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Biomedical subjects

Y Takano

Publications and source records attributed to Y Takano.

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

Types of lumbar herniated disc and clinical course.

STUDY DESIGN: A retrospective study of different types of herniated discs and duration of symptoms in patients with lumbar disc herniation, and a trial of longer conservative treatment to reduce the number of operations. OBJECTIVE: To determine whether noncontained and contained herniated discs have different clinical courses and to evaluate the results of the clinical trial of longer and vigorous conservative treatment. SUMMARY OF BACKGROUND DATA: The possibility of a difference in clinical features between contained and noncontained disc herniation has been suggested previously. METHODS: In the first study, the medical history and intraoperative findings of 156 patients who had undergone herniotomy were reviewed. In the second study, conservative treatment of at least 2 months' duration was recommended for all patients with lumbar disc herniation. RESULTS: In the first study, patients with noncontained disc herniation had a shorter preoperative clinical course than those with contained disc herniation. It was rare for noncontained herniation to require surgery 4 months or more after the onset of symptoms. In the second study, the authors' protocol reduced the number of herniotomies required, especially the number of operations for the patients with noncontained disc herniation. CONCLUSIONS: The authors believe that patients with noncontained lumbar disc herniation can be treated without surgery, if these patients can tolerate the symptoms for the first 2 months.

Adolescent↗
PubMed2001

Survivin expression in tumor cell nuclei is predictive of a favorable prognosis in gastric cancer patients.

One hundred and thirty three gastric cancer cases were investigated immunohistochemically to clarify the biological role of survivin in gastric cancer cells using a commercially available anti-survivin antibody (SURV11A). Five gastric cancer cell lines were employed to assess localization of survivin by reverse-transcription-polymerase chain reaction (RT-PCR) Southern blotting, Western blotting and immunofluorescence, signals being found in both nucleus and cytoplasm. Survivin nuclear staining of gastric cancer cells was evident in 109 of 133 cases (82.0%) and associated with a favorable prognosis, being an independent prognosticator on multivariate analysis. Survivin nuclear positivity also correlated with younger age and lower incidence of vessel cancer invasion. In contrast, survivin cytoplasmic positivity was noted in 117 cases (88.0%) and did not correlate with any factor of progression or prognosis. The results indicate that survivin is present in the majority of gastric cancer cells but a nuclear localization may play an important physiological role in hindering tumor progression.

Adult↗
PubMed2001

Microtubule dynamics during infection-related morphogenesis of Colletotrichum lagenarium.

Using a green fluorescent protein (GFP)-tubulin fusion protein, we have investigated the dynamic rearrangement of microtubules during appressorium formation of Colletotrichum lagenarium. Two alpha-tubulin genes of C. lagenarium were isolated, and GFP-alpha-tubulin protein was expressed in this fungus. The strain expressing the fusion protein formed fluorescent filaments that were disrupted by a microtubule-depolymerizing drug, benomyl, demonstrating successful visualization of microtubules. In preincubated conidia, GFP-labeled interphase microtubules, showing random orientation, were observed. At conidial germination, microtubules oriented toward a germination site. At nuclear division, when germ tubes had formed appressoria, mitotic spindles appeared inside conidia followed by disassembly of interphase microtubules. Remarkably, time-lapse views showed that interphase microtubules contact a microtubule-associated center at the cell cortex of conidia that is different from a nuclear spindle pole body (SPB) before their disassembly. Duplicated nuclear SPBs separately moved toward conidium and appressorium accompanied by astral microtubule formation. Benomyl treatment caused movement of both daughter nuclei into 70% of appressoria and affected appressorium morphogenesis. In conidia elongating hyphae without appressoria, microtubules showed polar elongation which is distinct from their random orientation inside appressoria.

Amino Acid Sequence↗
PubMed2001

Effect of transketolase modifications on carbon flow to the purine-nucleotide pathway in Corynebacterium ammoniagenes.

Transketolase, one of the enzymes in the nonoxidative branch of the pentose phosphate pathway, operates to shuttle ribose 5-phosphate and glycolytic intermediates together with transaldolase, and might be involved in the availability of ribose 5-phosphate, a precursor of nucleotide biosynthesis. The tkt and tal genes encoding transketolase and transaldolase, respectively, were cloned from the typical nucleotide- and nucleoside-producing organism Corynebacterium ammoniagenes by a PCR approach using oligonucleotide primers derived from conserved regions of each amino acid sequence from other organisms. Enzymatic and molecular analyses revealed that the two genes were clustered on the genome together with the glucose 6-phosphate dehydrogenase gene (zwf). The effect of transketolase modifications on the production of inosine and 5'-xanthylic acid was investigated in industrial strains of C. ammoniagenes. Multiple copies of plasmid-borne tkt caused about tenfold increases in transketolase activity and resulted in 10-20% decreased yields of products relative to the parents. In contrast, site-specific disruption of tkt enabled both producers to accumulate 10-30% more products concurrently with a complete loss of transketolase activity and the expected phenotype of shikimate auxotrophy. These results indicate that transketolase normally shunts ribose 5-phosphate back into glycolysis in these biosynthetic processes and interception of this shunt allows cells to redirect carbon flux through the oxidative pentose pathway from the intermediate towards the purine-nucleotide pathway.

