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Biomedical subjects

M Hase

Publications and source records attributed to M Hase.

At least 19 recordsLinked to original sources
PubMed2007

Manipulation of cell-sized phospholipid-coated microdroplets and their use as biochemical microreactors.

Cell-sized water droplets coated by a phospholipid layer mimicking the inner surface of living cells were manipulated by laser tweezers and used as biochemical microreactors. The cell-sized phospholipid-coated microdroplets (CPMDs) consisted of a water droplet in mineral oil with a diameter of 1-100 microm and coated by 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine. We monitored the time development of biochemical reactions in a single CPMD obtained after the controlled fusion of two CPMDs containing a substrate and an enzyme, respectively. We present results on two enzymatic reactions: calcein production in the presence of esterase and green fluorescence protein expression.

Biochemistry↗
PubMed2006

Lower haemoglobin level and subsequent decline in kidney function in type 2 diabetic adults without clinical albuminuria.

AIMS/HYPOTHESIS: Anaemia has been suggested to be an independent risk factor for subsequent progression of advanced diabetic nephropathy; however, the relationship between haemoglobin levels and progression of nephropathy in patients without clinical albuminuria is unknown. METHODS: We conducted this prospective hospital-based cohort study of 464 type 2 diabetic patients (149 women and 315 men, 55+/-13 [mean+/-SD] years of age) with serum creatinine <177 micromol/l (2.00 mg/dl) and urinary albumin : creatinine ratio <300 mg/g creatinine. GFR was estimated using the equation formulated by the Modification of Diet in Renal Disease Study group, refitted for Japanese individuals. Most patients had haemoglobin concentrations in the normal range (144+/-15 g/l), only modest renal impairment (GFR: 74.8+/-14.5 ml min(-1) 1.73 m(-2)), and normal urinary albumin levels (81.5/18.5% with normo-/microalbuminuria). The primary outcome measurement was the rate of change in GFR determined by regression analysis with GFR as a function of time. Patients were followed up for a mean observation period of 5.0+/-0.9 (range: 2.5 to 6.2) years. RESULTS: Univariate and multiple regression analyses yielded a significant association between the rate of change in GFR and baseline haemoglobin concentration. After adjusting for covariates, the rate of decline in GFR was significantly greater in patients in the lowest haemoglobin quartile (-3.27 ml min(-1) 1.73 m(-2) year(-1)) than in the third (-2.71 ml min(-1) 1.73 m(-2) year(-1), p = 0.024) and highest quartiles (-2.78 ml min(-1) 1.73 m(-2) year(-1), p = 0.046). CONCLUSIONS/INTERPRETATION: Lower haemoglobin concentrations in type 2 diabetic patients without clinical albuminuria may be a significant predictor of subsequent decline in GFR.

Adult↗
PubMed2006

Structural transition of actin filament in a cell-sized water droplet with a phospholipid membrane.

Actin filament, F-actin, is a semiflexible polymer with a negative charge, and is one of the main constituents of cell membranes. To clarify the effect of cross talk between a phospholipid membrane and actin filaments in cells, we conducted microscopic observations on the structural changes in actin filaments in a cell-sized (several tens of micrometers in diameter) water droplet coated with a phospholipid membrane such as phosphatidylserine (PS; negatively charged head group) or phosphatidylethanolamine (PE; neutral head group) as a simple model of a living cell membrane. With PS, actin filaments are distributed uniformly in the water phase without adsorption onto the membrane surface between 2 and 6 mM Mg2+, while between 6 and 12 mM Mg2+, actin filaments are adsorbed onto the inner membrane surface. With PE, the actin filaments are uniformly adsorbed onto the inner membrane surface between 2 and 12 mM Mg2+. With both PS and PE membranes, at Mg2+ concentrations higher than 12 mM, thick bundles are formed in the bulk water droplet accompanied by the dissolution of actin filaments from the membrane surface. The attraction between actin filaments and membrane is attributable to an increase in the translational entropy of counterions accompanied by the adsorption of actin filaments onto the membrane surface. These results suggest that a microscopic water droplet coated with phospholipid can serve as an easy-to-handle model of cell membranes.

