A quantitative analysis of the maturation of steroid negative feedbacks controlling gonadotropin release in the female rat: the infantile-juvenile periods, transition from an androgenic to a predominantly estrogenic control.

To determine what ovarian or adrenal steroid(s) are involved in restraining gonadotropin secretion in infantile female rats, several experiments were performed. Adrenalectomy of 10-day-old rats markedly decreased serum progesterone (P) and, to a lesser extent, serum estradiol (E2) levels. Androgen (A) levels were only transiently reduced, and serum dihydrotestosterone was not affected. Serum LH and FSH, on the other hand, increased only transiently after adrenalectomy. Ovariectomy (OVX) failed to decrease serum P and partially depressed serum E2, but resulted in a marked fall of both testosterone (T) and dihydrotestosterone. Serum LH and FSH were increased in these animals. Replacement of pre-OVX serum T levels via Silastic capsules prevented the postcastration rise in both LH and FSH, suggesting that the increase in gonadotropins that follows OVX of 10-day-old rats is, to a large extent, a consequence of the loss of ovarian T. OVX of juvenile (27 days old) rats increased serum FSH and LH 48 h later and reduced both serum T and E2 levels, with no significant change in serum P. Replacement of pre-OVX serum T levels depressed post-OVX serum FSH and LH titers only partially. In contrast, replacement of pre-OVX serum E2 levels, effectively suppressed the postcastration rise in serum gonadotropins. The results suggest that 1) during the infantile period, gonadotropin release is predominantly under ovarian androgenic inhibitory control, but this mechanism is not very effective, because basal serum gonadotropin levels, particularly FSH, are elevated; 2) the effectiveness of the A negative feedback on FSH remains unchanged during prepubertal development; and 3) the previously reported increase in E2 negative feedback effectiveness that occurs after day 15 results in an E2 inhibitory signal that surpasses that of As, so that during juvenile days, most of the ovarian steroidal inhibitory control on gonadotropin release is mediated by E2.

The maturation of estradiol-negative feedback in female rats: evidence that the resetting of the hypothalamic "gonadostat" does not precede the first preovulatory surge of gonadotropins.

Several experiments were performed to study the changes in the negative feedback of estradiol on gonadotropin secretion around the time of puberty in the female rat. Ovariectomy of juvenile, first diestrus, or adult animals elevated FSH and LH levels 2 and/or 4 days later. Estradiol administered via Silastic capsules, at several dose levels, was much more effective in preventing the postcastration rise of gonadotropins in juvenile than in the older animals. A dose of estradiol that inhibited gonadotropin levels in juvenile rats, but not in adult animals, maintained preovariectomy serum estradiol levels more efficiently in the adult rats. Therefore, a more rapid removal of estradiol from the blood stream cannot explain its lower effectiveness in suppressing gonadotropin release in adult rats. Estradiol-negative feedback effectiveness remained maximal until the day of first proestrus and decreased markedly on the next day (first estrus), remaining low thereafter. "Resetting" of the gonadostat to estradiol negative feedback was advanced by inducing precocious puberty by means of hyperprolactinemia, but not by mimicking the periovulatory changes in serum estradiol and progesterone in the absence of an LH surge. Serum progesterone levels were much higher in postpubertal rats than in juvenile animals. Ovariectomy of juvenile rats slightly decreased the already low levels of serum progesterone, but it produced a striking progesterone decrease in postpubertal animals. Quantitative replacement of preovariectomy serum progesterone levels in adult rats, treated with an ineffective dose of estradiol, almost completely restored the prepubertal effectiveness of estradiol in inhibiting LH release and, to a lesser extent, release of FSH...

Development of estradiol-positive feedback on luteinizing hormone release in the female rat: a quantitative study.

