Hemoglobin (Hb) solutions can cause vasoconstriction and activation of intravascular coagulation. Because the endothelium plays a major role in the regulation of vascular tone and hemostasis, a study was conducted of human umbilical vein endothelial cells (EC) incubated with various Hbs. Cell injury was evaluated by electron microscopy and the release of lactic dehydrogenase, H2O2, and procoagulant "tissue factor." Cell reaction was assessed by the measurement of 6-keto-prostaglandin F (PGF)1 alpha (metabolite of prostacyclin) and thromboxane B2 (metabolite of thromboxane A2). Incubation with unmodified bovine hemoglobin for 24 h caused no cell injury and a reaction characterized by 48.4 +/- 8.2% increase in 6-keto-PGF1 alpha production, accompanied by 40.2 +/- 9.4% reduction in thromboxane (Tx)B2 (compared with a control group of EC incubated with saline solution). Incubation with a nonpure Hb solution (Hb plus red blood cell membrane aminophospholipids; a-PLs) caused cell injury with significant release of tissue factor, plus a reaction characterized by 97.5 +/- 12.5% increase in TxB2 production accompanied by 25.3 +/- 3% reduction in 6-keto-PGF1 alpha. A second nonpure Hb [Hb plus bacterial environmental endotoxin (E)] caused cell injury, the release of tissue factor, and increased production of both prostaglandins, with greater release of TxB2 (197 +/- 17%) than of 6-keto-PGF1 alpha (112 +/- 8.3%). These data indicate that the endothelium reacts differently to pure and nonpure hemoglobins. The biocompatibility of Hb solutions, with regard to vasoconstriction and activation of intravascular coagulation, depends on the absence of stromal a-PLs and bacterial E. 相似文献
The effects of chronic administration of L-carnitine were evaluated by EMG analysis in 20 uraemic patients undergoing periodical haemodialysis (mean duration of dialysis 34.7 months). No important changes in motor conduction velocity or distal latency of the external popliteal nerve were found after the treatment, while a reduction in the number of polyphasic muscle action potentials was observed. After carnitine administration, an increase of total EMG power was noted and the spectral array showed a progressive shift towards lower frequencies in 8 patients who had shown higher values. These results suggest that carnitine has a prevalent "myotrophic" effect. 相似文献
Journal of Thrombosis and Thrombolysis - rVIII-SingleChain is indicated for treatment and prophylaxis of bleeding in patients with haemophilia A (HA). The safety and efficacy of rVIII-SingleChain... 相似文献
Recent studies have shown that a quadripolar left ventricular (LV) lead can result in low rates of dislocation and phrenic nerve stimulation (PNS) acutely and on medium-term follow-up in cardiac resynchronization therapy (CRT). We evaluated the outcomes of CRT patients in whom a quadripolar LV lead was implanted in our institution.
Methods
We studied 45 consecutive heart failure patients (75 % men; age, 70.3?±?9.0 years) following successful implantation of a quadripolar LV lead. Demographic and clinical data were collected preoperatively, and patients were followed up for 18.9 months.
Results
The implantation success rate was 100 %. Mean overall duration was 100.1?±?34.6 min, and X-ray exposure time was 13.20?±?13.5 min. The most distal effective pacing site was used as the final pacing configuration in all patients. Acute dislodgment requiring reoperation occurred before discharge in three cases (6.6 %). Six patients (13 %) suffered PNS during follow-up; we solved this problem by changing the stimulation vector. Three months after implantation, a mean of six out of ten effective sites (threshold <2.5 V at 1.5 ms, no PNS) per patient was recorded.
Conclusions
Over the relatively long term, the quadripolar LV lead was associated with excellent pacing thresholds and low rates of dislocation and PNS. 相似文献
Pelvic organ prolapse is a common condition impacting the quality of life of millions of women worldwide. Although vaginal estrogen is widely used in women with prolapse, little is known regarding estrogen’s benefits on the biomechanical properties of vaginal tissue. Here, we aimed to examine the effect of prolapse on the biomechanical properties of the vagina and determine alterations in vaginal mechanics in the presence and absence of hormone therapy (HT).
