Neurotoxicity induced by exposure to toluene. An electrophysiologic study

The object of the present study was to evaluate, with the aid of electrophysiologic techniques, the alterations induced in the auditory nervous system by exposure to toluene in a group of rotogravure workers. From 300 workers who were apparently in good health but were professionally exposed to toluene, we selected a sample of 40 workers of normal hearing ability. They were examined with an adaptation test studied by the brainstem auditory evoked potential technique with 11 and 90 stimulus repetitions a second. The results were compared with those in a group of workers of the same age but not professionally exposed to solvents. Our study demonstrates that exposure to toluene is able to induce a statistically significant alteration in the electric responses with both 11 and 90 stimuli repetitions. This alteration can be explained as a toluene exposure-induced modification, of physiologic stimulus conduction mechanisms, even in the absence of any clinical sign of neuropathy. Furthermore, such a modification could be observed in the electric responses of the entire auditory system, from peripheral receptors to brainstem nuclei.     

Natural Convection along a Vertical Thin Cylinder with Uniform and Constant Wall Heat Flux

A theoretical investigation is carried out to study natural convection around a vertical thin cylinder, or a needle, heated at uniform and constant wall heat flux in order to compare the analytical solutions of the present work with previous experimental results. The local non-similarity solution with the first level of truncation, proposed by Minkowycz and Sparrow, is used. The temperature and velocity distributions are calculated for fluids with several Prandtl numbers. The analytical solutions of this work are compared to experimental results carried out with needles of diameters ranging from 0.6 to 1.5 mm and fluids with Prandtl numbers in the range Pr = 0.7–730. The agreement is reasonable good.     

The genetic basis for smoking behavior: a systematic review and meta-analysis.

Considerable evidence indicates that smoking behavior is under a degree of genetic influence. We conducted a systematic review of candidate gene studies of smoking behavior and, where sufficient studies existed, combined reported data using meta-analytic techniques. A total of 41 studies were identified by the search strategy, of which 28 contributed to the meta-analysis. The meta-analysis included data on the DRD2, DAT, 5HTT, and CYP2A6 genes and smoking behavior. Categorical data were extracted on smoking status (never-smoker, ex-smoker, current smoker). Continuous data were extracted on number of cigarettes smoked per day. Evidence indicated effects of the DRD2 Taq1A polymorphism and smoking initiation, the 5HTT LPR and CYP2A6 reduced-activity polymorphisms and smoking cessation, and the DRD2 Taq1A and CYP2A6 reduced-activity polymorphisms and cigarette consumption. The evidence for an effect of specific genes was modest, however, and evidence indicated substantial between-study heterogeneity in most cases, with the exception of the effects of the 5HTT and CYP2A6 genes on smoking cessation. When a random-effects model was applied to analyses in which evidence indicated significant heterogeneity, the effects were in all cases no longer statistically significant. The evidence for a contribution of specific genes to smoking behavior remains modest. Implications for the design of future studies are discussed, such as the need for the development of more specific phenotypes to increase the genetic signal in candidate gene studies.     

Cloning and sequencing of a 16S/23S ribosomal spacer from Haemophilus parainfluenzae reveals an invariant, mosaic-like organisation of sequence blocks

The aim of this study was to evaluate the clinical efficacy, mechanical stability, and safety of the Simon nitinol inferior vena cava filter (SNF). The SNF was inserted in 114 consecutive patients at two institutions for prophylaxis of pulmonary embolism (PE). Clinical follow-up data were obtained retrospectively on all patients, and 38 patients underwent a dedicated radiologic follow-up protocol consisting of abdominal radiography, Doppler sonography, and CT. There was no immediate complication following filter insertion. Fifty patients died, on average, 5.6 (1-23) months after filter insertion, and 64 patients were alive, on average, 27 (3-62) months after filter insertion. Recurrent pulmonary embolism was documented in 5 patients (4.4 %) but originated distal to the filter in 1 patient. Deep venous thrombosis (DVT) was documented in 5.3 %, thrombosis at the access site in 3.5 %, and thrombosis of the inferior vena cava in 3.5 %. The rate of thromboembolic complications was similar in patients who did receive long-term anticoagulation and in those who did not. Radiologic follow-up showed no filter migration after, on average, 32 (5-62) months. A CT examination showed that struts of the SNF had penetrated the vena cava in 95 %, and were in contact with adjacent organs in 76 %; however, there were no clinical symptoms attributable to the filter. Filters were in an eccentric position in 63 % and partial filter disruption was found in 16 %; however, this did not affect filter function. The rate of recurrent pulmonary embolism after insertion of the SNF is 2.4 % per patient per year. Regardless of long-term anticoagulation, the rate of caval thrombosis is acceptably low. Except for occasional access-site thrombosis, no other filter-related morbidity was observed.     

