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Biomedical subjects

H Natori

Publications and source records attributed to H Natori.

At least 19 recordsLinked to original sources
PubMed1997

[Digital filing system for medical image data].

To establish practical, effective medical digital image filing systems, various problems remain to be solved. The authors focused on 2 such problems of great importance: image data compression and standard specifications for digital data storage. From a variety of image compression algorithms now available, 2D-Color Doppler image compression was clinically investigated using the Joint Photographic Expert Group (JPEG) method. In low grade compression, the images decompressed showed no significant alterations in image quality, however, in higher grades of compression attained through irreversible coding in the JPEG method, the images showed subtle but significant alterations: emergence of 2 kinds of artifact, i.e., borderline-artifact produced in the DCT procedures and pseudo color spots. The reproducibility of colors was found to be altered by changing the quantization table in the JPEG procedure. It was thought necessary to choose a proper quantization table and examine the DC coefficients (number of pixels) in the DCT procedure to attain practical 2D-Color Doppler image compression by the JPEG method. Although attempts in Japan are being made to establish common standards for electronic data storage, based on MEDIS, in an effort to promote standardization there are many problems to be solved before practical use is possible. To ensure common availability as required by the technical standards, it is necessary to organize minimum-required specifications into common standards and make them open to the public.

Algorithms↗
PubMed1996

Disintegration of the 'waterfall phenomenon' in the inferior vena cava due to right heart failure.

The concept of the waterfall phenomenon in Zone 2 in the pulmonary vasculature is well known from West's lung model. It is believed that the flow through this zone is determined by the pressure difference between the pulmonary artery and alveoli, and the left atrial pressure is not transmissible to the alveolar capillaries. However, it is impossible to see whether alveolar capillaries are really displaying the waterfall phenomenon or not. In this review, the interrelation between the flow and geometry of the alveolar capillaries in the waterfall phenomenon is analyzed based on physiological studies using a model system and isolated lung lobe experiments. Further, extending the concept to the analysis of ventilatory changes of the inferior vena cava (IVC) configuration, it is ascertained that the waterfall phenomenon normally occurs in the IVC during inspiration just before it enters the thorax and the waterfall phenomenon in the IVC disintegrates with elevation of the central venous pressure. Because these configurations of the IVC in normal and abnormal conditions are visible with ultrasonography, the technique is very useful as a noninvasive approach to diagnose right heart failure.

Blood Flow Velocity↗
PubMed1996

[Clinical significance of soluble interleukin-2 receptor levels in the cerebrospinal fluid in patients with adult T-cell leukemia complicated with meningeal infiltration].

We measured soluble interleukin-2 receptor (sIL-2R) levels in the cerebrospinal fluid (CSF) of patients with hematological malignancies especially, adult T-cell leukemia (ATL) and non-Hodgkin's lymphoma (NHL) with or without meningeal infiltration. CSF levels of sIL-2R were significantly higher in patients with ATL and NHL with meningeal infiltration than in patients with both diseases without meningeal infiltration. The sIL-2R levels in CSF were elevated in 4/4 ATL patients (100%) and 3/13 NHL patients (23%) with meningeal infiltration. CSF levels of sIL-2R from ATL patients with meningeal infiltration had a tendency to elevate in correlation with numbers of mononuclear cells and lactic dehydrogenase (LDH) in CSF. However, these had no correlation with serum levels of sIL-2R. Therefore, sIL-2 levels in CSF may be useful in the diagnosis of meningeal infiltration in patients with ATL, are probably specific markers for meningeal infiltration of ATL.

Adolescent↗
PubMed1996

[Soluble interleukin-2 receptor and macrophage colony-stimulating factor (M-CSF) in cerebrospinal fluid in patients with hematological malignancies: clinical significance in adult T-cell leukemia with meningeal infiltration].

We measured soluble interleukin-2 receptor (sIL-2R) and macrophage colony-stimulating factor (M-CSF) levels in the cerebrospinal fluid (CSF) of patients with hematological malignancies with or without meningeal infiltration and meningitis. Levels of sIL-2R and M-CSF in the CSF of adult T-cell leukemia (ATL) patients with meningeal infiltration were significantly higher than those of ATL patients without meningeal infiltration and non-ATL patients with meningeal infiltration. There was a significant positive correlation between sIL-2R levels and numbers of mononuclear cells in CSF of ATL patients with meningeal infiltration. However, M-CSF levels did not correlate with numbers of mononuclear cells. There was no correlation between CSF and serum levels of sIL-2R. There was also no correlation between sIL-2R and M-CSF in the CSF. Therefore, sIL-2R and M-CSF levels in the CSF may be useful in the diagnosis of meningeal infiltration in patients with ATL. In particular sIL-2R may be a sensitive marker.

