Purification and biological effects of C-type lectin isolated from Bothrops insularis venom

Bothrops insularis is a snake from Queimada Grande Island, which is an island located about 20 miles away from the southeastern coast of Brazil. Compared to other Brazilian species of Bothrops, the toxinology of B. insularis is still poorly understood. Its C-type lectin is involved in several biological processes including anticoagulant and platelet-modulating activities. We purified the C-type lectin (BiLec) from Bothrops insularis venom and investigated its effect in the isolated kidney. BiLec was purified after two chromatographic steps; firstly, the whole venom was submitted to an HPLC molecular exclusion chromatography followed by a second purification through affinity chromatography. B. insularis lectin (BiLec) was studied as to its effect on the renal function of isolated perfused rat kidneys with the use of six Wistar rats. The concentration of 10 μg/mL increased perfusion pressure (PP; control₆₀=108.27±4.9; BiLec₆₀=112.9±5.4 mmHg; *p<0.05) and renal vascular resistance (RVR; control₆₀=5.38±0.51; BiLec₆₀=6.01±0.57 mmHg; *p<0.05). The urinary flow reduced significantly at 90 and 120 min of perfusion (UF; control₁₂₀=0.160±0.020; BiLec₁₂₀=0.082±0.008 mL g⁻¹ min⁻¹; *p<0.05). Glomerular filtration rate (GFR; control₁₂₀=0.697±0.084; BiLec₁₂₀=0.394±0.063 mL g⁻¹ min⁻¹; *p<0.05) diminished only at 120 min. BiLec did not change the percentage of sodium (TNa⁺), potassium (TK⁺) and chloride tubular transport (TCl⁻). The histological alterations probably reflected direct injury on glomerular and tubular renal cells, as demonstrated by the rise in permeability of glomerular endothelial cells, revealed by the presence of a proteinaceous material in the Bowman space. We postulate that the C-type lectin B. insularis promoted its effects probably through interactions with endothelial cells or through the release of other mediators by tubular, mesangial and endothelial cells.     

Cytostatic therapy and blood antioxidants/prooxidants balance in acute myeloblastic leukemia patients

To analyze the effects of conventional polychemotherapy of acute myeloblastic leukemia (AML) patients on the prooxidants/antioxidants balance in plasma total antioxidant status (TAS) and a single plasma antioxidant — uric acid (UA) were measured. Lipid peroxidation was assessed by malonedialdehyde (MDA) content. Total serum iron was monitored as a potential source of nontransferrin-bound iron with a role in initiation of oxidative burst. A group of patients in the acute phase of AML (group A) and a group of patients in complete remission of AML (group B) were studied. A strong correlation between UA values and TAS (r = 0.8 for group A, r = 0.9 for group B) was revealed in the course of the treatment. Strong negative correlation (r = −0.9) between TAS and MDA was shown for both groups. Total iron significantly increased in the course of chemotherapy. We have established that polychemotherapy leads to the consumption of antioxidants and increased lipid peroxidation in AML patients. An appropriate supplementation with antioxidants at the end of the polychemotherapy treatment could be considered.     

Treatment of primary g lioblastoma multiforme with c e tuximab, r adiotherapy and t emozolomide (GERT) – phase I/II trial: study protocol

Background  

The implementation of combined radiochemotherapy (RCHT) with temozolomide (TMZ) has lead to a significant increase in overall survival times in patients with Glioblastoma multiforme (GBM), however, outcome still remains unsatisfactory.     

Linkage of TP53 codon 72 pro/pro genotype as predictive factor for nasopharyngeal carcinoma development.

