Point mutation in kit receptor tyrosine kinase reveals essential roles for kit signaling in spermatogenesis and oogenesis without affecting other kit responses

The Kit receptor tyrosine kinase functions in hemato- poiesis, melanogenesis and gametogenesis. Kit receptor-mediated cellular responses include proliferation, survival, adhesion, secretion and differentiation. In mast cells, Kit-mediated recruitment and activation of phosphatidylinositol 3'-kinase (PI 3-kinase) produces phosphatidylinositol 3'-phosphates, plays a critical role in mediating cell adhesion and secretion and has contributory roles in mediating cell survival and proliferation. To investigate the consequences in vivo of blocking Kit-mediated PI 3-kinase activation we have mutated the binding site for the p85 subunit of PI 3-kinase in the Kit gene, using a knock-in strategy. Mutant mice have no pigment deficiency or impairment of steady-state hematopoiesis. However, gametogenesis is affected in several ways and tissue mast cell numbers are affected differentially. While primordial germ cells during embryonic development are not affected, Kit(Y719F)/Kit(Y719F) males are sterile due to a block at the premeiotic stages in spermatogenesis. Furthermore, adult males develop Leydig cell hyperplasia. The Leydig cell hyperplasia implies a role for Kit in Leydig cell differentiation and/or steroidogenesis. In mutant females follicle development is impaired at the cuboidal stages resulting in reduced fertility. Also, adult mutant females develop ovarian cysts and ovarian tubular hyperplasia. Therefore, a block in Kit receptor-mediated PI 3-kinase signaling may be compensated for in hematopoiesis, melanogenesis and primordial germ cell development, but is critical in spermatogenesis and oogenesis.

Transplantation of cryopreserved human embryonal carcinoma-derived neurons (NT2N cells) promotes functional recovery in ischemic rats

This study was designed to explore the efficacy of a human clone cell line as an alternative neural graft source and to validate the practice of cryopreservation and xenografting as logistical approaches toward conducting neural transplantation. We investigated the biological effects of transplanting cultured human neurons (NT2N cells) derived from a well-characterized embryonal carcinoma cell line into the brains of rats subjected to transient, focal cerebral ischemia induced by embolic occlusion of the middle cerebral artery. At 1 month and extending throughout the 6-month posttransplantation test period, ischemic animals that were transplanted with NT2N cells and treated with an immunosuppressive drug displayed a significant improvement in a passive avoidance task as well as a normalization of asymmetrical motor behavior compared to ischemic animals that received rat fetal cerebellar cell grafts or vehicle alone. Remarkably, cryopreserved NT2N cell grafts compared with fresh NT2N cell grafts, remained viable in the immunosuppressed rat brain and effective in producing behavioral recovery in immunosuppressed ischemic animals. The long-term viability of cryopreserved NT2N cell xenografts in vivo and their sustained effectiveness in promoting behavioral recovery suggest potential utilization of xenografting and cryopreservation as useful protocols for establishing clone cell lines as graft source in neural transplantation therapies for central nervous system disorders.

Salivary gland malignant myoepithelioma: a clinicopathologic and immunohistochemical study of ten cases

BACKGROUND

Malignant myoepithelioma (MME) of the salivary gland, also known as myoepithelial carcinoma, is rare and its biologic behavior has not been clarified fully.

METHODS

Ten cases of MME were analyzed for their clinicopathologic features and immunohistochemical characteristics, focusing on prognostic factors and tumor differentiation. In addition, six cases of benign myoepithelioma (BME) also were examined for comparison.