Amino Acid Sequence↗
PubMed2001

Plasmapheresis in fulminant acute disseminated encephalomyelitis.

We report an 11-year-old girl with acute disseminated encephalomyelitis (ADEM) who developed respiratory failure and coma despite the use of corticosteroid and intravenous immunoglobulin. We performed plasmapheresis four times, which improved her level of consciousness, hyperesthesia, external ophthalmoplegia and muscle weakness, and led to the normalization of brain and spinal cord MRI. Plasmapheresis might be an effective treatment in cases of fulminant ADEM.

Child↗
PubMed2001

Renal artery aneurysm causing hydronephrosis.

A 42-year-old man presented with left hydronephrosis incidentally discovered on abdominal echogram during a routine health examination. Color Doppler ultrasonography, intravenous pyelography and angiography revealed a non-calcified renal artery aneurysm of 30 mm in size compressing the pyeroureteral junction and causing hydronephrosis. Three-dimensional computed tomography (3-D CT) using spiral CT clearly displayed the aneurysm located at the first bifurcation of the left renal artery and involving the anterior segmental artery. Decompression was successfully obtained via in situ revascularization of the renal artery after aneurysmectomy. A literature search revealed 12 cases of renal artery aneurysm causing hydronephrosis reported in Japan, although only three cases were documented in other countries, and these reports are reviewed. Use of 3-D CT for evaluation of renal artery aneurysm is advocated.

Adult↗
PubMed2001

Proper regulation of cyclic AMP-dependent protein kinase is required for growth, conidiation, and appressorium function in the anthracnose fungus Colletotrichum lagenarium.

Colletotrichum lagenarium, the casual agent of anthracnose of cucumber, forms specialized infection structures, called appressoria, during infection. To evaluate the role of cAMP signaling in C. lagenarium, we isolated and functionally characterized the regulatory subunit gene of the cAMP-dependent protein kinase (PKA). The RPK1 gene encoding the PKA regulatory subunit was isolated from C. lagenarium by polymerase chain reaction-based screening. rpk1 mutants, generated by gene replacement, exhibited high PKA activity during vegetative growth, whereas the wild-type strain had basal level activity. The rpk1 mutants showed significant reduction in vegetative growth and conidiation. Furthermore, the rpk1 mutants were nonpathogenic on cucumber plants, whereas they formed lesions when inoculated through wounds. A suppressor mutant showing restored growth and conidiation was isolated from a rpk1 mutant culture. The rpkl-suppressor mutant did not show high PKA activity, unlike the parental rpk1 mutant, suggesting that high PKA activity inhibits normal growth and conidiation. The suppressor mutant, however, was nonpathogenic on cucumber and failed to form lesions, even when inoculated through wounds. The rpk1 and suppressor mutants formed melanized appressoria on the host leaf surface but were unable to generate penetration hyphae. These results suggest that proper regulation of the PKA activity by the RPK1-encoded regulatory subunit is required for growth, conidiation, and appressorium function in C. lagenarium.

Amino Acid Sequence↗
PubMed2001

Interleukin-8 concentrations in conjunctival epithelium brush cytology samples correlate with neutrophil, eosinophil infiltration, and corneal damage.

PURPOSE: To evaluate whether interleukin-8 (IL-8) and RANTES (regulated on activation, normal T-cell expressed and secreted) concentrations in the supernatants of conjunctival epithelial samples from patients with vernal keratoconjunctivitis (VKC) correlate with the number of infiltrating eosinophils or neutrophils and with the severity of corneal lesions. METHODS: Thirty-four patients with VKC, 5 patients with seasonal allergic conjunctivitis, and 10 volunteers without allergic diseases were enrolled in this study. Conjunctival epithelial cells were collected by brush cytology and the number of inflammatory cells was counted. The chemokine expression in the cells was investigated by immunocytochemistry and the chemokine concentrations of the cell suspensions were measured by enzyme-linked immunosorbent assay. RESULTS: The percentages of eosinophils and neutrophils in cell suspensions from VKC patients with corneal erosion or ulcer were higher than those from subjects with clear corneas or superficial punctate keratopathy. IL-8 concentrations in the supernatant of samples correlated significantly with the percentages of neutrophils and eosinophils in paired cell suspensions. No correlation was observed between RANTES and the percentages of eosinophils. Positive staining for IL-8 was observed in the cytosol of conjunctival epithelial cells. CONCLUSION: IL-8 in the extracellular space of the conjunctival epithelium may play a role in the recruitment of neutrophils and possibly eosinophils and in the pathogenesis of corneal damage in severe allergic diseases.

