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Biomedical subjects

H Sekino

Publications and source records attributed to H Sekino.

At least 19 recordsLinked to original sources
PubMed1992

Comparative study of magnetic resonance and CT scan imaging in cases of severe head injury.

The distribution, frequency, and appearance of head injuries were evaluated with MRI and CT in a prospective study of 155 patients with acute (n = 124) and chronic (n = 31) head injuries. MRI was significantly more sensitive than CT in the detection of intraaxial injury at any stage. In severe cases, central structure lesions were detected in approximately 80% of patients. Severity on admission was compatible with MR findings. However it was difficult to decide on neurobehavioural prognosis from initial MRI findings only.

Adolescent↗
PubMed1992

The accuracy and performance of the A&D TM 2421, a new ambulatory blood pressure monitoring device based on the cuff-oscillometric method and the Korotkoff sound technique.

The accuracy and performance of the A&D TM 2421, a new ambulatory blood pressure (BP) monitoring device using both the cuff-oscillometric method (O) and the Korotkoff sound method (K) were evaluated. The device was tested for accuracy under static and dynamic conditions by simultaneous comparison with two observers using a standard mercury column sphygmomanometer (standard method) and by the objective recording method (ORM). The performance of the device was also evaluated under ordinary ambulatory conditions. The mean differences in BP of standard method from K-method were -1.2 +/- 4.7 mm Hg systole and 1.3 +/- 4.7 mm Hg diastole (n = 323, mean +/- SD) and those of standard method from O-method were -0.4 +/- 5.3 mm Hg systole and 1.4 +/- 5.1 mm Hg diastole (n = 323). The agreement between each of the two methods of the device and the standard method was within 10 mm Hg for more than 90% of both systolic and diastolic readings. During bicycle exercise, the mean differences in BP of standard method from K-method were -3.4 +/- 4.8 mm Hg systole and 1.8 +/- 5.2 mm Hg diastole (n = 71) and those of standard method from O-method were -1.1 +/- 7.3 mm Hg systole and 1.7 +/- 7.8 mm Hg diastole (n = 67). There was a greater scatter in the individual comparisons of the device and the standard method during exercise, especially in diastolic BP. The relation between the device and ORM was almost similar to that between the device and the standard method.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Acquired cystic disease of the kidney and renal carcinoma in haemodialysis patients: ultrasonographic evaluation.

Ultrasonography was performed in 661 dialysis patients and acquired cystic disease of the kidney was found in 156 (125 men and 31 women). A higher incidence of cystic disease was found in males. There was no significant difference between the patients with and those without acquired cystic disease in terms of average age, but the duration of haemodialysis in those with acquired cystic disease was significantly longer. There was an increased incidence of cystic disease in patients with glomerulonephritis and the duration of haemodialysis in these patients was significantly longer. This suggests that the increased incidence of acquired cystic disease of the kidneys in the patients with glomerulonephritis is simply related to the longer duration of treatment. Twelve patients with renal carcinoma were found in this study. The average age at diagnosis of renal carcinoma was not significantly different between the patients with and those without acquired cystic disease, but the duration of dialysis was significantly longer in renal carcinoma patients with acquired cystic disease. The incidence of renal carcinoma in dialysis patients with acquired cystic disease was 3.85% and in those without it was 1.19%. These rates are considerably higher than those found in the general population and indicate that the risk of renal carcinoma is higher in dialysis patients both with and without acquired cystic disease.

Adult↗
PubMed1992

The influence of antihypertensive agents on circadian rhythms of blood pressure and heart rate in patients with essential hypertension.

