In vitro study on the transport of zinc across intestinal epithelial cells using Caco-2 monolayers and isolated rat intestinal membranes

The variety of physiologic and biologic functions of zinc is fascinating and could be applicable to medicine. Our previous studies demonstrated that the absorption of zinc after oral administration to rats is dose-dependent. In order to clarify the detailed mechanism of the dose-dependent in vivo absorption, the transport of zinc across intestinal epithelial cells was investigated using Caco-2 monolayers and isolated rat intestinal membranes. The permeation of zinc across Caco-2 monolayers is concentration-dependent, and both saturable and nonsaturable components are involved. The Michaelis constant and maximum transport rate for saturable transport are 11.7 μM and 31.8 pmol min(-1) cm(-2), respectively; the permeability coefficient for nonsaturable trasnport is 2.37×10(-6) cm s(-1). These parameters for permeation across membranes isolated from duodenum, ileum, and jejunum of rats are similar with those of Caco-2 cells. The comparison of the parameters for permeation across isolated intestinal membrane suggests that the major site of intestinal zinc absorption in rats is the duodenum. The maximum rate of zinc transport across the isolated intestinal membrane (V(max)) shows no correlation with mRNA expression of ZIP4, ZIP5 or ZnT1 in rats, but shows an inverse correlation with that of metallothioneins (MTs). This finding may be partly explained by the buffering role of metallothionein in intestinal absorption. The saturable transport of zinc is not simply determined only by the influx transporter, ZIP4, since three influx and efflux transporters are involved in the transport of zinc.     

Evaluation of Double Tract Reconstruction After Total Gastrectomy in Patients with Gastric Cancer: Prospective Randomized Controlled Trial

Background  The double tract (DT) method was compared with the Roux-en-Y (R-Y) method to identify the optimal reconstruction procedure after total gastrectomy for patients with gastric cancer. The DT reconstruction is as simple as the R-Y, and it can be safely performed even after total gastrectomy. However, these have been no studies evaluating the usefulness of DT reconstruction in comparison to R-Y reconstruction. Methods  A group of 44 patients with gastric cancer were intraoperatively randomized for R-Y (n = 23) or DT reconstruction (n = 21) after total gastrectomy (TG). Body weight, food intake, nutritional conditions, and quality of life (QOL) were determined at 3 and 12 months after the operation. This study is registered with ClinicalTrials.gov, no. NCT00746161. Results  Food intake significantly decreased soon after the operation. No differences were observed between the DT and R-Y groups. The body weight decreased throughout the ensuing period (P < 0.05) and thereafter gradually recovered. However, no differences were observed between the two groups. Among the nutritional laboratory parameters, serum prealbumin, retinol-binding protein, total cholesterol, and triglyceride were decreased soon after the operation. The changes of those parameters were not substantially different between the two groups. The postoperative QOL was evaluated, and no differences were observed between those groups. Conclusions  There were no particular advantages in the DT method after TG in comparison to the simple R-Y method in terms of body weight, QOL, and nutritional conditions, suggesting that the DT method might not be recommended after TG for patients with gastric cancer.     

Atrial fibrillation ablation with esophageal cooling with a cooled water-irrigated intraesophageal balloon: a pilot study

Introduction: A left atrioesophageal fistula is an uncommon but devastating complication that may occur during atrial fibrillation (AF) ablation, and may be due to thermal injury occurring during the radiofrequency (RF) ablation. We examined the feasibility of an esophageal cooling (ECO) method using a cooled water-irrigated intraesophageal balloon (IB).
Methods and Results: Eight patients with drug-refractory AF underwent RF catheter ablation to encircle the ipsilateral pulmonary veins. During the RF ablation at the posterior left atrium, the esophageal lumen was cooled using a 9-Fr. IB catheter with a balloon length of 40 mm and diameter of 10 mm, in which cooled water, with a water temperature of 4.5 ± 3.1 °C, was irrigated while the luminal esophageal temperature (LET) was measured with an intraesophageal probe placed at a site close to the tip of the ablation catheter. In the control, the LET increased from 36.4 ± 0.8 °C to 40.5 ± 1.7 °C within 26.1 ± 8.2 seconds during 3.9 ± 1.2 RF energy applications, whereas with the ECO the LET decreased to 30.2 ± 2.9 °C at baseline (P<0.01 vs control), and increased only to 33.5 ± 2.9 °C (P<0.01 vs control) at most, within 30 seconds during 3.9 ± 1.2 RF energy applications. All pulmonary veins were successfully isolated in all patients without any complications. During a follow-up period of 3.1 ± 1.2 months, no esophageal injuries were observed and all but one patient have been free from any symptoms.
Conclusions: Use of an IB successfully lowers LET. This might have the potential of preventing esophageal injury, although further study is required.     

