High-output stoma is a risk factor for stoma outlet obstruction in defunctioning loop ileostomies after rectal cancer surgery.

PURPOSE: Defunctioning loop ileostomy has been reported to reduce symptomatic anastomotic leakage after rectal cancer surgery; however, stoma outlet obstruction (SOO) is a serious postileostomy complication. We, therefore, explored novel risk factors for SOO in defunctioning loop ileostomy after rectal cancer surgery. METHODS: This is a retrospective study that included 92 patients who underwent defunctioning loop ileostomy with rectal cancer surgery at our institution. Among them, 77 and 15 ileostomies were created at the right lower abdominal and umbilical sites, respectively. We defined the output volumeMAX as the maximum output volume the day before the onset of SOO or-for those without SOO-that was observed during hospitalization. Univariate and multivariate analyses were performed to evaluate risk factors for SOO. RESULTS: SOO was observed in 24 cases, and the median onset was 6 days postoperatively. The stoma output volume in the SOO group was consistently higher than that in the non-SOO group. In the multivariate analysis, the rectus abdominis thickness (p < 0.01) and output volumeMAX (p < 0.01) were independent risk factors for SOO. CONCLUSION: A high-output stoma may predict SOO in patients with defunctioning loop ileostomy for rectal cancer. Considering that SOO occurs even at umbilical sites with no rectus abdominis, a high-output stoma may trigger SOO primarily.

Increased risk of incisional hernia after stoma closure in patients with colorectal cancer.

PURPOSE: Stoma construction and closure are common surgical strategies in patients with colorectal cancer. The present study evaluated the influence of multiple incisional sites resulting from stoma closure on incisional hernia after colorectal cancer surgery. METHODS: The study included 1681 patients who underwent colorectal cancer surgery. Multiple incisional sites were defined as the coexistence of incisions at the midline and stoma closure sites. We retrospectively investigated the relationship between the presence of multiple incisional sites and incisional hernia development in patients with colorectal cancer. RESULTS: Among the 1681 patients, 420 (25%) underwent stoma construction, with a stoma closure-to-construction ratio of 33% (139/420), and 155 (9.2%) developed incisional hernias after colorectal cancer surgery. In the multivariate analysis, female sex (p < 0.001), body mass index (p < 0.001), multiple incisional sites (p = 0.001), wound infection (p = 0.003), and postoperative chemotherapy (p = 0.030) were independent predictors of incisional hernia. In the multiple incisional sites group, the age (p < 0.001), surgical approach (laparoscopic) (p = 0.013), wound infection rate (p = 0.046), small bowel obstruction rate (p < 0.001), and anastomotic leakage rate (p = 0.008) were higher in those in the single incisional site group. CONCLUSIONS: Multiple incisional sites resulting from stoma closure are associated with the development of incisional hernia following colorectal cancer surgery.

Inhibition of protein kinase C delta leads to cellular senescence to induce anti-tumor effects in colorectal cancer.

Protein kinase C delta (PKCδ) is a multifunctional serine-threonine kinase implicated in cell proliferation, differentiation, tumorigenesis, and therapeutic resistance. However, the molecular mechanism of PKCδ in colorectal cancer (CRC) remains unclear. In this study, we showed that PKCδ acts as a negative regulator of cellular senescence in p53 wild-type (wt-p53) CRC. Immunohistochemical analysis revealed that PKCδ levels in human CRC tissues were higher than those in the surrounding normal tissues. Deletion studies have shown that cell proliferation and tumorigenesis in wt-p53 CRC is sensitive to PKCδ expression. We found that PKCδ activates p21 via a p53-independent pathway and that PKCδ-kinase activity is essential for p21 activity. In addition, both repression of PKCδ expression and inhibition of PKCδ activity induced cellular senescence-like phenotypes, including increased senescence-associated ß-galactosidase (SA-ß-gal) staining, low LaminB1 expression, large nucleus size, and senescence-associated secretory phenotype (SASP) detection. Finally, a kinase inhibitor of PKCδ suppressed senescence-dependent tumorigenicity in a dose-dependent manner. These results offer a mechanistic insight into CRC survival and tumorigenesis. In addition, a novel therapeutic strategy for wt-p53 CRC is proposed.

