bluuebunny/crossref_metadata_2025 huggingface dataset:
Improvement of the eradication rate of Helicobacter pylori gastritis in children is by adjunction of omeprazole to a dual antibiotherapy
Authors: Cadranel S , Bontemps P , Van Biervliet S , Alliet P , Lauvau D , Vandenhoven G , Vandenplas Y
Published: April 2008

Aim: The possible improvement of efficacy and tolerability of a 7‐day dual antibiotherapy amoxicillin‐clarithromycin (AC) on the eradication of Helicobacter pylori (H. pylori) gastritis in children by the adjunction of omeprazole (OAC) was studied.

Methods: Forty‐six children presenting with H. pylori gastritis, assessed at inclusion by endoscopy, H. pylori urease test, histology and/or culture were randomised to a twice−daily regimen of AC or OAC. A 13C‐urease breath test was performed 4–6 weeks after the end of the treatment period to evaluate H. pylori eradication.

Results: A larger proportion of patients was H. pylori negative (69%) in the OAC regimen treatment 4–6 weeks after eradication treatment compared with those who received dual AC therapy (15%). A total of seven patients (three in the OAC and four in the AC group) reported adverse events (AEs). Only vomiting was reported in more than one patient (one in each treatment regimen) and only one AE was severe (urticaria: in the OAC group, but considered not related to treatment).

Conclusion: A larger eradication rate of H. pylori was obtained in the triple OAC group than in the dual AC group. Both therapy regimens can be safely administered to children for 7 days.
The effect of nutritional support on weight gain of HIV‐infected children with prolonged diarrhoea
Authors: Rollins NC , Van Den Broeck J , Kindra G , Pent M , Kasambira T , Bennish ML
Published: April 2008

Aim: To examine the effect on growth and immunity of enhanced calorie and protein provision to HIV‐infected children presenting with prolonged diarrhoea.

Methods: A total of 169 HIV‐infected children aged 6–36 months with diarrhoea for 7 days or more were randomly assigned to either standard nutrition support for children with prolonged diarrhoea or an enhanced diet started during hospitalisation and continued after discharge. The change in weight between enrolment and 8, 14 and 26 weeks and changes in plasma HIV‐RNA and CD4 cell count at 8 and 26 weeks were estimated.

Results: Children receiving enhanced nutrition achieved significantly more weight gain (p < 0.001) between enrolment and 8 weeks than children on the standard diet (median increase in weight‐for‐age standard deviation score +1.02 vs. +0.01). After 8 weeks median weight velocity was normal and similar in both groups. The change in median CD4 count was similar in both groups. The 26‐week mortality rate was high in both groups (standard support: 22%, enhanced support: 29%).

Conclusions: Nutrition support of children with advanced HIV infection and prolonged diarrhoea resulted in significant and sustained weight gain, but did not improve CD4 counts or survival. These results support integrated nutrition interventions for HIV‐infected children.
Obesity in 4‐year‐old children more prevalent in girls and in municipalities with a low socioeconomic level
Authors: Blomquist HK , Bergström E
Published: April 2008

Aim: To provide updated prevalence data of BMI and obesity in 4‐year‐old Swedish children, also exploring socioeconomic differences.

Subjects: A total of 4407 children born 1998–1999 (2231 boys and 2176 girls) in the county of Västerbotten, Sweden.

Methods: Overweight and obesity was estimated using the International Obesity Task Force cutoff values (ISO BMI). Information about socioeconomic level of the municipalities was collected from a health survey of the adult population.

Results: Of the boys, 16.7% were classified as overweight and 3.1% of these as obese. Corresponding figures for girls were 22.1% and 4.5%. The P50 and P95 values for BMI were 16.2 and 18.8 for boys and 16.1 and 19.3 for girls, respectively. P50 was at the same level as in previous Swedish studies, while P95 was higher in this study. Obesity, in girls, was more prevalent in municipalities with a low socioeconomic level.

Conclusion: Overweight and obesity in pre‐school children in Sweden is more prevalent in girls than in boys, and the prevalence is as high as in school age children. A low socioeconomic level of living area seems to be related to a higher prevalence of obesity. Increased preventive efforts, both on the individual and the societal level, must be undertaken to reduce future health risks in obese children.
Five‐years growth hormone (GH) treatment in adults with Prader‐Willi syndrome
Authors: Höybye Charlotte
Published: April 2008

Aim: We have previously shown that 1 year of growth hormone (GH) treatment to adults with Prader‐Willi syndrome (PWS) has beneficial effects on body composition. The aim of the present observational study was to re‐evaluate our cohort, with focus on long‐term GH treatment.

Methods: Seven men and seven women, median age 31 years, were available for follow‐up for 6 years. Nine were on GH treatment for 5 years. Body composition was measured with Dual Energy X‐ray absorptiometry (DXA).

Results: In six GH treated patients with genetically verified PWS there was a substantial increase in lean body mass of 5 kg (p = 0.031) and a concomitant, however, non‐significant, decrease in body fat of 5% (p = 0.156). The changes in the genetically verified patients without GH treatment were small and unsystematic. No compliance problems were reported. Only one non‐GH‐treated woman developed overt diabetes.

Conclusion: Despite inherent behavioural problems it was possible to continue GH injections for 5 years with sustained favourable effects on body composition without clinically, significant side effects.
Age is of influence on midazolam requirements in a paediatric intensive care unit
Authors: De Gast‐Bakker Dana‐Anne H , Van Der Werff Suzanne D , Sibarani‐Ponsen Renate , Swart Eleonora L , Plötz Frans B
Published: April 2008

Aim: To test that age is of influence on midazolam requirements during prolonged mechanical ventilation in critically ill children.

