bluuebunny/crossref_metadata_2025 huggingface dataset:
The impact of six rounds of single‐dose mass administration of diethylcarbamazine or ivermectin on the transmission of Wuchereria bancrofti by Culex quinquefasciatus and its implications for lymphatic filariasis elimination programmes
Authors: Ramaiah K. D. , Das P. K. , Vanamail P. , Pani S. P.
Published: November 2003

Lymphatic filariasis (LF) is targeted for global elimination. Transmission interruption through repeated annual single‐dose mass administration of anti‐filarial drugs is the mainstay of the LF elimination strategy. This study examined the ability of six rounds of mass administration of diethylcarbamazine (DEC) or ivermectin (IVM) to interrupt transmission of Wuchereria bancrofti by Culex quinquefasciatus, the predominant parasite and vector species, respectively. After six rounds of mass drug administration (MDA), received by 54–75% of the eligible population (≥15 kg body weight), the resting vector infection and infectivity rates fell by 83% and 79% in the DEC arm, 85% and 84% in the IVM arm and 31% and 45% in the placebo arm, respectively. The landing vector infection and infectivity rates fell by 83% and 94% in the DEC arm, 63% and 75% in the IVM arm and 1% each in the placebo arm, respectively. The filarial larval load per resting mosquito declined by 92% and 93% and per landing mosquito by 83% and 69% in the DEC and IVM arms, respectively. The annual infective biting rate (AIBR) fell from 735 to 93 (87%) in the DEC arm, 422 to 102 (76%) in the IVM arm and 472 to 398 (16%) in the placebo arm. The annual transmission potential (ATP) declined from 2514 to 125 (95%), 1212 to 241 (80%) and 1547 to 1402 (9%) in the DEC, IVM and placebo arms, respectively. However, mosquitoes with infection [microfilaria/larva 1/larva 2 (Mf/L1/L2)] were found in all study villages. Three of five villages in the IVM arm and two of five in the DEC arm recorded no resting mosquitoes with infective‐stage (L3) larva. Although the ATP, after six rounds of MDA, fell substantially and remained at 125 and 241 in the DEC and IVM arms, respectively, the cumulative exposure to infective stage larvae (ATP) during the treatment period of 6 years was as high as 2995 in the DEC arm and 1522 in the IVM arm, because of considerable level of transmission during the initial (1–3) rounds of MDA. We conclude that (i) six rounds of MDA, even with 54–75% treatment coverage, can reduce LF transmission very appreciably; (ii) better treatment coverage and a few more rounds of MDA may achieve total interruption of transmission; (iii) high vector densities may partly nullify the reductions achieved in vector infection and infectivity rates by MDA and (iv) achievement of ‘true zero’ Mf prevalence in communities and 0% infection rate (mosquitoes with Mf/L1/L2) in mosquitoes may be necessary to totally interrupt Culex‐transmitted LF.
Detection and characterization of human rotavirus among children with diarrhoea in Botswana
Authors: Kasule M. , Sebunya T. K. , Gashe B. A. , Armah G. , Steele A. D.
Published: November 2003

This study reports the detection, for the first time, of human rotavirus in stools of children and the molecular characterization of isolated circulating strains in Botswana. We collected 249 stool samples between 1999 and 2001 from children with diarrhoea in three health districts of Botswana and examined them for the presence of rotavirus antigens and particles. Group A rotavirus antigen was detected in 43 of 249 (17%) of the samples tested by enzyme‐linked immunosorbent assay. Of the 43 children shedding rotaviruses, 37 (86%) were infants ≤2 years of age. The presence of rotavirus particles was also confirmed by direct electron microscopy. The characteristic 11 segments of the double‐stranded RNA mobility pattern of rotavirus were demonstrated by polyacrylamide electrophoresis in 20 of 43 (47%) of the rotavirus‐positive samples. The predominant electrophoretic pattern detected was the long (L) electrophoretype 14 of 20 (70%) followed by the short (S) electrophoretype five of 20 (25%). One strain had a mixed (L/S) pattern. Of the 26 samples subjected to subgrouping by enzyme immuno assay, eight were typed as subgroup‐II specific and seven were subgroup I. The predominant VP7 genotypes detected were G1 (59%). Two mixed strains of G1 + G3 (5%) and G1 + G2 (5%) were also detected. VP4 genotypes in circulation were: P[4] (5%), P[6] (33%) and P[8] (33%). Mixed P‐types P[4 + 6] (5%) and P[6 + 8] (18%) were also detected. Rotavirus strains G1 P[8] and GI P[6 + 8] were the most common cause of diarrhoea in our study area.
Health services analysis as a tool for evidence‐based policy decisions: the case of the Ministry of Health and Social Security in Mexico
Authors: Kroeger Axel , Hernandez Juan Manuel
Published: November 2003

Objectives  To describe the strengths and weaknesses of two Mexican health care providers for poor populations [Ministry of Health (MoH) and Social Security (SS)] in order to facilitate policy decisions about the future of the two systems.

Methodology  In four Mexican states we conducted (i) a household interview survey in 10 724 households; (ii) a user satisfaction survey in 1319 households; (iii) a satisfaction survey of 236 health workers; (iv) in‐depth interviews with 190 health workers; (v) 188 focus‐group discussions with different population groups; (vi) a document analysis.

Results  Both systems serve populations with similar characteristics of poverty. The availability of resources was better in the MoH system; SS care was better concerning process indicators (family planning, antenatal care; in‐service delivery of drugs, staff productivity, user satisfaction and staff motivation), efficiency and effectiveness (reduction of morbidity and mortality). Possible explanatory factors for the better performance of the SS system were strong supervision, regular communication, joint data analysis and annual population surveys.

