Equal and opposite reaction to Willis.
Explore the source record for details and available documents.
History, 17th Century↗
Biomedical subjects
B H Smith
Publications and source records attributed to B H Smith.
The efficacy, safety, and practicality of treatments for adolescents with attention-deficit/hyperactivity disorder (ADHD).
Studies examining interventions for adolescents diagnosed with attention-deficit/hyperactivity disorder (ADHD) were reviewed to evaluate their efficacy. These efficacy findings were supplemented with a preliminary system for judging safety and practicality. Results suggest that the stimulant drug methylphenidate (MPH) is safe and well-established empirically, but has some problems with inconvenience and noncompliance. Preliminary research supports the efficacy, safety, and practicality of some psychotherapeutic interventions, including behavioral classroom interventions, note-taking training, and family therapy. Treatment with tricyclic antidepressants was judged to have minimal empirical support and debatable safety. Very little is known about long-term effectiveness of treatments, long-term compliance, or multimodal treatments for adolescents such as stimulants plus behavior therapy.
Adolescent↗
Heritable variation for latent inhibition and its correlation with reversal learning in honeybees (Apis mellifera).
Latent inhibition (LI) in honeybees (Apis mellifera) was studied by using a proboscis extension response conditioning procedure. Individual queens, drones, and workers differed in the degree to which they revealed LI. The authors hypothesized that individual differences would have a substantial genetic basis. Two sets of progeny were established by crossing virgin queens and individual drones, both of which had been selected for differential expression of inhibition. LI was stronger in the progeny from the queens and drones that had shown greater inhibition. The expression of LI was also dependent on environmental factors that are most likely associated with age, foraging experience outside of the colony, or both. Furthermore, there was a correlated response in the speed at which progeny reversed a learned discrimination of 2 odors. These genetic analyses may reveal underlying mechanisms that these 2 learning paradigms have in common.
Animals↗
Impairment of olfactory discrimination by blockade of GABA and nitric oxide activity in the honey bee antennal lobes.
Honey bees readily associate an odor with sucrose reinforcement, and the response generalizes to other odors as a function of structural similarity to the conditioned odor. Recent studies have shown that a portion of odor memory is consolidated in the antennal lobes (AL), where first-order synaptic processing of sensory information takes place. The AL and/or the sensory afferents that project into them show staining patterns for the enzyme nitric oxide synthase, which catalyzes the release of the gaseous transmitter nitric oxide (NO). The results show that pharmacological blockade of NO release impairs olfactory discrimination only when release is blocked before conditioning. Blockade of GABAergic transmission disrupts discrimination of similar but not dissimilar odorants, and does so when the block occurs before condition or before testing. These results show that GABA and NO regulate the specificity of associative olfactory memory in the AL.
Afferent Pathways↗
Sperm-mediated transformation of the honey bee, Apis mellifera.
Our primary objective was to identify techniques to transform the genome of the honey bee (Apis mellifera) with foreign DNA constructs. The strategy we adopted was to linearize foreign DNA and introduce it with sperm during the instrumental insemination of virgin queen honey bees. We analysed extracts from larvae within the same cohort and isolated the predicted fragment by means of PCR amplification of genomic DNA. Larvae that carried the construct also expressed the introduced DNA. We propagated several transgenic lines for up to three generations, which demonstrates its heritability. Once carried by a queen, the construct can be detected in that queen's larvae over several months. However, there was no evidence of integration of the construct, at least as determined by genomic Southern analysis. Nevertheless, this demonstrates the general viability of the technique for introduction of DNA, and it should be augmented by further use of transposable elements that enhance integration.
Animals↗
Associative olfactory learning in the moth Manduca sexta.
The proboscis extension response conditioning protocol has been used to explore olfactory-based associative learning in an array of insects. We have monitored a different feeding reflex, which involves activation of the cibarial pump, to demonstrate olfactory learning in the moth Manduca sexta. In the first experiment, four different treatment conditions were used to assess associative (Pavlovian) learning. The results indicate that an excitatory cibarial pump response develops and is retained for at least 24 h only when odor is forward-paired with the presentation of sucrose. Three control treatments, backward pairing, air (no odor) pairing and random pairing, failed to increase the cibarial pump response. However, an excitatory cibarial pump response developed when the backward- and air-paired groups received forward pairing of odor and sucrose on the following day. In contrast, moths experiencing random pairing on day 1 displayed a slower rate of acquisition during forward pairing on day 2, which may indicate inhibition. The second experiment investigated discrimination learning. Two odors were randomly presented, one odor being forward-paired with sucrose (+), the other presented alone (-) in a counterbalanced design. Again, only when odor was forward-paired with sucrose did learning occur. We discuss the implication of these findings for a broader comparative analysis of learning in insects.
