Microsatellite alterations in various sarcomas in Japanese patients

To determine the usefulness of microsatellite analysis in the differential diagnosis of various sarcomas, we investigated microsatellite alterations at 12 microsatellite loci by polymerase chain reaction and electrophoresis in 39 Japanese patients with sarcomas. The sarcomas were: osteosarcoma, Ewing's sarcoma, chondrosarcoma, liposarcoma, leiomyosarcoma, epithelioid leiomyosarcoma, rhabdomyosarcoma, synovial sarcoma, and malignant fibrous histiocytoma. We also examined ten leiomyomas to contrast with leiomyosarcoma. No microsatellite instability (MSI) or loss of heterozygosity (LOH) were found in Ewing's sarcoma, chondrosarcoma, epithelioid leiomyosarcoma, malignant fibrous histiocytoma, and leiomyoma. Only three patients, one each with liposarcoma, leiomyosarcoma, and synovial sarcoma, manifested MSI, whereas, osteosarcoma, liposarcoma, leiomyosarcoma, rhabdomyosarcoma, and synovial sarcoma manifested LOH, with an incidence of 43%, 14%, 86%, 20%, and 75%, respectively. Interestingly, three patients showed unusual patterns of LOH, probably due to intratumoral heterogeneity. Kaplan-Meier analysis revealed that LOH on 11p was predictive of poor prognosis in osteosarcoma. The low incidence of MSI indicates that MSI is not necessary for neoplastic transformation in sarcomas. However, the very high incidence of LOH in leiomyosarcoma indicates that microsatellite analysis may serve for the differential diagnosis of leiomyosarcoma versus leiomyoma. Microsatellite analysis may also predict prognosis in osteosarcoma.

Impaired beta-adrenoceptor mediated venodilation in patients with diabetes mellitus

AIMS

We investigated whether venoconstriction by alpha-adrenoceptor stimulation, and venodilation by beta-adrenoceptor stimulation and nitroglycerin are altered in patients with diabetes mellitus (DM).

METHODS

Eight male patients with non insulin-dependent DM and eight age-matched control subjects were included. The patients had neither hypertension nor hyperlipidaemia. Noradrenaline (1 to 512 ng min-1 ), isoprenaline (1 to 256 ng min-1 ) and nitroglycerin (0.5 to 128 ng min-1 ) were infused into a dorsal hand vein and its diameter was measured using a linear variable differential transformer.

RESULTS

The venoconstricting response to noradrenaline and the venodilating response to nitroglycerin in DM patients were similar to those in control subjects, while the venodilation by isoprenaline was significantly (P<0.05) smaller in DM patients than in control subjects at the dose of 32 ng min-1 or more [32 ng min-1: 11.5% vs 29.8% (DM vs control subjects), 64 ng min-1: 19.0% vs 40.1%, 128 ng min-1: 25.2% vs 49.0%, 256 ng min-1: 34.3% vs 56.7%].

CONCLUSIONS

These data suggested that venoconstriction by alpha-adrenoceptor stimulation and venodilation by nitroglycerin are not altered, whereas venodilation by beta-adrenoceptor stimulation might be impaired in patients with DM.

Loss of heterozygosity in actinic keratosis, squamous cell carcinoma and sun-exposed normal-appearing skin in Japanese: difference between Japanese and Caucasians

Actinic keratosis (AK) has been considered to be a precursor of squamous cell carcinoma (SCC). However, based on epidemiological and molecular studies, it has become questionable to regard AK as a precancerous lesion. We analyzed 37 AKs and 14 sporadic SCCs using six microsatellite markers in order to elucidate if any genetic instability or loss of heterozygosity (LOH) was implicated in tumorigenesis and progression of non-melanocytic skin tumor. Microsatellite instability (MSI) was not found in any of the AKs or SCCs indicating that genetic instability has little implication in the tumorigenesis of sporadic non-melanocytic skin tumor. LOH was found in seven of 37 lesions of AK, but in only one of 14 lesions of SCC. The significantly lower frequency of LOH than that previously reported in Caucasians suggested that the molecular pathogenesis of AKs and SCCs might be different between Japanese and Caucasians. The higher frequency of LOH in AKs than in SCCs in the present study supported the previous epidemiological and molecular studies that AK was not likely to proceed to SCC. LOH was also demonstrated in histologically normal-appearing skin in three cases suggesting that genetic alteration occurs before histological change appears in the sun-exposed skin.

