Molecular transduction in receptor-ligand systems by planar electromagnetic fields / Transdução molecular em sistemas receptor-ligante por campos electromagnéticos planares

The coupling of a ligand with a molecular receptor induces a signal that travels through the receptor, reaching the internal domain and triggering a response cascade. In previous work on T-cell receptors and their coupling with foreign antigens, we observed the presence of planar molecular patterns able to generate electromagnetic fields within the proteins. These planes showed a coherent (synchronized) behavior, replicating immediately in the intracellular domain that which occurred in the extracellular domain as the ligand was coupled. In the present study, we examined this molecular transduction - the capacity of the coupling signal to penetrate deep inside the receptor molecule and induce a response. We verified the presence of synchronized behavior in diverse receptor ligand systems. To appreciate this diversity, we present four biochemically different systems - TCR-peptide, calcium pump-ADP, haemoglobin-oxygen, and gp120-CD4 viral coupling. The confirmation of synchronized molecular transduction in each of these systems suggests that the proposed mechanism would occur in all biochemical receptor-ligand systems.

A ligação de um ligante com um receptor molecular induz um sinal que viaja através do receptor, chegando ao domínio interno e disparando uma cascata de resposta. Em trabalhos anteriores em receptores de células T e sua ligação com antígenos estranhos, observamos a presença de padrões moleculares planares capazes de gerar campos eletromagnéticos dentro das proteínas. Esses planos mostraram um comportamento coerente (sincronizado), replicando, instantaneamente, no domínio intracelular o que ocorreu no domínio extracelular, enquanto o ligante era acoplado. No presente estudo, examinamos essa transdução – a capacidade de um sinal de acoplamento de penetrar profundamente a molécula receptora e induzir uma resposta. Verificamos a presença de um comportamento coerente em sistemas diversos de receptor-ligante. Para apreciar essa diversidade, apresentamos quatro sistemas bioquímicos diferentes: TCR-peptídeo, ADP-bomba de cálcio, hemoglobina-oxigênio e gp120-CD4 acoplamento viral. A confirmação de transdução molecular sincronizada em cada um desses sistemas sugere que o mecanismo proposto ocorreria em todos os sistemas bioquímicos receptor-ligante.

[Artigo Parcialmente Retratado] Prevalência da infecção por Helicobacter pylori em pacientes dispépticos e associação com fatores de riscos clínicos para o desenvolvimento de adenocarcinoma gástrico / [article partial retraction] prevalence of helicobacter pylori infection in dyspeptic patients and its association with clinical risk factors for developing gastric adenocarcinoma

ABSTRACT BACKGROUND: In Brazil, particularly in the underdeveloped localities, the prevalence of Helicobacter pylori (H. pylori) infections can range up to 90%. These rates are higher in older individuals and vary by country region. H. pylori infections are linked to the development of gastric pathologies, namely mild to moderate gastritis, gastroenteritis, peptic ulcer, intestinal metaplasia, and gastric cancer. In 1994, this organism was classified by the International Agency for Research on Cancer (IARC) as pertaining to the Group 1 carcinogen for gastric adenocarcinoma etiology. Gastric cancer represents a significant public health problem, being the fourth most common malignant tumor and the second largest cause of cancer-related deaths. OBJECTIVE: To investigate the prevalence of H. pylori infection in dyspeptic patients and determine the link between clinical risk factors and gastric adenocarcinoma diagnosis. METHODS: Polymerase chain reaction (PCR) analysis was employed for molecular diagnosis of gastric tissue biopsies collected from 113 dyspeptic patients at the University Hospital of Federal University of Goiás. Molecular analyses allowed the identification of H. pylori infections. Furthermore, histopathological examinations were performed to determine the clinical risks of developing gastric malignancies. RESULTS: The test results identified 69 individuals older than 44 years, from 75 (66.4%) positive H. pylori infection samples. The prevalence of gastric adenocarcinoma in this study was 1.3%. Among the infected patients, six (8.2%) had high risk, and 67 (91.8%) had a low risk of developing gastric cancer (P<0.05). CONCLUSION: This study shows a high prevalence of H. pylori infection and identifies its contribution to gastric inflammations, which in the long term are manifested in high-risk clinical factors for the development of gastric adenocarcinoma.

