Pharmacokinetic study of aniracetam in elderly patients with cerebrovascular disease

The clinical pharmacokinetics of the cognitive enhancer, aniracetam (200 mg), was studied in elderly patients with cerebrovascular disease (CVD) and compared with those of young healthy volunteers. Six female hospitalized patients (mean age 84.5 years) were used in this study. The serum level of anisic acid and p-methoxyhippuric acid, major metabolites of aniracetam, reached a peak at 2 h after oral administration, and returned to basal level by 6 h. Mean creatinine clearance was 20-30 ml/min. The t1/2 of metabolites was increased by 4- to 7-fold in the elderly patients compared with young volunteers. This study showed that tmax, t1/2, and AUC were enlarged in the elderly; however, no clinical side effects were observed.

Polymerase chain reaction-based approaches for detection of allelic loss in the p53 tumor suppressor gene in colon neoplasms

OBJECTIVES

Inactivation of the p53 tumor suppressor gene is considered to be a late event involved in the malignant transformation of colorectal adenoma to cancer. Thus, its detection is thought to provide useful information for the clinical management of colorectal neoplasms. We devised a rapid screening test for allelic loss of the p53 gene by non-radioisotopic single-strand conformation polymorphism analysis.

METHODS

Biopsy materials from 119 colorectal tumors obtained at endoscopy were examined. Three intragenic polymorphic sites were amplified by polymerase chain reaction using DNA extracted from these materials, and amplified DNA fragments were subjected to non-radioisotopic single-strand conformation polymorphism.

RESULTS

This method can detect a loss of heterozygosity (LOH) of the p53 locus from samples containing over 40% tumor derived DNA, and the combination of the three polymorphic markers encompassed 62.4% of Japanese patients as informative. In adenocarcinoma, an LOH was detected in 51.5% (17 of 33) of the samples and in 12.2% (4 of 33) of tubular and/or tubulovillous adenomas. The p53 gene was mutated only in samples carrying an LOH, that is 64.7% (11 of 17) of carcinomas and 25.0% (1 of 4) of adenomas, but there were no mutation in samples retaining both alleles. The presence of an LOH was statistically correlated both with p53 mutation and malignant histology (chi 2 test, p < 0.05).

CONCLUSIONS

This method can detect LOH from biopsy material obtained at endoscopy. LOH in the p53 locus precedes mutation of the p53 gene, and its detection provides useful information of malignancy in colorectal tumors.

Cervical spinal cord compression in hereditary multiple exostoses. Report of a case and a review of the literature

Spinal cord compression is an extremely serious complication of hereditary multiple exostoses (HME). A case of HME with compression of the cervical spinal cord is reported. Complete recovery following surgery was achieved. A review of the relevant literature revealed 51 previous cases of HME with cord/cauda equina compression. Most patients were under 30 years of age with more men affected than women. The family history was positive in 60%. The cervical and thoracic areas were predominantly affected, with the symptoms usually developing slowly. Recovery following surgery is to be expected in the majority of cases. In patients with HME and suffering from neurological symptoms, the possibility of spinal cord compression should be considered. Prompt diagnosis and surgical excision provide the best prognosis.

Implication of the negative U wave during dobutamine stress echocardiography

Although the development of negative U waves during exercise is a highly specific marker for detecting coronary artery disease, their assessment during exercise is difficult. The clinical significance of the negative U wave during dobutamine stress echocardiography was investigated in 181 patients who had suspected coronary artery disease. Dobutamine-induced negative U waves appeared in 28 patients (16%) during dobutamine infusion. Coronary angiography showed coronary artery disease in 114 of the 181 patients. The sensitivity and specificity of the negative U wave for detecting coronary artery disease were 22 and 96%, respectively, while the corresponding values for ischemic ST-T changes were 49 and 76%, respectively. The negative U wave appeared during low-dose infusion of dobutamine (5-10 microg/kg/min) in 82% of the patients with this wave. In the 21 patients who had both a negative U wave and an inducible regional wall motion abnormality during dobutamine infusion, the development of the negative U wave was either simultaneous with or earlier than that of the wall motion abnormality. Although its sensitivity was low, the negative U wave during dobutamine stress echocardiography is a highly specific marker for detecting coronary artery disease. Because of its earlier appearance as compared with that of the wall motion abnormality, the dobutamine-induced negative U wave may be considered to be an early and useful adjunctive sign for detecting coronary artery disease during dobutamine stress echocardiography.

