Photoluminescence from exciton-polarons in GaGdN/AlGaN multiquantum wells

Exciton-polaron formation in GaGdN/AlGaN multiquantum wells was inferred from the lower energy of the photoluminescence peak observed for the GaGdN quantum wells (QWs) compared with GaN QWs. The rather low value of the excitonic transition energy is attributed to exciton-polarons bound to the Gd ions. Exciton-polarons are most likely to occur due to the lattice distortion around the substituted Gd ions in addition to the exchange interaction between Gd(3+) magnetic ions and the strongly confined charge carrier spins in GaGdN QWs. The mechanism of exciton-polaron formation is discussed. The magnetic behavior is briefly presented.

Deepwater formation in the North Pacific during the Last Glacial Termination

Between approximately 17,500 and 15,000 years ago, the Atlantic meridional overturning circulation weakened substantially in response to meltwater discharges from disintegrating Northern Hemispheric glacial ice sheets. The global effects of this reorganization of poleward heat flow in the North Atlantic extended to Antarctica and the North Pacific. Here we present evidence from North Pacific paleo surface proxy data, a compilation of marine radiocarbon age ventilation records, and global climate model simulations to suggest that during the early stages of the Last Glacial Termination, deep water extending to a depth of approximately 2500 to 3000 meters was formed in the North Pacific. A switch of deepwater formation between the North Atlantic and the North Pacific played a key role in regulating poleward oceanic heat transport during the Last Glacial Termination.

Formation of aligned CrN nanoclusters in Cr-delta-doped GaN

Cr-delta-doped GaN layers were grown by radio-frequency plasma-assisted molecular-beam epitaxy on GaN template substrates. Cr flux was supplied without nitrogen flow during Cr-delta-doping. Cr incorporation into a narrow thin layer region was confirmed with the depth profile measured by secondary ion mass spectrometry. Structural properties and Cr atom alignments were studied with transmission electron microscopy. It was found that Cr-delta-doped GaN layers were coherently grown with Cr or CrGa nanoclusters in the delta-doped region for low temperature growth (350, 500 °C). It was also found that aligned CrN nanoclusters (approximately 5 nm vertical thickness) with NaCl-type structure were formed in the delta-doped region for the growth at 700 °C.

A novel endoscopic marker: safety experiments in the rat stomach

BACKGROUND AND STUDY AIMS

The study aimed to assess a newly developed endoscopic marker designed to cause only minor inflammatory reactions.

MATERIALS AND METHODS

Chitosan and carbon powder were used in the marker substance. The product was a viscoelastic solution, which was injected into the submucosa in rat stomach walls. The tissue reactions were then examined histopathologically. The structure of the injected marker substance was examined with electron microscopy into rat stomach walls. India ink, which is currently used as an endoscopic marker, served as the control.

RESULTS

Histopathological examination showed that inflammatory reactions with the novel agent were remarkably mild in the rat organs, while submucosally applied india ink caused severe inflammation in situ. The electron-microscopic findings showed that the carbon particles used were completely spherical in shape and that the carbon in the marker substance was entrapped in the chitosan networks. The india ink was shown to consist of a mixture of fine carbon particles and adhesive additives.

CONCLUSIONS

The chitosan-carbon solution appears to be a promising endoscopic marker substance, causing significantly reduced inflammation.

Immunohistochemical detection of the 150-kDa oxygen-regulated protein in bladder cancer

OBJECTIVE

To investigate the relationship between the expression of the 150-kDa oxygen-regulated protein (ORP150, which functions as a molecular chaperone in the endoplasmic reticulum for the folding and trafficking of newly synthesized proteins) and the aggressiveness of bladder cancer, and the expression of vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMPs), as the former is a secreting protein through the endoplasmic reticulum and the latter are closely involved in tumour invasion.

MATERIALS AND METHODS

Thirty-nine cystectomy specimens, comprising 12 superficial (pT1) and 27 invasive (pT2-pT4) tumours, were immunohistochemically analysed using antibodies against ORP150, VEGF, MMP-1, MMP-2 and MMP-9. Staining was scored from 0 to 3, according to the ratio of positively staining cells.

RESULTS

Staining was positive (score 1-3) for ORP150 in 10 of 12 superficial and 25 (93%) of the invasive tumours, with a significantly higher staining score for stage T4 than stage T1 tumours. The trend was the same for the staining score of MMP-2, and there was a significant correlation between ORP150 and MMP-2 expression.

CONCLUSIONS

The expression of ORP150 was common in bladder cancer, with a tendency for greater expression in higher stages. The significant correlation between ORP150 and MMP-2 expression suggests that ORP150 acts as a molecular chaperone for MMP-2 secretion and thus tumour invasion.