Fluctuating patency of atherosclerotic cervical internal carotid artery treated by carotid endarterectomy successfully: a case report.

Spontaneous recanalization of an atherosclerotic internal carotid artery (ICA) occlusion has been previously reported as a rare phenomenon, but spontaneous re-occlusion shortly after recanalization under antiplatelet therapy has not been documented yet. A 63-year-old man presented with impaired consciousness and left-sided hemiparesis. Magnetic resonance imaging showed new infarction in the right middle cerebral artery territory because of right cervical internal carotid artery occlusion, which became spontaneously patent on computed tomography angiography on the sixth day of admission. So carotid endarterectomy was planned. However, the ICA was recurrently occluded on the preoperative magnetic resonance angiogram three weeks later on admission, which condition was also confirmed during the subsequent surgery. In patients with severe ICA stenosis, patency may dynamically change even under antiplatelet therapy.

Time Courses of Gastric Volume and Content after Different Types of Casein Ingestion in Healthy Men: A Randomized Crossover Study.

BACKGROUND: Few studies have evaluated differences in the curd-forming ability of casein on gastric volume and content directly after ingestion in humans. OBJECTIVES: This study evaluated the time course of gastric volume and curd conditions in the stomach after protein ingestion. METHODS: This was an open-labeled, randomized crossover trial. Ten healthy men [age: 33.4 ± 7.3 y; BMI (kg/m2): 21.9 ± 0.9] received 350 g of 3 isonitrogenous and isocaloric protein drinks containing 30 g micellar casein (MCN), sodium caseinate (SCN), or whey protein concentrate (WPC). The gastric antrum cross-sectional area (CSA) and curd in the stomach were measured using ultrasonography within 5 h after ingestion. The differences between test foods were tested using the MIXED model and post hoc tests using Fisher's protected least significant difference. RESULTS: The incremental AUC of the gastric antrum CSA after MCN ingestion was 1.3-fold and 1.5-fold higher than that after the ingestion of SCN and WPC, respectively (both P < 0.05), but not different between SCN and WPC. The number of participants with curds ≥20 mm with a high echogenicity clot observed in the stomach within 5 h after MCN ingestion was significantly greater than that after the ingestion of other proteins (n = 9 for MCN, n = 2 for SCN, and n = 0 for WPC; bothP < 0.01). The regression line slopes on total plasma amino acid concentration and gastric antrum CSA were significantly different between the participants with and without curds. CONCLUSIONS: In contrast to SCN and WPC, MCN ingestion resulted in slow kinetics of gastric antrum CSA. Differences in curd formation of casein in the stomach affect gastric emptying and plasma amino acid absorption kinetics after ingestion in healthy men. This trial was registered at University Hospital Medical Information Network Clinical Trials Registry as UMIN000038388 (https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000043746).

Comparative examination of levodopa pharmacokinetics during simultaneous administration with lactoferrin in healthy subjects and the relationship between lipids and COMT inhibitory activity in vitro.

Background: Lactoferrin (bLF) is an iron-binding multifunctional protein that is abundant in milk. In mice, it inhibits catechol-O-methyltransferase (COMT) activity and increases blood levodopa levels. However, the clinical effects are unknown.Objective: The objective of this study was to determine the effect of bLF on the kinetics of levodopa in blood.Design: The effects of the concomitant administration of a combined formulation of levodopa and an aromatic amino acid decarboxylase inhibitor and bLF on the concentration of levodopa in blood and its metabolism were assessed in eight healthy subjects. In addition, we analyzed the association with clinical factors and evaluated whether clinical factors affected the COMT inhibitory activity of bLF in vitro.Results: Although not statistically significant, the peak plasma concentration (Cmax) of levodopa increased by 18.5%. From the results of the stratified analysis of total cholesterol, a relationship with ΔCmax was predicted. Therefore, bLF was reacted with cholesterol in the presence of lecithin and sodium deoxycholate in vitro to evaluate COMT inhibitory activity, and an increase in inhibitory activity was observed. By contrast, the ester compound cholesteryl oleate had no effect. The inhibitory activity of free fatty acids, which are known to interact with bLF, was also enhanced.Conclusion: The COMT inhibitory activity of bLF is not effective in elevating blood levodopa levels. However, in humans with high lipid levels, such as cholesterol, interactions may enhance the inhibitory effect, resulting in the enhanced absorption of levodopa.Trial registration: ID, UMIN000026787, registered 30 March 2017; URL, https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000030749Trial registration: UMIN Japan identifier: UMIN000026787.

