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Biomedical subjects

R S Gibbs

Publications and source records attributed to R S Gibbs.

At least 73 records · Page 4Linked to original sources

Prevalence of asymptomatic hepatitis B infection in pregnant Mexican-American women.

Recent reports document high rates of asymptomatic hepatitis B virus infection in pregnant Hispanic women of Caribbean and Latin American origin, frequently in the absence of identifiable risk factors. We hypothesized that the prevalence of asymptomatic hepatitis B virus infection in Mexican-American women was much lower and that most belonged to established risk groups. Three thousand seven hundred eight-nine pregnant women, 77% of whom had Hispanic surnames, were screened for hepatitis B surface antigen upon admission in labor to Medical Center Hospital in San Antonio. Twelve women, six of whom had Hispanic surnames, were found to have asymptomatic hepatitis B infections. The prevalence of asymptomatic infections was 3.2 per 1000 (95% confidence interval 1.6-5.5) in the total population, 2.0 per 1000 (95% confidence interval 0.7-4.5) in those with Hispanic surnames, and 7.0 per 1000 (95% confidence interval 2.5-15.0) in those with non-Hispanic surnames. Risk factors, as defined by the Centers for Disease Control, were found in five (42%) of the positive patients overall and in only one (17%) of the positive patients with an Hispanic surname. We conclude that, although asymptomatic hepatitis B infection is uncommon in these pregnant Mexican-American women, the absence of identifiable risk factors in the majority of those infected suggests that routine screening in this population is justified.

Female↗

A clinical and microbiologic analysis of risk factors for puerperal endometritis.

Predictors of postpartum endometritis were identified in 607 asymptomatic, laboring women. One hundred (16.5%) developed postpartum endometritis. Multivariate analysis using stepwise logistic regression identified cesarean delivery (relative risk 12.8; P less than .0001) as the dominant overall predictor. In patients with cesarean delivery (N = 124), prophylactic antibiotics (relative risk 0.54; P less than .0002) and high-virulence bacteria or Mycoplasma hominis (relative risk 1.4; P less than .01) predicted the incidence of endometritis, and in patients with vaginal delivery (N = 483), "bacterial vaginosis organisms" (relative risk 14.2; P less than .001) and aerobic gram-negative rods (relative risk 4.2; P less than .01) predicted endometritis. Despite significant associations found on univariate analysis, clinical variables such as duration of labor, rupture of membranes, and internal monitoring were not predictive of endometritis in the multivariate analysis. Our findings show that cesarean delivery and certain organisms, such as bacterial vaginosis or high-virulence organisms, predict endometritis, and that clinical variables may be facilitators rather than predictors of endometritis.

Adult↗

Evidence relating bacterial vaginosis to intraamniotic infection.

We performed a two-part study to determine relationships of bacterial vaginosis and intraamniotic infection. In the first part of the study, we determined whether bacterial vaginosis organisms (Gardnerella vaginalis, Mycoplasma hominis, and anaerobes) were associated with each other in the amniotic fluid of 408 cases of intraamniotic infection. In the second part, we determined the association of bacterial vaginosis itself with intraamniotic infection in 125 cases at high risk for intraamniotic infection. Strong associations were observed among the bacterial vaginosis organisms in amniotic fluid (p less than 0.01 to p less than 0.001). Women with bacterial vaginosis were more likely to develop intraamniotic infection than those without bacterial vaginosis (69% vs. 46%, p = 0.03). Women with bacterial vaginosis were more likely to have G. vaginalis and M. hominis in the amniotic fluid (p less than 0.01 and 0.04, respectively). These observations implicate bacterial vaginosis as a cause of intraamniotic infection.

Adult↗

Severe infections in pregnancy.

Although genital and wound infections are not uncommon in the puerperal patient, these cases often resolve with appropriate medical therapy-usually a rational program of antibiotics and supportive therapy. In the severely ill obstetric patient, however, surgical intervention may be the only choice of management.

Cesarean Section↗

Transmission of genital mycoplasmas from mother to neonate in women with prolonged membrane rupture.

Colonization of the neonate with genital mycoplasmas occurs during passage through a colonized birth canal or in utero via contamination of the amniotic fluid. To define further the route of transmission we obtained cultures from the maternal vagina, the amniotic fluid and the neonatal pharynx in 131 mother-baby pairs. Sixty-six percent (33 of 50) of the corresponding amniotic fluids were colonized when the vagina was colonized with Mycoplasma hominis. When the amniotic fluid contained M. hominis, 26% (9 of 34) of the neonates were colonized. Sixty percent (66 of 110) of the corresponding amniotic fluids were colonized when the vagina was colonized with Ureaplasma urealyticum. When the amniotic fluid contained U. urealyticum, 32% (22 of 69) of the neonates were colonized. No neonates were colonized with M. hominis without prior colonization of both the vagina and the amniotic fluid. We conclude that colonization of the amniotic fluid is an important intermediate step in colonization of the neonate with genital mycoplasmas.

