Investigation into the genotoxicity of water extracts from Hypoxis species and a commercially available Hypoxis preparation.

We performed an in vitro evaluation of the genotoxic potential of water extracts from four Hypoxis species (Hypoxis hemerocallidea, H. colchicifolia, H. rigidula, H. acuminata) and a commercial preparation thereof using the neutral red uptake (NRU) assay, the alkaline comet assay and the cytome assay in human hepatoma HepG2 cells. The relative cytotoxicity of these samples was established by determining their NI50 values (50% inhibition of NRU), and these results were used for dose-finding in genotoxicity tests. None of the tested extracts were identified as genotoxic in both the alkaline comet assay and cytome assay.

Influence of foot conformation on duration of competitive life in a Dutch Warmblood horse population.

REASONS FOR PERFORMING STUDY: Warmblood horse studbooks aim to breed horses with a conformation that will enable elite future sports performance, but reduce the risk of early retirement due to lameness. Negative conformational traits, such as asymmetrical or 'uneven' forefeet may possibly shorten the career of sporthorses. OBJECTIVES: To investigate the significance of foot conformation at young age to duration of the career of sporthorses. METHODS: Databases of the Royal Dutch Warmblood Studbook (KWPN) and of the Royal Dutch Equestrian Sports Federation (KNHS) were matched and resulted in a dataset comprising 23,116 records of horses for which their conformation scores and duration of their sports career were available. Survival analysis was used to determine which of the conformation traits had a significant effect on duration of sports career in dressage and jumping at basic and elite level. RESULTS: Duration of competitive life was shorter for jumping than for dressage. A different set of risk factors was found for each level and discipline. The trait 'uneven feet' tended to shorten the competitive life in dressage, but was a significant risk factor at the elite level of jumping. CONCLUSIONS: Limb conformation and, in particular, the conformation of the distal limb, are important for duration of competitive life. From the prevalence of uneven feet in sports disciplines, it may be concluded that this is an undesirable trait, particularly at the elite level of jumping, since uneven feet have a detrimental effect on the duration of competitive life in a sporthorse population. POTENTIAL RELEVANCE: This study provided evidence that the conformation trait uneven feet has a negative effect on Warmblood jumping performance and, therefore, breeders should be encouraged to avoid this phenomenon at foal age.

Trabecular and subchondral bone development of the talus and distal tibia from foal to adult in the warmblood horse.

Horses are precocial animals and able to stand and walk within hours after birth. To cope with associated loading, intrauterine bone development has shown to be anticipative. This study provides further insight into the post-natal development of structurally important features of trabecular and subchondral bone of the talus and sagittal ridge of the tibia of warm-blooded horses. In all areas studied, the average bone volume fraction showed a gradual increase over time, which was the result of a significant increase in trabecular thickness, without significant changes in the degree of anisotropy. Similar to the mineralised part of the bone, collagen content, measured as average retardation using polarised light microscopy, increased significantly, but the degree of anisotropy of the collagen type I network did not. At birth, the subchondral bone layer had a more trabecular aspect, gradually changing to an even surface with only a few vascular canals at an age of 2 months. Presented results indicate the necessity for a stronger structure, but not for a different structural design after birth, providing further evidence for anticipatory bone development in the horse. More knowledge about the strategies used to cope with mechanical loading after birth might be helpful in understanding the developmental bone and joint diseases.

The development of hoof balance and landing preference in the post-natal period.

BACKGROUND: Foals can follow the herd within hours of birth, but it has been shown that kinetic gait parameters and static balance still have to mature. However, development of dynamic balance has not been investigated. OBJECTIVES: To objectively quantify landing and pressure pattern dynamics under the hoof during the first half year of life. STUDY DESIGN: Prospective, cohort study performed at a single stud farm. METHODS: Pressure plate measurements at walk and trot from ten Dutch warmblood foals during the first 24 weeks of life were used to quantify toe-heel and medial-lateral hoof balance asymmetry indexes and to determine preferred landing strategy. Concurrently, radiographs of the tarsocrural and femoropatellar joints were taken at 4-6 weeks and after 6 months to check for osteochondrosis. A linear mixed model was used to determine the effects of time point, limb pair (front/hind), side (left/right) and osteochondrosis status of every foal. RESULTS: At 25% of stance duration at walk, front limbs were more loaded in the heel region in weeks 6-20 (P≤0.04), the medial-lateral balance was more to the lateral side from week 6 onwards at both walk and trot (P≤0.04). Landing preference gradually changed in the same directions. Variability in pressure distribution decreased over time. (Subclinical) osteochondrosis did not influence any of the measured parameters. MAIN LIMITATIONS: This study is limited by the relatively small sample size only containing one breed from a single stud farm. CONCLUSIONS: Dynamic hoof balance in new-born foals is more variable and less oriented towards the lateral side of the hoof and to the heel than in mature horses. This pattern changes gradually during the first weeks of life. Knowledge of this process is essential for the clinician when considering interventions in this area in early life.

