Biomedical subjects

T Deguchi

Publications and source records attributed to T Deguchi.

At least 181 records · Page 10Linked to original sources

PubMed1994

Differentiation of cholinergic neurons and physiological role of ciliary neurotrophic factor (CNTF).

Seven types of mRNA that differed in the 5'-non-coding region were identified for choline acetyltransferase of mouse spinal cord. These mRNAs were produced by differential splicing of pre-mRNAs transcribed from three different promoter regions. Two murine cholinergic cell lines, NS20Y and NG108-15, expressed M-type mRNA most abundantly. Using these cell lines, promotor activity in choline acetyltransferase gene was analyzed by transient assay of a reporter gene. The result indicated that there was promoter activity in the region upstream of the M-type exon and enhancer activity in the intron downstream of the M-type exon, and that this region regulated neuron-specific expression of choline acetyltransferase activity. In contrast, R-type mRNA was exclusively expressed in cultured superior cervical ganglion cells and was markedly increased by ciliary neurotrophic factor (CNTF). To analyse the physiological role of CNTF, we constructed and screened a cDNA library from human sciatic nerves and isolated two types of cDNAs for human CNTF. Sequence analysis revealed that one type of cDNA corresponded to the normal mRNA, while the other type contained a 4 bp stretch insertion within the coding region, which caused frameshift from 39th amino acid with a stop codon 24 amino acids downstream. Analysis of genomic DNA for CNTF showed that there was a point mutation from G to A in the intron of the mutated allele, which created a new splice acceptor site and generated a new mRNA species with 4 bp insertion.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗

PubMed1994

Statistics of differential Lissajous EMG for normal occlusion and Class II malocclusion.

Differential Lissajous electromyography (DL-EMG), a method of representing the simultaneous EMG values of two paired muscles as a single, continuous figure, was used in chewing tests with a sample of Japanese women having normal occlusion compared with a like group of Japanese female adolescents, having Class II, Division 1 malocclusion. For the normal sample, the DL-EMG figures described by the coordinated activity of the bilateral temporal and masseter muscles during chewing gum mastication typically appeared as repetitions of loops. Statistical data were gathered on the total EMG voltages, and on the location, rotational direction, and orientations of the DL-EMG loops when graphed onto Cartesian coordinates. These data were compared with those taken from the Class II sample. Significant differences were observed in the latter group for the EMG voltage levels of the balancing-side masseter muscles. The DL-EMG figures of the Class II group also showed irregularities in the shapes, locations, rotational directions, and orientations of the loops, indicative of irregular masticatory patterns. These data suggest that with sufficient control of factors such as age and sex, electromyography and especially DL-EMG techniques can be useful for characterizing masticatory differences between various occlusal groups.

Adolescent↗

PubMed1994

A null mutation in the human CNTF gene is not causally related to neurological diseases.

We report a null mutation in the human ciliary neurotrophic factor gene (CNTF). The mutated allele shows a G to A transition producing a new splice acceptor site and the resulting mRNA species codes for an aberrant protein. Analysis of tissue samples and transfection of CNTF minigenes into cultured cells demonstrates that the mutated allele expresses only the mutated mRNA species. In 391 Japanese people tested, 61.9% were normal homozygotes, 35.8% heterozygotes and 2.3% mutant homozygotes. The distribution of the three genotypes is similar in healthy and neurological disease subjects, indicating that human CNTF deficiency is not causally related to neurological diseases.

Alleles↗

PubMed1994

Calcium-independent release of acetylcholine from stable cell lines expressing mouse choline acetyltransferase cDNA.

Stably transfected cells expressing mouse choline acetyltransferase (ChAT) cDNA were established, and the synthesis and release of acetylcholine (ACh) were examined. A cDNA clone coding for mouse ChAT was inserted into an expression vector (pEF321) containing a promoter for human elongation factor 1 alpha to construct pEFmChAT. Neuronal (NG108-15, NS20Y, N1E115, and Neuro2A) and nonneuronal cell lines (L cells and NIH3T3) were transfected with pEFmChAT, and the cell lines that stably expressed high ChAT activity were selected. These cells expressed the 66-kDa ChAT protein and accumulated ACh mostly in the cytosol. The concentration of intracellular ACh in the cells increased upon raising the choline level in the medium. The cells continuously released ACh in a Ca(2+)-independent fashion. Neither high K+ nor calcium ionophore stimulated release of ACh from the cells.

3T3 Cells↗

PubMed1994

Relationship between sagittal condylar path and the degree of mandibular asymmetry in unilateral cross-bite patients.

This study was conducted to investigate the relationship between sagittal condylar path and the degree of mandibular asymmetry during jaw opening movement in subjects (25 adults: 7 males, 18 females) with unilateral cross-bite. The degree of mandibular shift was measured with the axial projected head plate. Sagittal condylar path was obtained by CADIAX. The shifted side of the condyles had a steeper condylar path than that observed on the ipsilateral side. There was no correlation between the deviation of the forward component in the sagittal condylar path and the degree of mandibular asymmetry.