Methods: Retrospective observational study of children (28 days–18 year) admitted between January 1st 2002 and January 1st 2005 who needed controlled mechanical ventilation for 5 days and initial sedation with midazolam were included. Exclusion criteria were psychomotor retardation, therapeutic use of midazolam, ventilator weaning within 5 days, kidney or liver failure.

Results: A total of 1186 children were admitted, of which 58 children were included. The children were divided into three age groups: 28 days–1 year (n = 28), 1–4 years (n = 16) and older than 4 years (n = 14). Within 2 days the children age 1–4 years received the maximum midazolam dosage (0.3 mg/kg/h). In addition, the mean total dose of midazolam was higher at all days for this age group. At day 5 none of the children between 1 and 4 years could be sedated with midazolam alone.

Conclusions: Our data showed that children between 1 and 4 years needed higher doses of midazolam as compared to children who were younger and older. Furthermore, we observed that midazolam alone is a poor sedative for all age groups. The influence of and mechanisms for possible age related effects on midazolam requirements remain to be elucidated, as well as the position of midazolam as a first line drug for PICU sedation.
Early prediction of anthracycline induced cardiotoxicity
Authors: Erkus Bedirhan , Demirtas Selda , Yarpuzlu Aysegul Akbay , Can Murat , Genc Yasemin , Karaca Levent
Published: April 2008

Aim: The purpose of this study is to evaluate echocardiographically determined cardiac functions with serum levels of brain natriuretic peptide (BNP), cardiac troponin I (cTnI) and total antioxidant status (TAOS) in childhood leukemia treated with chemotherapeutics containing anthracyclines.

Methods: A study group of 29 patients who have been followed for acute lymphoblastic leukemia (ALL) and administered a treatment protocol containing chemotherapy of anthracyclines were included in the analysis. Levels of BNP, cTnI and TAOS were studied in serum samples of the patients.

Results: We demonstrated that as the drug dosage increased, systolic ejection fraction (EF) and shortening fraction (FS) values decreased (EF r2= 0.2327, FS r2= 0.251). On the other hand, increased dosage of anthracycline therapy was associated with significant raise in plasma BNP levels (r2= 0.246) and significant decrease in serum TAOS levels (r2= 0.317) without any change in serum cTnI levels.

Conclusion: Our study suggest that serum TAOS and BNP levels may be useful as an early and sensitive indicator of anthracycline induced cardiotoxicity.
Quality of infant feeding counselling for HIV+ mothers in Brazil: challenges and achievements
Authors: Rea Marina Ferreira , Santos Rosangela Gomes dos , Sanchez‐Moreno Cirlei Celia
Published: April 2008

Aim: This project aimed to assess the information and counselling on infant feeding in HIV+ mothers.

Methods: A cross‐sectional study, based on 118 structured observations of mothers' visits to health professionals (5–8/professional)—in 15 purposively selected HIV/Aids healthcare units in Sao Paulo. Results: The general quality of communication and counselling skills was good: for example, professionals responded to all mothers' questions (98%); kept eye‐to‐eye contact (82%); encouraged the mother to talk (77.1%). However, the information provided to mothers aimed to help their choices concerning infant feeding was of very poor quality. No mother, for example, was informed about alternatives to formula feeding and the danger of mixed feeding. None was offered the option of using banked breast milk. Only around 20% of mothers were informed about the safe preparation of formula feeding. When counselled by a nutritionist (compared with a paediatrician) more mothers were informed about the correct way to prepare bottle‐feeds. No mention was made of cup feeding.

Conclusion: Although health workers have good communication skills, the information provided to HIV+ mothers is insufficient. Recommending against breast‐feeding and providing infant formula may not be enough to achieve safer infant‐feeding practices.
A mitochondrial DNA polymorphism associated with cardiac arrhythmia investigated in sudden infant death syndrome
Authors: Arnestad Marianne , Opdal Siri Hauge , Vege Åshild , Rognum Torleiv Ole
Published: April 2008

Aim: Long QT syndrome (LQTS) has been shown to be the cause of death in some cases originally diagnosed as sudden infant death syndrome (SIDS). Such cardiac arrhythmias have also been noted in families with mitochondrial disease, and studies indicate that mitochondrial disease could be involved in SIDS. This makes the mtDNA polymorphism T3394C interesting, as a previous study has shown it to be associated with electrocardiographic (ECG) changes after exercise in a family with LQTS, where some members harboured a KCNH2 mutation.

Subjects: A total of 245 SIDS cases and 176 control cases.

Methods: DNA was prepared from blood/tissue samples. Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) were performed to search for the mtDNA polymorphism and KCNH2 mutation. Differences were confirmed by sequencing.

Results: The T3394C polymorphism was found in 3 pure SIDS cases (1.5%), 2 borderline SIDS cases (4.4%), 1 case of explained death (1.6%) and 2 living control cases (1.8%) (p = 0.62). The KCNH2 mutation was not found in cases or controls.

Conclusion: The mtDNA polymorphism studied was found in a small number of SIDS cases and the frequency did not differ statistically from control subjects, making an association with increased SIDS risk unlikely.
The association between non‐alcoholic fatty liver disease and insulin resistance in 20 obese children and adolescents
Authors: Ciba Iris , Widhalm Kurt
Published: April 2008

Aim: To investigate whether there are correlations between non‐alcoholic fatty liver disease (NAFLD) and insulin resistance in obese children. For the first time, we present clinical data of 20 obese children with NAFLD, including an oral glucose tolerance test.

