Biomedical subjects

Mira Mohanty

Publications and source records attributed to Mira Mohanty.

5 recordsLinked to original sources

PubMed2005

Evaluation of the effect of incorporation of dibutyryl cyclic adenosine monophosphate in an in situ-forming hydrogel wound dressing based on oxidized alginate and gelatin.

Cyclic adenosine monophosphate (cAMP) has long been regarded as a second messenger and a regulator of human keratinocyte proliferation. To explore more effective wound management, dibutyryl cyclic adenosine monophosphate (DBcAMP), a lipophilic analog of cAMP was incorporated into an in situ-forming hydrogel wound dressing based on periodate-oxidized alginate and gelatin. In vitro release of DBcAMP from the matrix into phosphate buffered saline was slow and increased with time. Only 50-60% of the compound was released into the medium over a period of 2 days suggestive of a sustained release into the wound bed over a period of few days. The wound-healing efficacy of the DBcAMP-incorporated dressing was evaluated on experimental full-thickness wounds in a rat model. It was found that dressing promoted wound healing leading to complete re-epithelialization of wounds within 10 days, whereas control wounds took 15 days for complete re-epithelialization. Data obtained in this study showed that the presence of DBcAMP accelerated healing and re-epithelialization of full-thickness wounds.

Alginates↗

PubMed2004

Comparative evaluation of absorbable hemostats: advantages of fibrin-based sheets.

Bioactive hemostats and wound dressings consist of either inherently active materials or act as delivery vehicles which contain such materials. Fibrin is a natural hemostat and scaffold, guiding the direction of wound contraction and closure. In order to improve the ease of application of liquid fibrin glue, we have made a freeze-dried form of polymerized fibrin that supports hemostasis and wound healing. The bleeding from the middle ear artery of rabbits was found to be arrested instantaneously on application of fibrin sheets, even when the animal was heparinized systemically. As the fibrin sheet was found to be fragile, gelatin was incorporated to the sheet and thus the mechanical stability was improved without compromising the hemostatic effect. The efficacy of the fabricated fibrin and fibrin-gelatin sheets to seal traumatized rat liver was compared with commercially available hemostats, Abgel (cross-linked gelatin) and Surgicel (cross-linked cellulose). Tissue compatibility of all the hemostats was studied by analyzing the liver tissue 15 days after application. While the hemostatic effect was best with fibrin and fibrin-gelatin sheets, both Surgicel and Abgel were not capable of arresting the bleeding quickly. Gross analysis of tissue on the 15th day of application, visibly, Abgel was not only degraded but resulted in severe adhesions of internal organs and histologically capsule formation around the implant was evident. Though Surgicel was also seen as cream soft material on the site of application that joined two pieces of liver, there was no adhesion of other internal organs and histologically, immune reaction and foreign-body-type giant cells were present in large amounts. Fibrin was not found grossly on application site whereas fibrin-gelatin was seen as a small white spot. Granulation tissue formation and cell migration into the fibrin-based sheets were evident, and therefore, fibrin-based sheets are not only efficient hemostats but showed optimum degradation and wound healing.

Animals↗

PubMed2003

Fibrinolysis inhibitors adversely affect remodeling of tissues sealed with fibrin glue.

Experiments have been carried out to determine if aprotinin and epsilon -amino caproic acid increases the quality of Fibrin glue. A rat model was used for tissues such as liver and skin while rabbits were used for application of glue in dura mater. Apposition of all the tissues, glued with fibrin was found to be good and remnants of the polymerized fibrin were seen even on the seventh day of application, though inhibitors were not incorporated with the glue. In skin, excessive amounts of fibrin remained as a result of addition of aprotinin and epsilon -amino caproic acid, as compared to the glue applied without any inhibitor. After dural sealing, the wound repair and new bone formation at craniotomy site progressed well in the fibrin glue applied area as compared to the commercially available glue that contained aprotinin. The adhesive strength of the glue without or with fibrinolysis inhibitors was found to be similar, after 1h grafts on rat back. The observations from this study suggests that the use of aprotinin with fibrin glue may not be required because, even liver tissue that is known to have high fibrinolytic activity was sealed and repaired well in the absence of plasminogen inhibitors. On the other hand, it was found that if inhibitors were added, nondegraded matrix remained in the tissue even after 15 days and affected migration of repair cells. Thus, the inhibition of fibrinolysis after fibrin glue application is found detrimental to wound healing.

Aminocaproic Acid↗

PubMed2003

Spinal fixation device: a 6-year postimplantation study.

Long-term tissue response to a metal device is described here. The components of a spinal fixation device were removed 6 years after implantation, following the need for revision surgery after a fall. Scanning electron microscopy (SEM) revealed changes in surface topography of the metal. Examination of the adjacent tissue showed a chronic inflammatory response with occasional metal debris. Immunohistochemistry identified the predominant macrophages and abundant neovascularization. The presence of macrophages in tissues adjacent to the implants, in an otherwise asymptomatic person, is noteworthy.

Bone Plates↗

PubMedDate not supplied

Characterisation and quantification of mucosal vasculature in oral submucous fibrosis.

AIM: Quantitative assessment of the mucosal vascularity in oral sub mucous fibrosis (OSF) by image analysis using OPTIMAS ver 6.0 software. The vascularity was assessed by estimating (a) the mean vascular density, (b) the mean vascular area percentage, and (c) the mean vascular luminal diameter. SUBJECT AND METHODS: Twenty (20) OSF and ten (10) age and sex matched healthy volunteers comprised the study group. The 5 microm thick H and E stained mucosal sections were examined and quantified in an image analyzer for number, size, density of vessels, and percentage of vascular area using an area morphometry tool. ANOVA is used to test equality of several means without affecting Type 1 error. RESULT: The mean vascular density is found to be more or less same in the test and control samples (F = 0.82, P>0.05). The mean vascular percentage area shows an increasing trend as the disease progresses (F = 8.63, p<0.01). The mean vascular luminal diameter also shows an increasing trend as the disease progresses (F = 34.1, p<0.001). CONCLUSION: The usual tissue reaction resultant to ischaemia / hypoxia does not seem to operate in this disease, which is preconditioned by significant stromal changes as part of the disease process. The mean vascular dilatation noted is assumed to be an adaptive response to compensate tissue ischaemia/hypoxia.

Biopsy↗