Liposome-encapsulated amphotericin B for treatment of disseminated candidiasis in neutropenic mice

The relative efficacies of free amphotericin B (Amp B) and liposome-encapsulated Amp B (L-AmpB) in the treatment of established Candida albicans infection in mice rendered neutropenic with cyclophosphamide were studied. AmpB was entrapped in multilamellar liposomes composed of dimyristoyl phosphatidylcholine and dimyristoyl phosphatidylglycerol in a molar ratio of 7:3. Infected mice treated with single doses of 3 mg L-AmpB/kg of body weight had an increased survival time compared with those injected with either single (dose, 0.8 mg/kg) or multiple doses (dose, 0.8 mg/kg daily for five days) of free AmpB. When treatment was delayed beyond three days postinfection, neither single nor multiple doses of free AmpB resulted in increased survival, whereas treatment with single-dose L-AmpB (dose, 4 mg/kg) showed efficacy when delayed as much as four days postinfection. Five days postinfection only higher doses (dose, 5.6 mg-11.2 mg/kg) of L-AmpB improved survival time and the renal impairment present in the infected animals. These data provided a rational basis for using high-dose L-AmpB to treat fungal diseases in humans, particularly in neutropenic patients.     

The microinjection of AMPA receptor antagonist into the accumbens shell, but not into the accumbens core, induces anxiolysis in an animal model of anxiety

This study investigated the effect of the AMPA receptor antagonist 6,7-dinitroquinoxaline-2,3-dione (DNQX) microinjected into the core and shell sub-regions of the accumbens nucleus (Acb), on the level of fear/anxiety and emotional learning, in female rats submitted to the elevated plus-maze (EPM), an animal model of anxiety. Bilateral microinjections of DNQX (330 and 660 ng) into the Acb shell (AP, +1.08 to +2.16) induced an anxiolytic-like effect in relation to rats microinjected with vehicle, since there was an increased percentage of entries in the open arms of the maze. The 660 ng DNQX microinjection into the Acb shell also increased the percentage of entries into the open arms in relation to 660 ng DNQX microinjection into the Acb core. Prior DNQX microinjections in both core and shell sub-regions of the Acb failed to impair the emotional learning, since the animals exhibited an increase of the open arm avoidance on EPM Trial 2 in relation to EPM trial 1. DNQX microinjections into both sub-regions of the Acb did not change the number of entries into the enclosed arms, either in the EPM Trial 1 or in the EPM Trial 2, which indicates an absence of drug-induced locomotor impairment. Similarly, DNQX microinjections into both sub-regions of the Acb failed to alter the total arm entries, rearing, grooming and head-dipping frequency. The anxiolytic-like effect induced by DNQX suggests that the AMPA receptor in the Acb shell, but not in the Acb core, may underlie anxiety regulation in the EPM.     

Nicotine-induced damage affects gingival fibroblasts in the gingival tissue of rats

Background: Very limited information is available from in vivo studies about whether smoking and/or nicotine affect gingival tissues in the absence of plaque. The purpose of this study is to evaluate the effect of the systemic administration of nicotine in the proliferation and counting of fibroblast‐like cells in the gingival tissue of rats. Methods: Thirty adult male Wistar rats were randomly assigned into two groups to receive subcutaneous injections of a saline solution (control group = group C) or nicotine solution (group N; 3 mg/kg) twice a day. The animals were euthanized 37, 44, or 51 days after the first subcutaneous injection. Specimens were routinely processed for serial histologic sections. Five fields of view in the connective tissue adjacent to the gingival epithelium and above the alveolar bone crest of the maxillary first molar were selected for the counting of fibroblast‐like cells. Data were statistically analyzed (P <0.05). Results: The intergroup analysis detected a lower number of fibroblast‐like cells in group N compared to group C on days 37 (2.65 ± 1.41 and 6.67 ± 3.25, respectively), 44 (2.70 ± 1.84 and 8.57 ± 2.37, respectively), and 51 (2.09 ± 1.41 and 7.49 ± 2.60, respectively) (P <0.05). The quantification of fibroblast‐like cells showed no significant difference (P >0.05) in the intragroup analysis of control and nicotine throughout experimental periods. In the intergroup analysis, group N had reduced proliferating cell nuclear antigen–positive fibroblasts compared to group C in all periods (P <0.05). Conclusion: The daily systemic administration of nicotine negatively affected, in vivo, the number and proliferation of fibroblast‐like cells in the gingival tissue of rats.     

