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951.
An intrafascicular electrode for recording of action potentials in peripheral nerves 总被引:12,自引:0,他引:12
Mark S. Malagodi Dr. Kenneth W. Horch Andrew A. Schoenberg 《Annals of biomedical engineering》1989,17(4):397-410
We are developing a new type of bipolar recording electrode intended for implantation within individual fascicles of mammalian
peripheral nerves. In the experiments reported here we used electrodes fabricated from 25 μm diameter Pt wire, 50 μm 90% Pt-10%
Ir wire and 7 μm carbon fibers. The electrodes were implanted in the sciatic nerves of rats and in the ulnar nerves of cats.
The signal-to-noise ratio of recorded activity induced by nonnoxious mechanical stimulation of the skin and joints was studied
as a function of the type of electrode material used, the amount of insulation removed from the recording zone, and the longitudinal
separation of the recording zones of bipolar electrode pairs. Both acute and short term (two day) chronic experiments were
performed.
The results indicate that a bipolar electrode made from Teflon™-insulated, 25 μm diameter, 90% Pt-10% Ir wire, having a 1–2 mm long recording zone, can be used for recording of peripheral
nerve activity when implanted with one wire inside the fascicle and the other lead level with the first lead, but outside
the fascicle. No insulating cuff needs to be placed around the nerve trunk. 相似文献
952.
Chronically implanted intrafascicular recording electrodes 总被引:6,自引:0,他引:6
Todd Lefurge Eleanor Goodall Kenneth Horch Larry Stensaas Andrew Schoenberg 《Annals of biomedical engineering》1991,19(2):197-207
A newly designed intrafascicular electrode for chronic neural recording was studied by implanting 12 electrodes in the radial
nerves of 6 cats for 6 months. Action potentials were monitored at specified intervals throughout the experiment. The number
and size of the signals recorded suggest that this type of electrode provides information that is appropriate for feedback
control in functional electrical stimulation (FES) systems. Histology of the nerve revealed that the implants are biocompatible
and that little damage is caused by the presence of the electrode. 相似文献
953.
Britton JA Gammon MD Kelsey JL Brogan DJ Coates RJ Schoenberg JB Potischman N Swanson CA Stanford JL Brinton LA 《Women & health》2000,31(2-3):81-96
Data on 1,501 control women from a multi-center, population-based, case-control study of breast cancer were used to examine characteristics associated with recreational exercise during the year prior to the interview among women 20 to 44 years of age. In a univariate analysis, higher levels of recreational exercise were associated with: higher education; higher family income; white race; previous participation in recreational exercise above the median level at ages 12 to 13 and at age 20; being nulliparous; ever lactating; being a never or past smoker; having a low current Quetelet's index (QI: weight in kilograms divided by height in meters squared); and living in Atlanta or Seattle (compared to New Jersey). In a multiple linear regression model, independent predictors of higher levels of recreational exercise were: participation in higher levels of exercise at 20 years of age; having a low current QI; and never having smoked. Though all women should be encouraged to participate in exercise, these findings identity subgroups of women that may need targeting when developing exercise intervention programs. 相似文献
954.
Kerdelhue B; Lenoir V; Kolm P; Seltman HJ; Jones HW Jr; Jones GS 《Human reproduction (Oxford, England)》1997,12(2):231-235
Changes in plasma concentrations of ACTH, beta-endorphin (beta-EP) and
cortisol have been found to be associated during the human menstrual cycle.
Changes in hypothalamic levels of gonadotrophin releasing hormone (GnRH),
beta-EP and substance P (SP) have also been associated with the oestrous
cycle in the rat. Therefore, an attempt was made to measure the activity of
the corticotrophic axis and SP by measuring blood and follicular fluid
concentrations of ACTH, beta-EP, SP and corticotrophin releasing hormone
(CRH) during the hormonal ovarian stimulation phase for in-vitro
fertilization (IVF), in a series of 19 patients. At the plasma level, there
was no significant change over treatment days in ACTH (P = 0.1550), beta-EP
(P = 0.1137), or SP concentrations (P = 0.5625). CRH was not detectable
over treatment days. In addition, there was no significant change in
neuropeptide over treatment days between those women who became pregnant
and those who did not (P = 0.17 for all). In the follicular fluid, ACTH was
not detectable, beta-EP concentration was three times higher than in the
plasma, CRH was detectable, and SP concentration was similar to that of
plasma. There was no apparent correlation, however, between beta-EP or SP
concentrations in the plasma and follicular fluid from a given patient. In
conclusion, the absence of changes in the activity of the corticotrophic
axis during the hormonal ovarian stimulation suggests that there was no
major stress component associated with the stimulation phase of IVF or the
occurrence of a pregnancy.
