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Biomedical subjects

F Barnes

Publications and source records attributed to F Barnes.

At least 19 recordsLinked to original sources
PubMed2006

Wide range of chromosome abnormalities in the embryos of young egg donors.

Embryo chromosome studies show high rates of abnormalities, above 50%, but most embryos studied were from patients aged 35 and older. The objectives of this study were firstly, to evaluate the rate of chromosome abnormalities in embryos from young egg donors, and secondly, to compare the range of chromosome abnormality rates between donors and non-egg donor cycles, both undergoing preimplantation genetic diagnosis (PGD) for infertility using fluorescence in-situ hybridization analysis with probes for chromosomes X, Y, 13, 15, 16, 18, 21, and 22. On average, only 43% of the embryos were chromosomally normal, while the comparison group had euploidy rates between 34 (age group 18-34) (P < 0.001) and 21% (age group 40-45) (P < 0.001). There was considerable variation between donor cycles, with almost one-third having less than 30% normal embryos. Also, within donors and recipients repeating several IVF cycles with PGD, only 29-56% of the second PGD cycles had similar rates of normal embryos to the first cycle, while in the comparison group it was 64%. The results can explain why some egg donors are successful whereas others are not, and may also show that a policy of PGD for first time egg donors is appropriate and indicated.

Adolescent↗
PubMed2006

Sleep and fatigue in multiple sclerosis.

Fatigue is common in multiple sclerosis (MS) and is an important cause of disability. However, the cause of fatigue is poorly understood. This study aimed to describe the frequency and pattern of sleep disturbance in a group of outpatients with MS, and to investigate the relationship between sleep disturbance and fatigue. Sixty outpatients with MS completed the Fatigue Severity Scale (FSS) and the Epworth Sleepiness Scale and kept a sleep diary for seven days. Fatigue and excessive daytime sleepiness were common in this group of patients (64 and 32%). Sleep problems on at least two nights per week occurred frequently, including initial insomnia in 42%, middle insomnia in 53% and terminal insomnia in 58%. The reasons cited for different types of insomnia varied, with anxiety and pain/discomfort being the commonest causes of initial insomnia and nocturia the commonest cause of middle insomnia. Middle insomnia was significantly correlated with daytime fatigue, a relationship that remained after controlling for disability. Sleep disturbance is common in MS and is associated with treatable symptoms, including pain and nocturia. Sleep disturbance may be an important factor contributing to fatigue in patients with MS.

Adult↗
PubMed2005

A theoretical study of the effects of RF fields in the vicinity of membranes.

In this article the forces associated with the gradients of a radio frequency (RF) field at the boundary between fluids and cell membranes are calculated, and it is shown that they can be large enough to affect the particle motion by amounts that are on the same order of magnitude as the random diffusion motion when the energy imparted to the particles is a reasonable fraction of the thermal energy. The induced dipole moment is assumed to track the alternating RF so that the force exerted by the gradient is in a constant direction; and this in turn leads to a modification of the particle distribution, even when the energy added to the particle is very small. For RF fields of 45 V/m the energy acquired by an induced dipole moment is expected to be on the order of a micro electron volt and small compared to the average thermal energy.

Animals↗
PubMed2004

The antidiabetic activity of the herbal preparation ADD-199 in mice: a comparative study with two oral hypoglycaemic drugs.

The antidiabetic and antioxidant effects of the herbal preparation ADD-199 were investigated in STZ-induced diabetic C(3)H mice and results were compared with two allopathic hypoglycaemic drugs, glibenclamide and metformin. Plasma glucose, insulin and lipids as well as liver glycogen, lipids and lipid peroxidation were measured following treatment for 8 weeks. The results indicated that plasma insulin levels in normal controls at termination were about 76 micromol/L compared to trace levels in untreated diabetic mice. Glibenclamide and ADD-199 increased insulin levels in diabetic mice up to 70% of levels in untreated non-diabetic mice whilst metformin had no effect. Basal plasma glucose levels in diabetic controls (18.8 mM) were reduced to 14.0 mM by 100 mg/kg ADD-199 in <2 weeks compared to 4 and 6 weeks for glibenclamide and metformin, respectively. This hypoglycaemic effect of ADD-199 appeared to be associated with the alkaloidal content of the extract. Treatment with ADD-199 or the hypoglycaemic agents reversed the observed elevation in plasma lipids but increased hepatic glycogen, triacylglycerol and cholesterol levels. Treatment also increased glucose uptake by isolated diaphragms and attenuated hepatic lipid peroxidation. These antihyperglycaemic and antioxidant actions of ADD-199 at a dose of 100mg/kg/day are comparable to those of the maximum daily therapeutic doses of glibenclamide (0.25 mg/kg) and metformin (50 mg/kg). These could explain the basis for use of this plant extract to manage diabetes mellitus (DM).

