Direct and correlated responses to artificial selection on male mating frequency in the stalk-eyed fly Cyrtodiopsis dalmanni

Traditionally it was thought that fitness-related traits such as male mating frequency, with a history of strong directional selection, should have little additive genetic variance and thus respond asymmetrically to bidirectional artificial selection. However, recent findings and theory suggest that a balance between selection for increased male mating frequency and opposing selection pressures on physiologically linked traits will cause male mating frequency to have high additive genetic variation and hence respond symmetrically to selection. We tested these hypotheses in the stalk-eyed fly, Cyrtodiopsis dalmanni, in which males hold harems comprising many females and so have the opportunity to mate at extremely high frequencies. We subjected male stalk-eyed flies to artificial selection for increased ('high') and decreased ('low') mating frequency in the presence of ecologically realistic, high numbers of females. High line males mated significantly more often than control or low line males. The direct response to selection was approximately symmetric in the high and low lines, revealing high additive genetic variation for, and no significant genetic constraints on, increased male mating frequency in C. dalmanni. In order to investigate trade-offs that might constrain male mating frequency under natural conditions we examined correlated responses to artificial selection. We measured accessory gland length, testis length and eyespan after 7 and 14 generations of selection. High line males had significantly larger accessory glands than low line males. No consistent correlated responses to selection were found in testis length or eyespan. Our results suggest that costs associated with the production and maintenance of large accessory glands, although yet to be identified, are likely to be a major constraint on mating frequency in natural populations of C. dalmanni.

The relationship between measures of patient satisfaction and enablement and professional assessments of consultation competence

The authors examined the extent of the relationship between a Consultation satisfaction questionnaire and Patient enablement instrument scores and professionally assessed consultation competence scores of senior medical students. Three analyses were performed: (i) linear regression with mean overall competence score as response variable; (ii) sensitivity and specificity calculations using patient scores to classify competence; (iii) a repeated measures model with consultation-specific competence score as response variable. One hundred and nineteen students and 388 patients took part. Consultation satisfaction and enablement scores were weakly correlated with overall and consultation specific competence scores (correlation coefficient 0.16 to 0.44). 'Satisfaction with professional care' had a sensitivity of 0.68, specificity of 0.72 and positive and negative predictive values of 0.32 and 0.92 respectively. It is concluded that patient and professional assessments may complement, but do not replace, each other. Levels of patient satisfaction should not be used as proxy measures of the quality of consultation competence.

Are audits wasting resources by measuring the wrong things? A survey of methods used to select audit review criteria

OBJECTIVES

This study measured the extent to which a systematic approach was used to select criteria for audit, and identified problems in using such an approach with potential solutions.

DESIGN

A questionnaire survey using the Audit Criteria Questionnaire (ACQ), created, piloted, and validated for the purpose. Possible ACQ scores ranged from 0 to 1, indicating how systematically the criteria had been selected and how usable they were.

SETTING

A stratified random sample of 10 audit leads in each of 83 randomly selected NHS trusts and all practices in each of 11 randomly selected primary care audit group areas in England and Wales.

PARTICIPANTS

Audit leads of ongoing audits in each organisation in which a first data collection had started less than 12 months earlier and a second data collection was not completed.

MAIN OUTCOME MEASURES

ACQ scores, problems identified in the audit criteria selection process, and solutions found.

RESULTS

The mean ACQ score from all 83 NHS trusts and the 11 primary care audit groups was 0.52 (range 0.0-0.98). There was no difference between mean ACQ scores for criteria used in audits on clinical (0.51) and non-clinical (0.52) topics. The mean ACQ scores from nationally organised audits (0.59, n=33) was higher than for regional (0.51, n=21), local (0.53, n=77), or individual organisation (0.52, n=335) audits. The mean ACQ score for published audit protocols (0.56) was higher than for locally developed audits (0.49). There was no difference in ACQ scores for audits reported by general practices (0.49, n=83) or NHS trusts (0.53, n=383). Problems in criteria selection included difficulties in coordination of staff to undertake the task, lack of evidence, poor access to literature, poor access to high quality data, lack of time, and lack of motivation. Potential solutions include investment in training, protected time, improved access to literature, support staff and availability of published protocols.

CONCLUSIONS

Methods of selecting review criteria were often less systematic than is desirable. Published usable audit protocols providing evidence based review criteria with information on their provenance enable appropriate review criteria to be selected, so that changes in practice based on these criteria lead to real improvement in quality rather than merely change. The availability and use of high quality audit protocols would be a valuable contribution to the evolution of clinical governance. The ACQ should be developed into a tool to help in selecting appropriate criteria to increase the effectiveness of audit.

