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Biomedical subjects

Y Imamura

Publications and source records attributed to Y Imamura.

At least 217 records · Page 12Linked to original sources
PubMed1993

Mucin-producing pancreatic tumors: a study of nuclear DNA content by flow cytometry.

Nuclear DNA content in eight surgically resected mucin-producing pancreatic tumors (MPPT) consisting of two mucinous intraductal adenocarcinomas (MIDAC), two mucinous intraductal adenomas (MIDA), one mucinous cyst-adenocarcinoma (MCAC), and three mucinous cystadenomas (MCA) were measured by flow cytometry using paraffin-embedded tissue samples. The technique of Shutte was used for the preparation of paraffin-embedded tissue into single dissociated nuclei, while the method of Vindelov was used for staining the isolated nuclei with propidium iodine. Clinicopathologically, the four patients with MIDAC or MIDA were all male and had cystic lesions with a dilated pancreatic duct at the head of the pancreas, while the four patients with MCAC or MCA were all females and had cystic tumors at either the body or tail of the pancreas. All eight patients with MPPT had no metastasis to the regional lymph nodes and were all still alive without recurrence. In an analysis of nuclear DNA content, seven of eight patients had DNA diploid tumors while one patient with a MIDAC perforating the duodenum and choledochus had a DNA aneuploid tumor. Thus, these findings suggest that DNA diploid patterns in MPPT might be associated with a favorable prognosis in MPPT although some patients whose MPPT invaded the surrounding organs might have DNA aneuploid tumors.

Adenocarcinoma, Mucinous↗
PubMed1993

Determination of cysteamine and cystamine by gas chromatography with flame photometric detection.

A gas chromatographic method for the determination of cysteamine and its disulphide cystamine is described. Cysteamine and cystamine are converted into N,S-diisobutoxycarbonyl and N,N-diisobutoxycarbonyl derivatives, respectively. The derivatives are analysed by gas chromatography with flame photometric detection, using a DB-210 capillary column. The calibration curves for cysteamine and cystamine in the range of 0.2-5.0 nmol are linear and sufficiently reproducible for quantitative analysis, and the detection limit is about 0.5 pmol injected. Cysteamine in mouse tissues is found in the free reduced, free oxidized and protein-bound forms. Free oxidized and protein-bound forms are reduced to free cysteamine by the use of sodium borohydride, and then derivatized. Cysteamine and cystamine in mouse tissues can be measured without any interference from coexisting substances by this method. The recoveries of cysteamine and cystamine added to the tissue samples are 91-106%, and their reproducibilities are found to be satisfactory. Analytical results for the determination of various forms of cysteamine in mouse tissues are presented.

Animals↗
PubMed1993

Multiple agminated juvenile melanoma arising on a hyperpigmented macule.

A case of multiple agminated juvenile melanoma (MAJM) arising on a hyperpigmented macule is reported. The patient, a 1-year-old boy, had 9 small nodules on an irregular, hyperpigmented macule on the right shoulder. Histologically, the nodules contained nests of spindle-shaped cells in their epidermis and at the dermoepidermal junction, and the hyperpigmented macule exhibited increased melanin granules in the basal layer and small nests of epithelioid cells. We concluded that MAJM on a hyperpigmented macule is the subtype of the nevus spilus.

Humans↗
PubMed1993

Effects of rHuEPO therapy on exercise capacity in hemodialysis patients with coronary artery disease.

We investigated the effects of recombinant human erythropoietin (rHuEPO) therapy on exercise capacity by symptom-limited maximal treadmill exercise testing in 9 patients with coronary artery disease who were receiving maintenance hemodialysis. The initial hemoglobin concentration of 7.9 +/- 0.7 g/dl, (mean +/- S.D.) rose to 10.4 +/- 1.1 g/dl, (p < 0.01) after three months of rHuEPO therapy. The partial correction of renal anemia resulted in a significant increase in exercise duration (from 278 +/- 84 sec to 384 +/- 74 sec, p < 0.01) and maximum pressure-rate product (from 228.3 +/- 50.3 mmHg.bpm/10(2) to 262.8 +/- 40.4 mmHg.bpm/10(2), p < 0.01). The maximum exercise-induced ST segment depression significantly decreased after treatment (from 1.3 +/- 0.5 mm to 0.5 +/- 0.5 mm, p < 0.05). These results suggest that the improvement in maximum coronary oxygen supply exceeded the increased maximum myocardial oxygen requirements after the partial correction of renal anemia by rHuEPO therapy in hemodialysis patients with coronary artery disease.

