Gaso-transmitter hydrogen sulphide: Potential new target in pharmacotherapy.

Research in the last two decades has transformed the way hydrogen sulphide (H2S) is perceived from a noxious gas to a gaso-transmitter with a vast potential in pharmacotherapy. H2S is synthesized in various body-systems using the enzymes cystathionine beta-synthase and cystathionine gamma-lyase; either of these being the predominat enzyme in a particular system. H2S may be one of the physiological modulators of blood pressure in humans. The gas relaxes the vascular smooth muscle cells by opening up KATP channels. Moreover, it suppresses the proliferation of vascular smooth muscle cells. H2S may also be contributing in the protection afforded by ischaemia-preconditioning. Testosterone is thought to be responsible for the higher central nervous system level of H2S in males. In the central nervous system, H2S is implicated in Alzheimer’s disease, epilepsy, stroke and Down’s syndrome. Insulin secretion is associated with a decrease in the H2S levels. Raised H2S is detrimental in acute pancreatitis as well as in septic shock. Recently, H2S-releasing derivatives of certain drugs have shown promise in protection against gastric ulcer and in inflammatory bowel disease. The beneficial effects of certain sulphur containing herbs like ginseng and garlic may be mediated via H2S. In future, development of specific drugs modulating H2S levels may prove beneficial in varied disorders.

Comparative evaluation of shear bond strength of different bracket base designs in dry and wet environments.

One hundred and thirty five extracted premolars were selected and bonded with three types of brackets with different bracket base designs viz. Gemini (foil mesh), Miniature twin (Laser etched) and Mini Dynalocks (Integral base). These brackets were bonded with Transbond XT adhesive using two types of primers viz. Conventional Transbond XT in dry conditions and M.I.P in dry and wet environments. The specimens were tested for SBS using Instron machine at C.I.P.E.T. (Amritsar), Punjab. Results were statistically analyzed. RESULTS AND DISCUSSION: The Miniature twin brackets revealed higher SBS values as compared to Gemini and Mini Dynalock in dry and wet conditions. All the groups showed higher SBS values in dry conditions as compared to wet conditions respectively. The Gemini and Mini Dynalock brackets showed very little difference of SBS values. CONCLUSION: Miniature twin brackets with laser etched bracket base in dry and wet environments have revealed the highest SBS values. All the groups have revealed clinically acceptable SBS value of above 8 MPa in moist conditions.

Maxillary expansion--an interceptive modality in mixed dentition.

Maxillary expansion is a very useful procedure for arch length augmentation, posterior crossbite treatment and removing cross arch interferences. Removable appliances are in the realm of a pedodontist and general dentist. However, one should be aware of the problems arising at an early age of the child, should be able to properly diagnose the condition and if required, a timely referral to a specialist is also expected.