The identification and characterization of new immunogenic egg components: implications for evaluation and control of the immunopathogenic T cell response in schistosomiasis

In schistosomiasis, granuloma formation to parasite eggs signals the beginning of a chronic and potentially life-threatening disease. Granulomas are strictly mediated by CD4+ T helper (Th) cells specific for egg antigens; however, the number and identity of these T cell-sensitizing molecules are largely unknown. We have used monoclonal T cell reagents derived from egg-sensitized individuals as probes to track down, isolate and positively identify several egg antigens; this approach implicitly assures that the molecules of interest are T cell immunogens and, hence, potentially pathogenic. The best studied and most abundant egg component is the Sm-p40 antigen. Sm-p40 and its peptide 234-246 elicit a strikingly immunodominant Th-1-polarized response in C3H and CBA mice, which are H-2k strains characterized by severe egg-induced immunopathology. Two additional recently described T cell-sensitizing egg antigens are Schistosoma mansoni phosphoenolpyruvate carboxykinase (Sm-PEPCK) and thioredoxin peroxidase-1 (Sm-TPx-1). In contrast to Sm-p40, both of these molecules induce a more balanced Th-1/Th-2 response, and are relatively stronger antigens in C57BL/6 mice, which develop smaller egg granulomas. Importantly, Sm-p40 and Sm-PEPCK have demonstrated immunogenicity in humans. The findings in the murine model introduce the important notion that egg antigens can vary significantly in immunogenicity according to the host's genetic background. A better knowledge of the principal immunogenic egg components is necessary to determine whether the immune responses to certain antigens can serve as indicators or predictors of the form and severity of clinical disease, and to ascertain whether such responses can be manipulated for the purpose of reducing pathology.

[Novel biodegradable materials for drug delivery systems (DDS)]

The authors provide three new and different types of fibrin gels (FCs) and a chitosan sheet (BC) using an ultraviolet (UV)-crosslinking method. They are 1) FC-UV, 2) gelatin entrapped FC; FC (Gp)-UV, 3) chitosan entrapped FC; FC (Cs)-UV and 4) BC-UV. Each material was loaded with aqueous cis-platinum (CDDP), and both the degradation of the drug carriers and the release profile of the CDDP were examined in vitro. The FCs, 1)-3), gradually degraded and dissolved within 10-12 days. The BC, 4), maintained its original weight for more than 30 days. Each FC showed a sustained release of CDDP for 10 days, while BC provided an initial bursting of the loaded drug. New materials 2) and 3) show great potential as drug carriers for DDS and further in vivo studies are now proceeding.

Transient spontaneous regression of aggressive non-Hodgkin's lymphoma confined to the adrenal glands

A 72-year-old-man with night sweats and a low-grade fever was found to have bilateral adrenal enlargement associated with incipient adrenal insufficiency. Without any intervention, these adrenal lesions regressed spontaneously, accompanied by disappearance of clinical symptoms. Seven months later, however, the lesions became enlarged and exceeded their initial size while remaining confined to the adrenals, associated with reappearance of nights sweats and overt adrenal insufficiency. Upon unilateral laparoscopic adrenalectomy, the lesion proved histopathologically to be diffuse large B cell non-Hodgkin's lymphoma (NHL). After contralateral laparoscopic adrenalectomy and adjuvant chemotherapy, the patient remains alive with no recurrence at 26 months. Treatment with bilateral adrenalectomy and chemotherapy is effective for aggressive NHL confined to bilateral adrenal glands. A transient clinical improvement without treatment was considered to be due to a spontaneous regression of NHL, although we could not confirm the histological results before the regression. Such tumor behavior showing spontaneous regression in spite of aggressive histology may also be related to the favorable outcome, even though regression was transient.

[A case of plasmacytoma involving adrenal gland]

We report a case of extramedullary plasmacytoma involving the right adrenal gland. A 52-year-old male was introduced under diagnosis of right adrenal tumor which was found incidentally by computerized tomography in a health check up. Laboratory data showed the presence of M protein and elevation of monoclonal lambda type IgG. It was a hormonally non-active tumor involving the adrenal area. Extramedullary plasmacytoma was confirmed by histological analysis of the resected specimen after laparoscopic right adrenalectomy. Extramedullary plasmacytoma is an uncommon neoplasm and occurs most frequently in the upper respiratory tract and is fairly rare in the adrenal area.

