Treatment Preferences of Patients With Benign Prostatic Hyperplasia Before and After Using a Web-based Decision Aid.

OBJECTIVE: To evaluate treatment preferences of patients with lower urinary tract symptoms suggestive of benign prostatic hyperplasia (LUTS/BPH) before and after using a web-based decision aid (DA). PATIENTS AND METHODS: Between July 2016 and January 2017 patients were invited to use a web-based LUTS/BPH DA. Treatment preferences (for lifestyle advices, medication or surgery) before and after DA use and responses on values clarification exercises were extracted from the DA. RESULTS: In total, 126 patients were included in the analysis. Thirty-four percent (43/126) had not received any previous treatment and were eligible for (continuation of) lifestyle advices or to start medication, as initial treatment. The other 66% (83/126) did use medication and were eligible, either for continuing medication or to undergo surgery. Before being exposed to the DA, 67 patients (53%) were undecided and 59 patients (47%) indicated an initial treatment preference. Half of the patients who were initially undecided were able to indicate a preference after DA use (34/67, 51%). Of those with an initial preference, 80% (47/59) confirmed their initial preference after DA use. Five out of 7 values clarification exercises used in the DA were discriminative between final treatment preferences. In 79%, the treatment preferred after DA use matched the received treatment. Overall, healthcare providers were positive about DA feasibility. CONCLUSION: Our findings suggest that a LUTS/BPH DA may help patients to confirm their initial treatment preference and support them in forming a treatment preference if they did not have an initial preference.

Effectiveness of a web-based treatment decision aid for men with lower urinary tract symptoms due to benign prostatic hyperplasia.

OBJECTIVES: To evaluate the effectiveness of a web-based decision aid (DA), with values clarification exercises compared with usual care, for men with lower urinary tract symptoms due to benign prostatic hyperplasia (LUTS/BPH). PATIENTS AND METHODS: Between July 2016 and January 2017, all new patients with LUTS/BPH who consulted the urologist were invited to use the DA and participate in this prospective questionnaire study. Patients who consulted the urologist between December 2015 and February 2016 served as controls. The DA was designed to support patients in making a well-informed treatment decision, corresponding with their personal preferences and values. Well-informed decision was measured by using a knowledge questionnaire. Value congruent decision was measured by the correspondence between responses on nine value statements and chosen treatment. The primary outcome, decision quality, was defined as the combination of well-informed decision and value congruent decision. Secondary outcomes were decisional conflict, involvement and received role in shared decision-making, decisional regret, and treatment choice. RESULTS: A total of 109 DA-users and 108 controls were included. DA-users were younger (68.4 vs 71.5 years; P = 0.003) and their education level was higher (P = 0.047) compared with the controls. Patients who used the DA made a well-informed and value congruent decision more often than the control group (43% vs 21%; P = 0.028). DA-users had less decisional conflict (score 33.2 vs 46.6; P = 0.003), experienced a less passive role in decision-making (22% vs 41%; P = 0.038), and reported less process regret (score 2.4 vs 2.8; P = 0.034). Furthermore, DA-users who had not used prior medication chose lifestyle advices more often than the control group (43% vs 11%; P = 0.002). Outcomes were adjusted for significantly different baseline characteristics. CONCLUSION: The LUTS/BPH DA seems to improve the decision quality by supporting patients in making more well-informed and value congruent treatment decisions. Therefore, further implementation of this DA into routine care is suggested.

Is on-demand sacral neuromodulation in patients with OAB syndrome a feasible therapy regime?

INTRODUCTION: Sacral neuromodulation (SNM) of the lower urinary tract has proven to be safe and effective in patients with complaints of OAB syndrome who are not responding to conservative therapy. After 5 years of treatment the implanted system is still effective in 56-71% of patients. The loss of effect could be caused by adaptation of the nerve system to prolonged stimulation of the sacral nerves. MATERIALS AND METHODS: We set up a pilot intervention study. After a run-in period of 2 weeks patients were randomized into two groups: one group with on-demand neuromodulation (intervention group) and one group with continuous neuromodulation (control group). Patients in the intervention group were instructed to switch their INS off by default and to switch it on again when they felt recurrent symptoms, patients in the control group were asked to use their system as normally. RESULTS: After 2 weeks 10 out of 16 subjects reported a comparable symptom score during on-demand use of their neuromodulation system. Patients appreciated the comfort of being self-determent in the need for therapy. CONCLUSIONS: Possible benefits for patients could be: more autonomy, longer battery life of the implanted INS, decreasing the chance of adaptation by the nervous system.

