Biomedical subjects

Hajime Saito

Publications and source records attributed to Hajime Saito.

At least 19 recordsLinked to original sources

PubMed2006

Tumor-derived TGFbeta-1 induces dendritic cell apoptosis in the sentinel lymph node.

Lymphatic flux from a primary tumor initially flows into a tumor-draining lymph node (LN), the so-called sentinel LN (SLN). Carried by the lymph fluid are a variety of mediators produced by the tumor that can influence immune responses within the SLN, making it a good model with which to investigate tumor-related immunology. For instance, dendritic cell (DC) numbers are reduced in SLNs from melanoma and breast cancer patients. In the present study, we investigated the mechanism by which DC numbers were reduced within SLNs from patients with non-small cell lung cancer. We found that the incidence of apoptosis among DCs was higher in SLNs than in non-SLNs, as were levels of TGFbeta-1. In contrast, levels of TGFbeta-1 mRNA did not differ between SLNs and non-SLNs, but were 30 times higher in tumors than in either LN type. In vitro, incubation for 2 days with TGFbeta-1 induced apoptosis among both cultured DCs and DCs acutely isolated from normal thoracic LNs, effects that were blocked by the TGFbeta-1 inhibitor DAN/Fc chimera. Taken together, these results suggest that tumor-derived TGFbeta-1 induces immunosuppression within SLNs before the movement of tumor cells into the SLNs, thereby facilitating metastasis within those nodes.

Apoptosis↗

PubMed2006

Giant cell tumor of the sternum.

A primary giant cell tumor (GCT) originating from the sternum is extremely rare. We report a case of a GCT originating from the sternum in a 45-year-old man who was referred to us for a mass in the anterior chest wall that had been growing slowly. Computed tomography revealed a soft tissue mass involving a large osteolytic and destructive lesion of the sternum body. Subtotal sternectomy and reconstruction with methylmethacrylate were performed. The tumor was 8.5 x 4.5 x 2.5cm, and the histopathological examination confirmed GCT. Radical wide resection of primary sternum tumors and reconstruction with an appropriately rigid prosthetic material are necessary to minimize local recurrence.

Bone Neoplasms↗

PubMed2006

Intraoperative sentinel lymph node mapping using a new sterilizable magnetometer in patients with nonsmall cell lung cancer.

PURPOSE: We recently developed a novel method for sentinel lymph node mapping using magnetic force. However, problems with the sterility and sensitivity of the magnetometer made intraoperative sentinel lymph node mapping impossible. The purpose of this study was to test the utility of a new, more sensitive, sterilizable magnetometer developed in our institute for in vivo sentinel lymph node mapping in patients with nonsmall cell lung cancer. DESCRIPTION: Ferumoxides (magnetite) served as the tracer. Twenty patients with nonsmall cell lung cancer participated in the study. Each received 5 mL of ferumoxides, which were injected around their tumor. Magnetic force was then measured intraoperatively using the new sterilizable magnetometer. EVALUATION: The in vivo sentinel lymph node detection rate was 80.0% (16 of 20). The accuracy, sensitivity, and false-negative rates were 100% (16 of 16), 100% (4 of 4) and 0% (0 of 12), respectively. Our preliminary study indicates that our new magnetometer enables in vivo sentinel lymph node mapping in patients with nonsmall cell lung cancer. CONCLUSIONS: This device safely and accurately detected sentinel lymph nodes in nonsmall cell lung cancer patients.

Aged↗

PubMed2006

Comparative study of two typing methods, hsp65 PRA and ITS sequencing, revealed a possible evolutionary link between Mycobacterium kansasii type I and II isolates.

One hundred and ninety-eight clinical isolates of Mycobacterium kansasii collected between 2003 and 2004 in Japan were genotyped by PCR and restriction enzyme analysis (PRA) and 16S-23S internal transcribed spacer (ITS) sequencing. The results demonstrated that clinical isolates of M. kansasii in Japan are almost exclusively of the type I PRA genotype, as is the case in other countries. Although the results of subtyping using the 16S-23S ITS sequence were generally consistent with subtyping using hsp65 PRA, four strains showed a discrepancy between the two methods. Sequence analysis of the hsp65, gyrB and 16S rRNA genes and the ITS sequence of the four strains suggests that they branched from type II and could be considered an ancestral strain of the type I strain. The newly recognized strains were designated as intermediate type I.

