Insidious ocular surface lesion in an 81-year-old woman.

Ocular surface melanoma (OSM) is rare. An 81-year-old Caucasian woman presented with a 4-month history of right eye pain and reduced vision. Histopathological examination of the excisional biopsy identified invasive amelanotic melanoma of the conjunctiva expressing Melan A and SOX10. X-ray of chest, CT of liver and MRI of the brain and orbit did not identify macroscopic metastases. She was given adjuvant topical mitomycin-C 0.04% for four cycles of 2 weeks. Her vision improved and the cornea was clear at 6 months.

Aerobic biodegradation of 4-methylpyridine and 4-ethylpyridine by newly isolated Pseudonocardia sp. strain M43.

A filamentous bacterium capable of utilizing 4-methylpyridine and 4-ethylpyridine as the sole source of carbon, nitrogen and energy was isolated from sludge. The organism, designated as strain M43, clustered most closely with members of the genus Pseudonocardia by 16S rRNA gene sequence analysis. During the degradation of 4-methylpyridine and 4-ethylpyridine, c. 60% of nitrogen in the pyridine ring was released as ammonia. Metabolite analyses showed that 2-hydroxy-4-methylpyridine and 2-hydroxy-4-ethylpyridine were transiently accumulated during the degradation of 4-methylpyridine and 4-ethylpyridine, respectively. Strain M43 was also able to degrade pyridine, 3,4-dimethylpyridine, 4-carboxypyridine and 2-hydroxy-4-methylpyridine. The results indicate that degradation of 4-methylpyridine and 4-ethylpyridine by strain M43 proceeded via initial hydroxylation.

Hydrolyzed molasses as an external carbon source in biological nitrogen removal.

Hydrolyzed molasses was evaluated as an alternative carbon source in a biological nitrogen removal process. To increase biodegradability, molasses was acidified before thermohydrolyzation. The denitrification rate was 2.9-3.6 mg N/g VSSh with hydrolyzed molasses, in which the percentage of readily biodegradable substrate was 47.5%. To consider the hydrolysate as a carbon source, a sequencing batch reactor (SBR) was chosen to treat artificial municipal wastewater. During the 14 days (28 cycles) of operation, the SBR using hydrolyzed molasses as a carbon source showed 91.6 +/- 1.6% nitrogen removal, which was higher than that using methanol (85.3 +/- 2.0%). The results show that hydrolyzed molasses can be an economical and effective external carbon source for the nitrogen removal process.

Paired charge-to-alanine mutagenesis of dengue virus type 4 NS5 generates mutants with temperature-sensitive, host range, and mouse attenuation phenotypes.

Charge-to-alanine mutagenesis of dengue virus type 4 (DEN4) NS5 gene generated a collection of attenuating mutations for potential use in a recombinant live attenuated DEN vaccine. Codons for 80 contiguous pairs of charged amino acids in NS5 were individually mutagenized to create uncharged pairs of alanine residues, and 32 recombinant mutant viruses were recovered from the 80 full-length mutant DEN4 cDNA constructs. These mutant viruses were tested for temperature-sensitive (ts) replication in both Vero cells and HuH-7 human hepatoma cells. Of the 32 mutants, 13 were temperature sensitive (ts) in both cell lines, 11 were not ts in either cell line, and 8 exhibited a host range (tshr) phenotype. One tshr mutant was ts only in Vero cells, and seven were ts only in HuH-7 cells. Nineteen of the 32 mutants were 10-fold or more restricted in replication in the brains of suckling mice compared to that of wild-type DEN4, and three mutants were approximately 10,000-fold restricted in replication. The level of temperature sensitivity of replication in vitro did not correlate with attenuation in vivo. A virus bearing two pairs of charge-to-alanine mutations was constructed and demonstrated increased temperature sensitivity and attenuation relative to either parent virus. This large set of charge-to-alanine mutations specifying a wide range of attenuation for mouse brain should prove useful in fine-tuning recombinant live attenuated DEN vaccines.