Echo-enhanced transcranial color-coded US: clinical usefulness of intravenous infusion versus bolus injection of SH U 508A.

Twelve patients with insufficient transcranial Doppler signal underwent transcranial color-coded ultrasonography before and after administration of SH U 508A with different modes of administration. Clinically useful enhancement time after bolus injection was surpassed by that after standard infusion (1 mL/min), whereas further prolongation was observed after individualized infusion. Intravenous infusion of SH U 508A provides a prolonged useful enhancement compared with that after bolus injection.

Tolerance-Inducing dose of 3-nitropropionic acid modulates bcl-2 and bax balance in the rat brain: a potential mechanism of chemical preconditioning.

Many studies have reported ischemia protection using various preconditioning techniques, including single dose 3-nitropropionic acid (3-NPA), a mitochondrial toxin. However, the cellular signal transduction cascades resulting in ischemic tolerance and the mechanisms involved in neuronal survival in the tolerant state still remain unclear. The current study investigated the mRNA and protein expression of the antiapoptotic bcl-2 and the proapoptotic bax. two antagonistic members of the bcl-2 gene family, in response to a single dose of 3-NPA, to global cerebral ischemia-reperfusion. and to the combination of both 3-NPA-pretreatment and subsequent global cerebral ischemia-reperfusion. Brain homogenates of adult Wistar rats (n = 25) were analyzed for bcl-2 and bax mRNA expression using a new highly sensitive and quantitative polymerase chain reaction (PCR) technique that allows real-time fluorescence measurements of the PCR product (LightCycler; Roche Diagnostics, Mannheim, Germany). Animals for mRNA analysis received 3-NPA (20 mg/kg, intraperitoneal; "chemical preconditioning") or vehicle (normal saline), and were either observed for 24 plus 3 hours or were subjected to 15 minutes of global cerebral ischemia 24 hours after the pretreatment and observed for 3 hours of reperfusion. Immunohistochemistry was applied to serial brain sections of additional rats (n = 68) to determine amount and localization of the respective Bcl-2 and Bax protein expression in various brain areas. One set of animals was injected with 3-NPA and observed for 3, 12, 24, and 96 hours; a second set was exposed to 15 minutes global cerebral ischemia, 3, 12, and 24 hours reperfusion; and a third set was pretreated with 3-NPA or saline 24 hours before the ischemic brain insult and observed for 96 hours of reperfusion. The authors found single dose 3-NPA treatment to be associated with an elevated bcl-2:bax ratio (increased bcl-2 expression, decreased bax expression), both on the transcriptional (mRNA) and the translational (protein) level. The differential influence of 3-NPA was maintained during early recovery from global cerebral ischemia (3 hours), when 3-NPA pretreated animals showed higher bcl-2 and lower bax mRNA levels compared with rats with saline treatment. Respective changes in protein expression were localized predominately in neurons vulnerable to ischemic damage. Compared with baseline, Bcl-2 protein was significantly higher in surviving neurons at 96 hours after the insult, whereas Bax protein remained unchanged. However, at this late time of postischemic recovery (96 hours), the protein expression pattern of surviving neurons was not different between animals with and without 3-NPA pretreatment. To the authors' knowledge, the current study is the first report on the differential expression of pro- and antiapoptotic genes after a single, nonlethal dose of 3-NPA. The current results suggest alterations in the balance between pro- and antiapoptotic proteins as a potential explanation for the reported protection provided by chemical preconditioning using 3-NPA in rats.

Role of climate, crown position, tree age and altitude in calculated ozone flux into needles of Picea abies and Pinus cembra: a synthesis.

