Effect of mechanical strain on gastric cellular migration and proliferation during mucosal healing: role of Rho dependent and Rac dependent cytoskeletal reorganisation

BACKGROUND

Various factors affect gastric wound healing. The influence of physical stimulation on gastric mucosal cells during the process of gastric wound healing is not completely understood.

AIMS

To assess the role of a physical stimulant, in this case mechanical strain, on gastric mucosal restoration.

METHODS

Mechanical strain was applied to adherent rat gastric mucosal cells (RGM1) cultured confluently on collagen type I coated silicone elastomer membrane in order to increase the dimension by an average of 5% and 10% at 5 cycles/minute for 72 hours after wounding. Repair of the wound was monitored every 12 hours for up to 72 hours using an inverted phase contrast microscope. Cell proliferation was detected using 5-bromodeoxyuridine staining. The cytoskeletal protein actin, a component of focal adhesion plaque protein, vinculin, and the small GTP-binding proteins RhoA and Rac1 were detected by immunohistochemistry in the cells located at the margin of and remote from the wound.

RESULTS

The cells located at the margin of the wound showed the greatest migration and proliferation and were found to express more rudimentary lamellipodia and filopodia in the absence of mechanical strain. Vinculin, RhoA, and Rac1 were also strongly expressed in the wound margin. Under conditions of mechanical strain, the speed of migration of cells slowed and fewer proliferating cells were detected around the wound in a strain strength dependent manner. Lamellipodial formation, vinculin, RhoA, and Rac1 were poorly expressed in the same area. However, in cells located more than 1 mm from the wound edge, cytoskeletal rearrangement, and the expression of vinculin, RhoA, and Rac1 were not influenced by mechanical strain.

CONCLUSIONS

Migration and proliferation of RGM1 cells in culture during wound healing were inhibited by mechanical strain, which caused dysfunction of the cytoskeletal and cell adhesion systems. It is suggested that physical stimulants such as mechanical strain may play a role in gastric wound healing in vivo by modifying cellular migration and proliferation.

Tin speciation in the femtogram range in open ocean seawater by gas chromatography/inductively coupled plasma mass spectrometry using a shield torch at normal plasma conditions

A sensitive method for the determination of ultratrace organotin species in seawater is described. The merits and demerits of derivatization methods using Grignard reagent or sodium tetraethylborate (NaBEt4) were evaluated in terms of derivatization efficiency, applicability to the programmed temperature vaporization (PTV) method, and procedural blanks. The sensitivity of the gas chromatography/inductively coupled plasma mass spectrometry (GC/ICPMS) was improved by more than 100-fold by operating the shield torch at normal plasma conditions, compared with that obtained without using it. The absolute detection limit as tin reached subfemtogram (fg) levels. Furthermore, the detection limit in terms of relative concentration was improved 100-fold by using the PTV method, which enabled the injection of a large sample volume of as much as 100 microL without loss of analyte. When the organotin species in seawater were extracted into hexane with a preconcentration factor of 1000 after ethylation with NaBEt4 and a 100 microL aliquot of the extract was injected into the GC, the instrumental detection limit in relative concentration reached 0.01 pg/L in original seawater. Sources of contamination of organotin species during the sample preparation were examined, and a purification method of NaBEt4 was developed. Finally, the method was successfully applied to open ocean seawater samples containing organotin species at the level of 1-100 pg/L.

Difference in security of stent jail between Palmaz-Schatz, NIR, and Multi-Link stents: the effect of balloon inflation through stent struts

After placing a stent in the main vessel of a bifurcation lesion, it is often necessary to perform further balloon inflation or stent placement through the stent struts in order to treat a lesion of the secondary vessel or side branch. This balloon inflation with dilatation through the cells of the stent in the main vessel results in stent strut disfigurement. This disfigurement causes various degrees of stenosis within the main vessel secondary to stent strut deformity. The degree of strut deformity, and therefore stenosis, may vary significantly depending on stent design and structure. A model of a bifurcation lesion with an angle of 45 degrees was created from acrylic resin. The diameters of the main vessel and the secondary vessel were both 3.5 mm. Deployment of the Palmaz-Schatz stent (PS, n = 5), NIR stent (n = 5), or Multi-Link stent (n = 5) was performed in the main vessel with a 3.5-mm balloon catheter inflated to 6 atm. A second 3.5-mm balloon catheter was then inflated to 6 atm through the stent struts of the main vessel and into the ostium of the secondary vessel. The minimal lumen diameter (MLD) and cross-sectional area (CSA) at the ostium of the side branch and the stenosis within the main vessel were then measured, taking into account the stent deformity that occurred. Kissing balloon dilatation with two 3.5-mm balloon catheters was then performed and the stenosis secondary to stent deformity in the main vessel was remeasured. The MLD of the Multi-Link stent at the side-branch ostium was greater compared with those of the Palmaz-Schatz stent or the NIR stent (2.4 +/- 0.1, 1.6 +/- 0.1, 1.7 +/- 0.1 mm, P < 0.01) and CSA (4.9 +/- 0.5, 2.7 +/- 0.3, 2.5 +/- 0.3 mm(2), P < 0.01). Balloon inflation through the stent struts caused stent deformity that resulted in some degree of stenosis within the stent of the main vessel in all three stent types. Kissing balloon inflation reduced, but never eliminated, this stenosis. The percent stenosis in the main vessel secondary to stent deformity (PS 34% +/- 9%, NIR 25% +/- 8%, Multi-Link 34% +/- 7%, NS) and residual stenosis postkissing balloon inflation (PS 12% +/- 1%, NIR 10% +/- 3%, Multi-Link 14% +/- 3%, NS) were not significantly different among these three stents. At the side-branch ostium, the MLD and CSA were significantly greater for the Multi-Link stent compared with those of the Palmaz-Schatz or NIR stent. Balloon inflation through the stent struts caused stent deformity that resulted in stenosis within the stent in the main vessel. Kissing balloon inflation reduced this stenosis, but some residual stenosis always remained. The stenoses within the main vessel did not differ among the three stent types. Cathet. Cardiovasc. Intervent. 48:230-234, 1999.

Detection of IgA, IgM, and IgG subclasses of anti-M2 antibody by immunoblotting in autoimmune cholangitis: is autoimmune cholangitis an early stage of primary biliary cirrhosis?

