Arteriosclerosis in the ventral aorta and epicarditis in the bulbus arteriosus of Atlantic salmon (Salmo salar L)

Spontaneous mortality of seemingly healthy, farmed Atlantic salmon (Salmo salar L) is an increasing problem in Norwegian aquaculture. In this study, we present a morphological study of the previously undescribed syndrome of arteriosclerosis of the ventral aorta and epicarditis of the adjacent bulbus arteriosus found in farmed Atlantic salmon, with wild-captured fish as a control group. Both the ventral aorta and epicardium are vital for correct arterial compliance and vascular resistance in the respiratory capillaries of the gills. We discuss the possible implications of ventral aorta arteriosclerosis and epicarditis for blood vascular health and in particular for the increasing frequency of spontaneous gill bleeding in farmed salmon. As both these conditions primarily occur in farmed salmon, we suggest that they should be considered pathological.

Cellular differentiation and proliferation in the ovine lung during gestation and early postnatal development

This study investigates epithelial cell differentiation and proliferation in specific anatomical regions of the ovine lung during prenatal and postnatal development. Immunohistochemistry was used to identify ciliated epithelial cells, Clara cells, neuroepithelial bodies and type II pneumocytes in the lungs of preterm (67, 127 and 140 days of gestation), full-term (147 days) and postnatal (9, 16 and 91 days old) lambs. Differentiation of ciliated epithelial cells was seen at 67 days of gestation and at term for Clara cells. Neuroepithelial bodies were first detected at 127 days of gestation. From 16 to 91 days of age there was a significant (P <0.05) increase in beta-tubulin (present in ciliated epithelial cells) and Clara cell protein (present in Clara cells) in multiple regions of the lung. Detection of Ki67, a marker of proliferation, in preterm lambs showed a reduction in proliferation index in multiple anatomical regions of the lung between 70 days of gestation and term. Cell proliferation increased following parturition, and then decreased between 16 and 91 days of age, with the largest reduction occurring in the alveolar compartment. Knowledge of which cells are present at specific times of lung development provides valuable information on the anatomy of the ovine lung, improving its use as a model for ovine and human neonatal disease. In addition, the antibodies used here will be valuable for future studies requiring the identification and quantification of respiratory epithelial cell phenotypes in the sheep lung.

The micturition switch and its forebrain influences

Dr DeGroat and Wickens has reviewed the central neural mechanisms controlling the lower urinary tract with a major focus on the brain stem circuitry that mediates the switch-like characteristics of micturition, in particular the periaqueductal grey and the pontine micturition centre (de 2012). The review culminates in a computer model of how the brainstem switch operates in animals in which forebrain influences on micturition have been removed by decerebration. In this complementary paper, we review the mechanisms of forebrain involvement in the voluntary control of human micturition and the maintenance of continence with evidence based heavily on the results of functional brain imaging experiments.

Autoimmune progesterone dermatitis: a diagnosis easily missed

Autoimmune progesterone dermatitis (AIPD) is a rare, poorly characterized dermatosis, with about 60 previously reported cases. It typically undergoes cyclical flares relating to the menstrual cycle, especially the luteal phase, when levels of progesterone are at their highest. We report the case of a 34-year-old woman with an 8-year history of a profoundly pruritic eruption, associated with her menstrual cycle, in whom the diagnosis had proved elusive. Buserelin nasal spray resulted in complete clearance. AIPD is a diagnosis to consider in intractable eruptions in women, particularly if there is cyclical variation.

[Quantification of bladder-outlet obstruction in males: standard method vc VBN method]

GOAL

To compare the merits of two methods, standard (Abrams-Griffiths number, Schafer's classification, etc.) and VBN, to study bladder-outlet obstruction in men with benign prostatic hyperplasia (BPH).

MATERIAL AND METHODS

The parameters deduced from both methods and from repeated pressure-flow studies were computed for a population of patients with BPH. Correlation coefficients between standard and VBN parameters were systematically evaluated. Test-retest reliability and inter-rater reliability of the VBN parameters were investigated.

RESULTS

The VBN obstruction parameter was linearly corelated to the A-G number (R = 0.992) and thus is related to the provisional ICS obstruction nomogram. A simple modification to the standard index projected isometric pressure (PIP) yields an mPIP parameter strongly correlated with the VBN detrusor contraction-strength parameter (R = 0.962). VBN analysis reveals minor phenomena such as premature fading of the detrusor contraction to be responsible for much of the void-to-void variability of pressure-flow studies. Consequently, the primary VBN obstruction and contraction-strength parameters exhibit better test-retest and inter-rater reliability than the standard parameters and are less sensitive to changes in testing circumstances (bladder volume, urethral catheter size and psychological factors).

