Integration of e-learning resources into a medical school curriculum.

BACKGROUND: E-learning has the potential to make important contributions to medical education, but there has been limited study of a blended approach in which the digital resources are introduced alongside traditional teaching methods such as lectures. METHODS: We describe the successful embedding of an e-learning resource into 3 of the 5 weeks of cardiovascular system teaching for 164 first-year medical students by providing scheduled slots in the timetables. A questionnaire completed by the students at the end of the 5 weeks had a response rate of 66%. Students varied in how they made use of the resource, some systematically working through it and others browsing and studying sections felt to be personally most relevant. RESULTS: Almost all (96%) rated the e-learning resources as probably or definitely of value: they particularly valued interactive activities, animations, video demonstrations, video clips of experts and self-assessment exercises. Graduate students had a significantly more favourable assessment of the e-learning resources than their undergraduate colleagues, while female students felt the value in supporting existing learning opportunities more strongly than male students. CONCLUSIONS: It should not be assumed that all students will choose to use an e-learning resource in the same way and instructional design should enable alternative approaches. The sequence in which the e-learning resource is used in relation to the other learning opportunities, such as lectures and PBL group discussions, may be important and merits further consideration. The experiences reported in this study provide encouragement and pointers for others engaged in the integration of e-learning in their curriculum.

The effect of mixed or sequential grazing of cattle and sheep on the faecal egg counts and growth rates of weaned lambs when treated with anthelmintics.

An experiment was conducted over two successive years (2002 and 2003) to investigate the effects of grazing improved permanent pasture (mainly perennial ryegrass/white clover) by cattle or sheep, either sequentially or mixed, on the faecal egg counts and growth rates of weaned lambs when treated with anthelmintics. The grazing season was divided into two parts, May-July then July-October, relating to the pre- and post-weaning of the lambs. Four grazing regimes, replicated three times, were compared: (1) sheep only from May to October (SS); (2) cattle May to July followed by lambs until October (C/S); (3) cattle and sheep May to July followed by lambs until October (C+S/S); and (4) cattle and sheep May to July followed by cattle and lambs until October (C+S/C+S). Sward height was maintained at 6 cm using a "put and take" stocking system. At weaning, lambs were weighed and treated with an anthelmintic (0.08% ivermectin drench, Oramec) before being allocated to plots. They were then weighed and drenched every 28 days until the end of the experiment (Day 84). Faecal egg counts (FEC) were measured in all lambs immediately prior to each anthelmintic treatment. In 2002 and 2003, there were differences between the groups in FEC, with the SS lambs having the highest values and C/S lambs the lowest (P<0.01). There were also differences in the rate of liveweight gain of the lambs in each of the study years: for this parameter SS lambs had the lowest growth rate but the fastest growth was in C+S/C+S lambs not C/S lambs (P<0.01), indicating that these differences were due to factors other than parasite infection. Overall, sequential grazing of pastures with cattle then sheep reduced the faecal egg counts in lambs regularly treated with anthelmintics when compared with lambs grazing in mixed systems with cattle and sheep or with sheep only systems, however, the highest growth rates were observed in lambs in the mixed cattle/sheep grazing system throughout.

[Isolation and characterization of the ALP1 protease from Aspergillus fumigatus and its protein inhibitor from Physarium polycephalum].

It is known that Aspergillus fumigatus secretes a serine protease ALP1 of the subtilisin family in the presence of extracellular protein substrates. We found conditions of A. fumigatus culturing that provide a high ALP1 activity inside cells without induction by extracellular proteins. The identity of the properties of the secreted and intracellular enzymes was shown. A thermostable protein inhibitor of the ALP1 protease was isolated from the plasmodium of the myxomycete Physarum polycephalum. Its molecular mass is 32-33 kDa. The inhibitor inhibits the ALP1 protease activity with IC50 of 0.14 microM. This protein was also shown to be a less efficient inhibitor of the activity of HIV-1 protease (IC50 2.5 microM). The English version of the paper: Russian Journal of Bioorganic Chemistry, 2005, vol. 31, no. 3; see also http://www.maik.ru.

Systemic haemostasis after intermittent pneumatic compression. Clues for the investigation of DVT prophylaxis and travellers thrombosis.