Hemodynamic changes during the obliteration process for cerebral arteriovenous malformations after radiosurgery.

OBJECTIVE: The process of cerebral arteriovenous malformation (AVM) obliteration following radiosurgery is poorly understood. Authors of this retrospective study aimed to assess the changes in AVM hemodynamics after stereotactic radiosurgery (SRS) by using 3D flow magnetic resonance imaging (MRI) to elucidate the process of AVM obliteration. METHODS: Twenty-four patients with AVMs treated with SRS between July 2015 and December 2017 were included in this study and classified into two groups depending on the duration of AVM obliteration: group A, obliteration within 3 years (n = 15); and group B, obliteration taking more than 3 years or no obliteration (n = 9). Blood flow (ml/min) in the largest feeding artery was measured before and after SRS by using time-averaged 3D flow MRI. The decreasing rate of blood flow in the feeding artery after SRS was calculated as the percent change from baseline blood flow. A Wilcoxon rank-sum test was used to compare the decreasing blood flow rate between the two groups at 4 and 12 months after SRS. RESULTS: For the entire cohort, the mean decrease in blood flow in the feeding artery from baseline was 29% at 4 months and 71% at 12 months after SRS. In general, blood flow after SRS decreased faster in group A and slower in group B. The decreasing rates in blood flow at 4 and 12 months after SRS were significantly different between the two groups (p = 0.02 and < 0.001, respectively). CONCLUSIONS: Tracking changes in AVM hemodynamics after SRS may be useful for assessing the progress of AVM obliteration and the therapeutic effects of SRS, possibly contributing to the prediction of subsequent obliteration outcome.

[A case of unresectable intrahepatic cholangiocarcinoma receiving sustainable pembrolizumab therapy].

A 65-year-old man had unresectable intrahepatic cholangiocarcinoma with a malignant biliary stricture. We used an endoscopic plastic stent to drain the bile. Despite receiving standard chemotherapy, the tumor eventually progressed and cancerous peritonitis developed. We had to exchange plastic stents frequently because of stent occlusion. We had a re-biopsy with EUS-FNA and tested for microsatellite instability, which came back as MSI-high. We administered pembrolizumab, which resulted in a significant reduction of tumor size. We were able to administer long-term chemotherapy without serious side effects by repeatedly exchanging plastic stents for stent occlusion. He has maintained partial response for more than 20 months after receiving pembrolizumab.

[A case of SIADH due to pancreatic cancer was improved by tolvaptan].

We report the case of a 68-year-old man, who presented in emergency care with inarticulate speech. The patient was diagnosed with syndrome of inappropriate antidiuretic hormone (SIADH) associated with pancreatic cancer. All diagnostic criteria for SIADH were met, and cancer of the pancreatic tail was identified by computed tomography. Standard treatment for SIADH includes water restriction, oral NaCl, continuous intravenous infusion of 3% NaCl, and intravenous infusion of furosemide. However, these treatments have varying effectiveness and are difficult for both patients and medical staff. Furthermore, unless treatment of the underlying disease is successful, continued hospitalization is needed and the patient's quality of life is significantly impaired. In this case, hyponatremia improved with this standard treatment, but ascites and edema developed. We treated the patient with tolvaptan due to decreased cardiac function, and symptoms improved rapidly. Although surgery and chemotherapy could not be performed for pancreatic cancer, the SIADH was treated for 7 months without relapse. In summary, a case of SIADH complicated by pancreatic cancer was difficult to control with standard treatment, but responded rapidly to tolvaptan, and outpatient treatment could be continued for a long period. Tolvaptan is useful for the treatment of SIADH associated with cancer.

