bluuebunny/crossref_metadata_2025 huggingface dataset:
Preclinical aspects of lamivudine and famciclovir against hepatitis B virus
Authors: Shaw T. , Locarnini S. A.
Published: March 2003

Chemotherapy for chronic hepatitis B virus (HBV) infection is inherently difficult for a variety of reasons that are related to unusual features of both HBV replication strategy and host cell metabolism. Previous attempts to treat chronic HBV infection using nucleoside analogues have been almost universally disappointing, but several recently developed nucleoside analogues have been identified as potent, non‐toxic inhibitors of HBV replication. These fall into two broad categories: nucleosides having the ‘unnatural’L‐configuration, and deoxyguanosine analogues with modified‐sugar configurations, represented by lamivudine and penciclovir respectively. Both lamivudine and penciclovir (in its orally available form, famciclovir) have progressed to phase III clinical trials against chronic HBV infection, with promising preliminary results. However, chemotherapy for chronic HBV is necessarily long term, which increases the risks for development of viral resistance and cumulative toxicity. Such risks might be minimized by the use of appropriate drug combinations, rational selection of which requires knowledge of the pharmacokinetics and mechanisms of action of the individual agents. An appreciation of cellular deoxynucleoside metabolism and its regulation, the complexities of which are still emerging, is an indispensable aid to understanding the biological activities of deoxynucleoside analogues. The modes of action of lamividine and penciclovir, and how these two deoxynucleoside analogues may interact in vitro and in vivo as inhibitors of HBV replication, are examined here in the context of cellular deoxynucleoside metabolism.
Fulminant hepatitis in patients with chronic liver disease
Authors: O’Grady J.G.
Published: March 2003

The changing epidemiology of hepatitis A virus (HAV) in the UK has led to a decline in natural immunity against the virus. It is estimated that in the UK, HAV is responsible for 10%–20% of cases of liver failure, and an overall mortality rate of 0.1%. It is clear that certain factors predispose patients to more severe HAV disease and increased mortality, although the reasons for this have yet to be elucidated. The age at which infection occurs clearly influences the outcome, with the risk of severe hepatitis increasing sharply after the age of 40 years. Intravenous drug users, homosexual men, individuals with an excessive alcohol intake or patients with chronic liver disease are also at increased risk of severe disease. An analysis of data from King’s College Hospital was performed to determine the factors that influence the outcome or clinical course of HAV infection in at‐risk patients. Data compiled from 1991 to 1998 revealed 187 cases with confirmed HAV, 45 of whom developed severe hepatitis. Outcomes were varied, eight (17.7%) patients developed acute liver failure and two (4.4%) died.
Hepatitis C virus genotypes in a non‐cirrhotic Italian population with chronic hepatitis C: correlation with clinical, virological and histological parameters. Results of a prospective multicentre study
Authors: Saracco  , Sostegni  , Ghisetti  , Rocca  , Cariti  , Andreoni  , Tabone  , Roffi  , Calleri  , Ballaré  , Minoli  , Sartori  , Tappero  , Traverso  , Poggio  , Orani  , Maggi  , Rizzetto  ,   The North West Italian Hepatologic Group
Published: March 2003

To identify correlations between the distribution of hepatitis C virus (HCV) genotypes and demographic, pathological and virological parameters of HCV‐infected patients, we prospectively recruited 650 patients with biopsy‐proven chronic hepatitis C without histological aspects of cirrhosis; none had been treated with antiviral therapy. Data regarding gender, age, mode of HCV transmission, alanine aminotransferase (ALT) and HCV RNA levels, immunoglobulin M (IgM) anticore values, liver histology and histological activity were obtained from each patient and correlated on multivariate analysis with infecting HCV genotype. Fifty‐five per cent of the patients were infected with HCV genotype 1, 20% with HCV genotype 2, 18% with HCV genotype 3 and 7% with HCV genotype 4. Non‐transfusional HCV transmission, low ALT levels, IgM anticore reactivity and a low histological grading score were independent variables associated with HCV genotype 1. Older age, female gender, post‐transfusional transmission and a high histological grading score were related to HCV genotype 2, whilst younger age, history of current/previous drug abuse, high ALT values, low IgM anticore reactivity and high viraemic levels were associated with HCV genotype 3. History of illicit use of intravenous drugs and low HCV RNA levels were the only independent variables correlated with HCV genotype 4. Genotype 1 remains predominant in Italy but the prevalence of HCV genotypes is changing in relation to age and mode of transmission: Italian patients with HCV genotype 3 are younger and exhibit higher levels of ALT and HCV RNA than patients with other genotypes.
Recurrent hepatitis C after liver transplantation: clinical and therapeutical issues
Authors: Samuel  , Feray
Published: March 2003

Hepatitis C virus (HCV) reinfection after liver transplantation is almost constant, assessed by the persistence of HCV RNA in 90% of cases. Acute hepatitis appeared in 75% of patients at a median of 4 months’ post‐transplantation. The 5‐year actuarial rate of acute and chronic hepatitis on the graft is 75% and 60%, respectively. The rate of HCV cirrhosis on the graft is variable from 8 to 25% at 5 years. After transplantation, HCV viraemia is dramatically increased and correlates with the occurrence of acute hepatitis on the graft. Intrahepatic levels of HCV are high at the time of acute hepatitis, and decrease with constitution of chronic graft hepatitis lesions, implying an immunological response to the viral infection. A relationship between genotype 1b and the prevalence of HCV hepatitis on the graft has been suggested in European but not American series. The influence of the age of the recipient, quasispecies, viral compartmentalization, immunosuppressive treatment, and of HLA matching is being evaluated. The 5‐year patient survival is around 65‐80%. However, the occurrence of cirrhosis with a risk of graft failure may decrease the 10 and 15‐year patient survival. Attempts to give prophylactic post‐transplant antiviral treatment are under evaluation. Antiviral treatment of post‐transplant graft lesions with combination therapy interferon–ribavirin gave promising results but indications and duration of treatment should be evaluated.