Methods: Twenty obese children were diagnosed as having NAFLD by abdominal ultrasonography. Serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and γ‐glutamyl transferase (γ‐GT) were reported. Insulin sensitivity was evaluated by oral glucose tolerance test, oral glucose insulin sensitivity (OGIS) and homeostasis is model assessment (HOMA) index. All parameters were compared to 20 obese age‐ and sex‐matched patients without NAFLD.

Results: With 81% the prevalence of insulin resistance according to HOMA or OGIS criteria was high in the NAFLD‐patients compared to the other group with 63%. Statistically significant differences between both groups were found for mean serum ALT levels, mean glucose levels after 30, 60 and 90 minutes and mean insulin levels after 60 minutes of the glucose tolerance test.

Conclusion: The high prevalence of insulin resistance we found in children with NAFLD confirms the suggestion that there may be an association between insulin resistance and NAFLD in obese children and indicates that markers of insulin sensitivity could be useful screening parameters for NAFLD.
Topical tacrolimus is effective against eczema in Wiskott‐Aldrich syndrome (WAS)
Authors: Bienemann Klaus , Gudowius Sonja , Niehues Tim
Published: April 2008

The Wiskott‐Aldrich syndrome is a rare X‐linked immunodeficiency characterized by microplatelet thrombocytopenia and eczema. Eczema may be severe and facilitate entry of microorganism into the host.

Conclusion: We report for the first time that eczema in infants with WAS can be effectively treated with topical tacrolimus.
Reasons for inconsistent condom use by rural South African high school students
Authors: Taylor M , Dlamini SB , Nyawo N , Huver R , Jinabhai CC , De Vries H
Published: April 2008

Aim: To describe the condom use practices of high school students, compare the beliefs of students who used condoms with those who did not, investigate gender differences in condom use and identify factors that prevent condom use.

Method: Cross sectional descriptive study of sexually active grade 10 students at 28 rural high schools who completed a self‐reporting structured questionnaire.

Results: Of n = 353 students, mean age 17.50 y (SD 1.40), n = 249 (70.5%) males and n = 104 (29.5%) females (p < 0.005), n = 136 (38.5%) had used a condom at last sex. Students who used condoms differed from non‐condom users in their beliefs that use of condoms did not imply lack of trust (p = 0.03), supported girls' requesting that their partners use condoms (p = 0.002), perceived greater social support (p < 0.005), and had more self‐efficacy (p < 0.005). In the model, condom use at last sex was significantly associated with males (p = 0.03), age at first sex (p = 0.02), knowing a person infected with HIV/AIDS (p = 0.03), and condom use self‐efficacy (p = 0.001).

Conclusion: The low rate of condom use amongst these students during the AIDS epidemic is influenced by students' condom use self‐efficacy, emphasizing the need for skills' training. The increasing mortality due to HIV/AIDS may be a cue that encourages condom use.
Mitochondrial tRNA genes and flanking regions in sudden infant death syndrome
Authors: Opdal Siri Hauge , Vege Åshild , Arnestad Marianne , Musse Musse Ahmed , Rognum Torleiv Ole
Published: April 2008

Aim: Mitochondrial DNA (mtDNA) mutations have been proposed as a genetic risk factor for sudden infant death syndrome (SIDS). The aim of this study was to further investigate this issue, by sequencing the mitochondrial tRNA genes with flanking regions in SIDS cases and controls.

Method: The selected genes were investigated in 24 cases of SIDS and 10 controls, the method used were direct sequencing. In addition, the A10398G mutation in the ND3 gene was investigated in 220 SIDS cases, 26 cases of infectious death and 93 controls, using allele‐specific PCR.

Results: Mutations, recorded as differences from the revised Cambridge sequence, were found in 32 different sites in the coding regions investigated. There was no difference in mutation frequency between SIDS cases and controls, and no single mutation was found associated with SIDS.

Conclusion: The present study does not indicate an association between a specific mitochondrial tRNA gene mutation and SIDS, nor a higher mtDNA tRNA mutation frequency in SIDS cases than in controls.
The effect of the odour of mother's milk on breastfeeding behaviour of premature neonates
Authors: Raimbault Chantal , Saliba Elie , Porter Richard H.
Published: April 2008

Aim: To assess the effects of exposure to the odour of mother's milk on breastfeeding behaviour of premature neonates.

Methods: Thirteen preterm infants born at 30–33 weeks gestational age were tested. Seven infants were randomly assigned to the milk‐odour condition, 6 to the water‐control condition. During week 35 post‐conceptual age, each baby was exposed to the appropriate odour stimulus for 120 sec. on 5 consecutive days immediately prior to a breastfeeding attempt. The breastfeeding bout following the final odour exposure session, and a second breastfeeding session shortly before the baby left the hospital, were analysed. Babies were weighed before and after each feeding session.

Results: During each breastfeeding session, babies in the milk‐odour condition displayed longer sucking bouts and more bursts composed of >7 sucking movements, and also consumed more milk than the Control infants. The time spent in the hospital was significantly less for the milk‐odour condition (median = 43 days vs. 55.5 days for Controls).

