Clinical Experience Comparison of Foreign-Trained Dentists and Domestic Dental Students: One Institution's Experience.

This study compared the clinical experiences of foreign-trained dentists (FTDs) enrolled in an Advance Standing DMD Dental Program (DMDAS) with those of the domestic dental students (DMD) at the University of Illinois Chicago, College of Dentistry (UIC-COD). A cross-sectional retrospective chart review of patients treated by 295 DMD and 253 DMDAS predoctoral dental students was completed at the UIC-COD. The data were retrieved from the electronic health record system (axiUm) for the graduated classes of 2018, 2019, 2020, 2021, and 2022 on various performed clinical procedures as measured by relative value units (RVUs). The retrieved data were used to compare the clinical experiences of DMDAS vs. DMD students. Descriptive (mean) and statistical (independent t-test) analyses were used (α = 0.05). The results indicated that DMD and DMDAS students had comparable clinical experiences in several disciplines, including diagnosis, prevention, direct/indirect restorations, endodontics, periodontics, complete dentures, removable partial dentures, implants/fixed partial dentures, and oral surgery. There was a statistical difference in total RVUs for diagnosis (p = 0.002) and direct restorations (p < 0.001), in which DMD students had more experience. The 28 month program for FTDs appeared to be a reasonable timeframe to obtain an adequate number of varied clinical experiences as compared with the traditional four-year program at the UIC-COD.

Network analysis reveals aggregation behaviour for an endangered predator at an offshore island.

Site fidelity and aggregation behaviour were assessed for giant sea bass Stereolepis gigas (GSB) at Santa Barbara Island, California, USA, from 2018 to 2020. Results indicate seasonal variation in GSB presence, and network analyses revealed a preferred location in a spatially constrained pattern, indicative of aggregation behaviour. Results show GSB aggregated annually during spawning months in the same location, confirming the first known aggregation of GSB at Santa Barbara Island. Identifying and monitoring aggregation sites is vital to ensuring proper protection and ultimate recovery for this protected species in a changing climate.

Characterization of 475 Novel, Putative Small RNAs (sRNAs) in Carbon-Starved Salmonella enterica Serovar Typhimurium.

An increasingly apparent role of noncoding RNA (ncRNAs) is to coordinate gene expression during environmental stress. A mounting body of evidence implicates small RNAs (sRNAs) as key drivers of Salmonella stress survival. Generally thought to be 50-500 nucleotides in length and to occur in intergenic regions, sRNAs typically regulate protein expression through base pairing with mRNA targets. In this work, through employing a refined definition of sRNAs allowing for shorter sequences and sRNA loci to overlap with annotated protein-coding gene loci, we have identified 475 previously unannotated sRNAs that are significantly differentially expressed during carbon starvation (C-starvation). Northern blotting and quantitative RT-PCRs confirm the expressions and identities of several of these novel sRNAs, and our computational analyses find the majority to be highly conserved and structurally related to known sRNAs. Importantly, we show that deletion of one of the sRNAs dynamically expressed during C-starvation, sRNA4130247, significantly impairs the Salmonella C-starvation response (CSR), confirming its involvement in the Salmonella CSR. In conclusion, the work presented here provides the first-ever characterization of intragenic sRNAs in Salmonella, experimentally confirms that sRNAs dynamically expressed during the CSR are directly involved in stress survival, and more than doubles the Salmonella enterica sRNAs described to date.

Marine deforestation leads to widespread loss of ecosystem function.

