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91.
Cooper David N. Smith Barbara A. Cooke Howard J. Niemann Susanne Schmidtke Jörg 《Human genetics》1985,71(3):201-205
Summary Patients with recessive X-linked ichthyosis
Patients with recessive X-linked ichthyosis (RXLI), one hereditary form of scaly skin, lack activity of the enzyme steroid
sulfatase in all tissues studied. To investigate the molecular defect underlying the lack of enzyme activity, we prepared
antisera against normal enzyme by injecting normal placental microsomal suspensions or partially purified steroid sulfatase
into rabbits. Antibody activity was assessed by immunoprecipitation of detergent solubilized steroid sulfatase. In addition,
we prepared rabbit antisera against RXLI placental microsomal suspensions. To detect immunologically cross-reactive material
in patients' placentas, extracts were studied by immunoblot techniques and by competition with normal enzyme for antibody
binding. Patients' extracts did not contain immunoreactive material co-migrating on electrophoresis with purified enzyme nor
did they inhibit immunoprecipitation of normal enzyme. Sera from rabbits immunized with RXLI placental microsomes contain
no antibodies to normal steroid sulfatase, as judged by their failure to immunoprecipitate normal enzyme or to react with
normal steroid sulfatase on immunoblot. Thus the mutation in RXLI appears to reduce steroid sulfatase enzyme protein as well
as enzyme activity.
Portions of this material have appeared in abstract form in Clinical Research 31:564A, 1983 and 32:138A, 1984 相似文献
92.
93.
Barbara A. Brennessel Kathleen J. Keyes 《In vitro cellular & developmental biology. Plant》1985,21(7):402-408
Summary The artificial sweetener saccharin inhibits binding of epidermal growth factor (EGF) to cultured rat pituitary tumor cells
(GH4C1 cells). Saccharin also causes morphological alterations in these cells, resulting in pronounced elongation, stretching, and
firmer attachment of cells to the culture dishes. These alterations in cell shape are similar to those observed after treatment
of GH4C1 cells with EGF and with thyrotropin-releasing hormone (TRH), both of which enhance prolactin (PRL) production in these cells.
After assaying for PRL in saccharin-treated cultures, it was observed that this sweetener is also capable of stimulating PRL
production two-to sixfold in a dose-dependent manner. Enhancement of PRL production can be observed at 0.5 mM saccharin, yet this is 10 times less than the saccharin concentration required to alter cell shape. These effects of saccharin
on cell morphology and on PRL production are reversible in GH4C1 cell cultures. When added to cultures along with maximal concentrations of EGF or TRH, the effects of saccharin on PRL production
are additive, suggesting that the actions of saccharin are mediated by a somewhat different pathway from that of the peptide
hormones. Pulse labeling studies indicate that the enhancement of PRL production is highly specific inasmuch as saccharin
was found to decrease the overall rate of protein synthesis in these cells. Saccharin also causes a decrease in the rate of
DNA synthesis under these treatment conditions. Mitomycin C, which similarly inhibited DNA synthesis, had no effect on cell
morphology or PRL production.
This investigation was supported by a Faculty Research Grant from Wheaton College 相似文献
94.
Giorgio M. Hanozet Barbara Giordana Paolo Parenti Andrea Guerritore 《The Journal of membrane biology》1984,81(3):233-240
Summary In brush border membrane vesicles from the midgut ofPhilosamia cynthia larvae (Lepidoptera) thel- andd-alanine uptake is dependent on a potassium gradient and on transmembrane electrical potential difference. Each isomer inhibits the uptake of the other form: inhibition ofl-alanine uptake byd-alanine is competitive, whereas inhibition ofd-alanine uptake byl-alanine is noncompetitive. Transstimulation experiments as well as the different pattern of specificity to cations suggest the existence of two transport systems. Kinetic parameters for the two transporters have been calculated both when Kout>Kin and Kout=Kin.d-alanine is actively transported also by the whole midgut, but it is not metabolized by the intestinal tissue. 相似文献
95.
A method is described for the extraction of enkephalin-like peptides from peripheral nerve using chloroform and acidic methanol to facilitate a differential extraction of peptides and lipid. Porcine splanchnic nerve contains enkephalin-like peptides in low amounts compared to porcine adrenal medulla and striatum. Gel filtration chromatography reveals the presence of enkephalin-like peptides in both processed and cryptic forms. This is the first reported isolation and partial characterization of these peptides in splanchnic nerve. The presence of these peptides in this nerve provides support for the contention that the splanchnic nerve can modulate catecholamine release from the adrenal medulla through an effect on opiate receptors located on chromaffin cells. 相似文献
96.
