Protective effect of zinc against ischemic neuronal injury in a middle cerebral artery occlusion model

In this study, we investigated the effect of vesicular zinc on ischemic neuronal injury. In cultured neurons, addition of a low concentration (under 100 microM) of zinc inhibited both glutamate-induced calcium influx and neuronal death. In contrast, a higher concentration (over 150 microM) of zinc decreased neuronal viability, although calcium influx was inhibited. These results indicate that zinc exhibits biphasic effects depending on its concentration. Furthermore, in cultured neurons, co-addition of glutamate and CaEDTA, which binds extra-cellular zinc, increased glutamate-induced calcium influx and aggravated the neurotoxicity of glutamate. In a rat transient middle cerebral artery occlusion (MCAO) model, the infarction volume, which is related to the neurotoxicity of glutamate, increased rapidly on the intracerebral ventricular injection of CaEDTA 30 min prior to occlusion. These results suggest that zinc released from synaptic vesicles may provide a protective effect against ischemic neuronal injury.

PTOV1: a novel testosterone-induced atherogenic gene in human aorta

There are gender differences in the development of atherosclerosis, possibly owing to differences in sex steroid hormone action and/or metabolism. One of the atherogenic effects of testosterone is thought to be androgen receptor (AR)-mediated vascular smooth muscle cell (VSMC) proliferation. However, the detailed mechanism of this effect, particularly the identity of the genes associated with VSMC proliferation, remains largely unknown. Therefore, we first employed microarray analysis and, subsequently, quantitative RT-PCR to analyse RNA expression in AR-positive human VSMCs treated with testosterone in order to detect testosterone-induced genes associated with cell proliferation. We further examined whether the genes identified were involved in cell proliferation using small interfering RNA (siRNA) transfection. Expression of the gene products was then evaluated in human aorta with various degrees of atherosclerosis in order to evaluate the clinical relevance of the findings. Both microarray and quantitative RT-PCR analyses demonstrated marked induction of the human prostate overexpressed protein 1 (PTOV1) gene by testosterone in the cell lines: this gene was recently identified as a novel androgen-induced gene involved in prostate tumour cell proliferation. Inhibition of PTOV1 by transfection of its corresponding siRNA suppressed testosterone-induced cell proliferation. In human aorta, PTOV1 immunoreactivity in the nuclei of neointimal VSMCs was abundantly detected in male aorta with mild atherosclerotic changes compared with female aorta or male aorta with severe atherosclerotic changes. These findings indicate that the PTOV1 gene is androgen-responsive in VSMCs and that it may play an important role in androgen-related atherogenesis in the human aorta, particularly early atherosclerosis in the male aorta, through regulating proliferation of neointimal VSMCs.

In Vivo Measurement of Presynaptic Zn2+ Release during Forebrain Ischemia in Rats

Previous studies have suggested that during forebrain ischemia, considerable Zn2+ is released from synaptic vesicles of gultamatergic neuronal terminals and accumulates in hippocampal CA1 pyramidal neurons, leading to delayed neuronal death. However, since a time lag exists between the accumulation of Zn2+ and the occurrence of ischemia and there are conflicting reports about the amount of Zn2+ released, the level of released Zn2+ during ischemia in vivo is still unclear. In this study, we investigated the temporal change of extracellular Zn2+ in the hippocampal CA1 area using microdialysis and the accumulation of Zn2+ in hippocampal CA1 neurons with TSQ staining in rats with a transient forebrain ischemia. The level of extracellular Zn2+ in the CA1 area increased transiently reaching a peak 15 min after occlusion, then decreased with time, returning to the basal level 15 min after reperfusion. In addition, at this peak, the level of extracellular Zn2+ was about twice the basal level. Assessment of the intracellular Zn2+ in hippocampal neurons with TSQ revealed that Zn2+ accumulate at 24 h, but not 0 and 6 h after ischemia. These results suggest that, although the synaptic vesicular Zn2+ is released into the synaptic cleft during ischemia in vivo, the amount of released Zn2+ might not be so excessive, and it does not accumulate in hippocampal CA1 pyramidal neurons immediately after ischemia.