RESULTS

The ten patients with MME (3 men and 7 women) ranged in age from 48-81 years (mean, 61.9 years). Seven cases of MME arose in the parotid salivary gland, two in the submandibular salivary gland, and one in minor salivary glands of the soft palate. In the current series, the incidence of MME was 0.45% among 1945 cases of major salivary gland tumors. Seven cases of MME developed from a benign preexisting tumor (six in pleomorphic adenoma and one in BME). Four of nine patients with MME died of the disease and two patients developed a recurrence. It was shown that MMEs were comprised of one cell type or a combination of two cell populations; these included, in order of incidence, epithelioid, spindle, and plasmacytoid cells. Patients with MME with marked cellular pleomorphism and perineural invasion had a poor prognosis. Immunohistochemically, putative myoepithelial markers such as muscle actins, cytokeratin 14, vimentin, and calponin, and S-100 protein were expressed highly in MME. High and low molecular weight cytokeratins and epithelial membrane antigen also frequently were positive in MME. p53 expression was observed in five MME cases, four of which either recurred or were fatal. Cellular proliferative activity assessed by mitotic count and the Ki-67 labeling index was significantly higher in MME cases than in BME cases. In limited cases, such cellular proliferative activity was shown to have prognostic value. Ultrastructurally, the tumor cells displayed certain myoepithelial characteristics.

CONCLUSIONS

MME is a rare salivary gland tumor showing clinicopathologic diversity and presenting with various stages of myoepithelial differentiation. Histologic aggressiveness, marked cellular pleomorphism, p53 expression, and high cell proliferative activity were found to be correlated with a poor clinical outcome.

Gastric and intestinal phenotypic marker expression in gastric carcinomas and its prognostic significance: immunohistochemical analysis of 136 lesions

OBJECTIVE

It is well known that both gastric and intestinal phenotypic cell markers are expressed in gastric carcinomas, irrespective of their histologic type. However, the clinicopathologic significance of these expressions has not yet been clarified.

METHODS

We analyzed the correlations among gastric and intestinal phenotypic marker expression patterns of the tumor, clinicopathologic findings and the patient's outcome in 136 advanced gastric carcinomas.

RESULTS

Phenotypic marker expression was immunohistochemically evaluated using the monoclonal antibodies 45M1 (anti-human gastric mucin; HGM), CLH5 (anti-MUC6), Ccp58 (anti-MUC2) and 56C6 (anti-CD10). All tumors were classified as gastric (G), gastric and intestinal mixed (GI), intestinal (I) or unclassified (UC) phenotype. Of the 136 gastric carcinomas, 50 (36.8%), 56 (41.2%), 21 (15.4%) and 9 (6.6%) were classified as G, GI, I and UC phenotype, respectively. The G-phenotype tumors were associated with a higher rate of undifferentiated-type and infiltrative histology as compared with the I-phenotype tumors (p < 0.05 and p < 0.001, respectively). Furthermore, both univariate and multivariate analysis of survival revealed the G-phenotype tumor to be associated with a significantly poorer outcome than the I-phenotype tumor (p < 0.05).

CONCLUSION

Our present results indicate that the gastric and intestinal phenotypic marker expression pattern of tumors, determined by the combination of HGM, MUC6, MUC2 and CD10 expression, is prognostically useful for patients with gastric carcinoma.

Establishment and characterization of a culture system for enzymatically released rat dental pulp cells

To establish a cell culture system that reflects the dentin formation in dental pulp tissue, we used dental pulp cells enzymatically isolated from rat incisor teeth. During the 20-day culture period, the cells exhibited various phenotypes of the odontoblast differentiation process, from the immature stage to the terminal mineralization stage. The cells began to form the mineralized nodules from day 10, and the nodules became larger by day 20. Alkaline phosphatase (ALP)-positive cells surrounded the mineralized nodules. The ALP activity in the cell layers was maximal on day 5, and gradually decreased to day 20. The calcium content in the cell layers was very low by day 10, and significantly increased from day 15. Sulfated glycosamino-glycans (GAGs) contained in the cell layers increased by day 15, but the content then decreased by day 20. The dental pulp cells produced a small amount of osteocalcin that was released into the culture medium by day 10, and the amount secreted increased markedly from day 15. The expression of osteocalcin and parathyroid hormone/parathyroid hormone-related peptide (PTH/PTHrP) receptor mRNA was evident as early as day 5, and the expression of each gradually increased with the number of days in culture. Dentin matrix protein (Dmp1) mRNA gene transcripts were identified by use of the reverse transcription polymerase chain reaction (RT-PCR) in the cells throughout the culture period. The present results demonstrate that this culture system is useful for studying the differentiation process of the odontoblast-like cells.

