Whether or not prophylactic excision of the extrahepatic bile duct is appropriate for patients with pancreaticobiliary maljunction without bile duct dilatation

BACKGROUND/AIMS

The standard treatment for patients with a pancreaticobiliary maljunction (PBM) without bile duct dilatation remains controversial.

METHODOLOGY

We followed up 29 patients with such PBM who mainly underwent a cholecystectomy alone. The ages of the patients ranged from 3 to 76 years (average age 47.3 years) and the ratio of males to females was 8 vs. 21. When the diameter of the common bile duct was less than 10mm, such bile ducts were diagnosed to have no dilatation. The main clinical indications for surgery were cholecystolithiasis in 15 patients, choledocholithiasis in 3, cholecystocholedocholithiasis in 2, gallbladder polyp in 2, adenomyomatosis in 2, cholecystitis in 2, and protein plug in 1.

RESULTS

The amylase levels of gallbladder bile in 20 patients ranged from 115 to 460,200 IU/mL (a mean of 191,698 IU/mL). One patient died of gastric cancer 182 months after surgery and two patients died of other diseases 153, 171 months after surgeries, respectively. The remaining 26 patients have all been doing well for 36 months to 326 months after surgery (a median follow-up period, 160.5 months). The 10- and 15-year survival rates were 100% and 89.7%.

CONCLUSIONS

In conclusion, a prophylactic resection of the extrahepatic bile duct and biliary diversion could be unnecessary for patients with PBM without bile duct dilatation.

Late-onset biliary leakage after laparoscopic cholecystectomy using laparoscopic coagulating shears. Report of a case

We recently encountered a rare case of late-onset biliary leakage after laparoscopic cholecystectomy using laparoscopic coagulating shears (LCS). The patient was a 49-year-old Japanese man who had undergone a laparoscopic cholecystectomy at Hamamatsu Medical Center after a diagnosis of cholecystolithiasis associated with localized adenomyomatosis. The cystic duct and the cystic artery were closed using LCS instead of metal endoclips. The postoperative course was uneventful, and the patient was discharged on the 4th operative day. However, on the 7th day after the surgery, the patient developed severe upper abdominal pain and was readmitted to our center with the diagnosis of a late biliary leakage, which was confirmed by an endoscopic retrograde cholangiogram. We then treated the leak successfully with endoscopic nasobiliary drainage.

A critical role of Fc receptor-mediated antibody-dependent phagocytosis in the host resistance to blood-stage Plasmodium berghei XAT infection

Plasmodium berghei XAT is an irradiation-induced attenuated variant derived from the lethal strain P. berghei NK65, and its blood-stage parasites are spontaneously cleared in immune competent mice. In the present study, we studied the mechanism of host resistance to blood-stage malaria infection using P. berghei XAT. Infection enhanced Ab-dependent phagocytosis of PRBC by splenic macrophages in wild-type C57BL/6 mice. In contrast, FcR gamma-chain knockout (FcRgamma(-/-)) mice, which lack the ability to mediate Ab-dependent phagocytosis and Ab-dependent cell-mediated cytotoxicity through FcgammaRI, FcgammaRII, and FcgammaRIII, could not induce Ab-dependent phagocytic activity. These FcRgamma(-/-) mice showed increased susceptibility to the P. berghei XAT infection, with eventually fatal results, although they produced comparable amounts of IFN-gamma by spleen cells and anti-XAT Abs in serum. In addition, passive transfer of anti-XAT IgG obtained from wild-type mice that had recovered from infection into FcRgamma(-/-) mice could not suppress the increase in parasitemia, and almost all of these mice died after marked parasitemia. In contrast, passive transfer of anti-XAT IgG into control wild-type mice inhibited the increase in parasitemia. IFN-gamma(-/-) mice, which were highly susceptible to the P. berghei XAT infection, failed to induce Ab-dependent phagocytic activity and also showed reduced production of serum anti-XAT IgG2a isotype compared with control wild-type mice. These results suggest that FcR-mediated Ab-dependent phagocytosis, which is located downstream of IFN-gamma production, is important as an effector mechanism to eliminate PRBC in blood-stage P. berghei XAT infection.

Gallbladder volvulus: experience of six consecutive cases at an institute

Recently we treated three patients with gallbladder volvulus within a short period. All three patients were examined preoperatively using computed tomography (CT). The first two cases were not diagnosed accurately before laparotomy. A precise diagnosis was made for the third one prior to surgery, based on our former experiences. Typical images, with marked edema and thickened wall of the gallbladder volvulus were shown on CT. We discuss six consecutive cases of the disease experienced at Hamamatsu Medical Center (i.e., the three patients rofed above, and three who did not have preoperative CT).

