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Biomedical subjects

S R Moore

Publications and source records attributed to S R Moore.

At least 19 recordsLinked to original sources

Genomic instability and the role of radiation quality.

Genomic instability (GI) is a hallmark of tumorigenic progression and is observed as delayed genetic damage in the progeny of irradiated and unirradiated bystander cells. The expression of GI can be influenced by genotype, cell type and radiation quality. While several studies have demonstrated the induction of GI by high and low-linear energy transfer (LET) radiation, our work on human and mouse primary cell systems has shown LET-dependent differences in the induction and expression of GI. These differences might be attributed to differences in radiation track structure, dose rate, contribution of bystander cells and radiation dose. This paper reviews the role of radiation quality in the induction of GI and describe the possible mechanisms underlining the observed differences between radiation types on its induction. The experimental results presented suggest that dose might be the most significant factor in determining induction of GI after low-LET radiation.

Bystander Effect↗

Sequential development of multiple supernumerary teeth in the mandibular premolar region -- a radiographic case report.

This report presents a case of multiple supernumerary teeth developing in the mandibular premolar region in an Asian female patient. A series of radiographs taken over a 10-year period, demonstrate the sequential development of these teeth during the patient's early and middle teenage years. The importance of regular radiographic review and appropriate management for such cases is discussed.

Adolescent↗

Mutation frequency is reduced in the cerebellum of Big Blue mice overexpressing a human wild type SOD1 gene.

Amyotrophic lateral sclerosis (ALS) is a progressive paralytic disorder caused by motor neuron degeneration. A similar disease phenotype is observed in mice overexpressing a mutant human hSOD1 gene (G93A, 1Gurd(1)). Mice transgenic for lacI (Big Blue) and human mutant (1Gurd(1), Mut hSOD1) or wild type (2Gur, Wt hSOD1) SOD1 genes were used to examine spontaneous mutation, oxidative DNA damage, and neurodegeneration in vivo. The frequency and pattern of spontaneous mutation were determined for forebrain (90% glia), cerebellum (90% neurons) and thymus from 5-month-old male mice. Mutation frequency is not elevated significantly and mutation pattern is unaltered in Mut hSOD1 mice compared to control mice. Mutation frequency is reduced significantly in the cerebellum of Wt hSOD1 mice (1.6x10(-5); P=0.0093; Fisher's Exact Test) compared to mice without a human transgene (2.7x10(-5)). Mutation pattern is unaltered. This first report of an endogenous factor that can reduce in vivo, the frequency of spontaneous mutation suggests potential strategies for lowering mutagenesis related to aging, neurodegeneration, and carcinogenesis.

Amyotrophic Lateral Sclerosis↗

A longitudinal study of Giardia lamblia infection in north-east Brazilian children.

OBJECTIVE: To evaluate the epidemiology of Giardia lamblia infection, investigate factors which might be associated with clinical manifestations and recurrence, and examine the role of copathogens in disease course. METHODS: Prospective 4-year cohort study of children born in an urban slum in north-eastern Brazil. RESULTS: Of 157 children followed for > or = 3 months, 43 (27.4%) were infected with Giardia. The organism was identified in 8.8% of all stool specimens, and although found with similar frequency in non-diarrhoeal (7.4%) and diarrhoeal stools (9.7%), was more common in children with persistent (20.6%) than acute diarrhoea (7.6%, P=0.002). Recurrent or relapsing infections were common (46%). Children with symptomatic infections had significantly lower weight-for-age and height-for-age than asymptomatic children. Copathogens were not associated with disease course. CONCLUSION With its protean clinical manifestations, Giardia may be associated with substantial morbidity amongst children in Brazil.

Animals↗

Early childhood diarrhoea and helminthiases associate with long-term linear growth faltering.

BACKGROUND: Although the acute mortality from diarrhoeal diseases is well recognized, the potentially prolonged impact of early childhood diarrhoea on background growth and development is often overlooked. To examine the magnitude and duration of the association of early childhood enteric infections with growth faltering in later childhood, we investigated associations of early childhood diarrhoea (0-2 years) and intestinal helminthiases with nutritional status from age 2 to 7 years. METHODS: Twice-weekly diarrhoea surveillance and quarterly anthropometrics were followed from 1989 to 1998 in 119 children born into a Northeast Brazilian shantytown. RESULTS: Diarrhoea burdens at 0-2 years old were significantly associated with growth faltering at ages 2-7 years, even after controlling for nutritional status in infancy, helminthiases at 0-2 years old, family income, and maternal education by Pearson correlation, multivariate linear regression, and repeat measures analysis. The average 9.1 diarrhoeal episodes before age 2 years was associated with a 3.6 cm (95% CI : 0.6-6.6 cm) growth shortfall at age 7 years. Early childhood helminthiasis was also associated with linear growth faltering and a further 4.6 cm shortfall (95% CI : 0.8-7.9 cm) at age 7 years. CONCLUSIONS: Early childhood diarrhoea and helminthiases independently associate with substantial linear growth shortfalls that continue beyond age 6 years. Targeted interventions for their control may have profound and lasting growth benefits for children in similar settings.

