Evaluation of APOE polymorphisms and the risk for age-related macular degeneration in a Southeastern Brazilian population

This study aimed to evaluate the role of APOE polymorphisms (rs429358 and rs7412) in the risk of age-related macular degeneration in a sample of the Southeastern Brazilian population. Seven hundred and five unrelated individuals were analyzed, 334 with age-related macular degeneration (case group), and 371 without the disease (control group). In the case group, patients were further stratified according to disease phenotypes, divided into dry and wet age-related macular degeneration, and non-advanced and advanced age-related macular degeneration. APOE polymorphisms (rs429358 and rs7412) were evaluated through polymerase chain reaction and direct sequencing. In the comparison of cases vs. controls, none of the associations reached statistical significance, considering the Bonferroni-adjusted P-value, although there was a suggestive protection for the E3/E4 genotype (OR = 0.626; P-value = 0.037) and E4 carriers (OR = 0.6515; P-value = 0.047). Statistically significant protection for both the E3/E4 genotype and E4 carriers was observed in the comparisons: advanced age-related macular degeneration vs. controls (OR = 0.3665, P-value = 0.491 × 10⁻³ and OR = 0.4031, P-value = 0.814 × 10⁻³, respectively), advanced age-related macular degeneration vs. non-advanced age-related macular degeneration (OR = 0.2529, P-value = 0.659 × 10⁻⁴ and OR = 0.2692, P-value = 0.631 × 10⁻⁴, respectively). In the comparison of wet age-related macular degeneration vs. control, protection was statistically significant only for E3/E4 (OR = 0.4052, P-value = 0.001). None of the comparisons demonstrated any significant association for E2 genotypes or E2 carriers in age-related macular degeneration risk in this study. Findings suggest a protective role of the E4 haplotype in the APOE gene in the risk for advanced and wet forms of age-related macular degeneration, in a sample of the Brazilian population. To our knowledge, this is the first Brazilian study to show the association between APOE polymorphisms and age-related macular degeneration.     

Response of Calliphora vicina larval hemocytes to abiotic and biotic foreign particles injection

Human erythrocytes injection into the body cavity of Calliphora vicina postfeeding larvae results to their fast binding by thrombocytoidal fragments with agglutinates formation. There were almost none sites of lysis and degradation of erythrocytes in agglutinates even after shape modification and strands generation. Exceptions are zones of agglutinates with juvenile hemocytes, where destruction of erythrocytes is seen. The sequential injection of erythrocytes and charcoal particles leads to charcoal adhesion at first to agglutinates periphery and later to more deep stratum of cytoplasm between the erythrocytes. Under such conditions agglutinate formation period is accompanied with morphology variations which do not influence the intensity of agglutinating reaction. Juvenile plasmatocytes phagocytized the charcoal particles regardless of their concentration and duration of previous contact with erythrocytes. When mixture of abiotic and biotic particles was injected into post feeding larvae, crythrocytes and charcoal generate independent aggregations in the range of separate agglutinates. At the same time plasmatocytes form nodules consisting of temporary cell aggregations covered with cores of non phagocytized charcoal particles. These data testified that presumably lectin receptors responsible for foreign biotic and abiotic particles recognition are very near but not identical for different types of hemocytes. They may be specifical (for plasmatocytes) or integrated to different parts of cellular membrane (in thrombocytoids).     

Differentiation of the stable hyaline cells in response to foreign particles injections into the larvae of blowfly calliphora vomitoria

Injection of foreign particles (charcoal and human erythrocytes) into the larvae of Calliphora vomitoria provokes the complex immune response including their phagocytosis, nodulation and encapsulation by plasmatocytes and thrombocytoids. Precursors of thrombocytoids and analogs of Drosophila lamellocytes are very frequent during the periods of feeding and crop emptying, but fully disappear in wandering larvae. Injection of charcoal or erythrocytes into crop emptying larvae leads also to a dramatic increase in the number of stable hyaline cells, precursors of thrombocytoids. The hyaline cells differentiate from prohaemocytes and, quite possibly, from young weakly-specialized plasmatocytes in a day after injection. Later they are transformed to prothrombocytoids and thrombocytoids. The number of hyaline cells and young plasmatocytes in the crop emptying larvae of C. vomitoria is far greater than that in the same age larvae of C. vicina. Presumably it accounts for significantly increasing rate of stable hyaline cells differentiation in the injected larvae of C. vomitoria. Their part after injection of charcoal particles or erythrocytes may reach 40-50 % of the main haemocyte number compared to 20-25% in C. vicina. After completion of the crop emptying, the rate of hyaline cells differentiation in response to the foreign particles injection is evidently reduced but remains to be distinctly visible. Injections of saline also stimulate the differentiation of the stable hyaline cells from prohaemocytes but elevation of their amount is more weak and gradual. The bacterial immunization and needle prick show no effect. The treatments, inducing the rising of hyaline cells differentiation, lead also to pupariation delay. This correlation suggests involvement of the endocrine system into this process.     

