Modeling the economic impacts of mobility scores in dairy cows under Irish spring pasture-based management

Moderate to severe forms of suboptimal mobility on dairy cows are associated with yield losses, whereas mild forms of suboptimal mobility are associated with elevated somatic cell count and an increased risk to be culled. Although the economic consequences of severe forms of suboptimal mobility (also referred as clinical lameness) have been studied extensively, the mild forms are generally ignored. Therefore, the aim of the current study was to determine the economic consequences associated with varying prevalence and forms of suboptimal mobility within spring calving, pasture-based dairy herds. A new submodel predicting mobility scores was developed and integrated within an existing pastured-based herd dynamic model. Using a daily timestep, this model simulates claw disorders, and the consequent mobility score of individual cows. The impact of a cow having varying forms of suboptimal mobility on production and reproduction was simulated. The economic impact was simulated including treatment costs, as well as the production and reproductive impacts of varying levels of suboptimal mobility. Furthermore, different genetic predispositions for mobility issues and their interaction with herd-level management associated with each level of suboptimal mobility were simulated. Overall, 13 scenarios were simulated, representing a typical spring calving, pasture-based dairy herd with 100 cows. The first scenario represents a perfect herd wherein 100% of the cows had mobility score 0 (optimal mobility) throughout the lactation. The remaining 12 scenarios represent a combination of (1) 3 different herd-management levels, and (2) 4 different levels of a genetic predisposition for suboptimal mobility. The analysis showed that a 17% decrease in farm net profit was achieved in the worst outcome (wherein just 5% of the herd had optimal mobility) compared with the perfect herd. This was due to reduced milk yield, increased culling, and increased treatment costs for mobility issues compared the ideal scenario.

Effect of feeding single-dam or pooled colostrum on maternally derived immunity in dairy calves

The role of colostrum management in providing adequate immunological protection to neonatal calves has been widely investigated, and thresholds for colostrum quality, as well as optimum volume and timing for colostrum feeding have been established. However, limited information is available on the effect of colostrum source (single dam or pooled) on passive immunity, as well as subsequent antibody survival in the calf. This study aimed to assess the effect of feeding single-dam colostrum (own and other dam) or pooled colostrum on transfer of passive immunity, and also investigate the rate of depletion of disease-specific antibodies among dairy calves. In total, 320 cows and 119 dairy heifer calves were enrolled in the study. Calves were blood-sampled immediately after birth and received either own-dam, other-dam, or pooled colostrum. Calves were blood-sampled at 24 h to assess serum IgG concentrations and at monthly intervals thereafter to document disease-specific antibody survival. Mean colostrum IgG concentration was higher for other-dam treatment group, whereas own-dam and pooled treatments were similar. For all treatment groups, the mean IgG concentration was >80 mg/mL, exceeding the quality threshold of 50 mg/mL. Mean calf serum IgG concentration was lower for calves fed pooled colostrum compared with those that received colostrum from a single cow. There was a negative association with 24-h serum IgG and calf birth bodyweight; calves <30 kg at birth had the highest 24-h serum IgG concentration. Survival of antibodies to bovine viral diarrhea, Salmonella infection, leptospirosis, bovine parainfluenza 3 virus, bovine respiratory syncytical virus, rotavirus, and coronavirus was not associated with colostrum source; however, antibodies to infectious bovine rhinotracheitis had a greater period of survival among calves fed own-dam colostrum. We found that feeding single-dam colostrum can thus improve calf immunity through increased serum IgG levels and antibody survival rates. Furthermore, we hypothesize that immune exclusion may occur with pooled colostrum; therefore, providing pooled colostrum may still be a good practice as long as it can be ensured that enough antibodies are absorbed into the blood stream to deal with pathogens calves may encounter because different dams may have antibodies against different strains of viruses and bacteria, yielding cross protection.

Report of a Delphi exercise to inform the design of a research programme on screening for thoracic aortic disease

Objectives

To inform the design of a clinical trial of a targeted screening programme for relatives of individuals affected by thoracic aortic disease, we performed a consensus exercise as to the acceptability of screening, the optimal sequence and choice of tests, long-term patient management, and choice of trial design.

Methods

Working with the Aortic Dissection Awareness UK & Ireland patient association, we performed a Delphi exercise with clinical experts, patients, and carers, consisting of three rounds of consultation followed by a final multi-stakeholder face-to-face workshop.

