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Biomedical subjects

Mamta Singh

Publications and source records attributed to Mamta Singh.

16 recordsLinked to original sources
PubMed2006

Application of cytology and molecular biology in diagnosing premalignant or malignant oral lesions.

Early detection of a premalignant or cancerous oral lesion promises to improve the survival and the morbidity of patients suffering from these conditions. Cytological study of oral cells is a non-aggressive technique that is well accepted by the patient, and is therefore an attractive option for the early diagnosis of oral cancer, including epithelial atypia and squamous cell carcinoma. However its usage has been limited so far due to poor sensitivity and specificity in diagnosing oral malignancies. Lately it has re-emerged due to improved methods and it's application in oral precancer and cancer as a diagnostic and predictive method as well as for monitoring patients. Newer diagnostic techniques such as "brush biopsy" and molecular studies have been developed. Recent advances in cytological techniques and novel aspects of applications of scraped or exfoliative cytology for detecting these lesions and predicting their progression or recurrence are reviewed here.

Cytodiagnosis↗
PubMed2006

Iron bioavailability: UK Food Standards Agency workshop report.

The UK Food Standards Agency convened a group of expert scientists to review current research investigating factors affecting iron status and the bioavailability of dietary iron. Results presented at the workshop show menstrual blood loss to be the major determinant of body iron stores in premenopausal women. In the presence of abundant and varied food supplies, the health consequences of lower iron bioavailability are unclear and require further investigation.

Biological Availability↗
PubMed2006

Female infertility: role of vaginal hormonal cytology, endometrial biopsy and endocrinological evaluation.

Female infertility can be categorised into those who fail to ovulate (anovulatory infertility) because of some defect at hypothalamic-pituitary-ovarian axis and those who are ovulatory (ovulatory infertility), but are infertile because of some lesion present in genital tract. The role of vaginal hormonal cytology, endometrial biopsy and endocrinological evaluation in the detection of ovulation and various ovulatory dysfunction was studied in 42 infertile female patients. On the basis of cytological findings, of the 42 patients, 14 were found to be ovulatory, 26 anovulatory (which include 5 cases of atrophic changes) and 2 inconsistent due to inflammatory changes. Endometrial biopsy showed evidence of ovulation in 15, anovulation in 27 cases. Hormonal evaluation indicated some sort of endocrinological disorders in 15 patients, which may underlie anovulatory infertility in these patients, while results were within normal range in the rest 27 patients. Results of vaginal cytology and endometrial biopsy showed correlation in respect to ovulation in 93.33% of the cases.

Anovulation↗
PubMed2006

HIV seroprevalence in patients with tuberculosis in Allahabad, North India.

250 patients with evidence of pulmonary tuberculosis and 50 nontubercular patients as a control group were subjected to Tuberculin test, Chest X-Ray, sputum microscopy, screening for HIV by ELISA and confirmation by Western blot if ELISA test was found positive. In the study group, 11 tested positive for HIV-1 and 239 tested seronegative, however, in the control group all patients were HIV seronegative. HIV infection was most prevalent in young males in the 21-40 year age group, with a history of tuberculosis, either residing, or working in an urban area away from their family. All our cases were of the HIV-1 serotype.

Adolescent↗
PubMed2006

Risk of iron overload in carriers of genetic mutations associated with hereditary haemochromatosis: UK Food Standards Agency workshop.

The UK Food Standards Agency convened a group of expert scientists to review current research investigating diet and carriers of genetic mutations associated with hereditary haemochromatosis. The workshop concluded that individuals who are heterozygous for the C282Y mutation of the HFE gene do not appear to respond abnormally to dietary Fe and therefore do not need to change their diet to prevent accumulation of body Fe.

Atherosclerosis↗
PubMed2005

Susceptibility of mice genetically deficient in the surfactant protein (SP)-A or SP-D gene to pulmonary hypersensitivity induced by antigens and allergens of Aspergillus fumigatus.

Lung surfactant protein A (SP-A) and D (SP-D) are innate immune molecules which are known to interact with allergens and immune cells and modulate cytokine and chemokine profiles during host hypersensitivity response. We have previously shown therapeutic effects of SP-A and SP-D using a murine model of lung hypersensitivity to Aspergillus fumigatus (Afu) allergens. In this study, we have examined the susceptibility of SP-A (AKO) or SP-D gene-deficient (DKO) mice to the Afu allergen challenge, as compared with the wild-type mice. Both AKO and DKO mice exhibited intrinsic hypereosinophilia and several-fold increase in levels of IL-5 and IL-13, and lowering of IFN-gamma to IL-4 ratio in the lungs, suggesting a Th2 bias of immune response. This Th2 bias was reversible by treating AKO or DKO mice with SP-A or SP-D, respectively. The AKO and DKO mice showed distinct immune responses to Afu sensitization. DKO mice were found more susceptible than wild-type mice to pulmonary hypersensitivity induced by Afu allergens. AKO mice were found to be nearly resistant to Afu sensitization. Intranasal treatment with SP-D or rhSP-D (a recombinant fragment of human SP-D containing trimeric C-type lectin domains) was effective in rescuing the Afu-sensitized DKO mice, while SP-A-treated Afu-sensitized AKO mice showed several-fold elevated levels of IL-13 and IL-5, resulting in increased pulmonary eosinophilia and damaged lung tissue. These data reaffirm an important role for SP-A and SP-D in offering resistance to pulmonary allergenic challenge.

