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Biomedical subjects

M Haga

Publications and source records attributed to M Haga.

At least 55 records · Page 3Linked to original sources
PubMed1997

Bilobalide, a constituent of Ginkgo biloba L., potentiates drug-metabolizing enzyme activities in mice: possible mechanism for anticonvulsant activity against 4-O-methylpyridoxine-induced convulsions.

Anticonvulsant effects of bilobalide, one of the constituents of Ginkgo biloba L., on the convulsions induced by 4-O-methylpyridoxine (MPN) were investigated in mice. Bilobalide reduced the duration and incidence of MPN-induced convulsions depending on its dose and the period of treatment. In addition, the anticonvulsant effect was manifested more than 24 hours after treatment and the effect lasted for 7 days after its withdrawal. In mice treated with bilobalide (30 mg/kg, p.o., once a day for 4 days), hepatic 7-methoxycoumarin O-demethylase activity was potentiated, and the disappearance of MPN in blood after MPN injection was faster than in controls. From these results, it is assumed that the anticonvulsant effect of bilobalide against convulsions induced by MPN partly involves modulation of hepatic drug-metabolizing enzyme activity, which leads to accelerated elimination of MPN.

Administration, Oral↗
PubMed1997

Direct and indirect medical costs incurred by Canadian patients with rheumatoid arthritis: a 12 year study.

OBJECTIVE: To perform the first prospective longitudinal study of direct (health services utilized) and indirect costs (diminished productivity represented by income loss) incurred by patients with rheumatoid arthritis (RA) in Saskatoon and Montreal, followed for up to 12 and 4 years, respectively. METHODS: 1063 patients reported on health status, health services utilization, and diminished productivity every 6 months. RESULTS: Annual direct costs were $3788 (1994 Canadian dollars) in the late 1980s and $4656 in the early 1990s. Given that the average age exceeded 60 years, few participated in labor force activities or considered themselves disabled from the labor force and their indirect costs were substantially less, $2165 in the late 1980s and $1597 in the early 1990s. Institutional stays and medications made up at least 80% of total direct costs. Lengths of stay in acute care facilities remained constant, but the rate of hospitalization increased in the early 1990s, increasing average hospital costs per patient from $1563 in the late 1980s to $2023 in the early 1990s. For nonacute care facilities, rate of admission as well as length of stay increased over time, increasing costs per patient in Saskatoon 5-fold, from $291 to $1605. Those with greater functional disability incurred substantially higher direct and those under 65 years incurred higher indirect costs. CONCLUSION: Direct costs are higher than indirect costs. The major component is due to institutional stays that, in contrast to other direct cost components, is increased in the older and more disabled. Measures to reduce longterm disability by earlier, more aggressive intervention have the potential to produce considerable cost savings. However, it is unknown which strategies will have the greatest effect on outcome and accordingly, how resources can be optimally allocated.

Aged↗
PubMed1997

[Development of a blood cardioplegia delivery system for children].

We have developed a blood cardioplegia delivery system for children. Essential points of a delivery system in pediatric cardiac surgery are (1) a small amount of priming volume of a delivery system, and (2) slow, steady infusion of a cardioplegic solution. We changed a heat exchanger to a smaller one for reduction of priming volume, and changed a roller pump tube to a smaller one for slow, steady infusion. Thus, priming volume of a delivery system has reduced from 180 to 100 ml, and we can infuse a cardioplegic solution at a steady rate less than 10 ml/min. Our clinical experience with this system suggests that this blood cardioplegia delivery system is useful for pediatric cardiac surgery.

Blood↗
PubMed1996

[The study on the mechanism of brain damage due to high flow and pressure during selective cerebral perfusion].

It has been reported that the high flow and pressure perfusion produced the brain damage during selective cerebral perfusion. This time we studied the mechanism of this brain damage with mock circulation. We made the mock circulation system of brain with the hard shell reservoir as cranium, and with the triple soft bags as brain tissue, involving into reservoir. We designed the control group that intracranial pressure (ICP) was 0 mmHg at pump off, and the increasing intracranial pressure (IICP) group that ICP was 10 mmHg at pump off. We measured the flow-pressure relationship in the control and IICP group, and then stenosis in outflow. In results, the flow and pressure in both the inflow and outflow side increased significantly (p < 0.001) in control groups, as pump flow increased. The changes of the flow and pressure in IICP group showed a same tendency to the control group. Moreover, both the inflow volume into bag and the outflow volume from bag decreased as pump flow increased stepwisely. The pressure in both inflow and outflow side increased significantly and the volume of the inflow side in IICP group showed a tendency to decrease, compared with the control. The stenosis in the outflow side produced the significant increase in the pressure of both inflow and outflow side, and intracranium, with the same pump flow as the control without stenosis. In conclusion, the high flow perfusion produced the increase of the several pressure in intracranial and extracranial vessels. Moreover, the high flow perfusion produced the decrease of the intracranial blood volume cerebral blood flow. The high flow perfusion does not necessarily contribute to the cerebral tissue perfusion. The stenosis at the side of venous return produced relative high perfusion. This result suggests that the venous return should be taken care of during the selective cerebral perfusion.

