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Biomedical subjects

M Kanazawa

Publications and source records attributed to M Kanazawa.

At least 55 records · Page 3Linked to original sources

Novel mutation of L718X in the ATP7A gene in a Japanese patient with classical Menkes disease, and four novel polymorphisms in the Japanese population.

Menkes disease is an X-linked recessive disorder of the copper membrane transport system caused by mutations in the ATP7A gene. While various mutations in the ATP7A gene have been reported, a genotype-phenotype correlation has not been clearly defined. A novel mutation in the ATP7A gene in a Japanese patient with classical Menkes disease was identified via analysis of reverse-transcriptase polymerase chain reaction products and genomic DNA of the ATP7A gene. The nonsense mutation, L718X, was found to result in premature termination and immature ATP7A protein, unlikely to have normal functioning. Therefore, this nonsense mutation of the ATP7A gene is proposed to play a causative role in presenting the classical Menkes phenotype. Furthermore, four novel polymorphisms, C1535T (L464L), C2151T (T669I), G2253A (R703H), and C3677T (H1178Y) were also identified.

Adenosine Triphosphatases↗

Quantitative analysis of cell allocation during liver development, using the spf(ash)-heterozygous female mouse.

Mosaicism of ornithine transcarbamylase (OTC) expression in hepatocytes was quantitatively analyzed during liver development of the spf(ash)-heterozygous female mouse. Because the mosaic patterns depend on cell migration and cell mixing, such analysis could give insights on the growth pattern or allocation pattern of hepatocytes during liver development. Complex mosaic patterns of OTC-positive and -negative hepatocytes were observed in sections of fetal and postnatal livers. Sizes of patches, which were aggregates of OTC-positive or -negative hepatocytes, increased during development. Patches were slender and comparatively simple in 15.5- and 17.5-day fetal and neonatal livers. Quantitative analysis of patch shapes demonstrated that undulation of patches was maximal at 7 postnatal days. Patches with nodular shapes also started to increase in number at this stage. Isolated patches in sections of fetal livers and postnatal livers three-dimensionally connected with one another. However, especially in fetal livers, in which OTC-positive patches were minor, due to the presence of abundant hemopoietic cells, isolated three-dimensional patches consisting of approximately 5 to 70 cells were often found. They were shaped like slender branching or zigzag-shaped cords, but no definite orientation such as portal-central was observed in them at any stage. These results suggest that hepatocytes contiguously allocate their daughter cells as zigzag-shaped or branching cords at younger stages. Some hepatocytes grow with nodular formation after 7 postnatal days. Migration and mixing of hepatocytes appear to be more extensive at fetal stages than in the adult liver. Immunohistochemical analysis of intercellular junction proteins (E-cadherin, connexins 26 and 32, occludin, and ZO-1) also revealed that their expression and distribution changed in hepatocytes during development, which may be correlated with the OTC mosaic patterns.

Aging↗

Renal-protective effect of nondepressor dose of cicletanine in diabetic rats with hypertension.

We assessed the renal and cardiac benefits of cicletanine (CIC), a furopyridine derivative drug with diuretic and antihypertensive properties, in diabetic spontaneously hypertensive rats with renal impairment. Uninephrectomized streptozotocin (STZ)-diabetic spontaneously hypertensive Izmo rats (SHRIzm) (10 weeks old) were randomly assigned to receive vehicle or CIC (100 mg/kg/day, orally), and age-matched, uninephrectomized STZ diabetic Wistar-Kyoto Izmo rats (WKYIzm) were assigned to receive vehicle for up to 12 weeks. Blood pressure increased progressively in diabetic SHRIzm but not in diabetic WKYIzm. Urinary albumin excretion increased significantly in both diabetic SHRIzm and diabetic WKYIzm throughout the experiment. The antihypertensive effect of CIC was not significantly observed in diabetic SHRIzm. However, the subdepressor doses of CIC significantly decreased urinary albumin excretion, serum creatinine, and blood urea nitrogen in diabetic SHRIzm. These results were confirmed by morphological analysis of kidneys in each group of rats. The index of focal glomerular sclerosis (FGS) in diabetic SHRIzm was significantly higher than that in diabetic WKYIzm. The CIC treatment significantly and effectively protected against an increase in the index of FGS in diabetic SHRIzm. Moreover, CIC treatment significantly attenuated the increase in the heart weight to body weight ratio in diabetic SHRIzm. Treatment with CIC did not affect urinary and blood glucose concentrations at this dose. These results suggest that CIC has a renal-protective action, which is not related to improvement of diabetes or improvement of high blood pressure in diabetic rats with hypertension. The action might be due to the reduction of intraglomerular capillary pressure or protection of the renal glomerular vascular endothelial cell injury and mesangial cell injury through stimulation of PGI2 generation or elimination of free radicals, although the mechanism remains to be further investigated.

