Concurrent on-line sampling of melatonin in pineal microdialysates from conscious rat and its analysis by high-performance liquid chromatography with electrochemical detection

Dynamic changes of melatonin in microdialysates from the pineal gland of a freely moving rat were repeatedly determined by using on-line high-performance liquid chromatography with electrochemical detection. The detection limit for melatonin, ca. 5 pg, was well below that achieved with other systems. We observed a drastic increase of extracellular pineal melatonin during the transitional phase from the light period to the dark period. This application of microdialysis is a useful tool in the study of the physiological role of the mammalian pineal body.

Further studies on D-3-aminoisobutyrate-pyruvate aminotransferase

D-3-Aminoisobutyrate-pyruvate aminotransferase (EC 2.6.1.40, D-BAIB aminotransferase) participates in the metabolism of thymine. Recently we purified this enzyme from rat liver. We have studied D-BAIB aminotransferase further to clarify its physiological function. Among our findings were the following. (1) The enzyme activity was widely distributed in the organs of guinea pigs and rats. The kidney, liver, and lung showed high specific activities. (2) Using the livers of six vertebrates, differences between species were studied. Activity was detected in all species, the human liver showing the lowest activity among them. (3) Developmental study using rat liver showed that the activity was low at birth, increased sharply thereafter for 10 days, and then subsequently declined to the adult level. (4) Intraperitoneal injection of BAIB and beta-alanine in rats was performed to determine whether they induce activity of this aminotransferase. Only BAIB increased the activity of the aminotransferase in the liver significantly. (5) Subcellular distribution study of this aminotransferase in rat liver revealed that it is a mitochondrial enzyme.

Entrapment of left renal vein in children with orthostatic proteinuria

We found that patients with orthostatic protein-uria had entrapment of the left renal vein (LRV) by the aorta and superior mesenteric artery (SMA). Of 15 patients studied, ultrasonographic examination showed 13 cases of typical LRV entrapment with prestenotic dilatation, and 2 cases of mild LRV compression between the aorta and SMA. Intra-arterial digital subtraction angiography and monitoring of pull-back pressure from LRV to the inferior vena cava (IVC) were performed on 2 patients with 4+ proteinuria. Accumulation of contrast medium was seen with mild back-flow to the collateral veins, and pressure gradients between LRV and IVC were 4 mmHg and 8 mmHg, respectively. Eighty school-children formed a control group and were investigated ultrasonically. Nine showed typical LRV entrapment, among whom 3 had moderate to massive orthostatic proteinuria. The discovery of LRV entrapment in patients with orthostatic proteinuria gives definite evidence of LRV congestion and may be possibly a cause of massive protein secretion from the left kidney.

Stability and degradation pattern of cefpirome (HR 810) in aqueous solution

The stability and degradation pathways of a new semi-synthetic cephalosporin, 1-[[(6R,7R)-7-[2-(2-amino-4-thiazolyl)glyoxylamido]-2-carboxy-8-ox o-5-thia-1-azabicyclo[4.2.0]oct-2-en-3-yl]methyl]-6,7-dihydro-5H-1- pyridinium hydroxide, inner salt, 7(2)-(Z)-(O-methyloxime) sulfate (cefpirome sulfate, HR 810), were studied. Cefpirome in various buffer solutions was allowed to stand at 40 degrees C and its degradation patterns were investigated by high performance liquid chromatography. Cefpirome was stable in the region of pH 4-7 and slightly unstable beyond this range. In aqueous solution from the neutral to alkaline regions, the produced degradation products were: 1- [[(6R,7S)-7-[2-(2-amino-4-thiazolyl)glyoxylamido]-2-carboxy-8-oxo -5-thia-1-azabicyclo[4.2.0]oct-2-en-3-yl]methyl]-6,7-dihydro-5 H-1- pyridinium hydroxide, inner salt, 7(2)-(Z)-(O-methyloxime) (epi-cefpirome); 1-[[(6R,7R)-7-[2-(2-amino-4-thiazolyl)glyoxylamido]-2-carboxy-8-ox o-5-thia-1-azabicyclo[4.2.0]oct-3-en-3-yl]methyl]-6,7-dihydro-5H-1- pyridinum hydroxide, inner salt, 7(2)-(Z)-(O-methyloxime) (delta 2-cefpirome); 2-[[(2-amino-4-thiazolyl)((Z)-methoxy-imino)acetyl]amino]acetaldehyde; and 6,7-dihydro-5H-1-pyrindine. On the other hand, 1-[[(6R,7R)-7-[2-(2- amino-4-thiazolyl)glyoxylamido]-2-carboxy-8-oxo-5-thia-1- azabicyclo[4.2.0]oct-2-en-3-yl]methyl]-6,7-dihydro-5H-1-pyridinium++ + hydroxide, inner salt, 7(2)-(E)-(O-methyloxime) (anti-cefpirome), 2-[[(2- amino-4-thiazolyl)-((Z)-methoxyimino)-acetyl]aminomethyl]-1,2,5,7- tetrahydro-7-oxo-4H-furo[3,4-D]-[1,3]thiazine, and 6,7-dihydro-5H-1- pyrindine were produced in strongly acidic solution or under irradiation by artificial sunlight.