Adult↗
PubMed1993

[Long-term culture of human mucosal microvascular endothelial cells and angiogenesis in vitro].

Human mucosal microvascular endothelial cells (HMMECs) were isolated and cultured from nasal inferior turbinates. These cells can be maintained for up to 30 passages over 10 months, as long as human umbilical vein endothelial cells (HUVECs), using dish-coated collagen and MCDB 107 medium supplemented with 10% fetal bovine serum and 75 micrograms/ml of crude endothelial cell growth factor prepared from bovine brain. These cells readily formed capillary-like structures when cultivated on dish-coated collagen or collagen gels as compared with HUVECs. The collagenase activities of conditioned medium from HMMEC culture on collagen gels were considerably higher in tumor conditioned medium while those from HUVECs were undetectable. The capillary-like structure in the collagen gel and the collagenase activities of conditioned medium were periodically changed during long-term cultivation of HMMECs. A good correlation between the two was observed. These results, suggest that there are phenotypic differences between HMMECs and HUVECs and that collagenase plays an important role in angiogenesis. These cultured HMMECs could serve as a valuable experimental model for determining mucosal pathogenesis in the nasal and paranasal sinus regions.

Adolescent↗
PubMed1993

Differential immunohistochemical staining of cancerous cells with anti-single-stranded DNA antiserum in ordinary pathological paraffin section after DNA-denaturation by acid hydrolysis.

Based on the finding that the nuclear DNA of cancerous cells is much more unstable than that of non-cancerous cells, yielding a larger amount of single-stranded DNA by acid hydrolysis, we developed a new method of cancer cell detection in ordinary pathological sections by immunohistochemical staining with anti-single-stranded DNA antiserum after acid hydrolysis. Methylated bovine serum albumin was conjugated with heat-denatured calf thymus DNA and used as the antigen of single-stranded DNA, and white male rabbits were immunized with the antigen to obtain the polyclonal antiserum. Ordinary paraffin-embedded sections were prepared from the formalin-fixed biopsy specimens taken from 482 malignant tumors and 73 benign tumors of human epithelial and non-epithelial origins. Additional 82 biopsy specimens of borderline malignancy were also examined. The sections were immunohistochemically stained with the antiserum after RNase digestion and DNA denaturation by hydrolysis with 2 N HCl at 30 degrees C. The acid hydrolysis for 20-30 min was optimum for the specimens fixed with 10% buffered formalin at room temperature for 16-24 hrs, and all cancerous cells were specifically stained positive, in sharp contrast to the negative stainability of all non-cancerous cells including inflammatory cells. This new method gives us decisive help in making diagnosis of malignancy in daily pathological examination. The possibility of malignancy of borderline lesion was discussed.

Animals↗
PubMed1993

Fluorescent staining of nucleolar organizer regions for three-dimensional display by confocal laser scanning microscope.

A new method of fluorescent staining of nucleolar organizer regions (F1NORs) is described. Aluminum ammonium sulfate was used instead of silver as the cationic metal ion for binding with NORs-associated proteins, and fluorescent morin was successively bound to aluminum by chelating with modification of the method developed by Malinin (1978). After bleaching the fluorescent staining of NORs by washing water, ordinary AgNORs staining was performed on the same section, and both images of F1NORs and AgNORs were found to coincide with each other. F1NORs staining of human malignant and benign tumors, and colorectal adenomas of borderline malignancy were examined by three-dimensional analysis of the fluorescence images under confocal laser scanning microscope (CLSM). A remarkable increase of F1NORs was found, not only in number but also in volume, with bizarre configuration in the process of tumor progression, and the F1NORs-CLSM technique may be helpful for daily pathological diagnosis of malignancy.