RESUMO CONTEXTO: No Brasil, particularmente nas áreas mais pobres, a prevalência da infecção por Helicobacter pylori pode variar até 90%. Esses índices aumentam com o envelhecimento da população e são distintos entre as diferentes regiões do país. Podendo manifestar diferentes sintomatologias, essa infecção está diretamente relacionada com o desenvolvimento de patologias gástricas como gastrite leve a moderada, gastroenterites, úlcera péptica, metaplasia intestinal e principalmente, o câncer gástrico. Em 1994 a bactéria foi categorizada pela International Agency for Research on Cancer (IARC) como carcinógeno do Grupo 1 para adenocarcinoma gástrico, tipo de câncer que representa um importante problema de saúde pública, sendo o quarto tumor maligno mais comum e a segunda maior causa de mortes por câncer no mundo. OBJETIVO: Analisar a prevalência da bactéria em pacientes dispépticos e avaliar a associação de fatores de risco clínicos para desenvolvimento de adenocarcinoma gástrico. MÉTODOS: Biópsias de tecido gástrico coletadas de 113 pacientes dispépticos, atendidos no Hospital das Clínicas da Universidade Federal de Goiás, foram submetidas a diagnóstico molecular por meio de Reação em Cadeia da Polimerase, para identificação da infecção por Helicobacter pylori, e exame histopatológico, para avaliar o risco clínico de desenvolvimento de adenocarcinoma gástrico. RESULTADOS: Foram diagnosticadas 75 (66,4%) amostras positivas para infecção por Helicobacter pylori, sendo 69 indivíduos maiores de 44 anos de idade. A prevalência do adenocarcinoma gástrico nesse estudo foi de 1,3% e dentre os pacientes positivos para a infecção bacteriana seis (8,2%) possuem alto risco e 67 (91,8%) baixo risco de desenvolver esse tipo de câncer (P<0,05). CONCLUSÃO: Esse estudo mostra uma alta prevalência da infecção por H. pylori na população estudada e identifica sua intrínseca contribuição para inflamações gástricas, que a longo prazo se manifestam em fatores clínicos de alto risco para o desenvolvimento de adenocarcinoma gástrico.

Macrophages subpopulations in chronic periapical lesions according to clinical and morphological aspects

Abstract: The aim of this study was to evaluate macrophage M1 and M2 subpopulations in radicular cysts (RCs) and periapical granulomas (PGs) and relate them to clinical and morphological aspects. M1 macrophages were evaluated by the percentage of CD68 immunostaining associated with the inflammatory cytokine TNF-α, and M2 macrophages, by its specific CD163 antibody. The CD68+/CD163+ ratio was adopted to distinguish between the two macrophage subpopulations. Clinical, radiographic, symptomatology, treatment, and morphological parameters of lesions were collected and a significance level of p = 0.05 was adopted for statistical analysis. The results showed that the CD68+/CD163+ ratio was higher in the RCs (median = 1.22, p = 0.002), and the highest TNF-α immunostaining scores were found in RCs (p = 0.018); in PGs, the CD68+/CD163+ ratio was lower and associated with a greater CD163+ immunostaining (median = 1.02, p <0.001). The TNF-α in cyst epithelium had a score of 3 in 10 cases and predominance of M1 macrophages by CD68+/CD163+ (median = 2.23). In addition, CD68+ cells had higher percentage of immunostaining in smaller RCs (p = 0.034). Our findings suggest that increased CD68 immunostaining associated with TNF-α cytokine in RCs results in a greater differentiation of the M1 phenotype. The higher CD163 immunostaining in PGs results in greater differentiation of the M2 phenotype. Therefore, the inflammatory state promoted by M1 macrophages is related to growth and progression of RCs; on the other hand, the immunomodulatory state of M2 macrophages is related to maintenance of PGs.

