The putative phospholipase C inhibitor U73122 and its negative control, U73343, elicit unexpected effects on the rabbit parietal cell

In order to elucidate the role of phospholipase C (PLC) in gastric acid secretion, we used U73122, a commonly employed specific inhibitor of receptor-mediated PLC, and its negative control, U73343. Although 10 microM U73122 inhibited the increase in [Ca++]i induced by U46619 in rabbit platelets, Ca++ transients in the rabbit parietal cells elicited by histamine and carbachol were both resistant to the inhibitor. U73122 augmented the acid secretion of isolated gastric glands stimulated by histamine, carbachol and dbcAMP, possibly through its indirect Ca++-releasing effect on the intracellular calcium store. U73122 potently inhibited K+-p-nitrophenylphosphatase without affecting overall H+,K+-ATPase activity. On the other hand, the negative control, U73343, strongly inhibited the acid secretion stimulated by all agonists tested. The inhibitory effect was also evident on digitonin-permeabilized glands and on the proton gradient of gastric vesicles. U73343 itself is not a proton pump inhibitor, so it was considered a protonophore. In conclusion, the widely used PLC-inhibitor, U73122, and its negative control, U73343, are both useless as tools for analyzing the role of PLC in rabbit parietal cells. The former is ineffective on gastric PLC and works as an intracellular calcium releaser, and the latter works as a protonophore.

Role of ATP-sensitive potassium channels in brain stem circulation during hypotension

The basilar artery and its branch arterioles dilate actively in response to a marked decrease in blood pressure and maintain cerebral blood flow (CBF) to the brain stem. We tested the hypothesis that ATP-sensitive potassium (KATP) channels play a role in the autoregulatory responses of the brain stem circulation in vivo. In anesthetized Sprague-Dawley rats, local CBF to the brain stem was determined with laser-Doppler flowmetry, and diameters of the basilar artery and branch arterioles were measured through a cranial window during stepwise hemorrhagic hypotension. During topical application of 10(-6) and 10(-5) mol/l of glibenclamide, a selective KATP-channel blocker, the lower limit of CBF autoregulation shifted upward to 60-75 from 30-45 mmHg in the vehicle group. Glibenclamide significantly impaired the dilator response of small arterioles (baseline diameter 45 +/- 2 microns) throughout hypotension (P < 0.03) but did not impair the dilatation of the basilar artery (247 +/- 3 microns) or large arterioles (99 +/- 4 microns). Thus KATP channels appear to play an important role in the regulation of CBF to the the brain stem during hypotension by mediating the compensatory dilatation of small arterioles. In contrast, these channels may not be a major regulator of the vascular tone of larger arteries during hypotension.

Calcium oscillations in single cultured Chinese hamster ovary cells stably transfected with a cloned human cholecystokinin (CCK)B receptor

In Chinese hamster ovary cells stably expressing the cloned human cholecystokinin (CCK)B/ gastrin receptor, cholecystokinin octapeptide (CCK-8) evoked increases in [Ca2+]i monitored by digitized video imaging of fura-2 fluorescence ratios. At concentrations around 10 pM, CCK-8 elicited [Ca2+]i oscillations, which were blocked by elimination of extracellular Ca2+, by a phospholipase C inhibitor, U-73122, by a protein kinase C inhibitor, H7, as well as by phospholipase A2 (PLA2) inhibitors, ONO-RS-082 and aristolochic acid. At higher concentrations, CCK-8 induced a single biphasic [Ca2+]i rise consisting of a large peak followed by a lower sustained plateau, while the response turned into [Ca2+]i oscillation when the extracellular Ca2+ was eliminated or a PLA2 inhibitor was included. CCK-8 stimulated the release of arachidonic acid, and this was inhibited by aristolochic acid. Arachidonic acid caused an increase in [Ca2+]i which was dependent upon extracellular Ca2+. These results suggest that the activation of PLA2 might be involved, at least in part, in the Ca2+ influx that maintains the sustained plateau phase of [Ca2+]i as well as the [Ca2+]i oscillation when CCKB receptors are stimulated.