Genetic predisposition has been suggested as a cofactor for cancer aetiology and a polymorphism in TP53 codon 72 has been associated as a susceptibility factor for several cancers. Nasopharyngeal carcinoma is a rare neoplasia in western civilizations and genetic predisposition might play an important role in its development. We evaluated the linkage of the polymorphic variants (Arg/Pro) on TP53 codon 72 with nasopharyngeal cancer development in a case-control study with 392 individuals from a northern Portuguese population, including 107 patients with nasopharyngeal carcinoma and 285 healthy controls. This study revealed a three-fold risk for carriers of Pro/Pro genotype either against carriers of Arg/Arg (OR=2.62; 95% CI=1.10-6.30; P=0.016) or total Arg carriers (OR=2.67; 95% CI=1.21-5.90; P=0.012). Moreover, step-wise logistic regression analysis identified Pro/Pro genotype (OR=3.1; 95% CI=1.3-7.3; P=0.009), age >49 at diagnosis (OR=2.5; 95% CI=1.6-4.0; P<0.001) and male gender (OR=2.7; 95% CI=1.6-4.4; P<0.001) as predictive factors for the development of nasopharyngeal carcinoma. These results confirm the data from Asiatic populations suggesting that Pro/Pro genotype represents a stable risk factor for nasopharyngeal carcinoma development in Portugal and that TP53 codon 72 polymorphism can contribute as a genetic susceptibility marker, providing additional information to improve the knowledge about nasopharyngeal carcinoma aetiology.     

Intensive, very short-term chemotherapy for advanced Burkitt's lymphoma in children.

PURPOSE: To improve the 63% event-free survival (EFS) achieved before 1986 in Murphy's stage III to IV Burkitt's lymphoma (BL), both chemotherapy and supportive care were intensified. PATIENTS AND METHODS: From May 1987 to February 2001, 60 children, median age 9 years (range, 2.1 to 17 years), with advanced BL were enrolled onto two sequential institutional studies. From 1987 to 1992, 30 patients were stratified according to the absence (regimen IA, n = 19) or presence (regimen IB, n = 11) of bone marrow (BM) or CNS involvement. After 5-week cytoreductive chemotherapy consisting of vincristine, cyclophosphamide, doxorubicin, high-dose (HD) methotrexate (MTX), and intrathecal MTX or cytarabine, HD cytarabine and cisplatin were provided as a 4-day continuous infusion. Regimen IB was intensified by adding etoposide and HD ifosfamide and escalating MTX doses. Since 1992, regardless of BM or CNS status, 30 patients have been placed on regimen II, which is identical to IB but without ifosfamide. The scheduled duration of regimen II was 45 days. RESULTS: EFS and disease-free survival at 5 years are 81% +/- 5% and 87% +/- 5%, respectively, for 59 assessable patients (73% +/- 8% and 85% +/- 7% for regimen IA + IB, 89% +/- 6%, EFS and disease-free survival, for regimen II; median follow-up, 6.7 years; range, 0.6 to 13.5 years). Six patients, two of whom were receiving regimen II, died as a result of initial treatment failure or relapse, and five patients, none receiving regimen II, died as a result of treatment-related complications. CONCLUSION: This 45-day intensive chemotherapy program is the shortest schedule for disseminated BL and overcomes previously recognized risk factors such as BM and CNS infiltration.     

Left ventricular volume and mass in children on growth hormone therapy compared with untreated children

The myotropic effects of growth hormone (GH) have long been known. An excess of GH as in acromegaly, causes various problems within the circulatory system including cardiac hypertrophy. Although the latter has not been reported as a complication of GH therapy in children, we assessed this possibility in 54 children. Ninety-six echocardiographic studies were performed, in which bisectional images were analysed by Simpson's rule to determine left ventricular volume and mass. Of special interest were 47 results obtained from girls with Ullrich-Turner-syndrome (UTS) treated with supraphysiological doses of GH. Our results showed a significant increase of the myocardial mass in children on GH therapy compared with untreated children, as well as a dose related effect of GH on cardiac mass in girls and cardiac volume in boys. No cardiac hypertrophy, however, could be observed; the increase in muscular mass merely amounting to a normalization of previously low values.     

