A rapid method for the separation of rat pancreatic islets from collagenase-digested pancreas using Percoll

The isolation of pancreatic islets from collagenase-digested Wistar rat pancreas was shown by the sedimentation method at a unit gravity using Percoll solution with a density of 1.041 g/ml. The density of digested exocrine tissues was in the range of 1.013-1.041 g/ml, while that of purely isolated islets was in the narrow range of 1.066-1.075 g/ml. More than a hundred islets were obtained freely from each rat pancreas without any gross contamination of digested exocrine tissues. A significant increase was observed in glucose-stimulated insulin release from islet isolated with Percoll in the same pattern as that without Percoll. In addition to the well preserved morphology and function of pancreatic islets isolated by Percoll, the simplicity of the technique strongly commends the usefullness of this method.

Biomedical applications of magnetic fluids II. 1) preparation and magnetic guidance of magnetic albumin microsphere for site specific drug delivery in vivo

Magnetic guidance of magnetic albumin microsphere for site specific delivery was investigated in mice and rats. After intravenous injection in mice, magnetic microspheres with 1 and 3 micrometer diameter size were localized and retained in the target-site (lung) by application of two permanent magnets to the lungs. Injection into the renal artery in rats also indicated that the 1-micrometer microspheres were concentrated in the kidney by a magnetic field. When the magnets were not applied, however, the microspheres following intravascular injection were concentrated mainly in the liver, regardless of the route of administration. Such preferential localization by magnetic means suggested that magnetic albumin microspheres could become effective drug carriers with site specificity for the delivery of chemotherapeutic agents in cancer therapy.

Hypotensive response to angiotensin II analogue and angiotensin I converting enzyme inhibitor in pseudo-Bartter's syndrome

We studied the effect of angiotensin II analogue (AII-A) and angiotensin I converting enzyme inhibitor (SQ 14,225) on blood pressure and the renin-angiotensin-aldosterone system in a patient with pseudo-Bartter's syndrome, who was a 26-year-old unmarried Japanese woman taking furosemide surreptitiously. The intravenous infusion of AII-A decreased blood pressure from 85/35 to 68/28 mmHg. This decrease in blood pressure was associated with an increment of plasma renin activity (PRA) and a decrement of plasma aldosterone concentration (PAC). Similarly, SQ 14,225 given orally decreased blood pressure to the same extent. An increment of PRA and a decrement of PAC were also observed. These results suggest that the renin-angiotensin system plays a considerable role in maintaining blood pressure in pseudo-Bartter's syndrome. Again, attention has to be paid to the possibility of surreptitious use of diuretics in an adult patient with persistent hypokalemic alkalosis, hyperactivity of the renin-angiotensin-aldosterone system and angiotensin II insensitivity simulating "true" Bartter's syndrome.

Biomedical applications of magnetic fluids. i. Magnetic guidance of ferro-colloid-entrapped albumin microsphere for site specific drug delivery in vivo

Magnetic guidance of magnetic albumin microsphere for site specific drug delivery was investigated in vivo. After intravenous injection in mice, magnetic microspheres localized in the site (lung) at which two permanent magnets were placed. Injection into the renal artery in rats also indicated that the microspheres were concentrated at the kidney by a magnetic field. When magnet was not applied, however, the microspheres were concentrated mainly in the liver. Such preferential localization by magnetic means suggested that magnetic albumin microspheres could become effective drug carriers with site specificity for the delivery of chemotherapeutic agents in cancer therapy.

Non-invasive localization of the pre-excitation site in patients with the Wolff-Parkinson-White syndrome. Vectorcardiographic and echocardiographic correlations

Vectorcardiographic and echocardiographic correlations were made in 160 patients with no clinical evidence of cardiovascular diseases except for the Wolff-Parkinson-White syndrome. Frank vectorcardiographic classifications of the patients were based on both the morphology of the delta loop and the direction of the mean delta vector in the horizontal plane as follows; group I (93 patients) with a delta loop inscribed nearly straightly anteriorly and either to the left or right and a mean delta vector directed more anteriorly than +20 degrees, group II (31 patients) with a hook-shaped delta loop inscribed initially anteriorly but soon posteriorly and to the left, and group III (36 patients) with a delta loop inscribed nearly linearly to the left and either posteriorly or slightly anteriorly and a mean delta vector directed more posteriorly than +20 degrees. Abnormal echocardiographic patterns of ventricular contractions in the syndrome were seen at the left ventricular posterior wall (LVPW), the interventricular septum (IVS), and the right ventricular anterior wall (RVAW). In group I abnormal LVPW motions were observed in 91 patients (98%), and both abnormal LVPW and IVS motions in 1. The remaining 1 showed no echocardiographic abnormalities either at LVPW or IVS. In contrast, abnormal IVS motions were observed in 29 patients (94%) of group II. No patient of group II showed abnormal LVPW motions. In 17 patients (47%) of group III abnormal LVPW motions alone were observed. Two patients showed both abnormal LVPW and IVS motions. In the remaining 17 patients (47%), no abnormal motions were noted either at LVPW or IVS. Abnormal RVAW motions were invariably observed in 19 patients of group II with satisfactory RVAW echograms, but never seen in groups I and III. Above findings could be explained by the pre-excitation at LVPW in group I, RVAW in group II, and posterior right ventricle in group III. In 19 patients (8 in group I and 11 in group III) frontal QRS loops were very similar to that in left anterior hemiblock. All of these patients except for 1 showed abnormal LVPW motions, so that the site of pre-excitation was presumably located at the posterior paraseptal region or the posterior IVS. Three cases with a combination of a frontal QRS loop of left anterior hemiblock pattern and abnormal IVS motions in addition to abnormal LVPW motions may be explained by the pre-excitation at the right-sided IVS near LVPW. We feel that combinations of vectorcardiographic and echocardiographic approaches are clinically quite useful as an auxiliary non-invasive means of locating the pre-excitation site.

