Overweight and obese children have lower cortisol levels than normal weight children.

AIM: The stress hormone cortisol is vital to survival, and a disturbed circadian rhythm can be deleterious to health. However, little is known about cortisol levels in healthy children. The aim of this study was to examine cortisol levels in relation to body mass index (BMI), age and sex. METHODS: Salivary samples were collected in early morning, late morning and evening, on four consecutive days, from 342 children aged 6-12 years using Salivette(®) tubes. Samples were analysed using a commercial enzyme immunoassay (EIA). School nurses measured the children's height and weight, and these measurements were used to calculate their BMI. RESULTS: The children displayed a circadian rhythm in cortisol secretion, with morning zeniths and evening nadirs. Average cortisol levels in early morning, late morning and evening were significantly lower in overweight and obese children than in their normal weight counterparts. Cortisol levels did not vary significantly with age or sex. CONCLUSION: Our findings may suggest cortisol suppression in overweight and obese children. We found no evidence that sex or age influences cortisol levels. These findings highlight the need for further research on the relationship between stress and obesity in children.

Structure and compositional characteristics of caniniform dental enamel in the tuatara Sphenodon punctatus (Lepidosauria: Rhynchocephalia).

OBJECTIVE: The evolution of dental tissues in relation to tooth function is poorly understood in non-mammalian vertebrates. We studied the dentition of Sphenodon punctatus, the sole remaining member of the order Rhynchocephalia in this light. METHODS: We examined 6 anterior maxillary caniniform teeth from adult Sphenodon by scanning electron microscopy, nano-indentation and Raman spectroscopy. RESULTS: The elastic modulus (E) for tuatara enamel was 73.17 (sd, 3.25) GPa and 19.52 +/- 0.76 Gpa for dentine. Hardness (H) values for enamel and dentine were 4.00 (sd, 0.22) and 0.63 +/- 0.02 Gpa respectively. The enamel was thin (100 gm or less), prismless and consisted of grouped parallel crystallites. Incremental lines occurred at intervals of about 0.5 to 1 rm. There were tubular structures along the enamel dentine junction running from the dentine into the inner enamel, at different angles. These were widened at their base with a smooth, possibly inorganic lining. Enamel elastic modulus and hardness were lower than those for mammals. CONCLUSIONS: The presence of enamel tubules in the basal part of the enamel along the EDJ remains speculative, with possible functions being added enamel/dentinal adhesion or a role in mechanosensation.

Aerosol transmission of foot-and-mouth disease virus Asia-1 under experimental conditions.

Foot-and-mouth disease virus (FMDV) control measures rely on understanding of virus transmission mechanisms. Direct contact between naïve and infected animals or spread by contaminated fomites is prevented by quarantines and rigorous decontamination procedures during outbreaks. Transmission of FMDV by aerosol may not be prevented by these control measures and this route of transmission may allow infection of animals at distance from the infection source. Understanding the potential for aerosol spread of specific FMDV strains is important for informing control strategies in an outbreak. Here, the potential for transmission of an FMDV Asia 1 strain between pigs and cattle by indirect aerosol exposure was evaluated in an experimental setting. Four naïve calves were exposed to aerosols emitted from three infected pigs in an adjacent room for a 10h period. Direct contact between pigs and cattle and fomite transfer between rooms was prevented. Viral titres in aerosols emitted by the infected pigs were measured to estimate the dose that calves were exposed to. One of the calves developed clinical signs of FMD, whilst there was serological evidence for spread to cattle by aerosol transmission in the remaining three calves. This highlights the possibility that this FMDV Asia 1 strain could be spread by aerosol transmission given appropriate environmental conditions should an outbreak occur in pigs. Our estimates suggest the exposure dose required for aerosol transmission was higher than has been previously quantified for other serotypes, implying that aerosols are less likely to play a significant role in transmission and spread of this FMDV strain.

Performance of para-Pak Ultra ECOFIX compared with Para-Pak Ultra formalin/mercuric chloride-based polyvinyl alcohol for concentration and permanent stained smears of stool parasites.