Calcium-associated cytoprotective effect of taurine on the calcium and oxygen paradoxes in isolated rat hepatocytes

Our study was designed to determine the calcium and oxygen paradoxes in isolated rat hepatocytes, and to evaluate the cytoprotective effects of taurine on hepatocytes during oxygenation, hypoxia, and on these paradoxes. The calcium and oxygen paradoxes were clearly revealed in isolated rat hepatocytes. As the formation of the superoxide radical was accelerated by the hyperbaric conditions and the calcium ions, drugs such as superoxide dismutase and a calcium channel blocking agent (verapamil), prevented these paradoxes. Taurine decreased the oxygenation-induced lipid peroxidation of hepatocytes, and prevented the hypoxia-induced hepatocyte death in a calcium-containing medium, but not in a calcium-free medium. Taurine also protected the hepatocytes from injuries associated with the calcium and oxygen paradoxes due to the inhibition of sudden calcium influx into the hepatocytes.

[CT-guided biopsy of thoracic mass lesions followed by fast stain technique]

We performed CT-guided needle biopsy of 92 thoracic mass lesions using a Rotex-II screw needle. Fast stain technique was performed for an immediate evaluation of the specimen in the last 39 procedures. The overall accuracy of malignancy was 93.2%, and the correct histological typing was obtained in 82.8% of malignancy proven at surgery or autopsy. The method enabled histopathological diagnosis of thoracic lesions, which could not obtained by other diagnostic modalities including fiberoptic bronchoscopy or fluoroscopy-guided biopsy. The true positive rate increased up 10.2% to 91.3% by introducing fast stain technique. A close cooperation between radiologists and cytopathologists was essential for performing this CT-guided biopsy procedure followed by fast stain technique.

Particle design of tolbutamide by the spherical crystallization technique. III. Micromeritic properties and dissolution rate of tolbutamide spherical agglomerates prepared by the quasi-emulsion solvent diffusion method and the solvent change method

With the objective of modifying the micromeritic properties of tolbutamide (i.e., to manufacture a highly functional powder form), particle design was attempted using a quasi-emulsion solvent diffusion (QESD) method, and the micromeritic properties and dissolution rate of the obtained spherical agglomerates were evaluated by comparison with agglomerates prepared by the solvent change (SC) method. For the production of tolbutamide agglomerates by the QESD method, a necessary condition was the addition of a sucrose fatty acid ester to the system as an emulsifying agent. The particle diameter of the agglomerates obtained by the QESD method depended on the size of the initially formed quasi-emulsion droplets, which in turn depended on the viscosity of the solution. In addition, the agglomerates were nearly perfectly spherical in shape. In the QESD method, the quasi-emulsion droplets crystallized instantaneously from the droplet surface inward. The resultant agglomerates were dense, had great mechanical strength and showed excellent flowability due to their perfect spherical shape. On the other hand, the agglomerates produced by the SC method were conglomerates of primary crystals, and fine, needle-like crystals formed on their surface. As a result, these agglomerates had a large specific surface area, and they therefore showed greater solubility than the agglomerates prepared by the QESD method.

