Cord Blood-Derived Hematopoietic Stem/Progenitor Cells: Current Challenges in Engraftment, Infection, and Ex Vivo Expansion

Umbilical cord blood has served as an alternative to bone marrow for hematopoietic transplantation since the late 1980s. Numerous clinical studies have proven the efficacy of umbilical cord blood. Moreover, the possible immaturity of cells in umbilical cord blood gives more options to recipients with HLA mismatch and allows for the use of umbilical cord blood from unrelated donors. However, morbidity and mortality rates associated with hematopoietic malignancies still remain relatively high, even after cord blood transplantation. Infections and relapse are the major causes of death after cord blood transplantation in patients with hematopoietic diseases. Recently, new strategies have been introduced to improve these major problems. Establishing better protocols for simple isolation of primitive cells and ex vivo expansion will also be very important. In this short review, we discuss several recent promising findings related to the technical improvement of cord blood transplantation

イマチニブ ガ チョコウ シ チョウキ カンゼン カンカイ CR オ イジ シテ イル ショウチョウ GIST フクマク ハシュ サイハツ ノ 1レイ

We report the case of a patient with recurrent gastrointestinal stromal tumor （GIST） complicated with peritoneal dissemination who achieved long-term complete remission （CR） with imatinib mesylate therapy. A 64-year-old man was admitted to our hospital because of severe abdominal pain. Abdominal computed tomography （CT） showed free air and an intra-abdominal abscess. Perforation of the small intestine was diagnosed, and an emergency operation was performed. Two adjacent tumors （each,6cm in size）, one of which was ruptured, were found by laparotomy in the jejunum and as a peritoneal dissemination. Jejunojejunostomy with the two adjacent tumors was performed and as much of the disseminated tumors as possible were resected. Histopathological analysis indicated a high-risk GIST of the small intestine. Abdominal CT at 1.5 years after the initial operation showed multiple recurrent tumors due to peritoneal dissemination. The patient subsequently received imatinib mesylate therapy at 400mg/day, and 5 months later, abdominal CT showed no evidence of tumor recurrence. DNA analysis of the tumor revealed an exon 11 mutation in the c-kit gene. The patient continues to receive imatinib mesylate therapy （400mg/day）, and CR of the recurrent tumors has been maintained for 8 years and 7 months

チョウヘイソク オ キタシタ シキュウ ケイガン ショウチョウ テンイ ノ 1レイ

We report a patient of a metastatic small intestinal tumor from uterine cervical cancer. A 76 year-old woman admitted to our hospital because of dyspnea. She showed progressive acute renal failure with pulmonary edema. Abdominal CT showed an advanced uterine cervical tumor and bilateral hydronephrosis. She was treated with temporary hemodialysis and tube nephrostomy. 1 week after admission, she presented with severe nausea, vomiting and rapidly progressive abdominal distension. We diagnosed her as strangulated ileus of the small intestine and she underwent an emergency operation. Laparotomy revealed an isolated tumor of the ileum and dilatation of the proximal small intestine without peritoneal dissemination, and a partial resection of the ileum was performed. Histopathological findings showed that the tumor was composed of squamous cell carcinoma cells, indicating that it was metastasis from uterine cervical cancer. Metastatic small intestinal tumor from primary uterine cervical cancer is very rare. To our knowledge, only 5 cases have been reported in Japan, including the present case

センコウセイ フクマクエン デ ハッショウ シタ ショウチョウ gastrointestinal stromal tumor ノ 1レイ

We report a case of gastrointestinal stromal tumor (GIST) with perforation in the jejunum and peritoneal dissemination. A 64 year-old man admitted our hospital with severe abdominal pain. He had findings of panperitonitis and the abdominal CT examination revealed free air and an intraabdominal abscess. We suspected perforation of the small intestine and operated. There were two adjacent tumors (6cm in diameter each) of the jejunum and peritoneal dissemination, and one of them was perforated. We performed a jejunojejunostomy and resected as all disseminated tumors as possible. Histopathological findings showed that the tumors were composed of spindle cell proliferation with three or four mitoses per high-power fields (HPF). Because tumor cell were positive for c-kit and CD34, and negative for alpha-smooth muscle actin and S-100 immunohistochemically, we diagnosed these tumors as “maligmant GIST of small intestine, uncommitted type”. Perforation of GIST is rare. Only 20 cases of GIST with peritonitis due to perforation have been reported in Japan, including the present case. Of 20 cases, 14 were small intestinal GIST. Small intestinal GIST should be recognized as a high-risk group of malignancy and perforation

Adenomatous Polyposis Coli on Microtubule Plus Ends in Cell Extensions Can Promote Microtubule Net Growth with or without EB1

In interphase cells, the adenomatous polyposis coli (APC) protein accumulates on a small subset of microtubules (MTs) in cell protrusions, suggesting that APC may regulate the dynamics of these MTs. We comicroinjected a nonperturbing fluorescently labeled monoclonal antibody and labeled tubulin to simultaneously visualize dynamics of endogenous APC and MTs in living cells. MTs decorated with APC spent more time growing and had a decreased catastrophe frequency compared with non-APC-decorated MTs. Endogenous APC associated briefly with shortening MTs. To determine the relationship between APC and its binding partner EB1, we monitored EB1-green fluorescent protein and endogenous APC concomitantly in living cells. Only a small fraction of EB1 colocalized with APC at any one time. APC-deficient cells and EB1 small interfering RNA showed that EB1 and APC localized at MT ends independently. Depletion of EB1 did not change the growth-stabilizing effects of APC on MT plus ends. In addition, APC remained bound to MTs stabilized with low nocodazole, whereas EB1 did not. Thus, we demonstrate that the association of endogenous APC with MT ends correlates directly with their increased growth stability, that this can occur independently of its association with EB1, and that APC and EB1 can associate with MT plus ends by distinct mechanisms

Molecular Cloning and Expression of Mn(2+)-Dependent Sphingomyelinase/Hemolysin of an Aquatic Bacterium, Pseudomonas sp. Strain TK4

We report here the molecular cloning and expression of a hemolytic sphingomyelinase from an aquatic bacterium, Pseudomonas sp. strain TK4. The sphingomyelinase gene was found to consist of 1,548 nucleotides encoding 516 amino acid residues. The recombinant 57.7-kDa enzyme hydrolyzed sphingomyelin but not phosphatidylcholine, phosphatidylserine, phosphatidylglycerol, phosphatidic acid, or phosphatidylethanolamine, indicating that the enzyme is a sphingomyelin-specific sphingomyelinase C. The hydrolysis of sphingomyelin by the enzyme was found to be most efficient at pH 8.0 and activated by Mn(2+). The enzyme shows quite a broad specificity, i.e., it hydrolyzed 4-nitrobenz-2-oxa-1,3-diazole (NBD)-sphingomyelin with short-chain fatty acids and NBD-sphingosylphosphorylcholine, the latter being completely resistant to hydrolysis by any sphingomyelinase reported so far. Significant sequence similarities were found in sphingomyelinases from Bacillus cereus, Staphylococcus aureus, Listeria ivanovii, and Leptospira interrogans, as well as a hypothetical protein encoded in Chromobacterium violaceum, although the first three lacked one-third of the sequence corresponding to that from the C terminus of the TK4 enzyme. Interestingly, the deletion mutant of strain TK4 lacking 186 amino acids at the C-terminal end hydrolyzed sphingomyelin, whereas it lost all hemolytic activity, indicating that the C-terminal region of the TK4 enzyme is indispensable for the hemolytic activity