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Biomedical subjects

K Imai

Publications and source records attributed to K Imai.

At least 253 records · Page 14Linked to original sources
PubMed2000

Three different types of congenital lacrimal sac fistulas.

Three different symptoms in 4 patients with congenital lacrimal sac fistulas are presented. The first symptom was epiphora since birth, the second symptom was infection of the lower eyelid, and the third symptom was tearing from the eye in a 76-year-old patient. This patient had nasolacrimal obstruction at the canal level and no symptoms of congenital lacrimal sac fistula. She had undergone excision, including dacryocystorhinostomy. Three of the 4 patients underwent excision of the fistulous tract. The fistula originated from the lacrimal sac in all patients. Symptomatic congenital lacrimal sac fistulas can be treated successfully with excision alone or with excision and dacryocystorhinostomy in cases of nasolacrimal obstruction.

Aged↗
PubMed2000

An evaluation of hard palate mucosa graft as a lining material in alar reconstruction: a 7-year experience applied to the full-thickness alar defect.

The authors present their experience with 25 hard palate mucosa grafts used as lining material in the reconstruction of full-thickness alar defects. Good "take" was obtained in 22 grafts; the other three grafts incurred necrosis of the overriding skin flaps and postoperative infection. Degree of shrinkage was 11 to 15 percent of grafted size in patients with the type of defect that did not include the alar margin; shrinkage was 26 to 35 percent in patients with the type that included more than 50 percent of the alar margin. In all patients who had a good graft take, the nasal cavities were maintained and there was no nasal obstruction or collapsing during strong breathing. The healing time of the palate donor site varied from 7 days to 5 weeks, depending on the size of the defect. No patients experienced any symptoms at the donor site after healing. The authors concluded that hard palate mucosa can be considered a useful material in alar reconstruction because of the ease in graft harvesting and its support features. When the defect is large enough to involve the total unilateral ala nasi, even though the degree of postoperative shrinkage is comparatively high, hard palate mucosa may be the most suitable material to ensure good take of the graft and less possibility of donor-site morbidity.

Adult↗
PubMed2000

Transforming growth factor-beta inhibits lipopolysaccharide-stimulated expression of inflammatory cytokines in mouse macrophages through downregulation of activation protein 1 and CD14 receptor expression.

The septic shock that occurs in gram-negative infections is caused by a cascade of inflammatory cytokines. Several studies showed that transforming growth factor-beta1 (TGF-beta1) inhibits this septic shock through suppression of expression of the lipopolysaccharide (LPS)-induced inflammatory cytokines. In this study, we investigated whether TGF-beta1 inhibition of LPS-induced expression of inflammatory cytokines in the septic shock results from downregulation of LPS-stimulated expression of CD14, an LPS receptor. TGF-beta1 markedly inhibited LPS stimulation of CD14 mRNA and protein levels in mouse macrophages. LPS-stimulated expression of CD14 was dramatically inhibited by addition of antisense, but not sense, c-fos and c-jun oligonucleotides. Since TGF-beta1 pretreatment inhibited LPS-stimulated expression of c-fos and c-jun genes and also the binding of nuclear proteins to the consensus sequence of the binding site for activation protein 1 (AP-1), a heterodimer of c-Fos and c-Jun, in the cells, TGF-beta1 inhibition of CD14 expression may be a consequence of downregulation of AP-1. LPS-stimulated expression of interleukin-1beta and tumor necrosis factor alpha genes in the cells was inhibited by addition of CD14 antisense oligonucleotide. Also, TGF-beta1 inhibited the LPS-stimulated production of both inflammatory cytokines by the macrophages. In addition, TGF-beta1 inhibited expression of the two cytokines in several organs of mice receiving LPS. Thus, our results suggest that TGF-beta1 inhibition of LPS-stimulated inflammatory responses resulted from downregulation of CD14 and also may be a possible mechanism of TGF-beta1 inhibition of LPS-induced septic shock.

Animals↗
PubMed2000

Microsatellite instability in patients with multiple primary cancers of the gastrointestinal tract.

