Effects of tetracycline-containing gel and a mixture of tetracycline and citric acid-containing gel on non-surgical periodontal therapy.

Aims and Objectives: The purpose of this study was to assess the clinical and microbiological effects of a newly developed root-conditioning gel system containing tetracycline and a mixture of tetracycline and citric acid on non-surgical periodontal therapy. Materials and Methods: Four anterior teeth from four quadrants with a probing depth of 4-6 mm, in each of the 20 subjects with chronic periodontitis, were subjected to four different modalities of treatment. A total of 80 teeths were divided into four groups of 20 teeth each taken from separate quadrants, on the basis of one of the following four treatments: (1) Root planning alone in first quadrant (RP group); (2) tetracycline-containing gel in the second quadrant (TCG group); (3) root planning plus tetracycline-containing gel in third quadrant (RP + TCG group); (4) root planning plus a mixture of tetracycline and citric acid-containing gel in fourth quadrant (RP + TC-CAG group). Plaque index (PI), sulcular bleeding index, probing pocket depth, and clinical attachment level were measured for 0 day, 8 th week, and 12 th week, respectively. Subgingival plaque samples from each site were collected at the same visits and examined with dark field microscope for proportions of motile rods and spirochetes. Results: From 0 day to 12 th week, PI, sulcular bleeding index, probing pocket depth, and clinical attachment levels decreased significantly in all the groups. From 0 day to 12 th week, RP + TC-CAG group showed a significantly higher change in the PI score. From 0 day to 12 th week, RP group showed a significantly higher change in sulcular bleeding index score. A significant decrease in probing pocket depth and gain in clinical attachment level was noted at 12 th week in RP + TC-CAG group compared to the other groups. A significant decrease in the proportion of motile rods was found primarily in the RP + TC-CAG group. There was a decrease in the proportion of spirochetes in all the groups. Conclusion: The results indicated that the use of a mixture of tetracycline and citric acid-containing gel was effective in improving gingival health and in changing subgingival microflora.

Utility of the Malayalam translation of the 7- minute screen for Alzheimer's disease risk in an Indian community.

Background: Alzheimer's disease (AD) is suspected to be currently under-diagnosed in India, thus the need for a brief, effective screening test for the condition. Aims: We aimed to test the Malayalam translation of the 7-Minute Screen (7MS) for detecting those at high risk for AD and to report on the subscores used to derive the Alzheimer's risk score. Setting and Design: This study was performed in Kerala State amongst young university students and elders in residential care homes. Materials and Methods: Two hundred and eighty-two volunteers were tested, 178 young controls (aged 20-29) and 104 literate elders, (55-92 years). None were clinically diagnosed with AD. Statistical Analyses: Elders and controls were assessed as High or Low AD Risk with the published 7MS algorithm. Performance was compared between groups with ANOVA. Results: The algorithm estimated high (n = 61/104) or low (n = 40/104) AD risk in the elderly. Significant differences were found between controls, low- and high-risk groups on all four components of the screen (Orientation: F = 131.1, Enhanced Cued Recall: F = 23.4, Clock Drawing: F = 65.1, Verbal Fluency: F = 15.7, P P Conclusions: The 7MS may be a useful screening test for cognitive impairment in India. Suggestions are given for revising the 'risk algorithm' for more appropriate AD risk assessment in this population.

Effect of pyridoxine deficiency on the structural and functional development of hippocampus.

In this study it was attempted to understand the effect of pyridoxine deficiency on the structural and functional development of the hippocampus. Hippocampus has been closely associated with complex neuroendocrine control of physiological activities as well as behavioural responses including learning process and memory retention. Prenatal, preweanling and weanling deficiency of pyridoxine was induced in the experimental rats by feeding dams with diet deficient in pyridoxine during pregnancy and lactation. The general growth profile for pyridoxine deficient (PD) rats is compared with control ones. The structural changes in the hippocampus of pyridoxine deficient rats was investigated using the histological techniques. Hippocampal electrical activity was recorded from in vitro brain slice preparation. The study clearly showed the structural impairment in the hippocampus of PD rats. These anatomic anomalies might be related to poor neurointegrative development and neurophysiological deficits that occur in young one. The electrical activity recorded from hippocampal slices of PD rats showed significant variation when compared to controls. Pyridoxine deficiency is common in pregnant women who used anovulatory steroids before pregnancy. The pyridoxine deficiency of the mother may result in permanent behavioural abnormality and intellectual deficit in the progeny.

Heart rate in female rat in response to snout contact by normal, gonadectomised and testosterone--pretreated gonadectomised male.

The question whether or not there will be an enhanced autonomic response in terms of heart rate in female rat, during sexual encounter with male rat was investigated. The heart rate recorded from partially restrained estrous female rat before and after the snout contact by the normal male rat showed a significant rise. There was no such rise in response to the snout contact by neonatally gonadectomised male rat of the same age as that of normal male. Treatment of testosterone propionate given to the gonadectomised male twelve hours prior to the experiment did not bring about significant rise in the heart rate of the estrous female. It is apparent that the perturbation in the structure of sexually dimorphic medial preoptic area (MPOA) in the male rat as a result of neonatal gonadectomy obliterates certain essential cues such as pheromone(s), visual and ultrasound communications which normally elicit a rise in the heart rate of the estrous female during sexual encounter.

Effect of pyridoxine deficiency on maturation of neuromotor coordinations.

In the present study the effect of preweaning pyridoxine deficiency indicates that the body weight and brain weight of pyridoxine deficient rats were significantly lower when compared to the control rats. Onset and stabilisation of reflex reactions were also delayed in the pyridoxine deficient rats. Maturation of neuromotor coordination in the vitamin deficient group was significantly slow as compared to the control groups. This suggests that the importance of maternal pyridoxine supplementation cannot be overlooked in pregnant women especially after prolonged use of anovulatory steroids.

Involvement of active site in self-association of proteins: a case of alpha-chymotrypsin.

The self-association of proteolytic enzymes can be looked upon as an interesting possibility of the manifestation of enzyme-substrate complex. Hence the involvement of active site in such processes is a centre of investigation for many years. In the case of alpha-chymotrypsin, considerable controversy exists with regard to the involvement of active site of the enzyme in its self-association. A historical perspective of the problem and an overview of the available evidence, for and against, is presented and critically analysed. Despite contradicting observations, accumulated evidence indicates that His-57 and Ser-195 at the active site are involved, at least partially, in the self-association; a few other groups such as Tyr-146 and Met-192 are also involved in such processes.

Self-association of α-chymotrypsin: Effect of amino acids.

The concentration-dependent self-association of α-chymotrypsin is known to be influenced by various factors including the presence of small molecules and autolysis products. In this connection the effect of various amino acids on the self-association of α- chymotrypsin has been studied, as a point of interest, by measuring the sedimentation coefficient of α-chymotrypsin. The influence of an amino acid is seen to be governed by the nature of its side chain. Some amino acids do not affect the self-association of α- chymotrypsin at all while some affect it moderately and some others considerably. Functional groups such as the – OH group of Ser or the phenolic ring of Tyr do not seem to influence self-association behaviour. Based on these effects, amino acids could be categorized into 3 groups. Activity studies in the presence of amino acids indicate that the site of self-association and the active-site are probably mutually exclusive.