Conclusion  Better service organization makes a difference regarding efficiency and effectiveness. Policy‐makers, deciding on which kind of health services are best for the poor, should take into account health services’ analyses.
Molecular assessment of drug resistance in Plasmodium falciparum from Bahr El Gazal Province, Sudan
Authors: Anderson Tim J. C. , Nair Shalini , Jacobzone Corine , Zavai Andes , Balkan Suna
Published: November 2003

Aims  To assess resistance to chloroquine (CQ) and sulphadoxine/pyrimethamine (SP) in a Sudanese parasite population.

Methods  Recurrent security problems in Akuem, Sudan, prevented us from conducting a classical in vivo treatment efficacy study. Instead we genotyped key mutations in the chloroquine resistance transporter (pfcrt), the multidrug resistance gene (pfmdr1), dihydrofolate reductase (dhfr) and dihydropteroate synthase (dhps). We genotyped the K76T mutation in pfcrt and the N86Y mutation in (pfmdr) by restriction digestion of fluorescent end‐labelled polymerase chain reaction (PCR) products, while we genotyped codons 16, 51, 59, 108 and 164 in dhfr and codons 436, 437, 540, 581 and 613 in dhps by primer extension in 100 blood samples.

Results  Sixty‐three percent of parasites carried the 76T mutation at pfcrt critical for CQ resistance, while 31% carried the 86Y mutation at pfmdr that is associated with, although not essential, for CQ resistance. We found five dhfr alleles: 60% of infections contained wild‐type dhfr alleles, 3% had one mutation, 34% had two mutations, while 3% had three mutations. We found three dhps alleles: 47% were wild type, 44% had one mutation, while 9% had two mutations.

Conclusions  We expect high levels of treatment failure (RI–RIII) with CQ (20–40%) and predict efficient treatment with SP. However, dhfr alleles with three mutations (51I, 59R, 108N) are present as are dhps alleles with two mutations (437G, 540E). Successful treatment with SP is therefore likely to be short‐lived.
Short communication: Prevalence of Entamoeba histolytica and Entamoeba dispar in northern Ghana
Authors: Verweij Jaco J. , Oostvogel Fieke , Brienen Eric A. T. , Nang‐Beifubah Alexis , Ziem Juventus , Polderman Anton M.
Published: November 2003

Since the redescription of the potentially invasive Entamoeba histolytica, separating it from the morphologically identical non‐invasive Entamoeba dispar, there is a need for the reassessment of epidemiological data on amoebiasis. In this context we conducted a descriptive survey on the presence of E. histolytica and E. dispar in a rural area in northern Ghana. We found a high prevalence (39.8%) of the E. histolytica/E. dispar complex with microscopy, but E. histolytica and E. dispar‐specific DNA amplification using real‐time polymerase chain reaction identified only one E. histolytica case and revealed a considerably higher prevalence of E. dispar (82.8%).
Psychosocial and relationship‐based theories for child and family social work: political philosophy, psychology and welfare practice
Authors: Howe David
Published: November 2003

Psychosocial perspectives on children’s development are allied to theories that recognize the ‘self’ as essentially a social entity. The quality of relationships that children experience in their social environment have a profound effect on their socio‐emotional development, personality formation and social competence. To this extent, psychosocial theories of children’s development and wellbeing can provide child and family social workers with a powerful framework within which to analyse, assess and practise. However, it is also recognized that the character of child welfare practices and policies are influenced by prevailing political climates. A simple dichotomy is described between political philosophies of the right and left; libertarianism and communitarianism; individual freedom and collective action. It is argued that the present swing to libertarian individualism has brought about major changes in the policy and practice of much child and family social work, including a preference for theories that emphasize people’s psychological independence, rationality and personal responsibility. In such a climate, child and family social work becomes more legalistic, orientated towards principles of justice rather than welfare, and towards rights and responsibilities rather than personal relationships and social competence. Psychosocial developmental theories, with their emphasis on the importance of social relationships and the emotional interconnectedness of people in community, fare less well under the rigours of psychological individualism and free‐market economics. The paper concludes that if children’s psychosocial development and competence are a product of their social history, practices that psychologically ‘disembed’ people from their relationship environment are unable to consider children’s needs within a coherent, well‐grounded theoretical framework. If child and family social work is premised on helping children develop social understanding and emotional wellbeing, theory and practice are best served by taking a psychosocial perspective.
Domestic violence and child abuse: developing social work practice
Authors: Stanley Nicky
Published: November 2003

This paper takes as its starting point the report produced by the Social Services Inspectorate (1995), entitled Domestic Violence and Social Care, which seeks to alert social workers to the links between domestic violence and child abuse and urges the profession to respond more effectively to these two interconnected forms of violence. Having examined the research findings which provide evidence for these links, the theoretical and service delivery contexts in which these two forms of violence have been studied and conceptualized by the social work profession, both in the United Kingdom and in the United States, are identified. Studies of the social work response to domestic violence are discussed and some of the difficulties experienced by social workers in responding effectively to the needs of families where both forms of violence are experienced are considered. In particular, the issues of ‘invisible’ men and ‘trapped’ women and children are explored. It is argued that effective social work intervention which challenges these stereotypes will require additional resources and the article concludes with a consideration of whether the Messages from Research report might herald a shift in the approach to child protection that would promote the allocation of resources to this area of work.
Familiar subjects? Domestic violence and child welfare
Authors: Featherstone Brid , Trinder Liz
Published: November 2003