Increased hepatocyte growth factor content in rat stomach during omeprazole treatment

BACKGROUND AND AIMS

Hepatocyte growth factor (HGF) is a potent mitogen of gastric epithelial cells, and its production is stimulated during the healing of gastric mucosal lesions. In this study, the effect of a proton pump inhibitor, omeprazole, on the production and degradation of HGF in the stomach was examined to elucidate the mechanism of the omeprazole-induced acceleration of gastric mucosal healing.

METHODS

Indomethacin-induced gastric mucosal lesions were induced in rats with or without omeprazole pretreatment. HGF gene expression and the content of HGF was investigated in the rat stomach. HGF degradation by gastric juice was also tested.

RESULTS

In omeprazole-treated rats, the healing of gastric mucosal lesions was accelerated in comparison with those of untreated rats. Although omeprazole treatment did not enhance the indomethacin-induced increase in HGF gene expression, it significantly augmented the gastric HGF content. Furthermore, omeprazole increased the gastric content not only of the inactive but also of the active heterodimeric form of HGF, and this appeared to be due to the inhibition of the HGF degradation by gastric juice.

CONCLUSION

Omeprazole-induced acceleration of gastric mucosal healing may be mediated at least in part by the reduced degradation of HGF in the stomach.

Roles of CD4(+) T cells and gamma interferon in protective immunity against Babesia microti infection in mice

Babesia microti produces a self-limiting infection in mice, and recovered mice are resistant to reinfection. In the present study, the role of T cells in protective immunity against challenge infection was examined. BALB/c mice which recovered from primary infection showed strong protective immunity against challenge infection. In contrast, nude mice which failed to control the primary infection and were cured with an antibabesial drug did not show protection against challenge infection. Treatment of immune mice with anti-CD4 monoclonal antibody (MAb) diminished the protective immunity against challenge infection, but treatment with anti-CD8 MAb had no effect on the protection. Transfer of CD4(+) T-cell-depleted spleen cells resulted in higher parasitemia than transfer of CD8(+) T-cell-depleted spleen cells. A high level of gamma interferon (IFN-gamma), which was produced by CD4(+) T cells, was observed for the culture supernatant of spleen cells from immune mice, and treatment of immune mice with anti-IFN-gamma MAb partially reduced the protection. Moreover, no protection against challenge infection was found in IFN-gamma-deficient mice. On the other hand, treatment of immune mice with MAbs against interleukin-2 (IL-2), IL-4, or tumor necrosis factor alpha did not affect protective immunity. These results suggest essential requirements for CD4(+) T cells and IFN-gamma in protective immunity against challenge infection with B. microti.

Gamma interferon production is critical for protective immunity to infection with blood-stage Plasmodium berghei XAT but neither NO production nor NK cell activation is critical

We have examined the roles of gamma interferon (IFN-gamma), nitric oxide (NO), and natural killer (NK) cells in the host resistance to infection with the blood-stage malarial parasite Plasmodium berghei XAT, an irradiation-induced attenuated variant of the lethal strain P. berghei NK65. Although the infection with P. berghei XAT enhanced NK cell lytic activity of splenocytes, depletion of NK1.1(+) cells caused by the treatment of mice with anti-NK1.1 antibody affected neither parasitemia nor IFN-gamma production by their splenocytes. The P. berghei XAT infection induced a large amount of NO production by splenocytes during the first peak of parasitemia, while P. berghei NK65 infection induced a small amount. Unexpectedly, however, mice deficient in inducible nitric oxide synthase (iNOS-/-) cleared P. berghei XAT after two peaks of parasitemia were observed, as occurred for wild-type control mice. Although the infected iNOS-/- mouse splenocytes did not produce a detectable level of NO, they produced an amount of IFN-gamma comparable to that produced by wild-type control mouse splenocytes, and treatment of these mice with neutralizing anti-IFN-gamma antibody led to the progression of parasitemia and fatal outcome. CD4(-/-) mice infected with P. berghei XAT could not clear the parasite, and all these mice died with apparently reduced IFN-gamma production. Furthermore, treatment with carrageenan increased the susceptibility of mice to P. berghei XAT infection. These results suggest that neither NO production nor NK cell activation is critical for the resistance to P. berghei XAT infection and that IFN-gamma plays an important role in the elimination of malarial parasites, possibly by the enhancement of phagocytic activity of macrophages.

Midkine gene expression in the healing process of gastric ulcer

Midkine is a newly cloned growth-promoting factor for fibroblastic cells. This study was performed to investigate the possible role of midkine in the stomach. Rats with acute or chronic gastric mucosal lesions were used. Histologically, acute mucosal lesions are not accompanied by the formation of granulation tissue; conversely, chronic mucosal lesions are accompanied by the formation of granulation tissue. The expression of the midkine gene was found in the normal intact gastrointestinal tract, especially the submucosal and muscle layers. Midkine mRNA increased during the healing stage of chronic gastric ulcer accompanied by a fibroblastic reaction. Furthermore, the fibroblast cell line MRC-5 expressed midkine mRNA strongly. Therefore, midkine may have some role in the healing of gastric deep ulcers that is accompanied by fibroblast proliferation.

