Social-ecological assessment of Lake Manyara basin, Tanzania: A mixed method approach.

The social-ecological system of the Lake Manyara basin (Northern Tanzania), a UNESCO Biosphere reserve (BR) suffers from social-economic and environmental problems due to decreasing water levels, erosion and land and water use conflicts. We propose an integrated assessment of the social-ecological interactions of the area to support future sustainable management. Within the Drivers-Pressures-State-Impact-Response (DPSIR) framework an integrated literature review and several methods of knowledge collection were combined to identify future management priorities and challenges. During focus groups with farmers and pastoralists, stakeholders confirmed the role played by land use changes as driver and pressure in the landscape, e.g. through increased erosion rates and siltation of the lake. Moreover, economic and social issues were identified as prominent factors being influenced by, or influencing these processes. These statements match the scientific literature. During participatory mapping exercises different spatial and resource allocation perceptions appeared amongst pastoralists and farmers. The multidisciplinary approach proved to be useful to acquire an integrated and comprehensive understanding of the state, challenges and opportunities of Lake Manyara BR, to feed into a decision support system in service of an integrated management plan. Our assessment suggests that improved water governance in a multi-actor approach (with a focus on distribution of benefits, rights, and a specific role of the water authorities) should be a priority for future integrated management strategies. Also, awareness raising amongst decision makers, scientists and local communities is needed to demonstrate the advantages of an integrated approach. And finally, visible and fair mechanisms to share conservation revenues should be designed in a way that local benefits can be obtained together with incentive mechanisms for co-management and conservation.

Cerebrospinal fluid volume in neonates undergoing spinal anaesthesia: a descriptive magnetic resonance imaging study.

BACKGROUND: Spinal anaesthesia (SA) reduces the risk of postoperative apnoea after general anaesthesia in neonates. In 30% of patients, however, the duration of anaesthesia provided does not allow completion of surgery. When compared with term infants, formerly preterm neonates experience a shorter duration of anaesthesia after SA. A difference in the cerebrospinal fluid (CSF) volume between those two populations could explain this difference, but this has never been investigated. The study was designed to evaluate the relationship between the spinal CSF volume and patient characteristics in neonates. METHODS: Sixty-seven neonates, aged 30-60 weeks postconception, were included in this study. Their spinal CSF volumes were calculated using magnetic resonance imaging, and these volumes were plotted individually against sex, term at birth, birth weight, current gestational age, civil age, and weight. Correlations between CSF volume and these variables were investigated. RESULTS: Fifty-four neonates completed the study. The CSF volume was found to be closely and linearly correlated with weight and postconceptional age. The relationship between spinal CSF volume and weight can be described as follows: CSF volume (ml)=1.94 weight (kg)+0.13. The CSF volume was not correlated with sex, weight, or term at birth, nor with civil age. CONCLUSIONS: The amount of spinal CSF in neonates can be estimated as 2 ml kg(-1) in both term and formerly preterm neonates. A difference in the CSF volume between them does not provide an explanation for a shorter duration of SA in the latter. Our findings reinforce weight-adjusted dosage of SA in neonates.

Intraoperative use of transoesophageal Doppler to predict response to volume expansion in infants and neonates.

BACKGROUND: Volume expansion (VE) in neonates or infants during volatile anaesthesia may lead to fluid overload if inappropriate. Transoesophageal Doppler (TED), a non-invasive cardiac output monitoring technique, can provide a comprehensive estimation of the volaemic status. We evaluated whether intraoperative TED-derived parameters can predict volume responsiveness. METHODS: Neonates and infants under general anaesthesia without myocardial dysfunction were prospectively included when the attending anaesthetist, blinded to TED measurements, decided to provide VE based on clinical appreciation and standard monitoring data. Standard and TED-derived data were recorded before and after VE. After VE, patients were classified as responders and non-responders, if their indexed stroke volume (iSV) increased by more than 15% or not, respectively. The attending anaesthetist assessment of VE responsiveness was recorded at the end of VE. RESULTS: Fifty patients aged 42 (4) post-conceptional weeks were included, among which 26 (52%) were responders. Baseline iSV was the only parameter associated with VE responsiveness. Baseline iSV was fairly correlated with VE-induced changes in iSV (ρ=-0.64) and was associated with an area under the receiver operating characteristic curve of 0.90 (0.80, 0.99). Using a cut-off of 25 ml m(-2), baseline iSV predicted volume responsiveness with a sensitivity of 92% and a specificity of 83%. Attending anaesthetists' assessment of VE effectiveness agreed only moderately with TED measurements of iSV changes. CONCLUSIONS: TED-derived iSV measurement during volatile anaesthesia is useful to predict and follow VE responsiveness in neonates and infants without myocardial dysfunction.

