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Biomedical subjects

M Hidaka

Publications and source records attributed to M Hidaka.

At least 127 records · Page 7Linked to original sources
PubMed1989

[Peripheral superior cerebellar artery aneurysm. Case report].

The patient, a 37-year-old female, was hospitalized with a severe headache. Neurological examination on admission revealed no deficits except for neck stiffness and somnolence. Computed tomography showed a subarachnoid hemorrhage, which was especially prominent in the supracerebellar and quadrigeminal cisterns, but demonstrated no ventriculomegaly. Cerebral angiography on admission revealed no apparent abnormalities, but repeat angiography 8 days later disclosed a saccular aneurysm (2 X 3 mm) arising from the hemispheric branch of the left superior cerebellar artery (SCA). Three days after admission, the patient developed cerebellar dysarthria, which was assumed to be due to vasospasm. On the 24th day after admission, the aneurysm was successfully clipped through the infratentorial-supracerebellar approach. The postoperative course was uneventful and the patient was discharged with no neurological deficit. Nineteen other cases of peripheral SCA aneurysm have been reported in the literature. The presence of this type of aneurysm should be considered in patients who are fairly young and have focal neurological signs, such as third or fourth nerve palsy and/or cerebellar dysfunction. The prognosis for such patients is good, except in cases in which the neurological status is poor at the onset.

Adult↗
PubMed1989

[Low-dose dopamine treatment of patients in nonketotic hyperosmolar hyperglycemic coma].

In the acute neurosurgical setting, nonketotic hyperosmolar hyperglycemic coma (NHC) is thought to be caused by cerebral dehydration therapy and administration of steroids, glycerol, or mannitol. The mortality of this complication is reportedly very high, and is due to acute renal and/or cardiac failure. The authors evaluated the effect of low-dose dopamine (LDD; 1 to 5 micrograms/kg/min) administration in 10 patients with this syndrome. LDD was given to five patients. In these cases, hypovolemia was treated under central venous pressure monitoring with an iso-osmolar hyponatremic lactate solution given in a volume greater than the urine output. After the hypovolemia was corrected, the fluid was administered in a volume equal to the urine output until the serum osmolarity was normalized. In the five patients not given LDD, a large quantity of hypotonic solution was rapidly administered. In all patients treated with LDD, the urinary sodium increased and the urinary output stabilized. Consequently, the excess urea-nitrogen and serum sodium were quite easily washed out. The total net intake volume for the normalization of serum osmolarity was small and the duration of treatment was much shorter than that of patients not treated with LDD. The LDD regimen was not associated with complications, such as aggravation of cerebral edema, renal failure, or cardiac failure. On the other hand, three of the five patients not given LDD died of acute renal and/or cardiac failure without normalization of laboratory data. It is emphasized that this therapy, which results in beta-effect of catecholamine, sodium diuresis, and increased renal blood flow, is a practical means of managing acute neurosurgical cases complicated by NHC.

Adult↗
PubMed1989

[Case report: hemiballism due to a putaminal cavernous hemangioma].

A rare case of reversible hemiballism due to putaminal pathological process in a 51-year-old woman is described. She was hospitalized for evaluation of hemiballism and muscle weakness on the left side. A cranial computed tomography scan demonstrated a high density lesion in the right putamen with enhancement on delayed scan. Angiographic examination revealed no apparent abnormalities. Magnetic resonance imaging with T1 weighted showed a isodense lesion in the right putamen, while T2 weighted image revealed a ring like low signal area around a high signal lesion. These findings were compatible with the diagnosis of cavernous hemangioma. In order to establish the final diagnosis, CT-guided stereotaxic biopsy was carried out. But histological specimen showed only gliosis and calcification. Immediately after the biopsy, a small hemorrhage took place in the right putamen extending to the head of caudate nucleus head. Following this episode, hemiballism ceased, however, it gradually returned along with absorption of hemorrhage. The speculated pathophysiology of this on-and-off hemiballism was as follows; it initially developed as the result of suppression of inhibitory fibers from the striatum to the pallidum by a minor hemorrhage of putaminal cavernous hemangioma, and ceased by declining the activities of the pallidum due to interruption of excitatory fibers from the thalamus and the cortex to the striatum.

