We recently have identified a ubiquitously transcribed mouse Y chromosome
gene, Uty , which encodes a tetratricopeptide repeat (TPR) protein. A
peptide derived from the UTY protein confers H-Y antigenicity on male
cells. Here we report the characterization of a widely transcribed X-linked
homologue of Uty , called Utx , which maps to the proximal region of the
mouse X chromosome and which detects a human X-linked homologue at Xp11.2.
Given that Uty is ubiquitously transcribed, we assayed for Utx expression
from the inactive X chromosome (Xi) in mice and found that Utx escapes X
chromosome inactivation. Only Smcx and the pseudoautosomal Sts gene on the
mouse X chromosome have been reported previously to escape inactivation.
The human UTX gene was also found to be expressed from Xi. We discuss the
significance of these data for our understanding of dosage compensation of
X-Y homologous genes in humans and mice.
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In a human in-vitro fertilization (IVF) programme, the effect of co-
culture of embryos with human fibroblasts was evaluated with respect to
pregnancy rate and embryo development. Patients were included in the study
after giving informed written consent. The IVF treatments were randomly
assigned by stratification of both age (<36 versus > or =36 years)
and previous IVF attempts (yes versus no). After fertilization was
established, the zygotes were transferred to a 4-well dish with or without
fibroblasts and cultured for 2 days. On the third day after ovum pick-up
(OPU), cell number and quality [5 (good) to 1 (poor)] of the embryos were
scored and a maximum of three embryos was transferred. Supernumerary
embryos of good quality were cryopreserved. The design of this study was a
group sequential trial with the objective of detecting differences between
pregnancy rates following IVF with conventional incubation or incubation in
co-culture with fibroblasts. This design included one evaluation at
half-way data collection. In the study, 148 patients had an OPU, of whom 77
were allocated to the co-culture group. There was no statistically
significant difference in pregnancy rate, cell number and embryo quality
between the two groups. The ongoing pregnancy rate per embryo transfer was
27% in co-culture and 30% in the conventional culture group. The
implantation rates per transferred embryo were 17 and 18% respectively.
Using a multivariate logistic regression model for the probability of
ongoing pregnancies, the odds ratio of co-culture, adjusted for age and
previous IVF attempts, was not statistically significant. In conclusion,
co-culture with human fibroblasts does not contribute to an improvement of
embryo quality nor to a higher pregnancy rate after IVF in an unselected
group of patients.
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In-vitro maturation (IVM) of oocytes is a promising technique to reduce the
costs and avert the side-effects of gonadotrophin stimulation for in-vitro
fertilization (IVF). The pregnancy rates from oocytes matured in vitro are
much lower than those of in-vivo stimulation cycles indicating that
optimization of IVM remains a challenge. Therefore, we investigated the
effect of supplementation of the medium with gonadotrophins, oestradiol and
epidermal growth factor (EGF) and the effect of retaining or removing the
cumulus cells on nuclear and cytoplasmic maturation of immature oocytes.
Human germinal vesicle (GV) oocytes obtained after gonadotrophin
stimulation for intracytoplasmic sperm injection (ICSI) were cultured in a
complex defined medium either supplemented with gonadotrophins, oestradiol
and physiological concentrations of EGF (2 ng/ml) or gonadotrophins and
oestradiol alone. The cumulus cells were either removed or kept intact. In
GV stage oocytes cultured without cumulus (group I) significantly more
oocytes reached the metaphase II (MII) stage at 30 h in media supplemented
with EGF (64.3 versus 33.9%, P < 0.003). For oocytes cultured with
intact cumulus (group II), more oocytes reached MII at 30 h than in group
I, but there was no difference in medium with or without EGF
supplementation (81.8 and 79.8% respectively). Cytoplasmic maturation of
MII oocytes was judged from their capability to activate and fertilize
after ICSI. In group I, the rates of activation and normal fertilization
were similar. However, in group II, significantly more oocytes underwent
normal fertilization in the EGF-supplemented than the unsupplemented group
(71.7 versus 45.6%, P < 0.05). The cleavage rates of the fertilized
oocytes were similar in the sibling oocyte subgroups cultured with or
without EGF supplementation, but the overall cleavage rates were higher in
cumulus-intact compared to cumulus-denuded oocytes (88.9 versus 47.8%, P
< 0.001). Thus, supplementation of the maturation medium with EGF and
maintenance of the cumulus during culture improve the nuclear and
cytoplasmic maturation of human oocytes in vitro.