Comparison of Frank-vectorcardiograms of normal conduction and right bundle branch block in patients with intermittent or transient right bundle branch block

For the purpose of obtaining fundamental data to make the diagnostic criteria for coexisting electrocardiographic abnormalities in right bundle branch block (RBBB), the Frank-vectorcardiographic and electrocardiographic parameters were studied in both normal and RBBB conductions in 25 patients (16 males and 9 females, aged 6 to 78 years) with intermittent or transient RBBB. There were no statistically significant differences in the corresponding instantaneous QRS vectors between normal and RBBB conductions during the first 10.4 (+/- 3.2) msec of the QRS duration on the average. No statistically significant differences existed in the mean Q amplitudes of the Frank leads between normal and RBBB conductions. After the development of RBBB, voltages of Rx and Ry, and the planar maximum QRS vectors decreased approximately by 10% on the average, and Rz decreased significantly by 63.9% on the average, and S amplitudes of the 3 Frank leads increased significantly. We observed 3 patients showing a complete reversal of the sense of inscription of the horizontal QRS loop from counterclockwise to clockwise after the development of RBBB. Two of these patients showed no clinical evidence of cardiac or pulmonary diseases except for RBBB. After the appearance of RBBB, maximum T vectors deviated significantly posteriorly in the horizontal and left sagittal planes. Twenty-three patients showed counterclockwise inscription of the T loop both in the horizontal and left sagittal planes, and 9 patients in the frontal plane. After the development of RBBB, we observed a complete reversal in the sense of inscription of the T loop from counterclockwise to clockwise in 13 cases (56.5%) in the horizontal plane, in 15 cases (65.2%) in the left sagittal plane, and in 8 cases (88.9%) in the frontal plane.

Hydrolysis of flavin adenine dinucleotide and flavin mononucleotide by rabbit blood

Hydrolysis of FAD and FMN by rabbit blood was studied. The whole blood hydrolyzed both FAD and FMN to riboflavin. Blood plasma hydrolyzed FAD rapidly to FMN, but hydrolyzed FMN slowly to riboflavin. On the other hand, red cells hydrolyzed FAD slowly to FMN, but hydrolyzed FMN rapidly to riboflavin. These facts are explained by the localization of respective enzymes in blood plasma and cells.

Echocardiographic evaluation of right ventricular anterior wall motion in the Wolff-Parkinson-White syndrome

Echocardiographic motions of right ventricular anterior wall (RVAW) were investigated in 71 patients with Wolff-Parkinson-White (WPW) syndrome. According to the criteria of Rosenbaum et al the electrocardiograms were classified as type A in 35 patients and type B in 36. Sixteen type B patients exhibited abnormal RVAW motion, which was characterized by an early onset of the posterior movement before S1 andl also by a premature peak formation before S2. A small step or hump nearly coincident with S1 was observed in 10 of these 16 patients. These findings seem to suggest that both contraction and relaxation of RVAW begin earlier than normal due to anterior right ventricular pre-excitation. RVAW motion was normal in all of type A patients. Echocardiographic investigation of RVAW motion appears to be useful in non-invasive estimation of the site of pre-excitation, especially in type B WPW patients.

