Influence of exposure mode on vinyl chloride action

Rats were subjected to 4 h continuous or intermittent exposure to vinyl chloride (VC) at different time-weighted average concentrations (15, 50, 150, 500 and 15,000 mg/m³). Hepatic non-protein sulfhydryl content (NPSH) and excretion of thiodiglycolic acid (TdGA) in urine were determined. VC at concentrations from 50 mg/m³ to 15,000 mg/m³ caused a dose-dependent depression of NPSH, but no difference in the magnitude of this depression induced by continuous or intermittent exposure at the same average concentration of VC was noted. At average concentrations of 50 mg/m³ and 150 mg/m³, the urinary excretion of TdGA under continuous exposure did not differ from that under intermittent exposure, whereas at VC concentrations of 500 mg/m³ and 15,000 mg/m³ it was higher following continuous exposure.     

Directions of Changes in the Health Values of Dairy Products in the Opinion of Consumers

The aim of our research was to assess whether and to what extent the perceived change in the content of selected ingredients in dairy products is important for Polish consumers in accepting the enhancement of the health benefits of dairy products, including yogurt. The data were collected using a CAPI (Computer Assisted Personal Interview) survey on a sample of 983 consumers. The logistic regression model was used to predict the behavior of consumers associated with their willingness to accept the health aspects of improving dairy products. The results indicated that changes in the level of selected ingredients enhanced the willingness to accept increasing the health value of the product. The socio-demographic characteristics of the participants were not associated with the degree of their willingness to accept the improvement of the perceived health attributes. Practitioners in the dairy industry and policy makers can benefit from these results. When designing food products, it is worth focusing on increasing the nutritional value and enhancing the health value of food that is perceived by consumers as generally possessing positive health benefits, rather than on food that is perceived by them as possessing negative qualities.     

Salivary Content Might be Associated With Skeletal Status in Postmenopausal Women: SilesiaOsteoActive Study Results

Aim: The aim of the study was to investigate whether salivary mineral content may be associated with bone status in women after menopause. Material and methods: The study group consisted of 125 postmenopausal women aged 64.3 ± 6.9 yr, derived from the epidemiological SilesiaOsteoActive Study. All participants underwent hip and spine bone densitometry using dual energy X-ray absorptiometry, dental examination, and saliva content analysis. Data for salivary pH, copper, calcium, phosphorus, and zinc concentrations were evaluated. Results: Mean femoral neck bone mineral density (BMD) was 0.739 ± 0.118 g/cm², total hip BMD 0.891 ± 0.14 g/cm², and spine BMD 0.868 ± 0.14 g/cm². Salivary pH was significantly lower in women with spinal osteoporosis defined as T-score below ?2.5, compared to individuals with normal BMD (pH: 6.65 ± 0.67 vs 6.96 ± 0.58, p < 0.05). There was a significant though weak inverse correlation between Ca concentration in saliva and femoral neck BMD (r = ?0.23, p < 0.05). Conclusions: High salivary calcium content and low salivary pH may be indicative of low hip and decreased spine BMD, respectively. These associations may reflect demineralization process (calcium redistribution) influencing bone, and a negative effect of acidity on mineral tissues, although causal pathway remains not clear.     

Low doses of oxytocin facilitate social recognition in rats

Social recognition of juveniles by adult male residents has been shown to be modulated by neurohypophyseal hormones. The decrease of social investigation behavior during a second encounter with the same juvenile serves as index for social recognition. In the present study it was found that low doses (0.09–6.0 ng · kg^–1) of oxytocin (OXT) given subcutaneously dose dependently facilitated social recognition. The effect of OXT appeared specific, since no change in social investigation was found when a novel juvenile was tested during the second encounter. No disturbances of social recognition by the low doses of OXT could be detected, in contrast to higher doses of this hormone. Other neurohypophyseal hormones, vasopressin and vasotocin, did not facilitate social recognition when tested in the same range of low doses.     

Control of the RIA method as viewed from the standpoint of the investigation on the kinetics of the insulin-125I-antibody reaction

In this paper attempts were made towards the optimalization and the control of some parameters of the RIA reaction.Basing on the law mass action, as well as on the Scatchard's and Sips's equations, the equilibrium constants for the reversible reaction: insulin-¹²⁵I-antibody for different incubation temperatures were calculated. Moreover a characteristic of the antiinsulin antibody by means of the heterogeneity coefficient was done, as well as the values of the thermodynamic function increments were calculated, which made possible to point out explicitly the optimal shape of the standard curve.     

High prognostic value of p16INK4 alterations in gastrointestinal stromal tumors.

