Biomedical subjects

Y Nagata

Publications and source records attributed to Y Nagata.

At least 55 records · Page 3Linked to original sources

PubMed2001

Evaluation of glass microspheres for intra-arterial radiotherapy in animal kidneys.

PURPOSE: To evaluate the histologic distribution of nonradioactive microspheres when intra-arterially infused into normal kidneys, and to evaluate the histologic changes after the infusion. MATERIALS AND METHODS: The glass microspheres were SiO2 microspheres with a smooth spherical shape measuring 20-30 micrometers in diameter with a specific gravity of 2.2 g/cm3. After the microspheres were mixed with contrast medium, they were infused into the renal artery. Twelve rabbits were sacrificed at 1 day, 3 days, 1 week, and 8 weeks after the treatment, respectively. The specimen was fixed with 10% buffered formalin, specially embedded in methyl methacrylate (MMA) resin and was stained by hematoxylin-eosin. The distribution of the microspheres in the kidney was analyzed microscopically, and histologic changes were also evaluated. RESULTS: The microspheres were found in arterioles whose diameters were about 20-30 micrometers, within normal kidneys. All vessels containing microspheres were confined to arterioles or arteries. No migration of microspheres was detected in the normal lung or the contralateral kidney. Severe ischemic changes were observed in kidneys, developing within 8 weeks of the infusion. CONCLUSION: Glass microspheres seemed to be a useful embolic material for intra-arterial radiation therapy.

Animals↗

PubMed2001

Patent foramen ovale complicated by paradoxical embolism and brain infarct in a patient with advanced ovarian cancer.

BACKGROUND: Recent investigations of patients with cerebral and peripheral arterial emboli of unknown cause suggest that paradoxical embolism through a patent foramen ovale might be responsible for more arterial embolic events than previously realized. CASE: A 60-year-old woman with advanced ovarian cancer presented with sudden onset of expressive aphasia and right upper hemiplegia postoperatively. A patent foramen ovale diagnosed by echocardiography with contrast combined with the presence of thrombosis in her right femoral vein leads us to speculate that her stroke was secondary to a paradoxical embolism. CONCLUSION: Paradoxical embolism should be considered in the differential diagnosis of ovarian cancer patients with embolic stroke and it may be appropriate to include a cardiac echo as part of the diagnostic evaluation.

Brain Infarction↗

PubMed2001

Meningeal carcinomatosis in patients with breast cancer: report of 8 patients.

BACKGROUND: Meningeal carcinomatosis (MC) is an uncommon but aggressive complication of advanced breast cancer with a recently increasing incidence. Although the prognosis is extremely poor for MC patients, early diagnosis and appropriate treatment are important. SUBJECTS AND METHODS: We reviewed 8 cases of MC from breast cancer at Kyoto University Hospital from 1990 to 1999. The median age was 51.5 years. All patients had widespread systemic metastases when diagnosed with MC. clinical symptoms were categorized into 3 groups: cranial nerve symptoms, spinal nerve symptoms, and other symptoms. Imaging studies were positive for MC in only 4 patients. Initial CSF cytology studies were positive in 4 patients, and repeated CSF cytology yielded positive results in the remaining 4 patients. Thus the median interval between the onset of any clinical symptom of MC and the initiation of treatment was 22.5 days (range 7 to 120 days ). All patients received whole brain radiotherapy (WBRT). Four patients were given intrathecal chemotherapy and/or intrathecal immunotherapy in addition to WBRT. RESULTS: Improvement of cranial nerve symptoms, spinal nerve symptoms, and other symptoms were observed in 3/5, 1/3, and 5/7 patients, respectively. Patients with cranial nerve symptoms who started WBRT within 29 days of the onset of the symptoms showed at least partial recovery whereas patients who started WBRT later showed no recovery. The median survival was 123 days (53 to 310 days). MC was the direct cause of death in 1 of 8 patients. CONCLUSION: When MC is clinically suspected, neither a negative imaging study nor a single negative CSF cytology can rule out MC. Prompt initiation of WBRT with or without intrathecal chemotherapy may be important for recovery from cranial nerve symptoms.

Adult↗

PubMed2001

A case of allergic reaction to surgical metal clips inserted for postoperative boost irradiation in a patient undergoing breast-conserving therapy.