Journal Article↗
PubMed2003

Severe paradoxical intracranial embolism and pulmonary emboli during hip hemiarthroplasty.

Both paradoxical intracranial embolism, an intracranial arterial embolism caused by venous embolic material that has passed through a right-to-left shunt, and pulmonary arterial embolism are life-threatening complications of joint arthroplasty. We report a case of severe paradoxical intracranial embolism and pulmonary embolism that occurred during hip hemiarthroplasty.

Aged↗
PubMed2002

Adhesions in the temporomandibular joint: formation and significance.

BACKGROUND: Adhesions are frequently seen in the deranged temporomandibular joint (TMJ). In the early stage of the degenerative process the adhesion does not seem to be a significant factor in reduced mandibular movement. This is reversed in advanced degenerative joint disease where the adhesion requires release to achieve a satisfactory clinical result. Correlation of clinical history and findings within the joint should increase understanding of limited jaw movement. METHODS: Arthroscopic examination of deranged TMJs was performed on 75 patients with limited jaw opening and correlated with the history of the derangement. RESULTS: A progressive maturation of adhesion formation was observed with longer standing symptoms. A different adhesion pattern was noted with derangement caused by direct trauma on the joint. CONCLUSIONS: Internal derangement of the TMJ is associated with formation of intra-articular adhesions. These are unlikely to be associated with reduced condyle movement in the early phase of the derangement. Later stage adhesions are more substantial and require release to achieve a satisfactory clinical outcome.

Adolescent↗
PubMed2001

Transient left ventricular apical ballooning without coronary artery stenosis: a novel heart syndrome mimicking acute myocardial infarction. Angina Pectoris-Myocardial Infarction Investigations in Japan.

OBJECTIVES: To determine the clinical features of a novel heart syndrome with transient left ventricular (LV) apical ballooning, but without coronary artery stenosis, that mimics acute myocardial infarction, we performed a multicenter retrospective enrollment study. BACKGROUND: Only several case presentations have been reported with regard to this syndrome. METHODS: We analyzed 88 patients (12 men and 76 women), aged 67 +/- 13 years, who fulfilled the following criteria: 1) transient LV apical ballooning, 2) no significant angiographic stenosis, and 3) no known cardiomyopathies. RESULTS: Thirt-eight (43%) patients had preceding aggravation of underlying disorders (cerebrovascular accident [n = 3], epilepsy [n = 3], exacerbated bronchial asthma [n = 3], acute abdomen [n = 7]) and noncardiac surgery or medical procedure (n = 11) at the onset. Twenty-four (27%) patients had emotional and physical problems (sudden accident [n = 2], death/funeral of a family member [n = 7], inexperience with exercise [n = 6], quarreling or excessive alcohol consumption [n = 5] and vigorous excitation [n = 4]). Chest symptoms (67%), electrocardiographic changes (ST elevation [90%], Q-wave formation [27%] and T-wave inversion [97%]) and elevated creatine kinase (56%) were found. After treatment of pulmonary edema (22%), cardiogenic shock (15%) and ventricular tachycardia/fibrillation (9%), 85 patients had class I New York Heart Association function on discharge. The LV ejection fraction improved from 41 +/- 11% to 64 +/- 10%. Transient intraventricular pressure gradient and provocative vasospasm were documented in 13/72 (18%) and 10/48 (21%) of the patients, respectively. During follow-up for 13 +/- 14 months, two patients showed recurrence, and one died suddenly. CONCLUSIONS: A novel cardiomyopathy with transient apical ballooning was reported. Emotional or physical stress might play a key role in this cardiomyopathy, but the precise etiologic basis still remains unclear.

Adolescent↗
PubMed2000

Mutant DnaA proteins defective in duplex opening of oriC, the origin of chromosomal DNA replication in Escherichia coli.

