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PubMed1975

[Caffeine as an inhibitor of the conjugation transfer of R-factors. A study of certain aspects of the mechanism of action of caffeine on the conjugation transfer of R-factors].

Some aspects of the inhibitory effect of caffeine on conjugation transfer of R-factors described by the authors earlier were studied. The effect of the above substance on the donor and recipient competence was tested in experiments with cultivation of the parent strains for 18 hours in the presence of caffeine. For this purpose the effect of caffeine on reduction of the donor and recipient cell competence after starvation in a physiological solution was investigated. It was shown that caffeine markedly decreased the donor competence of strain 15-3Mdrd of E. coli in the experiments of both types. Caffeine also inhibited reduction of the recipient competence of strain C600 of E. coli after starvation without its changing on 18-hour treatment. For the study of the caffeine effect on formation of the conjugation pairs experiments were carried out with dilution of the conjugation mixture after definite intervals which practically stopped formation of new conjugation pairs and eliminated further effect of caffeine on conjugation. Under such conditions transfer of R-factors may occur in the conjugation pairs after elimination of caffeine by dilution, if they were formed in the presence of caffeine before the mixture dilution. The experiments showed that caffeine inhibited not the formation of the conjugation pairs but the genetic transfer of R-factors. In addition, it was found that the substance insignificantly inhibited the process of phenotypic manifestation of the resistance markers. Inhibition of conjugation R-transfer by caffeine was associated with its eliminating effect, since the concentrations used did not induce elimination of the resistance markers in R+ strains.

Caffeine↗

PubMedDate not supplied

A comparison of magnetization transfer ratio, magnetization transfer rate, and the native relaxation time of water protons related to relapsing-remitting multiple sclerosis.

BACKGROUND AND PURPOSE: Magnetization transfer (MT) imaging and measurements of the magnetization transfer ratio (MTR) have extended our capability to depict and characterize pathologic changes associated with multiple sclerosis (MS). We wanted to investigate whether the analysis of other MT parameters, such as magnetization transfer rate (k(for)) and relative measure of water content (T1(free)), adds insight into MS-related tissue changes. METHODS: Quantitative MT imaging by use of phase acquisition of composite echoes was performed in nine patients with clinically definite relapsing-remitting MS and eight healthy control subjects on a 1.5-T MR system. We analyzed a total of 360 regions of interest and compared control white matter with various types of lesions and normal-appearing white matter in MS. RESULTS: We found a strong correlation between the MTR and k(for), but this relation was non-linear. A slight but significant reduction of the MTR in normal-appearing white matter of patients with MS was attributable to a reduced transfer rate only, whereas a lower MTR was associated with both a reduction of k(for) and an increase of T1(free) in regions of dirty white matter. Moreover, areas such as edema and T1-isointense lesions had a similar MTR but could be differentiated on the basis of Tl(free). CONCLUSION: Estimates of k(for) and T1(free) appear to complement MTR measurements for the understanding of MT changes that occur with different types of MS abnormalities in the brain.

Adult↗

PubMed1975

Adoptive transfer of experimental allergic encephalomyelitis (EAE): prevention of successful transfer by treatment of donors with myelin basic protein.

After onset of experimental allergic encephalomyelitis (EAE), guinea pigs can be effectively treated by injection with myelin basic protein (BP). In order to localize the site of action of BP, cells from sensitized donors treated with BP one, two, three, or four times after disease onset have been transferred to normal recipients. One injection of BP has no effect on ability of cells to transfer EAE. Two injections partially inhibit transfer. After the third and fourth injections the sensitized cells lose their capacity to transfer EAE. The therapeutic effect of BP previously demonstrated in actively sensitized guinea pigs must involve the specifically sensitized cells rather than the target organ.

Animals↗

PubMed1989

Pregnancies established by gamete intrafallopian transfer and pronuclear-stage transfer in patients with premature ovarian failure using donated oocytes and low-dose oral micronized estradiol and progesterone.

This report describes both gamete intrafallopian transfer (GIFT) and pronuclear-stage transfer (PROST) of donated oocytes to patients with premature ovarian failure (POF), using micronized oral progesterone (P4) and low-dose micronized estradiol (E2) for endometrial preparation and maintenance. Patient A, with POF of 15 years' duration, received four donated oocytes for GIFT and subsequently delivered a normal, term, female infant. Patient B was diagnosed as POF 3 years ago. She received four donated oocytes, which were subsequently fertilized in vitro with husband's sperm. The following day, four pronuclear-stage embryos were transferred to her fallopian tubes. She recently delivered twin, healthy female infants. These procedures, along with exogenous hormonal development of the endometrium, provide a simplified means to establish and maintain pregnancy in POF patients. Both patients were maintained on low-dose micronized E2 prior to their procedure, Patient A on 3 mg E2 per day cyclically and Patient B on 0.5 mg E2 continuously. Micronized oral P4 was used to maintain pregnancy.

