The occurrence and seasonal variation of aflatoxin B1 and zearalenone concentrations in poultry feeds

The present study aimed to investigate the contamination of poultry feed with aflatoxin B1 and zearalenone at laying hen farms in Tehran suburbs. The poultry feed was selected from five laying hen farms. A total of 60 poultry feed samples were collected from each farm during four consecutive seasons, from spring to winter of 2021. High-performance liquid chromatography was used to determine the amount of aflatoxin B1 and zearalenone. The mean aflatoxin B1 and zearalenone concentrations in various seasons showed significant differences (p<0.01). The highest reported aflatoxin concentration was in winter, with a mean concentration of 1366.53±77.85 ng/kg. The lowest concentrations were reported in autumn and summer, indicating a significant difference (p<0.01). The highest concentration of zearalenone was reported in summer, with a mean concentration of 150.72±10.35 μg/kg. The lowest concentration was reported in winter, with a mean concentration of 22.87±10.35 μg/kg, indicating a statistically significant difference (p<0.01). Overall, the concentrations of aflatoxin B1 and zearalenone toxins significantly differed in various poultry farms. The poultry farm D had the highest aflatoxin contamination with a mean concentration of 648.08±59.89 ng/kg. Poultry farms A, B, and C had the highest zearalenone concentrations with mean concentrations of 125.17±20.61, 96.04±20.61, and 99.49±20.61 μg/kg, respectively. Autumn was the only season showing significant differences regarding zearalenone toxin concentration in poultry farms.

Determinants of Subjective Loneliness and Quality of Life among Community-Dwelling Older Adults in Gorgan, Iran

The purpose of this study was to identify the determinants of, and relationship between, subjective loneliness, general health and quality of life (QoL) among lonely community-dwelling older adults. A cross-sectional study was carried out among a sample of lonely (i.e. live alone without any assistance) older adults living in Gorgan city, Iran. The older adults were invited through a census sampling technique to complete six questionnaires, namely a 20-item UCLA loneliness scale, a six-item Lubben Social Network Scale, a 12-item Multidimensional Scale of Perceived Social Support, a 17-item Self-care Ability Scale for the Elderly (SASE), a General Health Questionnaire-12, and a Control, Autonomy, Self-Realization and Pleasure (CASP-19) questionnaire. Hierarchical multiple linear regressions were done with subjective loneliness and QoL as outcome variables. In total, 213 (91% females) lonely older adults (mean age: 68.2 ± 6.2) participated. Hierarchical multiple linear regressions yield socio-demographic characteristics (p < 0.001), predictor group 1 (p < 0.001), predictor group 2 (p < 0.001) explained 12.5, 13.5 and 46.6% of the observed variance in loneliness, respectively. Moreover, socio-demographic characteristics (p < 0.001), predictor group 1 (p < 0.001), predictor group 2 (p < 0.001) and feeling of loneliness (p < 0.001) accounted for 16.9, 21.1, 48.6 and 55.3% of the observed variance in quality of life, respectively. Both subjective loneliness and QoL were moderate in our sample. We suggest the presence of a probable causal inference between subjective loneliness, general health, and QoL; implying the need of population strategies for correcting subjective loneliness for its own sake as well as to help have an improved general health and QoL among older adults. Beside several non-modifiable factors (such as age, ethnic groups), we suggest that corrective measures should be based on social support and networking, self-care behavior, leisure activities, adapted for age, literacy and racial specifications. Given its population health relevance, there should be increased research and intervention on loneliness among older adults.

Evaluation of the epithelial cells of lower lip mucosa after debonding of fixed orthodontic appliances

BACKGROUND

Orthodontic appliances (ligatures, braces, wires, etc.), are one of the main sources of trauma in the oral cavity. Friction between brackets and mucosa is a kind of chronic trauma that may cause buccal mucosal proliferation and ulceration and is one of the most common complaints of patients during orthodontic treatment. The aim of this study was to evaluate the changes of the lower lip epithelial cells after the removal of orthodontic fixed appliances.

METHODS

Cells of lower lip oral mucosa of 31 orthodontic patients were collected by exfoliative cytology in three times: immediately (T0), 30(T1) and 60 (T2) days after debonding. Nuclear (NA) and cytoplasmic (CA) areas, NA/CA ratio, cell morphology and cellularity of smears were evaluated using cytomorphometric and cytomorphologic methods. Friedman test followed by the Wilcoxon test was used to compare the NA, CA and NA/CA values in three different times. Cell morphology and cellularity were analyzed by the Chi-square test. All statistical tests were performed with SPSS version 20.

RESULTS

The NA and CA values increased significantly (P<0.001) after the removal of friction and irritation of orthodontic appliances in T1 and T2 and reached their highest level in T2. The NA/CA values did not change significantly (P=0.25). Class I smears, according to Papanicolaou classification, were observed in T0, T1, and T2. Superficial epithelial cells were predominant cell types in the lower incisor region in all times without statistically significant difference in three intervals.

CONCLUSIONS

Orthodontic appliances increase keratinization of lip mucosa which is considered an adaptive reaction to the mechanical stimulus, but after removing of the appliances cellular activity rapidly increases. Keratinization is the main change observed at the end of orthodontic treatment.

