Calcium polycarbophil, a water absorbing polymer, increases bowel movement and prevents sennoside-induced diarrhea in dogs

The effects of calcium polycarbophil (CP), a water-absorbing polymer, on bowel movement were examined in comparison with known laxatives and anti-diarrheal agents in dogs, a species that resembles humans for stool output. CP increased stool frequency, fecal water content and fecal weight in a dose-dependent manner, but did not induce diarrhea. Sennoside and carboxymethylcellulose sodium (CMC-Na) increased fecal water content and induced diarrhea at lower doses than that which enhanced stool frequency. Trimebutine decreased stool frequency, fecal weight and fecal water content, resulting in inhibition rather than stimulation of defecation. In sennoside-induced diarrhea, loperamide and CP improved stool consistency and this was accompanied by reduced fecal moisture and frequency of diarrhea. In contrast, CMC-Na aggravated stool consistency with increased fecal water content and frequency of diarrhea, and trimebutine had little noticeable effect apart from reducing fecal weight. Our results show that CP has both laxative and anti-diarrheal effects in dogs and differed from conventional laxatives and anti-diarrheal agents. CP may be a suitable agent for treatment of idiopathic constipation, secretory diarrhea and irritable bowel syndrome with alternating constipation and diarrhea and with either predominating in terms of less side effects such as diarrhea or constipation.

Structural basis for the anticoagulant activity of the thrombin-thrombomodulin complex

The serine proteinase alpha-thrombin causes blood clotting through proteolytic cleavage of fibrinogen and protease-activated receptors and amplifies its own generation by activating the essential clotting factors V and VIII. Thrombomodulin, a transmembrane thrombin receptor with six contiguous epidermal growth factor-like domains (TME1-6), profoundly alters the substrate specificity of thrombin from pro- to anticoagulant by activating protein C. Activated protein C then deactivates the coagulation cascade by degrading activated factors V and VIII. The thrombin-thrombomodulin complex inhibits fibrinolysis by activating the procarboxypeptidase thrombin-activatable fibrinolysis inhibitor. Here we present the 2.3 A crystal structure of human alpha-thrombin bound to the smallest thrombomodulin fragment required for full protein-C co-factor activity, TME456. The Y-shaped thrombomodulin fragment binds to thrombin's anion-binding exosite-I, preventing binding of procoagulant substrates. Thrombomodulin binding does not seem to induce marked allosteric structural rearrangements at the thrombin active site. Rather, docking of a protein C model to thrombin-TME456 indicates that TME45 may bind substrates in such a manner that their zymogen-activation cleavage sites are presented optimally to the unaltered thrombin active site.

Anti-ischemic effect of a novel cardioprotective agent, JTV519, is mediated through specific activation of delta-isoform of protein kinase C in rat ventricular myocardium

BACKGROUND

A new 1,4-benzothiazepine derivative, JTV519, has a strong protective effect against Ca(2+) overload-induced myocardial injury. We investigated the effect of JTV519 on ischemia/reperfusion injury in isolated rat hearts.

METHODS AND RESULTS

At 30 minutes of reperfusion after 30-minute global ischemia, the percent recovery of left ventricular developed pressure was improved, and the creatine phosphokinase and lactate dehydrogenase leakage was reduced in a concentration-dependent manner when JTV519 was administered in the coronary perfusate both at 5 minutes before the induction of ischemia and at the time of reperfusion. The myocardial protective effect of JTV519 was completely blocked by pretreatment of the heart with GF109203X, a specific protein kinase C (PKC) inhibitor. In contrast, the effect of JTV519 was not affected by alpha(1)-, A(1)-, and B(2)-receptor blockers that couple with PKC in the cardiomyocyte. Both immunofluorescence images and immunoblots of JTV519-treated left ventricular myocardium and isolated ventricular myocytes demonstrated that this agent induced concentration-dependent translocation of the delta-isoform but not the other isoforms of PKC to the plasma membrane.

CONCLUSIONS

The mechanism of cardioprotection by JTV519 against ischemia/reperfusion injury involves isozyme-specific PKC activation through a receptor-independent mechanism. This agent may provide a novel pharmacological approach for the treatment of patients with acute coronary diseases via a subcellular mechanism mimicking ischemic preconditioning.

