RsmA3 modulates RpoS through the RetS-Gac-Rsm signaling pathway in response to H2 O2 stress in the phytopathogen Pseudomonas syringae

Reactive oxygen species are a fatal challenge to the plant pathogenic bacterium Pseudomonas syringae. In this study, we reveal that the global regulatory protein RsmA3 from the RetS-Gac/Rsm signaling pathway modulates RpoS in the early-log growth phase in the P. syringae wild-type strain MB03, thereby regulating oxidative tolerance to H₂ O₂ and ultimately affecting pathogenicity to the host plant. Following increased H₂ O₂ by external addition or endogenous induction by menadione, the resistance of the mutant strain ΔretS to H₂ O₂ is significantly enhanced due to rapid increases in the transcription of Rsm-related non-coding small RNAs (nc sRNAs), a sigma factor RpoS, and H₂ O₂ -detoxifying enzymes. Moreover, the ΔretS mutant is significantly less pathogenic in cucumber leaves. Seven Rsm-related nc sRNAs (namely, rsmZ, rsmY, and rsmX_1-5 ) show functional redundancy in the RetS-Gac-Rsm signaling pathway. External addition of H₂ O₂ stimulates increases in the transcription of both rsmY and rsmZ. Thus, we propose a regulatory model of the RetS-Gac-Rsm signaling pathway in P. syringae MB03 for the regulation of H₂ O₂ tolerance and phytopathogenicity in the host plant.

Carbon Metabolism of a Soilborne Mn(II)-Oxidizing Escherichia coli Isolate Implicated as a Pronounced Modulator of Bacterial Mn Oxidation

Mn(II)-oxidizing microorganisms are generally considered the primary driving forces in the biological formation of Mn oxides. However, the mechanistic elucidation of the actuation and regulation of Mn oxidation in soilborne bacteria remains elusive. Here, we performed joint multiple gene-knockout analyses and comparative morphological and physiological determinations to characterize the influence of carbon metabolism on the Mn oxide deposit amount (MnODA) and the Mn oxide formation of a soilborne bacterium, Escherichia coli MB266. Different carbon source substances exhibited significantly varied effects on the MnODA of MB266. A total of 16 carbon metabolism-related genes with significant variant expression levels under Mn supplementation conditions were knocked out in the MB266 genome accordingly, but only little effect on the MnODA of each mutant strain was accounted for. However, a simultaneous four-gene-knockout mutant (namely, MB801) showed an overall remarkable MnODA reduction and an initially delayed Mn oxide formation compared with the wild-type MB266. The assays using scanning/transmission electron microscopy verified that MB801 exhibited not only a delayed Mn-oxide aggregate processing, but also relatively smaller microspherical agglomerations, and presented flocculent deposit Mn oxides compared with normal fibrous and crystalline Mn oxides formed by MB266. Moreover, the Mn oxide aggregate formation was highly related to the intracellular ROS level. Thus, this study demonstrates that carbon metabolism acts as a pronounced modulator of MnODA in MB266, which will provide new insights into the occurrence of Mn oxidation and Mn oxide formation by soilborne bacteria in habitats where Mn(II) naturally occurs.

Crystal Structure of α-Galactosidase from Thermus thermophilus: Insight into Hexamer Assembly and Substrate Specificity

α-Galactosidase catalyzes the hydrolysis of a terminal α-galactose residue in galacto-oligosaccharides and has potential in various industrial applications and food processing. We determined the crystal structures of α-galactosidase from the thermophilic microorganism Thermus thermophilus (TtGalA) and its complexes with pNPGal and stachyose. The monomer folds into an N-terminal domain, a catalytic (β/α)₈ barrel domain, and a C-terminal domain. The domain organization is similar to that of the other family of 36 α-galactosidases, but TtGalA presents a cagelike hexamer. Structural analysis shows that oligomerization may be a key factor for the thermal adaption of TtGalA. The structure of TtGalA complexed with stachyose reveals only the existence of one -1 subsite and one +1 subsite in the active site. Structural comparison of the stachyose-bound complexes of TtGalA and GsAgaA, a tetrameric enzyme with four subsites, suggests evolutionary divergence of substrate specificity within the GH36 family of α-galactosidases. To the best of our knowledge, the crystal structure of TtGalA is the first report of a quaternary structure as a hexameric assembly in the α-galactosidase family.

Glossogyne tenuifolia (Hsiang-ju) extract suppresses T cell activation by inhibiting activation of c-Jun N-terminal kinase

Background

Glossogyne tenuifolia (GT) (Hsiang-ju) is a Chinese herbal medicine previously exhibited an anti-inflammatory activity. This study aimed to investigate the effect of GT ethanol extract (GTE) on T cell-mediated adaptive immunity.

Methods

Human peripheral blood mononuclear cells (PBMCs) and Jurkat T cells were activated by phytohemagglutinin in the presence of various doses (3.13–50 μg/mL) of GTE. The effect of GTE on T cell activation was examined by a proliferation assay of activated PBMCs and the level of the activation marker CD69 on the surface of activated Jurkat T cells. Apoptosis was determined by propidium iodide staining in hypotonic solution. Signaling pathway molecules were assessed by western blotting.

Results

Glossogyne tenuifolia ethanol extract was demonstrated to inhibit T cell activation, not only in the proliferation of human PBMCs at the concentrations of 12.5, 25 and 50 μg/mL (P = 0.0118, 0.0030 and 0.0021) but also in the CD69 expression in Jurkat cells, which was not due to the cytotoxicity of GTE. The presence of GTE did not change the activity of nuclear factor kappa-light-chain-enhancer of activated B cells or extracellular signal-regulated kinase upon T cell activation. In addition, GTE significantly reduced activation of c-Jun N-terminal kinase (JNK) (P = 0.0167) and p38 (P = 0.0278). Furthermore, decreased JNK activation mediated the preventive effect of GTE on T cell activation-induced cell death (AICD).

