The effect of autonomic arousal on attentional focus.

This study investigates the effect of arousal on visual selection processes. Arousal is predicted to narrow the window of attention surrounding a point of focus. BOLD response to a letter discrimination task was measured under aroused (aversive noise) and non-aroused conditions (n = 8). Results revealed spatially distinct responses for trials invoking a narrow versus wide attentional focus. Under arousal a wide focus showed posterior thalamic activation similar to that associated with the narrowed attentional focus. This reflects altered stimulus filtering and supported the hypothesis. Relevant neuroanatomy involving the locus coeruleus and a triangular circuit of selective attention is discussed. The data demonstrates the intersection of arousal and visual stimulus selection systems, identifies a cognitive consequence of arousal, and provides the first fMRI evidence for brain stem autonomic arousal.

Consenso Latinoamericano sobre infecciones en bronquitis crónica / Latin American consensus on infections in chronic bronchitis

Dos tercios de las exacerbaciones agudas de la bronquitis crónica (EABC) se asocian con infección bacteriana y se caracterizan por recrudecimiento súbito de la tos, disnea y aumento en el volumen y el aspecto purulento del esputo. Las infecciones bacterianas crónicas o recurrentes, inician y perpetúan un círculo vicioso de daño a las vías aéreas, que se produce mediante la estimulación persistente de la cascada inflamatoria por los productos bacterianos. De los microorganismos causales, el más común es H. influenzae. Otros patógenos frecuentes incluyen M. catarrhalis, la mayoría resistentes a aminopenicilinas y S. Pneumoniae, el cual ha incrementado recientemente a su resistencia a penicilinas y macrólidos a nivel orbital. Si bien algunos estudios recientes han demostrado de manera clara el beneficio del tratamiento antibiótico de los EABC, existen ciertas dudas relacionadas con la manera de clasificar la enfermedad y con los criterios utilizados para la inclusión y exclusión de los pacientes, que permitan esclarecer de manera definitiva el beneficio del antimicrobiano en cada uno de los grupos en los que se ha clasificado su severidad. Con el fin de lograr un consenso sobre algunas de estas variables y establecer lineamientos racionales que permitan abordar el tratamiento de estos pacientes, se reunieron recientemente (noviembre del 96 y marzo del 97) un grupo de destacados expertos latinoamericanos en infectología y neumología. El consenso identificó una serie de factores de riesgo que permitieron diseñar una clasificación de EABC que establece cuatro grados de severidad; estos a su vez están relacionados con un grupo específico de microorganismos que varían con las circunstancias y desde luego en la sensibilidad a los antibióticos. Asimismo el grupo de expertos estableció que la resistencia de los gérmenes que comúnmente afectan a estos enfermos (H. influenzae, S. pneumoniae y M. catarrhalis) requieren de antimicrobianos que sean activos contra más del 90 por ciento de las cepas causantes. Como lineamientos prácticos terapéuticos, se sugirió que la traqueobronquitis aguda (clase I) no requiere en general de antibióticos; que la amoxicilina permanece como el tratamiento de elección para las exacerbaciones leves (clase II), mientras que para la bronquitis crónica complicada (clase III), algunas fluoroquinolonas (p.ej.: ciprofloxacina), los nuevos macrólidos, combinaciones con inhibidores de betalactamasa o cefalosporina orales de 3º generación...

A multicenter study comparing intravenous meropenem with clindamycin plus gentamicin for the treatment of acute gynecologic and obstetric pelvic infections in hospitalized women.

