Postpartum infective endocarditis with Enterococcus faecalis in Japan: a case report.

BACKGROUND: The clinical characteristics of infective endocarditis include the presence of predisposing cardiac disease, a history of illegal drug use, and high morbidity in the elderly. Only a few cases of the disease after delivery have been reported in the literature. We describe here a first case of enterococcal postpartum infective endocarditis without underlying disease in Japan. CASE PRESENTATION: We report the case of a 31-year-old Japanese woman with postpartum infective endocarditis by Enterococcus faecalis. She had no significant medical history or any unusual social history. After emergency surgery for severe mitral regurgitation and antimicrobial treatment for 6 weeks, she was discharged from our hospital and is now being monitored at an out-patient clinic. CONCLUSIONS: We encountered a case of Enterococcus faecalis infective endocarditis that occurred in the native valve of a postpartum healthy woman. Although the pathogenesis of this case remains unclear, it could be due to bacteremia arising from the administration of prophylactic broad-spectrum antibiotics used for cesarean section. Previous use of cefotiam and urinary catheter insertion may be risk factors for nosocomial enterococcal bacteremia in this case.

walK and clpP mutations confer reduced vancomycin susceptibility in Staphylococcus aureus.

Vancomycin-intermediate Staphylococcus aureus (VISA) is generated from vancomycin-susceptible Staphylococcus aureus by multiple spontaneous mutations. We previously reported that sequential acquisition of mutations in the two-component regulatory systems vraSR and graRS was responsible for the VISA phenotype of strain Mu50. Here we report on the identification of a novel set of regulator mutations, a deletion mutation in two-component regulatory system walRK (synonyms, vicRK and yycFG), and a truncating mutation in a proteolytic regulatory gene, clpP, responsible for the raised vancomycin resistance in a laboratory-derived VISA strain, LR5P1-V3. The contributory effect of the two mutations to vancomycin resistance was confirmed by introducing the walK and clpP mutations into the vancomycin-susceptible parent strain N315LR5P1 by a gene replacement procedure. The vancomycin MIC of N315LR5P1 was raised from 1 to 2 mg/liter by the introduction of the walK or clpP mutation, but it was raised to 4 mg/liter by the introduction of both the walK and clpP mutations. The vancomycin MIC value of the double mutant was equivalent to that of strain LR5P1-V3. Like VISA clinical strains, LR5P1-V3 and the double mutant strain LR5P1walK*clpP* exhibited a thickened cell wall, slow growth, and decreased autolytic activity. Transcriptional profiles of the mutants with gene replacements demonstrated that introduction of both the walK and clpP mutations could alter expression of dozens or hundreds of genes, including those involved in cell envelope and cellular processes, intermediary metabolism, and information pathway. A mutation prevalence study performed on 39 worldwide clinical VISA strains showed that 61.5, 7.7, 10.3, and 20.5% of VISA strains harbored mutations in walRK, clpP, graRS, and vraSR, respectively. The mutation of walRK was most frequently carried by VISA strains. Together, these results suggested that the mutations of walK and clpP identified in LR5P1-V3 constitute a new combination of genetic events causing vancomycin resistance in Staphylococcus aureus.

An RpoB mutation confers dual heteroresistance to daptomycin and vancomycin in Staphylococcus aureus.

