Target degradation specificity of phytoplasma effector phyllogen is regulated by the recruitment of host proteasome shuttle protein

Phytoplasmas infect a wide variety of plants and can cause distinctive symptoms including the conversion of floral organs into leaf-like organs, known as phyllody. Phyllody is induced by an effector protein family called phyllogens, which interact with floral MADS-box transcription factors (MTFs) responsible for determining the identity of floral organs. The MTF/phyllogen complex then interacts with the proteasomal shuttle protein RADIATION SENSITIVE23 (RAD23), which facilitates delivery of the MTF/phyllogen complex to the host proteasome for MTF degradation. Previous studies have indicated that the MTF degradation specificity of phyllogens is determined by their ability to bind to MTFs. However, in the present study, we discovered a novel mechanism determining the degradation specificity through detailed functional analyses of a phyllogen homologue of rice yellow dwarf phytoplasma (PHYLRYD ). PHYLRYD degraded a narrower range of floral MTFs than other phyllody-inducing phyllogens, resulting in compromised phyllody phenotypes in plants. Interestingly, PHYLRYD was able to bind to some floral MTFs that PHYLRYD was unable to efficiently degrade. However, the complex of PHYLRYD and the non-degradable MTF could not interact with RAD23. These results indicate that the MTF degradation specificity of PHYLRYD is correlated with the ability to form the MTF/PHYLRYD /RAD23 ternary complex, rather than the ability to bind to MTF. This study elucidated that phyllogen target specificity is regulated by both the MTF-binding ability and RAD23 recruitment ability of the MTF/phyllogen complex.

Interaction of EXA1 and eIF4E Family Members Facilitates Potexvirus Infection in Arabidopsis thaliana

Plant viruses depend on a number of host factors for successful infection. Deficiency of critical host factors confers recessively inherited viral resistance in plants. For example, loss of Essential for poteXvirus Accumulation 1 (EXA1) in Arabidopsis thaliana confers resistance to potexviruses. However, the molecular mechanism of how EXA1 assists potexvirus infection remains largely unknown. Previous studies reported that the salicylic acid (SA) pathway is upregulated in exa1 mutants, and EXA1 modulates hypersensitive response-related cell death during EDS1-dependent effector-triggered immunity. Here, we show that exa1-mediated viral resistance is mostly independent of SA and EDS1 pathways. We demonstrate that Arabidopsis EXA1 interacts with three members of the eukaryotic translation initiation factor 4E (eIF4E) family, eIF4E1, eIFiso4E, and novel cap-binding protein (nCBP), through the eIF4E-binding motif (4EBM). Expression of EXA1 in exa1 mutants restored infection by the potexvirus Plantago asiatica mosaic virus (PlAMV), but EXA1 with mutations in 4EBM only partially restored infection. In virus inoculation experiments using Arabidopsis knockout mutants, EXA1 promoted PlAMV infection in concert with nCBP, but the functions of eIFiso4E and nCBP in promoting PlAMV infection were redundant. By contrast, the promotion of PlAMV infection by eIF4E1 was, at least partially, EXA1 independent. Taken together, our results imply that the interaction of EXA1-eIF4E family members is essential for efficient PlAMV multiplication, although specific roles of three eIF4E family members in PlAMV infection differ. IMPORTANCE The genus Potexvirus comprises a group of plant RNA viruses, including viruses that cause serious damage to agricultural crops. We previously showed that loss of Essential for poteXvirus Accumulation 1 (EXA1) in Arabidopsis thaliana confers resistance to potexviruses. EXA1 may thus play a critical role in the success of potexvirus infection; hence, elucidation of its mechanism of action is crucial for understanding the infection process of potexviruses and for effective viral control. Previous studies reported that loss of EXA1 enhances plant immune responses, but our results indicate that this is not the primary mechanism of exa1-mediated viral resistance. Here, we show that Arabidopsis EXA1 assists infection by the potexvirus Plantago asiatica mosaic virus (PlAMV) by interacting with the eukaryotic translation initiation factor 4E family. Our results imply that EXA1 contributes to PlAMV multiplication by regulating translation.

Random mutagenesis-based screening of the interface of phyllogen, a bacterial phyllody-inducing effector, for interaction with plant MADS-box proteins

To understand protein function deeply, it is important to identify how it interacts physically with its target. Phyllogen is a phyllody-inducing effector that interacts with the K domain of plant MADS-box transcription factors (MTFs), which is followed by proteasome-mediated degradation of the MTF. Although several amino acid residues of phyllogen have been identified as being responsible for the interaction, the exact interface of the interaction has not been elucidated. In this study, we comprehensively explored interface residues based on random mutagenesis using error-prone PCR. Two novel residues, at which mutations enhanced the affinity of phyllogen to MTF, were identified. These residues, and all other known interaction-involved residues, are clustered together at the surface of the protein structure of phyllogen, indicating that they constitute the interface of the interaction. Moreover, in silico structural prediction of the protein complex using ColabFold suggested that phyllogen interacts with the K domain of MTF via the putative interface. Our study facilitates an understanding of the interaction mechanisms between phyllogen and MTF.

