Evaluation of a novel, rapid-acting, sterilizing solution at room temperature.

Test data are presented for a novel chemical germicide formulation capable of sterilizing reusable medical devices in 30 minutes at 20 degrees C in an open tray. The tests conducted with this rapid-acting sterilizing solution (RSS) included sporicidal, mycobactericidal, and virucidal studies performed in accordance with Association of Official Analytical Chemist International or Environmental Protection Agency published guidelines, by using RSS stressed for as long as 7 days. Sporicidal assays were performed at 20 degrees C with a 30-minute exposure time by using both Clostridium sporogenes and Bacillus subtilis spores dried on porcelain penicylinders or suture loops (n = 60 carriers per treatment). For comparison, identical carriers were exposed to a commercial glutaraldehyde-based sterilizing solution stressed to a maximum-use time of 14 days and exposed per manufacturer's requirements (10 hours at 25 degrees C). The RSS sterilized 100% of the carriers of both spore types. The glutaraldehyde solution demonstrated 100% sterilization of C sporogenes -treated carriers but had difficulty sterilizing B subtilis spore-laden carriers (ie, no sterilization of suture loops and only 57% sterilization of porcelain penicylinders). Similarly, Mycobacteria bovis and selected fungal and viral agents were exposed to stressed solution for 5 minutes or less at 20 degrees C. In each case, the resulting log decrease in viable microorganisms significantly supported a claim for rapid high-level disinfection. Based on these data, RSS demonstrates high-level disinfection in 5 minutes and sterilization in 30 minutes at 20 degrees C.

Phonophoretic delivery of 10% hydrocortisone through the epidermis of humans as determined by serum cortisol concentrations.

BACKGROUND AND PURPOSE: The purpose of this investigation was to determine whether application of hydrocortisone phonophoresis enhances transcutaneous delivery of topically applied hydrocortisone in humans, as determined by blood cortisol levels. SUBJECTS: The subjects were 16 men and women, between the ages of 18 and 33 years (X = 25, SD = 2.74), without symptoms of any ongoing inflammatory condition. METHODS: A gel coupling medium containing 10% hydrocortisone acetate was used. Ultrasound was delivered over a 50-cm2 area for 5 minutes at an intensity of 1.0 W/cm2 and a frequency of 1.0 MHz. Each subject received a control treatment (ultrasound alone) and an experimental treatment (hydrocortisone phonophoresis) on the volar aspect of the forearm 1 week apart. Blood was drawn, under both control and experimental conditions, from a cubital vein just proximal to the treatment site prior to each treatment and 0,5, and 15 minutes posttreatment. Serum cortisol concentrations were measured using a fluorescence polarization immunoassay. RESULTS: No rise in serum cortisol concentrations following hydrocortisone phonophoresis was detected. CONCLUSION AND DISCUSSION: These findings suggest that there was no penetration of hydrocortisone through the epidermis and into the underlying vasculature. Clinical implications regarding hydrocortisone levels within the subcutaneous tissues are discussed, and further research is suggested.

Comparison of standard culture methods, a shell vial assay, and a DNA probe for the detection of herpes simplex virus.

A nonradioactive, biotinylated herpes simplex virus (HSV) DNA probe, a shell vial (rabbit kidney cell) culture assay enhanced by a direct fluorescent (HSV monoclonal)-antibody stain at 16 to 20 h postinoculation, and conventional tube cultures with confirmation via HSV-specific (polyclonal antibody) immunoperoxidase assay were compared for 199 specimens. The predictive values of the positive results were 54.5% for the probe, 95.9% for the shell vial assay, and 100% for the conventional culture methods, while the predictive values of the negative tests were 68.1, 84.0, and 98.4%, respectively. We conclude that the DNA probe (sensitivity, 24.5%; specificity, 88.3%) and the shell vial assay (sensitivity, 66.2%; specificity, 98.4%) cannot be substituted for conventional tube culture techniques (sensitivity, 97.1%; specificity, 100%) in the routine identification of HSV in our laboratory.

An investigation of hepatitis A virus infected blood products.