Ten-second endoscopic breath test using a 20-mg dose of 13C-urea to detect Helicobacter pylori infection

BACKGROUND/AIMS: Attempts to improve the 13C-urea breath test (UBT) have focused on decreasing the amount of substrate used and reducing the duration of the test. To render the test less expensive and more convenient, we designed a more rapid and less expensive endoscopic UBT with a low dose of 20 mg and a shortened measurement time. METHODOLOGY: A total of 178 patients who underwent diagnostic upper endoscopy were enrolled. At endoscopy, 150 mL of intragastric gas sample were collected through a biopsy channel. Following inflation with air, 20 mL of water containing 20 mg of 13C-urea were sprayed onto the gastric mucosa using a spraying instrument. After 10 seconds, a gastric gas sample was collected again. The standard UBT was performed after 3-10 days. RESULTS: The delta13CO2 values of intragastric samples in H. pylori-positive patients and H. pylori-negative patients were 76.7 +/- 132.9 per thousand and 1.6 +/- 1.2 per thousand, respectively. With intragastric samples, the maximum sensitivity and specificity of intragastric samples were 83.7% and 100% with cut-off point of 8 per thousand, respectively. CONCLUSIONS: Ten-second endoscopic UBT using a 20-mg dose of 13C-urea is a rapid, inexpensive, and accurate method for the detection of H. pylori infection in clinical practice.     

Endoscopic 13C-urea breath test for detection of Helicobacter pylori infection after partial gastrectomy

BACKGROUND/AIMS: It is difficult to interpret the results of 13C-urea breath test (UBT) in gastrectomy patients because the test urea may pass through the stomach faster. The aim of this study is to evaluate the efficacy of the modified endoscopic UBT for detection of Helicobacter pylori (H. pylori) infection in the residual stomach. METHODOLOGY: An endoscopic UBT was performed in 44 patients who had undergone partial gastrectomy. At endoscopy, 20 mL of water containing 100mg of 13C-urea were sprayed onto the gastric mucosa and an intragastric gas sample was immediately collected through the biopsy channel. Breath samples were collected at 20 min after spraying 13C-urea. RESULTS: The intragastric delta13CO2 value in H. pylori-positive patients was significantly higher than those of 20-minute breath samples. The maximum sensitivity and specificity of intragastric samples were 97% and 100% with cutoff point of 5 per thousand, respectively. The sensitivity and specificity of breath samples at 20 min were 71.4% and 66.7% with cutoff point of 0.6 per thousand, respectively. CONCLUSIONS: An endoscopic UBT was superior to a standard UBT to detect H. pylori infection after partial gastrectomy.     

Anesthetic management of surgical intervention for contralateral pneumothorax after left pneumonectomy

A 61-year-old man who had undergone left pneumonectomy 7 years before for lung cancer was scheduled for thoracoscopic partial pulmonary resection of the right lung because of pneumothorax. Anesthesia was induced with propofol and maintained with sevoflurane and thoracic epidural block. He was monitored with electrocardiogram, direct arterial pressure, pulse oximetry and capnogram. Arterial blood gas sampling was done as required. During the operation, ventilation was maintained with mechanical and intermittent manual ventilation. Hemodynamic status was stable and intra- and post-operative course was uneventful. PCPS, ECLS, CVC and PAC were not required. A successful and satisfactory anesthetic management was accomplished by good cooperation between anesthesiologists and surgeons.     

Training of endotracheal intubation for an emergency medical technician and three cases of endotracheal intubation during emergency situation

It is said that airway management is an important part of lifesaving at the prehospital care for a seriously ill emergency patient. We performed the training of endotracheal intubation for an emergency medical technician, and in this report we discussed the results of trainings and examined 3 cases of endotracheal intubation in the emergency situation after training. Various kinds of problem arose through this training, for example, difficulty to get the consent from patients, overlap of a case for clinical resident and emergency medical technician, large responsibility of the anesthesiologist as a teaching staff. In addition, there may be no useful case for lifesaving at the emergency situation in 3 cases of endotracheal intubation. We consider that it may be difficult, but possibility cannot deny if endotracheal intubation by emergency medical technicians contribute to lifesaving rate improvement from viewpoint of prehospital care.     