Sensor networks in the low lands.

This paper provides an overview of scientific and industrial developments of the last decade in the area of sensor networks in The Netherlands (Low Lands). The goal is to highlight areas in which the Netherlands has made most contributions and is currently a dominant player in the field of sensor networks. On the one hand, motivations, addressed topics, and initiatives taken in this period are presented, while on the other hand, special emphasis is given to identifying current and future trends and formulating a vision for the coming five to ten years. The presented overview and trend analysis clearly show that Dutch research and industrial efforts, in line with recent worldwide developments in the field of sensor technology, present a clear shift from sensor node platforms, operating systems, communication, networking, and data management aspects of the sensor networks to reasoning/cognition, control, and actuation.

A mutation in NFkappaB interacting protein 1 causes cardiomyopathy and woolly haircoat syndrome of Poll Hereford cattle.

Cardiomyopathy and woolly haircoat syndrome (CWH) of Poll Hereford cattle is a lethal, autosomal recessive disorder. Cardiac and haircoat changes are congenital, neonatal ocular keratitis develops in some cases and death usually occurs within the first 12 weeks of life. We undertook a homozygosity mapping approach to identify the chromosomal location of the causative gene. Seven candidate genes were examined for homozygosity in affected animals: desmoplakin and junction plakoglobin (both previously implicated in human cardiocutaneous syndromes), desmocollin 2, desmoglein 2, plakophilin 2, nuclear factor kappa B (NFKB1) and NFkappaB interacting protein 1 (PPP1R13L, also known as NKIP1). Homozygosity in 13 affected animals was observed at the PPP1R13L locus, located on bovine chromosome 18. Subsequent sequence analysis revealed a 7-bp duplication (c.956_962dup7) in exon 6 of this 13-exon gene. This frameshift variant is predicted to result in the substitution of three amino acids and the introduction of a premature stop codon at position 325 of the protein product (p.Ser322GlnfsX4). PPP1R13L interacts with NFkappaB, a family of structurally related transcription factors that regulate genes controlling inflammation, immune responses and cell proliferation and survival. CWH represents a large-animal model for cardiocutaneous disorders caused by a mutation in the PPP1R13L gene. The identification of this bovine mutation also indicates that PPP1R13L and other genes affecting NFkappaB activity may be candidate genes in the study of human cardiovascular disease.

Sacral nerve stimulation for neuromodulation of the lower urinary tract.

Patients with symptoms of overactive bladder syndrome or non-obstructive urinary retention, refractory to conservative therapy, can nowadays be treated minimally invasively with sacral nerve stimulation (SNS). The use of electric currents to treat urological pathology has a long history but SNS therapy only received FDA approval in 1997. The mechanisms of action are still not known so there are different theories explaining the modulation effect. Recent studies have shown a central modulation effect. Predictive factors which can help to identify the perfect candidates are not known. Over the years the technique of SNS has become less invasive and because of two stage implantation test results have proven to be more reliable. The clinical results for this therapy have proven to be safe and effective and with the technical improvements over the years the re-operation and complication rates have decreased significantly. The clinical results have led to expanding indications because of positive effects in other symptoms. In the field of urology this has resulted in the use of SNS therapy for interstitial cystitis, neurogenic lower urinary dysfunction, and pediatric voiding dysfunction. In the field of gastro-intestinal pathology, SNS therapy is used to treat faecal incontinence and constipation.

Cognitive-behavioural training interventions for assisting foster carers in the management of difficult behaviour.