Adolescent↗
PubMed2001

Peroxisomal metabolic function is required for appressorium-mediated plant infection by Colletotrichum lagenarium.

Peroxisomes are organelles that perform a wide range of metabolic functions in eukaryotic cells. However, their role in fungal pathogenesis is poorly understood. Here we report that ClaPEX6, an ortholog of PEX6, is required for the fungus Colletotrichum lagenarium to infect host plants. ClaPEX6 was identified in random insertional mutagenesis experiments aimed at elucidating genes involved in pathogenesis. Functional analysis, using a green fluorescent protein cassette containing the peroxisomal targeting signal1 (PTS1), revealed that import of PTS1-containing proteins is impaired in clapex6 mutants generated by targeted gene disruption. Failure of growth on fatty acids shows an inability of fatty acid beta-oxidation in these mutants. These results indicate that disruption of ClaPEX6 impairs peroxisomal metabolism, even though clapex6 mutants show normal growth and conidiation in nutrient-rich conditions. The clapex6 mutants formed small appressoria with severely reduced melanization that failed to form infectious hyphae. These data indicate that peroxisomes are necessary for appressorium-mediated penetration of host plants. The addition of glucose increased the pathogenicity of clapex6 mutants, suggesting that the glucose metabolic pathway can compensate partially for peroxisomes in phytopathogenicity.

ATPases Associated with Diverse Cellular Activitie↗
PubMed2001

Abnormal myocardial free fatty acid utilization deteriorates with morphological changes in the hypertensive heart.

The left ventricle's morphological adaptation to high blood pressure is classified into 4 patterns based on mass and wall thickness. The geometric changes caused by maladaptation to pressure overload possibly relate to progression of contractile dysfunction with abnormal energy metabolism. The present study assessed whether the geometric adaptation of the left ventricle (LV) to high blood pressure relates to changes in myocardial energy metabolism, especially free fatty acid (FFA) utilization. Thirty-five patients with essential hypertension underwent echocardiography and dual isotopes myocardial scintigraphy using iodine-123 labeled 15-p-iodophenyl-3-(R,S)-methylpentadecanoic acid (BMIPP, an analogue of a FFA) and thallium-201 (Tl-201). Systolic (endocardial fractional shortening; %FS) and diastolic indices (the ratio of early to atrial filling waves; E/A) of LV function were also assessed. Quantitative myocardial BMIPP uptake was evaluated by the BMIPP/TI-201 myocardial uptake ratio (B/T). The subjects were divided into 4 groups based on LV mass and wall thickness: (1) concentric hypertrophy (CH), (2) eccentric hypertrophy (EH), (3) concentric remodeling (CR), and (4) normal geometry (N). The %FS was lower in the EH group than in the other groups. The mitral E/A ratio in the CH group was lowest. B/T was significantly decreased in the EH group compared with the N group (p < 0.05). B/T correlated with the mitral E/A ratio significantly (p < 0.05, r = 0.42), whereas there was no relationship between %FS and B/T. These results indicate that the geometric changes occurring in hypertensive hearts strongly correlate with alternations in cardiac function and with abnormal myocardial FFA metabolism, and that the latter is associated with diastolic abnormality, but not with systolic function.

Aged↗
PubMed2001

Determination of coronary zero flow pressure by analysis of the baseline pressure-flow relationship in humans.

The present study seeks to estimate the difference between coronary zero flow pressure (Pzf) by analysis of the baseline pressure-flow relationship and the Pzf calculated during a long diastole in humans. Although Pzf is likely to provide meaningful information about the characteristics of coronary circulation, there are no available data on Pzf in humans because Pzf is overestimated when it is calculated during normal cardiac cycles. Actual Pzf was determined in 15 subjects by analyzing the coronary pressure-flow relationship during a long cardiac cycle induced by an intracoronary adenosine triphosphate (ATP) infusion, and it was compared with the Pzf calculated during a normal cardiac cycle in order to estimate the difference. Pzf calculated during a normal cardiac cycle was 47 +/- 15 mmHg, which decreased to 36 +/- 9mmHg after intracoronary administration of ATP (0.05 mg) whereas actual Pzf was 21 +/- 7 mmHg. Pzf calculated in a pressure-flow relationship during a normal cardiac cycle under vasodilation correlated well with that during a long diastole (r = 0.75, p < 0.01), although it was 15 +/- 6 mmHg greater than the actual Pzf. It was concluded that Pzf during a normal cardiac cycle could be used to anticipate Pzf.

