Genome-wide association study of leaf photosynthesis using a high-throughput gas exchange system in rice

Enhancing leaf photosynthetic capacity is essential for improving the yield of rice (Oryza sativa L.). Although the exploitation of natural genetic resources is considered a promising approach to enhance photosynthetic capacity, genomic factors related to the genetic diversity of leaf photosynthetic capacity have yet to be fully elucidated due to the limitation of measurement efficiency. In this study, we aimed to identify novel genomic regions for the net CO2 assimilation rate (A) by combining genome-wide association study (GWAS) and the newly developed rapid closed gas exchange system MIC-100. Using three MIC-100 systems in the field at the vegetative stage, we measured A of 168 temperate japonica rice varieties with six replicates for three years. We found that the modern varieties exhibited higher A than the landraces, while there was no significant relationship between the release year and A among the modern varieties. Our GWAS scan revealed two major peaks located on chromosomes 4 and 8, which were repeatedly detected in the different experiments and in the generalized linear modelling approach. We suggest that high-throughput gas exchange measurements combined with GWAS is a reliable approach for understanding the genetic mechanisms underlying photosynthetic diversities in crop species.

MIC-100, a new system for high-throughput phenotyping of instantaneous leaf photosynthetic rate in the field

Photosynthesis occurs mainly in plant leaves and is a fundamental process in the global carbon cycle and in crop production. The exploitation of natural genetic variation in leaf photosynthetic capacity is a promising strategy to meet the increasing demand for crops. The present study reports the newly developed photosynthesis measurement system 'MIC-100,' with a higher throughput for measuring instantaneous photosynthetic rate in the field. MIC-100 is established based on the closed system and directly detects the CO2 absorption in the leaf chamber. The reproducibility, accuracy, and measurement throughput of MIC-100 were tested using soybean (Glycine max L. (Merr.)) and rice (Oryza sativa L.) grown under field conditions. In most cases, the coefficient of variance (CV) for repeated-measurements of the same leaf was less than 0.1. The photosynthetic rates measured with the MIC-100 model showed a significant correlation (R2 = 0.93-0.95) with rates measured by a widely used gas-exchange system. The measurement throughput of the MIC-100 is significantly greater than that of conventional open gas-exchange systems under field conditions. Although MIC-100 solely detects the instantaneous photosynthetic rate under a given environment, this study demonstrated that the MIC-100 enables the rough evaluation of leaf photosynthesis within the large-scale plant populations grown in the field.

Estimation of the congestion area volume in potential living donor remnant livers

BACKGROUND

Living donor liver transplantation is widely performed in adult patients. One of the problems in this setting is a small-for-size graft, which results in dysfunction and poor prognosis of a transplantation. A right liver graft was devised to overcome this problem; furthermore, inclusion of the middle hepatic vein (MHV) has been suggested to greatly improve recipient outcomes. However, extended right hepatectomy involves a surgical risk for the living donor in terms of congestion of the left paramedian sector. The volume of the venoocclusive region of a living donor liver possibly varies depending on the collateral patterns of veins draining the cranial part of segment 4 (S4).

PATIENTS AND METHODS

We were analyzed the normal livers of 50 patients who underwent triphasic contrast-enhanced multidetector row computed tomography during preoperative and postoperative examinations. The patient pathologies consisted of gastric cancer (n = 25), colon cancer (n = 1), or renal cancer (n = 24). We calculated the volume of the entire liver as well as those of the right graft and left remnant lobes for comparison with the drainage volume of each hepatic vein and its branches.

RESULTS

On the basis of the anatomic venous drainage of the cranial part of S4 (V4sup), we classified hepatic veins as group A (n = 31), the V4sup joined the left hepatic vein or the MHV distal to the vein draining S8 area (MV8), or group B (n = 19), V4sup joined the MHV proximal to MV8. The mean volume of the congested area was 6.9% in group A and 15.9% in group B. The venoocclusive areas in the remnant livers were estimated to be larger in group B (P < .001).

CONCLUSION

The collateral pattern of V4sup and MV8 as well as preoperative volumetric analysis are important for graft selection to decide the line of transection.

Real-time monitoring of liver damage during experimental ischaemia–reperfusion using a nitric oxide sensor

Background

Hepatic ischaemia–reperfusion (IR) injury may lead to liver damage during liver surgery, and intrahepatic nitric oxide (NO) levels may play a role in this context. The aim of this study was to demonstrate real-time changes in intrahepatic NO concentration during IR and to correlate potential hepatic NO production with liver damage using a selective NO sensor.

Methods

Wistar rats were exposed to 15 min of hepatic ischaemia followed by reperfusion, after which changes in intrahepatic NO levels were measured using an NO sensor. Additionally, rats were exposed to five successive periods of IR, each consisting of 15 min ischaemia followed by 5 or 15 min reperfusion, and hepatic damage was evaluated by blood tests and histological examination. Hepatic expression of Akt, phosphorylated Akt, endothelial nitric oxide synthase (eNOS) and phosphorylated eNOS was examined at different time points during and after IR by western blot and immunohistochemical analysis.

Results

During ischaemia, intrahepatic NO levels increased and reached a plateau at approximately 10 min. Repeated 15 min ischaemia–5 min reperfusion cycles reduced the maximum amount of NO produced during ischaemia gradually, and almost no NO production was observed during the fifth period of ischaemia. NO production following repeated ischaemia was proportional to the degree of hepatic viability. Phosphorylated eNOS was upregulated and correlated with the level of NO production during hepatic ischaemia.

Conclusion

Intrahepatic NO levels decrease during repeated IR in rats. Real-time monitoring of intrahepatic NO levels is useful for the prediction of IR-related liver injury during experimental liver surgery.

