Oxygen mass transfer and scale-up studies in baffled roller bioreactors.

Oxygen mass transfer was studied in conventional, bead mill and baffled roller bioreactors. Using central composite rotational design, impacts of size, rotation speed and working volume on the oxygen mass transfer were evaluated. Baffled roller bioreactor outperformed its conventional and bead mill counterparts, with the highest k(L)a obtained in these configurations being 0.58, 0.19, 0.41 min(-1), respectively. Performances of the bead mill and baffled roller bioreactor were only comparable when a high bead loading (40%) was applied. Regardless of configuration increase in rotation speed and decrease in working volume improved the oxygen mass transfer rate. Increase in size led to enhanced mass transfer and higher k(L)a in baffled roller bioreactor (0.49 min(-1) for 2.2 L and 1.31 min(-1) for 55 L bioreactors). Finally, the experimentally determined k(L)a in the baffled roller bioreactors of different sizes fit reasonably well to an empirical correlation describing the k(L)a in terms of dimensionless numbers.

Oxidation of phenol in a bioremediation medium using Fenton's reagent.

The oxidation of phenol by Fenton's reagent was investigated in a medium suitable for bioremediation. An experimental design approach, based on a central composite rotatable design, was used to quantify the effects of H2O2 concentration (2000 to 5000 mg 1(-1)) and FeSO4.7H2O concentration (500 to 2000 mg 1(-1)). Performance of the chemical oxidation by Fenton's reagent was evaluated by determining the percentage of phenol oxidized at equilibrium. The analysis of variance test indicated that both H2O2 and FeSO4.7H2O concentrations had a positive effect on phenol oxidation. Hydrogen peroxide concentration was the dominating parameter for the removal of phenol by Fenton's reagent. The optimal concentrations of H2O2 and FeSO4.7H2O for complete oxidation of 2000 mg 1(-1) phenol in the medium were found to be 4340 mg 1(-1) and 1616 mg 1(-1), respectively, at 25 degrees C and pH 3. Oxidation of phenol in the culture medium was found to be significantly different than in pure water.

Soil deterioration and the growing world demand for food.

A recent survey of five watersheds in south-central Wisconsin, where corn is now the dominant annual crop, illustrates the soil erosion damage that is occurring on sloping land under modern agricultural technology and prevailing market forces. In 70 percent of the 93 quarter-sections sampled, estimated soil losses, on the average, were more than twice the amounts considered compatible with permanent agriculture. Scattered studies by others indicate that the findings are meaningful for a large area in the United States when row cropping is prevalent on sloping soils. Pressures on cultivated land, in general, are mounting rapidly because of the rising demand for meat in industrialized nations and the soaring numbers of marginally fed people in Third World countries. The world population-food problem makes increasing stress on U.S. soils inevitable in the foreseeable future. Adequate protection against excessive loss of productive topsoil requires that the level of publicly supported soil conservation activities be promptly adjusted to this circumstance.

Batch and continuous biooxidation of sulphide by Thiomicrospira sp. CVO: reaction kinetics and stoichiometry.

Aqueous phase biooxidation of sulphide by the novel sulphide-oxidizing bacterium Thiomicrospira sp. CVO was studied in batch and continuous systems. CVO was able to oxidize sulphide at concentrations as high as 19 mM. Sulphide biooxidation occurred in two distinct phases, one resulting in the formation of sulphur and possibly other dissolved sulphur compounds rather than sulphate, followed by sulphate formation. The specific growth rate of CVO in the first and second phases were 0.17-0.27 and 0.04-0.05 h(-1), respectively. Nitrite accumulated in the culture during the first phase and was consumed during the second phase. The composition of end-products was influenced by the ratio of sulphide to nitrate initial concentrations. At a ratio of 0.28, sulphate represented 93% of the reaction products, while with a ratio of 1.6 the conversion of sulphide to sulphate was only 9.3%. In the continuous bioreactor, complete removal of sulphide was observed at sulphide volumetric loading rates as high as 1.6mM/h (residence time of 10h). Overall sulphide removal efficiency decreased continuously upon further increases in volumetric loading rate. However, the volumetric removal rate increased until a maximum value of 2.4mM/h was obtained at a loading rate of 3.2mM/h. The corresponding sulphide conversion and residence time were 76% and 5.6h, respectively. As expected from the high ratio of sulphide to nitrate loading rates (1.7-1.9 mM/h), no sulphate was formed in the continuous reactor. Using the experimental data the value of maximum specific growth rate, saturation constant, decay coefficient, maintenance coefficient and yield were determined to be 0.36 h(-1), 1.99 mM sulphide, 0.0014 h(-1), 0.078 mmol sulphide/mg ATPh and 0.018 mg ATP/mmol sulphide, respectively.

