Biomedical subjects

K Nishimura

Publications and source records attributed to K Nishimura.

At least 109 records · Page 6Linked to original sources

PubMed2001

Percutaneous nucleotomy in elite athletes.

Percutaneous nucleotomy in elite athletes is considered a minimally invasive treatment of lumbar disc herniation. However, long-term effectiveness has not been established by careful follow-up studies. This article evaluates the outcome of percutaneous nucleotomy in elite athletes who have undergone the procedure. Thirty elite athletes with lumbar disc herniation who underwent percutaneous nucleotomy and had been followed for at least 2 years were compared with a matched group of 42 nonathletes. The outcome in athletes was worse than in nonathletes. Early return to vigorous sports activity in less than 3 months correlated with increased symptoms. Similarly, more extensive resection of disc material was associated with an unexpected rapid worsening of the outcome and the lower rate of return to preoperative sports. Patient selection and postoperative management of athletes and nonathletes undergoing percutaneous nucleotomy should be the same, and the procedure in athletes is probably not worthwhile if they do not obey postoperative management such as the timing of return to sports activity.

Adolescent↗

PubMed2001

Treatment of osteoporotic late collapse of a vertebral body of thoracic and lumbar spine.

Although osteoporotic late collapse of a vertebral body is a common infirmity of old age, it has not been well studied, and no consensus regarding treatment of this condition has been reached. Forty-five patients with osteoporotic late collapse of a vertebral body were classified into six types based on the appearance on the lateral projection of a radiograph and the presence or absence of neurologic symptoms and were evaluated on imaging and clinical outcome. We concluded that the treatment of osteoporotic late collapse of a vertebral body can be individualized based on several factors such as the presentation of the fracture and neurologic condition. Conservative treatment can be selected in patients without neurologic involvement who have the concave type with anterior spur or sclerotic change or flat type with uniform compression of collapse. If the patients in those types of collapse show neurologic involvement, decompression and reconstruction through a posterior approach, including an eggshell procedure and the short segment pedicle screw system, are more suitable. Anterior decompression with anterior strut bone graft and anterior spinal instrumentation should be done for wedged type of collapse regardless of neurologic status.

Aged↗

PubMed2001

Nucleus pulposus allograft retards intervertebral disc degeneration.

Autogenous implantation of nucleus pulposus or nucleus pulposus cells that were activated by coculture retards intervertebral disc degeneration, but harvesting such grafts causes disc degeneration at the donor site. This study examined whether nucleus pulposus allografts similarly retard disc degeneration and whether such allografting induces immunologic rejection. Japanese White rabbits served as donors and recipients for allografts. Lumbar disc degeneration was induced by aspirating the nucleus pulposus. Two weeks later, intact nucleus pulposus or nucleus pulposus cells were injected and compared with a sham procedure and normal control. The recipients' discs were examined histologically and immunologically at intervals for 16 weeks. Discs receiving an intact nucleus pulposus showed the least degeneration, followed by discs receiving nucleus pulposus cells, both of which were better than no treatment. These findings correlated directly with the intensity of immunochemical staining for Type II collagen. Allogeneic grafts did not induce any appreciable host-versus-graft response. Injection of nucleus pulposus and nucleus pulposus cells retards intervertebral disc degeneration. However, injection of intact nucleus pulposus is more effective than injection of nucleus pulposus cells alone. The intercellular matrix plays an important, but poorly understood, role in preserving intervertebral discs.

Animals↗

PubMed2001

Molecular phylogenetics of the genus Rhodotorula and related basidiomycetous yeasts inferred from the mitochondrial cytochrome b gene.

