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.

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.

Infestation of sheep with Psoroptes ovis, the sheep scab mite, results in recruitment of Foxp3(+) T cells into the dermis.

Regulatory T cells (Tregs) play a central role in maintenance of immune homeostasis by controlling harmful immune responses to inappropriate antigens and are thought to play a key role in modulating hypersensitivity reactions. Infestation of sheep with Psoroptes ovis results in a pronounced cutaneous hypersensitivity-type response, which appears to be crucial for mite survival. We hypothesize that (i) Tregs are involved in sheep scab lesions and (ii) Treg responses may crucially affect lesion development and subsequent mite survival. Foxp3 is a key transcription factor required for generation and maintenance of Tregs in rodents and humans, and is the most widely used marker for Tregs in these species. In this study, we sequence ovine foxp3 and show that it exhibits a high degree of homology with foxp3 from other species. Using a validated immunohistochemical staining technique, we demonstrate that infestation of sheep with P. ovis results in an influx of Foxp3(+) T cells into the skin. Future work will investigate the regulatory function of ovine Foxp3(+) T cells and determine whether the quality of the Treg response to P. ovis plays a role in individual susceptibility to the mite.

14-3-3 protein homologs required for the DNA damage checkpoint in fission yeast.

During the cell cycle, DNA is replicated and segregated equally into two daughter cells. The DNA damage checkpoint ensures that DNA damage is repaired before mitosis is attempted. Genetic studies of the fission yeast Schizosaccharomyces pombe have identified two genes, rad24 and rad25, that are required for this checkpoint. These genes encode 14-3-3 protein homologs that together provide a function that is essential for cell proliferation. In addition, S. pombe rad24 null mutants, and to a lesser extent rad25 null mutants, enter mitosis prematurely, which indicates that 14-3-3 proteins have a role in determining the timing of mitosis.

A novel mutant allele of Schizosaccharomyces pombe rad26 defective in monitoring S-phase progression to prevent premature mitosis.

A semipermissive growth condition was defined for a Schizosaccharomyces pombe strain carrying a thermosensitive allele of DNA polymerase delta (pol delta ts03). Under this condition, DNA polymerase delta is semidisabled and causes a delay in S-phase progression. Using a genetic strategy, we have isolated a panel of mutants that enter premature mitosis when DNA replication is incomplete but which are not defective for arrest in G2/M following DNA damage. We characterized the aya14 mutant, which enters premature mitosis when S phase is arrested by genetic or chemical means. However, this mutant is sensitive to neither UV nor gamma irradiation. Two genomic clones, rad26+ and cds1+, were found to suppress the hydroxyurea sensitivity of the aya14 mutant. Genetic analysis indicates that aya14 is a novel allele of the cell cycle checkpoint gene rad26+, which we have named rad26.a14. cds1+ is a suppressor which suppresses the S-phase feedback control defect of rad26.a14 when S phase is inhibited by either hydroxyurea or cdc22, but it does not suppress the defect when S phase is arrested by a mutant DNA polymerase. Analyses of rad26.a14 in a variety of cdc mutant backgrounds indicate that strains containing rad26.a14 bypass S-phase arrest but not G1 or late S/G2 arrest. A model of how Rad26 monitors S-phase progression to maintain the dependency of cell cycle events and coordinates with other rad/hus checkpoint gene products in responding to radiation damage is proposed.

The rad16 gene of Schizosaccharomyces pombe: a homolog of the RAD1 gene of Saccharomyces cerevisiae.

The rad10, rad16, rad20, and swi9 mutants of the fission yeast Schizosaccharomyces pombe, isolated by their radiation sensitivity or abnormal mating-type switching, have been shown previously to be allelic. We have cloned DNA correcting the UV sensitivity or mating-type switching phenotype of these mutants and shown that the correcting DNA is encompassed in a single open reading frame. The gene, which we will refer to as rad16, is approximately 3 kb in length, contains seven introns, and encodes a protein of 892 amino acids. It is not essential for viability of S. pombe. The predicted protein is the homolog of the Saccharomyces cerevisiae RAD1 protein, which is involved in an early step in excision-repair of UV damage from DNA. The approximately 30% sequence identity between the predicted proteins from the two yeasts is distributed throughout the protein. Two-hybrid experiments indicate a strong protein-protein interaction between the products of the rad16 and swi10 genes of S. pombe, which mirrors that reported for RAD1 and RAD10 in S. cerevisiae. We have identified the mutations in the four alleles of rad16. They mapped to the N-terminal (rad10), central (rad20), and C-terminal (rad16 and swi9) regions. The rad10 and rad20 mutations are in the splice donor sequences of introns 2 and 4, respectively. The plasmid correcting the UV sensitivity of the rad20 mutation was missing the sequence corresponding to the 335 N-terminal amino acids of the predicted protein. Neither smaller nor larger truncations were, however, able to correct its UV sensitivity.

The rad18 gene of Schizosaccharomyces pombe defines a new subgroup of the SMC superfamily involved in DNA repair.