CONCLUSION

With the standard approach to test bladder obstruction, two values: A-G and mPIP, derived from pressure-flow studies, best qualify the patient's voiding status. These parameters are simple to calculate but are sensitive to testing variations and minor phenomena. The VBN approach is more complicated, but its parameters for obstruction and detrusor contraction strength are less dependent on testing variations.

Conservation and loss of the ERV3 open reading frame in primates

The human endogenous retrovirus ERV3 possesses an open reading frame for a truncated envelope, which is expressed as mRNA and protein. Here we examine the env sequence in primates for evidence of evolutionary conservation. ERV3 sequences were amplified by PCR from genomic DNA of great ape and Old World primates but not from New World primates or gorilla, suggesting an integration event more than 30 million years ago with a subsequent loss in one species. In the chimpanzee, the protein sequence of Env is 98.18% identical to that of human. In other species the identity falls (93.71% in rhesus macaque) in proportion to the separation from the human lineage. Start and stop codons and domains of functional significance in the envelope protein are conserved. The evolutionary conservation of the ERV3 envelope suggests a beneficial function, though the loss from gorilla shows that it is not essential for survival or reproduction.

Autoantibodies to human endogenous retrovirus-K are frequently detected in health and disease and react with multiple epitopes

A number of studies have found increased levels of antibodies to human endogenous retroviruses (HERVs) in autoimmune rheumatic diseases. It is not clear whether this immune response is driven by the HERV itself or by cross-reactions with an exogenous virus or an autoantigen. To address this question, we examined the antibody response to the Env protein of two closely related members of the HERV-K family, HERV-K10 and IDDMK1,222. By immunoblotting of recombinant proteins, antibodies were found in 32-47% of 84 sera from patients with autoimmune rheumatic disease, and 29% of 35 normal controls. Epitope mapping with overlapping 15mers identified multiple reactive peptides on both antigens, with one (GKTCPKEIPKGSKNT) containing immunodominant epitope(s). By ELISA, the median titre of antibody to this peptide was significantly increased in 39 patients with SLE compared to 39 healthy controls and 86 patients with other rheumatic diseases (P < 0.003). We have shown that there is a high frequency of IgG antibodies to HERV-K env sequences in human sera, both in health and autoimmune rheumatic disease, and that the response is to multiple epitopes. This supports the hypothesis that the autoimmune response to HERV-K is antigen-driven and may be an early stage in the chain of events that leads to tolerance breakdown to other autoantigens.

Quest for a detrusor overactivity index

PURPOSE

Urge incontinence, which is the predominant type of geriatric incontinence, is generally attributed to detrusor overactivity. However, detrusor overactivity is present in up to half of continent elderly individuals. We postulated that detrusor overactivity associated with urge incontinence would be more severe but there are no established criteria for judging severity. Using urge incontinence frequency as a yardstick and controlling for nonurodynamic contributing factors we sought intrinsic lower urinary tract parameters that reflect detrusor overactivity severity. We postulated that parameters in 1 or more of 5 domains would be important, namely characteristics of uninhibited contraction, bladder capacity, bladder proprioception, detrusor contractility and sphincter adequacy.

MATERIALS AND METHODS

We analyzed data on 79 community dwelling incontinent individuals older than 60 years old. All subjects had urge incontinence on a 4-day voiding record and underwent multichannel videourodynamics. We examined the associations of urge incontinence frequency with the postulated key factors.

RESULTS

Multivariable analysis revealed that 24-hour urine output and functional bladder capacity consistently predicted urge incontinence frequency. Bladder proprioception was significant in some models. Uninhibited contraction pressure was another predictor. Surprisingly higher uninhibited contraction pressure was associated with lower urge incontinence frequency. This negative correlation was more pronounced in a subgroup with a less adequate sphincter but absent in those with good sphincter function, implying that low uninhibited contraction pressure does not necessarily indicate less severe detrusor overactivity but rather reflects sphincter inadequacy in many patients. Age was not independently associated with urge incontinence frequency.

CONCLUSIONS

We identified functional bladder capacity as a measure of detrusor overactivity severity. The measure commonly used, namely uninhibited contraction pressure, is inappropriate because it is severely confounded by sphincter function, especially in older individuals. Furthermore, we confirmed that urine output, and possibly bladder sensation and sphincter strength modify the clinical manifestation of detrusor overactivity.