Results

Thirty-five experts and 84 members of the public took part in the surveys, with 164 patients and clinicians attending the final workshop. There was substantial agreement on the need for a targeted screening pathway that would employ a combined approach (imaging + genetic testing). The target population would include the first- and second-degree adult (> 15 years) relatives, with no upper age limit of affected patients. Disagreement persisted about the screening process, sequence, personnel, the imaging method to adopt, computed tomography (CT) scan vs magnetic resonance imaging (MRI), and the specifics of a potential trial, including willingness to undergo randomisation, and measures of effectiveness and acceptability.

Conclusion

A Delphi process, initiated by patients, identified areas of uncertainty with respect to behaviour, process, and the design of a targeted screening programme for thoracic aortic disease that requires further research prior to any future trial.

Cow and herd-level risk factors associated with mobility scores in pasture-based dairy cows

Lameness in dairy cows is an area of concern from an economic, environmental and animal welfare point of view. While the potential risk factors associated with suboptimal mobility in non-pasture-based systems are evident throughout the literature, the same information is less abundant for pasture-based systems specifically those coupled with seasonal calving, like those in Ireland. Therefore, the objective of this study was to determine the potential risk factors associated with specific mobility scores (0 = good, 1 = imperfect, 2 = impaired, and 3 = severely impaired mobility) for pasture-based dairy cows. Various cow and herd-level potential risk factors from Irish pasture-based systems were collected and analyzed for their association with suboptimal mobility, whereby a mobility score of 0 refers to cows with optimal mobility and a mobility score ≥ 1 refers to a cow with some form of suboptimal mobility. Combined cow and herd-level statistical models were used to determine the increased or decreased risk for mobility score 1, 2, and 3 (any form of suboptimal mobility) compared to the risk for mobility score 0 (optimal mobility), as the outcome variable and the various potential risk factors at both the cow and herd-level were included as predictor type variables. Cow-level variables included body condition score, milk yield, genetic predicted transmitting ability for 'lameness', somatic cell score, calving month and cow breed. Herd-level variables included various environmental and management practices on farm. These analyses have identified several cow-level potential risk factors (including low body condition score, high milk yield, elevated somatic cell count, stage of lactation, calving month, and certain breed types), as well as various herd-level potential risk factors (including the amount of time taken to complete the milking process, claw trimmer training, farm layout factors and foot bathing practices) which are associated with suboptimal mobility. The results of this study should be considered by farm advisors when advising and implementing a cow/herd health program for dairy cows in pasture-based systems.

100 Prevalence of Cognitive Impairment in Vascular Surgery Patients: Preliminary Results of A Systematic Review and Meta-Analysis

Introduction

Single-centre studies have shown a high prevalence of undiagnosed cognitive impairment in patients undergoing vascular surgery. The aim of this meta-analysis was to estimate the pooled prevalence of cognitive impairment in vascular surgery patients.

Methods

A systematic review and meta-analysis was performed of studies reporting cognitive impairment in vascular surgery patients (PROSPERO registration: CRD42019134684). Databases searched included: Medline, Embase, Emcare, CINAHL, PsychINFO and Scopus. Studies were excluded if they: did not use a validated cognitive assessment tool, included patients with asymptomatic or sub-threshold (for treatment) disease, or excluded patients with cognitive impairment. Quality of included studies was assessed using Newcastle-Ottawa scores (NOS), risk of bias was assessed using the ROBINS-E tool, and quality of evidence assessed using GRADE criteria. A pooled estimate of prevalence was calculated using the inverse-variance method separately for carotid artery disease (CAD), lower extremity arterial disease (LEAD), and studies including patients with multiple vascular surgery presentations. Data were pooled using random effects models and estimated prevalence presented with 95% confidence intervals (95%CI). Subgroup analyses were performed by cognitive assessment tool used.

Authors of 24 studies meeting inclusion criteria that did not report numbers of cognitively impaired patients were contacted to enable inclusion: responses are awaited.

Results

After de-duplication of search results, 7,169 records were screened and 11 studies (911 patients) included in the meta-analysis. Nine studies were deemed high quality (NOS ≥7) however 8 studies had a serious risk of bias. Only one study explicitly stated provision for recruiting patients without capacity. Six different tools were used to assess cognitive function (MoCA, MMSE, ACE-R, HDS-R, Mini-Cog and a global cognitive score). Two studies found an association of cognitive impairment with post-op delirium whilst one did not, and a further study showed an association with increased length of stay.

