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Biomedical subjects

Mahesh Chandra

Publications and source records attributed to Mahesh Chandra.

7 recordsLinked to original sources
PubMed2004

Nitric Oxide as a Unique Bioactive Signaling Messenger in Physiology and Pathophysiology.

Nitric oxide (NO) is an intra- and extracellular messenger that mediates diverse signaling pathways in target cells and is known to play an important role in many physiological processes including neuronal signaling, immune response, inflammatory response, modulation of ion channels, phagocytic defense mechanism, penile erection, and cardiovascular homeostasis and its decompensation in atherogenesis. Recent studies have also revealed a role for NO as signaling molecule in plant, as it activates various defense genes and acts as developmental regulator. In plants, NO can also be produced by nitrate reductase. NO can operate through posttranslational modification of proteins (nitrosylation). NO is also a causative agent in various pathophysiological abnormalities. One of the very important systems, the cardiovascular system, is affected by NO production, as this bioactive molecule is involved in the regulation of cardiovascular motor tone, modulation of myocardial contractivity, control of cell proliferation, and inhibition of platelet activation, aggregation, and adhesion. The prime source of NO in the cardiovascular system is endothelial NO synthase, which is tightly regulated with respect to activity and localization. The inhibition of chronic NO synthesis leads to neurogenic and arterial hypertensions, which later contribute to development of myocardial fibrosis. Overall, the modulation of NO synthesis is associated with hypertension. This review briefly describes the physiology of NO, its synthesis, catabolism, and targeting, the mechanism of NO action, and the pharmacological role of NO with special reference to its essential role in hypertension.

Journal Article↗
PubMed2003

Conjunctival malignant melanoma.

A 65-year-old woman was diagnosed clinically to have a tarsal conjunctival malignant melanoma of the upper eyelid. She also had multiple, diffusely pigmented, flat conjunctival lesions. No local or distant metastasis was detected. She was treated conservatively by a combination of surgery and cryotherapy as this was her only seeing eye. Histopathology of the tumor tissue and biopsy specimens of the flat conjunctival lesions proved them to be conjunctival malignant melanoma and primary atypical melanosis with atypia, respectively. Over a follow-up of two years, no clinical recurrence of the tumor was seen. To conclude, a malignant melanoma arising from the tarsal conjunctiva is extremely rare. The goal of treatment should be eradication of the tumor as well as preservation of a functionally and cosmetically acceptable eye.

Aged↗
PubMed2003

Phthisis bulbi with a large protruding foreign body--a rare complication of penetrating injuries.

Spontaneous extrusion of a retained intraocular foreign body is a rare occurrence. An unusual case is described in a 30-year-old male, where a foreign body remained in the eye for four years and then, as phthisis set in, the foreign body gradually extruded, causing constant irritation of the upper lid. Such a situation has not been documented before. Its management along with the histopathologic features are discussed in the light of the available literature.

Adult↗
PubMedDate not supplied

Evaluation of amniotic membrane grafting in the reconstruction of contracted socket.

PURPOSE: To study the use of amniotic membrane for the reconstruction of mild to moderate grades of contracted socket and compare it to mucous membrane grafting. METHODS: A total of 20 patients with acquired, anophthalmic contracted socket of mild to moderate grades were studied and divided into two groups: the amniotic membrane graft (AMG) group (10 patients) and the mucous membrane graft (MMG) group (10 patients). The preoperative and postoperative measurements of forniceal depth and volume of socket were compared. After surgery, motility of the prosthesis was also compared. RESULTS: The mean preoperative depth of the lower fornix in the AMG group and the MMG group was 1.5 mm and 1.4 mm, and after surgery, at final follow-up was 5.4 mm and 5.5 mm, respectively. The preoperative mean height of the upper fornix in the AMG group and the MMG group was 10.3 mm and 10.7 mm, and after surgery, at final follow-up was 12.6 mm and 13.2 mm, respectively. The mean preoperative volume of the socket was 0.84 ml in the AMG group and 0.80 ml in the MMG group, and after surgery, at final follow-up was 1.43 ml and 1.48 ml, respectively. The various quantitative parameters including motility of the prosthesis were comparable in the two groups. CONCLUSIONS: Amniotic membrane grafting gave cosmetically and functionally acceptable results in cases of mild to moderate grades of anophthalmic socket contraction. The results were comparable to those of mucous membrane grafting.

Adolescent↗