Influence of GSTM1 and GSTT1 polymorphisms on the survival rate of patients with malignant glioma under perillyl alcohol-based therapy

GSTM1 (glutathione S-transferase mu 1) and GSTT1 (glutathione S-transferase theta 1) are critical enzymes for detoxification of endogenous and environmental carcinogens. Constitutive GST gene polymorphisms may be associated with increased risk for cancer development. We made an explorative study of a Brazilian population with malignant glioma to determine whether GSTM1 and GSTT1 genetic polymorphisms influence the response to intranasal administration of perillyl alcohol and the survival rate. Patients were stratified into groups according to clinical presentation, tumor classification, and tumor location. Circulating DNA was extracted from blood plasma or serum, and genotypes were detected by multiplex PCR. The cohort included 95 patients with recurrent malignant glioma included in a Phase I/II clinical trial with perillyl alcohol and 100 matched healthy control subjects. GSTM1 frequency was similar in patients with glioma (44%) and healthy controls (54%), but GSTT1 deletion was found in 11.5% patients, contrasting with 36% in controls. A longer survival rate was associated with a lack of GSTM1 deletion (31 weeks) and a deletion for GSTT1 (28 weeks). A poor survival rate was associated with GSTM1 deletion (23 weeks) and with a lack of a GSTT1 deletion (19 weeks). A significantly lower frequency of GSTT1 deletion in glioma patients compared to healthy controls indicates that GSTT1 deletion may exert a protective role against gliomagenesis, influence therapeutic response to intranasal perillyl alcohol treatment, and increase overall survival, especially considering tumor topography.

Expression of extracellular matrix ligands and receptors in the muscular tissue and draining lymph nodes of mdx dystrophic mice

The mdx mouse, an animal model of Duchenne muscular dystrophy, develops an X-linked recessive inflammatory myopathy. During onset of disease and height of myonecrosis, mdx mice also display important changes in the microenvironment of lymphoid tissues. Draining lymph nodes showed reduced cellularity and atrophy accompanied by intense immunolabeling for fibronectin, laminin, and type-IV collagen. Following clinical amelioration of dystrophy, mdx mice showed enhanced cellularity and a consistent increase in the absolute numbers of CD4(+) and CD8(+) cells expressing alpha4(high) and alpha5(high) extracellular matrix receptors. Furthermore, infiltrating cells in the proximity of myonecrosis expressed alpha4, alpha5, and alpha6 integrin chains during both height of myonecrosis and muscular tissue regeneration. Such results indicate that during distinct phases of muscular dystrophy, altered expression of extracellular matrix ligands and receptors may be influencing myonecrosis by promoting adhesion and migration of mononuclear cells into the altered skeletal muscle and toward local draining lymphoid tissue.

Chagas' disease encephalitis: intense CD8+ lymphocytic infiltrate is restricted to the acute phase, but is not related to the presence of Trypanosoma cruzi antigens

Central nervous system (CNS) damage can occur during Chagas' disease, especially in children and immunosuppressed patients. During the acute phase, amastigotes are rarely found, but inflammatory infiltrates are scattered throughout the CNS. Moreover, peripheral lymphocytes and antibodies recognizing neural components were described, suggesting the participation of the immune system in the genesis of neural lesions. Herein, we performed a histopathological study of Colombian-infected C3H/He mice, comparing the distribution of CNS-inflammatory infiltrates versus Trypanosoma cruzi antigens. Inflammatory infiltrates were observed during the acute phase, but did not correlate with the presence of detectable T. cruzi antigens. Infiltrates consisted mainly of CD8+ lymphocytes, although macrophages and a few CD4+ cells were observed. In the chronic stage of infection, although neuropathies were a common finding, only mild inflammatory infiltrates could be detected. Our results suggest that the presence of CNS inflammatory infiltrates is not directly related to the presence of parasite antigens and indicate that, different from chronic myocarditis, encephalitis resolves during the acute phase of Chagas' disease.