Adolescent↗

Neonatal serologic response at term to the genital mycoplasmas.

Genital mycoplasmas are frequently found in the amniotic fluid (AF) of women with ruptured membranes but are infrequent pathogens in the neonates born to these women. The serologic response to the genital mycoplasmas, Mycoplasma hominis and Ureaplasma urealyticum, was studied in 35 mother-baby pairs following term deliveries. Amniotic fluid and neonatal surface cultures were obtained in all cases, as were maternal and neonatal acute and convalescent sera. Despite significant maternal serologic response, there was essentially no neonatal response. Mothers with M. hominis in the AF were significantly more likely than those with negative cultures for M. hominis to exhibit IgG seroconversion and had significantly greater changes in IgG concentrations. Their infants, however, did not exhibit a significant seroresponse regardless of the AF and neonatal culture results. There was also a significant maternal seroresponse to U. urealyticum. However, this did not correlate with the presence of U. urealyticum in the AF. Significantly fewer neonates exhibited a seroresponse to U. urealyticum, again with no relation to culture results.

Adolescent↗

Clinical comparison of single-oral-dose cefuroxime axetil and amoxicillin with probenecid for uncomplicated gonococcal infections in women.

Four hundred sixty-six female patients were enrolled in a randomized study that compared the clinical efficacies of single oral doses of cefuroxime axetil and amoxicillin with probenecid in the treatment of uncomplicated gonorrhea. Two hundred ninety-five patients had culture-positive gonococcal infections and completed the investigation. Cure rates for the patients treated with cefuroxime axetil and those treated with amoxicillin with probenecid were high (greater than 95%) for genitorectal infections. Pharyngeal infections, however, were not uniformly eradicated by either cefuroxime axetil (60%) or amoxicillin with probenecid (64%). Approximately 13% of each patient group suffered adverse events, which were gastrointestinal in the majority and were transient. Compared with amoxicillin plus probenecid, cefuroxime axetil in a single oral dose was an equally safe and effective drug for the treatment of uncomplicated gonorrhea in women caused by penicillin-susceptible strains.

Adolescent↗

A randomized, blinded, placebo-controlled trial of antibiotics in idiopathic preterm labor.

Because subclinical genital tract infection may play a major role in preterm birth, the efficacy of adjunctive antibiotic therapy in combination with standard parenteral tocolysis was examined in a randomized, blinded study of patients with idiopathic preterm labor. Labor was documented by three contractions in 20 minutes, cervical dilation of 1 cm or more, and the need for parenteral tocolysis. Enrollment was restricted to patients with intact membranes and without known causes for preterm labor. One hundred three patients at 24-34 weeks' gestation were randomized to intravenous ampicillin plus oral erythromycin or corresponding placebos. Compared with the placebo group, the adjunctive antibiotic group had a similar frequency of preterm birth (38 versus 44%), time to delivery (34 versus 34 days), birth weight (2847 versus 2855 g), and episodes of recurrent labor requiring parenteral tocolysis (0.43 versus 0.49). In our population, we found no benefit to the adjunctive use of ampicillin plus erythromycin. Significant differences in genital microflora between our patients and those of other studies may explain our results.

Adolescent↗

Previous intra-amniotic infection as a risk factor for subsequent peripartal uterine infections.

The risk of recurrent intra-amniotic infection was assessed in 76 women with a previous pregnancy complicated by intra-amniotic infection. Recurrent intra-amniotic infection occurred in five (6.6%), not significantly different from the incidence of 4.4% in a comparison population. When controlled by logistic regression for the increased cesarean section rate in the group with previous intra-amniotic infection, the incidence of endometritis was not significantly different between the groups. After eliminating nulliparas and patients who did not undergo labor, the incidence of intra-amniotic infection in patients with previous infections was not significantly increased over the comparison group. Those patients who did develop recurrent intra-amniotic infection had significantly longer labors (P less than .001), duration of ruptured membranes (P = .002), and duration of internal monitoring (P less than .001), and an increased number of vaginal examinations (P less than .001).

Adult↗

Logistic regression analysis of risk factors for intra-amniotic infection.