Multicenter prospective trial of total gastrectomy versus proximal gastrectomy for upper third cT1 gastric cancer

BACKGROUND

The appropriate surgical procedure for patients with upper third early gastric cancer is controversial. We compared total gastrectomy (TG) with proximal gastrectomy (PG) in this patient population.

METHODS

A multicenter, non-randomized trial was conducted, with patients treated with PG or TG. We compared short- and long-term outcomes between these procedures.

RESULTS

Between 2009 and 2014, we enrolled 254 patients from 22 institutions; data from 252 were included in the analysis. These 252 patients were assigned to either the PG (n = 159) or TG (n = 93) group. Percentage of body weight loss (%BWL) at 1 year after surgery, i.e., the primary endpoint, in the PG group was significantly less than that of the TG group (- 12.8% versus - 16.9%; p = 0.0001). For short-term outcomes, operation time was significantly shorter for PG than TG (252 min versus 303 min; p < 0.0001), but there were no group-dependent differences in blood loss and postoperative complications. For long-term outcomes, incidence of reflux esophagitis in the PG group was significantly higher than that of the TG group (14.5% versus 5.4%; p = 0.02), while there were no differences in the incidence of anastomotic stenosis between the two (5.7% versus 5.4%; p = 0.92). Overall patient survival rates were similar between the two groups (3-year survival rates: 96% versus 92% in the PG and TG groups, respectively; p = 0.49).

CONCLUSIONS

Patients who underwent PG were better able to control weight loss without worsening the prognosis, relative to those in the TG group. Optimization of a reconstruction method to reduce reflux in PG patients will be important.

Effect of low-intensity pulsed ultrasound stimulation on callus remodelling in a gap-healing model

We evaluated the effect of low-intensity pulsed ultrasound stimulation (LIPUS) on the remodelling of callus in a rabbit gap-healing model by bone morphometric analyses using three-dimensional quantitative micro-CT. A tibial osteotomy with a 2 mm gap was immobilised by rigid external fixation and LIPUS was applied using active translucent devices. A control group had sham inactive transducers applied. A region of interest of micro-CT was set at the centre of the osteotomy gap with a width of 1 mm. The morphometric parameters used for evaluation were the volume of mineralised callus (BV) and the volumetric bone mineral density of mineralised tissue (mBMD). The whole region of interest was measured and subdivided into three zones as follows: the periosteal callus zone (external), the medullary callus zone (endosteal) and the cortical gap zone (intercortical). The BV and mBMD were measured for each zone.

In the endosteal area, there was a significant increase in the density of newly formed callus which was subsequently diminished by bone resorption that overwhelmed bone formation in this area as the intramedullary canal was restored. In the intercortical area, LIPUS was considered to enhance bone formation throughout the period of observation. These findings indicate that LIPUS could shorten the time required for remodelling and enhance the mineralisation of callus.

Randomized controlled trial comparing Billroth-I and Roux-en-Y reconstruction in distal gastrectomy for gastric cancer

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Background: In distal subtotal gastrectomy for gastric cancer, Billroth-I (B-I) reconstruction has been performed predominantly in Japan, while increasing number of surgeons chose Roux-en-Y (R-Y) reconstruction recently. To evaluate the safety and superiority of R-Y we conducted a multi-institutional prospective randomized controlled trial.

Methods: Gastric cancer patients who underwent distal gastrectomy were randomized to B-I or R-Y intraoperatively. The primary endpoint was the ratio of body weight loss 1 year after surgery, the secondary endpoints were the incidence of delayed gastric emptying (DGE) and postoperative morbidity.

Results: Between Aug 2005 and Dec 2008, a total of 332 patients were enrolled and 163 patients were assigned to B-I and 169 patients to R- Y. The patient's characteristics were well balanced between the two groups. The operation time was significantly longer in R-Y than B-I (median 180 min in B-I vs 214 min in R-Y, p < 0.0001). The postoperative morbidity was 14 patients (8.6%) in B-I and 23 (13.6%) in R-Y (p = 0.14), the incidence of DGE was 7 (4.3%) in B-I vs 16 (9.5%) in R-Y (p = 0.06), and the hospital stay after surgery was 14.1days in B-I vs 16.4 days in R-Y (p = 0.02). There was no hospital death in the two groups. The body weight loss at 1 year after surgery compared to preoperation was -5.4kg (-9.1%) in B-I vs -6.2kg (-9.8%) in R-Y (p = 0.11).

