Salvage pharyngolaryngectomy with total esophagectomy following definitive chemoradiotherapy.

Historically, total pharyngolaryngectomy with total esophagectomy has been the standard radical surgical treatment for synchronous cancer of the thoracoabdominal esophagus and pharyngolaryngeal region, and for cancer of the cervical esophagus that has invaded as far as the thoracic esophagus. Although definitive chemoradiotherapy that enables preservation of the larynx has often been the first choice of treatment for cancers involving the cervical esophagus, total pharyngolaryngectomy with total esophagectomy is required as a salvage therapy for cases involving failure of complete remission or locoregional recurrence after chemoradiotherapy. However, salvage esophageal surgery after definitive high-dose chemoradiotherapy is generally associated with high morbidity and mortality. The aim of this study was to examine the short-term outcome of salvage total pharyngolaryngectomy with total esophagectomy. From 2001 to 2014, nine patients underwent salvage total pharyngolaryngectomy with total esophagectomy at the Department of Gastroenterological Surgery, Nagoya University. The mortality and morbidity rates were high at 22% and 89%, respectively. Four patients (44%) developed tracheal necrosis, which in two patients eventually led to lethal hemorrhage. Salvage total pharyngolaryngectomy with total esophagectomy is an uncommon and highly demanding surgical procedure that should be carefully planned and conducted in selected centers of excellence. Measures must be taken to preserve the tracheal blood supply, thus avoiding fatal complications.

Effect of SGLT2 inhibitors in a murine model of urinary tract infection with Candida albicans.

AIMS: Urinary tract infection (UTI) is a common clinical problem in diabetic patients; however, the relationship between UTI and glucosuria remains uncertain. To investigate the relationship, we examined the effect of glucosuria induced by sodium glucose cotransporter 2 (SGLT2) inhibitors on the progression of UTI in mice. METHODS: From 1 day before transurethral inoculation with Candida albicans, female mice were treated orally once a day with an SGLT2 inhibitor in different treatment regimens: (i) dapagliflozin at 10 mg/kg for 2, 3 or 7 days, (ii) dapagliflozin at 0.1, 1 or 10 mg/kg for 3 days and (iii) dapagliflozin, canagliflozin or tofogliflozin at 10 mg/kg for 3 days. To evaluate the ascending UTI, the kidneys were removed 6 days after the inoculation, and the number of viable C. albicans cells in kidney was measured as colony-forming units (CFU). RESULTS: In mice treated with dapagliflozin, the number of C. albicans CFU in kidney increased in accordance with both treatment duration and dose. The number of CFU significantly increased when mice were treated with 10 mg/kg dapagliflozin or canagliflozin but not tofogliflozin. With dapagliflozin and canagliflozin, urine glucose concentration (UGC) significantly increased up to 24 h after drug administration; with tofogliflozin, UGC significantly increased only up to 12 h after drug administration. CONCLUSIONS: Our data indicate that increased susceptibility to UTI is associated with a persistent increase in UGC.

Orally administered heat-killed Lactobacillus gasseri TMC0356 alters respiratory immune responses and intestinal microbiota of diet-induced obese mice.

AIMS: To investigate the influence of heat-killed Lactobacillus gasseri TMC0356 on changes in respiratory immune function and intestinal microbiota in a diet-induced obese mouse model. METHODS AND RESULTS: Male C57BL/6J mice were fed a high-fat diet for 16 weeks. After 8 weeks, the high-fat-diet-induced obese mice (DIO mice) were randomly divided into two 0067roups, the DIO and DIO0356 groups. DIO0356 group mice were orally fed with heat-killed TMC0356 every day for 8 weeks, while DIO group mice were exposed to 0·85% NaCl over the same time period as controls. After intervention, the pulmonary mRNA expression of cytokines and other immune molecules in DIO0356 mice compared to those in DIO group mice was significantly increased (P < 0·05, P < 0·01). In faecal bacterial profiles, analysed using the terminal restriction fragment length polymorphism (T-RFLP) method, T-RFLP patterns in 75% of the DIO0356 group mice were apparently changed compared with those in control group mice. CONCLUSION: These results suggest that inactive lactobacilli may stimulate the respiratory immune responses of obese host animals to enhance their natural defences against respiratory infection, partially associating with their potent impact on intestinal microbiota. SIGNIFICANCE AND IMPACT OF THE STUDY: We have demonstrated that oral administration of inactive lactobacilli may protect host animals from the lung immune dysfunction caused by obesity.