Conclusion

Glossogyne tenuifolia ethanol extract inhibited T cell activation of Jurkat cells and freshly prepared human PBMCs due to suppression of JNK activity. Furthermore, GTE inhibited AICD by blocking prolonged JNK phosphorylation in activated T cells. Taken together, the anti-inflammatory effects exerted by GTE were mediated via suppression of JNK phosphorylation in T cell activation.

Electronic supplementary material

The online version of this article (doi:10.1186/s13020-017-0130-4) contains supplementary material, which is available to authorized users.

Phytochemicals from Tradescantia albiflora Kunth Extracts Reduce Serum Uric Acid Levels in Oxonate-induced Rats

Background:

Tradescantia albiflora (TA) Kunth (Commelinaceae) has been used for treating gout and hyperuricemia as folklore remedies in Taiwan. Therefore, it is worthwhile to study the effect of TA extracts on lowering uric acid activity. The hypouricemic effects of TA extracts on potassium oxonate (PO)-induced acute hyperuricemia were investigated for the first time.

Materials and Methods:

All treatments at the same volume (1 ml) were orally administered to the abdominal cavity of PO-induced hyperuricemic rats. One milliliter of TA extract in n-hexane (HE), ethyl acetate (EA), n-butanol (BuOH), and water fractions has 0.28, 0.21, 0.28, and 1.03 mg TA, respectively; and the plasma uric acid (P_UA) level was measured for a consecutive 4 h after administration.

Results:

All four fractions' extracts derived from TA were observed to significantly reduce P_UA compared with the PO group. The EA-soluble fraction (TA-EA) exhibited the best xanthine oxidase (XO) inhibitory activity. Following column chromatography, 12 phytochemicals were isolated and identified from the EA fraction. The IC₅₀ values of isolated phytochemicals indicated that bracteanolide A (AR11) showed the remarkable XO inhibitory effect (IC₅₀ value of 76.4 μg/ml). These findings showed that the in vivo hypouricemic effect in hyperuricemic rats was consistent with in vitro XO inhibitory activity, indicating that TA extracts and derived phytochemicals could be potential candidates as hypouricemic agents.

SUMMARY

Tradescantia albiflora extracts possess in vivo hypouricemic action in hyperuricemic rats

T. albiflora extracts exhibited strong inhibitory activity against xanthine oxidase (XO)

Butenolide may play an important role in XO inhibition

The extract bracteanolide A was demonstrated potent XO inhibitory activity in vitro.

Abbreviations used: TA: Tradescantia albiflora, PO: potassium oxonate, HE: n-hexane, EA: ethyl acetate, BuOH: n-butanol, P_UA: plasma uric acid, XO: xanthine oxidase, MeOH: methanol, IP: intraperitoneal

Effects of Antrodia camphorata extracts on anti-oxidation, anti-mutagenesis and protection of DNA against hydroxyl radical damage

Background

Antrodia camphorata is a geographically special fungus and is one of the precious traditional medicines of Taiwan. A lot of reports have addressed its antioxidant activities and anticancer activities. In order to understand whether these protection effects were resulted from its ability of preventing DNA against hydroxyl radical damage, the A. camphorata extract was used to examine its antioxidant, antimutagenic and DNA-protective activities.

Methods

A. camphorata extract was prepared by extracting the lyophilized powder of A. camphorata mycelium with distilled water. The antioxidative activity of this A. camphorata extract was then evaluated by 2,2-diphenyl-1-picrylhydrozyl (DPPH) radical-scavenging assay, and the antimutagenic activities of the extract against direct mutagen 4-nitroquinoline N-oxide (4NQNO) and indirect mutagen benzo[a]pyrene (B[a]P) were evaluated by Ames test. The effects of the A. camphorata extract in terms of DNA protection against hydroxyl radical damage were also investigated.

Results

It was found that the higher the concentration of A. camphorata extracts, the higher the DPPH radical-scavenging effect. A. camphorata extract at concentrations between 0.625 and 10 mg/ml was found to be neither toxic nor mutagenic. However, the higher A. camphorata concentration (10 mg/ml) used in the test showed higher inhibitory effects on 4NQNO in a dose-dependent manner. The A. camphorata extract also showed reducing and scavenging activities against superoxide anion radical and also exhibited protective effects on DNA against hydroxyl radical-induced damage.

Conclusions

Results suggested that A. camphorata is a non-toxic and novel material with antioxidant, antimutagenic and DNA-protective activities and could be developed into health foods.

Crystal structures and molecular dynamics simulations of thermophilic malate dehydrogenase reveal critical loop motion for co-substrate binding

Malate dehydrogenase (MDH) catalyzes the conversion of oxaloacetate and malate by using the NAD/NADH coenzyme system. The system is used as a conjugate for enzyme immunoassays of a wide variety of compounds, such as illegal drugs, drugs used in therapeutic applications and hormones. We elucidated the biochemical and structural features of MDH from Thermus thermophilus (TtMDH) for use in various biotechnological applications. The biochemical characterization of recombinant TtMDH revealed greatly increased activity above 60 °C and specific activity of about 2,600 U/mg with optimal temperature of 90 °C. Analysis of crystal structures of apo and NAD-bound forms of TtMDH revealed a slight movement of the binding loop and few structural elements around the co-substrate binding packet in the presence of NAD. The overall structures did not change much and retained all related positions, which agrees with the CD analyses. Further molecular dynamics (MD) simulation at higher temperatures were used to reconstruct structures from the crystal structure of TtMDH. Interestingly, at the simulated structure of 353 K, a large change occurred around the active site such that with increasing temperature, a mobile loop was closed to co-substrate binding region. From biochemical characterization, structural comparison and MD simulations, the thermal-induced conformational change of the co-substrate binding loop of TtMDH may contribute to the essential movement of the enzyme for admitting NAD and may benefit the enzyme's activity.