Uptake and processing of glycoproteins by isolated rat hepatic endothelial and Kupffer cells

Mannose-(Man) and N-acetylglucosamine- (GlcNAc)-terminated glycoproteins are cleared from blood by carbohydrate-specific receptors present on both hepatic endothelial and Kupffer cells. It is not known whether the same receptors are present on each cell type or the relative contributions to glycoprotein metabolism made by Kupffer and endothelial cells. Here we report experiments where data from glycoprotein metabolism by purified populations of isolated rat hepatic endothelial and Kupffer cells have been analyzed by mathematical modelling and parameter estimation. Kupffer cells had significantly higher binding rate constants (k'21) than endothelial cells for agalactoorosomucoid (AGOR) and hyaluronidase, but lower k12 ('off-rate') indicating that Kupffer cells had higher affinities for Man/GlcNAc-terminated glycoproteins than endothelial receptors. Furthermore, although endothelial cells had similar affinities (k'21 and k12) for AGOR and hyaluronidase, the 'off-rate' of Kupffer cells was significantly greater for AGOR than for hyaluronidase, indicating that Kupffer cell receptors have lower affinity for AGOR. Internalization and ligand catabolic rates also differed between the two cell types. The data indicate that Kupffer and endothelial cells appear to have different Man/GlcNAc receptors and that the destination of a glycoprotein and its subsequent processing is determined by the structure of a glycoprotein's oligosaccharide.

Regurgitation of bile acids in rat liver under bile drainage: quantitative analysis by taurine or ursodeoxycholate loading test

In rats with an interrupted enterohepatic circulation of bile acids, levels of serum taurine-conjugated bile acids were increased significantly 3 h after intravenous administration of taurine. Similarly, serum taurine- or glycine-conjugated ursodeoxycholic acid (UDCA) was increased significantly 2 h after UDCA administration. These findings suggested that the administered taurine or UDCA was taken up into hepatocytes and utilized to form conjugated bile acids, which were thereafter regurgitated into the systemic circulation from the liver. The proportion of regurgitated taurine-conjugated bile acids relative to total serum bile acids measured by taurine loading (30%) almost coincided with that of regurgitated taurine- or glycine-conjugated UDCA relative to total serum bile acids measured by UDCA loading (31.6%). Thus, the present study showed conclusively that at least 30% of serum bile acids are derived from newly conjugated bile acids that are regurgitated from the liver in rats with bile fistula.

High concentration of free trimethyllysine in red blood cells

A high concentration of a basic unidentified amino compound was found in the blood of rats. It was isolated and identified as N epsilon,N epsilon,N epsilon-trimethyllysine by paper chromatography, thin-layer chromatography, high-performance liquid chromatography and amino acid analyzer. It was localized exclusively in red blood cells in the blood of rats. Free trimethyllysine was also determined in the liver, kidney, spleen, brain, muscle, heart and testis of rat. The concentration of free trimethyllysine in red blood cells was more than 10-times as high as that in the other tissues. This compound in red blood cells was found in different species of animals. The relationship between this free trimethyllysine and carnitine was discussed.

Purification and characterization of D-3-aminoisobutyrate-pyruvate aminotransferase from rat liver

D-3-Aminoisobutyrate-pyruvate aminotransferase (EC 2.6.1.40) was purified 1900-fold from rat liver extract. The purified enzyme showed a molecular mass of 180 kDa by gel-permeation HPLC analysis using a TSK gel G3000SW column. Reductive polyacrylamide gel electrophoresis in sodium dodecyl sulfate resulted in identification of a single band of approx. 50 kDa, indicating that the native enzyme is probably a tetrametric protein. The specific activity of the purified enzyme was 1.14 mumol/min per mg protein. D-3-Aminoisobutyrate and beta-alanine were good amino donors. The Km value for L-3-aminoisobutyrate was 100-times larger than that for the D-isomer. The apparent Km values for D-3-aminoisobutyrate and beta-alanine were 35 and 282 microM, respectively. Pyruvate, glyoxylate, oxalacetate, 2-oxo-n-valerate, and 2-oxo-n-butyrate were good amino acceptors. The apparent Km values for pyruvate and glyoxylate were 32 and 44 microM, respectively.

