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1.
《Cell reports》2020,30(4):1152-1163.e4
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2.
Jin Wei Mia Madel Alfajaro Peter C. DeWeirdt Ruth E. Hanna William J. Lu-Culligan Wesley L. Cai Madison S. Strine Shang-Min Zhang Vincent R. Graziano Cameron O. Schmitz Jennifer S. Chen Madeleine C. Mankowski Renata B. Filler Neal G. Ravindra Victor Gasque Fernando J. de Miguel Ajinkya Patil Huacui Chen Craig B. Wilen 《Cell》2021,184(1):76-91.e13
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3.
《Molecular cell》2020,77(6):1176-1192.e16
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4.
An unconfirmed study by Fang (Ph.D. thesis, Univ. of London, 1950) in Britain showed that individuals with Down syndrome had lower total a-b ridge counts in palmar Interdigital area II (ID II) than a group of controls. This study compares 603 white Down syndrome cases and 93 black Down syndrome cases with 668 white and 402 black controls. Our results confirm those of Fang in that the Down syndrome cases in both racial groups had lower total a-b ridge counts than their respective controls. In addition, the black controls and Down syndrome cases had lower a-b ridge counts than their white counterparts. The mean a-b ridge count was significantly lower in individuals with a pattern in ID II compared to individuals without a pattern in ID II in both the Down syndrome and control groups. Some of the lower a-b ridge counts in the Down syndrome samples can be accounted for by the fact that there is an increased frequency of a pattern in ID II in Down syndrome cases. Both Down syndrome and normal individuals who had a pattern unilaterally had a lower than expected a-b ridge count on the contralateral hand that did not have a pattern. There was a tendency also for increased asymmetry in Down syndrome cases with a pattern in ID II. 相似文献
5.
The mechanism of ‘down regulation’ of luteinizing hormone receptors was investigated in pseudopregnant rats using a modified
radioimmunoassay capable of measuring endogenous tissue-bound hormone. Treatment of pseudopregnant animals with a desensitizing
dose (desensitization treatment) of human chorionic gonadotropin resulted in a decrease in receptor concentration. This decrease
was prevented if the animals were treated prior to the desensitization treatment with indomethacin, an inhibitor of prostaglandin
biosynthesis, suggesting a role for prostaglandins in down regulation. The desensitization treatment resulted in a time-dependent
decrease in subsequent responsiveness of the tissue to luteinizing hormone. Basal progesterone production rate was also decreased
following desensitization. Total tissue cholesterol was found to be decreased following desensitization treatment, without
any change in the ratio of free to esterified cholesterol. Mitochondrial cholesterol was significantly reduced and pregnenolone
production by the mitochondria of desensitized corpora lutea was also markedly reduced. However, when cholesterol was added
to the mitochondria of desensitized corpora lutea, pregnenolone production was increased, reaching values almost equal to
that shown by the control mitochondria. These results show that decrease in the responsiveness following desensitization treatment
is due to, besides receptor loss, decrease in tissue cholesterol, in particular mitochondrial cholesterol. The cholesterol
side chain cleavage activity, although low, appears to be functionally intact; the low activity could be attributed to low
levels of mitochondrial cholesterol. 相似文献
6.
The accumulation of [3H]inositol by mechanically dissociated brain cells and cultured skin fibroblasts from fetal mice was examined. Uptake by both tissues was strongly dependent on temperature and the presence of sodium ions. Brain and fibroblast uptake also responded similarly to inhibition by inositol isomers and phloridzin. At lower concentrations of inositol, both tissues exhibited high-affinity uptake kinetics with apparent Km values near 30 M, similar to values observed previously in human fibroblasts and other cultured cells. The activity of brain high-affinity uptake was nearly an order of magnitude lower than that of fibroblasts, however, and was in part confounded by the presence of a low-affinity or simple diffusion system operating at inositol concentrations above 100M. Brain preparation from adult mice also showed evidence of high-affinity, Na+ dependent uptake, but its activity was significantly diminished relative to that of fetal brain preparations. Our results demonstrate that a high-affinity inositol transport system closely resembling that found in cultured cells is expressed in the developing mouse brain. 相似文献
7.
Abstract: A subclone of NG108–15 neuroblastoma-glioma hybrid cells was used to study the intracellular distribution of opioid receptors. Subcellular organelles were separated on self-generating Percoll-sucrose gradients and the enzymes β-glucuronidase, galactosyltransferase, 5′-nucleotidase, and glucose-6-phosphatase were used as markers to localize the various structures. Analysis of the receptor distribution from untreated cells shows that the plasma membranes contained the highest receptor density, but a significant portion of the opioid binding sites was unevenly distributed between the lysosomes, microsomes, and Golgi elements. The enzyme markers indicated that appearance of opioid receptors in these intracellular structures does not result merely from contamination with plasma membranes. About 11% of the receptors appeared in a fraction lighter than plasma membranes. The antilysosomal agent chloroquine altered the intracellular compartmentation of the receptors, possibly by blocking their translocation in the cells. Leu-enkephalin induced time-dependent loss of receptors from all four intracellular compartments examined, but a kinetic analysis showed that the rate of receptor loss in these fractions was not identical. Thus, the percent of receptors appearing in the lysosomal fraction that could still bind [3H]-D-Ala2D-Leu5-enkephalin in vitro was increased on treatment with Leu-enkephalin. As an additional approach to follow the intracellular fate of the receptors, cells were labeled with [3H]diprenorphine, chased with various unlabeled opiates, and the distribution of 3H-ligand-receptors in the cells was monitored. Leu-enkephalin and etorphine altered the distribution of receptor-bound [3H]diprenorphine between the plasma membranes, lysosomes, and Golgi elements, whereas morphine had no such effect. The study sheds light on the role of intracellular structures in the metabolism of opioid receptors in untreated and opioid-treated cells. 相似文献
8.
A. De Izuzquiza C. Ascaso E. Fernandez F. Ballesta 《International Journal of Anthropology》1986,1(1):19-23
Finger-prints of the parents of thirty four Down children were compared with thirty four couples with two or more normal children
without a family history of genetic problems.
The parents with children affected by translocation Down Syndrome and those with mosaicism were excluded. A comparison of
the figure distributions in each of the fingers of the two groups shows a different distribution.
Parents of children affected by Down Syndrome occupy an intermediate position between the parents of normal children and the
subjects affected by Down Syndrome.
The total sum of values of A (arch), Lu (ulnar loop), Lt (radial loop) and W in each of the groups were also compared using
a contingency table. A significant difference (p<0,05) was found between both groups. The differences are imputed to the variables
A and L. 相似文献
9.
32P-Labelled tRNA was isolated from uninfected and phage phi 149-infected Vibrio cholerae cells. These tRNA preparations were then hybridised with DNA isolated from phage phi 149. Significant hybridisation was observed only with tRNA from phage phi 149-infected cells. This strongly suggests that infection of classical vibrio with phage phi 149 results in the synthesis of phage-specific tRNA molecules. 相似文献
10.