Investigation of the protective suitability of a dental fluorinated varnish by means of X Ray fluorescence and Raman spectroscopy

BACKGROUND AND AIM

Evaluating the protective effect in human enamel of a fluorinated varnish after enduring a citric acid erosive challenge.

METHODS

An in vitro model was developed considering the intraoral environment, human saliva and acid erosive procedures. The evaluation of the enamel specimens was undertaken through the direct analysis of enamel by means of Raman spectroscopy and Energy Dispersive X Ray Fluorescence (EDXRF). Ten tooth specimens per group were analysed during three stages: 1- before treatment; 2- After varnish (treatment group) or toothpaste (control) application; 3- After citric acid cycle. Additionally, Particle Induced Gamma Ray emission (PIGE) was used to gauge the fluorine uptake by enamel after the application of the varnish (stage 2). Results were presented as mean and standard deviation with ANOVA and Tukey post hoc performed considering a significance level of 0.05.

RESULTS

A significant (p < 0.05) higher Ca levels were detected in treatment group at stage 2 (37.4 ± 0.4 w/w%) and 3 (37.1 ± 0.1) when compared to the control group. After varnish application in treatment group, depolarization ratios were significant lower (p < 0.05) and anisotropy were significant higher (p < 0.05), however no differences were detected in FWHM.

CONCLUSIONS

The use of a fluorinated dental varnish suggests a protective effect for human enamel against dental erosion demineralization process which was detectable in an in vitro model.

Effect of kernel processing and particle size of whole-plant corn silage with vitreous endosperm on dairy cow performance

Kernel processing and theoretical length of cut (TLOC) of whole-plant corn silage (WPCS) can affect feed intake, digestibility, and performance of dairy cows. The objective of this study was to evaluate for lactating dairy cows the effects of kernel processing and TLOC of WPCS with vitreous endosperm. The treatments were a pull-type forage harvester without kernel processor set for a 6-mm TLOC (PT6) and a self-propelled forage harvester with kernel processor set for a 6-mm TLOC (SP6), 12-mm TLOC (SP12), and 18-mm TLOC (SP18). Processing scores of the WPCS were 32.1% (PT6), 53.9% (SP6), 49.0% (SP12), and 40.1% (SP18). Twenty-four Holstein cows (139 ± 63 d in milk) were blocked and assigned to six 4 × 4 Latin squares with 24-d periods (18 d of adaptation). Diets were formulated to contain 48.5% WPCS, 15.5% citrus pulp, 15.0% dry ground corn, 9.5% soybean meal, 6.8% low rumen degradability soybean meal, 1.8% calcium soap of palm fatty acids (FA), 1.7% mineral and vitamin mix, and 1% urea (dry matter basis). Nutrient composition of the diets (% of dry matter) was 16.5% crude protein, 28.9% neutral detergent fiber, and 25.4% starch. Three orthogonal contrasts were used to compare treatments: effect of kernel processing (PT6 vs. SP6) and effect of TLOC (particle size; SP6 vs. SP12 and SP12 vs. SP18). Cows fed SP6 produced 1.2 kg/d greater milk yield with no changes in dry matter intake, resulting in greater feed efficiency compared with PT6. Cows fed SP6 also produced more milk protein (+36 g/d), lactose (+61 g/d), and total solids (+94 g/d) than cows fed PT6. The mechanism for increased yield of milk and milk components involved greater kernel fragmentation, starch digestibility, and glucose availability for lactose synthesis by the mammary gland. However, cows fed SP6 had lower chewing time and tended to have greater levels of serum amyloid A compared with PT6. Milk yield was similar for SP6 and SP12, but SP12 cows tended to have less serum amyloid A with greater chewing time. Cows fed SP18 had lower total-tract starch digestibility and tended to have lower plasma glucose and produce less milk compared with cows fed SP12. Compared with PT6, feeding SP6 raised linear odd-chain FA concentration in milk. Similarly, a reduction of these same FA occurred for SP12 compared with SP6. Cows fed SP6 had greater proportion of milk C14:1 and C16:1 compared with PT6 and SP12. Lesser trans C18:1 followed by greater C18:0 concentrations were observed for SP12 and PT6 compared with SP6, which is an indication of more complete biohydrogenation in the rumen. Under the conditions of this study, the use of a self-propelled forage harvester with kernel processing set for a 12-mm TLOC is recommended for WPCS from hybrids with vitreous endosperm.

