Human papillomavirus testing and cytology using physician-collected uterine cervical samples vs. self-collected vaginal samples and urine samples.

BACKGROUND: Human papillomavirus (HPV) testing using self-collected vaginal samples and urine samples is convenient and effective for improving the screening rate. But, to serve as an alternative cervical cancer screening technique, such tests must offer sensitivity equivalent to the HPV testing of physician-collected cervical samples. To examine the effectiveness of HPV testing using self-collected samples and urine samples, we compared the results of HPV testing using these samples with those of HPV testing using physician-collected samples and cytological examinations. METHODS: The study population included 300 women (age: 20-50 years) with abnormal cervical cytology. The results of HPV testing using self-collected samples and urine samples and physician-collected samples and cervical cytology were compared. RESULTS: For all HPV types, the κ-value was 0.773 for physician- and self-collected samples and 0.575 for physician-collected and urine samples. The κ-value for HPV type 16-positive samples was 0.988 for physician- and self-collected samples and 0.896 for physician-collected and urine samples. The κ-value for HPV type 18-positive samples was 0.856 for physician- and self-collected samples and 0.831 for physician-collected and urine samples. For other HPV types, the value was 0.809 for physician- and self-collected samples and 0.617 for physician-collected and urine samples. CONCLUSIONS: The obtained results were consistent between physician- and self-collected samples as well as between physician-collected and urine samples. Considering that the agreement rate was particularly high for the high-risk HPV types 16 and 18, HPV testing using physician-collected samples, self-collected samples, and urine samples was equally effective for the types with high carcinogenicity.

Structural and molecular basis for hyperspecificity of RNA aptamer to human immunoglobulin G.

Potential applications for functional RNAs are rapidly expanding, not only to address functions based on primary nucleotide sequences, but also by RNA aptamer, which can suppress the activity of any target molecule. Aptamers are short DNA or RNA folded molecules that can be selected in vitro on the basis of their high affinity for a target molecule. Here, we demonstrate the ability of RNA aptamers to recognize--and bind to--human IgG with high specificity and affinity. An optimized 23-nucleotide aptamer, Apt8-2, was prepared, and was shown to bind to the Fc domain of human IgG, but not to other IgG's, with high affinity. Apt8-2 was observed to compete with protein A, but not with the Fcgamma receptor, for IgG binding. NMR chemical-shift analyses localized the aptamer-binding sites on the Fc subdomain, which partially overlaps the protein A binding site but not the Fcgamma receptor binding site. The tertiary structures of the predicted recognition sites on the Fc domain differ significantly between human IgG and other species of IgGs; this, in part, accounts for the high specificity of the selected aptamer. Apt8-2 can therefore be used as a protein A alternative for affinity purification of human IgG and therapeutic antibodies. Using Apt8-2 would have several potential advantages, raising the possibility of developing new applications based on aptamer design.

Evaluation of selective competitive binding of basic drugs to alpha1-acid glycoprotein variants.

We examined the binding of various basic drugs to the F(1)S and A genetic variants of alpha(1)-acid glycoprotein (AGP), which were isolated from native human commercial AGP (total AGP) by chromatography on an immobilized copper(II) affinity adsorbent. The values of the dissociation constant (K(d)) of some basic drugs with the F(1)S variant in equilibrium dialysis differed characteristically from those with the A variant. The selective binding to these variants was evaluated by measuring the displacement ratio of dicumarol bound to the F(1)S variant or that of acridine orange bound to the A variant, using circular dichroism spectroscopy. There was reasonably good agreement between the K(d) values and displacement ratios. There was a characteristic difference between the values of inhibition constant (K(i)) of basic drugs towards dipyridamole binding to F(1)S and towards disopyramide binding to A in total AGP. We found that the K(i) values for dipyridamole binding were well correlated with the K(d) values for the F(1)S variant, whereas those for disopyramide binding were well correlated with the K(d) values for the A variant. In conclusion, the higher the affinity of basic drugs for AGP, the more they inhibit the binding of other basic drugs, and further, the inhibitory potency depends on the selectivity of binding to the AGP variants.

Screening of novel inhibitors of HIV-1 reverse transcriptase with a reporter ribozyme assay.

"Highly active anti-retroviral therapy (HAART)" is currently the standard treatment for human immunodeficiency virus (HIV). This treatment consists of a cocktail of two reverse transcriptase (RT) inhibitors and a protease inhibitor. Despite the success of this regimen, there is a continuing need for innovative drug to overcome problems with tolerability and the emergence of viral resistance. The present protocol describes a novel strategy to rapidly screening a new class of small molecule HIV-1 RT inhibitors, which bind to the primer/template binding site of RT, as yet an unexplored site for small molecule interference on this target. The assay is based on aptamer-displacement which is visualized by applying a rationally designed HIV-1 RT responsive ribozyme. The handiness of the assay procedure permits automation, compatible with high-throughput screening (HTS). Subsequently, the identified hit compounds have been evaluated by an in vitro enzymatic assay to test the inhibitory potential. The strategy provides a powerful and efficient screening format for site-directed inhibitors with biological activity.

A Chymase Inhibitory RNA Aptamer Improves Cardiac Function and Survival after Myocardial Infarction.

We have reported that mast cell chymase, an angiotensin II-generating enzyme, is important in cardiovascular tissues. Recently, we developed a new chymase-specific inhibitory RNA aptamer, HA28, and we evaluated the effects of HA28 on cardiac function and the mortality rate after myocardial infarction. Echocardiographic parameters, such as the left ventricular ejection fraction, fractional shortening, and the ratio of early to late ventricular filling velocities, were significantly improved by treatment with HA28 after myocardial infarction. The mortality rate was significantly reduced in the HA28-treated group. Cardiac chymase activity and chymase gene expression were significantly higher in the vehicle-treated myocardial infarction group, and these were markedly suppressed in the HA28-treated myocardial infarction group. The present study provides the first evidence that a single-stranded RNA aptamer that is a chymase-specific inhibitor is very effective in the treatment of acute heart failure caused by myocardial infarction. Chymase may be a new therapeutic target in post-myocardial infarction pathophysiology.

Aptamer displacement identifies alternative small-molecule target sites that escape viral resistance.

Aptamers targeting reverse transcriptase (RT) from HIV-1 inhibit viral replication in vitro, presumably by competing with binding of the primer/template complex. This site is not targeted by the currently available small-molecule anti-HIV-1 RT inhibitors. We have identified SY-3E4, a small-molecule inhibitor of HIV-1 RT, by applying a screening assay that utilizes a reporter-ribozyme regulated by the anti-HIV-1 RT aptamer. SY-3E4 displaces the aptamer from the protein, selectively inhibits DNA-dependent, but not RNA-dependent, polymerase activity, and inhibits the replication of both the wild-type virus and a multidrug-resistant strain. Analysis of available structural data of HIV-1 and HIV-2 RTs rationalizes many of the observed characteristics of the inhibitory profiles of SY-3E4 and the aptamer and suggests a previously not considered region in these RTs as a target for antiviral therapy. Our study reveals unexplored ways for rapidly identifying alternative small-molecule target sites in proteins and illustrates strategies for overcoming resistance-conferring mutations with small molecules.