Intracellular transport of basement membrane-type heparan sulphate proteoglycan in adenoid cystic carcinoma cells of salivary gland origin: an immunoelectron microscopic study

ACC3, a human adenoid cystic carcinoma cell system of salivary gland origin, is able to synthesize and secrete a large amount of basement membrane molecules in vitro. To define the ultrastructural secreting pathway of these molecules, we immunolocalized heparan sulphate proteoglycan (HSPG) in ACC3 for 7 days of culture. In the early stage of culture, the main compartments immunolabelled were rough endoplasmic reticulum (rER) and small secretory vesicles. From days 3 to 4 after plating, it was noticed that HSPG was localized in partially dilated spaces of the perinuclear, rER and Golgi cisternae and in lysosomes or those fused with multivesicular bodies and endosomes. On and after day 5, almost every Golgi apparatus showed marked dilatation of the cisternae and HSPG was immunolocalized in these dilated spaces. In the later stage of culture, autophagic vacuoles or secondary lysosomes, which were simultaneously labelled for HSPG and cathepsin D, were accumulated in the cytoplasm. HSPG deposition in the intercellular space was clearly demonstrated from day 1 and increased during the culture. The results indicate that ACC3 cells have an enhanced turnover cycle for HSPG: not only its biosynthesis but also degradation of both endogenous or exogenous HSPG. Such intracellular events may be reflected in the characteristic histology and biological behaviour of adenoid cystic carcinomas.

Effects of FR139317 on renal responses to acute nitric oxide blockade in anaesthetized rats

1. Effects of FR139317, an endothelin ETA receptor antagonist, on renal haemodynamic and excretory responses to acute nitric oxide (NO) blockade were examined using anaesthetized rats. 2. Intrarenal arterial infusion of NG-nitro-L-arginine (NOARG), the NO synthase inhibitor, at a rate of 40 micrograms/kg per min, produced a significant decrease in renal blood flow, with no change in systemic blood pressure. There were significant decreases in urine flow and urinary excretion of sodium during infusion of NOARG. In animals pretreated with FR139317, similar renal responses to the NOARG infusion were observed. 3. These results suggest that an action of endothelin-1 via ETA receptors does not greatly contribute to the renal haemodynamic and excretory responses to acute blockade of renal NO production.

Genomic organization of human and mouse genes for vascular endothelial growth factor C

We report here the cloning and characterization of human and mouse genes for vascular endothelial growth factor C (VEGF-C), a newly isolated member of the vascular endothelial growth factor/platelet-derived growth factor (VEGF/PDGF) family. Both VEGF-C genes comprise over 40 kilobase pairs of genomic DNA and consist of seven exons, all containing coding sequences. The VEGF homology domain of VEGF-C is encoded by exons 3 and 4. Exons 5 and 7 encode cysteine-rich motifs of the type C6C10CRC, and exon 6 encodes additional C10CXCXC motifs typical of a silk protein. A putative alternatively spliced rare RNA form lacking exon 4 was identified in human fibrosarcoma cells, and a major transcription start site was located in the human VEGF-C gene 523 base pairs upstream of the translation initiation codon. The upstream promoter sequences contain conserved putative binding sites for Sp-1, AP-2, and NF-kappaB transcription factors but no TATA box, and they show promoter activity when transfected into cells. The VEGF-C gene structure is thus assembled from exons encoding propeptides and distinct cysteine-rich domains in addition to the VEGF homology domain, and it shows both similarities and distinct differences in comparison with other members of the VEGF/PDGF gene family.

Effect of respiratory acidosis on body movements in the chronically instrumented fetal lamb

BACKGROUND

In respiratory acidosis, it is reported that the fetal breathing movements as well as the fetal heart rate variability increase. As the increase of these two kinds of fetal activities is occasionally observed in normal conditions, it is difficult to distinguish respiratory acidosis and normal conditions by mere observation of these activities. As the third diagnostic variable, if a different fetal body movement response to respiratory acidosis is observed, it would be helpful for better diagnosis in combination with other activities. We investigated the effect of respiratory acidosis on body movements in the chronically instrumented fetal lamb.

METHODS

A total of four experiments were performed on four ewes. Respiratory acidosis was induced in the fetus by maternal administration of a high carbon dioxide gas mixture for 1 hour. Fetal body movements were observed by real-time ultrasonography. The frequency of body movements was expressed as the number of each movement in a 30-minute period.

