bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

SummarySince 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%).
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

BACKGROUNDHypopituitarism 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.OBJECTIVETo study circulating leptin levels in GH‐deficient hypopituitary adults and to investigate its anthropometric, gender and metabolic relations.METHODSAfter 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.SUBJECTSFifteen (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).RESULTSFasting 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.CONCLUSIONSLeptin 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

OBJECTIVERecently, 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 PATIENTSSerum was obtained from 50 pre‐ and 93 post‐menopausal healthy women, and 54 osteoporotic patients with vertebral fractures and 57 patients with hip fracture.MEASUREMENTSTotal 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.RESULTSThe 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.CONCLUSIONPreference 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

OBJECTIVETo 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.DESIGNA case‐control study of IGF‐I receptors on erythrocytes of women with PCOS and age‐ and weight‐matched controls.PATIENTS AND METHODSIGF‐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.RESULTSAn 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).CONCLUSIONSThe 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

OBJECTIVETo study relationships between leptin and factors regulating body composition as well as metabolic risk factors. Furthermore, to study the effects of GH on leptin.DESIGNCross‐sectional and population‐based. Regarding the effects of GH, prospective and interventional.PATIENTSOne 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.MEASUREMENTSVenous blood was drawn in the fasting state. Serum leptin and hormones were analysed by immunoassay.RESULTSIn 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).CONCLUSIONSerum 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.
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

OBJECTIVEThe 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.PATIENTSFrom 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.RESULTSTwelve 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.CONCLUSIONSThe 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.
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

AbstractUnderstanding 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

AbstractThere 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

AbstractSexual 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.