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  • 1
    ISSN: 1744-313X
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Biologie , Medizin
    Notizen: (CBA × B10)F1 [(H-2k x H-2b)] mice produce two types of antigen-specific T-suppressor factor (TsF), which can be separated by affinity chromatography on anti-I-J monoclonal antibody. After reduction and alkylation, both chains of F1 TsF are required for biological activity. However, the antigen-binding chain (AgBC) of F1 TsFk (AgBCk) is only complemented by I-Jk and likewise for F1 TsFb. In other words, interchain complementation shows the same genetic restriction in interchain complementation in parental and F1 mice. F1 TsF bearing, for example, I-Jk (TsFk), interacts with haptenized ‘antigen-presenting cells’ (‘APC’) of both parental haplotypes, and may be described as showing dual reactivity. In contrast, it is known that parental TsF shows single reactivity, and only interacts with haptenized ‘APC’ of the parental haplotype. The combination of F1 AgBCk and parental I-Jk chains interacts with haptenized ‘APC’ of both parental haplotypes (dual reactivity). In contrast, the combination of parental AgBCb and F1 I-Jb shows single reactivity and only interacts with haptenized ‘APCb’. It was inferred that the antigen-binding chain is responsible for the dual reactivity and, hence, for the interaction with a member of the I-J hierarchy on the ‘APC’. It was concluded that the antigen-binding chain of TsF has two recognition sites for members of the I-J hierarchy—one for interchain complementation and the other for interaction with the haptenized ‘antigen-presenting cell’. The term member of fhe I-J hierarchy is used instead of I-J because it is not clear whether the AgBC interacts with I-J or a receptor for I-J, or indeed a receptor for that receptor.
    Materialart: Digitale Medien
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  • 2
    Digitale Medien
    Digitale Medien
    Springer
    Cellular and molecular life sciences 44 (1988), S. 777-779 
    ISSN: 1420-9071
    Schlagwort(e): Crystal cells ; hemolymph ; lymph gland ; melanotic tumor
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary 3rd instar larvae of the melanotic tumortu-pb strain ofDrosophila melanogaster hold a lower number of free-circulating crystal cells in their hemolymph than the wild type ones. This pattern could result from an abnormal retention of mature crystal cells in the hematopoietic organs, as the strong hemocyte melanization inside the lymph glands of heat-treatedtu-pb larvae seems to demonstrate. Melanotic tumor formation and modification of the crystal cell pattern may be related.
    Materialart: Digitale Medien
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  • 3
    ISSN: 1432-0428
    Schlagwort(e): Lipoproteins ; Type 1 (insulin-dependent) diabetes ; blood glucose control ; lipoprotein composition ; atherosclerosis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Plasma lipoprotein compositional abnormalities were investigated in eight normolipidaemic (plasma cholesterol 〈5.70 mmol/l; triglyceride 〈2.03 mmol/l) young male Type 1 (insulin-dependent) diabetic patients (before and after a short period of optimised blood glucose control) and in nine healthy control subjects, matched for sex, age and body mass index. Free and esterified cholesterol, triglyceride, phospholipids were assayed in all lipoprotein classes (VLDL, IDL, LDL) and in HDL subclasses (HDL2 and HDL3); apoB was measured only in very low density lipoproteins (VLDL). All VLDL constituents were increased in the diabetic group, the differences being more striking for apoB (6.0±1.1 mg/dl vs 2.0±0.1 mg/dl, p〈0.02), free cholesterol (0.27±0.04 mmol/l vs 0.13±0.02 mmol/l, p〈0.02) and esterified cholesterol (0.32±0.08 mmol/l vs 0.13±0.01 mmol/l, p〈0.05). Also HDL subfractions showed differences between the two groups: all HDL2 constituents were increased, while in HDL3 only triglyceride was significantly increased (0.11±0.01 mmol/l vs 0.08±0.004 mmol/l, p〈0.02). After two weeks of optimised blood glucose control all VLDL constituents were reduced and particularly: esterified cholesterol (−39%, p〈0.02), free cholesterol (−37%, p〈0.05), apoB (− 35%, p〈0.05). Expressing each VLDL constituent as percent of the total lipoprotein mass, it was evident that the diabetic VLDL was rich in cholesterol both esterified (8.4±1.0% vs 5.4±0.5%, p〈0.02) and free (8.5±0.7% vs 5.5±0.3%, p〈0.001), apo B (5.1±0.6% vs 2.6±0.3%, p〈0.001) and depleted in triglyceride (57.0±1.7% vs 64.1±1.7%, p〈0.001). Two weeks of optimised blood glucose control were not able to correct the abnormal composition of VLDL. In conclusion, Type 1 (insulin-dependent) diabetic patients, although normolipidaemic, show an abnormal VLDL composition suggesting an increased prevalence of smaller and, possibly, more atherogenic VLDL particles. This abnormality is not corrected by a short period of blood glucose optimisation.
