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Biomedical subjects

A Joshi

Publications and source records attributed to A Joshi.

At least 163 records · Page 9Linked to original sources
PubMed1994

Effect of prochlorperazine as a sensitizer of rat skin on radiation-induced AMP metabolism.

The role of AMP was investigated in radiosensitization by the use of prochlorperazine in normal rat skin. AMP metabolism was evaluated by estimating the level of activities of 5' nucleotidase vis-à-vis protein, DNA and RNA contents in prochlorperazine-treated plus irradiated skin. To study radiation-induced changes in the skin, the extent of lipid peroxidation was measured in terms of enzyme lipid peroxidase. After irradiation, lipid peroxidase activity was observed to increase in prochlorperazine-treated rat skin. Subsequently the level of 5' nucleotidase was found to decrease in drug-treated plus irradiation skin. Similarly, the suppression in the levels of DNA, RNA and protein contents increased when the rat skins was irradiated in the presence of sensitizer prochlorperazine. The cytological examination, which revealed the extent of the lesions occurring in the normal rat skin, and the biochemical examination demonstrated increased cellular lethality in prochlorperazine-sensitized skin after irradiation. The results suggest that prochlorperazine probably sensitizes the normal skin tissues to radiation by inhibiting AMP metabolism via hydroxy-radical-induced decrease in DNA, RNA and protein metabolism.

5'-Nucleotidase↗
PubMed1993

Modulation by ascorbic acid of the cutaneous and hepatic biochemical effects induced by topically applied benzanthrone in mice.

Modulation of biochemical markers by ascorbic acid was investigated in mice to which benzanthrone (BA) was applied topically (150 nmol/mouse) twice a week for 34 wk. After BA exposure without ascorbic acid, in the skin there were significant decreases in the activities of aryl hydrocarbon hydroxylase (AHH; 38% decrease relative to controls) and ethoxyresorufin-O-deethylase (EROD; 39%), and enhancement of the activities of quinone reductase (41% increase), tyrosinase (82%) and histidine decarboxylase (HDC; 190%). BA exposure also caused significant inhibition of hepatic AHH, EROD and glutathione-S-transferase activities, with concomitant increases in the activities of histidase (52%) and HDC (58%). Ascorbic acid given orally (5 mg/mouse) or topically (1 mg/mouse) twice weekly for 34 wk to BA-treated mice resulted in substantial protection against the effects of BA on these enzyme markers in both the skin and the liver. These results suggest that ascorbic acid could be useful in preventing the biochemical and toxicological manifestations caused by BA in laboratory animals.

Administration, Topical↗
PubMed1993

Oral health status of the elderly in New England.

The New England Elders Dental Study (NEEDS) reports the prevalence, extent and severity of oral diseases and conditions among a representative sample of community-dwelling elders age 70 and older residing throughout the six New England states. In-home, full-mouth examinations were conducted by four calibrated dentists who used National Institute of Dental Research (NIDR) standardized disease measures plus additional diagnostic codes on all tooth surfaces. Only 37.6% of elders age 70 and older were edentulous, while dentate elders had a mean number of teeth per person ranging from 21.5 to 17.9 across age and gender cohorts. The prevalence of untreated coronal decay in elders with teeth was 28% in female elders and 34% in male elders. More than 90% of all elders with teeth had coronal fillings and 22% exhibited untreated root caries. Periodontal destruction was substantial, with 66% of dentate elders exhibiting moderate periodontal pockets (4-6 mm) while 21% exhibited severe periodontal pocketing (> 6 mm). Comparisons with national surveys suggest that periodontal disease prevalence and severity appear to have been underestimated in previous national studies of the elderly. Because of aging and tooth retention trends, the periodontal disease problem of the elderly may be increasing in the face of dentists' tendency to underdiagnose the periodontal diseases, legal constraints on dental hygienists to independently treat them, and inadequate funding for conservative nonsurgical therapies.

Aged↗
PubMed1993

Root caries incidence and associated risk factors in middle-aged and older adults.

Data from population-based longitudinal studies required to assess the incidence of root caries and associated risk factors are sparse in the literature. To this end, a group of 130 middle-aged and older adults were examined for root caries at baseline and at a follow-up visit between nine and 24 months (median: 16 months). Dental examinations were conducted by one examiner at a Tufts dental clinic using NIDR defined diagnostic criteria. Fifty percent of subjects in this study population developed one or more new root caries lesions over the follow-up period. Also, an annualised increment of 0.60 (SD: 0.72) decayed and filled surfaces per person was observed for the 45-59 year old group while the 70+ group showed an annualised increment of 1.38 (SD: 1.97) DFS in this study. Multivariate logistic regression analysis identified past root caries experience, high plaque score, and high number of teeth (> = 22) to be positively associated with new root caries (p < 0.05).

Age Distribution↗
PubMed1993

Caries prevalence in xerostomic individuals.

Saliva, via its lubricating, cleansing, remineralizing, antibacterial, and buffering actions, is an important protective factor for both dentition and soft tissue. Xerostomia is commonly found in older individuals due to the use of medications or medical conditions, such as Sjögren's, which directly affect salivary gland function. A xerostomic subgroup (n = 60), mean age = 60, 66 per cent female) of the Nutrition and Oral Health Study (n = 370) was reexamined for caries. Unstimulated and two-per-cent citric-acid stimulated parotid and submandibular/sublingual salivary flow rates were determined. This group was matched for number of teeth, age, sex, and alcohol and smoking habits with a medication-free subgroup (n = 60). Active root and coronal caries were found to be significantly higher in the xerostomic subgroup than in a matched subgroup of medication-free individuals. The mean DFS for the xerostomic subgroup was 45.4 +/- 21.7 for coronal caries and 5.3 +/- 5.8 for root caries. The mean number of teeth was 21.8. The mean DFS in the medication-free subgroup was 36.5 +/- 22.1 for coronal caries and 3.2 +/- 3.2 for root caries. The mean DFS in the xerostomic subgroup for coronal and root caries was statistically significantly higher (p < 0.05). The odds ratio was 2.89 for coronal caries and 3.27 for root caries in the xerostomic versus the medication-free subgroup. Caries varied inversely with salivary flow rate. The difference in flow rates for those in the lowest and highest quartile for coronal caries experience (DFS) in the xerostomic subgroup was found to be statistically significant (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