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Biomedical subjects

J K Blackshaw

Publications and source records attributed to J K Blackshaw.

At least 19 recordsLinked to original sources
PubMed2000

An evolutionary approach to psychiatry.

OBJECTIVE: The current mainstream approach to psychiatry, characterised as empirical and phenomenological is questioned here and a new aetiological approach based on evolutionary theory is proposed. METHOD: A brief description of an evolutionary approach to animal behaviour is presented. The psychiatric states of anxiety, depression, 'hysterical' obsession and some aspects of psychosis are compared with related behaviours in other species. RESULTS: It is argued that this approach can be applied to psychiatric behaviour, that behavioural similarities exist between many psychiatric states and normal behaviour in species other than humans and many of these can be understood as adaptive. Some psychiatric states represent abnormally prominent adaptive behaviours, others represent distortions of these behaviours by a pathological process. An important line of thought in current animal behaviour research examines the concepts of self-awareness, consciousness, thought and affect in species other than man. These ideas, from an evolutionary perspective, are extended to psychiatry. A scheme illustrating this process is presented. CONCLUSIONS: We have drawn on relevant behavioural similarities between humans and other animals to show that many psychiatric states are distortions of evolved behaviour. The implications for classification, research and treatment are considerable. In particular this approach may form a bridge between fundamental research in molecular biology and the anthropomorphic approach of psychodynamics.

Adaptation, Psychological↗
PubMed1996

Tail docking in dogs: a sample of attitudes of veterinarians and dog breeders in Queensland.

One hundred veterinarians and 100 breeders of traditionally docked dogs from Queensland were surveyed by telephone to determine their attitudes towards tail docking. Eighty-four percent of the breeders surveyed were in favour of docking, whereas 83% of veterinarians were opposed to the practice. Most pups were docked between 1 and 3 days of age. All veterinarians surgically amputated the tail, whereas 16% of breeders applied rubber bands to the tail. Seventy-six percent of the veterinarians, but only 18% of the breeders believed that docking caused significant to severe pain. No veterinarians, but 25% of the dog breeders believed that docking was painless. Although recent changes to the Queensland Canine Control Council's rulings allow dogs with intact tails to be shown in traditionally docked classes, the requirement of breed standard was cited as the major reason for tail docking by both breeders and veterinarians.

Animals↗
PubMed1994

Attitudes of dog owners to neutering pets: demographic data and effects of owner attitudes.

A survey of the attitudes of dog owners to desexing male and female dogs was conducted in the Brisbane area. Over 15,800 replies (35% response) were returned for analyses and included both demographic and attitude data. The most common reasons given by owners for not having the dog desexed were that it was unnecessary or they wanted to breed from it or could not afford it or did not agree with it or that the dog was too old or it might get fat. Nearly twice as many male owners agreed that desexing male dogs removed maleness and also more males agreed with the question "Do you equate dog sexuality with human sexuality?" Female owners were more aware than males that their female dogs did not need to have a season (oestrus) or a litter before being desexed. More male owners thought that desexing changed a male or female dog's personality. A disturbing fact was that 61.1% of male owners and 47.3% of female owners would now not have their dog desexed if it had not already been done. More male than female dog owners were ignorant about whether desexing changed personality, made dogs frustrated, or if female dogs should have a season or a litter before desexing. The study showed a gender bias in owner attitudes to all the attitude questions.

Animals↗
PubMed1989

Limitations of salivary and blood cortisol determinations in pigs.

Blood and saliva samples were taken from groups of pigs maintained in intensive conditions. Multiple samples were taken from two unrestrained pregnant sows fitted with jugular cannulae. Single samples were taken from groups (mixed gilts and entire males; 70-90 kg) which were lightly exercised (7) or restrained (12). The rate of salivary secretion was low and collection of adequate samples took 5 min; in a number of pigs no saliva could be obtained. In order to stimulate salivary secretion, pigs (70-80 kg) were injected with pilocarpine nitrate (25 mg, subcutaneous) which produced a copious flow of saliva persisting for at least 15 min. Resting sows had higher mean levels of cortisol in plasma, ultrafiltrate and saliva than the other groups, which did not differ from each other. Within the pilocarpine group, males had a higher ultrafiltrate level of cortisol than females. In most instances salivary cortisol was significantly greater than ultrafiltrate cortisol. Ultrafiltrate and plasma cortisol were highly correlated (r = 0.883) but this correlation was low in the presence of pilocarpine (r = 0.260). Salivary cortisol was poorly correlated with either plasma (r = 0.167) or ultrafiltrate cortisol (r = 0.278) and the correlation with plasma was even lower following the administration of pilocarpine (r = 0.086). It was concluded that salivary estimates of cortisol in the pig were not usefully correlated with levels of ultrafiltrate (free) cortisol.

Animals↗
PubMed1989

Carbon dioxide as a short-term restraint anaesthetic in rats with subclinical respiratory disease.