Population pharmacokinetics of nalbuphine after surgery in children.

BACKGROUND: Nalbuphine is an opioid analgesic agent widely used for control of mild-to-severe pain. However, limited data are available on the pharmacokinetics of this drug in children. The aim of this study was to characterize the population pharmacokinetics of nalbuphine in patients with ages ranging from 1 to 11 yr and to identify patient characteristics partially explaining inter-individual variability in nalbuphine pharmacokinetic parameters. METHODS: Twenty-two children were included in this study. They received nalbuphine after surgery by continuous infusion (loading dose, 0.2 mg kg(-1) over 10 min followed by continuous infusion of 0.8 mg kg(-1) over 24 h). If pain relief was not adequate, 0.1 mg kg(-1) bolus doses were allowed in 10 min. Eleven blood samples were collected per patient. The data were analysed by non-linear mixed-effect modelling with the use of a two-compartment structural model. RESULTS: Twenty patients completed the study. In the final model, the parameter values were standardized for a body weight of 70 kg using an allometric model. Population parameter estimates were: clearance 130 litre h(-1) 70 kg(-1), inter-compartment clearance 75.6 litre h(-1) 70 kg(-1), central volume of distribution 210 litre 70 kg(-1), and peripheral volume of distribution 151 litre 70 kg(-1). In the children of this study, total clearance expressed in litre h(-1) kg(-1) decreased significantly with increasing age and the elimination half-life significantly increased. CONCLUSIONS: The allometric power model developed in this study best reflected the data and may be useful for dose adjustment.

[Comparison of saline, air, and a mixture oxygen-nitrous oxide for endotracheal cuff tracheal tube inflation in children? A prospective randomized trial]. / Comparaison de sérum salé, d'air et d'un mélange oxygène-protoxyde d'azote pour le remplissage des ballonnets de sondes d'intubation chez l'enfant? Étude prospective randomisée.

OBJECTIVE: The purpose of the present study was to compare how many inflate and deflate are necessary to maintain the endotracheal tube cuff pressure between 15 and 35 cm H2O by using air, O2-N2O mix or saline solution. STUDY DESIGN: Randomized and prospective study. PATIENTS AND METHODS: Ninety children from 1 month to 15 years of age were included in the study. All patients were ventilated with O250%-N2O50%. Subsequently, the patients were divided in three groups: (1) Group 1: patients with air inflated cuffs; (2) Group 2: patients with O2-N2O mix inflated cuffs; (3) Group 3: patients with saline solution inflated cuffs. In all groups cuffs were inflated to reach an intracuff pressure of 20 cm H2O. The cuff pressure was then monitored every 10 minutes and adjusted to be between 15 and 35 cm H2O. Laryngeal and tracheal symptoms were noted in the recovery room. RESULTS: The three groups of patients were similar for age, weight, and sex. The length of surgery was significantly longer in Group 3. The deflate rate was higher in Group 1 (60%) than in Group 2 (10%) or 3 (3.3%) (p<0.0001). The inflate rate was higher in Group 2 (76.6%) than in Group 1 or 3 (both 3.3%) (p<0.0001). Side effects were comparable in the three groups of patients. CONCLUSION: Using air or O2-N2O mix to inflate cuffs is not reliable. SSI helps to maintain a more stable cuff pressure but monitoring is difficult and sometimes contraindicated by tracheal tubes producers. Inflating cuffs with air and regularly monitoring pressure is the most reliable and easiest technique.

[Continuous epidural block versus continuous psoas compartment block for postoperative analgesia after major hip or femoral surgery in children: a prospective comparative randomized study]. / Analgésie péridurale continue versus bloc continu du compartiment psoas pour l'analgésie postopératoire après chirurgie majeure du bassin ou du fémur chez l'enfant : étude prospective comparative randomisée.

