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Biomedical subjects

J Schott

Publications and source records attributed to J Schott.

At least 37 records · Page 2Linked to original sources
PubMed1995

Nutrition and allorejection impact of lipids.

Polyene n-3 and n-6 fatty acids are claimed to have immunomodulating properties. The impact of nutritional variations on transplant rejection was therefore studied in the heterotopic rat heart allotransplant model with particular focus on lipids. Twenty per cent fat emulsions with differing n-3/n-6 fatty acid ratios were continuously infused (9 g fat per kg bodyweight per day; n = 10 in each group) after transplantation until rejection: safflower oil (n-3/n-6 = 1/370), fish oil (7.6/1), soybean oil (1/6.5) and a 1:1 mixture of safflower and fish oil (1/2.1; oil control group). Graft survival time, subpopulations of infiltrating and circulating immunocompetent cells and interleukin-6 release by circulating mononuclear cells were analysed. In the safflower oil, fish oil and soybean oil groups graft survival was prolonged to 13.3, 12.3 and 10.4 days vs. 6.7 days in the oil control group and 7.8 days in the saline control group (p < 0.01). In the two groups with the highest prolongation of graft survival the number of infiltrating cells was reduced by up to 50% and the peripheral blood mononuclear cell interleukin-6 release by up to 45%. Beyond that, circulating T-cells were reduced in the fish oil group. The n-3/n-6 fatty acid ratio determines the immunomodulating effect of lipids. Both n-6 and n-3 fatty acids, if applied as the main fatty acid source, exert immunosuppressive effects by diminished infiltration, mobilization and cytokine release by immunocompetent cells. A n-3/n-6 fatty acid ratio of 1/2 proved to be immunologically neutral. The recipient's disposition to reject an allotransplant is influenced by the fatty acid composition of exogenously supplied lipids.

Animal Nutritional Physiological Phenomena↗
PubMed1995

Contractile properties of the quadriceps muscle in growth hormone-deficient hypopituitary adults.

1. Growth hormone-deficient hypopituitary adults often complain of weakness and fatigue. The cause of the fatigue is unknown but could be an increased proportion of fast, fatiguable, type 2 fibres in the muscle. The aim of this study was to examine the contractile properties of the quadriceps muscle in a group of these patients compared with healthy controls. Changes in these properties were also examined in a small subset of the patients following growth hormone replacement. 2. Isometric strength, half-relaxation time from a twitch (t1/2) and the force-frequency relationship were measured using electrically evoked contractions in 14 growth hormone-deficient patients and 14 age- and sex-matched controls. Six patients were restudied following 6-24 month's replacement therapy with growth hormone (daily dose 0.04 +/- 0.01 i.u./kg). 3. The growth hormone-deficient patients had a significantly lower t1/2 than the controls (46.1 +/- 6.1 ms versus 56.1 +/- 10.5 ms respectively; P = 0.0072; mean +/- SD). The 10/100% ratio was also significantly lower in growth-hormone-deficient patients (38.6 +/- 9.9% versus 52.3 +/- 8.0%; P = 0.0005), as was muscle strength (349 +/- 99 N versus 493 +/- 215 N; P = 0.036). Following growth hormone replacement, muscle strength increased significantly (P < 0.05). The 10/100% ratio also increased towards control values, but this change was not significant. 4. These results demonstrate that the relaxation times of the quadriceps are significantly shorter and that the force-frequency relationship shifted to the right in growth hormone-deficient patients, which is consistent with a greater proportion of type 2 fibres within the muscles.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

[Frequency analysis for achieving health goals--I: Standardization].

The formal mathematical steps of direct and indirect standardisation are deduced and it is pointed out that standardisation is an analytical concept for processing data within the framework of structurised populations to enable correct interpretation of these data in a manner modified according to specific problems. In particular, this concept is not confined to transforming age-structured mortality data of a population to the age distribution of the members of a larger population by means of a rule of three. Standardisation is in fact a model of the macrolevel (population). It makes no demands on the modalities of structuring. The structure selected as standard is arbitrarily set. With time series, standardisation usually modifies only the levels of the figures and not the frequencies. The results of standardisation are in every case valid only if the standard is also stated. A rule of thumb is: In retrospective analysis it is meaningful to standardise on the structure at the beginning or end of the time series; in extrapolations standardisation should be performed on the last structure that had been determined, whereas for comparisons a median structure should be standardised. The standardisation approach can be used in case of weighted arithmetic, geometric or harmonic means. Before effecting standardisation, the type of connection between the employed data should be examined. The examples of concepts of direct standardisation refer to cardiovascular and accident mortality in West Berlin from 1963 to 1991, whereas those of indirect standardisation are based on the accident mortality in West Berlin in 1987 structured according to city districts.

Accidents↗
PubMed1995

[Frequency analysis for achieving health goals--II: Analysis of mortality tables for cause of death, expected mortality].

