Quantitative value chain approaches for animal health and food safety.

Economic impact assessments are increasingly important in the context of animal health and food safety, although much of the existing literature does not address the broader systems context in which disease transmission takes place. In this paper, we discuss the role of system dynamics modeling in addressing the value chain impacts associated with animal health and food safety issues. System dynamics methods hold promise as a means of capturing the complex feedbacks that exist between the biology, economics, and behavioral aspects of food safety and animal health systems. We provide a proof-of-concept of this approach in the context of food safety and animal health in the smallholder pig sector of Viet Nam. Results highlight the important tradeoffs that exist between policy objectives and the costs required to achieve them.

Sensitivity and Specificity Estimation for the Clinical Diagnosis of Highly Pathogenic Avian Influenza in the Egyptian Participatory Disease Surveillance Program.

Many developing countries lack sufficient resources to conduct animal disease surveillance. In recent years, participatory epidemiology has been used to increase the cover and decrease the costs of surveillance. However, few diagnostic performance assessments have been carried out on participatory methods. The objective of the present study was to estimate the diagnostic performance of practitioners working for the Community-Based Animal Health and Outreach (CAHO) program, which is a participatory disease surveillance system for the detection of highly pathogenic avian influenza outbreaks in Egypt. CAHO practitioners' diagnostic assessment of inspected birds was compared with real-time reverse-transcriptase polymerase chain reaction (RRT-PCR) test results at the household level. Diagnostic performance was estimated directly from two-by-two tables using RRT-PCR as a reference test in two different scenarios. In the first scenario, only results from chickens were considered. In the second scenario, results for all poultry species were analyzed. Poultry flocks in 916 households located in 717 villages were inspected by CAHO practitioners, who collected 3458 bird samples. In the first scenario, CAHO practitioners presented sensitivity (Se) and specificity (Sp) estimates of 40% (95% confidence interval [CI]: 21%-59%) and 92% (95% CI: 91%-94%), respectively. In the second scenario, diagnostic performance estimates were Se = 47% (95% CI: 29%-65%) and Sp = 88% (95% CI: 86%-90%). A significant difference was observed only between Sp estimates (P < 0.01). Practitioners' diagnostics and RRT-PCR results were in very poor agreement with kappa values of 0.16 and 0.14 for scenarios 1 and 2, respectively. However, the use of a broad case definition, the possible presence of immunity against the virus in replacement birds, and the low prevalence observed during the survey would negatively affect the practitioners' performance.

On dogs, people, and a rabies epidemic: results from a sociocultural study in Bali, Indonesia.

