The effects of N(omega)-propyl-L-arginine on reperfusion injury of skeletal muscle.

N(omega)-Propyl-L-arginine (NPA) is reported to be a highly selective inhibitor of neuronal nitric oxide synthase (nNOS). This in vivo study observed its role in ischemia/reperfusion (I/R) injury in rat skeletal muscle. Our results showed that NPA infusion significantly increased vessel diameters and blood flow in reperfused cremaster muscle, and slightly increased contractile function in reperfused extensor digitorum longus (EDL) muscle.

Inhibition of iNOS with 1400W improves contractile function and alters nos gene and protein expression in reperfused skeletal muscle.

This study examined the effects of 1400W, an inhibitor of inducible nitric oxide (iNOS), on contractile function and iNOS expression in reperfused skeletal muscle. The right extensor digitorum longus (EDL) muscle of 104 rats underwent a sham operation or 3-h ischemia followed by 3-h or 24-h reperfusion (I/R). Rats received 3 mg/kg 1400W, 10 mg/kg 1400W, or water subcutaneously.

NF-kappaB p65 involves in reperfusion injury and iNOS gene regulation in skeletal muscle.

This study investigated the effects of inhibition of NF-kappaB activation on microcirculation and inducible NOS expression in reperfused rat cremaster muscle. The muscle from 16 rats underwent 5-h ischemia and 90-min reperfusion. Each rat received NF-kappaB inhibitor pyrrolidine dithiocarbamate (PDTC, 150 mg/kg) or phosphate-buffered saline 15 min before reperfusion.

Analysis of failures after vascularized fibular grafting in femoral head necrosis.

Evaluation of graft-host bone interactions after failed vascularized fibular grafting of femoral head necrosis may elucidate the reasons for failure of the procedure. According to the authors' study, the vascularized fibula implanted into the femoral head before collapse has the potential for restructuring the major segment of the affected head and delaying joint degeneration for many years if circumferential graft-host union is established. Asymmetric bone healing and non-union between the graft and the necrotic subchondral bone in the weight-bearing area lead to failure, progression of symptoms, and subsequent early hip replacement.

Nitric oxide involvement in reperfusion injury of denervated muscle.

Purpose: To investigate whether inhibition of inducible nitric oxide synthase (iNOS) improves microcirculation in denervated and reperfused skeletal muscle.

Methods: The cremaster muscles of 52 rats received iNOS inhibitor 1400W (3 mg/kg) or phosphate buffered saline (PBS) and underwent either 3 hours of ischemia and 1.5 hours of reperfusion or a sham operation.

Reperfusion injury in skeletal muscle is reduced in inducible nitric oxide synthase knockout mice.

Inducible nitric oxide synthase (iNOS) participates in many pathological events, and selective inhibition of iNOS has been shown to reduce ischemia-reperfusion (I/R) injury in different tissues. To further confirm its role in this injury process, I/R injury was observed in denervated cremaster muscles of iNOS-deficient (iNOS-/-) and wild-type mice. After 3-h ischemia and 90-min reperfusion, blood flow in reperfused muscle was 80 +/- 8.

C1-esterase inhibitor and a novel peptide inhibitor improve contractile function in reperfused skeletal muscle.

To determine the role of inhibition of complement activation in the contractile function of skeletal muscle ischemia-reperfusion (I/R) injury, the rat extensor digitorum longus (EDL) muscles underwent 3 h ischemia and received human C1-esterase inhibitor (C1-INH, 100 IU/kg), a synthetic C1q A chain peptide with a similar inhibitory effect on activated C1 (peptide, 5 mg/kg), or human serum albumin control. Results showed a significant overall increase in tetanic contractile forces of the reperfused EDL in both C1-INH and peptide groups compared to controls. Maximum improvement occurred with peptide treatment at 120-Hz stimulation, with an increase in force from 38 +/- 4% of normal in controls to 52 +/- 4% in peptide-treated rats.

Reperfusion injury is reduced in skeletal muscle by inhibition of inducible nitric oxide synthase.

