Biomedical subjects

I Nakamura

Publications and source records attributed to I Nakamura.

At least 73 records · Page 4Linked to original sources

PubMed2000

Beneficial effects of interferon-alpha in a case with Behçet's disease.

At the age of 20 years, a Japanese man with recurrent oral aphthae, genital ulcers, folliculitis, erythema nodosum, episodic arthritis and epididymitis was diagnosed as having Behcet's disease (BD) in 1966. He has had active ocular manifestations of BD since 1990. These symptoms recurred and never abated for a long period of time. A right renal cell carcinoma developed and he underwent right nephrectomy in April 1996. Treatment with interferon-alpha was started from June 1996 as supplemental chemotherapy. No active phase developed during administration of IFN-alpha. We suggest that IFN-alpha may play a role as an immunomodulatory agent in BD.

Adjuvants, Immunologic↗

PubMed2000

Diagnostic value of a bedside test for cardiac troponin T in the patient with chest pain presenting to the emergency room.

Identification of patients with acute chest pain due to acute coronary syndrome is a common and difficult challenge for emergency physicians. A prospective study was conducted to assess the diagnostic value of a bedside test of cardiac troponin T in the emergency room setting. Forty-nine consecutive patients, who visited the emergency room within 6 hours of the onset of acute chest pain, were enrolled. Of the 26 patients who were ultimately diagnosed as having acute coronary syndrome, seven patients (27%) had positive cardiac troponin T assay results, whereas none of the patients without acute coronary syndrome had positive results (0%). For patients with acute coronary syndrome who presented later than 3 hours after the onset (n = 4), the test was positive in all cases (positive predictive value: 100%, negative predictive value: 100%, p < 0.01). However, the positive rate was only 14% for those who presented earlier than 3 hours after the onset (n = 22) (positive predictive value: 100%, negative predictive value: 47%, p = 0.84). In conclusion, bedside troponin T test results should be evaluated considering the time interval from the onset of chest symptoms.

Adult↗

PubMed2000

Changes in calcium metabolism and bone demineralization after orthotopic intestinal neobladder creation.

PURPOSE: We evaluated calcium metabolism and bone demineralization by measuring specific markers for bone reabsorption and bone mineral density in patients with an intestinal neobladder. MATERIALS AND METHODS: We studied 33 men 55 to 72 years old who underwent creation of an orthotopic sigmoid (23), ileocolic (8) or ascending colon (2) neobladder after cystectomy. Mean followup plus or minus standard deviation (SD) was 28.4+/-30.1 months (range 4 to 114). Serum electrolytes and arterial blood gases were measured. As markers of bone absorption we assayed urinary pyridinoline, deoxypyridinoline and N-terminal pyridinoline cross-linked telopeptides, and serum pyridinoline cross-linked C-terminal telopeptide of type I collagen. Bone mineral density of the spine and femur was determined by dual x-ray absorptiometry. RESULTS: Mean blood pH plus or minus SD was 7.38+/-0.04 (range 7.29 to 7.43). Mean plasma bicarbonate was 22.9+/-3.4 mmol./l. and mean base excess was -1.63+/-3.61 mmol./l. Serum sodium, potassium, calcium, alkaline phosphatase and phosphate were normal in most patients. Mean serum chloride was 108.0+/-3.5 mEq./l., and was elevated in 9 of the 33 patients (27.3%). Serum intact parathyroid hormone was normal in all patients, osteocalcin was increased in 2 and 1alpha, 25-dihydroxyvitamin D3 was decreased in 2. Pyridinoline cross-linked C-terminal telopeptide of type I collagen was higher in 19 of 33 cases (57.6%) and N-terminal pyridinoline cross-linked telopeptides were elevated in 6 (18.2%). Pyridinoline and deoxypyridinoline were higher than normal in 19 (57.6%) and 7 (21.2%) patients, respectively. C-terminal telopeptide of type I collagen and deoxypyridinoline significantly correlated with serum pH (p = 0.017 and 0.0418, respectively). Z score for the bone mineral density of L2 to L4, the femoral neck and Ward's triangle was -0.350+/-1.031, -0.82+/-0.99 and -0.94+/-1.01, respectively. CONCLUSIONS: In patients with a neobladder of intestinal segments metabolic acidosis results in increased bone absorption and decreased bone mass. Thus, attention should be given to bone metabolism in patients with even mild acidosis after orthotopic neobladder creation.

Aged↗

PubMed2000

Sigmoid neobladder in women after radical cystectomy.

