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Biomedical subjects

I Kaur

Publications and source records attributed to I Kaur.

At least 19 recordsLinked to original sources

Biodegradation of pentachlorophenol (PCP) by white rot fungal strains screened from local sources and its estimation by high-performance liquid chromatography.

White rot fungal strains screened from local sources (wood trunks and from effluents of pulp and paper industry) were tested for their ability to biodegrade polymeric compounds, viz. polymeric dyes (crystal violet and brilliant green) and chlorinated phenol (pentachlorophenol). Two of the most promising strains showing maximum degradation of polymeric dyes were selected to study the biodegradation potential and pattern of biodegradation of pentachlorophenol (PCP), a commonly used leather preservative and a potential carcinogen. PCP was quantitatively estimated and analysed by high-performance liquid chromatography (HPLC). Conditions were optimized for the measurement of PCP on HPLC, which were: mobile phase, 60% acetonitrile and 40% water; flow rate, 1 mL/ min; column, mu Bondapack C18 RP and UV detector at 238 nm. One of the white rot fungal strains isolated from wood trunk showed a maximum 68% biodegradation of PCP in liquid-buffered medium in 16 days. The biodegradation pattern of PCP followed a pseudo-first-order kinetics. Studies on enhancement of biodegradation of polymeric dyes and PCP showed that the kinetics of biodegradation is greatly improved by the presence of manganese ions, H2O2 and glucose in the medium. This strongly suggests the involvement of peroxidase enzyme machinery of white rot fungus in the biodegradation process of PCP.

Biodegradation, Environmental

Leukocyte subsets and neutrophil function after short-term spaceflight.

Changes in leukocyte subpopulations and function after spaceflight have been observed but the mechanisms underlying these changes are not well defined. This study investigated the effects of short-term spaceflight (8-15 days) on circulating leukocyte subsets, stress hormones, immunoglobulin levels, and neutrophil function. At landing, a 1.5-fold increase in neutrophils was observed compared with preflight values; lymphocytes were slightly decreased, whereas the results were variable for monocytes. No significant changes were observed in plasma levels of immunoglobulins, cortisol, or adrenocorticotropic hormone. In contrast, urinary epinephrine, norepinephrine, and cortisol were significantly elevated at landing. Band neutrophils were observed in 9 of 16 astronauts. Neutrophil chemotactic assays showed a 10-fold decrease in the optimal dose response after landing. Neutrophil adhesion to endothelial cells was increased both before and after spaceflight. At landing, the expression of MAC-1 was significantly decreased while L-selectin was significantly increased. These functional alterations may be of clinical significance on long-duration space missions.

Adrenocorticotropic Hormone

Pulmonary function changes in patients with psoriasis on methotrexate therapy.

Methotrexate is known to induce pulmonary fibrosis. The present study was undertaken to assess pulmonary toxicity, if any, in psoriasis patients on methotrexate therapy and correlate the dose and duration of the treatment with any changes in pulmonary function. Ten patients who had taken methotrexate for one year and ten patients receiving methotrexate were included in the present study. Detailed lung function studies including arterial blood gas analysis were carried out. In both groups, the only pulmonary function abnormalities detected were FEF200-1200, FEF25-75%, residual volume (RV), and RV/TLC%, which showed a decline after six months of treatment. However, this was not significant. No changes were detected in the arterial blood gas values following methotrexate therapy. Therefore, the present study did not find any significant deterioration of lung functions in psoriasis patients on methotrexate therapy.

Adult

Macular lesions in leprosy: a clinical, bacteriological and histopathological study.

Among 150 untreated patients of leprosy, 19 had only macular lesions; three were of the indeterminate type, and eight each were of the tuberculoid and the borderline types, according to the Indian Association of Leprologists (IAL, 1981) classification. The clinical, bacteriological, and histopathological parameters of these 19 patients were studied both before and after six months of WHO Multi Drug Therapy (MDT/1982). A single macule was present in seven (36.84%) patients. In twelve (63.16%), two or more were seen. In eighteen (94.74%), one or more peripheral nerves were enlarged. The size of the macules varied from 5 to 15 cm, and there were no changes seen even after treatment. In most (94.74%) of the patients, the macules were hypopigmented. The surfaces were rough and dry in seven (36.84%) but smooth in the other twelve (63.16%). The margins were well defined in the seven (36.84%) patients with single macules but ill defined in the other twelve (63.16%). After six months of antileprosy treatment, the single macules showed some resolution. Slit skin smear examination was negative in all cases before and after treatment. Clinico-histopathological correlations were seen in only six (31.58%) patients; the clinical diagnoses were indeterminate and tuberculoid leprosy in three (15.79%) patients each. In the indeterminate group, the clinico-histopathological correlation was 100%; it was 37.50% in the tuberculoid group. There were no correlations between the clinical and histopathological parameters in thirteen (68.42%) cases. After six months of treatment, the histopathology became nonspecific in all patients. The lepromin test was positive in six (31.58%) patients; four were of the tuberculoid group and one each from the indeterminate and borderline leprosy groups. Hence, although macular lesions can be seen throughout the leprosy spectrum, it is difficult to correlate their clinical, bacteriological and histopathological parameters.