BACKGROUND: Previously free of rabies, Bali experienced an outbreak in 2008, which has since caused a large number of human fatalities. In response, both mass dog culling and vaccination have been implemented. In order to assess potential community-driven interventions for optimizing rabies control, we conducted a study exploring the relationship between dogs, rabies, and the Balinese community. The objectives of this study were to: i) understand the human-dog relationship in Bali; ii) explore local knowledge, attitudes, and practices (KAPs) relating to rabies; and iii) assess potential community-driven activities to optimize rabies control and surveillance. METHODS: Conducted between February and June 2011, the study combined a questionnaire (n = 300; CI = 95 %; error margin = 5 %) and focus group discussions (FGDs) in 10 villages in the Denpasar, Gianyar, and Karangasem regencies. The questionnaire included a Likert scale to assess community knowledge and attitudes. For the knowledge assessment, three points were given for a correct answer, while wrong answers and uncertain answers were given zero points. For the attitudes assessment, three points were given for a positive answer, two points for a neutral answer, and one point for a negative answer. Respondent knowledge was categorized as good (score >40), fair (score 20-40), or poor (score <20), based on a maximum total score 60. Respondent attitudes were categorized as positive (score >26), neutral (score 13-26), or negative (score <13), based on a maximum total score of 39. Mixed-gender FGDs in each sub-village (banjar) were conducted, each involving 7-15 participants to complement the questionnaire results. On a follow-up research trip in mid-2013, the data analysis was triangulated and validated using semi-structured interviews. Questionnaire data were analyzed descriptively using SPSS 17.0, while qualitative data from interviews and FGDs were analyzed manually according to accepted methods of coding and memo writing. The chi-square test was then used to analyze the statistical relationships between knowledge and attitudes of the respondents. RESULTS: Out of the total 300 respondents, most were predominantly male (82 %), Hindu (99 %), married (96 %), older than 30 years of age (9 %), and owned dogs (72 %). Dog ownership was motivated by culture, personal taste, and function, with dogs was being used as guards (85 %) and companion animals (27 %), and was sometimes related to religious or traditional obligations (2 %). Relating to their culture and local beliefs, and eventually becoming their way of life, 79 % of respondents kept free-roaming dogs. With the rabies outbreak in Bali and Western breeds becoming more popular, more responsible dog ownership (leashing, confining, regular feeding) became more acceptable and changed community perceptions on keeping dogs, even though the sustainability of this practice cannot be gauged. In addition, the economic situation posed major problems in rural areas. The level of community knowledge about rabies and its associated control programs were generally fair and community attitudes were positive. However, community KAPs still need to be improved. A total of 74 % respondents reported to have vaccinated their dogs in 2011, but only few were found to report rabid animals to livestock officers (12 %) and a significant number believed that washing a bite wound was not important (62 %). Moreover, free-roaming dog practices and discarding of unwanted female puppies still continue and possibly create difficulties for rabies elimination as these practices potentially increase the stray dog population. We identified three major sociocultural aspects with potential for community-driven interventions to optimize current rabies elimination efforts: integrating local notions of ahimsa (non-violence) into education campaigns, engaging communities through the local banjar sociopolitical system, and working with traditional legal structures to increase local compliance with rabies control. CONCLUSION: The human-dog relationship in Bali is multifaceted. Due to the uniqueness of the culture and the local beliefs, and encouraged by a socioeconomic aspect, a number of local practices were found to be constituting risk factors for continued rabies spread. Community knowledge and attitudes, which can consequently result in behavioral changes, needs to be improved across different genders, ages, educational backgrounds, and roles in the community, regardless of the individual village's experiences with rabies. Furthermore, community-driven activities based on sociocultural conditioning and community capacity at the banjar and village levels, such as public awareness activities, vaccination, dog registration, dog population management, and rapid response to dog bites, were identified as being able to complement the rabies control program in Bali. The program also needs recognition or acknowledgement from governments, especially local government as well as regular mentoring to improve and sustain community participation.

The effectiveness of preventative mass vaccination regimes against the incidence of highly pathogenic avian influenza on Java Island, Indonesia.

We conducted an operational research study involving backyard and semicommercial farms on Java Island, Indonesia, between April 2008 and September 2009 to evaluate the effectiveness of two preventive mass vaccination strategies against highly pathogenic avian influenza (HPAI). One regimen used Legok 2003 H5N1 vaccine, while the other used both Legok 2003 H5N1 and HB1 Newcastle disease (ND) vaccine. A total of 16 districts were involved in the study. The sample size was estimated using a formal power calculation technique that assumed a detectable effect of treatment as a 50% reduction in the baseline number of HPAI-compatible outbreaks. Within each district, candidate treatment blocks with village poultry populations ranging from 80 000 to 120 000 were created along subdistrict boundary lines. Subsequently, four of these blocks were randomly selected and assigned one treatment from a list that comprised control, vaccination against HPAI, vaccination against HPAI + ND. Four rounds of vaccination were administered at quarterly intervals beginning in July 2008. A vaccination campaign involved vaccinating 100 000 birds in a treatment block, followed by another 100 000 vaccinations 3 weeks later as a booster dose. Data on disease incidence and vaccination coverage were also collected at quarterly intervals using participatory epidemiological techniques. Compared with the unvaccinated (control) group, the incidence of HPAI-compatible events declined by 32% (P = 0.24) in the HPAI-vaccinated group and by 73% (P = 0.00) in the HPAI- and ND-vaccinated group. The effect of treatment did not vary with time or district. Similarly, an analysis of secondary data from the participatory disease and response (PDSR) database revealed that the incidence of HPAI declined by 12% in the HPAI-vaccinated group and by 24% in the HPAI + ND-vaccinated group. The results suggest that the HPAI + ND vaccination significantly reduced the incidence of HPAI-compatible events in mixed populations of semicommercial and backyard poultry.