[Evaluation of the efficacy and the cost-effectiveness of proton pump inhibitor-based dual and triple therapy regimens for H. pylori eradication in peptic ulcer disease]

To evaluate the efficacy and the cost-effectiveness of H. pylori eradication for the treatment of peptic ulcer disease, a randomized controlled trial to compare the efficacy of proton pump inhibitor-based dual and triple regimens was conducted. A decision analysis was also performed to assess H. pylori eradication compared to the conventional maintenance strategy. Two hundred and thirty-four peptic ulcer patients suffering from H. pylori infection were randomly treated with either omeprazole 20 mg bid + amoxicillin 500 mg qid + clarithromycin 400 mg bid (OAC) or with omeprazole 20 mg bid + clarithromycin 400 mg bid (OC) for 14 days. The eradication rate with OAC was 87.6% (92/105) (95% Confidence Interval (CI): 81-94%), which was significantly higher than that with OC (61.9% (60/97) (95% CI: 52-72%)) (p < 0.001, chi 2 test). Both regimens were safe and well tolerated. H. pylori eradication was more effective and less costly than conventional strategy in a long term perspective. OAC was more cost-effective than OC. In conclusion, H. pylori eradication is a cost-effective alternative to conventional treatment. We recommend 2 weeks triple regimen with omeprazole 20 mg bid + amoxicillin 500 mg qid + clarithromycin 400 mg bid (OAC) as a first-line treatment in all patients with peptic ulcers associated with H. pylori infection.

Regenerating gene protein may mediate gastric mucosal proliferation induced by hypergastrinemia in rats

BACKGROUND & AIMS

Regenerating gene (Reg) has been isolated from rat regenerating pancreatic islets, and Reg protein is mitogenic to islet cells. We have recently shown that Reg gene and Reg protein are expressed in gastric enterochromaffin-like (ECL) cells. This study aimed to clarify whether gastrin enhances Reg protein production in ECL cells and whether Reg protein is mitogenic to gastric mucosal cells.

METHODS

Reg gene expression in response to acute and chronic hypergastrinemia was investigated in rats. Immunohistochemical studies, Northern blotting, and in situ hybridization were performed to investigate the expression of Reg protein and Reg gene. The direct effect of gastrin on Reg gene expression was investigated using isolated ECL cells, and the trophic effect of Reg protein on cultured gastric epithelial cells was assessed by [3H]thymidine uptake.

RESULTS

Both chronic hypergastrinemia and short-term gastrin administration stimulated Reg gene expression and Reg protein production in fundic mucosa. Reg gene expression was also augmented in isolated ECL cells after incubation with rat gastrin. Reg protein was mitogenic to cultured rat gastric epithelial cells.

CONCLUSIONS

Gastrin stimulates the production of Reg protein in gastric ECL cells, which may be involved in the gastrin-induced gastric mucosal cell growth.

Relationship between severity and symptoms of reflux oesophagitis in elderly patients in Japan

Since information concerning reflux oesophagitis in the elderly is limited, particularly in Japan, the severity and symptomatic profiles of reflux oesophagitis in elderly patients were investigated. One hundred and nineteen patients with reflux oesophagitis found among 2278 endoscopy cases between 1993 and 1996 were investigated in this study. The patients were divided into two groups, elderly and non-elderly. The severity of reflux oesophagitis was estimated by the Los Angeles classification. The presence or absence of typical symptoms (heartburn and regurgitation) was determined by interview. Reflux oesophagitis was not only more frequently found in the elderly group, but was more severe than in the non-elderly. Although the degree of manifestation of typical symptoms was similar between the elderly and the non-elderly with high-grade oesophagitis, the elderly patients with mild reflux oesophagitis were less symptomatic than the non-elderly. Mild reflux oesophagitis in the elderly may be missed due to its rarity of typical reflux symptoms and a substantial number of elderly persons might have subclinical reflux oesophagitis.

Rat gastric mucosal cells express ICAM-1 and proinflammatory cytokines during indomethacin-induced mucosal injury