BACKGROUND: The provision of training for foster carers is now seen as an important factor contributing to the successful outcome of foster care placements. Since the late 1960s, foster carer training programs have proliferated, and few of the many published and unpublished training curricula have been systematically assessed and evaluated. The advent of cognitive-behavioural therapy (CBT) and the research evidence demonstrating its effectiveness as a psychotherapeutic treatment of choice, has prompted many working in the social care field to devise CBT-based training programmes. CBT approaches to foster care training derive from a 'skill-based' training format that also seeks to identify and correct problematic thinking patterns that are associated with dysfunctional behaviour by changing and/or challenging maladaptive thoughts and beliefs. OBJECTIVES: To assess the effectiveness of cognitive-behavioural training interventions in improving a) looked-after children's behavioural/relationship problems, b) foster carers' psychological well-being and functioning, c) foster family functioning, d) foster agency outcomes. SEARCH STRATEGY: We searched databases including: CENTRAL (Cochrane Library Issue 3, 2006), MEDLINE (January 1966 to September 2006), EMBASE (January 1980 to April 2004), CINAHL (January 1982 to April 2004), PsycINFO (January 1872 to April 2004), ASSIA (January 1987 to April 2004), LILACS (up to April 2004), ERIC (January 1965 to April 2004), Sociological Abstracts (January 1963 to April 2004), and the National Research Register 2004 (Issue 3). We contacted experts in the field concerning current research. SELECTION CRITERIA: All studies in which participants were foster parents/carers, and who were allocated by random or quasi-random methods to a CBT-based training intervention (in a group and/or one-to-one settings) versus a no-treatment or wait-list control, were selected. DATA COLLECTION AND ANALYSIS: Data from the six eligible trials (total n = 463 ) were extracted and entered into RevMan. Results were synthesised and presented in both graphical (forest plots) and narrative form (where insufficient data were provided for effect size computations). MAIN RESULTS: Training interventions evaluated to date appear to have very little effect on outcomes relating to looked-after children, assessed in relation to psychological functioning, extent of behavioural problems and interpersonal functioning. Results relating to foster carer(s) outcomes also show no evidence of effectiveness in measures of behavioural management skills, attitudes and psychological functioning. Analysis pertaining to fostering agency outcomes did not show any significant results. AUTHORS' CONCLUSIONS: There is currently little evidence about the efficacy of CBT-based training intervention for foster carers. The need for further research in this area is highlighted.

Medium-term experience of sacral neuromodulation by tined lead implantation.

OBJECTIVE: To describe patient selection for sacral neuromodulation, also known as Interstim therapy, and the results of tined-lead implantation in the medium term. PATIENTS AND METHODS: In all, 49 patients, 39 with refractory overactive bladder symptoms and 10 with urinary retention, were implanted with the tined lead under local anaesthesia. The mean (sd) test period was 12.4 (5.8) days. Patients were implanted when they had a > or = 50% improvement in voiding diary variables during the test period. The mean follow-up for implanted patients was 15.5 (7.9) months. Changes in voiding variables were compared using a t-test. RESULTS: Ten patients had a one-stage and 39 a two-stage implant; of the latter group, 31 (80%) had a positive response and eight (21%) did not. In all, 31 patients were included in the follow-up. At the last follow-up, 28 (90%) patients had a >50% improvement in diary variables and three (10%) did not. In 21 patients with urgency symptoms the mean (sd) number of voids decreased from 11.7 (8.9)/day at baseline to 7.3 (3.4)/day (P = 0.1); the voided volume increased from 160.2 (70.7) mL to 231.1 (119.5) mL (P = 0.001); and the number of leakages decreased from 9.5 (8.7) to 3.3 (2.2)/day (P = 0.17). In the 10 patients with retention, the number of catheterizations decreased from 5.44 (1.6)/day with a volume of 297.6 (76.8) mL, to 1.2 (1.7)/day and 111.6 (158.1) mL; the mean number of voids increased from 3.7 (3.8)/day with a volume of 123.3 (141.7) mL, to 4.2 (2.4)/day and 248.3 (146.0)mL. There were no significant differences in the variables in the patients with retention. Seven patients had an adverse event. There was one incomplete electrode migration that was treated conservatively. CONCLUSION: This new minimally invasive approach gives positive results in the medium term. Two-stage testing with the tined lead seems more reliable than the classic percutaneous nerve evaluation. The lead anchoring method seems sufficient for fixing the electrode in the medium term.

Cognitive-behavioural training interventions for assisting foster carers in the management of difficult behaviour.

