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T Lehner

Publications and source records attributed to T Lehner.

324 records · Page 18Linked to original sources
PubMed1966

Systemic amyloidosis and malignant disease.

Among 8,758 necropsies there are 93 cases of systemic amyloidosis. Of these, 14 are associated with malignancy: seven with myelomatosis or malignant lymphoma, and seven with carcinoma. The incidence of amyloidosis in myelomatosis is at least 10%. Attention is drawn to the presence of amyloid in the tubular casts of ;myeloma kidney'. In Hodgkin's disease the incidence is about 4% but it may be higher in patients receiving chemotherapy. In lymphosarcoma it is of the order of a fraction of 1% but in macroglobulinaemia, essential or associated with malignant lymphoma, the incidence is considerably higher. Systemic amyloid is found in one in 375 of patients with carcinoma and in only a single patient among 1,500 ;control cases'. Renal carcinoma accounts for one-quarter of all carcinomas associated with systemic amyloid. The other carcinomas originate in a variety of organs. In myelomatosis, amyloid may be found in the tumour deposits. In Hodgkin's disease and in lymphosarcoma there appears to be greater amyloid deposition in neoplastic tissue than hitherto realized. The carcinomas provide a striking example of topographical association of amyloid and tumour, the two being closely related in six of seven cases.

Adenocarcinoma↗
PubMedDate not supplied

Immunological responses to bacterial plaque in the mouth.

A heavy load of bacteria, referred to as dental plaque, accumulates at the junction between the teeth and gum. Bacterial plaque may be considered to have three functional components: (a) cariogenic organisms, (b) organisms inducing gingival inflammation and periodontal disease, and (c) adjuvant and tolerizing agents, such as lipopolysaccharides, dextrans and levans. Sequential investigation of plaque accumulation in man has shown a correlation between gingival inflammation and both lymphocyte transformation and macrophage migration inhibition. An adjuvant effect of in vivo plaque accumulation was manifested by the enhancement of T lymphocytes in the mixed leucocyte culture reaction and of B lymphocytes, as shown by the increased response to lipopolysaccharide. It may be significant that a substantial component of bacterial plaque consists of dextrans and levans, produced by certain streptococci and actinomyces, and lipopolysaccharides from Gram-negative bacteria. These bacterial products are B cell mitogens which may have an adjuvant or tolerizing effect on immune responses. The relationships between immunogenicity, mitogenicity, adjuvanticity and tolerogenicity of lipopolysaccharides, levan and dextran have not been clearly defined. However, important variables of the polyglycans are the molecular weight, type of branching, negative charge, epitope density, degradability, dosage and the sequence between mitogen and antigen. Dental plaque in man is a focus of B cell mitogens and T cell antigens which may modulate the immune responses in such a way as to induce a protective response in the development of caries and a damaging response in periodontal disease.

Antigens, Bacterial↗
PubMedDate not supplied

Spastic paraplegia with iron deposits in the basal ganglia: a new X-linked mental retardation syndrome.

We report on a family with X-linked mental retardation (XLMR) and severe spastic paraplegia. Appearance is normal but there is severe involvement of the lower limbs (affected relatives never walked), with minimal involvement of the upper limbs and unusual MRI findings including macrogyria, white matter hypoplasia, lack of myelination and a markedly increased paramagnetic signal suggestive of iron deposition. Linkage studies documented possible linkage, with no recombination, between the disease locus and DXS424. A 7-point linkage analysis yielded a maximum LOD score of 1.9, (theta = 0.00) for three loci spanning Xq22-q25. The combination of the unusual clinical and MRI findings and the tentative localization to a region different than other XLMR syndromes with spastic paraplegia, provide good evidence that this is a new XLMR syndrome.

Adult↗
PubMedDate not supplied

Effect of route of immunisation and adjuvant on T and B cell epitope recognition within a streptococcal antigen.

Oral immunisation may elicit both systemic and mucosal immunity. Antibodies directed to a portion (residues 816-1213) of a cell surface adhesin termed streptococcal antigen I/II (SA I/II) of Streptococcus mutans prevent colonisation of this bacterium in vivo. This polypeptide is highly immunogenic in mice and is immunodominant in naturally sensitised humans. In this study, the effects of immunisation by different routes and of adjuvant on T and B cell epitope recognition were investigated. The recombinant polypeptide comprising residues 816-1213 of SA I/II was administered to groups of SJL mice intraperitoneally, subcutaneously or orally. For systemic immunisation, incomplete Freund's adjuvant was used, whereas for oral immunisation the antigen was coupled to the cholera toxin B subunit. The hierarchy of T and B cell epitope recognition differed significantly following different routes of immunisation. These differences in T and B cell responses may be accounted for by extracellular protease activity and processing by antigen presenting cells at the sites of immunisation. Furthermore, epitope recognition may be critical if the immune response elicited by a vaccine must be directed specifically to functional determinants within an antigen. This study emphasises the importance of route of immunisation in vaccine development.

Adjuvants, Immunologic↗
PubMedDate not supplied

Assessment of nonallelic genetic heterogeneity of chronic (type II and III) spinal muscular atrophy.

We have previously reported the mapping of the chronic (type II/intermediate and type III/mild/Kugelberg-Welander) form of the childhood-onset spinal muscular atrophies (SMA) to chromosome 5q11.2-13.3, with evidence for nonallelic genetic heterogeneity within a small sample of seven families [Brzustowicz et al., Nature 1990;344:540-541]. We now report the results of linkage analysis and heterogeneity testing on a set of 38 families with chronic SMA. Significant evidence for nonallelic heterogeneity was detected among these families, with the predominant locus for chronic SMA mapping to a 0.51-cM region on 5q, between the loci D5S6 and MAP1B. The estimated proportion of linked families, alpha, was 0.91, with a 2.3-unit support interval of 0.75 to 0.98. The indication that some families diagnosed with chronic SMA are not linked to chromosome 5q must be considered in strategies to map the SMA locus. The relevance of these findings to acute SMA (SMA type I, severe, Werdnig-Hoffmann disease) is still unknown.

Adolescent↗