Ultrastructural and functional analysis of secretory goblet cells in the midgut of the lepidopteran Anticarsia gemmatalis.

Defoliation caused by Anticarsia gemmatalis larvae affects the commercial production of the soybean. Although regulation of the digestion of soybean components has become part of the suggested strategy to overcome problems caused by Anticarsia larvae, few studies have focused on the morphological and cellular aspects of Anticarsia intestinal tissue. We have therefore further analyzed the morphology and ultrastructure of the midgut of 5th instar larvae of A. gemmatalis. Dissected midgut was subjected to chemical or cryo-fixation and then to several descriptive and analytical techniques associated with both light and electron microscopy in order to correlate anatomical and physiological aspects of this organ. Histological analysis revealed typical anatomy composed of a cell layer limited by a peritrophic membrane. The identified lepidoptera-specific goblet cells were shown to contain several mitochondria inside microvilli of the goblet cell cavity and a vacuolar H(+)-ATPase possibly coupled to a K(+)-pumping system. Columnar cells were present and exhibited microvilli dispersed along the apical region that also presented secretory characteristics. We additionally found evidence for the secretion of polyphosphate (PolyP) into the midgut, a result corroborating previous reports suggesting an excretion route from the goblet cell cavity toward the luminal space. Thus, our results suggest that the Anticarsia midgut not only possesses several typical lepidopteran features but also presents some unique aspects such as the presence of a tubular network and PolyP-containing apocrine secretions, plus an apparent route for the release of cellular debris by the goblet cells.

Inorganic polyphosphates are stored in spherites within the midgut of Anticarsia gemmatalis and play a role in copper detoxification.

Inorganic polyphosphates (PolyP) are widespread molecules that have been shown to play a role in metal detoxification and heavy-metal tolerance. In the present report, we investigated the functional role of spherites as PolyP-metal binding stores in epithelial cells of the midgut of Anticarsia gemmatalis, a lepidopteran pest of soybean. PolyP stores were detected by DAPI staining and indirect immunohistochemistry as vesicles distributed in columnar cells and around goblet cell cavities. These PolyP vesicles were identified as spherites by their elemental profile in cell lysates that were partially modulated by P- or V-ATPases. PolyP levels along the midgut were detected using a recombinant exopolyphosphatase assay. When copper was added in the diet of larva, copper detection in spherites by X-ray microanalysis correlated with an increase in the relative phosphorous X-ray signal and with an increase in PolyP levels in epithelia cell lysate. Transmission electron microscopy of chemically fixed or cryofixed and freeze substituted tissues confirmed a preferential localization of spherites around the goblet cell cavity. Taken together, these results suggest that spherites store high levels of PolyP that are modulated during metal uptake and detoxification. The similarity between PolyP granules and spherites herein described also suggest that PolyP is one of the main phosphorous source of spherites found in different biological models. This suggests physiological roles played by spherites in the midgut of arthropods and mechanisms involved in heavy metal resistance among different insect genera.

Ommexecha virens (Thunberg, 1824) and Descampsacris serrulatum (Serville, 1831) (Orthoptera, Ommexechidae): karyotypes, constitutive heterochromatin and nucleolar organizing regions.

Chromosomes of Ommexecha virens and Descampsacris serrulatum (Ommexechidae) were analyzed through conventional staining, C-banding, base specific fluorochromes, silver nitrate impregnation (AgNO3), and fluorescent in situ hybridization (FISH) with probe for 45S rDNA. The two species presented diploid number 2n= 23,X0 in males and acrocentric autosomes, except the pair one that presented submetacentric morphology. The X chromosome has distinct morphology in the two analyzed species, being a medium acrocentric in Ommexecha virens and large submetacentric in Descampsacris serrulatum. The C-banding revealed pericentromeric blocks of constitutive heterochromatin (CH) in all the chromosomes of Descampsacris serrulatum. For Ommexecha virens it was evidenced that the blocks of CH are preferentially located in the pericentromeric area (however some bivalents presents additional blocks) or in different positions. The staining with CMA3/DA/DAPI showed GC rich CH blocks (CMA3+) in some chromosomes of the two species. The nucleolar organizer regions (NORs) were located in the bivalents L2, S9, S10 of Ommexecha virens and M5, M6, M7, S11 of Descampsacris serrulatum. The FISH for rDNA showed coincident results with the pattern of active NORs revealed by AgNO3. This work presents the first chromosomal data, obtained through differential cytogenetics techniques in Ommexechidae, contributing to a better characterization of karyotypic evolution for this grasshopper family.

Frequency of ABO blood group system polymorphisms in Plasmodium falciparum malaria patients and blood donors from the Brazilian Amazon region.