Patient-centered evaluation of alignment changes during the first stage of orthodontic treatment: A longitudinal observational study

Background. The aim of this longitudinal observational study was to evaluate patients’ perceptions of alignment changes during the first stage of fixed orthodontic treatment. Methods. Ninety-three non-extraction patients (mean age: 17.6 years) who were scheduled to undergo fixed-appliance treatment in the first author's private office were included. Patients assessed the alignment of their teeth subjectively using visual analogue scale at the bonding session and four, eight and 12 weeks later. The amount of Little's irregularity index at each session was calculated on stone casts. Freidman test was used to compare the "alignment changes" between different intervals. Correlation coefficients were calculated using Spearman test between Little’s irregularity indices and alignment scores reported by the patients in each session. Results. No patients reported regression in alignment changes during three-month course of treatment. The final changes (from bonding session to the 12th-week visit) were smaller than the sum of the three intervals, which indicated that patients became more perceptive as the treatment progressed. Comparison of two scores reported for each session (in the same session and in the next session) revealed that patients could not recall their previous situation well. Patients do not perceive alignment changes in the same way as clinicians. Furthermore, patients who were 16 or older perceived smaller alignment changes during the first four-week period and smaller final alignment changes. Conclusion. To obtain better patient compliance and improve their motivation throughout orthodontic treatment, patientspecific measures should be undertaken, including reminding them about their initial conditions and highlighting the changes as the treatment progresses.

Seroprevalence and Risk Factors of Neospora caninum and Toxoplasma gondii in Small Ruminants in Southwest of Iran

Toxoplasma gondii and Neospora caninum are Apicomplexan intracellular protozoa with global distribution. Small ruminants play an important role as intermediate hosts for N. caninum and T. gondii, parasites of great public health concern. The main goal of the current survey was to evaluate N. caninum and T. gondii infection rate in sheep and goats of Khuzestan Province, southwest of Iran, using enzyme-linked immunosorbent assay (ELISA). In this cross-sectional study during February-April 2016, whole blood samples were taken randomly from 735 animals from 37 herds. The animals were reared under the traditional husbandry system in different parts of the province. Among 550 sheep and 185 goats, 37 (6.8%) sheep and 20 (10.8%) goats were seropositive for N. caninum and 59 (10.8%) sheep and 37 (20%) goats were seropositive for T. gondii. The incidence rates of mixed infection with N. caninum and T. gondii were 3.2% and 5.4% in sheep and goats, respectively. Seroprevalence rate of N. caninum was significantly higher in goats at T. gondii and abortion (18.2%). Also, a significant correlation was detected between seroprevalence of N. caninum and T. gondii and mixed infection in goats with a history of abortion. This is the first report of IgG antibody production against N. caninumand T. gondii co-infection in small ruminants in Iran. Our findings indicated that neosporosis and toxoplasmosis may be responsible for abortion in small ruminants in this region. Therefore, further investigations are needed to improve sanitary strategies in animals&amp;rsquo; husbandry and launching control programs.

Comparison of Stability of the Results of Orthodontic Treatment and Gingival Health between Hawley and Vacuum-formed Retainers

Aim: Retention is one of the stages of orthodontic treatment, which is an attempt to retain teeth in their corrected positions after active treatment with the use of fixed orthodontic appliances. The aim of the present study was to compare the stability of the results of orthodontic treatment and the gingival health between Hawley retainer (HR) and vacuum-formed retainer (VFR) with two different thicknesses. Materials and methods: In this randomized clinical trial, 66 patients undergoing comprehensive orthodontic treatment in a private office were evaluated after completion of treatment. The subjects were randomly assigned to three groups. At the end of orthodontic treatment, the subjects in all the groups received a fixed bonded retainer in the mandible; in the maxilla, group I received an HR, group II received a VFR with a thickness of 1.5 mm, and group III received a VFR with a thickness of 1 mm. The American Board of Orthodontics objective grading system (ABO-OGS) index was used at the end of treatment (before the delivery of the retainers) and 6 months after the use of retainers to evaluate the stability of the results of orthodontic treatment. Gingival index (GI) was used at the two above-mentioned intervals to evaluate gingival health. The ABO-OGS measurements were carried out on dental casts by a clinician who was blinded to the types of retainers the patients wore. Data were analyzed with Statistical Package for the Social Sciences (SPSS) version 20, using proper statistical analyses. Results: Six months after the delivery of retainers, ABO-OGS and GI scores with the 1.5 mm VFR were higher than those in the two other groups, with no significant differences between the three groups. There were no significant differences between the ABO-OGS scores before the delivery of retainers and 6 months after the use of retainers in any of the study groups. In the HR and 1.5 mm VFR groups, there were significant differences in GI scores between the period before the delivery of the retainers and 6 months after their delivery; however, in the 1 mm VFR group, no significant differences were observed in GI scores between the two time intervals. Conclusion: Hawley retainer and 1 mm thick and 1.5 mm thick VFRs were equally effective in preserving and stabilizing the results of orthodontic treatment during the 6-month interval after the completion of orthodontic treatment. In addition, there were no significant differences between the three retainers in relation to gingival health. Clinical significance: The VFR might be a good alternative for HR due to its better esthetic appearance and greater popularity with orthodontic patients. Keywords: American Board of Orthodontics model grading system, American Board of Orthodontics objective frading system, Gingival index, Hawley retainers, Vacuum-formed retainers.

