Prognostic factors in supratentorial WHO grade II astrocytoma in adults

The records of 33 adult patients with supratentorial World Health Organization grade II astrocytoma (A-II) treated between January 1980 and April 1997 at our hospitals were retrospectively reviewed. All tumours were surgically resected or biopsied and their MIB-1 labelling indices (LIs) were less than 1.5%. The median time to tumour progression after the initial surgery was 60 months, and the 5- and 10-year tumour progression-free rates were 53 and 39%, respectively. The median survival time was 107 months, and the 5- and 10-year survival rates were 66 and 43%, respectively. The major cause of death was tumour recurrence with malignant transformation, comprising 93% of all deaths due to unrestrained tumour growth. In a univariate analysis for survival rate by log-rank test, age (< 60 years), Karnofsky Performance Scale score (90-100%), tumour location (except for the basal ganglia), and extent of surgery (more than biopsy) were revealed to be significant positive prognostic factors. A Cox proportional hazard multivariate regression analysis confirmed that the age was the only independent, significant positive prognostic factor in this series. The survival time after the initial surgery in patients without radiotherapy tended to be prolonged compared with those of the patients with radiotherapy. Of the 26 patients who received radiotherapy, however, the survival time after the initial surgery in the nine patients with intraoperative radiotherapy was significantly prolonged compared with the 17 patients who received sole external beam radiotherapy. Gender, symptoms, histology, p53 LI, enhancement on CT/MRI, cyst, calcification and chemotherapy were not shown to be significant prognostic factors. The optimal management strategy for A-II is expected to be established by clarification of the natural history with cytological and molecular biological analyses of the biological features of this disease.

Prenatal diagnosis of fetal urogenital abnormalities with oligohydramnios by magnetic resonance imaging using turbo spin echo technique

Turbo spin echo technique is a sequence that enables T2 weighted magnetic resonance (MR) images to be obtained in a few seconds. The purpose of this study is to evaluate the usefulness of this sequence in the prenatal diagnosis of fetal urogenital abnormalities associated with oligohydramnios, which make the ultrasound examination inconclusive. Two fetuses suspected of having prune belly syndrome and polycystic kidney on ultrasound examination were studied by MR imaging using turbo-spin echo method in utero. The images were compared with prenatal ultrasonography or post-mortem findings. In both fetuses, abnormalities were diagnosed correctly. This sequence is useful because it provides images of diagnostic quality in a very short scanning time.

Defect in synaptic vesicle precursor transport and neuronal cell death in KIF1A motor protein-deficient mice

The nerve axon is a good model system for studying the molecular mechanism of organelle transport in cells. Recently, the new kinesin superfamily proteins (KIFs) have been identified as candidate motor proteins involved in organelle transport. Among them KIF1A, a murine homologue of unc-104 gene of Caenorhabditis elegans, is a unique monomeric neuron- specific microtubule plus end-directed motor and has been proposed as a transporter of synaptic vesicle precursors (Okada, Y., H. Yamazaki, Y. Sekine-Aizawa, and N. Hirokawa. 1995. Cell. 81:769-780). To elucidate the function of KIF1A in vivo, we disrupted the KIF1A gene in mice. KIF1A mutants died mostly within a day after birth showing motor and sensory disturbances. In the nervous systems of these mutants, the transport of synaptic vesicle precursors showed a specific and significant decrease. Consequently, synaptic vesicle density decreased dramatically, and clusters of clear small vesicles accumulated in the cell bodies. Furthermore, marked neuronal degeneration and death occurred both in KIF1A mutant mice and in cultures of mutant neurons. The neuronal death in cultures was blocked by coculture with wild-type neurons or exposure to a low concentration of glutamate. These results in cultures suggested that the mutant neurons might not sufficiently receive afferent stimulation, such as neuronal contacts or neurotransmission, resulting in cell death. Thus, our results demonstrate that KIF1A transports a synaptic vesicle precursor and that KIF1A-mediated axonal transport plays a critical role in viability, maintenance, and function of neurons, particularly mature neurons.

Primary pleomorphic adenoma in posterior cranial fossa

A 35-year-old woman had an intradural tumor in the posterior fossa adjacent to the posterior wall of the left pyramidal bone, which was totally removed and histologically diagnosed as a pleomorphic adenoma. Follow-up examination for 2 years showed no recurrence of the tumor. There was no primary lesion in any other gland of the body, and therefore there is no alternative but to conclude a "migration" of some gland cells. The pathogenesis of this tumor remains unclassified.

The mechanisms of nickel uptake by rat primary hepatocyte cultures: role of calcium channels

The present study was designed to clarify the mechanism of nickel (Ni) uptake in primary cultures of rat hepatocytes. Exposure of the hepatocytes to Ni (2-50 microM; as NiCl2) for up to 6 h was not cytotoxic, as assessed by the tetrazolium-based dye (MTT) assay. Hepatocytes were treated with 10 microM NiCl2 in the absence or presence of calcium (Ca) and magnesium (Mg) (1 mM). Ni uptake was increased by 19% in medium lacking Mg or Ca and was increased by 37% in Ca- and Mg-free medium. The role of Ca channels on Ni uptake by the hepatocytes was investigated. Pretreatment with nicardipine or verapamil (200 microM), potent inhibitors of Ca channels, decreased Ni uptake by 20%. This effect was only observed when the cells were incubated in the absence of Ca. Pretreatment with vasopressin (100 nM), a well-known Ca channel agonist, significantly increased Ni uptake by the hepatocytes (24%). To determine the involvement of carrier-mediated processes on Ni uptake, the effect of temperature was also investigated. At 4 degrees C the Ni uptake was decreased by 20% compared to uptake at 37 degrees C. These results indicate that Ni uptake by the hepatocytes occurs, at least in part, through the Ca channel transport processes. Further study will be required to assess what other mechanisms are involved.

Effect on prognosis of bone marrow infiltration detected by magnetic resonance imaging in small cell lung cancer

The staging system of limited disease (LD) and extensive disease (ED) is widely used and has been shown to provide useful prognostic information in cases of small cell lung cancer (SCLC). However, accurate examinations are necessary for correct staging. In this report, we evaluated the clinical usefulness of magnetic resonance imaging (MRI) of bone marrow in SCLC. 37 patients with LD by standard staging and 41 with ED were examined with bone marrow MRI. Results of bone marrow MRI did not influence the choice of treatment in patients with LD. For subsequent analysis, patients with LD were divided into two groups: patients in whom bone marrow infiltration was detected with MRI (MRI-positive LD group) and those in whom it was not (MRI-negative LD group). Focal or diffuse metastases to bone marrow were detected with MRI in 46% (36/78) of all patients and 35% (13/37) of LD patients. The response rates to treatment in patients with MRI-positive LD were lower than those in patients with MRI-negative LD (P = 0.006). The survival of patients with MRI-positive LD was worse than that of MRI-negative LD (generalised Wilcoxon test: P = 0.0157), and closer to that of ED. Multivariate analyses using a Cox model that included the result of bone marrow MRI, performance status, chemotherapy regimen, radiotherapy and serum lactose dehydrogenase (LDH) level showed that the result of bone marrow MRI remained a prognostic factor in SCLC patients with limited disease. Bone marrow examination with MRI is useful for better staging of SCLC. According to our analysis of response rates and survival, MRI-positive LD should be considered a type of ED.

Preventive effects of saponins from puerariae radix (the root of Pueraria lobata Ohwi) on in vitro immunological injury of rat primary hepatocyte cultures

The preventive effects of saponins from Puerariae Radix toward in vitro immunological liver injury using an antiserum against the rat liver plasma membranes on primary cultured rat hepatocytes were studied. Crude saponin from Puerariae Radix inhibited the elevation of alanine aminotransferase (ALT) activity at the dose of 90 micrograms/ml. The inhibition was stronger than that of glycyrrhizin, which was a positive control drug. The representative saponins in this drug, soyasaponin I and kudzusaponin SA3, were also more effective than glycyrrhizin, although their effects were weaker than that of crude saponin at the lower doses (90, 200 micrograms/ml). At 500 micrograms/ml, kudzusaponin SA3 showed antihepatotoxic activity equal to that of crude saponin.