Strategies for the evaluation and selection of potential vaginal probiotics from human sources: an exemplary study.

During the last years, the application of probiotics in gynaecological clinical practice has gained increasing relevance regarding therapy and prevention. This trend has also provoked the need for having tailored pharmaceutical preparations containing powerful microbial strains with defined properties. For the development of such preparations, several factors and criteria have to be considered, thereby not only focusing on identity and safety aspects as well as individual properties of the bacterial strains, but also on technological issues, such as stability and targeted release from the preparation. Against this background, this report exemplarily addresses the development procedure of a probiotic bacterial formulation for gynaecological application, covering the search for suitable strains, assessing their microbiological, molecular biological and physiological characterisation, and the selection for their use in clinical trials. In detail, starting with 127 presumptive lactobacilli isolates of vaginal origin, a step-by-step selection of candidate strains meeting special criteria was thoroughly examined, finally leading to a preparation consisting of four individual Lactobacillus strains that possess particular significance in women's urogenital health. Relevant issues and quality criteria of probiotic preparations used in gynecology are addressed and exemplarily introduced.

[Stereotactic radiosurgery and fractionated stereotactic radiotherapy of acoustic neuromas]. / Stereotaktische Radiochirurgie und Radiotherapie bei Akustikusneurinomen.

Stereotactic radiosurgery (SRS) is a neurosurgical field that has become increasingly important in the treatment of acoustic neuromas. Radiosurgical treatment modalities include the Gamma knife, the linear accelerator (LINAC), and the CyberKnife. Gamma knife radiosurgery (GKRS) is still unsurpassed in terms of the spatial accuracy of radiation delivery and has been used for decades in acoustic neuromas (>18000 patients). In contrast to surgical resection, the goal of SRS is long-term prevention of tumour growth with preservation of neurological function. Radiation-induced neuropathies rarely occur. However, there are essential differences between SRS and fractionated stereotactic radiotherapy (FSR) in terms of both their radiobiological effects and their modes of application. SRS can be performed in an outpatient setting. Neuromas of up to 3 cm in diameter represent potential candidates for SRS or FSR. For larger tumours, cystic lesions and neuromas with brain stem compression, microsurgical resection in experienced neurosurgical centres is still the preferred option. SRS (and FSR) are possible options for patients with tumour progression after subtotal surgery or tumour recurrence, or for patients unable or unwilling to undergo surgery.

Integration of participatory approaches into surveillance systems.

Animal health surveillance is essential for protecting public health, enhancing access to international markets for animals and their products, and improving animal health, production and welfare. It is of vital importance for protecting and improving the livelihoods of diverse groups of livestock keepers and stakeholders in livestock value chains. Surveillance systems consist of sets of complementary components which generate information to inform risk assessment, decision-making and policy formulation for both national programmes and international trade. Participatory approaches have the potential to add value to surveillance systems by enhancing their performance, especially their sensitivity and timeliness, and encouraging the inclusion of marginalised groups. This paper summarises key considerations in the assessment and design of animal health surveillance and discusses how participatory approaches can be integrated into comprehensive surveillance systems, leading to a more effective overall outcome for both domestic and international purposes.

Phenotype-related differential alpha-2,6- or alpha-2,3-sialylation of glycoprotein N-glycans in human chondrocytes.