Induction of Bcl-x(L) expression by human T-cell leukemia virus type 1 Tax through NF-kappaB in apoptosis-resistant T-cell transfectants with Tax

Human T-cell leukemia virus type 1 (HTLV-1) Tax is thought to play a pivotal role in immortalization of T cells. We have recently shown that the expression of Tax protected the mouse T-cell line CTLL-2 against apoptosis induced by interleukin-2 (IL-2) deprivation and converted its growth from being IL-2 dependent to being IL-2 independent. In this study, we demonstrate that constitutive expression of bcl-xl but not bcl-2, bcl-xs, bak, bad, or bax was associated with apoptosis resistance after IL-2 deprivation in CTLL-2 cells that expressed Tax. Transient-transfection assays showed that bcl-x promoter was transactivated by wild-type Tax. Similar effects were observed in mutant Tax retaining transactivating ability through NF-kappaB. Deletion or substitution of a putative NF-kappaB binding site identified in the bcl-x promoter significantly decreased Tax-induced transactivation. This NF-kappaB-like element was able to form a complex with NF-kappaB family proteins in vitro. Furthermore, Tax-induced transactivation of the bcl-x promoter was also diminished by the mutant IkappaBalpha, which specifically inhibits NF-kappaB activity. Our findings suggest that constitutive expression of Bcl-x(L) induced by Tax through the NF-kappaB pathway contributes to the inhibition of apoptosis in CTLL-2 cells after IL-2 deprivation.

The effect of tulobuterol tape on histamine-induced bronchoconstriction in conscious guinea pigs: long duration of action

The objective of the present study was to determine the action duration of tulobuterol tape within a 24-hr period in conscious guinea pigs. The bronchoconstriction induced by histamine-inhalation was significantly inhibited by tulobuterol tape in comparison with its placebo tape 8 and 12 hr after binding, and the inhibitory rate was 50+/-11% and 35+/-13%, respectively. Twenty-four hours after binding, the inhibitory effect of tulobuterol tape gradually diminished, but the inhibitory rate was maintained at 30+/-14%. These results suggest that tulobuterol tape has a long lasting bronchodilatory action.

Human T-cell leukemia virus type 1 tax protein abrogates interleukin-2 dependence in a mouse T-cell line

Human T-cell leukemia virus type 1 (HTLV-1) is the etiologic agent of adult T-cell leukemia. Tax, the viral protein, is thought to be crucial in the development of the disease, since it transforms healthy T cells in vitro and induces tumors in transgenic animals. We examined the effect of Tax activity on the growth of the interleukin-2 (IL-2)-dependent T-cell line CTLL-2. Stable expression of Tax in CTLL-2 transformed cell growth from being IL-2 dependent to IL-2 independent. Tax stimulated transcription through NF-kappaB and the cyclic AMP-responsive element-like sequence in the HTLV-1 promoter. The finding of Tax mutants segregating these two pathways suggested that the NF-kappaB pathway was essential for IL-2-independent growth of CTLL-2 cells while the CRE pathway was unnecessary. However, both pathways were necessary for another transformation-related activity (colony formation in soft agar) of CTLL-2/Tax. Our results show that Tax has at least two distinct activities on T cells, and suggest that Tax plays a crucial role in IL-2-independent T-cell transformation induced by HTLV-1, in addition to its well-known IL-2-dependent cell transformation.

Cardiac endothelin-1 plays a critical role in the functional deterioration of left ventricles during the transition from compensatory hypertrophy to congestive heart failure in salt-sensitive hypertensive rats

BACKGROUND

To investigate whether endogenous ET-1 participates in an adaptive process of left ventricular hypertrophy (LVH) or a maladaptive process from LVH to congestive heart failure (CHF), we used a Dahl salt-sensitive (DS) rat model, in which systemic hypertension caused compensated concentric LVH at the age of 11 weeks followed by marked LV dilatation and global hypokinesis at the age of 17 weeks.

