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Biomedical subjects

J Mann

Publications and source records attributed to J Mann.

At least 253 records · Page 14Linked to original sources
PubMed1989

Assessment of the DMF-S index with the use of bitewing radiographs.

A study population of students (ages 14 to 18 years) was examined radiographically (bitewings) and by clinical DMF-S evaluations. Results revealed a clinically detected total DMF-S of 8.31 with a D-S of 4.86. Decay clinically detected on premolars and molars alone was 4.38, whereas an additional 4.88 surfaces were radiographically detected as being carious. It was determined that a multiplying factor of 1.59 should be used in the present study population to better assess the actual total DMF-S figure. Validity of the correction factor was tested and validated.

Adolescent↗
PubMed1989

Serum lipid response to dietary cholesterol in subjects fed a low-fat, high-fiber diet.

To determine whether hyperresponse to dietary cholesterol occurs in individuals consuming a low-fat diet, a study was performed on 58 subjects whose plasma cholesterol had changed by greater than or equal to 5% when intakes of two and seven eggs per week were compared in a previous study. Here, the effect of eating nine, zero, and nine eggs per week was studied over 3 consecutive months. Plasma total, LDL, and HDL cholesterol did not differ significantly. There was no correlation between individuals' lipoprotein changes in this and the previous study. Consistent hyperresponse to moderate cholesterol intake is not apparent in people eating a low-fat, high-fiber diet. Reduction in dietary cholesterol below 400 mg/d produces no further substantial cholesterol lowering.

Adult↗
PubMed1989

Relationship of body mass index, weight and height to plasma lipid levels in people with different diets in Britain.

Blood samples and self-reported heights and weights have been collected from 114 vegans, 1550 vegetarians, 415 fish eaters who did not eat meat, and 1198 meat eaters. We have previously reported that mean total and LDL cholesterol were lower in the vegetarians and fish eaters than in the meat eaters, while the mean levels in vegans were lower still. We have examined the possibility that this relationship could be explained by differences in the mean body mass index of the four groups. While there was a small positive relationship between body mass index and plasma lipid levels this did not explain the previously reported difference between diet groups. After adjusting for the effect of body mass index there remained a small negative association between height and plasma lipid levels, which has not previously been reported. Height is known to be influenced by childhood ill health and has also been shown to be related to social class, and it may be that the relationship between plasma lipid levels and height can be explained by these factors.

Body Height↗
PubMed1989

Enhancement of leukotriene C4 release from primate airway macrophages by cellular interactions.

1. Cells were obtained from the lungs of Macaque monkeys by bronchoalveolar lavage in order to study the role of cellular interactions in the release of leukotriene C4 (LTC4). 2. In normal monkeys, macrophages were the most abundant cell type recovered, whereas in monkeys sensitized with Ascaris suum there was an increase in the numbers of eosinophils and mast cells recovered. 3. Challenge of cells from both groups of animals with an optimal concentration of opsonized zymosan (OPZ) resulted in the time-dependent release of LTC4 from macrophages. However, release was significantly greater in cells obtained from sensitized donors compared to normal donors. 4. Density-gradient centrifugation of cells lavaged from sensitized donors was used to prepare fractions containing both eosinophils and mast cells. Addition of these cells to macrophage populations obtained from non-sensitized donors caused a significant enhancement of OPZ-induced LTC4 release. In the absence of macrophages no significant release of LTC4 was detected from eosinophil/mast cell-containing fractions stimulated with OPZ, despite the fact that the zymosan had been phagocytosed by the eosinophils. 5. There was a significant correlation between the percentage enhancement of LTC4 release and the number of eosinophils added. However, there was not a significant correlation with the number of mast cells added. 6. These results suggest that a cellular interaction between macrophages and eosinophils may be important in the regulation of mediator synthesis and release. The precise mechanism of this effect remains to be elucidated.

Animals↗
PubMed1989

Prevalence and distribution of caries in a Jerusalem adolescent population by age, sex, and family income.