Insulin delivery rate in response to glucose infusion in normal and diabetic subjects

The insulin delivery rates were estimated in 8 normal and 8 diabetic subjects from the results of peripheral insulin response to a single bolus iv injection of glucose, taking account of fractionally removed insulin. The delivered insulin response to 0.5 g/Kg body weight of glucose injection was biphasic in normal and diabetic subjects. In normal subjects, 1.7 +/- 0.3 U of insulin was delivered during the first phase (0-10 min) and 5.6 +/- 1.6 U during the second phase (11-60 min). In diabetic subjects, 0.4 +/- 0.2 U of insulin was delivered during the first phase and 1.8 +/- 0.5 U during the second phase. The amounts of delivered insulin during the first and second phases were significantly decreased in diabetics (p less than 0.01). The insulin delivery rates during the first and second phases fitted by the same line to the glucose concentration at each period. This suggests that a common glucoreceptor or glucose-mediated signal of the insulin response might exist during both phases. The glucose-insulin response curves in mild diabetics seemed to be similar to those in the normals, but shifted toward higher glucose levels. This finding suggests that the decreased glucose sensitivity of pancreatic beta cells in mild diabetics can be corrected by high glucose concentrations.

Characterisation of the effect of intravenous infusion of glucose and tolbutamide on the insulin delivery rate in man

Serum insulin response to a single bolus of IV glucose or tolbutamide was measured in eight healthy subjects. Insulin disappearance rate was assessed by deconvolution from the serum insulin levels, using the measured insulin disappearance rate. The mean rate constant of insulin disappearance was 0.238 +/- 0.005 min-1 (mean +/- SEM). Basal insulin delivery rate was 8.0 to 9.0 mU/min and the delivery rate following glucose injection (0.5 g/kg body weight) showed a biphasic response, whereas that after tolbutamide injection (15.6 mg/kg body weight), a monophasic response. After glucose injection, 1.7 +/- 0.3 U of insulin was delivered during the first phase (0--10 min) and 5.6 +/- 1.6 U during the second phase (11--60 min). After tolbutamide injection, 1.5 +/- 0.3 U of insulin was delivered during the first 10 min. Between 11 and 40 min, 1.6 +/- 0.5 U of insulin was delivered. The results thus confirm and also quantitate biphasic insulin secretion after a bolus of glucose with a monophasic response after tolbutamide. The method is suitable for studies of the insulin secretogogues in man.

Metabolism of injected flavins studied by using double-labeled [14C]flavin adenine dinucleotide and [14C, 32P]flavin mononucleotide

The metabolism of flavins in mouse was studied with [F-(2)-14C, A-(2,8)-14C]FAD and [F-(2)-14C, 32P]FMN. Ninety minutes after injection, radioactive isoalloxazine nucleus of double-labeled FAD was markedly incorporated into FAD, FMN and riboflavin in the liver, whereas a small amount of radioactive adenine nucleus of double-labeled FAD was found in FAD in the liver. In the case of FMN, radioactive isoalloxazine nucleus of double-labeled FMN was markedly incorporated into FAD, FMN and riboflavin in the liver, whereas only a minute amount of radioactive phosphorus was incorporated into FMN and FAD in the same organ. These results indicate that FMN and FAD injected are rapidly hydrolyzed and resynthesized in animal body.

Clinical studies on dissolution of gallstones using ursodeoxycholic acid

Ursodeoxycholic acid (UDCA), 7beta hydroxy epimer of chenodeoxycholic acid (CDCA), has been used as a choleretica for 20 years in Japan. Recent report showing increased excretion of UDCA in bile after CDCA administration may suggest the possibility that UDCA has similar effects to CDCA on bile cholesterol unsaturation and on gallstone dissolution. The present paper describes the clinical usefulness of UDCA for gallstone patients during the past two years. Seventy-four gallstone patients with functioning gall-bladders, 19 men and 55 women with a mean age of 48 years, have been treated for 6 months or more. UDCA, supplied in tablets (Ursosan), was given 450 mg per day. The disappearance or the reduction of stone size or number, or both (dissolution effect) was recognized in 32 out of 74 patients (43%). In case of radiolucent stones, the overall effective rate was estimated for 24 of 46 patients (52%). There may be no significant difference in dissolution effect between CDCA and UDCA treatment, however, the merit of UDCA treatment seems to have its few side effects.

Echocardiographic patterns of ventricular contraction in the Wolff-Parkinson-White Syndrome

Echocardiograms of 52 patients with the Wolff-Parkinson-White (WPW) syndrome were investigated. Abnormal patterns of motion were observed in the left ventricular posterior wall (LVPW) and the interventricular septum (IVS). The abnormal LVPW motion was presumably specific for the syndrome and included early onset of the anterior motion which preceded the first heart sound (S1) and a premature peak formation of the anterior displacement which occurred before the second heart sound. The latter was usually followed by a second lower peak. These findings seem to suggest that both contraction and relaxation of LVPW begin earlier than normal due to ventricular pre-excitation initiated at or near the LVPW. The IVS abnormality characteristic of the syndrome was a posterior protrusion, the onset of which preceded S1. Subsequent motion of IVS was either paradoxical or hypokinetic during ejection. These IVS abnormalities were quite similar to those observed in left bundle branch block. The abnormal LVPW motion was observed in all 20 Type A patients and 10 of the 32 Type B patients. The abnormal IVS motion was observed in 10 Type B patients. We feel that echocardiography could be used as an auxiliary noninvasive means of locating the pre-excitation site in patients with WPW.