ON THE NYMPH AND PROSOPON OF THE TSUTSUGAMUSHI, LEPTOTROMBIDIUM AKAMUSHI, N. SP. (TROMBIDIUM AKAMUSHI BRUMPT), CARRIER OF THE TSUTSUGAMUSHI DISEASE

Nomenclature. As mentioned above, the prosopon and the nymph of the tsutsugamushi have many characteristics which distinguish it from the other trombidia. These are the pale color and small size of the body, delicacy of the skin, the conspicuous constriction between the cephalothoracic region and the abdomen, rudimentary eyes and tracheal openings, absence of tracheal capillaries, etc. The fact that the thumb or the appendage of the palpus does not start from the side of the fourth joint of the latter but from its end, is another charac teristic which does not occur in other trombidia. From the biological point of view two facts should be mentioned; i.e., the adult female does not deposit eggs in heaps, and in contrast to those of other species, the larvaæ hatch out all through the year and feed on mammals. From these characteristics running through all the stages of development, we believe that we are justified in claiming a new genus for the tsutsugamushi. We therefore propose to change the scientific name given to this mite by Brumpt in 1910, Trombidium akamushi, and to introduce instead, according to the suggestion of Drs. Goto and Watase, the name Leptotrombidium akamushi. Determinaton of Leptotrombidium akamushi, N. Sp. Prosopon and Nymph. 1. Pale color. 2. Delicacy of the skin. 3. Distinct constriction between the cephalothoracic region and the abdomen. 4. Rudimentary, sessile eyes. 5. Indistinctnes of tracheal openings. 6. Absence of tracheal capillaries. 7. Crista abruptly widened at the end. 8. One palpal claw. Larva. 1. One scutum. 2. Round pinacles. 3. Legs, six joints, not counting the coxa. 4. Haris on the coza: one each on Joints 1, 2, and 3. 5. Hairs on the scutum, including two tactile hairs, seven; one is in the median line. Specific Determination of Leptotrombidium akamushi, N. Sp. (Trombidium akamushi Brumpt, 1910). Prosopon. 1. Small size 2. Three pairs of sucking discs on the external genitalia. 3. Hairs of the body feathered, club-shaped at the end, and the colorless. 4. The appendage of the palpus tapes distinctly towards the end. Nymph. 1. The size of the body is smaller thant that of the prosopon. 2. Two pairs of sucking discs on the external genitalia. There are no other distinct differences in the external morphology between the proposon and the nymph. Larva. 1. The color of the body is orange-red, but becomes paler after sucking on mammals. 2. The hairs of the body average 110 to 120 in number. 3. One pair of double eyes. 4. The sucking tube is visible when feeding on mammals (Hayashi). 5. The salivary gland is relatively large (Kawamura and Komagata). 6. The number and arrangemetn of the hairs on the legs and mouth parts correspond to the description given by Hirst. 7. The larvæ are found all through the year. 8. The larva is the carrier of tsutsugamushi disease in man.

Disease-specific expression of VEGF and its receptors in AML cells: possible autocrine pathway of VEGF/type1 receptor of VEGF in t(15;17) AML and VEGF/type2 receptor of VEGF in t(8;21) AML

Various angiogenic factors, such as vascular endothelial growth factor (VEGF) and an associated molecule, placenta growth factor (PlGF), are thought to be important for normal and malignant hematopoiesis. This study examined mRNA expression of VEGF, PlGF and receptors for these molecules in AML cells and identified the disease-specific patterns of expression. AML M3 having t(15;17) abnormality showed highest expression of VEGF and VEGF receptor type 1 (VEGFR1), suggesting the autocrine pathway of VEGF-VEGFR1. Then, t(8;21) AML demonstrated augmented expression of VEGF and VEGF receptor type 2 (VEGFR2), suggesting VEGF-VEGFR2 autocrine pathway. Then, addition of VEGFR2 kinase inhibitor in Kasumi-1, a t(8;21) AML cell line, resulted in marked inhibition of cell growth, although growth inhibitory effect of R2 kinase inhibitor to HL-60 was marginal. In addition, cell cycle analysis study showed S-phase cell population reduction by R2 kinase inhibitor in Kasumi-1, but not in HL-60. This observation is thought to be the rationale for novel molecular target therapy directed to angiogenic molecules.

Reactivity of P-Glycoprotein Monoclonal Antibodies in Childhood Cancers

P-Glycoprotein (P-gp), the product of the mdr-1 gene, is implicated in the development of chemoresistance in a variety of, mostly adult, cancers. Its role in paediatric tumours, most of which are non-epithelial in origin, has yet to be fully elucidated. A study was undertaken to investigate reactivity of two P-gp monoclonal antibodies (MAbs), JBS-1 and MRK16, recognising cytoplasmic and surface epitopes, respectively, of the P-gp molecule, in a variety of newly diagnosed and relapsed childhood cancers. P-gp was not expressed in any of 36 tumours examined (neuroblastoma 13, nephroblastoma 12, rhabdomyosarcoma 6, lymphoma 3, teratoma 1, Ewings 1), 14 of whom had chemoresistant disease. Reactivity to both MAbs was also investigated in patients with acute leukaemia. Out of 10 diagnostic acute lymphoblastic leukaemia (ALL) samples, a positive reaction with JSB-1 was observed in 1 patient who failed to remit on standard induction therapy and in 3 of 6 patients in ALL relapse, only 1 of whom showed low grade positivity with MRK16. Both MAbs reacted positively in 1 patient with acute non-lymphocytic leukaemia (ANLL) at diagnosis who achieved remission with teniposide and cytosine arabinoside, but relapsed 7 months later and was again positive with both Mabs. JSB-1 also showed varying degrees of positivity in 4 out of 4 other patients in ANLL relapse. It would therefore appear that P-gp is unlikely to mediate chemoresistance in most solid tumours of childhood, but may well play a major role in the development of chemoresistance in acute leukaemia.

Serial MR imaging and 1H-MR spectroscopy in monozygotic twins with Tay-Sachs disease

Four-year-old monozygotic female twins with early onset Tay-Sachs disease are described. The sisters showed similar slowly progressive clinical symptoms and deterioration, however the younger sister also demonstrated intractable myoclonus in the right leg. The serial MR images and (1)H-MR spectroscopy of the brain were obtained in both twins. MR images showed high intensity on T (2)-weighted image in the bilateral white matter, however there were no signal changes in the basal ganglia and thalamus during any of the phases. The ratio of N-acetylaspartate (NAA)/creatine (Cr) was decreased in the both white matter lesions and the corpus striatum, and that of myoinositol (mI)/Cr was increased in the damaged white matter on MR spectroscopy. The elevation of the lactate peak was clearly demonstrated in the left basal ganglia of the younger sister; however it was not shown in cerebral lesions of the elder sister. Changes in metabolites on MR spectroscopy were closely linked to the respective clinical features of each twin. Follow-up examination by (1)H-MR spectroscopy is useful for the evaluation of neuronal changes in children with Tay-Sachs disease.