The identification of risk factors for intra-amniotic infection may allow changes in obstetric management and reduce complications. In a pilot study, stepwise logistic regression identified duration of ruptured membranes and duration of interval monitoring as significant risk factors for intra-amniotic infection. Using the preliminary regression equation, we established critical durations (risk criteria) to predict a 20% or greater probability of intra-amniotic infection. Subsequently, 2908 patients were screened prospectively for risk criteria and/or the presence of intra-amniotic infection. Seven hundred five patients of the 2908 (24%) met the risk criteria, and 107 of 124 cases of intra-amniotic infection (86%) met the risk criteria. In patients meeting the risk criteria, the relative risk of intra-amniotic infection was 19.7. In addition, 81 of 705 (12%) of mothers developed endometritis. Ten neonates of mothers with criteria developed sepsis or pneumonia. A stepwise logistic regression performed on the prospectively gathered data showed that among patients meeting risk criteria, parity, duration of internal monitoring, and duration of membrane rupture were the significant risk factors for intra-amniotic infection.

Adult↗

Multicenter clinical trials comparing cefotetan with moxalactam or cefoxitin as therapy for obstetric and gynecologic infections.

The clinical efficacy and safety of cefotetan was assessed in two multicenter clinical trials involving 335 evaluable patients hospitalized with obstetric and gynecologic infections. In Study I, cefotetan was compared with moxalactam and in Study II, cefotetan was compared with cefoxitin. The clinical response rate in Study I was 67 of 70 patients for cefotetan (96 percent) and 33 of 34 patients (97 percent) for moxalactam. In Study II, the clinical response rate was 138 of 147 patients in the cefotetan group (94 percent) and 76 of 84 patients in the cefoxitin group (91 percent). For the patients with bacteriologic response data, 196 of 205 cefotetan patients (96 percent), 23 of 24 moxalactam patients (96 percent), and 70 of 75 cefoxitin patients (93 percent) had a satisfactory bacteriologic response. Cefotetan was well tolerated and produced no major adverse reactions. The mean amount of cefotetan given was lower than that of moxalactam or cefoxitin.

Adult↗

Multicenter comparison of cefotetan and cefoxitin in the treatment of acute obstetric and gynecologic infections.

Two hundred eighty-seven women were treated in a multicenter, randomized, comparative study to compare the safety and efficacy of cefotetan every 12 hours with that of cefoxitin every 6 or 8 hours in the treatment of acute obstetric and gynecologic pelvic infections. The most frequent primary diagnoses in both groups were endometritis and pelvic inflammatory disease; 24 of these patients were also bacteremic. The mean duration of treatment was 5.2 and 5.4 days for the cefotetan and cefoxitin groups, respectively, and the total doses administered were 18.1 and 32.1 gm, respectively. The rate of clinical failure for the cefotetan group was 8.5% and 12.2% for the cefoxitin group. Laboratory and clinical adverse reactions were infrequent and none was serious; both antimicrobials were well tolerated. These results suggest the administration of cefotetan provided adequate clinical and bacteriologic effectiveness in the treatment of hospital- and community-acquired, polymicrobial obstetric and gynecologic pelvic infections.

Acute Disease↗

Antibodies to Chlamydia trachomatis and risk for tubal pregnancy.

We performed a case-control study of the effect of exposure to Chlamydia trachomatis on the risk for tubal pregnancy. Sixty women with tubal pregnancies and 60 matched control women with normal second-trimester intrauterine pregnancies were studied. Cases were more likely than controls to have detectable antichlamydial IgG antibodies (82% versus 58%, p less than 0.01) and their mean titers were higher. The prevalence of IgM antibody seropositivity was not different between cases and controls (20% versus 12%, not significant). Compared with women with IgG antibody titers of less than or equal to 1:8 the relative risk for tubal pregnancy for women with titers greater than or equal to 1:128 was 6.6 (95% confidence interval, 2.0 to 21.6). Among women with tubal pregnancies, antichlamydial antibody titers of greater than or equal to 1:128 were significantly associated with pelvic adhesions and inflammatory tubal mucosal damage. Only 17.6% of women with detectable antichlamydial antibody or inflammatory tubal damage reported a history of pelvic inflammatory disease or gonorrhea.

Adult↗

Intraamniotic infection in low-birth-weight infants.

Intraamniotic infection (IAI) complicating births of low-birth-weight infants (less than 2500 g) was compared with IAI in births of infants weighing greater than or equal to 2500 g for differences in neonatal and maternal infectious morbidity and mortality, as well as differences in microbiological isolates in amniotic fluid. Four hundred four cases of clinically diagnosed IAI were prospectively evaluated. Thirty-seven patients (9.2%) delivered neonates less than 2500 g, and 367 patients (90.8%) delivered neonates greater than or equal to 2500 g. The low-birth-weight group had a significant increase in the incidence of sepsis (16.2% vs. 4.1%, P = .005) and death from sepsis (10.8% vs. 0%, P less than .001). Additional intrapartum conditions that might further predispose the low-birth-weight group to an increased risk of sepsis were not evident. Evaluation of the amniotic fluid did not demonstrate any increase in prevalence of group B streptococci, Escherichia coli, or enterococci in the low-birth-weight group. The presence of gram-negative anaerobes was significantly increased, however, in low-birth-weight pregnancies with IAI (59.5% vs. 31.6%, P = .001).