Conclusions: The advantage of R- Y reconstruction compared to B-I was not proved in terms of postoperative morbidity either the body weight loss 1 year after surgery.

No significant financial relationships to disclose.

Phase II feasibility study of adjuvant S-1 plus docetaxel for stage III gastric cancer patients after curative D2 gastrectomy (OGSG 0604)

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Background: Although an adjuvant chemotherapy with S-1 has become the standard treatment for stage II-III gastric cancer (GC) patients (pts) after curative D2 gastrectomy in Japan, the survival benefit for stage III pts obtained by S-1 is considered to be modest. S-1 plus docetaxel has shown a good response rate of 56% with prolonged median overall survival (OS) of 14.3 months in pts with advanced GC. This phase II study evaluated the feasibility and safety of adjuvant S-1 plus docetaxel for stage III GC pts after R0 resection. Methods: Patients with curatively resected pathological stage III GC receiving D2 dissection, age 20–80 years, performance status < 1, no prior adjuvant treatment, adequate organ function, and informed consent were given S-1 (80 mg/m2/day) orally for consecutive 2 weeks plus docetaxel (40 mg/m2) intravenously on day 1, repeated every 3 weeks. The treatment was started within 45 days after gastrectomy, and repeated for 4 cycles, followed by S-1 monotherapy until 1 year after surgery. Study endpoints included feasibility of the 4 cycles of S-1 plus docetaxel as primary, and safety, progression free survival (PFS), and OS as secondary. Sample size was set to be 50, which was determined to reject the feasibility of 50% under the expectation of 75% with power of 90% and two-sided α of 5%. Results: Fifty-three pts, 42 males and 11 females with a median age of 65 years, were enrolled between 5/2007 and 8/2008. Pathological stages included IIIA in 36 pts and IIIB in 17 pts. Planned 4 cycles of treatment were delivered to 41 out of 53 pts, with the feasibility of 77.4% (95% CI 63.8–87.7%, P<0.001). Reasons for discontinuation were recurrent cancer in 1 pt, adverse events in 10, and miscellaneous in 1, respectively. Grade 4 neutropenia was observed in 28% of pts with grade 3 febrile neutropenia in 9%. Non-hematological toxicities of grade 3 or more involved fatigue in 6%, anorexia in 9%, and nausea in 6%. No treatment-related deaths occurred. Conclusions: Adjuvant S-1 plus docetaxel was well-tolerated and showed good compliance. Although follow-up is ongoing on survival, this regimen could be a candidate of future phase III trial seeking for the optimal adjuvant chemotherapy for stage III GC pts after curative D2 gastrectomy.

No significant financial relationships to disclose.

Evaluation of clinical significance of 18F-fluorodeoxyglucose positron emission tomography in superficial squamous cell carcinomas of the thoracic esophagus

(18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) is used for pre-treatment staging and evaluation of response to pre-operative therapy in advanced thoracic esophageal cancers. To evaluate the clinical significance of PET diagnosis of superficial thoracic esophageal cancers, FDG-PET was conducted preoperatively in 41 patients with such cancers without pre-operative therapy. We compared the PET diagnosis with clinicopathological findings with respect to both the primary tumor and lymph node (LN) metastasis. Of the 41 superficial thoracic esophageal cancers, 21 (51.2%) were PET positive for primary tumors. Although tumor length and histological type did not correlate with FDG uptake by primary tumors, non-flat (elevated or depressed) tumors showed significantly stronger FDG uptake than flat ones. Of 28 tumors infiltrating the deep submucosal layer, 19 (67.9%) were PET positive, while only two (15.4%) of 13 tumors infiltrating only the mucosa or shallow submucosal layer were PET positive. Manova identified FDG uptake as the only independent risk factor for deep submucosal invasion (odds ratio, 7.407; P = 0.0279). In 13 patients with pathological LN metastasis, although no LN metastasis was detected by FDG-PET, FDG uptake by the primary tumors was the only risk factor for LN metastasis (P = 0.0318). PET-negative tumors tended to reflect longer disease-free survival than PET-positive tumors, although this was not significant. FDG-PET is useful for detecting tumors infiltrating the middle or deep submucosal layer (sm2/sm3), and for predicting LN metastasis in patients with superficial thoracic esophageal cancers. FDG-PET is helpful for decision-making regarding treatment of such patients.