Cerebral ischemia and CNS transplantation: differential effects of grafted fetal rat striatal cells and human neurons derived from a clonal cell line

Stroke mortality has declined over recent decades, prompting a demand for the development of effective rehabilitative therapies for stroke survivors. This effort has been facilitated by significant progress in replicating the behavioral and neuropathological changes of authentic human cerebral ischemia using relevant animal models. Since the rodent model of middle cerebral artery occlusion mimics several motor abnormalities seen in clinical cerebral ischemia, we have utilized this model to investigate treatment strategies for stroke. The present study explored the potential benefits of neural transplantation of fetal rat striatal cells or human neurons derived from a clonal embryonal carcinoma cell line to correct the abnormalities associated with cerebral ischemia. We report here that ischemia-induced behavioral dysfunctions were ameliorated by the neural grafts as early as 1 month post-transplantation. Of note, transplantation of human neurons induced a significantly more robust recovery than fetal rat striatal grafts. Thus, the logistical and ethical concerns about the use of fetal striatal cells for transplantation therapy can be eliminated by exploiting cell line-derived human neurons as alternative graft sources. Transplantation of human neurons has a therapeutic potential for treatment of behavioral deficits associated with cerebral ischemia.

Consequences of exclusive expression in vivo of Kit-ligand lacking the major proteolytic cleavage site

Membrane growth factors that are processed to produce soluble ligands may function both as soluble factors and as membrane factors. The membrane growth factor Kit-ligand (KL), the ligand of the Kit receptor tyrosine kinase, is encoded at the Sl locus, and mice carrying Sl mutations have defects in hematopoiesis, gametogenesis, and melanogenesis. Two alternatively spliced KL transcripts encode two cell-associated KL protein products, KL-1 and KL-2. The KL-2 protein lacks the major proteolytic cleavage site for the generation of soluble KL, thus representing a more stable cell-associated form of KL. We investigated the consequences of exclusive expression of KL-2 in vivo. The KL gene in embryonic stem cells was modified and KL exon 6 was replaced with a PGKneoNTRtkpA cassette by homologous recombination, and mice carrying the SlKL2 allele were obtained. SlKL2/SlKL2 mice had only slightly reduced levels of soluble KL in their serum, suggesting that in vivo KL-2 may be processed to produce soluble KL-2S. The steady-state characteristics of the hematopoietic system and progenitor numbers were normal, and the mutant animals were not anemic. However, mast cell numbers in the skin and peritoneum were reduced and the mutant animals displayed increased sensitivity to sublethal doses of gamma-irradiation. Therefore, KL-2 may substitute for KL-1 in most situations with the exception of the production of mast cells, and induced proteolytic cleavage of KL-1 to produce soluble KL may have a role in the regeneration of hematopoietic tissue after radiation injury.

Biologically active kit ligand growth factor is produced by mouse Sertoli cells and is defective in SId mutant mice

In order to define the role of Kit ligand (KL) growth factor encoded at the mouse steel (SI) locus in spermatogenesis, we have examined its production in Sertoli cells. As a measure KL growth factor bioactivity, the ability to support proliferation and maintenance of mast cells was used in co-culture with primary mouse Sertoli cells. On the sertoli cells derived from +/+ and Wv/Wv mice, +/+ mast cells proliferated and were supported for more than 2 weeks, but not W/Wv mast cells. In contrast, Sertoli cells from SId/SId mice could not support +/+ mast cell proliferation under similar conditions. The supportive effect required close-range interaction of Sertoli cells with cultured mast cells. These results indicate that Sertoli cells derived from +/+ and Wv/Wv but not SId/SId mutant mice produce biologically active KL growth factor as a membrane-bound form. The biologically active KL of Sertoli cells may also play an important role in germ cell growth and differentiation.