Autoimmune cholangitis (AIC) has been proposed as a distinct disease entity from primary biliary cirrhosis (PBC), without antimitochondrial antibody (AMA) and anti-M2 antibody but with a high titer of antinuclear antibody (ANA) in the serum. However, negativity for AMA and anti-M2 antibody was determined by different methods in different studies. We hypothesized that anti-M2 antibody negativity in AIC resulted from methodological differences, including selection of the immunoglobulin subclass of the autoantibody. Twenty-three patients compatible with AIC whose serum tested negative for AMA and positive for ANA (> or = 1:80) were compared with 71 AMA-positive PBC patients. Laboratory findings, histology, and the pattern of anti-M2 antibody assessed by immunoblotting were compared. Alkaline phosphatase, total bilirubin, total cholesterol, and IgM values were lower in patients with AIC (P < 0.05, 0.01, respectively). Anti-smooth muscle antibody was detected more frequently in patients with AIC (P < 0.01). However, anti-M2 antibody was detected using immunoblotting not only in PBC but also in AIC cases. IgA class alone, IgM class alone, or both IgA and IgM classes of anti-M2 antibody were detected in 13%, 17%, and 22% of AIC patients, respectively, whereas they were not detected in PBC patients (P < 0.05, P < 0.01, P < 0.01). IgG class anti-M2 was detected in all patients with PBC, whereas it was detected in 48% of patients with AIC (P < 0.01). Histological evaluation showed that the early stages of disease were found more frequently in AIC (78%) than in PBC patients (39%) (P < 0.01). Anti-M2 antibody was detected by immunoblotting in all AIC patients. Hence, AIC is not a distinct disease from PBC. For diagnosing AIC and/or PBC, anti-M2 antibody should be examined by the immunoblotting assay to detect not only IgG but also IgA and IgM subclasses.

[Glibenclamide inhibits cholesterol metabolism in macrophage]

Sulfonylureas are generally used in the therapeutic treatment of non-insulin-dependent diabetes mellitus. Little is known, however, whether they also affect the lipid metabolism. Using glibenclamide (GB), a typical sulfonylurea, we have investigated its effects on the lipid metabolism in macrophages, J774 and phorbol ester-treated THP-1 cells. In the whole-cell assay system for cholesteryl ester (CE) accumulation that is induced by addition of chemically modified low-density lipoprotein (LDL), such as Ac-LDL and ox-LDL, GB effectively inhibited the CE accumulation of J774 cells in dose-dependent manners. The inhibition was resulted from increase in free cholesterol but not from change in total cholesterol amount. The results suggest that GB acts on acyl-CoA: cholesterol acyltransferase (ACAT) and inhibits its activity. To confirm the possibility, we then tested GB by another assay system using ACAT that was solubilized from the cells and reconstituted into the liposome composed of phosphatidyl choline- cholesterol. GB inhibition was not so much effective as those by CI-976 and NTE-122, known ACAT inhibitors, but the inhibition was complete in the presence of 100 microM GB. Using cell homogenates of PMA-stimulated THP-1 cells, GB also inhibited the ACAT activity to the level of undifferentiated THP-1 cells. These results indicate that GB acts as ACAT inhibitor but the chemical structure is quite different from the conventional ACAT inhibitors, suggesting it can be a seed to generate potential ACAT inhibitors which do not exhibit toxicity in adrenal gland.

Tumor necrosis factor-alpha and interferon-gamma suppress both gene expression and deoxyribonucleic acid-binding of TTF-2 in FRTL-5 cells

Tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) are cytokines that can individually or additively suppress thyroid cell function and the expression of thyroid-specific genes, such as thyroglobulin (TG) and thyroperoxidase (TPO). Thyroid transcription factor-2 (TTF-2) is a DNA-binding protein that modulates the expression of TG and TPO genes. In the present study, we examine the effects of TNF-alpha and IFN-gamma on TTF-2 gene expression, as well as the DNA-binding activity of TTF-2. FRTL-5 cells were maintained in 5H medium containing 0.2% calf serum for 7 days, then incubated with TNF-alpha, IFN-gamma, or TNF-alpha plus IFN-gamma. Total RNA was isolated and Northern blotted. TNF-alpha (50 ng/ml) only slightly suppressed (61+/-2% compared with control), whereas IFN-gamma (100 U/ml) modestly decreased TTF-2 messenger RNA (mRNA) levels (34+/-4%). TNF-alpha and IFN-gamma simultaneously caused a marked decrease in TTF-2 mRNA levels (13+/-2%). The suppressive effects of TNF-alpha and IFN-gamma on TTF-2 mRNA levels were concentration dependent and maximal at 50 ng/ml TNF-alpha with 100 U/ml IFN-gamma. The suppressive effect was also time dependent, reaching a maximum 12 h after exposure. Moreover, the suppressive effects of TNF-alpha and IFN-gamma upon rat TG and TTF-2 mRNA levels were similar. To test whether TNF-alpha and IFN-gamma alter TTF-2-binding to DNA, we performed electrophoretic mobility shift assays using a TTF-2-binding element in the rat TG gene as a probe. Formation of the TTF-2/DNA complex was decreased by TNF-alpha and/or IFN-gamma. Our results demonstrate that TNF-alpha and IFN-gamma additively reduce the gene expression and DNA-binding of TTF-2. These data suggest that TTF-2 is involved in the TNF-alpha and IFN-gamma-induced suppression of thyroid-specific gene expression.

Enhanced amyloidogenicity of sulfonated transthyretin in vitro, a hypothetical etiology of senile amyloidosis

Genetic variants of transthyretin (TTR) cause systemic amyloidosis and wild-type TTR may also in some situations produce amyloid fibrils. We have analyzed wild-type and variant TTRs by mass spectrometry and found that TTR preparations from all individuals demonstrated free TTR, TTR conjugated with thiol compounds and several minor components. We previously described a component which had a molecular mass 80 Da larger than free TTR and was proved to be TTR conjugated with sulfite. Here, the amyloid fibril formation of the TTR isoforms was monitored by the turbidity at 330 nm, and by a Congo red-binding assay as a function of pH, according to the method of Lai et al. The S-sulfonated TTR showed the highest level of amyloid fibril formation. In contrast, TTR reduced by dithiothreitol, which was free of the S-sulfonated component, showed neither elevation of the turbidity nor the Congo red binding. Commercially purchased TTR without further treatment containing free, S-sulfonated and other species of TTR molecules showed an intermediate elevation. These results suggested that the S-sulfonated wild-type TTR is highly amyloidogenic. Although further experiments are needed to apply the observation to in vivo phenomenon, exogenous sulfite may be a cause of senile systemic amyloidosis.

Insulin resistance and classic risk factors in type 2 diabetic patients with different subtypes of ischemic stroke

OBJECTIVE

In addition to classic risk factors (e.g., hypertension), insulin resistance is an important risk factor for the development of atherosclerosis. To investigate the risk factors for ischemic stroke in type 2 diabetes, we measured insulin sensitivity and several risk factors in 94 Japanese type 2 diabetic patients with different types of stroke.