Cloning, overexpression, purification and crystallization of malate dehydrogenase from Thermus thermophilus

Malate dehydrogenase (MDH) has been used as a conjugate for enzyme immunoassay of a wide variety of compounds, such as drugs of abuse, drugs used in repetitive therapeutic application and hormones. In consideration of the various biotechnological applications of MDH, investigations of MDH from Thermus thermophilus were carried out to further understand the properties of this enzyme. The DNA fragment containing the open reading frame of mdh was amplified from the genomic DNA of T. thermophilus and cloned into the expression vector pET21b(+). The protein was expressed in a soluble form in Escherichia coli strain BL21(DE3). Homogeneous protein was obtained using a three-step procedure consisting of thermal treatment, Ni(2+)-chelating chromatography and size-exclusion chromatography. The purified MDH was crystallized and the crystals diffracted to a resolution of 1.80 Å on the BL13C1 beamline of the National Synchrotron Radiation Research Center (NSRRC), Taiwan. The crystals belonged to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 71.3, b = 86.1, c = 118.2 Å. The unit-cell volume of the crystal is compatible with the presence of two monomers in the asymmetric unit, with a corresponding Matthews coefficient VM of 2.52 Å(3) Da(-1) and a solvent content of 51.2%. The crystal structure of MDH has been solved by molecular replacement and is currently under refinement.

Comprehensive histologic analysis of interstitial lipolysis with the 1444 nm wavelength during a 3-month follow-up

A number of near-infrared wavelengths have been proposed and studied for laser lipolysis, but the histologic evaluation of tissue response to laser lipolysis during long-term follow-up has been lacking. A 1444 nm Nd:YAG laser with better absorption in both fat and water has recently attracted attention. The present study was designed to investigate the comprehensive histopathology of 1444 nm Nd:YAG laser-assisted lipolysis at different energy levels during a 3-month follow-up. Laser lipolysis was performed on porcine fat tissue in vivo using a 1444 nm Nd:YAG laser (AccuSculpt®, Lutronic Corporation, Ilsan, Republic of Korea) and the total energies delivered interstitially to 10x10 cm² areas were 750 J, 1500 J, 2250 J, 3000 J, 3750 J, 4500 J, and 5250 J. Biopsy samples were taken and histologically analyzed immediately after biopsy and at 1, 2, 4, and 12 weeks postoperatively. With a fluence setting above 3000J/100 cm², inflammation was severe and remained by the 3-month follow-up, resulting in severe scarring of the fat tissue. Below this energy level, mild lobular inflammation in the early phase biopsy had resolved with no scarring by the 3-month follow-up. No histologic changes in the epidermis or dermal connective tissue were present. This study suggested that controlling the energy level is important for clinical applications of laser lipolysis with no significant complications.

ACE I/D polymorphism in Korean patients with ischemic stroke and silent brain infarction

OBJECTIVES

Angiotensin-converting enzyme (ACE) polymorphism may play a role in stroke and silent brain infarction (SBI) susceptibility, but the results among the populations studied to date have not been consistent. Thus, we investigated the association between ACE genotypes and ischemic stroke and SBI in Korean patients.

SUBJECTS AND METHODS

DNA samples from 237 stroke patients, 264 SBI patients and 234 age-matched controls were amplified using polymerase chain reaction to detect the ACE ins/del (I/D) polymorphism. Genotype was determined by the presence of a 490-bp band (I allele) or a 190-bp band (D allele) in agarose gel electrophoresis.

RESULTS

Odds ratios of the I/D and D/D genotypes and the overall (I/D + D/D) for the I/I genotype were significantly different between stroke patients and normal controls. However, there was no significant difference between patients with SBI and controls.

CONCLUSIONS

This study is the first report of a significant association between ACE polymorphism and ischemic stroke in the Asian population. Although no consistent associations have been found between ACE polymorphism and stroke in the populations studied to date, the ACE polymorphism may be a genetic determinant of ischemic stroke, at least in Korean patients.

Differential expression of manganese superoxide dismutase, copper/zinc superoxide dismutase, and catalase in gastric adenocarcinoma and normal gastric mucosa

AIMS

The biologic significance of antioxidant enzymes (AOEs) in gastric adenocarcinoma is still unclear. The aims of this study was to investigate the differential expression of AOEs in gastric carcinoma cells and non-cancerous counterparts and the relationship with the various clinicopathologic variables in gastric cancer patients.

METHODS

Expression status of MnSOD, Cu/ZnSOD, and catalase was evaluated immunohistochemically in 120 paired gastric cancer and adjacent non-cancerous tissue. The tissues were fixed in absolute methanol immediately after surgical resection and immunohistochemistry was performed by microprobe system using tissuemicroarray slides.

RESULTS

All AOEs revealed moderate to strong immunoreactivity in the parietal and intestinal metaplastic cells. Stromal cells in both cancer and non-cancerous tissue expressed MnSOD and catalase but Cu/ZnSOD. Immunoreactivity of MnSOD and catalase was increased in gastric carcinoma cells compared to their non-cancerous counterparts and revealed an association with intestinal type adenocarcinomas whereas immunoreactivity of Cu/ZnSOD did not reveal significant difference between cancer and non-cancerous mucosal cells.