Adhesion molecules and cytokines are known to be involved in the formation of acute gastric mucosal injury. However, it is not clear whether the gastric mucosal cells express these molecules and modulate the inflammation. To clarify whether gastric mucosal cells express intercellular adhesion molecule-1 (ICAM-1) and proinflammatory cytokines (tumor necrosis factor-alpha (TNF-alpha), interleukin-1-alpha (IL-1-alpha), and cytokine-induced neutrophil chemoattractant-2-beta (CINC-2-beta)) in the formation of gastric mucosal injury, we have used rat indomethacin-induced gastric mucosal lesions as an in vivo model. The gene expression of all cytokines and ICAM-1 increases at the early stages of indomethacin-induced gastritis (TNF-alpha and IL-1-alpha gene expression began to increase earlier than that of ICAM-1 and CINC-2-beta) and can mainly be detected in the gastric epithelial layer. To further identify the source of those molecules, the epithelial cells were separated into seven fractions according to their sizes by a counterflow elution. ICAM-1 and CINC-2-beta gene expressions are particularly enhanced in the middle-sized cell fractions that are rich in gastric mucous-producing cells. The effect of TNF-alpha or IL-1-alpha on the gene expression of ICAM-1 and cytokines was examined by using RGM-1 cells as a model for gastric mucosal cells. RGM-1 cells show an augmented ICAM-1 and proinflammatory cytokine expression in response to TNF-alpha or IL-1-alpha stimulation. Moreover, immunohistochemical staining also reveals an increase in ICAM-1 and CINC protein production in RGM-1 cells in response to TNF-alpha stimulation. We conclude that gastric mucosal cells express various cytokines and an adhesion molecule during the formation of acute gastric mucosal injury and that they may modulate the inflammation.

A pathogenic role of IL-12 in blood-stage murine malaria lethal strain Plasmodium berghei NK65 infection

We studied whether the infection with a blood-stage murine malaria lethal Plasmodium berghei NK65 induces IL-12 production, and if so, how the IL-12 production is involved in the protection or pathogenesis. The infection of C57BL/6 mice enhanced mRNA expression of IL-12 p40 and also IFN-gamma, IL-4, and IL-10 in both spleen and liver during the early course of the infection. It also enhanced the mRNA expression of TNF-alpha, Fas ligand, and cytokine-inducible nitric oxide synthase. Increased IL-12 p40 production was also observed in the culture supernatant of spleen cells and in sera of infected mice. In addition, the infection caused massive liver injury with elevated serum glutamic-oxaloacetic transaminase and serum glutamic-pyruvic transaminase activities and body weight loss. Treatment of these infected mice with neutralizing mAb against IL-12 prolonged the survival and diminished the liver injury with reduced elevation of serum serum glutamic-oxaloacetic transaminase and serum glutamic-pyruvic transaminase activities and decreased body weight loss. However, the anti-IL-12 treatment did not affect parasitemia, and all these mice eventually died. Similar results were obtained when infected mice were treated with neutralizing mAb against IFN-gamma. Moreover, anti-IL-12 treatment greatly reduced the secretion and mRNA expression of IFN-gamma in both spleen and liver. These results suggest that the lethal P. berghei NK65 infection induces IL-12 production and that the IL-12 is involved in the pathogenesis of liver injury via IFN-gamma production rather than the protection.

Interleukin-12-dependent mechanisms in the clearance of blood-stage murine malaria parasite Plasmodium berghei XAT, an attenuated variant of P. berghei NK65

The mechanism of development of host resistance to blood-stage malarial infection was studied by use of an irradiation-induced attenuated variant, Plasmodium berghei XAT, obtained from a lethal strain, P. berghei NK65. The infection enhanced mRNA expression of interleukin (IL)-12 p40 and also of interferon (IFN)-gamma, IL-4, IL-10, and cytokine-inducible nitric oxide synthase (iNOS) in spleen. Treatment of these mice with anti-IL-12 or anti-IFN-gamma led to the progression of parasitemia and fatal outcome. Anti-IL-12 treatment significantly reduced the secretion and mRNA expression of IFN-gamma and greatly diminished the augmentation of iNOS mRNA expression. In addition, recombinant IL-12 administration delayed the onset of parasitemia because of the enhanced IFN-gamma production. These results suggest that blood-stage P. berghei XAT infection induces IL-12 production, which is important for the development of host resistance via IFN-gamma production.

Severe muscle damage induced by high carbohydrate intake from elemental diet in a patient with Crohn's disease

Crohn's disease is associated with complications in multiple organs. However, there are very few reported cases of patients with Crohn's disease with muscle symptoms and/or high serum creatine phospho-kinase (CPK) levels. We report here a patient with Crohn's disease who experienced skeletal muscle damage with extremely high serum CPK level during treatment with an elemental diet. The non-parenteral administration of large amounts of carbohydrate and limited glycogen degradation capability may be a possible causative mechanism for this elemental diet-induced muscle damage.

Reduced T helper 1 responses in IL-12 p40 transgenic mice

To investigate the antagonistic effect of IL-12 p40 on IL-12 activity in vivo, we generated transgenic (Tg) mice in which p40 gene was regulated by a liver-specific promoter. Three Tg mouse lines were generated, and they expressed the p40 transgene predominantly in liver. Serum p40 level was extremely high, and it consisted of mainly monomer and homodimer and also of higher m.w. complexes. These Tg mice did not show any apparent phenotypic difference from control littermates in lymphoid cells. Enhancement of NK cell lytic activity in spleen by administration of rIL-12 to these mice was greatly diminished. Ag induced cytokine production was impaired: decreased production of IFN-gamma and increased production of IL-4 and IL-10. Delayed-type hypersensitivity response was also significantly reduced. Moreover, these Tg mice showed increased susceptibility to the infection with an intracellular pathogen, blood-stage Plasmodium berghei XAT, which is an irradiation-induced attenuated substrain of P. berghei NK65, presumably due to the decreased IFN-gamma production. These results suggest that p40 functions as an IL-12 antagonist in vivo, and that Th1 responses in p40 Tg mice are significantly reduced. Thus, these Tg mice could be a useful model to evaluate the inhibitory effect of p40 on IL-12-mediated various immune responses in vivo.

