Indocyanine green lymphography in the congenital chylothorax and chylous ascites

BACKGROUND

The prognosis of congenital chylothorax and ascites ranges from spontaneous resolution to death, but no established examination exists to predict the prognosis. We aimed to develop a clinically useful method to evaluate lymphatic abnormalities using indocyanine green (ICG) lymphography in infants with congenital chylothorax and ascites.

METHODS

We retrospectively evaluated infants with congenital chylothorax and chylous ascites who underwent ICG lymphography in our hospital between 2012 and 2022. The ICG lymphography findings was evaluated. We defined the dermal backflow in the trunk as the lymphatic flow from the end of the limb back through the lymphatic vessels on the surface of the trunk. The association between the dermal backflow in the trunk and clinical outcomes, as follows, are investigated: the duration of the drainage period, the duration of endotracheal intubation, and the length of hospital stay.

RESULTS

Twenty infants had a dermal backflow in the trunk, and ten did not. Clinical outcomes in infants with and without dermal backflow in the trunk were as follows (median): the duration of the drainage period (20 vs. 0 days, p = 0.001), the duration of endotracheal intubation (12 vs. 2 days, p = 0.04), and the length of hospital stay (62 vs. 41 days, p = 0.04), respectively. In multivariate linear regression analysis adjusted for gestational age, the duration of the drainage period was correlated with the dermal backflow in the trunk [exp(B) = 2.62; p = 0.003].

CONCLUSIONS

The dermal backflow in the trunk in ICG lymphography was useful in predicting the clinical course of congenital chylothorax and ascites.

Reopening of ductus arteriosus in idiopathic premature constriction or closure of ductus arteriosus: A case series

BACKGROUND

There is no consensus on managing pregnancy when the fetus is diagnosed with idiopathic premature constriction or closure of the ductus arteriosus (PCDA). Knowing whether the ductus reopens is valuable information for managing idiopathic PCDA. We conducted a case-series study to investigate the natural perinatal course of idiopathic PCDA and examined factors associated with ductal reopening.

METHODS

We retrospectively collected information about the perinatal course and echocardiographic findings at our institution, which, on principle, does not determine delivery timing based on fetal echocardiographic results. We also examined perinatal factors related to the reopening of the ductus arteriosus.

RESULTS

Thirteen cases of idiopathic PCDA were included in the analysis. The ductus reopened in 38% of cases. Among cases diagnosed in <  37 weeks of gestation, 71% reopened, which was confirmed seven days after diagnosis (interquartile range 4-7). Diagnosis earlier in gestation was associated with ductal reopening (p = 0.006). Two cases (15%) developed persistent pulmonary hypertension. No fetal hydrops or death occurred.

CONCLUSIONS

The ductus is likely to reopen when prenatally diagnosed before 37 weeks gestation. There were no complications due to our pregnancy management policy. In idiopathic PCDA, especially if the prenatal diagnosis is made before 37 weeks of gestational age, continuing the pregnancy with careful monitoring of the fetus's well-being is recommended.

Difference between "Physical Fitness Age" Based on Physical Function and Chronological Age Is Associated with Obesity, Hyperglycemia, Depressive Symptoms, and Low Serum Albumin

OBJECTIVES

This study aimed to (1) develop the physical fitness age, which is the biological age based on physical function, (2) evaluate the validity of the physical fitness age for the assessment of sarcopenia, and (3) examine the factors associated with the difference between physical fitness age and chronological age.

DESIGN

Cross-sectional study.

SETTING AND PARTICIPANTS

Community-dwelling older adults and outpatients.

MEASUREMENTS

A formula for calculating the physical fitness age was created based on the usual walking speed, handgrip strength, one-leg standing time, and chronological age of 4,076 older adults from the pooled data of community-dwelling and outpatients using the principal component analysis. For the validation of the physical fitness age, we also used pooled data from community-dwelling older adults (n = 1929) and outpatients (n = 473). Sarcopenia was diagnosed according to the Asian Working Group for Sarcopenia 2019 consensus. The association of D-age (the difference between physical and chronological ages) with cardiovascular risk factors, renal function, and cardiac function was examined.

RESULTS

The receiver operating characteristic analysis, with sarcopenia as the outcome, showed that the area under the curve (AUC) of physical fitness age was greater than that of chronological age (AUC 0.87 and 0.77, respectively, p < 0.001). Binomial logistic regression analysis revealed that the D-age was significantly associated with sarcopenia after adjustment for covariates (odds ratio 1.22, 95% confidence interval 1.19-1.26; p <0.001). In multivariate linear regression analysis with D-age as the dependent variable, D-age was independently associated with a history of diabetes mellitus (or hemoglobin A1c as a continuous variable), obesity, depression, and low serum albumin level. D-age was also correlated with estimated glomerular filtration rate derived from serum cystatin C, brain natriuretic peptide, and ankle-brachial index, reflecting some organ function and arteriosclerosis.

CONCLUSIONS

Compared to chronological age, physical fitness age calculated from handgrip strength, one-leg standing time, and usual walking speed was a better scale for sarcopenia. D-age, which could be a simple indicator of physical function, was associated with modifiable factors, such as poor glycemic control, obesity, depressive symptoms, and malnutrition.

Synergistic anti-AML effects of the LSD1 inhibitor T-3775440 and the NEDD8-activating enzyme inhibitor pevonedistat via transdifferentiation and DNA rereplication

Lysine-specific demethylase 1A (LSD1, KDM1A) specifically demethylates di- and monomethylated histones H3K4 and K9, resulting in context-dependent transcriptional repression or activation. We previously identified an irreversible LSD1 inhibitor T-3775440, which exerts antileukemic activities in a subset of acute myeloid leukemia (AML) cell lines by inducing cell transdifferentiation. The NEDD8-activating enzyme inhibitor pevonedistat (MLN4924, TAK-924) is an investigational drug with antiproliferative activities in AML, and is also reported to induce cell differentiation. We therefore tested the combination of these two agents in AML models. The combination treatment resulted in synergistic growth inhibition of AML cells, accompanied by enhanced transdifferentiation of an erythroid leukemia lineage into granulomonocytic-like lineage cells. In addition, pevonedistat-induced rereplication stress during the S phase was greatly augmented by concomitant treatment with T-3775440, as reflected by the increased induction of apoptosis. We further demonstrated that the combination treatment was markedly effective in subcutaneous tumor xenograft models as well as in a disseminated model of AML, leading to tumor eradication or prolonged survival in T-3775440/pevonedistat cotreated mice. Our findings indicate the therapeutic potential of the combination of LSD1 inhibitors and pevonedistat for the treatment of AML.

