[Three patients with spontaneous pneumomediastinum, including one in whom pneumomediastinum recurred]

We encountered three patients with spontaneous pneumomediastinum. All three (two men and one woman) were previously healthy. They complained of chest pain or dyspnea. On admission, physical examination revealed subcutaneous emphysema. Chest roentgenograms and computed tomograms revealed pneumomediastinum and subcutaneous emphysema. All other findings were normal. All patients were treated with bed rest and all recovered in 7 to 9 days. Pneumomediastinum recurred in one patient after 20 months.

Up-regulation of high-affinity dehydroepiandrosterone binding activity by dehydroepiandrosterone in activated human T lymphocytes

Although evidence indicates that dehydroepiandrosterone (DHEA) exerts direct physiological effects, its mechanism of action remains unknown. DHEA binding sites were examined using a whole-cell binding assay in a human T lymphoid cell line, PEER, revealing that a single class of high-affinity binding sites for DHEA (dissociation constant = 7.4 +/- 0.53 nmol/L, mean +/- SE, n = 4) was greatly increased when treated with DHEA, phorbol-12-myristate-13-acetate, and the Ca2+ ionophore A23187. Bound [3H]DHEA was displaced sensitively by DHEA and secondarily by dihydrotestosterone, but not effectively by other steroids, including DHEA sulfate. These results not only indicate the existence of a DHEA receptor, but also suggest that T cells become susceptible to regulation by DHEA during the process of signal-induced activation.

Effect of the microtubule-disrupting drug colchicine on rat cerulein-induced pancreatitis in comparison with the microtubule stabilizer taxol

Effects of colchicine, a microtubule-disrupting agent, on rate exocrine pancreas were examined in comparison with the microtubule stabilizer Taxol for the purpose of analyzing the pathogenesis of cerulein-induced acute pancreatitis. Taxol ameliorated the inhibition of pancreatic secretion, elevation of serum amylase level, pancreatic edema, and histological alterations induced by supramaximal cerulein stimulation. In contrast, colchicine by itself and colchicine followed by cerulein stimulation (maximal and supramaximal) inhibited pancreatic secretion but did not induce the hyperamylasemia, pancreatic edema, or formation of large vacuoles, which characterized cerulein-induced pancreatitis. Electron microscopic studies in the colchicine-treated rats revealed that transport vesicles were accumulated in the supranuclear region and that no large vacuoles were observed in the apical lesion. Immunofluorescence studies confirmed that colchicine inhibited pancreatic secretion and disrupted the arrangement of microtubules. Posttreatment of colchicine did not prevent the development of cerulein-induced pancreatitis. Vinblastine, another microtubule-disrupting drug, as well as colchicine, inhibited pancreatic secretion but did not induce acute pancreatitis. The results obtained in this study suggest that microtubule disorganization at a specific step in the process of intracellular vesicular transport causes cerulein-induced pancreatitis and that this step is more apical than that at which colchicine inhibits secretion in the pancreatic acinar cell.

The first observation of O2- generation at real time in vivo from non-Kupffer sinusoidal cells in perfused rat liver during acute ethanol intoxication

Infusion of ethanol or phorbol myristate acetate (PMA) into the perfused rat liver immediately produces O2- which was detected directly by infusion of a Cypridina luciferin analogue, MCLA as a chemiluminescence reagent. The MCLA photon emission was inhibitable by SOD. Generation of O2- in the liver was further verified by nitroblue tetrazolium, formazan precipitate formation. Ethanol-induced O2- generation was unaffected by gadolinium chloride (GdCl3), an inhibitor of kupffer cells, while PMA induced O2- generation was completely abolished by GdCl3. Since PMA is a known stimulator of phagocytic cells including Kupffer cells, the results indicate, for the first time that ethanol stimulates a non-Kupffer cell population, probably liver sinusoid endothelial cell to produce O2-.