In conclusion, HCV reinfection is frequent, but medium‐term survival is good. However, the long‐term graft and patient survival remains unknown, and efficient prevention and treatment of HCV graft is mandatory.
Doctor‐to‐patient transmission of viral hepatitis B: is it a problem, is there a solution?
Authors: Schalm Solko W. , Van Wijngaarden Jan K.
Published: March 2003

It is well‐established that hepatitis B may be transmitted from surgeons to their patients. Clear strategies are needed to reduce the risk of transmission whilst not discriminating unnecessarily against surgeons who may pose no risks to their patients. This review outlines the current position and provides a blueprint for action that may reduce the risks to patients whilst minimizing the impact on practising surgeons.
Comparative analysis of amino acid sequences from envelope proteins isolated from different hepatitis C virus variants: possible role of conservative and variable regions
Authors: Sobolev  , Poroikov  , Olenina  , Kolesanova  , Archakov
Published: March 2003

Sequences of the E1 and E2 envelope proteins of hepatitis C virus (HCV) (827 non‐identical items) were collected from available sources and aligned. Analysis of the alignment identified regions with different sequence variability. It was found that 33% and 50% of positions within E1 and E2, respectively, were highly conservative. Such conservation can be considered as the minimum for maintaining stability of the three‐dimensional structure and function of these proteins. Conserved cysteines in E1 and E2 (eight and 18 residues, respectively) were presumed to form intramolecular disulphide bonds. Both envelope proteins were predicted to contain 14 conservative glycosylation sites. Two additional glycosylation sites were predicted in 58% of E1 and 30% of E2 sequences within the corresponding regions. We describe the positions of six conservative regions in E1 and E2, which have several charged and aromatic residues known to participate frequently in protein–protein recognition. Peculiarities in the amino acid content of conservative fragments and putative differences in glycosylation were considered with regard to antigenic specificity and possible binding to surface structures of target cells. We also analysed the hypervariable region 1 (HVR1), located in the E2 protein. Aligned positions of HVR1 were described in relation to the maintenance of conformational stability and recognition of cell receptors.
Identification of a cellular protein specifically interacting with the precursor of the hepatitis B e antigen
Authors: Salhi S. , Messageot F. , Carlier D. , Jean‐Jean O. , Rossignol J.‐M.
Published: March 2003

In hepatitis B virus (HBV) the precore gene encodes a protein from which derives P22, the precursor of the mature secreted hepatitis B virus e antigen (HBeAg). Circumstantial evidences suggest that HBeAg and/or its precursor P22 are important for establishing persistent infection. Although P22 is essentially present in the secretory pathway, a substantial fraction has been found in the cytosol. In order to get new insights into the biological function of P22, we looked for cellular proteins which could strongly associate with this protein. Using immunoprecipitation studies on human cell extracts, we found that a non‐secreted cellular protein of about 32 kDa (P32) bound with a high specificity to P22. P32 associated neither with HBeAg nor with the viral core protein P21 which exhibits the same amino acids sequence as P22 but is N‐terminally shorter by 10 residues. We also demonstrated that this interaction depended on the presence of the P22 C‐terminal domain. Our data argues for a potential biological function of P22.
Apoptosis mediated by the Fas system in the fulminant hepatitis by hepatitis B virus
Authors: Rivero M. , Crespo J. , Fábrega E. , Casafont F. , Mayorga M. , Gomez‐Fleitas M. , Pons‐Romero F.
Published: March 2003

The pathogenesis of the fulminant hepatitis B is poorly understood and both viral factors and the hosts immune response play a role. Previous studies in liver tissues of patients with chronic hepatitis B showed overexpression of Fas antigen and this was correlated with the activity of the hepatitis. The present study was done to determine the role of Fas in fulminant hepatitis B and the virological characteristics of hepatitis B infection.

We studied three patients with fulminant hepatitis B. HBV‐DNA was detected by dot‐blot hybridization and polymerase chain reaction. The S and C gene were sequenced. Levels of serum soluble Fas antigen were detected by enzymoimmunoassays procedure. Apoptosis was determined by the TUNEL technique. Fas antigen expression was evaluated by a immunoperoxidase method. Ten healthy subjects acted as controls.

The three patients showed a high expression of Fas antigen particularly among infiltrating lymphocytes; in these areas we also found many cells with in situ DNA nick labelling signals in the nuclei of most viable hepatocytes. Serum levels of soluble Fas antigen were higher in patients with fulminant hepatitis B than in controls. No specific genome mutations of hepatitis B virus were found.