Brain Neoplasms↗
PubMed1989

["AB-Triple V" therapy of relapsed or refractory acute myelogenous leukemia].

Sixteen adults with acute myelogenous leukemia (AML) in relapse or refractory to conventional therapy were treated with AB-Triple V therapy. This regimen consists of aclarubicin, behenoyl cytosine arabinoside, etoposide, vincristine, and vinblastine or vindesine. Patients who obtained complete remission (CR) were then given monthly three courses of AB-Triple V therapy, and further courses of AB-triple V therapy every three months. Eleven of the 16 patients entered CR, three were no response, and two died early after initial AB-Triple V therapy. Among 11 patients who achieved CR, 7 are alive and in CR during 1 to 13 months, one died of hepatic failure, and three patients died of infection in CR. Systemic arthralgia following the administration of vinblastine were frequently observed. These results indicate that this salvage therapy are useful relapsed or refractory AML. Therefore, the role of this combination chemotherapy as a part of the initial post-remission therapy needs to be evaluated.

Aclarubicin↗
PubMed1988

A consensus sequence of three DNA replication terminus sites on the E. coli chromosome is highly homologous to the terR sites of the R6K plasmid.

Using the "Ter assay" we developed, three separate replication terminus (terC1, terC2, and terC3) sites on the E. coli chromosome were identified. The locations are at 28.3, 35.6, and 33.9 min on the linkage map, respectively. The terC1 site can block the counter-clockwise replication fork only, while the terC2 and terC3 sites inhibit the clockwise fork traveling on the chromosome. DNA sequences of the terC sites required for termination of DNA replication are highly homologous to those of terminus (terR) sites of the R6K plasmid, and the 21 bp consensus DNA sequence of terC is 5'-(A or T) TTAGTTACAACAT (A or C) CT (A or T) (A or T) (A or T) T-3'. In addition, all Ter active pUC-terC plasmids had a low copy number and were unstable in the host cells.

Base Sequence↗
PubMed1988

Core sequence of two separable terminus sites of the R6K plasmid that exhibit polar inhibition of replication is a 20 bp inverted repeat.

The DNA replication terminus (terR) of the R6K plasmid located on a 216 bp Alul fragment (Alu216) can block progress of the DNA replication fork. We previously developed an electrophoresis assay that allows detection of terminus activity on any DNA fragment cloned in the pUC vector. For precise identification of terR, we tested Alu216, its subfragments, and synthetic oligonucleotides by this assay. We found terR to be composed of a pair of separable sites, terR1 and terR2, each of which can block the DNA replication fork traveling in a specific but not the opposite direction. Both terR sites were composed of 22 nucleotides containing the repeated 20 bp sequence 5'-TAGTTACAACAC(A or T) CAA(G or T) AGA-3', located 73 bp apart in the inverted position of Alu216. A DNA homology search suggested that the R6K plasmid and the E. coli chromosome share a common termination system.

Base Sequence↗
PubMed1988

Post-transcriptional regulator (rex) of HTLV-1 initiates expression of viral structural proteins but suppresses expression of regulatory proteins.

Gene expression of human T-cell leukemia virus type 1 (HTLV-1) is regulated by two trans-acting factors encoded by the pX region, p40tax and p27tax.p40tax is a transcriptional activator and p27rex is a post-transcriptional regulator. Using full-length viral DNA, we studied the regulatory effects of rex on HTLV-1 gene expression. p27rex is required for expression of both gag and env proteins, increasing the level of their mRNAs. The effect was dependent on the dose of p27rex expression plasmid. In parallel, increased doses of p27rex suppressed the expression of fully spliced pX mRNA, which encodes the regulatory proteins. These two effects of p27rex operated at the post-transcriptional level and were independent of transcriptional regulation. Lowering the level of pX mRNA down-regulates transcription of the proviral genome. These observations demonstrate that rex is a positive post-transcriptional regulator for gag, pol and env protein expression, and acts at the same time as an indirect negative regulator of viral transcription.