Historically, domestic violence and child welfare have been seen as largely separate concerns. Over the last decade domestic violence has finally gained a place on social work agendas, partly as a result of linking domestic violence with child protection issues. Whilst welcoming the extent to which domestic violence is being taken seriously, we raise concerns about the dominant feminist perspectives guiding this project. We argue that current feminist theory is based on fixed and essentialist gender and generational categories which are unhelpful in understanding the complexities of family situations and family processes. Instead we argue for the relevance of relational understandings of gender, power and violence developed from feminist post‐structuralist and psychoanalytic theorists. In doing so, we challenge accepted feminist understandings of domestic violence, and question the basis upon which dominant feminist approaches claim an unviolable alliance between the interests of women and children.
Elevated leptin concentrations in growth hormone‐deficient hypopituitary adults
Authors: Al‐Shoumer Kamal A. S. , Anyaoku Victor , Richmond William , Johnston Desmond G.
Published: November 2003

BACKGROUND

Hypopituitarism with growth hormone (GH) deficiency is associated with obesity characterized by central (abdominal) distribution of fat. Recent work has demonstrated that leptin, a product of obese gene, is raised in obesity.

OBJECTIVE

To study circulating leptin levels in GH‐deficient hypopituitary adults and to investigate its anthropometric, gender and metabolic relations.

METHODS

After an overnight fast of 10–12 hours, anthropometric parameters and body composition were measured and blood was collected for the measurement of circulating leptin, glucose, intact insulin, proinsulin, IGF‐I, total cholesterol, triglycerides, high density lipoprotein (HDL) cholesterol and low density lipoprotein (LDL) cholesterol.

SUBJECTS

Fifteen (7 men) GH‐deficient hypopituitary adults (maximum stimulated serum GH to provocative testing <6 mU/l) and 21 (10 men) normal control subjects matched for age, gender and body mass index (BMI).

RESULTS

Fasting serum leptin was significantly higher in hypopituitary patients than controls (12.0 ± 1.8 vs 8.0 ± 1.5 μg/l, P = 0.04). The increase was more marked in obese (BMI > 26.0 kg/m2) patients compared with obese controls (15.3 ± 2.0 vs 8.8 ± 2.3 μg/l, P = 0.03) than in lean patients and controls. Obese control women and men had higher leptin levels than non‐obese (women, 16.6 ± 2.7 vs 8.6 ± 0.6 μg/l, P = 0.03; men, 4.9 ± 0.5 vs 2.9 ± 0.6 μg/l, P = 0.035). Similar changes were observed for obese versus non‐obese patients, although the changes did not reach statistical significance. Women in each group had significantly higher leptin concentrations than men (patients: 15.5 ± 2.3 vs 7.3 ± 1.4 μg/l, P = 0.009; controls: 12.6 ± 2.4 vs 4.3 ± 0.5 μg/l, P = 0.0001). These gender differences remained significant even when expressed in relation to BMI (patients: 0.57 ± 0.09 vs 0.26 ± 0.05 ng.m2/ml.kg, P = 0.009; controls: 0.43 ± 0.05 vs 0.16 ± 0.02 ng.m2/ml.kg, P = 0.0001). Serum leptin was positively associated with body mass index (P = 0.003), percentage body fat mass (P = 0.0001) and inversely related with age (P = 0.043). It demonstrated no relation with body weight, waist circumference, waist to hip ratio, fasting IGF‐I, glucose, insulin, proinsulin, total cholesterol, triglycerides, HDL and LDL cholesterol in patients nor controls; 86% of variance in leptin was explained by a model including body mass index, gender, age and hypopituitarism.

CONCLUSIONS

Leptin concentrations are raised in GH‐deficient hypopituitary adults to a greater extent than would be expected from the degree of obesity.
Comparison of bone and total alkaline phosphatase activity on bone turnover during menopause and in patients with established osteoporosis
Authors: Takahashi Masaaki , Kushida Kazuhiro , Hoshino Hironobu , Miura Masakazu , Ohishi Tsuyoshi , Inoue Tetsuo
Published: November 2003

OBJECTIVE

Recently, a bone alkaline phosphatase (AP) enzyme immunoassay (EIA) was developed for measurement of bone AP activity with a monoclonal antibody. We compared the clinical performance of bone AP (bAP) measured by EIA and total AP (tAP) to examine if bAP is preferable to tAP as a bone formation marker in the post‐menopause and established osteoporosis.

DESIGN AND PATIENTS

Serum was obtained from 50 pre‐ and 93 post‐menopausal healthy women, and 54 osteoporotic patients with vertebral fractures and 57 patients with hip fracture.

MEASUREMENTS

Total AP was measured spectrophotometrically with p‐nitrophenyl phosphate as substrate. The intra‐ and inter‐assay coefficients of variation were 0.7–1.8% and 0.6–1.1%, respectively. Bone AP activity (bAP) was measured by EIA kit, ALKPHASE‐BTM (Metra Biosystems, Inc.) using a monoclonal antibody against human bone AP. The intra‐ and inter‐assay CVs were 4.0–8.3% and 6.2–7.9%, respectively.

RESULTS

The percentage mean increase of bAP (54.9%) in post‐menopausal subjects over premenopausal subjects was higher than that of tAP (40.1%). In age‐matched comparison, % mean increases were 57.5% for bAP and 35.3% for tAP. Z‐score for bAP in post‐menopausal subjects was significantly higher than that for tAP. However, there was no significant difference in Z‐scores between tAP and bAP in osteoporotic patients with vertebral fractures or with hip fracture. The correlation coefficient of bAP with age (r = 0.316) was similar to that of tAP with age (r = 0.319). In post‐menopausal subjects, there was no difference in the concentrations of tAP nor bAP among the groups in whom times since the menopause was 0–9 years, 10–19 years and more than 20 years. Bone AP was highly correlated to tAP in the normal subjects, the patients and the total study group.

