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Biomedical subjects

H Yamakawa

Publications and source records attributed to H Yamakawa.

At least 19 recordsLinked to original sources
PubMed1998

Characterization of a new beta-spectrin gene which is predominantly expressed in brain.

We recently identified a gene which shows high similarity to the beta-spectrin gene but with a different chromosomal location from either of the two known beta-spectrin genes [T. Nagase, K.-I. Ishikawa, D. Nakajima, M. Ohira, N. Seki, N. Miyajima, A. Tanaka, H. Kotani, N. Nomura, O. Ohara, Prediction of the coding sequences of unidentified human genes: VII. The complete sequences of 100 new cDNA clones from brain which can code for large proteins in vitro, DNA Res. 4 (1997) 141-150]. In order to further characterize this new spectrin gene and its product, we isolated the rat counterpart of this gene and analyzed it in terms of its protein coding sequence, the tissue distribution of its mRNA and the product, and the regional distribution of the mRNA and the product in the brain. The results indicated that this gene was most abundantly transcribed in the brain and neurons were the predominant cell-type to express this gene. In particular, Purkinje cells were the richest in this gene product, and this new form of beta-spectrin was found more prominently in the dendrites than in the cell bodies. Since the expression pattern and the subcellular localization of this gene product were quiet distinct from those of the two beta-spectrin isoforms already characterized, this beta-spectrin gene would play an important role in neuronal membrane skeleton although it has been overlooked to date.

Amino Acid Sequence↗
PubMed1998

Identification of a 100-kb region of common allelic loss on chromosome bands 10q25-q26 in human endometrial cancer.

In human endometrial cancer, we have previously identified a 790-kb region of common allelic loss in chromosome bands 10q25-q26, flanked by D10S587 and D10S1723. We constructed a contig covering the entire deleted region using YACs, PACs, and BACs. Five overlapping cosmid clones derived from YAC clones completely covered the entire deleted region: its size was estimated to be no larger than 200 kb. We further performed two-color fluorescence in situ hybridization (FISH) analysis to confirm the deletion and narrowed down the deleted region to 100 kb or less; it was covered by three overlapping cosmid clones that were included in one BAC clone. Restriction endonuclease mapping identified a region in which NotI, SalI, SmaI, and Xhol were clustered, suggesting the possible existence of a CpG island.

Chromosome Banding↗
PubMed1998

Increased substance P in subacromial bursa and shoulder pain in rotator cuff diseases.

The subacromial bursa is recognized as a site associated with the shoulder pain caused by rotator cuff disease in the middle-aged and elderly. Substance P is contained in primary afferent nerves, and its quantity increases during chronic pain. The amount of substance P in the subacromial bursa of patients with rotator cuff disease was examined. Radioimmunoassay and immunohistochemistry were employed to quantify and localize substance P. The preoperative pain level was measured with a visual analogue scale with 0 as no pain, 5 as moderate, and 10 as severe. Thirty-seven patients that had undergone operation were divided into two groups: one composed of 19 patients with subacromial bursitis and a partial-thickness tear of the rotator cuff (nonperforated cuff) and the other composed of 18 patients with a full-thickness tear (perforated cuff). Subacromial bursae obtained from seven fresh cadavers with no shoulder pain before death were used as controls. The visual analogue scale showed significantly greater pain in the group with the nonperforated rotator cuff than in the group with the perforated cuff. Consistent with these results, the amount of substance P in the subacromial bursa was significantly greater in the former group than in the latter. Nerve fibers immunoreactive to substance P were localized around the vessels, with a larger number of fibers in the group with the nonperforated rotator cuff. Therefore, an increased amount of substance P in the subacromial bursa appears to correlate with the pain caused by rotator cuff disease.

Adult↗
PubMed1998

Properties of nicked and circular dumbbell RNA/DNA chimeric oligonucleotides containing antisense phosphodiester oligodeoxynucleotides.