Association of a polymorphism of BTN2A1 with type 2 diabetes mellitus in Japanese individuals.

AIMS: We previously showed that the C→T polymorphism (rs6929846) of BTN2A1 was significantly associated with myocardial infarction in Japanese individuals by a genome-wide association study. Given that diabetes mellitus is an important risk factor for myocardial infarction, the association of rs6929846 of BTN2A1 with myocardial infarction might be attributable, at least in part, to its effect on susceptibility to diabetes. The purpose of this study was to examine the relation of rs6929846 of BTN2A1 to Type 2 diabetes mellitus. METHODS: A total of 8650 Japanese individuals from two independent subject panels were examined: Panel A comprised 1141 individuals with Type 2 diabetes and 3161 control subjects and panel B comprised 1664 individuals with Type 2 diabetes and 2684 control subjects. RESULTS: The chi-square test revealed that rs6929846 of BTN2A1 was significantly related to the prevalence of Type 2 diabetes in subject panel A (P = 0.0002) and subject panel B (P=0.006). Multivariable logistic regression analysis with adjustment for age, sex, body mass index and smoking status revealed that rs6929846 was significantly associated with Type 2 diabetes (P = 0.0006; odds ratio 1.25) in all individuals, with the T allele representing a risk factor for this condition. Multiple regression analysis with adjustment for age, sex and body mass index revealed that rs6929846 was significantly (P=0.04) related to blood glycosylated haemoglobin content in control subjects. CONCLUSIONS: BTN2A1 may be a susceptibility gene for Type 2 diabetes in Japanese individuals.

Association of interleukin-1 gene polymorphisms with sudden sensorineural hearing loss and Ménière's disease.

Sudden sensorineural hearing loss (SSNHL) and Ménière's disease are the most common inner ear diseases in which the causes are unknown. As recent magnetic resonance imaging has demonstrated disruption of the blood-labyrinth barrier in these inner ear diseases, inflammatory reaction associated with increased permeability of the blood vessels may be involved. The genotypes of interleukin 1A (IL1A) (-889C/T; rs1800587) and interleukin 1B (IL1B) (-511C/T; rs16944) were determined using an allele-specific primer-polymerase chain reaction method in 72 patients with SSNHL, 68 patients with Ménière's disease, and 2202 control subjects living almost in the same area as the patients. A significantly higher prevalence of the IL1A-889T allele was observed in SSNHL and Ménière's disease compared with controls, although no significant difference in distribution of IL1B-511C/T genotypes was observed between the patients and controls. Adjusted odd ratios for SSNHL and Ménière's disease risks in the -889TT genotypes were 25.89 (95% confidence interval (CI) 12.19-54.98) and 18.20 (95% CI 7.80-42.46), respectively, after age and gender were taken as moderator variables. Our results suggested that IL1A is closely associated with susceptibility of SSNHL and Ménière's disease.

Enhancement of immunoregulatory effects of Lactobacillus gasseri TMC0356 by heat treatment and culture medium.

AIMS: The aim of this study was to investigate the influence of heat treatment and culture media on the immunoregulatory effects of a probiotic strain, Lactobacillus gasseri TMC0356 (TMC0356). METHODS AND RESULTS: TMC0356 cultured in deMan-Rogosa-Sharpe and same food grade (FG) media were inactivated with the heat treatment at 70 and 90°C. Viable and heat-killed TMC0356 were tested for their ability to induce interleukin (IL)-12 production in the murine macrophage cell line J774.1. These TMC0356 were examined for their resistance to N-acetylmuramidase. Their morphology was observed by scanning electron microscopy. The heat-killed TMC0356 significantly induced IL-12 production in J774.1 cells and exhibited enhanced resistance to N-acetylmuramidase compared with viable TMC0356. Morphological changes were observed in TMC0356 when cultured in FG medium. Cell morphology and induction of IL-12 production in J774.1 cells were also associated. CONCLUSIONS: These results suggest that heat treatment and culture medium composition modified the immunoregulatory effects of TMC0356 to induce IL-12 production in macrophages. SIGNIFICANCE AND IMPACT OF THE STUDY: These results demonstrate that probiotic immunoregulatory effects may be modified by the processing technology of cell preparation.

Feasibility of virtual surgical simulation in the head and neck region for soft tissue reconstruction using free flap: a comparison of preoperative and postoperative volume measurement.