These data suggest that the Fas system involved in the liver injury of patients with fulminant hepatitis B.
Sequential analysis of hepatitis B virus core promoter and precore regions in cancer survivor patients with chronic hepatitis B before, during and after interferon treatment
Authors: Zampino R. , Marrone A. , Cirillo G. , Del Giudice E. Miraglia , Utili R. , Karayiannis P. , Liang T. J. , Ruggiero G.
Published: March 2003

We analysed the hepatitis B virus (HBV) core‐promoter (CP) and precore (PC) regions before, during and after interferon treatment in young Caucasian cancer survivors who had acquired HBV infection during chemotherapy for malignancies. Fourteen patients with chronic hepatitis B [hepatitis B e antigen (HBeAg) /HBV‐DNA positive] received α‐2a interferon (IFN), 5 MU/m2 t.i.w. for 12 months. HBV CP and PC region sequences were analysed following polymerase chain reaction (PCR) amplification. Sera from responders were studied at: T0 (before starting IFN), T1 [at alanine aminotransferase (ALT) peak preceding HBeAg seroconversion], T2 (at ALT normalization), T3 (at end of IFN) and T4 (at one year after IFN) and in nonresponders at time points T0, T3 and T4. Amplified HBV‐DNA was cloned and sequenced automatically. Six of 14 patients (43%) responded to IFN treatment. Five of the six (83%) responders displayed the double CP mutation A1762T/G1764A always in association with a T1753C change. None of the nonresponders showed these mutations at any time point. The G1896A change creating the PC stop codon mutation was never detected in any of the patients. In our cancer survivors, IFN‐induced HBeAg/anti‐HBe seroconversion appeared to correlate with CP mutations and was not influenced by previous chemotherapy. These mutations in addition to low HBV DNA levels and elevated ALT can be considered favourable factors of response to IFN‐induced anti‐HBe seroconversion.
Is investigation of hepatitis C virus NS5A gene heterogeneity a tool for predicting long‐lasting response to interferon therapy in patients with HCV‐1b chronic hepatitis?
Authors: Squadrito G. , Raffa G. , Restuccia T. , Pollicino T. , Brancatelli S. , Raimondo G.
Published: March 2003

summary. Nonstructural protein 5A (NS5A) of the hepatitis C virus (HCV) may repress the interferon (IFN)‐induced protein kinase R (PKR). High variability of different regions in the carboxy‐terminal half of NS5A implicated in the interaction with PKR (particularly the interferon sensitivity determining region (ISDR)) may be a predictor of response to IFN in patients infected with genotype 1b of HCV. We examined pretreatment serum samples from 17 HCV‐1b infected patients included in the same schedule of IFN therapy. Seven patients were a rare series of sustained responders (SR) with a post‐treatment follow‐up of 5–7 years, while ten were nonresponders (NR). The carboxy‐terminal half of the NS5A gene was amplified and directly sequenced in all 17 cases. In addition, the entire NS5A gene and the part of the HCV E2 gene coding for the hypervariable region 1 (HVR1) were amplified, cloned and sequenced in six cases (three NR and three SR). No difference in number and distribution of amino acid mutations was observed between isolates from SR and NR in any portion of the protein, including the ISDR region. Analysis of full length NS5A confirmed no difference between the two groups. The NS5A gene sequence was different among the six cases cloned although it appeared to be conserved in each individual patient independently of the quasispecies complexity evaluated through HVR1 examination. These data indicate that pretreatment analysis of theNS5A genomic variability has no value in predicting long‐lasting response to IFN therapy in HCV‐1b‐infected patients, and that the HCV NS5A gene has high quasispecies homology.
The role of lamivudine and predictors of mortality in severe flare‐up of chronic hepatitis B with jaundice
Authors: Chan H. L.‐Y. , Tsang S. W.‐C. , Hui Y. , Leung N. W.‐Y. , Chan F. K.‐L. , Sung J. J.‐Y.
Published: March 2003

summary. Patients with chronic hepatitis B (CHB) may develop severe disease exacerbations (flare) with jaundice, and some may progress to fulminant hepatic failure. Whether early administration of lamivudine can prevent liver failure and mortality is uncertain. We investigated the role of lamivudine treatment in severe hepatitis B virus (HBV) exacerbations. Consecutive patients presented with severe flare‐up of HBV (new onset of jaundice plus alanine aminotransferase greater than five times upper limit of normal) treated with lamivudine and historical controls who did not receive lamivudine were studied. All patients had no hepatic encephalopathy on admission. Univariate analysis and multivariate logistic regression were performed on various clinical and laboratory factors for the prediction of mortality. Twenty‐eight patients treated with lamivudine and 18 controls were identified. Overall, nine patients died and two other received liver transplants for fulminant hepatic failure. Six of 28 (21.4%) lamivudine‐treated patients vs five of 18 (27.8%) controls died or received a liver transplant (P=0.62). On multivariate analysis, platelet ≤143 × 10E9/L (odds ratio 22.4, 95% CI 1.8–281.6) and bilirubin > 172 μmol/L (odds ratio 18.4, 95% CI 1.5–228.5) were independent predictors of liver‐related mortality. The mortality of patients who had thrombocytopenia and high bilirubin, thrombocytopenia, high bilirubin, and no risk factor were 69.2%, 11.1%, 12.5% and 0% respectively. Hence lamivudine confers no survival benefit to conventional treatment in severe exacerbations of CHB. Patients with thrombocytopenia and high bilirubin should be considered for liver transplantation.
Interobserver variation in interpretation of serial liver biopsies from patients with chronic hepatitis C
Authors: Grønbæk K. , Christensen P. B. , Hamilton‐Dutoit S. , Federspiel B. H. , Hage E. , Jensen O. J. , Vyberg M.
Published: March 2003