Ozone (O(3)) flux into Norway spruce (Picea abies) and cembran pine (Pinus cembra) needles was estimated under ambient conditions at six rural sites between 580 and 1950 m a.s.l. We also assessed age-related differences in O(3) flux by examining changes in leaf conductance across the life span of Norway spruce. At the leaf level O(3) flux into the needles was effectively controlled by stomatal conductance and, hence by factors such as temperature, irradiance and humidity, which control stomatal conductance. Seasonal variations in O(3) flux were mainly attributed to the course of the prevailing temperature. During the growing season, however, data have emphasised leaf-air vapour pressure difference as the environmental factor most likely to control stomatal conductance and O(3) flux into the needles. In the sun crown stomatal conductance averaged over the growing season decreased with increasing tree age from 42.0+/-3.5 mmol O(3) m(-2) s(-1) in 17-year-old trees to 7.1+/-1.0 mmol O(3) m(-2) s(-1) in 216-year-old trees, indicating that O(3) concentration in the substomatal cavities is higher in young than in old trees. Independent from tree age stomatal conductance and O(3) flux were approximately 50% lower in shade needles as compared to sun-exposed needles. Stomatal conductance was also greater in the current flush (24+/-5.6 mmol O(3) m(-2) s(-1)) and in 1-year old needles (16+/-4 mmol O(3) m(-2) s(-1)) than in older needle age classes (12+/-1 mmol O(3) m(-2) s(-1), averaged across the four older needle age classes). In trees similar in age (60-65 years old) average O(3) flux into sun needles increased from 0.55+/-0.36 nmol m(-2) s(-1) at the valley floor to 0.9 nmol m(-2) s(-1) in 1950 m a.s.l. Cumulative O(3) uptake during the vegetation period increased from 11.4+/-1.7 mol m(-2) in the valley to 14 mol m(-2) at the alpine timberline. Although stomatal conductance provides the principal limiting factor for O(3) flux, additional field research is necessary in order to improve our understanding concerning the quantitative 'physiological threshold dose' which internally can be active and can have adverse effects of O(3) on forest trees.

Performance of transcription-mediated amplification and ligase chain reaction assays for detection of chlamydial infection in urogenital samples obtained by invasive and noninvasive methods.

Based on the amplification of chlamydia-specific rRNA sequences and the ligase chain reaction (LCR), the performance characteristics of the Gen-Probe Chlamydia trachomatis transcription-mediated amplification (TMA) assay were evaluated with endocervical, urine, and vulval specimens from women and urethral and urine specimens from men and were compared with those for cultures on endocervical, vulval, and urethral swabs. Of the 308 women and 240 men tested, 25 (8.1%) and 44 (18.3%), respectively, were shown to be infected. By using the infected individual as the expanded "gold standard" for calculations, the TMA assay and LCR gave similar performances for the sensitivity of male urethral (93.2%) and urine (88.6 and 86.4%) samples, while culture detected only half of the 44 infected men. In women, the sensitivities of the TMA assay for endocervical and vulval samples were 88 and 92%, respectively, compared to values of 92% for the LCR on both sample types and of 52 and 8%, respectively, for culture. By using first-void urine for chlamydial diagnosis in women, LCR detected 24 (96%) and TMA assay detected 19 (76%) infected individuals, showing a significantly lower sensitivity for urine in women (P = 0.0253). The results indicate a high overall agreement for both amplifying techniques for all examined specimen types, except for female urine. Furthermore, they confirm the previous observation that vulval swabs are an effective alternative noninvasive sample type for the detection of C. trachomatis infection in women by nucleic acid-based amplification technologies.

[Results of autologous blood donation in orthopedic hip and knee joint replacement]. / Ergebnisse der Eigenblutspende bei orthopädischem Hüft- und Kniegelenkersatz.

OBJECTIVE: This study was undertaken to investigate the efficiency of autologous blood donation (ABD) with regard to saving of homologous transfusion, to determine the reasons for exclusion from donations and the rate of incidents during the procedure, and to investigate the quality of autologous fresh frozen plasma (AFFP). METHODS: During an observation period of 4.5 years, all patients scheduled for elective orthopaedic hip and knee replacement were included. A period of 4 years was evaluated retrospectively, and the last half year was evaluated prospectively. RESULTS: Among a collective of 710 patients, 55 (8%) non-donors and 655 (92%) donors with a total number of 1592 ABD were found. Mean age of non-donors with hip surgery was significantly higher than that of donors (72 vs. 64 years), the same was observed in patients with knee surgery (71 vs. 68 years). In the hip surgery group, 11 of 338 patients were non-donors (3%), compared with 44 of 372 patients with knee surgery (12%). In the prospective part of the study, 7% of 121 patients were non-donors. Reasons for exclusion from donation were 5 times of medical and 4 times of organisational nature. In donors for hip surgery, a mean of 3.0 units was collected, compared with 1.9 units in donors for knee surgery. On the day before operation, mean haemoglobin concentrations were similar in donors and non-donors. During ABD, 11 incidents were observed, representing 0.69% of all ABD, 83.5% of 327 donors with hip surgery left the hospital without any transfusion of homologous blood, 16.5 of donors with hip surgery received one or more homologous transfusions, compared with 100% of non-donors (p < 0.001). In knee surgery, 93.3% of donors and 63.6% of non-donors required no homologous blood, whereas 6.7% of donors and 36.4% of non-donors received one or more homologous transfusions (p < 0.001). 529 of 2850 autologous blood units (19%) were not transfused, and 19 of these units were rejected due to technical or organisational problems. In 97 patients with 240 ABD and 240 AFFP, prothrombine time, fibrinogen concentration and AT III in defrosted AFFP exceeded 70% of the values determined before ABD. CONCLUSION: ABD is a safe procedure in almost all, even elderly, patients scheduled for elective orthopaedic hip or knee replacement in both types of operations, ABD reduces the risk of homologous transfusion significantly. A number of 3-4 units is necessary for total hip replacement, whereas 2 units are sufficient for partial or total knee replacement. Haemostatic quality of AFFP meets the requirements of fresh frozen homologous plasma.

