PCR method is essential for detecting Mycobacterium tuberculosis in oral cavity samples

Tuberculosis is a re-emerging infectious disease, and infection by Mycobacterium tuberculosis has been increasing in immunocompromised hosts, including elderly persons. M. tuberculosis-infected persons may receive dental treatment. To evaluate the risk of M. tuberculosis infection in dental clinics, we examined the detection rates of M. tuberculosis in sample of mixed saliva, dental plaque, extracted teeth, caries lesions, and denture plaque by nested polymerase chain reaction (PCR). The detection rates by PCR in samples from mixed saliva, dental plaque, caries lesions and denture plaque obtained from tuberculosis patients were 98.0%, 92.0%, 89.0%, and 100%, respectively. The detection rates by the culture method were 17.3%, 2.0%, 0%, and 0%, respectively. M. tuberculosis also was detected from the nontuberculous mycobacteria-infected group. Strains of Actinomyces naeslundii, Porphyromonas gingivalis, and Fusobacterium nucleatum inhibited the growth of clinical strains of M. tuberculosis, but strains of Streptococcus mutans, Streptococcus sanguinis, and Actinobacillus actinomycetemcomitans did not. The present study concludes that the PCR method is essential for detecting M. tuberculosis in oral samples.

Trazodone hydrochloride attenuates thermal hyperalgesia in a chronic constriction injury rat model

BACKGROUND AND OBJECTIVE

Trazodone hydrochloride is used in the treatment of neuropathic pain. However, the analgesic effects of trazodone on neuropathic pain are controversial. The study was undertaken to determine the analgesic effect of trazodone on a chronic constriction injury model.

METHODS

We tested the effect of trazodone on thermal hyperalgesia due to a chronic constriction injury of the sciatic nerve in rats and examined the effects of lesions in the descending and ascending serotonergic system induced by 5,7-dihydroxytriptamine (5,7-DHT).

RESULTS

The analgesic effects of trazodone showed a clear dose dependency. Furthermore, the analgesic effect of trazodone was observed in rats injected with 5,7-DHT into the dorsal raphe nucleus and medial raphe nucleus.

CONCLUSIONS

The results suggest that a mainly serotonergic descending pain control pathway mediates the analgesic effects of trazodone.

Sonographic features of hepatic artery calcification in chronic renal failure

PURPOSE

Little is known about radiological aspects of hepatic artery calcification. For this reason, the sonographic features of calcified hepatic arteries were studied in patients with chronic renal failure who frequently develop tissue calcification due to hyperparathyroidism.

MATERIAL AND METHODS

Ultrasound was performed in 314 patients on dialysis who underwent examination of the liver, spleen and kidney twice in the past 4 years and were reevaluated with particular attention to acoustic shadowing. Abdominal CT was carried out in 219 of these 314 patients, and ultrasound findings were reevaluated with reference to CT findings.

RESULTS

A large acoustic shadow was seen in the hilum that corresponded to the calcified hepatic artery on CT in 8 patients, and in another 9, a similar large shadow was seen in the hilum without CT confirmation. Acoustic shadows of various sizes were definitely or most likely due to arterial calcification within the liver in 36 patients. The strength of shadow depended on the angle at which the ultrasound beam hit the artery. Probable calcification of small arteries accompanying portal veins was seen in 70 patients. These changes are different from those due to pneumobilia and biliary tract diseases.

CONCLUSION

Calcification of the hepatic artery can be identified by its acoustic shadow.

Sonographic features of hepatic artery calcification in chronic renal failure

PURPOSE

Little is known about radiological aspects of hepatic artery calcification. For this reason, the sonographic features of calcified hepatic arteries were studied in patients with chronic renal failure who frequently develop tissue calcification due to hyperparathyroidism.

MATERIAL AND METHODS

Ultrasound was performed in 314 patients on dialysis who underwent examination of the liver, spleen and kidney twice in the past 4 years and were reevaluated with particular attention to acoustic shadowing. Abdominal CT was carried out in 219 of these 314 patients, and ultrasound findings were reevaluated with reference to CT findings.

RESULTS

A large acoustic shadow was seen in the hilum that corresponded to the calcified hepatic artery on CT in 8 patients, and in another 9, a similar large shadow was seen in the hilum without CT confirmation. Acoustic shadows of various sizes were definitely or most likely due to arterial calcification within the liver in 36 patients. The strength of shadow depended on the angle at which the ultrasound beam hit the artery. Probable calcification of small arteries accompanying portal veins was seen in 70 patients. These changes are different from those due to pneumobilia and biliary tract diseases.