Compressive Strength of Mineral Trioxide Aggregate with and without Disodium Hydrogen Phosphate at Different Mixing Ratios

Introduction

Mineral Trioxide Aggregate (MTA) is a substance with favorable physical-mechanical properties. Disodium hydrogen phosphate (DHP) is sometimes added to MTA to reduce its setting time. Therefore, this study was conducted to evaluate the effect of various ratios of liquid to powder of white MTA (WMTA) and addition of DHP on its compressive strength.

Methods and Materials

One hundred and twenty samples were prepared with a two-piece stainless steel mold with a height of 6 mm and a diameter of 4 mm in order to evaluate the compressive strength where WMTA was used in 60 samples and DHP in white MTA composition (DHPWMTA) was used in other 60 samples. The compressive strength of WMTA and DHPWMTA was measured in various ratios of liquid to powder including 50, 60 and 70% and at 24 h and 21 days (n=10). Univariate Analysis of Variance test with SPSS 16 software were used to determine the difference between groups. The level of significance was set at 0.05.

Results

The maximum and minimum compressive strength of WMTA groups were 63.25±1.96 (50% ratio and 21 days) and 37.79±1.28 (70% ratio and 24 h), respectively. The maximum and minimum compressive strength of DHPWMTA groups were 63.96±1.40 (60% ratio and 21 days) and 37.37±1.62 (70% ratio and 24 h), respectively. The effect of each of factors (type of material, powder to liquid ratio and time) alone were significant on the compressive strength (P<0.05). However, the interactive effect of three factors (type of material, powder to liquid ratio and time) were not statistically significant on compressive strength (P>0.05).

Conclusion

Adding 2.5 wt% of DHP to white MTA increased samples compressive strength. Compressive strength in liquid to powder ratios of 50 and 60% compare to 70% and at 21 days compared to 24 h was high.

Evaluation of Interdental Spaces of the Mandibular Posterior Area for Orthodontic Mini-Implants with Cone-Beam Computed Tomography

INTRODUCTION

The use of mini-implants has increased in recent years because of their role in absolute anchorage, but the placement sites may affect the success or failure of the procedure, so it is very important to determine the appropriate and safe location for orthodontic mini-implants. On the other hand, the Cone Beam Computed Tomography (CBCT), which offers clear 3-Dimentional (3D) images, has been widely used in orthodontics and implant dentistry for surgical guidance of mini-implant placement.

AIM

The aim of this retrospective study was to evaluate inter-radicular spaces between mandibular canines to second molars using cone beam 3D images.

MATERIALS AND METHODS

In this retrospective cross-sectional descriptive study, maxillofacial CBCT scan data were obtained from 40 adults. The 3D images were evaluated in five axial sections at 2, 4, 6, 8 and 10 mm from the cementoenamel Junction (CEJ). To determine inter-radicular spaces, tangent lines were drawn buccolingually to the roots in axial section and the minimum distance between these two lines was measured. The data was analysed using Friedman test with SPSS(ver.13).

RESULTS

Interradicular spaces of canine to second molar increased from cervical to apical direction. The maximum distance was recorded at 4 mm from the CEJ between first and second molars.

CONCLUSION

According to our findings there is a distinct pattern of inter-radicular space changes in mandible. Attention to this pattern during placement of mini-implants can ensure the safety of the procedure.

Accuracy of Cone-Beam Computed Tomography in Determining the Root Canal Morphology of Mandibular First Molars

Introduction:

The aim of the present in vitro study was to compare the accuracy of cone-beam computed tomography (CBCT) in determining root canal morphology of mandibular first molars in comparison with staining and clearing technique.

Methods and Materials:

CBCT images were taken from 96 extracted human mandibular first molars and the teeth were then evaluated based on Vertucci’s classification to determine the root canal morphology. Afterwards, access cavities were prepared and India ink was injected into the canals with an insulin syringe. The teeth were demineralized with 5% nitric acid. Finally, the cleared teeth were evaluated under a magnifying glass at 5× magnification to determine the root canal morphology. Data were analyzed using the SPSS software. The Fisher’s exact test assessed the differences between the mesial and distal canals and the Cohen’s kappa test was used to assess the level of agreement between the methods. Statistical significance was defined at 0.05.

Results:

The Kappa coefficient for agreement between the two methods evaluating canal types was 0.346 (95% CI: 0.247-0.445), which is considered a fair level of agreement based on classification of Koch and Landis. The agreement between CBCT and Vertucci’s classification was 52.6% (95% CI: 45.54-59.66%), with a significantly higher agreement rate in the mesial canals (28.1%) compared to the distal canals (77.1%) (P<0.001).

Conclusion:

Under the limitations of this study, clearing technique was more accurate than CBCT in providing accurate picture of the root canal anatomy of mandibular first molars.

PEG stabilized DNA – poly(ferrocenylsilane) polyplexes for gene delivery

Polycationic poly(ferrocenylsilane)s (PFS) with tunable amounts of PEG side chains were used for the condensation of DNA into polyplexes of 110 nm in 5.0 mM HEPES.

[Pilot Project: Improved Lung Deposition via a New Nasal Inhalation Procedure]

INTRODUCTION

Inhaled drugs can only be effective if they reach the middle and small airways. This study introduces a system that combines a trans-nasal application of aerosols with noninvasive pressure support ventilation.

