Keratinocytes: innate immune cells in atopic dermatitis

The skin is a unique immune organ that constitutes a complex network of physical, chemical and microbiological barriers against external insults. Keratinocytes are the most abundant cell type in the epidermis. These cells form the physical skin barrier and represent the first line of the host defense system by sensing pathogens via innate immune receptors, initiating anti-microbial responses and producing various cytokines, chemokines and anti-microbial peptides, which are important events in immunity. A damaged epidermal barrier in atopic dermatitis allows the penetration of potential allergens and pathogens to activate keratinocytes. Among the dysregulation of immune responses in atopic dermatitis, activated keratinocytes play a role in several biological processes that contribute to the pathogenesis of atopic dermatitis. In this review, we summarize the current understanding of the innate immune functions of keratinocytes in the pathogenesis of atopic dermatitis, with a special emphasis on skin-derived anti-microbial peptides and atopic dermatitis-related cytokines and chemokines in keratinocytes. An improved understanding of the innate immunity mediated by keratinocytes can provide helpful insight into the pathophysiological processes of atopic dermatitis and support new therapeutic efforts.

Oral administration of milk-derived phospholipids inhibits penetration of cutaneous nerve fibres into epidermis in a mouse model of acute dry skin

The density of intraepidermal nerve fibres has been shown to be higher in itchy dry skin than in healthy skin, suggesting that epidermal hyperinnervation is at least partly involved in peripheral itch sensitization. We investigated whether oral administration of milk-derived phospholipids (MPLs) would inhibit epidermal hyperinnervation in a mouse model of dry skin. We found that the number of intraepidermal nerve fibres was significantly lower in the MPL group than in the control group. Expression of nerve growth factor (NGF) levels in the epidermis was significantly decreased by oral administration of MPLs, whereas expression of semaphorin (Sema)3A, a nerve repulsion factor, was increased in the MPL group. These results suggest that dietary MPLs attenuate the penetration of nerve fibres into the epidermis by reducing epidermal NGF levels and increasing Sema3A level. Thus, dietary MPLs may have beneficial effects in the prevention and/or alleviation of dry skin-induced itch by reducing intraepidermal nerve fibre density.

Acute cholecystitis due to strangulation of a floating gallbladder by the lesser omentum

We report a unique case of acute cholecystitis due to strangulation of a floating gallbladder by the lesser omentum, which could be detected by abdominal ultrasonography. We believe this case to be the first case of reported literatures in English.

Intraoperative blood lactate level as an early predictor of initial graft function in human living donor liver transplantation

This study was performed to investigate whether intraoperative changes in blood lactate levels after hepatic allograft reperfusion reflect initial graft function in living donor liver transplantation (LDLT).

PATIENTS AND METHODS

From 1994 to 2003, 15 of LDLT cases were divided into two groups based on the intraoperative blood lactate levels. Group A consisted of seven recipients whose new liver grafts started to consume lactate immediately after portal perfusion. Group B consisted of the remaining eight recipients whose intraoperative blood lactate values showed no change or an elevation for 2 hours after graft revascularization.

RESULTS

All Group A patients survived, whereas three out of eight patients in Group B died of infection and portal vein thrombosis within 3 months after LDLT. There was no significant difference in preoperative donor and recipient laboratory data. The recipient age and body size in Group B were significantly higher than those in Group A, indicating that Group B consisted of small-for-size liver transplant cases. Serum total bilirubin concentrations in Group B were significantly higher than Group A from postoperative day 5 to 23, whereas postoperative liver enzyme levels and prothrombin time were similar between the two groups.

CONCLUSION

The change in intraoperative blood lactate after hepatic allograft reperfusion served as an accurate predictor of initial graft function which was associated with graft size in human LDLT.

Efficacy of cutting balloon for anastomotic stricture of the hepatic vein

Anastomotic stricture of the hepatic vein is an annoying complication, especially in living donor liver transplantation. Balloon dilation has been utilized but is sometimes associated with recurrences. Recently, a cutting balloon was invented for treatment of arteriosclerosis. Herein we report the results of application of this device for treatment of anastomotic strictures of the hepatic vein in two living donor liver transplant recipients who underwent percutaneous dilation of the hepatic vein with a cutting balloon (8 x 10 mm, Atherotome, Boston Scientific). Case 1, a 26-year-old woman transplanted for subacute fulminant hepatitis, had been treated for an anastomotic stricture by balloon dilation on 15 occasions over a 2- to 3-month interval. Case 2, a 13-year-old boy transplanted for cryptogenic liver cirrhosis, had been treated for an anastomotic stricture by balloon dilation biannually. The cutting balloon was applied safely without severe complications. The first case showed a recurrent anastomotic stricture at 6 months after dilation. Follow-up at 6 months in the second case revealed a mild recurrence of the stricture. Anastomotic stricture of the hepatic vein jeopardizes the graft and the recipient. The reported treatments involve venoplastic surgery and expandable metallic stents. Application of a cutting balloon seemed to be a safe, convenient modality. However, its effect was not indefinite, so a cutting balloon of greater diameter or application of an expandable metallic stent may be considered for patients with multiple recurrences of their anastomotic stricture.

