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Biomedical subjects

T Tahara

Publications and source records attributed to T Tahara.

At least 73 records · Page 4Linked to original sources
PubMed1996

Serum thrombopoietin (TPO) levels in patients with amegakaryocytic thrombocytopenia are much higher than those with immune thrombocytopenic purpura.

We assayed serum thrombopoietin (TPO) levels in amegakaryocytic thrombocytopenia (AMT) and immune thrombocytopenic purpura (ITP) patients by using a newly established enzyme-linked immunosorbent assay (ELISA). TPO levels in AMT patients were quite high (mean +/- SD = 13.7 +/- 11.2 fmoles/ml, n = 4), whereas those in ITP patients were only slightly higher (1.25 +/- 0.39, n = 12) than those of the healthy donors (0.55 +/- 0.2, n = 20). Furthermore, in ITP patients no correlation was observed between platelet counts and serum TPO levels (correlation coefficient = 0.14). We further assayed serum TPO levels sequentially during steroid treatment in patients with AMT and ITP. In one AMT patient serum TPO levels started to decrease in accordance with the increase of megakaryocyte counts, which preceded the increase in platelet counts. However, in ITP patients serum TPO levels did not change significantly throughout the course of the treatment despite the recovery of platelet counts. Based on these findings, we conclude that serum TPO levels may be regulated at least in part by megakaryocyte counts.

Adult↗
PubMed1995

Identification of the replication region of Lactobacillus acidophilus plasmid pLA103.

The structure of the region necessary for replication of the plasmid pLA103 from Lactobacillus acidophilus TK8912 has been characterized. Sequence analysis revealed that the replication region contained an open reading frame (OrfA) encoding a 282-amino acid peptide preceded by a 22-bp tandem repeat sequence region. The predicted OrfA protein showed homology to the replication protein of a plasmid from Pediococcus halophilus. The plasmid containing the repeat sequence region preceding OrfA was able to replicate in the Lactobacillus host when provided with OrfA in trans, suggesting that the repeat sequence region contains the origin sequence essential for the pLA103 replication.

Amino Acid Sequence↗
PubMed1995

NMR spectroscopic characterization of adinazolam mesylate: pH-dependent structure change in aqueous solution and active methylene.

The present study is to investigate structural changes of adinazolam mesylate in aqueous solution under various pH conditions by NMR spectroscopy. By plotting of the signal integration and chemical shifts of the side chain, pKa values for imine hydrolysis and the side chain amine were determined. Conformational analysis of the side chain was performed with deuterium-induced isotope effects on chemical shifts, nuclear Overhauser effects, relaxation times, and energy calculations. Hydrogen/deuterium exchange due to an active methylene at the 4-position under basic conditions was revealed.

Antidepressive Agents↗
PubMed1995

Hurler syndrome with severe complication in post-bone marrow transplantation course: life threatening interstitial pneumonitis and hypertension.

Bone marrow transplantation (BMT) was performed in a 3 year old patient with Hurler syndrome. The post-BMT course was complicated by interstitial pneumonitis and severe hypertension, which were life threatening. The patient responded well to therapy and recovered. BMT in this patient resulted in significant clinical improvement in the signs and symptoms of Hurler syndrome. Biochemical improvement, including elevated alpha-L-iduronidase activity in white blood cells and decreased urinary glycosaminoglycan excretion was significant. However, skeletal and neurological impairment were not improved. We conclude that BMT for Hurler syndrome should be performed at an earlier stage, before severe neuronal damage has occurred. Moreover, BMT is a high risk procedure and there will always be a possibility that life threatening complications will occur, as in our case.

Bone Marrow Transplantation↗
PubMed1995

Cloning and nucleotide sequence of the gene for acidocin 8912, a bacteriocin from Lactobacillus acidophilus TK8912.

Acidocin 8912 is a bacteriocin produced by Lactobacillus acidophilus TK8912. The acidocin 8912 structural gene, acdT, was cloned and determined. It was located on the 14-kb plasmid pL103 and encoded a 46 amino acid precursor including a 20 amino acid N-terminal extension. The precursor sequence of the acdT gene shows a conservation of the general structural characteristics of the bacteriocin precursors from some lactic acid bacteria.

Amino Acid Sequence↗
PubMed1995

Neurotological evaluation of Harada's disease.