Trophic interactions can result in changes to the abundance and distribution of habitat-forming species that dramatically reduce ecosystem functioning. In the coastal zone of the Aleutian Archipelago, overgrazing by herbivorous sea urchins that began in the 1990s resulted in widespread deforestation of the region's kelp forests, which led to lower macroalgal abundances and higher benthic irradiances. We examined how this deforestation impacted ecosystem function by comparing patterns of net ecosystem production (NEP), gross primary production (GPP), ecosystem respiration (Re), and the range between GPP and Re in remnant kelp forests, urchin barrens, and habitats that were in transition between the two habitat types at nine islands that spanned more than 1000 kilometers of the archipelago. Our results show that deforestation, on average, resulted in a 24% reduction in GPP, a 26% reduction in Re, and a 24% reduction in the range between GPP and Re. Further, the transition habitats were intermediate to the kelp forests and urchin barrens for these metrics. These opposing metabolic processes remained in balance; however, which resulted in little-to-no changes to NEP. These effects of deforestation on ecosystem productivity, however, were highly variable between years and among the study islands. In light of the worldwide declines in kelp forests observed in recent decades, our findings suggest that marine deforestation profoundly affects how coastal ecosystems function.

Characterization of novel small RNAs (sRNAs) contributing to the desiccation response of Salmonella enterica serovar Typhimurium.

Noncoding RNA (ncRNA) modulation of gene expression has now been ubiquitously observed across all domains of life. An increasingly apparent role of ncRNAs is to coordinate changes in gene expressions in response to environmental stress. Salmonella enterica, a common food-born pathogen, is known for its striking ability to survive, adapt, and thrive in various unfavourable environments which makes it a particularly difficult pathogen to eliminate as well as an interesting model in which to study ncRNA contributions to cellular stress response. Mounting evidence now suggests that small RNAs (sRNAs) represent key regulators of Salmonella stress adaptation. Approximately 50-500 nucleotides in length, sRNAs regulate gene expression through complementary base pairing with molecular targets and have recently been suggested to outnumber protein-coding genes in bacteria. In this work, we employ small RNA transcriptome sequencing to characterize changes in the sRNA profiles of Salmonella in response to desiccation. In all, we identify 102 previously annotated sRNAs significantly differentially expressed during desiccation; and excitingly, 71 novel sRNAs likewise differentially expressed. Small transcript northern blotting and qRT-PCRs confirm the identities and expressions of several of our novel sRNAs, and computational analyses indicate the majority are highly conserved and structurally related to characterized sRNAs. Predicted sRNA targets include several proteins necessary for desiccation survival and this, in part, suggests a role for desiccation-regulated sRNAs in this stress response. Furthermore, we find individual knock-outs of two of the novel sRNAs identified herein, either sRNA1320429 or sRNA3981754, significantly impairs the ability of Salmonella to survive desiccation, confirming their involvements (and suggesting the potential involvements of other sRNAs we identify in this work) in the Salmonella response to desiccation.

Novel small RNA (sRNA) landscape of the starvation-stress response transcriptome of Salmonella enterica serovar typhimurium.

Small RNAs (sRNAs) are short (∼50-200 nucleotides) noncoding RNAs that regulate cellular activities across bacteria. Salmonella enterica starved of a carbon-energy (C) source experience a host of genetic and physiological changes broadly referred to as the starvation-stress response (SSR). In an attempt to identify novel sRNAs contributing to SSR control, we grew log-phase, 5-h C-starved and 24-h C-starved cultures of the virulent Salmonella enterica subspecies enterica serovar Typhimurium strain SL1344 and comprehensively sequenced their small RNA transcriptomes. Strikingly, after employing a novel strategy for sRNA discovery based on identifying dynamic transcripts arising from "gene-empty" regions, we identify 58 wholly undescribed Salmonella sRNA genes potentially regulating SSR averaging an ∼1,000-fold change in expression between log-phase and C-starved cells. Importantly, the expressions of individual sRNA loci were confirmed by both comprehensive transcriptome analyses and northern blotting of select candidates. Of note, we find 43 candidate sRNAs share significant sequence identity to characterized sRNAs in other bacteria, and ∼70% of our sRNAs likely assume characteristic sRNA structural conformations. In addition, we find 53 of our 58 candidate sRNAs either overlap neighboring mRNA loci or share significant sequence complementarity to mRNAs transcribed elsewhere in the SL1344 genome strongly suggesting they regulate the expression of transcripts via antisense base-pairing. Finally, in addition to this work resulting in the identification of 58 entirely novel Salmonella enterica genes likely participating in the SSR, we also find evidence suggesting that sRNAs are significantly more prevalent than currently appreciated and that Salmonella sRNAs may actually number in the thousands.

