Detecting Tumor Metastases: The Road to Therapy Starts Here.

Metastasis is the complex process by which primary tumor cells migrate and establish secondary tumors in an adjacent or distant location in the body. Early detection of metastatic disease and effective therapeutic options for targeting these detected metastases remain impediments to effectively treating patients with advanced cancers. If metastatic lesions are identified early, patients might maximally benefit from effective early therapeutic interventions. Further, monitoring patients whose primary tumors are effectively treated for potential metastatic disease onset is also highly valuable. Finally, patients with metastatic disease can be monitored for efficacy of specific therapeutic interventions through effective metastatic detection techniques. Thus, being able to detect and visualize metastatic lesions is key and provides potential to greatly improve overall patient outcomes. In order to achieve these objectives, researchers have endeavored to mechanistically define the steps involved in the metastatic process as well as ways to effectively detect metastatic progression. We presently overview various preclinical and clinical in vitro and in vivo assays developed to more efficiently detect tumor metastases, which provides the foundation for developing more effective therapies for this invariably fatal component of the cancerous process.

The lac permease of Escherichia coli: site-directed mutagenesis studies on the mechanism of beta-galactoside/H+ symport.

In this communication, we summarize site-directed mutagenesis studies of the lac permease from Escherichia coli, a prototypic H(+)-coupled active transport protein. We classify mutant permeases by phenotype, and suggest possible roles for some individual residues in the mechanism of H+/lactose symport. Although high-resolution structural information is not presently available, kinetic analysis of the partial reactions catalysed by the mutant permeases, as well as biophysical studies, suggest an evolving model for the mechanism of H+/lactose symport.

[Echocardiography in the evaluation of cardiac involvement in seronegative spondylo-arthropathies]. / El ecocardiograma en la evaluación del compromiso cardiáco en las espondiloartropatías seronegativas.

To evaluate the involvement of the heart in patients with seronegative spondyloarthropathies by echodopplercardiography, 35 patients including 20 with ankylosing spondylitis, 10 with Reiter's syndrome and 5 with psoriatic arthritis (21 men and 14 women, with ages ranging from 17-68 years and averaging 38.5) were studied. Most were asymptomatic with respect to the cardiovascular system (65.71%) and 12 oligosymptomatic with palpitations as their main complaint. Each patient had an echocardiogram and electrocardiogram. A two-dimensional echocardiogram demonstrated alterations in 19 patients (54.29%), 28.58% asymptomatic and 25.71% symptomatic. This study revealed most of lesions (17/19-84.47%) followed by the Dopplerechocardiography (10/19-52.63%) and the one-dimensional echocardiography (9/19-47.36%). Abnormal aortic valves were found in 10 patients, in 7 thickenning and in 3 calcifications. The mitral valve was involved in 11 patients, in 8 thickenning, in 1 calcification and in 2 valve prolapse. In ankylosing spondylitis aortic valve disease was found in 8 patients. Dopplerechocardiography evidenced the presence of aortic regurgitation in 4 patients and mitral insufficiency in 3. The Q-T interval was increased in 19 patients, there was one first degree auriculoventricular block, one right branch block and one sinus bradicardia. Thus the echocardiogram is an excellent noninvasive method to disclose cardiac disturbances in patients with seronegative spondyloarthropaties.

Chlamydia pneumoniae and atherosclerosis. Identification of bacterial DNA in the arterial wall.

OBJECTIVE: The intracellular Gram-negative bacterium Chlamydia pneumoniae has been associated with atherosclerosis. The presence of Chlamydia pneumoniae has been investigated in fragments of the arterial wall with a technique for DNA identification. METHODS: Arterial fragments obtained from vascular surgical procedures in 58 patients were analyzed. From these patients, 39 were males and the mean age was 65+/-6 years. The polymerase chain reaction was used to identify the bacterial DNA with a pair of primers that codify the major outer membrane protein (MOMP) of Chlamydia pneumoniae. The amplified product was visualized by electrophoresis in the 2% agarose gel stained with ethidium bromide, and it was considered positive when migrating in the band of molecular weight of the positive controls. RESULTS: Seven (12%) out of the 58 patients showed positive results for Chlamydia pneumoniae. CONCLUSION: DNA from Chlamydia pneumoniae was identified in the arterial wall of a substantial number of patients with atherosclerosis. This association, which has already been described in other countries, corroborates the evidence favoring a role played by Chlamydia pneumoniae in atherogenesis.

[Cardiac involvement in systemic lupus erythematosus. An echocardiographic evaluation]. / O envolvimento cardíaco no lúpus eritematoso sistêmico. Uma avaliação ecocardiográfica.

PURPOSE: To study, by a non-invasive method, patients with systemic lupus erythematosus (SLE), to evaluate possible cardiac involvement. METHODS: A hundred-eight lupic patients, 60 of them during activity, were studied, independently of cardiovascular signs and symptoms, by M-mode and two-D echocardiography and Doppler. Among the patients in the acute phase, 19 had never used steroid therapy before. RESULTS: Echocardiographic evaluation showed cardiac involvement in all patients who were in clinical activity. Seven had myocardial involvement with systolic impairment. In 35 patients, pericardial effusion was found, all in the acute phase. Regarding endocardial involvement, there were valve thickening in 54 patients in group I (acute phase), valve vegetations in eight and one with mitral valve prolapse. There were only six with valve thickening in group II (remission). Pulmonary hypertension was observed in 15 patients in the activity group and in two during remission. CONCLUSION: Echocardiogram has showed how frequent cardiac involvement is in SLE, especially during disease activity and being independent of previous steroid therapy. As it is a non-invasive method, it could be used in a routine protocol in the evaluation and follow-up of these patients.

Cardiac tamponade in systemic lupus erythematosus. Report of four cases.