Animals↗
Blocking and the detection of odor components in blends.
Recent studies of olfactory blocking have revealed that binary odorant mixtures are not always processed as though they give rise to mixture-unique configural properties. When animals are conditioned to one odorant (A) and then conditioned to a mixture of that odorant with a second (X), the ability to learn or express the association of X with reinforcement appears to be reduced relative to animals that were not preconditioned to A. A recent model of odor-based response patterns in the insect antennal lobe predicts that the strength of the blocking effect will be related to the perceptual similarity between the two odorants, i.e. greater similarity should increase the blocking effect. Here, we test that model in the honeybee Apis mellifera by first establishing a generalization matrix for three odorants and then testing for blocking between all possible combinations of them. We confirm earlier findings demonstrating the occurrence of the blocking effect in olfactory learning of compound stimuli. We show that the occurrence and the strength of the blocking effect depend on the odorants used in the experiment. In addition, we find very good agreement between our results and the model, and less agreement between our results and an alternative model recently proposed to explain the effect.
1-Octanol↗
Effects of dietary potassium citrate supplementation on urine pH and urinary relative supersaturation of calcium oxalate and struvite in healthy dogs.
OBJECTIVE: To assess the effect of dietary potassium citrate supplementation on the urinary pH, relative supersaturation of calcium oxalate and struvite (defined as the activity product/solubility product of the substance), and concentrations of magnesium, ammonium, phosphate, citrate, calcium, and oxalate in dogs. ANIMALS: 12 healthy adult dogs. PROCEDURE: Canned dog food was fed to dogs for 37 days. Dogs were randomly allocated to 3 groups and fed test diets for a period of 8 days. Study periods were separated by 6-day intervals. During each study period the dogs were fed either standard diet solus (control) or standard diet plus 1 of 2 types of potassium citrate supplements (150 mg potassium citrate/kg of body weight/d) twice daily. Urinary pH, volume and specific gravity, relative supersaturation of calcium oxalate and struvite, and concentrations of magnesium, ammonium, phosphate, calcium, oxalate, and citrate were assessed for each treatment. RESULTS: Mean urine pH was not significantly affected by dietary potassium citrate supplementation, although urine pH did increase by 0.2 pH units with supplementation. Diets containing potassium citrate maintained a higher urine pH for a longer part of the day than control diet. Three Miniature Schnauzers had a significantly lower urinary relative calcium oxalate supersaturation when fed a diet supplemented with potassium citrate, compared with control diet. CONCLUSIONS AND CLINICAL RELEVANCE: Dietary potassium citrate supplementation has limited effects on urinary variables in most healthy dogs, although supplementation results in maintenance of a higher urine pH later in the day. Consequently, if supplementation is introduced, dogs should be fed twice daily and potassium citrate should be given with both meals or with the evening meal only.
Animals↗
Glucose control and long-term survival in biobreeding/Worcester rats after intraperitoneal implantation of hydrophilic macrobeads containing porcine islets without immunosuppression.
BACKGROUND: We investigated the effectiveness of implanted macrobeads containing porcine islets as long-term therapy for type I diabetes mellitus in Biobreeding/Worcester (BB/Wor) rats, an animal model of spontaneous type I human diabetes. End points included acute control of glucose, weight gain, survival time, and the renal changes associated with diabetes. MATERIALS AND METHODS: Eighteen chronic spontaneously diabetic BB/Wor rats were each implanted with 56-150 porcine islet macrobeads secreting 1.3-5.2 U of insulin/24 hr in culture medium at 37 degrees C. Their clinical courses and selective histological observations were compared with those of animals maintained on Linplant insulin-release implants (6 rats) or protamine zinc insulin alone (10 rats). RESULTS: The rats that underwent porcine islet macrobead implantation (PIMI) survived for a mean of 171 days (range, 79-288) after implantation without exogenous insulin, immunosuppressive treatment, or lactated Ringer's therapy. All appeared healthy and maintained their body weights (mean 356+/-21 g) throughout this period, even though their nonfasting blood glucose levels fluctuated significantly, with the mean for the group being 245+/-102 mg/dl (range, 157-320 mg/dl). There was mild glucosuria in some animals. In comparison, the 10 BB/Wor rats maintained on exogenous protamine zinc insulin had a mean survival time of 53 days (range, 10-217), a "last entry" mean body weight of 283+/-23 g, and a mean nonfasting glucose level of 340+/-90 mg/dl. The six Linplant implant animals had a mean survival time of 164 days (range, 1-264 days), a "last entry" mean body weight of 374+/-21 g, and a mean nonfasting glucose level of 189+/-91 mg/dl (range, 135-219). Episodes of ketonuria, abrupt loss of body weight, dehydration, and symptomatic hypoglycemia were more common in both these groups than in the PIMI animals. Glucose tolerance