A novel suture method to place and adjust peripheral nerve catheters

We have developed a peripheral nerve catheter, attached to a needle, which works like an adjustable suture. We used in‐plane ultrasound guidance to place 45 catheters close to the femoral, saphenous, sciatic and distal tibial nerves in cadaver legs. We displaced catheters after their initial placement and then attempted to return them to their original positions. We used ultrasound to evaluate the initial and secondary catheter placements and the spread of injectate around the nerves. In 10 cases, we confirmed catheter position by magnetic resonance imaging. We judged 43/45 initial placements successful and 42/43 secondary placements successful by ultrasound, confirmed in 10/10 cases by magnetic resonance imaging.

Granulometry and the content of toxic and potentially toxic elements in vacuum-cleaner collected, indoor dusts of the city of Warsaw

Twenty-seven sites, together with 23 household dust sample sites, representing the home environment, and four public room dust sample sites, representing working environment (mainly offices) have been described in this paper. The latter were examined to obtain an approximate reference to the home environment data. All the samples were collected between May and July 1997 by a vacuum-cleaner method, in the city of Warsaw, Poland. The granulometry of the dusts was determined by their separation into seven fractions in the range 8-500 microm. The concentrations of Cr, Ni, Cu, Zn, Pb, Br and Fe in the samples were investigated in fractions 8-32, 32-63 and 63-125 microm by the EDXRF technique. The results showed higher concentrations of these elements in finer fractions (8-32 microm). The Pb content in the household dusts was found to be unexpectedly low, ranging from 120 microg g(-1) for the 63-125 microm fraction, up to 210 microg g(-1) for the 8-32 microm fraction. Car exhausts could not be determined clearly as the main source of Pb in the indoor household dusts due to the lack of a Pb-Br intercorrelation. In these dusts, only Cr and Zn showed a remarkably high content of 90-100 and 1020-1070 (microg g(-1)), respectively. In the household dusts, strong intercorrelations were present in the three analysed fractions for the metal pairs: Pb-Zn, Pb-Cu, Fe-Cr, and Cu-Cr (weaker). The working environment rooms showed a higher degree of dustiness by 300%, as compared to the dwellings. The dusts collected in the working environment rooms showed slightly higher concentrations of Ni and by 50-100% higher concentrations of: Cu, Zn, Pb, Br than the analysed household dusts.

Arsenic speciation in marine organisms: from the analytical methodology to the constitution of reference materials

An analytical procedure for total arsenic and arsenic species quantification in marine organisms has been developed. Fresh materials are freeze-dried and reduced to powders before analysis. Arsenic is determined either by energy dispersive X-ray fluorescence (EDXRF) directly or by inductively coupled plasma optical emission spectrometry (ICP/OES) after microwave digestion. Arsenic speciation is performed on the extracted sample using liquid chromatography coupled to ICP/OES for arsenobetaine and arsenocholine determination and to the hydride generation-quartz furnace atomic absorption spectrometric technique for arsenite, arsenate, monomethylarsonic and dimethylarsinic acids quantification. Special precautions are taken to avoid losses or contaminations as well as to prevent analytical errors during the quantification stage. Other methods are applied and the corresponding results compared for each step of the procedure. The method is finally validated by means of intercomparison studies within the Measurements and Testing Programme of the European Community (formely BCR).

Determination of total mercury in estuary, lake and river sediments

In order to improve the quality of the results in sediment analysis, the Community Bureau of Reference (BCR) of the European Communities has developed 3 sediment reference materials (CRM) from estuarine, lake and river origins. Certification of mercury content in these materials was achieved by 3 methods (cold vapor atomic absorption spectrometry, plasma emission spectrometry, neutron activation analysis with radiochemical separation). The values finally certified in the CRM estuarine, lake and river sediments are 1.77 +/- 0.06, 0.67 +/- 0.02, 1.03 +/- 0.13 mg/kg respectively.