We report a case of a 28-year-old woman with right-sided breast cancer. The patient had been treated for atopic dermatitis since her infancy. She underwent breast-conserving surgery (BCS) in July 1998, and three titanium clips were placed at the margin of the excision cavity at the time of surgery. Two months after surgery, the patient exhibited a rapid exacerbation of atopic dermatitis. Various drugs were suspected to be the cause of the allergic reaction, but the results of a bi-digital O-ring test (BDORT) suggested an allergic reaction to titanium clips. In August 1999, the patient underwent a second operation to remove the titanium clips under local anesthesia. Allergy to surgical titanium clips is a rare complication, but in patients with a history of severe allergic diseases, a preoperative immunologic examination should be performed and the patient's history of metal allergy should be investigated.

Adult↗

PubMed2001

Impact of boost irradiation with surgically placed radiopaque clips on local control in breast-conserving therapy.

BACKGROUND: The purpose of this study was to determine whether boost irradiation relying on radiopaque clips placed surgically around the resected margin of breast cancer contributes to increasing the local control rate in patients with close or positive margins in breast-conserving therapy (BCT). METHODS: Among 837 patients with breast cancer who underwent BCT between November 1987 and December 1998, 181 patients with close or positive surgical margins received boost irradiation following conventional tangential whole breast irradiation. Since 1994, four radiopaque clips were surgically placed around the resected margin of the breast cancer in 155 patients treated with wide excision. The four clips were clearly and accurately identified with a CT-simulator (CT-S). The boost irradiation field was automatically determined with a safety margin of 3 cm according to one-to-one correspondence of radiopaque clips to pathologically close or positive surgical margins. In the remaining 26 patients treated before 1994, the boost irradiation field was determined according to the skin tattoo of the primary tumor. RESULTS: The median follow-up period of the 155 patients receiving the radiopaque clips was 42 months (range: 19 to 78), and that of the 26 patients without the clips was 87 months. Local recurrence was observed in two of the 155 patients who underwent boost irradiation using the radiopaque clips 39 and 54 months after the surgery, while 4 of the 26 patients developed local recurrence 14, 23, 51, and 76 months after BCT. In three of the four patients without the clips developing local recurrences, local recurrences were observed at the margin of the boost irradiation field. The 5-year local recurrence-free survival rate of patients who received boost irradiation with the radiopaque clips was 97%, and that of patients without the clips was 88%. The difference of local recurrence-free survival rates between the patients with and without the clips was significant (p<0.05). CONCLUSION: Surgically placed radiopaque clips appear to be useful for determining adequate boost field in the BCT using the CT-S and help increase the local control rate.

Adult↗

PubMed2001

Treatment for aortic graft infection.

Nine patients with an aortic graft infection presented after undergoing aortic grafting. Seven of 9 patients underwent an initial aortic reconstruction in our hospital. The incidence of aortic graft infection was 1.5% (7/456). There were 6 cases of paraprosthetic infection and 3 cases of aortointestinal fistulas. The treatments consisted of a complete graft excision and an axillofemoral bypass in 6 patients, a complete graft excision alone, a partial graft excision and a femorofemoral bypass, and the preservation of the graft with omental wrapping and irrigation in 1 each. Broad-spectrum antibiotics were intravenously administered to all patients and were then replaced by selective antibiotics for the responsible organisms. All surviving patients received antibiotics orally for 3-6 months. The early postoperative mortality rate was 11.1%. Aortoduodenal fistula occurred in 1 patient with graft excision alone. Graft thrombosis occurred in 2 patients with an axillofemoral bypass. No late graft infection or stump blowout occurred in any patient. We believe that a complete excision of the infected graft as well as the maintenance of distal tissue perfusion is necessary. However, based on the condition of the patient, the appearance of the operating field, and the difficulty of a repeat operation, we would like to stress the importance of selecting the best and safest treatment plan for each case.

Administration, Oral↗

PubMed2001

Body fat distribution and body composition during GnRH agonist therapy.