RESEARCH DESIGN AND METHODS

Stroke was classified by magnetic resonance imaging (MRI) and magnetic resonance (MR) angiography into the following subtypes: 1) patients with normal MRI and MR angiography (NOR; n = 30), 2) patients with lacunar infarction (LAC; n = 28), 3) patients with atherothrombotic infarction (ATI; n = 22), and 4) patients with large-artery atherosclerosis (LAA; n = 14). Insulin sensitivity was assessed by the K index of the insulin tolerance test (KITT).

RESULTS

Patients with LAC, ATI, and LAA were significantly older and were more likely to be hypertensive than patients with NOR. Significantly higher insulin resistance was observed in patients with LAC, ATI, and LAA than in patients with NOR (KITT 2.21 +/- 0.17, 2.10 +/- 0.17, 2.19 +/- 0.25, and 3.25 +/- 0.21% per min, respectively, P < 0.001). Adjustment for age, sex, BMI, and duration of diabetes did not influence this result. Multiple logistical regression analysis showed that insulin resistance was an independent risk factor for all subtypes of ischemic stroke in type 2 diabetic patients. The same analysis showed that a high pulse pressure was a risk factor for LAC, postprandial C-peptide (hyperinsulinemia) was a risk factor for ATI, and longstanding hyperglycemia was a risk factor for LAA.

Effects of Anions on Local Structure of Al and Si in Aluminosilicates

Three kinds of amorphous aluminosilicates were synthesized by coprecipitation of silicic acid with aluminum hydroxide in the presence of different inorganic ions: sulfate, chloride, and nitrate. Although the bulk composition of the aluminosilicates obtained was not affected by anion species, their DTA spectra were significantly different, suggesting that their structures also differ. The local structure of Al and Si in the aluminosilicates was studied in detail by 27Al and 29Si MAS NMR. From the 27Al MAS NMR spectra and comparison between 29Si HD- and CP-MAS NMR spectra, it was concluded that the aluminosilicate obtained in the presence of sulfate ions has only a montmorillonite-like structure, whereas in the cases of chloride and nitrate, the solids are composed of three phases: aluminum hydroxide, silica, and the montmorillonite-like aluminosilicate. The difference in the local structure of Al and Si in the aluminosilicates was explained by the difference in interaction between the anions and aluminum ions. Copyright 1999 Academic Press.

A novel method for indexing echocardiographic left ventricular mass in infants, children and adolescents: evaluation of obesity-induced left ventricular hypertrophy

BACKGROUND

Measurement of left ventricular mass (LVM) is important to the diagnosis of left ventricular hypertrophy in children with various cardiovascular diseases. The purpose of this study was to determine the most appropriate method for standardization of LVM and to evaluate obesity-induced left ventricular hypertrophy in children across the entire age range, from infancy through adolescence.

METHODS

We studied 928 children and adolescents (527 males, 401 females), aged 0-17 years, who were classified into two groups by degree of obesity. Left ventricular mass was calculated by M-mode echocardiography using the formula of Devereux et al. and was indexed using body size (body length, bodyweight or body surface area) raised to a non-integer power using logarithmic transformation of measurements in children without obesity.

RESULTS

The body length, bodyweight and body surface area exponents were 1.85, 0.88 and 1.15, respectively, in males, and 1.72, 0.82 and 1.08, respectively, in females. Whereas indexing of left ventricular mass by body length both in males and in females revealed significant differences between the two groups, indexing using bodyweight or body surface area exponents did not manifest left ventricular hypertrophy induced by obesity.

CONCLUSION

It is suggested that applying body length exponents 1.85 in males and 1.72 in females is an appropriate method for indexation of LVM in children and adolescents. This method is particularly useful for the evaluation of left ventricular hypertrophy in children.

A simple and reliable method of detecting variant transthyretins by multidimensional liquid chromatography coupled to electrospray ionization mass spectrometry

Transthyretin (TTR) variants cause amyloidosis. A method, originally reported by us, of detecting the variants by high performance liquid chromatography/electrospray ionization mass spectrometry (ESIMS) using materials precipitated with anti-TTR antiserum, has been successfully applied by several institutions. The method is simple and reliable, but some variants may not precipitate with the antiserum or may precipitate in different yields compared to normal TTR. Moreover, unidentified minor peaks were observed, which may have been derived from cross reactive materials. We have now devised a new procedure to overcome these problems. An anion exchange and reversed phase liquid chromatography system and ESI mass spectrometer were connected in a tandem fashion using a 6 port valve and a protein trap cartridge. The profile of ion peaks by the method was the same as that by MS with immunoprecipitates. The minor peaks were proved not to be derived from cross reactive materials, and the molecular species of these peaks were characterized. This method is faster than immunoprecipitation method and using no antibody is a great benefit. The method can be applied widely to the study various proteins, when antibodies are not available.

Effect of a novel prolyl endopeptidase inhibitor, JTP-4819, on spatial memory and on cholinergic and peptidergic neurons in rats with ibotenate-induced lesions of the nucleus basalis magnocellularis

We conducted behavioral and neurochemical studies of a novel prolyl endopeptidase inhibitor, (S)2-[[(S)-2-(hydroxyacetyl)-1pyrrolidinyl]carbonyl]-N-(phenylmeth yl)-1-pyrrolidine-carboxamide (JTP-4819), in rats with lesions of the nucleus basalis magnocellularis (NBM-lesioned rats) induced by ibotenate. Administration of JTP-4819 (1 and 3 mg/kg, p.o.), on and after the 8th day, significantly shortened the escape latency in the Morris water maze as compared to the vehicle-treated group. JTP-4819 also significantly increased the path length in the quadrant with the platform removed in the spatial probe trial. Neurochemical studies of brains removed after the Morris water maze task showed that choline acetyltransferase activity in the cerebral cortex, but not the hippocampus, was significantly reduced by NBM lesioning, while there were no changes of muscarinic M1 receptor binding activity detected using [3H]pirenzepine. JTP-4819 had almost no effect on these cholinergic parameters in NBM-lesioned rats. Substance P-like immunoreactivity (LI), thyrotropin-releasing hormone (TRH)-LI, and arginine-vasopressin-LI were not significantly changed in the cerebral cortex and hippocampus of NBM-lesioned rats as compared to sham-operated rats. However, these neuropeptide levels were significantly increased in both brain regions by repeated administration of JTP-4819 (1, 3 and/or 10 mg/kg, p.o.). These results suggest that JTP-4819 ameliorated memory impairment due to NBM lesioning by potentiating SP, TRH and AVPergic neurons secondary to PEP inhibition.

