Biomedical subjects

Masato Minami

Publications and source records attributed to Masato Minami.

31 records · Page 2Linked to original sources

PubMed2004

Lymphangiogenesis in lymphangioleiomyomatosis: its implication in the progression of lymphangioleiomyomatosis.

Lymphangioleiomyomatosis (LAM) is characterized by the proliferation of abnormal smooth muscle cells (LAM cells) in the lungs, lymph nodes, and/or other organs. We examined lymphangiogenesis using immunohistochemistry for Flt-4 (VEGFR-3), a new specific marker for lymphatic endothelial cells, as well as the expression of vascular endothelial growth factor (VEGF)-C in LAM. Specimens were obtained from 6 autopsy cases, a single lung transplant case, and 8 surgical cases for analyses. We demonstrated that lymphatics were extremely abundant in both pulmonary and extrapulmonary LAM and that lymphatic endothelial cells not only proliferated encompassing LAM foci but also infiltrated the intra-LAM foci, and that in advanced LAM, lymphangiogenesis involved vascular walls and interstitium surrounding the area where LAM cells proliferate. In contrast, angiogenesis, confirmed with CD31 immunostaining, was observed less in the LAM foci. LAM cells demonstrated positive reactivity against anti-VEGF-C antibody at varying intensities. Significant correlation (P < 0.001) was noted between the degree of lymphangiogenesis in LAM or VEGF-C expression on LAM cells and lymphagioleiomyomatosis histologic score (LHS), which represents the histologic severity of pulmonary LAM and has been reported to have prognostic significance. Our study is likely to provide a novel point of view on the pathophysiologic significance of lymphangiogenesis in LAM.

Adult↗

PubMed2004

[A case of bronchostenosis in the allograft after lung transplantation in pulmonary lymphangioleiomyomatosis].

Pulmonary lymphangioleiomyomatosis (LAM) is a rare disease characterized by hamartomatous proliferation of abnormal smooth muscle cells in the lungs. Recently, severe LAM has been listed as an indicated disease for lung transplantation. A 34-yr-old woman with severe pulmonary cystic changes in a chest CT scan was diagnosed as having an isolated form of pulmonary LAM without genetic disorders. Despite intensive progesterone treatment, her pulmonary functions deteriorated rapidly. In January 2001, a left single-lung transplantation was performed from a cadaveric donor. The total operating time was 8 hours and 47 minutes. Total ischemic time was 5 hours and 59 minutes, which was within the permitted time limit. Except for right pneumothorax, the postoperative course was fairly good without any sign of rejection or infection in the allograft. For about two months after transplantation, bronchostenosis occurred in the left lower lobe bronchus, and necessitated a stent placement. During the following three months, stenosis of the bronchi in the anastomotic and peripheral sites occurred repeatedly, which also necessitated stent placement or balloon dilations on each occasion. Despite all the intensive treatment, the bronchostenosis of the peripheral sites still remains and improvement of her pulmonary functions has been poor. Moreover, a recent chest CT scan revealed a progression of the disease in the native lung. Consequently, we registered her as a candidate for transplantation of the right lung. Bronchostenosis should be kept in mind as a complication of lung transplantation.

Adult↗

PubMed2003

Primary germ cell tumors in the mediastinum: a 50-year experience at a single Japanese institution.

BACKGROUND: Primary germ cell tumors (GCT) of the mediastinum share similar clinical and biologic characteristics, which are different from their testicular counterpart. The purpose of the current study was to review the authors' institutional experience of mediastinal GCT, emphasizing the clinical spectrum, time trends of treatment, and recent advances in therapeutic modalities for malignant GCT. METHODS: Between 1951 and 2000, 129 patients (70 males and 59 females) underwent surgical treatment for GCT, which accounted for 16.0% of the mediastinal tumors during the same period. There were 95 patients with mature teratomas, 13 patients with seminomas, and 21 patients with nonseminomatous germ cell tumors (NSGCT) with median ages of 26.4 years, 27.6 years, and 28.5 years, respectively. RESULTS: Adult patients with mature teratomas were less symptomatic (33.3%) than pediatric patients (52.4%). All patients with mature teratoma were cured by resection alone. Eight of the 13 patients (61.5%) with seminoma were symptomatic and 10 of 13 patients (83.3%) survived after surgery and radiation with/without chemotherapy. Nineteen of 21 patients (90.5%) with NSGCT had dyspnea, chest pain, and superior vena cava syndrome. Before 1985, patients received radical resection and/or chemoradiotherapy. However, all patients died due to disease progression, with a median survival period of 7.6 months. After 1986, six of eight patients received cisplatin-based chemotherapy, including three who received additional high-dose chemotherapy with a supporting peripheral blood stem cell transplantation until tumor markers normalized. Five patients who underwent salvage resection are currently disease free with a median survival period of 58.3 months. CONCLUSIONS: The institutional experience indicates the benign nature of mediastinal mature teratomas and the excellent prognosis for patients with seminomas after resection. An improved survival advantage was ensured with cisplatin-based preoperative chemotherapy in patients with NSGCT.