Hepatic clearance improves after angioplasty of the hepatic vein

Anastomotic stricture sometimes causes hepatic congestion leading to decreased hepatic clearance of drugs. We herein describe a correlation between trough levels of tacrolimus and an anastomotic stricture of the hepatic vein. A 13-year-old boy underwent living donor liver transplant with a left lobe graft from his mother. Outflow blockage due to an anastomotic stricture of the hepatic vein developed 3 months after transplant. His anastomotic site had been repeatedly treated with percutaneous transvenous angioplasty (PTA) by balloon dilation. About 1 year after transplant, his trough level of tacrolimus promptly decreased after balloon dilation (from 15.7 to 5.6 ng/dL). Liver function tests showed abnormalities, which were diagnosed as acute cellular rejection, and he was treated with pulse steroid therapy. The calculated half-life of tacrolimus (T1/2) showed marked improvement after PTA (from 35 to 22 hours). A 45-year-old woman underwent living donor transplantation due to alcoholic liver cirrhosis with a left lobe graft from her brother. An anastomotic stricture of the hepatic vein developed 4 months after transplant. She was treated with balloon dilation, which caused an abrupt decrease in the trough level of tacrolimus (12 to 4 ng/dL). Her alkaline phosphatase was elevated and she was diagnosed with rejection, which was treated with an increase of dosage of tacrolimus. In outflow block, the T1/2 of tacrolimus increases probably due to decreased hepatic clearance by stagnation or congestion of the liver. However, hepatic clearance of drugs quickly recovers after PTA. Close monitoring of immunosuppressive agents is fundamental at the time of angioplasty to avoid acute cellular rejection as developed in our two cases.

Hepatic vein anastomotic stricture after living donor liver transplantation

This report discusses the pathophysiology of and therapeutic methods to address hepatic vein anastomotic stricture after living donor liver transplantation (LDLT). From 1994 to 2002, our 15 LDLTs using the lateral segments or left lobes included four recipients who experienced 28 occurrences of this complication after the operation. The period between LDLT and the first stricture was 4.0 +/- 1.2 months. The age of the affected recipients (31.0 +/- 8.2 years) was significantly higher than that of the nonaffected patients (7.0 +/- 4.1 years, P < .05). Graft liver/standard liver volume ratio was 39.1% +/- 3.8% in the former and 77.9% +/- 12.7% in the latter cases (P < .05). Initial symptoms of stricture were ascites (42.9%), abdominal distention (42.9%), liver enzyme elevation (10.7%), and gastrointestinal bleeding (3.6%). In addition, 14 of 28 stricture cases (50%) showed increased blood trough levels of tacrolimus. Doppler ultrasonography was used for diagnosis, and balloon dilatations performed in all stricture patients, thereby hepatic significantly reducing venous blood pressure from 33.5 +/- 1.7 to 20.3 +/- 1.5 cmH2O. All patients finally resolved the strictures after several treatments. The stricture after LDLT was associated with small-for-size grafts, suggesting that liver regeneration may lead to anatomical changes and strictures. Since tacrolimus is metabolized by the liver, its blood trough level is one initial symptoms of stricture. Balloon dilatation was useful and safe as the treatment, while problems have been reported after stent insertion in the hepatic vein.

Improved survival and ammonia metabolism by intraperitoneal transplantation of microencapsulated hepatocytes in totally hepatectomized rats

BACKGROUND

We evaluated the effects of intraperitoneal transplantation of microencapsulated hepatocytes in a 3-stage total hepatectomy rat model.

METHODS

A new model of total hepatectomy was created as follows. First, the infrahepatic inferior vena cava was ligated just above the right renal vein. Seven days later, the portal vein was ligated and a portacaval shunt was established using a Teflon catheter over a venipuncture needle. Another 7 days later, total hepatectomy was completed by ligating and dividing the suprahepatic inferior vena cava, the hepatic artery, and the bile duct. Next, 4 x 10(7) hepatocytes (4% of the normal liver hepatocyte mass) isolated from male Wistar rats were microencapsulated within a collagen matrix enveloped by a 3-layer membrane of sodium alginate-poly-L-lysine-sodium alginate copolymer. Capsules containing hepatocytes (diameter, 500-800 microm) and empty capsules (control) were transplanted intraperitoneally 4 days before the total hepatectomy. Survival time and selected blood chemistry concentrations after the total hepatectomy were measured. The capsules were also examined histologically with hematoxylin and eosin staining and modified Gmelin's stain for bile pigments.

RESULTS

The survival time was greater in the rats given the microencapsulated hepatocytes than in the control rats (17.3 +/- 3 vs 3.7 +/- 0.1 hours; P <.01). The blood ammonia concentrations increased soon after total hepatectomy but remained significantly lower in the rats with microencapsulated hepatocytes (P <.05). The microcapsules contained numerous viable hepatocytes with abundant bile pigments and no lymphocytic infiltration.

CONCLUSIONS

Microencapsulated hepatocytes with an ultrathin polymer layer that protects them from inflammatory and lymphocytic reactions may facilitate their ability to function. In this study, 4 x 10(7) hepatocytes significantly prolonged the survival of rats that underwent hepatectomy and supported ammonia metabolism. Further development of this technique may permit its use in patients with hepatic failure.

A physical map with yeast artificial chromosome (YAC) clones covering 63% of the 12 rice chromosomes

A new YAC (yeast artificial chromosome) physical map of the 12 rice chromosomes was constructed utilizing the latest molecular linkage map. The 1439 DNA markers on the rice genetic map selected a total of 1892 YACs from a YAC library. A total of 675 distinct YACs were assigned to specific chromosomal locations. In all chromosomes, 297 YAC contigs and 142 YAC islands were formed. The total physical length of these contigs and islands was estimated to 270 Mb which corresponds to approximately 63% of the entire rice genome (430 Mb). Because the physical length of each YAC contig has been measured, we could then estimate the physical distance between genetic markers more precisely than previously. In the course of constructing the new physical map, the DNA markers mapped at 0.0-cM intervals were ordered accurately and the presence of potentially duplicated regions among the chromosomes was detected. The physical map combined with the genetic map will form the basis for elucidation of the rice genome structure, map-based cloning of agronomically important genes, and genome sequencing.