Evaluation Studies as Topic↗
PubMed1993

Early progression stage of malignancy of human colon border-line adenoma as revealed by immunohistochemical demonstration of increased DNA-instability.

The degree of DNA-instability was used as the marker of malignancy and applied to adenoma (7 benign cases and 17 border-line cases) and cancer (8 carcinoma-in-adenoma cases and 17 invasive cancer cases) of human colon. Proliferative activity by PCNA index and the activity of protein synthesis by AgNORs were also estimated for all cases as the supporting markers of malignancy. In all border-line cases, the following findings were obtained: (1), the degree of DNA-instability as revealed by immunohistochemical staining with anti-single-stranded DNA antiserum after acid hydrolysis was increased in border-line adenoma to the level of invasive overt cancer, indicating its malignancy with marked DNA-instability; (2), reflecting the malignant character, abnormal mitosis and single cell necrosis were usually observed in all border-line adenomas by fluorescent Feulgen staining, indicating the DNA alterations; (3), not only the parenchymal but also the stromal PCNA indices were statistically larger in border-line adenoma than in benign adenoma, indicating the "stromal activation" in malignancy; (4), the volumes of AgNORs were much increased in border-line adenoma in comparison with those in benign adenoma, and these showed further increases with the progression of malignancy to the invasive overt cancer. These findings indicate that border-line adenoma of human colon has already malignant character at the early progression stage, although no apparent epithelial atypia, or destructive invasion, is taking place.

Adenoma↗
PubMed1993

[Evaluation of left ventricular systolic function by pulsed Doppler echocardiography in patients with acute myocardial infarction].

Left ventricular systolic function in patients with acute myocardial infarction was assessed by Doppler echocardiographic measurement of left ventricular ejection flow velocity and maximum acceleration in 20 patients with initial acute anteroseptal myocardial infarction (group A) and 15 age-matched normal subjects. All patients underwent emergency reperfusion therapy by direct percutaneous transluminal coronary angioplasty (direct PTCA). Pulsed Doppler echocardiograms were obtained from sample volume immediately below the aortic valve in the apical long-axis view. Three parameters, peak velocity, ratio of acceleration time to ejection time (AT/ET) and maximum acceleration, were measured by the Doppler analysis program. Changes in the 3 parameters from the day of admission to the 3rd post-admission day were also observed in 15 patients. Although no significant difference was observed in AT/ET in the 2 groups, peak velocity and maximum acceleration in the patient group were significantly lower than those in the normal group (peak velocity: 90.8 +/- 13.1 vs 99.4 +/- 9.7 cm/sec, p < 0.05, maximum acceleration: 2,692.4 +/- 604.5 vs 3,410.2 +/- 712.5 cm/sec2, p < 0.01, respectively). Between the admission and 3rd day, peak velocity and AT/ET did not change significantly, but maximum acceleration increased significantly (2,720.5 +/- 676.7, 1st day vs 3,313.9 +/- 947.5 cm/sec2, 3rd day, p < 0.05). These results indicate that the maximum acceleration measured by pulsed Doppler echocardiography is useful for assessing global left ventricular systolic function in acute myocardial infarction. Direct PTCA results in improved ventricular systolic function on the 3rd post-operative day.

Adult↗
PubMed1993

Changes in free and bound alcohol metabolites in the urine during ethanol oxidation.

