Study Only (study + only)

Distribution by Scientific Domains
Distribution within Medical Sciences

Kinds of Study Only

  • present study only


  • Selected Abstracts


    Effects of fungicides on thyroid function, metabolism, and thermoregulation in cotton rats,

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 8 2001
    Thomas E. Tomasi
    Abstract Among the myriad of recent studies on endocrine-disrupting chemicals, relatively few involve thyroid disruption, and most of these address exposure/disruption during embryonic life. Of those involving adult vertebrates, the endpoints examined are thyroid measurements. Even though thyroid disruption could potentially interfere with energy metabolism and thermoregulation such that over-winter survival might be compromised, the possible energetic consequences of these thyroid perturbations have not been investigated. We assessed thyroid function and measured resting metabolic rates of cotton rats chronically exposed to the fungicides vinclozolin or mancozeb. In addition, we measured norepinephrine-induced nonshivering thermogenesis and cold-induced thermogenesis and then cold-acclimated the mancozeb animals. Although thyroid hormone concentrations generally decreased, this was compensated for by an increase in thyroxine turnover (vinclozolin study only) such that thyroxine utilization rate was not different. In addition, there was no difference between the treated and control animals in any of the metabolic parameters measured. It is concluded that wild rodents exposed to these compounds are not energetically compromised. [source]


    The 15N-CPMAS spectra of simazine and its metabolites: measurements and quantum chemical calculations

    EUROPEAN JOURNAL OF SOIL SCIENCE, Issue 4 2007
    A. E. Berns
    Summary DFT calculations are a powerful tool to support NMR studies of xenobiotics such as decomposition studies in soil. They can help interpret spectra of bound residues, for example, by predicting shifts for possible model bonds. The described bound-residue models supported the hypothesis of a free amino side chain already suspected by comparison with the experimental data of the standards. No match was found between the calculated shifts of amide bondings of the amino side chains (free or substituted) and the experimental NMR shifts of a previous study. In the present paper, first-principles quantum chemical calculations were used to support and check the interpretation of the 15N cross polarization-magic angle spinning nuclear magnetic resonance (15N-CPMAS NMR) spectra of simazine and its metabolites. Density functional theory (DFT) calculations were performed using Gaussian 03 and the nuclear magnetic shielding tensors were calculated using the Gauge-Independent Atomic Orbital (GIAO) method and B3LYP/6,311+G(2d,p) model chemistry. Good agreement was reached between the calculated and measured chemical shifts of the core nitrogens and the lactam and lactim forms of the hydroxylated metabolites could be clearly distinguished. The calculated spectra showed that these metabolites exist preferentially in the lactam form, an important fact when considering the possible interactions of such hydroxylated metabolites with the soil matrix. Although the calculated bound-residue models in the present study only partly matched the experimental data, they were nevertheless useful in helping to interpret the experimental NMR results of a previous study. To get a better match between the calculated and the measured shifts of the side-chain nitrogens the calculations need to be further developed, taking into account the influence of neighbouring molecules in the solid state. Altogether, quantum chemical calculations are very helpful in the interpretation of NMR spectra. In the future, they can also be very useful for the prediction of NMR shifts, in particular when it is not possible to measure the metabolites due to a lack of material or in cases where practical experiments cannot be conducted. [source]


