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Biomedical subjects

J A Lawrence

Publications and source records attributed to J A Lawrence.

At least 55 records · Page 3Linked to original sources
PubMed1992

Spontaneous coping strategies to manage acute pain and anxiety during electrodiagnostic studies.

Electrodiagnostic studies produce both anxiety and pain, which can prevent adequate examination and limit the usefulness of test results. This study examined the spontaneous coping strategies used to manage the pain and anxiety experienced during electrodiagnostic testing. Fifty patients (26 women and 24 men) evaluated in our electrodiagnostic laboratory were administered visual analogue scale (VAS) pain and anxiety measures and the Spielberger State-Trait Anxiety Inventory (STAI) before the procedure. Immediately after the procedure, subjects reported pain, anxiety, and coping strategies used during electrodiagnostic testing using the VAS, the STAI, and a situation-specific version of the Coping Strategies Questionnaire (CSQ-S). The CSQ-S appears to be a valid and reliable measure of spontaneous coping strategies. Multiple-regression analyses revealed that frequent use of catastrophizing, diverting attention, and coping self-statement strategies was significantly and positively correlated with pain, whereas reinterpreting pain was significantly and negatively associated with pain. Judgments of control over pain were also significantly and negatively associated with anxiety experienced during electrodiagnostic studies. Physicians' ratings of pain and anxiety were highly correlated with patients' self-reports. This study suggests that ineffective coping strategies may enhance the pain and anxiety experienced during electromyography. Alternatively, teaching subjects active self-control skills and increasing patients' self-efficacy beliefs may help manage this situation-specific acute anxiety and, possibly, the associated pain.

Adaptation, Psychological↗
PubMed1991

Retrospective observations on the geographical relationship between Rhipicephalus appendiculatus and East Coast fever in southern Africa.

East Coast fever appeared in southern Africa in 1902, after the importation of cattle from East Africa, and spread throughout the range of Rhipicephalus appendiculatus until it reached the southern limit of distribution of this tick in 1916. It was progressively eradicated by quarantine, destocking, slaughter and frequent dipping in arsenic. The last case occurred in Swaziland in 1960. A computer based system for matching climates and ecology (CLIMEX) revealed a direct correlation between the climatic favorability of different areas for the tick and the time required to eradicate the disease.

Africa, Southern↗
PubMed1991

Retrospective observations on the transmission of East Coast fever in Zimbabwe.

Records of 283 outbreaks of East Coast fever in Zimbabwe in the period 1914 to 1946 reveal that transmission of infection occurred throughout the year with peaks in January to March and May to July. The high level of transmission in January to March coincides with the known seasonal occurrence of adult Rhipicephalus appendiculatus. It is suggested that transmission at other times of the year may have been effected by a population of R. appendiculatus which did not exhibit a strictly seasonal life-cycle and has since been eradicated.

Animals↗
PubMed1991

Theileria parva: influence of vector, parasite and host relationships on the epidemiology of theileriosis in southern Africa.

The protozoan parasite Theileria parva, transmitted by the ixodid tick Rhipicephalus appendiculatus, is the cause of East Coast fever (ECF) and the related syndromes of Corridor disease and January disease in cattle of eastern, central and southern Africa. It is likely that buffalo (syncerus caffer) are the natural host of T. parva. In eastern and southern Africa, there exists both buffalo-adapted and cattle-adapted T. parva. Disease caused by buffalo-adapted parasites is called Corridor disease, and that caused by cattle-adapted parasites is termed East Coast fever. In eastern Africa, it has been shown experimentally that buffalo-adapted T. parva can, after serial passage in cattle, become adapted to cattle, in which it can then be maintained and cause ECF. This adaptation has been termed transformation. The transformation of buffalo-adapted T. parva to a cattle-adapted parasite has not been reported in southern Africa, and ECF, eradicated from South Africa, Swaziland and southern Mozambique by 1960, has not reappeared in the subcontinent. This paper discusses the possible reasons for this, and hypothesizes that vector population dynamics and the susceptibility of the vector population to infection with T. parva are among the most important factors which influence the expression of ECF as a disease entity, and the likelihood of transformation occurring. It also considers the possibility that disappearance of ECF from southern Africa resulted from the extinction, as a result of vigorous control measures and unfavourable climatic conditions, of non-diapausing populations of R. appendiculatus that may have been introduced from eastern Africa with cattle imported in 1901.

Africa, Southern↗
PubMed1991

What makes nursing satisfying: a comparison of college students' and registered nurses' views.

This paper reports a study of nurses' perceptions of the positive and negative features of the work environment and their contribution to satisfaction with nursing. The concept of a 'work space' was developed to describe nurses' mental images of the features of their work environment. Eighty-four final-year student nurses and 75 registered nurses rated questionnaire items designed to examine perceptions of opportunities for professional development, sources of satisfaction, difficulties, time constraints and problematic interactions with other hospital personnel. There was general agreement among nurses about the aspects of their work that they found satisfying, but student nurses were more pessimistic than registered nurses that nursing would give them opportunities for recognition of their worth. Students returning from practica in critical care wards reported more stressful interactions with other personnel than students returning from general ward practica. Structural equation modelling of the causal relations between sources of satisfaction with nursing revealed that recognition and self-perceptions of work as a nurse were the strongest predictors of overall satisfaction with nursing. Caring for patients contributed only indirectly through its influence on nurses' feelings about themselves. The data indicate the significance of personal and social implications of nursing careers.