We conducted a multicenter trial to compare the efficacy and safety of meropenem with the efficacy and safety of clindamycin plus gentamicin in the treatment of 515 hospitalized patients with acute gynecologic and obstetric pelvic infections. At the end of treatment, the rates of satisfactory clinical and bacteriologic response were high (88%) in both treatment groups: the rates of response were 90% for the meropenem group and 86% for the clindamycin/gentamicin group. No serious adverse events occurred. The most frequently reported drug-related adverse clinical events in the meropenem group were nausea and injection-site reactions (> 1% of patients), and the most common drug-related laboratory abnormality was thrombocythemia. Similar patterns of adverse events occurred in the clindamycin/gentamicin group; however, the incidence of diarrhea and eosinophilia was higher in this group. In summary, this trial demonstrated that meropenem is an effective and safe alternative to the combination of clindamycin plus gentamicin for the treatment of women with acute gynecologic and obstetric pelvic infections.

Ciprofloxacin versus gentamicin/clindamycin for postpartum endometritis.

An open, randomized, comparative study of intravenous ciprofloxacin versus gentamicin and clindamycin was performed on women with postpartum endometritis. Ciprofloxacin alone successfully eradicated the infections in 35 of 49 patients (71%), while the combination of gentamicin/clindamycin cured 41 of 48 (85%) (P = .15). The microbiology and antibiotic sensitivity of the endometrial isolates confirmed the poor activity of ciprofloxacin against anaerobic bacteria and less-than-optimal activity against Streptococcus faecalis. Ciprofloxacin, when used alone, may not be suitable for the treatment of postpartum endometritis.

Susceptibility of female pelvic pathogens to oral antibiotic agents in patients who develop postpartum endometritis.

Fifteen hundred patients were enrolled in a prospective, randomized study on the effect of antibiotic prophylaxis during cesarean section. Two hundred thirty-one patients developed postpartum endometritis, and the isolates obtained from the endometrium were tested for sensitivity to ampicillin, cefuroxime, ofloxacin, ciprofloxacin, and clindamycin. Minimum inhibitory concentrations of 50% and 90% of ampicillin, cefuroxime, and clindamycin were similar to previously reported values; however, slight differences were noted in the activity of the two quinolones to common pelvic isolates. The minimum inhibitory concentrations of 90% of ofloxacin and ciprofloxacin to 119 isolates of Enterococcus faecalis were 4.0 and 2.0, to 17 isolates of Staphylococcus aureus 1.0 and 0.5, to 39 isolates of Escherichia coli 0.5 and 1.0, to 46 isolates of Bacteroides bivius 4.0 and 8.0, to 57 isolates of Gardnerella vaginalis 1.0 and 2.0, to 71 isolates of Staphylococcus epidermidis 0.5 and 0.5, to 16 isolates of Proteus mirabilis 0.25 and 0.12, and to 50 isolates of Lactobacillus species 32.0 and 8.0 micrograms/ml, respectively. In summary, the quinolones have activity comparable with a variety of other oral agents versus female pelvic pathogens, with the quinolones ofloxacin and ciprofloxacin having better activity against most of the gram-negative isolates. Anaerobic activities were comparable with the beta-lactams, but inferior to clindamycin and metronidazole as expected.

Treatment of postpartum endometritis.

In this study, cefoxitin alone (2 gm, every 8 hours) was generally sufficient to cure postpartum endometritis, even when the patient had received prophylaxis with a beta-lactam antibiotic. When single-agent therapy fails, addition of ampicillin usually results in a prompt clinical response.

Randomized double-blind comparison of mezlocillin versus cefoxitin prophylaxis for vaginal hysterectomy.

One hundred patients undergoing vaginal hysterectomy were enrolled in a randomized double-blind comparative antibiotic prophylaxis study. Forty-six patients received mezlocillin and 54 patients received cefoxitin. No significant difference was found among patients who developed febrile morbidity. Failure rate for mezlocillin was 17 per cent and for cefoxitin, 15 per cent. There was an increase in colonization of Streptococcus faecalis and Enterobacter species in patients receiving three doses of cefoxitin prophylaxis.

Comparative efficacy and safety of mezlocillin, cefoxitin, and clindamycin plus gentamicin in postpartum endometritis.