Increased accumulation of N-isopropyl-(I-123)p-iodoamphetamine in bronchial carcinoid tumor

Radionuclide imaging with N-isopropyl-(I-123)p-iodoamphetamine ([123I]IMP) was performed in a patient with recurrent bronchial carcinoid tumor. Increased accumulation of [123I]IMP was observed in the known lesions of the brain and neck on both tomographic and planar images. Scintigraphy also revealed unknown metastatic lesions of the paraaortic lymph nodes, which were later confirmed on x-ray CT. Iodine-123-IMP may have a potential role in evaluating carcinoid tumors.

Unusual trihydroxy bile acids in the urine of patients treated with chenodeoxycholate, ursodeoxycholate or rifampicin and those with cirrhosis

Urinary bile acids from 20 patients treated with chenodeoxycholate, 18 treated with ursodeoxycholate, 15 treated with rifampicin and 8 patients with advanced cirrhosis were analyzed by gas-liquid chromatography and gas-liquid chromatography-mass spectrometry. Occurrence rates and amounts of three so-called unusual trihydroxy bile acids, hyocholate, ursocholate and omega-muricholate, were increased in patients treated with chenodeoxycholate, ursodeoxycholate or rifampicin and decreased in cirrhotic patients as compared with those in untreated healthy adults. These data suggest that chenodeoxycholate and ursodeoxycholate are hydroxylated to produce unusual trihydroxy bile acids in bile acid-loaded humans and that this metabolism may be related to the induction of hepatic microsomal enzymes by rifampicin. In contrast, the hydroxylation of chenodeoxycholate and ursodeoxycholate may be impaired by severe hepatic damage. Because the urine is a secretory pathway for internal bile acids, the occurrence of unusual trihydroxy bile acids in the urine may be used as an indicator of hepatic ability to metabolize "hydrophobic" dihydroxy bile acids to their secretory forms.

[MR imaging for lung cancer in evaluating local invasion; referring to CT and surgical-histological basis]

The diagnostic potentiality of MR imaging for lung cancer was researched in 17 patients in evaluating local invasions based on surgical-histological evidence. Comparative reviewing with CT was also performed. MR imaging appeared to have an ability unique to portray malignant invasions somewhere such as in the hili or apices. On the other hand, there were also some diagnostic limitations of MR imaging in delineating the localized invasive changes. On the way of working up lung cancer, CT still may stand at the first choice as a radiographic staging procedure which provides the more detailed anatomic-pathologic informations. We consider that MR imaging is mandatory when CT and/or other modalities could'not obtain efficient results.

[CT of hypersensitivity pneumonitis]

High resolution computed tomography (CT) was applied to seven patients with hypersensitivity pneumonitis clinically confirmed. The CT findings include; (1) granular pattern with acino-centric distribution, (2) increase in density of haziness in the lung fields, (3) multiform high density areas, and (4) "subpleural curvilinear shadow" localized posteriorly. Of these findings, which severally varied degree during clinical course, the haziness showed the most remarkable fluctuation. It was especially of interest that the relapsed haziness distributed quite in the same regions. High resolution CT may be an effective adjuvant tool for hypersensitivity pneumonitis when applied to the opportune evaluation through the clinical course.

Sphingolipid hydrolase activator proteins and their precursors

Activator proteins for sphingolipid hydrolases (saposins) are small acidic, heat-stable glycoproteins that stimulate the hydrolysis of sphingolipids by lysosomal enzymes. The molecular mass of each stimulator is about 10 kDa, but glycosylated forms of higher mass exist too. The distribution and developmental changes in two saposins and their precursor proteins were studied with the aid of monospecific antibodies against saposin-B and saposin-C. They show a wide distribution in rat organs and forms intermediate between saposin and prosaposin (the precursor protein containing four different saposin units) could be seen. The amount of saposin and the degree of processing from prosaposin are quite different in different tissues. The saposins are the dominant forms in spleen, lung, liver, and kidney, while skeletal muscle, heart, and brain contain mainly precursor forms. In human blood, leukocytes contain mainly saposin, while plasma contains mainly precursor forms and platelets show many forms. Their subcellular distribution was studied using rat liver. The saposins of approximately 20 kDa are dominant in the light mitochondrial, mitochondrial, and microsomal fractions, following the distribution of the activity of a lysosomal marker enzyme. The nuclear fraction exhibits bands corresponding to non-glycosylated saposin. The soluble fraction contained much precursor forms. A developmental study of rat brain showed that the concentration of saposin precursors increased with age.

