Urachal remnant diseases: spectrum of CT and US findings

Computed tomography (CT) and ultrasonography (US) are ideally suited for demonstrating urachal remnant diseases. A patent urachus is demonstrated at longitudinal US and occasionally at CT as a tubular connection between the anterosuperior aspect of the bladder and the umbilicus. An umbilical-urachal sinus manifests at US as a thickened tubular structure along the midline below the umbilicus. A vesicourachal diverticulum is usually discovered incidentally at axial CT, appearing as a midline cystic lesion just above the anterosuperior aspect of the bladder. At US, it manifests as an extraluminally protruding, fluid-filled sac that does not communicate with the umbilicus. Urachal cysts manifest at both modalities as a noncommunicating, fluid-filled cavity in the midline lower abdominal wall located just beneath the umbilicus or above the bladder. Both infected urachal cysts and urachal carcinomas commonly display increased echogenicity at US and thick-walled cystic or mixed attenuation at CT, making it difficult to differentiate between them. Percutaneous needle biopsy or fluid aspiration is usually needed for diagnosis and therapeutic planning. Nevertheless, CT and US can help identify most disease entities originating from the urachal remnant in the anterior abdominal wall. Understanding the anatomy and the imaging features of urachal remnant diseases is essential for correct diagnosis and proper management.

A sesquiterpene lactone, costunolide, from Magnolia grandiflora inhibits NF-kappa B by targeting I kappa B phosphorylation

A sesquiterpene lactone, costunolide (CTN), was identified from Magnolia grandiflora together with parthenolide (PTN) by its strong inhibition of LPS-induced NF-kappa B activation. CTN, which showed more potent inhibition than PTN in the NF-kappa B activation, strongly suppressed nitric oxide (NO) production in LPS-stimulated RAW 264.7 cells. RT-PCR and Western blot analyses demonstrated that CTN suppressed the expression of iNOS mRNA and protein in a dose-dependent manner. CTN also significantly inhibited LPS-induced DNA-binding activity of NF-kappa B as well as the LPS-induced degradation of I kappa B-alpha and -beta. Furthermore, CTN inhibited LPS-induced phosphorylation of I kappa B-alpha. These findings support that CTN inhibits NO production by down-regulating iNOS expression, at least, in part through the inhibition of I kappa Bs' phosphorylation and degradation, which are essential for the activation of NF-kappa B.

The effects of dexamethasone on insulin release and biosynthesis are dependent on the dose and duration of treatment

Complex results concerning the effect of glucocorticoids on insulin secretion have been reported. The aim of this study is to clarify the direct effects of glucocorticoids on pancreatic islets and to determine whether the effect of glucocorticoids on insulin biosynthesis or release is dependent on the dose and duration of treatment with glucocorticoid. Studies on insulin secretion and biosynthesis were performed with different concentrations (0, 1, 10, 100 nmol/l) and durations (1 and 6 h) of treatment with dexamethasone (dexa) in rat pancreatic islets. (1) One nmol/l dexa had no inhibitory effect on insulin secretion and biosynthesis. Ten and 100 nmol/l had an inhibitory effect on insulin secretion, which was mainly due to suppression of the first phase of insulin secretion. (2) Insulin content was significantly increased regardless of the concentration in 1-h treated islets. However, insulin content was markedly diminished with 100 nmol/l dexa in 6-h treated islets. (3) The preproinsulin mRNA expression of 6-h treated islets was suppressed in a dose-dependent manner. Our data revealed that, in the condition of short-term and low-dose glucocorticoid exposure, insulin secretion and biosynthesis are not affected. The secretory process of insulin seems to be the initial step of the inhibitory action of glucocorticoid. Both insulin release and biosynthesis are inhibited by chronic exposure to high dose dexamethasone. It can be concluded that glucocorticoid might be involved in the multisteps of insulin release and biosynthesis.