We have designed a new class of oligonucleotides, 'dumbbell RNA/DNA chimeric phosphodiester oligonucleotides', consisting of a sense RNA sequence and its complementary antisense DNA sequence, with two hairpin loop structures. The reaction of the Nicked (NDRDON) and Circular (CDRNON) dumbbell DNA/RNA chimeric oligonucleotides with RNase H gave the corresponding antisense phosphodiester oligodeoxynucleotide together with the sense RNA cleavage products. The liberated antisense phosphodiester oligodeoxynucleotide was bound to the target 45 mer RNA, which gave 45 mer RNA cleavage products by treatment with RNase H. The circular dumbbell RNA/DNA chimeric oligonucleotide showed more nuclease resistance than the linear antisense phosphodiester oligodeoxynucleotide (anti-ODN) and the nicked dumbbell RNA/DNA chimeric oligodeoxynucleotide. The circularization, achieved by joining the 3' and the 5' ends of RNA/DNA chimeric oligonucleotides containing two hairpin loop structures, increases the oligonucleotide uptake into cells, as compared with the nicked dumbbell RNA/DNA chimeric oligonucleotide and the linear antisense phosphodiester oligodeoxynucleotides. When the circular dumbbell RNA/DNA chimeric oligonucleotide is directly delivered into retrovirus infected cells, its antisense phosphodiester oligodeoxynucleotide function appears.

DNA, Antisense↗
PubMed1998

Angiotensin I-converting enzyme gene polymorphism in intracranial saccular aneurysm individuals.

A polymorphism in the angiotensin I-converting enzyme (ACE) gene has been associated with cerebrovascular diseases as a new potent risk factor. The purpose of this study was to investigate an association of the gene polymorphism with intracranial saccural aneurysmal patients. The study population consisted of 83 aneurysmal patients (age range 41-85 years) (the AN group) and 104 matched control subjects (age range 30-81 years) (the Control group). For detection of the ACE gene polymorphism, the standard PCR method was performed by using genomic DNA isolated from peripheral blood leukocytes. The PCR products were a 490-bp in the presence of the insertion (I) and a 190-bp fragment in the absence of the insertion (D). The ACE gene polymorphism was classified into three genotypes: I/I genotype (a 490-bp band); D/D genotype (a 190-bp band); or I/D genotype (both a 490-bp and a 190-bp band). The number of subjects with I/I, I/D, and D/D genotypes was 38, 40, and 5 in the AN group and 43, 45, and 16 in the Control group, respectively. The frequency of the D/D genotype in the AN group was significantly lower (5/83 = 0.06) than that in the Control group (16/104 = 0.15) (chi 2 = 4.06; p = 0.044). There was no significant difference between the genotype sof hypertensive patients and normotensive patients in the AN group. Thus, this present study suggests that genetic heterogeneity of the ACE gene may be correlated with the etiology of intracranial aneurysms.

Adult↗
PubMed1998

Moyamoya disease associated with pulmonary sarcoidosis--case report.

A 61-year-old female presented with a unique case of moyamoya disease associated with pulmonary sarcoidosis. She was admitted for sudden onset of left temporalgia with episode of numbness on face, tongue, and upper extremity on the right side. The next morning, she had symptoms of Gerstmann syndrome and her ability to speak was disturbed. Her medical history included radical resection of lung cancer on the right side. She had no symptoms of pulmonary sarcoidosis. Neuroimaging showed an infarction in the left occipital lobe. Angiography showed occlusions of the bilateral internal carotid arteries at the supraclinoid portions. Subsequently, a left superficial temporal artery-middle cerebral artery anastomosis with encephalo-myo-synangiosis was performed. Ninety-three days after admission, she suddenly developed dyspnea which resulted in death 3 hours later. Autopsy findings showed typical epithelioid granulomas of sarcoid type in the lymph nodes of the peribronchus, lung, and liver. Thrombotic emboli were found in the bilateral pulmonary arteries, and marked fibrous intimal thickening in the bilateral internal carotid arteries. Immunological reaction with inflammatory events may cause pathological changes in patients with moyamoya disease or sarcoidosis. The co-incidence in this case suggests that some common inflammatory events may be involved in the pathogenesis of these diseases.

Carotid Artery, Internal↗
PubMed1997

Identification of a 790-kilobase region of common allelic loss in chromosome 10q25-q26 in human endometrial cancer.

