Faculty and student perceptions of the feasibility of individual student-faculty meetings.

The extent to which students feel involved in their education positively influences academic achievement. Individual student-faculty meetings can foster student involvement. To be effective, faculty acknowledgement of the benefit of these meetings is a prerequisite. The aim of this study was to explore faculty perceptions of individual student-faculty meetings. In addition we investigated students' perceptions. As part of the undergraduate programme, mandatory individual intake and follow-up meetings between first-year medical students (n = 425) and senior faculty members (n = 34) have been implemented from 2009 onwards. We administered a questionnaire on faculty perceptions of the benefit and impact of intake meetings. Subsequently, after both meetings had been held, strong and weak points of the mandatory programme were explored using open-ended questions. Students' perceptions were investigated by open-ended questions as a part of the curriculum evaluation process. Faculty enjoyed the meetings (90 %), perceived the meetings to be beneficial (74 %) and expected a positive effect on student involvement (74 %). Faculty appreciated the opportunity to give advice tailored to students' personal needs and levels of performance. The students appreciated the meetings and the attention given to their personal situation and study progress. Faculty and student appreciation of the meetings seems to support the assumption that the individual meetings increase students' social and academic involvement. Further research should focus on the impact of individual student-faculty meetings on students' learning behaviours.

A pilot study on objective quantification and anatomical modelling of in vivo head and neck positions commonly applied in training and competition of sport horses.

REASONS FOR PERFORMING STUDY: Head and neck positions (HNP) in sport horses are under debate in the equine community, as they could interfere with equine welfare. HNPs have not been quantified objectively and no information is available on their head and neck loading. OBJECTIVES: To quantify in vivo HNPs in sport horses and develop o a model to estimate loading on the cervical vertebrae in these positions. METHODS: Videos were taken of 7 Warmbloods at walk on a straight line in 5 positions, representing all HNPs during Warmblood training and competition. Markers were glued at 5 anatomical landmarks. Two-dimensional angles and distances were determined from video frames for the 5 HNPs and statistically compared (P < 0.05). A new simulation model was developed to estimate nuchal ligament cervical loading at these HNPs. RESULTS: The mean angles were significantly different between the 5 HNPs for the line between C1 and T6 with the horizontal and for the line connecting the facial crest (CF) and C1 with the vertical, while the vertical distance from CF to the lateral styloid process of the radius (PS) was significantly different between all 5 positions (P < 0.05). The estimated nuchal ligament loading appeared to be largest at the origin of C2 for all HNPs, except for the 'hyperextended' HNP5; the 'hyperflexed' HNP4 showed the largest loading values on the nuchal ligament origins at all locations. CONCLUSIONS: HNPs can be accurately quantified in the sagittal plane from angles and distances based on standard anatomical landmarks and home-video captured images. Nuchal ligament loading showed the largest estimated values at its origin on C2 in hyperflexion (HNP4). POTENTIAL RELEVANCE: Modelling opens further perspectives to eventually estimate loading for individual horses and thus ergonomically optimise their HNP, which may improve the welfare of the sport horse during training and competition.

Quantification of surface EMG signals to monitor the effect of a Botox treatment in six healthy ponies and two horses with stringhalt: preliminary study.