ECOFIX is a mercury and formalin-free fecal preservative that can be used for concentration of stool specimens and preparation of permanently-stained slides. In this study, the standard two-vial ParaPak Ultra system was compared with ECOFIX Ultra for the detection of intestinal parasites. A total of 261 specimens in 92 sets (77 with 3 specimens, 15 with 2 specimens) were collected in ECOFIX, formalin, and low viscosity polyvinyl alcohol (LV-PVA). Concentrations were performed from ECOFIX using Hemo-De and saline and from formalin using ethyl acetate and formalin. To prepare permanently-stained smears, ECOSTAIN (a modification of Wheatley's trichrome stain) was used on ECOFIX material and Wheatley's trichrome stain was used on specimens preserved in PVA. A total of 157 protozoa and helminths were detected; 132 (84.1%) were recovered in formalin/PVA and 129 (82.2%) in ECOFIX. In permanently-stained smears, 139 protozoa were observed, 116 (83.5%) in PVA-preserved material and 117 (84.2%) in ECOFIX. Fecal concentration yielded 111 parasites (103 protozoa and 8 helminths), of which 98 (88.3%) were detected in formalin-fixed stool and 48 (43.2%) in ECOFIX. Significantly fewer ECOFIX-preserved concentrates were positive for Blastocystis hominis (35 versus 15, p-value <0.001) and Endolimax nana (19 versus 2, p-value <0.001). In conclusion, use of the ECOFIX Ultra collection device in combination with ECOSTAIN resulted in largely comparable recovery of enteric parasites to the conventional two-vial ParaPak Ultra system when both sedimentation-concentration and permanently stained smears were performed, and 2-3 specimens per patient were evaluated.

Microstructure of dental hard tissues and bone in the Tuatara dentary, Sphenodon punctatus (Diapsida: Lepidosauria: Rhynchocephalia).

The Tuatara, Sphenodon, is a small reptile currently restricted to islands off the coast of New Zealand where it feeds mainly on arthropods. A widely held misconception is that 'Sphenodon does not have real teeth' and instead possesses 'serrations on the jaw bone'. One hatchling and one adult dentary were examined under SEM. Two longitudinal ground sections 100-microm thick were prepared through a lower canine tooth and its supporting tissues. There was clear evidence of aprismatic enamel (primless enamel) containing dentine tubules crossing the EDJ, dentine, cementum and a basal-bone attachment. Enamel increments averaged approximately 3 microm/day and extension rates were approximately 30 microm/day. The base of the tooth consisted of basal attachment bone that graded from few cell inclusions to lamella or even Haversian-like bone with evidence of remodeling. A string of sclerosed pulp-stone like structures filled the pulp chamber and were continuous with the bone of attachment. Bone beneath the large central nutrient mandibular (Meckel's) canal was quite unlike lamella bone and appeared to be fast growing and to contain wide alternating cell-rich and cell-free zones. Bone cells were rounded (never fusiform) and had few, if any, canaliculi. The dentine close to the EDJ formed at about the same rate as enamel but also contained longer period increments approximately 100 microm apart. These were spaced appropriately for monthly lunar growth bands, which would explain the basis of the banding pattern observed in the fast growing basal bone beneath the Meckel's canal.

Salivary cortisol response in mother-infant dyads at high psychosocial risk.

OBJECTIVES: The aim of the present study was to investigate the adrenocortical response to diaper change in mother-infant dyads with psychosocial risk factors. MATERIAL AND METHODS: Twenty-two mother-infant pairs with well-defined psychosocial problems were included. The mother-infant pairs were treated for 6 weeks in a daycare programme to improve attachment. Salivary cortisol was measured before and after a diaper change during the first and last weeks of enrollment in the programme. Mothers' sensitivity towards their infants' signals was measured using a scale from 1 (highly insensitive) to 9 (highly sensitive) according to Ainsworth. RESULTS: Median salivary cortisol increased in 15 out of 22 infants after the first diaper change. The increase was most pronounced in the group of infants below 3 months of age (n = 15) where median salivary cortisol increased 170% after the first diaper change (P < 0.05) and decreased 19% after the last diaper change (not significant). Out of these 15 infants, 11 showed an increase in salivary cortisol in response to the first diaper change while four out of 15 did so in response to the last diaper change (P < 0.05). The salivary cortisol response did not change over time in infants aged 3 months or above. A mother's sensitivity to her child increased significantly (P < 0.001) from the first to the last week. In mothers, median salivary cortisol decreased 38% after the first diaper change (P < 0.05) and 57% after the last diaper change (P = 0.001). DISCUSSION: A diaper change is normally not perceived as stressful. The stress response caused by a diaper change may illustrate an insufficiency in the mother-infant relationship before treatment. Professional support improved the mothers' sensitivity and stabilized the stress response to diaper change in the youngest infants.

