Telescopic lenses and driving

In some states, persons with significantly reduced visual acuity are being licensed to drive while wearing telescopic spectacle lenses (TSL). In order to evaluate possible visual field limitations present with these devices, the peripheral visual fields of a group of normally sighted subjects were measured while they wore TSL. Severely restricted central fields and sizeable ring scotomas were present with all units tested. These result indicate that driving with TSL should be discouraged.     

Infarct sizing with technetium-99m stannous pyrophosphate scintigraphy in dogs and man; relationship between scintigraphic and praecordial mapping estimates of infarct size in patients

The dynamics of changes in serum lipids (free fatty acids, free glycerol, triglycerides, total cholesterol, and phospholipids) were studied in male Wistar rats irradiated in an open experimental field with a daily dose of 15.48 mC.kg.--1 (60 R) up to a total exposure of 774.0 mC. kg.--1 (3,000 R). The resulting changes occurred in several periods. Initial period of 0--7 days included a drop in triglyceride level and a rise in free glycerol, total cholesterol, and phospholipids in both control and irradiated rats. The period of 14--25 days marked the appearance of serum hyperlipaemia. Between 25--50 days, the levels of the different fractions oscillated and existing changes became more pronounced. The general level of serum lipids during continuous gamma-irradiation exceeded that found in controls. Changes in control animals from experimental field reflected the influence of a changed environment. The modifying factor affecting both irradiated and control rats was night fasting prior to sacrificing the animals and, probably, also the presence of an infradian rhythm in some serum lipid fractions.     

Polymerase chain reaction-single strand conformation polymorphism or how to detect reliably and efficiently each sequence variation in many samples and many genes

A simple and fast method with high reliability is necessary for the identification of mutations, polymorphisms and sequence variants (MPSV) within many genes and many samples, e.g. to clarify the genetic background of individuals with multifactorial diseases. We evaluated polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis to identify MPSV in several genes, which are thought to be involved in the pathogenesis of multifactorial autoimmune diseases like multiple sclerosis. The method is based on the property, that the electrophoretic mobility of single-stranded nucleic acids depends not only on its size but also on its sequence. The target sequence was amplified, digested into fragments ranging from 50-200 bp, heat-denatured and analyzed on native gels. The analysis of 55 PCR systems, including a total of 145 fragments demonstrates, that the detection rate of MPSV depends primarily on the fragment lengths. Appropriate dilutions of samples enhances the proportion of ssDNA compared to dsDNA. Changing the gel conditions, glycerol concentrations and/or the addition of urea may increase fragment resolution in some cases. In general, the detection of MPSV is neither influenced by their location within the fragment nor by the type of substitution, i.e. transitions or transversions. The standard PCR-SSCP system described here provides high reliability and detection rates and allows the efficient analysis of many samples and many genes.     

Effects of somatotropin and salbutamol in three genotypes of finishing barrows: blood hormones and metabolites and muscle characteristics

We evaluated the effects of recombinant porcine somatotropin (pST) and the beta-adrenergic agonist salbutamol on plasam endocrine and metabolite profiles and muscle chemistry in three genotypes of growing barrows (n = 96, 139 d old). Treatments were in a 2 x 2 x 3 factorial arrangement, and main effects were pST (0 or 4 mg/d) and salbutamol (0 or 2.75 ppm); the three genotypes including purebred Meishan (M), 1/4 Duroc, 3/4 White composite (D x Wc), and 1/4 Meishan, 3/4 White composite (M x Wc). Individual pigs were injected daily with buffer or pST at 0700 and allowed ad libitum access to a corn-soybean meal diet (1.2% lysine) and water for 33 d. Plasma was obtained 4 h after injection and 3 h postprandially on d 0, 14, and 28 for determination of growth hormone (GH), insulin, IGF-I, glucose, urea N (PUN), NEFA, triglycerides, and cholesterol. Longissimus and semitendinosus samples were obtained, and protein, RNA, and DNA were quantified and loin chop shear force was measured. In general, plasma hormones and metabolites on d 14 and 28 were not affected by salbutamol in the absence of pST, although salbutamol tended to increase d 14 and 28 GH concentrations. Salbutamol lowered plasma IGF-I (d 14 and 28, P < .05), insulin (d 14, P < .01), and NEFA (d 28, P = .07) when pST was administered, although concentrations still exceeded those for control pigs. Salbutamol reduced (P < .05) IGF-I in M and M x Wc pigs, and GH was not changed in M pigs. Meishan pigs had a greater increase in glucose with pST than M x Wc or D x Wc pigs, although the effect was not consistent over time. Individual treatment with pST caused GH, insulin, IGF-I, glucose, NEFA, and triglycerides to be increased and PUN to be decreased on d 14 and 28. Cholesterol on d 14 and 28 was decreased by pST in M pigs, whereas no effects were found in the other genotypes. Muscle protein and RNA were increased by salbutamol and were consistently lowest for M pigs. Furthermore, pST did not affect muscle protein, but it increased RNA more in M pigs than in the others. Overall, pST and salbutamol seemed to act separately and by different mechanisms to alter muscle composition, but blood criteria generally representing fat metabolism (insulin, glucose, NEFA, triglycerides) were interactively affected. Meishan pigs tended to have greater changes in muscle and plasma composition with pST treatment than did M x Wc or D x Wc pigs.