Quest for a detrusor overactivity index

PURPOSE

Urge incontinence, which is the predominant type of geriatric incontinence, is generally attributed to detrusor overactivity. However, detrusor overactivity is present in up to half of continent elderly individuals. We postulated that detrusor overactivity associated with urge incontinence would be more severe but there are no established criteria for judging severity. Using urge incontinence frequency as a yardstick and controlling for nonurodynamic contributing factors we sought intrinsic lower urinary tract parameters that reflect detrusor overactivity severity. We postulated that parameters in 1 or more of 5 domains would be important, namely characteristics of uninhibited contraction, bladder capacity, bladder proprioception, detrusor contractility and sphincter adequacy.

MATERIALS AND METHODS

We analyzed data on 79 community dwelling incontinent individuals older than 60 years old. All subjects had urge incontinence on a 4-day voiding record and underwent multichannel videourodynamics. We examined the associations of urge incontinence frequency with the postulated key factors.

RESULTS

Multivariable analysis revealed that 24-hour urine output and functional bladder capacity consistently predicted urge incontinence frequency. Bladder proprioception was significant in some models. Uninhibited contraction pressure was another predictor. Surprisingly higher uninhibited contraction pressure was associated with lower urge incontinence frequency. This negative correlation was more pronounced in a subgroup with a less adequate sphincter but absent in those with good sphincter function, implying that low uninhibited contraction pressure does not necessarily indicate less severe detrusor overactivity but rather reflects sphincter inadequacy in many patients. Age was not independently associated with urge incontinence frequency.

CONCLUSIONS

We identified functional bladder capacity as a measure of detrusor overactivity severity. The measure commonly used, namely uninhibited contraction pressure, is inappropriate because it is severely confounded by sphincter function, especially in older individuals. Furthermore, we confirmed that urine output, and possibly bladder sensation and sphincter strength modify the clinical manifestation of detrusor overactivity.

Characterization of a late entry event in the replication cycle of human immunodeficiency virus type 2

Certain human cell lines and primary macrophage cultures are restricted to infection by some primary isolates of human immunodeficiency virus type 2 (HIV-2), although early steps of the viral life cycle such as fusion at the plasma membrane and reverse transcription are fully supported. The late postintegration events, transcription, translation, assembly, budding, and maturation into infectious virions are functional in restrictive cells. Apart from primary macrophages, the restrictive cell types are actively dividing, and nuclear import of preintegration complexes (PICs) is not required for infection. We therefore postulate that the PICs are trapped in a cellular compartment, preventing subsequent steps in the replication cycle that lead to integration of the provirus. To test this we showed that HIV-2 particles pseudotyped with vesicular stomatitis virus envelope G protein, which delivers HIV into an endocytic compartment, could overcome the block to infection. We suggest that delivery of the viral core into an appropriate cellular compartment is a critical step during the entry process of HIV.

Multiple groups of novel retroviral genomes in pigs and related species

In view of the concern over potential infection hazards in the use of porcine tissues and organs for xenotransplantation to humans, we investigated the diversity of porcine endogenous retrovirus (PERV) genomes in the DNA of domestic pigs and related species. In addition to the three known envelope subgroups of infectious gamma retroviruses (PERV-A, -B, and -C), classed together here as PERV group gamma 1, four novel groups of gamma retrovirus (gamma 2 to gamma 5) and four novel groups of beta retrovirus (beta 1 to beta 4) genomes were detected in pig DNA using generic and specific PCR primers. PCR quantification indicated that the retroviral genome copy number in the Landrace x Duroc F(1) hybrid pig ranged from 2 (beta 2 and gamma 5) to approximately 50 (gamma 1). The gamma 1, gamma 2, and beta 4 genomes were transcribed into RNA in adult kidney tissue. Apart from gamma 1, the retroviral genomes are not known to be infectious, and sequencing of a small number of amplified genome fragments revealed stop codons in putative open reading frames in several cases. Analysis of DNA from wild boar and other species of Old World pigs (Suidae) and New World peccaries (Tayassuidae) showed that one retrovirus group, beta 2, was common to all species tested, while the others were present among all Old World species but absent from New World species. The PERV-C subgroup of gamma1 genomes segregated among domestic pigs and were absent from two African species (red river hog and warthog). Thus domestic swine and their phylogenetic relatives harbor multiple groups of hitherto undescribed PERV genomes.

Endogenous retroviruses in the human genome sequence

The human genome contains many endogenous retroviral sequences, and these have been suggested to play important roles in a number of physiological and pathological processes. Can the draft human genome sequences help us to define the role of these elements more closely?

