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Biomedical subjects

H Sakai

Publications and source records attributed to H Sakai.

At least 145 records · Page 8Linked to original sources
PubMed2001

Acid attack and cathepsin K in bone resorption around total hip replacement prosthesis.

Normal bone remodeling and pathological bone destruction have been considered to be osteoclast-driven. Osteoclasts are able to attach to bare bone surface and produce an acidic subcellular space. This leads to acid dissolution of hydroxyapatite, allowing cathepsin K to degrade the organic type I collagen-rich osteoid matrix under the acidic condition prevailing in Howship lacunae. Using a sting pH electrode, the interface membrane around a loosened total hip replacement prosthesis was found to be acidic. Confocal laser scanning disclosed irregular demineralization of the bone surface in contact with the acidic interface. Cathepsin K, an acidic collagenolytic enzyme, was found in interface tissue macrophages/giant cells and pseudosynovial fluid. Tissue extracts contained high levels of cathepsin K messenger RNA (mRNA) and protein. These observations suggest the presence of an acid- and cathepsin K-driven pathological mechanism of bone resorption, mediated not by osteoclasts in subosteoclastic space, but rather by the uncontrolled activity of macrophages in extracellular space.

Acids↗
PubMed2001

Vascular smooth muscle cell proliferation is effectively suppressed by the non-specific growth factor inhibitor suramin.

The purpose of this study was to investigate the effects of the non-specific growth factor inhibitor suramin on smooth muscle cell proliferation in vitro and in vivo. Cultured vascular smooth muscle cells (VSMC) were stimulated by platelet-derived growth factor (PDGF) and cellular DNA synthesis assessed by [3H]-thymidine uptake. Suramin dose-dependently inhibited DNA synthesis in VSMC, and 100 microM of suramin completely suppressed the PDGF-AB-induced cellular DNA synthesis. Rabbit carotid arteries were injured by the balloon catheter, and then suramin locally delivered using a porous balloon catheter over ten minutes. Three weeks after the vascular injury, the extent of intimal thickening was compared between the suramin-treated and control rabbits. The neointimal formation triggered by balloon-mediated vascular injury was suppressed significantly and dose-dependently by locally infused suramin, and the intima to media area ratios of the control and 1 mM suramin-treated animals were 48.8+/-14.9 and 12.2+/-6.0%, respectively (p < 0.01. n = 6 for each group). These results suggest that one time local administration of suramin was sufficient to suppress neointimal formation after balloon-mediated vascular injury, and that pharmacological intervention targeting the growth factor's signaling pathways could be a promising approach to prevent smooth muscle cell proliferation in various proliferative vascular diseases.

Animals↗
PubMed2001

Evaluation of renal biopsy samples of patients with diabetic nephropathy.

OBJECTIVE: To evaluate the usefulness of renal biopsy in the overall management of patients with diabetes mellitus (DM), we examined the relationship between the clinical parameters and histopathological findings of renal biopsy samples. METHODS: Renal biopsy specimens were obtained from 109 type 2 diabetic patients with proteinuria. Samples were divided into the following two groups: Diabetic Nephropathy (DN) group (n=80) had typical diabetic lesions without other renal diseases, complication group (n=29) had diabetic lesions with other renal diseases. Furthermore, DN group was subdivided into two subgroups: slow progressive group (SP group, n=32), the level of serum creatinine (s-Cr) was normal at the time of renal biopsy and three years after renal biopsy, and fast progressive group (FP group, n=14), the level of s-Cr was normal at the time of renal biopsy but more than doubled three years after renal biopsy. RESULTS: The level of total protein was significantly lower and HbA1c significantly higher in the DN group than in the Complication group. However, other clinical parameters were not significantly different between the two groups. Urinary protein, systolic and diastolic blood pressure in FP group were significantly higher than in SP group. The percentage of sclerotic glomeruli, the severity of mesangial expansion, tubular injury and cell infiltration were significantly greater in FP than in SP group. CONCLUSIONS: Our results indicated that a complete evaluation of renal pathology in DM could not be made by clinical parameters only, and that the progression of DN could be accurately predicted by histopathological evaluation. Therefore, this study emphasizes the importance of renal biopsy in the overall management of patients with DM and/or DN.

