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Biomedical subjects

H Brade

Publications and source records attributed to H Brade.

198 records · Page 11Linked to original sources
PubMed1983

Common lipopolysaccharide specificity: new type of antigen residing in the inner core region of S- and R-form lipopolysaccharides from different families of gram-negative bacteria.

A new antigenic specificity, referred to here as common lipopolysaccharide (LPS) specificity, is described in the LPSs of gram-negative bacteria belonging to various families. The specificity is present in S- and R-form LPS but absent in Re mutants of different enterobacterial genera. By the use of purified LPS and monospecific antibodies obtained by immunoabsorption, the specificity is differentiated from the known core specificities of the genus Salmonella and the lipid A specificity by aid of the passive hemolysis and passive hemolysis inhibition test. In Salmonella minnesota R-form LPS, the specificity may be cryptic (R345, Rb2 mutant) or partly exposed in the intact molecule (R7, Rd1 mutant). The specificity is either demasked or completely exposed after mild acid hydrolysis for a short time, whereas it is destroyed after prolonged hydrolysis. Periodate oxidation, reduction, and hydrolysis under conditions that do not affect the ketosidic linkages of 2-keto-3-deoxyoctulosonic acid destroy the specificity in R4 (Rd2 mutant) LPS, but do not do so in R7 LPS. It is suggested that 2-keto-3-deoxyoctulosonic acid and a following neutral sugar are the compositional requirements for expressing the specificity.

Bacteroidaceae↗
PubMed1982

Morphological and functional studies on the lateral joints of the first and second cervical vertebrae in man.

The articular surfaces of the lateral atlanto-axial joints in man were analyzed with respect to their biomechanical aspects. The joint surfaces were investigated macroscopically, and the texture of the tangential fiber layer of the articular cartilage was studied with the aid of the split-line method. Furthermore, the thickness of cartilage was measured. From the results obtained the authors draw the conclusion that especially the mode of rotational movement between C1 and C2 changes within a life time. As a consequence, the distribution of stress in the lateral atlanto-axial joint is modified.

Adolescent↗
PubMed1982

Isolation, purification, and chemical analysis of the lipopolysaccharide and lipid A of Acinetobacter calcoaceticus NCTC 10305.

The lipopolysaccharide of Acinetobacter calcoaceticus NCTC 10305 (London) was obtained by a modified phenol/chloroform/light petroleum method from the bacterial cells and from the culture medium in yields of 1.6% and 2.2% respectively (based on the bacterial dry weight). On chemical analysis, both preparations proved to be identical. The lipopolysaccharide obtained from the cells was purified by repeated ultracentrifugation, electrodialysis, and precipitation with sodium chloride. It was free of nucleic acids, proteins, and glycans. In the analytical ultracentrifuge, the triethylamine and sodium salt forms of the lipopolysaccharide showed a s20 value of 8.9 S and 51 S, respectively. The lipopolysaccharide consisted of glucosamine, 3-deoxy-D-manno-octulosonic acid, D-glucose, fatty acids, and phosphate in a molar ratio of 2:1:7:6:4. The fatty acids were predominantly lauric acid, 2-hydroxy, and 3-hydroxylauric acid in a molar ratio of 1:1:2. Only 3-hydroxylauric acid was found in amide linkage. On mild acid hydrolysis of the lipopolysaccharide, 65% lipid A were obtained, to which glucosamine was retained quantitatively. It still contained 50% of the original glucose, while one third (15%) of the liberated glucose was in monomeric form.

Acinetobacter↗
PubMed1979

Serological cross-reactions between Acinetobacter calcoaceticus and chlamydiae.

A cross-reaction between Acinetobacter calcoaceticus and chlamydiae is described. A water-soluble, heat stable, non-dialyzable antigen was extracted from Acinetobacter species by boiling. This antigen fixed complement in the presence of homologous hyperimmune sera from rabbits or guinea pigs and in the presence of heterologous human or hyperimmunized animal sera containing chlamydial antibodies. Hyperimmune antisera to the extracted antigen, or to suspensions of live acinetobacters, also reacted in complement fixation with a group-specific antigen.

Acinetobacter↗
PubMed1979

[Complement-fixing antibodies to chlamydia in the population (author's transl)].

2,213 sera of normal persons and of men with nongonococcal urethritis were tested by CF. 4.5% of the males, 9.2% of the females, and 10.8% of the urethritis-patients had titers of 1 : greater than or equal to 16 when tested against a group-specific chlamydial antigen. The usefullness of the CFT for seroepidemiological studies was confirmed.

Adolescent↗
PubMed1976

[Formation and persistence of latexagglutination-inhibiting antibodies in rhesus monkeys infected with Coxsackie virus type B4 (author's transl)].