[A case of thrombotic microangiopathy during chemotherapy with gemcitabine in a patient with pancreatic cancer].

A 57-year-old male patient with unresectable pancreatic head cancer was treated with chemotherapy, 5 courses of gemcitabine plus nab paclitaxel therapy, and 9 courses of gemcitabine monotherapy. After 12 months of treatment, he was admitted to our hospital with headache and dyspnea. He was diagnosed with gemcitabine-induced thrombotic microangiopathy (TMA) due to acute kidney dysfunction, hemolytic anemia, and thrombocytopenia. Gemcitabine was discontinued, and symptoms were improved without using hemodialysis and plasma exchange. After his renal function recovered, we started S-1 chemotherapy. Eighteen months later, the patient was alive. Looking back, we realized that fragment red blood cells appeared in complete blood count and serum LDH elevated at 5 months prior to admission, serum creatinine level increased slowly at 4 months prior to admission, and blood pressure elevated significantly at 2 months prior to admission. Therefore, physicians must be aware of TMA as a possible adverse event to gemcitabine. As in this case, hemolytic findings and hypertension in patients treated with gemcitabine may help early detection of TMA.

1H NMR metabolomic and transcriptomic analyses reveal urinary metabolites as biomarker candidates in response to protein undernutrition in adult rats.

Protein undernutrition contributes to the development of various diseases in broad generations. Urinary metabolites may serve as non-invasive biomarkers of protein undernutrition; however, this requires further investigation. We aimed to identify novel urinary metabolites as biomarker candidates responsive to protein undernutrition. Adult rats were fed control (CT; 14 % casein) or isoenergetic low-protein (LP; 5 % casein) diets for 4 weeks. 1H NMR metabolomics was applied to urine, plasma and liver samples to identify metabolites responsive to protein undernutrition. Liver samples were subjected to mRNA microarray and quantitative PCR analyses to elucidate the mechanisms causing fluctuations in identified metabolites. Urinary taurine levels were significantly lower in the LP group than in the CT group at week 1 and remained constant until week 4. Hepatic taurine level and gene expression level of cysteine dioxygenase type 1 were also significantly lower in the LP group than in the CT group. Urinary trimethylamine N-oxide (TMAO) levels were significantly higher in the LP group than in the CT group at week 2 and remained constant until week 4. Hepatic TMAO level and gene expression levels of flavin-containing mono-oxygenase 1 and 5 were also significantly higher in the LP group than in the CT group. In conclusion, urinary taurine and TMAO levels substantially responded to protein undernutrition. Furthermore, changes in hepatic levels of these metabolites and gene expressions associated with their metabolic pathways were also reflected in their fluctuating urinary levels. Thus, taurine and TMAO could act as non-invasive urinary biomarker candidates to detect protein undernutrition.

Comparison of isolation methods using commercially available kits for obtaining extracellular vesicles from cow milk.

Extracellular vesicles (EV) are important for delivering biologically active substances to facilitate cell-to-cell communication. Milk-derived EV are widely known because of their potential for immune enhancement. However, procedures for isolating milk-derived EV have not been fully established. To obtain pure milk-derived EV and accurately reveal their function, such procedures must be established. The aim of the present study was to compare methods using commercially available kits for isolating milk-derived EV. Initially, we investigated procedures to remove casein, which is the major obstacle in determining milk-derived EV purity. We separated whey using centrifugation only, acetic acid precipitation, and EDTA precipitation. Then, we isolated milk-derived EV by ultracentrifugation, membrane affinity column, size exclusion chromatography (SEC), polymer-based isolation, or phosphatidylserine-affinity isolation. Using EV count per milligram of protein, which is a good indicator of purity, we determined that acetic acid precipitation was the best method for removing casein. Using nanoparticle tracking analysis, protein quantity analysis, and RNA quantity analysis, we comprehensively compared each isolation method for its purity and yield. We found that SEC-based qEV column (Izon Science) could collect purer milk-derived EV at higher quantities. Thus, a combination of acetic acid precipitation and qEV can effectively isolate high amounts of pure extracellular vesicles from bovine milk.