Extensive use of vasodilator agents and functional echocardiography to monitor extremely-low-birth-weight infants in Japan

National surveys were conducted in Japan to assess the current practices for circulatory management of extremely-low-birth-weight infants (ELBWIs) in acute phases. Approximately 80 and 100 institutions were surveyed in 2006 and 2011, respectively. Echocardiography was identified as an important diagnostic tool at 95% of the surveyed institutions. Furthermore, 74% of the institutions survey in 2011 used vasodilator agents. In 2011, the mean velocity of circumferential fiber shortening (mVcfc) and left ventricular end-systolic wall stress (ESWS) were used by 60% of the surveyed institutions to evaluate the relationship between afterload of the left ventricle and left ventricular contractility. Overall, the data collected from these national surveys clarified the current practices for circulatory management of ELBWIs in Japan, particularly the use of echocardiography and cardiovascular agents, including catecholamines and vasodilators.

Characterization of Dental Epithelial Progenitor Cells Derived from Cervical-loop Epithelium in a Rat Lower Incisor

Dental epithelial progenitor cells differentiate into various cell types during development of tooth germs. To study this mechanism, we produced immortalized dental epithelial progenitor cells derived from the cervical-loop epithelium of a rat lower incisor. The expression patterns of cytokeratin 14, nerve growth factor receptor p75, amelogenin, Notch2, and alkaline phosphatase were examined by immnohistochemistry in both lower and higher cell densities. The patterns of each were compared in the dental epithelium of rat lower incisors. The results demonstrated that these cells could produce ameloblast lineage cells, stratum intermedium cells, stellate reticulum, and outer enamel epithelium. Furthermore, fibroblast growth factor 10 stimulated proliferation of dental progenitor cells and subsequently increased the number of cells expressing alkaline phosphatase. These results suggest that fibroblast growth factor 10 plays a role in coupling mitogenesis of the cervical-loop cells and the production of stratum intermedium cells in rat incisors.

Expression of GAD67 and Dlx5 in the taste buds of mice genetically lacking Mash1

It has been reported that a subset of type III taste cells express glutamate decarboxylase (GAD)67, which is a molecule that synthesizes gamma-aminobutyric acid (GABA), and that Mash1 could be a potential regulator of the development of GABAnergic neurons via Dlx transcription factors in the central nervous system. In this study, we investigated the expression of GAD67 and Dlx in the embryonic taste buds of the soft palate and circumvallate papilla using Mash1 knockout (KO)/GAD67-GFP knock-in mice. In the wild-type animal, a subset of type III taste cells contained GAD67 in the taste buds of the soft palate and the developing circumvallate papilla, whereas GAD67-expressing taste bud cells were missing from Mash1 KO mice. A subset of type III cells expressed mRNA for Dlx5 in the wild-type animals, whereas Dlx5-expressing cells were not evident in the apical part of the circumvallate papilla and taste buds in the soft palate of Mash1 KO mice. Our results suggest that Mash1 is required for the expression of GAD67 and Dlx5 in taste bud cells.

Efficacy of music therapy in treatment for the patients with Alzheimer's disease

We report that music therapy is effective in the treatment of Alzheimer's disease. We found that the secretion of 17β-estradiol and testosterone, hormones that are supposed to have preventive effects on Alzheimer's disease, is significantly increased by music therapy. During the sessions, patients with Alzheimer's disease were allowed to listen to music and songs with verbal contact from the therapist. It was found that problematic behaviors such as poriomania (fugue) had decreased. Music therapy has the potential as an alternative treatment for adverse hormone replacement therapy.

Differential expression of the glucose transporters in mouse gustatory papillae

Taste receptors and their downstream signaling molecules are activated by sugars and sweeteners in the gut and participate in the regulation of glucose transport into enterocytes. The glucose transporter families GLUT and SGLT are responsible for the absorption of glucose, GLUT4 and SGLT1 being expressed preferentially in T1R3-positive taste cells. However, the expression patterns of the other glucose transporters in mouse gustatory tissues have not yet been elucidated. Therefore, we have examined the expression patterns of the glucose transporters (GLUT1-4 and SGLT1-3) in mouse gustatory tissues. Reverse transcription/polymerase chain reaction assays have revealed that GLUT1, 3, and 4 and SGLT1 mRNAs are expressed in the circumvallate papillae. Immunohistochemical analysis has shown that SGLT1 is expressed in a subset of the epithelial cells: from the basal cell layer to the prickle cell layer and in intragemmal and extragemmal epithelium cells in the circumvallate, foliate, and fungiform papillae. GLUT1, GLUT3, and GLUT4 are expressed in the prickle cell layers and/or basal cell layers in these papillae. Moreover, GLUT1, but not GLUT3 or GLUT4, is expressed in a subset of intragemmal and extragemmal epithelium cells in these papillae. Double-labeling experiments have demonstrated that GLUT1-positive taste bud cells coexpress gustducin and inositol 1,4,5-triphosphate receptor type III. These results suggest that SGLT1 and GLUT1 play a role in glucose-sensing and/or transport in mouse taste buds.

Physical fitness and 6.5-year mortality in an 85-year-old community-dwelling population

Although poor physical fitness is known to be associated with increased mortality in adult and elderly populations, this association is not conclusive in very elderly. The purpose of the present study was to evaluate the association for a very old community-dwelling population. The participants (90 males, 117 females) were 85-year-old individuals residing in Fukuoka, Japan. Baseline examinations including muscle strength of the handgrip and leg extension, one-leg standing, leg stepping rate, and walking were performed in 2003 and these subjects were followed for 6.5 years. During the follow-up period, 81 individuals (49 males and 32 females) died. Handgrip strength and leg extension strength at age 85 were stronger in surviving men than in non-survivors. Total mortality adjusted for both gender and serum level of total cholesterol fell 5-6% with a 1-kg increase in the handgrip strength of a single hand or both hands. Total mortality also decreased 2% with a 1 kg increase in the leg extension strength of both legs. With adjustment for gender and total cholesterol, mortality fell by 57% in participants of the walking test and fell by 45% in participants of the stepping-rate test compared to mortality in nonparticipants. No association was found between mortality and participation in the handgrip strength test, leg extension strength test, or one-leg standing time test. In conclusion, not only poor muscle strength in handgrip or leg extension, but also nonparticipation in walking test or leg-stepping test were independent predictors of total mortality in a very elderly population.