Patterns of complementary and alternative medicine (CAM) use among dental patients.

OBJECTIVES: Complementary and alternative medicine (CAM) is a diverse collection of approaches used to prevent or treat diseases. The goal of this study was to examine relationships between dental patient characteristics and current usage of CAM therapies. METHODS: The CAM definition encompassed 24 therapies excluding prayer. Associations and trends in usage were assessed for gender, income, education, and age. Multivariable logistic and negative binomial models were used to identify factors impacting the use and number of CAM therapies used. RESULTS: In dental patients (n = 402), nearly 67 percent of subjects reported at least one CAM treatment. Gender was significantly associated with recent utilization of CAM, biological, manipulative (all P < 0.01), and mind-body (P = 0.04) therapies, as well as the number (P < 0.01) of therapies used. Higher education levels were significant in usage of any CAM, biological, and mind-body therapies (P < 0.01). CONCLUSION: A large proportion of dental patients reported use of CAM therapies. While CAM therapies and those who use them are diverse, given their widespread use, they clearly have potential impacts on the oral health of the public. Knowledge of the characteristics of dental patients who use CAM therapies is a first step in developing a broader understanding how CAM therapies and associated beliefs may affect oral health and public health programs.

Complementary and alternative medicine in predoctoral dental curricula: an exploratory survey of U.S. dental schools.

The purpose of this study was to identify the prevalence of complementary and alternative medicine (CAM) education in U.S. dental schools. A survey was administered via e-mail to each U.S. dental school's academic dean, and data were collected from respondents in a fillable PDF form submitted electronically to the study investigators. The survey asked respondents whether CAM was taught at the institution; if the response was yes, information was requested regarding the CAM therapies included, credentials of the instructor, number of hours taught, reason for teaching CAM, and format in which CAM was taught. Of the sixty dental schools contacted, twenty-two responded to the survey (37 percent response rate). Of these respondents, ten (45.5 percent) reported offering instruction in CAM as part of their predoctoral curricula. Herb/drug interactions were found to be taught with more frequency than any other CAM topic (in six out of the ten institutions). Limitations of the study are discussed, and suggestions for future studies are made.

A pilot study of a chiropractic intervention for management of chronic myofascial temporomandibular disorder.

BACKGROUND: Temporomandibular pain has multiple etiologies and a range of therapeutic options. In this pilot study, the authors assessed the feasibility of conducting a larger trial to evaluate chiropractic treatment of temporomandibular disorders (TMDs). METHODS: The authors assigned 80 participants randomly into one of the following four groups, all of which included a comprehensive self-care program: reversible interocclusal splint therapy (RIST), Activator Method Chiropractic Technique (AMCT) (Activator Methods International, Phoenix), sham AMCT and self-care only. They made assessments at baseline and at month 2 and month 6, including use of the Research Diagnostic Criteria for Temporomandibular Disorders. RESULTS: The authors screened 721 potential participants and enrolled 80 people; 52 participants completed the six-month assessment. The adjusted mean change in current pain over six months, as assessed on the 11-point numerical rating scale, was 2.0 (95 percent confidence interval, 1.1-3.0) for RIST, 1.7 (0.9-2.5) for self-care only, 1.5 (0.7-2.4) for AMCT and 1.6 (0.7-2.5) for sham AMCT. The authors also assessed bothersomeness and functionality. CONCLUSIONS: The authors found the study design and methodology to be manageable. They gained substantial knowledge to aid in conducting a larger study. AMCT, RIST and self-care should be evaluated in a future comparative effectiveness study. PRACTICAL IMPLICATIONS: This pilot study was a necessary step to prepare for a larger study that will provide clinicians with information that should be helpful when discussing treatment options for patients with TMD.

Cavitation in amorphous solids.