Adolescent

Vitiligo: clinical findings in 1436 patients.

We retrospectively analyzed the clinical and epidemiological profiles of patients with vitiligo attending the pigmentary dermatoses clinic. One thousand four hundred and thirty-six patients were seen between 1989 and 1993. Males constituted 54.5% of the group and females 45.5%. Mean age of the patients was 25 years, and average disease duration at the time of hospital visit was 3.7 years. Vitiligo vulgaris was the commonest form of the disease in 1002 (69.8%) patients followed by focal vitiligo in 214 (14.9%) and segmental vitiligo in 72 (5.0%). The sites of onset were the face, trunk, and legs in descending order of frequency. Less than 20% body area involvement was seen in 1356 (94.4%) of the patients. Leukotrichia was present in 165 (11.5%), and Koebner's phenomenon was observed in 72 (5.0%). Twenty nine (2.0%) patients had associated halo nevi. Of the various diseases associated with vitiligo, atopic/nummular eczema was seen in 20 (1.4%) patients, bronchial asthma in 10 (0.7%), diabetes mellitus in 8 (0.6%), thyroid disease in 7 (0.5%), and alopecia in 6 (0.4%). A family history of vitiligo was present in 165 (11.5%) patients.

Adolescent

Macular amyloidosis: etiological factors.

Macular amyloidosis is the commonest form of primary localized cutaneous amyloidosis; its etiology remains unclear. Various incriminating factors include genetics, sunlight, and friction. Seventy-five patients with a clinical diagnosis of macular amyloidosis (confirmed by at least two observers) were enrolled in the study. A detailed history was elicited in relation to the etiological factors and followed by cutaneous examination. Skin biopsy was performed in 44 patients. Amyloid deposits were demonstrated in 21 (48%) of the biopsies. The female to male ratio was over 3:1. Patients with skin type V had a more delayed onset than those with skin types III and IV. Two patients gave histories of regularly subjecting their skin to friction. There was no correlation between the sites affected and the sites subjected to friction, hair style of the patient, or the use of cosmetics. Family history was present in 7 (9.3%) patients. A majority, 44 (58.7%) of the patients, had involvement of both sun-exposed and sun-protected sites. To conclude, there was no direct correlation between macular amyloidosis and atopy, sunlight, or friction to the skin in our patients. Multiple factors may play a collective role in the genesis of macular amyloidosis to variable degrees. These include racial, familial, and environmental factors, atopy, sunlight, friction, and female gender.

Adolescent

Immunological defect in leprosy patients: altered T-lymphocyte signals.

The early events of activation were studied in paucibacillary (TT/BT) and multibacillary (BL/LL) leprosy patients by stimulation of their lymphocytes with mitogenic agents (calcium ionophore A23187/PMA) and Micobacterium leprae antigen (PGL-1). Maximum proliferation in response to PMA/A23187 and PGL-1 was observed in the BT/TT patients and the control group, respectively. Inositol triphosphate (IP3) and calcium were constitutively elevated in BT/TT and LL/BL patients. PMA/A23187 caused an increase in both IP3 and [Ca2+]i in BT/TT patients and controls. PGL-1 marginally increased IP3 levels in BT/TT patients. In the LL/BL patients, although PMA/A23187 increased IP3 levels, but no change was seen in [Ca2+]i, PGL-1 had no effect. Protein kinase C levels were seen to be associated with particulate fractions in BT/TT patients and were found to increase further in response to PMA/A23187. PGL-1 did not increase translocation of protein kinase C in controls or LL/BL patients. A preactivated and sensitised state of T-lymphocytes was observed in BT/TT patients, responsive to antigen and mitogens, whereas the cells of LL/BL patients were unresponsive to PGL-1. The altered signal transduction events characterised in the MB patients thus correlate well with the anergic state of their cells.

