Comparison of osseous healing after sagittal split ramus osteotomy and intraoral vertical ramus osteotomy

The sagittal split ramus osteotomy (SSRO) is generally associated with greater postoperative stability than the intraoral vertical ramus osteotomy (IVRO); however, it entails a risk of inferior alveolar nerve damage. In contrast, IVRO has the disadvantages of slow postoperative osseous healing and projection of the antegonial notch, but inferior alveolar nerve damage is believed to be less likely. The purposes of this study were to compare the osseous healing processes associated with SSRO and IVRO and to investigate changes in mandibular width after IVRO in 29 patients undergoing mandibular setback. On computed tomography images, osseous healing was similar in patients undergoing SSRO and IVRO at 1year after surgery. Projection of the antegonial notch occurred after IVRO, but returned to the preoperative state within 1year. The results of the study indicate that IVRO is equivalent to SSRO with regard to both bone healing and morphological recovery of the mandible.

Mechanism of motor coordination of masseter and temporalis muscles for increased masticatory efficiency in mice

The demand for the use of mice as animal models for elucidating the pathophysiologies and pathogeneses of oral motor disorders has been increasing in recent years, as more and more kinds of genetically modified mice that express functional disorders of the stomatognathic system become available. However, the fundamental characteristics of mouse jaw movements during mastication have yet to be fully elucidated. The purpose of this study was to investigate the roles of the masseter and temporalis muscles, and the mechanisms of motor coordination of these muscles for increasing masticatory efficiency in the closing phase in mice. Twenty-two male Jcl:ICR mice were divided into control (n = 8), masseter-hypofunction (n = 7) and temporalis-hypofunction groups (n = 7). Botulinum neurotoxin type A (BoNT⁄A) was used to induce muscle hypofunction. The masticatory movement path in the horizontal direction during the occlusal phase became unstable after BoNT⁄A injection into the masseter muscle. BoNT⁄A injection into the temporalis muscle decreased antero-posterior excursion of the late-closing phase corresponding to the power phase of the chewing cycle. These results suggest that the masseter plays an important role in stabilizing the grinding path, where the food bolus is ground by sliding the posterior teeth from back to front during the occlusal phase. The temporalis plays a major role in retracting the mandible more posteriorly in the early phase of closing, extending the grinding path. Masticatory efficiency is thus increased based on the coordination of activities by the masseter and temporalis muscles.

Affinity imaging mass spectrometry (AIMS): high-throughput screening for specific small molecule interactions with frozen tissue sections

A novel screening system, called affinity imaging mass spectrometry (AIMS), identifies candidate small molecules with specific affinity for nanoscale structures, including proteins, in unfixed human tissue sections.

Association between hydration volume and symptoms in terminally ill cancer patients with abdominal malignancies

BACKGROUND

To explore the association between hydration volume and symptoms during the last 3 weeks of life in terminally ill cancer patients.

PATIENTS AND METHODS

This was a multicenter, prospective, observational study of 226 consecutive terminally ill patients with abdominal malignancies. Primary responsible physicians and nurses evaluated the severity of membranous dehydration (dehydration score calculated from three physical findings), peripheral edema (edema score calculated from seven physical findings), ascites and pleural effusion (rated as physically undetectable to symptomatic), bronchial secretion, hyperactive delirium (Memorial Delirium Assessment Scale), communication capacity (Communication Capacity Scale), agitation (Agitation Distress Scale), myoclonus and bedsores.

RESULTS

Patients were classified into two groups: the hydration group (n=59) who received 1 l or more of artificial hydration per day, 1 and 3 weeks before death, and the non-hydration group (n=167). The percentage of patients with deterioration in dehydration score in the final 3 weeks was significantly higher in the non-hydration group than the hydration group (35% versus 14%; P=0.002), while the percentages of patients whose symptom scores for edema, ascites and pleural effusion increased were significantly higher in the hydration group than the non-hydration group (44% versus 29%, P=0.039; 29% versus 8.4%, P <0.001; 15% versus 5.4%, P=0.016; respectively). After controlling for multiple covariates and treatment settings, the association between hydration group and dehydration/ascites score was statistically significant. Subgroup analysis of patients with peritoneal metastases identified statistically significant interaction between hydration group and dehydration/pleural effusion score. There were no significant differences in the degree of bronchial secretion, hyperactive delirium, communication capacity, agitation, myoclonus or bedsores.

CONCLUSIONS

Artificial hydration therapy could alleviate membranous dehydration signs, but could worsen peripheral edema, ascites and pleural effusions. It is suggested that the potential benefits of artificial hydration therapy should be balanced with the risk of worsening fluid retention symptoms. Further clinical studies are strongly needed to identify the effects of artificial hydration therapy on overall patient well-being, and an individualized treatment and close monitoring of dehydration and fluid retention symptoms is strongly recommended.

Changes in lung-specific molecular expression during differentiation of hamster embryonic M3E3/C3 cell line

To clarify the differentiation mechanisms of bronchiolar epithelial cells, changes at the transcription level of epithelial cell-specific proteins were examined using M3E3/C3, a cell line derived from hamster fetal lung. During a 9-day incubation period with 24 microg/mL of retinol, the cells became attached to each other and formed large bud-like structures which could be detected with periodic acid-Schiff staining. During the incubation period, the mRNA level of surfactant-associated protein-B significantly increased 2.6- and 5.4-fold higher than cells incubated without retinol on days 3 and 9, respectively. The Clara cell-specific secretory protein mRNA level also increased and peaked at 5.1-fold (P < 0.05) on day 5 compared with control cells. In contrast, mRNA for surfactant-associated protein-C, an alveolar type II cell-specific protein, decreased. Moreover, the expression of the gene for hepatocyte nuclear factor 3alpha, a putative transactivating factor for lung-related genes, was up-regulated resulting in consistently higher levels (2.4- to 5.6-fold) compared with controls, while those for transmembrane-type mucin-1 and glyceraldehyde-3-phosphate dehydrogenase were constantly expressed during the incubation. The present study confirms that at the gene transcription level M3E3/C3 cells differentiate into Clara-like cells with mucus granules in the presence of retinol.

Analysis of monoglyceride synthetic reaction in a solvent-free two-phase system catalyzed by a monoacylglycerol lipase from Pseudomonas sp. LP7315

Kinetics of monoglyceride synthesis catalyzed by a monoacylglycerol lipase (MGL) isolated from Pseudomonas sp. LP7315 was studied at 65 degrees C in a solvent-free two-phase system, in which fatty acid droplets were dispersed in a glycerol phase containing a small amount of water. The initial rate of the synthetic reaction depended on several factors: the amounts of fatty acid and glycerol, and the concentration of MGL in the glycerol phase. To analyze the effects of these factors, a kinetic model was developed based on the assumption that the adsorption equilibrium of MGL molecules at the interface between the two phases is the crucial factor for the synthetic reaction. The model was found to yield good approximations of the initial synthetic rate under various reaction conditions. The analysis suggests that the adsorption behavior of MGL onto the interface had a large effect on the initial rate of the monoglyceride synthesis.