The efficacy of mezlocillin versus cefoxitin versus clindamycin plus gentamicin was evaluated in 152 patients with postpartum endometritis. There were no statistically significant differences in rate of cure among the three groups (87% with mezlocillin, 82% with cefoxitin, and 92% with clindamycin-gentamicin). There were no severe adverse reactions observed in any of the three treatment regimens. Mezlocillin is as safe and effective as cefoxitin and clindamycin-gentamicin for treatment of postpartum endometritis.

A comparison of piperacillin, cephalothin and cefoxitin in the prevention of postoperative infections in patients undergoing vaginal hysterectomy.

A randomized, double-blind, multicenter trial was initiated to compare the safety and efficacy of piperacillin, cephalothin and cefoxitin in the prophylactic treatment of patients undergoing vaginal hysterectomy. The total dose of each antibiotic was 6 grams given in three equally divided doses. A satisfactory prophylactic response was obtained in 143 of 151 (95 per cent) patients treated with piperacillin, in 82 of 87 (94 per cent) patients treated with cephalothin and in 57 of 60 (95 per cent) patients treated with cefoxitin. The pooled data indicated that the piperacillin treatment group did not differ from the combined cephalosporin treatment groups with respect to prophylactic response, presence of febrile morbidity, fever index, duration of postoperative hospitalization and incidence of reported adverse experiences.

Piperacillin v Carbenicillin in the therapy for serious infections.

One hundred seven patients were treated with either piperacillin (56) or carbenicillin (51) in an open randomized trial of hospitalized patients with pleuropulmonary (40), urinary tract (26), gynecologic (21), skin and soft-tissue (eight), joint (five), bone (three), and miscellaneous other infections (four). Patients with urinary tract infections were given 150 mg/kg/day of piperacillin sodium or 200 mg/kg/day or carbenicillin sodium in divided doses every six hours intravenously. Patients with other infections were given 250 mg/kg/day of piperacillin sodium and 450 mg/kg/day of carbenicillin sodium; 53/56 (95%) patients treated with piperacillin and 45/51 (88%) patients treated with carbenicillin were cured clinically. In general, the drugs were well tolerated. There were, however, more adverse experiences in the groups taking carbenicillin. Of special interest was the finding of liver function test abnormalities in 17/78 (21%) carbenicillin recipients (evaluative and nonevaluative cases). We concluded that piperacillin was effective and safe. It has potential for use in a great variety of infections.

Moxalactam in the therapy of serious infections.

Sixty-seven patients were treated with moxalactam in a noncomparative trial of hospitalized patients; 32 had endometritis or chorioamnionitis, 12 had skin and soft tissue infections, 5 had osteomyelitis, 5 had pneumonia, 5 had urinary tract infections, 4 had arthritis, 2 had sepsis from an unknown source, 1 had endocarditis, and 1 had peritonitis. Bacteremia was present in 12 of these patients. Patients were given 3 to 12 g of moxalactam per day (mean, 6.24 g/day) in divided doses every 6 to 8 h. Seven patients were given intramuscular treatment for 3 to 20 days for part or all of their therapy. The rest were given intravenous treatment exclusively. Treatment was continued for 2 to 42 days (mean, 10 days). The dose and the duration of therapy were determined by the type of infection and the response of each patient. There were four treatment failures and one enterococcal-clostridial superinfection. Moxalactam was well tolerated. Allergic reactions led to the discontinuation of the antibiotic in three patients. Prolonged prothrombin and partial thromboplastin times were observed in 2 of 11 patients tested; in both instances in patients had severe underlying diseases, including malnutrition and alcoholism. Pain on intramuscular injection was noted in two patients receiving 1,500 mg, but not in five receiving a lower dose; in one case the pain forced the use of intravenous therapy after one dose, and in the other case the pain was mild and the patient was treated for 20 days. We concluded that moxalactam was effective in the treatment of the types of infections included in this study and produced few adverse reactions.