CONCLUSIONS

Expression of MnSOD, Cu/ZnSOD, catalas in gastric cancer cells and non-cancerous counterparts was different and increased MnSOD and possibly catalase may in part be responsible for the increased risk of intestinal type adenocarcinoma of the stomach.

Structural characterization of sialic acid synthase by electrospray mass spectrometry--a tetrameric enzyme composed of dimeric dimers

Sialic acid synthase (NeuB) encoded by the neuB gene catalyzes the condensation of N-acetylmannosamine and phospho(enol)pyruvate to form N-acetylneuraminic acid. The enzyme is essential for the biosynthesis of polysialic acid, a capsular sugar polymer functioning as a virulent factor and antiphagocytic barrier. This report demonstrates the first characterization on the quaternary structure of NeuB from Escherichia coli (EcNeuB) and Streptococcus agalactiae (SaNeuB) by nanoflow electrospray ionization mass spectrometry (ESI-MS). Under non-denaturing conditions, Tris buffer was observed to induce a higher ratio of tetramer/dimer of NeuB in the ESI mass spectra, providing supportive evidence for the existence of a "structurally-specific" tetramer. The instrument parameters were found to significantly affect the ratio of detected tetramer/dimer in ESI mass spectra. The harshest conditions, including high desolvation voltages and pressure in the collision cell, led to enhanced detection of the 160 kDa tetramer. The prevalence of dimeric form is likely the cause in loss of tetramer stability in gas-phase arising from insufficient collisional cooling, which implies an asymmetric assembly, possibly composed of dimeric dimers. Most interestingly, the hypothesis was further supported by chemical cross-linking of SaNeuB, in which the reaction of shorter linker yielded mainly the dimer whereas that of longer linker produced both dimer and tetramer. Furthermore, the ESI-MS analysis can reflect dramatic change of pH-dependent quaternary structure in association with enzyme activity, suggesting the tetrameric form may be the primary species responsible for the enzyme catalysis.

The structural interpretations of residue Ser297 in catalytic efficiency of Escherichia coli phenylalanine aminotransferase

Escherichia coli phenylalanine aminotransferase (ecPheAT) catalyzes the biosynthesis of phenylalanine and tyrosine. The crystal structure of ecPheAT was determined in our previous study. The comparison of the 3-D structure of several aminotransferases revealed that the residue at position 297 plays an important role in enzyme function. Analysis of activities and kinetic parameters of wild type and mutant ecPheATs suggested that the residue Ser(297) was structurally selected for better catalytic efficiency. Computational modeling of ecPheAT mutants further suggested that Ser in position 297 could make ecPheAT easy with change of conformation from open form to closed form.

Structural characterization of Escherichia coli sialic acid synthase

Sialic acid synthase encoded by the neuB gene of Escherichia coli catalyzes the condensation of N-acetylmannosamine and phosphoenolpyruvate to form N-acetylneuraminic acid. This report demonstrates the first structural information on sialic acid synthase by CD, MALDI-TOF, and chemical cross-linking studies. Also, a specific cleavage by endogenous protease(s) has been identified at Lys(280) of the enzyme (40 kDa) by LC-MS and N-terminal sequencing analyses. The cleavage results in the formation of two inactive fragments of 33 and 7 kDa. The structural analysis indicates that the fragmentation is associated with a significant change of the enzyme from a tetrameric to trimeric form, and alterations in both secondary and native quaternary structures.

Higher incidence of p53 mutation in cervical carcinomas with intermediate-risk HPV infection

OBJECTIVE

Inactivation of p53, either through mutation or interaction with human papillomavirus (HPV) E6 oncoprotein, is a characteristic feature of cervical carcinoma cell lines that have been previously studied. To elucidate the role of p53 in the carcinogenesis of Korean cervical carcinomas, 27 HPV-positive and 13 HPV-negative cervical carcinomas were studied in order to evaluate the status of the p53 gene.

STUDY DESIGN

The HPV status was ascertained by polymerase chain reaction (PCR) amplification using consensus primers designed from the E6 and E7 open reading frames (ORFs). The p53 mutation status was analyzed by direct sequencing of the PCR product in highly conserved exons 5-8.

RESULTS

There was no significant difference in the frequency of the p53 mutation between the HPV-positive and negative cases. All three mutations in the HPV-positive cases were associated with intermediate-risk viruses. The average age of the patients with the p53 mutation was 14 years older than that of patients without the p53 mutation.

CONCLUSION

p53 mutations are higher in the so called intermediate-risk HPV positive than HPV 16 or 18 positive cervical carcinomas.

Hepatocellular carcinoma with lung metastasis in a 9-year-old-boy

Hepatocellular carcinoma (HCC) remains chemoresistant and, therefore, the principal treatment of HCC is surgical resection. After a 9-year-old boy with huge HCC with lung metastasis received the 5 cycles of chemotherapy (cisplatin and Adriamycin), the lung metastasis had been resolved completely and the size of HCC in liver had decreased. Right hepatic trisegmentectomy was performed, and then the additional 3 cycles of chemotherapy was given. Currently, the patient shows no recurrence of HCC 42 months after surgical extirpation.

