Preliminary findings on biomarker levels from extracerebral sources in patients undergoing trauma surgery: Potential implications for TBI outcome studies.

BACKGROUND: Despite several experimental studies on the role of S100B and NSE in fractures, no studies on the influence of surgery on the biomarker serum levels have been performed yet. METHODS: The serum levels of S100B and NSE were analysed in patients with fractures that were located in the spine (group 1, n = 35) or in the lower extremity (group 2, n = 32) pre- and post-operatively. RESULTS: The mean S100B serum level showed a significant increase (p = 0.04) post-surgery in the patients of group 1. In patients undergoing acute surgery (< 24 hours) the mean S100B serum level was 0.23 ± 0.22 µg L(-1) pre-operatively and 1.24 ± 1.38 µg L(-1) post-operatively. Likewise, the mean S100B serum level significantly increased in group 2 after surgery (p < 0.0001). In this group patients undergoing acute surgery showed a mean S100B serum level of 0.23 ± 0.14 µg L(-1) and 1.11 ± 0.73 µg L(-1) pre- and post-operatively. CONCLUSION: This study demonstrates significant alterations of the biomarker S100B serum levels in patients undergoing surgery. Higher S100B serum levels were found within 24 hours and might be related to the acute fracture. The NSE serum levels were unchanged and this biomarker may offer the probability to serve as a future outcome predictor in studies with patients with traumatic brain injury and additional extracerebral injuries.

Fibrinogen but not factor XIII deficiency is associated with bleeding after craniotomy.

BACKGROUND: Postoperative haemorrhage in neurosurgery is associated with significant morbidity and mortality. There is controversy whether or not factor XIII (FXIII) deficiency leads to bleeding complications after craniotomy. Decreased fibrinogen levels have been associated with an increased incidence of bleeding complications in cardiac and orthopaedic surgery. The aim of this study was to assess perioperative fibrinogen and FXIII levels in patients undergoing elective intracranial surgery with and without severe bleeding events. METHODS: Perioperative FXIII and fibrinogen levels were prospectively assessed in 290 patients undergoing elective craniotomy. Patients were divided into two groups according to the presence or absence of severe bleeding requiring surgical revision. Coagulation test results of these groups were compared using Student's t-test. RESULTS: The incidence of postoperative severe bleeding was 2.4%. No differences in FXIII levels were observed, but postoperative fibrinogen levels were significantly lower in patients suffering from postoperative haematoma compared with those without postoperative intracranial bleeding complications [237 mg dl(-1) (standard deviation, SD 86) vs 170 mg dl(-1) (SD 35), P=0.03]. The odds ratio for postoperative haematoma in patients with a postoperative fibrinogen level below 200 mg dl(-1) was 10.02 (confidence interval: 1.19-84.40, P=0.03). CONCLUSIONS: This study emphasizes the role of fibrinogen as potentially modifiable risk factor for perioperative bleeding in intracranial surgery. Future randomized controlled trials will be essential to identify patients who might benefit from fibrinogen substitution during neurosurgical procedures.

Marked decrease of LSD-induced stimulus control in serotonin transporter knockout mice.

RATIONALE: Based upon extensive studies in the rat, it has been suggested that stimulus control by LSD is mediated by 5-HT2A receptors, with serotonergic receptors of the 5-HT1A and 5-HT2C subtypes playing modulatory roles. In genetically modified mice lacking the serotonin transporter (SERT), 5-HT2A receptor density is decreased and, at a functional level, the head-twitch response following the administration of DOI, an index of activation of 5-HT2A receptors, is reduced. Taken together, these studies led us to hypothesize that the efficacy of LSD in establishing stimulus control is diminished or abolished in mice lacking the serotonin transporter. OBJECTIVE: Determine the efficacy of LSD for establishing stimulus control in SERT knockout (KO) mice. METHODS: SERT KO mice and wildtype (WT) littermates were trained in a visual discrimination on a progressive fixed ratio (FR) water-reinforced task and subsequently trained on a FR10 schedule with LSD (0.17 or 0.30 mg/kg) or vehicle. To control for general deficiencies in drug discrimination, mice were trained with pentobarbital (15 or 30 mg/kg) or vehicle. RESULTS: The visual stimulus exerted control in both genotypes. LSD-induced stimulus control in 90% of WT mice but only 31% of SERT KO mice. In contrast, pentobarbital-induced stimulus control in 80% of WT mice and 54% of knockout mice. CONCLUSIONS: Although SERT KO mice exhibited stimulus control by the non-serotonergic drug, pentobarbital, the efficacy of LSD in these animals was markedly decreased, suggesting that reduced density of 5-HT1A and/or 5-HT2A receptors underlies the absence of stimulus control by LSD.

[Biodegradable cage. Osteointegration in spondylodesis of the sheep cervical spine]. / Biodegradierbarer Cage. Osteointegration bei Spondylodese der Schafhalswirbelsäule.