We have previously reported the establishment of a Staphylococcus aureus laboratory strain, 10 3d1, having reduced susceptibility to daptomycin and heterogeneous vancomycin-intermediate S. aureus (VISA) phenotype. The strain was generated in vitro by serial daptomycin selection (Camargo, I. L., H. M. Neoh, L. Cui, and K. Hiramatsu, Antimicrob. Agents Chemother. 52:4289-4299, 2008). Here we explored the genetic mechanism of resistance in the strain by whole-genome sequencing and by producing gene-replaced strains. By genome comparison between 10 3d1 and its parent methicillin-resistant Staphylococcus aureus (MRSA) strain N315ΔIP, we identified five nonsynonymous single nucleotide polymorphisms (SNPs). One of the five mutations was found in the rpoB gene encoding the RNA polymerase ß subunit. The mutation at nucleotide position 1862 substituted the 621st alanine by glutamic acid. The replacement of the intact rpoB with the mutated rpoB, designated rpoB(A621E), conferred N315ΔIP with the phenotypes of reduced susceptibility to daptomycin and hetero-VISA. The rpoB(A621E)-mediated resistance conversion was accompanied by a thickened cell wall and reduction of the cell surface negative charge. Being consistent with these phenotypic changes, microarray data showed that the expression of the dlt operon, which increases the cell surface positive charge, was enhanced in the rpoB(A621E) mutant. Other remarkable findings of microarray analysis of the rpoB(A621E) mutant included repression of metabolic pathways of purine, pyrimidine, arginine, the urea cycle, and the lac operon, enhancement of the biosynthetic pathway of vitamin B2, K1, and K2, and cell wall metabolism. Finally, mutations identified in rplV and rplC, encoding 50S ribosomal proteins L22 and L3, respectively, were found to be associated with the slow growth, but not with the phenotype of decreased susceptibility to vancomycin and daptomycin, of 10 3d1.

Contribution of vraSR and graSR point mutations to vancomycin resistance in vancomycin-intermediate Staphylococcus aureus.

We describe here the genetic analysis of a vancomycin-susceptible Staphylococcus aureus (VSSA) strain, Mu50Omega, a strain related to vancomycin-intermediate S. aureus (VISA) strain Mu50. Using a combination of Mu50Omega whole-genome sequencing and genome engineering, we observed a stepwise evolution of vancomycin resistance from VSSA to VISA after the mutated vraS and graR genes of Mu50 were engineered into Mu50Omega.

[Orotate phosphoribosyltransferase levels in gastric carcinoma and normal gastric mucosa - correlation with thymidylate synthase and dihydropyrimidine dehydrogenase levels and the changes after neoadjuvant chemotherapy].

Orotate phosphoribosyltransferase (OPRT, EC 2.4.2.10), a key enzyme that catalyzes one of the primary first-step phosphorylation processes of fluoropyrimidine, has recently been recognized as an important factor that primarily determines the anticancer effects of S-1. The OPRT levels were examined in 97 gastric carcinoma tissues and 65 normal gastric mucosa tissues obtained from patients with gastric carcinoma using a newly-developed enzyme-linked immunosorbent assay. Correlations with thymidylate synthase and dihydropyrimidine dehydrogenase levels and the effects of neoadjuvant chemotherapy were evaluated. The OPRT level in gastric carcinoma tissue was significantly higher than that in normal gastric mucosa. There was no correlation of OPRT level with either TS or DPD levels. There was no correlation of OPRT level between those in gastric carcinoma and those in normal gastric mucosa simultaneously obtained from identical patients. The OPRT levels in patients who underwent neoadjuvant chemotherapy were not different from those without neoadjuvant chemotherapy. These results suggest that activation of fluoropyrimidine mainly occurs in carcinoma tissues and the OPRT levels in carcinoma tissues were not influenced by neoadjuvant chemotherapy with fluoropyrimidine.

Randomized clinical trial of the effects of perioperative use of immune-enhancing enteral formula on metabolic and immunological status in patients undergoing esophagectomy.

BACKGROUND: Although perioperative immune-enhancing enteral formula (IEEF) is effective to decrease the rate of infectious complications, it is not clear whether perioperative use of IEEF decreases the incidence of postoperative complications and improves clinical outcome in patients who have undergone esophagectomy. A prospective randomized clinical trial was performed to examine the effects of perioperative IEEF on nutritional and immunological status in patients with esophageal carcinoma who have been treated with esophagectomy. METHODS: A total of 30 patients were randomly assigned to two groups, each receiving 3 days of preoperative and postoperative enteral nutrition through jejunostomy started within 24 h after operation, either with immune-enhancing enteral formula (group IEEF, n = 16) or with regular polymeric enteral formula (group C, n = 14). Preoperative and postoperative nutritional and immunological parameters and clinical outcome were examined. RESULTS: A significant increase in the serum concentration of ornithine was noted in group IEEF and it peaked at 5 days after surgery. The equivalent values were significantly lower in group C. There was no difference in serum dochosahexaic acid between the two groups. The n-3/n-6 fatty acid ratio in group IEEF was significantly higher than in group C at 7 days after surgery. Peripheral percent lymphocyte fraction and total lymphocyte count in group IEEF were both significantly higher than those in group C. While T cell fraction of peripheral lymphocytes in group IEEF at 3 days after surgery, B cell fraction in group IEEF at 5 and 7 days after surgery was significantly higher than those in group C, suggesting that perioperative IEEF caused a shift towards B cell proliferation. CONCLUSIONS: Perioperative use of IEEF caused a significant increase in the total lymphocyte count at 3 and 5 days after operation and caused a shift toward B cell proliferation, which may possibly be beneficial to decrease the incidence of postoperative infectious complications.