Expert consensus on the desirable characteristics of review criteria for improvement of health care quality

OBJECTIVES

To identify the desirable characteristics of review criteria for quality improvement and to determine how they should be selected.

BACKGROUND

Review criteria are the elements against which quality of care is assessed in quality improvement. Use of inappropriate criteria may impair the effectiveness of quality improvement activities and resources may be wasted in activities that fail to facilitate improved care.

METHODS

A two round modified Delphi process was used to generate consensus amongst an international panel of 38 experts. A list of 40 characteristics of review criteria, identified from literature searches, was distributed to the experts who were asked to rate the importance and feasibility of each characteristic. Comments and suggestions for characteristics not included in the list were also invited.

RESULTS

The Delphi process refined a comprehensive literature based list of 40 desirable characteristics of review criteria into a more precise list of 26 items. The expert consensus view is that review criteria should be developed through a well documented process involving consideration of valid research evidence, possibly combined with expert opinion, prioritisation according to health outcomes and strength of evidence, and pilot testing. Review criteria should also be accompanied by full clear information on how they might be used and how data might be collected and interpreted.

CONCLUSION

The desirable characteristics for review criteria have been identified and will be of use in the development, evaluation, and selection of review criteria, thus improving the cost effectiveness of quality improvement activities in healthcare settings.

Expert consensus on the desirable characteristics of review criteria for improvement of health care quality

OBJECTIVES

To identify the desirable characteristics of review criteria for quality improvement and to determine how they should be selected.

BACKGROUND

Review criteria are the elements against which quality of care is assessed in quality improvement. Use of inappropriate criteria may impair the effectiveness of quality improvement activities and resources may be wasted in activities that fail to facilitate improved care.

METHODS

A two round modified Delphi process was used to generate consensus amongst an international panel of 38 experts. A list of 40 characteristics of review criteria, identified from literature searches, was distributed to the experts who were asked to rate the importance and feasibility of each characteristic. Comments and suggestions for characteristics not included in the list were also invited.

RESULTS

The Delphi process refined a comprehensive literature based list of 40 desirable characteristics of review criteria into a more precise list of 26 items. The expert consensus view is that review criteria should be developed through a well documented process involving consideration of valid research evidence, possibly combined with expert opinion, prioritisation according to health outcomes and strength of evidence, and pilot testing. Review criteria should also be accompanied by full clear information on how they might be used and how data might be collected and interpreted.

CONCLUSION

The desirable characteristics for review criteria have been identified and will be of use in the development, evaluation, and selection of review criteria, thus improving the cost effectiveness of quality improvement activities in healthcare settings.

Phylogenetic analysis of sexual dimorphism and eye-span allometry in stalk-eyed flies (Diopsidae)

Eye stalks and their scaling relationship with body size are important features in the mating system of many diopsid species, and sexual selection is a critical force influencing the evolution of this exaggerated morphology. Interspecific variation in eye span suggests there has been significant evolutionary change in this trait, but a robust phylogenetic hypothesis is required to determine its rate and direction of change. In this study, the pattern of morphological evolution of eye span is assessed in a phylogenetic framework with respect to its function in the sexual system of these flies. Specifically, we examine within the family Diopsidae the pattern of increase and decrease in sexual dimorphism, the morphological coevolution of eye span between males and females, and the evolutionary flexibility of eye-span allometry. Based on several different methods for reconstructing morphological change, results suggest a general pattern of evolutionary flexibility, particularly for eye-span allometry. Sexual dimorphism in eye span has evolved independently at least four times in the family and this trait also has undergone several reductions within the genus Diasemopsis. Despite most species being dimorphic, there is a strong phylogenetic correlation between males and females for mean eye span. The coevolution between the sexes for eye-span allometry, however, is significantly weaker. Overall, eye-span allometry exhibits significantly more change on the phylogeny than the other morphological traits. The evolutionary pattern in eye-span allometry is caused primarily by changes in eye-span variance. Therefore, this pattern is consistent with recent models that predict a strong relationship between sexual selection and the variance of ornamental traits and highlights the significance of eye-span allometry in intersexual and intrasexual signaling.