Inhibitory effect of polyoxotungstates on the production of penicillin-binding proteins and beta-lactamase against methicillin-resistant Staphylococcus aureus

In our continuous work on the enhancement of the antibacterial activity of beta-lactam antibiotics against the cells of methicillin-resistant Staphylococcus aureus (MRSA) strains by Keggin-structural polyoxotungstates and their lacunary species, Wells-Dawson, double-Keggin, and Keggin-sandwich polyoxotungstates are also found to be synergistic but highly cytotoxic. The coexistence of polylysine or protamine sulphate decreased the synergistic potency of the polyoxotungstates, due to their electrostatic interaction with negatively charged polyoxotungstates. Inductively coupled plasma atomic emission spectrometry (ICP) analysis of the polyoxotungstate-treated cells indicated that the polyoxotungstates uptaken in the cell are preferentially located at the membrane fraction with intact composition. The polyoxotungstates depressed not only the production of PBP2', but also the production of beta-lactamase which hydrolyzes beta-lactam antibiotics on the membrane. This leads to the synergistic effect of polyoxotungstates against the MRSA cells in the coexistence of beta-lactam antibiotics which have high affinities to PBPs 1-4. MRSA cells which were modified to be susceptible to beta-lactam antibiotics during incubation in the presence of polyoxotungstates recovered their resistance to beta-lactam antibiotics when they were subcultured in the absence of the polyoxotungstate.

Appraisal of a total meso-pancreatoduodenum excision with pancreaticoduodenectomy for pancreatic head carcinoma

BACKGROUND

The most significant prognostic factors for pancreatic head carcinoma (PHC) with pancreaticoduodenectomy (PD) are the resection margin and lymph node status. The curative surgical margin (R0) and complete clearance of regional lymph nodes contribute to the improvement of survival. To reduce microscopic residual tumor resection (R1) and achieve a complete lymphadenectomy around the superior mesenteric artery (SMA) when performing a PD for PHC, we propose a new concept of a total excision of the "meso-pancreatoduodenum." which consists of a cluster of the soft connective tissue along the inferior pancreaticoduodenal artery and the first jejunal artery.

METHODS

A total of 39 consecutive patients underwent a PD for PHC between May 2006 and August 2011 at Shimane University Hospital. Twenty-five patients received a standard PD (sPD), while 14 cases underwent a total meso-pancreatoduodenum excision (tMPDe) with PD.

RESULTS

The tMPDe procedure was performed safely without any intraoperative complications. The total number of lymph nodes dissected was 18 (median, range: 5-40) in the sPD and 26 (median, range: 13-50) in the tMPDe (p = 0.027). R0 resection was accomplished in 60% and 93% of patients with the sPD and tMPDe, respectively, resulting in a significant decrease in the R1 rate in the tMPDe (7%) compared to that in the sPD (40%) (p = 0.019). No loco-regional recurrence was found around the SMA in the tMPDe patients.

CONCLUSION

Our surgical technique, tMPDe, is safe and more radical when performing a PD and should be adopted when performing pancreatic surgery as a pathological cure for pancreatic head carcinoma.