This study evaluated the effects of the selective inducible nitric oxide synthase (iNOS) inhibitor N-[3-(aminomethyl)benzyl]acetamidine (1400W) on the microcirculation in reperfused skeletal muscle. The cremaster muscles from 32 rats underwent 5 h of ischemia followed by 90 min of reperfusion. Rats received either 3 mg/kg 1400W or PBS subcutaneously before reperfusion.

Effect of a nitric oxide donor on microcirculation of acutely denervated skeletal muscle during reperfusion.

The authors have shown that exogenous nitric oxide (NO) protects innervated skeletal muscle against reperfusion injury. This study further evaluated the effects of exogenous NO donor on denervated skeletal muscle. Forty-eight denervated rat cremaster muscles underwent 3 hr of ischemia, followed by 90 min of reperfusion, and received systemic infusion of 100 nmol/min s-nitroso-n-acetylcysteine (SNAC) or an equal amount of phosphate-buffered saline (PBS).

Role of nitric oxide in vasodilation in upstream muscle during intermittent pneumatic compression.

This study investigated the dosage effects of nitric oxide synthase (NOS) inhibitor N(G)-monomethyl-L-arginine (L-NMMA) on intermittent pneumatic compression (IPC)-induced vasodilation in uncompressed upstream muscle and the effects of IPC on endothelial NOS (eNOS) expression in upstream muscle. After L-NMMA infusion, mean arterial pressure increased by 5% from baseline (99.5 +/- 18.

Gene and protein expressions of nitric oxide synthases in ischemia-reperfused peripheral nerve of the rat.

This study examined mRNA and protein expressions of neuronal (nNOS), inducible (iNOS), and endothelial nitric oxide synthases (eNOS) in peripheral nerve after ischemia-reperfusion (I/R). Sixty-six rats were divided into the ischemia only and I/R groups. One sciatic nerve of each animal was used as the experimental side and the opposite untreated nerve as the control.

Comparison of continuous and interrupted suture techniques in microvascular anastomosis.

We evaluated the efficacy of the continuous suture technique (CST) in arteries and veins with varying external diameters (ED). In study 1 a direct end-to-end anastomosis was performed in 5 groups of animals (n = 15 in each group): group 1, rabbit carotid artery (ED, 1.8-2.

Hemorrhage and thrombus formation in early experimental osteonecrosis.

The aim of the current study was to test the hypothesis that the induction of an underlying immunologic condition in rabbits may enhance the development of steroid-induced osteonecrosis. Thirty-five adult rabbits were divided into four groups. Group I: 10 rabbits were immunized at 15-day intervals for 2 months by murine antibodies to deoxyribonucleic acid autoantibodies.

Blockade of L-selectin attenuates reperfusion injury in a rat model.

Ischemia/reperfusion (I/R) injury appears to be a significant neutrophil-dependent component and may be ameliorated by blocking leukocyte-endothelial adhesion. Using a rat extensor digitorum longus (EDL) muscle model, the present study tested the hypothesis that in vivo administration of the function-blocking monoclonal antibody (mAb) LAM1-116 which recognizes L-selectin, a cell-surface adhesion receptor, could decrease I/R injury. In 46 rats, one EDL served as a normal control and the opposite EDL underwent 3 hr of ischemia followed by 3 hr of reperfusion after pretreatment with LAM1-116 mAb, control IgG, or saline.

Interleukin-1 beta promotes functional recovery of crushed peripheral nerve.

This study was conducted to elucidate the role of the cytokine interleukin-1 beta on peripheral nerve recovery following crush injuries of two different magnitudes. Eighty-eight female rats were divided into four groups. A 5-mm segment of the right sciatic nerve was subjected to a 100-g crush load for 2 hours in the rats in Groups A1 and B1 or to a 15,000-g crush load for 10 minutes in the rats in Groups A2 and B2.

Influences of inflation rate and duration on vasodilatory effect by intermittent pneumatic compression in distant skeletal muscle.

Previous study has demonstrated that application of intermittent pneumatic compression on legs can cause vasodilation in distant skeletal muscle at the microcirculation level. This study evaluated the influence of inflation rate and peak-pressure duration on the vasodilatory effects of intermittent pneumatic compression. The cremaster muscles of 50 male rats were exposed and divided into five groups of 10 each.

Motor functional and morphological findings following end-to-side neurorrhaphy in the rat model.

