Diffusion-Weighted Magnetic Resonance Imaging Is an Ideal Imaging Method to Detect Infection in Pancreatic Collections: A Brief Primer for the Gastroenterologists.

BACKGROUND: The development of infection in pancreatitis significantly increases the mortality rate up to 100% in the absence of any intervention. Therefore, it is extremely important to diagnose these cases at an early stage. The objectives of this study were to assess the diagnostic performance of computed tomography (CT) and diffusion-weighted MR imaging (DW-MRI) in the diagnosis of infection in pancreatic collections. MATERIALS AND METHODS: Prospective observational study of abdominal collections due to pancreatitis that underwent both CT and DW-MRI from August 2018 to July 2020 were enrolled in the study. The collections were analysed for infections - air foci in CT and diffusion restriction on DW-MRI. RESULTS: Of the 39 patients recruited in the study, infected collections were present in 17, and 22 cases had sterile collections. On CT, air foci within the collection were present only in seven of the cases in our study (sensitivity 35%, specificity 95.4%, PPV 85.7%, NPV 65.6%). DW-MRI detected infection in all 17 cases (sensitivity 100%, specificity 72.7%, PPV 74%, NPV 100%). DISCUSSION: Thirteen out of 17 collections suspicious for infection on DW-MR showed microbiological growth on culture examination. We believe that this is likely due to the patient's prior antibiotic use, which might have altered the micro-environment or inflammatory cell and bacterial content of the collection. CONCLUSION: DW-MRI is complementary and superior to CT in detecting infection in pancreatic collections. CT may be used to detect disease burden, extent and vascular complication.

Quantitative diffusion-weighted magnetic resonance imaging for prediction of early infection in pancreatic collections: Results of a pilot study.

BACKGROUND/AIMS: The development of infection in pancreatitis increases the mortality rate up to 32%. Therefore, it is important to identify patients who are at high risk of developing infection, at an early stage. The objectives of the study were (a) to analyze the quantitative parameters of diffusion-weighted magnetic resonance imaging (DW-MRI) and apparent diffusion coefficient (ADC) in infected as well as sterile pancreatic collections (b) to establish "cut-off" values for ADC that can identify infected pancreatic collections. MATERIALS AND METHODS: Prospective observational study of pancreatitis cases who underwent DW-MRI from August 2018 to July 2019 were enrolled in the study. The collections were analyzed for diffusion restriction. The average of the three ADC values from the wall and center of collection was noted. RESULTS: Infected collections were seen in 7 and sterile collections observed in 11 cases. The optimal cut-off ADC value to differentiate sterile and infected collection in our study was 1.651 × 10-3 mm2/s (sensitivity of 81.8%; specificity of 100.0%). ROC curve for mean ADC from the wall showed a significant diagnostic accuracy with AUC: 0.91; 95% CI: 0.77-1.0 (P = 0.004). CONCLUSION: DW-MRI is a reliable noninvasive technique to differentiate sterile and infected pancreatic collections. ADC values from the periphery of the collection can predict infected pancreatic collections at an early stage. DW-MRI should not be considered as a substitute for aspiration cytology in patients with septic symptoms and absent diffusion restriction on MRI.

A review of translational medicine. The future paradigm: how can we connect the orthopedic dots better?

