In vitro antimicrobial activity of auxiliary chemical substances and natural extracts on Candida albicans and Enterococcus faecalis in root canals

Objective:

The aim of this study was to evaluate the antimicrobial activity of auxiliary chemical substances and natural extracts on Candida albicans and Enterococcus faecalis inoculated in root canals.

Material and Methods:

Seventy-two human tooth roots were contaminated with C. albicans and E. faecalis for 21 days. The groups were divided according to the auxiliary chemical substance into: G1) 2.5% sodium hypochlorite (NaOCl), G2) 2% chlorhexidine gel (CHX), G3) castor oil, G4) glycolic Aloe vera extract, G5) glycolic ginger extract, and G6) sterile saline (control). The samples of the root canal were collected at different intervals: confirmation collection, at 21 days after contamination; 1^st collection, after instrumentation; and 2^nd collection, seven days after instrumentation. Microbiological samples were grown in culture medium and incubated at 37º C for 48 hours.

Results:

The results were submitted to the Kruskal-Wallis and Dunn (5%) statistical tests. NaOCl and CHX completely eliminated the microorganisms of the root canals. Castor oil and ginger significantly reduced the number of CFU of the tested bacteria. Reduction of CFU/mL at the 1^st and 2^nd collections for groups G1, G2, G3 and G4 was greater in comparison to groups G5 and G6.

Conclusion:

It was concluded that 2.5% sodium hypochlorite and 2% chlorhexidine gel were more effective in eliminating C. albicans and E. faecalis, followed by the castor oil and glycolic ginger extract. The Aloe vera extract showed no antimicrobial activity.     

Manganese-Enhanced Magnetic Resonance Imaging Detects Declining Pancreatic β-Cell Mass in a Cyclophosphamide-Accelerated Mouse Model of Type 1 Diabetes

Currently, there is no ideal noninvasive method to quantify the progressive loss of pancreatic β-cell mass (BCM) that occurs in type 1 diabetes. Magnetic resonance imaging has detected gross differences in BCM between healthy and diabetic mice using the contrast agent manganese, which labels functional β-cells and increases the water proton relaxation rate (R1), but its ability to measure gradations in BCM during disease progression is unknown. Our objective was to test the hypothesis that measurements of the manganese-enhanced pancreatic R1 could detect decreasing BCM in a mouse model of type 1 diabetes. We used cyclophosphamide-accelerated BDC2.5 T-cell receptor transgenic nonobese diabetic mice, which experience development of type 1 diabetes during a 7-day time period after cyclophosphamide injection, whereas transgene-negative mice do not. We measured the manganese-enhanced pancreatic R1 before cyclophosphamide injection (day 0) and on days 3, 4, 5, and 7 afterward. Pancreatic R1 remained constant in transgene-negative mice and decreased stepwise day-to-day in transgene-positive mice, mirroring their loss of BCM, confirmed by pancreatic insulin measurements and histology. Changes in R1 in transgene-positive mice occurred before elevations in blood glucose, a clinical indicator of diabetes, suggesting potential for early noninvasive detection of changes in functional BCM.Type 1 diabetes is a metabolic disorder characterized by an inability to maintain normoglycemia. It occurs due to the autoimmune destruction of the insulin-producing pancreatic β-cells, which are diffusely dispersed throughout the pancreas in the islets of Langerhans and represent approximately 1–2% of the pancreatic mass (1). The etiology of this destructive autoimmune process remains largely unknown, although key cellular events include early functional disruption and progressive inflammatory β-cell destruction (2–4). Currently, there is no ideal method for noninvasively measuring changes in functional β-cell mass (BCM), which would be valuable for assessing diabetes progression, following therapeutic response, or for evaluating the viability of transplanted pancreatic islets (5). Provocative testing with β-cell secretogogues, the gold standard for detection of β-cell loss, is insensitive to early stages of the disease, and although biopsy techniques might be useful in monitoring the status of clustered transplanted islets in defined sites, this approach is impractical for dispersed islet transfers or in the diagnosis and staging of type 1 diabetes.Recently, noninvasive imaging techniques such as single photon emission computed tomography (SPECT) (6), positron emission tomography (7,8), bioluminescence imaging (9), and magnetic resonance imaging (MRI) (10–13) have shown promise in detecting BCM. These techniques, however, have limitations. Positron emission tomography and single photon emission computed tomography use ionizing radiation, have relatively low spatial resolution, and currently use non-ideal β-cell–specific radiotracers; bioluminescence imaging has limited spatial resolution and is not translatable to humans; and no technique has proven the ability to detect small gradations in BCM. Manganese (Mn²⁺)-enhanced MRI (MEMRI) may prove an attractive method for assessing functional BCM, because the mechanism by which Mn²⁺ ions label β-cells is inherently linked to β-cell function and may be translatable to human imaging. Manganese ions enter β-cells through voltage-gated calcium channels (10) and increase the nuclear magnetic resonance water proton longitudinal relaxation rate constant (R1) proportionally with Mn²⁺ concentration. Recent data supporting this mechanism showed that glucose stimulation before MEMRI increased pancreatic R1, and that this effect is essentially abolished with calcium channel blockade (12). Thus, the glucose-stimulated Mn²⁺-enhanced pancreatic R1 has been interpreted as a measurement of functional BCM (12). MEMRI studies previously have detected gross decreases in BCM in mice in a streptozotocin-induced model of type 1 diabetes (11–13), a model characterized by a precipitous loss of BCM after streptozotocin injection. The sensitivity of MEMRI, or any other imaging modality, to detect gradual changes in functional BCM that occur during the progression of diabetes has not yet been demonstrated, although the ability to measure gradations in BCM is necessary for clinical translation of any technique that assesses functional BCM.To test the hypothesis that MEMRI can detect gradations in BCM, we performed MRI on cyclophosphamide-accelerated BDC2.5 T-cell receptor transgenic mice on a nonobese diabetic background (NOD-BDC2.5) (14–16). After injection of cyclophosphamide, NOD-BDC2.5 mice expressing a transgenic T-cell receptor (Tg⁺ mice) exhibit progressive autoimmune β-cell destruction, with virtually 100% of mice becoming overtly diabetic within 7 days of cyclophosphamide injection (14). Mice lacking the transgenic T-cell receptor (Tg⁻ mice) do not have development of diabetes within this time frame after cyclophosphamide injection. Because of the kinetics and reproducibility of diabetes progression, this model allows the investigation of the ability to detect small decrements in functional BCM.     