METHODS

In a pilot study, 7 COPD patients with GOLD stages II and III inhaled a radiolabeled marker dissolved in water via a trans-nasal route. The mean aerosol particle size was 5.5 µm. Each patient took part in two inhalation sessions that included two application methods and were at least 70 hours apart. During the first session ("passive method"), the patient inhaled the aerosol through an open tube system. The second session ("active method") included pressure support ventilation during the inhalation process. A gamma camera and planar scintigraphy was used to determine the distribution of aerosol particles in the patient's body and lung.

RESULTS

The pressure supported inhalation ("active method") results in an increased aerosol lung deposition compared to the passive method. Above all, we could demonstrate deposition in the lung periphery with relatively large aerosol particles (5.5 µm).

DISCUSSION

The results prove that the combination of trans-nasal inhalation with noninvasive pressure support ventilation leads to significantly increased particle deposition in the lung.

The reliability of clinical decisions based on the cervical vertebrae maturation staging method

OBJECTIVES

Of the various techniques used to determine the optimum timing for growth modification treatments, the cervical vertebrae maturation method has great advantages, including validity and no need for extra X-ray exposure. Recently, the reproducibility of this method has been questioned. The aim of this study was to investigate the cause of poor reproducibility of this method and to assess the reproducibility of the clinical decisions made based on it.

MATERIALS/METHODS

Seventy lateral cephalograms of Iranian patients aged 9‒15 years were observed twice by five experienced orthodontists. In addition to determining the developmental stage, each single parameter involved in this method was assessed in terms of inter- and intra-observer reproducibility. In order to evaluate the reproducibility of clinical decisions based on this method, cervical vertebrae maturation staging (CVMS) I and II were considered as phase 1 and CVMS IV and V were considered as phase 3.

RESULTS

By considering the clinical approach of the CVMS method, inter-observer reproducibility of this method increased from 0.48 to 0.61 (moderate to substantial) and intra-observer reproducibility enhanced from 0.72 to 0.74.

LIMITATIONS

1. Complete visualization of the first four cervical vertebrae was an inclusion criterion, which also limits the clinical application of CVMS method. 2. These results can be generalized when determining growth modification treatments solely for Class II patients.

CONCLUSIONS

Difficulty in determining the morphology of C3 and C4 leads to poor reproducibility of the CVMS method. Despite this, it has acceptable reproducibility in determining the timing of functional treatment for Class II patients.

Antibacterial Effect of All-in-one Self-etch Adhesives on Enterococcus faecalis

Background and aims. The aim of this study was to evaluate the antibacterial activity of one-step self-etch adhesives on Enterococcus faecalis on days 1, 7 and 14 with the use of modified direct contact test.

Materials and methods. The modified directcontact test was used to evaluate the antibacterial effect of Adper Easy One, Bond Force, Clearfil S3 Bond, Futurabond M, G-Bond, iBond and OptiBond All-in-one adhesives on Enterococcus faecalis after aging the samples in phosphate-buffered saline for one, seven and fourteen days. Data were analyzed using one-way ANOVA and post hoc Tukey tests. Aging effect of each adhesive was evaluated by paired-sample test. In this study, P<0.05 was considered significant.

Results. All the tested adhesives exhibited antibacterial activity after one day and had significant differences with the positive control group (P<0.05). After one week, OptiBond All-in-one, iBond and Futurabond M exhibited significant differences in bacterial growth from other groups (P<0.05). There were no significant differences between the groups in two weeks (P>0.05).

Conclusion. iBond exhibited the highest antibacterial effect on E. faecalis after one week. Futurabond and OptiBond All-in-one exhibited antibacterial effects against E. faecalis for one week.

A scanning electron microscope study on the effect of an experimental irrigation solution on smear layer removal

INTRODUCTION

The aim of this in vitro study was to evaluate the effect of an experimental irrigation solution, containing two different concentrations of papain, Tween 80, 2% chlorhexidine and EDTA, on removal of the smear layer.

METHODS AND MATERIALS

Thirty-six single-rooted teeth were divided into two experimental groups (n=12) and two positive and negative control groups of six. The canals were prepared with BioRaCe instruments up to BR7 (60/0.02). In group 1, canals were irrigated with a combination of 1% papain, 17% EDTA, Tween 80 and 2% CHX; in group 2, canals were irrigated with a combination of 0.1% papain, 17% EDTA, Tween 80 and 2% CHX. In group 3 (the negative control), the canal was irrigated with 2.5% NaOCl during instrumentation and at the end of preparation with 1 mL of 17% EDTA was used; in group 4 (positive control), normal saline was used for irrigation. The amount of the remaining smear layer was quantified according to Hulsmann method using scanning electron microscopy (SEM). Data was analyzed by the Kruskal-Wallis and Mann-Whitney tests.

RESULTS

Two-by-two comparisons of the groups revealed no significant differences in terms of smear layer removal at different canal sections between the negative control group (standard regiment for smear layer removal) and 1% papain groups (P<0.05).

CONCLUSION

Under the limitations of the present study, combination of 1% papain, EDTA, 2% chlorhexidine and Tween 80 can effectively remove smear layer from canal walls.

Cone-Beam Computed Tomography Comparison of Canal Transportation after Preparation with BioRaCe and Mtwo Rotary Instruments and Hand K-Flexofiles

INTRODUCTION

The aim of this in vitro study was to evaluate the transportation of mesiobuccal canals of mandibular first molars prepared with either BioRaCe or Mtwo rotary instruments or hand K-Flexofile, by means of cone-beam computed tomography (CBCT).