OBJECTIVE: To report and assess the incidence of cardiac tamponade in systemic lupus erythematosus as a cardiac manifestation of the disease. METHODS: We reviewed the medical records of 325 patients diagnosed with systemic lupus erythematosus according to the American Rheumatism Association and their complementary laboratory tests compatible with cardiac tamponade. RESULTS: In the 325 medical records reviewed, we found 108 patients with pericardial effusions corresponding to 33.2% of the total and 54% of the patients studied in the active phase of the disease. Clinical assessment and transthoracic echocardiogram allowed the clinical diagnosis of cardiac tamponade in only 4 (1.23%) patients, 3 of whom were females, white, with ages ranging from 25 to 44 years. The pericardial fluid was hemorrhagic or serosanguineous with high levels of FAN and positivity for LE cells. In the treatment, we successfully used pericardiocentesis associated with high doses of corticosteroids. In clinical and laboratory follow-up performed for a period of 3 years, neither recrudescence of the pericardial effusion nor evolution to constriction occurred. CONCLUSION: Even though rare (1.23%), cardiac tamponade in patients with systemic lupus erythematosus has a benign evolution when properly treated, according to our experience.

[Tuberculous pericarditis as the initial manifestation of acquired immunodeficiency syndrome]. / Pericardite tuberculosa como manifestação inicial da síndrome de imunodeficiência adquirida.

The most common externalization of the acquired immunodeficiency syndrome (AIDS) is opportunist infection, and tuberculosis is one of the most frequent agents. The tuberculous pericarditis has been associated with AIDS, but it exceptionally occurs as the first event in the syndrome. We reported four cases in which tuberculous pericarditis was the initial manifestation of AIDS, characterizing by its clinical picture, diagnostic methods, therapeutics and the evolution of this involvement.

DNAJB6 chaperones PP2A mediated dephosphorylation of GSK3ß to downregulate ß-catenin transcription target, osteopontin.

Elevated levels of the oncoprotein, osteopontin (OPN), are associated with poor outcome of several types of cancers including melanoma. We have previously reported an important involvement of DNAJB6, a member of heat-shock protein 40 (HSP40) family, in negatively impacting tumor growth. The current study was prompted by our observations reported here which revealed a reciprocal relationship between DNAJB6 and OPN in melanoma specimens. The 'J domain' is the most conserved domain of HSP40 family of proteins. Hence, we assessed the functional role of the J domain in activities of DNAJB6. We report that the J domain of DNAJB6 is involved in mediating OPN suppression. Deletion of the J domain renders DNAJB6 incapable of impeding malignancy and suppressing OPN. Our mechanistic investigations reveal that DNAJB6 binds HSPA8 (heat-shock cognate protein, HSC70) and causes dephosphorylation of glycogen synthase kinase 3ß (GSK3ß) at Ser 9 by recruiting protein phosphatase, PP2A. This dephosphorylation activates GSK3ß, leading to degradation of ß-catenin and subsequent loss of TCF/LEF (T cell factor1/lymphoid enhancer factor1) activity. Deletion of the J domain abrogates assembly of this multiprotein complex and renders GSK3ß inactive, thus, stabilizing ß-catenin, a transcription co-activator for OPN expression. Our in-vitro and in-vivo functional analyses show that silencing OPN expression in the background of deletion of the J domain renders the resultant tumor cells less malignant despite the presence of stabilized ß-catenin. Thus, we have uncovered a new mechanism for regulation of GSK3ß activity leading to inhibition of Wnt/ß-catenin signaling.

Design of a membrane transport protein for fluorescence spectroscopy.

To modify the lac permease of Escherichia coli for fluorescence spectroscopy, six tryptophan residues at positions 10, 33, 78, 151, 171, and 223 were first replaced individually with phenylalanine by using oligonucleotide-directed site-specific mutagenesis. None of the tryptophan residues is critical for activity, as evidenced by the finding that the mutant permease molecules catalyze lactose/H+ symport almost as well as wild-type permease. Subsequently, a permease molecule was designed in which all of the tryptophan residues were replaced with phenylalanine. Remarkably, the lac permease harboring all six mutations catalyzes active lactose transport about 75% as well as wild-type permease. The fluorescence emission spectrum of purified wild-type permease solubilized in octyl beta-D-glucopyranoside and phospholipid exhibits a broad maximum centered at 350 nm, and the peak is almost completely absent from the spectrum of permease devoid of tryptophan. Furthermore, a new maximum centered at about 306 nm is apparent in the spectrum of the modified permease, suggesting that tyrosine fluorescence in the native protein is quenched by internal energy transfer to tryptophan residues. By using site-directed mutagenesis to replace specified residues in the molecule without tryptophan, it should now be possible to utilize tryptophan fluorescence spectroscopy to study static and dynamic aspects of permease structure and function.

TT virus infection in children and adults who visited a general hospital in the south of Brazil for routine procedure.

TT virus (TTV) is a newly described nonenveloped human virus, with a circular, negative-stranded DNA genome, that was first identified in the blood of a patient with posttransfusion hepatitis of unknown etiology. PCR primers and conditions used for TTV DNA amplification may greatly influence the level of TTV detection in serum. Three PCR assays, with different regions of the genome as targets, were used to test TTV DNA in 130 sera from children and adults visiting a hospital in the south of Brazil, most of them for routine procedure. Forty-four percent of adult sera and 73% of sera from children aged 0-10 years were TTV positive with at least one PCR assay. However, the three assays were able to detect only 33%, 35%, and 70% of the total positive samples. Our results showed a high prevalence of TTV infection in the south of Brazil, particularly among young children, and confirmed the necessity of performing several PCR assays to assess the true TTV prevalence in a determined population.