Reattachment of an osteotomized greater trochanter in total hip arthroplasty using an ultra-high molecular weight polyethylene fiber cable

Background

The optimum approach in total hip arthroplasty (THA) should reduce the risk of postoperative dislocation or limping, be applicable in every case, and be reusable in the future. The purpose of this study was to introduce our transgluteal approach for THA and to evaluate the type and frequency of complications around the greater trochanter.

ampR gene mutations that greatly increase class C beta-lactamase activity in Enterobacter cloacae

The ampC and ampR genes of Enterobacter cloacae GN7471 were cloned into pMW218 to yield pKU403. Four mutant plasmids derived from pKU403 (pKU404, pKU405, pKU406, and pKU407) were isolated in an AmpD mutant of Escherichia coli ML4953 by selection with ceftazidime or aztreonam. The beta-lactamase activities expressed by pKU404, pKU405, pKU406, and pKU407 were about 450, 75, 160, and 160 times higher, respectively, than that expressed by the original plasmid, pKU403. These mutant plasmids all carried point mutations in the ampR gene. In pKU404 and pKU405, Asp-135 was changed to Asn and Val, respectively. In both pKU406 and pKU407, Arg-86 was changed to Cys. The ease of selection of AmpR mutations at a frequency of about 10(-6) in this study strongly suggests that derepressed strains, such as AmpD or AmpR mutants, could frequently emerge in the clinical setting.     

Transgenic rescue of insulin receptor-deficient mice

The role of different tissues in insulin action and their contribution to the pathogenesis of diabetes remain unclear. To examine this question, we have used genetic reconstitution experiments in mice. Genetic ablation of insulin receptors causes early postnatal death from diabetic ketoacidosis. We show that combined restoration of insulin receptor function in brain, liver, and pancreatic beta cells rescues insulin receptor knockout mice from neonatal death, prevents diabetes in a majority of animals, and normalizes adipose tissue content, lifespan, and reproductive function. In contrast, mice with insulin receptor expression limited to brain or liver and pancreatic beta cells are rescued from neonatal death, but develop lipoatrophic diabetes and die prematurely. These data indicate, surprisingly, that insulin receptor signaling in noncanonical insulin target tissues is sufficient to maintain fuel homeostasis and prevent diabetes.     

Newborn extracorporeal lung assist using a novel double lumen catheter and a heparin-bonded membrane lung

We report the clinical application of a novel double lumen catheter for veno-venous extracorporeal lung assist (ECLA) and the use of a heparin-bonded hollow fiber membrane lung, in the treatment of newborn respiratory failure. The outer lumen of the double lumen catheter was 14 Fr and was used for blood drainage; while the inner 8 Fr catheter was used for blood return. The double lumen catheter was made of spiral wire reinforced polyurethane, with a wall thickness of 0.25 mm. The hollow fiber membrane was made of non-microporous polyolefin, and was not permeable to water or plasma. We used this system to treat a newborn patient with meconium aspiration syndrome. Heparin was infused continuously at a rate of 18–25 units/kg/h, equal to 1/3 of the usual amount when a non-heparin bonded ECLA system was used and maintaining the activated clotting time near 120 s. Bleeding from cutdown sites was negligible. Only the right internal jugular vein was sacrificed. The patient was successfully weaned from ECLA and appears normal one year following discharge.     

Hepatic vascular and bile duct injury after ethanol injection therapy for hepatocellular carcinoma

Three patients with serious hepatic vascular injury after percutaneous ethanol injection therapy for hepatocellular carcinoma (HCC) are described. In two cases, immediately after ethanol injection, liver function tests deteriorated and computed tomography (CT) showed a wedge-shaped low-density area due to liver infarction. In the other case, 1 year after ethanol injection, the intrahepatic bile duct in the right lobe was dilated and the right hepatic lobe atrophied. Endoscopic retrograde cholangiography showed stenosis of the main right hepatic duct. Since complications include both acute and delayed vascular injury after ethanol injection, patients should be followed for a long period after treatment.     

Combination therapy with an angiotensin-converting enzyme inhibitor and an angiotensin II receptor blocker synergistically suppresses chronic pancreatitis in rats

We recently demonstrated that both lisinopril and candesartan, an angiotensin-converting enzyme inhibitor and angiotensin II type 1 receptor blocker, respectively, attenuate pancreatic inflammation and fibrosis in male Wistar Bonn/Kobori (WBN/Kob) rats. The purpose of the present study was to assess whether combination therapy with low doses of both, ineffective when given alone, might synergistically exert protective effects. Lisinopril, candesartan, or a combination of both in drinking water was administered to 10-week-old male WBN/Kob rats for 10 weeks. Parameters of inflammation and fibrosis, positive immunostaining for alpha-smooth muscle actin, and gene expression of cytokine and growth factors were assessed, as well as circulating renin-angiotensin system components. Dose-dependent effects of combination therapy were also investigated. Only combination therapy attenuated gross alterations in the pancreas, as quantitatively confirmed by increases in pancreatic weights and decreases in myeloperoxidase activity, hydroxyproline content, histologic scores, relative fibrosis area, and relative area of alpha-smooth muscle actin-positive cells. Combination therapy suppressed up-regulation of tumor necrosis factor-alpha, platelet-derived growth factor-receptor beta, and transforming growth factor-beta1 mRNA in the pancreas. Dose dependence of combination therapy was recognized with reference to improvement in these parameters. The conclusions are that combination therapy synergistically alleviated pancreatic inflammation and fibrosis in male WBN/Kob rats. This effect may be related to suppression of tumor necrosis factor-alpha, platelet-derived growth factor-receptor beta, and transforming growth factor-beta1 mRNA. Compared with the either therapy alone, combination therapy with an angiotensin-converting enzyme inhibitor and an angiotensin II type 1 receptor blocker may be more beneficial for treating chronic pancreatitis.     

Interferon-gamma stimulates the expression of CX3CL1/fractalkine in cultured human endothelial cells

CX3CL1/Fractalkine, a CX3C chemokine, is a potent agonist for the chemotaxis and adhesion of monocytes and lymphocytes. It was first identified as a membrane protein in endothelial cells activated with IL-1 or TNF-alpha. We have found the enhanced expression of fractalkine in human umbilical vein endothelial cells stimulated with interferon-gamma (IFN-gamma). Pretreatment of the cells with cycloheximide did not inhibit the expression of fractalkine mRNA. The majority of fractalkine protein was found in the cell lysate, and an antibody-blocking experiment disclosed that fractalkine contributes to the adhesion of mononuclear cells to endothelial monolayers stimulated with IFN-gamma. Vascular endothelial cells produce fractalkine in response to IFN-gamma, and this may play an important role in immune responses by eliciting a traffic of mononuclear cells through the vascular wall.