Activation of a cyanobacterial adenylate cyclase, CyaC, by autophosphorylation and a subsequent phosphotransfer reaction

The CyaC protein, a cyanobacterial adenylate cyclase, has a unique primary structure composed of the catalytic domain of adenylate cyclase and the conserved domains of bacterial two-component regulatory systems, one transmitter domain and two receiver domains. In the present work, CyaC was produced in Escherichia coli as a histidine-tagged recombinant protein and purified to homogeneity. CyaC showed ability to autophosphorylate in vitro with the gamma-phosphate of [gamma-32P]ATP. CyaC derivatives were constructed by site-directed mutagenesis in which the highly conserved phosphorylation sites in the transmitter domain (His572) and receiver domains (Asp60 or Asp895) were replaced by glutamine and alanine residues, respectively. After autophosphorylation of the CyaC derivatives, the chemical stabilities of the phosphoryl groups bound to the derivatives were determined. It was found that His572 is the initial phosphorylation site and that the phosphoryl group once bound to His572 is transferred to Asp895. The enzyme activities of the CyaC derivatives defective in His572 or Asp895 were considerably reduced. Asp895 is phosphorylated by acetyl [32P]phosphate, a small phosphoryl molecule, but Asp60 is not. Acetyl phosphate stimulates adenylate cyclase activity only when Asp895 is intact. These results suggest that the phosphorylation of Asp895 is essential for the activation of adenylate cyclase and that Asp60 functions differently from Asp895 in regulating the enzyme activity.

Melanin pigmented oncocytic metaplasia of the nasopharynx

A 64-year-old man presented with a history of discomfort of the throat of a few weeks' duration. Nasoscopic examination revealed multiple small, brown pigmentations at the left suprapharynx, the base of the left nasal cavity and the pharyngeal openings of the auditory tube on both sides. Microscopically, the lesion showed a glandular pattern of oncocytic epithelium with abundant pigmented granules and melanophages in the surrounding stroma. Immunohistochemically, the dendritic cells in the basal layer were positive for S-100 protein. Electron microscopic study revealed numerous fully melanized melanosomes and hypertrophied mitochondria in the oncocytic cells. Oncocytic cells do not produce melanin for themselves, melanin granules apparently being transferred from the adjacent dendritic cells to the oncocytic cells.

An adenylate cyclase, Cya1, regulates cell motility in the cyanobacterium Synechocystis sp. PCC 6803

The cyanobacterium Synechocystis sp. PCC 6803 contained two genes, cya1 and cya2, encoding putative adenylate cyclases. The wild type cells are motile, whereas the disruption mutants of cya1, but not cya2, were immotile. Disruption of the cya1 gene also caused reduction of cellular cAMP level. The cya1 mutant cells regained motility when cAMP was added exogenously.

Stability of immobilized thermolysin in organic solvents

Various factors affecting the stability of thermolysin immobilized by cross-linking with glutaraldehyde were elucidated, particularly in the water-immiscible organic solvents such as ethyl acetate and tert-amyl alcohol. The main reason for enzyme inactivation in water-immiscible organic solvents was found to be autolysis in the water phase, which may surround the enzyme immobilized inside the support. By contrast, in water-miscible organic solvents thermal denaturation was the predominant cause of enzyme inactivation. Courses of inactivation were expressed by second-order kinetics in the initial stage, after which inactivation proceeded at a slower rate. The extent of autolysis was found to strongly depend on the kind of organic solvent, the water content, and type of support and these dependencies were explained by the difference in the amount and state of water inside the support. Thermolysin was immobilized onto Amberlite XAD-7 as a compact aggregate inside the support which may increase the stability of the enzyme. Finally, it was shown that the stability of the immobilized enzyme could be correlated with the logP value for water-miscible organic solvents and with the solubility of water for water-immiscible organic solvents.

