Regulated spacing of synapses and presynaptic active zones at larval neuromuscular junctions in different genotypes of the flies Drosophila and Sarcophaga

Synapses at larval neuromuscular junctions of the flies Drosophila melanogaster and Sarcophaga bullata are not distributed randomly. They have been studied in serial electron micrographs of two identified axons (axons 1 and 2) that innervate ventral longitudinal muscles 6 and 7 of the larval body wall. The following fly larvae were examined: axon 1--wild-type Sarcophaga and Drosophila and Drosophila mutants dunce(m14) and fasII(e76), a hypomorphic allele of the fasciclin II gene; and axon 2--drosophila wild-type, dunce(m14), and fasII(e76). These lines were selected to provide a wide range of nerve terminal phenotypes in which to study the distribution and spacing of synapses. Each terminal varicosity is applied closely to the underlying subsynaptic reticulum of the muscle fiber and has 15-40 synapses. Each synapse usually bears one or more active zones, characterized by dense bodies that are T-shaped in cross section; they are located at the presumed sites of transmitter release. The distribution of synapses was characterized from the center-to-center distance of each synapse to its nearest neighbor. The mean spacing between nearest-neighbor pairs ranged from 0.84 microm to 1.05 microm for axon 1, showing no significant difference regardless of genotype. The corresponding values for axon 2, 0.58 microm to 0.75 microm, were also statistically indistinguishable from one another in terminals of different genotype but differed significantly from the values for axon 1. Thus, the functional class of the axon provides a clear prediction of the spacing of its synapses, suggesting that spacing may be determined by the functional properties of transmission at the two types of terminals. Individual dense bodies were situated mostly at least 0.4 microm away from one another, suggesting that an interaction between neighboring active zones could prevent their final positions from being located more closely.     

Hemispheric interactions are different in left-handed individuals.

In a previous study, N. Cherbuin and C. Brinkman (2006) showed that in right-handed participants, interhemispheric transfer time (measured with A. T. Poffenberger's, 1912, paradigm) was a significant predictor of the efficiency of hemispheric interactions (measured with a split visual field, letter-matching task). No effect was found for degree of handedness in this study. This was surprising because handedness has been shown to be associated with differences in the morphology and the structure of the corpus callosum, and cerebral anatomical lateralization, as well as functional lateralization both in behavioral and scanning studies. Because these findings were found in a large sample, but one limited to right-handed participants, the aim of the present study was to determine whether a similar relationship was present between interhemispheric transfer time and hemispheric interaction in left-handed participants (using identical measures) and to assess whether the analysis of a larger sample that comprised both left- and right-handed participants might reveal an effect of handedness. Results demonstrate significant handedness effects, suggesting that left-handed individuals tend to have more efficient hemispheric interactions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Seroconversion of a trivalent measles, mumps, and rubella vaccine in children aged 9 and 15 months

The serological response to MMR vaccine was evaluated in 109 9-month-old infants having no history of measles vaccination, and in 98 15-month-old children who had received monocomponent measles immunisation at 9 months. The combined vaccine contained Schwarz, Urabe Am9, and Wistar RA 27/3 live attenuated virus strains. Preimmunisation antibody levels were extremely low for the 9-month-old children, indicating that maternally-transmitted antibodies do not persist at this age. In the case of mumps, preimmunisation antibody levels were significantly higher in the 15-month-old than in the 9-month-old group. A difference between groups in terms of postimmunisation antibody titres was observed only for rubella, with titres being significantly higher in the older group. Seroconversion rates were high in both groups and no serious events attributable to vaccination were observed. The MMR vaccine can thus be administered to children as young as 9 months of age. Evidence for the efficacy of a two-dose schedule, i.e. at 9 and 15 months, is presented.     

Neurotoxicity of CI-980, a novel mitotic inhibitor

PURPOSE: To compare the simulated keratometric results of the PAR CTS and the EyeSys corneal imaging systems with Javal keratometer readings in keratoconus eyes, in eyes after corneal grafting, and in healthy eyes. SETTING: Cornea Service, Wills Eye Hospital, Philadelphia, Pennsylvania, USA. METHODS: This prospective study evaluated 69 patients divided into three groups (keratoconus; 6 to 12 months postkeratoplasty; normal corneas) treated at the cornea service. The eyes were measured with each of the three instruments. Keratometry results and number of attempts needed to obtain the results were collected. RESULTS: Thirty keratoconus, 18 transplanted, and 21 normal corneas were examined. The PAR CTS Imaged all corneas and the EyeSys, 86% (P = .000627). The PAR CTS and Javal flat and steep K-readings in all three groups were the same. The EyeSys simulated keratometry results were lower than those of Javal keratometer in the flat K (P < .00001) and steep K (P < .00001) in the normal group and in the steep K in the transplanted cornea group (P = .00823). The EyeSys also measured less astigmatism than the Javal in the normal (P = .00124) and transplanted cornea groups (P = .00376). CONCLUSION: The PAR CTS was better able than the EyeSys to provide keratometric values that agreed with those obtained with the Javal keratometer.     

