Shorter latencies of components of middle latency auditory evoked potentials in congenitally blind compared to normal sighted subjects

A previous study which reported shorter latencies of the Nb component of AEP-MLRs in congenitally blind compared to normal sighted subjects, formed the basis for the present study. The blind subjects had received a rehabilitation program from the age of 4 years onwards, which may have influenced auditory function. Hence the present study was designed to compare the AEP MLRs of normal sighted subjects with age-matched blind subjects who had not undergone early rehabilitation. Auditory evoked potentials (0 to 100 ms. range) were recorded in 10 congenitally blind subjects (average age = 22.4 +/- 4.9 yrs.) and an equal number of age-matched subjects with normal vision. There were two repetitions per subject. The peak latencies of both the Pa (maximum positive peak between Na and 35 ms.) and Nb (maximum negative peak between 38 and 52 ms.) waves was significantly shorter in congenitally blind compared to normal sighted subjects. Since the Pa and Nb waves are believed to be generated by the superior temporal cortex (Heschl's gyrus), it appears that processing at this neural level occurs more efficiently in the blind. Also, in spite of the absence of an early rehabilitation program the present subjects showed the same auditory changes as those reported earlier.

Significance of antibody coated bacteria in neurogenic bladder cases

A total of 85 urine samples from 63 patients with neurogenic bladder, were subjected for pus cell counting and culture. Fifty nine (69.4%) samples showing significant bacterial growth were tested for the presence of antibody coated bacteria (ACB). One serum sample per patient was collected for the estimation of C-reactive protein. E. coli was the commonest bacterial isolate (45.8%) from the clinical samples followed by Ps. aeruginosa (20.3%) and K. pneumoniae (18.6%). Thirty two culture positive samples belonging to 27 patients, were found to be antibody coated. Of all the isolates, K. pneumoniae was antibody coated in higher proportion (63.7%) followed by Ps. aeruginosa (58.3%) and E. coli (55.6%). Immunoglobulin G was found in all the ACB positive samples, where as 87.5% of them were also coated with IgA class of antibodies. All patients with ACB in urine had raised serum CRP levels except one, where as all the rest of the patients had CRP level within normal limit. The presence of pus cells in urine and radiological abnormalities in the urinary tract were significantly higher in ACB positive patients than in ACB negative patients.

Differences between congenitally blind and normally sighted subjects in the P1 component of middle latency auditory evoked potentials

Auditory evoked potentials (0 to 100 msec. range) were recorded two times for 9 congenitally blind children (age = 14.1 yr. +/- 1.4 yr) and 9 age-matched children with normal vision. The groups' peak latency and amplitude of the P1 wave were compared. The peak latency was significantly lower for the congenitally blind than for the normally sighted on a two-factor analysis of variance. Since the P1 wave is thought to correspond to either the ascending reticular activating system or the primary auditory cortex, these results suggest that information processing at these neural levels may occur more efficiently in the blind.

Gas-phase halo alkylation of C60-fullerene by ion-molecule reaction under chemical ionization

Chemical ionization (CI) mass spectra of C60-fullerene were studied using 1,2-dibromoethane and 1,2-dichloroethane as CI reagents. The ion-molecule reaction between C60 and C2H4X(+) (X=Br and Cl) leads to the formation of (C60+C2H4X)(+) adducts. The collision-induced dissociation of the adducts reveal gas phase halo alkylation of C60-fullerence involving the C-C bond formation.

Effect of ethanol on hepatic ribosomal proteins and mRNA

Levels of RNA, mRNA and separation of ribosomal proteins from control and ethanol treated rat liver, showed no change in total RNA content, but poly(A+)mRNA was reduced significantly in ethanolic rats. Ribosomal proteins S2, S3a, S3b, S4, L3, L4, L4a, L10a and L15 were found substantially reduced in experimental rat livers. This study suggests decrease in poly(A+) mRNA coupled with loss of ribosomal proteins must be responsible for decreased protein synthesis in chronic alcoholism.

Novel fractionation of proteins using novobiocin as a precipitating agent: application to ribosomal proteins from the archaebacterium Sulfolobus acidocaldarius and Escherichia coli

A fractionation method involving precipitation of proteins with novobiocin has been developed to separate ribosomal proteins of the archaebacterium Sulfolobus acidocaldarius. Four groups of proteins were obtained corresponding to those precipitated with 0.2, 0.5 and 1.0 mg/ml novobiocin and the proteins soluble at 1.0 mg/ml novobiocin. The same procedure was also successful for the fractionation of ribosomal proteins from Escherichia coli. Two dimensional gel electrophoresis showed that proteins present in each group were distinct with only a minor contamination of proteins from other groups. Our results indicate that proteins with similar charge and molecular weight can be separated by this method. This procedure may have applications for the fractionation of other complex protein mixtures.

Haplotypes in tribal Indians bearing the sickle gene: evidence for the unicentric origin of the beta S mutation and the unicentric origin of the tribal populations of India

To determine the origin of sickle cell anemia (SS) in India, we analyzed haplotypes of the beta gene cluster in beta S-carrying individuals belonging to tribal populations living in the Nilgiris region of southern India and complemented the available data on tribes of east-central India. We found that in the Nilgiris tribes chromosomes bearing the beta S gene are linked in 91% of the cases to the "Asian" (Arab-Indian) haplotype (although 25% of the haplotypes had the epsilon polymorphic site negative, making the 5' portion of the haplotype identical with the African Senegal haplotype). These XmnI (+) chromosomes were associated with high G gamma expression (67.2 +/- 5.9%) and a high percentage of Hb F (15.5 +/- 7.9%; range, 6-25.3%). We have similar findings for tribal groups from west-central India (Gujarat). In east-central India we have confirmed the data of others, finding the same haplotype linked to beta S in tribes living in the east (Orissa, Andhra Pradesh). We conclude that the beta S gene in presently isolated and disperse tribal populations in India is associated with one predominant typical haplotype, suggesting a unicentric origin of the mutation in India. In addition, this finding implies a unicentric origin of the tribal populations themselves: The gene must have arisen and spread before tribal dispersion. Furthermore, we find extremely high frequencies of the (-alpha) haplotype in the Nilgiris (0.89) and in Gujarat (0.95). The beta S gene linkage to a high Hb F-expressing haplotype and the high incidence of alpha-thalassemia predict a mild phenotypical expression of sickle cell anemia in India.

Atypical haplotypes linked to the beta S gene in Africa are likely to be the product of recombination

We report here the haplotypes of 10 MstII-defined SS patients and a S/beta o thalassemia from the Central African Republic, exhibiting 7 different atypical haplotypes that are different from the typical Bantu haplotype that characterize over 93% of the beta s bearing chromosomes in that region of Africa. Of the seven atypical haplotypes, six can be easily interpreted as the result of recombination around the "hot spot" 5' of the beta gene, between a typical Bantu haplotype and other haplotypes available in the normal population. Except for one case that requires further study, this result demonstrates that the main mutational event leading to sickle hemoglobin in Bantu-speaking Africa was the mutation of the beta gene in a Bantu haplotype background.