CONCLUSION

Preference can be given to bone AP by enzymatic immunoassay over total AP based on their clinical utility during the menopause; however, no preference can be given to bone AP over total AP in established osteoporosis.
Increased number of IGF‐I receptors on erythrocytes of women with polycystic ovarian syndrome
Authors: Gdansky E. , Diamant Y. Z. , Laron Z. , Silbergeld A. , Kaplan B. , Eshet R.
Published: November 2003

OBJECTIVE

To test the hypothesis that insulin acts though ovarian IGF‐I receptors to produce excessive amounts of androgens in polycystic ovarian syndrome (PCOS), by measuring the binding capacity of IGF‐I receptors on erythrocytes and relating the findings to the degree of hyperandrogenism and hyperinsulinaemia.

DESIGN

A case‐control study of IGF‐I receptors on erythrocytes of women with PCOS and age‐ and weight‐matched controls.

PATIENTS AND METHODS

IGF‐I receptors on erythrocytes, serum levels of androgens, IGF‐I, GH, basal insulin and insulin response during oral glucose tolerance test (oGTT) were measured after induced or spontaneous withdrawal bleeding in 10 women with PCOS and eight normo‐ovulatory women.

RESULTS

An increased number of IGF‐I receptors was found on erythrocytes of patients with PCOS compared with the controls (P  <  0.01), irrespective of their body mass index. Serum IGF‐I levels were similar in both groups. The degree of hyperinsulinaemia, provoked by oGTT, correlated positively with basal insulin (r  =  0.69; P  =  0.003), but not with the number of IGF‐I receptors. However, the number of IGF‐I receptors correlated positively with androstenedione (r  =  0.54, P  =  0.0018).

CONCLUSIONS

The findings in the present study that the number of IGF‐I receptors and not the insulin levels correlate with serum androstenedione support the theory that the hyperandrogenism in PCOS is not a direct effect of the hyperinsulinaemia, but IGF‐I mediated.
Serum leptin concentrations in a normal population and in GH deficiency: negative correlation with testosterone in men and effects of GH treatment
Authors: Nyström Fredrik , Ekman Bertil , Österlund Maria , Lindström Torbjörn , Öhman K. Peter , Arnqvist Hans J.
Published: November 2003

OBJECTIVE

To study relationships between leptin and factors regulating body composition as well as metabolic risk factors. Furthermore, to study the effects of GH on leptin.

DESIGN

Cross‐sectional and population‐based. Regarding the effects of GH, prospective and interventional.

PATIENTS

One hundred and eleven women and 107 men, 20–70 years old, randomly selected from the population registry in the community of Linköping, Sweden. Ten GH‐deficient subjects were given GH until normalization of IGF‐I levels.

MEASUREMENTS

Venous blood was drawn in the fasting state. Serum leptin and hormones were analysed by immunoassay.

RESULTS

In the population sample the natural logarithm of leptin (ln(leptin)) correlated with body mass index (BMI) (men, r  =  0.67), P  <  0.0001; women, r  =  0.71, P  <  0.0001). The median value of leptin was 4.6 μg/l in men and 12.3 μg/l in women (P  <  0.0001). Levels of ln(leptin) did not correlate with plasma neuropeptide Y (men, P  =  0.13; women, P  =  0.35). In men only there was an inverse relationship between ln(leptin) and testosterone (r  =  −0.46, P  <  0.0001, after correction for BMI standardized r  =  −0.26, P  =  0.03) as well as IGF‐I (r  =  −0.20, P  =  0.048). Although BMI was similar, smoking men had higher leptin levels than non‐smoking men (median, 6.6 and 4.2 μg/l, respectively; Mann–Whitney; P  =  0.006). In the GH‐deficient subjects leptin levels were elevated and, although GH treatment did not change BMI, leptin levels decreased (median before GH, 21 μg/l and after 15 μg/l, respectively; P  =  0.017).

CONCLUSION

Serum leptin concentration is closely associated with BMI in the population with a gender difference in absolute levels and a strong negative correlation with testosterone in men. Serum leptin is elevated in GH deficiency and lowered by GH substitution.
Insulin gene expression in adult‐onset nesidioblastosis
Authors: Fuller Peter J. , Ehrlich Allison R. , Susil Beatrice , Zeimer Howard
Published: November 2003

Nesidioblastosis is a well‐recognized cause of persistent hypoglycaemia in neonates. We describe the case of a 24‐year‐old woman who presented with hyperinsulinaemic hypoglycaemia in whom an insulinoma could not be identified at operation which resulted in her undergoing a subtotal distal pancreatectomy. Histological examination revealed the presence of nesidioblastosis. The finding of nesidioblastosis in adults has been reported previously, albeit rarely. We report the use of in situ hybridization to characterize the patterns of insulin and proglucagon gene expression in the resected pancreas. Insulin expression was observed in both the islets and also the isolated nesidioblasts. The α‐cells of the islets had lost their usual peripheral distribution suggesting that not only is insulin gene expression dysregulated but that the islets are structurally abnormal.
Postoperative metyrapone test in the early assessment of outcome of pituitary surgery for Cushing's disease
Authors: Van Aken Maarten O. , De Herder Wouter W. , Van Der Lely Aart‐Jan , De Jong Frank H. , Lamberts Steven W. J.
Published: November 2003

OBJECTIVE

The prediction of relapse during the early months after transsphenoidal surgery for Cushing's disease remains difficult. We have evaluated the usefulness of the postoperative metyrapone test in this situation.

