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Biomedical subjects

K Naito

Publications and source records attributed to K Naito.

At least 55 records · Page 3Linked to original sources
PubMed2001

Oral etoposide following combination chemotherapy and radiation therapy in a patient with advanced adult neuroblastoma led to long survival.

Although neuroblastoma is a common tumor of early childhood, it is rare in adults. In spite of the poor prognosis of advanced neuroblastoma in adults, there is still no effective treatment for this condition in adults. Here we report that oral etoposide salvage chemotherapy was able to prolong the survival of an adult patient with advanced neuroblastoma. A 26-year-old man had advanced neuroblastoma that was resistant to combination intravenous chemotherapy and radiation therapy. He was then treated with oral etoposide, at a dose of 50 mg daily for 5 days in a 21-day course. Toxicity was very mild and he was followed as an outpatient while he received 76 courses of this oral etoposide salvage chemotherapy. Seventy months after diagnosis, this patient is still alive and has no new distant metastases.

Administration, Oral↗
PubMed2001

Quantitative analysis of telomerase activity and telomerase reverse transcriptase expression in renal cell carcinoma.

To investigate the relationship between the telomerase activity levels and clinicopathological features of tumors, we quantified the telomerase activities of 23 renal cell carcinomas (RCCs) and four non-cancerous tissues, using a modified telomeric repeat amplification protocol assay, and assessed the hTERT mRNA levels of these samples by reverse transcription-polymerase chain reaction analysis. Elevated levels of telomerase activity had correlation with tumor stages as well as the degree of nuclear grades. Our findings suggested that telomerase activity is a useful indicator for tumor aggressiveness in RCCs. However, hTERT mRNA levels in RCCs had no correlation with nuclear grades and tumor stages. The telomerase activities and the hTERT mRNA levels in cancer cells were not always in parallel. These results suggested that telomerase activity is regulated in a posttranscriptional manner as well as a post-translational manner in tumor cells.

Adult↗
PubMed2001

Comparison of perceptional nasal obstruction with rhinomanometric and acoustic rhinometric assessment.

Perception of nasal stuffiness, together with rhinomanometric and acoustic rhinometric assessments were evaluated before and after nasal and/or sinus surgery in 50 Japanese adult patients. Nasal resistance on both expiration and inspiration correlated well with the patients' perceptions (P<0.05). Nasal volumes (0-4 cm and 0-7 cm) obtained from acoustic rhinometry measurements also correlated well with perception (P<0.05). No significant relationships were found between rhinomanometric and acoustic rhinometric results. Perceptional nasal obstruction, rhinomanometric and acoustic rhinometric results (except for the sectional areas at the I-notch) improved significantly after the operations. Rhinomanometry and acoustic rhinometry are valuable methods for assessing nasal stuffiness, but we must take account of the differences between the two methods.

Adult↗
PubMed2001

Biosynthesis and release of methylarsenic compounds during the growth of freshwater algae.

Arsenic transformations by freshwater algae have been studied under laboratory conditions. By the use of a new analytical method, we identified methylarsenic(III) species in the growth medium of green-alga Closterium aciculare incubated under axenic conditions. The arsenate concentration in the experimental medium began to decrease just after inoculation, and the levels of arsenite and methylarsenicals increased with the growth of C. aciculare. Initially, most of the arsenate was converted into arsenite, which peaked in concentration during the exponential phase. Methylarsenicals accumulated rapidly in the stationary phase. DMAA(V) production was enhanced when the ratio of phosphate to arsenate decreased in the culture medium. The levels of DMAA(V) increased continuously toward the end of the experiment. On the other hand, methylarsenic(III) species remained relatively steady during the stationary phase. Methylarsenic(III) species accounted for 0-35% of methylarsenicals. These results suggest that arsenite and methylarsenicals (containing methylarsenic(III) species) are supplied by phytoplankton, and serve as evidence of the origin of methylarsenic(III) species in natural waters.

