A comparative in vitro toxicity assessment of electronic vaping product e-liquids and aerosols with tobacco cigarette smoke.

The use of electronic vaping products (EVPs) continues to increase worldwide among adult smokers in parallel with accumulating information on their potential toxicity and relative safety compared to tobacco smoke. At this time, in vitro assessments of many widely available EVPs are limited. In this study, an in vitro battery of established assays was used to examine the cytotoxic (Neutral red uptake), genotoxic (In vitro micronucleus) and mutagenic (Bacterial reverse mutation) responses of two commercial EVPs (blu GO™ disposable and blu PLUS+™ rechargeable) when compared to smoke from a reference cigarette (3R4F). In total, 12 commercial products were tested as e-liquids and as aerosols. In addition, two experimental base liquids containing 1.2% and 2.4% nicotine were also assessed to determine the effect of flavour and nicotine on all three assays. In the bacterial reverse mutation (Ames) and in vitro micronucleus (IVM) assays, exposures to e-liquids and EVP aerosols, with and without nicotine and in a range of flavourings, showed no mutagenic or genotoxic effects compared to tobacco smoke. The neutral red uptake (NRU) assay showed significantly reduced cytotoxicity (P < .05) for whole undiluted EVP aerosols compared to tobacco smoke, which by contrast was markedly cytotoxic even when diluted. The reduced in vitro toxicological responses of the EVPs add to the increasing body of scientific weight-of-evidence supporting the role of high-quality EVPs as a harm reduction tool for adult smokers.

Passage-dependent relationship between mesenchymal stem cell mobilization and chondrogenic potential.

OBJECTIVE: Galvanotaxis, the migratory response of cells in response to electrical stimulation, has been implicated in development and wound healing. The use of mesenchymal stem cells (MSCs) from the synovium (synovium-derived stem cells, SDSCs) has been investigated for repair strategies. Expansion of SDSCs is necessary to achieve clinically relevant cell numbers; however, the effects of culture passage on their subsequent cartilaginous extracellular matrix production are not well understood. METHODS: Over four passages of SDSCs, we measured the expression of cell surface markers (CD31, CD34, CD49c, CD73) and assessed their migratory potential in response to applied direct current (DC) electric field. Cells from each passage were also used to form micropellets to assess the degree of cartilage-like tissue formation. RESULTS: Expression of CD31, CD34, and CD49c remained constant throughout cell expansion; CD73 showed a transient increase through the first two passages. Correspondingly, we observed that early passage SDSCs exhibit anodal migration when subjected to applied DC electric field strength of 6 V/cm. By passage 3, CD73 expression significantly decreased; these cells exhibited cell migration toward the cathode, as previously observed for terminally differentiated chondrocytes. Only late passage cells (P4) were capable of developing cartilage-like tissue in micropellet culture. CONCLUSIONS: Our results show cell priming protocols carried out for four passages selectively differentiate stem cells to behave like chondrocytes, both in their motility response to applied electric field and their production of cartilaginous tissue.

Comparison of nanosecond and femtosecond pulsed laser deposition of silver nanoparticle films.

Nanoparticle (NP) films of silver were prepared using nanosecond (ns) and femtosecond (fs) pulsed laser deposition (PLD) in vacuum. The flux and energy distribution of the ions in the plasma part of the ablation plume were measured using a Langmuir ion probe. The deposition energy efficiencies of ns and fs silver PLD were also compared. For equivalent thickness up to ∼3 nm the NPs made by ns-PLD are well separated and roughly circular, but for higher thicknesses the NPs begin to coalesce. For equivalent thickness up to 7 nm the fs films are comprised of well separated NPs, though the mean NP size and the surface coverage increase with equivalent thickness. The mean Feret diameter for both ns- and fs-PLD films increases with increasing equivalent solid-density thickness. The surface plasmon resonance peak was observed to red shift for both ns- and fs-PLD films as the equivalent solid-density thickness was increased from 1 nm to 7 nm.

Time and dose-dependent effects of chondroitinase ABC on growth of engineered cartilage.

Tissue engineering techniques have been effective in developing cartilage-like tissues in vitro. However, many scaffold-based approaches to cultivating engineered cartilage have been limited by low collagen production, an impediment for attaining native functional load-bearing tensile mechanical properties. Enzymatic digestion of glycosaminoglycans (GAG) with chondroitinase ABC (chABC) temporarily suppresses the construct's GAG content and compressive modulus and increases collagen content. Based on the promising results of these early studies, the aim of this study was to further promote collagen deposition through more frequent chABC treatments. Weekly dosing of chABC at a concentration of 0.15 U/mL resulted in a significant cell death, which impacted the ability of the engineered cartilage to fully recover GAG and compressive mechanical properties. In light of these findings, the influence of lower chABC dosage on engineered tissue (0.004 and 0.015 U/mL) over a longer duration (one week) was investigated. Treatment with 0.004 U/mL reduced cell death, decreased the recovery time needed to achieve native compressive mechanical properties and GAG content, and resulted in a collagen content that was 65 % greater than the control. In conclusion, the results of this study demonstrate that longer chABC treatment (one week) at low concentrations can be used to improve collagen content in developing engineered cartilage more expediently than standard chABC treatments of higher chABC doses administered over brief durations.

