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Biomedical subjects

Neena Khanna

Publications and source records attributed to Neena Khanna.

9 recordsLinked to original sources
PubMed2006

Alterations in T cell signal transduction by M. leprae antigens is associated with downregulation of second messengers PKC, calcium, calcineurin, MAPK and various transcription factors in leprosy patients.

Mycobacterium leprae, the causative agent of leprosy, challenges host defense mechanism by impairing the signal transduction of T cells which leads to downregulation of T cell proliferation, mainly as a consequence of interference with IL-2 production. In this study we sought to identify how soluble forms of M. leprae antigen(s) or particulate (liposome) delivery of the same antigens with two immunomodulators Murabutide and T cell peptide of Trat protein influence the transcription of IL-2 gene in anergic T cells of lepromatous patients. It was demonstrated that MLCwA/ManLAM stimulated cells of BL/LL patients showed defects in both jun-NH2-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) activities there by resulting in decreased AP-1 activity. Additionally these cells showed reduced calcium levels, PKC activity and calcineurin (CN) activity. This led to impaired nuclear translocation of NFkappaB and NFAT in these patients. In contrast, when same M. leprae antigen(s) were incorporated with the two immunomodulators in liposomal form, increased transcription of IL-2 gene was observed especially in BL/LL patients which appears to be due to, at least in part, to increased expression of AP-1 Fos and Jun family members, NFkappaB and NFAT1 proteins. The increased expression of these transcription factors correlated with increased ERK/JNK, PKC and CN activities in these patients. Since activation of ERK/JNK/PKC kinases and CN phosphatase are required for stimulation of IL-2 transcription, these data provide a molecular explanation for the block in IL-2 production by M. leprae antigens. Thus the above study revealed suppression of all the three distinct biochemical pathways, viz. Ca-CN-NFAT pathway, PKC-NF-kappaB pathway, and MAPK-AP-1 pathway by M. leprae antigen(s) in anergized T cells of lepromatous patients which were activated by liposomal delivery of M. leprae antigens containing the two immunomodulators leading to optimal induction of IL-2 gene expression, which was required for the activation, and proliferation of T cells in lepromatous patients.

Antigens, Bacterial↗
PubMed2006

Evaluation of the diagnostic efficacy of PCR for Ureaplasma urealyticum infection in Indian adults with symptoms of genital discharge.

Ureaplasma urealyticum genital infection may lead to severe clinical implications if left undiagnosed and untreated. The present study was conducted to evaluate the diagnostic efficiency of a polymerase chain reaction (PCR) assay and to determine the prevalence of U. urealyticum in Indian adults with symptoms of genital discharge. Cervical swabs, vaginal swabs and male urethral swabs from 100 patients attending an sexually transmitted disease clinic at a tertiary care hospital in Delhi were screened prospectively for infection with U. urealyticum. The prevalence of U. urealyticum was found to be 32% by culture and 45% by PCR. U. urealyticum was recovered from 8 (47%) and 37 (45%) symptomatic men and women, respectively. The agreement between PCR and culture was 93.75%. PCR improved the test sensitivity by 13% compared to culture. The results confirm the need to use a sensitive and reliable molecular method to prevent the underdiagnosis of ureaplasma infection and to facilitate better clinical management of this infection in India.

Colony Count, Microbial↗
PubMed2005

Lesional T-cell subset in post-kala-azar dermal leishmaniasis.

BACKGROUND: The pathogenesis of post-kala-azar dermal leishmaniasis (PKDL) is ill understood. This study was carried out to find the percentage of T-helper and T-suppressor cells in lesional tissue and their probable role in the pathogenesis of PKDL. METHODS: An immunoperoxidase monoclonal antibody technique was used to characterize and quantify the subsets of T lymphocytes in the infiltrate in 25 patients with PKDL. RESULTS: The ratio of T-helper to T-suppressor cells was 0.87 in hypopigmented macules and 0.85 in nodule and/or plaque lesions of PKDL. CONCLUSIONS: In this study, there was a definite preponderance of T-suppressor cells over T-helper cells in both types of skin lesions of PKDL. Further studies should be undertaken on larger numbers of patients to compare T-cell subsets both in skin lesions and the circulation, in order to determine the pathogenesis of PKDL.

Adolescent↗
PubMed2003

Reversal of T cell anergy in leprosy patients: in vitro presentation with Mycobacterium leprae antigens using murabutide and Trat peptide in liposomal delivery.