METHODS AND RESULTS

By specific sandwich enzyme immunoassay, serum and myocardial ET-1 levels at the LVH stage were not elevated compared with age-matched Dahl salt-resistant (DR) rats, despite the marked increase of LV/body weight ratio (LV/BW). However, at the CHF stage, serum and LV ET-1 levels increased by 3. 8-fold and 5.4-fold, respectively. LV ET-1 contents had close relationships with the fractional shortening (r=0.763) and the systolic wall stress (r=0.858) measured by in vivo transthoracic echocardiography. Immunohistochemistry demonstrated that the remarkably increased ET-1 in LV is located mainly in cardiomyocytes. By competitive reverse transcriptase-polymerase chain reaction, LV prepro-ET-1 mRNA levels increased by 4.1-fold in CHF rats. We randomized 11-week-old LVH rats to chronic treatment with the endothelin receptor antagonist bosentan (Bos, 100 mg. kg-1. d-1, n=14), the alpha1-receptor antagonist doxazosin (Dox, 1 mg. kg-1. d-1, n=12), or vehicle (Cont, n=14). Bos treatment did not alter the LV geometry and function at 15 weeks; however, it attenuated the decrease of LV fractional shortening by 51% (P<0.01) without reducing the LV/BW at 17 weeks. Conversely, Dox, which decreased the blood pressure to the same extent as Bos, did not affect the progression of LV dysfunction. Bos (93%; P<0.0001 versus Cont) but not Dox (42%; P=0.8465 versus Cont) ameliorated the survival rate at 17 weeks (Cont; 36%).

CONCLUSIONS

The accelerated myocardial synthesis of ET-1 contributes directly to LV contractile dysfunction during the transition from LVH to CHF. Unelevated levels of LV ET-1 at the established LVH stage and lack of effects on LV mass by chronic bosentan treatment suggest that myocardial growth is mediated through alternative pathways. These studies indicate that chronic ET antagonism may provide an additional strategy for heart failure therapy in humans.

Scintigraphic measurement of regional gastrointestinal transit in the dog

Scintigraphic techniques can measure sequentially gastric emptying, small bowel transit, and colonic transit in humans, and comparable methods for experimental studies in animals would be useful. We developed such a method in dogs and examined the effects of prokinetic drugs on regional transit. Two isotopes were given to fasting dogs. Polystyrene pellets labeled with 99mTc were mixed in a can of dog food and 111In- labeled pellets were given in a gelatin capsule coated with a pH-sensitive polymer, designed to dissolve in the distal bowel. Gamma camera images were obtained for up to 24 h. Prokinetic drugs were given by intravenous injection. Duplicate baseline studies showed good agreement in seven dogs. In a second group (n = 4), intra- and interanimal variabilities were established. Two novel prokinetic drugs (AU-116 and AU-130) accelerated small bowel and colonic transit. A simple noninvasive method for measuring whole gut transit in dogs was developed and validated. Two new prokinetics accelerated small bowel and colonic transit.

Increased expression of interleukin-1 beta and monocyte chemotactic and activating factor/monocyte chemoattractant protein-1 in the hypertrophied and failing heart with pressure overload

Studies on the effects of proinflammatory cytokines on the heart suggest that they play some roles in the pathogenesis of congestive heart failure (CHF). To determine the involvement of proinflammatory cytokine in cardiac hypertrophy and CHF induced by mechanical overload, we investigated the expression of interleukin (IL)-1 beta and monocyte chemotactic and activating factor (MCAF)/monocyte chemoattractant protein-1 (MCP-1) in the left ventricle (LV) of Dahl salt-sensitive (DS) rats that showed hypertrophy of the LV induced by hypertension and subsequently developed CHF. The IL-1 beta mRNA content in the LV of DS rats increased 3.9-fold when LV hypertrophy developed, and the increase reached 6.2-fold at the CHF stage compared with that of age-matched Dahl salt-resistant (DR) rats. The amount of IL-1 beta in the LV was positively correlated with the LV weight/body weight ratio. Most of the IL-1 beta immunoreactivity was localized in the endothelial cells and interstitial macrophages. The mRNA levels of MCAF in the LV increased 3.6-fold at 11 weeks and reached 4.8-fold at the CHF stage relative to the age-matched DR rats. MCAF protein was localized to the endothelial cells and interstitial macrophages. In DS rats, the number of interstitial macrophages increased diffusely throughout the LV. We suggest that increased chemokine expression, macrophage infiltration, and proinflammatory cytokine expression play some role in the pathogenesis of cardiac hypertrophy and failure induced by chronic mechanical overload.