Model Electrochemical-Mass Spectrometric Studies of the Cytochrome P450-Catalyzed Oxidations of Cyclic Tertiary Allylamines

Single-electron transfer and hydrogen atom transfer pathways have been proposed to account for the cytochrome P450-catalyzed alpha-carbon oxidations of amines. With the aid of electrochemistry-electrospray ionization mass spectrometry, the electrochemical potentials required for the one-electron oxidations of N-methyl- and selected N-cyclopropyl-4-phenyl-1,2,3,6-tetrahydropyridinyl derivatives and the chemical fates of the resulting aminyl radical cations have been investigated. Comparison of the results of these studies with those observed in the corresponding enzyme catalyzed oxidations suggests that aminyl radical cations are not obligatory intermediates in the cytochrome P450-catalyzed alpha-carbon oxidations of this class of substrates.

Comparison of metabolic effects of pioglitazone, metformin, and glimepiride over 1 year in Japanese patients with newly diagnosed Type 2 diabetes

AIMS

To compare the metabolic effects of pioglitazone, metformin, and glimepiride in the treatment of Japanese patients with newly diagnosed Type 2 diabetes.

METHODS

A total of 114 patients with Type 2 diabetes who had never used oral hypoglycaemic drugs were studied for 12 months. Patients were randomly assigned to pioglitazone (30-45 mg/day, n = 38), metformin (750 mg/day, n = 39), or glimepiride (1.0-2.0 mg/day, n = 37). The effect of treatment on fasting plasma glucose (FPG), glycated haemoglobin (HbA(1c)), 1,5-anhydroglucitol (1,5AG), total cholesterol, high-density lipoprotein (HDL)-cholesterol, triglycerides, free fatty acids (FFA), and fasting plasma insulin levels was monitored monthly. Body weight and safety data were also collected.

RESULTS

Eight patients withdrew from the study (three in the pioglitazone group, two in the metformin group, and three in the glimepiride group). The rate of reduction of HbA(1c) was fastest in patients receiving glimepiride and slowest in patients receiving pioglitazone. Although there were no significant differences among the three groups in HbA(1c) levels at the end of the study, patients taking pioglitazone had relatively lower FPG and 1,5AG levels than patients taking the other two drugs. These results suggest that pioglitazone acts predominantly on nocturnal metabolism rather than at mealtimes. FFA were reduced significantly in those taking pioglitazone (542.2 microEq/l vs. 237.3 microEq/l; P < 0.01) before a decrease in HbA(1c) was apparent. The change in FFA levels correlated with the change in HbA(1c) (r = 0.409, P < 0.01). There were no significant differences in other lipid parameters among the groups.

CONCLUSIONS

Pioglitazone, metformin, and glimepiride are equally effective in reducing blood glucose in patients with newly diagnosed Type 2 diabetes. However, their specific characteristics, such as the rapid action on blood glucose levels of glimepiride and the favourable action on FPG and FFA of pioglitazone, should be considered when choosing an appropriate agent.

In vitro confirmation of selegiline N-oxidation by flavin-containing monooxygenase in rat microsome using LC-ESI MS

In order to investigate the conversion of selegiline (SG), a drug used in the treatment of Parkinson's disease, to selegiline N-oxide (SGO) as a major metabolic pathway for SG, rat liver microsomal incubations were carried out in vitro in the presence of NADPH. SG was transformed into SGO in vitro as described in our previous human in vivo experiment. In the kinetic studies, the Vmax/Km value of the N-oxidation at pH 8 was found to be approximately four times greater than that at pH 7.4. The N-oxidation was also found to be inhibited by methimazole, an inhibitor of the flavin-containing monooxigenase (FMO) rather than by SKF 525A, an inhibitor of cytochrome P450s, and stimulated approximately two times by n-octylamine, an stimulator of FMO. Moreover, the N-oxidation activity remained almost unchanged in the presence of NADPH even after heating at 50 degrees C for a few minutes. The present data demonstrate that the N-oxidation of SG to SGO is principally mediated by FMO.

Analysis of medium-chain acyl-coenzyme A esters in mouse tissues by liquid chromatography-electrospray ionization mass spectrometry

Medium-chain acyl-coenzyme A (CoA) esters are key metabolites in lipid metabolism. Liquid chromatography-electrospray ionization mass spectrometry analysis of medium-chain acyl-CoA esters is described. Eight medium-chain acyl-CoA esters were well separated on a C(8)-MS reversed-phase column using a linear gradient of ammonium acetate buffer (pH 5.3)-acetonitrile. The positive-ion mass spectra of all the saturated and unsaturated medium-chain acyl-CoA esters gave dominant [M+H](+) ions, whereas their negative-ion mass spectra showed abundant [M-H](-) and [M-2H](2-) ions. The positive-ion mode of operation was slightly less sensitive than the negative-ion detection mode. Five medium-chain acyl-CoA esters of C(6:0), C(8:0), C(8:1), C(10:0), and C(10:1) in liver, heart, kidney, and brain from the mouse were identified. The predominant acyl-CoA peaks were C(6:0), C(8:0), and C(10:0). Small amounts of medium-chain acyl-CoAs of C(8:1) and C(10:1) were detected only in heart and kidney. The analytical method is very useful for the analysis of medium-chain acyl-CoA esters in the tissues.

