The Gulf Coast tick: a review of the life history, ecology, distribution, and emergence as an arthropod of medical and veterinary importance.

The Gulf Coast tick, Amblyomma maculatum Koch (Acari: Ixodidae), is a unique univoltine ectoparasite of seven vertebrate host classes in the Western Hemisphere that is increasingly recognized as a pest of livestock and wildlife, a vector of pathogens to humans and canines, and a putative vector of Ehrlichia ruminantium, the causal agent of heartwater, a fatal foreign animal disease of ruminants resident in the Caribbean. This review assembles current and historical literature encompassing the biology, ecology, and zoogeography of this tick and provides new assessments of changes in cyclical population distribution, habitat associations, host utilization, seasonal phenology, and life history. These assessments are pertinent to the emergence of A. maculatum as a vector of veterinary and medical importance, and its pest management on livestock and other animals.

Radiation doses to patients during ERCP.

BACKGROUND: There is a scarcity of data regarding the radiation dose and associated risks to patients during ERCP. Dose area product (DAP) measurements can be used to estimate an effective dose (ED) to patients undergoing ERCP. This measure allows radiation risk associated with such procedures to be quantified. The aim of this study was to evaluate the ED to patients undergoing ERCP. METHODS: A DAP meter was fitted to the x-ray tube before each ERCP. DAP reading (Gy-cm(2)), fluoroscopy time, average screening kVp, number of films, and kVp per film were recorded. Mean ED was estimated by using DAP readings and Monte Carlo computer software to model radiation exposure conditions. RESULTS: Data were recorded on 20 subjects. Average DAP was 13.5 Gy-cm(2) (6.8-23.9) for diagnostic and 66.8 Gy-cm(2) (28.7-108.5) for therapeutic ERCP (p < 0.05). Average fluoroscopy time was 2.3 minutes (1.1-5.3) for diagnostic and 10.5 minutes (5.9-16.6) for therapeutic ERCP (p < 0.05). DAP showed a linear relationship with fluoroscopy time (R(2) = 0.928). Mean number of diagnostic and therapeutic films was 2.8 and 3.7, respectively. Fluoroscopic exposure represented 69% of the DAP for diagnostic ERCP and 90% of the DAP for therapeutic ERCP. Average ED was 3.1 mSv for diagnostic and 12.4 mSv for therapeutic ERCP. CONCLUSIONS: Therapeutic ERCP is associated with significantly higher radiation exposure than diagnostic ERCP. ED in therapeutic ERCP is a result largely of fluoroscopy time as opposed to number of films.

Post-operative computed tomography in two dogs with cerebral meningioma.

Post-operative computed tomography (CT) has been described as a technique for diagnosing incomplete resection or recurrence of cerebral neoplasms in humans. The characteristics of immediate postoperative CT images in dogs with intracranial pathology are unknown. This report describes findings from preoperative, immediate post-operative, and 4 week to 9 month follow-up CT examinations in two dogs with histologically-confirmed cerebral meningiomas. In images of one dog after surgery there was mild contrast enhancement of the tissue surrounding the surgical site. This enhancement had resolved in later images and was probably the result of surgically induced trauma. In post operative images of the other dog there was significant hyperattenuation of the tissues around the surgical site. In post contrast images there was increased enhancement that was evident in later images. These findings, although not supported by necropsy, probably indicate incomplete excision of the tumor.

Radiation doses to patients during pharyngeal videofluoroscopy.

Pharyngeal videofluoroscopy (VTF) is a well-recognized technique for investigating and assessing swallowing disorders. There is, however, a paucity of data available regarding the radiation dose to patients during such procedures, but there is general concern that fluorographic imaging modalities are associated with significant radiation exposure. We have recorded the dose received by 23 patients undergoing VTF in our department using a Dose-Area Product (DAP) Meter and have used the data to calculate the effective dose to the patients. The mean effective dose is 0.4 mSv (range 0.027-1.1) which compares favorably with the effective doses associated with other common radiological procedures. We therefore conclude that the radiation detriment associated with pharyngeal VTF is well within acceptable levels.