Mycobacterium leprae, the causative agent of leprosy resides and multiplies within the host monocytes and macrophages, thereby evading host immune system. Cell-mediated immune response (CMI) plays a vital role as evidenced from the high CMI in BT/TT (borderline and tuberculoid) patients and conversely low in BL/LL (borderline and lepromatous) patients. In the present study, an attempt was made to immunomodulate the anergized T cells of lepromatous leprosy patients by presenting the mycobacterial antigen in combination with T cell adjuvant, murabutide (active analog of muramyl' dipeptide, MDP-BE) and a Trat peptide (T cell epitope of Integral membrane protein (Trat) from Escherichia coli) in particulate form (liposomes) or soluble form (media). PBMNC of normal, BT/TT and BL/LL were stimulated in vitro with five mycobacterial antigens (Ag) in the following formulations, Ag, Ag+murabutide, Ag+murabutide+Trat peptide either in liposomes or in medium. All the five antigen(s) when delivered in liposomes containing murabutide and Trat peptide showed a very high lymphoproliferative response (p<0.001) in all the three groups. IFN-gamma and IL-2 were significantly (p<0.001) high in these culture supernatants compared to IL-10 and IL-4 confirming a shift from CD4+Th2 to Th1 response in leprosy patients with particulate mode of antigen presentation. Interestingly, PBMNC derived from lepromatous patients also showed consistent T cell proliferation with all the formulations. Further, the mechanism of liposomal processing of antigens was studied using different inhibitors that interfere at different stages of antigen presentation. Results indicate that this study may pave way for an immunotherapeutic approach for reverting the anergic T cells of lepromatous patients to proliferating T cells with the release of Th1 cytokines thereby restoring the CMI response in these patients.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed2003

Lupoid sycosis of pubic area.

Lupoid sycosis is a rare cicatricial form of chronic folliculitis commonly seen in men after puberty. It usually involves the beard area and is refractory to treatment. We here report two cases of lupoid sycosis; one had additional involvement of the pubic area. Both patients showed complete clearance with minocycline.

Adult↗
PubMed2002

Rejuvenating facial massage--a bane or boon?

BACKGROUND: Facial massage is an extremely popular form of beauty treatment and is thought to rejuvenate the skin. We decided to study the benefits and untoward effects of this form of facial beauty treatment. METHODS: One hundred and forty-two women (aged 17-63 years), who had received facial beauty treatment in three well-established beauty parlours in New Delhi, were entered into the study and observed for a period of 12 weeks after the facial beauty treatment. Twenty-seven of the subjects had a repeat facial beauty treatment 4-6 weeks after entry into the study, giving a total of 169 massage episodes observed. Immediate and delayed effects of the beauty treatment were examined. RESULTS: Facial beauty treatment generally consists of three steps: vigorous massaging of the face with creams, steaming (using a hot towel or a steaming gadget), and application of a face mask containing adsorbents and astringents. In our study, the creams used for massage included "off the shelf" creams manufactured by standard cosmetic companies in 95 (56.3%) subjects, herbal creams in 61 (36.1%), and creams containing exotic ingredients, such as gold salts, in 13 (7.7%). Sixty-one (36.1%) patients developed erythema and puffiness within 15 min to 2 h after the beauty treatment. This lasted for 2-6 h. Forty-one (24.3%) women underwent the procedure of comedone extraction after steaming. In 12 (7.1%) of these women, persistent erythema was noticed at the site of comedone extraction. Eight (4.7%) women developed mild dermatitis on the face, 2-7 days after the facial beauty treatment. Patch testing with constituents used in the facial beauty treatment was positive in four patients (herbal cream, 1; witch hazel, 1; orange face pack, 1; and gold cream, 1). In 47 (33.1%) subjects, an acneiform eruption was observed 3-10 weeks after the facial beauty treatment (mean, 6.1 +/- 3 weeks). Thirteen (27.7%) of these subjects had taken the facial beauty treatment for the first time, whereas 34 (72.3%) developed an acneiform eruption after every facial massage. The predominant lesions were deep-seated nodules, although a few comedones, especially closed ones, were present in some patients. Lesions were always present on the cheeks, an area of focus during the facial massage, and healed with hyperpigmentation. The benefits of facial beauty treatment, as mentioned by the subjects, included a feeling of freshness and rejuvenation in 84 (59.1%), keeping the skin supple in 76 (53.5%), feeling of warmth and tightening of the skin in 71 (50%), and delaying the onset of wrinkles in 21 (14.8%). CONCLUSIONS: Although there are several subjective benefits with facial beauty treatment, there may be immediate side-effects, such as erythema and edema, as well as delayed problems, such as dermatitis and acneiform eruption, in about one-third of patients.

Adult↗