FASN expression, angiogenesis and lymphangiogenesis in central and peripheral giant cell lesions

Central giant cell lesion (CGCL) and peripheral giant cell lesion (PGCL) are non-neoplastic proliferative processes of the jaws. PGCL is a reactive process induced by irritant local factors and CGCL is an intra-osseous lesion of unknown etiology. Both lesions exhibit similar histologic features showing abundant mononuclear cells, admixed with a large number of multinucleated giant cells and a rich vascularized stroma with extravasated erythrocytes, hemosiderin deposition, and blood-filled pools. Recent studies have linked fatty acid synthase (FASN) with angiogenesis. Objective: To evaluate angiogenesis and lymphangiogenesis and their relationship with FASN expression in CGCL and PGCL. Material and Methods: Thirteen CGCL and 14 PGCL of the jaws were selected for immunoexpression of FASN; CD34 and CD105 (to assess blood microvessel density [MVD] and microvessel area [MVA]); and D2-40 (to assess lymphatic MVD and MVA). Results: Within PGCL and CGCL, MVD-CD34 was signifcantly higher than MVD-CD10S, followed by MVD-D2-40. Moreover, a signifcantly higher number of FASN-positive multinucleated giant cells than mononuclear cells were observed. Between PGCL and CGCL, only MVD-CD34 and all MVA were signifcantly higher in PGCL. Positive correlation between MVA-CD10S with FASNpositive mononuclear cells in both lesions was observed. Conclusions: Our results show both lesions exhibiting similar levels of FASN expression and neoangiogenesis, suggesting constitutive processes that regulate tissue maintenance. .

Association between Elevated Pleural Interleukin-33 Levels and Tuberculous Pleurisy

BACKGROUND: Interferon-gamma (IFN-gamma) plays a crucial role in Mycobacterium tuberculosis induced pleural responses. Interleukin (IL)-33 up-regulates the production of IFN-gamma. We aimed to identify whether an association between pleural IL-33 levels and tuberculous pleurisy exists and determine its diagnostic value. METHODS: Pleural IL-33, ST2 (a receptor of IL-33), adenosine deaminase (ADA), and IFN-gamma, as well as serum IL-33 and ST2 were measured in 220 patients with pleural effusions (PEs). Patients with malignant (MPEs), parapneumonic (PPEs), tuberculous (TPEs), and cardiogenic (CPEs) pleural effusions were included. RESULTS: Pleural and serum IL-33 levels were highest or tended to be higher in patients with TPEs than in those with other types of PEs. The median pleural fluid-to-serum IL-33 ratio was higher in TPE cases (> or = 0.91) than in other PE cases (< or = 0.56). Pleural IL-33 levels correlated with those of pleural ADA and IFN-gamma. However, the diagnostic accuracies of pleural IL-33 (0.74) and pleural fluid-to-serum IL-33 ratio (0.75) were lower than that of ADA (0.95) or IFN-gamma (0.97). Pleural ST2 levels in patients with MPEs were higher than in patients with TPEs. Serum ST2 levels did not differ among the groups. CONCLUSIONS: We identified an association between elevated pleural IL-33 levels and tuberculous pleurisy. However, we recommend conventional pleural markers (ADA or IFN-gamma) as diagnostic markers of TPE.

Multifocal histiocytic sarcoma of the gastrointestinal tract.

We report a rare case of extranodal histiocytic sarcoma with multifocal gastrointestinal tract involvement, which has not been documented in the literature so far. A diagnosis of interdigitating dendritic cell/ histiocytic sarcoma was made on the preoperative gastric biopsy. Computed tomography scan revealed multifocal, circumferential gastrointestinal wall thickening involving the stomach and jejunal loops. Patient underwent distal gastrectomy with extended D1 dissection and proximal jejunal resection with gastrojejunostomy. Immunohistochemistry profile of both the gastric and jejunal tumors was similar to the preoperative gastric biopsy. The histiocytic origin of the tumor was confirmed by positive reaction of the tumor cells for CD 163. She received four cycles of CHOP chemotherapy, and is free of disease three years, following surgery.

Tissue distribution of sialic acid-linked influenza virus receptors in beagle dogs

Reports of influenza A virus infections in dogs has received considerable attention from veterinarians, virologists, and epidemiologists. Interaction between influenza viral hemagglutinin and cell oligosaccharides containing sialic acid residues results in infection. Sialic acids have an alpha-2,3-linkage to the penultimate galactose in the avian influenza virus receptor and an alpha-2,6-linkage in the human receptor. To date, there are no detailed data on the tissue distribution or histological features of either type of sialic acid-linked influenza virus receptors in beagle dogs, which are common laboratory animals and pets. We conducted the current study to visualize the in situ tissue distribution of both sialic acid-linked influenza virus receptors in various organs of beagle dogs using Maackia amurensis lectin II and Sambucus nigra agglutinin. Both alpha-2,3- and alpha-2,6-sialic acid-linked receptors were detected in the endothelial cells of the respiratory tract and other organs. Endothelial cells of most gastrointestinal organs were negative for alpha-2,3-sialic acid-linked receptors in the dogs. Our results suggested that these canine organs may be affected by influenza virus infection. The findings from our study will also help evaluate the occurrence and development of influenza virus infections in dogs.

