Angiogenesis in spontaneous tumors and implications for comparative tumor biology.

Blood supply is essential for development and growth of tumors and angiogenesis is the fundamental process of new blood vessel formation from preexisting ones. Angiogenesis is a prognostic indicator for a variety of tumors, and it coincides with increased shedding of neoplastic cells into the circulation and metastasis. Several molecules such as cell surface receptors, growth factors, and enzymes are involved in this process. While antiangiogenic therapy for cancer has been proposed over 20 years ago, it has garnered much controversy in recent years within the scientific community. The complex relationships between the angiogenic signaling cascade and antiangiogenic substances have indicated the angiogenic pathway as a valid target for anticancer drug development and VEGF has become the primary antiangiogenic drug target. This review discusses the basic and clinical perspectives of angiogenesis highlighting the importance of comparative biology in understanding tumor angiogenesis and the integration of these model systems for future drug development.

Mucin 6 and Tn antigen expression in canine mammary tumours: correlation with pathological features.

Overexpression of mucins is known to decrease cell-to-cell adhesion and thus to facilitate the invasion of cancer cells through the extracellular matrix. Mucin 6 (MUC6) is overexpressed and aberrantly O-glycosylated in human breast cancer, serving as a carrier for one of the most specific cancer-associated antigens, Tn antigen. Despite its relevance in breast cancer, MUC6 expression has not yet been characterized in canine mammary tumours (CMTs). The aims of this study were to assess the expression of MUC6 and Tn antigen in 55 benign and 77 malignant CMTs of different histological types and to investigate possible correlations with pathological features. MUC6 and Tn antigen were found to be significantly overexpressed in malignant compared with benign CMTs. MUC6 was significantly overexpressed in simple and complex carcinomas compared with simple and complex adenomas, respectively. When considering only the epithelial population, significant MUC6 overexpression was observed in carcinosarcomas when compared with benign mixed tumours. In addition, MUC6 was significantly overexpressed in simple compared with complex carcinomas. Finally, double-labelling immunofluorescence performed on seven malignant CMTs showed MUC6 and Tn co-expression. Therefore, MUC6 and Tn antigen overexpression is associated with malignant phenotypes of CMTs.

[RSI--repetitive strain injury. A questionable and harmful concept]. / LER--lesão por esforços repetitivos. Um conceito falho e prejudicial.

The hypothesis that repetitive movements and postures cause musculoskeletal injury is not supported by scientific data. The sensory and pain symptoms are better explained as of psychological and psychosocial nature, such as job dissatisfaction or disajustment, with financial gains objectives. The repetitive strain injury concept is iatrogenic and costly to society, and must be abandoned.

[Metal worker's perception of health problems and environmental risks at the work place]. / Percepção de trabalhadores metalúrgicos sobre problemas de saúde e riscos ambientais.

Research was carried out in Osasco, Greater São Paulo, to know the main health problems perceived by metalworkers' at their workplace and the need actions to prevent it or minimize them. With this objective in mind, 452 workers were interviewed at a metallurgic industry by means of a questionnaire in which they were asked first to mention five health problems perceived at the workplace, and then to select the most important one. They were also asked what they thought managers, supervisors and workers could do to avoid or minimize the main risk each worker had selected. According to their answer, although the chemical risk was the most frequently mentioned, the suggestions to actions to be implemented by supervisors and managers were related to psycho-social factors, that is, human problems of administration and organizational behavior.

A Brazilian cohort of patients with Tourette's syndrome.

The clinical features of 32 patients (24 males) with Tourette's syndrome in Brazil were studied. The mean age at onset was 7.1 years, tics being the first symptom in 71% and hyperactivity in 29%. Blinking, grimacing, and shoulder elevation were the most common motor tics and sniffing, throat clearing, and grunting noises, the most frequent vocal tics. Coprolalia was present in 28%, echolalia in 16%, palilalia in 9%, and copropraxia in 25% of patients. Attention deficit and hyperactivity disorder was diagnosed in 63%, and obsessive compulsive behaviour in 44% of patients. In 84% of patients there was a family history of tics whereas attention deficit and hyperactivity disorder and obsessive compulsive behaviour were respectively present in relatives of 19% and 53% of the patients studied. These data suggest that Tourette's syndrome in Brazil is not clinically different from other countries, supporting the notion that genetic factors play the most important part in its aetiology.

[Brown-Vialleto-van Laere syndrome: report of 2 cases]. / Síndrome de Brown-Vialleto-van Laere: relato de dois casos.

Brown-Vialetto-van Laere syndrome is a rare hereditary or sporadic degenerative disorder characterised by progressive sensoryneural deafness, followed or accompanied by cranial nerve palsies. The anterior horn cells and the optic pathways may be involved in some cases. We report two cases, and comment the differential diagnosis and the relationships of this syndrome to the muscle spinal atrophies and the hereditary deafness.

[Myasthenia gravis: results of thymectomy in 52 patients]. / Miastenia gravis: resultados de timectomia em 52 pacientes.