Mash1 is required for the differentiation of AADC-positive type III cells in mouse taste buds

Mash1 is expressed in subsets of neuronal precursors in both the central nervous system and the peripheral nervous system. However, involvement of Mash1 in taste cell differentiation has not previously been demonstrated. In this study, we investigated the role of Mash1 in regulating taste bud differentiation using Mash1 KO mice to begin to understand the mechanisms that regulate taste bud cell differentiation. We found that aromatic L-amino acid decarboxylase (AADC) cells were not evident in either the circumvallate papilla epithelia or in taste buds in the soft palates of Mash1 KO mice. However gustducin was expressed in taste buds in the soft palates of Mash1 KO mice. These results suggest that Mash1 plays an important role in regulating the expression of AADC in type III cells in taste buds, which supports the hypothesis that different taste bud cell types have progenitor cells that are specific to each cell type.

Plasminogen/plasmin modulates bone metabolism by regulating the osteoblast and osteoclast function

The contribution of plasminogen (Plg)/plasmin, which have claimed to be the main fibrinolytic regulators in the bone metabolism, remains unclear. This study evaluated how the absence of Plg affects the function of osteoblast (OB) and osteoclast (OC). There was a larger population of pre-OCs in bone marrow-derived cells from the Plg(-/-) mice than the population of that from the WT mice. In addition, the absence of Plg suppressed the expression of osteoprotegerin in OBs. Moreover, an exogenous plasmin clearly induced the osteoprotegerin expression in Plg(-/-) OBs. The osteoclastogenesis of RAW264.7 mouse monocyte/macrophage lineage cells in co-culture with OBs from the Plg(-/-) mice was significantly accelerated in comparison with that in co-culture with OBs from the WT mice. Intriguingly, the accelerated OC differentiation of RAW264.7 cells co-cultured with Plg(-/-) OBs was clearly suppressed by the treatment of an exogenous plasmin. Consequently, Plg(-/-) mice display decreased bone mineral density. These findings could eventually lead to the development of new clinical therapies for bone disease caused by a disorder of the fibrinolytic system.

A study of the efficacy of ultrasonic waves in removing biofilms

OBJECTIVE

The removal of adherent biofilms was assessed using ultrasonic waves in a non-contact mode.

MATERIALS AND METHODS

In in vitro experiments, Streptococcus mutans (S. mutans) biofilms were exposed to ultrasonic waves at various frequencies (280 kHz, 1 MHz, or 2 MHz), duty ratios (0-90%), and exposure times (1-3 minutes), and the optimal conditions for biofilm removal were identified. Furthermore, the effect of adding a contrast medium, such as micro bubbles (Sonazoid), was examined. The spatial distribution and architecture of S. mutans biofilms before and after ultrasonic wave exposure were examined via scanning electron microscopy. The biofilm removal effect was also examined in in vivo experiments, using a custom-made oral cleaning device.

RESULTS

When a 280 kHz probe was used, the biofilm-removing effect increased significantly compared to 1 and 2 MHz probes; more than 80% of the adherent biofilm was removed with a duty cycle of 50-90% and a 3 minutes exposure time. The maximum biofilm-removing effect was observed with a duty cycle of 80%. Furthermore, the addition of micro bubbles enhanced this biofilm-removing effect. In in vivo experiments, moderate biofilm removal was observed when a 280 kHz probe was used for 5 minutes.

CONCLUSIONS

This study demonstrated that ultrasonic wave exposure in a non-contact mode effectively removed adherent biofilms composed of S. mutans in vitro.

Possible association of atrophic gastritis and arterial stiffness in healthy middle-aged Japanese

AIM

Helicobacter pylori (HP) has been implicated as a risk factor for cardiovascular and atherosclerotic diseases. Arterial stiffness determined by pulse wave velocity (PWV) or the cardio-ankle vascular index (CAVI) has been shown to be higher in HP-positive subjects than in HP-negative subjects; however, this result has been observed only in young subjects. The aim of the study was to investigate the possible correlation between HP infection and PWV or CAVI in middle-aged subjects.

METHODS

We measured brachial-ankle PWV (baPWV), CAVI, metabolism markers, pepsinogens (PGs) and IgG antibody to HP in 343 individuals aged either 60 or 65 year old. Atrophic gastritis (AG) was diagnosed based on the values of PGs.

RESULTS

baPWV and CAVI were significantly higher in the AG-positive group than in the AG-negative group even after adjusting for possible confounding factors (baPWVc; 16.63+/-3.50 vs. 15.59+/-3.47 p=0.010, CAVIc; 8.59+/-1.20 vs. 8.27+/-1.19 p=0.022). baPWV and CAVI values tended to be higher in the HP-positive group than in the HP-negative group. High-density lipoprotein (HDL) cholesterol level and the adiponectin level were lower in the AG-positive group than in the AG-negative group.

CONCLUSION

There may be an association between atrophic gastritis and atherosclerosis in middle-aged subjects.

Identification of the genes associated with a virulent strain of Porphyromonas gingivalis using the subtractive hybridization technique

BACKGROUND/AIMS

Porphyromonas gingivalis, a major etiological organism implicated in periodontal disease, can be classified into virulent and avirulent strains. Our aim was to identify a gene for the virulence of P. gingivalis.

METHODS

The subtractive hybridization technique was employed to identify the genes specific to P. gingivalis W83, a virulent strain. In this study, P. gingivalis W83 was used as the tester strain, and P. gingivalis ATCC 33277 was the driver strain. The prevalence of W83-specific genes was determined by Southern blot analysis of several P. gingivalis strains.

RESULTS

We obtained 575 colonies using the subtractive hybridization technique. From among these, 26 DNA fragments were subjected to a homology search using the BLAST program. Compared with strain ATCC 33277, strain W83 contained 12 unique clones. The specificities of the isolated DNA fragments were analyzed among four P. gingivalis strains by Southern blot analysis. Five genes showed specificity for strain W83 compared with strain ATCC 33277. All five genes were also identified in strain W50.

CONCLUSIONS

The subtractive hybridization technique was effective in screening the two strains for specific DNA sequences, some of which might be responsible for determining virulence. The results suggested that several genes specific to strain W83 were associated with its virulence. Further analysis of these DNA fragments will provide important information on the pathogenesis of virulent P. gingivalis strains.

Protein tyrosine kinases belonging to the src family

There are nine non-receptor-type protein tyrosine kinases that show a high level of similarity in their primary structures and in the structures of their functional domains. Together, they are called the src family. They seem to have common sites specific for oncogenic activation. Recent findings suggest that the kinases are closely associated with cell surface molecules and that they mediate extracellular signals through the activation of their tyrosine kinase activity. They appear to act more on the differentiated phenotype than in haemopoietic cell proliferation. Possible functions of the products of the lck, fyn, lyn and fgr genes in lymphocytes and monocytes are discussed.