A More Oxidized Plasma Albumin Redox State and Lower Plasma HDL Particle Number Reflect Low-Protein Diet Ingestion in Adult Rats.

BACKGROUND: Plasma albumin (ALB) redox state reflects protein nutritional status, but how it differs from other protein nutrition biomarkers remains to be fully elucidated. OBJECTIVE: This study aimed to delineate the characteristics of plasma ALB redox state as a protein nutrition biomarker. METHODS: Adult male Wistar rats were maintained on an AIN-93 M [14% casein, control (CT)] diet or an AIN-93 M-based 5% casein [low protein (LP)] diet ad libitum for 4 wk. Plasma samples were repeatedly obtained from the same rats at weeks 0-4, ALB redox state was determined by HPLC, and the concentrations of conventional protein nutrition biomarkers, ALB and transthyretin (TTR), were compared between the groups by Student t test. Body mass, relative muscle masses, plasma proteome, and plasma lipids at week 4 were also compared. RESULTS: Plasma ALB redox state shifted to a more oxidized state in the LP diet group compared with the CT diet group at weeks 1-4. The LP diet group also showed significantly lower plasma ALB concentrations at weeks 1 and 2 (13% and 11% lower, respectively) and significantly lower TTR concentration at week 1 (21% lower) compared with the CT diet group, but these concentrations did not differ significantly at weeks 3 and 4. After 4 wk, body mass and relative soleus and gastrocnemius muscle masses did not differ, but the relative plantaris muscle mass tended to be 4% lower (1.75 compared with 1.68 g/kg body mass) in the LP diet group compared with the CT group (P = 0.06). The LP diet group also had a significantly lower HDL particle number than the CT group (30% lower). CONCLUSIONS: A more oxidized plasma ALB redox state and lower plasma HDL particle number reflect LP diet ingestion in adult rats, which did not exhibit changes of plasma ALB and TTR concentrations.

Epicutaneous immunogenicity of partially hydrolyzed whey protein evaluated using tape-stripped mouse model.

BACKGROUND: Hydrolyzed cow's milk protein formulas are widely used for infants with a history or risk of cow's milk allergy. Based on the current theory that food allergen sensitization occurs via the skin, we investigated the epicutaneous immunogenicity of partially hydrolyzed whey proteins, which are ingredients in infant formulas. METHODS: BALB/c mice were exposed epicutaneously to whey protein concentrate (WPC) or partial whey protein hydrolysates (PWH1 or PWH2) on tape-stripped skin. Sensitization was assessed by evaluating serum ß-lactoglobulin (ß-LG)-specific antibodies, basophil activation, and cytokine production from ß-LG-stimulated lymphoid cells. The anaphylaxis reaction was evaluated by measuring the rectal temperature and plasma level of mouse mast cell protease-1 after oral ß-LG challenge. Immune cell accumulation in the skin was also analyzed. RESULTS: Substantive sensitization and ß-LG-induced anaphylaxis reaction were observed in WPC-exposed mice, whereas no significant changes were observed in PWH1- or PWH2-exposed mice. The basophil and eosinophil counts increased in WPC-exposed murine skin, not but in PWH1- or PWH2-exposed mice. CONCLUSION: The epicutaneous immunogenicity of PWH1 and PWH2 is markedly decreased, which may reduce the risk of allergen sensitization. Further studies are required to investigate the clinical value of these partial hydrolysates for high-risk infants.

Correction to: Signification of Systemic Immune-Inflammation Index for prediction of prognosis after resecting in patients with colorectal cancer.

The authors regrets that there is a typo error on Tables 1, 2 and 3 of their published paper.

Signification of Systemic Immune-Inflammation Index for prediction of prognosis after resecting in patients with colorectal cancer.