Conclusion: Brief exposure to the odour of mother's milk prior to early breastfeeding trials had a positive effect on sucking behaviour and milk ingestion of preterm babies, which in turn resulted in a shortened stay in the hospital.
Parent‐dependent barriers to varicella immunization in Israel: the importance of adequate information
Authors: Adler Amos , Herring Eli , Babilsky Hanan , Gazala Eli , Cohen Avner , Levy Itzhak
Published: April 2008

Aim: To examine the parent‐dependent barriers to varicella immunization in Israel.

Methods: Data were collected by questionnaire from parents of children aged 1 to 18 years who attended an outpatient paediatric centre in five cities in Israel from March to May 2003.

Results: A total of 1474 parents completed the questionnaire. A history of chicken pox was reported in 850 children (57.8%), mostly (83%) between ages 1–6 years. Of the 624 children without a history of chicken pox, 213 (34.1%) were immunized against varicella. Immunization rates were significantly lower in families with lower parental education and in patients from cities with a lower socioeconomic ranking (p < 0.05). The main reasons for not being vaccinated (49%) were related to insufficient information about the vaccine itself and the vaccination process. These reasons were more common in families with lower parental education and from cities with lower socioeconomic ranking (p < 0.01). Other reasons included fear of adverse effects (12%) and waning immunity (6%), preference of natural illness over immunization (12%), and financial limitations (5%).

Conclusions: Promoting parental knowledge about the varicella vaccine appears to be a key factor in improving the immunization rate, especially in families of lower education, and from cities with low socioeconomic ranking.
Complete unilateral leg duplication with ipsilateral renal agenesis
Authors: Lilje Christian , Finger Leron J. , Ascuitto Robert J.
Published: April 2008

A case of a 5‐month‐old infant with complete duplication of the right leg and ipsilateral renal agenesis is presented. There was also a duplicated scrotum, posterior urethral valves with hydronephrosis, abnormal pelvic bones, and a ventricular septal defect. Complete caudal duplication is exceedingly rare. Associated defects are common. Several aetiological theories have been proposed. Among them, an underlying polytopic (acro‐renal) developmental field defect has been suggested. It best explains the specific findings in our patient. However, the aetiology of caudal duplication syndromes may be multifactorial. In the light of twinning theories, associated duplication of hindgut derivates should be suspected in similar cases. Further research is needed. The motor‐skeletal functional outcome after leg duplication surgery is mostly favourable.

Conclusion: A case of complete unilateral leg duplication with ipsilateral renal agenesis is presented. It appears to support the theory of a polytopic developmental field defect.
Temporary henna tattoo is unsafe in atopic children
Authors: Corrente Stefania , Moschese Viviana , Chianca Marco , Graziani Simona , Iannini Roberta , La Rocca Maria , Chini Loredana
Published: April 2008

Temporary henna tattoos have become increasingly popular as a safe alternative to permanent tattoos among American and European children and teenagers during the summer holidays. Currently, temporary henna tattoos contain not only henna, but also other additives such as para‐phemylenediamine (PPD), which is considered to be the chemical agent that most frequently causes skin reactions associated with the use of commercial black henna.

In this report, we describe an 11‐year‐old boy who applied a temporary black henna tattoo on his right arm during the summer holidays in Greece and developed a severe contact dermatitis at the tattoo site with residual hypopigmentation.

He had no previous history of contact dermatitis, however he did suffer from seasonal allergic rhinitis and atopic dermatitis.

Patch testing revealed a strong reaction to PPD, a substance commonly contained in temporary henna tattoo preparations.

Conclusion: Henna tattoos are an increasing problem worldwide since they carry an increased risk of severe skin reactions; therefore we suggest that the use of temporary henna tattoos in children be discouraged.
Does maternal postpartum depressive symptomatology influence infant feeding outcomes?
Authors: Dennis Cindy‐Lee , McQueen Karen
Published: April 2008

Aim: To examine the relationship between diverse infant feeding outcomes, e.g. infant feeding method, maternal satisfaction, infant feeding plans, breastfeeding progress and breastfeeding self‐efficacy) and postpartum depressive symptomatology using a time‐sequenced analysis.

Methods: As part of a population‐based study, 594 participants completed questionnaires at 1, 4 and 8 weeks postpartum.

Results: No relationship was found between diverse infant feeding outcomes at 1‐week postpartum and the development of depressive symptomatology at 4 or 8 weeks. Conversely, mothers with an Edinburgh Postnatal Depression Score >12 at 1 week postpartum were significantly more likely at 4 and/or 8 weeks to discontinue breastfeeding, be unsatisfied with their infant feeding method, experience significant breastfeeding problems and report lower levels of breastfeeding self‐efficacy.

Conclusions: The findings from this study suggest that early identification of breastfeeding mothers with depressive symptomatology is needed not only to reduce the morbidity associated with postpartum depression but also in attempt to promote increased rates of breastfeeding duration.
Saccharomyces boulardii in acute childhood diarrhoea: a randomized, placebo‐controlled study
Authors: Villarruel Gladys , Rubio Daniel Martinez , Lopez Fani , Cintioni Julio , Gurevech Rubén , Romero Gladis , Vandenplas Yvan
Published: April 2008

Objective: To evaluate the efficacy of the probiotic yeast Saccharomyces boulardii (S. boulardii) as an adjuvant to oral rehydration solution (ORS) in shortening the duration of acute infectious gastroenteritis in children less than 2 years old in ambulatory care.