Analyses of APG13 gene involved in autophagy in yeast, Saccharomyces cerevisiae

We have isolated 14 apg mutants defective in autophagy in yeast Saccharomyces cerevisiae (Tsukada and Ohsumi, 1993). Among them, APG1 encodes a novel Ser/Thr protein kinase whose kinase activity is essential for autophagy. In the course of searching for genes that genetically interact with APG1, we found that overexpression of APG1 under control of the GAL1 promoter suppressed the autophagy-defective phenotype of apg13-1 mutant. Cloning and sequencing analysis showed that the APG13 gene encodes a novel hydrophilic protein of 738 amino acid residues. APG13 gene is constitutively expressed bot not starvation-inducible. Though dispensable for cell proliferation, APG13 is important for maintenance of cell viability under starvation conditions. apg13 disruptants were defective in autophagy like apg13-1 mutants. Morphological and biochemical investigation showed that a defect in autophagy of delta apg13 was also suppressed by APG1 overexpression. These results imply genetic interaction between APG1 and APG13.

Clinical analysis of recurrent subarachnoid hemorrhage after neck clipping surgery

The clinical features of recurrent subarachnoid hemorrhage (SAH) after neck clipping surgery were investigated in a series of 1,436 consecutive patients treated between 1980 and 1994, and seven patients treated prior to 1980. Recurrent SAH occurred within 1 month in seven patients and between 1.5 and 20 years in 20 patients (mean interval 9.2 years) from the first surgery. The patients were aged from 31 to 76 years (mean 49.8 years) at the first SAH. There were 19 females and eight males. Recurrent SAH occurred at the same site as the prior aneurysms in 12 cases, at an infundibular dilatation in three cases, de novo aneurysms in nine cases, untreated multiple aneurysms in two cases, and unknown in one case. The main causes for early recurrent SAH were incomplete clipping or untreated multiple aneurysms, whereas late recurrent SAH was due to de novo aneurysms, untreated multiple aneurysms, or regrowth aneurysm at the prior site. The outcomes of late recurrent SAH were good in eight cases, moderate disability in two, severe disability in three, and dead in seven, whereas most cases of early recurrent SAH resulted in poor outcome. Immediate postoperative angiography is desirable in cases with incomplete clipping, because early recurrent SAH resulted in poor outcomes. De novo or regrowth aneurysms caused late recurrent SAH, so follow-up angiography is strongly recommended for young patients, even if complete clipping was achieved.

Comparative effects of disulfiram and diethyldithiocarbamate against testicular toxicity in rats caused by acute exposure to cadmium

Disulfiram (DSF) and diethyldithiocarbamate (DED) were compared for their protective effects against the testicular toxicity induced by acute exposure to cadmium (Cd) in rats. Rats were injected subcutaneously with CdCl2 126.7 mumol (3 mg) Cd/kgl, and 30 min later they were injected intraperitoneally with DSF (0.05-0.5 mmol/kg) or DED (0.1-1 mmol/kg). The treatment with DSF at dose levels of 0.1-0.5 mmol/kg prevented the increases in testicular lipid peroxidation and calcium (Ca) concentrations and the decreases in testicular weight that were observed at 7 d after Cd injection. DED at dosage levels of 0.2-1 mmol/kg likewise reduced Cd-induced testicular toxicity. An increase in testicular iron (Fe) concentrations at 7 d and sterility at 59 d after Cd injection were almost completely blocked by treatment with DSF or DED at the highest doses, but lower doses of DSF or DED were ineffective. These results indicated that DSF, which is metabolized to DED, had a protective effect against Cd-induced testicular toxicity nearly equivalent to DED at approximately one-half the dose.

Effects of dithiocarbamates on toxicity of cadmium in rat primary hepatocyte cultures

The protective effects of N-benzyl-D-glucamine dithiocarbamate (BGD) and N-p-hydroxymethylbenzyl-D-glucamine dithiocarbamate (HBGD) on the toxicity of Cd in the rat primary hepatocyte cultures were studied. Cytotoxicity was assessed by measuring cell viability, extra cellular lactic dehydrogenase (LDH) activity, and intracellular lipid peroxidation and active oxygen species. Primary hepatocyte cultures were treated with 109CdCl2 (5, 10 or 50 microM Cd and 1.7 KBq of 109Cd/well) for 30 min or 4 h. BGD or HBGD was added to the culture medium to make the final concentration of 100 microM and incubated for 4.5 h in 30 min Cd exposure or 1 h in 4 h Cd exposure. Decreases in the hepatocyte viability caused by all Cd exposure concentrations were significantly prevented by treatment with BGD or HBGD. The treatment with the chelating agents for 4.5 h after Cd exposure for 30 min significantly prevented increases in extracellular LDH activity. Increases in the lipid peroxidation in hepatocytes exposed to Cd for 30 min or 4 h were prevented significantly by treatment with BGD or HBGD for 4.5 h or 1 h, respectively. Moreover, the increases in the level of active oxygen species caused by Cd exposure for 30 min were significantly prevented by treatment with the chelating agents for 1.5 h. These findings suggest that BGD and HBGD protect against the cytotoxicity of Cd in rat primary hepatocyte cultures and that the protective effects of chelating agents presumably result from a decrease in the Cd level, the effective sequestration of the reactive Cd ion, and the direct preventive effect on the active oxygen species in the hepatocytes.

Preferential localization of annexin V to the axon terminal

To examine the participation of annexin V, a member of Ca(2+)-dependent phospholipid-binding proteins, in the process of synaptic vesicle exocytosis, rat central nervous tissue was analysed using biochemical and morphological techniques. By both fluorescence and confocal laser scanning microscopy, immunoreactivity for annexin V was predominantly localized around neuronal somata and dendrites, and the reactivity was mostly co-labeled with that for synaptophysin. The annexin V immunoreactivity was also detectable, but less intensely, in neuronal perikarya, glial cells and endothelial cells. Both immunoblot and immunoelectron microscopic analyses with intact tissues, synaptosomes and purified synaptic vesicles showed that annexin V was expressed in neurons, preferentially concentrated in axon terminals and associated with synaptic vesicles. Purified synaptic vesicles were relatively homogeneously distributed in the medium where Ca2+ was removed and thus the amount of annexin V was reduced drastically. The vesicles tended to be clustered in the fraction where endogenous annexin V is maintained, and the clusters were more conspicuous when purified human annexin V was added. Synaptic vesicles forming the clusters were not directly fused with each other but separated by a 10-15 nm gap that corresponded well with the size of single annexin V molecules. In axon terminals, globular structures 12-13 nm in diameter, similar in dimension to annexin V molecules, were distinctly found to be attached to the cytoplasmic surface of both vesicle membranes when the two vesicles were close to each other. These results suggest that annexin V belongs to the group of synaptic vesicle-associated proteins. Although its localization and significance in non-neuronal cells were not analysed here, at least in the axon terminal annexin V may participate in the cluster formation of synaptic vesicles by linking with the cytoplasmic surface of the vesicles in a Ca(2+)-dependent manner.

Mechanism of mobilization of cadmium by dithiocarbamates in rat primary hepatocyte cultures

The mechanism of mobilization of cadmium (Cd) by N-benzyl-D-glucamine dithiocarbamate (BGD) and N-p-hydroxymethylbenzyl-D-glucamine dithiocarbamate (HBGD) in rat primary hepatocyte cultures was studied. Probenecid pretreatment increased Cd efflux from the hepatocytes by BGD, but did not affect Cd efflux by HBGD. p-Aminohippurate treatment had no effect on Cd efflux by the chelating agents. These results suggest that an enhancing effect of probenecid on the BGD-induced Cd mobilization is due to its inhibitory effect on the glucuronidation of BGD and not its specific action on BGD transport. Verapamil and nicardipine had no effect on the chelating agent-induced Cd mobilization. Phlorizin did not affect Cd efflux by BGD or HBGD. Phloretin and cytochalasin B inhibited Cd efflux by the chelating agents. These results seem to be evidence that BGD and HBGD may be transported by a facilitated diffusion system in the hepatocytes.

