Isolation of a full-length cDNA clone for human GTP cyclohydrolase I type 1 from pheochromocytoma

Although the existence of three different cDNA forms of human GTP cyclohydrolase I (GCH I) have been reported (Togari et al., 1992), the full-length sequence of any human GCH I cDNA involving poly (A) tail has not yet been documented. In the present study, we first isolated a full-length cDNA clone encoding human GCH I type 1 from human pheochromocytoma cDNA library. The length of the cDNA insert was 2,921 base pairs including poly (A) tail. RNA blot analysis showed a single mRNA species of 4.0 kb in human pheochromocytoma tissue.

Effect of epidermal growth factor on cadherin-mediated adhesion in a human oesophageal cancer cell line

Epidermal growth factor (EGF) mediates many pleiotrophic biological effects, one of which is alteration of cellular morphology. In the present study, we examine the possibility that this alteration in cell morphology is caused in part by the dysfunction of cadherin-mediated cell-cell adhesion using the human oesophageal cancer cell line TE-2R, which expresses E-cadherin and EGF receptor. In the presence of EGF, TE-2R changed its shape from round to fibroblastic and its colony formation from compact to sparse. Vanadate, a tyrosine phosphatase inhibitor, further potentiated the EGF response, whereas herbimycin A, a tyrosine kinase inhibitor, interfered with it. Moreover, EGF enabled the cells to invade in organotypic raft culture. These phenomena were accompanied not by decreased expression of the E-cadherin molecule but by a change in its localisation from the lateral adhesion site to the whole cell surface. Both alpha- and beta-catenin, cadherin-binding proteins, were also expressed at the same level throughout these morphological changes. Finally, we examined tyrosine phosphorylation of E-cadherin and alpha- and beta-catenin, and observed tyrosine phosphorylation of beta-catenin induced by EGF. These results suggest that EGF counteracts E-cadherin-mediated junctional assembly through phosphorylation of beta-catenin and modulates tumour cell behaviour to a more aggressive phenotype.

Detachment of desmosomes in a microcystic meningioma

This report demonstrates the detachment of desmosomes in the microcystic area of a frontal convexity meningioma removed from a 69-year-old woman. Well-developed interdigitations of the tumor cell processes with numerous desmosomes and with narrow extracellular spaces were characteristic features of the solid area of the meningioma. By contrast, the microcystic area of the tumor had markedly distended extracellular spaces. Various stages in the separation of desmosomal attachments were seen in this area. The observed configurations ranged from the widening of opposing junctions to the formation of large cavities where hemidesmosome-like structures were evident. The latter lacked basal lamina, and are considered to represent a transition leading to the loss of desmosome, and thus involved in the enlargement of the extracellular space in microcystic meningiomas.

Dilated cardiomyopathy defines serum autoantibodies against G-protein-coupled cardiovascular receptors

In order further to identify the prevalence of anti-receptor autoantibodies in the sera of patients with dilated cardiomyopathy (DCM), we attempted to detect autoantibodies against a series of G-protein-coupled cardiovascular receptors in a well-defined population of DCM patients from Japan. Peptides corresponding to the sequences of the second extracellular loops of the human beta 1 and beta 2 adrenoceptors, alpha 1 adrenoceptors, M2 muscarinic acetylcholine receptors and angiotensin II-1 (AT1) receptors were used as antigens in an enzyme immunoassay to screen the sera from patients with DCM (n = 28). Nine sera from patients with DCM (32%) and 2 sera from healthy subjects (9%) recognized the beta 1 adrenoceptor peptide. Ten sera from patients (36%) and 3 sera from healthy subjects (13%) recognized the M2 receptor peptide. Thirty-six per cent of the patients with autoantibody against the beta 1 adrenoceptor peptide. Ten sera from patients (36%) and 3 sera from healthy subjects (13%) recognized the M2 receptor peptide. Thirty-six per cent of the patients with autoantibody against the beta 1 adrenoceptor had autoantibody against the M2 receptor. However, no significantly high frequencies of autoantibodies against the beta 2 adrenoceptor, alpha 1 adrenoceptor and AT1 receptor were found in DCM patients. Our results demonstrate that a subgroup of patients with DCM have a specific spectrum of autoantibodies which are specifically directed against the second extracellular loops of the beta 1 adrenoceptors and M2 muscarinic receptors rather than other cardiovascular receptors.

