Biomedical subjects

N B Singh

Publications and source records attributed to N B Singh.

At least 19 recordsLinked to original sources

PubMed2006

Emergence of sporotrichosis in Manipur.

A retrospective analysis of all cases of sporotrichosis was conducted to examine the pattern and frequency of sporotrichosis cases in Manipur over a period of six year from July 1999 to June 2005. Seventy-three (73) cases of sporotrichosis were detected of which 30 were confirmed by culture and 43 were diagnosed by aspiration cytology only. Most of the patients belonged to the age group of 21 to 40 years (n = 23; 31.5%). There were 39 females (53.4%) and 34 males (46.5%). Commonest site of infection was upper limbs (n = 39; 53.4%) followed by lower limbs (n = 17; 23.2%). Commonest type of infection was lymphocutaneous form (n = 46; 63.1%) followed by fixed cutaneous form (n = 27; 36.9%). Among these 73 cases, 2 male patients (2.7%) were found to be HIV positive. In our experience, collection of material by aspiration of pus or infected tissue was found to be a better method compared to scraping or exudate. This study revealed Manipur as a new endemic area for sporotrichosis.

Adolescent↗

PubMed2003

Schizencephaly.

Explore the source record for details and available documents.

Adolescent↗

PubMed2001

Artemether vs quinine therapy in Plasmodium falciparum malaria in Manipur--a preliminary report.

Qinghaosu and its derivatives are rapidly effective antimalarial drugs derived from a Chinese plant (sweet worm wood). Preliminary studies suggest that these drugs may be more effective than quinine in the treatment of Plasmodium falciparum malaria. A randomised double blind trial was conducted in 52 cases of Plasmodium falciparum malaria cases. In all 26 cases were given artemether and another 26 were given quinine. There were 2 (7.5%) deaths in artemether group and 4 (15%) deaths in quinine group. The parasites were cleared more quickly from the blood in artemether group when compared to quinine group (mean-72 hrs vs 96 hrs). Resolution of fever was comparable in both artemether and quinine group (mean-84 hrs vs 78 hrs) and also the average time of recovery from coma was more earlier in artemether group (mean-60 hrs vs 72 hrs). The only side effect noticed with artemether therapy was gastrointestinal (GI) intolerance while quinine therapy was associated with myocarditis, hypotension, hypoglycemia and GI intolerance.

Adolescent↗

PubMed2000

Mechanisms involved in protective immune response generated by secretory proteins of Mycobacterium habana against experimental tuberculosis.

Live mycobacteria secrete a number of unique proteins early in their multiplication which are important for both the pathogenesis and the stimulation of specific host responses. We have investigated the mechanisms by which the host mounts immune response against tuberculosis after vaccination with secretory proteins (SP) of a vaccine candidate Mycobacterium habana TMC 5135. Mice vaccinated with SP of 10th day growth of M. habana, either alone or emulsified in Freund's incomplete adjuvant (FIA) possessed antituberculous resistance and cellular immune responses against M. tuberculosis H37Rv. These proteins induced a significant cutaneous delayed type hypersensitivity response in guinea pigs vaccinated with heat killed M. tuberculosis H37Rv, which was equivalent to that observed with a standard purified protein derivative (PPD). The splenocytes of these guinea pigs have shown higher proliferative response after stimulation with SP than with PPD. The SP + FIA immunization has been found to exert maximum prophylactic effect by potentiating both the oxygen dependent arms and enzymatic activities of macrophages. Macrophages from mice vaccinated with SP of M. habana produced enhanced levels of interleukin(IL)-2, interleukin-12 and interferon(IFN)-gamma. The protective as well as cell mediated immune responses were upregulated in SP immunized animals when compared to whole cell (M. habana) vaccinated animals. SDS-PAGE of SP from M. habana showed the prominent bands of 60, 32, 31 and 30 kDa. Furthermore, the western analysis of SP with pulmonary tuberculosis patient's serum has revealed the presence of immunoreactive antigens of 36, 35, 33/32 kDa. Overall study demonstrated that the secretory antigens released by actively growing M. habana bacilli could activate different arms of effective immune response.

Acid Phosphatase↗

PubMed2000

HIV-1 subtypes in injecting drug users & their non-injecting wives in Manipur, India.