OBJECTIVE: To identify the effects of GnRH agonist therapy on body composition (lean and fat mass components) and body fat distribution. METHODS: Fifteen women with uterine leiomyomas were given a GnRH agonist (leuprorelin acetate, 3.75 mg) monthly for 4 months. Weight, height, and body mass index (BMI, weight/height) were recorded. Regional and total body composition, trunk-leg fat ratio, bone mineral density of the lumbar spine (L2-L4), and total body were assessed by whole-body scanning with dual-energy x-ray absorptiometry before and after treatment. Uterine volume was measured by transabdominal ultrasonography. RESULTS: The mean (+/- standard deviation [SD]) lean mass of total body, trunk, and leg decreased significantly (36.3 +/- 4.9 to 35.4 +/- 4.4 kg, P <.01; 18.8 +/- 2.8 to 18.1 +/- 2.8 kg, P <.05; and 11.4 +/- 1.8 to 11.1 +/- 1.6 kg, P <.05; respectively), whereas body fat mass, percentage of body fat, and trunk fat mass increased significantly (20.8 +/- 4.8 to 21.8 +/- 4.6 kg, P <.01; 34.9 +/- 5.9 to 36.5 +/- 5.2%, P <.01; and 8.6 +/- 3.0 to 9.3 +/- 3.0 kg, P <.01; respectively). Trunk-leg fat ratio increased significantly (1.03 +/- 0.32 to 1.12 +/- 0.33, P <.05). Weight, BMI, arm tissue composition (lean and fat mass components), and leg fat mass did not change during 4 months of GnRH agonist therapy. Bone mineral density and uterine volume decreased significantly. CONCLUSION: Hypogonadism by GnRH agonist therapy induces lean mass loss, increased adiposity overall, and upper body fat accumulation.

Absorptiometry, Photon↗

PubMed2001

Relationship of androgens to muscle size and bone mineral density in women with polycystic ovary syndrome.

OBJECTIVE: To investigate the relationship of androgens to regional muscle size and bone mineral density (BMD) in women with polycystic ovary syndrome (PCOS). METHODS: Seventy-one amenorrheic and right-side dominant women with PCOS (mean age +/- standard deviation 28.1 +/- 6.7 years) were enrolled. Baseline characteristics included age, height, weight, and body mass index (BMI). Regional BMD and lean mass were measured by whole-body scanning with dual-energy x-ray absorptiometry. Serum levels of testosterone, dehydroepiandrosterone sulfate (DHEAS), and androstenedione were measured by radioimmunoassay. Correlations between regional BMD and variables were investigated using a Pearson correlation test and multiple regression analysis. RESULTS: Serum testosterone levels correlated significantly with lean mass of the left arm, right arm, trunk, left leg, and right leg (r =.34, P <.05 to r =.50, P <.01). Regional lean mass correlated significantly with respective regional BMD (r =.30, P <.05 to r =.68, P <.001). These relationships remained significant after adjusting for age, height, and weight. Serum testosterone levels were not correlated with BMD of the bilateral arms and lumbar spine. Although serum testosterone levels correlated with leg BMD (r =.34, P <.05 to r =.45, P <.01), significance did not persist after adjusting for respective regional lean mass. CONCLUSION: Testosterone influences regional BMD through increasing regional muscle mass in women with polycystic ovary syndrome.

Adult↗

PubMed2001

Preparation of platinum nanoparticles by sonochemical reduction of the Pt(IV) ions: role of surfactants.

Sonochemical reduction processes of Pt(IV) ions in water have been investigated in the presence of various kinds of surfactants such as sodium dodecylsulfate (SDS) and sodium dodecylbenzenesulfonate (DBS) as anionic surfactants, and polyethylene glycol monostearate (PEG-MS) as non-ionic, dodecyltrimethylammonium chloride (DTAC) and bromide (DTAB) as cationic surfactants. An improved colorimetric determination reveals that Pt(IV) ion is reduced to zero valent metal in two steps: step (1)--Pt(IV) ion to Pt(II) ion, and step (2)--Pt(II) ion to Pt(0), and after the completion of step (1), step (2) sets in. It appears that rapid scrambling reactions among platinum ions and/or atoms, that is, Pt(I) + Pt(IV)-->Pt(II) + Pt(III), etc. take place. In the sonolysis of aqueous solutions of SDS, DBS or PEG-MS, two kinds of organic reducing radicals, R(ab) and R(py), are proposed to contribute to the reduction. Radical R(ab) is formed from the reaction of the surfactants with primary radicals such as hydroxyl radicals and hydrogen atoms originated from the sonolysis of water, and radical R(py) is formed from the direct thermal decomposition of surfactants in the interfacial region between the collapsing cavities and the bulk water. R(ab) is effective for both the reduction steps, whereas R(py) is involved only in the reduction step (1). This fact coincides with the previous reported sonochemical reduction of Pt(II) ions. Hydrogen atoms themselves scarcely participate in the reduction. The average diameter (1.0 nm) of platinum particles prepared from the system of PEG-MS is smaller than those from the aqueous solution of anionic surfactant SDS (3.0 nm) and DBS (3.0 nm).

