Repeated exposure to cocaine during adolescence enhances the rewarding threshold for cocaine-conditioned place preference in adulthood

Previous studies have shown that adolescent exposure to cocaine increases drug use in adulthood, albeit incubation of cocaine seeking was found to be attenuated in rats trained to self-administer cocaine during adolescence. We here hypothesize that adolescent exposure to cocaine could alter the rewarding properties of the psychostimulant in adulthood. By employing two of the most widely used animal-experimental-preclinical models to investigate drug addiction, we evaluated whether contingent versus non-contingent cocaine self-administration during adolescence modulates its rewarding threshold in adulthood evaluated by conditioned place preference (CPP). Cocaine self-administration during adolescence increases the rewarding threshold in adulthood; CPP for cocaine was observed at the higher (20 mg/kg), but not at the lower (10 mg/kg), dose employed. Rats exposed to either contingent or non-contingent cocaine during adolescence exhibited the same behavior in the CPP paradigm suggesting that, under our experimental conditions, cocaine rewarding properties are shaped by the psychostimulant itself and not by its motivational effects. From a mechanistic standpoint, the preference for the 20 mg/kg cocaine-paired side in a CPP paradigm appears to depend, at least partially, upon the formation of GluA2-lacking Ca²⁺ -permeable AMPA receptors and the consequent increase of αCaMKII activity in the NAc, both of which are instead reduced when the 10 mg/kg dose was used. In conclusion, contingent or non-contingent cocaine exposure during adolescence desensitizes adult animals to a rewarding dose of cocaine (10 mg/kg) elevating the rewarding threshold necessary (20 mg/kg) to drive conditioned place preference, an effect that may predispose to higher consumption of cocaine during adulthood.

Impact of salivary contamination during placement of implants with simultaneous bony augmentation in iliac bone in sheep

Our aim was to investigate the possible impact of contamination with saliva on osseointegration during placement of implants with simultaneous bone augmentation. Six hemispheric shape bone defects (8mm in diameter×4mm deep) were prepared in each iliac bone of six sheep. A dental implant (2.9mm in diameter×10mm long) was placed in the centre of each defect, and then pairs of defects were filled with one of the following bone augmentation materials: autogenous bone, autogenous bone plus bovine bone, or resorbable biphasic ceramic bone substitute. One site in each augmentation group was impregnated with saliva (contaminated group), while the other was not (non-contaminated group). Bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO) within implant threads were measured after a healing period of five weeks, both in respect of the implant inserted in the augmented bone and in that inserted in the residual bone. Overall results showed that there was a significant difference between the contaminated and non-contaminated group for BIC in the augmented implant (p=0.028), while there were no significant differences in the implant in residual bone (p=0.722). For BAFO, there were no significant differences between the contaminated and non-contaminated groups among the different augmentation materials. The results showed that contamination with saliva during placement of an implant with simultaneous bone augmentation had a serious deleterious effect on osseointegration of the aspect of the implant within the augmented defect. Contamination with saliva during placement of an implant with simultaneous bone augmentation should therefore be avoided.

Evidence-based dentistry: what's new?

The importance of evidence for every branch of medicine in teaching in order to orient the practitioners among the great amount of most actual scientific information's, and to support clinical decisions, is well established in health care, including dentistry. The practice of evidence-based medicine is a process of lifelong, self-directed, problem-based learning which leads to the need for clinically important information about diagnosis, prognosis, therapy and other clinical and health care issues. Nowadays the practice of dentistry is becoming more complex and challenging because of the continually changing in dental materials and equipments, an increasingly litigious society, an increase in the emphasis of continuing professional development, the information explosion and the consumer movement associated with advances on the Internet. The need for reliable information and the electronic revolution have come together to allow the "paradigm shift" towards evidence-based health care. Recent years have seen an increase in the importance of evidence-based dentistry, aiming to reduce to the maximum the gap between clinical research and real world dental practice. Aim of evidence-based practice is the systematic literature review, which synthesizes the best evidences and provides the basis for clinical practice guidelines. These practice guidelines give a brief review of what evidence-based dentistry is and how to use it.

