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Transforming growth factor beta s (TGF beta) are a family of multifunctional growth factors that are important embryonic morphogens. Because TGF beta s may regulate the development of epitheliochorial placentas, we investigated the location, expression, secretion, and effects of TGF beta s in bovine placentomes and cell cultures derived from chorionic and endometrial epithelia. Placentomes from early second-trimester pregnancies were examined by immunohistochemistry for TGF beta 1, TGF beta 2, and TGF beta 3, and for TGF beta expression in Northern slot-blots. Effects of TGF beta s were assessed in trophoblastic and endometrial epithelial cell lines by DNA synthesis assays. Secretion of TGF beta s by trophoblastic and endometrial epithelial cells was determined using bioassays. All forms of TGF beta were immunolocalized in bovine placentomes. TGF beta mRNA was expressed in chorioallantois, caruncles, and in cultured trophoblastic and endometrial epithelial cells. Endometrial and trophoblastic cells secreted active and latent TGF beta s, and these cells had a transient proliferative response to all forms of TGF beta. These results indicate that TGF beta s are present at the fetal-maternal interface of the bovine placentome and may promote endometrial and chorionic growth.

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PIP: Modeling the factors affecting the duration of unemployment was found to be influenced by the inclusion of migration factors. Traditional models which did not control for migration factors were found to underestimate movers' probability of finding an acceptable job. The empirical test of the theory, based on the analysis of data on US household heads unemployed in 1982 and employed in 1982 and 1983, found that the cumulative probability of reemployment in the traditional model was .422 and in the migration selectivity model was .624 after 30 weeks of searching. In addition, controlling for selectivity eliminated the significance of the relationship between race and job search duration in the model. The relationship between search duration and the county unemployment rate in 1982 became statistically significant, and the relationship between search duration and 1980 population per square mile in the 1982 county of residence became statistically insignificant. The finding that non-Whites have a longer duration of unemployment can better be understood as non-Whites' lower geographic mobility and lack of greater job contacts. The statistical significance of a high unemployment rate in the home labor market reducing the probability of finding employment was more in keeping with expectations. The findings assumed that the duration of employment accurately reflected the length of job search. The sample was redrawn to exclude discouraged workers and the analysis was repeated. The findings were similar to the full sample, with the coefficient for migration variable being negative and statistically significant and the coefficient for alpha remaining positive and statistically significant. Race in the selectivity model remained statistically insignificant. The findings supported the Schwartz model hypothesizing that the expansion of the radius of the search would reduce the duration of unemployment. The exclusion of the migration factor misspecified the equation for unemployment duration. Policy should be directed to the problems of geographic mobility, particularly among non-Whites.^ieng

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BACKGROUND AND OBJECTIVES: A combined bolus and continuous epidural infusion technique of opioid and bupivacaine mixture has been described, although no pharmacokinetic data for this technique exists. The study documents the plasma concentration profile of epidural alfentanil in parturients using this technique, and evaluates the fetal heart rate tracing for associated changes following opioid administration. METHODS: Twenty-four subjects were randomized to receive epidural alfentanil 500 micrograms in 10 mL 0.125% bupivacaine, group A, or fentanyl 50 micrograms in 10 mL 0.125% bupivacaine, group B, as a bolus dose, followed by continuous infusions of alfentanil 20 micrograms/mL in 0.125% bupivacaine (group A) or fentanyl 2 micrograms/mL in 0.125% bupivacaine (group B) for labor analgesia. Plasma drug levels for each group were examined using repeated measures analysis of covariance. RESULTS: Fetal heart rate tracings were recorded throughout the study and were retrospectively analyzed by a "blinded" perinatologist. Data from fetal heart rate tracings were examined by repeated measures analysis of variance. Mean infusion rates were 9.3 +/- 2.1 mL/hour and 9.6 +/- 1.7 mL/hour for groups A and B, respectively. Mean study duration was 3.7 hours in group A, and 3.0 hours in group B. Low plasma levels precluded analysis of fentanyl data. Group A subjects exhibited stability of drug levels over time. Fetal heart rate tracings in 21 patients demonstrated no changes associated with epidural opioid infusion in either group. CONCLUSIONS: With the dosage regimen used in this study, an initial epidural bolus with continuous infusion technique generates a steady state plasma concentration of alfentanil that is below levels associated with direct respiratory depression.

