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Biomedical subjects

W Wagner

Publications and source records attributed to W Wagner.

At least 199 records · Page 11Linked to original sources
PubMed1990

[Axillary blockade of the brachial plexus using 60 ml prilocaine 0.5% vs. 40 ml prilocaine 1%. A clinical study of 144 patients carried out by the determination of the prilocaine concentration in the central venous blood and by the measurement of the subfascial pressure in the plexus following the injection].

We estimated in this study the efficacy of axillary plexus blockade with 60 ml prilocaine 0.5% (300 mg). Following electrostimulation of the median, radial or ulnar nerve (depending on the area of the hand to be operated on), we injected prilocaine in two groups of patients (large volume group, 60 ml prilocaine 0.5% in 20 s; n = 114 patients; normal volume group, 40 ml prilocaine 1% in 20 s; n = 30 patients). Anesthesia of the median and ulnar nerves was virtually complete in all patients, but anesthesia of the radial and musculocutaneous nerves was complete in only 67% (radial) and 75% (musculocutaneous) in the group with normal injection volume. The injection of a larger volume but a lower concentration of prilocaine (300 mg) achieved better anesthesia of the radial (81%) and musculocutaneous (92%) nerves by 30-60 min after the injection. This difference was significant (p less than 0.05). The measurement of higher subfascial pressure in the axillary plexus following the larger volume of 60 ml than after 40 ml could explain the improved efficacy in overcoming anatomical hindrances in the plexus space. Estimation of the prilocaine concentration in the central venous blood 120 min after injection did not reveal different plasma concentrations in the two groups. The plasma concentrations were far below toxic levels. Only the time of plasma peak was earlier in the group with the larger volume, which was attributed to the larger area of diffusion of the vascular system in the plexus space.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

In vitro and in vivo comparative colonization of Staphylococcus aureus and Staphylococcus epidermidis on orthopaedic implant materials.

Clinically, Staphylococcus aureus appears to be the dominant organism associated with infected metal implants, whereas coagulase-negative staphylococcal strains are more frequently isolated from infected polymer implants. We reproduced this trend experimentally in vitro and in vivo. Discs of a titanium alloy, poly(methyl methacrylate) and ultra-high molecular weight polyethylene were exposed to a clinical isolate of Staphylococcus aureus or either of two strains of Staphylococcus epidermidis. Within 1 h Staphylococcus aureus was always the most rapid colonizer regardless of biomaterial. However, after 8 to 24 h, Staphylococcus aureus was present in higher numbers on metal and Staphylococcus epidermidis on polymers. Moreover, the exopolysaccharide produced by Staphylococcus epidermidis appeared to offer an effective protection against host defences in vivo.

Alloys↗
PubMed1989

Findings significant with respect to short- and medium-term outcome in schizophrenia--a preliminary report.

1. The objective of the study was to determine the relationship of psychopathological, psychobiological, and clinical psychological variables to short- and medium-term outcome in schizophrenia. 2. The predictive power of several variables described as potential predictors in the literature were evaluated. To these we added clinical psychological variables; most of these had never been examined in a prospective study. 3. The sample consisted of a total of 45 patients. None of the patients was on medication and all were tested shortly after admission to the hospital. The following factors were regarded as outcome criteria: change in the GAS-score four weeks after admission, length of hospitalization after index admission, relapse nine months after admission and two years after discharge. 4. We found that the psychobiological data set as well as the clinical psychological data set had the highest predictive power with respect to short- and medium-term outcome. 5. An analysis of the single variables within the clinical psychological data set revealed that the patients with attention disorder and a low Stimulus Barrier Function (Bellak-scale) responded better to a four-week Haloperidol treatment. Patients with a low Stimulus Barrier Function at admission had, in comparison to this, a poor outcome after two years (relapse). (No patient was taking drugs regularly at this time.) The expressed emotion of the relative approached only significance (p less than .07) as a factor to be connected with relapse after two years. 6. As psychological factors the ANS activity and the CT were measured. The latter in order to evaluate possible atrophic alterations in the brain. 7. Higher activity of the ANS was found in those patients who were hospitalized for a longer period. Slight atrophic alterations of the brain (CT scan) were related to poor outcome after two years (relapse). 8. No significant relationship was found between the psychopathological state at admission and short- or medium-term course of the illness. 9. The findings are interpreted as showing the importance of psychobiological as well as clinical psychological variables in order to uncover the factors related to the heterogeneous course of the schizophrenic illness.

