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Kenji Kimura

Publications and source records attributed to Kenji Kimura.

At least 19 recordsLinked to original sources
PubMed2026

Tetraploid Caenorhabditis elegans embryos exhibit enhanced tolerance to osmotic stress.

Polyploidy is a widespread phenomenon in development and evolution and is frequently associated with altered cellular physiology and developmental robustness. However, how genome doubling influences an embryonic robustness to environmental stress remains poorly understood. Here, we investigated developmental traits and osmotic responses in tetraploid Caenorhabditis elegans embryos. Tetraploid animals exhibited increased body and tissue sizes and produced larger embryos than diploids, accompanied by moderately delayed development and partial embryonic arrest. When exposed to a range of osmotic environments, both diploid and tetraploid embryos swelled or shrank in response to external osmolarity. Strikingly, tetraploid embryos at the early stage maintained normal cell division across a broader range of osmotic conditions than diploids. Quantitative analyses further revealed that tetraploid embryos exhibited reduced cytoplasmic mass density, primarily reflecting lower protein concentration, while lipid and RNA levels remain unaffected. These compositional differences likely buffer cellular size fluctuations and underlie the enhanced osmotic tolerance of tetraploid embryos. Together, our findings demonstrate that genome doubling reshapes embryonic cellular physiology in a non-proportional manner to ploidy, thereby enhancing robustness during early development.

Animals↗
PubMed2006

Knockdown of mitochondrial heat shock protein 70 promotes progeria-like phenotypes in caenorhabditis elegans.

Mitochondrial heat shock protein 70 (mthsp70) functions as a mitochondrial import motor and is essential in mitochondrial biogenesis and energy generation in eukaryotic cells. HSP-6 (hsp70F) is a nematode orthologue of mthsp70. Knockdown of HSP-6 by RNA interference in young adult nematodes caused a reduction in the levels of ATP-2, HSP-60 and CLK-1, leading to abnormal mitochondrial morphology and lower ATP levels. As a result, RNA interference-treated worms had lower motility, defects in oogenesis, earlier accumulation of autofluorescent material, and a shorter life span. These are the major phenotypes observed during the aging of worms, suggesting that the reduction of HSP-6 causes early aging or progeria-like phenotypes. The amount of HSP-6 became dramatically reduced at the expected mean life span in not only wild-type but also in long and short life span mutant worms (wild-type, daf-2, and daf-16). Mitochondrial HSP-60 and ATP-2 were also reduced following the reduction of HSP-6 during aging. These results suggest that the reduction of HSP-6 causes defects in mitochondrial function at the final stage of aging, leading to mortality.

Adenosine Triphosphate↗
PubMed2006

Changes in vertebral wedging rate between supine and standing position and its association with back pain: a prospective study in patients with osteoporotic vertebral compression fractures.

STUDY DESIGN: Prospective consecutive series. OBJECTIVE: To analyze supine and standing radiographs and the association of back pain using subjective pain criteria. SUMMARY OF BACKGROUND DATA: It has been considered that there is little correlation between the degree of collapse of the vertebral body and the level of pain. In previous studies, however, measurements have only been based on supine radiographs. Although there were 2 authors who reported the results of supine lateral and standing lateral radiographs in patients with thoracolumbar vertebral fractures, as far as we know, there has not been any detailed report concerning the correlation between radiologic findings using supine and standing lateral radiographs and back pain. METHODS: We examined 100 consecutively treated patients, prospectively. Back pain and the supine and standing radiographs were assessed 1 month after injury. Changes in vertebral wedging rate (WR) from supine to standing position (Delta WR) was reported by the following equation: Delta WR = WR(standing)-WR(supine). RESULTS: The median age of the cohort was 75 years (range, 60-89 years). The median VAS of back pain at supine position, at standing position, and when standing erect was 13, 33, and 41, respectively. The median wedging rate on the supine and standing radiographs were 28% and 37%, respectively (P < 0.001). There was a significant correlation between Delta WR and back pain when standing erect (r = 0.79, P < 0.001). CONCLUSION: Changes in vertebral wedging rate between supine and standing position and its association with back pain may give a clue to the pathogenesis of pain from osteoporotic thoracolumbar vertebral compression fractures.

Aged↗
PubMed2006

Acute pancreatitis due to pancreatic arteriovenous malformation: 2 case reports and review of the literature.

Pancreatic arteriovenous malformation (AVM) is a relatively rare disease. Based on our literature search, 51 cases of pancreatic AVM have been reported since 1968. The gastrointestinal bleeding is the most common presenting symptom (24/51 cases [47%]). There were only 6 cases of pancreatitis in these cases. We describe 2 cases of acute pancretitis with pancreatic AVM. The patients who were diagnosed with acute pancreatitis were admitted to our hospital. Pancreatitis was considered to be caused by pancreatic AVM by some modalities of diagnostic imaging. The respective pancreatic AVM lesions of patients were resected to prevent the recurrence of pancreatitis. They are asymptomatic after the surgery. Pancreatic AVM is thought to be the one of the reasons for acute pancreatitis.

