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ObjectiveStudies of patient safety in health care have traditionally focused on hospital medicine. However, recent years have seen more research located in primary care settings which have different features compared to secondary care. This study set out to synthesize published qualitative research concerning patient safety in primary care in order to build a conceptual model.MethodMeta-ethnography, an interpretive synthesis method whereby third order interpretations are produced that best describe the groups of findings contained in the reports of primary studies.ResultsForty-eight studies were included as 5 discrete subsets where the findings were translated into one another: patients' perspectives of safety, staff perspectives of safety, medication safety, systems or organisational issues and the primary/secondary care interface. The studies were focused predominantly on issues seen to either improve or compromise patient safety. These issues related to the characteristics or behaviour of patients, staff or clinical systems and interactions between staff, patients and staff, or people and systems. Electronic health records, protocols and guidelines could be seen to both degrade and improve patient safety in different circumstances. A conceptual reading of the studies pointed to patient safety as a subjective feeling or judgement grounded in moral views and with potentially hidden psychological consequences affecting care processes and relationships. The main threats to safety appeared to derive from 'grand' systems issues, for example involving service accessibility, resources or working hours which may not be amenable to effective intervention by individual practices or health workers, especially in the context of a public health system.ConclusionOverall, the findings underline the human elements in patient safety primary health care. The key to patient safety lies in effective face-to-face communication between patients and health care staff or between the different staff involved in the care of an individual patient. Electronic systems can compromise safety when they override the opportunities for face-to-face communication. The circumstances under which guidelines or protocols are seen to either compromise or improve patient safety needs further investigation.

Background: The duplication of autosomal genes onto the Y chromosome may be an important element in the evolution of sexual dimorphism. A previous cytological study reported on a putative example of such a duplication event in a dioecious tribe of Silene (Caryophyllaceae): it was inferred that the Y-linked MADS-box gene AP3Y originated from a duplication of the reportedly autosomal ortholog AP3A. However, a recent study, also using cytological methods, indicated that AP3A is X-linked in Silene latifolia., Methodology/principal Findings: In this study, we hybridized S. latifolia and S. dioica to investigate whether the pattern of X linkage is consistent among distinct populations, occurs in both species, and is robust to genetic methods. We found inheritance patterns indicative of X linkage of AP3A in widely distributed populations of both species., Conclusions/significance: X linkage of AP3A and Y linkage of AP3Y in both species indicates that the genes' ancestral progenitor resided on the autosomes that gave rise to the sex chromosomes and that neither gene has moved between chromosomes since species divergence. Consequently, our results do not support the contention that inter-chromosomal gene transfer occurred in the evolution of SlAP3Y from SlAP3A.

Stone chewing is a common behaviour in outdoor sows, but its effects on their teeth and stomachs have not been investigated. Tooth wear and damage was assessed by examining the heads of 58 sows culled from outdoor units and 23 culled from indoor units. Tooth damage was found in 28 per cent of outdoor and 30 per cent of the indoor sows, and tooth wear affected 88 per cent of the outdoor and 91 per cent of the indoor sows. The outdoor sows were more prone to wear on the lower molars and premolars, a pattern of wear associated with stone chewing. The stomachs of 152 outdoor sows and 47 indoor sows were examined. Stones were found in 59 of the outdoor sows but in none of those kept indoors. There was no evidence that the presence of stones damaged the stomach, or that stone chewing affected the health of the sows. The teeth of the outdoor sows were worn, but probably not sufficiently to affect their ability to eat during their relatively short productive lives.

The tail length (docked, tipped or undocked) and tail status (bitten or unbitten) of 27,870 pigs from 450 units was recorded at six UK abattoirs. A farm survey of the final finishing stage was used to investigate the relationship between management practice and tail biting. This showed that docking was the most important factor influencing the probability of being not bitten, with 2.4% of docked and 8.5% of long-tailed pigs being tail-bitten. The following factors reduced the probability of long-tailed pigs being tail-bitten; light straw provision, use of natural ventilation or artificially controlled natural ventilation (ACNV), mixed sex grouping, meal or liquid feeding, and use of double or multi-space feeders. Docked and long-tailed pigs provided with light straw and natural ventilation/ACNV had levels of tail biting of 1.2% and 4.3% respectively; 3.9% of docked pigs with artificial ventilation and no straw were tail-bitten. Long-tailed pigs fed via double or multi-space feeders also had 3.9% of tails bitten., (Copyright 2001 Harcourt Publishers Ltd.)

