Isolation of microorganisms and substances inhibitory to aflatoxin production

Aflatoxins are toxic and carcinogenic secondary metabolites produced by Aspergillus flavus and A. parasiticus. The contamination of crops, feeds, and foods with aflatoxins can have serious effects on the health of humans and animals. Although many studies have been done to develop aflatoxin-control strategies, most are limited in their effectiveness. As part of an effort to develop control procedures, we have devised simple and safe methods that are useful for identifying microorganisms that effectively inhibit aflatoxin production by fungi. These include the microtitre agar plate assay using norsolorinic acid-accumulating mutant fungi, the ultraviolet light photography method using an instant film, the tip culture method, a convenient RNA extraction method for reverse transcription-polymerase chain reaction (RT-PCR) analysis, and other methods. Results of a recent trial have shown that Achromobacter xylosoxidans significantly inhibited aflatoxin production by A. parsiticus, and that the main inhibitory substance produced by the bacterium was cyclo(L-leucyl-L-prolyl). This result confirms that the methods described herein are useful for identifying microorganisms that inhibit aflatoxin production by fungi and could contribute to the development of methods to reduce aflatoxin contamination in commodities.

Mixed-lineage-leukemia (MLL) fusion protein collaborates with Ras to induce acute leukemia through aberrant Hox expression and Raf activation

Mixed-lineage-leukemia (MLL) fusion oncogenes are closely involved in infant acute leukemia, which is frequently accompanied by mutations or overexpression of FMS-like receptor tyrosine kinase 3 (FLT3). Earlier studies have shown that MLL fusion proteins induced acute leukemia together with another mutation, such as an FLT3 mutant, in mouse models. However, little has hitherto been elucidated regarding the molecular mechanism of the cooperativity in leukemogenesis. Using murine model systems of the MLL-fusion-mediated leukemogenesis leading to oncogenic transformation in vitro and acute leukemia in vivo, this study characterized the molecular network in the cooperative leukemogenesis. This research revealed that MLL fusion proteins cooperated with activation of Ras in vivo, which was substitutable for Raf in vitro, synergistically, but not with activation of signal transducer and activator of transcription 5 (STAT5), to induce acute leukemia in vivo as well as oncogenic transformation in vitro. Furthermore, Hoxa9, one of the MLL-targeted critical molecules, and activation of Ras in vivo, which was replaceable with Raf in vitro, were identified as fundamental components sufficient for mimicking MLL-fusion-mediated leukemogenesis. These findings suggest that the molecular crosstalk between aberrant expression of Hox molecule(s) and activated Raf may have a key role in the MLL-fusion-mediated-leukemogenesis, and may thus help develop the novel molecularly targeted therapy against MLL-related leukemia.

Video-assisted skin-sparing breast-conserving surgery for breast cancer and immediate reconstruction with autologous tissue: Clinical outcomes

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Background: This study analyzed clinical results of video-assisted breast-conserving surgery for breast cancer. Methods: Video-assisted breast-conserving surgery is indicated for breast cancer that has not invaded the skin. A skin incision is made at an inconspicuous site. Skin-sparing partial mastectomy was performed endoscopically on 244 patients (stage I, n=94; stage II, n=150). Morbidity, curability and patient satisfaction were analyzed. Results: Skin necrosis was seen in 9 patients. Local recurrence was seen in 13 patients (mean postoperative interval, 65.3 months). Distant metastasis-free survival at 60 months was 93.6% for stage I and 90.5% for stage II. Overall survival was 95.7% for stage I and 96.9% for stage II. Satisfaction with surgery as investigated by questionnaire was “good” for 72.3% of patients. Conclusions: Video-assisted breast-conserving surgery showed no increases in local or distant recurrence and patient satisfaction was high. Video-assisted breast-conserving surgery appears useful for local treatment of breast cancer.

No significant financial relationships to disclose.

Expression of a transgene encoding mutant p193/CUL7 preserves cardiac function and limits infarct expansion after myocardial infarction

BACKGROUND

Transgenic mice expressing the dominant interfering p193 protein in cardiomyocytes (MHC-1152stop mice) exhibit an induction of cell cycle activity and altered remodelling after experimental myocardial infarction (MI).