Blood Pressure↗
PubMed1996

[A case report of a bronchogenic cyst of the diaphragm causing rupturing into the left pleural cavity].

A rare case of a bronchogenic cyst of the diaphragm was reported. The patient was a 56-year-old woman complaining of epigastric pain. A CT scan and a MRI examination revealed a cystic tumor at the left vertebro-phrenic angle. The cyst ruptured into the left pleural cavity causing chest pain and consequently reducing its size. As the cyst had enlarged again after 6 months, she received surgical treatment and the tumor was totally removed. The cyst was monolocular, originating from the diaphragm and proved to be bronchogenic cyst. It had bronchial epithelium, smooth muscle, bronchial gland and cartilage histologically. Japanese literature on the bronchogenic cysts of the diaphragm were discussed. Seven cases, including this case, of bronchogenic cysts of the diaphragm have been reported in Japan. It is rare for bronchogenic cysts to rupture into the pleural cavity.

Bronchogenic Cyst↗
PubMed1995

Aminolysis of acyl-chymotrypsins by amino acids. Kinetic appearance of concentration effect in peptide yield enhancement by freezing.

The effects of reagent concentrations, various added substances, pH and temperature on the yield of peptide synthesis by chymotrypsin in frozen and liquid solutions at subzero temperatures have been studied. Increased nucleophile concentration in the liquid microinclusions of ice has been shown to be sufficient for explaining the peptide yield improvement found at freezing conditions.

Amino Acids↗
PubMed1995

Long-term survival of cardiac allografts in rats treated before and after surgery with monoclonal antibody to CD2.

The rejection of a transplanted allograft is dependent on T cell activation, which requires T cell receptor engagement by antigen and costimulatory signals delivered by T cell surface molecules such as CD2. Anti-CD2 mAbs have been shown to suppress cell-mediated immunity. The effects of anti-CD2 mAbs OX34 and OX54 on rejection of BN (RT1n) rat hearts transplanted heterotopically to LEW (RT1l) rats were investigated. Administration of OX34 (7 mg/kg/day i.p.), either for 3 consecutive days immediately before or 8 consecutive days immediately after transplantation induced indefinite allograft survival (median survival time: 7, > 150, and > 150 days for control, preoperative treatment, and postoperative treatment, respectively). In contrast, pre- or postoperative treatment with OX54 (40 mg/kg/day) prolonged median survival time to only 28 and 11 days, respectively. Administration of OX34 or OX54 to naive rats induced a transient depletion of T cells in the peripheral immune organs. In vitro studies revealed that whereas OX54 had no effect on the allogeneic mixed lymphocyte reaction, OX34 partially inhibited both the allogeneic mixed lymphocyte reaction, in an IL-2-reversible manner, and T cell proliferation in response to immobilized mAb to either the T cell receptor or CD3. OX34-treated rats in which the cardiac allograft had survived > 100 days accepted a second heart from the donor strain. Treatment with OX34 induced an alloantigen-unresponsive state in T cells. These results suggest that treatment with an appropriate anti-CD2 mAb, especially postoperatively, may prove an effective approach for preventing cardiac allograft rejection.

Animals↗
PubMed1995

Self-reactive T cell clones in a restricted population of interleukin-2 receptor beta+ cells expressing intermediate levels of the T cell receptor in the liver and other immune organs.