Intermittent pneumatic compression (IPC) is known to provide effective prophylaxis against post-surgical deep-vein thrombosis (DVT), and other procedures based on reducing venous stasis have been promoted recently to minimize the risk of thromboembolism after long-haul travel ('travellers thrombosis'). This study sought to measure the effects of IPC on systemic haemostasis, which are currently disputed. IPC was applied for 120 min on 21 male, non-smoking volunteers ranging in age from 19 to 47 years. IPC promoted a significant increase in global fibrinolytic potential. Levels of urokinase plasminogen activator activity (uPA) measured using an amidolytic assay were raised after IPC. However, enzyme-linked immunosorbent assays (ELISA) of uPA antigen, and the activities of tissue plasminogen activator (tPA) and plasminogen activator inhibitor 1 (PAI-1) were not statistically different from those in control experiments. IPC led to highly significant falls in factor VIIa, associated with increased levels of tissue factor pathway inhibitor (TFPI). IPC enhances fibrinolysis and suppresses procoagulant activation. Measurements of specific fibrinolytic components do not reflect overall fibrinolytic activity and are highly dependent on the method of assay. The results provide important clues for detailed studies of the effects of haemodynamics on systemic haemostasis.

Novel seven coordination geometry of Sn(IV): crystal structures of phthalocyaninato bis(undecylcarboxylato)Sn(IV), its Si(IV) analogue, and phthalocyaninato bis(chloro)silicon(IV). The electrochemistry of the Si(IV) analogue and related compounds.

Three newly elucidated crystal structures of group IV phthalocyaninato complexes are reported, along with data for two further SiPc carboxylate complexes. In one of these crystal structures, bis(undecylcarboxylate)Sn(IV) phthalocyanine, the tin ion is seven coordinate, which is a unique finding for this atom in phthalocyanine ring coordination. Comparison of these structures with other group IV phthalocyaninato and related structures reveals differences, illustrating features significant in the chemistries of Si(IV) and Sn(IV) ions. These differences are thought to originate from their differing sizes and polarizabilities. The structures show that the Sn(IV) ion can only occupy an in-plane location in the phthalocyaninato ring where it elongates toward the two axial ligands. When the axial ligands do not facilitate this elongation cis coordination is preferred and the Sn(IV) ion sits above the phthalocyaninato ring plane. In contrast, the Si(IV) structures, with smaller, harder (i.e., less polarizable) Si(IV) ions, are six coordinate with the Si(IV) ion in the phthalocyaninato ring plane in a distorted octahedral symmetry. The electronic spectra and cyclic voltammetry of some of the Si compounds indicate that on the electrode the oxidized/reduced species behave as though they are in a solid film, rather than a soluble freely diffusing species.

Influence of the number of days spent training in an abattoir with access to live cows on the efficiency of do-it-yourself artificial insemination.

Data relating to 35,389 inseminations carried out in the first three years after inseminators were trained were collected by postal questionnaire from 94 do-it-yourself (DIY) artificial inseminators in the UK. The mean calving rate from 14,528 inseminations they carried out on 92 farms in the first year after they were trained was 59.4 per cent (range 5 to 92 per cent). In the second year the mean calving rate from 11,515 inseminations by 64 inseminators was 62.3 per cent (range 33 to 88 per cent), and in the third year the mean calving rate from 9346 inseminations by 49 inseminators was 64.6 per cent (range 41 to 92 per cent). There was an increase of 5.2 per cent in the mean calving rate over the three years with an overall mean calving rate of 61.5 per cent. Each trainee carried out an average of 376 inseminations (range 20 to 800) during the three years. Thirteen instructors were responsible for the tuition and the average time the trainees spent in an abattoir with access to live cows was 2.88 days, with a range from none to five days. For the trainees who spent up to three days training in an abattoir there was an increase of 5.9 per cent in the calving rate they achieved in their first year for every day they spent training with access to live cows (P < 0.005), but there were no significant effects on the outcome of their inseminations in their second or third years.

Norgestomet implants, plasma progesterone concentrations and embryo transfer pregnancy rates in cattle.

