Fixation of metals in soil constituents and potential remobilization by hyperaccumulating and non-hyperaccumulating plants: results from an isotopic dilution study

In this study isotopic dilution methods were used to investigate the hypothesis that access to metals associated with specific chemical components in the soil that are not available to non-accumulator species could be involved in hyperaccumulation. The hyperaccumulator Thlaspi caerulescens and a non-accumulator species, Brassica napus, were grown in Cd and Zn enriched soil components calcite, goethite, charcoal and cryptomelane. The metal enriched components were aged to allow transformation of a proportion of added metals to non-labile forms. Results from the isotopic dilution L value method showed that despite taking up more metals, T. caerulescens accessed the same pool of metals as B. napus. Hence differential access to different solid-phase pools of metals appears to be an unlikely mechanism underlying metal hyperaccumulation. For all components except charcoal, L values for Cd and Zn were greater than the corresponding E values suggesting that E values may tend to underestimate the bioavailable fraction of metals in soils.

Cadmium tolerance and hyperaccumulation by Thlaspi caerulescens populations grown in hydroponics are related to plant uptake characteristics in the field

In order to fully understand the hyperaccumulation process and to increase the potential of plants for phytoextraction purposes, there is a need for more investigation of hyperaccumulating species or populations. Five Swiss populations of Thlaspi caerulescens J. & C. Presl originating from non-metalliferous but naturally Cd-rich soils (1.1-9.2 mg Cd kg^-1) were compared with Ganges and Prayon populations and a non-accumulating species, Thlaspi perfoliatum (L.) F.K. Meyer, for their tolerance (shoot and root dry weight and root length) and Cd hyperaccumulation in hydroponics (0, 1, 5, 10, 20 and 50 μm Cd). In the field, the Swiss populations accumulated Zn and clearly hyperaccumulated Cd (up to 505 mg Cd kg^-1 dry weight). The general response was significantly different between populations but in general an increasing Cd concentration in solution led to a decrease in dry weight production and an increase in Cd concentration in shoots. The shoot dry weight was a more discriminating parameter for tolerance than root dry weight and total root length. The Swiss populations behaved similarly to the Ganges population but differently from the Prayon population. Cadmium concentrations in shoots were above 100 mg kg^-1 when plants were grown in 1 μm Cd, except for the Prayon population and T. perfoliatum. In addition, as 1 μm Cd did not induce any visible toxicity symptoms, it was found to be adequate to test Cd hyperaccumulation. However, the most striking feature was the positive linear relationship observed between the transfer factor (TF) calculated in the field and the response of a population to increasing Cd concentrations in solution, indicating that plant uptake in the field had an influence on the plant response in solution.

Beatmung eines ungeschützten Atemwegs

BACKGROUND

Currently 30 chest compressions and 2 ventilations with an inspiratory time of 1 s are recommended during cardiopulmonary resuscitation with an unprotected airway, thus spending about 15% instead of 40% of resuscitation time on ventilation. Time could be gained for chest compressions when reducing inspiratory time from 2 s to 1 s, however, stomach inflation may increase as well.

METHODS

In an established bench model we evaluated the effect of reducing inspiratory time from 2 s to 1 s at different lower oesophageal sphincter pressure (LOSP) levels using a novel peak inspiratory-flow and peak airway-pressure-limiting bag-valve-mask device (Smart-Bag).

RESULTS

A reduction of inspiratory time from 2 s to 1 s resulted in significantly lower peak airway pressure with LOSP of 0.49 kPa (5 cm H2O), 0.98 kPa (10 cm H2O) and 1.47 kPa (15 cm H2O) and an increase with 1.96 kPa (20 cm H2O). Lung tidal volume was reduced with 1 s compared to 2 s. When reducing inspiratory time from 2 s to 1 s, stomach inflation occurred only at a LOSP of 0.49 kPa (5 cm H2O).

CONCLUSIONS

In this model of a simulated unprotected airway, a reduction of inspiratory time from 2 s to 1 s using the Smart-Bag resulted in comparable inspiratory peak airway pressure and lower, but clinically comparable, lung tidal volume. Stomach inflation occurred only at a LOSP of 0.49 kPa (5 cm H2O), and was higher with an inspiratory time of 2 s vs 1 s.