Phylogenetic utility of different types of molecular data used to infer evolutionary relationships among stalk-eyed flies (Diopsidae)

A phylogenetic hypothesis of relationships among 33 species of stalk-eyed flies was generated from a molecular data set comprising three mitochondrial and three nuclear gene regions. A combined analysis of all the data equally weighted produced a single most-parsimonious cladogram with relatively strong support at the majority of nodes. The phylogenetic utility of different classes of molecular data was also examined. In particular, using a number of different measures of utility in both a combined and separate analysis framework, we focused on the distinction between mitochondrial and nuclear genes and between faster-evolving characters and slower-evolving characters. For the first comparison, by nearly any measure of utility, the nuclear genes are substantially more informative for resolving diopsid relationships than are the mitochondrial genes. The nuclear genes exhibit less homoplasy, are less incongruent with one another and with the combined data, and contribute more support to the combined analysis topology than do the mitochondrial genes. Results from the second comparison, however, provide little evidence of a clear difference in utility. Despite indications of rapid divergence and saturation, faster-evolving characters in both the nuclear and mitochondrial data sets still provide substantial phylogenetic signal. In general, inclusion of the more rapidly evolving data consistently improves the congruence among partitions.

Phylogenetic analysis of the repleta species group of the genus Drosophila using multiple sources of characters

The species in the repleta group of the genus Drosophila have been placed into five subgroups-the mulleri, hydei, mercatorum, repleta, and fasciola subgroups. Each subgroup has been further subdivided into complexes and clusters. Extensive morphological and cytological analyses of the members of this species group have formed the foundation for the proposed relationships among the members of the repleta species group. Fifty-four taxa, including 46 taxa belonging to the repleta species group, were sequenced for fragments of four genes-16S ribosomal DNA (16S), cytochrome oxidase II (COII), and nitrogen dehydrogenase 1 (ND1) of the mitochondrial genome and a region of the hunchback (hb) nuclear gene. We also generated a partial data set of elongation factor 1-alpha (Ef1alpha) sequences for a subset of taxa. Our analysis used both DNA characters and chromosomal inversion data. The phylogenetic hypothesis we obtained supports many of the traditionally accepted clades within the mulleri subgroup, but the monophyly of taxonomic groups outside of this subgroup appears not to be supported. Phylogenetic analysis revealed one well-supported, highly resolved clade that consists of closely related members of the mulleri and buzzatii complexes. The remaining taxa, a wide assortment of taxonomic groups, ranging from members of other species groups to members of several subgroups and members of three species complexes from the mulleri subgroup are found in poorly supported arrangements at the base of the tree.

Assessing the relative contribution of molecular and morphological characters in simultaneous analysis trees

We examined the contribution of morphological and molecular character information for 15 systematics studies in which these two kinds of data were used in combined or simultaneous analyses. Assessment of the disagreement between these data sources, as measured by the incongruence length difference, reveals substantial conflict for the studies surveyed. In addition, the partitioned Bremer support was used to measure the degree of support provided by each data partition when analyzed together. Despite the significant incongruence found for nearly half the studies, the PBS indices suggest both types of data contribute positively to the combined analyses and that, when standardized by the number of phylogenetically informative characters, morphology data generally provide equal or greater support than do the molecular data. This result, combined with the fact that morphological characters generally exhibit higher consistency, indicates that this source of character information continues to be useful in systematics studies despite the increasing volume of available molecular data.

Multiple sources of character information and the phylogeny of Hawaiian drosophilids

Relationships among representatives of the five major Hawaiian Drosophila species groups were examined using data from eight different gene regions. A simultaneous analysis of these data resulted in a single most-parsimonious tree that (1) places the adiastola picture-winged subgroup as sister taxon to the other picture-winged subgroups, (2) unites the modified-tarsus species group with flies from the Antopocerus species group, and (3) places the white-tip scutellum species group as the most basal taxon. Because of the different gene sources used in this study, numerous process partitions can be erected within this data set. We examined the incongruence among these various partitions and the ramifications of these data for the taxonomic consensus, prior agreement, and simultaneous analysis approaches to phylogenetic reconstruction. Separate analyses and taxonomic consensus appear to be inadequate methods for dealing with the partitions in this study. Although detection of incongruence is possible and helps elucidate particular areas of disagreement among data sets, separation of partitions on the basis of incongruence is problematic for many reasons. First, analyzing all genes separately and then either presenting them all as possible hypotheses or taking their consensus provides virtually no information concerning the relationships among these flies. Second, despite some evidence of incongruence, there are no clear delineations among the various gene partitions that separate only heterogeneous data. Third, to the extent that problematic genes can be identified, these genes have nearly the same information content, within a combined analysis framework, as the remaining nonproblematic genes. Our data suggest that significant incongruence among data partitions may be isolated to specific relationships and the "false" signal creating this incongruence is most likely to be overcome by a simultaneous analysis. We present a new method, partitioned Bremer support, for examining the contribution of a particular data partition to the topological support of the simultaneous analysis tree.

