Search PubMed⌕ Search

Biomedical subjects

G Haase

Publications and source records attributed to G Haase.

At least 127 records · Page 7Linked to original sources
PubMed1979

Plasma-exchange combined with immunosuppressive therapy in myasthenia gravis.

Twenty-one patients with myasthenia gravis underwent a course of plasma exchange combined with immunosuppressive therapy. In fifteen there was dramatic clinical improvement which has been maintained for periods up to 19 months. Nine of these patients now take no anticholinesterase drugs. Six patients had a recurrence 3--9 months after the first course but in the three given a second course remissions were again obtained.

Adult↗
PubMed1979

[Determination and position of the masticatory surface complex and clinically necessary corrections (with special regard to Fehr's calotte articulation)].

The individual calotte articulation recommended by C. U. Fehr in 1947 has been used at the Free University of W. Berlin for clinical teaching since this time. The following studies were described and/or recalled and contrasted with other methods for determining position: 1. Studies of Grabert mandibular posture compared with the Ivo-Tray model. 2. Stoebe's studies of calottes with various radii, 3. Eichner's and Schmitthelm's roentgencinematographic studies, 4. Reese's study of biting force, 5. Husemann's comparison of different relational determinations, 6. Sauer's study of the success of reocclusion. Based on the clinical results and also the results of difficult comparative studies. we see no reason to depart from functional determination of relation using calotte-shaped, curved wax walls. Clinical example of the grinding surface complex, which is part of the method, guarantees construction of the complete denture within the range of tissue adaptation. No elaborate apparatuses are required. Even complicated tracing methods do not eliminate the possibility of additional work (e.g., removal of pressure areas, reocclusion).

Dental Impression Technique↗
PubMed1977

[Lateral teleradiographic diagnosis of deep bite].

113 lateral teleradiographs of students were analysed by A. M. Schwarz's method of X-ray analysis inorder to clarify whether the occlusal position of a patient can be determined from gnathometric data and data relating to soft parts in the lateral teleradiograph with sufficient certainty. The relatively high proportion of close bite cases (20%) enabled a comparison to be made of the measurements of anatomically correct occlusal position and close bite. The large scatter of the measurements for anatomically correct interlocking was striking. Of seven specific close bite characteristics, with anatomically correct occlusal position three at most could be identified whereas in cases of close bite, four to six occurred. So the diagnosis of "close bite" from the appearance of four or more close bite characteristics in the lateral teleradiograph seems to be confirmed.

Adult↗
PubMed1975

Multiple sclerosis-associated agent: transmission to animals and some properties of the agent.

In confirmation and extension of observations by Carp and his associates, brain tissue and sera from patients with multiple sclerosis (MS) were found to harbor an agent which induces a transitory depression in polymorphonuclear leukocytes (PMN) in mice as well as in rats, hamsters, and guinea pigs. All of eight MD brains contained this agent at titers as high as 10(-9)/g of brain tissue. The agent was found in MS sera at titers up to 10(-3)/ml of serum, but its presence depended to some extent on the clinical status of the patients; it was observed more frequently in sera of patients with active disease (73%) thatn in sera of patients with quiescent disease (31%). Control brain tissues or sera failed to induce PMN depression. The apparently MS-associated agent (MSAA) passed through 50-nm but not 25-nm membrane filters (Millipore Corp.) and was largely sedimented at 105,000 X g but not at 50,000 X g for 1 h. It multiplied to high titers in the central nervous tissue of the inoculated animals and could be serially transmitted from animal to animal by passage of brain homeganates. Various observations and considerations appear to preclude that MS-associated agent represents an indigenous animal virus. Although its role in MS remains to be determined, it should be considered a candidate for the etiology of this disease.

Animals↗
PubMed1975

Multiple sclerosis-associated agent: neutralization of the agent by human sera.

A total of 172 sera from patients with multiple sclerosis (MS), theri relatives and nursing personnel, patients with other neurological and nonneurological diseases, and healthy donors living in the United State or East Africa under vastly divergent hygienic conditions were examined for their capacity to neutralize the MS-associated agent (MSAA), which induces in experimental animals a transitory depression of circulating polymorphonuclear leukocytes (PMN). A considerable proportion of sera from MS patients and their relatives or nursing personnel and East African donors revealed neutralizing activity, but only one of 59 sera from American donors without known contacts with MS patients revealed neutralizing activity. Some of the sera could be diluted 100- or 1,000- fold and still prevent, or substantially reduce, PMN depressions in mice. The neutralizing activity was shown to be associated with the immunoglobulin fractions of sera and therefore appears to be due to an antibody. Cerebrospinal fluids from MS, but not other, patients also strongly neutralized MSAA. Evidence has been presented that sera from MS patients may contain both MSAA and MSAA neutralizing antibodies. Antigen-antibody complexes were separated from such sera by high-speed centrifugation, and neutralizing antibodies were dissociated from them at a low pH. Whereas the data are as yet limited due to the vagaries and complexities of the test procedures, they provide further evidence that MSAA is not an indigenous virus of experimental animals, causes infections in man, and is indeed closely associated with MS. If it were the cause of MS, which remains to be ascertained, the data imply that not all infections by MSAA lead to the development of MS.

Animals↗
PubMed1975

[Studies on the retention of total lower dentures in relation to the time of wearing].

