Biomedical subjects

T Tani

Publications and source records attributed to T Tani.

At least 109 records · Page 6Linked to original sources

PubMed1999

Familial hyperparathyroidism: report of a case.

We report herein a case of familial primary hyperparathyroidism diagnosed in a 23-year-old woman who presented with hypercalcemia and urolithiasis. The parathyroid gland was removed, and pathological examination revealed chief cell adenoma. The proband's younger sister had undergone surgery for parathyroid adenoma at the age of 19, and her aunt had a history of urolithiasis with a high level of serum parathyroid hormone. We have not yet found evidence of any other endocrine disorders suggesting multiple endocrine neoplasia (MEN) type 1 in this pedigree.

Adenoma↗

PubMed1999

Complications associated with enteral nutrition using catheter jejunostomy after esophagectomy.

The present study was conducted on 78 patients, encountered over a 7-year period, who had a catheter-feeding jejunostomy placed at the time of thoracoabdominal esophagectomy for esophageal cancer. A broad-based attachment of the jejunal wall to the peritoneum at the place of entry of the catheter was used. Enteral nutrition was begun an average of 10 days after the operation, the caloric content was increased gradually, and the mean duration was 69 days. There were three patients who suffered from local skin erosion at the site of catheter entry, and seven who developed diarrhea and/or a feeling of abdominal fullness, but none of the patients showed any signs of peritonitis or ileus. The morbidity rates related to enteral nutrients and placement of the catheter jejunostomy were 8.9% and 3.8%, respectively. These findings demonstrate that a broad-based attachment of the jejunal wall to the peritoneum at the place of entry of the catheter is useful for preventing leakage or twisting of the jejunum, and for reducing the incidence and severity of the complications of catheter jejunostomy feeding.

Catheterization↗

PubMed1999

A G to A transition at the last nucleotide of exon 6 of the gamma c gene (868G-->A) may result in either a splice or missense mutation in patients with X-linked severe combined immunodeficiency.

We report here that a defect of the interleukin common gamma subunit (gamma c) in X-linked severe combined immunodeficiency (XSCID) previously known as a missense mutation resulted instead in exon skipping in a Japanese XSCID patient. The phenotype of the patient was consistent with that of typical XSCID, and his Epstein-Barr virus-transformed B cells accordingly entirely lacked surface expression of gamma c . On analysis by the reverse transcription-polymerase chain reaction (RT-PCR), a single but small gamma c mRNA species was detected. Exon 6, which encodes the transmembrane domain of gamma c, was skipped in the mRNA. A G to A mutation was found at the last nucleotide of exon 6 of the gamma c gene (868G-->A). The predicted consequence of the exon skipping is a frameshift resulting in a premature stop codon, and the mutated gamma c presumably loses association with the cell membrane. In XSCID, this mutation (868G-->A) is known as a missense mutation that results in R285Q [corrected]. Previously reported patients with the same mutation apparently had no aberrant or alternative splicing but did have the R285Q [corrected] exchange. Similar mutations at the last nucleotide of an outskipped exon have been reported. However, such mutations do not always cause exon skipping. Analyses of RNA structural changes induced by the mutations supported the variability of consequences of the mutations. Taken together, our findings suggest that the 868G-->A mutation of the gamma c gene may affect gamma c transcripts differently, i.e., generating missense or exon skipping, in XSCID patients with the same mutation. Patient-specific variation in splicing thus appears to occur.

Adenine↗

PubMed1999

Biomechanical study of the development of scoliosis, using a thoracolumbar spine model.

A thoracolumbar spine model was made using synthetic resin vertebrae and silicon discs. The model was fixed to a metal frame and spinal deformation caused by loading was determined relative to three-dimensional coordinates set in the frame. A three-dimensional evaluation of the development of spinal deformity was performed by applying rotational, lordotic, and lateral flexional forces in various orders to the model. The most severe scoliosis occurred when loading was done in the order of rotational force, lordotic force, and lateral flexional force.

Biomechanical Phenomena↗

PubMed1999

Abdomino-sacral approach for coloanal anastomosis for lower rectal cancer.

The abdomino-sacral approach is an important and essential procedure for surgery on a recto-anal lesion. The sacral approach had been applied since the former century, but the abdomino-sacral approach was not completely established. The sacral wound dehiscence is a common associated morbidity. It is very difficult for a surgeon who needs this procedure to find a text that contains all the techniques required. Thus, most surgeons have not understood this procedure, and have not known the capabilities of and indications for this approach. The abdomino-sacral approach to lower rectal cancer and/or lesions located there, is described. Especially advantages such as the improved skin incision and the colo-anal anastomosis using this approach are mentioned.

