Sodium hydroxide based non-detergent decellularizing solution for rat lung

Lung transplantation is the last option for the treatment of end stage chronic lung disorders. Because the shortage of donor lung organs represents the main hurdle, lung regeneration has been considered to overcome this hurdle. Recellularization of decellularized organ scaffold is a promising option for organ regeneration. Although detergents are ordinarily used for decellularization, other approaches are possible. Here we used high alkaline (pH12) sodium hydroxide (NaOH)-PBS solution without detergents for lung decellularization and compared the efficacy on DNA elimination and ECM preservation with detergent based decellularization solutions CHAPS and SDS. Immunohistochemical image analysis showed that cell components were removed by NaOH solution as well as other detergents. A Collagen and GAG assay showed that the collagen reduction of the NaOH group was comparable to that of the CHAPS and SDS groups. However, DNA reduction was more significant in the NaOH group than in other groups (p < 0.0001). The recellularization of HUVEC revealed cell attachment was not inferior to that of the SDS group. Ex vivo functional analysis showed 100% oxygen ventilation increased oxygen partial pressure as artificial hemoglobin vesicle-PBS solution passed through regenerated lungs in the SDS or NaOH group. It was concluded that the NaOH-PBS based decellularization solution was comparable to ordinal decellularizaton solutions and competitive in cost effectiveness and residues in the decellularized scaffold negligible, thus providing another potential option to detergent for future clinical usage.

Transplantation of bioengineered rat lungs recellularized with endothelial and adipose-derived stromal cells

Bioengineered lungs consisting of a decellularized lung scaffold that is repopulated with a patient's own cells could provide desperately needed donor organs in the future. This approach has been tested in rats, and has been partially explored in porcine and human lungs. However, existing bioengineered lungs are fragile, in part because of their immature vascular structure. Herein, we report the application of adipose-derived stem/stromal cells (ASCs) for engineering the pulmonary vasculature in a decellularized rat lung scaffold. We found that pre-seeded ASCs differentiated into pericytes and stabilized the endothelial cell (EC) monolayer in nascent pulmonary vessels, thereby contributing to EC survival in the regenerated lungs. The ASC-mediated stabilization of the ECs clearly reduced vascular permeability and suppressed alveolar hemorrhage in an orthotopic transplant model for up to 3 h after extubation. Fibroblast growth factor 9, a mesenchyme-targeting growth factor, enhanced ASC differentiation into pericytes but overstimulated their proliferation, causing a partial obstruction of the vasculature in the regenerated lung. ASCs may therefore provide a promising cell source for vascular regeneration in bioengineered lungs, though additional work is needed to optimize the growth factor or hormone milieu for organ culture.

[Efficacy and safety of administration of low-dose unfractionated heparin (LDUH) for the prevention of pulmonary thromboembolism after surgery for lung cancer; the long term outcome]

We evaluated the efficacy and safety of the administration of low-dose unfractionated heparin(LDUH)for the prevention of pulmonary thromboembolism after lung cancer surgery. We operated on 206 patients with primary lung cancer for 8 years;128 males and 78 females, mean age:69.9±8.8 years. All patients were administrated LDUH 5,000 units every 12 hours from the operation day until the day when the patient could walk around the floor. No patients suffered from clinical pulmonary thromboembolism in this period. The duration of treatment was 4.6±2.6 days and the chest tube duration was 5.4±3.0 days. We experienced post-operative intra-thoracic bleeding in 2 patients during the previous 4 years. Based on this experience, we introduced new eligibility criteria;we discontinued LDUH administration on the operation day if diffuse adhesion in the thoracic cavity was observed at operation or intraoperative blood loss was over 500 ml. The dose of LDUH was decreased to 2,500 unit every 12 hours if the postoperative bleeding was over 400 ml on the operation day or the patient's body weight was less than 40 kg. After introduction of the new criteria, no severe bleeding complications occurred during the latter 4 years.

[Influence of preoperative antithrombotic therapy on clinicopathological parameters in patients with lung cancer]

Cancer is known to promote its own development/proliferation and protect itself against attacks from immune system cells by activating the blood coagulation system. However, antithrombotic therapy inhibits the blood coagulation system. We investigated the blood coagulation system-mediated influence of preoperative antithrombotic therapy on the clinicopathological parameters of lung cancer. In patients who underwent antithrombotic therapy, there was a significant association between prothrombin time-international normalized ratio (PT-INR and positive findings on a thoracic lavage cytodiagnosis (p = 0.02). In these patients, the proportion of those with positive findings on a thoracic lavage cytodiagnosis was significantly higher than in those who did not undergo antithrombotic therapy (P = 0.0003). These results suggest that cancer progression is promoted by antithrombotic therapy through the inhibition of the blood coagulation system.

