PubMed Health⌕ Search

Biomedical subjects

M Bhat

Publications and source records attributed to M Bhat.

At least 37 records · Page 2Linked to original sources
PubMed1996

Prevalence of incisor trauma in persons 6-50 years of age: United States, 1988-1991.

Traumatic injuries to the teeth are among the most serious of dental conditions, yet little is known about the prevalence of tooth or dental trauma at the national level. The National Institute of Dental Research (NIDR) modified existing indices for specific use in national epidemiologic studies of tooth trauma among both children and adults. The NIDR index was developed not only to track the status of the tooth from sound (no evidence of trauma) through missing due to trauma, but also to reflect selected sequelae of trauma. The index is based on clinical, non-radiographic evidence of tooth inujury and treatment received in the eight permanent incisors, including a positive history of injury obtained from the subject. The trauma assessment index was applied immediately following the caries examination for dentate participants ages 6-50 years old (n=7,707) in Phase 1 of the NHANES III oral examination. This article reports the first national overall and age-specific population-based prevalence of dental trauma among gender, racial, and ethnic groups. There is a higher prevalence of incisal trauma, of both maxillary and mandibular incisors, in males than females, in both the younger and older age groups. The prevalence of incisal trauma of both maxillary and mandibular incisors in whites and blacks in both younger and older age categories is similar. The study found that half of the individuals with trauma had only one incisor tooth classified as having trauma. Males and older age groups showed larger numbers of traumatized teeth. Further study and examination of methodological issues are desirable for additional understanding of incisal trauma in the general population .

Adolescent↗
PubMed1996

Prevalence and distribution of selected occlusal characteristics in the US population, 1988-1991.

The inclusion of occusal traits as part of the oral health component of the Third National Health and Nutrition Examination Survey, Phase 1, 1988-91, provided an opportunity to assess several occlusal characteristics in the US population: diastema > or = 2 mm, alignment of lower and upper anterior teeth, posterior crossbite, overbite, and overjet. Household questionnaires asked whether the individual had ever received orthodontic treatment. Prevalence of clinical measures of occlusal characteristics and orthodontic treatment was estimated for over 7,000 sample persons from 8 to 50 years of age, representing approximately 150 million non-institutionalized people in the United States. These findings present the first estimates of occlusal status of the US non-institutionalized population in more than 25 years. Eight percent of the population had severe overbite of 6 mm or more. The average overbite was 2.9 mm. Maxillary diastemas > or = 2 mm were observed in 19% of 8-11-year-olds, 6% of 12-17-year-olds, and 5% of adults 18-50 years old. Twenty-five percent and 22% of persons had zero mm of malalignment in maxillary and mandibular incisors, respectively. Conversely, 11% and 15% of persons had 6 mm or more displacement of maxillary and mandibular molars, respectively. Posterior crossbite affects less than 10% of this population, and less than 10% had overjet of 6 mm or more. Non-Hispanic black adults had the least amount of malalignment in mandibular incisors. Three times as many non-Hispanic blacks compared with non-Hispanic whites and Mexican-Americans had diastemas > or = 2 mm. Comparisons with published data from the National Health Examination Survey (1966-70) indicated a 20% increase of 12-17-year-olds with overbite in the normal range (0-3 mm). Almost 20% of adults ages 18-50, as well as 18% of children, have had orthodontic treatment.

Adolescent↗
PubMed1995

Sturge-Weber syndrome in pregnancy.

Sturge-Weber syndrome is a rare disease involving a port-wine facial nevus and an associated intracranial venous malformation. There are no reports of this disorder in association with pregnancy in the English literature, and the effects of pregnancy on this syndrome remain unknown. We present a case of Sturge-Weber syndrome diagnosed in the early postpartum period and document the possible deleterious effects of gestation on the neurologic symptoms and ultimate prognosis.

Adult↗
PubMed1995

P-element mutations affecting embryonic peripheral nervous system development in Drosophila melanogaster.