In an abattoir survey the stomachs of 1242 pigs from 15 farms were examined. Ulceration of the pars oesophagea was present in 22.95 per cent with a range from 4.7 to 57.4 per cent. The ulcers were graded mild in 9.5 per cent and severe in 13.4 per cent of the stomachs. Bile staining and hyperkeratinisation of the pars were significantly more common in stomachs with ulcers than in those without (P < 0.001), although the difference between the hyperkeratinisation in cases with severe ulcers and cases without ulcers was not significant. The daily liveweight gains of 208 males and 150 females from two units with a high prevalence of ulcers were calculated from their weaning weights at about five weeks of age and their slaughter weights at around 90 kg. At the abattoir their stomachs were examined for the presence of ulcers of the pars. The daily liveweight gain of the males was significantly greater than that of the females (P < 0.001), but the presence of mild or severe ulcers had no influence on the rate of gain of the pigs from either unit. The prevalence of ulcers in the males and females was 57.2 and 49.3 per cent, respectively, but the difference was not significant.

From 15 farms, 1242 pigs (range per farm 12-169) were sent for slaughter at known times after their last feed. The time of feeding, quantity and type of last feed, time of loading, time in transit, distance travelled, time in lairage and time of slaughter, were recorded. The mean +/- SD stomach weight and wet stomach contents weight were 0.68 +/- 0.12 and 0.55 +/- 0.45 kg, respectively. There were 148 stomachs (11.9%) with wet contents weights > 1 kg, nine > 2 kg but < 3 kg, and one weighed 3.04 kg. The means and ranges for times from last feed to loading interval, time in transport, and time in lairage were 13.6 (0-40), 3.1 (0.75-6.0) and 4.1 (2.1-12.5) h, respectively. The mean and range for distance travelled was 193.1 (43-320) km. Ten stomachs were collected at random from a further load of pigs from one farm. They had been fed 0.64 kg dry pellets and were slaughtered 18.5 h later. The mean and range for wet stomach contents weight was 0.87 kg (0.24-1.33). Samples were dehydrated and the mean calculated stomach dry matter content for the 10 pigs was 127.4 +/- 69.1 g.

Pigs from four farms (two producing 'easy' and two 'difficult to handle' pigs) were slaughtered at two abattoirs, each with two slaughter handling systems, so that 25 pigs of each behavioural type were slaughtered by all four handling systems on each day; there were 16 replicates (3200 pigs) in total. The pigs at abattoir X were electrically stunned, either in a floor pen holding five pigs or in a race-restrainer. At abattoir Y the pigs were stunned either in a floor pen holding five pigs or in a dip-lift carbon dioxide stunner. The following measurements were made: hot carcase weight and backfat thickness at P2, degree of rigor mortis 35 minutes post mortem, skin blemish, pH and muscle reflectance in the m longissimus dorsi at 60 minutes and 18 hours post mortem, and pH and muscle reflectance in the m adductor at 18 hours post mortem. At abattoir X, the pigs slaughtered in the race-restrainer had heavier carcases (74.0 kg vs 73.0 kg, P < 0.05), developed rigor mortis more rapidly (8.1 mm vs 7.3 mm, P < 0.01), had more skin blemish (2.8 vs 2.7, P < 0.01), paler m longissimus dorsi muscles after one hour (15.7 vs 13.9, P < 0.01) and 18 hours (27.8 vs 26.6, P < 0.05), and paler m adductor muscles (24.5 vs 22.7, P < 0.001) after 18 hours. At abattoir Y, the pigs handled through the floor pen system had more skin blemish (2.7 vs 2.6, P < 0.05) and a tendency to develop rigor mortis more quickly (6.11 vs 5.32, P = 0.089).(ABSTRACT TRUNCATED AT 250 WORDS)

The effects of feeding the beta-adrenergic agonist salbutamol to pigs at levels between 0.5 and 5.0 mg/kg feed for different periods were studied in six experiments. The feet and ability to walk of pigs weighing 30 to 100 kg were examined at intervals. False sand-crack, white-line and heel erosion lesions were classified as mild or severe, and corns and wall haemorrhages were also recorded. At each examination the pig was given a grade for the overall severity of its foot lesions. Salbutamol fed at 1.0 to 5.0 mg/kg feed, for as little as 21 to 28 days, increased the frequency (P < 0.05 to 0.001) and often the severity (P < 0.05) of the foot lesions, the higher doses tending to produce more severe lesions, and the overall foot grades deteriorated (P < 0.001). The effects on both sexes were similar. No changes were observed when 0.5 mg/kg was fed for 56 days. Despite the severity of many of the foot lesions, the pigs became lame in only one experiment. Electron microscopy indicated that salbutamol was interfering with horn production, but light microscopy revealed no changes in skin sections. These findings suggested that salbutamol was not directly affecting the function of keratinocytes. Supplementing the diet of the pigs with biotin and methionine did not delay, or prevent, the effects of salbutamol.

