Archaea are prominent members of the prokaryotic communities colonizing common forest mushrooms.

In this study, the abundance and composition of prokaryotic communities associated with the inner tissue of fruiting bodies of Suillus bovinus, Boletus pinophilus, Cantharellus cibarius, Agaricus arvensis, Lycoperdon perlatum, and Piptoporus betulinus were analyzed using culture-independent methods. Our findings indicate that archaea and bacteria colonize the internal tissues of all investigated specimens and that archaea are prominent members of the prokaryotic community. The ratio of archaeal 16S rRNA gene copy numbers to those of bacteria was >1 in the fruiting bodies of four out of six fungal species included in the study. The largest proportion of archaeal 16S rRNA gene sequences belonged to thaumarchaeotal classes Terrestrial group, Miscellaneous Crenarchaeotic Group (MCG), and Thermoplasmata. Bacterial communities showed characteristic compositions in each fungal species. Bacterial classes Gammaproteobacteria, Actinobacteria, Bacilli, and Clostridia were prominent among communities in fruiting body tissues. Bacterial populations in each fungal species had different characteristics. The results of this study imply that fruiting body tissues are an important habitat for abundant and diverse populations of archaea and bacteria.

The distribution of digenean metacercariae within bream (Abramis brama) gill apparatus: preferences, co-occurrence and interactions of parasites.

Species-specific microenvironmental preferences and interactions between parasite species have been the focus of many ecological studies. Here, we studied the distribution of ectoparasite species within the gill apparatus of bream (Abramis brama) from Lake Lubans (Latvia) to establish whether digenean metacercariae: (1) prefer specific patches within the gill apparatus; (2) co-occur in the same patches with monogeneans and copepods within a host individual; and (3) interact with monogeneans and copepods. We recorded all parasites on gill arches of the same host species and used null models to analyse co-occurrences of digenean metacercariae, monogeneans and copepods. Zero-inflated mixture models were used to define the preferred patches of parasites. We found that digenean metacercariae (Bucephalus polymorphus) prefer specific patches of the gill apparatus to encyst, and shared these preferences with monogeneans and copepods, but did not interact with them. We concluded that digenean metacercariae have a species-specific microenvironmental preference to encyst in the gill apparatus and their occurrence (even in high numbers) does not reduce the success of attachment of monogeneans and copepods in the same gill patches.

Natural decay process affects the abundance and community structure of Bacteria and Archaea in Picea abies logs.

Prokaryotes colonize decaying wood and contribute to the degradation process, but the dynamics of prokaryotic communities during wood decay is still poorly understood. We studied the abundance and community composition of Bacteria and Archaea inhabiting naturally decaying Picea abies logs and tested the hypothesis that the variations in archaeal and bacterial abundances and community composition are coupled with environmental parameters related to the decay process. The data set comprises >500 logs at different decay stages from five geographical locations in south and central Finland. The results show that Bacteria and Archaea are an integral and dynamic component of decaying wood biota. The abundances of bacterial and archaeal 16S rRNA genes increase as wood decay progresses. Changes in bacterial community composition are clearly linked to the loss of density of wood, while specific fungal-bacterial interactions may also affect the distribution of bacterial taxa in decaying wood. Thaumarchaeota were prominent members of the archaeal populations colonizing decaying wood, providing further evidence of the versatility and cosmopolitan nature of this phylum in the environment. The composition and dynamics of the prokaryotic community suggest that they are an active component of biota that are involved in processing substrates in decaying wood material.

Quantification of toxic Microcystis spp. during the 2003 and 2004 blooms in western Lake Erie using quantitative real-time PCR.

In August of 2003 and August of 2004, blooms of potentially toxic cyanobacteria Microcystis spp. persisted in western Lake Erie. Samples collected from the bloom were analyzed for the cyanobacterial toxin microcystin and the presence of Microcystis spp. cells. Estimates of microcystin toxicity exceeding 1 microg L(-1) (microcystin-LR activity equivalents), the safety limit set by the World Health Organization, were found from the samples in both 2003 and 2004. The presence of Microcystis spp. in water samples was confirmed through standard polymerase chain reaction (PCR) using a combination of four primer sets. Quantification of Microcystis was accomplished by a real-time PCR assay utilizing specific primer-Taq-man probe sets targeted on a conserved, Microcystis-specific 16S rDNA fragment and a microcystin toxin synthetase gene mcyD. This approach allowed us to specifically study the distribution and abundance of toxic Microcystis in the lake in contrast to previous studies that have assessed Microcystis populations with less refined methods. On the basis of quantification by quantitative real-time PCR analysis, the total abundance of Microcystis cells in the bloom area varied from 4 x 10(8) to 2 x 10(3) cells L(-1). The results of this study provide novel insight regarding the distribution and abundance of Microcystis spp. in the western basin of Lake Erie, a region plagued in recent years by large-scale (>20 km2) blooms. Our results suggest that the Maumee River and Bay may serve as a source for Microcystis to western and central Lake Erie.