We have had 30 patients with Harada's disease at our clinic from 1980 to 1993 and their neurotological findings were retrospectively reviewed. There were 12 males and 18 females, whose ages ranged from 15-years to 67-years. Preceding symptoms such as headache or common cold were observed in 50% of the patients. Pleocytosis of the cerebrospinal fluid was found in 89% of the patients. Subjective cochlear and/or vestibular symptoms were noted in 60% of the patients. In 43 of the 50 ears, sensorineural hearing loss (< 40 dB) was observed. In 77% of the patients, vestibular function tests gave abnormal results. On the basis of our findings, it was suggested that Harada's disease with vertiginous and cochlear symptoms could be classified as follows: cochlear type, peripheral vestibular type, cochleovestibular type, central type, and 'unclassified', based on the neurotological results.

Adolescent↗
PubMed1995

Effect of hypergravity on vestibular compensation in guinea pigs.

The effect of hypergravity on vestibular compensation was studied in guinea pigs. Pharmacological labyrinthectomy was performed by injecting chloroform into the middle ear cavity under ether anesthesia. The guinea pigs were exposed to hypergravity on a centrifuge. The animals were divided into four groups: a group stimulated with 2G after labyrinthectomy of the right ear, a group stimulated with 2G after labyrinthectomy of the left ear to evaluate the influence of the centrifugal rotation, a group stimulated with acceleration and deceleration alone, and a control group which was maintained under similar conditions, but without centrifugation. Head deviation and nystagmus were recorded and analysed to assess the process of compensation at 1, 3, 5, 7 and 9 h after labyrinthectomy. The 2G-stimulated group showed faster compensation in head deviation than the control group. In this study, the hypergravity stimulation seemed to facilitate the compensation in head deviation.

Adaptation, Physiological↗
PubMed1995

Expression of laminin in vestibular ganglia and nerves in herpes simplex virus infectious chick embryo.

The expression of laminin in the vestibular ganglia and nerves in herpes simplex virus I (HSV-I) infectious chick embryos was examined by immuno-histochemistry. In 9-day-old normal chick embryos, the surface of the vestibular ganglion cells and the vestibular nerves were labelled with laminin, while, in HSV-I infectious chick embryos, the staining of laminin in the vestibular ganglia and nerves was very weak. These results suggest that HSV-I injures vestibular ganglia and nerves, and that laminin is a good marker of the degeneration and innervation of developing vestibular nerves.

Animals↗
PubMed1994

A case of cerebellar infarction occurred with the 8th cranial nerve symptoms.

A rare case, 32-year-old man, of cerebellar infarction with the occurrence of the 8th cranial nerve symptoms was reported. On the neuro-otological examination, hearing test and caloric test showed a severe hearing loss and no response on the right side, respectively, and the spontaneous horizontal nystagmus fixed to the left direction was observed. Magnetic resonance (MR) imaging showed the infarctions in the areas of anterior inferior cerebellar artery (AICA) and posterior inferior cerebellar artery (PICA) on the right side. On the 14th illness day, the 8th cranial nerve symptoms disappeared, and on the 12th illness day, right hearing level and caloric response were significantly improved. We suggested that such an early recovery of the subjective symptoms and neuro-otological findings may be attributable to the recanalized circulation disturbance or the development of collateral circulation.

Adult↗
PubMed1994

Early onset of cecal perforation in neonatal, recto-sigmoid type Hirschsprung's disease.

Hirschsprung's disease has been considered to cause intestinal perforation in rare cases. Even if a perforation occurs, the majority of cases are associated with the long-segment or total colonic type. Our case developed the perforation in the neonatal period in spite of being of the recto-sigmoidal type, and it affected the cecum. We do not have a good explanation for this condition. However, the pathological examination of the specimens of the perforated cecum revealed some necrosis (ulceration, subcutaneous hemorrhage, congestion and severe edema) which was considered to be caused by ischemia, secondary to a localized vascular accident in the wall of the distended intestine.

Age of Onset↗
PubMed1994

[Effect of retroauricular galvanic stimulation on muscle atrophy in the unweighted rat hindlimb].