A study was undertaken to test the hypothesis that supplementation with exogenous progestagen at the time of embryo transfer would enhance pregnancy rates in recipients. Two-hundred-and-seventy-two oestrus-synchronised crossbred heifer and cow recipients received 200 grade 1 and 72 grade 2 Simmental embryos transferred non-surgically. Heparinised blood samples were taken on day 6 and day 7 (oestrus = day 0) for the assessment of the endogenous plasma progesterone concentration. Half the recipients received an ear implant impregnated with 3 mg norgestomet on the day of embryo transfer. The pregnancy rates were 51.9 and 49.6 per cent for the norgestomet-treated and control groups, respectively. The pregnancy rate for grade 1 embryos was 56.0 per cent and for grade 2 embryos 36.1 per cent (P < 0.01). The breed of recipient, weekday of transfer, operator and condition score had no effect on pregnancy rate. The maiden heifers had a higher pregnancy rate (54.2 per cent) than the cows (46.2 per cent). The mean plasma progesterone concentrations of the pregnant and non-pregnant groups on day 6 were 6.7 ng/ml and 6.6 ng/ml, respectively, and 7.6 ng/ml in both groups on day 7.

Arthroscopic portals: the importance of blade selection.

Arthroscopy of the knee is a commonly performed procedure with a low reported complication rate. We have experienced two cases during which no. 15 scalpel blades disengaged from the handle and remained within the joint. Although both the blades were successfully retrieved arthroscopically without injury to the knee, the procedures were prolonged, and there remained a potential risk of causing damage. We have subsequently altered our practice and now routinely use a no. 11 blade, with which we have had no complications. We discuss the importance of correct blade selection and surgical technique in avoiding this complication and present two illustrative case histories.

Management aspects of induced twinning in beef suckler cows using in vitro fertilised embryos.

Twin and single pregnancies were induced in two groups of oestrus-synchronised beef cows by using a combination of artificial insemination and the transfer of in vitro fertilised (IVF) embryos. Single IVF embryos transferred non-surgically to the uterine horn contralateral to the corpus luteum of 43 previously inseminated cows resulted in a calving rate of 72 per cent with a twinning rate of 38.7 per cent. In 45 cows, two IVF embryos were transferred non-surgically to one uterine horn resulting in a calving rate of 51.1 per cent with a twinning rate of 39.1 per cent. The median gestation length for cows bearing twins was 10 days shorter than that of cows bearing single calves (P < 0.001). The proportions of cows that received assistance at calving were similar for twin and single births (57 per cent vs 45 per cent, P > 0.05), but the incidence of retained fetal membranes was much higher after the birth of twins (62 per cent vs 3 per cent, P < 0.001). Nineteen per cent of twin calves were stillborn compared with 6 per cent of single calves (P > 0.05). The median birthweight of the twin calves was 32 kg (68 per cent of the median weight of single calves). The nutrition of twin-bearing cows in late pregnancy was adequate when assessed in terms of their plasma glucose, non-esterified fatty acid and beta-hydroxybutyrate concentrations. Serum immunoglobulin concentrations were similar in single and twin calves suggesting that the passive transfer of antibody was not compromised in the twin calves.

ACTH (4-10) increases quantal content at the mouse neuromuscular junction.

Adrenocorticotropic hormone 4-10 (ACTH 4-10), in concentrations of 50 nM and 1 microM, increased both the frequency of miniature endplate potentials and the amplitude of the endplate potentials in addition to decreasing the number of failures following stimulation of the phrenic nerve in the mouse in vitro. There was no effect of the peptide on either the amplitude of the miniature endplate potentials or the resting membrane potential of the muscle fibres. These results indicate that the action of ACTH 4-10 was to increase the quantal content of the endplate potential via a presynaptic action.

Three-wavelength device for all-optical signal processing.

We describe the operation of a semiconductor laser amplifier as a nonlinear element, using a novel three-wavelength configuration, which enhances the recovery rate of the nonlinear refractive index and permits choice of its sign and magnitude. Simple rate-equation analysis suggests that 100-GHz operation should be possible with powers of ~1 W.

Development of an endocrine challenge test to investigate subfertility in ewes.