Adolescent↗

PubMed2003

Clinical spectrum of primary mediastinal tumors: a comparison of adult and pediatric populations at a single Japanese institution.

BACKGROUND AND OBJECTIVES: The purpose of this study was to review our Japanese institutional experience of mediastinal tumors and to compare differences in the clinical spectrum between adults and children. METHODS: We retrospectively reviewed the records of 806 patients (676 adults and 130 children) between 1951 and 2000 at our institution. RESULTS: There were 244 thymomas (36%), 106 germ cell tumors (16%), 95 congenital cysts (14%), 82 lymphomas (12%), 76 neurogenic tumors (11%), and 24 thyroid tumors (4%) in adult patients. There were 60 neurogenic tumors (46%), 24 germ cell tumor (19%), 17 lymphoma (13%), 10 congenital cysts (8%), and 5 thymomas (4%) in the pediatric patients. There was a significant higher incidence of neurogenic tumors and a lower incidence of thymomas and thyroid tumors in children than adults. The most common location was the anterior compartment (68%) in adults and the posterior compartment in children (52%). The prevalence of malignancy in pediatric patients was lower than adults (37% vs. 47%; P < 0.05). Symptoms due to compression or direct invasion into adjacent structures may have caused the higher incidence of dyspnea or respiratory distress in the pediatric group compared to the adults (15.4% vs. 4.0%; P < 0.001). There were fewer incidences of facial edema in children compared to adults (2.6% vs. 10.7%; P < 0.02). Emergent operations were required more often in the pediatric group than the adult group. CONCLUSIONS: We demonstrated definite differences in histologic distribution, location, and symptomatology in mediastinal tumors between adult and pediatric populations, which should be considered in the evaluation and planning of a therapeutic modality for mediastinal tumors.

Adolescent↗

PubMed2003

Thoracoscopic thymectomy using anterior chest wall lifting method.

We performed a thoracoscopic resection of thymus and thymoma using a novel method whereby the chest wall was lifted by costal hooks placed on the bilateral third ribs. Since the thymus and fat tissue were also elevated, the mediastinal dissection was started at the underlying vessels and pericardium. This technique conforms to the purpose of endoscopic surgery, as it maximizes the operative field and minimizes chest wall trauma. We have applied this approach to benign mediastinal tumor and stage I thymoma with satisfactory results.

Humans↗

PubMed2003

Enhanced intestinal inflammation induced by dextran sulfate sodium in tumor necrosis factor-alpha deficient mice.

BACKGROUND AND AIMS: Tumor necrosis factor-alpha (TNF-alpha) is a potent pro-inflammatory cytokine thought to be involved in the pathogenesis of inflammatory bowel disease. To further define the role of TNF-alpha in intestinal inflammation, we studied the effects of dextran sulfate sodium (DSS) administration in mice with targeted deletions of TNF-alpha gene. METHODS: Acute colitis was induced in female TNF-alpha-/- and TNF-alpha+/+ mice by administering 4.5% DSS orally in drinking water for seven days. The colonic mucosal injury and inflammation was evaluated based on body weight changes, total colon length, luminal hemoglobin, and histological findings. Colonic mRNA expression for inducible nitric oxide synthase (iNOS), TNF-alpha, interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) were measured by reverse transcription polymerase chain reaction (RT-PCR), and nuclear factor kappaB (NF-kappaB) activation was evaluated by electrophoretic mobility shift assay. RESULTS: In each assessment, colonic injury was significantly aggravated in DSS-treated TNF-alpha-/- mice compared with DSS-treated TNF-alpha+/+ mice. The survival rate of TNF-alpha-/- mice on day seven was 40%; in contrast, all TNF-alpha+/+ mice were alive. Histological study also showed an enhanced infiltration of inflammatory cells, especially neutrophils, and mucosal cell disruption in DSS-treated TNF-alpha-/- mice compared with DSS-treated TNF-alpha+/+ mice. On day seven, mRNA levels of IFN-gamma and IL-4 in the colons of TNF-alpha-/- mice were faint or not detected; in contrast, those of TNF-alpha+/+ mice were detected. Although the expression of iNOS mRNA and luminal nitrite levels were similarly increased in both mice on day seven, this induction was delayed in TNF-alpha-/- mice during the early phase. The degree of NF-kappaB binding activity seemed to be similar between the two types of mice on day seven. CONCLUSION: DSS-induced inflammation is significantly enhanced in TNF-alpha-/- mice compared to TNF-alpha+/+ mice. These data suggest that persistent and marked blockage of TNF-alpha bioactivity may provide a detrimental effect on acute intestinal inflammation.

