Inhaled modified angiotensin converting enzyme 2 (ACE2) as a decoy to mitigate SARS-CoV-2 infection.

COVID-19 is a new zoonotic disease caused by the SARS-CoV-2 virus. Since its emergence in Wuhan City, China, the virus has rapidly spread across the globe causing calamitous health, economic and societal consequences. It causes disproportionately severe disease in the elderly and those with co-morbidities, such as hypertension and diabetes. There is currently no proven treatment for COVID-19 and a safe and effective vaccine is at least a year away. The virus gains access to the respiratory epithelium through cell surface angiotensin converting enzyme 2 (ACE2). The receptor binding domain (RBD) of the virus is unlikely to mutate without loss of pathogenicity and thus represents an attractive target for antiviral treatment. Inhaled modified recombinant human ACE2, may bind SARS-CoV-2 and mitigate lung damage. This decoy strategy is unlikely to provoke an adverse immune response and may reduce morbidity and mortality in high-risk groups.

Gel scaffolds of BMP-2-binding peptide amphiphile nanofibers for spinal arthrodesis.

Peptide amphiphile (PA) nanofibers formed by self-assembly can be customized for specific applications in regenerative medicine through the use of molecules that display bioactive signals on their surfaces. Here, the use of PA nanofibers with binding affinity for the bone promoting growth factor BMP-2 to create a gel scaffold for osteogenesis is reported. With the objective of reducing the amount of BMP-2 used clinically for successful arthrodesis in the spine, amounts of growth factor incorporated in the scaffolds that are 10 to 100 times lower than that those used clinically in collagen scaffolds are used. The efficacy of the bioactive PA system to promote BMP-2-induced osteogenesis in vivo is investigated in a rat posterolateral lumbar intertransverse spinal fusion model. PA nanofiber gels displaying BMP-2-binding segments exhibit superior spinal fusion rates relative to controls, effectively decreasing the required therapeutic dose of BMP-2 by 10-fold. Interestingly, a 42% fusion rate is observed for gels containing the bioactive nanofibers without the use of exogenous BMP-2, suggesting the ability of the nanofiber to recruit endogenous growth factor. Results obtained here demonstrate that bioactive biomaterials with capacity to bind specific growth factors by design are great targets for regenerative medicine.

Discovery of a novel retrovirus sequence in an Australian native rodent (Melomys burtoni): a putative link between gibbon ape leukemia virus and koala retrovirus.

Gibbon ape leukaemia virus (GALV) and koala retrovirus (KoRV) share a remarkably close sequence identity despite the fact that they occur in distantly related mammals on different continents. It has previously been suggested that infection of their respective hosts may have occurred as a result of a species jump from another, as yet unidentified vertebrate host. To investigate possible sources of these retroviruses in the Australian context, DNA samples were obtained from 42 vertebrate species and screened using PCR in order to detect proviral sequences closely related to KoRV and GALV. Four proviral partial sequences totalling 2880 bases which share a strong similarity with KoRV and GALV were detected in DNA from a native Australian rodent, the grassland melomys, Melomys burtoni. We have designated this novel gammaretrovirus Melomys burtoni retrovirus (MbRV). The concatenated nucleotide sequence of MbRV shares 93% identity with the corresponding sequence from GALV-SEATO and 83% identity with KoRV. The geographic ranges of the grassland melomys and of the koala partially overlap. Thus a species jump by MbRV from melomys to koalas is conceivable. However the genus Melomys does not occur in mainland South East Asia and so it appears most likely that another as yet unidentified host was the source of GALV.

Randomized, controlled comparison of advanced hemostatic pads in hepatic surgical models.

Blood loss during hepatic surgery leads to poor patient outcomes. This study investigates the hemostatic efficacy of a novel sealing hemostatic pad (polyethylene glycol-coated collagen, PCC) and a fibrin sealant pad (fibrin-thrombin coated collagen, FTC) in a leporine hepatic segmentectomy and a porcine hepatic abrasion model. A segmentectomy was used to compare hemostatic success and hematoma incidence in 20 rabbits (10/group). Hepatic abrasions were used to compare hemostatic success up to 10 min after application in six pigs (42 lesions/group). In the segmentectomy model, PCC achieved 100% hemostatic success within 2 min (95% CI: 72.3% to 100%) and FTC achieved 80% hemostatic success within 3 min (49.0% to 94.3%). PCC had lower hematoma incidence at 15 min (0.0 versus 11.1%) and 24 h (20.0 versus 66.7%). In the abrasion model, PCC provided superior hemostatic success at 3 (odds ratio: 24.8, 95% CI: 8.86 to 69.2, P < 0.001), 5 (66.3, 28.5 to 153.9, P < 0.001), 7 (177.5, 64.4 to 489.1, P < 0.001), and 10 min (777.6, 148.2 to 4078, P < 0.001) leading to statistically significant less blood loss. The novel sealing hemostat provides faster and more sustained hemostasis than a fibrin sealant pad in a leporine hepatic segmentectomy and a porcine hepatic abrasion model of hepatic surgery.