RESULTS

The mean pCO2 increased from 42.9 +/- 4.9 mmHg to 62.9 +/- 14.8 mmHg, and the mean pH decreased from 7.368 +/- 0.04 to 7.209 +/- 0.04 during the experiments. The frequency of fetal body movements significantly decreased. The percentage reduction of these movements of the same fetus during the experiments as compared to the control periods were as follows; the high-frequency movements, 89.2 +/- 9.7%; the rolling movements, 55.6 +/- 13.5%; the simple movements, 78.3 +/- 18.4%.

CONCLUSIONS

Normoxemic respiratory acidosis, which is reported to increase fetal breathing movements, caused a marked reduction in fetal body movements. These findings suggest that the ultrasonographic dissociation of fetal behaviors in respiratory acidosis would be potentially helpful in the diagnosis of impending fetal jeopardy.

VEGF-C receptor binding and pattern of expression with VEGFR-3 suggests a role in lymphatic vascular development

The vascular endothelial growth factor family has recently been expanded by the isolation of two new VEGF-related factors, VEGF-B and VEGF-C. The physiological functions of these factors are largely unknown. Here we report the cloning and characterization of mouse VEGF-C, which is produced as a disulfide-linked dimer of 415 amino acid residue polypeptides, sharing an 85% identity with the human VEGF-C amino acid sequence. The recombinant mouse VEGF-C protein was secreted from transfected cells as VEGFR-3 (Flt4) binding polypeptides of 30–32x10(3) Mr and 22–23x10(3) Mr which preferentially stimulated the autophosphorylation of VEGFR-3 in comparison with VEGFR-2 (KDR). In in situ hybridization, mouse VEGF-C mRNA expression was detected in mesenchymal cells of postimplantation mouse embryos, particularly in the regions where the lymphatic vessels undergo sprouting from embryonic veins, such as the perimetanephric, axillary and jugular regions. In addition, the developing mesenterium, which is rich in lymphatic vessels, showed strong VEGF-C expression. VEGF-C was also highly expressed in adult mouse lung, heart and kidney, where VEGFR-3 was also prominent. The pattern of expression of VEGF-C in relation to its major receptor VEGFR-3 during the sprouting of the lymphatic endothelium in embryos suggests a paracrine mode of action and that one of the functions of VEGF-C may be in the regulation of angiogenesis of the lymphatic vasculature.

Syntheses and biological activities of dihydro-5,6-dehydrokawain derivatives

The syntheses and biological activities of dihydro-5,6-dehydrokawain derivatives against plant pathogenic fungi and termites were investigated. Dihydro-5,6-dehydrokawain was isolated by a simple method without chromatography from the leaves of Alpinia speciosa K. SCHUM. The white crystalline compound obtained was identified as dihydro-5,6-dehydrokawain (1) by instrumental analyses. 4-Hydroxy-6-(2-phenylethyl)-2H-pyran-2-one (3) was prepared by hydrolyzing dihydro-5,6-dehydrokawain. Three dihydro-5,6-dehydrokawain derivatives were synthesized by reacting 3 with phosphoric agents. Among the synthesized compounds, dimethyl [6-(2-phenylethyl)-2-oxo-2H-pyran-4-yl]phosphorothionate (4) had the strongest antifungal activity of 91% at 100 ppm against Corticium rolfsii.

Synthesis and antifungal activity of cinnamic acid esters

Cinnamic, p-coumaric and ferulic acids were isolated from pineapple stems (Ananas comosus var. Cayenne). Twenty-four kinds of esters were prepared from these acids, alcohols and the components of Alpinia. Isopropyl 4-hydroxycinnamate (11) and butyl 4-hydroxycinnamate (12) were found to have almost the same effectiveness in antifungal activity against Pythium sp. at 10 ppm as that of the commercial fungicide iprobenfos (kitazin P).