Methods
We characterized the viscoelastic properties of vaginal biopsies from age-matched premenopausal women without (n?=?12) and with prolapse (n?=?8) and postmenopausal women with prolapse on (n?=?18) and off HT (n?=?9). Utilizing a single-lap shear testing protocol, full-thickness anterior vaginal biopsies were subjected to ±10 % shear strain over a range of frequencies (1–90 Hz). This applied energy is either dissipated (viscous) or stored (elastic) as a function of frequency due to compositional or structural differences in the tissue.
Results
Prolapsed tissue was more stiff (higher complex modulus) under shear deformation resulting from increases in both elastic (elastic modulus) and viscous (loss modulus) contributions, with non-prolapsed premenopausal women being the least stiff. Postmenopausal women with prolapse currently on HT were the most stiff of all the groups.
Conclusions
These data suggest that prolapsed tissue has an increased elastic contribution likely resulting from changes in biochemical constituents, and hormones increase the viscous contribution of prolapsed tissue. Overall, this study design characterized the viscoelastic properties of vaginal biopsies and may be utilized to conduct longitudinal studies to better understand the mechanisms of prolapse development and progression. 相似文献
Gut microbiota is represented by different microorganisms that colonize the intestinal tract, mostly the large intestine, such as bacteria, fungi, archaea and viruses. The gut microbial balance has a key role in several functions. It modulates the host’s metabolism, maintains the gut barrier integrity, participates in the xenobiotics and drug metabolism, and acts as protection against gastro-intestinal pathogens through the host’s immune system modulation. The impaired gut microbiota, called dysbiosis, may be the result of an imbalance in this equilibrium and is linked with different diseases, including cancer. While most of the studies have focused on the association between microbiota and gastrointestinal adenocarcinomas, very little is known about gastroenteropancreatic (GEP) neuroendocrine neoplasms (NENs). In this review, we provide an overview concerning the complex interplay between gut microbiota and GEP NENs, focusing on the potential role in tumorigenesis and progression in these tumors.
T(3) regulates energy metabolism by stimulating metabolic rate and decreasing metabolic efficiency. The discovery of mitochondrial uncoupling protein 3 (UCP3), its homology to UCP1, and regulation by T(3) rendered it a possible molecular determinant of the action of T(3) on energy metabolism, but data are controversial. This controversy may in part be attributable to discrepancies observed between the regulation by T(3) of UCP3 expression in rats, humans, and mice. To clarify this issue, we studied 1) the induction kinetics of the UCP3 gene by T(3) in rat skeletal muscle, 2) the influence of fatty acids, and 3) the structure and regulation of the various UCP3 promoters by T(3). Within 8 h of single-dose T(3) administration, hypothyroid rats showed a rise in serum fatty acid levels concomitant with a rapid increase in UCP3 expression in gastrocnemius muscle, followed by inductions of peroxisome proliferator activated receptor delta (PPARdelta) (within 24 h) and PPAR target gene expression (after 24 h). This T(3)-induced early UCP3 expression depended on fatty acid-PPAR signaling because depleting serum fatty acid levels abolished its expression, restorable by administration of the PPARdelta agonist L165,041 (4-[3-(4-acetyl-3-hydroxy-2-propylphenoxy)propoxy]phenoxy]acetic acid). In transfected rat L6 myoblasts, only the rat UCP3 promoter positively responded to T(3) and L165,041 together in the presence of MyoD, thyroid hormone receptor beta1 (TRbeta1), PPARdelta, or PPARdelta plus the TR dimerization partner retinoid X receptor alpha. All promoters share a response element common to TR and PPAR (TRE 1), but the observed species differences may be attributable to different localizations of the MyoD response element, which in the rat maps to exon 1. 相似文献