CT colonography to detect rectosigmoid involvement in patients with primary ovarian cancer

INTRODUCTION

We retrospectively evaluated the performance of preoperative computed tomographic (CT) colonography to detect tumor involvement of the rectosigmoid wall and predict the need for rectosigmoid resection in patients with primary ovarian cancer.

METHODS

Thirty-three patients with primary ovarian cancer who underwent preoperative CT colonographic examination were evaluated. The images of the examination were analyzed and compared with the subsequent surgical findings.

RESULTS

All abnormal findings (malignant infiltration of the rectosigmoid mucosa and extrinsic compression) revealed by conventional colonoscopy were correctly observed as extrinsic compression using CT colonography. The sensitivity, specificity, positive predictive value and negative predictive value of CT colonography for the prediction of rectosigmoid resection were 100%, 64.7%, 72.7%, and 100%, respectively. Though conventional colonoscopic examinations could not be completed in five patients because of the presence of extrinsic stenosis and occlusion at the sigmoid colon, CT colonography enabled the entire large bowel to be examined in these patients.

CONCLUSIONS

This preliminary study showed that the CT colonographic examination is feasible and safe. CT colonography seems to have several advantages over conventional colonoscopy for the detection of rectosigmoid involvement in patients with advanced ovarian cancer. For confirmation of the efficacy of CT colonography, further large prospective studies are needed.

Safety of ofloxacin (OFLX) and fosfomycin sodium (FOM) ear drops

OBJECTIVE

The objective of this study is to evaluate the safety of two ear drops, Ofloxacin (OFLX: Taribid Otic Solution, Daiichi Seiyaku) and Fosfomycin sodium (FOM: Fosmicin S, Meiji Seiyaku).

METHODS

Albino guinea pigs were used as experimental animals, and the ototoxicity was evaluated by means of threshold changes in the compound action potentials (CAP), when topically applied to the middle ear cavity of the guinea pig. The sound stimuli applied were; click sound, with tone bursts of 8 kHz, 4 kHz, and 2 kHz. In one group of animals, after one application of the ear drops in the right middle ear cavity, the change in CAP was compared with a contralateral saline control at 24h, one week, and four weeks. In other group of animals, the ear drops were applied into the middle ear cavity for seven consecutive days and the CAP was measured at 24h.

RESULTS

At 24h the CAP threshold for click, 8 and 4 kHz elevated significantly for both the saline and ear drop treatment, but the threshold returned to normal when measured at 7 days and 28 days. Seven consecutive days of ear drops administration resulted in no reduction in the CAP for either ear drops.

CONCLUSIONS

Based on the lack of changes in the CAP, these two ear drops studied did not show any significant ototoxicities.

The correlation between 1H-MR spectroscopy and clinical manifestation with tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is an autosomal dominant neurocutaneous disease. Cortical tubers are one of the standard intracranial hallmarks of TSC, they comprise subependymal hamartomas protruding into the ventricles, cortical and white matter hamartomas, and giant cell tumors. The clinical course of TSC varies from asymptomatic to severe, with epileptic seizures and psychomotor retardation. We discuss here the correlation between clinical manifestation and features on 1H-MR spectroscopy ( 1H-MRS) of the white matter involving cortical tubers in patients with TSC. Statistical analysis of the N-acetylaspartate (NAA), choline (Cho) and myoinositol (mI)/creatinine (Cr) ratios between tubers and normal controls showed decreased NAA/Cr and increased mI/Cr ratios (P<0.05) in tubers, but no significance difference in Cho/Cr. The significance of the clinical appearance is associated with a decreased ratio of NAA/Cr in tubers with TSC. An elevated ratio of mI/Cr in tuber does not parallel the severity of the clinical features of TSC. These findings suggest that 1H-MRS may be useful for the evaluation of the clinical severity and prognostic diagnosis of TSC.

Gene expression changes in a patient presenting nonleukaemic nasal granulocytic sarcoma to acute myelogenous leukaemia using 40 K cDNA microarray

This is a case report of granulocytic sarcoma occurring as a nasal lesion prior to the onset of acute myelogenous leukaemia (AML). To understand this case in more detail, we used 40,000 human cDNA microarray to identify the gene expression patterns of nonleukaemic stage bone marrow (BM), AML stage BM and AML stage peripheral blood cells and subsequently define the molecular basis of this disease progression. Of significance, we have tracked the expression profile of BM samples during the course of nonleukaemic to leukaemic progression, and identified a number of genes that may account for the growth potential of leukaemia cells and indicate poor prognosis of this case.

Inflammatory gene signature in ulcerative colitis with cDNA macroarray analysis

BACKGROUND

Most array analyses of ulcerative colitis have focused on identifying susceptibility genes for ulcerative colitis.

AIM

To clarify the changes in gene expression during inflammation in ulcerative colitis colon mucosa using cDNA macroarray.

METHODS

From 23 ulcerative colitis patients, 16 each of inflamed and non-inflamed specimens (total 32 samples for individual analysis) were obtained by colonoscopic biopsy. Eighteen of the 32 samples, used for pairwise analysis, consisted of nine sample pairs, each pair being from the same patient. We examined expression profiles of approximately 1300 genes with cDNA macroarray. Comparisons were made using two kinds of statistics, t-test and significance analysis of microarray in both analyses. The reproducibility of significant genes from the macroarray analysis was confirmed by real-time ploymerase chain reaction.

RESULTS

We detected five upregulated genes, categorized into proinflammatory genes (MRP14, GRO gamma and SAA1) and anti-inflammatory genes (TIMP1 and Elafin) in inflamed mucosa, and one upregulated gene (L-FABP) in non-inflamed mucosa.