Adult↗

PubMed1993

Conversion from a failed transcervical zygote intrafallopian transfer to a successful delayed uterine embryo transfer.

Transcervical ZIFT is an alternative to IVF-ET and laparoscopic GIFT. However, tubal catheterization cannot be accomplished in all cases. We describe a successful twin pregnancy that resulted from delayed uterine transfer of four embryos following unsuccessful TC-ZIFT transfer. Further data are needed to determine optimal management in cases of failed transcervical tubal transfer procedures.

Adult↗

PubMed1991

Different locations of cholesteryl ester transfer protein and phospholipid transfer protein activities in plasma.

Activities of cholesteryl ester transfer protein (CETP) and phospholipid transfer protein (PLTP) were measured in plasma of four vertebrate species: man, rabbit, pig, and rat. The activities were measured in the absence and presence of antibodies raised against purified human CETP. PLTP activities were present in all four species with highest values in pig (11.7 +/- 1.2 U/ml) and human plasma (9.2 +/- 1.6 U/ml). Considerable lower activities were found in rabbit (3.5 +/- 0.6 U/ml) and rat plasma (1.6 +/- 0.7 U/ml). These activities were not affected significantly by antibody against human CETP. CETP activities could be measured in human (0.23 +/- 0.05 U/ml) and in rabbit plasma (0.19 +/- 0.03 U/ml). CETP activity in human plasma was inhibited over 97% by antibody against human CETP. Plasma was chromatographed on a Superose 6 gel filtration column. Average HDL particle sizes in the four species differed notably and decreased in the order: rat HDL greater than rabbit HDL greater than human HDL greater than pig HDL. A separation of the two lipid transfer activities was evident after gel filtration chromatography. The peak of the PLTP activity coeluted with a fraction of HDL particles with the size of human HDL2 (particle weights 300-375 kDa). CETP activity in human and rabbit plasma coeluted largely with relatively small HDL particles (particle weights 140-180 kDa). These results show that CETP and PLTP activities are located in different macromolecular complexes.

Animals↗

PubMed2000

Zygote intrafallopian transfer in patients with tubal factor infertility after repeated failure of implantation with in vitro fertilization-embryo transfer.

OBJECTIVE: To evaluate the efficacy of zygote intrafallopian transfer (ZIFT) in terms of implantation and pregnancy rates in patients with tubal factor infertility and repeated implantation failure in IVF-ET cycles. DESIGN: Retrospective analysis of ZIFT cycles. SETTING: An IVF unit in a university hospital. PATIENT(S): Criteria for patient selection for ZIFT included at least four failures of implantation in IVF-ET cycles in which at least 3 embryos were replaced per transfer and a cause of infertility diagnosed as male, unexplained, or tubal factor with proof of one patient tube. INTERVENTION(S): Four to six zygotes were transferred by laparoscopy into the fallopian tube 24-26 hours after oocyte retrieval. MAIN OUTCOME MEASURE(S): Implantation and pregnancy rates were determined in 112 ZIFT cycles performed in 81 patients with repeated failure of implantation. Results were further stratified for patients with tubal factor (n = 15) and patients without tubal factor (n = 66). RESULT(S): The pregnancy and implantation rates for all ZIFT cycles were 35.1% and 11.1%, respectively. Pregnancy and implantation rates per cycle in patients with tubal factor versus patients without tubal factor were 26.6% versus 37.1% and 9.4% versus 11.4%, respectively. CONCLUSION(S): ZIFT can be considered as a mode of treatment for patients with repeated failure of implantation in IVF-ET and with tubal factor with proved patency of one tube.

Embryo Implantation↗

PubMed1993

A prospective randomized comparison of zygote intrafallopian transfer and in vitro fertilization-embryo transfer for nontubal factor infertility.

