Pharmacokinetic interaction between rifampicin and clindamycin in staphylococcal osteoarticular infections.

OBJECTIVES: Oral combination of clindamycin and rifampicin is relevant for the treatment of staphylococcal osteoarticular infection (SOAIs). However, rifampicin induces CYP3A4, suggesting a pharmacokinetic interaction with clindamycin with unknown pharmacokinetic/pharmacodynamic (PK/PD) consequences. This study aimed to quantify clindamycin PK/PD markers before and during rifampicin co-administration in SOAI. METHODS: Patients with SOAI were included. After initial intravenous antistaphylococcal treatment, oral therapy was started with clindamycin (600 or 750 mg t.i.d.), followed by addition of rifampicin 36 h later. Population PK analysis was performed using the SAEM algorithm. PK/PD markers were compared with and without rifampicin co-administration, each patient being his own control. RESULTS: In 19 patients, clindamycin median (range) trough concentrations were 2.7 (0.3-8.9) mg/L and <0.05 (<0.05-0.3) mg/L before and during rifampicin administration, respectively. Rifampicin co-administration increased clindamycin clearance by a factor 16 and reduced the AUC0-8h/MIC by a factor 15 (P < 0.005). Clindamycin plasma concentrations were simulated for 1000 individuals, without and with rifampicin. Against a susceptible Staphylococcus aureus strain (clindamycin MIC 0.0625 mg/L), >80% of individuals would reach all proposed PK/PD targets without co-administration of rifampicin, even with low clindamycin dose. For the same strain, when rifampicin was co-administered, the probability to reach clindamycin PK/PD targets dropped to 1% for %fT>MIC = 100% and to 6% for AUC0-24h/MIC > 60, even with high clindamycin dose. CONCLUSION: Rifampicin co-administration with clindamycin has a high impact on clindamycin exposure and PK/PD targets in SOAI, which could result in clinical failure even for fully susceptible strains.

[Compliance as a prognostic factor in the treatment of idiopathic scoliosis]. / Die Compliance als Prognosefaktor bei der konservativen Behandlung idiopathischer Skoliosen.

BACKGROUND: The purpose of this study was to assess the compliance of brace treatment and the correlation with outcomes in patients with idiopathic scoliosis. METHODS: Ninety adolescent patients completed treatment with the Dresden scoliosis orthosis. After a mean follow-up time of 4.3 years, their level of compliance was retrospectively assessed and correlated with the radiographic results. RESULTS: The amount of primary correction was 36% in the lumbar spine and 25% in the thoracic spine. Of the patients, 59.4% were compliant (daily duration of brace treatment >20 h). The success rate in this group (improved or constant Cobb angles during therapy) was 89%. With good compliance and primary correction of more than 30%, the average Cobb angle at follow-up had improved by 8.3 degrees in the thoracic spine and by 12.4 degrees in the lumbar spine compared with the initial Cobb angle. Eleven of 39 patients in the noncompliant group but only four of 57 compliant patients underwent surgery. CONCLUSION: Compliance with orthosis therapy and the amount of primary correction are together the most important factors for predicting the final outcome of brace treatment in idiopathic scoliosis. Influencing factors on compliance must be further analyzed.

[Is night-time bracing still appropriate in the treatment of idiopathic scoliosis?]. / Hat die Nachtorthese in der Skoliosetherapie noch eine Berechtigung?

BACKGROUND: The aim of our investigation was to evaluate the effectiveness of isolated night-time treatment in idiopathic scoliosis. METHODS: Twenty-two children (average age 11.9 years; range 5-12 years) underwent treatment with the "Dresdner night-time brace." We indicated brace treatment in all children with a Cobb angle of 20-25 degrees and also in those with an angle of 15-19 degrees in cases of progression. Over a follow-up period of 25 months, clinical and radiological observations were made. RESULTS: A primary correction of 82.2% was obtained. The mean Cobb angle in an upright position without orthosis before treatment was 20.2 degrees. At the end of treatment, this angle reached 15.8 degrees. Operations were able to be avoided completely. In only three cases with radiographic progression (development of angles >25 degrees), part-time bracing had to be stopped and changed to full-time bracing. We observed an overall success rate of 86.4% (patients with improved Cobb angles or halted progression). CONCLUSION: We were able to show a positive effect of part-time bracing in selected patients with mild scoliosis and a higher risk of progression. The negative medical and psychosocial consequences of 23-h brace treatment can therefore be avoided in certain patients.

Interaction of nitrogen nutrition and salinity in Grey poplar (Populus tremula x alba).

