In vivo microdialysis for pharmacokinetic investigations: a plasma protein binding study of valproate in rabbits

The use of microdialysis to study the binding of valproate (VPA) to plasma proteins was evaluated in rabbits. Prior to an in vivo microdialysis, in vitro relative recovery of VPA respectively from Ringer's solution, 5% (w/v) of albumin solution and plasma sample via a microdialysis probe was examined. The in vitro relative recovery was defined as a ratio of the VPA concentration determined in the dialysate to the free VPA concentration in the sample solution surrounding the membrane of the microdialysis probe. When the sample solution was well stirred at 700 rpm and maintained at 37 degrees C, the in vitro relative recovery of VPA was significantly different among them. It increased in the order of Ringer's solution (34.3 +/- 2.6%) > 5% (w/v) of albumin solution (25.7 +/- 4.6%) > rabbit plasma sample (15.8 +/- 1.2%). Thereafter, pharmacokinetics of VPA was determined using both microdialysis sampling via the rabbit femoral vein and collection of whole blood via the rabbit ear vein after intravenous administration of VPA at a dose of 43 mg/kg. Free concentrations of VPA in plasma were determined by ultrafiltration method as opposed to microdialysis method. There was no difference in the elimination half-life of VPA determined by microdialysis, 1.09 +/- 0.22 h, or ultrafiltration, 1.22 +/- 0.21 h. The AUC of VPA in dialysate was 15 +/- 4 micrograms.h/ml, which corresponded to 15% of that in ultrafiltrate (103 +/- 17 micrograms.h/ml). The value was in good agreement with the in vitro relative recovery of VPA from plasma sample (15.8 +/- 1.2%).(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of short axial blood flow pattern in thoracic descending aorta by use of tagging cine magnetic resonance

The authors, for the first time, evaluated the short axial blood flow profile by using tagging cine magnetic resonance (MR). Cine MR was performed on 15 healthy volunteers aged 51.5 +/- 23.1 (SD) years. The transverse plane of the thoracic descending aorta was imaged at the middle level of the left ventricle. Two or four radial tags, whose thickness was 3 mm width each, were established to the short axial image of the descending aorta at 2 msec and 300 msec following the R wave of the subjects' QRS complex on the electrocardiogram. They observed the flow patterns and measured the rotating flow velocity of the thoracic descending aorta in early systole and late systole from the following formula: v = d/t, (v = velocity, d = displacement of tags over the interval, t = time interval between the time of presaturation and the time of imaging). In the short axial image of the descending aorta, 13 subjects showed the clockwise rotation of tags in the supine position from the foot side view. Flow image of the other 2 subjects showed as undefined. Rotating flow velocity was 1.63 +/- 0.88 cm/sec in early systole and was 1.37 +/- 1.11 cm/sec in late systole. Tagging cine MR is useful to evaluate the blood flow profile in the thoracic descending aorta.

Aldecalmycin, a new antimicrobial antibiotic from Streptomyces. I. Taxonomy, fermentation, isolation, physico-chemical and biological properties

A new antibiotic, aldecalmycin, has been discovered in the culture broth of Streptomyces sp. MJ147-72F6. Aldecalmycin was purified by solvent extraction, Diaion HP-20 chromatography, silica gel chromatography, Sephadex LH-20 chromatography, HPLC and centrifugal partition chromatography. The 1H and 13C NMR spectra of aldecalmycin showed the presence of keto-enol tautomers. Aldecalmycin is equipotent in inhibiting the growth of sensitive and methicillin-resistant Staphylococcus aureus (MRSA).

Expression of antral gastrin and somatostatin mRNA in Helicobacter pylori-infected subjects

OBJECTIVES

We investigated the gene expression of antral gastrin and somatostatin in Helicobacter pylori-infected subjects. Twelve asymptomatic men with normal endoscopic findings participated in this study, four of whom were infected with H. pylori.

METHODS

Biopsy specimens of the gastric mucosa were obtained after subjects had fasted overnight. Serum gastrin levels, antral gastrin and somatostatin content, and antral G- and D-cell densities also were measured.

RESULTS

Fasting serum gastrin levels were significantly higher in H. pylori-positive subjects than in H. pylori-negative subjects. There were no differences between groups in antral gastrin content, G-cell density, or gastrin mRNA levels. Antral somatostatin content, D-cell density, somatostatin mRNA levels, and the somatostatin mRNA:D-cell density ratio were significantly decreased in H. pylori-positive subjects.