Materials and methods: In a period of 1 year, 100 outpatients between 3 and 24 months old presenting with acute mild to moderate diarrhoea of less than 7 days duration, were included in a double‐blind, randomized, placebo‐controlled trial evaluating the efficacy of S. boulardii administered for 6 days. Twelve children were lost in follow‐up; the data of 88 children could be analysed (44 in the placebo and 44 in the S. boulardii group). Seventy‐two patients were followed for one month (37 in the placebo and 35 in the S. boulardii group) allowing the calculation of the duration of diarrhoea.

Results: The mean duration of diarrhoea was 6.16 days (range 2–13 days) in the placebo group and 4.70 days (range 2–10 days) in the S. boulardii group (p < 0.05). On the 4th day, the patients in the S. boulardii group passed 2.5 ± 1.4 stools/day versus 3.5 ± 1.8 in the placebo group (p < 0.001). The risk of having diarrhoea lasting more than 7 days was lower in the S. boulardii group (3/44 versus 12/44; RR 0.25; 95% CI 0.1–0.8). In no patient diarrhoea persisted longer than 14 days. A statistically significant difference was observed in the number of stools on the 4th and 7th day favouring the subgroup that received early treatment (within the first 48 h of the onset of diarrhoea). The administration of antibiotics before inclusion did not make any difference.

Conclusion: S. boulardii as an adjuvant to ORS in ambulatory care in children less than 2 years old with mild or moderate acute diarrhoea decreased the duration of diarrhoea, accelerated recovery and reduced the risk of prolonged diarrhoea. The data also indicate increased efficacy if S. boulardii is administered within the first 48 h of the onset of diarrhoea.
High plasmatic angiotensin‐converting enzyme (ACE) activity is not correlated with training‐induced left ventricular growth in ACE congenic rats
Authors: Zalvidea S. , Py G. , Lambert K. , Jover B. , Dauzat M. , Le Gallais D.
Published: April 2008

Aim:  The aim of this study was to determine the influence of angiotensin‐converting enzyme (ACE) genotype on left ventricular growth after endurance training, in ACE congenic rats with plasma ACE activity twice as high as the donor strain (LOU), thus mimicking the ACE I/D polymorphism observed in humans.

Methods:  LOU and congenic rats (n = 12) were submitted to an endurance training on a treadmill for 7 weeks, while similar LOU and congenic rats (n = 10) constituted the control groups. Blood pressure, skeletal muscle citrate synthase activity, plasma and left ventricular ACE activity were assessed, and echocardiography was performed before and after the training.

Results:  Angiotensin‐converting enzyme plasmatic activity of congenic rats (188.2 ± 26.6 in controls and 187.1 ± 22.6 IU in trained rats respectively) was twofold that of the LOU strain (91.9 ± 23.3 in controls, and 88.3 ± 18.1 IU in trained rats respectively). After training, congenic and LOU rats showed a similar significant increase in citrate synthase activity (P < 0.05), and in the left ventricular mass/body mass ratio × 103: 3.7 ± 0.3 and 3.6 ± 0.6 in the trained congenic and LOU groups, respectively, vs. 3.0 ± 0.1 and 2.9 ± 0.2 in the control congenic and LOU groups respectively (P < 0.05). There was no significant correlation between ACE plasma activity and left ventricular mass in trained or untrained congenic rats.

Conclusion:  We conclude that training‐induced left ventricular growth is not associated with plasma ACE activity in congenic rats.
Iontophoretic β‐adrenergic stimulation of human sweat glands: possible assay for cystic fibrosis transmembrane conductance regulator activityin vivo
Authors: Shamsuddin A. K. M. , Reddy M. M. , Quinton P. M.
Published: April 2008

With the advent of numerous candidate drugs for therapy in cystic fibrosis (CF), there is an urgent need for easily interpretable assays for testing their therapeutic value. Defects in the cystic fibrosis transmembrane conductance regulator (CFTR) abolished β‐adrenergic but not cholinergic sweating in CF. Therefore, the β‐adrenergic response of the sweat gland may serve both as anin vivodiagnostic tool for CF and as a quantitative assay for testing the efficacy of new drugs designed to restore CFTR function in CF. Hence, with the objective of defining optimal conditions for stimulating β‐adrenergic sweating, we have investigated the components and pharmacology of sweat secretion using cell cultures and intact sweat glands. We studied the electrical responses and ionic mechanisms involved in β‐adrenergic and cholinergic sweating. We also tested the efficacy of different β‐adrenergic agonists. Our results indicated that in normal subjects the cholinergic secretory response is mediated by activation of Ca2+‐dependent Cl−conductance as well as K+conductances. In contrast, the β‐adrenergic secretory response is mediated exclusively by activation of a cAMP‐dependent CFTR Cl−conductance without a concurrent activation of a K+conductance. Thus, the electrochemical driving forces generated by β‐adrenergic agonists are significantly smaller compared with those generated by cholinergic agonists, which in turn reflects in smaller β‐adrenergic secretory responses compared with cholinergic secretory responses. Furthermore, the β‐adrenergic agonists, isoproprenaline and salbutamol, induced sweat secretion only when applied in combination with an adenylyl cyclase activator (forskolin) or a phosphodiesterase inhibitor (3‐isobutyl‐1‐methylxanthine, aminophylline or theophylline). We surmise that to obtain consistent β‐adrenergic sweat responses, levels of intracellular cAMP above that achievable with a β‐adrenergic agonist alone are essential. β‐Adrenergic secretion can be stimulatedin vivoby concurrent iontophoresis of these drugs in normal, but not in CF, subjects.
Oestrogenic influence on brain AT1 receptor signalling on the thirst and sodium appetite in osmotically stimulated and sodium‐depleted female rats
Authors: Mecawi A. S. , Lepletier A. , Araujo I. G. , Fonseca F. V. , Reis L. C.
Published: April 2008