BACKGROUND: Intravenous opioids and/or continuous epidural block (CEB) are used for postoperative analgesia after hip and/or femoral shaft surgery but adverse effects limit their use in children. A continuous psoas compartment block (CPCB), effective technique in adults can be an alternative. In this randomized comparative study, we wanted to evaluate CEB and CPCB in children after major hip surgery in terms of adverse events, pain relief and ropivacaine plasma concentrations. METHODS: After ethical committee and parents' approval, 40 children scheduled for hip surgery were included and randomly allocated to receive CPCB or CEB. After general anaesthesia induction, 0.5 mL/kg of 0.375% ropivacaine were injected via the epidural or lumbar plexus catheter. After surgery, 0.1 ml/kg per hour (group CPCB) or 0.2 ml/kg per hour (group CEB) of 0.2% ropivacaine was infused for 48h. Post-operative pain was evaluated using VAS or CHIPPS scores values at h1, h6, h12, h18, h24, h36 and h48, as well as doses of first line (paracetamol 15 mg/kg/6h) or second line rescue analgesia (0.2mg/kg intravenous nalbuphine), if pain score remained high after 30 mm. niflumic acid was systematically used. Adverse events were noted as well as parents' satisfaction at 48h. Ropivacaine plasma concentrations were measured four times up to 48h (h1, h6, h24 and h48) by high performance gas chromatography. RESULTS: Forty children 1 to 12 years old (CPCB=20, CEB=20) were included. The demographic data were equivalent in both groups. Postoperative analgesia was excellent for both continuous block techniques during the whole studied period. Doses of rescue analgesics were comparable in both groups at the end of the 48h. Number of children who had at least one side effect is significantly higher in CEB group. Furthermore, the number of local anaesthetic premature stops was significantly more frequent in this group. Median values of ropivacaine plasma level in CEB group were significantly higher than CPCB group at h6 and h24. Ten parents in the CEB group and 15 in CPCB group were satisfied. CONCLUSION: Continuous psoas compartment block is an effective technique of postoperative analgesia after major hip or femoral surgery in children. It equally manages postoperative pain with significantly less adverse event and decreased ropivacaine doses and plasma concentration than CEB.

[Interest of ultrasonographic guidance in paediatric regional anaesthesia]. / Intérêt de l'échographie en ALR pédiatrique.

The use of ultrasonographic guidance for regional anaesthesia has known recently a big interest in children in recent years. The linear ultrasound probes with a 25 mm active surface area (or probes with 38 mm active surface area in older children), with high sound frequencies in the range 8-14 MHz, allow a good compromise between excellent resolution for superficial structure and good penetration depths. In children, the easiest ultrasound guided blocks are axillar blocks, femoral blocks, fascia iliaca compartment blocks, ilio-inguinal blocks and para-umbilical blocks, caudal blocks. They permit a safe and easy learning curve of these techniques. The main advantage of ultrasound guided regional anaesthesia is the visualization of different anatomical structures and the approximate localization of the tip of needle. The other advantages for ultrasound guided peripheral nerve blocks in children are: faster onset time of sensory and motor block, longer duration of sensory blockade, increase of blockade quality and reduction of local anesthetic injection. The use of ultrasonographic guidance for central block allows to visualize different structures as well as spine and his content. Spinous process, ligament flavum, dura mater, conus medullaris and cerebrospinal fluid are identifiable, and give some information on spine, epidural space and the depth between epidural space and skin. At last, in caudal block, ultrasounds permit to evaluate the anatomy of caudal epidural space, especially the relation of the sacral hiatus to the dural sac and the search of occult spinal dysraphism. Benefit of this technique is the visualization of targeted nerves or spaces and the spread of injected local anaesthetic.

Population pharmacokinetics of the two enantiomers of tramadol and O-demethyl tramadol after surgery in children.