Pooled estimate of prevalence of cognitive impairment in CAD patients was 38% (95%CI 17%, 62%; 7 studies), and in “vascular surgery patients” was 61% (95%CI 47%, 74%, 3 studies). Only one study reported prevalence of cognitive impairment in LEAD patients alone of 19% (95%CI 14%, 24%). Quality of evidence was moderate to very low.

Conclusions

Cognitive impairment is highly prevalent in vascular surgery patients highlighting the need for close collaboration between vascular surgeons and geriatricians.

Development of a welfare assessment protocol for dairy calves from birth through to weaning

The aim of this study was to develop a welfare assessment protocol using different indicators, for pre-weaned dairy calves, that is feasible and time efficient. To this end, the protocol had to combine animal-based indicators (measurements on physiology, general appearance and behaviour) providing the basis for welfare assessment, with resource-based indicators (measurements on management and the environment) providing the basis for identifying risk factors. Indicators, both animal- and resource-based, were selected by a review of existing literature and a process of expert consultation. Following the formulation phase, the protocol was then applied on five Irish dairy farms to develop further for completeness and on-farm feasibility. After each on-farm application, the protocol was critically evaluated, and modifications were made accordingly. Upon completion of the on-farm application phase, a feasible, reliable and time-efficient protocol was produced.

Associating cow characteristics with mobility scores in pasture-based dairy cows

The quality of dairy cow mobility can have significant welfare, economic, and environmental consequences that have yet to be extensively quantified for pasture-based systems. The objective of this study was to characterize mobility quality by examining associations between specific mobility scores, claw disorders (both the type and severity), body condition score (BCS), and cow parity. Data were collected for 6,927 cows from 52 pasture-based dairy herds, including mobility score (0 = optimal mobility; 1, 2, or 3 = increasing severities of suboptimal mobility), claw disorder type and severity, BCS, and cow parity. Multinomial logistic regression was used for analysis. The outcome variable was mobility score, and the predictor variables were BCS, type and severity of claw disorders, and cow parity. Three models were run, each with 1 reference category (mobility score 0, 1, or 2). Each model also included claw disorders (overgrown claw, sole hemorrhage, white line disease, sole ulcer, and digital dermatitis), BCS, and cow parity as predictor variables. The presence of most types of claw disorders had odds ratios >1, indicating an increased likelihood of a cow having suboptimal mobility. Low BCS (BCS <3.00) was associated with an increased risk of a cow having suboptimal mobility, and relatively higher parity was also associated with an increased risk of suboptimal mobility. These results confirm an association between claw disorders, BCS, cow parity, and dairy cow mobility score. Therefore, mobility score should be routinely practiced to identify cows with slight deviations from the optimal mobility pattern and to take preventive measures to keep the problem from worsening.

Effect of exposure to Neospora caninum, Salmonella, and Leptospira interrogans serovar Hardjo on the economic performance of Irish dairy herds

The objective of the current study was to quantify the effects of exposure to Salmonella, Neospora caninum, and Leptospira interrogans serovar Hardjo (L. hardjo) on dairy farm profitability and to simulate the effect of vaccination for Salmonella and L. hardjo on dairy farm profitability. The production effects associated with exposure to each of these pathogens in study herds were defined under 3 categories: (1) milk production effects, (2) reproduction effects (including culling), and (3) mortality effects. The production effects associated with exposure to Salmonella, N. caninum, and L. hardjo were incorporated into the Moorepark Dairy Systems Model. In the analysis, herds negative for exposure to Salmonella, N. caninum, and L. hardjo were assumed baseline herds, with all results presented relative to this base. In simulations examining the effect of vaccination for Salmonella and L. hardjo on farm profitability, vaccinated herds (vaccination costs included) were considered as baseline herds and results were presented relative to this base. Total annual profits in unvaccinated herds were reduced by €77.31, €94.71, and €112.11 per cow at milk prices of €0.24, €0.29, and €0.34/L, respectively, as a result of exposure to Salmonella. In the current study, herds positive for exposure to Salmonella recorded a 316-kg reduction in milk yield, whereas no association was detected between exposure to N. caninum or L. hardjo and milk production. Exposure to both N. caninum and L. hardjo was associated with compromised reproductive performance. Herds positive for exposure to N. caninum and Salmonella had greater rates of adult cow mortality and calf mortality, respectively. Vaccination for both Salmonella and L. hardjo was associated with improved performance in study herds. Exposure to N. caninum resulted in a reduction in annual farm profits of €11.55, €12, and €12.44 per cow at each milk price, whereas exposure to L. hardjo resulted in a reduction in annual farm profits of €13.83, €13.78, and €13.72 per cow at each milk price. Herds that tested positive for exposure to Salmonella and L. hardjo were compared with herds vaccinated for the respective pathogens. Herds vaccinated for Salmonella generated €67.09, €84.48, and €101.89 per cow more profit at each milk price compared with herds positive for exposure. Similarly, herds vaccinated for L. hardjo generated €9.74, €9.69, and €9.63 per cow more profit compared with unvaccinated exposed herds. However, herds that tested negative for exposure to Salmonella and L. hardjo generated additional profits of €10.22 and €4.09 per cow, respectively, compared with vaccinated baseline herds.