Regeneration of hyaline cartilage by cell-mediated gene therapy using transforming growth factor beta 1-producing fibroblasts

Transforming growth factor beta (TGF-beta) has been considered as a candidate for gene therapy of orthopedic diseases. The possible application of cell-mediated TGF-beta gene therapy as a new treatment regimen for degenerative arthritis was investigated. In this study, fibroblasts expressing active TGF-beta 1 were injected into the knee joints of rabbits with artificially made cartilage defects to evaluate the feasibility of this therapy for orthopedic diseases. Two to 3 weeks after the injection there was evidence of cartilage regeneration, and at 4 to 6 weeks the cartilage defect was completely filled with newly grown hyaline cartilage. Histological analyses of the regenerated cartilage suggested that it was well integrated with the adjacent normal cartilage at the sides of the defect and that the newly formed tissue was indeed hyaline cartilage. Our findings suggest that cell-mediated TGF-beta 1 gene therapy may be a novel treatment for orthopedic diseases in which hyaline cartilage damage has occurred.

Nasal absorption and biodistribution of plasmid DNA: an alternative route of DNA vaccine delivery

Nasal administration is emerging as a new route of DNA vaccine delivery. We aimed to study the extent of absorption and biodistribution of intranasally administered plasmid DNA. After intranasal administration, the level of plasmid DNA in the serum peaked at 1.5 h. The ratio of the area under the concentration (AUC) after intranasal administration of DNA over the AUC after intravenous administration was 0.14. At 15 min post inoculation, the highest organ distribution was observed in the liver and the cervical lymph nodes showed the highest level among the lymph nodes. At 24 h a higher localization of plasmids to the brain than to the lung and spleen was notable. A significant level of mRNA expression was observed in the lymph nodes. These results suggest that plasmid DNA can be substantially absorbed and distributed to the lymph nodes after intranasal administration, partly explaining the systemic immunogenicity of intranasally administered plasmid DNA vaccines.

Helicobacter pylori-associated iron-deficiency anemia in adolescent female athletes

OBJECTIVE

The objective was to investigate the role of Helicobacter pylori infection in iron-deficiency anemia (IDA) of pubescent athletes.

STUDY DESIGN

Blood sampling and a questionnaire survey were performed on 440 regular high school students and 220 athletes of a physical education high school. Hemoglobin, serum iron, total iron-binding capacity, ferritin, and immunoglobulin G antibody to H. pylori were measured to compare the prevalence of IDA and H. pylori infection in the groups. Nutritional analysis and a questionnaire survey for socioeconomic status were undertaken to compare and control for other risk factors that might influence IDA and H. pylori infection in the groups. In those with IDA coexistent with H. pylori infection, we also determined whether IDA can be managed by H pylori eradication.

RESULTS

The prevalence rates of IDA, H pylori infection, and H. pylori -associated IDA in female athletes were higher than in the control group. The relative risk of IDA was 2.9 (95% CI, 1.5 to 5.6) for those with H. pylori infection. Athletes who exhibited H. pylori -associated IDA showed significant increases in hemoglobin, iron, and ferritin levels after H. pylori eradication. The subjects in the control group who were treated orally with iron alone showed no significant changes.

CONCLUSION

Adolescent female athletes may have development of H. pylori -associated IDA, which can be managed by H. pylori eradication.

A possible relation of the Helicobacter pylori pfr gene to iron deficiency anemia?

BACKGROUND

H. pylori infection is thought to contribute to iron-deficiency anemia, especially during puberty. The ferritin protein Pfr of H. pylori is homologous to eukaryotic and prokaryotic ferritins. The purpose of this study was to analyze the H. pylori pfr status in gastric biopsy specimens according to clinical data, including antral gastritis with or without iron-deficiency anemia.

METHODS

A total of 26 H. pylori-positive patients aged from 10-18 years were categorized into subgroups based on the presence or absence of iron-deficiency anemia. All of them had antral gastritis. Sixteen patients were proved to have iron-deficiency anemia by hematological study, two of which had a duodenal ulcer. The other 10 patients showed normal hematological findings. DNA isolation was performed from each of the gastric biopsy specimens. PCR amplification of the pfr gene coding was done using two sets of primers. The pfr region, 501 bp, was generated by linking the sequences of the two PCR products. The nucleotide and protein sequences were compared between the pfr regions from Korean H. pylori strains and the NCTC 11638 strain, which was obtained from the Genbank. Sequence comparisons were also performed for the pfr regions between the iron-deficiency anemia (+) and (-) groups.

RESULTS

Analysis of the complete coding region of the pfr gene revealed three sites of mutation. The Ser39Ala mutation was found in 100% (26/26), Gly111Asn in 26.9% (7/26), and Gly82Ser in 11.5% (3/26). There were no significant differences in the mutations of the pfr regions between the iron deficiency anemia (+) and (-) groups.

CONCLUSION

The mutation in the pfr gene did not relate with the clinical phenotype, iron deficiency anemia. Further studies are needed on the aspects of host side or other complex factors to elucidate the mechanisms by which the H. pylori infection might lead to iron deficiency anemia.

Metastatic renal cell carcinoma in a meningioma: a case report

Tumor-to-tumor metastasis is rare. We report a case of metastatic renal cell carcinoma in meningioma. A 67-year-old woman presented a two-week history of motor dysphagia and decreased short-term memory. She had undergone a left radical nephrectomy for a renal cell carcinoma 7 years ago, and had not received any adjuvant therapy. MRI disclosed a 3.0 x 3.0 x 3.0-cm sized round tentorial-based extraaxial mass with peritumoral edema in the left posterior temporal lobe. During operation, the tumor was found to be an encapsulated mass firmly attached to the tentorium. Histologically, the tumor was a meningotheliomatous meningioma extensively infiltrated by metastatic renal cell carcinoma, accompanying widespread coagulative necrosis. Immunohistochemical staining for cytokeratin revealed strong positivity only in the renal cell carcinoma component. The patient's postoperative course was uneventful. Post-operative radiation therapy was applied to the whole brain. Three months after operation, the patient developed right hemiparesis and dysphagia. Brain MRI at that time did not reveal recurrence or any other causative lesions, although the whole body scan disclosed uptake at the second lumbar vertebra and rib. The patient refused further treatment.