Heat-stable protein that stimulates acid alpha-glucosidase

A hot-water extract of bovine spleen and guinea pig liver exhibited the ability to enhance acid alpha-glucosidase activity, with methylumbelliferyl alpha-glucoside, glycogen or maltose as substrate. The level of activator required for maximal stabilization was similar for all three substrates, indicating direct action on the enzyme rather than on substrate. The stimulator was partially purified by chromatography with gel-permeation (apparent Mr 20,000-24,000), ion-exchange and C4 reverse-phase columns. It was retained by a narrow-pore dialysis tubing and destroyed by treatment with Pronase, and is presumably a protein. The stimulating protein protected the enzyme against denaturation by heat or incubation with a buffer of high ionic strength in the absence of substrate. RNA inhibited the enzyme, and the activator protein was able to counteract the effect. Activating material was found in a variety of mouse and rat tissues, as well as human urine.

Fluorometric assay of nicotinamide methyltransferase with a new substrate, 4-methylnicotinamide

A fluorometric method for the assay of nicotinamide methyltransferase has been established using rat liver 9000 x g supernatant fluid as a model enzyme preparation. 1,4-Dimethylnicotinamide formed enzymatically from a new substrate, 4-methylnicotinamide, is quantified by means of its fluorescence reaction with 4-methoxybenzaldehyde in aqueous alkali. The lower limit of determination of 1,4-dimethylnicotinamide is 100 pmol in the enzymatic reaction mixture. The apparent Km values for 4-methylnicotinamide and for nicotinamide, which is a known substrate for this enzyme, were 0.19 and 0.13 mM, respectively, whereas the relative activity of 4-methylnicotinamide as a methyl acceptor was about 1.5 times the value of nicotinamide.

Water, fixed charge density, protein contents, and lysine incorporation into protein in chymopapain-digested intervertebral disc of rabbit

Chymopapain (Discase) was injected at a dose of 0.125 nanokatal unit into the intervertebral discs of rabbits, and sequential changes in the metabolism of water, proteoglycan, collagen, and noncollagenous protein were investigated separately in the nucleus pulposus, anterior, and posterior anulus fibrosus. One week after chymopapain injection, the water and proteoglycan content was lower in all of the fractionated tissues of the anterior and posterior anulus and nucleus pulposus of the discs than in the control discs. In the anterior and posterior anulus, the proteoglycan content recovered after 12 weeks, but there was no recovery in the nucleus pulposus. The collagen content continued to increase up to the 12th week in the nucleus pulposus, while the noncollagenous protein content decreased in all tissue fractions after 1 week. In the anterior and posterior anulus, the content of noncollagenous protein recovered after 3 to 6 weeks, but there was no recovery in the nucleus pulposus. The lysine incorporation in collagen and noncollagenous protein was inhibited in all tissue fractions after 12 weeks, suggesting a decrease in synthetic activity. The intradiscal pressure calculated from proteoglycan hydration at 1 to 6 weeks after chymopapain injection showed a marked decrease to 0.8 to 0.9 atm, but it recovered to 1.6 atm after 12 weeks.

High performance liquid chromatography determination of cyanide in urine by pre-column fluorescence derivatization

A method for the determination of cyanide in human urine has been developed. The method is based on the reaction of cyanide with 2,3-naphthalenedialdehyde and taurine to give a fluorescent product for reversed-phase HPLC separation and fluorometric detection. After centrifugation followed by dilution of urine samples, the specimens could be analysed directly by this method. The recovery of cyanide added to urine at concentration levels of 50-1000 pmol/mL was 85-96%. The detection limit of cyanide was 30 pmol/mL in urine. The method was successfully applied to the analysis of urine from smokers and nonsmokers. The mean concentrations of cyanide were found to be 215 pmol/mL for the former and 84 pmol/mL for the latter.