Phylogenetic relationships of basidiomycetous yeasts, especially of the genus Rhodotorula, were studied using partial sequences of the mitochondrial cytochrome b gene. The results demonstrated that the basidiomycetous yeasts under investigation distributed into two main clusters: one containing Tremellales, Filobasidiales and their anamorphs and the other containing Ustilaginales, Sporidiales and their anamorphs. This clustering in turn correlates with cell wall biochemistry, presence or absence of xylose, and septal ultrastructure, dolipore or simple pore. Bullera, Bulleromyces, Filobasidiella, Cryptococcus and Trichosporon, yeasts of the former cluster, contain xylose in the cell wall and have dolipore septa. In contrast yeasts of the latter cluster, which included Bensingtonia, Erythrobasidium, Leucosporidium, Malassezia, Rhodosporidium, Rhodotorula, Sporidiobolus, Sporobolomyces and Ustilago, have no xylose in the cell wall and have a simple pore septum. Yeasts of the latter group could be further divided into four clades (A-D). Species of Rhodotorula were distributed in all of these clades, indicating the polyphyletic nature of the genus. A limited number of Rhodotorula species demonstrated identical sequences, for example Rhodotorula bacarum and Rhodotorula foliorum, Rhodotorula fujisanensis and Rhodotorula futronensis, Rhodotorula glutinis var. dairenensis and Rhodotorula mucilaginosa. However, all the other test species of the genus Rhodotorula were well separated based on their 396 bp nucleotide sequences. These results demonstrate the effectiveness of the use of cytochrome b sequences for both species identification and the study of phylogenetic relationships among basidiomycetous yeasts.

Amino Acid Sequence↗

PubMed2001

Crystallization and preliminary X-ray analysis of a novel pectolytic enzyme, polymethoxygalacturonase SX1 from Trichosporon penicillatum.

A novel pectolytic enzyme, polymethoxygalacturonase SX1 from Trichosporon penicillatum, with a molecular weight of 36 kDa was crystallized by the hanging-drop vapour-diffusion method using polyethylene glycol 1000 as a precipitant. The crystals belonged to the monoclinic space group C2, with unit-cell parameters a = 165.6, b = 61.0, c = 48.7 A, beta = 93.1 degrees. The calculated V(M) based on one molecule per asymmetric unit was 3.40 A(3) Da(-1). A native data set was collected to 2.08 A resolution from a crystal on a Cu Kalpha rotating-anode X-ray source. A molecular-replacement solution was obtained using the program AMoRe and the structure of endopolygalacturonase II from Aspergillus niger as a model.

Crystallization↗

PubMed2001

Purification, crystallization and preliminary X-ray diffraction analysis of the fructose-1,6-/sedoheptulose-1,7-bisphosphatase of Synechococcus PCC 7942.

Fructose-1,6-/sedoheptulose-1,7-bisphosphatase of Synechococcus PCC 7942, overexpressed from Escherichia coli, has been purified and crystallized by the hanging-drop vapour-diffusion method using ammonium sulfate as a precipitant. The crystals were monoclinic, with unit-cell parameters a = 80.1, b = 84.2, c = 104.3 A, beta = 101.7 degrees. They belonged to space group P2(1) and diffracted to at least 2.2 A resolution. The calculated V(M) value, based on a tetramer in the asymmetric unit, was 2.2 A(3) Da(-1).

Crystallization↗

PubMed2001

Molecular characterization of new clinical isolates of Candida albicans and C. dubliniensis in Japan: analysis reveals a new genotype of C. albicans with group I intron.

The genetic diversity of recent clinical isolates of Candida albicans in Japan was studied on the basis of amplified DNA band lengths determined with a specific PCR primer reported to have been designed to span a transposable intron region in the 25S rRNA gene. Our analyses of 301 clinical isolates of C. albicans showed that they could be classified into five genotypes: genotype A (172 isolates), genotype B (66 isolates), genotype C (56 isolates), genotype D (C. dubliniensis; 5 isolates), and a new genotype (designated genotype E; 2 isolates). The new genotype E was characterized to have a group I intron-like sequence, which is longer than hitherto reported ones and which has a nucleotide sequence length of 962 bp. Our analysis of the 962-bp sequence indicated that it is composed of an intron similar to that of C. dubliniensis of 621 bp with a 341-bp insertion. Analysis of the sequence of the internal transcribed spacer (ITS) region of the genotype E strain showed that its sequence is identical to those of strains of other genotypes, with only a few base substitution differences. Throughout the study, the possible horizontal transfer of the group I intron between C. dubliniensis and C. albicans was suggested. A high degree of correlation between the presence of a group I intron in C. albicans genotype E and susceptibility to the antifungal agent flucytosine was observed. The five isolates of C. dubliniensis examined in the present study showed genetic diversity when they were compared by randomly amplified polymorphic DNA fingerprinting pattern analysis, and this diversity was also confirmed by the analysis of ITS region sequences.