OBJECTIVE: To evaluate the efficacy of zygote intrafallopian transfer (ZIFT) versus standard IVF-ET for the treatment of nontubal factor infertility. DESIGN: A prospective randomized trial. PARTICIPANTS: Fifty-nine couples undergoing oocyte retrieval for nontubal infertility in a university hospital-based IVF-ET program. INTERVENTIONS: A maximum of four cleaving embryos were transferred into the fallopian tube or uterine cavity 48 or 55 hours after oocyte retrieval, respectively. MAIN OUTCOME MEASURES: Rates of implantation, pregnancy, and spontaneous abortion (SAB) were compared. RESULTS: Clinical pregnancies occurred after 26.5% versus 12% of retrievals and 29% versus 14.3% of transfers in IVF-ET versus ZIFT cycles, respectively. Pregnancy, implantation, and SAB rates did not differ between the groups. CONCLUSIONS: This prospective randomized trial failed to demonstrate any therapeutic improvement associated with the increased complexity of ZIFT as compared with standard IVF-ET.

Adult↗

PubMed2006

Transfer of inner cell mass cells derived from bovine nuclear transfer embryos into the trophoblast of bovine in vitro-produced embryos.

Presence of placental tissues from more normal noncloned embryos could reduce the pregnancy failure of somatic cloning in cattle. In this study, inner cell mass (ICM) cells of in vitro-produced (IVP) embryos was replaced with those of nuclear transfer (NT) embryos to reconstruct bovine blastocysts with ICM and trophoblast cells from NT and IVP embryos, respectively. A total of 65 of these reconstructed embryos were nonsurgically transferred to 20 recipient beef females. Of those, two females were diagnosed pregnant by ultrasonography on day 30 of gestation. One pregnancy was lost at 60-90 days of gestation, and the other recipient cow remained pregnant at day 240 of gestation; however, this female died on day 252 of gestation. Gross pathology of the internal organs of the recipient female, a large fetus, and a large placental tissue mass suggested the massive size of the fetus and placental tissue were likely involved in terminating the life of the recipient female. Biopsy samples were harvested from the skin of the dead recipient cow, the fetus and from cotyledonary tissue. Microsatellite DNA analysis of these samples revealed that the genotype of the fetus was the same as that of the NT donor cells and different from that of the recipient cow. Correspondingly, neither the fetus nor recipient cow had the same genotype with that of the fetal cotyledonary tissue. These results present the first known documented case of a bovine somatic NT pregnancy with nonclone placental tissues after transfer of a blastocyst reconstructed by a microsurgical method to exchange of ICM cells and trophoblast tissue between NT and IVP blastocysts.

Animals↗

PubMedDate not supplied

Liposome-mediated transfer of vascular endothelial growth factor cDNA augments survival of random-pattern skin flaps in the rat.

Tissue engineering is an application for gene therapy that is in its infancy. We show that simple liposomal-mediated gene transfer could result in a potentially useful biological effect in the field of wound healing. cDNA encoding the 165 amino acid form of vascular endothelial growth factor complexed to commercially available liposomes was injected into rat skin 1 week before raising a random pattern 3 x 10 cm flap. The flap survival was enhanced by 14 percent, and was accomplished without accessing the arterial inflow of the territory. These results were statistically significant (p<0.002) and reproducible. No adverse effects were seen. Histological analysis of the angiogenesis localized much of the new vessel formation to the area around the hair follicles. Polymerase chain reaction amplification of extracted flap tissue confirmed the presence of the transgene.

Animals↗

PubMed1999

Comparison of pronuclear stage embryo transfer and in vitro fertilization-embryo transfer following intracytoplasmic sperm injection.

To determine whether the mode of embryo transfer (PROST vs IVF) affected the outcome in intracytoplasmic sperm injection (ICSI) cycles, 237 ICSI cycles (106 PROST and 131 IVF) were analyzed. Several parameters, including patient age, duration of infertility, amounts of hMG used, number of mature eggs retrieved and injected, fertilization rate, number of embryos transferred, and clinical pregnancy rate, were compared. Most of the variable factors were not significantly different, except the mean numbers of transferred embryos which were significantly higher in the PROST group. The clinical pregnancy rate showed no statistical difference between PROST and IVF cycles (25.5 and 16.8%; p = 0.139). This study suggests that even the pregnancy rate in PROST cycles was slightly higher than IVF cycles, but there was no statistically significant difference between the two groups.

Adult↗

PubMed1991

Treatment of patients with unexplained infertility: gamete intrafallopian transfer (GIFT) versus tubal embryo transfer (TET).

