Misunderstanding as therapy: Doctors,patients and medicines in a rural clinic in Sri Lanka

In this paper I want to draw attention to the integration of Western medicine into therapeutic choices among patients in rural Sri Lanka. These patients' interpretation and use of Western pharmaceuticals is discussed in relation to the Ayurvedic theory of balance. The influence of this theory on people's ideas of health and illness is highlighted in encounters where laymen and professionals alike use Western medicines according to context and their respective perspectives. Such therapeutic encounters are used to describe how the meaning of therapy is negotiated and communicated. The modes of perception used by doctors and patients seem to be mutually exclusive but each has its own logic. Western medicines are used as a symbolic means which help the patients and the practitioners of Western clinical medicine in a rural health unit to communicate through — rather than despite — misunderstandings based on their differing cultural assumptions about the body, about disease and about therapy. This argument is raised in relation to recent theoretical discussions among medical anthropologists concerning doctor-patient relationships, asymmetric medical relations and the analysis of meaning systems     

Proof of a disulfide bridge accessible to disulfide exchange between the heavy chains of IgG

The paper deals with the direct experimental proof that human immunoglobulin G1 (IgG1) contains a reactive disulfide bond that can be opened by 3,3'-dithiobis(6-nitrobenzoate) (DTNB) within 24 h by a SH-catalysed disulfide exchange reaction. These results were obtained with the purified IgG1 myeloma protein and confirm earlier indirect evidence based on correlation analysis of DTNB reactivity and quantitative IgG1 determination. The reactive disulfide bond is most likely the one between Cys235 of the heavy chains in the "hinge"-region, activated for the disulfide exchange by the protonated amino groups of Lys231 as turned out by analysis of IgG1. As with the whole molecule, one mol of reactive disulfide was found per mol of the Fc-fragment. 0.8 mol of labile S-S bonds was detected per mol of F(ab)2. After separation of the excess of reagent, the sedimentation pattern still corresponded with the dimer. The unaltered antigenic properties as well as the crystallizability speak against any severe conformational changes. Therefrom it was concluded that in approximately 80% of the F(ab)2 molecules one of the two inter heavy chain-bridges was opened. With the isolated F(ab)-fragment a reaction with DTNB was ascertained to an extent of 20%, which is probably due to an altered stability of the heavy-light chain-SS-bridge. However, no influence on the sedimentation pattern was observed. The intrachainar disulfide bonds of neither the heavy nor the light chain reacted with DTNB to a measurable extent.     

The phylogenetic relations of DNA-dependent RNA polymerases of archaebacteria, eukaryotes, and eubacteria

Unrooted phylogenetic dendrograms were calculated by two independent methods, parsimony and distance matrix analysis, from an alignment of the derived amino acid sequences of the A and C subunits of the DNA-dependent RNA polymerases of the archaebacteria Sulfolobus acidocaldarius and Halobacterium halobium with 12 corresponding sequences including a further set of archaebacterial A+C subunits, eukaryotic nuclear RNA polymerases, pol I, pol II, and pol III, eubacterial beta' and chloroplast beta' and beta" subunits. They show the archaebacteria as a coherent group in close neighborhood of and sharing a bifurcation with eukaryotic pol II and (or) pol IIIA components. The most probable trees show pol IA branching off from the tree separately at a bifurcation with the eubacterial beta' lineage. The implications of these results, especially for understanding the possibly chimeric origin of the eukaryotic nuclear genome, are discussed.     

Nitrogen mineralization ofSesbania sesban used as green manure for lowland rice in Sri Lanka

Sesbania sesban was evaluated as green manure crop for lowland rice in the Dry Zone of Sri Lanka. The legume was grown during a fallow period before lowland rice (Oryza sativa) and ploughed under just before transplanting. Weight loss and nitrogen content in litterbags containing leaves, stems and roots of the legume were monitored. Comparisons were made between rice yields from 20 m² plots after green manuring in combination with different nitrogen fertilizer levels (0, 2.4, 4.8 and 7.2 gm⁻²) and nitrogen fertilizer (9.6 gm⁻²) alone. Above-ground biomass ofS. sesban was 440 gm⁻² (dry wt) when ploughed under after 84 days growth. N-content in leaves, stems and roots was 3.76%, 0.41% and 0.73%, respectively. This gave a N-input fromS. sesban of 9.2 gm⁻² (8.3 g from above-ground parts and 0.9 g from roots). The corresponding K and P inputs were 7.3 and 0.6 gm⁻² respectively. The nitrogen rich leaves, which contained 88% of the nitrogen in the above-ground parts, decomposed and released its nitrogen much more rapidly than the stems and roots. After only four days the leaves had released 5.3 g Nm⁻² and after 14 days they had released 6.4 g Nm⁻². The highest rice yield (505 gm⁻²) was obtained usingS. sesban and 4.8 gm⁻² of N-fertilizer. The yields with only N-fertilizer or onlyS. sesban were 442 gm⁻² and 396 gm⁻², respectively. Due to the rapid decomposition of the nitrogen rich leaves,S. sesban did not behave as a slow release fertilizer. Thus, it is not necessary to apply nitrogen fertilizers as a basal dose.     

Variations in the cytoplasmic region account for the heterogeneity of the chicken MHC class I (B-F) molecules

Molecular variation among major histocompatibility complex (MHC) class I (B-F) proteins from B-homozygous chickens is apparently caused by C-terminal variation. Analysis of the total B-F protein pool revealed substantial heterogeneity with two or three molecular mass constituents, each being comprised by several isoelectric focusing variants. This heterogeneity could not be reduced by enzymatic deglycosylation. By contrast, proteolytic removal of a small (M _r 1000–4000) fragment from the chain resulted in the generation of a M _r 36 000 fragment, common to all the molecular mass variants. Unlike the parent proteins, the M _r 36 000 fragment derived from isolated variants yielded identical, simple patterns in two-dimensional gel electrophoresis and identical finger prints in peptide mapping. This, together with N-terminal amino acid sequencing, as well as comparison of hydrophobicity properties of fragments obtained by gradual proteolytic digestion, indicated that the small peptide responsible for the major B-F heterogeneity was situated in the intracellular, C-terminal part.     

Immunoreactivity for laminin in the developing ventral longitudinal pathway of the brain

The first long tract to form in the brain of a vertebrate embryo is the ventral longitudinal pathway. In order to investigate what chemical cues may guide nerve growth cones along this pathway, affinity-purified antibodies to laminin and collagen type IV were used to stain sections of mouse embryos from Embryonic Days 8 through 17. A monoclonal anti-neurofilament antibody was used to show the development of the ventral longitudinal pathway in relationship to immunoreactivity for laminin and collagen type IV. At Day 8 fluorescent immunoreactivity for laminin is bright in the external limiting membrane of the neural tube, but the neuroepithelium does not show bright laminin or neurofilament immunoreactivity. At E9 the ventral longitudinal pathway is forming and punctate immunoreactivity for laminin is present on the surfaces of neuroepithelial cells in the marginal zone, through which axons of the ventral pathway extend. Punctate immunofluorescence for laminin remains concentrated in the marginal zone on Days E10 through E14, but on E16 punctate immunofluorescence was much reduced, although immunoreactivity for laminin remained bright in the maturing pial and arachnoid membranes and on blood vessels in the brain. Immunoreactivity for collagen type IV was strong in the external limiting membrane and on blood vessels, but never showed concentrated punctate immunofluorescence in the marginal zone. These results indicate that laminin may be available on cell surfaces and in extracellular spaces as an adhesive ligand for growth cones during the formation of the ventral longitudinal pathway.