Endoscopic subtotal thyroidectomy for patients with Graves' disease

Endoscopic thyroidectomy performed via the precordial approach leaves no scarring of the neck, and thus provided excellent results from a cosmetic viewpoint. We applied this technique to perform subtotal thyroidectomy in 12 patients with Graves' disease. Three trocars were inserted in the precordial region, and endoscopic surgery was performed with carbon dioxide insufflation. Vessel management and thyroidectomy were carried out using ultrasonic coagulation devices. The mean operative time was 259.8 min, and the mean blood loss was 90.2ml. There were no postoperative complications such as subcutaneous emphysema or hemorrhage, although hypoparathyroidism and recurrent laryngeal nerve paralysis occurred in one patient. Cosmetically esthetic results were achieved in all patients. These findings indicate that this surgical technique represents an effective method of treating Graves' disease that provides excellent cosmetic results.

Schistosome infection stimulates host CD4(+) T helper cell and B-cell responses against a novel egg antigen, thioredoxin peroxidase

Egg granuloma formation during schistosome infections is mediated by CD4(+) T helper (Th) cells sensitized to egg antigens; however, most of the relevant sensitizing egg antigens are still unknown. Here we show that schistosome thioredoxin peroxidase (TPx)-1 is a novel T- and B-cell egg antigen in schistosome-infected mice. CD4(+) Th cell responses to fractionated egg components identified a significant response against a 26-kDa antigen; a partial amino acid sequence of this antigen was found to be identical to that of Schistosoma mansoni TPx-1. The native TPx-1 elicited significant proliferative responses as well as gamma interferon (IFN-gamma), interleukin-2 (IL-2), IL-4, and IL-5 secretion in CD4(+) cells from 8.5-week-infected CBA and C57BL/6 mice. By comparison, recombinant TPx-1 elicited a smaller, more type 1-polarized response, with significant production of IFN-gamma and IL-2, less IL-5, and essentially no IL-4. In C57BL/6 mice the responses to TPx-1 were relatively more prominent than that directed against the major egg antigen, Sm-p40, whereas in CBA mice the reverse was true. B-cell responses were also monitored in infected C57BL/6, C3H, CBA, and BALB/c mice. All strains had significant antibody levels against the TPx-1 protein, but the most significant antibody production ensued following parasite oviposition. TPx-1 was localized in eggs and shown to be secreted by eggs. The identification of egg antigens is important to understand the specific basis of granuloma formation in schistosome infections and may prove to be useful in strategies to ameliorate pathological responses.

[A novel fibrin clot with a sustained release of cis-platinum (CDDP)]

The authors devised a novel fibrin clot (FC) using an ultra-violet (UV)-crosslinking method. CDDP was impregnated into FCs, and the release profiles of the CDDP were examined in vitro. The microstructures of the FCs were studied with scanning electron microscopy (SEM). The release of CDDP from the FC-UV-CDDP was maintained for 10 days, while that from the FC-CDDP showed initial bursting with a following plateau of CDDP concentrations. SEM of UV-crosslinked FCs revealed highly organized, close and homogeneous micropore structures. Native FCs and non-crosslinked FCs showed rough fibrin networks with entangling fibrin fibers. These microstructural differences may play important roles in the release profiles of CDDP. Our newly devised UV-crosslinked material is promising as a drug carrier for sustained release.

Schistosoma mansoni phosphoenolpyruvate carboxykinase, a novel egg antigen: immunological properties of the recombinant protein and identification of a T-cell epitope

In schistosomiasis mansoni, hepatic granulomatous inflammation surrounding parasite eggs is mediated by CD4(+) T helper (Th) cells sensitized to schistosomal egg antigens (SEA). We previously showed that a prominent lymphoproliferative response of CD4(+) Th cells from schistosome-infected C57BL/6 (BL/6) mice was directed against a 62-kDa component of SEA. A partial amino acid sequence of the 62-kDa component was found to be identical with one present in the enzyme phosphoenolpyruvate carboxykinase (PEPCK). Based on this sequence, a cDNA clone containing the entire coding region of PEPCK was identified, and the full recombinant Schistosoma mansoni PEPCK (rSm-PEPCK) of 626 amino acids was purified from a prokaryotic expression system. rSm-PEPCK strongly stimulated a specific T-cell hybridoma, 4E6, as well as CD4(+) Th cells from SEA-immunized BL/6 mice and from infected BL/6, CBA, and BALB/c mice. In the infected mice, rSm-PEPCK elicited significant gamma interferon production as well as, to a lesser extent, production of interleukin-2 and -5. In BL/6 and BALB/c mice, the CD4(+) Th cell response to rSm-PEPCK was greater than that directed against the egg antigen Sm-p40; conversely, CBA mice responded better to Sm-p40 than to Sm-PEPCK. A 12-amino-acid region (residues 398 to 409: DKSKDPKAHPNS) was demonstrated to contain a T-cell epitope; synthetic peptides containing this epitope significantly stimulated specific hybridoma 4E6 and polyclonal CD4(+) Th cells. The identification and characterization of immunogenic egg components will contribute to the understanding and possible control of T-cell-mediated schistosomal disease.