A neurotrophic pyrimidine compound, MS-818, enhances EGF-induced restoration of gastric epithelial wounds in vitro

MS-818 is a novel synthetic pyrimidine compound that stimulates nerve regeneration and promotes synthesis of various growth factors and differentiation of astrocytes. Effects of MS-818 on gastric epithelial cells were assessed using a wound repair model with primary cultured gastric epithelial cells from rabbits. A round wound with a constant cell-free area was created and the process of restoration was monitored by measuring wound size every 12 h. Cell proliferation was monitored by sequential staining with BrdU. As previously reported, EGF (10 ng/ml) accelerated wound repair by promoting cell migration and proliferation. Although MS-818 alone had no effects, MS-818 (10-100 microM) enhanced EGF-induced acceleration of gastric epithelial restoration, including cell migration and proliferation. Although the detailed mechanism of action of this agent is still unclear, MS-818 might have favorable effects on in vivo gastric mucosal repair.

Induction of murine macrophage growth by oxidized low density lipoprotein is mediated by granulocyte macrophage colony-stimulating factor

We have examined whether certain secreted factor(s) is involved in oxidized low density lipoprotein (Ox-LDL)-induced murine macrophage growth. An antibody against granulocyte-macrophage colony-stimulating factor (GM-CSF) effectively inhibited Ox-LDL-induced macrophage growth by >80%. Ox-LDL as well as phospholipase A2-treated acetylated LDL enhanced mRNA levels and protein release of GM-CSF from macrophages, while neither acetylated LDL nor lysophosphatidylcholine (lyso-PC) showed such effects. The maximal induction of GM-CSF by Ox-LDL was noted at 4 h, followed by a time-dependent decrease to a basal level within 24 h. Ox-LDL-induced macrophage growth was inhibited by 75% by replacement of the culture medium at 24 h by a fresh medium containing the same concentration of Ox-LDL, when GM-CSF had already returned to the basal level. Thus, a cytokine(s) other than GM-CSF is also expected to participate in Ox-LDL-induced macrophage growth in a later phase. The Ox-LDL-induced GM-CSF release was inhibited by calphostin C, a protein kinase C inhibitor, and was significantly reduced in macrophages from the knockout mice lacking class A, type I and type II macrophage scavenger receptors (MSR-AI/AII). These results taken together indicate that effective endocytosis of lyso-PC of Ox-LDL by macrophages through MSR-AI/AII and subsequent protein kinase C activation have led to GM-CSF release into the medium which may play a priming role in conjunction with other cytokines in Ox-LDL-induced macrophage growth.

Analysis of differentiation-induced expression mechanisms of thyrotropin receptor gene in adipocytes

Rat adipose tissue, as well as differentiated 3T3-L1 cells, has been shown to express TSH receptor (TSHR) mRNA in amounts approaching those in the thyroid. We investigated the molecular mechanisms of TSHR gene expression in adipose cells. Primer extension and cloned cDNA sequences showed that transcription of the TSHR gene in rat adipose tissue was from multiple start sites clustered between -89 to -68 bp and almost identical to those in FRTL-5 thyroid cells. By transient expression analysis, we localized, between -146 and -90 bp, a positive regulatory element, the activity of which was markedly increased after the differentiation of 3T3-L1 cells. Deoxyribonuclease I protection showed that nuclear extracts from differentiated 3T3-L1 cells strongly protected two sequences, from -146 to -127 bp, including a cAMP response element-like sequence and from -112 to -106 bp containing a putative Ets-binding sequence. In differentiated 3T3-L1 cells, disruption or deletion of either sequence was found to result in the loss of enhancer activity, suggesting both elements may synergistically activate the TSHR promoter. Electrophoretic mobility shift analysis revealed the induction of new protein/DNA complexes formed either with the cAMP response element-like site or with putative Ets elements after the differentiation into adipocytes. In contrast, nuclear proteins, whose binding to DNA was diminished after the differentiation of 3T3-L1 cells, were found to interact with the site contiguous to the 5'-end of the putative Ets-binding sequence. Mutations of this binding site, which reduced the protein/DNA complex formation, increased TSHR promoter activity in undifferentiated cells. These observations suggested that differentiation-induced diminution of suppressor interactions may allow the enhancers to synergistically activate the transcription of TSHR gene in adipocytes.

[Evaluation of anomalous bile ducts using helical CT cholangiography]

PURPOSE

To evaluate the usefulness of helical CT cholangiography (DIC-CT) for laparoscopic cholecystectomy.

MATERIAL AND METHODS

Prior to laparoscopic cholecystectomy, 151 patients were examined by DIC-CT. DIC-CT was performed 30 minutes after drip infusion of 100 ml of Iotroxic acid meglumine. Two-dimensional axial (2D) images with 2.5 mm or 1.5 mm slice thickness were reformatted from the raw data, and three-dimensional (3D) images were reconstructed using the surface reconstruction method. Two- and three-dimensional images were compared with the operative cholangiograms in all subjects.

RESULTS

DIC-CT images of 16 cases of aberrant bile duct (10.6%) and 4 cases of anomalous junction of the cystic duct (2.6%) corresponded to the operative cholangiogram. In one case of an aberrant posterior bile duct, which drained into the common bile duct more proximally to the papilla Vater than the cystic duct did, it was difficult to diagnose correctly the anomalous junction of the bile duct on 2D images but easy on 3D images. Although another case was misdiagnosed to have double cystic ducts on 3D images, the 2D images and operative cholangiogram showed normal junction of a cystic duct.

CONCLUSION

Both 2D and 3D images were useful and necessary in the evaluation of anomalous bile ducts before laparoscopic cholecystectomy.

Expression of ACAT-1 protein in human atherosclerotic lesions and cultured human monocytes-macrophages

The acyl coenzyme A:cholesterol acyltransferase (ACAT) gene was first cloned in 1993 (Chang et al, J Biol Chem. 1993;268:20747-20755; designated ACAT-1). Using affinity-purified antibodies raised against the N-terminal portion of human ACAT-1 protein, we performed immunohistochemical localization studies and showed that the ACAT-1 protein was highly expressed in atherosclerotic lesions of the human aorta. We also performed cell-specific localization studies using double immunostaining and showed that ACAT-1 was predominantly expressed in macrophages but not in smooth muscle cells. We then used a cell culture system in vitro to monitor the ACAT-1 expression in differentiating monocytes-macrophages. The ACAT-1 protein content increased by up to 10-fold when monocytes spontaneously differentiated into macrophages. This increase occurred within the first 2 days of culturing the monocytes and reached a plateau level within 4 days of culturing, indicating that the increase in ACAT-1 protein content is an early event during the monocyte differentiation process. The ACAT-1 protein expressed in the differentiating monocytes-macrophages was shown to be active by enzyme assay in vitro. The high levels of ACAT-1 present in macrophages maintained in culture can explain the high ACAT-1 contents found in atherosclerotic lesions. Our results thus support the idea that ACAT-1 plays an important role in differentiating monocytes and in forming macrophage foam cells during the development of human atherosclerosis.