Effect of amezinium metilsulfate on the finger skin vasoconstrictor response to cold stimulation and venoconstrictor response to noradrenaline

Orthostatic hypotension can be caused by an inadequate vasoconstrictor response. The effects of amezinium on vasoconstrictor response to sympathetic stimulation and to exogenous noradrenaline were investigated and compared with those of midodrine. In 8 healthy men, the following experiments were performed after a single oral dose of 10mg of amezinium, 2mg of midodrine or a placebo. First, finger-tip blood flow (FTBF) was recorded using a laser Doppler flowmeter before and during the contralateral hand cooling and a reduction ratio of FTBF was calculated as an index of the vasoconstrictor response. Second, dose-response curves to increasing doses (1-512ng/min) of noradrenaline infused locally to the dorsal hand vein were determined using a linear variable differential transformer. The reduction ratio of FTBF was significantly increased (p<0.05) by amezimium [placebo, 75.9 +/- 9.8(mean +/- SD)%; amezinium, 85.1 +/- 7.9%; midodrine, 78.1 +/- 9.3%]. The infusion rate of noradrenaline producing a half-maximum venoconstriction was significantly decreased (p<0.05) by amezinium (placebo, 40.6 +/- 33.9 ng/min; amezinium, 21.0 +/- 21.3 ng/min; midodrine, 33.2 +/- 31.5 ng/min). These findings indicate that amezinium increases the vasoconstrictor response to sympathetic stimulation and to noradrenaline in normal subjects, and this mechanism might contribute to the improvement by amezinium of the symptoms of orthostatic hypotension.

Effects of a long-term inhalation of fragrances on the stress-induced immunosuppression in mice

The aim of this study was to determine the effects of the long-term application of various fragrances on the suppression of immune response induced by high-pressure stress in mice. The immune response was analyzed based on plaque-forming cell (PFC) count, using mice sensitized with sheep red blood cells. The decreased PFC involving thymic involution induced by high-pressure stress in mice was restored by exposing the stressed mice to tuberose, lemon, oakmoss and labdanum for 24 h following exposure to stress. The decreased PFC and thymic involution from stress were restored by exposure to lemon and oakmoss, but not to tuberose and labdanum when the mice were exposed to those fragrances continuously for 3 weeks before the stress was given, followed by exposure to the same fragrances for 24 h after the stress. The decreased PFC and thymic involution from stress were restored by exposure to lemon and labdanum for 24 h after the stress, but not to tuberose over 3 weeks before the stress was given. These data suggest that the neuroimmunomodulatory effects of fragrances may be affected by tolerance depending on the kinds of fragrances in the case of a long-term application.

Collision tumor of cutaneous malignant melanoma and basal cell carcinoma

An extremely rare case of a collision tumor of malignant melanoma (MM) and basal cell carcinoma (BCC) located in the temporal scalp of a 78-year-old male is reported. Microscopic examination revealed a collision tumor consisting of the nodular type, Clark's level IV MM, and a pigmented BCC. The tumor was studied by immunohistochemistry and was analyzed for point mutations of codons 12 and 61 of H-ras, K-ras and N-ras oncogenes. Tumor cells of the MM were positive for S-100 protein, HMB-45 and vimentin, but negative in the BCC. The malignant melanoma possessed an activating A to T transversion in codon 61 of N-ras gene, which is the code for leusine instead of glutamine. This is the first report of ras oncogene mutation in such a collision tumor. MM and BCC are clearly different in terms of histological, immunohistochemical and ras gene mutation analyses. These findings support the view that the association of MM and BCC in this collision tumor is a chance occurrence.