The properties of carbachol-activated nonselective cation channels at the single channel level in guinea pig gastric myocytes

We investigated the properties of carbachol (CCh)-activated nonselective cation channels (NSC(CCh)) at the single channel level in the gastric myocytes of guinea pigs using a magnified whole-cell mode or an outside-out mode. The channel activity (NPo) recorded in a magnified whole-cell mode increased with depolarization (from -120 to -20 mV) and had the half activation potential of -81 mV under the symmetrical 140 mM Cs+ condition. The single channel conductance depended upon the extracellular monovalent cations with the order of Cs+ (35 pS) > Na+ (25 pS) > Li+ (21 pS). The channel activities markedly diminished or disappeared when external Cs+ was replaced with Na+ or N-methyl-D-glucamate (NMDG+). With Cs+ and Na+ as external cations, the channel showed a monotonic increase in NPo with the increased mole fraction of Cs+ over Na+, and it had an intermediate conductance value in solution containing 67% Cs+ with 33% Na+. These data suggested that the extracellular monovalent cations regulate the whole-cell current of NSC(CCh) by modulating both the open state probability and the unitary conductance, and there is one binding site for the extracellular cations within the pore.

Systemic arterial supply to the lungs in adults: spiral CT findings

Systemic arterial supply to the lungs can be congenital or due to acquired disease. Congenital diseases encompass bronchopulmonary sequestration and congenital pulmonary venolobar syndrome, in which the involved lung parenchyma is supplied by the aberrant systemic arteries. An anomalous systemic artery can also supply an area of otherwise normal lung parenchyma. In acquired diseases, hypertrophied normal systemic arteries supply the lungs. Hypertrophied systemic arteries include the bronchial arteries, intercostal arteries, internal mammary arteries, inferior phrenic arteries, branches of the thyrocervical trunk, branches of the hepatic arteries, and branches of the abdominal aorta. Hypertrophy of normal systemic arteries is encountered in patients with bronchiectasis, pulmonary tuberculosis, other pulmonary infections, pulmonary thromboembolism, or chronic obstructive pulmonary disease. These systemic arteries are considered to supply the lungs by means of anastomoses between bronchial and pulmonary arteries within the lung parenchyma or transpleural systemic-pulmonary artery anastomoses. In most cases, the correct diagnosis and treatment plan can be determined by identification of the systemic arteries on computed tomographic scans.

Ligand binding profiles of delta-opioid receptor in human cerebral cortex membranes: evidence of delta-opioid receptor heterogeneity

In this study, receptor binding profiles of opioid ligands for subtypes of opioid delta-receptors were examined employing [3H]D-Pen2,D-Pen5-enkephalin ([3H]DPDPE) and [3H]Ile(5,6)-deltorphin II ([3H]Ile-Delt II) in human cerebral cortex membranes. [3H]DPDPE, a representative ligand for delta1 sites, labeled a single population of binding sites with apparent affinity constant (Kd) of 2.72 +/- 0.21 nM and maximal binding capacity (Bmax) value of 20.78 +/- 3.13 fmol/mg protein. Homologous competition curve of [3H]Ile-Delt II, a representative ligand for delta2 sites, was best fit by the one-site model (Kd = 0.82 +/- 0.07 nM). Bmax value (43.65 +/- 2.41 fmol/mg) for [3H]Ile-Delt II was significantly greater than that for [3H]DPDPE. DPDPE, [D-Ala2,D-Leu5]enkephalin (DADLE) and 7-benzylidenaltrexone (BNTX) were more potent in competing for the binding sites of [3H]DPDPE than for those of [3H]Ile-Delt II. On the other hand, deltorphin II (Delt II), [D-Ser2,Leu5,Thr6]enkephalin (DSLET), naltriben (NTB) and naltrindole (NTI) were found to be equipotent in competing for [3H]DPDPE and [3H]Ile-Delt II binding sites. These results indicate that both subtypes of opioid delta-receptors, delta1 and delta2, exist in human cerebral cortex with different ligand binding profiles.