Glial cell interactions with tenascin-C: adhesion and repulsion to different tenascin-C domains is cell type related.

The multimodular glycoprotein tenascin-C is transiently expressed, predominantly by glial cells, during the development of the central and peripheral nervous systems. This extracellular matrix glycoprotein is involved in the control of cell adhesion, neuron migration and neurite outgrowth. Distinct functional properties for neuronal cell types have been attributed to separate tenascin-C domains using antibody perturbation studies and in vitro experiments on tenascin-C fragments. In order to study potential roles of tenascin-C for glial cell biology, a library of recombinant tenascin-C domains was used in a bioassay in vitro. Embryonic day 14 astrocytes, various astroglial-derived cell lines (C6, A7 and Neu7) and oligodendroglial-derived cell types (Oli-neu and G26-20) were examined in an adhesion assay and compared to the neuroblastoma cell line N2A. A binding site for most cell types, except for A7 and N2A, could be assigned to the first three fibronectin type III domains. Repulsive properties could be mapped to three different sites the epidermal growth factor-like repeats, fibronectin type III repeats 4 and 5 and to the alternatively spliced region of the molecule. The responses to these repulsive sites varied according to the cell type. These data are consistent with the interpretation that different cell types express distinct sets of tenascin-C receptors which might regulate cellular responses via distinct second messenger pathways.

Tenascin-C inhibits oligodendrocyte precursor cell migration by both adhesion-dependent and adhesion-independent mechanisms.

Tenascin-C is present within the developing central nervous system during oligodendrocyte precursor cell migration. Tenascin-C is antiadhesive for oligodendrocytes, suggesting a role in controlling the migration of oligodendrocyte precursors and hence the pattern of myelination. Here we show directly that tenascin-C is a repulsive (or antiadhesive) substrate for primary oligodendrocyte precursors and also inhibits their migration. The antimigratory effect of tenascin-C on oligodendroglia is mediated through two distinct mechanisms; reduced substrate adhesion and a direct inhibition of cell migration that is independent of adhesion. These two effects map to different domains of the tenascin-C molecule. The repulsive effect maps to the EGF-like repeats and the alternatively spliced FN III repeats while the direct migration-inhibiting effect maps to FN III repeats 7-8. Our results show tenascin-C to have the novel property of inhibiting migration by both adhesion-dependent and adhesion-independent mechanisms, with different regions of the same molecule responsible for the two effects.

Tenascin-C contains distinct adhesive, anti-adhesive, and neurite outgrowth promoting sites for neurons.

The glia-derived extracellular matrix glycoprotein tenascin-C (TN-C) is transiently expressed in the developing CNS and may mediate neuron-glia interactions. Perturbation experiments with specific monoclonal antibodies suggested that TN-C functions for neural cells are encoded by distinct sites of the glycoprotein (Faissner, A., A. Scholze, and B. Götz. 1994. Tenascin glycoproteins in developing neural tissues--only decoration? Persp. Dev. Neurobiol. 2:53-66). To characterize these further, bacterially expressed recombinant domains were generated and used for functional studies. Several short-term-binding sites for mouse CNS neurons could be assigned to the fibronectin type III (FNIII) domains. Of these, the alternatively spliced insert TNfnA1,2,4,B,D supported initial attachment for both embryonic day 18 (E18) rat and postnatal day 6 (P6) mouse neurons. Only TNfn1-3 supported binding and growth of P6 mouse cerebellar neurons after 24 h, whereas attachment to the other domains proved reversible and resulted in cell detachment or aggregation. In choice assays on patterned substrates, repulsive properties could be attributed to the EGF-type repeats TNegf, and to TNfnA1,2,4. Finally, neurite outgrowth promoting properties for E18 rat hippocampal neurons and P0 mouse DRG explants could be assigned to TNfnB,D, TNfnD,6, and TNfn6. The epitope of mAb J1/tn2 which abolishes the neurite outgrowth inducing effect of intact TN-C could be allocated to TNfnD. These observations suggest that TN-C harbors distinct cell-binding, repulsive, and neurite outgrowth promoting sites for neurons. Furthermore, the properties of isoform-specific TN-C domains suggest functional significance of the alternative splicing of TN-C glycoproteins.