Administration, Oral↗
PubMed2004

Predictability of preimplantation genetic diagnosis of aneuploidy and translocations on prospective attempts.

The aim of this study was to determine if the outcomes of aneuploidy and translocation testing by preimplantation genetic diagnosis (PGD) at the 8-cell stage have a predictive value for new genetic diagnosis cycles. In total, 83 cycles (39 patients) undergoing PGD of translocations and 378 cycles (176 patients) of aneuploidy were included. Predictability, defined as having similar rate (+/-20%) of euploid embryos in the first and successive cycles, was found in 66% of patients undergoing aneuploidy testing. Predictability was found significantly more often in patients undergoing PGD of translocations (90%, P = 0.006). In addition, patients with 0, <30 or > or =30% euploid embryos in the first cycle were compared and groups 0 and <30% had significantly fewer euploid embryos in the second cycle (22-26%) than those of the group with > or =30% (37%) (P < 0.05). Patients who did not become pregnant after the first attempt were stimulated more aggressively than those becoming pregnant, producing significantly more embryos in the second than in the first cycle (P < 0.001). Therefore, correlation between euploidy rate and pregnancy rate could not be assessed objectively between cycles. In conclusion, the PGD results of a first cycle can predict the results of the second cycle, but this is likely to be of more value when the condition investigated is translocation rather than aneuploidy. The chance of pregnancy is usually related to the number of euploid embryos.

Abortion, Habitual↗
PubMed2000

An outbreak of asthma in a modern detergent factory.

The striking decrease in the occurrence of protease-induced occupational asthma in the detergent Industry has been attributed to enzyme encapsulation. We report an outbreak of asthma, at least equal in size to those reported in the 1960s, in a modem European factory which has exclusively used encapsulated enzymes. A survey revealed that enzyme sensitisation and work-related respiratory symptoms were positively correlated with airborne enzyme exposure. We suggest that encapsulation alone is insufficient to prevent enzyme-Induced allergy and asthma.

Adolescent↗
PubMed2000

Luteal phase start of low-dose FSH priming of follicles results in an efficient recovery, maturation and fertilization of immature human oocytes.

In this prospective study we investigated whether the maturation and fertilization of immature oocytes can be improved by administration of recombinant follicle stimulating hormone (rFSH) starting in the late luteal phase in two groups of women: group 1 (n = 6) women with regular menstrual cycles; and group 2 (n = 6) women with irregular cycles and polycystic ovaries (PCO) on ultrasound examination. Low-dose (37.5 IU) rFSH was commenced 11 days after LH surge during a spontaneous menstrual cycle and on the ninth day of progesterone administration in an irregular cycle. Recombinant FSH was continued until the leading follicle was approximately 10 mm in diameter. The oocytes were retrieved after withdrawing rFSH for 2-5 days. In total, 136 oocytes were recovered (group 1, 67 oocytes; group 2, 69 oocytes). Nine of the oocytes from PCO women were atretic at retrieval. Oocytes complete with cumulus cells were cultured for 44 h in complex tissue culture medium supplemented with gonadotrophins and fetal calf serum. After maturation, the cumulus cells were removed and metaphase II oocytes were injected with spermatozoa. Respectively, the oocyte maturation and fertilization rates were 64 and 72% in group 1, and 78 and 57% in group 2 (not significant). After fertilization, the zygotes (group 1, n = 22; group 2, n = 11) and cleavage stage embryos (group 1, n = 9; group 2, n = 15) were frozen in propanediol. All women except one (11/12) had approximately five zygotes or cleaved embryos frozen. The viability of in-vitro matured frozen-thawed embryos was generally poorer than that (81%) seen after conventional intracytoplasmic sperm injection, with 61% survival in group 1 and 23% in group 2. Fifteen embryo transfers resulted in one miscarriage at 6 weeks gestation. The late luteal start of low-dose rFSH yielded a good number of immature oocytes in women with both regular and irregular cycles. Two out of three of these oocytes matured and fertilized. However, cryosurvival of the zygotes and cleaved embryos was unsatisfactory and thus cryopreservation of in-vitro matured embryos may not be an optimal procedure.

