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Relative carriage rates of nuclear dehydrogenating clostridia in two populations of different colorectal cancer risk 下载免费PDF全文
Carriage of nuclear dehydrogenating clostridia has been associated with colon cancer and implicated in its aetiology. This study has compared the carriage of these organisms in a British population at high risk for the development of colon cancer with a low risk Nigerian population. Clostridia were found in all of the stools from both populations. Nuclear dehydrogenating clostridia were only found in the stools of the British subjects (32%). These results support the suggestion that the carriage rate of nuclear dehydrogenating clostridia in a population is related to the risk of colon cancer. 相似文献
4.
Development of hatching blastocysts from immature human oocytes following in-vitro maturation and fertilization using a co-culture system 总被引:8,自引:0,他引:8
Hwu YM; Lee RK; Chen CP; Su JT; Chen YW; Lin SP 《Human reproduction (Oxford, England)》1998,13(7):1916-1921
Recently, in-vitro maturation (IVM) of immature human oocytes recovered
from non-stimulated follicles has been applied in the treatment of
infertility. However, in previous reports, very few embryos cultured in
conventional medium have reached the expanded blastocyst stage following
in-vitro maturation and fertilization (IVM/IVF). The objective of this
study was to investigate whether the developmental competence of human
embryos following IVM/IVF could be enhanced by the use of a human ampullary
cell co-culture system. Immature human oocytes were aspirated from small
follicles at Caesarean section and then cultured in medium containing human
menopausal gonadotrophin for 36 to 48 h, followed by insemination. Zygotes
were randomly cultured either in conventional culture medium alone or in
the co-culture system. Of 48 embryos cultured in conventional medium alone,
all arrested at the 2-16- cell stage on day 3 after insemination. Of 46
embryos cultured in the co-culture system, 26 embryos (56.5%) arrested at
the 2-16-cell stage. Six embryos (13%) developed to the morula stage.
Fourteen embryos (30.4%) developed to expanded blastocysts and two
blastocysts were hatching on day 7 after insemination. We conclude that
co-culture significantly enhances the development of blastocysts in embryos
resulting from IVM/IVF.
相似文献
5.
Detection of chromosomes and estimation of aneuploidy in human spermatozoa using fluorescence in-situ hybridization 总被引:11,自引:0,他引:11
The development and application of fluorescence in-situ hybridization
(FISH) has opened the way for comprehensive studies on numerical chromosome
abnormalities in human spermatozoa. FISH can be rapidly applied to large
numbers of spermatozoa and thus overcomes the major limitation of
karyotyping spermatozoa after penetration of zona-free hamster oocytes. The
simultaneous hybridization of two or more chromosome-specific probes to
spermatozoa and subsequent detection of the bound probes using different
fluorescent detection systems enables two or more chromosomes to be
localized simultaneously in the same spermatozoon and provides a technique
for undertaking reasonable estimates of aneuploidy. The most commonly used
probes are those which bind to the centromeric region of specific
chromosomes. Most studies to date have concentrated on estimating
aneuploidy in spermatozoa from normospermic men, although reports are
beginning to appear on aneuploidy in spermatozoa from subfertile and
infertile men. Multi- probe FISH studies have generally reported disomy
(hyperhaploidy) estimates of 0.05-0.2% per chromosome. There is preliminary
evidence that some chromosomes such as X, Y and 21 are predisposed towards
higher rates of non-disjunction during spermatogenesis. There are also
suggestions of inter-donor variability in aneuploidy frequencies for
specific chromosomes, although this requires confirmation in larger
studies. While FISH is clearly a powerful technique that has many
applications in reproductive medicine, it must also be realized that it
does have limitations and the technology itself is still evolving and has
yet to be fully validated on spermatozoa.
相似文献
6.