Bacterial Proteins↗

PubMed2006

Nerve damage in Mycobacterium ulcerans-infected mice: probable cause of painlessness in buruli ulcer.

Buruli ulcer is an emerging chronic painless skin disease found in the tropics and caused by Mycobacterium ulcerans; however, it remains unknown why the large and deep ulcers associated with this disease remain painless. To answer this question, we examined the pathology of BALB/c mice inoculated in the footpads with M. ulcerans African strain 97-107. On days 54 to 70 after inoculation, extensive dermal ulcers, subcutaneous edema, and numerous acid-fast bacilli were noted at the inoculate region. Nerve invasion occurred in the perineurium and extended to the endoneurium, and some nerve bundles were swollen and massively invaded by acid-fast bacilli. However, Schwann cell invasion, a characteristic of leprosy, was not observed. Vacuolar degeneration of myelin-forming Schwann cells was noted in some nerves which may be induced by mycolactone, a toxic lipid produced by M. ulcerans. Polymerase chain reaction analysis of microdissected nerve tissue sections showed positive amplification of M. ulcerans-specific genomic sequences but not of Mycobacterium leprae-specific sequences. Behavioral tests showed decrease of pain until edematous stage, but markedly ulcerated animals showed ordinary response against stimulation. Our study suggests that the painlessness of the disease may be partly due to intraneural invasion of bacilli. Further studies of nerve invasion in clinical samples are urgently needed.

Animals↗

PubMed2005

Effect of antithrombin III on neutrophil deformability.

As the spherical diameter of pulmonary capillaries is smaller than that of neutrophils, increased neutrophil stiffness or conversely, decreased neutrophil deformability is a key step in the initial sequestration of neutrophils within the lungs during inflammatory processes. Antithrombin III (AT) is known to exert a therapeutic effect against disseminated intravascular coagulation, and accumulating evidence suggests that AT also has anti-inflammatory properties. The mechanisms of its anti-inflammatory effects remain unclear, but in a rat endotoxin model, AT apparently inhibited neutrophil sequestration in the lung. In the present in vitro study, therefore, we examined the effect of AT on the deformability of human neutrophils and correlated those findings with their F-actin content. Isolated human neutrophils were stimulated with formyl-Met-Leu-Phe (1 muM, 2 min) in the presence or absence of the alpha, beta, or low heparin-affinity isoforms of AT (1 IU/ml, 20 min), and deformability was evaluated using a filter assay system. Neutrophils were also stained with fluorescein isothiocyanate-phalloidin and subjected to a fluorescein-activated cell sorter scan to assess F-actin content. The results showed that pretreatment with any of the three AT isoforms similarly inhibited the decreased neutrophil deformability and increased F-actin content of stimulated cells. Notably, heparinase had no effect on deformability or F-actin content in the presence or absence of AT, which was somewhat unexpected, as heparin sulfate proteoglycans likely function as AT receptors. These findings suggested that AT inhibits the increase in neutrophil stiffness seen during inflammatory processes by inhibiting actin polymerization via a heparin-independent pathway.

Actins↗

PubMed2005

Increased expression of myosin light chain kinase mRNA is related to metastasis in non-small cell lung cancer.

BACKGROUND: The invasiveness of tumor cells depends in large part on their motility, which in turn depends on cytoskeletal function. A major cytoskeletal component involved in cell motility is myosin II, the classical form of myosin first identified in muscle but also expressed in nonmuscle cells. Myosin II is activated by myosin light chain kinase (MLCK), which phosphorylates it on its regulatory light chain. In this context, the contribution made by MLCK to tumor cell motility and invasiveness has been investigated extensively in vitro, but clinical evidence of such a contribution has been lacking. In the present study, therefore, we examined the role of MLCK in the metastasis of non-small cell lung cancer (NSCLC) in a clinical setting. METHODS: We measured MLCK mRNA expression in tumor samples from 39 NSCLC patients using real-time semiquantitative reverse transcription polymerase chain reaction carried out in a LightCycler. We then correlated MLCK mRNA expression with known clinicopathological factors. RESULTS: We found that levels of MLCK mRNA expression were higher in patients who showed disease recurrence and distant metastasis than in those who did not. Moreover, the 3-year disease-free survival rate among patients showing lower levels of MLCK mRNA expression [log10(MLCK/GAPDH) <1.4] was significantly greater than among those showing higher MLCK mRNA expression [log10(MLCK/GAPDH) > or =1.4] (87.5 vs. 50.0%; log-rank test, p = 0.021). CONCLUSION: These findings are the first clinical evidence that expression of MLCK is correlated with disease recurrence and distant metastasis in NSCLC.