Emotions↗
PubMed1989

Contact urticaria and anaphylaxis to latex.

Contact urticaria and anaphylaxis to latex is reported in two patients. One case was associated with oral and vaginal exposure to a condom and the other with rectal exposure to a latex glove. Both patients had positive reactions to scratch or prick tests to pieces of latex, as well as latex radioallergosorbent test (RAST). The diagnosis of contact urticaria to latex is difficult to make on the basis of history alone.

Anaphylaxis↗
PubMed1989

Pore formation by the Escherichia coli hemolysin: evidence for an association-dissociation equilibrium of the pore-forming aggregates.

Lipid bilayer experiments were performed in the presence of hemolysin of Escherichia coli. The toxin had a rather low activity in membranes formed of pure lipids, such as phosphatidylcholine or phosphatidylserine. In membranes from asolectin, a crude lipid mixture from soybean, hemolysin was able to increase the conductance by many orders of magnitude in a steep concentration-dependent fashion, which suggested that several hemolysin molecules could be involved in the conductive unit. Furthermore, the much higher toxin activity in asolectin membranes would be consistent with the assumption that this lipid contains a receptor needed for membrane activity of the toxin. The results of single-channel records showed that the membrane activity of hemolysin is due to the formation of ion-permeable channels with a single-channel conductance of about 500 pS in 0.15 M KCl. The hemolysin channel seemed to be formed by a toxin oligomer which showed an association-dissociation reaction and had a mean lifetime of about 2 s at small transmembrane voltages. The conductance of the hemolysin channels was only moderately dependent on the salt concentration in the aqueous phase. Zero-current membrane potential experiments showed that the hemolysin channel is cation selective. The mobility sequence of the cations in the channel was similar to their mobility sequence in the aqueous phase, which was consistent with the assumption that the hemolysin channel is wide and that the interior field strength is not very high. From the single-channel conductance, a lower limit of about 1.0 nm for the effective channel diameter could be estimated.

Cations, Monovalent↗
PubMed1989

Almitrine decreases the distensibility of the large pulmonary arteries in man.

Almitrine improves blood gas values in patients with COPD, primarily through better ventilation-perfusion matching. The improvement comes largely from a vasomotor effect of the drug. The vasomotor mechanism is unknown. We suspected that decreased distensibility of the large pulmonary arteries was one probable effect of the drug. If present, reduced distensibility would explain many of the hemodynamic alterations produced by almitrine. To test this idea, we measured the diameter of the right pulmonary artery during systole and diastole both before and after almitrine administration in nine patients who were undergoing pulmonary cineangiography. Our calculations of the distensibility of the right pulmonary artery showed that almitrine caused a 60 percent decrease. This significant alteration in the stiffness of the large pulmonary arteries can account for the rise in systolic pressure, a change that would be expected to redistribute pulmonary blood flow upwards and thereby improve ventilation-perfusion balance.

Adult↗
PubMed1989

Effects of extracellular slime produced by Staphylococcus epidermidis on oxidative responses of rabbit alveolar macrophages.

Bacterial slime produced in mass cultures of the RP 12 strain of Staphylococcus epidermidis was extracted with 4 M guanidine-HCl plus 0.05 M sodium acetate and 0.5% CHAPS, concentrated, dialyzed, and subjected to separation on DEAE sephacel columns. Three fractions, I-2A, I-2B, and I-4, were eluted with linear gradients of NaCl. Fractions I-2A and I-2B were alcian blue positive, whereas I-4 was alcian blue negative but the most electronegative fraction. The crude polysaccharide fraction and the three purified fractions were incubated individually for 2.5 or 20 h with normal rabbit alveolar macrophages (AM) to determine their effect on a subsequent PMA-induced oxidative burst. The crude fraction (50-200 micrograms/mL) and I-2B (50-200 micrograms/mL) primed the AM to give approximately a threefold increase in the PMA-induced burst after 2.5 h incubation. In contrast, a 20-h incubation resulted in a 30-40% inhibition of the PMA-induced burst with AM incubated with the same concentrations of the crude, I-2A, or I-2B fractions. Fraction I-4 had no detectable effect. The fractions also were tested to determine if they could elicit an oxidative burst in BCG-immune AM. None of the fractions (up to 500 micrograms/mL) elicited a significant oxidative burst even though BCG-immune AM yielded a PMA-induced burst 100 times that observed with normal resident AM. These data suggest that slime from S. epidermidis can impair the PMA-induced oxidative burst of normal AM during a 20-h incubation period and could explain in part why host defenses are compromised by slime-producing S. epidermidis.

