[A Quercetin-Based Fluorescent Probe for the Recognition of Fluorid Ions].

Quercetin (Q) is one of the most common flavonoids present in roots, stems, leaves, flowers and fruits of most plants. In this study, a quercetin-based fluorescent probe for detecting fluorid ions had been proposed. With good selectivity and sensitivity for fluorid ions, Q-based fluorescent probe was easier to prepare, more eco-friendly and more innoxious compared with traditional fluorescent probe obtained by organic chemistry synthesis operation. There was a major fluorescence emission peak at 500 nm for Q in dimethyl sulfoxide (DMSO) when the excitation wavelength was 390 nm. The changes of fluorescence spectra were investigated before and after adding different anions into Q solution. The fluorescence emission intensity of Q even had no change when adding Cl-，Br-，I-，ClO-4，H2PO-4, respectively. While adding fluorid ions, the fluorescence emission intensity of Q was decreased obviously, which suggested fluorid ions could induce fluorescence quenching of Q in DMSO. And the fluorescence emission intensity of Q-F- system had almost no significant change when adding other anions (Cl-，Br-，I-，ClO-4，H2PO-4), which meant the progress for detecting fluorid ions didn't be affected by other anions, and Q showed a good selectivity for fluorid ions. The fluorescence titration spectra showed that the fluorescence emission intensity of Q was decreased with the increase of concentration of fluorid ions, and they were in concentration-dependent manner. The fluorescence titration curve exhibited that the Q as fluorescent probe can be applied to the quantification of fluorid ions with a good linearity (R2=0.991), linear range of 1.0～8.0×10-6 mol·L-1 and the detection limit of 1.0×10-7 mol·L-1. Not only the changes appeared in fluorescence spectra, but also the changes appeared in UV-visible spectra, compared with Q absorption spectrum, the location of band at 375 nm had no change after adding Cl-，Br-，I-，ClO-4，H2PO-4, respectively. However, when adding fluorid ions, the band at 375 nm was shifted to 394 nm, and the color of the solution was changed into dark yellow, which revealed the interactions between Q and fluorid ions. The probable mechanism of fluorid ions inducing fluorescence quenching of Q was obtained with 1H NMR spectrum and the changes of fluorescence emission intensity of Q-F- system in different polar solvents (DMSO containing different concentration of water). The interaction mode about Q and fluorid ions in DMSO was related with hydrogen bond. Both experiments suggested that the possible recognition mechanism on fluorid ions was: fluorid ions were destroyed or weakened by original hydrogen bonds, and were promoted charge transfer within quercetin molecule, which resulted in fluorescence intensity decreasing of quercetin. This method was successfully applied in detecting fluorid ions of samples in DMSO with good recovery.

Complex phenotype in Fanconi renotubular syndrome type 1: Hypophosphatemic rickets as the predominant presentation.

GATM-related Fanconi renotubular syndrome 1 (FRTS1) is a form of renal Fanconi syndrome (RFS), which is a disorder of solute and water reabsorption caused by defects in the function of the entire proximal tubule. Recent findings reveal the molecular basis of FRTS1: Intramitochondrial fiber aggregation triggered by mutant GATM provides a starting point for proximal tubule damage and drives disease progression. As a rare and newly recognized inherited kidney disease, the complex manifestations of FRTS1 are easily underdiagnosed or misdiagnosed. We discuss the complex phenotype of a 26-year-old woman with onset in infancy and a long history of hypophosphatemic rickets. We also identified a novel heterozygous missense variant in the GATM gene in this patient. The novel variant and phenotype we report expand the disease spectrum of FRTS1. We recommend screening for GATM in children with RFS, especially in patients with resistant rickets who have previously had negative genetic testing. In addition, we found pathological deposition of mutant GATM proteins within mitochondria in the patient's urinary sediment cells by a combination of electron microscopy and immunofluorescence. This unique urine cytology experiment has the potential to be a valuable tool for identifying patients with RRTS1.

[Primary drug resistance of HIV-1 infected men who have sex with men in Shenzhen, China].

OBJECTIVE: To evaluate the status of drug resistance among treat-naive HIV-1 infected men who have sex with men (MSM) in Shenzhen during the period of 2008 - 2010. METHODS: Plasma samples of 227 treatment-naive HIV-1 infected MSM were collected in Shenzhen. HIV-1 pol genes (RT and PR) were amplified by nested-polymerase chain reaction (PCR) from RNA. Phylogenetic and drug resistance analyses were performed on the nucleotide sequence data. RESULTS: A total of 164 pol gene sequences were amplified. The prevalence of primary genotypic drug resistance was 14.6%. The overall prevalence of drug-resistant mutations was 22.6%, corresponding to 8.54% for protease inhibitors (PI) minor drug resistance mutation, 1.22% for nucleotide reverse transcriptase inhibitors (NRTI) drug resistance mutation and 13.41% for non-nucleotide reverse transcriptase inhibitors (NNRTI) drug resistance mutation. The prevalence of drug-resistant mutations was 30.88% for CRF01_AE strain and 19.23% for B strain. CONCLUSION: The prevalence of drug resistance is relatively moderate in the treat-naive HIV-1 infected MSM in Shenzhen. The prevalence of drug-resistant HIV-1 among MSM in Shenzhen should raise a high alert.

Colon cancer bears overexpression of OTUB1.

OBJECTIVE: OTUB1 is a member of deubiquitinating enzymes; however, its expression and function in colon cancer are still unclear. The present study aimed at investigating the expression of OTUB1 in colon cancer and the relationship between the expression and some clinicopathologic parameters. METHODS: Immunohistochemistry and quantitative real-time PCR were carried out in selected colon cancer and normal mucosa tissues. RESULTS: The expression of OTUB1 protein in the colon cancer was significantly higher than normal mucosa, and the OTUB1 mRNA in colon cancer was also 3.15-fold higher than the normal mucosa. The higher expression of OTUB1 in colon cancer was related with tumor size, differentiation and lymph node metastasis. CONCLUSIONS: OTUB1 may play an important role in colon cancer development and metastasis.