Albuminuria↗

Abnormal visceral perception in patients with functional dyspepsia: use of cerebral potentials evoked by electrical stimulation of the oesophagus.

Altered visceral perception is thought to be included in the pathogenesis of functional dyspepsia. However, in previous studies, the assessment of visceral perception has been based solely on patients self-reported symptoms. Cerebral evoked potential (EP), either by mechanical or electrical stimulation (ES) of the visceral organ, is used to evaluate visceral perception via afferent neural pathways. In this study, we investigated the visceral perception in patients with functional dyspepsia by EP to eliminate the possibility of self-reported bias. EP responses were recorded by oesophageal ES at 37 cm from the nostril in 14 patients with functional dyspepsia and 14 normal healthy control subjects. Threshold levels of perception, peak latencies and peak-to-peak amplitudes of EP were evaluated. There was no difference in the sensory threshold between the dyspeptic patients and the control subjects (median 6 mA, range 2-12 mA, vs. 8 mA, range 6-14 mA; P= 0.09). There was a strong trend towards a decreased discomfort threshold in the patients when compared to the control subjects (median 14 mA, range 6-24 mA vs. 20 mA, range 14-26 mA; P = 0.05). The latency of the later EP peak (N2) among the patients (154 ¿ 4 ms) was significantly shorter than that of the control subjects (171 ¿ 3 ms, P < 0.01) although there was no difference between the earlier peaks (Ni and P1). There was also no difference in the amplitudes (Ni/Pi and P1/N2) of EP between the patients and the control subjects. Half of the patients (seven out of 14) complained of nausea during ES but the control subjects were unaffected. The latency of the first EP peak (Ni) in the patients with nausea was significantly shorter (66 ¿ 3 ms) than that of the patients without nausea (79 ¿ 4 ms, P 0.05) or among the control subjects (80 ¿ 3 ms, P < 0.05). These results suggest that dyspeptic patients may recruit a greater number of fast conducting myelinated nerve fibres that convey visceral afferent impulses to the brain and/or that dyspeptic patients may have an altered central processing of the visceral perception. We conclude that EP recording by oesophageal ES provides an objective measurement of altered visceral perception in patients with functional dyspepsia.

Adolescent↗

Cardiac infarcts increase sodium transporter transcripts (rBSC1) in the thick ascending limb of Henle.

BACKGROUND: Enhanced expression of the kidney-specific sodium transporter, rBSC1, in the thick ascending limb of Henle (TAL) and of the renal water channel, aquaporin-2 (AQP2), in collecting duct has been identified in rats with congestive heart failure (CHF) as a cause for enhanced sodium and water retention in this condition. However, the mechanism of impaired urinary sodium excretion observed even in rats with mild cardiac dysfunction remains unknown. METHODS: Male Sprague-Dawley rats with myocardial infarctions measuring 15 to 30% of the left ventricular circumference with no overt CHF were prepared. We measured the amount of rBSC1 or AQP2 mRNA using competitive polymerase chain reaction (PCR) by inducing a point mutation at the middle of the PCR product for rBSC1 or by deleting 180 bp from the 760 bp PCR product for AQP2, respectively. The results were confirmed by in situ hybridization. rBSC1 protein expression was examined by immunohistochemistry and Western blot analysis using a specific antibody against rBSC1. RESULTS: Although plasma renin activity was slightly elevated in rats with myocardial infarction (MI), no significant differences in lung weight or plasma concentrations for aldosterone and atrial natriuretic peptide were observed between control rats and MI rats. Competitive PCR showed a significant increase in rBSC1 mRNA in the renal outer medulla and cortex of MI rats, which was confirmed by in situ hybridization. However, the AQP2 mRNA of these rats remained unchanged throughout the kidney. Renin-angiotensin II blockade by oral captopril administration did not influence the alteration in rBSC1 mRNA induced by myocardial infarction. Immunohistochemistry and Western blots showed the enhanced expression of rBSC1 protein in TAL of rats with small to moderate cardiac infarcts. CONCLUSIONS: rBSC1 is up-regulated even in rats with small to moderate myocardial infarctions, which may enhance the sodium transport in the TAL in this pathophysiologic condition.