Comparative effects of chelating agents on pulmonary toxicity of systemic nickel in mice

N-Benzyl-D-glucaminedithiocarbamate (BGD), diethyldithiocarbamate (DDTC), dihydroxyethyldithiocarbamate (DHED), trans-1,2-cyclohexanediamine N,N,N',N'-tetraacetic acid (CDTA) and meso-2,3-dimercaptosuccinic acid (DMSA) were studied for their protective effects against the pulmonary toxicity in mice induced by acute exposure to nickel. Nickel injection increased lipid peroxidation, lactate dehydrogenase (LDH) activity and the concentrations of protein, phospholipids (PL) and essential metals such as Ca, Fe and Zn and decreased the reduced glutathione (GSH) concentration and alkaline phosphatase (ALP) activity in the lungs. At 30 min after Ni treatment, DMSA, BGD and DDTC effectively depressed Ni concentration in the lungs. At 24 h after Ni treatment, DMSA and BGD were effective in mobilizing Ni from the lungs. Both DMSA and BGD significantly prevented increases in lipid peroxidation and in the concentrations of PL, Ca, Fe and Zn, and decreases in GSH concentration and ALP activity in the lungs of mice caused by Ni injection. Treatment with DMSA or BGD was more effective than that with other chelating agents in decreasing the pulmonary Ni concentration and preventing other changes caused by acute exposure to Ni, resulting in effective protection against Ni-induced pulmonary damage.

Active transport of photoactivated tubulin molecules in growing axons revealed by a new electron microscopic analysis

To determine whether tubulin molecules transported in axons are polymers or oligomers, we carried out electron microscopic analysis of the movement of the tubulin molecules after photoactivation. Although previous optical microscopic analyses after photobleaching or photoactivation had suggested that most of the axonal microtubules were stationary, they were not sufficiently sensitive to allow detection of actively transported tubulin molecules which were expected to be only a small fraction of total tubulin molecules in axons. In addition, some recent studies using indirect approaches suggested active polymer transport as a mechanism for tubulin transport (Baas, P.W., F.J. Ahmad. 1993. J. Cell Biol. 120:1427-1437; Yu, W., V.E. Centonze, F.J. Ahmad, and P.W. Bass, 1993, J. Cell Biol. 122:349-359; Ahmad, F.J., and P.W. Bass. 1995. J. Cell Sci. 108:2761-2769). So, whether transported tubulin molecules are polymers or not remain to be determined. To clear up this issue, we made fluorescent marks on the tubulin molecules in the axons using a photoactivation technique and performed electron microscopic immunocytochemistry using anti-fluorescein antibody. Using this new method we achieved high resolution and high sensitivity for detecting the transported tubulin molecules. In cells fixed after permeabilization, we found no translocated microtubules. In those fixed without permeabilization, in which oligomers and heterodimers in addition to polymers were preserved, we found much more label in the regions distal to the photoactivated regions than in the proximal regions. These data indicated that tubulin molecules are transported not as polymers but as heterodimers or oligomers by an active mechanism rather than by diffusion.

Pulmonary toxicity of systemic terbium chloride in mice

Terbium (Tb) is a rare earth metal that finds use in several emerging technologies. However, little is known about the biological effects of Tb. Thus, in this study the pulmonary toxicity of systemic Tb in mice was investigated. Mice were treated intravenously with a single dose of 20 or 200 mumol Tb/kg, as TbCly and killed at 3, 6, 12, 24, 48, or 72 h later. Administration of Tb at a dose of 200 mumol/kg increased pulmonary weight, lipid peroxidation, and protein content but decreased pulmonary glutathione content. Pulmonary gamma-glutamyl transpeptidase (gamma-GTP) activity was increased after Tb administration at a dose of 200 mumol/kg. Pulmonary alkaline phosphatase (ALP) activity was also increased after Tb administration at a dose of 200 mumol/kg. Investigation of the defense system against oxidative damage in the lung showed that superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities were all decreased after Tb administration at the higher dose. The concentrations of Tb, Ca, and P in lung was increased by the dose of 200 mumol/kg. These results suggest that pulmonary lipid peroxidation may be an early and sensitive consequence of Tb exposure and that SOD, CAT, and GSH-Px might be considered as potential modulators of Tb-induced lipid peroxidation. The mechanisms involved in Tb-induced pulmonary lipid peroxidation deserve further study.

Deep negative T waves and abnormal cardiac sympathetic image (123I-MIBG) after the Great Hanshin Earthquake of 1995

The authors report the increased incidence of patients with deep negative T waves without Q wave after the Great Hanshin Earthquake of 1995. Subjects underwent cardiac metaiodobenzyl guanidine (123I-MIBG) imaging, 201Tl scintigraphy, and coronary angiography. Among 2,756 inpatients of the preceding 5-year period, 33 (1.2%) showed the deep negative T waves, whereas 6 of 94 (6.4%; P < 0.001) showed it after the earthquake. Four of six patients had an episode of chest pain. Cardiac metaiodobenzyl guanidine imaging revealed the extent defects in all six patients despite a minimal change of 201Tl image. In addition, cardiac metaiodobenzyl guanidine imaging washout rate was hastened not only in the defect area but also in the nondefect area, which suggested augmented sympathetic activation. Natural disasters can affect the frequency of deep negative T waves, which relate abnormal cardiac sympathetic imaging.

Effect of nickel on enzymatic activities in the mouse pancreas

The effect of nickel (Ni) on the enzymatic activities in the pancreas of mice was studied. Administration of Ni at the dose of 5 mg Ni/kg increased the trypsin activity and decreased carboxypeptidase A activity, but did not affect the activities of chymotrypsin, carboxypeptidase B, amylase, and lipase. Increases in Ca concentrations in the pancreas after Ni administration were observed. In the pancreatic slice experiments, Ni treatment showed a slight decrease in trypsin activity and remarkable decreases in chymotrypsin and carboxypeptidase A activities, and Ca treatment induced increases in the activities of trypsin and carboxypeptidase A. These results suggest that the increase in trypsin activity in the pancreas after Ni administration results from the activation of trypsinogen by the Ca ion and that the decrease in carboxypeptidase A activity is based on the inhibitory effect of Ni on carboxypeptidase A activity.

Effects of lanthanide ions on the binding ability of annexin V to phospholipid vesicle

The effects of lanthanide ions (Ln(3+)), La(3+), Ce(3+), Gd(3+), and Tb(3+), on the binding ability of annexin V to phospholipid vesicle were studied, and compared with that of Ca(2+). The energy transfer following excitation at 278 nm was accompanied by a small decrease (about 3%) in the fluorescence signal (310-315 nm) of the aromatic amino acid residues, followed by strong re-emission of annexin V-bound Tb(3+) at 547 nm. The results of the titration of Tb(3+)-protein interactions using the rate dialysis method suggest that there are two high affinity metal binding sites on annexin V, to which Tb(3+) binds with an average dissociation constant, Kd, of about 2.11 x 10(-7) M. The Ln(3+) seemed to assist the anticoagulant action of annexin V because it binds more strongly to phospholipid than Ca(2+) does. Annexin V had the same ability to bind phospholipids in 10 mu M Ln(3+) as it did in 1 InM Ca(2+), showing that it binds to anionic phospholipids with Ln(3+) more strongly than it does with Ca(2+).

Selective stabilization of tau in axons and microtubule-associated protein 2C in cell bodies and dendrites contributes to polarized localization of cytoskeletal proteins in mature neurons

In mature neurons, tau is abundant in axons, whereas microtubule-associated protein 2 (MAP2) and MAP2C are specifically localized in dendrites. Known mechanisms involved in the compartmentalization of these cytoskeletal proteins include the differential localization of mRNA (MAP2 mRNA in dendrites, MAP2C mRNA in cell body, and Tau mRNA in proximal axon revealed by in situ hybridization) (Garner, C.C., R.P. Tucker, and A. Matus. 1988. Nature (Lond.). 336:674-677; Litman, P., J. Barg, L. Rindzooski, and I. Ginzburg. 1993. Neuron. 10:627-638), suppressed transit of MAP2 into axons (revealed by cDNA transfection into neurons) (Kanai, Y., and N. Hirokawa. 1995. Neuron. 14:421-432), and differential turnover of MAP2 in axons vs dendrites (Okabe, S., and N. Hirokawa. 1989. Proc. Natl. Acad. Sci. USA. 86:4127-4131). To investigate whether differential turnover of MAPs contributes to localization of other major MAPs in general, we microinjected biotinylated tau, MAP2C, or MAP2 into mature spinal cord neurons in culture (approximately 3 wk) and then analyzed their fates by antibiotin immunocytochemistry. Initially, each was detected in axons and dendrites, although tau persisted only in axons, whereas MAP2C and MAP2 were restricted to cell bodies and dendrites. Injected MAP2C and MAP2 bound to dendritic microtubules more firmly than to microtubules in axons, while injected tau bound to axonal microtubules more firmly than to microtubules in dendrites. Thus, beyond contributions from mRNA localization and selective axonal transport, compartmentalization of each of the three major MAPs occurs through local differential turnover.