The activating effects of bicarbonate on sperm motility and respiration at ejaculation

Mature porcine sperm preserved in the cauda epididymis are quiescent. At ejaculation, they are mixed with the seminal vesicle fluid containing HCO3- and are rapidly activated. The role of HCO3- on the sperm activation process at ejaculation was studied in vitro. HCO3- quickly increased the motility, respiration rate and cAMP content of the porcine epididymal sperm. The extent of activation was proportional to the pCO2 in the medium. The activating effect of HCO3- on the motility was observed even in the absence of fructose as well as in the presence of KCN. 8-Bromoadenosine 3',5'-cyclic monophosphate and theophylline showed similar activating effects to that of HCO3-. However, HCO3(-)-free seminal plasma, Ca2+, amino acids, intermediates of the Krebs cycle, substrates of respiration and increases in the intracellular pH, extracellular pH or ionic strength of the medium had no effect. Fructose sustained the active state of the sperm and gradually increased both the motility and respiration rate when the dose of HCO3- was low. The anion channel blocker enhanced the activating effect of HCO3-. These results suggest that, upon ejaculation, HCO3- is a unique activator in vivo which makes the quiescent sperm motile via the HCO3(-)-adenylate cyclase-cAMP system, to which an endogenous HCO3- derived from metabolic CO2 may be related.

Primary large-cell neuroendocrine carcinoma of the parotid gland: immunohistochemical and molecular analysis of two cases

Pulmonary large-cell neuroendocrine carcinoma (LCNEC) is a newly proposed clinicopathologic entity; a few cases of LCNEC have been reported in other sites, such as the uterine cervix and the thymus. In the salivary glands, LCNEC is extremely rare and is not recognized as a specific entity in the World Health Organization classification. We retrospectively reviewed from our files 1675 cases of surgically resected primary parotid gland tumors and found 2 cases of LCNEC that fulfilled the criteria of pulmonary LCNEC. These cases occurred in 72- and 73-year-old men who had short histories of enlarging parotid gland tumors. The tumors were composed of large cells that exhibited organoid, solid, trabecular, and rosette-like growth patterns with a high mitotic rate and a conspicuous tendency for necrosis. The tumor cells were polygonal and characterized by a moderate nuclear:cytoplasmic ratio, coarse chromatin, and conspicuous nucleoli. Immunohistochemical examination revealed that the tumor cells were positive for six general neuroendocrine markers, cytokeratin, p53, bcl-2, epidermal growth factor receptor, and cyclin D1. Markedly reduced expressions of p21Waf1 and p27Kip1 were also noticed. The Ki-67 labeling index was more than 50% in both cases. One case showed loss of heterozygosity at TP53 accompanied by a p53 gene point mutation. Loss of heterozygosity at chromosome 9p21 was detected in both cases; one was accompanied by a p16 gene silent point mutation. Both patients died of the disease, with recurrence 5 months and 4 years after surgery, respectively. These findings indicate that LCNEC is a rare but distinct salivary gland tumor with highly aggressive biologic behavior. Multiple alterations of cell cycle regulators and tumor suppressor genes may play an important role in presenting the biologic characteristics of this rare parotid gland tumor.

Synergistic effect of polyoxotungstates in combination with beta-lactam antibiotics on antibacterial activity against methicillin-resistant Staphylococcus aureus

The in vitro antibacterial effect of the combination of various polyoxometalates with beta-lactam antibiotics on methicillin-resistant Staphylococcus aureus (MRSA) strains is investigated by the use of both the National Committee for Clinical Laboratory Standards (NCCLS) disk method and the agar dilution method. Keggin-structural polyoxotungstates such as K7[PTi2W10O40].6H2O (5) and K7[BVW11O40].7H2O (8) and their lacunary species formulated by [XW11O39]n- and[XW9O34]n- potentiated the antibacterial activity of beta-lactam antibiotics such as oxacillin, piperacillin and cefazolin on MRSA with high selectivity. The depression of bacterial growth with the coexistence of polyoxotungstates and oxacillin was confirmed by the measurement of the bacterial turbidity at 660nm. Polyoxomolybdates and polyoxovanadates, on the other hand, exhibited hardly any synergistic effect in combination with oxacillin. The sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of the membrane proteins separated from MRSA revealed that polyoxotungstates depressed the formation of penicillin-binding protein 2'(PBP2'), an enzyme which is essential for cell wall construction in the MRSA growth. It is concluded that polyoxotungstates make the MRSA strains susceptible to beta-lactam antibiotics.