Abdomen↗

PubMed1999

"White coat effect" induced by therapist's presence during speech therapy for stroke rehabilitation: a single case study.

The excessive pressor response triggered in patients by an alerting reaction to a doctor's presence has been termed the "white coat effect." A 68-year-old man with verbal apraxia after multiple lacunar infarctions was referred to the hospital for speech rehabilitation. He experienced difficulty in talking with the speech therapist during therapy sessions but not when talking with his friends or family. Because the therapist's presence was stressful to the patient, it was considered that his anxiety might produce an excessive increase in blood pressure. Blood pressure monitoring was performed during 2 separate days of speech therapies consisting of two sessions each. In one session, therapy was directed by the therapist; in the other, therapy was self-directed. The therapist-directed approach substantially increased both systolic and diastolic blood pressures, whereas the self-directed therapy slightly increased only systolic pressure. It was concluded that the excessive pressor response seen in this patient during therapist-directed speech therapy resulted from the white coat effect induced by the therapist's presence.

Aged↗

PubMed1999

Dynein-ADP as a force-generating intermediate revealed by a rapid reactivation of flagellar axoneme.

Fragmented flagellar axonemes of sand dollar spermatozoa were reactivated by rapid photolysis of caged ATP. After a time lag of 10 ms, axonemes treated with protease started sliding disintegration. Axonemes without protease digestion started nanometer-scale high-frequency oscillation after a similar time lag. Force development in the sliding disintegration was measured with a flexible glass needle and its time course was corresponded well to that of the dynein-ADP intermediate production estimated using kinetic rates previously reported. However, with a high concentration ( approximately 80 microM) of vanadate, which binds to the dynein-ADP intermediate and forms a stable complex of dynein-ADP-vanadate, the time course of force development in sliding disintegration was not affected at all. In the case of high frequency oscillation, the time lag to start the oscillation, the initial amplitude, and the initial frequency were not affected by vanadate, though the oscillation once started was damped more quickly at higher concentrations of vanadate. These results suggest that during the initial turnover of ATP hydrolysis, force generation of dynein is not blocked by vanadate. A vanadate-insensitive dynein-ADP is postulated as a force-generating intermediate.

Adenosine Diphosphate↗

PubMed1999

Affinity profiles of various muscarinic antagonists for cloned human muscarinic acetylcholine receptor (mAChR) subtypes and mAChRs in rat heart and submandibular gland.

A family of five subtypes of muscarinic acetylcholine receptors (mAChR) has been identified based on their molecular structures and second signal transduction pathways. In the present study, we examined the antagonist binding profiles of 9 muscarinic antagonists (atropine, 4-DAMP, pirenzepine, oxybutynin, tiquizium, timepidium, propiverine, darifenacin and zamifenacin) for human muscarinic acetylcholine receptor subtypes (m1, m2, m3, m4 and m5) produced by using a baculovirus infection system in Sf9 insect cells, and rat tissue membrane preparations (heart and submandibular gland). In a scopolamine methyl chloride [N-methyl-3H]- ([3H]NMS) binding assay, pirenzepine and timepidium displayed the highest affinities for the m1 and m2 subtypes, respectively, and both zamifenacin and darifenacin had the highest affinities for the m3 subtype, although the selectivities among the five subtypes were less than 10-fold. Propiverine showed a slightly higher affinity for the m5 subtype, whereas none of the drugs used in this study was uniquely selective for the m4 subtype. The binding affinities of muscarinic antagonists for rat heart and submandibular gland strong correlated with those for human cloned m2 and m3 subtypes, respectively. These data suggest that [3H]NMS binding studies using rat heart and submandibular gland might be useful methods which predict the affinities of test drugs for human muscarinic M2 and M3 receptor subtypes.

Animals↗

PubMed1999

Potential applications of intracardiac echocardiography in the assessment of the aortic valve from the right ventricular outflow tract.