Barbara Stay Lynda S. Ostedgaard Stephen S. Tobe Alain Strambi Eugene Spaziani 《Journal of insect physiology》1984,30(8):643-651
The free (non-conjugated) ecdysteroid in the ovaries during the first gonadotrophic cycle of Diploptera punctata was identified as 20-hydroxyecdysone. The hormone, quantified by radioimmunoassay and by ultraviolet absorbance, was detectable in the ovary toward the end of vitellogenesis; the quantity increased rapidly during chorion formation. Ovaries with chorionated eggs contained 67 μg of 20-hydroxyecdysone per g fresh weight. The haemolymph free-ecdysteroid, not identified physicochemically, was quantified by radioimmunoassays. The highest concentration was observed at adult emergence; the titre declined between days 1–3 and then remained at a relatively constant level through oviposition (which occurs between day 7 and 8); titres in pregnant females were higher. Ovariectomized females exhibited the same pattern of ecdysteroid titres in the haemolymph as the sham operated controls throughout the period corresponding to the first gonadotrophic cycle. Thus the ovary may not be the only source of haemolymph ecdysteroid related to reproduction in adult females. 相似文献
97.
Dynamics of orange peel fermentation during ensilage 总被引:2,自引:0,他引:2
G. Ashbell G. Pahlow Barbara Dinter Z. G. Weinberg 《Journal of applied microbiology》1987,63(4):275-279
The dynamics of fermentation during ensilage were studied on orange peel (variety Shamouti) ensiled in 50 plastic containers, 10 kg in each, with an outlet for seepage. At predetermined intervals the containers were weighed and samples were taken from three of them for chemical and microbial analysis. Fermentation losses amounted to up to ca one-third of the fresh peel dry matter (DM) content. Most losses occurred within 10 d of commencement of fermentation, and were attributable to gas release. The major fermentation products were ethanol, lactic and acetic acids (16, 3 and 3% of DM, respectively). The dominant microbial populations were lactobacilli and yeasts. Tests are in progress to inhibit the yeasts and thereby reduce fermentation losses. 相似文献
98.
Barbara A. Israel Warren I. Schaeffer 《In vitro cellular & developmental biology. Plant》1987,23(9):627-632
Summary Using both normal and transformed rat liver epithelial cells to prepare cytoplasmic hybrids (cybrids) we have found evidence
to support the theory that the cytoplasm from a normal cell can suppress tumorigenicity. A unique aspect of this study is
that all of the cells utilized, both normal and malignantly transformed, were derived from an original cloned cell. We found
that fusing cytoplasts from normal cells to malignantly transformed whole cells resulted in cybrid clones which, when injected
into newborn rat pups, isogenic with those from which the cell culture was initiated, yielted tumors in 51% of the animals
injected compared to 92% of the animals injected with the tumorigenic parent. Those animals that did develop tumors from the
cybrid cells survived longer than those injected with cells from the tumorigenic parent. Thus, the cybrid, formed of cytoplasm
from both parents, was less tumorigenic than the malignantly transformed parent cell. When reconstituted cells were prepared
by fusing cytoplasts from normal cells with karyoplasts from malignantly transformed cells, a situation in which essentially
all of the cytoplasm of the reconstituted cell is derived from normal cells, the tumorigenic phenotype was extinguished.
This work was supported in part by United States Public Health Service grant CA12056, and grant CA09100 from the National
Cancer Institute, Bethesda, MD. This work is partial fulfillment for the degree of Doctor of Philosophy for B.A.I. 相似文献
99.
G. Gray Eaton Deanne F. Johnson Barbara B. Glick Julie M. Worlein 《Primates; journal of primatology》1986,27(2):141-150
We have quantitatively documented the development of sex differences in the behavior of juvenile Japanese macaques (1 to 2
years of age). Mothers treated their offspring differently by sex, i.e., mothers of males broke contact with them more frequently
than did mothers of females. Juvenile males played more, and mounted other macaques more frequently; juvenile females groomed
their mothers more and were also punished by other group members more frequently than were males. Males showed a pattern of
decreasing interactions with their mothers, but females increased the frequency of their maternal interactions. These patterns
appear to presage the life histories of the sexes. However, comparisons with other species of nonhuman primates indicate that
although sex differences in behavior are common, the variability among species severely limits cross-specific generalizations. 相似文献
100.
Analyses for phytate by an indirect precipitation method and for the minerals calcium (Ca), zinc (Zn), iron (Fe), copper (Cu),
and manganese (Mn) by atomic absorption spectrophotometry were carried out on 100 foods available in New Zealand. Foods with
1% phytate (dry weight basis) included untoasted muesli, rolled oats, wheat germ, wheat bran, soybean, and some soy products.
Most breads contained between 0.35 and 0.60% phytate; legumes on average had 0.62% phytate, as did snack bars. There was a
wide variation in Ca and Zn contents: There was a tenfold variation in Ca content among the legume products, whereas there
was a seventyfold variation in Zn content among the cereals. The phytate: Zn molar ratio, which is presumed to indicate the
biovailability of Zn, was above 20∶1 for two-thirds of the cereals and almost all of the snack bars; it was above 15∶1 for
one-third of the breads, almost all of the legumes, and half of the legume products. These high phytate: Zn molar ratios,
as well as some Ca: phytate molar ratios above 6∶1, indicate that there might be a reduced biovailability of Zn in many of
the foods analyzed in this study. 相似文献