Tissue distribution and subcellular localization of rabbit liver metalloendopeptidase

We have previously isolated rabbit liver microsomal metalloendopeptidase (MEP) as a candidate for the processing enzyme of vitamin K-dependent plasma proteins. A cDNA coding for MEP has revealed that it is structurally related to metalloendopeptidase-24.15, which catalyzes the proteolytic processing of several bioactive peptides. In this study we examined the tissue distribution and subcellular localization of MEP by light and electron microscopic immunohistochemical methods, in addition to Northern blot analysis. Chicken polyclonal antibodies were raised by using synthetic peptides AG1 (Met31-Asn46) and AG3 (Asp537-Gly551) derived from the sequence of MEP. Both anti-AG1 and anti-AG3 antibodies reacted specifically with MEP, as judged by Western blotting and immunohistochemical methods. Both antibodies gave an identical staining distribution, which was localized on the luminal cell surfaces and in the cytoplasm of the following organs: liver, brain, lungs, kidneys, esophagus, stomach, duodenum, pancreas, placenta, epididymis, uterus, ovary, and oviduct. Northern blot analysis revealed that the expression of MEP mRNA is similar to its immunohistochemical distribution except in the heart. These results suggest that MEP may participate more closely in a degradation role in peptide metabolism in various tissues than in a processing role of the proprotein, like metalloendopeptidase-24.15.

Role of K+ channels in EDHF-dependent relaxation induced by acetylcholine in canine coronary artery

To identify the K+ channels responsible for endothelium-derived hyperpolarizing factor (EDHF)-dependent relaxation, we studied the effects of various K+ channel blockers on acetylcholine-induced relaxation, which persists even in the presence of both an inhibitor of nitric oxide synthase and that of cyclooxygenase, in canine coronary artery rings. A nonselective K+ channel blocker, tetrabutylammonium (TBA), a large and intermediate conductance Ca2+-activated K+ channel blocker, charybdotoxin (CTX), and a voltage-dependent K+ channel blocker, 4-aminopyridine (4-AP), significantly inhibited this residual relaxation. A combined treatment with CTX and 4-AP almost completely blocked the relaxation. Neither a large (iberiotoxin) nor a small (apamin) conductance Ca2+-activated K+ channel blocker blocked the relaxation. We also investigated effects of K+ channel blockers on basal tone to determine whether or not EDHF is involved in regulating basal tone. TBA and CTX substantially raised basal tone to a greater degree in endothelium-intact preparations than in endothelium-denuded preparations. These results indicate that EDHF may exert its relaxing action through intermediate conductance Ca2+-activated and voltage-dependent K+ channels in canine coronary arteries. In addition, EDHF may play a role in maintaining basal vascular tone.

Effects of some calcium-related agents on the protoplast transfection of Lactobacillus casei with phage PL-1 DNA

To clarify the mechanism of Ca2+ involvement in the DNA transfer through cell membrane, we studied the effects of Ca2+-chelator, Ca2+-ionophore, and Ca2+-channel blocker on the protoplast transfection of Lactobacillus casei ATCC 27092 by PL-1 phage DNA in the presence of Ca2+. Ca2+-chelators, citrate, EDTA, and dipicolinic acid, inhibited the transfection probably by compensating the effect of Ca2+. Ca2+-ionophores, A23187 and N,N,N', N'-tetracyclohexyl-3-oxapentanediamide, which were expected to accelerate transfection by introducing Ca2+ into cells, inhibited the transfection. This fact indicated the absence of correlation between the entry of Ca2+ and the transport of DNA into protoplasts. Verapamil, which blocks voltage-dependent Ca2+-channel besides beta-adrenergic receptor, inhibited the transfection with little effect on the survival of the protoplasts. Both flunarizine and vinpocetine, voltage-dependent Ca2+-channel blockers, did not show the selective toxicity. D-alpha-Aminoadipic acid, a glutamate receptor-operated Ca2+-channel blocker, had no effect. Propranolol, which blocks beta-adrenergic receptor as does verapamil, inhibited the transfection without severely damaging the protoplasts. These results suggested that a kind of receptor-operated Ca2+-channel was involved in the transport of PL-1 phage DNA into the cells and that the cell membrane might have a receptor structure somewhat similar to the beta-adrenergic receptor found in mammalian cells.