OBJECTIVE: Sialic acids frequently occur at the terminal positions of glycoprotein N-glycans present at chondrocyte surfaces or in the cartilage matrix. Sialic acids are transferred to glycoproteins in either alpha-2,3 or alpha-2,6 linkage by specific sialyltransferases (SiaTs) and can potentially affect cell functions and cell-matrix interactions. The present study aimed to assess the relationship between the expression of the human chondrocyte phenotype and the sialylation of chondrocyte glycoprotein N-glycans. METHODS: The transcription of 5 SiaT was quantified using real-time Reverse transcription polymerase chain reaction (RT-PCR) assays. N-glycan analysis was performed using LC-ESI-MS. Primary human chondrocytes were cultured in monolayer or alginate beads and compared to the chondrocyte cell lines C-28/I2 and SW1353. In addition, effects of interleukin-1beta (IL-1beta) or tumour necrosis factor-alpha (TNF-alpha) on primary cells were assessed. RESULTS: Primary human chondrocytes predominantly express alpha-2,6-specific SiaTs and accordingly, alpha-2,6-linked sialic acid residues in glycoprotein N-glycans. In contrast, the preponderance of alpha-2,3-linked sialyl residues and, correspondingly, reduced levels of alpha-2,6-specific SiaTs are associated with the altered chondrocyte phenotype of C-28/I2 and SW1353 cells. Importantly, a considerable shift towards alpha-2,3-linked sialic acids and alpha-2,3-specific SiaT mRNA levels occurred in primary chondrocytes treated with IL-1beta or tumour necrosis factor-alpha (TNF-alpha). CONCLUSION: The expression of the differentiated chondrocyte phenotype is linked to the ratio of alpha-2,6- to alpha-2,3-linked sialic acids in chondrocyte glycoprotein N-glycans. A shift towards altered sialylation might contribute to impaired cell-matrix interactions in disease conditions.

Staged gamma knife radiosurgery for large critically located benign meningiomas: evaluation of a series comprising 20 patients.

OBJECTIVES: This study investigated the efficacy of staged radiosurgical treatment for intracranial meningiomas exceeding 3 cm in diameter. METHODS: Between April 1992 and May 2008, staged gamma knife radiosurgery was performed in 20 patients with large benign meningiomas. 14 patients had undergone surgery at least once. The patients' ages ranged between 26 and 73 years (median 60.5). Tumour volumes measured between 13.6 and 79.8 cm(3) (median 33.3) and treatment volumes between 5.4 and 42.9 cm(3) (median 19.0). Of 41 treatments, the prescription dose at the tumour margin was 12 Gy for 33 treatments, 10 Gy for one treatment, 14 Gy for four treatments, 15 Gy for one treatment and 25 Gy for a further two treatments (median 12 Gy to a marginal isodose of 45%). Median follow-up was 7.5 years. RESULTS: Tumour control was achieved in 90% of our series (25% tumour regression, 65% stable size). Two patients (10%) experienced tumour progression outlying the planning target volumes treated by an additional radiosurgical procedure. Thereafter tumour volume decreased in one patient and remained stable in the second one. Clinically, nine patients (45%) improved within the time of follow-up and 11 (55%) remained unchanged. CONCLUSION: As a result of excellent tumour control at a low concomitant morbidity, staged radiosurgical treatment for meningiomas represents a safe treatment modality that can be recommended for meningiomas in critical locations either after incomplete surgery or as primary treatment for patients with significant comorbidity.

Lectin binding patterns reflect the phenotypic status of in vitro chondrocyte models.

In vitro studies using chondrocyte cell cultures have increased our understanding of cartilage physiology and the altered chondrocytic cell phenotype in joint diseases. Beside the use of primary cells isolated from cartilage specimens of donors, immortalized chondrocyte cell lines such as C-28/I2 and T/C-28a2 have facilitated reproducible and standardized experiments. Although carbohydrate structures appear of significance for cartilage function, the contribution of the chondrocyte glycocalyx to matrix assembly and alterations of the chondrocyte phenotype is poorly understood. Therefore, the present study aimed to evaluate the glycoprofile of primary human chondrocytes as well as of C-28/I2 and T/C-28a2 cells in culture. First, the chondrocytic phenotype of primary and immortalized cells was assessed using real-time reverse transcriptase polymerase chain reaction, immunofluorescence, and glycosaminoglycans staining. Then, a panel of lectins was selected to probe for a range of oligosaccharide sequences determining specific products of the O-glycosylation and N-glycosylation pathways. We found that differences in the molecular phenotype between primary chondrocytes and the immortalized chondrocyte cell models C-28/I2 and T/C-28a2 are reflected in the glycoprofile of the cells. In this regard, the glycocalyx of immortalized chondrocytes was characterized by reduced levels of high-mannose type and sialic acid-capped N-glycans as well as increased fucosylated O-glycosylation products. In summary, the present report emphasizes the glycophenotype as an integral part of the chondrocyte phenotype and points at a significant role of the glycophenotype in chondrocyte differentiation.