A review of the official sampling of flocks of laying hens in the Salmonella National Control Programme in Great Britain

In line with European legislation and the UK National Control Programme for Salmonella, poultry farms are sampled to establish their Salmonella status. Regular samples are collected by the farmer (operator), with annual routine (official) samples being collected by the competent authority to verify achievement of the Salmonella programme reduction target. To confirm sampling was being carried out effectively, a questionnaire-based survey was conducted. The aim was to identify any complicating factors the samplers encountered and the decisions made in these circumstances. There was good compliance with the official sampling visits, with few delays reported. However, farm-specific clothing/separate boots for non-caged houses were rarely provided by the operator, whereas boot dips and hand washing facilities were usually available. The collection of dust was often a problem for official samplers, operator boot swabs were not always moistened before sampling and both sampler groups did not always follow the recommended method for the collection of faeces from belts and scrapers. Overall, there was a good application of the sampling protocol, although a few areas for improvement were identified.

Investigation of the migration of triclabendazole residues to milk products manufactured from bovine milk, and stability therein, following lactating cow treatment

Triclabendazole (TCB) is a flukicide used in the treatment of liver fluke in cattle; however, its use is currently prohibited in lactating dairy cows. In this study, following administration of 10% Fasinex (triclabendazole, Novartis Animal Health UK Ltd., Camberley, UK) the milk of 6 animals was used to manufacture dairy products, to ascertain if TCB residues in milk migrate into dairy products. The detection limit of the ultra-high-performance liquid chromatography-tandem mass spectrometry method used was 0.67 μg/kg. The highest concentrations of TCB residue measured, within the individual cow milk yield, was 1,529 ± 244 µg/kg (n=6), on d 2 posttreatment. Days 2 and 23 posttreatment represented high and low residue concentrations, respectively. At each of these 2 time points, the milk was pooled into 2 independent aliquots and refrigerated. Milk products, including cheese, butter, and skim milk powder were manufactured using pasteurized and unpasteurized milk from each aliquot. The results for high residue milks demonstrated that TCB residues concentrated in the cheese by a factor of 5 (5,372 vs. 918 µg/kg for cheese vs. milk) compared with the starting milk. Residue concentrations are the sum of TCB and its metabolites, expressed as keto-TCB. Residues were concentrated in the butter by a factor of 9 (9,177 vs. 1,082 μg/kg for butter vs. milk) compared with the starting milk. For milk, which was separated to skim milk and cream fractions, the residues were concentrated in the cream. Once skim milk powder was manufactured from the skim milk fraction, the residue in powder was concentrated 15-fold compared with the starting skim milk (7,252 vs. 423 µg/kg for powder vs. skim milk), despite the high temperature (185 °C) required during powder manufacture. For products manufactured from milk with low residue concentrations at d 23 posttreatment, TCB residues were detected in butter, cheese, and skim milk powder, even though there was no detectable residue in the milk used to manufacture these products. Triclabendazole residues were concentrated in some milk products (despite manufacturing treatments), exceeding residue levels in the starting milk and, depending on the storage conditions, may be relatively stable over time.