REASONS FOR PERFORMING THE STUDY: Therapeutic options for stringhalt in horses are limited, whereas medical experiences with botulinum toxin type A (Botox) have been positive. To evaluate its effectiveness in horses, surface electromyography (sEMG) signals before and after injection need to be quantified. HYPOTHESIS: Treatment of healthy ponies and cases with Botox should reduce muscle activity in injected muscles and reduce spastic movements without adverse side effects. METHODS: Unilaterally, the extensor digitorum longus, extensor digitorum lateralis and lateral vastus muscles of 6 healthy mature Shetland ponies and 2 talented Dutch Warmblood dressage horses with stringhalt were injected (maximum of 400 iu per pony and 700 iu per case; 100 iu in 5 ml NaCl divided into 5 injections) with Botox under needle EMG guidance. Surface EMG data were evaluated using customised software, and in the individuals gait was analysed using Proreflex. Statistical analysis was performed using mixed models and independent sample t test (P < 0.05). RESULTS: Surface EMG signals were quantified using customised software. The area under the curve (integrated EMG) in time was used as variable. It became significantly reduced in injected muscles after injection of Botox in normal ponies (P < 0.05). This effect was present from Day 1 until Day 84 after injection. In the 2 cases, after injection of 3 muscles, the integrated EMG in time became significantly reduced in all 3 muscles. Kinematic measurements confirmed reduction of frequency and amplitude of hyperflexing or hyperabducting strides of the affected hindlimbs. The duration of effect was also seen in the cases until around 12 weeks after injection. CONCLUSIONS AND POTENTIAL RELEVANCE: After EMG guided injections of Botox, sEMG signals recorded from injected muscle were reduced, which proves this to be a useful tool in statistically evaluating a treatment effect. The positive results of this pilot study encourage further research with a larger group of clinical cases.

Effects of perennial ryegrass cultivars on milk yield and nitrogen utilization in grazing dairy cows.

The effects of 4 diploid perennial ryegrass cultivars that differed in water-soluble carbohydrate (WSC) concentrations on milk yield and nitrogen (N) utilization in dairy cows were evaluated in a 2-yr grazing experiment. Twelve lactating dairy cows were assigned to 1 cultivar for a 2-wk period in a 4 x 4 Latin square design with 3 replicates. Each year, the experiment lasted 8 wk. Swards were in a vegetative stage throughout the experiment. Herbage constituents were determined, and DM intake was estimated with the n-alkane technique. Nitrogen utilization was calculated as N excreted in milk divided by N intake, assuming a zero N retention. Two cultivars had consistently higher WSC concentrations and slightly lower neutral detergent fiber concentrations than the other 2 cultivars. The ranking of the cultivars in chemical composition traits in both years was rather consistent. Cows grazing the cultivar with the lowest concentration of WSC had the lowest herbage DM intake, N intake, milk yield, and milk N yield in 2002, but with a similar difference in WSC concentration, no differences among cultivars were found in 2003. In both years, milk urea N concentration was slightly higher for cows grazing the cultivar with the lowest WSC concentration, although it was significant only in 2003. Nitrogen utilization (N milk:N intake, g/g) varied between 0.241 and 0.246 in 2002 and between 0.190 and 0.209 in 2003, and in both years there was no effect of cultivar. At relatively high N concentrations in grass and only small differences among cultivars in neutral detergent fiber concentrations, cultivars with an elevated WSC concentration did not increase N utilization in grazing dairy cows.

Effects of perennial ryegrass cultivars on intake, digestibility, and milk yield in dairy cows.

The effects of 8 diploid perennial ryegrass (Lolium perenne L.) cultivars on dry matter (DM) intake, DM digestibility, and milk yield (MY) of dairy cows were evaluated in the summer of 2000 and 2001. Each summer, herbage was harvested daily and stall-fed to 12 dairy cows during six 2-wk periods. Six cultivars were fed in 3 periods (1, 3, and 5) according to a double 3 x 3 Latin square design. In the other periods (2, 4, and 6), 2 cultivars were fed in a repeated measurement design. Herbage mass and leaf blades in the sward canopy varied among cultivars, but differences were not consistent between years. The largest differences in herbage composition were found in water-soluble carbohydrate content, followed by crude protein content. only small differences were found in the neutral detergent fiber (NDF) content. A higher water-soluble carbohydrate content was found in 2 cultivars in both years, whereas ranking of cultivars in crude protein and NDF content was not consistent with years. Dry matter intake and MY were not affected by cultivar. In both years, DM digestiblity was high (>77%), with very small differences among cultivars in 2000 (<0.5%) and larger differences in 2001 (up to 4%). This was associated with a delayed heading date in 2001, resulting in larger differences in leaf blades and NDF content among cultivars. It may be concluded that the 8 cultivars used in our experiments do not provide grass breeders with encouraging evidence to include selection criteria for an increased DM intake, DM digestibility, and MY in their grass breeding schemes.