We characterized three mutant DnaA proteins with an amino acid substitution of R334H, R342H and E361G that renders chromosomal replication cold (20 degrees C) sensitive. Each mutant DnaA protein was highly purified from overproducers, and replication activities were assayed in in vitro oriC replication systems. At 30 degrees C, all three mutant proteins exhibited specific activity similar to that seen with the wild-type protein, whereas at 20 degrees C, there was much less activity in a replication system using a crude replicative extract. Regarding the affinity for ATP, the dissociation rate of bound ATP and binding to oriC DNA, the three mutant DnaA proteins showed a capacity indistinguishable from that of the wild-type DnaA protein. Activity for oriC DNA unwinding of the two mutant DnaA proteins, R334H and R342H, was more sensitive to low temperature than that of the wild-type DnaA protein. We propose that R334H and R342H have a defect in their potential to unwind oriC DNA at low temperatures, the result being the cold-sensitive phenotype in oriC DNA replication. The two amino acid residues of DnaA protein, located in a motif homologous to that of NtrC protein, may play a role in the formation of the open complex. The E361 residue may be related to interaction with another protein present in a crude cell extract.

Adenosine Triphosphate↗
PubMed2000

Does primary stenting preserve cardiac function in myocardial infarction? A case-control study. NORTH-981 investigators. Network of revascularisation therapy in Hokkaido.

OBJECTIVE: To investigate whether coronary stenting limits myocardial injury and preserves left ventricular function. DESIGN AND SETTING: Prospective multicentre case-control study of primary percutaneous transluminal coronary angioplasty (PTCA) with and without stenting, performed in seven cardiovascular centres. SUBJECTS AND METHODS: 45 consecutive patients with acute myocardial infarction who were treated with successful primary stenting (Stent group) and did not have restenosis were paired with 45 matched control subjects with acute myocardial infarction treated by successful primary PTCA without stenting, also with no restenosis (POBA group). RESULTS: In comparison with the POBA group, the Stent group-especially those patients with a left anterior descending coronary artery lesion-had a smaller hypokinesis area (mean (SD): 15. 1 (20.0) v 34.4 (24.3) chords), reduced hypokinesis area/risk area (25.2 (31.9)% v 58.8 (40.1)%), and a larger ejection fraction (63.3 (10.2)% v 51.7 (11.7)%) evaluated by quantitative left ventriculography using the centerline method. In the Stent group, the correlation between risk area and hypokinesis area was significantly shifted downward. Multiple logistic regression analysis on infarct size limitation (hypokinesis area/risk area < 50%) identified preinfarction angina in all subjects and preinfarction angina and stenting in patients with left anterior descending coronary artery lesions as explanatory factors. CONCLUSIONS: Primary PTCA using a coronary stent is effective in preventing myocardial injury and restoring left ventricular function in patients with anterior acute myocardial infarction.

Adult↗
PubMed2000

Plasma LH and progesterone levels before and after ovulation and observation of ovarian follicles by ultrasonographic diagnosis system in dogs.

Recently, canine frozen semen has been attracting attention for breeding purposes, and methods of judging ovulation and optimum timing for insemination have become important. As methods of predicting the canine ovulation, vaginal smear, plasma sex hormone levels and ultrasonographic diagnosis system (US) have been investigated in combination, but a standard technique has not yet been established. Therefore, we investigated a method of predicting canine ovulation in dogs by US, and by measuring plasma LH and progesterone (P) levels three times a day. Ovulation could be observed by detecting irregularly shaped ovarian follicles by US in six of 11 dogs (54.5%). In these dogs, the time between the LH peak and ovulation was 24-48 hr, 38.0 hr on average. The P level on the ovulation day was 1.88-2.81 ng/ml, 2.34 ng/ml on average. A value of 1.88 ng/ml was detected in one dog, but the other five dogs showed P levels of 2 ng/ml or higher. The P level on the day before ovulation was 0.8-1.56 ng/ml, 1.12 ng/ml on average. Assuming that ovulation occurred two days after the LH peak in the 11 experimental dogs, the P level was 2.12-4.06 ng/ml, 2.78 ng/ml on average. The period of a high LH level, not less than 10 ng/ml, continued for 12 hr around the LH peak. Based on these findings, to predict ovulation using US and LH level, it would be necessary for the tests to be performed several times a day. In contrast, it was shown that the day on which a plasma P level of 2 ng/ml or higher was detected by the test performed once a day corresponded to the ovulation day.