Acute mercury chloride intoxication. Effects of hemodialysis and plasma exchange on mercury kinetic

A 27 year-old man developed after ingestion of mercury chloride, 6 g, a hypovolemic shock, an acute renal failure and a necrosis of the stomach which required a total gastrectomy. The anuria did not improve and required 42 hemodialyses. Subsequent evolution showed numerous complications and the patient died on the 91st day. On admission mercury plasma concentration was 5 mg/L and decreased slowly with an apparent half-life of 226 hours. Hemodialyses were ineffective for mercury elimination: mercury clearances varied between -10 and + 1.5 ml/min. Seventeen mg of mercury were removed by six plasma exchanges: the mercury clearance was mean 17.3 ml/min. Among the extracorporeal elimination methods, plasma exchange appears to be the most efficient for inorganic mercury and it could be usefull in association with chelation therapy at the early phase of the intoxication.

Simultaneous determination of trace elements in lavage fluids from human bronchial alveoli by energy-dispersive x-ray fluorescence. 3. Routine analysis

We applied the energy-dispersive x-ray fluorescence technique to determination of trace elements in human bronchoalveolar lavage fluids. Our analysis of more than 200 samples allowed us to determine normal reference values, to be used in characterizing occupational exposure. These values are expressed both in nanograms per 1000 cells (of all kinds) and nanograms per 1000 macrophages to correlate lavage efficiency and dust content of the alveoli. The result expressed in milligrams per liter is not sufficient, because some healthy volunteers showed high concentrations of iron but normal values when expressed vs the number of cells. Some examples of abnormal compositions of broncho-alveolar lavages are reported and the fully automated spectrometer developed for clinical and biological investigations is described.

Simultaneous determination of trace elements in lavage fluids from human bronchial alveoli by energy-dispersive x-ray fluorescence. 3. Routine analysis

We applied the energy-dispersive x-ray fluorescence technique to determination of trace elements in human bronchoalveolar lavage fluids. Our analysis of more than 200 samples allowed us to determine normal reference values, to be used in characterizing occupational exposure. These values are expressed both in nanograms per 1000 cells (of all kinds) and nanograms per 1000 macrophages to correlate lavage efficiency and dust content of the alveoli. The result expressed in milligrams per liter is not sufficient, because some healthy volunteers showed high concentrations of iron but normal values when expressed vs the number of cells. Some examples of abnormal compositions of broncho-alveolar lavages are reported and the fully automated spectrometer developed for clinical and biological investigations is described.

Simultaneous determination of trace elements in lavage fluids from human bronchial alveoli by energy-dispersive x-ray fluorescence. 2: Determination of abnormal lavage contents and verification of the results

We applied energy-dispersive x-ray fluorescence to the determination of abnormally present elements or abnormal concentrations of elements in human broncho-alveolar lavage fluids. The low detection limits and the ability to perform multi-elemental analysis permit one to establish or confirm occupational exposure of workers. We also describe different methods used to check our method and our results. We report examples of abnormal compositions of broncho-alveolar lavages containing W, Ce, La, Nd, I, Fe, or Ni. We discuss the limits of the method for characterizing silicosis or asbestosis.

Simultaneous determination of trace elements in lavage fluids from human bronchial alveoli by energy-dispersive x-ray fluorescence. 2: Determination of abnormal lavage contents and verification of the results

We applied energy-dispersive x-ray fluorescence to the determination of abnormally present elements or abnormal concentrations of elements in human broncho-alveolar lavage fluids. The low detection limits and the ability to perform multi-elemental analysis permit one to establish or confirm occupational exposure of workers. We also describe different methods used to check our method and our results. We report examples of abnormal compositions of broncho-alveolar lavages containing W, Ce, La, Nd, I, Fe, or Ni. We discuss the limits of the method for characterizing silicosis or asbestosis.