The very low- and intermediate-density lipoprotein fraction isolated from apolipoprotein E-knockout mice transforms macrophages to foam cells through an apolipoprotein E-independent pathway

Apolipoprotein E (apoE)-knockout mice develop severe atherosclerosis associated with high levels of very low-density lipoprotein (VLDL) and intermediate-density lipoprotein (IDL) in plasma. To investigate the atherogenic role of VLDL and IDL, the lipoprotein fraction containing both VLDL and IDL (apoEko-VLDL/IDL) was isolated from plasma of apoE-knockout mice by ultracentrifugation, and its interaction with macrophages was studied. When peritoneal macrophages obtained from apoE-knockout mice were incubated with apoEko-VLDL/IDL, the level of cellular cholesteryl esters (CE) increased with the concentration of apoEko-VLDL/IDL. The level of cellular cholesteryl [3H]oleate formed reached 15.1 nmol/mg of cell protein upon incubation with 50 microg/mL apoEko-VLDL/IDL for 18 h, which was an 8.4-fold increase over the corresponding level induced by low-density lipoprotein (LDL). The cellular CE mass was also significantly increased by apoEko-VLDL/IDL. Morphologically, after exposure to apoEko-VLDL/IDL, macrophages became strongly stained with Sudan black B. The total binding of [125I]apoEko-VLDL/IDL to macrophages was effectively replaced by more than 80% by an excess of the unlabeled ligand. Specific binding, calculated by subtracting the nonspecific binding from the total binding, exhibited a saturation pattern. Similar results were obtained with cell association and degradation experiments. In addition, the endocytic degradation of [125I]apoEko-VLDL/IDL was partially inhibited by LDL, whereas acetyl-LDL did not show any effect. These results indicated that apoEko-VLDL/IDL in its unmodified form produced significant CE accumulation in macrophages through a specific and apoE-independent pathway. This pathway may explain, in part, the mechanisms of foam cell formation in arterial walls and the subsequent development of atherosclerosis in apoE-knockout mice.

A novel hepatic stellate (Ito) cell-derived protein, epimorphin, plays a key role in the late stages of liver regeneration

Limited data exist regarding morphogenesis and differentiation during liver regeneration. We examined the role of epimorphin on liver regeneration. After 70% partial hepatectomy, mouse liver was collected on days 1, 3, 7, and 14 for immunohistochemistry and the detection of epimorphin mRNA and connexin 32. Using primary cultured rat hepatocytes, morphogenesis and differentiation of cells were tested with or without epimorphin. Seven days after cell inoculation, the expression of connexin 32 and the cell-cell communication was tested as a marker of differentiation. Epimorphin was detected exclusively in hepatic stellate cells. Connexin 32 was detected only in hepatocytes. After partial hepatectomy, epimorphin mRNA was detected on day 3 and peaked at day 7, followed by protein expression. Connexin 32 expression showed a similar time course. Cultured hepatocytes formed multicellular spheroids in an active epimorphin-coated culture dish and showed positive dye coupling, whereas the cell-cell communication was lost without active epimorphin. Because epimorphin was expressed late in liver regeneration, it might play a role in morphogenesis and differentiation.

Diffuse bilateral thalamic astrocytomas as examined serially by MRI

We report the case of a 13-year-old girl with diffuse bilateral thalamic astrocytomas. Incoordination was observed at the onset. Cranial computed tomography (CT) showed enlarged thalami, and magnetic resonance imaging (MRI) revealed these lesions to be symmetrically enlarged with high intensity on the T2-weighted image. Owing to these atypical findings in the neuroimaging studies, we had difficulty in making the correct diagnosis of a brain tumor. After the diagnosis of diffuse bilateral thalamic astrocytomas was obtained, we performed hyperfractionated radiotherapy followed by chemotherapy. Radiation therapy was effective for a while, but the girl's condition deteriorated again and she died 8 months after admission. Although diffuse bilateral thalamic astrocytomas are difficult to diagnose because they do not resemble most other neoplasms on neuroimaging studies, pediatricians should keep this entity in mind in order to arrive at a precise and prompt diagnosis.

A novel prolyl endopeptidase inhibitor, JTP-4819--its behavioral and neurochemical properties for the treatment of Alzheimer's disease

Formation of beta-amyloid and neurofibrillary tangles in the brain due to genetic or other factors is the most frequent cause of Alzheimer's disease. In addition, marked reduction of certain brain neuropeptide levels is a consistent finding in patients with Alzheimer's disease, together with the deterioration of cholinergic neurons. Currently, there is great demand for the development of new drugs to improve memory deficits or to delay the neurodegenerative process in conditions such as Alzheimer's disease. In this report, the pharmacological actions of JTP-4819, a novel specific prolyl endopeptidase (PEP) inhibitor devised for the treatment of Alzheimer's disease, are reviewed with respect to its effects on PEP activity, neuropeptidergic and cholinergic neurons, and memory-related behavior in rats. We also discuss the possible beneficial effect of JTP-4819 on beta-amyloid metabolism and its potential neuroprotective properties.

A new hemoglobin variant found during Hb A1c measurement: Hb Hokusetsu [beta52(D3)Asp-->Gly]

A new beta chain variant was accidentally found through the assay of Hb A1c in a diabetic patient. The variant was detected by polyacrylamide gel isoelectrofocusing and electrospray ionization mass spectrometry. For sequence determination, globin was cleaved with combination of trypsin and lysyl endopeptidase and analyzed by high performance liquid chromatography connected to electrospray ionization mass spectrometry. An abnormal betaT-5 peptide was found by reconstructed selected ion monitoring. The collision-induced dissociation spectrum of an ion derived from the abnormal betaT-5 peptide revealed a new substitution, [beta52(D3)Asp-->Gly], named Hb Hokusetsu. The sequence was confirmed with an automatic sequencer using peptides isolated by reversed phase high performance liquid chromatography. Amplification of the beta-globin exon 2 and nucleotide sequencing revealed a GAT-->GGT mutation in codon 52 corresponding to an Asp-->Gly replacement. Electrospray ionization mass spectrometry analysis of the hemolysate showed a reasonable value of 10.4% for glycated globin. The variant migrated as Hb S on isoelectrofocusing. Hematological analysis revealed normal parameters. The patient's hemolysate showed normal stability in the isopropanol test. Oxygen equilibrium studies on the patient's red blood cells and hemolysate showed no significant change in oxygen affinity or cooperativity.