Mutational analysis of the 5' noncoding region of human immunodeficiency virus type 1 genome

Retrovirus particles are released by budding from the membranes of infected cells. In the course of virus production, particularly during the late stage, viral genomic RNA is incorporated specifically into virion particles. This specific incorporation of the genomic RNA requires a packaging signal sequence. A region that functions as the packaging signal was mapped to a location upstream of the gag open reading frame on the HIV-1 viral genome. In addition of this packaging signal, other cis-acting elements that are scattered throughout the genome are also required for efficient packaging. The region upstream of the splice donor site is probably important for dimer formation. Therefore, we focused on one region located between the 3' end of the primer binding site and the 5' splice donor site of HIV-1. Experiments were conducted to investigate how deletions or point mutations in this region affect both dimerization in vitro and the production of infectious virus particles. A series of RNAs of varying lengths containing the 5' noncoding region were generated, and genomic dimerization of the altered viral RNA was analyzed in vitro. One RNA construct which consisted of 112 nucleotides (nt) from nt 639 to nt 750 formed a heterodimeric complex with the RNA which consisted of 200 nucleotides from nt 551 to nt 750. We then constructed proviruses with mutations in the 639 to 750 nt region and assayed for virus production. Several mutants that lacked the complementarity necessary to form a possible stem-loop structure in this region showed decreased production of infectious virus particles. Moreover, both deletion of this region and randomization of its nucleotide sequence completely impaired infectious virus production. Thus, the way that this region affects infectious virus production may be through its RNA secondary structure.

Comparative studies on the antigenic structures of five subspecies of Oncomelania snails by immunoelectrophoresis

To approach the biochemical relationships of five subspecies of Oncomelania snails, antigenic structures among the subspecies were compared using immunoelectrophoresis. The results obtained are summarized as follows: 1) For five subspecies of Oncomelania hupensis snails (Oncomelania hupensis hupensis, O.h.nosophora, O.h. formosana, O.h. chiui and O.h. quadrasi), 23-24 precipitin bands were observed between the antigens and their homologous antisera, while 18-22 bands were observed in the heterologous reactions. 2) For each subspecies, residual bands observed after absorption procedure demonstrated the presence of antigens unique to each subspecies except O.h. chiui. Based on the immunological antigenic structures among the Oncomelania subspecies, it is suggested that O.h. nosophora and O.h. hupensis forms are closely related group, while O.h. formosana, O.h. chiui and O.h. quadrasi forms are another group.

Strain-gauge force transducer method for evaluating urethral motility in conscious dogs

A new method has been developed that is suitable for physiological studies of urethral motility in the conscious state with a strain-gauge force transducer (force transducer). In anesthetized dogs, the contractile or relaxing responses of the urethral smooth muscle in the direction of the circular layers measured with the force transducer, elicited by either phenylephrine or isoproterenol, were significantly correlated to the increase or decrease in the intra-urethral pressure (r = 0.998 and 0.780, respectively). In conscious dogs, the fluctuation in the urethral tone was observed to be less than in the intra-urethral pressure, and a dose-dependent response to phenylephrine (1-30 micrograms./kg. i.v.) and isoproterenol (0.1-3 micrograms./kg. i.v.) was clearly recognized. Moreover, this conscious model provided a fairly reproducible pattern with the urethral contraction or relaxation related to the filling or voiding phase of the cystometrogram, which was abolished by anesthetization. These results indicate that the present force transducer method makes it possible to evaluate the further physiological characteristics of urethral motility in conscious dogs.

Wild-type, but not mutant-type, p53 enhances nuclear accumulation of the NS3 protein of hepatitis C virus

By using vaccinia virus-T7 hybrid expression system, subcellular localization of the NS3 protein of hepatitis C virus was studied. Full-size NS3 (NS3F) and a carboxy-terminally truncated form (NS3 deltaC) were localized in the cytoplasm and the nucleus when expressed alone. However, NS3F and NS3 deltaC, but not amino- and carboxy-terminally truncated form (NS3 deltaN deltaC), were each co-localized with wild-type p53 almost exclusively in the nucleus upon co-expression. The wild-type p53-induced nuclear accumulation of NS3F was inhibited only partially by NS4A. When co-expressed with mutant-type p53, NS3F and NS3 deltaC were each co-localized with it exclusively in the cytoplasm. Taken together, the present results suggest that wild-type p53 enhances nuclear accumulation of NS3F and NS3 deltaC through the involvement of their amino-terminal sequences even in the presence of NS4A, and that mutant-type p53 inhibits their nuclear, and enhances their cytoplasmic, accumulation.