Molecular cloning and characterization of murine IL-12 genes

IL-12 is a heterodimeric cytokine composed of two covalently linked chains, p40 and p35. p40 expression appears to be restricted to monocytes/macrophages and B cells and is highly regulated, while p35 is more ubiquitously and constitutively expressed. To investigate the mechanism involved in the regulation of IL-12 expression, we molecularly cloned and characterized the murine p40 and p35 genes. The p40 gene spans over 14 kb, consists of eight exons and seven introns, and was shown to be localized on chromosome 11A5-B2 by fluorescence in situ hybridization. A single major transcription initiation site was detected by primer extension analysis, and a TATA box was found at approximately 30 bp upstream from the transcription initiation site. The 5' flanking region preceding the transcription initiation site induced the enhanced expression of a promoterless reporter gene after LPS stimulation when transfected into a macrophage-like cell line. In contrast, the p35 gene spans over 8 kb and consists of seven exons and six introns on chromosome 6C, and multiple transcription initiation sites were detected. The 5' flanking region lacks canonical TATA and CAAT boxes at the appropriate position, but, instead, contains GC-rich sequences and constitutively mediated promoter activity when placed upstream of a promoterless reporter gene and transfected into a B cell lymphoma cell line. Thus, the characteristics of promoter regions of p40 and p35 genes are quite different, and this would account for the different regulations of p40 and p35 expression.

Molecular cloning and characterization of murine IL-12 genes

IL-12 is a heterodimeric cytokine composed of two covalently linked chains, p40 and p35. p40 expression appears to be restricted to monocytes/macrophages and B cells and is highly regulated, while p35 is more ubiquitously and constitutively expressed. To investigate the mechanism involved in the regulation of IL-12 expression, we molecularly cloned and characterized the murine p40 and p35 genes. The p40 gene spans over 14 kb, consists of eight exons and seven introns, and was shown to be localized on chromosome 11A5-B2 by fluorescence in situ hybridization. A single major transcription initiation site was detected by primer extension analysis, and a TATA box was found at approximately 30 bp upstream from the transcription initiation site. The 5' flanking region preceding the transcription initiation site induced the enhanced expression of a promoterless reporter gene after LPS stimulation when transfected into a macrophage-like cell line. In contrast, the p35 gene spans over 8 kb and consists of seven exons and six introns on chromosome 6C, and multiple transcription initiation sites were detected. The 5' flanking region lacks canonical TATA and CAAT boxes at the appropriate position, but, instead, contains GC-rich sequences and constitutively mediated promoter activity when placed upstream of a promoterless reporter gene and transfected into a B cell lymphoma cell line. Thus, the characteristics of promoter regions of p40 and p35 genes are quite different, and this would account for the different regulations of p40 and p35 expression.

Effects of chelating agents on testicular toxicity in mice caused by acute exposure to nickel

N-Benzyl-D-glucaminedithiocarbamate (BGD), diethyldithiocarbamate (DDTC), dihydroxyethyldithiocarbamate (DHED), trans-1,2-cyclohexanediamine N,N,N',N'-tetraacetic acid (CDTA), and meso-2,3-dimercaptosuccinic acid (DMSA) were studied for their protective effects against the testicular toxicity in mice induced by acute exposure to nickel (Ni). Mice were injected intraperitoneally with NiCl2 (5 mgNi/kg) and 30 min or 24 h later, they were injected intraperitoneally with chelating agents (400 mumol/kg). Ni injection increased lipid peroxidation and concentrations of Ca and Fe in the testes, liver, and kidney, and decreased the testicular weight and the fertility rate. At 30 min after Ni treatment, the chelating agents other than CDTA effectively depressed Ni concentration in the testes. At 24 h after Ni treatment, DMSA, BGD, and DDTC were effective in mobilizing Ni from the testes. DMSA, BGD, and CDTA significantly prevented the increase in the lipid peroxidation, the increase in the concentrations of Ca and Fe in the testes, liver, and kidney, and the decrease in the fertility rate caused by Ni injection. Treatment with DMSA or BGD was more effective than that with the others in decreasing the testicular Ni concentration, resulting in effective protection against Ni-induced testicular damage.

Protective effect of N-benzyl-D-glucamine dithiocarbamate against renal toxicity in rats during repeated cis-diamminedichloroplatinum administrations

The protective effects of N-benzyl-D-glucamine dithiocarbamate (BGD) against the renal toxicity caused by repeated injections of cis-diamminedichloroplatinum (DDP) were studied in rats. The rats were injected i.p. with BGD (2.0 mmol/kg) immediately after i.v. injection of DDP (20 mumol/kg), and after 10 and 20 days they received repeated treatments with the same doses of DDP and BGD. Treatment with BGD prevented nephrotoxicity after repeated DDP administrations. Repeated DDP injections increased lipid peroxidation in the kidney and decreased GSH concentration in the kidney at 5 days after the third injection of DDP. BGD treatment prevented the increase in lipid peroxidation and the decrease in the GSH concentration caused by repeated administration of DDP. The determination of activities of antioxidant enzymes in the kidney showed that catalase activity decreased after repeated DDP administrations and that superoxide dismutase activity tended to decrease. Changes in activities of these enzymes were prevented by BGD treatment. The platinum concentrations in kidney and liver were decreased by BGD treatment. These results indicate that BGD treatment prevents the accumulation of platinum in the kidney after repeated administrations of DDP, resulting in protection against the DDP-induced renal toxicity.

Effects of dithiocarbamates and cadmium on the enzymatic activities in liver, kidney and blood of mice

The effects of N-benzyl-D-glucamine dithiocarbamate (BGD), diethyldithiocarbamate (DDTC), and N-p-hydroxymethylbenzyl-D-glucamine dithiocarbamate (HBGD) on the enzymatic activities in mice were studied. The mice were given i.v. injections of these chelating agents (1 mmol/kg) and 3 h later the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyltranspeptidase (gamma-GTP), alkaline phosphatase (ALP), leucine aminopeptidase (LAP), and cholinesterase (ChE) in the liver, kidney, and blood were determined. These enzymatic activities were little changed by treatment with these chelating agents. Cadmium (Cd) administration markedly decreased the activities of AST and ALT in the liver and kidney and greatly increased these enzymatic activities in blood. The changes in the enzymatic activities by treatment with Cd were prevented by injection of BGD (1 mmol/kg). These results indicate that BGD, DDTC, and HBGD were not toxic to the liver or kidney of mice and that BGD treatment protected against the acute hepatic and renal toxicity induced by Cd.

Comparative effects of diethyldithiocarbamate and N-benzyl-D-glucamine dithiocarbamate on cis-diamminedichloroplatinum-induced toxicity in kidney and gastrointestinal tract in rats

Sodium diethyldithiocarbamate (DDTC) and sodium N-benzyl-D-glucamine dithiocarbamate (BGD) were compared for their protective effects against cis-diamminedichloroplatinum (DDP)-induced toxicity in kidney and gastrointestinal tract in rats. Rats were injected i.p. with the dithiocarbamates (2.0 mmol kg-1) immediately or 1 h after i.v. injection of DDP (20 mumol kg1). Treatment with BGD immediately or at 1 h after DDP injection effectively prevented the nephrotoxicity of DDP, but administration of DDTC immediately or 1 h after DDP afforded little protection. N-Benzyl-D-glucamine dithiocarbamte significantly reversed the reduction in maltase, sucrase and aminopeptidase activities of jejunal mucosa of rats treated with DDP, whereas treatment with DDTC concurrent with DDP could not reverse the reduction in disaccharidase activity following DDP injection. The platinum concentrations in liver and kidney were significantly decreased by treatment with BGD and DDTC. The treatment with DDTC at 1 h after DDP was more effective on the reduction of platinum concentrations in these tissues than that immediately after DDP. There was no difference between the renal and hepatic concentrations of platinum in two time intervals of BGD. The pharmacokinetic studies indicated that DDTC is more rapidly metabolized than BGD, resulting in larger total clearance and elimination rate constant values. These results reveal that the administration of BGD immediately and at 1 h after DDP can protect against the renal and gastrointestinal toxicities caused by DDP, whereas DDTC afforded little protection, and that the time interval between administration of DDP and DDTC greatly influences its protective effect on DDP-induced toxicity, indicating that the chelation therapy of BGD for DDP is superior to that of DDTC.

