Self-regulation as a resource for coping with developmental challenges during middle childhood and adolescence: the prospective longitudinal PIERYOUTH-study

BACKGROUND

Self-regulation (SR) as the ability to regulate one's own physical state, emotions, cognitions, and behavior, is considered to play a pivotal role in the concurrent and subsequent mental and physical health of an individual. Although SR skills encompass numerous sub-facets, previous research has often focused on only one or a few of these sub-facets, and only rarely on adolescence. Therefore, little is known about the development of the sub-facets, their interplay, and their specific contributions to future developmental outcomes, particularly in adolescence. To fill these research gaps, this study aims to prospectively examine (1) the development of SR and (2) their influence on adolescent-specific developmental outcomes in a large community sample.

METHODS/DESIGN

Based on previously collected data from the Potsdam Intrapersonal Developmental Risk (PIER) study with three measurement points, the present prospective, longitudinal study aims to add a fourth measurement point (PIER_YOUTH). We aim to retain at least 1074 participants now between 16 and 23 years of the initially 1657 participants (6-11 years of age at the first measurement point in 2012/2013; 52.2% female). The study will continue to follow a multi-method (questionnaires, physiological assessments, performance-based computer tasks), multi-facet (assessing various domains of SR), and multi-rater (self-, parent-, and teacher-report) approach. In addition, a broad range of adolescent-specific developmental outcomes is considered. In doing so, we will cover the development of SR and relevant outcomes over the period of 10 years. In addition, we intend to conduct a fifth measurement point (given prolonged funding) to investigate development up to young adulthood.

DISCUSSION

With its broad and multimethodological approach, PIER_YOUTH aims to contribute to a deeper understanding of the development and role of various SR sub-facets from middle childhood to adolescence. The large sample size and low drop-out rates in the first three measurements points form a sound database for our present prospective research. Trial registration German Clinical Trials Register, registration number DRKS00030847.

The role of parental anxiety symptoms in the treatment of childhood social anxiety disorder

The study investigated the role of parental anxiety symptoms in treatment outcomes for children with a primary social anxiety disorder compared to children with other primary anxiety disorders. Participants were 152 children between 7 and 18 years and their parents (146 mothers, 123 fathers). Anxiety was assessed pretreatment, posttreatment, and at three months and one year follow ups. There were no baseline differences in parental anxiety symptoms between the two groups. In both groups parental anxiety symptoms decreased from pretreatment to posttreatment, and only mothers' anxiety symptoms decreased further from posttreatment to the one year follow up. Parental anxiety symptoms before the treatment were not related to the being free of all anxiety diagnoses in the children at posttreatment. However, some indications were found for greater improvements during treatment when parents had higher anxiety symptoms before treatment. Changes in parental anxiety symptoms were found to be related to changes in child anxiety symptoms. This was not found for the total clinical severity of all inclusion anxiety disorders. This relation was visible independently in fathers or mothers, or in groups of children with a primary social anxiety disorder or with another primary anxiety disorder. In conclusion, we did not find clear indications that parental anxiety symptoms explain the differences in treatment outcomes for children with a primary social anxiety disorder compared to children with other primary anxiety disorders. More research with larger samples is needed to draw stronger conclusions.

Variation in nectar quality across 34 grassland plant species

Floral nectar is considered the most important floral reward for attracting pollinators. It contains large amounts of carbohydrates besides variable concentrations of amino acids and thus represents an important food source for many pollinators. Its nutrient content and composition can, however, strongly vary within and between plant species. The factors driving this variation in nectar quality are still largely unclear. We investigated factors underlying interspecific variation in macronutrient composition of floral nectar in 34 different grassland plant species. Specifically, we tested for correlations between the phylogenetic relatedness and morphology of plants and the carbohydrate (C) and total amino acid (AA) composition and C:AA ratios of nectar. We found that compositions of carbohydrates and (essential) amino acids as well as C:AA ratios in nectar varied significantly within and between plant species. They showed no clear phylogenetic signal. Moreover, variation in carbohydrate composition was related to family-specific structural characteristics and combinations of morphological traits. Plants with nectar-exposing flowers, bowl- or parabolic-shaped flowers, as often found in the Apiaceae and Asteraceae, had nectar with higher proportions of hexoses, indicating a selective pressure to decelerate evaporation by increasing nectar osmolality. Our study suggests that variation in nectar nutrient composition is, among others, affected by family-specific combinations of morphological traits. However, even within species, variation in nectar quality is high. As nectar quality can strongly affect visitation patterns of pollinators and thus pollination success, this intra- and interspecific variation requires more studies to fully elucidate the underlying causes and the consequences for pollinator behaviour.