Animals↗

17Beta-hydroxysteroid dehydrogenase type 1 and type 2 in human breast carcinoma: a correlation to clinicopathological parameters.

The expression of 17beta-hydroxysteroid dehydrogenase (17beta-HSD) type 1 and type 2 was examined immunohistochemically in 111 invasive ductal carcinomas, and correlated with various clinicopathological parameters. This study investigates local regulatory mechanisms of oestrogens in human breast carcinoma. 17Beta-HSD type 1 was immunolocalized in carcinoma cells of 68 out of 111 invasive ductal carcinoma cases (61.3%). 17Beta-HSD type 2 immunoreactivity was not detected in all cases examined. A significant inverse correlation was observed between the immunohistochemical expression of 17beta-HSD type 1 and histological grade of the carcinoma (P < 0.02). There was a significant correlation between 17beta-HSD type 1 and oestrogen receptor (ER) labelling index (LI) (P < 0.05). In addition, carcinoma cells expressing immunoreactive 17beta-HSD type 1 were frequently positive for ER. 17Beta-HSD type 1 was also correlated with progesterone receptor (PR) LI (P < 0.05). There was a significant inverse correlation between 17beta-HSD type 1 and Ki-67 LI (P < 0.0001). No significant correlations were detected between 17beta-HSD type 1 and other clinicopathological parameters, including patient age, menopausal status, stage, tumour size, lymph node status and prognosis. This study suggests that 17beta-HSD type 1 plays an important role in the regulation of in situ oestradiol production in hormone-dependent breast carcinomas.

17-Hydroxysteroid Dehydrogenases↗

Importance of interleukin-8 in the development of reexpansion lung injury in rabbits.

Reexpansion of a collapsed lung induces increased microvascular permeability leading to reexpansion pulmonary edema (REPE). This study was designed to prove the hypothesis that local overproduction of interleukin-8 (IL-8) induces inflammatory cell accumulation which leads to the induction of REPE. Initially, we examined the detailed characteristics of a rabbit model of REPE in association with IL-8 production and its mRNA expression. The lung tissue to plasma ratio of radiolabeled albumin (T/P ratio), the lung wet to dry ratio, and bronchoalveolar lavage (BAL) neutrophil counts were significantly increased in the reexpanded lung. IL-8 concentrations and mRNA expression were significantly increased in the reexpanded lung homogenate. Immunohistochemically, alveolar macrophages (AMs) and epithelial cells in the reexpanded lung and AMs in the collapsed lung were positive for IL-8. Second, we examined the effect of pretreatment with a specific monoclonal anti-IL-8 antibody (Ab) or control IgG on the development of REPE. The T/P ratio and BAL neutrophil counts were conspicuously decreased by pretreatment with anti-IL-8 Ab, but not with control IgG. On a histopathological study, lung injury and leukocyte infiltration were attenuated by the pretreatment with anti-IL-8 Ab. In conclusion, IL-8 production is enhanced in the reexpanded lung, and contributes to the development of REPE. The pretreatment with anti-IL-8 antibody may be useful as a novel protective therapy for this disease.

Animals↗

Immunohistochemical and chemical changes of beta-citryl-L-glutamate in the differentiation of bovine lens epithelial cells into lens fiber cells.

Beta-citryl-L-glutamate (beta-CG) concentration was determined by HPLC during the differentiation of bovine lens epithelial cells into lens fiber cells in culture. beta-CG increased from 1 to 4 weeks of culture and then decreased slightly, while alpha-crystallin, a marker of lens cell differentiation, increased rapidly 4 weeks after the culture and continued to increase gradually until week 11. In addition, the localization of beta-CG was immunohistochemically examined using anti-beta-CG antibody. Cells around lentoid bodies were stained with anti-beta-CG antibody, whereas cells in the bodies were stained strongly with anti-gamma-crystallin antibody. These findings suggest that beta-CG accumulated immediately before the differentiation of the bovine lens epithelial cells into lens fiber cells and may play a role in regulating the differentiation of lens cells.