Simvastatin increases plasma NO2- and NO3- levels in patients with hypercholesterolemia

In this study, plasma NO2- and NO3- (NOx-) levels were studied after lowering cholesterol with simvastatin in 26 outpatients with hypercholesterolemia (male, 9; female, 17; mean age, 59 +/- 12 years; cholesterol level > 220 mg/dl). Simvastatin (5 mg) was orally administered once daily, and blood samples were collected before, and after 4 and 12 weeks of treatment. Total, very-low-density lipoprotein (VLDL), and low-density lipoprotein (LDL) cholesterol were lowered (total, 254 +/- 44 mg/dl to 209 +/- 34 mg/dl; VLDL, 48 mg/dl [5-126 mg/dl] to 34 mg/dl [10-67 mg/dl]; LDL, 171 +/- 41 mg/dl to 133 +/- 37 mg/dl), but high-density lipoprotein (HDL) cholesterol was elevated (33 +/- 9.5 mg/dl to 39 +/- 11 mg/dl) at 12 weeks after starting simvastatin. Although the effects of simvastatin on the lipid levels nearly reached their maximum levels at 4 weeks, NOx- was elevated in a linear fashion with simvastatin (before; 8 +/- 17 mumol/l, at 12 weeks; 57 +/- 32 mumol/l). The % changes in the NOx- correlated directly with those in HDL-cholesterol at 12 weeks (P < 0.002) but not with other lipoprotein cholesterol fractions. These results suggest that simvastatin lowers cholesterol levels and elevates HDL while increasing the plasma NOx- levels.

Life-threatening cardiac involvement throughout life in a case of Costello syndrome

Costello syndrome is characterized by poor postnatal growth, mental retardation, curly hair, coarse face, loose skin of the hands and feet, and nasal papillomata. Patients with Costello syndrome have a high incidence of cardiac involvement, such as arrhythmias, hypertrophic cardiomyopathy, or congenital anomalies. The importance of cardiac involvement in Costello syndrome has not been strongly emphasized thus far, although arrhythmia and hypertrophic cardiomyopathy are both serious forms of cardiac involvement. We report the case of a Japanese girl with Costello syndrome, who experienced life-threatening cardiac involvement throughout her life.

Detection of respiratory frequency in the recordings of electrocardiogram, blood pressure or sympathetic nerve activity in the conscious rat

We extracted the respiratory frequency in conscious rats from variations of blood pressure, electrocardiogram, or renal sympathetic nerve activity by means of a band-pass filter. The frequency derived from any one of these parameters corresponded to directly recorded respiratory chest movements. The method may be useful when respiration and cardiovascular parameters have to be recorded in small animals during steady state when minimal surgical intervention is crucial.

Characterization of in vivo gene transfer into the arterial wall mediated by the Sendai virus (hemagglutinating virus of Japan) liposomes: an effective tool for the in vivo study of arterial diseases

Recently, much attention has been paid to the arterial gene transfer technique using several vector systems. In the present study, we experimentally examined the transfection efficiency of the exogenous gene, the duration of gene expression, and the cytotoxic effect of the hemagglutinating virus of Japan (HVJ) liposome on the intact arterial wall to evaluate its effectiveness for the study of arterial diseases. To evaluate the transfection efficiency and duration of gene expression, pSV beta-galactosidase was transferred into the carotid arterial wall of rabbits. The cytotoxic effect of HVJ liposomes on the vascular cell components was also evaluated by a neutral red assay in vitro and scanning electron microscopy in vivo. HVJ liposomes could achieve highly efficient gene transfection into the medial smooth muscle cells of intact arteries at 150 and 760 mmHg of pressure (mean = 85.3% and 93.5% of total smooth muscle cells, respectively) without any inflammatory reaction. The introduced exogenous gene was expressed for at least 14 days. In addition, the cytotoxicity for the arterial smooth muscle cells and endothelial cells induced by HVJ liposome vehicles at routinely used concentrations (5,000 to 10,000 hemagglutinating activity units/ml) was minimal both in vitro and in vivo. As an example, we introduced human vascular endothelial growth factor cDNA, which was driven with cytomegalovirus enhancer and beta-actin promoter, into the rabbit carotid arteries, and it induced not only angiomatoid proliferation of endothelial cells forming irregular vascular channels but also intimal hyperplasia. Based on these findings, we conclude that HVJ liposome-mediated arterial gene transfer is a highly efficient, noninvasive, and effective gene delivery method for the study of vascular disorders.

