Mucosal layers and related nerve fibres in non-chagasic and chagasic human colon—a quantitative immunohistochemical study

Chagasic megacolon is accompanied by extensive myenteric and, simultaneously, moderate submucosal neuron loss. Here, we examined changes of the innervation pattern of the lamina propria (LP) and muscularis mucosae (MM). Two alternating sets of cryosections were taken from seven non-chagasic colonic and seven chagasic megacolonic specimens (the latter included both the dilated megacolonic and the non-dilated transitional oral and anal zones) and were immunohistochemically triple-stained for smooth-muscle actin (SMA), synaptophysin (SYN) and glial acid protein S100 and, alternatively, for SMA, vasoactive intestinal peptide (VIP) and somatostatin (SOM). Subsequent image analysis and statistical evaluation of nervous tissue profile areas revealed that, in LP, the most extreme differences (i.e. increase in thickness or decrease in nerve, glia and muscle tissue profile area, respectively) compared with control values occurred in the dilated megacolonic zone itself. In contrast, the most extreme differences in the MM were in the anal-to-megacolonic zone (except the profile area of muscle tissue, which was lowest in the megacolonic zone). This parallels our previous results in the external muscle coat. A partial and selective survival of VIP-immunoreactive in contrast to SOM-immunoreactive nerve fibres was observed in both mucosal layers investigated. Thus, VIPergic nerve elements might be crucial for the maintenance of the mucosal barrier. The differential changes of neural tissue parameters in LP and MM might reflect a multifactorial rather than a pure neurogenic development of megacolon in chronic Chagas’ disease.     

Nature and properties of humic acid prepared from different sources and its effect on nutrient availability

Summary Effect of sources, moisture levels and extractants on extraction, analytical properties, IR-spectra, macromolecular characteristics, interaction with cations and physiological properties of the extracted material (humic acid) were studied. Among the three variables, extractant influenced the degree of humification, IR-spectra, nature and properties of humic acids to a greater extent though the other two had significant contribution. Sodium pyrophosphate found to be an ideal extractant for humic acid. Reduced viscosity of humic acids increased with dilution particularly below 0.1 g/dl and decreased with increasing H⁺ concentration between pH 6.5 and 8.5 irrespective of source, moisture level and extractant. The amount of proton released and drop in initial pH of humic acids on addition of different metal ions indicated formation of mono-, di-hydroxy metal-HA complexes which broke down at pH 8.0 and above. HA-Fe²⁺ and HA-Cu²⁺ complexes were found to be most stable. Humic acids from different sources varied significantly in their effect on available nutrient status of soils though, the latter is main determining factor particularly for calcium and magnesium.     

Changes of fluorescence spectra of thymine in aqueous solution by radiation

Aqueous solution of thymine (5 X 10(-4) M, buffered at pH 7.0) was irradiated with 60Co gamma-rays under four different atmospheric conditions. In the presence of t-BuOH-N2, there was little increase in the fluorescence intensity as was previously reported in the radiolysis of cytosine. Under O2 there was also no significant increase differing from the case of cytosine. The fluorescence intensity was found to increase appreciably under N2O but it was less under N2 indicating that OH radical is mainly responsible for the formation of the highly fluorescent products. However, the fluorescence yields under these conditions were much lower in thymine radiolysis than cytosine radiolysis.     

Changes of fluorescence spectra of 2'-deoxyadenosine in aqueous solution by radiation

Aqueous solution of 2'-deoxyadenosine (5 X 10(-4) M, buffered at pH 7.0) was irradiated with 60Co gamma-rays under N2, O2, N2O and t-BuOH-N2 atmospheres in order to compare with adenine radiolysis previously reported. By exposure to radiation, the fluorescence was found to increase more markedly than that from adenine under all conditions of radiolysis. This result indicates that not only base moiety but also sugar moiety participate in the formation of highly fluorescent products. In this 2'-deoxyadenosine radiolysis, both OH and e-aq take part in the formation of such products, but OH predominates over over e-aq when both active species are present, as observed in adenine radiolysis.     

Colloid carcinoma of the breast with concomitant metastasis and a tuberculous lesion in the axillary lymph nodes. A case report.