Synthesis and antifungal activities of R-102557 and related dioxane-triazole derivatives

Novel triazole compounds with a dioxane ring were synthesized. Condensation of the diol precursor 10 with various aromatic aldehydes 11-13 under acidic conditions afforded a series of dioxane-triazole compounds 14-16. The antifungal activities of the compounds 14-16 were evaluated in vivo in mice infection models against Candida and Aspergillus species. High activities were seen for the derivatives with one or two double bond(s) and an aromatic ring substituted with an electron-withdrawing group in the side chain. Among the derivatives, R-102557 (16R: Ar=4-(2,2,3,3-tetrafluoropropoxy)phenyl) showed excellent in vivo activities against Candida, Aspergillus and Cryptococcus species. It also showed high tolerance in a preliminary toxicity study in rats.

An intraductal papillary component is associated with prolonged survival after hepatic resection for intrahepatic cholangiocarcinoma

BACKGROUND

The outcome after surgery for intrahepatic cholangiocarcinoma (ICC) is dismal and data on long-term survival are not available. This study evaluated prognostic indicators and characteristic features of long-term survivors after hepatic resection for ICC.

METHODS

Thirty-one patients who had undergone hepatic resection for ICC were studied. Univariate and multivariate survival analyses of clinicopathological data included an intraductal papillary carcinoma component (IDPCC) in the tumour, which was defined as the histological demonstration of cancer cells growing in a papillary fashion into the lumen of the large bile duct.

RESULTS

The overall cumulative survival rate after hepatic resection for ICC was 51.2 per cent at 1 year and 24.5 per cent at 5 years, with a mean(s.d.) survival time of 11(4) months. The presence of IDPCC (P = 0.003), curative resection (P = 0.009) and the absence of perineural invasion (P = 0.040) were identified as favourable independent prognostic factors in multivariate analysis. Eight patients with IDPCC had a 5-year survival rate of 87.5 per cent and a mean(s.d.) survival time of 69(13) months. All seven patients who survived for more than 5 years after surgery had IDPCC, regardless of the gross appearance of the tumour.

CONCLUSION

An IDPCC in the tumour resulted in long-term survival after hepatic resection for ICC.

Lowered levels of bicarbonate in seminal plasma cause the poor sperm motility in human infertile patients

Both the adenylate cyclase activity and the motility of human sperm were stimulated by bicarbonate with the same concentration dependency. The correlation between bicarbonate levels in semen and the motility of sperm from the patients with male infertility was investigated. Bicarbonate in semen was found to originate mainly from the seminal vesicles, and a significant positive correlation was observed between bicarbonate levels and volume of semen. The motility of infertile sperm was also found to correlate positively to the seminal levels of bicarbonate. These results suggest that the lowered levels of bicarbonate in semen are at least in part responsible for the poor sperm motility in infertile patients, as a result of the failure in the activation of sperm adenylate cyclase.

Significance of involvement by squamous cell carcinoma of the ducts of esophageal submucosal glands. Analysis of 201 surgically resected superficial squamous cell carcinomas

BACKGROUND

Ductal involvement (DI) is often observed in superficial squamous cell carcinoma of the esophagus (SSCCE), defined as carcinoma with invasion limited to the submucosa. The purpose of this study was to clarify the clinicopathologic significance of DI in SSCCE.

METHODS

Two hundred one surgically resected lesions from 140 patients with SSCCE were examined histopathologically. Clinicopathologic factors, such as macroscopic type, tumor location, maximum tumor size, depth of invasion, lymphatic and blood vessel permeation, lymph node metastasis, and prognosis, were examined to investigate the association between these factors and the presence of DI.