Allergens↗
PubMed2005

Extramedullary blast crisis in chronic myeloid leukemia--a case report.

Presence of focal poliferation of myeloblasts at an extramedullary site even when peripheral blood/bone marrow blast count is less than 20% in a case of chronic myeloid leukaemia leads to a diagnosis of blast crisis. A case of focal extramedullary blast crisis with chronic myeloid leukaemia is reported here.

Adult↗
PubMed2004

Serial scrape smear cytology of radiation response in normal and malignant cells of oral cavity.

Serial scrape smears were taken from 111 patients receiving radiotherapy for squamous cell carcinoma of the oral cavity. The surface of the tumour and the normal mucosa on the opposite side was scraped before and after delivery of various fractions of radiotherapy and were evaluated by light microscopy. The number of cells exhibiting changes like multinucleation, micronucleation, nuclear budding, binucleation and cytoplasmic granulation were counted. The results were expressed as abnormality per 1000 cells. Each parameter showed a statistically significant increase with radiation dose in both normal and malignant oral cells. In the normal mucosal cells the mean values after 6Gy and 24Gy respectively were 0.83 and 2.91 (p<0.001) for cells with multinucleation, 1.83 and 4.42 (p<0.001) for micronucleation, 2.58 and 5.15 (p<0.001) for nuclear budding, 5.92 and 12.58 (p<0.001) for binucleation, and 3.67 and 7.17 (p<0.001) for cytoplasmic granulation. On the other hand, in malignant cells, the mean values before and after treatment with 24 Gy respectively, were 3.14 and 7.08 (p<0.001) for cells with multinucleation, 1.05 and 5.97 (p<0.001) for micronucleation, 2.54 and 8.82 (p<0.001) for nuclear budding 7.11 and 27.93 (p<0.001) for binucleation and 5.32 and 12.02 (p<0.001) for cytoplasmic granulation. The study showed that there is a dose-related increase in multinucleation, micronucleation, nuclear budding, binucleation and cytoplasmic granulation after various fractions of radiotherapy in both normal and malignant oral cells, however these changes are more marked in the malignant cells.

Adult↗
PubMed2004

Radiation-related cytological changes in oral malignant cells.

Carcinoma of the oral cavity constitutes approximately 40% of overall malignant tumours in India, with an incidence of about 56,000 cases per year. Radiation responses in oral cancer cells by cytology have not been extensively studied. 102 patients with squamous cell carcinoma of the oral cavity treated by fractionated radiotherapy were studied. Serial scrape smears were taken from each tumour before and after irradiation. The abnormal nuclear counts per 1000 malignant cells were 1.6 and 14.1(p<0.001) for micronucleation, 0.9 and 5.5 (p<0.001) for nuclear budding, 7.6 and 28.1(p<0.001) for binucleation and 2.4 and 11.7(p<0.001) for multinucleation respectively. The study showed a significant rise in radiation induced cytological responses. In addition, radiation changes observed included abnormal and incomplete divisions of a nucleus, fibroblast like appearance cells, and enlargement of nuclear size as well as cytoplasmic granulation. These changes may have an important role to play in understanding the mechanism of cell killing after radiotherapy.

Adult↗
PubMed2003

Protective effects of a recombinant fragment of human surfactant protein D in a murine model of pulmonary hypersensitivity induced by dust mite allergens.

Lung surfactant protein D (SP-D) is a carbohydrate pattern recognition immune molecule. It can interact with a range of pathogens, stimulate immune cells and manipulate cytokine profiles during host's immune response. SP-D has also been shown to interact, via its carbohydrate recognition domains, with glycoprotein allergens of house dust mite (Dermatophagoides pteronyssinus, Derp), inhibiting specific IgE isolated from mite-sensitive asthmatic patients from binding these allergens, and blocking subsequent histamine release from sensitized basophils. In the present study, we have examined the protection offered by various doses of intranasal administration of a recombinant fragment of human SP-D (rhSP-D) in a murine model of pulmonary hypersensitivity to Derp allergens which showed characteristic high levels of specific IgE antibodies, peripheral blood eosinophilia, pulmonary infiltrates and a Th2 cytokine response. Treatment of Derp mice with rhSP-D led to significant reduction in Derp-specific IgE levels, blood eosinophilia and pulmonary cellular infiltration. The levels of IL-4 and IL-5 were decreased, while those of IL-12 and IFN-gamma were raised in the supernatant of the cultured splenocytes, indicating a Th2 to Th1 polarization. These results suggest that SP-D has a protective role in the modulation of allergic sensitization and in the development of allergic reactions to Derp allergens and highlight potential of the rhSP-D as a therapeutic for pulmonary hypersensitivity.

