[A case of hepatocellular carcinoma with autoimmune hepatitis showing marked reduction of tumors by oral administration of UFT-E]

We report a case of hepatocellular carcinoma (HCC) in association with autoimmune hepatitis (AIH). In May 2003, a 66- year-old man was admitted to our hospital because of acute liver dysfunction. He was diagnosed with AIH, and his liver function was normalized by oral administration of the corticosteroid. In July 2007, when he was admitted for the treatment of bacterial pneumonia, two liver tumors (S4: ø4 cm and S2: ø1 cm) were revealed by abdominal CT scan, and the serum level of AFP was high. According to the findings of imaging diagnosis and laboratory data, the patient was diagnosed as having HCC. Since the standard invasive therapies of HCC were not accepted by the patient and his family, he was treated by oral administration of UFT-E (tegafur/uracil: 200 mg/day). Three months after the initiation of administration, CT scan showed a remarkable reduction of the tumors, and his serum AFP level was decreased to the normal range. This case shows that HCC develops in an AIH patient even if liver function is maintained in the normal range. It also suggests the clinical usefulness of UFT-E in the management of HCC given the difficulty of treatment by the standard therapies.

Abdominal ultrasonography as a new modality for the diagnosis of gastroesophageal reflux disease

BACKGROUND AND AIMS

Thickening and abnormal architecture of the esophageal wall in gastroesophageal reflux disease (GERD) have been reported using endoscopic ultrasonography (US), but whether extracorporeal abdominal US is a useful diagnostic modality has not been investigated.

METHODS

Subjects were 37 GERD, 24 non-erosive reflux disease (NERD) patients and 32 controls who visited our hospital from 2006-2009 and underwent upper gastrointestinal endoscopy and extracorporeal abdominal US. The US operator was unaware of any clinical information and examined the following: (i) thickness (>or=5 mm) and (ii) architecture of the esophageal wall; and (iii) presence of reflux. GERD was diagnosed when two or more of these items were positive.

RESULTS

Thickening of the lower esophageal wall in erosive GERD, NERD and controls was 5.7 +/- 0.6, 4.4 +/- 0.8 and 4.7 +/- 0.9 mm, respectively. The thickness in erosive GERD was significantly greater (P < 0.05) than that in NERD patients and controls. Sensitivity, specificity and accuracy of abdominal US diagnosis for erosive GERD and NERD (vs control) was 84.6% (11/13), 25% (6/24), 91.1% (31/34) and 91.1% (31/34), 89.4% (42/47) and 63.8% (37/58), respectively.

CONCLUSION

Extracorporeal abdominal US could be a new useful modality for diagnosing GERD.

The combination of 5-FU, leucovorin and CPT-11 (FOLFIRI) prolongs survival through inhibition of metastasis in an orthotopic model of colon cancer

The aim of this study was to determine the antimetastatic efficacy of the combination of 5-fluorouracil (5-FU), leucovorin (LV), and irinotecan (CPT-11) (FOLFIRI) in an orthotopic nude mouse model of GFP-HCT-116 human colon cancer-expressing green fluorescent protein (GFP). The mice were randomly divided into four groups: Group 1: saline control; Group 2: 30 mg/kg 5-FU + 90 mg/kg LV; Group 3: 5-FU + LV + 16 mg/kg CPT-11 (FOLFIRI); and Group 4: 5-FU + LV + 24 mg/kg CPT-11. 5-FU and LV were administered on days 11, 16 and 21, and CPT-11 on days 12, 18 and 22. Survival in Groups 3 and 4 was significantly longer than that in Groups 1 and 2, although no dose-dependency on CPT-11 was observed. Analysis of the primary and metastatic tumors by GFP imaging, as well as that of oncogene expression in mesentery lymph nodes, demonstrated that tumor growth and metastasis were significantly inhibited or even prevented by FOLFIRI. Pathological evaluation also demonstrated that metastasis was also inhibited by FOLFIRI. The results of the present study suggest FOLFIRI prolongs survival by inhibiting metastasis.

Investigation of the association between the GLC3A locus and normal tension glaucoma in Japanese patients by microsatellite analysis

Purpose:

To investigate whether the GLC3A locus harboring the CYP1B1 gene is associated with normal tension glaucoma (NTG) in Japanese patients.

Materials and Methods:

One hundred forty-two Japanese patients with NTG and 101 Japanese healthy controls were recruited. Patients exhibiting a comparatively early onset were selected as this suggests that genetic factors may show stronger involvement. Genotyping and assessment of allelic diversity was performed on 13 highly polymorphic microsatellite markers in and around the GLC3A locus.