[Recent features of parasites detected from clinical specimens]

It is generally considered that we have already been through with problems caused by various kinds of parasites which had once raged throughout the country. On the contrary to our common concept, we occasionally encounter some kinds of parasites in a laboratory as well as in clinical fields, which have become unfamiliar to us in these days. Parasitic diseases are in the first place, proper and limited to certain local regions, but the present situation has been greatly changed. Nowadays, specific parasites are no longer limited to polluted areas, but also they can be detected in any part of the world owing to facilitated transportations and a promoted international exchange of people. A recent gourmet boom is also one of the causes of infection as seen in anisakiasis. This study was conducted on the investigation of parasites detected from clinical specimens in our laboratory during the period from 1989 to 1993. 1) The following parasites were detected : (1) Strongyloides stercoralis, (2) Giardia lamblia, (3) Diphyllobothrium latum, (4) Schistosoma mansoni, (5) Entamoeba histolytica, (6) Necator americanus, (7) Isospora belli. 2) Strongyloides stercoralis was detected at the highest frequency. This result gives an account of high prevalence of the parasite among the inhabitants in Okinawa. In addition, the agar plate medium method which has been newly adopted has definitely led to far-advanced results for detection of this parasite. 3) Schistosoma mansoni and Necator americanus were found from foreigners one of whom was a Tanzanian and the other was a Dominican. 4) Isospora belli was found from those compromised cases such as ATL and AIDS.

A novel human serum lectin with collagen- and fibrinogen-like domains that functions as an opsonin

Collectins are C-type animal lectins with both collagenous and carbohydrate recognition domains and are involved in the first line host defense against pathogens. We report here a novel Ca(2+)-dependent and GlcNAc-binding lectin consisting of subunits of 35 kDa (P35) with a collagen-like sequence. When P35 is isolated from human serum, it forms a homopolymer by means of intermolecular disulfide bonding, as is the case with collectins. P35 cDNA was cloned from a human liver cDNA library, and the deduced amino acid sequence of 313 residues revealed that the mature form of P35 consists mainly of collagen- and fibrinogen-like domains. The latter contained two potential Ca(2+)-binding sites that may be involved in carbohydrate binding. The overall sequence of P35 was highly homologous to porcine ficolins alpha and beta. Northern blots of various human tissues showed that the major product of the 1.3-kilobase-long P35 transcript is expressed in liver. P35 enhanced phagocytosis of Salmonella typhimurium by neutrophils, suggesting an opsonic effect via the collagen region. P35 was found to bind to GlcNAc-conjugated bovine serum albumin, a neoglycoprotein, as well as to neoglycolipids containing complex-type oligosaccharides derived from glycoproteins, suggesting that P35 recognizes GlcNAc residues such as those found in microbial glycoconjugates and complex-type oligosaccharides. Therefore, P35 represents a new type of GlcNAc-binding lectin with structural and functional similarities to collectins involved in innate immunity.

Pneumocephalus caused by fistulas of the mastoid air cells treated with a temporoparietal fascial flap

Using a temporoparietal fascial flap and hydroxyapatite ceramics, we treated a patient for complications after a neurosurgical operation for glossopharyngeal neuralgia. These consisted of pneumocephalus and cerebrospinal fluid rhinorrhea resulting from fistulas of mastoid air cells associated with a subcutaneous dead space. By means of the temporoparietal fascial flap, we were able to fill the dead space and reinforce the repaired dural and mastoid lesion as well. Hydroxyapatite ceramics were also useful for closing the mastoid air cell fistulas.

The Escherichia coli G-fimbrial lectin protein participates both in fimbrial biogenesis and in recognition of the receptor N-acetyl-D-glucosamine

The gafD gene encoding the N-acetyl-D-glucosamine-specific fimbrial lectin (adhesin) protein GafD of uropathogenic Escherichia coli was cloned and subjected to genetic analysis. The corresponding gene product was isolated as a MalE fusion protein. The lectin gene was identified with the aid of deletion mutagenesis; mutations in gafD impaired either receptor binding or both receptor binding and fimbria production, depending on the mutation created. All mutants converted to wild-type expressors when complemented in trans with the cloned intact gafD gene. The predicted 354-amino-acid sequence of GafD, deduced from the nucleotide sequence, is closely related to those of the fimbria-associated F17-G and F17b-G proteins coded for by enterotoxigenic and invasive E. coli strains. Isolated GafD was shown to recognize N-acetyl-D-glucosamine by virtue of specific binding to an immobilized receptor, thus proving directly that GafD is a sugar-binding protein. Our results indicate that GafD as such is sufficient for receptor recognition and that the protein also participates in fimbrial biogenesis.

