARTICIPANTS: Sexually mature female golden hamsters. INTERVENTIONS: At laparotomy, groups of hamsters were subjected to: (1) excision of the right uterine horn and (2) excision of the right uterine horn with explantation of four 2-cm2 uterine fragments onto the left uterine mesentery. Six weeks later, surgically treated hamsters and nonsurgically treated controls were subjected to ovulation induction with pregnant mare serum gonadotropin and human chorionic gonadotropin; subsequently, hamsters were divided into groups for periovulatory treatment with either pentoxifylline (2.5 mg/kg) or vehicle given subcutaneously every 8 hours. All hamsters were mated with proven males and killed after 48 hours. MAIN OUTCOME MEASURES: Numbers of unfertilized oocytes and embryos recovered from the left uterine horn at 48 hours after mating. RESULTS: Fertilization rates in surgical and nonsurgical control groups exceeded 90%. Fertilization was significantly impaired in saline-treated animals bearing uterine explants (mean of 2.3% +/- 1.9%). Administration of pentoxifylline dramatically reversed this effect (99.0% +/- 0.7% mean fertilization rate). CONCLUSION: These data suggest that periovulatory treatment with pentoxifylline abrogated the adverse influence of endometrial explants on fertilization in the rodent model. Periovulatory administration of nonteratogenic immunomodulatory agents may provide an alternative to conventional treatment for endometriosis.

Adjuvants, Immunologic↗
PubMed1991

Periovulatory calcium channel blockade enhances reproductive performance in an animal model for endometriosis-associated subfertility.

Current evidence suggests that peritoneal inflammatory cell hyperactivation may be the essential pathologic abnormality in patients with endometriosis-associated subfertility. In these experiments we utilized an animal model to evaluate the use of an immunomodulatory agent as an alternative treatment for endometriosis-associated subfertility. The right uterine horn of 12 golden hamsters was resected and 2 x 2 mm squares were explanted onto the left uterine mesentery. Controls included hamsters undergoing uterine horn resection without endometrial explantation (n = 6) and nonsurgically treated animals (n = 6). Ovulation induction was initiated 6 weeks postoperatively with 40 IU of pregnant mare's serum gonadotropin on day 1 and 40 IU of human chorionic gonadotropin on day 3. Groups of six explant-bearing hamsters and six nonsurgical control hamsters were treated with verapamil (250 micrograms/kg every 8 hours subcutaneously), a calcium channel-blocking agent known to inhibit macrophage activation, from day 1 to 48 hours after administration of human chorionic gonadotropin. Animals were then killed and the number of embryos and oocytes in left tube counted as a reflection of reproductive performance. Fertilization was completely inhibited in animals bearing uterine explants. Treatment with verapamil dramatically reversed this effect. These data suggest that periovulatory treatment with an immunomodulatory agent such as verapamil may be an effective alternative to conventional treatment for endometriosis-associated subfertility.

Animals↗
PubMed1990

[Prevalence of herpetic infection in a female Chilean population].

The prevalence of the herpes simplex virus infection was investigated in a chilean female population. During 1981 and 1985 a number of 1,003 women were analyzed through serological methods. A 29.1% of the group referred past history of oral herpes and 59.4% of these presented 1 to 2 recurrent episodes a year. The high prevalence of this infection in our population is shown when detecting that a 91.4% of the female population had antiherpes simplex antibodies and the titer of this antibodies were in direct correlation to the antecent of recurrent clinical herpes and to the frequency of these episodes.

Adolescent↗
PubMed1989

Concurrent neuroborreliosis and Alzheimer's disease: analysis of the evidence.

Several recent reports have claimed a possible association between Borrelia burgdorferi infection and Alzheimer's disease (AD). Herein, we describe our search for additional evidence of neuroborreliosis in AD. Brain tissue from neuropathologically confirmed cases of AD was cultured for B burgdorferi using standard microbiologic methods. Material derived from culture was further examined using electron microscopy, direct immunofluorescence and acridine orange fluorescence. Previous studies have shown high titers of antiborrelia antibodies in CSF in all cases of confirmed neuroborreliosis; therefore, we tested CSF from neuropathologically confirmed cases of AD by indirect immunofluorescence and enzyme-linked immunoassay. In addition, imprint preparations from AD and control brain tissues were studied by direct immunofluorescence using a monoclonal antiborrelia antibody. Finally, a Western blot method was used to analyze protein extracts from cultures and AD brain tissue for the presence of borrelia antigen. Contrary to previous studies, our results do not support an association between infection with B burgdorferi and AD.

Alzheimer Disease↗
PubMed1989

Calibration of respiratory inductive plethysmograph during natural breathing.

We describe a single-posture method for deriving the proportionality constant (K) between rib cage (RC) and abdominal (AB) amplifiers of the respiratory inductive plethysmograph (RIP). Qualitative diagnostic calibration (QDC) is based on equations of the isovolume maneuver calibration (ISOCAL) and is carried out during a 5-min period of natural breathing without using mouthpiece or mask. In this situation, K approximates the ratio of standard deviations (SD) of the uncalibrated changes of AB-to-RC volume deflections. Validity of calibration was evaluated by 1) analyzing RIP waveforms during an isovolume maneuver and 2) comparing changes of tidal volume (VT) amplitude and functional residual capacity (FRC) level measured by spirometry (SP) with RIP values. Comparisons of VT(RIP) to VT(SP) were also obtained in a variety of postures during natural (uninstructed) preferential RC and AB breathing and with voluntary changes of VT amplitude and FRC level. VT(RIP)-to-VT(SP) comparisons were equal to or closer than published reports for single posture, ISOCAL, multiple- and linear-regression procedures. QDC of RIP in supine posture with comparisons to SP in that posture and others showed better accuracy in horizontal than upright postures.