Effect of aging on gastrin receptor gene expression in rat stomach

Gastrin is a pivotal humoral factor which regulates gastric acid secretion through its receptors. There is no report, however, concerning the age-related changes of gastrin receptor gene expression in the stomach. Northern blot analysis and in situ hybridization were performed to clarify the changes of gastrin receptor expression during the aging. In situ hybridization clarified that gastrin receptor mRNA was expressed mainly in enterochromaffin-like (ECL) cells in adult rat gastric mucosa. With aging, gastrin receptor gene expression in the stomach increased with the concomitant increase in histidine decarboxylase mRNA. Since histidine decarboxylase is a marker of gastric ECL cells, the augmented gastrin receptor mRNA in aged rats may be caused by the increased ECL cells in gastric mucosa during the aging.

Intragastric distribution of nonsteroidal anti-inflammatory drug-related ulcers in patients without collagen diseases

During the long-term administration of nonsteroidal anti-inflammatory drugs (NSAIDs), approximately 3% of patients have gastric ulcers develop in each year. Although much is known about the endoscopic characteristics of NSAID-induced gastric ulcers in patients with rheumatoid arthritis (RA), it is not clear where in the stomach NSAIDs induce ulcers in patients without RA. We looked at that question. During the 1-year study period, 29 patients with gastric ulcer, who had been taking NSAIDs regularly for more than 4 weeks mainly for osteoarthritis, were identified. Seventy-five patients with gastric ulcers who had not taken NSAID also were found. The sites of gastric ulcers of these two groups were quite different. The NSAID-induced ulcers mainly were found in the gastric antrum, whereas the majority of NSAID-unrelated ulcers were in the gastric corpus. We conclude that NSAID-induced ulcers in non-RA patients mainly are formed in the gastric antrum.

Helicobacter pylori induces proinflammatory cytokines and major histocompatibility complex class II antigen in mouse gastric epithelial cells

Although Helicobacter pylori has been reported to stimulate the release of various cytokines from gastric tissue, it remains unknown whether normal and nontumorous gastric epithelial cells produce these cytokines. Therefore, in this study, we used a normal mouse gastric surface mucous cell line (GSM06) to determine whether gastric epithelial cells produce proinflammatory cytokines in response to H. pylori. The expression of MHC class II antigen was also examined, to investigate whether gastric epithelial cells participate in the immune response to H. pylori. In the study, GSM06 cells were incubated with H. pylori or its lipopolysaccharide (LPS). Proinflammatory cytokines were detected by Northern and Western blot analysis. The expression of MHC class II antigen was examined by fluorescence activated cell sorter (FACS) analysis. Genetic expression of proinflammatory cytokines such as interleukin-1alpha, tumor necrosis factor-alpha, and cytokine-induced neutrophil chemoattractant-2beta was enhanced by both intact and sonicated H. pylori, but not by H. pylori LPS. The expression of MHC class II antigen was induced by H. pylori more strongly than by interferon-gamma. We conclude that H. pylori induces the expression of proinflammatory cytokines and MHC class II antigen in gastric epithelial cells. Gastric epithelial cells may act as antigen-presenting cells and participate in the immune response to H. pylori infection.

Developmental gene expression of gastrin receptor in rat stomach

Gastrin, which is present in fetal plasma, may have important roles in the development of gastric mucosa, since it is not only a potent stimulator of gastric acid secretion but also a growth promoting factor. Gastrin regulates various cellular functions via its receptors on cell membrane. Therefore, in order to elucidate a role for gastrin in the development of gastrointestinal system during gestation, Northern blot analysis was performed. The results of the study suggested that gastrin receptor is mainly present on parietal cells. Furthermore, proton pump and gastrin receptor gene expressions in parietal cells were strongly stimulated by the administration of exogenous gastrin. In conclusion, gastrin may be involved in the developmental change of parietal cells through its receptors.

