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Biomedical subjects

S Suzuki

Publications and source records attributed to S Suzuki.

At least 253 records · Page 14Linked to original sources
PubMed2001

Isolated unilateral absence of a pulmonary artery: influence of systemic circulation on alveolar capillary vessels.

We report a case of isolated unilateral absence of a pulmonary artery. The first clinical symptom that was manifested in the patient was recurrent hemoptysis, and subsequent angiography revealed that the main pulmonary artery was absent in the right lung, which was being fed only from the systemic circulation. Right pneumonectomy was performed, and neither the main pulmonary artery nor its remnant was detected in the resected right lung. Histologically, there were many muscular vessels in the resected lung, with intimal proliferation, or with plexiform-like lesions. The alveolar septum was moderately thickened and alveolar capillary vessels were dilated. We examined the alveolar capillary endothelial cells of the resected lung for immunoreactivity to thrombomodulin (TM) and von Willebrand factor (vWF). The endothelial cells were negative for TM and positive for vWF, while in the normal lung control group, these cells were positive for TM and negative for vWF. We considered that the hemodynamics of the systemic circulation in the resected lung caused the alteration of immunohistochemical characteristics in alveolar capillary endothelial cells.

Adult↗
PubMed2001

A prospective clinical study on inhaled nitric oxide therapy for neonates in Japan.

BACKGROUND: This is the first report about a prospective clinical investigation to study the efficacy and safety of nitric oxide (NO) inhalation in infants with persistent pulmonary hypertension of the newborn (PPHN) in Japan. METHODS: Patients in the present study had to meet the following entry criteria: (i) they had to be younger than 7 days of age; (ii) they had to have evidence of PPHN as defined by echocardiograph; (iii) they had to have severe systemic hypoxemia under mechanical ventilation at 100% oxygen supplementation; and (iv) they had to have a failure to respond to conventional therapies. Patients were excluded from this trial if they had any of the following: hypoplastic lung, structural cardiac lesions or severe multiple anomalies. RESULTS: Nitric oxide inhalation therapy was performed in 68 infants who had severe PPHN at 18 hospitals between May 1995 and May 1997. At birth, 21 of 68 infants (31%) weighed less than 1,500 g and 39 infants weighed more than 2,500 g. The diagnoses associated with PPHN were as follows: 27 infants had meconium aspiration syndrome, 15 infants had dry lung syndrome, nine infants had congenital diaphragmatic hernia, six infants had respiratory distress syndrome, three infants had pneumonia and eight infants had other diagnoses. The mean oxygenation index (OI) before NO inhalation therapy in 68 infants was 43.2; 55 infants (81%) had good responses. CONCLUSIONS: These results may be valuable for further randomized controlled and double-blind trials in Japan to evaluate whether NO inhalation therapy is more effective than conventional therapy in infants with severe PPHN.

Administration, Inhalation↗
PubMed2001

Nitric oxide inhalation and nitric oxide synthase inhibitor supplement for endotoxin-induced hypotension.

BACKGROUND: This study was performed to determine whether a combined therapy of nitric oxide (NO) inhalation and nitric oxide synthase (NOS) inhibitor is effective in experimental animals with endotoxin-induced refractive hypotension accompanied by pulmonary hypertension. METHODS: Escherichia coli lipopolysaccharide (1 mg/kg) was administered to 10 newborn piglets to induce endotoxemia. The experiment then began 60 min later, when the systemic arterial pressure dropped. The inhalation of 20 p.p.m. NO at 60 and 120 min of endotoxemia created a control group. Another group was also administered N w-nitro-L-arginine (L-NNA; 5 mg) after the first NO inhalation at 60 min of endotoxemia (the L-NNA group). Pulmonary arterial pressure, systemic arterial pressure and cardiac output were measured and compared among the groups. RESULTS: Three of the 5 piglets in the control group died of hypotensive shock, while in the L-NNA group the systemic arterial pressure recovered to pre-endotoxin administration levels. The L-NNA group produced a further increase in pulmonary arterial pressure against which NO inhalation was effective. CONCLUSION: Nitric oxide inhalation alone carries a potential risk of further lowering systemic arterial pressure in a piglet with hypotension induced by endotoxin, whereas the combined therapy resulted in the recovery of the blood pressure to pre-endotoxin levels. The combined therapy was simultaneously effective against pulmonary hypertension.

