Nucleotide sequence analysis of the L1 loop variable region of hexon gene of fowl adenovirus 4 isolates from India.

Three fowl adenovirus 4 (FAV4) isolates from chicken and one from quail, all from Tamil Nadu, India were analyzed. The L1 loop variable region of hexon gene of these isolates was amplified by PCR and sequenced. The nucleotide sequences (442 bp) and deduced amino acid sequences of the four isolates were compared with those of other isolates of FAV4. The nucleotide sequences of the four isolates had a 98% homology with other Indian isolates and a 96% homology with Belgian and Russian isolates. The amino acid sequences of the four Indian isolates had a more than 98% homology with other Indian isolates and a more than 92% homology with Belgian and Russian isolates. Hence, the variable of L1 loop region of hexon gene was found to be highly homologous in all the FAV4 isolates tested both at nucleotide and amino acid level.

Immunorheophoresis for the diagnosis of infectious bursal disease.

The immunorheophoresis (IR) technique was used for the detection of infectious bursal disease antigen from bursae collected from field cases and experimentally infected chickens. When these results were compared with that of the agar gel immunodiffusion (AGID) test, they showed excellent agreement as determined by kappa value. However, the time taken for the appearance of the precipitin lines was reduced from 14-24 hr in the AGID test to 3-5 hr in the IR technique.

Efficacy of an inactivated oil emulsion vaccine against hydropericardium syndrome in broilers.

Two inactivated vaccines were prepared against hydropericardium syndrome. The vaccine prepared from liver homogenate extracted with chloroform, inactivated with formalin and adjuvanted with liquid paraffin was highly effective against challenge in chickens aged three, five and seven weeks. Seroconversion following vaccination and challenge was assessed by the agar gel immunodiffusion test. The inactivated oil emulsion vaccine was highly effective against the syndrome in both experimental trials and field trials.

Quantitative counter-immunoelectrophoresis for estimation of antibodies to infectious bursal disease virus.

Quantitative counter-immunoelectrophoresis was standardized to detect antibodies to the avian infectious bursal disease virus. This technique correlated well with the conventional quantitative agar gel precipitation test in estimating antibodies to IBDV. The use of blood dried on filter paper as an alternative to serum is discussed. QCIE is simple, easy to perform and faster than QAGP.

Rapid serological profiling by an immunocomb-based dot-enzyme-linked immunosorbent test for three major poultry diseases.

An immunocomb-based dot-ELISA, employing specially designed apparatus, was used to measure the antibody status for the three major poultry diseases--Newcastle disease, infectious bursal disease and infectious bronchitis--in single test sera. Positive samples could be classified into strong, moderate and weak positives by comparison with the colour reaction given by known strong and weak positive serum controls. The simultaneous dot-immunobinding assay gave reproducible results and allowed considerable savings on the cost of reagents compared to liquid ELISA. The antigen-coated immunocomb can be stored under refrigeration and the test can be performed rapidly under field conditions by trained personnel.

Adrenal cortical function and reserve in lepromatous leprosy.

22 chronic Lepromatous Leprosy patients of over 10 years duration, 17 non-reactional and 5 in reactional state who have not taken steroids as part of treatment were selected for the study. Serum cortisol was estimated by Radio-immuno-assay. Samples for basal values were collected at 8.00 A.M. Stimulated values were estimated in samples collected 8 hours after ACTH gel 40 units IM or 2 hours after 0.15 unit/kg BW Plain Insulin I.V. Basal cortisol values are: Normal controls 123.06 +/- 57.33 ng/ml. Non-reactional: 100.47 +/- 30.33 ng/ml; Reactional 141.4 +/- 43.15 ng/ml. Stimulated values are: Normal controls: 207.6 +/- 72.57 ng/ml. Non-reactional: 175.33 +/- 57.07 ng/ml, Reactional: 230 +/- 40.92 ng/ml. Basal serum cortisol in the non-reactional state is slightly lower than in normals but not statistically significant (P greater than 0.1). The basal cortisol in reactional subjects is slightly higher than in normals but not significant statistically (P greater than 0.05). The percentage rise over the basal value after stimulation test is found to be significantly low in both the reactional and non reactional states (P greater than 0.05) and also there is no statistically significant difference between these two groups (p greater than 0.5). Hence it is concluded that the Adrenal cortical reserve is low both in the non-reactional and reactional states of Lepromatous Leprosy.

Methanol-precipitated, detergent-treated Newcastle disease virus as an agar-gel precipitation test antigen.

Methanol-precipitated, detergent-treated (Triton X-100) Newcastle disease virus (NDV) was found suitable as an agar gel precipitation test (AGPT) antigen. One hundred and twenty sera were tested by the haemagglutination-inhibition (HI) test and AGPT against NDV. There was a very significant increase in the proportion of AGPT positive samples with increase in HI titre. Hence AGPT can be recommended as a field based test for seromonitoring following vaccinations against ND where laboratory facilities are inadequate.

Comparison of Newcastle disease vaccines by serology using serum, tears and feather pulp samples.

Seroconversion of 3 lentogenic commercial Newcastle disease (ND) vaccines and experimental V4 vaccines was compared based on the haemagglutination inhibition (HI) test against ND. It was found that for primary vaccination all the vaccines produced similar response but for vaccinations V4 and LaSota were better than RDVF. Eight-five samples each of serum, tears and feather pulp were collected from respective birds and antibody assessment was done against ND by HI test. The geometric mean HI titres (GMT) of serum samples were highest followed by tears and feather pulp samples before vaccination and 3 weeks after vaccination by oculonasal route and the difference was statistically significant (p < 0.01). Three weeks after booster vaccination by oculonasal route, however, the GMT of serum samples were highest followed by feather pulp and tear samples. The ease of collection of feather pulp samples and their role in ND serology is discussed.