This study compares the results of 65 cycles of gamete intrafallopian transfer (GIFT), and 19 cycles of tubal embryo transfer (TET) in couples with unexplained infertility (UI). Oocyte retrievals were carried out by laparoscopy in GIFT and transvaginally in TET, in which the embryos were transferred by laparoscopy into the fallopian tubes 48 hours later. The mean age, duration of infertility, serum estradiol levels on the day of human chorionic gonadotropin administration, number of large follicles (mean diameter greater than 10 mm) and the number of oocytes recovered were similar between these two groups. From the 65 GIFT cycles, 20 clinical pregnancies resulted (30.8%). From the 19 cycles of TET, 10 conceptions occurred (52.6%). The implantation and pregnancy rates after TET were higher than that after GIFT, but the differences were not statistically significant. The data suggest that GIFT has a similar success rate to TET in couples with UI.

Adult↗

PubMed1987

Serum prolactin response to embryo transfer during human in vitro fertilization and embryo transfer.

Serum prolactin (PRL) concentrations around the time of embryo transfer (ET) have not been studied, despite the fact that transient hyperprolactinemia regularly occurs in response to laparoscopy for oocyte recovery and ET itself may be stressful enough to induce a PRL rise. Hyperprolactinemia might compromise luteal support for implantation and contribute to the limited success of ET. We measured serum PRL concentrations in 10 normoprolactinemic women immediately before, during, and after ET and compared the PRL response around ET to that induced by laparoscopy as a measure of the competency of the stress-prolactin axis. Nine of ten patients demonstrated a significant PRL response to surgery. The mean (+/- SEM) intraoperative PRL concentration (124.0 +/- 19.6 ng/ml) was significantly higher than the preoperative level (12.3 +/- 2.4 ng/ml) (P less than 0.01). Three hours after surgery PRL levels had decreased (44.8 +/- 11.5 ng/ml) but remained above baseline. All subjects were normoprolactinemic 48 hr after laparoscopy. Serum PRL concentration did not change significantly in response to ET, with levels of 10.4 +/- 1.7, 12.4 +/- 1.1, and 10.6 +/- 1.8 ng/ml immediately before, during, and 3 hr after ET, respectively. While laparoscopy for in vitro fertilization--embryo transfer commonly induces hyperprolactinemia, the PRL rise is transient, with no carryover to the time of ET. Embryo transfer itself does not induce a significant PRL rise.

Embryo Transfer↗

PubMed1990

Investigation of lipid transfer in human serum leading to the development of an isotopic method for the determination of endogenous cholesterol esterification and transfer.

The rate at which radioactivity appeared in cholesteryl esters (CE) in whole serum and in very low density lipoproteins (VLDL) and low density lipoproteins (LDL) when radioactively labelled free cholesterol (FC) was incubated with serum was investigated. At 4 degrees C equilibration of radioactive FC with native FC occurred, but there was no conversion to CE. At 37 degrees C CE mass increased in parallel with radioactivity in CE both in whole serum and VLDL/LDL. Incubation at 37 degrees C with an inhibitor of lecithin cholesterol acyl transferase (LCAT) abolished the increase in the total CE radioactivity and mass in serum. Transfer of CE from high density lipoprotein (HDL) to VLDL/LDL, however, continued to occur. An assay for LCAT and for cholesteryl ester transfer protein (CETP) was developed, which employed the increases in radioactive CE in whole serum and VLDL/LDL during a single incubation as indices of LCAT and CETP activity, respectively. Determination of the initial serum FC concentration allowed the expression of these activities in nmol/ml per h. References ranges were established in 62 fasting normolipidaemic men and women and increases in both LCAT and CETP were found following a fatty meal. The experiments thus provided further information about the carrier-mediated transfer of CE from its site of esterification on HDL to VLDL/LDL and formed the basis of a relatively simple assay, which has advantages over previously published methods and which may be used in clinical and epidemiological studies to elucidate the role of CETP and LCAT in atherosclerosis.

Apolipoproteins↗

PubMed2003

Transfer of nonselected transferable day 3 embryos in low embryo producers.