Amniotic Fluid↗

The role of the newer antimicrobial agents in obstetrics and gynecology.

The new antibiotics include interesting compounds--extended-spectrum cephalosporins and penicillins, combinations of older antibiotics plus beta-lactamase inhibitors, and new classes such as the monobactams and fluoroquinolones. In addition to extended spectrums, some of these compounds offer more favorable kinetics, less toxicity, or decreased cost. Several general conclusions might help place this array of new antibiotics in a useful clinical perspective. The newer antibiotics discussed here are no more effective than what is currently used. However, several have very good in-vitro activity against pelvic pathogens and are reasonable single-agent therapy in mild to moderate postpartum and postoperative infections. These antibiotics include cefoxitin, cefotetan, and piperacillin. Although moxalactam has good activity, its use is limited by concerns regarding bleeding disorders. Cefotaxime and cefoperazone have somewhat less favorable spectra, especially against anaerobes, yet in limited clinical trials are as effective as those cited above. Penicillin/beta-lactamase inhibitor combinations are currently being evaluated and appear to be reasonable choices. Although imipenem has an excellent in-vitro spectrum, it should probably be reserved for resistant cases. Aztreonam offers an alternative to gentamicin. However, in view of its greater cost, its use should be limited to patients in whom renal toxicity is a concern. For serious infections, combination therapy with clindamycin and gentamicin is our preference. For pelvic inflammatory disease, none of the agents is recommended as sole therapy due to the lack of coverage for chlamydia and frequent suboptimal coverage for anaerobes. Many of these agents have been effective for prophylaxis, but none has been shown to be superior to the older, less expensive agents such as cefazolin. Although many are effective in single doses, it is also likely that cefazolin is equally effective as a single dose. In addition, while most of the newer antibiotics are resistant to beta-lactamases themselves, they may induce their formation. This may ultimately result in limitations to the use of the relatively inexpensive prophylactic antibiotics.

Anti-Infective Agents↗

A randomized trial of intrapartum versus immediate postpartum treatment of women with intra-amniotic infection.

A randomized trial of intrapartum versus postpartum antibiotic treatment of women with intra-amniotic infection was conducted. Intra-amniotic infection was treated with ampicillin and gentamicin during labor (at the time of diagnosis) in 26 women and immediately after umbilical cord clamping in 19 women. Intrapartum treatment led to a lower incidence of neonatal sepsis (0 versus 21%; P = .03) and a shorter neonatal hospital stay (3.8 versus 5.7 days; P = .02) when compared with postpartum treatment. There were no significant differences in the microbiologic results, the gestational age, or the birth weight between the groups. Intrapartum-treated mothers had a shorter mean postpartum stay, a lower mean number of febrile days, and a lower mean peak postpartum temperature than did postpartum-treated mothers; these differences were all statistically significant (P = .05). The treatment of clinical intra-amniotic infection during labor results in improved outcome.

Adult↗

Prospective cost analysis of moxalactam versus clindamycin plus gentamicin for endomyometritis after cesarean section.

The direct and indirect costs associated with either moxalactam or clindamycin plus gentamicin as treatment for endomyometritis after emergent cesarean section were compared in an open, randomized prospective trial of 114 patients. A total of 58 patients were assigned to receive moxalactam, 2 g intravenously (i.v.) every 8 h for 5 doses, followed by 2 g every 12 h and prophylactic vitamin K (10 mg) intramuscularly, and 56 patients were assigned to receive clindamycin (600 mg) i.v. every 6 h plus gentamicin (1.5 mg/kg) i.v. every 8 h. Prothrombin times were measured in moxalactam-treated patients, and patients treated with clindamycin plus gentamicin had urinalyses and blood urea nitrogen and serum creatinine determinations performed before and after treatment. Also, gentamicin levels in serum were determined as clinically indicated. A satisfactory treatment response was defined as the resolution of signs and symptoms of endomyometritis within 3 days of the start of antibiotic therapy. Satisfactory responses were demonstrated in 78% of the moxalactam-treated patients and 84% of patients treated with clindamycin plus gentamicin. Mean hospital costs for laboratory tests ($30.30 versus $4.53) and mean patient charges for laboratory tests ($76.39 versus $27.81) and medications ($539.45 versus $421.82) were significantly higher in patients treated with clindamycin plus gentamicin (P less than 0.05), while mean medication costs to the hospital were greater in the moxalactam group ($255.47 versus $195.68; P less than 0.05). However, total patient charges and total hospital drug-associated costs were not significantly different for the two group. In this tudy, moxalactam was similar in efficacy and, despite its higher acquistion cost, was comparable in total hospital costs and patient charges to clindamycin plus gentacmicin in treating endomyometritis.

Cesarean Section↗