Studies on a primaquine-tolerant strain of Plasmodium vivax from Brazil in Aotus and Saimiri monkeys

A nonimmune American acquired an infection of Plasmodium vivax Type 1 malaria in Brazil in 1994. After returning to the U.S.A., he had a primary attack followed by 3 relapses. The primary attack and first 2 relapses were treated with a standard regimen of chloroquine, followed by 14 days of primaquine (15 mg/day). Following the third relapse, the primaquine treatment was extended to 28 days. No further relapses occurred. The lack of response to primaquine by this strain may recommend it as a suitable candidate for chemotherapeutic study if it can be adapted to an animal model. Anopheles quadrimaculatus mosquitoes infected by feeding on the patient during the first relapse were used to establish the strain in Aotus and Saimiri monkeys. Monkeys supported well the development of long-lasting parasitemia. Anopheles freeborni, Anopheles stephensi, and Anopheles gambiae mosquitoes were readily infected by feeding on the monkeys and by membrane feeding on diluted blood. Monkey-to-monkey transmission was obtained via the bites of infected mosquitoes and the intravenous injection of sporozoites dissected from salivary glands. This parasite is designated as the Brazil I/CDC strain of P. vivax.

Confounders of auscultatory blood pressure measurement

The appropriate use of any test requires the clinician to appreciate that test's limitations. By recognizing the potential confounders of the auscultatory assessment of blood pressure, the clinician minimizes the likelihood of enacting therapeutic decisions based on inaccurate data. When approaching the treatment of a hypertensive patient, several points should be kept in mind. First, the measurement of persistent and severe hypertension in a patient receiving treatment who describes symptoms of orthostatic hypotension with apparently adequate standing blood pressure or who lacks corroborating retinal, echocardiographic, or electrocardiographic signs of hypertension should raise the concern of pseudohypertension or a white-coat response. Similarly, when one finds a normal or near-normal systolic blood pressure in a patient with a clinical picture consistent with severe hypertension, one should make a directed effort to look for an unrecognized auscultatory gap. Second, marked discrepancies in measurements as obtained by different operators or in different settings should raise concern of the white-coat response or methodologic errors by one operator, such as undercuffing, excessive pressure on the head of the stethoscope, rapid deflation of the cuff, or use of different arms. In treating hypertension in even the minimally obese patient, a special point must be made that an adequate size cuff be used for all blood pressure determinations. Third, when blood pressure is determined with the patient in any but the satndardized back-and-arm-supported seated position described above, the clinician should acknowledge the possibility that the position may alter the patient's classification. Fourth, the diagnosis and management of hypertension requires multiple measurements of blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Heterogeneous length and in-series arrangement of orbicularis oculi muscle: individual myofibers do not extend the length of the eyelid

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Aqueous dynamics in exfoliation syndrome

Eighteen untreated patients with unilateral exfoliation syndrome without glaucoma were studied with regard to differences in aqueous dynamics between the affected and unaffected fellow eyes. Additionally, both eyes of the patients with exfoliation were compared to the eyes of 18 age-matched and gender-matched control subjects. Intraocular pressure was significantly higher (13.9 +/- 3.0 mm Hg [mean +/- standard deviation]) in the affected compared with the unaffected eyes (12.2 +/- 2.5 mm Hg), but no difference in aqueous humor flow was detected when eyes in the three groups were compared (affected eyes, 2.40 +/- 0.60 microliter/min; unaffected eyes, 2.40 +/- 0.65 microliter/min; control eyes, 2.61 +/- 0.60 microliter/min). Anterior chamber volumes were significantly smaller in affected (122 +/- 37 microliters) and unaffected eyes (121 +/- 37 microliters) of the patients with exfoliation compared with the eyes of the control subjects (145 +/- 30 microliters). Apparent resistance was higher in the eyes with exfoliation (6.5 +/- 1.9 min mm Hg/microliters) compared with both unaffected (5.4 +/- 1.2 min mm Hg/microliters) and control groups (5.2 +/- 1.8 min mm Hg/microliters), although these differences were not statistically significant.