IL-2-induced gene expression of protein-tyrosine phosphatase LC-PTP requires acidic and serine-rich regions within IL-2 receptor beta chain

A protein-tyrosine phosphatase LC-PTP is preferentially expressed in hematopoietic cells and is an early response gene in lymphokine stimulated cells. Here, we found the LC-PTP mRNA induction by IL-2 was markedly inhibited by several tyrosine kinase inhibitors. The induction required both the acidic and serine-rich regions of the IL-2 receptor beta chain (IL-2R beta) in mouse IL-3-dependent pro-B BAF-B03 transfectants. This is strikingly different from the induction of c-myc gene expression, which requires the serine-rich region alone. In addition, overexpression of activated-Lck or -Raf kinases resulted in augmented LC-PTP mRNA expression in myeloid cell line 32D transfectants. Considering the previous findings that the acidic region of the IL-2R beta is responsible for association with Lck and activation of Raf kinase, IL-2-induced expression of LC-PTP mRNA may be primarily transduced through a Lck-Raf mediated signaling pathway.

Motility related protein 1 (MRP-1/CD9) expression: inverse correlation with metastases in breast cancer

In our previous studies we showed that motility related protein 1 (MRP-1) is a glycoprotein recognized by mAb M31-15, and that the sequence of MRP-1 is identical to that of CD9, a WBC differentiation antigen. Transfection of MRP-1/CD9 cDNA into cultured nonhematopoietic cells suppresses cell motility. The extent of suppression is directly related to the level of MRP-1/CD9 expression. In addition, the metastatic potential of MRP-1/CD9-transfected melanoma BL6 cells is lower than that of control BL6 cells. To determine whether these experimental results are of relevance with respect to actual human tumors, we investigated MRP-1/CD9 expression in 143 invasive ductal carcinomas of the breast. Of 97 patients with MRP-1/CD9-positive tumors, only 36 (37.1%) had lymph node involvement. In contrast, 21 of 39 (53.8%) patients whose tumors had reduced MRP-1/CD9 immunoreactivity and 5 of 7 patients whose primary carcinomas were not stained by the anti-MRP-1/CD9 MAb had lymph node metastases. The comparison of protein expression by 62 primary tumors and their respective metastatic lymph nodes revealed that in almost 50% of the cases, the latter had lower MRP-1/CD9 levels than the former. Moreover, reverse transcriptase-PCR-based analysis disclosed that MRP-1/CD9 gene expression in the metastatic lymph nodes of 17 of 32 patients was strikingly lower than in the primary invasive ductal carcinomas. Gene overexpression was not observed in any of the samples studied. Our data suggest that low MRP-1/CD9 expression may be associated with the metastatic potential of certain human tumors.

Effect of sympathectomy on inotropic responsiveness to alpha-adrenoceptor stimulation in developing mouse myocardia

Effects of postnatal sympathectomy on inotropic responsiveness to alpha-adrenoceptor stimulation were examined in mouse myocardia to determine whether the developmental conversion of alpha-adrenoceptor-mediated inotropic responses from positive to negative is triggered by sympathetic innervation. Sympathectomy was performed chemically by consecutively administering 6-hydroxydopamine for 14 days after birth and confirmed by the absence of inotropic responses to tyramine. In newborn myocardia, phenylephrine, in the presence of propranolol, produced concentration-dependent positive inotropic responses. Three weeks after birth, phenylephrine, in the presence of propranolol, produced concentration-dependent negative inotropic responses, both in control and in sympathectomized myocardia; no difference was observed between the two groups of mice in the maximum decrease in contractile force produced by phenylephrine. The sensitivity (pD2 value) to phenylephrine was significantly higher in sympathectomized myocardia. In conclusion, sympathetic innervation of the mouse ventricular myocardium is not required for the developmental conversion of the alpha-adrenoceptor-mediated inotropic response from positive to negative.

Induction by 5-aza-2'-deoxycytidine, an inhibitor of DNA methylation, of Le(y) antigen, apoptosis and differentiation in human lung cancer cells

We recently developed a monoclonal antibody directed to carbohydrate antigen Le(y), BM-1/JIMRO, and found that expression of Le(y) antigen defined by BM-1/JIMRO was associated with the process of apoptosis, but not with cell proliferation or necrosis. In the present experiments, we examined with BM-1/JIMRO the effects of various differentiation inducers on the growth and expression of Le(y) antigen in human lung cancer A549 cells. We found that a specific inhibitor of methylation of DNA, 5-aza-2' deoxycytidine (ADC), could markedly induce expression of Le(y) antigen in association with induction of apoptosis and differentiation in the A549 cells. These results suggest that hypomethylation of DNA is involved in the molecular mechanisms of induction of Le(y) antigen, apoptosis and differentiation in the cells.