PATIENTS

From a retrospective series of 77 consecutive primary pituitary operations for Cushing's disease 29 patients, who also had a metyrapone test at 14 days postoperatively, were selected. Median follow‐up was 35 months (range: 8–118 months).

MAIN OUTCOME MEASURES

Early postoperative: fasting morning serum cortisol, 24‐hour urinary cortisol excretion, serum 11‐deoxycortisol after 6 × 750 mg metyrapone. Remission was defined as a fasting morning serum cortisol < 140 nmol/l and/or 24‐hour urinary cortisol excretion < 250 nmol. During follow‐up: serum cortisol, as well as serum cortisol in the 1 mg overnight dexamethasone‐suppression test was measured in order to detect relapse of Cushing's disease.

RESULTS

Twelve of 29 patients were not in remission after surgery. These patients all had serum 11‐deoxycortisol levels > 350 nmol/l after metyrapone. Seventeen patients met the criteria for early remission. Four of these patients had serum 11‐deoxycortisol levels between 150 nmol/l and 350 nmol/l after metyrapone. Three of these 4 patient’s experienced a relapse of Cushing's disease during follow‐up. In the 13 patients with a serum 11‐deoxycortisol < 150 nmol/l after metyrapone, no relapse occurred.

CONCLUSIONS

The metyrapone test is a useful test in the assessment of outcome of pituitary surgery for Cushing's disease, with a sensitivity of 100% and a specificity of 75% for the early detection of patients at risk of a relapse. Patients in whom a serum 11‐deoxycortisol > 150 nmol/L is found after metyrapone are at a high risk for relapse of Cushing's disease.
Pharmacological characterization of the muscarinic receptor subtypes responsible for the contractile response in the rat urinary bladder
Authors: Tong Y.‐C. , Hung Y.‐C. , Lin S.‐N. , Cheng J.‐T.
Published: November 2003

1 Contractile responses of smooth muscle from the Wistar rat urinary bladder were studied with the use of muscarinic agonists and antagonists.

2 McN‐A‐343 induced only weak contractile responses of the bladder muscle. In contrast, oxotremorine showed higher potency than either acetylcholine or bethanechol in inducing a contractile response (the respective pD2 values were 6.38 ± 0.25, 4.82 ± 0.24 and 4.42 ± 0.14).

3 The M2 antagonists, methoctramine (10−9m to 10−5m) and gallamine (10−9m to 10−5m), did not reduce acetylcholine‐induced (10−5m) contractions of the bladder muscle strip. On the other hand, 4‐diphenyl‐acetoxy‐N‐methyl piperidine methiodide (4‐DAMP, 10−10m to 10−7m), an M3 receptor blocker, effectively antagonized the acetylcholine‐induced contractions in a concentration‐dependent manner. 4‐DAMP had a similar pA2 value to those of the non‐selective antagonists, atropine and scopolamine (pA2 values were 8.26 ± 0.05, 8.36 ± 0.05 and 8.41 ± 0.11, respectively). Pirenzepine, an M1 blocker, antagonized the contractions at higher concentrations (10−8m to 10−5m, pA2= 6.23 ± 0.04).

4 It is concluded that (1) the dominant muscarinic receptor subtype responsible for smooth muscle contraction in the rat urinary bladder is M3; and (2) the muscarinic agonist oxotremorine was more potent than acetylcholine and bethanechol in inducing a contractile response.
Spectral analysis of intercycle heart fluctuations in the diethyl‐ether‐anaesthetized or pithed rat treated with l‐hyoscyamine
Authors: Bernardi M. , Deslauriers R. , Docherty J. , Galeazzi G. , Rossini L. , Rossini P.
Published: November 2003

1 Within the context of neural regulation of the activity of sinus node pacemaker cells, the study of heart rate variability, as explored in the frequency domain by spectral analysis, was proposed about 15 years ago as a quantitative tool for the evaluation of short‐term autonomic cardiovascular control. It has since been postulated that the two main oscillations observed, one at low and the other at high frequency, may respectively be markers of sympathetic vs. vagal efferent cardiac activity, and that the low‐ and high‐frequency signals may reflect a reciprocal or ‘push–pull’ relationship between sympathetic and parasympathetic control.

2 In our power spectra assessment, ECG R–R intervals were submitted to fast Fourier transformation analysis in order to study the mechanisms underlying the control of heart beats in rats. Data were acquired in conditions of steady arterial blood pressure and cardiac and respiratory activity (spontaneous or artificially stimulated) in diethyl‐ether‐anaesthetized and pithed rats, as well as in a group of control rats, all in the presence and absence of l‐hyoscyamine.

3 With increasing doses of the parasympathetic antagonist, the fractal dimension of the time‐series structure remained stable in most cases. The low‐frequency spectral component narrowed with increasing drug doses and the high‐frequency band underwent either no, or only very slight, changes.

4 In these rodent assays, the low‐ and high‐frequency signals cannot be interpreted as a push–pull relationship between sympathetic and parasympathetic control.
Pharmacological modulation of electromechanical coupling in the proximal and distal regions of the guinea‐pig renal pelvis
Authors: Santicioli P. , Maggi C. A.
Published: November 2003

1 The effect of drugs affecting calcium and potassium channels and intracellular calcium handling/release on electromechanical coupling in the smooth muscle of the guinea‐pig proximal vs. distal renal pelvis were investigated by using the single sucrose gap method.