Acute Disease↗
PubMed2006

The expression of MUC4 and MUC5AC is related to the biologic malignancy of intraductal papillary mucinous neoplasms of the pancreas.

OBJECTIVE: Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas show heterogeneous proliferations with latent malignancy. Mucins (MUC) are high-molecular-weight glycoproteins, with an aberrant expression profile in various malignancies. Recently, MUC4 and MUC5AC expressions have been demonstrated to correlate with the unfavorable and the favorable prognosis of pancreatic duct cell carcinoma, respectively. However, little is known about these mucin expressions in IPMNs. METHODS: To clarify the role of MUC4 and MUC5AC expressions in IPMNs, the expression profiles of MUC4 and MUC5AC were investigated in 50 lesions from 17 specimens with 16 IPMNs by immunohistochemistry, using each of their specific antibodies. RESULTS: The expression of MUC4 was found in the lesions ranging from adenoma to cancer lesions of IPMNs, whereas it was undetectable in normal and hyperplastic lesions. Frequent expression of MUC4 is found in the higher grade of IPMNs (borderline and cancer lesions; 16/18 lesions, 94%). The differences were independently significant (P < 0.001) when the cutoff point was set between adenoma and borderline IPMNs. Similarly, frequent expression of MUC5AC was detected in the lesions from adenoma to cancer of IPMNs (32/34, 94%), whereas no intense expression was detected in normal or hyperplastic lesions. The significant difference was found when the cutoff point was set between hyperplasia and adenoma of IPMNs (P < 0.001). CONCLUSIONS: These results indicated that the expressions of MUC4 and MUC5AC are potential markers to distinguish adenoma or above malignant lesions of IPMNs from lesser malignant ones, respectively.

Adenocarcinoma, Mucinous↗
PubMed2005

MSX2 overexpression inhibits gemcitabine-induced caspase-3 activity in pancreatic cancer cells.

AIM: To evaluate the effect of MSX2 on gemcitabine-induced caspase-3 activation in pancreatic cancer cell line Panc-1. METHODS: Using V5-tagged MSX2 expression vector, stable transfectant of MSX2 was generated from Panc-1 cells (Px14 cells). Cell viability under gemcitabine administration was determined by MTT assay relative to control cell line (empty-vector transfected Panc-1 cells; P-3EV cells). Hoechst staining was used for the detection of apoptotic cell. Activation of caspase-3 was assessed using Western blotting analysis and direct measurement of caspase-3 specific activities. RESULTS: MSX2 overexpression in Panc-1 cells resulted in decreased gemcitabine-induced caspase-3 activation and increased cell viability under gemcitabine treatment in Px14 cells. CONCLUSION: MSX2 exerts repressive effects on gemcitabine-induced apoptotic pathway. This novel apoptosis-regulating function of MSX2 may provide a new therapeutic target for pancreatic cancer.

Antimetabolites, Antineoplastic↗
PubMed2005

Mutations in the serine protease inhibitor Kazal Type 1 (SPINK1) gene in Japanese patients with pancreatitis.

BACKGROUND/AIMS: Recent studies have shown an association between the N34S mutation in the serine protease inhibitor Kazal type 1 (SPINK1) gene and chronic pancreatitis (CP). We here examined the prevalence of SPINK1 mutations in Japanese patients with pancreatitis. METHODS: Genomic DNA was prepared from 80 Japanese patients with CP, 36 patients with acute pancreatitis (AP), and 165 healthy controls. All exons and the promotor region of the SPINK1 gene were amplified by the polymerase chain reaction, and directly sequenced. RESULTS: We found four types of mutation (N34S, IVS1-37T>C, -215G>A, and IVS3 + 2T>C) and two types of polymorphism (-253T>C and 272C>T). The N34S mutation cosegregated with IVS1-37T>C, and was present in 8 CP and 1 AP patients. The -215G>A mutation was in a complete linkage with IVS3 + 2T>C, and was present in 8 CP and 1 AP patients. The prevalences of [N34S; IVS1-37T>C] and [-215G>A; IVS3 + 2T>C] were significantly higher in patients with familial pancreatitis (38 and 13%, respectively) and with idiopathic CP (13 and 16%) than normal subjects (0.6 and 0%). In addition, the frequency of [N34S; IVS1-37T>C] mutation was higher in patients with autoimmune CP (33%). CONCLUSION: The SPINK1 gene mutations were associated with pancreatitis also in Japan.