Ruptured dissecting aneurysm of the peripheral anterior cerebral artery--case report

A 27-year-old male presented with intracranial hemorrhage due to rupture of an idiopathic dissecting aneurysm in the A4 segment of the left anterior cerebral artery (ACA). This is a very rare location. He was successfully treated by resection of the aneurysm without neurological deficits. Surgical intervention is recommended for patients with intracranial hemorrhage due to ruptured dissecting aneurysm of the ACA to prevent rebleeding.

Tubulin dynamics in neuronal axons of living zebrafish embryos

The mechanism of cytoskeletal protein transport, especially the question of what kind of form the cytoskeletal proteins assume during transport in neurons in situ, has been an important, as yet unsettled issue. To clear up this matter, we adopted the embryonic zebrafish as a living animal model and applied the fluorescence recovery after photobleaching (FRAP) method. The zebrafish embryo is appropriate for this kind of study because of its transparency during the early developmental stage, allowing the observation of neurons that incorporate the microinjected fluorescent tubulin directly under fluorescence microscopy. FRAP revealed no movement of the bleached zone proximodistally, where fluorescence recovered gradually (recovery half-time, 44.2 +/- 11.2 min; n = 36), suggesting that the polymers are stationary but dynamic and that the true moving form could be small oligomers or heterodimers.

[Effect of the GH-PRL superfamily on circulating plasma insulin-like growth factor-1]

To elucidate the effects of growth hormone (GH), prolactin (PRL), and human placental lactogen (hPL) on the regulation of insulin-like growth factor (IGF-1), we compared plasma IGF-1 levels, the pattern of circulating IGF-1-IGF-binding protein complexes (IGF-1 complexes), and unsaturated binding protein (USBP) levels among 1) naturally growing Wistar rats at several developmental stages, 2) rats subcutaneously administered GH, and 3) hypophysectomized rats treated with each of the three hormones. We further evaluated the in vitro secretion of IGF-1 by primary cultured rat hepatocytes, following exposure to the hormones singly or in combination. Plasma IGF-1 and USBP levels were determined by radioimmunoassay and competitive radioassay, respectively. IGF-1 complexes were separated from plasma and culture medium by Sephadex G150 and HPLC gel-chromatography, respectively. The results were as follows. 1) In naturally growing rats, plasma IGF levels were low during fetal life and after birth until 28 days of age, and thereafter increased rapidly to reach an adult level by 35 days. At 35 days, the molecular distribution of IGF-1 switched from an infantile pattern (only 40Kd IGF-1 complex) to an adult form (IGF-1 complexes with both 40Kd and 150Kd proteins). In addition, 150Kd USBP became detectable after 28 days. 2) Administration of GH for 3 days to 13-day-old rats induced 150Kd USBP 9 days earlier than in controls, while plasma IGF-1 levels remained comparable throughout the period examined. 3) In the hypophysectomized rats, plasma IGF-1 levels decreased to approximately one fifth of those in untreated rats, accompanied by the disappearance of 150Kd USBP and 150Kd IGF-1 complex. However, when GH (but not PRL or hPL) was continuously administered for 72 hrs, plasma IGF-1 levels and the circulating profile of IGF-1 complexes were nearly restored to those in control rats. 4) Addition of GH (but not PRL) to the culture medium caused hepatocytes to secrete IGF-1, consisting of only the 40Kd IGF-1 complex. This effect was blocked by the simultaneous addition of hPL with GH. These findings indicate that, of the hormones analyzed, GH is the most important regulator of the plasma IGF-1 concentration and circulating complex forms during the developmental periods in rats, as is also thought to be the case in humans.

The utility of chelating agents as antidotes for nephrotoxicity of gold sodium thiomalate in adjuvant-arthritic rats

The effects of 2,3-dimercaptopropane sulphonate (DMPS) and N-(2-mercapto-2-methylpropanoyl)-L-cysteine (bucillamine) against the renal damage induced by gold sodium thiomalate (AuTM) in adjuvant-arthritic rats were studied. Arthritic rats induced by adjuvant using Mycobacterium butyricum were injected intraperitoneally with a chelating agent (0.6 mmol/kg) immediately after intramuscular injection of AuTM (0.066 mmol/kg) every other day for 21 days. Treatment with DMPS and bucillamine prevented increases in the urinary excretion of protein, aspartate aminotransferase, and glucose and blood urea nitrogen level after AuTM injection. AuTM prevented the increase in both adjuvant-injected and uninjected hind-feet volumes. The prevention of these inflamed lesions by AuTM was not affected by DMPS and bucillamine. These chelating agents decreased the gold concentration in the kidney and liver after AuTM administration, but did not affect the hepatic and renal concentrations of copper, zinc, iron, and calcium except the renal copper level after AuTM. These findings suggest that DMPS and bucillamine are very useful antidotes for gold toxicity.

Impaired cholinergic peripheral vasodilation and its relationship to hyperemic calf blood flow response and exercise intolerance in patients with chronic heart failure

This study examined the peripheral endothelium-dependent vasodilatory response to acetylcholine and the endothelium-independent vasodilatory response to nitroprusside in 19 patients with chronic heart failure and eight controls. These peripheral blood flow responses were compared with hyperemic calf blood flow changes after maximum leg exercise and 5-min femoral occlusion. The peripheral blood flow response to forearm intra-arterial infusion of acetylcholine and sodium nitroprusside, and reactive hyperemic calf blood flow changes were measured by plethysmography. All peripheral blood flow responses were significantly reduced in patients with chronic heart failure (P < 0.05). Reduction of acetylcholine-mediated changes in peripheral blood flow was correlated with exercise-induced calf blood flow response (r = 0.51, P < 0.05), but not with occlusion-induced calf blood flow response (r = 0.02, NS). Sodium nitroprusside-mediated changes were not correlated with any reactive hyperemic blood flow responses (exercise: r = 0.27, NS; occlusion: r = 0.11, NS). When the patients were divided into two subgroups based on the median exercise-induced calf blood flow change, the subgroup with the lower calf blood flow response showed a reduction in exercise capacity (anaerobic threshold: 11.8 +/- 0.6 vs. 14.6 +/- 1.0 ml/kg/min; P < 0.05). These findings suggest that endothelial dysfunction is related to a decrease in exercise-induced skeletal muscle blood flow and exercise capacity in patients with chronic heart failure.

Attenuated endothelium-dependent peripheral vasodilation and clinical characteristics in patients with chronic heart failure

Impairment of endothelium-dependent vasodilation has recently been reported in the peripheral vascular bed in patients with chronic heart failure. However, the clinical implications of this type of vascular dysfunction have yet to be elucidated. We have determined the degree of impairment of endothelium-dependent vasodilation as evaluated by acetylcholine-induced changes in forearm blood flow and compared this to various clinical parameters in 23 patients with chronic heart failure. Cumulative changes in forearm blood flow induced by acetylcholine (3.0 and 4.5 micrograms/min/dl tissue volume) were significantly lower in patients with chronic heart failure than in normal controls (10.1 +/- 8.0 ml/min/100 ml vs 20.4 +/- 11.7 ml/min/100 ml tissue volume; p < 0.01). In patients with heart failure, no significant relation was found between acetylcholine-induced changes in forearm blood flow and age, sex, duration of symptoms, duration of hospital stay, or resting hemodynamic parameters, although a significant positive correlation was observed with peak oxygen uptake (r = 0.53, p < 0.05) and ventilatory threshold (r = 0.42, p < 0.05). These observations suggest that the impairment of endothelium-dependent peripheral vasodilation may be one of the factors contributing to exercise intolerance in patients with chronic heart failure, probably resulting from its limiting effect on nutritive skeletal muscle blood flow during exercise.

Effect of angiotensin-converting enzyme inhibitors on endothelium-dependent peripheral vasodilation in patients with chronic heart failure

OBJECTIVES

This study was performed to determine whether acute inhibition of angiotensin-converting enzyme restores impaired endothelium-dependent vasorelaxation in patients with chronic heart failure.

BACKGROUND

Recent reports have demonstrated that endothelium-dependent vasodilation induced by cholinergic stimuli is attenuated in the peripheral vascular bed of patients with chronic heart failure.