METHODS AND MATERIALS

Forty-five mandibular molars were selected and randomly divided into three groups (n=15). Mesiobuccal roots of these teeth were prepared by BioRaCe, Mtwo, or hand K-Flexofile. Transportation was measured by pre- and post-operative CBCT images. Two-way ANOVA analysis was applied to detect any differences between the groups followed by the post hoc Tukey's tests. The level of significance was set at 0.05.

RESULTS

The non-parametric Friedman test was used to compare the behavior of each file at 3-, 6- and 9-mm levels. There were no significant differences between different levels in Mtwo group (P=0.15); however, the differences in K-Flexofile and BioRaCe groups were significant (P>0.05). The post hoc Tukey's test revealed significant differences between BioRaCe and K-Flexofile and also between Mtwo and K-Flexofile, both in the 3-mm depths (P<0.05).

CONCLUSION

Under the limitations of the present study, BioRaCe and Mtwo rotary instruments are considered suitable for canal preparation to greater apical sizes provided that the recommended sequences are observed.

Antimicrobial efficacy of photodynamic therapy and sodium hypochlorite on monoculture biofilms of Enterococcus faecalis at different stages of development

BACKGROUND AND OBJECTIVE

As the Enterococcus faecalis biofilm ages, it is likely that bacteria in mature and old biofilms will become more resistant to commonly used antibacterial irrigants. Photodynamic therapy (PDT) has been used to kill resistant bacteria organized in a biofilm. This study aimed to investigate the antimicrobial effectiveness of 1% sodium hypochlorite (NaOCl), 2.5% NaOCl, and PDT on E. faecalis biofilm at different stages of development.

METHODS

In this study 4-, 6-, and 8-week-old E. faecalis biofilms were subjected to one of the following approaches: phosphate-buffered saline solution (PBS), PDT, or 1% and 2.5% NaOCl. Dentin chip suspensions were used for colony forming units (CFU) counting to estimate remaining E. faecalis counts.

RESULTS

PDT and 2.5% NaOCl completely eliminated E. faecalis biofilms in three stages of biofilm development, whereas 1% NaOCl resulted in 81.88%, 85.73%, and 78.62% reductions of bacterial counts in 4-, 6-, and 8-week-old biofilms, respectively, which was significantly more than PBS.

CONCLUSIONS

The bacteria in mature and old biofilms were more resistant to 1% NaOCl than were the bacteria in young biofilms. Overall survival and residual bacteria increase with biofilm aging. PDT and the 2.5% NaOCl solution were equally efficient in completely eliminating E. faecalis biofilms at all three stages.

Microtensile bond strength of self-etch adhesives in different surface conditionings

AIM

Self-etch bonding systems have been introduced recently and have the advantage of reduced operating time. Because of patient management and isolation difficulties in children, the present study aimed to evaluate microtensile bond strength of two self-etch bonding systems (AdheSE and Xeno® III) on cleaned only, ground and sandblasted enamel.

MATERIALS AND METHODS

Thirty intact primary molars were selected and randomly divided into two groups according to the type of bonding used (Xeno® III and AdheSE). The teeth were divided into three subgroups according to enamel surface conditioning method: prophylaxis with pumice, grinding with coarse finishing and polishing disc, and sandblasting with aluminum oxide particles. Tetric Ceram composite then was applied. Samples were sectioned coronally and axially. The interface area of dental sticks was measured and specimens were subjected to a tensile force of 0.5 mm/min until failure.

RESULTS

Microtensile bond strength of Xeno® III-sandblasting, AdheSE-sandblasting, AdheSE-grinding, and AdheSE- cleaned only were 25.5±7.7, 21.2±2.3, 12.9±2.2, and 9.1±1.1, respectively. During sectioning, all specimens of Xeno® III-cleaned only and Xeno® III-grinding groups were fractured.

CONCLUSIONS

Two step AdheSE yields higher mTBS in comparison to one step Xeno ® III. In regard to surface conditioning, sandblasting increases the mTBS relative to grinding with finishing and polishing disc, and the cleaned-only enamel has the lowest mTBS.

Remineralization Effect of Topical NovaMin Versus Sodium Fluoride (1.1%) on Caries-Like Lesions in Permanent Teeth

OBJECTIVE

NovaMin, a synthetic mineral composed of calcium, sodium, phosphorous and silica releases deposits of crystalline hydroxyl-carbonate apatite (HCA) structurally similar to tooth mineral composition. The aim of this investigation was to compare the potential remineralization effect of topical NovaMin and Sodium Fluoride gel on caries like lesions in permanent teeth.

MATERIALS AND METHODS

A total of 60 sound human freshly extracted teeth were subjected to a pH-cycling protocol. Specimens were randomly assigned to one of the two treatment groups with NovaMin contained dentifrice applied to group 1, while group 2 received a dentifrice containing 1.1% neutral Sodium Fluoride. Pastes were applied five times after the samples received a demineralization from an earlier cariogenic challenge. Specimens were then evaluated by a Surface Micro Hardness test (SMH, 25G, 5s). Post-treatment SMH measurements were conducted and Mann Whitney test was employed for statistical analysis.

RESULTS

Mean post lesion SMH values were 221.99±26.27 and 224.50±28.64 for the first and second groups, respectively. Post treatment SMH values were 232.52±24.34 for NovaMin and 232.03 ±24.46 for the fluoride group. Two way ANOVA test showed a highly significant difference between the two different treatment protocols (p<0.001).