Association of alpha-2-macroglobulin deletion polymorphism with sporadic Alzheimer's disease in Koreans

Alpha-2-macroglobulin (A2M) deletion polymorphism was recently reported to be associated with Alzheimer's disease (AD) in a way comparable to apolipoprotein E (APOE) polymorphism in a family-based study. However, the association of A2M deletion polymorphism with AD has not been consistently replicated in successive case-controlled studies. In order to evaluate whether this A2M polymorphism is associated with AD in Koreans, we examined the frequencies of the A2M deletion (D) allele and D-bearing genotypes in a group of Koreans composed of 100 sporadic AD patients and 203 control subjects. The frequency of the deletion (D) allele (P=0.046) was significantly different between the total group of AD patients and the controls, although the frequency of the D-bearing genotypes did not attain significance (P=0.078). When the subjects were stratified according to age at onset, there was significant difference in the frequencies of the D allele (P=0.044) and D-bearing genotypes (P=0.041) between late-onset AD patients (> or =65 years) and the controls. However, no significant difference was observed between early-onset AD patients (<65 years) and the control group. Additionally, when we divided the late-onset AD and control subjects by APOE epsilon4 status, the difference of the A2M D allelic frequency was significant only in the APOE epsilon4 negative subjects (P=0.015). In conclusion, our data suggests that the A2M D allele is a modest risk factor for late-onset sporadic AD in Koreans, and the AD risk conferred by the A2M D allele increases in APOE epsilon4 negative subjects.

Novel bile acid derivatives induce apoptosis via a p53-independent pathway in human breast carcinoma cells

We have compared the anti-proliferative effects of ursodeoxycholic acid (UDCA), chenodeoxycholic acid (CDCA) and their derivatives, HS-1183, HS-1199 and HS-1200, on MCF-7 (wild-type p53) and MDA-MB-231 (mutant p53) cells. While UDCA and CDCA exhibited no significant effect, their novel derivatives inhibited the proliferation of both cell lines in a concentration-dependent manner, concomitant with apoptotic nuclear changes and the increase of a sub-G1 population and DNA fragmentation. Furthermore, we also observed an increase in the ratio of pro-apoptotic protein Bax to anti-apoptotic protein Bcl-2 and cleavages of lamin B and poly(ADP-ribose) polymerase (PARP) in MCF-7 and MDA-MB-231 cells. Cell cycle related proteins, cyclin D1 and D3, as well as retinoblastoma protein (pRb) were down-regulated, while the level of cyclin-dependent kinase inhibitor p21(WAF1/CIP1) was increased in both cancer cells after treatment with novel bile acids. These findings suggest that these cytotoxic effects of novel bile acid derivatives on human breast carcinoma cells were mediated via apoptosis through a p53-independent pathway.

Pharmacological effects of naltriben as a ligand for opioid mu and kappa receptors in rat cerebral cortex

Naltriben (NTB) has been used to differentiate the subtypes of delta opioid receptors, delta1 and delta2. However, there is considerable evidence suggesting that NTB may act on other types of opioid receptors too. We examined the effects of NTB on the specific binding of radiolabeled ligands for opioid mu and kappa2 receptors, and the effects on the release of [3H]norepinephrine ([3H]NE) in rat cerebral cortex slices. NTB displaced the specific binding of [3H]DAMGO with Ki value of 19.79 +/- 1.12 nM in rat cortex membranes. Specific binding of [3H]diprenorphine ([3H]DIP) was inhibited by NTB with Ki value of 82.75 +/- 6.32 nM in the presence of DAMGO and DPDPE. High K+ (15 mM)-stimulated release of [3H]NE was attenuated by DAMGO in rat cerebral cortex slices. NTB (30 nM) shifted the dose-response curve of DAMGO to the right and attenuated the maximal effect. In the meantime, NTB inhibited high K+-stimulated [3H]NE release at concentrations above 100 nM. The inhibitory effect of NTB was not attenuated by CTAP (10 nM) and naloxone (3 nM) but by higher concentration of naloxone (30 nM), nor-BNI (300 nM) and bremazocine (3 nM). These results indicate that NTB, depending on the dosage, could acts not only as an antagonist at delta but also as a noncompetitive antagonist for mu receptors, and as an agonist for kappa2 receptors in rat cerebral cortex.