Evolutionary aspects of gobioid fishes based upon a phylogenetic analysis of mitochondrial cytochrome B genes

The Gobioidei is a large suborder in the order Perciformes and consists of more than 2000 species belonging to about 270 genera. The vast number of species and their morphological specialization adapted to diverse habits and habitats makes the classification of the gobioid fishes very difficult.A comprehensive estimation of the evolutionary scenario of all gobioid fishes using only morphological information is difficult for two major reasons: first, in addition to wide ecological diversification, there is a trend towards specialization and degeneration of morphological characters among these species; second, an appropriate outgroup of gobioid fishes has not been recognized. Based upon nucleotide sequence comparisons of gobioid mitochondrial cytochrome b genes, we established the phylogenetic relationships of their differentiation into many groups of morphological and ecological diversity. The phylogenetic trees obtained show that most species examined have diverged from each other almost simultaneously or during an extremely short period of time.

Hd1, a major photoperiod sensitivity quantitative trait locus in rice, is closely related to the Arabidopsis flowering time gene CONSTANS

A major quantitative trait locus (QTL) controlling response to photoperiod, Hd1, was identified by means of a map-based cloning strategy. High-resolution mapping using 1505 segregants enabled us to define a genomic region of approximately 12 kb as a candidate for Hd1. Further analysis revealed that the Hd1 QTL corresponds to a gene that is a homolog of CONSTANS in Arabidopsis. Sequencing analysis revealed a 43-bp deletion in the first exon of the photoperiod sensitivity 1 (se1) mutant HS66 and a 433-bp insertion in the intron in mutant HS110. Se1 is allelic to the Hd1 QTL, as determined by analysis of two se1 mutants, HS66 and HS110. Genetic complementation analysis proved the function of the candidate gene. The amount of Hd1 mRNA was not greatly affected by a change in length of the photoperiod. We suggest that Hd1 functions in the promotion of heading under short-day conditions and in inhibition under long-day conditions.

Hd1, a major photoperiod sensitivity quantitative trait locus in rice, is closely related to the Arabidopsis flowering time gene CONSTANS

A major quantitative trait locus (QTL) controlling response to photoperiod, Hd1, was identified by means of a map-based cloning strategy. High-resolution mapping using 1505 segregants enabled us to define a genomic region of approximately 12 kb as a candidate for Hd1. Further analysis revealed that the Hd1 QTL corresponds to a gene that is a homolog of CONSTANS in Arabidopsis. Sequencing analysis revealed a 43-bp deletion in the first exon of the photoperiod sensitivity 1 (se1) mutant HS66 and a 433-bp insertion in the intron in mutant HS110. Se1 is allelic to the Hd1 QTL, as determined by analysis of two se1 mutants, HS66 and HS110. Genetic complementation analysis proved the function of the candidate gene. The amount of Hd1 mRNA was not greatly affected by a change in length of the photoperiod. We suggest that Hd1 functions in the promotion of heading under short-day conditions and in inhibition under long-day conditions.

Hd1, a major photoperiod sensitivity quantitative trait locus in rice, is closely related to the Arabidopsis flowering time gene CONSTANS

A major quantitative trait locus (QTL) controlling response to photoperiod, Hd1, was identified by means of a map-based cloning strategy. High-resolution mapping using 1505 segregants enabled us to define a genomic region of approximately 12 kb as a candidate for Hd1. Further analysis revealed that the Hd1 QTL corresponds to a gene that is a homolog of CONSTANS in Arabidopsis. Sequencing analysis revealed a 43-bp deletion in the first exon of the photoperiod sensitivity 1 (se1) mutant HS66 and a 433-bp insertion in the intron in mutant HS110. Se1 is allelic to the Hd1 QTL, as determined by analysis of two se1 mutants, HS66 and HS110. Genetic complementation analysis proved the function of the candidate gene. The amount of Hd1 mRNA was not greatly affected by a change in length of the photoperiod. We suggest that Hd1 functions in the promotion of heading under short-day conditions and in inhibition under long-day conditions.

Laparoscopic cholecystectomy performed by a single surgeon using a visual field tracking camera: early experience

BACKGROUND

This report describes a visual field tracking camera for laparoscopic surgery that allows the visual field to be changed without moving the laparoscope. We also report on our early experience with this camera for single-surgeon laparoscopic cholecystectomy.

METHODS

The visual field tracking camera has a tracking mechanism (composed of a zoom lens and a charge-coupled device [CCD] slide mechanism) built into the camera head. The 80 degrees visual field observed with the laparoscope can be expanded using the zoom lens, and the field can be shifted by changing the size of the area being viewed by the CCD. This is accomplished by pushing a switch on the forceps or by verbal command. Cholecystectomy was carried out on 12 patients with gallstones using this camera. The operations were performed by either a single surgeon or two surgeons. Forceps held with a forceps holder were inserted through the right port to lift the fundus of the gallbladder. The single surgeon used the other two ports to resect the gallbladder by the two-handed technique.

RESULTS

In all cases, cholecystectomy was completed without any need to move the laparoscope at any point during the operation. Seven operations were performed by a single surgeon. Mainly for education purposes, five other operations were performed by a pair of surgeons. The mean time required for surgery was 76 +/- 17 min. This time did not differ from that of laparoscopic cholecystectomy performed during the same period on 22 patients by teams of three surgeons using conventional cameras.