Cell Line↗
PubMed1988

Alteration of infection pattern of duck hepatitis B virus by immunomodulatory drugs.

The relationship between host immune state and hepatic inflammation and infection pattern of the Duck hepatitis B virus (DHBV) was investigated by experimental transmission of DHBV into 98 Japanese 7-day-old ducklings that had been pretreated with immunoregulatory drugs including cyclophosphamide, OK 432, and a steroid hormone. Immunosuppressive treatment with cyclophosphamide revealed an extension of the viremic period associated with an absence of inflammatory changes in the liver. Although immunostimulating treatment with OK 432 showed a remarkable accumulation of inflammatory cells in the liver, the viremic period was not shortened. Treatment with a steroid used as a immunosuppressant did not suppress the hepatitis; moreover, it increased viral DNA replication and extended the viremic period. This phenomenon of viral replication seemed to be caused by the direct effects of the steroid. Alteration of DHBV infection by modifying the host immune state is quite similar to that of hepatitis B virus (HBV) in humans. In DHBV infection, the host immune state seemed to have a considerable role in determining the infection pattern and degree of hepatitis activity. DHBV may be a helpful model of HBV for studying host-viral interaction and the immunological mechanism of viral hepatitis.

Adjuvants, Immunologic↗
PubMed1988

An experimental study on viability of the devascularized trachea.

This experiment was designed to evaluate the effect of varying extents of devascularization to the viability of the trachea, and the influence of preservation of the right bronchial artery on the ischemia of the widely devascularized trachea. In experiment 1, the canine trachea was devascularized in a stepwise manner, and the regional blood flow was measured in each situation. This experiment revealed that the regional blood flow decreased to one-third of the non-treated trachea when the bilateral bronchial arteries were transected, and to nil when the cervical and mediastinal trachea was devascularized. In experiment 2, in which dogs were divided into 2 groups depending on preservation of the right bronchial artery, the trachea was stepwisely devascularized and the regional blood flow measured. This experiment indicated that the regional blood flow in the trachea when the right bronchial artery was preserved did not so remarkably diminish, though the cervical and mediastinal trachea was devascularized. In experiment 3, dogs were divided into 3 groups according to the extent of devascularization of the trachea and to the presence or absence of the preserved right bronchial artery, and were followed for 2 months postoperatively. This experiment demonstrated that the preservation of the right bronchial artery prevented tracheal necrosis caused by devascularization of the cervical and mediastinal trachea. We concluded that the regional tracheal blood flow markedly decreased and that tracheal necrosis occurred following devascularization of the cervical and mediastinal trachea when the bilateral arteries were transected. The preservation of the right bronchial artery however, prevented a decrease in the regional blood flow and necrosis of the widely devascularized trachea.

Animals↗
PubMed1988

Two cis-acting elements responsible for posttranscriptional trans-regulation of gene expression of human T-cell leukemia virus type I.

The pX sequence of human T-cell leukemia virus type I codes for two nuclear proteins, p40tax and p27rex, and a cytoplasmic protein, p21x-III.p40tax activates transcription from the long terminal repeat (LTR), whereas p27rex modulates posttranscriptional processing to accumulate gag and env mRNAs that retain intron sequences. In this paper, we identify two cis-acting sequence elements needed for regulation by p27rex: a 5' splice signal and a specific sequence in the 3' LTR. These two sequence elements are sufficient for regulation by p27rex; expression of a cellular gene (metallothionein I) became sensitive to rex regulation when the LTR was inserted at the 3' end of this gene. The requirement for these two elements suggests an unusual regulatory mechanism of RNA processing in the nucleus.