Results:

There were decreased frequencies of the 444 allele of D2S0416i and the 258 allele of D2S0425i in cases compared to controls (P = 0.022 and P = 0.034, respectively). However, this statistical significance disappeared when corrected (Pc > 0.05). We did not find any significant association between the remaining 11 microsatellite markers, including D2S177, which may be associated with CYP1B1, and NTG (P > 0.05).

Conclusions:

Our study showed no association between the GLCA3 locus and NTG, suggesting that the CYP1B1 gene, which is reportedly involved in a range of glaucoma phenotypes, may not be an associated factor in the pathogenesis of NTG.

A study of pyrimidine base damage in relation to oxidative stress and cancer

Background:

A long-standing hypothesis is that oxidative stress is a risk factor for cancer. Support for this hypothesis comes from observations of higher levels of oxidative damage in the DNA of WBC of cancer patients compared with healthy controls.

Methods:

Two generally overlooked types of DNA damage, the formamide modification and the thymine glycol modification, both derived from pyrimidine bases, were assayed as markers of oxidative stress. Damage levels were measured in the DNA of WBC of ovarian cancer patients and of healthy controls.

Results:

The levels of both modifications were higher in ovarian cancer patients than in healthy controls although in the case of the formamide modification age could not be ruled out as a factor.

Conclusion:

Our results in combination with other published measurements of oxidative DNA damage support the hypothesis that oxidative damage, on average, is higher in WBC of cancer patients than in healthy controls.

A protein-bound polysaccharide, PSK, enhances tumor suppression induced by docetaxel in a gastric cancer xenograft model

BACKGROUND

We have reported previously that docetaxel (TXT) induces apoptosis and nuclear factor-kappaB (NF-kappaB) activation, and that blockade of NF-kappaB activation augments TXT-induced apoptosis in human gastric cancer cells. In addition, we have also shown that a protein-bound polysaccharide PSK enhances TXT-induced apoptosis through NF-kappaB inhibition in human pancreatic cancer cells. Based on these observations, in the present study the possibility that PSK could enhance TXT-mediated tumor suppression was examined in vivo and in vitro.

MATERIALS AND METHODS

A gastric cancer xenograft model was used to examine the enhanced TXT-mediated tumor suppression by PSK in vivo. The effects of PSK on proliferation and apoptosis induced by TXT in gastric cancer cells were evaluated in vitro using a human gastric cancer cell line, MK-1. The effect of PSK on increased TXT-induced invasion was also measured.

RESULTS

PSK enhanced TXT-mediated tumor suppression in vivo. Immunohistochemical analyses of the tumors revealed that TXT increased NF-kappaB activation in the tumors and this was suppressed by PSK. In the ex vivo experimental system, PSK enhanced the growth inhibition and apoptosis induced by TXT in the MK-1 cells and reduced the increased invasive ability induced by TXT.

CONCLUSION

PSK enhanced TXT-induced tumor suppression in a gastric cancer xenograft model.

A new arylating agent, 2-carboxy-4,6-dinitrochlorobenzene. Reaction with model compounds and bovine pancreatic ribonuclease

The reagent 2-carboxy-4,6-dinitrochlorobenzene (CDNCB) reacts with the imino, amino and sulfhydryl groups of model compounds. At pH 8.2, sulfhydryl groups react much faster than do amines. N alpha-Acetylhistidine, N alpha-acetyltyrosine and N alpha-acetyltryptophan do not react. Poly(L-Lysine) and poly(DL-lysine) react about 50 times as fast as does N alpha-acetyllysine. A dichloroanalog, 6-carboxy-2,4-dinitro-1,3-dichlorobenzene, shows stepwise reactivity with amines. With bovine pancreatic ribonuclease, which contains no sulfhydryl, CDNCB reacts preferentially with the epsilon-amino of Lys-41 at 450 times the rate with the epsilon-amino of N alpha-acetyllysine. The preferential reactivity at Lys-41 is discussed in relation to the pK of Ly-41, the cationic character of the active site cleft, and the mechanism of RNAase action on substrates.