Calibration↗
PubMed1988

Ictus emeticus induced by photic stimulation.

It has been recently established that ictus emeticus originates from mesial temporal lobe structures. We herein report a patient with generalized epilepsy who exhibited ictus emeticus reflexly triggered by intermittent photic stimulation accompanied by generalized photoparoxysmal responses on the electroencephalogram. All seizures and EEG abnormalities ceased after treatment with valproic acid. The occurrence of ictus emeticus in generalized epilepsy is an apparent paradox, better explained by the theory of "secondary temporalization" implying the selective engagement of temporal lobe structures during generalized seizures.

Electroencephalography↗
PubMed1988

Incidence of Chlamydia trachomatis in peripartum fallopian tubes.

We investigated the presence of Chlamydia trachomatis in fallopian tubes of patients undergoing Pomeroy tubal ligation in the immediate postpartum period with culture on cycloheximide-pretreated McCoy cells and with immunofluorescence staining. Two of 20 women were culture positive in both tubes, representing 10% culture positivity. Both patients were multiparous and black and reported no previous history of either pelvic inflammatory or sexually transmitted disease. Neither developed intrapartum or postpartum fever or any other signs of infection. These findings indicate that C trachomatis can be present in tubes of symptom-free pregnant women and not cause infectious morbidity either prepartum, intrapartum or postpartum.

Adult↗
PubMed1987

Human T-cell lymphotropic virus-III (HTLV-III) seropositivity and related disease among 71 consecutive patients in whom tuberculosis was diagnosed. A prospective study.

The incidence of tuberculosis has recently risen in Southeast Florida. In order to determine the number and proportion of tuberculosis cases and the characteristics of tuberculosis that might be related to human T-cell lymphotrophic virus-III (HTLV-III) infection, all patients seen by the Dade County Florida Public Health Department-Tuberculosis Clinic during a 6-month period were medically evaluated and screened for HTLV-III antibody by an enzyme-linked immunosorbent assay. Of 71 consecutive patients confirmed to have tuberculosis (70 by culture) during the study period, 22 (31%) were seropositive and 49 (69%) were seronegative for HTLV-III antibody. The seropositive group had a significantly higher proportion of patients who were black, Haitian, and within the age group of 25 to 44 yr. The seropositive group also had a significantly higher rate of mild-to-moderate serum aspartate transaminase elevations (less than or equal to 5 times normal), tuberculin skin test false negativity, extrapulmonary tuberculosis (especially lymphatic), and pulmonary tuberculosis with an atypical radiographic picture. The seropositive group had a significantly lower proportion of patients with sputum cultures positive for M. tuberculosis. There was no significant difference between the groups with respect to the proportion of patients with positive sputum smears when sputum cultures were positive, serious antituberculosis drug reactions (requiring discontinuation of therapy), or percent of home contacts who were tuberculin skin tested and found to be positive. At the time of the diagnosis of tuberculosis, only 6 (27%) of the seropositive patients with tuberculosis had clinical evidence of AIDS or AIDS-related complex (unexplained thrush).(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMed1987

Evaluation of a flexible fiberoptic catheter in confirming endotracheal tube placement in the intensive care unit.

UNLABELLED: We evaluated the use of an inexpensive 2.2-mm fiberoptic catheter (FOC) to assess endotracheal tube (ETT) placement in 22 critically ill adult patients. METHOD: The distance between the carina and the distal tip of the ETT was measured under direct visualization with the FOC and compared to the corresponding measurement obtained from concomitant chest radiographs. RESULTS: There was a significant linear correlation between measurements made by the two methods (r = 0.97, P less than 0.0001), and all FOC measurements were within 1 cm of the corresponding radiograph measurements. No complications or significant changes occurred in peak airway pressure, tidal volume, respiratory rate, or heart rate. The procedure usually was performed in less than 1 minute. Cost analysis revealed the possibility of major savings when the FOC is used instead of portable chest radiography. CONCLUSIONS: We conclude that documentation of endotracheal tube placement by means of a fiberoptic catheter is rapid, accurate, safe, and cost-effective.

Adult↗
PubMed1987

Chlamydia trachomatis attached to spermatozoa recovered from the peritoneal cavity of patients with salpingitis.

Five in a series of ten patients with laparoscopically demonstrated salpingitis had cultures positive for Chlamydia trachomatis obtained from tubal and peritoneal surfaces. Spermatozoa were observed in the peritoneal fluid of three of these patients, and two had cultures positive for C trachomatis. C trachomatis was attached to spermatozoa recovered from the peritoneal cavity in both patients. This observation suggests that spermatozoa may serve as vectors for C trachomatis and spread this pathogen to the peritoneal surfaces of the uterus and fallopian tubes.

Ascitic Fluid↗