Biomarkers, Tumor↗
PubMed1996

[Anemia due to chronic lead poisoning].

We report a case of anemia due to chronic lead poisoning. A 46-year-old female was admitted to our hospital because of general fatigue and anemia. A peripheral blood smear showed basophilic stippling. There was basophilic stippling and nuclear dysplasia of erythroblasts in the bone marrow. Laboratory findings were as follows: RBC 296 X 10(4)/microliter, Hb 8.5 g/dl, blood lead concentration 67 micrograms/dl, urinary lead concentration 309 micrograms/l, blood delta-ALA dehydrase 0.03 mumol/ml, urinary delta-ALA 25.2 mg/l, urinary coproporphyrin 8,810 micrograms/g.Cr, and blood protoporphyrin 612 micrograms/dl. Chronic lead poisoning was diagnosed and she was treated with Ca-EDTA.

Anemia↗
PubMed1995

Expression of the MAGE gene family in human lymphocytic leukemia.

The MAGE gene family, encoding tumor-rejection antigens recognized by cytotoxic T lymphocytes, is frequently expressed in human solid cancers. However, its expression in leukemia has not been well studied. We have investigated MAGE gene expression at the mRNA level in human leukemia. The MAGE gene family was expressed in 17 of 34 (50%) examples of T cell leukemia (12/21 patients' peripheral blood mononuclear cells and 5/13 cell lines), in 7 of 16 (44%) cases of B cell leukemia (1/8 and 6/8 respectively), but in none of 23 myelomonocytic leukemia cases (0/16 and 0/7), as evaluated by the primers common to the MAGE-1, -3, -4 (-4a and/or -4b), and -6 genes and the semi-quantificative reverse transcription/polymerase chain reaction method. None of a panel of normal lymphoid cells expressed the MAGE gene family. As revealed by the primers specific for each of the MAGE genes, the MAGE-1, -2, -3, -4 or -6 gene was expressed in 8, 8, 6, 2, or 6 respectively out of 23 types of leukemia cell lines. Expression of the MAGE-1 protein in both the cell lines and patients' cells was confirmed by immunoblot analysis with the polyclonal antibody to recombinant MAGE-1 protein. Cellular MAGE-4 protein in the cell lines was measured by an enzyme-linked immunosorbent assay with the polyclonal and monoclonal antibodies to recombinant MAGE-4b protein. In summary, the MAGE gene family was found to be expressed in the substantial proportion of T cell leukemias, but in no case of myelomonocytic leukemia. Antigens coded by the MAGE gene family could be important molecules for understanding specific immunity against lymphocytic leukemia.

Acute Disease↗
PubMed1995

[Digital analysis of pulmonary nodules--potential usefulness of computer-aided diagnosis for differentiation of benign from malignant nodules].

Digital analysis of 80 plain chest radiographs was done to differentiate benign from malignant pulmonary nodules. Each of 80 radiographs had a solitary pulmonary nodule, of which 40 were benign and the other 40 were malignant. Radiographic features of nodules were visually evaluated. Frequencies of the radiographic features described below were significantly different between benign and malignant nodules: irregular shape, vague density, well-defined contour, spicular formation, and vascular convergene. To digitally evaluate the density characteristics, two kinds of concentric circular windows were used, to allow analysis of intra-nodular, marginal and surrounding regions of the nodules. Seventeen digital parameters were obtained by computerized analysis with the windows. There were significant differences in six digital parameters; three of density gradient (one of intra-nodular and two of marginal regions), one DCF-N (directional contrast filter for nodule) output of intra-nodular region, and two of density entropy values of intra-nodular and surrounding regions. Density gradient parameters of marginal regions are believed to represent the features of nodular shape and spicula formation. With these six parameters, 70% of benign nodules and 85% of malignant nodules were correctly discriminated. These results suggest that computer-aided diagnosis may be used to differentiate benign from malignant nodules.

Diagnosis, Computer-Assisted↗
PubMed1994

Rapid and sensitive diagnosis of cytomegalovirus and Pneumocystis carinii pneumonia in patients with haematological neoplasia by using capillary polymerase chain reaction.