In the head and neck region, preoperative evaluation of the free flap volume is challenging. The current study validated preoperative three-dimensional (3D) virtual surgical simulation for soft tissue reconstruction by assessing flap volume and evaluated fat and muscle volume changes at follow-up in 13 head and neck cancer patients undergoing anterolateral craniofacial resection. Patients received 3D virtual surgical simulation, and the volume of the planned defects was estimated by surgical simulation. Following en bloc resection of the tumor, the defect in the skull base was covered using a rectus abdominis myocutaneous flap. Following surgery, computed tomography scans were acquired at day 1 and at 6 and 12 months. Virtual planned defect was on average 227 ml (range, 154-315) and was 10% smaller than the actual flap volume in patients without skin involvement of the tumor. Between day 1 and 12 months post-surgery, the volume of fat and muscle tissue in the free flap dropped by 9% and 58%, respectively. Our results indicate that 3D virtual surgical simulation provides essential information in determining the accurate volume of the required free flap for surgical defect repair and may thus help improve surgical planning and functional and esthetic outcome.

Oral administration of lactobacilli from human intestinal tract protects mice against influenza virus infection.

AIMS: Our study was conducted to evaluate the potent protective effects of oral administration of probiotic Lactobacillus strains against influenza virus (Flu) infection in a mouse model. METHOD AND RESULTS: Lyophilized Lactobacillus rhamnosus GG (LGG) and Lactobacillus gasseri TMC0356 (TMC0356) were orally administered to BALB/c mice for 19 days. The test mice were intranasally infected with Flu A/PR/8/34 (H1N1) on day 14, and any changes in clinical symptoms were monitored. After 6 days of infection, the mice were killed and pulmonary virus titres were determined. The clinical symptom scores of mice administered oral LGG and TMC0356 were significantly ameliorated, compared to those of the control mice (P < 0.01). The pulmonary virus titres of the mice fed LGG and TMC0356 were also significantly decreased compared to those of control mice (P < 0.05). CONCLUSIONS: These results indicate that oral administration of lactobacilli, such as LGG and TMC0356, might protect a host animal against Flu infection. SIGNIFICANCE AND IMPACT OF THE STUDY: These results demonstrate that oral administration of selected lactobacilli might protect host animals from Flu infection by interactions with gut immunity.

Intranasal administration of Lactobacillus rhamnosus GG protects mice from H1N1 influenza virus infection by regulating respiratory immune responses.

AIMS: To investigate whether intranasal Lactobacillus administration protects host animals from influenza virus (IFV) infection by enhancing respiratory immune responses in a mouse model. METHODS AND RESULTS: After 3 days of intranasal exposure to Lactobacillus rhamnosus GG (LGG), BALB/c mice were infected with IFV A/PR/8/34 (H1N1). Mice treated with LGG showed a lower frequency of accumulated symptoms and a higher survival rate than control mice (P < 0.05). The YAC-1 cell-killing activity of lung cells isolated from mice treated with LGG was significantly greater than those isolated from control mice (P < 0.01). Intranasal administration of LGG significantly increased mRNA expression of interleukin (IL)-1 beta, tumour necrosis factor (TNF) and monocyte chemotactic protein (MCP)-1 (P < 0.01). CONCLUSIONS: These results suggest that intranasal administration of LGG protects the host animal from IFV infection by enhancing respiratory cell-mediated immune responses following up-regulation of lung natural killer (NK) cell activation. SIGNIFICANCE AND IMPACT OF STUDY: We have demonstrated that probiotics might protect host animals from viral infection by stimulating immune responses in the respiratory tract.

Detailed Arterial Anatomy and Its Anastomoses of the Sphenoid Ridge and Olfactory Groove Meningiomas with Special Reference to the Recurrent Branches from the Ophthalmic Artery.

BACKGROUND AND PURPOSE: Detailed arterial anatomy of the sphenoid ridge and olfactory groove meningiomas is complicated due to the fine angioarchitecture and anastomoses between each feeder. Herein, we present details of the arterial anatomy and the relationships of feeders in these lesions. MATERIALS AND METHODS: This study included 20 patients admitted to our department between April 2015 and March 2020. Conditions of subjects consisted of 16 sphenoid ridge meningiomas and 4 olfactory groove meningiomas. We mainly analyzed arterial anatomy using 3D rotational angiography and slab MIP images of these lesions. We also analyzed the anastomoses of each feeder. RESULTS: We found that 19 (95%), 15 (75%), and 15 (75%) lesions had feeders from the ophthalmic, internal carotid, and external carotid arteries, respectively. As feeders from the ophthalmic artery, recurrent meningeal arteries were involved in 18 lesions (90%). Fifteen lesions (75%) had anastomoses between each feeder. CONCLUSIONS: Most of the meningiomas in the sphenoid ridge and olfactory groove had feeders from the ophthalmic and internal carotid arteries. There were various anastomoses between each feeder. This is the first report to demonstrate the detailed arterial anatomy and frequency of recurrent branches from the ophthalmic artery and their anastomoses using detailed imaging techniques.

