Non-viral in vivo thrombomodulin gene transfer prevents early loss of thromboresistance of grafted veins.

OBJECTIVE: Immediate loss of thrombomodulin activity in the endothelium of vein grafts has been demonstrated during 90 min exposure to arterial circulation; this loss of activity is ascribed as an important cause of early thrombosis. Conventional ex vivo gene transfection after vein harvest cannot cover this acute period immediately after implantation. We have established a highly efficient non-viral gene therapy protocol utilizing modified transferrin receptor-facilitated gene transfer. Using this technique, we examined whether in vivo thrombomodulin gene therapy, directed to the endothelium of rat veins 2 days prior to grafting, may prevent thromboresistance impairment of vein grafts under simulated arterial circulation. METHODS: Abdomen of SD rat was opened and cationic liposome:transferrin:thrombomodulin gene complexes or the vector without DNAs were applied to the inferior vena cava of rats while blood flow was reduced by proximal and distal clamping. After 2 days, the transfected veins were harvested and thrombomodulin expression and thromboresistance properties determined before and after exposure to an artificial circuit. RESULTS: The trial of gene transfection using variable doses of DNAs confirmed that 7.5 microg of total DNAs was the most efficient quantity for thrombomodulin gene transfection to IVCs, although accompanying an increase of gene expression in other downstream organs. By transfection of the thrombomodulin gene in IVCs, the generation capacity of activated protein C in venous endothelium increased three-fold compared with veins treated with vector alone (P<0.01). Under simulated arterial circulation, perfusion of veins treated with vector alone decreased thrombomodulin activity to 36% of preperfused levels (P<0.01), whereas transfected grafts preserved the activity at normal vein endothelium levels even after perfusion. Consequently, the increase in endothelial thrombin activity induced by simulated arterial circulation was markedly attenuated in transfected veins (P<0.01), while immunohistochemistry confirmed the preservation of endothelial lining. CONCLUSIONS: Transferrin receptor-facilitated in vivo gene transfer to the inferior vena cava resulted in sufficient thrombomodulin gene expression immediately after graft implantation and subsequent maintenance of thromboresistance even after exposure to arterial pressure. Although further studies are needed, the present results suggest the possibility of gene therapy targeting acute phases of vein graft disease.     

Effects of and predictors for tacrolimus rescue therapy among renal transplant patients under cyclosporine-based immunosuppression

BACKGROUND: Though cyclosporine has dramatically decreased rejection rates and improved graft survival rates of renal allografts, there is still a remarkable rate of acute rejection and progressive deterioration of renal function after transplantation. Rescue therapy with tacrolimus has been used for allografts failing under cyclosporine-based treatment in order to get some renal functional recovery or stabilization. The aim was to evaluate tacrolimus rescue therapy for failing allografts under cyclosporine-based immunosuppression for possible prediction factors for success. PATIENTS AND METHODS: Thirty-five renal allograft recipients with failing transplants under cyclosporine-based immunosuppression were enrolled into this study. Renal function was evaluated by reciprocal serum creatinine level (1/Cr) and calculated CCr. The slope of changes in 1/Cr and CCr were calculated before and after tacrolimus therapy. The possible risk factors that affect the outcome of tacrolimus rescue therapy were analyzed. RESULTS: Nineteen patients showed improved renal function (group 1) and 16 patients, persistent deterioration (group 2) after rescue therapy. Group 1 showed positive slopes of changes of 1/Cr and CCr after rescue therapy. Group 2 patients showed persistent negative slopes although less negative than before rescue therapy. Only the posttransplant time was the significant predictive factor for successful tacrolimus therapy (P = .018). CONCLUSION: Tacrolimus rescue therapy improved or stabilized renal function in some patients with failing grafts under cyclosporine-based immunosuppression. To assure a successful rescue effect, it should be given early after transplantation, if there is a tendency toward deterioration of renal function.     

Ultrasound for the detection of vegetative foreign body in hand--a case report.