We previously identified two commonly deleted regions on chromosome bands 10q25-q26 in endometrial cancer: an 8-cM region and a 12-cM region. In the present study, we further studied the 8-cM region with 83 endometrial cancer specimens and 14 microsatellite markers and narrowed it down to a 1-cM region between D10S587 and D10S1723. This result was confirmed by two-color fluorescence in situ hybridization analysis. An association between histopathologically lower grade tumor and allelic loss (P = 0.03 by Fisher's exact test) was also observed. We also constructed a yeast artificial chromosome (YAC) contig and found that one YAC clone, which was 790 kb in size, harbored the whole 1-cM region of common allelic loss.

Alleles↗
PubMed1997

A DNA cycle sequencing reaction that minimizes compressions on automated fluorescent sequencers.

We recently demonstrated that most band compressions (>70%) on DNA sequencing gels result from the presence of a single sequence motif, 5'-YGN1-2AR-3', where Y and R indicate base-pairing pyrimidine and purine residues, respectively. This finding raised the possibility that the use of 7-deaza-dATP instead of dATP in chain termination sequencing reactions would resolve most of the band compressions. Thus, we examined the effects of 7-deaza-dATP on DNA sequencing using thermostable DNA polymerases. The results indicate that the replacement of dATP with 7-deaza-dATP in conventional cycle sequencing reactions can successfully eliminate most band compressions without sacrificing sequencing performance.

Automation↗
PubMed1997

Oxygen-saving effect of a new cardiotonic agent, MCI-154, in diseased human hearts.

OBJECTIVES: The aim of this study was to examine the left ventricular mechanoenergetic effects of a novel Ca2+ sensitizing agent, MCI-154, on diseased human hearts compared with dobutamine. BACKGROUND: Unlike conventional cardiotonic agents, a Ca2+ sensitizer that could produce a positive inotropic action by altering the responsiveness of myofilament to Ca2+ could generate force with smaller amounts of Ca2+; thus, it may potentially save energy expenditure. METHODS: The left ventricular pressure-volume relation and myocardial oxygen consumption per beat (Vo2) were measured by a conductance (volume) catheter and a Webster catheter. Left ventricular contractility (Emax), systolic pressure-volume area (PVA [index of left ventricular total mechanical energy]) and Vo2 were assessed before and after infusion of MCI-154 or dobut-amine. The PVA-independent Vo2 (Vo2 mainly for excitation-contraction coupling) was assessed as the Vo2 at zero PVA. RESULTS: Both agents increased Emax comparably (dobutamine: from 3.55 +/- 1.10 [mean +/- SD] to 5.04 +/- 1.16 mm Hg/ml per m2, p < 0.0001; MCI-154: from 3.36 +/- 1.26 to 5.37 +/- 2.14 mm Hg/ml per m2, p < 0.0001); dobutamine increased total Vo2 (from 0.22 +/- 0.08 to 0.27 +/- 0.09 ml O2, p < 0.05) and PVA-independent Vo2 (from 0.019 +/- 0.019 to 0.091 +/- 0.051 ml O2, p < 0.005); but MCI-154 did not change these variables significantly. Consequently, the oxygen cost of contractility (delta PVA-independent Vo2/delta Emax) was less with MCI-154 than with dobutamine (0.14 +/- 0.18 vs. 1.10 +/- 0.80 J/mm Hg per ml per m2, p < 0.05). CONCLUSIONS: These results suggest that the cardiotonic action mediated by MCI-154 could provide an energetic advantage over the conventional cardiotonic action with currently used inotropic agents.

Aged↗
PubMed1997

Intrinsic healing capacity and tearing process of torn supraspinatus tendons: in situ hybridization study of alpha 1 (I) procollagen mRNA.

To determine the healing potential and healing process of torn supraspinatus tendons, in situ hybridization was used to localize cells containing alpha 1 type-I procollagen mRNA. Biopsy specimens of torn supraspinatus tendons from 19 patients with complete-thickness tears and 13 patients with incomplete-thickness tears were obtained during surgery. Four macroscopically normal supraspinatus tendons were obtained to serve as normal controls. Specimens were fixed in 10% buffered formalin and embedded in paraffin. A 22-mer oligonucleotide probe was labeled with digoxigenin and used as an in situ marker. The labeled cells were mainly composed of tenocytes and undifferentiated mesenchymal cells. In complete-thickness-tears, the labeled cells at the proximal tendon-stumps in the specimens that were obtained less than 4 months after trauma were significantly more abundant than in the specimens obtained 4 months or more after trauma. However, the number of labeled cells was maintained at the torn portion even in long-standing incomplete-thickness tears. The labeled cells at the margins of concomitant intratendinous extensions of the tears were detected even in the long-standing tears. The intratendinous extensions exhibited more labeled cells than the bursal-side or joint-side layers of the tendon substance in the incomplete-thickness tears (p < 0.05). The torn supraspinatus tendon may possess an intrinsic healing capability in the intermediate and late phases of tendon healing. Incomplete-thickness tears and concomitant intratendinous extensions can continue to rupture after the initial injury.