Effects of prenatal exposure to 5-bromo-2'-deoxyuridine on reproductive function in male mouse offspring

The effect of the halogenated pyrimidine analog 5-bromo-2'-deoxyuridine (BrdU), on reproductive functions of male mouse offspring treated prenatally was studied. BrdU was administered intraperitoneally to pregnant ICR mice at 100 mg/kg/d on days 8 through 13 of gestation, and at 100 or 200 mg/kg/d on days 14 through 18 of gestation. Dams were allowed to deliver naturally. Male offspring were aged for 10 weeks and then cohabited with untreated female mice for assessment of reproductive performance. Histopathologic examination of the testes and pituitary, sperm analysis, and determination of plasma testosterone concentrations of offspring at 12 weeks of age were performed. In the subsequent study, pregnant ICR mice were treated with 200 mg BrdU/kg on day 10, 13, or 15 of gestation. The embryos or fetuses were obtained from mothers from 6 to 48 h after treatment, and pyknotic cells in the ventricular zone of the telencephalon were counted. There was a significant decrease in body weight gain of offspring in all of the BrdU-treated groups. A marked decrease in copulation rate was noted in the male offspring of dams treated on days 8 through 13 of gestation, whereas no significant decreases in copulation and fertility rates were found in the male offspring of dams treated on days 14 through 18 of gestation. Neither histopathologic examination of testes nor sperm analyses revealed adverse effects of this compound, whereas cysts in the pars distalis of the pituitary were observed in the male offspring treated on days 8 through 13 of gestation. Dilatation of the lateral ventricles was also observed in male offspring at 12 weeks of age in the group treated on days 8 through 13 of gestation. The incidence of pyknotic cells in the ventricular zone of embryos was markedly increased 24 h after treatment on day 10 of gestation. These results indicate that the impaired fertility of the male offspring of dams treated with BrdU on days 8 through 13 of gestation may be due to the effects of BrdU exposure on central nervous system function that result in loss of libido rather than to the direct effects of this compound on the male reproductive organs.

An ATP-sensitive potassium channel activator reduces infarct volume in focal cerebral ischemia in rats

ATP-sensitive potassium channels are activated under hypoxic or ischemic conditions. The effects of ATP-sensitive potassium channel activators on cerebrovasculature and cerebral blood flow (CBF) are not well understood. We examined the effect of the ATP-sensitive potassium channel activator Y-26763 on focal cerebral ischemia in rats. In 24 spontaneously hypertensive rats, either Y-26763 (24 micrograms/kg) or vehicle was given by intracarotid infusion over 60 min, starting 30 min before photochemically induced thrombotic occlusion of the middle cerebral artery. CBF was measured by laser-Doppler flowmetry in the peri-ischemic penumbral cortex. Although Y-26763 lowered systemic blood pressure by 13 mmHg, the infarct volume assessed 3 days after the occlusion was significantly smaller in the Y-26763-treated group (n = 12, 71.2 +/- 22.0 mm3) than in the control group (n = 12, 94.7 +/- 20.4 mm3, P = 0.013). Y-26763 did not affect CBF before or after occlusion compared with CBF values of the control group. The results are consistent with the view that the activation of the ATP-sensitive potassium channel is neuroprotective in focal cerebral ischemia.

Glucocorticoids and cyclosporine induce apoptosis in mitogen-activated human peripheral mononuclear cells

Induction of apoptosis by immunosuppressive agents such as glucocorticoids (GCs) and cyclosporine (CsA) in cultured lymphoid cells has been suggested. However, there are few studies which demonstrate the induction of apoptosis by these agents in the activation process of human peripheral blood mononuclear cells (PBMCs). Here we show that potent immunosuppressive GCs and CsA induce apoptosis in concanavalin A (con A)-activated human PBMCs. In this study, GCs and CsA suppressed human PBMC-blastogenesis when activated by con A in a dose-dependent manner, where healthy PBMCs treated with > 100 ng/ml of each immunosuppressive agent exhibited a DNA-ladder structure in electrophoretic analysis. In three chronic renal failure (CRF) patients, dose-dependency of the PBMC-apoptosis induction was confirmed by our quantification of fragmented DNA using ELISA. Furthermore, the enrichment of DNA fragmentation was significantly associated with the rate of PBMC-blastogenesis when treated with GCs or CsA (r = -0.466, P < 0.01). These results suggested that suppression of the mitogen-induced PBMC-blastogenesis by the immunosuppressive agents should be correlated with the induction of apoptosis.