Evidence for functional polymorphism of the spvR gene regulating virulence gene expression in Salmonella

The expression of Salmonella enterica spv virulence genes was studied in serovariants Dublin and Typhimurium using Western blotting (immunoblotting), spv-lacZ operon fusions and Northern blotting. The SpvA protein was detected in immunoblots from stationary phase cultures of Dublin but not from the corresponding cultures of Typhimurium. Transcriptional measurements, using a spvA-lacZ operon fusion, indicated 8-10 times higher spvA transcription in Dublin. In an isogenic Escherichia coli chromosomal background, virulence plasmids from various Dublin strains systematically had a significantly higher induction level of the spvA-lacZ operon fusion than virulence plasmids from Typhimurium strains. The cloned spvR transcriptional activator gene of Dublin strain 2229 was found to activate both spvR-lacZ and spvA-lacZ operon fusions, as well as to raise spv mRNA levels in E. coli TG1. In contrast, the corresponding cloned gene of Typhimurium strain SL2965 possessed a lower induction potential and required higher spvR gene dosage for activation. A comparison of the nucleotide sequences of spvR genes from two Dublin and four Typhimurium strains revealed conserved, serovariant-associated basepair substitutions. Our results indicate that the spv virulence gene cluster possesses different functional alleles of the regulator gene spvR. This finding has important consequences for comparative studies of regulation and virulence in different serovariants of Salmonella.

[Clinical significance of ultrasonographic screening for Down syndrome in the second trimester]

OBJECTIVE

This study was undertaken to evaluate the clinical significance of ultrasonographic screening for the detection of Down syndrome in the second trimester of pregnancy of Japanese women.

MATERIALS AND METHODS

BPD (biparietal diameter), FL (femur length), BPD/FL ratio and M/E FL (measured/expected femur length) ratio were measured in 734 normal second-trimester fetuses and 13 consecutive Down syndrome fetuses undergoing genetic amniocentesis mainly for advanced maternal age.

RESULTS

Two fetuses with Down syndrome had small BPD, three fetuses had a short femur length, four fetuses had a high BPD/FL ratio and four fetuses had a low M/E FL ratio. A cutoff value of 1.5SD below the mean value for the normal populations for BPD and FL, that of above 1.5SD for BPD/FL ratio, and that of 0.91 or less for M/E FL ratio yielded a sensitivity of 15.4, 23.1, 30.8 and 30.8% and false positive rates of 2.7, 6.0, 5.7 and 11.4%, respectively.

CONCLUSION

The ultrasonographic measurements of femur length for the screening of Down syndrome in the Japanese population revealed the low discriminative ability reported in recent studies conducted in Western countries. Further investigation would be necessary to apply it as the routine screening method for Down syndrome in clinical practice.

Mannose-binding protein recognizes glioma cells: in vitro analysis of complement activation on glioma cells via the lectin pathway

The lectin pathway is a novel pathway for activation of the complement cascade, which is initiated by the binding of mannose-binding protein (MBP) to its carbohydrate ligands. We investigated whether the complement system was activated in vitro by glioma cells through this pathway to the C3 level. MBP was found to bind to all six glioma cell lines tested by using flow cytometric analysis. Binding of a complex of MBP-associated serine protease and MBP was observed in two of the cell lines examined, thereby resulting in C4 consumption. Activation of C3 was hemolytically evaluated in these two lines. C3 consumption was also observed in one. Based on these results, it is likely that recognition by MBP followed by complement activation occurs in certain glioma cell lines.

[A case-control study of risk factors for cerebral hemorrhage in Hirara-City, Okinawa Prefecture]

While the mortality rate of cerebral hemorrhage of Okinawa Prefecture is the lowest in Japan, the presence of a high incidence rate for cerebral hemorrhage has been pointed out in Hirara-city, Okinawa Prefecture. In order to develop an effective counter-measure, a case-control study of risk factors for cerebral hemorrhage was performed. Cases were 62 residents in Hirara city aged 40-69 years who had experienced cerebral hemorrhage between April 1987 through March 1992. From the 62 cases interviewed, responses were obtained from 49 cases. Controls were 147 residents without a history of stroke who were matched to cases individually by sex and age (control/case ratio = 3). From the 49 cases, 28 cases who had participated in residential mass health examinations before experiencing the cerebral hemorrhage, were matched individually sex and age with different randomly selected controls (control/case ratio = 10). From conditional logistic regression analysis of the interview survey data, history of hypertension, interruption of hypertension therapy, family history of stroke, long working hours, overwork and difficulty of taking a day-off each week were strongly related to increased risk of cerebral hemorrhage. Smoking, preference for salty taste and habitual drinking, also, elevated risk slightly. From analysis of the residential mass health examination data, high blood pressure was found to be strongly associated with cerebral hemorrhage, while serum cholesterol was inversely related.

