Attachment of a migrated MitraClip to the left ventricular apex: A novel case report

Herein, we report a novel case of emergency surgical mitral valve replacement for severe mitral valve regurgitation (MR) following MitraClip implantation (Abbott Laboratories, Chicago, IL, USA). Recurrent MR was caused because of the migration of the clip due to the destruction of the mitral valve leaflets with Staphylococcus aureus infective endocarditis. Intra-operative transesophageal echocardiography revealed that the clip was stuck to the left ventricular apex. Although the device could not be removed surgically, surgical repair of the valve enabled the patient to recover without any further complications.     

Antibacterial activity of carbapenems against clinical isolates of respiratory bacterial pathogens in the northeastern region of Japan in 2007

As the increasing prevalence of resistant strains of respiratory bacterial pathogens has recently been reported, continuous monitoring of the susceptibility of clinical isolates to antibacterial agents is important. We performed a surveillance study focusing on the susceptibility of major respiratory bacterial pathogens in the northeastern region of Japan to carbapenems and control drugs. A total of 168 bacterial strains isolated from patients with respiratory tract infections in 2007 were collected and the minimum inhibitory concentration (MIC) determined. MIC data were subjected to pharmacokinetic/pharmacodynamic analysis with Monte Carlo simulation to calculate the probability of achieving the target of time above MIC with each carbapenem. All Moraxella catarrhalis, Streptococcus pneumoniae, and methicillin-sensitive Staphylococcus aureus isolates were susceptible to carbapenems. Despite the increasing prevalence of β-lactamase-nonproducing ampicillin-resistant strains, all Haemophilus influenzae isolates were susceptible to meropenem. For Pseudomonas aeruginosa, the susceptibility rates for meropenem and biapenem were 76.7%, and the highest probability of achieving pharmacodynamic target (40% of the time above MIC) was obtained with meropenem 0.5 g three times daily as a 4-h infusion (89.4%), followed by meropenem 0.5 g four times daily as a 1-h infusion (88.4%). Carbapenems have retained their position as key drugs for severe respiratory tract infections.     

Human erythrocyte glucose transporter: normal asymmetric orientation and function in liposomes.

The transport function and orientation of the reconstituted human erythrocyte glucose transporter was studied with liposomes made with bovine brain lipid or Escherichia coli lipid. Reconstitution was achieved by a simple octyl glucoside dilution method. The reconstituted transporters with either lipid showed identical counterflow transport activity, the same response to various inhibitors, and characteristic cytochalasin B (CB) labeling. Functional location and purification of the glucose transporter was performed by using gel-permeation high-performance liquid chromatography with octyl glucoside-containing buffer. The reconstituted transport activity was associated only with band 4.5 protein (preactin) and not with band 3 protein. Both CB binding and transport function of the reconstituted transporters were resistant to trypsin but susceptible to chymotrypsin digestion. However, both trypsin and chymotrypsin treatment of unsealed ghosts completely eliminated the CB labeling and transport function of the glucose transporter. In our reconstitution system the glucose transporters maintained a normal asymmetrical (right-side-out) orientation and good transport function. A specific monoclonal antibody against the glucose transporter inhibited CB labeling of the transporters on unsealed ghosts. This was not found with the reconstituted system; however, after freeze-thawing there was a significant inhibition of CB binding by the antibody. These findings suggest that the CB-binding site of the reconstituted transporter is on the inner side of the proteoliposomes.     

Acute actions of 1,25-dihydroxy-vitamin D3 in normal man: effect on calcium and parathyroid status.

The present study was undertaken to evaluate the acute effect of 1,25-dihydroxy-vitamin D3 (1,25 (OH)2D3) on serum Ca, P and immunoreactive parathyroid (iPTH) and urinary Ca, P. and cyclic AMP. In 8 normal subjects, samples were collected over intervals of 30 to 60 min during a control day and on a treatment day following oral ingestion of 1,25(OH)2D3, 2.7 microgram. For the entire group there were no significant changes in serum Ca. P, iPTH or urinary P. Urinary Ca increased significantly 7 h after administration of 1,25(OH)2D3, and urinary cAMP decreased at 12 h. In 4 patients (group A). showing an increase in serum Ca by 0;2 to 0.4 mg/dl, serum iPTH decreased in 3, and the decrease in urinary cAMP appeared sooner. Among 4 patients showing no change in serum Ca after 1,25(HO)2D3 (group B), 3 showed an increase in iPTH. These data document the early onset of action of 1,25(OH)2D3 following its administration to normal man; increments in urinary Ca provide the most sensitive index of its action. The data provide no support for the view that 1,25(OH)2D3 exerts any direct inhibitory effect on the secretion of parathyroid hormone.     