Familial polyposis coli: the spectrum of ocular and other extracolonic manifestations

Familial polyposis coli (FPC) is hereditary condition that conveys a virtual 100% risk for the development of colon cancer in the untreated patient. A total of 56 patients with FPC underwent complete ophthalmic examination. Highly pleomorphic pigmented retinal lesions were identified bilaterally in 52% (n = 29) and unilaterally in 14% (n = 8) of our subjects. In all, 33 patients had one or more extracolonic expressions associated with FPC, including desmoids, osteomas, epidermoid cysts, lipomas, fibromas, and upper gastrointestinal tract polyps. In 15 patients, pigmented fundus lesions were the only extracolonic manifestations. No significant association between eye findings and other extracolonic manifestations could be established. The presence or absence of pigmented fundus lesions was found to cluster within families. Pigmented fundus lesions are probably a variably penetrant expression of the polyposis gene and do not appear to be specifically associated with subgroups of inherited polyposis syndromes such as Gardner's syndrome.

Extracellular deposition of eosinophil major basic protein in orbital histiocytosis X

Although eosinophils are prominent in orbital lesions of patients with histiocytosis X (Langerhans' cell histiocytosis), little is known of their pathogenic significance in the disease. To determine whether eosinophils degranulate and deposit toxic proteins in orbital histiocytosis X, the authors examined lesions by indirect immunofluorescence for localization of the core granule protein (major basic protein) outside of eosinophils. Four patients with histiocytosis X were studied: three with eosinophilic granuloma and one with Hand-Schüller-Christian disease. Tissue eosinophilia was prominent in all specimens; striking extracellular deposition of eosinophil major basic protein was noted in three patients, and focal deposition was present in the fourth patient. Orbital specimens obtained at autopsy from patients without orbital disease were studied as control specimens; no tissue eosinophilia or deposition of eosinophil major basic protein was observed. These findings indicate that eosinophils likely degranulate in lesions of orbital histiocytosis X and may participate in the pathogenesis of the disease.

Ocular onchocerciasis and intensity of infection in the community. III. West African rainforest foci of the vector Simulium sanctipauli

The community pattern of ocular onchocerciasis is described for 11 villages from the forest area in Côte d'Ivoire where S. sanctipauli is the princial vector. An analytical method is applied which relates indices of ocular onchocerciasis with the Community Microfilarial Load (CMFL) and compares the results with the ocular onchocerciasis pattern found in the West African savanna. In spite of high transmission levels as estimated by entomological indices, the CMFLs were relatively low which complicated the characterization of the ocular disease pattern. Nevertheless, it could be shown that ocular onchocerciasis is less severe in the Sanctipauli forest than in the savanna, even after correction for differences in CMFL. The prevalence of onchocercal eye lesions and blindness were low and advanced sclerosing keratitis was completely absent. The differences are explained by presuming strain differences of the parasite Onchocerca volvulus. For given CMFLs the mean microfilarial loads in the eye were significantly lower than in the savanna which suggests that the parasite strain in the Sanctipauli forest is less invasive to the eye. Ocular microfilarial loads were too low to determine if the parasite is also less pathogenic to the eye, as has been concluded previously for foci of S. yahense, but this possibility cannot be excluded.

Late juvenile-onset Krabbe's disease

Krabbe's disease is an autosomal recessive leukodystrophy characterized by a lack of galactocerebroside beta-galactosidase activity. In contrast to the classic early infantile-onset form of Krabbe's disease, less recognized, late-onset variants exist. The authors present a case of late juvenile-onset Krabbe's disease, including the associated magnetic resonance imaging (MRI) findings. Most patients with late-onset Krabbe's disease present with visual loss due to optic atrophy. Associated gait abnormalities and parental consanguinity should increase the clinician's suspicion that a child may have late-onset Krabbe's disease. Because of the prolonged survival in late-onset Krabbe's disease, the recent development of bone marrow transplantation for these patient makes diagnosis of this disorder particularly important.