Animals↗
PubMed2000

Effects of orvus ES paste on canine spermatozoal longevity after freezing and thawing.

Because of weak resistance of canine sperm to freezing, an applicable method of preparing canine frozen semen has not yet been established. We added various concentrations of Orvus ES Paste (OEP) to egg yolk Tris-fructose citrate, and investigated its effectiveness on survival of spermatozoa. Addition of 0.5-1.0% OEP to the extender for freezing canine semen was effective in prolonging post-thaw survival of spermatozoa.

Animals↗
PubMed2000

Effect of addition of Orvus ES paste to frozen canine semen extender on sperm acrosomes.

Using the triple-stain technique, we investigated whether sperm acrosomes in frozen canine semen were protected during freezing and thawing by addition of a surfactant, Orvus ES Paste (OEP), to the extender. Acrosomes were clearly shown to be protected by the addition of OEP to the entender when compared with those in sperm frozen without OEP addition (p<0.05).

Acrosome↗
PubMed2000

Intrauterine and intravaginal insemination with frozen canine semen using an extender consisting of orvus ES paste-supplemented egg yolk tris-fructose citrate.

Our previous report indicated that addition of Orvus ES Paste (OEP) to the extender of frozen canine semen protected acrosomes and maintained sperm motility after thawing. In this study, artificial insemination (AI) using the frozen semen was carried out. The frozen semen was prepared using egg yolk Tris-fructose citrate, and the final concentrations of glycerol and OEP were 7% (v/v) and 0.75% (v/v), respectively. AI was performed during the optimal mating period predicted from the peripheral plasma progesterone level. In intrauterine insemination (IUI), the bitches were laparotomized and 1 x 10(8) spermatozoa were infused into one of the uterine horns. In insemination of non-OEP supplemented semen, 3 x 10(8) spermatozoa were inseminated. In intravaginal insemination (IVI), 10-40 x 10(8) spermatozoa were inseminated. Conception was obtained in nine of 10 bitches (90.0%) that underwent IUI. The number of newborns was from 1 to 7 (mean 3.6 +/- 0.9). The mean ratio of the number of puppies to the number of ovulations in the inseminated uterine horn was 71.8%. The number of puppies did not exceed the number of ovulation in the inseminated uterine horn. Conception using non-OEP supplemented frozen semen was unsuccessful in all four bitches. In IVI, conception was not obtained in any of the six bitches that received insemination of 10 x 10(8) or 40 x 10(8) spermatozoa, but two of three bitches that received insemination of 20 x 10(8) spermatozoa were fertilized. It was shown that a high conception rate can be obtained by IUI using OEP-supplemented frozen canine semen. Developmenmt of a non-surgical method of IUI and a method of freezing canine sperm applicable to IVI is necessary.

Animals↗
PubMed1999

Involvement of Arg-328, Arg-334 and Arg-342 of DnaA protein in the functional interaction with acidic phospholipids.