Experiments were conducted to study, in a quantitative manner, the development of estradiol (E2)-positive feedback on LH release in the female rat. A Silastic capsule (20 mm in length/100 g BW) containing E2 dissolved in corn oil (400 micrograms/ml) reproduced first proestrous levels of serum E2 when implanted sc in juvenile rats of different ages (days 20-32). When similar capsules were implanted in infantile rats (days 10-18), serum E2, measured 2 days later, was found to be extremely elevated in 12- and 14-day-old rats (4-6 times higher than first proestrous levels), declining thereafter so that in 16- to 20-day-old rats the levels were only 2-fold greater than proestrous values. Serum levels of alpha-fetoprotein decreased markedly between days 12-28, and both normal and implant-produced serum E2 levels paralleled the decline in the protein titers. However, calculation of the total E2 binding capacity of alpha-fetoprotein indicated that in addition to binding to this protein, there are additional factors responsible for the persistence of E2 in the serum of infantile rats. A LH surge could not be induced in 12- or 14-day-old rats by a 48-h E2 pulse, despite the presence of substantial amounts of free E2, which exerted profound negative feedback effects. Between days 16-20, only E2 levels that were at least 2-fold higher than first proestrous values were effective in inducing a LH surge. Between days 22-34, a LH surge was elicited by serum E2 levels very similar to those seen during the first proestrus. By days 26-28, the profile of the LH surge was indistinguishable from that of the first preovulatory surge. Starting on day 26, and in addition to the LH surge elicited by the 48-h E2 pulse, an earlier surge occurred on the next day after E2 implantation. By day 30, the early LH surge became firmly established, and the late surge was no longer apparent. It is suggested that in the female rat, the development of E2-positive feedback comprises four phases: phase I, before day 16, in which the surge mechanism of the LH-releasing system is not developed; phase II, between days 16-20, in which E2 levels twice as high as those of first proestrus are necessary to activate the LH surge mechanism; phase III, which is initiated at the beginning of the juvenile period (approximately days 20-22) and in which the LH surge mechanism responds to E2 levels of preovulatory magnitude; and mechanism responds to E2 levels of preovulatory magnitude; and phase IV, which begins around days 26-28 and in which a 24-h exposure to E2 levels of preovulatory magnitude is sufficient to elicit a LH surge.

Expression and purification of the HIV type 1 Rev protein produced in Escherichia coli and its use in the generation of monoclonal antibodies.

We have developed a simple and rapid procedure for the purification of large amounts of Rev protein overexpressed in E. coli. The purification method, which does not require denaturation of the protein, takes advantage of the positively charged nature of Rev and the ability of Rev to interact with nucleic acids. The purified protein was used to develop three novel murine monoclonal antibodies against Rev. Using fusion proteins between glutathione S-transferase (GST) and various fragments of the Rev protein, we mapped the specificity of these antibodies to different regions of the Rev protein. One antibody, 3H6, is directed against the nucleolar localization/RRE-binding domain of Rev between amino acids 38 and 44. Another antibody, 3G4, recognizes an epitope between amino acids 90 and 116 of Rev. A third antibody, 2G2, does not recognize any of the fusion proteins, and may be directed against a conformational epitope. All three antibodies are able to detect Rev on Western blots and to immunoprecipitate Rev under native conditions. However, only 3H6 and 3G4 immunoprecipitate Rev under denaturing conditions and are able to detect Rev expressed in transfected cells by indirect immunofluorescence. These antibodies should prove useful in further studies of Rev function.

Attenuation of monochromatic X-rays by normal and abnormal breast tissues.