Detection of the products of polymerase chain reaction by an ELISA system based on an ion sensitive field effect transistor

An ELISA system was developed using a pH sensitive ISFET (pH-FET) as a detector, a pipette tip as a solid phase, and urease as a detecting enzyme. Double stranded PCR products with digoxigenin and biotin at both terminals were obtained by using digoxigenin- and biotin-labeled primers. 1 microliters of the PCR solution was directly introduced into the end part of a pipette tip coated with anti-digoxigenin antibody. Biotin-labeled PCR products captured at the solid phase were detected with avidin-urease, of which the activity was measured by a pH-FET in a pH-measuring cell containing urea solution. The assay was used to detect HTLV-I provirus gene integrated in the genome of a human MT-1 cell, and it was found that 100 pg of the genomic DNA of MT-1 cell was specifically detectable after 35 cycles of PCR. Also the detection limit of the present ELISA system itself was determined by using known amounts of purified PCR product labeled with digoxigenin and biotin, and it was found that 10 amol of the labeled DNA in 1 microliter of sample was detectable.

[A case of severe pneumonia in an elderly man, caused by Citrobacter freundii suspected to have a low susceptibility to imipenem/cilastatin sodium]

An 80-year-old blind man with lepromatous leprosy suffered from right femoral neck and humeral neck fractures on July 9, 1993. Because of fever (38.6 degrees C), difficult expectoration and diffuse bilateral perihilar infiltrates with consolidation in the left lower lung field on his chest radiograph, severe pneumonia was diagnosed. With intravenous hyperalimentation, imipenem/cilastatin (IPM/CS), ceftazidime, minocycline, gentamicin (GM), and human immunoglobulin were administrated. On July 29, hip screw-plate fixation was done. Citrobacter freundii was isolated from the sputum and its susceptibility was IPM/CS+, GM3+. Multi-drug therapy with GM and other antibiotics improved the patients' condition, but Citrobacter freundii were still detected and 43 days of medication were needed. According to a report by the Ministry of Health and Welfare in 1992, the resistance rate of IPM/CS against Citrobacter freundii is only 0.7%, and IPM/CS is more effective than beta-Lactams. This is a very rare case of severe pneumonia in an elderly patient caused by Citrobacter freundii that was suspected to have low susceptibility to IPM/CS.

Immunolocalization of a fibronectin-binding proteoglycan (PG-P1) immunologically related to HSPG2/perlecan in normal and fibrotic human liver

Immunolocalization of a fibronectin-binding proteoglycan (PG-P1) in relation to fibronectin, type IV collagen and laminin, in normal and fibrotic human liver was investigated by light and electron microscopy. HS-42, which is a monoclonal antibody to PG-P1 and is reported to recognize a heparan sulfate proteoglycan named HSPG2/perlecan, was used for this purpose. Light microscopy in the human liver with minimal changes revealed that PG-P1 was present along the hepatic sinusoids as well as fibronectin and type IV collagen, whereas laminin was only weakly detected. In portal areas, PG-P1 was only localized on basement membranes around bile duct systems and blood vessels, as well as laminin and type IV collagen, while fibronectin was scarcely detected in basement membranes. In the fibrotic liver, fibronectin was abundant in necrotic and/or newly fibrosing areas, while PG-P1 was absent in these regions. Using immunoelectron microscopy, PG-P1 was localized in the space of Disse in nearly normal livers and was only detected on basement membranes in portal tracts. In fibrotic livers, PG-P1 in the space of Disse occasionally showed a basement-membrane-like deposition in parallel with the increased light microscopical deposition of laminin in this area, suggesting the positive participation of PG-P1 in the sinusoidal capillarization. Most capillary and sinusoidal endothelial cells, and rarely bile epithelial cells revealed the reaction products of PG-P1 in their rough endoplasmic reticulum and small vesicles. Thus, it was suggested that these cell types are mainly, if not wholly, responsible for PG-P1 production.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunosuppression by lymphokine-activated murine killer cell line with B-lymphoblast-lytic activity in vitro