PURPOSE: Systemic inflammatory response has been reported to be associated with prognosis in cancer patients. The aim of this study is to investigate the association between Systemic Immune-Inflammation Index (SII), a novel inflammation-based prognostic score and long-term outcomes among patients with colorectal cancer (CRC) after resection. METHODS: We retrospectively investigated 733 patients who underwent resection for CRC between January 2010 and December 2014 at the Jikei University Hospital and explored the relationship between SII, calculated by multiplying the peripheral platelet count by neutrophil count and divided by lymphocyte count, and overall survival. In survival analyses, we conducted Cox proportional hazards models, adjusting potential confounders including TNM stage, serum CEA, serum CA 19-9, neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and platelet count. RESULTS: In multivariate analysis, age ≥ 65 years (p = 0.003), tumor location (p = 0.043), advanced TNM stage (p < 0.001), serum CA 19-9 > 37 mU/ml (p < 0.001), and SII (P for trend = 0.017) were independent and significant predictors of poor patient survival. Compared to patients with low SII, those with high and intermediate SII patients had poorer survival (Hazard ratio 2.48; 95% CI 1.31-4.69, Hazard ratio 1.65; 95% CI 0.83-3.27, respectively). CONCLUSION: The Systemic Immune-Inflammation Index might be an independent and significant indicator of poor long-term outcomes in patients with CRC after resection.

Clinical factors affecting the distal margin in rectal cancer surgery.

PURPOSE: In rectal cancer surgery, an insufficient distal margin (DM) is associated with a high risk of local recurrence, whereas an excessive DM will cause low anterior resection syndrome, impairing quality of life. This study aimed to identify the factors that affect the distance between the colorectal resection site and the tumor to optimize achieving the correct DM. METHODS: The subjects of this study were 219 patients who underwent resection for primary rectal cancer in our department between January 2006 and July 2014. According to Japanese guidelines, DM (rDM) was based on the tumor location, but the pathological DM (pDM) was measured from surgical specimens. The patients were divided into two groups: the pDM-less-than-rDM group (pDM < rDM) and the pDM-greater-or-equal-to-rDM group (pDM ≥ DM). The factors associated with the DM in the two groups were compared. RESULTS: In the pDM < rDM group, the tumor distance from the anal verge was shorter (p = 0.001) and significantly more patients underwent laparotomy (p = 0.047). CONCLUSION: The DM tended to be shorter than that planned by the surgeon in patients with lower rectal cancers and those treated by laparotomy,; therefore, when performing rectal resection, care must be taken to ensure that the pDM is not shorter than the rDM.

The Combination of Bifidobacterium breve and Three Prebiotic Oligosaccharides Modifies Gut Immune and Endocrine Functions in Neonatal Mice.

BACKGROUND: Several types of oligosaccharides are used in infant formula to improve the gut microbiota of formula-fed infants. We previously reported that a combination of 3 oligosaccharides (lactulose, raffinose, and galacto-oligosaccharides; LRG) and Bifidobacterium breve effectively increased B. breve numbers, acetate, and the expression of several immune- and gut hormone-related mRNAs in neonatal mice gut. OBJECTIVE: We investigated whether changes in neonatal gut microbiota alter gut immune and endocrine development. METHODS: We first compared postnatal day (PD) 14 with PD21 in C57BL/6J male mouse pups to identify the physiologic immune and endocrine changes during development. In a separate study, we administered phosphate-buffered saline (control group; CON), B. breve M-16V (M-16V), or M-16V + LRG to male mouse pups from PD6 to PD13, and analyzed the gut microbiota and immune and endocrine parameters on PD14 to evaluate whether M-16V + LRG accelerates gut immune and endocrine development. RESULTS: The proportion of regulatory T (Treg) cells in the CD4+ cells of large intestinal lamina propria lymphocytes (LPLs) was significantly increased (63% higher) at PD21 compared with PD14. The serum glucagon-like peptide (GLP)-1 tended to be lower (P = 0.0515) and that of GLP-2 was significantly lower (58% lower) at PD21 than at PD14. M-16V + LRG significantly increased the Treg proportion in large intestinal LPL CD4+ cells (20% and 29% higher compared with CON and M-16V, respectively) at PD14. M-16V + LRG also caused significant changes in expression of large intestinal mRNAs that are consistent with developmental progression, and increased serum concentrations of GLP-1 (207% and 311% higher compared with CON and M-16V, respectively) and GLP-2 (57% and 97% higher compared with CON and M-16V, respectively) at PD14. CONCLUSIONS: Neonatal administration of M-16V + LRG alters the gut microbiota and enhances gut immune and endocrine development in suckling mice.

