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61.
62.
Layman LC; Edwards JL; Osborne WE; Peak DB; Gallup DG; Tho SP; Reindollar RH; Roach DJ; McDonough PG; Lanclos KD 《Molecular human reproduction》1997,3(4):315-320
Women with recurrent abortion, primary unexplained infertility, and
gestational trophoblastic neoplasia (GTN) manifest disordered human
chorionic gonadotrophin (HCG) secretion. Mutations in the HCG
beta/luteinizing hormone (LH) beta gene complex could cause aberrant HCG
production in these disorders. The purpose of this study was to determine
whether HCG beta gene deletions occur in women with recurrent abortion or
primary unexplained infertility, and whether HCG beta gene duplications are
present in women with GTN. DNA was extracted from 10 patients with
unexplained recurrent abortion, 10 patients with unexplained primary
infertility, 12 patients with GTN, three partners of women with GTN, and 30
controls. Southern blots were constructed and hybridized with DNA probes
for HCG beta-5 and the LH beta gene. No gene deletions were identified in
patients with recurrent abortion or primary unexplained infertility.
Likewise, no gene duplications were identified in women with GTN. A
previously described Mbol restriction fragment length polymorphism (RFLP)
was identified in both patients and controls. A new Pstl RFLP was also
characterized, but was present in patients and controls.
Deletion/duplication mutations in the HCG beta/LH beta gene complex do not
appear to be common causes of aberrant HCG production in humans with these
disorders.
相似文献
63.
Strom TM; Hortnagel K; Hofmann S; Gekeler F; Scharfe C; Rabl W; Gerbitz KD; Meitinger T 《Human molecular genetics》1998,7(13):2021-2028
Wolfram syndrome is an autosomal recessive disorder characterized by
juvenile diabetes mellitus, diabetes insipidus, optic atrophy and a number
of neurological symptoms including deafness, ataxia and peripheral
neuropathy. Mitochondrial DNA deletions have been described in a few
patients and a locus has been mapped to 4p16 by linkage analysis.
Susceptibility to psychiatric illness is reported to be high in affected
individuals and increased in heterozygous carriers in Wolfram syndrome
families. We screened four candidate genes in a refined critical linkage
interval covered by an unfinished genomic sequence of 600 kb. One of these
genes, subsequently named wolframin, codes for a predicted transmembrane
protein which was expressed in various tissues, including brain and
pancreas, and carried loss-of- function mutations in both alleles in
Wolfram syndrome patients.
相似文献
64.
65.
Inhibition of nitric oxide synthesis reveals non-cholinergic excitatory neurotransmission in the canine proximal colon. 总被引:1,自引:1,他引:0 下载免费PDF全文
1. Neuromuscular transmission in the circular muscle of the canine proximal colon was examined, in the presence and absence of nitric oxide synthase inhibitors, by use of mechanical and intracellular microelectrode recording techniques. 2. Electrical field stimulation (EFS; 0.1-20 HZ) produced frequency-dependent contractions of circular muscle strips which reached a maximum at 15 Hz. These responses were enhanced by NG-monomethyl-L-arginine (L-NMMA; 300 microM) and reduced by atropine (1 microM). The effects of L-NMMA were reversed by L-arginine (3 mM). All responses to EFS were abolished by tetrodotoxin (1 microM). 3. In the presence of atropine, phentolamine and propranolol (all at 1 microM; 'non-adrenergic, non-cholingergic (NANC) conditions'), EFS evoked frequency-dependent inhibition of phasic contractions which reached a maximum at 5 Hz. At higher frequencies of EFS, inhibition diminished, and these responses were followed by post-stimulus excitation. 4. Under NANC conditions and in the presence of L-NG-nitroarginine methyl ester (L-NAME; 200 microM), EFS evoked contractions at frequencies of 5 Hz or greater. These contractions were reduced by co-incubation with L-arginine (2 mM) and abolished by tetrodotoxin (1 microM). 5. In the presence of atropine (1 microM), EFS (5-20 Hz) caused frequency-dependent inhibition of electrical slow waves. In the presence of L-NAME (100 microM) and atropine, the inhibitory response to EFS was abolished and an increase in slow wave duration was seen at stimulation frequencies greater than 5 Hz. The effects of EFS on slow wave duration were abolished by tetrodotoxin (1 microM).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
66.