RESULTS

Of the 201 SSCCE lesions, 43 (21.3%) had 152 DIs (1-32 DIs per lesion). The DI always remained in situ, and there were no tumors showing submucosal invasion through the DI. As for the relation between clinicopathologic factors and the presence of DI, multivariate analysis showed only maximum tumor size to correlate with the presence of DI (P < 0.0001). There were no significant differences between DI negative and DI positive lesions in tumor location, macroscopic type, lymphatic and blood vessel permeation, lymph node metastasis, or prognosis. In 83 mucosal carcinomas, including in situ carcinomas or carcinomas that invaded no deeper than the lamina muscularis mucosa, no lymph node metastasis was found, and the 5-year survival rate was 100% (unaffected by the presence of DI). Among these 83 lesions, DI was found in 11 (13.8%), of which 6 (7.2%) had DI extending to the submucosal layer.

CONCLUSIONS

These results indicate that DI as a pathway of tumor spread to the deeper layer is of little significance in squamous cell carcinoma of the esophagus, and that mucosal carcinomas with DI that extends to the submucosa should not be classified as submucosal carcinoma.

Perforated patch-clamp recording in cardiac myocytes using cation-selective ionophore gramicidin

Whole cell currents were recorded in single myocytes dissociated from guinea pig ventricles by the patch-clamp technique. The addition of 0.1 mg/ml gramicidin D, a cation-selective ionophore, into the pipette solution induced a gradual spontaneous perforation of the patch membrane under a conventional cell-attached configuration. The access resistance, measured at approximately 12 min after formation of a gigaohm seal, was 9.2 +/- 1.5 M omega (n = 12). The perforated patch membrane exhibited ionic selectivity for various monovalent cations, with a relative order of Cs+ (1.11) > K+ (1.0) > Na+ (0.65) >> tris(hydroxymethyl)aminomethane+ (approximately 0) but was not permeable for Cl-. Under the gramicidin-perforated patch recording configuration, the cells showed the typical electrophysiological properties for ventricular cells reported previously. The intracellular Cl- concentration, estimated from the reversal potential of the catecholamine-induced Cl- current, was 36.3 +/- 2.9 mM (n = 17). We thus conclude that the gramicidin-perforated patch recording mode provides a useful tool for recording the ionic currents while maintaining the intracellular Cl- concentration.

Use of the time-signal intensity curve from dynamic magnetic resonance imaging to evaluate remnant pancreatic fibrosis after pancreaticojejunostomy in patients undergoing pancreaticoduodenectomy

BACKGROUND

This study assessed the value of the time-signal intensity curve (TIC) obtained from dynamic magnetic resonance imaging (MRI) in the evaluation of remnant pancreatic fibrosis after pancreaticojejunostomy in patients undergoing pancreaticoduodenectomy.

METHODS

Two modes of pancreaticojejunostomy-duct-to-mucosa anastomosis (DMA; 24 patients) and pancreatojejunoserosal anastomosis (PJSA; 22 patients)-were used in 46 consecutive patients undergoing pancreaticoduodenectomy. All patients underwent dynamic contrast-enhanced MRI of the pancreas before pancreaticoduodenectomy. Retrospective review of the pancreatic magnetic resonance images and histological examination of the pancreas were performed, and the patterns of TICs from dynamic MRI were compared with the degree of pancreatic fibrosis. Dynamic MRI of the residual pancreas was carried out for 1-3 years after pancreaticoduodenectomy in 26 patients (14 DMA, 12 PJSA) who had a histologically verified normal pancreas with no fibrosis at the time of pancreaticoduodenectomy.

RESULTS

Evaluation of preoperative dynamic magnetic resonance images showed that a pancreatic TIC with a rapid rise to a peak followed by a rapid decline (type I) was characteristic of a normal pancreas without fibrosis. Pancreatic TICs with a slow rise to a peak followed by a slow decline or a plateau (types II and III) indicated a fibrotic pancreas. Postoperative pancreatic MRI demonstrated that six of 12 patients with a PJSA had a type II TIC, whereas 12 of 14 patients with a DMA had a type I curve (P = 0.046).

