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Biomedical subjects

B S Block

Publications and source records attributed to B S Block.

At least 19 recordsLinked to original sources
PubMed1994

CA-125 in peritoneal fluid from patients with nonmalignant gynecologic disorders.

To assess the diagnostic value of measuring CA-125 levels in peritoneal fluid from women with nonmalignant gynecologic disorders, we determined CA-125 levels in peritoneal fluid and in serum collected simultaneously from 46 women undergoing gynecologic surgery. Patients with benign ovarian disease, non-ovarian gynecologic pathology and severe endometriosis had, on average, higher CA-125 levels in peritoneal fluid than did patients with a normal pelvis and those with mild endometriosis. There was no obvious correlation between peritoneal fluid and serum levels of CA-125. Our data show that (1) measurement of serum CA-125 levels is not useful for distinguishing between different benign gynecologic disorders, and (2) levels of CA-125 in peritoneal fluid in benign gynecologic disorders are comparable to the reported lower range of levels observed in women with intraperitoneal malignancies.

Aftercare↗
PubMed1991

The effect of filtration of amniotic fluid on the growth of Chlamydia trachomatis and Escherichia coli.

There is increasing concern about Chlamydia trachomatis infection during pregnancy, because of reports of increased maternal, fetal, and neonatal risks. Amniotic fluid is known to possess antibacterial activity and has recently been shown to inhibit formation of chlamydial inclusions in McCoy cell culture. To further characterize the anti-chlamydial factor, we investigated the effect of filtering the fluid (0.45 microns pores) prior to incubation. Amniotic fluid was obtained from 12 women at term gestation, either by amniocentesis, or at cesarean section, Chlamydial inclusion formation was studied in McCoy cell cultures, and Escherichia coli growth was studied by a plate-count method. Filtered amniotic fluid had significantly less inhibitory activity against chlamydial inclusion formation than nonfiltered fluid did. Both filtered and nonfiltered amniotic fluid were equally effective in inhibiting E. coli colony growth. These data suggest that the chlamydial inhibitor in amniotic fluid does not pass through 0.45 microns pores and is larger than the bacterial inhibitor that was reported to be a peptide of low molecular weight.

Amniotic Fluid↗
PubMed1990

Intrauterine asphyxia and the breakdown of physiologic circulatory compensation in fetal sheep.

In response to acute hypoxemia, the fetus invokes physiologic compensatory mechanisms that cause a preferential redistribution of the circulation to sustain the brain, heart, and adrenal gland and maintain blood flow to the placenta. These mechanisms are available for a limited time and eventually the fetus is no longer able to maintain preferential perfusion and decompensation occurs. To identify the relationship between hypoxemia with severe acidemia and the breakdown of circulatory compensation, we decreased uterine blood flow in 10 chronically instrumented pregnant sheep. We measured fetal blood gases and pH, arterial and central venous pressures, heart rate, combined ventricular output, and regional blood flow distribution during hypoxemia with severe acidemia and when a fixed-baseline sustained bradycardia (agonal) heart rate pattern developed. Hypoxemia with severe acidemia was characterized by markedly decreased blood flow to most organs; however, the preferential perfusion of the brain, heart, adrenal gland, and placenta was still present. An agonal heart rate pattern was characterized by complete cardiovascular collapse. This study demonstrates that circulatory compensation is present in fetal sheep affected by deficiency of oxygen delivery despite hypoxemia with severe acidemia.

Adrenal Glands↗
PubMed1990

Evaluating the quality of perinatal health care.

1. The quality of perinatal health care is indirectly evaluated by determining the PNM rate. 2. The standardized PNM rate is a useful index to identify perinatal care facilities that need further review by perinatal mortality audit. 3. Long-term follow-up is needed to determine if decreasing mortality by obstetric interventions is accompanied by a beneficial effect on the surviving infants or by an increase in morbidity. 4. In the near future, mortality and severity of illness data will be required for hospital accreditation. 5. The present challenge is to contain costs without lowering the quality of care.

Female↗
PubMed1990

Regional blood flow distribution in fetal sheep with intrauterine growth retardation produced by decreased umbilical placental perfusion.