We attempted the simultaneous detection of cytomegalovirus DNA (CMV-DNA) and Pneumocystis carinii (carinii-DNA) in sputum samples obtained from 20 patients with haematological neoplasm with pneumonia, using rapid cycle DNA amplification (capillary PCR). We used a thermal cycler for capillary PCR which featured recirculation of hot air for rapid temperature control of 10 microliters reaction samples in thin glass capillary tubes. We extracted DNA from patients' sputa using a simple method. A comparison of the results obtained using the phenol extraction-ethanol precipitation method and those obtained using our simple method was made, and demonstrated complete agreement between the two. For detection of CMV-DNA and P. carinii-DNA with capillary PCR it was not necessary to vary temperature setting based on the primers used. Therefore, capillary PCR was used for the simultaneous detection of CMV and P. carinii. After amplification, the total time required for which was 20 min, amplified products were electrophoresed on agarose gels and visualized with ethidium bromide. Product sensitivity was higher with capillary PCR than with conventional PCR. We conclude that capillary PCR amplification is a valuable tool for rapid and simple diagnosis of CMV and P. carinii pneumonias.

Adult↗
PubMed1994

[Treatment of cancer and counter-measures for MRSA infections].

Patients with malignancy, especially those with hematological malignancy, are well known to be very susceptible to infection in general, because of bone marrow suppression induced by anticancer chemotherapy in addition to the nature of the disease itself. Accordingly, the risk of MRSA infection is very high in these patients, and the infection is often fatal. In an attempt to establish effective measures to prevent MRSA infection, we investigated the nosocomial spread of strains of MRSA and studied the characteristics of patients from the clinical standpoint. We found that strict isolation of patients with MRSA infection is an urgent necessity to prevent the intrahospital spread of MRSA strains and that disinfection of the hands of medical staff and sterilization of the environment are extremely important. In addition, due care must be taken to select an adequate antimicrobial agent and to determine the optimal dose and period for treatment of the infection in patients with malignancy to avoid selecting MRSA strains or inducing resistance in mecA positive strains of S. aureus. For treatment of MRSA infections in patients with malignancy, a combination chemotherapy with vancomycin (VCM), or arbekacin (ABK) plus beta-lactam antibiotic is recommended, and granulocyte colony stimulating factor (G-CSF) is clinically useful when the granulocytopenia was induced by chemotherapy.

Adult↗
PubMed1993

Rapid diagnosis of cytomegalovirus and Pneumocystis carinii pneumonia by using the capillary polymerase chain reaction.

We attempted to detect cytomegalovirus DNA (CMV-DNA) and Pneumocystis carinii DNA (P. carinii-DNA) in sputum samples of 18 hematological neoplasm patients with pneumonia, using rapid cycle DNA amplification. A thermal cycler based on recirculating hot air was used for rapid temperature control of 10-microliters samples in this glass capillary tubes. After a total amplification time of 15 min, the amplified products were electrophoresed on agarose gels and visualized with ethidium bromide. In three cases, CMV-DNA was detected at about the time the pneumonia occurred. These patients were successfully treated with ganciclovir in the early stages of infection and CMV was not detected by the virus culture method. In four other cases, P. carinii-DNA was detected in their sputum samples but not detected by Grocott staining. These four cases of P. carinii were successfully treated with sulfamethoxazole-trimethoprim. For detection of CMV-DNA and P. carinii-DNA using the capillary polymerase chain reaction (PCR), a different temperature setting base on the primer difference was not necessary. Therefore, capillary PCR was performed at the same time for detection of CMV and P. carinii. We conclude that capillary PCR amplification is a valuable tool for rapid diagnosis and early treatment of pneumonia due to CMV and P. carinii.

Adult↗
PubMed1993

[In vitro and clinical studies of MRSA infections in compromised hosts].

From January to December 1991, 47 clinical cases in when methicillin-resistant Staphylococcus aureus (MRSA) strains were isolate were investigated at our internal medicine ward. The MRSA infection rate was 57.4% (27/47). The mortality due to MRSA bacteremia was 75.0% (9/12) and that due to MRSA pneumonia was 57.1% (4/7). We think that MRSA infections must be treated by multiple antibiotics. At out institution, most of the patients were given a combination therapy of imipenem + fosfomycin or imipenemt + mynocycline. Although in vitro the MICs of imipenem did not show excellent activity against MRSA strains, in vivo these combination therapy including imipenem showed excellent activity against MRSA infections. We think that this result was due to the additive effect of the two drug combination. We determined the MICs of single antibiotics against MRSA strains. Most of the MRSA strains were sensitive to minocycline and arbekacin. All MRSA strains were sensitive to vancomycin we think that vancomycin is a highly useful drug to combat MRSA infection.