Calcium

Impaction bone-grafting increases the holding power of cancellous screws in the femoral head. A pull-out study in human cadaver hips.

We studied the effect of impaction of fresh cancellous bone or demineralized bone matrix (DBM) around cancellous screws in 25 cadaver femoral heads. The bone mineral content (BMC) of femoral heads was measured to determine if greater relative increase in holding power will be achieved by impaction-grafting, as the BMC of the specimen decreases. A 60% (p < 0.001) relative increase in the pull-out force was achieved by impaction-grafting with DBM, compared to non-grafted controls. The augmenting effect of fresh cancellous bone graft and DBM did not differ significantly. The relative improvement in holding power was not inversely correlated to femoral head BMC, but was inversely related to the pull-out resistance of non-grafted control screws. These findings suggest that impaction-grafting provides significantly better hold of cancellous screws in femoral heads.

Bone Density

Presence of M. leprae in tissues in slit skin smear negative multibacillary (MB) patients after WHO-MBR.

This study looked for M. leprae in the lymph node, nerve and skin of multibacillary (MB) leprosy patients who become slit skin smear negative after the completion of WHO-MBR. Twenty-five WHO-MBR-treated multibacillary leprosy patients were studied; borderline lepromatous (BL) leprosy (n = 11) and lepromatous (LL) leprosy (n = 14)). Fifteen patients had reaction (erythema nodosum leprosum 11, upgrading reaction 4) either at presentation or during therapy. All patients attained slit skin smear negativity after WHO-MBR (range 24-39 months. Sixteen (64%) patients with multibacillary leprosy showed fragmented bacilli in skin and nerve biopsy or lymph node aspirates after WHO-MBR. Lymph node aspirates alone revealed M. leprae in seven patients, followed by nerve in two and skin in one patient. Four cases showed M. leprae at all sites followed by nerve and skin or lymph node in one case each. A pretreatment bacteriological index (BI) of 4+ or more was significantly associated with the presence of M. leprae at the end of treatment. Also, significantly more lymph node aspirates contained M. leprae in comparison with nerve or skin biopsies. All seven cases in whom treatment was extended beyond 24 months showed M. leprae in tissues even after attaining slit smear negativity. In conclusion, M. leprae persist in tissues after 2 years of WHO-MBR and patients with an initial BI of 4+ or more need to be closely followed up after stopping MDT.

Adolescent

Alterations in early biochemical events following T cell activation in leprosy patients.

The early events of activation and cytokine profiles (IL-2, 4, and 6) were studied in lymphocytes of paucibacillary (TT/BT) and multibacillary (BL/LL) leprosy patients after stimulation with PMA/A23187 and Mycobacterium leprae antigen (PGL-1). Lymphocytes from BT/TT patients showed proliferation in response to both PMA/A23187 and PGL-1 compared to BL/LL. The levels of early activation signaling molecules such as IP3, calcium, and protein kinase C (PKC) in the particulate fraction were found to be elevated in BT/TT and BL/LL patients and showed a further significant increase after stimulation with PMA/A23187 in BT/TT patients. PGL-1 marginally increased the IP3 levels in BT/TT patients, whereas in BL/LL patients, it had no effect. The levels of IL-2 were enhanced in lymphocytes of BT/TT leprosy patients and were further augmented by PPD and PGL-1, while the levels of IL-4 and IL-6 were increased in LL/BL lymphocytes and further augmented by PGL-1. Thus PGL-1 seems to be a major culprit in inducing the TH2-type cytokine response observed in lepromatous leprosy patients.

Antigens, Bacterial

Hormonal milieu in the maintenance of melasma in fertile women.

Melasma is a specific type of facial hyperpigmentation seen in women taking oral contraceptives, in non-pregnant women who have not used oral contraceptives, and in some pregnant women during the progression of gestation, but rarely in men. Circulating LH, FSH, PRL, and E2-17 beta on day 5, 7, 9, and 11 of the menstrual cycle and progesterone (P) on day 17, 19, and 21 were measured in thirty-six ovulating women with melasma (study group) age 25-35 years and twelve healthy controls (control group). Twenty-seven subjects in the study group had normal pregnancies; 9 others were married or single and had no history of contraceptive pill use. Higher levels of FSH on day 7 (p < 0.05); E2-17 beta on 5, 7, 9 (p < 0.05) and LH on day 9 (p < 0.002) were observed in the study group than in the control group. There were no significant differences between the LH/FSH ratio in the two groups. Serum PRL was lower on day 9 in the study group (p < 0.05) than in the control group. Serum P was similar in the patients and the controls. These findings indicate a possible role of high E2-17 beta in the maintenance of melasma.

