Comparison of the biomechanical effect of posterior condylar offset and kinematics between posterior cruciate-retaining and posterior-stabilized total knee arthroplasty

Background

The effect of the changes in the femoral posterior condylar offset (PCO) on anterior–posterior (AP) translation and internal–external (IE) rotation in cruciate-retaining (CR) and posterior-stabilized (PS) total knee arthroplasty (TKA) remains unknown. The purpose of this study was to compare the kinematics in CR and PS TKA with respect to the difference in prosthetic design and PCO change through a computational simulation.

Additive Antinociception between Intrathecal Sildenafil and Morphine in the Rat Formalin Test

The possible characteristics of spinal interaction between sildenafil (phosphodiesterase 5 inhibitor) and morphine on formalin-induced nociception in rats was examined. Then the role of the opioid receptor in the effect of sildenafil was further investigated. Catheters were inserted into the intrathecal space of male Sprague-Dawley rats. For induction of pain, 50 µL of 5% formalin solution was applied to the hind-paw. Isobolographic analysis was used for the evaluation of drug interaction between sildenafil and morphine. Furthermore, naloxone was intrathecally given to verify the involvement of the opioid receptor in the antinociception of sildenafil. Both sildenafil and morphine produced an antinociceptive effect during phase 1 and phase 2 in the formalin test. The isobolographic analysis revealed an additive interaction after intrathecal delivery of the sildenafil-morphine mixture in both phases. Intrathecal naloxone reversed the antinociception of sildenafil in both phases. These results suggest that sildenafil, morphine, and the mixture of the two drugs are effective against acute pain and facilitated pain state at the spinal level. Thus, the spinal combination of sildenafil with morphine may be useful in the management of the same state. Furthermore, the opioid receptor is contributable to the antinocieptive mechanism of sildenafil at the spinal level.     

Primary malignant melanoma of the cervical spinal nerve root

The authors report on a case of primary malignant melanoma of the 7th cervical spinal nerve root in a 45-year-old woman. Neuro-radiological features of this extra-dural mass were suggestive of a nerve sheath tumor. The lesion underwent total gross resection through the anterolateral approach. The patient's postoperative course was uneventful. Histopathological investigation confirmed malignant melanoma. There was no evidence of tumor recurrence or other melanotic lesions on regular follow-up examinations until the postoperative eighth month. When treating a common, benign-looking lesion of the cervical spinal nerve root, surgeons should be aware of the potential to encounter such a malignant tumor.     

Two cases of chronic pancreatitis with pseudocyst complicated by obstructive jaundice

We recently treated two cases of chronic pancreatitis with obstructive jaundice due to compression of the common bile duct by pancreatic pseudocyst. The two cases were males admitted with the complaint of icteric skin color. The first, a 46-year-old male, admitted with the complaint of icteric skin color. He was treated by operative cystojejunostomy after percutaneous drainage of the pseudocyst and percutaneous transhepatic biliary drainage. The other case was a 58 year-old male who admitted with the complaint of icteric skin color. He had an infected pseudocyst in the pancreas and was endoscopically treated. Both of them were discharged with favorable clinical course and normal laboratory findings after the treatment. The former patient remained well 11 months after treatment, but the latter patient died from necrotizing pancreatitis and septic shock 6 months after treatment. Most cases of obstructive jaundice associated with pseudocysts appear to be due to fibrotic stricture of the intrapancreatic portion of the common bile duct rather than due to compression of the bile duct by the pseudocyst. In a patient with secondary pancreatic infection or obstructive jaundice following pancreatic disease, differentiating between these two conditions is an important aspect of accurate diagnosis and therapy. Herein we report two unusual cases of chronic pancreatitis with pseudocyst complicated by obstructive jaundice.     

Biological Activity of a Mouse-Human Chimeric Immunoglobulin G2 Antibody to Cryptococcus neoformans Polysaccharide

The variable regions of the heavy and light chains of the protective murine monoclonal antibody (MAb) 2H1 (m2H1) were expressed with the human constant region genes for immunoglobulin G2 (IgG2) and kappa, respectively, to construct a chimeric antibody (ch2H1). ch2H1 retains the specificity of the parent MAb, exhibits biological activity, and lacks the toxicity of the parent murine IgG1 in chronically infected mice.     

Malignant rhabdoid tumor of the kidney--a case report.

Malignant rhabdoid tumor is a distinct renal tumor in children. It had been regarded as a rhabdomyosarcomatoid variant of Wilms' tumor, but it is now thought as a separate entity. We report a case of malignant rhabdoid tumor of the kidney in a 26-month-old girl who presented with a left abdominal mass. Grossly, a large mass in the lower pole of the left kidney was well encapsulated and measured 4 x 4 x 3.5cm. On cross section, it was soft and yellowish white and showed multifocal necroses. The mass was mainly located in the medial medullary portion and compressed the renal pelvis laterally. Microscopically, the tumor masses were hypercellular and anaplastic without definite blastematous elements. In larger portion, the tumor cells had abundant eosinophilic cytoplasm and hyaline globules. In addition to the classic "rhabdoid" feature, alveolar, sclerosing, and lymphomatous patterns were seen. Ultrastructurally, tumor cells with abundant cytoplasm contained tangles of intermediate filament corresponding to vimentin in immunostaining.     