BACKGROUND: Little is known about the genetic alterations in multiple primary cancers of the gastrointestinal tract. Microsatellite instability (MSI) is frequently observed in hereditary non-polyposis colorectal cancer (HNPCC), and multiple primary cancers is a feature of this syndrome. AIMS: To identify MSI incidence, target gene mutation, and mismatch repair (MMR) protein status in patients with multiple primary cancers of the gastrointestinal tract. SUBJECTS: Fifty seven cancers from 22 Japanese patients with multiple primary cancers of the stomach, duodenum, colon, and rectum. METHODS: MSI was examined at 5-7 microsatellite loci. Mutation analysis for TGFbetaRII, IGFIIR, and BAX was performed in cancers with MSI. MMR protein status was examined by immunohistochemical analysis using a monoclonal antibody against hMSH2 and hMLH1. RESULTS: MSI was observed in 16 of 22 patients (73%) and in 29 of 57 lesions (51%). High frequency MSI (MSI-H) was found often in patients with multiple cancers in the same organ (p = 0.042), especially in multiple gastric cancer patients (p = 0.038). In contrast, patients with multiple cancers in different organs had a tendency to show low frequency MSI (MSI-L) or microsatellite stable (MSS) phenotype. Both target gene mutation and decreased expression of MMR protein were found only in seven lesions of three patients with MSI at more than four microsatellite loci. CONCLUSIONS: These results suggest that genetic instability may play an important role in the development of multiple gastrointestinal cancers but there may be different genetic alterations between multiple gastrointestinal cancers of the same and different organs.

Aged↗
PubMed2000

Isolation and characterization of a novel gene encoding a putative seven-span transmembrane protein, TM7SF3.

As part of a project involving large-scale sequencing of clones randomly selected from a human cDNA library, we isolated a novel human gene, termed TM7SF3 (transmembrane 7 superfamily member 3). Its open reading frame encodes a 570 amino acid protein containing seven putative transmembrane domains. The transcript of this gene was expressed in all human tissues examined, but most abundantlyin kidney. Immunocytochemical analysis demonstrated subcellular localization of TM7SF3 protein at the plasma membrane. We determined the chromosome location of TM7SF3 as 12q11.2-->q12 by a combination of fluorescence in situ hybridization and radiation hybrid mapping.

Amino Acid Motifs↗
PubMed2000

(beta)-catenin mediates the specification of endoderm cells in ascidian embryos.

In the present study, we addressed the role of (beta)-catenin in the specification of embryonic cells of the ascidians Ciona intestinalis and C. savignyi and obtained the following results: (1) During cleavages, (beta)-catenin accumulated in the nuclei of vegetal blastomeres, suggesting that it plays a role in the specification of endoderm. (2) Mis- and/or overexpression of (beta)-catenin induced the development of an endoderm-specific alkaline phosphatase (AP) in presumptive notochord cells and epidermis cells without affecting differentiation of primary lineage muscle cells. (3) Downregulation of (beta)-catenin induced by the overexpression of cadherin resulted in the suppression of endoderm cell differentiation. This suppression was compensated for by the differentiation of extra epidermis cells. (4) Specification of notochord cells did not take place in the absence of endoderm differentiation. Both the overexpression of (beta)-catenin in presumptive notochord cells and the downregulation of (beta)-catenin in presumptive endoderm cells led to the suppression of Brachyury gene expression, resulting in the failure of notochord specification. These results suggest that the accumulation of (beta)-catenin in the nuclei of endoderm progenitor cells is the first step in the process of ascidian endoderm specification.

Alkaline Phosphatase↗
PubMed2000

Adhesion between cells and extracellular matrix with special reference to hepatic stellate cell adhesion to three-dimensional collagen fibers.

Hepatic stellate cells are located in the perisinusoidal space (space of Disse), and extend their dendritic, thin membranous processes and fine fibrillar processes into this space. The stellate cells coexist with a three-dimensional extracellular matrix (ECM) in the perisinusoidal space. In turn the three-dimensional structure of the ECM regulates the proliferation, morphology, and functions of the stellate cell. In this review, the morphology of sites of adhesion between hepatic stellate cells and extracellular matrix is described. Hepatic stellate cells cultured in polystyrene dishes spread well, whereas the cells cultured on or in type I collagen gel become slender and elongate their long cellular processes which adhere directly to the collagen fibers. Cells in type I collagen gel form a large number of adhesive structures, each adhesive area forming a face but not a point. Adhesion molecules, integrins, for the ECM are localized on the cell surface. Elongation of the cellular processes occurs via integrin-binding to type I collagen fibers. The signal transduction mechanism, including protein and phosphatidylinositol phosphorylation, is critical to induce and sustain the cellular processes. Information on the three-dimensional structures of ECM is transmitted via three-dimensional adhesive structures containing the integrins.

Animals↗
PubMed2000

Production of LLU-alpha following an oral administration of gamma-tocotrienol or gamma-tocopherol to rats.

An oral administration of gamma-tocotrienol (gamma-T3) or gamma-tocopherol (gamma-Toc) to male rats caused an increase of the concentration of 2,7,8-trimethyl-2-(beta-carboxyethyl)-6-hydroxy chroman (LLU-alpha, gamma-CEHC), a natriuretic compound, in plasma with a T(max) of 9 h. The configuration at C-2 of LLU-alpha produced from gamma-T3 or gamma-Toc was assigned as S-form by an HPLC equipped with a chiral column. These data indicated that LLU-alpha was produced not only from gamma-Toc but also gamma-T3, without racemization at C-2 in rats.