Decrease in the S1 protein of 30-S ribosomal subunits in polyamine-requiring mutants of Escherichia coli grown in the absence of polyamines

The reason for the decrease of polypeptide-synthetic activity of 30-S ribosomal subunits obtained from two polyamine-requiring mutants of Escherichia coli, grown in the absence of polyamines, has been studied by analyzing the total and split proteins of 30-S subunits by disc gel and slab gel electrophoresis. It was concluded that the decrease of S1 protein in 30-S subunits was responsible for the decrease of polypeptide synthesis in polyamine-requiring mutants of E. coli grown in the absence of polyamines.

Application of liquid chromatography-tandem mass spectrometry for the determination of opioidmimetics in the brain dialysates from rats treated with opioidmimetics intraperitoneally

We have determined three opioidmimetics (compounds I-III) in the rat brain dialysates after intraperitoneal (i.p.) administration of compounds I-III using a liquid chromatography/mass spectrometry with tandem mass spectrometry (LC-MS/MS). The dialysate samples with methanol were directly analyzed by online column-switching liquid chromatography. Using multiple reaction monitoring (MRM, product ions m/z 421 of m/z 657 for compound I, m/z 421 of m/z 643 for compound II, and m/z 407 of m/z 629 for compound III) on LC-MS/MS with electrospray ionization (ESI), opioidmimetics in rat brain dialysates were determined. Calibration curves of the method showed a good linearity in the range of 10-100 ng/ml for each compound. The limit of determination was estimated to be ca. 1 ng/ml for compounds II and III, and ca. 5 ng/ml for compound I, respectively. The precision of analysis showed coefficients of variation ranging from 4.7 to 10.4% at compound III concentration (10-100 ng/ml) in Ringer's solution. As a result, the procedure proved to be very suitable for routine analysis. The method was applied to the analysis of three opioidmimetics in the brain dialysate samples from rats treated with these compounds.

A rat model of neurolathyrism: repeated injection of L-?-ODAP induces the paraparesis of the hind legs

Neurolathyrisim is a motor neuron disease characterized by spastic paraparesis in the hind legs, and is caused by grass pea, Lathyrus sativus, which contains the excitotoxic amino acid, 3-N-oxalyl-L: -2,3-diaminopropanoic acid (L: -beta-ODAP), an alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)-type glutamatergic receptor agonist. In an attempt to make a useful model of this disease, the CNS distribution and toxicity of L: -beta-ODAP was studied in rat neonates after parenteral administration. L: -beta-ODAP was detected in the spinal cord as well as in the pons/medulla oblongata, though only small amounts in the latter. Repeated injection of L: -beta-ODAP resulted in rats with paraparesis of the legs, though at a low incidence rate of 0.032. These paralyzed rats displayed the severe atrophy of the ventral root of the lumbar cord as well as degenerations of motor neuron. The rats were useful models for the study of motor neuron degeneration in the spinal cord.

Crystallization and preliminary X-ray analysis of the primary receptor (PotD) of the polyamine transport system in Escherichia coli

The primary receptor (potD, M(r) = 39 000) of the polyamine transport system in Escherichia coli has been crystallized by the vapor-diffusion method. Two crystal forms were obtained in the presence of spermidine, and were examined by X-ray analysis. Form I crystals, which diffract to 2.5 A resolution, belong to the space group P2(1), with unit-cell dimensions a = 145.3, b = 69.1, c = 72.5 A and beta = 107.6 degrees. Four molecules are contained in an asymmetric unit. These form two dimers that are related to each other by a local translation of about half of the unit cell along the a axis. The two protein molecules in each dimer are similarly related by a local dyad. Form II crystals diffract to 1.8 A resolution and belong to the space group I4(1), with unit-cell dimensions a = b = 130.3 and c = 38.7 A. They contain one molecule per asymmetric unit.