RATIONALE AND OBJECTIVES: A prior study indicated that differences in the x-ray linear attenuation coefficients of cancerous and normal breast tissues tend to increase as the energy of the incident beam decreases. The authors investigated x-ray energies down to 20 keV. In the current study, the linear attenuation coefficients for normal and selected cancerous breast tissues within the energy range of 14 to 18 keV were determined. METHODS: Fifty breast biopsy specimens consisting of a mixture of breast malignancies, normal tissues, fat specimens, and tumors grown in rats were used. X-ray linear attenuation coefficients were measured for each sample within the energy range of 14.15 to 18 keV, using monoenergetic x-rays from beamline X-19A at the National Synchrotron Light Source at Brookhaven National Laboratory. Each sample was measured at 130 different energies starting at 14.15 keV with step sizes of 0.030 keV. Correlation of the measured attenuation coefficients for cellular makeup was performed. RESULTS: The mean of linear attenuation coefficients for samples classified as "cancers" was 10.9% higher than the mean of samples classified as "normal" breast tissues and was 66.5% higher than the mean of samples classified as normal breast fat. CONCLUSIONS: Differences in the linear attenuation coefficients of monochromatic x-rays between 14.15 and 18 keV do exist between normal and cancerous tissues, but there is some degree of overlap.

Amnioinfusion survey: prevalence, protocols, and complications.

OBJECTIVE: To determine whether amnioinfusion is associated with labor and delivery complications, and whether complication type and reported incidence are related to infusion method. METHODS: Questionnaires regarding amnioinfusion experience were sent to every academic obstetrics and gynecology department in the United States (78 maternal-fetal medicine fellowship directors or, if the department did not have a fellowship, 206 residency directors). A literature review on amnioinfusion was also performed. RESULTS: Seventy-six percent of fellowship directors and 62% of residency directors responded to our survey, representing 644,910 deliveries per year and at least 22,833 amnionfusions per year. A wide variety of infusion protocols were reported. Forty-nine centers reported at least one associated complication; none was significantly associated with any of the various aspects of the many protocols (P > .05). The mean number (+/- standard error of the mean) of amnioinfusions performed annually was similar between centers that did (261 +/- 48) and did not (154 +/- 29) report complications (P = .06). The literature review suggested that amnioinfusion is efficacious and relatively safe. CONCLUSION: Amnioinfusion is performed nationwide according to widely varying protocols with few associated complications. Neither the method employed nor the number of infusions performed appears to significantly increase the risk of having a complication.

Screening and treatment of asymptomatic bacteriuria of pregnancy to prevent pyelonephritis: a cost-effectiveness and cost-benefit analysis.

OBJECTIVE: To compare the effectiveness, benefits, and costs of two asymptomatic bacteriuria screening and treatment strategies to prevent pyelonephritis in pregnancy. METHODS: A decision analytic model was created to compare strategies based on either 1) a leukocyte esterase-nitrite dipstick, or 2) on urine culture, with a policy of no screening or treatment. A literature search was conducted to generate probability estimates. Cost estimates were based on a local pharmacy and laboratory survey and supplemented by recent literature estimates. Sensitivity analyses were performed over wide ranges of probability and cost estimates. RESULTS: Under baseline assumptions, no screening resulted in 23.2 cases of pyelonephritis per 1000 pregnancies, versus 16.2 cases with the dipstick strategy and 11.2 with the culture strategy. The cost of screening and treatment of asymptomatic bacteriuria per 1000 pregnancies was $1968 with dipstick and $19,264 with culture. The cost of treating pyelonephritis with no screening was $57,562, versus $40,257 with dipstick and $27,832 with culture. Therefore, both the dipstick strategy and the culture strategy were cost-beneficial (based on a pyelonephritis cost of $2485) when compared with no screening. However, because it cost $3492 to prevent each additional case of pyelonephritis with culture that was not prevented by dipstick, the culture strategy was not cost-beneficial compared with the dipstick strategy. These results were sensitive to varying estimates for the prevalence of asymptomatic bacteriuria, the rate of progression of asymptomatic bacteriuria to pyelonephritis, the sensitivity of the dipstick, culture costs, and the cost of a case of pyelonephritis. CONCLUSION: When compared with a policy of no screening, screening for and treatment of asymptomatic bacteriuria to prevent pyelonephritis in pregnancy is cost-beneficial whether based on the leukocyte esterase-nitrite dipstick or on urine culture. However, the culture strategy is not cost-beneficial when compared with the dipstick strategy.