CONCLUSIONS

As the cDNA macroarray analysis in this study exactly reflects the total profile of gene expression in the clinical setting of ulcerative colitis, the genes identified will be directly applicable to diagnostics or as novel therapeutic targets in active ulcerative colitis.

Present characteristics of symptomatic Entamoeba histolytica infection in the big cities of Japan

Medical records, for 2000 and 2001, of symptomatic amoebic patients who were treated at our hospitals in Tokyo, Yokohama and Osaka were studied retrospectively for the purpose of gathering epidemiological data on symptomatic Entamoeba histolytica infection. A total of 58 patients were treated. Fifty-five of them were male, and 96% of the male patients were Japanese. The mean age of patients was 44.9 years old, and 91% of patients contracted the disease in Japan. Fifty-six per cent of the male patients indicated that they were practising homosexuals, and 44% of the male patients denied these practices or left the question unanswered. The serum Treponema pallidum haemagglutination test was positive in 45% of the patients, and antibody to human immunodeficiency virus (HIV) was positive in 45%. Our study revealed that recent symptomatic E. histolytica infection almost exclusively afflicted middle-aged males in the big cities of Japan, that a majority of the patients were probably exposed to the causative organism during homosexual activity, and that an increasing number of patients will be co-infected with HIV.

Clinicopathologic evaluation after resection for ductal adenocarcinoma of the pancreas: a retrospective, single-institution experience

INTRODUCTION

Between April 1992 and December 2000, 167 patients with pancreatic carcinoma were evaluated and treated in our department. One hundred eight patients (64.7%) with pancreatic carcinoma underwent pancreatectomy. Of these patients, 94 had histologically proven ductal adenocarcinoma. The overall postoperative mortality rate was 3.2% (3 patients), and the morbidity rate was 35.1% (33 patients). The estimated 1-, 2-, 3-, and 5-year survival rates were 43.6%, 28.7%, 21.8%, and 12.9%, respectively. There were only six long-term survivors who survived >5 years after surgery. METHODOLOGY AND AIMS: Institutional experience with 94 consecutive patients with ductal adenocarcinoma who underwent pancreatectomy was reviewed to clarify the influence of 29 prognostic factors (5 host, 17 tumor, and 7 treatment factors). Special reference was made to determine whether these significant factors have an effect on long-term survival. Univariate and multivariate models were used to analyze the effect of prognostic factors on survival.

RESULTS

Univariate analysis indicated that blood loss, operative time, postoperative complications, histopathologic lymphatic and venous permeation, lymph node metastasis, conclusive stage, conclusive curability, resection margins, serosal invasion, size of tumor, retroperitoneal invasion, major arterial invasion, and mode of histologic infiltration were associated with significantly longer survival (p < 0.05). By Cox proportional hazards survival analysis, the most powerful predictors of outcome were venous permeation, lymph node metastasis, tumor diameter, and conclusive curability. The longest-term survivor had the most advanced stage (stage IV(b)) of disease and curability C. No long-term survivors had all of the good prognostic factors (according to multivariate analysis).

CONCLUSIONS

The prognosis after surgical resection of pancreatic carcinoma mostly depends on tumor factors. In this study, it was difficult to identify the determinants of long-term survival in patients with resectable tumors.

Expression of endothelial cell-associated molecules in AML cells

Recently, it has been clarified that interaction between hematopoietic cells and endothelial cells is important in normal hematopoiesis and leukemogenesis. In this study, we examined the relationship between AML cells and endothelial cells by analyzing the expression profile of angiogenic factors, angiopoietin-1 (Ang-1), Ang-2, Tie-2 (a receptor for angiopoietins) and vascular endothelial growth factor (VEGF). Our results demonstrated that CD7(+)AML expressed Ang-2 mRNA frequently and integrin-family adhesion molecules (CD11c and CD18) intensively, suggesting the close correlation with endothelial cells. On the other hand, in t(8;21) AML cells, expression of Ang-2 was infrequent and expression of integrin-family adhesion molecules (CD11b, CD11c and CD18) was weak, suggesting the sparse association with endothelial cells. As for CD7(+)AML cells, despite the frequent and intense expression of endothelial cell-associated molecules (such as Ang-2, CD11c and CD18), intensity of Tie-2 expression was quite low (P < 0.05). Ang-2 expressed in CD7(+)AML cells is not considered to act in an autocrine fashion, but to work on endothelial cells to "feed" leukemic cells. Although Ang-2 is recognized as a natural antagonist for Tie-2, our data presented here suggested the alternative role of Ang-2 in the relationship between endothelial cells and leukemia cells, at least in a subset of leukemia such as CD7(+)AML. These results were supported by the study using AML cell lines, KG-1 (CD7 negative) and its subline KG-1a (CD7 positive); KG-1 had mRNA expression profile of Ang-1(+)Ang-2(-)Tie-2(+), while KG-1a showed Ang-1(+)Ang-2(+)Tie-2(-). These difference in the expression profile of angiogenic factors between CD7(+)AML and t(8;21)AML may explain the characteristic morphological features of these leukemias (CD7(+)AML as blastic type and t(8;21)AML as differentiative type).

Lack of association between the hKCa3 gene and Japanese schizophrenia patients

Several researchers have suggested an association between large numbers of CAG repeats in the hKCa3 gene and schizophrenia. However, these reports remain inconclusive and require further investigation. We tried to replicate these results in 112 Japanese schizophrenia patients and 102 control subjects of highly matched age and sex by applying an allele dichotomization model. No association was found. The overall distributions of allele frequencies were not significantly different between schizophrenic patients and normal control subjects. In addition, we tested the association between the size of the CAG repeats and the scores on three dimensions (positive and negative symptoms, and disorganization), but no significant results were obtained. Our results do not support the involvement of the hKCa3 gene in schizophrenia, at least in the Japanese population.

Laparoscopic cholecystectomy and choledocholithotomy in patients with a previous gastrectomy

BACKGROUND

An increased incidence of cholelithiasis has been widely reported after truncal vagotomy and after gastric resection. In the early phase of patient selection, previous gastrectomy has been considered a relative contraindication to laparoscopic cholecystectomy (LC). In this study, we examined the management of LC in patients with previous gastrectomy.

