[Cervical collars: a clinical and biomechanical study]. / Zervikalstützen: Eine klinische und biomechanische Studie.

AIM: Cervical collars have been used for years in the non-operative and postoperative management of cervical spine problems. They offer considerable differences in design, stability, bearing comfort and costs. In the background of controversies about the indication and in view of the limited number of scientific publications on the topic we have conceived this paper as a biomechanical and clinical investigation. METHODS: During the biomechanical investigations a defined load was exerted on 10 cervical collars of 4 producers. The clinical part was the measurement of the limitation of movement due to the 10 cervical collars in 30 healthy subjects aged 20 to 60 years. RESULTS: The biomechanical investigations showed differences of stiffness which were obvious during axial load, sideward and backward bending and less obvious in forward bending. The clinical study in 30 subjects indicated, on the other hand, only small differences in the limitation of movement. Softer cervical collars were slightly better accepted in the subjective judgment. CONCLUSION: For the aimed limitation of movement, a minimum of stiffness is obviously necessary, which is common with every tested collar. Higher degrees of stiffness do not result in further limitation of movement but only in a reduction of bearing comfort.

[Safety and efficacy of LK565--a new polymer ultrasound contrast medium]. / Untersuchungen zur Sicherheit und Effizienz von LK565--einem neuen Polymer-Ultraschallkontrastmittel.

We tested a newly developed ultrasound contrast agent (LK565) from poly-aspartic acid (PAA; particle size 3 microns; particle content: air) in 15 healthy male probands (20-38 years) in doses of 10, 30 and 100 mg intravenously. One day and immediately before the study a routine laboratory test, an ECG and an EEG were performed. The EEG was continued through the complete time period that the ultrasound contrast lasted, i.e., up to one hour after the injection. All probands were followed clinically for 24 hours when the routine laboratory and the ECG were repeated. All subjects tolerated the contrast agent well. There were no changes in either the EEG or in the ECGs performed throughout the study. There were no significant laboratory changes except for a small and transient increase in the neutrophil count in five probands receiving the highest dose. All injections with 10 mg led to a significant improvement in the color Doppler signal. All injections with 30 and 100 mg led to a very strong echo contrast lasting for 5 to 12 minutes in the harmonic B-mode. Using the latter, fragments of intramyocardial coronaries could be visualized. The tested ultrasound polymer contrast agent was safe, well tolerated and efficient in this acute study.

Lower limb injuries in children in sports.

This article presents an overview of sports-related injuries of the lower limb in children, with emphasis on the management. The special injury-related conditions of childhood, epidemiology, and the particular pattern of injuries are discussed. The increased participation of children in sports will continue. Permanent damage is a risk, and, as such, prevention should be the most important management in this age group. For example, stretching exercises should be performed with "warm" muscles. Excessive weight training has an unacceptable risk of injury. In endurance sports, the "10 percent rule," which consists of increasing activity by 10% each week, probably could be applied to prevent overuse injuries. A multifactorial approach may be helpful. The rationale for high performance, competitive sports for children is doubtful. The optimal levels of safe training will remain changeable and not predictable. It should be the responsibility of parents, coaches, and healthcare professionals to try and minimize the potential for injury and disability, and allow children to enjoy the benefits of sports.

Injuries in young athletes.

UNLABELLED: Most injuries in children's sports are minor and self-limiting, suggesting that children and youth sports are safe. A child's skeletal system shows pronounced adaptive changes to intensive sports training. Sports injuries affect both growing bone and soft tissues and could result in damage of the growth mechanisms with subsequent life-lasting damage. During growth there are significant changes in the biomechanical properties of bone. In young athletes, as bone stiffness increases and resistance to impact diminishes, sudden overload may cause bones to bow or buckle. Epiphyseal injuries are usually due to shearing and avulsion forces, although compression also plays a significant role. Given the remarkable healing potential of bone in youngsters, fractures that initially united with some deformity can completely remodel and appear totally normal in later life. CONCLUSION: As the risk of injuries sustained by young athletes can be significant, it is essential that training programmes take into account their physical and psychological immaturity, so that growing athletes can adjust to their own body changes.