Biliary lymphoepithelioma-like carcinoma not associated with Epstein-Barr virus

We report the case of a 64-year-old man who presented with a hepatic mass and macronodular cirrhosis. The pathologic findings revealed a lymphoepithelioma-like carcinoma arising in the hepatobiliary tract that was morphologically identical to nasopharyngeal undifferentiated carcinoma. However, this tumor was not associated with Epstein-Barr virus infection in molecular studies. Macronodular cirrhosis associated with hepatitis C virus was present in the background liver.

Thymocytes positively select thymocytes in human system

We previously demonstrated the expression of MHC class II molecules in a significant percentage of human fetal and postnatal thymocytes. These results, at that time, raised the question as to whether the MHC class II molecules on immature thymocytes could actively be involved in the selection of immature T cells. We have developed a human reaggregate culture system to address this issue. Surprisingly, despite the fact that thymic epithelial cells (TECs) have been shown to be a major selecting cell type of positive selection, we were clearly able to see the involvement of MHC class II+ thymocytes during selection process through T-T interaction. In addition, maturation to single positive (SP) cells occurred only in the presence of MHC class II molecules and immature thymocytes were found to be arrested at the double positive (DP) stage of differentiation by blocking of TCR recognition of MHC class II molecules. All these results strongly suggest that human MHC class II+ thymocytes actively participate in the selection of the TCR repertoire, for which TCR recognition of peptide/MHC class II may be an initial determining step.

Optimal primer selection for clonality assessment by polymerase chain reaction analysis. III. Intermediate and high-grade B-cell neoplasms

Previous studies have reported that low-grade B-cell lymphoproliferative disorders have variable B-cell monoclonality detection rates by polymerase chain reaction (PCR) analysis. For instance, monoclonal B-cell populations from chronic lymphocytic leukemia/small lymphocytic leukemia and mantle cell lymphoma are most often readily amplified with a single primer pair, whereas follicular lymphomas and plasma cell neoplasms require alternative strategies to approach these higher diagnostic sensitivity standards. Because most published reports have not focused on the variation in PCR B-cell monoclonality detection among subtypes of intermediate and high-grade B-cell neoplasms, additional information is necessary to determine primer selection strategies and identify problematic tumor subtypes within this group. The current investigation, the third part in a series, was aimed at documenting the efficiency of B-cell monoclonality detection by PCR in 71 aggressive B-cell neoplasms of various types using a comprehensive approach. A predetermined panel of primer sets was used in an algorithmic fashion. Specifically, all samples were analyzed with the standard VH-FRIII/JH assay previously shown to have the highest efficiency of monoclonality detection within low-grade B-cell lymphoproliferative disorders. Negative samples were further evaluated with primer sets in the following order until a positive result was observed, or all primer sets were used: (1) bcl-2/JH, (2) VH-FRI family specific/JH, and (3) VH-FRI consensus/JH. Forty-three (61%) of the 71 B-cell neoplasms evaluated with VH-FRIII/JH showed monoclonal B-cell populations. Sequential use of the three reserve primer sets in samples negative with this initial primer pair resulted in an overall improvement in PCR detection from 61% to 82% (58 of 71 specimens) (P < .001). The VH-FRI family specific assay identified B-cell monoclonality in 11 (73%) of these 15 specimens and was the most productive reserve primer set. Individual categories exhibited the following initial (I) and final (F) PCR detection rates: acute lymphoblastic leukemia/lymphoblastic lymphoma, 11 specimens (I = 91% to F = 91%); small noncleaved cell lymphoma, 14 specimens (I = 79% to F = 86% [P > .25]); diffuse large cell lymphoma, 33 specimens (I = 52% to F= 85% [P < .005]) and large cell, immunoblastic lymphoma, 13 specimens (I = 38% to F = 62% [P < .01]). The authors have shown that comprehensive PCR analysis is capable of detecting B-cell monoclonality in a significant proportion of samples from each subtype of intermediate and high-grade B-cell neoplasm. The VH-FRIII/JH assay was an adequate initial primer set, but required augmentation with the reserve PCR assays to attenuate the false negative rate and improve diagnostic sensitivity. The B-cell clonality PCR assay is optimally used as a screening tool and when used in this fashion, the more laborious and time-consuming restriction fragment-Southern blot hybridization (RF-SBH) method for IgH gene rearrangement detection may be limited to a relatively small proportion of PCR-negative aggressive B-cell neoplasms.