Journal Article↗

PubMed2001

Mitochondrial DNA reveal that domestic goat (Capra hircus) are genetically affected by two subspecies of bezoar (Capra aegagurus).

This article describes the complete sequences of the mitochondrial DNA displacement loop (D-loop) region and cytochrome b gene from domestic goats in Laos (Laos native) and wild goat "markhor" (C. falconeri). The wild goat "bezoar" (Capra aegagrus) has been considered to be the strongest candidate for the ancestor of the domestic goats (C. hircus); however, there is not sufficient molecular data to verify the hypothesis at present. In phylogenetic analyses, two wild goats, the markhor and the ibex (C. ibex), appeared as an outgroup, while the bezoar was located in a cluster of domestic goats. Mitochondrial haplotypes of Laos natives revealed two distinct major clusters: one was the same as the bezoar, the second, unique to Laos natives. The topology and calibrated levels of sequence divergence suggests that these clusters might represent at least two different subspecies of ancestral bezoars.

Animals↗

PubMed2001

Bullous pemphigoid sera react specifically with various domains of BP230, most frequently with C-terminal domain, by immunoblot analyses using bacterial recombinant proteins covering the entire molecule.

By immunoblot analyses of normal human epidermal extracts, the 230 kDa bullous pemphigoid antigen (BP230) is recognized by most bullous pemphigoid sera. By polymerase chain reaction using keratinocyte cDNA library as a template, we successfully amplified 3 cDNAs of about 3 kb, which covered whole human BP230 molecule. By inserting the cDNAs into bacterial expression vector pGEX, we prepared 3 different recombinant glutathione-S-transferase-fusion proteins, which roughly presented N-terminal domain, central rod domain and C-terminal domain of BP230. By immunoblotting using these 3 recombinant proteins, we demonstrated that the majority of bullous pemphigoid sera reacted clearly with multiple recombinant proteins of BP230, most frequently with C-terminal domain. We also examined sera of pemphigus vulgaris, pemphigus foliaceus and herpetiform pemphigus that showed BP230-like protein band by immunoblotting of epidermal extracts, as well as paraneoplastic pemphigus, for reactivity with the 3 recombinant proteins. In the study, we found that only very few of these non-bullous pemphigoid sera reacted with some of the recombinant proteins. These results indicate that the BP230 is specifically reacted by bullous pemphigoid sera, and that the immunoblotting using the BP230 recombinant proteins should be a useful tool for the diagnosis of bullous pemphigoid.

Antibodies, Monoclonal↗

PubMed2001

A comparison of diagnostic accuracy of a newly developed photofluorographic panoramic system with conventional panoramic radiography.

OBJECTIVES: To compare the diagnostic accuracy of a prototype photofluorographic panoramic system with that of a conventional panoramic system. METHODS: We used 14 human skulls with four artificial apical bone defects in each and 13 clinical cases with 21 periapical lesions. Six dental radiologists and six senior dental students rated the presence of defects on each image on a five-point scale. Receiver Operating Characteristic (ROC) analysis was performed and the area under each curve (Az) was compared as an index of accuracy. Statistical significance was set at P<0.05. RESULTS: There were no significant differences between the photofluorographic and the conventional panoramic systems (P=0.074) in detecting artificial apical defects. However, there were significant differences (P=0.03) in detecting natural defects. CONCLUSIONS: The diagnostic accuracy of the prototype photofluorographic panoramic system appears comparable with that of the conventional panoramic system. However, variability may arise from the observers' diagnostic experience and training.

Alveolar Process↗

PubMed2001

Paraneoplastic pemphigus sera react strongly with multiple epitopes on the various regions of envoplakin and periplakin, except for the c-terminal homologous domain of periplakin.

