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Biomedical subjects

M Vogel

Publications and source records attributed to M Vogel.

At least 289 records · Page 16Linked to original sources
PubMed1990

[Ablation of the trabecular meshwork].

In an experimental investigation we examined the possibility to create an open pathway between the anterior chamber and Schlemm's canal by excimer laser ablation of the trabecualr meshwork (AT) in enucleated eyes. A quartzfiber was directed through the anterior chamber to the opposite chamber angle. With an energy of 0.3-1.5 mJ and wavelengths of 248 and 308 nm pores were easily made into the trabecular meshwork leading to a direct connection between the anterior chamber and Schlemm's canal. This result was confirmed by histologic examination of the globes. The trabecular meshwork has disappeared completely. The surrounding tissue reveals only minimal thermal effects due to the laser burns. With the same method cyclodialysis and basal iridectomy may be performed. The operation is simple and effects can be placed with great accuracy.

Animals↗
PubMed1990

Humoral and cellular immune response in mice and dogs induced by a recombinant Echinococcus multilocularis antigen produced by a Salmonella typhimurium vaccine strain.

A gene fragment (II/3-10) from the cestode Echinococcus multilocularis coding for a species-specific antigen was expressed in the live attenuated Salmonella typhimurium vaccine strain LT2 M1C. The recombinant vaccine (S. typhimurium + pVM II/3-10) was assessed for its potential to induce both a humoral and cell-mediated immune response in mice and dogs. Both subcutaneous and peroral administration of the vaccine resulted in antibody synthesis and lymphocyte priming of C57BL/6J mice against S. typhimurium antigens as well as against the recombinant E. multilocularis antigen. Two vaccinated (subcutaneous and peroral) dogs showed a strong humoral immune response to S. typhimurium antigens and to the recombinant E. multilocularis antigen, but proliferation of peripheral blood lymphocytes was not detectable against the bacterial S. typhimurium antigens. Regarding the recombinant E. multilocularis antigen, borderline lymphocyte proliferation was demonstrated following subcutaneous and none following peroral administration of the recombinant vaccine to dogs.

Animals↗
PubMed1990

[Comparison of extracapsular cataract extraction with implantation of the artificial lens into the posterior chamber and intracapsular cataract extraction with implantation of the artificial lens into the anterior chamber].

Advantages and disadvantages of both methods are presented on the basis of comparison of 1200 cases of intracapsular cataract extraction with anterior chamber lens implantation and 600 cases of extracapsular cataract extraction with implantation of posterior chamber lens. One has to state that in general the preferential method of extracapsular cataract extraction with posterior lens implantation is connected with several complications. The main disadvantage of intracapsular cataract extraction with anterior chamber implantation is--in 66 p.c.--deformation of the pupil. From our point of view this is a problem of cosmetic nature. On the basis of comparison of disadvantages and advantages we are of opinion that both methods are equally suitable for a broad clinical use.

Anterior Chamber↗
PubMed1990

In vitro activities of seven quinolone derivatives against Neisseria gonorrhoeae.

The in vitro activities of ciprofloxacin, enoxacin, fleroxacin, lomefloxacin, norfloxacin, ofloxacin, and pefloxacin against 10 penicillinase-producing N. gonorrhoeae strains (PPNG's), 10 non-PPNG's, 10 non-penicillinase-producing penicillin-resistant chromosomally mediated N. gonorrhoeae strains (CMRNG's) 3 N. gonorrhoeae strains with a decreased sensitivity against quinolones compounds and one tetracycline-resistant penicillinase-producing N. gonorrhoeae (TRNG/PPNG), strain were evaluated in this study. The non PPNG, PPNG, CMRNG and TRNG/PPNG strains showed good to excellent sensitivity to the quinolones tested. The N. gonorrhoeae strains with a decreased sensitivity against quinolones showed higher MIC (minimum inhibitory concentration) values.