PURPOSE: Neobladder reconstruction using an intestinal segment is the common procedure of choice in men after cystectomy. Recently this procedure has been extended to women. We present our surgical and functional experience with the sigmoid neobladder in women. MATERIALS AND METHODS: A total of 11 women 49 to 74 years old (mean age plus or minus standard deviation 60 +/- 8.5) with transitional cell carcinoma of the bladder underwent lower urinary tract reconstruction with a modified sigmoid neobladder after nerve and urethral support sparing cystectomy. After at least 3 months voiding pattern and continence status were evaluated. Pressure flow studies and uroflowmetry were performed, the urethral pressure profile and neocystourethral angle were measured, and blood chemistry was analyzed. RESULTS: After at least 3 months complete daytime continence was achieved in 2 patients, while 8 had mild stress incontinence. At night 8 of the 11 women (72.7%) were continent with or without voiding at regular intervals. All except 1 patient voided to completion. Of the 2 patients with complete continence 1 needed clean intermittent catheterization 4 months postoperatively. Mean maximal urinary flow was 19.9 +/- 10.5 ml. per second. Excluding the woman who required catheterization mean residual urine volume was 15 +/- 13.7 ml. Postoperatively maximal urethral pressure was slightly lower and functional urethral length was about 10 mm. shorter than preoperatively. The mean neocystourethral angle was 131.9 +/- 21.7 degrees. Mean pH, bicarbonate and base excess were 7.38 +/- 0.03, 23. 48 +/- 2.34 mmol./l. and -0.92 +/- 2.50, respectively. CONCLUSIONS: After nerve and urethral support sparing cystectomy a modified sigmoid neobladder may be constructed in women to obtain satisfactory continence and voiding results.

Aged↗

PubMed2000

[Accidental decrease in the air flow during air/oxygen sevoflurane anesthesia].

We describe our experience of an accidental decrease in the air flow during air/oxygen sevoflurane anesthesia. According to the malfunction of an air compressor system, dehydration of the compressed air was inadequate, and the wet air was delivered to the anesthesia machine. The moisture was formed at a flow control valve to cause a gradual decrease in the air flow. The low-pressure alarm did not work at that time, because the pressure of the air supply was normal. There are two types of medical air, one is produced from the ambient air by air compressor system and another is the synthetic air which is a mixture of oxygen and nitrogen. Although the synthetic air is always dry and clean, the former contains dust, bacteria, and moisture. There is a possibility that all of these particles cannot be excluded before use. Accordingly, we must check the air compressor system routinely when a source of the compressed air is used.

Air↗

PubMed2000

[A comparative study on the clinical utility of cefozopran and cefpirome against complicated urinary tract infections].

Aiming at evaluating the utility of cefozopran (CZOP) against complicated urinary tract infections with the velocity of eradication of causal bacteria in early treatment and clinical efficacy by new criteria of UTIs, a comparative study was conducted using cefpirome (CPR) as the control drug. CZOP and CPR were administered by intravenous drip infusion at a dose of 1 g twice daily. The duration of treatment was for 5 days. The study method involved randomized assignment of the subjects to either group CZOP or group CPR. The results were as follows: 1. Of a total of 80 cases treated, 65 (CZOP group--32 cases, CPR group--33 cases) were evaluated for efficacy. 2. The overall clinical efficacy evaluation according to the criteria proposed by Japanese UTI Committee rated the CZOP group as 90.6% (29/32), and the CPR group as 90.9% (30/33), with no significant difference between the 2 groups. Clinical efficacy evaluated by attending physicians rated the CZOP group as 93.8% (30/32) and the CPR group as 90.9% (30/33). There was no significant difference between the 2 groups. 3. The efficacy rates to pyuria on day 2 were 26.7% and 0% for the CZOP group and the CPR group, respectively, indicating a higher efficacy rate for the former (p < 0.05). Those on after treatment were 59.4% and 54.5% for the CZOP group and the CPR group, respectively, with no significant difference between the 2 groups. 4. Regarding the bacteriological effect, the eradication rates of both groups were over 90% on day 1 and after treatment. There was no significant difference between the 2 groups. 5. Side effects occurred in 1 case (2.6%) out of 39 in the CZOP group and in 1 case (2.4%) out of 41 in the CPR group. Laboratory test value fluctuation was noted in 8 (20.5%) of 39 cases in the CZOP group and 11 (26.8%) of 41 cases in the CPR group. There was no significant difference between the 2 groups. The results indicate that CZOP achieves an early efficacy to pyuria, and is as useful as CPR against complicated urinary tract infections.