tests comparing diabetic animals treated with porcine islet macrobead implants, exogenous insulin-treated diabetic BB/Wor rats, and normal nondiabetic Wistar-Furth rats showed that the responses of those with the macrobead implants were similar to those of the normal rats, while the exogenous insulin-treated diabetic BB/Wor rats had the expected abnormal responses. Light microscopic examination of the PIMI and Linplant animals' kidney sections appeared normal, whereas those of the exogenous insulin-injected BB rats showed moderate focal tubular atrophy and an increased mesangial matrix. Macrobeads retrieved from the peritoneal cavity at necropsy were found to secrete insulin, C-peptide, and glucagon, indicating that they were still functional after 199 or more days in the peritoneal cavity. CONCLUSIONS: Our results indicate that macrobeads containing porcine islets implanted intraperitoneally in natural insulin-dependent diabetic BB/Wor rats are capable of normalizing glucose control, permitting a normal life span, and preventing the renal changes normally associated with diabetes. Therefore, further short- and long-term studies of porcine islet macrobead implantation in chemically induced and naturally occurring diabetes in rodents, as well as larger animals including dogs, monkeys and possibly humans, are merited.
Animals↗
The epidemiology of chronic pain in the community.
BACKGROUND: Chronic pain is recognised as an important problem in the community but our understanding of the epidemiology of chronic pain remains limited. We undertook a study designed to quantify and describe the prevalence and distribution of chronic pain in the community. METHODS: A random sample of 5036 patients, aged 25 and over, was drawn from 29 general practices in the Grampian region of the UK and surveyed by a postal self-completion questionnaire. The questionnaire included case-screening questions, a question on the cause of the pain, the chronic pain grade questionnaire, the level of expressed needs questionnaire, and sociodemographic questions. FINDINGS: 3605 questionnaires were returned completed. 1817 (50.4%) of patients self reported chronic pain, equivalent to 46.5% of the general population. 576 reported back pain and 570 reported arthritis; these were the most common complaints and accounted for a third of all complaints. Backward stepwise logistic-regression modelling identified age, sex, housing tenure, and employment status as significant predictors of the presence of chronic pain in the community. 703 (48.7%) individuals with chronic pain had the least severe grade of pain, and 228 (15.8%) the most severe grade. Of those who reported chronic pain, 312 (17.2%) reported no expressed need, and 509 (28.0%) reported the highest expressed need. INTERPRETATION: Chronic pain is a major problem in the community and certain groups within the population are more likely to have chronic pain. A detailed understanding of the epidemiology of chronic pain is essential for efficient management of chronic pain in primary care.
Adult↗
Generalization between binary odor mixtures and their components in the rat.
We have adopted a conditioning paradigm to investigate generalization between odor mixtures and components. Rats were conditioned to find a reward buried in odor-scented cups. The conditioned odor was either a mixture (O1 + O2) or a pure component (O1). Once they learned the task to criterion, they were tested in random sequence for response to that O1, O1 + O2 and to an unrelated odor (O3). Generalization was consistently the strongest from O1 to O1 + O2 or from O1 + O2 to O1. Furthermore. the degree of generalization depended on the odorants used as O1, O2, and O3. This latter finding in a particular indicates that this assay can be used to assess properties of mixtures, which could arise at either peripheral or more central locations.
Animals↗
Relationship between the chronic pain grade and measures of physical, social and psychological well-being.
Chronic pain is an important cause of suffering, disability and loss of productivity within the community. Chronic pain can also be viewed as a multidimensional phenomenon, and may be associated with increased suffering of a social and psychological nature, as well as physical suffering. In this paper, the severity of the chronic pain gradings (CPG) is defined in terms of physical, social and psychological well-being, as measured by the SF36 and Glasgow Pain Questionnaire. Although previous work has shown the chronic pain grade to be a valid measure of chronic pain severity, little is known of the relationship between this and other health measures. A random sample of 5036 individuals, representative of the general population, stratified for age and sex, was drawn. A further sample of 4175 patients was drawn from a list of patients enrolled for repeat prescriptions for analgesic medication. A questionnaire survey was carried out, and response rates of 82 and 87% were achieved, respectively. The comparisons described confirm the widespread impact of chronic pain on all aspects of health, supporting the multidimensional view. These findings are important in addressing the management of chronic pain patients, and in particular, the social and psychological well-being of a patient needs to be addressed in parallel with the physical well-being in order to successfully reduce the suffering associated with chronic pain.