Gene Expression Regulation↗
PubMed1988

[Autotransplantation of nipple-areolar complex in a modified radical mastectomy--indications and three-stage breast reconstruction].

Necessity of breast reconstruction after mastectomy has been increasing in recent years. For better reconstruction, we preserve a nipple-areolar complex (NAC) by transplanting it temporarily onto the lower abdominal wall and retransplant it to the restored breast mound in a subsequent operation. Indications for NAC preservation are as follows: (1) by palpation the tumor is found to be smaller than 3.0cm in diameter without apparent regional and distant metastasis, (2) neither abnormal nipple discharge nor nipple retraction is observed, (3) tumor is remote more than 3.0cm from the areolar margin, (4) no abnormal shadows are seen below the nipple and areola in the mammogram, (5) no microscopic extension of the cancerous cells is detected beneath the resected NAC. We have performed 18 transplantations using this procedure with good cosmetic results. There were no recurrent cases due to NAC preservation. It is concluded that this technique for preserving the NAC by autotransplantation is easy to perform and useful for breast reconstruction because of low risk of recurrence and better cosmetic results.

Adult↗
PubMed1987

Replication intermediate of a hybrid plasmid carrying the replication terminus (ter) site of R 6K as revealed by agarose gel electrophoresis.

A 4.32 kb DNA fragment, on which the DNA replication terminus (terR) site of plasmid R 6K was located, was inserted into the unique EcoRI site of plasmid pUC9. To detect replication intermediate molecules with a replication fork halted at the terR site, a cell DNA extract was digested with EcoRI, electrophoresed through an agarose gel and stained with ethidium bromide. In addition to two major bands, one derived from vector DNA and the other from the ter insert fragment, two extra minor bands were detected. Following DNA-DNA hybridization and electron microscopic observation we concluded that the two minor bands corresponded to the two Y-shaped molecules, produced from the theta-shaped intermediate molecules by EcoRI digestion.

DNA Replication↗
PubMed1987

The latissimus dorsi muscle flap is useful for the repair of tracheal defects--an experimental study.

An experiment was designed to evaluate the limitations of the muscle flap method in treating various locations and sizes of tracheal defects. Five groups of dogs with several types of tracheal defects were prepared. Each defect was covered by the latissimus dorsi muscle flap. Defects of the tracheal membrane (posterior one-third of the tracheal wall) were successfully repaired by the muscle flap without stenosis, even if they extended to 10 rings in length or were situated at the carina. Defects in the posterior one-half of the trachea, up to 5 rings long, were repaired, with minimal stenosis. Defects of the posterior two-thirds, or anterior one-third of the trachea, resulted in marked stenosis following muscle flap repair. Tracheal movement as seen in the saver sheath type of tracheomalasia was observed when anterior support of the trachea was lost. On the other hand, the movement seen in the crescent type of tracheomalasia was observed when posterior support of the trachea was lost. We concluded that a defect of less than the posterior one-half of the trachea can be repaired by muscle flap, without inducing respiratory insufficiency. Therefore, muscle flap coverage for tracheal defects should be a useful technique in the combined resection of the tracheobronchial tree in cases of esophageal cancer.

Animals↗
PubMed1986

Cloning and structural analysis of the calf prochymosin gene.

Calf prochymosin (cPC) gene was cloned from calf abomasum DNA by using a cloned cPC cDNA as a probe. The cPC gene spans approx. 10.5 kb and consists of 9 exons and 8 introns. The positions of exon-intron junctions coincide completely with those in the human pepsinogen gene. Analysis of 5'-flanking region sequence and S1 nuclease mapping revealed that the transcriptional start point was located 25 bp upstream from the start codon and that the putative transcriptional promoter sequences (TATA box and CCAAT box) were located in -30 and -90 regions, respectively. Some distinctive sequences possibly functioning as regulatory signals for gene expression are present at the 5'-flanking region.

Amino Acid Sequence↗