Carrier screening for phenylketonuria: comparison of two discriminant analysis procedures

Absence of a convenient, direct enzyme assay for detecting phenylketonuria (PKU) heterozygotes has resulted in continued effort to develop an accurate and reliable procedure to discriminate the heterozygous individual from the homozygous normal. Our study compares two statistical procedures that combine the semifasting plasma phenylalanine and tyrosine concentrations with the individuals' prior probability of being a heterozygous carrier in order to discriminate carriers from noncarriers. The results of this comparison indicate that the quadratic discriminant function is superior to the linear discriminant function as a method of carrier testing both in theory and in practice. An interactive computer system is described that facilitates the clinical utilization of the quadratic discriminant function.     

The influence of steam cleaning procedures on the surface roughness of commonly used type III dental stone for the fabrication of removable dentures

doi: 10.1111/j.1741‐2358.2012.00669.x The influence of steam cleaning procedures on the surface roughness of commonly used type III dental stone for the fabrication of removable dentures Objective: This study investigated the possible detrimental effects of steam treatment on the surface of type III dental stone, which is a common laboratory material used for the construction of removable dentures. Material and Methods: Forty dental stone specimens were prepared and divided into four groups (A, B, C and D), and group A was used as the control group. The other groups were treated with steam from a standard distance for varying durations (30, 60 and 120 s). Results: The duration of steam cleaning significantly increased Ra values (F = 63.150, p = 0.000). Similarly, the duration of steam application was directly correlated with the weight changes (F = 17.721, p = 0.000). A significant amount of dental stone can be removed from the surface while treating with steam. Conclusion: These studies demonstrated that expanded periods of steam cleaning cause weight loss and abrade the surface of type III dental stones; therefore, these devices should be used with caution during denture fabrication procedures.     

The influence of hydrological regimes on sex ratios and spatial segregation of the sexes in two dioecious riparian shrub species in northern Sweden

River management practices have altered the hydrological regimes of many rivers and also altered the availability of regeneration niches for riparian species. We investigated the impact of changed hydrological regimes on the sex ratios and the Spatial Segregation of the Sexes (SSS) in the dioecious species Salix myrsinifolia Salisb.–phylicifolia L. and S. lapponum L. by studying the free-flowing Vindel River and the regulated Ume River in northern Sweden. We surveyed sex ratios of these species in 12 river reaches on the Vindel River and in 17 reaches on the Ume River. In addition, we surveyed the sex and location above mean river stage of 1,002 individuals across both river systems to investigate the SSS of both species. Cuttings were collected from male and female individuals of S. myrsinifolia–phylicifolia from both rivers and subjected to four different water table regimes in a greenhouse experiment to investigate growth response between the sexes. We found an M/F sex ratio in both river systems similar to the regional norm of 0.62 for S. myrsinifolia–phylicifolia and of 0.42 for S. lapponum. We found no evidence of SSS in either the free-flowing Vindel River or the regulated Ume River. In the greenhouse experiment, hydrological regime had a significant effect on shoot and root dry weight and on root length. Significantly higher shoot dry weights were found in females than in males and significantly different shoot and root dry weights were found between cuttings taken from the two rivers. We concluded that changed hydrological regimes are likely to alter dimensions of the regeneration niche and therefore to influence sex ratios and SSS at an early successional stage, making it difficult to find clear spatial patterns once these species reach maturity and can be sexed.     

The influence of swimming demand on phenotypic plasticity and morphological integration: a comparison of two polymorphic charr species

In northern freshwater lakes, several fish species have populations composed of discrete morphs, usually involving a divergence between benthic and limnetic morphs. Although it has been suggested that swimming demand plays an important role in morphological differentiation, thus influencing habitat selection, it is unclear how it affects reaction norms, patterns in character correlation, and levels of morphological integration. We examined whether swimming demand could induce morphological plasticity in the directions expected under divergent habitat selection, and evaluated its influence on the morphological integration in Arctic charr (Salvelinus alpinus) and brook charr (S. fontinalis), two congeneric species exhibiting conspicuous and subtle resource polymorphism, respectively. We found that changes in morphology were induced by differential swimming demands in both species. The length of the pectoral fin was the character that responded most strongly according to the predicted morphological expectations under divergent habitat selection. High levels of morphological plasticity, relatively low levels of integration, and differences found in the morphological correlation structure among water velocity treatments suggest that constraints on morphological change are unlikely in either species, thus allowing great potential for phenotypic flexibility in both species. The magnitude of character integration, however, was larger for Arctic charr than for brook charr. This latter result is discussed in the light of the differences in the level of polymorphism between the two species in the wild. The results of the present study indicate that swimming demand alone may not be sufficient to generate the polymorphism encountered in nature. Given that both diet and swimming demands can induce morphological changes, it would be important to conduct experiments targeting the interaction between the morphological modules related to trophic and swimming demands.     

