Signal transduction pathway for anterior-posterior development in Drosophila

In Drosophila, the establishment of embryonic polarity along the anterior-posterior axis of the egg is determined by the activity of maternal gene products that accumulate during oogenesis. Amongst these are the Bicoid, the Nanos, and the terminal class gene products, some of which are oncoproteins involved in signal transduction for the formation of terminal structures in the embryo. Several signal transduction pathways have been described in Drosophila, and this review explores the potential of oncogene studies using one of those pathways - the terminal class signal transduction pathway - to better understand the cellular mechanisms of proto-oncogenes that mediate cellular responses in vertebrates including humans.

Canine pancreatic juice stimulates the release of secretin and pancreatic secretion in the dog

A secretin-releasing factor (SRF) was found in canine pancreatic juice that increases plasma secretin and stimulates pancreatic secretion in rats, suggesting that a positive feedback mechanism may be involved in the regulation of pancreatic secretion. In the present study, we investigated to determine whether or not SRF releases endogenous secretin and stimulates exocrine pancreatic secretion in conscious dogs. Fresh pancreatic juice was collected from four dogs by intravenous administration of secretin at 0.5 microg. kg(-1). h(-1) and CCK at 0.2 microg. kg(-1). h. The juice was boiled for 10 min at 100 degrees C. Experiments were carried out in phase I of spontaneous cycle of interdigestive pancreatic secretion. The testing solutions were infused intraduodenally in separate experiments: NaHCO3 solution (0.1 M, 4.5 ml/min, 60 min), a corn oil (Lipomul, 2 ml/min, 10 min), boiled pancreatic juice (BPJ, 4.5 ml/min, 60 min), and mixture of BPJ and Lipomul. Pancreatic secretion of fluid and bicarbonate was significantly increased by either BPJ or a mixture of BPJ and Lipomul (34- and 31-fold or 41- and 38-fold, respectively). Plasma secretin level also significantly increased by 164.7 +/- 13.4% and 223.1 +/- 35.0%, respectively, from basal concentration of 1.7 +/- 0.5 pM. In contrast, neither bicarbonate solution nor Lipomul influenced the plasma secretin level or pancreatic secretion. In addition, when Lipomul was incubated with BPJ, no fatty acid was produced. Thus the increased pancreatic secretion in the dog infused with a combination of BPJ and Lipomul was caused by SRF in BPJ, which released endogenous secretin. Moreover, the increases by BPJ of both plasma secretin level and bicarbonate secretion were completely blocked by intravenous administration of an antisecretin antibody in these dogs. The observations suggest that SRF in pancreatic juice exerts a positive feedback effect on exocrine pancreatic secretion that is mediated by the release of secretin in the interdigestive state in dogs.

No association of alpha-2 macroglobulin gene five-nucleotide deletion with AD in Taiwan Chinese

The alpha-2 macroglobulin five-nucleotide deletion (A2M-2) allele frequency was not significantly higher in the AD group than the control group (0.062 versus 0.101, p > 0.1). The odds ratio for AD in individuals with the A2M-2 allele was 0.582 (95% CI, 0.25 to 1.40). These results do not support the association between A2M-2 and AD in the Chinese population, although the allele frequency of A2M-2 is lower than that found in the Caucasian population. Therefore, A2M-2 might not be a significant risk factor of AD among Taiwan Chinese.

Nitric oxide metabolites in induced sputum: a marker of airway inflammation in asthmatic subjects

BACKGROUND AND OBJECTIVE

The role of nitric oxide (NO) needs to be further clarified in allergic inflammation. This study was designed to investigate the relationships between NO metabolites and eosinophil count, eosinophil cationic protein (ECP), interleukin (IL)-5 in induced sputum from asthmatics.