Evaluation of the effect of fluorinated tooth bleaching products using polarized Raman microscopy and particle induced gamma-ray emission

In this in vitro study, the effect of the application of tooth bleaching products in human enamel was evaluated using polarized Raman microscopy, particle induced gamma-ray emission (PIGE) and Vickers Hardness test. Due to their acidic nature, teeth whitening products are associated with changes in enamel mineralization. Consequently, products have appeared in the market that promote the incorporation of fluorine in order to decrease the solubility of the hydroxyapatite in enamel and prevent demineralization. This way, four commercial products with different active principle concentrations: 16% carbamide peroxide (Opalescence PF® and VivaStyle®) or 6% hydrogen peroxide (Opalescence Go PF® and VivaStyle Paint On®) and presence or not of fluorine were compared. The information on the crystalline state of the enamel was provided by the determination of the depolarization ratio of the symmetric stretching band of phosphate (at 959 cm^-1). Furthermore, the content and uptake of F was evaluated using PIGE in the two fluorinated products as well as in one negative control group. In order to evaluate the microhardness of enamel by means of Vickers test, another group of polished samples was prepared (using Opalescence PF®) and evaluated. Conversely to what could be expected, the obtained results determined a statistically significant decrease of depolarization ratio, leading to an increase of mineralization after the application of the bleaching products, except for VivaStyle®. For this group, no significant variation was obtained before-after treatment, most likely due to the acidity of the product (pH = 5.8). Additionally, an increase of concentration of F in the dental tissues was determined for the fluorinated products. On the other hand, enamel polishing, required for the application of the Vickers test, led to increased susceptibility to erosion, resulting in decreased hardness and an increased enamel depolarization ratio.

The effect of length of storage and sodium benzoate on the nutritive value of reconstituted sorghum grain silages for dairy cows

Twenty Holstein cows at 168 ± 87 d in milk (mean ± SD) were assigned to a 4 × 4 Latin square design with a 2 × 2 factorial arrangement to evaluate the effects of 2 storage lengths (30 or 90 d) and the presence of sodium benzoate (control or 0.2% as fed) on the nutritive value of reconstituted sorghum grain silages (RSGS). For each treatment, dry ground sorghum grain was rehydrated to 35% moisture and ensiled in 200-L plastic drums. The treatments were RSGS stored for 30 d without sodium benzoate (30 CON), RSGS stored for 30 d with sodium benzoate (30 BEN), RSGS stored for 90 d without sodium benzoate (90 CON) and RSGS stored for 90 d with sodium benzoate (90 BEN). Diets contained 16.3% RSGS. Silages stored for 90 d had higher concentrations of 1,2-propanediol, soluble protein, and ammonia nitrogen than did those stored for 30 d. Sodium benzoate reduced ethanol and ethyl-ester formation. Silages stored for 90 d had higher starch (89.3 vs. 86.9%) and protein (57.1 vs. 54.0%) digestibility compared with silages stored for 30 d. The ruminal acetate-to-propionate ratio tended to be lower in RSGS stored for 90 d than in RSGS stored for 30 d (3.75 vs. 3.34). Milk yield increased from 30.0 kg/d in cows fed RSGS stored for 30 d to 31.2 kg/d in cows fed RSGS stored for 90 d, without a change in dry matter intake (23.5 kg/d on average). Hence, feed efficiency and milk N efficiency also had tendencies to increase in cows fed RSGS stored for 90 d. Sodium benzoate did not alter cow performance but slightly increased plasma glucose (65.2 vs. 63.6 mg/dL). In conclusion, increasing the storage period of RSGS from 30 to 90 d improved starch and protein digestibility, milk yield, and feed efficiency.