The article gives algorithms to calculate mean ages at death for specific causes, based on life table models. Parameters of interest are death due to a specific cause, dying after the "elimination" of the specific cause, or the transition into a "new" structure of mortality when a specific cause of death vanishes. The setbacks of widely used calculations are discussed in this context. These different approaches are demonstrated by means of data pertaining to accident and cardiovascular mortality of the male population of Berlin (West). The estimated impact on life expectancy varies according to both the mathematical model and the specific cause of death: differences are negligible in mortality due to accidents, whereas the results differ considerably in cardiovascular causes of death. The algorithm suggested allows to constrain the calculations to specific age groups. Topics such as "avoidable death" and "health objectives" have to be aware of these different methods.

Accidents, Traffic↗
PubMed1995

[Immunosuppressive effect of parenteral fat emulsions in defined immunostimulation].

BACKGROUND: In the heterotopic rat heart allotransplant model we have previously shown that intravenous fat emulsions are to a various extent immunosuppressive or immunoneutral, dependent on their n-3/n-6 fatty acid ratio. Safflower oil (n-3: n-6 = 1:370), fish oil (7.6:1) and soybean oil (1:6.5) prolonged the transplant survival time to 13.3, 12.3 and 10.4 days compared to 6.7 days (oil control group; 1.2.1) and 7.8 days (saline control group) (p < 0.01), respectively. This study presents a correlation of graft survival to immunohistological, cell biological and biochemical parameters. MATERIALS AND METHODS: 20% emulsions of safflower oil, fish oil, soybean oil and a 1:1 mixture of safflower and fish oil (oil control group) were continuously infused (9 g fat/kg body weight/day; n = 10 each group) after transplantation. Subpopulations of infiltrating and circulating immunocompetent cells and leukotriene B4 and B5 release of circulating mononuclear cells were analyzed (on the 4th postoperative day). RESULTS: In the 2 groups with the highest prolongation of graft survival the number of infiltrating cells was reduced by up to 40% and the peripheral blood mononuclear cell interleukin-6 release by up to 45%. Beyond that, circulating T cells were reduced in the fish oil group. Leukotriene B4 was released in all groups to the same extent, leukotriene B5 exclusively in the fish oil group. CONCLUSIONS: Intravenous fat emulsions show a varying immunomodulatory effect in dependence of the n-3/n-6 fatty acid ratio. Both n-6 and n-3 fatty acids, if applied as main fatty acid source, exert immunosuppressive effects by a diminished infiltration and mobilisation of immunocompetent cells. Soybean oil with a more balanced n-3/n-6 fatty acid ratio than safflower oil is significantly less immunosuppressive than safflower oil, and fat emulsions with a n-3/n-6 fatty acid ratio of 1:2 are immunologically neutral.

Animals↗
PubMed1994

[The significance of AIDS for mortality in Berlin (West)].

Following a long-term decline, death rates due to infectious diseases in West-Berlin men have dramatically increased since 1983. The Berlin mortality statistics introduced AIDS as a specific cause of death only in 1989. However, opportunistic infections, a negligible quantity until 1983, and pointing to AIDS as the underlying cause, show a steep increase in the mid and late eighties. In terms of Potential Years of Life Lost, AIDS-related mortality amounts to 8 percent of total mortality in West-Berlin men in 1989/1990.

AIDS-Related Opportunistic Infections↗
PubMed1989

[The role of migration in assessing age-specific event probabilities exemplified by the probability of death].

Estimating probabilities of age-specific events both in demography and in epidemiology (force of mortality, force of morbidity) will contain additional errors if the frequency of the respective events is influenced by net migration and if migration is not taken into consideration when estimating these events. The terms used in including migration into estimating the respective rates are refined terms. The influence of migration on age-specific events is demonstrated by age-specific mortality and the life expectancy computed on the basis of age-specific mortality rates for the GDR in 1984. The results demonstrate that the life expectancy of the population of Berlin will be underestimated by 0.28 years if migration processes are not taken into consideration.

Berlin↗
PubMed1987

[Efficacy of nasal O2 administration during mouth breathing].

27 subjects with healthy lungs received during conscious mouth breathing of room air simultaneously also nasally applied O2. The mean O2 concentration of the expiratory air at the mouth was a measure for the effective inspiratory oxygen concentration. Application through a nasal mask at 4 l/min O2 flow proved only slightly superior to the airtight nose frame (25.2 vs 23.6 per cent by volume O2), whereas the highest concentration was achieved by mask and reservoir (35.3 vol.%; 2P less than 0.001). The five habitual mouth breathers of the subject group did not show any O2 uptake through the nose in any of the experiments, the mean nasal share of the inspiration being calculated at 2.5% against 25% for the other subjects (2P less than 0.001). The interindividual differences proved independent of nose resistance and are ascribed to changing active positioning of the soft palate. This mechanism must be taken into consideration when assessing the arterial blood gases in oronasal respiration.

Adult↗
PubMed1987

[Mechanisms of supralaryngeal airway obstruction in normal persons and habitual mouth breathers].

