Vitamin D Sufficiency: How Should it be Defined and what are its Functional Indicators?

Hollis Broce W. The Korean Nutrition Society 2005 Nutritional Sciences Vol.8 No.2

It has been more than three decades since the first assay assessing circulating 25 (OH)D in human subjects was performed That publication as well as several that followed it defined 'normal' nutritional vitamin D status in human populations. Recently, the wisdom by which 'normal' circulating 25 (OH)D levels in human subjects were assigned in the past has come under question. It appears that sampling human subjects, who appear to be free from disease, and assessing 'normal' circulating 25 (OH)D levels by plotting a Gaussian distribution is grossly inaccurate. There are many reasons why this method is inaccurate, including race, lifestyle habits, sunscreen usage, age, latitude, and inappropriately low dietary recommendations for vitamin D. For instance, a 400 IU/day. AI for vitamin D is insignificant when one considers that a 10-15 minute whole body exposure to peak summer sun will generate and release up to 20,000 IU vitamin $D_3$ into the circulation. Recent studies, which orally administered up to 10,000 IU/day vitamin $D_3$ to human subjects for several months, have successfully elevated circulating 25 (OH)D levels to those observed in individuals from sun-rich environments. Further, we are now able to accurately assess sufficient circulating 25 (OH)D levels utilizing specific biomarkers instead of guessing what an adequate level is. These biomarkers include intact parathyroid hormone (PTH), calcium absorption, bone mineral density (BMD), insulin resistance and pancreatic beta cell function. Using the data from these biomarkers, vitamin D deficiency should be defined as circulating levels of 25 (OH)D$\leq$30 ng/mL. In certain cases, such as pregnancy and lactation, significantly higher circulating 25 (OH)D levels would almost certainly be beneficial to both the mother and recipient fetus/infant.

Competition Policy in Open Economies

Hollis, Aidan,Yuan, Lasheng 한국국제경제학회 2004 International Economic Journal Vol.18 No.2

What is the effect of national antitrust policies in a world with international trade? Traditionally, economic analysis of mergers has assumed a closed economy, which as we show in this paper, may lead to errant policy in an open economy. We use a very simple model to highlight some key issues in optimal competition policy when trade is important, and compare the nationally optimal number of firms with the globally optimal number of firms in a free trade environment. We show that countries will choose a competition policy that is “too strict” in the sense that they will prefer to have more firms than is globally optimal, implying that convergence in competition policy should generally lead to a reduction in the number of firms. We also examine the strategic interaction between domestic and foreign competition policy when there is free trade and show that small and large countries will react very differently to changes in the other's policies.

Vitamin D Sufficiency: How Should it be Defined and what are its Functional Indicators?

Bruce W. Hollis 한국영양학회 2005 Nutritional Sciences Vol.8 No.2

Total Ankle Arthroplasty: An Imaging Overview

김다래,최윤선,Hollis G. Potter,Angela E. Li,전가영,정윤영,김진수,양기원 대한영상의학회 2016 Korean Journal of Radiology Vol.17 No.3

With advances in implant technology, total ankle arthroplasty (TAA) has become an increasingly popular alternative to arthrodesis for the management of end-stage ankle arthritis. However, reports in the literature do not focus on the imaging features of TAA. Through a literature review, we demonstrate basic design features of the current ankle arthroplasty system, and the normal and abnormal postoperative imaging features associated with such devices. Pre- and postoperative evaluations of ankle arthroplasty mainly include radiography; in addition, computed tomography and magnetic resonance imaging provide further characterization of imaging abnormalities. Familiarization with multimodal imaging features of frequent procedural complications at various postoperative intervals is important in radiological practice.

Differential subcellular localization of DNA topoisomerase-1 isoforms and their roles during <i>Caenorhabditis elegans</i> development

Cha, Dong Seok,Hollis, Sarah E.,Datla, Udaya Sree,Lee, Sejin,Ryu, Jinsun,Jung, Hey Rim,Kim, Eunsuk,Kim, Kyuhyung,Lee, Myeongwoo,Li, Chris,Lee, Myon-Hee Elsevier 2012 Gene expression patterns Vol.12 No.5

