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101.
Johanna C Dekkers Marieke F van Wier Ingrid JM Hendriksen Jos WR Twisk Willem van Mechelen 《BMC medical research methodology》2008,8(1):69
Background
In population studies, body mass index (BMI) is generally calculated from self-reported body weight and height. The self-report of these anthropometrics is known to be biased, resulting in a misclassification of BMI status. The aim of our study is to evaluate the accuracy of self-reported weight, height and waist circumference among a Dutch overweight (Body Mass Index [BMI] ≥ 25 kg/m2) working population, and to determine to what extent the accuracy was moderated by sex, age, BMI, socio-economic status (SES) and health-related factors. 相似文献102.
Matson PL; Graefling J; Junk SM; Yovich JL; Edirisinghe WR 《Human reproduction (Oxford, England)》1997,12(7):1550-1553
Mouse oocytes and embryos were obtained following ovulation induction of
(C57B16 x CBA) F1 animals. Zonae pellucidae were exposed to alpha-
chymotrypsin in phosphate-buffered medium (PB1) supplemented with 3 mg/ml
bovine serum albumin upon a heated stage (37 degrees C) and were observed
constantly through an inverted microscope. The endpoint of the bioassay was
the limits of the zona no longer being seen clearly at x 200 magnification,
and the time taken for each zona to dissolve was recorded. A dose-dependent
response in dissolution time was clearly seen, with 1% alpha-chymotrypsin
being chosen as the routine working solution. Cryopreservation of 2-cell
mouse embryos using propanediol did not cause zona hardening but induced a
small and significant softening, as gauged by the time taken for zona
dissolution (2181 +/- 167 versus 1864 +/- 82 s). Zona hardening was not
suspected to occur after the freezing of human embryos as there was no
difference in implantation rates per embryo for in-vitro fertilization
(IVF) and intracytoplasmic sperm injection (ICSI) treatment cycles between
fresh [IVF: 63/644 (9.7%); ICSI: 51/330 (15.5%)] and frozen embryos [IVF:
36/458 (7.9%); ICSI: 18/112 (16.1%)]. Conversely, significant hardening of
the zonae of mature oocytes was seen following cryopreservation (747 +/-
393 s) compared with freshly ovulated oocytes (151 +/- 68 s). It is
concluded that (i) the freezing of murine oocytes with propanediol results
in zona hardening, implying a possible benefit of ICSI after the
cryopreservation of human oocytes, and (ii) the cryopreservation of embryos
is not associated with zona hardening or reduced implantation, making
microdissection of the zona in such cases generally unwarranted.
相似文献
103.
The extensive heterogeneity of the gonadotrophin hormones, follicle
stimulating hormone (FSH) and luteinizing hormone (LH), is due primarily to
the heterogeneous nature of their carbohydrate side- chains, in particular
sialic acid residues. In this review, we discuss the role of carbohydrate
chains in receptor binding and activation, biological activity, and
metabolic half-life. The synthesis and secretion of the various glycoforms
of both FSH and LH appear to be under endocrine control with
gonadotrophin-releasing hormone (GnRH), oestradiol and testosterone playing
important roles. Evidence for different glycoforms having variable
biopotency or different encoded functions is increasing, and the production
and secretion of more or less acidic gonadotrophin species in different
physiological states may represent an important mechanism whereby the
pituitary regulates gonadal cell and organ function. This has potential
importance for the development of new pharmaceutical reagents and new
therapeutic regimens in assisted reproduction. It is envisaged that the use
of existing and new forms of FSH/LH will allow patients to be treated in a
more controlled and physiological manner, with treatment regimens
individualized to the needs of the patient.
相似文献
104.
Virus-induced cytokines regulate circulating lymphocyte levels during primary SIV infections 总被引:1,自引:0,他引:1
Rosenberg YJ; Cafaro A; Brennan T; Greenhouse JG; Villinger F; Ansari AA; Brown C; McKinnon K; Bellah S; Yalley-Ogunro J; Elkins WR; Gartner S; Lewis MG 《International immunology》1997,9(5):703-712
Decline in blood CD4+ lymphocytes during primary symptomatic infections
with HIV is usually attributed to viral killing, and has not been
considered in terms of altered lymphocyte migration and sequestration. We
therefore sought to examine whether CD4+ cell loss from blood of macaques
undergoing an acute primary SIV infection might be due to increased
synthesis of cytokines, known to profoundly affect lymphocyte trafficking,
rather than to direct lymphocyte destruction by virus. The findings
indicate that rapid lymphocyte depletion following acute infection is not
selective for CD4+ cells, correlates precisely with increased plasma
IFN-gamma and tumor necrosis factor-alpha levels, and is reversible.