Determination of hypoxic region by hypoxia marker in developing mouse embryos in vivo: a possible signal for vessel development

Hypoxia is a well-known signal for angiogenesis, but the recent proposal that hypoxia exists in developing embryonic tissues and that it induces vascular development remains to be proven. In the present study, we demonstrate the presence of hypoxia in normal developing embryos by means of a hypoxia marker, pimonidazole, and its associated antibody. Our data clearly show that hypoxia marker immunoreactivity was highly detected in developing neural tubes, heart, and intersomitic mesenchyme at an early stage of organogenesis, suggesting that hypoxia may exist in the early stages of embryo development. We also found that hypoxia inducible factor-1alpha (HIF-1alpha) and vascular endothelial growth factor (VEGF) were spatiotemporally co-localized with possible hypoxic regions in embryos. Investigation of platelet endothelial cell adhesion molecule (PECAM) expression provides evidence that endothelial cells proliferate and form the vessels in the hypoxic region in developing organs. Furthermore, we found that hypoxia induced both HIF-1alpha and VEGF in F9 embryonic stem and differentiated cells. Thus, we suggest that hypoxia may exist widely in developing embryonic tissues and that it may act as a signal for embryonic blood vessel formation in vivo.

Latency- and Defense-Related Ultrastructural Characteristics of Apple Fruit Tissues Infected with Botryosphaeria dothidea

ABSTRACT Apple fruit tissues infected with Botryosphaeria dothidea were examined by transmission electron microscopy using susceptible cv. Fuji and resistant cv. Jonathan. Immature (green) and mature (red) fruits of cv. Fuji with restricted or expanding lesions were also examined to reveal subcellular characteristics related with latent and restricted disease development. In infected susceptible mature fruits, cytoplasmic degeneration and organelle disruption commonly occurred, accompanying cell wall dissolution around invading hyphae. Cell wall dissolution around invading hyphae in subepidermis was rare in immature, red halo-symptomed cv. Fuji and resistant cv. Jonathan fruits. In infected immature fruits of cv. Fuji, presumably at the latent state of disease development, cellular degeneration was less severe, and invading hyphae contained prominent microbody-lipid globule complexes or the deposition of thin electron-dense outer layer around cell wall of intercellular hyphae. Both mature fruits with red halos and resistant apple fruits formed cell wall protuberances at the outside of cell walls. In addition, electron-dense extramural layers were formed in the resistant apple fruits. Aberrant hyphal structures such as intrahyphal hyphae were found only in resistant fruit tissues, indicating the physiologically altered fungal growth. These ultrastructural changes of host tissues and fungal hyphae may reflect the pathogenesis of apple white rot under varying conditions of apple fruits.

Cloning and characterization of tissue inhibitor of metalloproteinase-3 (TIMP-3) from shark, Scyliorhinus torazame

We cloned the full-length cDNA encoding TIMP-3 from the cartilage of cloudy dogfish, Scyliorhinus torazame. The entire open reading frame was composed of 645 nucleotides and 214 residues including 12 conserved cysteines and asparagine-184, a putative site for N-linked sugars. It showed about 72% identity to those of other species based on the deduced amino acid sequence. The mRNA of shark TIMP-3 were expressed abundantly in brain and cartilage tissues. To investigate the roles of shark TIMP-3, an expression vector was constructed and transfected into HT1080 human fibrosarcoma cells. Overexpression of shark TIMP-3 reduced the activity of MMP-2 in gelatin zymography. Through human Alu PCR based CAM assay, we also confirmed that shark TIMP-3 transfected HT1080 cells had less intravasation effects.