METHODS

Hypertonic saline-induced sputum was obtained in 25 asthmatic subjects, among which 13 patients were examined before and after anti-asthmatic medications including steroid preparations. Ten normal subjects were enrolled as controls. Fresh expectorated sputum separated from saliva was treated with equal volume of dithiothreitol 0.1%, cytospinned for cell count, and the supernatant was collected for biochemical assay. NO metabolites were assayed by using modified Griess reaction. ECP was measured by fluoroimmunoassay, and detected IL-5 by a sandwich ELISA.

RESULTS

Asthmatic subjects, compared with controls, had significantly higher concentration of NO metabolites (1035.4 +/- 125.3 vs 557.2 +/- 101.5 micromol/L, P < 0.01), higher percentage of eosinophils (25.6 +/- 4.6 vs 1.7 +/- 0.2%, P < 0.01), and higher levels of ECP (1117.8 +/- 213.9 vs 154.6 +/- 47.4 microg/L, P < 0.01) in the induced sputum. IL-5 was detected more frequently in asthmatic subjects than in control subjects (11/25 [44%] vs 1/10 [10%], P < 0.05). According to asthma severity, moderate to severe asthmatic subjects (n = 18) had higher level of NO metabolites (1143.8 +/- 156.3 vs 575.5 +/- 89.5 micromol/L, P < 0. 01), higher levels of ECP and IL-5 (P < 0.01, respectively) in the induced sputum than in those of mild asthmatic subjects (n = 7). NO metabolites, the percentage of eosinophils, the levels of ECP, and IL-5 were reduced following treatment with anti-asthmatic drugs (P < 0.01, respectively). There were significant positive correlations between NO metabolites and percentage of eosinophils or ECP (r = 0. 34, P < 0.05; r = 0.28, P < 0.05). Negative correlations were noted between FEV1, FEV1/FVC and proportion of eosinophils, ECP, or IL-5 levels.

CONCLUSION

These findings confirmed that the level of NO metabolites was increased in the tracheobronchial secretion of asthmatic subjects and was paralleled with severity of asthma. Measurement of NO metabolites in induced sputum may be used for monitoring the degree of airway inflammation in asthmatics.

AgNOR of human interphase cells in relation to acrocentric chromosomes

Using simultaneous detection of fluorescence in situ hybridization (FISH) to acrocentric chromosome centromeres and argyrophilic nucleolar organizer regions (AgNOR), we investigated the number of AgNOR and involvement pattern of acrocentric chromosomes in the nucleoli in various types of human interphase cells. The number of AgNOR of normal gastric mucosal epithelial cells was 2.27 +/- 1.18 and was higher than that of lymphocytes (1.08 +/- 0.28) and lower than that of gastric cancer (7.76 +/- 3.21). The number of acrocentric chromosome centromere signals of normal gastric mucosal epithelial cells was higher than that of normal leukocytes (P < 0.000), and lower than that of gastric cancer (P < 0.000). The acrocentric chromosome centromere signals in the lymphocytes and neutrophils were only half of that expected for diploid cells, perhaps related to acrocentric chromosome association. The proportion of acrocentric chromosomes attached to AgNOR in gastric cancer (0.88 +/- 0.22) was significantly higher than that of normal gastric mucosal epithelial cells (0.72 +/- 0.35, P = 0.007). In conclusion, acrocentric chromosome association appears to be present in circulating leukocytes even in interphase. The number of AgNORs and proportion of acrocentric chromosomes involved in AgNORs in human interphase cells may vary according to cell types. This could play a significant role in rDNA transcription and determination of cell phenotype, including malignant change.

Total synthesis of (+/-)-homoepibatidine

Total synthesis of (+/-)-homoepibatidine (2), which contains the 8-azabicyclo[3.2.1] octane ring system, was achieved by using palladium-catalyzed Heck-type coupling reaction from 3.

Noonan syndrome associated with moyamoya disease: report of one case

We report a patient with Noonan syndrome who had repeated transient ischemic attacks. Moyamoya was diagnosed from the image study. In addition, flunarizine therapy seems to be effective in the prevention of recurrent symptoms and signs. The association of Noonan syndrome and Moyamoya has been reported. To the best of our knowledge, this is the second case report of an association of the Noonan syndrome and Moyamoya. Further study should ensue.