The in vitro immunosuppressive effect caused by a murine lymphokine-activated killer cell line with B-lymphoblast-lytic activity was studied. The cloned cells (named BC-1.10, phenotype Thy 1.2+, LFA-1+, TCR-alpha beta-, TCR-gamma delta-, Fc gamma RII-, CD2-, CD3 epsilon-, CD4-, CD8- and express mRNA of zeta chain) suppressed LPS-induced Ig synthesis by B lymphoblasts previously stimulated with LPS. Phase-contrast microscopy indicated disappearance of B lymphoblasts at 24 h after the addition of BC-1.10 cells. This suppressive effect was reduced when BC-1.10 cells were pretreated with anti-LFA-1 mAb, which inhibits cytotoxicity of this clone. These data suggest that the immunosuppressive effect of BC-1.10 is due to an elimination of B lymphoblasts, and that one of the physiological functions of lymphokine-activated killer (LAK) cells, which are induced as a consequence of immune reactions, might be immunosuppression.

Periodic lateralized epileptiform discharges in EEG during recovery from hyponatremia: a case report

PLEDs were observed in a case of undifferentiated schizophrenia, transiently during the course of recovery from hyponatremia, and diffuse EEG slowing remained even after the serum sodium had returned to normal range. It was considered that PLEDs had occurred transiently in relation to hemispheric ischemic disturbance induced by hyponatremia. The characteristics of PLEDs associated with hyponatremia will need to be studied further in more patients with hyponatremia.

Transient expression of [D-Ala2] deltorphin I-like immunoreactivity in prenatal rat small intestine

We studied the distribution of immunoreactive elements for [D-Ala2] deltorphin I (DADTI), a delta-opioid receptor ligand, in fetal and postnatal rat small intestine. DADTI-like immunoreactive cells were detected transiently on embryonic Days 20 and 21. Electron microscopic examination revealed that positive staining occurred in mucous epithelial cells, either mature goblet cells or undifferentiated cells containing only a few mucous granules. Positive immunoreaction products in mature goblet cells were confined in their apical cytoplasm to the luminal parts of mucous granule aggregates. The result suggests that a DADTI-like molecule(s) is synthesized in rat intestinal goblet cells and is secreted in a diacrine fashion into the intestinal lumen at a late fetal period. The molecule(s) thus secreted may be important for the intestine of rats just before birth, because DADTI-like immunopositive goblet cells are no longer seen at any postnatal period.

[Clinical bacteriology and empiric therapy for hospital-acquired pneumonia in the elderly at a national leprosarium]

Hospital-acquired pneumonia is one of the most important fatal respiratory diseases in the elderly. Prompt and precise empiric therapy is essential for recovery. Fourteen isolates from twelve elderly lepromatous leprosy patients (9 men, 3 women, mean age of 75.8 years) with hospital-acquired pneumonia were studied. Subsequently, empiric therapy with gentamicin and beta-lactams for nosocomial pneumonia in the elderly was examined. Fourteen types of bacteria isolated from expectorated sputum specimens consisted mainly of ten strains of gram-negative bacilli (71%) six of Klebsiella pneumoniae, one each of Citrobacter freundii, Enterobacter agglomerans, Serratia liquefaciens, and Aeromonas hydrophilia and four strains of gram-positive cocci (29%) two of Staphylococcus sp., one each of Streptococcus sp. and Streptococcus pneumoniae. Methicillin-resistant Staphylococcus aureus and Pseudomonas sp. were not detected. Resistance rates of the etiologic agents to the antibiotics showed that gentamicin was 7.7%, ceftazidime 0%, and cefmetazole 23.1%. Cephalosporins were superior to penicillins. As a result of empiric therapy, six elderly leprosy patients with nosocomial pneumonia were cured and one improved temporarily. This study shows the necessity of specific empiric therapy for hospital-acquired pneumonia in a hospital with many elderly patients. The combination of gentamicin and beta-lactams is of value as an initial antibiotic therapy for hospital-acquired pneumonia in the elderly.