[A case of chromophobe cell renal carcinoma]

We report a case of chromophobe cell renal carcinoma. A 27-year-old male suffered from right flank pain and gross hematuria. Drip infusion pyelography and ultrasonographic examination revealed a right renal mass and it was diagnosed as renal oncocytoma by needle biopsy of the right kidney. He was referred to our hospital for the operation and right radical nephrectomy was performed. The cut surface of the tumor was beige in color. The cytoplasm of the tumor cells stained positively for colloidal iron and showed a negative reaction for Vimentin. From these results, this tumor was given a diagnosis of chromophobe cell renal carcinoma.

A novel 62-kilodalton egg antigen from Schistosoma mansoni induces a potent CD4(+) T helper cell response in the C57BL/6 mouse

In infection with Schistosoma mansoni, hepatic granuloma formation is mediated by CD4(+) T helper (Th) cells sensitized to schistosomal egg antigens. There is considerable variation among infected individuals with respect to both severity of disease and the T-cell response to egg antigens. In the BL/6 mouse, the egg granulomas are relatively small and the relevant sensitizing egg antigens are largely unknown. We investigated the CD4(+) Th cell response of infected BL/6 mice to egg antigens fractionated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and found a prominent lymphoproliferative response to be directed against a 62-kDa component. With the aid of a specific T-cell hybridoma, 4E6, the 62-kDa antigen was isolated; following partial digestion with endoproteinase Glu-C, an internal amino acid sequence was found to be identical with one present in the enzyme phosphoenolpyruvate carboxykinase (PEPCK) of the organisms Caenorhabditis elegans and Treponema pallidum and to differ by one residue from PEPCK of various other species. In CD4(+) Th cells from 7.5- 8.5-week-infected BL/6 mice, the purified 62-kDa molecule elicited a potent proliferative response which, based on cytokine analysis, was of a mixed Th-1 and Th-2 type. Our results reveal a novel egg antigen of particular prominence in the BL/6 mouse and suggest that the immune response in schistosomiasis is a product of sensitization to egg antigens that may vary considerably in immunogenicity from strain to strain.

[Occult gallbladder disease or microlithiasis in patients with acute pancreatitis: a frequent clinical event]

BACKGROUND

Patients with acute pancreatitis (AP) and a normal gallbladder by standard echographic evaluation may have "occult" gallbladder disease or microlithiasis with recurrent episodes of AP.

AIM

To conduct a prospective evaluation of patients with the diagnosis of non-biliary AP in order to detect "occult" gallbladder disease and to compare its clinical presentation with that of biliary AP.

PATIENTS AND METHODS

Patients admitted with the diagnosis of AP to a clinical hospital were included in the study. According to an abdominal ultrasound study, patients were classified as having or not cholelithiasis. A duodenal biliary drainage was performed in 15 patients with AP and without gallbladder stones.

RESULTS

Patients without cholelithiasis had recurrent AP more often than patients with biliary AP (53 and 3.3% respectively). Excessive alcohol ingestion did not rule out the possibility of biliary etiology. In 6 patients, the analysis of duodenal bile showed cholesterol crystals, and cholecystectomy confirmed the existence of gallbladder disease in 5. All of them remained asymptomatic during a follow-up period of four years. One patient refused surgery, with subsequent development of gallstones and recurrent episodes of AP. In other 4 patients, gallbladder disease was confirmed by percutaneous gallbladder puncture or during cholecystectomy. No recurrence of AP were observed during the follow-up

CONCLUSIONS

Microlithiasis or "occult" gallbladder disease accounts for at least 67% of the original "non-biliary" AP. Duodenal bile analysis is a useful and necessary technique for the evaluation of patients with "non-biliary" acute pancreatitis. Careful clinical and echographic follow-up of this subgroup of patients with AP is mandatory.

Hypoxanthine: a low molecular weight factor essential for growth of erythrocytic Plasmodium falciparum in a serum-free medium

A low molecular weight factor in a basal medium essential for erythrocytic Plasmodium falciparum development in a serum-free medium using a cell growth-promoting factor derived from adult bovine serum was detected. The factor was hypoxanthine. The optimal hypoxanthine concentration for parasite growth was between 15 and 120 microM. The contribution of hypoxanthine to increased parasite growth was clearly evident in cultures on day 4. Among various low molecular weight supplements tested, adenine, adenosine, AMP, ATP, cyclic AMP, guanine, guanosine, inosine, inosine monophosphate, xanthine, NAD, NADH, NADP, NADPH and deoxyguanosine triphosphate showed a similar effect to that of hypoxanthine in the serum-free culture system. On the other hand, the addition of uric acid, FAD, thymidine, uridine, orotic acid, deoxythymidine triphosphate, deoxycytidine triphosphate, deoxyadenosine triphosphate, ribose-1-phosphate, or ethanolamine was not beneficial to the parasite growth. The results presented here will not only be of practical value, but will provide important information about the developmental requirements of the parasite.