METHODS

We examined the effects of local intraarterial infusion of enalaprilat (0.6 micrograms/min per 100 ml tissue volume) on responses initiated by acetylcholine or sodium nitroprusside in the forearm vascular bed in 8 normal subjects, 12 patients with mild heart failure (New York Heart Association functional classes I and II) and 10 patients with more advanced heart failure (functional classes III and IV). Forearm blood flow was measured by means of venous occlusion plethysmography.

RESULTS

Although enalaprilat alone did not affect basal forearm blood flow, it significantly augmented the increase in forearm blood flow induced by acetylcholine in normal subjects (p < 0.01) and in those with mild heart failure (p < 0.05). However, the effect was not found in patients with more advanced heart failure. Coinfusion of enalaprilat did not enhance sodium nitroprusside-induced vasodilation in any of the groups. To explore the mechanism of the inhibitor's effect, an additional 20 patients with mild heart failure (functional class II) were pretreated with a cyclooxygenase inhibitor, acetylsalicylic acid (n = 10) or an inhibitor of nitric oxide synthesis, NG-monomethyl-L-arginine (n = 10), followed by administration of acetylcholine with or without enalaprilat. Acetylsalicylic acid reduced the converting enzyme inhibitor's effect, whereas NG-monomethyl-L-arginine failed to block the augmentation of blood flow.

CONCLUSIONS

These results suggest that inhibition of angiotensin-converting enzyme potentiates endothelium-dependent vasodilation induced by cholinergic stimuli, presumably through modulation of prostaglandin metabolism, in the peripheral vasculature of patients with mild chronic heart failure.

Effects of chelating agents on tissue distribution and excretion of nickel in mice

N-Benzyl-D-glucaminedithiocarbamate (BGD), diethyldithiocarbamate (DDTC), di-hydroxyethyldithiocarbamate (DHED), trans-1,2-cyclohexanediamine N,N,N',N'-tetra-acetic acid (CDTA), and 2,3-dimercaptosuccinic acid (DMSA) were studied for their relative efficacies in the distribution and excretion of nickel in mice exposed to nickel. Mice were injected intraperitoneally with NiCl2 (5mgNi/kg) and 30 min or 24 hr later, they were injected intraperitoneally with chelating agents (400 mumol/kg). At 30 min after treatment with nickel, these chelating agents all significantly enhanced the fecal excretion of nickel, and DMSA significantly increased the urinary excretion of the metal. At 24 hr after nickel treatment, BGD, DDTC, and DHED significantly increased the fecal excretion of nickel and BGD was the most effective on the fecal excretion of nickel. CDTA and DMSA significantly enhanced the urinary excretion of the metal. At 30 min after nickel treatment, chelating agents other than CDTA effectively depressed nickel concentration in the kidney, lung, and testes. BGD, CDTA, and DMSA significantly reduced the nickel concentration in the liver. However, DDTC and DHED caused the redistribution of nickel to the brain. At 24 hr after nickel treatment, these chelating agents were effective in mobilizing nickel from the kidney, and chelating agents other than DHED were effective in mobilizing nickel from the liver, lung, and testes. These results indicate that the injection of BGD or DMSA at both 30 min and 24 hr after treatment with nickel can remove nickel from the body without redistribution of nickel to other tissues, such as brain, more effectively than DDTC, DHED, and CDTA. Furthermore, the pattern of excretion of nickel after treatment with the chelating agents was related to the partition coefficients of the nickel-chelating agent complexes.

Differential dynamics of neurofilament-H protein and neurofilament-L protein in neurons

Neurofilaments (NFs) are composed of triplet proteins, NF-H, NF-M, and NF-L. To understand the dynamics of NFs in vivo, we studied the dynamics of NF-H and compared them to those of NF-L, using the combination of microinjection technique and fluorescence recovery after photobleaching. In the case of NF-L protein, the bleached zone gradually restored its fluorescence intensity with a recovery half time of approximately 35 min. On the other hand, recovery of the bleached zone of NF-H was considerably faster, taking place in approximately 19 min. However, in both cases the bleached zone was stationary. Thus, it was suggested that NF-H is the dynamic component of the NF array and is interchangeable, but that it assembles with the other neurofilament triplet proteins in a more exchangeable way, implying that the location of NF-H is in the periphery of the core NF array mainly composed of NF-L subunits. Immunoelectron microscopy investigations of the incorporation sites of NF-H labeled with biotin compounds also revealed the lateral insertion of NF-H subunits into the preexisting NF array, taking after the pattern seen in the case of NF-L. In summary, our results demonstrate that the dynamics of the L and H subunit proteins in situ are quite different from each other, suggesting different and separated mechanisms or structural specialization underlying the behavior of the two proteins.

Symptomatic middle cerebral artery stenosis and occlusion: comparison of three-dimensional time-of-flight magnetic resonance angiography with conventional angiography

The usefulness of magnetic resonance (MR) angiography using the three-dimensional time-of-flight method for the characterization of symptomatic middle cerebral artery (MCA) occlusive lesions was evaluated in 10 patients with MCA occlusion and 10 with MCA stenosis. All lesions were symptomatic and documented by conventional angiography. There was no false-negative MR angiogram that failed to demonstrate the MCA occlusive lesion. MR angiography correctly evaluated the location of lesions and the difference between stenosis and occlusion. Stenosis appeared as a focal signal loss (< 1.0 cm) of the MCA at the site of stenosis, and occlusion as a complete signal loss of the MCA distal to the site of occlusion. However, MR angiography could not distinguish diffuse stenosis and one point stenosis demonstrated by conventional angiography. MR angiography is a useful noninvasive diagnostic method for evaluating occlusive lesions of the MCA in symptomatic patients.

Effect of terbium on protease activity in pancreas of mice

The effect of terbium (Tb) on the protease activity in pancreas of mice was studied. Administration of Tb at doses of 20 and 200 mumol/kg increased the activities of trypsin and carboxypeptidase A, but did not affect the activities of chymotrypsin and carboxypeptidase B. High Tb concentrations were found in the liver and spleen compared to the kidney and pancreas. Increases in Ca concentrations in the pancreas, kidney, and spleen after Tb administration were observed. The pancreatic slice experiments showed the increase in trypsin activity after Tb treatment and increases in trypsin and carboxypeptidase A after Ca treatment. Tb inhibited strongly the activities of authentic chymotrypsin and carboxypeptidase A. These results suggest that the increase in trypsin activity in the pancreas after Tb administration results from the activation of trypsinogen by Tb and Ca ions and that the increase in carboxypeptidase A activity is due to the activation of procarboxypeptidase A by trypsin and Ca ion, which increased after Tb administration.

[Qualitative evaluation of 123I-IMP SPECT using a rotating gamma camera in atherosclerotic large-artery disease]

PURPOSE Quantitative measurement of regional cerebral blood flow (rCBF) needs special equipment or invasive blood sampling. Therefore, with a popularly used rotating gamma camera, we tried to establish a convenient modality of qualitative evaluation of hemodynamics in patients with atherosclerotic large-artery disease, according to the distribution pattern of isotope-uptake on SPECT image. PATIENTS AND METHODS Forty-one patients with atherosclerotic large-artery disease [9 internal carotid artery (ICA) stenosis, 17 ICA occlusion, 8 middle cerebral artery (MCA) stenosis, and 7 MCA occlusion] and 32 control patients documented as having small cerebral infarction without atherosclerotic large-artery disease were investigated. Using the rotating gamma camera, they underwent 123I-IMP SPECT at baseline and after acetazolamide loading. According to the distribution pattern of low isotope-uptake, early images were classified into four types: Type I: no low uptake, Type II: low uptake in a single watershed, Type III: low uptake in two watersheds with or without a partial MCA territory, Type IV: low uptake in a whole MCA territory. RESULT In patients with large-artery disease, baseline images presented Type I in 12 cases, Type II in 16, Type III in 9, Type IV in 4, and loading images Type I in 3, Type II in 2, Type III in 8, Type IV in 28. Of 37 patients except for 4 belonging to Type IV at baseline, 32 (86.5%) had a more extensive low isotope-uptake area after acetazolamide loading than at baseline. In control patients, baseline images presented Type I in 25, Type II in 7, and the Type III & IV in 0, and the Type after loading was the same as the Type at baseline. CONCLUSION We established the qualitative evaluation of 123I-IMP SPECT image by detecting the "extent" of the ischemic region, taking notice of watershed. The pathognomonic findings on SPECT image of atherosclerotic large-artery disease showed that low isotope-uptake area at baseline extended into two watersheds or MCA territory by acetazolamide loading. The modality of qualitative evaluation based on these pathognomic findings of SPECT image may be useful for easily assessing patients with atherosclerotic large-artery disease using a rotating gamma camera.