<P><B>Highlights</B></P><P>► TOP-1β is broadly expressed in the nuclei of cells and concentrated in nucleoli. ► TOP-1α is specifically localized to centrosomes, neuronal cells, excretory cells and chromosomes of germ cells. ► TOP-1 proteins are required for chromosomal segregation and germline development in <I>Caenorhabditis elegans</I>.</P> <P><B>Abstract</B></P><P>DNA topoisomerase-1 (TOP-1) resolves the topological problems associated with DNA replication, transcription and recombination by introducing temporary single-strand breaks in the DNA. <I>Caenorhabditis elegans</I> TOP-1 has two isoforms, TOP-1α and TOP-1β. TOP-1β is broadly localized to the nuclei of many cells at all developmental stages and concentrated in nucleoli in embryo gut and oogenic cells. However, TOP-1α is specifically localized to centrosomes, neuronal cells, excretory cells and chromosomes of germ cells in embryonic and larval stages. Reporter gene analysis also shows that <I>top-1</I> transcription is highly activated in several sensory neurons, speculating the possible role of TOP-1α in neuronal development. From RNA interference (RNAi) experiments, we demonstrated that <I>C. elegans</I> TOP-1 is required for chromosomal segregation, germline proliferation and gonadal migration, which are all correlated with the expression and activity of TOP-1. Therefore, our findings may provide an insight into a new role of TOP-1 in development of multicellular organisms.</P>

Grit and Children’s Taekwondo Performance

Sawyer, Thomas P.,Hollis-Sawyer, Lisa,Wade, James 국제무예학회 2018 International Journal of Martial Arts Vol.4 No.-

The present research examined psychological grit and sports-related performance outcomes with n = 102 taekwondo students and their parents. The focus of the study was to evaluate how psychological grit relates to taekwondo students’ practice and assessment (i.e., testing and competition) outcomes. The results of the study were predominantly supportive of the hypotheses. “Instructor-rated” grit was significantly related to students’ testing performance, tournament attendance, and attrition while “parent-rated” grit was only significantly related to students’ testing performance. Possible reasons for the differences between the sources are discussed, such as the possibility that the two rater sources may have utilized different observational opportunities. Implications of the findings on the significance of grit are discussed including the creation of adaptive instructional techniques and curriculum in response to students’ level of grit.

Administration order of midazolam/fentanyl for moderate dental sedation

Lobb, Douglas,Clarke, Alix,Lai, Hollis The Korean Dental Society of Anesthsiology 2018 Journal of Dental Anesthesia and Pain Medicine Vol.18 No.1

Background: The purpose of this study is to investigate the effects of administration order when a sedative drug (midazolam) and an opioid analgesic drug (fentanyl) is applied for moderate intravenous (IV) sedation in dentistry. Methods: A retrospective chart review was conducted in one dental clinic during its transition from a midazolam-first to a fentanyl-first protocol for dental procedures requiring moderate IV sedation. Physiological parameters, drug administration times, patient recovery times, drug dosages, and patient recall and satisfaction were investigated for differences. Results: A total of 76 charts (40 midazolam-first and 36 fentanyl-first administrations), were used in the analysis. Administering midazolam first resulted in an average 4.38 min (52%) decrease in administration times (P < 0.001), and a decrease in procedural recollection immediately following the procedure (P = 0.03), and 24 to 48 hours later (P = 0.009). Administering fentanyl first required an average of 2.43 mg (29%) less midazolam (P < 0.001). No significant differences were found for change in vital signs, minimum oxygen saturation levels, recovery times, and patient satisfaction (P > 0.05). Oxygen saturation levels did not drop below 90% for either group; however, 5 cases in the fentanyl-first group fell to between 90% and 92%, compared with 0 cases in the midazolam-first group. Conclusions: The administration order of fentanyl and midazolam may have different effects on patients and the sedation procedure. Findings from this study should be used to facilitate discussion among dental practitioners and to guide additional research investigating this topic.

Comparison of the effects of target-controlled infusion-remifentanil/midazolam and manual fentanyl/midazolam administration on patient parameters in dental procedures

Doug Lobb,Nazila Ameli,Silvia Ortiz,Hollis Lai 대한치과마취과학회 2022 Journal of Dental Anesthesia and Pain Medicine Vol.22 No.2