The prognostic significance of c-erbB-2 and p53 protein expressions in gastric carcinoma--a multivariate analysis of prognostic factors

152 curative gastrectomy specimens from patients with gastric carcinoma were examined in an attempt to assess the prognostic value of c-erbB-2 and mutant p53 protein expressions. The labeled streptavidin-biotin method was applied to routinely fixed and paraffin-embedded tissue sections, using the polyclonal and monoclonal antibodies against the c-erbB-2 protein and the mutant form p53 protein, respectively. In this examination, staining of c-erbB-2 protein was found in 9.2% of these carcinomas. The c-erbB-2 stained tumors were significantly associated with the tumors whose diameters were smaller than 5cm, and were more likely to be associated with serosal invasion and nodal involvement than the unstained ones. However, there was little association between staining of c-erbB-2 protein and clinicopathologic findings such as age, sex, location, histology, gross type, lymph node status, depth of invasion, and stage. The survival analysis of 104 patients with stage III gastric carcinoma revealed no significant association between c-erbB-2 staining status and survival duration. The 5-year survival rates of the c-erbB-2 positive group and its negative group were 21% and 28%, respectively. Positive p53 protein expression was observed in 46% of 152 carcinomas. There was no significant association between p53 expression and parameters such as age, sex, location, histology, gross type, and size. The p53 stained tumors were more likely to be associated with lymph node metastasis, serosal invasion than p53 unstained ones; but this did not reach significance. The 5-year survival rates of the p53 positive group and counter part group were 27% and 31%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Pathologic study of mice infected with Rickettsia tsutsugamushi R19 strain

Scrub typhus, an acute febrile infectious disease caused by R. tsutsugamushi, has been reported from various parts of the far east and pacific rim of Asia including Korea. It is well known that all human pathogenic rickettsia share an affinity to endothelial cells of the small blood vessels and evoke vascular inflammation variably associated with a rash, microthrombi, and hemorrhage. We infected the ICR mice by inoculating sublethal doses of R. tsutsugamushi R19 strain intraperitoneally and observed the pathologic changes by time sequence. The histopathologic features of experimentally induced scrub typhus in the mice were generally nonspecific interstitial inflammations characterized by interstitial pneumonitis, periportal inflammation, multifocal hepatic necrosis, interstitial nephritis, sinusoidal engorgement, and lymphohistiocytic cell infiltration in lymph nodes and spleen. Contrary to the general features of other rickettsial diseases, the pathologic process of scrub typhus experimentally induced by R. tsutsugamushi R19 strain mainly involved the interstitial connective tissue but not the blood vessels.

Combined chemotherapy and radiation for bulky stages I-II cervical cancer: comparison of concurrent and sequential regimens

Based on analysis of 5-year survival rates among 386 patients with carcinoma of the cervix treated between 1976 and 1984 at Yonsei University College of Medicine, high risk factors have been defined which identify patients with a poor prognosis when treated with radiation alone. Among patients with FIGO Stages I-II disease, lesions > or = 4 cm were indicative of a higher risk of treatment failure. Between 1984 and 1991, 39 patients with Stages I-II large cell squamous cancers > or = 4 cm in diameter were treated with radiation alone. Between 1984 and 1989, 19 comparable patients were treated with sequential chemotherapy consisting of two or three cycles of cisplatin at 100 mg/m2 and a 5-day infusion of 5-fluorouracil at 1000 mg/m2/24 hr. Between 1988 and 1991, 37 comparable patients were treated with concurrent radiation and one to six cycles of chemotherapy employing the same or equivalent drug and dose schedule. The radiation techniques, dose, and fractionation employed were similar in the three groups. The 30-month survival rate was 100, 89.5, and 79.5% (P < 0.05) following concurrent treatment, sequential treatment, and radiation alone, respectively. Response to chemotherapy administered in cycles was evaluated before instituting radiotherapy in the patients treated with sequential chemotherapy and radiation. In conclusion, the combination of radiotherapy and chemotherapy appeared superior to radiation alone, and the toxicity of combined modality therapy is manageable. Also concurrent chemotherapy may be slightly better than sequential chemotherapy and radiation, and given the lesser overall treatment time and expense, this has become the preferred mode of treatment in our institution.

A monoclonal antibody to common acute lymphoblastic leukemia antigen (CALLA) and its expression on several human tumor cell lines

We describe a newly-made murine monoclonal antibody to the common acute lymphoblastic leukemia antigen (CALLA), named SHB-10. The antigen detected by SHB-10 has a molecular weight of about 105 kDa. This antibody is very similar to that of conventional anti-CD10 Ab on indirect flowcytometric analysis using lymphoid malignant cell lines and peripheral lymphocytes of acute lymphoblastic leukemia (ALL) patients. The binding of anti-CD10 to Daudi cell and peripheral lymphocytes of ALL patients is blocked by SHB-10. Thus this monoclonal antibody is thought to detect the CALLA. The distribution of antigen detected by SHB-10 on several cell lines of neuroectodermal tumor and lymphoid malignancy was analysed and a slight difference in their cell surface expression is observed when compared with that by conventional anti-CD10. Further biochemical analysis is now under way for a better characterization of this antigen.

Poorly differentiated carcinoma of the thyroid retrospective clinical and morphologic evaluation

Five thyroid carcinomas showing clinically aggressive biologic behavior were retrospectively reviewed to evaluate the possible presence of morphologic differences from conventional thyroid carcinomas. They were originally diagnosed as follicular carcinomas, medullary carcinoma, papillary carcinoma, and mixed papillary and medullary carcinoma. There were three males and two females. The age at the time of initial diagnosis ranged from 36 years to 67 years (mean 56 years). The size of the tumor varied from 4.5cm to 10cm (mean diameter 7cm). One patient died of brain metastasis four years after the initial therapy and the other four patients are still alive with local recurrences and/or metastases to bone, spinal cord, lung, and buttock. Histologically these lesions are categorized into two different groups: insular variant and columnar cell variant. Insular variant was characterized by well-defined nests (insulae) that are composed of small, uniform cells, frequent tumor necrosis, and hyalinization of the stroma. Columnar cell variant was characterized by tall columnar cells with marked nuclear statification. All five cases stained positively for thyroglobulin and negatively for calcitonin. With the above clinical and histopathological findings, we interpreted these lesions as a poorly differentiated carcinoma, biologically in an intermediate position between well differentiated and anaplastic carcinomas. The rapid and often fatal outcome associated with these variants of poorly differentiated carcinoma warrants aggressive treatment at the time of diagnosis.