The Drosophila embryonic peripheral nervous system (PNS) is an excellent model system to study the molecular mechanisms governing neural development. To identify genes controlling PNS development, we screened 2000 lethal P-element insertion strains. The PNS of mutant embryos was examined using the neural specific marker MAb 22C10, and 92 mutant strains were retained for further analysis. Genetic and cytological analysis of these strains shows that 42 mutations affect previously isolated genes that are known to be required for PNS development: longitudinals lacking (19), mastermind (15), numb (4), big brain (2), and spitz (2). The remaining 50 mutations were classified into 29 complementation groups and the P-element insertions were cytologically mapped. The mutants were classified in five major classes on the basis of their phenotype: gain of neurons, loss of neurons, organizational defects, pathfinding defects and morphological defects. Herein we report the preliminary phenotypic characterization of each of these complementation groups as well as the embryonic lacZ expression pattern of each P-element strain. Our analysis indicates that in most of the P-element insertion strains, the lacZ reporter gene is not expressed in the developing PNS.

Animals↗
PubMed1995

The incidence of orofacial injuries in sports: a pilot study in Illinois.

This pilot study of sports-related injuries in Illinois confirms that football players do not encounter orofacial injuries as often as other athletes. The authors attribute this to mandatory use of faceguards and mouth protectors in football and recommend that mouthguards be used by all players of contact sports.

Athletic Injuries↗
PubMed1994

Fluoromicroscopic studies of bleomycin-induced intracellular oxidation in alveolar macrophages and its inhibition by taurine.

The mechanism of bleomycin-induced pulmonary fibrosis is not yet clear. Recent studies have shown that alveolar macrophages (AM) can be stimulated by bleomycin in vitro releasing inflammatory cytokines, suggesting that the interaction of bleomycin with AM is an important step in the drug-induced fibrotic process. Bleomycin is known to bind DNA and generate oxygen radicals through complexation with Fe2+ and oxygen. To provide more insight into the cellular oxidative property of bleomycin, we have developed a fluoromicroscopic method using 2',7'-dichlorofluorescin diacetate (DCFHDA) as an oxidative fluorescence probe to study the bleomycin-induced intracellular oxidation in rat AM and the inhibition of the oxidation by taurine, a compound known to inhibit the bleomycin-induced fibrosis. Bleomycin at 5 to 20 micrograms/ml has a moderate stimulatory effect (1.87- to 2.66-fold) on the secretion of superoxide anion. A high concentration of bleomycin (20 micrograms/ml), however, inhibits cell response to zymosan-induced secretion of superoxide anion. At 4 micrograms/ml, bleomycin has no effect on cell membrane integrity or morphology but results in a significant increase in intracellular oxidation. This oxidative process is Fe(2+)-dependent and is accompanied by an increase in intracellular calcium (35 nM). Both the intracellular oxidation and calcium rise induced by internalized bleomycin are inhibited by pretreatment of cells with varying concentrations of taurine (25, 125, and 187.5 microM). The inhibitory effect on intracellular oxidation was found to be 36, 57, and 60%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Regulation of tight junction permeability by calcium mediators and cell cytoskeleton in rabbit tracheal epithelium.

