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991.
Tyson J; Tranebjaerg L; Bellman S; Wren C; Taylor JF; Bathen J; Aslaksen B; Sorland SJ; Lund O; Malcolm S; Pembrey M; Bhattacharya S; Bitner-Glindzicz M 《Human molecular genetics》1997,6(12):2179-2185
The Jervell and Lange-Nielsen syndrome (JLNS) comprises profound congenital
sensorineural deafness associated with syncopal episodes. These are caused
by ventricular arrhythmias secondary to abnormal repolarisation, manifested
by a prolonged QT interval on the electrocardiogram. Recently, in families
with JLNS, Neyroud et al. reported homozygosity for a single mutation in
KVLQT1 , a gene which has previously been shown to be mutated in families
with dominantly inherited isolated long QT syndrome [Neyroud et al . (1997)
Nature Genet ., 15, 186-189]. We have analysed a group of families with
JLNS and shown that the majority are consistent with mutation at this
locus: five families of differing ethnic backgrounds were homozygous by
descent for markers close to the KVLQT1 gene and a further three families
from the same geographical region were shown to be homozygous for a common
haplotype and to have the same homozygous mutation of the KVLQT1 gene.
However, analysis of a single small consanguineous family excluded linkage
to the KVLQT1 gene, establishing genetic heterogeneity in JLNS. The
affected children in this family were homozygous by descent for markers on
chromosome 21, in a region containing the gene IsK . This codes for a
transmembrane protein known to associate with KVLQT1 to form the slow
component of the delayed rectifier potassium channel. Sequencing of the
affected boys showed a homozygous mutation, demonstrating that mutation in
the IsK gene may be a rare cause of JLNS and that an indistinguishable
phenotype can arise from mutations in either of the two interacting
molecules.
相似文献
992.
SJ Duckett 《Australia and New Zealand Health Policy》2005,2(1):14
There are recognised shortages in most health professions in Australia. This is evidence that previous attempts at health workforce planning have failed. This paper argues that one reason for such failure is the lack of appropriate structures for health workforce planning. It also suggests that Australia needs to move beyond planning for particular professions and that health workforce planning needs to be based on identifying skill shortages as much as shortages in particular named professionals.The paper proposes specific policy suggestions to facilitate workforce flexibility and health workforce planning in Australia. 相似文献
993.
Effect of antiphospholipid antibodies in women undergoing in-vitro fertilization: role of heparin and aspirin 总被引:3,自引:4,他引:3
Kutteh WH; Yetman DL; Chantilis SJ; Crain J 《Human reproduction (Oxford, England)》1997,12(6):1171-1175
To describe the prevalence of antiphospholipid antibodies in women
undergoing in-vitro fertilization (IVF) and to determine if heparin and
aspirin affect implantation rates, 191 women with a history of infertility
undergoing IVF were prospectively tested for antiphospholipid antibodies.
This was a two-centre, non-randomized comparison of women with positive
antiphospholipid antibodies receiving heparin and aspirin versus standard
treatment. An enzyme-linked immunosorbent assay, with referenced standards
and known positive and negative sera on each plate, was utilized to measure
antibodies to cardiolipin, phosphatidylinositol, phosphatidylglycerol,
phosphatidylserine and phosphatidylethanolamine. Statistical analyses of
results included analysis of variance and Fisher's two-tailed exact test.
Antiphospholipid antibodies were detected in 18.8% of patients undergoing
IVF compared with only 5.5% in the 200 normal controls, 26% in 200 women
with recurrent pregnancy loss, and 32% in 200 women with systemic lupus
erythematosus. In conclusion, antiphospholipid antibodies were found more
frequently in women undergoing IVF than in the normal control population.
Although implantation rates appeared higher in the group of women treated
with heparin and aspirin, no statistically significant differences were
detected in implantation, pregnancy and ongoing pregnancy rates between
those who received standard therapy and those treated with heparin and
aspirin.
相似文献
994.