We reported previously that three basic amino acids (Arg-360, Arg-364 and Lys-372) of DnaA protein are essential for its functional interaction with cardiolipin. In this study, we examined the effect of mutation of some basic amino acids in a potential amphipathic helix (from Lys-327 to Ile-345) of DnaA protein on this interaction. ATP binding to the mutant DnaA protein, in which Arg-328, Arg-334 and Arg-342 were changed to acidic amino acids, was less inhibited by cardiolipin than that of the wild-type protein, as was the case for mutant DnaA protein with mutations of Arg-360, Arg-364 and Lys-372. A mutant DnaA protein with mutations of all six basic amino acids showed the most resistance to the inhibition of ATP binding by cardiolipin. These results suggest that Arg-328, Arg-334 and Arg-342, like Arg-360, Arg-364 and Lys-372, are also involved in the functional interaction between DnaA protein and acidic phospholipids.

Adenosine Diphosphate↗
PubMed1999

Antiseptic susceptibility and distribution of antiseptic-resistance genes in methicillin-resistant Staphylococcus aureus.

We examined the antiseptic susceptibilities and distribution of antiseptic-resistance genes qacA and smr in 98 isolates of methicillin-resistant Staphylococcus aureus obtained in 1992. Seventy-one strains were resistant to antiseptics. The qacA and smr genes were detected in 10 and 20 strains, respectively. The remaining 41 strains without qacA and smr were divided into two groups that exhibited low-level (n = 22) and high-level (n = 19) resistance to acriflavin. DNA cloning and sequencing suggested that norfloxacin-resistance gene norA was responsible for the high-level resistance to acriflavin. Our results indicated that four or more antiseptic-resistance genes exist in methicillin-resistant S. aureus and that antiseptic-resistant methicillin-resistant S. aureus strains without qacA and smr are widely spread in Japan.

Acriflavine↗
PubMed1999

Anomalous systemic arterial supply to normal basal segments of the left lower lobe.

BACKGROUND: Anomalous arterial supply to the normal basal segments of the lower lobe without sequestration is a rare congenital abnormality, and whether it belongs to the broad spectrum of sequestration disorders remains controversial. METHODS: The cases of all 4 patients who were treated surgically by us were reviewed together with 8 previously reported cases. RESULTS: The anomalous artery originated from the descending thoracic aorta, distributed to the basal segments of the left lower lobe, and drained to a normal inferior pulmonary vein in each case. The anomalous artery was thick and elastic walled. From the review of all 12 cases, male gender, left side, descending thoracic aorta as the aberrant arterial origin, absence of pulmonary blood flow to the basal segments, and normal pulmonary venous drainage were predominant. Despite some differences, the findings seemed closely related to intralobar sequestration. Surgical treatments were lung resection, anastomosis, and ligation of the anomalous artery. CONCLUSIONS: This anomaly is probably one type of sequestration complex. Both aortic and pulmonary arterial angiographic studies are needed to plan the definitive surgical procedure.

Adult↗
PubMed1999

Role of hyperinsulinemia in atherosclerotic coronary arterial disease: studies of semi-quantitative coronary angiography.

OBJECTIVE: To evaluate the role of insulin resistance on coronary atherosclerosis, angiographic semiquantitative scores of coronary stenosis and calcification were evaluated. SUBJECTS AND METHODS: Ninety-five non-diabetic subjects with coronary arterial disease were selected from our angiographic data base. Hyperinsulinemia was defined as a serum insulin level of > or = 60.4 IU/l at 120 minutes after 75 g oral glucose challenge. RESULTS: Twenty-three (24%) of the patients exhibited hyperinsulinemia. There was no difference in age or gender between the two subgroups. The incidence of hypertension, smoking habits, hypercholesterolemia, and hyperuricemia were also the same among the insulin resistance subgroups. Subjects with hyperinsulinemia had higher coronary artery scores of stenosis (11.9+/-5.6 vs 8.3+/-5.0, p<0.0001) and calcification (7.5+/-6.3 vs 4.8+/-4.9, p<0.0001). Moreover, the stenosis score had a close linear correlation with the 120 minutes serum insulin level (r=0.266, p=0.009), but not with the fasting level. CONCLUSION: These results suggest that hyperinsulinemia is a risk for coronary arterial disease, and emphasize the severity of coronary atherosclerosis in normal glucose tolerant subjects.

Adult↗