Ectoparasites of a population of urban gray squirrels in northern Florida

Ectoparasites infesting a population of urban gray squirrels (Sciurus carolinensis Gmelin) in northern Florida were collected monthly during 1974. Eleven species were identified: one flea (Orchopeas howardi (Baker], three suckling lice (Enderleinellus longiceps Kellogg & Ferris, Hoplopleura sciuricola Ferris, and Neohaematopinus sciuri Jancke), one tick (Dermacentor variabilis Say), two mesostigmatid (gamasid) mites (Androlaelaps casalis (Berlese) and A. fahrenholzi (Berlese], and four chiggers (Eutrombicula alfreddugesi (Oudemans), E. splendens (Ewing), Leptotrombidium peromysci Vercammen-Grandjean & Langston, and Parasecia gurneyi (Ewing]. The flea and three suckling lice represent core species of ectoparasites for the gray squirrel; the remainder are probably satellite species. Only E. longiceps varied significantly in prevalence or intensity of infestation among host age groups; subadult squirrels had higher intensities than adults. Peak prevalence of O. howardi occurred in January and attained maximum intensity in March, whereas both prevalance and intensity were minimum in August. Prevalence of H. sciuricola was maximum in November and remained at similar levels through June. It then declined significantly to its minimum in September-October. Intensity of infestation, however, was greatest in August, September, and January. Maximum prevalence of N. sciuri occurred from January to March and was minimum in September; intensity of infestation reached maxima in January, June, and August.     

Experimental transmission of Plasmodium mexicanum by bites of infected Lutzomyia vexator (Diptera: Psychodidae)

Lutzomyia vexator is an efficient experimental vector of Plasmodium mexicanum, infecting 69.2% (9/13) of the Sceloporus undulatus lizards with as few as one bite. Sporozoites were present in the salivary glands by day 6.5 postfeed and infective by day 8 postfeed at 27 degrees C. The prepatent period was relatively long, ranging from 23 to 40 days for bite-induced infections and appears to be related to the number of sporozoites injected. The acute phase of the infection is initially exponential and rapid. All lizards (6) that were not sacrificed, died of fulminating infections from 13 to 56 days after parasites were seen in the blood films. Gametocytes from 2 experimentally infected lizards were infective to L. vexator during the course of the acute infection. The majority of P. mexicanum parasites were in erythrocytes of Sc. undulatus. Exoerythrocytic forms were observed in circulating lymphocytes and thrombocytes, lymphocytes of spleen and bone marrow, and endothelial cells of brain capillaries.     

The effect of 7 to 8 months of vitamin/mineral supplementation on the vitamin and mineral status of athletes.

Blood indicators of eight vitamins (B1, B2, B6, C, E, A, B12, folate) and six minerals (Cu, Mg, Zn, Ca, P, Al) were measured in 86 athletes before and after a 7- to 8-month period of training. During this period half consumed a multivitamin/mineral supplement and a matched group took a placebo. Following the supplementation period, blood biochemical indicators of B1, B6, B12, and folate status all increased but there were no significant effects of supplementation on B2, C, E, and A, or on the blood levels of any of the minerals. The supplementation had no effect on red or white cell counts or on hemoglobin levels. Irrespective of the supplementation, some blood measures varied according to sex, females evidencing significantly higher values than males for vitamins C, E, copper, magnesium, and aluminium, with B2 being higher in males. It is concluded that 7 to 8 months of multivitamin/mineral supplementation increased the blood nutritional status of some vitamins but did not affect any blood mineral levels, and that some blood nutritional indicators may vary according to sex.     

Benchmarking in national health service procurement in Scotland.