Purification and Characterization of a Monoacylglycerol Lipase from Pseudomonas sp. LP7315

A monoacylglycerol lipase (MGL) was purified from Pseudomonas sp. LP7315 by ammonium sulfate precipitation, anion-exchange chromatography, and preparative electrophoresis. The purified enzyme was homogeneous on SDS-PAGE with a molecular mass of 59 kDa. Its hydrolytic activity was confirmed to be specific for monoglycerides: the enzyme did not hydrolyze di- and triglycerides. MGL was found to be stable even after 1-h incubation at 65 degrees C. The optimum pH for monopalmitin hydrolysis was approximately 8. The hydrolytic activity depended not only on temperature and pH but also on the type of monoglyceride used. MGL also catalyzed monoglyceride synthesis at 65 degrees C in a solvent-free two-phase system, in which fatty acid droplets were dispersed in the glycerol phase with a low water content. The synthetic reaction proceeded at a constant rate for approximately 24 h and approximately reached an equilibrium after 48 h of reaction. The initial rate and equilibrium yield of the synthetic reaction depended on the type of fatty acid used as the substrate.

Hypoxic induction of prolyl 4-hydroxylase alpha (I) in cultured cells

Accumulated evidence indicates that hypoxia activates collagen synthesis in tissues. To explore the molecular mechanism of activation, we screened genes that are up-regulated or down-regulated by hypoxia. Fibroblasts isolated from fetal rat lung were cultured under hypoxia. Differential display technique showed that the mRNA level of prolyl 4-hydroxylase (PH) alpha(I), an active subunit that catalyzes the oxygen-dependent hydroxylation of proline residue in procollagen, increased 2-3-fold after an 8-h exposure to hypoxia. This elevated level was maintained over 40 h and returned to the basal level after reoxygenation. The transcription rate, protein level, and hydroxyproline content (an indicator of the prolyl hydroxylation) were all elevated by hypoxic culture. Analysis of the promotor region of PHalpha(I) gene indicated that a motif similar to hypoxia-responsive element (HRE) of hypoxia-inducible genes such as erythropoietin, was identified within a 120-base pair sequence upstream of the transcription start site. Luciferase reporter assay and mutational analysis showed that a site similar to the HRE in this motif is functionally essential to hypoxic response. Electrophoretic mobility shift assay revealed that hypoxia-inducible factor-1 was stimulated and bound to the PHalpha(I) HRE upon hypoxic challenge. Our results indicate that PHalpha(I), an essential enzyme for collagen synthesis, is a target gene for hypoxia-inducible factor-1.

New estrogenic antagonists bearing dicarba-closo-dodecaborane as a hydrophobic pharmacophore

We have designed and synthesized estrogen antagonists bearing dicarba-closo-dodecaborane (carborane) as a hydrophobic pharmacophore based on the structure of 1-(4-hydroxyphenyl)-1,12-dicarba-closo-dodecaborane, a potent estrogen agonist that we reported previously. Compounds with a long alkyl chain bearing an amide moiety on the carborane skeleton (6, 7) showed estrogen antagonistic activity in a luciferase reporter gene assay using COS-1 cells transfected with a rat ER alpha-expression plasmid and as an appropriate reporter plasmid.

Estrogenic antagonists bearing dicarba-closo-dodecaborane as a hydrophobic pharmacophore

Dicarba-closo-dodecaboranes (carboranes), which have spherical geometry and hydrophobicity, are applicable as a hydrophobic pharmacophore of biologically active molecules. We have designed and synthesized estrogenic antagonists based on the structure of the potent agonist 1-hydroxymethyl-12-(4-hydroxyphenyl)-1,12-dicarba-closo-d odecaborane, which we have developed. The compounds showed potent antagonistic activity in luciferase reporter gene assay using COS-1 cells transfected with rat ER alpha-expression plasmid and an appropriate reporter plasmid.

Protein kinase C modulators bearing dicarba-CLOSO-dodecaborane as a hydrophobic pharmacophore

The size and position of a hydrophobic moiety on a benzolactam skeleton, which reproduces the active conformation and biological activity of teleocidins, play an important role in the appearance of the activity. We have designed and synthesized benzolactams bearing dicarba-closo-dodecaborane. These compounds showed potent binding affinity to protein kinase C, providing a further example of the application of carborane as the hydrophobic pharmacophore of biologically active molecules.

Serum thrombopoietin levels in patients with chronic hepatitis and liver cirrhosis

OBJECTIVE

Thrombocytopenia is a common manifestation of cirrhosis. The aim of this study was to examine the relationship between serum thrombopoietin concentrations, circulating platelet levels, and the stage of hepatic fibrosis in patients with chronic viral hepatitis.

METHODS

The study included 48 patients with chronic viral hepatitis (14 with stage 1 fibrosis; five with stage 2 fibrosis; three with stage 3 fibrosis; 26 with cirrhosis) and 30 healthy volunteers. Serum thrombopoietin levels were measured using an enzyme-linked immunosorbent assay. Spleen size, platelet counts, and prothrombin time were measured.

RESULTS

Thrombopoietin levels of patients with fibrosis stage 1 (2.50 +/- 1.60 fmol/ml) or stage 2 (1.89 +/- 0.65) were significantly higher than those in patients with cirrhosis (1.21 +/- 0.55) or healthy volunteers (1.26 +/- 0.74). Mean platelet counts of patients with cirrhosis (8.0 +/- 4.6 x 10(4)/microl) were significantly lower than those with fibrosis stage 1 (18.6 +/- 3.9) or stage 2 (16.0 +/- 5.8), or healthy volunteers (24.5 +/- 7.3). Patients with cirrhosis had larger spleens (30.9 +/- 18.4 cm2) than those with fibrosis stage 1 (18.2 +/- 6.4). Platelet counts showed a significant inverse relationship to spleen size (p = -0.51, p < 0.0005) and a significant positive relationship with thrombopoietin levels (p = 0.34, p < 0.02). Thrombopoietin levels were significantly correlated to prothrombin time (p = 0.45, p < 0.005).

CONCLUSIONS

Serum thrombopoietin levels are elevated in patients with an early stage of chronic viral hepatitis. As the disease progresses from mild fibrosis to cirrhosis, decreased production of thrombopoietin may contribute to the further development of thrombocytopenia in cirrhosis.

