Protective effect of human recombinant copper-zinc superoxide dismutase (hr-cuznsod) on intermediate burn survival in rats

Objectives. Superoxide dismutase, acting as a scavenger of oxygen free radicals, has shown mixed results in increasing survival from burn wounds. We previously demonstrated that human recombinant copper-zinc superoxide dismutase could increase the survival of failing ischaemic flaps in a rat model. Because of the similar pathophysiology of tissue ischaemia in flaps and intermediate zone burns, we conducted a later study employing two groups of rats with standardized intermediate burns, to ascertain whether or not human recombinant copper-zinc superoxide dismutase could increase intermediate burn zone survival in rats. The results showed that post-burn human recombinant copper-zinc superoxide dismutase failed to improve intermediate burn zone survival. We decided to undertake a new study to ascertain whether there was a protective effect of human recombinant copper-zinc superoxide dismutase in intermediate burns. Methods. This controlled study employed two groups of rats, one of which received prophylactic treatment with human recombinant copper-zinc superoxide dismutase before the induction of standardized intermediate burns. Results. The results showed that pre-burn human recombinant copper-zinc superoxide dismutase also failed to improve intermediate burn zone survival. Conclusions. Further studies are needed to fully understand the effect of oxygen free radicals in burn wound pathophysiology and to determine whether human recombinant copper-zinc superoxide dismutase has a place in the clinical management of burns.

Evolution of +1 programmed frameshifting signals and frameshift-regulating tRNAs in the order Saccharomycetales

Programmed translational frameshifting is a ubiquitous but rare mechanism of gene expression in which mRNA sequences cause the translational machinery to shift reading frames with extreme efficiency, up to at least 50%. The mRNA sequences responsible are deceptively simple; the sequence CUU-AGG-C causes about 40% frameshifting when inserted into an mRNA in the yeast Saccharomyces cerevisiae. The high efficiency of this site depends on a set of S. cerevisiae tRNA isoacceptors that perturb the mechanism of translation to cause the programmed translational error. The simplicity of the system might suggest that it could evolve frequently and perhaps be lost as easily. We have investigated the history of programmed +1 frameshifting in fungi. We find that frameshifting has persisted in two structural genes in budding yeasts, ABP140 and EST3 for about 150 million years. Further, the tRNAs that stimulate the event are equally old. Species that diverged from the lineage earlier both do not employ frameshifting and have a different complement of tRNAs predicted to be inimical to frameshifting. The stability of the coevolution of protein coding genes and tRNAs suggests that frameshifting has been selected for during the divergence of these species.

Differential gene expression in rat colon by dietary heme and calcium

Dietary heme and calcium are alleged modulators of colon cancer risk. Little is known about the molecular and cellular changes in the colon epithelium that are induced by consumption of these unabsorbed nutrients. In this nutrigenomics study, we fed rats high- and low-calcium diets with or without heme. In agreement with previous studies, we found that dietary heme increased the cytotoxicity of fecal water in the colon and elevated epithelial proliferation, a risk factor in colon carcinogenesis. Calcium reduced cytotoxicity and inhibits heme-induced effects. Among 365 colon-expressed genes, we could identify 10 diet-modulated genes that show >2-fold altered expression, of which several are related to colon cell turnover and disease. Mucosal pentraxin (Mptx) was the strongest differentially expressed gene, approximately 10-fold down-regulated by dietary heme and 3-fold up-regulated by calcium. cDNA microarray and quantitative PCR analysis show that calcium significantly inhibits the effects of heme, which correlates with the physiological effects. Our results indicate that Mptx expression is related to colonic cell turnover, and that Mptx might be a marker for diet-modulated mucosal integrity. We also show that Mptx expression is restricted to the intestine, and occurs predominantly in the colon.