The presence of HIV-1 antibodies was determined among the injecting drug users (IDUs) and their non-injecting wives. A total of 233 (72%) were found to be HIV-1 seropositive among the 322 subjects recruited in this study between August, 1996 and September, 1997. The distribution of HIV-1 subtypes among the injecting drug users (IDUs) and their wives was determined using peptide enzyme immunoassay (EIA). Sexual transmission of HIV-1 occurred frequently (45%) from HIV-1 infected IDUs to their spouses. The majority of the subjects (167/233) were infected with subtype C followed by subtype Thai B (29/233). Subtype C was the most common among both IDUs (78%) and their wives (57%), followed by subtype Thai B (12% and 13% respectively). The distribution of subtypes was significantly different between IDUs and their wives with a lower percentage of subtype C and higher percentage of subtype D in the infected wives (P < 0.03). Discordance for subtypes transmitted from IDUs to their wives suggests the occurrence of dual and/or recombinant infection in the IDUs.

Female↗

PubMed1999

Involvement of corticosterone in food intake, food passage time and in vivo uptake of nutrients in the chicken (Gallus domesticus).

To evaluate the effect of corticosterone on nutrient transport, 10-week-old male chickens were grouped in 4 categories and treated as follows: sham-operated, adrenalectomised, corticosterone (4 mg/kg injected subcutaneously for 5 d) in both sham-operated and adrenalectomised. The food intake, food passage time and uptake of calcium, phosphorus and glucose were determined by standard procedures. Corticosterone administration to both sham-operated and adrenalectomised groups stimulated significantly higher food intake, delayed food passage time and increased uptake of calcium, phosphorus and glucose, as compared to sham-operated control and adrenalectomised groups. Corticosterone administration increased absorption of these nutrients significantly more in the adrenalectomised group than in the sham-operated controls. Corticosterone also significantly elevated the plasma concentrations of these nutrients. The responses to the hormone were significantly greater in adrenalectomised birds. It is concluded that corticosterone increases food intake and retention and the absorption of calcium, phosphorus and glucose in the alimentary tract.

Adrenalectomy↗

PubMed1998

Cryptosporidium and HIV.

To study the importance of cryptosporidium as a diarrhoea causing pathogen (using stool samples), a cohort study was conducted from 14-9-1994 to 14-3-1995 on injecting drug users in Imphal. Stool samples were also collected from close contacts of the patients of human immunodeficiency virus (HIV) infected cryptosporidium diarrhoea cases and patients of paediatric medicine ward of Regional Institute of Medical Sciences (RIMS), Imphal. A total of 9 cases of cryptosporidium diagnosed out of 11 HIV infected diarrhoea cases and 2 out of 11 personal contacts were found to be positive. Two cases with history of close contacts with HIV infected cryptosporidium diarrhoea cases were not suffering from diarrhoea. One out of 7 paediatric diarrhoea cases was found to be positive. Five out of 9 HIV infected cryptosporidial cases died within one month of diagnosis of cryptosporidium. The remaining 4 had improved and diarrhoea was controlled. One of the 4 did not show cryptosporidium any more in the stool sample.

Adult↗

PubMed1998

Multiple tubercular ulcer perforation of ileum in an AIDS patient: case report.

Intestinal perforation is an extremely uncommon complication of Mycobacterium tuberculosis (MTB) infection. We report a case of HIV infection in a male injecting drug user (IDU) with intestinal tuberculosis complicated with multiple ileal perforations at the Regional Institute of Medical Sciences Hospital, Imphal, Manipur. The emergency surgical therapy supported by antitubercular drugs (ATT) and parenteral nutrition saved the life of this patient who presented in a critical state of shock. The patient manifested with extrapulmonary tuberculosis, which is one of the criteria of AIDS. The authors stress the possibility that in future, tubercular complication till now considered atypical, may become more frequent.

AIDS-Related Opportunistic Infections↗

PubMed1998

Role of antigen specific circulating immune complexes in diagnosis of tuberculosis.

SETTING: Tuberculosis is a public health problem worldwide. Early accurate diagnosis in patients with active disease is essential to reduce morbidity and mortality. Conventional methods for detection of Mycobacterium tuberculosis have given disappointing results. OBJECTIVE: To evaluate the utility of detection of M. tuberculosis antigen in circulating immune complexes (CIC) for the diagnosis of tuberculosis. METHOD: Eighty-four clinically diagnosed cases of mainly extra-pulmonary tuberculosis, 85 patients with diseases other than tuberculosis and 30 healthy controls, were evaluated for the presence of antigen of M. tuberculosis in CIC in serum using sandwich enzyme linked immunosorbent assay (ELISA). RESULTS: In total, 22 out of 84 cases were positive for culture on Lowenstein Jensen medium; 76.5% (n = 65) of the clinically diagnosed patients (including 20 culture-positive cases) were found to be positive by ELISA. The difference in mean absorbance values of ELISA in cases of tuberculosis was significantly higher than in controls. The sensitivity of ELISA was 90.9% and the specificity was 93.04%. CONCLUSION: Detection of M. tuberculosis antigen in CIC by ELISA has potential as a useful diagnostic tool for the rapid diagnosis of tuberculosis, especially extra-pulmonary forms where results of conventional methods of diagnosis are disappointing.