Animals↗

Novel A-seco-rearranged lanostane triterpenoids from Abies sachalinensis.

From the needles of Abies sachalinensis, novel rearranged lanostane type triterpenes, 1-4, were isolated along with a known triterpene (5). The structures of the new compounds, 1-4, were elucidated to be 3,4-seco-8-(14-->13R)abeo-17,13-friedo-9beta-lanosta-4(28),7,14(30),22Z,24-pentaen-26,23-olide-3-oic acid, methyl 3,4-seco-8-(14-->13R)abeo-17,13-friedo-9beta-lanosta-4(28),7,14(30),22Z,24-penten-26,23-olide-3-oate, 3,4-seco-8(14-->13R)abeo-17,13-friedo-9beta-lanosta-4(28),7,14,22Z,24-pentaene-26,23-olide-3-oic acid and methyl 3,4-seco-8(14-->13R)abeo-17,13-friedo-9beta-lanosta-4(28),7,14,22Z,24-pentaene-26,23-olide-3-oate, respectively, by means of spectral experiments, especially two dimensional NMR spectroscopy, such as 1H-detected multiple quantum coherence (HMQC), 1H-detected heteronuclear multiple bond connectivity (HMBC) and 1H-1H-correlation spectroscopy (COSY) experiments. These new compounds have novel structures containing A-seco, rearranged spiro structure and a gamma-lactone conjugated with a diene. Some of these compounds showed potent antibacterial activity against gram positive bacteria.

Anti-Bacterial Agents↗

[A questionnaire survey on the self-assessment to the asthmatic treatment in Saitama Prefecture: results from 2825 cases].

The aim of this study was to survey the self-assessment to the treatment of adult bronchial asthmatics in Saitama prefecture. A questionnaire on daily symptoms and medications was distributed to 2825 adult asthmatic subjects who were treated at 125 hospitals/clinics in Saitama prefecture between September 15th and October 30th 1998. More than half (52.7%) of patients described that their general condition of asthma was poorly controlled. Even among the patients described that their condition was good or fair, 30.2% of them had some asthmatic symptoms such as shortness of breath or nocturnal awakening. Although inhaled corticosteroids were used in 66.2%, the ratio of patients who used spacer and kept drug compliance as prescribed were 59.6% and 45.8%, respectively. According to the physician's reports, cysteinyl leukotriene antagonist was used in 35.7%, which was comparable to the total of another anti-allergic drugs (37.3%). These results suggest that more than half of asthmatic patients in Saitama prefecture were not satisfied with their conditions of the disease control. Furthermore, more thorough education on the technique and compliance of inhaled corticosteroids would be required.

Adolescent↗

[Gastroesophageal reflux and respiratory diseases].

There is a relationship between gastroesophageal reflux and respiratory diseases. Reflux may trigger and aggravate respiratory diseases especially bronchial asthma. Both clinical and experimental observations suggest that the pathogenic mechanisms may be a vagal reflex and/or microaspiration of gastric acid into the trachea. General measures to avoid reflux and proton pomp inhibitor together with inhaled corticosteroid are the choice for treatment of asthma associated with gastroesophageal reflux. Xanthine derivatives and beta 2 adrenergic agonist might be withheld in these patients. A laparoscopic surgical treatment may be an option for patients with persistent symptoms.

Asthma↗

[A questionnaire survey of surgical lung biopsy in patients with diffuse lung diseases].