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BACKGROUND AND OBJECTIVES: This study examines the effect of epinephrine on the time to achieve a T4 sensory level when added to a hyperbaric bupivacaine-fentanyl mixture for spinal anesthesia. METHODS: Sixty-nine healthy parturients scheduled for elective cesarean delivery were randomly assigned to three groups. All patients were given 9 mg hyperbaric 0.75% bupivacaine with 25 micrograms fentanyl. Group 1 received no epinephrine while Groups 2 and 3 received 100 micrograms and 200 micrograms epinephrine, respectively. Injection of the spinal anesthetic solutions was performed with the patient in the sitting position. Immediately after drug administration, patients were placed supine with their heads elevated on a pillow and 15 degrees of left uterine displacement was maintained. Vital signs and sensory levels were obtained every minute for 10 minutes. RESULTS: In Groups 2 and 3, the mean time to T4 sensory level was significantly longer (6.9 minutes and 6.6 minutes, respectively) than in Group 1 (4.6 minutes). As a subset, patients weighing more than 90.8 kg achieved a T4 sensory level faster than did those weighting less than 90.8 kg (3 minutes and 5.1 minutes, respectively), but in both groups epinephrine prolonged the onset time to T4 (5.8 minutes and 7.3 minutes, respectively). Three patients were excluded because of failure to obtain a T4 sensory level. CONCLUSIONS: The onset time to T4 is related inversely to patient weight, and epinephrine (100 micrograms and 200 micrograms) delays the onset of sensory block to T4 when administered with subarachnoid hyperbaric bupivacaine-fentanyl.

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The DNA damage associated with benzo(a)pyrene (B[a]P) and formaldehyde (HCHO) exposure in rat tracheal implants was determined by alkaline filter elution adapted to measure DNA-protein cross-links (DPC) in vivo. In addition, histopathological responses of the tracheal epithelium were quantitated after multiple exposures to 20 micrograms B[a]P and 0.2% HCHO. Compared to either agent alone, combined exposure for 1-4 weeks caused an increase in cellular atypia and greater thickness of hyperplastic and metaplastic lesions. HCHO exposure resulted in a dose-dependent increase in DPC with a maximal response of 85% DNA filter retention at 0.2% HCHO, which were mostly removed by 72 h. B[a]P did not cause DPC, but when tracheas were pre-exposed to 20 micrograms B[a]P followed by 0.05% HCHO there was a 15% decrease in HCHO-induced DPC. This competition between B[a]P and HCHO for sites presumably on DNA does not offer a clear explanation for their markedly enhanced cocarcinogenicity observed in previous studies, but does demonstrate the interaction between the two agents in tracheal epithelium.

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It is known that in speech reception tasks, when performance scores in the auditory-only (A) mode and the visual-only (V) mode are simply added, the result will be substantially less than when eyes and ears can simultaneously process the stimuli (A/V mode). However, it is not known whether the improvement with practice and/or training with feedback is greater in the A+V or the A/V mode. Normal young adults (N:20) watched and listened in the A/V mode and responded to 100 key words in sentences spoken by a man on a 25-inch color TV at a distance of 6 ft, both before and after training with feedback on other lists of 100 key words. In the training condition, half the Ss were given the A mode first, half the V mode. Within the training condition, pre- and post-training test phases of 100 key words each had a training phase intervening in which feedback was given on 100 different key words. Performance significantly improved from 28.8% to 35.0% words correct within the training condition, averaged over A and V mode (6.2%; p less than .001), but it improved from 68.5% to 86.0% (= 17.5%; p less than .001) in the pre- vs post-training comparison for the A/V mode. The difference of 11.3% in favor of the A/V mode was significant (p less than .01). Essentially zero correlation was found between individual improvements in the A+V vs the A/V mode. The acquisition and utilization of A, V, and A/V skills are independent and specific. Each mode may have its optimum set of training conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

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The problem of menstrual dysfunction in women who engage in endurance training for participation in distance running events has been studied. Through survey, selected aspects of the personal, training, menstrual, and contraceptive histories of 168 women who were defined as runners, joggers, or controls were evaluated. In addition, defined subsets of the study subjects were evaluated for serum levels of pituitary and ovarian hormones and determination of percentage body fat. The data show significant differences among the 3 groups. It is concluded that menstrual dysfunction in distance runners is a real phenomenon. Presumably this is related to decreased percentage of body fat and/or minimal ovarian function secondary to diminished hypothalamic or pituitary hormone secretion.

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