A new method for measurement of bone deformation by echo tracking

No method has been available to noninvasively detect bone deformation or strain under loading in vivo. We focused on ultrasonic measurement of the displacement at a certain point on a bone using the echo-tracking method (ET). To develop a method that can noninvasively detect bone deformation in vivo, a preliminary investigation was performed. We investigated the accuracy of measuring displacement with our echo tracking system by using a flat metal panel and found that the method could measure displacement with a precision of a few microns. A three-point bending test of a porcine tibia with both ends fully constrained was performed to measure bone surface displacement, and simultaneous measurement of the surface strain was done using two strain gauges. The correlation between the displacement measured by ET and the strain gauge readings was completely linear (r=0.999), showing that the method could precisely detect bone deformation. The loads versus displacement curves obtained with cyclic loading were typical hysteresis loops that showed viscoelastic properties of the measured bone. We also improved a multi-ET system capable of simultaneously tracking multiple points to detect deformation of the bone surface. Measurement by this echo tracking system was also compared with strain gauge readings during a three point bending test with both ends of the tibia supported. The linearity of both methods was very high (r=0.998). Our ET method might have considerable potential for noninvasive measurement of bone viscoelasticity and plasticity.

Effect of vascularity on canine distracted tibial callus consolidation

In the consolidation period of distraction osteogenesis, mineralization occurs before corticalization. We hypothesized that the increased rate of bone mineral density correlates to the density of vascularity in the callus. We unilaterally lengthened the tibia in eight adult beagles. After a waiting period of 7 days, tibiae were lengthened for 30 days. After a consolidation period of an additional 60 days, all animals were euthanized. Just before euthanasia, blood vessels were perfused with 50% w/v barium sulfate solution, and soft radiographs of the distracted callus and the control tibiae were taken. Bone mineral density of the regenerated bones was measured preoperatively by quantitative computed tomography on Days 37, 68, and 98. Increases of the percent bone mineral density (from Day 37 to Day 98 and from Day 68 to Day 98) correlated with the blood vessel volume density ratios on Day 98. Our results suggest that preservation of the higher density of blood vessels in the consolidation period could lead to the better mineralization of the distracted callus.

Role of Women in Medicine: A Look at the History, the Present Condition and the Future Status of Women in the Surgical Field, Especially Neurosurgery

We have analyzed the historical background of women's progress in medicine in Japan and the role of female neurosurgeons as models for the next generation. Female neurosurgeons were asked to complete a questionnaire regarding their professional life in detail and the problems they are facing while managing their personal life after getting married and having a child. Some feel that there remain some constraints at work for being a female, due to their male colleagues who are not so understanding in nature. The younger generation is not so keen on joining the neurosurgical branch as their life career due to hard work and complete dedication demanded by neurosurgery. It is not easy for all to manage a neurosurgical career along together with a married life and children. Hence it is now time for those successful female neurosurgeons to become role models. Government can play an important role in these social reforms by coming up with programs to give social security to females and initiate programs for child care for married females pursuing such a demanding profession. Certain measures to encourage females to take up surgery are providing more time by arranging care for babies and families, flexibility in working hours, in addition to having a considerate husband and a considerate chief of department and senior staff. Departmental policies need to be completely impartial and should promote everyone based on their skills and knowledge. Women neurosurgeons need to get together and discuss all these issues so that the younger generation will not hesitate to take up this profession and become stalwarts of neurosurgery like their male counterparts.

Fermentation of Five Sucrose Isomers by Human Dental Plaque Bacteria

Sucrose has five structural isomers: palatinose, trehalulose, turanose, maltulose and leucrose. Although these isomers have been reported to be noncariogenic disaccharides, which cannot be utilized by mutans streptococci, there is no information about their fermentability by other bacteria in dental plaque. The purpose of the present study was to examine whether these isomers were fermented by predominant bacteria in human dental plaque. Clinical bacterial isolates obtained from dental plaque from 3 children aged 22 months to 50 months (146 strains) were inoculated into 3 ml of peptone-yeast extract (PY medium) containing glucose for 1 day, then an aliquot of 20 microl of culture medium was inoculated into 1 ml of PY medium containing 1% (w/v) of the respective test carbohydrates. After incubation for 1 day, the pH values and the optical density at 660 nm of the cultures were measured. Fermentation ability was measured by pH <or=5.5, growth by an OD(660) of >or=0.5. Of the clinical isolates, 33% fermented palatinose, and 69% of these were Actinomyces species. All of the palatinose-fermenting bacterial strains fermented trehalulose, 25% fermented turanose, 70% fermented maltulose and 23% fermented leucrose. We therefore conclude that, in human dental plaque, there are significant numbers of bacteria that are able to ferment sucrose isomers.