Hindlimb unweighting in the rat may serve as an experimental model simulating muscle atrophy under weightlessness. As a preventive measure, retroauricular galvanic stimulation was delivered to the unweighted rat hindlimb and the weights of the bilateral soleus and gastrocnemius muscles were compared. Wistar rats, with unweighted hindlimbs, were divided into two groups; the control group which received no galvanic stimulation and a galvanically stimulated group which received galvanic stimulation (bipolar biauricular, 1 mA in intensity, 500 msec in duration, 1 Hz in frequency) for one hour twice a day for 7 days using an electronic stimulator made by NIHON-KODEN (MODEL SEN-1101). The weights of the soleus and gastrocnemius muscles on both sides were measured in each group using a balance (METTLER AT201). The results were as follows: 1. Muscle weights in the galvanically stimulated group were greater than those in the control group. 2. A statistically significant difference between right and left soleus muscle weights was obtained in the galvanically stimulated group (P < 0.01). 3. We found no significant difference between the two sides in the weights of gastrocnemius muscles. It is presumed that retroauricular galvanic stimulation exerts some influence, not only on vestibular organs, but also on hindlimb muscles through the lateral vestibulo-spinal tract and, in addition, through the spinal motor neuron. Therefore, we speculate that galvanic stimulation might prevent atrophy of the unweighted hindlimb muscle.

Animals↗
PubMed1994

[Equilibrium of small animals in "drop shaft" experimentation--preliminary study on the frog with vestibular neurectomy].

We have newly designed instruments for equilibrium experimentation, using a drop shaft, and studied the behavior and EMG Patterns of frogs with or without unilateral vestibular neurectomy, as a preliminary study at JAMIC (Japan Microgravity Center). The results are reported herein and the efficacy of the drop shaft in equilibrium experimentation is also documented. 1) In unilateral vestibular neurectomized frogs, posture--head tilt, leg flexion on the affected side, and leg extension on the opposite side--is maintained and persists under microgravity. Rolling to the affected side was also observed. 2) The latencies of the EMG responses from M. tibialis anticus and M. longissimus dorsi were prolonged on the affected side. 3) The frog is suitable for use in equilibrium experiments utilizing a drop shaft. 4) The JAMIC drop shaft can be used to obtain constant and stable microgravity, 10(-4) G for 10 sec, which is similar to that in space. Drop shafts are suitable for equilibrium experimentation.

Animals↗
PubMed1994

[Relapse of acute leukemia after allogeneic bone marrow transplantation].

The relapses of 45 acute leukemia patients who underwent allogeneic bone marrow transplantation between April 1976 and February 1992 were analyzed clinically. The relapse rates of acute nonlymphocytic leukemia (ANLL) and acute lymphocytic leukemia (ALL) were 4/26 (15%) and 9/19 (47%), respectively. Although multivariate analysis could not be done, a high frequency of leukemia relapse was significantly associated with ALL, a younger age, history of extramedullary leukemia and blood-type identity. Chromosomal abnormalities at diagnosis, interval from diagnosis to bone marrow transplantation (BMT) and graft-versus-host disease (GVHD) prophylaxis were likely to be predictive of relapse. On the other hand, neither stage of leukemia at BMT, acute GVHD, sex, nor WBC count at diagnosis was a predictive factor. Eight of 10 relapsed patients achieved complete remission posttransplant, but the duration of remission was only 138 days on average. Four second BMT procedures for relapsed leukemia were carried out but were associated with many complications. However, one is alive well over 6 years after the second transplantation. There is a high treatment-related mortality following second BMT, but there is some possibility of long survival in some patients.

Adolescent↗
PubMed1993

Long persistent bcr-abl positive transcript detected by polymerase chain reaction after marrow transplant for chronic myelogenous leukemia without clinical relapse: a study of 64 patients.

We report here the results of polymerase chain reaction (PCR) for bcr-abl transcript and clinical details derived from 64 chronic myelogenous leukemia (CML) patients after allogeneic bone marrow transplantation (BMT). A total of 139 samples (2 to 220 weeks after BMT) were analyzed and bcr-abl transcript was detected in 99 samples from 52 patients. Patients were defined as bcr-abl early negative (EN) if they had > or = 1 negative PCR result < or = 1 year post-BMT (n = 13), and bcr-abl late positive (LP) if they had > or = 1 positive PCR result > or = 1 year post-BMT (n = 21). Among LP patients, only two patients had hematologic/cytogenetic (clinical) relapse. Another 19 LP patients remained in clinical remission 7 to 130 weeks after positive analysis for bcr-abl transcript, including 5 patients who had persistent bcr-abl transcript detectable even 2 years after BMT. To estimate the relationship between clinical data and residual bcr-abl transcript, EN patients are compared with LP patients. However, no clinical data studied were significantly associated with the persistent PCR positivity. If only patients in chronic phase are compared, the t-test showed significant correlation between leukocyte count just before BMT and sustained bcr-abl transcript (P < .05). These results suggest that PCR positivity is frequently observed in CML patients who sustain clinical remission after BMT, without being predictive of imminent clinical relapse. Tumor burden at the time of BMT may play an important role in the latency of bcr-abl positivity after BMT.