2 Spontaneous action potentials discharged from the proximal renal pelvis were bell‐shaped, did not show a pronounced plateau and had a small after‐hyperpolarization. Spontaneous action potentials from the distal renal pelvis were characterized by a fast depolarization, a pronounced plateau and after‐hyperpolarization.

3 Nifedipine (1 μm) suppressed action potentials in both regions of the renal pelvis. A submaximally effective concentration of nifedipine (50 nm) shortened action potential duration and reduced contractility in both regions of the renal pelvis. On the other hand Bay K 8644 (1 μm) markedly prolonged the duration of the action potential and increased contractility in both regions of the renal pelvis.

4 Tetraethylammonium (0.5 mm) markedly prolonged the action potential duration and contraction in the distal renal pelvis without affecting action potentials in the proximal renal pelvis. Similar effects were produced by a slightly higher concentration of tetraethylammonium (2 mm) in the proximal renal pelvis.

5 Charybdotoxin (30 nm) markedly prolonged the duration of action potential and increased and prolonged the contraction in both the proximal and distal renal pelvis.

6 4‐aminopyridine (1 mm) selectively increased the frequency of action potentials in the distal renal pelvis without affecting other parameters of the action potential nor contractility. 4‐aminopyridine had no effect in the proximal renal pelvis.

7 The inhibitor of sarcoplasmic reticulum Ca‐ATPase, cyclopiazonic acid (10 μm) transiently increased the frequency of action potentials in both regions of the renal pelvis; CPA markedly delayed the repolarizing phase of the action potential in both the proximal and distal renal pelvis and, in parallel, increased contractility.

8 We conclude that action potentials generated from the proximal and distal regions of the guinea‐pig renal pelvis are evenly dependent upon the availability of L‐type Ca channels; that Ca‐dependent maxi K channels provide a major contribution to the repolarization of action potentials in both regions of the renal pelvis, thus regulating duration/intensity of Ca influx and contraction; that release of Ca from the internal store is not important in providing activator Ca for contraction but regulates duration of the action potential and may be involved in setting the frequency of discharge of pacemaker cells.
Extrapolating inventory results into biodiversity estimates and the importance of stopping rules
Authors: PETERSON A. , SLADE NORMAN
Published: December 2003

Seven methods for predicting species diversity from inventory data were tested based on two model data sets. These data sets, derived from state automobile license plates observed in Mexico City and Lawrence, Kansas, had the advantage of providing known ‘communities’ to be sampled, allowing evaluation of different inference methods. Of the seven methods, those of Chao (1984), Clench (Soberón & LLorente, 1993), and model Mth of CAPTURE (Otis et al., 1978) were the most robust. Error inherent in calculations based on raw data was reduced substantially using a series of bootstrap manipulations. We recommend that optimal design of inventories should include stopping rules based on precision of results rather than on effort expended, an approach that offers considerable advantages, in terms of both accuracy of results and efficiency of sampling efforts.
Multiple hybrid origins, genetic diversity and population genetic structure of two endemic Sorbus taxa on the Isle of Arran, Scotland
Authors: Robertson A. , Newton A. C. , Ennos R. A.
Published: December 2003

Understanding the processes that have given rise to polyploid hybrid taxa is central to our understanding of plant evolution. In this study, we use an array of genetic markers in a population analysis to elucidate the hybrid origins of the Arran whitebeams Sorbus arranensis and S. pseudofennica, two woody plant taxa endemic to the Isle of Arran, Scotland. It has been proposed that S. arranensis was derived by hybridization between S. aucuparia and S. rupicola, and that subsequent hybridization between S. arranensis and S. aucuparia gave rise to S. pseudofennica. Analyses of species‐specific isozyme, nuclear intron and chloroplast DNA markers confirm the proposed origin of S. arranensis, and indicate that S. aucuparia was the female parent in the hybridization. Analysis of microsatellite markers suggests that there have been at least three origins of S. arranensis on Arran. Microsatellite markers also support the proposed hypothesis for the origin of S. pseudofennica, and indicate at least five hybrid origins of this taxon. In total, three multilocus genotypes of S. arranensis and eight of S. pseudofennica were detected on Arran and multilocus genotypic diversity levels Hg were 0.09 and 0.63, respectively. Genetic differentiation (θST) values based on multilocus genotypes are substantial (0.344 and 0.470 for S. arranensis and S. pseudofennica, respectively) implying limited seed flow among populations. These results indicate that the endemic Sorbus taxa on Arran are the products of multiple and ongoing evolutionary events. This information must be incorporated into management policies for their future conservation.
The use of reference strand‐mediated conformational analysis for the study of cheetah (Acinonyx jubatus) feline leucocyte antigen class II DRB polymorphisms
Authors: Drake G. J. C. , Kennedy L. J. , Auty H. K. , Ryvar R. , Ollier W. E. R. , Kitchener A. C. , Freeman A. R. , Radford A. D.
Published: December 2003

