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Biomedical subjects

M Haga

Publications and source records attributed to M Haga.

At least 19 recordsLinked to original sources
PubMed2004

Venous blood flow through vein grafts before harvesting minimizes endothelial cell desquamation immediately after implantation.

AIM: The aim of this paper was to examine effectiveness of maintaining venous blood flow through dissected, but not harvested, grafts on prostaglandin I2 production and endothelial cell regeneration after implantation. METHODS: Using 10 dogs, 8-cm-long bilateral jugular veins were dissected; 1 was harvested, and immersed in heparinized blood for 60 or 120 min. The other was left in situ with retained blood flow until harvest after 60 or 120 min. Two 1-cm-long specimens were obtained from these 4 graft types and subjected to PGI2 assay or silver nitrate staining for measurement of endothelial cell coverage area. The remaining 6-cm portions of the 120-min grafts were autogenously implanted into the abdominal aorta, retrieved after 7 days and assayed and measured. RESULTS: Comparisons between groups suggested beneficial effects of preserving venous blood flow until implantation on endothelial coverage and PGI2 production (p<0.05). CONCLUSION: Venous blood flow through dissected vein grafts effectively helps preserve PGI2 production.

Animals↗
PubMed2003

[Venovenous extracorporeal membrane oxygenation in neonatal systemic artery-to-pulmonary artery shunt operations using a double lumen catheter].

The right atrium of the neonate may be too small for direct insertion of 2 venous catheters during intraoperative life support. We inserted a double lumen catheter into the right atrium, and venovenous (V-V) extracorporeal membrane oxygenation (ECMO) was instituted. The patient's arterial oxygen saturation was maintained at 70% to 90%, and hemodynamic stability was obtained during V-V ECMO. V-V ECMO using a double lumen catheter can be easily established in a small neonate, and is an effective support technique for untolerable hypoxemia during systemic-to-pulmonary artery shunt operations.

Brachiocephalic Trunk↗
PubMed2001

Evaluation of an internal thoracic artery as a coronary artery bypass graft by intercostal duplex scanning ultrasonography.

OBJECTIVES: Although angiography is often used to determine whether the internal thoracic artery is appropriate as a coronary bypass graft, but use of duplex scanning ultrasonography for this purpose is not yet widespread. METHODS: The internal diameter and flow of the internal thoracic artery were measured using intercostal duplex scanning in 100 patients during April 1995. The ultrasonographic device (sonos 2000, Hewlett Packard) used had a linear probe delivering a frequency of 7.5 MHz. Bilateral internal thoracic arteries and their blood flow were imaged clearly in all subjects. Diameter was compared by angiography and duplex scanning ultrasonography in 20 patients. RESULTS: The average internal diameter of internal thoracic artery was 2.19 +/- 0.46 mm (right) or 2.13 +/- 0.32 mm (left) in men and 2.05 +/- 0.44 mm (right) or 2.09 +/- 0.42 mm (left) in women. The gender difference was statistically significant (p = 0.05). The maximum systolic blood flow velocity through the internal thoracic artery was 0.85 +/- 0.34 m/s (right) or 0.84 +/- 0.36 m/s (left) in men and 0.87 +/- 0.28 m/s (right) or 0.82 +/- 0.28 m/s (left) in women. The average internal thoracic arterial blood flow (F) was 54.6 +/- 29.0 ml/min (right) or 50.9 +/- 28.8 ml/min (left) in men and 56.8 +/- 38.2 ml/min (right) or 58.2 +/- 33.4 ml/min (left) in women. Duplex scanning ultrasonography using an intercostal approach enables easy imaging of bilateral internal thoracic arteries and visualizes entire internal thoracic artery structure by simply changing the probe position. CONCLUSION: Intercostal duplex scanning ultrasonography is thus recommended for reliable evaluation of the internal diameter and blood flow of the internal thoracic artery.

Aged↗
PubMed2001

Systemic lupus erythematosus and the risk of malignancy.