The effects of once-daily administration of calcium (Ca) channel blockers, beta-blockers and and angiotensin-converting enzyme (ACE) inhibitors on circadian rhythms of blood pressure (BP) and heart rate (HR) were studied using the cosinor method. Sixty-two recruited patients with essential hypertension (WHO stage I or II) were divided into three groups based on the class of administered drugs. In the Ca channel blocker group (n = 37, age 54 +/- 9.0 years), 18 patients were given YM 730 at a mean dose of 11 +/- 4.0 mg/day (mean +/- S.D.), 8 were given nitrendipine (11 +/- 6.7 mg/day), and 11 were given nisoldipine (8 +/- 6.4 mg/day). In the beta-blocker group (n = 15, age 42 +/- 13.5 years), 13 patients were given atenolol (44 +/- 11.0 mg/day), 1 was given nadolol (30 mg/day), and 1 was given sustained-release propranolol (60 mg/day). In the ACE inhibitor group (n = 10, age 56 +/- 8.7 years), 7 patients were given enalapril (6 +/- 2.8 mg/day), and 3 were given lisinopril (20 mg/day). Ambulatory BP monitoring (ABPM) was performed before and during treatment. Mean arterial pressure (MAP) and HR were monitored under ambulatory conditions every five minutes for 24 hr with a finger volume oscillometric device. In all three groups, the mesor of MAP decreased significantly, while the amplitude and acrophase did not change during treatment. beta-Blockers reduced the amplitude as well as the mesor of HR. Ca channel blockers increased the amplitude of HR without influencing the mesor. ACE inhibitors had no effect on the circadian rhythm parameters of HR. These results suggest that Ca channel blockers, beta-blockers and ACE inhibitors lowered BP throughout the day without changing the circadian BP rhythm. However, the three drug classes may have different influences on the autonomic nervous system that regulates circadian cardiac rhythm.

Adrenergic beta-Antagonists↗
PubMed1992

The effects of intrarenal infusion of recombinant human erythropoietin on mean arterial pressure and renal hemodynamics in anesthetized rabbits.

The effects of recombinant human erythropoietin (rHuEPO) on mean arterial pressure (MAP) and renal hemodynamics were studied in anesthetized rabbits without renal failure. Intrarenal infusion of rHuEPO at a rate of 100 U/min for 30 min resulted in no change in MAP, renal blood flow, or renal vascular resistance. rHuEPO also produced no significant change in glomerular filtration rate filtration fraction, or arterial hematocrit. These results demonstrate that rHuEPO has no direct effects on MAP or renal hemodynamics in anesthetized rabbits without renal failure.

Anesthesia↗
PubMed1992

Effect of slow release nifedipine tablets in patients with essential hypertension.

The antihypertensive effect of slow release nifedipine (CAS 21829-25-4) tablets (20 mg, Adalat) administered once or twice daily was studied in patients with essential hypertension of WHO stage I or II. Ambulatory blood pressure was monitored by a finger volume oscillometric device every 5 min for 24 h before and during the treatment with nifedipine. Whether administered once or twice daily, nifedipine tablets dit not change the pattern of circadian blood pressure variation; i.e. diurnal rise and nocturnal fall. Twice daily administration induced a significant downward shift in the blood pressure pattern. In other words, further hypotensive effect was observed during the night when the blood pressure was already low. On the other hand, administration once daily in the morning lowered daytime blood pressure without affecting blood pressure during the night. The duration of action of nifedipine tablets administered once daily was 12 h or more. In the acute experiment using 20 mg tablets of nifedipine, plasma concentration of nifedipine was well correlated with the percentage change in mean blood pressure. The minimal effective plasma concentration of nifedipine was estimated to be 13.4 ng/ml. However, in chronic treatment, nifedipine lowered blood pressure at the plasma concentration of 10 ng/ml. The results indicate that nifedipine tablets administered once daily provide an effective antihypertensive regimen for controlling daytime hypertension with minimal antihypertensive effect during the night.

Adult↗
PubMed1992

Solid-phase syntheses of two deacetyl-thymosin alpha 1 analogues with substitution at position 21 and their effects on low E-rosette-forming lymphocytes of uremic patients.