Animals↗
PubMed2001

Suicide gene therapy on LNCaP human prostate cancer cells.

The efficacy of combination suicide gene therapy was evaluated using a Herpes simplex virus-thymidine kinase/ganciclovir (HSV-TK/GCV) system and an Escherichia coli cytosine deaminase/5-fluorocytosine (CD/5-FC) system on the LNCaP human prostate cancer cell model. Two types of plasmid vectors with the HSV-TK gene were constructed. A constitutive chicken beta-actin promoter drove one and a prostate-specific antigen (PSA) promoter drove the other. Similarly, a pair of plasmids with the CD gene under a cytomegalovirus (CMV) promoter and the PSA promoter was also constructed. LNCaP cells were transfected in vitro with either or both of those plasmids using a cationic lipid reagent. Transfected cells were treated with GCV and/or 5-FC. The percentage of viable LNCaP cells 7 days after treatment with HSV-TK/GCV or CD/5-FC under a constitutive promoter was 40% and 41% of controls, respectively. The cell viability when two suicide genes were combined was 23%. The cell viabilities after four days with PSA promoter-HSV-TK vectors, CD vectors and a combination of both were 79%, 88% and 88%, respectively. Suicide gene therapy using either HSV-TK/GCV, CD/5-FC, or both, was effective in the LNCaP model. An additive effect was observed when the two suicide genes were used together. The PSA promoter did not seem to be effective enough to elicit cytotoxicity under the experimental conditions used here.

Antimetabolites↗
PubMed2001

Helicobacter pylori-mediated transcriptional regulation of the human beta-defensin 2 gene requires NF-kappaB.

Human beta-defensin 2 (hBD-2) is an antimicrobial peptide involved in host defence against bacterial infection in epithelial tissues. Its levels are dramatically increased after bacterial infection. The involvement of NF-kappaB in Helicobacter pylori-mediated induction of hBD-2 promoter activity was examined. A luciferase reporter plasmid containing the hBD-2 promoter extending from -2110 base pairs to -1 was transiently expressed in MKN45 cells, and promoter activity was determined after incubation with H. pylori for 6 h. Deletion or mutation of the NF-kappaB site at -208 abolished activation of the hBD-2 promoter. Only H. pylori strains carrying a cag pathogenicity island (PAI) induced activation of the NF-kappaB site of the hBD-2 promoter gene. By gel retardation analyses, H. pylori increased NF-kappaB binding to hBD-2 promoter gene sequences. Supershift analysis demonstrated that whereas H. pylori activated NF-kappaB p65-p65 and p50-p50 homodimers, and the p65-p50 heterodimer of NF-kappaB, only the p65-p65 homodimer bound to the NF-kappaB site of the hBD-2 promoter. Thus, specific NF-kappaB proteins are important cis-elements for induction of hBD-2 gene transcription by H. pylori.

Cell Line↗
PubMed2001

Effect of troglitazone on urinary albumin excretion and serum type IV collagen concentrations in Type 2 diabetic patients with microalbuminuria or macroalbuminuria.

AIMS: Troglitazone, a newly developed thiazolidinedione derivative, has been shown to ameliorate microalbuminuria in diabetic animal model and in human diabetic nephropathy in short-term studies. The aim of the present study was to determine whether troglitazone or sulphonylurea affect micro- albuminuria, macroalbuminuria, or serum type IV collagen concentrations in patients with diabetic nephropathy. METHODS: We studied 32 normotensive patients with type 2 diabetes mellitus associated with microalbuminuria (n = 16) or macroalbuminuria (n = 16) and 20 healthy controls. The patients were randomly assigned to one of two groups: those treated with glibenclamide (5.0 mg/day) (n = 8) and those treated with troglitazone (400 mg/day) (n = 8). They received the drug regimen for 12 months. Serum type IV collagen was measured with sandwich enzyme immunoassay. RESULTS: Type IV collagen concentrations in macroalbuminuric patients were higher than those in microalbuminuric patients (P < 0.05) and healthy controls (P < 0.01). Troglitazone reduced urinary albumin excretion (UAE) in micro-albuminuric patients from 126 microg/min (range 58--180 microg/min) to 42 microg/min (range 14--80 microg/min) (P < 0.01) and also reduced serum type IV collagen levels gradually at 3, 6 and 12 months after treatment (P < 0.05). However, glibenclamide did not affect UAE and type IV collagen levels in micro- albuminuric diabetes patients. In addition, neither troglitazone nor gliben- clamide changed UAE and type IV collagen levels in macroalbuminuric patients. CONCLUSIONS: These data suggest that troglitazone is an effective treatment for renal injury in patients with early diabetic nephropathy.