Critical links between biodiversity and health in wild bee conservation

Wild bee populations are declining due to human activities, such as land use change, which strongly affect the composition and diversity of available plants and food sources. The chemical composition of food (i.e., nutrition) in turn determines the health, resilience, and fitness of bees. For pollinators, however, the term 'health' is recent and is subject to debate, as is the interaction between nutrition and wild bee health. We define bee health as a multidimensional concept in a novel integrative framework linking bee biological traits (physiology, stoichiometry, and disease) and environmental factors (floral diversity and nutritional landscapes). Linking information on tolerated nutritional niches and health in different bee species will allow us to better predict their distribution and responses to environmental change, and thus support wild pollinator conservation.

Inherited anxiety-related parent-infant dyads alter LHPA activity

The pathogenesis of post-traumatic stress disorder (PTSD) is incompletely understood. We hypothesize that disruptions in mother-child relations may be a key contributor to development of PTSD. A normal and healthy separation-individuation process requires adaptations of self- and interactive contingency in both the mother and her child, especially in early childhood development. Anxious mothers are prone to overprotection, which may hinder the individuation process in their children. We examined long-term stress hormones and other stress markers in subjects three generations removed from the Holocaust, to assess the long-term consequences of inherited behavioral and physiological responses to prior stress and trauma. Jewish subjects who recalled overprotective parental behavior had higher hairsteroid-concentrations and dampened limbic-hypothalamic-pituitary-adrenal (LHPA) axis reactivity compared to German and Russian-German subjects with overprotective parents. We suggest that altered LHPA axis activity in maternally overprotected Jewish subjects may indicate a transmitted pathomechanism of "frustrated individuation" resulting from cross-generational anti-Semitic experiences. Thus measurements of hairsteroid-concentrations and parenting practices may have clinical value for diagnosis of PTSD. We propose that this apparent inherited adaptivity of LHPA axis activity could promote higher individual stress resistance, albeit with risk of an allostatic overload.

Interacting effects of pollination, water and nutrients on fruit tree performance

Pollination is critical to fruit production, but the interactions of pollination with plant resources on a plant's reproductive and vegetative features are largely overlooked. We examined the influences of pollination, irrigation and fertilisation on the performance of almond, Prunus dulcis, in northern California. We used a full-factorial design to test for the effects of pollination limitation on fruit production and foliage variables of whole trees experiencing four resource treatments: (i) normal water and nutrients, (ii) reduced water, (iii) no nutrients, and (iv) reduced water and no nutrients. In each of these combinations, we applied three pollination treatments: hand-cross pollination, open-pollination and pollinator exclusion. Pollination strongly affected yield even under reduced water and no nutrient applications. Hand-cross pollination resulted in over 50% fruit set with small kernels, while open-pollinated flowers showed over 30% fruit set with moderate-sized kernels. Pollinator-excluded flowers had a maximum fruit set of 5%, with big and heavy kernels. Reduced water interacted with the open- and hand-cross pollination treatments, reducing yield more than in the pollinator exclusion treatment. The number of kernels negatively influenced the number of leaves, and reduced water and no nutrient applications interacted with the pollination treatments. Overall, our results indicate that the influences of pollination on fruit tree yield interact with the plant availability of nutrients and water and that excess pollination can reduce fruit quality and the production of leaves for photosynthesis. Such information is critical to understand how pollination influences fruit tree performance.

Treatment outcome of visual feedback training in an adult patient with habitual toe walking

BACKGROUND

Habitual (idiopathic) toe walking (HTW) is not a rare diagnosis in pediatric orthopedic patients, but a relative rare pathology in adults. There are no standard recommendations for treating HTW in adult patients.