Inactivation of farnesyltransferase and geranylgeranyltransferase I by caspase-3: cleavage of the common alpha subunit during apoptosis

Caspase plays an important role in apoptosis. We report here that farnesyltransferase/geranylgeranyltransferase (FTase/GGTase)-alpha, a common subunit of FTase (alpha/beta(FTase)) and GGTase I (alpha/beta(GGTase)), was cleaved by caspase-3 during apoptosis. FTase/GGTase-alpha (49 kDa) was cleaved to 35 kDa (p35) in the Rat-2/H-ras, W4 and Rat-1 cells treated with FTase inhibitor (LB42708), anti-Fas antibody and etoposide, respectively. This cleavage was inhibited by caspase-inhibitors (YVAD-cmk, DEVD-cho). Serial N-terminal deletions and site-directed mutagenesis showed that Asp59 of FTase/GGTase-alpha was cleaved by caspase-3. The common FTase/GGTase-alpha subunit, but not the beta subunits, of the FTase or GGTase I protein complexes purified from baculovirus-infected SF-9 cells was cleaved to be inactivated by purified caspase-3. In contrast, FTase mutant protein complex [(D(59)A)alpha/beta(FTase)] was resistant to caspase-3. Expression of either the cleavage product (60-379) or anti-sense of FTase/GGTase-alpha induced cell death in Rat-2/H-ras cells. Furthermore, expression of (D(59)A)FTase/GGTase-alpha mutant significantly desensitized cells to etoposide-induced death. Taken together, we suggest that cleavage of prenyltransferase by caspase contributes to the progression of apoptosis.

Expression of Fas receptor on disc cells in herniated lumbar disc tissue

STUDY DESIGN

The expression of Fas receptor, an apoptosis-related protein, on disc cells was examined in surgically obtained disc specimens.

OBJECTIVE

To assess the fate of disc cells in herniated disc tissue and the difference in the degree of expression of the Fas receptor between contained and noncontained discs.

SUMMARY OF BACKGROUND DATA

Little is known about the fate of disc cells after herniation.

METHODS

Twenty-three herniated lumbar disc specimens were classified into contained discs (protrusion or subligamentous extrusion; n = 9) and noncontained discs (transligamentous extrusion or sequestration; n = 14). All specimens were stained using the avidin-biotin-peroxidase complex method. The percentage of disc cells positive for Fas receptor was calculated and compared with clinical and radiologic data.

RESULTS

There was a significant difference in the percentage of Fas-positive disc cells between the contained and noncontained discs (8.44 vs.- 14.29;P = 0.044). The percentage of Fas-positive disc cells correlated significantly with the patient's age (r = 0.455, P = 0.029), but not with the degree of disc degeneration on magnetic resonance imaging (r = 0.252, P = 0.214).

CONCLUSION

This is the first study to identify the expression of Fas receptor on disc cells in herniated disc tissue. The results show that the disc cells after herniation may undergo Fas-mediated apoptosis and that the degree of expression of Fas receptor differs depending on the type of herniation.

Protein kinase C suppresses spontaneous, transient, outwards K+ currents through modulation of the Na/Ca exchanger in guinea-pig gastric myocytes

The effect of protein kinase C (PKC) on the Ca2+-activated K+ current (IK,Ca) in guinea-pig gastric myocytes was studied using the whole-cell voltage-clamp technique. At a holding potential of 0 mV, IK,Ca, recorded as spontaneous, transient, outwards currents (STOCs), was markedly inhibited, both in mean amplitude (54 +/- 5%) and frequency (60 +/- 8%) by 1 microM phorbol 12, 13 dibutyrate (PDBu, n = 6). These effects were antagonized by pretreatment with 10 nM bisindolylmaleimide I (n = 5), a selective inhibitor of PKC. The possibility that the inhibition of STOCs was due to direct channel inhibition by PKC was addressed using inside-out or open-cell-attached patch-clamp techniques, the latter established using beta-escin. PDBu did not alter the conductance or open probability of the KCa channel in any mode, suggesting that PKC does not inhibit the KCa channel directly. To study the involvement of the Na/Ca exchanger in the inhibition of STOCs by PDBu, its operation was prevented by replacing Na+ in the internal solution by tris(hydroxymethyl)aminomethane (TRIS) and external Na+ by equimolar K+ and Ca2+-activated inwards K+ currents recorded at a holding potential of 0 mV. Neither the mean amplitude (96 +/- 8%) nor the frequency of these currents was inhibited significantly by 1 microM PDBu (n = 5). Like PDBu, 5 microM 2-(2-[4-(4-nitrobenzyloxy)phenyl]ethyl) isothiourea methanesulphonate (KB-R7943), a selective inhibitor of the reverse mode Na/Ca exchanger, also inhibited the mean amplitude (45 +/- 6%) and frequency (26 +/- 2%) of STOCs at the holding potential of 0 mV (n=6). The results suggest that the suppression of STOCs by PKC is mediated by inhibition of the Na/Ca exchanger.

