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Biomedical subjects

R S Gibbs

Publications and source records attributed to R S Gibbs.

At least 55 records · Page 3Linked to original sources

The effects of pH and osmolality on bacterial growth in amniotic fluid in a laboratory model.

In studying the effects of amniotic fluid on bacterial growth in a laboratory model, we noted that the pH of the fluid appeared to exert an independent effect. This study was designed to test the ability to control the growth of Escherichia coli in amniotic fluid simply by controlling two important growth conditions, pH and osmolality. The effects of pH and osmolality on growth of E. coli were systematically studied in a standard media and in amniotic fluid. Optimal ranges in standard media were pH of 5.6 to 6.6 and osmolality of 150 to 215 mOsm. When the results of growth at 24 hours were corrected for pH by analysis of covariance, the presence of amniotic fluid or phosphate had no effect. We found pH to be the only variable predictive of bacterial growth in amniotic fluid in this laboratory model.

Amniotic Fluid↗

Life-threatening puerperal infection due to group A streptococci.

We describe two patients with life-threatening puerperal infection due to group A beta-hemolytic streptococcus. Each patient had bacteremia, shock, and multi-organ involvement. Both cases were compatible with a recently described streptococcal toxic shock-like illness. Both women failed to improve despite vigorous medical and antibiotic therapies, and each required hysterectomy. Obstetricians should be alert to the importance of early diagnosis and treatment of this potentially lethal infection.

Adult↗

A retrospective review of the efficacy and safety of prostaglandin E2 with premature rupture of the membranes at term.

OBJECTIVE: The purpose of this study was to assess rates of endometritis, clinical chorioamnionitis, cesarean delivery, and neonatal sepsis from the records of patients with premature rupture of the membranes (PROM) and an unfavorable cervix treated with vaginal prostaglandin (PG) E2 in comparison with those in the literature. METHODS: Using a computer data base at Denver General Hospital, we identified 146 women with PROM and cervical dilatation of 2 cm or less at term who were treated with PGE2 gel or suppositories. The records were reviewed to identify rates of maternal and neonatal infection and complications, as well as cesarean delivery. RESULTS: The cesarean rate was 12%. Chorioamnionitis developed in 6.8% of the study group and endometritis in 2%. Neonatal complications were limited to two with low Apgar scores (less than 7 at 5 minutes), one with microbiologically confirmed sepsis, and two with positive urine counterimmunoelectrophoresis for group B streptococcus. The only instance of neonatal sepsis occurred in a patient with rupture of membranes longer than 24 hours. CONCLUSIONS: The use of vaginal PGE2 suppositories for induction of labor and cervical ripening in term patients with PROM was accompanied by a high rate of vaginal delivery and a low rate of maternal and neonatal complications in a city hospital setting.

Administration, Intravaginal↗

A rabbit model for bacterially induced preterm pregnancy loss: intervention studies with ampicillin-sulbactam.

We conducted experiments with a previously described rabbit model of Escherichia coli-induced preterm pregnancy loss. Does at 70% gestation were inoculated hysteroscopically with 0.2 ml of Escherichia coli (10(5) colony-forming units per milliliter) or saline solution. Animals were randomly assigned to either receive treatment with ampicillin-sulbactam (begun 1 to 2 hours before inoculation and continued for up to 7 days) or to receive no therapy. Animals were killed after delivery or after 7 days. Saline solution-inoculated animals had no pregnancy loss. Of the Escherichia coli-inoculated animals, those treated with ampicillin-sulbactam had significantly fewer deliveries, fewer positive cultures, and more live fetuses than the untreated animals (p less than or equal to 0.001). Cultures from multiple sites, amniotic fluid prostaglandin levels, and maternal progesterone levels were obtained, and the placenta, uterus, and fetal lung were histologically evaluated. In the second phase of the study, the Escherichia coli-inoculated animals were treated with ampicillin-sulbactam at one of three times: at inoculation or 2 or 4 hours after inoculation. The Escherichia coli-inoculated does treated with ampicillin-sulbactam at or before inoculation had significantly fewer deliveries, fewer positive cultures, and more live fetuses than the Escherichia coli-inoculated does in which treatment was delayed 4 hours (p less than or equal to 0.01).