Treatment of virus-induced myocardial injury with a novel immunomodulating agent, vesnarinone. Suppression of natural killer cell activity and tumor necrosis factor-alpha production

Controversy still exists concerning the therapy for viral myocarditis which manifests a wide variety of clinical symptoms. Vesnarinone, a quinolinone derivative that was developed as a positive inotropic agent with complex actions, including phosphodiesterase inhibition and cation channel modification, has recently been confirmed to improve the prognosis of patients with chronic heart failure. However, the precise mechanism of this beneficial effect is not yet clearly understood. In this study, using a murine model of acute viral myocarditis resulting from encephalomyocarditis virus infection, survival and myocardial damage were markedly improved by treatment with vesnarinone. In contrast, survival was not improved by treatment with amrinone, a phosphodiesterase inhibitor. Although vesnarinone did not inhibit viral replication or protect myocytes from viral direct cell injury, it did inhibit the increase in natural killer cell activity after viral infection. On the other hand, amrinone failed to inhibit natural killer cell activity. Both vesnarinone and amrinone suppressed the production of tumor necrosis factor-alpha. Therefore, we postulate that vesnarinone exerted its beneficial effects through an inhibition of natural killer cell activity, and that it serves as an immunomodulator providing new therapeutic possibilities for the treatment of viral myocarditis and/or immunological disorders.

Localization of [D-Ala2]deltorphin I-like immunoreactivity in perinatal rat respiratory system

The localization of [D-Ala2]deltorphin I, a delta-opioid receptor ligand, was studied in the lower respiratory tract of developing rats using an immunohistochemical method. [D-Ala2]-like immunoreactive cells were detected first in the principal bronchus as early as embryonic day 16. As embryos grew, positive cells became gradually visible everywhere from principal bronchi to respiratory bronchioles. The density of positive cells reached the highest level on embryonic day 21, but decreased gradually after birth. Positive cells were no longer seen on postnatal day 30 in any region of the airways. No positive cells were ever found in the trachea or alveoli of rats at any age studied. Ultrastructural examination indicated that the immunoreactive cells possessed a similar morphology to serous or Clara cells of the respiratory epithelium. Immunoreaction products tended to locate at the apical cytoplasm of positive cells. The results suggests that [D-Ala2]-like molecule(s) may be expressed transiently in serous cells or Clara cells, or both, of the rat bronchopulmonary tract. Such a molecule may act as a pulmonary growth-promoting or a differentiation-initiating factor in an early period of lung development.

Autoantibodies against cardiac G-protein-coupled receptors define different populations with cardiomyopathies but not with hypertension

It was previously shown that the second extracellular loop of cardiovascular G-protein-coupled receptors is an antigenic target for pharmacologically active autoantibodies in patients with idiopathic dilated cardiomyopathy. To extend these observations to cover patients with the same disease from different geographical origins or to patients with other cardiac diseases, peptides corresponding to the sequences of the second extracellular loops of the human M2 muscarinic receptors and beta adrenoceptors were used as antigens in an enzyme immunoassay. Sera from patients from Sweden and Japan with idiopathic dilated cardiomyopathy (DCM, n = 32), hypertrophic cardiomyopathy (HCM, n = 23), malignant essential hypertension (MEH, n = 11), malignant secondary hypertension (MSH, n = 10), and sera from healthy blood donors (HBD, n = 49) were tested. Sera from patients with DCM recognized the muscarinic receptor peptide in 38% of cases and the beta 1 adrenoceptor peptide in 31% of cases. In 50% of the positive patients, autoantibodies against both peptides coexisted as shown by competition experiments using both peptides as inhibitors. In HCM patients, there was a lower frequency of autoantibodies but with a higher but not significant predominance against the M2 peptide. No autoantibodies were detected in sera from patients with MEH or MSH. Autoantibodies against the M2 muscarinic receptors, affinity-purified from positive patients, displayed pharmacological activity as demonstrated by changes in the affinity and number of radioligand binding sites. In contrast, antibodies purified from positive HBD had no effect. These results confirm that autoantibodies displaying pharmacological activity against G-protein-coupled cardiovascular receptors are mainly restricted to patients with idiopathic dilated cardiomyopathy and that different autoantibody populations are responsible for the recognition of the different receptors.