CONCLUSIONS

Using the visual field tracking camera, laparoscopic cholecystectomy can be performed without any need to touch the laparoscope. This camera allowed laparoscopic cholecystectomy to be performed by a single surgeon.

Warm ischemia and reperfusion injury in diet-induced canine fatty livers

BACKGROUND

Fatty liver is associated with primary nonfunction after liver transplantation, contributing a shortage of suitable liver grafts. Because extensive investigation of mechanisms underlying such nonfunction has been limited largely to rodents, we made a new fatty liver model in dogs and studied primary nonfunction after warm ischemia.

METHODS

We developed a diet rich in fat but deficient in choline to induce fatty change in canine liver and investigated effects of 60 min of warm ischemia and reperfusion in dogs with such fatty livers.

RESULTS

Microscopically evident steatosis increased with duration of dietary manipulation (up to 12 weeks), as did hepatic total lipid and triglyceride levels. No dog with >30% of steatotic hepatocytes, >445 mg/g hepatic total lipid or >145 mg/g hepatic triglyceride survived after 60 min of warm ischemia. Arterial ketone body ratios decreased and blood endotoxin increased after reperfusion in nonsurvivors. The main histologic finding in livers of nonsurvivors was marked sinusoidal congestion.

CONCLUSIONS

Damage to hepatocytes and nonparenchymal cells after warm ischemia and reperfusion was thought to be closely related to sinusoidal microcirculatory disturbances in fatty livers. The canine fatty liver model reported here may be useful in studying the pathology of primary nonfunction and in establishing criteria for allowable degrees of fatty change in potential liver grafts.

A case of living-related partial liver transplantation using the right gastroepiploic artery for hepatic artery reconstruction

A 13-year-old boy with liver cirrhosis underwent living-related partial liver transplantation with a left lobe from his mother. A standard hepatic artery reconstruction using the recipient right hepatic artery was anticipated. Unfortunately, the recipient hepatic artery was found to be severely arteriosclerotic and was unsuitable for reconstruction. Instead, the right gastroepiploic artery, measuring 2.0 mm in diameter, was mobilized and was anastomosed to the left hepatic artery of the graft in an end-to-end fashion. Arterial blood flow was satisfactory. The patient's postoperative course was uneventful, and he was transferred to a floor bed on the 5th postoperative day.

Application of restriction fragment fingerprinting with a rice microsatellite sequence to assembling rice YAC clones

To refine the current physical map of rice, we have established a restriction fragment fingerprinting method for identifying overlap between pairs of rice yeast artificial chromosome (YAC) clones and defining the physical arrangement of YACs within contiguous fragments (contigs). In this method, Southern blots of rice YAC DNAs digested with a restriction endonuclease are probed with a rice microsatellite probe, (GGC)5. The probe produces a unique fingerprint profile characteristic of each YAC clone. The profile is then digitized, processed in a computer, and a statistic that represents the degree of overlap between two YACs is calculated. The statistics have been used to detect overlaps among YAC clones, thereby filling a gap between two neighbouring contigs and organizing overlapping rice YAC clones into contiguous fragments. We applied this method to rearranging YACs that had previously been assigned to rice chromosome 6 by anchoring with RFLP markers.

Laparoscopic ultrasonography and operative cholangiography prevent residual common bile duct stones in laparoscopic cholecystectomy

We retrospectively evaluated the role of intraoperative cholangiography (IOC) combined with laparoscopic intraoperative ultrasonography (LIOU) for detection of common bile duct (CBD) stones in patients undergoing laparoscopic cholecystectomy. We reviewed 184 patients with biliary stones. Preoperatively, all patients underwent ultrasonography (US); 183 of the patients were investigated by cholangiography (oral and intravenous cholangiography in 145 and endoscopic retrograde cholangiography in 44). LIOU was carried out in all patients and IOC was done in 183. LIOU visualized the bile duct in 94.6% of the patients and IOC was successful in 95.6%. CBD stones were detected in a total of 17 patients, 9 (52.9%) of whom were positive on preoperative investigations. The sensitivity for detecting CBD stones was 29.4% with US, 22.2% with oral and intravenous cholangiography, 50.0% with endoscopic retrograde cholangiography, 82.4% with LIOU, and 93.3% with IOC. The diameter of the stones visualized intraoperatively (4.4 +/- 1.2 mm) was smaller than that of the stones detected preoperatively (6.9 +/- 2.6 mm). The stones were removed during laparoscopy in 15 patients and after conversion to laparotomy in 2. None of the patients had residual CBD stones after follow-up for 6 to 50 months. Intraoperative examination using both LIOU and IOC was useful for prevention of residual CBD stones.

Removal of cadmium from scallop hepatopancreas by microbial processes

A microbial process for removing cadmium from a homogenate of hepatopancreas, a waste of scallop processing, was devised to use this waste for value-added protein resources. Microorganisms were screened on the basis of the ability to remove cadmium from a medium with the initial concentration of 10 mg/l of cadmium. One soil isolate, identified as Xanthomonas sp. UR No. 2 by its taxonomical characteristics, removed 98% of the cadmium in the medium in 2 d. During cultivation of this strain in the homogenates of hepatopancreas digested by endopeptidases, 90% of cadmium was removed, while this strain had little effect on the simple non-digested homogenates. The mass balance of cadmium during homogenizations of the hepatopancreas tissues and cultivations in the protease-treated homogenate were examined. The content of crude proteins of culture supernatant treated by Xanthomonas sp. UR No. 2 was equivalent to those of various feedstuffs on the market.