Mechano-active scaffold design of small-diameter artificial graft made of electrospun segmented polyurethane fabrics

To fabricate a "mechano-active" tubular scaffold of nonwoven mesh-type small-diameter artificial graft made of the synthetic durable elastomer, segmented polyurethane, the fabrication technique of electrospinning on a mandrel under a high rotation speed and transverse movement was used. Emphasis was placed on how the rotation speed of the mandrel and the fusion or welding states of fibers at contact points affect the compliance (ease of intraluminal pressure-dependent circumferential inflation) and Young's modulus determined by uniaxial stretching in the longitudinal and circumferential directions. The results showed that a high rotation speed is attributed to exhibit isotropic mechanical properties in the entire range of applied strain but reduces the compliance, and a high fusion state, which is produced using a mixed solvent with a high content of high-boiling-point solvent, reduces the compliance but is expected to exhibit high durability in a continuously loaded pulsatile stress field in an arterial circulatory system.     

Inhibition of interleukin-8 expression by dexamethasone in human cultured airway epithelial cells.

Interleukin-8 (IL-8) is a neutrophil chemotactic factor expressed in many cell types, including human airway epithelial cells (HAEC). Inhaled corticosteroids are now used increasingly early in the treatment of airway inflammation such as in asthma, and directly interact with HAEC at relatively high concentrations. We have investigated the effect of dexamethasone on IL-8 expression in primary cultured HAEC obtained from transplantation donors. Northern blot analysis was used to measure IL-8 mRNA levels in HAEC, and radioimmunoassay was used to measure IL-8 protein in culture supernatant fluids. We demonstrated that IL-8 was expressed by primary cultured HAEC and that this was enhanced by IL-1 beta and tumour necrosis factor-alpha stimulation, but not by IL-6 or lipopolysaccharide. Dexamethasone suppressed IL-8 mRNA expression and protein synthesis dose-dependently in both resting and stimulated HAEC. The half-life of IL-8 mRNA determined in the presence of actinomycin D was less than 1 hr, and dexamethasone preincubation had no effect on mRNA stability. These results support the view that HAEC may play an important role in the pathogenesis of airway inflammatory diseases, and that glucocorticosteroids may exert their anti-inflammatory effects by blocking IL-8 gene expression and generation in these cells.     

Expression of E-cadherin and alpha-, beta-, gamma-catenin proteins in endometrial carcinoma

Loss of the cell adhesion molecule E-cadherin is suggested to promote tumor invasion and distant metastasis in tumor development. Recently, it has been proposed that E-cadherin function requires its linkage to the cytoskeleton through catenins. We evaluated the expression of E-cadherin and alpha-, beta-, gamma-catenins in tissues of human endometrial carcinoma, analyzed the patterns of cell adhesion molecules' expression in endometrial carcinoma and investigated the relationship between the statuses of cell adhesion molecules and various clinicopathological factors. This study investigated the immunohistochemical expression of E-cadherin and alpha-, beta-, gamma-catenins in 33 paraffin embedded formalin fixed tissues of endometrial carcinomas. Aberrant E-cadherin, and alpha-, beta-, gamma-catenin expression was observed in 33.3 (11 of 33), 27.3 (9 of 33), 18.2 (6 of 33), and 51.5 (17 of 33) % of the specimens, respectively. Statistically significant correlation was found between aberrant expression of E-cadherin and lymph node metastasis and cell types other than endometrioid adenocarcinoma. Aberrant pattern of gamma-catenin expression was also correlated with deep myometrial invasion. However, alpha-, and beta-catenin expression was not correlated with any clinicopathological parameters. Using the Kaplan-Meier method and log-rank comparison test, abnormal expression of E-cadherin was correlated closely with poor survival (p < 0.05), but cases with loss of both E-cadherin and catenin expression predicted even poorer survival than cases with only one or no aberrant expression in E-cadherin and catenins. We revealed aberrant expression of these cell adhesion molecules among patients with endometrial carcinoma. Aberrant expression of E-cadherin was correlated with lymph node metastasis and cell types other than endometrioid adenocarcinoma, while aberrant expression of gamma-catenin was related with deep myometrial invasion. The expression of E-cadherin might be a possible prognostic factor for endometrial cancer while the expression of catenins may help predict patient's survival.     

Clonorchis sinensis: molecular cloning and localization of myosin regulatory light chain

One cDNA clone was purified from an adult Clonorchis sinensis cDNA library, and its deduced polypeptide sequence was found to be homologous with myosin regulatory light chain (MRLC) of invertebrates and vertebrates. Two amino-acid residues, Thr and Ser, were conserved at the phosphorylation sites that regulate the function of MRLCs. Recombinant C. sinensis MRLC (rCsMRLC) protein was produced and purified from Escherichia coli, and mouse anti-CsMRLC immune sera recognized a protein of molecular weight 24 kDa from a soluble protein preparation of C. sinensis. The CsMRLC protein was immunohistochemically localized to the muscle fibers of the subtegumental muscle layer and to the muscles of oral and ventral suckers. However, the rCsMRLC protein proved to be less useful antigen for the serodiagnosis of human clonorchiasis.The nucleotide sequence reported herein was submitted to GenBank and assigned accession number AY519356.