Adult↗

PubMed1999

Palladium-Catalyzed Hydroalkoxylation of Methylenecyclopropanes.

Hydroalkoxylations proceed by a different path than transition metal catalyzed hydrostannations and hydrosilylations. In the reaction of methylenecyclopropanes 1 with alcohols 2 in the presence of Pd(0), the distal bond in the cyclopropane ring is cleaved, and allyl ether 3 is formed selectively. R(1)=n-C(7)H(15), PhCH(2)CH(2); R(2)=H, PhCH(2)CH(2); R(3)=PhCH(2), CF(3)CH(2), Et(3)Si, n-C(4)H(9), etc.

Journal Article↗

PubMed1999

Sensitive high-performance liquid chromatographic determination of nifedipine in cat plasma following improved sample treatment.

A simple, easy and accurate reversed-phase high-performance liquid chromatographic method is described for the determination of nifedipine in cat plasma. The procedure involves extraction of nifedipine from plasma using a Sep-Pak C18 cartridge and ultraviolet detection at 350 nm. The present method provides the required reproducibility and sensitivity for the determination of low concentrations of nifedipine without interference from plasma components or photodegradation products. The method was validated over the range 1-50 ng/ml nifedipine. Accuracy and precision were, respectively, 97% or more and 5% or less over the concentration range examined. The minimum quantifiable concentration of nifedipine was found to be 1 ng/ml.

Animals↗

PubMed1999

Interleukin 1 induces multinucleation and bone-resorbing activity of osteoclasts in the absence of osteoblasts/stromal cells.

Interleukin-1 (IL-1) is one of the most potent bone-resorbing factors involved in bone loss associated with inflammation. We previously reported that IL-1 prolonged the survival of multinucleated osteoclast-like cells (OCLs) formed in cocultures of murine osteoblasts/stromal cells and bone marrow cells via the prevention of spontaneously occurring apoptosis. It was reported that macrophage colony-stimulating factor (M-CSF/CSF-1) prolongs the survival of OCLs without the help of osteoblasts/stromal cells. The present study was conducted to determine whether IL-1 also directly induces the multinucleation and activation of OCLs. Mononuclear osteoclast-like cells (prefusion osteoclasts; pOCs) were purified using the "disintegrin" echistatin from cocultures of murine osteoblastic cells (MB 1.8 cells) and bone marrow cells. Both IL-1 and M-CSF prolonged the survival and induced the multinucleation of pOCs through their respective receptors. However, actin ring formation (a functional marker of osteoclasts) by multinucleated cells was observed in the pOC cultures treated with IL-1, but not those treated with M-CSF. We previously reported that enriched multinucleated OCLs as well as pOCs placed on bone/dentine slices formed few resorption pits, but their pit-forming activity was greatly increased by the addition of osteoblasts/stromal cells. Here, pit-forming activity of both pOCs and enriched OCLs placed on dentine slices was induced by adding IL-1, even in the absence of osteoblasts/stromal cells. M-CSF failed to induce pit-forming activity in pOC and enriched OCL cultures. These results indicate that IL-1 induces the multinucleation and bone-resorbing activity of osteoclasts even in the absence of osteoblasts/stromal cells.

Animals↗

PubMed1999

Stable association of PYK2 and p130(Cas) in osteoclasts and their co-localization in the sealing zone.

Bone resorption is initiated by osteoclast attachment to the mineralized matrix, cytoskeletal reorganization, cellular polarization, and the formation of the sealing zone. The present study examines the interaction between PYK2 and p130(Cas) (Crk-associated substrate), suggested to be part of the signaling pathway initiated by osteoclast adhesion. Using murine osteoclast-like cells (OCLs) and their mononuclear precursors (pOCs), generated in a co-culture of bone marrow and osteoblastic MB1.8 cells, we show that: 1) p130(Cas) is tyrosine-phosphorylated upon adhesion of pOCs to vitronectin or ligation of beta3 integrins; 2) p130(Cas) colocalizes with PYK2 and the cytoskeletal proteins F-actin, vinculin, and paxillin in the podosomal-rich ring-like structures of OCLs plated on glass and in the sealing zone in actively resorbing OCLs on bone; 3) p130(Cas) and PYK2 form a stable complex in pOCs, independent of tyrosine phosphorylation of either molecule, and this complex is present in Src (-/-) OCLs, in which neither protein is phosphorylated or associated with the osteoclast adhesion structure; 4) the association of p130(Cas) and PYK2 is mediated by the SH3 domain of p130(Cas) and the C-terminal domain of PYK2. These findings suggest that p130(Cas) and its association with PYK2 may play an important role in the adhesion-dependent signaling that leads to cytoskeletal reorganization and formation of the sealing zone during osteoclast activation.