Enteral stenting versus gastrojejunostomy for palliation of malignant gastric outlet obstruction

Background and aims

Endoscopic placement of enteral self-expandable metallic stents is an alternative to surgical gastrojejunostomy (GJ) for palliation of malignant gastric outlet obstruction (GOO). Factors associated with clinical outcomes are not known. The aims of this study are to compare the overall complication rate and effectiveness (duration of oral intake) between endoscopic stenting (ES) and GJ in patients with GOO and identify predictors of clinical outcomes.

Patients and methods

This was a retrospective cohort study at a single tertiary academic center. Patients who underwent ES or GJ for treatment of GOO between 1/2001 and 12/2010 were identified using an institutional claims database. The electronic medical records for each patient were reviewed. Univariate and multivariate logistic regression analyses were performed to study the association of treatment outcomes with patient factors and cancer therapy.

Results

120 patients had ES while 227 had GJ. Technical success was higher for GJ (99 vs. 96 %, p = 0.004). Complication rates were higher in the GJ group (22.10 vs. 11.66 %, p = 0.02). Reintervention was more common with ES [adjusted odds ratio (OR) 9.18, p < 0.0001]. Mean length of hospital stay (LOHS) was shorter (adjusted p = 0.005) in the ES compared with the GJ group. However, mean hospital charges, including reinterventions, were greater in the ES group (US $34,250 vs. US $27,599, p = 0.03). ES and GJ had comparable reintervention-free time in patients who had reintervention (88 vs. 106 days, respectively, p = 0.79). Chemotherapy [adjusted hazard ratio (HR) 3 > 0.57, p = 0.04] and radiation therapy (adjusted HR 0.35, p = 0.03) were associated with significantly longer duration of oral intake after ES or GJ.

Conclusion

ES is associated with fewer complications, shorter LOHS, but higher reintervention rates and overall charges.     