Anthropometry↗

125 years of public health in the USA.

The past 125 years of public health in the United States are viewed from the perspective of the most significant public health areas of the 20th century as developed by the US Centers for Disease Control and Prevention. The long-term impacts and development of the areas include: immunizations, healthier mothers and babies, family planning, safer and healthier foods, fluoridation of drinking water, control of infectious diseases, decline in deaths from heart disease and stroke, recognition of tobacco as a health hazard, motor vehicle safety, and safer workplaces. The current and future of public health in the US is encapsulated in several developing areas, including: personal lifestyle modifications, politicalization of health, evolving knowledge base, knowledge transfer and globalization.

Centers for Disease Control and Prevention, U.S.↗

Lip cancer in South Australia, 1977-1996.

Lip cancer (140 ICD-9, C00 ICD-10) is a form of oral cancer occurring at the junction between the oral cavity and the skin. Lip cancer has a distinctive global epidemiology that is notably different from cancer occurring at other intraoral sites. This study reviews and analyses the epidemiological data for lip cancer from the South Australian Central Cancer Registry between 1977 and 1996. During this 20-year period, 2716 cases of lip cancer (2095 male, 621 female) and 35 deaths from this disease (23 males, 12 females) were reported. The average age of diagnosis was 58.3 years in males and 66.0 years in females. Very high age-standardised incidence rates (over 15.0 per 100000 per annum in males and 4.0 per 100000 per annum in females) were found, giving the South Australian population amongst the highest incidence of lip cancer in the world. Also of considerable concern was the finding that, contrary to global trends, these rates showed a significant increase over the 20-year period in both sexes. Possible reasons for these findings are discussed.

Adolescent↗

Persistent diarrhea signals a critical period of increased diarrhea burdens and nutritional shortfalls: a prospective cohort study among children in northeastern Brazil.

Persistent diarrhea (PD; duration >/=14 days) is a growing part of the global burden of diarrheal diseases. A 45-month prospective cohort study (with illness, nutritional, and microbiologic surveillance) was conducted in a shantytown in northeastern Brazil, to elucidate the epidemiology, nutritional impact, and causes of PD in early childhood (0-3 years of age). A nested case-control design was used to examine children's diarrhea burden and nutritional status before and after a first PD illness. PD illnesses accounted for 8% of episodes and 34% of days of diarrhea. First PD illnesses were preceded by a doubling of acute diarrhea burdens, were followed by further 2.6-3.5-fold increased diarrhea burdens for 18 months, and were associated with acute weight shortfalls. Exclusively breast-fed children had 8-fold lower diarrhea rates than did weaned children. PD-associated etiologic agents included Cryptosporidium, Giardia, enteric adenoviruses, and enterotoxigenic Escherichia coli. PD signals growth shortfalls and increased diarrhea burdens; children with PD merit extended support, and the illness warrants further study to elucidate its prevention, treatment, and impact.

Bacterial Infections↗

Changes over time in the epidemiology of diarrhea and malnutrition among children in an urban Brazilian shantytown, 1989 to 1996.

BACKGROUND: Endemic diarrhea and its associated malnutrition remain leading causes of childhood morbidity and mortality in developing countries. This study was undertaken to describe changes in the incidence of diarrhea and prevalence of malnutrition among children in an urban Brazilian shantytown from 1989 to 1996. A secondary purpose was to examine associations between malnutrition and increased incidence and duration of diarrhea. METHODS: From August 1989 through December 1996 a dynamic birth cohort of 315 children was followed for surveillance of diarrhea and nutrition. Study homes were visited twice or thrice weekly to assess the occurrence of diarrhea. Length and weight of the subjects were measured quarterly. Poisson regression was used to test for associations between prior nutritional status and subsequent diarrhea during a quarter. Multiple regression was used to test for an association between nutritional status and episode duration. RESULTS: Declines in both age-adjusted attack rates (6.0 episodes/child-year in study year 3 [1991] to 2.5 episodes per child-year in study year 8 [1996] and days of diarrhea per child-year (30.8 days/child-year in year 3 to 8.5 days/child-year in year 8) were correlated with yearly improvements in mean nutritional status (R2= 0.84, P < 0.05, for mean length-for-age with mean number of episodes/child-year [corrected]. Both length- and weight-for-age were significant predictors of diarrhea incidence, including persistent episodes (> or =14 d), but not duration. CONCLUSIONS: These results demonstrate marked changes over time in the diarrhea burden and nutritional status of children in this population and provide further evidence of a significant association between malnutrition and increased incidence of diarrhea.

Brazil↗

Retinol and retinol-binding protein: gut integrity and circulating immunoglobulins.

Vitamin A (retinol) is required to maintain immunity and epithelial turnover and is a key micronutrient needed for combating infection. Vitamin A actions on the immune system are diverse and cannot be accounted for by a single effect or mechanism. The actions of retinol in maintaining gut integrity in humans and immunoglobulin levels in mice was investigated. For 30 children, performance on the lactulose/mannitol test, a test commonly used to assess intestinal barrier function, was inversely correlated (P=.012) with serum retinol concentrations. Thus, children with lower serum retinol, and presumably poorer vitamin A nutritional status, are more likely to have impaired intestinal integrity. Knockout mice that have impairments in plasma retinol transport have circulating immunoglobulin levels that are half those observed in matched wild type mice. No differences were observed in B and T cell populations present in spleen, thymus, and bone marrow.