Physical mapping of duplicated genomic regions of two chromosome ends in rice

Two genomic regions duplicated in distal ends of the short arms of chromosomes 11 and 12 in rice (Oryza sativa L.) were characterized by YAC ordering with 46 genetic markers. Physical maps covering most of the duplicated regions were generated. Thirty-five markers, including 21 rice cDNA clones, showed the duplicated loci arrayed strictly in the same order along the two specific genomic regions. Regardless of their different genetic distances, the two duplicated segments may have a similar and minimum physical size with an expected length of about 2.5 Mb. However, differences of RFLP frequency for the duplicated DNA copies and recombination frequency for a given homoeologous area between the two regions were observed, indicating that these changes in genome organization occurred after the duplication. Our results establish a good model system for resolving the relationships between gene duplication, expression of duplicated genes, and the frequency of meiotic recombination in small chromosomal regions.

Physical mapping of the rice genome with YAC clones

Construction of a rice physical map covered by YAC clones which have been arranged over half of the genome length is presented here. A total of 1285 RFLP and RAPD markers almost evenly distributed on the rice genetic map could select 2974 YAC clones and 2443 clones of them were located on their original positions. Rice YACs carrying 350 kb average insert fragments of 2443 clones could cover 222 megabase length of the rice genome, corresponding to 52% of the whole genome size (4.3 Mb). Chromosome landing with many YAC clones on the high-density genetic map loci efficiently integrated the genetic map with a physical map. This is the first step to generate a comprehensive genome map of rice. An integrated genome map should be an indispensable tool to figure out genome structure as well as to clone trait genes by map-based cloning.

Sinusoidal flow block after warm ischemia in rats with diet-induced fatty liver

Donor livers with massive fatty infiltration reportedly are susceptible to ischemia/reperfusion injury after transplantation, which contributes to risk of primary nonfunction. We investigated the effect of warm ischemia and reperfusion on sinusoidal microcirculation in rats with fatty livers from a choline-deficient diet. Rats were subjected to partial hepatic warm ischemia for 30, 60, or 90 min. In a second study, an anti-ICAM-1 monoclonal antibody was injected intraportally 2 min after a 60-min ischemic period. In both studies, injury was assessed by liver histology 6 hr after vascular clamp release and by animal survival. After 30 min of hepatic warm ischemia, almost all control and fatty-liver rats survived 7 days. After 60-min ischemia, however, survival was significantly less in rats with fatty livers than in controls with normal livers (10% vs 90%, P < 0.0001). Histologically, rats with fatty livers showed marked sinusoidal congestion, especially in the midzone of the acinus, while control rats showed no disturbance in microcirculation. In rats with fatty livers treated with intraportal injection of an anti-ICAM-1 antibody, sinusoidal microcirculation was well preserved and the 7-day survival rate after warm ischemia was improved (50% vs no antibody 10%; P = 0.0112). In fatty livers, midzonal sinusoidal flow block occurs after hepatic warm ischemia and reperfusion. Although intraportal injection of an anti-ICAM-1 monoclonal antibody corrected this microcirculatory failure, animal survival was not as good as for controls without fatty livers. These results suggest that both sinusoidal microcirculatory failure and ischemic hepatocellular damage contribute to warm ischemia/reperfusion injury in fatty livers.

Ordered YAC clone contigs assigned to rice chromosomes 3 and 11

Yeast artificial chromosome (YAC) clones were arranged on the positions of restriction fragment length polymorphism (RFLP) and sequence-tagged site (STS) markers already mapped on the high-resolution genetic maps of rice chromosomes 3 and 11. From a total of 416 and 242 YAC clones selected by colony/Southern hybridization and polymerase chain reaction (PCR) analysis, 238 and 135 YAC clones were located on chromosomes 3 and 11, respectively. For chromosomes 3 and 11, 24 YAC contigs and islands with total coverage of about 46% and 12 contigs and islands with coverage of about 40%, respectively, were assigned. Although many DNA fragments of multiple copy marker sequences could not be mapped to their original locations on the genetic map by Southern hybridization because of a lack of RFLP, the physical mapping of YAC clones could often assign specific locations of such multiple copy sequences on the genome. The information provided here on contig formation and similar sequence distribution revealed by ordering YAC clones will help to unravel the genome organization of rice as well as being useful in isolation of genes by map-based cloning.

Yeast artificial chromosome clones of rice chromosome 2 ordered using DNA markers

Yeast artificial chromosome (YAC) clones were ordered for the physical mapping of rice chromosome 2, the last of the 12 rice chromosomes to be assigned YACs by the Rice Genome Research Program. A total of 128 restriction fragment length polymorphism markers and 4 sequence-tagged site (STS) markers located on our high-density genetic map were used for YAC clone landing. By colony/Southern hybridization and polymerase chain reaction screening, a total of 239 individual YACs were selected from our YAC library of 6934 clones covering six genome equivalents. The YACs located on the corresponding marker positions in the linkage map formed 43 contigs and islands and were estimated to encompass about 50% of the length of rice chromosome 2.