Expression of ATP-gated P2X3 receptors in rat gustatory papillae and taste buds

It has recently become evident that ATP and other extracellular nucleotides could play an important role in signal transductions. ATP mediates excitatory signaling by means of P2X receptors. P2X3, one of its subtypes, a membrane ligand-gated ion channel, is strongly expressed in peripheral sensory neurons. The aim of the present study was to examine the distribution of nerve fibers expressing P2X3 receptors in taste buds in the gustatory papillae and soft palate of rats by immunohistochemistry. We found that the fluorescence ATP marker quinacrine stained subsets of taste bud cells. Numerous nerve fibers innervating taste buds were intensely immunostained with the P2X3 receptor antibody. These nerve fibers ascended among intragemmal cells and terminated just below the taste pores. In order to examine whether P2X3 receptors are involved in signal modulation within taste buds, we used fluorescent double stainings to analyze the distribution of P2X3 receptors and their relationship to alpha-gustducin immunopositive taste receptor cells. Many varicose nerve fibers expressing P2X3 receptor-immunoreactivities were entangled with alpha-gustducin-immunopositive taste receptor cells and ended closely below the taste pores. In fungiform papillae, nerve fibers expressing both P2X3 receptors and PGP 9.5 were observed. In contrast, only PGP 9.5 immunoreactive nerve fibers were recognized in filiform papillae. These results suggest that P2X3 receptors might be involved in taste transmission pathways within taste buds. ATP may act as a neurotransmitter, co-transmitter, or neuromodulator at P2X3 receptors to generate activating gustatory nerve fibers.

Expression of group II metabotropic glutamate receptors in rat gustatory papillae

Glutamate is one candidate for the neurotransmitters and/or neuromodulators involved in taste signaling in taste buds. Group II metabotropic glutamate receptors (mGluRs: mGluR2 and mGluR3) are known to function as presynaptic receptors that regulate the release of glutamate and/or other neurotransmitters in the central nervous system. Group II mGluRs are negatively linked to adenylyl cyclase through Galphai subunits and thereby reduce the turnover of cAMP. In rat taste tissues, a subset of adenylyl-cyclase-8-expressing taste cells coexpress the Galphai subunits gustducin and Galphai2. However, the expression patterns of group II mGluRs in rat taste tissues have not yet been elucidated. We have therefore examined the expression patterns of mGluR2, mGluR3, and gustducin in rat gustatory tissues. Reverse transcription/polymerase chain reaction assays have revealed that mGluR2 and mGluR3 mRNAs are expressed in the circumvallate papillae. In situ hybridization analyses have detected positive signals for mGluR2 and mGluR3 mRNAs only in the circumvallate taste buds. Among the fungiform, foliate, and circumvallate papillae, an antibody against mGluR2/3 labels a subset of taste bud cells and nerve fibers immediately beneath the taste lingual epithelium. Double-labeling experiments have demonstrated that mGluR2/3-positive cells coexpress gustducin. These results indicate that mGluR2 and mGluR3 are coupled to Galphai subunits and play roles in glutamate-mediated signaling in taste transductions.

Immunohistochemical localization of aromatic l-amino acid decarboxylase in mouse taste buds and developing taste papillae

Aromatic L-amino acid decarboxylase (AADC) catalyses the decarboxylation of all aromatic L-amino acids. In mammals, AADC is expressed in many tissues besides the nervous system, and is associated with additional regulatory roles of dopamine and serotonin in a wide range of tissues. We examined the expression of AADC by using reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry. RT-PCR analysis showed that mRNA of AADC was detected in the taste bud-containing epithelium of the circumvallate papilla of mice. By immunohistochemical analyses, AADC was detected in a subset of taste bud cells of fungiform, foliate, and circumvallate papillae. Double-label studies showed that AADC colocalized with serotonin, NCAM, PLCbeta2, and PGP9.5. On the other hand, AADC never colocalized with alpha-gustducin. Our results of double staining with AADC and taste cell markers indicate that only the type III cells could convert 5-hydroxytryptophan (5-HTP) to serotonin within taste buds. Taken together with previous studies, the properties of the type III cell of taste buds exactly fit into the APUD (amine and amine precursor uptake and decarboxylation) cell scheme. Furthermore, in the developing circumvallate papilla, AADC are first detected in a small number of papillary epithelial cells at E14.5. By E18.5, AADC-positive epithelial cells also express PGP9.5, which is one of marker of taste cells, and these cells have been contacted by developing nerve fibers. These results suggest that AADC expression begins at early stages of taste bud cell differentiation, and biogenic amines may act on taste bud differentiation of tongue epithelial cells, and further may regulate innervation of taste bud progenitor cells.

The bHLH transcription factors, Hes6 and Mash1, are expressed in distinct subsets of cells within adult mouse taste buds

Taste buds are multicellular receptor organs embedded in the lingual epithelium of vertebrates. Taste cells within these buds are modified epithelial cells as they lack axons and turnover rapidly throughout life, yet have neuronal properties enabling them to transduce taste stimuli and transmit this information to the nervous system. Taste cells are heterogeneous, comprising types I, II, III and basal cells, and are continually replaced during adult life, raising the question of how these different cells are generated. The molecular mechanisms governing taste cell differentiation are unknown, but the Notch signaling system has been implicated in this process based upon recent gene expression data. Here we investigate the expression in mature taste buds of Notch related transcription factors, Hes6 and Mash1, which are among the first genes expressed in embryonic taste buds. We further compare these patterns with those of immunocytochemical markers of discrete taste cell types. We find that Hes6 is expressed in a subset of basally located, possibly progenitor cells, yet is rarely coexpressed with taste cell markers. In contrast, Mash1 is detected in some basal cells and in the majority of differentiated type III taste cells, but never in type II cells. These data suggest a role for Notch signaling in taste cell differentiation in adult taste buds.

Expression of synaptotagmin 1 in the taste buds of rat gustatory papillae

Synapses between taste receptor cells and primary sensory afferent fibers transmit the output signal from taste buds to the central nervous system. The synaptic vesicle cycle at the synapses involves vesicle docking, priming, fusion, endocytosis, and recycling. Many kinds of synaptic vesicle proteins participate in synaptic vesicle cycles. One of these, synaptotagmin 1, binds Ca(2+) phospholipids with high affinity and plays a role in Ca(2+) regulated neurotransmitter release in the central and peripheral nervous systems. However, the expression patterns of synaptotagmin 1 in rat taste tissues have not been determined. We therefore examined the expression patterns of synaptotagmin 1 and several cell specific markers of type II and III cells in rat taste buds. RT-PCR assay showed that synaptotagmin 1 mRNA was expressed in circumvallate papillae. In fungiform, foliate, and circumvallate papillae, the antibody against synaptotagmin 1 yielded the labeling of a subset of taste bud cells and intra- and subgemmal nerve processes. Double labeled experiments showed that synaptotagmin 1 positive cells co-expressed type III cell markers, PGP 9.5, and NCAM. Intragemmal nerve processes positive for synaptotagmin 1 co-expressed PGP 9.5. Conversely, all synaptotagmin 1 expressing cells did not co-expressed type II cell markers, PLCbeta2, or gustducin. These results show that synaptotagmin 1 may play some regulatory roles in vesicle membrane fusion events with the plasma membrane at the synapses of type III cells in rat taste buds.