Animals↗

PubMed1997

Lymphostimulatory and delayed-type hypersensitivity responses to a candidate leprosy vaccine strain: Mycobacterium habana.

Lymphostimulatory and delayed-type hypersensitivity (DTH) immune responses to a candidate antileprosy vaccine Mycobacterium habana have been quantified in inbred AKR mice. M. habana vaccine in three physical states, live, heat-killed and gamma-irradiated, was given intradermally to separate groups of mice and after 28 days these mice were given subcutaneous challenge with heat-killed M. leprae and heat-killed M. habana in the left hind footpad. Live BCG vaccine alone and in combination with gamma-irradiated M. habana were also compared similarly. A sufficient degree of DTH response was generated in mice by M. habana vaccine in all physical forms against two challenge antigens (lepromin and habanin). The BCG combination with M. habana did not increase the DTH response indicating internal adjuvanticity endowed in M. habana. The active hypersensitivity of immunized mice was transferable to syngeneic mice by the transfer of sensitized cells from the donor to the recipient mice intravenously. M. leprae-infected Rhesus monkey PBMC have shown comparable stimulatory response with M. habana (sonicate), and M. leprae (sonicate) antigens. The possibility of developing M. habana as a candidate antileprosy vaccine is discussed.

Animals↗

PubMed1996

A major T-cell-inducing cytosolic 23 kDa protein antigen of the vaccine candidate Mycobacterium habana is superoxide dismutase.

This study describes the purification and immunochemical characterization of a major 23 kDa cytosolic protein antigen of the vaccine candidate Mycobacterium habana (TMC 5135). The 23 kDa protein alone was salted out from the cytosol at an ammonium sulfate saturation of 80-95%. It represented about 1.5% of the total cytosolic protein, appeared glycosylated by staining with periodic acid/Schiff's reagent, and showed a pl of approximately 5.3. Its native molecular mass was determined as approximately 48 kDa, suggesting a homodimeric configuration. Immunoblotting with the WHO-IMMLEP/IMMTUB mAbs mc5041 and IT61 and activity staining after native PAGE established its identity as a mycobacterial superoxide dismutase (SOD) of the Fe/Mn type. The sequence of the 18 N-terminal amino acids, which also contained the binding site for mc5041, showed a close resemblance, not only with the reported deduced sequences of Mycobacterium leprae and Mycobacterium tuberculosis Fe/MnSODs, but also with human MnSOD. In order to study its immunopathological relevance, the protein was subjected to in vivo and in vitro assays for T cell activation. It induced, in a dose-related manner, skin delayed hypersensitivity in guinea-pigs and lymphocyte proliferation in BALB/c mice primed with M. habana. Most significantly, it also induced lymphocyte proliferative responses, in a manner analogous to M. Ieprae, in human subjects comprising tuberculoid leprosy patients and healthy contacts.

Amino Acid Sequence↗

PubMed1996

Identification of a 25-kilodalton protein of Mycobacterium bovis BCG to distinguish BCG strains from Mycobacterium tuberculosis.

Mycobacterium bovis BCG vaccine strains were compared with Mycobacterium tuberculosis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. A 25-kDa protein observed in the BCG strains was absent in M. tuberculosis. Rabbit antibodies specific to the 25-kDa protein uniquely identified this protein in BCG strains but not in M. tuberculosis. It is suggested that the 25-kDa protein and polyclonal antibodies directed against this antigen can be exploited to distinguish BCG strains from M. tuberculosis.

Antibodies, Bacterial↗

PubMed1995

HIV-2 strikes injecting drug users (IDUs) in India.

Manipur, a north-eastern state of India bordering Myanmar, observed introduction of HIV-1 among fairly large number of IDUs in October 1989, followed by rapid spread within the next 6 months. HIV-2 in injectors was not present until recently, though it was detected from other parts of India in 1991. This communication reports for the first time presence of HIV-2 among young injectors of Manipur. All the HIV-2 infected IDUs were also found to be infected with HIV-1. HIV-2 has affected a large number of people in Africa through heterosexual transmission. It remains to be seen whether HIV-2 spreads rapidly also among the drug-injecting population of Manipur. Observation of the disease progression among HIV-2 infected IDUs will also be of interest.

Acquired Immunodeficiency Syndrome↗

PubMed1995

The 65 kDa protein of Mycobacterium habana and its putative role in immunity against experimental tuberculosis.