Ampicillin↗

A randomized placebo-controlled trial of erythromycin for the treatment of Ureaplasma urealyticum to prevent premature delivery. The Vaginal Infections and Prematurity Study Group.

Ureaplasma urealyticum has been associated with low birth weight and histologic chorioamnionitis and it is a frequent isolate from the chorioamnion of patients who are delivered prematurely. In prior clinical trials using antibiotics active against U. urealyticum, antibiotic treatment was associated with reduced prematurity and increased mean birth weight. In this multicenter, randomized, double-blind clinical trial, pregnant women with U. urealyticum were treated with 333 mg of erythromycin base or placebo three times daily, starting between 26 and 30 weeks' gestation and continuing through 35 completed weeks of pregnancy. Women with urinary tract infection or Neisseria gonorrhoeae infection were excluded from the trial, and women with Chlamydia trachomatis or group B streptococci were excluded from these analyses. Erythromycin did not eliminate U. urealyticum from the lower genital tract. There were no significant differences between erythromycin- and placebo-treated women in infant birth weight or gestational age at delivery, in frequency of premature rupture of membranes, or in neonatal outcome.

Adult↗

Progress in pathogenesis and management of clinical intraamniotic infection.

In the past decade, gratifying progress has been achieved in our understanding of clinical intraamniotic infection. With a usual incidence of 1% to 4%, clinical intraamniotic infection mainly develops as an ascending process after prolonged rupture of the membranes and labor, but other cases may be hematogenous in origin whereas still others complicate intrauterine procedures. The most common organisms isolated in amniotic fluid of cases of intraamniotic infections are anaerobes, genital mycoplasmas, group B streptococci, and Escherichia coli. The latter two are found most commonly in maternal or neonatal bacteremia complicating intraamniotic infection. Although the diagnosis remains largely a clinical one, laboratory tests have been suggested to confirm the diagnosis in women with symptoms. These include amniotic fluid Gram stain, gas-liquid chromatography, and leukocyte esterase measurement. Maternal treatment consists of antibiotic therapy and delivery. Studies to date have used a penicillin plus an aminoglycoside, with some authors advocating the addition of clindamycin after cesarean delivery. Other broad-spectrum regimens may be equally effective. Complications of clinical intraamniotic infections include an increase in cesarean section rate and in maternal and neonatal bacteremia. Poor neonatal outcomes in intraamniotic infection are more likely in the following cases: (1) when E. coli or group B streptococci are present in the amniotic fluid; (2) when the infant has a low birth weight; (3) when maternal antibiotic therapy is delayed until after delivery.

Amniotic Fluid↗

A randomized, double-blind, placebo-controlled trial of oral antibiotic therapy following intravenous antibiotic therapy for postpartum endometritis.

One hundred thirty-six patients were enrolled in a randomized, double-blind, placebo-controlled trial of oral antibiotic therapy (amoxicillin) versus placebo following successful intravenous (IV) antibiotic therapy for postpartum endometritis. No subjects were readmitted to the hospital for recurrent endometritis and there were no wound infections or recurrent fevers. Minor side effects were seen in 10% of those taking amoxicillin and 14% of those taking placebo. Compliance was fair; only 52% of those taking amoxicillin and 65% of those taking placebo completed therapy. The lack of infectious complications in this high-risk population suggests that oral antibiotic therapy is unnecessary after successful IV antibiotic therapy for endometritis.

Administration, Oral↗

A rabbit model for bacteria-induced preterm pregnancy loss.