Induction of renal cell carcinoma in male Wistar rats treated with cupric nitrilotriacetate

Systemic administration of copper, an essential trace metal in the human body, has never been reported to be carcinogenic in animals. We investigated the induction of tumors by the cupric complex of nitrilotriacetic acid (Cu-NTA) in male Wistar rats. Thirty-two animals received ip injections of Cu-NTA, 3 to 5 mg of copper/kg body weight 5 days a week for 12 weeks, and were kept under close observation. For comparison, 31 animals received ip injections of ferric nitrilotriacetate (Fe-NTA), 5 to 10 mg of iron/kg body weight, and 16 animals received nitrilotriacetic acid (NTA) alone at the molar dose equivalent to Cu-NTA for the same period of time. Sixteen animals were left untreated as controls. Fourteen animals in the Cu-NTA group died of hepatic failure during the treatment period, and renal cell carcinoma (RCC) was induced in eight animals (25%). Of these, four animals died of either pulmonary metastasis or intraperitoneal hemorrhage. A total of 12 RCC were obtained, of which six tumors were > or = 5 mm. The Cu-NTA group yielded fewer RCC and required a longer latent period for their incubation than the Fe-NTA group. Furthermore, the Cu-NTA group showed one hepatocellular carcinoma and one high-grade sarcoma of hepatic origin. No renal or hepatic tumor was observed in the NTA or control groups. The nontumorous part of the kidney treated with Cu-NTA presented hemosiderosis caused by copper-induced hemolytic anemia. This is the first report that systemic administration of copper compounds can induce malignant tumors in animals. Not only copper but also iron may play a role in the Cu-NTA-induced renal carcinogenesis model.

Salivary duct carcinoma: a clinicopathologic study of three cases with a review of the literature

Three cases of salivary duct carcinoma are presented. They occurred in a 60 year old man, a 66 year old man and a 57 year old woman. All of the lesions were located in the parotid gland. The tumor size ranged from 3 to 5 cm across the largest diameter. Facial paralysis was observed in two cases. Histologically, intraductal and invasive adenocarcinoma showing papillary, cribriform, and solid patterns with comedolike necrosis was observed. Immunohistochemically, the tumor cells were positive for keratin and epithelial membrane antigen. No myoepithelial cells were demonstrated within the tumor by staining for S-100 protein, alpha-smooth muscle actin or muscle specific actin. Ultrastructurally, intracytoplasmic lumina with microvilli, a moderate number of mitochrondria, lysosomes, and tight junctions were found. Regional lymph node metastasis was observed in one case, and distant metastasis developed in two cases. All of the patients were treated with adjuvant postoperative irradiation. One patient died of disease at 11 months after the initial diagnosis, another was alive with disease at 8 months, and the third patient was alive without disease at 2 years and 3 months. Salivary duct carcinoma should be differentiated from low-grade salivary gland carcinomas using morphologic and clinical criteria because of its poor prognosis even with aggressive therapy.

Three-dimensional structure of a DNA repair enzyme, 3-methyladenine DNA glycosylase II, from Escherichia coli

The three-dimensional structure of Escherichia coli 3-methyladenine DNA glycosylase II, which removes numerous alkylated bases from DNA, was solved at 2.3 A resolution. The enzyme consists of three domains: one alpha + beta fold domain with a similarity to one-half of the eukaryotic TATA box-binding protein, and two all alpha-helical domains similar to those of Escherichia coli endonuclease III with combined N-glycosylase/abasic lyase activity. Mutagenesis and model-building studies suggest that the active site is located in a cleft between the two helical domains and that the enzyme flips the target base out of the DNA duplex into the active-site cleft. The structure of the active site implies broad substrate specificity and simple N-glycosylase activity.