PG490 (triptolide) cooperates with tumor necrosis factor-alpha to induce apoptosis in tumor cells

Progress in the treatment of solid tumors has been slow and sporadic. The efficacy of conventional chemotherapy in solid tumors is limited because tumors frequently have mutations in the p53 gene. Also, chemotherapy only kills rapidly dividing cells. Members of the tumor necrosis factor (TNF) family, however, induce apoptosis regardless of the p53 phenotype. Unfortunately, the cytotoxicity of TNF-alpha is limited by its activation of NF-kappaB and activation of NF-kappaB is proinflammatory. We have identified a compound called PG490, that is composed of purified triptolide, which induces apoptosis in tumor cells and sensitizes tumor cells to TNF-alpha-induced apoptosis. PG490 potently inhibited TNF-alpha-induced activation of NF-kappaB. PG490 also blocked TNF-alpha-mediated induction of c-IAP2 (hiap-1) and c-IAP1 (hiap-2), members of the inhibitor of apoptosis (IAP) family. Interestingly, PG490 did not block DNA binding of NF-kappaB, but it blocked transactivation of NF-kappaB. Our identification of a compound that blocks TNF-alpha-induced activation of NF-kappaB may enhance the cytotoxicity of TNF-alpha on tumors in vivo and limit its proinflammatory effects.

The health status of Gulf War veterans: lessons learned from the Department of Veterans Affairs Health Registry

OBJECTIVE

To describe the demographic characteristics and postwar health status of U.S. Gulf War veterans who participated in the Department of Veterans Affairs health examination registry program.

DESIGN

Case records of 52,835 veterans who participated in a standardized health examination program were reviewed.

SETTING

Participants volunteered for physical examinations at a Department of Veterans Affairs medical treatment facility from August 1992 to September 1996.

SUBJECTS

U.S. Gulf War veterans deployed to southwest Asia between August 1990 and 1996.

MAIN OUTCOME MEASURE

Demographic, military, symptom, and International Classification of Diseases, Ninth Revision, Clinical Modification, diagnostic categories.

RESULTS

A wide variety of symptoms and diagnoses were reported without apparent internal variation by military characteristics (branch and service component). The frequency of symptoms (fatigue, skin rash, headache, muscle and joint pain, and memory loss) reported increased over time, whereas the proportion of individuals with physician-diagnosed illnesses remained fairly constant. No single category of disease increased or decreased substantially over time.

CONCLUSIONS

Veterans have experienced a wide variety of health problems since their Gulf War service. These problems, in aggregate, are different from what has been seen in other armed conflicts. The Department of Veterans Affairs registry is a very large case series and has failed to identify a single, unique syndrome or new illness after Gulf War service. An epidemiologic study would better define the prevalence of specific symptoms and medical conditions among Gulf War veterans and to what extent any of the conditions identified are associated with Gulf War military service. The knowledge provided by such studies would be important to development of preventive measures and future deployment medical surveillance planning.

Elevated neuronal Cdc2-like kinase activity in the Alzheimer disease brain

Neurofibrillary tangles (NFT) in Alzheimer's disease (AD) consist largely of hyperphosphorylated tau protein. Many of the phosphorylation sites on tau are serine/threonine-proline sequences, several of which are phosphorylated in vitro by neuronal Cdc2-like kinase (Nclk), a kinase composed of Cdk5 and its activator(s). Thus, tau hyperphosphorylation in AD may result in part from deregulation of Nclk. To test this hypothesis, we examined Nclk activity in prefrontal and cerebellar cortex from 15 postmortem AD and 16 age-matched control subjects, and corrected either for Cdk5 level or for neuronal loss. The ratio of Nclk activity in prefrontal versus cerebellar cortex was then compared. When corrections were made for neuronal loss, the ratios of kinase activity in prefrontal versus cerebellar cortex were significantly higher in AD (6.45+/-0.86) than the controls (3.13+/-0.46; P = 0.003). This finding is consistent with a role for Nclk in the pathogenesis of NFT in AD.