Heart rate variability during chemical thoracic sympathectomy

BACKGROUND

Chemical thoracic sympathectomy (CTS) resulted in profound bradycardia in a patient with severe post-therapeutic neuralgia. To clarify the cause of this bradycardia, the authors evaluated heart rate variability using a Poincaré plot, which is a scatter diagram of the current R-R interval plotted against the R-R interval immediately preceding it, in this patient and in others scheduled for CTS or mandibular block (MB).

METHODS

Twenty-three patients were scheduled for CTS (n = 13, CTS group) and for MB (n = 10, MB group). Heart rate and the SD of the R-R interval variabilities spreading along the x axis (SDRR) and perpendicularly along the diagonal line of the Poincaré plot (SDdeltaRR) were evaluated before, just after, and 1 h after the block.

RESULTS

Neither group had significant changes in heart rate. The MB group showed no significant change in the SD(RR):SDdeltaRR ratio. In the CTS group, however, the SD(RR):SDdeltaRR ratio decreased significantly from 1.72+/-0.20 to 1.23+/-0.11 just after CTS. The previous patient, who had a high SD(RR):SDdeltaRR ratio of 3.45 before CTS, exhibited severe bradycardia (22 beats/min).

CONCLUSIONS

The SD(RR):SDdeltaRR ratio decreased after CTS without any significant concomitant change in heart rate. The decrease in the SD(RR):SDdeltaRR. ratio indicates a reduction of cardiac sympathetic activity. However, CTS in patients having high SD(RR):SDdeltaRR ratios can result in profound bradycardia.

Morphology and distribution of nerve endings in the human triangular fibrocartilage complex

We studied the morphology and distribution of nerve endings in the human triangular fibrocartilage complex using both silver staining and immunohistochemical staining using a protein specific to nerve fibres. Free nerve endings were found in the ulnar side of the triangular fibrocartilage complex, especially in the ulnar collateral ligament, meniscus homologue and the adjacent collagen fibre area of the peripheral part of the ulnar side of the articular disc. Meissner's and Krause's corpuscles were observed in the ulnar collateral ligament and meniscus homologue. The fact that free nerve endings were observed in the meniscus homologue and adjacent collagen fibre area of the peripheral part of the ulnar side of the articular disc suggests that this disc may be a source of wrist pain. The presence of nerve end bulbs in the triangular fibrocartilage complex also suggests a possible role for corpuscles as mechanoreceptors.

The expressions of mRNAs for interleukin-6 (IL-6) and the IL-6 receptor (IL-6R) in the rat hypothalamus and midbrain during restraint stress

Over the past few years, it has been reported that physical and psychological stress elevate plasma interleukin-6 (IL-6), and that neural cells can produce IL-6 and have receptors for IL-6 (IL-6R). However, it is unknown whether IL-6 plays a role in regulating the functions of neural cells in response to stress. We demonstrated recently, using the reverse transcriptase-polymerase chain reaction (RT-PCR), that the levels of mRNAs for IL-6 and IL-6R in the rat brain are changed by restraint stress for four hours. In the present study, we investigated the expression of mRNAs for IL-6 and the IL-6R in the rat hypothalamus and midbrain during restraint stress. After rats had been restrained for 10, 30, 60, 120 or 240 min, the hypothalamus and midbrain were removed immediately and levels of IL-6 mRNA and of IL-6R mRNA in these regions were determined by RT-PCR. The expression of mRNAs for IL-6 and IL-6R in both regions was reduced after short-term (30-60 min) restraint stress and tended to return toward the control level after 120 min restraint stress. After long-term (240 min) restraint stress, the level of IL-6 mRNA was significantly increased in the midbrain, while the level of IL-6R mRNA was significantly reduced in both regions. These findings suggest that the need for IL-6 might decline after short-term restraint stress and, moreover, that the synthesis and secretion of IL-6 might be enhanced and IL-6 might be needed as a neurotrophic factor in the midbrain after long-term stress.

Long-term survival of patients with stage IV gastric carcinoma

BACKGROUND

Survival of patients with Stage IV (based on general rules established by the Japanese Research Society for Gastric Cancer) gastric carcinoma often is unfavorable. Among patients with a poor prognosis, a few do survive > 5 years. The authors examined pathologic and biologic features of tumors of long term survivors.