To determine the capacity of the fetus to adapt to chronic O2 deficiency produced by decreased placental perfusion in the early development of growth retardation, we embolized the umbilical placental vascular bed of fetal sheep for a period of 9 days. Fetal umbilical placental embolization decreased arterial O2 content by 39%, decreased total placental blood flow by 33%, and produced a 20% reduction in mean fetal body weight. Neither the combined ventricular output nor the regional blood flow distribution was significantly different between the 8 growth-retarded and 7 normally grown fetuses despite the 39% decrease in fetal arterial O2 content. Thus a 33% reduction in total placental blood flow restricts normal fetal growth, but does not exceed the placental circulatory reserve capacity necessary to maintain normal basal metabolic oxygenation. Because the proportion of combined ventricular output to the placenta at rest is decreased in late IUGR fetuses but not in early IUGR fetuses, despite chronic oxygen deficiency, we conclude that the growth retarded fetus maintains a normal regional blood flow distribution until the placental circulatory reserve capacity is depleted.

Animals↗
PubMed1989

Understanding and eliminating errors in perinatal research.

Research studies published in the scientific literature have had a rapid impact on medical practice, especially in clinical obstetrics. Recently, incentives to control medical costs without sacrificing the quality of care have placed increased importance on studies that truly demonstrate clinical effectiveness. In addition, there are ethical concerns that improperly designed or conducted studies adversely affect medical practice and place patients at unnecessary risk. This article summarizes potential sources of error and encourages the valid interpretation of the results and conclusions of experimental studies by making four suggestions: (1) the errors and limitations that may be present in the methodology should be described and explanations given how the errors might have affected the results and why the limitations are acceptable; (2) the methods selected should allow an answer to the question proposed; (3) the investigator should verify that the appropriate statistical test is used; and (4) when unexpected or hard to explain results are found, verification before publication should be undertaken.

Models, Theoretical↗
PubMed1989

Intrauterine growth retardation and the circulatory responses to acute hypoxemia in fetal sheep.

Intrauterine growth retardation has been produced experimentally by umbilical placental embolization for 9 days (early intrauterine growth retardation) in pregnant sheep. Fetuses with early intrauterine growth retardation had a 20% decrease in mean body weight and 33% decrease in placental blood flow. However, the regional blood flow distribution was not significantly different at rest between the embolized and normally grown fetuses despite the 39% decrease in fetal arterial oxygen content. The purpose of this study was to determine the circulatory responses to acute hypoxemic stress in the early development of intrauterine growth retardation. We found that the regional blood flow distribution was not significantly different during imposed acute hypoxemia between the seven fetuses with early intrauterine growth retardation and seven nonembolized normally grown fetuses. We conclude that growth-retarded fetuses are able to meet basal metabolic oxygen requirements and to respond normally to imposed acute hypoxemia until the placental circulatory reserve capacity is depleted.

Animals↗
PubMed1989

The effect of the alpha-emitting radionuclide lead-212 on human ovarian carcinoma: a potential new form of therapy.

To improve response and survival of patients with ovarian carcinoma noncross-resistant forms of therapy must be developed. alpha-emitting radionuclides may be therapeutically useful since they can directly ionize with energies of 5 to 9 MeV, penetrate only a few cell diameters, and transfer a high amount of energy. The purpose of this study was to determine the effect of the alpha-emitter, lead-212 (212Pb), complexed to sulfur in a nude athymic mouse model (NIH:OVCAR-3) containing human ascites and solid epithelial ovarian carcinoma. Thirty-six nude mice 28 to 32 days old were injected with 10(7) to 10(8) carcinoma cells from donor mice. After 4 weeks, six groups of six nu/nu athymic BALB-C mice were intraperitoneally injected with 70, 50, 20, 5 microCi of 212Pb sulfur colloid, sulfur colloid, or saline. Tumor necrosis with a decrease in ascites and a dose-related survival were noted with doses of 50, 20, and 5 microCi. With 70 microCi acute gastrointestinal toxicity developed. These experiments form the basis for further investigations and the development of alpha-emitting radiocolloids which may be of therapeutic efficacy in the treatment of intraperitoneal ovarian carcinoma.

Animals↗
PubMed1989

Effects of ritodrine and fetal oxygenation after in utero fetal surgery in sheep.

Surgical procedures which involve the pregnant uterus are associated with preterm labor contractions in the postoperative period. Because uterine contractions decrease fetal oxygen tension, we investigated the effect of maternal ritodrine infusion on fetal oxygen consumption in catheterized fetal sheep 5 h postoperatively. During ritodrine infusion, uterine activity promptly abated, but the oxygen tension in the umbilical vein and descending aorta decreased. The arterial-venous oxygen content difference, the umbilical blood flow, and consequently, fetal oxygen consumption did not change significantly. We conclude that fetal oxygenation is not improved by eliminating uterine activity with maternal ritodrine infusion in the postoperative period.

Animals↗
PubMed1988

Abortion hysterectomy for gynecologic pathology.