Mycobacteria including Mycobacterium tuberculosis and Mycobacterium leprae possess multiple antigens some of which inhibit other anti-mycobacterial immune responses. Whole cell vaccines are not free from these suppressive molecules and may adversely affect the immunogenic response(s). Purified protein components having only immunogenic properties should prove to be superior vaccine(s). Mycobacterium habana, a candidate vaccine for mycobacterial infections has been dissected for analysing its antigenic myriad. A 65 kDa protein of this mycobacterium has been isolated and characterized for its protective and cell mediated immune responses. The protein was isolated in pure form using an isotachophoresis (SDS-PAGE filtration) technique and identified with low molecular weight markers along with mAb using the immunoblot technique. Mab IIH9 has identified a 65 kDa protein in M. habana. This protein has been found to be immunoprotective in mice against M. tuberculosis H37Rv infection. It generates high levels of DTH responses in mice against M. tuberculosis and M. leprae antigens and inhibits migration of sensitized cells under the antigenic influence of homologous and heterologous origin. Possibilities of developing this protein as a subunit vaccine are discussed in this report.

Animals↗

PubMed1995

Immunoreactive antigens of a candidate leprosy vaccine: Mycobacterium habana.

Mycobacterium habana (M. simiae serovar-1) is a candidate vaccine for mycobacterial infections on the basis of the protection shown by this strain. We prepared 3 fractions of M. habana, i.e. the cell wall (CW), the cell membrane (CM) and the cytosol (CS). Protein antigens of these fractions were resolved by SDS-PAGE and subsequently probed with the sera of leprosy and tuberculosis patients and also antiBCG antibodies. We saw 3 major protein bands at congruent to 33 kD in the CW, congruent to 38 kD in the CM and congruent to 22 kD in the cytosol (CS) after coomassie blue staining of the gels. Pool leprosy patients' serum had identified proteins of congruent to 26 kD in CW, congruent to 35 and congruent to 18 kD in CM and congruent to 24 kD in the CS which have not been seen by the TB patient's serum pool. Pool serum of tuberculosis patients has identified 1 protein at congruent to 10 kD in the CW and a broad band between 20 and 24 kD and 1 at congruent to 4 kD in the CM which have not been visualized in the pool leprosy patient's serum lane. The proteins of M. habana which are recognized only by leprosy antisera or only by tuberculosis antisera could be exploited for developing diagnostic agents against these infections.

Antigens, Bacterial↗

PubMed1994

Tuftsin-bearing liposomes as rifampin vehicles in treatment of tuberculosis in mice.

The antitubercular activity of rifampin was considerably increased when it was encapsulated in egg phosphatidylcholine liposomes. A further increase in the activity was observed when the macrophage activator tetrapeptide tuftsin was grafted on the surface of the drug-loaded liposomes. Intermittent treatments (twice weekly) with these preparations were significantly more effective than the continuous treatments. Rifampin delivered twice weekly for 2 weeks in tuftsin-bearing liposomes was at least 2,000 times more effective than the free drug in lowering the load of lung bacilli in infected animals. However, pretreatment with drug-free tuftsin-bearing liposomes did not render the pretreated animals resistant to the Mycobacterium tuberculosis infections, neither did it appreciably increase the chemotherapeutic efficacy of the liposomized rifampin. These results clearly demonstrate that liposome targeting to macrophages could considerably increase the antitubercular activity of liposomized drugs such as rifampin. Also, it shows that immunoprophylactic treatment with macrophage activators such as tuftsin does not afford any advantage in treatment of tuberculosis infections, presumably because of inactivation of the primed macrophages by the mycobacterial sulfatides.

Amino Acid Sequence↗

PubMed1994

Changes in the virulence of Mycobacterium bovis (BCG Phipps) in carbon tetrachloride treated mice.

Mild grade of liver damage was produced in mice by repeated subcutaneous injection of carbon tetrachloride. These mice along with saline treated mice were challenged with an avirulent vaccine strain of BCG (Phipps), intravenously. The CCl4 treated, BCG challenged mice developed disease and died much earlier than the controls, indicating an increased susceptibility to the avirulent strain in mice with mild hepatitis.

Animals↗

PubMed1994

Evaluation of diversified antigens for detection of Mycobacterium leprae antibodies from leprosy patients and contacts.

A comparative evaluation of diversified antigens in ELISA has been made for detection of M. leprae antibodies in the sera of leprosy patients and their contacts. Out of the four antigens, namely M. leprae sonicate (ML), phenolic glycolipid I (PGL-1), M. habana sonicate (MH) and its arabinomannan (AM), the cross reactive antigens (MH,AM) have comparatively detected more number of leprosy cases. Homologous antigens (ML, PGL-1) have lower detection level. Use of MH and AM for detection of mycobacterial antibodies have been discussed and advocated for epidemiological studies of leprosy/tuberculosis.

Adolescent↗