A nationwide questionnaire survey was conducted to investigate the indications, diagnostic yield, complications, outcome, and benefit of surgical lung biopsy for diffuse lung diseases. Surgical lung biopsies were performed in 410 patients at 132 institutes in 1998, 94% of them as video-assisted thoracoscopic surgery (VATS). Interstitial lung diseases of unknown etiology formed the largest diagnostic group, and consisted of 194 patients. The clinical diagnosis prior to lung biopsy was inconsistent with the final diagnosis in 32.8%. Complications were seen in 32 patients, and mortality was 1.2%. Acute exacerbation of the underlying disease was seen in 9 patients, four of whom died. Patients with nonspecific interstitial pneumonia and even usual interstitial pneumonia who were treated following biopsy showed better outcomes than those untreated. The physician in charge judged that 82.2% of the patients received clinical benefits from the biopsy procedure. We concluded that VATS lung biopsies are indicated in more cases to confirm diagnoses and as a reference for treatments in patients with diffuse lung disease.

Adolescent↗

[Familial summer-type hypersensitivity pneumonitis in a grandfather and his two-and-a-half-year-old grandson].

We encountered a family in which two of the six members, the grandfather and his grandson, had summer-type hypersensitivity pneumonitis in late summer. Chest computed tomography of these patients showed small, diffuse nodular shadows in both lung fields, with mosaic-like opacities in the grandfather and ground glass opacity of both lung fields in the grandson. Bronchoalveolar lavage fluid from the grandfather disclosed high total cell counts, high percentages of lymphocytes, and a low ratio of CD 4+ cells to CD 8+ cells. Transbronchial lung biopsy specimens obtained from the same patient revealed alveolitis with non-caseous epithelioid cell granulomas in the interstitium and Masson bodies in the alveolar septa. These two patients recovered spontaneously after hospital admission. They had positive results in provocation tests for their home and were positive for serum anti-Trichosporon cutaneum (T. asahii, T. mucoides) antibodies. Both cases were accordingly diagnosed as summer-type hypersensitivity pneumonitis.

Aged↗

Therapeutic advantage of angiotensin converting enzyme inhibitors in chronic glomerulonephritis.

Hypertension in chronic progressive renal disease is a major clinical problem leading to renal function loss. We studied the influence of ambulatory blood pressure (ABP) and the effect of hypertension therapy on renal function in 116 patients with chronic glomerulonephritis. Patients were subdivided as hypertensive, normotensive and hypotensive according to the level of ABP and age. Hypotensive subjects showed improvement of renal function and normotensive subjects showed slower rate of progression of renal function loss than hypertensives, suggesting the adequate level of ABP was 100-125/55-75 mm Hg in patients less than 40 years old, 100-135/60-80 mm Hg in patients 40-60 years old, and 105-140/60-85 mm Hg in patients over 60 years, respectively. The renal protection of calcium antagonists was associated with achieving lower blood pressure levels, whereas the blood pressure level did not affect progression of renal function in patient treated with angiotensin converting enzyme (ACE) inhibitor. ACE inhibitor, but not calcium antagonists, showed a reduction of urinary protein excretion. Thus, the mechanisms of renal protection were different between ACE inhibitors and calcium antagonists.

Adolescent↗

Identification of three novel mutations in the MNK gene in three unrelated Japanese patients with classical Menkes disease.

Menkes disease is an X-linked recessive disorder of the copper membrane transport system caused by mutations to the Menkes (MNK) gene. We identified three novel mutations of the MNK gene in three unrelated Japanese patients with classical Menkes disease by analyzing reverse-transcriptase polymerase chain reaction products and genomic DNA of the MNK gene. Firstly, an insertional mutation was found, 1173 ins A, which led to a premature termination and resulted in a very immature Menkes protein. Secondly, we found a point mutation, T2763G, resulting in a leucine-to-arginine conversion, which we predicted would cause a change in the secondary structure of the Menkes protein. Finally, we identified a splicing mutation, 2317 + 5G > C, which resulted in the skipping of both exons 8 and 9 or exon 9 only, and led to a truncation of the protein. Each of these mutations is hypothesized to destroy copper-ATPase-mediated copper transport. We propose that each of these mutations in the MNK gene plays a causative role in the disease.

Adenosine Triphosphatases↗

An Ile/Val polymorphism at codon 1464 of the ATP7A gene.

An isoleucine/valine polymorphism was observed at codon 1464 of the ATP7A gene, which is thought to encode a copper transporting adenosine triphosphatase (ATPase). The frequency of Val1464 was estimated to be 5.7% in the Japanese population. This polymorphism may be useful in genetic studies of Menkes disease.

Adenosine Triphosphatases↗