Rocket immunoelectrophoresis in the diagnosis of infectious bursal disease.

The rocket immunoelectrophoresis (RIE) test was used for the qualitative detection and quantitative estimation of infectious bursal disease virus (IBDV) specific antigen in experimentally infected chickens and samples collected from suspected outbreaks. The IBDV specific antigen was detected in the bursae of experimentally inoculated chickens up to 5 days post infection (PI) by the agar gel precipitation (AGP) test and 7 days PI by the RIE test. The RIE detected IBDV specific antigen in a significantly greater number of samples collected from the field outbreaks than the conventional AGP test. Exudative bursae were found to have a higher antigen content than haemorrhagic bursae and are recommended as the material of choice for diagnosis of IBD. This test could also be used to quantify IBDV specific antigen in commercial killed vaccines.

Antigenetically unusual Newcastle disease virus from racing pigeons in India.

Newcastle disease virus isolated from an outbreak in racing pigeons in India was found to be velogenic, based on the mean time to death in 10-day-old embryonated hen's eggs, the intravenous pathogenicity index in 6-week-old chickens and the pathogenesis in chickens and pigeons. The virus induced disease in chickens without prior adaptation in chickens. The virus was antigenically unusual since it could not be grouped with the available panel of monoclonal antibodies at the World Reference Laboratory for Newcastle disease, UK. However, commercially available lentogenic and mesogenic vaccines provided 100% protection to chickens against this antigenically unusual NDV.

Efficacy of live adjuvanted mesogenic Newcastle disease vaccine in chickens.

120 white leghorn chickens primed with a lentogenic Newcastle disease (ND) live vaccine at 7 days of age were divided into three equal groups of 8 weeks of age and vaccinated with a live mesogenic ND vaccine (NDV). One group received only Newcastle disease mesogenic vaccine (RDVK) in normal saline, the second group received RDVK with groundnut oil as adjuvant and the third group received RDVK with liquid paraffin as adjuvant. Sera were collected at different time points for the assessment of antibody level against ND virus (NDV) by the haemagglutination inhibition (HI) test. The commonly used non-adjuvanted RDVK could not evince 100% protective HI titre beyond 11 weeks of age but in both the adjuvanted groups 100% protective HI titre was evident up to 20 weeks of age. On challenge at 20 weeks of age both the adjuvanted groups withstood challenge but in the non-adjuvanted group 80% of chickens withstood the challenge. A significant difference in immune response between the adjuvanted and non-adjuvanted groups was seen but not between both the adjuvanted groups. The advantage of vegetable oil (groundnut oil) as an adjuvant for live mesogenic ND vaccine has been discussed.

Estimation of antibodies to Newcastle disease virus in tears.

Micro-haemagglutination inhibition tests (Micro-HI) were used to measure the level of maternal IgG in the tears of chicks and also to measure the levels of HI antibodies in the tears and serum after vaccination with "F" strain of Newcastle disease virus (NDV) and in the face of an outbreak of Newcastle disease. There was a 1.4 fold difference between the maternal IgG concentration in the serum and tears. The ratio of serum IgG to lachrymal IgG after maternal transfer was 4 to 5:1 on day 4 to 9 and decreased to 2.6:1 on day 12 post-hatch. The intra-ocular vaccination of chicks with "F" strain of NDV resulted in the highest titre of HI antibodies in the tears though there was no significant difference in the response of chicks vaccinated through intranasal, oral and intravenous routes. In the face of an ND outbreak, the level of HI antibodies in the tears during the acute phase was very high and persisted at the same level for 14 days.

Postvaccinal immune response to regimens of Newcastle disease vaccination by filter paper sampling technique.

Seven hundred and ten blood samples were collected at random from commercial layers in Tamil Nadu on Whatman filter paper No. 1 instead of the conventional method of serum collection. The birds were subjected to different Newcastle disease (ND) vaccination schedules and samples were collected to study the vaccinal response to ND at field level. Eluates were obtained from sample areas of filter paper using Brij-35 solution [detergent] and subjected to the micro haemagglutination inhibition (HI) test for ND antibodies. The HI titre ranged from less than 2(4) to 2(9). The possible causes of poor immune response to ND vaccinations are discussed.

Pathogenicity and immunosuppressive properties of infectious bursal disease virus field isolates and commercial vaccines in India.

The pathogenicity and immunosuppressive properties of two field isolates of infectious bursal disease. virus (IBDV) and five commercial IBDV live virus vaccines marketed in India were evaluated in this study. The pathogenicity of the wild type viruses and vaccines were based on mortality, the bursa:body weight ratio and microscopic lesions in the bursa in 3-week-old chicks that received these viruses. The immunosuppressive effects of these viruses were evaluated by measuring the antibody responses to sheep red blood cells, Brucella abortus plain antigen and Newcastle disease virus (NDV) vaccine in one-day-old chicks. One field isolate (N35/93) was found to be more pathogenic and immunosuppressive than the other (N45/92) while none of the commercial mild Lukert type vaccines were found to be pathogenic. One of the vaccine strains marked as Mild Lukert type was highly immunosuppressive; one was moderate and one could be classified as mild. Both the intermediate vaccines tested were highly immunosuppressive.

HLA Bw57 and DR7 association with psoriasis vulgaris in south India.

Eighty-three south Indian patients with psoriasis vulgaris were studied for HLA antigen frequencies and compared with 77 controls studied simultaneously. HLA Bw57, a split of B17 was found elevated in the patients. The two sexes differed in their age-at-onset curves: females had a preponderance to early onset of the disease, while the males had late onset. Among these patients, major group 3, a Western Brachycephal Armenoid group, revealed the highest risk for B17 & Bw57 but not major group 2, a Mediterranean one.