Adult↗

PubMed2005

Dictyostelium discoideum requires an Alix/AIP1 homolog, DdAlix, for morphogenesis in alkaline environments.

Alix and its homologs are involved in various phenomena such as endosomal protein-sorting and adaptation to stress conditions. In this study, we found that development of Dictyostelium discoideum Alix (DdAlix) deletion mutant (alx-) cells was impaired in alkaline pH environments. The fruiting body formation efficiency of alx- cells at pH 9.0 was significantly lower than that of wild-type cells (6.8+/-4.2% vs 93+/-6.3%). The alkaline-sensitive phenotype of alx- cells was rescued by addition of salt. The phenotype was rescued by exogenous expression of human Alix as well as DdAlix but not by that of either Saccharomyces cerevisiae Alix homolog Rim20 or Bro1. DdAlix may be, structurally and functionally, more related to human Alix than to yeast Rim20 and Bro1.

Alkalies↗

PubMed2005

Intraoperative detection of lymph node micrometastasis with flow cytometry in non-small cell lung cancer.

OBJECTIVE: We sought to determine whether cytokeratin-positive cells can be detected as markers of lymph node metastasis by using flow cytometry within a time frame suitable for intraoperative decision making in non-small cell lung cancer. METHODS: Five lymph nodes from each of 20 patients with non-small cell lung cancer were randomly selected for study. Each node was divided longitudinally into 3 pieces: one piece for flow cytometry, one for immunohistochemical staining, and the last for conventional hematoxylin and eosin staining. In both flow cytometry and immunohistochemistry, cytokeratin-positive cells were detected with the fluorescein isothiocyanate-conjugated anti-cytokeratin antibody AE1/AE3. RESULTS: Cytokeratin-positive nodes were detected by means of flow cytometry within 40 minutes. Eight (8%) of the 100 lymph nodes from 4 (20%) of the 20 patients were deemed positive for metastasis on the basis of conventional histologic examination. By contrast, 33 (33%) lymph nodes from 13 (65%) patients were deemed positive on the basis of immunohistochemical cytokeratin staining, and 38 (38%) lymph nodes from 14 (70%) patients were deemed positive on the basis of flow cytometric cytokeratin-positive cell detection. All nodes deemed positive for metastasis on the basis of conventional and immunohistochemical methods were also positive on flow cytometry. CONCLUSIONS: Flow cytometry enables rapid intraoperative diagnosis of nodal metastasis in patients with non-small cell lung cancer. Flow cytometric detection of cytokeratin-positive cells within lymph nodes correlates with their immunohistochemical detection, and its level of sensitivity is greater than that of conventional histologic staining and about equal to that of immunohistochemical staining.

Biomarkers, Tumor↗

PubMed2004

Expression of tissue factor mRNA and invasion of blood vessels by tumor cells in non-small cell lung cancer.

PURPOSE: Tissue factor (TF), an initiator of the extrinsic coagulation cascade, is also expressed in a wide range of cancer cells and plays an important role in cancer progression and metastasis, as well as in processes independent of the blood coagulation pathway. For example, by acting as an adhesion molecule enabling tissue invasion, TF may play a key role in the metastatic process and angiogenesis in non-small cell lung cancer (NSCLC). METHODS: To further investigate the role of TF on tumor cell invasion in NSCLC, we measured the TF mRNA expression in the tumors of 42 NSCLC patients using real-time quantitative reverse transcription - polymerase chain reaction carried out in a LightCycler. We then compared the TF mRNA expression with histological evidence of invasion of blood and lymphatic vessels by tumor cells. RESULTS: Although there was no significant relationship between the TF mRNA expression and the invasion of lymphatic vessels, the TF mRNA expression was significantly higher in tumors that invaded blood vessels (Log(10) TF mRNA/GAPDH mRNA = 2.16 +/- 0.18) than in those that did not (1.59 +/- 0.16; P = 0.03). CONCLUSION: These results suggest that TF plays a major role in blood vessel invasion by tumor cells in NSCLC.