Arsenates↗
PubMed2001

Arthroscopic diagnosis of tibiofibular syndesmosis disruption.

PURPOSE: We have been able to diagnose tibiofibular syndesmosis injury by ankle arthroscopy, and in the present study we compare these results with the results from plain radiographs. TYPE OF STUDY: Case series. METHODS: Thirty-eight type-B (Weber system) distal fibular fractures in 38 patients were diagnosed to determine whether tibiofibular syndesmosis disruption was present. According to the Lauge-Hansen system, 16 patients had supination-external rotation fractures and 22 had pronation-abduction fractures. Standard non-weight-bearing anteroposterior radiographs and mortise radiographs were evaluated. Furthermore, ankle arthroscopy was performed on all patients. RESULTS: Tibiofibular syndesmosis disruptions were diagnosed in 16 of the 38 patients (42%) by anteroposterior radiography, 21 of 38 patients (55%) by mortise radiography, and 33 of 38 patients (87%) by ankle arthroscopy. All of the patients who were diagnosed with tibiofibular syndesmosis disruption by anteroposterior radiography and mortise radiography were also confirmed by ankle arthroscopy to have injured their tibiofibular syndesmosis. In 12 patients, ankle arthroscopy was the only method used to diagnose the tibiofibular syndesmosis disruption. CONCLUSIONS: Ankle arthroscopy excels in term of the diagnosis ratio for tibiofibular syndesmosis disruption compared with both anteroposterior and mortise radiography. Therefore, we conclude that ankle arthroscopy is necessary for the correct diagnosis of tibiofibular syndesmosis disruption.

Adolescent↗
PubMed2001

Congenital porto-left renal venous shunt as a cause of galactosaemia.

Congenital porto left renal venous (PRV) shunt was found to be the cause of galactosaemia in four galactosaemic neonates detected by mass screening (Paigen method). The patients did not have hereditary galactosaemias and were diagnosed as having galactosaemia of unknown cause, because porto-systemic venous (PS) shunts had not been recognized. At the time of diagnosis, hypergalactosaemia was not severe (0.44-0.55 mmol/L; 8-10 mg/dl) and plasma concentration of total bile acids (TBA) did not suggest a PS shunt (46-50 micromol/L). However, slightly but consistently increased concentrations of galactose and TBA strongly suggested the presence of a PS shunt, and careful ultrasonographic investigation revealed PRV shunt. We conclude that PRV shunt should be suspected in patients with hypergalactosaemia of unknown cause.

Female↗
PubMed2001

Decreased amount of mpl and reduced expression of glycoprotein IIb/IIIa and glycoprotein Ib on platelets from patients with refractory anemia: analysis by a non-isotopic quantitative ligand binding assay and immunofluorescence.

Using a non-isotopic ligand binding assay and immunofluorescence, we examined the amount of mpl, glycoprotein IIb/IIIa (gpIIb/IIIa) and glycoprotein Ib (gpIb) on platelets from healthy volunteers and patients with refractory anemia (RA). For the analysis of mpl expression, we applied both a non-isotopic ligand binding assay and immunofluorescence using anti-mpl monoclonal antibody, and compared the results from both methods. The non-isotopic ligand binding assay has been developed in our laboratory and is suitable for the quantitative analysis of a small amount of cytokine receptors such as mpl on platelets. In platelets from patients with RA, the amount of mpl expressed by the D value was 0.05+/-0.03 (mean+/-standard deviation), and was significantly lower than that in healthy volunteers (0.15+/-0.05, p<0.0001). The mean fluorescence intensities (MFI) of gpIIb/IIIa and gpIb on platelets from RA patients were 28.8+/-8.8 and 20.8+/-7.7, respectively, and were significantly lower than those on normal subjects (93.2+/-22.6 and 67.4+/-9.1, p<0.0001 and p<0.0001, respectively). There was a good correlation between the amount of mpl and the MFI of gpIIb/IIIa (p=0.794, p<0.0001) or gpIb (p=0.774, p<0.0001), and between those of gpIIb/IIIa and gpIb (p=0.728, p<0.0001). We demonstrated a decreased amount of mpl as well as a reduced expression of gpIIb/IIIa and gpIb on platelets from RA patients.

