Biomedical subjects

Y Tokunaga

Publications and source records attributed to Y Tokunaga.

At least 37 records · Page 2Linked to original sources

PubMed2001

Infusion of amino acid enriched solution hastens recovery from neuromuscular block caused by vecuronium.

We investigated the effect of an amino acid infusion on neuromuscular block produced by vecuronium, and on rectal temperature and surface temperature over the adductor pollicis muscle. Sixty adult patients undergoing general anaesthesia were randomly divided into four groups of 15 patients each: amino acid (AA)-post-tetanic count (PTC); AA-train-of-four (TOF); control (C)-PTC; or C-TOF group. In the AA-PTC and AA-TOF groups, after a bolus of vecuronium 0.1 mg kg(-1), a continuous infusion of an 18 amino acid enriched solution (AMIPAREN) was started at a rate of 166 kJ h(-1). In the C-PTC and C-TOF groups, normal saline was administered. Time from vecuronium to the return of the PTC in the AA-PTC group was significantly shorter than in the C-PTC group (mean (SD), 13.3 (4.5) versus 18.0 (5.6) min, P<0.05). Times to return of T1, T2, T3, and T4 (first, second, third, and fourth twitch of TOF) in the AA-TOF group were significantly shorter than in the C-TOF group (21.1 (4.5) versus 28.0 (8.2) min for T1, P<0.05). PTC in the AA-PTC group was significantly greater than in the C-PTC group; 25-35 min after administration of vecuronium (P<0.05). T1/T0 and T4/T1 in the AA-TOF group were significantly higher than in the C-TOF group, 40-120 and 50-120 min after vecuronium respectively (P<0.05). Rectal temperature and surface temperature over the adductor pollicis muscle in the AA-PTC and AA-TOF groups were significantly higher than in the control groups 50-120 and 100-120 min after vecuronium respectively (P<0.05). Infusion of amino acid enriched solution hastens recovery from neuromuscular block.

Adult↗

PubMed2001

Moxibustion treatment of breech presentation.

Breech presentation was successfully corrected by stimulating acupuncture points with moxibustion or low-frequency electrical current. Only patients with breech pregnancies at the 28th week or later were entered into the study. With moxibustion treatment, the control group had a spontaneous correction rate of 165/224 (73.66%), and the treatment group had a correction rate of 123/133 (92.48%) (P<0.0001, x2 test). With low-frequency percutaneous electrical stimulation, the correction rate was 20/941 (83.87%) in the control group and 171/191 (89.52%) in the treatment group (P=0.094, x2 test). The controls in the moxibustion study did no exercises and received no external manipulation to correct breech presentation whereas those in the electrical stimulation study experienced both. Acupuncture stimulation, especially with moxibustion, is expected to serve as a safe and effective modality in the management of breech presentation in a clinical setting.

Acupuncture Points↗

PubMed2001

Computer-assisted neurosurgical navigational system for transsphenoidal surgery--technical note.

Transsphenoidal surgery carries the risk of carotid artery injury even for very experienced neurosurgeons. The computer-assisted neurosurgical (CANS) navigational system was used to obtain more precise guidance, based on the axial and coronal images during the transsphenoidal approach for nine pituitary adenomas. The CANS navigator consists of a three-dimensional digitizer, a computer, and a graphic unit, which utilizes electromagnetic coupling technology to detect the spatial position of a suction tube attached to a magnetic sensor. Preoperatively, the magnetic resonance images are transferred and stored in the computer and the tip of the suction tube is shown on a real-time basis superimposed on the preoperative images. The CANS navigation system correctly displayed the surgical orientation and provided localization in all nine patients. No intraoperative complications were associated with the use of this system. However, outflow of cerebrospinal fluid during tumor removal may affect the accuracy, so the position of the probe when the tumor is removed must be accurately determined. The CANS navigator enables precise localization of the suction tube during the transsphenoidal approach and allows safer and less-invasive surgery.

Acromegaly↗

PubMed2001

Effect of dietary cabbage fermentation extract and young barley leaf powder on immune function of Sprague-Dawley rats.