STUDY DESIGN

LC was attempted on 1,260 consecutive patients. Of these patients, 29 had a previous gastrectomy. Surgical procedures that had been performed included Billroth I gastrectomies (15), Billroth II gastrectomies (10), and total gastrectomies (4). There were 23 cases of cholelithiasis, 4 chronic cholecystitis, 2 gallbladder polyps, I porcelain gallbladder, and I gallbladder cancer. Nine patients were diagnosed with stones in their common bile duct or common hepatic duct.

RESULTS

Preoperatively, seven of nine patients with common bile duct stones were subjected to endoscopic sphincterotomy, and the stones were removed successfully from five of these patients. In the remaining two patients, common bile duct stones were removed by laparoscopic choledocholithotomy by choledochotomy. The LC was completed in 26 patients (90%) who had undergone previous gastrectomy. In 449 patients who had previous abdominal surgery without a gastrectomy, only 4 patients (0.9%) required open surgery. In contrast, three patients (10%) with previous gastrectomy required open surgery. No major complications were recorded in this study series, and no residual or retained stones were seen during a followup period of 3 months.

CONCLUSIONS

Clear visualization of anatomic structures and landmarks, and scrupulous hemostasis are needed to perform a safe LC in these patients. We conclude that in our study patients, a previous gastrectomy is considered an indication for LC and laparoscopic choledochotomy.

Cellular localization of the signaling components of Arabidopsis His-to-Asp phosphorelay

In the higher plant, Arabidopsis thaliana, histidine-to-aspartate (His-to-Asp) phosphorelay signal transduction systems play crucial roles in propagation of environmental stimuli, including plant hormones. This plant has 11 sensor His-kinases, 5 histidine-containing phosphotransfer (HPt) factors (AHPs), and 20 response regulators (ARRs). To gain new insight into the functions of these phosphorelay components, their intracellular localization was examined with use of GFP-fusion proteins, constructed for certain representatives of HPt factors (AHP2) and type-A and type-B ARRs (ARR6/ARR7 and ARR10, respectively). The results showed that AHP2 is mainly located in the cytoplasmic space, while both the types of ARRs have an ability to enter preferentially into the nuclei, if not exclusively. Together with the results from an in vitro phosphorelay assay with AHP2 and ARRs, these results are discussed, in terms of a geneal framework of the Arabidopsis His-to-Asp phosphorelay network.

Laparoscopic splenectomy for a lymphangioma of the spleen: report of a case

We present the first case report of a successful laparoscopic complete excision of a splenic lymphangioma. The splenic tumor was preoperatively diagnosed to be a lymphangioma by the combined modalities of ultrasonography, computed tomography, magnetic resonance imaging, and angiography. A laparoscopic splenectomy was subsequently performed and the pathological examination of the mass confirmed the diagnosis of a lymphangioma. Based on the above findings, a laparoscopic splenectomy is recommended when a splenic tumor is suspected to be either benign or borderline.

Phenotype-genotype relationships in peroxisome biogenesis disorders of PEX1-defective complementation group 1 are defined by Pex1p-Pex6p interaction

The peroxisome biogenesis disorders (PBDs), including Zellweger syndrome (ZS), neonatal adrenoleucodystrophy (NALD) and infantile Refsum disease (IRD), are fatal autosomal recessive diseases caused by impaired peroxisome biogenesis, of which 12 genotypes have been reported. ZS patients manifest the severest clinical and biochemical abnormalities, whereas those with NALD and IRD show less severity and the mildest features respectively. We have reported previously that temperature-sensitive peroxisome assembly is responsible for the mildness of the clinical features of IRD. PEX1 is the causative gene for PBDs of complementation group E (CG-E, CG1 in the U.S.A. and Europe), the PBDs of highest incidence, encoding the peroxin Pex1p of the AAA ATPase family. It has been also reported that Pex1p and Pex6p interact with each other. In the present study we investigated phenotype-genotype relationships of CG1 PBDs. Pex1p from IRD such as Pex1p with the most frequently identified mutation at G843D was largely degraded in vivo at 37 degrees C, whereas a normal level of Pex1p was detectable at the permissive temperature. In contrast, PEX1 proteins derived from ZS patients, including proteins with a mutation at L664P or the deletion of residues 634-690, were stably present at both temperatures. Pex1p-G843D interacted with Pex6p at approx. 50% of the level of normal Pex1p, whereas Pex1p from ZS patients mostly showing non-temperature-sensitive peroxisome biogenesis hardly bound to Pex6p. Taking these results together, we consider it most likely that the stability of Pex1p reflects temperature-sensitive peroxisome assembly in IRD fibroblasts. Failure in Pex1p-Pex6p interaction gives rise to more severe abnormalities, such as those manifested by patients with ZS.

Temperature sensitivity in peroxisome assembly processes characterizes milder forms of peroxisome biogenesis disorders

Peroxisome biogenesis disorders (PBDs) contain various clinical phenotypes; Zellweger syndrome (ZS), neonatal adrenoleukodystrophy (NALD), and infantile Refsum disease (IRD), decreasing in the clinical severity in this order. We found that all IRD cell lines and some NALD lines belonging to several different complementation groups are temperature-sensitive in peroxisome assembly; that is, they lacked catalase-positive peroxisomes at 37 degrees C, but do gain the peroxisomes at 30 degrees C. We identified heterozygous mutations E55K/R119Stop in the PEX2 gene of an IRD patient of complementation group F. The E55K mutation was the direct cause of the temperature-sensitivity because similar phenotypes could be transferred to PEX2-defective CHO cells by transfecting the mutant gene. Thus, temperature-sensitive peroxisome assembly is representative of milder forms of PBDs.

Piggyback foldable intraocular lens implantation in patients with microphthalmos

PURPOSE

To evaluate the clinical results of phacoemulsification and implantation of 2 foldable acrylic intraocular lenses (IOLs) in microphthalmic eyes.

SETTING

University of Tokyo School of Medicine, Tokyo, Eguchi Eye Hospital, Hakodate, and Osaka Rosai Hospital, Osaka, Japan.