HIV-1 vertical transmission in Rio Grande, Southern Brazil

The aim of this study was to determine the rate and risk factors of HIV-1 mother-to-child transmission (MTCT), the timing of transmission and the transmitted subtype in a population where subtypes B and C co-circulate. One hundred and forty-four babies born to HIV-1-infected mothers were studied. Subtype and timing of transmission were determined by a nested polymerase chain reaction of the gp41 gene. Seven children were infected (4.9%): four were infected intrautero and one intrapartum. The higher frequency of intrautero transmission was statistically significant ( P = 0.001). Use of antiretrovirals (ARVs) in the three stages of gestation was a protective risk factor for MTCT (PR = 0.42; CI: 0.21–0.83; P = 0.013). A higher HIV viral load at delivery was the only independent risk factor for MTCT. Early and universal access to ARVs during pregnancy are the most important measures to decrease vertical HIV-1 transmission even in areas where HIV clade distribution differs.

The needs of patients with cancer and their caregivers in rural areas

PURPOSE/OBJECTIVES

To describe physical and psychological needs, rank their importance, and identify needs that were not met of patients with cancer and their caregivers living in rural settings.

DESIGN

Exploratory descriptive.

SETTING

Rural Vermont.

SAMPLE

30 patients with cancer and 30 caregivers.

METHODS

Patients completed the self-administered. 104-item Patient Needs Scale; caregivers completed the self-administered, 90-item Caregiver Needs Scale. Respondents were asked to rate the importance of an item on a scale of 1-10 if they considered if a need. If a numbered item was scored, respondents identified whether the need was met.

FINDINGS

The patient group identified 49% of scale items as needs; the caregiver group identified 41% of scale items as needs. Greater than 50% of the patient and caregiver respondents identified needs in areas of personal care. Involvement with health care, and interpersonal Interaction as very important. The patient group reported that 5% of identified needs were unmet, whereas the caregiver group reported that 14% of identified needs were unmet.

CONCLUSIONS

In rural settings, caregiver needs, while fewer in number, are not met three times more frequently than patient needs.

IMPLICATIONS FOR NURSING PRACTICE

The needs identified by more than 50% of both groups should be included in assessment and care plans. The variability of patient and caregiver needs reinforces the importance of individual assessment and planning rather than making assumptions about needs. Future research may include identifying questions to elicit current needs and determining how often these questions should be asked to meet changing needs.

Shared psychotic disorder: a critical review of the literature

OBJECTIVE

To search the literature to reassess the concept of shared psychotic disorder (SPD) using modern nosology and current biopsychosocial formulation.

METHOD

Analyzing published case reports from 1942 through to 1993 that meet DSM-IV criteria for SPD according to patient age, sex, nature and duration of the relationship with the "primary", length of exposure to primary's psychosis, family psychiatric history, comorbidity, social isolation of the dyad, presence of hallucinations, delusional type, and the diagnosis of the primary.

RESULTS

Findings revealed: 1. males and females were affected with equal frequency; 2. there was equal prevalence in younger and older patients; 3. the majority of shared psychoses (90.2%) were equally distributed among married couples, siblings, and parent-child dyads; 4. comorbid dementia, depression, and mental retardation were common; 5. hallucinations were common; 6. the majority of dyads (67.3%) were socially isolated.

CONCLUSIONS

SPD probably occurs in premorbidly disposed individuals in the context of social isolation which is shared with a psychotic person.

Mutagenicity monitoring in humans by autoradiographic assay for mutant T lymphocytes

Somatic cell mutation which occurs in vivo in humans can be determined by measurement of the frequency of the 6-thioguanine-resistant (TGr) T lymphocytes in samples of peripheral blood. This frequency can be determined by either a short-term autoradiographic methodology or a longer cell-cloning methodology. The advantage of the former is the relative simplicity of the assay, while the latter allows recovery of mutant clones for further characterization. This report presents results of a longitudinal study of cancer chemotherapy nurses and other health care personnel by use of the autoradiography assay. The use of this assay in human mutagenicity monitoring and the analysis of the TGr cell frequencies are discussed in terms of age effects and validation of 'elevated' frequencies by use of the clonal assay. This report then presents evidence that both assays yield similar TGr cell frequencies in two groups of 'normal adults'. The mean variant frequency (+/- S.D.) for 82 autoradiographic assays was 8.7 (+/- 6.1) X 10(-6), while the mean mutant frequency (+/- S.D.) for 115 clonal assays was 6.5 (+/- 4.8) X 10(-6). In addition, concurrent autoradiographic and clonal assays on 33 individuals yielded mean values (+/- S.D.) of 8.4 (+/- 8.5) X 10(-6) and 10.5 (+/- 6.3) X 10(-6), respectively.