Adult↗
PubMed2001

Magnetic resonance imaging in hemifacial hyperplasia.

We describe a case of hemifacial hyperplasia due to a combination of lipoma and lipomatosis. The contribution of MRI to the diagnosis of hemifacial hyperplasia and to monitoring growth and development in this condition is demonstrated.

Anatomy, Cross-Sectional↗
PubMed2001

Rat mast cell protease-I enhances immunoglobulin E production by mouse B cells stimulated with interleukin-4.

Mast cell chymase plays important roles in inflammation and tissue remodeling. Here we show that mast cell chymase also functions as an enhancer of immunoglobulin production. In the culture of murine spleen cells stimulated with lipopolysaccharide and interleukin-4, purified rat chymase (rat mast cell protease-I; RMCP-I), at physiological concentrations, enhanced immunoglobulin E (IgE) and IgG1 syntheses but not IgG3 synthesis. The enhancement was also evident when spleen cells depleted of T cells and macrophages were employed as responding cells. Enzymatic activity of RMCP-I was required to enhance IgE and IgG1, because two inhibitors for chymotryptic enzymes, chymostatin and Y-40613, a novel chymase inhibitor, suppressed the enhanced immunoglobulin production, and phenylmethylsulphonyl fluoride, an irreversible inhibitor for serine proteases, totally abolished the enhancing effect. Furthermore, a specific inhibitor for Zn2+-dependent metalloproteases, GI 129471, could also completely inhibit the production of IgE and IgG1 that was enhanced by RMCP-I, suggesting that a metalloprotease also played an essential role in the immunoglobulin production. Our results together with others show that proteases from mast cell granules have important function not only in the efferent phase but also in the afferent phase of immune responses.

Animals↗
PubMed2001

Internal spermatic vein diameter and age at operation reflect the response to varicocelectomy.

It was evaluated whether the diameter of internal spermatic veins (measured directly during operation) correlates with the clinical grade and treatment outcome following varicocelectomy. Fifty-seven consecutive men undergoing left varicocelectomy were included in the study, and spermatic vein diameter was compared with the response to the operation. The diameter appeared larger with increasing clinical grade (subclinical: 3.40 +/- 1.64 mm; grade 1 : 2.74 +/- 0.84 mm; grade 2 : 3.70 +/- 1.09 mm; grade 3 : 4.38 +/- 1.30 mm). In patients 30 years or older, spermatic vein diameter in men whose post-operative semen parameters were unchanged or worsened was statistically larger than that of patients whose post-operative semen parameters were improved, in terms of both sperm concentration (3.90 +/- 1.24 mm versus 2.84 +/- 0.94 mm; P < 0.05) and sperm motility (3.98 +/- 1.24 mm versus 2.67 +/- 0.67 mm, P < 0.01). Although the diameter of internal spermatic veins measured directly during operation correlated well with clinical grade, it is the diameter and patient's age at operation, but not clinical grade, that determine the reversibility of testicular injury following varicocelectomy.

Adult↗
PubMed2001

Possible role for the c-ski gene in the proliferation of myogenic cells in regenerating skeletal muscles of rats.