CONCLUSION

Calcification of the hepatic artery can be identified by its acoustic shadow.

Acute renal failure and hearing loss due to sodium bromate poisoning: a case report and review of the literature

Acute renal failure with hearing loss due to sodium bromate intoxication is described. A 48-year-old woman who ingested permanent wave neutralizer in a suicide attempt and developed anuria was admitted to our hospital for hemodialysis. Bromate intoxication was suspected and hemodialysis was carried out; she required maintenance dialysis 3 times a week. Irreversible severe sensorineural hearing loss continued and peripheral polyneuropathy developed in the lower limbs. We measured the concentration of bromine in the serum before and after the first hemodialysis and found its removal rate to be 61.3%. This is the first report that proved the utility of hemodialysis for bromate intoxication in a clinical setting.

Mycobacterium leprae and leprosy: a compendium

Leprosy is a chronic infectious disease caused by Mycobacterium leprae, which was discovered by G.H.A. Hansen in 1873. M. leprae is an exceptional bacterium because of its long generation time and no growth in artificial media. Entire sequencing of the bacterial genome revealed numerous pseudogenes (inactive reading frames with functional counterparts in M. tuberculosis) which might be responsible for the very limited metabolic activity of M. leprae. The clinical demonstration of the disease is determined by the quality of host immune response. Th1-type immune response helps to kill the bacteria, but hosts are encroached upon when Th2-type response is predominant. The bacteria have affinity to the peripheral nerves and are likely to cause neuropathy. M. leprae/laminin-alpha2 complexes bind to alpha/beta dystroglycan complexes expressed on the Schwann cell surface. WHO recommends a chemotherapy protocol [multidrug therapy (MDT)] which effectively controls the disease and contributes to the global elimination program. Leprosy has been stigmatized throughout history, and recent topics regarding the disease in Japan are also discussed.

Regulation of endometrial prostaglandin F(2alpha) synthesis during luteolysis and early pregnancy in cattle

Luteal regression is caused by a pulsatile release of prostaglandin (PG) F(2alpha) from the uterus in the late luteal phase in most mammals including cattle. Although it has been proposed in ruminants that pulsatile PGF(2alpha) secretion is generated by a positive feedback loop between luteal and/or hypophyseal oxytocin and uterine PGF(2alpha), the bovine endometrium may possess other mechanisms for initiation of luteolytic PGF(2alpha) secretion. It has been recently demonstrated that tumor necrosis factor-alpha (TNF-alpha) stimulates PGF(2alpha) output from bovine endometrial tissue not only during the follicular phase but also during the late luteal phase, suggesting that TNF-alpha is a factor in the initiation of luteolysis in cattle. Furthermore, our recent study has shown that IFN-tau suppresses the action of TNF-alpha on PGF(2alpha) synthesis by the bovine endometrium in vitro, suggesting that IFN-tau plays a luteoprotective role by inhibiting TNF-alpha-induced PGF(2alpha) production in early pregnancy. On the other hand, factors other than oxytocin or TNF-alpha have also been suggested to be involved in the regulation of PGF(2alpha) synthesis by bovine endometrium. The purpose of this review is to summarize our current understanding of the endocrine mechanisms that regulate the timing and pattern of uterine PGF(2alpha) secretion during the estrous cycle and early pregnancy.

Functional morphology of adult female Culex quinquefasciatus midgut during blood digestion

The adult female Culex quinquefasciatus midgut comprises a narrow anterior and a dilated posterior region, with epithelia composed of a monolayer of adjacent epithelial cells joined at the apical portion by septate junctions. Densely packed apical microvilli and an intricate basal labyrinth characterise each cell pole. Our morphological studies suggest that, during blood digestion, the anterior midgut region also participates in an initial absorptive stage which is probably related to the intake of water, salts and other small molecules. This activity peaked by 6h after bloodmeal feeding (ABF) and ended approximately 18 h ABF, when the peritrophic membrane was already formed. After this time, absorption only occurred in the posterior region, with morphologic and biochemical evidence of high synthetic activity related to the secretion of proteases. Chymotrypsin, elastase, aminopeptidase, and trypsin reached their maximum activity at around 36 h ABF. Digestion products were apparently absorbed and transported to the basal labyrinth, from where they should be released to the hemolymph. At 72 h ABF, proteolysis had already ended and protein levels had returned to those observed before blood meal. The epithelium of the posterior region, however, did not return to its initial morphology, appearing quite disorganised. Additionally, from 48 h ABF onwards some epithelial cells showed morphological signals of apoptosis.

