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.

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

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

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.

Frequency of HER2 expression of circulating tumour cells in patients with metastatic or recurrent gastrointestinal cancer.

BACKGROUND: The clinical significance of circulating tumour cell (CTC) detection in gastrointestinal (GI) cancer remains controversial and the molecular biological characteristics of CTCs are poorly understood. METHODS: A total of 87 patients with metastatic or recurrent GI cancer were prospectively enrolled. Circulating tumour cells and their HER2 status were assessed using the CellSearch System. RESULTS: Among the 62 CTC-positive cases, we found 22 discordant cases (35.5%). Among the HER2-negative primary tumours, 17 of 54 developed HER2-positive CTCs. Five of eight had HER2-negative CTCs among the HER2-positive primary tumours. CONCLUSION: The findings in the current study suggest that it is critical to evaluate the HER2 status of not only the primary tumour but also the CTCs because the metastasising tumour cells are the primary target of systemic therapy.

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 17ß-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.

Cognitive function and number of teeth in a community-dwelling elderly population without dementia.

Although the number of sound or decayed teeth has been reported to be associated with cognitive function in elderly populations with dementia, little is known about this association in elderly populations without dementia. We evaluated this relationship, with adjustment for confounding factors, in Japanese populations of 60-year-old (n = 270; 120 males and 150 females) and 65-year-old (n = 123; 57 males and 66 females) individuals residing in Fukuoka Prefecture of Japan. Dental examinations were performed in all subjects, along with the Mini-mental state examination (MMSE) for assessing cognitive function. Among the total of 393 subjects, the mean MMSE score was 27.9 +/- 1.9, and 391 subjects scored 24 or higher. The mean numbers of sound and decayed teeth were 12.0 +/- 6.3 and 0.5 +/- 1.2, respectively. Associations were found between the numbers of sound and decayed teeth and MMSE in total subjects and males, but not in females, by multiple regression analysis adjusted for gender, age, level of education, marital status, smoking, alcohol drinking, working status, systolic blood pressure and blood glucose. An association was also found between MMSE and the number of sound teeth in a logistic regression analysis. In conclusion, associations were found between normal-range cognitive function and the numbers of sound and decayed teeth, after adjustment for various confounding factors, in an elderly Japanese population.

Physical fitness and cognitive function in an 85-year-old community-dwelling population.

BACKGROUND: Little is known about the association between physical fitness and cognitive function in very elderly people (over 80 years of age). OBJECTIVES: To evaluate that relationship in 85-year-old community-dwelling individuals. METHODS: Out of 207 participants (90 males, 117 females) who were 85 years old and community-dwelling, 205 completed the Mini-Mental State Examination (MMSE) for evaluating cognitive function. The numbers of subjects who completed physical fitness measurements such as hand-grip strength, isometric leg extensor strength, one-leg standing time, stepping rate, and walking speed were 198, 159, 169, 168, and 151, respectively. RESULTS: There were significant associations in MMSE with hand-grip strength (right or left hand), isometric leg extensor strength, stepping rate, and walking speed by simple regression analysis. MMSE was still significantly associated with hand-grip strength (beta = 0.305, p = 0.005 for right side; beta = 0.309, p = 0.004 for left side), stepping rate (beta = 0.183, p = 0.046), and walking speed (beta = -0.222, p = 0.014) by multiple regression analysis after adjustments for the amount of education, gender, smoking, drinking, complication of stroke, body weight, body height, regular medical care, serum albumin, blood HbA1c, and marital status. By logistic regression analysis, the prevalence of a normal MMSE score (MMSE >or=24) was increased by 9% with each 1-kg increase in hand-grip strength of the left hand (OR 1.087, 95% CI 1.003-1.179, p = 0.042), and was increased by 6% with each step per 10 s in stepping rate (OR 1.060, 95% CI 1.000-1.122, p = 0.048). CONCLUSION: In a very elderly population of 85-year-olds, cognitive function was associated with some physical fitness measurements, independent of confounding factors.

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.

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 immunohistochemistry 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.

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.

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.

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).

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.

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.

Distribution of IL-18 and IL-18 receptor in human skin: various forms of IL-18 are produced in keratinocytes.

Human interleukin-18 (IL-18) enhances IL-12-mediated IFN-gamma production by lymphocytes and Fas/perforin-mediated cytolysis by NK cells. IL-18 is synthesized as a 24 kDa proform, and the proform is processed in the cytoplasm into an 18 kDa mature form. Active and precursor forms of IL-18 have been detected in immunocompetent cells, and active IL-18 exerts its functions through its receptor. We sought to determine which human skin cells are responsible for production of IL-18 and which express its receptor. Monoclonal antibodies against human IL-18 and polyclonal antibody against IL-18 receptor were provided for this analysis. Formalin-embedded and frozen sections of human epidermis were analyzed by immunoperoxidase and immunofluorescence staining. IL-18 was detected in all living cell layers of the epidermis, hair follicles, arrectores pilorum, eccrine ducts and endothelial cells. IL-18 was localized in the cytoplasm of cells in living epidermal cell layers. In contrast, IL-18 receptor was mainly detected in keratinocytes and expressed in the cell periphery in living cell layers. Since keratinocytes were the main source of IL-18 and its receptor, cultured human keratinocytes were further analyzed by immunoblotting. IL-18 receptor was identified as an 80 kDa single band. The mature 18 kDa and precursor 24 kDa forms of IL-18 were detected by our monoclonal antibody (mAb) 21 and mAb 132, respectively, while only the 18 kDa form was detected by a commercial mAb, 125-2H. Cultured keratinocytes showed positive granular staining for IL-18 in the cytoplasm and positive staining for IL-18 receptor mainly in the cell periphery. Our findings indicate that mature IL-18, precursor IL-18 and IL-18 receptor are simultaneously expressed with different localizations by human epidermal keratinocytes. Keratinocytes might be activated by their own IL-18 in an autocrine or paracrine fashion.

Primary and secondary induction of apoptosis in odontoblasts after cavity preparation of rat molars.

The death regulation of damaged pulp cells after cavity preparation is not well-known. In this study, we examined whether apoptosis is associated with the death regulation of damaged pulp cells. In normal rat molars, terminal deoxynucleotidyl transferase-mediated labeling (TUNEL)-positive cells were not observed. Just after surgery, odontoblasts under cavities were TUNEL-positive, and these signals disappeared in six hours. One day after surgery, we found the reappearance of TUNEL-positive cells in the subodontoblastic region under cavities, and positive signals disappeared in four days. Ultrastructure of TUNEL-positive cells showed characteristics typical of apoptotic cells. Phagocytosis of apoptotic cells by scavenger cells was also observed. By immunohistochemistry, we also found Bcl-2-positive odontoblasts one day after surgery. These results suggest that two waves of apoptosis are induced in odontoblasts after cavity preparation, and that apoptotic cells must be eliminated before the initiation of reparative dentinogenesis.

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.