The IGF-I/IGFBP-3 system in gingival crevicular fluid and dependence on application of fixed force

BACKGROUND

During application of orthodontic force on the tooth, various molecular parameters associated with tissue remodeling are changed. IGF-I is a regulatory protein produced during periodontal regeneration. IGF binding proteins-3 (IGFBP-3), a specific IGF-I binding protein, is the major regulatory factor of IGF-I activity.

OBJECTIVES

We tested the hypothesis that changes in the IGF-I/ IGFBP-3 system occur during fixed force application to the tooth and that these changes are detectable in the gingival crevicular fluid (GCF).

METHODS

IGFBP-3 and IGF-I secretion into gingival crevicular fluid (GCF) was analyzed by Western blotting and immunoradiometric assay (IRMA), respectively, in GCF of 6 healthy subjects just prior to and during orthodontics treatment using fixed appliances.

RESULTS

We observed a significant time-dependent decrease of IGFBP-3 content in GCF during orthodontic treatment (4 h and 10 days). Reduction in levels of intact, glycosylated 47 kDa form of IGFBP-3 was associated with its degradation and the appearance of intermediate breakdown products. IGF-I levels were significantly increased 4 h after application of orthodontic force, while they were significantly reduced 10 days after the start of treatment.

CONCLUSIONS

IGFBP-3 secretion into GCF and its molecular structure are modified by the fixed force of orthodontic treatment. Alterations in IGFBP-3 appear to be unrelated to the binding to IGF-I, suggesting an IGF-independent role of this binding protein in tooth movement.

Accelerated hyperfractionated total-lymphoid irradiation, high-dose chemotherapy, and autologous bone marrow transplantation for refractory and relapsing patients with Hodgkin's disease

PURPOSE

To evaluate the feasibility and therapeutic effect of accelerated hyperfractionated total-lymphoid irradiation (TLI), high-dose chemotherapy, and autologous bone marrow transplantation (AuBMT) in patients with relapsing or chemotherapy-resistant Hodgkin's disease (HD).

PATIENTS AND METHODS

Forty-seven patients with HD who either relapsed after chemotherapy (n = 19), or failed to respond (n = 28) to at least two regimens of combination chemotherapy were studied. No patient received prior radiation therapy (RT). Treatment started with reinduction with standard-dose chemotherapy, followed by involved-field irradiation (15 Gy) to areas of relapsed or persistent disease and TLI (20.04 Gy given in 1.67 Gy fractions three times per day for 4 days). Subsequently, patients received etoposide and high-dose cyclophosphamide, followed by infusion of unpurged autologous bone marrow. All surviving patients had a minimum follow-up duration of 1 year. The median follow-up duration for survivors was 40+ months, and the maximum follow-up duration was 80+ months.

RESULTS

Of the 47 patients treated, eight (17%) died of toxicity during the peritransplant period. Twenty-nine of the remaining 39 assessable patients (74%) attained a complete response (CR), while 10 remained with residual disease and progressed early after AuBMT. Four of the CR patients (14%) relapsed and 25 patients remained alive and free of disease. The actuarial disease-free survival (DFS) rate for the entire group at 6.5 years was 50%. Patients who received the protocol for relapsing HD had a significantly better DFS rate (79%) compared with patients treated for continuous refractory disease (DFS, 33%; P < .03).

CONCLUSION

Previously unirradiated patients with relapsing or chemotherapy-resistant HD who have exhausted conventional chemotherapy may still respond to an aggressive therapeutic approach consisting of accelerated hyperfractionated TLI, high-dose chemotherapy, and AuBMT rescue. This program offers a potential for long-term DFS to approximately one half of patients who would otherwise have a dismal prognosis with standard-dose salvage therapy.