[Total intravenous anesthesia (TIVA) in geriatric surgery. S-(+)-ketamine versus alfentanil]. / Totale intravenöse Anästhesie (TIVA) in der Alterschirurgie. S-(+)-Ketamin versus Alfentanil.

In this prospective, randomized study, two regimens of total intravenous anaesthesia (TIVA), with propofol and S(+)-ketamine (S-ketamine) and with propofol and alfentanil, were compared with reference to endocrine stress response, circulatory effects and recovery. METHODS. The investigation was conducted in two groups of 20 ASA I-III patients over 60 years of age who were scheduled for endoprothetic orthopaedic surgery. After oral premedication with midazolam, patients received a TIVA with body-weight-adjusted doses of propofol, and S-ketamine or alfentanil as the analgesic component. For CPPV (PEEP 5 mbar), air and oxygen (FiO2 33%) were used. For muscle relaxation, patients of both groups received vecuronium in body-weight-adjusted doses. Blood samples were taken through a central venous line at seven time points before induction of anaesthesia and on the first morning after the operation also for analysis of epinephrine, norepinephrine (by HPLC/ECD), and ADH, ACTH and cortisol (by RIA). In addition, SAP, HR, arterial oxygen saturation, recovery from anaesthesia and side effects were observed. RESULTS. The two groups had comparable group mean values for age (S-ketamine group 71 years, alfentanil-group 70 years), other biometric data, and duration of anaesthesia and operation (Table 1). Plasma levels of epinephrine, norepinephrine (Table 2, Fig. 1), ADH (Table 2, Fig. 2) ACTH and cortisol (Table 2, Fig. 3) were higher in the S-ketamine-group (P < 0.05) owing to the intraoperative course of these endocrine parameters. Before induction, and on the first morning after the operation, levels were comparable between the groups. 5 min after the induction of anaesthesia, SAP and HR (Table 3) were significantly lower in the alfentanilgroup (P = 0.001). Recovery from anaesthesia (orientation with respect to person and location) was faster in the alfentanilgroup (16 vs 39 min, P = 0.001). An arterial oxygen saturation below 90% was observed in 7 patients in the S-ketamine- and 13 patients in the alfentanilgroup (P = 0.03). Four patients with S-ketamine reported dreams, and 1 dream was judged negative. Postoperative emesis was found in 6 patients in the S-ketaminegroup and 12 patients in the alfentanilgroup (P = 0.03). All patients said they would agree to undergo the same anaesthetic technique again. CONCLUSIONS. Considerable differences were found in the endocrine stress response of the two groups. With respect to endocrine response and circulation, TIVA with propofol and S-ketamine had sympathomimetic properties with positive circulatory effects and led to moderate endocrine stimulation. This should be kept in mind in patients with hypotension, hypothyrosis, or adrenocortical insufficiency; because "eustress" might be beneficial in this group of patients. On the other hand, TIVA with propofol and alfentanil showed sympatholytic properties, with negative circulatory effects and a remarkable reduction of endocrine stress response. This might be beneficial in patients with hypertension and states of endocrine hyperfunction. Both regimens were accompanied by such typical side effects as dreams, delayed recovery, reduced ventilation, and emesis, which should also be considered.

Cell and molecular analysis of the developing and adult mouse subventricular zone of the cerebral hemispheres.