Expression of basic fibroblast growth factor (FGF-2)-associated with tumour proliferation in human pancreatic carcinoma

Basic fibroblast growth factor (FGF-2) is one of the mitogens that facilitate epithelial proliferation and angiogenesis. We analysed the expression of FGF-2 and type I fibroblast growth factor receptor (FGFR1) in 20 selected cases of human pancreatic carcinoma (PC) in connection with proliferation of tumour cells and intratumour endothelial cells (ECs), using immunohistochemistry and in situ hybridization (ISH). By FGF-2 immunostaining, tumour cells were strongly positive in 10 cases (50%). By FGFR1 immunostaining, stromal fibroblasts and ECs occasionally showed positive staining. Tumour cells in 12 cases (60%) were strongly positive. Expression of FGF-2 mRNA, as examined by ISH, was detected in 12 cases (60%) of PC, and its distribution pattern was similar to that of FGF-2 immunostaining. We divided these cases into two groups according to the result of FGF-2 immunostaining, and examined the Ki67 labelling indices of tumour cells and ECs between these two groups. These two proliferative indices were significantly higher in FGF-2-positive than in FGF-2-negative cases (P<0.05, P<0.05, respectively). These findings suggest that the expression of FGF-2 in PC is strongly associated with the proliferation of tumour cells and ECs and its increased expression may give tumour a growth advantage.

Differential contribution of two serine residues of wild type and constitutively active beta2-adrenoceptors to the interaction with beta2-selective agonists

1. We have studied the difference in receptor binding activity between partial and full beta2-adrenoceptor agonists and the abilities of the agonists to interact with Ser204 and Ser207 in the fifth transmembrane region of the beta2-adrenoceptor, amino acid residues that are important for activation of the beta2-adrenoceptor. 2. In the binding study with [125I]-iodocyanopindolol, the Ki values of (+/-)-salbutamol, (+/-)-salmeterol, TA-2005 and (-)-isoprenaline for the beta2-adrenoceptor expressed in COS-7 cell membranes were 3340, 21.0, 12.0 and 904 nM, respectively. The beta1/beta2 selectivity of these agonists was in the order of (+/-)-salmeterol (332 fold) > TA-2005 (52.8) > (+/-)-salbutamol (6.8) > (-)-isoprenaline (1.1), and the beta3-/beta2-adrenoceptor selectivity of these agonists was in the order of TA-2005 (150 fold) > (+/-)-salmeterol (88.6) > (+/-)-salbutamol (10.4) > (-)-isoprenaline (3.2). 3. The maximal activation of adenylyl cyclase by stimulation of the beta1-, beta2- and beta3-adrenoceptors by TA-2005 was 32, 100 and 100% of that by (-)-isoprenaline, respectively, indicating that TA-2005 is a full agonist at the beta2- and beta3-adrenoceptors and a partial agonist at the beta1-adrenoceptor. (+/-)-Salbutamol and (+/-)-salmeterol were partial agonists at both beta1- (8% and 9% of (-)-isoprenaline) and beta2- (83% and 74% of (-)-isoprenaline) adrenoceptors. 4. The affinities of full agonists, TA-2005 and (-)-isoprenaline, were markedly decreased by substitution of Ala for Ser204 (S204A) of the beta2-adrenoceptor, whereas this substitution slightly reduced the affinities of partial agonists, (+/-)-salbutamol and (+/-)-salmeterol. Although the affinities of full agonists for the S207A-beta2-adrenoceptor were decreased, those of partial agonists for the S207A-beta2-adrenoceptor were essentially the same as for the wild type receptor. 5. The constitutively active mutant (L266S, L272A) of the beta2-adrenoceptor had an increased affinity for all four agonists. The affinities of full agonists were decreased by substitution of Ser204 of the constitutively active mutant, whereas the degree of decrease was smaller than that caused by the substitution of the wild type receptor. Although the affinities of (+/-)-salbutamol and (+/-)-salmeterol for the S207A-beta2-adrenoceptor were essentially the same as those for the wild type beta2-adrenoceptor, the affinities of (+/-)-salbutamol and (+/-)-salmeterol for the constitutively active beta2-adrenoceptor were decreased by substitution of Ser207. 6. These results suggest that Ser204 and Ser207 of the wild type and constitutively active beta2-adrenoceptors differentially interacted with beta2-selective agonists.