Gastroprokinetic effect of a new benzamide derivative itopride and its action mechanisms in conscious dogs

The novel benzamide derivative itopride was assayed for its effect on gastrointestinal motility in conscious dogs when it was administered intraduodenally (i.d.). Gastrointestinal motility was measured by means of chronically implanted force transducers, and itopride at a dose of 10 mg/kg, i.d. or more increased the gastric contractile force during the digestive state. Intraduodenal cisapride, domperidone and metoclopramide also stimulated gastric motility, and their threshold doses were 1, 3 and 1 mg/kg, respectively. Dopamine infusion (1 mg/kg/hr, i.v.) caused the postprandial gastric motility to disappear, but it was immediately restored by itopride at a dose of 3 mg/kg, i.d. With itopride at 1 and 3 mg/kg, i.d., acetylcholine (0.05 mg/kg/min)-induced contractions were greatly enhanced. In addition to its gastric stimulation, itopride at doses of 10-100 mg/kg, p.o. inhibited apomorphine (0.1 mg/kg, s.c.)-induced vomiting in dogs. In conclusion, intraduodenal itopride stimulates gastric motility through both anti-dopaminergic and anti-acetylcholinesterase actions. Its gastroprokinetic threshold dose was as large as 3-10 times those of cisapride, domperidone and metoclopramide. These findings suggest that itopride is an orally active gastroprokinetic with a moderate anti-emetic action.

Experimental infection of five subspecies of Oncomelania snails with Angiostrongylus cantonensis

Five subspecies of Oncomelania snails, Oncomelania hupensis nosophora, O.h. hupensis, O.h.chiui, O.h.formosana and O.h.quadrasi, were experimentally exposed to the first stage larvae of Angiostrongylus cantonesis. The presence of third stage larvae was observed in all of the five subspecies of Oncomelania snails 20 days after infection. Infection rates of the third stage larvae of the parasite in Oncomelania snails were 38.0-40.0%. There were no differences in preferences among Oncomelania snails. The third stage larvae in Oncomelania snails almost distributed in kidney and intestine region, and most of the larvae were active and free in tissues. The distribution pattern of the larvae in Oncomelania snails was quite different from that in Achatina fulica and Ampullarium sp. These third stage larvae were ingested by rats, and developed to adults. These data suggest that Oncomelania snails may play important role when A. cantonensis will spread, and indicate the possibility of human infection with A. cantonensis.

[A case of successful treatment of chronic sternal osteomyelitis and mediastinitis after ascending aorta and hemiarch reconstruction]

Mediastinitis is one of severe and fatal complications after cardiac surgery, especially in the presence of a prosthetic graft. A 70-year-old male, who was suffered from chronic sternal osteomyelitis and mediastinitis after ascending aorta and hemiarch reconstruction was reported. He developed high fever and leucocytosis on the 16th postoperative day. Wound culture was positive for Grampositive organisms. He was diagnosed as having sternal osteomyelitis and mediastinitis and treated by sternal bone debridement and irrigation with dilute povidone iodine solution with no effects. Total excision of the infected sternum, irrigation with non-diluted solution of povidone iodine and omental transfer were performed successfully. The literature regarding omental transfer for mediastinitis and infected prosthetic grafts was briefly reviewed.

Characterization of acetylcholinesterase-inhibition by itopride

Itopride is a gastroprokinetic benzamide derivative. This agent inhibited both electric eel acetylcholinesterase (AChE) and horse serum butyrylcholinesterase (BuChE). The IC50 of itopride with AChE (2.04 +/- 0.27 microM) was, however, 100-fold less than that with BuChE, whereas in the case of neostigmine with AChE (11.3 +/- 3.4 nM), it was 10-fold less. The recovery of AChE activity inhibited by 10(-7) M neostigmine was partial, but that inhibited by up to 3 x 10(-5) M itopride was complete when the reaction mixture was subjected to ultrafiltration. Double reciprocal plots of the experimental data showed that both Km and Vmax were affected by itopride, suggesting that the inhibition is a "mixed" type, although primarily being an uncompetitive one. The inhibitory effect of itopride on cholinesterase (ChE) activity in guinea pig gastrointestine was much weaker than that on pure AChE. However, in the presence of a low dose of diisopropyl fluorophosphate, just enough to inhibit BuChE but not AChE, the IC50s of itopride against ChE activities were found to be about 0.5 microM. In conclusion, itopride exerts reversible and a "mixed" type of inhibition preferably against AChE. The IC50 of itopride for electric eel and guinea pig gastrointestinal AChE inhibition was 200 times and 50 times as large as that of neostigmine, respectively.