METHODS

This study comprised 5 eyes of 3 patients whose manifest spherical equivalent was +10.5 to +18.0 diopters (D) and axial length was 15.79 to 16.82 mm. After phacoemulsification, 2 foldable acrylic IOLs with a mean power of +43.0 D +/- 9.5 (SD) (range +32.0 to +55.0 D) were implanted in the capsular bag.

RESULTS

There were no significant intraoperative complications, and there was significant improvement in uncorrected and best corrected visual acuities after surgery. The spherical equivalent decreased significantly; however, the postoperative refraction was considerably more hyperopic than predicted in all eyes. Except for posterior synechias in 2 eyes and slight interlenticular opacification in 2 eyes, no major postoperative complications occurred during the mean follow-up of 14.8 months.

CONCLUSIONS

Implanting 2 piggyback IOLs was beneficial in eyes with an extremely short axial length. However, the current system of lens power calculation markedly underestimates the required lens power, resulting in a hyperopic refractive error after surgery. The benefits of in-the-bag placement of 2 foldable lenses are questionable.

Malignant lymphoma of the bone associated with systemic sarcoidosis

A 57-year-old woman was hospitalized with malignant lymphoma of the right talus. After treatment, complete remission was obtained. Gallium-67 scintigraphy to confirm the remission demonstrated increased uptake in the whole body skeletal muscle, especially in her thighs. Biopsy of right gastrocnemius muscle showed epithelioid granuloma. Serum angiotensin-converting enzyme activity (ACE) and lysozyme had increased to several times the normal range. We diagnosed her disease as bone-associated sarcoidosis-lymphoma syndrome. Human herpes virus 8 (HHV-8) genome was examined in the bone marrow specimen, and the relationship between sarcoidosis-lymphoma syndrome and HHV-8 was discussed.

Ruptured dissecting aneurysm in bilateral iliac arteries caused by Ehlers-Danlos syndrome type IV: report of a case

Ehlers-Danlos syndrome (EDS) is an inherited disorder of connective tissue characterized by hyperextensible skin, hypermobile joints, and abnormalities of the cardiovascular system. Ten types and several subtypes of EDS have so far been recognized based on genetic, clinical, and biochemical characteristics. The spectrum of the disorder varies from mild to life-threatening vascular complications. EDS type IV is a particularly dangerous form with a lethal spontaneous rupture of the major arteries and aneurysmal formation. We present herein a case of a ruptured dissecting aneurysm in the bilateral iliac arteries caused by EDS type IV. A previously healthy 33-year-old man without any physical features of this connective tissue disorder experienced a metachronous vascular rupture two times. Successful synthetic bypass grafting was performed with great difficulty. The diagnosis of EDS type IV was made afterwards based on an electrophoresis analysis of a skin biopsy specimen which revealed a lack of type III collagen. Surgical intervention in cases of arterial complications in EDS type IV patients have been reported to be both difficult and frequently unsuccessful. The early clinical recognition of this syndrome is therefore of great importance due to the hazards of such surgical therapies.

Clinical, biochemical and genetic aspects and neuronal migration in peroxisome biogenesis disorders

Peroxisome biogenesis disorders (PBDs) are severe autosomal recessive neurological diseases caused by a defect of peroxisomal assembly factors. Zellweger syndrome, the most severe phenotype, is characterized by hypotonia, psychomotor retardation and neuronal migration disorder. Neonatal adrenoleukodystrophy and infantile Refsum disease are milder phenotypes of this disease. Thirteen complementation groups have been established since the genetic heterogeneity of PBDs was elucidated in 1988. Eleven genes for PBDs have been identified either by a functional complementation cloning or by EST homology searches. In 1992, the first gene for PBDs, PEX2, was identified. It encodes peroxisomal integral membrane protein with a RING finger domain. PEX5 and PEX7 are the genes for peroxisomal targeting signal (PTS)-1 and -2 receptors, respectively. PEX3, PEX16 and PEX19 are considered to be required for the early stage of peroxisome biogenesis. PEX13 protein has an SH3 docking site that binds to the PTS-1 receptor. PEX1 and PEX6 encode ABC protein, and PEX10 and PEX12 also encode integral membrane protein, with RING finger. Temperature-sensitivity, whereby peroxisomal biogenesis and metabolic dysfunctions are restored at 30 degrees C in cells from mild phenotypes, is a useful event for predicting the clinical severity and for elucidation of peroxisome biogenesis. Investigations using knockout mice are expected to facilitate understanding of migration disorders.

The clinical course of childhood and adolescent adrenoleukodystrophy before and after Lorenzo's oil

The clinical course of Japanese patients with childhood and adolescent adrenoleukodystrophy (ALD) who were treated with Lorenzo's oil after the progression of early symptoms was investigated by Kaplan-Meier analyses. Many of the early symptoms, including visual, personality, hearing, mental and speech disturbances, had already appeared when the oil therapy was started. These early symptoms appeared significantly faster than bed-ridden state or dysphagia (P<0.01). Gait disturbance appeared faster than bed-ridden state and dysphagia (P<0.05), and tended to appear later than the early symptoms. These results would reflect the early natural course of childhood and adolescent ALD before treatment, and provide a basis for the evaluation of therapeutic trials for ALD.

Clinical and bacteriological profiles of patients with typhoid fever treated during 1975-1998 in the Tokyo Metropolitan Komagome Hospital

Patients with typhoid fever presenting to the Tokyo Metropolitan Komagome Hospital during the period 1975-1998 were retrospectively investigated. All cases were diagnosed by a positive culture for Salmonella typhi in either of their clinical specimens. Of the total number of 130 patients, 57% contracted the disease abroad; this population increased in later years as the total numbers of cases decreased. The period from disease onset to diagnosis averaged 14 days with 20% of the cases requiring over three weeks to establish a diagnosis. As for symptomatology relative bradycardia was seen in less than half of the cases, and rose spots or splenomegaly in less than one third. A positive blood culture was the most frequent test establishing the diagnosis followed by a positive stool culture. Intestinal bleeding was recognized in as many as 35 cases (27%) and even intestinal perforation occurred in two cases (1.5%). Chloramphenicol was most commonly employed during the early study period, however, during the late period it was replaced by fluoroquinolones. The clinical cure rate was 98% with regimens that include fluoroquinolones/quinolone; however it was 87% with the other antimicrobial regimens. Bacteriological relapse occurred in 25% of the non-fluoroquinolone group while only in 2.0% in the fluoroquinolone/quinolone group. Four strains of Salmonella typhi that were multi-resistant to chloramphenicol, ampicillin and cotrimoxazole were isolated in travelers from Asia. Early diagnosis by appropriate bacteriological examination regardless of classical symptomatology should be stressed and the use of fluoroquinolones is warranted in the treatment of typhoid fever.