High concentration potassium permanganate eliminates protein and particle contamination of the reusable Classictm laryngeal mask airway

In this three-stage study, we test the hypothesis that supplementary cleaning with potassium permanganate > or =4 mg.l(-1) eliminates protein and particle contamination from the reusable Classic laryngeal mask airway. The first stage involved supplementary cleaning of 70 1 x 1 cm segments from deliberately contaminated laryngeal mask airways using potassium permanganate at 0, 2, 4, 8, 16, 32 and 64 mg.l(-1) and testing for protein staining. This showed that the lowest concentration required to eliminate protein contamination was 8 mg.l(-1). The second stage involved supplementary cleaning of 50 used laryngeal mask airways with either potassium permanganate 8 mg.l(-1) or saline and testing for protein staining. This showed that protein contamination was lower in the potassium permanganate group (p < 0.00001): all laryngeal mask airways in the control group and none in the potassium permanganate group were contaminated. The third stage involved scanning electron microscopic examination of 1 x 1 cm segments from three laryngeal mask airways used in the control group, three from the potassium permanganate group, plus three brand new laryngeal mask airways. The mean density of > or =1 mum surface particles was lower in the potassium permanganate 8 mg.l(-1) than the control group (21 vs. 121 .cm(-2), p < 0.0001) and was similar to brand new laryngeal mask airways (24 .cm(-2)). We conclude that supplementary cleaning with potassium permanganate 8 mg.l(-1) eliminates protein deposits from reusable laryngeal mask airways and reduces particle contamination to similar levels to brand new laryngeal mask airways.

Protein cross-contamination during batch cleaning and autoclaving of the ProSeal laryngeal mask airway

We tested the hypothesis that protein cross-contamination occurs during batch cleaning and autoclaving of a reusable extraglottic airway device, the ProSeal laryngeal mask airway. At the end of each day for 10 days, nine laryngeal mask airways that had been used for non-intra-oral surgery were cleaned and autoclaved alongside a new unused laryngeal mask airway. In addition, a new unused laryngeal mask airway underwent the same cleaning and autoclaving procedures in isolation. Protein staining was more frequently detected on the unused laryngeal mask airways that were processed by batch rather than in isolation (p < 0.01). Protein staining was detected on all unused laryngeal mask airways that were processed by batch, but none on those processed in isolation. Protein staining was more severe with the used compared with the unused laryngeal mask airways (p < 0.001). We conclude that protein cross-contamination of the laryngeal mask airway occurs during batch cleaning and autoclaving and recommend that reusable airway devices are cleaned in isolation.

Purification and characterization of a novel glucuronan lyase from Trichoderma sp. GL2

The filamentous fungus Trichoderma sp. GL2 produces an extracellular glucuronan lyase (GL) when grown on glucuronan as the sole carbon source. In this paper, we report the purification to electrophoretical homogeneity of this polysaccharide lyase by size exclusion chromatography and anion exchange chromatography. The purified GL, classified as an endopolyglucuronate lyase, is a monomer with an apparent molecular weight of 27 kDa and an isoelectric point of 6.95. Despite an inhibition of the activity when polysaccharide substrates were substituted by acetates, the enzyme was active toward glucuronans (acetylated or not) and ulvan, leading to various (4,5)-unsaturated products as oligoglucuronans (acetylated or deacetylated), highly acetylated low-molecular-weight (LMW) glucuronans, and LMW ulvans.

[Analgesia with remifentanil in spontaneously breathing patients undergoing brief but painful radiological procedures]

INTRODUCTION

Percutaneous transhepatic biliary drainage (PTBD) and stenting are very painful procedures in interventional radiology and require potent analgesia; employing remifentanil in spontaneously breathing patients may be one possible strategy.

PATIENTS AND METHODS

The study group was composed of 18 men and 2 women with a mean age of 63+/-10 (mean+/-SD) years. Pain intensity was measured with a VAS score before the procedure, after local anesthesia on the rib cage, after stenting and after the radiology procedure.

RESULTS

Remifentanil infusion (dosage: 0.12-0.30 microg/kg body weight/min) was infused throughout the entire radiology procedure according to physical status, past medical history, individual pain, and clinical assessment. During insufflation of 10l O(2)/min via a venturi mask, oxygen saturation did not fall below 96% at any time-point during the procedure. In the VAS score, we noted a decrease after starting the remifentanil infusion towards the end of procedure. All patients were able to move into bed without help. Postoperatively, no analgesics and no antiemetics were needed.

CONCLUSIONS

Employing a remifentanil infusion for brief interventional radiology procedures in palliative treatment of patients resulted in high patient and radiologist comfort.

Bougie-guided insertion of the ProSeal™ laryngeal mask airway has higher first attempt success rate than the digital technique in children

BACKGROUND

We tested the hypothesis that bougie-guided insertion of the ProSeal laryngeal mask airway (ProSeal LMA) has higher success rate than the digital technique in children.