    Materialart: Digitale Medien
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  • 4
    ISSN: 1432-1076
    Schlagwort(e): Necrotizing enterocolitis ; Premature infants
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The perinatal histories of 27 newborn infants with NEC were compared to those of 54 infants of equivalent birth weight who did not have NEC during an 8-year study period to see if possible predisposing factors were independent of the confounding effect of birth weight. No differences were observed in gestational age, degree of intrauterine growth retardation, premature rupture of membranes, perinatal asphyxia, skin temperature at admission, haematocrit, presence or absence of respiratory distress syndrome, umbilical catheter placement, start and type of feeding or presence of positive blood cultures. Prematurity is the greatest risk factor predisposing to the development of NEC and the perinatal problems which precede the onset of NEC are common among all premature infants.
    Materialart: Digitale Medien
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  • 5
    Digitale Medien
    Digitale Medien
    Springer
    Experimental brain research 76 (1989), S. 21-26 
    ISSN: 1432-1106
    Schlagwort(e): Preprotachykinin gene ; Hypothalamus estrogen ; Ovariectomized rats
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary We have determined the localization of preprotachykinin (PPT) mRNA-containing neurons in the mediobasal hypothalamus of the rat. PPT mRNA-containing neurons are present in the ventromedial nucleus (with a concentration in the ventrolateral aspect (VL-VM)), the dorsomedial nucleus, the lateral hypothalamus and the arcuate nucleus. This distribution is consistent with the findings of immunocytochemical studies of substance P-immunoreactive neurons in the hypothalamus. We have also examined whether PPT gene expression is regulated by estrogen in the VL-VM by comparing the levels of PPT mRNA in the VL-VM of ovariectomized rats and ovariectomized, estrogen-replaced rats. Both in situ hybridization and slot blot hybridization analysis revealed no changes in PPT mRNA content in the VL-VM following estrogen treatment. These results suggest that estrogen does not regulate lordosis behavior by affecting PPT gene expression in VL-VM neurons.
    Materialart: Digitale Medien
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  • 6
    Digitale Medien
    Digitale Medien
    Springer
    Colloid & polymer science 265 (1987), S. 696-703 
    ISSN: 1435-1536
    Schlagwort(e): Isotacticpolypropylene ; morphology ; drawing ; fibers properties
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau
    Notizen: Abstract Quenched films of isotactic polypropylene were obtained in different quenching conditions; the films structure was analyzed in terms of phases composition and gross morphology. The mechanical behaviour, analyzed at room temperature in monoaxial drawing shows that the initial structure strongly affects the drawing behaviour. The drawing occurs by necking propagation in all the samples, but the deformation in the neck depends on the gross morphology while the drawing load depends on crystallinity. The obtianed results are discussed on the basis of the molecular and structural model of the fibers formation by drawing of crystalline polymeric films.