Animals↗
PubMed2000

Alteration in membrane fluidity of rat liver microsomes and of liposomes by protoporphyrin and its anti-lipidperoxidative effect.

The effect of protoporphyrin (PP) on membrane fluidity was investigated by electron paramagnetic resonance spectroscopy using doxyl stearate spin probes in relation to the anti-lipidperoxidative effect of PP. PP decreased the membrane fluidity in rat liver microsomes at concentrations above 1 mM and also in phosphatidylcholine (PC)-cholesterol (Cho) (100:8, a molar basis) liposomes. The lipid peroxidation stimulated by Fe2+ and L-ascorbic acid in those membrane preparations was attenuated along with the decrease in membrane fluidity by PP. Similar results were also found in Cho-rich PC (100:30 to 100) liposomes having less fluidity. These results suggest that the decrease in the membrane fluidity caused by PP may be involved in the antioxidative action of PP.

Animals↗
PubMed2000

New approach for measurement of sympathetic nervous abnormality in conscious, spontaneously hypertensive rats.

We previously reported a highly sensitive chemiluminescence high-performance liquid chromatographic method to determine catecholamines in plasma. In this study, we employed this method to measure the cardiac function and plasma norepinephrine (NE) concentration in conscious rats. Benidipine, 1,4-dihydropyridine calcium antagonist (4 mg/kg), and beta-blocker (propranolol, 30 mg/kg) were administered orally to conscious spontaneously hypertensive rats (SHRs) and Wistar-Kyoto (WKY) rats, and blood pressure, heart rate and plasma NE levels were measured. Plasma NE concentration was used as an index of sympathetic nervous system activity in conscious rats. The basal plasma NE levels were significantly higher in SHRs than in WKY rats (P<0.05), indicating the activity of the basal sympathetic nervous system in SHRs was elevated. The sensitivity of the baroreflex-mediated sympathetic nervous response was reduced in SHRs as compared to that in WKY rats. The concomitant administration of benidipine and a beta-blocker decreased heart rate without affecting the baroreflex-mediated sympathetic nervous response, indicating that propranolol might suppress mainly the cardiac beta-adrenoceptor. The present study suggested the high activity of the basal sympathetic nervous system and the reduced response of the baroreflex-mediated sympathetic nervous system in SHRs compared to WKY rats in the conscious condition.

Animals↗
PubMed2000

Accumulated lipids, aberrant fatty acid composition and defective cholesterol ester hydrolase activity in cholesterol ester storage disease.

We confirmed accumulation of glycogen and lipids, particularly cholesterol esters, in the liver of a patient with cholesterol ester storage disease (CESD). Hepatic cholesterol ester concentration was 100-200 times that found in normal livers. Analysis of the fatty acid composition indicated a higher proportion (41%) of cholesterol linoleate (C18-2), a slightly lower proportion (33%) of cholesterol oleate (C18-1) and normal proportions (14%) of cholesterol palmitate (C16-0) in the CESD patient compared with the control. This fatty acid composition of cholesterol esters and the fatty acid composition of other classes of lipids in the patient's liver resembled that of LDL. We also found that acid cholesterol ester hydrolase activity in the CESD liver was reduced to 5% of that in the control liver, while neutral cholesterol ester hydrolase activity remained at the control level. These results suggest that accumulated cholesterol esters were derived mainly from serum LDL and that the accumulation resulted from lack of acid cholesterol ester hydrolase.

Child, Preschool↗
PubMed2000

Epidemiological studies of coincidental outbreaks of enterohemorrhagic Escherichia coli O157:H7 infection and infectious gastroenteritis in Niimi City.

A sharp rise in the number of patients with infectious gastroenteritis was observed in the 25th week of year 1996 in the Takahashi-Ashin district by researchers with the Infectious Disease Surveillance Program for tuberculosis and other infectious diseases in the Okayama Prefecture. This sharp rise occurred coincidentally with an outbreak of enterohemorrhagic Escherichia coli O157:H7 (EHEC O157) infection in Niimi City of the Takahashi-Ashin district. However, this phenomenon of coincidental outbreaks was not observed during the outbreak of EHEC O157 infection in Oku Cho. By reviewing outpatients' charts in a sentinel hospital in Niimi City for the Infectious Disease Surveillance Program, it was noted that patients with acute gastrointestinal infection visiting the hospital during the increased incidence of infectious gastroenteritis may have been included as misclassified cases of EHEC O157 infection. On the other hand, the exponential probability plotting of symptomatic patients with EHEC O157 infection in Niimi City revealed a breaking point which suggested a dual exposure to contaminated food or an overlap with other acute gastrointestinal infections. The latter possibility was discounted, because stool culture-positive patients with EHEC O157 infection also exhibited a similar breaking point, and furthermore, the coincidental increase in infectious gastroenteritis in the same area was attributable to the EHEC O157 infection. The present study demonstrates the association between the sharp rise in gastroenteritis and the outbreak of EHEC O157 in the Takahashi-Ashin district. A careful analysis of the cases of infectious gastroenteritis by the Infectious Disease Surveillance Program would have predicted the outbreak of EHEC O157.