The present work was carried out to investigate the role of angiotensin II type 1 (AT1) receptors in nocturnal thirst and sodium appetite induced by classical models of osmotic and sodium depletion challenges in ovariectomized rats chronically treated with oil or oestradiol benzoate (EB, 20 μg per animal, s.c. daily). In both conditions, the animals were given saline or losartan (108 nmol per animal, i.c.v.), a selective AT1 receptor blocker. Oestrogen therapy significantly reduced the water intake induced by water deprivation, sodium depletion produced by frusemide injected 24 h before, and s.c. acute frusemide plus captopril injection (FUROCAP protocol), with no alteration following s.c. hypertonic saline injection. In contrast, EB therapy decreased the salt intake induced by sodium depletion and FUROCAP protocols, with no alteration following water deprivation and s.c. hypertonic saline injection. Central AT1 blockade inhibited the dipsogenic response induced by water deprivation, osmotic stimulation, chronic sodium depletion and FUROCAP protocols and inhibited the natriorexigenic response induced by sodium depletion in ovariectomized rats. Oestrogen therapy significantly attenuated the losartan‐induced antidipsogenic and antinatriorexigenic actions following sodium depletion and FUROCAP protocols. These results indicate that ovariectomized rats express increased AT1 receptor signalling related to thirst and sodium appetite responses. Oestrogen therapy and brain AT1 receptor blockade weakened or markedly decreased the behavioural responses during the nocturnal period, a time at which brain angiotensinergic activity is expected to be more prominent. Finally, we demonstrated through different experimental protocols a clear‐cut influence of oestrogenic status on the behavioural AT1‐induced signalling response.
Second coiled‐coil domain of KCNQ channel controls current expression and subfamily specific heteromultimerization by salt bridge networks
Authors: Nakajo Koichi , Kubo Yoshihiro
Published: April 2008

KCNQ channels carry the slowly activating, voltage‐dependent M‐current in excitable cells such as neurons. Although the KCNQ2 homomultimer can form a functional voltage‐gated K+ channel, heteromultimerization with KCNQ3 produces a > 10‐fold increase in current amplitude. All KCNQ channels contain double coiled‐coil domains (TCC1 and TCC2, or A‐domain Head and Tail), of which TCC2 (A‐domain Tail) is thought to be important for subunit recognition, channel assembly and surface expression. The mechanism by which TCC2 recognizes and associates with its partner is not fully understood, however. Our aim in the present study was to elucidate the recognition mechanism by examining the phenotypes of TCC2‐deletion mutants, TCC2‐swapped chimeras and point mutants. Electrophysiological analysis using Xenopus oocytes under two‐electrode voltage clamp revealed that homotetrameric KCNQ3 TCC2 is a negative regulator of current expression in the absence of KCNQ2 TCC2. Recent structural analysis of KCNQ4 TCC2 revealed the presence of intercoil salt bridge networks. We therefore swapped the sign of the charged residues reportedly involved in the salt bridge formation and functionally confirmed that the intercoil salt bridge network is responsible for the subunit recognition between KCNQ2 and KCNQ3. Finally, we constructed TCC2‐swapped KCNQ2/KCNQ3 mutants with KCNQ1 TCC2 or GCN4‐pLI, a coiled‐coil domain from an unrelated protein, and found that TCC2 is substitutable and even GCN4‐pLI can work as a substitute for TCC2. Our present data provide some new insights into the role played by TCC2 during current expression, and also provide functional evidence of the importance of the intercoil salt bridge network for subunit recognition and coiled‐coil formation, as is suggested by recent crystallographic data.
Acute effects of oestrogen on the guinea pig and humanIKrchannels and drug‐induced prolongation of cardiac repolarization
Authors: Kurokawa Junko , Tamagawa Masaji , Harada Nobuhiro , Honda Shin‐ichiro , Bai Chang‐Xi , Nakaya Haruaki , Furukawa Tetsushi
Published: April 2008

Female gender is a risk factor for drug‐induced arrhythmias associated with QT prolongation, which results mostly from blockade of thehuman ether‐a‐go‐go‐related gene(hERG) channel. Some clinical evidence suggests that oestrogen is a determinant of the gender‐differences in drug‐induced QT prolongation and baseline QTCintervals. Although the chronic effects of oestrogen have been studied, it remains unclear whether the gender differences are due entirely to transcriptional regulations through oestrogen receptors. We therefore investigated acute effects of the most bioactive oestrogen, 17β‐oestradiol (E2) at its physiological concentrations on cardiac repolarization and drug‐sensitivity of the hERG (IKr) channel in Langendorff‐perfused guinea pig hearts, patch‐clamped guinea pig cardiomyocytes and culture cells over‐expressing hERG. We found that physiological concentrations of E2 partially suppressedIKrin a receptor‐independent manner. E2‐induced modification of voltage‐dependence causes partial suppression of hERG currents. Mutagenesis studies showed that a common drug‐binding residue at the inner pore cavity was critical for the effects of E2 on the hERG channel. Furthermore, E2 enhanced both hERG suppression and QTCprolongation by its blocker, E4031. The lack of effects of testosterone at its physiological concentrations on both of hERG currents and E4031‐sensitivity of the hERG channel implicates the critical role of aromatic centroid present in E2 but not in testosterone. Our data indicate that E2 acutely affects the hERG channel gating and the E4031‐induced QTCprolongation, and may provide a novel mechanism for the higher susceptibility to drug‐induced arrhythmia in women.
Synaptic inhibition by glycine acting at a metabotropic receptor in tiger salamander retina
Authors: Hou Mingli , Duan Lei , Slaughter Malcolm M.
Published: April 2008