Paraneoplastic pemphigus sera react with multiple plakin family proteins, among which only envoplakin and periplakin are constantly detected by immunoblotting using normal human epidermal extracts. Using bacterial expression vectors containing polymerase chain reaction-amplified cDNA, we have prepared variously truncated recombinant glutathione-S-transferase-fusion proteins of envoplakin and periplakin, which presented N-terminal, central and C-terminal domains of each protein, as well as the so-called C-terminal homologous domain of envoplakin and the junctional regions of these domains. By immunoblotting using these 11 recombinant proteins, we demonstrated that most of the 26 paraneoplastic pemphigus sera reacted very strongly with multiple recombinant proteins of envoplakin and periplakin, except for the C-terminal homologous domain of periplakin. We also examined the reactivity with these recombinant proteins of other blistering diseases, including pemphigus vulgaris, pemphigus foliaceus, and bullous pemphigoid, and found that a few nonparaneoplastic pemphigus sera showed a weak reactivity with some of the recombinant proteins. Interestingly, some sera showed relatively strong reactivity with the C-terminal homologous domain of periplakin to which paraneoplastic pemphigus sera reacted less frequently. These results indicate that, although nonparaneoplastic pemphigus sera occasionally show a weak reactivity with envoplakin and periplakin, the pathogenicity and the mechanism of antibody production in these cases may be different from those in paraneoplastic pemphigus.

Autoimmune Diseases↗

PubMed2001

Infection of human lung fibroblasts with Epstein-Barr virus causes increased IL-1beta and bFGF production.

An association between Epstein-Barr virus (EBV) infection and fibroblast proliferation in the interstitial spaces of the lung has been suggested in idiopathic interstitial pneumonia. In this study we show that EBV can infect human lung fibroblasts in vitro. A primary-cultured human lung fibroblast cell line, designated CCD-32Lu, expressed EBV nuclear antigen 1 after coculture with lethally irradiated EBV producing cells. The infection further induced CCD-32Lu cells to produce the fibrogenic cytokines basic fibroblast growth factor (bFGF) and interleukin-1beta. These findings indicate that lung fibroblasts may be a target for EBV infection and suggest that EBV may play a role in increased production of these cytokines and induce fibroblast proliferation in idiopathic interstitial pneumonia.

Antibodies, Blocking↗

PubMed2001

Non-Hodgkin's lymphoma of the ocular adnexa.

This study investigates the relationship between the clinical features of lymphoma in the ocular adnexal region and the revised European and American lymphoma (REAL) classification. Specimens from 41 patients with ocular adnexal lymphoproliferative disease were reassessed pathologically using the REAL classification. Thirty-two patients with primary non-Hodgkin's lymphomas (NHL) were included in the study, almost all of them having been treated with radiotherapy with or without chemotherapy. Seven of the 32 patients with NHL showed distant recurrence after treatment: 3 out of 26 with extranodal marginal zone B-cell lymphoma, and 4 with other types of NHL. Although the three patients with recurrent marginal zone B-cell lymphomas all survived, other patients with recurrent lymphomas died of disease. The REAL classification provides a good indication of tumor control probability and survival of patients with ocular adnexal NHL. Radiation therapy is an effective treatment modality for extranodal marginal zone B-cell lymphoma of the ocular adnexa.

Adult↗

PubMed2001

Continuous intra-jugular venous blood-gas monitoring with the Paratrend 7 during hypothermic cardiopulmonary bypass.

We measured the accuracy of the continuous intra-vascular blood-gas monitoring system (Paratrend 7, PT7) placed in the jugular venous bulb in 18 adult patients having cardiac or aortic surgery with hypothermic cardiopulmonary bypass (CPB). After induction of anaesthesia, a PT7 sensor was inserted through a 20-gauge venous catheter into the right jugular venous bulb. Blood samples were drawn from the venous catheter and measured with a blood gas analyser (BGA). Five to eight paired measurements using the PT7 and blood samples were made per patient, and bias and precision were calculated for each patient using the Bland-Altman method. The ranges for the blood sample measurements were: pH 7.12 to 7.59, PCO(2) 3.7 to 9.6 kPa, PO(2) 3.5 to 16.0 kPa, oxygen saturation 40 to 99%, bicarbonate 18.6 to 34.4 mmol l(-1), and base excess -7.8 to 12.5 mmol l(-1). Bias and precision values were 0.014/0.071 for pH, 0/0.90 kPa for PCO(2), and -0.16/1.18 kPa for PO(2). These values were comparable with those previously made on arterial blood. However, precision for oxygen saturation in each patient varied 2.3 to 23.6% (95% CI: 6.3 to 12.9%), which was unsatisfactory for clinical measurements. Deep hypothermia ( approximately 19.6 degrees C) and marked haemodilution ( approximately 13.5%) during CPB did not influence the reliability of the PT7 sensor. Thus, we concluded that continuous intra-jugular venous blood-gas monitoring is clinically feasible using the PT7 and may provide valuable information during CPB.