[A pharyngeal carcinoma after resection of a upper esophageal web]

Dysphagia suddenly progressed in a 69-year-old woman who had a 50-year history of intermittent difficulty in swallowing solid food. A thick circumferential who in the upper esophagus was extensive enough to be the cause of dysphagia. There was another thin semicircular web in the pharynx. Bouginage resulted in only 6-months relief of symptoms, and the same esophageal who was reformed with the same severe symptoms 3 years later. Surgical resection of the esophageal web was performed. Extensive pharyngeal carcinoma was found 4 years after surgery. She died of heart failure during combination therapy of irradiation and chemotherapy.

Continuous cultivation of intraerythrocytic Plasmodium falciparum in a serum-free medium with the use of a growth-promoting factor

Serum-free media were used to culture Plasmodium falciparum. A commercial preparation, Daigo's GF21 developed as a growth-promoting factor for many kinds of mammalian cells, and consisting of the 55-70% ammonium sulphate fraction of adult bovine serum, insulin, transferrin, ethanolamine and sodium selenite, was found to sustain growth of the parasite when Daigo's T was employed as a basal medium. The optimal Daigo's GF21 concentration for parasite growth was between 5 and 20% (v/v), with the best results at 10%. Differential counts indicated that Daigo's GF21 is essential for schizogony. Established serum-free medium, GIT, consisting of Daigo's T basal medium and Daigo's GF21, yielded good parasite growth without any supplementation. Growth-promoting factor derived from adult bovine serum in Daigo's GF21 was shown to be crucial to parasite growth. The results presented here will not only be of practical value, but will provide important information about the developmental requirements for the parasite.

[Changes of cytokine levels in ascitic fluid after intraperitoneal administration of OK-432 or CDDP]

In order to evaluate the biological response after intraperitoneal administration of OK-432 and CDDP, we studied the changes of cytokine levels in ascitic fluid. A total of 53 gastric cancer patients were included in this study. OK-432 20KE was administered in 7 patients and CDDP was administered in 4 patients intraperitoneally during operation. The IL-6, IL-8, TNF-alpha and sTNF RI levels in ascitic fluid were measured from 0 to 5 postoperative day. These results were compared with those obtained from the control groups (42 patients). The ascitic level of IL-6 increased immediately after operation, then gradually decreased. The elevations of IL-6 from 0 to 5 postoperative day were remarkably higher in the OK-432 treated group, and those on 0 and 1 postoperative days were remarkably lower in CDDP treated group than in the control group. Similarly, the ascitic level of IL-8 elevated soon after operation and then decreased gradually. In the OK-432 treated group, the ascitic level of IL-8 was significantly higher than in the control group from 0 to 2 postoperative day. Ascitic TNF-alpha was detectable only in the ascites soon after operation in the OK-432 treated group. The ascitic level of sTNF RI peaked on 2 postoperative day in the control and the OK-432 treated group and 1 postoperative day in the CDDP treated group. There were no significant differences between these groups.

Epidemiological survey of dementia and depression among the aged living in the community in Japan

The authors surveyed the prevalence of depression and dementia in the elderly in Ohira town in Japan from 1989 to 1990. The total population of this town was 26,712, with 2,778 people aged 65 and above, constituting 10.4% of the total population. The prevalence of dementia (n = 128) was 6.1% and that of major depression (n = 9) was 0.4%, according to the DSM-III-R criteria. The prevalence of a depressive state which did not fulfill the criteria for major depression (n = 55) was 2.4%. The patients with multi-infarct dementia (n = 49) suffered from depression (42.8%) more frequently than those with dementia of the Alzheimer type (11.1%). The rate of depression coexisting with dementia increased with aging, while the rate of depression without dementia did not change in all the age groups.