A survey of current usage of anticholinergic drugs in paediatric anaesthesia in Finland.

BACKGROUND: The aim of this survey was to obtain information about the current use of anticholinergic preanaesthetic medication in children. It was carried out as a follow-up study of the previous survey amongst Finnish anaesthesiologists in 1990. METHODS: A questionnaire was send to all members of the Finnish Society of Anaesthesiologists. Data from anaesthesiologists taking care of at least three paediatric anaesthesias/week (n= 183) were analyzed. RESULTS: In 1998 only one-third of the Finnish anaesthesiologists routinely used anticholinergics before paediatric anaesthesia. The main indications for routine anticholinergic premedication were ENT surgery (66%), eye surgery (71%) and endoscopic procedures (67%). Anticholinergic drugs were administered principally via the intravenous route (90%) briefly before induction of anaesthesia, and glycopyrrolate was the most frequently used (66%). CONCLUSION: During the last eight years in Finland the routine use of anticholinergic premedication has decreased. As in 1990 the anticholinergic prophylaxis is directed to ENT and eye surgery, endoscopic procedures and to children younger than 1 year. Use of glycopyrrolate has gained popularity at the expense of atropine and scopolamine.

Metabolic and clinical responses to different types of premedication in children.

The metabolic and clinical responses to intravenously administered atropine+meperidine (pethidine), glycopyrrolate+meperidine, diazepam and placebo were examined in 76 healthy children. After atropine+meperidine and glycopyrrolate+meperidine administration, a significant antisialogogue effect, tachycardia and elevation in systolic blood pressure were observed. Diazepam decreased oxygen consumption (VO2) whereas atropine+meperidine increased both VO2 and energy expenditure (EE). The maximal effect of diazepam on VO2 was found 10 min after drug administration (mean difference from baseline -10.0%) and maximal effect of atropine+meperidine on VO2 and EE after 5 min (mean difference from baseline +6.0% and +3.3%, respectively). It is concluded that intravenous administration of meperidine with atropine or glycopyrrolate is followed by profound anticholinergic effects and such combinations do not appear to be suitable for clinical purposes. Although statistically significant, the alterations in VO2 and EE after diazepam and atropine+meperidine premedication can be considered clinically insignificant because they were of short duration and the measured changes represented only a fraction of fluctuation seen in normal values.

Comparison of the analgesic effects of intrabursal oxycodone and bupivacaine after acromioplasty.

STUDY OBJECTIVES: To compare the peripheral analgesic effect of oxycodone, an opioid agonist, to the effect of bupivacaine infiltration and parenteral oxycodone administration in conjunction with shoulder surgery. DESIGN: Prospective, randomized, double-blind study. SETTING: University teaching hospital. PATIENTS: 42 ASA physical status I and II patients scheduled for shoulder surgery with general anesthesia. INTERVENTIONS: Patients were randomized to three study groups: at the end of the surgery patients received either 10 ml of 0.5% bupivacaine (group BIB) or 5 mg of oxycodone in 10 ml of saline (group OIB) in the subacromial bursa; or 5 mg of oxycodone intramuscularly (group OIM). Postoperative analgesia was provided by patient-controlled analgesia (PCA). MEASUREMENTS AND MAIN RESULTS: The fentanyl requirements were recorded for the 24-hour postoperative period and the total perioperative period. Postoperative pain was assessed by visual analog scale for pain (VASP). Plasma oxycodone concentrations were measured in groups OIB and OIM. The total perioperative fentanyl consumption was significantly lower in groups BIB (0.97 +/- 0.09 mg) and OIB (1.23 +/- 0.12 mg) than in group OIM (1.61 +/- 0.12 mg) (p = 0.01 and 0.048, respectively). Groups BIB and OIB were similar (p = 0.34). The absorption of oxycodone was significantly lower after subacromial than after intramuscular administration. CONCLUSION: Intrabursal oxycodone and intrabursal bupivacaine reduced perioperative analgesic requirements similarly. Intrabursal oxycodone may offer an effective, simple, and safe method for postoperative analgesia after shoulder surgery.