Physical mapping of rice chromosomes 4 and 7 using YAC clones

Physical maps of rice chromosomes 4 and 7 were constructed by landing yeast artificial chromosomes (YACs) along our high-density molecular linkage map. Using 114 DNA markers, 258 individual YACs were located on chromosome 4. Sixty-two out of 258 YACs carried two or more DNA marker positions and formed 16 contigs which covered a total length of 17.1 cM. The other YACs were arranged to 23 positions. On chromosome 7, 203 individual YACs were landed on 109 DNA markers. Sixty-four out of 203 YACs formed 15 contigs which covered a total length of 21.8 cM and 139 YACs were localized to 26 positions. Chromosomes 4 and 7 were covered with minimum tiling paths of 45 and 48 YACs, respectively. Taking the average size of YAC insert DNA to be 350 kb and the entire genome size to be 430 Mb, about 16-18 Mb of each chromosome or an estimated 50% of their total lengths have been covered with YACs. Physical maps of these 2 chromosomes should be of great help in identifying useful trait genes and unraveling genetic and biological characteristics in rice.

Assignment of YAC clones spanning rice chromosomes 10 and 12

Yeast artificial chromosome (YAC) clones were assigned on rice (Oryza saliva L. cv. Nipponbare) chromosomes 10 and 12 using DNA markers from our high-density linkage map. Out of 1,383 markers localized in this genetic map, 68 and 74 markers were located on chromosomes 10 and 12, respectively. Screening of the YAC genomic library was conducted by colony hybridization and Southern hybridization using restriction fragment length polymorphism (RFLP) markers or by polymerase chain reaction (PCR) using sequence-tagged site (STS) markers. We have completed the screening of 68 markers on chromosomes 10 and 74 markers on chromosome 12. A total of 134 and 103 YACs were assigned to chromosomes 10 and 12, respectively, with an estimated coverage of more than 60% for chromosome 10 and about 47% for chromosome 12. As rice is considered a model plant for genome analysis, the ordered YAC clones on chromosomes 10 and 12 as well as other chromosomes will certainly be helpful for isolation of agronomically and biologically important genes and for understanding the genome structure of these chromosomes.

Physical mapping of rice chromosomes 8 and 9 with YAC clones

First efforts for physical mapping of rice chromosomes 8 and 9 were carried out by ordering YAC clones of a rice genomic DNA library covering six genome equivalents with mapped DNA markers. A total of 79 and 74 markers from chromosomes 8 and 9, respectively, were analyzed by YAC colony and Southern hybridization using RFLP markers of cDNA and genomic clones, and by polymerase chain reaction (PCR) screening using PCR-derived and sequence-tagged site (STS) markers. As a result, 252 YAC clones were confirmed to contain the mapped DNA fragments on both chromosomes. A contig map was constructed by ordering these YAC clones and about 53% and 43% genome coverage was obtained for chromosomes 8 and 9, respectively, assuming a YAC clone size of 350 kb and overlap between neighboring YACs of 50%. A continuous array of YAC clones with minimum overlap gave a total size of 18.9 Mb for chromosome 8 and 15.6 Mb for chromosome 9, which are close to previous estimates. These contig maps may provide valuable information that can be useful in understanding chromosome structure and isolating specific genes by map-based cloning.

Construction of YAC contigs on rice chromosome 5

A physical map of rice chromosome 5 was constructed with yeast artificial chromosome (YAC) clones along a high-resolution molecular linkage map carrying 118 DNA markers distributed over 123.7 cM of genomic DNA. YAC clones have been identified by colony and Southern hybridization for 105 restriction fragment length polymorphism (RFLP) markers and by polymerase chain reaction (PCR) screening for 8 sequence-tagged site (STS) markers and 5 randomly amplified polymorphic DNA (RAPD) markers. Of 458 YACs, 235 individual YACs with an average insert length of 350 kb were selected and ordered on chromosome 5 from the YAC library. Forty-eight contigs covering nearly 21 Mb were formed on the chromosome 5; the longest one was 6 cM and covered 1.5 Mb. The length covered with YAC clones corresponded to 62% of the total length, of chromosome 5. There were many multicopy sequences of expressed genes on chromosome 5. The distribution of many copies of these expressed gene sequences was determined by YAC Southern hybridization and is discussed. A physical map with these characteristics provides a powerful tool for elucidation of genome structure and extraction of useful genetic information in rice.

Physical mapping of rice chromosome 1 with yeast artificial chromosomes (YACs)

We have constructed a physical map of rice chromosome 1 using yeast artificial chromosomes (YACs). A YAC library of 350 kb average insert size, covering about 6 rice haploid genome equivalents, was screened using 182 DNA markers which we had previously located on chromosome 1, by colony hybridization and polymerase chain reaction (PCR) amplification. One hundred and sixty-two DNA markers identified at least one YAC each carrying one, two or more marker sequences, for a total of 476 clones. Of these identified YACs, 284 were located in their original positions on chromosome 1. These 284 YACs defined 69 YAC contigs or islands which are estimated to cover more than 60% of the total chromosome length. The use of mapped DNA markers in constructing a physical map facilitates the integration of genetic and physical maps, as well as fine ordering of the DNA markers, especially at sites where the markers are clustered tightly on the genetic map. Our high density molecular map has been proven, by chromosome landing with YACs using mapped DNA markers, to cover more than half of the entire length of chromosome 1. The remaining 192 YACs were selected by other copies of DNA markers that mapped on chromosome 1. This description of the YAC contigs formed on chromosome 1 constitutes the second report of rice physical mapping, following that for chromosome 6.