Adult↗
PubMed1997

Transcription and translation in bovine nuclear transfer embryos.

The development of bovine embryos reconstructed by nuclear transfer (NT) is poor compared to that of embryos produced by in vitro fertilization. One reason for this could be incomplete reprogramming of the transferred nucleus. Therefore, with a view to optimizing the conditions for NT, the reprogramming of blastomere nuclei from 16- to 32-cell-stage in vitro-fertilized (IVF) embryos was investigated following NT by fusion of individual blastomeres with cytoplasts prepared from oocytes at two different stages of maturation. Heterogeneous RNA (hnRNA) production, nucleolar ultrastructure, and protein profiles of the NT embryos up to the 8-cell stage were analyzed. In all NT embryos analyzed for their hnRNA production (n = 133), [3H]uridine incorporation was higher at the 1-, 2-, and 4-cell stages than in control IVF embryos (n = 50). Ultrastructural examination of 11 NT embryos revealed evidence of transcriptional activity; fibrillar and granular components were seen in the nucleolus at the 1-cell stage. At the 2-, 4-, and 8-cell stages, fibrillar components were still evident but granular components had become scarce. The hnRNA synthesis, however, was not reflected in the one-dimensional electrophoretic patterns of protein production in the NT embryos (n = 56); these were largely similar to those of IVF embryos (n = 34) of corresponding stages. Thus, NT embryos made in this way do not behave like equivalent IVF embryos, suggesting that reprogramming of the transferred nucleus is absent or incomplete.

Animals↗
PubMed1996

Reducing the amount of cytoplasm available for early embryonic development decreases the quality but not quantity of embryos produced by in vitro fertilization and nuclear transplantation.

The effect of reducing the amount of cytoplasm available for early embryonic development was investigated in embryos produced by in vitro fertilization (IVF) and nuclear transplantation. In Experiment 1, approximately 1/2 or 1/20 of the cytoplasm was removed from bovine embryos at the pronuclear-stage of development. The percentage of embryos developing to the compact morula or blastocyst stage was significantly higher in non-manipulated controls (26%) than in embryos with 1/20 of the cytoplasm removed (16%), and those with 1/2 of the cytoplasm removed (10%; P < 0.05). There was also a significant difference in the average number of cells between blastocysts in which 1/20 of their cytoplasm was removed (67), those with 1/2 of their cytoplasm removed (55), and nonmanipulated controls (77; P < 0.05). In Experiment 2, nuclear transfer embryos were produced in which approximately 1/2 or 1/20 of the cytoplasm was removed during oocyte enucleation. The percentage of embryos developing to the blastocyst stage was 17% for both groups of nuclear transfer embryos compared to 44% for control embryos (P < 0.05). The mean number of cells in blastocysts produced by nuclear transfer in which 1/20 of the cytoplasm was removed during oocyte enucleation (61) was no different than that in control embryos (66), but significantly higher than the mean number of cells in blastocysts produced by nuclear transfer in which 1/2 of the cytoplasm was removed (42; P < 0.05). There was no indication that altering the amount of cytoplasm available for early embryonic development of IVF embryos affected the timing of differentiation events, including those of embryo compaction and blastocyst formation.

Journal Article↗
PubMed1993

Laparoscopic vs. open wedge biopsy of the liver.