AIM

To investigate the effects of visual feedback training in an adult patient with habitual toe walking HTW.

DESIGN

case report.

SETTING

Outpatient rehabilitation department.

POPULATION

The 52--year--old woman with HTW.

METHODS

The patient participated in visual feedback training on a treadmill with integrated force plates. A display in front of the patient showed her footprints in synchrony with the treadmill speed so that the patient got dynamic feedback about the pressure of the feet on the ground in real--time on the screen. The training was conducted in 10 sessions of about 40 min within three weeks. Gait analysis (30 sec) and a measurement of the active range of joint motion of the ankle were performed before and after the 3--week treatment period and at follow--up after 3 weeks.

RESULTS

For both feet, contact time of the heel was increased after the training period, whereas contact time of the forefeet decrease. Also positive changes in the active range of joint motion of the ankle (dorsal extension) were observed in both feet. These positive effects were visible also in the follow--up assessment.

CONCLUSIONS

It was shown that providing visual feedback about foot pressure patterns is a promising treatment strategy for adult patients with HTW.

Seasonal contrasts in the response of coffee ants to agroforestry shade-tree management

In many tropical landscapes, agroforestry systems are the last forested ecosystems, providing shade, having higher humidity, mitigating potential droughts, and possessing more species than any other crop system. Here, we tested the hypothesis that higher levels of shade and associated humidity in agroforestry enhance coffee ant richness more during the dry than rainy season, comparing ant richness in 22 plots of three coffee agroforestry types in coastal Ecuador: simple-shade agroforests (intensively managed with low tree species diversity), complex-shade agroforests (extensively managed with intermediate tree species diversity) and abandoned coffee agroforests (abandoned for 10-15 yr and resembling secondary forests). Seasonality affected responses of ant richness but not composition to agroforestry management, in that most species were observed in abandoned coffee agroforests in the dry season. In the rainy season, however, most species were found in simple-shade agroforests, and complex agroforestry being intermediate. Foraging coffee ants species composition did not change differently according to agroforestry type and season. Results show that shade appears to be most important in the dry seasons, while a mosaic of different land-use types may provide adequate environmental conditions to ant species, maximizing landscape-wide richness throughout the year.

Linking deforestation scenarios to pollination services and economic returns in coffee agroforestry systems

The ecological and economic consequences of rain forest conversion and fragmentation for biodiversity, ecosystem functioning, and ecosystem services like protection of soils, water retention, pollination, or biocontrol are poorly understood. In human-dominated tropical landscapes, forest remnants may provide ecosystem services and act as a source for beneficial organisms immigrating into adjacent annual and perennial agro-ecosystems. In this study, we use empirical data on the negative effects of increasing forest distance on both pollinator diversity and fruit set of coffee to estimate future changes in pollination services for different land use scenarios in Sulawesi, Indonesia. Spatially explicit land use simulations demonstrate that depending on the magnitude and location of ongoing forest conversion, pollination services are expected to decline continuously and thus directly reduce coffee yields by up to 18%, and net revenues per hectare up to 14% within the next two decades (compared to average yields of the year 2001). Currently, forests in the study area annually provide pollination services worth 46 Euros per hectare. However, our simulations also revealed a potential win-win constellation, in which ecological and economic values can be preserved, if patches of forests (or other natural vegetation) are maintained in the agricultural landscape, which could be a viable near future option for local farmers and regional land use planners.

Therapeutic efficacy of EGb761 (Gingko biloba extract) in a transgenic mouse model of amyotrophic lateral sclerosis

EGb761 is a standardized extract of green Gingko biloba, which exerts protective effects against mitochondrial damage and oxidative stress. We examined whether oral administration of 0.022% or 0.045% EGb761 in the diet could impart neuroprotective effects in a transgenic mouse model (G93A) of amyotrophic lateral sclerosis (ALS). EGb761 significantly improved motor performance and survival, and protected against a loss of spinal-cord anterior motor horn neurons in male G93A mutant transgenic ALS mice, but not in littermate female mutant transgene mice. While EGb761 extended survival in littermate female G93A mice, significance was not reached. EGb761, however, significantly improved weight loss in both male and female transgenic ALS mice. These findings provide evidence for a gender-specific neuroprotective effect of EGb761 in a transgenic model of ALS and suggest that EGb761 may be a potential effective treatment in patients with ALS.