Characterization and gene cloning of 1,3-beta-D-glucan synthase from Saccharomyces cerevisiae

1,3-beta-D-Glucan synthase of Saccharomyces cerevisiae was solubilized and purified up to 700-fold by product entrapment. The specific activity of the partially purified enzyme was around 4 mumol glucose incorporated.min-1.mg protein-1. In SDS/PAGE, enrichment of a 200-kDa protein was clearly observed in parallel with the increase in specific activity. mAbs that could immunoprecipitate the 1,3-beta-D-glucan synthase activity were isolated, and some of them also recognized this 200-kDa protein in the Western blot. Internal amino acid sequences of this 200-kDa protein were determined after lysyl endopeptidase digestion. With the information of these amino acid sequences, we cloned two genes, GSC1 and GSC2 (glucan synthase of S. cerevisiae 1 and 2), which are very similar to each other (88% at the amino acid level); hydropathy profiles of both proteins suggest that these genes encode integral membrane proteins which can be assumed to have approximately 16 transmembrane domains. Disruption of each gene was not lethal, but disruption of both genes was lethal. The 1,3-beta-D-glucan synthase activities of membrane and partially purified enzyme of gsc1::URA3 cells were significantly lower than those of the wild-type and gsc2::LEU2 cells.

Hypertrophic cranial pachymeningitis with spinal epidural granulomatous lesion

A 67-year-old woman with a one-year history of tinnitus and headache had multiple cranial nerve palsies of V, VII, VIII, IX, X, XI and spastic paraparesis. She also had a secretory otitis media. Gd-DTPA-enhanced magnetic resonance imaging (MRI) revealed hypertrophy of the dura of the posterior fossa and spinal epidural mass which extended from C7 to T10. A biopsy of the epidural mass showed chronic granulomatous change. These lesions were completely cured with administration of antibiotics. We believe this case of double-lesion of hypertrophic cranial pachymeningitis and spinal epidural granulomatous lesion originated from a bacterial infection secondary to the secretory otitis media.

[RANTES expression on human bronchial epithelial cells]

Viral infection induces airway inflammation. It is possible that bronchial epithelium derived chemokine contributes to the migration and accumulation of inflammatory cells in the airway viral infection. We infected bronchial epithelial cells with influenza virus and analysed mRNA expression and production of RANTES. The expression of mRNA and the production of RANTES were detected in infected cells using RT-PCR method and ELISA.

Ligand binding domain of the human endothelin-B subtype receptor

We have employed both protein chemical and molecular biological approaches to determine the ligand binding domain of the endothelin-B subtype (ETB) receptor. The human ETB receptor purified from human placenta by using affinity chromatography was cross-linked with 125I-labeled endothelin-1 (ET-1) and then incubated in the presence of trypsin or thermolysin under nondenaturing conditions. The N-terminal amino acid sequence of the radiolabeled polypeptide encompassed approximately 115 amino acid residues starting from Ile85 of the human ETB receptor. This was confirmed by experiments in which the binding activity of endothelin-1 to various chimeric endothelin receptors was monitored in the presence and absence of competitive endothelin receptor antagonists such as BQ-123 and bosentan. The region from Ile138 to Ile197 (60 amino acid residues) of the ETB receptor was found to interact with both antagonists. Therefore, this sequence was determined to be the ligand binding domain. In addition, we found that part of the N-terminal domain in close proximity to the first transmembrane region was required for the ligand binding activity of the ETB receptor, and the 12 amino acid residues from Ser390 to Leu401 at the proximal cytoplasmic tail are perhaps necessary to maintain the ligand binding site in active form. The cysteine rich region from residue 400 to residue 403 in the C-terminus of the ETB receptor is involved in coupling of the guanine nucleotide-binding regulatory protein for ET-1-induced signal transduction.