summary. Reliable and accurate assessment of liver histopathology in patients with chronic hepatitis C is important for decision regarding treatment and for evaluation of therapy. However, little data on interobserver variation have been published. In this study, five specialist histopathologists evaluated 46 liver biopsies from 20 patients treated with interferon‐α. Knodell's and Ishak's scoring systems, De Groote's classification and a four level general necro‐inflammatory activity score (GNAS) were applied. Besides kappa statistics, slide by slide analysis was performed. We defined an acceptable slide by slide agreement as eight of ten observer pairs agreed on 80% of the slides. The best agreement was seen for Knodell's and Ishak's fibrosis score, De Groote's classification and GNAS (mean weighted kappa (κw) = 0.49, 0.51, 0.50 and 0.44, respectively). By condensing data from Knodell's and Ishak's scores to presence or absence of cirrhosis and piecemeal necrosis respectively, concordance was substantial concerning cirrhosis (mean κ = 0.69 and 0.72, respectively) but only moderate concerning piecemeal necrosis (mean κ = 0.40 and 0.39, respectively). Slide by slide analysis showed the highest agreement on Knodell's fibrosis score and GNAS; only one point of difference in score was to be accepted to obtain ‘eight of ten’ agreement. In contrast, five points of difference were necessary to accept in order to reach the same agreement for Knodell's total activity score. Moreover, in serial biopsies the GNAS was sufficient to detect changes in disease activity following treatment. Thus, a simple scoring system with four category scales was reproducible and sufficient for detection of therapy induced changes.
The use of nest boxes by the Red Squirrel Sciurus vulgaris in a coniferous habitat
Authors: Shuttleworth C. M.
Published: March 2003

This paper describes the results of a 4‐year study examining the use of nest boxes by Red Squirrels. Two different designs of nest box were erected in a conifer woodland which supported a high density of animals; spring population estimates were between 3.5 and 4.0 individuals per hectare. Boxes were used by adults, subadults, lactating females and their young. Breeding females more frequently used the larger of the two box designs, although this preference was not statistically significant. There was no difference in the mean sizes of litters found within the two box types. The mean size of litters present in boxes was 2.7 (n = 31, SE = 0.23) which was similar to the mean litter size of 2.5 (n = 8, SE = 0.50) found in dreys. Thus, nest boxes proved to be a valuable research tool for monitoring parturition dates, litter sizes, nestling sex ratios, and preweaning mortality.
Techniques for assessing the abundance of Brown Hares Lepus europaeus
Authors: Langbein J. , Hutchings M. R. , Harris S. , Stoate C. , Tapper S. C. , Wray S.
Published: March 2003

Over the last few decades, there have been significant declines in Brown Hare Lepus europaeus numbers throughout Europe, leading to concern for their status in many countries. In Britain, there were no quantified data on the extent of this decline, on current population levels, or any baseline against which to monitor future population changes. The need for a quantified national hare survey led to this evaluation of the techniques available to assess hare numbers. Published information on counting hares is reviewed, and various techniques compared by applying them to a number of sites in southern England.

Three basic approaches are available: counts of inactive hares, counts of active hares and indirect methods. Counts of inactive hares include total clearance, wide belt and line transect counts. Total clearance counts give an absolute figure, but are labour intensive and can only be applied to restricted areas. Wide‐belt assessments are difficult to apply in certain habitats and even in open areas tend to produce a substantial over‐estimate. Line transect counts are easy to undertake and are not labour intensive but should only be applied to large areas, or data from several small areas combined. Counts based on active hares are more problematical, because it is difficult to determine what proportion of the population is inactive at any one time. Spotlight counts based on variable circular plots are the most accurate but difficult to apply widely, and twilight counts are very subjective in their interpretation, especially when surveying small areas or areas with a large proportion of concealing habitats. Of the indirect methods, dung pellet counts can be valuable in specific areas but are difficult to apply across a range of habitats.

We concluded that, of the various techniques considered, line transect counts have the greatest potential for a national survey, but need to be stratified so that enough transects are undertaken within each habitat stratum to obtain a reliable mean population estimate for each stratum.
Glide angle in the genus Petaurus and a review of gliding in mammals
Authors: Jackson Stephen M.
Published: March 2003

The gliding angle of the Mahogany Glider Petaurus gracilis and the Sugar Glider Petaurus breviceps was determined from field studies by measuring the height of launch and landing of glides and the distance travelled. This showed no significant difference between these two species in glide ratio, which averaged 1.91 and 1.82 m distance per 1 m loss in altitude, respectively, nor in glide angle which averaged 28.26° and 29.69° for the Mahogany Glider and Sugar Glider, respectively. Significant differences were found between them for height of launch (19.75 and 11.96 m, respectively), height of landing (4.48 and 1.95 m, respectively), diameter at breast height of landing tree (44.12 and 23.22 cm, respectively), and glide distance (29.71 and 20.42 m, respectively). An examination of the ratio of interorbital width to maximum skull width of gliding and nongliding possums was measured from museum skulls to examine whether gliders have eyes wider apart, to allow triangulation of distance in preparation for gliding. Gliding possums showed a trend toward having a larger interorbital width than nongliding possums, although there appear to be several factors acting on the interorbital width. Museum study skins of all gliding marsupials were measured to determine the relationship between patagium surface area and body mass which showed a clear relationship (r2 = 0.9688). A comparison of gliding behaviour, patagium, development of limbs, tail morphology and mass was also made between gliding marsupials and other gliding mammals.
Partitions in the carnivoran auditory bulla: their formation and significance for systematics
Authors: Ivanoff D. V.
Published: March 2003