Epidemiological and ornithological aspects of outbreaks of highly pathogenic avian influenza virus H5N1 of Asian lineage in wild birds in Germany, 2006 and 2007.

In Germany, two distinct episodes of outbreaks of highly pathogenic avian influenza virus of subtype H5N1 (HPAIV H5N1) in wild birds occurred at the beginning of 2006, and in summer 2007. High local densities of wild bird populations apparently sparked clinically detectable outbreaks. However, these remained restricted in (i) number of birds, (ii) species found to be affected, (iii) time, and (iv) location despite the presence of several hundred thousands of susceptible wild birds and further stressors (food shortage, harsh weather conditions and moulting). Northern and southern subpopulations of several migratory anseriform species can be distinguished with respect to their preference for wintering grounds in Germany. This corroborates viral genetic data by Starick et al. (2008) demonstrating the introduction of two geographically restricted virus subpopulations of Qinghai-like lineage (cluster 2.2.A and 2.2.B) into northern and southern Germany, respectively, in 2006. The incursion of virus emerging in 2007, found to be distinct from the clusters detected in 2006 (Starick et al., 2008), may have been associated with moulting movements. Intensive past-outbreak investigations with negative results of live and dead wild birds and of terrestrial scavengers excluded continued circulation of virus on a larger scale. However, persistence of virus in small pockets of local wild bird populations could not be ruled out resiliently. 1.5% of investigated sera originating from cats sampled at the epicentres of the Ruegen 2006-outbreak contained H5-antibodies. Passive monitoring was found to be highly superior to live bird surveillance when aiming at the detection of HPAIV H5N1 in wild birds (P < 0.0001).

Recurrent trigeminal neuralgia: long term outcome of repeat gamma knife radiosurgery.

OBJECTIVE: To date, the efficacy and safety of repeat radiosurgery (RS) for trigeminal neuralgia (TN) is based mainly on short term results. METHODS: Between 1994 and 2006, 93 patients were treated by RS for TN at the Department of Neurosurgery, Graz, Austria. 22 patients underwent repeat gamma knife radiosurgery (GKRS) a mean of 18.8 months after the initial treatment. The mean dose for repeat treatment was 74.3 Gy. Pain outcome was rated using the Barrow Neurological Institute (BNI) Pain Intensity Scale and facial numbness according to the BNI Facial Numbness Scale. RESULTS: Mean follow-up after repeat RS was 5.4 years. Pain relief was noted in 72.7% (16/22) of patients; six patients had a second pain recurrence after a mean of 9.3 months and underwent medical, alternative and/or further RS. One patient was lost to follow-up. BNI pain scale evaluation for 21 patients indicated improvement in 76.2% (16/21) of cases without medication (BNI I and II). Facial numbness was recorded in 73.7% (14/19) but in only one was it classified as bothersome. CONCLUSIONS: Long term observation of repeat GKRS for TN showed good pain relief in more than two-thirds of patients. Despite a high percentage of facial numbness, most likely attributable to the higher delivered dose, repeat RS can still be regarded as safe. However, further studies are needed to determine an optimised treatment protocol.

Comparison between chondroprotective effects of glucosamine, curcumin, and diacerein in IL-1beta-stimulated C-28/I2 chondrocytes.