Patient perception and localization of dysphagia -- barium study correlation.

We assessed the accuracy of patient localization of the site of dysphagia and its implications for radiological practice during the barium swallow examination. Several current texts dispute the value of such information. Fifty-two consecutive patients with dysphagia were asked to localize the site of discomfort on the skin surface. The ability of each patient to do so precisely or vaguely was noted. A detailed barium examination of the pharynx, esophagus and stomach was performed. Results suggested that patients who had symptoms more cranial than the sternal notch were highly accurate at localizing disease. Localization became less precise as symptoms moved caudally towards the epigastrium. Lateralization of symptoms was highly accurate in determining the site of pathology. In conclusion, we feel that in certain circumstances the barium examination can be usefully tailored to accelerate examination times, thus reducing radiation exposure and cost whilst improving diagnostic accuracy.

The decline of fertility in Malta: the role of family planning.

PIP: This study examines the nature and extent of contraceptive use in Malta and determines what factors affected the shift from traditional to modern methods. Data were obtained from the 1993 Survey of Family Planning in Malta of 98 general medical practitioners and up to 15 clients per practitioner and a similar 1971 survey. The total fertility rate in Malta declined from 2.25 in 1967 to 2.00 in 1985. Changes occurred such that the influence of the Church declined, formal education increased, legislation supported family planning, and income increased. Both Malta surveys indicated a proportion who did not attempt to space or limit births and some who relied on more than one method. During 1971-93, choice of contraceptive method changed from traditional methods to oral pills and condoms. Government family planning clinics were set up in 1981 and provided information that included natural methods. Diaphragms were provided free of charge. Abortion was, and still is, illegal. Sterilization is also illegal; male sterilization is more accessible. The probability of a woman using some form of contraception is modeled. Findings suggest that age has little impact. Women with 2-3 children and more highly educated women had higher probabilities of using contraception. Older married women and better educated women had a higher probability of use and use of the rhythm method. Family size was unrelated to use of the rhythm method. Age and marital duration were unrelated to use of coitus interruptus. Better educated women were unlikely to rely on coitus interruptus. Condom use was unrelated to age, education, family size, or marriage duration. Younger women were more likely to use the pill and more effective methods of contraception. Effective contraceptive use was related to better female education, larger family size, and longer marriage duration.^ieng

Manipulation under epidural anesthesia with corticosteroid injection: two case reports.

OBJECTIVE: To discuss the combined use of selective epidural steroid injection (ESI) and spinal manipulative therapy (SMT) in treating recalcitrant lumbar radiculopathy. CLINICAL FEATURES: In a first case, a patient suffered from numbness and pain in an S1 dermatome distribution 6 months after undergoing lumbar discectomy. Clinical correlation with advanced imaging led to the diagnosis of L5 intervertebral disc (IVD) syndrome with peridural scar formation. In a second case, a patient suffered from low-back and right-leg pain of 9 months' duration. Various forms of conservative treatment were not effective. A diagnosis of L4 IVD syndrome with radiculopathy was made. INTERVENTION AND OUTCOME: The first patient received conventional treatments, including physical therapy, SMT, fluoroscopically guided ESI and oral medications, with consistent but short-lived response. A team consisting of an anesthesiologist (dedicated spinal injectionist) and chiropractor performed manipulation under epidural anesthesia (MUEA) with corticosteroid injection. Follow-up at 60 days showed marked improvement in visual analogue scale, pain drawing and Oswestry pain and disability index. The second patient received all of the same conventional care except ESI before the combined procedure. The patient underwent MUEA, followed up with eight sessions of stretching and manipulation over the ensuing 3 wk. At 45 days after the combined procedure, the patient had a negative SLR (previously positive at 70 degrees), no leg pain and a marked reduction in back pain. CONCLUSION: This article discusses an integrated procedure that combines two standard treatments that may act synergistically. Our positive results are consistent with other reports, both published and anecdotal. The technique of MUEA warrants further investigation by the health care industry.

Videofluoroscopic assessment in children with severe cerebral palsy presenting with dysphagia.