CONCLUSION

The TIC obtained from dynamic MRI is a reliable indicator of fibrosis in the remnant pancreas after pancreaticoduodenectomy. Use of a DMA was associated with a lower risk of pancreatic fibrosis 1-3 years after surgery than a PJSA.

Impact of inflammation-based prognostic score on survival after curative thoracoscopic esophagectomy for esophageal cancer

BACKGROUND

Despite recent improvements in early detection, progress in surgical techniques, and development of chemoradiation therapies, prognosis of esophageal cancer remains poor. The aim of the present study was to assess whether Glasgow Prognostic Score (GPS), an inflammation-based prognostic score, has prognostic value independent of conventional clinicopathological criteria in patients undergoing curative resection for esophageal cancer, even in elderly patients.

METHODS

We retrospectively reviewed the database of 141 consecutive patients with histologically verified esophageal squamous cell carcinoma who underwent potentially curative surgery in our institute, between January 2006 and December 2014. GPS and neutrophil lymphocyte ratio (NLR) were calculated.

RESULTS

On multivariate analysis, TNM stage (p < 0.0001) and GPS (p = 0.041) were independently associated with worse prognosis in overall patients with esophageal cancer. Multivariate analysis evaluated the prognostic factors in two different patient groups: patients younger than 70 years (non-elderly) and those aged 70 years or more (elderly). Multivariate analysis demonstrated that TNM stage (p = 0.0003) was an only independent risk factor for a worse prognosis among non-elderly group. Meanwhile, multivariate analysis demonstrated that TNM stage (p = 0.001) and GPS (p = 0.043) were the independent risk factor for a worse prognosis among elderly group.

CONCLUSION

The present study demonstrated that GPS is associated with prognosis and can be considered as an independent prognostic marker in patients who underwent esophagectomy. Moreover, the GPS has the advantage of being simple to measure, routinely available and well standardized. But the present study failed to confirm the NLR as a significant predictor of survival following resection for esophageal cancer.

Switching of mouse spermatogonial proliferation from the c-kit receptor-independent type to the receptor-dependent type during differentiation

Testicular cells composed mostly of germ cells and immature Sertoli cells from neonatal mice 2 and 5 days old were cultured to investigate germ-cell proliferation mediated by the c-kit receptor. The addition of antibody to block the interaction of the c-kit receptor with its ligand inhibited the proliferation of cultured spermatogonia from 5-day-old mice in a dose-dependent manner, but not from that of 2-day-old mice. The addition of anti-c-kit ACK2 monoclonal antibody also inhibited the proliferation of spermatogonia from 5-day-old mutant Sld/Sld mice but not of 5-day-old mutant Wv/Wv mice. The results indicate that c-kit-positive type A spermatogonia in the testes of 5-day-old mice require steel factor (kit ligand) for their proliferation, whereas self-renewal and differentiation of c-kit-negative primitive type A spermatogonia in the testes of 2-day-old mice do not.

Insulin-like growth factor-I and transforming growth factor-alpha stimulate differentiation of type A spermatogonia in organ culture of adult mouse cryptorchid testes

This study assessed the effect of growth factors on testicular germ cell differentiation in vitro. Testicular fragments of experimentally prepared cryptorchid testes of adult mice were cultured for 9 days in serum-free media containing various concentrations of IGF-I, TGF-alpha, FGF, and PDGF. Their histology was then examined under a light microscope. Each type of germ cell and mitotic cell in the seminiferous tubules was counted per 1000 Sertoli cells. IGF-I at a concentration of 10 ng/ml induced maximal differentiation of type A spermatogonia. TGF-alpha at concentrations ranging from 1 to 10 ng/ml also stimulated differentiation, whereas FGF and PDGF did not show any stimulation of spermatogonial differentiation in this experimental system.