Efficiency and safety of inhalative sedation with sevoflurane in comparison to an intravenous sedation concept with propofol in intensive care patients: study protocol for a randomized controlled trial

ABSTRACT: BACKGROUND: State of the art sedation concepts on intensive care units (ICU) favor propofol for a time period of up to 72 h and midazolam for long-term sedation. However, intravenous sedation is associated with complications such as development of tolerance, insufficient sedation quality, gastrointestinal paralysis, and withdrawal symptoms including cognitive deficits. Therefore, we aimed to investigate whether sevoflurane as a volatile anesthetic technically implemented by the anesthetic-conserving device (ACD) may provide advantages regarding 'weaning time', efficiency, and patient's safety when compared to standard intravenous sedation employing propofol. Method/Design This currently ongoing trial is designed as a two-armed, monocentric, randomized prospective phase II studies including intubated intensive care patients with an expected necessity for sedation exceeding 48 h. Patients are randomly assigned to either receive intravenous sedation with propofol or sevoflurane employing the ACD. Primary endpoint is the comparison of the 'weaning time' defined as the time required from discontinuation of the sedating agent until sufficient spontaneous breathing occurs. Moreover, sedation depth evaluated by Richmond Agitation Sedation Scale and parameters of patient's safety (that is, vital signs, laboratory monitoring of organ function) as well as the duration of mechanical ventilation and overall stay on the ICU are analyzed and compared. An intention-to-treat analysis will be carried out with all patients for whom it will be possible to define a wake-up time. In addition, a per-protocol analysis is envisaged. Completion of patient recruitment is expected by the end of 2012. DISCUSSION: This clinical study is designed to evaluate the impact of sevoflurane during long-term sedation of critically ill patients on 'weaning time', efficiency, and patient's safety compared to the standard intravenous sedation concept employing propofol. Trial registration EudraCT2007-006087-30; ISCRTN90609144.     

Comparison of different anaesthetic methodologies for sedation during in vitro fertilization procedures: effects on patient physiology and oocyte competence

The main goal of the present retrospective study is to compare four analgesic methodologies (EMLA cream, propofol, thiopental sodium, sevoflurane) for in vitro fertilization (IVF) oocyte retrieval. We found that most anaesthetic parameters were not significantly different among all treatments. In contrast, significant differences were revealed in all groups for total number of oocytes retrieved per patient, rate of mature oocytes at metaphase II stage (MII) and percentage of fertilization and embryo development. In the EMLA cream and thiopental sodium groups we observed the highest percentage of MII oocytes (P < 0.001). Fertilization rate in the EMLA and sevoflurane groups were similar but significantly higher than the propofol and thiopental sodium groups (P < 0.001). The highest rate of anomalous fertilization was observed in the propofol group. Rate of embryo development was similar in all groups but sevoflurane group had a lower percentage of good embryos. In conclusion, by comparing different anaesthetic techniques with different mechanisms of action and administration, potential negative effects of these drugs on the initial stages of human IVF procedure were revealed. Therefore, a local anaesthetic cream is proposed as an acceptable alternative option for anaesthesia during transvaginal oocyte retrieval.     

The effect of two different doses of oral clodronate on pain in patients with bone metastases

The aim of this study was to evaluate the efficacy of low dose oral clodronate in palliation of pain arising from bone metastases (BM) and to determine the optimal oral clodronate dose which inhibits osteolysis caused by tumor. Fifty patients with bone pain caused by BM were included in this study. All were receiving antitumor chemotherapy or hormonal therapy. The patients were randomized into three groups according to the dose of clodronate. Groups A and B were given 800 mg/d and 1600 mg/d of oral clodronate respectively for 3 months. Group C was the control group. The effect of clodronate in pain palliation was evaluated with pain score, performance status, and changes in analgesic use. The effect on osteolysis was examined with urinary calcium, hydroxyproline (OHP) and serum cross-linked carboxyterminal telopeptide region of type I collagen (ICTP) levels. Group A contained 16 patients, and groups B and C contained 17 patients each. After 3 months use of oral clodronate, significant decrease in the pain score of groups A and B was noted when, compared to group C (P=0.024 andP=0.007, respectively) The analgesic use of 11 patients in group A (69%) and 8 patients in group B (47%) was decreased, but only the decrease in group A was statistically significant (P=0.038). Pain score increased in 5 patients in group C (29%), and 3 patients in groups A (19%) and B (18%) each. Urinary calcium, OHP and serum ICTP levels increased in group C and decreased in groups A and B, but only the decrease of urinary calcium levels of group B was significant (P=0.003). In conclusion, low dose (800 mg/d) oral clodronate seems to be as effective as standard dose (1600 mg/d) in palliation of bone pain secondary to BM.     