Systemic sclerosis after a long-term follow-up

The authors suggest some remarks on the aetiopathogenesis of systemic sclerosis through a critical review of a group of 51 patients affected by this disease for many years. In this paper the authors report their previous studies regarding the correlation of immunological response, both cell-mediated and humoral, hemocoagulative aspects and haemorheological changes. From the results of immunological studies, the authors report a long-term treatment with an immunomodulating drug: thymopentin. Moreover they report a recent work about the connection among stressor event, production of endothelin-1 (ET-1) and serum levels of some stress hormones such as possible pathogenetic factors of Raynaud's phenomenon and of scleroderma. This work ends with a proposal of a pathogenetic scheme that, even if it doesn't exclude an infective pathogenesis, considers stress as a factor able to switch on a series of psycho-neuro-immunoendocrinological reactions that can support, through the activation of lymphocytes, fibroblastic proliferation and finally fibrosis.     

Evaluation of lung inflammation induced by intratracheal administration of LPS in mice: comparison between MRI and histology

Purpose  

To study the in vivo effect of intratracheal administration of lipopolysaccharide (LPS) in mice by magnetic resonance imaging (MRI) and to investigate the correlation with ex vivo histological evaluation of lung inflammation and oedema.     

Personality and smoking status: a meta-analysis.

We used meta-analytic techniques in an attempt to clarify the strength and direction of the association between smoking status and personality, which narrative reviews have indicated remains a largely inconsistent literature. Included were cross-sectional studies that reported personality data for healthy, adult smokers and nonsmokers using measures of personality traits derived from Eysenck's tripartite taxonomy of human personality. Of the 25 studies that contributed to the meta-analysis, 22 reported data on smoking status and extraversion and 22 reported data on smoking status and neuroticism. Meta-analysis using a fixed-effects framework indicated a significant difference between smokers and nonsmokers on both extraversion (p<.001) and neuroticism (p<.001) traits, which remained significant when a random-effects framework was used to accommodate significant between-study heterogeneity. These data from cross-sectional observational studies published between 1972 and 2001 indicate that both increased extraversion and increased neuroticism are associated with an increased likelihood of being a smoker rather than a nonsmoker, although in both cases the effect sizes indicated by the meta-analysis were small. We found no evidence that the strength of these associations varied with year of publication.     

Differential Modulation of Apoptotic Processes by Proanthocyanidins as a Dietary Strategy for Delaying Chronic Pathologies

Apoptosis is a biological process necessary for maintaining cellular homeostasis. Several diseases can result if it is deregulated. For example, inhibition of apoptotic signaling pathways is linked to the survival of pathological cells, which contributes to cancer, whereas excessive apoptosis is linked to neurodegenerative diseases, partially via oxidative stress. The activation or restoration of apoptosis via extrinsic or intrinsic pathways combined with cell signaling pathways triggered by reactive oxygen specises (ROS) formation is considered a key strategy by which bioactive foods can exert their health effects. Proanthocyanidins, a class of flavonoids naturally found in fruits, vegetables, and beverages, have attracted a great deal of attention not only because they are strong antioxidants but also because they appear to exert a different modulation of apoptosis, stimulating apoptosis in damaged cells, thus preventing cancer or reducing apoptosis in healthy cells, and as a result, preserving the integrity of normal cells and protecting against neurodegenerative diseases. Therefore, proanthocyanidins could provide a defense against apoptosis induced by oxidative stress or directly inhibit apoptosis, and they could also provide a promising treatment for a variety of diseases. Emerging data suggest that proanthocyanidins, especially those that humans can be persuaded to consume, may be used to prevent and manage cancer and mental disorders.     

Short communication: Fourier-transform mid-infrared spectroscopy to predict coagulation and acidity traits of sheep bulk milk

Sheep milk is mainly transformed into cheese; thus, the dairy industry seeks more rapid and cost-effective methods of analysis to determine milk coagulation and acidity traits. This study aimed to assess the feasibility of Fourier-transform mid-infrared spectroscopy to determine milk coagulation and acidity traits of sheep bulk milk and to classify milk samples according to their renneting capacity. A total of 465 bulk milk samples collected in 140 single-breed flocks of Comisana (84 samples, 24 flocks) and Sarda (381 samples, 116 flocks) breeds located in Central Italy were analyzed for coagulation properties (rennet coagulation time, curd firming time, and curd firmness) and acidity traits (pH and titratable acidity) using standard laboratory procedures. Fourier-transform mid-infrared spectroscopy prediction models for these traits were built using partial least squares regression analysis and were externally validated by randomly dividing the full data set into a calibration set (75%) and a validation set (25%). The discriminant capacity of the rennet coagulation time prediction model was determined using partial least squares discriminant analysis. Prediction models were more accurate for acidity traits than for milk coagulation properties, and the ratio of prediction to deviation ranged from 1.01 (curd firmness) to 2.14 (pH). Moreover, the discriminant analysis led to an overall accuracy of 74 and 66% for the calibration and validation sets, respectively, with greater sensitivity for samples that coagulated between 10 and 20 min and greater specificity to detect early-coagulating (<10 min) and late-coagulating (20–30 min) samples. Results suggest that Fourier-transform mid-infrared spectroscopy has the potential to help the dairy sheep industry identify milk with better coagulation ability for cheese production and thus improve milk transformation efficiency. However, further research is needed before this information can be exploited at the industry level.