Expression of galanin and the galanin receptor in rat taste buds

Galanin, a 29-amino-acid neuropeptide, was initially isolated from porcine intestine. It has a wide spread distribution in the central nervous system and is also present in the primary sensory neuron. Galanin has been suggested to be involved in numerous neuronal and endocrine functions as a neurotransmitter and neuromodulator. We examined the expression of galanin and galanin receptors by using a reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemistry, and in situ hybridization. RT-PCR analysis showed that mRNA of galanin and GalR2 were detected in the taste bud-containing epithelium of the circumvallate papilla of rats. Immunohistochemical analyses detected galanin was detected in a subset of taste bud cells of the circumvallate papillae. Double-label studies showed that galanin colocalized with alpha-gustducin, NCAM, and PLCbeta2. Our results of double staining with galanin and taste cell markers indicate that galanin-expressing taste cells are type II and type III cells. Taken together with previous studies, these findings show that galanin may function as a taste bud neurotransmitter. Furthermore, GalR2 mRNA was expressed in some taste bud cells. This suggests that, galanin release may not only excite the peripheral afferent nerve fiber but also may act on neighboring taste receptor cells via the activation of GalR2.

Identification and characterization of an autolysin-encoding gene of Streptococcus mutans

We identified a gene (atlA) encoding autolytic activity from Streptococcus mutans Xc. The AtlA protein predicted to be encoded by atlA is composed of 979 amino acids with a molecular weight of 107,279 and has a conserved beta-1,4-N-acetylmuramidase (lysozyme) domain in the C-terminal portion. Sodium dodecyl sulfate extracts of strain Xc showed two major bacteriolytic bands with molecular masses of 107 and 79 kDa, both of which were absent from a mutant with inactivated atlA. Western blot analysis revealed that the 79-kDa band was derived from the 107-kDa peptide by cleavage of its N-terminal portion. The inactivation of atlA resulted in a marked decrease in autolysis and the formation of very long chains of cells compared to the case for the parent strain. Although both the parent and mutant strains formed biofilms in the presence of sucrose, the biofilms formed by the mutant had a sponge-like architecture with large gaps and contained 30% less biomass than those formed by the parent strain. Furthermore, strain Xc formed glucose-dependent, loose biofilms in the absence of sucrose, but the mutant lost this ability. These results suggest that AtlA may play an important role in biofilm formation by S. mutans. The antibody produced against the C-terminal peptide containing the beta-1,4-N-acetylmuramidase domain drastically inhibited the autolytic activity of strain Xc. This inhibition was specific among the oral streptococci to S. mutans. These results indicate that the catalytic domain of AtlA is located at the C terminus, suggesting that further characterization of this domain may provide a means to control cariogenic dental plaque formation.

In vitro differentiation of dental epithelial progenitor cells through epithelial-mesenchymal interactions

In developing teeth, dental epithelial progenitor cells differentiate through sequential and reciprocal interactions with neural-crest-derived mesenchyme. However, the molecular mechanisms involved in cell differentiation are not well understood. Continuously growing teeth are useful in the study of differentiation of dental progenitor cells. In rat lower incisors, ameloblasts originate from the dental epithelial adult stem cell compartment referred to as the 'apical bud'. To elucidate the mechanism of ameloblast differentiation, we designed a primary culture system and confirmed the differentiation of dental epithelial cells through interaction with mesenchymal cells. Cytokeratin was used as a marker for epithelial cells, nerve growth factor receptor p75 for inner enamel epithelial (IEE) cells, and ameloblastin for ameloblasts. The apical bud cells could only differentiate into IEE cells and, within 10 days, into ameloblasts expressing ameloblastin in the presence of dental papilla cells. Interestingly, the IEE cells could proliferate transiently and differentiate into ameloblasts in the presence or absence of dental papilla cells. These results suggest that apical bud cells can enter the ameloblast cell lineage through interaction with mesenchymal cells. IEE cells, on the other hand, are already committed to differentiate into ameloblasts. This culture system is useful in future studies of ameloblast differentiation.

Expression of P2Y 1 receptors in rat taste buds

Extracellular nucleotides such as ATP are the signaling molecules which bind to membrane receptors (P2X ligand-gated ion channels and G-protein-coupled P2Y families). In the gustatory system, it is known that P2X receptors are expressed exclusively in nerve fibers innervating the taste buds. Also, P2Y receptors are suggested to play some important roles in taste signal transductions on the basis of the physiological studies. In the present study, we examined the expression patterns of P2Y1 receptor subtype by using reverse transcript polymerase chain reaction (RT-PCR), in situ hybridization, and immunohistochemistry. RT-PCR analyses showed that P2Y1 receptor mRNAs appeared in circumvallate papillae. P2Y1 receptor mRNA was detected in a subset of taste bud cells by in situ hybridization. By immunohistochemical analyses, P2Y1 receptor was detected in a subset of taste bud cells of fungiform, foliate, and circumvallate papillae. We showed that ATP induced a biphasic intracellular Ca2+ increase in taste cells by a Ca2+ imaging method. Furthermore, we showed by double-immunolabeling methods that P2Y1-expressing cells coexpressed both IP3R3 and SNAP-25. These results suggest that ATP may activate P2Y receptors resulting in Ca2+ release from internal stores via IP3R3. Since many SNAP-25-immunoreactive taste bud cells coexpressed P2Y1 immunoreactivity, it is suggested that P2Y1-expressing cells may possess synapses with afferent nerve fibers. The results of the present study suggest that P2Y1 receptor may play some roles in ATP-mediated signal transductions between taste bud cells and afferent taste fibers.