Vaginal fetal fibronectin levels and spontaneous preterm birth in symptomatic women.

OBJECTIVE: To relate vaginal fetal fibronectin levels in women with symptoms of preterm labor to subsequent spontaneous preterm birth. METHODS: Quantitative fetal fibronectin values were calculated from women who participated in two prospective multicenter trials relating fetal fibronectin to subsequent spontaneous preterm birth. The study populations consisted of women who presented with symptoms of preterm labor between 24(0)/(7) and 34(6)/(7) weeks, a singleton pregnancy, intact membranes, no prior tocolysis, and cervical dilation less than 3 cm. RESULTS: The characteristics of the two study populations were similar. In both populations, the rates of delivery within 7, 14, and 21 days after sampling were clustered into three distinct fetal fibronectin groups (less than 40, 40-100, and 100 ng/mL or more). As fetal fibronectin values increased, the risk of subsequent spontaneous preterm birth also increased. Delivery within 7 days of sampling was 0.4%, 3.3%, and 18.2% (trial A) and 1.4%, 8.0%, 30.0% (trial B) as the fetal fibronectin levels increased from less than 40 ng/mL, to 40-100 ng/mL, and to at least 100 ng/mL, respectively. CONCLUSION: In women with symptoms of preterm labor, an increase in fetal fibronectin from under 40 ng/mL, to 40-100 ng/mL, to at least 100 ng/mL was associated with a progressive increase in the risk of subsequent spontaneous preterm birth. The use of a single fetal fibronectin cutoff of 50 ng/mL for defining a positive test in women with symptoms of preterm labor should be reevaluated.

Detection of genitourinary tract Chlamydia trachomatis infection in pregnant women by ligase chain reaction assay.

OBJECTIVE: To compare the sensitivity and specificity of a ligase chain reaction assay of cervical swabs and voided urine with those of cervical swab tissue culture for the detection of genitourinary tract infection with Chlamydia trachomatis in pregnant women. METHODS: Infection with C trachomatis was assessed in cervical swabs by culture and in both cervical swabs and voided urine specimens by a ligase chain reaction assay specific for C trachomatis plasmid DNA. The matched cervical swab and voided urine specimens were collected from 462 women during routine visits to prenatal clinics. Standard criteria that defined infection included: 1) a positive cervical culture result or 2) a negative culture but a positive ligase chain reaction result in either the urine or cervical specimen that was confirmed by supplementary testing. Test performance was assessed by determination of sensitivity and specificity, and differences in paired results were determined using McNemar analysis. RESULTS: The prevalence of genitourinary C trachomatis infection was 6.1% (n = 28) by cervical culture (sensitivity 30.1%; specificity 100%), 18.2% (n = 84) by ligase chain reaction of cervical swabs (sensitivity 90.3%; specificity 100%), and 16.9% (n = 78) by ligase chain reaction of urine (sensitivity 83.9%; specificity 99.5%). Relative to the number of women with a positive culture or a confirmed ligase chain reaction-positive cervical swab, the sensitivity and specificity were 82.8% and 97.9%, respectively, for ligase chain reaction of urine and 96.6% and 100%, respectively, for ligase chain reaction of cervical swabs. Ligase chain reaction of cervical swabs and urine detected 89.3% and 82.1%, respectively, of women with a positive cervical culture. CONCLUSIONS: Ligase chain reaction assay of cervical or urine specimens detected considerably more pregnant women with C trachomatis infection of the genitourinary tract than did cervical culture. Ligase chain reaction testing of urine is a simple and effective means of screening pregnant women for genitourinary tract infection with C trachomatis.

Necrotizing fasciitis after cesarean delivery.