Antifungal Agents↗

PubMed2001

Identification, classification, and phylogeny of the pathogenic species Exophiala jeanselmei and related species by mitochondrial cytochrome b gene analysis.

We analyzed a 402-bp sequence of the mitochondrial cytochrome b gene of 34 strains of Exophiala jeanselmei and 16 strains representing 12 related species. The strains of E. jeanselmei were classified into 20 DNA types and 17 amino acid types. The differences between these strains were found in 1 to 60 nucleotides and 1 to 17 amino acids. On the basis of the identities and similarities of nucleotide and amino acid sequences, some strains were reidentified: i.e., two strains of E. jeanselmei var. hetermorpha and one strain of E. castellanii as E. dermatitidis (including the type strain), three strains of E. jeanselmei as E. jeanselmei var. lecanii-corni (including the type strain), three strains of E. jeanselmei as E. bergeri (including the type strain), seven strains of E. jeanselmei as E. pisciphila (including the type strain), seven strains of E. jeanselmei as E. jeanselmei var. jeanselmei (including the type strain), one strain of E. jeanselmei as Fonsecaea pedrosoi (including the type strain), and one strain of E. jeanselmei as E. spinifera (including the type strain). Some E. jeanselmei strains showed distinct nucleotide and amino acid sequences. The amino-acid-based UPGMA (unweighted pair group method with the arithmetic mean) tree exhibited nearly the same topology as those of the DNA-based trees obtained by neighbor joining, maximum parsimony, and maximum likelihood methods.

Cytochrome b Group↗

PubMed2001

Typing of Candida albicans isolates by sequence analysis of the cytochrome b gene and differentiation from Candida stellatoidea.

Including type strains, mitochondrial cytochrome b genes of 32 strains of Candida albicans and 6 strains of Candida stellatoidea, presently treated as a synonym for C. albicans, were partially sequenced. Analysis of 396-bp nucleotide sequences of the strains under investigation divided C. albicans isolates into three types: type I, type II, and type III; however, strains of C. stellatoidea represented distinct type IV isolates. Deduced amino acid sequences of type I, type II, and type III were identical and differed from that of type IV by one amino acid. Genotypes (rDNA type) of the test strains were also checked. Cytochrome b typing did not correlate with genotyping, and different genotypes occurred for one cytochrome b type. This study shows that cytochrome b gene sequences are useful for analyzing the genetic relatedness of C. albicans isolates and effective for differentiating C. stellatoidea from C. albicans.

Amino Acid Sequence↗

PubMed2001

Antifungal susceptibilities, varieties, and electrophoretic karyotypes of clinical isolates of Cryptococcus neoformans from Brazil, Chile, and Venezuela.

One hundred clinical isolates of Cryptococcus neoformans from human immunodeficiency virus (HIV)-infected and non-HIV-infected patients from Brazil, Chile, and Venezuela were separated according to varieties and tested for antifungal susceptibility. A high susceptibility to antifungal agents was observed among all the isolates. The electrophoretic karyotyping of 51 strains revealed good discrimination among Cryptococcus neoformans var. neoformans strains.

AIDS-Related Opportunistic Infections↗

PubMed2001

Colonization with Schizophyllum commune of localized honeycomb lung with mucus.

We report a surgical case involving localized honeycomb lung with mucus, caused by colonization of a Schizophyllum commune, which displayed a tumorous shadow in the right upper mediastinum. A 74-year-old male with a history of tuberculosis in the 1970s was referred to Chiba University Hospital (Chiba, Japan) with an abnormal shadow evident in the chest roentgenogram. A transbronchial biopsy failed to yield a definite diagnosis. We resected the right upper lobe, which was found to contain a consolidative lesion filled with viscous mucus in the right upper lobe adjacent to the right upper mediastinum. Microscopic examination revealed a honeycomb lung formation with mucus in the destroyed space. Culture of the mucus yielded a whitish filamentous fungus, positively identified as S. commune. This is the first report of S. commune leading to a deposit of mucus and the formation of a consolidative lesion in the destroyed lung.