We examined oronasal flow partitioning in 27 volunteers with normal or slightly increased nasal resistance (mean +/- SD, 0.24 +/- 0.19 kPa/l/s). Mean percentage of inspiratory nasal flow contribution was measured during spontaneous oronasal breathing. The averaged nasal admixture of airflow differed considerably within and between all subjects (mean +/- SD, 20.9% +/- 16.5%; range 1%-70%), showing no correlation to nasal resistance. Five of 27 subjects with a history of habitual mouth breathing had a significantly lower nasal admixture as compared with controls (2.5% +/- 1.7% vs 25.1% +/- 15.4%; P less than 0.005), but with no statistical difference in nasal resistance. To evaluate the hypothesis that velopharyngeal narrowing is due to an increased tone of the soft palate, measurements were also performed under positive nasal pressure, inspiratory resistive loading at the mouth, and during breath-holding. There was no significant difference of airflow distribution between these modifications and unloaded breathing in either group. These data suggest, therefore, that oronasal flow distribution is due to active positioning of the soft palate, and that habitual mouth breathing without any nasal obstruction may be associated with closure of the velopharyngeal isthmus as a consequence of disturbed neural control mechanisms.

Adult↗
PubMed1986

[Role of the nose in inspiration in mouth breathing: quantitative determination by analysis of expiratory gases].

It is widely accepted that increased nasal resistance plays a major role in habitual mouth breathing. We investigated oronasal air flow distribution during voluntary mouth breathing in subjects without nasal obstruction. To determine whether nasal air flow contributes to total inspiratory flow, we administered 100% O2 by a nasal mask while the lips were kept apart by a mouth piece. Expired O2 concentrations measured at the mouth were a sensitive indicator of nasal admixture during inspiration. Theoretical considerations predict that mixed expired pO2 from two consecutive steady state periods should allow calculation of nasal admixture. Measurements made on 22 healthy volunteers revealed a very variable degree of nasal contribution to inspiratory air flow (mean +/- SD, 25 +/- 15%, range 3-70%). There was no correlation between this proportion and anthropometric data, smoking habits, nasal resistance, or presence of rhinitis. We suggest that changes in the position of the soft palate, tongue, and/or pharyngeal wall associated with respiration are mainly responsible for the within and between subject variation observed in this study. This explanation is consistent with recent experimental findings on the pharyngeal dilating muscles.

Adolescent↗
PubMed1983

Surgical treatment of congenital esotropia.

We conducted a retrospective study of 133 children (69 boys and 64 girls) who underwent bilateral medial rectus muscle recession (most by the augmented or en-bloc technique) for congenital esotropia. Esotropia was diagnosed before the age of 6 months in 84 patients and after the age of 6 months in the other 49. A total of 27 children underwent surgery before the age of 12 months; of these, three required second procedures. A total of 106 children underwent surgery after the age of 12 months; of these, eight required second procedures. The mean preoperative deviation was 40 prism diopters. Two patients had significant A pattern deviations and 17 had significant V pattern deviations. Six patients had dissociated vertical deviations. Five to 60 days after surgery, 52 patients had no deviation and 99 were within +/- 10 prism diopters of no deviation. Two months after surgery, 67 patients had no deviation and 114 were within +/- 10 prism diopters of no deviation. Final alignments (five months to seven years postoperatively) showed that 51 patients had no deviation and 109 were within +/- 10 prism diopters of no deviation. Despite adequate alignment, none of 13 patients whose esotropia was diagnosed before the age of 6 months, who underwent surgery before the age of 12 months, and who cooperated with testing achieved stereopsis. This suggested that there may be two types of congenital esotropia--one without fusion potential and one in which fusion is possible but lost secondarily because of peripheral esotropic factors.

Child, Preschool↗
PubMed1979

[Epidemiology of malignant neoplasms of the breast, uterine cervix, endometrium, and rectum of females in the G.D.R., 1962--1972 (author's transl)].

Based on a model described earlier, the time trend of incidence, mortality, prevalence, duration of medical care and 5-years survival rate is calculated for the following malignant neoplasms of female population in the G.D.R.: breast, uterine cervix , corpus uteri and chorionephithelioma (combined), and rectum (ICD 8th, revision Nos. 174, 180, 181/182, 154). Calculated rates agree quite well with published observations. The results support the assumption that care of cancer patients could be improved between 1962 and 1972. Some suggestions for further development of cancer control are discussed.

Adult↗
PubMed1979

[Demographic and sociological setup of premature deliveries for live births in GDR 1973 (author's transl)].

A record was taken 1973 of 22,466 single and 3,287 multiple live births, with premature deliveries being subdivided by age, birth order, coverture, and vocational backgrounds of the mothers concerned. The distributions thus established have produced evidence to the effect that all the above factors may have an impact upon premature delivery. Yet, multiple births were found to distort the distributions of all parameters used. --- Reference is made to possible interpretations of such studies in terms of large-scale trends, resources, risk hypotheses, and clusters, with examples being proposed for the latter.

Adult↗