Intranasal immunization of guinea pigs with an immunodominant foot-and-mouth disease virus peptide conjugate induces mucosal and humoral antibodies and protection against challenge

Guinea pigs immunized intranasally with a keyhole limpet hemocyanin-linked peptide, corresponding to the prominent G-H loop of the VP1 protein of foot-and-mouth disease virus, raised substantial levels of antipeptide and virus-neutralizing antibodies in sera and of peptide-specific secretory immunoglobulin A in nasal secretions. In groups of animals immunized intranasally without adjuvant, 86 percent were fully protected upon challenge with homotypic virus. Surprisingly, animals given the peptide conjugates plus the mucosal adjuvant cholera toxin were afforded only partial protection in that primary lesions were observed in most animals, although spread to other feet was prevented. These results indicate that intranasal inoculation with the peptide offers a potential route of vaccination against foot-and-mouth disease and may be useful for eliciting protection in the upper respiratory tracts of susceptible animals.

Broad-spectrum virus reduction in red cell concentrates using INACTINE PEN110 chemistry

BACKGROUND AND OBJECTIVES

The risk of transmission of blood-borne pathogens by transfusion is a persistent problem in medicine. To address this safety issue, INACTINE PEN110 chemistry is being utilized to develop a process for preparing pathogen-reduced red blood cell concentrates (RBCC). The purpose of this study was to characterize the virucidal effectiveness of the INACTINE PEN110 chemistry in full units of RBCC by using a panel of viruses with diverse properties in composition, size and shape.

MATERIALS AND METHODS

The panel included four enveloped (bovine viral diarrhoea virus, pseudorabies virus, vesicular stomatitis Indiana virus and sindbis virus), six non-enveloped (porcine parvovirus, human adenovirus 2, reovirus 3, vesicular exanthema of swine virus, bluetongue virus, and foot and mouth disease virus) and cell-associated (human immunodeficiency) viruses. All viruses were individually spiked into CPD/AS-1, CP2D/AS-3 and CPD/AS-5 RBCC units and treated with 0.1% PEN110 (vol/vol) at 22 +/- 2 degrees C for up to 22 +/- 2 h. The PEN110 treatment reaction was stopped by chemical quenching, and residual virus was assayed. The cytotoxicity effect of PEN110-treated RBCC on indicator cells and the potential interference with the ability of the virus to infect indicator cells was determined and taken into consideration for calculating the virus-reduction factors, to avoid underestimation or overestimation of the virus reduction.

RESULTS

The kinetics of inactivation for viruses spiked into CPD/AS-1, CP2D/AS-3 and CPD/AS-5 RBCC were equivalent. All viruses analysed in this study were reduced to the limit of detection of the assay. The reduction factors for the virus panel ranged from 4.2 to 7.5 log10/ml.

CONCLUSIONS

The results from the study demonstrate for the first time that a pathogen-reduction technology for RBCC can achieve a broad-spectrum virucidal effect against both enveloped and non-enveloped viruses. The broad spectrum of virucidal activity of INACTINE PEN110, and equivalent kinetics of virus inactivation in RBCC prepared using different commercially available RBC storage solutions, demonstrate the robustness of this pathogen-reduction process.

Carboxypeptidase E and thrombospondin-1 are differently expressed in subcutaneous and visceral fat of obese subjects

The aim of this study was to identify candidate genes for visceral obesity by screening for genes strongly differentially expressed between human subcutaneous and visceral adipose depots. A cDNA microarray with human adipose-derived cDNAs was used as an initial screening to identify genes that are potentially differentially expressed between human subcutaneous and visceral abdominal fat tissues. For the two best candidates, carboxypeptidase E (CPE) and thrombospondin-1 (THBS1) (EST N72406), real-time RT-PCR was performed to confirm their depot specific expression in extremely obese individuals. Both genes appeared to be strongly differentially expressed, having a higher expression in the visceral depot than in the subcutaneous one. For THBS1, the difference in expression between the depots was greater in women than in men. The involvement of CPE and THBS1 in obesity allows us to suggest that the physiological processes controlled by these genes contribute to depot and gender-related differences in the metabolic complications of obesity.