"Mediterranean lymphoma" treated with antibiotics

We report a case of Mediterranean lymphoma treated with antibiotics. A 74-year-old woman visited the hospital due to abdominal pain. Endoscopic examination showed erosions and ulcerations on duodenal mucosa. Biopsy specimens histologically revealed massive infiltration of small-sized lymphocytes and plasma cells in subepithelial mucosa. Immunoperoxidase staining showed that the infiltrating cells were positively stained with anti-alpha heavy chain. Serum IgA concentration was elevated and immunoelectrophoresis of the serum demonstrated monoclonal protein composed of alpha heavy chain. During the antibiotic treatment her symptoms disappeared and serum IgA concentration was normalized. Endoscopic examination also showed healing of the duodenal ulceration. The similarities between Mediterranean lymphoma and gastric mucosa-associated lymphoid tissue (MALT) type lymphoma, both of which may be related to bacterial infection and can be treated with antibiotics, are discussed in this report.

Interferon-gamma and the induction of protective IgG2a antibodies in non-lethal Plasmodium berghei infections of mice

Mice treated with anti-IFN-gamma monoclonal antibodies were unable to recover from infection with an attenuated variant of P. berghei (Pb XAT) which causes non-lethal malaria in normal mice. On the other hand, treatment with anti-IL-4 monoclonal antibodies had no effect on the course of infection. IFN-gamma was produced by spleen cells in vitro during the early phase of the infection. Treatment with anti-IFN-gamma suppressed development of an anti-plasmodial IgG2a immunoglobulin isotype in the serum of infected mice whereas anti-IL-4 interfered with the IgG1 response. An IgG2a fraction of immune serum collected from mice that had recovered from Pb XAT transferred immunity to naive mice but the IgG1 fraction did not. When glutaraldehyde fixed parasitized erythrocytes were incubated with immune serum in suspension, specific IgG2a antibodies were detected by fluorescein staining on the membranes of cells infected with mature stages of parasites. These results indicate that IFN-gamma is a key to inducing B cells to produce the protective antiplasmodial IgG2a immunoglobulin isotype. Antibody-dependent cell-mediated parasite killing seems to be involved in the mechanism of recovery from infection with Pb XAT.

Dirofilaria immitis: immunohistochemical localization of acid proteinase in the adult worm

The distribution of Dirofilaria immitis acid proteinase in adult worm tissue was examined biochemically and immunohistochemically. About 45% of the total proteinase activity of 700g supernatant, which was obtained from the 0.25 M sucrose homogenate of live adult worms, was found in the 100,000g supernatant by subcellular centrifugation analysis. The distribution pattern of the proteinase activity observed by Percoll density gradient centrifugation coincided with that of glucose-6-phosphatase, a marker cytosolic enzyme, suggesting that the acid proteinase was present in vivo in a membrane-free form, possibly in the cytosol or secretory fluid. Immunostaining for the proteinase in the parasite tissue using the IgG1 (kappa-type) monoclonal antibody, H-1, revealed immunoreactive enzyme primarily inside the cell as small grains, but not on the cell surface, and immunoreactivity was distributed widely in worm tissues such as lateral cords, dorsal and ventral median cords, the anterior end of the parasite, and intestinal epithelial cells in granular form. In the male reproductive system, the testicular wall and germ cells were labeled with the antibody, and in the female, uterine walls, fertilized eggs, and developing eggs as well as microfilaria were labeled. In conclusion, D. immitis acid proteinase is widely distributed in the parasite tissue, possibly functioning not only in nutrition metabolism but also in production of sperm and microfilariae, etc.

Antibody-dependent neutrophil-mediated parasite killing in non-lethal rodent malaria

The effects of administrating recombinant human granulocyte colony-stimulating factor (rhG-CSF) and passively transferring immune serum on infection with an attenuated variant of Plasmodium berghei XAT (Pb XAT), in severe combined immunodeficiency (SCID) mice were examined. In immune competent (C.B-17) mice, the attenuated parasite infection was inevitably self-resolving and degenerating forms inside erythrocytes appeared, coinciding with the drop in parasitaemia, whereas SCID mice were unable to control parasite growth and all the mice died. Continuous administration with rhG-CSF caused neutrophilic granulocytosis in both SCID and C.B-17 mice. The effect of rhG-CSF on the infection in C.B-17 mice was to suppress the course of the parasitaemia at an early phase whereas it had no effect in SCID mice. When immune serum was transferred on the day of infection, the prepatent period was prolonged two days in both SCID and C.B-17 mice. When administration with rhG-CSF was combined with transfer of immune serum, SCID mice showed four days delay in patency and degenerating parasites were seen during the course of parasitaemia, although the infection was ultimately fatal. C.B-17 mice similarly treated showed a seven day delay in the onset of the patent parasitaemia which was of a lesser magnitude and shorter in duration compared with control mice. On the other hand, when C.B-17 mice were splenectomized three weeks before infection and then treated with rhG-CSF and immune serum, no degenerating parasites were seen during the infection and all mice died with high parasitaemias.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunoglobulin G2a isotype may have a protective role in Plasmodium berghei NK65 infection in immunised mice