CEACAM1 and the regulation of mucosal inflammation

Inflammatory bowel disease (IBD) is characterized by unrestrained T-cell activation that results in the production of a variety of inflammatory cytokines and other mediators. Understanding the mechanisms of T-cell regulation is therefore of significant importance to IBD and other forms of dysregulated-mucosal inflammation. An area that is of significant interest are the cell autonomous mechanisms of T-cell regulation through proteins that have natural inhibitory functions when expressed on T lymphocytes. One such molecule is carcinoembryonic antigen cell adhesion molecule 1 (CEACAM1). CEACAM1 is primarily an activation-induced cell-surface molecule that functions as a co-inhibitory receptor. Homophilic ligation of CEACAM1 on T cells leads to a signaling mechanism, which results in inhibition of a broad range T-cell functions. CEACAM1 therefore represents a new potential therapeutic target in the treatment of IBD.

Protein-bound polysaccharide K augments IL-2 production from murine mesenteric lymph node CD4+ T cells by modulating T cell receptor signaling

The protein-bound polysaccharide isolated from basidiomycetes (PSK), a biological response modifier, has been used as immunotherapeutic agent for the treatment of cancers. It has been demonstrated previously that PSK activates various types of immune cells in vitro, and orally administrated PSK activates anti-tumor CD4+ T cell response in mesenteric lymph nodes (MLNs). The detailed mechanism of action of PSK, however, has not been elucidated yet. The objective of the present study was to clarify the molecular mechanism of immunopotentiating effects of PSK using primary culture of the MLN CD4+ T cells. T cell receptor (TCR) stimulation-induced interleukin-2 production from MLN CD4+ T cells was significantly augmented by PSK in a concentration-dependent manner, and the augmentation was reflected at mRNA level. Furthermore, PSK augmented transcriptional activities of nuclear factor of activated T cells and activator protein 1, and phosphorylation of extracellular signal-regulated kinase 1/2 and linker for activation of T cells induced by TCR stimulation, whereas PSK had no influences without TCR stimulation. Collectively, the results indicate that PSK augments activation of MLN CD4+ T cells, probably by modulating the TCR signaling, and provide important knowledge for the elucidation of the true target molecule(s) of PSK.

Absorption and tissue distribution of an immunomodulatory alpha-D-glucan after oral administration of Tricholoma matsutake

Alpha-D-glucan (MPG-1) separated from Tricholoma matsutake (CM6271) has been reported to show immunomodulatory activities. In this study, the plasma concentration and tissue distribution of MPG-1 after CM6271 oral administration were investigated as part of the action mechanism analysis. When CM6271 was orally administered in a single dose to mice, MPG-1 was absorbed via the intestinal tract, appeared in plasma after 16 h, was gradually excreted from the blood, and fell to background level after 48 h. The time course analysis of MPG-1 in plasma showed the following pharmacokinetic parameters of MPG-1: tmax = 24 h; Cmax = 161.1 ng/mL; AUC(0-infinity) = 2559.7 ng x h/mL. Moreover, MPG-1 was confirmed to localize in Peyer's patches, mesenteric lymph nodes (MLN), and the spleen and to promote IL-12 p70 production and NK cell activity. These results suggest that MPG-1 stimulated the intestinal immune system through Peyer's patches; moreover, it was taken into the blood and stimulated the systemic immune system.

Analysis of morphological vascular changes of hepatocellular carcinoma by microflow imaging using contrast-enhanced sonography

AIM

To determine whether the findings of microflow imaging (MFI), composed of a flash replenishment and a maximum intensity holding sequence, using contrast-enhanced sonography, correlate with the degree of histological differentiation of hepatocellular carcinoma (HCC).

METHODS

This study was approved by the institutional review board; patients gave informed consent. The samples comprised of 61 nodules histologically diagnosed as HCC: 20 well-differentiated, 26 moderately-differentiated, and 15 poorly-differentiated HCC. SonoVue was used as the ultrasound (US) contrast agent. The US equipment used was a SSA-770 A with the imaging mode set at MFI. MFI is an imaging method combining flash replenishment imaging and maximum intensity holding. Two independent readers (readers 1 and 2) classified the microflow images into four patterns: (i) normal pattern; (ii) cotton pattern; (iii) vascular pattern; and (iv) dead wood pattern. The results were compared with the degree of histopathological differentiation of the HCC.

RESULTS

In each of the 61 HCC, blood vessels in the tumor were clearly resolved down to their fine branches. With regard to the relationship between imaging patterns and thehistological findings, it was found (with high percentages) that the normal and cotton patterns were associated with well-differentiated HCC, that the vascular pattern was associated with moderately-differentiated HCC, and that the dead wood pattern was associated with poorly-differentiated HCC. If HCC with the normal and cotton patterns were assessed as well differentiated and those with the vascular or dead wood pattern were assessed as moderately or poorly differentiated, the sensitivity, specificity, and accuracy of these assessments were found to be 85%, 92.7%, and 90%, respectively, for reader 1, and 85%, 82.9%, and 83.6%, respectively, for reader 2.