IN VITRO ASSESSMENT OF AN EXPERIMENTAL COAT APPLIED OVER FLUORIDE VARNISHES

Objective:

The time of contact between the product and enamel surface is important in ensuring the efficacy of fluoride varnishes. Thus, some alternatives could avoid fluoride loss to saliva and improve the anticariogenic action of the product. This study evaluated the effect of an experimental coat on the anticariogenic action of fluoride varnishes.

Material and Methods:

Enamel bovine blocks were selected by evaluating surface microhardness and randomized into five groups (n=24): placebo, Duraphat™, Duraphat™ with coat, Duofluorid™ and Duofluorid™ with coat. Twelve blocks from each group were used to analyze calcium fluoride (CaF₂) formed on enamel after treatment. The other 12 blocks were subjected to pH cycling for 7 days. The varnishes were kept on enamel for 6 h. Next, the percentage change of surface microhardness (%SMHC) and mineral loss (ΔZ) were calculated. CaF₂ retained and fluoride present in the pH-cycled solutions were also measured.

Results:

The use of the coat did not decrease %SMHC and ΔZ, but all fluoride varnishes had better results when compared to the placebo (ANOVA and Kruskal-Wallis, respectively). The values from CaF₂ formed were higher compared to the values of CaF₂ retained (non-paired t test, p<0.05). There was a trend to decrease the amount of F in the solutions at the end of pH cycling (Kruskal-Wallis, p<0.05).

Conclusions:

Although the experimental coat increased the formation of CaF₂ on the enamel surface, it did not significantly improve the anticariogenic action of fluoride varnishes.     

Discovery and Validation of a Urinary Exosome mRNA Signature for the Diagnosis of Human Kidney Transplant Rejection

BackgroundDeveloping a noninvasive clinical test to accurately diagnose kidney allograft rejection is critical to improve allograft outcomes. Urinary exosomes, tiny vesicles released into the urine that carry parent cells’ proteins and nucleic acids, reflect the biologic function of the parent cells within the kidney, including immune cells. Their stability in urine makes them a potentially powerful tool for liquid biopsy and a noninvasive diagnostic biomarker for kidney-transplant rejection.MethodsUsing 192 of 220 urine samples with matched biopsy samples from 175 patients who underwent a clinically indicated kidney-transplant biopsy, we isolated urinary exosomal mRNAs and developed rejection signatures on the basis of differential gene expression. We used crossvalidation to assess the performance of the signatures on multiple data subsets.ResultsAn exosomal mRNA signature discriminated between biopsy samples from patients with all-cause rejection and those with no rejection, yielding an area under the curve (AUC) of 0.93 (95% CI, 0.87 to 0.98), which is significantly better than the current standard of care (increase in eGFR AUC of 0.57; 95% CI, 0.49 to 0.65). The exosome-based signature’s negative predictive value was 93.3% and its positive predictive value was 86.2%. Using the same approach, we identified an additional gene signature that discriminated patients with T cell–mediated rejection from those with antibody-mediated rejection (with an AUC of 0.87; 95% CI, 0.76 to 0.97). This signature’s negative predictive value was 90.6% and its positive predictive value was 77.8%.ConclusionsOur findings show that mRNA signatures derived from urinary exosomes represent a powerful and noninvasive tool to screen for kidney allograft rejection. This finding has the potential to assist clinicians in therapeutic decision making.     

Comparison of CT and PET/CT for biopsy guidance in oncological patients

Purpose

To compare FDG PET/CT and CT for the guidance of percutaneous biopsies with histological confirmation of lesions.

Methods

We prospectively evaluated 323 patients of whom 181 underwent FDG PET/CT-guided biopsy (total 188 biopsies) and 142 underwent CT-guided biopsy (total 146 biopsies). Biopsies were performed using the same PET/CT scanner with a fluoroscopic imaging system. Technical feasibility, clinical success and complication rates in the two groups were evaluated.

Results

Of the 188 biopsies with PET/CT guidance, 182 (96.8%) were successful with conclusive tissue samples obtained and of the 146 biopsies with CT guidance, 137 (93.8%) were successful. Therefore, 6 of 188 biopsies (3.1%) with PET/CT guidance and 9 of 146 (6.1%) with CT guidance were inconclusive (p?=?0.19). Due to inconclusive histological results, 4 of the 188 lesions (2.1%) were rebiopsied with PET/CT guidance and 3 of 146 lesions (2.0%) were rebiopsied with CT guidance. Histology demonstrated that 142 of 188 lesions (75.5%) were malignant, and 40 (21.2%) were benign in the PET/CT-guided group, while 89 of 146 lesions (60.9%) were malignant and 48 (32.8%) were benign in the CT-guided group (p?=?0.004 and 0.01, respectively). Patients with a histological diagnosis of benign lesion had no recurrence of disease with a minimum of 6 months follow-up. Of the 188 PET/CT-guided biopsies, 6 (3.1%) were repeat biopsies due to a previous nondiagnostic CT-guided biopsy performed in a different diagnostic centre. The interval between the two biopsies was less than a month in all cases. Histology revealed five malignant lesions and one benign lesion among these. The complication rate in the PET/CT-guided biopsy group was 12.7% (24 of 188), while in the CT-guided group, was 9.5% (14 of 146, p?=?0.26). Therefore, there was no significant difference in complication rates between PET/CT and CT guidance.