Synthesis biological evaluation of alkyl, alkoxy, alkylthio, or amino-substituted 2,3-dihydro-1,5-benzothiazepin-4(5H)-ones

2,3-Dihydro-1,5-benzothiazepin-4(5H)-ones substituted with an alkyl, alkoxy, alkylthio, hydroxy, or amino group on the fused benzene ring of the 1,5-benzothiazepine skeleton were synthesized and their vasodilating, antihypertensive, and platelet aggregation-inhibitory activities were investigated. (-)-cis-3-Acetoxy-5-[2-(di-methylamino) ethyl]-2,3-dihydro-8-methyl-2-(4-methylphenyl)-1,5-benzothiazepin- 4(5H)-one ((-)-13e) was selected for further studies as a potent inhibitor of platelet aggregation.

Cytotoxic and antiplatelet aggregation principles from Aglaia elliptifolia

Two related 1H-2,3,3a,8b-tetrahydrocyclopenta[b]benzofurans, aglafolin (1a) and rocaglamide (2), isolated from the stems of Aglaia elliptifolia, showed significant cytotoxicity in six cancer cell lines. Aglafolin (1a) was also found to completely block platelet aggregation caused by arachidonic acid and platelet-activating factor at 100 microM and 2 ng/mL, respectively.

ME-3407, a new antiulcer agent, inhibits acid secretion by interfering with redistribution of H(+)-K(+)-ATPase

ME-3407 is a newly developed antiulcer drug that markedly promoted the healing of acetic acid-induced chronic ulcers in rats presumably due to potent inhibition of acid secretion. ME-3407 and its metabolites, the sulfoxide of which was preserved, produced dosedependent inhibition of aminopyrine accumulation by rabbit gastric glands stimulated by any agonist, suggesting that the site of their action was downstream from the production of second messengers. Although one of the metabolites, EF-4025, showed some inhibitory effects on functional activities of H(+)-K(+)-ATPase, ME-3407 itself was not a proton pump inhibitor. ME-3407, but not omeprazole, inhibited the stimulation-associated redistribution of H(+)-K(+)-ATPase from microsomes into the apical membranes in addition to delocalizing ezrin, a putative F-actin-membrane linker, from apical plasma membrane. ME-3407 and EF-4025 inhibited myosin light chain kinase (MLCK) and protein kinase A activities. Because another MLCK inhibitor, wortmannin, showed the same properties as ME-3407, i.e., inhibition of aminopyrine accumulation, inhibition of stimulation-associated redistribution of H(+)-K(+)-ATPase, and abnormal distribution of ezrin, we hypothesize that MLCK is one of the potential targets for the drug. We conclude that ME-3407 is a promising drug for treating peptic ulcers, as well as a useful tool for studying mechanisms of parietal cell activation, especially related to the recruitment and recycling of the proton pump.

Effects of a novel, potent benzothiazepine Ca2+ channel antagonist, DTZ323, on guinea-pig ventricular myocytes

The effects of a 1,5-benzothiazepine derivative, (+)-cis-3-(acetyloxy)-5-[2-[[2-(3,4-dimethoxyphenyl)ethyl]-methyla mino]ethyl]-2,3-dihydro-2-(4-methyoxyphenyl)-1,5-benzothiazepine-4 (5H)-one (DTZ323), on membrane currents were investigated in guinea-pig ventricular myocytes using the whole-cell patch-clamp technique. DTZ323 suppressed the L-type Ca2+ channel currents (I[Ca(L)]) more selectively than the T-type Ca2+ channel and the Na+ channel currents. DTZ323 inhibited I[Ca(L)] in a use- and a voltage-dependent manner with 24 times higher potency than that of diltiazem. Rate of recovery of I[Ca(L)] from the conditioned block by DTZ323 was faster compared with diltiazem and verapamil, and was steeply dependent on the holding potential at resting membrane potential range in ventricular myocytes (-90 to -60 mV). Our results suggest that DTZ323 is a selective Ca2+ channel antagonist, the most potent among the 1,5-benzothiazepine Ca2+ channel antagonists, and that the voltage- and use-dependent effect of DTZ323 on I[Ca(L)] is due to the steep voltage dependence of the rate of dissociation from the cardiac L-type Ca2+ channels.