Acute Disease↗
PubMed2005

Autoimmune pancreatitis with hepatic inflammatory pseudotumor.

We report a case of autoimmune pancreatitis (AIP) with hepatic inflammatory pseudotumor (IP). The patient was clinically diagnosed as having multiple metastatic tumors originated from cholangiocellular carcinoma as well as autoimmune pancreatitis and underwent left lobectomy of the liver. Histological examination showed a diffuse or dense lymphoplasmacytic infiltration with obliterating phlebitis but an absence of neoplastic proliferation both in the liver tumor and in the biopsy specimen of the pancreas. Abundant IgG4-positive plasma cells were seen in the lesions. This is the first case report that shows a simultaneous occurrence of hepatic IP and AIP, suggesting that these lesions appeared on the background of the recently proposed entity of IgG4-related systemic disease.

Autoimmune Diseases↗
PubMed2005

Detection of Cryptosporidium sp. Oocyst and Giardia sp. cyst in faucet water samples from cattle and goat farms in Taiwan.

A survey on the presence of Cryptosporidium oocyst and Giardia cyst in livestock drinking water as well as the urban tap water throughout Taiwan was carried out. Water examination for the presence of the protozoa was conducted by filtering through a PTFE membrane followed by immunomagnetic separation (IMS) and immunostaining the sediment with commercially available monoclonal antibody against Cryptosporidium and Giardia. Of the 55 different water samples from various sources examined, 2 were found to contain both of Cryptosporidium oocyst and Giardia cyst, 1 was found to contain Cryptosporidium oocyst only. These protozoa-positive water samples, originating from underground well and from the mountain spring, were also used as drinking water for livestock. However, no Cryptosporidium oocyst was found in the city tap water. This is the first report of Cryptosporidium oocyst and Giardia cyst being found in the drinking water for livestock.

Agriculture↗
PubMed2005

[Team communication needed in treatment for fixed prosthesis. 2) Opinion from dental technician's standpoint].

The fabrication of a fixed prosthesis is influenced by the communication between the dentist and the laboratory technician. Especially for tooth-colored restoration of anterior teeth, the laboratory technician has the difficult task of understanding the shade selected by the dentist and reproducing it in the final restoration. Conventional shade analysis techniques using the Vita shade guide often result in subjective analysis and a resultant miscommunication of color. Over the years, many different techniques including picture-taking, drawing of diagrams, and using multiple shade guides have been formulated to help overcome this problem. Recently, digital shade analysis systems have been designed to eliminate the subjectivity of color analysis and provide precise information for laboratory buildup and fabrication. However, even these techniques have not completely erased the difficulties involved in communicating the choice of the proper shade for tooth-colored restoration. Many dentists are only familiar with techniques they were taught in dental school and/or their residency program, and they are unaware of other, superior methods that can be used. This review introduces various shade analysis systems that can be performed in dental clinical practice. Further, it highlights the importance of communication between the dentist, technician, and patient for the fabrication and delivery of aesthetic restorations.

Color↗
PubMed2005

[Neurotensin].

Explore the source record for details and available documents.

Animals↗
PubMed2005

Study on cyclospora cayetanensis associated with diarrheal disease in Nepal and Loa PDR.

A study of diarrheal diseases associated with Cyclospora cayetanensis was conducted in Nepal and Lao PDR. A total of 2083 samples were included in this study. Samples in Nepal were collected from October 1999 to August 2002 whereas samples in Lao PDR were collected from February 2002 to June 2003. C. cayetanensis was detected by direct microscopy using ultraviolet and differential interference contrast microscopy. The overall positive rate in Nepal was 9.2% (128/ 1397). A higher positive rate was observed in children aged 10 years and under (11.1%) and was lowest in the age group of 51-60 years (3.1%). A significantly higher positive rate was observed in the summer (rainy season) (12.6%) with the lowest prevalence in the spring (dry season) (1.8%) (p < 0.05). The positive rate was closely associated with rainfall (ml/month). Interestingly, only one of the total 686 samples (0.1%) from Lao PDR was found to be positive for Cyclospora oocysts.

Adolescent↗
PubMed2004

Comparison of three microscopic techniques for diagnosis of Cyclospora cayetanensis.

