Homeostatic regulation of sleep in a genetic model of depression in the mouse: effects of muscarinic and 5-HT1A receptor activation.

In depressed patients, sleep undergoes marked alterations, especially sleep onset insomnia, sleep fragmentation, and disturbances of the Rapid Eye Movement (REM) sleep. Abnormalities of rest-activity rhythms and of hypothalamic-pituitary-adrenocortical function have also been described in these patients. In the present study, we examined the presence of such abnormalities in a recently developed line of mice (Helpless mice-H) that exhibit depression-like behaviors in validated tests, compared to the nonhelpless (NH) line derived from the same colony. Experiments were essentially carried out in females for which previous studies showed marked differences between H and NH lines. Compared to NH mice, the H line exhibited (i) lower basal locomotor activity, (ii) sleep fragmentation, shift towards lighter sleep stages, and facilitation of REM sleep reflected by increased amounts and decreased latency, (iii) larger response to the REM sleep promoting effect of muscarinic receptor stimulation (by arecoline). In contrast, H and NH mice were equally responsive to the REM sleep inhibitory effect of 5-HT1A receptor stimulation (by 8-OH-DPAT). In addition, a deficiency in delta power enhancement after sleep deprivation was observed in the H group, and acute immobilization stress in this group failed to elicit a REM sleep rebound and was associated with a long-lasting raise in serum corticosterone levels. These results further validate H mice as a depression model and suggest they might be of particular interest for investigating the neurobiological mechanisms and possibly genetic substrates underlying sleep alterations associated with depression.     

Effects of Crotalus durissus collilineatus venom in the isolated rat kidney.

Ophidian accidents caused by the subspecies Crotalus durissus are responsible for high morbity and mortality rates. Acute renal failure is a common complication observed in these accidents. The aim of the present study was to investigate the renal effects promoted by the venom of C. d. collilineatus and its fractions, crotoxin and phospholipase A2. C. d. collilineatus (Cdc; 30 microg mL(-1)), crotoxin (CTX; 10 microg mL(-1)) and phospholipase A2 (PLA2; 10 microg mL(-1)) were tested in isolated rat kidney. The first 30 min of each experiment were used as an internal control and Cdc or its fractions, CTX and PLA2 were added to the system after this period. All experiments lasted 120 min. The venom of Cdc decreased perfusion pressure (PP; control120 = 110.3 +/- 3.69 mmHg; Cdc120 = 96.7+/-8.1 mmHg), renal vascular resistance (RVR; control120 = 6.42+/-0.78 mmHg mL g(-1) min(-1); Cdc120 = 4.8+/-0.56 mmHg/mL g(-1) min(-1)), urinary flow (UF; control120 = 0.19+/-0.03 mL g(-1) min(-1); Cdc120 = 0.12 +/- 0.01 mL g(-1) min(-1)), and glomerular filtration rate (GFR; control120 = 0.79 +/- 0.07 mL g(-1) min(-1); Cdc120 = 0.53 +/- 0.09 mL g(-1) min(-1)), but had no effect on the percent of sodium tubular transport (%TNa+), percent of chloride tubular transport (%TK+) and percent of potassium tubular transport (%TCl-). CTX and PLA2 reduced the GFR, while UF, PP and RVR remained stable during the full 120 min of perfusion. Crotoxin administration also diminished the %TK+ (control120 = 69.94 +/- 6.49; CTX120 = 33.28 +/- 4.78) and %TCl- (control120 = 79.53 +/- 2.67; CTX120 = 64.62 +/- 6.93). PLA2 reduced the %TK+, but exerted no effect on the %TNa+ or on that of TCl-. In conclusion, the C. d. collilineatus venom altered the renal functional parameters evaluated. We suggest that crotoxin and phospholipase A2 were involved in this process, since the renal effects observed would be due to the synergistic action of the components of the venom.     

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.