Electron microscopical tracers in the uterine epithelium of the pregnant guinea-pig

Horseradish peroxidase and lanthanum nitrate were used in pregnant guinea-pigs as electron dense tracers to determine whether the 'permeability' characteristics of the uterine epithelium support the hypothesis that immunoglobulin G gains access to the uterine lumen by transepithelial diffusion. Horseradish peroxidase was injected intravenously in eight animals in experiments ranging from 1-43 min and directly into the uterine lumen in five animals in experiments of 1-8 min duration. Lanthanum nitrate was injected only into the uterine lumen of eight animals for exposures of 1-8 min. Horseradish peroxidase did not traverse the junctional complexes regardless of injection site; lanthanum nitrate did not penetrate the complexes either except in one animal. We conclude that the uterine epithelium is a barrier that prevents the diffusional transfer of IgG from mother to fetus. Further studies are required to locate the site where maternal IgG is transferred to the uterine lumen.     

Reading skills and auditory processing ability in children with chronic otitis media in early childhood.

The effect of recurrent middle ear disease during the first 2 years of life on auditory perceptual skills and reading ability was examined in two groups of 6- and 7-year-old children who were pair-matched by age, gender, socioeconomic status, and receptive vocabulary. Group 1 consisted of children with documented chronic otitis media at an early age, and group 2 had no history of middle ear problems. Tests of auditory perceptual skills and reading ability were administered. Significant differences in performance on all tests of auditory processing ability and reading ability were noted.     

In vivo placental permeability to hydrophilic solutes as a function of fetal weight in the guinea pig

The permeability of the placenta was measured with unlabelled inulin in unanaesthetized guinea pigs. Inulin was injected into the sows and the plasma concentrations were recorded at regular intervals. The inulin contents of the conceptuses were calculated from fetal weights, fetal plasma inulin concentrations and a measured inulin distribution volume of 180 ml/kg fetus. From fetal inulin contents and the time integral of the difference in maternal and fetal plasma concentrations, we calculated a mean inulin permeability of 29 +/- 9 (s.e.m.) nl/s per gram placental weight. The inulin permeability per gram placental weight rose statistically significantly with increasing fetal weight. Comparison with a similar rise observed for the smaller cyanocobalamin molecule studied previously led to the conclusions that in the last ten days of gestation the transplacental passages narrow while at the same time there are apparent changes in the numbers and/or lengths of these passages that suffice to increase the unrestricted permeability fourfold.     

Fetal lamb ventricles respond differently to filling and arterial pressures and to in utero ventilation

Right and left ventricular function were investigated in 12 fetal lambs (127-140 days gestation) instrumented with electromagnetic flow sensors on the ascending aorta and the main pulmonary artery, and with vascular catheters. Nine fetuses were equipped with a postductal aortic occluder and the trachea was cannulated in eight. Control arterial blood values were pH 7.36 +/- 0.02 (SD), PCO2 49.3 +/- 2.3 torr, PO2 18.4 +/- 1.7 torr, and hematocrit 37.3 +/- 4.4%. Biventricular function curves relating stroke volume to mean right and left atrial pressure were generated by rapid withdrawal and reinfusion of fetal blood. Both function curves were composed of steep ascending and plateau limbs that intersected at a breakpoint. Stroke volumes at the breakpoints were 0.94 +/- 0.19 ml.kg-1 and 0.63 +/- 0.15 ml.kg-1 for right and left ventricle, respectively (p less than 0.001). During postductal aortic occlusion, arterial pressure increased by 19.3 +/- 7.9 torr while right ventricular stroke volume decreased by approximately 48% and left ventricular stroke volume decreased by approximately 9%. In utero ventilation increased arterial pressure, heart rate, PO2, and oxygen content. Right atrial pressure increased from 3.9 +/- 1.3 to 5.8 +/- 2.9 torr (p less than 0.05); left atrial pressure from 3.5 +/- 1.5 to 10.0 +/- 4.4 torr (p less than 0.05). Aortic flow nearly doubled (112 +/- 29 to 211 +/- 35 ml.min-1.kg-1) (p less than 0.05), and the left ventricular function curve shifted upward. The right ventricular function curve was shifted downward during ventilation. We conclude that the fetal ventricles differ significantly in their outputs, response to changes in arterial pressure, and to the onset of in utero ventilation.     

Gardnerella vaginalis in prepubertal girls

A prospective study was established to determine the significance of the isolation of Gardnerella vaginalis from the vagina in prepubertal children. Two hundred fifty-six children were enrolled. Group 1 consisted of 137 children who had been victims of sexual abuse; group 2, forty-eight children with genitourinary complaints and no history of sexual abuse; and group 3, seventy-one children with no genitourinary complaints and no history of sexual abuse. Gardnerella vaginalis was isolated from 20 patients (14.6%) in group 1 and five (4.2%) of 119 control patients from groups 2 and 3. Within group 1, G vaginalis was more likely to be isolated from children with a history of multiple episodes of sexual abuse than those with a single episode. Gardnerella vaginalis was not associated with any other historical, physical, or laboratory findings, including vaginal erythema or vaginal discharge.