Adult↗

PubMed2001

Concurrent chemoradiotherapy for oropharyngeal carcinoma.

The clinical results of definitive chemoradiotherapy for oropharyngeal carcinoma were retrospectively analyzed. Thirty-one patients with oropharyngeal carcinoma who received definitive radiation therapy between January 1986 and June 1998 were analyzed. The median age was 61 years. All patients had squamous cell carcinoma. According to the Union International Contre le Cancer 1997 classification system, stage I, II, III, IVA, and IVB were 1,0, 9, 14, and 7, respectively. Regarding the primary site, 23 tumors were in the lateral wall, whereas 2 were in the superior wall, and 3 each were in the anterior and posterior walls. The median total dose was 66 Gy, with a range of 60 Gy to 74.4 Gy. The overall treatment time ranged from 39 days to 113 days, with a median of 50 days. Seven patients underwent hemilateral radical neck dissection. Fourteen patients received concurrent chemotherapy using weekly cisplatin (50 mg/d) at least three times. The 5-year overall and cause-specific survival (CSS) rates were 55% and 62%, respectively. All local recurrences occurred within 2 years. The CSS rate in patients with lateral or superior wall origin was significantly superior to that of patients with anterior or posterior wall origin (p < 0.05). The 3-year CSS rate was 83% for patients treated with concurrent chemoradiotherapy using weekly cisplatin at least 3 times, whereas that was 53% for the remaining patients (p < 0.05). No serious adverse effects were observed. It is concluded that definitive concurrent chemoradiotherapy using weekly cisplatin for oropharyngeal carcinoma appear promising.

Adult↗

PubMed2001

Protective effects of FK409, a novel nitric oxide donor, against postischemic myocardial dysfunction in guinea-pig hearts.

Effects of FK409 were investigated in perfused guinea-pig Langendorff hearts subjected to ischemia and reperfusion. Nitric oxide electrode, fluorometry, and 31P nuclear magnetic resonance imaging were used to monitor changes in cellular high-phosphorous energy and nitric oxide and Ca2+ content in the heart together with simultaneous recordings of left ventricular developed pressure. After cardioplegic arrest with St. Thomas' Hospital solution, normothermic (37 degrees C) global ischemia was induced for 40 min, and hearts were reperfused for 40 min. FK409 at 10(-8) M, which has a minimum inotropic effect on nonischemic hearts, was added to the cardioplegic solution. Treatment with FK409 reduced left ventricular developed pressure during and after ischemia and improved postischemic recovery of left ventricular developed pressure from 55.4% at 40 min of reperfusion in FK409-free hearts up to 80.4% in hearts treated with FK409 (p < 0.01). Flow rate at 1.5 min after treatment with the cardioplegic solution was 27.7 ml/min in hearts treated with FK409 compared with 21.2 ml/min in drug-free hearts (p < 0.01). Treatment with FK409 significantly effected preservation of tissue level of beta-adenosine triphosphate at the end of ischemia or reperfusion. During ischemia, arrested with the cardioplegic solution, intracellular Ca2+ accumulation and nitric oxide release were reduced. At the end of ischemia in FK409-treated hearts, nitric oxide release was 86% greater than in drug-free hearts without reference to the Ca2+ concentration. In cardiac surgery, normothermic arrested hearts are subject to damage by oxygen free radicals in reperfusion injury. Therefore, nitric oxide exogenously supplied by FK409 was responsible for the cardioprotective action, presumably by acting directly as an oxygen radical scavenger during reperfusion. A specific nitric oxide donor, like FK409, may have therapeutic use as a nitric oxide-mediated vasorelaxant and additional protective action for reperfusion-injury hearts.

Actin Cytoskeleton↗