4-Quinolones↗
PubMed1990

[Retinal periphlebitis and multiple sclerosis. Incidence, cerebrospinal fluid and results of visual evoked potentials].

In a retrospective study 323 patients with multiple sclerosis were screened for the incidence of retinal periphlebitis. The results of lumbar puncture and the visual evoked potentials were related to the eye disease. Retinal periphlebitis was seen in 19 patients (5.9%). Of the patients with retinal periphlebitis, 79% developed the eye pathology within the first 10 years of multiple sclerosis. The cerebrospinal fluid and visual evoked potentials were no different than the results in a control group of multiple sclerosis patients without periphlebitis. Multiple sclerosis should always be considered as one of the potential underlying diseases in retinal periphlebitis since it is found in 30% before or at the same time as the first neurological symptoms of multiple sclerosis.

Adult↗
PubMed1990

[Fatal outcome in HELLP syndrome].

The patient was a 32-year-old para 2 who developed within a few hours after the first symptoms a lethal HELLP-syndrome. Despite initially normal blood pressure an hepatic failure, hemolysis and cerebral bleeding appeared. The autopsy revealed an eclamptic liver and symptoms of a disseminated intravasal coagulation (DIC). As a consequence a quick delivery instead of a conservative-expectant management because of fetal prematurity is recommended.

Adult↗
PubMed1989

Prostaglandin E2 in the lung lavage fluid of premature newborns before and after surgical or medical closure of a patent ductus arteriosus.

To analyze the role of prostaglandin E2 in maintaining ductal patency in premature newborns, we measured the PGE2 concentration in the lung lavage fluid of nine patients within 24 h before and 4-8 h after surgical ligation of a patent ductus arteriosus and in two patients before and after closure of the ductus following intravenous indomethacin. The concentration of PGE2 ranged from 240 to 3770 pg/ml (mean 1666 +/- 1256 pg/ml) before operative intervention and show a significant decrease to 0-300 pg/ml (mean 93 +/- 106 pg/ml, P less than 0.001, Student's two-tailed t-test) within a few hours after ligation of the ductus arteriosus. The same significant decrease could be seen in two patients with successful indomethacin therapy (0.25 mg/kg in three doses/day) with concomitant ductus closure. In contrast, when indomethacin was given in a reduced dose (0.1 mg/kg in three doses/day), only a slight effect on PGE2 synthesis could be seen without closure of ductus arteriosus. We suggest that the fall of PGE2 levels in lung lavage fluid reflects the local synthesis in the ductus arteriosus itself and is responsible for the decrease induced by surgical ligation or pharmacological inhibition by indomethacin.

Bronchoalveolar Lavage Fluid↗
PubMed1989

Plasmid vector for overproduction and export of recombinant protein in Escherichia coli: efficient one-step purification of a recombinant antigen from Echinococcus multilocularis (Cestoda).

We describe the use of the Escherichia coli plasmid vector, pVB2, for high-level expression and export of recombinant protein. The pBR322 derivative pVB2 harbors the mglB gene, which codes for the galactose-binding protein (GBP) of E. coli. GBP is exported into the periplasmic space of the bacterial cell. Gene mglB contains an EcoRI restriction site close to its 3' end which allows simple in-frame insertion of EcoRI fragments obtained from recombinant lambda gt11 phages. The pVB2 vector was used to express an antigen from Echinococcus multilocularis. The recombinant protein amounted to over 50% of total cellular protein and could be efficiently isolated from the periplasm by osmotic shock. The application of the purified antigen in an ELISA enabled a clear and specific detection of anti-Ec. multilocularis antibodies in human patients' sera, which had been immunosorbed with a periplasmic extract (containing wt GBP) before investigation. These data show the general usefulness of pVB2 as an expression vector for producing in E. coli diagnostically relevant antigens from any infective organism.

Animals↗
PubMed1989

Wave-guide spectroscopy on planar lipid bilayers doped with hydrophobic ions.