Albuminuria↗
PubMed2001

Histochemical localisation of versican, aggrecan and hyaluronan in the developing condylar cartilage of the fetal rat mandible.

We investigated the histochemical localisation of versican, aggrecan and hyaluronan in the developing condylar cartilage of the fetal rat mandible at d 15-17 of gestation. At d 15 of gestation, immunostaining for versican was detected in the anlage of the future condylar process (condylar anlage), although the staining intensity showed a considerable regional variation. At d 16 of gestation, a metachromatically stained matrix firstly appeared in the condylar anlage. Aggrecan, hyaluronan and versican were simultaneously detected in this newly formed condylar cartilage. At d 17 of gestation, immunostaining for versican became restricted to the perichondrium and was barely detected in the cartilage. Colocalisation of versican and aggrecan was also seen in the cranial base cartilage at d 14 of gestation. These results indicate that although versican is replaced by aggrecan during the transition from prechondrogenic tissue to cartilage, both molecules were temporally colocalised in the newly formed cartilage. A hyaluronan-rich, low-versican area was identified in the posterior end of the condylar anlage during d 15-17 of gestation. The existence of this area is a unique structural feature of the developing condylar cartilage.

Aggrecans↗
PubMed2001

Glutathione S-transferase Pi is a dopamine-inducible suppressor of dopamine-induced apoptosis in PC12 cells.

The finding that the neurotransmitter dopamine induces apoptosis in neurons implies the existence of a cellular mechanism by which dopaminergic neurons protect themselves from dopamine-induced apoptosis. By profiling the expression of a number of genes in differentiating PC12 cells which exhibit elevated levels of dopamine biosynthesis, we found that expression of glutathione S-transferase class Pi (GSTp) mRNA was selectively up-regulated. Interestingly, dopamine added to the culture medium of PC12 cells also augmented their expression of GSTp mRNA. Suppression of GSTp expression by transfection of its antisense expression vector augmented dopamine-induced apoptosis of PC12 cells. Conversely, overexpression of GSTp made the resultant PC12 transfectants highly resistant to dopamine-induced apoptosis. Transfection of the antisense or sense GSTp expression vectors also resulted in corresponding augmentation or suppression of dopamine-induced activation of cell-associated Jun-N-terminal kinase (JNK), which has been suggested to mediate dopamine-induced apoptosis in neuronal cells. These results indicate that GSTp is a dopamine-inducible suppressor of dopamine-induced apoptosis in PC12 cells, and suggest that this activity is exerted through inhibition of JNK activity.

Animals↗
PubMed2001

Midterm results of stent-graft repair for thoracic aortic aneurysms: computed tomographic evaluation.

Midterm observation of endovascular surgery using a fabric-covered stent graft for thoracic aortic aneurysms is discussed with postoperative follow-up findings based on regularly performed thoracic computed tomography (CT). From 1996 to 1999, 20 patients with thoracic aortic aneurysm underwent stent-graft placement in our hospital. One year follow-up CT results after placement were obtained for 17 patients. The CT scans found that there were both thrombosis and size reduction of aneurysm in 8 patients (46%), thrombosis without size reduction in 2 (13%), a new ulcerlike projection (ULP) in 3 (19%), persistent minor endoleakage in 2 (13%), a new endoleak in 1 (6%), and a recurrent endoleak from intercostal arteries in 1 (6%). The new ULP formation seemed to be a peculiar problem stemming from an intimal injury caused by edges of the stent. Therefore, we recently adopted a new spiral stent instead of the previous stent to avoid the injury. The new endoleak suggested that aneurysmal thrombosis without size reduction could cause the aneurysm to develop recurrent endoleaks. From these findings, we concluded that midterm observation of stent-graft repair for thoracic aortic aneurysms did not give satisfactory results. In order to improve the results of endovascular surgery using stent-grafts, we need to develop safer stent grafts with a reliable design to prevent endoleaks and to avoid intimal injury of the aorta. We also hope to develop effective technologies that can accelerate organization of thrombus in the aortic aneurysm after stent-graft placement.