CONCLUSION

The angioarchitecture and hemodynamics of HCC could be evaluated in detail using MFI. The results of this study demonstrate the feasibility of a non-invasive preoperative diagnosis of the histological differentiation of HCC using MFI.

Correlation between parametric imaging using contrast ultrasound and the histological differentiation of hepatocellular carcinoma

AIM

To determine whether parametric imaging correlates with the degree of histological differentiation of hepatocellular carcinoma (HCC).

METHODS

The samples comprised 49 nodules diagnosed histologically as HCC: 19 well differentiated (w-HCC), 22 moderately differentiated (m-HCC), and eight poorly differentiated (p-HCC). The ultrasound (US) equipment used was SSA-770 A (Toshiba Medical Systems, Otawara, Japan) and the contrast agent was SonoVue (Bracco, Milan, Italy). After 1.5 mL of SonoVue was injected intravenously and staining of the tumors and parenchyma was confirmed, microbubbles in the scanned volume were eliminated using high mechanical index (MI) scanning frames. The "arrival time (T(A)) images," reflecting beta-values, were displayed with color codes at the phase after reperfusion. Images at the phase when the staining reached a plateau (90-180 s) were used as "A images," reflecting A values. These images were compared between each histological grade of differentiation.

RESULTS

Analysis of T(A) images indicated that beta-values in m-HCC were higher than those in the adjacent non-tumor parenchyma in all 22 samples and also were significantly higher than in the other HCCs (P < 0.001 for w-HCC; P < 0.05 for p-HCC). Furthermore, beta-values in p-HCC samples had significantly larger variations in terms of time and space than in the other HCCs (P < 0.001 for w-HCC; P < 0.01 for m-HCC). Analysis of A images indicated that the A value for w-HCC was significantly higher than those for either m-HCC or p-HCC (P < 0.001).

CONCLUSION

Both T(A) and A images were useful for diagnosing the histological differentiation of HCC.

Acute impact of volcanic ash on asthma symptoms and treatment

Information about the impacts of disasters on health is useful for establishing hazard prediction maps and action plans of disaster management. This study aims at learning effective asthma management from the volcano disaster of Mount Asama eruption in Japan on September 1, 2004. We conducted a cross-sectional study to assess the acute impact of volcanic ash on asthma symptoms and their treatment changes by using a questionnaire completed by 236 adult asthmatic patients and their physicians. In the ashfall over 100g/m2 area, 42.9 percent of asthma patients suffered exacerbations, PEF decreased, asthma treatments increased, and inhalation of beta2 stimulants was used most for exacerbated asthma. Compared to severe asthma patients, mild and moderate asthma patients were most at risk. Severe asthma patients were not affected since most of them knew their asthma status was severe, and did not go outside and kept windows closed. Deteriorated asthma symptoms of wheezing, chest tightness and cough appeared in the ashfall over 100g/m2 area. Ash contained inhalable 10microm diameter particles, and included high concentrations of airway toxic substrates of silica. These data suggest that ashfall over 100 g/m2 is harmful, access to these areas by asthma patients needs to be restricted, and these areas need to improve asthma treatment. In addition, the increase in the proportion of asthma patients with wheeze and cough are diagnostic clues for ash-induced asthma in affected areas, and can be used by doctors to tell whether patients are receiving sufficient asthma treatment.

Decrease in accumulation of ultrasound contrast microbubbles in non-alcoholic steatohepatitis

AIM

Non-alcoholic steatohepatitis (NASH) is one of the representative liver diseases in developed countries. Diagnosis of NASH is dependent on histological findings from liver biopsy.

METHODS

The usefulness of contrast ultrasound with Levovist for diagnosis of NASH is described. 2.5 g of ultrasound contrast agent Levovist was injected intravenously. The liver was scanned at 5, 10, 15, 20, 30, 40 and 50 min and changes in microbubble accumulation were evaluated. The signal intensity from regions of interest (ROI) on the contrast images was measured and estimated using time intensity curves (TICs). Twenty-one patients with NASH, 33 with non-alcoholic fatty liver disease (NAFLD) and 10 healthy volunteers (HV) were studied. The signal intensity was measured quantitatively at 5 and 20 min after injection.