Spectral analysis of heart rate variability as a quantitative measure of parasympatholytic effect--integrated pharmacokinetics and pharmacodynamics of three anticholinergic drugs.

The time course and concentration-effect relationship of parasympatholytic effects of three anticholinergic drugs were investigated using spectral analysis of heart rate (HR) variability. Single intravenous (i.v.) doses of atropine (10 microg/kg), glycopyrrolate (5 microg/kg), scopolamine (5 microg/kg), and placebo were given to eight healthy volunteers in a double-blind, randomized cross-over study. Electrocardiogram (ECG) was recorded at baseline and 2.5, 5, 10, 20, and 30 minutes, and 1, 1.5, 2, 3, 4, 5, and 6 hours after drug administration, while the subjects breathed at a fixed 0.25 Hz frequency. The powers of two frequency bands (low frequency [LF] = 0.07-0.15 Hz and high frequency [HF] = 0.15-0.40 Hz) were calculated using stationary time series of R-R intervals (RRI) free from ectopic beats. To perform pharmacokinetic-pharmacodynamic (PK-PD) modeling, venous plasma drug concentrations were measured. Atropine and glycopyrrolate, and, to a lesser extent, scopolamine induced decreases in HF power and increases in LF/HF ratio of HR variability, indicating parasympatholytic activity and corresponding changes in sympathovagal balance. Maximal average decreases in HF power were 99%, 94%, and 82%, respectively, but in two scopolamine subjects, a parasympathomimetic effect was dominant. Interindividual variability was least for the Hayano index of HF power (square root (RRI HF-power)/RRI*100), and profound and consistent decreases were seen after atropine and glycopyrrolate. Pharmacokinetics were best fitted to a two-compartment open model, and effect compartment link modeling using the Hayano index was performed with the atropine and glycopyrrolate data. The best description of the PK-PD relationship for both drugs was achieved using the sigmoidal Emax model. Mean (+/-SD) EC50, sigmoidicity factor (gamma), and equilibration rate constant (k(e0)) estimates were 1.35 (+/-0.27) ng/mL, 6.07 (+/-1.98) and 11.0 (+/-5.28) l/h for atropine and 1.35 (+/-0.49) ng/mL, 4.34 (+/-1.55) and 2.26 (+/-0.81) l/h for glycopyrrolate. Spectral analysis of HR variability appears to be a powerful tool in monitoring parasympatholytic drug activity. A sigmoidal Emax model with an extremely steep concentration-response relationship was revealed for atropine and glycopyrrolate. The effects of scopolamine were more incongruous.

Pharmacokinetics and oral bioavailability of glycopyrrolate in children.

Based on plasma levels determined with a radioreceptor assay and following a single oral (50 micrograms/kg) and intravenous (5 micrograms/kg) administration of glycopyrrolate in six healthy children operated twice during a several weeks period, a negligible and variable oral bioavailability was found (3.3; 1.3-13.3%) (median;range). No significant changes in heart rate after oral or intravenous administration of the drug could be seen. Oral glycopyrrolate appears to have no place in paediatric premedication.

The effect of clonidine or midazolam premedication on perioperative responses during ketamine anesthesia.

UNLABELLED: The use of ketamine as a sole anesthetic induces marked central sympathetic stimulation, causing increased heart rate, blood pressure (BP), and oxygen consumption (VO2). Both alpha 2-agonists and benzodiazepines have been used to attenuate these potentially harmful ketamine-induced responses. This double-blind, randomized, placebo-controlled study was designed to compare the perioperative metabolic, hemodynamic, and sympathoadrenal responses to IM clonidine (2 micrograms/kg) and midazolam (70 micrograms/kg) premedication during ketamine anesthesia. VO2 was measured continuously using indirect calorimetry in 30 ASA physical status I patients. The patients received ketamine, mivacurium, and fentanyl for the induction of anesthesia. Anesthesia was maintained using a ketamine infusion and fentanyl boluses i.v. Preoperatively, both VO2 and BP decreased significantly after the administration clonidine and midazolam compared with placebo (P < 0.01). Intraoperatively, VO2 was higher in the midazolam group than in the placebo and clonidine groups (P < 0.05). Postoperatively, there were no significant differences in BP and VO2, although they stayed at lower level in the clonidine group during the whole postoperative period. Clonidine decreased pre- and postoperative plasma catecholamine concentrations (P < 0.05). Our results indicate that a midazolam-ketamine combination may induce potentially harmful metabolic stimulation, whereas the sympatholytic effects of clonidine on ketamine-anesthetized patients may be beneficial, as perioperative VO2 was decreased. IMPLICATIONS: Ketamine causes sympathetic stimulation with an ensuing increase in oxygen consumption. Anticipating that clonidine might attenuate this response, we measured oxygen consumption in patients undergoing surgery during ketamine anesthesia. Patients treated with a clonidine-ketamine combination had lower intra- and postoperative oxygen consumption than those treated with a midazolam-ketamine combination.