Adolescent↗
PubMed1993

Three independent mutations in the same exon of the PCCB gene: differences between Caucasian and Japanese propionic acidaemia.

Propionic acidaemia is an inborn error of organic acid metabolism caused by deficiency of propionyl-CoA carboxylase (PCC). Enzyme deficiency can result from mutations in either of the non-identical alpha- and beta-subunits. We have screened genomic DNA from patients with defects in the beta-subunit from two ethnic groups (Caucasians and Japanese) and detected three types of mutations in the same exon of the coding sequence of the beta-subunit: an insertion/deletion that replaces 14 nucleotides with 12 nucleotides of unrelated sequence and eliminates an Msp I site; a 3-bp deletion of a single isoleucine codon immediately proximal to that Msp I site; and a C-->T transition in the same Msp I site. The insertion/deletion was detected only in Caucasian patients in 11 of 34 mutant alleles; the C-->T transition was found only in Japanese patients in 4 of 12 mutant alleles. Following digestion of genomic DNA by Msp I, both of these mutations were detected on Southern blots by the presence of a 2.7-kbp band; they can be distinguished from one another by allele-specific oligonucleotide hybridization following PCR amplification. These results underscore the independent origin of the mutations in the two populations and suggest a key role of this exon in the beta-subunit of PCC.

Amino Acid Metabolism, Inborn Errors↗
PubMed1993

Human cystathionine beta-synthase cDNA: sequence, alternative splicing and expression in cultured cells.

Cystathionine beta-synthase (CBS) deficiency is the major cause of homocystinuria in humans. The most frequent symptoms of homocystinuria include: dislocated optic lenses, vascular disorders, skeletal abnormalities and mental retardation. Patients with this deficiency have elevated levels of homocyst(e)ine, methionine and low cysteine in their body fluids. These abnormal levels often partially or fully normalize upon treatment with pharmacological doses of vitamin B6. To investigate the molecular and biochemical basis for these conditions, it was necessary to determine the nucleotide and polypeptide sequence of CBS. We report here the human CBS cDNA sequence of 2,554 nucleotides encoding the CBS subunit of 551 amino acids. An intron of 214 bp appears to be retained in the 3'-untranslated region of most of the fibroblast and liver mRNA. We also report a frequent Mspl polymorphism in the 3'-untranslated sequence and two synonymous mutations in the coding region: 699C/T (Y233Y) and 1080C/T (A360A). The amino acid sequence similarity of human and rat CBS is greater than 90%; the enzyme also exhibits 52% similarity to O-acetylserine(thiol)-lyase from bacteria and plants. Lastly, we demonstrate that expression of the human enzyme in CHO cells yields enzymatically active protein of the expected size with a half-life of approximately 14 hrs.

Amino Acid Sequence↗
PubMed1993

[Ontogeny of the pronephros and mesonephros in the South African clawed frog, Xenopus laevis Daudin, with special reference to the appearance and movement of the renin-immunopositive cells].

Development of the pronephros and mesonephros of Xenopus laevis was morphologically studied in the larvae immediately after hatch (stage 35/36) to the end of metamorphosis (stage 66) together with the appearance of renin-immunopositive cells. The pronephros consisted of 3 pairs of pronephric tubules at stage 35/36 and became functional at stage 37/38 with the opening of the pronephric ducts to the cloaca. It increased thereafter in volume, but became degenerative at stage 56, lost a part of the pronephric ducts at stage 60, and completely disappeared at stage 64. The mesonephros displayed its anlage at stage 42, and gained the immature renal corpuscles at stage 48. At stage 49, it was equipped with the matured nephrons. The mesonephric tubules differentiated into the neck, proximal, intermediate and distal parts. The collecting tubules and ducts were also observed at this stage. At stage 56, a part of the mesonephric tubules degenerated and were displaced by newly formed tubules. Reorganization of the mesonephros was not completed at the end of metamorphosis. Renin-immunopositive cells did not appear in the pronephros, but were observed at the diverging part of the renal artery from the dorsal aorta, and in the walls of arteries and afferent arterioles within the mesonephros in a low frequency of appearance.

Animals↗