The development of locomotor kinetics in the foal and the effect of osteochondrosis.

REASON FOR PERFORMING STUDY: Foals stand and walk immediately after birth, but insight into the subsequent longitudinal development of their gait kinetics in the early juvenile phase and the possible influence of osteochondrosis thereon is lacking. OBJECTIVES: To quantify gait kinetics in foals during the first half year of life, taking into account their osteochondrosis status. STUDY DESIGN: Prospective, cohort study performed at a single stud farm. METHODS: Pressure plate measurements at walk and trot from 11 Dutch Warmblood foals during the first 24 weeks of life were used to determine body mass normalised peak vertical force, normalised vertical impulse and stance duration. Coefficients of variation of peak vertical force and stance duration were used as measures for gait maturity. Radiographs of tarsocrural and femoropatellar joints were taken at age 4-6 weeks and after 6 months to check for osteochondrosis. A linear mixed model was used to determine the effects of age, limb, presence of osteochondrosis and speed on gait parameters. RESULTS: Mean walking and trotting velocity increased over time as did stance duration and normalised vertical impulse, normalised peak vertical force values however remained relatively constant. During the first weeks of their life only the coefficient of variation of stance duration decreased significantly, while the coefficient of variation of peak vertical force did not. None of the foals was visibly lame, but the presence of osteochondrosis resulted in a temporarily but significantly reduced normalised peak vertical force. MAIN LIMITATIONS: This study is a relatively small sample size of one breed from a single stud farm. A stand-alone pressure plate was used and body mass was estimated rather than measured. CONCLUSIONS: Despite being precocious, foals need time to mature their gait. During growth, velocity at walk and trot increases, but normalised peak vertical force remains relatively constant. Although not visibly lame, a temporary reduction in normalised peak vertical force was detected in osteochondrosis positive foals using a pressure plate.

High-dose-rate prostate brachytherapy inverse planning on dose-volume criteria by simulated annealing.

High-dose-rate brachytherapy is a tumor treatment method where a highly radioactive source is brought in close proximity to the tumor. In this paper we develop a simulated annealing algorithm to optimize the dwell times at preselected dwell positions to maximize tumor coverage under dose-volume constraints on the organs at risk. Compared to existing algorithms, our algorithm has advantages in terms of speed and objective value and does not require an expensive general purpose solver. Its success mainly depends on exploiting the efficiency of matrix multiplication and a careful selection of the neighboring states. In this paper we outline its details and make an in-depth comparison with existing methods using real patient data.

Incidence of dysarthria in children with cerebellar tumors: a prospective study.

The present study investigated dysarthric symptoms in children with cerebellar tumors. Ten children with cerebellar tumors and 10 orthopedic control children were tested prior and one week after surgery. Clinical dysarthric symptoms were quantified in spontaneous speech. Syllable durations were analyzed in syllable repetition and sentence production tasks. Localization of the cerebellar lesions were defined after manual transfer from individual 2D-MR images onto 3D images of a spatially normalized healthy brain. Cerebellar children showed few and mild clinical signs of dysarthria. No difference was present in the sentence production task compared to controls. In five cerebellar children, syllables were prolonged in the syllable repetition task after surgery. Syllable duration normalized in an additional four-week session in all but one case. The MR-analysis showed that superior paravermal cerebellar areas likely involved in dysarthria in adults (paravermal lobules HVI, Crus I) were not significantly affected. In children, speech impairments appear to be rare after cerebellar surgery because tumors most commonly affect posterior-inferior and medial parts of the cerebellum while critical cerebellar regions are likely spared. The results suggest a similar localization of speech functions in the cerebellum in children and adults.

Cerebellar mutism--report of four cases.

The aim of the present study was to investigate the manifestations of mutism after surgery in children with cerebellar tumors. Speech impairment following cerebellar mutism in children was investigated based on standardized acoustic speech parameters and perceptual criteria. Mutistic and non-mutistic children after cerebellar surgery as well as orthopedic controls were tested pre-and postoperatively. Speech impairment was compared with the localization of cerebellar lesions (i. e. affected lobules and nuclei). Whereas both control groups showed no abnormalities in speech and behavior, the mutistic group could be divided into children with dysarthria in post mutistic phase and children with mainly behavioral disturbances. In the mutistic children involvement of dentate and fastigial nuclei tended to be more frequent and extended than in the nonmutistic cerebellar children. Cerebellar mutism is a complex phenomenon of at least two types. Dysarthric symptoms during resolution of mutism support the anarthria hypothesis, while mainly behavioral changes suggest an explanation independent from speech motor control.

A rare anatomical variation: a case of a common celiacomesenteric trunk in a cat.