Adult↗
PubMed2001

Is rabbit CLCA1 related to the basolateral Ca2+ -dependent Cl- channel of gastric parietal cells?

An expression of mRNA coding the calcium-activated Cl- channel-1 (CLCA1) in rabbit gastric parietal cells was examined to verify the possibility that the CLCA1 mediates housekeeping Cl- channels in the basolateral membrane. In whole-cell voltage-clamp experiments of rabbit parietal cells, A23187 (2 microM), a Ca2+ ionophore, activated the basolateral Cl- channels. The partial cDNA fragment of rabbit CLCA1 could be amplified from the total RNA of tracheal epithelium. A Northern blot analysis showed that rabbit CLCA1 mRNA of 3.4 kb is highly expressed in the tracheal epithelium, but not in the gastric parietal cells. Even in a more sensitive detection of rabbit CLCA1 mRNA by RT-PCR, no signal could be observed in the gastric parietal cells. These results suggest that the CLCA1 protein may not be a subunit of the housekeeping Ca2+ -dependent Cl- channel in the basolateral membrane of rabbit gastric parietal cells.

Amino Acid Sequence↗
PubMed2001

[Estimation of daily dietary intake of aluminum].

The daily dietary intake of aluminum was estimated through a total diet study from 1996 to 1998. In ten institutes, total diet study samples were prepared and their aluminum concentration was determined. The average daily intake of aluminum was 3.5 mg and the range was 1.8-8.4 mg. The validity of the analytical result was supported by analyses of certified reference materials.

Aluminum↗
PubMed2001

The selenoorganic compound ebselen suppresses liver injury induced by Propionibacterium acnes and lipopolysaccharide in rats.

Ebselen (2-phenyl-1,2-benzoisoselenazol-3[2H]-one) is a selenoorganic compound containing selenium that has various pharmacological effects, including anti-inflammatory and antioxidant activity. Kupffer cells, residual hepatic macrophages, play an important role in the development of liver injury by producing free radicals and cytokines. The aim of this study is to evaluate whether ebselen suppresses macrophage-associated liver injury in rats. In vivo, we examined the effects of ebselen on liver injury, induced by Propionibacterium acnes and lipopolysaccharide (P. acnes-LPS), in rats where hepatic macrophages are considered to be primarily involved in injury development. Ebselen administration reduced the incidence of death following hepatic failure by P. acnes-LPS (82% vs. 20%, p<0.05). Serum levels of alanine aminotransferase, at 5 h after LPS administration, were significantly lower in the ebselen-treated group than in the control group (202.4+/-100.3 IU/l vs. 558.4+/-146.4 IU/l, p<0.05). Histological evidence of injury, such as necrosis, hemorrhage, and degeneration, was also suppressed by ebselen. Further, to assess the mechanisms involved, we investigated the production of cytokines and superoxide anions produced by activated hepatic macrophages in vivo. Serum levels of TNF alpha, interleukin-18 (IL-18)/IFN gamma-inducing factor (IGIF), and interferon gamma (IFN gamma) at 1 h after LPS administration were significantly lower in the ebselen-treated group. Formazan depositions, which were generated by the perfusion of the liver with nitroblue tetrazolium, were also observed less frequently in the ebselen treated group, suggesting a suppression in the release of superoxide anion from activated hepatic macrophages. In addition, we examined the effects of ebselen on cytokine production and mRNA expression, in vitro, using rat primary Kupffer cell culture. Ebselen also inhibited TNF alpha production and mRNA expression in vitro. These data imply that ebselen suppresses liver injury by inhibiting the production and/or release of proinflammatory cytokines and superoxide from activated hepatic macrophages. These data also suggest that ebselen is potent in the prevention of hepatic injury, such as endotoxemia, where hepatic macrophage activation has been implicated.