The objective of this study was to determine the relative risks of malignancy and of site-specific malignancies in patients with systemic lupus erythematosus (SLE). A cohort of 297 patients (91% Caucasian) with SLE were seen between 1975 and 1994 and followed for a mean of 12 years at the University of Saskatchewan Rheumatic Disease Unit. Expected cancer incidence rates were determined based on Province of Saskatchewan population statistics matched to each study patient for age, sex and calendar year of follow-up. Standardized incidence ratios (SIRs) of observed to expected cancers and 95% confidence intervals (95% CI) were calculated. A total of 27 cases of cancer were observed, whereas only 16.9 were expected (SIR 1.59 (95% CI 1.05-2.32)). For site-specific malignancies, an excess of cancer of the cervix (SIR 8.15 (95% CI 1.63-23.81)) as well as hemopoietic malignancy (SIR 4.9 (95% CI 1.57-11.43)) was found. The hemopoietic cancers were predominantly non-Hodgkin's lymphoma (SIR 7.01 (95% CI 1.88-17.96)). We did not find an association of malignancy with known risk factors, including use of cytotoxic agents. Increased risk of malignancy, notably non-Hodgkin's lymphoma and perhaps cervical cancer, should be regarded as a complication of SLE.

Adolescent↗
PubMed2001

Active oxygen radicals induce peroxidase activity in rice blade tissues.

The relationship between active oxygen radicals and peroxidase induction on disease resistance in rice blades was investigated. Nitric oxide was produced in the whole blade stimulated by blast fungus elicitor. The induction of peroxidase activity was detected in active oxygen radical-treated rice blades 1 hour after treatment and thereafter. These results suggest that active oxygen radicals produced by stimulation with the elicitor could trigger peroxidase induction.

Enzyme Induction↗
PubMed2001

[Determination of 4-O-methylpyridoxine (MPN) by HPLC with diode-array detector].

We have developed a simple and rapid method for measuring 4-O-methylpyridoxine (MPN) in the serum of an acute poisoning patient by high-performance liquid chromatograph (HPLC) with a diode-array detector. MPN, a poisonous ingredient of ginkgo seeds was extracted using an Isolute C18 solid-phase extraction column. Equal volumes of the extract were injected into a C18 HPLC column using acetonitrile-10 mM phosphate buffer (pH 3) as the mobile phase. Excellent linearity was obtained over the range of 1-1000 ng at a wavelength of 290 nm, and its detection limit of approximately 0.5 ng was considered to be satisfactory. The mean recovery of MPN in the serum was 92.9 +/- 6.1%. The method was used successfully in a case of acute poisoning.

Chromatography, High Pressure Liquid↗
PubMed2001

Radiographic damage in rheumatoid arthritis correlates with functional disability but not direct medical costs.

OBJECTIVE: Few longitudinal data exist on the relationship between radiographic damage and self-reported functional disability and direct medical costs in rheumatoid arthritis (RA). We assessed these relationships. METHODS: One hundred thirty patients with RA (at time of the first available radiograph, mean age 56.6 yrs, 16.9% male, mean disease duration 16.8 yrs) were followed for up to 13.4 years. Semiannually, they reported on functional disability (0 = no difficulty, 3 = unable to do), global severity (0 = very well, 100 = very poor), pain (0 = no pain, 3 = severe pain), and health services utilization through completion of the Stanford Health Assessment Questionnaire (HAQ). Concurrent hand radiographs were scored for erosions and joint space narrowing using the Genant method and a single score summing both erosions and joint space narrowing for both hands was calculated (0 = no damage, 200 = maximum damage). The univariate association of functional disability, global severity, pain, or direct medical costs with concurrent radiographic damage was assessed through Spearman correlations and hierarchical regression models. The hierarchical models permit exploitation of the between-patient and within-patient variation present in our longitudinal data. RESULTS: At the time of the first available radiograph, mean (SD) levels of functional disability, global severity, and pain were 1.3 (0.7), 39.4 (21.0), and 1.1 (0.7), respectively. At entry into the study, the average radiograph score was 49.7 and upon leaving the study it was 66.9. Patients were followed an average of 6.7 years, with radiograph scores increasing at an average rate of 2.5 units/yr. The Spearman correlation [95% confidence interval (CI)] between average per-patient radiograph score and average per-patient HAQ disability index, average per-patient global severity, average per-patient pain score, and average per-patient direct medical costs was, respectively, 0.42 (0.26, 0.55), 0.23 (0.06, 0.39), 0.20 (0.03, 0.36), and 0.06 (-0.11, 0.23). The mean slope (95% CI) for disability on radiograph score was 0.0186 (0.0132, 0.0226), for severity on radiographs 0.1889 (0.1295, 0.2498), and for pain on radiographs 0.0057 (0.0027, 0.0084). As an example, over 10 years, a 25 unit (i.e., 50%) increase in radiograph scores would, on average, be associated with a 0.46 unit (i.e., 35%) increase in disability, a 4.72 unit (12%) increase in global severity score, and a 0.14 unit (13%) increase in pain, all expressed on the HAQ scales. There was little association between radiograph score and direct medical costs. CONCLUSION: A clinically meaningful association exists between radiographic damage and self-reported functional disability, suggesting that interventions that slow radiographic progression may improve the patient's health status. Such a relationship was not observed between radiographic damage and direct medical costs.