Background: Moderate sedation is an integral part of dental care delivery. Target-controlled infusion (TCI) has the potential to improve patient safety and outcome. We compared the effects of using TCI to administer remifentanil/manual bolus midazolam with manual bolus fentanyl/midazolam administration on patient safety parameters, drug administration times, and patient recovery times. Methods: In this retrospective chart review, records of patients who underwent moderate intravenous sedation over 12 months in a private dental clinic were assessed. Patient indicators (pre-, intra-, and post-procedure noninvasive systolic and diastolic blood pressure, respiration, and heart rate) were compared using independent t-test analysis. Patient recovery time, procedure length, and midazolam dosage required were also compared between the two groups. Results: Eighty-five patient charts were included in the final analysis: 47 received TCI-remifentanil/midazolam sedation, and 38 received manual fentanyl/midazolam sedation. Among the physiological parameters, diastolic blood pressure showed slightly higher changes in the fentanyl group (P = 0.049), respiratory rate changes showed higher changes in the fentanyl group (P = 0.032), and the average EtCO2 was slightly higher in the remifentanil group (P = 0.041). There was no significant difference in the minimum SpO2 levels and average procedure length between the fentanyl and remifentanil TCI pump groups (P > 0.05). However, a significant difference was observed in the time required for discharge from the chair (P = 0.048), indicating that patients who received remifentanil required less time for discharge from the chair than those who received fentanyl. The dosage of midazolam used in the fentanyl group was 0.487 mg more than that in the remifentanil group; however, the difference was not significant (P > 0.05). Conclusion: The combination of TCI administered remifentanil combined with manual administered midazolam has the potential to shorten the recovery time and reduce respiration rate changes when compared to manual administration of fentanyl/midazolam. This is possibly due to either the lower midazolam dosage required with TCI remifentanil administration or achieving a stable, steady-state low dose remifentanil concentration for the duration of the procedure.

Numerical analysis of weld pool oscillation in laser welding

조정호,Dave F. Farson,Kendall J Hollis,John O. Milewski 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.4

Volume of fluid (VOF) numerical simulation was used to investigate melt flow and volumetric oscillation of conduction-mode pulsedlaser weld pools. The result is compared to high speed video stream of titanium laser spot welding experiment. The total simulation timeis 10ms with the first 5 ms being heating and melting under constant laser irradiation and the remaining 5 ms corresponding to resolidificationof the weld pool. During the melting process, the liquid pool did not exhibit periodic oscillation but was continually depressedby the evaporation recoil pressure. After the laser pulse, the weld pool was excited into volumetric oscillation by the release ofpressure on its surface and oscillation of the weld pool surface was analyzed. The simulation model suggested adjusting thermal diffusivityto match cooling rate and puddle diameter during solidification which is distinguishable from previous weld pool simulation. Thefrequency continuously increased from several thousand cycles per second to tens of thousands of cycles per second as the weld poolsolidified and its diameter decreased. The result is the first trial of investigation of small weld pool oscillation in laser welding althoughthere have been several reports about arc welding.

Safety and efficacy of target controlled infusion administration of propofol and remifentanil for moderate sedation in non-hospital dental practice

Douglas Lobb,Masoud MiriMoghaddam,Don Macalister,David Chrisp,Graham Shaw,Hollis Lai 대한치과마취과학회 2023 Journal of Dental Anesthesia and Pain Medicine Vol.23 No.1

Background: Fearful and anxious patients who find dental treatment intolerable without sedative and analgesic support may benefit from moderate sedation. Target controlled infusion (TCI) pumps are superior to bolus injection in maintaining low plasma and effect-site concentration variability, resulting in stable, steady-state drug concentrations. We evaluated the safety and efficacy of moderate sedation with remifentanil and propofol using TCI pumps in non-hospital dental settings. Methods: A prospective chart review was conducted on 101 patients sedated with propofol and remifentanil using TCI pumps. The charts were completed at two oral surgeons and one general dentist's office over 6 months. Hypoxia, hypotension, bradycardia, and over-sedation were considered adverse events and were collected using Tracking and Reporting Outcomes of Procedural Sedation (TROOPS). Furthermore, patient recovery time, sedation length, drug dose, and patient satisfaction questionnaires were used to measure sedation effectiveness. Results: Of the 101 reviewed sedation charts, 54 were of men, and 47 were of women. The mean age of the patients was 40.5 ±18.7 years, and their mean BMI was 25.6 ± 4.4. The patients did not experience hypoxia, bradycardia, and hypotension during the 4694 min of sedation. The average minimum Mean Arterial Pressure (MAP) and heartbeats were 75.1 mmHg and 60.4 bpm, respectively. 98% of patients agreed that the sedation technique met their needs in reducing their anxiety, and 99% agreed that they were satisfied with the sedation 24 hours later. The average sedation time was 46.9 ± 55.6 min, and the average recovery time was 12.4 ± 4.4 min. Remifentanil and propofol had mean initial effect-site concentration doses of 0.96 µ/.ml and 1.0 ng/ml respectively. The overall total amount of drug administered was significantly higher in longer sedation procedures compared to shorter ones, while the infusion rate decreased as the procedural stimulus decreased. Conclusion: According to the results of this study, no patients experienced adverse events during sedation, and all patients were kept at a moderate sedation level for a wide range of sedation times and differing procedures. The results showed that TCI pumps are safe and effective for administering propofol and remifentanil for moderate sedation in dentistry.