The use of carbon dioxide (CO2) with, and without, oxygen (O2) as a short-term restraint anaesthetic for Wistar rats in which subclinical respiratory disease was endemic, was assessed in 3 separate experiments. In the first, rats were placed in a CO2 atmosphere generated from solid CO2 chips in a 70 l plastic bin, and removed at time intervals ranging from 0 to 120 s after disappearance of the pedal reflex. Eight of 25 rats died, including 2 which were removed immediately the pedal reflex disappeared; it was concluded that CO2 without O2 was not a suitable short-term anaesthetic for rats. In a second study, rats were anaesthetized in atmospheres of 50:50 and 80:20 (CO2:O2) provided from commercially available cylinders, in 2 different environments--a 3.41 glass jar and a 17 l plastic bin. Rats became excited in the plastic bin but not the glass jar. Rats in the glass jar displayed visible depression and cessation of whiskers movement significantly more quickly in the 80:20 (CO2:O2) than in the 50:50 mixture (4.2 +/- 0.98 s, n = 6, and 66.0 +/- 4.9 s, n = 6 vs 13.8 +/- 2.77 s, n = 5 and 152.0 +/- 20.8 s, n = 5, respectively). Rats in the 17 l plastic bin lost their pedal reflexes in a mean 41.5 +/- 4.55 s (n = 11) in the 50:50 mixture and in a mean 30.9 +/- 6.38 s (n = 11) in the 80:20 (CO2:O2) group. Those left in the 50:50 mixture for 60 s and 180 s after disappearance of their pedal reflexes, recovered these reflexes in 20.2 +/- 0.44 s and 21.5 +/- 7.23 s respectively after removal from the gas. Respiration and heart beat ceased in one rat remaining in the 50:50 mixture after 13 min 10 s. No untoward effects occurred in rats left in the 50:50 mixture for 180 s after disappearance of the pedal reflex, but 2 died when left for an equivalent period in the 80:20 mixture. In the third study, examples of the practical use of a 50:50 mixture as a short term restraint anaesthetic are described. It was concluded that this mixture was a cheap, safe, and effective means of short-term restraint for rats with subclinical respiratory disease, when the minimal time of exposure to the gases was employed.

Anesthesia↗
PubMed1988

The behaviour of chickens, mice and rats during euthanasia with chloroform, carbon dioxide and ether.

Euthanasia of chickens, young and mature rats, and mice was assessed using chloroform, carbon dioxide and ether. Behavioural patterns were recorded to give some indication of the stress involved. Carbon dioxide induced collapse faster (11.2 +/- 0.4 s) than chloroform (18.9 +/- 0.4 s) or ether (greater than 60 s). With regard to the time taken to death, in carbon dioxide mice had the shortest time (48 +/- 10 s) and mature rats had the longest time (135 +/- 10 s). In chloroform, the only difference was the delayed onset of death (127 +/- 10 s) in the chicken. Behavioural patterns were similar for the chicken in carbon dioxide and chloroform, except for wing flapping, even when unconscious, in carbon dioxide. Chloroform is recommended as more aesthetically acceptable for euthanasia of chickens. Carbon dioxide is recommended for the euthanasia of both rats and mice, considering behavioural criteria. Ether is unsuitable as a euthanasia method as it is dangerous, slow acting and an irritant.

Animals↗
PubMed1986

The effects of delays between restraint and sampling on some blood parameters in sheep.

Twenty three non pregnant, non lactating aged Merino and Border Leicester ewes were subject to four jugular venipunctures one hour apart (times 0, 1, 2 and 3). Four different delay intervals of 12.5, 64.0, 128.0 and 252.9 seconds between catching and sampling (delays 1, 2, 3 and 4) were used on each sheep in a random manner. Estimates were made of packed cell volumes (PCVs), plasma and erythrocyte sodium and potassium concentrations. The mean PCV at time 0 of 35.4 per cent was significantly higher than the levels of 33.1, 31.8 and 32.2 per cent at times 1, 2 and 3 respectively. There was no significant difference between the means at times 1, 2 and 3. The mean plasma potassium concentrations at time 0 of 4.37 mmol/l was significantly higher than the levels of 4.16 and 4.14 mmol/l at times 1 and 3 respectively. Delays had no significant effects on the means of any of the parameters studied. The findings strongly suggest that sheep become excited by initial handling but not by subsequent venipunctures and that a delay between catching and sampling of between 12.5 and 252.9 second has no effect on the blood constituents studied.

Animals↗
PubMed1986

Objective measures of welfare in farming environments.

Welfare in farm animals is both difficult to define and measure. Definitions of welfare and the indicators of welfare which can be scientifically measured are discussed. These indicators are health, productivity, physiological and biochemical changes, and behavioural patterns; they can often be correlated from a husbandry system to give a good indication of the welfare status of the animals in the system. Most of the research work in this area has been done in the intensive pig and poultry industries, although the correlation of biochemical measures with husbandry procedures used in sheep and cattle has begun. It is difficult at this stage to develop a simple stress test that would take all the variables into account, but a change of any of the indicators will suggest further investigation is required. The most obvious to monitor is behaviour, as even a slight change can indicate a change in welfare status.

Animal Husbandry↗
PubMed1985

The effects of "holding" on some blood parameters in goats.

One young male and five female goats aged from four months to mature full-mouthed were handled by stroking and raising the jugular vein intermittently for one minute each day for four days. A control group was kept in a similar pen out of sight of the test group for the four days and approached only when attended for pen cleaning and feeding. On the fifth day, heparinised blood samples were taken once hourly for a period of three hours by jugular venepuncture from both groups. After processing, the samples were examined for packed cell volumes, plasma and erythrocyte potassium and sodium concentrations. Analysis of variance of the data showed a significant (P less than 0.01) reduction in erythrocyte potassium concentration in the unhandled group (76.3 mmol/l to 74.2 mmol/l) from Time 0 to Time 1, and a similarly significant increase in levels in the handled group (73.7 mmol/l to 78.0 mmol/l) from Time 0 to Time 1. There was also a significant difference (P less than 0.05) in packed cell volumes between the unhandled and handled groups at Time 0 and Time 1 (28.6% v 25.2% and 27.6% v 25.0% respectively). There were no significant differences between the two groups in plasma sodium, plasma potassium or erythrocyte sodium.

Animals↗