Role of fission yeast primase catalytic subunit in the replication checkpoint

To investigate the cell cycle checkpoint response to aberrant S phase-initiation, we analyzed mutations of the two DNA primase subunit genes of Schizosaccharomyces pombe, spp1(+) and spp2(+) (S. pombe primase 1 and 2). spp1(+) encodes the catalytic subunit that synthesizes the RNA primer, which is then utilized by Polalpha to synthesize the initiation DNA. Here, we reported the isolation of the fission yeast spp1(+) gene and cDNA and the characterization of Spp1 protein and its cellular localization during the cell cycle. Spp1 is essential for cell viability, and thermosensitive mutants of spp1(+) exhibit an allele-specific abnormal mitotic phenotype. Mutations of spp1(+) reduce the steady-state cellular levels of Spp1 protein and compromised the formation of Polalpha-primase complex. The spp1 mutant displaying an aberrant mitotic phenotype also fails to properly activate the Chk1 checkpoint kinase, but not the Cds1 checkpoint kinase. Mutational analysis of Polalpha has previously shown that activation of the replication checkpoint requires the initiation of DNA synthesis by Polalpha. Together, these have led us to propose that suboptimal cellular levels of polalpha-primase complex due to the allele-specific mutations of Spp1 might not allow Polalpha to synthesize initiation DNA efficiently, resulting in failure to activate a checkpoint response. Thus, a functional Spp1 is required for the Chk1-mediated, but not the Cds1-mediated, checkpoint response after an aberrant initiation of DNA synthesis.

Validation and use of a finite element model of C-2 for determination of stress and fracture patterns of anterior odontoid loads

OBJECT

The finite element (FE) method is a powerful tool for the analysis of stress patterns of anatomical structures. In this study a highly refined FE model of C-2 was created and validated. The model was then used to characterize stress patterns, predicted fracture patterns, and transitions between Type II and Type III odontoid fractures.

METHODS

An anatomically accurate three-dimensional model of C-2 was created from computerized tomography data obtained from the Visible Human Project. The C-2 model was broken down into an FE mesh consisting of 32,815 elements and 40,969 nodes. For validation, the FE model was constrained and loaded to simulate that used in previous biomechanical studies. The validated model was then loaded in an iterative fashion, varying the orientation of the load within the validated range. A matrix of stress plots was created for comparative analysis. Results of the validation testing closely correlated with those obtained in previous biomechanical testing. Pure extension loading produced a Type III stress pattern with maximum stress of 134 MPa. Loading at 45 degrees produced a Type II stress distribution with a maximum stress of 123 MPa. These stresses are within 3% and 11%, respectively, of the reported yield stress of cortical bone (138 MPa). In the second portion of the study, systematic variation in the orientation of the load vector revealed that higher stresses were associated with increased lateral angulation and increasing upward inclination of the load vectors. A transition from a Type III to Type II pattern occurred with lateral orientations greater than 15 degrees and with compressive loads of 45 degrees.

CONCLUSIONS

The validated C-2 FE model described in this study both qualitatively and quantitatively was able to simulate the behavior of the C-2 vertebra in biomechanical testing. In this study the authors demonstrate the utility of the FE method when used in conjunction with traditional biomechanical testing.

Rheumatoid arthritis: a viral aetiology?

Viruses are often proposed as potential aetiological agents in rheumatoid arthritis (RA). However, this hypothesis is based primarily on circumstantial evidence rather than on experimental data. This editorial discusses specific viral candidates for RA and highlights some of the difficulties in proving disease causation.

Human retrovirus-5 in rheumatic disease

It has long been suggested that retroviral infection may play a role in the pathogenesis of autoimmune rheumatic disease. Particles resembling retroviruses have been reported in tissue from patients with Sjögren's syndrome, lupus and rheumatoid arthritis, and molecular mimicry between retroviral antigens and host proteins has been proposed as a mechanism of induction of autoimmunity. Since 1980, four distinct human infectious retroviruses have been discovered, HTLV-I, HTLV-II, HIV-1 and HIV-2. We recently cloned part of a new human retrovirus genome, designated human retrovirus-5 (HRV-5) and demonstrated that this is not endogenous and is therefore a novel infectious retrovirus. Because symptoms resembling arthritis, polymyositis and Sjögren's syndrome occur in individuals infected with HTLV-I and HIV-1, we investigated the possibility that HRV-5 was associated with idiopathic rheumatic disease. Using nested PCR, HRV-5 we demonstrated that proviral DNA was present in approximately 50% of synovial samples of arthritic joints and was also found in over 10% of blood samples of patients with rheumatoid arthritis and systemic lupus erythematosus. HRV-5 proviral DNA was not detectable in affected tissues of autoimmune diseases and was found in only one of over 200 tissues taken at autopsy from non-rheumatoid patients. Sequence analysis of the amplified viral segment showed genetic variation between samples with maintenance of the open reading frame typical of a replicating infectious retrovirus. Thus HRV-5 appears to be a human retrovirus found with a very low genome copy number in most tissues, but which is increased to detectable levels in inflamed joints and blood from patients with rheumatic disease. Whether HRV-5 is aetiologically important in these diseases remains to be determined.