Foreign bodies in soft tissues are commonly encountered in daily orthopaedic practice. While most of the metals and glass foreign bodies can be detected by plain radiograph, organic substances such as wood and vegetative materials are radiolucent. Unfortunately, these radiolucent foreign bodies are usually more prone to cause an inflammatory reaction and infection. The detection can be even more difficult in cases of multiple foreign bodies and in penetrating injuries with small innocuous skin wounds. Ultrasonography is a sensitive and reliable investigation for detection of foreign bodies in soft tissue. We present a case of penetration injury to thumb with residual radiolucent foreign bodies and demonstrate the proper role of ultrasonography in the management of foreign bodies in soft tissues.     

Laryngeal mask airway in patients with tracheal stents who are undergoing non-airway related interventions: report of three cases

The tracheal stent is an alternative nonsurgical management tool for patients with tracheal stenosis caused by disease or iatrogenic trauma. Some patients with tracheal stent may need to be anesthetized to allow invasive techniques or surgery to be performed. In these patients, general anesthesia by endotracheal intubation may dislodge the stent distally or cause lethal complications such as bleeding. We describe three patients with a tracheal stent in place, who were anesthetized using a Laryngeal Mask Airway for surgery, with smooth results.     

Predicting Nipple–Areolar Involvement Using Preoperative Breast MRI and Primary Tumor Characteristics

Background

Preoperative assessment of the nipple–areolar complex (NAC) is invaluable when considering nipple-sparing mastectomy. Our hypothesis is that breast magnetic resonance imaging (MRI) may predict involvement of the NAC with tumor.

Methods

Clinical, histopathologic, and imaging data were compiled for patients who underwent preoperative breast MRI followed by mastectomy or nipple-sparing mastectomy for malignancy between 2006 and 2009. Blinded rereview of all MRI studies was performed by a breast MRI imager and compared to initial MRI findings. Multivariate analysis identified variables predicting NAC involvement with tumor.

Results

Of 77 breasts, 18 (23 %) had tumor involving or within 1 cm of the NAC. The sensitivity of detecting histopathologically confirmed NAC involvement was 61 % with history and/or physical examination, and 56 % with MRI. Univariate analysis identified the following variables as significant for NAC involvement: large tumors near the nipple on preoperative MRI, node-positive disease, invasive lobular carcinoma, advanced histopathologic T stage, and neoadjuvant chemotherapy. On multivariate analysis, only tumor size >2 cm and distance from tumor edge to the NAC <2 cm on MRI maintained significance. Pearson correlation coefficient for MRI size compared to histopathologic size was 0.53 (P < 0.0001).

Conclusions

MRI is not superior to thorough clinical evaluation for predicting tumor in or near the NAC. However, MRI-measured tumor size and distance from the NAC are correlated with increased risk of NAC involvement. The combination of preoperative history and physical examination, tumor characteristics, and breast MRI can aid the surgeon in predicting a tumor-involved nipple more than any single modality alone.     

Enhancement of rat growth hormone binding by membrane disulfide reduction

The effect of disulfide reduction on the binding of [125I]rat GH (rGH) to rat liver plasma membranes and hepatocytes was studied to determine the role of disulfide bonds in the binding of GH to its receptor. The total amount of [125I] rGH bound to the liver receptors increased severalfold in the presence of dithiothreitol and mercaptoethanol. The nonspecific binding also increased at higher concentrations of the reductant, but the amount specifically bound was still greater in the presence of disulfide reductant. In contrast, the disulfide reductant inhibited [125I] human GH (hGH) binding and enhanced its displacement from hypophysectomized female rat hepatocytes. This was similar to the effect of reductants on [125I]hGH binding to normal female rat hepatocytes. The effect of the disulfide reductants on [125I]rGH binding could be prevented or reversed by the simultaneous or subsequent addition of an oxidizing agent such as NAD or oxidized glutathione. Sulfhydryl-reactive agents such as iodoacetamide prevented additional binding of [125I]rGH when added at 30 min of the incubation. The additional [125I] rGH bound in the presence of disulfide reductant was displaceable by excess unlabeled rGH. Both rGH and hGH exhibited similar degrees of disulfide reduction in the presence of mercaptoethanol. The disulfide reductant produced effects on binding at concentrations that resulted in less than 10% reduction of the GH disulfides. We conclude that: 1) the disulfides and sulfhydryls of the hepatocyte membrane are intimately involved in the binding of GH to hepatic receptors; 2) the locus of the disulfides and sulfhydryls may be in the subunit structure of the membrane receptor, but this will require verification using soluble receptors; and 3) the effect of disulfide reducing agents reveals basic differences in the mechanism of binding of rGH and hGH to somatotropic hormone receptors on the hepatocytes.     

