Expression of matrix metalloproteinases (MMP-1, MMP-2 and MMP-9) and their inhibitors (TIMP-1 and TIMP-2) in oral submucous fibrosis.

Immunohistochemical staining of formalin fixed, paraffin embedded tissue sections of OSF for MMPs-1,2,9 and their tissue inhibitors TIMP-1and 2 was performed using monospecific antibodies coupled with gelatin zymography (MMP-2 and 9) for measuring enzymatic activity quantitatively and for distinguishing the active from the inactive variants of enzymes. The present study, contrary to earlier reports, recorded statistically significant increase in the levels of stromal expression of MMP-1, MMP-2 and MMP-9 and TIMP-1 and TIMP-2 using monospecific antibodies reacting against tissue antigens.The simultaneous increase in reactivity of MMPs and TIMPs poise difficulty in interpretingthe results of this study. The possible reasons for this result, against the backdrop of existing knowledge, were attempted in this study.

Radiolabelled monoclonal antibodies against human cardiac myosin.

Myocardial infarction (MI) can be monitored using several protein markers including human cardiac myosin (HCM). Monoclonal antibodies were raised against HCM by hybridoma technique. Antimyosin antibody producing clones were identified by ELISA and monoclonality was established by limiting dilution. The antibodies were purified, isotyped and their cross reactions with myosin from other species were estimated. All the clones showed negligible cross reaction with rabbit myosin, but reacted with bovine skeletal myosin to different extents (40-100%). The most avid antibody Mab 4G4 which also strongly reacted with rat cardiac myosin, was labelled with 125I using different oxidising agents such as iodogen, chloramine-T and lactoperoxidase. More than 95% pure radiolabelled antibody could be obtained by gel filtration. The immunoreactivity was retained. Mab 4G4 was also labelled with 99mTc using stannous tartrate as the reducing agent. Radiolabelling yield was approximately 60%, the purity was >95%. Both the radiolabelled preparations were tested for biodistribution in rats--both normal and those with induced MI. Approximately 0.7 % of the injected activity/g was found in the infarcted region and the accumulation of activity in the infarcted heart was 1.5 times that in the normal heart. A very high percentage of activity (80%) accumulated in the thyroid. With further optimisation of labelling and use of F(ab')2 fragments, better delineation of the infarct sites may become possible.

Apoptosis: future directions in cancer therapy.

Cancer as a multifactorial disease results in gain of immortality due to defective apoptosis. The primary mode of cell death by apoptosis induced by various modes of treatment often fail in vivo. The in vitro environment is less complex while the in vivo environment is influenced by various external regulatory signals besides the existence of multiple, parallel and independent apoptotic pathways. Further, specific preference for an apoptotic pathway in a certain cell type would significantly alter the apoptotic responses. Identification of defects in preferred pathways and choosing alternative and potentially inducible pathways would help in deciding on apoptosis-based treatment protocols. Mechanisms involved in the execution of apoptosis may also not be unique to apoptotic pathways since similar events, possibly with strict control, do occur during mitosis. Further evaluation may yield new dimensions to apoptosis and apoptosis-based therapy.

Use of Traditional Eye Medicines by corneal ulcer patients presenting to a hospital in South India.

PURPOSE: To investigate the nature and frequency of use of Traditional Eye Medicine (TEM) for corneal ulcer in patients from predominantly rural background. METHODS: We documented the the use of TEM by corneal ulcer patients presenting to a tertiary eye-care centre in South India during two months of 1996. RESULTS: Of 283 patients enrolled in the study, 135 (47.7%) of the patients used TEM. There was no difference with regard to age and sex distribution of patients using TEM and those who did. Patients with history of trauma were more likely to use TEM. Common forms of TEM used were human breast milk 61(45.2%), leafy matter 40(29.6%), castor oil 16 (11.9%), and hen's blood 8 (5.9%). CONCLUSION: Though the awareness of intraocular lens implantation for cataract surgery is very high in this segment of the population, it is still tragic that an awareness of primary eye care following trauma has not been created. Health education is mandatory to prevent this avoidable cause of blindness.

Characteristics of a 60K gelatinase involved in rat mammary gland involution.

In order to study the role of matrix degrading enzymes in modulating cell matrix interaction, an understanding of the characteristics and regulation of their activity is useful. A number of matrix degrading metalloproteinases are involved in modulating the cell-ECM interactions during the involutory phase of mammary gland resulting in its remodelling. Zymographic studies showed that three types of gelatinases (60K, 68K and 130K) occur during the different phases of involution. The 60K gelatinase which appeared on the fifth day of involution has been purified by affinity chromatography over gelatin sepharose. Zymographic and radiolabelled substrate digestion studies at different pH and in presence of different cations showed that the activated form of this gelatinase is a Ca2+ dependent neutral matrix metalloproteinase capable of cleaving collagen I and collagen IV. Immunocytochemical studies showed that the enzyme is localised at pericellular/extracellular sites.