In this study 16 patients with severe spastic cerebral palsy with an age range between 6 months and 16 years were examined using videofluoroscopy and a modified barium meal. All patients were slow, inefficient eaters. Silent aspiration was demonstrated in five cases. The latter five patients demonstrated a delayed swallow reflex but there was little correlation between aspiration and the oral phase of deglutition. Our data confirms the impression that early diagnostic workup including videofluoroscopy is helpful in managing the feeding difficulties in these children, and may prevent chronic aspiration and malnutrition.

Risk factors for death and emergency transfer in acute and subacute inpatient rehabilitation.

OBJECTIVES: To compare the risk of death or emergency transfer (ET) to an acute care hospital for acute and subacute rehabilitation inpatients, to identify risk factors, and to determine whether the risk factors vary by level of care. DESIGN: Proportional hazards regression analysis of retrospective cohort data. Explanatory variables included level of care, age, sex, medical stability at admission, and diagnosis. SETTING: An acute inpatient rehabilitation hospital and a skilled nursing facility-based subacute rehabilitation program. PATIENTS: Patients were selected from a database of all acute and subacute inpatients discharged between January 1992 and August 1994 (N = 4,755). Readmissions and pediatric patients were excluded (n = 896). Patients who had complete data (n = 3,185) were included in the survival analysis; a separate univariable analysis was performed for patients who lacked complete data (n = 674). OUTCOME MEASURE: Rate of death or emergency transfer during rehabilitation. RESULTS: The overall risk was greater for subacute patients than for acute inpatients, 20.6% vs 11.6%, odds ratio = 2.0, CI = 1.6 to 2.5. The survival analysis indicated that age, level of care, sex, and stability were associated with the risk of death or emergency transfer (2.1 < or = zeta < or = 4.7; p < .05 for each). However, the difference in risk between subacute and acute care was greatest among younger patients. CONCLUSIONS: Careful consideration of risk factors is critical for proper assignment of patients to rehabilitation levels of care. However, research is needed to test these findings in other settings and to improve identification of high-risk patients.

Household structure and poverty.

"This paper proposes a method for controlling for compositional factors in the measurement of poverty. The method is based on the notion of 'direct standardisation', used extensively in the field of demography.... With this class of standardised measures, it [is] possible to examine underlying differences in poverty while controlling for compositional factors known to be correlated with the incidence and intensity of poverty. The method is illustrated by examining the relationship between household structure and poverty in seven European countries: France, Germany, Italy, Luxembourg, Netherlands, Poland and Great Britain. The data are centered around 1985 and form part of the Luxembourg Income Study." (SUMMARY IN FRE AND ITA)

Entry to lone parenthood: an analysis of marital dissolution in Great Britain.

"This paper examines some...socio-economic determinants of lone parenthood in Great Britain, in an attempt to understand further the reasons behind the rapid growth in lone parenthood. Since divorce and separation are the major 'causes' of lone parenthood, this paper focuses on the determinants of marital dissolution among women with dependent children. The empirical analysis is guided by hypotheses suggested by the 'economic theory of marriage'. Hazard regression equations are estimated with data collected in the 1980 Women and Employment Survey...." (SUMMARY IN FRE AND ITA)

Immigration policy and immigrant quality: empirical evidence from Canada.

"This paper examines the earnings of foreign-born and native-born men [in Canada] in an attempt to evaluate whether the decline in the quality [based on earnings] of Canadian immigrants is related to changes in the country-of-origin mix and the class (type) mix of immigrants....The analysis consists of two parts. The first part is based on individual data on earnings and socio-economic characteristics collected in the 1971 and 1986 Canadian Censuses.... In the second part of the analysis, additional regression equations are estimated, pertaining to the period 1968 to 1985, that relate these Census-based measures of immigrant quality to the country-of-origin and class mix of immigrants." The impact of changes brought about by the 1967 restructuring of the Canadian immigration system is analyzed.

Case report: pararenal extramedullary haematopoietic tissue--an unusual manifestation of myelofibrosis.