Identification of mutans streptococci by restriction fragment length polymorphism analysis of polymerase chain reaction-amplified 16S ribosomal RNA genes

Mutans streptococci are frequently isolated from dental plaque and carious lesions. These bacteria have been identified by conventional methods such as biochemical and serologic tests followed by the isolation of colonies on the mitis-salivarius agar, which are sometimes inconsistent. Recently, species-specific polymerase chain reaction (PCR) has been reported to rapidly identify Streptococcus mutans and Streptococcus sobrinus. However, in the case of identification and classification into several species, e.g. within the group of mutans streptococci consisting of seven species, the identification using species-specific PCR seems somewhat inefficient because of need for the development and preparation of specific primers for each species. Therefore, in this study we developed a simple method using restriction fragment length polymorphism analysis of PCR-amplified 16S ribosomal RNA genes (16S rRNA genes PCR-RFLP) for the identification of seven different species included in the group of mutans streptococci. We amplified 16S rRNA gene sequences from genomic DNA samples by PCR using universal primers and digested the PCR products with the restriction endonucleases, HpaII and HaeIII. HpaII produced six RFLP patterns for eight reference strains, since the patterns for S. sobrinus, Streptococcus downei and Streptococcus ferus were similar. RFLP patterns produced with HaeIII could separate these three species. Furthermore, the RFLP patterns predicted from the 16S rRNA gene sequences in the GenBank database agreed with the actual RFLP patterns produced in the present study. The 16S rRNA sequence comparisons can be used to identify oral mutans streptococci; however, the identification by sequencing is sometimes difficult in large-scale studies and for small laboratories. Therefore, 16S rRNA genes PCR-RFLP, using HpaII and HaeIII, could be an alternative method for the identification of mutans streptococci, and may be applicable for large-scale studies on the cariogenicity of mutans streptococci.

Mucoepidermoid carcinoma of the esophagus treated by endoscopic mucosal resection

Mucoepidermoid carcinoma is a mixed cell tumor with both adenocarcinomatous and squamous components. We report a rare case of superficial mucoepidermoid carcinoma of the esophagus with mucosal gastric cancer. Endoscopic mucosal resection was performed on a 67-year-old man with a slight but defined depressed lesion of the thoracic esophagus and two lesions of mucosal gastric cancer. Histological examination revealed that the lesion of the esophagus was a mucoepidermoid carcinoma and the two lesions of the stomach were well-differentiated adenocarcinoma. Since the mucoepidermoid carcinoma had only slightly invaded the submucosal layer, it was thought to arise from the ductal epithelium of the esophageal gland or the stratified squamous epithelium of the esophagus. Radiation therapy with a total dose of 60 Gy was performed and there has been no recurrence or metastasis to other organs during 36 months of follow-up.

Nested PCR for detection of mutans streptococci in dental plaque

AIMS

Mutans streptococci such as Streptococcus mutans and Streptococcus sobrinus have been implicated in human dental caries. In an attempt to develop a rapid and sensitive method for detecting Strep. mutans and Strep. sobrinus in dental plaque, a nested PCR amplification based on the 16S rRNA gene was employed.

METHODS AND RESULTS

A universal set of PCR primers for bacterial 16S rRNA gene was introduced for the first PCR, and then two sets of primers specific for the 16S rRNA gene sequences of either Strep. mutans or Strep. sobrinus were used for the second PCR. Eighteen plaque samples were analyzed, and a nested PCR was shown to be more sensitive for detecting Strep. mutans and Strep. sobrinus than direct PCR.

CONCLUSIONS, SIGNIFICANCE AND IMPACT OF THE STUDY

The 16S rRNA gene-based nested PCR method is a rapid and sensitive method for the detection of mutans streptococci, and may also be suitable for carrying out large-scale studies on the cariogenicity of mutans streptococci.

Clinical features of symptomatic Rathke's cleft cyst

To investigate the clinical features of Rathke's cleft cysts (RCCs), we retrospectively analyzed 15 cases with histologically confirmed RCCs. All patients underwent formal testing of visual field, endocrinological evaluation and magnetic resonance imagings. As overall presenting symptoms, endocrine disturbance was the most common symptoms, followed by visual disturbance and headache. Among the endocrine disturbances based on adenohypophysial dysfunction, hyperprolactinemia was most common. Considering the size of RCCs, RCCs could induce hyperprolactinemia only when the cysts became large enough to compress the infundibular system. Our series showed relative high incidence of pituitary dwarfism and diabetes insipidus (DI). These facts indicated that RCCs could evoke hyposecretion of growth hormone in young patients and DI in aged patients by direct compression of the pituitary gland in the early stage of progression. All cases who had headache had no other symptoms. We could not prove the evidence that RCCs could induce headaches in these cases. This might be suggested that headache could not be a sole symptom in cases of RCCs.