Immunomodulation by apoptosis-inducing caspases for an influenza DNA vaccine delivered by gene gun

Apoptosis-inducing caspases have been tested for immunomodulatory effect on a gene gun-delivered DNA vaccine which expresses influenza hemagglutinin. Attenuated murine caspase 2 and a chimera of murine caspase 2 prodomain and human caspase 3 strongly enhanced humoral and cell-mediated immune response to hemagglutinin when they were co-administered with an immunogen DNA. In contrast, wild-type caspases did not enhance the DNA-raised immune response. Caspase dose-dependent antibody response curve revealed that the antibody level was in inverse relation to the amount of administered caspase. These findings indicate that bland apoptosis of antigen-harboring cells can elicit enhanced immune responses. Extensive apoptosis interferes with the generation of immune response. Gene gun delivery involving caspases elicited type-2 immune responses that characterized with dominant IL-4 and IgG1 production. ELISPOT assays showed that CD4 T cells were preferentially activated, while CD8 T cell response remained at marginal level. Using attenuated caspases for gene gun DNA vaccination is a useful approach to amplify type-2 immune responses.

Tumour necrosis factor-alpha receptors are present in the corpus luteum throughout the oestrous cycle and during the early gestation period in pigs

To determine the physiological significance of tumour necrosis factor-alpha (TNFalpha) in the regulation of luteal functions in pig, this study was conducted to identify the presence of functional TNFalpha receptors in porcine corpora lutea (CL) throughout the oestrous cycle and the early gestation. The CL were isolated from pigs on days 4, 6, 8, 12 or 15 of the oestrous cycle (n=3; day 0 = oestrus) and days 15, 20 or 25 of gestation (n=3; day 0 = mating). A Scatchard analysis revealed the presence of a high-affinity binding site for TNFalpha in all samples (dissociation constant; 2.7 +/- 0.51 to 5.8 +/- 0.50 nM). The concentration of TNFalpha receptors was higher on day 15 of the oestrous cycle than on days 4 and 8 of the oestrous cycle (p < 0.05). Furthermore, TNFalpha receptor concentrations in the CL on days 15, 20 and 25 of gestation were significantly lower than on day 15 of the oestrous cycle (p < 0.05). On day 9 of the oestrous cycle, exposure of cultured luteal cells to 0.06-60 nM TNFalpha stimulated prostaglandin (PG) F2alpha and PGE2 secretion in a dose-dependent manner (p < 0.05). These results indicate that functional TNFalpha receptors are present in the porcine CL throughout the oestrous cycle and early gestation, and suggest that TNFalpha plays one or more physiological roles in regulating CL function throughout the oestrous cycle and the early gestation period. In addition, TNFalpha receptor concentration in the CL of the late luteal stage (day 15) of the oestrous cycle was higher than on the respective day in the early pregnant pig, suggesting that TNFalpha plays a role in accomplishing luteolysis in the porcine CL.

Correlation between the bronchial subepithelial layer and whole airway wall thickness in patients with asthma

BACKGROUND

The epithelial reticular basement membrane (Rbm) of the airway wall thickens in patients with asthma. However, whether the thickening parallels whole airway wall thickening, which limits airflow, is unknown. The aim of this study was to examine the correlation between the bronchial Rbm thickening and whole airway wall thickening in asthma. In addition, the association of Rbm and whole wall thickening with airflow obstruction was examined.

METHODS

Forty nine patients with asthma and 18 healthy control subjects took part in the study. The Rbm thickness was measured in bronchial biopsy specimens and whole airway wall thickness was assessed with high resolution computed tomographic (HRCT) scanning after pretreatment with oral steroids for 2 weeks and inhaled beta2 agonist to minimise reversible changes of the airway walls. The percentage airway wall area (WA%; defined as (wall area/total airway area) x 100) and percentage airway wall thickness (WT%; defined as [(ideal outer diameter - ideal luminal diameter)/ideal outer diameter] x 100) were determined from HRCT scans to assess whole airway wall thickness. Spirometric tests were also performed.

