Successful treatment of partial nephrogenic diabetes insipidus with thiazide and desmopressin

OBJECTIVE: To clarify whether combination treatment with desmopressin (DDAVP) and thiazide was clinically effective in a patient with congenital nephrogenic diabetes insipidus (CNDI), we evaluated the treatment in a 7-year-old boy with CNDI who had demonstrated a partial response to DDAVP. METHOD: Both volume of urine and the presence of nocturia were determined during treatment. RESULT: Neither the usual therapy of a low-salt diet and a thiazide nor intranasal therapy with a large dose of DDAVP was effective. However, combination treatment resulted in a decrease in urinary volume and the disappearance of nocturia. CONCLUSION: DDAVP coupled with thiazide may be useful for CNDI in patients who have shown a partial response to DDAVP.     

Immunodominance of conformation-dependent B-cell epitopes of protein antigens

Immunodominance of conformational epitopes over linear ones in four proteins was quantified making use of the B-cell hybridoma technology. The proteins were immunized in their native forms into BALB/c mice, and clonal frequencies of B-cell hybridomas that produce antibodies to the native and denatured forms were determined, using ELISA and immunoblotting. All 16 monoclonal antibodies (mAbs) to Porphyromonas gingivalis fimbria were suggested to recognize conformational epitopes expressed by the oligomer. Ten out of 14 mAbs to Serratia marcescens fimbria and 13 of 15 mAbs to hen lysozyme were also specific to their conformational epitopes. In contrast, all 18 mAbs to a surface protein of Streptococcus mutans, termed PAc, reacted to both the native and denatured forms, thereby indicating the immunodominance of linear epitopes in this protein. The results suggest that B-cell epitopes of proteins possessing stable tertiary or quaternary structures are predominantly expressed by the higher-order structures.     

Apoptosis of Leishmania (Leishmania) chagasi amastigotes in hamsters infected with visceral leishmaniasis

Apoptosis in amastigotes from hamsters infected with visceral leishmaniasis was absent 30-day post-infection but appeared 90-day post-infection in the liver and spleen, as analysed using the TUNEL method. Necrosis was not present in these tissues and the nuclei of macrophages harbouring apoptotic amastigotes were preserved. Amastigote DNA fragmentation was demonstrated using agarose gel electrophoresis. DNA fragmentation was evident 90-day post-infection, coinciding with the occurrence of apoptosis of amastigotes in the tissues. Apoptosis of Leishmania amastigotes in vivo may constitute a mechanism that regulates growth of the parasite population during infection.     

A homolog of Escherichia coli RecA in mitochondria of the cellular slime mold Dictyostelium discoideum

The cellular slime mold Dictyostelium discoideum expresses a gene encoding a 452-amino-acid polypeptide that is 47% identical to Escherichia coli RecA. A recA-deficient E. coli, JE6651, was transformed by pYSN1, which was designed to express the truncated form of the D. discoideum gene, and used in suppression assays. The viability of the transformant, JE6651(pYSN1), increased following UV irradiation or mitomycin C treatment. Phage lambda (red(-) gam(-)), which required RecA activity for DNA packaging, formed plaques on a lawn of JE6651(pYSN1). These results indicate that the gene product has a DNA recombination activity. Fluorescence of D. discoideum protein fused with GFP was detected in mitochondria. The gene disruption mutant was hypersensitive to UV-light (254nm), mitomycin C and H(2)O(2), indicating that D. discoideum recA is important for survival following exposure to DNA damaging agents.     

SSCP Screening of the Dihydropyrimidine Dehydrogenase Gene Polymorphisms of the Japanese Population Using a Semi-automated Electrophoresis Unit

The single-strand conformation polymorphism (SSCP) procedure has been applied in routine testing for hereditary diseases. Temperature, running buffer, gel composition, and fragment length can influence its sensitivity. Mutation detection in the clinical setting depends on the development of automated technology, especially for large genes, such as the dihydropyrimidine dehydrogenase (DPYD) gene, which codes the initial, rate-limiting enzyme in the catabolism of 5-fluorouracil (5FU). The authors have optimized the condition of SSCP with an automated system (GenePhor system, GE Healthcare UK Ltd.) to screen genetic polymorphisms in the DPYD gene. The efficiency of the method was evaluated using 21 positive controls (DNA samples with polymorphisms in the DPYD gene, previously characterized) and DNA samples from 35 Japanese. Results showed that the use of three different running buffers (pH 7.4, 8.3, and 9.0) in combination with other optimized conditions (10% polyacrylamide gel, 60-90 min at constant 900 V at 5 degrees C) resulted in a high polymorphism detection rate (95.3%), which was considered appropriate for routine screening. Therefore, this strategy could be useful for pharmacogenetic studies on 5FU.     

Modified signal-to-noise: a new simple and practical gene filtering approach based on the concept of projective adaptive resonance theory (PART) filtering method

Considering the recent advances in and the benefits of DNA microarray technologies, many gene filtering approaches have been employed for the diagnosis and prognosis of diseases. In our previous study, we developed a new filtering method, namely, the projective adaptive resonance theory (PART) filtering method. This method was effective in subclass discrimination. In the PART algorithm, the genes with a low variance in gene expression in either class, not both classes, were selected as important genes for modeling. Based on this concept, we developed novel simple filtering methods such as modified signal-to-noise (S2N') in the present study. The discrimination model constructed using these methods showed higher accuracy with higher reproducibility as compared with many conventional filtering methods, including the t-test, S2N, NSC and SAM. The reproducibility of prediction was evaluated based on the correlation between the sets of U-test p-values on randomly divided datasets. With respect to leukemia, lymphoma and breast cancer, the correlation was high; a difference of >0.13 was obtained by the constructed model by using <50 genes selected by S2N'. Improvement was higher in the smaller genes and such higher correlation was observed when t-test, NSC and SAM were used. These results suggest that these modified methods, such as S2N', have high potential to function as new methods for marker gene selection in cancer diagnosis using DNA microarray data. AVAILABILITY: Software is available upon request.     

Nocturnal premature ventricular complexes in a young woman with respiratory effort-related arousals

Sleep and Biological Rhythms - We report a young female with snoring and daytime sleepiness who exhibited frequent premature ventricular complexes (PVCs) primarily during non-rapid eye movement...     

Arabidopsis ARGONAUTE7 selects miR390 through multiple checkpoints during RISC assembly

Plant ARGONAUTE7 (AGO7) assembles RNA‐induced silencing complex (RISC) specifically with miR390 and regulates the auxin‐signalling pathway via production of TAS3 trans‐acting siRNAs (tasiRNAs). However, how AGO7 discerns miR390 among other miRNAs remains unclear. Here, we show that the 5′ adenosine of miR390 and the central region of miR390/miR390* duplex are critical for the specific interaction with AGO7. Furthermore, despite the existence of mismatches in the seed and central regions of the duplex, cleavage of the miR390* strand is required for maturation of AGO7–RISC. These findings suggest that AGO7 uses multiple checkpoints to select miR390, thereby circumventing promiscuous tasiRNA production.