The influence of resident adults on recruitment: a comparison to settlement

For species recruiting into established sessile communities, the adult colonies and individuals already present form a significant part of the environment and have the potential to alter both larval settlement rates and post-settlement mortality. Settlement rates can be reduced by predation on larvae, by the removal or addition of substratum space, or by stimulation or prohibition of larvae from settling on adjacent substratum. Once attached, the recruiting individual can still be influenced by predation or overgrowth by residents, by the added physical structure for firmer attachment, or by being camouflaged from motile predators. To examine those processes by which residents affect recruitment we exposed experimental substrata with three densities of adults of a single species at a site in eastern Long Island Sound, USA for a 1-wk period. Seven different species of common invertebrates were used in nine separate experiments. The major effect of most resident species was the usurpation of space and the restricting of recruitment to adjacent unoccupied areas. This was particularly true for resident ascidians and bryozoans, but less so for barnacles and oysters. In fact several species recruited in higher densities on or next to oysters and barnacles. Comparison to 1-day settlement experiments indicated that the encrusting ascidian species Diplosoma and possibly Botryllus reduced recruitment relative to settlement, probably by overgrowing newly-settled individuals. However, in the presence of most resident species, recruitment patterns were not greatly different from settlement patterns, indicating that the effects of the attached community on recruitment may result from influences on settlement.     

Effects of oral clonidine on plasma 3-methoxy-4-hydroxyphenethyleneglycol (MHPG) in man: Preliminary report

Repeated (N=15) administration of clonidine (0,1,5 μg/kg,p.o.) to three normotensive male subjects resulted in significant decreases in plasma free 3-methoxy-4-hydroxyphenethyleneglycol (MHPG) at three hours for both the 1 μg/kg dose (p < .05) and the 5 μg/kg dose (p < .01) when compared to concentrations following placebo. The mean decrement in plasma free MHPG following a 5 μg/kg dose was 36%. Systolic blood pressure fell a mean of 17 mmHg after 1 μg/kg and 37 mmHg after 5 μg/kg of clonidine. The application of a clonidine challenge test to assess noradrenergic receptor sensitivity $\text{in}$$\text{vivo}$ is discussed.     

Multi-laboratory evaluation of procedures for reducing the volume of cord blood: influence on cell recoveries

BACKGROUND: Various procedures can be used to isolate stem and progenitor cells from cord blood. This study evaluated the hydroxyethyl starch sedimentation (HES) with two centrifugation steps, and the top and bottom (T&B) isolation of buffy coat following a single centrifugation, and two filter systems for processing cord blood, one developed by Asahi Kasei Medical (filter A) and the second by Terumo (filter B). METHODS: Each of seven laboratories was randomly assigned the evaluation of either the HES or T&B method and one of the filter methods (n=8 cord blood units, per laboratory, for each method). The leukocyte-containing fraction with the stem/progenitor cells was recovered from the filters by reverse flushing. Utilizing the routine traditional processing and testing procedures of each laboratory, in vitro parameters were determined, with samples obtained after collection, after processing and after freezing/thawing. The results were expressed as the percentage recovery of viable cells in processed vs. collected samples (performance 1; PF1) and in thawed vs. processed samples (performance 2; PF2). The composite results obtained by the seven laboratories were summarized. RESULTS: The median PF1 percentage recovery of total nucleated cells (TNC) was comparable with both traditional methods (HES 79%, T&B 86%) and statistically reduced with both filtration procedures (filter A 58%, filter B 61%). Mononuclear cell (MNC) PF1 recovery was highest statistically with the T&B method (91%) and reduced on using filter A (77%) and filter B (70%) and the HES method (72%). CD34+ cell recovery was judged to be essentially comparable with the four methods, although the range of unit recoveries differed. The percentage recovery of TNC and MNC in PF1 was influenced by the volume of the collected cord blood, especially with use of the filtration procedures. This correlated with TNC content. A greater percentage of red cells and platelets was removed during processing with both filter methods. The time to process cord blood preparations with filter A was significantly shorter than the other methods. Processing with the HES method took the longest time. The recoveries for TNC, MNC and CD34+ cells in PF2 did not appear to be influenced by the specific processing procedure. DISCUSSION: These data indicate that filters that capture stem and progenitor cells may be an appropriate methodology for processing cord blood collected for banking.     

