Studies on the developmental toxicity of ozone: Postnatal effects

Pregnant rats were exposed to either 0, 1.0, or 1.5 ppm ozone during either mid gestation (Days 9–12) or late gestation (Days 17–20). The dams were allowed to deliver and the early morphological and behavioral development of their pups was monitored. Both exposure regimens transiently reduced neonatal growth rates. The late gestation exposure regimen produced retardations in early reflex development and in open field behavior. Finally, several males from this exposure regimen remained permanently stunted in growth.     

Growth in the width and length of the dental arch in children with unilateral cleft lip and cleft palate]

A study of casts of the dentitions of children with cheilognathopalatoschisis made over an extended period emphasizes that the development and the growth of the maxillary dental arch in width and length are considerably reduced as compared to children without clefts. Consequently, therapeutical measures must be taken to maintain the length and width of the maxillary dental arch.     

Orthodontic Findings in the Deciduous and Early Mixed Dentition—Inferences for a Preventive Strategy

AIM AND METHOD: The aim of the present epidemiologic study was to obtain representative basic data on the frequency, extent and age-dependence of malocclusions in the deciduous and early mixed dentition. The developmental tendencies of specific malocclusions were investigated from the aspect of orthodontic prevention. The collective comprised 8,864 preschool and school-aged children, of whom 1,225 were in the deciduous dentition (mean age 4.5 years) and 7,639 in the mixed dentition (mean age 8.9 years). The orthodontic data were clinically assessed as sagittal, transversal, or vertical single-arch and occlusal findings. In addition, the malocclusions were classified according to their primary symptoms. Early infantile habits, tongue dysfunctions, speech defects and incompetent lip closure were registered separately. RESULTS: 57% of the children were found to have malocclusions, with the frequency rising statistically significantly in dependence on age from the deciduous to the mixed dentition (p < or = 0.001). The mean extent of excessive overjet increased significantly from the deciduous to the mixed dentition. Crossbite with mandibular midline discrepancies were observed significantly more frequently in the deciduous dentition. Although the frequency of anterior open bite underwent a significant decline from the deciduous to the mixed dentition, open bite was the malocclusion most frequently associated with dysfunction in both groups. The significant increase in traumatic deep bite in the mixed dentition indicates an unfavorable developmental tendency in this anomaly until after the eruption of the permanent incisors. CONCLUSION: The need for preventive orthodontic therapy and for the intensified application of interceptive and early treatment measures is stressed in view of the high number of malalignments and malocclusions in the deciduous and mixed dentition and the tendency for some forms of malocclusion to deteriorate as the dentition develops.     

Hamster challenge potency assay for evaluation of Mycoplasma pneumoniae vaccines.

A hamster immunization challenge assay described in the accompanying paper (M. F. Barile, D. K. F. Chandler, H. Yoshida, M. W. Grabowski, R. Harasawa, and S. Razin, Infect. Immun. 56:2443-2449, 1988) was used to examine protection against Mycoplasma pneumoniae disease by passive immunization and to evaluate the protective potency of a Formalin-inactivated whole-cell and a cell extract M. pneumoniae vaccine. Passive immunization with a globulin fraction of hyperimmune mule antiserum to M. pneumoniae provided hamsters some protection against the challenge. When hamsters were actively immunized, a single dose of Formalin-inactivated vaccine provided only minimal protection, whereas multiple doses of this vaccine, particularly when combined with adjuvant, provided good protection. A single dose of the cell extract vaccine did not protect animals, but two doses caused a marked reduction of disease when a priming dose was given intraperitoneally, followed by a booster dose intratracheally. The correlation between the level of metabolism inhibition antibodies to M. pneumoniae in the sera of vaccinated hamsters and the degree of protection as measured by reduction of lung pathological scores and colonization was poor, indicating that seroconversion rates for metabolism inhibition antibodies are not by themselves adequate to measure the potency of M. pneumoniae vaccines.     

Results of external beam radiation for children with retinoblastoma: a comparison of two techniques

From 1979 through 1987, 82 children with retinoblastoma were treated with primary external beam therapy, to one or both eyes. A total of 120 eyes were irradiated, with doses from 3850-5000 cGy. We used a lens-sparing electron beam technique from 1979 to 1984 and a modified lateral beam technique from 1984 to 1987. Comparison of outcome for eyes with Group I-III (Reese-Ellsworth) disease revealed a significant advantage for freedom from relapse favoring the lateral technique (p = 0.0009). A similar trend was noted for final eye outcome (need for enucleation). No differences were noted for eyes with Group IV-V disease. Patient survival was 90% at 4 years, with a mean follow-up time of 36 months.     

Influence of cyclic 3',5'-adenosine monophosphate and adenosine on vascular reactivity.

cAMP, 5'-AMP and adenosine in doses of 1, 2 and 5 mg/kg i.v. in rats diminish vascular resistance in the hind limbs in vivo and in isolated limbs perfused with nutrient fluid containing adrenaline (A) (10(-3) M), slowing action of the heart and lowering blood pressure. After administration of cAMP, 5'-AMP and adenosine (5 mg/kg), vasoconstricting action of noradrenaline (NA) and A was depressed, and the vasodilating action of isoprenaline (I) was enhanced. The changes in blood pressure observed after administration of the tested adenosine compounds were not blocked by phentolamine, but after I were blocked by propranolol. cAMP, 5'-AMP and adenosine had no influence on the drop in blood pressure elicited by acetylcholine. The results indicate that cAMP, 5'-AMP and adenosine increase reactivity of beta-receptors of the sympathetic system in the blood vessels and modify the action of catecholamines on blood vessels.     

Drug-protein conjugates--V. Sex-linked differences in the metabolism and irreversible binding of 17 alpha-ethinylestradiol in the rat

Sex-linked differences in the disposition, biotransformation, excretion and irreversible binding of [6, 7-3H]17 alpha-ethinylestradiol [( 3H]EE2) in Wistar rats have been observed. Three hours after i.v. administration of [3H]EE2 (5 micrograms/kg) the livers of males contained twice as much 3H-labelled material as those of females. The biliary metabolites were largely glucuronides in both sexes, but males also excreted arylsulphates. The principal metabolites liberated from biliary conjugates by enzymes were 2-hydroxyEE2 and 2-methoxyEE2 in females and males, respectively. Biliary elimination of 3H over 3 hr was slightly greater in males (P less than 0.05). Radiolabelled material was irreversibly bound to hepatic microsomal and soluble protein. The material bound to microsomes represented 0.24 +/- 0.07% (mean +/- S.D.) of the dose in males and 0.56 +/- 0.10% in females (P less than 0.001). Oxygenation of the steroid D-ring was not indicated, and 2-hydroxyEE2 appears to be the precursor of the reactive metabolite. The metabolic basis of the sex-linked difference in irreversible binding is discussed.     

Peripheral retinal neovascularization in diabetes mellitus

The cases of seven patients with diabetes mellitus and peripheral proliferative retinopathy (retinal neovascularization at or anterior to the equator) were studied. Associated abnormalities found included systemic arterial hypertension in five, a positive fluorescent treponemal antibody titer in four, and benign monoclonal gammopathy, intravenous drug abuse and hemoglobin AS each in one patient. The presence of additional systemic diseases should be suspected in diabetic patients with predominantly peripheral proliferative retinopathy.