The rad18 mutant of Schizosaccharomyces pombe is very sensitive to killing by both UV and gamma radiation. We have cloned and sequenced the rad18 gene and isolated and sequenced its homolog from Saccharomyces cerevisiae, designated RHC18. The predicted Rad18 protein has all the structural properties characteristic of the SMC family of proteins, suggesting a motor function--the first implicated in DNA repair. Gene deletion shows that both rad18 and RHC18 are essential for proliferation. Genetic and biochemical analyses suggest that the product of the rad18 gene acts in a DNA repair pathway for removal of UV-induced DNA damage that is distinct from classical nucleotide excision repair. This second repair pathway involves the products of the rhp51 gene (the homolog of the RAD51 gene of S. cerevisiae) and the rad2 gene.

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.

Identification and characterization of new elements involved in checkpoint and feedback controls in fission yeast.

To investigate the mechanisms that ensure the dependency relationships between cell cycle events and to investigate the checkpoints that prevent progression through the cell cycle after DNA damage, we have isolated mutants defective in the checkpoint and feedback control pathways. We report the isolation and characterization of 11 new loci that define distinct classes of mutants defective in one or more of the checkpoint and feedback control pathways. Two mutants, rad26.T12 and rad27.T15, were selected for molecular analysis. The null allele of the rad26 gene (rad26.d) shares the phenotype reported for the "checkpoint rad" mutants rad1, rad3, rad9, rad17, and hus1, which are defective in the radiation checkpoint and in the feedback controls that ensure the order of cell cycle events. The null allele of the rad27 gene (rad27.d) defines a new class of Schizosaccharomyces pombe mutant. The rad27 complementing gene codes for a putative protein kinase that is required for cell cycle arrest after DNA damage but not for the feedback control that links mitosis to the completion of prior DNA synthesis (the same gene has recently been described by Walworth et al. (1993) as chk1). These properties are similar to those of the rad9 gene of Saccharomyces cerevisiae. A comparative analysis of the radiation responses in rad26.d, rad26.T12, and rad27.d cells has revealed the existence of two separable responses to DNA damage controlled by the "checkpoint rad" genes. The first, G2 arrest, is defective in rad27.d and rad26.d but is unaffected in rad26.T12 cells. The second response is not associated with G2 arrest after DNA damage and is defective in rad26.d and rad26.T12 but not rad27.d cells. A study of the radiation sensitivity of these mutants through the cell cycle suggests that this second response is associated with S phase and that the checkpoint rad mutants, in addition to an inability to arrest mitosis after radiation, are defective in an S phase radiation checkpoint.

[Quantification of bladder-outlet obstruction in males: standard method vc VBN method]. / Quantification de l'obstruction chez l'homme: comparaison des méthodes usuelles avec la méthode VBN.

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.

Vectors for the expression of tagged proteins in Schizosaccharomyces pombe.

A series of vectors is described which enables the episomal expression of proteins fused to different tag sequences in Schizosaccharomyces pombe. Proteins can be expressed with their amino termini fused to GFP/EGFP, three copies of the HA or Pk epitopes or a combined tag which contains two copies of the myc epitope and six histidine residues (MH). Fusion of the carboxyl terminus of a protein to a tag is possible with GFP/EGFP or Pk. Expression of the fusion proteins is controlled by the medium strength mutant version of the regulatable nmt1 promoter.

A new external urethral occlusive device for female urinary incontinence.

OBJECTIVE: Determine the efficacy of a new external anti-incontinence urethral device. METHODS: A before-after 1 month trial, open longitudinal study of 155 women complaining of urinary incontinence recruited from a referral urogynecology practice and local media advertising was performed. Primary outcomes included assessing the efficacy of the device using visual analogue scales, quality-of-life questionnaires, 1- and 48-hour standardized pad tests, and voiding diary. Secondary outcomes consisted of the evaluation of the adverse effects and the clinical profile of patients willing to use the device after study completion. RESULTS: Ninety-six (62%) of 155 women enrolled completed the study. Scores on the visual analogue scales improved for the symptoms of stress incontinence, urgency, and urge incontinence (P < .001). The score for irritation/discomfort increased (P < .001). Data from diaries showed that 38 (44%, n = 86) patients were dry. Of 454 recorded patient-days, 325 (72%) were dry days. On pad testing, incontinence was cured in 49% (1-hour pad test, n = 59, P < .001) and 44% (48-hour pad test, n = 32, P < .001) of patients. Quality-of-life scores were significantly improved in 48% (n = 96, Incontinence Impact Questionnaire, P < .001) and 32% (n = 96, Urogenital Distress Inventory, P < .001) of patients. There was no increase in bacteriuria. After study completion, 61 (39%) women chose to continue using the device, but this was not predictable from baseline data. CONCLUSION: Use of this device resulted in a significant reduction in incontinence and improvement in quality-of-life issues with minimal adverse events in the majority of women. This new anti-incontinence device could become a useful addition to the armamentarium of nonsurgical options.

Clinical comparison of bladder contractility parameters calculated from isometric contractions and pressure-flow studies.