Molecular dynamics simulations of cavitation in a Zr(50)Cu(50) metallic glass exhibit a waiting time dependent cavitation rate. On short time scales nucleation rates and critical cavity sizes are commensurate with a classical theory of nucleation that accounts for both the plastic dissipation during cavitation and the cavity size dependence of the surface energy. All but one parameter, the Tolman length, can be extracted directly from independent calculations or estimated from physical principles. On longer time scales strain aging in the form of shear relaxations results in a systematic decrease of cavitation rate. The high cavitation rates that arise due to the suppression of the surface energy in small cavities provide a possible explanation for the quasibrittle fracture observed in metallic glasses.

Complementary and alternative medicine usage by patients of a dental school clinic.

This pilot study investigated the prevalence and specific reasons for usage of complementary and alternative medicine (CAM) among patients of a dental school clinic. Four hundred and two patients completed a 30-page survey on CAM usage. A higher rate of CAM usage was found in this dental school clinic population than rates previously reported in a general population. More than three-quarters (76.1%) of the respondents reported using at least one CAM treatment in the past 12 months; 93.3% reported using at least one CAM treatment at some time in their lives. High rates of chiropractic use were found in this population. Tooth pain was the most frequently reported dental condition motivating CAM use. About 10% of dental school clinic patients use topical oral herbal and/or natural products to treat dental conditions, most frequently for preventive/oral health reasons or for tooth pain.

The use of a respiratory rate biofeedback device to reduce dental anxiety: an exploratory investigation.

Anxiety experienced by individuals visiting the dental office to receive treatment is common. Evidence has shown biofeedback to be a useful modality of treatment for numerous maladies associated with anxiety. The purpose of the current pilot study was to investigate the use of a novel biofeedback device (RESPeRATE™) to reduce patients' pre-operative general anxiety levels and consequently reduce the pain associated with dental injections. Eighty-one subjects participated in this study, forty in the experimental group and forty-one in the control group. Subjects in the experimental group used the biofeedback technique, while those in the control group were not exposed to any biofeedback. All subjects filled out a pre-injection anxiety survey, then received an inferior alveolar injection of local anesthetic. Post-injection, both groups were given an anxiety survey and asked to respond to four questions regarding the injection experience using a Visual Analog Scale (VAS). With the use of the respiratory rate biofeedback device, there was a significant reduction of negative feelings regarding the overall injection experience, as measured by a VAS. Our findings demonstrate that this novel biofeedback technique may be helpful in the amelioration of dental anxiety, and may help produce a more pleasant overall experience for the patient.

Periplasmic peptidyl-prolyl isomerases SurA and FkpA play an important role in the starvation-stress response (SSR) of Salmonella enterica serovar Typhimurium.

Carbon-energy source (C)-starved cells of Salmonella enterica serovar Typhimurium (S. Typhimurium) are remarkably more resistant to stress than actively growing ones. Carbon-starved S. Typhimurium is capable of withstanding extended periods of starvation and assault from a number of different stresses that rapidly kill growing cells. These unique properties of the C-starved cell are the direct result of a series of genetic and physiological adaptations referred to as the starvation-stress response (SSR). Previous work established that the SSR of S. Typhimurium is partially regulated by the extracytoplasmic function sigma factor sigma(E). As part of an effort to identify sigma(E)-regulated SSR genes, we investigated surA and fkpA, encoding two different classes of peptidyl-prolyl isomerase that function in folding cell envelope proteins. Both surA and fkpA are members of the heat-shock-inducible sigma(E) regulon of Escherichia coli. Although both genes are expressed in C-starved Salmonella cells, evidence indicates that surA and fkpA are not C-starvation-inducible. Furthermore, their expression during C-starvation does not appear to be sigma(E)-dependent. Nonetheless, surA and fkpA proved to be important, to differing degrees, for long-term C-starvation survival and for the cross-resistance of C-starved cells to high temperature, acidic pH, and the antimicrobial peptide polymyxin B, but neither were required for cross-resistance to oxidative stress. These results point to fundamental differences between heat-shock-inducible and C-starvation-inducible genes regulated by sigma(E) and suggest that genes other than surA and fkpA are involved in the sigma(E)-regulated branch of the SSR in Salmonella.