A Reproductive Management Program for an Urban Population of Eastern Grey Kangaroos (Macropus giganteus).

Traditionally, culling has been the expedient, most common, and in many cases, the only tool used to control free-ranging kangaroo populations. We applied a reproductive control program to a population of eastern grey kangaroos confined to a golf course in South East Queensland. The program aimed to reduce fecundity sufficiently for the population to decrease over time so that overgrazing of the fairways and the frequency of human-animal conflict situations were minimised. In 2003, 92% of the female kangaroos above 5 kg bodyweight were implanted with the GnRH agonist deslorelin after darting with a dissociative anaesthetic. In 2007, 86% of the females above 5 kg were implanted with deslorelin and also 87% of the males above 5 kg were sterilised by either orchidectomy or vasectomy. In 2005, 2008 and 2009, the population was censused to assess the effect of each treatment. The 2003 deslorelin program resulted in effective zero population growth for approximately 2.5 years. The combined deslorelin-surgery program in 2007 reduced the birth rate from 0.3 to 0.06%/year for 16 months, resulting in a 27% population reduction by November 2009. The results were consistent with implants conferring contraception to 100% of implanted females for at least 12 months. The iatrogenic mortality rates for each program were 10.5% and 4.9%, respectively, with 50% of all mortalities due to darting-related injuries, exertional myopathy/hyperthermia or recovery misadventure. The short term sexual and agonistic behaviour of the males was assessed for the 2007 program: no significant changes were seen in adult males given the vasectomy procedure, while sexual behaviours' were decreased in adult males given the orchidectomy procedure. It is concluded that female reproduction was effectively controlled by implantation with deslorrelin and male reproductive behaviour was reduced by orchidectomy, which together achieved population control.

Case study: contamination of heparin with oversulfated chondroitin sulfate.

In late 2007 and early 2008, a cluster of adverse events in patients receiving Heparin Sodium Injection occurred in the United States and in some countries in Europe. The adverse events were reported as being "allergic type" reactions, chiefly characterized by acute hypotension, nausea, and shortness of breath. The root cause of the cluster of adverse events was determined to be a contamination of the heparin by oversulfated chondroitin sulfate. The isolation and structure determination of this contaminant was accomplished by an FDA-led consortium of academic and government laboratories and independently by Baxter Healthcare, whose vial products were first identified in the USA as being associated with the adverse events. Oversulfated chondroitin sulfate was shown to produce acute hypotension in animal models, demonstrating that it was most likely the causative agent responsible for certain of the reported adverse events in patients receiving the contaminated heparin products.

Acetaminophen-induced forestomach lesion in normal rats following intravenous exposure.

Four groups of ten male and ten female rats each were treated intravenously with saline, 400 mg/kg/day of a commercially available injectable acetaminophen formulation, or 400 mg/kg/day of a new injectable acetaminophen formulation with (aged) or without (fresh) impurities daily for fourteen days. Gross observations of the mucosal surface of the stomachs from treated rats included multifocal to diffuse pale, elevated foci confined to the nonglandular region of the stomach. Treatment-related histologic observations consisted of epithelial hyperplasia and hyperkeratosis of the nonglandular mucosa of the stomach. The epithelial hyperplasia was characterized by a thickened epithelium, frequently accompanied by the development of undulations at the basement membrane zone, resulting in the formation of rete ridgelike structures protruding into the underlying tissue. The submucosa was usually expanded by edema and occasionally contained an infiltrate of neutrophils, eosinophils, and macrophages. The hyperplasia was usually accompanied by hyperkeratosis resulting in thickening of the stratum corneum. The incidence and severity of the gastric changes were similar across all treatment regimens. Although considered clinically irrelevant since humans do not have a forestomach equivalent, these results are significant in that this appears to be the first report of forestomach hyperplasia and hyperkeratosis following intravenous exposure to acetaminophen.

Seasonal reproduction in wild and captive male koala (Phascolarctos cinereus) populations in south-east Queensland.

The effects of breeding season (late spring to early autumn) on south-east Queensland male koala fertility were examined to improve the efficacy of the AI procedure and to determine the practicality of using free-range animals as semen donors for a genome resource bank. Seasonal changes in male koala reproductive function were assessed in a wild free-range population (n = 14; obtained every 6 weeks from January to November 2005), a necropsied healthy wild population (n = 84; obtained monthly from September 2004 to August 2005) and a captive population (n = 7; obtained monthly from October 2005 to October 2006). Reproductive parameters investigated included bodyweight, coat score, sternal gland area and activity, testosterone secretion, reproductive anatomy volume and semen quality (before and after cryopreservation). Collectively, these findings show that reproduction in male koalas from south-east Queensland changes seasonally and that winter appears to be the optimal season in which to collect semen samples by electroejaculation. While it was possible to repeatedly collect semen from free-range koalas for future genetic management via potential storage in a genome resource bank, the survival of these spermatozoa after cryopreservation was poor and will require further improvement.