The common notion that the septa in the carnivoran auditory bulla are formed by the growth of bone edges inwards the bullar cavity is a mistaken assumption based on the data of the late 19th century. Intrabullar partitions are in fact a result of the differential resorption of the bulla internal surface during the growth of the external surface. A septum develops at the boundary between local, relatively independent, ‘inflations’ of the bulla wall.

This explanation, given by Van Kampen in 1905 for the case of the Canidae and some Mustelidae, can be applied to the whole order, including the aeluroid families with their ‘bilaminar’ septum bullae. Such an approach seems to solve the problem of homology of the intrabullar septa throughout the Carnivora, a question which has long been confused because of insufficient knowledge of septum morphogenesis. The partitions can really be considered as indicators of independent attempts to increase the size of a middle‐ear cavity among the infraorders. This conclusion follows immediately from the difference between major carnivoran taxa in the arrangement of separate inflations on the bulla wall, which can be considered as additional sinuses enlarging the hypotympanic space. It is precisely this difference that conditions the relative contribution of several bones (mainly of the ectotympanic and caudal entotympanic) to the intrabullar septa. Thus, the initial topographies of the above sinuses – whichever subsequent bone modelling of septa occurs – represent unique patterns useful in the higher‐level systematics of the Carnivora.
Mosquito carboxylesterases: a review of the molecular biology and biochemistry of a major insecticide resistance mechanism
Authors: HEMINGWAY  , KARUNARATNE
Published: March 2003

The major mechanism of organophosphorus insecticide resistance in Culex mosquitoes involves the elevation of one or more esterases. The general mechanism underlying this resistance is the amplification of the structural genes. This review covers the classification of the mosquito esterases in the context of classical esterase nomenclature. The function of the amplified esterases and the structure of the amplified DNA on which they occur are also described. Implications of information on the esterase amplicons are discussed in relation to the evolution and migration of insecticide resistance in Culex.
Factors affecting the landing and feeding responses of the tsetse fly Glossina pallidipes to a stationary ox
Authors: TORR  , HARGROVE
Published: March 2003

In Zimbabwe, studies were made of the landing and feeding responses of Glossina pallidipes on an ox. Of the tsetse approaching an ox, ≈ 70% fed. Increasing densities of tsetse increased the grooming responses of the ox but had no significant effect on the percentage of tsetse that engorged. The landing site of tsetse on the ox varied with density, with ≈ 50% landing on the legs at low densities (< 20 flies per ox), compared to ≈ 80% at densities > 40 flies per ox. For male G. pallidipes, the mean bloodmeal size was 37 mg. The probability of feeding was negatively correlated with fat content, declining from 91% for flies with < 1 mg fat to < 50% for flies with > 4 mg fat. Bloodmeal size was also negatively correlated with fat content; the regression equation relating bloodmeal size and fat content indicated that the mean wet weight declined from 42 mg for flies with 1 mg of fat to 31 mg for flies with 5 mg of fat. For females, the probability of feeding was not significantly affected by age as determined by ovarian category but there was a paucity of young (ovarian category 0) flies attracted to the ox. Pregnancy status had no significant effect on the probability of feeding, but samples of flies attracted to the ox showed a relative dearth of females approaching larviposition and a preponderance just after.
The efficacy of various pyrethroid insecticides for use on odour‐baited targets to control tsetse
Authors: Mangwiro T. N. C. , Torr S. J. , Cox J. R. , Holloway M. T. P.
Published: March 2003

The efficacy of various pyrethroid insecticides for use on odour‐baited targets to control tsetse was compared in Zimbabwe. Formulations were applied to cotton cloth and polyester net and, at various intervals, the materials were bio‐assayed by exposing fed femaleGlossina pallidipes(Austen) (Diptera: Glossinidae) to cloth for 45 s or by inducing them to collide briefly with net. Trial formulations were compared with deltamethrin suspension concentrate (s.c.), the insecticide currently used in tsetse control operations in Zimbabwe. Applying 0.8% suspension of alphacypermethrin to cloth or net produced high mortalities for 9 months which was similar in performance to 0.4% suspension of deltamethrin s.c. Deltamethrin s.c. and β‐cyfluthrin s.c. applied to cloth as 0.1% suspensions were equally effective, producing high mortalities for 2 months during the wet season, and 0.8% suspension of β‐cyfluthrin was effective for 12 months. Suspensions of 0.1% lambdacyhalothrin capsule suspension or 0.1% lambdacyhalothrin wettable powder were significantly less effective than 0.1% deltamethrin s.c. Chemical analyses showed that increasing the concentration of insecticide applied to material increased the initial amount of insecticide on the material and decreased the subsequent rate of loss; 0.1% suspension of β‐cyfluthrin s.c. applied to cloth produced an initial concentration of ≈ 280 mg/m2which declined by 94% in 12 months whereas 0.8% suspension showed no significant decrease in concentration (mean = 1304 mg/m2) over the same period. For controlling tsetse by means of pyrethroid‐treated targets, it is suggested that β‐cyfluthrin s.c. is as effective as deltamethrin s.c. but that alphacypermethrin s.c. should be used at twice the concentration of deltamethrin s.c. to obtain the same performance.
Distribution of domestic Psocoptera in Madrid apartments
Authors: Baz A. , Monserrat V. J.
Published: March 2003