Administration, Intranasal↗
PubMed2003

Pleomorphic lipoma of the tonsillar fossa--a case report.

Pleomorphic lipoma is a benign adipocytic tumor, commonly located in the shoulder and posterior neck region. The presence of bizarre, hyperchromatic stromal cells along with multinucleated giant cells often poses difficulty in diagnosis, especially when it arises at an unusual site like tonsillar fossa.

Adipocytes↗
PubMed2003

Asymptomatic essential thrombocythemia: a case report.

Essential thrombocythemia (ET) is a clonal disorder of unknown etiology involving multipotent hematopoietic progenitor cell and belongs to the spectrum of chronic myeloproliferative disorders (CMPD). It is rarest of the CMPD with no case reported from India. The case being presented was detected incidentally during routine investigations in an adult female who presented with mild abdominal discomfort.

Adult↗
PubMed2002

Protective roles of pulmonary surfactant proteins, SP-A and SP-D, against lung allergy and infection caused by Aspergillus fumigatus.

Pulmonary surfactant proteins, SP-A and SP-D, are immune molecules which can directly interact with pathogens and allergens, stimulate immune cells and manipulate cytokine and chemokine profiles during host's immune response. Using an opportunistic fungal pathogen Aspergillus fumigatus (Afu), we have attempted to understand participation of SP-A and SP-D in the host immunity. Afu causes a systemic infection via lungs, called invasive aspergillosis (IPA) in immunocompromised subjects. In the immunocompetent subjects, it can cause an allergic disorder, called allergic bronchopulmonary aspergillosis (ABPA). Therapeutic administration of these proteins in a murine model of IPA can rescue mice from death. Treating mice, having ABPA, can suppress IgE levels, eosinophilia, pulmonary cellular infiltration and cause a marked shift from a pathogenic Th2 to a protective Th1 cytokine profile. These results highlight the potential of SP-A, SP-D and their recombinant forms, as novel therapeutics for lung allergy and infection.

Animals↗
PubMed2002

Relationship between oxidative stress and embryotoxicity of hydrosalpingeal fluid.

BACKGROUND: Oxidative stress mechanisms are involved in the pathophysiology of many reproductive disorders. The objective of this study was to characterize oxidative stress parameters in hydrosalpingeal fluid (HSF) and examine their possible role in early embryo development. METHODS AND RESULTS: HSF was aspirated at laparoscopic salpingectomy in 11 infertile women. Reactive oxygen species (ROS), total (non-enzymatic) antioxidant capacity (TAC) and lipid peroxidation (LPO) were assayed. Two-cell mouse embryos were incubated with 25, 50 or 75% HSF and the blastocyst development rate was observed. ROS was detected in five of 11 (45%) HSF samples with a mean of 4.2 x 10(4) c.p.m. LPO was detected in all samples at a mean (+/- SD) value of 5575.4 +/- 6091.9 micromol/l malonaldehyde. The mean blastocyst development rate at 25, 5+/- 0 and 75% HSF and in the control group was 88.9 +/- 9.4, 65.7 +/- 19.1, 45.7 +/- 5.7 and 96.7% respectively (P < 0.0001). The blastocyst development rate was positively correlated to ROS concentrations (P < 0.02) but was not significantly related to LPO. CONCLUSIONS: The blastocyst development rate decreased with increasing concentrations of HSF. For the first time, the presence of ROS, LPO and TAC activity in human HSF was characterized. A possible role of oxidative stress in the embryotoxicity of HSF is suggested.

Animals↗
PubMedDate not supplied

Surfactant proteins SP-A and SP-D in human health and disease.

Surfactant proteins A (SP-A) and D (SP-D) are lung surfactant-associated hydrophilic proteins that have been implicated in surfactant homeostasis and pulmonary innate immunity. They are collagen-containing C-type (calcium-dependent) lectins, called collectins, and are structurally similar to mannose-binding protein of the lectin pathway of the complement system. Being carbohydrate pattern-recognition molecules, they recognize a broad spectrum of pathogens and allergens via the lectin domain, with subsequent activation of immune cells via the collagen region, thus offering protection against infection and allergenic challenge. SP-A and SP-D have been shown to be involved in viral neutralization, clearance of bacteria, fungi, and apoptotic and necrotic cells, down-regulation of allergic reaction, and resolution of inflammation. Studies on single-nucleotide polymorphism, protein levels in broncho-alveolar lavage, and gene knock-out mice have clearly indicated an association between SP-A and SP-D and a range of pulmonary diseases. In addition, recent studies using murine models of allergy and infection have raised the possibility that the recombinant forms of SP-A and SP-D may have therapeutic potential in controlling pulmonary infection, inflammation, and allergies in humans.

Animals↗