Silibinin attenuates amyloid beta(25-35) peptide-induced memory impairments: implication of inducible nitric-oxide synthase and tumor necrosis factor-alpha in mice.

In Alzheimer's disease (AD), the deposition of amyloid peptides is invariably associated with oxidative stress and inflammatory responses. Silibinin (silybin), a flavonoid derived from the herb milk thistle, has potent anti-inflammatory and antioxidant activities. However, it remains unclear whether silibinin improves amyloid beta (Abeta) peptide-induced neurotoxicity. In this study, we examined the effect of silibinin on the fear-conditioning memory deficits, inflammatory response, and oxidative stress induced by the intracerebroventricular injection of Abeta peptide(25-35) (Abeta(25-35)) in mice. Mice were treated with silibinin (2, 20, and 200 mg/kg p.o., once a day for 8 days) from the day of the Abeta(25-35) injection (day 0). Memory function was evaluated in cued and contextual fear-conditioning tests (day 6). Nitrotyrosine levels in the hippocampus and amygdala were examined (day 8). The mRNA expression of inducible nitric-oxide synthase (iNOS) and tumor necrosis factor-alpha (TNF-alpha) in the hippocampus and amygdala was measured 2 h after the Abeta(25-35) injection. We found that silibinin significantly attenuated memory deficits caused by Abeta(25-35) in the cued and contextual fear-conditioning test. Silibinin significantly inhibited the increase in nitrotyrosine levels in the hippocampus and amygdala induced by Abeta(25-35). Nitrotyrosine levels in these regions were negatively correlated with memory performance. Moreover, real-time RT-PCR revealed that silibinin inhibited the overexpression of iNOS and TNF-alpha mRNA in the hippocampus and amygdala induced by Abeta(25-35). These findings suggest that silibinin (i) attenuates memory impairment through amelioration of oxidative stress and inflammatory response induced by Abeta(25-35) and (ii) may be a potential candidate for an AD medication.

Endoscopic submucosal dissection allows less-invasive curative resection for gastric tube cancer after esophagectomy - a case series.

Detection of early gastric tube cancers (GTCs) has increased with more detailed surveillance endoscopy using indigo carmine dye following esophagectomy. This retrospective study clarified the clinicopathological features and application of endoscopic submucosal dissection (ESD) for GTCs. Data collected for eight GTCs treated by ESD included clinical and pathological features and outcomes following ESD. Overall, eight GTCs were identified in seven (6.3 %) of 112 patients who underwent esophagectomy and gastric tube reconstruction. Almost all lesions were macroscopically type 0-IIa with mucosal to submucosal invasion, and seven GTCs were successfully resected en bloc by ESD. Submucosal invasion to > 500 microm was observed in one case with associated delayed perforation that was treated conservatively. No local recurrences of GTCs were observed. Detailed surveillance endoscopy using indigo carmine dye appears useful for diagnosing early-stage GTC. Furthermore ESD represents a feasible alternative to conventional endoscopic mucosal resection as a minimally invasive therapy for early-stage GTC.

Visualization of Aneurysmal Neck and Dome after Coiling with 3D Multifusion Imaging of Silent MRA and FSE-MR Cisternography.

BACKGROUND AND PURPOSE: Our aim was to visualize the precise configuration of the aneurysmal neck and dome with/without remnants combined with a coiled dome after coiling treatment for cerebral aneurysms. We developed 3D multifusion imaging of silent MRA and FSE-MR cisternography. MATERIALS AND METHODS: We examined 12 patients with 3D multifusion imaging by composing 3D images reconstructed from TOF-MRA, silent MRA, and FSE-MR cisternography. The influence of magnetic susceptibility artifacts caused by metal materials affecting the configuration of the aneurysmal complex with coiling was assessed in a single 3D image. RESULTS: In all cases, TOF-MRA failed to depict the aneurysmal neck complex precisely due to metal artifacts, whereas silent MRA delineated the neck and parent arteries at the coiled regions without serious metal artifacts. FSE-MR cisternography depicted the shape of the coiled aneurysmal dome and parent artery complex together with the brain parenchyma. With the 3D multifusion images of silent MRA and FSE-MR cisternography, the morphologic status of the coiled neck and parent arteries was clearly visualized with the shape of the dome in a single 3D image. CONCLUSIONS: Silent MRA is a non-contrast-enhanced form of MRA. It depicts the coiled neck complex without serious metal artifacts. FSE-MR cisternography can delineate the shape of the coiled dome. In this small feasibility study, 3D multifusion imaging of silent MRA and FSE-MR cisternography allowed good visualization of key features of coiled aneurysms. This technique may be useful in the follow-up of coiled aneurysms.