Cyclospora cayetanensis oocysts in the feces of humans from Kathmandu, Nepal were identified on the basis of their size and other morphological characteristics. We compared the detection of C. cayetanensis oocysts in the feces using three microscopic techniques such as formalin-ether sedimentation, sucrose centrifugal floatation, and direct smear. Standard procedures were used for the formalin-ether sedimentation and the sucrose centrifugal floatation techniques using 0.5 g of feces, however, the direct smear technique was performed using 10 microl of fecal suspension (0.005 g of feces) and observed under the fluorescent microscope. Of the 403 samples examined, 21 samples were positive for oocysts by all three techniques. Therefore, in these 21 samples, the number of oocysts recovered by the three techniques were compared. The highest number of oocyst was obtained by the sucrose centrifugal floatation technique. In contrast, the formalin-ether sedimentation technique was found to be the least reliable concentration technique for the detection of Cyclospora in human feces. Surprisingly, the direct smear technique was found to be an effective and rapid technique for diagnosis of C. cayetanensis making it a technique of choice for routine epidemiological investigation of the prevalence of this infection in human populations.

Centrifugation↗
PubMed2004

Inosine alleviates rat caerulein pancreatitis and pancreatitis-associated lung injury.

BACKGROUND: Recent studies have shown that inosine, a purine nucleoside produced during the breakdown of adenosine, has immunomodulatory and anti-inflammatory properties. The aim of this study was to examine the effects of inosine on the course of acute pancreatitis. METHODS: Edematous pancreatitis was induced by the intraperitoneal injection of caerulein (50 micro g/kg), seven times, at 1-h intervals, in male Wistar rats (caerulein pancreatitis). Inosine (100 mg/kg) was administered 30 min before or 1 h after the first injection of caerulein. The effects of inosine on the severity of pancreatitis were assessed by serum amylase, pancreatic edema (wet/dry ratio), myeloperoxidase activity, cytokine-induced neutrophil chemoattractant-1 concentrations, and histological changes. RESULTS: Prophylactic administration of inosine significantly decreased the elevation of serum amylase, myeloperoxidase activity, and cytokine-induced neutrophil chemoattractant-1 concentrations in the pancreas and the lung. Inosine did not significantly affect edema formation. Histologically, vacuole formation in pancreatic acinar cells, infiltration of inflammatory cells in the pancreas and the lung, and alveolar wall thickening in the lung were reduced. Inosine improved the histological findings and reduced myeloperoxidase activity even if it was administered 1 h after the first injection of caerulein. CONCLUSIONS: Inosine reduced the severity of acute pancreatitis, suggesting a possible application of this compound in the treatment of acute pancreatitis.

Acute Disease↗
PubMed2004

Parasites detected from diarrheal stool samples collected in Nepal.

Intestinal parasites were investigated in 396 diarrheal stool samples collected from individuals aged 1 to 68 years (males: 239 and females: 157) in Nepal. Samples were collected at different medical centers located in Kathmandu and from two public schools in a village setting in Kathmandu Valley and outside, during October 1999 to January 2001. The stool samples were mixed with 2% dichromate solution and transported to Japan for investigations. Parasites were detected by employing the formal-ether sedimentation technique. Of a total of 396 fecal samples investigated, 193 (49%) were positive for some kind of parasite. Altogether, 15 species of parasites were detected. Giardia intestinalis topped the list of protozoa, whereas Trichuris trichiura was the most frequently detected among helminth parasites. Of the 193 positive samples, 109 (56%) had single parasite infections, whereas 84 (43%) had multiple infections with a maximum of five species. Of the total positive, 45 (23%) had both protozoa and helminths whereas 37 (19%) had only protozoa. Females (52%) and children (15 years and under) (52%) had a marginally higher prevalence compared with males (46%) and adults (45%), respectively (p > 0.05). Samples collected from two public schools in a village setting inside Kathmandu Valley and outside had a significantly higher positive rate compared with those observed in individuals visiting different medical centers in the city and suburban areas in Kathmandu (p < 0.05).

Adolescent↗
PubMed2004

Epidemiological survey of intestinal parasitic infections of diarrhoeal patients in Nepal and Lao PDR.

Intestinal parasitological survey was conducted to clarify the distribution of intestinal parasites in Nepal and Lao Peoples' Democratic Republic (Lao PDR) from 2001 to 2003. A total of 401 diarrheal fecal specimens were collected from patients aged one to 75 years (250 from Nepal and 151 from Lao PDR). The specimens were examined using the formalin-ether sedimentation (FES) and sucrose centrifugal flotation (SCF) techniques. Nine species (3 Nematoda, 1 Cestoda, and 5 Protozoa) of parasites were recovered from Nepal, whereas seven species (3 Nematoda, 1 Trematoda, and 3 Protozoa) from Lao PDR. Of the parasites detected, (14.4%) was the most common in Nepal, and was Opisthorchis viverrini (29.8%) in Lao PDR. Infection rates were markedly different among age groups in both countries; higher rates were observed in age groups of 10-29 years than in 0-9 years group. Scanning electron microscopic observation revealed that trematoda eggs recovered from Lao PDR were identified as O. viverrini, which could not be done by a light microscope.

Adolescent↗