Adult↗
PubMed2001

Cerebrospinal fluid and serum neuron-specific enolase levels after febrile seizures.

PURPOSE: Neuron-specific enolase (NSE) has been established as a reliable marker of neuronal damage in various neurologic disorders. The aim of this study was to evaluate whether febrile seizures (FS) cause brain damage, based on the serum and cerebrospinal fluid (CSF) levels of NSE. METHODS: Fifty-three patients aged from 6 months to 7 years were enrolled. Among them, 36 patients had generalized seizures, and 17 had partial seizures. The maximal seizure duration was 90 min. Blood and CSF samples for measurement of NSE were obtained immediately after the seizure. NSE was measured using an enzyme immunoassay (EIA). RESULTS: Serum and CSF levels of NSE ranged up to 10 ng/mL, but very high levels were not observed. In patients with partial seizures, the NSE level in the CSF and the ratio of the CSF to serum NSE levels showed a strong correlation with seizure duration. Conversely, there were no correlations between NSE levels and seizure duration in the patients with generalized seizures. CONCLUSIONS: These results indicate that FS seldom cause severe neurologic damage, but prolonged partial seizures may cause slight neuronal injury.

Biomarkers↗
PubMed2001

Cholesteryl ester transfer protein as a protective factor against vascular disease in hemodialysis patients.

Cholesteryl ester transfer protein (CETP) may promote reverse cholesterol transport. An elevated concentration of high-density lipoprotein cholesterol (HDL-C) is a protective factor against atherosclerosis. However, the effects of CETP itself and its interaction with HDL-C have not been investigated in hemodialysis patients, who are at high risk for atherosclerosis and generally considered to have decreased reverse cholesterol transport. We investigated the independent or synergistic influence of postprandial serum CETP and HDL-C concentrations on apparent atherosclerotic complications in 202 hemodialysis patients aged 40 to 80 years. Patients with vascular disease (n = 39) had significantly lower concentrations of CETP than those without vascular disease (n = 163). When all study subjects were divided into four groups according to CETP and HDL-C concentrations based on median values, we found significant differences in the prevalence of vascular disease (test for trend, P < 0.005): 28.8% in group I (HDL-C < 48 mg/dL; CETP < 2.2 microgram/mL); 25.0% in group II (HDL-C < 48 mg/dL; CETP >/= 2.2 microgram/mL); 17.8% in group III (HDL-C >/= 48 mg/dL; CETP < 2.2 microgram/mL); and 6.9% in group IV (HDL-C >/= 48 mg/dL; CETP >/= 2.2 microgram/mL). Multiple logistic regression analysis retained the interaction term between HDL-C (in milligrams per deciliter) and CETP (in micrograms per milliliter), but not HDL-C or CETP itself, as inversely associated with vascular disease in the entire patient group. In patients with HDL-C levels at the median value or greater, CETP had an independent odds ratio of 0.31 (95% confidence interval, 0.1 to 0.97; P < 0.05) after adjusting for age. These results suggest that CETP may serve as a protective factor against vascular disease in hemodialysis patients, especially those with normal or elevated HDL-C concentrations.

Adult↗
PubMed2001

Arthroscopic treatment for traumatic hip dislocation with avulsion fracture of the ligamentum teres.

Traumatic hip dislocation in children is a rare condition. Immediate closed reduction is a treatment of choice, but when incongruent reduction results, it can be due to interposition and requires open arthrotomy. We present a previously unreported technique of arthroscopic treatment that was used successfully for traumatic hip dislocation in a 10-year-old girl with impingement of the avulsed ligamentum teres. Arthroscopy was effective in confirming the exact nature of the interposition material and excising the fragment with minimal invasion.

Arthroscopy↗
PubMed2001

Eyelid reconstruction using a hard palate mucoperiosteal graft combined with a V-Y subcutaneously pedicled flap.

Full-thickness eyelid defects after tumour ablation require the reconstruction of two layers, the anterior and posterior lamellae. Eyelids were successfully reconstructed after removal of malignant tumours in four patients using a hard palate mucoperiosteal graft combined with a curved V-Y subcutaneously pedicled flap. Although there have been some reports of hard palate mucosal grafts for reconstruction of the posterior lamella, the graft is not sufficiently rigid to support the reconstructed eyelid without the aid of supporting materials such as cartilage grafts. The hard palate mucoperiosteal graft seems to be rigid enough to support the reconstructed eyelid without the use of cartilage or other supporting materials. The subcutaneously pedicled V-Y advancement flap is useful for reconstruction of the anterior lamella in partial eyelid defects. We used it with a modified curved design to allow easy advancement and to make postoperative scars inconspicuous.