Domestic Psocoptera were sampled in Madrid throughout a complete year (1991–92) by means of sticky traps in bathrooms, kitchens and inside windows. A total of 409 individuals comprising ten species of psocids was caught from 4056 traps inspected fortnightly. The predominant species were Liposcelis decolor, Li. brunnea, Psyllipsocus ramburi, Li. bostrychophila, Li. pearmani, Dorypteryx domestica and Lachesilla pedicularia, in descending order of abundance. Apartments were classified according to eight quantitative variables: age and area of building, level of apartment (i.e. storey), numbers of windows, inhabitants, their pets (birds and mammals), ornamental plants indoors; and two qualitative factors: floor material and presence or absence of trees adjacent to the house. Psocid communities in human habitations were assessed by the island biogeography theory: diversity increased with apartment size and the number of species decreased with building date. Psocid populations were most abundant in bathrooms, which presumably act as sources for dispersal to other parts of the premises. No other significant correlations were found with the other housing factors investigated. Whereas psocids were active indoors during all months of the year, the peak prevalence was in summer, July and August, one or two months ahead of the local seasonal pattern for non‐domestic psocids. Although psocids are usually not seriously unhygienic, causing only minor problems of contamination and allergies, this information should help towards their environmental control.
Protective efficacy of lambdacyhalothrin‐impregnated bednets against Phlebotomus orientalis, the vector of visceral leishmaniasis in Sudan
Authors: Elnaiem D. A. , Elnahas A. M. , Aboud M. A.
Published: March 2003

Field investigations on the sandfly Phlebotomus orientalis (Diptera: Psychodidae), the vector of Leishmania donovani causing visceral leishmaniasis (VL) in Sudan, were undertaken in two villages (Bellow and Elgamel) and Dinder National Park, to determine the protective value of bednets (polyester, 100 denier) impregnated with lambda‐cyhalothrin 10 mg a.i./m2 pyrethroid insecticide. After exposure to treated netting for 30 s, P. orientalis females all died within 1 h. When field‐tested in Acacia woodland, treated bednets provided complete protection from bites of the vector. Numbers of P. orientalis females landing on human collectors without bednets or using untreated bednets averaged 32.0 ± 8.3 or 6.9 ± 2.7 per man‐night, respectively, whereas collectors using treated bednets experienced no sandfly bites during the same period (18.00–06.00 hours, 12 nights in June 1995).

 Socio‐behavioural observations on the bed‐time of people living in both study villages indicated that the use of impregnated bednets against P. orientalis would give more potential protection for women and children than for male adults. Overall the proportions of people and their durations of exposure to the risk of sandfly bites (i.e. after sunset until they went to bed) were 40% unprotected for < 1 h, 50% for 1–2 h and > 10% for ≥ 2 h. Because visceral leishmaniasis in Sudan occurs mainly in children, the use of impregnated bednets (outdoors as well as indoors), and going to bed early could provide a high degree of personal protection against this zoonotic infection.
Density and dispersal of the loaiasis vector Chrysops dimidiata in southern Cameroon
Authors: Chippaux J. ‐P. , Bouchité B. , Demanou M. , Morlais I. , Le Goff G.
Published: March 2003

By mark–release–recapture experiments, we assessed the density of loaisis vectors, Chrysops dimidiata Wulp plus some Chrysops silacea Austen (Diptera: Tabanidae) and estimated their range of flight in the secondary forest of southern Cameroon. In 1993, the release point was at the centre of the study area and recapture points were at 1100 m radius. In 1994, releases were on the periphery of the study area and recapture sites were 400–8000 m from the release points. Results were concordant and showed Chrysops female densities of 785–3682 flies/km2. The theoretical flight range was < 6000 m, with a maximum distance of 4500 m observed. These results are considered promising for the use of vector control methods against loaiasis.
Effects of organic and inorganic fertilisers on mosquito populations in rice fields of southern India
Authors: Victor T. J. , Reuben R.
Published: March 2003

The effects of nitrogenous (inorganic) fertilisers, organic manures and blue‐green algae (BGA) biofertiliser on mosquito populations (Diptera: Culicidae) were studied in rice fields of Madurai, Tamil Nadu, south India, with particular attention to Culex vishnui Theobald, Cx. pseudovishnui Colless and Cx. tritaeniorhynchus Giles, the vectors of Japanese encephalitis (JE). The application of urea, a nitrogenous fertiliser, in rice fields significantly increased the grain yield and the population densities of mosquito larvae and pupae (anophelines as well as culicines) in a dose‐related manner. Fields treated with inorganic fertilisers (N, P, K) had significantly higher population densities of mosquito immatures than fields treated with organic manures (farmyard manure and green manure). Without nitrogenous fertiliser, BGA increased paddy yield without enhancing mosquito production. Therefore, the use of BGA with less nitrogenous fertiliser is recommended, which is beneficial economically and agronomically to the farming community and also significantly reduces mosquito production in rice fields. Increased use of nitrogenous fertiliser over the past two decades may have contributed to the increased severity of Japanese encephalitis epidemics, vectors of which breed in rice fields.
Comparisons of toxic baits for controlling the cockroach,Blattella germanica: attractiveness and feeding stimulation
Authors: Durier V. , Rivault C.
Published: March 2003