OBJECTIVE: To examine the implantation potential of embryos from assisted reproductive technology cycles with low embryo production and to assess the effects of clinical variables and embryo scores (ES) on pregnancy outcome. DESIGN: Prospective clinical study. SETTING: Assisted reproductive technology unit in a tertiary medical center. PATIENT(S): From July 1998 to December 2001, 280 cycles in 229 infertile couples produced a limited number of one, two, or three embryos 3 days after oocyte retrieval and underwent fresh embryo transfer (ET). INTERVENTION(S): Embryos with two or more blastomeres were scored and transferred. MAIN OUTCOME MEASURE(S): ES and implantation rate per ET. RESULT(S): Of 863 fresh ET cycles during the study period, 32.4% (280) were low embryo producers. Among them, there were no significant differences in average ES of individual embryos in single, dual, or triple ET or in embryos obtained from patients with low or high E2 responses, or young or old age. Embryos derived from conventional IVF had a better ES than those derived from intracytoplasmic sperm injection. The clinical pregnancy rate was strongly correlated with the cumulative ES. Implantation rates were similar among and between groups, with an average rate of 15.9%. CONCLUSION(S): Embryos of low embryo producers had an inherently low implantation potential that appeared to be unrelated to the number of embryos transferred, female age, ovarian E2 genesis, or fertilization method. The cumulative ES can serve as a predictor of pregnancy.

Adult↗

PubMed2004

Cannulation of a resistant internal os with the malleable outer sheath of a coaxial soft embryo transfer catheter does not affect in vitro fertilization-embryo transfer outcome.

OBJECTIVE: To assess the impact of cannulation of a resistant cervical os with the outer malleable sheath of a double-lumen, soft ET catheter on IVF-ET outcomes. DESIGN: Retrospective cohort study. SETTING: University-based IVF center. PATIENT(S): One hundred forty-two patients undergoing 142 ETs. INTERVENTION(S): Trial ultrasound-guided ET at all transfers, leaving the malleable outer sheath in situ when the soft inner catheter could not negotiate the internal os. MAIN OUTCOME MEASURE(S): Implantation rate and clinical pregnancy rate. RESULT(S): In 102 ETs (71.8%), the soft inner sheath easily negotiated the internal os (group 1). Forty ETs (28.2%) required cannulation of resistant internal ora with the outer sheath of the trial catheter (group 2). Implantation rates (35% vs. 32% in groups 1 and 2, respectively) and clinical pregnancy rates (50% vs. 45%) were not significantly different between groups. Blood was present on the transfer catheter after ET more frequently in group 2 than in group 1 (55% vs. 15%); however, neither the implantation rate nor the clinical pregnancy rate were affected by the presence of blood. CONCLUSION(S): Cannulation of a resistant internal os by the malleable outer sheath and blood on the transfer catheter after ET do not have an adverse effect on implantation rate or clinical pregnancy rate.

Blood↗

PubMed2005

Ultrasound-guided miduterine cavity embryo transfer is associated with a decreased incidence of retained embryos in the transfer catheter.

After initiating a policy of ultrasound-guided miduterine cavity embryo transfer (ET) on August 1, 2001, the incidence of retained embryos in the transfer catheter declined significantly from 4.2% (46 of 1,101 ETs) during the time interval January 1, 2000 to July 31, 2001, to 0.7% (6 of 908 ETs) during the time interval August 1, 2001 to December 31, 2002. Blood on the transfer catheter (38% vs. 19%) occurred with significantly greater frequency at ET in which embryos were retained; ETs of > or =4 embryos were more likely to be associated with retained embryos than ETs of <4 embryos (3.7% vs. 2.2%), and both the clinical pregnancy rate (PR) and implantation rate (IR) were lower when embryo retention occurred at ET than they were when embryos were not retained (25% vs. 34% clinical PR; 12% vs. 19% IR).

Catheterization↗

PubMed1990

Improved pregnancy rates and outcome with gamete intrafallopian transfer when follicular fluid is used as a sperm capacitation and gamete transfer medium.

Follicular fluid (FF) is a dynamic medium rich in steroids, polypeptide hormones, and growth factors. Preovulatory FF can stimulate spermatozoal acrosome reaction. Moreover short preincubation of washed sperm with FF improves sperm performance in the hamster egg penetration assay. In the current study, FF was used to capacitate sperm and as a transfer medium in 131 gamete intrafallopian transfer (GIFT) procedures. Ham's F-10 medium (GIBCO, Grand Island, NY) with 50% maternal serum was used in another 29 GIFT procedures. In the Ham's F-10 group, 29 GIFT procedures were performed in 25 patients with a pregnancy rate of 21% per laparoscopy and 24% per patient. In the FF group, 131 GIFT procedures were performed in 100 patients with a pregnancy rate of 50% per laparoscopy and 66% per patient, with a 59% ongoing pregnancy rate per patient. The most significant improvement was in the male factor group with a pregnancy rate of 0% in the Ham's F-10 group and 44% per procedure in the FF group. We conclude that the use of FF for sperm capacitation and as a gamete transfer medium significantly improves GIFT pregnancy rates and outcome.

Acrosome↗