BACKGROUND: Few data are available on the stereoselective pharmacokinetics of tramadol in children. The aim of this study was to develop a population pharmacokinetic model for the (+)- and (-)-enantiomers of tramadol and its O-demethyl tramadol metabolite (M1) in children. METHODS: Twenty-five children (1-8 yr) were included in this study. Tramadol was administered after surgery by continuous infusion (loading dose, 2 mg kg(-1) i.v. over 10 min followed by continuous infusion of 8 mg kg(-1) over 24 h). If pain relief was inadequate, additional 1 mg kg(-1) i.v. bolus doses of tramadol were given over 10 min. A two-compartment structural model was used with NONMEM. RESULTS: For both enantiomers of tramadol, weight was the only patient characteristic parameter showing significant covariate effects on clearance (CL). CL increased by 5.7-6.1 litre h(-1) between 8-12 and 13-16 kg, and by 2.4-3.3 litre h(-1) between 13-16 and 17-33 kg. The rate constants associated with the metabolite elimination [0.144 h(-1), (+)-M1 and 0.18 h(-1), (-)-M1] were smaller than the elimination rate constants of the parent drugs [0.243 h(-1), (+)-tramadol and 0.241 h(-1), (-)-tramadol], suggesting that the metabolite disposition was rate-limited by its elimination. The presence of two subpopulations of patients was suspected on the basis of the observed bimodal distributions of the AUC(M1)/AUC(tramadol) ratios. CONCLUSIONS: The results of this study combine relationships between tramadol CL and patient covariates that may be useful for dose adjustment. Polymorphism is likely to contribute to the interpatient variability observed in the AUC M1/AUC tramadol ratios.

Avoiding propofol injection pain in children: a prospective, randomized, double-blinded, placebo-controlled study.

BACKGROUND: Pain on injection limits the use of propofol in children. The combination of lidocaine and propofol is widely used to reduce pain. A new solvent [medium-chain triglyceride (mct)/long-chain triglyceride (lct)] has been advocated to be less painful than standard (lct) propofol in adults, but no information is available of its usefulness in pre-school children. We designed a prospective, randomized, double-blinded, placebo-controlled study to assess injection pain with two different propofol emulsions, each given with or without lidocaine in children <7 yr. METHODS: A total of 160 ASA I-III children were randomly assigned to receive lct-propofol or mct/lct-propofol, 5 mg kg(-1), with lidocaine 10 mg ml(-1) or saline. The site and size of venous cannulation and restlessness before injection were recorded in each patient. A pain score graded 0-6 was established based on spontaneous verbal and motor reaction during injection, each graded 0-3. Kruskall-Wallis and Mann-Whitney tests were used for statistical analysis. RESULTS: Median pain scores decreased in all groups compared with lct-propofol-saline (P<0.001) and were least in the lct/mct-propofol-lidocaine group (P<0.001). Painless injection (score, 0-2) occurred in 92.5% of patients in the mct/lct-propofol-lidocaine group compared with 41-77% in the others (P<0.001). CONCLUSIONS: Mct/lct-propofol caused significantly less pain than lct-propofol in preschool children. Mixing of lidocaine with mct/lct-propofol resulted in a further significant decrease, virtually eliminating the pain on injection.

[A comparative study of the feasibility and limits of ambulatory surgery in infants under and over one year of age]. / Etude comparative de la faisabilité et des limites de la chirurgie ambulatoire chez le nourrisson et chez l'enfant de plus d'un an.

OBJECTIVE: Outpatient surgery in pediatrics is attractive for several reasons. Although 6-8 months has been generally acknowledged as the lower age limit, no minimal age has been clearly established. This study evaluated the outcomes and limits of outpatient surgery in infants from 4 months to 1 year of age. MATERIAL AND METHODS: Between 1996 and 2003, 935 patients were admitted to our hospital for outpatient surgery; of these, 152 were between 4 months and 1 year (mean: 6 months). The indications were essentially surgery to the external genitalia and surgery to remove hernias. The following were exclusion criteria: age below 4 months, ASA scores equal to or above 3, and premature birth with either respiratory distress syndrome or a near-miss of sudden death. RESULTS: More than 98% of the infants met the criteria for outpatient surgery. Cancellations (1.97 vs. 0.51%, P > 0.05), conversions to classic hospitalization (0.65 vs. 0.37%, P > 0.05), postoperative complications (0.65 vs. 0.25%, P > 0.05), rehospitalization (0.65 vs.0.25%, P > 0.05) and relapse of the initial pathology (0.65 vs. 0.63%, P > 0.05) were not more frequent in these infants than in infants over 1 year. CONCLUSION: Pediatric outpatient surgery can be proposed from the age of 4 months without increasing the postoperative risk, either anesthetic or surgical, included for selected former premature infants.