OBJECTIVE

To determine whether the altered remodelling results in improved cardiac function in the MHC-1152stop mice after MI, as compared with non-transgenic mice.

METHODS

MHC-1152stop mice and non-transgenic littermates were subjected to experimental MI via permanent occlusion of the coronary artery. Infarct size was determined at 24 h and at 4 weeks after MI, and left ventricular pressure-volume measurements were performed at 4 weeks after MI in infarcted and sham-operated animals.

RESULTS

Infarct size in MHC-1152stop mice and non-transgenic littermates was not statistically different at 24 h after MI, as measured by tetrazolium staining. Morphometric analysis showed that infarct scar expansion at 4 weeks after MI was reduced by 10% in the MHC-1152stop mice (p<0.05). No differences in cardiac function were detected between sham-operated MHC-1152stop mice and their non-transgenic littermates. However, at 4 weeks after MI, the ventricular isovolumic relaxation time constant (tau) was decreased by 19% (p<0.05), and the slope of the dP/dt(max)-EDV relationship was increased 99% (p<0.05), in infarcted MHC-1152stop mice as compared with infarcted non-transgenic littermates.

CONCLUSION

Expression of the dominant interfering p193 transgene results in a decrease in infarct scar expansion and preservation of myocardial function at 4 weeks after MI. Antagonism of p193 activity may represent an important strategy for the treatment of MI.

Calcium pyrophosphate dehydrate crystal deposition in the ligamentum flavum of the cervical spine: histopathological and immunohistochemical findings

OBJECTIVE

To investigate the histopathological and immunohistochemical properties of degenerative changes in the ligamentum flavum of the cervical spine with calcium crystal deposition.

METHODS

Sections of the calcified ligamentum flavum harvested from 26 patients who required cervical decompression were examined by scanning electron microscopy (SEM), energy dispersive X-ray microanalysis, immunohistochemical staining [for transforming growth factor (TGF)-Beta, vascular endothelial growth factor (VEGF), Sox9, and Msx2] and terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labelling (TUNEL) method (for cell apoptosis).

RESULTS

Energy dispersive x-ray microanalysis and SEM confirmed the deposited calcium to be calcium pyrophosphate dihydrate (CPPD) crystals. The calcified ligamentum flavum showed disorganisation of the elastic fibre bundles together with increased collagen fibrils in the matrix. Abundant hypertrophic chondrocytes were noted around the calcified lesions, which were strongly immunoreactive to TGF-Beta and VEGF. Staining for Sox9 was positive in metaplastic chondrocytes but negative in hypertrophic chondrocytes. Both chondrocytes and mesenchymal cells were positive for Msx2. TUNEL-positive hypertrophic chondrocytes were significantly more noticeable in nodular than diffusely scattered type of CPPD deposition.

CONCLUSIONS

Calcium crystal deposition in the cervical ligamentum flavum seems to progress with reduction in elastic fibres, increase in collagen fibrils in the matrix, and migration of metaplastic hypertrophic chondrocytes, whose differentiation is controlled by cytokines and transcriptional factors, and potentially regulate crystal formation. The presence of abundant TUNEL-positive hypertrophic chondrocytes around CPPD deposition suggests that materials from apoptotic cells play some role in crystal deposition.

Polymorphisms of HLA genes in Western Javanese (Indonesia): close affinities to Southeast Asian populations

