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91.
92.
Summary A C4 variant found in about 5% of the population is described. The fast-moving part of this variant is governed by an allele (F
x) codominant to F. The F
x allele is in very strong linkage disequilibrium with HLA-B17 as the linkage disequilibrium parameter accounted for nearly 100% of the haplotype frequency of B17, F
x. The strong association is also evidenced by the study of 11 families segregating for the F
x allele. There was no instance of recombination between C4 and HLA in 36 informative meioses. 相似文献
93.
Genetic markers controlled by 21 genetic systems were studied in 13 families containing members suffering from various hereditary disorders involving ataxia. Classical cerebellar ataxia was present in four, Friedreich ataxia in two, hereditary spastic paraplegia in four, and the Charcot-Marie-Tooth syndrome in three families. In each family, every available member above the lowest age at onset observed in that family, was subjected to a thorough clinical investigation and blood was sampled for investigation of genetic markers.The families with cerebellar ataxia and with Charcot-Marie-Tooth syndrome contained enough informative relatives to allow a formal linkage study using the lodscore method. Three of the pedigress with cerebellar ataxia gave evidence of linkage between the disease and the HLA system with a combined lodscore of 2.128 at a recombination fraction of 0.05 for both sexes combined. The recombination fraction was considerably higher in females than in males, although the difference between the two sexes was not statistically significant.Negative lodscores were obtained for the remaining family with cerebellar ataxia, which might be due to the fact that this family only provided information on recombination in females. However, the clinical features in this family differed from those in the other three families by a significantly higher frequency of dementia and pyramidal tract lesions. Based on these observations and on contradictory results in the literature concerning linkage between cerebellar ataxia and HLA, we suggest that there are two forms of cerebellar ataxia: One (CA1) linked to HLA with symptoms restricted to lesions in the cerebellum and spinocerebellar system and another (CA2) not linked to HLA with symptoms from more wide-spread lesions of the CNS.None of the other genetic markers (except perhaps GLO) showed linkage to the cerebellar ataxias. Negative lodscores throughout with all 21 genetic markers were found in the families with Charcot-Marie-Tooth syndrome.There was no evidence for linkage between HLA on the one hand and Friedreich ataxia or hereditary spastic paraplegia on the other.List of Abbreviations
HA
Hereditary ataxias
-
HLA
Major histocompatibility system
-
CA
Cerebellar ataxia
-
FA
Friedreich ataxia
-
HSP
Hereditary spastic paraplegia
-
CMT
Charcot-Marie-Tooth syndrome
-
MS
Multiple sclerosis
-
Hp
Haptoglobin
-
Gc
Group-specific component
-
PGM
Phosphoglucomutase, locus 1
-
SP (AcP)
Acid phosphatase
-
AK
Adenylatekinase
-
PGD
6-phosphogluconatedehydrogenase
-
ADA
Adenosinedeaminase
-
GPT
Glutamate pyruvat transaminase
-
GT
Galaktose-1-phosphat uridylyltransferase
-
EsP
Carboxylesterase D
-
GLO
Glyoxylase I
This study was aided by grants from Warwara Larsen's Foundation, the Danish Multiple Sclerosis Society and the Medical Research Council 相似文献
94.
Organ and isotype distribution of plasma cells producing specific antibody after oral immunization: evidence for a generalized secretory immune system. 总被引:28,自引:0,他引:28
P Weisz-Carrington M E Roux M McWilliams J M PHILLIPS-Quagliata M E Lamm 《Journal of immunology (Baltimore, Md. : 1950)》1979,123(4):1705-1708
Mice were induced to produce IgA antibodies against ferritin after oral immunization. Such antibodies were detected by immunofluorescence in plasma cells in the intestinal mucosa as well as in secretory sites located elsewhere, such as the lactating mammary gland, salivary gland, and respiratory tract. The observation suggested that cells immunized locally via the gut could home to distant secretory sites. To confirm this hypothesis, lymphocyte transfer studies were done with mesenteric node (MN) versus peripheral node (PN) cells from orally immunized donors into nonimmunized recipients. IgA anti-ferritin cells from MN homed to exocrine targets, whereas IgM and IgG anti-ferritin cells homed to PN. The findings overall support the concept of a generalized and interrelated secretory immune system. 相似文献
95.
96.
