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Biomedical subjects

J Mann

Publications and source records attributed to J Mann.

At least 163 records · Page 9Linked to original sources
PubMed1995

One month evaluation of the manually rotating "Bio-Bright" toothbrush for clinical safety and efficiency.

A clinical trial, based on the guidelines of the American Dental Association, was conducted to evaluate the efficacy and safety of Bio-Bright, a new manually rotating toothbrush. The brush was used by 28 adults and compared to a group of 26 adults who used an ADA-accepted toothbrush (Oral-B 35). Examinations were recorded for safety, plaque level, gingival inflammation and gingival bleeding at baseline, 15 days and one month. Analysis of the data revealed no statistically significant differences between the two groups at any of the measurement periods. When calculating the cumulative longitudinal effect on plaque increase or decrease, a consistent and statically significant advantage was revealed for the Bio-Bright group, as compared to the control. No significant differences were demonstrated when comparing safety, gingival, and bleeding indices between the two groups.

Adult↗
PubMed1994

Risk of death from cancer and ischaemic heart disease in meat and non-meat eaters.

OBJECTIVE: To investigate the health consequences of a vegetarian diet by examining the 12 year mortality of non-meat eaters and meat eating controls. DESIGN: Prospective observational study in which members of the non-meat eating cohort were asked to nominate friends or relatives as controls. SETTING: United Kingdom. SUBJECTS: 6115 non-meat eaters identified through the Vegetarian Society of the United Kingdom and the news media (mean (SD) age 38.7 (16.8) years) and 5015 controls who were meat eaters (39.3 (15.4) years). MAIN OUTCOME MEASURES: Standardised mortality ratios for cancer, ischaemic heart disease, and total mortality in the two cohorts and death rate ratio in the non-meat eaters compared with meat eaters after adjustment for potentially confounding variables. RESULTS: Standardised mortality ratios (taking the value among the general population as 100) for ischaemic heart disease were 51 (95% confidence interval 38 to 66) for meat eaters and 28 (20 to 38) for non-meat eaters (P < 0.01). Values for all cancers were 80 (64 to 98) and 50 (39 to 62) for meat eaters and non-meat eaters respectively. After adjustment for the effects of smoking, body mass index, and socioeconomic status death rate ratios in non-meat eaters compared with meat eaters were 0.72 (0.47 to 1.10) for ischaemic heart disease and 0.61 (0.44 to 0.84) for all cancers. CONCLUSIONS: The reduced mortality from cancer among those not eating meat is not explained by lifestyle related risk factors, which have a low prevalence among vegetarians. No firm conclusion can be made about deaths from ischaemic heart disease. These data do not justify advice to exclude meat from the diet since there are several attributes of a vegetarian diet apart from not eating meat which might reduce the risk.

Adult↗
PubMed1994

Fatty acid composition of erythrocytes and plasma triglyceride and cardiovascular risk in Asian diabetic patients.

The excess of coronary heart disease in Indian Asians compared with Europeans is unexplained by conventional risk factors, although the high prevalence of diabetes may play a part. To explore the contribution of diet we compared the fatty acid composition of erythrocyte membrane phospholipid and plasma triglyceride in 36 Gujarati Asians and 24 Europeans with non-insulin-dependent diabetes. Erythrocytes from Asian subjects contained higher proportions of linoleic, dihomogammalinolenic, and arachidonic acids, and lower proportions of oleic and n-3 series fatty acids; triglycerides contained higher linoleic and lower oleic acid levels. For example, mean percentage (SE) of oleic acid (18:1n-9) in erythrocytes was 16.7 (0.2) in Asians and 20.5 (0.6) in Europeans (p = 0.0001), and total n-6:n-3 ratio was, respectively, 12.8 (0.7) and 6.7 (0.7) (p = 0.0001). A high dietary intake of linoleic acid may not be cardioprotective unless balanced by significant intakes of oleic and n-3 series fatty acids, at least in diabetic Indian Asians. By itself, the conventional recommendation to substitute polyunsaturated for saturated fat in the diet may be inadequate to reduce thrombogenesis, and the overall balance of fatty acids, including monounsaturates, should be considered.

Arachidonic Acids↗
PubMed1994

Metabolic effects of alterations in meal frequency in hypercholesterolaemic individuals.