Role of rpoS in the regulation of Salmonella plasmid virulence (spv) genes

Salmonella plasmid virulence (spv) genes are organized into two transcriptional units: one formed by the spvR gene and the other by the spvA, spvB, spvC and spvD genes. Transcription of both units is activated by SpvR, a regulatory protein of the LysR family. The effect of RpoS, a stationary phase-associated sigma factor, on the expression of spv genes was studied using lacZ transcriptional fusions to spvR and spvA in wild-type and rpoS Escherichia coli backgrounds. Mutant and wild-type SpvR proteins were expressed in trans from a multicopy plasmid. The results show that the combined action of rpoS and spvR is necessary for transcription of spvA and that this combination also enhances transcription of spvR. Interestingly, spvR can also be transcribed in an alternative manner, i.e. in the absence of rpoS or spvR or both. The possible role for SpvR as a repressor of its own transcription is discussed.

[Differentiation of benign from malignant pulmonary nodules with the digital analysis of computed radiography]

To differentiate benign pulmonary nodules from malignant nodules, digital analysis of computed radiography (CR) was performed retrospectively. A total of 142 histologically or clinically proved cases were studied. Digital analysis was performed using the method of gradient processing reported by Sherrier et al. Gradient number with and without background trend correction and gradient number corrected by L-value were obtained from the raw data of CR. The mean gradient of 93 malignant nodules was significantly different from that of 49 benign nodules. The analysis of gradient number without background trend correction and L-value correction was most sensitive. Seven radiologists evaluated these nodules as to benign or malignant, status, degree of calcification and homogeneity. A correlation was found between the detectability of benign nodules and degree of calcification. In conclusion, CR-gradient analysis is useful as a screening test to differentiate benign nodules from malignant ones.

Transcriptional regulation of Salmonella enterica virulence plasmid genes in cultured macrophages

The plasmid-carried spv genes promote virulence of salmonellae in mice by allowing bacterial growth in the reticuloendothelial tissue. When the bacteria are cultivated under normal laboratory conditions the spv genes appear dormant. This communication explores the transcriptional regulation of spv genes within murine macrophage-like J774-A.1 cells utilizing a new reporter system. Transcriptional fusions were constructed between promoter elements of the Salmonella enterica var. Typhimurium spv genes and the KS71A fimbrial gene cluster. The expression of KS71A fimbriae in fusion-carrying Escherichia coli strains was found to be under the control of the transcriptional activator gene spvR. In strains overproducing SpvR, KS71A fimbriae were assembled on the bacterial cell surface and could be detected by bacterial agglutination or immunofluorescence of intact bacteria; the reporter activity was quantified by estimating the percentage of fluorescent bacteria and by immunoblotting of cell lysates. The activity of the reporters, when transformed into the parent Typhimurium TML R66, was low and revealed less than 0.3% fimbriated cells under in vitro culture conditions. A 15-30-fold increase in fimbriation was observed when the bacteria were cultivated within J774-A.1 cells. No such increase occurred when the reporter fusions were transformed into TML R66 cured of the virulence plasmid. Insertional inactivation of the spvR gene of the virulence plasmid in Typhimurium TML R66 also abolished induction, whereas corresponding inactivation of spvA or spvB did not reduce induction. No increase in reporter activity was obtained in Typhimurium of line Q1, which is naturally avirulent for mice, although the strain was provided with virulence plasmid pEX102 of line TML R66. We conclude that the intracellular environment of J774-A.1 cells induces the spv genes and that this induction requires gene functions of both the bacterial chromosome and the virulence plasmid.

Differential requirement for humoral factors for IL-2R expression of murine T cell subsets, Th1, Th2, and CD8Th clones

Three types of alloreactive T helper (Th) cell clones, Th1, Th2, and CD8Th, were examined for the requirement of costimulatory factors for IL-2 receptor (IL-2R) expression and proliferation. When stimulated with allogeneic spleen adherent cells, these Th cell clones all expressed IL-2R strongly, whereas they expressed the receptor only weakly when subjected to allogeneic B cell stimulation. The addition of partially purified IL-2RIF to Th1, Th2, or CD8Th cell clones stimulated with B cell antigen-presenting cells increased the IL-2R expression of Th1 and CD8Th cell clones but not of the Th2 cell clone. Conversely, IL-1 up-regulated IL-2R expression of Th2 cell clones stimulated with B cell APC but not of Th1 and CD8Th cell clones. Neither IL-2RIF nor IL-1 induced IL-2R expression of unstimulated Th cell clones. IL-2R expressed in the presence of these costimulators contributed to IL-2-dependent proliferation of these cells. Thus, the expression of IL-2R was indicated to be regulated differently in three types of Th cell subsets through different cytokines.