The subventricular zone (SVZ) of the lateral ventricle remains mitotically active in the adult mammalian central nervous system (CNS). Recent studies have suggested that this region may contain neuronal precursors (neural stem cells) in adult rodents. A variety of neuronal and glial markers as well as three extracellular matrix (ECM) markers were examined with the hope of understanding factors that may affect the growth and migration of neurons from this region throughout development and in the adult. This study has characterized the subventricular zone of late embryonic, postnatal, and adult mice using several neuronal markers [TuJ1, nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d), neuron-specific enolase (NSE)], glial markers [RC-2, vimentin, glial fibrillary acidic protein (GFAP), galactocerebroside (Gal-C)], ECM markers [tenascin-C (TN-C), chondroitin sulfate, a chondroitin sulfate proteoglycan termed dermatan sulfate-dependent proteoglycan-1 (DSD-1-PG)], stem-cell marker (nestin), and proliferation-specific marker [bromodeoxyuridine (BrdU)]. TuJ1+ and nestin+ cells (neurons and stem cells, respectively) persist in the region into adulthood, although the numbers of these cells become more sparse as the animal develops, and they appear to be immature compared to the cells in surrounding forebrain structures (e.g., not expressing NSE and having few, if any, processes). Likewise, NADPH-d+ cells are found in and around the SVZ during early postnatal development but become more sparse in the proliferative zone through maturity, and, by adulthood, only a few labeled cells can be found at the border between the SVZ and surrounding forebrain structures (e.g., the striatum), and even smaller numbers of positive cells can be found within the adult SVZ proper. BrdU labeling also seems to decrease significantly after the first postnatal week, but it still persists in the SVZ of adult animals. The disappearance of RC-2+ (radial) glia during postnatal development and the persistence of glial-derived ECM molecules such as tenascin and chondroitin sulfate proteoglycans (as well as other "boundary" molecules) in the adult SVZ may be associated with a persistence of immaturity, cell death, and a lack of cell emigration from the SVZ in the adult.

[Endocrine stress reaction, hemodynamics and recovery in total intravenous and inhalation anesthesia. Propofol versus isoflurane]. / Endokrine Stressbreaktion, Kreislauf- und Aufwachverhalten bei totaler intravenöser und Inhalationsanästhesie. Propofol versus Isofluran.

This prospective, randomised study compared total intravenous anaesthesia (TIVA) and inhalation anaesthesia with respect to endocrine stress response, haemodynamic reactions, and recovery. METHODS. The investigation included two groups of 20 ASA I-II patients 18-60 years of age scheduled for orthopaedic surgery. For premedication of both groups, 0.1 mg/kg midazolam was injected IM. Patients in the propofol group received TIVA (CPPV, PEEP 5 mbar, air with oxygen FiO2 33%) with propofol (2 mg/kg for induction followed by an infusion of 12-6 mg/kg.h) and fentanyl (0.1 mg before intubation, total dose 0.005 mg/kg before surgery, repetition doses 0.1 mg). For induction of patients in the isoflurane-group, 5 mg/kg thiopentone and 0.1 mg fentanyl was administered. Inhalation anaesthesia was maintained with 1.2-2.4 vol.% isoflurane in nitrous oxide and oxygen at a ratio of 2:1 (CPPV, PEEP 5 mbar). For intubation of both groups, 2 mg vecuronium and 1.5 mg/kg suxamethonium were injected, followed by a total dose of 0.1 mg/kg vecuronium. Blood samples were taken through a central venous line at eight time points from before induction until 60 min after extubation for analysis of adrenaline, noradrenaline (by HPLC/ECD), antidiuretic hormone (ADH), adrenocorticotropic hormone (ACTH), and cortisol (by RIA). In addition, systolic arterial pressure (SAP) heart rate (HR), arterial oxygen saturation (SpO2), and recovery from anaesthesia were observed. RESULTS. Group mean values are reported; biometric data from both collectives were comparable (Table 1). Plasma levels of adrenaline (52 vs. 79 pg/ml), noradrenaline 146 vs. 217 pg/ml), and cortisol (82 vs. 165 ng/ml) were significantly lower in the propofol group (Table 2, Figs. 1 and 3). Plasma levels of ADH (4.8 vs. 6.1 pg/ml) and ACTH (20 vs. 28 pg/ml) did not differ between the groups (Table 2, Figs 2 and 3). SAP (128 vs. 131 mmHg) was comparable in both groups, HR (68/min vs. 83/min) was significantly lower in the propofol group, and SpO2 (97.1 vs 97.4%) showed no significant difference (Table 3). Recovery from anaesthesia was slightly faster in the propofol group (following of simple orders 1.9 vs. 2.4 min, orientation with respect to person 2.4 vs. 3.4 min, orientation with respect to time and space 2.8 vs. 3.7 min), but differences failed to reach statistical significance. CONCLUSIONS. When compared with isoflurane inhalation anaesthesia, moderation of the endocrine stress response was significantly improved during and after TIVA with propofol and fentanyl. Slightly shorter recovery times did not lead to an increased stress response. With respect to intra- and postoperative stress reduction, significant attenuation of sympatho-adrenergic reaction comparable SAP and reduced HR, sympatholytic and hypodynamic anaesthesia with propofol and fentanyl seems to be advantageous for patients with cardiovascular and metabolic disorders. For this aim, careful induction and application of individual doses is essential.