Detection of human retrovirus 5 in patients with arthritis and systemic lupus erythematosus

OBJECTIVE

To examine whether human retrovirus 5 (HRV-5) infection is associated with autoimmune rheumatic disease.

METHODS

DNA from patients with various disorders including inflammatory diseases and from normal subjects was tested by nested polymerase chain reaction (PCR) for HRV-5 proviral DNA. Positive results were confirmed by DNA sequencing.

RESULTS

HRV-5 proviral DNA was detected in 53% of synovial samples from arthritic joints, in 12% of blood samples from patients with rheumatoid arthritis (RA), and in 16% of blood samples from patients with systemic lupus erythematosus. In contrast, it was not detectable by PCR of affected tissues from patients with several other autoimmune diseases and was found in only 1 of >200 tissue specimens obtained at autopsy from non-RA patients. Sequence analysis of the amplified viral segment showed genetic variation between samples with maintenance of the open reading frame, typical of a replicating infectious retrovirus.

CONCLUSION

This is the first report of the frequent detection of HRV-5 in any disease. We propose that the possible involvement of HRV-5 in autoimmune and rheumatic disease should be investigated further.

MR imaging of pelvic floor continence mechanisms in the supine and sitting positions

OBJECTIVE

Our goal was to determine the anatomic differences in pelvic floor anatomy for continent women and women with stress incontinence using MR imaging and to assess whether these anatomic differences depend on the position of the subject during imaging.

SUBJECTS AND METHODS

Eight continent volunteers and eight women with stress incontinence underwent MR imaging in the supine and sitting positions. For imaging, we used an open-configuration 0.5-T magnet. T2-weighted images were obtained in the midline sagittal plane with subjects at rest and at maximal pelvic floor strain in 5 sec using a modified fast spin-echo sequence. In the axial plane, thin-section T2-weighted images were obtained with subjects at rest using a standard fast spin-echo technique. Images were evaluated for mobility of the urethra and bladder neck and for integrity of the vagina, levator ani, and supporting fascia.

RESULTS

Pelvic floor laxity and abnormalities of the supporting fascia were more common in incontinent women than in continent women. Both descent of the bladder neck when subjects strained and the posterior urethrovesical angle were not significantly greater when subjects were measured in the sitting position (p < .1).

CONCLUSION

Changes of pelvic floor laxity related to incontinence can be seen with subjects in both the supine and the sitting positions but are increased in the sitting position.

Videourodynamic diagnosis of occult genuine stress incontinence in patients with anterior vaginal wall relaxation

OBJECTIVE

To (1) utilize videourodynamics, the gold standard, to assess the prevalence of occult genuine stress incontinence (GSI) among preoperative patients with symptomatic anterior vaginal wall relaxation and (2) identify urodynamic discriminators that might help predict occult GSI.

METHODS

In this prospective study, videourodynamic evaluation was performed on 48 consecutive patients presenting for preoperative urodynamic evaluation of anterior vaginal wall prolapse. Patients with occult GSI were identified by urodynamic testing with and without Gehrung pessary support of the bladder base during stress maneuvers. Variables from the history, physical examination, and videourodynamics were then analyzed.

RESULTS

The overall incidence of occult GSI was 25% (22.7% in the pelvic organ prolapse [POP] group and 26.9% in the POP-UI group). Patients with occult GSI were not identifiable on history but did have a higher incidence of late first sensation, open bladder neck at rest, and hypermobility on imaging with videourodynamics.

CONCLUSION

This study suggests that one quarter of women presenting with anterior wall relaxation with or without incontinence symptoms have occult GSI. Given this high prevalence, preoperative evaluation with urodynamics, possibly videourodynamics, utilizing bladder base support is justified if the data are substantiated in a larger, definitive study. Patients with a late first sensation, open bladder neck, and hypermobility may have a higher incidence of occult GSI.