The effects of branched chain amino acid infusion on pain perception and plasma concentrations of monoamines.

Infusions of branched chain amino acids (BCAA) have been shown to have several CNS-mediated effects including antinociceptive action. We investigated the effects of BCAA infusion on pain perception, respiratory control, and plasma monoamine concentrations. Six healthy female volunteers were given in a double-blind, random, crossover design an 8-h infusion (1.75 ml/kg/h) of either (a) Ringers lactate, (b) conventional 4% amino acid solution, or (c) 4% BCAA solution with intervals of at least 48 h. Respiratory control was evaluated with continuous capnography. Pain perception was measured using dental dolorimetry for sharp pain, and pain transmitted by afferent C-fibers was evaluated with tourniquet test. Changes in vigilance were measured using critical flicker fusion technique. Evaluations were made for baseline, and after 2.5, 5, and 8 h. Plasma samples were collected at the same time points for amino acid and monoamine analysis. BCAA infusion resulted in significant increases of plasma concentrations of all BCAAs, with a simultaneous decrease in concentrations of aromatic amino acids. Of the measured monoamines and their metabolites dihydroxyphenylacetic acid (DOPAC) decreased, showing significant treatment effect for BCAA. Despite these changes no significant effect of BCAAs on respiratory control, vigilance, or pain perception was observed. In conclusion, despite significant changes in plasma concentrations of both amino acids and DOPAC, BCAA infusion did not show any clinically relevant antinociceptive effect.

Pharmacokinetics and clinical effects of intramuscular scopolamine plus morphine. A comparison of two injection sites.

BACKGROUND: Intramuscular scopolamine plus morphine premedication is traditionally used when prominent sedative or antisialogogue effect is needed. Knowledge of the pharmacokinetics of scopolamine is limited due to low plasma concentrations found after therapeutic doses. This investigation compares the pharmacokinetics and the clinical responses of this drug combination injected into two commonly used injection sites. METHODS: Twelve ASA class 1 patients scheduled for minor surgery under spinal anaesthesia received scopolamine 6 micrograms/kg plus morphine 200 micrograms/kg injected in either deltoid (group D, n = 6) or gluteal (group G, n = 6) muscle. RESULTS: The peak plasma concentrations of scopolamine after deltoid or gluteal injection (2.2 vs 1.6 micrograms/l) and the time they were reached (17 vs 19 min) were comparable. The absorption of morphine was similar in both groups (Tmax 16 min), but the peak plasma concentrations were higher after deltoid injection (71 vs 49 micrograms/l). The individual variation in the elimination half-lives of both scopolamine and morphine was smaller after deltoid injection (T1/2 scopolamine 1.9 +/- 0.7 vs 2.1 +/- 1.1 h, morphine 1.3 +/- 0.7 vs 2.3 +/- 1.5 h). Moderate slowing (25%) of heart rate was found in both groups. A heavy sedation and antisialogogue effect (VAS) was found in both groups with faster occurrence of maximal effect in group D (60 vs 120-180 min). CONCLUSION: More predictable pharmacokinetics and clinical effects of intramuscular scopolamine plus morphine premedication can be achieved after an injection into deltoid muscle.

Reduction of the minimum alveolar concentration of isoflurane by dexmedetomidine.