OBJECTIVE: To compare the effects of glucosamine (GlcN), curcumin, and diacerein in immortalized human C-28/I2 chondrocytes at the cellular and the gene expression level. This study aimed to provide insights into the proposed beneficial effects of these agents and to assess the applicability of the C-28/I2 cell line as a model for the evaluation of chondroprotective action. METHODS: Interleukin-1beta (IL-1beta)-stimulated C-28/I2 cells were cultured in the presence of GlcN, curcumin, and diacerein prior to the evaluation of parameters such as viability, morphology and proliferation. The impact of GlcN, curcumin, and diacerein on gene expression was determined using quantitative real-time RT-PCR (qPCR). RESULTS: At the transcriptional level, 5 mM GlcN and 50 microM diacerein increased the expression of cartilage-specific genes such as aggrecan (AGC) and collagen type II (COL2), while reducing collagen type I (COL1) mRNA levels. Moreover, the IL-1beta-mediated shift in gene expression pattern was antagonized by GlcN and diacerein. These effects were associated with a significant reduction in cellular proliferation and the development of chondrocyte-specific cell morphology. In contrast, curcumin was not effective at lower concentrations but even damaged the cells at higher amounts. CONCLUSIONS: Both GlcN and diacerein promoted a differentiated chondrocytic phenotype of immortalized human C-28/I2 chondrocytes by altering proliferation, morphology, and COL2/COL1 mRNA ratios. Moreover, both agents antagonized inhibitory effects of IL-1beta by enhancing AGC and COL2 as well as by reducing COL1 mRNA levels.

Poly(ethylene carbonate): a thermoelastic and biodegradable biomaterial for drug eluting stent coatings?

A first feasibility study exploring the utility of poly(ethylene carbonate) (PEC) as coating material for drug eluting stents under in vitro conditions is reported. PEC (Mw 242 kDa, Mw/Mn=1.90) was found to be an amorphous polymer with thermoelastic properties. Tensile testing revealed a stress to strain failure of more than 600%. These properties are thought to be advantageous for expanding coated stents. In vitro cytotoxicity tests showed excellent cytocompatibility of PEC. Based on these findings, a new stenting concept was suggested, pre-coating a bare-metal stent with PPX-N as non-biodegradable basis and applying a secondary PEC coating using an airbrush method. After manual expansion, no delamination or destruction of the coating could be observed using scanning electron microscopy. The surface degradation-controlled release mechanism of PEC may provide the basis for "on demand" drug eluting stent coatings, releasing an incorporated drug predominantly at an inflamed implantation site upon direct contact with superoxide-releasing macrophages. As a release model, metal plates of a defined size and area were coated under the same conditions as the stents with PEC containing radiolabelled paclitaxel. An alkaline KO(2-) solution served as a superoxide source. Within 12 h, 100% of the incorporated paclitaxel was released, while only 20% of the drug was released in non-superoxide releasing control buffer within 3 weeks.

Branched polyesters based on poly[vinyl-3-(dialkylamino)alkylcarbamate-co-vinyl acetate-co-vinyl alcohol]-graft-poly(d,l-lactide-co-glycolide): effects of polymer structure on cytotoxicity.

Branched polyesters of the general structure poly[vinyl-3-(dialkylamino)alkylcarbamate-co-vinyl acetate-co-vinyl alcohol]-graft-poly(d,l-lactide-co-glycolide) have shown potential for nano- and micro-scale drug delivery systems. For further optimization of this polymer class their cytotoxicity needs to be characterized establishing structure-toxicity relationships. Effects of type and degree of amine substitution as well as molecular weight on cytotoxicity were evaluated in L929 mouse fibroblasts using a MTT assay whereas interactions with cell membranes were quantified by LDH release and caspase (3/7)-activation. Finally, direct cell-polymer contact assays were conducted. Ungrafted amine-modified polymer backbone yielded IC(50) values in the range of 0.05-10mg/ml. Generally higher toxicities were observed with an increasing degree of amine substitution. Amine substituents could be ranked as diethylaminopropylamine (DEAPA)

Lectin binding studies on C-28/I2 and T/C-28a2 chondrocytes provide a basis for new tissue engineering and drug delivery perspectives in cartilage research.