OBJECTIVE: To review our experience with the diagnosis and management of necrotizing fasciitis after cesarean delivery. METHODS: We reviewed medical records of women with serious post-cesarean wound infections at the University of Alabama at Birmingham between 1987 and 1994 to identify women with necrotizing fasciitis. The diagnosis of necrotizing fasciitis required intraoperative identification of necrotic fascia in febrile women undergoing post-cesarean wound debridement. RESULTS: During the study period, 5048 women had cesarean deliveries, nine of which were complicated by necrotizing fasciitis. The mean (+/-standard deviation) maternal age was 27 +/- 6 years, and the mean maternal weight was 199 +/- 64 lb. None of the patients had insulin-dependent diabetes mellitus, and none had known peripheral vascular disease. There were no intraoperative complications at cesarean delivery. The mean time from cesarean delivery to the diagnosis of necrotizing fasciitis and reoperation was 10 +/- 4 days (range 5-17). All patients had surgical debridement upon consideration of the diagnosis, and all received broad-spectrum antimicrobial therapy. Results of wound cultures were available in seven of the women, and all seven were found to have polymicrobial infections. There were two mortalities, one as a result of metastatic breast cancer and another with complications of sepsis. CONCLUSION: Necrotizing fasciitis is infrequent (1.8 per 1000 women) after cesarean delivery at our institution, but it does result in appreciable morbidity and mortality.

Genital herpes during pregnancy: inability to distinguish primary and recurrent infections clinically.

OBJECTIVE: To determine if the signs and symptoms of genital herpes in pregnancy accurately identify primary genital herpes infections using serologic testing for final classification. METHODS: Twenty-three women with clinical signs and symptoms suggestive of primary genital herpes infections in the second and third trimesters of pregnancy were subsequently cultured and tested serologically (for herpes simplex virus type 1 and herpes simplex virus type 2 antibodies) and classified as having true primary (no herpes simplex virus type 1 or type 2 antibodies), nonprimary (heterologous herpes simplex virus antibodies present), or recurrent (homologous antibodies present) infections. RESULTS: Only one of 23 women with clinical illnesses consistent with primary genital herpes virus simplex infections had serologically-verified primary infection. This primary infection was caused by herpes simplex virus type 1. Three women had nonprimary type 2 infections, and 19 women had recurrent infections. Among culture-proven recurrent infections, 12 were caused by herpes simplex virus type 2 and three by herpes simplex virus type 1. Only one infant was born preterm, and no clinically significant perinatal morbidity was observed. CONCLUSION: Correct classification of gestational genital herpes infections can be accomplished only when clinical evaluation is correlated with viral isolation and serologic testing using a type-specific assay. Severe first episodes of genital herpes infections among women in the second and third trimesters of pregnancy are not usually primary infections and are not commonly associated with perinatal morbidity.

Second-trimester cervical ultrasound: associations with increased risk for recurrent early spontaneous delivery.

OBJECTIVE: To determine whether short cervical length or internal os funneling before 20 weeks' gestation predicts early preterm birth or pregnancy loss in women with at least one prior spontaneous early preterm birth. METHODS: Transvaginal cervical ultrasound examinations were done every 2 weeks on 69 women with singleton gestations and histories of at least one prior spontaneous birth between 16 and 30 weeks' gestation. The results of those examinations were correlated with gestational age at delivery. RESULTS: Among 53 women who had ultrasound examinations before 20 weeks' gestation, those with cervical lengths at or below the tenth percentile for the study population (22 mm, n = 4) or funneling of the internal os (n = 5) were more likely than women without those factors to have spontaneous preterm births within 2 weeks (33% versus 0%, P = .01) or 4 weeks from the ultrasound examination (67% versus 0%, P < .001) or before 35 weeks' gestation (100% versus 19%, P < .001). Short cervical length or funneling between 20-24 and 25-29 weeks was also associated with increased risk of spontaneous preterm birth before 35 weeks' gestation (P < or = .05 and P = .002, respectively) but not with increased risk of spontaneous preterm birth within 2 or 4 weeks of ultrasound examination. CONCLUSION: Women with prior early spontaneous preterm births who have short cervical lengths or funneling of the internal cervical os before 20 weeks' gestation are at increased risk of subsequent spontaneous preterm birth.