Cyclosporine A and FK506 induce osteoclast apoptosis in mouse bone marrow cell cultures

Studies were carried out to characterize the effects of cyclosporines and FK506 on the formation and survival of osteoclasts deriving from mouse bone marrow cultures. Cyclosporin A (CsA), cyclosporin B (CsB), cyclosporin H (CsH), and FK506 all inhibited receptor activator of NFkappaB ligand (RANKL)-stimulated tartrate-resistant acid phosphatase (TRAP) activity and generation of TRAP+ multinucleated cells in the cultures. CsA and CsG were approximately equipotent, CsH was approximately one order of magnitude less potent than the other cyclosporines, and FK506 was approximately two orders of magnitude more potent than CsA and CsG. All of the inhibitors demonstrated greater potency and efficacy on decreasing the number of TRAP+ multinucleated cells than on decreasing total TRAP activity. Further evidence that late stages were more sensitive to inhibition was obtained in experiments in which CsA was present for different segments of the RANKL-stimulated culture period. CsA was as efficacious when added for the final 2 days of a 4-day culture as when added for the entire culture period, whereas it was less effective if added for only the first 2 days of the culture. When CsA or FK506 were added for 1 day to cultures in which osteoclasts had already formed, the numbers of TRAP+ osteoclasts decreased. Treatment with CsA or FK506 produced nuclear fragmentation and disruption of the multinucleated osteoclasts and an increase in caspase-3 activity. The apoptosis inhibitor z-VAD partially prevented the inhibitory effects of CsA and FK506 on the survival of TRAP+ multinucleated cells in the cultures and also preserved the normal osteoclast morphology. The data indicate that an important component of the inhibitory effects of CsA and FK506 on marrow-derived osteoclasts is the induction of apoptosis.

Potent Estrogenic Metabolites of Bisphenol A and Bisphenol B Formed by Rat Liver S9 Fraction: Their Structures and Estrogenic Potency

We previously demonstrated that the estrogenicity of either bisphenol A [BPA; 2,2-bis(4-hydroxyphenyl)propane] or bisphenol B [BPB; 2,2-bis(4-hydroxyphenyl)butane] was increased several times after incubation with rat liver S9 fraction (Yoshihara et al., 2001). This metabolic activation, requiring both microsomal and cytosolic fractions, was observed with not only rat liver, but also human, monkey, and mouse liver S9 fractions. To characterize the active metabolites of BPA and BPB, we investigated the structures of the isolated active metabolites by negative mode LC/MS/MS and GC/MS. The active metabolite of BPA gave a negative mass peak at [M-H](-) 267 on LC/MS and a single daughter ion at m/z 133 on MS/MS analysis, suggesting an isopropenylphenol dimer structure. Finally, this active metabolite was confirmed to be identical with authentic 4-methyl-2,4-bis(p-hydroxyphenyl)pent-1-ene (MBP) by means of various instrumental analyses. The corresponding peaks of the BPB metabolite were [M-H](-) 295 and m/z 147, respectively, suggesting an isobutenylphenol dimer structure. Further, coincubation of BPA and BPB with rat liver S9 afforded an additional active metabolite(s), which gave a negative mass peak at [M-H](-) 281 and two daughter ion peaks at m/z 133 and m/z 147 on MS/MS analysis. These results strongly suggest that the active metabolite of either BPA or BPB might be formed by recombination of a radical fragment, a one-electron oxidation product of carbon-phenyl bond cleavage. It is noteworthy that the estrogenic activity of MBP, the active metabolite of BPA, is much more potent than that of the parent BPA in several assays, including two reporter assays using a recombinant yeast expressing human estrogen receptor alpha and an MCF-7-transfected firefly luciferase plasmid.

Bone anabolic responses to mechanical load in vitro involve COX-2 and constitutive NOS

Mechanical stimulation is essential for maintaining the homeostasis and architecture of connective tissues including bone. The purpose of our study was to test the importance of several potential signaling intermediates in the anabolic responses of bone to loads applied with a newly developed micromechanical loading device. Tibial bones excised from 7- to 8-day-old CD-1 mice were cyclically loaded at 1 Hz, 1000 muepsilon (microstrain) at a peak load of 100 mN. DNA and protein synthesis were evaluated by measuring the incorporation of 3H-thymidine and 14C-proline, respectively. The roles of cyclooxygenase (COX) isoforms, nitric oxide synthase (NOS) isoforms, and glutamate receptor-gated Ca2+ channeling were examined by incubating the bones in the presence of each of their specific inhibitors. The results indicate that COX-2 and constitutive NOS are important signaling molecules in the anabolic responses of neonatal tibial bone to the micromechanical load in vitro.