METHODS

One hundred and twenty children (ASA I-II, aged 1-16 yr) were randomly allocated for ProSeal LMA insertion using the digital or bougie-guided technique. The digital technique was performed according to the manufacturer's instructions. The bougie-guided technique involved priming the drain tube with a bougie, placing the bougie in the oesophagus under direct vision and railroading the ProSeal LMA into position. Unblinded data were collected about ease of insertion (number of attempts and time taken to provide an effective airway), efficacy of seal, ease of gastric tube placement, haemodynamic responses and blood staining. Blinded data were collected about postoperative airway morbidity.

RESULTS

The first attempt success rate was higher for the bougie-guided technique (59/60 vs 52/60, P=0.015), but effective airway time was longer (37 vs 32 s, P<0.001). There were no differences in efficacy of seal, ease of gastric tube placement, haemodynamic responses, blood staining or postoperative airway morbidity.

CONCLUSION

We conclude that bougie-guided insertion of the ProSeal LMA has a higher first attempt success rate than the digital technique in children.

Cadmium hyperaccumulation and reproductive traits in natural Thlaspi caerulescens populations

During the last decade, the metal hyperaccumulating plants have attracted considerable attention because of their potential use in decontamination of heavy metal contaminated soils. However, in most species, little is known regarding the function, the ecological and the evolutionary significances of hyperaccumulation. In our study, we investigated the parameters influencing the Cd concentration in plants as well as the biological implications of Cd hyperaccumulation in nine natural populations of Thlaspi caerulescens. First, we showed that Cd concentration in the plant was positively correlated with plant Zn, Fe, and Cu concentrations. This suggested that the physiological and/or molecular mechanisms for uptake, transport and/or accumulation of these four heavy metals interact with each other. Second, we specified a measure of Cd hyperaccumulation capacity by populations and showed that T. caerulescens plants originating from populations with high Cd hyperaccumulation capacity had better growth, by developing more and bigger leaves, taller stems, and produced more fruits and heavier seeds. These results suggest a tolerance/disposal role of Cd hyperaccumulation in this species.

Maskenbeatmung als Rückzugsstrategie zur endotrachealen Intubation

The goal of ventilation in an unprotected airway is to optimize oxygenation and carbon dioxide elimination of the patient. This can be achieved with techniques such as mouth-to-mouth ventilation, but preferably with bag-valve-mask ventilation. Securing the airway with an endotracheal tube is the gold standard, but excellent success in emergency airway management depends on initial training, retraining, and actual frequency of a given procedure in the routine. "Patients do not die from failure to intubate; they die from failure to stop trying to intubate or from undiagnosed oesophageal intubation" (Scott 1986). Therefore, adequate face mask ventilation has absolute priority in airway management by an unexperienced rescuer. During ventilation of an unprotected airway, stomach inflation and subsequent severe complications may result. Careful ventilation can be performed with low inspiratory pressure and flow, and subsequently with a low tidal volume at a high inspiratory fraction of oxygen. This could be a strategy to achieve more patient safety.

Primary Burkitt lymphoma of the uterine corpus

This study reports the first well-documented case of sporadic Burkitt lymphoma arising in and confined to the uterine corpus in a 40-year-old woman who presented with vaginal bleeding. Endometrial curettings showed a diffuse infiltrate of medium sized lymphocytes with the characteristic morphologic and immunophenotypic features of Burkitt lymphoma. Fluorescence in-situ hybridization demonstrated the t(8;14)(q24;q32) translocation. There was no evidence of extra-uterine disease and the patient is alive without disease 10 months after hysterectomy and chemotherapy. This report demonstrates that Burkitt lymphoma can present as isolated, organ confined disease at unusual sites and with protean symptoms.

Pressure support ventilation with the ProSeal laryngeal mask airway. A comparison of sevoflurane, isoflurane and propofol

BACKGROUND AND OBJECTIVE

There are no data about the influence of anaesthetics on cardiovascular variables during pressure support ventilation of the lungs through the laryngeal mask airway. We compared propofol, sevoflurane and isoflurane for maintenance of anaesthesia with the ProSeal laryngeal mask airway during pressure support ventilation.

METHODS

Sixty healthy adults undergoing peripheral musculo-skeletal surgery were randomized for maintenance with sevoflurane end-tidal 2%, isoflurane end-tidal 1.1% or propofol 6 mg kg(-1) h(-1) in oxygen 33% and air. Pressure support ventilation comprised positive end-expiratory pressure set at 5 cmH2O, and pressure support set 5 cmH2O above positive end-expiratory pressure. Pressure support was initiated when inspiration produced a 2 cmH2O reduction in airway pressure. A blinded observer recorded cardiorespiratory variables (heart rate, mean blood pressure, oxygen saturation, airway occlusion pressure, respiratory rate, expired tidal volume, expired minute volume and end-tidal CO2), adverse events and emergence times.