Correlation of quantity of dental students' clinical experiences with faculty evaluation of overall clinical competence: a twenty-two-year retrospective investigation.

The purpose of this study was to investigate the correlation between the quantity of a student's clinical experiences in the final year of dental school and the student's overall clinical competence at graduation, as evaluated by faculty at the University of Iowa College of Dentistry. Further, the authors sought to determine whether this correlation changed over time, as new generations of students come to dental school. Information including year of graduation, age at graduation, final grade in the course Clinical Competencies in Comprehensive Care, and final total Clinical Experience Units (CEUs) earned by each student in the D4 Family Dentistry Clinic was collected for 1987-2008 graduates of the University of Iowa College of Dentistry. Spearman's rank correlation coefficient (r(s)) was computed for the association of final clinical course grade and final CEU total for each graduation year. The correlation between final course grade and final CEU total was variable, ranging from moderately strong (r(s)=0.614, Class of 1991) to negligible (r(s)=-0.013, Class of 2008). This correlation generally tended to become weaker over time. The results of this study suggest that the terminal quality of a dental student's work is not solely a function of repetitions of prescribed procedures and that repetition of procedures may have even less influence on the quality of clinical performance for the new generation of dental students.

Associations among predental credentials and measures of dental school achievement.

The purpose of this study was to investigate the associations among several dental school admission criteria and several measures of dental school achievement. Data were collected for 2000-07 University of Iowa dentistry graduates, including five specific preadmission credentials and five specific measures of dental school achievement for each student. Pearson product moment correlations or Mann-Whitney U statistics were computed for the association of each of the ten variables with the nine others. The strongest correlation observed was between predental science grade point average (GPA) and overall predental GPA. Dental Admission Test (DAT) Academic Average was very strongly correlated with DAT Total Science, and both of these were each moderately correlated with DAT Perceptual Ability, predental science GPA, and overall predental GPA. Among the measures of dental school achievement, the strongest association was observed between National Board Dental Examination (NBDE) scores and dental school GPA. These were also moderately correlated with final clinical grade. All of the measures of dental school achievement were slightly stronger for candidates who passed the Central Regional Dental Testing Service (CRDTS) examination than for those who failed that exam. Of the predental credentials considered, predental science GPA and overall predental GPA were the best predictors of dental school GPA. DAT Academic Average was the best predictor of NBDE scores. Although DAT Perceptual Ability was the best predictor of clinical competency at the time of graduation, these two variables were only weakly correlated. DAT Perceptual Ability scores and overall predental GPA were slightly higher for candidates who passed the CRDTS examination than for those who failed that exam.

Sigma(s)-Dependent carbon-starvation induction of pbpG (PBP 7) is required for the starvation-stress response in Salmonella enterica serovar Typhimurium.

Carbon-energy source starvation is a commonly encountered stress that can influence the epidemiology and virulence of Salmonella enterica serovars. Salmonella responds to C-starvation by eliciting the starvation-stress response (SSR), which allows for long-term C-starvation survival and cross-resistance to other stresses. The stiC locus was identified as a C-starvation-inducible, sigma(S)-dependent locus required for a maximal SSR. We report here that the stiC locus is an operon composed of the yohC (putative transport protein) and pbpG (penicillin-binding protein-7/8) genes. yohC pbpG transcription is initiated from a sigma(S)-dependent C-starvation-inducible promoter upstream of yohC. Another (sigma(S)-independent) promoter, upstream of pbpG, drives lower constitutive pbpG transcription, primarily during exponential phase. C-starvation-inducible pbpG expression was required for development of the SSR in 5 h, but not 24 h, C-starved cells; yohC was dispensable for the SSR. Furthermore, the yohC pbpG operon is induced within MDCK epithelial cells, but was not essential for oral virulence in BALB/c mice. Thus, PBP 7 is required for physiological changes, occurring within the first few hours of C-starvation, essential for the development of the SSR. Lack of PBP 7, however, can be compensated for by further physiological changes developed in 24 h C-starved cells. This supports the dynamic overlapping and distinct nature of resistance pathways within the Salmonella SSR.