Hepatocyte growth factor as a hematopoietic regulator

Hepatocyte growth factor (HGF) was originally isolated as a mitogen for adult hepatocytes, but this cytokine is now regarded as a multi-functional factor. In the present study, we show that the mouse liver in the middle and/or late stage of the fetal life expresses both HGF and c-met (its receptor) messages. HGF and c-met mRNA are coexpressed not only in the adherent layers of fetal liver long-term cultures (FL-LTCs) and adult bone marrow long-term cultures (BM-LTCs), but also in the stromal cell lines MS-5 and PA-6. Addition of human HGF (2 and 20 ng/mL) to the LTCs enhances (1) nonadherent cell counts (ninefold in FL-LTCs and sixfold in BM-LTCs), (2) nonadherent colony-forming unit-in culture (CFU-C) counts (eightfold in FL-LTCs and fivefold in BM-LTC), and (3) cobblestone colony counts. However, HGF slightly inhibits the proliferation of stromal cells. No direct effect of HGF on freshly isolated BM and/or FL cells is found in the CFU-C assay. However, an approximately 1.5-fold synergistic increase in CFU-C counts is noted when the BM or FL cells are cocultured with HGF in the presence of interleukin-3. These findings strongly suggest that HGF plays a crucial role as a hematopoietic regulator in the proliferation and differentiation of hematopoietic progenitors.

[The effect of flumazenil in reversing midazolam, flunitrazepam or diazepam]

In 31 adult patients who had undergone spinal or epidural anesthesia, we evaluated the effect of flumazenil in reversing midazolam, flunitrazepam or diazepam. The patients received midazolam 5 mg, flunitrazepam 1 mg or diazepam 5 mg 15 min after the spinal or epidural anesthesia. After the completion of operation, flumazenil (0.2 mg-1.0 mg) was administered until the patient became awake. Blood pressure, pulse rate and respiratory rate before and after administration of flumazenil showed no statistically significant changes in these groups. There were no significant differences in necessary amount of flumazenil among these groups. The time necessary for the patient to be awake in midazolam group was significantly shorter than that in flunitrazepam or diazepam group. Half of the patients in flunitrazepam and diazepam groups slept again after leaving the operating room, but they presented no clinical problems. In conclusion, we consider that flumazenil does not affect circulation and respiration, so it seems to be safe and effective for reversing benzodiazepins in clinical situation.

[MR imaging of temporomandibular joint (TMJ): mandibular fracture and traumatic disk injury]

Using an 1.5 Tesla superconducting MR unit and surface coil, 12 mandibular fracture patients were evaluated for TMJ disk change. Sagittal and coronal images of the TMJ with a slice thickness of 2mm were obtained with FISP 2D or 3D. TR = 30 msec, TE = 12 msec, and flip angle = 40 degrees were applied. Among 12 patients, FISP 3D revealed increased signal intensity of the disk in 70% of cases. Traumatic fluid collection at or adjacent to the TMJ showed high intensity. The disk was displaced anteromedially regardless of the site of fracture.

Characteristics of antitumor activity of 3,4-dihydro-6-[4-(3,4-dimethoxybenzoyl)-1-piperazinyl]- 2(1H)-quinolinone (vesnarinone) against a human adenoid squamous carcinoma-forming cell line grown in athymic nude mice

The tumors produced by transplantation into nude mice of human adenoid squamous carcinoma-forming cell line TYS, presumably derived from a minor salivary gland, were treated with a differentiation-inducing agent, vesnarinone, which was given per o.s. daily at a dose of 200 mg/kg for 35 days. They were then examined morphologically and immunohistochemically. The vesnarinone treatment resulted in a significant suppression of tumor growth. In addition, tumor nests indicating keratinocyte and acinar cell differentiation were often observed in the treated tumors, but not in untreated controls. Tissue sections from vesnarinone-treated and untreated TYS tumors were stained with monoclonal antibody (NAb) directed to carbohydrate antigen LeY or proliferating cell nuclear antigen (PCNA) and with rabbit polyclonal antibody to p53. Antibody staining patterns were compared with morphological characteristics of cells as revealed by hematoxylin and eosin staining, and DNA fragmentation patterns as revealed by 3'-OH nick-end labelling techniques. Tissue sections from vesnarinone-treated TYS tumors showed positive reaction with nick-end labelling and were extensively stained strongly by anti-LeY MAb, whereas the untreated tumors showed negative reaction with nick-end labelling and were infrequently stained by anti-LeY MAb. Within LeY-positive areas of tissue sections from the vesnarinone-treated tumors, keratinocyte and acinar cell differentiation as well as DNA fragmentation were frequently observed, although not all LeY-positive cells showed such signs of apoptosis. LeY-positive cells showed consistent negative staining by anti-PCNA MAb and anti-p53 rabbit serum. From these findings, it can be considered that vesnarinone has differentiation and apoptosis-inducing activity against TYS cells grown in athymic nude mouse.