Continuous psoas compartment blocks after major orthopedic surgery in children: a prospective computed tomographic scan and clinical studies.

UNLABELLED: Femoral shaft or hip surgeries are very painful for children. We conducted both computed tomographic (CT) and clinical prospective studies to define new landmarks in children and to evaluate the effectiveness of continuous psoas compartment blocks (CPCBs) using disposable elastomeric pumps. In a preliminary CT scan study of 20 patients, the plexus depth was correlated to patient age and the optimal point of puncture for CPCB was three-quarters of the distance from the spinous process of L4 to a line parallel to the spinal column passing through the posterior superior iliac spine. In a subsequent prospective series, a CPCB was administered before surgery to 15 children for pain relief after femoral and hip osteotomies. After general anesthesia, a 0.5 mL/kg bolus of a mixture of 1% lidocaine with epinephrine (1/200.000) and 0.5% ropivacaine was injected through the CPCB catheter. After contrast media assessment of the catheter location, a disposable pump (Infusor LV); Baxter, Paris, France) with 0.2% ropivacaine was connected and pump flow was adjusted to the patient's weight (0.2 mg x kg(-1) x h(-1)). Postoperative pain was evaluated using a visual analog scale or the Children and Infants Postoperative Pain Score at hour H1, H6, H12, H18, H24, H36, and H48, and in terms of rescue analgesia, adverse events, and motor blocks. All blocks were effective during surgery. Postoperative analgesia was excellent. The median pain scores were 1 for H1 and 0 beginning H6. The motor blockade was minimal before 24 h and absent thereafter. No major adverse event was noted. Parents of 93% of the children were satisfied. We conclude that postoperative analgesia with CPCB is a very effective technique in children after major proximal lower limb orthopedic surgery. The CT scan landmarks described in this study were more medial than the conventional landmarks used in the literature. IMPLICATIONS: Continuous psoas compartment blocks provide optimal pain relief in children after major orthopedic surgery without major adverse events. The landmarks used, defined in a preliminary computed tomographic scan study, were more medial than conventional landmarks.

Predictors of handicap situations following post-stroke rehabilitation.

PURPOSE: Many stroke survivors have to cope with impairments and disabilities that may result in the occurrence of handicap situations. The purpose of the study was to explore bio-psycho-social predictors of handicap situations six months after discharge from an intensive rehabilitation programme. METHODS: At discharge from a rehabilitation programme, participants were evaluated with instruments measuring motor, sensory, cognitive, perceptual, affective and psychosocial impairments and disabilities that may play a role in the development of handicap. Some other demographic and clinical variables, and those related to rehabilitation, were also collected. Six months later, they were re-assessed in their own environment in order to document their handicap level with the Assessment of Life Habits (LIFE-H). RESULTS: One hundred and thirty-two stroke patients participated in the discharge evaluation and 102 of them also participated in the handicap measurement. Relationships between handicap level and impairments and disabilities were all statistically significant. Multiple regression analyses indicated that affect, lower extremity co-ordination, length of stay in rehabilitation, balance, age and comorbidity at the end of an intensive rehabilitation programme are the best predictors of handicap situations six months later (adjusted R(2): 68.1%). CONCLUSIONS: In spite of its exploratory nature, this study revealed that, among a substantial number of personal characteristics, some were more related to a handicap measure and have greater predictive value. Other studies should be carried out to validate these findings and to consider more environmental factors in order to better understand factors related to the development of handicap situations.

Coping with the consequences of a stroke.

BACKGROUND AND PURPOSE: Having a stroke constitutes a major life event which engenders some types of adaptation in order to try to resume to a "normal" life. The objectives of this study were (1) to explore the type of coping strategies used following a stroke; (2) to verify if coping strategies change over time, and (3) to verify if the coping strategies used are related to age, gender, actualization of potential, handicap level and depression. METHODS: A convenience sample of 76 participants who had had a stroke was recruited upon discharge from a functional intensive rehabilitation unit. Data were collected 2 weeks later and 6 months later in their own home. Coping strategies were measured using a modified version of the Ways of Coping Questionnaire. Actualization of potential was measured using the Measure of the Actualization of Potential and handicap level was quantified with the LIFE-H. Finally, the Beck Depression Inventory was used to evaluate the presence of depressive symptoms. CONCLUSION: The results suggest that long after the end of an intensive rehabilitation programme, some coping strategies might be more effective in dealing with the consequences of a stroke whereas others might be related to some form of inadaptation. However, the results should be treated with caution. More research on coping following a stroke using mixed methodologies is needed.