This study was a post-hoc evaluation of laparoscopic versus open wedge biopsy of the liver performed as part of prospective phase I antibiotic trial. Consenting patients undergoing elective cholecystectomy were enrolled in a protocol which required samples of bile, blood, the gallbladder, and 1 gram of liver tissue. The study occurred during the evolution of laparoscopic surgery. Liver biopsy was done in standard fashion and laparoscopic liver biopsy was accomplished with cauterized scissors. Twenty-four patients, 4 male and 20 female averaging 42.1 years of age, were entered in this study. Eighteen patients underwent laparoscopic surgery and six patients underwent open surgery. They did not differ significantly in age (43.9 vs 42.1 years), operating room time (58.3 min vs 55.8 min), or complications (2/18 vs 2/6). Patients undergoing laparoscopic surgery, however, did have a shorter hospital stay (1.1 days vs 3.5 days, p < 0.001). All liver specimens were considered adequate. There were no complications related to the liver biopsy. Laparoscopic wedge biopsy of the liver is both a feasible and viable alternative to open wedge biopsy.

Adult↗
PubMed1993

Embryo cloning in cattle: the use of in vitro matured oocytes.

In vitro matured (IVM) bovine oocytes were examined to determine their potential viability in embryo cloning. Activation competence, as monitored by pronuclear formation, increased with oocyte age. Oocytes readily formed a pronucleus when challenged with an electrical pulse 30 h after the onset of maturation. Developmental competence of IVM oocytes tended to increase with oocyte age (P = 0.079). Selection of IVM oocytes on the basis of the presence of a polar body 24 h after the onset of maturation and the size of the follicle from which the oocyte was derived improved development of nuclear transfer embryos (polar body positive 25% versus polar body negative 10%, P < 0.05; large follicle oocytes 31% versus small follicle oocytes 14%, P < 0.05). When selected, IVM oocytes were compared with in vivo matured oocytes recovered from superovulated cows and heifers; no difference was detected for the frequency of embryos produced, pregnancies confirmed between days 50 and 60 of gestation, or the number of calves born. We conclude that selected IVM oocytes are equivalent to in vivo matured oocytes when used for bovine embryo cloning.

Animals↗
PubMed1991

Modification of the 1979 "Denver wire code" for different wire or plumbing types.

This article examines "wire configuration coding" as used to estimate relative residential AC magnetic field exposure in epidemiological studies--and the need to alter such coding for time or locations other than those in which the code was developed. Effects of different secondary wire practices are particularly examined.

Colorado↗
PubMed1989

Use of wiring configuration and wiring codes for estimating externally generated electric and magnetic fields.

The relative locations and characteristics of the distribution lines feeding 434 residences in the Denver metropolitan area were recorded and classified according to the Wertheimer-Leeper code (WL code) as a part of an epidemiological study of the incidence of childhood cancer. The WL code was found to place the mean values of the fields in rank order. However, the standard deviations were approximately the same size as the means. Theoretical calculations indicate that a significant fraction of the low-power magnetic fields can be generated by the distribution lines, especially in the cases where the distribution lines are within 50 feet of the residence. Thus, the wiring code was shown to be a useful method for making a first-order approximation to predict long-term, low-level magnetic fields in residences.

Building Codes↗
PubMed1987

Nuclear transplantation in bovine embryos.

This study was conducted to develop a method for transplanting nuclei in bovine embryos and to test the development of several stages of donor nuclei transplanted to enucleated pronuclear recipient embryos. Pronuclear embryos were centrifuged to reveal nuclei. Nuclei were removed without penetrating the plasma membrane as membrane-bound karyoplasts, and were inserted into enucleated zygotes by electrically induced cell fusion. The highest rate of fusion (79%) occurred in Zimmerman Cell Fusion medium at 100 V for 20 to 40 microseconds with the fusion membranes oriented parallel to the electrodes. The effect of nuclear transplantation on development was tested in pronuclear embryos in which nuclei were removed and reinserted and the embryos were then transferred to sheep oviducts for 5 d. Of the intact nuclear transplant embryos recovered, 5/29 (17%) developed to morulae or blastocysts compared with 11/30 (37%) of the non-manipulated embryos. Two nuclear transplant embryos were transferred to a recipient cow, and both developed to normal offspring. When nuclei from two-, four-, or eight-cell embryos were transplanted to pronuclear recipient embryos, no development was observed.

Animals↗