    Intussusception in children of school age

    PEDIATRICS INTERNATIONAL, Issue 1 2007
    TARO IKEDA
    Abstract Background: There are only a few reports discussing the characteristics of intussusception developing in school-age children. The characteristics of these cases are discussed, with reference to previous literature. Methods: The present study included eight cases of intussusception in school-age children among 143 intussusception patients treated on an inpatient basis at Nihon University Itabashi Hospital, during the 11 year period from 1993 to 2003. The remaining 135 patients were assigned to the infant group as controls. The clinical characteristics of intussusception in school-age children were compared with those of the condition developing in infants. Results: The eight children of school age with intussusception ranged in age from 8 to 15 years (mean, 11.6 years), and consisted of five boys and three girls. The major symptom was abdominal pain, occurring in 100% (8/8). Bloody stools and vomiting were reported in two patients each (25%) from this group. The triad of abdominal pain, bloody stools and vomiting was recognized in only one child (12.5%) of this group. Two children (25.0%) had a palpable abdominal mass, and one child (12.5%) complained of diarrhea. None of the school-age children with intussusception had any antecedent infection; five, two and one patients had the ileo-colic type, ileo-ileo-colic type and ileo-ileal type of intussusception, respectively. Four underwent enema reduction and four underwent surgical reduction. One of the eight children (12.5%) had underlying organic abnormality; in the remaining children the condition was labeled idiopathic. One child developed recurrences. Conclusions: In school-age children intussusception is generally believed to be commonly secondary to underlying organic abnormality, but in the present study only one of eight school-age children had underlying organic abnormality; in the remaining children, the condition was labeled idiopathic. The major symptom in school-age intussusception was abdominal pain. Therefore this may need to be differentiated from appendicitis in children of school age. It is considered that abdominal ultrasonography (USG) is a simple and useful method for making the diagnosis of intussusception, and that diagnostic USG should be conducted in all school-age children presenting with acute abdominal pain. [source]


    Intratympanic Dexamethasone for Sudden Sensorineural Hearing Loss After Failure of Systemic Therapy

    THE LARYNGOSCOPE, Issue 1 2007
    David S. Haynes MD
    Abstract Objective: Intratympanic steroids are increasingly used in the treatment of inner ear disorders, especially in patients with sudden sensorineural hearing loss (SNHL) who have failed systemic therapy. We reviewed our experience with intratympanic steroids in the treatment of patients with sudden SNHL to determine overall success, morbidity, and prognostic factors. Hypothesis: Intratympanic steroids have minimal morbidity and the potential to have a positive effect on hearing recovery in patients with sudden SNHL who have failed systemic therapy. Study Design: The authors conducted a retrospective review. Methods: Patients presenting with sudden SNHL defined as a rapid decline in hearing over 3 days or less affecting 3 or more frequencies by 30 dB or greater who underwent intratympanic steroids therapy (24 mg/mL dexamethasone) were reviewed. Excluded were patients with Meniere disease, retrocochlear disease, autoimmune HL, trauma, fluctuating HL, radiation-induced HL, noise-induced HL, or any other identifiable etiology for sudden HL. Patients who showed signs of fluctuation of hearing after injection were excluded. Pretreatment and posttreatment audiometric evaluations including pure-tone average (PTA) and speech reception threshold (SRT) were analyzed. Patient variables as they related to recovery were studied and included patient age, time to onset of therapy, status of the contralateral ear, presence of diabetes, severity of HL, and presence of associated symptoms (tinnitus, vertigo). A 20-dB gain in PTA or a 20% improvement in SDS was considered significant. Results: Forty patients fit the criteria for inclusion in the study. The mean age of the patients was 54.8 years with a range from 17 to 84 years of age. Overall, 40% (n = 16) showed any improvement in PTA or SDS. Fourteen (35%) men and 26 (65%) women were included. Using the criteria of 20-dB improvement in PTA or 20% improvement in SDS for success, 27.5% (n = 11) showed improvement. The mean number of days from onset of symptoms to intratympanic therapy was 40 days with a range of 7 days to 310 days. A statistically significant difference was noted in those patients who received earlier injection (P = .0008, rank sum test). No patient receiving intratympanic dexamethasone after 36 days recovered hearing using 20-dB PTA decrease or a 20% increase in discrimination as criteria for recovery. Twelve percent (n = 5) of patients in the study had diabetes with 20% recovering after intratympanic dexamethasone (not significantly different from nondiabetics at 28.6%, Fisher exact test, P = 1.0). Comparison to other studies that used differing steroid type, concentration, dosing schedule, inclusion criteria, and criteria for success revealed, in many instances, a similar overall recovery rate. Conclusions: Difficulty in proving efficacy of a single modality is present in all studies on SNHL secondary to multiple treatment protocols, variable rates of recovery, and a high rate of spontaneous recovery. Forty percent of patients showed some improvement in SDS or PTA after treatment failure. When criteria of 20-dB PTA or 20% is considered to define improvement, the recovery rate was 27.5%. Modest improvement is seen with the current protocol of a single intratympanic steroid injection of 24 mg/mL dexamethasone in patients who failed systemic therapy. Dramatic hearing recovery in treatment failures was rarely encountered. No patient showed significant benefit from intratympanic steroids after 36 days when using this protocol for idiopathic sudden SNHL. If patients injected after 6 weeks are excluded from the study, the improvement rate increases from 26.9% to 39.3%. Earlier intratympanic injection had a significant impact on hearing recovery, although with any therapeutic intervention for sudden SNHL, early success may be attributed to natural history. If we further exclude seven patients treated with intratympanic steroids within 2 weeks of the onset of symptoms (i.e., study only those patients treated with intratympanic dexamethasone between 2 and 6 weeks after onset of symptoms), still, 26% improved by 20 dB or 20% SDS. The recovery rates after initial systemic failure are higher than would be expected in this treatment failure group given our control group (9.1%) and literature review. These findings indicate a positive effect from steroid perfusion in this patient population. [source]