Impact of motor, cognitive, and perceptual disorders on ability to perform activities of daily living after stroke.

BACKGROUND AND PURPOSE: Using confirmatory factor analysis, this study evaluates the relative impact of motor, cognitive, and perceptual deficits on functional autonomy with 100 elderly (aged 55 to 79 years) victims of stroke. METHODS: Two different approaches were used for measuring functional autonomy: the Functional Autonomy Measurement System (Système de Mesure de l'Autonomie Fonctionnelle [SMAF]) and the Assessment of Motor and Process Skills (AMPS). RESULTS: The results of the confirmatory factor analysis show that motor, cognitive, and perceptual factors all make a significant contribution to the variation in functional autonomy and confirm the accuracy of the model (93% of the variance is explained when the SMAF is used to measure functional autonomy, and 64% of the variance is explained when the AMPS is used). CONCLUSIONS: The factors that make the greatest contribution in explaining the variance in functional autonomy are, in order of importance, the motor factor, the perceptual factor, and the cognitive factor.

Association between personal and environmental factors and the occurrence of handicap situations following a stroke.

BACKGROUND AND PURPOSE: Little is known about the potential role of environmental factors in the handicap creation process following a stroke. The objective of this study was to explore the presence of a relationship between environmental factors and the occurrence of handicap following a stroke, taking into consideration age and the level of impairments and disabilities. METHODS: This is a cross-sectional study where data were collected 6 months after discharge from an intensive functional rehabilitation unit. A convenience sample of 51 participants was recruited at the time of their admission to the rehabilitation unit for rehabilitation post-stroke. Perceived influence of environmental factors was measured using the Measure of the Quality of the Environment (MQE). Handicap situations were measured with the Assessment of Life Habits (LIFE-H). Impairments and disabilities comprised six domains (cognition, perception. depression, communication, sensorimotor function and comorbidity) assessed using a variety of measuring tools from which a composite score was derived. RESULTS: Fifty-one participants aged 40-97 years old took part in this study. Perceived obstacles in the environment, together with age and the level of impairments and disabilities, explained 58.9% of the variation in the LIFE-H (handicap level). Taken alone, the perceived obstacles (total score) explained 6.2%. The perceived facilitators (total score) in the environment were not found to be related to the presence of handicap situations. CONCLUSION: Increased level of impairments and disabilities. advanced age and perceived barriers in the physical and social environment contribute to the handicap creation process following a stroke.

Attention deficits: is there a right hemisphere specialization for simple reaction time, sustained attention, and phasic alertness?

Impairments of attentional focus often are claimed to be associated with lesions of the right hemisphere. Although some studies comparing right- and left-brain-damaged patients have supported this idea, others have not found differences between these patients in various attention tasks. The present study was carried out in order to further investigate the putative role of the right hemisphere in a simple reaction time task, a sustained attention task, and a phasic alertness task. Subjects were 46 patients with right-hemisphere lesions and 37 patients with left-hemisphere lesions. Results showed no difference between right- and left-brain-damaged patients in simple reaction time, in speed of response over time (sustained attention), and in the capacity to prepare to an uncoming stimulus (phasic alertness). Future studies will have to use a more precise categorization of lesions than only right-versus left-brain damage.

Riboflavin photodegradation and photosensitizing effects are highly dependent on oxygen and ascorbate concentrations.