Suppression of peroxisomal membrane protein defects by peroxisomal ATP binding cassette (ABC) proteins 总被引:8,自引:4,他引:4
Braiterman LT; Zheng S; Watkins PA; Geraghty MT; Johnson G; McGuinness MC; Moser AB; Smith KD 《Human molecular genetics》1998,7(2):239-247
X-Linked adrenoleukodystrophy (X-ALD) is a neurodegenerative disorder
characterized by reduced peroxisomal very long chain fatty acid (VLCFA)
beta-oxidation. The X - ALD gene product (ALDP) is a peroxisomal
transmembrane protein with an ATP binding cassette (ABC). ALDP and three
other ABC proteins (PMP70, ALDR, P70R) localize to the peroxisomal
membrane. The function of this family of peroxisomal membrane proteins is
unknown. We used complementation studies to begin analysis of their role in
VLCFA beta-oxidation and on the peroxisomal membrane. Expression of either
ALDP or PMP70 restores VLCFA beta- oxidation in X-ALD fibroblasts,
indicating overlapping functions. Their expression also restores peroxisome
biogenesis in cells that are deficient in the peroxisomal membrane protein
Pex2p. Thus it is likely that complex protein interactions are involved in
the function and biogenesis of peroxisomal membranes that may contribute to
disease heterogeneity.
相似文献
67.
Steinsapir KD Goldberg RA Sinha S Hovda DA 《Journal of the peripheral nervous system : JPNS》2002,7(2):136-136
The excitability of human axons can be studied reliably using the technique of threshold tracking, which allows the strength of a test stimulus to be adjusted by computer to activate a defined fraction of the maximal nerve or muscle action potential. The stimulus current that just evokes the target response is considered the 'threshold' for that response. More useful than the resting threshold are other indices of axonal excitability derived from pairs of threshold measurements, such as refractoriness, supernormality, strength-duration time constant and 'threshold electrotonus' (i.e. the changes in threshold produced by long-lasting depolarizing or hyperpolarizing current pulses). Each of these measurements depends on membrane potential and on other biophysical properties of the axons. Together they can provide new information about the pathophysiology underlying abnormalities in excitability in neuropathy. 相似文献
68.
Pseudomembranous colitis: CT evaluation of 26 cases 总被引:3,自引:0,他引:3
Fishman EK; Kavuru M; Jones B; Kuhlman JE; Merine DS; Lillimoe KD; Siegelman SS 《Radiology》1991,180(1):57
69.
70.
Excitatory junctional potentials (EJPs) elicited with brief duration (10 s) electrical field stimulation of guinea-pig mesenteric arteries were nearly abolished at all frequencies by pyridoxal-phosphate-6-azophenyl-2',4'-disulfonic acid (PPADS, 30 microM) but persisted following reserpinization. Suramin (100 microM) enhanced EJPs at 0.2-0.5 Hz responses and reduced them at 2-32 Hz. Phentolamine (1 microM) and yohimbine (0.1 microM) enhanced EJPs at 0.2-8 Hz but not at 16-32 Hz. Oxymetazoline (0.3 microM) reduced EJPs at 0.2-0.5 Hz but not at 1-32 Hz. Following reserpinization, EJPs were enhanced at 0.2-2 Hz but not at 4-32 Hz. Clonidine (0.1 microM) was without effect at all frequencies in control arteries but reduced EJPs at 0.2-2 Hz in reserpine-treated arteries. In conclusion, pre-junctional alpha(2)-adrenoceptors modulate ATP release during low frequency, brief duration sympathetic nerve stimulation. 相似文献