The case of a 41-year-old man with myelofibrosis who presented with anaemia and splenomegaly is described. Ultrasound examination revealed several multiple circumscribed hypoechoic masses adjacent to both kidneys. The lesions were confirmed by computed tomography (CT) and biopsy of them revealed extramedullary haematopoietic tissue.

Parental education and child mortality in Burundi.

This paper examines the relationship between parental education and child mortality in Burundi using data collected in the 1987 Demographic and Health Survey. Proportional hazards models are estimated to examine this relationship, while holding constant other known child mortality determinants. Parental education proves to be a key factor in explaining differences in child mortality, the effect of maternal education being particularly strong compared to paternal education.

PIP: Data collected in Burundi as part of the 1987 Demographic and Health Survey confirm an inverse relationship between parental education and child mortality that persists even when a variety of socioeconomic factors are controlled. Burundi is characterized by low levels of educational attainment (80% of women have never attended school and 65% are illiterate) and high child morality (185.5/1000 live births in 1977- 86). There were 8895 births to the 3970 respondents in the 1987 survey, and 1415 (16%) of these children had died by their 5th birthday. Cox's proportional hazards model was used to assess the effect of maternal education on child mortality. Control variables included father's education, mother's age at time of birth, rural-urban residence, region, child's gender, period of birth, and length of the preceding birth interval. The relative risk of a child death was 0.43 among mothers with a secondary education and 0.90 for those with a primary education compared to a baseline value of 1.0 for those with no education. Paternal education demonstrated the same effect, but was not as significant as maternal education. A surprising finding was the unimportance of birth order, when demographic and socioeconomic variables were held constant, to child survival status. Other variables that conferred a lower (although not as significant) child mortality risk were urban residence, maternal age 20-34 years, birth between 1983-1987, and birth intervals exceeding 2 years.

The duration of lone parenthood in Great Britain.

PIP: Proportional hazards model analyses were conducted to examine the duration of lone parenthood among British women in 1980. Marital, demographic, and employment histories for 5320 women were collected from the Women and Employment Survey. A distinction is made between never married and previously married lone parents. Variables that affect the remarriage rate are occupation in last job before 1st birth, number of children at time of marital dissolution, age of youngest child at marital dissolution, period of marital dissolution, age at time of marital dissolution, duration of 1st marriage, work experience at end of 1st marriage, employment some time in the 12 months prior to marital dissolution, and highest educational qualifications. Characteristics that change over time and variables that pertain to the economic environment are also included. The statistical approach was to 1st build a general model with all the detailed variables, current employment status variables, and the macro environmental variables. In this model only women's real wages and real welfare benefits had statistical significance. Further refinements in the model were then made. The log of real welfare benefits as the only macro variable included in the specification revealed a positive and statistically significant relationship to the remarriage rate (x2=1.16). When the log of real wage is included, it has a negative effect which is statistically insignificant (x2=1.25). When both are included in a model, both are significant with opposite signs. The interpretation is that when women earn more in employment, they are less likely to remarry and remain lone parents longer. The duration of lone parenthood has the strongest association with the age of the woman. The type of job she had before becoming a mother and whether she had a job in the year prior to the dissolution of her marriage are strongly associated with the duration of lone parenthood for those previously married mothers. Results also suggest that lone mothers with poorer economic conditions remain lone parents longer. After the Divorce Reform Act, the number of people reentering the marriage market increased and previously married mother's duration of lone parenthood shortened. For previously married mothers, higher welfare payments directly or indirectly prolong the length of lone parenthood.^ieng

Bovine leukosis virus transmission with mouthparts from Tabanus abactor after interrupted feeding.

A successful attempt was made to mechanically transmit bovine leukosis virus (BLV) from a BLV-infected cow with a normal lymphocyte count to sheep by inoculation with horse fly (Tabanus abactor) mouthparts. After interrupted natural feeding, horse flies were anesthetized with CO2. Mouthparts were severed and pooled into a tissue grinder containing medium. Five inocula containing the mouthparts of 10 flies each, and 5 inocula containing the mouthparts of 20 flies each, were prepared and inoculated SC in the right axilla of 10 BLV antibody-negative sheep. Five additional sheep served as controls. Serum samples were collected at 2-week intervals and tested by agar gel immunodiffusion for BLV antibodies. One sheep injected with 20 mouthparts developed antibodies to BLV at 10 weeks after inoculation. Six months after inoculation with fly mouthparts, 1 BLV antibody-negative sheep was randomly selected from each treatment group and injected, in the left axilla, with 3 ml of blood from the donor cow to confirm susceptibility of the sheep. All 3 sheep developed antibodies to BLV within 4 weeks.

