Publications

OBJECTIVE

Little has been published about the length and determinants of survival for persons with AIDS in developing countries. This study examined the survival experience of Brazilian AIDS patients from 1982 to 1989.

DESIGN

A retrospective cohort study involving record review of reported AIDS cases.

METHODS

We obtained information about 2135 adult AIDS patients in Brazil. Local health officials supplied data regarding demographic and clinical characteristics and length of survival. Statistical techniques of survival analysis were applied.

RESULTS

Median survival was 5.1 months, much shorter than in developed countries, and there was no improvement in survival for cases diagnosed more recently. Younger patients and those in the intravenous drug use exposure category lived longer than other AIDS patients. Those presenting with Kaposi's sarcoma, esophageal candidiasis, and tuberculosis fared relatively well, while those presenting with multiple diagnoses or toxoplasmosis did more poorly.

CONCLUSIONS

These results tend to confirm the predictors of AIDS survival previously reported from developed countries and to document the poor survival of AIDS patients in the developing world.

Pulmonary manifestations are not infrequent in the L-tryptophan-induced eosinophilia-myalgia syndrome (EMS). However, previous reports have not described the results of longitudinal pulmonary function, exercise testing, high-resolution computerized tomographic (HRCT) scanning of the chest, or detailed bronchoalveolar lavage (BAL) analysis. We report six patients with EMS who had dyspnea. The diffusing capacity for carbon monoxide was decreased in five patients tested. Exercise testing with arterial blood gas sampling in three patients was consistent with pulmonary vascular or parenchymal disease. Serial exercise testing in two of these patients demonstrated marked improvement temporally associated with corticosteroid treatment. In four patients, HRCT scanning of the chest was abnormal. One of these patients showed no abnormality on routine chest roentgenogram. Two patients undergoing BAL exhibited increased eosinophils in the lavage fluid; a third had elevated lymphocytes. Serial measurements of fibroblast proliferation-stimulating-activity in samples of BAL fluid obtained from serial examinations in two patients exhibited heightened pretreatment activity that returned to the normal range following corticosteroid therapy. In these two patients, increased proportions of T-suppressor/cytolytic (CD8+) cells were observed in the BAL fluid. Despite aggressive immunosuppressive therapy, one of the patients died of respiratory failure. Another remains markedly dyspneic with pulmonary hypertension. Of the remaining four patients, two exhibited resolution of pulmonary symptoms after systemic corticosteroid therapy, and two experienced partial improvement.

Suicide inactivation of hepatic cytochrome P450 (P450) enzymes 2C11, 2C6, and 3A1/A2 by 3,5-dicarbethoxy-2,6-dimethyl-4-ethyl-1,4-dihydropyridine (DDEP) in intact rats results in prosthetic heme destruction, albeit by apparently distinct mechanisms. Such heme destruction is now shown to be associated with the loss of immunochemically detectable apoprotein of P450s 2C11 and 3A but with little of that of P450 2C6, in spite of their comparable DDEP-mediated functional inactivation. The loss of a approximately 50-kDa hepatic microsomal protein band along with the immunoreactive P450 3A loss strengthens the concept that such an in vivo loss indeed reflects proteolysis of the DDEP-inactivated P450. Furthermore, this propensity of DDEP-inactivated P450s 3A for proteolysis appears to correlate with the relative degree of prosthetic heme alkylation of their apoprotein rather than their functional inactivation per se. Thus, rapid degradation of apoP450s 3A was seen after DDEP treatment, which promoted extensive irreversible heme binding to apoP450s 3A, but not after exposure to allylisopropylacetamide (AIA), which inactivates these isozymes comparably, but induced minimal apoP450 3A heme alkylation. In addition, differences were observed in the relative sensitivities of proteolysis of DDEP-inactivated P450s 2C11 and 3A to hemin, which largely prevented the DDEP-induced proteolytic loss of P450 2C11 but apparently failed to prevent the loss of DDEP-inactivated P450s 3A, when coadministered with DDEP. This differential hemin sensitivity of the proteolysis of DDEP-inactivated P450 2C11, coupled with the observation that immunochemically detectable P450 2C11 loss occurs after its inactivation by both AIA and DDEP, provides compelling support for the existence of distinct proteolytic pathways for individual suicidally inactivated P450s.