Two deacetyl-thymosin alpha 1 analogues containing Phe or Phe(4F) at position 21 were synthesized by the manual solid-phase method and their immunological effects on the low E-rosette-forming lymphocytes of uremic patients were studied. Fluorination of the p-position of Phe21 resulted in a marked restorative effect on the low E-rosette-forming lymphocytes of uremic patients compared with that of [Phe21]deacetyl-thymosin alpha 1. The synthetic [Phe21]deacetyl-thymosin alpha 1 was approximately equal in potency to our synthetic deacetyl-thymosin alpha 1 in uremic patients.

Amino Acid Sequence↗
PubMed1992

Hydroxyl radical-induced characteristic chemiluminescent spectra from plasma of hemodialysis patients.

Plasma from hemodialysis patients evoked weak photon emissions (chemiluminescence) in a characteristic emission spectrum with a peak at 430 nm, attributed to attack by hydroxyl radicals generated from the iron-catalyzed breakdown of hydrogen peroxide (Fenton reaction), whereas plasma from normal healthy subjects showed a rather weak red chemiluminescence peak at around 680 nm, similar to that resulting from attack by hydroxyl radicals. However, the addition of hydrogen peroxide in the absence of divalent irons induced almost the same red chemiluminescent emission spectrum in both plasmas. The HPLC-gel-filtration chromatography carried out with both plasmas revealed that a primary emitter evoking a peak emission at 430 nm was located in the fraction of lower-molecular-mass substances in fractionated plasma from hemodialysis patients. In contrast, the elution peaks evoking red chemiluminescence with the addition of hydrogen peroxide were mainly observed for the higher-molecular-mass fraction, as determined by gel chromatography of both plasmas. Therefore, the observation of a chemiluminescence peak at 430 nm, induced by the generation of hydroxyl radicals, correlated well with chemiluminescent emissions in plasma samples from patients with chronic renal failure. Spectral analyses of clinical samples that show weak chemiluminescence by forced oxidation by such an active oxygen may provide a new and more sensitive method for diagnosing metabolic disorders.

Chromatography, Gel↗
PubMed1992

[Application of nasal intermittent positive pressure ventilation to a case of limb-girdle muscular dystrophy].

We applied nocturnal ventilation (NV) with nasal intermittent positive pressure ventilation with custom molded mask (NIPPV-C Mclermott, 1989), as well as NV with tracheostomy intermittent positive pressure ventilation (TIPPV) to a male patient with limb-girdle muscular dystrophy who had developed chronic respiratory failure at the age of 47. NV with both methods successfully corrected nocturnal hypoxemia, improved daytime arterial blood gas values, and achieved a stable clinical course without marked deterioration for four years. Daytime PaO2 higher than 60 Torr and PaCO2 lower than 70 Torr while breathing room air were maintained with both methods, whereas PaO2 was lower than 50 Torr and PaCO2 higher than 70 Torr before the implementation of NV. TIPPV was safely suspended repeatedly for as long as two weeks, maintaining daytime PaO2 higher than 50 Torr. NIPPV-C was also repeatedly suspended for two weeks. Occasionally PaO2 dropped as low as 40 Torr after periods without NV; however, it was restored to higher than 60 Torr after one or two nights' NIPPV-C. These facts suggest that NV had a restorative effect on respiratory muscle fatigue in the present case. While on NIPPV-C, nighttime SaO2 was higher than 90% for 94% of the total time, and between 80% and 90% for the remaining 6% of the time. Desaturation for short periods was thought to be due to oral air leakage, which made the method slightly less effective than TIPPV. However, the overall clinical effectiveness of NIPPV-C was comparable to that of TIPPV.(ABSTRACT TRUNCATED AT 250 WORDS)

Chronic Disease↗
PubMed1991

Assessment of age-dependent changes in circadian blood pressure rhythm in patients with essential hypertension.