[Association between hemostasis/coagulation-system parameters and clinicopathological factors in patients with primary lung cancer]

Previous studies have gradually clarified the relationship between cancer and blood coagulation disorder and its mechanism. Various studies have also reported the association between lung cancer and coagulation disorder. However, it is rare to measure most hemostasis/coagulation-system test parameters in clinical practice. In this study, we investigated the association of hemostasis/coagulation-system test parameters, such as the prothrombin time (PT), activated partial thromboplastin time (APTT), bleeding time, and platelet count, which are routinely measured as preoperative examination parameters in patients with lung cancer, with the histopathologically evaluated stage of lung cancer. Although the mean values of hemostasis/coagulation-system parameters in all subjects were within the normal ranges, there were significant changes with respect to the clinico-pathological factors, showing a specific tendency. In patients in whom the histopathological stage was advanced, the APTT was prolonged, or the platelet count was increased.

Preoperative assessment of liver metastasis originating from colorectal carcinoma: is super paramagnetic iron oxide particles-magnetic resonance imaging (SPIO-MRI) useful for screening?

BACKGROUND/AIMS

Recently, early detection of liver tumors has been possible with improvement of various imaging techniques, and practical selection of imaging is clinically necessary to distinguish metastatic liver carcinoma (MLC) from colorectal carcinoma.

METHODOLOGY

We retrospectively examined the diagnostic accuracy of enhanced computed tomography (eCT) and super paramagnetic iron oxide particles magnetic resonance imaging (SPIO-MRI) for 110 MLC lesions in 47 patients who underwent hepatic resection at a single Japanese cancer institute between 2000 and 2006. Sensitivity and positive predictive value (PPV) of both imaging techniques in comparison with resected specimens were analyzed. Fourteen cases were synchronous liver metastasis, which were resected simultaneously.

RESULTS

On a per patient basis, both eCT and SPIO-MRI showed a sensitivity of 85.1% (40 of 47 patients) and PPV was 100%, respectively. On a per lesion basis, a sensitivity of SPIO-MRI (98/110 lesions; 89%) tended to be higher than that of eCT (92 of 110 lesions; 84%), but not statistically different (p=0.32). PPV of SPIO-MRI (98 of 99 lesions; 99%) was not different from that of eCT (92 of 93; 99%). Twelve lesions in 7 patients that were not detected by both imaging methods were small lesions. PPV for liver cyst and non-timorous lesions was 99% by both imaging methods. Two liver cysts could be clearly diagnosed by SPIO-MRI only.

CONCLUSIONS

We found no superiority of diagnosis with SPIO-MRI, which may not be conceptually useful for preoperative screening for MLC from colorectal carcinomas. SPIO-MRI may be useful to detect non-cancerous lesions as an adjuvant diagnostic tool with eCT.

Resection of segments 4, 5 and 8 for a cystic liver tumor using the double liver hanging maneuver

To achieve complete anatomic central hepatectomy for a large tumor compressing surrounding vessels, transection by an anterior approach is preferred but a skillful technique is necessary. We propose the modified technique of Belghiti's liver hanging maneuver (LHM). The case was a 77-year-old female with a 6-cm liver cystic tumor in the central liver compressing hilar vessels and the right hepatic vein. At the hepatic hilum, the spaces between Glisson's pedicle and hepatic parenchyma were dissected, which were (1) the space between the right anterior and posterior Glisson pedicles and (2) the space adjacent to the umbilical Glisson pedicle. Two tubes were repositioned in each space and ‘double LHM’ was possible at the two resected planes of segments 4, 5 and 8. Cut planes were easily and adequately obtained and the compressed vessels were secured. Double LHM is a useful surgical technique for hepatectomy for a large tumor located in the central liver.

Marked improvement with sildenafil in a patient with idiopathic pulmonary arterial hypertension unresponsive to beraprost and sarpogrelate

We report a 16-year-old man with severe heart failure due to idiopathic pulmonary arterial hypertension (IPAH). The patient was initially treated with a combination of beraprost, a prostacyclin analog, and sarpogrelate, a serotonin receptor inhibitor. However, he was unresponsive to the treatment. We then changed the treatment to sildenafil, and his condition dramatically improved. Sildenafil has an immediate pulmonary vasodilator effect in patients already receiving vasodilators for IPAH.