METHODS

The authors analyzed data from 442 patients with Stage IV gastric carcinoma, including 20 surviving for > 5 years after gastrectomy (Group A) and 422 who died of gastric carcinoma within 5 years (Group B). Mutant p53 was immunohistochemically stained using the monoclonal antibody PAb1801. Proliferative activity was estimated by argyrophilic nuclear organizer region (AgNOR) staining and proliferating cell nuclear antigen (PCNA) staining.

RESULTS

Group A had smaller and more localized tumors than Group B (P < 0.05 and P < 0.01, respectively). Lymphatic or venous invasion and peritoneal dissemination were less frequent in Group A than in Group B (P < 0.01). Abnormalities of p53 expression were found in 3 of the 14 tumors in Group A (21%), a value significantly lower than the 58 of 118 tumors in Group B (49%; P < 0.05). AgNOR count and percentage of PCNA labeling were not significantly different between Groups A and B. A multivariate analysis showed that lymph node dissection, liver metastasis, gastric resection, venous invasion, and tumor size were independent prognostic factors.

CONCLUSIONS

Even in patients with Stage IV gastric carcinoma, radical gastrectomy and extensive lymph node dissection can lead to long term survival. The authors believe that combination analysis of pathologic features and p53 overexpression predict length of survival for patients with Stage IV gastric carcinoma.

A novel mature B-cell line (DOBIL-6) producing both parathyroid hormone-related protein and interleukin-6 from a myeloma patient presenting with hypercalcaemia

A novel human EBV-negative B-cell line, designated DOBIL-6, was established from a patient with non-secretary myeloma. The DOBIL-6 cell has cytoplasmic gamma protein and expresses CD19, 20, 38, 45RO, VLA-4 and PCA-1 antigens, but lacks CD10, 45RA and VLA5 antigens. Chromosome analysis showed that DOBIL-6 cells had many complex structural abnormalities, including t(11;4) (q13;q32), which were consistent with that of the fresh tumour cells. Interestingly, abundant interleukin-6 (IL-6) and parathyroid hormone-related protein (PTHrP) accumulated in the culture supernatant of DOBIL-6 cells. Hypercalcaemia and splenomegaly associated with plasma cell proliferations which resulted in the expansion of the light zones in the follicles were observed in DOBIL-6 transplanted nude mice. RT-PCR analysis detected mRNA for PTHrP, and IL-6 as well as its receptor (GP80) in DOBIL-6 cells. Treatment of the DOBIL-6 cells with neutralizing anti-IL-6 antibody inhibited their growth in a dose-dependent manner, whereas the addition of exogenous IL-6 stimulated it in serum-depleted conditions. These findings suggest that both IL-6 and PTHrP are produced in DOBIL-6 cells, and that IL-6 promotes its growth by an autocrine mechanism. Since IL-6 is known to stimulate not only the growth of B-cell neoplasms but also osteoclastic bone resorption by cooperating with PTHrP, this simultaneous production of IL-6 and PTHrP might be synergistically linked and play a role in the development of hypercalcaemia of the patient. The DOBIL-6 cell is a useful tool to clarify the mechanism of hypercalcaemia associated with mature B-cell neoplasms.

Effects of dopamine on veins in humans: comparison with noradrenaline and influence of age

OBJECTIVE

To compare the venoconstricting effect of dopamine with that of noradrenaline and to investigate the influence of age on the responsiveness to dopamine in human subjects.

METHODS

In eight young and eight elderly male subjects, increasing doses of dopamine or noradrenaline were infused into a dorsal hand vein and its diameter was measured using a linear variable differential transformer.