Adult↗

PubMed2004

Mediastinal neurofibroma originating from the left intrathoracic phrenic nerve: report of a case.

We report a case of mediastinal neurofibroma originating from the left phrenic nerve in a 42-year-old woman who was referred to us after a routine chest X-ray showed a smooth, round abnormal shadow in the left middle lung field adjacent to the heart. We resected a 25 x 20 x 20-mm tumor by video-assisted thoracic surgery. Histopathological examination confirmed that the lesion was a mediastinal neurofibroma originating from the left phrenic nerve without von Recklinghausen's disease. Neurogenic mediastinal tumors originating from the phrenic nerve are very rare, and to the best of our knowledge, no other case of a mediastinal neurofibroma originating from the phrenic nerve in a patient without von Recklinghausen's disease has ever been reported.

Adult↗

PubMed2004

A common clonal origin of nodal marginal zone B-cell lymphoma and plasma cell myeloma demonstrating different immunophenotypes: a case report of composite lymphoma.

We demonstrated an 83-year-old male case of composite lymphoma. Before 18 years, he was diagnosed with nodal marginal zone B-cell lymphoma in the cervical lymph node. Peripheral blood showed anemia and IgA (kappa)-type monoclonal gammopathy (IgA; 3,625 mg/dL). Bone marrow aspiration biopsy exhibited plasma cell myeloma, in which atypical plasma cells were positive for cytoplasmic IgA (kappa) and atypical lymphoid cells intermingled were positive for CD20. In contrast, cervical lymph node biopsy revealed nodal marginal zone B-cell lymphoma, in which lymphoma cells were positive for cytoplasmic IgG (lambda). Southern blotting analysis of the IgH gene showed same clonal rearrangement band in both lymph node and bone marrow samples and additional band in the bone marrow. Sequence analyses of the IgH gene showed an identical sequence of CDR3 in both samples. Thus, we demonstrated a common clonal origin of composite lymphoma comprising nodal marginal zone B-cell lymphoma and plasma cell myeloma. Nodal marginal zone B-cell lymphoma recurred in cervical lymph node and involved into the bone marrow, differentiating into plasma cell myeloma in which Ig isotype switched and monoclonal gammopathy developed. Sequence analysis of the IgH gene was a powerful tool for determination of clonal origin.

Aged↗

PubMed2004

Antithrombin III diminishes production of oxygen radical in endotoxin-infused rat lung.

The interaction of antithrombin III (AT) with cell surface glycosaminoglycans is known to have an inhibitory effect on inflammatory processes. We evaluated the effect of AT on endotoxin-induced production of oxygen radical in the pulmonary circulation using a fluorescent imaging technique. Also measured was the myeloperoxidase content of the lung, which served as an index of neutrophil accumulation, and neutrophil F-actin levels. Four groups of rats were infused for 2 h with endotoxin at 4.5 mg/kg/h (Et group), physiological saline (CT group), 100 U/kg of AT + endotoxin (AT group), or 100 U/kg of low-heparin-affinity latent-AT + endotoxin (L-AT group), respectively. Production of oxygen radical, neutrophil accumulation, and neutrophil F-actin levels were all significantly higher in the ET and L-AT groups than in the CT or AT group. Moreover; the levels of myeloperoxidase within the lung were well correlated with levels of oxygen radical production, which was consistent with the electron microscopic finding that cerium was deposited almost exclusively around neutrophils. Thus, it appears that AT most likely reduces F-actin formation in neutrophil by binding to glycosaminoglycans (e.g., syndecan-4) on the neutrophil, thereby reducing neutrophil accumulation in the lung, which would in turn inhibit oxygen radical production in the lung.

Actins↗

PubMed2004

[Bacteriological features of Mycobacterium haemophilum isolated from skin lesions in an immunodeficient patient].