[Two cases of typhoid fever with reduced susceptibility to fluoroquinolones]

Two separate febrile Indian patients who reside in Japan and had recently returned from their country were diagnosed as suffering from typhoid fever. Fluoroquinolone therapy was clinically ineffective and the addition of a third-generation cephalosporin was required in each case. Each strain of Salmonella Typhi was resistant to nalidixic acid in vitro and also showed higher minimal inhibitory concentration to other quinolones than usual susceptible strains. Similar cases of typhoid fever responding poorly to quinolone treatment have been observed in the Indian subcontinent, south-east Asia and central Asia since the early 1990s, and potential spread by travelers into Japan is of serious concern. Although quinolones still remain the drugs of choice for treatment of typhoid fever, physicians should be aware of the possibility and implications of clinical treatment failure.

Catalase-less peroxisomes. Implication in the milder forms of peroxisome biogenesis disorder

We established a Chinese hamster ovary cell line having a temperature-sensitive phenotype in peroxisome biogenesis. This mutant (65TS) was produced by transforming a PEX2-defective mutant, Z65, with a mutant PEX2 gene, PEX2(E55K), derived from a patient with infantile Refsum disease, a milder form of peroxisome biogenesis disorder. In 65TS, catalase was found in the cytosol at a nonpermissive temperature (39 degrees C), but upon the shift to a permissive temperature (33 degrees C), catalase gradually localized to the structures containing a 70-kDa peroxisomal membrane protein, PMP70. In contrast to catalase, other matrix proteins containing typical peroxisome targeting signals, acyl-CoA oxidase and peroxisomal 3-ketoacyl-CoA thiolase, were co-localized with PMP70 in most cells, even at 39 degrees C. We found that these structures are partially functional peroxisomes and named them "catalase-less peroxisomes." Catalase-less peroxisomes were also observed in human fibroblasts from patients with milder forms of peroxisome biogenesis disorder, including the one from which the mutant PEX2 gene was derived. We suggest that these structures are the causes of the milder phenotypes of the patients. Temperature-dependent restoration of the peroxisomes in 65TS occurred even in the presence of cycloheximide, a protein synthesis inhibitor. Thus, we conclude that in 65TS, catalase-less peroxisomes are the direct precursors of peroxisomes.

The yabG gene of Bacillus subtilis encodes a sporulation specific protease which is involved in the processing of several spore coat proteins

The synthesis and proteolysis of the spore coat proteins, SpoIVA and YrbA, of Bacillus subtilis were analyzed using antisera. Almost no intact full-length proteins of either type were extracted from wild-type spores, while yabG mutant spores contained intact SpoIVA and YrbA proteins. We purified recombinant YrbA and YabG proteins from Escherichia coli transformants and found that YrbA was cleaved to the smaller moiety in the presence of YabG in vitro. These observations indicate that YabG is a protease involved in the proteolysis and maturation of SpoIVA and YrbA proteins, conserved with the cortex and/or coat assembly by B. subtilis.

Compilation and characterization of histidine-containing phosphotransmitters implicated in His-to-Asp phosphorelay in plants: AHP signal transducers of Arabidopsis thaliana

Histidine (His)-to-Aspartate (Asp) phosphorelay signal transduction systems are generally made up of a "sensor histidine (His)-kinase", a "response regulator", and a "histidine-containing phosphotransmitter (HPt)". In the higher plant, Arabidopsis thaliana, results from recent intensive studies suggested that the His-to-Asp phosphorelay mechanism is at least partly responsible for propagation of environmental stimuli, such as phytohormones (e.g. ethylene and cytokinin). Here we compiled the members of the HPt family of phosphotransmitters in Arabidopsis thaliana (AHP-series, Arabidopsis HPt phosphotransmitters), based on both database and experimental analyses, in order to provide a comprehensive basis at the molecular level for understanding the function of the AHP phosphotransmitters that are implicated in the His-to-Asp phosphorelay of higher plants.

Temperature-sensitive mutation of PEX6 in peroxisome biogenesis disorders in complementation group C (CG-C): comparative study of PEX6 and PEX1

Peroxisome biogenesis disorders (PBD), including Zellweger syndrome, neonatal adrenoleukodystrophy, and infantile Refsum disease, are a group of genetically heterogeneous autosomal-recessive diseases caused by mutations in PEX genes that encode peroxins, proteins required for peroxisome biogenesis. Zellweger syndrome patients present the most severe phenotype, whereas neonatal adrenoleukodystrophy patients are intermediate and infantile Refsum disease patients have the mildest features. PEX6 is a causative gene for PBD of complementation group C (CG-C) and encodes the peroxin Pex6p, one of the ATPases associated with diverse cellular activities and a member of the same family of proteins as Pex1p, a causative protein for PBD of CG-E (CG1). Here, we identified the temperature sensitivity of peroxisomes in the fibroblasts of a patient with neonatal adrenoleukodystrophy in CG-C. Peroxisomes were morphologically and biochemically formed at 30 degrees C but not at 37 degrees C. This patient was homozygous for a missense mutation, T-->C at nucleotide 170 resulting in a change from leucine to proline at amino acid 57 (L57P) in Pex6p. CG-C cell mutants (ZP92) in the Chinese hamster ovary transfected with L57P in HsPEX6 revealed the same temperature-sensitive phenotype. However, PEX1-deficient Chinese hamster ovary cell mutants (ZP101) transfected with L111P in PEX1, the counterpart to L57P in PEX6, showed no temperature sensitivity. In addition, ZP92 transfected with G708D in PEX6, the counterpart to the temperature-sensitive mutation G843D in PEX1, revealed no temperature-sensitive phenotype. These results indicate that L57P in Pex6p is a temperature-sensitive mutation causing the milder phenotype in a patient with PBD in CG-C. They also indicate that the amino acid residues responsible for temperature sensitivity do not seem to be conserved between Pex6p and Pex1p.