Synthesis and structure-activity study of protease inhibitors. V. Chemical modification of 6-amidino-2-naphthyl 4-guanidinobenzoate

By developing 6-amidino-2-naphthyl 4-guanidinobenzoate (I, FUT-175) as a basic structure, its various derivatives were synthesized and their inhibitory activities on trypsin, plasmin, kallikrein, thrombin, C1r and C1s as well as on complement-mediated hemolysis were examined. The protective effect of these compounds on complement-mediated Forssman shock was also examined in guinea pigs. 6-Amidino-2-naphthyl 4-[(4,5-dihydro-1H-imidazol-2-yl)amino]-benzoate (41, FUT-187) was found to be a suitable compound for oral administration with anti-complement activity superior to that of compound I.

The virulence plasmid does not contribute to growth of Salmonella in cultured murine macrophages

The virulence plasmid, characteristic of many serovars of Salmonella sp., and specifically its spv genes, promote intracellular growth of the bacteria in the liver and spleen and are essential for the virulence of these Salmonella serovars in the mouse. In an attempt to establish an in vitro model for studying its function, we evaluated its effect on the intracellular growth of the bacteria in macrophages in culture. We used a number of different macrophage-like cell lines (J774-A.1, IC-21 and PU5-1.8), as well as peritoneal or splenic macrophages from genetically Salmonella-sensitive (Itys, BALB/c) or resistant (Ityr, C3H/HeN) mice, and at different states of activation, stimulated in vivo or in vitro with lipopolysaccharide and/or recombinant gamma interferon. These were found to differ in their ability to suppress or sustain intracellular growth of several Salmonella serovars, but in all cases the growth was independent of the spv genes.

A new alpha-helical coiled coil protein encoded by the Salmonella typhimurium virulence plasmid

A new protein of Salmonella typhimurium was identified and characterized. The gene (tlpA) encoding this protein (TlpA) was isolated from the large virulence-associated plasmid of S. typhimurium and sequenced in order to predict the primary structure of TlpA. tlpA encodes a 371-amino acid soluble protein with a calculated M(r) of 41600 and pI of 4.63. Secondary structure predictions and sequence statistics of TlpA indicated a predominant alpha-helical configuration and presence of heptapeptide repeat motifs characteristic of coiled coil proteins. Purified TlpA was shown to have biochemical properties similar to those of coiled coil proteins, including adoption of an alpha-helical configuration and a tendency to form homodimers. Furthermore, TlpA possessed heat resistance, evidence for a chain register and altered mobility in urea/sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels which are characteristics of tropomyosins. TlpA shows 32% overall sequence similarity with rat cardiac myosin and 36% similarity with horse platelet beta-tropomyosin over 226 residues, whereas selected regions possessed significant sequence identities with myosins, tropomyosins, and alpha-helical surface proteins of Streptococcus pyogenes. Our results indicate that TlpA represents a new member of prokaryotic coiled coil proteins.

[Detection of Epstein-Barr virus DNA in salivary gland tumors]

To evaluate the relations between salivary gland tumors and Epstein-Barr virus (EBV), the levels of EBV-related antibodies were examined, and detection of EBV nuclear antigen (EBNA) and EBVDNA in tumor tissue was attempted by the anti-complement immunofluorescence technique and polymerase chain reaction, respectively. The mean VCA-IgG antibody level was increased to 925 (80-2560) in Warthin's tumor, 496 (40-2560) in mucoepidermoid tumor, and 206 (40-640) in pleomorphic adenoma. The positive rate of EA-IgG was high in Warthin's and mucoepidermoid tumors. VCA-IgA antibody was positive in 2 of the 7 cases of Warthin's tumor. EA-IgA antibody was negative in all cases. EBVDNA was detected in 7 of the 7 cases of Warthin's tumor, 3 of the 5 cases of mucoepidermoid tumor, and 2 of the 26 cases of pleomorphic adenoma. A relationship between Warthin's tumor and EBV was suggested by the 100% detection rate of the viral DNA.