Sero-Negative Systemic Sclerosis: A Rare Presentation.

Systemic Sclerosis is a multisystem disease associated with progressive fibrosis of skin and internal organs. It is diagnosed by presence of characteristic clinical findings and is supported by specific serologic abnormalities. ANA is positive in case of systemic sclerosis in 90 percent of cases. We report a rare case of this rare disease where patient was ANA, Antitopoisomerase I (anti-Scl-70), Anticenteromere antibody negative.

Recurrent severe anaemia: a rare presentation of parvovirus b19 infection.

Secondary pure red cell aplasia is usually seen in immunocompromised hosts or patients who have chronic haemolytic anaemia, which is caused by blood transfusion related transmission. The present patient, a 30-year-old immunocompetent female, presented several times with recurrent severe anaemia, over a period of one and half years. Her history, clinical examination and investigations did not reveal any indigenous drug intake, previous blood transfusions, haemolytic disorders, myeloproliferative disorders, pregnancies, autoimmune diseases or thymoma. She was found to have a thalassaemia minor trait, on the basis of which severity and recurrence of anaemia could not be explained, and on further evaluation, she was diagnosed to have acute aplastic crisis caused by Parvovirus B19 induced, acquired pure red cell aplasia. The co- existence of these two haematological disorders in an immunocompetent, non-transfusion dependent individual is rare, which makes our case report unique.

Peripheral arterial disease and digital gangrene: a rare presentation of diabetic hand syndrome.

Digital gangrene in upper limbs may be due to systemic sclerosis, trauma, connective tissue disorders, vasculitic disorders and various myeloproliferative disorders or as a part of tropical diabetes hand syndrome which follows trauma. Peripheral arterial disease in diabetics commonly involves lower limbs. The present case, 45-year-old diabetic, presented with dry gangrene in fingertips of both hands for last two weeks without any history of trauma or lower limb gangrene. On examination and workup of the patient was found to have bilateral upper limb arterio-occlusive disease involving ulnar vessels as a macrovascular complication of diabetes mellitus. This presentation of diabetic hand syndrome is very, very rare, hence being reported.

Mouse model of haemorrhagic septicaemia: dissemination and multiplication of Pasteurella multocida B:2 in vital organs after intranasal and subcutaneous challenge in mice.

Haemorrhagic septicaemia (HS) is an endemic disease of bovines, occurring in most tropical regions of Asia and Africa. In the present study, the suitability of using mice to study pathogenesis of HS was assessed using mortality, mean death time and bacterial multiplication in vital organs after infection with live P multocida. Mice were infected with 10(5), 10(3) and 10(1)cfu of P. multocida B:2 via intranasal and subcutaneous routes along with control groups. Bacterial multiplication in lung, liver and spleen of mice were determined at 24 h interval after intranasal and subcutaneous challenge. More than 80 % of challenged mice died within 48 h of inoculation, irrespective of the dose and route of inoculation. A heavy bacterial load (up to 10(8)cfu) was observed in lung, liver and spleen of mice titrated at 24 h and following death of mice. Results of the present study indicate that even ten bacteria are enough to cause mortality in mice and the organism multiplies rapidly in respiratory epithelium and disseminated to other vital organs viz liver and spleen suggesting the important role of mouse model in investigating the pathogenesis and challenge studies during vaccine development.

Mucosal immunization provides better protection than subcutaneous immunization against Pasteurella multocida (B:2) in mice preimmunized with the outer membrane proteins.

To investigate the effect of boosting immunity via mucosal route vis-a-vis parenteral route in the mouse model of haemorrhagic septicaemia, mice preimmunized with OMP of Pasteurella multocida (B:2) were immunized with 10(2) cfu of P. multocida via intranasal and subcutaneous routes. Mice were challenged through intranasal route (natural route of infection) with 10(8) cfu 14 days after immunization. Group of mice which were immunized intranasally showed significant protection (P < 0.05) of 88% as compared to 50% protection in group of mice immunized subcutaneously. In the control group of mice, 100% mortality occurred within 48 h. of challenge. The results of present study indicated that boosting of immunity via mucosal route in mice preimmunized with OMP provided better protection against P. multocida. This study may have implications for developing better vaccination strategies for the natural host.

Immunogenicity of iron-regulated outer membrane proteins of Pasteurella multocida B:2 in mice model.