CD4/CD8 ratios in lymph nodes with high viral burdens remain relatively
unchanged despite lymphocyte loss from blood. Levels of cytokine mRNA
measured in lymphoid organs reflect neither cytokine plasma levels nor
their potential to induce sequestration. These results support a model of
cytokine-induced lymphocyte extravasation to account for the acute
HIV/SIV-induced CD4+ cell lymphopenia and raise questions regarding the
extent to which altered lymphocyte migration plays a role in the gradual
CD4+ cell depletion throughout infection.
相似文献
105.
Trinucleotide expansion mutations in the cartilage oligomeric matrix protein (COMP) gene 总被引:6,自引:1,他引:5
Pseudoachondroplasia (PSACH) and multiple epiphyseal dysplasia (MED) are
two human autosomal dominant skeletal dysplasias characterized by variable
short stature, joint laxity and early-onset degenerative joint disease.
Both disorders can result from mut-ations in the gene for cartilage
oligomeric matrix protein (COMP), an extracellular matrix glycoprotein.
About one-third of PSACH cases result from heterozygosity for deletion of
one codon within a very short triplet repeat, (GAC)5, which encodes five
consecutive aspartic acid residues within the calmodulin-like region of the
COMP protein. We have identified two expansion mut-ations in this repeat:
an MED patient carrying a (GAC)6allele and a PSACH patient carrying a
(GAC)7allele. These are among the shortest disease-causing triplet repeat
expansion mutations described thus far, and are the first identified in a
GAC repeat. A unique feature of this sequence is that expansion as well as
shortening of the repeat can cause the same disease. In cartilage, both
patients have rough endoplasmic reticulum inclusions in chondrocytes. The
inclusions are also present in tendon tissue and can be reproduced in
cultured tendon cells, suggesting that the pathophysiology of disease is
similar in both cartilage and tendon.
相似文献
106.
Autologous bone marrow transplantation is potentially curative in the treatment of acute leukemia if residual leukemic cells in the marrow can be eliminated prior to transplantation. We studied the purging effects of a synthetic alkyl-lysophospholipid (ALP) on marrow containing leukemic cells from a transplantable myelomonocytic leukemia (WEHI-3B) in BALB/c mice. Simulated remission bone marrow containing 2% leukemic cells treated in vitro with 20 and 100 micrograms/mL of ET-18- OCH3 (1-octadecyl-2-methyl-sn-glycerol-3-phosphocholine) significantly prolonged survival of lethally irradiated transplanted recipients. At a dose of 100 micrograms/mL, 88% of the mice survived for the duration of the experiment (approximately five months). Autopsies showed that 25% of these survivors had microscopic evidence of leukemia. Thus, in vitro treatment of marrow eliminated leukemic blasts and spared sufficient normal stem cells to allow hematologic reconstitution. The effect of ET- 18-OCH3 is not entirely selective for leukemic cells. A spleen colony assay showed that ALP has some cytotoxic effect on normal hematopoietic stem cells. 相似文献
107.
Detection of pulmonary nodules using spin-echo magnetic resonance (MR) imaging was compared with detection using computed tomography (CT). Of the 25 patients studied independently by two radiologists, no lung nodules were detected in 11 (CT or MR), ten had a single nodule, and four had multiple nodules. The lesions not seen using CT or MR were less than 1.3 cm in diameter. The greater spatial resolution of CT enabled better detection of nodules close to the diaphragm, the pleura, or to each other, whereas the better contrast resolution of MR enabled the detection of several nodules close to blood vessels. With MR, nodules were best seen on images with long repetition times (2.0 sec). Most pulmonary nodules are seen using both CT and MR. CT generally enables the detection of more small nodules than MR does, and some low-density nodules near blood vessels are better displayed using MR. 相似文献
108.
109.
We describe a new pyeloureteral drainage catheter that can be used for both genitourinary tract stenting and drainage, as well as tamponade of bleeding from the renal parenchyma or subcutaneous tissue. Primary indications for the use of this catheter and recommendations on insertion techniques are presented. With the exception of one case of minor kinking of the catheter, we have had no complications or failures with this catheter. While insertion through an unprotected tissue track is somewhat difficult, we have had good success introducing the catheter through a 24-F or larger Teflon working sheath. The catheter has excellent patient retention properties. It can be converted from external to internal drainage or vice versa simply and quickly on the ward. 相似文献
110.