Animals↗

The epidemiology of mouth cancer: a review of global incidence.

Mouth cancer (143-145 ICD-9) is a major health problem in many parts of the world. While its incidence is relatively low in most western countries there are some important exceptions to this trend: on the Indian subcontinent and in other parts of Asia it remains one of the most common forms of cancer. This review article summarises the global incidence of mouth cancer using cancer maps. Data have been compiled from the latest edition of Cancer Incidence in Five Continents and recent studies from various locations around the world. Significant geographic variation is noted in the incidence of mouth cancer, with high rates reported for the Indian subcontinent and parts of Asia (male incidence rates in excess of 10 per 100,000 per annum). It is also noted that as with other forms of oral cancer, the majority of population-based data for mouth cancer comes from the Western world with a paucity of reliable data from the so-called developing countries. Mouth cancer remains a serious health problem in many parts of the world with many regions reporting increasing incidence rates particularly in males. Ongoing research into the aetiologic risk factors associated with this disease must remain a very high priority if the causes of mouth cancer are to be established and disease control protocols introduced widely.

Asia↗

The epidemiology of tongue cancer: a review of global incidence.

The tongue (141 ICD-9) is the most common intraoral site for cancer in most countries, however its global epidemiology shows significant geographic variation. This review paper summarises the global incidence of cancer of the tongue using cancer maps and references to recent studies from various locations. Tongue cancer remains a serious health problem in many countries including India (male incidence rates up to 6.5 per 100,000 per annum) and parts of Europe (male incidence rates in France up to 8.0 per 100,000 per annum). It is noted that as with other forms of oral cancer the majority of population-based data for tongue cancer comes from the Western world with a paucity of reliable data from the so-called developing countries. The tongue remains the most common intraoral site for oral cancer worldwide and in a number of countries it is a serious public health problem with significant morbidity and mortality. While the incidence of tongue cancer appears to be stable or falling in some regions of the world, in other areas it is rising, particularly among younger people.

Age Factors↗

Longitudinal study of Cryptosporidium infection in children in northeastern Brazil.

A prospective, 4-year cohort study of children born in an urban slum in northeastern Brazil was undertaken to elucidate the epidemiology of Cryptosporidium infection in an endemic setting, describe factors associated with Cryptosporidium-associated persistent diarrhea, and clarify the importance of copathogens in symptomatic cryptosporidiosis. A total of 1476 episodes of diarrhea, accounting for 7581 days of illness (5.25 episodes/child-year), were recorded: of these, 102 episodes (6.9%) were persistent. Cryptosporidium oocysts were identified in 7.4% of all stools, and they were found more frequently in children with persistent diarrhea (16.5%) than in those with acute (8.4%) or no (4.0%) diarrhea (P<.001). Low-birth-weight children and those living in densely crowded subdivisions were at greater risk for symptomatic infection. Disease course was highly variable and was not associated with the presence of copathogens. Recurrent Cryptosporidium infection and relapsing diarrhea associated with it were moderately common. In light of these data, the applicability of the current World Health Organization diarrheal definitions to Cryptosporidium-associated diarrheal episodes may need to be reconsidered.

Analysis of Variance↗

Association of early childhood diarrhea and cryptosporidiosis with impaired physical fitness and cognitive function four-seven years later in a poor urban community in northeast Brazil.

To determine potential, long-term deficits associated with early childhood diarrhea and parasitic infections, we studied the physical fitness (by the Harvard Step Test) and cognitive function (by standardized tests noted below) of 26 children who had complete surveillance for diarrhea in their first 2 years of life and who had continued surveillance until 6-9 years of age in a poor urban community (favela) in Fortaleza in northeast Brazil. Early childhood diarrhea at 0-2 years of age correlated with reduced fitness by the Harvard Step Test at 6-9 years of age (P = 0.03) even after controlling for anthropometric and muscle area effects, anemia, intestinal helminths, Giardia infections, respiratory illnesses, and socioeconomic variables. Early childhood cryptosporidial infections (6 with diarrhea and 3 without diarrhea) were also associated with reduced fitness at 6-9 year of age, even when controlling for current nutritional status. Early diarrhea did not correlate with activity scores (P = 0.697), and early diarrhea remained significantly correlated with fitness scores (P = 0.035) after controlling for activity scores. Early diarrhea burdens also correlated in pilot studies with impaired cognitive function using a McCarthy Draw-A-Design (P = 0.01; P = 0.017 when controlling for early helminth infections), Wechsler Intelligence Scale for Children coding tasks (P = 0.031), and backward digit span tests (P = 0.045). These findings document for the first time a potentially substantial impact of early childhood diarrhea and cryptosporidial infections on subsequent functional status. If confirmed, these findings have major implications for calculations of global disability adjusted life years and for the importance and potential cost effectiveness of targeted interventions for early childhood diarrhea.

Animals↗