Intracardiac echocardiography (ICE) is a developing technology and a promising method for visualizing intracardiac structures. However, its applications are currently limited to guidance during mitral valvuloplasty, catheter ablation, or electrophysiologic examination. The goal of this study was to observe the aortic valve, measure the annular diameter of the valve by ICE through a right-sided approach, and compare the results by ICE with those by transthoracic echocardiography (TTE) or transesophageal echocardiography (TEE). We studied 18 patients (9 men, 9 women, aged 19 to 72 years) with various heart diseases, including 15 patients with mitral or aortic valvular disease. An imaging catheter was advanced through a long sheath into the outflow tract of the right ventricle. We obtained good longitudinal views of the aortic valve in all patients. Two of the 18 patients had poor image quality by TTE. The annular diameter by ICE correlated more closely with TEE than with TTE. In conclusion, right-sided ICE is a safe, simple, and useful procedure for observing the aortic valve during cardiac catheterization without additional discomfort in the patients. Right-sided ICE is superior to TTE in observing the aortic valve and measuring the annular diameter of the valve. The annular diameter can be measured by ICE as precisely as by TEE.

Adult↗

PubMed1999

A mechanism for shock following stomach rupture in the newborn.

BACKGROUND: Stomach rupture often leads to shock and death within a short period, but the mechanism for this is not well-known. Shock may be due, in part, to endotoxin translocation and endotoxemia. METHODS: Sterile, endotoxin-free HCl (0.1 mol/L), with or without endotoxin-feeding, was injected intraperitoneally into 10-day-old rats, simulating stomach rupture in the newborn. The plasma endotoxin concentration was measured. Plasma glucose and lactate concentrations were monitored to assess physiologic response to endotoxemia and shock. RESULTS: Endotoxin feeding alone caused endotoxemia (0.49 +/- 0.12 ng/mL; P < 0.05) in 10-day-old rats, while plasma endotoxin concentration in controls was less than 0.04 ng/mL. However, the endotoxemia did not cause disruption of glucose regulation or death. Injection of HCl alone did not increase plasma endotoxin concentrations and did not alter glucose regulation. However, HCl injection into endotoxin-fed rats induced endotoxemia (211.1 +/- 70.5 ng/mL; P < 0.05), hypoglycemia, lactacidemia and mortality (45%; P < 0.05). CONCLUSION: Early development of shock following stomach rupture may be in part due to endotoxin translocation and endotoxemia.

Animals↗

PubMed1999

Antitumor effect of cisplatin incorporated into polylactic acid microcapsules.

Cisplatin containing microcapsules (CDDP-MC) were prepared by encapsulating cisplatin suspended in a dispersing agent in a copolymer (lactic acid) matrix using an in water drying method. Cisplatin release from the microcapsules was controlled by the addition of albumin. The CDDP-MC were relatively stable in storage, and there was only minimal initial release of the cisplatin from the microcapsules. The antitumor effects of this sustained release dosage form of cisplatin were evaluated in vitro and in vivo in mice. Mice were given an intraperitoneal (i.p.) injection of CDDP-MC 24 h after inoculation with tumor cells. The CDDP-MC were effective against Ehrlich ascites tumors and showed reduced acute toxicity compared with standard cisplatin solution. Due to the small initial release of the cisplatin from the microcapsules, however, the antitumor effect of the CDDP-MC was weaker than that of cisplatin solution. Conventional sustained release preparations have been reported to have large particle sizes and demonstrate large releases of cisplatin from microcapsules. They have been considered more effective than cisplatin solution because of the large initial release of cisplatin from the microcapsules and the maintenance of drug levels. The antitumor effect of our slow-release formulation of cisplatin was evaluated by administration of CDDP-MC 1, 4, and 7 days before i.p. implantation of tumor cells. The survival time of the tumor-bearing mice was prolonged in the CDDP-MC group, but not in the group treated with cisplatin solution. By using this modified formulation of cisplatin, the toxicity of the drug can be reduced, and effective concentrations of the drug can be maintained locally for prolonged periods of time.

Animals↗

PubMed1999

Bioartificial liver support system using porcine hepatocytes entrapped in a three-dimensional hollow fiber module with collagen gel: An evaluation in the swine acute liver failure model.

The perfusion culture system of hepatocytes entrapped in a three-dimensional hollow fiber module with collagen gel is expected to realize an effective bioartificial liver (BAL) support system. The BAL module contained 5.4 billion porcine hepatocytes, which is approximately 7% of the total liver, supplied adequate metabolic functions, and improved the survival of the experimental acute liver failure swine. Improvement of the prothrombin time by the BAL treatment was not significant; however, the bleeding tendency was suppressed, which resulted in a significantly prolonged survival time of the animals in the BAL treatment group. A drastic up-regulation of the expression of the mRNA for plasminogen activator inhibitor 1 (PAI-1), which is known as an inhibitor for fibrinolysis, may explain the suppression of the bleeding tendency. These results support the efficacy of our BAL system for the treatment of acute liver failure.