It has been suggested that the metabolic consequences of a given diet may depend in part on the frequency with which meals are eaten. To investigate the effects of meal frequency on plasma lipid metabolism, 16 free-living hypercholesterolaemic men and women consumed their usual diet as 3 or 9 meals/day in random order for 4 weeks. Dietary macronutrient intake and body weight remained similar on the 2 regimens. Fasting plasma lipids were measured after 2, 3 and 4 weeks on each regimen and there were no significant differences in the fasting concentrations of plasma total, LDL, and HDL cholesterol, triglycerides, apolipoprotein A-I and B and the ratio of total: LDL and LDL:HDL cholesterol (HDL-C) on the two diets. The mean (+/- S.D.) fasting total cholesterol was 6.73 +/- 0.74 and 6.81 +/- 0.88 mmol/l on 3 and 9 meals/day, respectively and LDL-C was 4.77 +/- 0.66 and 4.87 +/- 0.78 mmol/l, respectively. There was also no significant variation in the response of plasma triglycerides or serum insulin to a high fat meal following a 3 week adaptation to regimens of 3 and 9 meals/day. Finally the 24 h urinary output of C-peptide was similar on each diet. The consumption of isoenergetic diets as 3 and 9 meals/day did not influence fasting plasma lipid levels, C-peptide excretion or the plasma triglyceride response to a high fat meal of a group of free living hypercholesterolaemic subjects.

Adult↗
PubMed1994

Clinical anatomy of the atrioventricular junctions.

OBJECTIVES: This study reevaluated the anatomy of the areas anterior and posterior to the atrioventricular (AV) septal structures, previously said to represent anterior and posterior septal areas. BACKGROUND: In descriptions of the locations of accessory AV pathways within the AV junctions, four regions have been recognized: the left and right free walls and the anterior and posterior septums. On the basis of known facts concerning cardiac structure, it is questionable whether these so-called septums are truly septal. METHODS: Ten human hearts were dissected to elucidate the clinical anatomy of these purportedly septal regions, together with the overall arrangement of the AV junctions. RESULTS: The true septal components of the AV junctions are the muscular and membranous AV septal areas. These separate the cavity of the right atrium from that of the left ventricle. The region previously designated as the anterior septum is part of the right parietal junction. It is contiguous with the membranous part of the septum but extends anteriorly and laterally from the septum as part of the supraventricular crest of the right ventricle ("crista supraventricularis"). In the region posterior to and beneath the mouth of the coronary sinus, only the most anterior extent, in continuity with the central fibrous body, is part of the muscular AV septum. The posterior extent of this area roofs over the diverging right and left ventricular walls and is filled in with fibroareolar tissue of the AV groove. CONCLUSIONS: The larger part of the regions anterior and posterior to the true AV septal areas are not septal but are parts of the parietal AV junctions. An understanding of these anatomic relations is essential for those wishing to modify conduction across the AV junctions.

Atrioventricular Node↗
PubMed1994

Independent regulatory elements in the nestin gene direct transgene expression to neural stem cells or muscle precursors.

Changes in intermediate filament gene expression occur at key steps in the differentiation of cell types in the mammalian CNS. Neuroepithelial stem cells express the intermediate filament protein nestin and down-regulate it sharply at the transition from proliferating stem cell to postmitotic neuron. Nestin is also expressed in muscle precursors but not in mature muscle cells. We show here that in transgenic mice, independent cell type-specific elements in the first and second introns of the nestin gene consistently direct reporter gene expression to developing muscle and neural precursors, respectively. The second intron contains an enhancer that functions in CNS stem cells, suggesting that there may be a single transcriptional mechanism regulating the CNS stem cell state. This enhancer is much less active in the PNS. The identification of these elements facilitates analysis of mechanisms controlling the switch in gene expression that occurs when muscle and brain precursors terminally differentiate.

Animals↗
PubMed1994

Evaluation of some 4-fluoro- and 4-cyano derivatives of delta 4,3-ketosteroids as inhibitors of testosterone 5 alpha-reductase.

Some 4-fluorinated analogues of 3-oxo-delta 4 steroids and 4-cyano derivatives of progesterone and androstenedione were evaluated as inhibitors of steroid 5 alpha-reductase activity. Inhibitors of this enzyme may be useful in treating prostatic cancer. 4-Fluoroandrostenedione was a modest inhibitor of the rat enzyme (IC50 = 4.08 microM), while 4-cyanoprogesterone was a potent inhibitor of both the rat and human enzymes (IC50 values = 0.045 microM and 0.050 microM respectively). These two steroids were tested in vivo for activity against androgen sensitive organs in WHT mice. 4-Fluoroandrostenedione caused increases in organ weights, suggesting it is an androgen agonist, while the 4-cyano compound displayed modest androgen ablation. Therefore substitutions at the 4-position may produce compounds of therapeutic use in treating prostate cancer.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1994

[Ischemic nephropathy].