Role of granulocyte-macrophage colony stimulating factor (GM-CSF) after autologous bone marrow transplantation for Hodgkin's disease

Use of growth factors to augment hematopoietic recovery after cytotoxic therapy is a useful method for dose intensification. We wanted to evaluate the clinical and cost-effectiveness of granulocyte-macrophage colony stimulating factor (GM-CSF; Leucomax) in patients undergoing autologous bone marrow transplantation (ABMT) for Hodgkin's disease. Twenty-four patients with Hodgkin's disease were treated with high-dose chemotherapy and ABMT. Patients were then randomized in a double-blind manner to receive GM-CSF intravenously (10 micrograms/kg) over 6 h or placebo until the absolute neutrophil count (ANC) was greater than 1000/mm3 for 3 days. The study medication was stopped after 30 days. Patients treated with GM-CSF (n = 12) had shorter periods of neutropenia (median duration of an ANC of less than 1000 cells/mm3, 16 versus 27 days on placebo; p = 0.23), shorter periods of platelet-transfusion dependency (median duration, 13.5 versus 21 days on placebo; p = 0.03), shorter hospitalizations (median hospital stay, 32 versus 40.5 days on placebo; p = 0.0004). Other clinical outcomes, such as frequency and severity of toxicities, development of pneumonia or infection, in-hospital death, and response rate were similar in the two groups. Actuarial long-term disease free survival was 58% for patients treated with GM-CSF and 50% for patients who received placebo after 38 months of follow up (p = 0.6).(ABSTRACT TRUNCATED AT 250 WORDS)

Treatment of patients with relapsed and resistant non-Hodgkin's lymphoma using total body irradiation, etoposide, and cyclophosphamide and autologous bone marrow transplantation

PURPOSE

Patients with non-Hodgkin's lymphoma (NHL) who do not achieve a complete response (CR) after induction chemotherapy or who relapse after achieving a CR are rarely cured of their disease by the usual salvage therapy. Success of high-dose cytotoxic therapy with an autologous bone marrow transplant (AuBMT) is limited. We describe the results of a prospective single-institution study using a new conditioning regimen for patients with relapsed or resistant NHL who underwent AuBMT.

PATIENTS AND METHODS

Forty-four patients were reinduced with cytotoxic therapy and then evaluated for response. All patients received the conditioning regimen of hyperfractionated total body irradiation (TBI), etoposide (VP-16), and cyclophosphamide (CTX) followed by autologous bone marrow reinfusion.

RESULTS

The disease-free survival (DFS) rate was 57% with a median follow-up of 42+ months. The only variable significantly associated with DFS was the patient's remission status at AuBMT. Patients who underwent AuBMT in CR had a DFS of 80%, whereas patients who underwent AuBMT in partial response (PR) or with progressive disease (PD) had a DFS of 60% and 11%, respectively (P = .002). The major toxicity was hemorrhage at the site of bulky disease, especially in patients with residual mediastinal and/or pulmonary disease.

CONCLUSION

Planned reinduction cytotoxic therapy followed by TBI, VP-16, and CTX with AuBMT is an effective treatment for patients with relapsed and resistant NHL.

The usefulness of ultrasound in the post operative management of hydronephrosis

The renal tracts of thirty-four children aged between 6 months and 12 years, with vesico-ureteric reflux or obstructive hydronephrosis were examined by ultrasound (US) pre and post operatively, in an attempt to determine the validity of US as an alternative means of diagnostic imaging. The results show the technique to be both accurate and reproducible and we therefore believe that US is a reliable procedure for monitoring urinary tract morphology in patients with hydronephrosis or in the post operative assessment of vesicoureteric reflux.

[Cryoglobulinemia syndrome and liver diseases. Case reports]

Six cases of an association of liver disease with a cryoglobulinaemia syndrome are described. An account of their clinical, body fluid and anatomopathological pictures is followed by a discussion of their possible causes in the light of the relevant literature. It is felt that no assessment can be made of the primary nature of either disease in associations of this kind. In addition to cases in which prior liver disease or exposure to hepatitis virus can be shown, in fact, there are other situations in which liver disease was present before the manifestation of cryoglobulinaemia. Repeated antigen stimulus triggers the antibody response leading to the formation of cryoprecipitating complexes. In most cases, the nature of such antigen is not known, since HB virus or any other virus, bacterial product, or cell catabolism product either eliminated in insufficient quantities, or produced in abnormal quantities, may be responsible.