Immunopathological studies of Plasmodium berghei infected mice: (effect of carbon particles).

An attempt was made to block the role of the macrophages in the immune response by saturating them with carbon particles. The experiment was performed on Swiss albino female mice injected intraperitoneally with 10(5) P. berghei berghei. These mice were injected with carbon particles of 20 mgs on the day before the inoculation and again 10 mgs on day 4 and day 9 after the inoculation. The degree of parasitaemia was slightly higher throughout the experiment in the infected mice treated with carbon than in those untreated. By direct immunofluorescent method the free floating form of malaria antigen was detected in the infected organs (liver, kidney and spleen) on day 3 of infection onwards. The antigen was more intense in the carbon treated mice than in the untreated ones. The granular form of the antigen in the walls of glomerular capillaries of the kidney, in the Kupffer cells of the liver and in the reticulo-endothelial cells of the spleen, the malarial antibody and the immune complex (malaria antigen, antibody and mouse beta 1 C globulin) in the kidney were detected later on (day 11).     

Urinary neopterin in patients with systemic lupus erythematosus

Concentrations of neopterin were measured in urine specimens from 35 patients with active and eight with inactive systemic lupus erythematosus (SLE). Compared with those of apparently healthy controls, neopterin concentrations were higher in patients with active disease (P less than 0.001) and with inactive disease (P less than 0.01), those in patients with active disease being significantly higher than those in patients with inactive disease (P less than 0.001). The correlation between the neopterin concentration and evidence of disease activity was good. All of the patients with clinically active SLE had increased neopterin, but for only 37.5% (three of eight) did the neopterin concentration exceed the upper normal limit during clinical remission. The increase in neopterin concentration did not correlate with clinical courses or severity of renal function. Moreover, serial determinations of neopterin in active SLE patients showed a rapid decrease of initially high concentration, paralleling a decline of clinical activity after initiation of medical therapy. Thus, urinary neopterin may be a useful marker for monitoring disease activity in SLE patients.     

Infection of young adult mice with dengue virus type 2

Young adult female mice, five to six weeks old, were injected intraperitoneally with 2·5 × 10^6·3 LD₅₀ of dengue-2 virus, New Guinea C strain. The mice were killed on day 1, 2, 3, 4, 5, 6, 7, 10, 14, 21, 28 and 35 respectively. By means of the immunofluorescent antibody technique, viral antigen appeared as irregular granules in the reticuloendothelial cells of liver, lymph nodes and spleen of infected mice on the first day after inoculation and then diminished. From the fifth to sixth day of infection dengue antigen appeared again as homogeneous staining in the cytoplasm of single or groups of mononuclear cells in the lymphatic sinuses only. Later, by the third week of infection, dengue antigen could be seen in the mononuclear cells located in the marginal zone of lymphoid follicle of the spleen, the pattern of staining changing to bright spherical granules. At the same time, the deposition of immune complexes (composed of dengue antigen, mouse gamma and β1C globulin) could be seen in the renal glomeruli of infected mice.Serum antibody to dengue virus was found at low levels, being maximal on the 14th day after infection. Dengue virus was not isolated from the sera or from the infected organs. Granulomatous inflammation developed in lymph nodes and liver of mice infected with dengue virus and in mice inoculated with normal mouse brain suspension. Proliferative glomerular lesion was observed on day 14 after inoculation without definite abnormal urine findings.     

Asymptomatic bacteriuria in health and glomerulonephropathies

In a comparative study of prevalence of asymptomatic bacteriuria in a Thai population, 1.4% of 955 apparently healthy adults (12 female and 1 male) were found to have positive urine culture. Of these, 6 individuals grew staphylococcal coagulase-negative, 3 grew E. coli, and the rest grew various other organisms. Among 176 patients with glomerulonephropathies (GNP), 20.5% (17 male and 16 female) yielded positive urine cultures. These included 18 positive for E. coli, 3 for staphylococcal coagulase-negative, 5 for Klebsiella and 3 for Enterobacter; the rest grew various other organisms. There was a higher overall prevalence of asymptomatic bacteriuria in GNP when compared to the controls. Heavy proteinuria is also a predisposing factor for an increase in the prevalence of asymptomatic bacteriuria in female GNP only.     