    Materialart: Digitale Medien
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  • 7
    Digitale Medien
    Digitale Medien
    Springer
    European journal of epidemiology 3 (1987), S. 176-180 
    ISSN: 1573-7284
    Schlagwort(e): Hepatitis B virus ; Vaccine
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Intradermally (I.D.) administered reduced doses of HB-Vax and Hevac-B were tested against the standard protocols for administering these two vaccines. Immunogenicity, efficacy and possible side effects were evaluated. Four-hundred-sixty-two healthy subjects were vaccinated as follows: Fifty-two subjects received HB-Vax and 99 Hevac B according to the standard regimens. The remaining subjects received 3 I.D. injections in the deltoid region at one-month intervals in the following doses: 165 subjects with 2 μg doses of HB-Vax, 118 subjects with 1 ug doses of Hevac-B and 28 subjects with 0.5 μg (minimal) doses of Hevac-B. Post-vaccination tests (anti-HBs titres and other serological markers for HBV) were to be performed 30, 60, 90, 180, 270 and 360 days after the first injections. Side effects seen with the experimental protocols were acceptable and limited to local reactions. It was found that, on the whole, reduced I.D. doses of both vaccines produced very high immune responses showing a consistently greater efficacy than those of the standard protocols, though the differences were not always statistically significant. Ninety days after the first injections, 80.8% and 82.7% of subjects vaccinated with reduced I.D. doses of HB-Vax showed seroconversion as opposed to only 62.0% of those receiving standard protocol HB-Vax. Seroconversion rates at 90 days in subjects receiving reduced I.D, doses of Hevac-B were 92.0% and 87.996 and for those receiving the minimal doses of this vaccine, 94.1% The rate of seroconversion obtained with standard administration of Hevac-B was 83.8%. The antibody titres in the experimental groups tended to increase up to the 180th day and were generally higher than those obtained with standard protocols. The titres remained very high 270 days after the first injection.
    Materialart: Digitale Medien
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  • 8
    Digitale Medien
    Digitale Medien
    Springer
    European journal of epidemiology 5 (1989), S. 202-206 
    ISSN: 1573-7284
    Schlagwort(e): Children ; Hepatitis B markers ; Hepatitis B virus ; Infection
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Possible hepatitis B immunization of all newborns, regardless of the mother's HBsAg status, is a strategy under consideration for selected hyperendemic areas in Italy. Sardinia is one such area. However, in 1987 in Sardinia, the prevalence of hepatitis B markers in children under 11 years was estimated at 1.7% and the prevalence of hepatitis B surface antigen (HBsAg) at 0.2%. A much higher prevalence of HBsAg was recently observed among adults in this area: 8.7% among men and 5.2% among pregnant women. This contrasting pattern is unlikely to be due to bias: the sampling procedures adopted were appropriate and the percentage of refusals was very low (2.2%). The observed low hepatitis B marker prevalence in young age groups might be the result of a cohort effect due to the improved socio-economic conditions and changes in behaviour that have occurred in Sardinia over the last few years. The finding of only 3 HBsAg+ individuals out of 1,826 children tested, in spite of the 5.2% HBsAg prevalence among pregnant women in that region, is probably attributable to the low proportion of HBeAg positive individuals among the HBsAg+ carrier mothers in this area. At present, immunization of all newborns in Sardinia cannot be recommended.
    Materialart: Digitale Medien
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  • 9
    Digitale Medien
    Digitale Medien
    Springer
    Journal of materials science 22 (1987), S. 4207-4214 
    ISSN: 1573-4803
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Maschinenbau
    Notizen: Abstract Four commercial bisphenol-glycidilmethacrylate based composites used mainly for dental applications have been investigated. Differential thermal analysis performed on samples aged in water for different times indicated a small residual monomer reactivity which disappeared after ageing. A further crosslinking reaction facilitated by water plasticization and a monomer loss could be the main reasons for such 8 phenomenon. The embrittlement of these materials with ageing time has been detected from flexural mechanical properties. Water sorption/desorption experiments have been performed on G!! the materials studied at different temperatures. The decrease of diffusion coefficients with increasing water content together with the microscopic analysis of the fracture surfaces demonstrated good filler/matrix adhesion for all the four composites. The decrease of water diffusion coefficients with time for Miradapt, Silar and Adaptic has been explained on the base of the presence in the polymeric networks of different density regions due to inhomogeneous polymerization. This hypothesis is also in line with the Miradapt, Silar and Adaptic hysteresis phenomena observed in the sorption/desorption cycles.
    Materialart: Digitale Medien
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  • 10
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 38 (1989), S. 249-256 
    ISSN: 0021-8995
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Samples of crosslinked cis-polybutadiene were crystallized at different temperature and drawing degree. The melting behavior of the crystallized samples was analyzed detecting the retractive stress as a function of temperature. The experimental melting data were extrapolated to the equilibrium conditions to obtain the thermodynamic melting temperature as a function of the drawing degree. The extrapolated data were analyzed with different theoretical approaches. Results agree with a model in which chain-folding and extended-chain crystallization can coexist, depending on crystallization temperature and drawing degree.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
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