Adolescent↗

PubMed1994

Relationship between mean arterial pressure and muscle cell pH during forearm ischaemia after sustained handgrip.

Recent evidence suggests that there is a close correlation between the physiological responses to muscle chemoreflex and the decrease in intracellular pH during ischaemia after handgrip. This study evaluated whether the relationship is linear or has an apparent threshold. We measured muscle cellular pH through phosphorous nuclear magnetic resonance spectroscopy (31P-NMR), mean arterial blood pressure (MAP) and heart rate (HR) during ischaemia after sustained handgrip exercise at 50% of maximum voluntary contraction (MVC). Contraction was sustained for 15, 30, 45 and 60 s, followed by 2 min of circulatory arrest, respectively. Muscular pH during the ischaemia decreased linearly with increasing contraction time, from the base-line level of 7.11 +/- 0.03 units (U) to 6.98 +/- 0.03, 6.90 +/- 0.04, 6.72 +/- 0.06 and 6.54 +/- 0.06 U after 15-, 30, 45-, and 60-s contractions, respectively. The MAP was 86 +/- 2 mmHg at rest and did not change during the ischaemia after 15- and 30-s contractions. However, it significantly increased to 95 +/- 2 and 107 +/- 2 mmHg, after 45- and 60-s contractions, respectively. These data indicate that the relationship between MAP and pH is not a single linear relationship, showing one breaking point around the pH of 6.90 units. It suggests that the muscle chemoreflex has a clear threshold around 6.90 units of muscle pH, and below this pH, MAP increased linearly with decreasing muscle cellular pH.

Adolescent↗

PubMed1994

[Detection of Mycoplasma genitalium from male patients with non-gonococcal urethritis by polymerase chain reaction].

Mycoplasma genitalium causes urethritis in non-human primates, but studies on its pathogenicity in man have been hampered by the difficulty in isolating this oragnism in culture. We have used a specific polymerase chain reaction to examine the role of M. genitalium in non-gonococcal urethritis (NGU). Oligonucleotide primers were used to amplify a 281 bp of 140-KDa adhesin gene of M. genitalium. A characteristic PCR product was amplified, when M. genitalium DNA was template for the PCR. No amplified product was detected in Mycoplasma pneumoniae DNA, Mycoplasma hominis DNA or other bacterial DNAs. M. genitalium DNA was detected in urethral swabs from 17 (14.9%) of 114 men with NGU. Three (9.1%) of the 33 men with Chlamydia-positive NGU and 14 (17.3%) of the 81 with Chlamydia-negative NGU were positive for M. genitalium DNA, but 29 men without urethritis were negative. The prevalence of M. genitalium in NGU and in Chlamydia-negative NGU was significantly higher than that in the normal control. These findings suggest that M. genitalium would be a cause of NGU.

Chlamydia Infections↗

PubMed1994

[A study on predicting factors of the effect of intra-arterial infusion chemotherapy in patients with bladder cancers: the usefulness of in-vitro chemisensitivity test measuring intracellular ATP contents (ATP assay)].

We studied a relationship between in vitro sensitivity of the tumors to anti-cancerous drugs and histopathological effectiveness of an intra-arterial infusion chemotherapy in 15 patients with bladder cancers. The in vitro sensitivity test was performed by measuring intra-cellular ATP contents (ATP assay). The intra-arterial chemotherapy were performed by injecting methotrexate (MTX), adriamycin (ADM) and eisplatin (CDDP) from the internal iliac artery. When the intra-cellular ATP contents of the tumor cells treated with an anti-cancerous drug decreased to less than 50% of the untreated tumor cells, the tumor was evaluated as sensitive to the drug. The effectiveness of the chemotherapy were histopathologically evaluated by a pathologist according to the response criteria for bladder cancer treatment. When the histopathological responses of higher than grade 2 were observed in the tumor, the chemotherapy was evaluated as effective. In 8 of 9 tumors sensitive to ADM, chemotherapy were effective histopathologically and in all 6 tumors resistant to ADM, histopathological response of the chemotherapies were poor. The overall coincidence ratio between sensitivity to ADM and the histopathological effectiveness of the chemotherapy was 93%, showing statistically significant correlation. In 7 of 12 tumors sensitive to CDDP, the chemotherapies were effective and in 2 of 3 tumors resistant to CDDP, the chemotherapies were ineffective. Although the overall coincidence ratio between the sensitivities to CDDP and chemotherapeutic effectiveness was 60%, there was no significant correlation between them. In 7 of 8 tumors sensitive to both of ADM and CDDP, the chemotherapies were effective and in 6 of 7 tumors resistant to at least one of them, the chemotherapies were ineffective. (ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗

PubMed1994

[Clinical study of neoadjuvant intraarterial chemotherapy (I A-MAC) for advanced bladder cancer].