Adult↗
PubMed1990

Methods currently used for the control of anaplasmosis and babesiosis: their validity and proposals for future control strategies.

Four alternative approaches to the control of anaplasmosis and babesiosis as a complex of diseases are identified: no active control, tick control, immunization, and chemoprophylaxis. These methods may be utilized in one of five strategies: tick eradication with or without concurrent immunization, tick reduction with or without concurrent immunization or no active control. Factors influencing the choice of strategy are discussed.

Anaplasma↗
PubMed1989

Idiopathic septic gonitis in five Holstein-Friesian heifers.

Five cases of gonitis in young cows are reported. In all cases lameness was severe with no weight bearing on the affected limbs. The joints were swollen. No organisms were isolated from the fluids aspirated from the joints but cytological examination showed large numbers of neutrophils, and biochemical analysis showed increases in the activities of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and lactate dehydrogenase.

Animals↗
PubMed1989

Transmission of Theileria parva bovis (Boleni strain) to cattle resistant to the brown ear tick Rhipicephalus appendiculatus (Neumann).

Four crossbred Bos taurus oxen resistant to Rhipicephalus appendiculatus and three tick naive oxen of the same breed, which were all infested with adult R. appendiculatus infected with the Boleni strain of Theileria parva bovis, acquired Theileria infection. All four tick resistant oxen recovered after a mild febrile reaction. Two of the tick naive oxen died while the third recovered after a protracted period. It is suggested that tick resistance in cattle may be an important factor in establishing and maintaining enzootic stability in Theileria endemic areas.

Animals↗
PubMed1988

[3H]arginine vasopressin binding to rat brain: a homogenate and autoradiographic study.

Arginine-vasopressin (AVP) has been implicated as a putative central neurotransmitter or neuromodulator in some brain functions. This study demonstrates binding of [3H]AVP to rat brain homogenates that is pH and temperature dependent, is saturable (Kd = 0.77 nM, Bmax = 0.374 pmol/mg) and reversible. A number of AVP analogues competitively displaced the [3H]AVP binding, indicating that central AVP binding sites may have a resemblance to the peripheral (V1) AVP vasopressor receptor. Homogenate binding occurred predominantly in the microsomal fraction (P3) of the hypothalamus while in the hippocampus and septum binding was predominantly in the synaptosomal fraction (P2). Autoradiographic methods showed displaceable [3H]AVP binding in the lateral septum, amygdala, supraoptic, paraventricular and suprachiasmatic nuclei of the hypothalamus supporting the results of homogenate binding in preparations of these regions.

Animals↗
PubMed1985

Epidemiology of tick-borne diseases of cattle in Zimbabwe. III. Theileria parva group.

A survey of the occurrence of antibodies to Theileria parva using the IFA test in calves up to one year old at 244 localities in Zimbabwe revealed that the parasite occurred throughout the country although the prevalence of positive serological reactors was generally low. Outbreaks of theileriosis in high rainfall areas in the north, east and west of the country were attributed to Theileria parva bovis transmitted from cattle to cattle by Rhipicephalus appendiculatus. Outbreaks in high and low rainfall areas in the south and west of the country were attributed to Theileria parva lawrencei transmitted from buffalo to cattle by Rhipicephalus zambeziensis or R. appendiculatus. R. appendiculatus was not uniformly distributed in Zimbabwe. It occurred very commonly in foci in the commercial farming areas but was rare in most overgrazed communal farming areas. Outbreaks of disease attributed to T. parva bovis were recorded in some but not all the R. appendiculatus foci. The disease was present in areas infested with R. zambeziensis but it did not cause cattle deaths in these areas.

Animals↗
PubMed1984

Epidemiology of tick-borne diseases of cattle in Zimbabwe. II. Anaplasmosis.

A survey on the incidence of antibodies to Anaplasma marginale in one- to three-year-old cattle was carried out in Zimbabwe using the capillary tube agglutination test. Antibodies were detected in all but one of 118 batches of sera collected from different localities throughout the country. There was no clear relationship between the frequency of occurrence of positive serological reactors, which was similar in both commercial and communal farming areas, and the incidence of clinical anaplasmosis. However, the highest numbers of cattle exhibiting positive reactions were generally recorded from the areas that were most heavily tick infested. There was evidence that wild ungulates may serve as reservoirs of infection as antibodies to A. marginale were detected in sera from buffalo (Syncerus caffer) and impala (Aepyceros melampus).

Anaplasma↗
PubMed1983

Epidemiology of tick-borne diseases of cattle in Zimbabwe. I. Babesiosis.

A survey on the incidence of antibodies to Babesia bigemina and Babesia bovis in one to three year old calves at 274 localities in Zimbabwe revealed that B. bigemina occurred throughout the country together with its main vector, Boophilus decoloratus. The distribution of B. bovis followed closely that of its vector Boophilus microplus which is limited to the eastern part of the country. Enzootic stability for B. bigemina was recorded in most of the communal tribal areas where regular dipping of cattle had been interrupted for several years but was less common on commercial farms where regular dipping is practised. Enzootic stability for B. bovis was restricted to a few localities in communal areas and the parasite was rare on commercial farms.

Animals↗