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61.
62.
Detecting pre-ovulatory luteinizing hormone surges in urine 总被引:2,自引:1,他引:2
Kesner JS; Knecht EA; Krieg EF Jr; Wilcox AJ; O'Connor JF 《Human reproduction (Oxford, England)》1998,13(1):15-21
The study objectives were to determine (i) if pre-ovulatory luteinizing
hormone (LH) surges, undetected in urine by two immunoradiometric assays
(IRMA), were detectable by an ultrasensitive immunofluorometric assay
(IFMA) and (ii) the influence of creatinine adjustment on the detection and
timing of the urinary LH surges. Daily urine specimens were contributed by
healthy 25-36 year old volunteers during 14 ovulatory menstrual cycles for
an epidemiological study conducted in 1983-1985. Specimens were selected as
having been previously assayed by two IRMA without consistently detecting
LH surges. These urine specimens were remeasured using an IFMA and adjusted
for creatinine concentration. IFMA measurements revealed unambiguous LH
surges in all cycles. Adjusting IRMA urinary LH values for creatinine
concentrations revealed previously undetected LH surges in four of eight
cycles. Creatinine adjustment also altered the timing of IRMA and IFMA LH
surges by 1-5 days. These results demonstrate an IFMA that detects pre-
ovulatory LH surges in unpreserved, frozen urine from cycles where such
surges were previously undetectable. Further, creatinine adjustment can
markedly affect detection and timing of the onset and peak of the urinary
LH surge. While our analysis suggests that this adjustment improves the
validity of the LH measure, this requires further investigation.
相似文献
63.
Analysis of the steroidogenic acute regulatory protein (StAR) gene in Japanese patients with congenital lipoid adrenal hyperplasia 总被引:1,自引:0,他引:1
Nakae J; Tajima T; Sugawara T; Arakane F; Hanaki K; Hotsubo T; Igarashi N; Igarashi Y; Ishii T; Koda N; Kondo T; Kohno H; Nakagawa Y; Tachibana K; Takeshima Y; Tsubouchi K; Strauss JF rd; Fujieda K 《Human molecular genetics》1997,6(4):571-576
Genomic DNA from 19 Japanese patients with congenital lipoid adrenal
hyperplasia (lipoid CAH) representing 16 different families was examined to
identify the genetic alterations of steroidogenic acute regulatory protein
(StAR). Ten of 19 patients had a 46,XX karyotype and nine had a 46,XY
karyotype. Six of the 46,XX patients have experienced spontaneous pubertal
changes including breast development and irregular menstruation whereas
none of the 46,XY subjects displayed pubertal changes. Eight different
mutations were identified. Sixteen patients were either homozygotes or
compound heterozygotes for the Q258X mutation. The seven other mutations
identified were 189delG, 246insG, 564del13bp, 838delA, Q212X, A218V and
M225T. The 189delG, 246insG, 546del13bp and Q212X mutants encode truncated
proteins. COS-1 cells transfected with expression vectors encoding cDNAs
for the mutant StAR proteins which affect the C-terminus, 838delA, A218V
and Q258X, exhibited no steroidogenesis enhancing activity. However, the
M225T mutant retained some steroidogenic activity. The patient with the
M225T mutation had late onset of this disorder and some capacity to secrete
testosterone in response to hCG. These findings suggest: (i) that the Q258X
mutation can be used as a genetic marker for the screening of Japanese for
lipoid CAH, (ii) that the C-terminus of StAR plays an important role in the
protein's activity and (iii) that there are differences in the extent of
functional impairment of the testis and ovaries in lipoid CAH.
相似文献
64.
Mercan R; Mayer JF; Walker D; Jones S; Oehninger S; Toner JP; Muasher SJ 《Human reproduction (Oxford, England)》1997,12(9):1886-1889
The aim of this study was to compare the efficacy of pure follicle
stimulating hormone (FSH) with that of FSH/human menopausal gonadotrophin
(HMG) combination in downregulated cycles. A total of 357 patients was
evaluated retrospectively. Sixty percent of patients in the FSH group and
55% in the FSH/HMG group were new; the others were repeat patients.
Ovulation was suppressed with leuprolide acetate in all patients, followed
by either FSH (n = 218) or FSH/HMG (n = 119). There was no difference in
patients' age, infertility factors, number of ampoules used, length of
stimulation, oestradiol levels on day of human chorionic gonadotrophin
(HCG) administration, number of oocytes recovered or the number of embryos
transferred. Also, nuclear maturity at aspiration and fertilization rates
were not different between the two groups. FSH stimulation resulted in a
significantly higher percentage of mature oocytes that showed the typical
'mature' morphological characteristics (P < 0.0001). The clinical
pregnancy rates per transfer were 40 and 28% in patients stimulated with
pure FSH and FSH/HMG respectively (P < 0.05). The significantly higher
number of immature oocytes matured in vitro in the FSH/HMG group (P =
0.001) suggests a possible effect on in-vitro maturation, due to
luteinizing hormone present in HMG. The difference in mature oocyte quality
may be an important determinant in the higher pregnancy rates for the FSH-
stimulated patients.
相似文献
65.
66.