Simple and defined method to detect the SOD-1 mutants from patients with familial amyotrophic lateral sclerosis by mass spectrometry

Mutations in Cu/Zn superoxide dismutase (SOD1) cause a subset of cases of familial amyotrophic lateral sclerosis (FALS). We established a simple and defined method to detect the mutant SODI in erythrocytes by electrospray ionization mass spectrometry (ESIMS) using materials precipitated with specific antiserum. Hemolysate was mixed with anti-SOD1 antiserum and the generated precipitate, which was soluble in the solvent for MS analysis, was injected on to an LC column connected to an ESI-mass spectrometer. MS spectra of the reduced SOD1 prepared from normal individuals showed ion peaks corresponding to free monomer SOD1. The spectra from FALS patients revealed doublet ion peaks corresponding to normal and mutant components. The ratios of mutant to normal SOD1 were about 1/2 in cases of (G37R) and (A4S), and about 0.15 in a case of (H46R). This method provides for the rapid diagnosis using small amount of specimens, and will contribute to elucidate the pathomechanism of FALS through the quantification of SOD1 mutants in erythrocytes and in tissues of nervous systems.

[Detection and characterization of aberrant blood proteins and quantification of glycated hemoglobin by mass spectrometry]

Electrospray Ionization Mass Spectrometry can be applied to detect aberrant proteins using intact molecules. Direct examination of hemolysate might well facilitate rapid ascertainment of a variant hemoglobin (Hb) provided that the mass difference between normal and abnormal chains is larger than the resolution power of standard instruments (i.e. = 10 Da). We propose immunoprecipitation as a preparation method of plasma and cell proteins other than Hb prior to MS. Amino acid sequences of various variants detected by MS were determined by MS/MS. Some of these variants were new. These new variants were; 1: Hb Sagami[beta 139(H17)Asn-->Thr]. 2: Hb Hokusetsu[beta 52(D3)Asp-->Gly]. 3: a variant transthyretin, amyloidogenic, [38Asp-->Ala]. 4: a variant transthyretin, non-amyloidogenic, [101Gly-->Ser]. The abundance of ion peaks showed the approximate ratio of each component, which was in agreement with the ratio obtained by chromatography and by ESIMS in the analyses of glycated hemoglobin. Samples with low kidney function (BUN > 50 mg/dl, creatinine > 2.5 mg/dl) showed higher values of glycated Hb on routine HPLC than the MS method. Samples containing high carbamylated Hb might cause this discrepancy.

Effects of teprenone on gastric epithelial restoration in a rabbit cultured cell model

The mechanism of action of gastrocytoprotective agents is not fully understood. We assessed the effects of an anti-ulcer agent, teprenone, and bile acid on epithelial restoration. Teprenone with or without deoxycholic acid was added to a complete confluent cultured gastric epithelial cell sheet after wounding. Restoration was monitored for 48 h, and the wound size was assessed. Migration velocity was measured, and proliferation was detected by sequential staining with bromodeoxyuridine. The labeling index was calculated. Restoration was completed within 48h in controls, whereas deoxycholic acid retarded repair. The migration velocity was suppressed by deoxycholic acid treatment. The number of proliferative cells peaked at 36 h (labeling index, 1.7%) in controls. In the deoxycholic acid group, the maximal labeling index was 0.5% at 48 h. Teprenone abolished the bile acid-induced retardation. Teprenone showed cytoprotective effects against deoxycholic acid-induced inhibition of epithelial cell migration and proliferation.

Molecular cloning, functional expression and tissue distribution of rat acyl-coenzyme A:cholesterol acyltransferase

Acyl-coenzyme A:cholesterol acyltransferase (ACAT) is an enzyme catalyzing the intracellular formation of cholesteryl esters from free cholesterol and fatty acyl-CoA. In the present study, we cloned rat ACAT cDNA and determined its tissue distribution. Rat ACAT cDNA, having a coding region of 1635 bp with its deduced protein sequence of 545 amino acids and two typical motifs such as signature sequences and leucine heptad motif, showed 83, 92 and 90% identity with human, mouse, and hamster ACAT, respectively. Expression of rat ACAT cDNA in A293 cells and CHO cells resulted in a 3.0 to 3.5-fold increase in the enzyme activity. Among twelve tissues examined, ACAT activity was highest in adrenal followed by liver and intestine while that of aorta was extremely low. The mRNA level was also the highest in adrenal among four tissues examined. However, in contrast to its high ACAT activity, the liver mRNA level was extremely low (adrenal >> intestine > aorta >> liver). Consistent with mRNA levels, immunohistochemical analyses with a specific ACAT antibody detected significant ACAT signals in adrenal and intestine but a negligible signal in liver. These results indicate that adrenal most abundantly expresses ACAT in rat. Furthermore, rat liver showed a high ACAT activity but an extremely low ACAT mRNA and negligible immunohistochemical reactivity, suggesting the presence of a structurally different ACAT protein(s) in rat liver.

Biochemical evidence for oligomerization of rat adrenal acyl-coenzyme A:cholesterol acyltransferase

Acyl-coenzyme A:cholesterol acyltransferase (ACAT) in rat adrenal was compared with that in rat liver. Immunoblot analyses of the microsomal fractions from adrenal with an anti-human ACAT antibody detected a 45 kDa protein. Upon pretreatment of these microsomal fractions with chemical cross-linkers such as BS3 and Sulfo-EGS, the 45 kDa band decreased with a concomitant increase in high molecular weight proteins (55, approximately 100, and approximately 230 kDa), suggesting that ACAT constitutes oligomers of 45 kDa monomers associated with a 10 kDa protein. In sharp contrast, the same immunoblot analysis of rat liver microsomal fractions identified a 50 kDa protein which was not cross-linked by these cross-linkers. Moreover, when four ACAT inhibitors were tested for their effects on adrenal and liver enzymes, NTE-122, CI-976, and E5324 were more effective for the liver enzyme, whereas 58-035 was much more effective for adrenal ACAT. These biochemical and pharmacological observations support the notion that the rat liver ACAT protein is distinct from the adrenal counterpart.

Isolation of macrophage-like cell mutants resistant to the cytotoxic effect of oxidized low density lipoprotein

A high concentration of oxidized low density lipoprotein (Ox-LDL) showed a cytotoxic effect on mouse macrophage-derived J774 cells. Mutant cells were selected from these cells that were resistant to the cytotoxic effect of Ox-LDL. One mutant form, named JO21b cells, was characterized in the present study. In spite of a marked resistance to the cytotoxic effect of Ox-LDL, JO21b cells were apparently as sensitive as the parent cells not only to toxic moieties of Ox-LDL, such as 7-ketocholesterol and lysophosphatidylcholine, but also to t-butyl hydroperoxide, an artificial lipid hydroperoxide analog. However, the cellular association of 125I-labeled Ox-LDL with, and subsequent endocytic degradation by JO21b cells was reduced by 70-80% compared with J774 cells. Similarly, accumulation of cholesteryl esters in JO21b cell by Ox-LDL was also reduced by 70%. Northern blot analyses of type I and type II macrophage scavenger receptors (type I and type II MSR) demonstrated that the mRNA levels of JO21b cells were lower than those of J774 cells. Moreover, peritoneal macrophages obtained from MSR-knockout mice showed a higher resistance to the cytotoxic effect of Ox-LDL than those from their wild-type littermates. Our results suggest, therefore, that macrophage scavenger receptor-mediated endocytic uptake of oxidized low density lipoproteins (Ox-LDL) may play an enhancing role in Ox-LDL cytotoxicity to macrophages or macrophage-derived cells.