The paper reports the results of a study on benchmarking activities undertaken by the procurement organization within the National Health Service (NHS) in Scotland, namely National Procurement (previously Scottish Healthcare Supplies Contracts Branch). NHS performance is of course politically important, and benchmarking is increasingly seen as a means to improve performance, so the study was carried out to determine if the current benchmarking approaches could be enhanced. A review of the benchmarking activities used by the private sector, local government and NHS organizations was carried out to establish a framework of the motivations, benefits, problems and costs associated with benchmarking. This framework was used to carry out the research through case studies and a questionnaire survey of NHS procurement organizations both in Scotland and other parts of the UK. Nine of the 16 Scottish Health Boards surveyed reported carrying out benchmarking during the last three years. The findings of the research were that there were similarities in approaches between local government and NHS Scotland Health, but differences between NHS Scotland and other UK NHS procurement organizations. Benefits were seen as significant and it was recommended that National Procurement should pursue the formation of a benchmarking group with members drawn from NHS Scotland and external benchmarking bodies to establish measures to be used in benchmarking across the whole of NHS Scotland.     

Canal-otolith interactions in the squirrel monkey vestibulo-ocular reflex and the influence of fixation distance

Natural head movements include angular and linear components of motion. Two classes of vestibulo-ocular reflex (VOR), mediated by the semicircular canals and otoliths (the angular and linear VOR, or AVOR and LVOR, respectively), compensate for head movements and help maintain binocular fixation on targets in space. In this study, AVOR/LVOR interactions were quantified during complex head motion over a broad range of fixation distances at a fixed stimulus frequency of 4.0 Hz. Binocular eye movements were recorded (search-coil technique) in squirrel monkeys while fixation distance (assessed by vergence) was varied using brief presentations of earth-fixed targets at various distances. Stimuli consisted of rotations around an earth-vertical axis and therefore always activated the AVOR. Horizontal and vertical AVORs were assessed when the head was centered over the axis of rotation and oriented upright (UP) and right-side-down (RD), respectively. AVOR gains increased slightly with increasing vergence in darkness, as expected given the small anterior position of the eyes in the head. Combined AVOR/LVOR responses were recorded when subjects were displaced eccentrically from the rotation axis. Eccentric rotations activated the AVOR just as when the head was centered, but added a translational stimulus which generated an LVOR component in response to interaural (IA) or dorsoventral (DV) tangential accelerations, depending on whether the head was UP or RD, respectively. When the head was eccentric and facing nose-out, the AVOR and LVOR produced ocular responses in the same plane and direction (coplanar and synergistic), and response magnitudes increased with increasing vergence. With the head facing nose-in, AVOR and LVOR response components were oppositely directed (coplanar and antagonistic). The AVOR dominated the response when fixation distance was far, and phase was compensatory for head rotation. As fixation distance decreased toward the rotation axis, responses declined to near zero, and when fixation distance approached even closer, the LVOR component dominated and response phase inverted. The same pattern was observed for both horizontal (head UP) and vertical (head RD) responses. The LVOR was recorded directly by rotating subjects eccentrically but in the nose-up (NU) orientation. The AVOR then generated torsional responses to head roll, coexistent with either horizontal or vertical LVOR responses to tangential acceleration when the subject was oriented head-out or right-side-out, respectively. Only the LVOR response components were modulated by vergence. A vectorial analysis of AVOR, LVOR, and combined responses supports the conclusion that AVOR and LVOR response components combine linearly during complex head motion. Received: 27 February 1997 / Accepted: 18 June 1997     

Suppression of autoimmune disease in NZB/W F1 mice by treatment with the novel immunomodulator BTS 63155.

Autoimmune disease in NZB/W F1 mice was treated from 23 weeks of age with the novel immunomodulator BTS 63155 and, for comparative purposes, the established immunosuppressive agent cyclosporin A. Both drugs significantly improved survival compared with untreated controls. Lupus nephritis was also significantly reduced in the drug-treated groups, and this was related to reduced glomerular deposition of IgG. Autoantibody (ANA) levels were lowered by treatment with cyclosporin A, but not by BTS 63155. This latter finding may indicate a different mode of action for the two drugs. In a long term study, neither drug effected a complete cure, as autoimmune disease recurred on withdrawal of drug treatment.     