Akt1 in murine chondrocytes controls cartilage calcification during endochondral ossification under physiologic and pathologic conditions

Objective

To examine the role of the phosphoinositide‐dependent serine/threonine protein kinase Akt1 in chondrocytes during endochondral ossification.

Methods

Skeletal phenotypes of homozygous Akt1‐deficient (Akt1^−/−) mice and their wild‐type littermates were compared in radiologic and histologic analyses. An experimental osteoarthritis (OA) model was created by surgically inducing instability in the knee joints of mice. For functional analyses, we used primary costal and articular chondrocytes from neonatal mice and mouse chondrogenic ATDC5 cells with retroviral overexpression of constitutively active Akt1 or small interfering RNA (siRNA) for Akt1.

Results

Among the Akt isoforms (Akt1, Akt2, and Akt3), Akt1 was the most highly expressed in chondrocytes, and the total level of Akt protein was decreased in Akt1^−/− chondrocytes, indicating a dominant role of Akt1. Akt1^−/− mice exhibited dwarfism with normal proliferative and hypertrophic zones but suppressed cartilage calcification in the growth plate compared with their wild‐type littermates. In mice with surgically induced OA, calcified osteophyte formation, but not cartilage degradation, was prevented in the Akt1^−/− joints. Calcification was significantly suppressed in cultures of Akt1^−/− chondrocytes or ATDC5 cells overexpressing siRNA for Akt1 and was enhanced in ATDC5 cells overexpressing constitutively active Akt1. Neither proliferation nor hypertrophic differentiation was affected by the gain or loss of function of Akt1. The expression of ANK and nucleotide pyrophosphatase/phosphodiesterase 1, which accumulate pyrophosphate, a crucial calcification inhibitor, was enhanced by Akt1 deficiency or siRNA for Akt1 and was suppressed by constitutively active Akt1.

Conclusion

Our findings indicate that Akt1 in chondrocytes controls cartilage calcification by inhibiting pyrophosphate during endochondral ossification in skeletal growth and during osteophyte formation in OA.

     

Analysis of the correlation with KRAS gene mutation status and the benefit of cetuximab plus irinotecan as third- line chemotherapy for the Treatment of unresectable metastatic colorectal cancer

Mutation of the KRAS gene in patients with metastatic colorectal cancer(mCRC)has been established as a predictive marker of poor response to anti-EGFR cetuximab. The Japanese Society of Medical Oncology recommends that the KRAS mutation status at codon 12 and codon 13 should be genotyped by direct-sequencing or allele-specific PCR. In this study, we tested the point mutation of codon 12 and 13 in the KRAS gene by Luminex(xMAP)flow cytometry with sequence-specific oligonucleotide probes for 39 out of 64 unresectable mCRC patients enrolled from Sep 2008 to Oct 2009, who were administered cetuximab in combination with irinotecan(CPT-11)as third-line therapy. We retrospectively analyzed the relationship between KRAS mutation status and responses to combination therapy. Mutations in the KRAS gene were detected in 38. 5% of cases(codon12: 73%, codon 13: 27%), and the median follow-up time was 8. 2 months(range, 1. 4-15. 2 months). The response rates for patients with KRAS wild-type and patients with KRAS mutations were 33. 3%(95%CI 14. 5-52. 2%)and 0%(p=0. 015); the disease control rates were 75%(95%CI 57. 7-92. 3%)and 40%(95%CI, 15. 2-64. 8%; p=0. 044); the median TTF was 7 months(95%CI 4. 6-9. 3)and 2. 3 months(95%CI 1. 3-3. 2; p=0. 0007), and the median OS was 12. 9 months(95%CI 6. 7-19. 1)and 10. 8 months(95%CI 5. 0-16. 7; p=0. 15), respectively. Therefore, we concluded that the KRAS mutation in mCRC is a predictive factor for the lack of response to combination therapy with cetuximab plus CPT- 11, as reported in previous clinical studies.