Antiapoptotic role of NF-kappaB in the auto-oxidized dopamine-induced apoptosis of PC12 cells

Current concepts of the pathogenesis of Parkinson's disease (PD) center on the formation of reactive oxygen species (ROS), and dopamine has been considered to be a major source of ROS. Recently, it has been shown in a postmortem study that nuclear translocation of nuclear factor-kappa B (NF-kappaB) was observed in dopaminergic neurons of patient with PD. However, its role is not known. The present study examined the possible role of NF-kappaB in ODA (auto-oxidized dopamine)-induced apoptosis to understand the process of PD. Using the electrophoretic mobility shift assay, it was found that ODA activated the DNA binding activity of NF-kappaB. Suppression of the transcriptional activity of NF-kappaB in PC12 cells by overexpression of a wild-type and a dominant negative mutant form (S32A/S36A) of inhibitor kappa B (IkappaB)-alpha led to increase of apoptotic cell death induced by treatment of ODA. In addition, overexpression of NF-kappaB in PC12 cells blocked ODA-induced cell death. However, JNK/SAPK activities, which mediate various stress signals, were similar among the parental, NF-kappaB- or dominant negative mutant IkappaB alpha-transfected cells. Therefore, these results suggest that activation of NF-kappaB during ODA-induced apoptosis may have a counteracting activity against the signals mediating apoptotic cell death and thereby delay the process of Parkinson's disease.

Routine measurement of serum calcitonin is useful for early detection of medullary thyroid carcinoma in patients with nodular thyroid diseases

BACKGROUND

Medullary thyroid carcinoma (MTC) is characterized by a high concentration of serum calcitonin. Routine measurement of serum calcitonin concentration has been advocated for detection of MTC among patients with nodular thyroid diseases. However, a minimal to moderate increase of serum calcitonin concentration has been frequently observed in diseases other than MTC. Fine-needle aspiration cytology (FNAC) is not a reliable method for detection of MTC. Therefore, we evaluated the usefulness of routine measurement of serum calcitonin concentration in patients with nodular thyroid diseases, and studied the validity of pentagastrin stimulation test and FNAC in these patients.

SUBJECTS AND METHODS

We performed routine measurement of serum calcitonin concentrations in 1,448 patients (male, 285, female, 1,163) with nodular thyroid diseases. The average age was 46 years (range, 14-86 years). Initial examination included thyroid examination, thyroid scan or ultrasonography, measurements of serum free triiodothyronine) (T3), free thyroxine (T4), thyrotropin (TSH) levels, and antithyroid autoantibodies. FNAC was performed in all patients who had palpable or visible thyroid nodule by ultrasonography, and pentagastrin stimulation test was performed in 39 patients who consented. Serum calcitonin concentration was measured with a two-site immunoradiometric assay using commercial kits. We also measured the serum calcitonin concentration in 407 healthy subjects without thyroid or nonthyroid diseases.

RESULTS

Serum calcitonin concentration was 10 pg/mL or less in 403 normal subjects (99.0 percentile), and 11-13 pg/mL in the remaining 4 subjects. We found that 56 (3.87%) of 1,448 patients with nodular thyroid diseases had serum calcitonin level above 10 pg/mL. Ten patients (0.69%) with histologically confirmed MTC were detected by the routine measurement of serum calcitonin. The prevalence of MTC was 5.2% in 194 patients with thyroid carcinoma. Five of 10 patients with MTC had basal serum calcitonin level above 100 pg/mL. The remaining 5 patients had minimal or moderate elevation of basal serum calcitonin (range, 12-86 pg/mL). Serum calcitonin concentration increased to more than 100 pg/mL by pentagastrin in all patients with MTC (2.4- to 37.7-fold increase). FNAC suggested MTC in only 2 patients (22.2%), and failed to diagnose MTC in 7 patients. FNAC was not performed in 1 patient with MTC, because he had no visible mass by ultrasonography.

