The Relation between Perinatal Conditions and Developmental Outcome in Low Birthweight Infants: Comparison of Two Cohorts

ABSTRACT. We have compared the relations between perinatal conditions and developmental outcomes at age four years for two cohorts of children with birthweights 2 300 g or less, who did not develop cerebral plasy—one from Southeastern Wisconsin (children born 1975-76) and the other from Copenhagen (children born 1980-82). We examined the general effects of parental education and socioeconomic status, the use of Cesarean section, the degree of prematurity and neonatal complications on outcome. The methods of latent path structural analysis were used to form two models among 15 latent variables: one for children from Copenhagen and a similar model for children from Wisconsin. The impact of parental education and socioeconomic status was somewhat greater in Wisconsin. Several neonatal complications were related to outcome in Wisconsin: the early condition of the infant, use of a respirator, pneumothorax, and anemia/apnea. The only neonatal complication with a significant relation to outcome in Copenhagen was pneumothorax and to a much lesser degree major germinal layer haemorrhage. The degree of prematurity per se had a greater impact in Copenhagen. The use of Cesarean section and mechanical ventilation in the smallest infants was much more frequent in Denmark, but no association could be shown between this increased use and improved developmental outcome.     

The Use of in vitro Fertilization to Detect Reductions in the Fertility of Male Rats Exposed to 1,3-Dinitrobenzene

The Use of in vitro Fertilization to Detect Reductions in theFertility of Male Rats Exposed to 1,3-Dinitrobenzene. HOLLOWAY,A. J., MOORE, H. D. M., AND FOSTER, P. M. D. (1990). Fundam.Appl. Toxicol. 14, 113–122. 1,3-Dinitrobenzene (DNB) isan intermediate chemical in the manufacture of dyes and explosivesand its toxic effects include specific damage to the Sertolicells of the testis. This investigation determined the effecta toxic insult to Sertoli cells had on the functional capacityof developing germ cells as assessed by in vitro fertilization.Male rats were given a single, oral dose of 5, 15, or 25 mgDNB/kg. At selected times after treatment, spermatozoa recoveredfrom the cauda epididymidis were tested for fertilizing capacityusing in vitro fertilization techniques and the testicular responseto DNB was determined by histologica] examination. Treatmentwith 15 and 25 mg DNB/kg resulted in substantial exfoliationof germ cells between 0.5 and 3.5 weeks after exposure and againafter 4.5 weeks; seminiferous tubules which were not depletedshowed signs of disrupted spermatogenesis. Reduced sperm fertilizingcapacity in vitro was observed from 1.5 to 5 weeks and between7.5 and 8.5 weeks after treatment with 15 and 25 mg DNB/kg.There were slight, but significant, reductions in fertilityat 3, 5.5, 7.5, and 8.5 weeks after dosing with 5 mg DNB/kg.These data suggested that DNB did not affect all Sertoli cellsequally, but acted in a stage-specific manner. Stages III, IV,XII, and XIV were most vulnerable to the toxicant Germ cellsassociated with an affected Sertoli cell were usually sloughedoff, resulting in lowered fertility at the time when these cellsshould have reached maturity in the epididymis. The extent ofthe testicular lesions and the loss of fertility were dose dependent.This investigation confirmed the use of in vitro fertilizationto detect the effects of testicular toxicants.     

EFFECTS OF PROPRANOLOL ON THE RESPONSE OF HUMAN ECCRINE SWEAT GLANDS TO ACETYLCHOLINE

Summary.— Propranolol had no marked effects on the acetylcholine-induced sweat response in normal subjects. The only effects were (1) a slight and transient prolongation of the secretion; (2) a very slight and transient anti-cholinergic activity. These findings do not support the existence of a β-receptor inhibitory mechanism affecting sweat gland activity as postulated by Hemels (1970).