Clinical experience in the prosthetical care of edentulous patients shows that primarily patients wearing dentures for the first time express the desire, after a few months, to have original denture adhesion restored. Especially for complete lower dentures diminishing adhesion is unfavorable. Measurements regarding the adhesive strength of complete lower dentures of 34 patients showed that adhesive strength is decreasing. This was measured and statistically evaluated in this investigation. 33 percent of the original adhesive strength is lost within 6 months. With originally strong adhesion (2, 000 p) this reduction is more drastic than with originally small adhesion (200 p). It was not possible to establish that adhesive strength is declining preferably as a result of a specific anatomic situation.

Denture Retention↗
PubMed1973

Solid state AgCl detectors for nuclear tracks with on- and off-response at choice: applications to life sciences.

A new concept of trackforming solid state detectors is presented. These detectors record and accumulate tracks of ionizing particles which can be revealed if they are irradiated with yellow light during the passage of the particle through the detector; otherwise the tracks are dropped by fading. Tracks stabilized by yellow light are stable for months. The detectors consist of thin layers of 200-300 micrometers of Cd-doped AgCl crystals, supported by a thin plate of quartz glass. The invisible latent tracks in these detectors are revealed at microscopically visible size by ultraviolet light. The sensitivity of the crystals against particles of different specific energy transfer depends upon the concentration of Cd; these have rather good thresholds, which permit selective recording in a well-known manner. These AgCl(Cd) crystals have a unique property amongst trackforming detectors; their response can be switched on and off at choice, for instance by electronic triggering of the stabilizing accompanying yellow light. This allows a time assignment of particle tracks, or restriction to tracks of desired particles. Examples of tracks and of applications in cosmic ray research, heavy ion physics, radiobiology and dosimetry are given.

Bacillus subtilis↗
PubMed1969

Ascorbic acid and copper in linoleate oxidation. I. Measurement of oxidation by ultraviolet spectrophotometry and the thiobarbituric acid test.

The UV absorption method and the thiobarbituric acid (TBA) test for oxidation of an aqueous suspension of linoleate were compared. The absorption method depends on the formation of hydroperoxides having conjugated double bonds that absorb strongly at 233 nm. The absorption at 233 nm increased markedly during oxidation of linoleate catalyzed by either ascorbic acid or cupric ions. The concentration of ascorbic acid in the reaction mixture was also measured by UV absorption at 265 nm and pH 7.0. Color development in the TBA test also increased markedly with the extent of oxidation of linoleate. When ascorbic acid was the catalyst, UV absorption detected early stages of oxidation with greater sensitivity than the TBA test. The reverse was true when Cu(++) was the catalyst. In general, the relation between the two procedures will depend on whether copper is present when the TBA test is made.

Alkenes↗
PubMed1969

Ascorbic acid and copper in linoleate oxidation. II. Ascorbic acid and copper as oxidation catalysts.

Both ascorbic acid and copper were strong prooxidants in the oxidation of linoleate in a buffered (pH 7.0) aqueous dispersion at 37 degrees C. Minimum concentrations at which catalytic activity was detected were 1.3 x 10(-7) m for copper and 1.8 x 10(-6) m for ascorbic acid. For concentrations up to 10(-3) m, the increase in rate of oxidation with increase in concentration of catalyst was greater for ascorbic acid than for copper. Ascorbic acid had maximum catalytic activity at 2.0 x 10(-3) m, but was still prooxidant at the highest concentration tested (5.0 x 10(-2) m). Dehydroascorbic acid was a weaker prooxidant than ascorbic acid. Further degradation products of ascorbic acid were not prooxidant. In early stages of the oxidation autocatalytic behavior was observed with copper, but not with ascorbic acid. Ascorbic acid functioned as a true catalyst, i.e., it accelerated the reaction but it was not oxidized simultaneously with the linoleate. It is proposed that the dehydroascorbic acid radical initiates the linoleate oxidation reaction.

Alkenes↗
PubMed1969

Ascorbic acid and copper in linoleate oxidation. 3. Catalysts in combination.

In promoting oxidation of 0.02 m potassium linoleate in a buffered (pH 7.0) aqueous dispersion at 37 degrees C, ascorbic acid at low concentrations (1.8 x 10(-6) and 1.8 x 10(-5) m) in combination with copper (1.3 x 10(-7) to 1.3 x 10(-3) m) had greater catalytic activity than the additive activity of the two catalysts individually. Possible explanations for the enhanced catalysis include reduction of copper by ascorbic acid to the cuprous form, increased concentration of semidehydroascorbic acid radical, and formation of a metal-ascorbic acid-oxygen complex. Some combinations of ascorbic acid (1.8 x 10(-4) and 1.8 x 10(-3) m) and copper (1.3 x 10(-6) and 1.3 x 10(-3) m) inhibited the formation of conjugated dienes but not the oxidation of ascorbic acid, and caused rapid loss of part of the conjugated dienes that were already present. It is suggested that free-radical inhibitors formed by the combination of catalysts inhibit initiation of lipid oxidation but not copper-catalyzed oxidation of ascorbic acid. Effects of the inhibitory combinations on changes in UV absorption by conjugated dienes, and absorbance in the TBA test, indicate the presence of at least two conjugated dienes that differ in stability.

Alkenes↗