[Total i.v. anesthesia with S-(+)-ketamine in orthopedic geriatric surgery. Endocrine stress reaction, hemodynamics and recovery]. / TIVA mit S-(+)-Ketamin in der orthopädischen Alterschirurgie. Endokrine Stressreaktion, Kreislauf- und Aufwachverhalten.

UNLABELLED: Clinically-used ketamine is a racemic mixture of two isomers, S-(+)- and R-(-)-ketamine. Previous investigations showed the anaesthetic potency of S(+)-ketamine to be three times higher than that of R-(-)-ketamine. It was the aim of this study to compare the effects of S-(+)-ketamine and racemic ketamine on endocrine and cardiovascular parameters, recovery, and side effects in geriatric patients during total intravenous anaesthesia (TIVA) for orthopaedic surgery. METHODS: Forty patients over 60 years of age scheduled for elective hip or knee replacement were investigated in a double-blind, randomised design. For induction of TIVA, patients received 0.1 mg midazolam, 0.5 mg atropine, 1 mg/kg S(+)-ketamine or 2 mg/kg racemic ketamine, respectively, 2 mg vecuronium, and 1.5 mg/kg suxamethonium. After intubation and relaxation with a total dose of 0.1 mg/kg vecuronium, a continuous infusion of 2 mg/kg per hour S-(+)- or 4 mg/kg per hour racemic ketamine was administered throughout surgery. Blood samples were taken through a central venous catheter at seven time-points, before induction as well during and after surgery, until the 1st postoperative morning for analysis of adrenaline, noradrenaline (by high-pressure liquid chromatography with electrochemical detection), anti-diuretic hormone (ADH), adrenocorticotropic hormone (ACTH), cortisol (by radioimmunoassay), glucose, and lactate. In addition, systolic arterial pressure (SAP), heart rate (HR), and arterial oxygen saturation were measured, and the time intervals between the end of ketamine infusion and the return of consciousness and orientation were protocolled. The incidence and assessment of dreams and other side effects were reported by the patients. RESULTS: Biometric data of the groups were comparable, the mean age of both groups being 68 years. Plasma adrenaline, noradrenaline, ADH, ACTH, cortisol, and glucose as well as SAP and HR increased significantly (P < 0.05) during the course of anaesthesia. The influence on lactate levels was not significant. There were no differences between S(+)- and racemic ketamine with respect to these parameters. Three patients in the ketamine-racemate group showed severe arterial hypertension and were withdrawn from the study. Recovery clearly improved after administration of S(+)-ketamine compared to the racemate. Simple orders were followed after 2.0 +/- 3.4 versus 4.9 +/- 6.8 min (P = 0.07), orientation with respect to person returned after 5.7 +/- 4.0 versus 14.6 +/- 10.0 min (P < 0.001) and spatial orientation after 8.2 +/- 5.4 versus 17.4 +/- 9.7 min (P < 0.001). After racemic ketamine, 1 patient remembered a negative dream and 1 patient a positive dream. In the S(+)-group, 1 positive dream was reported. No intraoperative awareness was reported, and all patients would accept the same anaesthesia again. CONCLUSIONS: Increases in cardiovascular parameters and insufficient reduction of the stress response with respect to ADH, ACTH, and cortisol seem to require a more potent hypnotic element during TIVA with ketamine. With regard to endocrine and cardiovascular parameters, the pharmacodynamic effects of racemic and S-(+)-ketamine were comparable. Because of the significant improvement in recovery and the reduced quantitative drug load, S-(+)-ketamine offers a clinical advantage compared with currently used racemic ketamine.

Tenascin glycoproteins in developing neural tissues: only decoration?