Progress in controlling the reinvasion of windborne vectors into the western area of the Onchocerciasis Control Programme in West Africa

Since vector control began in 1975, waves of Simulium sirbanum and S. damnosum s.str., the principal vectors of severe blinding onchocerciasis in the West African savannas, have reinvaded treated rivers inside the original boundaries of the Onchocerciasis Control Programme in West Africa. Larviciding of potential source breeding sites has shown that these 'savanna' species are capable of travelling and carrying Onchocerca infection for at least 500 km northeastwards with the monsoon winds in the early rainy season. Vector control has, therefore, been extended progressively westwards. In 1984 the Programme embarked on a major western extension into Guinea, Sierra Leone, western Mali, Senegal and Guinea-Bissau. The transmission resulting from the reinvasion of northern Côte d'Ivoire and Burkina Faso has been reduced by over 95%, but eastern Mali has proved more difficult to protect because of sources in both Guinea and Sierra Leone. Rivers in Sierra Leone were treated for the first time in 1989 and biting and transmission rates in Sierra Leone and Guinea fell by over 90%. Because of treatment problems in some complex rapids and mountainous areas, flies still reinvaded Mali, though biting rates were approximately 70% lower than those recorded before anti-reinvasion treatments started. It was concluded that transmission in eastern Mali has now been reduced to the levels required to control onchocerciasis.

Lacrimal gland ductule stones

Chronic unilateral conjunctivitis may be caused by various infectious, inflammatory, neoplastic, or mechanical conditions. Two patients with persistent unilateral conjunctivitis were cured after removal of dacryoliths from the palpebral lobe of the ipsilateral lacrimal gland. Although lacrimal gland ductular dacryoliths are rare, this entity should be included in the differential diagnosis of chronic unilateral conjunctivitis.

A community trial of ivermectin in the onchocerciasis focus of Asubende, Ghana. I. Effect on the microfilarial reservoir and the transmission of Onchocerca volvulus

A community trial of the microfilaricide ivermectin was undertaken in an isolated focus of hyperendemic savanna onchocerciasis in Ghana. One of the objectives was to determine the effect of mass treatment on the microfilarial reservoir and on the transmission of Onchocerciasis volvulus. Since 1978 the focus has been under entomological surveillance. This was intensified from 1 September 1987 till 11 February 1988 with daily vector collection and dissection of over 30,000 flies. A total of 14,991 people were treated with ivermectin on 7-10 October 1987. Skin snip surveys were done pre-treatment, and at two and four months after treatment. The mean skin microfilarial load in treated persons had fallen by more than 96% two months after treatment. During the next two months there was an increase in microfilaria loads which appeared to be faster than reported in the clinical trials. The total reservoir of skin microfilariae available for transmission had been reduced by an estimated 68%-78% two months after treatment. This was consistent with the entomological results which indicated a reduction in transmission of 65%-85% during the first three post-treatment months. The present study has shown for the first time that mass chemotherapy can significantly reduce onchocerciasis transmission. However, the remaining level of transmission was still unacceptably high and further studies are required to predict the long term impact of repeated mass treatment.

Experimental vertical transmission of Japanese encephalitis virus by Culex tritaeniorhynchus and other mosquitoes

Vertical transmission of Japanese encephalitis virus to the F1 adult stage was demonstrated in Culex tritaeniorhynchus, Cx. annulus, Cx. quinquefasciatus, and Armigeres subalbatus. Transmission to the F1 larval stage was demonstrated in Cx. pipiens, Aedes vexans, Ae. alcasidi, and A. flavus. In Cx. tritaeniorhynchus, vertical transmission rates (the percentage of parent females transmitting to progeny) varied (12-100%). Filial infection rates (the percentage of progeny infected) for a given mosquito virus combination were markedly affected by the interval of time between parental infection and oviposition, suggesting that vertical infection was not transovarial in nature but occurred at oviposition. Filial infection rates for Cx. tritaeniorhynchus also varied widely by family and, as measured in F1 larvae, rates in excess of 20% were observed in a family. Filial infection rates in Cx. tritaeniorhynchus F1 adults were about 4 times lower than those in larvae. Japanese encephalitis virus was sexually transmitted from male to female Cx. tritaeniorhynchus.

The quality initiative of the Royal College of General Practitioners

The Quality Initiative of the Royal College of General Practitioners was set up in 1983 to promote the methods of quality assurance to general practitioners, and to answer some of the concerns of Government about the quality of general practice. Many small projects have been carried out, and this paper describes several undertaken by one faculty of the College, including studies of paediatric surveillance, the care of the elderly, and peer review visits to some members practices. General practitioners are now more positive about quality assurance, but the political debate about the future of primary care in the United Kingdom continues.