BACKGROUND: The provision of training for foster carers is now seen as an important factor contributing to the successful outcome of foster care placements. It is believed to be associated with enhancing caring attitudes and skills, reducing behaviour problems in foster children, improving relationships between foster carers and child welfare agencies, and decreasing foster carer attrition. Since the late 1960s, foster carer training programs have proliferated, and few of the many published and unpublished training curricula have been systematically assessed and evaluated. The advent of cognitive-behavioural therapy (CBT) and the research evidence demonstrating its effectiveness as a psychotherapeutic treatment of choice, has prompted many working in the social care field to devise CBT-based training programmes. CBT approaches to foster care training derive from a 'skill-based' training format that also seeks to identify and correct problematic thinking patterns that are associated with dysfunctional behaviour by changing and/or challenging maladaptive thoughts and beliefs. OBJECTIVES: To assess the effectiveness of cognitive-behavioural training interventions in improving a) looked-after children's behavioural/relationship problems, b) foster carers' psychological well-being and functioning, c) foster family functioning, d) foster agency outcomes. SEARCH STRATEGY: We searched databases including: CENTRAL (Cochrane Library Issue 2, 2004), MEDLINE (January 1966 to April 2004), EMBASE (January 1980 to April 2004), CINAHL (January 1982 to April 2004), PsycINFO (January 1872 to April 2004), ASSIA (January 1987 to April 2004), LILACS (up to April 2004), ERIC (January 1965 to April 2004), Sociological Abstracts (January 1963 to April 2004), and the National Research Register 2004 (Issue 1). We contacted experts in the field concerning current research. SELECTION CRITERIA: All studies in which participants were foster parents/carers, and who were allocated by random or quasi-random methods to a CBT-based training intervention (in a group and/or one-to-one settings) versus a no-treatment or wait-list control, were selected. DATA COLLECTION AND ANALYSIS: Results from the five eligible trials (total n = 443 ) are reported narratively. Due to the diversity of measures employed, no meta-analysis was performed. MAIN RESULTS: Training interventions evaluated to date appear to have very little effect on outcomes relating to looked-after children, assessed in relation to psychological functioning, extent of behavioural problems and interpersonal functioning. Results relating to foster carer(s) outcomes indicate some improvements in measures of behavioural management skills, attitudes and psychological functioning. Analysis pertaining to fostering agency outcomes did not show any significant results. AUTHORS' CONCLUSIONS: Inconclusive evidence exists about the efficacy of CBT-based training intervention for foster carers. The need for further research in this area is highlighted.

Genotyping cattle for inherited congenital myoclonus and maple syrup urine disease.

OBJECTIVE: To develop a routine procedure for establishing the inherited congenital myoclonus (ICM) genotype of cattle and to obtain an estimate of the prevalence of heterozygotes for ICM and maple syrup urine disease (MSUD) in Australian Poll Herefords. DESIGN: A mismatch amplification procedure was developed to genotype for ICM. The ICM and MSUD genotypes of subjects from a 'neuraxial oedema' experimental breeding herd were investigated. Tail hair roots were used as a source of target DNA to determine the ICM and MSUD genotypes of 455 Poll Hereford bulls. RESULTS: An Acc I mismatch procedure was found to be suitable to genotype cattle for the ICM alleles using tail hair roots as the source of DNA. Based on the prevalence of heterozygotes among saleyard and sale bulls in the early 1990s, and contemporary slaughter bulls, the frequencies of the alleles responsible for ICM and MSUD were estimated to be between 0.01 and 0.02. CONCLUSION: This survey demonstrates that the mutations responsible for ICM and MSUD are present in the Australian Poll Hereford population. PCR tests could be used to advantage in differential diagnosis of neurological disease in newly born calves and in selection of Poll Hereford seed stock.

Genotyping Brahman cattle for generalised glycogenosis.

OBJECTIVE: To develop procedures for genotyping Brahman cattle for loss-of-function alleles within the acidic alpha-glucosidase gene and to assess the risk of generalised glycogenosis in Australian Brahman cattle. DESIGN: PCR assays for three loss-of-function alleles were designed to exploit internal restriction sites within acidic alpha-glucosidase amplicons that are independent of allelic variants at the mutant sites. RESULTS: Genotyping 8529 clinically normal Brahmans between August 1996 and August 2001 revealed 16.4% were heterozygous for the more common of the two mutations (1057deltaTA, often referred to as the 'E7' mutation) that cause generalised glycogenosis in this breed. The less common 1783T mutation (often referred to as the 'E13' mutation) was restricted to descendants of one imported bull, and was not detected in 600 randomly selected Brahmans. Prior to definition of these two disease-causing mutations, 640 (18%), and 14 (0.4%), of 3559 clinically normal Brahmans analysed between January 1994 and December 1996, were heterozygous, and homozygous, respectively, for a silent polymorphism (2223G-->A) that is associated with generalised glycogenosis. In addition to the 1057deltaTA and 1783T mutations, approximately 15% of Brahmans were found to be heterozygous for a single base substitution in exon 9 (1351T, commonly referred to as the 'E9' mutation) that significantly reduces acidic alpha-glucosidase activity, but has not been associated with clinical disease. These three loss-of-function alleles were found in Brahmans imported, or selected for import, from the USA. CONCLUSION: The PCR procedures reported here represent a significant improvement in reliability and accuracy over previous published methods. Utilisation of these PCR/restriction enzyme based assays will facilitate precise selection against the 1057deltaTA and 1783T alleles, and consequently reduce the incidence of generalised glycogenosis in registered and commercial Brahman herds.