Expression patterns of influenza virus receptors in the respiratory tracts of four species of poultry

The primary determinant of influenza virus infectivity is the type of linkage between sialic acid and oligosaccharides on the host cells. Hemagglutinin of avian influenza viruses preferentially binds to sialic acids linked to galactose by an alpha-2,3 linkage whereas hemagglutinin of human influenza viruses binds to sialic acids with an alpha-2,6 linkage. The distribution patterns of influenza receptors in the avian respiratory tracts are of particular interest because these are important for initial viral attachment, replication, and transmission to other species. In this study, we examined the distribution patterns of influenza receptors in the respiratory tract of chickens, ducks, pheasants, and quails because these species have been known to act as intermediate hosts in interspecies transmission. Lectin histochemistry was performed to detect receptor-bearing cells. Cell-specific distribution of the receptors was determined and expression densities were compared. We observed species-, site-, and cell-specific variations in receptor expression. In general, receptor expression was the highest in quails and lowest in ducks. Pheasants and quails had abundant expression of both types of receptors throughout the respiratory tract. These results indicate that pheasants and quails may play important roles as intermediate hosts for the generation of influenza viruses with pandemic potential.

Measurement of Interleukin-33 (IL-33) and IL-33 Receptors (sST2 and ST2L) in Patients with Rheumatoid Arthritis

The interleukin-33 (IL-33)/ST2 pathway has emerged as an intercellular signaling system that participates in antigen-allergen response, autoimmunity and fibrosis. It has been suggested that IL-33/ST2 signaling has been involved in the pathogenesis of rheumatoid arthritis (RA), because IL-33 and its receptor have been specifically mapped to RA synovium. The aim of this study was to determine the levels of IL-33 and sST2 in sera and synovial fluids in patients with RA. The serum level of IL-33 was significantly higher in patients with RA (294.9 +/- 464.0 pg/mL) than in healthy controls (96.0 +/- 236.9 pg/mL, P = 0.002). The synovial fluid level of IL-33 was significantly higher in RA patients than in osteoarthritis patients. The level of serum sST2 was higher in RA patients than in healthy controls (P = 0.042). A significant relationship was found between the levels of IL-33 and IL-1beta (r = 0.311, P = 0.005), and IL-33 and IL-6 (r = 0.264, P = 0.017) in 81 RA patients. The levels of IL-33, sST2 and C-reactive protein decreased after conventional disease-modifying antirheumatic drugs treatment in 10 patients with treatment-naive RA. Conclusively, IL-33 is involved in the pathogenesis of RA and may reflect the degree of inflammation in patients with RA.

Angiogenesis in the progression of cutaneous squamous cell carcinoma: an immunohistochemical study of endothelial markers

OBJECTIVE: To demonstrate the role of angiogenesis in the progression of cutaneous squamous cell carcinoma. INTRODUCTION: Angiogenesis is a pivotal phenomenon in carcinogenesis. Its time course in cutaneous squamous cell carcinoma has not yet been fully established. METHODS: We studied the vascular bed in 29 solar keratoses, 30 superficially invasive squamous cell carcinomas and 30 invasive squamous cell carcinomas. The Chalkley method was used to quantify the microvascular area by comparing panendothelial (CD34) with neoangiogenesis (CD105) immunohistochemical markers. The vascular bed from non-neoplastic adjacent skin was evaluated in 8 solar keratoses, 10 superficially invasive squamous cell carcinomas and 10 invasive squamous cell carcinomas. RESULTS: The microvascular area in CD105-stained specimens significantly increased in parallel with cutaneous squamous cell carcinoma progression. However, no differences between groups were found in CD34 sections. Solar keratosis, superficially invasive squamous cell carcinoma and invasive squamous cell carcinoma samples showed significant increases in microvascular area for both CD34- and CD105-stained specimens compared with the respective adjacent skin. DISCUSSION: The angiogenic switch occurs early in the development of cutaneous squamous cell carcinoma, and the rate of neovascularization is parallel to tumor progression. In contrast to panendothelial markers, CD105 use allows a dynamic evaluation of tumor angiogenesis. CONCLUSION: This study demonstrated the dependence of skin carcinogenesis on angiogenesis.