Association of nbl gene expression and glucocorticoid-induced apoptosis in mouse thymus in vivo

A gene of unknown biological function, nbl, was originally isolated by virtue of its abundance in a Namalwa Burkitt Lymphoma cDNA library. nbl expression was initially found to be higher in tissues which exhibited internucleosomal DNA cleavage characteristic of apoptosis, than in tissues which did not exhibit a 'DNA ladder'. nbl expression was therefore examined in mouse thymus in vivo, in which apoptosis is induced by the glucocorticoid, dexamethasone. nbl expression was markedly enhanced by dexamethasone treatment and then sharply decreased prior to the occurrence of maximal 'DNA ladder' formation. In contrast, expression of myc, which is believed to be involved in apoptosis in other cell systems, declined as thymic apoptosis increased. Thymic apoptosis was blocked by the transcriptional inhibitor actinomycin D, if administered when nbl expression was enhanced, but not before or after the peak of nbl expression. These results suggest that nbl expression is associated with thymic apoptosis.

Granulocytapheresis as a possible cancer treatment

We assessed the effect of granulocyte apheresis in patients exhibiting increased granulocyte-to-lymphocyte ratio in order to overcome granulocytosis occurring in the terminal stages of malignancies. 17 patients with post-operative recurrent metastatic tumors including 6 gastric, 3 colonic, 2 rectal, 1 esophageal and 5 breast cancers were selected. The granulocytapheresis was performed by extracorporeal vein-to-vein circulation equipped with an apheresis column filled with cellulose acetate beads. Each week the patients underwent one or two sessions of treatment that lasted 30 to 50 minutes per session at a flow rate of 30 to 50 ml/min. 15 sessions formed 1 therapeutic cycle. The effect of granulocytapheresis resulted in partial response (PR) in 4 cases, no change (NC) in 7 cases and partial disease (PD) in 6 cases. The performance status showed 30% remission. None of the patients exhibited significant side effects. Since the treatment demonstrated anti-tumor effects, granulocytapheresis may be applied during combined cancer treatments.

[Examination on aspirin-induced asthma and hypersensitivity to steroids--a questionnaire to 850 asthma on hypersensitivity to non-steroidal anti-inflammatory drugs and hypersensitivity to steroids]

We surveyed 850 patients with bronchial asthma and investigated such clinical features as the frequency of aspirin-induced asthma and hypersensitivity to steroids in the 457 available answers. We divided them into two groups, one was ASN: the asthmatics who had history of hypersensitivity to non-steroidal anti-inflammatory drugs, another was non-ASN: the asthmatics who had no history of hypersensitivity to non-steroidal anti-inflammatory drugs, and compared the two groups. The survey showed that the frequency of ASN was 12.0%. Its frequency rose with the severity of asthma to a level of 29.0% in severe cases. In ASN it was more frequent rates of female, infectious type, severe cases, and ASN had more frequent histories of oral use of steroids, use of ambulance, treatment in emergency rooms, and hospitalization than non-ASN. The serum IgE level was lower in ASN. The patients were 6 in ASN, none in non-ASN who had histories of hypersensitivity to steroids. They were 1.3% in all patients. 5 of 6 had past asthma attack progressived severely by rapid injection of succinate ester steroids and 2 of 6 had past by rapid injection of phosphoric acid ester steroids. In conclusion it was considered that we had to avoid rapid injection of steroids to aspirin-induced asthma and severe cases who were doubtful of aspirin-induced asthma in case of treatment of asthma attack.

Apoptosis as a mechanism of skin renewal: Le(y)-antigen expression is involved in an early event of a cell's commitment to apoptosis

Skin renewal is a typical example of the active participation of a cell in its own death process. Cells arising from mitotic activity in the stratum germinativum of the epidermis continuously migrate upwards to the stratum corneum, where dead cells are eventually desquamated. Recent studies have suggested that apoptosis is involved in the dynamic process of skin renewal. However, this still remains to be further elucidated. In this paper, we investigated the involvement of apoptosis in the skin renewal process. Changes in the morphology of cells in different epidermal layers were compared with histochemical analyses of the extent of DNA fragmentation, as determined by nick end-labelling, and of the reactivities to a monoclonal antibody directed to Le(y)-antigen, difucosylated type 2 chain determinant, which has a close association with apoptosis, and to a monoclonal antibody directed to the proliferating cell nuclear antigen. The results show that apoptosis proceeds concomitantly with cell movement in the epidermis. It seems likely that commitment of a cell to death by apoptosis occurs in the epidermal tissue immediately after completion of cell proliferation, and that Le(y)-antigen expression may be involved in the entire apoptotic process including this early event.