The present study was conducted to investigate the role of iron-regulated outer membrane proteins (IROMP) of Pasteurella multocida B:2 in mice as potential immunogens. Outer membrane proteins extracted from P. multocida B:2 grown under normal (OMP) and iron-deficient (IROMP) conditions were subjected to discontinuous SDS-PAGE. Nine polypeptides of MW ranging from 85.1 to 16.7 kDa from OMP preparations and two additional polypeptides of MW 95.4 and 89.1 kDa from IROMP preparations were observed with bands of MW 37.2 and 34.7 kDa as major proteins. Mice were immunized twice with OMP, IROMP-enriched fractions and whole cell lysate (WCL) via subcutaneous route at day 0 and 21. Antibody titers were determined from sera collected at weekly interval and protection was studied against challenge using 10(2) cfu of P. multocida two weeks after secondary immunization via intranasal and subcutaneous routes. IROMP and OMP immunized mice provoked significant antibody responses and IROMP induced higher antibody responses. IROMP and OMP immunized mice showed protection (100%) upon intranasal challenge and a protection (84%) following subcutaneous challenge as compared to high mortality (84%) in control mice. These results indicate that OMP enriched with IROMP fractions can be superior means of immunization.

The MHC-haplotype influences primary, but not memory, immune responses to an immunodominant peptide containing T- and B-cell epitopes of the caprine arthritis encephalitis virus Gag protein.

In this report, we describe a short peptide, containing a T helper- and a B-cell epitope, located in the Gag protein of the caprine arthritis encephalitis virus (CAEV). This T-cell epitope is capable of inducing a robust T-cell proliferative response in vaccinated goats with different genetic backgrounds and to provide help for a strong antibody response to the B-cell epitope, indicating that it may function as a universal antigen-carrier for goat vaccines. The primary immune response of goats homozygous for MHC class I and II genes showed an MHC-dependent partitioning in rapid-high and slow-low responses, whereas the memory immune response was strong in both groups, demonstrating that a vaccine based on this immunodominant T helper epitope is capable to overcome genetic differences.

Early and transient induction of nitric oxide (NO) in infectious bursal disease virus infection is T-cell dependent: a study in cyclosporin-A treated chicken-model.

The level of nitric oxide (NO) in the supernatants of mitogen (PHA) stimulated lymphocyte cultures from infectious bursal disease (IBD) virus infected T-cell suppressed and immune competent chickens was monitored. The immune competent chickens when infected with IBD virus showed 4-6 folds increased levels of NO as compared to uninfected chickens. The levels of NO in T-cell suppressed chickens were comparable to uninfected control chickens, in spite of markedly increased hemorrhage suggesting that the muscular hemorrhage observed in IBD in not solely and directly related with NO production. The immune suppressed chickens that did not induce NO production after IBD virus infection showed more severe lesions and supported enhanced virus replication. Taken together it may be suggested that NO production after IBD virus infection, may exert antiviral effect since the immune-suppressed chickens that failed to induce NO showed more severe disease and higher magnitude of virus replication, but does not seem to correlate with the hemorrhagic lesions which in fact may be as a result of the net outcome of various host-factors and the determinants responsible for virus virulence and virus clearance.

Infiltration by CD4+ and CD8+ lymphocytes in bursa of chickens infected with Infectious Bursal Disease Virus (IBDV): strain-specific differences.

In order to investigate if there is any definite correlation between the degree of T-cell response in the bursa of Fabricius (BF) and the virulence of Infectious Bursal Disease (IBD) virus strains, chickens were infected with strains of different virulence i.e. mild (Lukert strain), intermediate (Georgia strain) or invasive intermediate (IV-95 strain). At various times post-inoculation, bursal samples were collected to study virus specific histopathological lesions, the distribution of viral antigen and the extent of T-cell infiltration in the bursa. Most severe bursal lesions were induced by IV-95 strain (the invasive intermediate strain), whereas Lukert, the mild strain caused the least severe lesions. The number of virus positive cells in the bursa was highest in chickens infected with IV-95 strain. Substantial infiltration of CD4+ and CD8+ T-cells in the bursal follicles of virus-infected groups was observed from 4 d.p.i. onwards. The magnitude of T-cell response was more in the birds infected with intermediate (Georgia) or invasive intermediate strains of virus than chickens inoculated with mild (Lukert) strain, even when 10-fold higher doses of the inoculums were used. PHA responses to peripheral lymphocytes were found suppressed in all the groups of chickens only transiently. The results indicate that the magnitude of T-cell responses in BF during IBDV infection is influenced more by the virulence of virus strain rather than the quantum of viral load in BF. Over all these studies may have implications in understanding the role of T-cells in pathogenesis and immunity in IBD.