RESULTS

WA% and WT% were higher in patients with asthma than in healthy subjects. Both WA% and WT% were strongly correlated with Rbm thickness. Moreover, these three indices of airway wall thickness were inversely correlated with the percentage of predicted forced expiratory volume in 1 second in patients with asthma.

CONCLUSIONS

These findings indicate that Rbm thickening parallels whole airway wall thickening which can cause irreversible airflow obstruction in patients with asthma.

Iron-Mediated regulation of alkaline proteinase production in Pseudomonas aeruginosa

We analyzed the regulation by iron of alkaline proteinase (AP) production in Pseudomonas aeruginosa. Extracellular AP production was detected from the mid-logarithmic to the stationary phase by an antibody-based assay system, and was strongly repressed by iron in the medium. This repression was shown by Northern hybridization and primer extension to occur at the level of transcription. The primer extension analysis revealed that the start point of transcription of AP gene was the nucleotide position -84 from the start point of translation. Furthermore, we investigated whether this transcriptional repression involved PvdS protein. Using the mutant strain of pvdS, the alternative sigma factor gene revealed that the PvdS protein is required for the full expression of AP, and a previous study showed that expression of pvdS is also repressed by iron. Therefore, we thought that one mechanism of repression of AP production operated through reduction of the PvdS protein level. Purified AP decomposed the transferrin, and released iron from it. Purified AP added to the medium containing transferrin as the only iron source enhanced the growth of P. aeruginosa. Moreover, mutation in the AP gene decreased the growth rate in the medium containing the transferrin as the only iron source. These results clearly indicated that AP expression should occur in a free-iron-deficient environment and emphasized the importance of AP to iron acquisition in the infection site.

Ground-glass hepatocytes in fibrinogen storage disease in Japanese Black calves

This paper reports the occurrence of large intracytoplasmic inclusions observed in the hepatocytes of six Japanese Black calves showing clinical illness. These inclusions were round to elongated polyhedral in shape, with a consistently homogeneous glassy appearance. Hepatocytes with the inclusions had a ground-glass appearance. The inclusions were negative for the periodic acid-Schiff reaction and methenamine silver stain. Immunohistochemically, they were strongly positive for fibrinogen. Electron microscopy revealed that the inclusions consisted of granular material, showing moderate electron density and bounded by a unit membrane. On the external surface of the unit membrane, there were direct connections to cellular organelles, including the ribosomes and rough-surfaced endoplasmic reticulum. The results showed these inclusions to be entirely consistent with fibrinogen inclusions described in man. Hepatocellular fibrinogen storage disease, as identified in this study, has not previously been described in animals.

A case of hepatocellular carcinoma rupturing after angiography

We report a case of primary hepatocellular carcinoma (referred to as hepatocellular carcinoma below) apparently rupturing after angiography. The patient was a 62-year-old male who was admitted for the treatment of hepatocellular carcinoma. Ultrasonography (US) and computed tomography (CT) on admission showed a tumor occupying the entire left lobe of the liver and partly protruding outside the liver and a tumor embolus in the portal vein. We performed preoperative angiography, after which fever and abdominal discomfort appeared. Two days after the angiography, abdominal pain and a rapid increase in the size of the abdominal tumor were noted. US also revealed an unquestionable increase in the size of the tumor, leading to a diagnosis of intratumoral hemorrhage due to the rupture of hepatocellular carcinoma. Since child classification A, clinical stage I and ICG 11.7% indicated an adequate functional reserve of the liver, we performed an emergency operation. Laparotomy revealed that the tumor occupied almost the entire left lobe of the liver, partly protruded outside it, and was bleeding from part of its anterior surface. The volume of intra-abdominal hemorrhage was about 100 ml. A portal tumor embolus was present in the portal vein from the horizontal part to the trunk. We performed resection of the left and caudate lobes of the liver with removal of the portal tumor embolus. The resected specimens showed a hemorrhage in and around the tumor. We speculated that in a hepatocellular carcinoma that involves the surface of the liver and is complicated by tumor embolism of the portal vein, angiography could trigger the rupture of the carcinoma.

Age dependent aneuploidy and telomere length of the human vascular endothelium

RATIONALE

Aneuploidy and telomere length are two major parameters that have been associated with cellular senescence in vitro. In order to explore the role of aneuploidy and telomere length in aging of the human vasculature, we studied these two parameters in direct preparations of endothelial cells of the human abdominal aorta.