Vagus nerve modulates secretin binding sites in the rat forestomach

Secretin is well known for its inhibitory action on gastric motility. It has been reported that secretin in a physiological dose inhibits gastric motility through mediation by the vagal afferent pathway. Secretin also elicited relaxation of carbachol-stimulated rat forestomach muscle strips by binding to its receptors, suggesting a direct action on this peripheral tissue. We hypothesized that vagal input may affect the action of secretin by modulating the level of secretin receptor in the forestomach. Several treatments, including vagal ligation, vagotomy, perivagal application of capsaicin or colchicine, intravenous infusion of tetrodotoxin, and intraperitoneal injection of atropine, were performed to investigate their effects on secretin receptor binding to forestomach membranes. Specific binding of 125I-labeled secretin to forestomach membranes was significantly decreased (45%) by vagal ligation, vagotomy (50%), or perivagal colchicine treatment (40%). On the contrary, specific binding of 125I-secretin was not affected by perivagal capsaicin treatment, intravenous infusion of tetrodotoxin, or intraperitoneal injection of atropine. By Scatchard analysis of the binding data, the capacity of the high-affinity binding sites in forestomach membranes was found to decrease significantly after vagal ligation compared with membranes from the sham-operated group. However, the affinity at the high-affinity binding sites, the binding parameters of the low-affinity binding sites, and binding specificity were not changed. Vagal ligation but not perivagal capsaicin treatment reduced the inhibitory effect of secretin on bethanechol-stimulated contraction of isolated forestomach muscle strips, causing a right shift in the dose-response curve. These results suggest that vagal input through axonal transport plays a significant role on secretin action by modulating the capacity of secretin binding sites (but not affinity or specificity), at least in rat forestomach.

Binding and catalytic properties of the Cdc2 and Crp proteins of Dictyostelium

Dictyostelium expresses at least two proteins of the cyclin-dependent kinase (Cdk) family, Cdc2 and Crp. Cdc2 levels remain relatively constant during differentiation, whereas the levels of Crp increase dramatically as differentiation progresses. Crp is highly related to the mammalian Cdk5, and p25 (a truncated form of p35, the activating subunit of Cdk5 from mammalian brain) stimulates the histone H1 kinase activity of GST-Crp by several fold. In contrast, p25 does not stimulate the histone H1 kinase activity of GST-Cdc2 or the Cdc2 activity present in cell extracts from vegetative Dictyostelium cells. GST-Cdc2, in vitro translated Cdc2 and Cdc2 from all stages of differentiation bind to p13suc1. In contrast, GST-Crp, in vitro translated Crp and the Crp protein present in cell extracts do not bind to p13suc1. We have confirmed a previous report by Arakane and Maeda [J. Plant Res. (1997) 110, 81-85] that there is a peak of p13suc1 bound histone H1 kinase activity during late development, but we found that there was no corresponding peak of p13suc1 bound Cdc2 protein that corresponds to this activity. Taken together, these data suggest that neither Cdc2 nor Crp is responsible for the late developmental peak of histone H1 kinase activity that binds to p13suc1.

Intravenous immune globulin (i.v.IG) therapy in steroid-resistant atopic dermatitis

Many trials have been done on steroid-resistant atopic dermatitis. Recently, intravenous immune globulin (i.v.IG) was reported to be effective in the treatment of steroid-dependent atopic dermatitis. The aim of this study was to clarify whether i.v.IG therapy is effective in steroid-resistant atopic dermatitis. Forty-one steroid-resistant atopic dermatitis patients were tested in this study. Patients who weighed less than 30 kg were administered 500 mg/kg of i.v.IG. Patients who weighed 30 kg or more were administered 15 g of i.v.IG. Patient evaluations and laboratory tests with peripheral bloods such as eosinophil percentages and serum IgE levels were performed at days 0, 1, 7, and 21. In the present study, patients who responded to i.v.IG therapy were classified as Group A. Twelve patients who showed transient effects with lower clinical significance were classified as Group B (29.3%). Remaining 12 patients (29.3%) in Group C showed no improvement at all. Serum IgE levels and blood eosinophil percentages were markedly decreased in Group A. I.v.IG therapy may be recommended in the treatment of atopic dermatitis with extremely high serum IgE levels.