相似文献
955.
Gammon MD Schoenberg JB Teitelbaum SL Brinton LA Potischman N Swanson CA Brogan DJ Coates RJ Malone KE Stanford JL 《Cancer causes & control : CCC》1998,9(6):583-590
Objectives: To evaluate whether heavy cigarette smoking as a teenager or long-term smoking increases breast cancer risk or, alternatively, whether smoking acts as an anti-estrogen and reduces risk.Methods: Data from a multi-center, population-based, case-control study among women under age 55 were analyzed.Results: Among women under age 45, there was a modest inverse relation with current (OR=0.82, 95% CI=0.67, 1.01) but not past (OR=0.99, 95% CI=0.81, 1.21) smoking. Odds ratios were decreased for current smokers who began at an early age (0.59 for15, 95% CI=0.41, 0.85) or continued for long periods of time (0.70 for >21 years, 95% CI=0.52, 0.94). In subgroup analyses, reduced odds ratios were observed among current smokers who were ever users of oral contraceptives (0.79, 95% CI=0.63, 0.98), were in the lowest quartile of adult body size (0.53, 95% CI=0.34, 0.81), or never or infrequently drank alcohol (0.68, 95% CI=0.47, 0.98). Among women ages 45-54, there was little evidence for an association with smoking.Conclusions: These results suggest that breast cancer risk among women under age 45 may be reduced among current smokers who began smoking at an early age, or long-term smokers, but require confirmation from other studies. 相似文献
956.
957.
Jonathan A. Fletcher Harry P. Kozakewich Marlena L. Schoenberg Cynthia C. Morton 《Genes, chromosomes & cancer》1993,6(1):24-29
Characteristic cytogenetic aberrations have been reported in adult lipomas and liposarcomas, but few karyotypes have been reported for pediatric adipose neoplasms. In this report we describe a consistent rearrangement, der(8)(pter→q13::q24.1→qter), in 2 of 3 lipoblastomas. A similar der(8) was present in the only other published lipoblastoma karyotype, but this der(8) has not been reported in lipomas, liposarcomas, or nonadipose solid tumors. We investigated the potential specificity of der(8)(pter→q13::q24.1→qter) by karyotyping an unselected series of nonlipoblastoma adipose tumors in children and young adults. The series included 14 lipomas, 2 atypical lipomas (“well-differentiated liposarcomas”), and 2 angiomyolipomas; der(8) was not found in any tumor from this series. Three lipomas, however, contained rearrangements in the region of chromosome band 12q14, as has been described frequently in adult lipomas. Because clinical features in lipoblastoma can mimic those in liposarcoma, recognition of der(8)(pter→q13::q24.1→qter) is of potential diagnostic relevance. © 1993 Wiley-Liss, Inc. 相似文献
958.
Relevance of genetic counselling in couples prior to intracytoplasmic sperm injection 总被引:2,自引:8,他引:2
Pauer HU; Hinney B; Michelmann HW; Krasemann EW; Zoll B; Engel W 《Human reproduction (Oxford, England)》1997,12(9):1909-1912
Since the first reports of successful pregnancies after treatment with
intracytoplasmic sperm injection (ICSI) in humans numerous attempts have
been made to assess the genetic risks of this highly invasive technique.
During the study period (February 1995-November 96), 142 couples were
referred to our genetic counselling unit prior to ICSI. In three couples,
genetic counselling revealed a high recurrence risk for a monogenic disease
(myotonic dystrophy, hereditary ataxia and polycystic kidney disease). In
nine out of 128 men (7%) an abnormal karyotype was identified, including
three Robertsonian translocations, two reciprocal translocations, three sex
chromosome aberrations and one case with centric fission of chromosome no.
7. A total of 14 men refused chromosomal analysis. Only one of the 122
women examined had an abnormal karyotype (47, XXX). Five out of six men
with congenital bilateral absence of the vas deferens (CBAVD) had at least
one mutation in the cystic fibrosis transmembrane conductance regulator
(CFTR) gene. Three had mutations in both CFTR alleles, including one case
in which the second mutation was the 5T allele. One patient with CBAVD and
a single Delta F508 CFTR mutation also had left renal agenesis. In
conclusion, we strongly recommend that genetic counselling, chromosomal
analysis and, in the case of CBAVD, screening for CFTR mutations should be
offered to all couples with a diagnosis of male or idiopathic infertility.
相似文献
959.
960.
M. Weis V. Sommer F. G. Zöllner C. Hagelstein K. Zahn T. Schaible S. O. Schoenberg K. W. Neff 《European radiology》2016,26(12):4231-4238