A nonsense mutation in the alpha1 subunit of the inhibitory glycine receptor associated with bovine myoclonus.

Inherited congenital myoclonus of Poll Hereford calves is an autosomal recessive disease characterized by hyperesthesia and myoclonic jerks of the skeletal musculature that occur both spontaneously and in response to sensory stimuli. Binding studies have previously shown that myoclonus is associated with specific loss of [(3)H]strychnine-binding sites from spinal cord and brain stem in affected calves. In order to identify the mutation responsible for myoclonus, we examined the candidate genes, glycine receptor alpha1 (Glra1) and beta (Glrb) subunits, in affected and normal cattle. A nonsense mutation was found at amino acid 24, located in exon 2 of the Glra1 gene in both cDNA and genomic sequences from affected but not control animals. Immunohistochemistry, with a monoclonal antibody to alpha and beta subunits of the glycine receptor, revealed a loss of cell surface immunoreactivity in myoclonic animals, suggesting a failure in the assembly of the receptor that could explain the characteristic phenotype of the disease.

Genotyping shorthorn cattle for generalised glycogenosis.

OBJECTIVE: To develop a procedure for routine genotyping of Shorthorn cattle for the generalised glycogenosis allele in exon 18 of the acidic alpha-glucosidase gene. PROCEDURE: Allele-specific amplification and double mismatch amplification procedures for the discrimination of the exon 18 alleles were evaluated using leucocytes and hair roots as sources of target DNA. RESULTS: Allele-specific amplification was effective for genotyping Shorthorn cattle at the 2454 site when purified DNA was used as target for the polymerase chain reaction. However, when the target DNA was derived from hair roots, differences in the relative yield of wild-type and mutant amplicons were observed. The double mismatch amplification procedure was effective in genotyping all subjects, independent of the source of DNA. The unique cleavage sites for Drd I and PshA I within exon 18 are present and absent respectively in the wildtype amplicon, and are lost and acquired, respectively, in the mutant amplicon. In addition, the Drd I and PshA I mismatching cleavage sites incorporated into the primers serve as internal controls for Drd I and PshA I cleavage. CONCLUSION: The double Drd I/PshA I mismatch amplification procedure using hair root samples as the source of DNA is a robust method for genotyping Shorthorns for generalised glycogenosis.

The bovine alpha-glucosidase gene: coding region, genomic structure, and mutations that cause bovine generalized glycogenosis.

We report here cDNA and genomic sequence of the bovine acidic alpha-glucosidase gene, from the initiation codon to the most 3' polyadenylation signal. The 2814-bp coding sequence predicts a 937-amino acid protein, which is highly conserved compared with the human alpha-glucosidase gene (86% and 83% identity respectively). The intron/exon boundaries are also conserved between the two species. Two mutations have been identified in Brahmans, and one in Shorthorns, that lead to generalized glycogenosis. All three mutations result in premature termination of translation. Evidence is also presented for a missense mutation segregating with the Brahman population, which is responsible for a 70-80% reduction in alpha-glucosidase activity.

Definition of the mutation responsible for maple syrup urine disease in Poll Shorthorns and genotyping Poll Shorthorns and Poll Herefords for maple syrup urine disease alleles.