Bacterial infection has been implicated in premature labor in humans. To elucidate mechanisms and potential intervention strategies, we sought to develop a model of infection-induced pregnancy loss in rabbits. On day 21 (70% of gestation), each uterine horn was inoculated hysteroscopically with 0.2 ml containing saline solution of 10(6) cfu Escherichia coli or Bacteroides bivius or Fusobacterium necrophorum. Fetal viability was assessed. Animals were sacrificed at various times or as delivery occurred. Serum progesterone and amniotic fluid prostaglandins were measured. Cultures and histologic sections were prepared. Compared with the saline solution group, E coli and F. necrophorum-inoculated rabbits were significantly more likely to deliver (16 of 16 and six of seven with mean times of 31.9 +/- 10.7 and 28.3 +/- 11.5 hours, respectively for E. coli and F. necrophorum). Positive amniotic fluid cultures for the E. coli group were found in 11 of 12 (92%) and for the F. necrophorum group in three of three cases (100%). Histologic inflammation was seen heavily in both the E. coli and F. necrophorum groups, whereas it was absent in the saline solution group. Inoculation with B. bivius led to a much lower pregnancy loss rate (eight of 32) and less histologic inflammation despite positive uterine cultures in most animals. This model may provide an opportunity to determine mechanisms of clinical or subclinical intraamniotic infection and to test intervention strategies.

Abortion, Septic↗

Comparison of umbilical artery pH and 5-minute Apgar score in the low-birth-weight and very-low-birth-weight infant.

The division between "normal" and low Apgar scores is based largely on data obtained from term newborns and may not apply to the premature infant. Umbilical artery pH has been suggested as a better indicator of intrapartum asphyxia. We examined the charts of 558 infants with birth weights less than or equal to 2500 gm with respect to umbilical artery pH, 5-minute Apgar scores, and birth weight percentiles. A positive correlation between birth weight and 5-minute Apgar score was noted. No such relationship existed between birth weight and umbilical artery pH. Within birth weight groups, small-for-gestational-age infants have higher Apgar scores and lower umbilical artery pH values than their appropriate-for-gestational age counterparts.

Apgar Score↗

Risk factors for perinatal group B streptococcal disease after amniotic fluid colonization.

A group of 1031 parturient women at high risk for intraamniotic infection were studied. Women in whom group B streptococci grew from cultures of the amniotic fluid did not differ in clinical risk factors when compared with similar parturient women without group B streptococcal colonization of amniotic fluid. Patients who had perinatal group B streptococcal disease (maternal or neonatal bacteremia) did not differ from those without disease, by maternal or neonatal acute antibody levels or antibody response, inoculum size, or serotype of the colonizing strain.

Amniotic Fluid↗

Risk factors for preterm premature rupture of fetal membranes: a multicenter case-control study.

To assess the association between women with preterm premature rupture of membranes and 41 potential risk factors, we conducted a case-control study in six United States tertiary perinatal centers. The study involved completion of a comprehensive questionnaire for 341 women with preterm premature rupture of membranes in singleton pregnancies from 20 to 36 weeks' gestation and 253 control women matched for maternal age, gestational age, parity, clinic or private patient status, and previous vaginal or cesarean delivery. Univariate analysis revealed 11 variables associated with a significantly (p less than 0.05) increased risk of preterm premature rupture of membranes. After multiple logistic regression analysis, three variables remained in the model as independent risk factors: antepartum vaginal bleeding in more than one trimester (odds ratio 7.4; 95% confidence interval, 2.2, 25.6), current cigarette smoking (odds ratio, 2.1; 95% confidence interval, 1.4, 3.1), and previous preterm delivery (odds ratio, 2.5; 95% confidence interval, 1.4, 2.5). Cessation of cigarette smoking by pregnant women may reduce the risk of preterm premature rupture of membranes. Further study is necessary to determine the nature of the relationship between antepartum vaginal bleeding and preterm premature rupture of membranes.

Case-Control Studies↗

Protein banding patterns of the outer membrane-enriched fraction of Bacteroides bivius.