Do the isocyanate monomer standards still protect against attacks of occupational asthma? Should a standard including polyisocyanates be evolved?

Field surveys of diisocyanates at the workplaces in Switzerland and particularly in car repair shops, where HDI was the most used, showed that the monomer levels comply with the Swiss permissible exposure limit (PEL) in the great number of situations. Cases of medical surveillance associated with industrial hygiene measurements demonstrate that occupational asthma was also observed in situations where the monomer concentrations are low although high peaks of prepolymers are often recorded. From the statistical data on compensations, the annual incidence of occupational asthma over the period 1988 to 1992 remains around 54 cases with a mean cost of 21,000 sFr. per case per year. It is suggested that a PEL on the prepolymers should be introduced in the Swiss PEL list to enhance the efficiency of prevention policy.     

Cavernous haemangioma of the iris in a leprosy patient

We report a case of a male infant who presented with congenital anomalies and was found to have a de novo deletion in the terminal region of the long arm of chromosome 9. He died at the age of 17 weeks of cardiorespiratory failure owing to RSV positive bronchiolitis. A review of previously published reports documented one previous report of a patient with a deletion of (9)(q34.3) and multiple congenital anomalies. Comparison with the previously reported case suggests that the phenotype observed constitutes a clinically recognisable pattern of malformations.     

In vitro and in vivo gene delivery mediated by a synthetic polycationic amino polymer

The r?le of chemotherapy in the treatment of operable soft tissue sarcomas is still debatable. In high-grade tumors, randomized trials using adjuvant chemotherapy have resulted in controversial results. A recent meta-analysis showed a higher median disease-free survival in groups with chemotherapy compared to controls. Doxorubicin, ifosfamide and dacarbazine are the majors drugs. Their combination in adjuvant treatment is currently being investigated. Neoadjuvant chemotherapy has allowed conservative surgery in initially unoperable tumors, but its role in primarily operable tumors remains to be defined.     

Contraceptive knowledge, contraceptive use, and self-esteem among Navy personnel

This study evaluated the sexual knowledge (including contraceptive and reproductive knowledge), contraceptive use, and self-esteem among a sample of 158 male and female United States Navy sailors assigned to Navy ships. In spite of the fact that men and women viewed themselves as relatively knowledgeable with respect to contraception, results showed substantial knowledge deficits. Women demonstrated significantly greater sexual knowledge than men, and contraceptive/ reproductive knowledge was highly correlated with self-reported use of contraceptives. Finally, self-esteem was highly correlated with sexual knowledge and certain contraceptive use behaviors.     

Axonal injury alters alternative splicing of the retinal NR1 receptor: the preferential expression of the NR1b isoforms is crucial for retinal ganglion cell survival

Cellular-specific splicing of the retinal NMDAR1 receptor (NR1) and expression of NMDAR2 receptor (NR2) subunits in response to optic nerve injury was investigated by in situ hybridization in adult rats. A controlled optic nerve crush led to a clear alteration in the expression of alternatively spliced NR1 variants in the retinal ganglion cell layer (GCL). The NR1-2b and NR1-4b isoforms were preferentially expressed between 2 d and 1 week after injury, whereas expression for all other isoforms remained either unchanged or decreased to barely detectable levels within 4 weeks. Cellular silver grain density for NR2 subunits also declined in the GCL after trauma. To directly test the hypothesis that NR1b expression is crucial for cell survival after axonal trauma, we administered intraocularly an antisense oligonucleotide against the NR1b isoform 2 and 3 d after injury. This led to a drastic loss of retrogradely labeled retinal ganglion cells (RGCs). Antisense targeting clearly reduced retinal NR1 protein levels, as judged by Western blot analysis, but had no effect on the cell number in control retinas. These findings point toward injury-specific changes in alternative splicing of the NR1 receptor, which are crucial for the survival of RGCs after partial axonal trauma. We therefore propose that this reflects an adaptive, rather than a pathogenic, cellular response to neurotrauma.