Long-term administration of pravastatin reduces serum lipoprotein(a) levels

BACKGROUND

The long-term effect of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors on serum lipoprotein(a) (Lp(a)) levels has been poorly investigated.

OBJECTIVE

This study sought to examine the effect of 24 months' administration of pravastatin on serum Lp(a) levels.

SUBJECTS

23 patients with coronary artery disease and serum low-density lipoprotein (LDL) cholesterol levels of 120 mg/dl or above were included.

METHOD

Serum levels of lipids and Lp(a) were serially determined after the administration of pravastatin for 24 months.

RESULTS

Serum LDL-cholesterol (LDL-C) levels significantly decreased from 1 month after the drug administration and the reduction persisted for 24 months, whereas Lp(a) levels did not decrease at 3 months after the administration but significantly decreased at 12 months or more. The reduction in the Lp(a) levels was not related to the dose of pravastatin.

CONCLUSIONS

The results indicated that long-term administration of pravastatin for 12 months or more significantly reduced serum Lp(a) levels and the reduction of Lp(a) levels occurred much later than that of LDL-C levels. The delayed reduction in serum Lp(a) levels after the administration of pravastatin may be associated with a retarded inhibition of Lp(a) synthesis by the drug.

Determination of cabergoline and L-dopa in human plasma using liquid chromatography-tandem mass spectrometry

We determined cabergoline and L-dopa in human plasma using liquid chromatography-mass spectrometry with tandem mass spectrometry (LC-MS-MS). The deproteinized plasma samples with organic solvent or acid were analyzed directly by reversed-phase liquid chromatography. Using multiple reaction monitoring (MRM, product ions m/z 381 of m/z 452 for cabergoline and m/z 152 of m/z 198 for L-dopa) on LC-MS-MS with electrospray ionization (ESI), cabergoline and L-dopa in human plasma were determined. Calibration curves of the method showed a good linearity in the range 5-250 pg/ml for cabergoline and 1-200 ng/ml for L-dopa, respectively. The limit of determination was estimated to be approximately 2 pg/ml for cabergoline and approximately 0.1 ng/ml for L-dopa, respectively. The method was applied to the analysis of cabergoline and L-dopa in plasma samples from patients treated with these drugs. The precision of analysis showed coefficients of variation ranging from 3.8% to 10.5% at cabergoline concentration of 13.8-26.2 pg/ml and from 2.9% to 8.9% at an L-dopa concentration of 302.5-522.1 ng/ml in patient plasma. As a result, the procedure proved to be very suitable for routine analysis.

pp60c-src activation in lung adenocarcinoma

Nine src family members are known including c-Src, c-Yes, c-Lck, c-Fyn, c-Hck, c-Lyn, c-Blk, c-Fgr and c-Yrk. They encode proteins with molecular weights of 55-62 kilodaltons (kDa), which are either cytoplasmic or membrane-associated protein tyrosine kinases. A close correlation exists between an elevated pp60c-src tyrosine kinase activity and cell transformation. However, the level of activation of pp60c-src in non-small cell lung cancers (NSCLC) remains obscure. The aim of this study was to examine the level of activity of pp60c-src in NSCLC. pp60c-src expression and in vitro protein tyrosine kinase activity in lung cancer tissue samples were measured by western blotting and in vitro kinase assays and compared with those in the surrounding non-tumour lung tissue from the same patient. pp60c-src phosphorylation was assessed by two-dimensional tryptic phosphopeptide mapping. The kinase activity of pp60c-src was significantly activated in NSCLC, especially in adenocarcinomas. In addition, the pp60c-src kinase activity increased with the size of the adenocarcinoma. Two-dimensional tryptic phosphopeptide mapping showed dephosphorylation of pp60c-src at Tyr 530 in adenocarcinomas. The proto-oncogene product, pp60c-src, was activated in NSCLC, especially in adenocarcinomas, in part through the dephosphorylation of Tyr 530. Our results suggest that activation of pp60c-src might play an important role in the progression of lung adenocarcinomas.

