SummaryRecombinant factor Vila (rFVIIa; NovoSeven®) is a recent addition to the hemostatic alternatives for the treatment of hemophiliacs with inhibitors. A drawback in the use of rFVIIa has been its half-life of only about 2 h, which necessitates very frequent and punctual injections. We evaluated the stability of reconstituted, but not further diluted, rFVIIa in 3 infusion systems (WalkMedTM 350 and CADD®-Plus minipumps and Meddex 2001 syringe pump). The factor VII (F VII) activity was maintained for at least 3 days at room temperature with only a minor and clinically insignificant increase in oxidized forms of rFVIIa and minimal leaching of the plastic softeners di-butylphthalate and di-octylphthalate after 24–48 h. Addition of heparin, 5–10 U/ml, to reconstituted rFVIIa caused a loss of about 50% of the activity within 4 h of storage in the infusion system, whereas low molecular weight heparin had no such effect. Repeated samples showed that the infusion systems maintained sterility. Reconstituted rFVIIa did not support bacterial growth when inoculated with Staphylococcus aureus or Escherichia coli to any greater extent than did reconstituted factor VIII, lidocaine in saline or heparin in saline. Two patients were treated with continuous infusion of rFVIIa on 4 occasions (total knee arthroplasty, wound revision, and twice straightening of a 90° contracture of the knee under general anaesthesia). A preoperative pharmacokinetic evaluation was performed, and the clearance was used to calculate the maintenance dose, aiming at a FVII level of 10 U/ml, which proved to be a hemostatic level. The first patient had no change in the clearance during the two treatment episodes. He suffered from repeated thrombophlebitis at the infusion site. The second patient had a progressive decrease of the clearance from 86.4 to 24.7 ml/h/kg. He received during the first treatment a parallel infusion with heparin (≈250 U/24 h) to the same venous access and did not develop thrombophlebitis during 3.5 days of therapy. For the second episode low molecular weight heparin was added directly to the infusion bag, and no adverse effects were observed. Continuous infusion with rFVIIa is thus feasible with the minipumps used by us, eliminates the need for 2 h injections and reduces the total dose of rFVIIa by 50–75%, depending on the behaviour of the clearance.
Abstract-Human subjects with impaired baroreflex function cannot buffer rises or falls in blood pressure (BP), thus allowing BP effects of endogenous or environmental stimuli that previously escaped detection to emerge dramatically. Studies in these patients led us to discover that water ingestion induced a robust increase in BP and vascular resistance. Here, using a mouse model of baroreflex impairment, we show that the increase in blood pressure after water ingestion is mediated through sympathetic nervous system activation and that the osmosensitive transient receptor potential vanilloid 4 channel (Trpv4) is an essential component of the response. Although portal osmolality decreases after water ingestion in both wild-type and Trpv4 Ϫ/Ϫ mice, only the wild-type animals show a pressor response. The same volume of physiological saline does not elicit an increase in BP, suggesting osmolality as the stimulus. The osmopressor response to water, and Trpv4 thus represent new factors now implicated in the physiology of BP regulation. (Hypertension. 2010;55:1438-1443.) Key Words: Trpv4 Ⅲ blood pressure Ⅲ osmopressor Ⅲ sympathetic nervous system Ⅲ baroreflex S tudies in patients with baroreflex impairment led us to discover that water ingestion increases blood pressure (BP) and vascular resistance. We found that ingestion of 16 oz (473 mL) of water induces a profound increase in systolic BP, averaging Ϸ40 mm Hg, with occasional increases Ͼ75 mm Hg. The effect appears within 10 minutes, is maximal at 25 to 40 minutes, and largely dissipates by 90 minutes after ingestion. Although the effect of water was greatest in individuals with impaired baroreflex buffering, it was also present in healthy persons. In healthy young subjects with intact baroreflexes, water elicits an increase in peripheral vascular resistance without an increase in BP because of a compensatory reduction in cardiac output. 1 Importantly, water ingestion raises plasma norepinephrine but not renin or vasopressin, supporting a sympathetic nervous system mechanism. 2,3 Furthermore, induction of reversible autonomic blockade with the autonomic ganglionic blocking drug trimethaphan abolishes the pressor action of water. 2 Although these studies in human subjects suggest a sympathetic nervous system mechanism for the pressor action of water, we sought to discover the physiological and molecular basis of the response. There has been increasing interest in splanchnic, neural, and vascular mechanisms in BP control in a number of animal models. 4 The transient receptor potential cation channel family, especially the vanilloid family (TRPV), constitutes potential mediators of the pressor response to water. These channels mediate the effects of many environmental factors, including osmolality and stretch, on neuronal and cardiovascular function. 5 Trpv4, in particular, is sensitive to osmotic perturbations 6,7 and is found along the gastrointestinal (GI) tract, mesenteric vessels, liver, cholangiocytes, dorsal root ganglia, and other locations throughout the body. ...
Endometrial expression of matrix metalloproteinase (MMP)-3, MMP-7 and MMP-11 occurs during menstrual breakdown and subsequent estrogen-mediated growth, but not during the secretory phase. These enzymes are suppressed by progesterone treatment. Paracrine factors, including transforming growth factor-β (TGF-β) and retinoic acid, are also critical for MMP regulation in the endometrium. In contrast, inflammatory cytokines such as interleukin-1α may block or interfere with steroid-mediated MMP regulation at ectopic sites of growth. Using in vitro models, our laboratory has investigated the complex interactions between progesterone and locally produced cytokines that may affect MMP expression during the development of endometriosis. Our results indicate that targeting the regulation of MMPs may represent an appropriate therapeutic strategy for the treatment of endometriosis.
Abnormal autonomic nerve traffic has been associated with a number of peripheral neuropathies and cardiovascular disorders prompting the development of genetically altered mice to study the genetic and molecular components of these diseases. Autonomic function in mice can be assessed by directly recording sympathetic nerve activity. However, murine sympathetic spikes are typically detected using a manually adjusted voltage threshold and no unsupervised detection methods have been developed for the mouse. Therefore, we tested the performance of several unsupervised spike detection algorithms on simulated murine renal sympathetic nerve recordings, including an automated amplitude discriminator and wavelet-based detection methods which used both the discrete wavelet transform (DWT) and the stationary wavelet transform (SWT) and several wavelet threshold rules. The parameters of the wavelet methods were optimized by comparing basal sympathetic activity to postmortem recordings and recordings made during pharmacological suppression and enhancement of sympathetic activity. In general, SWT methods were found to outperform amplitude discriminators and DWT methods with similar wavelet coefficient thresholding algorithms when presented with simulations with varied mean spike rates and signalto-noise ratios. A SWT method which estimates the noise level using a "noise-only" wavelet scale and then selectively thresholds scales containing the physiologically important signal information was found to have the most robust spike detection. The proposed noise-level estimation method was also successfully validated during pharmacological interventions.
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