Endoscopic ultrasound (EUS)-guided fiducial placement allows localization of small neuroendocrine tumors during parenchymal-sparing pancreatic surgery

Background

Parenchymal-sparing pancreatic surgery is ideal for lesions such as small pancreatic neuroendocrine tumors (PanNET). However, precise localization of these small tumors at surgery can be difficult. The placement of fiducials under endoscopic ultrasound (EUS) guidance (EUS-F) has been used to direct stereotactic radiation therapy for pancreatic adenocarcinoma. This report describes two cases in which placement of fiducials was used to guide surgical resection. This study aimed to assess the feasibility, safety, and efficacy of using EUS-F for intraoperative localization of small PanNETs.

Methods

A retrospective study analyzed two consecutive patients with small PanNETs who underwent EUS-F followed by enucleation in a tertiary-care referral hospital. The following features were examined: technical success and complication rates of EUS-F, visibility of the fiducial at the time of surgery, and fiducial migration.

Results

In the study, EUS-F was performed for two female patients with a 7-mm and a 9-mm PanNET respectively in the uncinate process and neck of the pancreas. In both patients, EUS-F was feasible with two Visicoil fiducials (Core Oncology, Santa Barbara, CA, USA) placed either within or adjacent to the tumors using a 22-gauge Cook Echotip needle. At surgery, the fiducials were clearly visible on intraoperative ultrasound, and both the tumor and the fiducials were successfully enucleated in both cases. No complications were associated with EUS-F, and no evidence of pancreatitis was shown either clinically or on surgical pathology. This investigation had the limitations of a small single-center study.

Conclusions

For patients undergoing enucleation, EUS-F is technically feasible and safe and aids intraoperative localization of small PanNETs.     

Advanced Imaging Modalities in Early Stage Breast Cancer: Preoperative Use in the United States Medicare Population

Background

Guidelines for breast cancer staging exist, but adherence remains unknown. This study evaluates patterns of imaging in early stage breast cancer usually reserved for advanced disease.

Methods

Surveillance Epidemiology, and End Results data linked to Medicare claims from 1992–2005 were reviewed for stage I/II breast cancer patients. Claims were searched for preoperative performance of computed tomography (CT), positron emission tomography (PET), bone scans, and brain magnetic resonance imaging (MRI) (“advanced imaging”).

Results

There were 67,874 stage I/II breast cancer patients; 18.8 % (n = 12,740) had preoperative advanced imaging. The proportion of patients having CT scans, PET scans, and brain MRI increased from 5.7 % to 12.4 % (P < 0.0001), 0.8 % to 3.4 % (P < 0.0001) and 0.2 % to 1.1 % (P = 0.008), respectively, from 1992 to 2005. Bone scans declined from 20.1 % to 10.7 % (P < 0.0001). “Breast cancer” (174.x) was the only diagnosis code associated with 62.1 % of PET scans, 37.7 % of bone scans, 24.2 % of CT, and 5.1 % of brain MRI. One or more symptoms or metastatic site was suggested for 19.6 % of bone scans, 13.0 % of CT, 13.0 % of PET, and 6.2 % of brain MRI. Factors associated (P < 0.05) with use of all modalities were urban setting, breast MRI and ultrasound. Breast MRI was the strongest predictor (P < 0.0001) of bone scan (odds ratio [OR] 1.63, 95 % confidence interval [CI] 1.44–1.86), Brain MRI (OR 1.74, 95 % CI 1.15–2.63), CT (OR 2.42, 95 % CI 2.12–2.76), and PET (OR 5.71, 95 % CI 4.52–7.22).

Conclusions

Aside from bone scans, performance of advanced imaging is increasing in early stage Medicare breast cancer patients, with limited rationale provided by coded diagnoses. In light of existing guidelines and increasing scrutiny about health care costs, greater reinforcement of current indications is warranted.     

Speech acts after mild or severe childhood head injury

Children with head injury have impairments in pragmatic language. We investigated speech acts, a form of pragmatic communication, after mild or severe childhood head injury in relation to two linguistic constituents of speech acts competence (lexical-semantic knowledge, pragmatic inference) and two cognitive resources (world knowledge, working memory). Children with head injury had difficulty producing speech acts, and the magnitude of this deficit varied with head injury severity. Within the head injury group, semantic reference and information were unimportant for speech acts, which were, however, significantly predicted by pragmatic inference and working memory. The results are discussed in relation to three general issues: the effect of severity of childhood head injury on linguistic and cognitive morbidity; the relation between semantic reference, pragmatic inference and more general cognitive resources in the production of speech acts; and why semantic competence at a lexical level may not be sufficient for the production of pragmatic utterances.