Bacteroides bivius is a common anaerobe in female genital infections. Although protein banding patterns of outer membrane (OM) preparations of Bacteroides fragilis are well described and are homologous within the species, similar work has not been done with B. bivius. Our aims were to (i) characterize the OM banding patterns of B. bivius and compare them with those of other Bacteroides species and (ii) test clinical isolates of B. bivius against anti-B. bivius and anti-B. fragilis sera to identify different serogroups that might also exhibit different OM banding patterns. OM-enriched fractions of 27 clinical strains of B. bivius, 6 Bacteroides disiens strains, 10 B. fragilis strains, and 12 other Bacteroides strains were prepared, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis was performed. Antisera to B. bivius ATCC 29303 and B. fragilis ATCC 25285 were raised in rabbits and tested against Bacteroides strains in an indirect enzyme-linked immunosorbent assay. All 27 B. bivius strains contained protein bands at 32, 27, 25, and 23 kilodaltons. This pattern was present in only 2 of 28 other strains; both of these were B. disiens. All B. bivius strains were reactive with the anti-B. bivius serum, while only 6 of 39 other strains (2 of 6 B. disiens) were reactive. Non-B. fragilis Bacteroides strains did not react with the anti-B. fragilis serum. Although there was marked homogeneity in the OM banding patterns of B. bivius, some B. disiens strains exhibited similar OM banding patterns. There appears to be some antigenic cross-reactivity between strains of B. bivius and B. disiens and very little with other Bacteroides species. These results may ultimately allow the development of rapid diagnostic tests for the B. bivius-B. disiens group.t

Bacterial Outer Membrane Proteins↗

A randomized comparison of gentamicin-clindamycin and cefoxitin-doxycycline in the treatment of acute pelvic inflammatory disease.

In this prospective trial, 130 hospitalized patients with acute pelvic inflammatory disease based on clinical criteria were randomly treated with intravenous gentamicin plus clindamycin (N = 63) or cefoxitin plus doxycycline (N = 67) for at least 4 days, followed by oral clindamycin or doxycycline, respectively, for a total of 14 days. Pre-treatment cultures were obtained for endocervical Neisseria gonorrhoeae and Chlamydia trachomatis, and for endometrial C trachomatis and aerobic and anaerobic bacteria. Overall, 46 subjects (35%) had endocervical cultures positive for N gonorrhoeae. Endocervical and endometrial cultures were positive for C trachomatis in 16 and 6%, respectively. Ninety-five percent of patients had at least one aerobic bacterium, 38% had at least one anaerobic bacterium, and only 2% had no organisms isolated from their endometrium. Fifty-seven subjects taking gentamicin-clindamycin (90.5%) and 64 subjects taking cefoxitin-doxycycline (95.5%) were clinically cured, a nonsignificant difference. Three subjects treated with gentamicin-clindamycin and one treated with cefoxitin-doxycycline required hysterectomy or salpingectomy for cure. Follow-up examinations and cultures were performed in 84% of the subjects. Post-treatment cultures for N gonorrhoeae were negative in all cases tested. Post-treatment endocervical and endometrial C trachomatis cultures were negative in ten of 11 subjects treated with gentamicin-clindamycin and in eight of nine treated with cefoxitin-doxycycline, a nonsignificant difference. We conclude that gentamicin-clindamycin and cefoxitin-doxycycline have similar clinical cure rates for acute pelvic inflammatory disease and are equivalent in eradicating genital N gonorrhoeae and C trachomatis.

Acute Disease↗

Reclosure of disrupted abdominal incisions.

We evaluated prospectively a technique of delayed reclosure of disrupted abdominal incisions. Forty-one consecutive postoperative obstetric and gynecologic patients with abdominal incisions that had opened because of infection, hematoma, or seroma and had intact fascia participated in the study. All wounds were first managed identically, with surgical drainage and debridement, for a minimum of 4 days. The patients then were randomized to either wound reclosure by a standardized en bloc technique (35) or healing by second intention (six). Reclosure was successful in 30 of 35 cases (85.7%). The mean time to complete healing was 15.8 days in successful cases, 67.2 days in failed cases, and 23.2 days for all patients who were reclosed. Failure to heal after reclosure was due to subcutaneous infection in two patients and seroma in three; these women were significantly heavier than those in whom reclosure was successful. There were no other major complications of wound reclosure. Patients randomized to healing by second intention required a mean of 71.8 days of wound care. The time to complete healing in the wound-reclosure group was significantly shorter compared with the group that healed by second intention (P = .002, log rank test). We conclude that en bloc reclosure of disrupted surgical incisions, compared with nonsurgical treatment, significantly decreases the time required for wound healing and has minimal morbidity.

Adult↗