Serial brain SPECT images in a case of Sydenham chorea

BACKGROUND

The pathophysiological nature of Sydenham chorea (SC) has been presumed to be an autoimmune-mediated inflammatory process. Positron emission tomography in SC has revealed a striatal hypermetabolism that might explain the transient neuronal dysfunction. However, any focal hyperperfusion in the striatum or its related structures has not been demonstrated in previous single photon emission computed tomographic (SPECT) imaging studies, which raised a concern about the pathogenesis of the striatal hypermetabolism.

OBJECTIVE

To investigate the cerebral perfusion patterns of the subcortical structures by using serial technetium Tc 99m-ethyl cysteinate dimer SPECT in a case of SC, which may provide a clue for the pathophysiological mechanisms.

DESIGN

A case report and serial SPECT studies.

CASE PRESENTATION

A girl aged 4 years 3 months showed severe generalized choreic movements with concomitant signs of acute pharyngitis. Results of a laboratory study taken 7 days after the onset of chorea showed elevated antistreptolysin O titer, C-reactive protein levels, and erythrocyte sedimentation rate. Other laboratory data, throat culture, echocardiography, brain magnetic resonance imaging, and electroencephalography did not reveal any abnormalities. Five days after treatment with haloperidol and penicillin, the chorea began to improve slowly, and completely resolved in 2 months.

RESULTS

Three serial SPECT images and semiquantitative analysis of cerebral perfusion were obtained. Cerebral perfusion in the striatum and thalamus was markedly increased bilaterally during the stage of active chorea and then returned nearly to its baseline level during the convalescent phase. These cerebral perfusion patterns were concordant with semiquantitative analysis.

CONCLUSIONS

Hyperperfusion in both the striatum and thalamus in our patient may reflect the subcortical inflammatory processes in SC. The unequivocal SPECT findings in our patient are difficult to reconcile with the negative findings of previous SPECT studies but may suggest the heterogeneity of the perfusion patterns in SC.

Increased site-specific phosphorylation of tyrosine hydroxylase accompanies stimulation of enzymatic activity induced by cessation of dopamine neuronal activity

Activation of striatal dopamine (DA) neurons by neuroleptic treatment or by electrical stimulation of the nigrostriatal pathway increases the activity of tyrosine hydroxylase (TH). The increase is mediated by phosphorylation of the enzyme. However, abolition of DA neuronal activity [by gamma-butyrolactone (GBL) treatment or transection of the nigrostriatal pathway] also increases TH activity. Quantitative blot immunolabeling experiments using site- and phosphorylation state-specific antibodies to TH demonstrated that GBL treatment (750 mg/kg, 35 min) significantly increased phosphorylation at Ser19 (+40%) and Ser40 (+217%) without altering Ser31 phosphorylation. Concomitantly, GBL treatment [along with the 3,4-dihydroxyphenylalanine (dopa) decarboxylase inhibitor NSD-1015, 100 mg/kg, 30 min] increased in vivo striatal dopa accumulation and in vitro TH activity 3-fold. Likewise, cerebral hemitransection of the nigrostriatal pathway significantly increased phosphorylation of TH at Ser19 (+89%) and Ser40 (+158%) but not at Ser31; dopa levels were increased accordingly (+191%). Kinetic analysis of TH activity established that GBL treatment and hemitransection primarily decreased the Km for the cofactor tetrahydrobiopterin (3-fold). The effects of GBL and hemitransection were abolished or attenuated by pretreatment with the DA agonist R-(-)-N-n-propylnorapomorphine (NPA; 30 microgram/kg, 40 min), presumably via stimulation of inhibitory presynaptic DA autoreceptors. NPA dose-response curves for reversal of GBL-induced dopa accumulation and Ser40 phosphorylation were identical; however, only the highest dose of NPA reversed the small and variable increase in Ser19 phosphorylation. Thus, TH activity seems to be regulated by phosphorylation in both hyper- and hypoactive striatal DA neurons; in the latter case, activation seems to be caused by selective phosphorylation of Ser40.

