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The aim of this study was to evaluate the analgesic effect of the methanolic extract from callus culture of Phyllanthus tenellus, P. corcovadensis and P. niruri in several models of pain in mice. The extracts (medium containing 2,4-dichlorophenoxyacetic acid) of P. corcovadensis, P. niruri and P. tenellus (3-90 mg kg-1, i.p.) caused graded inhibition of abdominal constrictions induced by acetic acid (0.6%), with ID50 (i.e. dose that reduced response of control by 50%) values of about 30, 19 and > 30 mg kg-1, respectively. The extract of callus of Phyllanthus obtained in indole-3-butyric acid and indole-3-acetic acid media (3-90 mg kg-1, i.p.) caused a similar analgesic effect. In the formalin test, the extract of P. tenellus obtained in indole butyric acid medium (3-100 mg kg-1, i.p.) inhibited only the second phase of formalin-induced pain with an ID50 value of about 100 mg kg-1. Both the indole acetic acid and indole butyric acid methanolic extracts of P. tenellus and P. corcovadensis (10-100 mg kg-1, i.p.) dose-dependently inhibited both phases of formalin-induced pain (ID50 values for the second phase were approx. 100 and 52 mg kg-1, respectively). However, the extract of callus from Phyllanthus failed to affect formalin-induced paw oedema, as well as the response to radiant heat in the tail-flick test. In addition, the analgesic effect of morphine, but not the analgesic effects caused by Phyllanthus callus extract, was fully antagonized by naloxone.(ABSTRACT TRUNCATED AT 250 WORDS)

A large amount of evidence points towards the potential role of lymphokine activated killer (LAK) cells as tools in the treatment of chronically stressed conditions, such as cancer. The modulation of this activity by biologically active endogenous compounds of the HPA (hypothalamic-pituitary-adrenal) axis, however, is not completely understood. Ouabain, a specific inhibitor of Na(+)-K(+)-ATPase, and now recognized as an endogenous component present in human plasma, was tested on IL-2 and TPA-activated killer cells. Ouabain was able to inhibit the generation of LAK activity, as well as to suppress either PHA or TPA-induced lymphocyte proliferation. Once the cells were triggered for cytotoxicity, however, ouabain was not able to interfere with their effector phase, as it did not show any effect when present only during the assay. TPA-induced "LAK-simile" cells displayed the same sensitivity towards ouabain as LAK cells did. Although the physiological relevance of endogenous ouabain secretion remains elusive, these effects of ouabain on LAK cytotoxicity should be considered in patients undergoing this kind of immunotherapy.

Twenty-nine patients with severe aplastic anaemia (SAA) were submitted to bone marrow transplantation (BMT) and their immunological recovery analysed. Total lymphocyte counts, estimation of B lymphocytes, T lymphocytes and their subsets, natural-killer (NK) activity were performed. Cells with the CD8+ phenotype and NK activity were the first signs of immunological recovery, whereas the CD4+ subset recovered later in patients who suffered from acute graft versus host disease (GvHD) and infections. Acute and chronic GvHD, cirrhosis, rejection and HIV viral infection contributed to the persistence of the profound immunodeficiency status observed after BMT. Our results did not differ greatly from the others and confirmed that BMT may be performed in underdeveloped countries despite the difficulties it might pose.

A potent antivenom against snakebite was isolated from Curcuma longa, a plant commonly used in traditional Brazilian medicine. The fraction consisting of ar-turmerone neutralized both the hemorrhagic activity present in Bothrops jararaca venom, and the lethal effect of Crotalus durissus terrificus venom in mice. Immunological studies demonstrated that this fraction also inhibited the proliferation and the natural killer activity of human lymphocytes.

Canatoxin, a toxic protein isolated from Canavalia ensiformis, was shown to inhibit DNA synthesis and to produce a cytolytic effect when added in vitro to various cells, in doses ranging from 50 to 500 nM. In this case no selectivity was found for a certain cell type, as both normal and transformed cells could be affected by the toxic protein. The cytostatic effect was irreversible upon removal of the toxic protein from the medium and could be fully attained after exposing the cells to canatoxin for only 30 min. The use of an in vitro cell culture system may allow for a better insight on the mode of action of canatoxin.

The blastogenic reactivity of peripheral blood lymphocytes (PBL) and mesenteric lymph node lymphocytes (LNL) against normal allogeneic leukocytes and autochthonous colorectal carcinoma cells is evaluated in 36 patients, and correlated with the patient's Dukes classification. Mesenteric LNL react significantly better than PBL to allogeneic leukocytes in both Dukes B and C (p less than 0.05). There are too few patients in Dukes A and D to permit statistical evaluation but the trend is the same. By contrast, LNL fail to react to autochthonous tumor cells in all classes, except in a few Dukes B patients. The proportion of PBL reactivity to autochthonous tumor cells seems to increase for Dukes C and D. It is possible that specific lymphocyte reactivity in colorectal carcinoma may be related to the antigenicity and immunogenicity of the tumor.

Primary plasmacytomas of the colon are very rare. Six documented cases have been reported, and this article reports the seventh case. Plasmacytomas should be included in the differential diagnosis of a solitary tumor of the colon. They have a better prognosis than carcinomas and secondary plasmacytomas.

Two autopsy cases of CMV colitis in AIDS are reported. Intestinal manifestations lasted 2 and 5 months in each case and included: diarrhea and abdominal colic pain. The causes of death were: disseminated CMV infection in case 1 and miliary tuberculosis in case 2. In case 1 small ulcers were apparent in the ileum and the cecum. Microscopic foci of necrosis were also observed. Case showed: sigmoid dilatation with mucosal hemorrhages, small acute ulcers and submucosal fibrosis in the transverse portion of the colon. In both cases cytomegalic inclusion bodies within the endothelial cells of the capillaries at the bottom and the margin of the ulcers were observed. We compare our findings with those in other recently published cases.