Arginine-dependent generation of reactive nitrogen intermediates is instrumental in the in vitro killing of protoscoleces of Echinococcus multilocularis by activated macrophages

The interaction between protoscoleces of Echinococcus multilocularis and activated murine macrophages was examined in this study. Marked protoscolicidal activity was displayed by peritoneal macrophages (PM) activated with interferon-gamma (IFN-gamma), or IFN-gamma plus lipopolysaccharide. Pretreatment of the parasites with heat-inactivated specific murine infection serum, but not with normal serum rendered them more susceptible to PM killing. NG-monomethyl-L-arginine, a competitive inhibitor of L-arginine completely inhibited the killing activity of activated PM, while reconstitution of arginine-free medium with L-arginine restored the killing properties of the activated PM. The results show that activated PM have the ability to kill E. multilocularis protoscoleces in vitro and suggest that reactive nitrogen intermediates (RNI) play an important role in the mechanism. An oxygen-mediated mechanism did not appear to play a role because scavengers of reactive oxygen species did not reduce the killing activity. The arginine-dependent killing mechanism was enhanced by superoxide dismutase (SOD), probably because SOD might prolong the effect of nitric oxide. Secretion of RNI by activated macrophages may be capable of a significant role in preventing of the dissemination of E. multilocularis infection in vivo.

[Changes in cytokine levels in ascitic fluid after intraperitoneal administration of OK-432]

In order to evaluate the biological response after intraperitoneal administration of OK-432, we studied the changes of cytokine levels in ascitic fluid. In 6 advanced gastric cancer patients with peritoneal dissemination or extensive lymph node metastases, OK-432 20 KE was administered intraperitoneally during operation and the IL-6, IL-8 and IFN-gamma levels in ascitic fluid were measured from 0 to 5 postoperative days. These results were compared with those obtained from non-OK-432 administered control groups (17 cases). The ascitic level of IL-8 increased immediately after operation and gradually decreased. In the OK-432 treated group, the elevation of IL-8 on 0 and 1 postoperative days was remarkable, and there were statistically significant differences with the control group. Similarly, the ascitic level of IL-6 elevated soon after operation and then decreased gradually. In the OK-432 treated group, the ascitic level of IL-6 was significantly higher than in the control group after 3 postoperative days. There were no differences in changes of ascitic IFN-gamma levels between the groups. From these results, IL-6 and IL-8 appeared to be induced in ascitic fluid by intraperitoneal administration of OK-432.

[Role of oxygen radicals in the pathogenesis of acute gastric mucosal lesion under obstructive jaundice]

In this study we examined the role of oxygen-derived free radicals in the pathogenesis of acute gastric mucosal lesion induced by obstructive jaundice in rats. Rats were divided into 4 groups as follows: control (sham operation), jaundiced (ligation and dissection of bile duct), vagotomized (truncal vagotomy), and vagotomized with jaundice group. The water immersion restraint procedure was performed. The water immersion restraint procedure was performed. The results obtained are as follows: jaundiced group showed significant increase of ulcer index (UI) and significant decrease of gastric mucosal blood flow (GMBF) and gastric mucosal potential difference (PD). However, intragastric pH (pH) was unchanged compared to the control group. Oxygen radical generating system (gastric mucosal XOD activity and thiobarbiturate acid) and oxygen radical scavenging system (gastric mucosal SOD activity and GSH-px activity) were higher than those of control group. Vagotomized group showed significant increase of pH compared to the control group. Oxygen generating system and scavenging system were unchanged compared to the control group. Vagotomized with jaundice group showed depression of UI and improvement of oxygen radical generating system and scavenging system. However GMBF, PD nad pH were unchanged compared to the jaundiced group. These results suggest that oxygen radical play some role in the development of acute gastric mucosal lesion induced by obstructive jaundice.

Regulation of the human T-cell response to Schistosoma japonicum egg antigen by concomitant cellular and humoral mechanisms in vitro

Serum-mediated regulation of T-cell responses specific for soluble egg antigen (SEA) of Schistosoma japonicum was tested in human hosts. When we added autologous serum to SEA-specific human T-cell lines (CD3+, 4+, 8-), we observed suppression of T-cell proliferation, and this suppressive activity was detected in the immunoglobulin-G2 (IgG2) subclass. Suppression was dose-dependent and antigen-specific. T-cell proliferation induced by only one SEA fraction of greater than 18 kDa was modulated in the presence of 100 micrograms/ml autologous as well as allogeneic infected IgG2. This SEA fraction-driven proliferation was also regulated by suppressor T-cells through distinct suppressive mechanisms. Our results suggest that T-cell responses to a particular component(s) of SEA are strictly regulated through both cellular and humoral mechanisms in human chronic S. japonicum infection.

Biological nature of Cryptosporidium sp. isolated from a cat

A small type of Cryptosporidium oocysts was isolated from a naturally infected cat and its biological nature was investigated. In cats experimentally inoculated with Cryptosporidium oocysts, long-lasting shedding of the oocysts occurred after a prepatent period of 8-10 days, and a number of peaks of oocyst count appeared at intervals of several days to a few weeks, earlier in the infection course. Cryptosporidium infection in cats is likely to pass from an acute to a chronic stage. During the chronic stage, prednisolone injection into the cats gave rise to a recurrence of proliferation of the parasite along with a marked increase in the number of oocysts shed. None of the infected cats showed clinical symptoms. Infection experiments using Cryptosporidium oocysts were unsuccessful in several species of animals such as mice, rats, guinea pigs, dogs, suckling mice and mice previously injected with prednisolone or hydrocortisone.