The microsphere method has been used extensively to measure regional blood flow in large laboratory animals. A fundamental premise of the method is that microspheres do not alter regional flow or vascular tone. Whereas this assumption is accepted in large animals, it may not be valid in the pulmonary circulation of smaller animals. Three studies were performed to determine the hemodynamic effects of microspheres on the rat pulmonary circulation. Increasing numbers of 15-microm-diameter microspheres were injected into a fully dilated, isolated-lung preparation. Vascular resistance increased 0.8% for every 100,000 microspheres injected. Microspheres were also injected into an isolated-lung preparation in which vascular tone was increased with hypoxia. Microspheres did not induce vasodilatation, as reported in other vascular beds. Fluorescent microspheres were injected via tail veins into awake rats, and the spatial locations of the microspheres were determined. Regional distributions remained highly correlated when microspheres of one color were injected after microspheres of another color. This indicates that the initial injection did not alter regional perfusion. We conclude that, when used in appropriate numbers, 15-microm-diameter microspheres do not alter regional flow or vascular tone in the rat pulmonary circulation. 相似文献
97.
R W Glenny W J Lamm S L Bernard D An M Chornuk S L Pool W W Wagner M P Hlastala H T Robertson 《Journal of applied physiology》2000,89(3):1239-1248
To compare the relative contributions of gravity and vascular structure to the distribution of pulmonary blood flow, we flew with pigs on the National Aeronautics and Space Administration KC-135 aircraft. A series of parabolas created alternating weightlessness and 1.8-G conditions. Fluorescent microspheres of varying colors were injected into the pulmonary circulation to mark regional blood flow during different postural and gravitational conditions. The lungs were subsequently removed, air dried, and sectioned into approximately 2 cm(3) pieces. Flow to each piece was determined for the different conditions. Perfusion heterogeneity did not change significantly during weightlessness compared with normal and increased gravitational forces. Regional blood flow to each lung piece changed little despite alterations in posture and gravitational forces. With the use of multiple stepwise linear regression, the contributions of gravity and vascular structure to regional perfusion were separated. We conclude that both gravity and the geometry of the pulmonary vascular tree influence regional pulmonary blood flow. However, the structure of the vascular tree is the primary determinant of regional perfusion in these animals. 相似文献
98.
Ethanol (10–200 mM) transiently increased tritium overflow from superfused rat nucleus accumbens slices previously incubated with [3H]dopamine (DA) and [14C]choline. The effect was greater in striatal tissue and did not appear to be a non-specific membrane effect since [14C]acetylcholine (ACh) release was not affected. Lack of antagonism by picrotoxin suggested that -aminobutyric acid (GABA) receptors were not involved. Calcium was not a requirement and the DA uptake blocker, nomifensine, was without effect. Ethanol appeared to be causing [3H]DA release into the cytoplasm. K+-stimulated release of [3H]DA and [14C]ACh from nucleus accumbens and striatal slices was not affected. Clonidine-mediated inhibition of the K+-evoked release of [3H]DA remained unaltered. Ethanol attenuated the isoproterenol-induced enhancement of [3H]DA release. Ethanol therefore appeared to interact with components of the DA terminal causing a transient increase in the release of neurotransmitter without impairing K+-evoked release but apparently interfering with the isoproterenol-induced effect. 相似文献
99.
Monoamine concentrations were low in the rostral area of the nucleus accumbens. Their distributions were not identical. Differences were observed in the medial area. DA concentrations were high in both medial and caudal areas. Noradrenaline (NA) and serotonin (5-HT) concentrations were considerably lower than the dopamine (DA) concentration. The NA concentration was highest in the caudal area of the nucleus accumbens and the (5-HT) concentration was highest in the ventrocaudal area. There was a rostrocaudal decrease in the 3,4-dihydroxyphenylacetic acid (DOPAC)/DA and 5-hydroxyindole-3-acetic acid (5-HIAA)/5-HT ratios. Uptake of [3H]DA and [14C]choline was lowest in the rostral area. The K+-stimulated release of [14C]acetylcholine (ACh) was also lowest rostrally, but there was no rostrocaudal difference in the K+-stimulated release of [3H]DA. These results provide further evidence of the heterogeneity of the nucleus accumbens. 相似文献
100.
Studies of esterase 6 in Drosophila melanogaster. XVIII. Biochemical differences between the slow and fast allozymes 总被引:1,自引:0,他引:1
Most natural populations of Drosophila melanogaster are polymorphic for two
major electrophoretic variants at the esterase-6 locus. The frequency of
the EST 6F allozyme is greatest in populations in warmer latitudes, whereas
the EST 6S allozyme is predominant in colder latitudes. Latitudinal clines
in electromorph frequencies are found on three continents. Purified
preparations of the allozymes have been characterized for their pH optimum,
substrate specificity, organophosphate inhibition, alcohol activation,
thermal stability, and kinetic parameters. These and previous analyses of
the EST 6 allozymes reveal that the two variants have differences in their
physical and kinetic properties that may provide a basis for the selective
maintenance of the polymorphisms and an explanation of the clinal variation
observed in natural populations.
相似文献