Esmolol in the treatment of multifocal atrial tachycardia.

Multifocal atrial tachycardia (MAT) is a supraventricular tachydysrhythmia precipitated by a number of pharmacologic and physiologic disturbances. Corrections of these disturbances should take precedence in the treatment of MAT.

Oral acyclovir reduces the incidence of recurrent herpes simplex keratitis in rabbits after penetrating keratoplasty.

To determine if acyclovir sodium prevents postoperative herpes simplex virus type 1 (HSV-1) recurrences, 21 rabbits harboring latent HSV-1 underwent uniocular autograft penetrating keratoplasty. All operated-on eyes were treated with topical and subconjunctival dexamethasone sodium phosphate. Ten of the 21 rabbits also received oral acyclovir (intravenous acyclovir was given at the time of surgery). Postoperatively, 9 (82%) of 11 operated-on eyes in rabbits not treated with acyclovir had positive HSV-1 ocular cultures. In acyclovir-treated rabbits, however, none of the 10 operated-on eyes had positive ocular cultures. In addition, 9 (82%) of 11 of the operated-on eyes had geographic ulcers develop in the non-acyclovir-treated rabbits, compared with 1 (10%) of 10 in the acyclovir-treated rabbits. Finally, stromal keratitis appeared in 5 (56%) of 9 of the operated-on eyes in non-acyclovir-treated rabbits and 1 (12%) of 8 of the operated-on eyes in acyclovir-treated rabbits. The results of this study indicate that acyclovir significantly lowered the incidence of HSV-1 ocular shedding, geographic ulceration, and stromal keratitis in a rabbit autograft penetrating keratoplasty model.

A laparoscopic method for excision of large retroperitoneal paraovarian cysts.

Large retroperitoneal paraovarian cysts often present in reproductive-age women as an adnexal mass, with the appearance of a simple cyst on ultrasound. This report describes a laparoscopic method for removal of large paraovarian retroperitoneal cysts. Use of this technique permits successful removal of these cysts while avoiding laparotomy.

Maternal-fetal correlations in patients with severe preeclampsia/eclampsia.

A prospective pair-controlled study of maternal, cord blood, and neonatal hematologic findings was done in 50 severely preeclamptic/eclamptic and 50 well-matched normotensive pregnancies. There were no neonatal complications in mature infants. Neonatal complications were similar in premature infants of both study and control group; however, neonatal deaths were higher in the study group. In the study group, there was a poor correlation between maternal and cord blood hematocrit (r = .07), platelet count (r = .11), and fibrinogen (r = .05). In addition, there was no correlation (r = .06) between maternal and cord blood thrombocytopenia. Within each subgroup, abnormal neonatal hematologic findings were usually associated with fetal growth retardation, perinatal asphyxia, acidosis, sepsis, or intracranial hemorrhage. The present findings suggest that abnormal hematologic findings described in neonates of severely preeclamptic/eclamptic pregnancies are the result of associated neonatal complications, rather than a direct consequence of preeclampsia.

Comparison of late luteal phase endometrial biopsies using the Novak curette or PIPELLE endometrial suction curette.