[Clinical and prognostic significance of protein and gene expression of orotate phosphoribosyltransferase in gastric carcinoma].

Although orotate phosphoribosyltransferase (OPRT EC 2.4.2.10) is a key enzyme related to the first-step activation process of 5-fluorouracil, and therefore it has been shown to be an important enzyme that enables to predict sensitivity to 5-fluorouracil, the clinical and prognostic significance of protein and/or gene expression of OPRT has not been well established in gastric carcinoma. We examined the protein level, and mRNA expression of OPRT in gastric carcinoma tissues and relationships with clinicopathologic factors and prognosis were evaluated. A total of 75 surgically-resected gastric carcinoma tissues were subjected to the study. An enzymelinked immunosorbent assay (ELISA) was used to accurately assess intratumoral OPRT, and gene expressions of OPRT were examined using a real-time PCR method. Survival of patients with gastric carcinoma in relation to OPRT protein levels was analyzed using Kaplan-Meier methods along with log-rank test. The mean value of OPRT was 5.4+/-3.6 ng/mg protein, and it was significantly higher in patients with differentiated-type and invasive-type gastric carcinoma. The prognosis of patients in the high OPRT group was better than for those with low OPRT (p<0.05). There was a significant correlation between OPRT levels measured by ELISA and OPRT mRNA expression (p<0.05). Determination of OPRT levels is a useful tool to predict the biological characteristics of gastric carcinoma and possibly predict sensitivity to fluoropyrimidine-based anticancer chemotherapy,particularly dihydropyrimidine dehydrogenase-inhibitory fluoropyrimidine, in patients with gastric carcinoma.

Orotate phosphoribosyltransferase levels measured by a newly established enzyme-linked immunosorbent assay in gastric carcinoma.

A number of enzymes have been shown to be involved in the process of activation and/or degradation of 5-fluorouracil (5-FU), and are potential candidates for predicting chemosensitivity to 5-FU. Among these, orotate phosphoribosyltransferase (OPRT EC 2.4.2.10) is a key enzyme related to the first-step activation process of 5-FU and has been shown to be an important enzyme that helps to predict sensitivity to 5-FU and its related derivatives. We developed a new enzyme-linked immunosorbent assay (ELISA) to accurately assess intratumoral activity of OPRT. A new sandwich ELISA was established using anti-OPRT polyclonal antibodies obtained from the rabbit immunized with the recombinant human peptides of the OPRT molecule. OPRT levels were measured in eight human cancer xenografts and in 75 gastric cancer tissues using both a newly established ELISA and a conventional enzyme assay, using radiolabeled 5-FU as a substrate. There was a significant correlation between OPRT levels measured by this ELISA and OPRT enzyme activity the in eight human cancer xenografts (r2 = 0.782) and gastric carcinoma tissue (r2 = 0.617). The ELISA system for OPRT requires a minimal amount of carcinoma tissue, making it an easy-to-use assay system to predict sensitivity to 5-FU and its derivatives in gastric carcinoma. There was a significant correlation between tumor growth inhibition rates against the oral administration of oral-uracil/tegafur (UFT) and OPRT enzyme activity in the human cancer xenografts (r2 = 0.574). These results suggest that this newly developed sandwich ELISA system for the quantification of OPRT levels is technically simple, feasible and a useful tool to predict sensitivity to fluoropyrimidine-based anticancer chemotherapy in patients with gastric carcinoma and other cancers.