Alanine Transaminase↗
PubMed2001

Lingual calcinosis circumscripta in a captive sitatunga.

Calcinosis circumscripta (CC) was found in a 10-yr-old female sitatunga (Bovidae; Tragelaphus spekei). At necropsy, there were two white coalescing nodules (3 x 5 x 2 cm, 2 x 2 x 1.5 cm) on the ventral side of the tongue. The cut surface of the nodules had multiple, well-circumscribed loculi with chalky appearance and gritty consistency, separated by thin strands of connective tissue. Histologically, the nodules contained multiple loculi of various sizes and shapes, which consisted of amorphous material that was pale basophilic with H&E stain, surrounded by fibrous connective tissue. Around the loculi were numerous foreign body giant cells and epithelioid macrophages; occasional lymphocyte aggregations also were seen. The amorphous material was positive for PAS and von Kossa's stain. Calcinosis circumscripta is rare in the Bovidae.

Animals↗
PubMed2001

Malignant melanoma of the palpebral conjunctiva in a captive fallow deer.

A case of malignant melanoma in the conjunctiva of the eyelid of a captive 13-yr-old female fallow deer (Dama dama) was studied. The black tumor that protruded to the palpebral conjunctiva of the right lower eyelid consisted of an infiltrative growth of melanin-containing neoplastic cells with marked cytological atypia. The tumor involved the conjunctiva of the right lower eyelid and infiltrated to the conjunctival epithelial layer, but did not reach the palpebral skin. Numerous mitotic figures and lymphatic invasions were observed. This is a very rare case of a malignant melanoma arising from the palpebral conjunctiva in a wild ruminant.

Animals↗
PubMed2001

[Two cases of episodic angioedema associated with eosinophilia].

We experienced two cases of limb edema of unknown pathogenesis. No evidence was found concerning involvement of the kidneys, heart of other visceral organs. Case 1 was 22-year-old woman. Her white blood cell count increased to 13,100/microliter with 65.0% eosinophils. Case 2 was a 27-year-old woman. Her white blood cell count increased to 23,300/microliter with 67.0% eosinophils. In these cases, extensive diagnostic evaluations revealed no evidence of atopy, neoplasms, collagen-vascular disease, or parasitic infestation. We diagnosed these cases as episodic angioedema with eosinophilia. In both cases, the angioedema improved gradually in parallel with a decrease in the white blood cell count. This disorder is very rare, but it is very important to consider it in differential diagnosis especially for nephrologists.

Adult↗
PubMed2001

[Influence of age on serial change in TL/BMIPP dual isotope SPECT images after direct PTCA in patients with acute myocardial infarction].

The purpose of this study was to investigate the influence of age on serial change in 201TlCl (TL) and 123I-BMIPP (BMIPP) dual isotope single photon emission computed tomography (SPECT) images after direct PTCA in patients (pts) with acute myocardial infarction (MI). Dual SPECT with TL and BMIPP at rest, radionuclide ventriculography for left ventricular ejection fraction (LVEF), and two-dimensional echocardiography for wall motion analysis were performed in 26 pts at the subacute and chronic phases after direct PTCA for acute MI. A defect score (DS) for SPECT images was interpreted as normal: 0, mildly decreased: 1, moderately or severely decreased: 2, complete defect: 3. The difference in DS between TL and BMIPP was defined as the mismatch score (MS). DS in BMIPP was greater than that in TL at the subacute phase in all pts. Significant improvement in the wall motion score was recognized in pts who showed TL/BMIPP discrepancy at the subacute phase. Pts were classified by age into two groups; group I: younger than 65 years old (n = 18); group II: 65 years and older (n = 8). Improvement of MS from the subacute to chronic phase was significant in group I (5.2 +/- 1.9 to 3.2 +/- 1.9, p = 0.0001), whereas not significant in group II (6.2 +/- 2.9 to 6.1 +/- 2.9, NS). There was a significant negative correlation between relative MS (ratio of subacute MS to chronic MS) and age (r = -0.78, p < 0.0001). No significant correlation was observed between age and improvement in LVEF. These results indicate that disordered myocardial fatty acid metabolism, reflected by TL/BMIPP discrepancy, persist longer in elderly pts than younger pts after acute MI.