Acrolein produced from polyamines as one of the uraemic toxins

It is well known that the addition of spermine or spermidine to culture medium containing ruminant serum inhibits cellular proliferation. This effect is caused by the products of oxidation of polyamines that are generated by serum amine oxidase. Among the products, we found that acrolein is a major toxic compound produced from spermine and spermidine by amine oxidase. We then analysed the level of polyamines (putrescine, spermidine and spermine) and amine oxidase activity in plasma of patients with chronic renal failure. It was found that the levels of putrescine and the amine oxidase activity were increased, whereas spermidine and spermine were decreased in plasma of patients with chronic renal failure. The levels of free and protein-conjugated acrolein were also increased in plasma of patients with chronic renal failure. An increase in putrescine, amine oxidase and acrolein in plasma was observed in all cases such as diabetic nephropathy, chronic glomerulonephritis and nephrosclerosis. These results suggest that acrolein is produced during the early stage of nephritis through kidney damage and also during uraemia through accumulation of polyamines in blood due to the decrease in their excretion into urine.

Diurnal variation in the response of the mandible to orthopedic force

Bone and cartilage metabolism is known to be more active during rest than during periods of activity. The purpose of this study was to examine the hypothesis that mandibular retractive force could be more effective when applied to rats during rest. Mandibular retractive force caused a considerable reduction in the condylar length in experimental groups, and the magnitude of this reduction was greater in the Light-period (08:00-20:00) group than in the Dark-period (20:00-08:00) group. The differentiation and proliferation of chondrocytes were inhibited in animals in the Light-period group, compared with those in the Dark-period group. These results suggest that the orthopedic effects of mandibular retractive force vary depending on the time of day the force is applied, and that such force may be more effective while animals are resting than while they are active.

Alpha-tocopherol transfer protein is specifically localized at the implantation site of pregnant mouse uterus

Alpha-tocopherol transfer protein (alpha-TTP) was first described to play a major role in maintaining alpha-tocopherol levels in plasma, while alpha-tocopherol was primarily reported to be a factor relevant for reproduction. Expression of alpha-TTP is not only seen in the liver, from where it was first isolated, but also in mouse uterus, depending on its state of pregnancy, stressing the importance of alpha-TTP for embryogenesis and fetal development. The cellular localization of alpha-TTP in mouse uterus is reported here. By immunohistochemistry, alpha-TTP could be localized in the secretory columnar epithelial cells of the pregnant uterus on Days 4.5 and 6.5 postcoitum as well as in the glandular epithelial cells and the inner decidual reaction zone surrounding the implantation site. On Days 8.5 and 10.5 postcoitum (midterm of mouse pregnancy), alpha-TTP could still be detected in the uterine secretory columnar epithelial cells, while in alpha-TTP knockout mice, no immunostaining was visible. It is suggested that alpha-TTP plays a major role in supplying the placenta and consecutively the fetus with alpha-tocopherol throughout pregnancy. We conclude that alpha-tocopherol plays a role in the process of implantation and that alpha-TTP may be necessary for adequate alpha-tocopherol status of the fetus.

Estrous-cycle-dependent variation in orthodontic tooth movement

Sex hormones, including estradiol, play important physiological roles in bone metabolism. The purpose of this study was to investigate whether there is estrous-cycle-dependent variation in orthodontic tooth movement, and, if so, to determine the mechanism. Ten-week-old female Wistar rats were used. They received repeated orthodontic force during specific phases in the estrous cycle. Tooth movement in animals that received force principally in estrus was about 33% greater than that in animals that received such force principally in pro-estrus (p < 0.05). Serum estradiol levels also varied according to the estrous cycle, with a peak during pro-estrus and a nadir during estrus, and were inversely related to tooth movement. Furthermore, there were negative correlations between estradiol and both serum TRAP activity and pyridinoline (r = -0.42, p < 0.05; r = -0.59, p < 0.001). These results suggest that cyclic changes in the estradiol level may be associated with the estrous-cycle-dependent variation in tooth movement through its effects on bone resorption.

Primary carcinoid tumor of the liver: report of two cases with an emphasis on US findings

Primary carcinoid tumor of the liver is rare, and its sonographic (US) findings have rarely been reported. We present two histologically proven cases. Both patients were asymptomatic and huge masses, found incidentally by US, were echogenic with many cystic areas. Lesions were markedly hypervascular on color Doppler US and angiography. Thus, primary carcinoid tumor of the liver should be considered when US detects this type of mass in asymptomatic patients.