    Endemism and cryptogenesis in ,segmented' mites: A review of Australian Alicorhagiidae, Terpnacaridae, Oehserchestidae and Grandjeanicidae (Acari: Sarcoptiformes)

    AUSTRALIAN JOURNAL OF ENTOMOLOGY, Issue 3 2001
    David Evans Walter
    Abstract Endeostigmata are early derivative acariform mites, fossils of which are known from the Devonian. Extant species bear numerous plesiomorphies, the most striking being remnant opisthosomal segmentation. Also, many are all-female parthenogens with broad geographical distributions. Many of the species reported in the present study may represent clones of ancient Gondwana species. Before the present study only a handful of endeostigmatans had been reported from Australia. A key to the families of Endeostigmata is provided in the present paper, along with a review of the Australian fauna of the families Alicorhagiidae (new record), Grandjeanicidae (new record), Oehserchestidae (new record), and Terpnacaridae. Terpnacarus gibbosus (Womersley) is redescribed. A report of the first records of the cosmopolitan parthenogens Alicorhagia usitata Theron et al., Alycosmesis palmata (Oudemans), Stigmalychus veretrum Theron et al., Terpnacarus carolinaensis Theron, and Oehserchestes arboriger (Theron) in Australia is provided, along with a description of the new species Grandjeanicus theroni (Grandjeanicidae). Terpnacarus variolus Shiba and T. glebulentus Theron are junior synonyms of T. gibbosus. [source]


    Do child psychiatrists in Germany diagnose bipolar disorders in children and adolescents?

    BIPOLAR DISORDERS, Issue 5 2004
    Results from a survey
    Objectives:, There is a controversy about the prevalence of childhood bipolar disorders (BD). Based on discrepant results, we studied if German psychiatrists in outpatient settings diagnose BD in children and adolescents at all, and if there are possible correlates of the diagnoses of pediatric BD. We also asked how often typical manic symptoms (e.g. elated mood) are actually seen in attention deficit hyperactivity disorder (ADHD) patients. Methods:, Provided by the medical register we had a complete list of all 251 psychiatrists in the area. Using a questionnaire we asked if and how often they diagnose BD among children and adolescents and how often they observe manic-like symptoms in children with ADHD (response rate 61%). Results:, While 63% of all psychiatrists have diagnosed BD in adolescents, only 7.8% did so in children. Age and therapeutic approach of the psychiatrists were associated with the likelihood of having diagnosed BD in children. Furthermore some typical bipolar symptoms were also present in ADHD patients. Conclusions:, Our study only relied on self-reports of the psychiatrists about the diagnoses and number of cases, but BD in children seems to be rarely diagnosed in outpatient settings in Germany. The design of our study, however, cannot resolve the questions what the reasons are for this low rate of BD diagnoses, e.g. misdiagnoses, overlooking comorbidity or referral strategies. Epidemiological studies are needed and should consider multiple follow-ups. [source]