We investigated dietary effects of cabbage fermentation extract (CFE) and young barley leaf powder (YBLP) on rat immune functions. Male Sprague-Dawley rats of 4 wk age were fed for 3 wk diets containing these samples at 0.1 or 1% level. After the feeding period, serum IgG level was significantly higher in the rats fed 1% CFE. IgG productivity of spleen lymphocytes was enhanced dose-dependently in both groups of CFE and YBLP. Furthermore, IgG productivity of mesenteric lymph node (MLN) lymphocytes was approximately 2 times higher in the rats fed 1% CFE diet than in the control ones. IgA productivity of MLN lymphocytes tended to increase in both of CFE and YBLP groups. From these results, it was suggested that dietary CFE and YBLP reinforced Ig productivity in both systemic and intestinal immune systems. Moreover, CFE feeding tended to enhance the production of TNF-alpha by spleen lymphocytes. In spleen phospholipids, the level of arachidonic acid, a substrate for inflammatory lipid mediators, was not affected by CFE or YBLP feeding.

Animals↗

PubMed2001

[Distribution of 5'-nucleotidase activity in greater omentum of rats].

The aim of the present study is to demonstrate the cellular basis of 5'-nucleotidase (5'-Nase) activity in the greater omentum of rats. Enzyme histochemistry for 5'-Nase showed that lymphatic vessels in the omentum as well as lymphocytes in the milky spots were positively stained. Electron microscopic observation revealed-5'-Nase activity at the luminal surface of the lymphatic endothelial cells, pinocytotic vesicles in the endothelial cells and the surface of fibroblasts located at the intercellular space of adipose cells. Fibroblasts extended long cytoplasmic processes toward adipose cells and inflammatory cells. These findings suggest that lymphatic endothelial cells as well as fibroblasts in the omentum may play an important role in regulation of metabolism and immune mechanisms in the greater omentum by supplying adenosin.

5'-Nucleotidase↗

PubMed2000

Expression of guanylin in "pars tuberalis-specific cells" and gonadotrophs of rat adenohypophysis.

The intestinal peptide guanylin regulates the electrolyte/water transport in the gastrointestinal epithelium by paracrine/luminocrine mechanisms. Because guanylin also circulates in the blood, we investigated the rat hypothalamo-pituitary region for expression and cellular localization of this peptide. Reverse transcriptase-PCR analyses with guanylin-specific primers revealed expression of the peptide in the pars tuberalis and pars distalis of the pituitary. Western blotting analyses in hypophyseal tissue extracts identified the expected 12.5-kDa immunoreactive peptide by using two different region-specific guanylin antisera. Light and electron microscopic immunocytochemistry with the same antisera localized guanylin in "pars tuberalis-specific cells" in the juxtaneural pars tuberalis adjacent to nerve endings and blood vessels of the hypothalamo-pituitary portal system and in gonadotrophic cells within the distal pars tuberalis and ventrolateral part of the pars distalis. The presence and cell-specific localization of guanylin within the hypothalamo-hypophyseal system indicate that this peptide may be specifically involved in paracrine and endocrine regulatory mechanisms.

Animals↗

PubMed2000

Postsurgical sequential methotrexate, fluorouracil, and leucovorin for stages 3 and 4 gastric carcinoma: A preliminary study.

BACKGROUND AND OBJECTIVES: The present study compared the effects of sequential methotrexate and fluorouracil followed by leucovorin rescue (MFL), as an adjuvant chemotherapy vs. UFT (a combination of uracil and tegafur), on patient survival and recurrence following surgery for advanced gastric carcinoma. METHODS: Between July 1990 and June 1998, a total of 54 patients with advanced gastric cancer were treated postoperatively by adjuvant chemotherapy using MFL or UFT. Surgical treatment was performed according to standardized procedures for radical resection of gastric cancer. The patients were stratified into two groups following surgery. The MFL regimen consisted of methotrexate (100 mg/m2) and 5-fluorouracil (600 mg/m2) at hour 3, followed by leucovorin rescue. The oral UFT (375 mg/m2/day), a combination of tegafur and uracil in a molar ratio of 1:4, was continued for 3 years or longer depending on the patients tolerance. RESULTS: In stage 3 gastric cancer, the overall survival rates following surgery was significantly (p < 0.05) higher in the MFL than the UFT group. Difference in disease free survival was not statistically significant between the groups. Recurrence rates showed a trend (p = 0.08) to decrease in the MFL than the UFT group. In stage 4 gastric cancer, no significant difference was obtained in the overall survival rates between the groups. CONCLUSIONS: The present results suggested the superiority of MFL treatment for improving postoperative survival in patients with advanced gastric cancer, in particular for those patients with a high risk of recurrence following potential curative resection. In patients with stage 4 gastric cancer, however, MFL treatment showed similar effects as UFT on the postsurgical survival of the patients.

Aged↗

PubMed2000

Age-related changes of the MR appearance of CNS involvement in neurocutaneous melanosis complex.