Perfusion brain scintigraphy studies in infants and children with malformations of the vein of Galen

Cerebral perfusion brain scintigraphy obtained in six unselected patients (age newborn to 14 years) from among 50 children with vein of Galen malformations was used in conjunction with magnetic resonance imaging to determine the basis of the neurological and cognitive abnormalities in patients with vein of Galen malformations (VGMs). Five had a hemiparesis - persistent, transient, or alternating. Four were developmentally delayed. Two had so far been cognitively normal and acquired a neurological deficit, following an embolization procedure. The school age patient had a nonverbal learning disability. Three had epilepsy and/or an abnormal electroencephalogram. Magnetic resonance imaging documented only the VGM, hydrocephalus and atrophy; one child with perinatal asphyxia had periventricular leukomalacia. Perfusion brain scintigraphy was normal in two (a normal infant, and a toddler with a hemiparesis and aphasia). Abnormal findings included: left parietal hypoperfusion, fronto-temporal atrophy, patchy flow; left fronto-temporal hypoperfusion, left hemiatrophy, bilateral medial temporal hypoperfusion, right cerebellar hypoperfusion; right temporal hypoperfusion, patchy flow; right hemiatrophy, occipital hypoperfusion. Perfusion brain scintigraphy findings correlated better with focal neurological and cognitive defects than did magnetic resonance imaging.

Synthetic peptide-based vaccine and diagnostic system for effective control of FMD

We have designed synthetic peptides corresponding to two different regions of the genome of foot-and-mouth disease virus (FMDV) that are effective as (a) a vaccine or (b) a diagnostic reagent which differentiates convalescent from vaccinated animals, respectively. The peptide vaccine is based on a sequence from the prominent G-H loop of VP1, one of the four capsid proteins. The sequence was optimized by the inclusion of a cyclic constraint and adjoining sequences, and broader immunogenicity was obtained by the incorporation of consensus residues at hypervariable positions. The peptide also included a promiscuous T-helper epitope for effective immunogenicity in outbred populations of large animals.The diagnostic reagent, a peptide based on non-structural (NS) protein 3B, is used in immuno-assays for the detection of antibodies. Antibodies to this NS protein are present in the sera of infected animals but not in the sera of vaccinated animals. The VP1 peptide can be used in complementary immuno-assays for confirmation of NS test results and to monitor for vaccination. This system for differential diagnosis is important to establish the disease-free status of a country.

Radiosensitization of tumor-targeted radioimmunotherapy with prolonged topotecan infusion in human breast cancer xenografts

Clinical radioimmunotherapy (RIT) of solid tumors holds great promise, but as yet has been unable to deliver tumoricidal radiation doses without unacceptable toxicity. Our experimental approach aims to potentiate the therapeutic action of radioimmunoconjugates at the tumor site and thus improve the efficacy of RIT by combination with other treatment modalities. The topoisomerase I inhibitors are a unique class of chemotherapeutic agents that interfere with DNA breakage-reunion by inhibiting the action of topoisomerase I. Preclinical studies suggest that prolonged infusion of topoisomerase I inhibitors enhances cell toxicity due to ionizing radiation. We evaluated the efficacy of combined treatment with continuous administration of topotecan and 90Y-MX-DPTA BrE3 monoclonal antibody (which recognizes an epitope of breast epithelial mucin expressed in most breast cancers) on human mammary carcinoma xenografts in nude mice. Topotecan or 90Y-BrE3 treatment alone delayed overall tumor growth rate transiently but did not affect survival. The combination of RIT with topotecan substantially reduced growth of relatively large established tumors and caused complete tumor regressions and prolonged tumor-free survival in a substantial proportion of treated animals. In vitro studies demonstrated an increase in apoptotic rate and a decrease in cell proliferation of tumor cell lines treated with this combination. We combined the radiosensitization property of topotecan and the specificity of systemic RIT to establish a novel therapy for solid tumors in an experimental tumor xenograft model.

Inactivation of viruses by aziridines

Ethyleneimine (EI) and N-acetylethyleneimine (AEI) have been shown to inactivate viruses belonging to most of the families described by the International Committee for the Taxonomy of Viruses. The mechanism by which they inactivate the viruses has not been established. In this paper, experiments with foot-and-mouth disease virus (FMDV) and poliovirus are described which indicate that the inactivating lesion is on the RNA.