OPC-13013, a cyclic nucleotide phosphodiesterase type III, inhibitor, inhibits cell proliferation and transdifferentiation of cultured rat hepatic stellate cells

Activated hepatic stellate cells (HSC; lipocytes; Ito cells) proliferate and are responsible for extracellular matrix synthesis during hepatic fibrogenesis. During activation, HSC undergo transdifferentiation into myofibroblasts expressing alpha-smooth muscle actin (alpha-SMA). Adenosine 3', 5'-cyclic monophosphate (cyclic AMP) is an ubiquitous intracellular signaling molecule, and is upregulated by the activation of adenylate cyclase and downregulated via hydrolysis by cyclic nucleotide phosphodiesterases (PDEs). Recently, increased intracellular cyclic AMP has been shown to inhibit HSC activation. The aim of the current study was to determine the effects of inhibition of PDEs on cell proliferation and transdifferentiation in cultured rat HSC. Cell proliferation was determined by [3H]thymidine incorporation, and Western blot analysis was performed for detection of alpha-SMA, a phenotypic marker of transdifferentiation into myofibroblast. When the cells were exposed to 3-isobutyl-1-methylxanthine (IBMX; 50-1000 microM), a nonselective PDE inhibitor, serum-stimulated [3H]thymidine incorporation was suppressed in a dose-dependent manner with a maximum inhibition of 66% at a concentration of 500 microM OPC-13013 (1-60 microM), a selective PDE III isoenzyme inhibitor, induced a dose-dependent inhibitory effect on serum-stimulated DNA synthesis that reached a maximum inhibition of 95% at a concentration of 60 microM, while neither 8-methoxymethyl-3-isobutyl-1-methylxanthine (8-MMX), a PDE I isoenzyme inhibitor, nor Ro-20-1724, a PDE IV isoenzyme inhibitor, had an inhibitory effect. Western blot analysis revealed that IBMX or OPC-13013 decreased alpha-SMA expression, while other selective PDE isoenzyme inhibitors did not have a suppressive effect. IBMX, OPC-13013 or Ro-20-1724, but not 8-MMX augmented forskolin-induced increase in intracellular cyclic AMP levels although cyclic AMP levels were not affected by treatment with any of these PDE inhibitors alone. These data indicate that inhibition of PDEs, especially PDE III isoenzyme, can produce an inhibitory effect on HSC activation. The PDE III isoenzyme may contribute to the regulation of HSC activation during fibrogenesis. In addition, OPC-13013 may have the potential to inhibit initiation and progression of hepatic fibrosis by interfering with HSC activation.

Involvement of Arg-328, Arg-334 and Arg-342 of DnaA protein in the functional interaction with acidic phospholipids

We reported previously that three basic amino acids (Arg-360, Arg-364 and Lys-372) of DnaA protein are essential for its functional interaction with cardiolipin. In this study, we examined the effect of mutation of some basic amino acids in a potential amphipathic helix (from Lys-327 to Ile-345) of DnaA protein on this interaction. ATP binding to the mutant DnaA protein, in which Arg-328, Arg-334 and Arg-342 were changed to acidic amino acids, was less inhibited by cardiolipin than that of the wild-type protein, as was the case for mutant DnaA protein with mutations of Arg-360, Arg-364 and Lys-372. A mutant DnaA protein with mutations of all six basic amino acids showed the most resistance to the inhibition of ATP binding by cardiolipin. These results suggest that Arg-328, Arg-334 and Arg-342, like Arg-360, Arg-364 and Lys-372, are also involved in the functional interaction between DnaA protein and acidic phospholipids.

Mechanism involved in synergistic adrenocorticotropin response to activating protein kinase-A and -C in rat anterior pituitary cells

Activation of protein kinase C (PKC) stimulates adrenocorticotropin (ACTH) release synergistically in the presence of corticotropin releasing factor (CRF). We examined the effect of a cyclic nucleotide-specific phosphodiesterase inhibitor, 1-isoamyl-3-isobutylxanthine (IIX), on arginine vasopressin (AVP)-induced ACTH release and intracellular cAMP accumulation in normal rat anterior pituitary cells. IIX alone elevated intracellular cAMP accumulation. IIX potentiated AVP-induced ACTH release synergistically without further increase in cAMP accumulation, suggesting that synergistic ACTH release has an alternative mechanism other than the synergistic elevation of intracellular cAMP accumulation which has been reported. Phorbol 12-myristate-13-acetate (PMA) also induced synergistic ACTH release when incubated with IIX. IIX had no additional effect on ACTH response when incubated with maximal dose of CRF, forskolin or 8-bromoadenosine 3',5'-cyclic monophosphate (8-Br-cAMP). Moreover, the combination of PMA and 8-Br-cAMP produced synergistic ACTH response. In conclusion, the synergistic ACTH release from rat pituitary corticotrophs occurs at least in the presence of directly activating events of PKC and PKA as well as PKC-induced inhibition of phosphodiesterase activity.

Urocortin in human placenta and maternal plasma

Plasma immunoreactive (IR-) urocortin (Ucn) and corticotropin-releasing factor (CRF) levels in pregnant women were measured by their specific radioimmunoassays after extraction. Although plasma IR-CRF levels were increased in pregnant women as compared to men and non-pregnant women, there was no difference of plasma IR-Ucn levels among groups. Ucn mRNA was detected in cytotrophoblasts and syncytiotrophoblasts by in situ hybridization. A reverse-phase high-performance liquid chromatography (HPLC) showed the major peak of IR-Ucn in placenta and plasma that had similar chromatographic mobility to synthetic Ucn1-40. These data suggest that Ucn is produced and processed into the same form of synthetic Ucn in placenta, but not secreted into maternal blood.

Urocortin expression in the human central nervous system

OBJECTIVE AND STUDY DESIGN

Urocortin is a recently identified neuropeptide of the corticotrophin-releasing factor (CRF) family in the mammalian brain and has been demonstrated to stimulate ACTH secretion from pituitary cells, but its expression in human brain tissue including the hypothalamus has not been examined. In this study, we first examined urocortin expression in the hypothalamus (20 cases) and pituitary stalks (17 cases) of human brain obtained from autopsy using immunohistochemistry and mRNA in situ hybridization.

RESULTS

Neither urocortin immunoreactivity nor mRNA hybridization signals were detected in the hypothalami and pituitary stalks while CRF immunoreactivity was detected in the paraventricular nuclei of the hypothalami in 10/20 cases and in nerve fibres of the stalks in 17/17 cases. These results indicate that urocortin does not act on the hypothalamo-pituitary-adrenal axis, at least not in the same manner as CRF in humans. We then examined urocortin expression in various portions of the brain in 7 cases. Both urocortin immunoreactivity and mRNA hybridization were detected in Purkinje cells of the cerebellum and anterior horn cells of the spinal cord in specimens examined. Urocortin expression was, however, variably seen in superior olivary nuclei (two out of six cases examined) and in the Edingar-Westphal nuclei (one out of three cases examined).

CONCLUSIONS

The distribution of urocortin in the human central nervous system suggests that urocortin may work as a neurotransmitter like other neuropeptides in the human.

Corticotropin-releasing factor but not urocortin is involved in adrenalectomy-induced adrenocorticotropin release

Urocortin, a new corticotropin-releasing factor (CRF)-related peptide, has been reported to have the ability to bind to CRF receptors and to stimulate adrenocorticotropin (ACTH) secretion from the rat anterior pituitary in vivo and in vitro. In this study, we examined the effect of intravenous administration of urocortin-antiserum to investigate the role of endogenous urocortin on ACTH secretion from rat anterior pituitary after adrenalectomy. Male Sprague-Dawley rats, which were maintained in a conscious and undisturbed condition, were administered non-immunized rabbit serum (NRS), CRF-antiserum or urocortin-antiserum at a volume of 1 ml/kg b.w. 15 min before the injection of secretagogues. Synthetic rat urocortin (2 microg/kg B.W.) increased plasma ACTH concentrations by about sixfold the basal concentration. The pretreatment with urocortin-antiserum but not CRF-antiserum abolished the urocortin-induced increase in plasma ACTH concentrations. In adrenalectomized rats, plasma ACTH concentrations were markedly increased at basal conditions, and rapidly reduced after the administration of CRF-antiserum. By contrast, administration of urocortin-antiserum did not alter ACTH secretion induced by adrenalectomy. Our results suggest that endogenous urocortin is unlikely to be involved in ACTH release in adrenalectomized rats.