The harvest and clinical application of the superficial peroneal sensory nerve for grafting motor and sensory nerve defects.

Potential donor nerves for autografting are finite and usually limited to cutaneous nerves of the extremities. The superficial peroneal nerve is the major lateral branch of the common peroneal nerve that innervates the peroneus longus and brevis muscles and provides sensation to the lateral aspect of the lower leg and the dorsal foot. It has generally been overlooked as a potential donor of nerve autografts. Cadaver dissections were performed on 10 fresh lower extremity specimens to investigate the anatomic characteristics of the superficial peroneal nerve and to refine a harvesting technique for the nerve. Thirty-one patients underwent nerve grafting of 39 upper and lower extremity nerves using the superficial peroneal donor. There were nine median nerves, four ulnar nerves, two radial nerves, two brachial plexus lesions, 16 digital nerves, and six lower extremity nerves grafted. The superficial peroneal nerve provided a consistently long donor, comparable in length to the sural nerve. The anatomic pattern is consistent, the patient positioning is simple, the surgical harvesting technique is straightforward, and the donor defect is acceptable. The superficial peroneal nerve provides a safe and valuable donor nerve, particularly in cases where multiple or very long nerve grafts are required.     

Mobilization of seed storage lipid by Arabidopsis seedlings is retarded in the presence of exogenous sugars

Background  

Soluble sugar levels must be closely regulated in germinating seeds to ensure an adequate supply of energy and building materials for the developing seedling. Studies on germinating cereal seeds indicate that production of sugars from starch is inhibited by increasing sugar levels. Although numerous studies have focused on the regulation of starch metabolism, very few studies have addressed the control of storage lipid metabolism by germinating oilseeds.     

Early events in the cellular formation of proparathyroid hormone

Early events in the cellular synthesis and subsequent transfer into membrane-limited compartments of pre-proparathyroid hormone (pre-proPTH) and proparathyroid hormone (proPTH) were investigated by electrophoretic analyses of newly synthesized proteins in subcellular fractions of parthyroid gland slices pulse-labeled for 0.5-5 min with [(35)S] methionine. During these short times of incubation, both pre-proPTH and proPTH were confined to the microsomal fraction. Labeled pre-proPTH and proPTH were detected in a 30-s interval between 0.5 and 1.0 min of incubation. The radioactivity in proPTH became relatively constant between 3 and 5 min, whereas the radioactivity in ProPTH increased markedly over this period. When corrected for the known content of methionine in the prohormone and the prohormone, we found four times as much radiolabeled prohormone as prehormone between 0.5 and 1.0 min of synthesis. Sequestration of labeled prohomrone into endoplasmic reticulum compartments was shown by treatment of the microsomal fraction with chymotrypsin and trypsin, which resulted in the degradation of the prehormone but not of the prohormones. Approximately 50 percent of pre-prohormone and 25 percent of prohormone were released from the microsomes by their extraction with 1.0 M KCl, whereas 80-90 percent of both was released by treatment with Triton X-100. These results in intact cells support the signal hypothesis proposed by Blobel and his co-workers in studies utilizing cell-free systems, inasmuch as the results indicate transfer of prohormone into the cisternal space of the rough endoplasmic reticulum concomitant with the growth of the nascent polypeptide chain. Appearance of membrane-sequestered proPTH takes place without entry of pre-proPTH into the cisternal space, suggesting that proteolytic removal of the leader peptide occurs during transfer of the polypeptide through the lipid bilayer. Further evidence in support of this process is that pre-proPTH is only partly extracted from the microsomes by treatment with 1.0 M KCl, suggesting that a substantial fraction of the nascent pre-proPTH is integrally inserted into the membranes before it is cleaved to form proPTH.