Transplantation of bone marrow stromal cell-derived Schwann cells promotes axonal regeneration and functional recovery after complete transection of adult rat spinal cord

The aim of this study was to evaluate whether transplantation of Schwann cells derived from bone marrow stromal cells (BMSC-SCs) promotes axonal regeneration and functional recovery in completely transected spinal cord in adult rats. Bone marrow stromal cells (BMSCs) were induced to differentiate into Schwann cells in vitro. A 4-mm segment of rat spinal cord was removed completely at the T7 level. An ultra-filtration membrane tube, filled with a mixture of Matrigel (MG) and BMSC-SCs (BMSC-SC group) or Matrigel alone (MG group), was grafted into the gap. In the BMSC-SC group, the number of neurofilament- and tyrosine hydroxylase-immunoreactive nerve fibers was significantly higher compared to the MG group, although 5-hydroxytryptamine- or calcitonin gene-related peptide-immunoreactive fibers were rarely detectable in both groups. In the BMSC-SC group, significant recovery of the hindlimb function was recognized, which was abolished by retransection of the graft 6 weeks after transplantation. These results demonstrate that transplantation of BMSC-SCs promotes axonal regeneration of lesioned spinal cord, resulting in recovery of hindlimb function in rats. Transplantation of BMSC-SCs is a potentially useful treatment for spinal cord injury.     

Oxygenated right ventricular assist device with a percutaneous dual-lumen cannula as a bridge to lung transplantation

BackgroundOxygenated right ventricular assist device (oxyRVAD) placement has become more streamlined with the introduction of the dual-lumen pulmonary artery cannula. Peripherally cannulated oxyRVAD may provide oxygenation support with right heart support as an alternative to venoarterial extracorporeal membrane oxygenation (ECMO) as a bridge to lung transplantation.MethodsA single-institution, retrospective analysis was performed on patients placed on oxyRVAD with a dual-lumen pulmonary artery cannula with the intention of bridging to lung transplantation in 2019.ResultsFour patients with idiopathic pulmonary fibrosis were placed on oxyRVAD as a bridge to transplantation. Two patients were extubated and ambulated while waiting for a lung offer, and two patients required conversion to venoarteriovenous ECMO (VAV ECMO) from oxyRVAD. The median waiting time for extracorporeal life support (ECLS) was 42 h. All patients underwent double lung transplantation. Two patients stayed on oxyRVAD, and one patient was placed on venovenous ECMO (VV ECMO) after transplantation. Primary graft dysfunction score at 72 h after transplantation was grade 1 in three patients and grade 3 in one patient.ConclusionsPeripherally cannulated oxyRVAD with percutaneous dual-lumen venous cannula could be an ambulatory bridge for lung transplantation. It is unknown whether oxyRVAD is feasible as a long-term bridge to lung transplantation.     

Prone positioning improves distribution of pulmonary perfusion: noninvasive magnetic resonance imaging study in healthy humans

The purpose of this study was to evaluate the effects of prone positioning on pulmonary perfusion using flow-sensitive alternating inversion recovery (FAIR), a noninvasive magnetic resonance imaging technique that requires no contrast medium. Seven healthy volunteers were studied in the supine and prone positions under three respiratory conditions: normal breathing of room air, unassisted breathing of 45% O₂, and controlled mechanical ventilation (CMV) with positive end-expiratory pressure. Signal intensities (SIs) were obtained from ventral, middle, and dorsal regions on sagittal lung images and dependent/nondependent SI ratios were calculated to evaluate pulmonary perfusion distribution. In the supine position, SIs increased significantly from the ventral to dorsal region under all three respiratory conditions and prone positioning inverted the perfusion distribution under all conditions. Right lung SI ratios were 2.34 ± 0.29, 2.74 ± 0.66, and 2.42 ± 0.73 in the supine position and 1.68 ± 0.48, 1.78 ± 0.36, and 1.92 ± 0.21 in prone for room air, 45% O₂, and CMV, respectively. The difference between supine and prone positions was statistically significant. The left lung showed a similar pattern and the difference was significant only under CMV. No difference was observed between the different respiratory conditions in both lungs. This study demonstrated that the distribution of pulmonary perfusion was more uniform in prone than in the supine position.     