Transgenic ALS mice show increased vulnerability to the mitochondrial toxins MPTP and 3-nitropropionic acid

The pathogenesis of neurodegenerative diseases may involve a genetic predisposition acting in concert with environmental toxins. To test this hypothesis we examined whether transgenic mice with the G93A mutation in Cu,Zn superoxide dismutase show increased vulnerability to either 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) or 3-nitropropionic acid (3-NP). Compared to littermate controls G93A transgenic mice showed a greater loss of striatal dopamine, DOPAC, and HVA at 50, 70, and 120 days of age following administration of MPTP; however, cell loss in the substantia nigra was not greater. The G93A transgenic mice showed significantly increased vulnerability to striatal lesions produced by 3-NP compared with littermate controls at 120 days of age. The finding that G93A mice show increased vulnerability to mitochondrial toxins further implicates mitochondrial dysfunction in the pathogenesis of neuronal death in these mice. The findings support the hypothesis that a genetic defect can increase susceptibility to environmental toxins and that this may play a role in the pathogenesis of neurodegenerative diseases.

Growth-related oncogene-alpha expression in human nasal polyps

The cytokine growth-related oncogene-alpha (GRO-alpha) is a potent mediator of leukocyte recruitment and proliferation in inflammatory diseases. We hypothesized that GRO-alpha is produced in the inflammatory nasal polyp microenvironment. Evaluation of nasal polyps from 27 patients for distribution and content of GRO-alpha antigen, by use of immunohistochemical techniques and ELISA, revealed its presence in all 27 tissue samples. It was found predominantly within the eosinophils and neutrophils, with tissue levels ranging from 34 pg/mg total protein (TP) to 1746 pg/mg TP, with a mean value of 631 +/-98 pg/mg TP. Control tissues contained between 82 pg/mg TP and 316 pg/mg TP (mean 176+/-38 pg/mg TP). These results were statistically significant (P<0.03). Clinical correlations and statistical comparisons were calculated. These data suggest that GRO-alpha may be an important factor in the recruitment and activation of leukocytes in nasal polyposis, making it a potential target for therapeutic intervention.

Partial deficiency of manganese superoxide dismutase exacerbates a transgenic mouse model of amyotrophic lateral sclerosis

The pathogenesis of neuronal cell death as a consequence of mutations in copper/zinc superoxide dismutase (SOD1) associated with familial amyotrophic lateral sclerosis may involve oxidative damage and mitochondrial dysfunction. We examined whether crossing transgenic mice with the G93A SOD1 mutation with transgenic mice with a partial depletion of manganese superoxide dismutase (SOD2) would affect the disease phenotype. Compared with G93A mice alone, the mice with partial deficiency of SOD2 and the G93A SOD1 mutation showed a significant decrease in survival and an exacerbation of motor deficits detected by rotorod testing. There was a significant exacerbation of loss of motor neurons and substantia nigra dopaminergic neurons in the G93A mice with a partial deficiency of SOD2 compared with G93A mice at 110 days. Microvesiculation of large motor neurons was more prominent in the G93A mice with a partial deficiency of SOD2 compared with G93A mice at 90 days. These findings provide further evidence that both oxidative damage and mitochondrial dysfunction may play a role in the pathogenesis of motor neuron death associated with mutations in SOD1.

Neurotoxicity and oxidative damage of beta amyloid 1-42 versus beta amyloid 1-40 in the mouse cerebral cortex

Senile plaques (SP), a neuropathological hallmark of Alzheimer's disease (AD), are characterized by extracellular accumulations of beta amyloid (A beta). SP predominantly contain A beta 42 with a small amount of associated A beta 40. We determined the neurotoxic properties of A beta 42 as compared to A beta 40 by injections into the frontal cortex of three month old C57BL/6 mice. A beta 42 was associated with a significantly larger area of glial fibrillary acidic protein (GFAP) immunoreactivity and a greater density of reactive astrocytes than A beta 40. Immunohistochemical staining for markers of oxidative damage against 3-nitrotyrosine (3-NT) and 8-hydroxydeoxyguanosine (8-OHDG) were significantly more intense around the A beta 42 injection compared to the A beta 40 injection sites. These findings are consistent with previous in vitro studies and suggest that A beta 42 is more neurotoxic and may generate more free radical damage than A beta 40.