RESULTS

There was a statistically significant decrease in NASH, when compared with NAFLD and HV groups. These changes in signal intensity were not correlated to the degree of fibrosis and steatosis in histological study. The sensitivity, specificity and overall accuracy obtained from the receiver operating characteristic (ROC) curve were 100% when the cut-off value was set at 43.6 of signal intensity at 20 min.

CONCLUSION

The Levovist contrast study is a useful screening examination which picks up NASH among fatty liver patients.

Parametric imaging of contrast ultrasound for the evaluation of neovascularization in liver tumors

AIM

To assess the efficacy of parametric imaging for the diagnosis of neovascularization in liver tumors.

METHODS

The subjects were 17 rabbits (five with normal liver and 12 with VX2 tumor implanted in the liver). The contrast agents used were SonoVue (Bracco, Milan, Italy). A diagnostic ultrasound system was used with a programmable replenishment sequence. The images obtained between the initial frame after the high mechanical index (MI) scan, which diminishes microbubbles in the scan volume, and the current frame were coded in color according to the arrival and peak times. After the experiment, the tumors were excised and sectioned. Sections were prepared for light microscopy with hematoxylin-eosin (HE) staining and CD31 staining to evaluate vascular density.

RESULTS

Arrival time imaging (ATI) delineated the fine blood vessels (100-200 mum in diameter) in all of the rabbits. Tortuous and meandering tumor vessels were visualized in the VX2 tumors. Differences of perfusion velocity between tumor tissue and tumor-free areas were shown in peak time imaging (PTI). Vascularity evaluated on the ATI and perfusion speed recognized on the ATI and PTI were related to the vascular density measured by pathological investigation.

CONCLUSION

Parametric imaging is a promising new method for the visualization of perfusion and the estimation of tumor blood vessels.

Phagocytosis of ultrasound contrast agent microbubbles by Kupffer cells

Delayed parenchymal phase images of the liver more than 5 min after IV injection of ultrasound contrast agents are thought to be related to the phagocytosis of contrast agent microbubbles by macrophages. In this study, we examined whether liver-specific macrophages, Kupffer cells, phagocytosed the microbubbles and whether their elimination affected the delayed parenchymal images of the liver. Phase-contrast microscope observations showed that Kupffer cells phagocytosed various contrast agents in vitro. Among the contrast agents used, 99% of Sonazoid and Optison, and 47% of Levovist were phagocytosed, whereas only 7.3% of SonoVue and 0% of Imavist were phagocytosed. Elimination of Kupffer cells in vivo by gadolinium chloride (GdCl(3)) resulted in decreased intensity of the delayed parenchymal images with Sonazoid and Levovist, while SonoVue showed no changes compared with control. Our findings suggested that Kupffer cells phagocytosed contrast agents and they were responsible for the delayed images of contrast ultrasound in the liver.

Dynamic US contrast study of the liver: Vascular and delayed parenchymal phase

We evaluated the time-intensity curves of the ultrasound contrast agent, Levovist, in the aorta, portal vein and liver parenchyma in order to define distribution of the agent when it is administered by an intravenous bolus injection. Twelve healthy volunteers were studied. All 12 subjects were examined for the study of vascular phase and five of the subjects were examined for the study of delayed parenchymal phase. To evaluate vascular enhancement, transverse abdominal scanning was performed. To evaluate parenchymal enhancement, liver scanning was done just once at 14 time points up to 60 min after injection. The time-intensity curves in the aorta and the portal vein indicated the conventional curves of blood pool agents such as iodine CT agents and gadolinium MRI agents. They showed steep initial rises and peaks at 20 s and 30 s after injection, respectively. Parenchymal enhancement reached a peak five minutes after injection, with a plateau for 20 min subsequently. It has been proved that there are two phases of Levovist contrast ultrasonography, the vascular phase and the delayed parenchymal phase.

Quantification of hepatic parenchymal blood flow by contrast ultrasonography with flash-replenishment imaging

Flash-replenishment (FR) utilizes destruction of microbubbles in the scan volume by high-power ultrasound and enables to observe reperfusion at a low acoustic power. In this paper, we introduced theoretic equation between probability density function (PDF) of the transit time in the scan volume and time intensity curve (TIC) measured by FR method. From the equations, it was explained that the mean transit time (MTT) through the scan volume was calculated from the plateau level and tangent of the initial slope. Animal experiments were also performed to measure TIC in the parenchymal region of the liver using FR method. From the result of the TIC, the variant of the PDF for the transit time was found to be small and the average MTT was 11.1 s. Hepatic blood flow by an ultrasonic transit time flowmeter was also measured in the same experiment, and adequate correlation was obtained from between the two methods. The results suggested that the FR method, which is a noninvasive measurement, can predict the blood flow of the liver.