The late luteal phase endometrial biopsy is an important part of the evaluation of patients with recurrent spontaneous abortion or infertility. The procedure can be painful and, if an adequate amount of tissue is not obtained, may have to be repeated. In this report, the results of endometrial biopsies performed in the late luteal phase with either the Novak curette or the PIPELLE Endometrial Suction Curette were analyzed retrospectively. The two techniques did not differ in the number of biopsy specimens found to have inadequate tissue for diagnosis; however, patients who underwent biopsy with the PIPELLE recalled significantly less pain associated with the procedure. When used in premenopausal patients undergoing endometrial biopsy during the late luteal phase, the PIPELE provided adequate tissue with preservation of glandular, stromal, and capsular architecture.

Complications of pregnancy in infertile couples: routine treatment versus assisted reproduction.

Ninety pregnancies conceived by infertile couples using assisted reproductive technologies and 86 pregnancies conceived by infertile couples with routine infertility treatment were analyzed to determine the outcome of and the complications experienced during the pregnancies. Pregnancies ending after 24 weeks' gestation were evaluated for the following complications: pregnancy-induced hypertension, diabetes mellitus, preterm labor, premature rupture of membranes, placenta previa, and fetal growth retardation. A matched control group of normal fertile patients admitted to the obstetric service at Vanderbilt University Medical Center was used to compare the incidence of pregnancy complications among the groups. In the group treated by assisted reproduction, 81 pregnancies were singleton and nine were multiple gestations, whereas in the routine group, 84 were singleton and two were multiple gestations. In the group treated by assisted reproduction, 29 of 90 gestations (32%) ended before 24 weeks, compared with 18 of 86 (21%) in the routine group, a nonsignificant difference. Mean birth weight and gestational age were similar among the three groups for singleton gestations. Among multiple gestations, the mean (+/- standard error of the mean [SEM]) birth weights were 2513 +/- 115, 724 +/- 57, and 2282 +/- 132 g in the group treated by assisted reproduction, the group receiving routine methods, and the control group, respectively (P less than .001 when those treated by routine methods were compared with the other two groups). The mean (+/- SEM) gestational ages were 36 +/- 1.2, 26.5 +/- 2.0, and 35.5 +/- 1.2 weeks, respectively (P less than .01 comparing those treated by routine methods and the other two groups).(ABSTRACT TRUNCATED AT 250 WORDS)

Pregnancy outcome in 303 cases with severe preeclampsia.

The purpose of the present clinical investigation was to determine the influence of aggressive management, associated medical/obstetric complications, race, and gestational age on fetal, neonatal, and maternal risks associated with severe preeclampsia. Three hundred and three consecutive pregnancies complicated by severe preeclampsia were studied. All patients were delivered within 48 hours after admission to the perinatal center. In 91 patients the disease was superimposed on chronic hypertension. There was a significant difference between patients with and those without prior chronic hypertension regarding perinatal mortality (32 versus 7.7%), incidence of abruptio placentae (10 versus 4%), and frequency of small-for-gestational-age infants (33 versus 14%). Fifty-one patients (17%) had thrombocytopenia, 26 (8.5%) had hemolysis, elevated liver enzymes and low platelet count syndrome, and 22 (7.3%) had disseminated intravascular coagulopathy. There was significant difference between white and black patients regarding the frequency of thrombocytopenia (28 versus 13%), hemolysis, elevated liver enzymes, and low platelet count syndrome (19.7 versus 5.3%), and coagulopathy (13 versus 1.4%). However, most of this apparent racial difference resulted from higher incidence of abnormal hematologic findings among patients who had conservative management by private physicians before transfer. Perinatal survival was zero when severe preeclampsia developed at or before 28 weeks, whereas it was 100% when disease developed after 36 weeks' gestation. The above factors should be considered in counselling patients with severe preeclampsia.

Selective termination in multiple pregnancies: ethical considerations.