In this study, we present a cat with a common 1-cm-long celiacomesenteric trunk. The arteria hepatica branched off first from the separate arteria celiaca and gave rise to the arteria gastrica dextra and arteria gastroduodenalis. The main stem of the arteria celiaca then split into the arteria gastrica sinistra and the arteria lienalis. The arteria mesenterica cranialis extended ventrocaudally in the mesentery. This variation is due to developmental changes in the ventral splanchnic arteries, and they are quite varied. The basic architecture and perfused organs are comparable, which indicates that the presence of a common celiacomesenteric trunk is more related to individual development than to phylogeny or function.

[Chylopericardium following pulmonary tuberculosis]. / Chyloperikard nach Lungentuberkulose.

HISTORY: A 22-year old man was admitted with a large pericardial effusion after he had been successfully treated for tuberculosis of the right lung for 6 months. Treatment had been discontinued according to plan 4 months before the current admission. The patient was only mildly symptomatic with exertional dyspnea of 3 weeks duration. Body temperature, pulse rate and blood pressure were within normal limits. The neck veins were not distended. INVESTIGATIONS AND DIAGNOSIS: Laboratory data were unremarkable. The patient underwent thoracoscopy for pericardial drainage. A large chylous effusion was removed. CLINICAL COURSE: Drainage ceased over the following months after the patient had been on a medium-chain triglyceride diet. On follow-up 9 months later, the patient was asymptomatic and without evidence of cardiopulmonary disease. CONCLUSION: We presume (A) that the tuberculous infection had affected the mediastinal lymph nodes and (B) that the fibrous contraction of perinodal tissue caused a temporary obstruction of the thoracic duct at a later stage in the course of the healing process with subsequent reflux of chyle into the pericardial cavity via lymphatic vessels that normally drain the pericardium.

[Weil's syndrome with bone marrow involvement after collecting walnuts]. / Morbus Weil mit Knochenmarkbefall nach Walnusssammeln.

HISTORY AND CLINICAL FINDINGS: A 65 year-old man was transferred to our department from a neighbouring hospital with anuria and epistaxis. A few days prior to hospitalization, he had experienced severe muscular and joint pain accompanied by chills. A careful history revealed that, in recent weeks, the patient had frequently collected wild walnuts growing, for the most part, on the banks of a small stream, known to have an infestation of rats. The physical examination revealed pronounced jaundice of the skin and sclerae, and petechia on the lower legs. INVESTIGATIONS: Laboratory results showed marked thrombocytopenia, hyperbilirubinaemia, appreciably elevated urine retention parameters and increased C-reactive protein. During the subsequent course of his illness, serum leptospiral antibody titres were elevated, indicating an acute leptospiral infection manifesting as Weil's syndrome. Silver staining (>>Warthin-Starry<<) revealed rod-shaped bacteria, presumably representing leptospires, in some bone marrow macrophages. TREATMENT AND COURSE: Treatment with i. v. penicillin was immediately initiated, and urine output established by intravenous fluid resuscitation in the intensive care unit, so that haemodialysis was not necessary. The platelet count returned to normal and bilirubin began to decrease again. The patient was discharged home after 2 weeks in the hospital. CONCLUSION: When a patient presents with the triad of renal failure, jaundice and thrombocytpenia in the setting of a possible infection, then the severe form of leptospirosis known as Weil inverted question marks syndrome must be considered, and antibiotic treatment initiated without delay. Of importance for the definitive diagnosis is the repeated determination of the titres of antibodies to leptospires in the serum and urine, which usually become positive only in the second week of the illness. In our case, we detected bacteria directly in some bone marrow macrophages as well.

Do children with focal cerebellar lesions show deficits in shifting attention?

More recent findings suggest a possible role of the cerebellum in nonmotor functions. Disability of individuals with cerebellar damage in rapidly shifting attention is one frequently used example to support cerebellar involvement in mental skills. The original proposal was based on findings in five children with chronic surgical lesions of the cerebellum and a young adult with a degenerative disorder. The aim of the present study was to repeat Akshoomoff and Courchesne's initial findings in a larger group of children with focal cerebellar lesions. Ten children with cerebellar lesions and 10 age- and sex-matched controls were tested. Neocerebellar areas were affected in all children with cerebellar damage except one based on detailed analysis of MRI scans. Subjects had to perform a focus and a shift attention task. Two visual and two auditory stimuli were presented in a pseudorandom order. An ellipse and a high-pitched tone were presented less frequently than a circle and a low-pitched tone. Rare stimuli were presented at five different time intervals. In the focus tasks, subjects had to react to the same rare stimulus of one of the two modalities. In the shift task, subjects had to switch between the two rare stimuli. Motor deficits based on reaction times were small in cerebellar children compared with controls. The ability of target detection did not significantly differ in the children with cerebellar lesions compared with the control children in both the focus and the shift attention task. In particular, children with cerebellar damage showed no significant impairment in rapid (<2 s) shifts of attention. The present findings indicate that the cerebellum may be less critical in attention related processes than suggested previously.