Abortion hysterectomy has been discredited as the method of performing simultaneous pregnancy termination and elective sterilization for women with undesired pregnancies who simultaneously wish to end their child-bearing potential. The procedure continues to be advocated, however, for cases in which there is an underlying gynecologic pathologic condition. The morbidity of this procedure has not been directly compared with that for indicated hysterectomy in nonpregnant women. Between January 1976 and January 1987, 50 patients underwent abortion hysterectomy at The University of Chicago. The morbidity and mortality rates of these patients were compared with those of 50 premenopausal nonpregnant women undergoing abdominal hysterectomy for gynecologic pathologic status. There was no statistically significant different between the groups in the duration of surgery, estimated blood loss, or infectious morbidity. No operative site infections or other adverse sequelae were noted at the time of final postoperative examination. These data support the relative safety of abdominal abortion hysterectomy for women with undesired pregnancy in whom hysterectomy is indicated for an underlying gynecologic pathologic condition.

Abortion, Therapeutic↗
PubMed1988

Comparison of human chorionic gonadotropin regression in molar pregnancies and post-molar nonmetastatic gestational trophoblastic neoplasia.

The rate of regression of the beta subunit of human chorionic gonadotropin in patients successfully treated by single-agent chemotherapy with methotrexate (MTX) for postmolar nonmetastatic gestational trophoblastic neoplasia (NMGTN) has not previously been described. In 21 patients with NMGTN treated with MTX, the rate of regression was determined. Nineteen patients had a log-exponential disappearance of serum beta-hCG titers within 100 days. There was a 50% probability of a negative titer at 50 days. Two patients had plateauing titers within 63 days after therapy. There was no difference in beta-hCG disappearance whether MTX with citrovorum factor or MTX alone was administered. Also, the regression rate of beta-hCG titer in the treated patients was compared to 63 patients with spontaneous decline of titers postevacuation of trophoblastic disease. In the postevacuation group there was a 50% probability at 49 days of negative serum titers. All 63 patients had negative titers within 105 days after evacuation.

Chorionic Gonadotropin↗
PubMed1988

Fetal oxygen uptake during uterine contractures.

During contractures there are decreases in fetal oxygen tension. In order to determine if there are concomitant changes in fetal oxygen consumption, we calculated the latter during contractures from measurements of the umbilical blood flow and venous arterial oxygen content differences across the umbilical circulation. There were decreases in both the umbilical venous (from 8.8 +/- 0.2 (SEM) to 8.5 +/- 0.2 ml.dl-1, P less than 0.01) and umbilical arterial (5.9 +/- 0.1 to 5.2 +/- 0.2 mg.dl-1, P less than 0.001) oxygen contents. The umbilical venous-arterial oxygen content difference increased from 2.9 +/- 0.1 to 3.3 +/- 0.2 ml.dl-1 (P less than 0.005). Umbilical blood flow was 194.3 +/- 4.5 ml.min-1 kg-1 during relaxation and was unchanged during contractures. Fetal oxygen uptake increased from 5.7 +/- 0.3 to 6.5 +/- 0.4 ml.min-1 kg-1 (P less than 0.005) during contractures. This observation is consistent with our previous speculation that there is increased muscular activity of tone associated with contractures.

Animals↗
PubMed1988

Use of C-reactive protein to predict the outcome of medical management of tuboovarian abscesses.

Medical management of tuboovarian abscesses (TOAs) has been shown to be successful. However, the ability to predict which patients with TOA would respond to antibiotic therapy could shorten the hospital stay and decrease treatment costs. C-reactive protein (CRP), an acute-phase-reactant protein with a short half-life, was investigated as a possible predictor of response by TOA patients to medical therapy. Twenty-two patients with TOAs were admitted prospectively into this study, which included daily quantitative determinations of CRP. The patients had either resolution of the mass and symptoms (responders), increased evidence of systemic sepsis and acute peritonitis requiring surgery (failures) or continuation of the tender adnexal mass without evidence of peritoneal irritation (persisters). Twelve patients classified as responders showed a continued daily decrease in quantitative CRP levels of at least 20% per day below the previous day's value until the return to normal levels. The five failures showed a progressive rise in CRP levels as well as evidence of systemic sepsis. Persisters showed an initial decrease in the CRP level followed by a leveling off of the value to a decrease of less than 20% per day. The rate at which daily CRP determinations decline may be a useful predictor of the response to antibiotic therapy.

Abscess↗
PubMed1987

Measurement of C-reactive protein to compare ceftizoxime versus cefoxitin/doxycycline therapy for septic pelvis: a preliminary report.