Modulation of fibronectin expression in the central nervous system of Lewis rats with experimental autoimmune encephalomyelitis

Fibronectin (FN), a large family of plasma and extracellular matrix (ECM) glycoproteins, plays an important role in leukocyte migration. In normal central nervous system (CNS), a fine and delicate mesh of FN is virtually restricted to the basal membrane of cerebral blood vessels and to the glial limitans externa. Experimental autoimmune encephalomyelitis (EAE), an inflammatory CNS demyelinating disease, was induced in Lewis rats with a spinal cord homogenate. During the preclinical phase and the onset of the disease, marked immunolabelling was observed on the endothelial luminal surface and basal lamina of spinal cord and brainstem microvasculature. In the paralytic phase, a discrete labelling was evident in blood vessels of spinal cord and brainstem associated or not with an inflammatory infiltrate. Conversely, intense immunolabelling was present in cerebral and cerebellar blood vessels, which were still free from inflammatory cuffs. Shortly after clinical recovery minimal labelling was observed in a few blood vessels. Brainstem and spinal cord returned to normal, but numerous inflammatory foci and demyelination were still evident near the ventricle walls, in the cerebral cortex and in the cerebellum. Intense expression of FN in brain vessels ascending from the spinal cord towards the encephalon preceded the appearance of inflammatory cells but faded away after the establishment of the inflammatory cuff. These results indicate an important role for FN in the pathogenesis of CNS inflammatory demyelinating events occurring during EAF.

Intrathecal reactivity for myelin components precedes development of neurological symptoms in AIDS patients

The central nervous system is considered an early and common target for the human immunodeficiency virus type 1 (HIV-1). Serum and cerebrospinal fluid (CSF) from 20 HIV positive patients, including 14 with AIDS-dementia complex (CDC stage IV) and 6 asymptomatic individuals (CDC stage II) were analyzed by enzyme immunoassay for detection of antibodies to native myelin basic protein (MBP) and for the amino acid sequence 68-84 exposed after partial degradation of native MBP. Control groups included HIV-1 negative patients with degenerative and/or vascular dementia, chronic multiple sclerosis (MS) and individuals without any sign of neurological or cognitive disturbances. As opposed to control groups, serum and CSF samples from MS and HIV-1 infected patients showed several oligoclonal bands running in the gamma region. AIDS-dementia complex (ADC) patients had increasingly high intrathecal IgG specific antibody titers for the amino acid sequence 68-84 of MBP. Marked intrathecal antibody production for myelin components was also detected in the majority of HIV-1 infected asymptomatic individuals. Such alteration paralleled development of cognitive deficits, neurological abnormalities and appearance of CNS demyelinating plaques. Preferential immune recognition of this myelin epitope within the CSF during early stages of HIV-1 infection might point to an ongoing process of active demyelination and ultimately indicate subclinical CNS involvement.

[The importance of mdx mouse in the physiopathology of Duchenne's muscular dystrophy]

The mdx mouse develop an X-linked recessive muscular dystrophy (locus Xp21.1) and lack dystrophin expression. Despite showing less intense myofibrosis and scarce deposition of fatty tissue, mdx mice are considered an adequate animal model for studies on the pathogenesis of Duchenne-type muscular dystrophy. Marked histological alterations in the muscular tissues associated to myonecrosis and inflammatory mononuclear cell infiltrate (lymphocytes, monocytes/macrophages) suggest a participation of the immune system in this myopathy. Modulation of the extracellular matrix (ECM) components in the muscular tissue during all phases (onset, myonecrosis and regeneration) of disease, indicate an important role for the ECM driving inflammatory cells to the foci of lesion. Therefore mdx mice should be regarded as an important tool for studies on pathogenetic mechanisms of Duchenne-type muscular dystrophy. Such experimental model would allow development of new therapeutic approaches for increasing survival and clinical amelioration.