Aged↗
PubMed2000

Ionotropic glutamate receptors expressed in human retinoblastoma Y79 cells.

Mammalian retinal photoreceptors and pinealocytes have common characteristic that they secrete melatonin and L-glutamate as chemical transmitters. Although pinealocytes express glutamate receptors and receive glutamate signals, whether or not photoreceptors express glutamate receptors is unknown. Here, we investigated the expression of the glutamate receptors in cultured Y79 clonal human retinoblastoma cells, as model systems of photoreceptors. Reverse transcription-polymerase chain reaction (RT-PCR) analysis indicated that GluR1, GluR5, GluR7, EAA2, NR1, NR2A and NR2D mRNAs were present in the cultured cells. Northern analysis confirmed the presence of GluR7, EAA2, NR1, NR2A and NR2D mRNAs, while other mRNAs were under the detection limit. Addition of (RS)-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid or kainate increases intracellular (Ca(2+)) in Fura-2 loaded cells, which is blocked by 6-cyano-7-nitroquinoxaline-2,3-dione. N-methyl-D-aspartate also increases intracellular (Ca(2+)). These results demonstrated the presence of functional ionotropic receptors in Y79 cells.

6-Cyano-7-nitroquinoxaline-2,3-dione↗
PubMed2000

[Children and motor competence].

Recently, the topic of motor competence has figured prominently in the media. The claims made are many, but the research that support the statements is seldom cited. The aim of this review article is to address that deficiency by documenting what is really known about the motor competence of children. Motor competence not only allows children to carry out everyday practical tasks, but it is also an important determinant of their level of self-esteem and of their popularity and status in their peer group. While many studies have shown a significant correlation between motor problems and other problems in the social sphere, it has been difficult to establish causal relationships with any degree of confidence, as there appear to be several interactions which need to be taken into account. Research has shown that 6-10% of Norwegian children in the 7 to 10 year age group have a motor competence well below the norm. It is unusual for motor problems to simply disappear over time. In the absence of intervention the syndrome is likely to continue to manifest itself. More recent research points to some of the circularity in this causal network, children with motor problems having been shown to be less physically active than their peers. In a larger health perspective this in itself can have very serious consequences for the child.

Child↗
PubMed2000

Luminescent Langmuir-Blodgett films of platinum(II) complex [Pt(L18)Cl](PF6) (L18 = 2,6-bis(1-octadecylbenzimidazol-2-yl)pyridine).

A novel amphiphilic Pt complex containing 2,6-bis(1-octadecylbenzimidazol-2-yl)pyridine (L18), [Pt(L18)Cl](PF6), has been synthesized. The complex exhibits concentration-dependent absorption and emission spectra in solution. With increasing the concentration of the Pt complex, we observed a new absorption band centered at 550 nm derived from a metal-metal d sigma* to ligand pi* charge transfer (MMLCT) transition and the corresponding broad emission centered at 650 nm. The Pt complex is surface-active, and the surface pressure-area isotherm reveals three phase transitions. The three phases correspond to one liquid-expanding phase and two solid-condensed phases, respectively, with different intermolecular overlap in the "flat-on" orientation at the air-water interface. Without additives such as fatty acids, the complex forms a stable and reproducible Langmuir-Blodgett (LB) multilayer film above a surface pressure of 15 mN m-1. Strong emission from the LB films, even monolayer, was observed. Comparing the relative emission intensity of the MMLCT band for transferred LB monolayer film with that for cast films, we concluded that Pt-Pt interactions are suppressed in the LB film. Instead, the emission at 600 nm arising from the ligand-ligand pi-pi interacted excited state became dominant. The results would provide the insight into the control of molecular ordering for planar Pt complexes from the viewpoint of characteristic excited states.