Comparative effects of chelating agents on distribution, excretion, and renal toxicity of gold sodium thiomalate in rats

The effects of various chelating agents, such as (2S)-1-(3-mercaptopropionyl)-L-proline (captopril), N-(2-mercaptopropionyl)-glycine (tiopronin), L-cysteine (L-Cys), D-cysteine (D-Cys), N-acetyl-L-cysteine (L-NAC), N-benzyl-D-glucamine dithiocarbamate (BGD), and ethylenediaminetetraacetate (EDTA), on the distribution, excretion, and renal toxicity of gold sodium thiomalate (AuTM) in rats were investigated. Rats were intraperitoneally injected with the chelating agents (1.2 mmol/kg each) immediately after intravenous injection of AuTM (0.026 mmol/kg). Treatment with captopril or tiopronin significantly prevented increases in the urinary excretion of protein, aspartate aminotransferase (AST), and glucose and the blood urea nitrogen (BUN) level after AuTM injection. L-NAC and D-Cys significantly prevented increases in the urinary excretion of protein, AST, and glucose after AuTM injection, but did not reduce to control levels. Treatment with BGD, EDTA, or L-Cys did not prevent AuTM-induced increases in the urinary excretion of protein, AST, and glucose and BUN level. Tiopronin significantly increased the urinary excretion of gold. Captopril slightly promoted both the urinary and fecal excretion of gold, resulting in the significant increase in the total excretion of the metal. Tiopronin and captopril significantly decreased the gold concentration in the kidney and liver. L-Cys, D-Cys, L-NAC, BGD, and EDTA had no significant effect on the excretion or distribution of gold at 7 days after AuTM injection. These results indicate that tiopronin and captopril can ameliorate the renal toxicity induced by AuTM. In addition, the comparative effects of 2,3-dimercaptopropane sulfonate (DMPS), N-(2-mercapto-2-methylpropanoyl)-L-cysteine (bucillamine), captopril, and tiopronin at various dose levels (1.2, 0.4 or 0.2 mmol/kg) on the distribution and renal toxicity of gold were studied. DMPS was effective in removing gold from the kidney and in protecting against the renal toxicity after AuTM injection at the even lower dose level (0.2 mmol/kg). Bucillamine and tiopronin protected against the renal toxicity of gold at dose levels of 0.4 and 1.2 mmol/kg and captopril ameliorated the gold toxicity only at higher dose level (1.2 mmol/kg).

Mechanism of mobilization of renal and hepatic cadmium by dithiocarbamates in mice

To clarify the mechanism of mobilization of renal and hepatic cadmium (Cd) by N-benzyl-D-glucamine dithiocarbamate (BGD) and N-p-hydroxymethylbenzyl-D-glucamine dithiocarbamate (HBGD) in mice exposed to Cd, the effects of pretreatment with probenecid, an organic anion transport inhibitor, or with acivicin, a gamma-glutamyltranspeptidase (gamma-GTP) inhibitor and ureter-ligation were investigated on the excretion and distribution of chelating agents and Cd. The renal contents of BGD and HBGD were increased by ureter-ligation and decreased by acivicin pretreatment. The mobilizing effect of BGD on the renal Cd was inhibited by probenecid pretreatment. The action of HBGD in removing Cd from the kidney was inhibited by both probenecid pretreatment and ureter-ligation. These results suggest that BGD and HBGD are mainly taken up into the renal tubular cells through the basolateral membrane which is dependent on the action of gamma-GTP; that the Cd-BGD complex formed in the tubular cells is secreted by a probenecid-sensitive organic anion transport system through the basolateral membrane; and that the Cd-HBGD complex formed in the tubular cells is secreted to the tubular lumen by an organic anion transport system through the brush border membrane. Probenecid pretreatment increased the hepatic contents of BGD and HBGD and also promoted the effects of these chelating agents in removing Cd from the liver, indicating an inhibitory effect of probenecid on the glucuronidation of BGD and the secretion of HBGD from the kidney. These results suggest that BGD and HBGD are taken up into the liver and secreted from the organ to the bile by a transport system other than a probenecid-sensitive transport mechanism.

Protective effects of dithiocarbamates against renal toxicity of cis-diamminedichloroplatinum in rats

Sodium diethyldithiocarbamate (DDTC), sodium N-benzyl-D-glucamine dithiocarbamate (BGD), sodium N-p-hydroxymethylbenzyl-D-glucamine dithiocarbamate (HBGD), and sodium N-p-carboxybenzyl-D-glucamine dithiocarbamate (CBGD) were evaluated for efficacy as inhibitors of cis-diamminedichloroplatinum (DDP)-induced nephrotoxicity in a rat model. Treatments with 2.0 mmol/kg of BGD, HBGD, and CBGD immediately after DDP (20 mumol/kg) injection effectively prevented the nephrotoxic effects of DDP, but administration of DDTC immediately after DDP injection afforded a small protection. Concurrent treatment with 0.5 or 1.0 mmol/kg of HBGD, or 1.0 mmol/kg of CBGD could prevent DDP-induced renal damage. A significant decrease in weight loss was also observed in these dithiocarbamate-rescued rats. The platinum concentrations in liver and kidney were significantly decreased by BGD, HBGD, and CBGD treatments, respectively. The antitumor efficacy of DDP in the Walker 256 carcinoma-bearing rats was not affected by administration of HBGD (1.0 mmol/kg) or CBGD (1.0 mmol/kg). The results of this study indicated that the injection of HBGD or CBGD to rats treated with DDP can protect against DDP-induced nephrotoxicity more effectively than DDTC or BGD.

Effects of long-term infusion of synthetic atrial natriuretic factor on hemodynamics and water input-output balance in patients with acute myocardial infarction

The administration of atrial natriuretic factor (ANF) increases coronary blood flow and decreases coronary vascular resistance. However, little is known about the feasibility and reliability of intravenous long-term infusion of ANF in patients with coronary heart disease. We therefore examined the effects on hemodynamic parameters and water input-output balance of 24-hour administration of synthetic ANF (ANF-[99-126]: 20-50 ng/kg/min) in 8 patients with acute myocardial infarction (6 men and 2 women; mean age 55 years). The ANF infusion significantly decreased pulmonary capillary wedge pressure to a maximum of greater than 50% 4 hours after infusion (from 16 +/- 2 to 7 +/- 2 mmHg; p < 0.01), and the effect was sustained throughout the 24-hour infusion without diuresis (mean water balance, + 25 +/- 12 ml/hr). This reduction was significantly correlated with the baseline value before infusion (r = -0.85, p < 0.01). The effect on pulmonary capillary wedge pressure was accompanied by small reductions (approximately 20%) in systemic blood pressure and cardiac index, without significant changes in systemic vascular resistance and heart rate. These results indicate that prolonged administration of low to medium doses of synthetic ANF causes potent and sustained left ventricular unloading without reflex, tachycardia and volume depletion, and may thus be safe and have potential benefits for patients with coronary heart disease.

Prediction of cerebral infarction due to vasospasm following aneurysmal subarachnoid haemorrhage using acetazolamide-activated 123I-IMP SPECT

Prediction of cerebral infarction due to vasospasm (VS) following aneurysmal subarachnoid haemorrhage (SAH) was investigated using acetazolamide-activated (A-A) N-isopropyl-p-[123I]iodoamphetamine (123I-IMP) single photon emission computed tomography (SPECT) in 79 SAH patients. A-A SPECT was undertaken twice or more for one each patient by Day 18. Fifty-six (71%) of the 79 patients presented with reduction of cerebral vasodilatory capacity (CVC) on SPECT due to VS by Day 18. Of the 56 patients, 29 showed CVC by Day 8 (Group A), while the other 27 first showed CVC reduction between Day 9 and 18 (Group B). Cerebral infarction on CT was revealed by Day 18 in 15 patients (52%) of Group A and 3 (11%) of Group B. Of the 56 patients, 20 showed reduced CVC in watershed[s] (Type 1), 12 in a sole territory of the intracranial major arterial trunk (Type 2), and 24 in several territories or in a sole territory with distant watershed[s] (Type 3). Cerebral infarction on CT by Day 18 was revealed in one patient (5%) in Type 1, 3 (25%) in Type 2, and 14 (58%) in Type 3. Twelve (71%) of 17 patients belonging to both Group A and Type 3 resulted in cerebral infarction. These results suggest that early and extensive CVC reduction are significant factors responsible for cerebral infarction due to VS following SAH. Cerebral infarction can be reasonably predicted using A-A SPECT in SAH patients.