Aggressive natural killer (NK) cell lymphoma: report of a pediatric case and review of the literature

We report a rare pediatric case of aggressive natural killer (NK) cell lymphoma, characterized by acute onset hepatosplenomegaly and respiratory distress, and infiltration by large granular lymphocytes with the phenotype of CD3-CD16-CD56+. The patient has remained in complete remission after short-pulse intensive chemotherapy, and myeloablative therapy followed by allogeneic bone marrow transplantation. We compare our case with 7 other children with NK cell leukemia reported from other institutions.

Relationship between desensitization and downregulation of beta-adrenoceptors in cardiac tissues after prolonged in vivo infusion of T-0509, a beta 1-adrenoceptor agonist

To examine the contribution of beta-adrenoceptor (beta AR) downregulation to desensitization of beta ARs by chronic administration of a beta AR agonist, we compared the adenylyl cyclase (AC) activities in two kinds of cardiac ventricular membranes with decreased available beta ARs: one was derived from rats infused with a selective beta 1 AR agonist, T-0509 [(-)-(R)-1-(3,4-dihydroxyphenyl)- 2-[(3,4-dimethoxyphenethyl)-amino]ethanol hydrochloride], in vivo (40 micrograms/kg/hr, s.c. for 6 days); and the other was obtained from treatment of control membranes with an irreversible beta AR antagonist, bromoacetyl alprenolol methane (BAAM). T-0509 infusion decreased the densities of beta 1 ARs and beta 2 ARs by 26% and 32%, respectively, and reduced the maximal isoproterenol-stimulated AC activity by 53%. The amount of Gs alpha and Gi alpha proteins in the membranes was not significantly changed by T-0509 infusion. To make preparations that mimic the T-0509-induced downregulation, we treated the control membranes with 100 nM BAAM in vitro. The BAAM treatment decreased the Bmax value of [125I]iodocyanopindolol for beta 1 ARs and beta 2 ARs by 29% and 36%, respectively, whereas it reduced the maximal effect of isoproterenol on AC activity only by 37%. These results suggest that downregulation of beta ARs cannot fully account for the desensitization by chronic treatment of T-0509 and that other mechanism(s) can play a significant role in the loss of responsiveness.

[A case of hypertrophic spinal pachymeningitis]

A 79-year-old woman was admitted to our hospital complaining of gait disturbance. At the time of admission, she had incomplete monoparesis of the left lower extremity, with a sensory level of T6. MR images showed a thickened dura at the C6-T4 vertebral levels. The thickened dura showed low intensities on T1- and T2-weighted images, and was homogeneously enhanced by Gd-DTPA. Hypertrophic spinal pachymeningitis (HSP) was suspected, and laminectomy was performed from T2 to T3. The thickened dura was found and partially resected. Microscopically, the diagnosis was HSP. Steroid therapy was initiated after surgery. Postoperatively, the patient's physical status and radiographic images improved. The etiology of HSP is not clear in most cases. It is difficult to diagnose radiographically, although MR imaging can help differentiate it from other disorders. T1- and T2-weighted images of HSP show low intensities, and the T1-weighted image is homogeneously enhanced by Gd-DTPA. Treatment is early decompressive surgery with possible excision of the involved dura. Steroid therapy was effective in our case.

Glucocorticoid-resistance in peripheral-blood lymphocytes does not correlate with number of affinity of glucocorticoid-receptors in chronic renal failure patients