Binding characteristics of bovine lactoferrin to the cell surface of Clostridium species and identification of the lactoferrin-binding protein

The binding characteristics of bovine lactoferrin (bLf) to cells of the Clostridium species were observed by using a horseradish peroxidase-bLf conjugate. A bLf-binding protein (BP) having a relative molecular mass of about 33 kDa was confirmed in the surface layer components from 7 strains of the Clostridium species. The binding of the conjugate to bLf-BP or C. perfringens was strongly blocked by intact Lfs, lysine or arginine residues modified bLf, and deglycosylated bLf, but was not by other milk proteins or by the constituent sugars of glycan. Bacterial growth was inhibited by bLf, but was slightly inhibited by lysine residues modified bLf or deglycosylated bLf. Lactoferricin B did not block the binding of the conjugate, but strongly inhibited the bacterial growth. This suggests that the lysine or arginine residues and glycan of bLf hardly participated in binding bLf to the bacterial cells, but that the amino acid residues and glycan played an important role in inhibiting the growth of bacteria.

Binding of lactoferrin to bacterial cells of the Clostridium species and their agglutination

Cell agglutination in cell suspensions of 10 strains of Clostridium by lactoferrin (Lf) was observed by obtaining the ratio of increased absorbance (RIA) at 450 nm. The RIA values were very different among the species, being higher in the cell suspensions with bovine Lf (bLf) than in those with human Lf. The binding ability of bLf to the bacterial cells was also observed by an enzyme-linked ligand-binding assay, using the conjugate of iron-free or iron-saturated bLf with horseradish peroxidase (HRPO). The binding ability of bLf was very different among the 10 species, and showed a significant correlation with the cell agglutination of each strain. bLf formed a complex with the cells of C. perfringens, did not dissociate in 2 M NaCl or 4 M urea, but did dissociate in 1 M KSCN. These results suggest that the agglutination of cells of the Clostridium species by bLf is probably caused by the cooperative action of at least electrostatic and hydrophobic interactions between bLf and certain components of the cell surface.

Differentiation of oral Actinomyces species by 16S ribosomal DNA polymerase chain reaction-restriction fragment length polymorphism

16S rDNA polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to generate restriction profiles of the reference strains, including the American Type Culture Collection type strains, of oral Actinomyces spp., i.e., A. israelii, A. gerencseriae, A. naeslundii genospecies 1 and 2, A. odontolyticus, A. meyeri and A. georgiae, and 23 Actinomyces strains isolated from human dental plaque. The 16S rRNA gene sequences from isolated genomic DNA samples were amplified by PCR. The PCR products were purified and characterized by single digestion with four restriction endonucleases, i.e., MnlI, HaeIII, CfoI, or HpaII. Among them, MnlI was found to discriminate the respective reference strains. The clinical isolates were assigned to one of the species, i.e., A. gerencseriae, A. naeslundii genospecies 1 and 2 and A. odontolyticus, on the basis of their restriction profiles by single digestion with MnlI. Thus, 16S rDNA PCR-RFLP, using MnlI, is a rapid and reliable method for the differentiation of oral Actinomyces spp.

Restriction fragment-length polymorphism analysis of 16S rDNA from oral asaccharolytic Eubacterium species amplified by polymerase chain reaction

Restriction fragment-length polymorphism (RFLP) analysis of 16S rDNA amplified by polymerase chain reaction was used to generate restriction profiles of the type strains of oral asaccharolytic Eubacterium species, that is, Eubacterium brachy, Eubacterium exiguum, Eubacterium lentum, Eubacterium minutum, Eubacterium nodatum, Eubacterium saphenum, Eubacterium timidum and 33 asaccharolytic Eubacterium strains isolated from oral sites. The 16S rRNA gene sequences from isolated genomic DNA samples were amplified by polymerase chain reaction (PCR). PCR products were purified and characterized by single digestions with 7 restriction endonucleases. Among the 7 endonucleases, HpaII was found to discriminate the respective reference strains. Twenty-three isolates, out of 33, were assigned to one of the reference species, on the basis of their restriction profiles by digestion with HpaII. The remaining 10 isolates could not be assigned to any of the established species and constituted 4 distinct groups, each of which may be a new species.