Hepatitis A virus (HAV) infection via the parenteral route is not common. To investigate this further, we obtained the fresh frozen plasma (FFP) component from a unit of whole blood provided by an HAV-infected donor and attempted to quantify and characterize the virus in this material. Despite repeated efforts at culture and cesium banding, HAV was not detected by these methods. However, a hepatitis-A-specific antibody capture assay did demonstrate an occasional HAV-like particle upon electron microscopic analysis of plasma-derived material. We conclude that the quantity of virus present in HAV-contaminated blood or products may be variable and therefore of insufficient numbers as to induce clinically apparent disease in all recipients.

A structural model for the genome of echovirus 22.

We have proposed previously that the structural model for the echovirus 22 genome is a single-stranded RNA molecule that has folded back upon itself to form a stable "hairpin" at the 5'-terminus. The vRNA of echovirus 22 has been characterized further by digestion with selective ribonucleases, electrophoresis in composite gels, hydrodynamic studies in density gradients of Cs2SO4 and sucrose, thermal denaturation and 3'-terminal ribonucleotide analysis. Based on these observations, the genome of echovirus 22 is a single-stranded RNA molecule having a region of secondary structure located at the 5'-terminus that may be characterized as a snapback hairpin with hydrogen-bonded base-pairing. In addition, a VPg-like protein is attached (presumably to the 5'-end of the RNA) and the 3'-terminus contains a polyadenylic acid tract [poly (A)].

Evidence for secondary structure within the virion RNA of echovirus 22.

Phenol-extracted echovirus 22 virion RNA is infectious, but unlike poliovirus virion RNA, it resists digestion with pancreatic RNase and nuclease P-1, a 3' exonuclease selective for single-stranded RNA. These data indicate the presence of an enzyme-resistant portion somewhere in the RNA molecule and suggest that it is a double-stranded or base-paired region distant from the unblocked 3' terminus. Equilibrium density gradient centrifugation of native echovirus 22 virion RNA results in a single peak with a density of 1.63 g/cm3. When sheared before centrifugation, the molecule is resolved into two RNA species: one with an approximate density of 1.70 to 1.71 g/cm3, as is observed also for single-stranded poliovirus virion RNA, and the other with a density of 1.58 to 1.59 g/cm3. Data obtained from rate zonal centrifugation may be used to calculate an approximate sedimentation coefficient corrected to water at 20 degrees C of 34 and a molecular weight of 2.4 X 10(6) for the virion RNA. We propose a model for echovirus 22 RNA composed of a linear RNA molecule with a 5' hairpin.

Evaluation of the effectiveness of 2H-1,3-oxazine-2,6(3H)-dione (oxauracil) in the treatment of herpes simplex virus (HSV)-induced acute encephalitis in mice.

Treatment of suckling mice with the pyrimidine analogue 2H-1,3-oxazine-2,6(3H)-dione (oxauracil) proved successful in reducing mortality associated with HSV-2-induced encephalitis. Oxauracil did not decrease mortality associated with HSV-1 infection; however, there was an increased survival time and a decrease in the amount of infectious virus recovered from the brains of HSV-1-infected animals.

A simple method for typing clinical isolates of herpesvirus simplex: replication in the presence of 2H-1,3-oxazine-2,6 (3H)-dione (Oxauracil).

A rapid simple method for the typing of wild HSV isolates based on selective inhibition of HSV-2 replication by the pyrimidine analogue oxauracil (2H-1,3-oxazine-2,6(3H)-dione) has been developed. Chi-square analysis of the results of typing of 30 wild strains by serum neutralization tests, immunofluorescence, and oxauracil-inhibition indicates no significant differences in assignment of types to the isolates. The oxauracil-inhibition test obviates confusion of typing resulting from use of immune sera containing cross-reactive antibodies. We conclude oxauracil typing is a simple, rapid, and precise test which can be performed in any laboratory capable of isolating HSV.

Comparison of commercially available radial immunodiffusion kits for the determination of serum alpha 1-antitrypsin concentrations.

Six commercially available radial immunodiffusion kits for the determination of serum alpha1-antitrypsin concentrations were compared. Test samples were prepared by diluting purified human alpha1-antitrypsin to 2 different concentrations approximating heterozygous and homozygous deficiency concentrations. Significant variation in results was noted using the higher concentration of alpha1-antitrypsin. A greater degree of accuracy was demonstrated when testing the sample with the lower concentration. This further emphasizes the need for specific phenotyping in detecting patients with protease inhibitor types other than ZZ.