Adult↗
Chronic pain in primary care.
Chronic pain is a very common cause of suffering, disability and economic adversity in the community. It is a complex problem that needs to be understood in a multi-dimensional way for effective management. Most research to date has been based in specialist clinics rather than in primary care, with consequently limited findings. Chronic pain differs from acute pain in that management follows a rehabilitative rather than a treatment model, though these are not mutually exclusive. Full assessment of the patient, preferably multi-disciplinary, will improve his or her outlook. Management should be holistic, rigorous in the application of conventional therapies (including analgesics and physical therapy) and ready to admit an improved understanding of psychological and social techniques. There may be a role for complementary therapies. As a large proportion of chronic pain presents only in the community, there may be a role for greater primary care input to management.
Chronic Disease↗
Analysis of interaction in binary odorant mixtures.
An understanding of the olfactory system of any animal must account for how odor mixtures are perceived and processed. The present experiments apply associationist models to the study of how elements are processed in binary odorant mixtures. Using experimental designs for Proboscis Extension Conditioning of honey bees, I show that learning about a pure odorant element is frequently affected by its occurrence in a mixture with a second odorant. Presence of a background odor when an odorant is associated with sucrose reinforcement decreases the rate and/or asymptotic level of associative strength that accumulates to that odorant. This interaction is in part due to synthetic qualities that arise in sensory transduction and initial processing. In addition, it involves an attention-like processing system like that involved in overshadowing. Therefore, a model that includes representations of the component and configural qualities of odorants in mixtures is needed to provide a more complete account of learning about odor mixtures.
Acyclic Monoterpenes↗
Over-the-counter emergency contraception: a feasible option.
BACKGROUND: The high number of unintended pregnancies and terminations in Britain indicates that women who could use emergency contraception do not. Knowledge of access to sources of emergency contraception is limited. Oral administration of combined oestrogen-progestogen is safe and does not require routine physical administration, and there are proposals to re-regulate this from a prescription-only medicine to a pharmacy medicine, available over the counter in community pharmacies under the supervision of a pharmacist. OBJECTIVES: We aimed to demonstrate that the availability of combined, oral oestrogen-progestogen under the supervision of the community pharmacist would be safe and effective. METHOD: Guidelines were developed by a multidisciplinary group incorporating pharmacists, GPs, a pharmacologist and a consultant in family planning. The guidelines were based on published evidence, where possible. CONCLUSION: Guidelines have been developed to accompany the provision of combined, oral oestrogen-progestogen which demonstrate that over-the-counter availability could be a safe and effective method of reducing the number of unwanted pregnancies in Britain.
Contraceptives, Oral↗
The effect of diet on lower urinary tract diseases in cats.
Because dietary ingredients and feeding patterns influence the volume, pH and solute concentration of urine, diet can contribute to the etiology, management or prevention of recurrence of some causes of lower urinary tract disease. Most research assessing the effect of diet has focused on the latter two aspects, primarily because of interest in struvite urolithiasis. Manipulation of urine pH through dietary means has proven an effective tool for the management and prevention of struvite urolithiasis; acidification of urine, however, may be a risk factor for calcium oxalate urolithiasis, which now appears to occur with approximately equal frequency in cats. Prediction of urine pH from dietary analysis would thus be a valuable tool, but considerable further research is required before this can be achieved with commercial canned foods. With the growing importance of urolith types other than struvite, alternatives to the measurement of urine pH are required to assess critically the likely beneficial (or detrimental) effects of manipulation of nutrient profile. Measurement of urinary saturation may permit the development and fine tuning of nutrient profiles aimed at controlling lower urinary tract diseases in cats that are associated with a range of different mineral types. The majority of cats with signs of lower urinary tract disease do not, however, have urolithiasis; indeed, no specific cause can be established in most of these cats. Recent observations suggest that recurrence rates of signs in cats classified as having idiopathic lower urinary tract disease may be more than halved if affected animals are maintained on high, rather than low moisture content diets. J. Nutr. 2753S-2757S, 1998
Animals↗
A system to monitor urinary tract health in dogs.
Explore the source record for details and available documents.
Animals↗
Urinary relative supersaturations of calcium oxalate and struvite in cats are influenced by diet.
Explore the source record for details and available documents.
Animal Feed↗