[Clinicopathological significance of orotate phosphoribosyltransferase in gastric carcinoma].

Orotate phosphoribosyltransferase (OPRT EC 2.4.2.10) is a key enzyme related to the first-step phosphorylation process of 5-fluorouracil. We have recently developed an ELISA system to measure OPRT levels in cancerous tissues. We examined OPRT levels in 75 gastric carcinoma tissues using this ELISA, and the relationships with clinicopathologic factors were evaluated. A total of 75 surgically-resected gastric carcinoma tissues were subjected to the present study. The intratumoral OPRT level was determined by a newly-developed enzyme-linked immunosorbent assay (ELISA). Enzyme activities of OPRT were also determined using a conventional enzyme assay using radiolabeled 5-fluorouracil as a substrate. OPRT levels in gastric carcinoma tissues measured by ELISA were 5.4+/-3.6 ng/mg protein, ranging from 0.2 to 15.7 ng/mg protein. There was a significant correlation between the OPRT level measured by the ELISA and OPRT enzyme activity (y=0.545x - 0.017, r(2)=0.617, p<0.0001). OPRT levels were significantly higher in patients with differentiated type and invasive type of gastric carcinoma, whereas OPRT levels were not associated with the pathological stage of gastric carcinoma. These results suggest that OPRT levels were related to the histopathological characteristics of gastric carcinoma, and may be related to the response to fluoropyrimidine-based anticancer chemotherapy.

[Advancce in laparoscopic treatment for gastric cancer].

Many laparoscopic surgeries for gastric cancer are presented, including D 2 lymphadenectomy, gastrectomy with preservation of vagus nerve and intracorporeal anastomosis after some gastrectomies. The great advances in laparoscopic treatments in gastric cancer are described.

[Establishment of enzyme-linked immunosorbent assay for quantification of orotate phosphoribosyltransferase in gastric carcinoma].

A number of enzymes have been shown to be involved in the process of activation and/or degradation of 5-fluorouracil, and they are potential candidates for predicting factors of chemosensitivity to 5-fluorouracil. Among them, orotate phosphoribosyltransferase (OPRT EC 2.4.2.10) is a key enzyme related to the first-step activation process of 5-fluorouracil and therefore it has been shown to be an important enzyme for the prediction of sensitivity to 5-fluorouracil and its related derivatives. We developed a new enzyme-linked immunosorbent assay (ELISA) system to accurately assess intratumoral activity of orotate phosphoribosyltransferase. A new sandwich ELISA system was established using anti-OPRT polyclonal antibodies obtained from the rabbit immunized with the recombinant human peptides of the OPRT molecule. OPRT levels were measured in 8 human cancer xenografts transplanted in nude mice and 58 gastric cancer tissues using both a newly established ELISA and a conventional enzyme assay using radiolabeled 5-fluorouracil as a substrate. OPRT levels in 8 human cancer xenografts measured by this ELISA were significantly correlated with the OPRT enzyme activities (r2=0.782). Furthermore, OPRT activities measured in 58 gastric cancer tissues by enzyme assay were significantly correlated with those measured by the newly-established ELISA (r2=0.664). The ELISA system developed for the measurement of OPRT required a minimal amount of carcinoma tissue samples, which could be an easy-of-use assay system to predict sensitivity to 5-fluorouracil in gastric carcinoma. These results suggest that this newly-developed sandwich ELISA system for the quantification of OPRT is technically simple, feasible, and may be a useful tool to predict sensitivity to fluoropyrimidine-based anticancer chemotherapy in patients with gastric carcinoma and other cancers.

Abdominal wall abscess associated with perforated jejunal diverticulitis: report of a case.