PIP: For those patients who have multiple pregnancies there are several considerations that must be made. When the pregnancies are the result of induced ovulation there is a significant iatrogenic element. Counselling must be provided for couples throughout the entire process. From the beginning of the inductio n program emphasis on the risks associated with multiple gestations must be clearly explained. Such events increase the risk of fetal anomalies, premature births, and poorer outcomes. The alternatives, including selective reduction must be discussed because of these risks. Also, while the patient may recognize the risks of such therapy, it is critical that they be provided with numerous chances to reassess their decision. Thus, informed consent is much broader than merely signing a form. It must be an on going process in which the patient is given any chance necessary to modify the therapy. Further, selective reduction, if it is chosen as an option, must be performed by caring and competent health professionals who are fully cognizant of the ethical and moral issues that are involved with the procedure. It is essential that physicians recognize the fact that abortion is not always something that women plan deliberately or necessarily regard as morally correct. Often times it is viewed as a necessary intervention resorted to only if the alternatives would be worse than the act itself.^ieng

The use of the intravenous glucose tolerance test to evaluate nonobese hyperandrogenemic women.

To better define the association of hyperandrogenemia and insulin resistance, we evaluated nonobese, nonacanthotic hyperandrogenemic women utilizing intravenous glucose tolerance tests (IVGTT). Six women (group 1) all of whom had elevated serum testosterone (T) and were less than 5% above their ideal body weight for height underwent IVGTTs. A control group (group 2, n = 5) with equivalent weight and height but normal levels of T were similarly tested. The T values (normal 0.1 to 0.6 ng/mL) in group 1 (0.93 +/- 0.05 ng/mL, mean +/- SEM) were significantly different from those in group 2 (0.34 +/- 0.03 ng/mL). Area under the curve (AUC) was calculated for the glucose and insulin values. The glucose AUC for group 1 (15,000 +/- 1,100) was not significantly different from the glucose AUC for group 2 (15,853 +/- 788). Interestingly, the insulin AUC for group 1 (3,829 +/- 583) was not significantly different from the insulin AUC for group 2 (2,987 +/- 456). Within group 1, a correlation between serum T and insulin AUC could not be established. We conclude that in these nonobese, nonacanthotic hyperandrogenemic females, although individual variation exists, collectively a significantly increased insulin response to an IVGTT challenge cannot be demonstrated. This data further challenges the concept of androgens being etiologic in insulin resistance.

Development of a method to isolate and culture highly purified populations of stromal and epithelial cells from human endometrial biopsy specimens.

Appropriate endometrial maturation is of paramount importance to achieve reproductive success. Practical and ethical considerations require that in vitro methods be available to evaluate regulation of human endometrial function. Additionally, tissue complexity requires separation of individual cell populations. This report describes an improved method for isolation of endometrial epithelial and stromal cells, using biopsy specimens as a tissue source. Separated cells were obtained using selective enzymatic digestion in conjunction with physical separation procedures. Isolated populations exhibited over 95% homogeneity, ascertained immunocytochemically. Using this system, isolated cells from normal endometrium can readily be obtained for in vitro studies. Within the defined conditions of a culture system, important areas of current concern in the endometrium such as ectopic endometrial growth and implantation can be addressed.

Coculture of mouse embryos with cells isolated from the human ovarian follicle, oviduct, and uterine endometrium.

OBJECTIVE: To examine the specificity of somatic cell support by comparing embryonic development during long-term in vitro coculture with feeder cells derived from the human ovarian follicle, oviduct, and endometrium. DESIGN: Comparative study of murine embryo development and degeneration during 6 days of in vitro coculture. RESULTS: All feeder-cell cultures were beneficial to embryonic development and viability. Few differences were observed between feeder cell types (epithelial or fibroblastic) or cell origin (ovarian follicle, oviductal, or endometrial). Embryos developed to the eight-cell stage in 24 hours whether in coculture (83.6% to 100%) or in media alone (85.2%); however, further development in media alone decreased compared with coculture (15.6% versus 63.4% to 87.7%, plating) and embryo degeneration increased (67.9% versus 5.5% to 19.4%) after 6 days. CONCLUSIONS: [1] Coculture of embryos with human reproductive tract cells is beneficial to embryonic development and viability. [2] Human somatic cell support of murine embryos during long-term in vitro coculture is not tissue specific nor dependent on cell type.

Cycle of conception endometrial biopsy.