Adult↗
PubMed2001

[A case of malignant pheochromocytoma associated with von Recklinghausen's disease].

A 48-year-old woman suffering from chest and lumbar pain was referred to our clinic for treatment. She had a history of von Recklinghausen's disease with multiple café-au-lait spots and neurofibromatosis. Computed tomography demonstrated a large tumor in the left adrenal gland and a small lesion in the liver, with the levels of plasma and urinary catecholamines being elevated. 131I-metaiodobenzylguanidine (MIBG) scintigraphy showed abnormal accumulations in the left adrenal tumor and multiple-bone lesions. A diagnosis of malignant pheochromocytoma with liver and bone metastases was made, and the patient received chemotherapy. Seven months after the diagnosis of malignant pheochromocytoma, she died of pulmonary edema due to disease progression. Autopsy revealed malignant pheochromocytoma with liver, lung, bone and lymph nodes metastases. We reviewed the literature on pheochromocytoma associated with von Recklinghausen's disease. To our knowledge, only 7 cases of malignant pheochromocytoma associated with von Recklinghausen's disease have been reported in Japan.

Adrenal Gland Neoplasms↗
PubMed2001

[Anesthetic management of a child with Klippel-Feil syndrome associated with severe scoliosis].

We experienced an anesthetic management of a female child with Klippel-Feil syndrome complicated with severe scoliosis. This patient showed airway problems in anesthetic management because of limited neck movement due to fused cervical supine and winding airway due to scoliosis. A laryngeal mask (LM) was useful for ventilation but we fitted LM carefully because of her orolaryngeal anomaly. Intubation was very difficult through LM because the axis of LM was not on the laryngeal axis and the tip of the tracheal tube caught the epiglottis and arytenoid cartilage.

Anesthesia, General↗
PubMed2001

[Bilateral carotid stenting for radiation-induced arterial stenosis].

We report a case of bilateral radiation-induced internal carotid artery (ICA) stenosis treated with stenting. A 67-year-old man experienced transient left hemiparesis several times, and it was diagnosed as a bilateral ICA stenosis by magnetic resonance angiogram (MRA) and cervical ultrasound sonogram (US). Ten years before, the patient had received radiation therapy (66 Gy) and radical resection for a squamous cell carcinoma (SCC) in the right infrapharyngeal space. A cerebral angiogram showed bilateral severe ICA stenosis (right; 90%, left; 99%). We diagnosed this as radiation-induced ICA stenosis, and performed carotid angioplasty with a self-expanding stent. The post-operative course was uneventful and the patient was discharged without neurological deficits. Carotid endarterectomy (CEA) is difficult in the case of carotid artery stenosis due to radiation-induced arterial injury. Carotid stenting may be an alternative treatment for such a patient.

Aged↗
PubMed2001

Detection of differentially expressed genes in the early developmental stage of the mouse mandible.

We previously examined the development of the mouse mandible, and demonstrated that odontogenesis occurs between embryonic day 10.5 (E10.5) and E12. Based on the histological findings, we performed cDNA subtraction between the E10.5 and E12 mandibles to detect any differentially expressed genes which might be involved in the initiation of odontogenesis. By sequencing, homology search and semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR), we thus found Pgk-1, Ccte, Hsp86, Nucleolin, Hsc73, Frg1, N-ras, Set alpha and Hsj2 from the E10.5 mandible, and E25, ATPase6, Mum2, Thymosin beta4 and L21 from the E12 mandible to be differentially expressed genes. These genes are functionally related to protein transport, signal transduction, transcription, translation and molecular chaperon activity. In situ hybridization analyses of Set alpha and E25 showed that Set alpha was detected in the tooth germ at E12 and E14.5, thus indicating a close relationship of this gene to odontogenesis. Meanwhile, the in situ signal of E25 was found in the muscular layer of the tongue, thus suggesting E25 to be related to the differentiation of muscular tissue. In conclusion, we found 15 differentially expressed genes in the course of the early developmental stage of the mouse mandible using a combination of the cDNA subtraction and semi-quantitative RT-PCR methods, while in addition, two genes were demonstrated to be related to the initiation and the development of both tooth germ and the tongue according to the in situ hybridization technique.