Immunohistochemical characterization of a monoclonal antibody to hyperplastic nodules induced in rat liver by chemical carcinogens

To investigate the specific phenotype of hyperplastic nodules (HPN) in rat liver, we produced a monoclonal antibody (HAM-6). HAM-6 was a member of the mouse IgG₁ class and was specific for hyperplastic nodules, as shown by cellular radioimmunoassay and immunohistochemical studies. The antigen recognized by HAM-6 was located in the rat HPN cell membrane. HAM-6 was also slightly reactive to rat hepatocellular carcinoma, but not to normal or fetal rat liver, other normal rat organs, human hepatocellular carcinoma, or human liver cirrhosis. That is, the antigen recognized by HAM-6 appeared to be differentiated and to occur during chemical carcinogenesis. HAM-6 may be a useful marker for the investigation of premalignant states in chemical carcinogenesis.     

Novel technique using intravascular ultrasound-guided guidewire cross in coronary intervention for uncrossable chronic total occlusions.

The experience of using a novel application of intravascular ultrasound (IVUS)-guided percutaneous coronary interventions for chronic total occlusions is reported in 2 cases. In the first case, an IVUS catheter was advanced into a side branch to identify the entry point of the major branch. In the second case, IVUS-guided penetration of the guidewire from the false lumen to the true lumen after causing a dissection was successful.     

A possible role of vitamin D receptors in regulating vitamin D activation in the kidney.

The vitamin D endocrine system is regulated reciprocally by renal 25-hydroxyvitamin D3 1 alpha- and 24-hydroxylases. Previously, we reported that renal proximal convoluted tubules, the major site of 1 alpha, 25-dihydroxyvitamin D3 production, have vitamin D receptors. In the presence of vitamin D receptors, renal proximal convoluted tubules cannot maintain the state of enhanced production of 1 alpha, 25-dihydroxyvitamin D3. To clarify this discrepancy, we proposed a working hypothesis for the reciprocal control of renal 25-hydroxyvitamin D3 1 alpha- and 24-hydroxylase activities. In rat models of enhanced renal production of 1 alpha, 25-dihydroxyvitamin D3, expression of vitamin D receptors and 25-hydroxyvitamin D3 24-hydroxylase mRNAs was strikingly suppressed in renal proximal convoluted tubules but not in the cortical collecting ducts. In vitamin D-deficient rats with up-regulated renal 25-hydroxyvitamin D3 1 alpha-hydroxylase activity, expression of vitamin D receptor mRNA in renal proximal convoluted tubules was also down-regulated, indicating that the down-regulation of vitamin D receptor mRNA is not the result of the enhanced production of 1 alpha, 25-dihydroxyvitamin D3. In Japanese quail models with up-regulated renal 25-hydroxyvitamin D3 1 alpha-hydroxylase activity by sex steroids, expression of vitamin D receptor mRNA was also down-regulated in the kidney but not in the duodenum. These results suggest that the down-regulation of vitamin D receptors plays a critical role in production of 1 alpha, 25-dihydroxyvitamin D3 in renal proximal convoluted tubules.     