PET study of the M1-agonists [11C]xanomeline and [11C]butylthio-TZTP in monkey and man

Xanomeline, a substituted TZTP, is a new M1 selective muscarinic agonist in clinical trials for Alzheimer's disease. The brain uptake of [11C]xanomeline and the analog [11C]butylthio-TZTP was examined by positron emission tomography (PET). Radioactivity accumulated most markedly in the neocortex and the striatum. Pharmacological characterization in vitro and in cynomolgus monkeys in vivo by PET indicated specific [11C]butylthio-TZTP binding to muscarinic receptors and to sigma-1 recognition sites. More than 5% of the radioactivity was in the human brain 5 min after i.v. injection of [11C]xamomeline or [11C]butylthio-TZTP. This high brain uptake may be clinically advantageous in the sense that substituted TZTP may induce central muscarinic agonist effects at a dose level for which there is a low risk of peripheral side-effects.

Ca(2+)/calmodulin-dependent protein kinase II inhibitor KN-62 inhibits adrenal medullary chromaffin cell functions independent of its action on the kinase

KN-62, an inhibitor of Ca2+/calmodulin-dependent protein kinase II (CaM kinase II), inhibited significantly catecholamine secretion and tyrosine hydroxylase activity stimulated by acetylcholine in cultured bovine adrenal medullary cells. KN-62, however, showed an additional inhibitory effect on acetylcholine-induced 45Ca2+ influx, which is essential for functional responses. Carbachol-stimulated 22Na+ influx, veratridine-induced 22Na+ influx, and 56 mM K(+)-evoked 45Ca2+ influx were also attenuated by KN-62. Inhibitions by KN-62 of these ion influxes were correlated closely with those of catecholamine secretion. KN-04, which is a structural analogue of KN-62 but does not inhibit CaM kinase II activity, elicited inhibitory effects on the three kinds of stimulant-evoked ion influxes with an inhibitory potency similar to KN-62. These results suggest that KN-62 inhibits catecholamine secretion and tyrosine hydroxylase activation due to mainly its ion channel blockade on the plasma membrane rather than the inhibition of CaM kinase II activity in the cells.

[11C]beta-CIT-FE, a radioligand for quantitation of the dopamine transporter in the living brain using positron emission tomography

The cocaine analogue beta-CIT-FE (N-(2-fluoroethyl)-2 beta-carbomethoxy-3 beta-(4-iodophenyl)nortropane) was labeled with 11C for positron emission tomography (PET) studies of the dopamine transporter. After intravenous administration to a cynomolgus monkey, [11C]beta-CIT-FE accumulated in the striatum with a striatum-to-cerebellum ratio of about 9 after 60 min. Pseudoequilibrium of specific [11C]beta-CIT-FE binding in the striatum was obtained within 30-50 min. The radioactivity ratios of the thalamus to the cerebellum and the neocortex to the cerebellum were about 2 and 1.5, respectively. In displacement and pretreatment experiments, radioactivity in the striatum but not in the cerebellum was reduced after injection of beta-CIT or the dopamine transporter inhibitor GBR 12909, indicating that striatal radioactivity following injection of [11C]beta-CIT-FE represents reversible binding to dopamine transporter sites. After displacement or pretreatment with cocaine there was a marked effect not only in the striatum but also in the thalamus and neocortex. [11C]beta-CIT-FE has potential as a useful PET radioligand for quantitation of the dopamine transporter in the primate brain in vivo.

Sensitive detection of loss of heterozygosity in the TP53 gene in pancreatic adenocarcinoma by fluorescence-based single-strand conformation polymorphism analysis using blunt-end DNA fragments

We have developed a fluorescence-based single-strand conformation polymorphism analysis to detect Haelil-sensitive polymorphic sites in intron 1 of the TP53 gene. It is important to treat the PCR products with Klenow fragment to remove a 3'-protruding nucleotide from the amplified DNA fragments added during the reaction in order to obtain a single peak for each allele. A comparison of the signal profiles of two alleles with those of normal heterozygotes by data processing using computer software has enabled sensitive detection of loss of heterozygosity (LOH) from clinical materials with a fraction of tumor cells below 10%. In analysis of 14 pancreatic carcinomas in which the proportion of the tumor cells is usually low due to the abundance of the stromal component, 7 samples (50%) were informative and 5 of the 7 (71.4 %) were positive for LOH at the TP53 locus. This approach would be useful for allelotyping tumors with low cellularity, as well as other clinical samples such as biopsied specimens and paraffin embedded tissues.