We report a case of giant congenital melanocytic nevi (GCMN) at risk of developing neurocutaneous melanosis (NCM) with age-related changes observable on MRI of the brain. However, although the usefulness of MR imaging in NCM is well known, age-related changes on MRI have rarely been reported. The prevalence of positive MRI findings and prognosis in GCMN accompanied by epilepsy and/or mental retardation awaits clarification. This case report may suggest the importance of serial brain MRI in cases of GCMN in assessing the risk of NCM.

Age Factors↗

PubMed2000

C-type natriuretic peptide-like immunoreactivity in the rat inner ear.

C-type natriuretic peptide (CNP) is a member of the atrial natriuretic peptide family (ANP family). The family also includes ANP and brain natriuretic peptide (BNP). These peptides regulate the homeostasis of body fluid and blood pressure as a neuropeptide in the central nervous system as well as a cardiac hormone in the periphery. We have recently reported the expression of CNP mRNA in the inner ear. To assess the possible physiological role of CNP in the inner ear, we investigated the localization of CNP peptide in the rat inner ear by immunohistochemistry at the light and electron microscopic level. CNP-like immunoreactivity was widely distributed in the secretory and the neuronal portion of the inner ear, i.e. the spiral ligament, the dark cell region of the utriculus, the epithelium of the endolymphatic sac, the spiral ganglion cells and the vestibular ganglion cells. The results suggest that CNP may play a role in the homeostasis of the perilymph and endolymph and may also influence nerve activities in the inner ear.

Animals↗

PubMed2000

Diagnostic usefulness of diffusion-weighted magnetic resonance imaging in influenza-associated acute encephalopathy or encephalitis.

A magnetic resonance imaging (MRI) study was performed for a 20-month-old girl with an influenza type A infection who presented acute encephalopathy. Conventional MRI performed 8 days after the onset of encephalopathy, including T1-weighted, T2-weighted, and fluid-attenuated inversion recovery imaging, revealed only vague lesions in the right frontal, temporal, and parietal lobes. In contrast, diffusion-weighted imaging (DWI) then demonstrated the lesions much more intensively. On the 26th day, the lesions previously observed on DWI had become less discernible. The hyperintensity observed on DWI might reflect cytotoxic edema. Thus, DWI may be useful for evaluation of acute influenzal encephalopathy/encephalitis.

Acute Disease↗

PubMed2000

Asymmetric sweating in a child with multiple sclerosis.

A 10-year-old male with multiple sclerosis complained of excessive sweating on the right side of the forehead and shoulder on relapse 3 months after the onset of multiple sclerosis. Because the neurologic evaluation revealed no abnormalities in the sudomotor function, it is likely that the hyperhidrosis resulted from a lesion in the central or preganglionic sympathetic nervous system. Magnetic resonance imaging demonstrated a high-intensity lesion involving the left hypothalamus on T(2)-weighted imaging. Thus hypothalamic involvement might be the reason for the hyperhidrosis in this patient.

Abducens Nerve Diseases↗

PubMed2000

Acute disseminated encephalomyelitis in a female with hereditary neuropathy with susceptibility to pressure palsy.

A 7-year-old female presented with fever, urinary incontinence, mental regression, gait disturbance, and lethargy after diarrhea. Magnetic resonance imaging revealed multifocal T(2)-weighted hypersignal lesions supportive of acute disseminated encephalomyelitis. Her mother had been diagnosed with hereditary neuropathy with susceptibility to pressure palsy. The girl was also determined to have hereditary neuropathy with liability to pressure palsy, with a 1.5-Mb deletion in chromosome 17p11.2 encompassing the gene for peripheral myelin protein 22 detected by fluorescent in situ hybridization. Hereditary peripheral neuropathies may be a factor in triggering the autoimmune demyelinating disorder of the central nervous system.

Charcot-Marie-Tooth Disease↗

PubMed2000

Ontogeny of (D-Ala(2))-deltorphin I-like immunoreactive neurones in foetal rat brain.