    Prevalence and independent risk factors for hearing loss in NICU infants

    ACTA PAEDIATRICA, Issue 8 2007
    Elysée TM Hille
    Abstract Aim: To determine the prevalence and independent relationship between hearing loss and risk factors in a representative neonatal intensive care unit (NICU) population. Methods: Automated auditory brainstem response (AABR) hearing screening has been introduced since 1998 in the Dutch NICUs. After a second AABR failure, diagnostic ABR was used to establish diagnosis of hearing loss. Newborns who died before the age of 3 months were excluded. In the present study only the NICU infants who were born with a gestational age <30 weeks and/or a birth weight <1000 g between October 1, 1998 and January 1, 2002 were included. Risk factors included in the study were familial hearing loss, in utero infections, craniofacial anomalies, birth weight <1500g, hyperbilirubinemia, ototoxic medications, cerebral complications, severe birth asphyxia, assisted ventilation ,5 days and syndromes. Results: A nationwide cohort of 2186 newborns were included. Mean gestational age was 28.5 weeks (SD 1.6) and mean birth weight was 1039 g (SD 256). Prevalence of uni- or bilateral hearing loss was 3.2% (71/2186; 95% CI 2.6,4.1). Multivariate analysis revealed that the only independent risk factors for hearing loss were severe birth asphyxia (OR 1.7; 95% CI 1.0,2.7) and assisted ventilation ,5 days (OR 3.6; 95% CI 2.1,6.0). Conclusion: The prevalence of hearing loss in a representative NICU population was 3.2%. Independent risk factors for hearing loss were severe birth asphyxia and assisted ventilation ,5 days. [source]


    The epidemiology and chronobiology of epistaxis: an investigation of Scottish hospital admissions 1995,2004

    CLINICAL OTOLARYNGOLOGY, Issue 5 2007
    T.W.M. Walker
    Objectives:, This study aimed at investigating aspects of the epidemiology and chronobiology of emergency admissions with epistaxis in Scotland between 1995 and 2004. In particular, we sought to examine the epidemiology of hospital admission with epistaxis and effects of factors such as day of week, time of year and lunar cycle. Design:, A statistical analysis, in terms of descriptive statistics, logistical regression and linear regression, was carried out on data obtained from the Scottish Morbidity Records related to emergency Ear, Nose and Throat (ENT) admissions. Setting and participants:, All emergency inpatient admissions for Scottish residents to ENT wards in Scottish NHS hospitals during the 10-year period, between 1st January 1995 and December 31st 2004 were studied. This study only looked at admissions and thus excludes Accident and Emergency attendances caused by epistaxis. Main outcome measures:, Age, gender, year, month and day of the week of admission were considered, as was relationship to the moon phase. Results:, During the study period, the mean daily admission rate with epistaxis was six. Epistaxis accounted for 33% of all ENT emergency admissions. The average age of non-epistaxis ENT emergency admission was 31 years. For epistaxis emergency admissions the median age was 70 years. There were fewer admissions in the summer months [August RR: 0.59 (95% CI: 0.54,0.65) P < 0.001]. There were more admissions at the weekends and on non-weekend public holidays [RR: ,0.115 (95% CI ,0.160,0.071) P < 0.001]. There was a trend towards a reduction in admission rates from the year 2001. Despite the fluctuations with season and weekday, there was no relationship with phase of the moon [RR: 0.98 (95% CI: 0.88,1.09) for day of the full moon compared with non-full moon weekday]. Conclusions:, This study underlines the importance of epistaxis as the single most frequent emergency diagnosis in ENT. The frequency and patterns of admission show pronounced fluctuations. The observed increase in winter admissions confirms earlier work and may have implications for health resource allocation. Relationships between weekends/public holidays and increased admissions with epistaxis may correspond with social patterns of alcohol use (a known aetiological factor). The lunar cycle does not have an effect on the frequency of epistaxis admissions. [source]