The present study investigates the mechanisms controlling tight junction permeability of the tracheal epithelium, with an emphasis on the regulatory role of intra- and extracellular calcium as well as the cell cytoskeleton. The tracheas were isolated from rabbits and their junctional permeability barrier was investigated in vitro by means of transepithelial electrical resistance measurements and flux measurements of the radiolabeled paracellular tracer, 14C-mannitol. The effects of intra- and extracellular calcium were studied using the calcium ionophore A 23187 and EGTA, and that of the cytoskeleton was investigated using cytochalasin B. Intracellular calcium of the tracheal epithelium was monitored microfluorometrically using the specific calcium indicator, Fura-2 AM (acetoxymethyl ester). The results indicate that the tight junction permeability of the trachea was significantly increased upon treatment with all three of the test compounds, as evidenced by a substantial decrease in transepithelial electrical resistance and an increase in transepithelial flux of 14C-mannitol. The effects of EGTA and cytochalasin B on the tight junction permeability are fully reversible upon removal of the compounds from the bathing media. On the other hand, tissues treated with the calcium ionophore demonstrate a partial or no recovery in membrane permeability, depending on the intracellular calcium levels. Moderate and transient increases in intracellular calcium caused a partial reversibility of the membrane resistance, while high and sustained intracellular calcium levels induce a complete irreversibility of the membrane resistance.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Dental visits for orofacial injury: defining the dentist's role.

There were an estimated 5.9 million episodes of care for orofacial trauma in the U.S. private practice sector in 1991. More than 4 million were seen by general dental practitioners, the rest by specialists. An in-depth understanding of the injuries and the extent and cost of the care could establish a focused injury prevention strategy.

Adolescent↗
PubMed1992

The transport barrier of epithelia: a comparative study on membrane permeability and charge selectivity in the rabbit.

The transport barrier of the epithelial presents one of the major problems limiting the effective use of these tissues as alternate delivery routes for macromolecules such as peptides and proteins. In the present study, two membrane transport properties, namely, the permeability and permselectivity of the shunt pathway, were investigated and compared in various tissues including the nasal, tracheal, bronchial, buccal, rectal, vaginal, corneal, epidermal, duodenal, jejunal, ileal, and colonic epithelia. Membrane permeability was evaluated using a combined method based on electrical conductance and flux measurements of a hydrophilic fluorescent probe, 6-carboxy fluorescein (CF). Membrane permselectivity or the charge discriminating ability of the membrane was evaluated by KCl diffusion potential measurements. The results indicate that all epithelia under investigation possess a relatively high degree of permeation barrier and are highly selective for the absorption of positively charged solutes. Shunt path permeability was found to vary greatly among tissues from different epithelia, whereas membrane charge selectivity was relatively constant in these tissues. A good correlation was observed between membrane electrical conductance and steady-state flux of CF, indicating a paracellular transport of the compound. The rank order of the intrinsic membrane permeability was as follows: intestinal approximately nasal greater than or equal to bronchial greater than or equal to tracheal greater than vaginal greater than or equal to rectal greater than corneal greater than buccal greater than skin. Membrane permselectivity, expressed as the ratio of transport number (positive over negative), ranges from 1.78 for the buccal to 1.33 for the rectal epithelium.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Prevalence of developmental enamel defects in children with cerebral palsy.

Enamel defects observed in primary anterior teeth of 123 children with congenital cerebral palsy (CP) born 1983 through 1985 in four northern California counties were categorized using an adaptation of the Developmental Defects of Enamel Index. Nineteen children (15%) had crowns or loss of tooth substance (LTS) due to attrition. Missing enamel (ME) including horizontal groove, was observed in 39 children (32%). Twenty-four children without ME (20%) had enamel pits, vertical grooves, or colored enamel opacities. Forty-one (33%) had clinically normal enamel. ME children did not differ significantly from those with normal enamel with respect to race, sex, singleton vs twin, severity or type of CP, or presence of dysmorphic features. ME children more often had shorter gestational ages than children with normal enamel. More ME children, even those who were not low in birth weight, were reported by parents to have required neonatal intensive care.

California↗
PubMed1992

Health and family welfare base-line survey in Gokak taluka, 1993: a brief report.

"The Institute of Economic Research undertook [a] base line survey in Gokak taluka [India].... The major objective was to provide a data base for evaluating programme efforts, and developing strategies and plans for the future.... The main object of the study was to provide base-line information on the levels of fertility, family planning, and maternal [and] child health care for the project area...[and] aspects of mortality and morbidity."