Skeletal muscle regeneration after injury involves various processes, such as infiltration by inflammatory cells, the proliferation of satellite cells and fusion to myotubes. The c-ski nuclear protein has been implicated in the control of cell proliferation and/or terminal differentiation in the growth of skeletal muscle. However, there have been no reports concerning the involution of c-ski in the regeneration of injured skeletal muscle in mammals. A possible role for c-ski in the proliferation of myogenic cells in rat skeletal muscle during regeneration has been investigated with the assistance of in vitro experiments with L6 skeletal muscle cells. The expression levels of c-ski mRNA in regenerating tissues increased to approximately threefold that of intact tissues at 2 days after injury and decreased to normal levels at 2 weeks after injury. Many mononuclear cells among the Ski-positive cells expressed desmin and proliferating cell nuclear antigen, indicating that Ski-producing cells include the proliferating myogenic cells. The proliferation of L6 cells was significantly retarded by expression of the antisense ski gene. The results of the present study reveal that the c-ski gene plays an important role in the proliferation of myogenic cells in the regeneration of injured skeletal muscle.

Animals↗
PubMed2001

Collecting duct carcinoma with long survival treated by partial nephrectomy.

A case is reported of collecting duct carcinoma of the left kidney treated with partial nephrectomy. A 57-year-old woman presented for evaluation of the left renal mass, which was detected by screening ultrasonography. A computed tomography scan and magnetic resonance imaging showed a solid mass at the upper pole of the left kidney. The renal tumor biopsy revealed a low-grade renal cell carcinoma or a tubulopapillary adenoma. Subsequently, left partial nephrectomy was performed. Microscopically, the tumor showed tubulopapillary proliferation with a fibrous capsule. Histochemically, the tumor cells reacted with lectins or antibodies against the collecting duct. Twenty-four months after partial nephrectomy, the patient is alive and has no distant metastatic lesions. We review the literature on collecting duct carcinoma, in addition to the case of partial nephrectomy.

Biopsy↗
PubMed2001

A case of superficial peroneal nerve injury during ankle arthroscopy.

We report a case of superficial peroneal nerve (SPN) injury caused by ankle arthroscopy. A 20-year-old woman underwent arthroscopy on her right ankle because of chronic ankle pain after a sprain. After arthroscopy, the patient complained of pain on the dorsum of her right foot and felt a radiating pain from the anterolateral portal to the dorsomedial aspect of her foot. Eight months after arthroscopy, we found that a neuroma had developed on the intermediate dorsal cutaneous nerve, and performed neurolysis of the SPN. Her symptoms gradually decreased after surgery, and had disappeared by 45 months. To avoid such an injury of the SPN, the safest placement of the anterolateral portal is necessary and is, according to our previous anatomic study, 2 mm lateral to the peroneus tertius tendon.

Adult↗
PubMed2001

Correlation between eosinophilia induced by CD4(+) T cells and bronchial hyper-responsiveness.

The relationship between CD4(+) T cell-mediated airway eosinophilic inflammation and bronchial hyper-responsiveness (BHR) was investigated. Ovalbumin-reactive T(h)0 clones were adoptively transferred to unprimed BALB/c mice and then the mice were challenged by inhalation of the relevant antigen. Upon antigen provocation, infused T(h) clones infiltrated into the airways, followed by the accumulation and degranulation of eosinophils, goblet cell hyperplasia, edema and increase in bronchial responsiveness to acetylcholine. Transfer of several clones that differed in the levels of IL-5 production revealed that the magnitude of in vivo eosinophilia strongly correlated with the IL-5-producing capacity of the infused T(h) clones. Administration of anti-IL-5 mAb almost completely suppressed antigen-induced eosinophilic inflammation and BHR. Administration of anti-IL-4 mAb or anti-IFN-gamma mAb enhanced the eosinophilia and BHR, whereas anti-IL-2 mAb did not affect them. The number of accumulated eosinophils significantly correlated with the intensity of BHR. Our present results clearly demonstrated that CD4(+) T cells induced BHR as a result of eosinophilic inflammation. IL-5 totally regulated both responses.

Acetylcholine↗
PubMed2001

Effects of recombinant human macrophage colony-stimulating factor on atherosclerotic lesions established in the aorta of high cholesterol-fed rabbits.

