The 2000 Canine Distemper Epidemic in Caspian Seals (Phoca caspica): Pathology and Analysis of Contributory Factors

More than 10,000 Caspian seals ( Phoca caspica) were reported dead in the Caspian Sea during spring and summer 2000. We performed necropsies and extensive laboratory analyses on 18 seals, as well as examination of the pattern of strandings and variation in weather in recent years, to identify the cause of mortality and potential contributory factors. The monthly stranding rate in 2000 was up to 2.8 times the historic mean. It was preceded by an unusually mild winter, as observed before in mass mortality events of pinnipeds. The primary diagnosis in 11 of 13 seals was canine distemper, characterized by broncho-interstitial pneumonia, lymphocytic necrosis and depletion in lymphoid organs, and the presence of typical intracytoplasmic inclusion bodies in multiple epithelia. Canine distemper virus infection was confirmed by phylogenetic analysis of reverse transcriptase-polymerase chain reaction products. Organochlorine and zinc concentrations in tissues of seals with canine distemper were comparable to those of Caspian seals in previous years. Concurrent bacterial infections that may have contributed to the mortality of the seals included Bordetella bronchiseptica (4/8 seals), Streptococcus phocae (3/8), Salmonella dublin (1/8), and S. choleraesuis (1/8). A newly identified bacterium, Corynebacterium caspium, was associated with balanoposthitis in one seal. Several infectious and parasitic organisms, including poxvirus, Atopobacter phocae, Eimeria- and Sarcocystis-like organisms, and Halarachne sp. were identified in Caspian seals for the first time.

Modelling the Impact of Atherosclerosis on Drug Release and Distribution from Coronary Stents

Although drug-eluting stents (DES) are now widely used for the treatment of coronary heart disease, there remains considerable scope for the development of enhanced designs which address some of the limitations of existing devices. The drug release profile is a key element governing the overall performance of DES. The use of in vitro, in vivo, ex vivo, in silico and mathematical models has enhanced understanding of the factors which govern drug uptake and distribution from DES. Such work has identified the physical phenomena determining the transport of drug from the stent and through tissue, and has highlighted the importance of stent coatings and drug physical properties to this process. However, there is limited information regarding the precise role that the atherosclerotic lesion has in determining the uptake and distribution of drug. In this review, we start by discussing the various models that have been used in this research area, highlighting the different types of information they can provide. We then go on to describe more recent methods that incorporate the impact of atherosclerotic lesions.

Specific gut microbiota features and metabolic markers in postmenopausal women with obesity

BACKGROUND

Gut microbial gene richness and specific bacterial species are associated with metabolic risk markers in humans, but the impact of host physiology and dietary habits on the link between the gut microbiota and metabolic markers remain unclear. The objective of this study was to identify gut metagenomic markers associated with estimates of insulin resistance, lipid metabolism and inflammation in obesity, and to explore whether the associations between metagenomic and metabolic markers persisted after adjustment for body fat, age and habitual dietary intake.

METHODS

Faecal DNA from 53 women with obesity was analysed through quantitative metagenomic sequencing and analysis, and a systematic search was performed for bacterial genes associated with estimates of insulin resistance, inflammation and lipid metabolism. Subsequently, the correlations between metagenomic species and metabolic markers were tested by linear regression models, with and without covariate adjustment.

RESULTS

One hundred and fourteen metagenomic species correlated with metabolic markers (P<0.001) including Akkermansia muciniphila, Bilophila wadsworthia, Bifidobacterium longum and Faecalibacterium prausnitzii, but also species not previously associated with metabolic markers including Bacteroides faecis and Dorea longicatena. The majority of the identified correlations between bacterial species and metabolic markers persisted after adjustment for differences in body fat, age and dietary macronutrient composition; however, the negative correlation with insulin resistance observed for B. longum and F. prausnitzii appeared to be modified by the intake of dietary fibre and fat, respectively.

CONCLUSIONS

This study shows that several gut bacterial species are linked to metabolic risk markers in obesity, also after adjustment for potential confounders, such as long-term diet composition. The study supports the use of gut metagenomic markers for metabolic disease prediction and warrants further investigation of causality.

Perivascular fat, AMP-activated protein kinase and vascular diseases

Perivascular adipose tissue (PVAT) is an active endocrine and paracrine organ that modulates vascular function, with implications for the pathophysiology of cardiovascular disease (CVD). Adipocytes and stromal cells contained within PVAT produce mediators (adipokines, cytokines, reactive oxygen species and gaseous compounds) with a range of paracrine effects modulating vascular smooth muscle cell contraction, proliferation and migration. However, the modulatory effect of PVAT on the vascular system in diseases, such as obesity, hypertension and atherosclerosis, remains poorly characterized. AMP-activated protein kinase (AMPK) regulates adipocyte metabolism, adipose biology and vascular function, and hence may be a potential therapeutic target for metabolic disorders such as type 2 diabetes mellitus (T2DM) and the vascular complications associated with obesity and T2DM. The role of AMPK in PVAT or the actions of PVAT have yet to be established, however. Activation of AMPK by pharmacological agents, such as metformin and thiazolidinediones, may modulate the activity of PVAT surrounding blood vessels and thereby contribute to their beneficial effect in cardiometabolic diseases. This review will provide a current perspective on how PVAT may influence vascular function via AMPK. We will also attempt to demonstrate how modulating AMPK activity using pharmacological agents could be exploited therapeutically to treat cardiometabolic diseases.