Glucocorticoid (GC) resistance in patients with chronic renal failure (CRF) seriously impairs successive GC therapy after renal transplantation. We examined the relationship between GC-receptor (GC-R) parameters in peripheral-blood mononuclear cells (PBMC) and PBMC resistance to GC in 21 CRF patients and 18 healthy subjects. Each subject group was divided into two subgroups according to PBMC sensitivity to prednisolone in a mitogen assay procedure; i.e., sensitive (IC50 < 381 ng/mL) and resistant (IC50 > 381 ng/mL) groups. In healthy subjects, the mean GC-R Bmax and Kd in quiescent PBMC of the GC-sensitive group were 2.89 +/- 1.23 fmol/10(6) cells and 4.00 +/- 2.24 nM, respectively. The Bmax in these subjects significantly increased to 6.61 +/- 2.02 (257.7 +/- 107.8%) after 24 h stimulation with concanavalin A (p < 0.01), while the Kd change was not significant. The GC-R Bmax and Kd in quiescent PBMC of the GC-resistant group were 5.33 +/- 1.37 fmol/10(6) cells and 3.20 +/- 1.39 nM, respectively. Both of these parameters, however, did not change significantly after mitogen stimulation. There was a significant negative correlation between IC50S of prednisolone and increase-ratios (post/pre ratio) of Bmax after mitogen stimulation (p < 0.05). In CRF patients, Bmax and Kd in quiescent PBMC of the GC-sensitive group were 6.04 +/- 2.35 fmol/10(6) cells and 3.49 +/- 1.72 nM, respectively, while those in PBMC of the GC-resistant group were 5.13 +/- 2.31 fmol/10(6) cells and 4.04 +/- 1.62 nM, respectively. The Bmax and Kd were not significantly changed after mitogen stimulation in both subgroups of CRF. Moreover, in contrast to healthy subjects, there was no correlation between IC50 and GC-R parameters in CRF. We concluded that, in healthy subjects, decreased PBMC capacity to amplify GC-R numbers in response to mitogen is correlated with GC resistance, whereas in CRF patients the resistant mechanism is not correlated with GC-R parameters. An unknown event might be involved in GC-resistance of CRF.

High-affinity binding of DTZ323, a novel derivative of diltiazem, to rabbit skeletal muscle L-type Ca++ channels

A novel derivative of diltiazem (1,5-benzothiazepine Ca++ antagonist), DTZ323, 3-(acetyloxy)-5-[2-[[2-(3,4-dimethoxyphenyl)ethyl]-methylamino]eth yl]-2,3-dihydro-2-(4-methoxyphenyl)-1,5-benzothiazepine-4(5H)-one, was characterized by radioligand binding experiments with rabbit skeletal T-tubule membranes in terms of the affinity and the selectivity to the binding sites for the three classical calcium antagonists, such as dihydropyridines, phenylalkylamines and benzothiazepines. DTZ323, like diltiazem and clentiazem, exhibited complete and concentration-dependent inhibition of d-cis-[3H]diltiazem binding to the membrane with a slope factor close to unity. Ki values indicated that DTZ323 (Ki = 6.6 +/- 0.6 nM, mean +/- S.E., n = 4) was 48 times and 9 times more potent than diltiazem and clentiazem, respectively. DTZ323 partially inhibited the specific binding of a dihydropyridine ligand, (+)-[3H]PN200-110, at 37 degrees C. The equilibrium saturation study showed that DTZ323 reduces the affinity for the (+)-[3H]PN200-110 binding in a concentration-dependent manner with a slight decrease in the density of the binding sites. DTZ323 also inhibited the specific binding of a phenylalkylamine ligand, (-)-[3H]D888, completely as did diltiazem. DTZ323 (1 microM) had no effect on the dissociation rate of d-cis-[3H]diltiazem at 2 degrees C, whereas 30 microM verapamil increased the dissociation rate, which suggested that DTZ323 inhibits the specific binding of d-cis-[3H]diltiazem in a manner similar to other competitive ligands for the benzothiazepine binding site. These results indicate that DTZ323 is a selective ligand for the 1,5-benzothiazepine binding site with the highest affinity among the diltiazem derivatives.

Ca2+-dependent membrane bound protein fraction from rabbit gastric mucosa contains a protein whose histidyl residue is phosphorylated

We found an autophosphorylated protein with a molecular weight of 40 kDa (p40) in the crude annexin fraction of rabbit gastric mucosa, i.e., the materials released by EGTA from the membrane fraction obtained in the presence of Ca2+. This protein was enriched in chief cells in the gastric glands, and also found in the heart and the liver by Western blotting. The protein bound to phenyl-Sepharose in the presence of Ca2+ and showed extremely basic nature. The phosphorylation site of p40 was considered to be histidyl residue based on the stability to the various agents, the synthesizing activity of ATP from ADP, and the results of phosphoamino acid analysis. The autophosphorylation of p40 was augmented several tenth fold by GDP, Ras, myelin basic protein, or H1 histone at micromolar range. The phosphorylated form was rapidly dephosphorylated in the presence of cold ATP, succinate, and CoA, suggesting that p40 has succinyl-CoA synthetase activity. In fact, a peptide fragment from p40 showed a striking homology with the alpha subunits of succinyl-CoA synthetases from Escherichia coli, Dictyostelium discoideum, and rat liver. These results suggest that p40 is extramitochondrial alpha subunit of succinyl-CoA synthetase or its homologue.