Systematic exercise training results in changes in skeletal muscle that increase oxidative capacity and vascular conductance, which lead to an increase in maximal AVO2 difference. Also, maximal cardiac output is increased, largely because of an increase in maximal stroke volume. Heart rate is decreased at rest and during submaximal exercise because of increased parasympathetic tone and the effect of increased stroke volume on reflex sympathetic tone. The increases in maximal AVO2 difference and cardiac output result in increased maximal VO2, the hallmark of the dynamically trained individual. Predominant static exercise training results in fewer increases in maximal VO2 and more local muscle strength enhancements. The systematic application of cross-training can increase both cardiovascular and strength parameters, leading to enhanced athletic performance.

Schistosomiasis (bilharzia) is a parasitic disease caused by several species of schistosome worms (blood flukes). The key pathogenic event in this disease is the formation of granulomas around schistosome eggs trapped in portal venules of the liver. Granulomas are a distinctive form of chronic inflammation characterized by localized aggregation of activated macrophages around an inciting stimulus. Each granuloma evolves to form a fibrous scar; in schistosomiasis, the result is widespread hepatic fibrosis and portal hypertension. To identify the specific immune signal molecules necessary for granuloma formation, we studied schistosome infections in severe combined immunodeficient (SCID) mice, which have normal macrophages but lack functional B or T lymphocytes. Here we report that the immunoregulatory cytokine tumour necrosis factor alpha is necessary and sufficient to reconstitute granuloma formation in schistosome-infected SCID mice. Moreover, we find that the parasitic worms require tumour necrosis factor alpha for egg-laying and for excretion of eggs from the host. The implication of this latter result is that the parasite has adapted so successfully to its host that it uses a host-derived immunoregulatory protein as a signal for replication and transmission.

BACKGROUND

Transforming growth factor-beta 1 (TGF-beta 1), a potent growth modulator produced by a variety of tumor cells, as well as by platelets, has pleiotropic effects on cell-extracellular matrix interactions and may influence tumor cell invasion and metastasis.

PURPOSE

Our purpose was to characterize the effects of TGF-beta 1 on the adhesion, motility, and invasiveness of a metastatic human pulmonary carcinoma (A549 cell line) in vitro.

METHODS

A549 cells were seeded onto type I collagen gels, and invasion over a 9-day period was measured in the presence or absence of TGF-beta 1 (0.1-10 ng/mL). In addition, cell adhesion to substrata coated with type I collagen (1-100 nM) as well as haptotactic migration through filters coated with type I collagen (100 micrograms/mL) were measured following a 24-hour treatment with TGF-beta 1 (1-10 ng/mL).

RESULTS

TGF-beta 1 stimulated the invasion of A549 cells into type I collagen gels in a dose-dependent manner. Both the number of cells entering the gel and the depth of invasion into the gel were increased. In addition, the effects of TGF-beta 1 were blocked in a dose-dependent manner by a purified polyclonal IgG against TGF-beta 1 but not by normal rabbit IgG. A549 cell invasion was accompanied by dramatic changes in A549 cell morphology that included the appearance of numerous long pseudopodia, consistent with a change in the motile behavior of these cells. TGF-beta 1 stimulated by approximately fourfold the haptotactic migration of A549 cells on polycarbonate filters coated with type I collagen. The TGF-beta 1-mediated increase in invasion and motility was accompanied by a fourfold increase in A549 cell adhesion to type I collagen.

CONCLUSIONS

The results suggest that TGF-beta 1 can influence cellular recognition of extracellular matrix components and can modulate cellular adhesion and migration on these components, leading to increased invasive potential.

IMPLICATIONS

Given the wide-spread tissue distribution of TGF-beta 1 and its secretion by a variety of tumor cells as well as by platelets, TGF-beta 1 may be an important autocrineparacrine regulator of the invasive phenotype in vivo.