The first International Standard anti-Brucella melitensis Serum

The World Organisation for Animal Health (OIE) requested an International Standard anti-Brucella melitensis Serum (ISaBmS) to standardise diagnostic tests and reagents for sheep and goats. The agreed criteria were the highest dilution (in negative serum) of the standard which must give a positive result and the lowest dilution (in negative serum) which must simultaneously give a negative result. The two dilutions for each assay were, respectively: indirect enzyme-linked immunosorbent assay (iELISA) 1/64 and 1/750, competitive ELISA (cELISA) 1/8 and 1/300, fluorescent polarisation assay (FPA) 1/16 and 1/200, Rose Bengal test (RBT) 1/16 and 1/200. The OIE International Standard Serum (OIEISS) will remain the primary standard for the RBT; the ISaBmS is an additional standard. It was impossible to set criteria for the complement fixation test, therefore the OIEISS will remain the primary standard. The ISaBmS can be used to standardise iELISA, cELISA and FPA to diagnose sheep and goat brucellosis. This standard should facilitate harmonisation of tests used for brucellosis surveillance and international trade in these species.

The role of the CCR5 Delta32 polymorphism in abdominal aortic aneurysms

BACKGROUND

C-C chemokine receptor 5 (CCR5) is involved in the regulation of the inflammatory response. Abdominal aortic aneurysms (AAA) may arise as the result of a chronic inflammatory process which is influenced by genetic predisposition. The CCR5 gene is associated with a 32 base pair deletion (the Delta32 polymorphism). The aim of this study was to investigate the role of the CCR5 Delta32 polymorphism in the development of AAA.

METHODS

A case-control study was conducted including 285 patients with AAA and 273 control subjects. A blood sample was taken from each individual and DNA was extracted. CCR5 genotype was determined using the polymerase chain reaction (PCR). Flow cytometry was used to investigate the biological activity of the Delta32 polymorphism.

RESULTS

There was no significant difference between the AAA and the control group in relation to the Delta32 allele frequency (AAA group 10%, control group = 12%, P = 0.82, chi-squared analysis). Genotype analysis revealed no significant difference between the groups (AAA vs. controls, wild-type homozygotes = 82% vs. 77%, heterozygotes = 16% vs. 21%, vs. Delta32 homozygotes = 2% and 2%, respectively, P = 0.33, chi-squared analysis). The polymorphism was shown to be biologically active with the number of Delta32 alleles correlating with cell expression of ccr5 as detected with flow cytometry (P < or = 0.05).

CONCLUSION

This study demonstrates that the ccr5 Delta32 is a biologically active genetic polymorphism; however, there is no association between this polymorphism and AAA.

Survey of pigs' kidneys with lesions consistent with PMWS and PDNS and ochratoxicosis. Part 1: concentrations and prevalence of ochratoxin A

One thousand condemned pigs' kidneys were collected in February 2002 from two pig abattoirs in England to assess the possible contribution of ochratoxicosis to postweaning multisystemic wasting syndrome (PMWS) and porcine dermatitis and nephropathy syndrome (PDNS); 250 of the kidneys with macroscopic lesions consistent with nephrosis/nephritis (pale or white cortical lesions) were selected, and the concentration of ochratoxin A was measured in samples of renal cortex by high-performance liquid chromatography (HPLC). Low concentrations were detected in 230 (92 per cent) of the kidneys tested, and in 41 (16.4 per cent) of them the concentration was below the limit of quantification of 0.2 microg/kg. In 187 (74.8 per cent) of the kidneys, the concentration was more than 0.2 microg/kg, and the highest concentration detected was 2.3 microg/kg. The mean (sd) concentration was 0.31 (0.33) microg/kg. The identification of ochratoxin A was confirmed by mass spectrometry. The concentrations of ochratoxin A did not exceed the threshold assessed by the Food Standards Agency to be safe for human food.

Survey of pigs' kidneys with lesions consistent with PMWS and PDNS and ochratoxicosis. Part 2: pathological and histological findings