An ordered yeast artificial chromosome library covering over half of rice chromosome 6

Yeast artificial chromosome (YAC) clones carrying DNA marker sequences located on the rice genetic map of chromosome 6 were ordered for physical mapping. A total of 122 restriction fragment length polymorphism markers, 16 sequence-tagged site markers, and five random amplified polymorphic DNA markers located, on average, at 0.9-cM intervals, were used for YAC clone screening by colony/Southern hybridization and PCR screening, respectively. A total of 216 individual YACs were selected from our YAC library of 7000 clones covering six genome equivalents. Each DNA marker could select, on average, 4.8 YAC clones, with 11 clones being the maximum. The YACs localized to the corresponding linkage map positions form 43 contigs and encompass about 60% of rice chromosome 6. This is the first step in constructing a physical map covering the whole rice genome by chromosome landing with YAC clones. These YACs and data will be used soon to isolate phenotypical trait genes by map-based cloning.

Identification of a YAC clone carrying the Xa-1 allele, a bacterial blight resistance gene in rice

Map-based cloning methods have been applied for isolation of Xa-1, one of the bacterial blight resistance genes in rice.Xa-1 was previously mapped on chromosome 4 using molecular markers. For positional cloning of Xa-1, a high-resolution genetic map was made for theXa-1 region using an F2 population of 402 plants and additional molecular markers. Three restriction fragment length polymorphism (RFLP) markers, XNpb235, XNpb264 and C600 were found to be linked tightly to Xa-1, with no recombinants, and U08 750 was mapped 1.5 cM from Xa-1. The screening of a yeast artificial chromosome (YAC) library using theseXa-1-linked RFLP markers resulted in the identification of ten contiguous YAC clones. Among these, one YAC clone, designated Y5212, with an insert of 340 kb, hybridized with all three tightly linked markers. This YAC was confirmed to possess the Xa-1 allele by mapping the Xa-1 gene between both end clones of this YAC (Y5212R and Y5212L).

[A case of advanced gastric remnant carcinoma with Virchow's metastasis treated with neoadjuvant chemotherapy (low dose CDDP + 5-FU) followed by surgical resection]

The patient was a 64-year-old woman. At hospitalization she had gastric remnant carcinoma with Virchow's and paraaortic lymph node metastases, extensive local infiltration and obstructive jaundice. The lesions were considered nonresectable, and the patient was placed on neoadjuvant chemotherapy consisting of low-dose CDDP and 5-FU, which resulted in the disappearance of Virchow's and paraaortic lymph node metastases. She was considered to have a partial response (PR) and underwent lower esophageal resection, total remnant gastrectomy and splenectomy. Eight months after surgery, however, she died of disseminated carcinomatosis of bone marrow. Since this therapy was associated with only slightly adverse events (< or = Grade 1), this treatment modality appears to be safe. However, further studies will be necessary to identify what type of recurrence is responsive to this therapy and to evaluate its effect on patient survival.

A dioxygenase gene (Ids2) expressed under iron deficiency conditions in the roots of Hordeum vulgare

A lambda zapII cDNA library was constructed from mRNA isolated from Fe-deficient barley roots and screened with cDNA probes made from mRNA of Fe-deficient and Fe-sufficient (control) barley roots. Seven clones were selected. Among them a clone having the putative full-length mRNA of dioxygenase as judged by northern hybridization was selected and named Ids2 (iron deficiency-specific clone 2). Using a cDNA fragment as probe, two clones from the genomic library (lambda EMBL-III) were isolated and one was sequenced. The predicted amino acid sequence of Ids2 resembled that of 2-oxoglutarate-dependent dioxygenase. Ids2 is expressed in the Fe-deficient barley roots but is not in the leaves. The expression is repressed by the availability of Fe. Ids2 was also strongly expressed under Mn deficiency and weakly under Zn deficiency or excess NaCl (0.5%). The upstream 5'-flanking region of Ids2 has a root-specific cis element of the CaMV 35S promoter and a nodule-specific element of leghemoglobin, a metal regulatory element (MRE) and several Cu regulatory elements (UAS) of yeast metallothionein (CUP1).

Comparison of doubling times of serum carcinoembryonic antigen produced by various metastatic lesions in recurrent gastric and colorectal carcinomas

The authors measured the serial serum carcinoembryonic antigen (CEA) levels in patients with recurrent gastric or colorectal carcinoma. Among the 45 patients with recurrent gastric carcinomas, those with lung metastases showed the most prolonged CEA doubling time (CEA-DT), followed by those with liver and peritoneal metastases, respectively. Of the 31 patients with recurrent colorectal carcinomas, those with local recurrence showed the most prolonged CEA-DT, followed by those with lung, liver, and peritoneal metastases, respectively. A positive correlation was observed for gastric and colorectal carcinomas between CEA-DT in patients with metastatic lesions and outcome (R = 0.84 and 0.93, respectively). The results of the current study suggest that postoperative measurement of CEA-DT is useful in the determination of region of recurrence of carcinoma, which would permit early surgery and chemotherapy. Measurement of CEA-DT also may be helpful for the accurate determination of prognosis.

Expression of a gene specific for iron deficiency (Ids3) in the roots of Hordeum vulgare

To clone genes required for the synthesis of mugineic acid (MA) or for the transport of Fe(III)-MA, a lambda ZAPII cDNA library was constructed from poly(A)(+)-RNA isolated from Fe-deficient barley roots. The cDNA library was then used for differential screening of barley roots that had been grown in the presence and absence of iron. Seven clones that hybridized specifically to the probe for Fe deficiency were selected. One clone, presumably encoding a full-length mRNA, as deduced from Northern hybridization, was sequenced. The clone consisting of 1685 nucleotides encoded a putative protein of 169 amino acids and an M(r) of 18704. The gene was specifically expressed in the roots of iron-deficient barley. A search for homologies in a protein database (NBRF) revealed that the predicted protein product has a functional peptide domain that resembles that of 2-oxoglutarate-dependent dioxygenases.