Basal Cell Carcinoma↗
PubMed2001

Pituitary tumours in adolescence: clinical behaviour and neuroimaging features of seven cases.

The clinicopathologic features of seven paediatric patients with pituitary adenomas (2 male, 5 female; mean age 14.3 years) were reviewed. There were three non-functioning adenomas, three prolactinomas, and one growth hormone producing adenoma. Five patients presented with visual field deficits, and six patients had endocrine symptoms, which included menstrual irregularities in all female patients, pubertal delay in two females, and growth delay and gigantism in one case each. On neuroimaging studies, five adenomas showed parasellar extension, while the remaining two prolactinomas were intrasellar microadenomas. While two patients with prolactinomas received good results with bromocriptine treatment alone, the remaining five patients underwent either craniotomy or transsphenoidal surgery. Postoperatively, visual disturbances improved markedly in all patients. Two patients also received replacement hormonal therapy. While six patients have been stable for 3.6 years on average, one non-functioning tumour recurred 2 years after the initial transcranial subtotal resection of the tumour. Although there are still many unknowns concerning the biology and optimal treatments for paediatric pituitary adenomas, many of them are assumed to be relatively rapidly growing tumours, while others merely have an earlier tumour genesis than in adults.

Adolescent↗
PubMed2001

Subependymal giant cell astrocytoma: clinical and neuroimaging features of four cases.

The clinical history, neuroimaging features, treatments, and outcome of 4 patients with histologically verified subependymal giant cell astrocytomas (SEGA) were retrospectively reviewed. The average age at the time of surgery was 13.3 years. Headache related to raised intracranial pressure was the first and only sign in 2 patients, with the remaining 2 being admitted because of sequential neuroimaging studies over several years revealing the growth of 'subependymal nodules' into intraventricular tumours. In each case the tumour was in the region of Monro's foramen and was associated with ventricular dilatation. On computed tomography (CT), multiple subependymal nodules were found in 3 patients, and these well circumscribed isodense SEGAs were markedly enhanced by contrast medium. On magnetic resonance imaging (MRI), which was obtained in 3 patients, 2 SEGAs were isointense with the cerebral cortex and one with the white matter on T1-weighted images, and on T2-weighted images, 2 were isointense with the cortex and one with the white matter. At surgery the tumours appeared to originate from the inferolateral wall of the lateral ventricle in the region of the head of the caudate nuclei. Total macroscopic removal was achieved in 3 patients, and subtotal removal in one patient. Follow up ranged from 4.6 to 13.2 years, and all patients have exhibited similar physical and mental conditions to preoperative. So far there has been no evidence of any recurrences. The diagnosis and the surgical indications for SEGA are discussed, with periodic monitoring with neuroimaging studies being recommended even for asymptomatic patients with 'subependymal nodules'.

Adolescent↗
PubMed2001

Secretory meningioma: clinicopathologic features of eight cases.

The clinical and morphological features of eight patients with meningothelial meningiomas with numerous pseudopsammoma bodies (secretory meningiomas) are presented. The six female and two male patients ranged in age from 43 to 68 years. Tumours were located at the petroclival region in two, the lateral parasellar region in two, the petrous apex in one and the sphenoid ridge in three patients. On magnetic resonance imaging, they were iso or hypointense on T1-weighted images, and hyper or isointense on T 2-weighted images. Peritumoral brain edema was absent in five cases, and was mild to moderate in three cases. Serum carcinoembryonic antigen (CEA) levels were measured preoperatively in three patients, with one having an elevated serum CEA level which re turned to normal following tumour resection. Immunohistochemical analysis on the resected tumour tissues, pseudopsammoma bodies and surrounding tumour cells were shown to be CEA-positive. Ultrastructurally, pseudopsammoma bodies were composed of granular and filamentous materials located predominantly in the intracellular lumina, which were lined by microvilli. While these morphological features of focal epithelial and secretory differentiation of tumour cells call attention to the broad spectrum of differentiation properties of meningiomas, the biological behavior of the eight tumours reported herein corresponded to those of meningiomas in general.

Adult↗