Comparison of techniques for estimating herbage intake of grazing dairy cows.

For estimating herbage intake during grazing, the traditional sward cutting technique was compared in grazing experiments in 2002 and 2003 with the recently developed n-alkanes technique and with the net energy method. The first method estimates herbage intake by the difference between the herbage mass before and after grazing and the regrowth between the 2 points in time. The second technique estimates herbage intake by the ratio of a dosed even-chain synthetic n-alkane (C32) and a naturally occurring odd-chain n-alkane (C31 or C33) in the herbage and feces. The third technique calculated the intake from the animal's energy requirements for milk production and maintenance. The sward cutting technique estimated herbage intake with the highest coefficient of variation and had different results in the 2 experimental years. The n-alkanes method yielded less variable results, whereas the net energy method gave the least variable results. In 2002, the estimates of the alkane ratio C32:C33 were best related with estimations of the net energy method. In 2003, the estimates of the alkane ratio C32:C31 were best related. The estimate based on the alkane ratio C32:C33 had a lower coefficient of variation than the one based on the alkane ratio C32:C31. Therefore, the C32:C33 alkane method was considered to be a better direct estimator for herbage intake by grazing lactating dairy cows.

Impaired immune response by isoniazid treatment during intravesical BCG administration in the guinea pig.

At present, isoniazid (INH) is being used prophylactically to reduce the side effects of intravesical BCG therapy for superficial bladder cancer, although it is not clear whether or not this reduces the antitumor efficacy of BCG. In this study the impact of INH treatment on the immune response after repeated intravesical BCG administration was investigated in guinea pigs. INH was given on the 3 days around each BCG instillation. We found that the administration of INH severely impaired the immunological effects of BCG. The induction of mononuclear cell infiltration in the bladder wall was reduced. Enlargement of the regional lymph nodes (weight and number of cells), and increase of MHC Class II expression on the lymph node cells, normally observed after intravesical BCG administration, were inhibited by INH. Systemic immunity, measured by the DTH reaction in the skin to PPD, was also diminished due to the combined treatment of BCG with INH. When INH was administered during the last 4 of 6 BCG instillations, the immune response to BCG was still impaired. A five-fold increase of the dose of BCG did not overcome the effect of INH. INH probably did not exert a direct suppression of the immune system of the guinea pig as the DNCB skin reactivity was not influenced. Although INH concentrations in the urine were high at the onset of the instillation, in vitro experiments indicated that the effect of INH may not be caused by killing of the BCG organisms shortly after application in the bladder. In conclusion, our data in guinea pigs suggest that the use of INH may impair the immune response to intravesical BCG. As this response may be important for the antitumor effect of BCG, urologists should be cautious with the prophylactic use of INH. The influence on the antitumor efficacy is now investigated in man.

Tumor infiltrating leukocytes (tils) during progressive tumor growth and BCG-mediated tumor regression.

Tumor regression was induced by intralesional injection with BCG, 7 days after inoculation of line 10 hepatocellular carcinoma cells into strain 2 guinea pigs. Tumor-infiltrating leukocytes (TILS) were characterized immunohistochemically with 11 monoclonal antibodies (MoAbs) during the induction phase of line 10-immunity, and during immune-mediated regression of the tumor, at days 12 and 28 after tumor cell inoculation, respectively. At day 5 after BCG-injection (day 12 after tumor cell inoculation), there were no major differences between the TIL subpopulations of the BCG-treated and untreated tumors. The TILS were mainly T-cells, as identified by MoAbs against Pan T-cells (CT5), T-cytotoxic/suppressor cells (CT6) and T-helper/inducer cells (H155). A limited number of macrophages was also present. However, at day 21 after BCG-treatment (28 days after tumor cell inoculation), the fibrous stroma was increased dramatically in most of the BCG-treated tumors, and as a result, the tumor cell islets were smaller than in control tumors. In the BCG treated tumors, the numbers of T-cells and macrophages were increased. In growing and regressing tumors, MHC class I and II antigens were strongly expressed in TILS and in the tumor stroma. Line 10 tumor cells prior to inoculation expressed no MHC class I or II antigens. In the centers of the tumor islets at days 12 and 28, expression of these antigens was not found. However, MHC class I and II antigens were expressed on tumor cells at sites where they lay close to the fibrous stroma or TILS. This observation was made in progressively growing tumors and was most apparent in BCG-treated tumors.