Urinary carnitine excretion in patients with heart failure

To evaluate the fatty acid metabolism in heart failure, the semiquantitative analysis of urinary free carnitine and acylcarnitine was made by fast atom bombardment mass spectrometry (FABMS) in 22 patients (mean age 67.3 years) with heart failure and 19 age-matched healthy controls (average age 60.4 years). Urinary excretion of free carnitine was 0.20 +/- 0.118 ratio/mg creatinine in the healthy controls and 1.32 +/- 1.170 ratio/mg creatinine in the patients with heart failure. The latter value was significantly higher (p < 0.01). Patients with heart failure were classified into two groups according to the urinary free carnitine concentration. One was the high excretion group (2.19 +/- 0.102 ratio/mg creatinine, 12 cases) and the other was the low excretion group (0.37 +/- 0.212 ratio/mg creatinine, 10 cases). In the high excretion group, urinary acetylcarnitine was also increased, but no significant abnormalities were observed in the urinary organic acid profile. In the high group, 1 patient was classified as NYHA class III and 11 as NYHA class IV. Four patients died in the hospital. In the low excretion group, five patients were classified as NYHA class III and five as NYHA class IV. Only one patient died in the hospital. In the high group, patients with severe and prolonged heart failure tended to maintain higher values of urinary free carnitine. We could not find any abnormalities in fatty acid metabolism in patients with heart failure, but it is suspected that the patients who excrete large amounts of free carnitine into the urine, namely the patients with severe heart failure, have some possibility of carnitine deficiency.

[A case of drug induced pneumonitis caused by saiboku-To]

We report a case of drug induced pneumonitis caused by Saiboku-To. A 60-year-old woman was admitted to our hospital because of dry cough, fever and severe dyspnea after taking Saiboku-To. Blood gas analysis showed marked hypoxemia. Chest X-ray obtained on admission showed diffuse ground glass shadows in bilateral lung fields, and computed tomography showed diffuse interstitial shadows. Following steroid pulse therapy, clinical symptoms, hypoxemia and chest X-ray findings were ameliorated. Against medical advice, she took another Chinese medicine with ingredients similar to those of Saiboku-To. She complained of dry cough, fever and dyspnea and the chest X-ray again revealed diffuse ground glass shadows in both lung fields. Lymphocyte stimulation test against Saiboku-To and the patch test for Saiboku-To were positive. Therefore, we diagnosed this case as having pneumonitis due to Saiboku-To. This is first report of interstitial pneumonitis due to Saiboku-To.

Immunohistochemical evaluation of alpha-catenin expression in human gastric cancer

E-cadherin (E-cad) plays a major role in the maintenance of cell-cell adhesion in epithelial tissues, and impaired E-cad expression correlates with tumour invasion and metastasis. Alpha-catenin (alpha-cat), an undercoat protein of adherens junctions, binds to the cytoplasmic domain of E-cad and is essential for linking E-cad to actin-based cytoskeleton. We investigated E-cad and alpha-cat expression in 60 human gastric cancers immunohistochemically. The 60 gastric cancers were classified into 18 (30%) in which alpha-cat expression was preserved, and 42 (70%) reduced cases. The reduction of alpha-cat expression was significantly related to dedifferentiation, depth of invasion, infiltrative growth and lymph node metastasis. We also examined the co-expression of alpha-cat and E-cad. Seventeen (28%) tumours preserved both molecules [alpha-cat(+)/E-cad(+)] and 33 (55%) tumours reduced both [alpha-cat(-)/E-cad(-)], whereas 9 (15%) tumours exhibited alpha-cat(-)/E-cad(+). The frequency of lymph node metastasis in alpha-cat(-)/E-cad(+) tumour (67%) was significantly higher than that in alpha-cat(+)/E-cad(+) tumours (24%) and was close to that in alpha-cat(-)/E-cad(-) tumours (82%). The frequency of haematogenous liver metastasis in alpha-cat(-)/E-cad(+) tumours (44%) was significantly higher than that in alpha-cat(+)/E-cad(+) tumours (6%) or alpha-cat(-)/E-cad(-) tumours (9%). Thus, in all E-cad(+) tumours, the frequency of lymph node and liver metastasis was higher in alpha-cat(-) tumours than in alpha-cat(+) tumours. alpha-Cat expression is apparently better at predicting tumour invasion and metastasis than E-cad expression.