The nonstructural proteins of Sindbis virus as studied with an antibody specific for the C terminus of the nonstructural readthrough polyprotein 总被引:7,自引:0,他引:7
A dodecapeptide containing the sequence of the C terminus of the nonstructural polyprotein of Sindbis virus has been synthesized and used to immunize rabbits. The antisera obtained precipitated polypeptides from cells infected with the HR strains of Sindbis or with temperature-sensitive mutants ts11 or ts18. Four different polypeptides, having apparent molecular weights of approximately 250,000, 220,000, 155,000, and 72,000, were immunoprecipitated by the antipeptide antiserum. The largest of these polypeptides is sufficiently large to represent a polyprotein translated from the entire nonstructural region of the genome. These data suggest that nsP4 of molecular weight 72,000 is produced by translation of the entire nonstructural region of the genome, which requires readthrough of an opal termination codon immediately upstream of nsP4, followed by post-translational cleavage of this polyprotein. The amounts of nsP4 and its precursors found in infected cells are small relative to the amounts of other nonstructural proteins present, as would be expected if readthrough of a termination codon is required. In addition, the relative amounts of nsP4 and of its precursors differ in HR-infected or ts mutant-infected cells and differ with temperature of infection, suggesting that temperature of infection or ts lesions affect translation and processing of the precursor polyprotein. 相似文献
67.
68.
Complete nucleotide sequence of the genomic RNA of Sindbis virus 总被引:82,自引:0,他引:82
The entire nucleotide sequence of the genomic RNA of the type virus of the alphavirus genus, Sindbis virus, has been determined. The genome is 11,703 nucleotides in length, exclusive of the 5' cap and the 3'-terminal poly(A) tract. After the 5'-terminal cap there are 59 nucleotides of 5' nontranslated nucleic acid followed by a reading frame of 7539 nucleotides that encodes the nonstructural polypeptides and which is open except for a single opal termination codon. Following 48 untranslated bases located in the junction region which separates the nonstructural and structural protein coding sequences, there is an open reading frame 3735 nucleotides long that encodes the structural proteins. Finally, the 3' untranslated region is 322 nucleotides long. The nonstructural proteins are translated from the genomic RNA as two polyprotein precursors. The first is 1896 amino acids in length and terminates at an opal codon at position 1897. This polyprotein is processed to produce three polypeptides called nsP1, nsP2, and nsP3. Sites of post-translational cleavage to produce these three proteins have been tentatively located using available N-terminal amino acid sequence data. In both cases cleavage probably occurs between the two alanine residues in the sequence Gly-Ala-Ala. The fourth nonstructural protein, nsP4, is produced when readthrough of the opal codon produces a second polyprotein precursor of length 2513 amino acids, which is also cleaved posttranslationally. The structural proteins are translated from a subgenomic message which begins at nucleotide 7598, is 4106 nucleotides in length (exclusive of the poly(A) tract), and is coterminal with the 3' end of the genomic RNA. The structural proteins are also translated as a polyprotein precursor which is cleaved to produce a nucleocapsid protein and two integral membrane glycoproteins as well as two small peptides not present in the mature virion. A replication strategy for Sindbis virus based upon the complete nucleotide sequence, as well as prior data, is presented. 相似文献
69.
J. C. Rüegg C. Zeugner J. D. Strauss R. J. Paul B. Kemp M. Chem A. -Y. Li D. J. Hartshorne 《Pflügers Archiv : European journal of physiology》1989,414(3):282-285
During smooth muscle activation the calcium calmodulin complex interacts with myosin light chain kinase (MLCK) whereby activating it. A synthetic peptide analogue (RS20) corresponding to the calmodulin recognition sequence of MLCK has been synthesized and previously found to inhibit the calmodulin stimulated light chain kinase activity. Here we studied the effect of this peptide on skinned fibers from guinea pig taenia coli. Maximal contractions induced by 30 M Ca2+ at 0.1 M calmodulin could be completely relaxed by the peptide at 1 M. The inhibitory effect was accompanied by partial dephosphorylation only of the regulatory myosin light chain. Relaxation could be reversed by addition of calmodulin which also increased the extent of light chain phosphorylation.The calmodulin concentration required for reversing the inhibition depended on the concentration of the inhibitory peptide suggesting that the peptide competed with MLCK for the calmodulin binding site. As the calcium-calmodulin-peptide mixture constitutes a calmodulin buffer, our results suggest, that the peptide is a calmodulin antagonist unique in terms of its potency and that less than nanomolar concentrations of free calmodulin may be required for inducing smooth muscle contractions. 相似文献
70.
Role of the Phagocyte in Host-Parasite Interactions XXIV. Aldehyde Generation by the Myeloperoxidase-H(2)O(2)-Chloride Antimicrobial System: a Possible In Vivo Mechanism of Action 总被引:6,自引:6,他引:6
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Myeloperoxidase (MPO), H2O2, and chloride ions in the presence of bacteria form aldehydes and are bactericidal. The use of heat-inactivated MPO prevented both killing and aldehyde generation. Decarboxylation and deamination of carboxyl and amino group substrates arising from the bacterial surface may participate in the reaction which yields aldehydes. Bacterial contact was essential for killing. Decarboxylation and bactericidal activities were noted when physiological concentrations of chloride were used. When MPO was replaced with horseradish peroxidase (HPO) in the chloride medium, decarboxylation and bactericidal activities were no longer noted. In contrast, iodide functioned in the antimicrobial system with either MPO or HPO. The iodide concentrations required were at least sixfold greater than circulating blood iodide levels. Moreover, decarboxylation did not occur in the presence of iodide with either enzyme. Thus, both halides function in the MPO-H2O2 system but by different mechanisms. It is likely that in vivo under most conditions chloride is the functional halide and that generation of aldehydes is the mechanism responsible for the antimicrobial activity of the MPO-H2O2-chloride system. 相似文献