High-dose carmustine, thiotepa and etoposide followed by autologous bone marrow rescue for the treatment of high risk central nervous system tumors

Forty-two patients (29 newly diagnosed) with high grade gliomas (n = 37), medulloblastoma (n = 2) or non-biopsied tumors (n = 3) with supratentorial (n = 24), brain stem (n = 11), posterior fossa (n = 5) or spinal (n = 2) location were eligible for this study with adequate organ function and no bone marrow tumor infiltration. Median patient age was 12.2 years (range, 0.7-46.8). A total of 600 mg/m2 BCNU, 900 mg/m2 thiotepa and 1500 or 750 mg/m2 etoposide (VP-16) was administered followed by autologous bone marrow reinfusion (ABMR). Twenty-one newly diagnosed patients received local irradiation (RT) post ABMR. Nine early deaths were observed (21%), as well as one secondary graft failure. Half of the patients aged 18 years or older experienced toxic deaths, whereas only 15% of patients younger than 18 years experienced toxic death (P = 0.05). Of 25 evaluable newly diagnosed patients, 20% achieved complete remission (CR) and 4% partial remission (PR), while 28% remained in continuing complete remission (CCR) and 44% remained with stable disease prior to RT. Of eight evaluable patients with recurrent disease, one achieved CR and two PR, while one remained in CCR and four with stable disease for 1 to 110.2 months. Overall survival was 36%, 24% and 17% at 1, 2 and 3 years following ABMR, with three newly diagnosed patients and one patient treated for recurrent disease being alive, without disease progression 64.4, 67.0, 86.3 and 110.2 months after ABMR, respectively. The combination of high-dose BCNU/ thiotepa/VP-16 has substantial toxicity but definite activity for high risk CNS tumors. Similar protocols with lower toxicity merit further evaluation in both newly diagnosed and recurrent CNS tumors.

Structural differences between foot-and-mouth disease and poliomyelitis viruses influence their inactivation by aziridines

Inactivation of foot-and-mouth disease virus (FMDV) and poliovirus by ethyleneimine (EI) and N-acetylethyleneimine (AEI) has been studied at 25 degrees and at 37 degrees C and in different ionic conditions. FMDV is inactivated rapidly in 100 mM Tris pH 7.6 by each reagent at both temperatures. Poliovirus is also inactivated rapidly in 100 mM Tris by EI at both temperatures and by AEI at 37 degrees C. However, it is inactivated much more slowly by AEI at 25 degrees C; but if the virus is first incubated overnight at 2 degrees C with AEI before transferring to 25 degrees C inactivation then proceeds rapidly. Moreover, the rate of inactivation at 25 degrees C is markedly increased if the virus is suspended in 1 mM Tris. We had interpreted these differences as being due to the greater penetrability of poliovirus (i) in 100 mM Tris at 37 degrees C compared with 25 degrees C and (ii) at lower ionic strength. This interpretation has been confirmed by electron microscopy of FMDV and poliovirus particles stained with phosphotungstic acid. At the elevated temperature, poliovirus had an average diameter of 34+/-0. 21 nm and the stain outlined the nucleic acid core and the individual subunits, whereas at 25 degrees C it averaged 28+/-0.13 nm and the stain did not penetrate the particle. This study also showed that the particle diameter alters with changes in buffer concentration, being 28+/-0.13 nm in 100 mM Tris, 31+/-0.16 nm in 10 mM Tris and 34+/-0.21 nm in 1 mM Tris. The changes in poliovirus are reversible as addition of 1/10 volume of 1 M Tris to the virus in 1 mM Tris resulted in the return of the diameter to 28+/-0.13 nm. FMDV, on the other hand, was less sensitive to osmotic differences as its particle diameter only varied by 7% over the 100-fold change in buffer concentration compared with the 22% change observed for poliovirus.