Huntington aggregates may not predict neuronal death in Huntington's disease

The mechanism by which polyglutamine expansion in Huntington's disease (HD) results in selective neuronal degeneration remains unclear. We previously reported that the immunohistochemical distribution of N-terminal huntingtin in HD does not correspond to the severity of neuropathology, such that significantly greater numbers of huntingtin aggregates are present within the cortex than in the striatum. We now show a dissociation between huntingtin aggregation and the selective pattern of striatal neuron loss observed in HD. Aggregate formation was predominantly observed in spared interneurons, with few or no aggregates found within vulnerable spiny striatal neurons. Multiple perikaryal aggregates were present in almost all cortical NADPH-diaphorase neurons and in approximately 50% of the spared NADPH-diaphorase striatal neurons from early grade HD cases. In severe grade HD patients, aggregates were more prominent as nuclear inclusions in NADPH-diaphorase neurons, with less perikaryal and neuropil aggregation. In contrast, nuclear or perikaryal huntingtin aggregates were present in less than 4% of the vulnerable calbindin striatal neurons in all HD cases. These findings support the hypothesis that polyglutamine aggregation may not be a predictor of cell loss. Rather than a harbinger of neuronal death, mutant huntingtin aggregation may be a cytoprotective mechanism against polyglutamine-induced neurotoxicity.

Creatine and cyclocreatine attenuate MPTP neurotoxicity

Systemic administration of 1-methyl-4-phenyl-1,2,3, 6-tetrahydropyridine (MPTP) produces parkinsonism in experimental animals by a mechanism involving impaired energy production. MPTP is converted by monoamine oxidase B to 1-methyl-4-phenylpyridinium (MPP+), which blocks complex I of the electron transport chain. Oral supplementation with creatine or cyclocreatine, which are substrates for creatine kinase, may increase phosphocreatine (PCr) or cyclophosphocreatine (PCCr) and buffer against ATP depletion and thereby exert neuroprotective effects. In the present study we found that oral supplementation with either creatine or cyclocreatine produced significant protection against MPTP-induced dopamine depletions in mice. Creatine protected against MPTP-induced loss of Nissl and tyrosine hydroxylase immunostained neurons in the substantia nigra. Creatine and cyclocreatine had no effects on the conversion of MPTP to MPP+ in vivo. These results further implicate metabolic dysfunction in MPTP neurotoxicity and suggest a novel therapeutic approach, which may have applicability for Parkinson's disease.

Neuroprotective effects of creatine in a transgenic animal model of amyotrophic lateral sclerosis

Mitochondria are particularly vulnerable to oxidative stress, and mitochondrial swelling and vacuolization are among the earliest pathologic features found in two strains of transgenic amyotrophic lateral sclerosis (ALS) mice with SOD1 mutations. Mice with the G93A human SOD1 mutation have altered electron transport enzymes, and expression of the mutant enzyme in vitro results in a loss of mitochondrial membrane potential and elevated cytosolic calcium concentration. Mitochondrial dysfunction may lead to ATP depletion, which may contribute to cell death. If this is true, then buffering intracellular energy levels could exert neuroprotective effects. Creatine kinase and its substrates creatine and phosphocreatine constitute an intricate cellular energy buffering and transport system connecting sites of energy production (mitochondria) with sites of energy consumption, and creatine administration stabilizes the mitochondrial creatine kinase and inhibits opening of the mitochondrial transition pore. We found that oral administration of creatine produced a dose-dependent improvement in motor performance and extended survival in G93A transgenic mice, and it protected mice from loss of both motor neurons and substantia nigra neurons at 120 days of age. Creatine administration protected G93A transgenic mice from increases in biochemical indices of oxidative damage. Therefore, creatine administration may be a new therapeutic strategy for ALS.