Nerve repair cannot always be achieved by the conventional end-to-end technique. This study evaluated the functional recovery of nerves repaired with end-to-side neurorrhaphy in a rat model. The right peroneal nerves of 80 female rats were transected and divided into four groups.

Intermittent pneumatic compression of legs increases microcirculation in distant skeletal muscle.

Intermittent pneumatic compression has been established as a method of clinically preventing deep vein thrombosis, but the mechanism has not been documented. This study observed the effects of intermittent pneumatic compression of legs on the microcirculation of distant skeletal muscle. The cremaster muscles of 80 male rats were exposed, a specially designed intermittent pneumatic-compression device was applied to both legs for 60 minutes, and the microcirculation of the muscles was assessed by measurement of the vessel diameter in three categories (10-20, 21-40, and 41-70 microm) for 120 minutes.

Effect of a NOS inhibitor, L-NMMA, on the contractile function of reperfused skeletal muscle.

The authors investigated the effect of NG-monomethyl-L-arginine acetate (L-NMMA), a nitric oxide synthase (NOS) inhibitor, on the contractile function of skeletal muscle following ischemia/reperfusion (I/R) injury. The extensor digitorum longus (EDL) muscles of 50 rats were divided into seven groups. Contractile function in non-ischemic EDL did not change statistically significantly with L-NMMA infusion.

Recombinant human glial growth factor 2 (rhGGF2) improves functional recovery of crushed peripheral nerve (a double-blind study).

This in vivo double-blind study evaluated the effect of recombinant human glial growth factor 2 (rhGGF2), a Schwann cell mitogen, on the recovery of motor function of rat sciatic nerve following crush injury. Seventy three rats were divided into three groups. Group I (n=5), sham operated; Groups II (n=34) and III (n=34) received a 100 g crush load for 2 h over a 5 mm segment of the sciatic nerve.

S-nitroso-N-acetylcysteine protects skeletal muscle against reperfusion injury.

The effects of a nitric oxide (NO) donor on microcirculation and contractile function of reperfused skeletal muscle were studied. Rat cremaster muscles underwent 5 hours of ischemia and 90 minutes of reperfusion and were divided into two groups systemically infused with S-nitroso-N-acetylcysteine (SNAC, 100 nmol/min) and phosphate-buffered saline (PBS), respectively. The results showed that the vessels in the SNAC group had more rapid and complete recovery than that in controls.

Effect of increased compartment pressure on the microcirculation of skeletal muscle.

To determine the changes in capillary perfusion, which occur with elevated tissue pressure, and to highlight the relationship between systemic blood pressure and compartment pressure, we designed an experiment that allowed direct observation of the microcirculation of skeletal muscle under normal and increased compartment pressures. In each of 10 anesthetized rats, the cremaster muscle was exposed and suspended in a transparent pressure chamber. In vivo videomicroscopy was then performed and blood pressure was monitored via left carotid artery cannulation.

Pharmacokinetics of a degradable drug delivery system in bone.

Local delivery of antibiotics via a degradable carrier has the potential for high local antibiotic levels and avoids systemic toxicity. Intravenous access, renal function monitoring, and later surgical removal may not be required when degradable local delivery modalities are used. This study examined the in vivo elution of gentamicin from processed bovine collagen (Type I).

Effects of S-nitroso-N-acetylcysteine on contractile function of reperfused skeletal muscle.

The ultimate goal of replantation and microsurgical reconstructive operations is to regain or improve impaired function of the tissue. However, the data related to the influence of NO on tissue function are limited. This study evaluated the effects of the NO donor S-nitroso-N-acetylcysteine (SNAC) on contractile function of skeletal muscle during reperfusion.

Anticardiolipin antibodies and osteonecrosis of the femoral head.

The current study evaluated the prevalence of anticardiolipin antibodies, which have been associated with thrombotic phenomena, in patients with nontraumatic osteonecrosis of the hip and assessed whether the presence of such antibodies is associated with an increased risk for the development of bone necrosis. Forty consecutive patients (25 men and 15 women) with nontraumatic osteonecrosis of the hip were studied. Their ages ranged from 19 to 56 years (average, 34.