There is now considerable evidence to suggest the cheetah (Acinonyx jubatus) has limited genetic diversity. However, the extent of this and its significance to the fitness of the cheetah population, both in the wild and captivity, is the subject of some debate. This reflects the difficulty associated with establishing a direct link between low variability at biologically significant loci and deleterious aspects of phenotype in this, and other, species. Attempts to study one such region, the feline leucocyte antigen (FLA), are hampered by a general reliance on cloning and sequencing which is expensive, labour‐intensive, subject to PCR artefact and always likely to underestimate true variability. In this study we have applied reference strand‐mediated conformational analysis (RSCA) to determine the FLA–DRB phenotypes of 25 cheetahs. This technique was rapid, repeatable and less prone to polymerase chain reaction (PCR)‐induced sequence artefacts associated with cloning. Individual cheetahs were shown to have up to three FLA–DRB genes. A total of five alleles were identified (DRB*ha14–17 and DRB*gd01) distributed among four genotypes. Fifteen cheetahs were DRB*ha14/ha15/ha16/ha17, three were DRB*ha15/ha16/ha17, six were DRB*ha14/ha16/ha17 and one was DRB*ha14/ha15/ha16/ha17/gd01. Sequence analysis of DRB*gd01 suggested it was a recombinant of DRB*ha16 and DRB*ha17. Generation of new alleles is difficult to document, and the clear demonstration of such an event is unusual. This study confirms further the limited genetic variability of the cheetah at a biologically significant region. RSCA will facilitate large‐scale studies that will be needed to correlate genetic diversity at such loci with population fitness in the cheetah and other species.
Body size, age and paternity in common brushtail possums (Trichosurus vulpecula)
Authors: Clinchy M. , Taylor A. C. , Zanette L. Y. , Krebs C. J. , Jarman P. J.
Published: December 2003

Sexual selection should produce sexual size dimorphism in species where larger members of one sex obtain disproportionately more matings. Recent theory suggests that the degree of sexual size dimorphism depends on physical and temporal constraints involving the operational sex ratio, the potential reproductive rate and the trade‐off between current reproductive effort and residual reproductive value. As part of a large‐scale experiment on dispersal, we investigated the mating system of common brushtail possums inhabiting old‐growth Eucalyptus forest in Australia. Paternity was assigned to 20 of 28 pouch‐young (maternity known) genotyped at six microsatellite loci. Male mating success was strongly related to body size and age; male body weight and age being highly correlated. Despite disproportionate mating success favouring larger males, sexual size dimorphism was only apparent among older animals. Trapping and telemetry indicated that the operational sex ratio was effectively 1 : 1 and the potential reproductive rate of males was at most four times that of females. Being larger appeared to entail significant survival costs because males ‘died‐off’ at the age at which sexual size dimorphism became apparent (8–9 years). Male and female home ranges were the same size and males appeared to be as sedentary as females. Moreover, longevity appears to be only slightly less important to male reproductive success than it is to females. It is suggested that a sedentary lifestyle and longevity are the key elements constraining selection for greater sexual size dimorphism in this ‘model’ medium‐sized Australian marsupial herbivore.
Molecular systematics and phylogeography of the Plethodon elongatus species group: combining phylogenetic and population genetic methods to investigate species history
Authors: Mahoney Meredith J.
Published: December 2003

Plethodon elongatus and P. stormi (Caudata: Plethodontidae) are Pacific Northwest endemic species which occur in northwestern California and southwestern Oregon. Studies on these salamanders have resulted in differing taxonomic conclusions, but the underlying historical hypotheses, at both inter‐ and intraspecific levels, have never been examined in a molecular framework. Here, representatives of 81 populations from throughout the range of both taxa are sequenced. Portions of three mitochondrial protein‐coding genes (cytochrome b, NADH dehydrogenase subunit 4, and ATPase 6) were sequenced. Four haplotype groups with nonoverlapping geographical ranges were recovered in separate and combined analyses of the data. One clade corresponds to the distribution of P. stormi, while the remaining three comprise P. elongatus. Phylogenetic relationships among haplotype groups differ in separate analyses of the genes but converge on a well‐supported topology, with P. elongatus and P. stormi as monophyletic sister taxa, in combined Maximum Parsimony and Maximum Likelihood analyses. Population genetic analyses of mismatch distributions and Tajima's D‐statistic are consistent with range expansion for the largest clade within P. elongatus, covering the northern two‐thirds of the species range. In contrast, the P. stormi haplotype clade and the P. elongatus clade from the southern third of the species range may have been relatively stable. Morphological boundaries between P. elongatus and P. stormi are largely congruent with mitochondrial DNA breaks and continued treatment as sister taxa is supported. Although mitochondrial DNA haplotype groups may reflect historical separation within P. elongatus, genetic barriers are incongruent with intraspecific patterns of morphological variation.
The last common ancestor of Sarcolaenaceae and Asian dipterocarp trees was ectomycorrhizal before the India–Madagascar separation, about 88 million years ago
Authors: Ducousso M. , Béna G. , Bourgeois C. , Buyck B. , Eyssartier G. , Vincelette M. , Rabevohitra R. , Randrihasipara L. , Dreyfus B. , Prin Y.
Published: December 2003

Phylogenetic studies comparing the Dipterocarpaceae and the Sarcolaenaceae, a tree family endemic to Madagascar, have shown that the Sarcolaenaceae share a common ancestor with Asian dipterocarps. This suggests that Asian dipterocarps drifted away from Madagascar with the India–Seychelles landmass and then dispersed through Asia. Although all dipterocarps examined so far have been found to be ectomycorrhizal, the ectomycorrhizal status of Sarcolaenaceae had not been investigated. Here we establish the ectomycorrhizal status of Sarcolaenaceae using histological and molecular methods. This indicates that the common ancestor of the Sarcolaenaceae and Asian dipterocarps was ectomycorrhizal, at least before the separation of the Madagascar–India landmass, 88 million years ago.
Genetic assignment methods for the direct, real‐time estimation of migration rate: a simulation‐based exploration of accuracy and power
Authors: Paetkau David , Slade Robert , Burden Michael , Estoup Arnaud
Published: December 2003