Differentiation of Veillonella atypica, Veillonella dispar and Veillonella parvula using restricted fragment-length polymorphism analysis of 16S rDNA amplified by polymerase chain reaction

Veillonella atypica, Veillonella dispar and Veillonella parvula cannot be reliably distinguished by conventional phenotypic tests, including the API ZYM test. In this study, restricted fragment-length polymorphism (RFLP) analysis of 16S rDNA amplified by polymerase chain reaction (PCR) was used to generate restriction profiles of the type strains of V. atypica, V. dispar and V. parvula and 20 Veillonella strains isolated from oral sites. 16S rRNA gene sequences from isolated genomic DNA samples were amplified by PCR. PCR products were purified and characterized by single digestion with 13 restriction endonucleases. Among them, Mn/I was found to discriminate the respective reference strains, and the clinical isolates were assigned to one of the three species on the basis of their restriction profiles by digestion with Mn/I. Thus, RFLP analysis of PCR-amplified 16S rDNA, using Mn/I, is a rapid and reliable method for the differentiation of V. atypica, V. dispar and V. parvula.

PCR-restriction fragment length polymorphism analysis of genes coding for 16S rRNA in Veillonella spp

Restriction fragment length polymorphism analysis of PCR-amplified 16S ribosomal DNA (16S rDNA PCR-RFLP) was used to generate restriction profiles of the American Type Culture Collection type strains of the genus Veillonella, i.e., V. atypica, V. caviae, V. criceti, V. dispar, V. parvula, V. ratti, and V. rodentium. Whole-cell protein profiles were obtained by sodium dodecyl sulfate-polyacrylamide gel electrophoresis for comparative purposes. The 16S rRNA genes were amplified by PCR, and RFLP analysis of the 16S rDNA was performed with MnlI and Sau3AI. MnlI produced six RFLP patterns for seven type strains, since the patterns for V. atypica and V. caviae were the same. RFLP patterns with Sau3AI could distinguish between V. atypica and V. caviae. The type strains of Veillonella species were easily distinguished by 16S rDNA PCR-RFLP.

In vitro proteolytic processing and activation of the recombinant precursor of El Tor cytolysin/hemolysin (pro-HlyA) of Vibrio cholerae by soluble hemagglutinin/protease of V. cholerae, trypsin, and other proteases

Vibrio cholerae produces a cytolytic toxin named El Tor cytolysin/hemolysin which is encoded by the hlyA gene. This cytolysin is produced as a 79-kDa precursor form (pro-HlyA) into the culture supernatant after cleavage of the signal peptide of the hlyA product (prepro-HlyA). The pro-HlyA is then processed to a 65-kDa mature cytolysin (mature HlyA) after cleavage of the 15-kDa N-terminal peptide (pro region) of the 79-kDa precursor, usually at the bond between Ala-157 and Asn-158. We investigated whether proteases could process the recombinant 79-kDa pro-HlyA to the 65-kDa mature HlyA. We observed that the soluble hemagglutinin/ protease (HA/protease; a major protease of V. cholerae), trypsin, alpha-chymotrypsin, subtilisin BPN', papain, and thermolysin all processed the pro-HlyA to the 65-kDa mature form of the protein. Along with this, the protease-processed HlyA showed drastically increased hemolytic activity. The N-terminal amino acid of the mature form of cytolysin generated by HA/protease was Phe-151, and that due to trypsin was Ser-149. Other proteases also cleaved the pro-HlyA at a nearby site, between Leu-146 and Ser-153, and all the processed cytolysins showed increased hemolytic activity. These data suggest that the active El Tor cytolysin of V. cholerae could be derived from the C-terminal region of a pro-HlyA following proteolytic cleavage of the bonds in the vicinity of Leu-146 to Asn-158 by any of a wide variety of proteases.

Monoclonal antibody developed against a hemolysin of Bacillus thuringiensis

A total of five hybridoma cell lines that produced monoclonal antibodies (MAb) against a hemolysin (Bt-hemolysin) produced by Bacillus thuringiensis were established and characterized. All of these monoclonal antibodies reacted similarly not only to Bt-hemolysin but also to a hemolysin (Bc-hemolysin) produced by B. cereus, suggesting that the two hemolysins are immunologically indistinguishable. The MAb developed in this study was also successfully applied for rapid and simple purification of both Bt- and Bc-hemolysins by immunoaffinity column chromatography. The partial N-terminal amino acid sequence of the purified hemolysins was determined to be Ile-Glu-Gln-Thr.