Expression of metabotropic glutamate receptor group I in rat gustatory papillae

Taste-metabotropic glutamate receptor 4 (taste-mGluR4) and the heteromers of T1R1 and T1R3 are candidate receptors involved in the sense of umami (monosodium glutamate) taste. Although the expression of group III mGluRs (taste-mGluR4) has been demonstrated in taste tissues, no mention has been made of the expression of group I mGluRs (mGluR1 and mGluR5) in taste tissues. We examined the expression of mGluR1 and mGluR5 in rat gustatory tissues by using reverse transcription-polymerase chain reaction (RT-PCR), in situ hybridization, immunohistochemistry and immunoelectron microscopy. RT-PCR assay showed that mGluR1 alpha and mGluR1 beta mRNAs were expressed in circumvallate papillae, but mGluR5 mRNA was not expressed. The positive signals of mGluR1 mRNA were detected only in circumvallate taste buds by in situ hybridization analysis. In cryosections of fungiform, foliate and circumvallate papillae, the antibody against mGluR1 alpha gave intense labeling on the taste hairs in all taste pores examined. In the developing taste buds, the positive signals of mGluR1alpha in taste hairs gradually increased with the increase in number of taste bud cells. These results show that, in addition to taste-mGluR4 and the heteromer of T1R1 and T1R3, mGluR1 alpha may function as a receptor for glutamate (umami) taste sensation.

Villin is a possible marker of receptor cells in frog taste organs

We investigated lingual taste organs of four frog species mainly by means of fluorescence immunohistochemistry for villin, calbindin, and serotonin. Cells immunoreactive for villin appeared in the taste organs of all the species used. These villin-immunostained cells were basoapically elongated in shape and extended up to the apical surface. They were also immunoreactive for calbindin. On the other hand, serotonin-immunoreactive cells, identified as Merkel-like basal cells, were immunonegative for villin. Considering the present results combined with those of studies by other research groups, the villin-immunostained cells were postulated to function as taste receptors.

Establishment of dental epithelial cell line (HAT-7) and the cell differentiation dependent on Notch signaling pathway

Rat incisors grow continuously throughout life. Producing a variety of dental epithelial cells is performed by stem cells located in the cervical loop of the incisor apex. To study the mechanisms for cell differentiation, we established a dental epithelial cell line (HAT-7) originating from a cervical loop epithelium of a rat incisor. Immunochemical studies showed that HAT-7 produced the cells expressing amelogenin, ameloblastin, or alkaline phosphatase (ALP). To illustrate a role of Notch signaling in the determinant of the cell fate, we examined expression patterns of Notch1 and Jagged1 in HAT-7 density dependently. At lower cell density, Notch1- or Jagged1-expressing cells were not seen. However, when they were fully confluent, cells began to express Notch1 or Jagged1 strongly. Some ALP-positive cells were almost consistent with Notch1-expressing cells but not Jagged1-expressing cells. These results suggested that the determinant of direction of differentiation was associated with Notch signaling pathway.

FGF10 maintains stem cell population during mouse incisor development

Mouse incisors have a cervical loop that gives rise to dental epithelium in the apical region of the tooth germ, in contrast to molars. In a study of formation of the stem-cell compartment, we focused on expression patterns of fibroblast growth factor (Fgf) 10 and Fgf3 in developing mice incisors. At E14, Fgf10 and Fgf3 were coexpressed in the dental papilla. After E16 mesenchymal cells underlying cervical loop expressed Fgf10 but not Fgf3. To illustrate the role of FGF10, we analyzed incisor development of Fgf10-deficient mice. The germs of FGF10-null mice proceeded to cap stage normally. However, at a later stage, the cervical loop was not formed. Functional disorder of FGF10 by a neutralizing anti-FGF10 antibody induced apoptosis in the cervical loop of incisor explants. Recombinant FGF10 rescued the cervical loop from apoptosis. These results show that FGF10 maintains the stem-cell compartment in the developing incisor tooth germ.

Epithelial stem cells in teeth

Many tissues and organs maintain a process known as homeostasis, in which cells are replenished as they die as a result of apoptosis or injury. The continuously growing mouse incisors are an excellent model for studying the molecular mechanisms of cell homeostasis, renewal, and repair. We elucidated these mechanisms in mouse incisors by detecting adult stem cells and analyzing the stem cell lineage by bromodeoxyuridine (BrdU) labeling analysis. The stem cells divide slowly, giving rise to a daughter cell that remains in the cervical loop and a second daughter cell that enters the zone of rapidly dividing inner enamel epithelial cells (transit-amplifying cell population). During subsequent rounds of cell division, the latter cells move toward the incisal end and differentiate into ameloblasts that form the enamel matrix. Recent evidence from gene knockout mice suggests that fibroblast growth factor (Fgf10) plays an important role in the formation and maintenance of stem cells in the development of mouse incisors. The role of dental stem cells in odontogenic tumors is discussed.

FGF10 maintains stem cell compartment in developing mouse incisors

Mouse incisors are regenerative tissues that grow continuously throughout life. The renewal of dental epithelium-producing enamel matrix and/or induction of dentin formation by mesenchymal cells is performed by stem cells that reside in cervical loop of the incisor apex. However, little is known about the mechanisms of stem cell compartment formation. Recently, a mouse incisor was used as a model to show that fibroblast growth factor (FGF) 10 regulates mitogenesis and fate decision of adult stem cells. To further illustrate the role of FGF10 in the formation of the stem cell compartment during tooth organogenesis, we have analyzed incisor development in Fgf10-deficient mice and have examined the effects of neutralizing anti-FGF10 antibody on the developing incisors in organ cultures. The incisor germs of FGF10-null mice proceeded to cap stage normally. However, at a later stage, the cervical loop was not formed. We found that the absence of the cervical loop was due to a divergence in Fgf10 and Fgf3 expression patterns at E16. Furthermore, we estimated the growth of dental epithelium from incisor explants of FGF10-null mice by organ culture. The dental epithelium of FGF10-null mice showed limited growth, although the epithelium of wild-type mice appeared to grow normally. In other experiments, a functional disorder of FGF10, caused by a neutralizing anti-FGF10 antibody, induced apoptosis in the cervical loop of developing mouse incisor cultures. However, recombinant human FGF10 protein rescued the cervical loop from apoptosis. Taken together, these results suggest that FGF10 is a survival factor that maintains the stem cell population in developing incisor germs.