The formation and persistence of latexagglutination-inhibiting (LAH), neutralizing (N), and complement-fixing (CF) antibodies were in Rhesus monkeys afterr experimental infection with coxsackievirus type B4. In all 3 animals the LAH antibodies showed a significant decrease between the 49th and 56th day after infection. In 2 cases the CF antibodies declined to 25% of their maximum titer on day 84 after infection, and in 2 animals the N antibodies declined between the 70th and 84th day afte infection.

Agglutinins↗
PubMed1975

[Persistence of latex-agglutination inhibiting and neutralizing antibodies against enterovirus in the healthy population (author's transl)].

Sera of 122 persons were examined by the neutralization and latex-agglutination inhibition tests for antibodies against Polio type I, Coxsackie virus type A 9 and B 4, as well as Echo virus type 9. With increasing age there was a titre difference between latex-agglutination inhibiting and neutralizing antibodies, due to the earlier fall in the former. These antibodies, contrary to neutralizing ones, were in the lower titre region. The results confirmed the usefulness of the latex-agglutination inhibition test in the diagnosis of acute enterovirus infections.

Acute Disease↗
PubMed1975

[Formation and persistence of latex-agglutination-inhibiting IgG- and IgM-antibodies in rabbits inoculated with poliomyelitis, Coxsackie and encephalomyocarditis viruses (author's transl)].

The formation and presistence of virus specific IgG- and IgM-antibodies produced in rabbits after a single dose of poliomyelitisvirus, coxsackievirus or encephalomyocarditisvirus were tested comparatively by latex-agglutination-inhibition test, hemagglutination-inhibition test and neutralization test. The animals were immunized either intravenously alone or with Freund's complete adjuvant. The IgM-antibodies were only detectable for a short time by the three tests. In the IgG-fraction and in the unfractionated serum the neutralizing antibodies persisted without any loss in titer during the period observed, whereas the latex-agglutination-inhibiting and hemagglutination-inhibiting antibodies showed a significant decrease. The hemagglutination-inhibiting antibodies required 23 weeks (Figure 5), the latex-agglutination-inhibiting antibodies 7 weeks (without Freund's complete adjuvant; Figure 1 and 3) or about 16 weeks (with Freund's complete adjuvant; Figure 2, 4 and 5) respectively to decline to 25% of their maximum titer.

Animals↗
PubMedDate not supplied

Lipopolysaccharides: structural principles and biologic activities.

Structural principles of the three regions of the lipopolysaccharide molecule are briefly discussed. One of the recently available, chemically synthesized lipid A analogues has been tested for biologic activities. The preparation was found to be toxic, pyrogenic, and mitogenic. The amounts, however, needed for expression of effects similar to those of lipid A were about 500 times higher. These investigations are aimed at verifying the proposed structure of lipid A and at evaluating structure-activity relationships.

Animals↗
PubMedDate not supplied

Concepts of the chemical structure of lipid A.

Lipid A represents the covalently bound lipid component of lipopolysaccharides (LPS), the endotoxins and O antigens of gram-negative bacteria. Lipid A's of endotoxically active LPS consist of a beta(1'----6)-linked D-glucosamine disaccharide that carries phosphoryl groups in positions 1 and 4'. Depending on the origin of lipid A, nonacylated, nitrogen-containing residues may be bound to these phosphoryl groups. As shown in enterobacterial lipid A's, available hydroxyl groups of the D-glucosamine disaccharide are substituted by 3-deoxy-D-mannooctulosonic acid (position 6'), (R)-3-hydroxytetradecanoic acid (position 3), and (R)-3-(tetradecanoyloxy)tetradecanoic acid (position 3'). The hydroxyl group at C-4 appears to be free. The amino groups of the disaccharide carry (R)-3-(acyloxy)acyl [and (R)-3-hydroxyacyl] residues in a specific distribution. On the basis of these data, a proposal for a general structure of lipid A is made. As a specific example of this general architecture, the chemical structure of lipid A of Salmonella minnesota LPS is presented.

Lipid A↗
PubMedDate not supplied

Immunogenic properties of lipid A.

Lipid A, the endotoxic principle of gram-negative bacterial lipopolysaccharides, when suitably exposed on the surface of bacterial cells, becomes immunogenic, eliciting the formation of antibodies specific to lipid A. Antibodies to lipid A occur naturally in the serum of normal humans and many animal species; the two exceptions found so far are mice (all strains tested) and guinea pigs. Antibodies to lipid A occur more frequently in patients with infections caused by gram-negative bacteria, such as urinary tract infections. Antibodies to lipid A interacted with free lipid A but not with lipid A as present in the intact lipopolysaccharide molecule. Antibodies to lipid A were induced in rabbits, but not in mice, following a single injection of immunogenic lipid A. Because of similarities between the lipid A of many gram-negative bacteria, antibodies to lipid A showed wide cross-reactions. With regard to biologic activity, antibodies to lipid A have been variously shown to be protective, damaging, or without effect.

Animals↗