One thousand condemned pigs' kidneys were collected in February 2002 from two pig abattoirs in England to assess the lesions due to postweaning multisystemic wasting syndrome (pmws) and porcine dermatitis and nephropathy syndrome (pdns) and the possible contribution of ochratoxicosis; 174 of the kidneys were pale, 295 were swollen and 81 were abnormally firm with the gross appearance of fibrosis. The main macroscopic finding was the presence of multifocal pale cortical lesions, observed in 446 of the kidneys, and there were large cysts in 266 of them. Histopathological lesions of non-suppurative tubulointerstitial nephritis, with degeneration and fibrosis of renal tubules, were identified in 213 of 250 (85.2 per cent) of the kidneys examined. These lesions were consistent with those reported in cases of pmws and pdns. The tubular degeneration and fibrosis were also consistent with ochratoxicosis. A higher mean concentration of ochratoxin A was significantly (P=0.020) associated with the presence of multifocal pale cortical lesions consistent with ochratoxicosis, but a causal relationship was not confirmed because histochemistry was not used to detect ochratoxin in the lesions directly. There was no significant correlation between the microscopic lesions and the concentration of ochratoxin. The degenerative lesions may have been caused by previous exposure to ochratoxin that had subsequently been excreted, but the microscopic lesions also included non-suppurative interstitial nephritis, which was unlikely to have been caused by ochratoxicosis.

Endovascular treatment of ruptured and symptomatic abdominal aortic aneurysms

OBJECTIVE

To report the experience of endovascular repair (ER) in patients with ruptured and symptomatic abdominal aortic aneurysms (rAAA and sAAA), comparing results with a cohort of controls who underwent open repair (OR) of sAAA or rAAA.

DESIGN

A historically controlled cohort study.

MATERIALS

Retrospective data from 21 patients who underwent ER and prospective data from 23 patients who underwent OR.

METHODS

Results were compared using the Mann-Whitney U-test.

RESULTS

Eleven ER patients had sAAAs and 10 had rAAAs. Nine OR patients had rAAAs and 13 had sAAAs. Thirty-day mortality was 11% in patients with rAAA in the ER group, and 54% in the OR group (p=0.03). There were no post-operative deaths in the patients who had an sAAA in the ER group, and one death in the patients who had sAAA in the OR group. Results as expressed as mean ER value versus mean OR value and p-value. ER was associated with significant reductions in the length of operation (2.6 versus 3.1h, p=0.03), blood transfusion requirements (0.86 versus 10.7 units p<0.01), time in critical care (1.5 versus 6.1 days, p=0.02), and total hospital stay (8.5 versus 17.5 days, p=0.01) compared with OR. There was no difference in time from admission to arrival in theatre between the two groups (3.4 versus 5.0h, p=0.35).

CONCLUSIONS

In patients with rAAA and sAAA that are suitable for stenting, ER has reduced mortality compared with open repair. Assessment for ER does not cause a pre-operative delay, operating time is reduced, blood transfusion requirements are reduced and there is a faster recovery.

Endotension--a late complication successfully treated by open repair

Endotension is a late complication following endovascular treatment of abdominal aortic aneurysm (AAA). A 83-year-old male had a successful endovascular repair of a 5.6 cm diameter AAA. During the follow-up period it was marked that the aneurysm continued to increase in size, became 6.6 cm maximal diameter and pulsatile with no evidence of endoleak. On laparotomy no endoleak was identified and the graft was left in situ. Postoperatively and on follow-up the patient remains asymptomatic while the aneurysm continued to appear shrunk.

Factors affecting the serological response of dogs and cats to rabies vaccination

After being vaccinated against rabies some cats and dogs fail to show an antibody titre adequate to meet the requirements of the UK Pet Travel Scheme. To investigate this problem, the data derived from 16,073 serum samples submitted to the Veterinary Laboratories Agency for serological testing between 1999 and 2002, 1002 samples submitted to BioBest during March and April 2001, and 1264 samples associated with one make of vaccine submitted to BioBest between June 2001 and January 2003, were analysed. The probability of antibody titre failing to reach at least 0.5 iu/ml was analysed by logistic regression as a function of the choice of vaccine, the interval between vaccination and sampling, the sex and age of the animal, and its country of origin. In dogs, all these factors, except sex, had highly significant (P < 0.001) effects on the test failure rate, and in cats all the factors had a significant effect (P < 0.05).

Duplicated inferior vena cava and crossed renal ectopia with abdominal aortic aneurysm: preoperative anatomic studies facilitate surgery

Abdominal aortic aneurysm in association with duplication of the inferior vena cava and crossed renal ectopia is described for the first time. Preoperative imaging with computer-aided tomography provided good visualization of the local anatomy, allowing the surgical approach to be adapted for the best access to the surgical site. A retroperitoneal approach was successfully used for repair of the abdominal aortic aneurysm.