Hepatocellular carcinoma with nonalcoholic steatohepatitis

Nonalcoholic steatohepatitis (NASH) was originally believed to be a benign disease. However, it has been recently revealed that NASH could lead to irreversible liver disease in some patients. We report an unusual case of hepatocellular carcinoma (HCC) in a 76-year-old man with NASH. He had no history of alcohol consumption, drug use, or blood transfusion. He was negative for all serological viral markers and autoantibodies. In addition, he was obese (body mass index [BMI], 30.75kg/m²) and had type 2 diabetes mellitus. A liver biopsy specimen showed moderate steatosis with necroinflammatory changes, ballooning degeneration, Mallory bodies, pericellular fibrosis, and evidence of nodular regeneration. He was diagnosed with NASH with cirrhosis. Simultaneously, a liver tumor, measuring 19mm in diameter, was detected in segment 6. A tumor biopsy specimen revealed well-differentiated HCC, and imaging modalities confirmed the characteristics of HCC. To our knowledge, ten patients who had HCC with NASH were reported. In all patients with NASH and HCC, cirrhosis was present. Patients with NASH and cirrhosis may progress to HCC, and regular screening, based on tumor markers and imaging modalities, is needed to detect HCC in patients with NASH and cirrhosis.     

Comparison of the effects of glimepiride and glibenclamide on adipose tissue tumour necrosis factor-alpha mRNA expression and cellularity

Aim: The aim of this study was to compare the effects of glimepiride and glibenclamide on tumour necrosis factor (TNF)‐α expression and adipocyte cellularity in spontaneously diabetic, obese rats. Methods: Eight‐week‐old male Otsuka Long‐Evans Tokushima Fatty (OLETF) rats were randomized to receive glimepiride, glibenclamide or control treatment for 12 weeks, after which TNF‐α mRNA levels, adipose tissue cellularity and physiological parameters were measured. Results: TNF‐α mRNA expression in retroperitoneal fat tissue was significantly greater in the glibenclamide group (2.2 ± 1.1), compared with the control group (0.9 ± 0.4; p < 0.05) or the glimepiride group (0.9 ± 0.2; p < 0.01). The mean fat‐cell area in retroperitoneal fat tissue was increased at study endpoint in the glibenclamide group (13 764 ± 7036 µm²), compared with both the control and glimepiride groups (10 755 ± 6193 µm² and 11 317 ± 5646 µm² respectively; p < 0.05). Investigation of cellularity revealed a decrease in the frequency of small fat cells and an increase in the frequency of large fat cells in both the glibenclamide and glimepiride groups compared with the control group, with a greater increase in large fat cells in the glibenclamide group. At study endpoint, insulin and triglyceride values were significantly higher in the active treatment groups compared with the control group; however, insulin levels were significantly greater in glibenclamide‐treated animals compared with glimepiride‐treated animals. An oral glucose tolerance test performed at the end of the study showed that there were no significant differences among the three groups in terms of plasma glucose and insulin concentrations. Conclusions: This study suggests that although both glibenclamide and glimepiride may have a hypertrophisizing effect on fat cells in adipose tissues, this effect is greater with glibenclamide, leading to augmentation of TNF‐α mRNA expression and possible exacerbation of insulin resistance.     

Continuous infusion of prostaglandin E1 via the superior mesenteric artery can prevent hepatic injury in hepatic artery interruption through passive portal oxygenation

AIMS/BACKGROUND: Hepatic artery interruption (HAI) causes severe ischemic liver damage, especially following hepatopancreatobiliary surgery. In order to inhibit a decrease in oxygen delivery after HAI, continuous infusion of PGE1 via the superior mesenteric artery (SMA) was administered in pigs and changes in hepatic blood flow and oxygen delivery were investigated. Furthermore, its effectiveness in the prevention of liver injury was evaluated by histology and serum enzyme levels. METHODS: Animals were subjected to HAI without PGE1 infusion (control group n=6) and to continuous infusion of PGE1 (0.02 microg/kg/min) into the SMA (PGE1 group n=6). RESULTS AND CONCLUSION: PGE1 infusion via the SMA not only increased the portal blood flow but also elevated the oxygen content of the portal blood. The reduction in oxygen delivery to the liver was 50% in the control group, and only 13% in the PGE1 group. Serum aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) levels 24 h after HAI in the control group were 3415+/-1283 IU/L and 9839+/-2959 respectively while in the PGE1 group they were 939+/-426 IU/L and 5510+/-1545 IU/L respectively. Histological examination showed massive necrosis in the control group at 72 h but only focal liver cell necrosis in the PGE1 group. Based on this finding and the fact that this treatment can be performed easily and safely, continuous infusion of PGE1 via the SMA may be a useful intervention to prevent severe liver damage after hepatic artery interruption.