Hepatitis-B surface antigen and antibody: prevalence and persistence in institutionalized and noninstitutionalized persons

A total of 426 persons were studied in an attempt to more clearly define the high prevalence of hepatitis-B surface antigen (HBsAg) seen among institutionalized persons. HBsAg was found in 63.4 percent of the children and young adults with Down's syndrome (DS) at the Central Wisconsin Center (CWC) and in 45.5 percent of those at the Northern Wisconsin Center (NWC). Significantly more subjects with DS had hepatitis-B antigenemia than age- and sex-matched non-DS institutionalized subjects. Antibody (anti-HBs) to HBsAg was found in 19.5 percent of the DS subjects at CWC and in 38.6 percent of those at NWC. The prevalence of anti-HBs was similar among DS and non-DS institutionalized subjects. None of the noninstitutionalized subjects had HBsAg in their serums and their anti-HBs prevalence was low (2.1 percent). HBsAg was found to persist for at least 10 years in both DS and non-DS institutionalized subjects. However, persistence occurred more frequently among DS subjects. Anti-HBs persisted at least 10 years among non-DS subjects, but DS subjects tended to lose antibody sooner. The study findings indicated that the high prevalence of HBsAg seen in institutionalized DS subjects at CWC and NWC were not related to the age of the subject at admission nor to the duration of institutionalization.

Serologic studies of the maize stalk rot pathogen Erwinia carotovora f. sp. zeae

With the help of serological techniques, namely microprecipitin, agglutination, and gel diffusion, sixteen isolates of maize stalk rot pathogen were proved to be identical. Serological techniques have thus been utilized as an additional tool for identifying the pathogen Erwinia carotovora f. sp. zea. It was also established that the pathogen does not perpetuate in the seed, either externally of internally. It could, however, be found through serological tests that infected ears carried the pathogen and transmitted it as a contaminant to the healthy seeds.

A study of Cytomegalovirus, Epstein-Barr virus and Herpesvirus hominis (types 1 and 2) antibody in institutionalized and non-institutionalized children

In an attempt to demonstrate differences in antibody prevalence between free-living and institutionalized children, antibodies to Cytomegalovirus (CMV), Epstein-Barr virus (EBV), and Herpesvirus hominis (HVH), types 1 and 2, were assayed in 123 children. The children comprised three groups consisting of 41 institutionalized patients with Down's syndrome (all non-disjunctive trisomy-G karyotype and equal numbers of age-, sex-, and race-matched non-mongoloid institutionalized subjects and non-institutionalized normal controls. CMV antibody titer values were statistically similar in the three groups. However, fewer mongoloids (21.9%) were seropositive than other institutionalized retardates (39.0%) and normal control subjects (43.9%). Antibody titer values to EBV were also similar; however, in comparison to the other groups, significantly more mongoloids were seropositive at younger ages. More mongoloids were seropositive to HVH-1 and had higher antibody titers than the other two groups. Antibody to HVH-2 was more prevalent in institutionalized subjects, 85.4% in mongoloids and 65.8% in other institutionalized retardates, than in normal non-institutionalized children (26.8%).

Application and standardization of various procedures for inoculation of maize by Erwinia carotovora f. sp. zeae

Hypodermic syringe and toothpick methods were best for evaluating pathogenicity of the maize plant against Erwinia carotovora f. sp. zeae, both in glass house and in the field. The portion of the stalk above the ground was best suited for reproducing the disease symptoms. Leaf and leaf whorl did not show any rotting hero. Seed inoculation showed least mortality percentage. Root inoculation was suitable only for young seedlings. Cotyledons, as an organ for inoculation for getting best reproducible infection, were not at all suitable.

Studies on certain aspects of chemical control of bacterial stalk rot disease of maize

Sandoz seed dressing 6335 showing high efficacy in checking the growth of the maize stalk rot pathogen Erwinia carotovora f. sp. zeae Sabet in culture. Brestan, Antracol, Difolatan, Aratan, Duter, Ceresan wet, Flit-406, Cuman, Blitox-50, Streptocycline, Agrimycin, Terramycin, Actidione, Aureomycin, Chloromycetin, Penicillin G, and Streptomycin were moderately effective. The rest of the 35 chemicals was negligible in its influence. 15 different chemicals, namely Agrimycin, Streptocycline, Chloromycetin, Sodium penicillin G, Actidione, Terramycin, Aureomycin, Sandoz seed dressing 6335, Antracol, Aratan, Blitox-50, Diflotan-80, Ceresan wet, Cuman and Brestan 60 could also control the disease, but only when the plants were treated in vivo immediately after inoculation. They could not show any effectiveness, however, after 24, 48, and 72 hours of inoculation, showing their failure to control, once the infection has taken place by the pathogen.

Bacterial stalk rot of Maize, its symptoms and host-range

Stalk rot of maize, caused by Erwinia carotovora f. sp. zeae Sabet (re-designated as Pectobacterium chrysanthemi pathovar. zeae by KELMAN 1974) showed first premature withering and drying up of the uppermost leaves which was soon followed by the lower leaves. The rot either extended from the base upwards (basal rot) or from the top downwards (top rot). In the case of basal rot, the leaves become yellow and the infected tissue becomes brown, soft, and water soaked. Internally, the stalk turns into a soft mass of disintegrated tissue. At this stage the plants usually topple over. A foul odour, accompanied with the presence of dipterous larvae on and in decaying tissues, are the characteristic symptoms of this disease. With the advance of the disease the stalk finally dries up into a conglomeration of dry and shredded or disjointed fibrous tissue. The top rot begins with wilting and drying up ot the tips of middle leaves of the whorl. A decay that continues rapidly spreads downwards throughout the stalk and the affected plants soon droop. The host range studies were suggestive of the fact that the maize pathogen, apart from causing the disease on maize, could produce soft rot in potato, carrot, onion, sugarbeet, sweet potato, papaya, cabbage, and many other plants and could also infect Sorghum vulgare, Pennisetum typhoidium, tobacco, and tomato.