Immunohistochemical detection of alpha-catenin expression in human cancers

The function of E-cadherin is thought to be regulated by its associated cytoplasmic proteins including alpha-catenin. To determine whether possible downregulation of alpha-catenin expression may play a role in tumor invasion and metastasis through the dysfunction of E-cadherin, we investigated the expression of alpha-catenin in human carcinoma samples (esophagus, stomach, and colon) by immunohistochemistry using our monoclonal antibody against alpha-catenin (alpha-18). Normal epithelium expressed alpha-catenin strongly without exception. However, alpha-catenin expression was frequently reduced in primary tumors of esophagus (12 of 15:80%), stomach (14 of 20: 70%), and colon (8 of 10: 80%). Of the tumors with reduced alpha-catenin expression, alpha-catenin expression was completely negative in 70.6% of them (9 of 12 in esophagus, 9 of 14 in stomach, and 6 of 8 in colon). These results also suggested that some human cancer cells may have impaired E-cadherin-mediated cell adhesiveness through the downregulation of alpha-catenin expression.

Vesnarinone, a new inotropic agent, inhibits cytokine production by stimulated human blood from patients with heart failure

BACKGROUND

Vesnarinone, a quinolinone derivative, is a recently synthesized positive inotropic agent that has been shown to dramatically improve the survival of patients with heart failure. However, the mechanism of action of vesnarinone remains unknown. Reversible neutropenia complicated with vesnarinone therapy suggests that vesnarinone may modulate the production of cytokines. Because tumor necrosis factor (TNF)-alpha and other cytokines have been shown to depress myocardial contractility, we investigated the effects of vesnarinone on the production of various cytokines.

METHODS AND RESULTS

We studied the effects of vesnarinone on cytokine production by lipopolysaccharide (LPS)-stimulated whole blood from seven patients with heart failure and from five healthy volunteers. Heparinized blood was diluted in RPMI and stimulated with LPS. Vesnarinone was added in a range of 1 to 30 micrograms/mL, the blood was incubated for 24 hours, and interleukin (IL)-1 alpha, IL-1 beta, IL-6, TNF-alpha, interferon (IFN)-gamma, and granulocyte colony-stimulating factor (G-CSF) were measured by an enzyme-linked immunosorbent assay. LPS stimulation induced a more prominent increase in TNF-alpha in patients with heart failure than in healthy volunteers. Vesnarinone inhibited the production of TNF-alpha and IFN-gamma both in healthy volunteers and in patients with heart failure. IL-1 alpha and IL-1 beta were also suppressed in healthy volunteers, but this response was variable, and a significant reduction was not seen in patients with heart failure. Marked inhibition of G-CSF and other cytokines by vesnarinone was observed in one patient who had developed neutropenia as a result of vesnarinone therapy.

CONCLUSIONS

Although the number of study patients was small and the results are preliminary, these findings provide evidence that vesnarinone plays an important role in the regulation of cytokines and suggest that the reduction of cytokine release may contribute to the beneficial effects of the drug in the treatment of heart failure. Furthermore, the measurement of cytokines may be useful in predicting the occurrence of neutropenia, which has been occasionally reported in patients treated with vesnarinone.

Vesnarinone prolongs survival and reduces lethality in a murine model of lethal endotoxemia

Vesnarinone (3,4-Dihydro-6-[4(3,4-dimethoxybenzoyl)-1-piperanizyl]-2(1H)-quino linone), a recently synthesized quinolinone derivative with positive inotropic properties, has been reported the survival of patients with chronic congestive heart failure. However, the mechanisms that contribute to this improvement are not yet well understood. There is increasing evidence that vesnarinone has novel immunosuppressive properties related to its inhibition of cytokine production. Cytokines have been shown to play a pivotal role in the pathophysiologic consequences of fatal bacteremic shock. In this study, we investigated the effects of vesnarinone in a murine model of lethal endotoxemia induced by lipopolysaccharide (LPS). Eight-week-old female BALB/c mice were given 300 or 400 micrograms of LPS, and 50 or 100 mg/kg of vesnarinone was administered by oral gavage and/or 10 or 30 micrograms of vesnarinone was given intra peritoneally. Vesnarinone prolonged the median survival time and reduced lethality when given at the same time as the LPS injection. However, vesnarinone did not have a beneficial effect when administered 2 hours after LPS treatment. Plasma TNF-alpha reached a maximum level 1 hour after LPS challenge, and vesnarinone reduced the plasma level of TNF-alpha, when administered at the same time as LPS injection. Vesnarinone had protective effects against lethal endotoxemia; these effects were considered to be due to the suppression of TNF-alpha production. These findings suggest that vesnarinone may be a promising agent for the treatment of bacterial sepsis and shock.