Aged↗

PubMed2001

Oral combination of cyclophosphamide, uracil plus tegafur and estramustine for hormone-refractory prostate cancer.

OBJECTIVE: To evaluate the clinical usefulness of an oral combination of cyclophosphamide, uracil plus tegafur (UFT) and estramustine in the treatment of patients with hormone-refractory prostate cancer (HRPC). METHODS: Twenty-one patients were treated with oral administration of cyclophosphamide (100 mg/day), UFT (400 mg/day) and estramustine phosphate (560 mg/day). The median age of the patients was 70 years. Twelve patients had symptomatic bone metastasis, 6 had asymptomatic bone metastasis, 5 had lymph node metastasis, while 2 had only biochemical progression evaluated by prostate-specific antigen (PSA). RESULTS: Twelve (57%) out of 21 patients showed a PSA decline of 50% or greater. The median response duration was 7 months (range 2-15 months). Among the 20 patients assessable for bone pain, 2 (10%) improved, 12 (60%) remained stable and 6 (30%) progressed. Among the 10 patients assessable for bone metastasis, 1 (10%) improved, 5 (50%) were stable and 4 (40%) progressed on bone scan. Among 3 patients assessable for measurable disease (lymph node metastasis), 2 (67%) showed partial response and 1 (33%) progression. Most toxicities were mild. CONCLUSIONS: The combination of cyclophosphamide, UFT and estramustine is an active and well-tolerated regimen for HRPC. To evaluate the survival benefit, further randomized studies are required.

Administration, Oral↗

PubMed2001

4-Hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF) production in simple media by lactic acid bacterium, Lactococcus lactis subsp. cremoris IFO 3427.

4-Hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF) was detected in simple media prepared with heated sugar and amino acid solution as a result of the Maillard reaction. However, an increase in the amount of HDMF was observed in the media fermented by Lactococcus lactis subsp. cremoris IFO 3427. 4-Hydroxy-2(or 5)-ethyl-5(or 2)-methyl-3(2H)-furanone (HEMF) was not detected in all the simple media examined in this study.

Journal Article↗

PubMed2001

Insecticidal and neural activities of candidate photoaffinity probes for neonicotinoid binding sites.

Photoreactive derivatives of imidacloprid and its nitromethylene analogue were synthesized as candidate photoaffinity probes for identifying the amino acid residues of nicotinic acetylcholine receptors (nAChRs) that interact with the neonicotinoid insecticides. When the candidate probes were injected into American cockroaches, the nerve cord neural activity initially increased, then ceased and death of the insect followed. Both the nerve cord and toxicity were enhanced by changing the photoreactive substituent from the para position to the meta position on the spacer benzyl moiety. When tested on a Drosophila SAD/chicken beta2 hybrid, recombinant nAChR expressed in Xenopus oocytes, the nitromethylene candidate probes showed agonist activity similar to that previously observed for imidacloprid.

Anabasine↗

PubMed2001

Role of reticulocytes on gametocytogenesis in chickens infected with Leucocytozoon caulleryi.

Reticulocytes, known as late polychromatic erythrocytes, were induced in blood of chickens infected with Leucocytozoon caulleryi by bleeding when the second-generation merozoites were released into the blood from the second-generation schizonts. The second-generation merozoites preferentially invaded into reticulocytes and developed to stage II gametocytes. Enhanced development of stage II gametocytes to mature gametocytes was observed in the reticulocytes in vivo and in vitro in the bleeding group. Nevertheless, invasion of reticulocytes by the second-generation merozoites was not considered to be absolutely necessary for the development of gametocytes.

Animals↗

PubMed2001

The risks and benefits of percutaneous nucleotomy for lumbar disc herniation. A 10-year longitudinal study.

