The role of Helicobacter pylori infection in hematological disorders

Helicobacter pylori (H. pylori) is a Gram-negative spiral bacterium, classified as a carcinogen of class I, according to the World Health Organization (WHO). The infection is a major cause of gastritis, gastric and duodenal ulcer disease and increases the risk of gastric cancer. It has been implicated in the pathogenesis of several gastrointestinal, systemic or hematological diseases. The present review aims in deciphering the role of the bacterium in hematological disorders, increasing the awareness of gastroenterologists, hematologists and internal medicine practitioners, regarding the bacterium-associated hematological diseases. The efficacy of H. pylori eradication in increasing the platelet count in adult patients with primary immune thrombocytopenia (ITP) has been confirmed, linking the infection with the disease. Moreover, as the bacterium causes iron deficiency anemia (IDA) by several mechanisms, recent guidelines indicate H. pylori infection (Hp-I) to be sought in IDA patients if histology is negative and to be eradicated if present. Furthermore, it has been widely recognized that anti-H. pylori treatment causes regression of the low-grade B-cell gastric MALT lymphomas. Despite the well established associations of Hp-I with the aforementioned hematological disorders, we highlight the possible role of the infection to other hematological diseases or conditions such as non-Hodgkin lymphomas of the stomach, monoclonal gammopathy of undetermined significance, megaloblastic anemia and myelodysplastic syndromes. We finally underline the elevated risk of childhood leukemia and of hemorrhage in patients with coagulation disorders, due to the infection.

The role of Helicobacter pylori infection in hematological disorders

Helicobacter pylori (H. pylori) is a Gram-negative spiral bacterium, classified as a carcinogen of class I, according to the World Health Organization (WHO). The infection is a major cause of gastritis, gastric and duodenal ulcer disease and increases the risk of gastric cancer. It has been implicated in the pathogenesis of several gastrointestinal, systemic or hematological diseases. The present review aims in deciphering the role of the bacterium in hematological disorders, increasing the awareness of gastroenterologists, hematologists and internal medicine practitioners, regarding the bacterium-associated hematological diseases. The efficacy of H. pylori eradication in increasing the platelet count in adult patients with primary immune thrombocytopenia (ITP) has been confirmed, linking the infection with the disease. Moreover, as the bacterium causes iron deficiency anemia (IDA) by several mechanisms, recent guidelines indicate H. pylori infection (Hp-I) to be sought in IDA patients if histology is negative and to be eradicated if present. Furthermore, it has been widely recognized that anti-H. pylori treatment causes regression of the low-grade B-cell gastric MALT lymphomas. Despite the well established associations of Hp-I with the aforementioned hematological disorders, we highlight the possible role of the infection to other hematological diseases or conditions such as non-Hodgkin lymphomas of the stomach, monoclonal gammopathy of undetermined significance, megaloblastic anemia and myelodysplastic syndromes. We finally underline the elevated risk of childhood leukemia and of hemorrhage in patients with coagulation disorders, due to the infection.

Horizontal cell differentiation in the retina of the Brazilian opossum, Monodelphis domestica

Differentiation of many diverse neuronal phenotypes is an essential part of nervous system development. We have studied the differentiation of horizontal cells, one of the basic neuronal types in the vertebrate retina, in a small, easily maintained marsupial by immunocytochemistry using antineurofilament and antivimentin antibodies. At birth the retina consists of proliferating neural epithelial cells, with a few early ganglion cells. Horizontal cells were first detected in 12-day-old pups; somas were within the epithelial neuroblastic layer and processes extended radially. By 19 days there were tangentially oriented dendrites and a few longer processes, the beginning of the outer plexiform (first synaptic) layer. By the time of eye opening (about 34 days) the basic histological organization of the mature retina was established. In the mature retina and during development, horizontal cell neurites in the outer plexiform layer, as well as ganglion cell axons, reacted strongly with several antineurofilament antibodies and with antivimentin; horizontal cell somas were detected only with one antineurofilament antibody. Only one population was detected, which we identify as the short-axon subtype, by comparison with horizontal cells in other marsupials and in eutherian mammals. This is the first description of the putative absence in a marsupial of one of the two horizontal cell subtypes found in most amniotes, including mammals so far studied, except murid rodents, which have only the short-axon subtype. Absence of one subtype in Monodelphis supports the hypothesis that the short-axon cell is the basic conserved phenotype of this class and suggests that experimental analysis of differentiation of horizontal cells in Monodelphis and murid rodents, compared to marsupials and eutherian mammals which have the basic two subtypes, can help elucidate mechanisms for controlling differentiation of specific cellular phenotypes and the variations in neurons within and among species.

Coronary-subclavian steal syndrome. Report of a case treated with subclavian angioplasty

We describe the case of a man aged 42 who, five years before, had undergone aortocoronary bypass surgery using the internal mammary artery for the anterior and saphenous vein graft for the posterior descending arteries. Over the last one and a half years he had started to present angina pectoris as well as symptoms of vertebrobasilar insufficiency during exertion of the left upper extremity (recently during simple writing), whereas a full treadmill test was normal. Clinically, obstruction of the left subclavian artery was suspected with both coronary and subclavian steals. This suspicion was confirmed with triplex of the vessels of the aortic arch, coronary arteriography and carotid arteriography which demonstrated severe obstruction of the left subclavian artery at its origin and reversal of blood flow through the ipsilateral vertebral artery and the internal mammary artery graft. Angina subsided after balloon angioplasty of the subclavian artery. This combined steal, termed coronary-subclavian syndrome, is rare (our case is probably the 20th reported), but an increase of its incidence is anticipated due to the widespread use of internal mammary artery grafts. The prevention and treatment of this syndrome are discussed.