The impact of experimental fire regimes on seed production in two tropical eucalypt species in northern Australia

Abstract This study investigated the effect of three experimental fire regimes on the fecundity, ovule development and seedfall of two common wet-dry tropical savanna eucalypts, Eucalyptus minima and Eucalyptus tetrodonta, in northern Australia. Both species flower early in the dry season and ovule development occurs during the dry season. This coincides with a period of frequent fires. The three fire regimes considered were applied for four years between 1990 and 1994. These regimes were (i) Unburnt, (ii) Early, fires lit early in the dry season, and (iii) Late, fires lit late in the dry season. The treatments were applied to nine catchments (15–20 km²) with each fire regime replicated three times. Fire intensity typically increases as the dry season proceeds. Therefore, early dry season fires generally differ from late dry season fires in both their intensity and their timing in relation to the reproductive phenology of the eucalypts. Late dry season burning significantly reduced the fecundity of both species, whereas Early burning had no significant effect. Ovule success was significantly reduced by the Early burning for both species. The Late burning significantly reduced ovule success in E. tetrodonta, but not in E. miniata. The results suggest that fire intensity and fire timing may both be important determinants of seed supply. Fire intensity may be a determinant of fecundity, whereas fire timing in relation to the reproduction phenology may have a significant impact on ovule survival. Both fire regimes resulted in a substantial reduction in seed supply compared with the Unburnt treatment. This may have a significant impact on seedling regeneration of these tropical savanna eucalypts.     

The influence of cavity shape on the stresses in composite dental restorations: a finite element study

Dental restoration adhering to the cavity exhibits fundamentally different load transfer mechanisms from non-adhering restorations. It is therefore questionable that traditional cavity designs are optimal from a purely mechanical point of view when working with composite materials. Drawing from general engineering experience, it can be hypothesised that smooth, well rounded designs with bevelled margins are superior. A finite element model is used in the present investigation to determine the stress field in four different cavity designs as it develops during the curing of the restoration. The results show that a significant reduction of the stress along the adhesive interface between the tooth and the restoration can be achieved through the use of a rounded cavity shape. They also show that the adoption of bevelled margins leads to a reduction of the stress concentration at this location. These results are confirmed by a set of experimental results published in the literature. It is concluded that adhering restorations will perform better from a mechanical point of view if an appropriate cavity shape is selected.     

Tranexamic acid and bleeding in patients treated with non-vitamin K oral anticoagulants undergoing dental extraction: The EXTRACT-NOAC randomized clinical trial

BackgroundOral bleeding after dental extraction in patients on non-vitamin K oral anticoagulants (NOACs) is a frequent problem. We investigated whether 10% tranexamic acid (TXA) mouthwash decreases post-extraction bleeding in patients treated with NOACs.Methods and findingsThe EXTRACT-NOAC study is a randomized, double-blind, placebo-controlled, multicenter, clinical trial. Patients were randomly assigned to 10% TXA or placebo mouthwash and were instructed to use the mouthwash once prior to dental extraction, and thereafter for 3 times a day for 3 days. The primary outcome was the number of patients with any post-extraction oral bleeding up to day 7. Secondary outcomes included periprocedural, early, and delayed bleeding, and the safety outcomes included all thrombotic events. The first patient was randomized on February 9, 2018 and the last patient on March 12, 2020. Of 222 randomized patients, 218 patients were included in the full analysis set, of which 106 patients were assigned to TXA (74.8 (±8.8) years; 81 men) and 112 to placebo (72.7 (±10.7) years; 64 men). Post-extraction bleeding occurred in 28 (26.4%) patients in the TXA group and in 32 (28.6%) patients in the placebo group (relative risk, 0.92; 95% confidence interval [CI], 0.60 to 1.42; P = 0.72). There were 46 bleeds in the TXA group and 85 bleeds in the placebo group (rate ratio, 0.57; 95% CI, 0.31 to 1.05; P = 0.07). TXA did not reduce the rate of periprocedural bleeding (bleeding score 4 ± 1.78 versus 4 ± 1.82, P = 0.80) and early bleeding (rate ratio, 0.76; 95% CI, 0.42 to 1.37). Delayed bleeding (rate ratio, 0.32; 95% CI, 0.12 to 0.89) and bleeding after multiple extractions (rate ratio, 0.40; 95% CI, 0.20 to 0.78) were lower in the TXA group. One patient in the placebo group had a transient ischemic attack while interrupting the NOAC therapy in preparation for the dental extraction. Two of the study limitations were the premature interruption of the trial following a futility analysis and the assessment of the patients’ compliance that was based on self-reported information during follow-up.ConclusionsIn patients on NOACs undergoing dental extraction, TXA does not seem to reduce the rate of periprocedural or early postoperative oral bleeding compared to placebo. TXA appears to reduce delayed bleeds and postoperative oral bleeding if multiple teeth are extracted.Trial registrationClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT03413891","term_id":"NCT03413891"}}NCT03413891EudraCT; EudraCT number:2017-001426-17; EudraCT Public website: eudract.ema.europa.eu.