Glycoform composition of serum gonadotrophins through the normal menstrual cycle and in the post-menopausal state 总被引:7,自引:2,他引:7
Anobile CJ; Talbot JA; McCann SJ; Padmanabhan V; Robertson WR 《Molecular human reproduction》1998,4(7):631-639
The heterogeneity of follicle stimulating hormone (FSH) and luteinizing
hormone (LH) was investigated in five women aged 29.4 +/- 3.2 years (mean
+/- SD) throughout their menstrual cycles and in five post- menopausal
women aged 53.8 +/- 5.6 years. Chromatofocusing (pH range 7- 4) revealed
menstrual cycle stage- and postmenopausal-related differences in the serum
gonadotrophin charge. There were differences in the proportion of FSH with
an isoelectric point (pl) > 4.3 across phases of the menstrual cycle (P
= 0.019): midcycle (MC) 50%; early to mid-follicular (EMF) 36%; late
follicular (LF) 37%, luteal (L) 29% and following the menopause (PM) 17%.
There was no significant difference in the proportion of LH with pl >
6.55 between midcycle (53%) and EMF, LF or L phases (36, 43 and 32%
respectively); although all were greater than that found in the menopause
(13%). Concanavalin A chromatography revealed less (P < 0.005) complex
FSH and LH glycoforms at midcycle (63 and 13%) than in the EMF, LF and L
phases (90 and 18; 90 and 20 and 93 and 24% respectively). Menopausal
gonadotrophins were least complex (FSH 34%, LH 4%). There was a direct
relationship between serum FSH and FSH pl/complexity, and less acidic FSH
was associated with reduced FSH complexity. Increased oestradiol was
associated with basic FSH isoforms during the menstrual cycle and reduced
follicular phase FSH complexity. We conclude that changes in gonadotrophin
glycoforms occur through the menstrual cycle which are related to changes
in the prevailing steroid environment. Following the menopause oestrogenic
loss resulted in acidic, relatively simple glycoforms.
相似文献
995.
Uterine leiomyomas reduce the efficacy of assisted reproduction cycles: results of a matched follow-up study 总被引:7,自引:8,他引:7
Stovall DW; Parrish SB; Van Voorhis BJ; Hahn SJ; Sparks AE; Syrop CH 《Human reproduction (Oxford, England)》1998,13(1):192-197
A matched follow-up study design was used to test the hypothesis that
pregnancy rates following assisted reproduction procedures do not differ
between women with or without intramural or sub-serosal uterine leiomyomas.
Women undergoing their first in-vitro fertilization (IVF)- embryo transfer
or zygote intra-Fallopian transfer (ZIFT) cycle between January 1993 and
June 1995 were included. Cases (women with leiomyomas) were matched 1:1
with the next consecutive control (women without leiomyomas) according to
age, number of embryos transferred, embryo grade, and the route of embryo
transfer (uterine or Fallopian). Assisted reproduction cycles were
performed in an identical manner, independent of the presence or absence of
uterine leiomyomas. The main outcomes measured were clinical pregnancy and
delivery rates. A total of 182 cycles was evaluated. Of the 91 assisted
reproduction cycles performed in the leiomyoma group, there were 34
clinical pregnancies (37%) and 30 deliveries (33%). Of the 91 assisted
reproduction cycles in the control group, there were 48 clinical
pregnancies (53%) and 44 deliveries (48%). The Mantel-Haenszel estimate of
relative risk indicated that the presence of a uterine leiomyoma
significantly reduced the chance for a clinical pregnancy or delivery.
These findings suggest that leiomyomas are associated with a reduction in
the efficacy of assisted reproduction cycles.
相似文献
996.
Bcl-2 functions as a death repressor molecule in an evolutionarily conserved cell death pathway. To further explore the role of Bcl-2 in development, we assessed its pattern of expression during murine embryogenesis. Immunohistochemical analysis demonstrates that Bcl-2 is widely expressed early in mouse fetal development in tissues derived from all three germ layers and that this expression becomes restricted with maturation. Within epithelium, the E12.5 lung bud demonstrates a proximal to distal gradient of Bcl-2 expression which is enhanced by E18.5. Bcl-2 is expressed throughout the intestinal epithelium through E14.5, but by E18.5 only cells in the crypts and lower villi express Bcl-2. In the mesoderm-derived kidney, Bcl-2 is expressed in both the ureteric bud and metanephric cap tissue at E12.5. Tubular structures also express Bcl-2, although overall levels drop as the kidney matures. Retinal neuroepithelial cells uniformly express Bcl-2 until cells begin to differentiate and then display the topographic distribution maintained into adulthood. The developing limb provides a clear example where Bcl-2 is restricted to zones of cell survival; Bcl-2 is expressed in the digital zones but not in the interdigital zones of cell death. The wide distribution of Bcl-2 in the developing mouse suggests that many immature cells require a death repressor molecule or that Bcl-2 may have roles beyond regulating developmental cell death. 相似文献
997.