In vitro studies of the normal human B lymphocyte receptors for preformed soluble dengue antigen-antibody complexes.

Preformed soluble dengue antigen-antibody with or without complement complexes could bind to the surface of human lymphocytes via IgG (Fc) or complement receptors respectively. It may be that these lymphocytes were B lymphocytes not T lymphocytes. Dengue antigen or antibody alone will not attach to the surface of those cells. It is emphasized that dengue antigen-antibody complexes can form in the circulation and some will bind to the surface of the B lymphocytes in vivo and play a significant role in the pathogenesis of dengue haemorrhagic fever. In addition mice could develop glomerulonephritis by injection with preformed soluble dengue antigen-antibody complexes. These mice showed proteinuria and deposits of the immune complexes in the glomeruli of the kidneys.     

Immunofluorescent staining of the surfaces of lymphocytes in suspension from patients with dengue hemorrhagic fever.

Immunofluorescent staining of lymphocytes suspensions from 55 of 62 patients with dengue hemorrhagic fever was positive for dengue antigen and human beta1C/a-globulin on the surface, from the second ay before shock or subsidence of fever. The percentages of positive staining of both components gradually increased to a maximum on the day of shock or subsidence of fever. B lymphocytes increased during the course of the disease. Neither dengue antigen nor human beta1C/a-globulin was detected on the surface of the lymphocytes from normal controls or patients with other diseases. By double immunofluorescent staining with different colors of fluorochromes, antidengue antibody with fluorescein isothiocyanate and antihuman gamma -globulin or antihuman beta1C/a-globulin with lissamine rhodamine B on the same lymphocytes revealed dengue antigen appearing only on B lymphocytes. The human beta1C/a-globulin and dengue antigen were located on the surface of the same lymphocytes. The pattern of the staining by both components showed fine and coarse irregular granules over the lymphocyte surface. The fluorescent granules seemed to be on the surface but not in the intracellular vacuoles of the lymphocytes.     

Establishment and characterization of a cholangiocarcinoma cell line from a Thai patient with intrahepatic bile duct cancer.

A new human cholangiocarcinoma cell line (HuCCA-1) was established from cholangiocarcinoma (CCA) tissue fragments surgically removed from a Thai patient with intrahepatic bile duct cancer. The growth medium used for the primary cell culture was Ham's F12 supplemented with 10% fetal bovine serum (FBS) and 10 ng/ml epithelial growth factor (EGF). Approximately one month later, the cells were subcultured in Ham's F12 supplemented with only 10% FBS. The population doubling time was approximately 55 hr. Staining of the cells for cytokeratin and mucin confirmed that the cells were mucin-secreting tumor of epithelial cell origin. The supernatant fluid secreted a number of non-specific tumor markers including CA125 and traces of MCA and AFP. The ability of the HuCCA-1 cell line to synthesize specific marker that may have potential in the diagnosis of cholangiocarcinoma is now being investigated.     

Cushing's syndrome caused by Ewing's sarcoma secreting corticotropin releasing factor-like peptide.

Procedures were carried out in a 12-year-old girl to relate Ewing's sarcoma of the left tibia with Cushing's syndrome. Computed tomography revealed a normal pituitary and hypothalamus but bilateral adrenal hyperplasia without focal enlargement, thus readily excluding hypothalamic-pituitary-adrenal tumor. Negative results from a high-dose dexamethasone suppression test do not support pituitary-dependent Cushing's disease. Ewing's sarcoma was diagnosed on tibial biopsy. The regression of the physical and biochemical findings of Cushing's syndrome subsequent to amputation of the left lower leg strongly suggests ectopic Cushing's syndrome caused by Ewing's sarcoma. Immunohistochemical studies of the resected bone were negative for corticotropin but positive for corticotropin releasing factor-like peptide. We conclude that this is the first reported case of ectopic Cushing's syndrome in a child that is caused by Ewing's sarcoma secreting corticotropin releasing factor-like peptide.