Anna Ockerman and co-workers evaluate mouthwash containing tranexamic acid for people on non-vitamin K oral anticoagulants undergoing dental extraction.     

The influence of oral anatomy on prey selection during the ontogeny of two percoid fishes,Lagodon rhomboides and Centropomus undecimalis

Synopsis Ontogenetic increases in mouth size and changes in dentition of percoid fishes may affect the size and species of prey selected, thus influencing the fundamental trophic niche. To examine the influence of oral anatomy on prey selectivity by pinfish, Lagodon rhomboides, and snook, Centropomus undecimalis, two co-occurring percoid fishes with contrasting mouth morphologies, the mouth size, dentition, stomach contents, and available prey during ontogeny were quantified. Based on the presence of prey fragments in stomach contents and direct behavioral observation, prey were categorized by the feeding mode used during capture (suction/ramfeeding or biting). Centropomus has a larger size-specific gape than Lagodon during all ontogenetic stages. Although both feeding modes were used by Lagodon during ontogeny, the amount of prey captured using suction/ram-feeding declined and the amount of prey captured by biting increased with standard length. This change in feeding mode was associated with a change in incisor shape and width: Lagodon < 39 mm SL possessed narrow, pointed incisors and strongly selected amphipods, which are captured using suction/ram-feeding; Lagodon> 40 mm SL possessed wide, flat-topped incisors and significantly increased their selectivity for polychaetes, which are captured by biting. Centropomus used ram-feeding to capture prey at all ontogenetic stages. Size-selective feeding by Centropomus was apparent but could not be due to gape-limitation alone, because average prey body depth was only 45% of gape and was not proportional to absolute mouth size increase during ontogeny. Dietary diversity was greatest during the transition from suction/ram-feeding to biting in Lagodon. Lagodon had a higher dietary diversity at all ontogenetic stages than Centropomus, due in part to Lagodon's use of multiple feeding modes.     

Undergraduate dental education on oral appliance therapy for obstructive sleep apnea at The University of British Columbia

Sleep and Biological Rhythms - The updated practice parameters from the American Academy of Sleep Medicine in 2006 have concluded that oral appliances are indicated for mild to moderate obstructive...     

Exotic invasive black willow (Salix nigra) in Australia: influence of hydrological regimes on population dynamics

Floodplain vegetation occupies disturbance prone habitats vulnerable to exotic plant invasion. Black willow (Salix nigra Marshall) is a flood-tolerant tree native to the southeastern United States and recently invasive in Australia, where it is considered detrimental to riparian environments. Effective management of S. nigra requires understanding the impacts of hydrological conditions on population dynamics at each stage of the plant’s life cycle. The influence of inundation events (timing, duration, and recession rates) on S. nigra stand dynamics and relative growth rate (RGR) was quantified across a hydrological gradient on the shorelines of Blowering Dam reservoir (NSW, Australia). Successful recruitment (sexual and asexual) and establishment is highly dependent on the position of S. nigra recruits above reservoir water levels and exposure to flooding during the first few years of establishment. Recruitment was ubiquitous along the hydrological gradient but a greater number of asexual recruits were found at higher elevations where inundation events are less frequent. Juvenile mortality was highest at lower elevations, which experienced greater depth and duration of inundation. Mean RGR was greatest in S. nigra stands experiencing no inundation over the study period and declined as inundation duration increased. Flooding events inhibit adult growth, but create suitable conditions for seedling recruits, provided the depth and duration of the flood does not exceed complete submersion for more than 30 days. To investigate relative tolerance to water table decline rooted S. nigra cuttings were grown in rhizopods, controlled growth devices that allow water-table manipulation. Water-table decline rates of 0, 1, 2, 4, and 8 cm day⁻¹ were applied and the response of leaf abscission measured. S. nigra cuttings were not significantly impacted at water-table decline rates of between 1 and 4 cm day⁻¹. Spatial location of S. nigra recruits in Australian floodplains represents a trade-off among hydrological conditions that promote recruitment without inducing mortality, resulting in a narrow spatial and temporal regeneration window critical to successful establishment. Future distribution and abundance of S. nigra in Australia will be determined by propagule availability and the degree to which current and future flow regimes create suitable hydrological conditions for successful establishment.