The effects of age on the circadian blood pressure rhythm of patients with untreated essential hypertension (n = 133, World Health Organization stage I or II) were compared with those of normotensive subjects (n = 91). Subjects were classified into three groups by age: young (less than 40 years old), adult (40-59 years old) and old (greater than or equal to 60 years old). Blood pressure was monitored every 5 min for 24 h, using a finger volume oscillometric device under fixed external conditions. The single cosinor method was used to evaluate circadian rhythm. There was no difference in the amplitude of circadian systolic or diastolic blood pressure rhythm among the different normotensive and essentially hypertensive age groups although a wide distribution of amplitude was noted within each group. The distribution of amplitude was wider in the hypertensive than in the normotensive groups. The amplitude of circadian blood pressure rhythm was independent of the mesor level. On the other hand, the amplitude of circadian heart rate rhythm decreased with increasing age both in normotensive subjects (P less than 0.05, young versus adult or old) and hypertensive patients (P less than 0.01, young and old versus adult). The acrophase of circadian systolic blood pressure rhythm in young hypertensives was greater than that in adult or old hypertensives (P less than 0.05, for both). Such age-dependent changes were not observed in the normotensive groups. Consequently, the acrophase of circadian systolic or diastolic blood pressure rhythm in young hypertensives was larger than that in young normotensives (P less than 0.05, for both systolic and diastolic blood pressure).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Synthesis of rat parathymosin alpha fragment 1-28 and examination of its inhibitory activity towards the restoring activity of thymosin alpha 1 on the impaired T-lymphocytes of uremic patients.

A fragment corresponding to N-terminal octaeicosapeptide of rat parathymosin alpha was synthesized by assembling 5 peptide fragments, followed by deprotection with 1 M trifluoromethanesulfonic acid-thioanisole (molar ratio 1:1) in trifluoroacetic acid in the presence of dimethylselenium. Incubation of impaired T-lymphocytes isolated from uremic patients with the synthetic parathymosin alpha fragment 1-28 showed no immunological restoring effect, but when it was administered together with thymosin alpha 1, it appeared to suppress the restoring effect of the thymosin alpha 1 on the impaired T-lymphocytes of uremic patients.

Amino Acid Sequence↗
PubMed1991

Synthesis of an immunologically active fragment analog of prothymosin alpha with enhanced enzymatic stability.

A fragment analog, [D-Arg30]prothymosin alpha fragment 1-30, containing D-arginine in place of arginine residue at position 30 was synthesized by the liquid phase procedure and studied for immunological effect on the impaired blastogenic response of T-lymphocytes isolated from uremic patients after treatment of human serum. Deacetyl-thymosin alpha 1, a synthetic octaeicosapeptide corresponding to deacetyl-prothymosin alpha fragment 1-28, has restoration ability for the impaired blastogenic response of T-lymphocytes of uremic patients but is susceptible to proteolytic digestion. On the other hand, the fragment analog, [D-Arg30]prothymosin alpha fragment 1-30 retained activity and was shown to exhibit a high degree of stability when incubated in human serum. These results indicate that N-terminal acetylation and the introduction of D-residue into the C-terminal residue of prothymosin alpha fragment 1-30 increase resistance to proteolytic degradation by exopeptidases.

Amino Acid Sequence↗
PubMed1991

Solid-phase synthesis of biologically active fragment 29-111 of rat prothymosin alpha.

Rat prothymosin alpha fragment 29-111, an 83-residue polypeptide corresponding to desthymosin alpha 1-prothymosin alpha, has been synthesized by a solid-phase method. Hydrogen fluoride was used to deprotect and cleave the peptide from the resin. The crude product was purified by gel-filtration, ion-exchange chromatography and high-performance liquid chromatography. A 3.2-mg sample of a ca. 96% pure peptide was finally obtained. The overall yield of the synthesis was less than 1%. An increase of E-rosette-forming lymphocytes was obtained after incubation of peripheral blood from uremic patients with the synthetic prothymosin alpha fragment 29-111. The restoring effect of the synthetic prothymosin alpha fragment 29-111 was greater than that of our synthetic thymosin alpha 1.

Amino Acid Sequence↗
PubMed1991

[Blood kinetics of free-platinum in CDDP hepato-arterial injection therapy].