Identification of bile canalicular cell surface antigen HAM.4 as dipeptidyl peptidase IV (DPPIV) and characterization of its role in hepatic regeneration after partial hepatectomy in rats

Dipeptidyl peptidase IV (DPPIV) has been implicated in the control of cell growth and differentiation. A rat hepatocyte membrane antigen recognized by a monoclonal antibody (HAM.4) has now been shown to be identical to DPPIV by immunoblot analysis and amino acid sequencing. The amounts of DPPIV immunoreactive protein and enzymatic activity in serum increased in a manner independent of de novo protein synthesis, and without any biochemical or immunohistochemical changes in hepatic DPPIV, during liver regeneration after partial hepatectomy in rats. DPPIV purified from serum by HAM.4 antibody-based affinity chromatography lacked the NH2-terminal 36 amino acids of the membrane-bound enzyme, suggesting that proteolytic cleavage may mediate the release of DPPIV into serum. No significant differences in the restoration of liver mass or in hepatic DNA synthesis were apparent between DPPIV-deficient and normal rats after partial hepatectomy, suggesting that DPPIV may not be essential for hepatic regeneration.

Site-directed mutational analysis for the membrane binding of DnaA protein. Identification of amino acids involved in the functional interaction between DnaA protein and acidic phospholipids

DnaA protein, the initiator of chromosomal DNA replication in Escherichia coli, interacts with acidic phospholipids, such as cardiolipin, and its activity seems to be regulated by membrane binding in cells. In this study we introduced site-directed mutations at the positions of hydrophobic or basic amino acids which are conserved among various bacteria species and which are located in the putative membrane-binding region of DnaA protein (from Asp357 to Val374). All mutant DnaA proteins showed much the same ATP and ADP binding activity as that of the wild-type protein. The release of ATP bound to the mutant DnaA protein, in which three hydrophobic amino acids were mutated to hydrophilic ones, was stimulated by cardiolipin, as in the case of the wild-type protein. On the other hand, the release of ATP bound to another mutant DnaA protein, in which three basic amino acids were mutated to acidic ones, was not stimulated by cardiolipin. These results suggest not only that the region is a membrane-binding domain of DnaA protein but also that these basic amino acids are important for the binding and the ionic interaction between the basic amino acids and acidic residues of cardiolipin and is involved in the interaction between DnaA protein and cardiolipin.

Oxygen tension regulates heme oxygenase-1 gene expression in mammalian cell lines

The gene expression of heme oxygenase-1 (HO-1) was studied in mammalian cell lines exposed to hyperoxia. Northern blot analysis demonstrated that hyperoxic exposure increased the HO-1 mRNA levels in various types of cells, including human hepatoma (HepG2) cells. This increase was time- and dose-dependent, and reversible. The HO-1 mRNA levels in HepG2 cells were increased to 2.3- and 4.2-fold of the control by hyperoxic exposure of 6 and 23 h, respectively. Cycloheximide and actinomycin D inhibited the increases in the HO-1 mRNA level produced by hyperoxia, indicating that response to hyperoxia is dependent on de novo protein synthesis and mRNA transcription. Antioxidants, desferrioxamine (DES) and o-phenanthroline (OP) partially inhibited the HO-1 mRNA elevation by hyperoxia. In addition to hyperoxia, sodium arsenite (NaAsO2), cadmium chloride (CdCl(2)) and hydrogen peroxide (H2O2), which are reactive oxygen intermediates (ROI) generators, increased the HO-1 mRNA level by 11-, 22- and 2.5-fold, respectively. OP, an antioxidant and a bivalent metal chelator, blocked the HO-1 mRNA elevation induced either by hyperoxia or by the three ROI generators. In contrast to OP, N-acetylcysteine (NAC), an antioxidant and membrane-permeable reducing reagent, enhanced the HO-1 mRNA elevation induced by hyperoxia, although NAC inhibited the mRNA elevation induced by NaAsO2, CdCl2 and H2O2. These results indicate that oxygen tension regulates HO-1 gene expression and suggest that hyperoxia-specific and redox-sensitive regulators may be involved in hyperoxia-mediated HO-1 gene expression.

Alterations in the enzyme activity and protein contents of protein disulfide isomerase in rat tissues during fasting and refeeding

Protein disulfide isomerase (PDI) is an enzyme that participates in the formation of disulfide bonds. It is also known to be the subunits of some enzymes and the membrane-associated thyroid hormone-binding protein. In this study, we measured the quantitative distribution of PDI protein in rat tissues and examined the relationship between protein level and enzyme activity in PDI during fasting and refeeding. Western blotting with specific anti-PDI antiserum detected the PDI protein band of 55 kd. Among several tissues, liver contained the largest amount of PDI protein, followed by kidney and fat, in which one-third to one-fourth of the hepatic PDI protein existed. The PDI protein band was also detected in heart and muscle. Fasting for 3 days decreased PDI protein levels in rat liver by 40%; control levels were recovered after 3 days of refeeding. The same change was observed in kidney. PDI activity, measured by the scrambled ribonuclease method, did not show the parallel alteration to PDI protein level in liver and kidney. Isomerase activity decreased to 50% of control values during fasting, but did not recover by refeeding. Thyroidal status did not affect either PDI protein level or isomerase activity. These findings show that fasting and refeeding affect PDI protein and enzyme activity, and that PDI protein level does not always reflect PDI activity.

Oxygen tension regulates heme oxygenase-1 gene expression in mammalian cell lines

The gene expression of heme oxygenase-1 (HO-1) was studied in mammalian cell lines exposed to hyperoxia. Northern blot analysis demonstrated that hyperoxic exposure increased the HO-1 mRNA levels in various types of cells, including human hepatoma (HepG2) cells. This increase was time- and dose-dependent, and reversible. The HO-1 mRNA levels in HepG2 cells were increased to 2.3- and 4.2-fold of the control by hyperoxic exposure of 6 and 23 h, respectively. Cycloheximide and actinomycin D inhibited the increases in the HO-1 mRNA level produced by hyperoxia, indicating that response to hyperoxia is dependent on de novo protein synthesis and mRNA transcription. Antioxidants, desferrioxamine (DES) and o-phenanthroline (OP) partially inhibited the HO-1 mRNA elevation by hyperoxia. In addition to hyperoxia, sodium arsenite (NaAsO2), cadmium chloride (CdCl(2)) and hydrogen peroxide (H2O2), which are reactive oxygen intermediates (ROI) generators, increased the HO-1 mRNA level by 11-, 22- and 2.5-fold, respectively. OP, an antioxidant and a bivalent metal chelator, blocked the HO-1 mRNA elevation induced either by hyperoxia or by the three ROI generators. In contrast to OP, N-acetylcysteine (NAC), an antioxidant and membrane-permeable reducing reagent, enhanced the HO-1 mRNA elevation induced by hyperoxia, although NAC inhibited the mRNA elevation induced by NaAsO2, CdCl2 and H2O2. These results indicate that oxygen tension regulates HO-1 gene expression and suggest that hyperoxia-specific and redox-sensitive regulators may be involved in hyperoxia-mediated HO-1 gene expression.