Heterogeneity in early and advanced gastric carcinomas by flow cytometric DNA analysis

We investigated 230 systematically sampled fresh specimens from 12 early and 26 advanced gastric cancer patients by DNA flow cytometry for heterogeneity in DNA content. Fifty-eight percent of the 12 early gastric cancers were uniformly diploid and 42% were uniformly aneuploid. Fifty-four percent of advanced cancers were uniformly diploid in superficial layers and 42% were uniformly diploid in deep layers, whereas 46% were uniformly aneuploid in superficial layers, and 50% were uniformly aneuploid and 8% were heterogeneously aneuploid and diploid in deep layers. Both diploid and aneuploid samples were obtained from 15% for advanced cancers, but ploidy heterogeneity did not occur in early cancers. Heterogeneity for DNA index (more than one aneuploid DNA index) occurred in 46% of whole thickness of advanced cancers, in 19% of superficial layers of advanced cancers, and in 8% of early cancers. We concluded that DNA ploidy determination using superficial layer specimens may be reliable in early gastric cancer but must be interpreted with care in advanced cancer.

Evaluation of an oleic acid water-in-oil-in-water-type multiple emulsion as potential drug carrier via the enteral route

A water-in-oil-in-water (W/O/W) emulsion composed of oleic acid was used as a carrier of carboxyfluorescein (CF) via the enteral route, as a model for future drug transport. The absorption of CF in the small intestine of rats given the emulsion (W/O/W group) was compared with the absorption in a group administered CF alone (CF group), and a group administered a mixed micelle of oleic acid and a surface-active agent in CF solution (MM group). Higher amounts of CF were absorbed in the W/O/W and MM groups than in the CF group. At 120 min, the amount of CF remaining in the intestinal tract was smaller in the MM group than in the W/O/W group. In the early period, CF excretion into bile was higher in the MM group than in the W/O/W group, but from 120 to 360 min, CF excretion in the W/O/W group was higher than in the MM group (non-specific). The blood CF level was significantly higher at 240 and 360 min in the W/O/W group than in the other two groups. The highest concentration in lymph was found in the W/O/W group. The W/O/W emulsion was considered superior to the micelles because it maintained a higher blood level of CF over long periods and transferred it to the lymph. This suggests that the W/O/W emulsion is applicable as a drug carrier via the enteral route.

Laparoscopic gastropexy in a patient with chronic gastric volvulus

We report a case of chronic gastric volvulus that was successfully treated by laparoscopic gastropexy. This procedure is also considered applicable to operations for other gastrointestinal disorders requiring organ fixation.

Comparison of flow cytometric DNA content in primary gastric carcinoma and metastases

Nuclear DNA contents were comparatively determined by flow cytometry in primary and metastatic lesions from 112 cases with stomach cancer. Aneuploidy frequency and mean DNA index were higher in lymph node metastatic lesions than in primary lesions, both resected synchronously. In these lymph node metastatic lesions, DNA ploidy patterns did not change in 79% (89/112 cases), and did change in 21% (23/112 cases). Concordance of the DNA index between primary lesions and synchronous liver metastatic lesions was seen in 63% (5/8 cases), but the concordance rate was only 25% (4/16 cases) for primary lesions and metachronous liver metastatic lesions and 0% (0/8) for primary lesions and lung metastases. DNA ploidy changes in metastatic lesions were marked in distal metastatic lesions, or more marked in metachronous metastases than in synchronous ones. The results of the present study suggested the possibility of detecting changes in biological characteristics of metastatic lesions by flow cytometric DNA analysis.

Metastatic mode of gastric carcinoma by flow cytometric and clinicopathologic parameters

We used flow cytometric and conventional clinicopathologic parameters to analyse the metastatic mode of cancer in 113 stomach cancer patients. Liver metastasis was frequent in cases with intestinal-type cancer, cancer located in the distal stomach, positive venous invasion and aneuploid cancer. Lung and pleural metastasis (excluding nodular lung metastasis), however, were frequent in cases with serosal invasion and diploid cancer. Peritoneal metastasis was frequently seen with tumors located in the proximal or whole stomach, diffuse-type cancer and cancer with serosal invasion. All cases developing bone metastasis were positive for lymph node metastasis. DNA ploidy was partially related to the metastatic mode of stomach cancer, but this was not the sole parameter for predicting metastasis. However, prediction may be possible if based on both DNA ploidy and clinicopathologic parameters, suggesting the possibility of the prophylaxis of recurrence by appropriate postoperative adjuvant therapy.

Metastatic mode and DNA ploidy in gastric carcinoma

We studied the amounts of nuclear DNA in gastric cancer metastases histologically and cytochemically by flow cytometry, which was performed retrospectively on paraffin-embedded specimens from 95 patients. At surgery, all cases of aneuploid cancer were positive for lymph node metastases. Liver metastases were frequently seen in aneuploid cancer (63%, P < 0.01), while lung metastases were the most common in diploid cancer (50%, P < 0.05). The incidence of peritoneal metastasis was high in undifferentiated diploid cancer (72%, P < 0.01). Local lymph node recurrence after surgery was more common in aneuploid than in diploid cancer (P < 0.01). The incidence of bone and distant lymph node metastasis was found to be strongly dependent on tissue differentiation. The DNA ploidy pattern is thus considered to be closely linked to lymph node, liver, and lung metastases in gastric cancer.