Two receptor theory in innate immune activation: studies on the receptors for bacillus Culmet Guillen-cell wall skeleton

Activation of the innate immune system is a prerequisite for the maturation of dendritic cells (DC) and macrophages (Mphi) followed by clonal expansion of the lymphocytes, targeting cells expressing "non-self' antigens. Microbes usually have a component competent to activate DC/Mphi for antigen presentation. This component has been called adjuvant, but recently renamed "pathogen-associated molecular pattern" (PAMP) or modulin based on its molecular identification. Here, we propose the hypothesis that DC/Mphi express two sorts of receptors for PAMP, whose signaling pathways lead to a sufficient antigen (Ag)-presenting state. In bacterial infection, a Toll-like receptor (TLR) and an uptake receptor participate in DC maturation and Mphi activation. Likewise, with a number of viruses, two of the receptors, with short consensus repeats (SCR), immunoglobulin-like domains or chemokine receptor-like motifs etc. induce functional modulation of DC/Mphi. In immune therapy for cancer, primary activation of the innate system would be essential for tumor Ag-specific T cell augmentation. Cancer cells express tumor-associated Ag but barely co-express PAMP, which situation does not allow for the activation of innate immune responses. Supplementing tumor-associated Ag with PAMP may be an effective therapy for patients with cancer. Here, we discuss the possibility of an innate immune therapy for cancer with reference to bacillus Culmet Guillen cell-wall skeleton (BCG-CWS).

Expression of the metabotropic glutamate receptor, mGluR4a, in the taste hairs of taste buds in rat gustatory papillae

Taste-mGluR4, cloned from taste tissues, is a truncated variant of brain-expressed mGluR4a (brain-mGluR4), and is known to be a candidate for the receptor involved in the umami taste sense. Although the expression patterns of taste- and brain-mGluR4 mRNAs have been demonstrated, no mention has so far been made of the expression of these two mGluR4 proteins in taste tissues. The present study examined the expression of taste-mGluR4 and brain-mGluR4 proteins in rat taste tissues by using a specific antibody for mGluR4a which shared a C-terminus of both taste- and brain-mGluR4, for immunoblot analysis and immunohistochemistry. Immunoblot analysis showed that both brain-mGluR4 and taste-mGluR4 were expressed in the taste tissues. Taste-mGluR4 was not detected in the cerebellum. The immunoreactive band for brain-mGluR4 protein was much stronger than that for taste-mGluR4 protein. In the cryosections of fungiform, foliate and circumvallate papillae, the antibody against taste-mGluR4 exhibited intense labeling of the taste pores and taste hairs in all the taste buds of gustatory papillae examined; the immunoreaction to the antibody against brain-mGluR4 was more intense at the same sites of the taste buds. The portions of the taste bud cells below the taste pore and surrounding keratinocytes did not show any immunoreactivities. The results of the present study strongly suggest that, in addition to taste-mGluR4, brain-mGluR4 may function even more importantly than the former as a receptor for glutamate, i.e. the umami taste sensation.

Molecular cloning and functional characterization of chicken toll-like receptors. A single chicken toll covers multiple molecular patterns

Toll-like receptors (TLR) in the innate immune system have not been identified in non-mammalian vertebrates. Two types of TLR were cloned from a chicken bursa cDNA library using degenerate primers based on the consensus sequences of mouse and Drosophila Toll and designated as chicken TLR (chTLR) type 1 and type 2. Of the nine human TLRs reported to date, these chTLRs showed the highest homology to human TLR2. The extracellular regions of type 1 and type 2 contained a distinct approximately 200-amino acid stretch and were 45.3 and 46.3% homologous to that of human TLR2. The intracellular Toll/interleukin-1R homology domain of type 1 and type 2 was perfectly identical to each other and highly homologous (80.7%) to that of human TLR2. Both types were widely detected by reverse transcriptase-polymerase chain reaction and immunoblotting in various chicken organs, especially those rich in connective tissue. Both genes were mapped to chromosome 4q1.1, suggesting that they arose by gene duplication. By reporter gene assay, type 2 and to a lesser extent type 1, selectively signaled the presence of mycoplasma macrophage-activating lipopeptide-2/M161Ag in the human embryonic kidney 293 cell system. Cotransfection of type 2 and human CD14 or MD-2 into human embryonic kidney 293 cells allowed the response to Escherichia coli lipopolysaccharide (LPS), whereas type 1 did not signal LPS or any other microbial components tested. These results indicated that chTLR type 2 covers two major microbe patterns, lipoproteins and LPS, which are regulated by TLR2 and TLR4 in mammals. In oviparous animals, the duplicated TLRs in the pattern-recognition system may function for host-pathogen discrimination in a manner that is distinct from that in mammals.

High serum levels of additional IL-18 forms may be reciprocally correlated with IgE levels in patients with atopic dermatitis

We established an ELISA system for determination of as yet unidentified species of interleukin 18 (IL-18), named IL-18 type 2, in human serum. Serum IL-18 levels and their effect on IgE levels were examined in 18 patients with atopic dermatitis (AD) with no other allergic symptoms. Three of these patients showed high IL-18 type 2 concentrations (25-100 ng/ml) in their blood serum, and this IL-18 type 2 was detectable only with our established ELISA system. In contrast, the level of the conventional form of IL-18 (type 1) was found to be 50-400 pg/ml in all patients by the commercially available ELISA. The levels of type 1 IL-18 showed no correlation with those of type 2 and approximately 2-fold higher in AD patients than in normal subjects. IL-12 p40 and IgE levels were correlated in the patients with no IL-18 type 2, and interestingly, relatively low IgE concentrations were detected in the three IL-18 type 2-positive patients. They showed considerable levels of IL-12 p40 unlike normal subjects. The IFNgamma-inducing activity of IL-18 type 2 was >100-fold less potent by weight ratio than that of a recombinant 'active' IL-18 preparation, even after the treatment with Caspase 1. Although the relationship between AD and serum IgE levels is not clear cut, IL-18 type 2 appears to play some roles in the Th2-polarization involving IgE production in association with immune responses occurring in local inflammatory milieu such as atopic lesions.

Dietary sesame seeds elevate alpha- and gamma-tocotrienol concentrations in skin and adipose tissue of rats fed the tocotrienol-rich fraction extracted from palm oil

The metabolism of tocotrienol remains unclear. We studied the distribution of tocotrienol in rats fed the tocotrienol-rich fraction extracted from palm oil. We have previously shown that dietary sesame seeds markedly elevate the tocopherol concentration in rats. In this study, we also examined the effect of dietary sesame seeds on the tocotrienol concentration. In experiment 1, rats (4-wk-old) were fed the diet with alpha-tocopherol alone or with alpha- and gamma-tocotrienols. In experiment 2, the effect of dietary sesame seeds on tocopherol and tocotrienol concentrations in rats fed the diet with tocopherol and tocotrienol was studied. The rats were fed the experimental diet for 8 wk in both experiments. alpha- and gamma-Tocotrienols accumulated in the adipose tissue and skin, but not in plasma or other tissues, of the rats fed tocotrienols. Dietary sesame seeds elevated (P < 0.05) tocotrienol concentrations in the adipose tissue and skin, but did not affect their concentrations in other tissues or in plasma. The gamma-tocopherol concentration in all tissues and plasma of rats fed gamma-tocopherol was extremely low but was elevated (P < 0.05) in many tissues by feeding sesame seeds. These data suggest that the transport and tissue uptake of vitamin E isoforms are different. Dietary sesame seeds elevate the concentrations of both tocopherols and tocotrienols.