Animals↗

PubMed1999

Effect of interferon therapy on hepatocellular carcinogenesis in patients with chronic hepatitis type C: A long-term observation study of 1,643 patients using statistical bias correction with proportional hazard analysis.

The activity of interferon (IFN) is not elucidated from the viewpoint of cancer prevention in chronic hepatitis C patients en masse. The hepatocellular carcinogenesis rate was analyzed statistically in 1,643 patients with chronic hepatitis C: 1,191 patients with IFN therapy and 452 without IFN therapy. Hepatocellular carcinogenesis rates in the treated and untreated groups were 2.1% and 4.8% at the end of the 5th year, and 7.6% and 12.4% at the 10th year, respectively (P =.0036). Multivariate analysis showed that IFN slightly decreased the risk of carcinogenesis by 33%, compared with that of untreated patients (P =. 14), adjusting for the confounding effects of age, fibrotic stage, gender, and gamma-glutamyl transpeptidase (GGTP) value. Among 1,191 patients with IFN, 461 patients attained persistent loss of hepatitis C virus (HCV) RNA, and the other 145 patients retained normal alanine transaminase (ALT) values without loss of HCV RNA. The hazard of carcinogenesis in these 606 patients with persistent normal ALT with or without HCV-RNA clearance was significantly lower than that of untreated patients (hazard ratio: 0.32; P =.012) and that of the abnormal aminotransferase group. Among patients with chronic hepatitis C, IFN significantly decreased the hepatocellular carcinogenesis rate in those patients with normal or persistent low ALT values.

Adolescent↗

PubMed1999

Association of the human NPPS gene with ossification of the posterior longitudinal ligament of the spine (OPLL).

OPLL (ossification of the posterior longitudinal ligament of the spine) is a common form of human myelopathy with a prevalence of as much as 4% in a variety of ethnic groups. To clarify the genetic factors that predispose to OPLL, we have studied ttw (tiptoe walking), a mouse model that presents ectopic ossification of the spinal ligaments similar to OPLL and have found that the ttw phenotype is caused by the nonsense mutation of the gene encoding nucleotide pyrophosphatase (NPPS), a membrane-bound glycoprotein thought to produce inorganic pyrophosphate, a major inhibitor of calcification and mineralization. To investigate a possible role of NPPS in the etiology of OPLL, we have examined its genetic variations in OPLL patients. A total of 323 OPLL patients was screened by means of polymerase chain reaction/single-strand conformation polymorphism analysis covering all the exons and their surrounding introns, plus about 1.5-kb of the promoter region. We identified ten nucleotide variations in the NPPS gene; five of the alterations caused amino-acid substitutions, and two of them were found specifically in OPLL patients. Subsequently, we performed an association study using these variations and found a significant association of an allele, viz., a deletion of T at a position 11 nucleotides upstream from the splice acceptor site of intron 20 (IVS20-11delT), with OPLL; the proportion of the individuals having this deletion was significantly higher (P = 0.0029) in OPLL patients than in controls, indicating that those who have this variation may be more susceptible to the abnormal ossification of the spinal ligaments. Thus, our study suggests that NPPS plays an important role in the etiology of human OPLL.

Aged↗

PubMed1999

Clinical and virological features of chronic hepatitis C carriers with normal alanine aminotransferase levels despite positive serum HCV-RNA after interferon therapy.

Interferon (IFN) is the only drug that induces viral clearance, but in patients with chronic hepatitis C, HCV-RNA clearance is achieved in only 20%-40% of patients treated with IFN for 6 months. The remaining patients have positive serum HCV-RNA, but about 5%-15% of the patients with positive serum HCV-RNA after IFN therapy showed normal alanine animotransferase (ALT) levels (incomplete response; ICR). In these patients, IFN therapy is thought to be related to the suppression of necroinflammatory reaction in the liver. The aim of this study was to evaluate the demographic, clinical, histological, and virological characteristics of patients with an ICR. In this study, ICR was defined as normalization of serum ALT, but positive HCV-RNA by reverse-transcription (RT) nested PCR at two points, 3 and 6 months after cessation of IFN therapy. By multiple logistic regression analysis, the risk ratio for ICR appearance in patients treated with IFN for more than 12 months was 3.06 compared with patients treated with IFN for less than 12 months. In patients with ICR after IFN therapy, serum ALT was often reelevated during the follow-up period. The incidence of ALT re-elevation was about 10% per year in the patients treated with IFN for less than 12 months, while the incidence of ALT reelevation in the patients treated with IFN for 12 months and more was significantly lower (P = 0.0176) by the log rank test.