Adenosine Triphosphate↗
PubMed2001

Effects of HSP-117, a novel tachykinin NK1-receptor antagonist, on cisplatin-induced pica as a new evaluation of delayed emesis in rats.

The effects of a novel tachykinin NK1-receptor antagonist HSP-117 [(2S,3S)-3-[(5-isopropyl-2,3-dihydrobenzofuran-7-yl)methyl]amino-2-phenylpiperidine dihydrochloride] on cisplatin-induced pica, i.e., the eating of nonnutritive substances such as kaolin were examined in rats. HSP-117 inhibited kaolin intake in a dose-dependent manner for 2 days. The 5-HT3-receptor antagonist ondansetron inhibited only on the first day, but not on the second day. These results indicate that the cisplatin-induced kaolin intake on the first day is related to both 5-HT3- and NK1 receptors, while only the NK1 receptor is involved on the second day. Thus, cisplatin-induced continuous pica in rats represents a useful model of not only acute but also delayed emesis.

Animals↗
PubMed2001

Parathyroid hormone-related protein is required for normal intramembranous bone development.

It is well established that parathyroid hormone-related protein (PTHrP) regulates chondrocytic differentiation and endochondral bone formation. Besides its effect on cartilage, PTHrP and its major receptor (type I PTH/PTHrP receptor) have been found in osteoblasts, suggesting an important role of PTHrP during the process of intramembranous bone formation. To clarify this issue, we examined intramembranous ossification in homozygous PTHrP-knockout mice histologically. We also analyzed phenotypic markers of osteoblasts and osteoclasts in vitro and in vivo. A well-organized branching and anastomosing pattern was seen in the wild-type mice. In contrast, marked disorganization of the branching pattern of bone trabeculae and irregularly aligned osteoblasts were recognized in the mandible and in the bone collar of the femur of neonatal homozygous mutant mice. In situ hybridization showed that most of the osteoblasts along the bone surfaces of the wild-type mice and some of the irregularly aligned osteoblastic cells in the homozygous mice expressed osteocalcin. Alkaline phosphatase (ALP) activity and expression of osteopontin messenger RNA (mRNA) in primary osteoblastic cells did not show significant differences between cultures derived from the mixture of heterozygous mutant and wild-type mice (+/? mice) and those from homozygous mutant mice. However, both mRNA and protein levels of osteocalcin in the osteoblastic cells of homozygous mutant mice were lower than those of +/? mice, and exogenous PTHrP treatment corrected this suppression. Immunohistochemical localization of characteristic markers of osteoclasts and ruffled border formation did not differ between genotypes. Cocultures of calvarial osteoblastic cells and spleen cells of homozygous mutant mice generated an equivalent number of tartrate-resistant acid phosphatase-positive (TRAP+) mononuclear and multinucleated cells and of pit formation to that of +/? mice, suggesting that osteoclast differentiation is not impaired in the homozygous mutant mice. These results suggest that PTHrP is required not only for the regulation of cartilage formation but also for the normal intramembranous bone development.

Adenosine Triphosphatases↗
PubMed2001

Increases of calcium and magnesium and decreases of phosphorus and iron with aging in human uterine tubes.

To elucidate compositional changes of the uterine tube by aging, the authors studied age-related changes of elements in human uterine tubes by inductively coupled plasma-atomic emission spectrometry. The uterine tubes were resected postmortem or surgically removed from patients with uterine myoma. It was found that the contents of calcium and magnesium increased progressively with aging in uterine tubes, whereas the contents of phosphorus and iron decreased gradually with aging. The sulfur content of uterine tubes remained constant and independent of aging. Regarding relationships between elements, significant relationships were found between calcium and magnesium contents, between phosphorus and iron contents, between phosphorus and sulfur contents, and between phosphorus and sodium contents in human uterine tubes.

Aged↗
PubMed2001

Age-related changes of bone mineral density in human calcaneus, talus, and scaphoid bone.