[Chromosome studies of 300 young Dutch-Friesian and Holstein-Friesian bulls intended for use in artificial insemination]. / Chromosoomonderzoek aan 300 jonge Fries-Hollandse en Holstein-Friesian stieren bestemd voor KI-gebruik.

Three hundred young Dutch Friesian and Holstein-Friesian bulls, kept in the Central Opfokstation (Central Breeding Station) in Terwispel (Friesland), were studied cytogenetically, using conventional staining methods. Structural chromosome aberrations were not observed. Four animals showed XX/XY-chimerism in the lymphocytes, probably caused by the interchange of haemopoietic cells between the male and its female co-twin by placental vascular anastomosis. The number of (iso)chromatid gaps in 25 metaphase plates varied from 0 to 4. Chromosome breaks were not observed. The chimeric bulls and those with (iso)chromatid gaps were not found to show significantly reduced fertility rates.

Thymus independence of eosinophilia induced by a non-parasite antigen.

Eosinophilia is primarily a T-cell-dependent phenomenon, related to helminthic infections. Using a rat model (+/rnu), it has been shown that keyhole limpet hemocyanin (KLH) in complete Freund's adjuvant (CFA) induced blood eosinophilia, but only after pretreatment with cyclophosphamide (CY). CY alone caused an eosinophilopenia which was reversed by CFA or KLH-CFA treatment. Eosinophilia was also induced in congenitally athymic rnu/rnu rats after CY pretreatment and KLH-CFA stimulation, the response being of a similar order as that in +/rnu animals. It is concluded that a non-parasite antigen can induce blood eosinophilia after pretreatment with CY, the response being thymus-independent. This model may be appropriate to study the biological significance of the eosinophil response.

The influence of different immunization pathways on the immunological response in the oral mucosa.

In order to study a possible difference in the induction of local immunological responses in the oral mucosa after different immunization pathways, Wistar rats were immunized with ovalbumin by different routes, (i) via the submandibular lymph nodes, (ii) via the Peyer's patches and (iii) via the hindpad. The local reaction after antigen challenge was compared with the systemic humoral response. To study the local reaction, the homologous antigen was injected in the oral mucosa. This resulted in a delayed type hypersensitivity reaction, being the same in extent and character for all immunization pathways. The humoral response was evaluated by serum antibody production (antiovalbumine IgG). It was shown that the antibody production obtained by immunization via the Peyer's patches was significantly smaller than that in the rats immunized via other pathways. The conclusion was that the induction of a local cellular reaction was independent of the antigen pathway, whereas serum antibody production depended on the route, i.e. antigen administration via the submandibular lymph nodes and the hindpad was significantly higher than via the Peyer's patches. The possible consequences of the findings are discussed together with their relevance to immunopathological reactions in the oral cavity.

[Immunologic defense and inflammation in parasitic infections. The role of eosinophilic granulocytes]. / Immunologische afweer en ontsteking bij parasitaire infecties. De rol van de eosinofiele granulocyt.

The origin, kinetics and role of eosinophilic granulocytes in immune defense and inflammatory response in parasitism are reviewed. Particular attention was paid to the toxic action of eosinophilic granulocytes on parasites and the biochemical reactions which are of importance in these cases. Reference was also made to the regulatory role of eosinophilic granulocytes in inflammatory reactions, particularly in regard to mast cells. It was concluded that (1) several new insights into the role of eosinophilic granulocytes were gained in recent years, (2) that these cells can at any rate be said to have a dual function (viz. a directly parasitotoxic and regulatory role) and (3) a definite statement regarding the role of eosinophilic granulocytes in helminthic infections cannot so far be made.

The athymic nude rat. IV. Immunocytochemical study to detect T-cells, and immunological and histopathological reactions against Trichinella spiralis.