Salinity represents an increasing environmental problem in managed ecosystems. Populus spp. is widely used for wood production by short-rotation forestry in fertilized plantations and can be grown on saline soil. Because N fertilization plays an important role in salt tolerance, we analysed Grey poplar (Populus tremula x alba, syn. Populus canescens) grown with either 1 mM nitrate or ammonium subjected to moderate 75 mM NaCl. The impact of N nutrition on amelioration of salt tolerance was analysed on different levels of N metabolism such as N uptake, assimilation and N (total N, proteins and amino compounds) accumulation. Na concentration increased in all tissues over time of salt exposure. The N nutrition-dependent effects of salt exposure were more intensive in roots than in leaves. Application of salt reduced root increment as well as stem height increase and, at the same time, increased the concentration of total amino compounds more intensively in roots of ammonium-fed plants. In leaves, salt treatment increased concentrations of total N more intensively in nitrate-fed plants and concentrations of amino compounds independently of N nutrition. The major changes in N metabolism of Grey poplar exposed to moderate salt concentrations were detected in the significant increase of amino acid concentrations. The present results indicate that N metabolism of Grey poplar exposed to salt performed better when the plants were fed with nitrate instead of ammonium as sole N source. Therefore, nitrate fertilization of poplar plantations grown on saline soil should be preferred.

Glucagon kinetics in growing rats fed different levels of protein and/or energy.

The present work was carried out to evaluate the kinetic parameters of glucagon in growing rats divided into three groups: T, H and E. Group T (Control group) was fed a control diet (crude protein: 11.8%). Groups H and E received a high protein diet (crude protein: 19%) distributed in either equal (Group H) or restricted amounts (Group E) with respect to the control. Thus, the main characteristic of Group H was the high level of protein intake (+ 68%) when Group E rats underwent a moderate increase in protein intake but a striking caloric deprivation (-25%). In all cases, the animals were fed a meal every 4 hours. The kinetic parameters of glucagon metabolism were estimated from the plasma disappearance curves of 125I-glucagon for five minutes following a pulse injection of purified 125I-glucagon (1 muCi, about 3.8 ng/100 g BW). Plasma 125I-glucagon was measured after gel filtration of plasma on Biogel P-10. Tissue radioactivity (mainly liver and kidneys) was recorded seven minutes after 125I-glucagon injection. The results showed that the plasma 125I-glucagon level was higher in Group H than in the other groups 1 min after the injection. At all other times (2, 3.5 and 5 min) it was similar in all groups. 125I-glucagon was rapidly cleared from plasma and rapidly taken up by the liver and kidneys. In the 3 experimental groups, mean half-life and metabolic clearance rate were estimated to be 2 min and 6 ml/min/100 g BW, respectively. Excess protein intake resulted in a reduction in the apparent initial distribution volume of 125I-glucagon without modifying significantly its turn-over rate and metabolic clearance rate. Kidneys and liver (6% BW) accounted for about 20% of the 125I-glucagon uptake by tissues 7 min after injection. Group H kidneys and liver were more labelled than in other groups. These results suggest that increased protein intake (without further caloric deprivation) can induce some changes in glucagon metabolism which could partially contribute to the increase in glucagonemia usually observed in animals fed high protein diets.

[Injuries to the facial portion of the skull and their late effects in children and juveniles - a 10-year analysis (author's transl)]. / Die Gesichtsschädelverletzungen und ihre Spätfolgen bei Kindern und Jugendlichen - eine 10-Jahres-Analyse.

A 10-year analysis comprising a total of 534 patients was used to study the histories of 192 puerile and juvenile patients with maxillofacial injuries. The proportion of children up to ten and fifteen years of age was 11.4 percent and 16.1 percent, respectively. Clinical and roentgenological reexaminations could be made of 139 patients. Typical fracture localizations and the frequency of late effects observed in the facial skeleton and dental system are discussed. It was possible for late damage to former tooth germs in the cleft of fracture to be observed in every second patient. Disturbances of growth after fractures of the body of mandible and the mid-facial skeleton were not noted. Among 33 patients with temporomandibular fractures, there were observed 5 cases showing different degrees of disturbed growth. The therapeutic approach chosen according to age and localization of fracture is described in detail.

[Effects of technological processing on digestive and metabolic utilization of amino acids from various protein foods]. / Effets des traitements technologiques sur l'utilisation digestive et métabolique des acides aminés de quelques aliments protéiques.

The use of vegetable proteins such as legumes or oilseeds proteins is often restricted by antinutritional or toxic factors. Therefore, it is usefull, in order to extend their consumption, to isolate proteins from most of the other components of the seeds. Unfortunately, the technological processes may have some deleterious effects on the nutritive value of the proteins. Moreover, the proteins isolates and concentrates need further processing to be texturated in order to look like conventional foods for humans. We used growing rats to study the effect of some of these technological processes on the nutritive value of some field bean and sunflower protein feedstuffs. We estimated the digestive utilization of dry matter, nitrogen and amino acids, and the amino acid composition of feces was used in trying to explain some decreases in nitrogen digestibility. We also studied the ability of their amino acids to be used for growth, and tried to estimate their availability from blood and muscle free amino acids determinations. It may be inferred from the results that the technologists were successfull in improving their processes, and that textured field beans and sunflower proteins of good nutritional quality may be processed now.