Characterisation of renal chloride channel, CLCN5, mutations in hypercalciuric nephrolithiasis (kidney stones) disorders 总被引:4,自引:0,他引:4
Lloyd SE; Gunther W; Pearce SH; Thomson A; Bianchi ML; Bosio M; Craig IW; Fisher SE; Scheinman SJ; Wrong O; Jentsch TJ; Thakker RV 《Human molecular genetics》1997,6(8):1233-1239
Mutations of the renal-specific chloride channel (CLCN5) gene, which is
located on chromosome Xp11.22, are associated with hypercalciuric
nephrolithiasis (kidney stones) in the Northern European and Japanese
populations. CLCN5 encodes a 746 amino acid channel (CLC-5) that has
approximately 12 transmembrane domains, and heterologous expression of
wild-type CLC-5 in Xenopus oocytes has yielded outwardly rectifying
chloride currents that were markedly reduced or abolished by these
mutations. In order to assess further the structural and functional
relationships of this recently cloned chloride channel, additional CLCN5
mutations have been identified in five unrelated families with this
disorder. Three of these mutations were missense (G57V, G512R and E527D),
one was a nonsense (R648Stop) and one was an insertion (30:H insertion). In
addition, two of the mutations (30:H insertion and E527D) were demonstrated
to be de novo, and the G57V and E527D mutations were identified in families
of Afro-American and Indian origin, respectively. The G57V and 30:H
insertion mutations represent the first CLCN5 mutations to be identified in
the N-terminus region, and the R648Stop mutation, which has been observed
previously in an unrelated family, suggests that this codon may be
particularly prone to mutations. Heterologous expression of the mutations
resulted in a marked reduction or abolition of the chloride currents,
thereby establishing their functional importance. These results help to
elucidate further the structure-function relationships of this renal
chloride channel.
相似文献
998.
Silber SJ; Nagy Z; Devroey P; Camus M; Van Steirteghem AC 《Human reproduction (Oxford, England)》1997,12(12):2693-2700
Factors other than spermatozoa could be the major determinant of the
success of assisted reproduction treatment in cases of male infertility.
Our aim was to evaluate the effect of the wife's age and ovarian reserve on
assisted reproduction success rates in the most severe type of male
infertility, i.e. azoospermia. A total of 249 consecutive couples suffering
from male infertility caused by azoospermia underwent microsurgical
epididymal sperm aspiration (MESA) or testicular sperm extraction (TESE)
with intracytoplasmic sperm injection (ICSI). Of these men, 186 had
irreparable obstructive azoospermia, and 63 had non-obstructive azoospermia
due to testicular failure. Neither the pathology, the source, the quantity,
nor the quality of spermatozoa had any effect on fertilization or pregnancy
rates. Maternal age and ovarian reserve (number of eggs) had no effect on
fertilization or embryo cleavage, but did dramatically affect the embryo
implantation, pregnancy and delivery rates. Wives of azoospermic men who
were in their 20s had a 46% live delivery rate per cycle, wives aged 30-36
years had a 34% live delivery rate per cycle, wives aged 37- 39 years had a
13% live delivery rate per cycle, and wives > or = 40 years had only a
4% live delivery rate per cycle. The number of eggs retrieved also affected
pregnancy and delivery rate, but to a lesser extent than age. In virtually
all cases of obstructive azoospermia, and in 62% of cases with
non-obstructive azoospermia caused by germinal failure, sufficient
spermatozoa could be retrieved to perform ICSI, with normal fertilization
and embryo cleavage. However, the pregnancy rate and the live delivery rate
were dependent strictly on the age of the wife, and on her ovarian reserve.
Unfortunately, exaggerated claims of high pregnancy rates can thus easily
be made by manipulating, in a very simple way, selection for female
factors.
相似文献
999.
1000.
Two children had pain in one arm, followed by weakness and wasting, after an acute exacerbation of bronchial asthma. Similar cases in which a poliomyelitis-like illness was associated with acute asthma have been reported, but the relationship between the two remains conjectural. 相似文献