Hyperpigmented lesions of the retinal pigment epithelium in familial adenomatous polyposis

Ophthalmic examinations were performed on 56 patients with validated familial adenomatous polyposis (FAP) for hyperpigmented defects of the retinal pigment epithelium. Such lesions were seen bilaterally in 29 patients (52%) and unilaterally in 8 patients (14%). Of the 56 patients, 33 had one or more of the extracolonic expressions associated with Gardner syndrome. We found retinal lesions in 8 patients without any of the expressions of Gardner syndrome. No association was found between Gardner syndrome and the retinal lesions when these patients were compared to patients without any stigmata of Gardner syndrome, nor was any significant association found when each of the expressions was compared individually with the presence of the pigmented retinal lesions. The presence or absence of eye findings were seen to cluster within families. There was no association with sex. Fundus lesions are apparently a variable expression of the FAP gene and are not specifically associated with Gardner syndrome.

Stage-selective inhibition of rodent malaria by cyclosporine

The relative susceptibility of different developmental stages of Plasmodium berghei to cyclosporine was investigated in vivo. Within 12 h of receiving a single 25-mg/kg (body weight) dose of cyclosporine, mice with patent P. berghei infections uniformly exhibited a rapid fall in asexual parasite stages. Initially, ring forms and mature schizonts disappeared. Subsequently, trophozoites disappeared between 21 and 24 h, whereas gametocytes persisted for 36 h. In contrast, when cyclosporine was administered to mice 1 day before inoculation (100 mg/kg) with P. berghei sporozoites and for 2 consecutive days after inoculation (25 mg/kg), infections developed normally. When mice with patent infections were placed on prolonged cyclosporine therapy (25 mg/kg per day), parasitemia initially disappeared but often recrudesced. Recrudescent parasites were frequently resistant to cyclosporine (Csr). The Csr phenotype remained stable after serial passage of parasites in mice and after transmission through Anopheles stephensi mosquitoes, in which the capacity to produce oocysts was reduced. When infections of untreated mice were initiated with equal numbers of Csr and cyclosporine-susceptible (Css) parasites and then carried through two serial cycles of mosquito-to-mouse transmission without cyclosporine treatment, the Csr phenotype was lost. The results indicate that cyclosporine selectively inhibits asexual blood stages of P. berghei and favors the emergence of Csr parasites with diminished infectivity for mosquitoes.

Extraction of thromboxane B2 from urine using an immobilized antibody column for subsequent analysis by gas chromatography-mass spectrometry

This paper describes an antibody affinity (immunoaffinity) column which, in one step, extracts and sufficiently purifies urinary thromboxane B2 (TXB2) for quantitative analysis by high resolution gas chromatography-negative ion chemical ionization-selected ion monitoring-mass spectrometry (HRGC-NICI-SIM-MS). Polyclonal TXB2 antibody from rabbit was partially purified using immobilized Staphylococcus aureus Protein A. The purified IgG fraction was then immobilized using an N-hydroxysuccimidyl silica gel. The resulting matrix bound 570 ng TXB2 per ml of gel. TXB2 was quantitatively eluted with acetonitrile-water (19:1). Columns constructed from the gel could be used repeatedly since binding capacity was reconstituted using 0.01 M phosphate buffer (pH 7.4) with no apparent loss of activity. Using these columns, urinary TXB2 was sufficiently purified in one step such that in subsequent analysis by HRGC-NICI-SIM-MS interference free chromatograms were observed.

Onchocerciasis in Sudan: the distribution of the disease and its vectors

The distribution of onchocerciasis and its vectors in Sudan has been reviewed with special emphasis on the hyperendemic foci where there is serious visual handicap caused by the disease. These blinding foci lie primarily in the south-west of the country, along the rivers flowing north and east from the borders with Central African Republic and Zaire, though at least one such focus is known from the eastern part of the country close to the Ethiopian border. In the blinding foci, often small villages localized to short stretches of the rivers, ocular onchocerciasis is as severe as that found in any other African foci. Only the S. damnosum s.l. species complex has been implicated in disease transmission and only the two dangerous, morphologically similar, savanna cytospecies, S. damnosum s.s. and S. sirbanum, have been identified from breeding sites close to known onchocerciasis foci. Near to the Uganda and Zaire borders it is very likely that other, less anthropophilic, cytospecies occur. Different Onchocerca-Simulium complexes (different strains of parasite with different pathogenicities transmitted by different vector species) may be responsible for the different severities of disease found in the 3 main areas of onchocerciasis in North, East and South-West Sudan. The localized, focal distribution of the communities seriously blinded by onchocerciasis, suggests that a strategy of tackling the disease on a focus basis may prove optimal. A control scheme, planned to treat all the vector breeding sites with insecticide, as in West Africa, would receive extensive invasion from the Zaire/Congo River Basin and the headwaters of the White and Blue Niles in neighbouring countries. While some foci are situated beside major river rapids, with vector breeding only controllable by regular insecticide treatments, several foci have been identified as lying close to removable man-made objects which provide excellent breeding sites at certain water levels e.g. causeways. The destruction of such breeding sites should be considered since localized vector control may produce substantial reductions in onchocerciasis transmission.