CONCLUSION

NovaMin dentifrice appears to have a greater effect on remineralization of carious-like lesions when compared to that of fluoride containing dentifrice in permanent teeth.

Lingual eruption of mandibular permanent incisors: a space correlated phenomenon?

AIM

The aim of the present study was to investigate the prevalence and distribution according to various arch length conditions of lingually erupted mandibular permanent incisors and the effect of space condition on this phenomenon with long-term follow-up of these teeth.

METHODS AND MATERIALS

A total of 105 children aged 5-7.5 years with one or more permanent mandibular incisors erupting lingual to the corresponding primary incisors were included in the study. A space analysis was performed. The subjects were divided into six groups according to various space conditions. The subjects were followed for 2 years.

RESULTS

In this study the prevalence of lingual eruption was 18.4%. Eighty-three point seven percent of the subjects had either equivalent space, mild space excess, or a space deficiency (not more than 3 mm). No relationship was found between groups and clinical outcomes (P>.05). Follow up of the main three groups (according to the space analysis results) revealed in the adequate space group 75% of the children lost their primary incisors without any intervention. Similar outcomes occurred in 85.7% and 57.14% of cases in the mild space excess and space deficiency groups, respectively. Considering the three main groups combined, equivalent space, mild space excess, and mild space deficiency, 70.45% of children lost their primary incisors without any intervention and 14.8% needed primary incisor extraction (17.4%, 14.3%, and 10.7% in each group, respectively).

CONCLUSION

There was no predisposition toward a space deficiency or excess found in these subjects so the wait-and-see policy versus early extraction can be considered for lingually erupting permanent mandibular incisors.

CLINICAL SIGNIFICANCE

Lingual eruption of mandibular incisors is a common clinical problem in the early mixed dentition period that is a source of discomfort for parents of patients with this condition. The present study provides a unique insight into the prevalence of the problem as well as the clinical decisions such as favoring retention of primary incisors as long as possible, the extraction of these primary teeth, placement of lower lingual holding arches, or referral for comprehensive orthodontic treatment. These types of data should not be regarded as standards but as illustrative of several key factors that are still not well-understood or which are still ignored.

TgM2AP participates in Toxoplasma gondii invasion of host cells and is tightly associated with the adhesive protein TgMIC2

Like other members of the medically important phylum Apicomplexa, Toxoplasma gondii is an obligate intracellular parasite that secretes several classes of proteins involved in the active invasion of target host cells. Proteins in apical secretory organelles known as micronemes have been strongly implicated in parasite attachment to host cells. TgMIC2 is a microneme protein with multiple adhesive domains that bind target cells and is mobilized onto the parasite surface during parasite attachment. Here, we describe a novel parasite protein, TgM2AP, which is physically associated with TgMIC2. TgM2AP complexes with TgMIC2 within 15 min of synthesis and remains associated with TgMIC2 in the micronemes, on the parasite surface during invasion and in the culture medium after release from the parasite plasma membrane. TgM2AP is proteolytically processed initially when its propeptide is removed during transit through the golgi and later while it occupies the parasite surface after discharge from the micronemes. We show that TgM2AP is a member of a protein family expressed by coccidian parasites including Neospora caninum and Eimeria tenella. This phylogenic conservation and association with a key adhesive protein suggest that TgM2AP is a fundamental component of the T. gondii invasion machinery.

Chitosan supports the expression of extracellular matrix proteins in human osteoblasts and chondrocytes

The search for biocompatible materials that can support the growth and phenotypic expression of osteoblasts and chondrocytes is a major challenge in the application of tissue engineering techniques for the repair of bone and cartilage defects. Chitosan, a copolymer of glucosamine and N-acetylglucosamine, may provide an answer to this search. Chitosan is the deacetylated product of chitin, a ubiquitous biopolymer found in the exoskeleton of insects and marine invertebrates. Little is known about the utility of chitosan in propagating human osteoblasts and chondrocytes. In this study, we test the hypothesis that chitosan promotes the survival and function of osteoblasts and chondrocytes. Chitosan (4%, w/v in 2% HAc) was coated onto plastic coverslips that had been fitted into 24-well plates. Human osteoblasts and articular chondrocytes were seeded on either uncoated or chitosan-coated coverslips at 1 x 10(5)/cells per well. Cultures were incubated at 37 degrees C, 5% CO(2) for a period of 7 days. Cell viability was assessed at that time using a fluorescent molecular probe. The phenotypic expression of osteoblasts and chondrocytes was analyzed by reverse transcriptase-polymerase chain reaction and immunocytochemistry. Osteoblasts and chondrocytes appeared spherical and refractile on chitosan-coated coverslips. In contrast, greater than 90% of cells on plastic coverslips were elongated and spindle shaped after 7 days of culture. Similar to cells propagated on uncoated control wells, greater than 90% of human osteoblasts and chondrocytes propagated on chitosan remained viable. Human osteoblasts propagated on chitosan films continued to express collagen type I whereas chondrocytes expressed collagen type II and aggrecan, as shown by reverse transcriptase-polymerase chain reaction analysis and immunostaining. The present in vitro work demonstrates the biocompatibility of chitosan as a substrate for the growth and continued function of human osteoblasts and chondrocytes. Chitosan may have potential use as a tissue engineering tool for the repair of osseous and chondral defects.