Parameters describing the contractility of the urinary bladder can be calculated from both isometric contractions and pressure-flow studies. The first method has the advantage of making very little demand either on the patient or on the urodynamicist, and the disadvantage of yielding a parameter that is not clearly related to muscle physiology. The second method demands more from both patient and experimenter but yields straightforward parameters. For a group of 86 patients with mixed pathologic findings, a correlation between the two types of parameters was demonstrated, showing that both methods test, at least partly, the same mechanism.

Pressure-flow studies of micturition.

The purpose of pressure-flow studies is to identify and quantify the abnormalities of bladder function (bladder outlet obstruction) that underlie disorders of voiding already demonstrated in simpler ways. Techniques of measurement and data quality control are of primary importance. Different methods for analyzing bladder outlet obstruction in the male like the Abrams-Griffiths nomogram and the linPURR have different aims but give broadly consistent results. Methods for assessing detrusor contractility and obstruction in the female patient are briefly discussed.

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.

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.

Dynamics of the upper urinary tract: I. Peristaltic flow through a distensible tube of limited length.

A theoretical analysis and numerical solutions are presented for viscosity-dominated flow through a uniform, highly distensible tube with a slit-shaped cross section undergoing peristalsis. At flow rates below an intrinsic upper limit to the peristaltic carrying capacity of the tube, provided that there is always at least one peristaltic contraction wave in the tube, two different types of steady peristaltic flow are possible, with well defined boluses separated by regions where the tube is nearly completely occluded (flow with isolated boluses and flow with boluses in contact). Above this limit two other non-steady types of flow are possible, in which the boluses are less well defined and the contraction waves are in general not completely occlusive (flow with leaky boluses and open-tube flow). In flow with isolated boluses, boluses in contact and leaky boluses, the upstream pressure is determined by the mechanical properties (active and passive) of the tube undergoing peristalsis. In open-tube flow it is primarily determined by the resistance of the outlet from the tube.

Dynamics of the upper urinary tract: II. The effect of variations of peristaltic frequency and bladder pressure on pyeloureteral pressure/flow relations.

The dynamics of pyeloureteral flow is described when there is no peristalsis and for peristalsis of high and intermediate frequencies, on the assumption that the ureter is uniform except in the mid-ureter and at the outlet. The possibility of upstream transmission of bladder pressure variations to the renal pelvis is considered. The overall behaviour depends on three principal variables, the maximum tube pressure in the contraction waves, the intrinsic peristaltic carrying capacity and the peristaltic frequency f, expressed in the form fT where T is the time for a peristaltic contraction wave to sweep through the ureter. At intermediate peristaltic frequencies (fT less than but comparable with one) oscillatory flow patterns can occur, in which periods of peristaltically driven flow alternate with extraperistaltic periods of flow through the open ureter. The kidney is better isolated from bladder pressure variations when the peristaltic frequency is high, but high peristaltic frequency can by itself lead to elevated renal pelvic pressure if the flow rate is high. Experimental observations in pigs are presented to support these conclusions.

The role of videourodynamic studies in diagnosis and treatment of vesicoureteral reflux.

From January 1986 to January 1988, 63 children with 95 refluxing ureters have been studied in a prospective study with videourodynamic examination. All children with reflux grades I, II, and III received antibacterial treatment. Surgical treatment was adopted for reflux grades IV and V, provided detrusor instability had been excluded. However, if there was detrusor instability, anticholinergic drugs and antibacterial treatment were given in all grades of reflux and videourodynamic examination was repeated after 3 to 6 months and after 12 months of therapy. Bilateral reflux was found in 22 of 38 patients with a stable bladder, and reimplantation was performed in 11 patients with 18 refluxing ureters. In 25 children with 35 refluxing ureters of various grades of reflux, detrusor instability was found and unilateral reflux was noted more frequently than bilateral reflux. Surgery was necessary for only five children, because in the majority of the patients detrusor instability and reflux could be treated by anticholinergic drugs and antibacterial treatment. For the decision as to which treatment should be given in vesicoureteral reflux, a videourodynamic study is mandatory.

Exploratory investigations of hypervelocity intact capture spectroscopy.

The ability to capture hypervelocity projectiles intact opens a new technique available for hypervelocity research. A determination of the reactions taking place between the projectile and the capture medium during the process of intact capture is extremely important to an understanding of the intact capture phenomenon, to improving the capture technique, and to developing a theory describing the phenomenon. The intact capture of hypervelocity projectiles by underdense media generates spectra, characteristic of the material species of projectile and capture medium involved. Initial exploratory results into real-time characterization of hypervelocity intact capture techniques by spectroscopy include ultra-violet and visible spectra obtained by use of reflecting gratings, transmitting gratings, and prisms, and recorded by photographic and electronic means. Spectrometry proved to be a valuable real-time diagnostic tool for hypervelocity intact capture events, offering understanding of the interactions of the projectile and the capture medium during the initial period and providing information not obtainable by other characterizations. Preliminary results and analyses of spectra produced by the intact capture of hypervelocity aluminum spheres in polyethylene (PE), polystyrene (PS), and polyurethane (PU) foams are presented. Included are tentative emission species identifications, as well as gray body temperatures produced in the intact capture process.