All CBA mice that had been immunised by means of four successive inoculations of Plasmodium berghei NK65, each inoculation being followed by chemotherapy, survived an intravenous challenge inoculation of parasite, with 4/12 mice developing patent parasitaemia that resolved within 2 weeks. In contrast, all non-immunised control mice died before the 10th day post-challenge. Examination of sera for antibodies revealed that the immunised mice, all of which survived the challenge, had significantly high anti-plasmodial whole IgG, IgG1, and IgG2a titres before the challenge. A 16-fold rise in IgG2a titre alone was recorded on the 5th day post-challenge, with a further boosting of the titre to 4096 being observed on day 10. In comparison, the titres of Ig isotypes in the non-immunised control mice that succumbed to the challenge remained below 4. Specific IgG subclasses, in particular IgG2a, could be involved in the humoral immune protection against this rodent parasite.

Effect of recombinant human colony-stimulating factor on the course of parasitaemia in non-lethal rodent malaria

The effect of repeated subcutaneous injections of recombinant human granulocyte colony-stimulating factor (rhG-CSF) on the attenuated Plasmodium berghei XAT infection in CBA mice was examined. When mice were injected with rhG-CSF daily beginning 2 days before infection, the neutrophil count in the peripheral blood increased 5 times higher than that of control mice and the development of parasitaemia was suppressed significantly during the early phase of the infection. This suppressive effect of rhG-CSF was reduced by treatment of the mice with either anti-interferon (IFN)-gamma or anti-tumour necrosis factor (TNF)-alpha immunoglobulins. These results suggest that neutrophils may have a role in immunity against the parasites and that IFN-gamma and TNF-alpha are possibly involved.

A DNA hybridization assay for use in drug sensitivity tests in vitro for Plasmodium falciparum under field conditions

A deoxyribonucleic acid (DNA) hybridization technique was applied to in vitro drug sensitivity testing of P. falciparum using a synthetic 21-mer oligonucleotide coupled to alkaline phosphatase (PFR1-AP) to monitor development of parasite stages in culture. The density of the coloured spot clearly distinguished schizonts from ring forms. This assay system was applied in the field on Hainan Island, China. Blood samples obtained from patients were cultivated in the presence of antimalarial drugs and the minimum drug concentration required to inhibit development of parasites was determined by the DNA hybridization assay and by microscopical observation of Giemsa-stained blood smears. The 2 methods yielded identical results, indicating that the DNA hybridization assay can be used for in vitro drug sensitivity testing under field conditions.

The role of T cells in pathogenesis and protective immunity to murine malaria

T-cell-mediated immunity to a virulent strain of Plasmodium berghei NK65 (Pb NK65) and to an attenuated derivative (Pb XAT) of the strain were examined in CBA mice by the administration of monoclonal antibodies against T-cell subsets or interferon-gamma (IFN-gamma). The injection of anti-CD8+ or anti-IFN-gamma delayed the mortality of mice infected with Pb NK65, although it did not affect the parasitaemia. In the late stage of PB NK65 infection, T cells, especially CD8+ T cells, were increased in number in the liver at the expense of splenic CD8+ T cells. These CD8+ T cells released IFN-gamma in culture without antigen stimulation and were thought to induce tumour necrosis factor-alpha (TNF-alpha) production by the cells in the liver. In mice infected with Pb XAT, or mice primed with Pb XAT and then challenged with Pb NK65, CD4+ T cells had a crucial role in preventing parasite growth and in protective immunity. IFN-gamma was again the key molecule in protective immunity. These results suggest that T cells stimulated with malaria antigen play important roles both in protective immunity and pathogenesis depending upon their subsets; CD8+ T cells in pathogenesis, and CD4+ T cells in protective immunity. These apparently contradictory responses may be mediated by the same cytokine, IFN-gamma.

[A case of bone and lung metastasis of breast cancer successfully treated with radiotherapy, chemotherapy and endocrine therapy]

A 34-year-old female patient with breast cancer metastasizing to bone had a remission after a course of treatment with medroxyprogesterone acetate (MPA) 1,200 mg/day, but again had a metastasis to the lungs. The patient was then instituted on a combination therapy with UFT 400 mg/day, and MPA 1,200 mg/day. As a result, the pulmonary metastasis disappeared, along with the consolidation of the bone involved.

Membrane potential of Plasmodium falciparum gametocytes monitored with rhodamine 123

The membrane potential of Plasmodium falciparum gametocytes was monitored with the cationic permeant fluorescent dye rhodamine 123 (R123) as a probe. Epifluorescence microscopy revealed that R123 at 1 microgram/ml rather selectively partitioned into structure resembling large mitochondria. Treatment of R123-loaded gametocytes with various inhibitors including those of respiration resulted in disappearance of fluorescence from what appeared to be the mitochondria, but not from the cytosol. These results indicate that P. falciparum gametocytes have the mitochondrion maintaining an inside negative membrane potential.