INTRODUCTION: Patients with complex medical and surgical problems often travel great distances to prestigious university medical centers in search of solutions and in some cases for nothing more than a diagnosis of their condition. Translational medicine (TM) is an emerging method and process of facilitating medical advances efficiently from the scientist to the clinician. Most established clinicians and those in training know very little about this new discipline. The purpose of this article is to illustrate TM in varied scientific, medical and surgical fields. MATERIALS AND METHODS: Anecdotal events in medicine and orthopaedics based upon a practicing orthopaedic surgeon's training and clinical experience are presented. RESULTS: TM is rapidly assuming a greater presence in the medical community. The National Institute of Health (NIH) recognizes this discipline and has funded TM projects. Numerous institutions in Europe and the USA offer advanced degrees in TM. Finally there is a European Society for Translational Medicine (EUTMS), an International Society for Translational Medicine, and an Academy of Translational Medical Professionals (ATMP). DISCUSSION: The examples of TM presented in this article support the argument for the formation of more TM networks on the local and regional levels. The need for increased participation of researchers and clinicians requires further study to identify the economic and social impact of TM. CONCLUSIONS: The examples of TM presented in this article support the argument for the formation of more TM networks on the local and regional levels. Financial constraints for TM can be overcome by pooling government, academic, private, and industry resources in an organized fashion with oversight by a lead TM researcher.

Remineralization Potential of Three Tooth Pastes on Enamel Caries.

BACKGROUND: Different formulations of dentifrices exist in the market. Usually, single toothpaste is used by all family members including children. There is a big concern of fluoride ingestion with the toothpaste containing high fluoride content in children. Recently, new toothpaste (including toothpaste) with remineralization potential without fluoride content has been formulated. AIM: There is an urgent need to compare remineralization potential of this new formulation with the exiting dentifrices. Therefore, the present study has been undertaken to assess and compare the remineralization potential of three dentifrices with different compositions on artificially induced carious lesions in vitro by using scanning electron microscopy and polarised light microscopy. MATERIALS AND METHODS: The present in vitro study was conducted on 21 healthy extracted primary central incisor teeth surfaces, which were divided into three groups and were treated by three different dentifrices. Artificial demineralization was followed by remineralization using dentifrice slurry as per the group distribution. All the samples were studied for remineralization by using scanning electron microscopy and polarised light microscopy. Data were analysed using SPSS version 11 software. RESULTS: A significant difference was found between the remineralization potential of incudent toothpaste and other toothpaste groups based on the analysis of polarised light microscopy and stereomicroscope. The remineralizing ability of incudent toothpaste for artificial enamel lesions was found to be significantly higher than that of Colgate® and Crest toothpaste. CONCLUSIONS: The limitations of this study include, being a short term study, low sample size and in vitro experiment. incudent toothpaste has exhibited a higher remineralizing potential as compared to fluoride based toothpaste in our study.

sTNF-R Levels: Apical Periodontitis Linked to Coronary Heart Disease.

BACKGROUND: Different studies have implicated the exposure to systemic conditions in the aetiology of cardiovascular diseases like chronic inflammation including chronic periodontitis. AIM: The present study has been conducted to examine whether biomarker sTNF-R was elevated in apical periodontitis as sTNF-R is a systemic marker of inflammation and has been identified as risk factors for cardiovascular diseases. MATERIAL AND METHODS: sTNF-R levels were measured in 52 patients with apical periodontitis (M:F::25:27), aged 20-45 years and in 20 control patients without periodontitis (M:F::10:10, aged 20-48 years). Measurement of sTNF-R1 and sTNF-R2 was carried out in duplicate with standardised, commercially available enzyme immunoassays (R&D Systems Europe, Abingdon, UK). RESULTS: The mean sTNF-R1 and sTNF-R2 levels in periodontitis were 820 (240) pg/ml (413 - 1620 pg/ml) and 1309 (403) pg/ml (540 - 2430 pg/ml), while in normal sTNF-R1 and sTNF - R2 levels were 740 (340) pg/ml (407-1240 pg/ml) and 1283 (414) pg (480 - 2340 pg/ml) respectively. Results indicated a positive high relationship between cardiovascular markers such as sTNF-R1 and sTNF - R2 and apical periodontitis. CONCLUSION: Elevated levels of sTNF-R1 and sTNF - R2 in apical periodontitis patients indicate an increased independent risk of coronary heart disease.

Periodontal status, salivary immunoglobulin, and microbial counts after short exposure to an isolated environment.