Four hundred and fourteen high school students aged 12-17 were examined clinically using the DMFS index and bitewing radiographs. Analyses by age, sex, economic status, and types of teeth and tooth surfaces were performed and results were compared with other international studies. Only 7.5 percent of the study population had a zero DMFS score. Females had a significantly higher DMFS score than males (13.21 vs 9.59). Caries experience increased with age and a general trend of increasing DMFS was observed with increasing levels of income. Socioeconomic status (SES) was related directly to DMFS in Israel, in contrast to an inverse relationship observed in most other western countries. First molars were most susceptible to caries attack and accounted for 41.2 percent of the total DMFS. Almost 50 percent of all affected surfaces were occlusal and 29.4 percent were proximal. Caries prevalence in general and proximal caries in particular were found to be much higher in the study population than corresponding figures in other industrialized countries. A significant decrease in caries prevalence could be expected in Israel in the next decade if primary preventive measures are implemented immediately.

Adolescent↗
PubMed1989

Hyperparathyroidism and abnormal calcitriol metabolism in the spontaneously hypertensive rat.

Abnormalities of calcium metabolism and of its two principal regulating hormones, parathyroid hormone and 1,25-dihydroxyvitamin D3 (calcitriol), have been reported in the spontaneously hypertensive rat (SHR). Reports of abnormal calcitriol metabolism in the SHR by several groups have not provided measurements of tissue calcitriol receptors. Similarly, few data are available as to the parathyroid status of the SHR. In the present study, circulating calcitriol levels and intestinal and parathyroid gland calcitriol receptor status were determined in male SHR and in Wistar-Kyoto (WKY) rats. Parathyroid status was investigated by determination of parathyroid gland mass together with tissue micromorphometry and by quantitative histology of bone as a measure of the biological action of parathyroid hormone. Circulating calcitriol levels were reduced in the 11-week-old SHR compared with the WKY rat (165 +/- 23 vs. 194 +/- 28 pmol/l, p less than 0.01, mean +/- SD). Calcitriol-free ratio was diminished and maximal specific binding capacity for calcitriol was increased in the SHR in parathyroid tissue (172 +/- 4.9 vs. 123 +/- 6.6 fmol/mg protein, p less than 0.01) and in intestinal mucosa with no change of receptor affinity. Plasma ionized calcium (1.29 +/- 0.05 vs. 1.45 +/- 0.35 mmol/l, p less than 0.05) and phosphate (1.5 +/- 0.26 vs. 2.4 +/- 0.03 mmol/l, p less than 0.05) were significantly lower in the SHR. Parathyroid gland mass was increased in the SHR (59 +/- 12 vs. 17 +/- 7 micrograms/100 g body wt, p less than 0.001) as a result of hyperplasia and not hypertrophy. Higher osteoclast numbers were observed in SHR bone (27.6 +/- 0.79 vs. 23.9 +/- 0.66 osteoclasts/mm2, p less than 0.01), suggesting increased parathyroid hormone activity. In summary, in the 11-week-old SHR we observed reduced circulating calcitriol levels together with increased tissue calcitriol receptor numbers, increased parathyroid gland mass, and histological evidence of hyperparathyroidism. It is possible that these abnormalities influence the development of hypertension in the SHR.

Animals↗
PubMed1989

Uncompensated emergency care in hospital markets in Los Angeles County.

A survey of hospital emergency rooms in Los Angeles County was conducted in March 1987. Analysis of the distribution of uninsured emergency care patients revealed that private hospitals play a significant frontline role in terms of entry into the hospital system for patients who are unable to pay--almost one-half of such patients were treated in the emergency rooms of private hospitals. Hospitals serving markets in which a higher proportion of residents had incomes below the poverty level provided a greater share of uncompensated emergency room services.

Costs and Cost Analysis↗
PubMed1989

The effect of fluoride drop administration on dental caries increment--a longitudinal study.