Acute Disease↗

PubMed2003

The inhibitory effect of essential oils on herpes simplex virus type-1 replication in vitro.

The antiviral effect of 12 essential oils on herpes simplex virus type-1 (HSV-1) replication was examined in vitro. The replication ability of HSV-1 was suppressed by incubation of HSV-1 with 1% essential oils at 4 C for 24 hr. Especially, lemongrass completely inhibited the viral replication even at a concentration of 0.1%, and its antiviral activity was dependent on the concentrations of the essential oil. When Vero cells were treated with the essential oil before or after viral adsorption, no antiviral activity was found, which suggests that the antiviral activity of essential oils including lemongrass may be due to the direct interaction with virions.

Antiviral Agents↗

PubMed2003

Clinical spectrum of mediastinal cysts.

OBJECTIVES: Congenital cysts of the mediastinum are an uncommon but important diagnostic group, representing 12 to 30% of all mediastinal masses. The purpose of this study was to review our institutional experience with congenital cysts of the mediastinum, emphasizing the clinical spectrum of the disease. DESIGN: Retrospective study. OBJECTIVES: University hospital unit of general thoracic surgery. METHODS: We retrospectively reviewed the records of 105 patients with cysts of the mediastinum (50 male and 55 female patients) who comprised 13.0% of mediastinal masses over the past 50 years. RESULTS: There were 10 pediatric patients (< 15 years old) and 95 adult patients. The prevalence of cysts in the adult populations was higher than that in children (14.1% vs 7.7%, p < 0.05). There were 47 bronchogenic cysts, 30 thymic cysts, 12 pericardial cysts, 7 pleural cysts, 4 esophageal duplications, 2 meningoceles, 1 thoracic duct cyst, and 2 others. MRI has become a useful tool for providing supplemental data in combination with CT. Overall, 38 patients (36.2%) with mediastinal cysts were symptomatic, including 39.2% with bronchogenic/esophageal cysts, 40% with thymic cysts, and 15.8% with pericardial/pleural cysts. One hundred patients had complete resection of their masses, 3 patients with pericardial diverticulum received a thoracoscopic fenestration without mortality, and 2 patients refused surgery. CONCLUSION: Early recognition of these relatively rare lesions would lead to immediate and appropriate surgical intervention. Early surgical intervention is also important because definitive histologic diagnosis can only be established by means of surgical extirpation.

Adult↗

PubMed2002

Bilateral cervicomediastinal neurofibroma originating from the vagal nerve in a patient with von Recklinghausen's disease: report of a case.

A 19-year-old woman with von Recklinghausen's disease was admitted with symptoms of hoarseness. A computed tomography scan showed a bilateral cervicomediastinal tumor. An extirpation of the left cervicomediastinal tumor was performed for the purpose of diagnosis and treatment. On thoracotomy, the tumor, which measured 9 x 8 x 4 cm in size, arose from the intrathoracic vagal nerve and the left tumor was resected with a segment of the vagal nerve and recurrent nerve. The pathological diagnosis of the tumor was a neurofibroma. The tumor on the right side was left untreated due to concerns about possibly causing palsy of the bilateral recurrent nerve and also because of the asymptomatic state of the right tumor. Mediastinal neurofibroma in a patient with von Recklinghausen's disease often arises from the intrathoracic vagal nerve. To our knowledge, this is the first report of bilateral cervicomediastinal neurofibroma originating from the vagal nerves.

Adult↗

PubMed2002

Role of IFN-gamma and tumor necrosis factor-alpha in herpes simplex virus type 1 infection.

One of the characteristics of herpes simplex virus type 1 (HSV-1) is that recurrent diseases often develop from latent infection established after acute infection. Cytokines have been proposed to play an important role in each stage of HSV-1 infection, but the exact role of cytokines remains unclear. In the present study, we investigated the role of interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) in acute infection and reactivation using IFN-gamma gene knockout (IFN-gamma(-/-)) mice and TNF-alpha gene knockout (TNF-alpha(-/-)) mice. We first examined the survival rate after corneal infection with HSV-1. The survival rates of wild-type C57BL/6 (B6) mice, IFN-gamma(-/-) mice, and TNF-alpha(-/-) mice were 97% (73 of 75), 57% (24 of 42), and 83% (60 of 72), respectively. These results suggest that TNF-alpha and IFN-gamma play a protective role in acute infection with HSV-1. We also examined the rate of reactivation induced by ultraviolet (UV) light in latently infected mice over 60 days postinoculation. The reactivation was confirmed by detecting viral DNA extracted from eyeballs by the polymerase chain reaction (PCR) method at day 2 after the UV light stimulation. The rates of reactivation in IFN-gamma(-/-) mice and TNF-alpha(-/-) mice were significantly higher than that in B6 mice; 16% (4 of 25) showed reactivation in B6 mice, 47% (9 of 19) in IFN-gamma(-/-) mice, and 48% (10 of 21) in TNF-alpha(-/-) mice. These results suggest that IFN-gamma and TNF-alpha play an important role in acute infection and reactivation from latency.