Accumulation of cyclin B1 requires E2F and cyclin-A-dependent rearrangement of the anaphase-promoting complex

In mammalian somatic-cell cycles, progression through the G1-phase restriction point and initiation of DNA replication are controlled by the ability of the retinoblastoma tumour-suppressor protein (pRb) family to regulate the E2F/DP transcription factors. Continuing transcription of E2F target genes beyond the G1/S transition is required for coordinating S-phase progression with cell division, a process driven by cyclin-B-dependent kinase and anaphase-promoting complex (APC)-mediated proteolysis. How E2F-dependent events at G1/S transition are orchestrated with cyclin B and APC activity remains unknown. Here, using an in vivo assay to measure protein stability in real time during the cell cycle, we show that repression of E2F activity or inhibition of cyclin-A-dependent kinase in S phase triggers the destruction of cyclin B1 through the re-assembly of APC, the ubiquitin ligase that is essential for mitotic cyclin proteolysis, with its activatory subunit Cdh1. Phosphorylation-deficient mutant Cdh1 or immunodepletion of cyclin A resulted in assembly of active Cdh1-APC even in S-phase cells. These results implicate an E2F-dependent, cyclin A/Cdk2-mediated phosphorylation of Cdh1 in the timely accumulation of cyclin B1 and the coordination of cell-cycle progression during the post-restriction point period.

Protection of swine from foot-and-mouth disease with one dose of an all-D retro peptide

Nine pigs were given a single inoculum of 100 microg of the all-D retro peptide corresponding to the immunodominant GH loop encompassing residues 141-159 of capsid protein VP1 of foot-and-mouth disease virus serotype A, sub-type 12. The peptide was conjugated to activated keyhole limpet haemocyanin and oil-adjuvanted before inoculation. The animals were challenged eleven weeks post-vaccination by exposing them to a pig which had been infected with the virus by inoculation. Two naive animals were included in the challenge study as controls. One of the vaccinated animals was completely unprotected and two developed very small lesions. None of the six remaining animals exhibited any clinical signs but two developed antibodies against nonstructural proteins indicating that replication of the virus had occurred. No evidence of replication could be detected in the remaining four animals, either by rise in neutralizing antibody titre or by production of antibodies against non-structural proteins specific for virus replication.

A universal virus inactivant for decontaminating blood and biopharmaceutical products

Removal of virus infectivity from blood and biopharmaceutical products prepared from blood is an issue of considerable importance. Irrespective of the methods that are chosen it is vital that the biological activity of the product is not impaired. For blood and unfractionated plasma or serum, the problem is even more challenging. Selective inactivation of the genome is the key step in the preparation of killed virus vaccines. Imines have been used for more than 30 years for the preparation of inactivated foot-and-mouth disease virus vaccines without any evidence of survival of virus infectivity. Moreover, the immunogenicity of the virus is unimpaired. Viruses belonging to all the recognised families can be inactivated by imines. The biological properties of several proteins, including the cell growth-promoting factors in calf serum, are not impaired using conditions which ensure the inactivation of > 10(15) infectious units of poliovirus and foot-and-mouth disease virus (FMDV). Moreover, both viruses can be inactivated by imines at 4 degrees C, thus providing a method for removing infectivity from protein preparations which are unstable at higher temperatures. The mechanism by which FMDV is inactivated has been studied. We found that the RNA extracted from the virus after inactivation at 4 degrees C was not degraded and contained no hidden breaks but nevertheless was non-infectious. However, it could be amplified by PCR using primers corresponding to the gene coding for a portion of the viral RNA polymerase, but not from that coding for VP1, one of the structural proteins, showing that alteration of a base or bases had occurred in that region.

[Physical therapy in prevention and treatment of osteoporosis]

Osteoporotic fractures, and in particular, hip fractures result in significant morbidity and mortality. Low bone mass is the main risk factor of enhanced bone fragility, resulting in an increased risk for hip fracture. Bone density of osteoporotic women with and without hip fractures show a considerable overlap. Therefore, other bone-independent factors also play an important role for the development of hip- and other osteoporotic fractures. One other important factor is falling. In 90% of hip fractures falling was involved [10-15], but only 5% or less of these falls resulted in a subsequent fracture. The view that adequate exercise is beneficial for skeletal health of children and for prevention and treatment of osteoporosis in adults is supported primarily by two lines of evidence: longitudinal and cross-sectional trials in children and young adult athletes showing a significant increase of muscle- and bone mass after strenuous (children) or chronic exercise (athletes) as compared to normally active (children) or sedentary control subjects. What are the potential benefits and limits of specific exercise programs with respect to bone mass, prevention of falls and fractures? In this review these questions are discussed and a specific exercise program in osteoporotic patients with fractures is delineated.