METHODS

Using fluorescent in situ hybridization on 'touch prep' slides, we evaluated aneuploidy of two autosomes (chromosomes 6 and 16) and sex chromosomes in non cultured endothelial cells of the abdominal aorta as a function of the donor's age.

RESULTS

We found that the frequency of aneuploidy of vascular endothelial cells significantly increased with age. This was expressed by age-dependent tetrasomy (r(s)=0.56, P=0.006 for chromosome 6; and r(s)=0.54, P=0.008 for chromosome 16), and age dependent loss of the Y chromosome (r(s)=0.85, P=0.0003). In addition, we found that telomere length was inversely correlated with age (r=-0.38, P=0.008). DATA INTERPRETATION: These findings suggest that indicators of cellular senescence, earlier observed in vitro, are also expressed in the human vascular endothelium in vivo. Aneuploidy and telomere attrition might thus play a role in the aging of the human vasculature.

Prepubertal changes in immunoreactive inhibin concentration in blood serum and testicular tissue in Holstein bull calves

Age-related changes in immunoreactive inhibin (ir-inhibin) levels and the relationship among ir-inhibin, gonadotropins and testosterone were examined in 53 Holstein bull calves from neonates to 8.6 months old. Serum levels of ir-inhibin, luteinizing hormone (LH), follicle stimulating hormone (FSH) and testosterone, as well as ir-inhibin levels in testicular extracts, and testicular sizes were measured. All hormones were measured by specific radioimmunoassays. The concentrations of ir-inhibin in serum and testicular tissue were high in neonatal calves and tended to decrease with age. In contrast, serum concentrations of gonadotropins did not show any age-related changes within the experimental period. Serum testosterone levels and testicular sizes (length, width and weight) were positively correlated with age. Furthermore, a positive immunostaining to antiserum for the inhibin alpha-subunit was immunocytochemically observed only in Sertoli cells of the seminiferous tubules from neonates to calves less than 6 months old. These results indicate that the immature bovine testis produces and secretes high levels of ir-inhibin and that the Sertoli cells are a major source of ir-inhibin in prepubertal bull calves.

Estradiol-17beta is produced in bovine corpus luteum

The aim of this study was to investigate the expression of cytochrome P450 aromatase (aromatase) mRNA, its activity, and estradiol-17beta (estradiol) secretion in bovine corpus luteum (CL) during the estrous cycle. Expression of aromatase mRNA was examined in CL at the early, mid, late, and regressed luteal stages by using a reverse transcription-polymerase chain reaction. Aromatase mRNA was detected in all luteal stages examined, although aromatase expression was significantly lower during the early and regressed luteal phases compared to the mid and late luteal phases. Moreover, cultured midluteal cells clearly converted exogenous [(3)H]androstenedione into estradiol, and an aromatase inhibitor significantly inhibited this conversion. To characterize the local release of estradiol within the CL during the estrous cycle, an in vitro microdialysis system (MDS) of CL was conducted. Estradiol in MDS perfusate was confirmed by a reverse-phase high-performance liquid chromatography in combination with enzyme immunoassays. Basal release of estradiol from microdialyzed CL did not change during the estrous cycle. Additionally, when freshly prepared midluteal cells were exposed to estradiol (10(-14) to 10(-9) M), estradiol stimulated prostaglandin (PG) F(2alpha) secretion (P < 0.05), although it did not affect progesterone and oxytocin secretion. The overall results indicate that estradiol is produced locally in bovine CL throughout the estrous cycle, and they suggest that estradiol plays a role in regulating PGF(2alpha) production in CL as an autocrine/paracrine factor.

Expression and action of hepatocyte growth factor in bovine endometrial stromal and epithelial cells in vitro

Hepatocyte growth factor (HGF) is a pleiotropic growth factor that acts on various epithelial cells. The objectives of this study were to determine whether HGF altered the proliferation and prostaglandin (PG) secretion of bovine endometrial stromal and epithelial cells in vitro. We also observed HGF and HGF receptor (c-met) mRNA expression in cultured bovine endometrial stromal and epithelial cells by RT-PCR. Stromal and epithelial cells obtained from cows in early stage of the estrous cycle (days 2-5) were cultured in DMEM/Ham's F-12 supplemented with 10% calf serum. The cells were exposed to HGF (0-10 ng/ml) for 2, 4, or 6 days. HGF significantly increased the total DNA in epithelial (P < 0.05), but not stromal cells. In another experiment, when the cells reached confluence, the culture medium was replaced with fresh medium with 0.1% BSA containing HGF 0-100 ng/ml and the cells were cultured for 24 hr. The HGF stimulated PGF2alpha secretion in epithelial, but not stromal cells. RT-PCR revealed that mRNA of HGF is expressed only in stromal cells, and that c-met mRNA is expressed in both stromal and epithelial cells. These results suggest that HGF plays roles in the proliferation and the regulation of secretory function of bovine endometrial epithelial cells in a paracrine fashion.