Tenascin glycoproteins constitute a growing family of extracellular matrix molecules that are transiently expressed by astrocytes during the development of the central nervous system (CNS). In some areas, tenascin distribution is discrete and tenascin boundaries delineate emerging functional processing units, for example, in the somatosensory cortex. The intact adult CNS displays low levels of expression and up-regulation of tenascin after lesion or in glial tumors. In vitro studies using the purified glycoprotein, bacterially expressed tenascin fusion proteins, monoclonal antibodies, and defined cell culture models have established that tenascin glycoproteins possess cell-binding sites for neural cells, support neuronal migration and the formation of neurites. On the other hand, tenascin also embodies repulsive, inhibitory properties that could serve to conceal neuronal assemblies and to segregate emerging fiber tracts. These functional properties are encoded by distinct domains of the molecule and suggest that tenascin glycoproteins are involved in neural pattern formation and regeneration. This interpretation is discussed with reference to a recent report that the elimination of the tenascin gene does not cause obvious abnormalities of neural tissues.

Expression and partial characterization of a cathepsin B-like enzyme (Sm31) and a proposed 'haemoglobinase' (Sm32) from Schistosoma mansoni.

Schistosoma mansoni protein Sm31 is a cysteine proteinase similar to mammalian lysosomal cathepsin B, proposed to be a key enzyme in schistosome metabolism. Protein Sm32 has been identified as a putative cysteine proteinase termed a 'haemoglobinase'. Since neither Sm31 nor Sm32 have been completely purified, some controversy of the nature of the 'true' digestive enzyme still exists. By incubating a radiolabelled cysteine-proteinase active-site-directed synthetic inhibitor with total S. mansoni proteins, the target of inhibition was Sm31 and not Sm32. The selectivity and irreversibility of inactivation make affinity labelling an invaluable tool for exploring key differences among closely related enzymes and also for studying proteinase activity in a cellular environment. In order to confirm these results, we expressed the complete cDNA sequences of Sm31 and Sm32 in insect cells and analysed the recombinant gene products for proteolytic activities. Cell extracts containing S. mansoni cathepsin B, but not those expressing 'haemoglobinase', were demonstrated to cleave a synthetic substrate benzyloxycarbonyl-arginylarginylaminomethylcoumarin in fluorescence assays. Our findings confirm previous assertions that a cysteine proteinase resembling cathepsin B is the haemoglobinase involved in digestion of host proteins. Thus, the original proposal that Sm32 is a cysteine proteinase has not been verified, and its function remains unknown.

Expression of an active cathepsin B-like protein Sm31 from Schistosoma mansoni in insect cells.

Recombinant Schistosoma mansoni cathepsin B was produced in insect cells via the baculovirus expression vector system as a 37.5 kDa precursor molecule and a 31 kDa mature enzyme. Extracts prepared from cells infected with the recombinant virus were able to cleave a synthetic dipeptide substrate specific for cathepsin B. Proteolytic activity was inhibited by trans-epoxysuccinyl-L-leucyl-amido (4-guanidino) butane (E64) but not by phenylmethylsulphonyl-fluoride (PMSF), pepstatin and 1,10-phenanthroline. Specific inhibition by diazomethylketone derivatives, which bind covalently to the active centre of cysteinyl proteinases was also demonstrated.

[The work of the Hessian Medical Office]. / Die Arbeit der Arztlichen Stellen.

The task of this committee on quality control and radiation protection is described, along with an explanation of the legal principles used in the execution of its duties (Nuclear Safety Law and Radiological Ordinance). Furthermore, the procedures used for the evaluation of X-rays are illustrated, followed by test films of X-ray equipment and film developers. Finally, the composition and activities of the Radiation Protection Committee are described.

Developmental and personality correlates of adrenocortical activity as indexed by salivary cortisol: observations in the age range of 35 to 65 years.

Unstimulated salivary cortisol concentrations were measured in 767 adults aged 35-65 yr over the course of one day. Interindividual differences in early morning cortisol concentrations showed consistent and significant relationships with demographic and psychological variables. Socioeconomic status was positively associated with cortisol levels. Relationships of cortisol levels with age were moderated by gender: for women, a negative regression of cortisol level on age was observed while no significant age effects were obtained for men. In bivariate and multivariate regression analyses, a positive association between cortisol levels and indicators of successful development and personal well-being was observed; these relationships were more pronounced for the male sample. Intradyadic correlations further revealed a slight but significant association of morning cortisol levels within married couples. The findings are discussed with respect to mediating developmental mechanisms and pathophysiological implications.