Identification of PEX3 as the gene mutated in a Zellweger syndrome patient lacking peroxisomal remnant structures

Peroxisome biogenesis disorders, of which 13 complementation groups have been identified, are subdivided with regard to two major dysfunctions: peroxisomal matrix protein import and peroxisomal membrane synthesis. Detectable remnant membrane structures are evident only in the former. Molecular defects have been defined in 10 PEX genes, including eight related to protein import and two to membrane synthesis. We now have evidence that the human complete cDNA encoding Pex3p, a peroxisomal membrane protein (PMP) factor for the proper localization of PMPs, rescues the import of both PMP and the matrix protein in fibroblasts from a Zellweger syndrome patient of complementation group G. This patient was homozygous for a 1 base insertion in the codon for V182, which resulted in a change of codon (182-183) and introduced a termination codon (184), which inactivated PMP and matrix protein import by Pex3p. A PEX3-defective CHO mutant clone, ZPG208, was of the same complementation group as group G.

Genomic structure and identification of 11 novel mutations of the PEX6 (peroxisome assembly factor-2) gene in patients with peroxisome biogenesis disorders

The PEX6 (peroxisome assembly factor-2, PAF-2) gene encodes a member of the AAA protein (ATPases associated with diverse cellular activities) family and restores peroxisome assembly in fibroblasts from peroxisome biogenesis disorder patients belonging to complementation group C (group 4 in the United States). We have now clarified the genomic DNA structure of human PEX6 and identified mutations in patients from various ethnic groups. The human PEX6 gene consists of 17 exons and 16 introns, spanning about 14kb. The largest exon, exon 1, has at least 952 bp nucleotides. Eleven novel mutations (18 alleles) were identified by direct sequencing of the PEX6 cDNA from 10 patients. All these mutations have been confirmed in the corresponding genomic DNA. There was no common mutation, but an exon skip was identified in two unrelated Japanese patients. Most of the mutations led to premature termination or large deletions of the PEX6 protein and resulted in the most severe peroxisome biogenesis disorder phenotype of Zellweger syndrome. A patient with an atypical Zellweger syndrome had a missense mutation that was shown to disrupt the cell's ability to form peroxisomes. This mutation analysis will aid in understanding the functions of the PEX6 protein in peroxisomal biogenesis. Hum Mutat 13:487-496, 1999.

Genes encoding pseudo-response regulators: insight into His-to-Asp phosphorelay and circadian rhythm in Arabidopsis thaliana

In the higher plant, Arabidopsis thaliana, results from recent intensive studies suggested that His-to-Asp phosphorelay mechanisms are involved presumably in propagation of environmental stimuli, such as phytohormones (e.g. ethylene and cytokinin). Here we identified and characterized a set of novel Arabidopsis genes whose products considerably resemble the authentic response regulators (ARR-series) of Arabidopsis in the sense that they have a phospho-accepting receiver-like domain. However, they should be discriminated from the classical ones in the strict sense that they lack the invariant phospho-accepting aspartate site. They were thus named APRRs (Arabidopsis pseudo-response regulators). Two such representatives, APRR1 and APRR2, were characterized extensively through cloning of the corresponding cDNAs, in terms of their structural designs, biochemical properties, subcellular localization in plant cells, and expression profiles at the transcriptional level. The result of in vitro phosphorylation experiment with the Arabidopsis AHP phosphotransmitter suggested that the pseudo-receivers have no ability to undergo phosphorylation. The result of transient expression assay with onion epidermal cells showed that the GFP-APRR1 fusion protein has an ability to enter into the nuclei. The C-terminal domain of APRR1, termed CONSTANS-motif, appears to be responsible for the nuclear-localization. The most intriguing result was that the accumulation of APRR1 transcript is subjected to a circadian rhythm. The APRR1 protein is identical to the one that was recently suggested to interact with the ABI3 (ABISCISIC ACID INSENSITIVE3) protein. These are discussed with special reference to the His-to-Asp phosphorelay signal transduction and circadian rhythm in Arabidopsis thaliana.

Microsatellite instability in patients with multiple primary cancers of the gastrointestinal tract

BACKGROUND

Little is known about the genetic alterations in multiple primary cancers of the gastrointestinal tract. Microsatellite instability (MSI) is frequently observed in hereditary non-polyposis colorectal cancer (HNPCC), and multiple primary cancers is a feature of this syndrome.

AIMS

To identify MSI incidence, target gene mutation, and mismatch repair (MMR) protein status in patients with multiple primary cancers of the gastrointestinal tract.

SUBJECTS

Fifty seven cancers from 22 Japanese patients with multiple primary cancers of the stomach, duodenum, colon, and rectum.

METHODS

MSI was examined at 5-7 microsatellite loci. Mutation analysis for TGFbetaRII, IGFIIR, and BAX was performed in cancers with MSI. MMR protein status was examined by immunohistochemical analysis using a monoclonal antibody against hMSH2 and hMLH1.

RESULTS

MSI was observed in 16 of 22 patients (73%) and in 29 of 57 lesions (51%). High frequency MSI (MSI-H) was found often in patients with multiple cancers in the same organ (p = 0.042), especially in multiple gastric cancer patients (p = 0.038). In contrast, patients with multiple cancers in different organs had a tendency to show low frequency MSI (MSI-L) or microsatellite stable (MSS) phenotype. Both target gene mutation and decreased expression of MMR protein were found only in seven lesions of three patients with MSI at more than four microsatellite loci.

CONCLUSIONS

These results suggest that genetic instability may play an important role in the development of multiple gastrointestinal cancers but there may be different genetic alterations between multiple gastrointestinal cancers of the same and different organs.