Serum progesterone and estradiol-17beta concentrations, and lapaloscopic observations of the ovary in the cheetah (Acinonyxjubatus) with pregnant mare serum gonadotropin and human chorionic gonadotropin treatments

In 3 adult female cheetahs, induced-superovulation treatment was conducted, by means of 200 IU of pregnant mare serum gonadotropin (PMSG) and 100 IU of human chorionic gonadotropin (hCG) 80 hr after PMSG. The administration of PMSG created a sharp increase in the estradiol-17beta concentration, resulting in 232 pg/ml 8 hr later in one specimen out of three. The hCG administration showed an increase in the progesterone concentration of 2.29 ng/ml 46 hr later. In addition, after direct observation of the ovary surface by laparoscopy, 5 follicles in the right ovary over 2 mm in diameter, and 7 corpora lutea (5 in the right ovary and 2 in the left) were found. It is assumed that ovulation can be induced with hCG after 80 hr on PMSG during a cheetah's diestrus or proestrus.

Enamel matrix derivative (EMDOGAIN) rapidly stimulates phosphorylation of the MAP kinase family and nuclear accumulation of smad2 in both oral epithelial and fibroblastic human cells

In our previous study, we demonstrated that porcine enamel matrix derivative (EMD) induces p21WAF1/cip1 within 8 hours and subsequently arrests the cell cycle of human oral epithelial cells in G1 phase. In contrast, EMD markedly stimulates the proliferation of gingival fibroblasts without inducing p21WAF1/cip1. To investigate the mechanism of how EMD produces these differential effects, we have focused on the initial response of these two cell types to EMD. In epithelial cell cultures, EMD stimulated cytoskeletal actin polymerization within 30 min and promoted cell adhesion in our experimental system. EMD failed to stimulate either intracellular Ca2+ mobilization or cAMP production in either cell type. In both epithelial and fibroblastic cells, EMD (25-100 microgram/ml) rapidly produced dose-dependent phosphorylation of the mitogen-activated protein kinase (MAPK) family: extracellular signal response kinase (ERK), p38-MAPK (p38-K), and c-Jun-terminal kinase/stress-activated protein kinase (JNK). However, neither inhibitors of MEK (ERK kinase) nor p38-K could block EMD's anti-proliferative action on epithelial cells. On the other hand, EMD rapidly stimulated translocation of smad2 into the nucleus in both cell types. Spurred by this finding, we assayed for TGF-beta1, a ligand for one receptor associated with smad2 activation, and detected significant levels in EMD preparations. The sum of these pharmacological findings indicates that EMD contains at least one bioactive factor, which is most probably TGF-beta1 (or TGF-beta-like substances). In conjunction with the similarities in the differential growth-modulating actions between EMD and what is known for TGF-beta, we suggest that TGF-beta might act as the principal growth regulating agent of oral fibroblastic and epithelial cell types in EMD despite being present in only low levels.

Actinobacillus actinomycetemcomitans possesses an antigen binding to anti-human IL-10 antibody

It is well known that the cell components of periodontopathic bacteria are able to induce several cytokines and possibly to affect the cytokine network. In order to determine the presence of the periodontopathic Actinobacillus actinomycetemcomitans components recognized by antibodies against cytokine molecules, ELISA reactivities of sonic extracts from the bacterial cells were determined by use of ELISA kits specific for human interleukin (IL)-1beta, IL-4, IL-5, IL-6, IL-10, tumor necrosis factor-alpha, and interferon-gamma. The ELISA analysis demonstrated that the sonic extracts from eight strains of A. actinomycetemcomitans bound with anti-human IL-10 monoclonal antibody. Western blotting analysis revealed that the molecular mass of the antigen was approximately 65 kDa. IL-10 is produced by type 2 helper T cells and mainly down-regulates the type 1 helper T cell response. The present study suggests that the 65-kDa antigen of A. actinomycetemcomitans may affect the host defense function through binding to IL-10 receptor as an agonist or an antagonist for IL-10.