Ceruloplasmin concentration in human colostrum and mature milk

The concentration of ceruloplasmin (CP) in human milk was obtained by measuring the increased absorbance of a solution containing apotransferrin and Fe2+ at 460 nm after adding the milk. The CP concentrations in colostrum and mature milk at less than 1 month after parturition were 4.45 +/- 1.23 mg and 4.09 mg +/- 1.47 mg/100 ml, respectively. In mature milk after more than one month, the CP concentration had decreased to 1.72 +/- 0.91 mg/100 ml.

Interaction of lactoferrin with ascorbate and the relationship with bleomycin-dependent DNA damage

The interaction between bovine lactoferrin (bLf) and ascorbate (Asc) was investigated through malondialdehyde (MAD) formation in a solution containing DNA, bleomycin (BLM), and Fe2+ or Asc. The inhibition by bLf on MDA formation in the presence of Asc was not changed even by adding carbonate or oxalate ions to the solution. The percentage inhibition by the hydrolysates of bLf treated with pepsin, trypsin, and both enzymes on MDA formation was almost the same as that by the untreated bLf in the presence of Asc. The inhibition of MDA formation also occurred with the filtrate obtained from a solution containing bLf and Asc, but not with that from a solution of bovine serum albumin and Asc. The interaction of bLf and Asc was observed by gel filtration in a Sephadex G75 column. The binding amount of Asc was estimated to be 87 mol per mole of bLf.

[ACTH producing pituitary adenoma with multiple intracranial metastases and spinal dissemination]

A 34-year-old male developed multiple intracranial and intraspinal metastases from an invasive ACTH secreting pituitary adenoma. He was initially admitted to our hospital complaining of visual loss 10 years ago, presenting a pituitary tumor with suprasellar extension. At first, transsphenoidal surgery was performed, and histological finding was pituitary apoplexy. He developed recurrence of the tumor 2 times. At the second, third and fourth operation, the histological finding was an ACTH secreting pituitary adenoma with atypia. Metastases within the central-nervous system of pituitary adenoma is a rare entity and only 21 cases have been published. A review of previously published cases follows.

A case of Sjögren's syndrome complicating immune-mediated aplastic anaemia

A 78-year-old Japanese woman with Sjögren's syndrome complicating immune-mediated aplastic anaemia is described. A diagnosis of aplastic anaemia was made from severe pancytopenia with hypoplastic marrow. Laboratory studies suggested an association of bone marrow suppressive T-lymphocytes with the pathogenesis of aplastic anaemia. Following the administration of mepithiostan and prednisolone, pancytopenia improved gradually. Two years after the onset of aplastic anaemia, Raynaud's phenomenon developed and examinations revealed the existence of keratoconjunctivitis sicca and anti-SSA/Ro and anti-SSB/La antibodies.

Identity of hemolysins produced by Bacillus thuringiensis and Bacillus cereus

A hemolysin (Bt-hemolysin) produced by Bacillus thuringiensis var. kurstaki HD-1 producing crystalline toxin(s) was purified by successive treatments of ammonium sulfate (45-65%) and column chromatography using DEAE-cellulose, Sephadex G-75 and KB-002 (a hydroxyapatite column for fast protein liquid chromatography). A hemolysin (Bc-hemolysin) produced by B. cereus HG-6A was also purified by the same procedure. The purified Bt-hemolysin and Bc-hemolysin, both of which are thiol-activated hemolysins, were biologically, physicochemically and immunologically identical. These findings provide further evidence of the similarity of B. thuringiensis, which is being used as a biological insecticide, to B. cereus, a toxigenic organism of food poisoning.

[Gliosarcoma with multiple extracranial metastases. Case report]

A 68-year-old male was hospitalized because of headache, nausea, and disturbance of consciousness. Neurological examination on admission disclosed somnolence, disorientation, marked neck stiffness, papilledema, and quadriparesis. Computed tomography (CT) scanning demonstrated a round mass with marked contrast enhancement in the right sylvian fissure and small contrast-enhanced masses in the interpeduncular, quadrigeminal and ambient cisterns. CT also showed marked peritumoral edema, a midline shift, and hydrocephalus. The patient's consciousness level and respiration deteriorated 3 days after admission and a craniotomy was performed. The tumor, which was well demarcated, firmly attached to the sphenoidal ridge, and grossly appeared to be a meningioma, was totally removed. Histologically, the tumor had two well defined components, glioblastoma and fibrosarcoma. The patient underwent ventriculoperitoneal shunting, chemotherapy, and radiotherapy after surgery, but the primary tumor soon recurred, with scalp metastasis, and he died 5 months postoperatively. Autopsy revealed metastases to the liver, spleen, and spinal cord. The histogenesis of this mixed tumor and the mechanism of extracranial metastasis are discussed, and the literature is reviewed.