Saliva collection using cotton buds with wooden sticks: a note of caution.

The aims of the present study were to investigate whether the cotton-tipped applicators (cotton buds) used to collect saliva in infants can be stored un-centrifuged prior to cortisol analysis, and to test whether there is any difference in results between wooden and plastic-shafted sticks. Saliva was collected from 10 healthy adults using 6 cotton buds, i.e. 3 with wooden sticks and 3 with plastic sticks. The samples were then centrifuged at three different time-points: immediately after collection, after 24 h and after 48 h. Using cotton buds with wooden sticks, median salivary cortisol was significantly lower after 24 h (40 %) (p<0.001) and after 48 h (49 %) (p<0.001) of storage than it was of the samples centrifuged immediately. There was no significant difference between the samples centrifuged immediately and those centrifuged after 24 h and 48 h when saliva was collected using the cotton buds with plastic sticks. It is concluded that cotton buds with wooden sticks should not be used in studies of salivary cortisol unless it is possible to centrifuge the saliva immediately. Moreover, it is inadvisable to alternate between cotton buds with wooden and plastic sticks in the same study when collecting saliva for analysis of cortisol.

Salivary cortisol and administration of concentrated oral glucose in newborn infants: improved detection limit and smaller sample volumes without glucose interference.

Newborn infants are subject to repetitive painful and stressful events during neonatal intensive care. When the baby attempts to cope with a stressful situation the hypothalamus-pituitary-adrenal axis is activated, releasing cortisol. The free cortisol response is optimally measured in saliva and saliva samples can be taken easily and without pain. However, saliva is very scarce in infants and saliva stimulants can interfere with analytical methods. Nowadays, sweet solutions are frequently administered to neonates prior to a disturbing procedure in order to reduce pain. The possible interference of sweet solutions with the measurement of salivary cortisol has not yet been documented. The aims of the present study were to further improve the detection limit of the radioimmunoassay used for cortisol analysis and to determine the degree of interference of high concentrations of glucose with the analytical method. By decreasing incubation temperature and prolonging the incubation time it was possible to improve the detection limit of the radio immunoassay (RIA) to 0.5 nmol/L at the same time as the sample volume was decreased to 10 microL saliva. Saliva was collected from full-term and preterm babies and was sufficient for analysis in 113 out of 116 (97%) samples. Glucose in the concentrations and amounts commonly used for pain relief did not interfere with the RIA method. In conclusion, it is feasible to collect microlitre volumes of saliva and analyse even very low concentrations of cortisol in newborns. It is also possible to offer the baby oral glucose prior to a painful procedure and still reliably measure salivary cortisol.

Neonatal salivary cortisol in response to heelstick: method modifications enable analysis of low concentrations and small sample volumes.

Measuring cortisol in saliva offers important advantages compared to measurement in plasma or serum. However, the sampling procedure and also the detection limit cause problems, especially in paediatric and neonatal care. We describe a simple and efficient sampling procedure, together with a modification of a radioimmunoassay, which enables analysis of low (down to 1 nmol/L) concentrations of salivary cortisol (10 times lower detection limit than in the original procedure). This setting was used in studying salivary cortisol concentrations before and after heelstick on healthy newborn infants. A significant rise (median 81%; p<0.01) in salivary cortisol as response to this invasive stressor was noted.

Clinical and histologic appearance in enamel of primary teeth in relation to neonatal blood ionized calcium values.

The purpose of this investigation was to study the relationship between low values of blood ionized calcium measured in the first days of life postpartum and the clinical and histologic appearance of enamel of primary teeth. Twenty-five healthy children selected on the basis of optimality with known blood values of ionized calcium from the first days of life participated in a dental examination at the age of 5 yr. Twenty-four of the children contributed one exfoliated tooth each, which was histologically examined. The infants had lower mean values of ionized blood calcium on days 1 and 3 than day 5 postpartum. Thirteen of the 25 children had enamel aberrations, mainly on one tooth each. The histologic examination showed normal overall enamel morphology. The neonatal line was present in all teeth, and these lines were mostly thin. The registered findings about the enamel morphology could not, in any case, be correlated with the measured values of neonatal blood ionized calcium.

Reconstitution of photosynthetic energy conservation. II. Photophosphorylation in liposomes containing photosystem-I reaction center and chloroplast coupling-factor complex.