Adult↗
PubMed1997

Significance of granulation tissue in torn supraspinatus insertions: an immunohistochemical study with antibodies against interleukin-1 beta, cathepsin D, and matrix metalloprotease-1.

The pathophysiology of rotator cuff tears can be elucidated by examining the tendinous insertion of the supraspinatus muscle. As seen by light microscopy, the granulation tissue around the insertion of a torn supraspinatus tendon appears to induce osteochondral destruction by means of multinucleated giant cells and chemical mediators. The purpose of this study was to examine the contribution of certain chemical mediators to osteochondral destruction using immunohistochemical analysis of interleukin-beta, cathepsin D, and matrix metalloprotease-1. Sixteen supraspinatus insertions with portions of the greater tuberosity, including eight complete-thickness tears and eight incomplete-thickness tears, were obtained during surgery. Six fresh cadaveric supraspinatus tendons without grossly evident tears served as normal controls. Strong immunoreactivity was found in all 16 torn supraspinatus insertions but not in the six insertions of apparently intact tendons. Macrophages and multinucleated giant cells, which showed immunoreactivity for all three chemical mediators, were often found at the interface between the osteochondral margin of the enthesis and the granulation tissue, suggesting that they may be involved in osteochondral destruction. We therefore concluded that, in addition to repetitive subacromial impingement, this granulation tissue may contribute to the development of rotator cuff tears by weakening the insertion.

Adult↗
PubMed1997

Beneficial effects of a Ca2+ sensitizer, MCI-154, on the myocardial oxygen consumption-cardiac output relation in patients with left ventricular dysfunction after myocardial infarction: comparison with dobutamine and phosphodiesterase inhibitor.

Although conventional inotropic agents such as catecholamines increase myocardial oxygen consumption, a newly developed inotropic agent, a Ca2+ sensitizer, may be able to increase cardiac output with less myocardial oxygen consumption. By using right-side heart catheterization, we assessed the ratio of the increase in myocardial oxygen consumption per unit increase in cardiac output during beta-adrenergic receptor stimulation (dobutamine, n = 15), phosphodiesterase inhibition (E-1020, n = 10), and Ca2+ sensitization (MCI-154, n = 17) in patients with coronary artery disease. Dobutamine increased cardiac output and myocardial oxygen consumption. E-1020 increased cardiac output but did not change myocardial oxygen consumption. MCI-154 increased cardiac output and decreased myocardial oxygen consumption. The oxygen cost of increasing cardiac output with dobutamine and with E-1020 was different from that with dextran infusion (n = 18); in contrast, the oxygen cost with MCI-154 was significantly smaller. Thus a newly developed Ca2+ sensitizer, MCI-154, may be beneficial for the treatment of heart failure.

Cardiac Output↗
PubMed1997

Ovariectomy aggravated sodium induced hypertension associated with altered platelet intracellular Ca2+ in Dahl rats.