The clinical efficacy of intraarterial neoadjuvant chemotherapy with MTX, ADR and CDDP in 88 patients with advanced bladder cancer (> or = T2 or TCC G3) was evaluated. The intraarterial chemotherapy was performed using Seldinger's method. The three drugs were administered at the same time among 60 patients. In sixteen patients MTX was administered intravenously before intraarterial infusion of ADR and CDDP. In twelve patients, a high dose of CDDP (more than 100 mg/m2) was administered. The mean regression rate was 70%. That of the high-dose CDDP group was rather superior to the other two groups. However, the adverse reaction and duration of recovery were inferior to those of the other two groups. When intraarterial chemotherapy is performed as a neoadjuvant chemotherapy, care must be taken to determine the suitable dose.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1994

[Infection in genitourinary cancer patients during cancer chemotherapy].

To examine the frequency and the type of infection during cancer chemotherapy in the urological field, we studied the causes of fever in 67 patients with genitourinary cancer. Twenty-six patients had developed a fever of higher than 38 degrees C. Although fever without proven infection was seen in 11 patients (42.3%), fever caused by pyelonephritis was the most common infection. There was a relationship between fever and the presence of hydronephrosis. Fever was observed more often in patients with a leucocyte count of less than 2,000 white blood cell/mm3. In conclusion, we recommend the interruption of cancer chemotherapy or the use of granulocyte colony-stimulating factor for the prevention of infection, when the leukocyte count is less than 2,000 cell/mm3, especially in patients with hydronephrosis.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1993

Detection of micrometastatic prostate cancer cells in lymph nodes by reverse transcriptase-polymerase chain reaction.

We have developed a highly sensitive method for detecting prostate cancer cells using reverse transcriptase-polymerase chain reaction (RT-PCR) with primers specific for prostate-specific antigen gene. Forty-four lymph nodes obtained from 22 patients with prostate cancers were analyzed by RT-PCR to detect metastatic prostate cancer cells. RT-PCR could detect prostate-specific antigen mRNA in five lymph nodes with histologically and/or immunohistochemically identifiable metastases and in four lymph nodes with negative histological and immunohistochemical analyses for metastases. RT-PCR was a more sensitive method than histology and immunohistochemistry in detecting metastatic prostate cancer cells and could be applied for diagnosing micrometastases of prostate cancer to lymph nodes. This highly sensitive RT-PCR will be a relevant tool to allow a more accurate clinical assessment of lymph node metastases of prostate cancer and to understand lymphatic dissemination of prostate cancer biologically.

Base Sequence↗

PubMed1993

The structure and characteristics of a fourth allele of polymorphic N-acetyltransferase gene found in the Japanese population.

Polymorphic N-acetyltransferase (NAT2), which exists in the human liver and metabolizes a wide spectrum of arylamine, is encoded by one gene (NAT2). We have identified the mutations of a fourth NAT2 allele (allele 4) which we previously found in the Japanese population. Compared with allele 1, which expresses a high enzyme activity, allele 4 has 3 nucleotide differences. 2 are missense mutations at nucleotide position (nt) 341 and 803. The other is a silent mutation at the KpnI site. From the result of expression studies of chimeric gene constructs between allele 1 and allele 4 in Chinese hamster ovary cells, nt 341 missense mutation of the allele 4 which causes the Ile-114 to Thr change is responsible for the low enzyme activity of NAT2 protein.

Alleles↗

PubMed1993

An improved method for genotyping of N-acetyltransferase polymorphism by polymerase chain reaction.

Polymorphic N-acetyltransferase in human liver catalyzes N-acetylation of various arylamine-containing drugs and environmental chemicals. To accelerate the pharmacogenetic and ecogenetic studies of N-acetyltransferase polymorphism, we have developed a rapid and simple method for genotyping using a polymerase chain reaction based restriction fragment length polymorphism. This method distinguishes four kinds of allele of the N-acetyltransferase gene using a single polymerase chain reaction starting with a set of primers, followed by successive Asp718, BamHI and TaqI digestions, and then running the samples on a single electrophoresis lane. This method allows us to determine ten different genotypes easily and reliably.

Alleles↗

PubMed1993

Multiple mRNA species of choline acetyltransferase from rat spinal cord.