The immunomodulatory effect of cryopreservation in rat tracheal allotransplantation.

BACKGROUND: Cryopreservation is one solution to the problem of donor organ deficit. To investigate the effect of cryopreservation on tracheal allografts, we performed 2 experiments in rats. METHODS: In Experiment 1, we assessed second-set graft rejection. Two weeks after primary heterotopic transplantation (Group 1, fresh isografts; Group 2, fresh allografts from Lewis rats; and Group 3, cryopreserved allografts from Lewis rats; n = 5, respectively), each animal underwent secondary heterotopic grafting with isografts and allografts from Lewis and Wistar Furth rats (n = 5, respectively). Four weeks after the secondary transplantation, all grafts were retrieved for histologic analysis. In Experiment 2, we assessed the long-term results of allograft cryopreservation, without immunosuppression therapy. Six months after transplantation of fresh (Group 4) and cryopreserved (Group 5) allografts, the tracheal segments (each group, n = 5) were histologically evaluated. RESULTS: In Experiment 1, only the secondary allografts from Lewis rats in Group 2 did not maintain lumen structure and often showed dislocated or destroyed cartilage. Second-set graft rejection was specifically recognized in Group 2, but not in Group 1 or 3. In Experiment 2, the cryopreserved allografts appeared almost normal and lumen rigidity was preserved 6 months after transplantation. These allografts were superior to the fresh allografts in patency and in cartilage dislocation and mononuclear cell infiltration scores, but not in the viable chondrocyte ratio. CONCLUSIONS: We conclude that cryopreservation may produce successful long-term results because of its immunomodulatory effect on tracheal allografts.     

Expression of a novel PDGF isoform, PDGF-C, in normal and diseased rat kidney

Platelet-derived growth factor-C (PDGF-C) is a new member of the PDGF family. Its expression in normal and diseased kidney is unknown. Rabbit antisera were generated against human full-length, core domain, and mouse PDGF-C, and their specificity was confirmed by Western blot analyses. Renal PDGF-C expression was analyzed by immunohistochemistry in normal rats (n = 8), mesangioproliferative anti-Thy 1.1 nephritis (n = 4 each at days 1, 4, 6, and 85), passive Heymann nephritis (PHN, n = 4), puromycin nephrosis (PAN, n = 2), Milan normotensive rats (MN, n = 2), and obese Zucker rats (n = 3). PDGF-C expression was also studied in anti-Thy 1.1 rats treated with PDGF-B aptamer antagonists (n = 5) or irrelevant control aptamers (n = 5). PDGF-C was constitutively expressed in arterial smooth muscle cells and collecting duct epithelial cells. Mesangial PDGF-C was markedly upregulated in anti-Thy 1.1 nephritis in parallel with the peak mesangial cell proliferation. Furthermore, PDGF-CC acted as a potent growth factor for mesangial cells in vitro. Inhibition of PDGF-B via specific aptamers reduced the injury in anti-Thy 1.1 nephritis but did not affect the glomerular PDGF-C overexpression or the mitogenicity of PDGF-CC in vitro. In PHN, PAN, and obese Zucker rats, glomeruli remained negative for PDGF-C despite severe glomerular injury. PDGF-C localized to podocytes at sites of focal and segmental sclerosis in MN. Interstitial PDGF-C expression was increased at sites of fibrosing injury in obese Zucker rats. The use of the different antisera resulted in virtually identical findings. It is concluded that PDGF-C is a novel mesangial cell mitogen that is constitutively expressed in the kidney and specifically upregulated in mesangial, visceral epithelial, and interstitial cells after predominant injury to these cells. PDGF-C may therefore be involved in the pathogenesis of renal scarring.     