Glycine is the lone fast neurotransmitter for which a metabotropic pathway has not been identified. In retina, we found a strychnine‐insensitive glycine response in bipolar and ganglion cells. This glycine response reduced high voltage‐activated calcium current. It was G‐protein mediated and protein kinase A dependent. The EC50 of the metabotropic glycine response is 3 μm, an order of magnitude lower than the ionotropic glycine receptor in the same retina. The bipolar cell glutamatergic input to ganglion cells was suppressed by metabotropic glycine action. The synaptic output of about two‐thirds of bipolar cells and calcium current in two‐thirds of ganglion cells are sensitive to the action of glycine at metabotropic receptors, suggesting this signal regulates specific synaptic pathways in proximal retina. This study resolves the curious absence of a metabotropic glycine pathway in the nervous system and reveals that the major fast inhibitory neurotransmitters, GABA and glycine, both activate G‐protein‐coupled pathways as well.
Cholinergic brainstem neurons modulate cortical gamma activity during slow oscillations
Authors: Mena‐Segovia Juan , Sims Hana M. , Magill Peter J. , Bolam J. Paul
Published: April 2008

Cholinergic neurons in the rostral brainstem, including the pedunculopontine nucleus (PPN), are critical for switching behavioural state from sleep to wakefulness, and their presumed inactivity during sleep is thought to promote slow cortical rhythms that are characteristic of this state. However, it is possible that the diminished activity of cholinergic brainstem neurons during slow‐wave sleep continues to have a functional impact upon ongoing cortical activity. Here we show that identified cholinergic projection neurons in the PPN fire rhythmically during cortical slow oscillations, and predominantly discharge in time with the phase of the slow oscillations supporting nested gamma oscillations (30–60 Hz). In contrast, PPN non‐cholinergic neurons that are linked to cortical activity fire in the opposite phase and independent of nested gamma oscillations. Furthermore, cholinergic PPN neurons emit extensive local axon collaterals (as well as long‐range projections), and increasing cholinergic tone within the PPN enhances the nested gamma oscillations without producing sustained cortical activation. Thus, in addition to driving global state transitions in the cortex, cholinergic PPN neurons also play an active role in organizing cortical activity during slow‐wave sleep. Our results suggest that the role of the PPN in sleep homeostasis is more diverse than previously conceived. The functions supported by nested gamma oscillations during sleep (i.e. consolidation, plasticity) are critically dependent on the gating of the underlying cortical ensembles, and our data show that cholinergic PPN neurons have an hitherto unappreciated influence on this gating process.
Monte Carlo determination of radiation‐induced cancer risks for prostate patients undergoing intensity‐modulated radiation therapy
Authors: Stathakis Sotirios , Li Jinsheng , Ma Charlie C.M.
Published: April 2008

The application of intensity‐modulated radiation therapy (IMRT) has enabled the delivery of high doses to the target volume while sparing the surrounding normal tissues. The drawbacks of intensity modulation, as implemented using a computer‐controlled multileaf collimator (MLC), are the larger number of monitor units (MUs) and longer beam‐on time as compared with conventional radiotherapy. Additionally, IMRT uses more beam directions—typically 5 – 9 for prostate treatment—to achieve highly conformal dose and normal‐tissue sparing. In the present work, we study radiation‐induced cancer risks attributable to IMRT delivery using MLC for prostate patients.

Whole‐body computed tomography scans were used in our study to calculate (according to report no. 116 from the National Council on Radiation Protection and Measurements) the effective dose equivalent received by individual organs. We used EGS4 and MCSIM to compute the dose for IMRT and three‐dimensional conformal radiotherapy. The effects of collimator rotation, distance from the treatment field, and scatter and leakage contribution to the whole‐body dose were investigated. We calculated the whole‐body dose equivalent to estimate the increase in the risk of secondary malignancies.

Our results showed an overall doubling in the risk of secondary malignancies from the application of IMRT as compared with conventional radiotherapy. This increase in the risk of secondary malignancies is not necessarily related to a relative increase in MUs. The whole‐body dose equivalent was also affected by collimator rotation, field size, and the energy of the photon beam. Smaller field sizes of low‐energy photon beams (that is, 6 MV) with the MLC axis along the lateral axis of the patient resulted in the lowest whole‐body dose. Our results can be used to evaluate the risk of secondary malignancies for prostate IMRT patients.

PACS: 87.53.wz, 87.53.‐j
Determination of depth and field size dependence of multileaf collimator transmission in intensity‐modulated radiation therapy beams
Authors: Zygmanski Piotr , Rosca Florin , Kadam Dnyanesh , Lorenz Friedlieb , Nalichowski Adrian , Court Laurence , Chin Lee
Published: April 2008

Intensity‐modulated radiation therapy (IMRT) plans for the treatment of large and complex volumes may contain a relatively large contribution from multileaf collimator (MLC) transmission. In such cases, comprehensive characterization of direct and scatter MLC transmission is important. We designed a set of tests (open beam, closed static MLC, and dynamic MLC gap) to determine dosimetric MLC properties as a function of field size and depth at the central axis.