Regulation of beta-lactamase synthesis as a novel site of action for suppression of methicillin resistance in Staphylococcus aureus.

Nearly all clinical isolates of methicillin resistant Staphylococcus aureus (MRSA) produce beta-lactamase as well as an additional low-affinity penicillin-binding protein called PBP2a or PBP2', the main factor for mediating methicillin resistance. Polidocanol (PDO), a dodecyl polyethyleneoxide ether, resensitizes clinical isolates of MRSA to methicillin; in addition, their resistance to benzylpenicillin (BP) is reduced. The action of PDO is based on the inhibition of the induced syntheses of PBP2a and beta-lactamase. Induction in our study was performed with 2-(2'-carboxyphenyl)benzoyl-6-aminopenicillanic acid (CBAP). Inducible PBP2a production in MRSA strains is under the control of the same regulatory system which is responsible for the induction of beta-lactamase synthesis. BlaR1, a membrane-spanning protein with a penicillin sensor and a signal transducer domain represents the starting point of this induction cascade. Based on its amphiphilic properties, it is likely that the action of PDO is located in the bacterial membrane. Therefore we investigated the possibility that BlaR1 might be the main target for PDO action. We were able to detect the BlaR1 sensor domain in resistant staphylococcal cells even in the noninduced state by fluorography. In a competition assay, CBAP was bound specifically, with a high affinity to the penicillin sensor. Moreover, the binding of CBAP was very stable. As concerns PDO, no significant interaction with the penicillin binding site of BlaR1 was detectable. This is why the BlaR1 transducer domain is thought to be the actual target area of PDO. In this case, PDO would interfere with the transmission of the signal, generated by the receptor binding of CBAP, through the membrane via BlaR1 into the staphylococcal cell. This assumption could be confirmed by the analysis of the concentration-effect relationship, whereafter PDO does not work as a competitive, but as a noncompetitive antagonist of CBAP. Our results demonstrate that BlaR1 could be an attractive new target for the development of new drugs to overcome methicillin resistance.

Nutritional benefits of neonatal screening for cystic fibrosis. Wisconsin Cystic Fibrosis Neonatal Screening Study Group.

BACKGROUND: Many patients with cystic fibrosis are malnourished at the time of diagnosis. Whether newborn screening and early treatment may prevent the development of a nutritional deficiency is not known. METHODS: We compared the nutritional status of patients with cystic fibrosis identified by neonatal screening or by standard diagnostic methods. A total of 650,341 newborn infants were screened by measuring immunoreactive trypsinogen on dried blood spots (from April 1985 through June 1991) or by combining the trypsinogen test with DNA analysis (from July 1991 through June 1994). Of 325,171 infants assigned to an early-diagnosis group, cystic fibrosis was diagnosed in 74 infants, including 5 with negative screening tests. Excluding infants with meconium ileus, we evaluated nutritional status for up to 10 years by anthropometric and biochemical methods in 56 of the infants who received an early diagnosis and in 40 of the infants in whom the diagnosis was made by standard methods (the control group). Pancreatic insufficiency was managed with nutritional interventions that included high-calorie diets, pancreatic-enzyme therapy, and fat-soluble vitamin supplements. RESULTS: The diagnosis of cystic fibrosis was confirmed by a positive sweat test at a younger age in the early-diagnosis group than in the control group (mean age, 12 vs. 72 weeks). At the time of diagnosis, the early-diagnosis group had significantly higher height and weight percentiles and a higher head-circumference percentile (52nd, vs. 32nd in the control group; P=0.003). The early-diagnosis group also had significantly higher anthropometric indexes during the follow-up period, especially the children with pancreatic insufficiency and those who were homozygous for the deltaF508 mutation. CONCLUSIONS: Neonatal screening provides the opportunity to prevent malnutrition in infants with cystic fibrosis.