Journal Article↗
PubMed2000

Bilobalide prevents reduction of gamma-aminobutyric acid levels and glutamic acid decarboxylase activity induced by 4-O-methylpyridoxine in mouse hippocampus.

We previously reported that bilobalide, a constituent of Ginkgo biloba L. leaves, protected mice against convulsions induced by 4-O-methylpyridoxine (MPN). To elucidate the mechanism of the anticonvulsant activity of bilobalide, this study examined the effect of bilobalide on MPN-induced changes in the levels of gamma-aminobutyric acid (GABA) and glutamate, and in the activity of glutamic acid decarboxylase (GAD) in the hippocampus, cerebral cortex and striatum of the mouse. GABA levels and GAD activity in the hippocampus and cerebral cortex were significantly enhanced by bilobalide treatment (30 mg/kg, p.o., for 4 days) alone. MPN significantly decreased GABA levels and GAD activity in the three brain regions tested compared with those in the control. Pretreatment with bilobalide effectively suppressed the MPN-induced reduction in GABA levels and GAD activity in the hippocampus and cerebral cortex. On the other hand, there were no significant differences in the glutamate levels in the three regions despite various treatments. These results suggested that bilobalide prevents MPN-induced reduction in GABA levels through potentiation by bilobalide of GAD activity, and this effect of bilobalide contributes to its anticonvulsant effect against MPN-induced convulsions.

Animals↗
PubMed2000

Synergistic effect of anti-T cell receptor monoclonal antibody and 15-deoxyspergualin on cardiac xenograft survival in a mouse-to-rat model.

BACKGROUND: Successful xenograft transplantation faces several obstacles including the presence of xenoantibodies, natural killer cell- and macrophage-mediated rejection, and T lymphocyte activation. METHODS: A mouse-to-rat cardiac xenograft model was used to examine the synergistic effect of anti-T cell receptor (TCR) monoclonal antibodies (mAb) and 15-deoxyspergualin (DSG) on graft survival. RESULTS: Pretransplantation injections (days -5, -3, and -1) of anti-TCR mAb (500 microg/kg/day) combined with continuous i.p. infusion of DSG (5 mg/kg/day) from day -7 to 28 significantly prolonged graft survival compared to untreated controls (3.3+/-0.5 vs. 44.2+/-5.6 days, P<0.001). Postoperative splenectomy combined with discontinuation of all other treatment on day 28 enhanced graft survival in rats treated with anti-TCR mAb and DSG to 71.0+/-2.5 days. Histological examination of grafts showed characteristic signs of vascular rejection: interstitial edema and hemorrhage, and polymorphonuclear cell infiltration. Antimouse antibody titers in recipients were increased upon rejection in each group that received a xenograft. Flow cytometry analysis showed a markedly decreased T cell population and a relatively increased mature B cell population (IgM(bright)/IgD(dull)) in spleens of rats treated with anti-TCR mAb and DSG on day 28. CONCLUSIONS: The mechanism of prolonged xenograft survival in this model may include inhibition of antibody production by arrest of B-cell maturation during development from IgM(dull)/IgD(bright) mature B cells to antibody producing cells, and inhibition of T cell activation. The rejection seen in our model may be caused by xenoreactive antibodies and may be associated with T cells, natural killer cells, and macrophages.

Animals↗
PubMed2000

Thoracic aortic aneurysm complicated with severe coronary arterial occlusive disease.

The patient was a 77-year-old female who had been treated medically for angina pectoris since 5 years ago. Expanded aneurysms in the distal aortic arch and in the descending thoracic aorta were seen during follow-up. She presented continuous back-pain at rest along with increasing size of the aneurysms despite antihypertensive therapies after admission. First, two saphenous vein grafts were anastomosed to the left anterior descending artery and obtuse marginal artery under beating heart. Next, the proximal portion of the left subclavian artery was clamped and divided. To this graft, the proximal ends of the coronary bypassed vein grafts were anastomosed and coronary perfusion was established and maintained until this artery was anastomosed to the aortic graft. Then, the aneurysms in the distal arch and descending thoracic aorta were excised and the aorta and its two pairs of intercostal arteries were reconstructed. The Postoperative course was uneventful with favorable cardiac function.