Photophosphorylation has been reconstituted in a liposomal system containing reaction centers of photosystem I and coupling-factor complex, both highly purified from spinach chloroplasts. This energy-converting model system was put together by diluting the preparation of the coupling-factor complex with an aqueous suspension of proteolipid vesicles, preformed from photosystem-I reaction centers and soybean phospholipids by sonication. In the presence of reduced N-methyl-phenazonium methosulfate the system catalyzed photophosphorylation with rates up to 50 mumol ATP formed x mg chlorophyll-1 x h-1, which was sensitive to uncouplers and to N,N'-dicyclohexyl-carbodiimide. The properties of the system in comparison to chloroplasts is discussed.

Clinical and histologic appearance in enamel of primary teeth from children with neonatal hypocalcemia induced by blood exchange transfusion.

This investigation was undertaken to study the clinical and histologic appearance of deciduous enamel from 11 infants who were subjected to blood exchange transfusions (ET) during the first days of life. As a result of the treatment they had a mean of 3 consecutive hypocalcemic days. At the age of 5 years a dental examination of their primary teeth was performed. Four of the children had clinically recorded enamel aberrations correlated with the neonatal period. Exfoliated teeth were then examined histologically. All had a normal major enamel morphology, and the neonatal line was present in all teeth. Histologically investigated teeth with enamel hypoplasia had the aberrations located close to the neonatal line. The conclusions drawn from this study are that hypocalcemia caused by ET in the newborn period did not affect the width of the neonatal line or the major enamel morphology to any extent. Enamel aberrations occurred only when four or more ETs were performed.

Rapid transbilayer movement of fluorescent phospholipid analogues in the plasma membrane of endocytosis-deficient yeast cells does not require the Drs2 protein.

Evidence is presented that endocytosis-deficient Saccharomyces cerevisiae end4 yeast cells rapidly internalize the fluorescent phospholipid analogues 1-palmitoyl-2-{6-[7-nitro-2,1, 3-benzoxadiazol-4-yl(NBD)amino] caproyl}phosphatidylcholine (P-C6-NBD-PtdCho) and P-C6-NBD-phosphatidylserine (P-C6-NBD-PtdSer). Both analogues redistributed between the exoplasmic and cytoplasmic leaflet with a half-time of < 15 min at 0 degrees C. The plateau of internalized analogues was about 70%. Transbilayer movement is probably protein-mediated, as the flip-flop of both analogues was very slow in liposomes composed of plasma-membrane lipids. Rapid analogue internalization was not abolished on depletion of intracellular ATP by about 90%. For P-C6-NBD-PtdCho only was a moderate decrease in the plateau of internalized analogues of about 20% observed, while that of P-C6-NBD-PtdSer was not affected. The Drs2 protein plays only a minor role, if any, in the rapid transbilayer movement of analogues in S. cerevisiae end4 cells. In S. cerevisiae end4 Deltadrs2 cells harbouring both an end4 allele and a drs2 null allele, about 60% and 50% of P-C6-NBD-PtdCho and P-C6-NBD-PtdSer, respectively, became internalized within 15 min at 0 degrees C. The preferential orientation of P-C6-NBD-PtdSer to the cytoplasmic leaflet is in qualitative agreement with the sequestering of endogenous phosphatidylserine to the cytoplasmic leaflet, as assessed by binding of annexin V. Virtually no binding of annexin V to spheroplasts of the parent wild-type strain or the mutant strains was observed. Likewise, no difference in the exposure of endogenous aminophospholipids to the exoplasmic leaflet between these strains was found by labelling with trinitrobenzenesulfonic acid. Thus, lipid asymmetry, at least of aminophospholipids, was preserved in S. cerevisiae end4 cells independently of the presence of the Drs2 protein.

Improved maxillary stability with modified Lefort I technique.

This modification of the LeFort I osteotomy places the horizontal bony cut higher and into the dense cortical bone of the maxillozygomatic complex. It gives greater stability and also provides a more solid bony base for intraosseous wiring of the mobilized segment. This usually eliminates the need for dento-osseous or maxillomandibular fixation, and the segments appear to solidify more quickly. Over the last year, we have used this technique in 23 cases (four maxillary advancements, seven one-piece maxillary intrusions, and 12 segmental maxillary intrusions) with very favorable results. This modification has given us greater control and stability, especially in combined maxillary and mandibular osteotomies.