RESULTS

There was no significant difference between the maximum venoconstriction (Emax) for dopamine and that for noradrenaline. The infusion rate to induce 50% of Emax (ED50) for dopamine in the young and elderly subjects was 363 ng x min(-1) and 352 ng min(-1), and the ED50 for noradrenaline was 40.7 ng min(-1) and 43.8 ng x min(-1), respectively. Neither in the Emax nor in the ED50 for these drugs were there significant differences between the young and elderly subjects.

CONCLUSION

The venoconstricting effect of dopamine is 5-20 times less than that of noradrenaline, and aging does not influence the responsiveness to dopamine and noradrenaline in human subjects.

A novel thyroid transcription factor is essential for thyrotropin-induced up-regulation of Na+/I- symporter gene expression

The stimulation of iodide (I-) transport by TSH in FRTL-5 thyroid cells is partly due to an increase in Na+/I- symporter (NIS) gene expression. The identification of a TSH-responsive element (TRE) in the NIS promoter and its relationship to the action of thyroid transcription factor-1 (TTF-1) on the promoter are the subjects of this report. By transfecting NIS promoter-luciferase chimeric plasmids into FRTL-5 cells in the presence or absence of TSH, we identify a TRE between -420 and -370 bp of the NIS 5'-flanking region. Nuclear extracts from FRTL-5 cells cultured in the absence of TSH form two groups of protein-DNA complexes, A and B, in gel mobility shift assays using an oligonucleotide having the sequence from -420 to -385 bp. Only the A complex is increased by exposure of FRTL-5 cells to TSH or forskolin. The addition of TSH to FRTL-5 cells can increase the A complex at 3-6 h, reaching a maximum at 12 h. FRTL-5, but not nonfunctioning FRT thyroid or Buffalo rat liver (BRL) cell nuclear extracts, form the A complex. The TSH-increased nuclear factor in FRTL-5 cells interacting with the NIS TRE is distinct from TTF-1, thyroid transcription factor-2, or Pax-8, as evidenced by the absence of competition using oligonucleotides specific for these factors in gel shift assays. Neither is it the nuclear protein interacting with cAMP response element. The TRE is in the upstream of a TTF-1-binding site, -245 to -230 bp. Mutation of the TRE causing a loss of TSH responsiveness also decreases TTF-1-induced promoter activity in a transfection experiment. The formation of the A complex between FRTL-5 nuclear extracts and the NIS TRE is redox-regulated. In sum, TSH/cAMP-induced up-regulation of the NIS requires a novel thyroid transcription factor, which also appears to be involved in TTF-1-mediated thyroid-specific NIS gene expression.

Regulation of major histocompatibility (MHC) class II human leukocyte antigen-DR alpha gene expression in thyrocytes by single strand binding protein-1, a transcription factor that also regulates thyrotropin receptor and MHC class I gene expression