Thyroglobulin synthesis of oxyphilic cells in various types of neoplastic and autoimmune thyroid diseases

To determine the content of thyroglobulin in oxyphilic cells of the thyroid, which have been considered as non-thyroglobulin producing cells, the degree of stainability of the various oxyphilic cells for thyroglobulin was compared with that of non-oxyphilic follicular cells in either same or different lesion. A total of 13 oxyphilic lesions, including three follicular adenomas containing oxyphilic cell nodules, four pure oxyphilic cell adenomas, and six Hashimoto's thyroiditis were compared with 16 of non-oxyphilic lesions such as, seven follicular adenomas, four chronic lymphocytic thyroiditis, and five Graves' disease. Many oxyphilic cells stained positively for thyroglobulin regardless of their morphologic variation, but less intensely than the usual follicular cells in follicular adenomas, chronic lymphocytic thyroiditis, and Graves' disease. The stainability of oxyphilic cells for thyroglogulin did not show any significant correlation with morphologic features, whereas in follicular adenomas, the non-oxyphilic follicular cells forming microfollicles stained less strongly for thyroglobulin than the same cells lining large mature follicles in a reproducible way. With above findings, we concluded that oxyphilic cells maintain the functional activity in terms of thyroglobulin synthesis, although the content of the thyroglobulin is less than that of non-oxyphilic colloid forming follicular cells.

Histopathologic study of the so called 'palpation thyroiditis'

We have reviewed 1066 thyroid lesions and compared the relative incidence of the so called 'palpation thyroiditis' between autoimmune thyroiditis and normal thyroid parenchyme surrounding the nodular thyroid lesion and also discussed the pathogenesis of palpation thyroiditis. The typical histopathologic features of 'palpation thyroiditis' were seen in 275 cases among 467 adenomatous goiters and in none of the autoimmune thyroiditis. We here in this paper suggest that the so called 'palpation thyroiditis' is not merely a secondary phenomenon to mechanical follicular damage by vigorous palpation, but this lesion more likely develops in conditions where certain types of physiologic alteration has occurred in follicular basement membrane, just like a pathogenesis of subacute granulomatous thyroiditis.

Syringomatous adenoma of nipple--a case report

A syringomatous adenoma of the nipple is a benign locally infiltrating neoplasm histologically similar to the syringoma of the skin. Morphologically similar lesions have been described as adenoma of the nipple or florid papillomatosis. Patient was a 33 year old woman who was admitted with a history of bloody nipple discharge from her right breast. With a clinical impression of Paget's disease explorative mastectomy was performed. Microscopically typical tubular and duct like structures with syringomatoid features were present throughout the stroma of the nipple.

An evaluation of frozen section biopsy in 4434 cases

Frozen section diagnosis is a highly useful method of diagnosis. There were 4434 frozen sections, 24 false positive diagnosis, 65 false negative diagnosis and 30 deferred diagnosis. This method achieves the highest accuracy when there is a cooperation between experienced surgeon and reliable and careful pathologist. It is wise to defer the diagnosis of consult to other pathologist in difficult situation.

Development of chronic lymphocytic leukaemia in a case of Sjögren's syndrome with systemic lupus erythematosus

Persistent lymphocytosis and intermittent fever were found in a 68-yr-old Chinese woman 5 yr after the diagnosis of Sjögren's syndrome with systemic lupus erythematosus (SLE). A series of examinations--including virology, bone marrow aspiration and surface markers of lymphocytes--was made to evaluate the nature of the lymphocytosis which had not been found previously. All of the results were consistent with the diagnosis of B-cell chronic lymphocytic leukaemia (CLL). Development of CLL in Sjögren's syndrome has seldom been described before and may be added to other malignancies associated with Sjögren's syndrome.

Insulin receptors on leukemia and lymphoma cells

Tumor cells obtained from leukemia and lymphoma patients were investigated for specific insulin receptors. Using radioactive 125I-labeled insulin, specific insulin binding sites were demonstrated on most acute lymphocytic leukemia (ALL) and acute myelocytic leukemia (AML) cells, including acute promyelocytic leukemia (APL), chronic myelocytic leukemia (CML), and acute monocytic leukemia (AMoL) cells. Insulin receptors were not found on chronic lymphocytic leukemia (CLL) and malignant lymphoma (ML) cells. Specific insulin binding sites were also found on monocytes and thymocytes after treatment with phytohemagglutinin (PHA-P), but not on inactivated tonsil cells, peripheral blood lymphocytes, or thymocytes. There was no inverse correlation between the content of insulin receptors and the basal level of circulating insulin. These data suggest that the insulin receptor may be a new marker of acute leukemia and chronic myelocytic leukemia.

Immunological classification of T-cell acute lymphoblastic leukaemia using monoclonal antibodies

We had been able to classify 70 cases of acute lymphoblastic leukemia (ALL) into different immunological subtypes based on surface marker analysis with the aid of a panel of monoclonal antibodies. The relative proportions of different ALL subclasses appears to be similar to those reported from Europe and the U.S.A. Our results also indicated that monoclonal antibodies OKT11, UCHT-2 and WT1 were very useful in defining pre-T or early T subtypes of ALL. The latter leukaemias lack most maturation-linked T-cell markers but share with the other T-ALL the characteristic of low density or undetectable insulin receptors.