Hypoxia-induced expression of phosphoglycerate mutase B in fibroblasts

Molecular oxygen (O2) is essential for aerobic organisms. Exposure of tissues or cells to hypoxia induces a variety of adaptive or pathogenic responses. To understand the mechanism and processes of cellular response to hypoxia, we exposed fetal rat lung fibroblasts to hypoxia (pO2 approximately 5 Pa) and screened the hypoxia-responsible gene by the differential display method. Exposure of the cells to hypoxia activated the phosphoglycerate mutase B (PGM-B) gene, resulting in the induction of PGM enzymatic activity, concomitant with elevations of PGM-B mRNA and protein levels. The mRNA level was elevated linearly with decreases in partial O2 pressure, indicating a 2-3-fold increase in these levels after 16 h hypoxia. Up-regulation of PGM mRNA by hypoxia was obvious after 8 h exposure, reached its peak after 16 h, persisting for 40 h and returned to the basal level after reoxygenation at 20% O2 for 16 h. Run-on and stability assays indicated that PGM-B expression is regulated mainly at the transcriptional step. These results suggest that the induction of PGM-B may contribute to the regulation of the glycolytic flux under reduced O2 tension and play a role in the adaptation of cells to hypoxia.

Stimulatory effect of calcitonin gene-related peptide on adrenocorticotropin release from rat anterior pituitary cells

In the present study, we examined the direct regulatory effect of rat calcitonin gene-related peptide (CGRP) on adrenocorticotropin (ACTH) release from rat cultured anterior pituitary cells. CGRP significantly increased ACTH release at concentrations of 10(-8)-10(-11) M. The ACTH release was gradually increased by CGRP concentrations lower than 10(-10) M, and was decreased at concentrations higher than 10(-9) M, presenting a bell-shaped dose-response curve. As well as having an additive effect on corticotropin-releasing factor-induced ACTH release, CGRP stimulated the accumulation of intracellular cAMP. The CGRP-induced ACTH release was inhibited by a protein kinase A inhibitor, suggesting that its stimulatory effect on the ACTH release was mediated via an adenylate-cyclase-protein kinase system. CGRP-like immunoreactive nerve fibers have been reported to innervate the anterior pituitary, so that the stimulatory effect of CGRP on the ACTH release suggests that this peptide may be involved in neural regulation of hormone secretion in the anterior pituitary.

Distribution and concentration of urocortin, and effect of adrenalectomy on its content in rat hypothalamus

We developed a specific and sensitive radioimmunoassay (RIA) for rat urocortin (rUcn) and investigated the tissue distribution and concentration of immunoreactive (IR-)Ucn in rats. Antiserum was obtained by immunizing rabbits with synthetic rUcn21-35 coupled with bovine thyroglobulin. 125I-[Tyr]18-rUcn19-37 was used as the tracer. The RIA detected synthetic rUcn1-40 as low as 0.4 fmol/tube, and did not cross-react with other corticotropin-releasing factor-related peptides. IR-Ucn was widely distributed in central nervous system, endocrine organs, and digestive system. Its concentration was highest in pituitary (11.0 +/- 1.36 pmol/g.w.w., mean +/- SEM, n=4). Reverse-phase HPLC revealed that hypothalamic IR-Ucn had similar chromatographic mobility to synthetic rUcn1-40. However, bilateral adrenalectomy did not influence the hypothalamic IR-Ucn content. Our results suggest that Ucn may play important roles in various tissues in normal rats, but not behave as a hypothalamic hypophysiotropic factor in mediating adrenocorticotropin secretion in adrenalectomized rats.

Effect of urocortin and its interaction with adrenocorticotropin (ACTH) secretagogues on ACTH release

We examined the effect of urocortin (Ucn) on the adrenocorticotropin (ACTH) release from cultured rat anterior pituitary cells and AtT 20 cells. Synthetic rat (r)Ucn was not soluble in 0.1 N HCl but soluble in alkaline solvents with diminished corticotropin-releasing activity. rUcn dissolved in 0.1 M sodium phosphate buffer as a stock solution maintained its bioactivity and had the equal corticotropin-releasing activity with rat/human corticotropin-releasing factor (r/hCRF). rUcn stimulated the adrenocorticotropin release via CRF-receptors accompanied by the additive effect with r/hCRF, the synergistic effect with arginine vasopressin and the dose-dependent inhibition of a potent CRF-receptor antagonist.

Case report: Clinical and virological analyses of a patient positive for hepatitis C virus-RNA by branched DNA assay but negative for anti-hepatitis C virus antibodies

Infection with hepatitis C virus (HCV) is usually diagnosed by the presence of antibodies against fusion proteins or peptides derived from different regions of the HCV genome. However, a subgroup of patients with HCV viraemia are seronegative for antibody against hepatitis C virus (anti-HCV) by conventional antibody assays. We analysed serum samples from a patient with liver cirrhosis who tested negative for anti-HCV by a second-generation assay, but positive for HCV-RNA by reverse transcription polymerase chain reaction (RT-PCR) and branched DNA signal amplification. To identify possible mutations that could explain the failure of detection of anti-HCV by second-generation assay, PCR-amplified DNA fragments of the core region derived from the serum were cloned and sequenced. Nucleotide (nt) and amino acid (aa) sequence analyses (nt 1-486, aa 1-162) showed no mutations revealing stop codons, frame-shifts, deletions or insertions, but the presence of two amino acid substitutions (aa 75 and 91) when compared with HCV-J, a prototype strain of genotype 1b isolated from a Japanese patient. One of these two mutations (aa 75) was situated in the second hydrophilic domain of the core peptide, but analysis of the hydropathy profile showed only a little change. The two mutations were identical to those identified in other Japanese HCV isolates. The serum immunoglobulin level and T and B cell counts were normal in our patient. Our data suggest that the absence of anti-HCV in this patient was not due to mutations of major epitopes of HCV. Low-dose prednisolone administration just after transfusion may have induced immunological tolerance against HCV in this patient.

Diurnal variation in serum remnant-like lipoproteins, platelet aggregation and fibrinolysis in healthy volunteers

Postprandial triglyceridemia and 'remnantemia' may better reflect the atherosclerotic risk than triglyceride (TG) levels in the fasting state. Recently, a new method was developed based on a monoclonal antibody recognizing an epitope distal to the carboxyl end of apo B48 which allows easy measurement of remnant-like lipoproteins (RLP). This study was performed in order to investigate RLP response to a standardized fat meal and establish a normal diurnal pattern of RLP in blood and compare it to platelet aggregation and fibrinolysis in healthy young men. We investigated 7 male volunteers (age range 18-23 years) who received a standardized fat meal (Othsuka Pharmaceutical Company, Japan) containing 32.9% lipids, 2.5% protein, 2.5% carbohydrate, 0.3% calcium and 0.1% phospholipids, and 74 mg/100 g cholesterol (C) at 7:30. The energetic value of this cocktail was 341 kcal/100 g. Area under curve (AUC) responses in TG, RLP-TG and RLP-C after the meal were as follows: for TG 28.66 +/- 8.94; for RLP-TG 17.54 +/- 5.55; for RLP-C 1.27 +/- 0.42 mg x dl-1 x h-1. These responses were correlated to each other. Surprisingly, collagen-induced platelet aggregation in whole blood was negatively related to RLP-C AUC. Fluctuation patterns of TG, RLP-TG and RLP-C concentrations during the day were remarkably similar, peaking in this particular group of subjects at 10:00-12:00 and at about 23:00, whereas cholesterol was decreasing late in the night and very early in the morning. This pattern was different from those of platelet aggregation and fibrinolysis parameters.