A dihydropyridine (Bay k 8644) that enhances calcium currents in guinea pig and calf myocardial cells. A new type of positive inotropic agent

Bay k 8644 is a structural analog of nifedipine with positive inotropic activity. The mechanism of drug action was evaluated by measuring the effects of Bay k 8644 on twitch tension, action potential configuration, and calcium channel currents in myocardial cells. Bay k 8644 increases twitch tension in guinea pig atria without changing the time course of tension development. The drug does not occlude the effect of isoproterenol on twitch tension. The effects of Bay k 8644 on atrial twitch tension are highly dependent on the frequency of stimulation. Maximal inotropic effects are observed at approximately 0.5 Hz, but no inotropic effect occurs at 0.003 Hz (a rested-state contraction). Since positive inotropic effects only occur with frequent electrical stimulation, they are not due to an intracellular action or to mechanisms that elevate cell calcium in quiescent muscle, such as inhibition of the Na,K-ATPase. Bay k 8644 increases the action potential duration of calf ventricular muscle and Purkinje fibers. Effects on action potential duration are occluded by 1 microM nisoldipine, which specifically blocks calcium channels. The interaction of Bay k 8644 with calcium channels in calf Purkinje fibers was studied using the two-microelectrode voltage clamp technique. Strontium was used as a charge carrier to minimize current through calcium-activated channels and to avoid changes in calcium conductance due to changes in intracellular calcium. Bay k 8644 increases strontium currents and alters the time- and voltage-dependence of channel opening. The greatest percent increase in strontium current occurs for weak depolarizations. For strong depolarizations, strontium current is increased most at the beginning of a test pulse. The drug-induced changes in calcium channel gating are inconsistent with a calcium- or cyclic adenosine monophosphate-mediated effect, and indicate a novel mechanism of action on calcium channels. Thus, Bay k 8644 is the first positive inotropic agent shown to act specifically and directly on calcium channels.     

Evaluation of Serum Pancreatic Enzymes, Carbohydrate Antigen 19-9, and Carcinoembryonic Antigen in Various Pancreatic Diseases

Comparative studies of pancreatic enzymes carbohydrate antigen 19-9 (CA 19-9) and carcinoembryonic antigen (CEA) were performed in various pancreatic disease. In acute pancreatitis as well as during acute exacerbation of chronic pancreatitis, all pancreatic enzymes were abnormally high. In chronic pancreatitis, they did not have any diagnostic sensitivity for pancreatic insufficiency. In pancreatic carcinoma, serum elastase levels may have a diagnostic value compared with other pancreatic enzymes. In studies of CEA and CA 19-9, both tumor markers were within normal range in benign pancreatitis but 27.7% of CEA and 30.7% of CA 19-9 in acute pancreatitis were above normal. In pancreatic carcinoma, although most of these patients had advanced disease, both tumor markers were extremely high and 61% for CEA and 71% for CA 19-9 were above normal. In patients with resected pancreatic carcinoma, serum CEA was slightly higher than normal CA 19-9 was much higher than normal. The sensitivity of CEA and CA 19-9 in this group were 33 and 77.7%, respectively. The results indicate that the CA 19-9 assay is a useful adjunct in the diagnosis of pancreatic carcinoma, possibly in the resectable stage especially combined measurement of serum elastase and CEA.     

Thyrotoxic thyroiditis after radiotherapy for Hodgkin's disease

Exposure of the thyroid gland to ionizing radiation has been associated with a variety of abnormalities. Among these are tardive hypothyroidism and an increased risk of developing thyroid nodules and cancer. Although acute thyroiditis has been known to complicate radioactive iodine 131 therapy, it has rarely been associated with external beam irradiation. Thyrotoxic painless thyroiditis developed in two patients after mantle-field irradiation for Hodgkin's disease.