Asia↗
PubMed1991

Periodontal health of 14-17-year-old US schoolchildren.

This paper describes the findings related to periodontal health in 14-17-year-old children who participated in the National Survey of Oral Health in US Schoolchildren, conducted by the National Institute of Dental Research (NIDR) during 1986-87. Gingivitis was observed in approximately 60 percent of children in this age group. The proportion of examined sites per child with gingivitis, however, was less than 6 percent. Gingivitis was most common in molar areas in the maxilla and incisor areas in the mandible. Supragingival calculus was observed in nearly 34 percent of the children, and subgingival calculus in approximately 23 percent. The proportion of teeth per child with calculus was approximately 8 percent for supragingival and 4 percent for subgingival calculus. Both types of calculus showed a predilection for molars in the maxilla and incisors and cuspids in the mandible. The mean periodontal attachment loss was 0.33 mm. The teeth most frequently affected by attachment loss of 2 mm or more were maxillary molars and bicuspids, followed by mandibular molars and cuspids.

Adolescent↗
PubMed1990

Consumer product-related tooth injuries treated in hospital emergency rooms: United States, 1979-87.

The database of the National Electronic Injury Surveillance System was used to analyze episodes of consumer product-related traumatic injuries to teeth treated in hospital emergency room in the United States from 1979 through 1987. Results showed a slight but consistent increase in episodes of such injuries during this 9-yr period. Over 75% of such episodes occurred in persons under 15 yr of age. Over 60% of the tooth injuries in such episodes could be crudely classified into the following types by descending rank order: avulsed-, broken-, loosened-, chipped-, intruded-teeth and soft tissue injuries. The most common categories of consumer products and activities associated with such episodes were sports and play, followed by falls on floors, stairs or showers, and bicycles and other wheeled vehicles. The age composition of specific episodes of dental injuries varied considerably for different products and activities, suggesting a need for specific strategies for prevention of episodes of consumer product-related injuries to teeth for different age categories of the population.

Adolescent↗
PubMed1989

Developmental enamel defects in primary teeth in children with cerebral palsy, mental retardation, or hearing defects: a review.

Developmental enamel defects in primary teeth have been found at least twice as frequently in children with cerebral palsy or mental retardation as in control children, and frequently also in children with sensori-neural hearing deficits. The developing tooth germ is sensitive to a range of systemic disturbances, some of which may also affect neurologic development. Because the enamel cannot recover once it is damaged, it may provide a repository of information on the timing and nature of insults potentially affecting other ectodermally derived structures, including the brain. This paper reviews the literature on developmental defects of enamel in primary teeth, asking whether these might be useful as biological markers of the timing and in some cases the nature of insults. Among systemic factors related to development of enamel that might also have implications for neurologic development are certain genetic disorders including tuberous sclerosis, premature birth, neonatal nutritional disturbances (especially hypocalcemia), viral infections (such as rubella and cytomegalovirus during gestation), thyroid disorders, and maternal diabetes. It is concluded that further research is warranted concerning whether developmental defects of dental enamel can be useful markers for the timing of intra-uterine or perinatal events associated with certain neurologic and sensory disorders of children.

Cerebral Palsy↗
PubMed1989

Lack of stability in enamel defects in primary teeth of children with cerebral palsy or mental retardation.

The Developmental Defects of Enamel (DDE) index was used to study the reliability across time of assessment of enamel defects in primary teeth in neurologically handicapped children. Fourteen of the 48 children originally examined were available for re-examination 6 months later. The original findings were confirmed in only 6 of these children (5 with no enamel defects and 1 with an enamel defect). Discrepancies noticed between the 2 examinations in the other 8 children could be explained on the basis of biological processes that occurred during the 6-month interim, namely, attrition, abrasion, crown fracture, caries, and possibly remineralization of a hypomineralized defect. These findings suggest that the optimum time for studying such defects is as soon as possible after the teeth erupt.

Cerebral Palsy↗