The anti-parasite response was investigated after oral infection of athymic nude (rnu/rnu) rats and heterozygous (+/rnu) littermates with 1000 muscle larvae of Trichinella spiralis. No IgM, IgG and IgE antibodies were detected in serum of rnu/rnu rats. Expulsion of adult worms from the small intestine was prolonged (worms were nearly all expelled at days 14 and 91 in +/rnu and rnu/rnu rats respectively). The yield of muscle larvae in the carcasses of nude rats at day 91 was 33 times higher than in +/rnu rats. In contrast to the strong inflammatory reaction in the parasitized tongue of +/rnu rats, no infiltration was observed in rnu/rnu rats. Using an immunoperoxide method with monoclonal anti-rat T-cell antibody, no T cells were identified in spleen, mesenteric lymph node and Peyer's patches. These data support earlier studies that the nude rat lacks functional T cells. As the counts of connective tissue mast cells (CTMC), intestinal mast cells (IMC) and globule leucocytes (GL) in small intestine of uninfected rnu/rnu rats were equal or higher than in +/rnu rats, it is concluded that the origin of these cells is thymus-independent. In contrast to +/rnu rats, infection of rnu/rnu rats induced no increase of CTMC, IMC or GL. Thus, these cells depend on T cells to undergo proliferation. Finally, results of this study were inconclusive whether IMC are precursors for GL, or that they represent independent cell populations.

[Immunology - results of two decades of immunological research]. / Immunologie - oogst van twee decennia immunologisch onderzoek.

The discipline of immunology has made very rapid progress during the past twenty years. A general introductory part was followed by a discussion of immunological components in resistance. Subsequently, the importance of controlling the immunological system was stressed. The significance of the network theory was briefly referred to. Attention was then drawn to specific and non-specific stimulation of the immune response, which are essential both in theory and in actual practice. A number of instances are cited to illustrate these features in recent developments in the fields of preparation of vaccines and immunological treatment of cancer. It was pointed out that, during the past decades, the discipline of immunology not only made great strides in the field of human medicine and experimental animal models associated with this branch of medicine but also in that of veterinary medicine. It was predicted that immunology would also continue to be essential in the diagnosis, treatment and prevention of disease in animals.

Increase of mucosal mast cells in the jejunum of patients infected with Trichinella spiralis.

The mast cell response in the mucosa and connective tissue of 36 jejunal biopsies of patients with clinically diagnosed trichinellosis, teniasis and lambliasis has been studied. Biopsy material was fixed in standard formalin or Carnoy's fixative, enabling differentiation between mucosal mast cells (MMC) and connective tissue mast cells (CTMC). With both fixatives CTMC could equally well be recognized. With Carnoy's fixative an additional population of mast cells (MMC) could be visualized both in the mucosa and the connective tissue. In the mucosa small mucosal mast cells were observed as well. Compared to the numbers of mast cells in the mucosa and the connective tissue of teniasis and lambliasis patients, the number of mast cells in trichinellosis patients only visualized using Carnoy's fixative was markedly higher. It was concluded that also in man trichinellosis is accompanied by an increase of cells with MMC characteristics. Further studies are needed to clarify the morphological and histochemical features of these cells and their possible role in this parasitic infection.

Rat mononuclear cells and neutrophils are more effective than eosinophils in antibody-mediated stage-specific killing of Trichinella spiralis in vitro.

The capacity of non-infected rat total, eosinophil-enriched and eosinophil-depleted fractions of peritoneal exudate and bone marrow cells to adhere to and kill Trichinella spiralis newborn larvae with immune rat serum has been studied in vitro. The eosinophil-depleted peritoneal exudate cell fraction contained mainly mononuclear cells, whereas the corresponding bone marrow cell fraction consisted of a considerable number of neutrophils. All cell types either originating from the peritoneal cavity or the bone marrow, showed adherence and killing properties to the Trichinella newborn larvae. It was concluded that mononuclear cells and neutrophils are capable of and more effective than eosinophils in stage-specific killing of Trichinella in vitro.