Acute Disease↗

PubMed2002

Antibacterial effect of Kampo herbal formulation Hochu-ekki-to (Bu-Zhong-Yi-Qi-Tang) on Helicobacter pylori infection in mice.

Because Helicobacter pylori (H. pylori) infection is a major cause of gastroduodenal diseases in humans, the eradication of H. pylori using antibiotics is very effective for the treatment of gastroduodenal diseases. However, it has recently been reported that resistance to these antibiotics is developing. In the present study, the antibacterial effect of a Kampo (traditional Japanese medicine) herbal formulation, Hochu-ekki-to (RET; Formula repletionis animalis et supletionis medii), against H. pylori was examined in vitro and in vivo. HET inhibited the growth of antibiotic-resistant strains of H. pylori as well as antibiotic-sensitive strains at a dose of 2.5 mg/ml in vitro. When 1,000 mg/kg of HET was administered orally to C57BL/6 mice for 7 days before or after inoculation with H. pylori, H. pylori in the stomach was significantly reduced in the HET-pre-treatment group compared with the control group. Furthermore, HET in combination with antibiotics completely eradicated the bacteria in mice. The expression of interferon (IFN)-gamma was induced in the gastric mucosa of the mice pre-treated with HET. There were no significant differences between the colonization of H. pylori in the control and HET treatment groups in IFN-gamma gene-deficient mice. These results suggest that the antibacterial effect of HET may be partly due to IFN-gamma induction, and that HET may be clinically useful for treatment of H. pylori infection.

Administration, Oral↗

PubMed2002

[Postoperative management in single-lung transplantation for lymphangioleiomyomatosis].

A 35-yr-old woman presented with dyspnea has been diagnosed as having lymphangioleiomyomatosis (LAM). Despite treatment with estrogen, her pulmonary function deteriorated progressively. In January 2001, a left single-lung transplantation was performed on her from a cadaveric donor. On admission to the ICU after the transplantation, arterial blood gas analysis showed a severe respiratory acidosis. A double-lumen endotracheal tube (ETT) was replaced by a single-lumen ETT for a better suctioning of secretion. Gas exchange improved after the replacement of ETT and suctioning of secretion by bronchoscopy. Five hours after the admission to the ICU, the breath sound decreased over the right thorax. The chest X-ray showed right pneumothorax, and a chest tube was inserted. The patient was weaned from mechanical ventilation gradually and extubated on the 6th ICU day. The patient was discharged from ICU to the general ward on the 9th ICU day without pneumonia and other complications. The development of pneumothorax in the recipient lung should be kept in mind during the perioperative period of lung transplantation for LAM.

Adult↗

PubMed2002

[NSIP group III treated with the first cadaveric single lung transplantation in Japan].

A 43-year-old woman developed dyspnea on effort in January 1996. She was treated with various antibiotics but developed dyspnea and pretibial edema. She was referred to our hospital and admitted on February 20, 1996. On the basis of the clinical course and radiological findings, she was diagnosed as having idiopathic pulmonary fibrosis with right-side heart failure. After high-dose steroid therapy (methylprednisolone, 1,000 mg/day for 3 days) and the administration of a diuretic, oral prednisolone therapy was initiated. Her condition gradually recovered. To obtain a definite diagnosis, an open lung biopsy was recommended but the patient refused the procedure. She was discharged from the hospital and placed on home oxygen therapy. After her informed consent was obtained, she became a candidate recipient for the nationwide Central Lung Transplant Evaluation Committee on August 7, 1998. Her name was then listed in the Japan Organ Transplant Network. The patient was admitted to our hospital in October 1998 because of respiratory failure. She underwent left lung transplantation at Osaka University Hospital on March 29, 2000. After the lung transplantation, she was discharged and is presently doing well without the need for supplementary oxygen. A differential diagnosis of the removed lung as nonspecific interstitial pneumonia (NSIP) group III or UIP was required. We finally diagnosed NSIP group III because of the temporal uniformity and diffuse distribution of the fibrosis. In this report, we also describe the background of the clinical diagnosis, the indications for lung transplantation and the clinical course before and after transplantation.

Adult↗