Nanosuspension formulation of itraconazole eliminates the negative inotropic effect of SPORANOX in dogs.

Previously, it was observed that a nanosuspension formulation of itraconazole was more efficacious and yet less acutely toxic in rats as compared with the conventional solution formulation, SPORANOX (itraconazole) Injection. The present study compares the two formulations with respect to specifically myocardial contractility in conscious dogs. Motivation for doing so is highlighted by the black-box warning in the package insert for SPORANOX (itraconazole) Injection, which warns of negative inotropic effects. Conscious dogs, instrumented with a high-fidelity pressure transducer in the left ventricle, were placed in a sling for dosing and cardiac monitoring. Test and control articles were administered intravenously via a peripheral vein, and left ventricular parameters were measured continuously through 60 min from the start of dosing. As expected, SPORANOX (itraconazole) Injection caused a significant reduction in myocardial contractility as determined by the contractility index. In contrast, the itraconazole nanosuspension administered at twice the dose and at twice the rate of infusion did not result in significant changes in myocardial contractility. A novel formulation technology applied to itraconazole completely prevented the negative inotropic effect observed in conscious dogs as compared with SPORANOX (itraconazole) Injection.

Structure elucidation and biological activity of the oversulfated chondroitin sulfate contaminant in Baxter heparin.

From late December 2007 to February 2008, the number of adverse responses to heparin infusions rose noticeably above baseline levels in North America, ultimately resulting in a widespread recall of all heparin vial products made by Baxter Healthcare. Using various analytical techniques and the de novo synthesis of a fully sulfated chondroitin sulfate (FSCS) derivative, the authors have confirmed the identity of the contaminant as an oversulfated chondroitin sulfate (OSCS) and have also defined the heterogeneity and concentration of this contaminant in various lots of heparin. Using both contaminated heparin products and the synthetically produced derivative, the authors have shown that the OSCS produces a dose-dependent hypotension in both pigs and rats and that the response in rats can be abrogated with bradyzide, a rodent-selective B(2) bradykinin receptor antagonist. The no observed effect level (NOEL) for this contaminant appears to be approximately 1 mg/kg, corresponding to a contamination level in finished lots of heparin of approximately 3%. Using human plasma, the OSCS derivative was shown to activate kallikrein. These data provide insight into the etiology of the adverse events, particularly refractory hypotension, observed in patients who were exposed to heparin contaminated with OSCS.

Identification of a simple and sensitive microplate method for the detection of oversulfated chondroitin sulfate in heparin products.

Heparin is a commonly implemented anticoagulant used to treat critically ill patients. Recently, a number of commercial lots of heparin products were found to be contaminated with an oversulfated chondroitin sulfate (OSCS) derivative that could elicit a hypotensive response in pigs following a single high-dose infusion. Using both contaminated heparin products and the synthetically produced derivative, we showed that the OSCS produces dose-dependent hypotension in pigs. The no observed effect level (NOEL) for this contaminant appears to be approximately 1mg/kg, corresponding to a contamination level of approximately 3%. We also demonstrated that OSCS can be identified in heparin products using a simple, inexpensive, commercially available heparin enzyme immunoassay (EIA) kit that has a limit of detection of approximately 0.1%, well below the NOEL. This kit may provide a useful method to test heparin products for contamination with oversulfated GAG derivatives.

The microbiological quality of beef tripe using different processing techniques.

The microbiological quality of routinely processed tripe and rumen pillars were compared with those derived after emptying the rumen (paunch) without using water (dry dumping) and after deliberately bursting the paunches before processing. Prior to packing the mean log(10) aerobic plate counts (APC) for the routinely processed tripe and rumen pillars were 3.55±1.08 and 3.28±0.87/g respectively. The corresponding mean log(10) total coliform counts (TCC) were 1.27±1.28 and 2.08±0.87. The mean log(10) APC counts on tripe and rumen pillars after dry-dumping were 3.06± 0.60 and 3.90± 0.75/g, respectively. The corresponding mean log(10) TCC were 1.03± 0.60/g and 2.75± 1.14/g respectively. After deliberately bursting the paunches, before processing, the mean log(10) APC counts on tripe and rumen pillars were 3.55±0.83/g and 3.50± 0.59/g and the mean log(10) TCC were 1.54± 0.95/g and 2.66± 0.82/g respectively. In all cases the prevalence of Salmonella and Campylobacter spp. was less than 3%. The results indicate that both tripe and rumen pillars can be produced after dry dumping without compromising the quality of tripe and rumen pillars. Similarly, incidentally burst paunches that become contaminated with ingesta on the serosal surface can be processed without compromising product quality.