Corrective effects of interleukin-12 on age-related deficiencies in IFN-gamma production and IL-12Rbeta2 expression in virus-specific CD8+ T cells

Interleukin-12 receptor beta2 (IL-12Rbeta2) has been shown to be selectively expressed on Th1 T cell subsets, and we have previously shown that influenza-specific CD8+ cytotoxic T lymphocyte (CTL) deficiency in old mice was associated with deficient Th1 (interferon-gamma [IFN-gamma]) cytokine production. This study tested whether IL-12Rbeta2 expression was also deficient in CD8+ CTL from old mice and the effect of IL-12 treatment on these responses. Splenic lymphocytes from influenza-primed old and young BALB/c mice were stimulated with influenza virus in vitro with and without IL-12 and then enriched for CD8+ T cells. IFN-gamma was significantly reduced, whereas IL-4 and IL-12p40 (an antagonist of IL-12 function) were evaluated in old when compared with young mice. This was true for secreted protein measured by ELISA and for mRNA levels quantitated by RT-PCR. IL-12Rbeta2 mRNA expression in CD8+ CTL was also significantly reduced in old mice. IL-12 treatment in vitro caused significant upregulation of IFN-gamma and IL-12Rbeta2 and downregulation of IL-4 in CD8+ T cells from old mice and young mice. The present demonstration of an age-related downregulation in IL-12Rbeta2 expression and our previous data showing reduced IFN-gamma and elevated IL-4 production provide strong evidence that CD8+ CTL deficiency in aging results from a Th1/Th2 cytokine production switch. Agents that increase IL-12Rbeta2 expression and redirect Th2 to Thl immune responses are likely to enhance CD8+ CTL-mediated control of viral infections in aging.

Role for transforming growth factor-beta1 in alport renal disease progression

BACKGROUND

Alport syndrome results from mutations in either the alpha3(IV), alpha4(IV), or alpha5(IV) collagen genes. The disease is characterized by a progressive glomerulonephritis usually associated with a high-frequency sensorineural hearing loss. A mouse model for an autosomal form of Alport syndrome [collagen alpha3(IV) knockout] was produced and characterized. In this study, the model was exploited to demonstrate a potential role for transforming growth factor-beta1 (TGF-beta1) in Alport renal disease pathogenesis.

METHODS

Kidneys from normal and Alport mice, taken at different stages during the course of renal disease progression, were analyzed by Northern blot, in situ hybridization, and immunohistology for expression of TGF-beta1 and components of the extracellular matrix. Normal and Alport human kidney was examined for TGF-beta1 expression using RNase protection.

RESULTS

The mRNAs encoding TGF-beta1 (in both mouse and human), entactin, fibronectin, and the collagen alpha1(IV) and alpha2(IV) chains were significantly induced in total kidney as a function of Alport renal disease progression. The induction of these specific mRNAs was observed in the glomerular podocytes of animals with advanced disease. Type IV collagen, laminin-1, and fibronectin were markedly elevated in the tubulointerstitium at 10 weeks, but not at 6 weeks, suggesting that elevated expression of specific mRNAs on Northern blots reflects events associated with tubulointerstitial fibrosis.

CONCLUSIONS

The concomitant accumulation of mRNAs encoding TGF-beta1 and extracellular matrix components in the podocytes of diseased kidneys may reflect key events in Alport renal disease progression. These data suggest a role for TGF-beta1 in both glomerular and tubulointerstitial damage associated with Alport syndrome.

American Academy of Pediatrics. Committee on Practice and Ambulatory Medicine and Committee on Medical Liability. Pediatric physician profiling

Employers, insurers, and other purchasers of health care services collect data to profile the practice habits of pediatricians and other physicians. This policy statement delineates a series of recommendations that should be adopted by health care purchasers to guide the development and implementation of physician profiling systems.

Activation of membrane-associated procaspase-3 is regulated by Bcl-2

The mechanism by which membrane-bound Bcl-2 inhibits the activation of cytoplasmic procaspases is unknown. Here we characterize an intracellular, membrane-associated form of procaspase-3 whose activation is controlled by Bcl-2. Heavy membranes isolated from control cells contained a spontaneously activatable caspase-3 zymogen. In contrast, in Bcl-2 overexpressing cells, although the caspase-3 zymogen was still associated with heavy membranes, its spontaneous activation was blocked. However, Bcl-2 expression had little effect on the levels of cytoplasmic caspase activity in unstimulated cells. Furthermore, the membrane-associated caspase-3 differed from cytosolic caspase-3 in its responsiveness to activation by exogenous cytochrome c. Our results demonstrate that intracellular membranes can generate active caspase-3 by a Bcl-2-inhibitable mechanism, and that control of caspase activation in membranes is distinct from that observed in the cytoplasm. These data suggest that Bcl-2 may control cytoplasmic events in part by blocking the activation of membrane-associated procaspases.

