Safety restraints for children travelling in motor vehicles

The parents of 202 children were questioned about their use of safety restraints for their children while they were passengers in a motor vehicle. The result of the survey shows a low incidence of use of safety restraints by both parents and their children and that the type used for children was, in the majority of cases, both inadequate and dangerous. There was a correlation between the use of safety restraints by both parent and child on the day of questioning, but no association was found between the use of these restraints and the social class, educational standard achieved, income group, home language or home province of the parents. Neither was there any association between the use of safety restraints and a history of previous traffic accidents which had involved the family or close friends. In South Africa, the number of deaths in childhood as a result of motor vehicle accidents exceed those from the same cause in the United Kingdom. We consider that the medical profession in this country should inform the public of the desirability of fitting and using safety restraints of the correct type for children while they are passengers in motor vehicles. Reasons for the high incidence of serious injuries to children who are passengers in motor vehicles are reviewed and the methods of restraining children of different ages are discussed.     

Isolation and characterization of a unique glycoprotein from lavage of chicken lungs and lamellar organelles

A major glycoprotein with an estimated molecular weight by sodium dodecylsulfate-acrylamide gel electrophoresis of 36,000 daltons has been found in lavage material of normal chicken lung. Amino acid and carbohydrate analyses of this glycoprotein indicated the presence of hydroxyproline, a high percentage of glycine, sialic acid, mannose, galactose, fucose, and glucosamine. Threonine is the NH2-terminal residue of the glycoprotein. A similar glycoprotein of the same molecular weight, NH2-terminus, amino acid, and carbohydrate composition has been found in lamellar organelles isolated from normal chicken lung. The data indicate that this unique collagen-like glycoprotein, which is similar to a major alveolar glycoprotein found in mammals, including patients with alveolar proteinosis, is also a major protein of avian airways. Because avian airways contain no Clara, ciliated, or goblet cells but do contain type II cells as the only secretory airway cells with lamellar organelles, it is likely that in birds this glycoprotein may be a product of type II cells.     

Combined molecular genetic studies of chromosome 22q and the neurofibromatosis type 2 gene in central nervous system tumors

Monosomy of chromosome 22 or deletions of 22q have been described in meningiomas and astrocytic tumors, the incidence of which is increased in Type 2 neurofibromatosis. Recently, the gene for neurofibromatosis Type 2 (NF2) has been identified at Chromosome 22q12, and a tumor suppression role has been suggested. Because there have been only a few studies of the NF2 gene on central nervous system tumors other than vestibular schwannomas, we investigated the potential role of NF2 as a tumor suppressor gene in a group of sporadic meningiomas and astrocytomas. Forty-four tumors (26 meningiomas and 18 astrocytic tumors of different grades) were screened for NF2 mutations for the entire 17 exons by the polymerase chain reaction-single-strand conformation polymorphism method. In addition, 37 tumors and their respective constitutional deoxyribonucleic acid were analyzed for loss of heterozygosity of 22q alleles by four polymorphic microsatellite markers. Seven inactivating mutations were found in Exons 4, 5, 6, and 10 in 7 of 26 (27%) meningiomas, but none were found in astrocytic tumors. Altogether, 69% of meningiomas and 20% of astrocytic tumors revealed a loss of heterozygosity of 22q markers. All tumors with NF2 mutations showed concurrent loss of alleles on 22q, thus fulfilling Knudson's criteria for tumor suppressor genes in meningiomas. We conclude that inactivation of the NF2 gene is involved in the pathogenesis of a proportion of meningiomas but not in astrocytic tumors. Because many meningiomas and some astrocytic tumors had allelic loss of 22q but intact NF2, there is a possibility that other tumor suppressor genes exist on 22q and may be involved in the pathogenesis of central nervous system tumors.     

Percutaneous transhepatic endoscopic electrohydraulic lithotripsy of biliary tract calculi after orthotopic liver transplantation

The development of biliary tract calculi after orthotopic liver transplantation presents a unique clinical problem. Previously described techniques for removing biliary stones by shock wave lithotripsy, litholytic therapy with oral bile acids, and endoscopic mechanical extraction may be ineffective or contraindicated in liver transplant patients. For this reason, percutaneous transhepatic electrohydraulic lithotripsy (EHL) was performed using an 11 French flexible ureteroscope in two pediatric patients who developed biliary tract calculi following orthotopic liver transplant. There were no complications and postoperative follow-up over 4 years has been uneventful. To our knowledge, these represent the first reported cases of percutaneous transhepatic endoscopic EHL to fragment biliary tract stones in a transplanted liver, which for us has been a safe and effective therapeutic option.     

Rabbit beta-globin is extended beyond its UGA stop codon by multiple suppressions and translational reading gaps

Translational reading gaps occur when genetic information encoded in mRNA is not translated during the normal course of protein synthesis. This phenomenon has been observed thus far only in prokaryotes and is a mechanism for extending the reading frame by circumventing the normal stop codon. Reading frames of proteins may also be extended by suppression of the stop codon mediated by a suppressor tRNA. The rabbit beta-globin read-through protein, the only known, naturally occurring read-through protein in eukaryotes, was sequenced by ion trap mass spectrometry to determine how the reading frame is extended. Seven different proteolytic peptide fragments decoded by the same sequence that spans the UGA stop codon of rabbit beta-globin mRNA were detected. Three of these peptides contain translational reading gaps of one to three amino acids that correspond to the UGA stop codon site and/or one or two of the immediate downstream codons. To our knowledge, this is the first reported example of the occurrence of reading gaps in protein synthesis in eukaryotes. This event is unique in that it is associated with bypasses involving staggered lengths of untranslated information. Four of the seven peptides contain serine, tryptophan, cysteine, and arginine decoded by UGA and thus arise by suppression. Serine is donated by selenocysteine tRNA, and it, like the other tRNAs, has previously been shown to suppress UGA in vitro in mammals, but not in vivo.     

The IPCS Collaborative Study on Neurobehavioral Screening Methods: V. Results of chemical testing. Steering Group

The goal of the International Programme on Chemical Safety (IPCS) Collaborative Study on Neurobehavioral Screening Methods was to determine the intra- and inter-laboratory reliability of a functional observational battery (FOB) and an automated assessment of motor activity in eight laboratories worldwide. The control data were crucial to the outcome of the studies in terms of sensitivity and reliability of the test measures, which in turn impact on the between-laboratory comparisons of chemical effects. In addition, analyses of control data can aid in determining endpoints that may require modification to improve their sensitivity and reliability. The control data from the eight laboratories were examined in terms of the following parameters: 1) control variability within studies for each laboratory; 2) within-laboratory replicability of control values across studies; 3) within-laboratory stability of control values over the course of testing for a given study; and 4) between-laboratory comparisons of parameters (1), (2), and (3). The analyses indicated considerable differences across endpoints, wherein some measures showed high variability and little replicability, while others were extremely reproducible. Generally, there were similar ranges of variability and replicability of control data across laboratories, although in some cases one or two laboratories were markedly different from the others. The physiological (weight, body temperature) and neuromuscular (grip strength, landing foot splay) endpoints exhibited the least variability, whereas the subjective assessments of reactivity varied the most. These data indicate a reasonable degree of comparability in the data generated in the participating laboratories.