Preliminary observations on polar body extrusion and pronuclear formation in human oocytes using time-lapse video cinematography 总被引:10,自引:17,他引:10
Payne D; Flaherty SP; Barry MF; Matthews CD 《Human reproduction (Oxford, England)》1997,12(3):532-541
In this study, we have used time-lapse video cinematography to study
fertilization in 50 human oocytes that had undergone intracytoplasmic sperm
injection (ICSI). Time-lapse recording commenced shortly after ICSI and
proceeded for 17-20 h. Oocytes were cultured in an environmental chamber
which was maintained under standard culture conditions. Overall, 38 oocytes
(76%) were fertilized normally, and the fertilization rate and embryo
quality were not significantly different from 487 sibling oocytes cultured
in a conventional incubator. Normal fertilization followed a defined course
of events, although the timing of these events varied markedly between
oocytes. In 35 of the 38 fertilized oocytes (92%), there were circular
waves of granulation within the ooplasm which had a periodicity of 20-53
min. The sperm head decondensed during this granulation phase. The second
polar body was then extruded, and this was followed by the central
formation of the male pronucleus. The female pronucleus formed in the
cytoplasm adjacent to the second polar body at the same time as, or
slightly after, the male pronucleus, and was subsequently drawn towards the
male pronucleus until the two abutted. Both pronuclei then increased in
size, the nucleoli moved around within the pronuclei and some nucleoli
coalesced. During pronuclear growth, the organelles contracted from the
cortex towards the centre of the oocyte, leaving a clear cortical zone. The
oocyte decreased in diameter from 112 to 106 microm (P < 0.0001) during
the course of the observation period. The female pronucleus was
significantly smaller in diameter than the male pronucleus (24.1 and 22.4
microm respectively, P = 0.008) and contained fewer nucleoli (4.2 and 7.0
respectively, P < 0.0001). After time-lapse recording, oocytes were
cultured for 48 h prior to embryo transfer or cryopreservation. Embryo
quality was related to fertilization events and periodicity of the
cytoplasmic wave, and it was found that good quality embryos arose from
oocytes that had more uniform timing from injection to pronuclear abuttal
and tended to have a longer cytoplasmic wave. In conclusion, we have shown
that time-lapse video cinematography is an excellent tool for studying
fertilization and early embryo development, and have demonstrated that
human fertilization comprises numerous complex dynamic events.
相似文献
7.
Pathways to care for alcohol use disorders 总被引:1,自引:0,他引:1
8.
Combination of fludarabine and mitoxantrone in untreated stages III and IV low-grade lymphoma: S9501. 总被引:2,自引:0,他引:2
William S Velasquez Danika Lew Thomas M Grogan C Harris Spiridonidis Stanley P Balcerzak Shaker R Dakhil Thomas P Miller Keith S Lanier Robert A Chapman Richard I Fisher 《Journal of clinical oncology》2003,21(10):1996-2003
PURPOSE: To determine the efficacy of combination fludarabine and mitoxantrone (FN) in untreated stages III and IV low-grade lymphoma. The major end point was to estimate progression-free survival (PFS) in all eligible patients. PATIENTS AND METHODS: Seventy-eight eligible patients were registered. Chemotherapy courses were administered every 4 weeks with mitoxantrone 10 mg/m2 on day 1 and fludarabine 25 mg/m2 on days 1, 2, and 3 for a total of six to eight cycles. Pneumocystis carinii prophylaxis was required. RESULTS: Seventy-three patients (94%) attained an objective response. Complete remission was demonstrated in 34 patients (44%) and partial remission was demonstrated in 39 patients (50%). With a median follow-up time of 5.5 years, the median PFS was 32 months, with a 4-year PFS rate of 38%. Median survival has not been reached and 88% of all patients are alive at 4 years. The application of the International Prognostic Index and serologic staging showed significant differences in PFS in all risk groups, whereas overall survival was markedly worse for the highest-risk group in either prognostic model. Three prior Southwest Oncology Group trials using a regimen of cyclophosphamide, doxorubicin, vincristine, and prednisone or a combination of prednisone, vincristine, methotrexate, cytarabine, cyclophosphamide, etoposide, nitrogen mustard, vincristine, procarbazine, and prednisone in similar patient populations demonstrated comparable clinical outcome, although the 4-year survival for FN was better. FN was well tolerated, but mild to severe reversible myelosuppression was noted. Other complications were rare. CONCLUSION: FN is an effective, safe chemotherapy combination for patients with advanced-stage, low-grade lymphoma. Clinical outcomes were comparable to prior published data using anthracycline-based regimens. 相似文献
9.