Wave-guide spectroscopy exploits the light pipe properties of planar lipid bilayers by propagating a light wave along the plane of the bilayer. Applying this technique to the optical absorption of chromophore in the membrane, results in an enhanced sensitivity when compared to normal incidence spectroscopy. This gain factor is of the order of 100 per mm optical path along the bilayer, thus transforming the weak absorbances in lipid membranes into easily measurable quantities. Wave-guide spectroscopy has been used to measure the adsorption isotherm of hydrophobic dipicrylamine ions in a phosphatidylcholine membrane. The adsorption isotherm is linear for low aqueous concentrations, in the micromolar range however, it changes into a sublinear dependence. The addition of an inert alkali salt to the electrolyte favours the adsorption of hydrophobic ions. Current saturation is observed with the transition to the sublinear isotherm. When using the time constant for current relaxation as an indicator of changes in the magnitude of the surface potential, it does not seem to vary with the additional dipicrylamine which adsorbs in the presence of high concentrations of alkali salt in the electrolyte. A compensation of hydrophobic charge by the alkali ions from the inert electrolyte is proposed.

Algorithms↗
PubMed1989

The predictive value of chorionic villus histology for identifying chromosomally normal and abnormal spontaneous abortions.

To evaluate the significance of placental histology, a collaborative histological and cytogenetic study on the products of 123 spontaneous abortions of 6-19 week pregnancies was performed. From each sample, 2-3 g was dissected randomly and analysed histologically with no prior knowledge of the karyotype. Chromosomes were prepared from the remaining chorionic villi after an overnight incubation in culture medium; they were analysed by Q- or G-banding. The frequency and type of chromosome anomalies detected are comparable to those seen in other studies. Altogether, 49.6% were chromosomally abnormal, trisomies predominating (49.2%), followed by polyploidy (27.9%) and monosomy X (14.5%). The histological classification failed for technical reasons in 11 cases (8.9%). To classify the remaining cases, 18 different histological criteria were considered independently by two pathologists. A definite diagnosis was not possible for 27 abortions (22.0%), and 50 were classified as being chromosomally abnormal. This proved to be correct in 36 (72.0%), but incorrect in as many as 14 (28.0%). No evidence for an abnormal karyotype was found histologically in samples from 35 abortuses. Nevertheless, 9 of them (25.7%) had an abnormal karyotype. The predictive value of chorionic villus histology seems to be inadequate, as only 62 of 112 samples were correctly classified by histology (55.4%). The value differs little from the a priori probability of an abnormal or normal karyotype in abortuses of corresponding gestational ages.

Abortion, Spontaneous↗
PubMed1989

Animal experiments for the determination of an optimal wavelength for retinal coagulations.

The retina of rabbits was coagulated with different wave-lengths (570-630 nm) using a tunable dye laser with Rhodamin 6G. To achieve comparable ophthalmoscopic appearance the intensity of the laser beam was varied with neutral filters of varying absorption. Histologic examination of fresh coagulation effects and 3-week-old coagulation scars showed no difference in relation to the wave-length used. Theoretically, 577 nm seems to be a particularly useful wavelength for the treatment of a wide variety of retinal lesions because it is not absorbed in xanthophyll and penetrates opacities of the optic media better than argon blue green. Furthermore, it is absorbed maximally in hemoglobin, making it particularly suitable for the coagulation of blood vessels.

Animals↗
PubMed1989

Application of a recombinant Echinococcus multilocularis antigen in an enzyme-linked immunosorbent assay for immunodiagnosis of human alveolar echinococcosis.