The effects of transferring tumor suppressor gene p16INK4A to p16INK4A-deleted cancer cells

OBJECTIVES

p16 is known to be an important tumor suppressor gene and is also called MTS1 (multiple tumor suppressive gene 1). Especially in the case of non-small cell lung cancer, it was not expressed in more than 70% of cell lines examined. To determine changes in cell-cycle related proteins and the tumorigenic effect, we, therefore, transfected p16INK4A gene into lung cancer cell lines.

METHODS

We transfected p16INK4A gene into lung cancer cell lines which do not express p16 protein. We evaluated the effect by clonogenic assay and observed the changes of cell-cycle related proteins.

RESULTS

The newly-expressed p16 formed a complex with cdk4, and phosphorylated pRB was decreased, although cyclin D1 and pRB:cyclin D1 complex were unchanged. Clonogenic assay after selection with G418 showed that, in the cell lines transfected with p16, tumorigenicity was significantly less than in the control.

CONCLUSION

These results suggest that the p16INK4A gene can be a candidate for gene therapy in cases of NSCLC in which p16INK4A gene is inactivated.

The effects of oxygen radicals on the activity of nitric oxide synthase and guanylate cyclase

Reactive oxygen species such as superoxides, hydrogen peroxide (H2O2) and hydroxyl radicals have been suggested to be involved in the catalytic action of nitric oxide synthase (NOS) to produce NO from L-arginine. An examination was conducted on the effects of oxygen radical scavengers and oxygen radical-generating systems on the activity of neuronal NOS and guanylate cyclase (GC) in rat brains and NOS from the activated murine macrophage cell line J774. Catalase and superoxide dismutase (SOD) showed no significant effects on NOS or GC activity. Nitroblue tetrazolium (NBT, known as a superoxide radical scavenger) and peroxidase (POD) inhibited NOS, but their inhibitory actions were removed by increasing the concentration of arginine or NADPH respectively, in the reaction mixture. NOS and NO-dependent GC were inactivated by ascorbate/FeSO4 (a metal-catalyzed oxidation system), 2'2'-azobis-amidinopropane (a peroxy radical producer), and xanthine/xanthine oxidase (a superoxide generating system). The effects of oxygen radicals or antioxidants on the two isoforms of NOS were almost similar. However, H2O2 activated GC in a dose-dependent manner from 100 microM to 1 mM without significant effects on NOS. H2O2-induced GC activation was blocked by catalase. These results suggested that oxygen radicals inhibited NOS and GC, but H2O2 could activate GC directly.

Cloning and expression of cDNA for a human Sia alpha 2,3Gal beta 1, 4GlcNA:alpha 2,8-sialyltransferase (hST8Sia III)

The cDNA encoding human Sia-alpha2,3-Gal-beta1,4-GlcNAc-R:alpha2, 8-sialyltransferase, hST8Sia III, was isolated by screening of a human brain cDNA library with polymerase chain reaction-amplified DNA probe generated from the sequence of mouse ST8Sia III (mST8Sia III) and by 5' rapid amplification of cDNA ends of mRNA isolated from human brain tissues. Comparative analysis of the predicted protein-coding region between our cloned hST8Sia III and mST8Sia III showed 92 and 96% identities in the nucleotide and the amino acid sequence, respectively. The soluble hST8Sia III protein expressed in COS-7 showed an extremely high catalytic activity of transferring sialic acid through alpha2,8-linkage to intact fetuin glycoprotein, whereas the transferring activity was completely undetectable toward either alpha2,6-sialylated glycoprotein or desialylated glycoprotein acceptors. Northern analysis of hST8Sia III showed that the transcript corresponding to 11 kb was expressed in both human fetal and adult brain, while the expression of the 5.5-kb transcript was restricted to fetal liver, indicating that the expression of hST8Sia III is developmentally and tissue-specifically regulated.