A 53-year-old, male patient presented with pain in the middle area of the back of his left foot. The painful area was associated with a reddish dome-shaped swelling of 24 by 18 mm which had ulcerated in the center part. Histopathologically, the cutaneous lesion consisted of an ulcer surrounded by abscess and granuloma and numerous acid-fast organisms were observed. Subsequently, the area just below the left inguinal area developed redness and swelling approaching the size of a quail egg. The patient responded favorably with rifampicin, levofloxacin, and minocycline therapy. The patient was immunodeficient, but negative for HIV-1 and HIV-2 antibodies and the etiology of his immunodeficient state is unclear. Skin tissues or pus were cultured at 37 degrees C on 2% Ogawa and BBL MGIT. Acid-fast organisms were recovered on MGIT within 4 to 12 days, while 2% Ogawa medium failed to recover acid-fast bacteria. Using growth from the positive MGIT tube as inoculum, MycoBroth, 7H9 broth, 7H11.2% Ogawa supplemented with or without iron complexes, and blood agar were inoculated and cultured at 30 and 37 degrees C. Growth at 30 and 37 degrees C was seen with MycoBroth, 7H9, hemin (60 microM) or ferric ammonium citrate (15 mg/ml) supplemented 7H11 and blood agar as well as 7H11 supplemented with factor X. Growth at 30 degrees C only was observed for ferric ammonium citrate supplemented 7H9 and 2% Ogawa. Generally, growth at 30 degrees C was better than that at 37 degrees C in all media. No growth at either temperature was observed with hemin or factor X supplemented 2% Ogawa. With respect to the biochemical characterization, the isolate was negative for niacin, nitrate reduction, urease, arylsulfatase, Tween 80 hydrolysis, catalase, 68 degrees C catalase, acid phosphatase, and tellurite reduction, while strongly positive for neutral red test. Sequencing of the 16S rRNA gene showed the isolate to be consistent with Mycobacterium haemophilum. Based on the composite characterization, the isolate was identified as M. haemophilum. This is the second case report of M. haemophilum infection in Japan in the literature.

Culture Media↗

PubMed2004

[Trial of finger contamination reduction of the operator in nerve block treatment: comparison of over- and under-table systems].

Fluoroscopy-guided intervention of the lumbar spine, such as nerve block, plays an important role in the management of disc hernia patients. However, irradiation of operators' fingers remains a problem even with careful collimation and operation, especially when performed by non-radiologists. We compared the irradiation doses of under-table and over-table fluoroscopy systems, and we discuss the most advantageous method of reducing irradiation. The effectiveness and conditions of use of lead protection gloves were also evaluated. Skin dose was monitored using polymethyl methacrylate (PMMA) and an electronic dose meter. The skin doses of over- and under-table fluoroscopy were compared using C-arm fluoroscopy. Finger irradiation dose with 0.03 mmPb protection gloves was also measured. The under-table method reduced skin dose by 95% compared with the over-table method. Thicker PMMA resulted in a higher rate of irradiation reduction. Protection gloves reduced radiation dose by half, although this reduction was cancelled when automatic brightness control (ABC) was utilized. Under-tube fluoroscopy was superior to over-tube fluoroscopy in reducing irradiation to the fingers.

Fingers↗

PubMed2004

[Comparison of inhibitory effect of rifalazil and rifampicin against Mycobacterium ulcerans infection induced in mice].