Simultaneous determination of trace elements in lavage fluids from human bronchial alveoli by energy dispersive x-ray fluorescence. 1: Technique and determination of the normal reference interval

We have applied energy dispersive x-ray fluorescence to the analysis of broncho-alveolar lavage fluids, to determine the concentration of several elements simultaneously with manipulation of the sample minimized. A 20-microL sample of a homogenized lavage fluid, to which two internal standards (containing Y and V) have been added, is deposited on a polypropylene film, 4 microns in thickness, and analyzed by x-ray fluorescence. We report the analytical procedure, the detection limits, and the reproducibility. The normal concentration range for trace elements is reported for a selected population. The simplicity and rapidity of the method, and the possibility of automating measurements, make this procedure suitable for screening large numbers of lavage specimens and to establish the diagnosis of some pneumoconioses.

Simultaneous determination of trace elements in lavage fluids from human bronchial alveoli by energy dispersive x-ray fluorescence. 1: Technique and determination of the normal reference interval

We have applied energy dispersive x-ray fluorescence to the analysis of broncho-alveolar lavage fluids, to determine the concentration of several elements simultaneously with manipulation of the sample minimized. A 20-microL sample of a homogenized lavage fluid, to which two internal standards (containing Y and V) have been added, is deposited on a polypropylene film, 4 microns in thickness, and analyzed by x-ray fluorescence. We report the analytical procedure, the detection limits, and the reproducibility. The normal concentration range for trace elements is reported for a selected population. The simplicity and rapidity of the method, and the possibility of automating measurements, make this procedure suitable for screening large numbers of lavage specimens and to establish the diagnosis of some pneumoconioses.

Simultaneous determination of trace elements in serum by energy-dispersive x-ray fluorescence spectrometry

Energy-dispersive x-ray fluorescence is applied in the analysis of human serum to determine the concentrations of several elements simultaneously with minimal manipulation of the sample. The analytical procedure has been developed with standard sera, and standardization, detection limits, and reproducibility have been established. A 50-microL sample of diluted serum, to which an internal standard has been added, is deposited on a thin (4-microns thick) polypropylene film and analyzed by x-ray fluorescence. We report the statistical distributions of the concentrations of Fe, Cu, Zn, and Br obtained in the population (103 samples) studied, and report detection limits for the other 22 elements studied. The simplicity of the method, the high throughput, and the possibility of automating the measurements make this procedure suitable for screening large numbers of sera.

Simultaneous determination of trace elements in serum by energy-dispersive x-ray fluorescence spectrometry

Energy-dispersive x-ray fluorescence is applied in the analysis of human serum to determine the concentrations of several elements simultaneously with minimal manipulation of the sample. The analytical procedure has been developed with standard sera, and standardization, detection limits, and reproducibility have been established. A 50-microL sample of diluted serum, to which an internal standard has been added, is deposited on a thin (4-microns thick) polypropylene film and analyzed by x-ray fluorescence. We report the statistical distributions of the concentrations of Fe, Cu, Zn, and Br obtained in the population (103 samples) studied, and report detection limits for the other 22 elements studied. The simplicity of the method, the high throughput, and the possibility of automating the measurements make this procedure suitable for screening large numbers of sera.

[The pulmonary toxicity of mercury vapors in the rat]

Rats have been exposed for periods of 120 to 240 minutes to an atmosphere containing 6 +/- 0.7 mg per cu.m mercury vapor. All rats developed an acute respiratory distress which lead to death within 2 to 210 hours (mean 53.5 h). Microscopical examination of the lungs showed an oedema rich in fibrin, an epithelial necrosis, hyaline membranes and in two cases an interstitial fibrosis. Mercury levels in the lungs ranged between 0.5 and 9.37 micrograms per gramme wet weight. The activity of pulmonary superoxide dismutase was decreased to 1.57 +/- 0.66 micrograms per mg of soluble proteins, compared with the level of 5.01 +/- 0.76 micrograms per mg in control rats. This study confirm the pulmonary toxicity of mercury vapors observed in human intoxication.

Epidural lipoma simulating lumbar disc protrusion

Spinal lipomata are usually associated with congenital anomalies. A lipoma, presenting with symptoms, signs and myelographic findings suggestive of a lumbar disc protrusion, is rare. Asymmetry of the origin of some of the scaral nerve roots may be the clue for suspecting epidural lipoma pre-operatively.