Importance of ultrasonication conditions in recovery of microbial contamination from material surfaces

The conditions of ultrasonication to recover micro-organisms from material surfaces are not standardized and often not validated. This leads to discrepancies in experimental results which can affect the sterilization dose setting, cycle development and process validation, and can have an impact on sterilization processing economics and product sterile quality. The sample loading pattern, species of micro-organism, materials and configurations of sample containers were examined under defined conditions. All of these were found to be important factors contributing to the efficiency of microbial recovery from material surfaces by ultrasonication. Validation of sonication conditions in routine laboratory operations is therefore important for an accurate estimate of the surface contamination to assure the medical device processing and the product sterile quality.     

Structural characteristics of interferons from mouse Ehrlich ascites tumor cells.

An improved procedure for the isolation of interferons produced by mouse Ehrlich ascites tumor cells infected with Newcastle disease virus provides interferons of three size classes (33,000, 26,000, and 20,000 daltons) with specific activities between 2 and 3 x 10(9) units/mg of protein and a yield of 11 to 20%. The tryptic peptide maps of the two larger species are very similar; that of the smallest species is different, at least in part. The amino acid compositions of the three species are very close. Their NH2-terminal amino acids are identical and so are the amino acids released by carboxypeptidase A treatment. These data are consistent with the possibility that the differences in size between the three species may be due, at least in part, to unequal glycosylation.     

Importance of correct therapeutic procedure selection in voice recovery

Psychological and physical patient state as well as the influence of other social factor is of great influence voice rehabilitation. A team of experts in the field of voice and its function are involved in voice therapy. Our research was focused on the successfulness of voice recovery depending on the patient vocal disorder approach. We made a comparison of two methods: RVT and Accent method. We attempted to evaluate clinically relevant voice disorders in relation to certain vocal methods, we propose that a lot can be learned about voice trough therapeutic procedures, which can also be used to enhance the practical application of vocal methods and raise the level of success in dealing with people that suffer from voice pathology.     

Importance of target innervation in recovery from axotomy-induced loss of androgen receptor in rat perineal motoneurons

In adult male rats, axotomy of the spinal nucleus of the bulbocavernosus (SNB) motoneurons transiently down-regulates androgen receptor (AR) immunoreactivity. The present study investigates the importance of target reinnervation in the recovery of AR expression in axotomized SNB motoneurons after short (up to 5 days) and long (1 to 6 weeks) periods of recovery. In the long-term recovery experiment, animals were divided into two groups. In one, the two stumps of the cut pudendal nerve, which carries the axons of the SNB motoneurons, were sutured together immediately after axotomy. In the second group, the proximal stump was ligated immediately after axotomy to prevent target reinnervation. Axotomy of the SNB motoneurons caused a significant down-regulation in AR immunoreactivity within 3 days. At 6 weeks, AR immunoreactivity was still depressed in ligated animals but had recovered to control levels in resutured animals. The recovery in the resutured group was coincident with the first signs of reinnervation of the target perineal muscles, although reinnervation seemed to lag behind AR immunoreactivity. SNB soma size was significantly reduced 2 weeks after axotomy and returned to control levels after 6 weeks of recovery only in the resutured animals. These findings suggest that the target perineal muscles play a role in the regulation of AR expression and androgen sensitivity in the SNB motoneurons, perhaps mediated by muscle-derived trophic factors. © 1995 John Wiley & Sons, Inc.     

Heterogeneity of purified mouse interferons.

A procedure for obtaining highly purified stable interferon from mouse L cells is described. Interferon with a specific activity of 2.5 times 10-8 reference units/mg of protein is composed of 10 to 11 polypeptides. They differ in their molecular size as determined by electrophoresis on polyacrylamide gels containing sodium dodecyl sulfate. The molecular weight range is estimated to be from the smallest at 20, 000 to the largest at 32, 000. At least six of the polypeptides are glycoproteins and each of the polypeptides can be obtained as an apparent homogeneous entity and each has interferon activity.     

Reexamination of the efficacy of vaccination against mousepox

Experiments were conducted to evaluate the efficacy of three strains of vaccinia virus, IHD-T, Lister and Wyeth, to immunize the BALB/cByJ mouse against infection with ectromelia virus. Mice vaccinated with any of the strains were protected for at least 12 weeks against clinically apparent disease when challenged with cage-mates infected with a virulent stain (NIH-79) of ectromelia virus. However, 4 to 8 weeks after vaccination mice were capable of transmitting virus to non-vaccinated cage-mates. The results are discussed within the context of the current practices for preventing and controlling ectromelia epizootics.     

Convenient assay for interferons.

A convenient assay for interferons based on reduction of cytopathic effect was developed. The number of manipulations and the lengths of the various incubation steps were reduced to a minimum. The assay is simple to perform and can be completed within 16 h. Moreover, it can be used with various types of cells and a variety of viruses.     