Collagen COL4A3 knockout: a mouse model for autosomal Alport syndrome

A mouse model for the autosomal form of Alport syndrome was produced. These mice develop a progressive glomerulonephritis with microhematuria and proteinuria, consistent with the human disease. End-stage renal disease develops at approximately 14 weeks of age. TEM analysis of the glomerular basement membranes (GBM) during development of renal pathology revealed focal multilaminated thickening and thinning beginning in the external capillary loops at 4 weeks and spreading throughout the GBM by 8 weeks. By 14 weeks, half of the glomeruli were fibrotic with collapsed capillaries. Immunofluorescence analysis of the GBM showed the absence of type IV collagen alpha-3, alpha-4, and alpha-5 chains and a persistence of alpha-1 and alpha-2 chains (these chains normally localize to the mesangial matrix). Northern blot analysis using probes specific for the collagen chains illustrate the absence of COL4A3 in the knockout, whereas mRNAs for the remaining chains are unchanged. An accumulation of fibronectin, heparan sulfate proteoglycan, laminin-1, and entactin was observed in the GBM of the affected animals. The temporal and spatial pattern of accumulation was consistent with that for thickening of the GBM as observed by TEM. Thus, expression of these basement membrane-associated proteins may be involved in the progression of Alport renal disease pathogenesis. The levels of mRNAs encoding the basement membrane-associated proteins at 7 weeks were unchanged.

The changing workload of a surgical unit with a vascular interest

OBJECTIVES

To examine the changing relationship between general and vascular surgical workload on a vascular "firm", over a 6-year period.

DESIGN

Retrospective review.

SETTING

Leicester Royal Infirmary and Professorial Surgical Unit, U.K. 1987-1992.

METHOD

Analysis of audit of all surgical admissions. Relation of vascular surgery to general surgery.

RESULTS

There has been a slight decrease (5%) in the number of general surgical elective admissions. Overall, the number of general surgical admissions, both elective and emergency, show a slight increase of about 3%. In contrast the number of vascular admissions increased by 42%. Of the general surgical procedures carried out 75.9% were either minor or intermediate, whereas 92.5% of vascular procedures were coded as major or higher. There has been a three times increase in the number of carotid endarterectomies, a similar increase in the number of the femorodistal bypass grafts and a halving of the number of major amputations. There has also been a five times increase in the number of angioplasties carried out.

CONCLUSIONS

Our figures show the progressive, rapid increase in vascular surgical workload, compared to general surgery, and the need for the continued expansion of vascular surgery as a speciality.

Associations between viral infections and respiratory disease in artificially reared calves

Market-purchased, week-old, dairy bred calves entering a commercial calf-rearing unit were blood sampled at six-week intervals until three months old. Viral infections were monitored by ELISA for antibodies to bovine herpesvirus 1, bovine respiratory syncytial virus, parainfluenzavirus-3, bovine adenovirus subgroup 1 and bovine viral diarrhoea virus (BVDV). The immunoperoxidase test was used to detect BVDV in serum. The total immunoglobulin concentration in the initial blood sample was measured by the zinc sulphate turbidity test. The relationship between clinical respiratory disease, viral seroconversion and the initial concentration of serum immunoglobulin was investigated by the use of the relative risk statistic, Fisher's exact test, chi 2 techniques and the correlation coefficient. Treatment rates for respiratory disease of 45 per cent were observed during the first period of the study and 19 per cent during the second period. During the first period there was a significant positive association between clinical respiratory disease and seroconversion for all the viruses except parainfluenzavirus-3 and BVDV but in the second period there was no such relationship. Similarly, in the first period, but not in the second, there was a significant negative association between clinical respiratory disease and both antiviral immunoglobulin as measured by ELISA and total immunoglobulin as measured by the zinc sulphate turbidity test. Two of the 536 calves that survived to three months of age were found to be persistently infected with BVDV.