Bed rest in pregnancy.

OBJECTIVE: To summarize existing data about the effectiveness of bed rest when used to improve various pregnancy outcomes and to determine how often bed rest is used and the cost associated with its use. DATA SOURCES: We used the MEDLINE data base to search for all English language papers evaluating the effectiveness of bed rest in pregnancy. We also reviewed a number of textbooks and the 1988 National Infant Mortality Survey. METHODS OF STUDY SELECTION: We reviewed these sources for recommendations about using bed rest in various obstetric conditions. We used the 1988 National Infant Mortality Survey to determine how often bed rest was used either to prevent or to treat various obstetric conditions and estimated the costs associated with its use. DATA EXTRACTION AND SYNTHESIS: Bed rest is used in nearly 20% of all pregnancies to prevent or treat a wide variety of conditions, including spontaneous abortion, preterm labor, fetal growth retardation, edema, chronic hypertension, and preeclampsia. There is little evidence of effectiveness. The estimated costs associated with bed rest, including hospitalization, lost wages, and lost domestic productivity, range from more than $250 million to billions of dollars per year. CONCLUSIONS: Bed rest is used extensively to treat a wide variety of pregnancy conditions, at substantial cost but with little proof of effectiveness. We recommend that because this intervention has failed the test of effectiveness, its use during pregnancy should be curtailed unless randomized trials demonstrate improvement in a specific outcome.

Elective hospitalization in the management of twin pregnancies.

We sought to evaluate the effectiveness of a policy of early elective hospitalization on the outcomes of 522 consecutive twin gestations delivered at our institution between 1983-1987. During the first 2 years (1983-1985), 237 twin pregnancies were delivered with a policy of elective hospitalization when twin pregnancy was diagnosed between 24-32 weeks' gestation. When possible, elective hospitalization started at 24 weeks' gestation. Electively admitted women remained hospitalized until 34 weeks' gestation, at which time they were discharged unless complications developed requiring continued hospitalization. During 1985-1987, 285 women with twin gestations were intentionally managed as outpatients unless intercurrent complications required hospitalization. A total of 211 twin pregnancies was excluded from analysis because the women did not present for prenatal care (19%) or were undiagnosed until delivery (22%). Of the remaining 311 pregnancies available for study, 134 were managed when the elective admission policy prevailed and 177 when this policy was not in effect. Although the elective admission policy did result in a small reduction in the incidence of low birth weight among the 58 pregnancies hospitalized electively (mean [+/- SEM] gestational age at elective hospitalization 27.7 +/- 0.3 weeks) compared with outpatient management, this policy did not result in an improvement in prematurity (32 versus 36%; P greater than .05) or perinatal morbidity as reflected by requirement for neonatal intensive care (12 versus 11%; P greater than .05) and mechanical ventilation (8 versus 9%; P greater than .05). Moreover, perinatal mortality was actually higher in the electively hospitalized pregnancies (8 versus 2%; P = .01).(ABSTRACT TRUNCATED AT 250 WORDS)

Association of post-cesarean delivery endometritis with colonization of the chorioamnion by Ureaplasma urealyticum.