Pigs from four farms were slaughtered at two abattoirs, each with two slaughter handling systems. Pigs at abattoir X were electrically stunned, either in a floor pen holding five pigs or in a race-restrainer. At abattoir Y pigs were stunned either in a floor pen holding five pigs or in a dip-lift carbon dioxide stunner. At exsanguination, 96 blood samples (24/farm) were collected from pigs slaughtered through each slaughter handling system (384 samples in total). Serum samples were analysed for cortisol, creatine phosphokinase (CPK) lactate dehydrogenase (LDH) and LDH-isoenzymes. There were no significant differences between the systems at abattoir X. At abattoir Y, pigs slaughtered through the floor pen system had higher levels of LDH-5 (39.84 +/- 1.39 per cent of total LDH vs 34.76 +/- 1.21 per cent, P < 0.05) indicating greater skeletal muscle damage in the floor pen. Pigs at abattoir Y had higher mean serum levels of CPK than pigs at abattoir X (3.63 log10 U/litre vs 3.41 log10 U/litre, 0.03 sed, P < 0.001), higher total LDH activities (1269.5 U/litre vs 922.8 U/litre, P < 0.001) and higher cortisol concentrations (1.70 log10 ng/ml vs 1.51 log10 ng/ml, P < 0.001). These differences suggested that the levels of physical and psychological stress were higher at abattoir Y.

On eight farms alternate sows and gilts within three weeks of their expected farrowing date were injected intramuscularly in the neck with 8 ml of an iron (gleptoferron) preparation containing 200 mg iron/ml, or kept as uninjected controls. Data from 513 iron-injected and 488 control animals were used in the analysis of results. Small, but not statistically significant, improvements were observed in the numbers of piglets born alive and dead/litter, the birth weights and weaning weights at three weeks, the numbers of piglets fostered on and off/litter, piglet mortality, the number weaned/litter and the weaning to service interval. The condition scores of the iron-injected sows were marginally below those of the controls at weaning, but their condition scores at farrowing had also been slightly below those of the controls. A summation of these trends would suggest an overall benefit of approximately 0.45 pigs/sow/year in favour of the iron-injected sows.

A herd of 116 sows was divided into two groups. Animals in one group had their food supplemented with 1160 micrograms/day of biotin in pregnancy and 2320 micrograms/day in lactation, over a 12-month period. The other group served as a control. Those receiving biotin farrowed significantly more live pigs in parities 2 and 4 than in the control animals; the increase in parity 3 only just failed to reach significance. There was no consistent effect on the weaning to service internal although a significant difference (P = 0.05) was seen with the third litters.

1. Verruculogen is eliminated in bile after transformation to TR-2, only a trace of which was excreted as such in faeces of sheep given verruculogen per os. Negligible TR-2 was present free in urine; no glucuronide was found. 2. An isomer of TR-2, a minor component of the bile of sheep given verruculogen, has been defined by 1H-n.m.r. spectroscopy and the isomerism involves the disposition of the two adjacent hydroxyl groups with a concomitant change in the conformation of the ring adjacent to the indole. 3. 14C-TR-2, added to the perfusate of isolated rat liver, was excreted unchanged in the bile, implying no significant loss of any biliary TR-2 subject to enterohepatic recycling in vivo. 4. 14C-TR-2 incubated anaerobically in sheep ileum contents was 95% transformed into more polar metabolites, the majority of the radiolabelled metabolites isolated being water soluble. 5. The principal fate of biliary TR-2 is as a metabolic substrate for the intestinal microflora.

A herd of 116 sows with a high frequency of foot lesions and lameness was divided into two groups, A and B. Group B was supplemented with 1160 microgram per day of biotin in pregnancy and 2320 microgram per day in lactation, over a 12-month period. No improvement occurred in the condition of the feet or skin. Gilts introduced as replacements to the herd were allocated alternately to the groups. Those receiving biotin (group B) showed significantly fewer lesions of heel erosion, white-line, heel bruising and "corn", and the severity and number of lesions of the lateral hind claws were also significantly improved.

The myelograms of adult guinea-pigs at various stages after brief exposure to hyperthermia were compared with those of control animals. The proportions of neutrophil and eosinophil metamyelocytes and of intermediate normoblasts were significantly reduced for at least 24 h after exposure and the proportions of neutrophil polymorphs and lobulated eosinophils were significantly increased over this period. The mitotic index was reduced for up to 5 h. Morphological changes in cells included hypersegmentation of nuclei, pyknosis, necrobiotic changes, development of pseudopodia, and abnormalities of mitosis. The myelograms of newborn guinea-pigs which had been heated on days 20-23 of pregnancy showed no significant changes.