We report a case of abdominal wall abscess caused by diverticulitis of the jejunum penetrating through the abdominal wall. A 53-year-old Japanese woman visited a local hospital complaining of abdominal pain and a mass in the left lower abdomen. An abdominal computed tomography scan showed a tumor with isodensity in the left lower abdominal wall. Magnetic resonance imaging showed a mass in the abdominal wall with isointensity in the T1-intensified image and high intensity in the T2-intensified images. The mass was heterogeneous inside and protruded partially toward the intraperitoneal cavity. Ultrasound examination showed a heteroechoic mass extending into the intraperitoneal cavity. Laparotomy revealed a tumor in the abdominal wall with a fistulous tract extending to the jejunum. We resected the abdominal wall tumor with partial resection of the small intestine. The resected specimen contained a tumor with a fistulous tract passing through the abdominal wall. Histological examination revealed remarkable infiltration of neutrophils and a bacterial mass in the abdominal wall tumor, with a fistulous tract connected to the area adjacent to the mesenteric border of the jejunum. These findings suggested that diverticulitis of the jejunum had penetrated through the abdominal wall, leading to the formation of an abscess. We report this case to highlight the need for complete gastrointestinal evaluation with gastrointestinal barium studies and imaging analysis to examine extension of intra-abdominal lesions in patients with an unexplained abdominal wall abscess.

Successful downstaging by S-1-based chemotherapy followed by surgical resections for gastric carcinoma with extensive distant lymph node metastasis - report of two cases and a review of cases with surgical resection after downstaging by S-1-based chemotherapy.

We report two cases of gastric carcinoma with successful downstaging using S-1-based chemotherapy followed by surgical resection, which enabled us to confirm the histological effect of chemotherapy. These patients were associated with extensive distant lymph node metastases for which curative resections were unlikely to be performed. We performed anticancer chemotherapy using S-1 with or without concomitant administration of cisplatin in a neoadjuvant setting. After the successful downstaging of these metastatic gastric carcinomas evaluated by imaging analyses, the patients underwent surgical resections. Effect of the chemotherapy was confirmed by the histological analyses. These cases provide further evidence, suggesting that S-1-based chemotherapy enabled downstaging of stage IV gastric carcinoma associated with distant extensive lymph node metastasis and consequently the following possible curative resections. The review of 16 cases of S-1-based chemotherapy followed by surgical resections indicated that, although downstaging may not be expected when N3 lymph node metastases are evident, the S-1-based chemotherapeutic regimens were effective in short cycles for patients in whom potential curative resection is expected. Survival benefit of downstaging followed by surgical resection, however, remains to be further elucidated.

Complete obstruction of the lower common bile duct caused by autoimmune pancreatitis: is biliary reconstruction really necessary?

Recent observations suggest that an immune response is involved in the development of chronic pancreatitis. We report a case of autoimmune pancreatitis in a patient who showed complete obstruction of the lower common bile duct. A 63-year-old man was admitted to a local hospital, complaining of appetite loss and back pain. The patient had obstructive jaundice, and percutaneous transhepatic gallbladder drainage was performed. Fluorography through the biliary drainage catheter showed complete obstruction of the lower common bile duct. The patient had no history of alcohol consumption and no family history of pancreatic disease. Physical examination revealed an elastic hard mass palpable in the upper abdomen. Abdominal ultrasound and abdominal computed tomography (CT) scans showed enlargement of the pancreas head. While autoimmune pancreatitis was highly likely, due to the patient's high serum immunoglobulin level, the possibility of carcinoma of the pancreas and/or lower common bile duct could not be ruled out. Laparotomy was performed, and wedge biopsy samples from the pancreas head and body revealed severe chronic pancreatitis with infiltration of reactive lymphocytes, a finding which was compatible with autoimmune pancreatitis. Cholecystectomy and biliary reconstruction, using choledochojejunostomy, were performed, because the complete bile duct obstruction was considered to be irreversible, due to severe fibrosis. After the operation, prednisolone (30 mg/day) was given orally for 1 month, and the entire pancreas regressed to a normal size. Complete obstruction of the common bile duct caused by autoimmune pancreatitis has not been reported previously; this phenomenon provides an insight into autoimmune pancreatitis and provokes a controversy regarding whether biliary reconstruction is needed for the treatment of complete biliary obstruction caused by autoimmune pancreatitis.