Prevalence of Cryptosporidium infection among domestic cats in the Tokyo Metropolitan District, Japan

From February, 1988 to February, 1989, an epidemiological survey for feline cryptosporidiosis was carried out on domestic cats that had been committed to the Tokyo Metropolitan Animal Protection Center by owners residing in the Tokyo Metropolitan District. Of a total of 608 cats, 23 (3.8%) were found to have Cryptosporidium oocysts. The percentage of cats positive for the infection ranged from 0 to 13.6% by month. The infection was found to be more common in "baby" and "young" cats than in "middle" and "old" ones. No significant difference in incidence was shown between the sexes. In each positive cat, no apparent clinical symptom such as diarrhea was found, and the size of the oocysts measured from 4.3 to 4.7 microns in diameter (small type).

A simple staining method for cryptosporidian oocysts and sporozoites

A useful staining method for detection of cryptosporidian oocysts and sporozoites was developed and described. The modified Kohn's one-step staining technique with an additional modification, i.e., longer staining time and higher staining temperature than those originally described, was tested on fecal smears from cats infected with Cryptosporidium sp. By this improved staining procedure, the oocyst appeared as a slightly oval body containing four internal sporozoites colored blue to blue-gray. The oocyst wall was stained dark green to black. The morphological feature of the oocyst was recognized much more clearly by this staining technique than by such currently used techniques as acid-fast and Giemsa staining. This staining procedure proved to be simple and less costly and to secure a good preservation.

Life cycle of Tritrichomonas muris

Morphological and physiological studies were carried out on a flagellate, Tritrichomonas muris, in golden hamsters. The experiments confirmed that a pseudocyst and an intermediate form exist in addition to the trophozoite in the life cycle; furthermore it was shown that the pseudocyst was the infective stage, and that a true cyst did not occur.

Recovery from immunesuppression in mice infected with Schistosoma japonicum by treatment of praziquantel

To learn the possible alteration of immune response, hemolytic plaque-forming cells (PFC) produced in the spleen of Schistosoma japonicum infected mice treated with Praziquantel and untreated group were counted. There was no significant difference in the immunesuppression percentage between the treated and untreated groups 1 and 3 weeks after treatment. In 5 weeks after treatment, however, the immunesuppression percentage in the treated mice was markedly reduced in comparison with that of the untreated group. Recovery from immunesuppression appears to be associated with elimination or impairment of adult worms.

Cytotoxic factors toward neuroblastoma cells in trypomastigotes of Trypanosoma cruzi

Homogenates of trypomastigotes of Trypanosoma cruzi (T.c) exhibited low-potency cytotoxic activity toward neuroblastoma cells. The cytotoxic activity was markedly decreased after preservation for 1 week, even at -20 degrees C. Trypsin and pronase E were shown to effectively enhance or restore the cytotoxic activity of T.c by producing some alteration in T.c, depending on concentrations of and treatment time with the enzymes. The cytotoxic factors were insoluble in saline and found in the chloroform extracts of a T.c homogenate. Analysis by thin-layer chromatography showed that the cytotoxic activity of T.c was found in the free fatty acids and lysophospholipids fractions. Of the free fatty acids present in T.c, eicosatetraenoic (20:4) and octadecadienoic (18:2) acids were the most cytotoxic. It was assumed that as much as 27.2% (w/w) of the total lipids of T.c consists of free fatty acids, and 1 mg of protein of the T.c homogenate contains 96 micrograms of free fatty acids. The abundant free fatty acids appear to account for the cytotoxic activity of the T.c homogenate, although they occurred in T.c under weakly active condition.

[Double primary malignant neoplasm of renal cell carcinoma and stomach cancer: report of two cases]

Two cases of double primary malignant neoplasm of renal cell carcinoma and gastric cancer are presented. Case 1 was a 59-year-old woman with right renal cell carcinoma (granular cell subtype) and gastric cancer (poorly differentiated adenocarcinoma). Case 2 was a 72-year-old man with left renal cell carcinoma (clear cell carcinoma) and gastric cancer (tubular adenocarcinoma). In both cases, the occult blood reactions of stool was strong and clear gastrointestinal symptoms developed. In these 2 cases of synchronous double cancer, gastrectomy following nephrectomy was performed in the same operation.