Disease Outbreaks↗
PubMed2000

Effect of food restriction on hepatotoxicity of carbon tetrachloride in rats.

Five-week-old Sprague-Dawley rats of both sexes were assigned to two types of feeding condition. One was fed ad libitum (AL) on commercial chow and another was fed a restricted amount of the chow (FR), approximately 75% of that fed in the AL condition. In each feeding condition, animals were orally administered carbon tetrachloride (CCl4) at levels of 0 (control), 0.1 or 0.2 ml/kg 6 days a week for 8 weeks. Lesions of the liver (hepatic cellular degeneration and fibrosis) and of the kidney (proximal tubular vacuolation and glomerular sclerosis) induced by CCl4 were aggravated in the FR group. The FR-control showed a higher metabolic activity of aniline in the liver than the AL-control group. Plasma lipid-peroxide (LPO) level was higher in the AL-control group than in the FR-control group. With CCl4 0.2 ml/kg treatment, however, the plasma LPO level was reversed between the AL and the FR groups. Taking together these somewhat unexpected results, it was concluded that (1) 25% food restriction increases toxicity of repeatedly administered CCl4 in rats, and (2) aggravation of CCl4 toxicity may be partly due to enhanced metabolic activation of CCl4 resulting from food restriction.

Animals↗
PubMed2000

Bilateral simultaneous thalamic hemorrhages--case report.

A 54-year-old male presented with bilateral simultaneous thalamic hemorrhages manifesting as semicoma, tetraplegia, and skew deviation. Magnetic resonance imaging and angiography demonstrated no lesions responsible for the bleeding. Coagulant factors were within normal ranges. The cause of these hemorrhages was considered to be hypertension. Conservative treatment was performed. He was discharged with serious neurological deficits.

Cerebral Angiography↗
PubMed2000

[A case of aseptic osteomyelitis with heel ulcer improved by steroid application].

A 43-year-old male patient was admitted to our hospital because of left heel pain and fever. He had had swelling of the left ankle joint and pain 4 years prior to this, and 4 years later, he was admitted to another hospital when left heel ulcer and fever developed. The ulcer was diagnosed and treated as a diabetic ulcer because of hyperglycemia. In spite of good control of blood sugar, the ulcer became enlarged and the pain deteriorated, so he was transferred to orthopedics. Antibiotics produced no response, and culture from a specimen of the ulcer was negative. However, severe inflammatory response was seen in blood examination. MRI and scintigram of his left foot showed disseminated low intensity areas and accumulation in the tarsal bone area, so osteomyelitis was suspected. A biopsy of the ulcer showed infiltration of inflammatory cells into the dermis. We considered amputation of the left lower leg at first. However the biopsy result suggested an autoimmune mechanism, so prednisolone was administered. As a result, the ulcer and pain both diminished. This case was similar to pyoderma gangenosum, however this diagnosis cannot explain osteomyelitis or all its symptoms. We expect that there must be other case report with the same symptoms.

Adult↗
PubMed2000

[A male case of Sjögren's syndrome presenting with generalized lymphadenopathy and swelling of both lacrimal and salivary glands which responded remarkably well to an administration of corticosteroids].

A 68-year-old man noticed severe oral dryness and a submandibular swelling. Sjögren's syndrome (SS) was diagnosed based on microscopic findings of a labial salivary gland biopsy although both anti-SS-A and anti-SS-B antibodies were negative. In addition, hypergammaglobulinemia (IgG 7940 mg/dl) and hypocomplementemia were pointed out and he was admitted to our department. On admission cervical, mediastinal, and abdominal lymph nodes swelling were detected together with enlargement of lacrimal and salivary glands. Lymphoproliferative disorders associated with SS were highly suspected. Biopsied specimens of his lacrimal gland and cervical lymph node disclosed neither malignant cells nor monoclonal proliferation of lymphocytes. An administration of corticosteroids caused rapid diminution in size of lacrimal glands, salivary glands, and lymph nodes. Both lacrimation and salivation recovered, and hypergammaglobulinemia and hypocomplementemia returned to normal after treatment. The characteristics of this case were an atypical onset in an elderly man, the negativity of anti-SS-A and anti-SS-B antibodies, and reversibility of dryness by corticosteroid treatment. These findings suggest that the pathogenesis of this case may be different from typical SS.

Aged↗