Animals↗

PubMed1999

Characterization of the ptr6(+) gene in fission yeast: a possible involvement of a transcriptional coactivator TAF in nucleocytoplasmic transport of mRNA.

Transport of mRNA from the nucleus to the cytoplasm is one of the important steps in gene expression in eukaryotic cells. To elucidate a mechanism of mRNA export, we identified a novel ptr [poly(A)+ RNA transport] mutation, ptr6, which causes accumulation of mRNA in the nucleus and inhibition of growth at the nonpermissive temperature. The ptr6(+) gene was found to encode an essential protein of 393 amino acids, which shares significant homology in amino acid sequence with yTAFII67 of budding yeast Saccharomyces cerevisiae and human hTAFII55, a subunit of the general transcription factor complex TFIID. A Ptr6p-GFP fusion protein is localized in the nucleus, suggesting that Ptr6p functions there. Northern blot analysis using probes for 10 distinct mRNAs showed that the amount of tbp+ mRNA encoding the TATA-binding protein is increased five- to sixfold, whereas amounts of others are rapidly decreased at the nonpermissive temperature in ptr6-1. ptr6 has no defects in nuclear import of an NLS-GFP fusion protein. These results suggest that Ptr6p required for mRNA transport is a Schizosaccharomyces pombe homologue of yTAFII67 and hTAFII55. This is the first report suggesting that a TAF is involved in the nucleocytoplasmic transport of mRNA in addition to the transcription of the protein-coding genes.

Cell Nucleus↗

PubMed1999

Retroperitoneal germ cell tumor treated by PVeBV chemotherapy: a case report.

The extragonadal germ cell tumor are uncommon neoplasms which account for only 1-5% of germ cell tumors, and its prognosis is poor. We report here the use of combination chemotherapy with cisplatin, etoposide, bleomycin, and vinblastine (PVeBV) for the treatment of retroperitoneal germ cell tumor. A 28-year-old male with complaints of abdominal pain and lumbago, without any abnormality in both testes by physical and ultrasonographic examination, showed retroperitoneal tumor by abdominal computed tomography. The serum alpha-fetoprotein and lactate dehydrogenase were elevated. The retroperitoneal tumor was treated surgically. The pathological diagnosis was mixed germ cell tumor. The lung and supraclavicular lymph node metastases disappeared completely after 3 courses of PVeBV chemotherapy with cisplatin (40 mg/m2 per day) and etoposide (100 mg/m2 per day) for 5 consecutive days, with vinblastine (0.2 mg/kg) on day 1, and bleomycin (30 mg/body) given on days 1, 8, and 15. Granulocyte colony-stimulating factor and serotonin receptor antagonist application were available on acute phase toxic effects. The patient is now alive and well, without recurrence, more than 26 months after the operation.

Adult↗

PubMed1999

Cervical spondylotic myelopathy in elderly people: a high incidence of conduction block at C3-4 or C4-5.

OBJECTIVES: To precisely localise the site of conduction block in elderly patients with cervical spondylotic myelopathy in the presence of multilevel compression shown by MRI. METHODS: A total of 44 patients aged 65 and older underwent serial intervertebral recording of spinal somatosensory evoked potentials (SSEPs) from either the intervertebral disc or the ligamentum flavum after epidural stimulation. The site of conduction block identified by abrupt reduction in size of the negative peak was designated as the 0 level with the other levels numbered in order of distance assigning a minus sign caudally. RESULTS: A single site of focal conduction block was disclosed in 42 patients, 23 (55%) at C3-4, 17 (40%) at C4-5, and two (5%) at C5-6. At these levels (0), the amplitude of the negative component was reduced (p<0.0001) to 29% and the area to 22%, with a concomitant increase (p<0.0001) of the initial positive component to 150% in amplitude and 293% in area as compared to the-2 level which was taken as the baseline (100%). CONCLUSIONS: A high incidence (95%) of focal conduction block at C3-4 or C4-5 with normal conduction at C5-6 and C6-7 characterises cervical spondylotic myelopathy in elderly people. Incremental SSEP studies documenting the site of conduction block will help exclude clinically silent cord compression, directing the surgical intervention to the appropriate level of concern.

Aged↗

PubMed1999

Expression and localization of aquaporins in rat gastrointestinal tract.