Evaluation of combined docetaxel and nedaplatin chemotherapy for recurrent esophageal cancer compared with conventional chemotherapy using cisplatin and 5-fluorouracil: a retrospective study.

This retrospective study evaluated the safety and efficacy of combination chemotherapy using docetaxel and nedaplatin in an outpatient setting compared with those of chemotherapy using cisplatin (CDDP) and 5-Fu under hospitalization. Subjects comprised 21 patients who had been diagnosed with recurrent esophageal squamous cell carcinoma (ESCC), with 10 patients receiving combination chemotherapy comprising CDDP and 5-fluorouracil (5-Fu) under hospitalization (FP group; n = 10), and 11 patients receiving combination chemotherapy comprising docetaxel and nedaplatin in an outpatient setting (Doc/Ned group; n = 11). In the Doc/Ned group, patients received 30 mg/m(2) of docetaxel over a 1-h infusion on day 1, followed by 40 mg/m(2) of nedaplatin over a 2-h infusion on day 1 in an outpatient setting. In the Doc/Ned group, complete response was observed in two patients (18.1%), one with liver metastasis and one with abdominal lymph node metastasis, and two (18.1%) achieved partial response. In contrast, no complete responses were obtained in the FP group, and partial response was observed in only one patient (10.0%) with local recurrence. Response rates were thus 36.3% for the Doc/Ned group and 10.0% for the FP group. With a median follow-up of 234 days in the Doc/Ned group and 279 days in the FP group, median survival time (MST) was 234 days in the Doc/Ned group and 378 days in the FP group. No significant differences in MST were identified between groups. Thus regimen based on docetaxel and nedaplatin allows administration on an outpatient basis and appears feasible for recurrent ESCC as a second-line chemotherapy.

Effect of streptozotocin-induced diabetes on epidermal growth factor receptors in rat liver plasma membrane.

The effect of streptozotocin-induced diabetes on 125I-labeled epidermal growth factor (EGF) binding was studied in microsomal membranes from rat liver. The binding of EGF in membranes from diabetic animals was significantly low, the value being about 60% of the control level. Scatchard analysis of the binding data clearly showed that the decrease in EGF binding was due to a decrease in the number of receptors. Treatment of diabetic animals with insulin restored EGF receptors to control levels, whereas the treatment with triiodothyronine had no effect. Serum EGF concentrations measured were almost the same among the control, diabetic, and insulin-treated diabetic groups. These results suggest that insulin deficiency in vivo causes a decrease in hepatic EGF receptors.

Betaine prevents homocysteine-induced memory impairment via matrix metalloproteinase-9 in the frontal cortex.

Betaine plays important roles that include acting as a methyl donor and converting homocysteine (Hcy) to methionine. Elevated plasma Hcy levels are known as hyperhomocysteinemia (HHcy) and contribute to impairments of learning and memory. Although it is commonly known that betaine plays an important role in Hcy metabolism, the effects of betaine on Hcy-induced memory impairment have not been investigated. Previously, we demonstrated the beneficial effects of betaine on acute stress and lipopolysaccharide-induced memory impairment. In the present study, we investigated whether betaine ameliorates Hcy-induced memory impairment and the underlying mechanisms of this putative effect. Mice were treated with Hcy (0.162mg/kg, s.c.) twice a day for nine days, and betaine (25mg/kg, s.c.) was administered 30min before the Hcy injections. The memory functions were evaluated using a spontaneous alternation performance test (Y-maze) at seven days and a step-down type passive avoidance test (SD) at nine and ten days after Hcy injection. We found that betaine suppressed the memory impairment induced by repeated Hcy injections. However, the blood concentrations of Hcy were significantly increased in the Hcy-treated mice immediately after the passive avoidance test, and betaine did not prevent this increase. Furthermore, Hcy induces redox stress in part by activating matrix metalloproteinase-9 (MMP-9), which leads to BBB dysfunction. Therefore, we tested whether betaine affected MMP-9 activity. Interestingly, treatment with betaine significantly inhibited Hcy-induced MMP-9 activity in the frontal cortex but not in the hippocampus after acute Hcy injection. These results suggest that the changes in MMP-9 activity after betaine treatment might have been partially responsible for the amelioration of the memory deficits and that MMP-9 might be a candidate therapeutic target for HHcy.