Reduced expression of the macrophage scavenger receptors in macrophage-like cell mutants resistant to brefeldin A

Brefeldin A (BFA)-resistant mutants, JB15, JB23 and JB33, were isolated from mutagenized murine macrophage-like (J774) cells and their modified low density lipoprotein (LDL) metabolism was studied. When JB23 cells, the most resistant clone, were incubated with acetylated LDL, intracellular accumulation of cholesteryl esters (CE) was reduced by 31% as compared with J774 cells. The cell-association of 125I-acetyl-LDL with, and subsequent endocytic degradation by JB23 cells were reduced by 40-60% compared with J774 cells. Western and Northern blot analyses showed that the protein and mRNA levels of the macrophage scavenger receptors (MSR) were reduced by 68% and 55% respectively in JB23 cells as compared with those in J774 cells. These results indicate that a putative BFA-target molecule(s) might regulate MSR gene expression as well as macrophage-derived foam cell formation.

Lipid lowering effects of pravastatin in common marmosets

In the present study it was examined if the common marmoset was susceptible to pravastatin (CAS 81131-70-6, CS 514, Mevalotin), an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase. It has been reported that serum lipid levels in common marmosets resemble those in humans. First serum total cholesterol and lipoprotein cholesterol levels of common marmosets were examined in comparison with those in seven different experimental animals including cynomolgus monkeys, beagle dogs, Watanabe heritable hyperlipidemic rabbits, Japanese White Rabbits, Sprague Dawley rats, Wistar-Imamichi rats and golden hamsters. The animals were fed normal chow diets, and total- and lipoprotein-cholesterol levels were determined under identical conditions. The quantitative and polyacrylamide electrophoresis studies indicated that among animals examined serum lipid and lipoprotein profiles in common marmosets were similar to those in humans. When pravastatin at 1-30 mg/kg was orally administered to common marmosets for 28 days, total, low density lipoprotein (LDL)- and high density lipoprotein-cholesterol levels were decreased in a dose dependent manner, whereas triglycerides and very low density lipoprotein cholesterol did not change. These findings confirm that common marmosets have serum lipid and lipoprotein profiles similar to those in humans suggesting that they are susceptible to lipid lowering effects of HMG-CoA reductase inhibitors.

Effect of a prolyl endopeptidase inhibitor, JTP-4819, on radial maze performance in hippocampal-lesioned rats

The effect of a novel prolyl endopeptidase (PEP) inhibitor, (S)-2-2[[(S)-2-(hydroxyacetyl)-1-pyrrolidinyl]carbonyl]-N-(phenylmethyl) -1-pyrrolidinecarboxamide (JTP-4819), on spatial learning deficits in rats with dorsal hippocampal (DH) lesions was examined using an eight-arm radial maze. The correct performance remained at chance levels even after 18 acquisition trials in rats with DH lesions. JTP-4819 (3.0 mg/kg, p.o.) significantly ameliorated this learning impairment after 34-41 days of treatment. When DH lesions were created in rats after achievement of learning, postoperative performance deteriorated prominently, but gradually recovered with the repetition of trials. JTP-4819 (3.0 mg/kg, p.o.) significantly decreased the number of trials needed to reattain learning criterion. After the behavioral experiment, the choline acetyltransferase (ChAT) activity and [3H]-pirenzepine binding (Kd, Bmax) in the residual hippocampus and cerebral cortex were analyzed. Neither parameter was significantly affected by JTP-4819. In conclusion, JTP-4819 can improve both learning and relearning deficits of spatial memory in DH-lesioned rats, postulating that enhancement of neuropeptide activity via PEP inhibition may be involved in the mechanism of action of JTP-4819.

Liver transplantation in a case of hypoproteinemia and coagulopathy

A female infant with hypoproteinemia and coagulopathy associated with hypertyrosinemia was successfully treated with living-related liver transplantation (LRLT). On the 12th day of life plasma amino acid analysis revealed a marked elevation of tyrosine, so the patient was fed on a low-tyrosine and low-phenylalanine diet. However, hepatosplenomegaly, hypotonia, alopecia, eczema and psychomotor delay did not improve and recurrent episodes of disseminated intravascular coagulation (DIC) caused her condition to deteriorate. Liver biopsy on the 230th day revealed marked fatty change accompanied by mild to moderate cholestasis. Therefore, LRLT from her father was performed on the 286th day resulting in improvement of all the aforementioned signs and symptoms. Despite a thorough examination, no diagnosis of a known disorder could be established. However, her elder brother had also been born with severe hypoproteinemia and coagulopathy, and died of DIC on the second day of life. Thus, the disorder is designated as a new entity, namely 'congenital hypoproteinemia and coagulopathy associated with hypertyrosinemia'.

Hb Peterborough [beta 111(G13)Val-->Phe] in Japan; rapid identification by ESI/MS using proteolytic digests of oxidized globin

A variant hemoglobin was found in a Japanese female whose hemoglobin was studied to clarify the cause of a low Hb A1c value, found during a routine medical examination. The detection and identification of the variant was performed by electrospray ionization mass spectrometry. Its structure was revealed to be the same as Hb Peterborough [beta 111(G13)Val-->Phe]. For sequence determination, oxidized globin as well as non-derivatized globin were cleaved by trypsin and lysyl endopeptidase. An abnormal peptide was found in digests of oxidized globin, as shown by electrospray ionization mass spectrometry. Cysteic acid in oxidized peptides enhanced the abundance of fragment ions in tandem mass spectrometry, which helped to quickly and accurately determine the substitution in beta T-12, a peptide in the core region. Electrospray ionization mass spectrometry analysis of the hemolysate also showed a low level of glycated hemoglobin. The patient's hemolysate showed decreased stability in the isopropanol test. An abnormal band was detected on isoelectrofocusing on the cathodic side of normal Hb A. This is the second report of Hb Peterborough and the first of its occurrence in Japan.

Early-stage Alzheimer's disease and multiple subcortical infarction with mild cognitive impairment: neuropsychological comparison using an easily applicable test battery

We conducted a neuropsychological study comparing early-stage Alzheimer's disease (AD; n = 22) and multiple subcortical infarction with mild cognitive impairment (MSI; n = 22) using an easily applicable test battery which included 8 tests. Two groups were matched for age, education and score on the Mini-Mental State Examination. Patients with AD had significantly lower scores than MSI patients in the delayed recall of the Rey-Osterrieth Complex Figure, while MSI patients had significantly worse scores in the Wisconsin Card-Sorting Test. This suggests that early discrimination of MSI from AD can be made by frontal system impairment in MSI and episodic memory disturbance in the visuospatial domain in AD using simple neuropsychological tests.