Chitosan supports the expression of extracellular matrix proteins in human osteoblasts and chondrocytes

The search for biocompatible materials that can support the growth and phenotypic expression of osteoblasts and chondrocytes is a major challenge in the application of tissue engineering techniques for the repair of bone and cartilage defects. Chitosan, a copolymer of glucosamine and N-acetylglucosamine, may provide an answer to this search. Chitosan is the deacetylated product of chitin, a ubiquitous biopolymer found in the exoskeleton of insects and marine invertebrates. Little is known about the utility of chitosan in propagating human osteoblasts and chondrocytes. In this study, we test the hypothesis that chitosan promotes the survival and function of osteoblasts and chondrocytes. Chitosan (4%, w/v in 2% HAc) was coated onto plastic coverslips that had been fitted into 24-well plates. Human osteoblasts and articular chondrocytes were seeded on either uncoated or chitosan-coated coverslips at 1 x 10(5)/cells per well. Cultures were incubated at 37 degrees C, 5% CO(2) for a period of 7 days. Cell viability was assessed at that time using a fluorescent molecular probe. The phenotypic expression of osteoblasts and chondrocytes was analyzed by reverse transcriptase-polymerase chain reaction and immunocytochemistry. Osteoblasts and chondrocytes appeared spherical and refractile on chitosan-coated coverslips. In contrast, greater than 90% of cells on plastic coverslips were elongated and spindle shaped after 7 days of culture. Similar to cells propagated on uncoated control wells, greater than 90% of human osteoblasts and chondrocytes propagated on chitosan remained viable. Human osteoblasts propagated on chitosan films continued to express collagen type I whereas chondrocytes expressed collagen type II and aggrecan, as shown by reverse transcriptase-polymerase chain reaction analysis and immunostaining. The present in vitro work demonstrates the biocompatibility of chitosan as a substrate for the growth and continued function of human osteoblasts and chondrocytes. Chitosan may have potential use as a tissue engineering tool for the repair of osseous and chondral defects.

Proinflammatory cytokine expression of IL-1beta and TNF-alpha by human osteoblast-like MG-63 cells upon exposure to silicon nitride in vitro

This study was designed to determine the effect of Si(3)N(4) disks and particulates on human osteoblast-like MG-63 cells in vitro. The MG-63 (10(5)/mL) cells were plated onto 24-well polystyrene plates fitted with either sintered reaction-bonded (SRBSN) or reaction-bonded (RBSN) 15-mm disks. Controls consisted of wells without Si(3)N(4) disks. Cells propagated at 37 degrees C, 5% CO(2) for 48 h on Si(3)N(4) disks and control polystyrene surfaces exhibited similar proliferative capacities (7000 and 4000 cpm/10(5) cells, respectively, p > 0.05). Cells incubated with 1, 10, or 100 microgram/ml of Si(3)N(4) particles (<1.00 to 5.00 micrometer) for 24 h did not exhibit a decrease in DNA synthetic activity: 12 +/- 1.3 x 10(4), 10.5 +/- 1.5 x 10(4), and 11.0 +/- 1.7 x 10(4) cpm, respectively, compared to 11.6 +/- 2.6 x 10(4) cpm/10(5) for the control cells, as indicated by (3)H-thymidine uptake. Cells propagated on RBSN displayed increased expression of cytokines IL-1beta and TNF-alpha compared to the control cells, as shown by reverse transcriptase-polymerase chain reaction (RT-PCR). In contrast, cells propagated on SRBSN surfaces expressed the same level of IL-1beta and TNF-alpha as that of control cells. Incubation of MG-63 cells with 1-10 microgram/mL of particles did not increase IL-1beta expression. However, at 100 microgram/mL, TNF-alpha expression was greater than that of the control cells. Silicon nitride, evaluated here as disks or as particulates (1-10 microgram/mL), is biocompatible and does not hinder the proliferation or induce proinflammatory cytokine expression of human osteoblast-like MG-63 cells in vitro.

Enhanced proliferation and osteocalcin production by human osteoblast-like MG63 cells on silicon nitride ceramic discs

The biocompatibility of silicon nitride (Si3N4) was assessed in an in vitro model using the human osteoblast-like MG-63 cell line. Cells were propagated on the surface of: reaction-bonded silicon nitride discs, sintered after reaction-bonded silicon nitride discs or control polystyrene surface for 48 h. Compared to cells propagated on polystyrene surface, cells grown on the surface of unpolished silicon nitride discs had significantly lower cell yield and decreased osteocalcin production. In contrast, cells on the surface of polished silicon nitride discs showed similar proliferative capacity to control cells propagated on polystyrene surface. Cells propagated on polished discs also produced higher levels of osteocalcin than cells on unpolished discs. SEM analysis showed cells with well-delineated morphology and cytoplasmic extensions when propagated on polished sintered after reaction-bonded discs. Cells appeared more spherical, when grown on polished reaction-bonded discs. The results of this study suggest that silicon nitride is a non-toxic, biocompatible ceramic surface for the propagation of functional human bone cells in vitro. Its high wear resistance and ability to support bone cell growth and metabolism make silicone nitride an attractive candidate for clinical application. Further studies are needed to explore the feasibility of using silicon nitride clinically as an orthopedic biomaterial.