Ingestion of Casein Hydrolysate Induces Oral Tolerance and Suppresses Subsequent Epicutaneous Sensitization and Development of Anaphylaxis Reaction to Casein in Mice.

BACKGROUND: Casein is the most dominant causal allergen in cow's milk allergy (CMA). Casein hydrolysates are frequently applied in infant formulas for children with a risk or history of CMA. However, there is limited information on the oral tolerance-inducing ability of casein hydrolysates. OBJECTIVES: The aim of this study was to investigate whether the ingestion of casein hydrolysate induces tolerance to casein, ultimately preventing subsequent epicutaneous sensitization and development of an anaphylaxis reaction. METHODS: BALB/c mice were orally administered casein or a casein hydrolysate (CNH) via the drinking water and were then epicutaneously sensitized by repeated exposure of casein on tape-stripped skin. Sensitization was assessed by basophil activation tests, the serum levels of casein-specific antibodies, and cytokine production from casein-stimulated spleen and mesenteric lymph node (MLN) cells. Occurrence of an anaphylaxis reaction was evaluated by measuring rectal temperature and the plasma level of mouse mast cell protease-1 (mMCP-1) after oral casein challenges. The T cell population in the spleen and MLN was assessed by flow cytometry. Intestinal mast cells and basophils were analyzed histologically. RESULTS: Sensitization and anaphylaxis reaction to casein were significantly suppressed in casein- or CNH-fed mice compared to controls. Prior ingestion of casein or CNH had no effect on the population of regulatory T cells and activated T cells in lymphoid tissues. Intestinal basophils increased by the epicutaneous sensitization of casein, which was suppressed in casein- or CNH-fed mice. Although the increase in the plasma level of mMCP-1 after oral challenge was suppressed in casein- or CNH-fed mice, there was no change in the number of intestinal mast cells. CONCLUSION: Prior ingestion of casein or CNH induced oral tolerance and suppressed subsequent epicutaneous sensitization and development of systemic anaphylaxis to casein.

Ingestion of partially hydrolyzed whey protein suppresses epicutaneous sensitization to ß-lactoglobulin in mice.

BACKGROUND: Epicutaneous sensitization to food allergens can occur through defective skin barriers. However, the relationship between oral tolerance and epicutaneous sensitization remains to be elucidated. We aimed to determine whether prior oral exposure to whey proteins or their hydrolysates prevents epicutaneous sensitization and subsequent food-allergic reaction to the whey protein, ß-lactoglobulin (ß-LG), and investigated the underlying mechanisms. METHODS: BALB/c mice were given whey protein concentrate (WPC), two kinds of partial whey protein hydrolysate (PWH1 or PWH2), or extensive whey protein hydrolysate (EWH) in drinking water for 21 days. The mice were then epicutaneously sensitized with ß-LG on tape-stripped skin. Sensitization was assessed by basophil activation tests and by measuring the level of serum ß-LG-specific antibodies and cytokines secreted from ß-LG-restimulated spleen and mesenteric lymph node (MLN) cells. Development of an allergic reaction was assessed by monitoring body temperature and by measuring mast cell protease-1 level in plasma after the ß-LG oral challenge. Activated T-cell population among ß-LG-restimulated MLN cells was also analyzed. RESULTS: In mice fed with WPC, PWH1, or PWH2, sensitization and the development of an allergic reaction were totally reduced. The acceleration of cytokine release from the spleen and MLN cells or T-cell activation was not evident after ß-LG restimulation. In EWH-fed mice, a suppressive effect, though milder than that in WPC-, PWH1-, or PWH2-fed mice, was observed during the development of the allergic reaction. CONCLUSIONS: Prior oral exposure to partially hydrolyzed whey protein prevents epicutaneous sensitization and subsequent allergic response to ß-LG in mice.