The organisation of the E1alpha subunit of bovine branched-chain alpha-keto acid dehydrogenase gene was established. c DNA was cloned from Poll Shorthorn x Poll Hereford calves affected with Maple Syrup Urine Disease to identify the mutation responsible for the disease in Poll Shorthorns. Clones containing the c DNA sequences inherited from the Poll Shorthorn sire of the affected calves were identified. Paternal clones were sequenced and a cytidine to thymidine transition was found at nucleotide 1380. The mutation is predicted to substitute leucine in place of a highly conserved proline at codon 372. A polymerase chain reaction procedure was developed for detection of the 1380C-->T mutation in genomic DNA. Three Poll Shorthorn parents of affected calves and three affected Poll Shorthorn x Poll Hereford calves were heterozygous and an affected Poll Shorthorn calf was homozygous for this mutation. An improved polymerase chain reaction procedure was also devised to genotype Poll Herefords for the 248C-->T mutation. The procedures will facilitate disease prevention programs and assist in differential diagnosis of conditions in new-born calves that present with a rapid onset of progressive neurological disease and are characterised histologically by 'status spongiosus'. Maple Syrup Urine Disease (MSUD) is an autosomal recessive defect reported in humans (Danner and Elsas 1989), and in Poll Hereford (PH) and Poll Shorthorn (PS) calves (Harper et al 1986, Healy et al 1992). The clinical, biochemical and pathological manifestations of the disease are identical in the two breeds of cattle, and are characterised by the rapid onset of progressive neurological disease, leading to death within a few days of birth. The disease is caused by a deficiency of activity of the mitochondrial enzyme branched-chain alpha-keto acid dehydrogenase (BCKADH). This deficiency leads to elevated concentrations, in blood and tissues, of branched chain alpha-keto acids and their precursors, the branched chain amino acids, valine, leucine and isoleucine. BCKADH consists of four subunits E1alpha, E1beta, E2 and E3 that are encoded by separate genes, and MSUD may result from deficiency of any of the subunits. In PH s, the disease in caused by premature termination of translation, of the E1alpha subunit, that is induced by a cytidine to thymidine transition exon 2 (248C-->T), that converts the glutamine codon -6 to a stop codon (Q-6ST; Zhang et al 1990). We have shown that MSUD -affected PSxPH calves are heterozygous at the PH locus, illustrating molecular heterogeneity exists for bovine MSUD (Healy and Dennis 1994a). The fact that these crossbred calves are affected, indicates the PS, like the PH mutation, resides in the E1alpha subunit.

Hepatocyte gene therapy in a large animal: a neonatal bovine model of citrullinemia.

The development of gene-replacement therapy for inborn errors of metabolism has been hindered by the limited number of suitable large-animal models of these diseases and by inadequate methods of assessing the efficacy of treatment. Such methods should provide sensitive detection of expression in vivo and should be unaffected by concurrent pharmacologic and dietary regimens. We present the results of studies in a neonatal bovine model of citrullinemia, an inborn error of urea-cycle metabolism characterized by deficiency of argininosuccinate synthetase and consequent life-threatening hyperammonemia. Measurements of the flux of nitrogen from orally administered 15NH4 to [15N]urea were used to determine urea-cycle activity in vivo. In control animals, these isotopic measurements proved to be unaffected by pharmacologic treatments. Systemic administration of a first-generation E1-deleted adenoviral vector expressing human argininosuccinate synthetase resulted in transduction of hepatocytes and partial correction of the enzyme defect. The isotopic method showed significant restoration of urea synthesis. Moreover, the calves showed clinical improvement and normalization of plasma glutamine levels after treatment. The results show the clinical efficacy of treating a large-animal model of an inborn error of hepatocyte metabolism in conjunction with a method for sensitively measuring correction in vivo. These studies will be applicable to human trials of the treatment of this disorder and other related urea-cycle disorders.

Evaluation of gene therapy for citrullinaemia using murine and bovine models.

Citrullinaemia is an autosomal recessive disorder caused by the deficiency of argininosuccinate synthase. The deficiency of this enzyme results in an interruption in the urea cycle and the inability to dispose of excess ammonia derived from the metabolism of protein. The only treatment for this disorder has been dietary restriction of protein and supplementation with medications allowing for alternative excretion of excess nitrogen. Gene therapy offers the possibility of a long-term cure for disorders like citrullinaemia by expressing the deficient gene in the target organ. We have explored the use of adenoviral vectors as a treatment modality for citrullinaemia in two animal models, a naturally occurring bovine model and a murine model created by molecular mutagenesis. Mice treated with adenoviral vectors expressing argininosuccinate synthase lived significantly longer than untreated animals (11 days vs 1 day; however, the animals did not exhibit normal weight gain during the experiment, indicating that the therapeutic effectiveness of the transducing virus was suboptimal. It is speculated that part of the failure to observe better clinical outcome might be due to the deficiency of arginine. In the bovine model, the use of adenoviral vectors did not result in any change in the clinical condition of the animals or in the level of plasma ammonia. However, the use of 15N isotopic ammonia allowed us to assess the flux of nitrogen through the urea cycle during the experiment. These studies revealed a significant increase in the flux through the urea cycle following administration of adenoviral vectors expressing argininosuccinate synthase. We conclude that the use of adenoviral vectors in the treatment of citrullinaemia is a viable approach to therapy but that it will be necessary to increase the level of transduction and to increase the level of enzyme produced from the recombinant viral vector. Future experiments will be designed to address these issues.