T cells expressing high levels of the T cell receptor (TCRhigh) differentiate in the major intrathymic pathway and then distribute to the peripheral immune organs, whereas T cells expressing intermediate levels of the TCR (TCRint) differentiate in both extrathymic pathways and an alternative intrathymic pathway and localize in unique sites, including the liver and thymic medulla. Since TCRint cells constitutively express interleukin-2 receptor beta-chain (IL-2R beta), two-color staining for CD3 (or TCR) and IL-2R beta clearly distinguished IL-2R beta+ CD3int (or TCRint) cells from IL-2R beta-, CD3high cells. CD3int cells may be considered to be primordial T cells based on their phenotype, morphology and other functional properties. In this study, using anti-V beta mAb in conjunction with the endogenous superantigen Mls, the distribution of self-reactive clones among T cells generated in all of the above pathways was investigated in mice. Self-reactive T cell clones were confined to IL-2R beta+, CD3int cells, in all of the organs tested. A significant proportion of self-reactive clones was never identified among CD3high cells in the thymus and peripheral immune organs in either young (8 week old) or old (50 week old) mice. Possibly reflecting their self-reactivity, CD3int cells, but neither NK cells nor CD3high cells had a potent cytotoxic effect against a syngeneic hepatoma in the presence of anti-CD3 mAb. These results raise the possibility that CD3int cells seen in the liver and thymus might belong to a similar primordial lineage of T cells, and that self-reactive clones are not generated through the major intrathymic pathway, but only through extrathymic pathways and an alternative intrathymic pathway.

Age Factors↗
PubMed1995

Columbin isolated from calumbae radix affects the sleeping time of anesthetized mice.

In a screening series of bioactive components in edible and medicinal plants, we found that Calumbae Radix (Colombo root, 1% powdered feed, for 5 d) and its component, columbin (20-40 mg/kg/d, for 5 d, orally), shortened the sleeping time induced by a urethane and alpha-chloralose mixture and prolonged the sleeping time induced by hexobarbital in mice.

Anesthesia↗
PubMed1995

Infrared/video ENG recording of positional nystagmus in subjects with peripheral vestibular disease.

We performed simultaneous infrared/video and electronystagmorgraphy (ENG) recordings of eye movements in 417 patients with disequilibrium. Of that number, 54 patients with the following two criteria participated in this study: verified diagnosis of peripheral vestibular disease and the presence of positional nystagmus recorded by ENG and an infrared/ video recording system. Although horizontal nystagmus was the most common, torsional, vertical and oblique nystagmus were also demonstrated in these patients. The most striking finding was the high incidence of oblique nystagmus closely related to a significant right-left difference of the caloric response in benign positional vertigo.

Adolescent↗
PubMed1995

[Detection of glomerular and non-glomerular red blood cells by automated urinary sediment analyzer].

There is increasing interest in the examination of urine sediment to differentiate between glomerular and non-glomerular hematuria. A newly developed automated urinary sediment analyzer was used for this purpose. It clearly recognized red blood cells, white blood cells, epithelial cells, bacteria and crystals by their cell size and fluorescent intensity. Ninety-eight urine samples from 31 glomerular and 67 non-glomerular lesions were analyzed by the analyzer and 69 samples, by light microscopy. According to the analysis of their histograms, a forward scatter (FSC) intensity of less than 126, where 80% of the smaller red blood cells were observed, was diagnosed as glomerular hematuria. A FSC intensity of more than 84, where 80% of the large red blood cells were counted, was non-glomerular hematuria. An FSC intensity between 84 and 126 was considered to be the overlap zone of glomerular and non-glomerular hematuria. The sensitivity for glomerular red blood cells was found to be 100% and specificity, 92.54% by means of flow cytometric analysis. On the other hand, light microscopic analysis yielded 95.83% sensitivity and 93.33% specificity for glomerular lesions. Flow cytometric analysis of the urinary red blood cells was concluded to be a fast, simple and reliable method to differentiate glomerular and non-glomerular hematuria.

Adolescent↗
PubMed1994

The mortality of rheumatoid arthritis.

OBJECTIVE: To determine the risk and causes of death and to quantify mortality predictors in patients with rheumatoid arthritis (RA). METHODS: RA patients (n = 3,501) from 4 centers (Saskatoon n = 905, Wichita n = 1,405, Stanford n = 886, and Santa Clara n = 305) were followed for up to 35 years; 922 patients died. RESULTS: The overall standardized mortality ratio (SMR) was 2.26 (Saskatoon 2.24, Wichita 1.98, Stanford 3.08, Santa Clara 2.18) and increased with time. Mortality was strikingly increased for specific causes: infection, lymphoproliferative malignancy, gastroenterologic, and RA. In addition, as an effect of the SMR of 2.26, the expected number of deaths was increased nonspecifically across all causes (except cancer), with a large excess of deaths attributable to cardiovascular and cerebrovascular diseases. Independent predictors of mortality included age, education, male sex, function, rheumatoid factor, nodules, erythrocyte sedimentation rate, joint count, and prednisone use. CONCLUSION: Mortality rates are increased at least 2-fold in RA, and are linked to clinical severity.