[Anti-inflammatory action of 2-(2-fluoro-4-biphenylyl) propionic acid (flubiprofen]

2-(2-fluoro-4-biphenylyl) propionic acid (flurbipofen, FP-70), a newly synthesized anti-inflammatory agent, was examined for its effects and then compared with the actions of other standard drugs. Inhibition of capillary permeability in mice: the activity of FP-70 was 7.8 times as potent as ibuprofen (IP), 61 times that of acetylsalicylic acid (AS), 5.7 times that of indomethacin (IM) and 25 times that of phenylbutazone (PB). Inhibition of carrageenin-induced edema in rat paw: the activity of FP-70 was 52 times as potent as IP, 250 times that of potent as AS, 14 times that of potent as IM and 110 times that of potent as PB. Inhibition of heat-induced coagulation of BSA: the activity of FP-70 showed the marked effects much the same as IP. In adrenalectomized rat, FP-70 was also effective. Inhibition of the ultra-violet erythema in guinea-pigs, the activity of FP-70 was 26 times as potent as IP, 790 times that of AS, 25 times that of IM and 68 times that of PB. Regarding the inhibition of CMC induced pouch in rats, the potency of FP-70 was to the same degree as that of predonisolone. In adjuvant induced arthritis in rats, FP-70 reduced and cured inflammatory syndromes and activity was the same or more effective than that of IM. From these results, FP-70 appears to be a most potent nonsteroidal anti-inflammatory agent.

Population distribution of Frank-vectorcardiographic measurements of healthy Japanese men

For elucidation of the type of population distribution of Frank-vectorcardiographic items of normal Japanese population, forty-eight measurements were obtained from 364 healthy Japanese men in the fourth decade. These measurements were studied with Fisher's g test of normality of population distribution, which showed that normal population distribution could be assumed in only six items (12.5%)-the maximal QRS vector angle and the directional QRS-T angle in the frontal plane, RX and TZ height, OZ duration, and anteorior accession time. The frontal maximal T vector angle was regarded to have an approximately normal population distribution. In the remaining forty-one items logarithmic normalization of distribution was attempted with a transformation formula, Y=Log10 (kX+c). Being applied to Y's, the variate logarithm-transformed with an appropriate value of c, Fisher's g test accepted the null hypothesis of normality of population distribution in 27 items (56.3%); in other words, the population distribution of 27 items was lognormal. These included the magnitudes of maximal QRS and T vectors and T/QRS ratios in the three projection planes, and some of vector angles. The population distribution was usually lognormal in scalar amplitudes and ratios except for items related to Q and S waves in leads X and Y. Bimodality of distribution was seen in six items (12.5%), which consisted of the maximal QRS vector angle and the QRS-T angles in the horizontal and left sagittal planes. In these planes the maximal QRS vector and the directional QRS-T angles showed biomodality attributed to combination of two normal distributions. Three of the four QRS-T angles in these planes and also the horizontal maximal QRS vector angle were lognormalized, although a lesser degree of bimodality still remained after seemingly successful logarithmic transformation in respect to the tg statistics. Chi-square test accepted the null hypothesis of exponential population distribution in four items (8.4%), which included the depth of QX, SX, and SY, and S/(S+R) ratio in lead Y. Exponential approximation appeared much better than normal one in the rest of measurements related to Q and S waves in leads X and Y. The following conclusions were drawn from the present study: i) statistical tests based on normal population distribution should be carefully applied to Frank-vectorcardiographic measurements of healthy Japanese men in the fourth decade and, presumably, of healthy Japanese adults regardless of age and sex; and ii) logarithmic transformation is an efficient means to normalize a skewed distribution in the majority of measurements.

Studies on myoinositol. Effects of caffeine and theophylline on incorporation of myoinositol into phosphatidylinositol in rat liver homogenate

Both caffeine and theophylline, which were known to be potent inhibitors of cyclic-AMP phosphodiesterase, stimulated the incorporation of myoinositol into phosphatidylinositol in rat liver homogenate. However, cyclic-AMP had no effect. The effect of dibutyryl-cyclic-AMP differed with different concentrations. These results suggest that the stimulation cannot be explained by the increase in the amount of cyclic-AMP. This view was supported by the fact that papaverine, cyclic-AMP phosphodiesterase inhibitor, did not stimulate the incorporation and imidazole, the phosphodiesterase stimulator, did not inhibit the incorporation, and that adenylcyclase stimulators, epinephrine and glucagon, did not stimulate the incorporation.