Free and bound ethanol, acetaldehyde, acetate, acetone and methanol in urine during alcohol oxidation were analyzed by means of a head space gas chromatography. Four healthy male volunteers drank beer for 20 min with 16 ml/kg for non-flushers (A, B) and 8 ml/kg for flushers (C, D). In the urine, the highest bound ethanol levels were between 0.5-1.1 mM for the non-flushers (NF) and 0.2-0.3 mM for the flushers (F). The urine free ethanol levels were 23-70 times as high as bound ethanol levels. The maximum free acetaldehyde in urine was 11-13 microM for the NF and 26-55 microM for the F. The urine bound acetaldehyde levels were 4-5 microM for the NF and 7-15 microM for the F. Urine acetaldehyde existed in free forms at 2.4-3.6 times as high concentrations as in bound forms during ethanol oxidation. The urine free acetate ranged between 0.3-2.0 mM. The bound acetate varied between 0.7-1.1 mM. The urine free methanol at 70-110 microM before the intake increased to 104-180 microM. The bound methanol reached to 78-126 microM from 48-97 microM before the intake. Ethanol levels in the urine were ethanol dose-dependent, whereas it was thought that free and bound acetaldehyde or acetate reflected individual metabolic abilities and not the amount of ethanol consumed.

Acetaldehyde↗
PubMed1993

Chemical modification of histidine residue in substrate-binding domain of carbonyl reductase from rabbit kidney.

Carbonyl reductase from rabbit kidney was rapidly inactivated by diethylpyrocarbonate (DEPC). A similar inactivation was observed in photooxidation of the enzyme by methylene blue. The inactivation by DEPC was time- and concentration-dependent and followed pseudo-first-order kinetics. The results obtained from the inactivation kinetics and the protective effect of 4-acetylpyridine (4-AP) with NADP+ against the inactivation led to the idea that one essential amino acid is located in substrate-binding domain of the enzyme. The treatment of the enzyme with DEPC formed N-carbethoxyhistidine. Judging from the effect of 4-AP with NADP+ on the formation of N-carbethoxyhistidine, it is concluded that one histidine residue is located in substrate-binding domain of the enzyme. Furthermore, whether one essential amino acid inactivated by DEPC corresponds to one histidine residue modified with DEPC is discussed.

Alcohol Oxidoreductases↗
PubMed1993

Postnatal development and sex-related difference of metyrapone reductase activities in liver microsomes and cytosol of the rat.

A significant difference was observed between developmental patterns of metyrapone reductase activities in liver microsomes of male and female rats. The activity in liver microsomes of male rats was maintained at high levels until ten weeks of age after birth. In contrast, the activity in liver microsomes of female rats was markedly decreased until six weeks of age and reached low levels after eight weeks of age. As with the results of such different patterns, there were pronounced sex-related differences during adult period. Castration significantly decreased the activity in liver microsomes of male rats. This finding suggests that androgens have a role in sex-related differences of the activities in liver microsomes of male and female rats. Furthermore, sex-related differences of the activities were examined in microsomes and cytosol from the liver and kidney of the rat, mouse, hamster, guinea pig, and rabbit. All animal species tested showed sex-related differences in their activities. The rat and rabbit were found to resemble the guinea pig and hamster, respectively, in the occurrence of sex-related difference.

Alcohol Oxidoreductases↗
PubMed1993

Sex-related differences of acetohexamide reductase activities in the liver and kidney of various mammalian species.

Sex-related differences of acetohexamide reductase activities in cytosol and microsomes from the liver and kidney of the rat, mouse, guinea pig, hamster and rabbit were examined. Among animal species tested, the rat, guinea pig and rabbit exhibited sex-related differences in the activities. The activities in liver cytosol of the rat and rabbit were higher in the females than in the males, whereas the activity in kidney cytosol of the rabbit was higher in the male than in the female. Furthermore, the activities in liver and kidney microsomes of the rat and that in kidney microsomes of the guinea pig were much higher in the males than in the females. It is interesting to note that significant sex-related differences of acetohexamide reductase activities are found in some animal species other than the rat.

Alcohol Oxidoreductases↗
PubMed1993

[Risk factors for coronary artery disease in Japanese patients with chronic renal failure].