Functional roles of terminal glycomoieties in varicella-zoster virus infection

Terminal glycomoieties of varicella-zoster virus glycoproteins were characterized by their reactivity with lectins and glycosidases, and the functional roles of terminal sugars were analyzed by cell-free virus infectivity. Terminal glycan structures of gpl possessed sialic acid linked alpha (2-3) to galactose of O-linked glycan and galactose-beta (1-4)-N-acetylglucosamine of N-linked glycan. Those of the putative gpIV possessed galactose-beta (1-4)-N-acetylglucosamine of N-linked glycan. Both glycoproteins had mannose alpha (1-3, 6, or 2) linked to mannose in their glycans. Their biological functions on cell-free virus infectivity were assessed by using lectins and exoglycosidases. Sialic acid of glycans on both the viral envelope and the cell surface had a negative effect on infectivity, and the latter had a larger effect on infectivity than the former. Maackia amurensis agglutinin, which recognizes sialic acid, enhanced infectivity more than expected from the simple neutralization of the negative effects of sialic acids between cells and virus. alpha-Mannosidase and alpha-glucosidase treatments of virus significantly reduced infectivity but those of cells did not. Therefore, alpha-mannose and alpha-glucose residues on the viral envelope had functional roles in cell-free virus infection. Inactivation of virus infectivity by concanavalin A was mainly due to the blocking of functional roles of terminal alpha-mannose and alpha-glucose residues of viral glycoproteins.

E-cadherin and alpha-catenin expression in human esophageal cancer

Intercellular adhesion of the epithelial tissue is mainly regulated by the E-cadherin (E-cad) molecule. alpha-Catenin (alpha-cat) is one of the E-cad-associated cytoplasmic proteins that forms a linkage to the cytoskeleton and regulates E-cad function. To investigate the mechanism of dysfunction in cell-cell adhesion in cancerous tissues, we examined E-cad and alpha-cat expression by immunohistochemical staining on 46 human esophageal cancers using our specific monoclonal antibodies. By grading of E-cad and alpha-cat expression as uniformly positive (+), heterogeneous (+/-), or uniformly negative (-), the 46 tumors could be classified into 9 (20%) E-cad(+)/alpha-cat(+), 15 (33%) E-cad(+/-)/alpha-cat(+/-), 21 (46%) E-cad(+/-)/alpha-cat(-), and 1 (2%) E-cad(-)/alpha-cat(-). Twenty-five (54%) of the 46 tumors showed a similar expression of both molecules, while the other 21 tumors (46%) showed E-cad(+/-)/alpha-cat(-). Thus, although the expression of alpha-cat was significantly correlated with that of E-cad, in some tumors the reduction of alpha-cat was greater. Regarding the clinicopathological features, the reduction of alpha-cat expression, as well as that of E-cad, was significantly associated with tumor dedifferentiation, infiltrative growth, and lymph node metastasis (P < 0.01). Furthermore, the frequency of lymph node metastasis in E-cad(+/-)/alpha-cat(-) tumors was significantly higher (90%) than in E-cad(+)/alpha-cat(+) tumors (22%) (P < 0.01) or in E-cad(+/-)/alpha-cat(+/-) tumors (47%) (P < 0.05). These results suggest that not only E-cad but also alpha-cat are important regulators of intercellular adhesion and that alpha-cat is also involved in invasion and metastasis. In particular, reduction of alpha-cat expression is more correlated with invasive phenotype and lymph node metastasis than E-cad expression in human esophageal cancer.