Arthritis, Rheumatoid↗
PubMed1994

Outcome in patients with rheumatoid arthritis receiving prednisone compared to matched controls.

OBJECTIVE: To determine the longterm outcome including disease activity, mortality, and adverse events in patients with rheumatoid arthritis (RA) treated with prednisone. METHODS: A case-control study was performed, based on our cohort of 893 mostly Caucasian patients with adult onset RA, followed since 1966. Data collection was based on protocols and included single physician global assessment. Prednisone was started in 122 patients (85 women, 37 men) after 1966. All were matched for age, sex, disease duration, and global assessment to 122 controls from the same cohort who have never received prednisone. RESULTS: Mean disease duration before prednisone was 14.1 years. Mean duration of use was 6.9 years with a mean dose of 8.0 mg/day. Prednisone was eventually stopped in 34% of patients. Life expectancy and causes of death were similar in both groups. No differences in hemoglobin, erythrocyte sedimentation rate, global assessment, Lansbury index, functional class or Health Assessment Questionnaire (HAQ) disability index were seen between the 2 groups before or 5 years after starting prednisone. Ten years after starting prednisone, HAQ scores were similar but Lansbury and global assessment were worse in the prednisone treated group. As expected, adverse events, notably cataracts and fractures, were observed more often in the prednisone group. CONCLUSION: Case-control matching can only reduce, not eliminate, potential selection bias. Nonetheless, the lack of demonstrable longterm benefit with prednisone use in this and other studies is disconcerting. Caution and further studies are required before the more aggressive use of longterm prednisone therapy in RA is embraced.

Adolescent↗
PubMed1993

Peptide synthesis by chymotrypsin in frozen solutions. Free amino acids as nucleophiles.

Nucleophilic efficiency of the free amino acids in chymotrypsin-catalyzed acyl transfer in ice at -18 degrees C using ethyl esters of N-maleyl-L-tyrosine and L-tyrosine as the acyl group donors has been studied. Although the amino acids did not act as acyl acceptors in liquid water, the high yields of peptides were obtained in frozen solutions at pH 10.5 (before freezing). The efficiency of amino acids in the formation of the corresponding dipeptides depended on the substrate used, and decreased in the order Ser,Thr,Gln > Lys > Cit > Ala > Ala > Gly > Asn > Arg > Glu > Val > Orn > Asp with no peptide formed with His, Leu, Ile and Pro) for N-maleyl-L-tyrosine ethyl ester and Ser > Lys > Orn > Arg,Cit > Gln > Thr > Asn > Ala > Gly (with no peptide formed with Glu, Val, Asp, His, Leu, Ile and Pro) for L-tyrosine ethyl ester.

Amino Acids↗
PubMed1993

Metabolic interaction of ethanol and cyclohexanone in rabbits.

The interaction of ethanol (EtOH) and cyclohexanone (CHN) metabolism was studied to demonstrate the influence of alcohol beverage in cyclohexanone poisoning. Rabbits were administered CHN and EtOH separately or together, and the plasma concentration of CHN and cyclohexanol (CHL), a metabolite of CHN, and blood concentrations of EtOH were measured at various times. When CHN alone was administered orally, the time to maximum plasma concentration (Tmax) of CHN was as short as 15 min, but that of CHL was 120 min. The short Tmax of CHN was considered to be due to the first-pass effect. The plasma concentration of CHL was much greater than that of CHN. On the other hand, when the same amount of molar CHL was administered in rabbits for sake of comparison, only small amounts of CHN were detected in plasma. The interconversion between CHN and CHL at the time of equilibration tended to shift predominantly toward the formation of CHL, whose plasma concentration ratio was about 1:6 to 1:8. The coadministration of EtOH decreased the plasma concentration of CHN and increased that of CHL more than the administration of CHN alone. The blood concentration of EtOH was also decreased with the coadministration of CHN. The coadministration of EtOH with CHN demonstrated an acceleration in the metabolism of both CHN and EtOH, which may be due to an increase in the concentrations of the alcohol dehydrogenase-NADH and -NAD complexes.

Administration, Oral↗