The effect of fluoride drop supplementation was investigated in a longitudinal study initiated in 1980. The def-t and DMF-T indices were used to estimate the incremental caries rate of the deciduous and first molars of 211 children aged 7-8 and 9.5-10.5 years. No statistically significant differences between the experimental and control def-t and DMF-T scores were found after 3 years. The incremental caries rate of the deciduous dentition of the experimental group was found to be significantly lower than that of the control group (def-t = 0.61 and 1.07 respectively), whereas the difference in the caries increments of the first molars was not significant (DMF-T = 1.62 in both groups). It is estimated that the efficacy was due to the long-term cariostatic effect of the topically acting fluoride on the erupting primary dentition, whereas the permanent dentition (first molars) had already completed calcification of the crown, but had not erupted at initiation of the study. It was estimated that the most effective cariostatic benefits would be apparent in the late erupting teeth of this study group.

Child↗
PubMed1989

Reaction patterns of the myocardial interstitium in different models of cardiac hypertrophy--stereological investigations.

Several experimental models of cardiac hypertrophy were investigated in rats: 1. mild hypertrophy induced by physical exercise (18 weeks), 2. mild hypertrophy induced by renovascular hypertension (24 weeks), 3. moderate hypertrophy induced by renovascular hypertension in diabetic and non-diabetic animals (8 weeks), 4. moderate hypertrophy induced by renovascular hypertension in diabetic and non-diabetic animals (12 weeks), 5. moderate hypertrophy induced by thyroxin application (4 weeks), 6. mild hypertrophy in chronic uremia (5/6 nephrectomy, 3 weeks). It is concluded from quantitative stereological parameters of the left ventricular papillary muscles that 1. in hypertrophic hearts myocardial blood flow and oxygen consumption, respectively, rather than the size of muscle fibres determine the capillary supply of the myocardium, 2. interstitial fibrosis occurs in hypertrophy induced by chronic pressure overload and depends on degree and duration of hypertension, 3. the extent of interstitial fibrosis in hypertension is magnified by diabetes mellitus, and 4. the interstitial fibrosis which occurs in chronic uremia is not caused by hypertension.

Animals↗
PubMed1989

AIDS.

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Global surveillance and forecasting of AIDS.

The short-term forecasting of future AIDS cases has been attempted by statistical extrapolations of the observed curve of reported AIDS cases. In areas where such reporting is very incomplete or has only recently started, extrapolation is not possible and an epidemiologically-based forecasting model has been developed to estimate the annual number of AIDS cases which may have occurred and to project the annual number and distribution of AIDS cases for up to ten years. This model, which relies on the current understanding of the epidemiology and natural history of HIV infections and on the available HIV serologic survey data, is used to provide estimates and short-term projections of AIDS cases for the USA, Europe, Africa and the world. Because of the very long (mean of 8-9 years) incubation period between HIV infection and the development of AIDS, new cases over the next five years will be mostly derived from persons who became infected with HIV in or before 1987. WHO has estimated that 5-10 million persons worldwide were infected with HIV in 1987. Based on the lower estimate of 5 million, the cumulative number of AIDS cases which can be projected for the end of 1991 is over one million, and for the mid-to-late 1990s could reach 2 to 3 million. HIV/AIDS will therefore be an increasing public health problem throughout the world. Health care systems everywhere will have to be strengthened to respond to this large toll of disease and death due to AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Histological inhomogeneity of colorectal adenocarcinomas.

The histological inhomogeneity of colorectal adenocarcinomas has hardly been systematically investigated up to now. Currently, however, this awareness is gaining in importance, e.g. within the framework of grading measures, for analysis of immunohistochemical results or for interpretation of flowcytometric data. Thus, 100 colon carcinomas each were semiquantitatively investigated on four different sites in terms of either homogeneous or inhomogeneous expression of histological, cytological and immunohistochemical (CEA, UEA I) criteria. Although all carcinomas contained tubular structures, there was no intraindividual uniformity but considerable inhomogeneity on the part of histological as well as cytological features. Quantitative and qualitative positivity of CEA and UEA I too, varied markedly. Our results lead to the conclusion that the phenotypic inhomogeneity of colorectal carcinoma is at least partially attributable to genetic tumor cell instability. In spite of this, there might be a trend to intra-individual localisation-related tumor cell differentiation, because several parameters showed significant differences between luminal and deep carcinoma regions.