C-reactive protein (CRP), a biological marker of inflammation, may be a useful indicator of therapeutic response in patients with septic pelvis. In a study comparing ceftizoxime and cefoxitin/doxycycline in patients with septic pelvis, quantitative CRP levels were closely correlated with the responses and failures of therapy. The results of this study showed the two antibiotic regimens to be equally effective, with 23 of 25 patients in each treatment group achieving a satisfactory response. The fact that ceftizoxime was effective in four of five patients with Chlamydia trachomatis in cervical isolates suggests that intravenous therapy for the acute infection can be accomplished without the addition of an antichlamydial agent. Upon discharge from the hospital, patients can continue therapy with an oral drug that is specifically active against Chlamydia.

C-Reactive Protein↗
PubMed1987

Cardiorespiratory responses to graded reductions of uterine blood flow in the sheep fetus.

Pregnant sheep were chronically instrumented with fetal and maternal catheters and an inflatable occluder and electromagnetic flow transducer were placed on the uterine artery. Uterine blood flow was reduced for approximately 15 minutes to 25 percent, 50 percent, or 75 percent of control uterine blood flow. Fetal blood gases, arterial blood pressure, heart rate and regional distribution of blood flow (by radioactive microspheres) were measured. With progressive reduction of uterine blood flow there was an increasing degree of fetal asphyxia, as measured by blood gases and acid base state. At moderate degrees of asphyxia the fetus responded by redistribution of blood flow to certain organs, namely heart, brain, and adrenal gland, thus preserving oxygenation of these organs. During the most severe degree of asphyxia induced by reduction of uterine blood flow to 25 percent of control there is a reduction of fetal blood flow due to generalized vasoconstriction of essentially all organs. We hypothesize that this is due to the inability of the vasodilator mechanisms to sufficiently oppose the vasoconstrictor mechanisms. Also, because the oxygen consumption of the "vital" organs would be decreased this can be described as the stage of decompensation.

Animals↗
PubMed1986

Fetal cardiorespiratory changes during spontaneous prelabor uterine contractions in sheep.

Fetal cardiorespiratory changes during spontaneous prelabor uterine contractions (called contractures) were studied in 12 chronically catheterized fetal sheep at 120 to 143 days' gestation. During contractures the carcass blood flow increased significantly from 27 +/- 2 (SEM) to 32 +/- 3 ml/min/100 gm. There were no significant changes in combined ventricular output or in blood flow to the umbilical circulation, brain, heart, adrenal glands, gut, kidney, and lung. Fetal arterial blood pressure increased from 57 +/- 2 to 62 +/- 1 mm Hg (p less than 0.001) during contractions. There were no significant changes in fetal heart rate. In the fetal femoral artery during contractures the oxygen content decreased from 6.1 +/- 0.2 to 5.4 +/- 0.2 ml/dl of blood (p less than 0.001), and carbon dioxide tension increased significantly from 44 +/- 0.4 to 45 +/- 0.4 mm Hg (p less than 0.001). The pH did not change. The increase in carcass blood flow during contractures suggests that there was an increase in fetal skeletal muscular activity or tone. An increase in fetal skeletal muscle activity, together with a decrease in uterine blood flow could explain the small decrease in fetal oxygen content that occurs with each contracture. Fetal compression and/or changes from rapid eye movement to synchronized sleep or arousal observed during contractures are possible stimuli causing increased fetal skeletal muscle tone or activity. Since contractures periodically result in neuromuscular activity in the fetus in its protected fluid-filled environment, they may play a key role in fetal neuromuscular development by stimulating "exercising" in the fetus in utero.

Animals↗
PubMed1985

Clostridium difficile-associated diarrhea follows perioperative prophylaxis with cefoxitin.

Clostridium difficile-associated diarrhea during prolonged therapy of obstetric and gynecologic infections is known to occur with use of all classes of antibiotics except vancomycin and the aminoglycosides. We present 11 cases of C. difficile-associated diarrhea which followed a short course of perioperative prophylaxis with cefoxitin during a 1-year period. Nine of the cases of C. difficile-associated diarrhea were among 162 women who received cefoxitin perioperative prophylaxis for cesarean section or hysterectomy, but none occurred in 85 women who received one of four other antibiotics for perioperative prophylaxis (p = 0.024, Fisher's exact test). The two other occurrences of C. difficile-associated diarrhea following perioperative prophylaxis with cefoxitin were in women who underwent exploratory laparotomy. We conclude that C. difficile-associated diarrhea is related to perioperative prophylaxis with cefoxitin.

Adolescent↗