From 1971 to 1993, 52 myasthenics without thymomas (7 men and 45 women) were thymectomized. The results were categorized in remissions and non-remissions. The remission rate was 48%. In the remission group there were 5 men and 20 women and in the non-remission group 2 men and 25 women. The follow-up time was 5.5 years in both groups. There were 16 patients in Osserman category II A, 11 achieving remission; 36 patients were in categories IIB and III, and 14 achieved remission. The duration of disease was 1.8 years and 4.3 years in the remission and non-remission groups, respectively. All patients with remission had less than four years of disease but among the 43 patients with less than four years of symptoms, 42% did not achieve remission. Our data reinforce the need for early thymectomy in myasthenia gravis.

Syndrome of continuous muscle fiber activity. Case report with 11-year follow-up.

A 16-year-old male patient who presented with muscle stiffness and dysphonia is described. Electromyography revealed continuous motor activity that was unaffected by peripheral nerve block or general anaesthesia, but was abolished by curare. The patient had a marked improvement after using phenytoin. The follow-up 11-years later corroborates with the proposed benignity of this syndrome, in spite of being dependent on medication.

Canatoxin-, concanavalin A- and canavalin-cross-reactive materials during maturation of Canavalia brasiliensis (Mart.) seeds.

The distribution of three cross-reactive materials (CRMs), a toxic protein analogous to canatoxin, CNTX-CRM, a lectin analogous to concanavalin A, Con A-CRM, and a major storage protein, canavalin-CRM, was investigated during successive stages of maturation of Canavalia brasiliensis Mart. seeds. The data obtained by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and immunological analyses indicated that these proteins share extensive homology with the analogous proteins found in Canavalia ensiformis seeds. The changes in CNTX-CRM and Con A-CRM levels throughout the maturation process were assayed by rocket immunoelectrophoresis. Synthesis of Con A-CRM was detectable at 30 days post-anthesis (DPA) while its hemagglutinating activity appeared only at 35 DPA. The CNTX-CRM was detected as a biologically active protein from 30 DPA onwards. The behavior of CNTX-CRM during maturation of C. brasiliensis seeds was quite distinct from that of Con A-CRM, pointing to different biological roles of these proteins in the seed.

Cortico-basal ganglionic degeneration. A case report.

The case of a Brazilian patient with cortico-basal ganglionic degeneration (CBGD) is presented. Since three years ago, a 71-year old male displays asymmetric ideomotor apraxia, gait apraxia, cortical sensory impairment, myoclonus, limp dystonia and rigidity. His mental status is spared. There is neither consanguinity nor similar cases in his family. The differential diagnosis of CBGD is discussed. A brief review of the literature is made stressing the clinical and pathological features of CBGD. This disease is poorly known and probably underdiagnosed. Its diagnosis can be safely made based on clinical grounds.

Differences in macrophage stimulation and leukocyte accumulation in response to intraperitoneal administration of glucose/mannose-binding plant lectins.

Peritoneal macrophage stimulation (rapid spreading on glass surface and hydrogen peroxide production) and inflammatory reaction (leukocyte accumulation) obtained in C3H/HeJ mice at 8 weeks of age, after a single ip injection of 10 micrograms concanavalin A (Con A), a lectin extracted from Canavalia ensiformis, were compared with those obtained with two other glucose/mannose-binding lectins extracted from Canavalia brasiliensis (Con Br) and Dioclea grandiflora (DGL). All lectins enhanced macrophage spreading 3- to 4-fold at 24-72 h compared to control. Stimulation of hydrogen peroxide release by Con A, Con Br and DGL lasted 1, 2 and 3 days, respectively. Leukocyte cell influx at 24-72 h after lectin injection consisted mainly of mononuclear cells. Con A induced a moderate increase in the total number of peritoneal cells, whereas administration of Con Br or DGL increased the number of peritoneal cells 2- to 3-fold. The results indicate that DGL and Con Br have more pronounced effects on macrophage stimulation and inflammatory reactions than Con A.

Plant lectins, chemical and biological aspects.

Lectins, carbohydrate-binding proteins of non-immune origin, that agglutinate cells or precipitate polysaccharides and glycoconjugates, are well distributed in nature, mainly in the Plant Kingdom. The great majority of the plant lectins are present in seed cotyledons where they are found in the cytoplasm or in the protein bodies, although they have also been found in roots, stems and leaves. Due to their peculiar properties, the lectins are used as a tool both for analytical and preparative purposes in biochemistry, cellular biology, immunology and related areas. In agriculture and medicine the use of lectins greatly improved in the last few years. The lectins, with few exceptions, are glycoproteins, need divalent cations to display full activity and are, in general, oligomers with variable molecular weight. Although the studies on lectins have completed a century, their role in nature is yet unknown. Several hypotheses on their physiological functions have been suggested. Thus, lectins could play important roles in defense against pathogens, plant-microorganism symbiosis, cell organization, embryo morphogenesis, phagocytosis, cell wall elongation, pollen recognition and as reserve proteins. A brief review on the general properties and roles of the lectins is given.