Behavioral characteristics of micrencephalic rats in high and low shuttlebox avoidance lines

Rats of two lines, selectively bred for high and low shuttlebox avoidance response, and unselected line of the Sprague-Dawley (SD) rats were given an IP injection of methylnitrosourea (MNU) at 5 mg/kg on day 13 of gestation. Their offspring, all with micrencephaly, were subjected to the Biel maze, shuttlebox avoidance, and wheel cage activity tests during 6 to 9 weeks of age. Results from micrencephalic rats were compared with those obtained from untreated control offspring of the respective lines. The MNU-treated offspring in each line made more errors than controls in the Biel maze, and showed similar avoidance responses to controls in the shuttlebox test. Line differences in effects of MNU treatment were observed in elapsed time in the straight channel, extinction of shuttlebox avoidance responses, and activity in the wheel cage. These line differences in effects of MNU treatment may be related to control baseline levels of behavior in which the three lines differed widely, and suggest that the behavioral effects of prenatal MNU treatment vary in rats depending on the lines used.

Inhibition of tumor necrosis factor-alpha and interleukin-1-beta production by beta-adrenoceptor agonists from lipopolysaccharide-stimulated human peripheral blood mononuclear cells

The effects of beta-adrenoceptor agonists (beta-agonists) on the production of tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta) and interleukin-8 (IL-8) by lipopolysaccharide (LPS)-stimulated human peripheral blood mononuclear cells (PBMCs) were investigated. The beta-agonists, procaterol, clenbuterol, fenoterol and terbutaline, inhibited TNF-alpha and IL-1 beta production in a concentration-dependent manner, whereas they had no effect on IL-8 production. TNF-alpha production was inhibited more potently than IL-1 beta. Dibutyryl cyclic AMP (dbcAMP) also inhibited the production of TNF-alpha and IL-1 beta, but not IL-8. TNF-alpha production was almost completely inhibited by dbcAMP, whereas IL-1 beta production appeared to be partially refractory even at the highest concentration examined. Both procaterol and theophylline elevated cAMP levels in LPS-stimulated PBMCs, but the effect of procaterol was limited. The inhibition of TNF-alpha and IL-1 beta production by procaterol was additively potentiated with theophylline. dl-Propranolol, a beta-adrenoceptor antagonist, abrogated the inhibition of TNF-alpha and IL-1 beta production by procaterol. These results indicate that beta-agonists inhibit the production of proinflammatory cytokines, such as TNF-alpha and IL-1 beta, by elevating intracellular cAMP levels. These properties of beta-agonists might be beneficial in the treatment of allergic inflammation.

Phalangeal intraosseous well-differentiated osteosarcoma of the hand

A case of intraosseous well-differentiated osteosarcoma in one phalanx of the hand is reported. A 78-year-old man noticed swelling in the little finger of his right hand approximately 7 years before referral. Imaging disclosed a tumour with a "ground glass" appearance and irregular mottled calcification occupying almost all of the phalanx marrow and suggested slight invasion into the soft tissue. Open biopsy suggested a diagnosis of well-differentiated fibroblastic osteosarcoma. The finger and its metacarpal bone were amputated and a tumour measuring 3.5 x 2.2 x 2.0 cm and with an indistinct soft tissue margin was found in the bone marrow. Histologically, the tumour was composed of fibroblastic cells with few mitoses, and neoplastic bone formation was apparent. Although the tumour appeared to be a fibrous dysplasia, the presence of nuclear atypia, hypercellularity, and the absence of a typical woven bone pattern in addition to the soft tissue invasion indicated otherwise. Ultrastructural examination showed focal myofibroblastic differentiation, and immunohistochemistry revealed smooth muscle actin, vimentin, osteocalcin, osteonectin and MIBI in the tumour cells. This ultrastructural and immunohistochemical study is believed to be the first detailed report of an intraosseous well-differentiated osteosarcoma of phalangeal bone.