CONCLUSIONS

Our results suggest that in addition to reduced antral D-cell density, a suppression of somatostatin synthesis in D-cells may have contributed to the decrease in antral somatostatin in H. pylori-infected subjects.

Maturation-related biochemical changes in swine anterior cruciate ligament and tibialis posterior tendon

In order to determine the differences between ligaments and tendons in terms of change in biochemical composition during maturation, the biochemical characteristics of the anterior cruciate ligament and tibialis posterior tendon of swine were studied. The collagen content of the tibialis posterior tendon was found to increase rapidly with growth of the body, reaching a plateau prior to maturation. In contrast, the rate of increase in the anterior cruciate ligament was slow, indicating that maturation of this tissue is delayed. The quantity of glycosaminoglycan in both the anterior cruciate ligament and the tibialis posterior tendon decreased with growth. In mature animals, glycosaminoglycans in the anterior cruciate ligament included chondroitin sulfate, hyaluronic acid, and dermatan sulfate, but only trace amounts of chondroitin sulfate were found in the tibialis posterior tendon. Although the ratio of dermatan sulfate to hyaluronic acid generally increased with growth, this increase was more conspicuous in the tibialis posterior tendon than in the anterior cruciate ligament. The anterior cruciate ligament and tibialis posterior tendon both contained collagen of types I, III, and V. In mature swine, type III was increased in the anterior cruciate ligament but not in the tibialis posterior tendon. These findings demonstrate slower maturation for ligament than for tendon with regard to the changes in biochemical constituents, especially those in collagen type and glycosaminoglycan, during the growth process, and also suggest that the composition of these tissues changes in accordance with their changing functional requirements.

Isolated congenital left ventricular diverticulum in an adult. A case report

A sixty-three-year-old man presented himself with atrial flutter and congestive heart failure. Cardiac catheterization revealed that left ventricular diverticulum was located on the anterobasal wall with narrow connection to the left ventricular cavity. Coronary angiography revealed normal coronary arteries. The patient had been asymptomatic until adult life with no other thoracoabdominal or cardiac anomalies. This is an extremely rare finding in the adult population.

Inhibitory effect of interleukin-2 on histamine release from rat mast cells

Interleukin-2 (IL-2) inhibited histamine release from rat mast cells induced by compound 48/80 in a concentration-dependent manner. The inhibitory effect of IL-2 on histamine release was also dependent on the length of the incubation period; the maximum inhibition was achieved at 8 h after IL-2 addition. Furthermore, IL-2 inhibited not only IP3 production but also 45Ca uptake in mast cells stimulated by compound 48/80. Since IL-2 enhanced [3H]-leucine uptake into mast cells, this suggests that protein synthesis may be related in some way with the inhibition of histamine release. IL-2 treatment augmented the synthesis of a protein having a molecular weight of approximately 35 kDa. From Western blotting analysis, it became clear that the production of lipocortin-I was augmented in rat mast cells by IL-2 treatment. The present study shows that IL-2 induces the synthesis of lipocortin-I in mast cells and that lipocortin-I may play some role in inhibiting histamine release from mast cells.

Novel antibiotics, amythiamicins. I. Taxonomy, fermentation, isolation, physico-chemical properties, and antimicrobial activity

Novel antibacterial antibiotics, amythiamicins A, B, C and D, have been isolated from the fermentation broth of Amycolatopsis sp. MI481-42F4. In this paper, the taxonomy of the producing strain, fermentation, isolation, physico-chemical properties and biological activities of amythiamicins are reported. Amythiamicins inhibit the growth of Gram-positive bacteria including multi-drug resistant strains.

[Clinical usefulness of serum assay of EIA-CYFRA 21-1 in lung cancer]

Enzyme immunoassay CYFRA 21-1, a novel lung tumor marker presented in serum (upper limit of normal values: 3.5 ng/ml) was measured in 84 patients with lung cancer and 141 patients with benign respiratory diseases. The positive rate for CYFRA 21-1 in primary lung cancer was 70.3% and the false positive rate in respiratory diseases was 24.1%. In respect to the histological types of lung cancer, CYFRA 21-1 was elevated in 85.0% of squamous cell carcinoma and in 64.8% of other cell types of primary lung cancer. Elevated CYFRA 21-1 levels were found in 40% of Stage I-II, in 80.0% of Stage IIIA-B, and in 73.5% of Stage IV. The overall diagnostic efficiency was 53.4% for CYFRA 21-1 and 44.5% for CEA, respectively. Receiver operating characteristic (ROC) curve analysis suggested that CYFRA 21-1 test has an advantage over CEA. From the results of this study, CYFRA 21-1 was more efficient than CEA as primary diagnostic marker in lung cancer.