Salivary flow rate, immunoglobulin, and periodontal status were affected during a simulated Skylab mission. The effect is more prominent after long-duration space flights and can persist for several weeks after landing. The objective of this study was to determine the effect of a simulated Mars environment on periodontal status and levels of salivary microorganisms and immunoglobulins in the human oral cavity. Twelve healthy male volunteers were studied before, at 1 and 2 weeks, and after completion of a mission in an isolated, confined simulated Mars environment at the Mars Desert Research Station, USA. We conducted a current stress test, measured salivary immunoglobulin, cortisol, α-amylase, salivary flow rate, and levels of plaque and salivary microbes, and assessed clinical periodontal parameters (probing depth, bleeding on probing, and clinical loss of attachment). Salivary IgG levels and Streptococcus mutans activity were significantly higher at 1 week. Values for clinical periodontal parameters (probing depth, bleeding on probing, and clinical loss of attachment) significantly differed at 1 week. Stress might be caused by the difficulty of the mission rather than the isolated environment, as mission duration was quite short. Periodontal condition might worsen due to poor oral hygiene during the mission. The present findings show that all periodontal conditions and levels of oral bacteria and stress after completion of the simulated Mars mission differed from those at baseline. To verify the relationship between stress status and periodontal health in simulated Mars missions, future studies using larger patient samples and longer follow-up will be required.

Association between stress, sleep quality and temporomandibular joint dysfunction: simulated Mars mission.

OBJECTIVES: The aim of this study was to test the association between quality of sleep and stress in individuals with TMD (temporomandibular joint dysfunction) in simulated Mars mission. METHODS: The 24 healthy crew members were recruited. The physiological measures of systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) were recorded. The Symptom Checklist-90-revised was used which was based on nine dimensions of psychological functioning. The Multidimensional Pain Inventory was pain severity, social and physical activities, affective distress, social support, and feelings of life control. The Pittsburgh Sleep Quality Index was used to measure the number of hours spent in bed and during asleep, frequency and reasons for awakening, and difficulty returning to sleep after awakening. The orofacial pain questionnaire was applied to measure pain experience using descriptors from the McGill Pain Questionnaire. Salivary cortisol and melatonin were measured. RESULTS: The 15 crew members reported temporomandibular joint pain after 6 days of mission. On dental examination, 5 crew members reported simple muscle pain (SM) and other 10 crew members with TMD. The TMD group endorsed more affective descriptors of their pain experience. Compared to the TMD group, the SM group also reported significantly poorer sleep duration. The TMD group reported nonsignificantly more daytime dysfunction than the control. Higher levels of salivary cortisol and salivary melatonin were reported in the TMD group as compared to other group. CONCLUSION: This study concludes that both quality of sleep and stress levels due to extreme condition (simulated Mars mission) were associated with TMD in simulated Mars mission.

Human Factor Studies on a Mars Analogue During Crew 100b International Lunar Exploration Working Group EuroMoonMars Crew: Proposed New Approaches for Future Human Space and Interplanetary Missions.

Knowing the risks, costs, and complexities associated with human missions to Mars, analogue research can be a great (low-risk) tool for exploring the challenges associated with the preparation for living, operating, and undertaking research in interplanetary missions. Short-duration analogue studies, such as those being accomplished at the Mars Desert Research Station (MDRS), offer the chance to study mission operations and human factors in a simulated environment, and therefore contribute to exploration of the Moon and Mars in planned future missions. This article is based upon previously published articles, abstracts, and presentations by a series of independent authors, human factor studies performed on mars analogue station by Crew 100B. The MDRS Crew 100B performed studies over 15 days providing a unique insight into human factor issues in simulated short-duration Mars mission. In this study, 15 human factors were evaluated and analyzed by subjective and objective means, and from the summary of results it was concluded that optimum health of an individual and the crew as a whole is a necessity in order to encourage and maintain high performance and the satisfaction of project goals.