Pushing the envelope: extracytoplasmic stress responses in bacterial pathogens.

Despite being nutrient rich, the tissues and fluids of vertebrates are hostile to microorganisms, and most bacteria that attempt to take advantage of this environment are rapidly eliminated by host defences. Pathogens have evolved various means to promote their survival in host tissues, including stress responses that enable bacteria to sense and adapt to adverse conditions. Many different stress responses have been described, some of which are responsive to one or a small number of cues, whereas others are activated by a broad range of insults. The surface layers of pathogenic bacteria directly interface with the host and can bear the brunt of the attack by the host armoury. Several stress systems that respond to perturbations in the microbial cell outside of the cytoplasm have been described and are known collectively as extracytoplasmic or envelope stress responses (ESRs). Here, we review the role of the ESRs in the pathogenesis of Gram-negative bacterial pathogens.

Prenatal diagnosis of ventriculocoronary arterial communication in fetuses with hypoplastic left heart syndrome.

OBJECTIVE: The purpose of this series was to describe the fetal echocardiographic findings in hypoplastic left heart syndrome with aortic atresia and ventriculocoronary arterial communication and implications of these findings. METHODS: We describe 2 fetuses with hypoplastic left heart syndrome with ventriculocoronary arterial communication diagnosed at 29 and 20 weeks' gestation, respectively. The underlying cardiac anatomy consisted of a hypoplastic left heart and mitral stenosis with aortic atresia. We used color Doppler and pulsed Doppler sonography on the surface of the myocardium to specifically look for coronary arterial flow. RESULTS: By color Doppler sonography, ventriculocoronary arterial communication was shown between the left ventricular cavity and the left coronary artery with characteristic bidirectional flow on pulsed Doppler examination. There was no mitral regurgitation. The left ventricular myocardium was substantially hypertrophied. The first patient underwent surgical Norwood palliation and died after a prolonged postoperative course. The second patient underwent stenting of the arterial duct and bilateral pulmonary artery banding in the catheterization laboratory but died after a few weeks. Implications of ventriculocoronary arterial communication in association with hypoplastic left heart syndrome are discussed. CONCLUSIONS: It is possible to accurately diagnose ventriculocoronary arterial communication on fetal echocardiography. The presence of ventriculocoronary arterial communication is seen exclusively in a subgroup of patients with an aortic atresia and mitral stenosis variant of hypoplastic left heart syndrome. The prognosis is poor in this subgroup of patients.

Fetal echocardiographic diagnosis of vascular rings.

OBJECTIVE: The purpose of this series is to describe the prenatal echocardiographic findings of vascular rings. METHODS: The 3-vessel and trachea view consists of the axial view of the upper mediastinum. The normal left aortic arch appears as a V-shaped confluence of the ductus arteriosus and aortic arch, with the trachea situated posterior and to the right. No vessel should encircle the trachea. The diagnoses of vascular rings were made prenatally and were confirmed in all patients postnatally. RESULTS: Six fetuses had diagnoses of vascular rings. The mean gestational age at diagnosis was 23.3 weeks (range, 18-31 weeks). The indications for fetal echocardiography were family history of congenital heart disease, echogenic focus in the left ventricle, and abnormal 4-chamber view. There were 2 fetuses with a double aortic arch; 3 fetuses with a right aortic arch, an aberrant left subclavian artery, and a left ductus arteriosus; and 1 with a right circumflex aortic arch with a left ductus arteriosus and an aberrant left subclavian artery. Two fetuses had associated structural cardiac defects, 1 with an unbalanced atrioventricular septal defect and trisomy 21 and the other with a double-outlet right ventricle, pulmonary atresia, and multiple other congenital anomalies. CONCLUSIONS: Vascular rings can be accurately diagnosed prenatally with recognition of a vascular structure that courses around the trachea and absence of the usual V-shaped relationship of the aortic and ductal arches. The color Doppler findings and the presence of a ductus arteriosus aid in identifying various components of the vascular ring.