Feasibility of Induction Chemotherapy Using Bronchial Arterial Infusion for Locally Advanced Non-Small Cell Lung Cancer: A Pilot Study

Purpose: We examined the feasibility and effectiveness of bronchial arterial infusion (BAI) as induction chemotherapy before surgery for locally advanced non-small cell lung cancer (NSCLC). Methods: Eighteen patients with locally advanced NSCLC were given BAI consisting of cis-diamminedichloroplatinum (CDDP) (50–100 mg/m²) as induction chemotherapy before surgery (induction BAI). Six patients with clinical stage IIIA cancer had bulky N2 metastatic lymph nodes, and 12 patients with clinical stage IIIB cancer had T4 disease. Results: Of the 18 patients, 12 (67%) showed a partial response to the BAI therapy. Standard pulmonary resection was performed in 5 patients, pulmonary resection with the combined resection of adjacent organs was performed in 10 patients, and pulmonary resection with carinal resection and reconstruction was performed in 3 patients. Complete resection was possible in 14 patients (78%). There were no serious BAI therapy-related complications or postoperative deaths. The 5-year survival rate of the 18 patients was 35.7% and the median survival time (MST) was 19.4 months. Survival was better when complete resection was achieved after the induction BAI, especially in patients with stage IIIB (T4) disease. Conclusion: Based on our preliminary findings, BAI with CDDP as induction chemotherapy is feasible and may be an effective therapeutic modality for locally advanced NSCLC. Received: July 26, 2001 / Accepted: March 5, 2002     

Laparoscopic rectal surgery for middle and lower rectal cancer

Background  

The usefulness of laparoscopic low anterior resection for middle and lower rectal cancer remains controversial.     

Safety and Feasibility of Laparoscopic Intersphincteric Resection for Very Low Rectal Cancer

Background

Laparoscopic surgery has been reported to be one of the approaches for total mesorectal excision (TME) in rectal cancer surgery. Intersphincteric resection (ISR) has been reported as a promising method for sphincter-preserving operation in selected patients with very low rectal cancer.

Methods

From July 2005 to December 2008, 35 patients with very low rectal cancer underwent laparoscopic TME with ISR. The results were compared retrospectively with those of previous open TME with ISR.

Results

Conversion to open surgery was necessary in one (3%) patient. The median operation time was 293 min and median estimated blood loss was 40 ml. The pelvic plexus was completely preserved in 32 patients. There was no mortality. Postoperative complications occurred in three (9%) patients. The median length of postoperative hospital stay was 17 days. Macroscopic complete mesorectal excision was achieved in all cases. Complete resection (R0) was achieved in 34 patients. Clinical lymph node stage, operation time, and blood loss were significantly different between the laparoscopic group and open group, but the differences of other factors were not statistically significant.

Conclusions

Laparoscopic TME with ISR is technically feasible and a safe alternative to laparotomy with favorable short-term postoperative outcomes.     

Treatment recommendations for adrenal metastasis of non-small cell lung cancer

To evaluate the optimum treatment strategy for metastatic adrenal tumors derived from non-small cell lung cancer (NSCLC), we retrospectively analyzed 17 consecutive cases (8 resection cases: 4 synchronous and 4 metachronous: 9 non-resection cases: 3 synchronous and 6 metachronous) who received surgical resection for NSCLC. The patients included 12 males and 5 females with a mean age of 63.9 years. Of these, 9, 3, 2, 2, and 1 patient (s) were diagnosed as having adenocarcinoma, squamous cell carcinoma, pleomorphic carcinoma, large cell carcinoma, and adenosquamous cell carcinoma, respectively. The mean interval after lung resection and treatment of metachronous adrenal metastasis was 9.9 months. The mean time to progression from treatment of metachronous adrenal metastasis to disease progression was 8.9 months. A survival analysis showed no significant prognostic difference between the patient age, gender, pathological stage, synchronous/metachronous classification, CEA, and site of metastases. However, patients who received an adrenalectomy had a more favorable prognosis. The 2-year survival of patients following resection versus those who did not undergo a resection for adrenal metastasis was 62.5 and 22.8%, respectively. These data indicate that metastatic adrenal tumors should be resected if the patient can tolerate surgery after appropriate selection.