Sex difference in epidermal growth factor receptor levels in rat liver plasma membrane.

The specific binding of [125I]epidermal growth factor [( 125I]EGF) to hepatic microsomal membranes was about 2-fold higher in adult male than in adult female rats. Scatchard analysis of the binding data showed that the sex difference in EGF binding was due to the difference in EGF receptor concentration rather than to a change in receptor affinity. From the developmental study, an apparent sex difference in EGF binding was observed from the pubertal period (4 weeks of age). Castration of adult male rats slightly, but significantly, decreased the EGF receptor level; and moreover, treatment of adult females with testosterone increased it only slightly. On the other hand, castration of neonatal male rats decreased the EGF receptor content almost to the female level. The decreased level of the receptor was completely restored by the combination of neonatal and pubertal treatments with testosterone. Neonatal or pubertal treatment alone of castrated animals had no significant effect on the decreased level of EGF receptors. These effects of testosterone were similarly observed when normal female rats were treated with the steroid. Moreover, hypophysectomy of the rats resulted in the marked decrease in EGF receptors only in the male animals. Treatment of hypophysectomized rats with either testosterone or T3 had no apparent effect on the EGF receptors. The membrane protein, cross-linked with [125I]EGF, had a mol wt of 170,000, and this protein (EGF receptor) was phosphorylated basally or by the addition of EGF. The rate of affinity labeling, or phosphorylation of EGF receptors, was in good agreement with the results of the EGF binding study. These results strongly suggest that the EGF receptor level in rat liver plasma membranes is in part regulated by the hypothalamopituitary unit and that neonatal androgens are essential for this regulation, probably through their effects on the hypothalamus.

Selective inhibition of type I collagen synthesis in osteoblastic cells by epidermal growth factor.

We have investigated the effect of epidermal growth factor (EGF) on collagen metabolism in clonal MC3T3-E1 cells, an osteoblastic cell line derived from newborn mouse calvaria. EGF significantly increased DNA synthesis, but decreased collagen production. We analyzed the amount of total collagen synthesis and degradation products of collagen together with the level of the enzyme responsible for extracellular collagen degradation, to investigate whether the decreased collagen production was due to a decrease in total collagen synthesis or to an increase in collagen degradation. Total collagen synthesis, determined by total hydroxyproline synthesized, was significantly decreased in cells cultured in medium containing EGF, but the amount of collagen degradation products and the level of animal collagenase activity were not increased. Analysis of the collagen type produced by the cells in the absence of EGF showed that 95% of the collagen recovered was type I and 3% was type III. The decreased level of collagen accumulated by cells cultured in the presence of EGF was explained only by the decreased rate of type I collagen synthesis. These results indicate that EGF selectively inhibits type I collagen synthesis in the clonal osteoblastic cell line, MC3T3-E1.

Effect of epidermal growth factor on collagen formation in liver-derived epithelial clone cells.

Biochemical and morphological studies were made on the effect of epidermal growth factor (EGF), isolated from male mouse submandibular gland, on collagen formation in clone RLC-18(4) epithelial cells from rat liver. EGF did not affect the number of these cells. EGF in the range of 0.5-500 ng/ml caused a dose-dependent increase in the content of hydroxyproline. It also increased the content of acidic glycosaminoglycans (AGAG), which are thought to be closely related to the formation of collagen fibers, and increased the activity of glutamine glucose-6-phosphate aminotransferase, an enzyme for AGAG synthesis but not that of N-acetyl-beta-glucosaminidase, an enzyme for AGAG degradation. It has no significant effect on the protein content of the cells. Studies on the effect of actinomycin D indicated that EGF may enhance de novo synthesis of hydroxyproline in liver epithelial cells and also that of glutamine glucose-6-phosphate aminotransferase, thus increasing the AGAG content of the cells. Antibody to EGF largely blocked collagen formation in the cells, even in the absence of EGF, indicating that EGF or EGF-like substances in the serum may affect collagen formation. In rat liver fibroblasts, EGF had little effect on collagen formation. These results show that EGF may act as a regulatory factor in collagen formation in liver epithelial cells, but not liver mesenchymal cells, in vitro.