Exposure of pregnant guinea pigs to an environmental temperature of 42 degrees C for 1 hr daily on Days 20-24 of gestation resulted in a significant reduction in the birthweight and brainweight of newborn offspring. These deficits persisted to early maturity and were still evident at 250 days of age following behavioral testing. Although some degree of postnatal neurogenesis and brain growth had occurred, this was not sufficient to compensate for the retarding influence of prenatal hyperthermia. Heat stress was also observed to seriously impair learning performance on the original discrimination task and this tendency persisted over the subsequent 4 reversals for both initial and perseverative errors. Impaired learning performance was related to reduction in brainweight. Animals with lower brainweights made significantly more initial, perseverative and total number of errors over the 5 problems. In addition, 12 of the 14 behaviorally tested stressed progeny had brainweights that were at least 2 standard deviations below the mean of the controls and as a result were classified as micrencephalic. Although heat stressed animals showed a significant reduction in the number of amacrine synapses in the inner plexiform layer of the retina, performance differences were not atrributed to changes in synaptic organisation of the retinal circuitry or to visual or other ophthalmic defects, but brain function. Animals with higher mean maternal poststressing core temperatures gave birth to progeny which had smaller whole and part wet-brainweights. Examination of the effect of poststressing core temperature on brainweight revealed that brain growth, independent of bodyweight, was retarded when this temperature elevated above 41.5 degrees C. This represented a rise of approximately 2.1 degrees C above normal and for each 1 degree C rise above this temperature, brainweight was reduced by 0.4227 g of the control value. Analysis of the atmospheric content of the incubator during stressing sessions ruled out the possibility that changes in level of oxygen and carbon dioxide may have contributed to the retarding influence on fetal development and learning ability in the guinea pig.

The growth and wear rate of claw horn was measured in 42 commercial hybrid pigs. Half received a ration supplemented with 1 mg d-biotin/kg food daily, while the others acted as controls. The start weights of three replicates of 10 pigs averaged 25 kg and their mean finishing weight was 85 kg. Twelve pigs averaged 18 kg at the start and 118 kg at the end of the experiment. No differences in horn growth and wear rates were found between the biotin-supplemented pigs and the controls, or between the front and hind claws, although horn growth and wear both decreased with age. Claw horn grew at an average of 10 mm/28 days in the pigs taken from 25 to 85 kg bodyweight and at 11 mm/28 days in the pigs taken from 18 to 118 kg. The mean rate of wear of claw horn was 6 mm/28 days.

The neurochemical effects of the tremorgenic mycotoxins Verruculogen and Penitrem A, which produce a neurotoxic syndrome characterised by sustained tremors, were studied using sheep and rat synaptosomes. The toxins were administered in vivo, either by chronic feeding (sheep) or intraperitoneal injection 45 min prior to killing (rat), and synaptosomes were subsequently prepared from cerebrocortical and spinal cord/medullary regions of rat, and corpus striatum of sheep. Penitrem A (400 mg mycelium/kg) increased the spontaneous release of endogenous glutamate, GABA (gamma-aminobutyric acid), and aspartate by 213%, 455%, and 277%, respectively, from cerebrocortical synaptosomes. Verruculogen (400 mg mycelium/kg) increased the spontaneous release of glutamate and aspartate by 1300% and 1200%, respectively, but not that of GABA from cerebrocortical synaptosomes. The spontaneous release of the transmitter amino acids or other amino acids was not increased by the tremorgens in spinal cord/medullary synaptosomes. Penitrem A pretreatment reduced the veratrine (75 microM) stimulated release of glutamate, aspartate, and GABA from cerebrocortical synaptosomes by 33%, 46%, and 11%, respectively, and the stimulated release of glycine and GABA from spinal cord/medulla synaptosomes by 67% and 32% respectively. Verruculogen pretreatment did not alter the veratrine-induced release of transmitter amino acids from cerebrocortex and spinal cord/medulla synaptosomes. Penitrem A pretreatment increased the spontaneous release of aspartate, glutamate, and GABA by 68%, 62%, and 100%, respectively, from sheep corpus striatum synaptosomes but did not alter the synthesis and release of dopamine in this tissue. Verruculogen was shown to cause a substantial increase (300-400%) in the miniature-end-plate potential (m.e.p.p.) frequency at the locust neuromuscular junction. The response was detectable within 1 min, rose to a maximum within 5-7 min, and declined to the control rate over a similar period. No change in the amplitude of the m.e.p.p.'s was observed. These effects of the tremorgens on transmitter release are interpreted in terms of their mode of action.