Foetal rat brain from embryonic day (ED) 12-22 was immunohistochemically studied to describe the time of first appearance and further distribution patterns of (D-Ala(2))-deltorphin-I-immunoreactive (DADTI-IR) nerve elements. The primary antiserum used in this study was a polyclonal antibody against DADTI previously used in adult and postnatal rat brain mapping. DADTI-IR nerve elements first appeared in the neuroepithelium of ventral mesencephalon on ED 13. From there, positive cell bodies migrated towards the mantle layer until they invaded the whole ventral mesencephalic tegmentum. They then reached their definitive position, corresponding to a subpopulation of the A8, A9 and A10 dopaminergic neurones that had been constantly observed also in the adult age. From ED 15-17, DADTI-positive nerve fibres appeared in the medial forebrain bundle, the neostriatum anlage, the accumbens nucleus, the olfactory tubercle, the fasciculus retroflexus, and the prefrontal cortex. All these locations have also been found in adult rats. From ED 14 onwards, transient DADTI-IR somata and nerve fibres were observed in retinal neuroepithelium, optic pathways as far as the superior colliculus, CA3 hippocampal field, reticular formation in the medulla oblongata. All these locations gradually disappeared either before birth (medulla oblongata) or within the first 3 weeks after birth. These results suggest that the DADT-like molecule recognised by our antibody has during the embryonic development a regulatory function in neuronal growth and differentiation.

Analgesics, Opioid↗

PubMed2000

Reorganization of the primary somatosensory area in epilepsy associated with focal cortical dysplasia.

A 5-year-old boy with focal cortical dysplasia was referred to our hospital because of epileptic seizures. He showed mild weakness of the left hand without sensory disturbance. Brain MRI revealed extensive cortical dysplasia with pachygyria and microgyria around the right central sulcus. On EEG examination, interictal spikes were noted over the right fronto/centro/parietal region. A 37-channel magnetometer revealed that the sources of the spikes were in a small, restricted region of the normal frontal lobe adjacent to the dysplastic brain. Somatosensory evoked magnetic fields indicated that the location of the current source of N2O was in the same area. Our patient shows a unique case of plasticity and reorganization of the somatosensory function due to cortical dysplasia.

Cerebral Cortex↗

PubMed2000

Modified rapid urease test for Helicobacter pylori detection in relation to an immunohistochemical stain.

BACKGROUND: The rapid urease test and touch cytology have been used for the rapid detection of Helicobacter pylori infection. Recently, a modified rapid urease (MRU) test, which provides results in 20 min has been available on a commercial basis. To date, few reports have evaluated the accuracy of this test. This study evaluated the sensitivity, specificity, and accuracy of the MRU test and touch cytology to detect H. pylori in relation to the density of H. pylori infection determined semi-quantitatively by using immunohistochemical stains. METHODS: Biopsy specimens obtained from a total of 60 patients who underwent endoscopy for evaluation of gastroduodenal diseases were studied by using the MRU test, Giemsa stain for touch smear tissue and histological methods. An immunohistochemical stain was used as a standard, and the density of H. pylori infection was graded according to the number of individual bacteria seen as follows: grade 0 = 0; grade 1+ = 1-9; grade 2+ = 10-29; grade 3+ = 30-99; grade 4+ > or = 100. The severity of gastritis was evaluated histologically in each specimen and compared with the density of H. pylori infection. RESULTS: The MRU test had an overall sensitivity of 73%, specificity of 100% and accuracy of 85%. The Giemsa stain had a sensitivity of 91%, specificity of 100% and accuracy of 95%.The sensitivities of the MRU test and Giemsa stain decreased in mild H. pylori infection. In the MRU test, the sensitivity was 47% when the density of H. pylori infection was 1+, while 80-100% sensitivities were obtained when the densities of infection were > or = 2+. With the Giemsa stain, the sensitivity was 80% when the density was 1+, while the sensitivity increased to 100% when the densities were > or = 2+. The severity of gastritis determined by the Rauws scores showed a positive correlation with the density of H. pylori infection as evaluated by immunohistochemical staining. CONCLUSIONS: The MRU test had high sensitivity and specificity for moderate to severe H. pylori infection, but it may result in false-negative results in tests for mild infection. As the MRU test has the advantages of shorter incubation times and low cost, a combination of the MRU test and the Giemsa stain for touch cytology may be the most time- and cost-efficient tests in a clinical setting for the diagnosis of H. pylori infection.

Cytodiagnosis↗

PubMed2000

Case-control study of perinatal factors and hepatoblastoma in children with an extremely low birthweight.