Blood eosinophils and serum IgE as predictors for prognosis of interferon-gamma therapy in atopic dermatitis

BACKGROUND

Interferon-gamma (IFN-gamma) therapy has been reported to be effective in atopic dermatitis. However, IFN-gamma therapy in atopic dermatitis has not yet been well established. In this study, immunologic variables were evaluated as predictors for the prognosis of IFN-gamma therapy in atopic dermatitis.

METHODS

Sixty-eight atopic dermatitis patients were each treated 18 times with 2 x 10(6) units/m2 IFN-gamma. Blood IgE level, eosinophil percentage, eosinophil count, and levels of IFN-gamma, interleukin-4 (IL-4), IL-5, and IL-10 were investigated. According to clinical responses, patients were classified into three groups: patients with improved clinical severity scores of over 20% were included in group A; those with improved scores of 20% or less in group B; and those with no improvement in group C.

RESULTS

Serum IgE levels and blood eosinophil percentages were the lowest in group A. Most atopic dermatitis patients with an eosinophil percentage over 9% and IgE level over 1500 IU/ml did not respond to IFN-gamma therapy. Initial IL-10 levels were the highest in group A. IL-4 levels in group A, and IL-5 and IL-10 levels in all groups were significantly decreased by IFN-gamma therapy.

CONCLUSIONS

IFN-gamma therapy may be recommended for atopic dermatitis patients with blood eosinophil percentages less than 9% and serum IgE levels less than 1500 IU/ml.

Fractional allelic loss in gastric carcinoma correlates with growth patterns

To gain an insight into the genetic events underlying morphological phenotypes, we analysed 58 gastric carcinoma tissues for the genome-wide allelotype study using microsatellite markers. Based on a binomial distribution, loss of heterozygosity (LOH) that was significantly more frequent than expected (P<0.05) thus interpreted as nonrandom LOH selected during tumorigenesis. The overall extent of chromosomes undergoing LOH i.e. fractional allelic loss (FAL, the ratio of LOH-positive markers to the total number of informative markers) was measured in each tumor patient. Nonrandom LOH was found on 17p (48.0%), 18q (38.4%), 13q (38.1%) and 9p (36.4%). Overall, there were no significant phenotypes correlated with allelic loss on specific chromosome regions. Based on a bimodal distribution of FAL values with two peaks bordered by a mean of 0.233, tumors were classified into LOH-related (>0.233) and LOH-unrelated (<0.233) types. Among 24 patients with LOH-related tumors, increase in the infiltrative type of growth pattern was found to correspond with a significant trend of increasing FAL values. This study shows that the growth pattern of gastric carcinoma is correlated with FAL, suggesting that a malignant phenotype is influenced by LOH event.

Regulation of exit from quiescence by p27 and cyclin D1-CDK4

The synthesis of cyclin D1 and its assembly with cyclin-dependent kinase 4 (CDK4) to form an active complex is a rate-limiting step in progression through the G1 phase of the cell cycle. Using an activated allele of mitogen-activated protein kinase kinase 1 (MEK1), we show that this kinase plays a significant role in positively regulating the expression of cyclin D1. This was found both in quiescent serum-starved cells and in cells expressing dominant-negative Ras. Despite the observation that cyclin D1 is a target of MEK1, in cycling cells, activated MEK1, but not cyclin D1, is capable of overcoming a G1 arrest induced by Ras inactivation. Either wild-type or catalytically inactive CDK4 cooperates with cyclin D1 in reversing the G1 arrest induced by inhibition of Ras activity. In quiescent NIH 3T3 cells expressing either ectopic cyclin D1 or activated MEK1, cyclin D1 is able to efficiently associate with CDK4; however, the complex is inactive. A significant percentage of the cyclin D1-CDK4 complexes are associated with p27 in serum-starved activated MEK1 or cyclin D1 cell lines. Reduction of p27 levels by expression of antisense p27 allows for S-phase entry from quiescence in NIH 3T3 cells expressing ectopic cyclin D1, but not in parental cells.