Endoglin [CD105] positive microvessel density and its relationship with lymph node metastasis in squamous cell carcinoma of the tongue

Neovascularization is an important factor for predicting tumor behavior. Evidence suggests that endoglin [CD105] is a powerful marker of neovascularization and determination of microvessel density in several malignancies, and can be used as an agent to predict lymph node metastasis. However, it is controversial, particularly in head and neck squamous cell carcinoma. We studied CD105-MVD in tongue squamous cell carcinoma and evaluated its correlation with lymph node metastasis in relation to sex, age, and histopathologic grade. This study analyzed a total of 40 cases of tongue squamous cell carcinoma by dividing patients into two groups, a] with meta-static lymph nodes [N+] and b] without metastatic lymph nodes [N-]. By CD105 immunostaining, microvessel density was determined in three different areas [intratumoral, invasive front and adjacent normal tissue] of all cases. Statistically, we evaluated the relation between microvessel density and lymph node involvement, in addition to other clinicopathologic factors by using the Kolmogorov-Smirnov test, f-test, and other analyses. CD105-MVD in the invasive front [P<0.001] and intratumoral [P<0.006] areas of the N+ group was significantly higher than in the N-group. In addition, there was a correlation between CD105-MVD and differentiation in the invasive front area [P< 0.013] No relation existed between CD105-MVD and other clinicopathologic features. CD105-MVD, as a prognostic factor, may be helpful for determining the possibility of lymph node metastasis of primary SCC of the tongue

Comparison of blood neoangiogenesis and lymphatic vascularization in colorectal adenomas from patients with and without concomitant colorectal cancer

Blood and lymphatic vessel proliferation is essential for tumor growth and progression. Most colorectal carcinomas develop from adenomas (adenoma-carcinoma sequence) in a process due to accumulation of molecular genetic alterations. About 5% of adenomatous polyps are expected to become malignant, but data on the differential angiogenic patterns of these lesions in patients with and without concomitant cancer are missing. The aim of the present study is to compare the angiogenic and lymphatic patterns of adenomatous polyps from patients with and without sporadic cancer. Thirty adenomatous polyps (15 from patients with another principal malignant lesion, and 15 from patients without cancer) were submitted to immunohistochemical staining for CD105 (marker for neoangiogenesis) and D2-40 (marker for lymphatic endothelium). Microvessel density and total vascular area were determined by computer image analysis to quantify the immunostained and total areas, and to assess the number of microvessels. Adenomas from patients with carcinoma showed significantly higher values of total vascular area determined by immunostaining for CD105 (cutoff value = 4386 µm²; P = 0.019) and of lymphatic microvessel density determined by immunostaining with D2-40 (cutoff value = 11.5; P = 0.041) when compared with those from patients without cancer. The present data indicate a significant increase in blood microvascular area and in lymphatic microvascular counts in adenomas removed from patients with cancer.

Expressão da cox-2 e CD105 no câncer de mama e sobrevida livre de doença / Cox-2 and CD105 expression in breast cancer and disease-free survival