Increased deposition of extracellular matrix components in the thymus gland of MDX mouse: correlation with the muscular lesion

The present work describes the expression of extracellular proteins in the thymus and skeletal muscle of the X-linked dystrophic MDX mouse which corresponds to an experimental model for the human disease Duchenne muscular dystrophy. MDX dystrophic mice showed marked alterations in the thymic cytoarchitecture including cortical atrophy that was paralleled by denser epithelial cell network with intense immunolabelling for cytokeratins pair 8/18 and increased vascularization assessed with monoclonal antibody anti-desmin. Consistent augmentation of intrathymic extracellular matrix components (ECM) was observed especially at weaning and by the onset of disease. Interestingly, the amount of ECM elements in the gastrocnemius muscle of MDX wild-type dystrophic mice also showed a prominent difference as compared to age-matched non-dystrophic BALB/cAn animals. A marked but uneven overdeposition of reticulin and collagen fibres (type I, type IV), laminin and fibronectin were often present in the skeletal muscle of dystrophic mice, mostly around lesioned fibres. Alterations in both organs positively correlated with the degree of dystrophy thus suggesting that similar stimuli may be enhancing ECM production in both thymus and skeletal muscle. Although the thymus gland might not be directly involved in the development of the murine X-linked muscular dystrophy, it should be considered as a further target in this disease.

Altered deposition of extracellular matrix components in the skeletal muscle and lymph node of the MDX dystrophic mouse

1. MDX mice derived from a colony of C57BL/10ScSn mice develop an X-linked recessive muscular dystrophy, thus providing an adequate model to study the pathogenesis of muscular dystrophy. 2. Skeletal myofibers of MDX mutant mice were heterogeneous, with disorganization of myofilaments and the absence of immunolabelling for dystrophin with monoclonal antibody DY4/6D3. 3. Marked deposition of reticulin, collagenic fiber (types, I, IV) and laminin (LN) were consistently present mostly around lesioned and necrotic myofibers associated with an intense inflammatory reaction, whereas strong immunolabelling for TIII-C, TIV-C and FN was often associated with regenerated fibers. 4. During the onset (3 weeks of postnatal life) of disease and height of myonecrosis (5-6 weeks of postnatal life), popliteal lymph nodes showed dense argyrophilic meshwork, intense immunolabelling for collagens types I and IV, FN, LN and enlargement of the hili which were packed with mononuclear cells. Such alterations, albeit less intense, were still observed in MDX mice with 20 weeks of postnatal life. 5. The results support the view that ECM components might be influencing the migration of inflammatory cells and the process of myonecrosis in the skeletal muscle of MDX dystrophic mice.

[Inhibitory effect of tumor growth by methionine-enkephalin]

Methionine-enkephalin (Met-Enk) is an endogenous opioid pentapeptide derived from the prohormone proenkephalin A, present in neuroendocrine and hematopoietic cells. Enkephalins are known to play an important role on the processes of induction, activation and control of immunomodulatory events. Met-Enk has been considered a potent antitumoral agent. The present study shows that Met-Enk exerts an inhibitory effect on the growth of a macrophage derived fibrous histiocytoma (MC-II) inoculated intradermally into BALB/cJ mice. Such effect was mainly influenced by the protocol, route of administration and concentration of Met-Enk used for treatment. Neither higher doses of Met-Enk injected intracerebrally or subcutaneously, nor the use of various protocols of treatment, did modify the process of tumorigenesis. In contrast, low dose (0.25 mg/kg) of Met-Enk injected intracerebrally together with tumor inoculation, significantly reduced tumor growth and prolonged survival rate.

Nonspecific esterase staining of lymphocyte subsets in leprosy

A comparative study of lymphocyte subpopulations from leprosy patients were carried out using nonspecific esterase (ANAE) staining and monoclonal antibodies. Regardless of the methodology used, an intense reduction in the total number of the T helper/inducer subset and an inversion of the helper/suppressor ration could be observed. These alterations were more evident with the progress of the disease from the tuberculoid (TL) to the lepromatous (LL) pole. Thus ANAE may be considered an economical and reliable method to be used in the study of the immune status of leprosy patients.