Long-term RNA persistence of porcine rubulavirus (PorPV-LPMV) after an outbreak of a natural infection: the detection of viral mRNA in sentinel pigs suggests viral transmission

The persistence of porcine rubulavirus (PorPV-LPMV) in five pigs that had survived an outbreak of a natural infection was determined. After the resolution of the outbreak, each animal was housed in an isolation pen together with one sentinel pig. Approximately every 2 months thereafter one group of animals was euthanized and tissue samples taken for virological and serological analysis. Infectious virus was not isolated from any samples; antibodies to PorPV-LPMV were detected in convalescent pigs by virus neutralisation test and blocking ELISA but not in sentinel pigs. PorPV-LPMV mRNA of the nucleoprotein (NP) and phosphoprotein (P) genes was detected by a nested polymerase chain reaction (nPCR) in samples of trigeminal and optic nerves, cervical spinal cord, tonsils, salivary gland, lung and pancreas from convalescent pigs. mRNA was also detected in the midbrain, corpus callosum, or olfactory bulb in four out of five pigs by nRT-PCR, this result was confirmed by the sequencing of a 260bp PCR product of P gene region. The highest average viral copies/μg of total RNA occurred in the olfactory bulb and pancreas tissues of convalescent pigs and midbrain, tonsil and pancreas of sentinel pigs housed with the convalescent pigs. Satellitosis and gliosis of the midbrain, olfactory bulb, corpus callosum, medulla oblongata or choroid plexus were microscopically observed in four convalescent pigs. The control pig remained negative in all tests. The results indicate that PorPV-LPMV mRNA persists and induces a durable humoral immune response in pigs that have recovered from a natural infection. After a possible reactivation of the virus, it was transmitted to sentinel pigs in contact with the convalescent pigs.

Choroid plexus papillomas in childhood

Chroid plexus papillomas account for only 0.4-0.6% of intracranial tumours at all ages and less than 5% in childhood. Two paediatric cases are reported to demonstrate the variability in clinical presentation, location and neurological outcome of this benign tumour. One case has been followed for 13 years.

USH1G with unique retinal findings caused by a novel truncating mutation identified by genome-wide linkage analysis

PURPOSE

Usher syndrome (USH) is an autosomal recessive disorder divided into three distinct clinical subtypes based on the severity of the hearing loss, manifestation of vestibular dysfunction, and the age of onset of retinitis pigmentosa and visual symptoms. To date, mutations in seven different genes have been reported to cause USH type 1 (USH1), the most severe form. Patients diagnosed with USH1 are known to be ideal candidates to benefit from cochlear implantation.

METHODS

Genome-wide linkage analysis using Affymetrix GeneChip Human Mapping 10K arrays were performed in three cochlear implanted Saudi siblings born from a consanguineous marriage, clinically diagnosed with USH1 by comprehensive clinical, audiological, and ophthalmological examinations. From the linkage results, the USH1G gene was screened for mutations by direct sequencing of the coding exons.

RESULTS

We report the identification of a novel p.S243X truncating mutation in USH1G that segregated with the disease phenotype and was not present in 300 ethnically matched normal controls. We also report on the novel retinal findings and the outcome of cochlear implantation in the affected individuals.

CONCLUSIONS

In addition to reporting a novel truncating mutation, this report expands the retinal phenotype in USH1G and presents the first report of successful cochlear implants in this disease.

Safety and pharmacokinetics of aciclovir in women following release from a silicone elastomer vaginal ring

OBJECTIVES

Systemic aciclovir and its prodrug valaciclovir are effective in treating and reducing recurrences of genital herpes simplex virus (HSV) and reducing transmission. Local aciclovir delivery, if it can achieve and maintain comparable intracellular genital tract levels, may be equally effective in the treatment and suppression of genital HSV. Intravaginal ring (IVR) delivery of aciclovir may provide pre-exposure prophylaxis against HSV acquisition.

METHODS

Tolerability and pharmacokinetics were evaluated in six HIV-negative women with recurrent genital HSV who switched their daily oral valaciclovir suppression to an aciclovir IVR for 7 days (n = 3) or 14 days (n = 3). Blood and cervicovaginal lavage (CVL) were collected after oral and IVR dosing to measure aciclovir concentrations and genital swabs were obtained to quantify HSV shedding by PCR.