Urocortin expression in human pituitary gland and pituitary adenoma

Urocortin is a recently identified neuropeptide of the CRF family in the mammalian brain, but its expression in human tissue has been little studied. In this study, we examined urocortin expression in human anterior pituitary gland and pituitary adenomas by RIA, high performance liquid chromatography, immunohistochemistry, messenger ribonucleic acid (mRNA) in situ hybridization, and reverse transcriptase-PCR. Immunoreactive urocortin concentrations in normal pituitary tissue extract were 103.25 +/- 39.05 ng/g wet wt (mean +/- SEM; n = 4), and their levels were all significantly higher than those in other portions of central nervous system of the same subjects. High performance liquid chromatography analysis of human pituitary extract demonstrated a single peak corresponding to that of the expected chromatographic mobility of synthetic human urocortin-(1-40). Urocortin-immunoreactive cells were detected in the anterior pituitary gland. Neither urocortin-immunoreactive nerve fibers nor cells were detected in the posterior lobe. Immunostaining in serial mirror tissue sections revealed that 76.55 +/- 3.06% of urocortin-immunoreactive cells expressed GH immunoreactivity, whereas 22.25 +/- 3.02% and less than 1% of urocortin-immunoreactive cells expressed PRL and ACTH, respectively. mRNA hybridization signals of urocortin were also detected in urocortin-immunopositive pituitary cells. The reverse transcriptase-PCR analysis demonstrated a 145-bp RNA band corresponding to that of the expected length of urocortin in all cases of normal pituitary glands examined (n = 3). We also immunostained urocortin in 52 cases of human anterior pituitary adenomas, including GH-producing adenomas (n = 14), ACTH-producing adenomas (n = 13), PRL-producing adenomas (n = 11), and nonfunctioning hormonally inactive adenomas (n = 14). No urocortin immunoreactivity was detected in these adenoma cells, except for one case of GH-producing adenoma and one case of nonfunctioning adenoma. We also performed mRNA in situ hybridization in 27 adenomas. No hybridization signals were detected in these adenomas, except in two cases. The results described above indicated that urocortin is synthesized in human anterior pituitary cells and may play an important role in biological features of normal pituitary gland, possibly as an autocrine or a paracrine regulator

DNA topoisomerase II alpha and Ki-67 in human adrenocortical neoplasms: a possible marker of differentiation between adenomas and carcinomas

Cell kinetic information is valuable in evaluating the diagnosis and/or biologic behavior of various human neoplasms. Monoclonal antibody Ki-67 recognizes the cells other than G0 of the cell cycle. A cell cycle-related intranuclear protein, topoisomerase II alpha (topoII alpha), separates chromosomes at the end of mitosis. Its expression is mostly limited to the S to G2/M phases of the cell cycle. We studied cell proliferative activity in adrenocortical adenomas (n = 28), carcinomas (n = 17), and normal adrenal glands (n = 6) by immunohistochemical analysis of Ki-67 and topoII alpha to evaluate their value in the diagnosis of adrenocortical malignancy. We detected Ki-67 and topoII alpha immunohistoreactivity in the nuclei of each case we examined. There was a significant positive correlation (r = 0.927) between the Ki-67 and topoII alpha labeling indexes (LIs), the percentage of positive cells. In normal adrenal cortex and adenoma, the LIs for Ki-67 and topoII alpha were 0.48 +/- 0.16 and 0.44 +/- 0.15 for normal and 0.64 +/- 0.11 and 0.72 +/- 0.12 for adenoma, respectively, with no significant differences in the LIs of adenomas and normal adrenals. The Ki-67 and topoII alpha LIs in the carcinomas were 5.84 +/- 1.33 and 6.13 +/0 1.65, respectively; these LIs were significantly higher than the LIs of adenomas. Eleven of 17 carcinomas demonstrated topoII alpha and Ki-67 LIs of more than 2.5, whereas none of the adenomas did. The topoII alpha and Ki-67 LIs in carcinomas with metastasis (11.21 +/- 3.15 and 9.75 +/- 2.31 respectively; n = 7) were significantly higher than in those without metastasis (2.58 +/- 0.61 and 3.12 +/- 0.90, respectively; n = 10). This indicates that immunohistochemical analysis of Ki-67 and topoII alpha could help to differentiate carcinoma from adenoma in resected adrenocortical neoplasms and might predict aggressive biologic behavior in carcinomas.

Adrenal adenoma with bilateral adrenocortical nodular change in a patient with Cushing's syndrome

We report a 57-year-old male patient with adrenocorticotrophin (ACTH)-independent Cushing's syndrome and long-standing hypertension. Both abdominal computed tomographic scan and magnetic resonance imaging revealed bilateral adrenal enlargement with the presence of a tumour in the left adrenal. Marked uptake of 131I-6 beta-iodomethyl-19-norcholesterol was observed only in the left adrenal gland. Left adrenalectomy and biopsy of the right adrenal gland were subsequently performed. Histological examination revealed the presence of an adrenocortical adenoma in the left adrenal with multiple adrenocortical nodules in both left and right non-neoplastic adrenals. Peri- and intraadrenal arteries and arterioles demonstrated marked arteriosclerotic vascular changes. Immunoreactivity for several steroidogenic enzymes was present in the tumour and markedly diminished in the non-neoplastic adrenals. This patient with Cushing's adenoma is considered to have developed adrenocortical nodules in the nonneoplastic adrenal possibly as a result of localized compensatory overgrowth of adrenocortical cells in response to ischaemic changes due to arteriopathy. When examining patients with Cushing's syndrome and bilateral adrenal enlargement, the possibility of concomitant adenoma and adrenocortical nodule formation should also be considered in the differential diagnosis

Increases in the mRNA levels of gamma-glutamyltransferase and heme oxygenase-1 in the rat lung after ozone exposure

gamma-Glutamyltransferase (GGT) and heme oxygenase-1 (HO-1) are induced by chemical and physical stresses producing an oxidative burden on tissues and cells. Both enzymes are proposed to have an antioxidant role in protecting cells and tissues from oxidative burden. To explore the effects of ozone (O3), the major oxidant in photochemical smog, on the expression of GGT and HO-1 genes in the lung, we exposed rats to 0.4 ppm O3 for up to 7 days. After exposures, mRNA levels of GGT and HO-1 in the lung were measured by RNA blot analysis. Although a 1-day exposure did not change either GGT or HO-1 mRNA levels in the lung, both genes responded to prolonged exposure to O3. GGT mRNA was increased to 149% (P < 0.01) and 158% (P < 0.01) of the control by 3- and 7-day exposures, respectively. HO-1 mRNA was also elevated to 174% (P < 0.01) and 184% (P < 0.001) of the control after 3- and 7-day exposures, respectively. The elevation of GGT and HO-1 mRNA after prolonged exposure to O3 suggests that expression of these genes is not involved in the acute respiratory response, but in the recovery process from lung damage induced by O3.