CONCLUSION

These results suggested that routine measurement of serum calcitonin is useful in the early detection of MTC among patients with nodular thyroid diseases. Pentagastrin stimulation test may also be a reliable way for evaluating thyroid nodular patients with mild or moderate elevation of serum calcitonin concentrations. However, FNAC was not sensitive in detecting MTC. We recommend routine measurement of serum calcitonin concentration in patients with nodular thyroid diseases.

Hypoglycemia-induced VEGF expression is mediated by intracellular Ca2+ and protein kinase C signaling pathway in HepG2 human hepatoblastoma cells

Vascular endothelial growth factor (VEGF) is a potent angiogenic factor that plays a central role in angiogenesis. In this study, we investigated the mechanism of VEGF expression in HepG2 human hepatoblastoma cells under hypoglycemia. The shortage of glucose significantly enhanced VEGF mRNA expression in a time-dependent manner as well as increased DNA-binding activity of AP-1 that plays an important role in VEGF transcription. In addition, treatment of a potent PKC inhibitor, H-7 in glucose-deprived HepG2 cells suppressed hypoglycemia-elevated VEGF expression as well as the increased AP-1 DNA-binding activity. Moreover, we observed that Ca2+ levels remarkably increased under low glucose condition. Consistently, an intracellular Ca2+ chelator, BAPTA/AM significantly decreased hypoglycemia-induced VEGF expression and AP-1 DNA-binding activity. Therefore, these results indicate that increase of intracellular Ca2+ level induces the activation of PKC, which induce the activation of AP-1 leading to the increase of VEGF in glucose-deprived environment. Furthermore, it provides one link in regulation of VEGF with hypoglycemia as well as information to understand how hypoglycemia induces VEGF expression and subsequently leads to tumor angiogenesis.

Renal and pulmonary lymphangioleiomyomatosis: a case report

Lymphangioleiomyomatosis (LAM) is a rare disease that most commonly involves the lung. However, extrapulmonary lymphangioleiomyomatosis rarely occurs with or without subsequent involvement of the lung. We report a case of incidentally found renal and pulmonary lymphangioleiomyomatosis in a patient who had no stigmata of tuberous sclerosis.

Toxic amebic colitis coexisting with intestinal tuberculosis

A patient with a fulminant amebic colitis coexisting with intestinal tuberculosis had a sudden onset of crampy abdominal pain, mucoid diarrhea, anorexia, fever and vomiting with signs of positive peritoneal irritation. Fulminant amebic colitis occurring together with intestinal tuberculosis is an uncommon event and may present an interesting patho-etiological relationship. The diagnosis was proven by histopathologic examination of resected specimen. Subtotal colectomy including segmental resection of ileum, about 80 cm in length, followed by exteriorization of both ends, was performed in an emergency basis. Despite all measures, the patient died on the sixth postoperative day. The exact relationship of fulminant amebic colitis and intestinal tuberculosis is speculative but the possibility of a cause and effect relationship exists. Fulminant amebic colitis may readily be confused with other types of inflammatory bowel disease, such as idiopathic ulcerative colitis, Crohn's disease, perforated diverticulitis and appendicitis with perforation. This report draws attention to the resurgence of tuberculosis and amebiasis in Korea, and the need for the high degree of caution required to detect it.

Nontumorous hepatic arterial-portal venous shunts: MR imaging findings

PURPOSE

To determine the magnetic resonance (MR) imaging findings of small nontumorous hepatic arterial-portal venous (arterioportal) shunts in the liver.