In CDDP hepato-arterial injection therapy, platinum (Pt) concentration in hepatic and peripheral venous blood were determined in two groups with different injection rates, and the blood kinetics of Pt was examined. Seven cases of digestive cancers having liver metastases were given CDDP (100 mg) selectively into the proper hepatic artery at a constant rate (10 or 40 min). After injection, concentration of non-protein-bound Pt in hepatic and peripheral venous blood were determined. Pt concentration and AUC value were higher in hepatic venous blood at injection rate than peripheral venous blood. On the other hand, Pt concentration in hepatic venous blood in the cases 10 min-injection were higher than those received 40 min-injection, but neither Pt concentration in peripheral venous blood nor incidences of the side effects and abnormal clinical findings were influenced by the injected rates.

Adult↗
PubMed1990

Characteristics of activation of rat mast cells by polyethylenimines and a polyallylamine: effects on the release of histamine and of arachidonate and its metabolites.

1. Three polyethylenimines and one polyallylamine released radioactivity from rat peritoneal mast cells labeled with [1-14C]arachidonic acid and concomitantly released histamine from the cells. 2. This enhancement of the release of radioactivity was inhibited by phospholipase A2 inhibitors, quinacrine (1 mM) and p-bromophenacyl bromide (10 microM), suggesting that polyethylenimine and polyallylamine activates phospholipase A2 to generate arachidonate and its metabolites. 3. The effects of H-7 or K-252a, general kinase inhibitors for the release of histamine and of arachidonate and its metabolites induced by the polycations, were different from those of W-7, a calmodulin inhibitor. The mechanisms to generate arachidonate and its metabolites seemed to differ from those to release histamine; activation of phospholipase A2 by the polycations was calmodulin-dependent. 4. p-Bromophenacyl bromide inhibited the histamine release induced by polyethylenimines and a polyallylamine, suggesting that arachidonate production by means of phospholipase A2 activation by polycations is an important process in the release of histamine from mast cells.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1990

The modulatory effects of phorbol esters on histamine release from mast cells induced by a polyethylenimine and a polyallylamine.

1. Histamine release from rat peritoneal mast cells induced by polyethylenimine (mol. wt = 600) was inhibited by phorbol 12-myristate 13-acetate (PMA) and phorbol 12,13-dibutyrate (PDBu), but not by 4 alpha-phorbol 12,13-didecanoate (4 alpha-PDD). 2. Histamine release induced by polyallylamine (mol. wt = 10,000) was enhanced by PMA and PDBu, but not by 4 alpha-PDD. 3. K-252a reduced the inhibitory effect of PMA on histamine release induced by polyethylenimine and its enhancing effect on histamine release by polyallylamine.

Animals↗
PubMed1990

Comparison of histamine release induced by synthetic polycations with that by compound 48/80 from rat mast cells.

We compared the histamine release induced by polyethylenimines and polyallylamines with that induced by compound 48/80. Lidocaine inhibited the histamine release induced by polyethylenimine with a molecular weight of 600 (PEI6), but disodium cromoglycate did not. The histamine releases induced by all polyethylenimines and polyallylamines tested were inhibited by lidocaine, but not by disodium cromoglycate. Islet activating protein inhibited the histamine release induced by PEI6. Its effects on the release by other polyethylenimines and polyallylamines were less than that on PEI6. It is likely that the inhibition of G proteins by islet activating protein resulted in a decrease of the histamine release. This possibility was supported by the finding that guanyl-5'-(beta, gamma-imino) triphosphate enhanced the histamine release. An inhibitor of polyphosphoinositide phosphodiesterase, neomycin, did not affect the histamine releases induced by these polymers. The effect of PEI6 seemed to resemble that of compound 48/80. After pretreatment of mast cells with wheat germ agglutinin and with Limax flavus agglutinin, releases of histamine induced by PEI6 and compound 48/80 decreased, suggesting that the binding sites of PEI6 and compound 48/80 had sialic acid and/or N-acetyl glucosamine residues. The binding site for PEI6 seemed to especially overlap those of compound 48/80.

Animals↗