Human chondrocytes proliferate and produce matrix components in microcarrier suspension culture

Chondrocytes propagated in monolayer culture proliferate and change into 'fibroblastoid'-like cells. This change is characterized by a shift in production of collagen type II to I and from high- to low-molecular-weight proteoglycans. When propagated in three-dimensional culture, chondrocytes have limited ability to divide but re-express their original characteristics. The goal of the present study was to determine whether a microcarrier suspension culture system would support chondrocyte proliferation and phenotype expression. Our experiments indicate that a collagen type I microcarrier (cellagen) best supported chondrocyte proliferation and phenotype expression. Cells in cellagen microcarriers multiplied at least twentyfold within 2 weeks and had doubling times of 2 to 3 d. Viable and metabolically active cells were retrieved with ease. The harvested chondrocytes had no detectable staining for collagen type I and stained intensely for collagen type II. Our studies demonstrate that the microcarrier suspension culture system supports growth and enhances expression of the 'chondrocytic' phenotype. Attachment to a constrained surface and the fluid shear forces on the microcarriers during suspension culture may have helped chondrocytes to reacquire their rounded shape and produce cartilage matrix components.

Primary adenocarcinoma arising in an ileostomy

Two cases are added to the world literature of patients in whom an adenocarcinoma developed at the ileostomy site after total proctocolectomy for ulcerative colitis. Fourteen additional cases have been reported in the world literature; of these, 12 cases have been in patients with ulcerative colitis, and four cases have been in patients with familial adenomatous polyposis. Adenocarcinoma of an ileostomy is not common. However, in the analysis of the reported cases, patients with long-standing ileostomies appear to be at a greater risk. With an aging ileostomy population, an increase in the number of cases may be seen. Three hypotheses are discussed as potential causative pathways to this entity. Continued analysis of these cases may yield information on the pathophysiology involved.

Follicular carcinoma of the thyroid

Follicular carcinoma deserves a careful preoperative evaluation and multidisciplinary therapy planning. Needle aspiration may be of less value than for other thyroid lesions. If the surgeon is suspicious of a carcinoma, a total lobectomy of the involved side and frozen section may be indicated. Lobectomy with or without isthmusectomy seems to be the minimal treatment for tumors confined to the lobe without nodal metastases. Total thyroidectomy is reserved for patients at high risk by nature of age, large lesions, angioinvasion, capsular invasion, or known metastatic disease where subsequent I-131 therapy is considered likely. I-131 scanning for metastatic disease is indicated in these high-risk patients. I-131 therapy is very valuable for treatment of metastatic disease; and in patients presenting with metastatic disease, total thyroidectomy may be indicated to maximize the therapeutic benefit of the I-131. Judicious planning and care of these patients can result in a 50 to 70% total cure and as high as 85% long-term survival.

Pulmonary coin lesions caused by Dirofilaria immitis

The dog heartworm Dirofilaria immitis has been diagnosed by thoracotomy as the etiology of neoplastic-appearing nodules in two patients in the Peoria, Illinois area. This brings the total number of reported cases of human pulmonary dirofilariasis to approximately 81 in the United States. The major concern of this benign disease is that in making the diagnosis the patients undergo the risk of surgery because of the presumed preoperative diagnosis of cancer. Greater awareness of this disease is needed as the geographic distribution of human pulmonary dirofilariasis expands in this country.

Free jejunal graft for repair of cervical esophagus

We have operated upon six patients with cervical esophageal carcinoma and reconstructed these with free jejunal graft. The pathology of all six patients was squamous cell carcinoma, and no patient had apparent distant metastasis. The procedure was a two team approach. While the surgical oncology team resected the esophageal tumor, the microvascular team harvested the jejunal graft. The range of warm ischemia for the free jejunal graft was 1-2.5 hr, and no graft was lost because of recirculation failure. The range of operative time was 5-6.5 hr. There was no operative mortality. There were two minor cervical wound infections, both healed with conservative management. Hospital stay ranged from 10 to 15 days. The swallowing mechanism was satisfactory in all patients. We believe that the free jejunal graft is the procedure of choice for reconstruction of the cervical esophagus.

Recurrence of breast cancer. Obesity, tumor size, and axillary lymph node metastases

Substantially different conclusions have been reached by several studies about relationships between mammary cancer and obesity. We studied retrospectively 106 consecutive patients who underwent mastectomy for breast cancer. We found no association between obesity per se and the frequency or time of recurrence. Our sample did reaffirm that recurrence of breast cancer is related to tumor size and nodal status. Obesity was similarly related to tumor size and nodal status. However, we could not confirm prior findings that obese patients with pathologically similar breast tumors had a poor prognosis.

Cholate sodium infusion for retained common bile duct stones

Eight patients with stones retained in the extrahepatic biliary tract underwent cholate sodium infusion for dissolution of the stones. In six patients, the stones disappeared. However, in two of the patients, the stones did not disappear, and they were removed with the ureteral basket. Infusion of cholate sodium was well tolerated by six patients, but was accompanied by nausea, vomiting, and abdominal pain in two patients. In one case, mucosal deformity of the common bile duct was noticed during the infusion, but it was not apparent on a subsequent cholangiogram. As a result of our experience, we conclude that cholate sodium infusion is a safe procedure for the attempted dissolution of retained common bile duct stones.

Duplication of male urethra

Male urethral duplication is an unusal anomaly with many variants including complete duplication from the bladder to the glans penis as well as incomplete and abortive forms. Two cases are presented of duplication of the male urethra of the epispadiac incomplete type. A chart has been constructed to facilitate categorization of the various forms of urethral duplication in the male.