A 30-year-old woman presented with a lump in the left breast and left axillary lymphadenopathy that, on fine needle aspiration cytology (FNAC), proved to be duct cell carcinoma with metastasis. Histology of the radical mastectomy specimen showed a mixed colloid carcinoma. Axillary lymph nodes revealed a variety of pathologic changes consisting of reactive hyperplasia, tuberculosis and metastasis. A combination of a tuberculous lesion and metastasis in the same lymph nodes was also found. During follow-up, after radiotherapy, the patient developed left supraclavicular and right cervical lymphadenopathy that, on FNAC, revealed a tuberculous lesion and metastasis, respectively. The rarity of this condition with double pathology is highlighted, and the reason behind the limitations of FNA in subtyping the primary malignancy and its failure to detect the tuberculous lesion in the axillary lymph node are discussed.     

Cross-linking activity of the 14-kilodalton beta-galactoside-specific vertebrate lectin with asialofetuin: comparison with several galactose-specific plant lectins.

We have previously shown that plant lectins with a wide range of carbohydrate binding specificities can bind and cross-link (precipitate) specific multiantennary oligosaccharides and glycopeptides [cf. Bhattacharyya, L., Fant, J., Lonn, H., & Brewer, C. F. (1990) Biochemistry 29, 7523-7530]. This leads to a new source of binding specificity: namely, the formation of homogeneous cross-linked lattices between lectins and carbohydrates. Recently, we have demonstrated the existence of highly ordered cross-linked lattices that form between the D-Man/D-Glc-specific plant lectin concanavalin A and the soybean agglutinin which is a tetrameric glycoprotein possessing a single Man9 oligomannose chain per monomer [Khan, M. I., Mandal, D. K., & Brewer, C. F. (1991) Carbohydr. Res. 213, 69-77]. In the present study, we have compared the ability of the 14-kDa beta-galactoside-specific lectin from calf spleen, a dimeric S-type animal lectin, and several galactose-specific plant lectins from Erythrina indica, Erythrina cristagalli, and Glycine max (soybean agglutinin) to form specific cross-linked complexes with asialofetuin (ASF), a 48-kDa monomeric glycoprotein, using quantitative precipitation analyses. The results show the formation of 1:9 and 1:3 stoichiometric cross-linked complexes (per monomer) of ASF to the 14-kDa lectin, depending on their relative ratio in solution. Evidence indicates that the three triantennary N-linked complex-type oligosaccharide chains of ASF mediate the cross-linking interactions and that each chain expresses either trivalency in the 1:9 cross-linked complex or univalency in the 1:3 complex.(ABSTRACT TRUNCATED AT 250 WORDS)     

Sequential pathological studies in the udder of goats intramammarily infected withAspergillus fumigatus

Intramammary inoculation of goats withAspergillus fumigatus spores resulted in the development of mastitis with characteristic gross and microscopic lesions. The mastitis and the lesions were restricted to the infected udder halves only and there was no dissemination of infection to other tissues of the body. The experiment was continued for 45 days. Gross changes in the infected udder were observed up to the 45th day post-infection. The lesions, in general, included variable sized abscesses in the first 15 days followed by development of varying sized greyish-white nodules in the infected udders. Microscopic changes consisted of granulomatous reaction with well developed granulomas in the infected udders. Hyphae and spores ofAspergillus fumigatus could be demonstrated in sections of the infected udders up to 45 days after infection. Reisolation of the fungus consistently was achieved up to 45 days. It is concluded that intramammary inoculation ofAspergillus fumigatus spores in goats leads to chronic granulomatous mastitis.     

Volatilization of mercury by immobilized mercury-resistant bacterial cells

Highly toxic mercury compounds may come into the environment through the use of mercury compounds as disinfectants for hospital and household purposes, Hg catalyst in industries, burning of coal and petroleum products, mercury-based pesticides and fungicides used in agriculture, and seed dressings. Toxic effects of mercury can be counteracted by microbial cells through the enzymes mercuric reductase and organomercurial lyase. Immobilized mercury-resistant bacterial cells of Azotobacter chroococcum could effectively volatilize mercury from mercury-containing buffer and detoxify mercury compounds. Moreover, the efficiency of mercury volatilization was much greater than with the native cells, as immobilized cells can be reused. Immobilized cells continuously volatilized mercury from mercury-containing buffer after four consecutive 24 h cycles. The storage stability of immobilized cells was much better than that of the native cells.