A family of water-selective channels, aquaporins (AQP), has been demonstrated in various organs and tissues. However, the localization and expression of the AQP family members in the gastrointestinal tract have not been entirely elucidated. This study aimed to demonstrate the expression and distribution of several types of the AQP family and to speculate on their role in water transport in the rat gastrointestinal tract. By RNase protection assay, expression of AQP1-5 and AQP8 was examined in various portions through the gastrointestinal tract. AQP1 and AQP3 mRNAs were diffusely expressed from esophagus to colon, and their expression was relatively intense in the small intestine and colon. In contrast, AQP4 mRNA was selectively expressed in the stomach and small intestine and AQP8 mRNA in the jejunum and colon. Immunohistochemistry and in situ hybridization demonstrated cellular localization of these AQP in these portions. AQP1 was localized on endothelial cells of lymphatic vessels in the submucosa and lamina propria throughout the gastrointestinal tract. AQP3 was detected on the circumferential plasma membranes of stratified squamous epithelial cells in the esophagus and basolateral membranes of cardiac gland epithelia in the lower stomach and of surface columnar epithelia in the colon. However, AQP3 was not apparently detected in the small intestine. AQP4 was present on the basolateral membrane of the parietal cells in the lower stomach and selectively in the basolateral membranes of deep intestinal gland cells in the small intestine. AQP8 mRNA expression was demonstrated in the absorptive columnar epithelial cells of the jejunum and colon by in situ hybridization. These findings may indicate that water crosses the epithelial layer through these water channels, suggesting a possible role of the transcellular route for water intake or outlet in the gastrointestinal tract.

Animals↗

PubMed1999

Chemotactic responses of Dictyostelium discoideum amoebae to a cyclic AMP concentration gradient: evidence to support a spatial mechanism for sensing cyclic AMP.

The motile responses of Dictyostelium discoideum amoebae to a cyclic AMP (cAMP) concentration gradient were examined using a novel assay system. In this system, a cAMP concentration gradient was generated, while the overall cAMP concentration could be either increased or decreased in a chamber containing amoebae. The chemotactic responses of amoebae were examined immediately after they had been subjected to the cAMP concentration gradient. Amoebae moving in random directions in a reference solution ascended a cAMP concentration gradient after they had been exposed to the gradient irrespective of whether there was an increase or a decrease in the overall cAMP concentration. This strongly supports the idea that D. discoideum amoebae can sense a spatial cAMP gradient around them and that this causes their chemoaccumulation behavior. Ascending locomotion became less conspicuous when the amoebae were treated with a homogeneous cAMP solution for approximately 8 min before exposure to a cAMP gradient. This cAMP pretreatment reduced the sensitivity of the amoeba to a cAMP concentration gradient. The cAMP concentration gradient could be reversed in less than 30 s in this assay system, allowing the generation of a cAMP wave by accumulating amoebae to be mimicked. The ascending amoebae continued to move in the same direction for 1-2 min after the gradient had been reversed. This is consistent with the well-known observation that reversal of a cAMP concentration gradient experienced by the amoebae passing through a cAMP wave does not negate their chemotactic movement towards the accumulation center.

Animals↗

PubMed1999

Lipogenic action of the novel oral antidiabetic agent HQL-975 in genetically obese diabetic KK-Ay mice.

HQL-975 (3-{4-12-(5-methyl-2-phenyl-oxazol-4-yl)-ethoxyl-phenyl}-2S- propylamino-propionic acid) is a new oral antidiabetic agent which has been shown to be effective in insulin-resistant diabetic animals. In the present study, we examined the effects of HQL-975 on glucose utilization and insulin action in KK-Ay mice with genetically obese non-insulin diabetes. (1) Dietary administration of HQL-975 (19 mg/kg/d for 7 d) improved hyperglycemia, hyperlipidemia and hyperinsulinemia in the mice. (2) The HQL-975-treated mice showed enhanced net glucose utilization, that is, glucose was significantly incorporated into total lipids in the white adipose tissue (WAT) and liver, and into glycogen in the diaphragm for the last 24 h of the drug administration period. (3) Treatment improved the decreased stimulative action of insulin in the epididymal WAT and the agent increased insulin-stimulated lipogenesis from both glucose and acetate. (4) Treatment also increased the activity of lipogenic enzymes such as glycerol-3-phosphate dehydrogenase and fatty acid synthetase. (5) In vitro exposure of WAT to HQL-975 enhanced lipogenesis in the presence of insulin. From these findings, we conclude that HQL-975 improves glucose utilization of KK-Ay mice through the enhancement of insulin action, which is associated with its lipogenic effects.

Adipose Tissue↗