Anti-atherosclerotic effects of human macrophage colony-stimulating factor were investigated using rabbits fed a high cholesterol diet. Rabbits fed a diet containing 2% cholesterol for 59 days developed hyperlipidemia and atheromatous aortic plaques. They were then administered 80 microg/kg/day of either macrophage colony-stimulating factor or human serum albumin, as a control, for the next 12 weeks. Compared with the control group, rabbits treated with macrophage colony-stimulating factor had significantly fewer plaques on the inner surface of the thoracic and abdominal aortae, and half the sectional area of thickened intima in the aortic arch, as well as in the thoracic and abdominal aortae. Macrophage colony-stimulating factor also decreased the cholesterol content of the atherosclerotic lesions. Serobiochemical analyses revealed that macrophage colony-stimulating factor increased the levels of high density lipoprotein-cholesterol significantly, without influencing other lipid parameters such as the level of low density lipoproteins. The effects of macrophage colony-stimulating factor were evident until the fourth week of drug injection, at which time anti-human macrophage colony-stimulating factor antibodies were clearly induced in the serum. These results indicate that exogenously administered macrophage colony-stimulating factor suppresses atherosclerotic lesions induced by a high cholesterol diet by activating lipid metabolism in vivo.

Animals↗
PubMed2001

Nitric oxide promotes germ cell necrosis in the delayed phase after experimental testicular torsion of rat.

The purpose of this study is to determine whether inducible nitric oxide synthase (iNOS) is involved in the pathogenesis of testicular ischemia-reperfusion (I/R) injury in association with germ cell death, through either necrosis or apoptosis. Western blot analysis showed that iNOS expression was markedly increased 1 h after ischemia, and was accompanied by a huge nitric oxide (NO) production, as measured by the Griess method, with a peak at 48 h of reperfusion. Immunohistochemistry showed that iNOS was expressed predominantly in the macrophage-like cells infiltrated in the interstitial tissues of the testis. Intraperitoneal injection of aminoguanidine (AMG) (400 mg/day), the inhibitor of iNOS, reduced NO production by 57.7% at 96 h of reperfusion. Calpain activation and proteolysis of alpha-fodrin induced by I/R were inhibited by AMG. Germ cell apoptosis was demonstrated by in situ TUNEL and DNA fragmentation on agarose gel electrophoresis. Germ cell apoptosis was maximally induced at 24 h of reperfusion, and was not inhibited by AMG. NO produced by iNOS in the delayed phase of reperfusion promoted alpha-fodrin proteolysis, which is closely associated with necrosis. Inducible NOS inhibition combined with calpain inhibition may improve impaired spermatogenesis after testicular torsion.

Animals↗
PubMed2001

Computed tomographic evaluation of the position of the leg for mortise radiographs.

We investigated the most advantageous internal rotation angle of the leg for mortise radiographs. One hundred and twenty-eight feet of 64 healthy volunteers with no histories of ankle or foot pathology (72 feet of 36 males, 56 feet of 28 females) were examined. The subjects had an average age of 29 years (range, 19 to 51 years), average height of 167 cm (range, 157 to 181 cm), and average foot length of 25 cm (range, 23 to 27 cm). We obtained a plain axial view at the level of the central patella and 5 mm proximal to the tibial plafond using computed tomography, and investigated the inclination angle of the distal tibiofibular joint to a horizontal plane, regarding it as a mortise angle. The mean mortise angle was 19.1 +/- 5.0 degrees. However, two peaks were observed at around 15 degrees and 20 degrees. This indicated that the mean mortise angle of the males was 21.2 +/- 4.6 degrees, and the mean mortise angle of the females was 16.4 +/- 4.1degrees, with a significant difference between the males and the females' mortise angle (P < 0.0001). There was no correlation between the mortise angle and the height (P = 0.899 in the males, and P = 0.871 in the females), nor between the mortise angle and the foot length (P = 0.359 in the males, and P = 0.512 in the females). Therefore, we concluded that the internal rotation angle of the leg for mortise radiography should be generally set up at about 20 degrees on males and 15 degrees on females.

Adult↗