Santhosh Kumar - Academia.edu (original) (raw)

Papers by Santhosh Kumar

Indian journal of oral health and ressearch, 2016

The cancer is a major health threat, which is considered as the third major cause of death. In ol... more The cancer is a major health threat, which is considered as the third major cause of death. In old days, childhood cancer was a mortal threat. However, a revolution in medical technology and research work; life expectation is improved. Hence, from 1995 onward, there is increased 5-year survival rate particularly, in children treated with cancer and around 80% attain adulthood. Even in other cancers, recent treatment advances have increased survival rate. However; still there is a lack of awareness and consideration toward long-term consequences in increasing survivors. Hence, merely elimination of cancer from the body is not enough; there is a call to work collectively for the betterment of rest of the life for the survivors. The survivorship project considers the need of time, but narrow work force (8%) of qualified group is the main concern.

Rgo Revista Gaucha De Odontologia, Mar 1, 2011

Objective The purpose of this study was to investigate the epidemiology of periodontal status amo... more Objective The purpose of this study was to investigate the epidemiology of periodontal status among dentate male adults in the general population of Jalore, Rajasthan using the Community Periodontal Index. Methods The condition of the periodontium was assessed by the Community Periodontal Index with use of the Community Periodontal Index probe. A total of 648 male subjects belonging to five age groups, namely 12, 15, 18, 35-44 and 65-74, were selected by stratified cluster sampling technique and examined. Results The proportion of total subjects with healthy periodontium was 9.7% and the mean number of healthy sextants was 1.7. Bleeding on slight provocation was the most commonly observed condition in all age groups, comprising 38.8% of the total subjects. The results showed that the proportions of subjects who reported bleeding, calculus and periodontal pockets decreased steadily with age and a high statistically significant difference was observed among various age groups (p<0.001). Conclusion The results indicate that the study population has more widespread and severe periodontal destruction than other populations. Hence, to maintain periodontal health in this population, appropriate preventive and periodic periodontal therapies should be provided.

Journal of dentistry, Jan 30, 2015

To synthesise data from the literature on the effects of various parent-related characteristics (... more To synthesise data from the literature on the effects of various parent-related characteristics (socio-demographic, behavioural and family environment) on dental caries in the permanent dentition of children. Available studies in which the effects of parent-related characteristics on dental caries experience in the permanent dentition of children aged 6-12 years were evaluated. PubMed, Medline and CINAHL, restricted to scientific articles, were searched in April 2015. English language and time filters (articles published from 2000) were used. A total of 4162 titles were retrieved, of which 2578 remained after duplicates were removed. After review of titles and their abstracts by two independent reviewers, 114 articles were considered relevant for full text review. Of these, 48 were considered for final inclusion. Data extraction was performed by two authors using piloted data extraction sheets. Most of the literature on determinants of dental caries has been limited to socio-economi...

Journal of clinical and diagnostic research : JCDR, 2013

To histologically assess and clinically co-relate the effectiveness of cryogen Tetrafluoroethane ... more To histologically assess and clinically co-relate the effectiveness of cryogen Tetrafluoroethane (TFE) for gingival depigmentation procedure. Twelve patients having unaesthetic gingival melanin pigmentation were included in the study. Gingival tissues of eight patients having gingival melanin pigmentation undergoing gingivoplasty or gingivectomy for crownlengthening were exposed to the cryogen and this was used for the histological examination. Gingivectomies were done after 8, 24, 96 hours and after a week of application of tetrafluoroethane. Four fair skinned patients complaining of unaesthetic gingival hyperpigmentation underwent gingival depigmentation using Tetrafluoroethane cryogen. Histologically after 96 hours of application of cryogen there was complete loss of retepegs and epithelial detachment from the corium was evident. Complete re - epithelialisation was noted after a week and was clinically correlated. We therefore, concluded that histologically tetrafluoroethane can ...

International Journal of Dental Hygiene, 2011

The aim of the study was to determine if frequency of tooth cleaning varies with social group, fa... more The aim of the study was to determine if frequency of tooth cleaning varies with social group, family size, bedtime and other personal hygiene habits among school children. Target population comprised schoolchildren aged 8-16 years of Udaipur district attending public schools. A two stage cluster random sampling procedure was executed to collect the representative sample, consequently final sample size accounted to 852 children. Data were collected by means of structured questionnaires which consisted of questions related to oral hygiene habits including a few general hygiene habits, bed time, family size, family income and dental visiting habits. The results show that 30.5% of the total sample cleaned their teeth twice or more daily and there was no significant difference between the genders for tooth cleaning frequency. Logistic regression analysis revealed that older children and those having less than two siblings were more likely to clean their teeth twice a day than the younger ones and children with more than two siblings. Furthermore, frequency of tooth cleaning was significantly lower among children of parents with low level of education and less annual income as compared with those of high education and more annual income. In addition, tooth cleaning habits were more regular in children using tooth paste and regularly visiting to the dentist. This study observed that tooth cleaning is not an isolated behaviour, but is a part of multifarious pattern of various social and behavioural factors.