High incidence of positive autoantibodies against thyroid peroxidase and thyroglobulin in patients with sarcoidosis

OBJECTIVE

Although abnormalities of the humoral immune system, such as increased immunoglobulin production, are known in sarcoidosis, the relationship between sarcoidosis and autoimmune disorders in uncertain. We studied the incidence of thyroid autoantibodies and the prevalence of Hashimoto's thyroiditis in patients with sarcoidosis.

PATIENTS AND MEASUREMENTS

Sixty-two patients with pulmonary sarcoidosis, diagnosed by a combination of clinical, radiographic and histological findings were studied. As controls, three groups of subjects aged 40 and over without a known history of thyroid disease (60 patients with pulmonary diseases other than sarcoidosis, 88 hospital employees and 82 company workers), were also analysed. Antibodies against thyroid peroxidase (TPO-Ab) and purified thyroglobulin (Tg-Ab) were measured by radioimmunoassay and antibodies against microsomal antigen (MCHA) and thyroglobulin (TGHA), by haemagglutination.

RESULTS

Seventeen of 62 patients (27.4%) had either positive TPO-Ab or Tg-Ab or both. All the patients with positive thyroid autoantibodies were of middle or advanced age, and the incidence of positive TPO-Ab/Tg-Ab in patients with sarcoidosis aged 40 and over was 54.5% in males, 32.4% in females and 37.8% overall. The prevalence was significantly higher in males compared to age-matched control males (0-7.7% in the controls), and in female patients was twice that found in controls (11.8-16.3%). Seven patients had Hashimoto's thyroiditis, indicating that the prevalence was 11-3%, and much higher than that previously reported.

CONCLUSIONS

The data show a remarkably high incidence of thyroid autoantibodies in patients of middle of advanced age with sarcoidosis, especially in males, and a higher prevalence of Hashimoto's thyroiditis than in previous reports.

Structural organization of the human prostaglandin EP3 receptor subtype gene (PTGER3)

Prostaglandin EP3 receptor subtype is a seven-membrane-spanning protein with multiple C-terminal tails generated by alternative mRNA splicing. We report here the structural organization of the human EP3 gene (PTGER3). The human EP3 gene spanned more than 80 kb and was composed of 10 exons separated by nine introns. Exon 1 and the 5' 180-bp portion of exon 2 (exon 2a) encoded the seven transmembrane domains and 10 amino acid residues of the cytoplasmic tail, which are common to all EP3 isoforms. The 3' 3461-bp portion of exon 2 (exon 2b) or combinations of exons 3-10 encoded the EP3 isoform-specific C termini and formed their 3'-untranslated regions by multiple fashions of alternative mRNA splicing. Exons 2b, 4, 6, and 10 contained polyadenylation sites. The EP3 gene formed nine distinct mRNAs encoding eight EP3 isoforms, two of which were novel ones tentatively designated EP3-V and EP3-VI. The transcription initiation sites of the human EP3 gene were mapped 227 to approximately 231 bp upstream of the ATG start codon. The 360-bp 5'-flanking region contained a TATA box-like sequence, a GC box, and several cis-acting regulatory elements. The present study provides insight into the molecular mechanisms underlying the prostanoid receptor family.

Introducing a point mutation identified in a patient with pituitary resistance to thyroid hormone (Arg 338 to Trp) into other mutant thyroid hormone receptors weakens their dominant negative activities

Clinical resistance to thyroid hormone (RTH) has been classified into generalized resistance to thyroid hormone (GRTH) and pituitary resistance to thyroid hormone (PRTH) types. Since similar mutations have been identified in tri-iodothyronine (T3) receptor (TR) beta gene in GRTH and PRTH, and since considerable overlap has been seen in the clinical manifestations in patients with GRTH and PRTH, two subtypes of RTH are now considered to be a continuous spectrum with the same genetic defect. A point mutation at amino acid Arg 338 to Trp (R338W) which we identified in a patient with PRTH is very interesting, since R338W has been found in several other patients with PRTH, raising the possibility that this mutation may tend to associate with a phenotype of PRTH. In our previous study, we found that R338W had relatively less impaired transcriptional potency, weaker dominant negative activity on various T3 response elements and poor homodimer formation, as compared with another GRTH mutant. In this study, to investigate the functional properties of R338W further, especially in terms of the relation between transcriptional activity and dimer formations, we introduced the R338W mutation into the mutant receptors, K443E and F451X, constructing the double mutants, R338W/K443E and R338W/ F451X. Both R338W/K443E and R338W/F451X showed negligible T3 binding and transcriptional activities. The dominant negative activities of K443E and F451X were, however, significantly weakened by introducing the R338W mutation. As a control, a double mutant G345R/K443E was constructed by introducing a point mutation, G345R, located in the same exon 9 as R338W, into the K443E mutant. Dominant negative activity did not differ between G345R/K443E and K443E. Homodimer formation was significantly reduced in the double mutants containing R338W, but not G345R. In summary, introducing the R338W mutation, but not G345R, into the mutant TR significantly weakened the dominant negative activity, despite further impairment of the T3 binding and transcriptional activities.

A population association study of four candidate genes (hexokinase II, glucagon-like peptide-1 receptor, fatty acid binding protein-2, and apolipoprotein C-II) with type 2 diabetes and impaired glucose tolerance in Japanese subjects

In order to define the major genetic factor(s) for the development of Type 2 (non-insulin-dependent) diabetes mellitus in Japanese subjects, a population association study of candidate genes involved in either glucose or lipid metabolism was carried out using microsatellite DNA polymorphisms. Each polymorphic locus near the four candidate genes, hexokinase II (HKII), glucagon-like peptide-1 receptor (GLP1R), fatty acid binding protein-2 (FABP-2), and apolipoprotein C-II (apoC-II) genes, were amplified by polymerase chain reaction (PCR) using 32P-labelled primers and each subject was genotyped for the association study. The HKII, GLP1R, FABP-2, and apoC-II polymorphisms exhibited 18, 10, 7, and 10 alleles, respectively. While polymorphism information contents (PICs) of these polymorphisms were relatively high, allele frequencies in these polymorphisms did not differ among subjects with Type 2 diabetes, impaired glucose tolerance (IGT) and non-diabetic controls. These results suggest that the HKII, GLP1R, FABP-2, and apoC-II genes are not the major inherited factors for the development of Type 2 diabetes or IGT in Japanese subjects, although minor contribution cannot be ruled out.