OBJECTIVE: To determine if asymptomatic antenatal colonization of the chorioamnion with Ureaplasma urealyticum is a risk factor for the development of post-cesarean delivery endometritis. METHODS: The chorioamnion was cultured at cesarean delivery for aerobic and anaerobic bacteria, mycoplasmas, Chlamydia trachomatis, and Trichomonas vaginalis in 575 singleton gestations with intact membranes. Culture results were compared with the clinical outcome. Postoperative endometritis was defined as a temperature of 38C with uterine tenderness and without other nonpelvic sources of fever. RESULTS: Fifty-eight (10%) of the 575 women developed endometritis. Women with spontaneous labor developed endometritis twice as often as those delivered for medical or obstetric indications (17 versus 8%, P = .002). Endometritis occurred in 28% of women with U urealyticum present in the chorioamnion at cesarean delivery, compared with only 8.4% if the culture was negative and 8.8% if only bacteria other than U urealyticum were isolated (P < .001). Gestational age less than 34 weeks, spontaneous labor, and a vertical uterine incision were all associated with endometritis (P < or = .002). Regression analysis controlling for gestational age and incision type revealed a threefold increased risk of endometritis if the chorioamnion was colonized with U urealyticum at cesarean (odds ratio [OR] 3.0, 95% confidence interval [CI] 1.1-8.3) and an eightfold risk (OR 7.7, 95% CI 1.9-31.5) in women in whom the onset of labor was spontaneous. CONCLUSION: Colonization of the chorioamnion with U urealyticum in women with intact membranes being delivered by cesarean is a significant, independent predictor of subsequent endometritis.

Intrauterine viral infection at the time of second trimester genetic amniocentesis.

OBJECTIVE: To determine whether preexisting intrauterine viral infection is associated with postamniocentesis pregnancy loss. METHODS: We accessed our bank of second-trimester amniotic fluid (AF) samples obtained aseptically and stored at -20C from all 11,971 women who underwent genetic amniocentesis between 1988 and 1995. Samples were retrieved from every case of spontaneous pregnancy loss within 30 days of the amniocentesis (excluding aneuploidy and anomalies, n = 66). Sixty-six control samples were randomly chosen from subjects who delivered at term and were matched for year of test, gestational age, maternal age, and indication for amniocentesis. Investigators were blinded to the status of the samples, which were studied by polymerase chain reaction (PCR) for the presence of adenovirus, parvovirus, cytomegalovirus, Epstein-Barr virus, herpes simplex virus, enterovirus, influenza A virus, and beta-actin DNA. Results were compared with interleukin-6 (IL-6) levels previously measured by enzyme-linked immunosorbent assay in the same samples. RESULTS: Sixty-two study cases and 60 controls were sufficient for all PCR studies. Fourteen AF samples contained a single virus: five (8%) of 62 study cases and nine (15%) of 60 controls (P = .27). Adenovirus accounted for nine (64%) of 14 viruses identified: four of 62 cases and five of 60 controls (P = .74). Cytomegalovirus was not identified in any study cases but was found in three controls. The mean IL-6 levels in samples with and without virus were not significantly different (4.8+/-15.9 ng/mL with virus compared with 2.0+/-8.8 ng/mL without virus; P = .53). CONCLUSION: Presence of virus in second-trimester AF is not significantly associated with elevated IL-6 levels or with early postamniocentesis pregnancy loss.

Antibiotic susceptibility profile of group B streptococcus acquired vertically.

OBJECTIVE: To determine the contemporary antibiotic susceptibility profile of vertically acquired group B streptococcal isolates. METHODS: Susceptibility to ampicillin, penicillin G, erythromycin, clindamycin, cefazolin, and gentamicin was assessed by two methods, minimal inhibitory concentration and disc diffusion. RESULTS: The susceptibility profiles of 119 colonizing and eight invasive strains of group B streptococcus isolated from January 1996 to September 1997 at two hospitals in Birmingham, Alabama-University of Alabama at Birmingham and Cooper Green-were studied. Minimal inhibitory concentration determinations indicated that all colonizing strains were susceptible or moderately susceptible to ampicillin and penicillin G. Resistance was noted by at least one strain to each of the other antibiotics; all were resistant to gentamicin, whereas 27 (21%) were resistant to erythromycin, five (4%) to clindamycin, and one (1%) to cefazolin. All of the eight invasive strains were susceptible or moderately susceptible to ampicillin, penicillin G, clindamycin, and cefazolin; one (13%) was resistant to erythromycin, and all were resistant to gentamicin. Disc diffusion results generally were concordant with minimal inhibitory concentration results, although by disc diffusion fewer isolates were classified as susceptible, and more as moderately susceptible, to ampicillin and penicillin G than by minimal inhibitory concentration. CONCLUSION: Universal susceptibility of group B streptococcus to members of the penicillin family supports the continued use of penicillin G or ampicillin for early onset neonatal group B streptococcal disease prevention. For patients allergic to beta-lactam agents, clindamycin (4% resistance) may be a better alternative than erythromycin (21% resistance).