Exercise, training and neutrophil microbicidal activity

The concentration in human plasma of putative neutrophil-"priming" cytokines like endogenous pyrogens is known to increase significantly in response to moderate exercise (11). This is characteristic of an acute-phase response. The ability of blood neutrophils isolated from both trained and untrained human subjects (n = 11, 9) to produce microbicidal reactive oxygen species was determined using luminol-enhanced chemiluminescence both before and after one hour of aerobic exercise at 60% VO2max. Irrespective of training and stimulus concentration, exercise nearly always caused significant "priming" of the capacity of neutrophils to produce H2O2 and HOCl upon stimulation with opsonized zymosan (P less than 0.01); however, compared to their untrained counterparts, the activity of cells isolated from trained individuals was depressed about 50% at unit stimulus concentration, both before and after exercise (P less than 0.075), whilst remaining unaltered at saturating concentrations. Although neutrophil oxygenation activity is only one parameter that contributes to immunological status, regular episodes of moderate exercise may increase resistance to infection by priming the "killing capacity" of neutrophils. In contrast, prolonged periods of intensive training may lead to increased susceptibility to common infections by diminishing this activity.     

Is choice of general practitioner important for patients having coronary artery investigations?

OBJECTIVE--To determine whether particular sociodemographic characteristics of patients with stable angina affected their general practitioners' (GPs') decisions to refer them for revascularisation assessment. DESIGN--Postal questionnaire survey. SETTING--Collaborative survey by the departments of public health medicine in each of the four health boards in Northern Ireland, serving a total population of 1.5 million. SUBJECTS--All (962) GPs. MAIN MEASURES--The relation between GPs' referral decisions and patients' age, sex, employment status, home circumstances, smoking habits, and obesity. RESULTS--541 GPs replied (response rate 56%). Most were "neutral" towards a patient's sex (428, 79%), weight (331, 61%), smoking habit (302, 56%), employment status (431, 80%), and home circumstances (408, 75%) in making decisions about referral. In assigning priority for surgery most were neutral towards the patient's sex (459, 85%), employment status (378, 70%), and home circumstances (295, 55%). However, most GPs (518, 95%) said that younger patients were more likely to be referred, and a significant minority were less likely to refer patients who smoked (202, 37%) and obese patients (175, 32%) and more likely to refer employed patients (97, 18%) and those with dependents (117, 22%) (compared with patients with otherwise comparable clinical characteristics); these views paralleled the priority which GPs assigned these groups. The stated likelihood of referral of young patients was independent of the GPs' belief in ability to benefit from revascularisation, but propensity to refer and perception of benefit were significantly associated for all other patient characteristics. CONCLUSION--GPs' weighting of certain characteristics in reaching decisions about referral for angiography is not uniform and may contribute to unequal access to revascularisation services for certain patient groups.     

Expanding access to coronary artery bypass surgery: who stands to gain?

OBJECTIVE--To determine the perceptions of general practitioners (GPs) about the benefits of coronary artery bypass surgery, in terms of gains in life expectancy, for different groups of patients. DESIGN--A questionnaire survey of all GPs in Northern Ireland. SETTING--A survey conducted collaboratively by the departments of public health medicine in each of the four health boards in the province, serving a total population of 1.5 million. MAIN OUTCOME MEASURES--The median and mean gain in life expectancy perceived by groups of doctors for smoking and non-smoking male and female 55 year old patients. The percentage of 50 year old and 70 year old non-smoking patients considered likely to have their lives extended with bypass surgery. Differences were assessed using the Mann-Whitney U test for unpaired samples and the Wilcoxon signed rank tests for paired. RESULTS--541 GPs replied (response rate 56%). The median (and mean) perceived gain in life expectancy after cardiac surgery for non-smoking 55 year old subjects was 120 (104) months for men and 120 (112) months for women (z = 6.42; P < 0.0001; Wilcoxon signed rank test). For male and female smokers of the same age, the perceived gains were 48 (47) and 60 (52) months respectively (z = 6.72; P < 0.0001; Wilcoxon signed ranks test), both figures being significantly different than for non-smokers. The median (and mean) percentage of patients that the doctors considered would have their lives extended by bypass surgery was 70 (64) of every 100 "young" patients and 40 (42) of every 100 "old" patients, (z = 16.2; P < 0.0001). CONCLUSIONS--These results point to a significant overestimation of the benefits of coronary artery bypass surgery by GPs in Northern Ireland and to a need to develop guidelines for referral.