[Chloroquine-resistant Plasmodium falciparum malaria confirmed by semi-micro sensitivity test for chloroquine seen in a person returned from Nigeria to Japan]

A 39-year-old Japanese male engineer who stayed in Nigeria from August 17, 1987 through January 22, 1988, presented chloroquine-resistant Plasmodium falciparum malaria. He was taking oral chloroquine prophylactically. But he suffered from P. falciparum malaria in November, 1987 and early January, 1988. He was treated in Nigeria. After his return to Japan, he was admitted to our hospital with a fever of 39 degrees C on January 29, 1988. The peripheral blood smear on admission showed the presence of ring form P. falciparum. He was diagnosed as recrudescence of P. falciparum malaria. Laboratory examination revealed severe thrombocytopenia and biologic false-positive serological tests of syphilis. The level of 50% inhibitory concentration was 0.44 nmol/ml by in vitro chloroquine sensitivity test of the strain of P. falciparum obtained from this patient. Clinically, chloroquine was not effective. The patient was treated with intravenous quinine dihydrochloride followed by sulfadoxine/pyrimethamine tablets and recovered completely. As far as we know through our survey this patient was the first case of chloroquine-resistant P. falciparum malaria brought to Japan from Nigeria.

Acquirement of protective immunity in mice through infection with an attenuated isolate and its failure in parent virulent Plasmodium berghei

In virulent Plasmodium berghei infection, mice showed suppressive responses to sheep red blood cells SRBC (PFC) as well as the parasite antigen (DTH) and developed autoantibodies against homologous lymphocytes. On the other hand, mice infected with an attenuated variant derived from P. berghei did not show these responses but developed solid protective immunity against parent parasite infection accompanied by high antibody titre. When such an immune serum was transferred into mice, attenuated parasite infection was completely eliminated. These results show that an attenuated variant stimulates antibody production, which contributes to protection against the parasites. In contrast, in virulent P. berghei infections harmful immunopathological responses against the host are more prominent than protective immune responses against the parasites.

A marker epitope of attenuated Plasmodium berghei

Plasmodium berghei XAT is an irradiation-induced, permanent attenuated derivative from high-virulence P. berghei NK65. Monoclonal antibodies against XAT were developed. By immunofluorescence screening, one monoclonal antibody was identified that was reactive with XAT at the schizont stage but not with NK65 nor with any other stage of intra-erythrocytic development of either parasite. The monoclonal antibody precipitated a 240-kD molecule from metabolically labeled XAT antigens. This molecule was thought to be a marker epitope of the attenuated parasite.

An alternative approach to malaria vaccine with a permanent attenuated mutant from a high virulence Plasmodium berghei strain

An alternative approach to malaria vaccine with the use of Plasmodium berghei NK65XAT (XAT) is reviewed. XAT is a permanent low virulence strain derived from high virulence P. berghei NK65 (NK65) by irradiation. Although one organism of parent NK65 could kill one mouse, as many as 10(7) XAT parasites caused modest self limiting parasitaemia in immuno-competent mice. In the mice recovered from XAT infection, long lasting immunity to challenge not only by parent NK65, but also by ANKA so far as different species of rodent Plasmodia was seen. The XAT parasites invaded selectively into immature erythrocytes. Because of this feature, the attenuated parasite might induce potent and long-lasting immunity presumably with the background of MHC antigen expression on infected cells. Immunopathologic reactions in mice infected with XAT were modest comparing to those seen in mice with parent NK65 infection. Attenuation was also tested using P. yoelii nigeriensis with which cyclical transmission with A. stephensi was established. Although similar attenuation occurred by X-ray irradiation, produced parasites eventually reverted to virulence after several animal passages. Irradiation was also attempted to induce attenuated P. falciparum mutant and a parasite of a slow multiplication feature was obtained in an experiment. We would propose an alternative approach in the study of malaria vaccine using attenuated live organisms which confers potent and long lasting immunity to the host.

[A case of necrosis of a hepatocellular carcinoma, caused by spasm of the celiac artery]

A 54-year-old man was admitted to our hospital complaining of back pain and right hypochondrial pain. Ultrasonography and celiac angiography revealed a large tumor sized 9.4 X 8.1 cm. The tumor appeared hypervascular on angiogram. During the second angiography, an attempt at superselective hepatic angiography for the purpose of infusing a combination of Adriamycin and Lipiodol, spasm of the celiac artery occurred. High fever continued for 11 days after the spasm and serum transaminase was elevated. At the third angiography, the nature of the tumor was seen to have changed remarkably to one of hypovascularity. Percutaneous transhepatic tumor biopsy was done. Pathological diagnosis was necrosis of hepatocellular carcinoma. Due to heart disorders, ligation of the right hepatic artery was performed instead of hepatic resection. Postoperatively, the size of the tumor decreased further. It is thought that this patient had a tendency to suffer from vasospasm and that the tumor had a relatively low resistance to ischemia.