The present study was performed to evaluate the applicability of plant lectins as mediators of bioadhesion in cartilage research using human chondrocyte cell lines C-28/I2 and T/C-28a2. The bioadhesive properties of fluorescein-labelled lectins with different carbohydrate specificities were investigated by flow cytometry. Specificity of the lectin-cell interactions was ascertained by competitive inhibition using complementary carbohydrates. As compared to that of other lectins, the interaction between wheat germ agglutinin (WGA) and chondrocytic cells was characterised by remarkable cytoadhesion, adequate binding strength and a high degree of specificity for N-acetyl-glucosamine as contained in hyaluronan chains. We therefore suggest WGA to be a promising candidate for mediating bioadhesion to low-adhesive scaffolds in cartilage tissue engineering. Moreover, the WGA-association rate of C-28/I2 and T/C-28a2 cells was dependent on temperature indicating cellular uptake of membrane-bound WGA. Intracellular enrichment was confirmed by confocal microscopy. Equilibration of intracellular pH gradients with monensin resulted in the reversal of quenching effects indicating accumulation of WGA within acid compartments of chondrocytic cells. Thus, WGA might be internalised into chondrocytes together with hyaluronan via the CD44 receptor-mediated endocytosis pathway and accumulated within lysosomes. This physiological process could represent a feasible pathway to target WGA-functionalised drug delivery devices into chondrocytes.

Combined endoscopic surgery and radiosurgery as treatment modality for olfactory neuroblastoma (esthesioneuroblastoma).

OBJECT: Treatment of esthesioneuroblastoma (olfactory neuroblastoma) has been considerably improved by microsurgical techniques. Nevertheless, these rare tumours of the frontal skull base are still associated with high rates of tumour recurrence and mortality, thus remaining a challenge even for experienced surgeons. A novel therapeutic approach that combines endoscopic sinus surgery and Gamma Knife radiosurgery is presented here. Taking into account the rarity of the disease the present study comprises a relatively large series of patients treated in a similar manner. METHODS: 14 patients (8 males, 6 females) aged 27-75 years (median 38) were treated between May 1993 and December 2003. This series comprises 12 newly diagnosed esthesioneuroblastomas. Two more patients had already previously undergone surgery (24/39 months earlier). Paranasal and nasal endoscopic sinus surgery was performed. Marginal irradiation doses ranging from 15-34 Gy were given to the residual tumours by means of radiosurgery (Gamma Knife) involving 1-7 isocentres within 3 months after surgery. Median follow-up is 58 months (range 13-128). RESULTS: There was no mortality. In all patients tumour control was achieved within the treated area. 4 patients underwent a second radiosurgical procedure 6-79 months (median 34 months) after initial radiosurgery. One patients had to undergo an additional craniotomy because of extensive neoplastic infiltration, 1 developed postoperative liquorrhea, 1 case was complicated by bilateral frontal sinusitis. All patients complained of nasal discharge and crusts. Karnovsky Index--preoperatively ranging from 80%-100%--remained stable in 12 patients, an improvement was observed in 2 cases. CONCLUSIONS: Based on the favourable results recorded so far, the combination of endoscopic sinus surgery and radiosurgery can be considered a promising treatment option for esthesioneuroblastoma that merits further consideration.

Endemic stability for Theileria parva infections in Ankole calves of the Ankole ranching scheme, Uganda.

A population-based study was carried out on the Ankole ranching scheme in south-west Uganda with the aim of determining the endemic status of Theileria parva infections. For this purpose, the age-related sero-prevalence of T. parva and the specific calf mortality associated with the parasite were assessed. Blood samples were collected from 931 Ankole calves of up to 12 months of age from 81 randomly selected herds. The relationship between rainfall pattern and whole-body Rhipicephalus appendiculatus counts was determined. The influence of tick control practices on East Coast fever-related calf mortality, and sero-positivity were also determined. A significant (r2 = 0.76, P = 0.000) association between R. appendiculatus counts and rainfall was observed. There was no significant (P > 0.05) association between theileriosis-related calf mortality, sero-positivity and the different tick control practices. Antibody prevalence based on the PIM ELISA was above 70% among calves of 6 months of age in 96% in all the herds. Theileria parva-related calf mortality determined by repeated herd visits and farm records ranged between 0 % and 5.4 %. It was concluded that endemic stability for theileriosis, caused by T. parva, existed in the study area, and that the risk of the occurrence of economically important outbreaks of East Coast fever in indigenous cattle was regarded as minimal under the prevailing conditions.