Female German cockroaches,Blattella germanica(L.) (Dictyoptera: Blattellidae) and nymphs (stages 1, 3 and 6) were used to test the attractiveness and the feeding stimulation of several commercial gel formulations of insecticide food baits in laboratory binary choice tests. The four toxic gel baits tested were: ‘Avert’ (0.05% abamectin = avermectin B1), ‘Drax’ (33.3% boric acid), ‘Goliath’ (0.05% fipronil) and ‘Maxforce’ (2.15% hydramethylnon). The attractiveness of a bait was estimated by the number of cockroaches that chose it first, and by their tendency to change to it secondarily. Feeding stimulation was estimated by the mean duration of feeding bouts and total duration of food intake. Variability of these factors was assessed in relation to age of cockroaches and to age of baits. With a few exceptions, cockroach age did not affect performance in any of these tests. Attractiveness toB. germanicaranked ‘Goliath’ gel higher than ‘Avert’, ‘Drax’ and ‘Maxforce’ gels, whether or not the active ingredient fipronil was present in ‘Goliath’ gel. Feeding stimulation ranked ‘Avert’ and ‘Maxforce’ gels higher than ‘Goliath’ gel, and ‘Drax’ gel was inferior. With ageing up to 3 months, the feeding stimulation power of ‘Goliath’ and ‘Maxforce’ gels increased, whereas that of ‘Avert’ fluctuated. Assuming that all types of bait effectively kill cockroaches once ingested, these results illustrate the importance of behavioural observations on bait efficiency and show that ranking of these different food baits varies in relation to the parameter analysed.
In situ hybridization to the Rdl locus on polytene chromosome 3L of Anopheles stephensi
Authors: Andreasen M. H. , Ffrench‐Constant R. H.
Published: March 2003

Abstract We are interested in generating a Y‐autosome translocation of the Resistance to dieldrin (Rdl ) locus in the malaria vector mosquito Anopheles stephensi Liston (Diptera: Culicidae), for use in sterile insect release. To ensure stability of the system, a recombination suppressing inversion can also be induced which encompasses the Rdl locus. As a first step, here we report the cloning of fragments of the Rdl gene from both An. stephensi and An. gambiae Giles using degenerate primers in the polymerase chain reaction. These fragments encode the second membrane‐spanning region of the γ‐aminobutyric acid receptor and show high levels of both nucleotide and predicted amino acid identity to other Rdl‐like receptors. They confirm that, as in all other arthropod species examined, dieldrin resistance in An. stephensi is associated with replacement of alanine302, in this case with a serine. In situ hybridization of the Rdl probe to polytene chromosomes of An. stephensi localizes the gene to the left arm of chromosome 3 (3L) in region 45C. Rdl localization will enable us to identify chromosomal rearrangements encompassing the Rdl locus and help anchor the genome sequence of An. gambiae to the polytene map.
In‐training assessment in postgraduate training for general practice
Authors: Hays Richard , Wellard Rod
Published: March 2003

Assessment within general practice training curricula is necessary to both guide learning and to make certification decisions about competence to practise without supervision in the community, but there is a risk that the two roles could become confused. This paper proposes a conceptual framework that explains the relationship between formative assessment, in‐training assessment and end‐point assessment, as adopted by the Royal Australian College of General Practitioners Training Programme. The literature is reviewed to suggest assessment formats that could provide a means of making decisions about progress through training without harming the important role of providing feedback to guide learners.
The United Medical and Dental School of Guy's and St Thomas' Hospitals' MSc in general practice: graduates' perspectives
Authors: Calvert Graham , Britten Nicky
Published: March 2003

Aim

Higher degrees have been proposed as one means whereby general practitioners can continue their professional development and avoid a slow decline into professional isolation and burnout. The United Medical and Dental School of Guy's and St Thomas' Hospitals' MSc in general practice has been available to experienced general practitioners for over a decade. This study reports some of the outcomes of participation for the 76 graduates of the first nine cohorts.

Method

As part of an ongoing programme of evaluation the graduates were sent a questionnaire which, in addition to seeking information about attainment of intended outcomes, gave respondents the opportunity to write freely about the contribution made by the course to their own professional and personal development. Seventy‐one graduates completed the questionnaire, a response rate of 93%.