PURPOSE: Buruli ulcer is a human skin disease caused by Mycobacterium ulcerans infection, which is characterized by massive skin ulceration and persistent necrotic change. In recent years Buruli ulcer has rapidly emerged as an increasingly important cause of human morbidity around the world. The disease is endemic at least 32 countries in Africa, Western Pacific, Asia and South America, and it is considered the third most common mycobacterial infection of humans after tuberculosis and leprosy. An effective chemotherapeutic regimen against Buruli ulcer disease has not been established to date. In this study, the inhibitory effect of rifalazil (RLZ) against M. ulcerans was assessed in experimentally infected mice and compared to that of rifampicin (RFP). MATERIALS AND METHODS: Five-week-old BALB/c female mice were challenged with 25 microliters (CFU = 4 x 10(4) of M. ulcerans cultured in Middlebrook 7H9 broth in bilateral hind footpads. Mice were administered per os with a suspension of RLZ or RFP at 2.5, 5, or 10 mg/kg once daily 5 times per week starting from one day up to 6 weeks after infection. During the treatment, mice were observed weekly for footpad skin lesions and examined for footpad swelling. In addition, CFU enumeration was done on both hind footpads and spleen at 2, 4, and 6 weeks after initiating treatment. RESULTS: In the infected control mice group, slightly erythematous lesions and moderate swelling of footpads were observed 4 weeks after the infection. Ulcerative lesion was observed 6 weeks after the infection. Mean log10 CFU/footpad (FP) was 5.22 on day 1 after the infection and increased to 5.56, 6.29, and 7.33 at 2, 4, and 6 weeks after treatment was initiated in the treated groups. On the other hand, no visible erythema, swelling or ulcerative lesion in footpads were observed in RLZ-administered groups. Furthermore, log10 CFU/FP decreased to 4.14 after only 2 weeks of initiating treatment in 2.5 mg/kg administered group, i.e. the lowest dose employed group. Log10 CFU/FP decreased to < 2.1 in 6 weeks in the 10 mg/kg administered group, which was close to the detection limit (< 1.7) of the CFU assay. By contrast, inhibitory effect on disease progression and reduction of CFU were observed only in the group of mice given 10 mg/kg among RFP-administered groups: the reduction of CFU was not observed in the early period but 6 weeks after initiating treatment. CONCLUSION: These results clearly demonstrate that the in vivo anti-M.ulcerans activity of RLZ is much higher than RFP. RLZ activity against M. ulcerans can be expected to control the disease progression in the clinical applications.

Animals↗

PubMed2003

A novel method for sentinel lymph node mapping using magnetite in patients with non-small cell lung cancer.

OBJECTIVE: The detection rate of sentinel lymph nodes in patients with non-small cell lung cancer using isosulfan blue dye is too low for clinical use. Although exposure to radioactivity is reportedly minimal, special procedures are nonetheless required when a radioactive isotope is used as a tracer. Therefore, to eliminate the need for a radioactive tracer and to obtain a better detection rate than is obtained with isosulfan blue dye, we have developed a novel method that employs magnetite as the tracer. The aim of the present study was to test the feasibility of this technique. METHODS: The tracer employed was ferumoxides, a colloidal superparamagnetic iron oxide of nonstoichiometric magnetite. Thirty-eight non-small cell lung cancer patients participated in the study; each received 5 mL of ferumoxides, injected around the tumor intraoperatively. Fifteen minutes after injection, lung resection and lymph node dissection were carried out. The magnetic force within the lymph nodes was measured using a highly sensitive handheld magnetometer ex vivo. All lymph nodes were also subjected to conventional histological analysis. RESULTS: The rate of detection of sentinel lymph nodes was 81.6% (31/38). The accuracy, sensitivity, and false-negative rates were 96.8% (30/31), 85.7% (6/7), and 14.3% (1/7), respectively. CONCLUSION: Intraoperative sentinel lymph node mapping using ferumoxides and a highly sensitive magnetometer is a safe, accurate, and sensitive way to detect sentinel lymph nodes in non-small cell lung cancer patients.

Adult↗

PubMed2002

Mechanical properties of rat bone marrow and circulating neutrophils and their responses to inflammatory mediators.

Neutrophils are continuously released from the bone marrow (BM), and this release is accelerated during inflammation. This study compared the mechanical properties of mature neutrophils within the BM and the circulating blood, as well as the role of microtubule rearrangement in the release of neutrophils from the BM in rats. Neutrophils isolated from the BM were stiffer than neutrophils in the circulating blood, using magnetic twisting cytometry. BM neutrophils also contained more F-actin within the submembrane region than circulating neutrophils when examined using confocal microscopy, suggesting that mature quiescent neutrophils within the BM are stiffer than circulating neutrophils because of increased formation of F-actin beneath the plasma membrane. Complement protein 5 fragments or formylmethionyl-leucylphenylalanine (fMLP) induced a stiffening response within 2 minutes that was greater in circulating than in BM neutrophils. This stiffening required F-actin formation within the submembrane region but not microtubule rearrangement in both circulating and BM neutrophils. fMLP-induced shape changes were more pronounced in circulating than in BM neutrophils, which showed fewer and smaller pseudopods and fewer membrane irregularities. In vivo, fMLP induced neutropenia, sequestration of neutrophils within the pulmonary capillaries, and release of neutrophils from the BM. Studies using colchicine demonstrated that rearrangement of microtubules was not required for any of these processes but was required for normal trafficking of neutrophils through the pulmonary capillaries.

Actins↗