Riboflavin (RF) is a normal component of the eye lens which triggers a strong photosensitizing activity when exposed to light. Upon irradiation with short wavelength radiations below 400 nm, RF-photosensitized damage may occur. However, vitamin C is present at high concentrations in the normal lens and plays an important role in inhibiting these photosensitization processes. An in vitro simple model was used with the objective of understanding better the relationships between vitamin C and oxygen concentrations on the mechanisms of RF-mediated photodegradation of tryptophan (Trp), a target particularly sensitive to photo-oxidation. Under nitrogen, the RF decomposition reached its maximal value, and vitamin C and Trp photo-oxidation was negligible. When increasing oxygen pressure, RF photodegradation dropped and vitamin C photo-oxidation strongly increased and was maximal at 100% O2. RF-induced photodegradation of Trp first increased with oxygen concentration, up to 40 microM O2, and then decreased. RF and Trp degradation were significantly protected by vitamin C so that no more than 20% of the substrates concentration were oxidized in the presence of vitamin C higher than 0.8 mM. From our results we conclude that in the specific conditions of the normal lens, the high vitamin C concentration (2 mM) is compatible with the UVA radiation hazard, despite the presence of RF. However, if lenticular vitamin C decreases below 0.8 mM, photodegradation of RF may occur and Trp may therefore be photo-oxidized by a Type-I mechanism.

Preoperative screening for von Willebrand disease type 1: low yield and limited ability to predict bleeding.

Type 1 von Willebrand disease (vWd) is the most common hereditary bleeding disorder. The objective of this study was to measure the von Willebrand factor antigen (vWf:Ag) in a large cohort of patients who underwent surgery to assess the role of a new rapid immunoassay in a screening procedure for vWd in preoperative conditions. We studied 832 consecutive patients (540 children, 292 adults) referred to the surgical departments. For each patient we determined the vWf:Ag level with two different assays, an enzyme-linked immunosorbent assay (ELISA)(Asserachrom vWf:Ag; Diagnostica Stago, France) and a rapid immunoassay (Liatest vWf:Ag; Diagnostica Stago). Using the reference test, we found 30 of 832 patients with a vWf:Ag value below the lower limits (21 U/dL to 46 U/dL). The coefficient of correlation between the two tests was 0.77 (P = .001). When receiver operating characteristic curves were used, the cutoff value calculated to detect vWf:Ag defect with the rapid assay was 68.5 U/dL, leading to 0.36% false negatives and 9.7% false positives. Thus the rapid immunoassay appears to be a useful and easy method that is adaptable to urgent situations. Among the 30 patients with low values in ELISA, 8 had personal or familial bleeding history. Repeat blood samples confirmed the diagnosis of vWd in 5 cases, leading to a prevalence of vWd type 1 of 0.6%. However, in our series the absence of severe bleeding complications raises the question of the screening and the management of patients bearing a type 1 Willebrand disease during surgery.

[Anaphylactic shock after a test-dose of aprotinin in pediatric orthopedic surgery]. / Choc anaphylactique après dose-test d'aprotinine en chirurgie orthopédique pédiatrique.

A case of severe anaphylactic shock in a 28-month-old child following a testing-dose of aprotinin during major orthopaedic surgery is reported. Two months earlier, aprotinin had been administered during a similar controlateral surgical procedure. The grade III anaphylactic accident required a 48 h treatment in an intensive care unit. The outcome was favourable. The pin-prick tests were positive for aprotinin, substantiating the diagnosis of anaphylactic shock, whereas the test with specific IgE was negative. The value of current diagnostic tools for aprotinin allergy is discussed. The administration of a testing-dose in a patient previously treated with aprotinin cannot be recommended. Considering the risk for allergy, aprotinin should only be administered for recognized indications such as major orthopaedic surgery. Before any readministration of this agent an assessment by an allergist-anaesthetist is essential for determination of the risk-benefit ratio.

Age-related changes in upper extremity performance of elderly people: a longitudinal study.

The objective of this research was to study age-related changes in the upper extremity performance of healthy community-dwelling elderly people, by using a longitudinal design. In 1995-1996. gross and fine manual dexterity, global performance, motor coordination, grip strength, tactile recognition, two-point discrimination, touch/pressure threshold, and tactile localization of 264 of the 360 subjects initially evaluated in 1992-1993 were reevaluated by using the same upper extremity measuring instruments. Those who did not participate (n = 96) were found to be significantly different from those who participated in the longitudinal study. Although the survivors were younger, more active, and perceived themselves in better health than the nonparticipants, their upper extremity performance significantly decreased in the 3-year period, with a few exceptions. In general, the decline was related to the initial score but not to age.