Adult↗
PubMed1992

[Personal computer-based interpretation experiment system for digital chest images].

We have developed a system of nodule detection interpretation experiment on personal computers. This system is composed of three subsystems: practice, experiment and check modes. In the practice and experiment modes, chest radiographic images, each with or without a nodule, are shown in a random order on the monitor. The reader is then asked to point a location of nodule and to give a confidence rating. In the check mode, a subsystem shows locations of the real nodules and false positive foci on a figure of a chest radiograph. It also shows receiver operating characteristics of each reader. This system can precisely and easily perform an interpretation experiment. Then reader performance in detection of nodules can be accurately and promptly evaluated. This system, therefore, is very useful to perform a large-scale interpretation experiment in a constant reading condition.

Humans↗
PubMed1992

[Rapid diagnosis of cytomegalovirus pneumonia and Pneumocystis carinii pneumonia by using polymerase chain reaction DNA amplification].

We attempted to detect cytomegalovirus DNA (CMV-DNA) and Pneumocystis carinii DNA (carinii-DNA) in urine, blood and sputum samples of 16 leukemia patients with pneumonia, using the polymerase chain reaction (PCR). Synthetic oligonucleotide primer pair were used to amplify DNA from the major immediately genes of CMV and genes for the large subunit of mitochondrial ribosomal RNA of P. carinii. Amplified products were detected by gel electrophoresis. In two cases, CMV-DNA was detected at about the time the pneumonia occurred, and in one of the two cases, CMV-DNA was detected in the sputum sample. This patient was treated immediately with ganciclovir. After ganciclovir treatment, clinical and biochemical signs of CMV pneumonia disappeared. In three cases, carinii-DNA was detected in their sputum samples. In their blood and urine samples, carinii-DNA were not detected. This three cases were treated with sulfamethoxazole-trimethoprim and successfully treated episodes of P. carinii pneumonia. We conclude that PCR amplification may be a valuable tool for rapid diagnosing CMV pneumonia and P. carinii pneumonia.

Base Sequence↗
PubMed1992

Fecal and stomal bile acid composition after ileostomy or ileoanal anastomosis in patients with chronic ulcerative colitis and adenomatosis coli.

Fecal bile acids (FBA) were analyzed by gas-liquid chromatography in 29 patients [17 with ulcerative colitis (UC) and 12 with adenomatosis coli (AC)] and 5 healthy volunteers. Seven UC and 9 AC patients had undergone total colectomy and J-shaped ileal pouch-anal anastomosis (JAA). The mean daily FBA output was similar for JAA and terminal ileostomy patients (approximately 370 mg/day), and was about 1.5 times that of healthy Japanese volunteers (approximately 235 mg/day). The output of unconjugated bile acids, secondary bile acids, and 7-dehydroxylated bile acid was higher in JAA patients with UC than in terminal ileostomy patients, but there were no significant differences between the groups. The total fecal bacterial count in JAA patients was 10 times that in terminal ileostomy patients but was 1/10 of that in healthy volunteers. In patients with defunctioning high ileostomy, FBA output increased markedly (maximum, 3054 mg/day), and serum cholesterol levels were also significantly lower (P less than 0.05). These results suggest that after JAA the bile acid metabolism and fecal bacterial flora undergo more normalization than after terminal ileostomy.

Adenomatous Polyposis Coli↗
PubMed1991

Leukaemia of novel gastrointestinal T-lymphocyte population infected with HTLV-I.

In a 72-year-old man with watery diarrhoea and leukocytosis the proliferation of abnormal cells was studied in specimens obtained by endoscopic biopsy of the gastrointestinal tract. Flow cytometry of leukaemia cells revealed a monoclonal expansion of "double-negative" (CD4-, CD8-) cells bearing T-cell receptor (TCR) alpha beta products. Southern blotting confirmed monoclonal integration of HTLV-I. A novel T-cell subset of double-negative TCR alpha beta cells in the gastrointestinal tract in adult man may be a target for HTLV-I infection.

Aged↗