BACKGROUND: alpha 2-Adrenergic agonists have been shown to reduce anesthetic requirements of other anesthetics, and they may even act as complete anesthetics by themselves at high doses in animal models. The present study was designed to define the interaction of intravenous infusion of dexmedetomidine, an alpha 2-adrenergic agonist, and isoflurane in patients having surgery by using the minimum alveolar concentration (MAC) of isoflurane as the measure of anesthetic potency. METHODS: Forty-nine women scheduled for abdominal hysterectomy were randomly allocated to receive either a placebo infusion (n = 16) or a two-stage infusion of dexmedetomidine with target plasma concentration of 0.3 ng/ml (n = 17) or 0.6 ng/ml (n = 16). The study drug infusion was commenced 15 min before induction of anesthesia with thiopental and alfentanil and was continued until skin incision. The end-tidal concentration of isoflurane for each patient was predetermined according to the "up-down" method of Dixon, and it was maintained for at least 15 min before the patient's response to skin incision was assessed. RESULTS: The MAC of isoflurane was 0.85% end-tidal in the control group, 0.55% end-tidal with the low dose of dexmedetomidine, and 0.45% end-tidal with the high dose of dexmedetomidine. CONCLUSIONS: The MAC of isoflurane in the control group was lower than that reported previously in similar patients having surgery, probably due to anesthesia induction with thiopental and alfentanil. Nevertheless, with the high dose of dexmedetomidine, the MAC of isoflurane was still 47% less than that without dexmedetomidine.

Effect of clonidine and dexmedetomidine premedication on perioperative oxygen consumption and haemodynamic state.

Premedication has been shown to affect both oxygen consumption and metabolic rate. We have compared the perioperative metabolic and haemodynamic effects of two alpha 2-agonists, clonidine and the more selective dexmedetomidine, in 30 ASA I patients undergoing plastic surgical procedures under general anaesthesia. Patients were premedicated with clonidine 4 micrograms kg-1 (n = 10), dexmedetomidine 2.5 micrograms kg-1 (n = 10) or saline (n = 10) i.m. The doses of clonidine and dexmedetomidine were intended to be equipotent. The maximum decrease in preoperative oxygen consumption was 8% and decreases in systolic and diastolic arterial pressures were 11% from baseline after clonidine and dexmedetomidine. During operation, the maximum reduction in heart rate was 18% in the clonidine and dexmedetomidine groups compared with the placebo group. After operation, the maximum decrease in systolic arterial pressure was 11%, diastolic arterial pressure 15% and oxygen consumption 17% in the clonidine and dexmedetomidine groups compared with placebo. In summary, both clonidine 4 micrograms kg-1 and dexmedetomidine 2.5 micrograms kg-1 decreased perioperative oxygen consumption effectively, with a similar haemodynamic profile.

Cardiovascular and metabolic responses to clonidine and midazolam premedication.

In this double-blind placebo controlled study the preoperative cardiovascular and metabolic effects of intramuscular (i.m.) clonidine and midazolam are assessed. Forty-five ASA Grade I patients (n = 15 per group) undergoing plastic surgical procedures were randomly allocated to receive either placebo, clonidine 4 micrograms kg-1 or midazolam 70 micrograms kg-1. Drugs were administered into the deltoid muscle approximately 90 min prior to the scheduled induction of anaesthesia. The metabolic measurements were performed using an indirect calorimetry device. Heart rate and blood pressure were measured noninvasively. Pre-operative subjective anxiety, dryness of mouth and tiredness were assessed using visual analogue scales (VAS). Clonidine increased subjective tiredness significantly more than placebo. Clonidine also induced moderate decreases in blood pressure and heart rate. Oxygen consumption (VO2), CO2 production and energy expenditure (EE) decreased significantly after clonidine and midazolam. The decrease in VO2 and EE was maximally 11-14% on average from the base-lines after clonidine and midazolam. These effects were of longer duration after clonidine and lasted until the end of the 90 min study period. In conclusion, both clonidine and midazolam are effective as a means of decreasing pre-operative VO2 and EE.

Pharmacological premedication for anaesthesia.

The psychological component of preoperative preparation should be completed with a selective use of drugs. The days of poly-pharmacy are over. Heavily sedated patients coming to the operation room with minimal oral secretions are not the purpose of modern premedication. Anxiolysis and slight sedation (painless patients) and analgesia (patients suffering from pain) are the main goals. Anticholinergics should be used only when needed, as is the case with premedication generally. The use of antiemetics and that of agents given for prophylaxis against allergic reactions or aspiration pneumonitis depend on specific needs of the patient. More accurate and generally accepted but simple methods are needed in studying the effects of different premedicants. The present results produced with a huge number of different more or less validated assessments can seldom be compared with each other.