We examined the records of 101 Japanese patients with chronic renal failure (CRF) to determine the influence of established risk factors on the incidence of coronary artery disease (CAD). CAD was found in 25 patients (myocardial infarction in 18, significant coronary artery stenosis by coronary angiogram in 16). In patients with CAD, there were significantly more male (80% vs 58%, p < 0.05), more smokers (80% vs 41%, p < 0.0005), more diabetics (68% vs 32%, p < 0.005) and more hypertensives (92% vs 76%, p < 0.05). However, lipoprotein (a), high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, or triglycerides were not significantly different between CAD group and control group. When significant risk factors were entered into a stepwise logistic regression analysis, we found a history of smoking (p = 0.0025) and the presence of diabetes (p = 0.0141) to be independent risk factors for the presence of CAD in Japanese patients with CRF.

Adult↗
PubMed1993

[Usefulness of polymerase chain reaction (PCR) technique in making early diagnosis and treatment of cytomegalovirus and Pneumocystis carinii-pneumonia in patients with hematological neoplasms].

Recently, the incidence of opportunistic infections in patients with hematological neoplasms has been markedly increasing. However, early and definitive diagnosis and treatment of these infections remain difficult. In this study, we report three patients, a 47-year-old female with ATL, a 54-year-old female with CML and a 65-year-old female with ATL. All these cases were complicated with pneumonia caused by Pneumocystis carinii (Pc) or cytomegalovirus (CMV). They were successfully treated with sulfamethoxazole/trimethoprim or ganciclovir after detection of the respective microorganisms from sputum samples in the early stage of the infections by polymerase chain reaction (PCR) method. The above clinical evidence demonstrated the PCR technique to be a rapid and sensitive diagnostic procedure for the detection of Pc or CMV and to be helpful for the early initiation of appropriate treatment of the infections in patients with hematological neoplasms.

Aged↗
PubMed1993

Postnatal development, sex-related difference and hormonal regulation of acetohexamide reductase activities in rat liver and kidney.

A variety of patterns of postnatal development were observed for acetohexamide reductase activities in microsomes and cytosols from the liver and kidney of male and female rats. Furthermore, there were pronounced sex-related differences in the activities of liver and kidney microsomes. Prepubertal and neonatal testectomies decreased markedly the activities in liver and kidney microsomes of adult male rats to the female levels. The activities in liver and kidney microsomes decreased by prepubertal testectomy and the activity in kidney microsomes decreased by neonatal testectomy were restored to control levels by testosterone propionate treatment, whereas the activity in liver microsomes decreased by neonatal testectomy was unaffected by the same treatment. Prepubertal or neonatal testectomy had no effect on the activity in liver or kidney cytosol of adult male rats. Prepubertal ovariectomy decreased the activities in liver and kidney cytosols of adult female rats and the decreased activities were restored to control levels by estradiol benzoate treatment. Based on these results, we propose that the postnatal development and sex-related difference of acetohexamide reductase activities in rat liver and kidney can be regulated by sex hormones such as testosterone propionate and estradiol benzoate.

Alcohol Oxidoreductases↗
PubMed1992

The upstream region of the mouse N-myc gene: identification of an enhancer element that functions preferentially in neuroblastoma IMR32 cells.

The various members of the myc gene family, including c-myc and N-myc, are supposed to play a role in the regulation of cell cycle and proliferation. Whereas c-myc is expressed nearly ubiquitously, the N-myc gene product is found mainly in actively proliferating neural tissues such as early development tissues or in retinoblastomas and neuroblastomas. In this report, the upstream region of mouse N-myc gene was ligated to pSVPCAT, which carries the simian virus 40 (SV40) promoter and bacterial chloramphenicol acetyltransferase (CAT) gene, and transcriptional activities were examined by CAT and S1 protection assays after transfection of the DNAs into human cervical carcinoma HeLa or neuroblastoma IMR32 cells. Several regulatory regions were identified: two promoting regions (-980 to -860 and -279 to +108) and an inhibiting one (-860 to -797). The region spanning positions -980 to -860 increased CAT expression independently of orientation and distance to the SV40 promoter, indicating that the element is a typical enhancer. Moreover, the expression levels from this enhancer were higher in IMR32 cells than in HeLa cells, indicating that action has, if not cell-type specificity, cell-type preference. These findings may provide useful bases for the understanding of the cell-type specific regulation of N-myc expression.

Animals↗