Effect of IPD-1151T (Suplatast Tosilate) on airway hyperresponsiveness in mice

We investigated the effect of IPD-1151T (Suplatast Tosilate, (+/-)-[2-[4-(3-ethoxy-2-hydroxypropoxy) phenyl-carbamoyl]-ethyl] dimethylsulfonium p-toluenesulfonate) against allergic bronchoconstriction induced by allergen and methacholine (MCh).BALB/c mice were sensitized by intraperitoneal injection of 0.5 microgram of keyhold limpet hemocyanin mixed with Al(OH)3. IPD-1151T was administered orally once a day for 5 or 14 days in doses of 10, 30 or 100 mg/kg body weight. Bronchoconstriction was measured 24 hrs after the final drug administration. IPD-1151T inhibited both antigen-mediated allergic bronchoconstriction and induction of bronchial hyperresponsiveness after sensitization or allergen challenge in actively sensitized mice. The degree of inhibition was proportional to the dose and frequency of oral administration of the agent.

Immunohistochemical features of HLA-DR antigen expression and lymphoid infiltrates in gastric carcinoma after low-dose interleukin-2 and mitomycin C

We immunohistochemically evaluated lymphoid cell infiltration and HLA-DR antigen expression in gastric tumor tissue obtained from advanced gastric cancer patients 1 day after the completion of the treatment with mitomycin C (MMC) 12 mg/m2 i.v. on day 1 and recombinant interleukin-2 (IL-2) i.v. every 12 h from day 4 through day 8. Then the results were compared with those in 11 patients pretreated with MMC alone, 5 treated with IL-2 alone, and 24 untreated patients. Widespread lymphoid infiltration was observed in 17% of untreated tumors, 27% of MMC-pretreated tumors, and 40% of tumors treated with IL-2 alone. However, 71% of carcinomas pretreated with MMC plus IL-2 exhibited widespread infiltration. The frequency of cases with high-grade infiltration of CD4+ cells was significantly higher in either group of patients treated with MMC alone or MMC plus IL-2. Because the CD8+ cell infiltration was not significantly altered, the ratio of CD4+ to CD8+ cells estimated as being > 1 was more frequently noted in patients given MMC alone or MMC plus IL-2, as compared with untreated control. Furthermore, 86% of tumors pretreated with MMC plus IL-2 exhibited positive HLA-DR antigen expression, whereas 29% of untreated carcinomas did so. MMC or IL-2 alone did not significantly increase HLA-DR expression. These results indicate that the combination of low-dose of IL-2 with MMC enhances the intensity of lymphoid cell infiltration in tumors, with the predominance of CD4+ cells, and HLA-DR antigen expression on tumor cells in patients with advanced gastric carcinoma.

[Statistical analysis of press-through-pack foreign body in the esophagus and its experimental investigation]

A statistical analysis was performed in patients with press-through-pack (PTP) foreign body in the esophagus encountered in the Department of Otorhinolaryngology, Tohoku University School of Medicine, from 1986 to 1993. Furthermore, the radiolucency of PTP and the possibility of mucosal injury of the esophagus by PTP were examined by experimental methods. We obtained the following results: 1) The incidence of PTP foreign body in the esophagus increased in the period from 1986 to 1994 as compared with that from 1978 to 1985. 2) PTP foreign body was lodged in the following area: cricopharyngeal narrowing > bronchio-aortic narrowing > hiatal narrowing. 3) Fluoroscopy with or without contrast material and flexible endoscopy were useful tools for diagnosis. 4) Direct esophagoscopy revealed mucosal erosion, hematoma, edema and intact mucosa in 14, 3, 3, and 6 patients, respectively. 5) The period of hospitalization was longer in patients with mucosal erosion than in those with intact mucosa. 6) The base of PTP made of aluminium could be detected as a radiopaque material by lateral projections, suggesting that PTP foreign bodies require roentgenograms made parallel to the base of PTP. 7) Histological study indicated that traumatic lesions in the extracted esophagus manually produced by the sharp corner of PTP were present in the mucosal layer and partially in the submucosal layer, suggesting that esophageal perforation by PTP was generated by additional factors such as secondary infection and iatrogenic trauma induced by esophagoscopy.