Animals↗
PubMed2001

[A case of antiphospholipid antibody syndrome with variable renal histological change despite of poor changes in urinalysis].

We experienced a case of lupus nephritis with antiphospholipid antibody syndrome. A renal biopsy specimen from this patient showed various renal histological changes, but the results of urinalysis were almost normal. The patient was a 56-year-old woman diagnosed as having systemic lupus erythematosus with antiphospholipid antibody syndrome in 1983. In 1998, she had diarrhea and blood gas analysis showed metabolic acidosis. Therefore, she was admitted to our hospital and underwent renal function examination. The glomerular filtration rate was reduced(GFR: 40/ml/min), but urinalysis was almost normal. To examine her renal dysfunction, we performed open renal biopsy. Her renal tissues showed global glomerular sclerosis, mesangial cell proliferation and infiltration of cells in the tubulointerstitial area(WHO II). Furthermore, some arterioles showed organized thrombus formation and recanalization due to the antiphospholipid antibody syndrome. Renal biopsy of patients with lupus nephritis is useful not only for precise diagnosis, but also for the selection of appropriate treatment.

Antiphospholipid Syndrome↗
PubMed2001

[Stenting for proximal subclavian and brachiocephalic artery occlusion--preliminary results].

The authors report the initial results, between January 1998 and February 2001, of stenting utilizing the brachial approach in seven patients for total occlusions at the following locations: two right subclavian, one brachiocephalic, and five left subclavian arteries. All lesions were associated with subclavian steal syndrome. Indications for the treatment included ischemic symptoms in the affected arm (seven patients), and vertebrobasilar insufficiency (five patients). A total of eight stents were implanted in six occluded arteries, resulting in a 75% procedural success rate. Procedural complications encountered were two subintimal dissections by a 0.035-inch guide wire during recanalization, and one stent dislodgement with migration. There was no stroke, presumably because of the previously reported preventive effect of delayed reversal of a stealing vertebral artery. Follow-up over a mean duration of 11 months revealed no sign or symptom of recurrence in cases with initial technical success. The results of the current study, with a literature survey, indicated that percutaneous transluminal angioplasty with primary stent deployment in an occluded prevertebral segment of the subclavian or the brachiocephalic artery should be considered as an available choice for treatment. Further points, such as some remaining technical and clinical problems, will require more experience and consideration.

Adult↗
PubMed2001

Immunolocalization of cytokines and growth factors in subacromial bursa of rotator cuff tear patients.

Inflammation in the subacromial bursa causes pain in patients suffering from rotator cuff tear, with this long-lasting inflammation leading to fibrosis and thickening of the subacromial bursa. Both inflammatory cytokines and mechanical stress, and impingement in the subacromial space, might induce and worsen this inflammation. However, little is known of the mechanism of this inflammation. In this study, we used immunohistological staining to demonstrate the expression of Interleukin-1 beta (IL-1 beta), Tumor necrosis factor alpha (TNF-alpha), transforming growth factor beta (TGF-beta), and basic fibroblast growth factor (bFGF) in subacromial bursa derived from the patients suffering from rotator cuff tear. On the other hand the expression of these inflammatory cytokines and growth factors were little detected only to a small degree in patients with anterior shoulder instability who did not have severe shoulder pain and impingement in the subacromial space. Our findings suggest that those inflammatory cytokines and growth factors may play an important role in inflammation of the subacromial bursa. Controlling the expression of these cytokines and growth factors might be important for treating patients suffering from shoulder pain due to rotator cuff tear.

Acromion↗