Adolescent↗

PubMed1999

Malignant rhabdoid tumor of the colon: report of a case.

A malignant rhabdoid tumor of the colon is very rare and only three cases have been previously described. A 76-year-old man was admitted to the hospital complaining of epigastralgia. An elastic mass was palpable in the right upper abdomen. A barium enema and endoscopic examination showed a giant gyrate tumor arising from the cecum. Abdominal ultrasonography and a computed tomography scan revealed the tumor to be located in the colon associated with multiple liver metastases and gallbladder stones. A right colectomy and cholecystectomy were thus performed. The tumor was histologically composed of sheets of large round and polygonal nuclei with vesicular chromatin, and abundant acidophilic cytoplasm, often containing hyalin-like inclusion. The cytoplasm was positive for vimentin and neuron-specific enolase, and hyaline globules of the rhabdoid tumor cells stained positive for cytokeratin in some cells. Transmission electron microscopy showed characteristic rhabdoid cells with an aggregation of intermediate filaments. A histologic diagnosis of malignant rhabdoid tumor of the colon was made. The tumor demonstrated several unusual findings for malignant rhabdoid tumors including diploidy by a flow cytometric analysis, and positive nuclear immunohistochemical staining for p53 protein and Ki-67 antigen. We report herein the third known case of a pure colonic rhabdoid tumor.

Aged↗

PubMed1999

Genomic organization, mapping, and polymorphisms of the gene encoding human cartilage intermediate layer protein (CILP).

The CILP gene encodes a proform of two polypeptides. One of them, cartilage intermediate layer protein (CILP), is a non-collagenous protein recently isolated from human articular cartilage. The other is homologous to a porcine nucleotide pyrophosphohydrolase (NTPPHase) whose enzymatic activity is highest in articular tissue. The investigation reported here revealed that the CILP gene consists of nine exons spanning approximately 15 kb of genomic DNA on chromosome 15q22. We also report six single nucleotide variations in this gene; five of them cause amino acid changes and the most common of them substitutes isoleucine for threonine at codon 395.

Cartilage, Articular↗

PubMed1999

Methyl alpha-D-mannopyranoside-responsive release of microencapsulated glucoamylase.

Microcapsules are made of porous membranes through which enzymes or proteins can readily permeate. Glucoamylase was encapsulated into microcapsules in the presence of concanavalin A. Microencapsulated glucoamylase was released from the microcapsules into the bulk phase in the presence of methyl alpha-D-mannopyranoside, while it was not released in the absence of methyl alpha-D-mannopyranoside. The initiation and cessation of glucoamylase release from the microcapsules accurately corresponded to the addition and removal of methyl alpha-D-mannopyranoside, respectively. Methyl alpha-D-mannopyranoside served as a controller for the release of glucoamylase.

Journal Article↗

PubMed1999

An unusual case of fatal gas embolism.

We describe an unusual case of fatal gas embolism, in which a man died by connecting an extension tube supplying oxygen to an indwelling catheter that was inserted into the left cephalic vein.

Aged↗

PubMed1999

Clinical outcome of high-dose chemotherapy combined with peripheral blood stem cell transplantation for male germ cell tumors.

Peripheral blood stem cell transplantation (PBSCT) is widely performed currently instead of bone marrow transplantation (BMT) because bone marrow reconstruction is better and the procedure is less invasive. We applied 26 courses of high-dose chemotherapy (1250 mg/m2 of carboplatin, 1500 mg/m2 of etoposide and 7.5 g/m2 of ifosfamide) to 14 male patients with germ cell tumors. Eleven patients underwent high-dose chemotherapy as induction after two to three courses of conventional BEP therapy. The remaining three patients had recurrent disease after conventional chemotherapies. Peripheral blood stem cells were harvested during previous chemotherapy and sufficient CD34+ cells were harvested for transplantation. Although all patients had grade 4 hematotoxicity, the white blood cell count recovered to more than 1000/microl within 8-11 days after PBSCT. No treatment-related death was found. Nine of 14 patients (64.3%) remain disease free at 18 months of median follow up time (range 12-60). We conclude that high-dose chemotherapy is a safe and effective means of treating advanced or refractory germ cell tumors in male patients.

Adult↗