Effects of dietary vegetable oils on behavior and drug responses in mice

Previously, we noted significant differences in the behavioral patterns of mice fed safflower oil with a very low alpha-linolenate/linoleate ratio and perilla oil with a high alpha-linolenate/linoleate ratio from mothers to offsprings. In this report, we compared the behavior and drug responses in mice fed diets containing six different vegetable oils-corn, rapeseed, soybean, safflower, perilla and a mixture of perilla and safflower oils- for a relatively short period: 8 months after weaning. Soybean oil is a component of most conventional diets and was used as a control. The alpha-linolenate/linoleate ratios of the oils appeared to affect the locomotor activities in a wheel cage: the activity decreased in the order of safflower, the mixture (1:1) and the perilla oil groups. However, the rapeseed oil group exhibited much higher locomotor activity than that expected from the alpha-linolenate/linoleate ratio. Additionally, the rapeseed oil group exhibited unusual behavior patterns, including higher ambulation and rearing activities, faster acquisition of the water maze task and slower habituation behavior as compared with the control group. Susceptibility to pentobarbital anesthesia tended to be higher in the rapeseed oil group. The differences in the alpha-linolenate/linoleate ratios of these oils alone do not account for the observed differences in the behavioral patterns among the six dietary groups. Although we cannot exclude the possibility that the observed behavioral anomaly is due to the unique fatty acid composition of rapeseed oil, we speculate that a factor(s) other than fatty acids in rapeseed oil affected nervous system functions.

Role of tissue inhibitors of metalloproteinase in diabetic nephropathy

We evaluated the role of tissue inhibitors of metalloproteinase-1 (TIMP-1) in patients with diabetic nephropathy by comparing the serum and urine TIMP-1 levels with those of renal biopsy specimens. A total of 35 diabetic patients were divided into four groups, D0, DI, DII and DIII-IV, according to the severity of diffuse glomerular lesions using Gellman's criteria. Using serum and 24-hour urine specimens, TIMP-1 was measured by a sandwich enzyme immunoassay. Serum and urinary TIMP-1 showed significant increases in association with the progress of glomerular diffuse lesions. There was no correlation between serum TIMP-1 and serum creatinine, creatinine clearance, serum and urinary beta 2-microglobulin, urinary NAG, HbA1c, or urinary TIMP-1. There was a significant correlation between urinary TIMP-1 and urinary albumin, and was a significant correlation between urinary TIMP-1 and urinary NAG. We conclude that TIMP-1 has a potential role in the regulation of glomerular matrix accumulation in diabetic nephropathy.

Quantitative analysis of ferrochelatase mRNA in blood cells of erythropoietic protoporphyria patients

Ferrochelatase (FC; heme synthetase, EC 4.99.1.1.) catalyses the synthesis of heme from protoporphyrin IX, the final step in the heme synthetic pathway. The hereditary deficiency of this enzyme gives rise to erythropoietic protoporphyria (EPP). We developed a rapid, non-radioactive means of measuring human FC mRNA levels in the EPP patients. It is based on the reverse transcriptase-polymerase chain reaction (RT-PCR) performed on the RNA obtained from peripheral blood. The amplified DNA was detected by agarose gel electrophoresis with ethidium bromide staining and the fluorescent intensity was measured by scanning densitometry applied directly to Polaroid 665 negative film. The relative expression level of FC mRNA, compared with that of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) mRNA, was estimated at several points in the exponential phase of PCR cycles or at a point in the exponential phase of PCR performed on serially diluted the cDNA samples. The estimate of the FC mRNA by this method correlated well with the level of the FC mRNA measured by Northern blotting in the EB virus-transformed lymphocytes of the same patients. The level of the FC mRNA appeared to vary among the patients in whom a decreased level of enzymatic activity was indicated.