A QSAR study on a series of simplified digitalis-like compounds acting on Na+,K+-ATPase

Among the cardiotonics (agents against congestive heart failure), the most important group is of the digitalis cardiac glycosides, but since these compounds suffer from a low therapeutic index, attention has been paid to investigating safer cardiotonic agents through the inhibition of Na+,K+-ATPase, the mechanism by which the digitalis cardiac glycosides elicit their action. Recently, a series of perhydroindenes were studied for their Na+,K+-ATPase inhibition activity. We report here a QSAR study on them to investigate the physicochemical and structural properties of the molecules that govern their activity in order to rationalize the structural modification to have more potent drugs. A multiple regression analysis reveals a significant correlation between the Na+,K+-ATPase inhibition activity of the compounds and Kier’s first order valence molecular connectivity index of their R5-substituents and some indicator parameters, suggesting that the R5-substituents of the compounds containing atoms with low valence and high saturation and the R1-substituents having =N−O− moiety will be conducive to the activity.

Intraosseous neurilemmoma of L2 vertebra--a case report.

Intraosseous neurilemmoma (schwannoma) is a rare bone tumor with incidence less than 0.2% of all primary bone tumors. It is a benign neoplasm arising from the schwann cells of the nerve sheath. When they occur, they are usually found in the mandible. This paper reports an unusual occurrence of intraosseous neurilemmoma in L2 vertebral body. This patient presented with complaints of backache and progressively increasing weakness in both lower limbs. Roetengenograms showed an osteolytic lesion of L2 vertebra localized in the left half of the body and pedicle. Computed tomograph revealed a large soft tissue component of the tumor mass with thecal sac compression. A computed tomograph assisted needle biopsy revealed the tumor to be neurilemmoma. Subsequently, during decompression, it was possible to shell out tumor from surrounding tissues. Remaining tumor was curettedfrom bone and the cavity packed with autograft. The recovery was uneventful with incorporation of graft. The aim of this article is to highlight intraosseous neurilemmoma as a possible differential diagnosis in bony tumors. Intraosseous neurilemmoma of lumbar vertebrae is an extremely rare occurrence and till date only four cases are reported in English literature.

Quantitative structure-activity relationship studies on benzodiazepine receptor binding: investigation of interaction model.

With a view to providing perfection to the benzodiazepine receptor model proposed earlier [S P Gupta, R N Saha & V Mulchandani (1992) J. Mol. Recog, 5, 75-80] a few more QSAR studies on a series of 9-benzylpurines and tetracyclic 1,4-benzodiazepine derivatives have been made. The models showing the interaction of these compounds with the receptor are proposed. It is found that the receptor model, unlike the one proposed earlier, requires the presence of a polar site along with all the other essential sites.

Residual poliomyelitis of lower limb-pattern and deformities.

The pattern of muscle paralysis and paresis in the lower limbs has been studied in 1356 children with 1800 poliomyelitic limbs, revealed that more than two-third (68 = 55%) muscles were affected, with the ratio of paresis and paralysed muscles were 1.89:1.00. The muscles most frequently affected were tibialis anterior (1516), quadriceps (1465) and tibialis posterior (1435) while tibialis anterior (1070), tibialis posterior (820) and quadriceps (766) were most commonly paralysed in descending order. The tibialis anterior which leads in paralysis group, has come last in order of frequency of paresis. The highest segmental incidence of affection of muscles found in second to fourth lumbar segments while muscle paralysis is found in fourth lumbar spinal segment. The commonest deformities encountered in residual poliomyelitis are flexion-abduction contracture hip, flexion contracture knee and valgus deformity foot.

Tibial condylar fractures treated with traction and early mobilisation (report on study of 75 cases).

Seventy-five cases of tibial condylar fractures irrespective of type of fractures were treated on a purely conservative line of management, consisting of traction and early mobilisation. The follow-up ranged from 6 months to 10 years; 67 cases had satisfactory results. Causes of unsatisfactory results were stiff knee, flexion deformity, osteo-arthritis and ligamentous instability.