Continuous wavelet analysis as an aid in the representation and interpretation of electrogastrographic signals

This paper presents an application of the continuous wavelet transform (CWT) in the analysis of electrogastrographic (EGG) signals. Due to the nonstationary nature of EGG signals, the CWT method, which uses multiresolution scaled windows, gives a better time-frequency resolution than the short-time Fourier transform, which uses a fixed window. Spike activity due to gastric contraction was investigated through experiments on dogs. During spike activity we observed an increase in magnitude of the slow wave and the appearance of a low frequency component with half the frequency of the slow wave. Studies of the EGG signals from the small intestine are also presented to investigate the hypothesis that its slow wave might be confounded with spike activity in the stomach due to the similarity of their frequency ranges.

Inhibition of midgut ion transport by allatotropin (Mas-AT) and Manduca FLRFamides in the tobacco hornworm Manduca sexta

Short-circuit current (Isc) across the posterior midgut of day 2 fifth-instar tobacco hornworms (Manduca sexta) is inhibited by Manduca allatotropin (Mas-AT) and two Manduca FLRFamides (F7G and F7D). Another FLRFamide, F10, and the related molluscan tetrapeptide FMRFamide elicited only a modest inhibition of Isc. Mas-AT, F7G and F7D inhibited the Isc in a dose-dependent manner. Maximal inhibition of Isc by Mas-AT was achieved at a concentration of 50 nmol l-1. At 100 nmol l-1, Mas-AT produced a significantly greater inhibition of Isc than did F7G and F7D. The inhibition caused by Mas-AT was reversed by removing the peptide. Furthermore, the action of Mas-AT could be blocked by preabsorption with its antiserum. When F7G or F7D was added after the Isc had been inhibited by Mas-AT, a further reduction in the Isc was observed. No additive effects were seen when F7G and F7D were added together. In comparison with the anterior and middle regions, the posterior section of the midgut was the most sensitive to these three peptides. The Isc of midguts dissected from feeding fourth instars was inhibited by Mas-AT, F7D and F7G, whereas the Isc of midguts dissected from pharate fifth instars or wandering fifth instars was virtually unaffected by these peptides. Active ion transport across the posterior midgut of the silk moths Hyalophora cecropia and Bombyx mori was unaffected by these peptides.

Circulating soluble CD5 in atopic dermatitis

The CD5/Leu-1 is involved in the activation of the T-cell helper function through T/B-cell collaboration by CD5/CD72 interaction. T-cell function is known to be dysregulated in atopic dermatitis. However, to date, the role of CD5 has not been investigated in atopic dermatitis, nor has the presence of circulating soluble CD5 been reported in atopic dermatitis. Five patients with atopic dermatitis who showed typical symptoms, 5 acute febrile patients and 5 normal subjects were tested. Peripheral blood mononuclear cells and plasma were separated. The T- and B-cells were separated using immunomagnetic beads. Reverse transcription polymerase chain reaction was performed using CD5 specific primers. Immunoblotting with the mouse antiCD5 monoclonal antibody was done. Circulating soluble CD5 was present only in 4 out of 5 atopic patients. However, it was not detected in acute febrile patients nor in normal subjects. CD5 mRNA expression was detected in all atopic patients and acute febrile patients. CD5 mRNA expression in T- and B-cells was tested in patients with atopic dermatitis and was detected only in the T-cells. In this study, circulating soluble CD5 was detected in atopic patients and soluble CD5 was suspected to participate in the pathogenesis of atopic dermatitis. CD5 mRNA expression was detected only in T-cells, which suggests that circulating soluble CD5 might be produced from T-cells.