OBJETIVOS: Correlacionar a presença de recidiva local de câncer de mama com a expressão de CD105 em carcinomas primários de mama, e a expressão da ciclooxigenase-2 nos carcinomas primários de mama e nos respectivos linfonodos axilares. MÉTODOS: Estudo com uma coorte histórica de 72 mulheres entre 29 e 67 anos com diagnóstico de carcinoma ductal infiltrante de mama, estadio II, tipo histológico não especial com seus linfonodos axilares respectivos, que tiveram diagnóstico e tratamento cirúrgico no Hospital Nossa Senhora da Conceição, no período de 2001 a 2002. Análise imunoistoquímica do CD105 e COX-2 no tumor primário, da COX-2 nos linfonodos axilares e da recidiva local. RESULTADOS: Das 72 mulheres analisadas com tumores primários, 40 tinham linfonodos axilares positivos e 32 eram negativos; para cada tumor primário, foi escolhido apenas um linfonodo axilar. O grau histológico dos tumores foi I (n=4), II (n=41) e III (n=27). Quinze pacientes apresentaram recidiva local em um período médio de 26 meses (IC 95 por cento 24-28). A presença da COX-2 nos tumores primários foi verificada em 52 casos, e a presença de CD105 em 34 casos, mas não foram considerados fatores prognósticos independentes para recidiva (p=0,203 e p=0,145, respectivamente). A sobrevida para pacientes com expressão da COX-2 em linfonodos axilares (metastáticos ou não metastáticos) foi de 19 meses, contra 28,3 meses para pacientes COX-2 negativa (p<0,0001). CONCLUSÃO: A expressão positiva da COX-2 em linfonodos axilares (positivos ou não) parece ser um fator prognóstico independente para sobrevida livre de doença.

Analysis of polymorphic regions of Plasmodium vivax Duffy binding protein of Korean isolates

The present study was designed to investigate polymorphism in Duffy binding protein (DBP) gene of Plasmodium vivax isolates of Korea. Thirty samples were obtained from P. vivax patients in Yonchon-gun, Kyonggi-do in 1998. The PCR products of the samples were subjected to sequencing and hybridization analyses of the regions II and IV of P. vivax DBP gene. Two genotypes, SK-1 and SK-2, were identified on the basis of amino acid substitution and deletion. The genotype of 10 isolates was SK-1 and that of 20 isolates was SK-2. Most of the predicted amino acids in the region II of DBP gene were conserved between the Korean isolates and Belem strain except for 4-5 amino acid substitutions. In the region IV of DBP, a 6-bp insert that was shown in the Sal-1 allele type was found in SK-1, and a 27-bp insert that was shown in the Papua New Guinea allele type was found in SK-2. In conclusion, the present findings suggest that two genotypes of P. vivax coexist in the endemic area of Korea.

Carcinomes mammaires: evaluation des recepteurs hormonaux et des marqueurs p52, erb-B2, P-glycoprotein, et Ki-67

The present study was performed on 45 mammary biopsies submitted to the Pathology Department, Hotel-Dieu de France Hospital, for evaluation of hormonal receptor. Histological typing and grading did not reveal any difference with the literature, but the mean size of tumor at clinical presentation was 4 cm [ +/- 1.6] and 83% of patients with known lymph node status, had metastases. Immunohistochemical assay for hormonal receptors on frozen sections disclosed positivity for estrogen and progesterone receptors in 18 cases [43%], similar to other studies. pS2, intracytoplasmic estrogen-induced protein, is positive in 19 out of 32 studied cases [59%], similar to what is reported by others. The latter does not appear to bring more information than hormone receptors considering therapy and prognosis. Oncoprotein C-erb B2 membrane over-expression is noted in 65% with no significant correlation to histological grade/size of tumor or node status. Antigen Ki-67 marker demonstrates high proliferation rates in 19 tumors [48.7%]. The markers studied do not seem to be more conclusive than the hormone receptors. The major fact disclosed by the study of this small series is the advanced stage at clinical presentation, urging an adequate medical education of the Lebanese population, and prompting to appropriate self-screening. Nevertheless, new tumor markers are continuously presented in the literature. In this era of marker extravaganza, a "wait-and-see" attitude would be a wise alternative

Cellular receptors, acceptors and clinical implications

Evidence of the existence of a special decodifier on the effector cells, with which inductor substances must interact in order to trigger their characteristic responses, has been found since the beginning of the century. These cytoplasmic sites are able to recognize, accept and receive the massage transmitted by the inductor substance, giving rise to a specific cell response. Thus, the inductor-receptor binding complex interaction at the cellular level may alter permeability to ions as happens with neurotransmitters, or can trigger ponocytosis in the case of apolipoproteins. Cellular receptors have been involved in the mechanism of action of several drugs and its dysfunction explains the physiopathology of a number of diseases. This may involve diminished clathrin protein synthesis triggering a defect in affinity, such as seen in malnutrition. It is also applicable in genetic distrurbances, which are capable of precluding receptor development as in cases of familiar hypercholesterolemia