Results and conclusions

An increased confidence that arises not only from a broadened knowledge base and increased skills but also from a sense of having been enabled to explore more deeply into their discipline, is the most frequently and highly valued outcome of participation. Graduates appreciated having additional protected time and demonstrated an ability to use it productively. A further significant outcome was the ability of the course to confront those habitual assumptions of doctors which inform their practice in a manner that was both challenging and supportive. Tendencies to professional isolation and burnout appear to have been reversed with a greater sense of connectedness to their discipline. Doctors seeking to diversify their general practice careers beyond the task of providing medical services have found the MSc an important route for change.
Conservation genetics of the endangered Pampas deer (Ozotoceros bezoarticus)
Authors: GONZÁLEZ S. , MALDONADO J. E. , LEONARD J. A. , VILÀ C. , BARBANTI DUARTE J. M. , MERINO M. , BRUM‐ZORRILLA N. , WAYNE R. K.
Published: March 2003

The Pampas deer (Ozotoceros bezoarticusL. 1758) is the most endangered neotropical cervid, and in the past occupied a wide range of open habitats including grassland, pampas, savanna, and cerrado (Brazil) from 5° to 41° S. To better understand the effect of habitat fragmentation on gene flow and genetic variation, and to uncover genetic units for conservation, we examined DNA sequences from the mitochondrial control region of 54 individuals from six localities distributed throughout the present geographical range of the Pampas deer. Our results suggest that the control region of the Pampas deer is one of the most polymorphic of any mammal. This remarkably high variability probably reflects large historic population sizes of millions of individuals in contrast to numbers of fewer than 80 000 today. Gene flow between populations is generally close to one migrant per generation and, with the exception of two populations from Argentina, all populations are significantly differentiated. The degree of gene flow was correlated with geographical distance between populations, a result consistent with limited dispersal being the primary determinant of genetic differentiation between populations. The molecular genetic results provide a mandate for habitat restoration and reintroduction of Pampas deer so that levels of genetic variation can be preserved and historic patterns of abundance can be reconstructed. However, the source of individuals for reintroduction generally should be from populations geographically closest to those now in danger of extinction.
Analysis of genetic variability of South American wild rice populations (Oryza glumaepatula) with isozymes and RAPD markers
Authors: BUSO G. S. C. , RANGEL P. H. , FERREIRA M. E.
Published: March 2003

The knowledge of population structure and genetic diversity of wild relatives of rice is needed to investigate their evolutionary history and potential use in breeding programs. Very little is known about the wild rice species (Oryza spp.), particularly those that are native to South America. A study using isozyme and RAPD markers was conducted to estimate the level of genetic diversity of four South American wild rice populations (Oryza glumaepatula) recently collected in the Amazon forest and western Brazil rivers. F‐statistics and genetic diversity parameters calculated from isozyme and RAPD markers indicated high values for inbreeding coefficients and differentiation among the four populations. In agreement with this, a pattern of greater variation between than within populations was observed with both types of markers. These findings were corroborated by an AMOVA analysis, which indicated that a large portion of the total genetic variation was attributed to regional divergence. The partition of the AMOVA analysis among populations showed that most of the genetic diversity was due to differences among populations. This distribution pattern of genetic variation of O. glumaepatula populations is in agreement with the expectation for an autogamous species and provides important baseline data for conservation and collection strategies for this species.
Amplification of DNA bound on clay minerals
Authors: ALVAREZ A. J. , KHANNA M. , TORANZOS G. A. , STOTZKY G.
Published: March 2003

DNA adsorbs and binds on clay minerals, which provides protection to the DNA against degradation by nucleases but does not eliminate the ability of bound DNA to transform cells. These observations support the concept that ‘cryptic genes’ can persist in the environment when bound on particles and that the genes could subsequently be expressed if an appropriate host was transformed. The polymerase chain reaction (PCR) was used to amplify free and bound DNA from Bacillus subtilis and calf thymus. DNA bound on montmorillonite, but not on kaolinite, was amplified. However, amplification occurred when kaolinite was pretreated with sodium metaphosphate. DNA was not released from the clays during the amplification procedure. The type of clay (e.g. its structure and charges) affected amplification. Because DNA bound on clay is protected against biodegradation, the ability to amplify DNA bound on clay by the PCR has palaeontological, archaeological, and anthropological implications for the detection of ‘ancient’ DNA, as well as for monitoring the persistence of recombinant DNA introduced to the environment in genetically modified organisms.
Clonal diversity in a Rhododendron ferrugineum L. (Ericaceae) population inferred from AFLP markers
Authors: ESCARAVAGE N. , QUESTIAU S. , PORNON A. , DOCHE B. , TABERLET P.
Published: March 2003

In the European Alps, Rhododendron ferrugineum can constitute dense populations with almost 100% of cover. The developmental pattern by layering and the resulting complexity of population structure make it difficult to identify distinct clones even by excavation. Therefore genotypic structure of a R. ferrugineum population, in the French Alps, was inferred from AFLP markers. In a first step, we analysed 400 samples using AFLP profiles generated by one selective primer pair. Seventeen bands out of 25 were polymorphic (68%). We identified a total of 32 multilocus genotypes. In a second step, the 32 genotypes were verified by applying two additional primer pairs to the two most distant samples from each genotype. The mean similarity (proportion of band sharing) between pairs of clones was 0.85 (range from 0.52 to 0.94). The spatial distribution of clones showed that vegetative spreading mainly occurred down a slope. Based on an annual shoot mean growth of 2.6 cm/year and the size of the widest clone, we estimated the age of the oldest individual to be at least 300 years. A single genotype can occupy a large surface and sometimes form a dense patch, suggesting that this species adopts a phalanx growth form with limited intermingling of some genets.