Stroke recurrence within the time window recommended for carotid endarterectomy.

OBJECTIVE: In the North Dublin Population Stroke Study, we investigated the risk of recurrent stroke within the 14-day time window recommended for endarterectomy. METHODS: In a population-based prospective cohort study, all ischemic stroke patients were identified over 1 year and categorized into those with (CS-positive) and without (CS-negative) ipsilateral carotid stenosis (CS) (≥50% lumen narrowing). Nonprocedural stroke recurrence was determined at 72 hours and 7 and 14 days. RESULTS: Of 365 ischemic stroke patients with carotid imaging, 51 were excluded due to posterior circulation or nonlateralizing stroke, ipsilateral carotid occlusion, or intracranial stenosis, leaving 314 included for analysis (36 CS-positive and 278 CS-negative). Recurrent stroke occurred in 5.6% (2/36) CS-positive and 0.4% (1/278) CS-negative patients by 72 hours of symptom onset (p =0.003), 5.6% (2/36) CS-positive and 0.7% (2/278) CS-negative patients (p =0.01) by 7 days, and in 8.3% (3/36) CS-positive and 1.8% (5/278) CS-negative patients by 14 days (p =0.02). On multivariable Cox regression analysis, CS was the only independent predictor of recurrence at 72 hours (adjusted hazard ratio [HR] 36.1, 95% confidence interval [CI] 1.6-837.5, p =0.03), and 7 days (HR 9.1, 1.1-79.2, p =0.05), with a trend at 14 days (HR 4.6, 0.9-22.8, p =0.06). CONCLUSIONS: Although only a minority of patients with symptomatic CS had a recurrent stroke within 14 days, early recurrent stroke risk was high, particularly within the first 72 hours. Earlier carotid revascularization or improved acute medical treatment may reduce recurrence in this high-risk group.

Using quality management to balance the economic and humane imperatives in behavioral health care.

The authors describe how quality management can be used to achieve an ethical balance between economic pressures and high-quality patient care.

How do individuals expect to be viewed by members of lower status groups? Content and implications of meta-stereotypes.

Three studies demonstrated that meta-stereotypes held by members of dominant groups about how their group is viewed by a lower status group have important implications for intergroup relations. Study 1 confirmed that White Canadians hold a shared negative meta-stereotype about how they are viewed by Aboriginal Canadians; Studies 2 and 3 extended these results to people's beliefs about an individual out-group member's impressions of them. Feeling stereotyped was associated with negative emotions about intergroup interaction as well as decreases in current self-esteem and self-concept clarity. The perceptions of low- and high-prejudiced persons (LPs and HPs) diverged in a manner consistent with their distinct personal values and group identifications. LPs held a more negative meta-stereotype than did HPs. However, in a one-on-one interaction, HPs sensed that they were stereotyped, whereas LPs felt that they conveyed a counterstereotypical impression.

Rectal endometriosis mimicking solitary rectal ulcer syndrome.

We report a unique case of rectal endometriosis mimicking solitary rectal ulcer syndrome. Several rectal biopsies were performed before the correct diagnosis of rectal endometriosis was made. The lesion had striking histologic features resembling colitis cystica profunda. The presence of two types of glands, i.e., colonic glands with marked depletion of mucin and endometrial glands, were readily apparent on immunohistochemical stain using anticarcinoembryonic antigen showing positive cytoplasmic stain for colonic glands but negative for endometrial glands. However, the distinction between colonic and endometrial glands was very difficult on hematoxylin-and-eosin-stained slides. Endometrial stroma was identified only in the sixth biopsy specimen. Although rare, rectal endometriosis should be considered in the differential diagnosis of solitary rectal ulcer syndrome.

Obturator hernia: diagnosis through medical imaging.

A rare case of obturator hernia is presented in a patient with persistent small bowel obstruction. There was a paucity of specific signs and poor general health which caused a delay in diagnosis. Ultimately delayed films from a barium follow through showed barium-filled bowel in the region of the right obturator foramen: A computed tomography scan then confirmed the diagnosis by demonstrating the barium-filled small bowel herniating through the right obturator foramen. Other imaging modalities such as herniography, barium enemas and ultrasound have also been successfully employed to diagnose obturator hernias.

Good outcome associated with a standardized treatment protocol using selective postoperative radiation in patients with clinical stage I adenocarcinoma of the endometrium.