We investigated the ABO genotypes and heterogeneity of the O alleles in Plasmodium falciparum-infected and non-infected individuals from the Brazilian Amazon region. Sample collection took place from May 2003 to August 2005, from P. falciparum malaria patients from four endemic regions of the Brazilian Amazon. The control group consisted of donors from four blood banks in the same areas. DNA was extracted using the Easy-DNA(TM) extraction kit. ABO genotyping was performed using PCR/RFLP. There was a high frequency of ABO*O01O01. ABO*AO01 was the second most frequent genotype, and the third most frequent genotype was ABO*BO01. There were low frequencies of the ABO*O01O02, ABO*AA, ABO*AB, ABO*BB, and ABO*O02O02 genotypes. We analyzed the alleles of the O phenotype; the O(1variant) allele was the most frequent, both in malaria and non-malaria groups; consequently, the homozygous genotype O(1)(v)O(1)(v) was the most frequently observed. There was no evidence of the homozygous O(2) allele. Significant differences were not detected in the frequency of individuals with the various alleles in the comparison of the malaria patients and the general population (blood donors).

FTY720 and everolimus in de novo renal transplant patients at risk for delayed graft function: results of an exploratory one-yr multicenter study.

This exploratory, multicenter, open-label study evaluated the efficacy and safety of FTY720, as a part of an immunosuppressive regimen, in combination with everolimus and steroids in de novo renal transplant recipients at increased risk of delayed graft function (DGF). Patients received FTY720 (5 mg) and everolimus (4 mg) 2-12 h pre-transplantation, followed by 2.5 mg/d FTY720 and concentration-controlled everolimus (4-8 ng/mL) post-transplant for 12 months. Induction therapy was prohibited. After enrollment of 56 of the planned 200 patients between 2000 and 2002, the recruitment was terminated. The primary endpoint, rate of graft loss, or death at three months was 15.4% and the biopsy-confirmed acute rejection was 42.3%. Death or graft loss at 12 months in the DGF and non-DGF arms was 36.0% and 25.9%, respectively. The mean estimated creatinine clearance at three months was 63 and 55 mL/min in the non-DGF and DGF groups, respectively, while at 12 months it was 56 mL/min in both the groups. Although there was no comparator arm, the results from this exploratory study (compared with data from other phases II and III trials) indicated no apparent benefits of FTY720-based regimens for prevention of acute rejection and preservation of renal function in renal transplant recipients at high risk of DGF.

Corticosteroid reduction with tacrolimus (CORRETA) TRIAL: a prospective Brazilian multicenter, randomized trial of early corticosteroid reduction versus regular corticosteroid dosage maintenance on a tacrolimus (Prograf) and mycophenolate mofetil (Cellcept) immunosuppression regimen in kidney transplant recipients: interim analysis.

Corticosteroids are a cornerstone of immunosuppressive therapy in renal transplantation despite their side effects and morbidity. Newer immunosuppressive agents may be more effective to allow corticosteroid sparing. An interim analysis of 60 completed out of 100 planned primary kidney transplant recipients is presented. All patients on tacrolimus (Prograf) and MMF (Cellcept) were randomized into two groups following a 1:1 distribution for early steroid reduction at posttransplant day 7 (G1; n = 31) versus to long-term maintenance steroids (G2; n = 29). Primary efficacy endpoints were composite endpoint of death, graft loss, or severe acute rejection at 6 and 12 months follow-up. Safety evaluation included severity and frequency of diabetes mellitus, hypertension, hyperlipidemia, leukopenia, infection, malignancy, and severe adverse events. Mean age was 39.1 years, with 45.0% males and 66.7% Caucasians. African-Americans were 25.8% in G1 and 27.6% in G2. One death occurred in each group, as well as one case of severe (Banff III) rejection in G1 (P = 1.00). The incidence of rejection episodes between groups was not significant, namely, 41.9% in G1 and 20.7% in G2 (P = .077). There were no differences between groups concerning mean, systolic and diastolic blood pressure, HbA1c, or creatinine at 12 months. This interim analysis showed no evidence of an increased risk of poorer performance among the early steroid reduction or safety differences in kidney transplant recipients versus a regular dosage steroid group of patients. Further analysis of the complete study data is underway.

Incidence of delayed graft function in cadaveric kidney transplants in Brazil: a multicenter analysis.

To evaluate the frequency of delayed graft function (DGF) in kidney transplant centers in Brazil, we sent a questionnaire requesting information on the number of cadaveric donor kidney transplants performed during the years 2000, 2001, and 2002, the number of early nonfunctioning grafts, and the number of patients on dialysis during the first posttransplant week with subsequent recovery. Among all centers performing more than 50 kidney transplants during the last year of evaluation, 6, performing 612 cadaveric kidney transplants during the study period, replied to the questionnaire. Sixty procedures (9.7%) resulted in nonfunctioning grafts, while 312 (55.6%) patients required dialysis during the first Ptx week: 216 (53.9%) in 2000, 189 (62.3%) in 2001, and 216 (51.6%) in 2002. The frequency of DGF during the study period was higher than that noted by several previous foreign studies. To better evaluate the possible causes of this finding, a more extensive and focused study is warranted.

One living donor and two donations: sequential kidney and liver donation with 20-years interval.

The shortage of cadaveric donor organs remains the critical factor limiting the use of organ transplantation. In this environment of organ shortage, living donor transplantation has emerged as a reasonable therapeutic alternative. Simultaneous kidney-liver transplantation from the same donor has been described. We report a case of right liver lobe transplant from a living donor who had donated his kidney to the same recipient 20 years prior.