PURPOSE: Gastrointestinal stromal tumors (GISTs) represent a distinctive (but histologically heterogeneous) group of neoplasms, the malignant potential of which is often uncertain. To determine the prognostic relevance of p16INK4 alterations in GISTs, we investigated a larger group of GISTs and correlated the genetic findings with clinicopathological factors and patient survival. MATERIAL AND METHODS: We evaluated the methylation status of the promotor by methylation-specific polymerase chain reaction (PCR), the presence of mutations by PCR-SSCP-sequencing, the loss of heterozygosity at the p16INK4 locus (using the c5.1 marker), and the immunohistochemical expression of p16INK4 protein in 43 GISTs in 39 patients. RESULTS: p16INK4 alterations were found in 25 of 43 GISTs (58.1%), with benign, borderline, or malignant GISTs showing no differences in the type and frequency of alteration. p16INK4 alterations were correlated with a loss of p16INK4 protein expression (P <.01). Patients who had tumors with p16INK4 alterations had a poorer prognosis than patients with tumors without such alterations (P =.02). There was a high predictive value for p16INK4 alterations only in the group of benign and borderline GISTs (P <.01) with regard to clinical outcome. Univariate Cox's proportional hazard regression analysis revealed a strong correlation between p16INK4 alterations, tumor size, mitotic index, and overall survival (P <.02), whereas multivariate Cox's analysis confirmed only p16INK4 alterations as an independent prognostic factor. CONCLUSION: We believe that the evaluation of p16INK4 alteration status is a helpful prognosticator, particularly in the benign and borderline groups of GISTs.     

Inhibition of bone repair in a rat model for chronic and excessive alcohol consumption.

Alcohol abuse is associated with increases in both the incidence of fractures and complications in fracture healing. The purpose of this study was to determine the dose-dependent effects of ethanol on bone repair in a rat model. Three-month-old male Wistar rats were continuously fed liquid diets containing ethanol as either 36% or 26% of total calories or control diets for 6 weeks. Then, a bone repair model was created in all rats. Bone healing and liver metabolism were evaluated 7 weeks after bone injury. For each dose, there were three ethanol-feeding groups receiving (1) ethanol for 13 weeks, (2) control diet for 13 weeks (pair-fed), and (3) ethanol before bone injury and control diet (pair-fed) after injury. Another group was fed ethanol (36%) before injury and given control diet ad libitum after injury. There were also two nutritional controls consuming control diet and standard rat chow ad libitum for 13 weeks. Abnormal liver metabolism was evident at the higher ethanol dose - increases in cytochrome P4502E1 specific activity (5-fold; P < .01), triglyceride content (4-fold; P < .02), and liver weight (25%; P = .05) - compared with pair-fed controls. The higher dose of ethanol resulted in deficient bone repair when compared with rats receiving ethanol-free control diet by pair-feeding: 26% less (P = .02) rigidity of the repaired bone, 41% less (P = .02) intrinsic stiffness, 24% less intrinsic strength (P = .05), and 14% less (P = .001) ash density of the repair tissue. The reduced food consumption of ethanol-fed rats compared with that in the nutritional controls did not contribute to this deficiency. Furthermore, removal of ethanol (as 36% of calories) from the diet after bone injury completely restored normal bone healing and nearly normalized the liver metabolism. The lower ethanol dose (26% of calories) had a minimal effect on liver metabolism and bone repair. We conclude that ethanol (as 36% of calories) in the rat diet, especially during the postinjury period, was solely responsible for the observed inhibition of bone repair.     

Usefulness of high doses of glucocorticoids and hyperbaric oxygen therapy in sudden sensorineural hearing loss treatment.

OBJECTIVE: We investigated the effect of pharmacologic (steroids, vasodilators, vitamins, and Betaserc) and hyperbaric oxygen therapy on patients with sudden sensorineural hearing loss. METHODS: The pharmacologic arm of the study consisted of 52 patients with defined sudden sensorineural hearing loss treated simultaneously in the ENT Department and National Center for Hyperbaric Medicine of the Medical University of Gdansk, Poland, from 1997 to 2000 (Group A). The hyperbaric oxygen therapy consisted of exposure to 100% oxygen at a pressure of 250 kPa for a total of 60 minutes in a multiplace hyperbaric chamber. The control group included 81 patients with defined sudden sensorineural hearing loss treated in the ENT Department, Medical University of Gdansk, from 1980 to 1996 (Group B). Both groups were comparable regarding the age of the patients, season of hearing loss occurrence, tinnitus and vestibular symptom frequency, delay before therapy, and average threshold loss before the start of treatment. The treatment results (hearing gain) were estimated using pure-tone audiometry. We retrospectively analyzed the audiograms of all patients. RESULTS: Patients from Group A (blood flow-promoting drugs, glucocorticoids in high doses, betahistine, and hyperbaric oxygen therapy) showed significantly better recovery of hearing levels compared with those from Group B (blood flow-promoting drugs and glucocorticoids in low doses) at seven frequencies (500, 1,000, 2,000, 3,000, 4,000, 6,000, and 8,000 Hz) (p < 0.05) and four groups of frequencies (pure-tone average, high-tone average, pure middle-tone average, and overall average) (p < 0.05). Percentage hearing gain in all investigated frequencies was also better in Group A versus Group B, and the differences were statistically significant (p < 0.05). CONCLUSION: We conclude that hyperbaric oxygen therapy with high doses of glucocorticoids improves the results of conventional sudden sensorineural hearing loss treatment and should be recommended. In addition, the best results are achieved if the treatment is started as early as possible.