Cytostatin, a novel inhibitor of cell adhesion to components of extracellular matrix produced by Streptomyces sp. MJ654-NF4. I. Taxonomy, fermentation, isolation and biological activities

Cytostatin has been identified as a novel inhibitor of cell adhesion to components of extracellular matrix (ECM) in cultured broth of Streptomyces sp. MJ654-NF4. Though cytostatin did not inhibit EL-4 cell adhesion to ECM components such as laminin and fibronectin; it inhibited the adhesion of B16 melanoma cells to laminin and collagen type IV but not to fibronectin. It exhibited antimetastatic activity on B16 melanoma cells in mice. The cytotoxicity of cytostatin are also reported.

Labeling of v-Src and BCR-ABL tyrosine kinases with [14C]herbimycin A and its use in the elucidation of the kinase inactivation mechanism

The ansamycin antibiotic, herbimycin A, selectively inactivates cytoplasmic tyrosine kinases, most likely by binding irreversibly to the reactive SH group(s) of kinases. To further investigate the mechanism of herbimycin A action, we attempted to label tyrosine kinases with [14C]herbimycin A. p60v-src and p210BCR-ABL in immune complexes were labeled with [14C]herbimycin A, demonstrating that the antibiotic binds directly to tyrosine kinases. Digestion of [14C]herbimycin A-labeled p60v-src with Staphylococcus aureus V8 protease revealed that the herbimycin A binding site is within the C-terminal 26-kDa fragment of p60v-src, which contains the tyrosine kinase domain. Herbimycin A treatment inhibited labeling of p60v-src by [14C]fluorosulfonylbenzoyl adenosine, an affinity labeling reagent of nucleotide binding sites, indicating that herbimycin A-modified p60v-src cannot interact with ATP. The results suggest that herbimycin A inactivates tyrosine kinases by binding directly to the kinase domain, thereby inhibiting access to ATP.

Evaluation of aortic distensibility in patients with essential hypertension by using cine magnetic resonance imaging

In order to evaluate the exact distensibility in various parts of aorta in hypertensive patients, the authors performed cine magnetic resonance (MR) in 30 normal control (NC) subjects and 30 hypertensive (HT) patients whose age and sex were matched. Cine MR was carried out at transverse sections in the ascending, descending, and abdominal aorta. Aortic diameter and area were measured in the frames of the maximum and the minimum aortic area. Aortic distensibility was calculated from the following formula: (Max area-Min area)/(Min area x delta P), where delta P is pulse pressure. Cardiac parameters were measured with echocardiography in all subjects. Aortic distensibility was significantly lower in HT patients than in NC subjects at each transverse section (P < 0.01). Minimum diameter index (Min diameter/body surface area) and cardiac function parameter showed no significant differences between NC and HT groups. From these findings, it is suspected that hypertension is a strongly contributing factor that promotes aortic sclerosis.

Contractile dysfunction in the diabetic-rat heart is an intrinsic abnormality of the cardiac myocyte

1. In order to clarify whether the myocardial dysfunction observed in diabetic-rat hearts is an intrinsic property of the myocytes or not, we investigated cardiac function and myocyte contractile function in diabetic rats 5 weeks after the injection of streptozotocin. 2. Maximal and minimal dP/dt and time constant of isovolumic pressure fall were measured using a micromanometer in diabetic and age-matched control rats. 3. Isolated myocytes were enzymically obtained from each rat heart and were stimulated at 1 Hz (37 degrees C) in a buffer containing 1.5 mmol/l Ca2+. The images of myocyte contractions were recorded by a video system. Normalized maximal velocity of shortening (maximal velocity of cell shortening/resting cell length; s-1), normalized maximal velocity of relengthening (maximal velocity of cell relengthening/resting cell length; s-1) and extent of shortening [(twitch amplitude/resting cell length) x 100; %] were analysed by a digitalized computer as contractile functions of the myocyte. 4. The maximal and minimal dP/dt in diabetic rats (7876, 5341 mmHg/s) were significantly lower than those in control rats (9349, 7876 mmHg/s). The time constant of isovolumic pressure fall in diabetic rats (12.7 ms) was significantly greater than that in control rats (8.6 ms). Moreover, the normalized maximal velocity of shortening, normalized maximal velocity of relengthening and extent of shortening in myocytes from diabetic rats (1.40 s-1, 1.38 s-1, 9.5%) were significantly lower than those in myocytes from control rats (1.64 s-1, 1.60 s-1, 11.8%). 5. These results suggest that contractile impairment in this diabetic-rat heart model is mainly due to an intrinsic abnormality of the cardiac myocytes.