A cDNA library directed by a specific primer was constructed from the rat spinal cord and screened with 32P-labeled rat choline acetyltransferase cDNA which was recently isolated in this laboratory. Sequence analysis of 29 clones indicated that there are four types of cDNA (R1-, R2-, N1- and M-types). The nucleotide sequences in these cDNAs were identical in the coding region and the first 38 bp of the 5'-noncoding region, but differed in the 5'-noncoding region upstream of -38 bp. The R1-type was identical to the cDNA previously cloned from the rat spinal cord. The M and N1-type cDNAs both had sequences homologous to that of the cDNA previously obtained from the mouse spinal cord. Polymerase chain reaction analysis confirmed the presence of these 4 types of mRNA and found another type (N2-type) of transcript. The numbers of cDNA clones isolated and the relative amounts of polymerase chain reaction products for each type of mRNA suggested that the most abundant transcript was M-type. Sequencing of the genomic clone containing the 5'-region of choline acetyltransferase mRNA revealed that these five types of mRNA species were transcribed from three different promoter regions and produced by differential splicing of the 5'-noncoding exons.

Amino Acid Sequence↗

PubMed1993

Case report: three typical cases of glossectomy.

Glossectomy, or tongue reduction, is not commonly performed in Japan even though the proportion of patients with Class III skeletal pattern is higher among Japanese people than among Caucasians. The case reports on the ensuing pages follow three patients--one adult with bimaxillary dentoalveolar protrusion, another adult with Class III malocclusion, and a 10-year-old with Class III malocclusion and posterior crossbite--through treatment which included tongue reduction.

Adult↗

PubMed1993

Transcriptional regulation of choline acetyltransferase gene by cyclic AMP.

The effect of cyclic AMP on the gene expression of choline acetyltransferase (ChAT) was studied in NG108-15, mouse neuroblastoma and rat glioma hybrid cell lines. Addition of dibutyryl cyclic AMP to the culture medium increased both the ChAT mRNA level and ChAT activity twofold. Polymerase chain reaction analysis of the ChAT mRNA indicated that, among the multiple mRNA species, M-type mRNA was transcribed most efficiently, with or without the addition of dibutyryl cyclic AMP. The 5' region of the mouse ChAT gene was ligated to the bacterial chloramphenicol acetyltransferase gene, and the expression of chloramphenicol acetyltransferase activity was determined by transfection analysis. Cyclic AMP derivatives enhanced the reporter gene expression in both transiently and stably transfected cells. DNA deletion analysis indicated that the intron region downstream of the M-type exon is necessary for the cyclic AMP responsiveness, and that cyclic AMP derivatives increase ChAT gene transcription mainly from M-type promoter. These results suggest that a cis-acting DNA element that confers the cyclic AMP responsiveness of the ChAT gene is present in the intron downstream of the M-type exon.

Animals↗

PubMed1993

Cementum-like tissue deposition on the resorbed pulp chamber wall of human deciduous teeth prior to shedding.

In the later stage of exfoliation in human deciduous teeth, odontoclastic resorption takes place at the pulpal surface of the coronal dentin. However, this resorption does not continue until the teeth are shed, and the resorbed pulp chamber wall is usually repaired by cementum-like tissue deposition. In this study, we examined the formation and characteristics of the cementum-like hard tissue on the resorbed dentin surface in the pulp chamber of deciduous teeth prior to shedding. The site and degree of deposition of newly formed cementum-like tissue on the resorbed pulp chamber wall varied from tooth to tooth. Furthermore, they also showed compositional and structural variations. Generally, however, the matrix of the cementum-like tissue was composed of intrinsic collagen fibers, acellular or cellular. There was a tendency for acellular cementum-like tissue to be deposited on small and shallow resorption bays, whereas the cellular type was found on larger and deeper ones. In both cases, the surface of the deposited cementum-like tissue on the resorbed dentin surface usually became flat. However, unlike the cementum repair of resorbed areas on the root surface, no acellular extrinsic fiber cementum-like tissue was found on the resorption pulp chamber wall. Although the role of the repair of the resorbed pulp chamber wall with cementum-like tissue deposition just before shedding is unknown, it might play some role in the retention of deciduous teeth until shedding.

Dental Pulp↗

PubMed1993

A histological study of the exfoliation of human deciduous teeth.

For clarification of the histological details of the shedding of human deciduous teeth, exfoliated and extracted deciduous teeth were examined by light and electron microscopy. After the roots were completely resorbed, the dentogingival junction migrated along the inner resorbing surface and finally reached the pulpal surface of the crown. At the same time, the gingival epithelium also proliferated and migrated under the crown of the deciduous tooth in such a way that part of it lined the residue of the pulp and another part lined the surface overlying the erupting successional tooth. This phenomenon took place from various sides of the tooth surface. Therefore, just before exfoliation, the migrated gingival epithelium formed narrow necks of tissue, and the crown was only superficially attached to the gingiva by them. The final shedding of the tooth appeared to occur by a tearing of these narrow tissue regions. The results of the present study suggest that the dento-gingival junction as well as gingival epithelium play important roles in the process of exfoliation of human deciduous teeth.

Cell Division↗