Genetic assignment methods use genotype likelihoods to draw inference about where individuals were or were not born, potentially allowing direct, real‐time estimates of dispersal. We used simulated data sets to test the power and accuracy of Monte Carlo resampling methods in generating statistical thresholds for identifying F0 immigrants in populations with ongoing gene flow, and hence for providing direct, real‐time estimates of migration rates. The identification of accurate critical values required that resampling methods preserved the linkage disequilibrium deriving from recent generations of immigrants and reflected the sampling variance present in the data set being analysed. A novel Monte Carlo resampling method taking into account these aspects was proposed and its efficiency was evaluated. Power and error were relatively insensitive to the frequency assumed for missing alleles. Power to identify F0 immigrants was improved by using large sample size (up to about 50 individuals) and by sampling all populations from which migrants may have originated. A combination of plotting genotype likelihoods and calculating mean genotype likelihood ratios (DLR) appeared to be an effective way to predict whether F0 immigrants could be identified for a particular pair of populations using a given set of markers.
Stable Bacillus thuringiensis (Bt) toxin content in interspecific F1 and backcross populations of wild Brassica rapa after Bt gene transfer
Authors: Zhu B. , Lawrence J. R. , Warwick S. I. , Mason P. , Braun L. , Halfhill M.D. , Stewart C. N.
Published: December 2003

Stable expression of a transgene may lead to increased fitness for wild plants after acquiring the transgene via crop–weed hybridization. Here, we investigate the stability of Bt toxin content in wild Brassica rapa acquiring the Bt gene from Bt Brassica napus. The Bt toxin content in nine Bt‐expressing B. napus lines was 0.80–1.70 µg/g leaf tissue throughout the growing season. These nine lines were crossed with three accessions of wild B. rapa and the Bt gene was successfully transferred to interspecific hybrids (F1) and successive backcross generations (BC1 to BC4). The Bt toxin level in F1 and BC progenies containing the Bt gene remained at 0.90–3.10 µg/g leaf tissue. This study indicates that the Bt gene can persist and be stably expressed in wild B. rapa.
Socio‐economic factors associated with the purchasing of insecticide‐treated nets in Afghanistan and their implications for social marketing
Authors: Howard Natasha , Chandramohan Daniel , Freeman Tim , Shafi Ahmed , Rafi Mohammed , Enayatullah Sayed , Rowland Mark
Published: November 2003

Malaria is often a major health problem in war‐torn countries in the tropics owing to the collapse of health services and the vulnerability of displaced populations to epidemics. Insecticide‐treated nets (ITN) represent one of the few options for obtaining protection against malaria in unstable settings deficient in health infrastructure. Social marketing of subsidized ITN by a consortium of non‐governmental organizations began in Afghanistan in 1993 and has continued every year since then despite regular political turmoil. Almost 350 000 nets have been sold and approximately 1.2 million people protected. In 2000 we examined the determinants of ITN purchasing among households in Nangarhar province, eastern Afghanistan, as part of an effort to increase ITN uptake. The survey was conducted using a structured questionnaire to collect data on socio‐economic characteristics and malaria beliefs and practices among more than 400 net‐owning and non‐net‐owning households. A composite socio‐economic index was created using principal components analysis, and survey households were divided into socio‐economic quartiles. ITN were 4.5 times more likely to be purchased by families from the richest quartile and 2.3 times more likely to be purchased from the upper‐middle quartile than from the two lower quartiles. Even so, a significant minority from the lower quartiles did prioritize and buy ITN. In conflict affected countries where livelihoods are compromised, it is necessary to target subsidies at the most impoverished to make ITN affordable and to improve overall coverage.
Ubiquitination of TMV Coat Protein Aggregates in Infected Tobacco Leaves
Authors: Hamacher J. , Wettern M. , Schulz M.
Published: November 2003

Protein extracts from Tobacco mosaic virus (TMV) infected young tobacco leaves exhibiting strong symptoms contain higher amounts of ubiquitin conjugates in comparison with non‐infected control plants presumably due to stress reactions of host cells. Western blots with antibodies against TMV indicate as well an increase in coat protein or in ubiquitinated coat protein subunits. Immunogold labelling of infected leaf material revealed the accumulation of large amounts of coat protein in opaque inclusions which also reacted strongly with ubiquitin antibodies. These inclusions appear in close vicinity to chloroplasts in chlorotic areas of the leaf. It is concluded that most of the ubiquitin conjugates found in Western blots are due to ubiquitinated coat protein. As a consequence, a considerable amount of coat protein cannot be used for correct capsid construction as the stabilizing lysine residues are blocked by ubiquitination.
Delphacodes haywardi Muir, a New Natural Vector of Mal de Río Cuarto virus in Argentina
Authors: Velázquez P. D. , Arneodo J. D. , Guzmán F. A. , Conci L. R. , Truol G. A.
Published: November 2003

Mal de Río Cuarto virus (MRCV; Fijivirus) causes one of the principal diseases of maize in Argentina and also infects a wide range of cultivated and wild species of the Gramineae. Its spread in the Argentine maize‐growing area coincides largely with the geographical distribution of Delphacodes kuscheli, its only previously known vector. Nevertheless, the presence of MRCV in regions where D. kuscheli has not been detected, or is found only infrequently, led to the study of another delphacid species (D. haywardi) as a possible transmitter of the virus. Specimens of D. haywardi were collected from crops and pastures in the province of Entre Ríos (Argentina). MRCV was transmitted by naturally infected individuals from the field, and also in experimental transmission trials with laboratory‐reared populations of the same species. Virus in the D. haywardi samples was detected and identified with molecular hybridization probes, and in infected plants by observation of symptomatology, serological tests, electrophoresis of dsRNA and electron microscopy. The vector capacity of D. haywardi has very important implications in the epidemiology of this disease.