Animals↗
PubMed1989

[Physiologic occupational study of changing technologies in refuse collection].

The strain on drivers and on driver's mates was investigated while emptying 1.1 m(3) containers by means of new dust compressing vehicles, and while removing dustbins of 2201 capacity. A classification was made on the basis of heart rates sampled during the whole shift by portable memories. Extrapolating for the whole shift, the authors measured heart rates of 106.0 min(-1) (drivers) from the 2201 technology. The complementary values from the 1.1 m(3) technology were 107.7 min(-1) (driver's mates) and 105.2 min(-1) (drivers). The men's physical endurance limit would be exceeded when they handled dustbins without break. The investigated tasks are classified to be heavy in both technologies.

Adult↗
PubMed1989

[Surgical intervention in stenoses and aneurysms of the renal artery].

Corrective vascular surgery was performed on 36 patients with renovascular hypertension and one patient with normal tension for 38 defective renal arteries, among them 58 per cent with arteriosclerosis and 35 per cent with fibromuscular dysplasia, in Jena, between 1969 and 1985. Follow-up checks were conducted six years from the operations (average) and revealed three major long-time results: Average blood pressure had declined from 211/121 mm Hg preoperatively to 152/95 mm Hg postoperatively. Renal functions were stabilised. Necessary antihypertensive medication could be reduced to 42 per cent of the preoperative values. Three revascularised kidneys had to be surgically removed in a second session. Four patients had died, the grey figure being one. Restenosation was recorded from three of 28 morphologically assessed arteries. Aneurysmal dilatation of a bridging graft was recorded in one case. Revascularisation proved necessary in another two. The point can be made that in cases of reno-arterial stenosis corrective vascular surgery has continued to be a valid therapeutic concept, adequate indication provided. It still is a real alternative to percutaneous transluminal angioplasty, nephrectomy or isolated therapeutic medication.

Adolescent↗
PubMed1989

[Long-term results following femoro-popliteal vascular reconstruction].

All in all, 330 thromboendarterectomies (TEA) and 354 venous bypass operations (VBP) were performed on 550 patients. In 11.01 per cent of all cases in which VBP had been planned, veins were not in optimum condition. Repetitive interventions had to be applied to 111 patients. Successful reoperations could be performed on six cases with immediate TEA-closures (1.8 per cent) and another two after immediate VBP-closures (0.56 per cent). Postoperative lethality figures were 0.6 per cent after TEA and 0.28 per cent following VBP. Twenty-nine early TEA-closures (8.9 per cent) were corrected by secondary VBP in 16 cases (4.8 per cent). Three were corrected by femoral ablation and two by toe amputation in the border zone (1.7 per cent). Thirty-nine early VBP-closures (11.0 per cent) required repetitive VBP in two cases (0.5 per cent) and toe amputation in the border zone in another three instances (0.84 per cent). Eight patients each died within the first postoperative year from TEA (2.4 per cent) and after VBP (2.2 per cent). The following cumulative patency rates were recorded according to the life table method: after one year (TEA: 90.9 per cent, VBP: 88.9 per cent), after five years (TEA: 73.4 per cent, VBP: 84.6 per cent), after ten years (TEA: 38.2 per cent, VBP: 73.7 per cent), after 15 years (TEA: 9.8 per cent, VBP: 24.2 per cent). These differences were significant as early as five years from surgery. Late amputation rates were 2.1 per cent for TEA and 2.9 per cent for VBP. Late lethality rates were 28.8 per cent for TEA and 7.6 per cent for VBP.

Adult↗