A highly antigenic polypeptide fragment of the recombinant Echinococcus multilocularis antigen II/3 was produced in Escherichia coli and purified for application in enzyme-linked immunosorbent assay (ELISA). The antigen II/3-encoding 1.0 kb DNA sequence was reduced by sonication into smaller DNA fragments which were subsequently cloned into lambda gt11. Three clones could be isolated from the sublibrary, all synthesizing a recombinant antigen as a stable beta-galactosidase fusion protein. In a further step, the 0.6-kb insert from one positive clone was subcloned into the plasmid pAR 3038, which directed efficient synthesis of the antigen fused to only 11 amino acids from the N-terminus of the phage T7 major capsid protein. The plasmid-encoded antigen (antigen II/3-10) was purified from a bacterial cell extract and then tested in an ELISA. Using sera from 88 patients with an E. multilocularis-infection, a high diagnostic sensitivity of 90% was demonstrated. Investigation of sera from 220 patients with various helminthic infections showed a specificity of 99%, suggesting the suitability of the antigen II/3-10 as an immunodiagnostic tool.

Animals↗
PubMed1989

[Classification and importance of cystoid macular edema in pseudophakia].

In a prospective study the authors attempted to establish the incidence of cystoid macular edema (CME) in uncomplicated intracapsular cataract extraction with implantation of Choyce Mark IX lenses. Fluorescein angiography was performed after eight days, six weeks, six months, and at least one year post-operatively. Any edema found was classified as Grade I to III. Grade III CME was demonstrated in 4% of the cases studied after six weeks, though not after six months or one year, respectively. After one year, Grade II was found in 2% and Grade I in 15%, respectively. However, visual function was not impaired. At no time was there any correlation between the severity of the macular edema and visual acuity: all combinations are possible. Grade III CME evidently only impairs visual function if it persists for a prolonged period of time. Hyperfluorescence in the late phase of the angiogram permits the breakdown of the blood-aqueous barrier to be estimated semi-quantitatively.

Aged↗
PubMed1989

[Tuberculosis of the conjunctiva and eyelids].

A diagnosis of unilateral tuberculosis of the conjunctiva was established in a 75-year-old female patient eight years after the first manifestations of disease. It was clearly a case of exogenous infection. Generalized infection only became apparent months after the bulb had been removed together with the lids and the anterior portions of the orbital tissue.

Aged↗
PubMed1989

The efficacy of the combination of teicoplanin or flucloxacillin with netilmicin in the treatment of Staphylococcus aureus bacteraemia.

Twenty one patients with serious Staphylococcus aureus infection and bacteraemia were randomized prospectively to receive either teicoplanin and netilmicin or flucloxacillin and netilmicin. After at least 48 h of treatment serum samples were collected for the determination of trough and peak antibiotic concentrations, the serum killing level and the serum bactericidal rate. With the help of a severity-of-disease scoring system (APACHE II) the clinical efficacy of antimicrobial therapy was assessed. Eighteen patients were evaluable. The clinical results and the results of the serum assays suggest that treatment with teicoplanin or flucloxacillin, combined with netilmicin, is a safe approach in patients with bacteraemia caused by S. aureus.

Adult↗
PubMed1989

Balloon dilatation of congenital aortic valve stenosis in infants and children: short term and intermediate results.

Percutaneous balloon dilatation of the aortic valve was attempted in 25 consecutive patients with stenosis. The aortic valve diameters were normal for age. The balloon catheters were placed retrogradely, and their diameters were within 1-2 mm of the valve diameter and 3 (13 patients) or 6 cm (recent 12 patients) long. After dilatation the pressure gradients across the aortic valve were reduced significantly and the valve areas, measured in 10 patients, increased. Aortic regurgitation was detected in six patients before (grade I) the procedure and in 15 patients (6 grade I, 6 grade II, 3 grade III) after the procedure. In one patient the aortic valve could not be crossed and in three there was no reduction in the pressure drop. Nine patients have a sustained reduction in Doppler assessed gradients. There were vascular complications in 12 and these required surgical intervention in three patients. Balloon dilatation seems to be an effective short term palliative procedure in patients with congenital stenosis of the aortic valve.

Adolescent↗