Our purpose was to determine the effect of ovariectomy on intracellular Ca2+ mobilization and platelet aggregation in sodium induced hypertension. At the age of 12 weeks ovariectomy or sham operation was performed in female Dahl-Iwai salt sensitive rats on a 0.3% NaCl diet. Four weeks later we assessed the effects of ovariectomy and an 8% NaCl diet on agonist induced intracellular Ca2+ mobilization in fura-2 loaded platelets and platelet aggregation. Ovariectomy enhanced the increase of systolic blood pressure and heart to body weight ratio on an 8% NaCl diet. However, thrombin evoked intracellular Ca2+ was not correlated with systolic blood pressure (r = -0.338, P = .17), and was lowered by sodium loading and ovariectomy (360+/-23 to 285+/-9, 296+/-10 nmol/L, P < .05). Furthermore, the ionomycin induced intracellular calcium fraction in the absence of external Ca2+ that reflected internal Ca2+ discharge capacity was reduced in ovariectomized rats compared with sham operated rats on an 8% NaCl diet (648+/-15 v 768+/-35 nmol/L, P < .05). The internal Ca2+ discharge capacity was inversely correlated with systolic blood pressure (r = -0.506, P = .03). In addition to the decreased internal Ca2+ discharge capacity, intracellular Ca2+-independent platelet aggregation by phorbol 12-myristate 13-acetate, a protein kinase C activator, was significantly enhanced in hypertensive rats. We concluded that ovariectomy enhanced sodium induced hypertension associated with the decreased internal Ca2+ discharge capacity and increased platelet aggregation in Dahl-Iwai salt-sensitive rats.

Animals↗
PubMed1997

Infrequent genetic alterations of the PTEN/MMAC1 gene in Japanese patients with primary cancers of the breast, lung, pancreas, kidney, and ovary.

In the present study, we searched for genetic alterations of the entire coding region of PTEN/MMAC1, a recently isolated candidate tumor suppressor gene, in 178 specimens from Japanese patients with various malignant tumors by the polymerase chain reaction-single strand conformation polymorphism method. The samples consisted of 11 glioblastoma multiformes (GBMs), 14 astrocytomas, 47 breast cancers, 25 non-small cell lung cancers, 9 small cell lung cancers, 8 pancreatic cancers, 24 renal cell carcinomas, 20 ovarian cancers, and 20 metastatic lung tumors from various organs. Only one somatic frameshift mutation at codon 319 was observed in one (9%) of eleven GBMs. Our results suggest that mutation of the PTEN/MMAC1 gene does not play a major role in carcinogenesis, at least in the tumor types from Japanese patients analyzed in this study.

Base Sequence↗
PubMed1997

Clinical analysis of recurrent subarachnoid hemorrhage after neck clipping surgery.

The clinical features of recurrent subarachnoid hemorrhage (SAH) after neck clipping surgery were investigated in a series of 1,436 consecutive patients treated between 1980 and 1994, and seven patients treated prior to 1980. Recurrent SAH occurred within 1 month in seven patients and between 1.5 and 20 years in 20 patients (mean interval 9.2 years) from the first surgery. The patients were aged from 31 to 76 years (mean 49.8 years) at the first SAH. There were 19 females and eight males. Recurrent SAH occurred at the same site as the prior aneurysms in 12 cases, at an infundibular dilatation in three cases, de novo aneurysms in nine cases, untreated multiple aneurysms in two cases, and unknown in one case. The main causes for early recurrent SAH were incomplete clipping or untreated multiple aneurysms, whereas late recurrent SAH was due to de novo aneurysms, untreated multiple aneurysms, or regrowth aneurysm at the prior site. The outcomes of late recurrent SAH were good in eight cases, moderate disability in two, severe disability in three, and dead in seven, whereas most cases of early recurrent SAH resulted in poor outcome. Immediate postoperative angiography is desirable in cases with incomplete clipping, because early recurrent SAH resulted in poor outcomes. De novo or regrowth aneurysms caused late recurrent SAH, so follow-up angiography is strongly recommended for young patients, even if complete clipping was achieved.

Adult↗
PubMed1997

[The roles of various media in the decision making processes for recycling behavior: a path analysis model].

This study researched the effects of cognitive variables on recycling behavior, as well as effects of various media of influence on the cognition and behavior. According to Hirose (1994), the decision making process for recycling consists of two steps. The first leads to goal intention of an ecological lifestyle. The second is related to behavior intention of recycling in line with the goal intention. Mass media, such as newspaper and TV, are thought to influence beliefs about environmental problems, including three determinants of goal intention: perception of seriousness, responsibility, and effectiveness. Personal media, such as personal contacts with pro-environmental activists, are thought to influence evaluation of behavior, including three determinants of behavior intention: evaluation of feasibility, cost and benefits, and social norms. Local media, such as municipal announcement and circular, are hypothesized to have a mixed effect of the two. Path analysis indicated that goal intention affected recycling behavior through behavior intention. Effects of the three media of influence on the cognitive variables were also consistent with the hypothesis.

Behavior↗