Indian Journal of Dentistry, 2012

Dental esthetic needs of patients are increasing with a greater demand on pleasing look. This dem... more Dental esthetic needs of patients are increasing with a greater demand on pleasing look. This demand gets fulfilled not only by having healthy set of dentition but also esthetically improved gingival component. Gingival melanin pigmentation is one of the factors which determine the smile of an individual. Based on the available literature gingival melanin pigmentation can vary depending on whether it is physiological or pathological. Its esthetic importance depends on the skin complexion of the patient and is one of the most important factors for determining the treatment for gingival melanin pigmentation. It is necessary to select an appropriate technique for treating unaesthetic gingival melanin pigmentation of patients and the treatment should cause minimal discomfort and should be effective for a longer period of time. Treatment of gingival melanin pigmentation can be done using scalpel, chemical agents, abrasion, grafts, electro surgery, cryosurgery or lasers. Recent reports on treatment of gingival melanin pigmentation using cryosurgery and lasers show results in terms of ease of use, acceptance and patient comfort to be far superior to other techniques. This literature review is done to classify and explore the recent treatments and future procedures available for depigmentation.

$Research paper thumbnail of Elastic modulus of Al–Si/SiC metal matrix composites as a function of volume fraction$

Journal of Physics D: Applied Physics, 2009

IEEE Transactions on Information Theory, 2013

This article considers the performance of digital communication systems transmitting messages ove... more This article considers the performance of digital communication systems transmitting messages over finite-state erasure channels with memory. Information bits are protected from channel erasures using error-correcting codes; successful receptions of codewords are acknowledged at the source through instantaneous feedback. The primary focus of this research is on delay-sensitive applications, codes with finite block lengths and, necessarily, non-vanishing probabilities of decoding failure. The contribution of this article is twofold. A methodology to compute the distribution of the time required to empty a buffer is introduced. Based on this distribution, the mean hitting time to an empty queue and delay-violation probabilities for specific thresholds can be computed explicitly. The proposed techniques apply to situations where the transmit buffer contains a predetermined number of information bits at the onset of the data transfer. Furthermore, as additional performance criteria, large deviation principles are obtained for the empirical mean service time and the average packet-transmission time associated with the communication process. This rigorous framework yields a pragmatic methodology to select code rate and block length for the communication unit as functions of the service requirements. Examples motivated by practical systems are provided to further illustrate the applicability of these techniques.

IEEE Transactions on Communications, 2014

Carcinogenesis, 2004

Curcumin, the yellow pigment derived from Curcuma longa, is known to induce apoptosis of several ... more Curcumin, the yellow pigment derived from Curcuma longa, is known to induce apoptosis of several cancer cells. However, many cancer cells protect themselves by over-expressing antiapoptotic proteins such as Bcl-XL or Ku70. To study their role in curcumin-induced apoptosis, human colon cancer cells (SW480) were made to overexpress or under-express Bcl-XL (by stable transfection) and Ku70 (by transient transfection) using plasmid constructs that express their genes in sense or antisense orientation, respectively. Stable cells that express Bax [Bax-GFP (green fluorescent protein)], a proapoptotic member of the Bcl-2 family, were also established. Curcumin-induced cell death and nuclear condensation was more in AsBcl-XL and AsKu70 cells that under-express Bcl-XL and Ku70, respectively, compared with the vector-transfected cells. Bcl-XL and Ku70 protected the cells by inhibiting the release of cytochrome c, Smac (second mitochondria derived activator of caspase) and apoptosis inducing factor (AIF), and the activation of caspases 9, 8 and 3 triggered by curcumin. AsBcl-XL and AsKu70 cells were more sensitive to curcumin through enhanced activation of caspases 9 and 3 and release of cytochrome c, Smac and AIF. Curcumin-induced activation of caspase 8 was blocked by Ku70 but not by Bcl-XL. However, caspase 8 activation by curcumin was accelerated in both AsBcl-XL and AsKu70 cells suggesting a possible feedback activation of caspase 8 by caspase 3. Bax-GFP cells were highly sensitized when Ku70 was down-regulated supporting the reported role of Ku70 in the retention of Bax within the cytosol. The study reveals the potential of antisense inhibition of antiapoptotic proteins as an effective strategy to tackle chemoresistant cancers with curcumin.

Carcinogenesis, 2003

We have shown earlier that heat shock renders human colon cancer cells resistant to curcumin-indu... more We have shown earlier that heat shock renders human colon cancer cells resistant to curcumin-induced apoptosis, but the contribution of individual heat shock proteins (hsps) to this resistance has not been tested. High expression of hsp27 and hsp70 in breast, endometrial and gastric cancers has been associated with metastasis, poor prognosis and resistance to chemo-or radiotherapy. In this study, SW480 cells were transfected with hsp70 cDNA in either the sense or antisense orientation and stable clones were selected and tested for their sensitivity to curcumin. The cells were protected from curcumin-induced cell death by hsp70 while cells harboring antisense hsp70 (Ashsp70) were highly sensitive to curcumin. Curcumin-induced nuclear condensation was less in hsp70 but more in Ashsp70 cells when compared with control vectortransfected cells. Loss of mitochondrial transmembrane potential induced by curcumin was further accelerated by antisense hsp70 expression and hsp70 restored it partly. Ashsp70 cells released more cytochrome c, AIF and Smac from mitochondria upon curcumin treatment than control cells. hsp70 partly prevented the release of AIF but not the other proteins. Activation of caspases 3 and 9 induced by curcumin was also inhibited by hsp70, whereas more activation could be seen in Ashsp70 cells, although caspase 8 activation was unaffected by changes in hsp70 expression. Curcumin-induced cleavage of PARP and DFF45 was inhibited by hsp70 but enhanced in Ashsp70 cells. The present study demonstrates the potential of hsp70 in protecting SW480 cells from curcumin-induced apoptosis and highlights that silencing the expression of hsp70 is an effective approach to augment curcumin-based therapy in cancers that are resistant due to hsp70 expression.