Adult

Computed tomographic study of paranasal sinuses in lepromatous leprosy.

Twenty patients (18 males, 2 females) with lepromatous leprosy and 10 age- and sex-matched controls were subjected to computed tomographic (CT) scans of the paranasal sinuses (PNS). The mean bacterial (BI) and morphological indexes were 3.4+ and 1%, respectively. Nasal symptoms were present in nine (45%) patients; 15 (75%) out of 20 patients showed significant abnormalities on CT scans of the PNS compared to none of the 10 controls. The maxillary and ethmoid sinuses were affected in 11 (55%) patients each, followed by the sphenoid sinus in four (20%) patients. Frontal sinus involvement was least frequent, only one (5%) patient showed CT changes. Mucosal thickening was the most common finding followed by soft-tissue densities and, rarely, a fluid level was seen in the PNS. Involvement of the PNS correlated with a high BI of 4+ or more (75% vs 37.5%). Paranasal sinus involvement is an integral part of lepromatous leprosy since histological involvement was present even when the CT scan was apparently normal.

Female

Lipoprotein from Yersinia enterocolitica contains epitopes that cross-react with the human thyrotropin receptor.

Yersinia enterocolitica has recently been shown to produce a low molecular mass envelope protein that contains an epitope(s) that is cross-reactive with the extracellular domain of the human thyrotropin receptor (ETSHR). In this study, we have generated mAb to this cross-reactive protein and have obtained amino acid sequences for peptide fragments obtained from Lys-c digestion of the protein. The amino acid sequences of these peptides were identical to sequences present in bacterial lipoprotein (LP). All bacteria of the Enterobacteriaceae family produce LP as a major outer membrane protein. However, the ETSHR cross-reactive epitope(s) was shown to be unique to LP produced by Yersinia species. This was shown by Western blot analysis using a mAb specific for LP and with affinity-purified Ab specific for either LP or ETSHR and obtained from mouse antiserum generated to Y. enterocolitica. LPs from different Gram-negative bacteria were shown to be mitogenic for C3H/HeJ spleen cells and induced production and secretion of significant levels of Ig. Production of Ab that recognized the ETSHR was only induced in spleen cells stimulated with the LP obtained from Yersinia. In contrast, LP was not mitogenic for either human PBMC or human B cells. However, LP did induce IL6 and IL8 production in human monocytes at levels equivalent to that seen after LPS activation. These results identify, for the first time, the Yersinia envelope protein that is cross-reactive with the ETSHR and show that it can activate human monocytes. These findings are potentially important for advancing our understanding of the role molecular mimicry plays in the induction of autoimmunity to the thyrotropin receptor.

Amino Acid Sequence

Coal tar therapy in palmoplantar psoriasis: old wine in an old bottle?

BACKGROUND: Palmoplantar psoriasis (PPP) is a disabling condition which is usually resistant to most of the available therapeutic modalities. Coal tar is an accepted therapy for psoriasis which has not been well studied for PPP. METHODS: Thirty patients with a plaque type of PPP were allocated into two groups: Group A (19 patients) were treated with 6% crude coal tar (CCT) ointment and Group B (11 patients) were treated with white petrolatum and salicylic acid. In both groups, ointment was applied and left on overnight. Wearing of gloves and socks during the night and application of emollients in the day was routinely advised. The lesions were assessed for erythema, scaling, and induration (ESI) every 2 weeks for a total of 8 weeks. Patients with greater than 50% improvement were considered to have good improvement. Side-effects, if any, were also monitored. RESULTS: In Group A, 76.5% of patients (13/17) showed good improvement, whereas only 45.5% of patients (5/11) in Group B showed the same magnitude of improvement (P < 0.05). No side-effects were reported by any patient in either of the groups. CONCLUSIONS: Crude coal tar is a safe, effective, and inexpensive modality for the treatment of PPP. We recommend coal tar under occlusion, along with the liberal use of emollients, as the first line of therapy for all cases of PPP.

Administration, Topical