Adenocarcinoma↗
PubMed1988

[The renin-angiotensin system in diabetic patients].

We review available data on the activity of the renin-angiotensin system (RAS), responsiveness to angiotensin II (ANG II), ANG II receptor number, and effects of inhibition of the RAS by angiotensin I converting enzyme (ACE) inhibitors in patients with diabetes mellitus. Most authors, including ourselves, observed a normal or enhanced activity of the RAS in metabolically stable diabetics. Increased but also reduced activity of the RAS was described in nephropathic diabetes. This is in contrast to the common suggestion that the RAS of diabetics is generally suppressed and functionally inactive. The last assumption was mainly based on the finding of reduced ANG II receptor numbers in anorectic, severely hyperglycemic rats. These findings could not be reproduced in man, and a higher ANG II receptor concentration on platelets of diabetics goes in parallel with the frequent finding of an enhanced pressor response to infused ANG II in diabetes. This increased responsiveness is most probably of functional importance since the RAS is not suppressed - as one would expect - in the face of a supranormal body sodium content. A number of data also indicate that renal resistance vessels display increased responsiveness to ANG II in diabetics. This may be a reason for hyperfiltration. This notion is further supported by the reduction of albuminuria which is usually observed following inhibition of the RAS with ACE inhibitors, and which may be an index of reduction of glomerular capillary pressure in human diabetes.

Diabetes Mellitus, Type 1↗
PubMed1988

XX/XY chimerism encountered during prenatal diagnosis.

46,XX/46,XY chimerism has previously been reported in patients with abnormal sexual development, and rarely in otherwise normal individuals. We report the first postnatally documented prenatal diagnosis of whole-body 46,XX/46,XY chimerism in humans, discovered by maternal age amniocentesis. The normal male phenotype in this child creates a dilemma in prenatal counselling, since genotypic male/female chimerism cannot be assumed to imply an abnormal sexual phenotype.

Adult↗
PubMed1988

Characterization of genetic markers in the 3' end of the apo B gene and their use in family and population studies.

The 3' end of the apo B gene is highly polymorphic. Two point mutations in the coding sequence of the gene create EcoRI (E+, E-) and XbaI (X+, X-) RFLPs. The two loci are in random association and the frequency of the four haplotypes, E+X+, E+X-, E-X+ and E-X- in the normolipidaemic population are 0.68, 0.30, 0.02 and 0.00, respectively. Although the polymorphic nucleotide underlying the EcoRI RFLP creates an amino acid substitution in the apo B protein (Glu----Lys) in a region close to a putative LDL-receptor recognition site(s), we find no statistically significant difference in the frequency of the apo BGlu and apo BLys alleles in hyperlipidaemic patients (familial hypercholesterolaemia, type IIA with no tendon xanthomas, IIB and probably IV) and the normolipidaemic population. In contrast, we confirm previous findings, that the X+ allele is in linkage disequilibrium with a genetic locus that predisposes to the development of higher fasting plasma triglyceride levels than the X- allele. We have characterized a highly polymorphic region immediately 3' to the apo B gene. At least 5 alleles of this locus exist in the population and our family studies show it should be an extremely informative locus to use in studies where polymorphic or mutant apo B alleles are suspected to underly certain forms of familial hyperlipidaemia. DNA sequence analysis of this highly polymorphic locus shows that the variation is entirely attributable to the number of times the simple repeating sequence 5'-TTTATAATTAAAATATTTATAATTAAATAT-3' is present.

Adult↗