[DS-bronchial arteriography; demonstration of metastasized lymphnodes of lung cancer--with special reference to the primary effect in BAI]

We analysed the 44 DS-Bronchial arteriograms (DSBAG) of lung cancer with an attention to the demonstration of metastasized mediastinal lymphnodes. The stain of lymphnode is well demonstrated in the pericarinal region, such as station #7, #R4 along the course of bronchial arteries. The swollen nodes with stains on DSBAG show the good reduction rates (37.5%) after BAI that is analogous to the primary lesion (38.9%), in contrast to the nodes without stains (24.5%). DSBAG with excellent contrast resolution contributes to the BAI as verifying the infused area.

Chlamydospore formation by Paracoccidioides brasiliensis mycelial form

To investigate the role of some adverse environmental conditions in chlamydospore formation by the mycelial form of P. brasiliensis, we cultured four P. brasiliensis isolates (18, Bt4, 1183, Pb9) at 25 degrees C within solid agar medium either rich or poor in nutrients. Isolates 18 and 1183 were also cultured under anaerobiosis in a nitrogen atmosphere. Isolate 18 produced great number of terminal and intercalary chlamydospore after 7-10 days of culture in a medium poor in nutrients (2% agar with 0.1% dextrose and polypepton). The three other isolates also produced chlamydospores under the same conditions, but in lower numbers. Chlamydospore production by isolate 18 was abolished when the fungus was cultured in two agar media rich in nutrients (brain heart infusion and potato dextrose agar). Anaerobic incubation of isolate 18 under an atmosphere of N2 showed small mycelial outgrowth with numerous chlamydospores. At the electron microscopical level, the chlamydospores showed one or various nuclei and numerous mitochondria, indicating great potential for further development. Accordingly, chlamydospores produced multiple budding after only 24 h incubation at 35 degrees C. The results demonstrate that under adverse environmental conditions P. brasiliensis mycelial form produces chlamydospores within a short period of time.

[Interventional DSA in lung cancer--bronchial artery infusion]

Bronchial artery infusion (BAI) has been looked to as an important adjunct for controlling lung cancer. However, there are some anatomic facts to meet in performing angiography: multiplicity of the bronchial artery with wide variation of ramification pattern. To deal with these problems, since 1984, we have been working with DSA apparatus (Siemens: ANGIOTRON) for intervention in 162 cases of lung cancer. Because of higher contrast resolution, subtracted dynamic image and realtime replay on CRT, DSA allows (1) bronchial artery mapping on aortography, (2) prompt verification of the areas to be or not to be infused by anticancer drugs, and (3) tumor stain not only in the primary lesion but also metastasized lymph nodes or mediastinal invasion. DSA aortography evaluated the right-sided bronchial artery more frequently (90.1%) than the left-sided (46.3%). Tumor location made feeding vessels more remarkable on DSA: 96.0% in the right and 68.9% in the left. The overall accuracy of BAI basically depends on the result of DSA measuring 91.9% (149 of 162 cases). The effect of BAI combined with radiation therapy, for each histologic category, preliminarily estimated in two groups: one with two drugs and another with CDDP. Small cell carcinoma with "two drugs" and squamous cell carcinoma with CDDP seem to show statistical predominance in the period of 50% tumor size reduction.

[High resolution computed tomography of diffuse interstitial pneumonia during treatment]

HRCT was carried out in twenty patients with diffuse interstitial pneumonia: 13 cases of IIP, 3 of BOOP, 2 of drug-induced pneumonia, 1 of rheumatoid lung and acute interstitial pneumonia of unknown origin. With special attention to inflammatory activity, the patients underwent HRCT periodically during the treatment. Correlative investigation between HRCT image and grade of accumulation in 67Ga scintigraphy was also performed. Response to steroid therapy was clearly reflected on HRCT image, that was shown as decreasing pulmonary density or thinning of honeycomb wall. HRCT is considered to be useful in assessing the activity of diffuse interstitial pneumonia.