We developed a generalized model of MLC transmission to account for direct MLC transmission, MLC scatter, beam hardening, and leaf‐end transmission (dosimetric gap). The model is consistent with the beam model used in IMRT optimization. We tested the model for extreme asymmetric fields relevant for large targets and for split IMRT fields. We applied our MLC scatter estimation formula to clinically relevant cases and showed that MLC scatter is contributing an undesired background dose. This contribution is relatively large, especially in low‐dose regions. (For instance, a uniform extra dose may dramatically increase normal‐lung toxicity in thorax treatment.) For complex IMRT of large‐volume targets, we found direct MLC transmission dose to be as high as 30%, and MLC scatter, up to 10% within the target volume for the selected cases. We identified that the dose discrepancies between the IMRT planning system [Eclipse (Varian Medical Systems, Palo Alto, CA)] and ionization chamber measurements (inside and outside of the field) are attributable to an inadequate model of MLC transmission in the planning system (constant‐value model).

In the present study, we measured MLC transmission properties for Varian 6EX (6 MV) and 21EXs (6 and 10 MV) linear accelerators; however, the experimental method and theoretical model are more general.

PACS number: 87.53.‐j
Immunomagnetic Separation Combined with Real-Time Reverse Transcriptase PCR Assays for Detection of Norovirus in Contaminated Food
Authors: Park YoungBin , Cho You-Hee , Jee YoungMee , Ko GwangPyo
Published: April 2008

We developed an immunomagnetic separation (IMS) technique combined with real-time TaqMan reverse transcriptase PCR (RT-PCR), which allowed detection of norovirus at a level as low as 3 to 7 RT-PCR units from artificially contaminated strawberries. The inoculum recovery rate ranged from 14 to 30%. The data demonstrate that IMS combined with real-time RT-PCR will be useful as a rapid and sensitive method for detecting food-borne microbial contaminants.
Cultivation of Hard-To-Culture Subsurface Mercury-Resistant Bacteria and Discovery of New
merA
Gene Sequences
Authors: Rasmussen L. D. , Zawadsky C. , Binnerup S. J. , Øregaard G. , Sørensen S. J. , Kroer N.
Published: April 2008

Mercury-resistant bacteria may be important players in mercury biogeochemistry. To assess the potential for mercury reduction by two subsurface microbial communities, resistant subpopulations and their
merA
genes were characterized by a combined molecular and cultivation-dependent approach. The cultivation method simulated natural conditions by using polycarbonate membranes as a growth support and a nonsterile soil slurry as a culture medium. Resistant bacteria were pregrown to microcolony-forming units (mCFU) before being plated on standard medium. Compared to direct plating, culturability was increased up to 2,800 times and numbers of mCFU were similar to the total number of mercury-resistant bacteria in the soils. Denaturing gradient gel electrophoresis analysis of DNA extracted from membranes suggested stimulation of growth of hard-to-culture bacteria during the preincubation. A total of 25 different 16S rRNA gene sequences were observed, including
Alpha
-,
Beta
-, and
Gammaproteobacteria
;
Actinobacteria
;
Firmicutes
; and
Bacteroidetes
. The diversity of isolates obtained by direct plating included eight different 16S rRNA gene sequences (
Alpha
- and
Betaproteobacteria
and
Actinobacteria
). Partial sequencing of
merA
of selected isolates led to the discovery of new
merA
sequences. With phylum-specific
merA
primers, PCR products were obtained for
Alpha
- and
Betaproteobacteria
and
Actinobacteria
but not for
Bacteroidetes
and
Firmicutes
. The similarity to known sequences ranged between 89 and 95%. One of the sequences did not result in a match in the BLAST search. The results illustrate the power of integrating advanced cultivation methodology with molecular techniques for the characterization of the diversity of mercury-resistant populations and assessing the potential for mercury reduction in contaminated environments.
Retargeting R-Type Pyocins To Generate Novel Bactericidal Protein Complexes
Authors: Williams Steven R. , Gebhart Dana , Martin David W. , Scholl Dean
Published: April 2008

R-type pyocins are high-molecular-weight bacteriocins that resemble bacteriophage tail structures and are produced by some
Pseudomonas aeruginosa
strains. R-type pyocins kill by dissipating the bacterial membrane potential after binding. The high-potency, single-hit bactericidal kinetics of R-type pyocins suggest that they could be effective antimicrobials. However, the limited antibacterial spectra of natural R-type pyocins would ultimately compromise their clinical utility. The spectra of these protein complexes are determined in large part by their tail fibers. By replacing the pyocin tail fibers with tail fibers of
Pseudomonas
phage PS17, we changed the bactericidal specificity of R2 pyocin particles to a different subset of
P. aeruginosa
strains, including some resistant to PS17 phage. We further extended this idea by fusing parts of R2 tail fibers with parts of tail fibers from phages that infect other bacteria, including
Escherichia coli
and
Yersinia pestis
, changing the killing spectrum of pyocins from
P. aeruginosa
to the bacterial genus, species, or strain that serves as a host for the donor phage. The assembly of active R-type pyocins requires chaperones specific for the C-terminal portion of the tail fiber. Natural and retargeted R-type pyocins exhibit narrow bactericidal spectra and thus can be expected to cause little collateral damage to the healthy microbiotae and not to promote the horizontal spread of multidrug resistance among bacteria. Engineered R-type pyocins may offer a novel alternative to traditional antibiotics in some infections.