Percutaneous nucleotomy is a relatively new technique for treating lumbar disc herniation. There is no agreement as to the volume of disc material to be removed. A long-term study of clinical and radiological data from patients treated by percutaneous nucleotomy was designed to identify the factors associated with favourable and unfavourable outcomes. We studied 42 patients for at least ten years; the mean follow-up was 10.9 years. They were divided into two subgroups to assess the value of preserving the nucleus pulposus in the central area of the disc. The overall success rate for both subgroups was 50%. A decrease in disc height on plain radiography and a decrease in signal intensity on MRI were observed more infrequently in patients in whom the nucleus pulposus in the central area of the disc had been preserved, than in those in whom it had been extensively removed. These adverse radiological findings correlated closely with increased low back pain during the first one to two years after operation and a poorer overall outcome. We conclude that percutaneous nucleotomy is most likely to be successful when the central area of the disc is preserved.

Adolescent↗

PubMed2001

Evaluation of simultaneous excision of pancreatic cancer and the surrounding blood vessels.

Of the 139 patients who underwent excision for invasive cancer in the pancreatic duct at Kurume University Hospital between January 1965 and December 1998, the subjects were 38 patients in whom blood vessels around the cancer were simultaneously excised. The surgical methods were pancreatoduodenectomy (PD) in 31 patients, distal pancreatectomy (DP) in 5, and total pancreatectomy (TP) in 2. The excised blood vessels were the portal vein alone in 32 patients, the artery alone in 1, and both portal vein and artery in 5. Excision of the portal vein was performed by circumcision in 25 patients and by segmentectomy in 12. The range of circumcision was 1.0-7.0 cm (mean, 3.5 +/- 1.4 cm), and the blocking time of the portal vein was 8-36 min (mean, 19.5 +/- 8.8 min). Of the 25 patients who underwent circumcision, reconstruction was performed by end-to-end anastomosis in 23 and by transplantation of the autologous vein between the ends in 2. Of the 12 patients who underwent segmentectomy, direct suture was performed in 10, and transplantation of an autologous vein patch was performed in 2. Postoperative complications occurred in 14 of the 32 patients. In 5 of the 6 patients who underwent excision of the artery, reconstruction was performed by end-to-end anastomosis in 3 and by transplantation of the autologous vein between the ends in 2. Postoperative complications did not occur in the patient who had undergone excision of the artery alone, but 4 of the 5 patients who had undergone simultaneous excision of the portal vein and artery had postoperative complications, of whom 2 died during the period of hospitalization. Three patients with pv0, pv1 or pv2 survived for more than 3 years. Because some of the patients who had undergone excision of the portal vein alone survived for a long time and this method is relatively safe, this surgery can be generally applied, but simultaneous excision of the portal vein and artery should be carefully applied because the incidences of postoperative complications and death during the period of hospitalization are high. With the development of surgical techniques and postoperative control, simultaneous excision of pancreatic cancer and the surrounding blood vessels has become safe, but this method should only be applied to patients who have the potential to recover completely.

Hepatic Artery↗

PubMed2001

Xanthogranulomatous cholecystitis.

Seven cases of xanthogranulomatous cholecystitis are presented, and their clinicopathological appearance is described. Three men and 4 women with xanthogranulomatous cholecystitis, aged 53-72 years old, were reviewed. Five patients had had previous attacks of acute cholecystitis lasting from 3 weeks to 6 months. Abdominal ultrasonography was performed in all patients, and computed tomography in 5 patients. Cholelithiasis and sludge were present in all patients. The gallbladder wall was thickened in all patients. On computed tomography, one patient showed no abnormal finding, and 4 patients had abnormal findings such as increased wall thickness and irregularity, and pericholecystic abnormalities. A diagnosis of gallbladder carcinoma was made preoperatively in 1 patient. During laparotomy, the gallbladders in all patients showed signs of chronic cholecystitis, and cholecystectomies were performed. Histological findings showed xanthogranulomatous cholecystitis, and 4 patients had stones in the gallbladder wall. Despite the characteristic histologic appearance of xanthogranulomatous cholecystitis, radiologic findings are nonspecific, varying from signs observed in other forms of cholecystitis to the appearance of a gallbladder neoplasm. We report here 7 cases of xanthogranulomatous cholecystitis and review the literature.

Aged↗