[Studies of psychiatric symptoms and personality traits in the 90+ years population]

Depressive symptoms and personality traits 90+ years population were examined. Data were obtained from 33 aged people (mean 93 +/- 3.2 years old; range 90-105 years old) using the Hamilton Rating Scale for depression and a questionnaire for the evaluation of type A personality trait (devised by Dr. Maeda). Scores of > 11 in the Hamilton Rating Scale for depression were considered indicative of depression. This score was found in 39% of cases. There are four types of depressive symptoms among the 90+ years population: sleep disturbance and somatic complain type; depressive mood type; hypochodrical type; reference of ideas and obsessive-compulsive type. The usual distributions of symptoms is 43, 29, 21 and 7% respectively. According to the questionnaire for type A personality trait among the 33 cases, there were more people with type A personality (n = 18; 56%) than there were those with type B (n = 15; 44%). Of the total number of cases studied, there was a tendency high scores to be achieved items characteristic of type A personality, such as a thorough native, self-confidence and precision. On the other hand, there are also tendencies for flexibilities and "going-my-way" traints in the 90+ year population. There is a significant correlation between scores in Hamilton Rating Scale for depression and scores in the type A personality questionnaire.

Transforming growth factor-beta1 suppresses thyrotropin-induced Na+/I- symporter messenger RNA and protein levels in FRTL-5 rat thyroid cells

Iodide transport into the thyroid catalyzed by the Na+/I- symporter (NIS), is the first and main rate-limiting step in thyroid hormone synthesis. Recently, we have demonstrated that thyrotropin (TSH) increases NIS messenger RNA (mRNA) and protein levels, as well as iodide uptake activity. Although transforming growth factor-beta1 (TGFbeta1) is known to affect thyroid cell function, it is still unclear how TGFbeta1 regulates TSH-stimulated iodide accumulation. Therefore, the effects of TGFbeta1 on TSH-stimulated NIS mRNA and protein levels were examined in FRTL-5 rat thyroid cells by Northern and Western blot analyses, and iodide uptake was assessed. Northern blot analysis revealed that TGFbeta1 suppressed TSH-stimulated NIS mRNA levels in a dose- and time-dependent manner. Western blot analysis demonstrated that TGFbeta1 suppressed TSH-stimulated NIS protein levels. TGFbeta1 also suppressed (Bu)2 cyclic adenosine monophosphate (cAMP)- and forskolin-stimulated NIS mRNA and protein levels, indicating a role for TGFbeta1 downstream of cAMP production. As predicted, TGFbeta1 inhibited TSH-stimulated iodide uptake activity. These results suggest that the inhibitory effect of TGFbeta1 on TSH-stimulated iodide uptake is at least in part due to a suppression of NIS specific transcription. Therefore, TGFbeta1 may act as an autocrine or paracrine local modulator of thyroid hormone synthesis by influencing NIS mRNA levels in the thyroid.

Iodide uptake and experimental 131I therapy in transplanted undifferentiated thyroid cancer cells expressing the Na+/I- symporter gene

131I therapy is a widely accepted treatment for differentiated thyroid cancers which can accumulate iodide. We evaluated the efficiency of 131I therapy against tumors which are transfected with the Na+/I- symporter (NIS) gene. We transfected the rat NIS cDNA expression vector into malignantly transformed rat thyroid cells (FRTL-Tc) which do not concentrate iodide. The resultant cell line (Tc-rNIS) accumulated 125I 60-fold in vitro. The FRTL-Tc cells formed solid tumors after injection of cells into subcutaneous tissues of Fischer 344 rats. Tumors formed with Tc-rNIS cells accumulated up to 27.3% of total 125I administered, and concentrated 125I 11 to 27-fold in the tumors. Extracorporeal measurement of radioactivity in the tumors revealed that 125I accumulation peaked at 90 min, and decreased to half levels 6 h after the injections. To investigate the effect of 131I administration on the tumor growth, we injected Na131I 2 and 3 weeks after the transplantation of the cells. The Na131I did not change the tumor volume significantly in either the FRTL-Tc or the Tc-rNIS-induced tumors. The short (6 h) effective half life of 131I in the tumors diminished the radiation dose to the tumor cells. However, this approach may prove beneficial in the treatment of radiosensitive cancers, and could be employed diagnostically.

Polyarteritis nodosa associated with gastric carcinoma and hepatitis B virus infection

Several cases of polyarteritis nodosa associated with malignant disorders have been reported, most with bone marrow-related tumors. We report polyarteritis nodosa presenting with a fever of unknown origin and muscle weakness that was complicated by advanced gastric carcinoma and hepatitis B virus-positive cirrhosis. Vasculitis was diagnosed after gastrectomy from histologic findings of arterial vasculitis on the resected gastric carcinoma. Our case is so far the second such report of polyarteritis nodosa associated with gastric cancer.

Relevance of immunoglobulin G Fc receptor polymorphism to recurrence of adult periodontitis in Japanese patients

Polymorphonuclear neutrophil (PMN) phagocytic function has been shown to be impaired in some patients with periodontitis. PMN constitutively express members of two immunoglobulin G receptor (Fc gammaR) classes: Fc gammaRIIa (CD32) and Fc gammaRIIIb (CD16). Both receptors exhibit genetically determined structural and functional biallelic polymorphisms, which have been shown to influence PMN phagocytic function. In this study, we assessed the relevance of these Fc gammaR polymorphisms to susceptibility to adult periodontitis and recurrence rate. The distribution of Fc gammaRIIa and Fc gammaRIIIb genotypes of 100 Japanese patients with adult periodontitis during follow-up was compared to the distribution of genotypes in 105 race-matched healthy controls. No significant skewing of distributions of Fc gammaRIIa and Fc gammaRIIIb genotypes was observed between patients and controls. Notably, however, a significant overrepresentation of the Fc gammaRIIIb-NA2 allotype was found in patients with disease recurrence (P < 0.05; odds ratio, 4.29; 95% confidence interval, 1.19 to 16.24). Moreover, the annual rate of recurrence was significantly higher in patients with the Fc gammaRIIIb-NA2/NA2 and Fc gammaRIIIb-NA1/NA2 genotypes than in Fc gammaRIIIb-NA1/NA1 individuals (P < 0.05). Fc gammaRIIa-R/R131 individuals also exhibited higher recurrence rates, though the difference was not statistically significant (P = 0.06). These results suggest that the Fc gammaRIIIb-NA2 allotype represents a risk factor for recurrence of adult periodontitis.