Identification of human leukocyte antigen (HLA) antigens that are known as the highest polymorphic genes has become a valuable tool for tissue transplantation, platelet transfusion, disease susceptibility or resistance, and forensic and anthropological studies. In the present study, the allele and haplotype frequencies of HLA-A, HLA-B, and HLA-DRB1 were studied in 237 unrelated healthy Western Javanese (Indonesia) by the high-resolution polymerase chain reaction-Luminex method. A total of 18 A, 40 B, and 20 DRB1 alleles were identified. The most frequent HLA-A, -B, and -DRB1 alleles were HLA-A*2407 (21.6%), HLA-B*1502 (11.6%) and HLA-B*1513 (11.2%), and DRB1*1202 (37.8%), respectively. The most frequent two-locus haplotypes were HLA-A*2407-B*3505 (7%) and HLA-B*1513-DRB1*1202 (9.2%), and three-locus haplotypes were HLA-A*3401-B*1521-DRB1*150201 (4.6%), HLA-A*2407-B*3505-DRB1*1202 (4.3%), and HLA-A*330301-B*440302-DRB1*070101 (4.2%). HLA allele and haplotype frequencies in addition to phylogenetic tree and principal component analyses based on the four-digit sequence-level allele frequencies for HLA-A, HLA-B, and HLA-DRB1 showed that Western Javanese (Indonesia) was closest to Southeast Asian populations.

Microsurgical excision of multiple clear cell meningiomas of the cauda equina: a case report

We report the case of a 21-year-old woman who presented with a 2-year history of worsening radicular pain on the right leg. The Valsalva manoeuvre provoked radicular pain and radiography showed right-convex 36 degrees scoliosis. Examination showed slight hypoesthesia on the right L3-S1 dermatomes but abnormal muscle power and reflexes. Magnetic resonance imaging identified cauda equina tumours at the L2-3 and L4 levels. The tumours showed heterogeneously isointense signals on T(1)-weighted image, hypointense signals on T(2)-weighted image, and hyperintense signal on gadolinium-enhanced T(1)-weighted sequences. The tumour was microsurgically extirpated from the cauda equina and resected through multiple small laminotomies. Macroscopically, the tumours were poorly encapsulated, hard in consistency, adherent to the adjacent cauda equinas, irregularly shaped like a "horseradish", and yellowish-grey in colour. Histopathological diagnosis was clear cell meningioma.

Final state interaction observed in M(2,3)VV Auger profile of Cu(110)

We have measured the M(2,3)VV Auger spectra of Cu(110) and studied the final state interaction following the Cu 3p core electron excitation. We have observed that the kinetic energy of the M(2,3)VV Auger electron shifts to an energy higher than that of the normal Auger electrons near the Cu 3p threshold, and it converges to the constant kinetic energy of the normal Auger electrons as the excitation energy increases above the Cu 3p threshold. In the excitation energy dependence of the kinetic energies of the M(2,3)VV Auger electrons, we observed step features at the excitation energies corresponding to the 3p core electron excitations to the L(1) and X(1) van Hove singularities in the valence states. The kinetic energy shifts of the M(2,3)VV Auger electrons are reasonably understood by considering the localization of the two-hole Auger final state and the hybridization between Cu 3d states and other valence states.

A unique lantibiotic, thermophilin 1277, containing a disulfide bridge and two thioether bridges

AIMS

To identify the chemical structure of a bacteriocin, thermophilin 1277, produced by Streptococcus thermophilus SBT1277.

METHODS AND RESULTS

Thermophilin 1277 was purified and partial N-terminal sequence analysis revealed 6 unidentified amino acids amongst 31 amino acids residues. A 2.7-kbp region containing the thermophilin 1277 structural gene (tepA) encoding 58 amino acids was cloned and sequenced. Mature thermophilin 1277 (33 amino acids) was preceded by a 25-amino acid putative leader peptide containing a double glycine cleavage motif. Peptide sequence analysis following chemical modification of thermophilin 1277 revealed that the Cys21 and Cys29 residues form a disulfide bridge and that Thr8 or Thr10 forms two 3-methyllanthionines with Cys13 or Cys32 via thioether bridges. Antimicrobial activity was disrupted by ethanethiol or reductive agent treatments, indicating that the internal amino acid modifications are crucial for the activity.

CONCLUSIONS

Thermophilin 1277 from Strep. thermophilus SBT1277 belongs to the class of AII-type lantibiotics that has a disulfide and two thioether bridges.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first report of a lantibiotic produced by a GRAS species of Strep. thermophilus; thermophilin 1277 has a unique structure containing both a disulfide bridge and two thioether bridges that are crucial for its activity.