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BACKGROUND: Sepsis and death subsequent to the transfusion of blood containing Yersinia enterocolitica is an increasing problem. The organisms probably originate from bacteremia in the donor and can subsequently multiply at low temperature. STUDY DESIGN AND METHODS: Reported here are experiments with a strain of Y. enterocolitica associated with a case of transfusion-associated bacteremia. RESULTS: It was found that the rapid early killing of Y. enterocolitica injected into donated blood does not require viable phagocytes and can be explained by complement-mediated killing. Complement resistance in Y. enterocolitica is known to be plasmid-coded. It is expressed at 37 degrees C, but not at 20 degrees C, and is favored by calcium-deficient culture media. Y. enterocolitica organisms induced to express complement resistance were still killed in donated blood, though the initial rate was slower. Such organisms multiplied in plasma at 37 degrees C, but were killed after 6 hours of incubation at 20 degrees C, presumably because complement resistance genes are switched off at this temperature. CONCLUSION: This experiment is thought to reflect the natural history of Y. enterocolitica contamination of blood, in which complement-resistant organisms in the donor blood encounter lower temperatures after donation. These observations suggest that the practice of plasma depletion may have contributed to the increased incidence of mortality due to Y. enterocolitica contamination of donated blood. 相似文献
OBJECTIVE: To compare the incidence, symptomatology and course of mastocytosis with onset in childhood and in adults. DESIGN: Retrospective study of 101 patients with mastocytosis who were referred from 1980 to 1998. PATIENTS: Medical records of 65 cases of mastocytosis with onset in childhood and 36 in adulthood were analysed. The clinical course was assessed in a subgroup consisting of 33 subjects with childhood onset who were followed up until at least adolescence and 12 subjects with adult onset who were followed up for at least 10 years. RESULTS: The onset of the disease occurred before the age of 2 years in 50% and between the ages of 2 and 15 years in 14% of cases (childhood onset). In 36% of patients onset occurred at the age of 16 years and older (adult onset). An incidence peak of 60% was noted in the first year of life. Mast cell-mediated symptoms were not experienced by 21 of 36 adult onset mastocytosis patients nor by 27 of 65 childhood onset mastocytosis patients. Complete resolution was observed in five of 33 children. The majority of childhood onset cases (21 of 33) showed some improvement. Complete resolution was achieved in three of 12 adults. The majority of the remaining adults (eight of 12) showed no improvement. CONCLUSIONS: We confirm the incidence of onset of mastocytosis previously reported in the literature. We conclude that childhood onset mastocytosis is much less transitory than generally is assumed, although improvement occurs in the majority of cases. Symptomatology and clinical course of adult onset mastocytosis is less severe than suggested in the literature. 相似文献
Pruritus in hepatic cholestasis has been suggested to be secondary to a high concentration of serum bile acids. Rifampicin, which inhibits the uptake of bile acids by hepatocytes, has been used to treat pruritus. To determine the efficacy of rifampicin as a treatment for refractory pruritus, the medical records of 33 children (median age 25 months, range 4-135; 19 boys) with chronic cholestasis liver disease (21 with Alagille's syndrome, eight with progressive intrahepatic cholestasis, one with extrahepatic biliary atresia, one with an inborn error of bile acid metabolism, and one with cryptogenic cirrhosis) were reviewed retrospectively. The median dose of rifampicin was 5(4-10) mg/kg/day. The median duration of intake was 36(4-120) weeks. Complete relief of pruritus was noted in five (15%) patients and a partial response in 12 (36%). Overall, no significant difference was noted in the laboratory parameters before and after treatment with rifampicin. In the 21 patients with Alagille's syndrome, however, a significant decrease in alkaline phosphatase was seen before and after one and six months of starting treatment. No adverse side effects were seen. Rifampicin appears to be effective in the treatment of refractory pruritus. A prospective study is warranted to assess further the effect of rifampicin treatment in children with hepatic cholestasis. 相似文献
Introduction: Tubulin inhibitors including taxanes and vinca alkaloids are important components of chemotherapy regimens used in advanced non-small cell lung cancer (NSCLC). Despite a treatment paradigm shift due to molecularly-targeted therapies and immunotherapy, a majority of patients will receive chemotherapy during their treatment course. Either used alone or in combination, tubulin inhibitors have demonstrated clinical benefits in different settings of lung cancer management.
Areas covered: This review first discusses FDA-approved tubulin inhibitors for NSCLC, such as paclitaxel, docetaxel, vinorelbine, and nab-paclitaxel. The article then provides a summary of novel tubulin inhibitors, including cabazitaxel, eribulin, ixabepilone, patupilone, plinabulin, new colchicine analogues and others. It also discusses new tubulin inhibitor combinations with immunotherapy (PD-1/PD-L1 inhibitors) and molecularly-targeted therapies (e.g. anti-angiogenic agents, mTOR inhibitors, heat shock protein 90 inhibitors, MEK inhibitors, and anti-HER3 agents). Lastly, emerging data on potential resistance mechanisms and predictive biomarkers for tubulin inhibitors are explored.
Expert opinion: Tubulin inhibitors will likely continue to play important roles in NSCLC management due to the advent of novel agents and combinations. Through further understanding of tumor biology, investigation of drug resistance, and development of predictive biomarkers, we will be better positioned to incorporate microtubule inhibition into patient specific treatment strategies. 相似文献