Reaction of patients towards the evening OPD services in hospitals of Delhi

The Evening O. P. D. services were started in six major hospitals of Delhi as a consequence of its successful running in one hospital. The present study was undertaken to assess the reactions of the beneficiaries of this service in terms of the content of service, the nature and type of care that is provided and its usefulness. With the help of an interview schedule, a random sample of 155 evening OPD patients which was drawn from these governmental hospitals, it was found that this service was grossly underutilised. There were many, reasons but in the main these were non-availability of supportive services, and non-availability of senior doctors in the evening OPD. Lack of proper publicity of this service in the city and the lack of additional resources required to man this service in the evening hours were also highlighted. The administrators of the hospitals were cautious to publicise this service in the public for want of additional resources.

Isolation of La Crosse virus (California encephalitis group) from the chipmunk (Tamias striatus), an amplifier host

La Crosse (LAC) virus was isolated from the blood of seven chipmunks (Tamias striatus) captured during the summer of 1970 in southwestern Wisconsin. With the exception of the original isolate obtained from human brain after fatal encephalitis, these represent the first known isolations of LAC virus from a naturally infected free-living vertebrate. The chipmunks were trapped and periodically recaptured in two study areas where 59 chipmunks became infected and developed neutralizing antibody during the summer cycle of virus transmission. All isolates were obtained from blood samples collected within a 7 week period between 11 July and 23 August, and all were from seronegative chipmunks; 6 of these were recaptured and found to be seropositive 2 to 3 weeks later. The isolates proved identical to each other in comparative micro-neutralization tests using BHK21 cell cultures and immune chipmunk serum or hyperimmune mouse ascitic fluids. Neutralization tests showed the isolates to be different from snowshoe hare, trivittatus, and Jamestown Canyon prototype virus strains but indistinguishable from the LAC prototype. Findings demonstrate multiplication and transmissibility of LAC virus in a naturally infected host and are consistent with the thesis that chipmunks are important amplifying hosts for LAC virus and that Aedes triseriatus mosquitoes serve as vectors in transmitting their infections. Ecological significance of the findings are discussed in regard to current perspectives.

Observations on a natural cycle of La Crosse virus (California group) in Southwestern Wisconsin

Ecological studies were conducted to document the role of the eastern chipmunk (Tramias striatus) as a vertebrate host for La Crosse (LAC) virus in nature during late summer when Aedes triseriatus mosquitoes are most abundant. Movement, home range and density of chipmunk populations were determined by trap mark and recapture techniques on grid study areas. The temporal distribution of A. triseriatus was estimated by use of oviposition traps. Passive antibodies were found in spring-born juveniles captured prior to mid-July and in summer-born juveniles in September. Active antibodies neutralizing LAC virus were first detected in susceptible chipmunks in mid-July and 68 free-living and 4 sentinel animals developed antibodies during the study. Virus transmission continued at a high rate through August but was not detected in September. Chipmunk habitat was ranked for quality and populations of chipmunks. A. triseriatus were more abundant in study areas with most suitable chipmunk habitat. Populations of A. triseriatus were temporally associated with the elaboration of antibodies in chipmunks. In one study area, antibody prevalence rates in adult and spring-born juveniles reached 100% by September. Findings implicate A. triseriatus as the vector and establish chipmunks as important amplifying hosts in discontinuous foci of virus transmission.

The interconversion of glycine and serine by plant tissue extracts

1. Extracts prepared from a variety of higher-plant tissues by ammonium sulphate fractionation were shown to catalyse the interconversion of glycine and serine. This interconversion had an absolute requirement for tetrahydrofolate and appeared to favour serine formation. 2. The biosynthesis of serine from glycine was studied in more detail with protein fractionated from 15-day-old wheat leaves. Synthesis of [(14)C]serine from [(14)C]glycine was not accompanied by labelling of glyoxylate, glycollate or formate. 3. The synthesis of serine from glycine was stimulated by additions of formaldehyde, and [(14)C]formaldehyde was readily incorporated into C-3 of serine in the presence of tetrahydrofolate. 4. The results are interpreted as indicating that serine biosynthesis involves a direct cleavage of glycine whereby the alpha-carbon is transferred via N(5)N(10)-methylenetetrahydrofolate to become the beta-carbon of serine.

Pathways for the metabolism of glyoxylate and acetate in germinating fatty seeds

Cotyledons of germinating sunflower, pumpkin, linseed, and watermelon seeds and the endosperm of germinating castor bean seeds have been examined for their ability to utilize glyoxylate-C14and acetate-C14for the biosynthesis of amino acids. All of the tissues examined readily utilized these acids when supplied in micromolar amounts to tissue slices. The chief products of this utilization included the organic acids of the glyoxylate and tricarboxylic acid cycles and a number of amino acids and amides. The results are interpreted as indicating that, in sunflower, watermelon, linseed, and pumpkin seeds, malate formed in the malate synthetase reaction is metabolized by the partial reactions of the tricarboxylic acid cycle. α-Ketoglutarate produced by these reactions is extensively utilized in the biosynthesis of glutamate, γ-aminobutyrate, and glutamine. In agreement with data already published, castor bean endosperm utilized acetate for the biosynthesis of sugars. This tissue also utilized glyoxylate for the formation of glycine, serine, glycollate, and malate. It is concluded that, with the exception of castor bean endosperm, acetyl CoA arising as a result of fatty acid oxidation might be utilized for amino acid biosynthesis via the partial reactions of the glyoxylate and tricarboxylic acid cycles.