Aged↗
PubMed2000

Improvement of intestinal absorption of peptides: adsorption of B1-Phe monoglucosylated insulin to rat intestinal brush-border membrane vesicles.

In a previous study we glycosylated insulin to improve its intestinal absorption. When the glycosylated product, p-(succinylamido)-phenyl-alpha-D-glucopyranoside (SAPG)-substituted insulin (SAPG-INS), was administered intra-intestinally to rats, it showed a greater hypoglycemic effect than native bovine insulin. The enhanced hypoglycemic effect of SAPG-INS was considered to be due to an increase in membrane permeability as well as an increase in resistance to enzymatic degradation. In particular, membrane permeability may be related to an interaction with the Na(+)-dependent D-glucose transporter (SGLT-1) which is located in the brush-border membrane of epithelial cells. The insulin product used in the previous study, however, comprised a mixture of mono-, di- and tri-SAPG-substituted insulin. In this study SAPG-INS with a defined substitution number and position was synthesized to examine the interaction between the transporter and glycosylated insulin in more detail. The new product was mono-SAPG-substituted insulin substituted at the B1-phenylalanine position (B1-SAPG-INS) and was selectively synthesized after protection of the A1-glycine and varepsilonB29-lysine amino acids. The hypoglycemic effect of B1-SAPG-INS in rats after an intravenous dose of 71 microg/kg was almost the same as that of native bovine insulin at a dose of 1 U/kg and B1-SAPG-INS retained about 60% of the immunoreactivity of native bovine insulin. The interaction of B1-SAPG-INS with the intestinal transporter was examined by a rapid filtration technique using (125)I-labeled B1-SAPG-INS and brush-border membrane vesicles (BBMVs) which were prepared from rat small intestine by the Mg-precipitation method. The amount of B1-SAPG-INS adsorbed or absorbed by BBMVs in the presence of an inward Na(+)-gradient into BBMVs was greater than that of native bovine insulin. This adsorption/absorption was significantly inhibited by the presence of 1 mM phloridzin. A similar inhibition was observed when Na(+) was replaced with K(+) and when B1-SAPG-INS was incubated with BBMVs at 4 degrees C. From the effect of osmolarity on the extent of adsorption/absorption, it was considered that B1-SAPG-INS was not taken up into the intravesicular space but adsorbed onto the external membrane surface of BBMVs. These findings suggested that B1-SAPG-INS was adsorbed specifically onto the transporter. The hypoglycemic effect of insulin was enhanced by glycosylation at the B1 position in in situ experiments using normal and diabetic rats. Consequently, it is suggested that B1-SAPG-INS was adsorbed specifically onto the glucose transporter of intestinal BBM. This specific adsorption may be involved in the mechanism of the enhanced hypoglycemic effect of B1-SAPG-INS both in normal and diabetic rats.

Adsorption↗
PubMed2000

Postoperative delirium in patients with chronic lower limb ischaemia: what are the specific markers?

OBJECTIVES: we determined the incidence and specific markers of postoperative delirium in elderly patients with chronic lower limb ischaemia. PATIENTS AND METHODS: since April, 1995, 110 patients aged 60 years or older (mean: 71.6+/-6.6 years) who underwent bypass surgery were assessed regarding aetiological factors of delirium: age, sex, dementia, body-mass index, hypertension, diabetes, cerebral disease, laboratory test results, severity of limb ischaemia, type of arterial occlusion, operative time, and blood transfusion. RESULTS: discriminant analysis showed statistical significance in the following five variables: age >/=70 years; critical limb ischaemia (and/or ankle pressure <40 mmHg); dementia; duration of operation >/=7 hours; low serum albumin. The overall percentage of cases correctly classified was 78.2% (Wilks>> Lambda=0.695, p<0.001); the standardized regression coefficients of the five variables were 0.648, 0.500, 0.329, 0.218, and 0.200, respectively. In logistic regression, the regression coefficients for old age and critical limb ischaemia were 2.646 (14.1 of odds ratio; 95% confidence interval, 2.7-72.0) and 1.337 (3.8; 1.3-10.9), respectively. CONCLUSIONS: the incidence of postoperative delirium in elderly patients with chronic lower-limb ischaemia was as high as 42.3%, and an age of over 70 years and critical limb ischaemia were identified as specific markers, with 14.1 times and 3.8 times the odds of suffering from delirium after bypass surgery.

Age Distribution↗