In 1982, a treatment protocol was instituted for the management of patients with clinical stage I adenocarcinoma of the endometrium. All pertinent historical, operative, and pathologic findings were reviewed by a multidisciplinary committee and 384 patients were prospectively assigned to either high- or low-risk categories. Patients were excluded from the study if they had clinically apparent extrauterine disease, clear cell or serous histologies, or microscopic ovarian metastasis. Patients were considered high-risk if they had one or more of the following factors: grade 3 tumor differentiation, myometrial invasion > 50% of the total wall thickness, pathologic cervical involvement, or adenosquamous histology. Two-hundred twenty-seven (59%) low-risk patients were followed without further treatment after surgery, while pelvic radiation was recommended for 157 (41%) high-risk patients. The 5-year relapse-free survival rates in the low- and high-risk groups were 95 and 81%, respectively. There were no treatment-related deaths. Severe or life threatening chronic radiotherapy complications occurred in 6 (5%) patients. Multivariate Cox analysis identified the following significant prognostic factors: grade, myometrial invasion, cervix involvement, and age. This treatment protocol represents a safe and effective method of managing patients with carcinoma of the endometrium and spares the need for radiation therapy in the low-risk patient.

Role of cardiorespiratory abnormalities, smoking and dive characteristics in the manifestations of neurological decompression illness.

1. Blind analysis of contrast echocardiograms to detect intracardiac shunts, blind analysis of lung function tests for evidence of small airways disease, smoking history and dive characteristics were examined in an attempt to explain neurological symptoms that occurred within 5 min of surfacing from unprovocative dives. 2. Pulmonary abnormalities were significantly more frequent in those divers without intracardiac shunts (50%) than in those with shunts (0%). Smoking was more common in those divers without shunts (55% versus 15%), although this just failed to reach conventional significance levels. Divers without shunts experienced cerebral rather than spinal symptoms after significantly shallower dives with lower tissue nitrogen loads. Depths of dives, tissue nitrogen loads and clinical manifestations in those divers without shunts were similar to the findings in divers who had symptoms after rapid ascents. Despite conservative dive profiles, clinical manifestations in divers with shunts resembled those observed after missed decompression stops. 3. The findings suggest that occult lung disease, and probably smoking, increase the risk of neurological symptoms, even after unprovocative dives, and the similarity of the dive profiles and clinical manifestations to cases with rapid ascents suggest that pulmonary barotrauma and arterial gas embolism are responsible. In divers with intracardiac shunts the different dive profiles and clinical manifestations imply that there is another mechanism, involving different tissue and bubble nitrogen kinetics resulting in venous gas liberation and peripheral amplification in embolized tissues, rather than paradoxical embolism per se.

A fast response membrane-based pH indicator optode.

A cellulose acetate based optode membrane containing 4-dimethylamino-4'-octylazobenzene as an acid-base indicator is described. Other essential components of the membrane for a fast-responding and durable sensor are diethyl phthalate, triethyleneglycol and potassium tetrakis(4-chlorophenyl)borate. Factors affecting the sensor behaviour are discussed and an application in a flow-cell is demonstrated.

Reversal of suppression of lymphokine-activated killer cells by transforming growth factor-beta in ovarian carcinoma ascitic fluid requires interleukin-2 combined with anti-CD3 antibody.

Ascitic fluid from human ovarian carcinoma (AF) has been shown to inhibit IL-2-induced lymphokine-activated killer (LAK) cell generation from peripheral blood mononuclear cells (PBMC) resulting from the presence of biologically active transforming growth factor-beta (TGF-beta). A 50% concentration of AF completely suppressed the LAK response to 100 units IL-2/ml and only partial reversal (less than 50%) could be achieved by increasing the IL-2 concentration to 1000 units/ml. We evaluated the ability of tumor necrosis factor-alpha (TNF-alpha, 1-1000 ng/ml) and anti-CD3 antibody (alpha-CD3, 1-100 ng/ml) to reverse AF-mediated suppression of IL-2-stimulated LAK generation. TNF-alpha alone did not generate significant LAK activity, but in the presence of suboptimal concentrations of IL-2 (10 and 100 units/ml), TNF-alpha significantly boosted the generation of LAK, but was unable to significantly reverse AF-mediated suppression of the IL-2 response (even at 1000 units/ml). In contrast, alpha-CD3 alone generated LAK activity at concentrations as low as 1 ng/ml and markedly enhanced generation of LAK activity when added to suboptimal concentrations of IL-2. alpha-CD3 combined with IL-2 significantly reversed AF suppression at 100 units IL-2/ml and at 1000 units/ml completely reversed suppression by two of three highly suppressive samples of AF. Significant reversal occurred with the third AF sample. It may be possible to overcome TGF-beta-mediated suppression by measures other than by increasing the IL-2 concentration.