Identification of horse flies (Diptera: Tabanidae) by analysis of cuticular hydrocarbons.

Thin-layer chromatography of the cuticular lipids of horse flies from Oklahoma revealed that hydrocarbon was the major lipid class present. The hydrocarbon fraction was composed of n-alkanes and methyl branched alkanes with only a small amount of alkenes present. Gas chromatography of the isolated cuticular hydrocarbons from a single species, Tabanus abactor Philip, showed no major differences in the profiles between individuals or between the sexes. Analysis of extracts of fresh, frozen, and pinned specimens yielded nearly identical hydrocarbon profiles. Profiles of several species were examined and found to be unique for each. Three species with similar morphological characteristics and similar geographical ranges. Tabanus abdominalis F., T. limbatinevris Macquart, and T. sulcifrons Macquart, were differentiated easily by comparison of the hydrocarbon profiles.

Fecundity of partially engorged female Dermacentor albipictus (Acari: Ixodidae) removed by cattle grooming.

Eight Hereford heifer calves were infested 28 times over a 64-d period with approximately 49,560 Dermacentor albipictus (Packard) larvae per calf. The fecundity of partially engorged and small, fully engorged female ticks, prematurely removed by grooming behavior of the calves, were compared. A total of 3,532 females of various engorged weights was collected from all calves, resulting in a mean female tick yield of 1.78% based on the number of larvae used for all infestations. The ratio of partially to fully engorged females was 1:16. Female oviposition success was 96%. The mean (+/- SE) values for female weight, number of larvae, and percentage larval eclosion of 50 partially engorged females that ranged in weight from 54 to 397 mg was 174 +/- 99, 1,272 +/- 931 and 85 +/- 14, respectively. The correlation between preoviposition weight and number of larvae from partially engorged females was highly significant (r = 0.95, P less than 0.0001). A prediction model (Y = -354.6 + 9.07X) showed that the preoviposition weight of partially engorged females and larval fecundity from a separate study was highly correlated (r = 0.92, P less than 0.0001). There was no significant difference between mean values of larval numbers and percentage eclosion for partially engorged and small, fully engorged females of similar weight.

Welfare benefits and the duration of single parenthood.

PIP: The authors examine the contention that the provision of welfare benefits to single parents increases the number of single parents and the duration of single parenthood. Data are from the Women and Employment Survey, which collected marital, childbearing, and employment data from 5,320 women aged 16-59 in the United Kingdom in 1980. The results indicate that welfare benefits exercise no significant effect on the duration of single parenthood.^ieng

Population estimation of the horse fly, Tabanus abactor (Diptera: Tabanidae), in northcentral Oklahoma.

A mark-recapture technique was used to estimate daily populations of host-seeking Tabanus abactor Philip. Daily population estimates were calculated for 31 and 37 d for areas of 2.1 km2 and 4.6 km2 for 1982 and 1983, respectively. In 1982, population estimates ranged from 22,767 to 2,125,322 flies/2.1 km2 per d with a mean of 467,277 flies/d. In 1983, population estimates ranged from 48,962 to 2,794,389 flies/4.6 km2 per d with a mean of 759,616 flies/d. The estimated average number of host-seeking females per hectare was 2,225 (0.22 flies/m2) and 1,651 (0.17 flies/m2) for 1982 and 1983, respectively. Although daily population estimates fluctuated greatly, primarily because of fluctuation in recapture rates, seasonal trends during both years were similar. The estimates calculated in this study appear to be representative of the population of T. abactor in northcentral Oklahoma based on previous studies determining seasonal abundance.