The single strand binding protein (SSBP-1) is a positive regulator of TSH receptor gene expression and binds to an element with a GXXXXG motif. The S box of the mouse major histocompatibility class II gene has multiple GXXXXG motifs and can also bind SSBP-1. The S box is one of four highly conserved elements on the 5'-flanking region of class II genes that are necessary for interferon-gamma (IFNgamma) to overcome the normally suppressed state of the gene and induce aberrant class II expression. In this report we show that SSBP-1, when overexpressed in FRTL-5 thyroid cells, is a positive regulator of human leukocyte antigen (HLA)-DR alpha class II gene expression, as is IFNgamma or the class II trans-activator (CIITA). This is evidenced by increased exogenous promoter activity, increased endogenous RNA levels, and increased endogenous antigen expression after transfecting full-length SSBP-1 complementary DNA together with a HLA-DR alpha promoter-reporter gene chimera into TSH-treated FRTL-5 thyroid cells whose endogenous SSBP-1 levels are low. IFNgamma reverses the ability of TSH to decrease endogenous SSBP-1 RNA levels. Also, whereas SSBP-1 transfection does not cause any increase in IFNgamma-induced exogenous promoter activity, transfection of SSBP-1 and CIITA additively increases endogenous class II RNA levels to levels measured in cells treated with IFNgamma. Further, competition studies show that SSBP-1 binding is necessary for formation of the double strand protein/DNA complexes that are seen in electrophoretic mobility shift assays when the class II 5'-flanking region is incubated with extracts from IFNgamma-treated FRTL-5 cells and that have been previously associated with IFNgamma-induced aberrant class II expression. These data suggest that SSBP-1 is involved in the action of IFNgamma to overcome the normally suppressed state of the class II gene; it functions together with CIITA, whose expression is independently increased by IFNgamma. The effect of SSBP-1 as a positive regulator of class II promoter activity is lost in cells maintained without TSH, in which endogenous SSBP-1 RNA levels are already high in the absence of aberrant class II gene expression. These data suggest that high levels of endogenous SSBP-1 are insufficient to cause aberrant class II expression, but, rather, TSH or IFNgamma treatment additionally modulates the cell, albeit differently, such that transfected or endogenous SSBP-1, respectively, can express its positive regulatory activity. The effect of TSH is consistent with reports indicating that TSH enhances the ability of IFNgamma to increase class II gene expression despite the fact IFNgamma increases endogenous SSBP-1 to only the same levels as in cells untreated with TSH. Finally, the effect of SSBP-1 as a positive regulator is lost when GXXXXG motifs, which exist on both the coding and noncoding strands of the S box, are mutated. Consistent with this, mutation and oligonucleotide competition studies show that GXXXXG motifs are necessary for either strand of the S box to bind protein/DNA complexes containing SSBP-1 in FRTL-5 cell extracts or to bind to recombinant SSBP-1. They also suggest that the SSBP-1-binding sites on either strand of the HLA-DR alpha S box are functionally distinct. We conclude from these data that the positive regulatory action of SSBP-1 on class II gene expression involves GXXXXG motifs on each strand of the highly conserved S box of the class II 5'-flanking region. As SSBP-1 is modulated by IFNgamma and is involved in class I and TSH receptor as well as class II gene expression in FRTL-5 cells, the sum of the data supports the hypotheses that common transcription factors regulate all three genes, and their altered activities may contribute to the development of autoimmunity.

Comparison of venodilatory effect of nicardipine, diltiazem, and verapamil in human subjects

OBJECTIVE

Venodilatory effects of calcium antagonists have not been fully investigated, especially in human subjects. The present study was undertaken to compare the direct venodilatory effects of nicardipine, diltiazem and verapamil using the dorsal hand-vein technique.

METHODS

In eight healthy male subjects, increasing doses (0.001, 0.01, 0.1, 1 and 10 microg x min(-1)) of these drugs and saline alone were infused, on four separate occasions, into the dorsal hand vein preconstricted with noradrenaline, and its diameter was measured by a linear-variable differential transformer.

RESULT AND CONCLUSIONS

Diltiazem caused significant venodilation at a dose of 0.01 microg x min(-1) or more, while verapamil and nicardipine only caused this effect at 1 microg x min(-1) or more. The potency of the effect was diltiazem > verapamil > nicardipine. The venodilation at a dose of 1 microg x min(-1) was 41.7%, 16.2% and 8.5%, respectively, for each drug. These findings indicate that the venodilatory effect of diltiazem is larger than that of verapamil and nicardipine in human subjects.

Simultaneous dislocation of the scaphoid and hamate bones

We report a rare case of simultaneous dislocations of the hamate and scaphoid in an 18-year-old boy. Despite the extensive damage to the wrist joint, the functional results of open reduction and suture of intercarpal ligaments have been satisfactory, without carpal instability and degenerative osteoarthritis.