MATERIALS AND METHODS

MR images in 25 patients with 38 small nontumorous arterioportal shunts verified with surgery or follow-up imaging were included in this study. The causes of arterioportal shunts were iatrogenic causes in 11 patients and/or cirrhotic changes in the remaining patients. Nonenhanced T1- and T2-weighted images and multiphase contrast material-enhanced dynamic images were retrospectively reviewed and compared with conventional hepatic arteriograms to determine the MR characteristics related to the focal hemodynamic changes.

RESULTS

On arterial-dominant-phase dynamic MR images, 29 (76%) of the 38 arteriographically suggested nontumorous arterioportal shunts displayed abnormal findings distinguished against the surrounding hepatic parenchyma, including wedge-shaped (n = 14), nodular (n = 9), or irregularly outlined (n = 6) areas of focal contrast enhancement. The signal intensity on nonenhanced T1- and T2-weighted images of the corresponding areas appeared unremarkable except for three wedge-shaped high-signal-intensity areas (three [8%] of 38) on T2-weighted images accompanied by prolonged contrast enhancement. Most (24 [83%] of 29) areas of abnormal signal intensity were located at the periphery of the liver parenchyma.

CONCLUSION

A small nontumorous arterioportal shunt should be considered one of the causes of focal parenchymal hyperperfusion abnormalities on contrast-enhanced dynamic MR images of the liver in the absence of abnormal signal intensity on static MR images.

Background nonselective cationic current and the resting membrane potential in rabbit aorta endothelial cells

The ion channel conductances that regulate the membrane potential was investigated by using a perforated patch-clamp technique in rabbit aorta endothelial cells (RAECs). The whole-cell current/voltage (I-V) relation showed a slight outward rectification under physiological ionic conditions. The resting membrane potential was -23.3 +/- 1.1 mV (mean +/- SEM, n = 19). The slope conductances at the potentials of -80 and 50 mV were 31.0 +/- 4.0 and 62.8 +/- 7.1 pS pF(-1), respectively (n = 15). Changes in the extracellular and intracellular Cl(-) concentrations did not affect the reversal potential on I-V curves. The background nonselective cationic (NSC) current was isolated after the K(+) current was suppressed. The relative permeabilities calculated from the changes in reversal potentials using the constant-field theory were P(K):P(Cs):P(Na):P(Li) = 1:0.87:0.40:0.27 and P(Cs):P(Ca) = 1:0.21. Increases in the external Ca(2+) decreased the background NSC current in a dose-dependent manner. The concentration for half block by Ca(2+) was 1.1 +/- 0.3 mM (n = 7). Through the continuous recording of the membrane potential in a current-clamp mode, it was found that the background NSC conductance is the major determinant of resting membrane potential. Taken together, it could be concluded that the background NSC channels function as the major determinant for the resting membrane potential and can be responsible for the background Ca(2+) entry pathway in freshly isolated RAECs.

Insulin-like growth factor II induces interleukin-6 expression via NFkappaB activation in psoriasis

IGF-II is known to induce the growth of keratinocytes and the level was significantly elevated in the tissue fluid of psoriatic lesion. However, the role of IGF-II in psoriasis is not well defined. Because an inflammatory cytokine, interleukin-6 (IL-6) is overexpressed in psoriatic lesions, we explored whether IGF-II has some role in psoriasis through induction of IL-6. Therefore, the expression of IL-6 was analyzed after treatment of IGF-II in primary cultured psoriatic cells and human keratinocyte cell line, HaCaT. We found that IGF-II induced the IL-6 mRNA expression significantly. To investigate the inducing mechanism of IL-6 by IGF-II, we examined the promoter activity of IL-6 and the DNA binding activity of NFkappaB, a strong regulator of IL-6. Interestingly, IL-6 promoter activity and the binding activity of NFkappaB were remarkably increased by IGF-II. Western blot data that IkappaB was reduced by IGF-II significantly suggest that NFkappaB activation by IGF-II may be mediated through the downregulation of IkappaB. Therefore, these results suggest a novel role of IGF-II in psoriasis possibly by inducing IL-6 through the activation of NFkappaB mediated by downregulation of IkappaB.