Advantages of Day 4 Embryo Transfer in Patients Undergoing Preimplantation Genetic Diagnosis of Aneuploidy

Purpose: Following preimplantation genetic diagnosis of aneuploidy, embryo transfer was executed on day 4, with the aim of providing more time for expanding from six to nine the number of diagnosed chromosomes per single cell (Group 2; 45 cycles). The results obtained were compared to those derived from conventional day 3 transfer (Group 1; 71 cycles). Methods: For multicolor fluorescence in situ hybridization analysis, two panels of probes were used: the first, specific for chromosomes XY, 13, 16, 18, and 21, was tested in all patients (Groups 1 and 2); the second was implemented only in Group 2 patients for the detection of chromosomes 14, 15, and 22. Results: A total of 406 embryos underwent fluorescence in situ hybridization analysis in Group 1, and 236 in Group 2. Comparable percentages of both chromosomal abnormalities (61% and 62%) and pregnancy and implantation rates (36% and 24.5% in Group 1, 41% and 23.6% in Group 2) resulted, regardless of the higher mean age in Group 2. Conclusions: The diagnosis of the nine chromosomes which are most frequently associated with aneuploidy in humans could have an immediate impact on the rate of spontaneous abortions. Additional advantages are represented by the more accurate morphological evaluation of euploid embryos; the advanced compaction, which means that embryos are less exposed to damage during the transfer procedure; and the possibility of performing a reanalysis in cases where a fluorescence in situ hybridization diagnosis is not obtained.     

Concurrent adjuvant chemotherapy and immediate breast reconstruction with skin expanders after mastectomy for breast cancer

Background. Immediate breast reconstruction (IBR) by means of skin expander is currently one of the most widely used methods of breast reconstruction in mastectomized patients. However, given that many breast cancer patients usually receive adjuvant chemotherapy, the adoption of IBR raises new questions concerning possible cumulative toxicity. The present study reports our experience in the use of concurrent adjuvant chemotherapy and immediate breast reconstruction with skin expander after mastectomy for breast cancer and the acute cumulative toxicity of the treatments. Methods. We evaluated a consecutive series of 52 breast cancer patients who have received IBR by skin expander after radical mastectomy and adjuvant chemotherapy concurrently during skin expansion between 1995 and 1998 (IBR/CT group). We identified two series of control patients treated during the same period: 51 consecutive patients undergoing radical mastectomy and IBR without adjuvant chemotherapy (IBR group) and 63 consecutive patients undergoing radical mastectomy and adjuvant chemotherapy without IBR (CT group). For each patient, we evaluated the incidence of surgical complications and chemotherapy's side effects and dose intensity. Results. The interval between surgery and the start of expander inflation was similar in IBR/CT (range 0–19, median 5 days) and IBR groups (range 0–40, median 5 days) and the timing of inflation was not influenced by chemotherapy. The overall incidence of surgical complications in patients undergoing IBR was low: seroma in eight cases, infection in one, skin necrosis in one, expander rupture in two and erythema in three. There were no statistically significant differences in the distribution of complications between the IBR/CT and IBR groups. The dose intensity of chemotherapy was similar between IBR/CT and CT groups, with a median dose intensity of 96% and 95% of the projected dose, respectively. The only statistically significant difference in terms of chemotherapy side effects (p=0.03) was that stomatitis was more frequent and intense in the CT than in the IBR/CT group. Conclusions. Concurrent treatment with IBR and adjuvant chemotherapy appears feasible and safe, it does not increase acute surgical complications or chemotherapy side effects, and does not require any changes in dose intensity or the timing of inflation.     

Evaluation of novel compounds interacting with H2-histamine receptors: Effect on histamine-sensitive adenylate cyclase activity in guinea-pig gastric mucosa

The activity of a number of compounds belonging to the novel class ofN-imidazolylphenyl-N'-alkyl-formamidines on histamine-sensitive adenylate cyclase was evaluated. All substances inhibited histamine-dependent adenylate cyclase activation. The compounds which were investigated in a wider concentration range, i.e. DA 4360, DA 4577, and DA 4626, behaved as simple competitive antagonists, yielding apparentK _B values comparable with those estimated in conventional H₂-receptor assays. These results provide further evidence for the highly selective H₂-receptor antagonism of these new molecules, and confirm the suitability of the histamine-stimulated adenylate cyclase assay in guinea-pig gastric cells as a functionally reduced system for the study of H₂ antagonists.