RESULTS

The rings were well tolerated. Median plasma aciclovir concentrations were 110.2 ng/mL (IQR, 85.9-233.5) 12-18 h after oral valaciclovir. Little or no drug was detected in plasma following IVR dosing. Median (IQR) CVL aciclovir levels were 127.3 ng/mL (21-660.8) 2 h after oral valaciclovir, 154.4 ng/mL (60.7-327.5) 12-18 h after oral valaciclovir and 438 ng/mL (178.5-618.5) after 7 days and 393 ng/mL (31.6-1615) after 14 days of aciclovir ring use. Median CVL aciclovir levels 2 h after oral dosing were similar to levels observed 7 (P = 0.99) and 14 (P = 0.75) days after ring use. HSV DNA was not detected in genital swabs and there was no significant change in inflammatory mediators.

CONCLUSIONS

This first-in-human study demonstrated that an IVR could safely deliver mucosal levels of aciclovir similar to oral valaciclovir without systemic absorption. More intensive site-specific pharmacokinetic studies are needed to determine whether higher local concentrations are needed to achieve optimal drug distribution within the genital tract.

Dextran sodium sulfate inhibition of real-time polymerase chain reaction amplification: a poly-A purification solution

BACKGROUND

Dextran sulfate sodium (DSS) induces experimental colitis and promotes colitis-associated cancer in rodents. Here we document potent inhibition of real-time quantitative polymerase chain reaction (qPCR) using cDNA from DSS-exposed mouse tissues, which complicates gene expression analysis.

METHODS

We characterize DSS inhibition of qPCR in-vitro and in a wide array of murine tissues following ingestion of DSS. We examine different approaches to RNA purification prior to cDNA synthesis in order to optimize real-time polymerase chain reaction amplification and gene expression analysis.

RESULTS

DSS inhibits qPCR amplification of cDNA between 1 and 10 nM. Orally administered DSS interferes with qPCR amplification of cDNA derived from multiple tissues. Poly-A purification of DSS-exposed RNA allows reliable and cost-effective gene expression analysis in DSS-exposed tissue.

CONCLUSIONS

DSS is a potent inhibitor of real-time qPCR amplification and interferes with tissue-specific gene expression analysis in DSS-exposed mice. Poly-A purification of tissue-derived RNA results in reliable and cost-effective gene expression analysis in DSS-exposed mice.

A comprehensive introduction to the genetic basis of non-syndromic hearing loss in the Saudi Arabian population

BACKGROUND

Hearing loss is a clinically and genetically heterogeneous disorder. Mutations in the DFNB1 locus have been reported to be the most common cause of autosomal recessive non-syndromic hearing loss worldwide. Apart from DFNB1, many other loci and their underlying genes have also been identified and the basis of our study was to provide a comprehensive introduction to the delineation of the molecular basis of non-syndromic hearing loss in the Saudi Arabian population. This was performed by screening DFNB1 and to initiate prioritized linkage analysis or homozygosity mapping for a pilot number of families in which DFNB1 has been excluded.

METHODS

Individuals from 130 families of Saudi Arabian tribal origin diagnosed with an autosomal recessive non-syndromic sensorineural hearing loss were screened for mutations at the DFNB1 locus by direct sequencing. If negative, genome wide linkage analysis or homozygosity mapping were performed using Affymetrix GeneChip® Human Mapping 250K/6.0 Arrays to identify regions containing any known-deafness causing genes that were subsequently sequenced.

RESULTS

Our results strongly indicate that DFNB1 only accounts for 3% of non-syndromic hearing loss in the Saudi Arabian population of ethnic ancestry. Prioritized linkage analysis or homozygosity mapping in five separate families established that their hearing loss was caused by five different known-deafness causing genes thus confirming the genetic heterogeneity of this disorder in the kingdom.

CONCLUSION

The overall results of this study are highly suggestive that underlying molecular basis of autosomal recessive non-syndromic deafness in Saudi Arabia is very genetically heterogeneous. In addition, we report that the preliminary results indicate that there does not seem to be any common or more prevalent loci, genes or mutations in patients with autosomal recessive non-syndromic hearing loss in patients of Saudi Arabian tribal origin.

Systemic herpesvirus and morbillivirus co-infection in a striped dolphin (Stenella coeruleoalba)

During 2007 a dolphin morbillivirus epizootic affected the western Mediterranean and several striped dolphins (Stenella coeruleoalba) stranded on the Catalonian coasts. One of those animals had severe lymphoid depletion, necrosis and syncytial formation in lymph nodes and spleen, with large basophilic nuclear inclusions compatible with herpesvirus detected by immunohistochemical and ultrastructural examination. Non-suppurative encephalitis with associated morbillivirus antigen and morbillivirus antigen within alveolar macrophages were also observed. A pan-herpesvirus nested polymerase chain reaction amplified a sequence virtually identical to two cetacean herpesvirus sequences previously identified in systemic infections in an Atlantic Cuvier's beaked whale (Ziphius cavirostris) and in a Mediterranean striped dolphin. The herpesviral infection was probably secondary to the immunosuppression caused by the morbillivirus. To our knowledge, this is the first report of a cetacean co-infected by dolphin morbillivirus and herpesvirus with evidence of lesions attributable to both viruses.