Major histocompatibility class II HLA-DR alpha gene expression in thyrocytes: counter regulation by the class II transactivator and the thyroid Y box protein

Aberrant expression of major histocompatibility complex (MHC) class II proteins on thyrocytes, which is associated with autoimmune thyroid disease, is mimicked by gamma-interferon (gamma-IFN). To define elements and factors that regulate class II gene expression in thyrocytes and that might be involved in aberrant expression, we have studied gamma-IFN-induced HLA-DR alpha gene expression in rat FRTL-5 thyroid cells. The present report shows that class II expression in FRTL-5 thyrocytes is positively regulated by the class II transactivator (CIITA), and that CIITA mimics the action of gamma-IFN. Thus, as is the case for gamma-IFN, several distinct and highly conserved elements on the 5'-flanking region of the HLA-DR alpha gene, the S, X1, X2, and Y boxes between -137 to -65 bp, are required for class II gene expression induced by pCIITA transfection in FRTL-5 thyroid cells. CIITA and gamma-IFN do not cause additive increases in HLA-DR alpha gene expression in FRTL-5 cells, consistent with the possibility that CIITA is an intermediate factor in the gamma-IFN pathway to increased class II gene expression. Additionally, gamma-IFN treatment of FRTL-5 cells induces an endogenous CIITA transcript; pCIITA transfection mimics the ability of gamma-IFN treatment of FRTL-5 thyroid cells to increase the formation of a specific and novel protein/DNA complex containing CBP, a coactivator of CRE binding proteins important for cAMP-induced gene expression; and the action of both gamma-IFN and CIITA to increase class II gene expression and increase complex formation is reduced by cotransfection of a thyroid Y box protein, which suppresses MHC class I gene expression in FRTL-5 thyroid cells and is a homolog of human YB-1, which suppresses MHC class II expression in human glioma cells. We conclude that CIITA and TSH receptor suppressor element binding protein-1 are components of the gamma-IFN-regulated transduction system which, respectively, increase or decrease class II gene expression in thyrocytes and may, therefore, be involved in aberrant class II expression associated with autoimmune thyroid disease.

Daily variation in an intensity of kaolin-induced writhing reaction in mice

The daily variation in an intensity of kaolin-induced writhing reaction was examined in mice kept under conditions of light; 07:00 - 19:00 and dark; 19:00 - 07:00. The number of writhes was counted for 30 minutes after a single intraperitoneal injection of kaolin at 00:00, 02:00, 04:00, 06:00, 08:00, 10:00, 12:00, 14:00, 16:00, 18:00, 20:00 and 22:00. The number of writhes showed a daily variation with a peak at 18:00 and a trough at 06:00. The intensity of writhing reaction was significantly reduced by pretreatment with the bradykinin B1 (Des-Arg9-[Leu8]-BK) and B2 (icatibant) receptor antagonists. Significant daily variation in this parameter was still observed in the group with the B1 antagonist, but disappeared in the B2 antagonist-treated group. These results suggest that the kaolin-induced writhing reaction shows the daily variation with a peak at the end of the resting period and a trough at the end of the active period. The B2 receptor mediated stimuli appears to be involved in this phenomenon.

Activated Ki-ras enhances sensitivity of ceramide-induced apoptosis without c-Jun NH2-terminal kinase/stress-activated protein kinase or extracellular signal-regulated kinase activation in human colon cancer cells

The activation of c-Jun NH2-terminal kinase (JNK)/stress-activated protein kinase (SAPK) and/or extracellular signal-regulated kinase (ERK) is involved in ceramide-induced apoptosis in certain cells. To examine the relationship between activated Ki-ras-mediated signals and ceramide-induced apoptosis in human colon cancer cells, JNK/SAPK and ERK activity, as initiated by ceramide, was examined in HCT116, which has a mutation of Ki-ras at codon 13, and HCT116-derived clones, HKe-3 and HKh-2, in which activated Ki-ras was disrupted through gene targeting. In HKe-3 and HKh-2, the activity of JNK/SAPK increased significantly within 60 min following C2 ceramide stimulation, and some apoptosis followed. In contrast, C2 ceramide caused a marked apoptosis in HCT116, but activation of JNK/SAPK was not observed. C2 ceramide did not activate ERK in any of the cell lines. These results suggest that activated Ki-ras contributes to the sensitivity of ceramide-induced apoptosis without JNK/SAPK or ERK activation and that other signaling pathways involved in ceramide-induced apoptosis may be present in human colon cancer cells.