Localized onchocerciasis vector control in the Bahr el Ghazal Region of South-Western Sudan. I. Precontrol

Over a two year period, onchocerciasis vector biting and transmission rates were recorded from 11 sites within a 40 km radius of Wau, in the Bahr El Ghazal Region of South-Western Sudan. These data provide the baseline on which the efficacy of localized vector control in the third year of the study, has been assessed (Baker and Abdelnur 1986). During 1018 collection days, 59,660 Simulium damnosum s.l. vectors were attracted to man, 41,548 of which were dissected. 2.8% of the dissected flies were infective with head L3 Onchocerca with a mean of 2.4 head L3s per fly and a maximum of 19. Larval collections revealed that only Simulium sirbanum and S. damnosum s.str. were breeding in the study area. The results were analyzed to show the hourly, seasonal and annual patterns of biting and transmission. These patterns were found to be remarkably similar in both years even though vector biting and transmission was 24-28% lower in the second year. The sites could be divided into two groups. Those with Annual Transmission Potentials (ATPs) over 1000 lay beside fast flowing, well wooded stretches of river and those with ATPs below 500 lay near rivers flowing slowly in a wide grassy plain. Blinding onchocerciasis had been recorded only from the first group.

Localized onchocerciasis vector control in the Bahr el Ghazal Region of South-Western Sudan. II. Control

Onchocerciasis vector breeding along 41 km of the Bussere River in the Wau Area of South-Western Sudan was controlled with temephos (Abate) insecticide for one annual transmission period. Vector biting and transmission was compared to the two years of precontrol data. Up to 70% reductions in vector biting and 80% reductions in transmission were recorded at sites with the highest precontrol levels. The flies invading in the control year (principally those invading from the south-west in the main part of the rainy season) were found to be much less infective - 2390 fly bites would be needed to transmit 100 larvae in the control year, compared to 1490 in the precontrol years. It was concluded that localized vector control could have a major impact on onchocerciasis transmission and that in this, and many other foci in Sudan, permanent reductions could be achieved by causeway removal and selective vegetation clearance.

Genetic variation for West Nile virus susceptibility in Culex tritaeniorhynchus

Mutant and geographical strains of Culex tritaeniorhynchus were compared for West Nile (WN) virus susceptibility by feeding on a high-titered blood-virus suspension. Eleven strains also were selected from 2-21 generations for an increase and/or a reduction of oral susceptibility using 90% and 10% infective virus doses, respectively. Only one of the 20 strains tested, e ma, was significantly less susceptible than the control strain. In the selection experiments, none of the strains showed a consistent decrease in susceptibility, but the Changa Manga II (CM) strain showed a sustained increase in susceptibility from generations F11-F21 when selection was discontinued. Reciprocal cross-matings and back-crosses were set up between the selected CM strain and two of the morphological mutant strains, e ma and re e ae, carrying homozygous recessive markers. The resulting progeny were tested for susceptibility to WN virus infection and the ability to replicate virus to high-titers after infection. These results suggest that the trait of increased susceptibility is dominant over resistance. The enhanced ability of infected mosquitoes to replicate WN virus showed partial dominance. Both of these traits appear to be polyfactorial, and are apparently associated with more than one chromosome in Cx. tritaeniorhynchus.

Induced chromosomal aberrations and linkage group-chromosome correlation in Anopheles stephensi

Genetic and cytogenetic investigations of 14 strains of Anopheles stephensi with induced chromosomal aberrations have resulted in the assignment of the three linkage groups to their respective chromosomes. In addition, the correlation between the ovarian polytene chromosomes and the mitotic chromosomes was demonstrated. Indirect evidence for the presence of heterochromatic segments in the chromosomal complement was found.

Linkage group III in the malaria vector, Anopheles stephensi

The linkage relationships among four loci in linkage group III of Anopheles stephensi Liston have been investigated. The data indicate that the sequence is sp-dp-Bl-Dl, and the observed recombination frequencies are as follows: sp-dp = 35.88 percent, dp-Bl = 19.48 percent, Bl-Dl = 21.77 percent, and sp-Dl = 77.13 percent.