Enterocutaneous fistula as a postoperative complication of laparoscopic inguinal hernia repair

Trocar injuries to the small bowel during laparoscopic hernia repair are a rare complication, the most common complications being postoperative neuralgias, scrotal swelling, scrotal ecchymosis, and hematoma. A 15-year-old boy was admitted 5 days status-post transabdominal laparoscopic inguinal hernia repair of a symptomatic right pantaloon hernia, with signs and symptoms of a retrocecal abscess. Despite laparotic intervention and appendectomy, the next 2 years passed with almost daily, purulent, right lower quadrant wound drainage, in an otherwise asymptomatic patient. Superficial wound exploration and sinogram in 1996 revealed a sinus tract in direct communication with the small bowel. Elective laparotomy in December 1997 involved a successful resection of a 2.5-cm fistula with involved mesh, and the communicating small bowel through a midline incision, followed by a primary closure of the small-bowel opening. The patient has recovered without complications.

The natural history of nephrocalcinosis in premature infants treated with loop diuretics

PURPOSE

We investigated the natural history of nephrocalcinosis in premature infants treated with furosemide and attempted to identify factors to predict infants most at risk.

MATERIALS AND METHODS

We evaluated 13 preterm infants in this longitudinal pilot study. During hospitalization and while receiving a loop diuretic nephrocalcinosis developed in each patient. Patients were divided into groups based on resolution (6) and nonresolution (7) according to spontaneous resolution of nephrocalcinosis at any point during followup. The 2 groups were compared to each other and to a control group.

RESULTS

Mean followup after discontinuation of furosemide in the resolution versus nonresolution groups was 10.3 and 7.7 months, respectively. Between the 2 groups there was no significant difference in average gestational age, birth weight, number of days hospitalized or on furosemide, or total furosemide dose. Mean calcium-to-creatinine ratio while receiving furosemide at the time nephrocalcinosis developed was 0.38 in the resolution group but 2.23 in the nonresolution group (p < 0.005). Initial calcium-to-creatinine ratio in age matched infants who did not have nephrocalcinosis was 0.4. Frank renal stones developed in 2 of the 7 patients without resolution and 0 of the 6 with resolution. When nephrocalcinosis resolved, it was at a mean of 5.2 months following discontinuation of the diuretic.

CONCLUSIONS

Early data indicate that nephrocalcinosis resolves in approximately 50% of premature infants 5 to 6 months after discontinuation of furosemide. The only factor that appears to be predictive of the infants who will have resolution is the calcium-to-creatinine ratio when nephrocalcinosis is diagnosed. In patients without resolution this ratio is much higher than in age adjusted normal controls, while in those with resolution it appears normal for age.

Intestinal perforations in infants with a very low birth weight: a disease of increasing survival?

Seventeen infants with a very low birth weight (VLBW) and spontaneous, non-necrotizing enterocolitis (NEC), intestinal perforations are presented; 14 of them were seen in the past 3 years. A comparison with 16 surgically treated NEC infants (< 1,000 g) is provided. At our institution, the yearly survival of VLBW infants increased from 54% to 90% over the past 6 years. All 17 non-NEC patients were operated on, and 15 (88.2%) survived. Ileal perforations were observed frequently. Initial enterostomies were followed by reanastomosis at an average age of 3 months. A 22.6-month follow-up was attained for all survivors. Non-NEC intestinal perforations in tiny neonates are increasing and constitute a challenging but treatable group. The improving survival rate of VLBW infants will probably be accompanied by a variety of complications.

Sensorineural hearing loss associated with Kawasaki disease

In five children who met the diagnostic criteria for Kawasaki Disease, sensorineural hearing loss developed in association with the acute illness. The children, aged 7 months to 13 years, had deficits ranging from mild to profound bilateral sensorineural hearing loss. There were no associated neurologic abnormalities, and immunologic investigations and magnetic resonance imaging failed to reveal a cause. Treatment regimens differed among the children, but none had high salicylate levels (greater than 20 mg/dl) or received other ototoxic medications. Antiinflammatory therapy was not obviously beneficial in any case, and four of the children have persistent hearing deficits. We conclude that auditory involvement may be a complication of Kawasaki disease; screening of clinically affected children should be considered.