To examine whether the bone mineral density (BMD) decreases uniformly with aging in any spongy bones, the authors investigated age-related changes of BMD in the calcaneus, talus, and scaphoid bone. After the ordinary dissection by medical students was finished, calcanei, tali, and scaphoid bones were resected from the subjects, and BMDs were measured by dual-energy X-ray absorptiometry. Their BMDs seemed to decrease gradually with aging in the calcanei, tali, and scaphoid bones. It was found that there were statistically significant relationships between age and BMD in the men's and women's scaphoid bones, women's tali, and women's calcanei, but not in the men's tali and calcanei. It should be noted that there were significant relationships between age and BMD in both men's and women's scaphoid bones. In regard to relationship in BMD between the bones of the upper and lower limbs in individuals, it was found that the relationship between the calcaneus and talus was higher than that between the calcaneus and scaphoid bone. This suggests that there is a higher relationship in BMD between the two tarsal bones compared with that between the tarsal and carpal bones.

Aged↗
PubMed2001

Phosphatase activities of rat intestinal enterocytes and their relation to diverse luminal pH, with special references to the possible localization of phytase along the brush border membrane.

Phosphatase activities associated with the intestinal brush border membrane (BBM) of the rat were examined histochemically in relation to the characteristic environment of the intestine, where luminal pH fluctuates drastically between alkaline and acid pH ranges. Special attention was given to intestinal alkaline phosphatase (IALP) and phytase on the BBM. Whole body fresh-frozen sections of young rats and their rapidly frozen and freeze-substituted small intestines, embedded in Technovit 7100, were processed for the histochemical demonstration of phosphatase activity at three different pH values (9.2, 7.3, and 5.2), representing the deviation of luminal pH in vivo. Either an azo-dye method or lead-salt method was employed using naphthol AS-MX phosphate and ATP as substrate, respectively. With the azo-dye method, intense phosphatase reactions were demonstrated along the BBM at all three pH ranges. Phosphatase reactions of the BBM at pH 9.2 and 7.3 were abolished by L(+)-phenylalanine, heat pre-treatment, and EDTA chelation although some reaction remained at pH 7.3 after the treatment with EDTA or L(+)-phenylalanine. Phosphatase reactions of the BBM at pH 5.2 were resistant to L(+)-phenylalanine, L(+)-tartrate, PCMB and EDTA chelation, implying that the characteristics of the enzyme responsible for phosphohydrolysis at acid pH values differed from those at higher pH values. The lead-salt method in which ATP was used as substrate revealed intense reactions--which were dependent on Mg++ and stimulated by Ca++ and resistant to L(+)phenylalanine--to be localized along the BBM at alkaline and neutral pH values, but not at acid pH values. In vitro experiments showed progressive hydrolysis of naphthol AS-MX phosphate by purified phytase at pH 5.2, in a dose-dependent manner, and suggested the possible involvement of phytase in the phosphatase reactions of the BBM at acid pH. These data indicate that the phosphatase reactions at alkaline and neutral pH values, associated with the BBM of the rat intestine, represent IALP and Mg++/ Ca++-ATPase, while those at acid pH appear to correspond to phytase activity, something which has not been demonstrated by histochemical methods despite the availability of extensive data based on biochemical analyses.

6-Phytase↗
PubMed2001

[A case of metachronous multiple primary lung cancers coexistent with atypical adenomatous hyperplasia].

A seventy-year-old woman was admitted for an abnormal chest shadow on a routine radiograph. She had undergone left upper lobectomy with mediastinal lymph node resection (R2a) for lung cancer (stage I), eight years before. We diagnosed this cancer as well differentiated papillary adenocarcinoma, and it coexisted with a focus of atypical adenomatous hyperplasia (AAH) in the resected material. We had been following up this patient with chest radiography, CT scanning, and tumor marker tests, but eight years after her first operation, we found a small nodular lesion in the left upper field (S6). This nodule was not diagnosed with fiberoptic bronchoscopy. Because we could not exclude primary lung cancer or intrapulmonary metastasis (eight years ago), we performed partial lung resection on the left S6 nodule. Histopathologically, the diagnosis was well differentiated papillary adenocarcinoma of the lung, coexisting with a small hyperplastic focus in the resected material. It was very difficult to diagnose whether these two cancers were metachronous multiple primary lung cancers, or one primary and its intrapulmonary metastasis. In a retrospective study, an immunohistochemical examination employing Ki-67, PCNA, p 27 and p 53 was performed in order to differentiate between metachronous multiple primary lung cancer and intrapulmonary metastasis. But we found AAH in the same resected lung eight years ago, and suggested the possibility that another small, atypical focus had developed into a malignancy. We report a case of metachronous multiple primary lung cancers and review the relevant literature.

Adenocarcinoma↗