Ischemic nephropathy encompasses renal insufficiency due to 3 different diseases, namely renal artery stenosis, so-called benign nephrosclerosis, and renal cholesterol embolism. All 3 disease entities may lead to a progressive loss of renal excretory function. If a patient presents with renal failure of unknown origin, renal artery stenosis should be looked for by color-coded duplex scanning or arteriography. The clinical presentation of benign nephrosclerosis in caucasians has no typical clues. Usually, a renal biopsy identifies this renal disorder in a patient with long-standing hypertension, moderate proteinuria and renal insufficiency. Cholesterol embolism typically affects several arterial trees, and is induced by arteriography in patients with arteriosclerosis of the aorta. The best treatment for ischemic nephropathy due to renal artery stenosis [conservative, angioplasty, surgery] is unknown because appropriately controlled trials are lacking. Invasive therapy should be considered in patients with bilateral renal artery stenosis or stenosis of a single functioning kidney, particularly if the affected kidney is not contracted. Arguments in favor of invasive therapy include the progressive nature of renal artery stenosis and the poor outcome of dialysis patients with this diagnosis as underlying renal disease.

Aortography↗
PubMed1994

Prevalence of dental caries among Ethiopian emmigrants.

Studies have documented the prevalence of caries in developing countries. The current study adds to this body of knowledge. Of the total Ethiopian Jewish population who emmigrated to Israel in 1991, a sample of over 800 individuals was randomly selected representing all age groups. DMF-T and DMF-S scores were recorded, as well as percentages of caries free individuals. Results indicated that almost no fillings or crowns had been provided to the study population. The Missing 'M' component was low as was the Decay 'D' component, although this increased with increasing age, ranging from 0.33 D-T at the 0-12 age group to 2.46 at the 51+ age group. In the permanent dentition 88.4 per cent of those 0-12 years of age were caries free and 74.5 per cent were caries free in both the primary and permanent dentition. Almost 59 per cent of the 13-20 years olds were caries free and 32.8 per cent of those 21-50 years old. Only 16.7 per cent were caries free at age 51+ years old. The data indicate a relatively low prevalence of both coronal and root caries, and an effort has to be made to keep these figures low for years to come mainly by diet and dental health education.

Adolescent↗
PubMed1994

Nutrient intake and haematological status of vegetarians and age-sex matched omnivores.

OBJECTIVE: The study was designed to investigate the nutritional intake and haematological status of adult vegetarians. DESIGN: Cross-sectional comparison of vegetarians and age/sex-matched omnivores. SETTING: Free-living community subjects. SUBJECTS: Fifty vegetarians were recruited by local advertisement. Each vegetarian selected their own age/sex-matched 'friend' control. OUTCOME MEASURES: Each subject completed a 12 day dietary record. Haemoglobin, red cell indices, and serum ferritin, B12 and folate were measured. RESULTS: Protein, saturated fat and vitamin D intake were significantly lower in the vegetarians, particularly in the vegans. Dietary fibre was higher in the vegetarians, and intake of calcium and zinc was similar. Mean (SD) iron intake in the vegetarians and vegans of 16.8 (4.8) mg/day was significantly greater than that of the omnivores: 14.6 (4.3) mg/day (P = 0.02). All the iron consumed by the vegetarians was non-haem; for the omnivores 10% was haem iron. Serum ferritin concentrations were significantly lower in male vegetarians than omnivores; mean (SD): 36.6 (36.0) and 105.4 (78.7) ng/ml, respectively, P < 0.01; and significantly more had values below 12 ng/ml (P < 0.001), despite having higher iron intakes which exceeded the Recommended Nutrient Intake (RNI). Female vegetarians also had lower ferritin concentrations than omnivores; mean (SD) 13.6 (7.5) compared to 33.6 (54.3) ng/ml, P < 0.01, but similar numbers of women had values below 12 ng/ml (42% and 39%). The vegans all had B12 intakes below the RNI; and 35% of the long-term vegetarians and vegans had serum vitamin B12 concentrations below the reference range. CONCLUSION: Although the vegetarians had diets nearer to the recommended diet with a lower fat and salt content, a significant number need advice to improve their haematological status. Recommended intakes of iron may also need to be higher for vegetarians, particularly men.

Adult↗