RESULTS

Respiratory rate and minute volume were 10-21% lower, and end-tidal CO2 6-11% higher with the propofol group compared with the sevoflurane or isoflurane groups, but otherwise cardiorespiratory variables were similar among groups. No adverse events occurred in any group. Emergence times were longer with the propofol group compared with the sevoflurane or isoflurane groups (10 vs. 7 vs. 7 min).

CONCLUSION

Lung ventilation is less effective and emergence times are longer with propofol than sevoflurane or isoflurane for maintenance of anaesthesia during pressure support ventilation with the ProSeal laryngeal mask airway. However, these differences are small and of doubtful clinical importance.

Right spatial neglect after left hemisphere stroke: qualitative and quantitative study

OBJECTIVES

Comparatively little research has been conducted on right neglect after left brain damage. The authors sought to assess contralateral neglect in subacute left hemisphere stroke patients using a comprehensive test battery validated in a large control group after right hemisphere stroke.

METHODS

Seventy-eight left hemisphere stroke patients were assessed. The test battery included a preliminary assessment of anosognosia and visual extinction, a clinical assessment of gaze orientation and personal neglect, and paper-and-pencil tests of spatial neglect in the peripersonal space. Only nonverbal tests were used.

RESULTS

Drawing and cancellation tasks revealed neglect in 10 to 13% of patients. The combined battery was more sensitive than any single test alone. A total of 43.5% of patients showed some degree of neglect on at least one measure. Anatomic analyses showed that neglect was more common and severe when the posterior association cortex was damaged.

CONCLUSIONS

The frequency of occurrence of right neglect was, as expected, much lower than that reported in a study using the same assessment battery in right brain damage stroke patients. Nevertheless, neglect was found in a substantial proportion of patients at a subacute stage, suggesting that it should be considered in the rehabilitation planning of left brain damage stroke patients.

Lingual nerve injury associated with the ProSeal laryngeal mask airway: a case report and review of the literature

We present a case of lingual nerve injury that was associated with use of the ProSeal laryngeal mask airway during shoulder replacement in a 61-yr-old male. We also review other cases of cranial nerve injury, most of which were associated with use of the classic laryngeal mask airway. In principle, the frequency of cranial nerve injuries can be reduced by avoiding insertion trauma, using appropriate sizes, minimizing cuff volume, and early identification and correction of malposition.

Repeat autoclaving does not remove protein deposits from the classic laryngeal mask airway

INTRODUCTION

We tested the hypothesis that repeated autoclaving removes protein deposits from the classic laryngeal mask airway (LMA).

METHODS

Twenty previously used LMAs were hand washed, machine washed, dried, autoclaved and randomly allocated into four equal-sized groups for repeat autoclaving on 0 (control), 1, 2 and 3 occasions. After the final autoclave cycle, the LMAs were immersed in a protein-staining solution, rinsed, dried and a high-resolution digital image taken of the dorsal and ventral surfaces. The severity of staining was scored by two blinded observers.

RESULTS

All LMAs were stained. There was no reduction in staining with repeat autoclaving.

CONCLUSIONS

Repeat autoclaving does not remove protein deposits from the LMA.

Incidence of lower thoracic ligamentum flavum midline gaps † †Presented in abstract form at the IARS 78th Clinical and Scientific Congress, Tampa Bay, Florida, USA, 2004

BACKGROUND

Lower thoracic epidural anaesthesia and analgesia (EDA) has gained increasing importance in perioperative pain therapy. The loss-of-resistance technique used to identify the epidural space is thought to rely on the penetration of the ligamentum flavum. Investigations at the cervical and lumbar regions have demonstrated that the ligamentum flavum frequently exhibits incomplete fusion at different vertebral levels. Therefore, the aim of this study was to directly investigate the incidence of lower thoracic ligamentum flavum midline gaps in embalmed cadavers.

METHODS

Vertebral column specimens were obtained from 47 human cadavers. Ligamentum flavum midline gaps were recorded between the vertebral levels T6 and L1.

RESULTS

The incidence of midline gaps/number of viable specimens at the following levels was: T6-7: 2/45 (4.4%), T7-8: 1/47 (2.1%), T8-9: 2/45 (4.4%), T9-10: 7/39 (17.9%), T10-11: 12/34 (35.2%), T11-12: 10/35 (28.5%), T12/L1: 6/38 (15.8%).

CONCLUSIONS

In the present study we have determined the frequency of lower thoracic ligamentum flavum midline gaps. Gaps are less frequent than at cervical levels, but more frequent than at lumbar levels. Peak incidence was found in the region between T10 and T12. Using a strict midline approach, one cannot therefore rely on the ligamentum flavum to impede entering the epidural space in all patients.