Characteristics of the anti-sheep red blood cell heterophile antibodies produced during Schistosoma japonicum infection in mice

Heterophile antibodies (Ab) against sheep red blood cells were shown to have developed in mice experimentally infected with Schistosoma japonicum (SJ). Incidence of the elevated Ab levels was markedly high in the period of 6-10 weeks following infection. By means of absorption tests, the heterophile Ab could be distinguished from classical human heterophile Ab of Paul-Bunnell, Hanganutzui-Deicher, and Forssman types. Antigen(s) cross-reactive with the heterophile Ab was found only in goat red blood cells (RBC) but absent on RBC of other species, in various tissue homogenates of syngeneic mice, or in SJ parasites and their eggs. The Ab activity seems to be mainly localized in immunoglobulin classes other than IgM.

Hemolytic factors in Schistosoma japonicum eggs

Extracts of Schistosoma japonicum eggs were found to exhibit hemolytic activity on erythrocytes of various species. The hemolytic reaction took place more rapidly at 37 degrees C than at 4 degrees C and did not require divalent cations. The degree of hemolysis was dependent on the concentration of the egg extracts. The hemolytic factors seemed to be lipid in nature because of being heat-stable and soluble in chloroform solvent. Further analysis by means of thin-layer chromatography showed that hemolytic activity in the extracts was due to free fatty acids. Analysis by gas chromatography revealed that fatty acids in the egg extracts consist of myristic, palmitic, palmitoleic, stearic, oleic, linoleic, linolenic, and arachidonic acids. Among them, based on the experiments with commercially available fatty acids, arachidonic acid was the most intensively hemolytic, followed by linoleic, linolenic, oleic, palmitoleic, and myristic acids in that order, whereas palmitic acid showed weak activity only in the presence of divalent cations. From the estimated calculation, it was assumed that 1 mg of protein of the egg extracts contains as much as 0.22 mg of free fatty acids.

The presence of anti-sheep red blood cell heterophile antibodies and their characteristics in murine schistosomiasis japonica

Sensitive methods of an enzyme-linked immunosorbent assay (ELISA) using red blood cells (RBC) have been developed and were applied to the detection of anti-sheep red blood cell (SRBC) heterophile antibodies (Ab) present in sera of Schistosoma japonicum (SJ)-infected mice. The indirect hemagglutination test (IHA) was used for the purpose as well. By these methods a significant increase in the heterophile Ab levels was demonstrated in the mice particularly after 6-10 weeks of infection. The heterophile Ab in SJ-infected mice were predominantly immunoglobulins resistant to 2-mercaptoethanol treatment and had temperature-independent reactivity. In an attempt to investigate the immunological specificity of the heterophile Ab, various absorption tests were performed; Davidsohn's differential absorption test revealed that the heterophile Ab were distinct from Forssman antibody, Paul-Bunnell antibody and heterophile agglutinins known to appear in serum sickness. The heterophile Ab were absorbed only with SRBC and goat red blood cells, not with other species of RBC such as human O Rh-, O Rh+, A Rh+, B Rh+, mouse, ox, chicken, horse, rabbit, guinea pig, and rat RBC, or syngeneic tissue homogenates including brain, lung, liver, spleen, kidney, muscle, and thymus. This heterophile antibody response is not a consequence of a specific immune response directed to the antigens of SJ parasites, since absorption of the heterophile Ab with SJ adult worms or an egg preparation did not reduce the heterophile Ab level.

[Studies on predilection area of gastric ulcer viewed from gastric motility (author's transl)]

Clinically, most gastric ulcers are located in the region of the incisura angularis, but they are least found along the greater curvature. To elucidate this difference, following experiments were carried out. A total of 22 mongrel dogs were used. A set of bipolar electrodes and/or a water-proof strain gage were chronically implanted at both the incisura and the corresponding site of the greater curvature. Electrical and contractile activities of these two sites were compared at the fasted state and under the stimulations by food, neostigmine and tetragastrin. Results are summarized as follows. 1. Electromyographically, the propagation velocity was always greater along the greater curvature than the lesser curvature. The discharge interval of BER and incidence of antiperistalsis were identical for both the lesser and greater curvature. 2. Through the course before and after the stimulation, there was no difference in the frequency of contraction waves, while the amplitude and motility index of the contraction were definitely greater at the incisura than the corresponding greater curvature. In conclusion, the present study revealed that the contractile force of the incisura was always greater than that of the corresponding greater curvature. It is possible that the peristaltic contraction could cause stronger repetitive ischemic condition of the incisura than the corresponding greater curvature. It is estimated that the gastric motility is one of the important factors for the predilection or delayed healing of gastric ulcers seen in the region of the incisura angularis.