Primary osteosarcoma of the skull--a case report and review of the literature

Primary osteosarcoma of the skull (POS) in a young man with intracranial involvement is reported. After an initial transient remission by surgical intervention and chemotherapy, he began to deteriorate due to tumor recurrence and intracranial hemorrhage, and died 15 months following the time of diagnosis. The rarity and poor prognosis of POS are emphasized together with the review of the clinical and therapeutic aspects in the previously reported 98 cases in the literature.

Increased plasma endothelin concentrations in patients with acute heart failure after myocardial infarction

We have investigated the relationship between plasma endothelin (ET) concentrations and several clinical characteristics in 31 patients with acute myocardial infarction (MI). ET levels were also measured in 10 age-matched healthy subjects, 9 patients with unstable angina, and 20 patients with chronic heart disease. In patients with MI, although no significant relationship was observed between plasma ET concentrations and measured hemodynamic parameters, plasma levels were higher in patients with pulmonary congestion than in those without this complication (1.61 +/- 0.29 vs 1.21 +/- 0.33 fmol/ml; p < 0.01). No significant difference in plasma ET levels was found between cardiac and peripheral sampling sites (pulmonary artery; 1.07 +/- 0.28, right atrium; 1.02 +/- 0.28, peripheral artery; 1.12 +/- 0.23, peripheral vein; 1.14 +/- 0.38 fmol/ml: N.S.), or among patients with uncomplicated MI, unstable angina (1.00 +/- 0.32 fmol/ml), and healthy subjects (1.01 +/- 0.29 fmol/ml). Increased level were observed in patients with decompensated heart failure due to chronic heart disease, but were not found in patients without pulmonary congestion (1.62 +/- 0.60 vs 1.11 +/- fmol/ml; p < 0.01). These observations suggest that plasma ET concentrations are elevated in the presence of congestive heart failure or severe ventricular depression, but are not persistently increased by myocardial ischemia per se.

Protective effects of dithiocarbamates against toxicity of cis-diamminedichloroplatinum in mice

The protective effects of various dithiocarbamates such as N-benzyl-D-glucamine dithiocarbamate (BGD), N-p-hydroxymethylbenzyl-D-glucamine dithiocarbamate (HBGD), N-p-carboxybenzyl-D-glucamine dithiocarbamate (CBGD), and diethyldithiocarbamate (DDTC) on cis-diamminedichloroplatinum (DDP)-induced toxicity in mice were studied. The mice were injected i.v. with a chelating agent (1 mmol/kg) immediately or 5 min after i.v. injection of DDP (15 or 20 mg/kg). The lethal toxicity of DDP (20 mg/kg) was completely prevented by treatment with HBGD or CBGD immediately after DDP. The survival time of mice treated with HBGD or CBGD 5 min after DDP tended to be longer than that treated with BGD or DDTC. Significant increases in blood urea nitrogen (BUN) level and plasma aspartate aminotransferase (AST) activity were observed 3d after DDP injection. The increase in BUN level was completely prevented only by HBGD and CBGD among these chelating agents, while increase in AST activity was significantly prevented by treatment with these two agents. Treatment with HBGD or CBGD immediately after DDP (20 mg/kg) completely protected against DDP-induced diarrhea. These chelating agents significantly decreased the platinum (Pt) contents in the kidney and liver after DDP administration. Treatment with HBGD or CBGD was the most effective in decreasing the renal Pt content, resulting in maximum protection against DDP-induced renal damage. The antitumor efficacy of DDP (15 mg/kg) in the colon 26 carcinoma-bearing mice was not affected by HBGD administration.

N-benzyl-D-glucamine dithiocarbamate and N-p-isopropylbenzyl-D-glucamine dithiocarbamate improve the protective effect of diethyldithiocarbamate against cadmium-induced testicular toxicity in rats

The protective effects of combined treatment with diethyldithiocarbamate (DED) plus N-benzyl-D-glucamine dithiocarbamate (BGD) or DED plus N-p-isopropylbenzyl-D-glucamine dithiocarbamate (PBGD) against the testicular toxicity caused by acute exposure to cadmium (Cd) in rats were studied. Rats were injected subcutaneously with 109CdCl2 (3 mg Cd and 74 kBq of 109Cd/kg) and 30 min later, they were injected intraperitoneally with the chelating agents (1 mmol/kg each). Cd injection increased lipid peroxidation and concentrations of hemoglobin, Ca and Fe in the testes, decreased the testicular weight and nonprotein SH (NP-SH), and caused sterility. The coadministration of DED with BGD or PBGD significantly prevented the increase in the lipid peroxidation, hemoglobin, Ca and Fe in the testes, the decrease in the testicular weight and NP-SH, and the sterility caused by Cd injection. DED plus BGD or DED plus PBGD significantly decreased the Cd concentration in the testes without the redistribution of Cd to the brain and kidney, which is observed following treatment with DED alone. The coadministration of DED plus BGD or DED plus PBGD significantly increased the blood Cd concentration and the Cd distribution in the red blood cells compared to Cd alone. These results indicate that the coadministration of BGD or PBGD with DED prevents the accumulation of Cd in the testes on the basis of greater blood distribution of Cd, which results from the uptake of Cd by the red blood cells, without the redistribution of Cd to the brain, resulting in an improvement of the protective effect of DED against the Cd-induced testicular toxicity.

Prognostic implications of plasma levels of atrial natriuretic factor in patients with acute myocardial infarction

Several neurohormonal factors have been proposed as markers of the severity of acute myocardial infarction (MI). To determine whether plasma concentrations of atrial natriuretic factor (ANF) might predict post-MI prognosis, we studied 130 patients with acute MI (97 males and 33 females, mean age 62 years). Within one-half to one day after admission, a blood sample was taken for estimation of circulating ANF. The mean follow-up period was 37 months, and the follow-up rate was 97%. Of the 130 patients, 28 died from cardiac causes during the follow-up period. Patients were classified into three groups according to plasma ANF levels (group 1, < 99 pg/ml; group 2, 100-199 pg/ml; group 3; > 200 pg/ml). The survival curves were constructed by the Kaplan-Meier method. There were significant differences in the cumulative survival rate among the three groups (group 1 > group 2 > group 3; p < 0.001). The baseline characteristics (age, atrial pressure, and cardiac index) were different among the groups, therefore these variables were analyzed by a Cox multiple regression model. Significant predictors of cardiac mortality were plasma ANF class (p < 0.002) and pulmonary capillary wedge pressure (p < 0.007). In conclusion, these observations demonstrated that stratification of acute MI patients by plasma ANF level is a useful non-invasive method for predicting prognosis and for identifying individuals at high risk of cardiac death.

Prevention of renal toxicity of cis-diamminedichloroplatinum by dithiocarbamates in rats

The protective effects of various dithiocarbamates such as N-benzyl-D-glucamine dithiocarbamate (BGD), N-p-hydroxymethylbenzyl-D-glucamine dithiocarbamate (HBGD), N-p-carboxybenzyl-D-glucamine dithiocarbamate (CBGD), and N-methyl-D-glucamine dithiocarbamate (MGD) on DDP-induced renal toxicity in rats were studied. The rats received the simultaneous i.v. injection of DDP (20 mumol/kg) and a chelating agent (40 mumol/kg). Significant increase in blood urea nitrogen (BUN) level was observed 5 days after DDP injection. The increase in BUN level was completely prevented by only HBGD and CBGD among these chelating agents. Treatment with CBGD completely prevented against DDP-induced body weight loss. BGD and MGD treatment did not prevent the increase in BUN level or body weight loss. HBGD and CBGD were the most effective in decreasing the renal platinum content, resulting in maximum protection against the DDP-induced renal damage. The antitumor efficacy of DDP in the Walker 256 carcinoma-bearing rats was not affected by CBGD administration.