Although controversial, the diagnosis of luteal phase inadequacy and its therapy may improve reproductive outcome, but an endometrial biopsy in the cycle of conception (COC) might theoretically interrupt an intrauterine pregnancy. Fifty-four biopsies obtained in the COC were identified, and patient outcome was documented. Eleven (20%) of the 54 women who underwent COC biopsy did not deliver viable infants. Two patients had ectopic pregnancies, and nine had early abortions, including one whose biopsy specimen contained an early implantation site and another with a trisomy 16 fetus. Although COC endometrial biopsy did not appear to increase the incidence of fetal wastage, biopsy information provided no predictive information suggestive of ultimate pregnancy outcome. Because no useful information is gained from a COC biopsy, we recommend either that pregnancy be avoided or a sensitive pregnancy test be employed for detection in a cycle in which a biopsy is to be performed.

Use of individual human follicles to compare oocyte in vitro fertilization to granulosa cell in vitro luteinization.

Granulosa-lutein (G-L) cells from individual follicles aspirated during cycles of in vitro fertilization-embryo transfer were examined after 3 and 6 days in culture. G-L cells from follicles that contained an oocyte that fertilized in vitro were compared with G-L cells from follicles that contained an oocyte that did not fertilize in vitro. Spent culture media was assayed for progesterone at days 3 and 6 of culture and luteinizing hormone/human chorionic gonadotropin (LH/hCG) receptor content of G-L cells was determined at day 6. G-L cell cultures from follicles that contained an oocyte that fertilized in vitro produced significantly more progesterone over 3 and 6 days of culture than those obtained from follicles in which the oocyte did not fertilize. Furthermore, LH/hCG receptor content after 6 days was significantly higher in G-L cells obtained from follicles with fertilized oocytes compared with follicles with unfertilized oocytes. Increased progesterone output and LH/hCG receptor acquisition demonstrate more maturation or "luteinization" by G-L cells aspirated from individual follicles that contain oocytes that fertilized in vitro.

Use of a sensitive urine pregnancy test before endometrial biopsies taken in the late luteal phase.

Endometrial biopsies for evaluation of the luteal phase should be taken within 2 days of the onset of menses. When these guidelines are followed and patients present at least 12 days after the thermogenic shift on BBT, the ICON pregnancy test is extremely rapid, sensitive, specific, and has predictive values close to 100%. If a biopsy is undertaken before this time there may be an increased risk of false negative results (i.e., a decreased sensitivity). The improved technology in urine pregnancy tests has now made it feasible to obtain accurate urine pregnancy tests before endometrial instrumentation with an increased level of confidence. It is recommended that this technology be used in the management of patients undergoing endometrial biopsies in the late luteal phase.

Ureteral abnormalities in women with endometriosis.

High-volume intravenous urography was performed in 63 women with surgically proven endometriosis. Subtle abnormalities were found in 15.9% of these women. No patient had urologic symptoms, and there was no evidence of hydroureter or ureteral obstruction on the IVP. Long-term follow-up study will be required to determine whether or not these lesions will progress and cause ureteral obstruction.

Autologous granulosa cell coculture demonstrates zygote suppression of granulosa cell steroidogenesis.

OBJECTIVE: To determine if embryos can modulate steroid hormone production by luteinized granulosa cells. DESIGN: Granulosa cells obtained from follicular aspirates were cultured alone or in the presence of a two-pronuclear zygote. The production of E2 and P by these cultures was evaluated by RIA. SETTING: In Vitro Fertilization Unit in an academic research environment. PATIENTS: Sixteen women undergoing IVF. INTERVENTIONS: Standard IVF-ET treatment cycle using leuprolide acetate for pituitary desensitization before hMG or urofollitropin for ovarian stimulation. MAIN OUTCOME MEASURES: Estradiol and P concentration in culture media of luteinized granulosa cells alone or granulosa cells cocultured with a two-pronuclear embryo. RESULTS: Both E2 and P production by luteinized granulosa cells was reduced when cultured in the presence of an embryo. CONCLUSIONS: Human embryos secrete a factor that regulates granulosa cell steroidogenesis.