Effects of calcium antagonists on hepatic and systemic hemodynamics in awake portal hypertensive rats

The effects of the calcium antagonists diltiazem and nicardipine on portal pressure and splanchnic blood flow were studied in awake, unrestrained portal hypertensive rats. Portal hypertension was induced in rats by partial portal vein ligation. Hemodynamic measurements were done using the radiolabeled microsphere technique. In portal vein-ligated and sham-operated rats, intraarterial diltiazem and nicardipine reduced mean arterial pressure. No significant changes, however, were observed in portal pressure and cardiac index. In portal vein-ligated rats, diltiazem and nicardipine increased portal tributary blood flow. Portal tributary vascular resistance was also significantly decreased. The decrease in the hepatocollateral vascular resistance prevented an increase in portal pressure. In sham-operated rats, these changes were not observed. It is possible that the vascular responses to calcium antagonists are altered in portal vein-ligated rats. These findings demonstrate that the hemodynamic effects of calcium antagonists occur at two levels. First, the increase in portal tributary blood flow appears to be a selective effect on portal tributary vascular resistance. Secondly, the portal pressure does not increase in parallel with the increase in portal tributary blood flow because of a similar reduction in portocollateral vascular resistance.

A rare case of ectopic antidiuretic hormone-producing pancreatic adenocarcinoma: new diagnostic approach

We describe a 73-year old man with the syndrome of inappropriate antidiuretic hormone secretion (SIADH) due to an ectopic ADH-producing pancreatic adenocarcinoma. His laboratory findings showed marked hyponatremia, and the water load test showed uncontrolled ADH secretion. The imaging studies revealed pancreatic body cancer. Histological examination revealed an adenocarcinoma of the pancreas, which was positive for ADH immuno-staining. The ADH in the tumor extract was 53.3 pg/g wet weight. In attempt to diagnose ADH-production from the tumor, the ADH in his pancreatic juice was measured and found to be 2.1 pg/ml. We conclude that it is valid to measure the ADH in pancreatic juice to diagnose ectopic ADH production by tumors.

Urinary excretion of pyridinoline and deoxypyridinoline measured by immunoassay in hypothyroidism

OBJECTIVE

We measured pyridinium cross-links, markers of bone resorption, by an enzyme-linked immunosorbent assay (ELISA) in hypothyroid patients to see whether bone resorption was reduced in hypothyroidism and whether it increased with T4 treatment.

DESIGN AND PATIENTS

Eight hypothyroid patients, whose initial TSH levels were 268.1 +/- 87.7 mU/l (mean +/- SE), were treated with T4 (100 micrograms/day). Urinary excretion of pyridinium cross-links was assayed before and after T4 treatment.

MEASUREMENTS

Pyrilinks and Pyrilinks-D kits were used. The Pyrilinks assay measures free forms of pyridinoline and deoxypyridinoline together (PYD), while the Pyrilinks-D assay measures deoxypyridinoline (DPD) alone. The Pyrilinks reference ranges for normal subjects are 8-24nmol/mmol creatinine in males and 10-28nmol/mmol creatinine in normal premenopausal females. The DPD reference ranges obtained from normal men and women aged 40-50 years were 3.20 +/- 0.75 (mean +/- SD) nmol/mmol creatinine and 4.55 +/- 1.22 nmol/mmol creatinine, respectively.

RESULTS

The sensitivity of the assay was enhanced by simply using less diluted urine samples. Concentrations of both compounds of the urinary pyridinium cross-links were low in untreated hypothyroid patients and increased gradually as thyroid hormone status improved from hypothyroidism to euthyroidism. One month after treatment when the TSH levels in the patients were still as high as 74.4 +/- 44.5 mU/l, urinary PYD excretion has increased to 2.6 times the pretreatment level. When the TSH levels of the patients decreased below 10 mU/l, both PYD and DPD increased significantly to 3.8 and 3.3 times pretreatment values, respectively.

CONCLUSIONS

Although hyperthyroidism or excess treatment with thyroid hormone has been known to induce bone resorption, this is the first report that urinary excretion of pyridinium cross-links is reduced in hypothyroidism and is normalized by physiological thyroid hormone replacement.

The change in 123I-uptake between 3- and 24-hours is useful in predicting early response to methimazole in patients with Graves' disease

Some patients with Graves' disease respond well to anti-thyroid drug treatment but others do not. Factors determining the patient's responsiveness to the medical treatment are unclear, but the intrathyroidal iodine pool is believed one of the important factors. In this study, we found that delta radioactive iodine uptake (RAIU) (RAIU at 24 h-RAIU at 3 h) is useful in predicting early response to treatment with methimazole (MMI). Among 32 patients with Graves' disease, who were given 30 mg MMI as an initial dose, 11 patients responded quickly to MMI-treatment. Within one month, serum free T4 levels decreased to below the normal range in 6 patients (< 10.3 pmol/L) or decreased from beyond the highest level of the assay (> 125 pmol/L) to the normal range in 5 patients. When these rapid responders (group A) were compared with the remaining 21 patients who showed a more gradual response to MMI-treatment (group B), a different pattern of 123I-thyroid uptake was noted. RAIU at 3 h was significantly higher in group A than in group B, while RAIU at 24 h was similar in the two groups. As a result, rapid responders had a significantly lower delta RAIU value than gradual responders (-0.7 +/- 8.4% in group A, 14.2 +/- 8.2 in group B, P < 0.01). No significant difference was found between the two groups in various pre-treatment parameters such as severity and duration of thyrotoxicosis, the titer of TSH receptor antibodies (TRAb), frequency of positive antithyroglobulin antibodies (TGHA), urinary excretion of iodine and thyroid volume. The incidence of positive antithyroid microsomal antibodies (MCHA) was higher in group A than in group B, and thyroid ultrasonography showed a tendency to low echogenicity in group A. delta RAIU was negatively correlated with the reduction in the serum free T4 level during the first two weeks after MMI-treatment was initiated (r = -0.60, P < 0.01). Moreover, delta RAIU correlated positively with the biological half-life of the intrathyroidal iodine, calculated in a different series of 24 patients with Graves' disease who received radioisotope treatment (r = 0.54, P < 0.01). The low delta RAIU value is considered to reflect the rapid turnover of the intrathyroidal iodine, and may be related to the small intrathyroidal iodine pool. delta RAIU is useful in predicting early responsiveness of patients with Graves' disease to MMI-treatment.

Effects of acute and chronic ethanol administration on hepatic hemodynamics and hepatic oxygen consumption in awake rats

BACKGROUND/AIMS AND METHODS

We investigated the effects of acute and chronic ethanol administration on hepatic hemodynamics and hepatic oxygen delivery and consumption in awake rats, using the radiolabeled microsphere technique and measurement of oxygen content in blood.

RESULTS

Acute oral and intraarterial ethanol administration produced a significant increase in liver blood flow and hepatic oxygen delivery, but resulted in a significant (25-41%) decrease in hepatic oxygen consumption. These changes lasted up to 5 h after ethanol administration. At 24 h, hepatic oxygen consumption was significantly increased by 33% over control values. During withdrawal in rats fed liquid diets containing alcohol for 6 weeks, hepatic oxygen delivery was maintained at the same level as control pair-fed rats, while hepatic oxygen consumption increased by 28%. Further, in abstinent rats, acute ethanol readministration resulted in a 41% increase in hepatic oxygen delivery but a 32% decrease in hepatic oxygen consumption.

CONCLUSIONS

These findings demonstrate, in awake animals, a biphasic response of hepatic oxygen consumption following acute ethanol administration and an increase in hepatic oxygen consumption following chronic ethanol intake. Furthermore, acute ethanol treatment reduced hepatic oxygen consumption in spite of an increase in hepatic oxygen delivery.