Ultrasound contrast agent, Levovist microbubbles are phagocytosed by Kupffer cells-In vitro and in vivo studies

Phase contrast microscopy showed that Levovist microbubbles were phagocytosed by cultured Kupffer cells and moved gradually toward the nucleus from the cell surface. They were diminished in size and disappeared within 30min by diffusion of the gas contained within the microbubbles. In an in vivo study, confocal laser scanning microscopy demonstrated that Levovist microbubbles were trapped and phagocytosed by Kupffer cells. No microbubbles were observed attached to the sinusoidal endothelium. Our findings suggest that liver-specific images obtained following intravenous injection of Levovist are composed of signals from microbubbles phagocytosed by Kupffer cells.

Phase II study of the efficacy of gefitinib in patients with non-small cell lung cancer with the EGFR mutations

7183

Purpose: Recent studies have indicated that the mutations of epidermal growth factor receptor (EGFR) were associated with sensitivity of non-small cell lung cancer (NSCLC) to gefitinib, an EGFR tyrosine kinase inhibitor. The clinical objective of this study was to prospectively evaluate the efficacy of gefitinib in patients with stageIII/IV NSCLC that had the EGFR mutations. Methods: Genomic DNA was extracted from tumor specimens and EGFR mutations in exon 19 and 21 were analyzed by direct sequencing. Patients with stageIII/IV NSCLC who had the EGFR mutations were treated with gefitinib (250mg) orally. Response, survival data and toxicity were assessed. Results: From Nov. 2004 to Dec 2005, 14 patients with the EGFR mutations received gefitinib (median age: 67 years; 2 males, 12 females; 1 smokers, 13 non-smokers; all adenocarcinomas). Two patients discontinued gefitinib and came off study because of interstitial pneumonitis (grade 3) and acne (grade 3), respectively. Response data are available for 12 patients. Two achieved a complete response (CR), seven exhibited a partial response (PR) and three had stable disease (SD). Response rate and disease control rate were 75% and 100%, respectively. There were no grade 3/4 toxicities in these 12 patients. All patients were alive during median follow-up period of 8 months (range 1–13 months). Conclusions: The EGFR mutations could be an excellent predictor of response to gefitinib in NSCLC.

No significant financial relationships to disclose.

Isolation and characterization of a novel immunomodulatory alpha-glucan-protein complex from the mycelium of Tricholoma matsutake in basidiomycetes

Tricholoma matsutake, a high-class edible mushroom in Japan, has been reported to have excellent biological activities, but difficulty in cultivating the fruit bodies and limited bulk availability have restricted detailed studies. We have developed a method of culturing in tanks, enabling the bulk supply of the mycelia. The preparation (CM6271) exerts modulative effects on the immune competence of mice and rats. In this study, a sodium hydroxide extract of CM6271 was defatted followed by fractionation with a combination of ion exchange chromatography and gel filtration in order to identify the components involved in the expression of the activity, and a single peak fraction (MPG-1) was obtained with reversed phase chromatography. MPG-1 was a glycoprotein (sugar:protein ratio, 94.3:5.7) with a relative molecular mass of 360 kDa, and the sugar moiety contained about 90% glucose. NMR spectra and methylation analysis revealed that the alpha-1,4-linkage was the predominant glucan linkage with alpha-1,6- and alpha-1,2-linkages in the minority. The amino acid composition in the protein moiety was rich in glutamine, alanine, asparagine, leucine, glycine, valine, serine, threonine, isoleucine, and proline. MPG-1 was resistant to degradation with amylase or protease. The oral administration of MPG-1 promoted, in a dose-dependent manner, the recovery of the mouse natural killer cell activity and serum IL-12 level that had been reduced by the loading of restraint stress. The dose of MPG-1 (25 mg/kg) required for the expression of the effect decreases to 1/12 of that of CM6271 (300 mg/kg). Furthermore, MPG-1 formed a complex with TGF-beta1 in vitro, modulating the biological activity of TGF-beta1 by binding to its active form. These results indicate that the mycelium of T. matsutake contains a novel alpha-glucan-protein complex with immunomodulatory activities.