Genetic determinants of resistance to ectromelia (mousepox) virus-induced mortality.

Resistance to ectromelia (mousepox) virus-induced mortality was examined in crosses between susceptible DBA/2J, A/J, and BALB/cByJ mice and resistant C57BL/6J and AKR/J mice. Depending on the cross, resistance to mousepox virus was shown to be determined by one or more independently assorting autosomal loci with dominant alleles for resistance in AKR/J and C57BL/6J mice and recessive alleles in A/J, BALB/cByJ, and DBA/2J mice. A sexual dimorphism in resistance to disease was also observed.     

Immunocytochemical localization of interferons in human trophoblast populations.

It is known that Interferon (IFN) is present in normal body fluids and tissues during pregnancy. Using an immunohistochemical technique and a panel of monoclonal antibodies we have localized IFN-alpha, -beta and -gamma directly on formalin-fixed paraffin-embedded normal human placentae at different stages of pregnancy and in the hydatidiform mole. The results show that IFNs is mostly localized in villous syncytiotrophoblast and in extravillous interstitial-trophoblast. No reactivity was observed in villous cytotrophoblast or in cytotrophoblast cell columns. The most intense staining was observed for IFN-alpha and -beta, while IFN-gamma was rather weak. There is then a gradual diminution in IFN reactivity with increasing gestation age being almost imperceptible at term. These results suggest that IFN may deploy antiviral, immunomodulator and differentiation activities during normal human pregnancy.     

Modulation of monocyte complement synthesis by interferons.

Recombinant Escherichia coli-derived gamma-interferon has been shown to stimulate synthesis of the second component of complement (C2), factor B and C1 inhibitor, but to inhibit synthesis of the third component (C3). alpha- and beta-interferons stimulate synthesis of factor B and C3 inhibitor, inhibit C5 synthesis but do not alter synthesis of C2. alpha- and beta-interferons act synergistically with gamma-interferon to enhance both factor B and C1-inhibitor synthesis.     

Antiviral activity of mutant interferons. A new approach to the study of structural-functional organization of interferons

The developed approach to investing the structure-functional organization of interferon has been developed consisting in: 1) fusing genes of interferon and alpha-peptide of beta-galactosidase, the resultant protein having the interferon properties and being determined by the beta-galactosidase alpha-complementation test; 2) constructing mutant genes of interferon by the localized mutagenesis; 3) determining the mutant interferon activity; 4) deducing the amino acid sequence of mutant interferon by sequencing mutant genes; 5) analyzing structure-functional organization of interferon. In accordance with this approach, ten mutant interferons with up to 15 changes of amino acid substitutions are obtained and their antiviral activity is determined. The role of some amino acid residues in antiviral activity of interferon alpha 2 is revealed.     

Role of interferons in maternal recognition of pregnancy in ruminants.

It has recently become evident that a type I interferon (IFN) subtype signals the presence of a viable conceptus to the mother during early pregnancy in cattle, sheep, and related mammalian species. This IFN, which is a product of the epithelium (trophectoderm) of the expanding trophoblast, is expressed in extremely large quantities for a few days just prior to implantation. It appears to be involved in modulating the release of the luteolytic hormone, prostaglandin F2 alpha, from the uterine endometrium and, hence, preventing the destruction of the corpus luteum that normally occurs at the end of an estrous cycle if an egg has not been fertilized. These trophoblast IFN have antiviral, antiproliferative, and immunomodulatory properties quite similar to other type I IFN, such as IFN-alpha, -beta, and -omega. However, they constitute a structurally and serologically distinct subtype. In addition, they are poorly inducible by virus, and the promoter regions of their genes are organized differently than other type I IFN. The genes for these trophoblast IFN are confined to ruminant species in the Artiodactyla order and probably evolved from IFN-omega less than 55 million years ago. There is no evidence for comparable production of type I IFN by trophoblast and placental tissues of mammals outside this ruminant group. Recent experiments have indicated that IFN treatment may have value in improving reproductive performance of sheep when provided during the period of maternal recognition of pregnancy, when much embryonic loss is believed to occur.     

Mink parvoviruses and interferons: in vitro studies.

Although interferons can inhibit the replication of a number of viruses, little is known about their ability to inhibit parvovirus replication. Therefore, in vitro experiments were done to determine if Aleutian disease virus and mink enteritis virus, two autonomously replicating mink parvoviruses, induced interferon, were sensitive to the effects of interferon, or inhibited the production of interferon. The results indicated that these parvoviruses neither induced nor were sensitive to the effects of interferon. Furthermore, preexisting parvovirus infections did not inhibit poly(I).poly(C)-induced interferon production. This independence from the interferon system may, therefore, be a general property of the autonomously replicating parvoviruses.