BACKGROUND: There is a significant association between hepatoblastoma and low birthweight. A case-control study was conducted to reveal risk factors for hepatoblastoma in children of extremely low birthweight (< 1,000 g). METHODS: Prenatal and postnatal histories, including parental histories, of 12 hepatoblastoma cases and 75 birthweight-matched controls were compared. RESULTS: The gestational age of the hepatoblastoma cases (23-32 weeks: median 25 weeks), tended to be lower than that of the controls (23-36 weeks; median, 27 weeks; P = 0.072). The time for an infant's bodyweight to return to the same level as the birthweight also tended to be longer in hepatoblastoma cases than in controls (P = 0.055). All hepatoblastoma cases received oxygen therapy for a period of 4-508 days (median 114 days), which was significantly longer than the 0-366 days (median 62 days) in the controls (P = 0.022). Furosemide was given to all hepatoblastoma cases and was used for a significantly longer period in these infants (6460 days; median 89 days) than in the controls (0-241 days; median 44 days P = 0.027). A univariate Cox regression demonstrated that the time taken to regain bodyweight at birth and the duration of both oxygen therapy and furosemide treatment were significantly associated with the development of hepatoblastoma (hazard ratio (HR)= 1.044, P= 0.013; HR = 1.006, P= 0.001; and HR = 1.007, P= 0.001, respectively). Although there were significant correlations between the factors, a multivariate Cox regression analysis identified the duration of oxygen therapy as a significant independent risk factor (HR = 1.006, P = 0.001). CONCLUSIONS: Oxygen therapy and furosemide treatment, along with the rate of growth, are risk factors for the development of hepatoblastoma in children of extremely low birthweight, and the duration of oxygen therapy is the most important factor in predicting the development of hepatoblastoma. Further studies are necessary to determine the real reasons for the development of hepatoblastoma and to protect children of low birthweight from the development of cancer.

Case-Control Studies↗

PubMed2000

Mitogenic activity of gelatin to murine spleen cells.

We reported previously that gelatin stimulates the growth of spleen cells in vitro. Tritium thymidine (3H-TdR) uptake into phytohemagglutinin (PHA)-stimulated spleen cells as well as intact spleen cells was augmented by gelatin. These findings suggest that gelatin serves as a mitogen for lymphoid cells. In this study, the target of action of gelatin was investigated. Tritium thymidine uptake into T cell-rich fraction was enhanced by incubation with 7.5 mg/ml of gelatin for 48 hours. The level of 3H-TdR uptake into B cell-rich fraction was not definitely increased by gelatin. Flow cytometric analysis confirmed these findings. Namely, it showed that treatment of spleen cells with 7.5 mg/ml gelatin increased a ratio of CD3-positive cells and decreased that of CD19-positive cells. Tritium thymidine uptake into natural killer cell-rich fraction was augmented by gelatin in a similar fashion to T cell-rich fraction. Tritium thymidine uptake into macrophages was very low and not affected by gelatin. Tritium thymidine uptake into macrophage-precursors was very low but was enhanced by gelatin. These findings suggest that gelatin could be used as an agent of cancer biotherapy.

Animals↗

PubMed2000

Density of Helicobacter pylori infection evaluated semiquantitatively in gastric cancer.

Helicobacter pylori infection may play a role in the development of gastric cancer; however, a quantitative evaluation of the density of H. pylori infection has not been reported previously in relation to the histologic stage and type of cancer. This study was designed to compare the density of H. pylori infection to the histologic stage and type of gastric cancer. Between March 1996 and March 1998, surgical resection of primary lesion was performed in 50 patients with gastric cancer (39 men and 11 women with a mean age of 67 years) at our institution. Using immunohistochemical stains, the density of H. pylori infection was evaluated semiquantitatively at cancer site as well as noncancerous mucosa adjacent to cancer. This density was compared with the histologic stage and the type of gastric cancer. The severity of the mucosal atrophy was evaluated using the updated Sydney System. The prevalences and density of H. pylori infection decreased in proportion to advances in the cancer stage and the mucosal atrophy. In early cancer of the intestinal- and diffuse-type, the prevalence of H. pylori in adjacent sites was almost 90% and was significantly higher (p < 0.01) than that seen in the advanced cancer lesions. In the intestinal-type early cancer, the prevalence and density of infection was higher (p < 0.05) in the adjacent mucosa than in the cancer site, whereas in the diffuse-type early cancer, H. pylori was found in all cases at the cancer site and the adjacent site. In advanced cancer, the prevalence of H. pylori was about 40% in the adjacent site and about 10% in the cancer site in both histologic types. These figures were significantly lower (p < 0.01) than in the early cancers. The prevalence and density of infection did not differ in the intestinal- and diffuse-type gastric cancers, but did decrease with more advanced cancer stages. The changes in local environment of the advanced cancer may not be conducive to the survival of H. pylori. Thus, the prevalence of H. pylori may be affected by the histologic stage rather than the histologic type of gastric cancer, and the organism may play a similar role, but through different pathways, in the pathogenesis of both types of cancer.

Aged↗