Bioabsorbable implants are commonplace in knee and shoulder surgery. Bioabsorbable poly(l-lactide-co-D,L-lactide) (PLDLLA) cage devices have potential benefits over autologous tricortical iliac crest bone graft and metallic cages for cervical spine interbody fusion. The purpose of this study was to compare interbody fusion of an autologous tricortical iliac crest bone graft with that of a bioabsorbable cage using a sheep cervical spine interbody fusion model. This study was designed to determine differences in (1) the ability to preserve postoperative distraction, (2) biomechanical stability, and (3) histological characteristics of intervertebral bone matrix formation. Sixteen full-grown Merino sheep underwent C3/4 discectomy and fusion. After 12 weeks, there was no significant difference between the results with the bioabsorbable PLDLLA cages and tricortical bone grafts. The cage also did not show advanced interbody fusion but did, however, show large osteolysis, which allows skepticism regarding the value of this bioabsorbable implant.

Effects of acute and repeated methamphetamine treatment on the ultrasonic vocalizations of postnatal rats.

Repeated exposure to cocaine (COC) has been reported to both increase ultrasonic vocalizations (USVs) of postnatal rats and enhance the crying of human infants. The purpose of the present study was to determine whether acute or repeated treatment with another commonly abused psychostimulant, methamphetamine (MAP), would affect the USV production of postnatal rats. In the first experiment, USVs were measured 30 min after rats were given an acute injection of saline or MAP (1, 2, 4, or 8 mg/kg ip) on postnatal day (PD) 10. In the second experiment, rats were exposed to MAP (0, 1, or 4 mg/kg/day ip) on PD 2-8 or PD 2-9. On PD 10, rats were given an acute injection of saline or MAP (1 or 4 mg/kg ip) 30 min prior to behavioral assessment. Results showed that acute treatment with MAP (4 or 8 mg/kg) decreased the USVs of rats on PD 10, while repeated exposure to MAP did not affect the USV emissions of rats subsequently treated with saline or MAP. The reason why acute MAP treatment decreased USV production is uncertain, but it is possible that MAP alleviates isolation distress by stimulating reward processes. Alternatively, MAP increases heart rate and blood pressure, so acute treatment with this drug may decrease USV emissions through peripheral physiological mechanisms (i.e., by reducing abdominal compression reactions).

Ultrasonic vocalizations of preweanling rats: involvement of both alpha(2)-adrenoceptor and kappa-opioid receptor systems.

Stimulation of alpha(2)-adrenoceptors and kappa-opioid receptors increases the ultrasonic vocalizations of preweanling rats. The purpose of the present study was to determine whether alpha(2)-adrenoceptors and kappa-opioid receptors modulate ultrasonic vocalization production via a common mechanism. To that end, 11-day-old rats were injected with the alpha(2)-adrenoceptor antagonist yohimbine (0, 0.5, or 1.0 mg/kg, i.p.) or the kappa-opioid receptor antagonist nor-binaltorphimine (0, 5, or 10 mg/kg, i.p.). After 15 min, the same rats were injected with saline, the alpha(2)-adrenoceptor agonist clonidine (0.25 mg/kg, i.p.), or the kappa-opioid receptor agonist trans-(+/-)-3,4-dichloro-N-methyl-N-[2-(1-pyrrolidinyl)-cyclohexyl]-benzeneacetamide methanesulfonate (U-50,488; 2.5 mg/kg, i.p.). Results showed that both clonidine and U-50,488 increased the ultrasonic vocalizations of preweanling rats. Not surprisingly, clonidine-induced ultrasonic vocalizations were blocked by yohimbine, while U-50,488-induced vocalizations were blocked by nor-binaltorphimine. Importantly, yohimbine also attenuated the vocalizations produced by U-50,488, whereas nor-binaltorphimine did not alter clonidine-induced ultrasonic vocalizations. Thus, it appears that alpha(2)-adrenoceptor and kappa-opioid receptor stimulation increases ultrasonic vocalization production via a common mechanism. It is likely that the kappa-opioid receptors responsible for modulating ultrasonic vocalizations are located "upstream" from the alpha(2)-adrenoceptors.

Separation of botulinum-positive and -negative fish samples by means of a pattern recognition method applied to headspace gas chromatograms.

A gas chromatographic headspace technique was used to analyze the gas produced during putrefaction of pond-raised, degutted trout, incubated in evacuated plastic pouches. The following samples were analyzed; 10 samples which, due to natural contamination with Clostridium botulinum, were toxic when injected into mice, 10 samples which were nontoxic when injected, and 9 samples inoculated with one strain of C. botulinum type E. The gas chromatograms showed the presence of 118 compounds in most samples. Quantitative differences among most chromatograms could be observed, but no compound was unique to any of the three groups. By means of a specific pattern recognition method, all negative samples were shown to fall into one group and were distinctly separated from the toxic samples. No differences could be observed between the two groups of inoculated and naturally contaminated trout samples. The results suggest that headspace analysis combined with pattern recognition analysis might prove to be a valuable method for screening studies of foods containing living cells of C. botulinum.