Accurate diagnosis of metastatic cardiac leiomyosarcoma with infundibular stenosis and cardiac tamponade by transesophageal echocardiography and Gd-DTPA magnetic resonance imaging--report of a case

We present a patient with metastatic cardiac leiomyosarcoma that was diagnosed antemortem by transesophageal echocardiography (TEE) and ECG-gated magnetic resonance imaging with gadolinium diethylene triaminepentaacetic acid (Gd-DTPA MRI). TEE and Gd-DTPA MRI clearly revealed the morphological characteristics of infundibular stenosis and cardiac tamponade. Our patient has survived about 30 months after cardiac surgery. Since sarcoma is usually associated with a very poor prognosis, surgical treatment should be performed as soon as possible. TEE with color Doppler imaging and Gd-DTPA MRI are very useful diagnostic methods for determining the precise anatomical characterization of cardiac tumor, and these procedures are prerequisite to precise therapy.

[Intra-ventricular pressure gradient and systolic anterior movement of the mitral valve associated with administration of dopamine in a 91-year-old patient]

A 91-year-old woman had decreased systemic blood pressure accompanied by dyspnea and general fatigue after resection of a face tumor (Merkel cell carcinoma). Dopamine was administered to elevate systemic blood pressure, but it did not sufficiently restore the hemodynamic status. Left ventricular apical aneurysm was observed on echocardiogram. Furthermore, SAM (systolic anterior movement of the mitral valve) was observed on M-mode echocardiogram and a pressure gradient of 34.6 mmHg in the midventricular position was confirmed by continuous wave Doppler using the Bernoulli equation. After volume overload and discontinuation of dopamine, SAM completely disappeared and midventricular pressure gradient markedly decreased. Her general condition improved. Because of the narrowed outflow tract, hypercontractile state induced by beta adrenergic stimulation seemed to be one of the important factors for the genesis of SAM and pressure gradient.

Evaluation of acute myocarditis and pericarditis by Gd-DTPA enhanced magnetic resonance imaging

Gd-DTPA enhanced magnetic resonance imaging was performed in two adult patients with acute myocarditis and pericarditis. Gd-DTPA enhancement seemed to identify the exact cardiac region with the higher degree of inflammation.

Systolic anterior motion of the mitral valve associated with acute myocardial infarction in a 62-year-old patient

A 62-year-old patient was admitted to our hospital for treatment of early gastric cancer. After total gastrectomy, he suffered from anteroseptal myocardial infarction. Systolic anterior motion of the mitral valve which was not observed before surgery was observed during the acute phase of myocardial infarction and completely disappeared 3 weeks after the onset of myocardial infarction. Systolic anterior motion of the mitral valve in this patient may have been caused by changes in left ventricular wall motion during the acute phase of myocardial infarction.

Myocardial scintigraphic characteristics in patients with primary aldosteronism

To evaluate the difference in myocardial damage between primary aldosteronism and untreated essential hypertension, we performed thallium-201 myocardial single-photon emission computed tomography in 10 patients with primary aldosteronism and 10 patients with essential hypertension who were matched for age, sex, blood pressure, and the severity of left ventricular hypertrophy for primary aldosteronism. From the analysis of thallium-201 myocardial scintigraphy, extent score was calculated. Extent score was significantly higher in primary aldosteronism than in essential hypertension (45.8 +/- 23.5% versus 9.5 +/- 7.3%, P < .01). After operation, blood pressure significantly decreased, and the precordial voltages (SV1 + RV5) and left ventricular mass indexes were significantly reduced in patients with primary aldosteronism. Extent score was also significantly improved. These results suggest that despite the same severity of myocardial hypertrophy between primary aldosteronism and essential hypertension, the myocardial damage estimated by thallium-201 myocardial scintigraphy is more severe in primary aldosteronism than in essential hypertension. Extent score was useful for evaluation of the severity of myocardial damage in hypertensive patients.