Conclusion

PET/CT-guided biopsy is already known to be a feasible and accurate method in the diagnostic work-up of suspected malignant lesions. This prospective analysis of a large number of patients demonstrated the feasibility and advantages of using PET/CT as the imaging method of choice for biopsy guidance, especially where FDG-avid foci do not show corresponding lesions on the CT scan. There were no significant differences in the ability to obtain a diagnostic specimen or in the complication rates between PET/CT and CT guidance.

     

Valeriana officinalis does not alter the orofacial dyskinesia induced by haloperidol in rats: role of dopamine transporter

Chronic treatment with classical neuroleptics in humans can produce a serious side effect, known as tardive dyskinesia (TD). Here, we examined the effects of V. officinalis, a medicinal herb widely used as calming and sleep-promoting, in an animal model of orofacial dyskinesia (OD) induced by long-term treatment with haloperidol. Adult male rats were treated during 12 weeks with haloperidol decanoate (38 mg/kg, i.m., each 28 days) and with V. officinalis (in the drinking water). Vacuous chewing movements (VCMs), locomotor activity and plus maze performance were evaluated. Haloperidol treatment produced VCM in 40% of the treated rats and the concomitant treatment with V. officinalis did not alter either prevalence or intensity of VCMs. The treatment with V. officinalis increased the percentage of the time spent on open arm and the number of entries into open arm in the plus maze test. Furthermore, the treatment with haloperidol and/or V. officinalis decreased the locomotor activity in the open field test. We did not find any difference among the groups when oxidative stress parameters were evaluated. Haloperidol treatment significantly decreased [(3)H]-dopamine uptake in striatal slices and V. officinalis was not able to prevent this effect. Taken together, our data suggest a mechanism involving the reduction of dopamine transport in the maintenance of chronic VCMs in rats. Furthermore, chronic treatment with V. officinalis seems not produce any oxidative damage to central nervous system (CNS), but it also seems to be devoid of action to prevent VCM, at least in the dose used in this study.     

The role of the irritative zone and of the number and distribution of calcifications in the severity of epilepsy associated with intracranial calcifications

OBJECTIVE: To determine the influence of the location of the irritative zone, and the number and the distribution of the intracranial calcifications in the severity of epilepsy associated with intracranial calcifications. METHOD: We studied 47 patients with epilepsy and intracranial calcifications, 24 with normal (Group A) and 23 with abnormal interictal EEGs (Group B), a control group (n=21) with abnormal interictal EEGs and normal CT-scans (Group C). Clinical, electroencephalographic and neuroradiological features were compared among groups. RESULTS: Temporal lobe interictal EEG abnormalities were found in 23/24 Group B patients, and in all Group C patients. Most Group B and Group C patients presented temporal lobe seizure symptomatology, whereas in most Group A patients symptomatology was rolandic (p=0.0001). Epilepsy was more severe in Group B and Group C patients than in Group A patients (p=0.0001 and p=0.0054). No relationship was found between the number of calcifications and epilepsy severity. CONCLUSION: An irritative zone at the temporal lobe is more relevant in determining the severity, symptomatology and frequency of seizures than the number and location of calcifications.     

Acute appendicitis. Experimental model in rabbits

The evolving phases of acute appendicitis were studied experimentally. Sixty female rabbits (Oryctogalus cuniculus) of New Zealand lineage weighing about 2510 to 3040 g were divided in two groups: a control group and experimental group. The experimental group was divided into three subgroups for observation after 12, 24 and 48 hours of the operation, that consisted on a 4-0 polypropylene circular suture at 8 cm from the distal part of the cecal appendix. The control group was sham operated. The macroscopic exam (increase of the appendix volume, necrosis, perfuration, adherence and secretion in the abdominal cavity) and the microscopic finding showed a progression in the anatomopathological alterations. There was a close relationship between the histopathological findings and time after the appendiceal obstruction. We conclude that the method causes acute appendicitis and that the anathomo pathological alterations depends on the time elapsed between the operation and the postoperation findings.