Studies on the central effect of prolactin in inducing precocious puberty in the female rat.

Implantation of prolactin (PRL) into the median eminence (PRL-ME implants) of 23 day old female rats markedly advanced the onset of puberty, as measured by the age at vaginal opening and at first ovulation. Precocious puberty was preceded by steroidogenic activation of the ovary, as reflected by increases in uterine weight and an enhanced in vitro steroidal responsiveness of the ovary to hCG. The stimulatory effect of PRL-ME implants could not be attributed to alterations in the release of LH, FSH, GH or TSH from the anterior pituitary. Likewise, the PRL effect was neither exerted through the adrenal gland nor involved activation of a direct neural, vagal-mediated influence on the ovary. Furthermore, the effect of PRL-ME implants was not due to a decrease in pituitary secretion of opioid substances, which appear to restrain chronically gonadotropin release during female prepubertal development. These latter experiments also showed that administration of the opioid agonist, morphine, can delay the onset of puberty in the female rat. Although local exposure of the medial basal hypothalamus to high PRL levels is extremely effective in accelerating puberty, the mechanisms by which this effect is exerted remains to be elucidated.

Bacterial vaginosis: association with adverse pregnancy outcome.

Bacterial vaginosis is the most common lower genital tract infection encountered among women of reproductive age. This condition can best be considered as a vaginal syndrome associated with an alteration of the normal vaginal flora rather than an infection specific to any one microorganism. Bacterial vaginosis is a clinical condition with a complex microbiology that is characterized by a reduced concentration of a normally abundant Lactobacillus species along with high concentrations of gram-negative and anaerobic bacteria, particularly, Gardnerella vaginalis and Mobiluncus, Bacteroides, Prevotella, and Mycoplasma species. The exact make up of the microorganisms and their relative concentration vary among women who have this condition. Although it was previously regarded as a harmless condition, recent work has linked bacterial vaginosis to numerous upper genital tract complications such as preterm labor and preterm delivery, preterm premature rupture of the membranes, chorioamnionitis, and postpartum endometritis. The findings from recent prospective randomized trials suggest that treatment of bacterial vaginosis in certain women who are at high risk for preterm delivery decreases the rate of preterm birth.

Sexually transmitted diseases and adverse outcomes of pregnancy.

We emphasize again that the prevalence of maternal infections may vary in different populations, and others might arrive at different estimates about the percentage of infants colonized and, concerning those infants colonized, about the percentage with adverse outcomes. Additionally, many women are colonized or infected simultaneously with several of the organisms discussed in this review, and this may result in different projections of morbidity and mortality rates than those presented here. We realize also that new information is generated continually describing the relationship between various maternal colonizations and preterm birth, and that screening and treatment protocols for several diseases may reduce the prevalence of adverse outcomes reported here. Therefore, we emphasize that the prevalences of various adverse pregnancy outcomes, as presented in this article, are only approximations and may change as new information becomes available. Nevertheless, we believe it is reasonable to estimate the relative effect of various maternal sexually transmitted diseases on adverse pregnancy outcome as we have done in this article. By comparing the effect of direct transmission of sexually transmitted organisms on adverse outcomes with the effect on overall outcome through an increase in the rate of preterm births, we should be able to use this type of analysis to establish some basis for allocation of resources to future research as well as intervention programs aimed at reducing sexually transmitted disease-related adverse outcomes of pregnancy. Finally, the appreciation of the effect of bacterial vaginosis on outcomes of pregnancy associated with preterm birth gives bacterial vaginosis a greater public health importance than has been attributed to it in the past as the subject of sexually transmitted disease research and prevention.