[A case of bronchogenic cyst at the anterior chest wall]

Bronchogenic cyst in the subcutaneous region is rare and only 5 cases including this case have been reported in Japan. A 2-year-old boy was admitted to our hospital because of congenital mass at the anterior chest wall. Ultrasonography showed a 29 x 9 mm sized well-defined tumor with homogeneous low echogenicity in the subcutaneous tissue. Extirpation of the tumor was performed. Histologically, ciliated columnar epithelia with the surrounding smooth muscle and seromucous glands were observed. Diagnosis of bronchogenic cyst was made. Postoperative course was uneventful and no tumor has recurred.

Effects of substance P on gastric motility differ depending on the sites and vagal innervation in conscious dogs

The effect of substance P on gastric motility was studied in conscious dogs by means of strain gauge force transducers chronically implanted on the gastric body, antrum, and a vagally-denervated fundic pouch. Intravenous infusion of substance P in the interdigestive state induced phasic contractions in the pouch and antrum. Atropine inhibited these contractions in the pouch and antrum. Hexamethonium enhanced substance P-induced contractions in the gastric antrum, but reduced those in the pouch. Pretreatment with phentolamine, propranolol, or naloxone did not affect substance P-induced contractions in the pouch and antrum. The intact gastric body scarcely reacted to substance P. Mean systemic blood pressure was lowered by substance P-infusion, but there was no dose-dependency in the reduction of the blood pressure, nor was it affected by the pretreatment with atropine or hexamethonium. These results suggest that 1) the vagal innervation influences the effect of substance P on motility in the gastric body, and that 2) substance P may stimulate postsynaptic excitatory cholinergic and presynaptic inhibitory neurons simultaneously in the gastric antrum.

Studies on host-parasite relationship between the Puerto Rican strain of Schistosoma mansoni and Biomphalaria snails

Immunoelectrophoretic studies on common antigenicities were carried out by using rabbits sera immunized with the Puerto Rican strain of Schistosoma mansoni adult worms or eggs and antigens of several adult Biomphalaria snails and vice versa. As the result, S. mansoni adult worm extracts produced 8 bands both with extracts of Biomphalaria glabrata pigmentation and B. glabrata pigmentado, 3 to 4 bands with those of B. glabrata albino and 1 to 2 bands with those of B. straminea. On the other hand, S. mansoni egg extracts produced 5 bands with extracts of B. glabrata pigmentation, 4 bands with those of B. glabrata pigmentado, 2 bands with those of B. glabrata albino and 1 band with those of B. straminea. In the experimental infection of adult Biomphalaria snails with five S. mansoni miracidia, the infection rate in B. glabrata pigmentation was 78.8%, and 71.2% in B. glabrata pigmentado, whereas the infection rate in B. glabrata albino was 10.3%, and B. straminea was not susceptible to S. mansoni. The infectivity of each snail corresponded with the number of bands representing common antigenicities between host and parasite. Crude antigens of Biomphalaria snails were fractionated by Sephadex G-100 column, and each antigen fraction was tested with anti-S. mansoni adult worm and egg sera by immunoelectrophoresis. The common antigenicities between fractionated antigens of Biomphalaria snails and of ani-S. mansoni adult worm or egg sera mostly existed in the first fraction 1 with Mr > 45 kDa.

[A case of mediastinal emphysema due to blunt trauma that a continuous drainage to the extrapleural space took effect]

A 70-year-old male was admitted to our hospital with chest bruise, resulting in fracture of the right rib. Nine hours later, the patient came to use again with a chief complaint of dyspnea and chest oppression. He had extensive subcutaneous emphysema in the upper half of the body. Chest X-ray films revealed remarkable mediastinal emphysema and collapse in a part of right lung. Chest CT scan disclosed enlargement of extrapleural cavity. These findings suggested progression of mediastinal emphysema. Continuous drainage to the extrapleural cavity was performed and the clinical course was uneventful. Thus, a satisfactory result can be obtained by extrapleural drainage in a patient with severe mediastinal emphysema.

Curatively resected primary malignant melanoma of the esophagus: report of a case

We report herein a rare case of primary esophageal malignant melanoma in a 49-year-old Japanese woman who presented with a 3-week history of dysphagia. Esophagogram and esophagoscopy demonstrated a polypoid tumor in the upper to mid-thoracic portion of the esophagus, and a radical subtotal esophagectomy was performed through a right thoracotomy. Histological and immunohistochemical studies proved this tumor to be a primary esophageal malignant melanoma. She received no postoperative adjuvant therapy and no signs of recurrence have been clinically observed for the 22 months since her operation.