Rectal pH in children

In an attempt to establish normal values for rectal pH in children, we have measured pH in 100 paediatric patients. Measurement of rectal pH was performed in 25 infants and 75 children (27 girls and 73 boys) using a monocrystalline antimony electrode. Rectal pH was 9.6 +/- 0.9 (mean +/- SD, range 7.2 to 12.1) and was independent of sex, age and nutrition. This wide range of rectal pH values offers a possible explanation for the widely scattered bioavailability of drugs administered by the rectal route. Mean rectal pH was considerably higher than that reported for adults; this unexpected alkalinity should be taken into account, when drug formulations are considered for rectal administration in children.

Prolonged anaesthesia with isoflurane and halothane. Effects on hepatic function

Hepatic function was assessed pre-operatively and on the first and sixth postoperative days in 40 healthy patients who underwent prolonged maxillofacial surgery with isoflurane or halothane anaesthesia. No major changes were observed in hepatic enzymes or bilirubin. One-stage prothrombin time and Factor VII concentrations decreased on the first postoperative day and this change was more pronounced in the halothane group. The results support the use of isoflurane rather than halothane for prolonged anaesthesia in respect of the synthesising function of the liver.

[The effect of rectal pH values on the absorption of methohexital]

The factors underlying the unpredictability of the pharmacokinetics of rectally administered methohexitone remain unclear. The "pH partition hypothesis" offers an explanation. We investigated six children with rectal pH values ranging from 7.5 to 9.8, who were given 25 mg/kg methohexitone 10% via the rectal route under general anaesthesia. Blood samples were taken at zero, 3, 5, 7, 10, 15, 20, 30, 40, 60, 90 and 120 min; rectal pH was measured at zero and 1 min. The methohexitone plasma levels reached a maximum (Cmax) of 2.63 micrograms/ml (median) after 17.5 min (median). The elimination half-life ranged from 37 to 218 min. No positive correlation between lower pH and better resorption (AUC and Cmax) was found. The resorption kinetics of rectally administered methohexitone cannot be explained by its electrochemical properties alone.

[Comparative study of analgesia and plasma level following rectal, intramuscular and intravenous administration of ketamine]

Ketamine 25 mg/kg was administered to five foxhounds by the intravenous, intramuscular or rectal route. Plasma concentrations were measured by gas-chromatography and analgesia was tested by two techniques. Intravenous application gave reliable analgesia and well reproducible plasma levels in all subjects. Distribution and elimination half lives were found to be 6 min and 55 min, respectively. Intramuscular injection resulted in peak-plasma levels around the twentieth minute, elimination half life was fifty-two minutes, bioavailability 90%. Analgesia proved satisfactory in four out of the five subjects and lasted longer than after intravenous injection. The rectal route produced a wide range of peak-plasma levels, the average peak appearing after 40 min. We found an elimination halflife of 43 min and a bioavailability of 30%. Analgesia was poor in four out of the five subjects. The low plasma levels following rectal application are due to the poor bioavailability and this appears to be the reason for the unsatisfactory results with this route of administration. Bioavailability depends on the site of application (drainage mainly through the vena cava or portal vein) and the pH of the rectum.

Effect of aluminum on the renal handling of phosphate in the rat

The effects of aluminum (Al) on the renal handling of phosphate (Pi) were studied by clearance techniques in the presence and absence of endogenous parathyroid hormone (PTH) and after Pi infusion. In all groups, a 1-h control period was followed by three 1-h experimental periods in which controls continued to receive saline and experimental animals received Al. Glomerular filtration rate, urine flow rate, and plasma sodium (Na) were not significantly changed between periods in any group. In the presence of endogenous PTH, the fractional excretion of phosphate (FEPi) increased significantly after 3 h of Al infusion (6.1 +/- 0.9 to 15.0 +/- 1.8%, P less than 0.05, n = 8), but not in controls (n = 7), while plasma calcium and Pi decreased, suggesting a PTH effect. However, in acutely thyroparathyroidectomized (TPTX) rats the FEPi also increased significantly after 3 h of Al infusion (4.3 +/- 3.0 to 10.6 +/- 4.2%, P less than 0.05, n = 7), but not in controls (n = 6). In TPTX rats infused with Pi where plasma Pi was increased to 10 mg/dl, FEPi increased significantly after 2 and 3 h of Al (7.0 +/- 1.4 to 15.5 +/- 2.1 to 16.9 +/- 2.2%, P less than 0.01, n = 15), but not in controls (n = 8). In this group, changes in FEPi were accompanied by a small but significant increase in FENa but not urinary cAMP. Blood pH was not significantly different between saline and Al-infused rats. These studies indicate that Al infusion inhibits renal Pi reabsorption by a mechanism independent of PTH, blood pH, or cAMP.