The snouts of 2701 pork, bacon and heavy pigs killed at five abattoirs in England and Scotland during March to July 1974 were examined for evidence of atrophic rhinitis. Lesions were graded 1 to 5 according to severity. Suspicious lesions were present in 75-7 per cent of the sample. There was obvious atrophy of the turbinates in 44-7 per cent (grade 2 to 5) and severe atrophy in 17-5 per cent (grades 3 to 5). Foreign bodies were found in or between the posterior cheek teeth of 5-3 per cent of the sample. There was frequently an associated gingivitis. Other lesions seen included black discolouration of the teeth, severe tooth wear and osteoarthrosis of the temporomandibular joint. It was concluded that the incidence of atrophic rhinitis could have increased markedly since the last survey of the United Kingdom was undertaken in 1956/57 and some form of disease-monitoring service was urgently needed.

[14C] Verruculogen (75 micrograms/kg) was given intravenously to a sheep under barbiturate anaesthesia to prevent the severe tremor and convulsions which would otherwise have occurred. Two hours later 28 per cent of the tremorgenic mycotoxin was detected in the liver, bile and small intestine. Approximately 0.5 per cent was excreted in the urine. Trace amounts of radiolabel were detected in the cortex and corpus striatum of the brain. Verruculogen was metabolised by the liver and converted completely to four more polar products, including two isomeric forms of desoxy-verruculogen and the weakly tremorgenic mycotoxin TR-2. The principal and most polar metabolite excreted is probably an isomer of TR-2.

A postal survey was carried out by the Pig Veterinary Society to establish the opinions of its members on priorities for pig research: 153 members, 64 per cent of the total--returned analysable questionnaires. The survey shows that problems of highest priority for members are atrophic rhinitis, non-infectious infertility, neonatal enteritis, economics of disease, preventive medicine programmes and swine dysentery. The membership was classified by the nature of their work into five groups and the six subjects listed above cover the top three priorities of all groups. A classification of the papers listed in the Index of Current Research on Pigs XXII 1976 suggests that some of the six subjects are under researched.

The clinical responses of sheep dosed orally over seven to 14 weeks with the dried mycelium of a soil-borne mould containing the tremorgenic mycotoxin penitrem A are described. An initial tremoring response was gradually overshadowed by an incoordination syndrome similar to that seen in ryegrass staggers. In spite of protracted staggers symptomatology, correlated with in vitro changes in the release of neurotransmitter amino acids from corpus striatum nerve ending preparations, no histopathology was evident in the wide range of neural and other tissue studied. The biochemical nature of this reversible mycotoxicosis is discussed.

Supplementary biotin (1 mg d-biotin/kg feed) increased the compressive strength of the mid-abaxial sidewall region of pig's hoof from 9.3 (+/- 0.5) X 10(6) N/m2 to 12.0 (+/- 0.5) X 10(6) N/m2 (P less than 0.05). It also increased the hardness of this region, measured on the Shore A and D hardness scales (P less than 0.05). The leading edge of the hoof wall was significantly stronger than the sidewall (P less than 0.001) with a compressive strength of 14.5 (+/- 0.7) X 10(6) N/m2. This site showed no significant improvement in compressive strength or hardness in response to biotin. Biotin also produced a significant decrease in the hardness of the heel bulb on the Shore A scale (P less than 0.05). There would therefore appear to be a rational biomechanical basis for the finding by others that biotin reduces lameness. The Shore A and D hardness testers are sensitive to the improvement produced by biotin and may be useful as small, hand-held hoof testing devices for use in field conditions by the practising veterinarian.

The moulds Penicillium simplicissimum and P crustosum and the tremorgenic mycotoxins, verruculogen and penitrem A, isolated from them, were given to sheep and pigs to compare their potencies. Pigs were generally less susceptible and in both species penitrem A was less potent than verruculogen. Five-month-old lambs seemed more susceptible to mycelium containing verruculogen than were 15-month-old sheep given a similar oral dose relative to bodyweight. Repeated daily dosing of lambs and sheep for five days with P simplicissimum failed to enhance the effect, indicating that verruculogen toxicity was not cumulative. Long and short acting barbiturate anaesthesia blocked the effects of lethal doses of tremorgens. Sedation with diazepam diminished, but did not block, mycotoxin-induced tremors suggesting that there was no specific action of this anticonvulsant sedative on tremorgens.