Simultaneous or sequential injection of 250 ng gonadotrophin releasing hormone (GnRH) and 25 micrograms oestradiol benzoate, with luteinizing hormone (LH) measurements at 0, +20 min (after GnRH) and +16 h (after oestradiol), enabled investigation of the positive feedback effects on the hypothalamus and pituitary. Control ewes had pretreatment LH values of 3.1 +/- 1.2 ng/ml with an increment of 3.2 +/- 2.3 ng/ml 20 min after GnRH. Subfertile ewes, in spite of elevated pretreatment LH concentrations (15.8 +/- 9.5 ng/ml) in eight out of 10 ewes, had increments of 1.4-84 ng/ml after GnRH. Control ewes had LH increments of 3-75 ng/ml 16 h after oestradiol. Subfertile ewes with pretreatment LH concentrations less than 15 ng/ml also responded to oestradiol whereas those with initial LH concentrations 16-40 ng/ml had no further LH increment. Subsequent administration of 1000 iu pregnant mares' serum gonadotrophin (PMSG), with measurement of LH and oestradiol at 0, +24, +30, +48, +54, and +72 h, allowed assessment of ovarian response and hypothalamus-pituitary function. Five control ewes were sampled up to 30 h post-PMSG and only 1 had oestradiol concentrations greater than 10 pg/ml. Sampling up to 72 h in another five control ewes resulted in oestradiol concentrations greater than 10 pg/ml. Increments in LH concentration greater than 3 ng/ml were recorded in control and subfertile ewes with oestradiol concentrations greater than 10 pg/ml. The use of these endocrine challenge tests enabled positive diagnosis of abnormality on 8 out of 10 occasions.(ABSTRACT TRUNCATED AT 250 WORDS)

Practical uses of ultrasound in early pregnancy in cattle.

Using a 'real-time' ultrasound scanner with a 3.5 MHz rectal transducer, a herd of 80 Friesian cows were scanned at weekly intervals during early pregnancy to assess the accuracy of pregnancy diagnosis, and the accuracy of twin detection. The growing fetuses were also measured to determine the relationship between crown-rump length and age. The accuracy of detection of pregnancy was inversely proportional to the age of the cow (r -0.967), the accuracy of detection of twinning was 100 per cent and there was strong correlation between fetal crown-rump length and age (r 0.98).

Specific transfer factor protects mice against lethal challenge with herpes simplex virus.

Bovine transfer factor (TFd) specific to herpes simplex virus (HSV)1 or to HSV2 was prepared by immunizing calves with the corresponding virus. The TFd preparations were then injected into Swiss mice in an attempt to protect them against a subsequent lethal challenge with HSV1 or HSV2 virus. It was thus shown that injection of anti-HSV TFd protects the mice against the corresponding HSV virus, whereas the injection of a nonspecific TFd (anti-CMV) fails to protect against a challenge with HSV1. Furthermore, a dose-response effect was observed, since potent TFd preparations were ineffective when they were used at one-fifth of the original concentration. It seems, therefore, that animal models may be used to assay the potency of TFd preparations specific for herpes viruses.

Only B lymphocytes induce active enhancement of rat cardiac allografts.

LEW rats were immunized 7 days before (LEW X BN)F1 heart transplantation with 10(7) BN donor cells, either purified erythrocytes (RBC), peripheral blood (PBL), splenic, nylon-wool-adherent (B-enriched) or nylon-wool-nonadherent (T-enriched) lymphocytes. Allograft rejection was only significantly enhanced in animals pretreated with lymphocyte populations containing surface immunoglobulin (SIgG)-positive cells (PBL, splenic, or B-enriched lymphocytes). Recipients immunized with RBC or T-enriched lymphocytes containing few, if any, SIgG-bearing B lymphocytes showed no significant graft prolongation.

The influence of carbohydrases on the growth of fungal pathogens in vitro and in vivo.

Mixtures of mycolytic enzymes from various sources release protoplasts from living fungal tissue under suitable conditions. Such enzyme mixtures obtained from Coprinus comatus (mycolase I), Physarum polycephalum (mycolase II) and Lycoperdon pyriforme (mycolase III) are of low toxicity in mammals when given parenterally and are able to cure experimental systemic fungal infections in mice when administered alone or in conjunction with normally ineffective levels of conventional antimycotic drugs such as amphotericin B. The effect is believed to be due to enzymic degradation of the fungal cell wall either killing the fungus directly or enhancing activity of existing antifungal agents by increasing access to the cell interior.