Patricia A Ganz Carol M Moinpour Donna K Pauler Alice B Kornblith Ellen R Gaynor Stanley P Balcerzak Gretchen S Gatti Harry P Erba Sheryl McCoy Oliver W Press Richard I Fisher 《Journal of clinical oncology》2003,21(18):3512-3519
PURPOSE: We describe the short and intermediate-term quality-of-life (QOL) outcomes in patients treated on a randomized clinical trial in early-stage Hodgkin's disease (Southwest Oncology Group [SWOG] 9133) comparing subtotal lymphoid irradiation (STLI) with combined-modality treatment (CMT). PATIENTS AND METHODS: Two hundred forty-seven patients participated in the QOL study (SWOG 9208), completing several standardized instruments (Symptom Distress Scale; Cancer Rehabilitation Evaluation System - Short Form; Medical Outcomes Study 36-Item Short-Form Health Survey Vitality Scale; and a health perception item), as well as questions about work, marital status, and concerns about having children. This article reports on results from baseline before random assignment, at 6 months, and at 1 and 2 years after random assignment. RESULTS: Patients receiving CMT experienced significantly greater symptom distress (P <.0001), fatigue (P =.001), and poorer QOL (P =.015) at 6 months than the STLI patients, reflecting a shorter time since completion of therapy in the CMT arm. Importantly, patients in the two groups did not differ on any outcomes at the 1-and 2-year assessments. Both patient groups reported significantly more fatigue before treatment than healthy reference populations, and fatigue did not improve in either group after treatment. CONCLUSION: This study demonstrated that patients with early-stage Hodgkin's disease experience a short-term decrease in QOL and an increase in symptoms and fatigue with treatment, which is more severe with CMT; by 1 year, however, CMT and STLI patients report similar outcomes. Fatigue scores for both arms were lower at baseline than scores for the general population and did not return to normal levels 2 years after random assignment. The mechanisms responsible for this lingering problem warrant further investigation. 相似文献
10.
CJ Stewart ECL Marrs S Magorrian A Nelson C Lanyon JD Perry ND Embleton SP Cummings JE Berrington 《Acta paediatrica (Oslo, Norway : 1992)》2012,101(11):1121-1127
Aim: To describe gut colonization in preterm infants using standard culture and 16S gene rRNA profiling, exploring differences in healthy infants and those who developed NEC/late onset sepsis (LOS). Methods: Ninety‐nine stools from 38 infants of median 27‐week gestation were cultured; 44 stools from 27 infants had their microbial profiles determined by 16S. Ordination analyses explored effects of patient variables on gut communities. Results: Standard microbiological culture identified a mean of two organisms (range 0–7), DGGE 12 (range 3–18) per patient. Enterococcus faecalis and coagulase negative staphylococci (CONS) were most common by culture (40% and 39% of specimens). Meconium was not sterile. No fungi were cultured. Bacterial community structures in infants with NEC and LOS differed from healthy infants. Infants who developed NEC carried more CONS (45% vs 30%) and less Enterococcus faecalis (31% vs 57%). 16S identified Enterobacter and Staphylococcus presence associated with NEC/LOS, respectively. Conclusions: Important differences were found in the gut microbiota of preterm infants who develop NEC/LOS. The relationship of these changes to current practices in neonatal intensive care requires further exploration. 相似文献