Protein polymorphism of human IL-18 identified by monoclonal antibodies

Six mAbs were raised against human "functionally inactive" recombinant IL-18, ELISA for determination of "functionally inactive" forms of IL-18 were established using two of these mAbs (#21 and #132), and inactive species of IL-18 protein were examined with human blood plasma and macrophages (Mp). In 6-day GM-CSF-treated monocytes, namely Mp, the mAb #21 recognized the IL-18 proform (24 kDa) and a 48 kDa dimer by immunoblotting. In contrast, only the 24 kDa species was detected as a relatively faint band with a commercial mAb against "active" IL-18. No IL-18 species was detected in premature monocytes. Thus, the dimeric IL-18 was produced in Mp and detectable with the mAb we established. In blood plasma of normal subjects and patients, the #21-recognizable IL-18 was also detected by ELISA, the levels of which were not consistent with those obtained with the commercially available kit for determination of "functionally active" IL-18. We designated the former as type 2 and the latter as type 1. Strikingly, IL-18 type 1 was detected in all volunteers while type 2 was detected in approximately 30% of healthy subjects, and the levels of type 2 were high (10-100 ng/ml) compared to those of type 1 (0.02-0.55 ng/ml) in their blood plasma. In patients with atopic dermatitis, the mean value of type 1 was high (200 ng/ml) compared to those of normal subjects (0.122 ng/ml) and patients with lung cancer (0.113 ng/ml). Production of high type 1 may be associated with an immunomodulatory state in atopic dermatitis. The levels and frequencies of IL-18 type 2 were not significantly changed among these populations. Hence, large amounts of type 2 species are produced in monocyte-Mp differentiation, and their levels and frequencies are unchanged in blood plasma irrespective of the levels of type 1.

Economic evaluation of universal BCG vaccination of Japanese infants

BACKGROUND

The international controversy surrounding the use and effectiveness of the Bacillus Calmette-Guérin (BCG) vaccine and the low incidence of tuberculosis (TB) among Japanese children prompted this study.

METHODS

We compared 'universal BCG vaccination' with 'no vaccination at all' using a cost-effectiveness analysis. The study population was a hypothetical cohort comprising a total of 1.2 million infants born in 1996 at locations all over Japan. A model was developed to calculate the number of TB cases prevented by the vaccination programme. Assuming 40-80% overall vaccine efficacy (64-86% for TB-meningitis) and 10 years of protection, we calculated the cost and number of immunizations required to prevent one child from developing TB, the total number of TB cases averted by vaccination and total costs required for the programme.

RESULTS

Based on an assumption of flexible vaccine efficacy (40-80%), we estimated that 111-542 TB cases including 10-27 of TB-meningitis would be prevented during the 10 years after BCG vaccination among the cohort of infants born in 1996. About US$35 950-175 862 or 2125-10 399 immunizations would be required to prevent one child from developing TB. Sensitivity analyses covering a wide duration of protection, incidence of TB, vaccine coverage and discount rate, revealed that other than vaccine efficacy, the cost of preventing a single case of TB is highly sensitive to the duration of BCG protection and TB incidence.

CONCLUSION

The cost per case of TB prevented is heavily dependent on vaccine efficacy and the duration of protection, and is high compared with the cost of treating one child who has developed TB.

Molecular cloning and functional characterization of guinea pig IL-12

IL-12 is a heterodimeric cytokine that plays a central role in cell-mediated immunity. We cloned complete cDNAs of guinea pig homologues of IL-12 p35 and p40 subunits, and compared their functional properties with human IL-12. Both p35 and p40 mRNA were constitutively expressed in the testis and peritoneal macrophages. On immunoblotting, anti-guinea pig p40 antibody detected the constitutive expression of p40 protein in the testis, while in macrophages it was induced in response to lipopolysaccharide. An unidentified 200-kDa macromolecule was also expressed in the testis. All recombinant hybrid heterodimer p70 (guinea pig p70, human p70 and two interspecies heterodimers) exerted proliferative activity toward concanavalin A-primed guinea pig and human lymphoblasts in a dose-dependent manner. A similar tendency was observed in IFN-gamma production in IL-2-treated human lymphocytes. All hybrid heterodimers also induced IFN-gamma mRNA from IL-2-treated guinea pig splenocytes. Thus, unlike the current concept that the p35 subunit determines the species incompatibility of IL-12 in humans and mice, p35 has marginal ability to define its species-specific functional expression between humans and guinea pigs. In addition, constitutive expression of IL-12 or related molecules in the testis indicated a potential role of this molecule in regulation of physiological or pathophysiological conditions in the reproductive system.

Interferon gamma-producing ability in blood lymphocytes of patients with lung cancer through activation of the innate immune system by BCG cell wall skeleton

An in vitro assay system was developed to assess the potency of the human innate immune system by measurement of IL-12, IL-18, IL-10 and IFNgamma in the supernatants of bacillus Calmette-Guerin cell wall skeleton (BCG-CWS)-stimulated blood samples. BCG-CWS is a ligand for Toll-like receptor (TLR) 2 and 4, and activates monocytes to macrophages (Mphi), and immature dendritic cells to mature antigen-presenting cells (APC). This system was found to allow the discrimination of immune suppressive states in patients with lung cancer from normal immune states in light of the cytokine profile. The following results were deduced from analyses of BCG-CWS-stimulated blood samples of lung cancer patients with reference to normal subjects. (1) The levels of production of IFNgamma and IL-10 by lymphocytes were decreased. (2) IL-12 p40 production by monocytes/Mphi was upregulated, while that of IL-10 was downregulated. (3) IL-18 was detected in all patients in a range similar to normal subjects. (4) Responses of lymphocytes to IL-2 and IL- 18 in terms of IFNgamma production were diminished. (5) The upregulated IL-12 levels were recovered to within the normal range in most patients after tumor resection. (6) Male patients showed more severe suppression of IL-12/IL-18-mediated IFNgamma production than female patients. Thus, the lesser IFNgamma production observed in patients' blood with high IL-12 p40 levels in response to BCG-CWS may reflect the production of p40 dimers or IL-23 instead of p70, or the presence of some unknown pathways to prohibit the interface between the innate and acquired immune systems. BCG-CWS-mediated Toll signaling may participate in IFNgamma induction for lymphocytes through Mphi/APC IL-12/I-18 modulation.