Antibody to hepatitis A and hemodialysis

Antibody to hepatitis A virus (anti-HAV) was surveyed in 469 patients from 20 of 31 Michigan hemodialysis units, during spring 1978. The mean point prevalence of anti-HAV was 59.5% and within the 20 individual units ranged from zero to 100%. For the entire survey population, the point prevalence of anti-HAV was significantly greater with increasing age, among blacks, and in individuals with hypertension as their underlying renal disease. Anti-HAV was independent of sex, duration of dialysis, or the presence of either hepatitis B surface antigen or its associated antibody. Within individual units, anti-HAV prevalence was associated with a higher mean patient age but not with dialysis unit size, mean duration of dialysis therapy, race, or prevalence of hepatitis B markers among patients or staff. These data support reports that transmission of the hepatitis A virus is neither associated with hemodialysis therapy nor routinely spread by parenteral mechanisms as observed in hepatitis B virus transmission.

Fluid administration and bronchopulmonary dysplasia. The lack of an association

The fluid intake of 38 surviving infants with severe respiratory distress syndrome was evaluated. There were no substantial difference in fluid administration between those in whom bronchopulmonary dysplasia (BPD) developed and those in whom it did not. The factors that were associated with the development of BPD were the degree of prematurity, patent ductus arteriosus, pulmonary air leak, exposure to high concentrations of oxygen, and use of ventilation at faster rates.

Hyaline membrane disease. A controlled study of inspiratory to expiratory ratio in its management by ventilator

Sixty-nine neonates with severe hyaline membrane disease (HMD) were mechanically ventilated using either a 1:2 or a 2:1 inspiratory to expiratory (I/E) ratio. Survivors in the 2:1 group required a lower fraction of oxygen in the inspired air (FiO2) and lower end-expiratory pressure to achieve satisfactory oxygenation. During the first week of life, time of exposure to FiO2 greater than 0.60 while being mechanically ventilated was 29.7 +/- 7.5 hours for the 1:2 group and 6.6 +/- 2,7 hours for the 2:1 group, while time of exposure to end-expiratory pressure greater than 3 cm H2O was 49.4 +/- 7.9 hours for the 1:2 group and 13.4 +/- 7.4 hours for the 2:1 group. Mortality and the incidence of air leak, patent ductus arteriosus, intraventricular hemorrhage, necrotizing enterocolitis, bronchopulmonary dysplasia, and pulmonary hemorrhage were not different for the two groups. Using an increased I/E ratio during the acute phase of HMD improved oxygenation but did not alter morbidity or mortality.

Congenital hypothyroidism--signs and symptoms in the newborn period

Infants with athyrotic hypothyroidism usually manifest signs and symptoms of hypothyroidism prior to or during the period in the newborn nursery. These features are variable and include: prolonged gestation with large size at birth, large posterior fontanel, respiratory distress, hypothermia, peripheral cyanosis, hypoactivity, poor feeding, lag in onset of stooling, abdominal distension with vomiting, protracted icterus, and/or edema. Retrospective assessment of newborn nursery records of three infants from the Collaborative Perinatal Project who were subsequently found to have congenital hypothyroidism disclosed that they had six, eight, and nine, respectively, of these features while in the newborn nursery. Evaluation of newborn records on 12 other infants, often less complete, who were later found to have congenital hypothyroidism disclosed that each infant had from one to seven of these signs and symptoms, with an average of 3.2 per infant. Thus the most important period for clinical consideration of athyrotic hypothyroidism is in the newborn nursery to initiate early thyroid replacement therapy in affected infants.