[Short-term outcome of extracardiac lateral tunnel using the atrial free wall and autologous pericardium]

BACKGROUND

Several modifications to the original Fontan procedure have been proposed in order to decrease postoperative morbidity. Lateral tunnel and extracardiac total cavo-pulmonary connection are 2 such modifications.

PATIENTS

Between August 2005 and December 2005, the extracardiac lateral tunnel procedure was performed in 5 patients. The age at operation ranged from 19 to 59 months (median 24 months) and the weight ranged from 9.2 to 16.1 kg (median 11.4 kg).

RESULTS

There was no mortality. The mean operation time was 466 +/-118 minutes. The mean cardiopulmonary bypass time was 198 +/- 61 minutes. The mean durations of intubation, intensive care unit stay, drainage tube use, and hospital stay were 1 +/- 1, 7 +/- 3, 12 +/- 5 and 30 +/- 2 days, respectively. Postoperative catheterization findings demonstrated that the mean superior venous caval pressure, inferior venous caval pressure, ventricular volume and ventricular ejection fraction were 10.0 +/- 1.4 mmHg, 11.0 +/- 2.4 mmHg, 140 +/- 47% of normal and 58.0 +/- 6.8% , respectively.

CONCLUSIONS

The short-term results of the extracardiac lateral tunnel compared favorably with the results of different types of Fontan operation. In addition this procedure has the potential for growth and anticoagulation therapy is unnecessary.

E-cadherin expression in the subepithelial nevus cells of the giant congenital nevocellular nevi (GCNN) correlates with their migration ability in vitro

BACKGROUND

Giant congenital nevocellular nevi (GCNN) are histologically characterized by the broad distribution of nevus cells in the epidermis and dermis.

OBJECTIVE

To characterize E-cadherin in GCNN and define its role in nevic cell migrations.

METHODS

Twenty-four cases were immunohistochemically examined and in five cases cells were isolated for primary culture for migration assays.

RESULTS

The nevus cells in the superficial region showed the immunoreactivity of E-cadherin in a membranous pattern, but those in the deep part of dermis had little immunoreactivity. Ultra-structural analysis of the superficial nevus cells revealed that E-cadherin immunodeposits in the fibrillar processes around the cell body in a spotted pattern. This distribution pattern is quite different from that in the adherens junction of skin squamous epithelial cells. Boyden chamber experiments were performed using primary cultures of intradermal nevus cells. EDTA pretreatment reduced cell migration to the E-cadherin positive side when the E-cadherin positive population was relatively large in the primary cultures.

CONCLUSIONS

These results indicate that E-cadherin in the nevus cells may affect nevus cell motility rather than intercellular attachment.

Laboratory longitudinal diffusion tests: 1. Dimensionless formulations and validity of simplified solutions

To obtain reliable diffusion parameters for diffusion testing, multiple experiments should not only be cross-checked but the internal consistency of each experiment should also be verified. In the through- and in-diffusion tests with solution reservoirs, test interpretation of different phases often makes use of simplified analytical solutions. This study explores the feasibility of steady, quasi-steady, equilibrium and transient-state analyses using simplified analytical solutions with respect to (i) valid conditions for each analytical solution, (ii) potential error, and (iii) experimental time. For increased generality, a series of numerical analyses are performed using unified dimensionless parameters and the results are all related to dimensionless reservoir volume (DRV) which includes only the sorptive parameter as an unknown. This means the above factors can be investigated on the basis of the sorption properties of the testing material and/or tracer. The main findings are that steady, quasi-steady and equilibrium-state analyses are applicable when the tracer is not highly sorptive. However, quasi-steady and equilibrium-state analyses become inefficient or impractical compared to steady state analysis when the tracer is non-sorbing and material porosity is significantly low. Systematic and comprehensive reformulation of analytical models enables the comparison of experimental times between different test methods. The applicability and potential error of each test interpretation can also be studied. These can be applied in designing, performing, and interpreting diffusion experiments by deducing DRV from the available information for the target material and tracer, combined with the results of this study.