Mental and physical workload, salivary stress biomarkers and taste perception: Mars desert research station expedition.

BACKGROUND: Very few studies have been conducted on the effects of simulation of Mars conditions on taste. AIMS: This study was planned to find the effects of physical and mental workload on taste sensitivity and salivary stress biomarkers. MATERIALS AND METHODS: Twelve crew members were selected. Taste reactions and intensity of the taste sensations to quinine sulfate, citric acid, and sucrose were tested before and after mental and physical tasks for one hour. Also, psychological mood states by profile of mood state, salivary, salivary alpha amylase and cortisol, and current stress test scores were measured before and after mental and physical tasks. RESULTS: Average time intensity evaluation showed that after the mental and physical tasks, the perceived duration of bitter, sour, and sweet taste sensations was significantly shortened relative to control group. There were good correlations between average time intensity of sweetness, bitterness, sourness and cortisol levels. CONCLUSIONS: Taste alterations due to stress can have an effect on the health and confidence of astronauts in long- term space missions. Thus, this issue remains one of the important issues for future human explorations.

Stress, workload and physiology demand during extravehicular activity: a pilot study.

BACKGROUND: Extravehicular activity (EVA), such as exercise performed under unique environmental conditions, is essential for supporting daily living in weightlessness and for further space exploration like long Mars mission. AIM: The study was planned stress, workload, and physiological demands of simulated Mars exploration. MATERIALS AND METHODS: In this study, the six-person crew lived (24 hours) for 14 days during a short-term stay at the Mars Desert Research Station. The heart rates, salivary cortisol, workload, peak oxygen uptake or maximal aerobic capacity of the crew are measured before, during and after an EVA. RESULTS: Data for heart rate showed the same trend as peak oxygen uptake or maximal aerobic capacity, with a maximal increase to 85% of peak. The rating of subscale showed a significant increase in EVA as compared to run. Salivary cortisol levels and heart rates were increased in both groups, although significant increased of cortisol levels and heart rates more in EVA as compared to hill running crew members. CONCLUSION: Further study is required on large scale taken into account of limitations of this study and including other physiological and psychological parameters in Mars analog environment.

Salivary amylase and stress during stressful environment: three Mars analog mission crews study.

After the establishment of the space age physicians, human factors engineers, neurologist and psychologists and their special attention to work on people's capability to meet up the physical, psychological, neuroscience and interpersonal strains of working in space, it has been regarded as an issue that seeks urgent consideration. Not study was conducted on effect of simulated Mars analog environment on stress and salivary amylase. So, this study aimed to confirm whether salivary amylase is act as stress biomarker in crew members who took part in Mars analog mission in an isolated and stressful environment. The 18 crew members were selected who took part in Mars Analog Research Station, Utah. Salivary amylase was measured using a biosensor of salivary amylase monitor and State-Trait Anxiety Inventory score at pre-extravehicular activity, post-extravehicular activity and on before mission. The state and trait anxiety scores at pre-extravehicular activity for each commander were elevated as compared to after extravehicular activity. There were significant differences in the state and trait anxiety scores between before extravehicular activity and after extravehicular activity of Commander and other members, also there were significant differences in values of before-extravehicular activity between commanders and other members. There were significant differences in values of salivary amylase at before extravehicular activity and after extravehicular activity between commander group and other members. There was significant correlation between salivary amylase and state and trait anxiety scores in all groups. Measuring salivary amylase level could be useful for stress assessment of crew members and population working in a stressful and isolated environment.

Working hours, sleep, salivary cortisol, fatigue and neuro-behavior during Mars analog mission: five crews study.

The buoyancy of humans in exploring extreme space environments has been established during missions to the moon. Long duration missions like mission to Mars however, requires humans to adapt to systemic and complex environments beyond the human body's capacity. Astronauts will encounter both physiological and psychological extremes during this trip. Very few studies are conducted on effect of long duration work and sleepiness on cognitive performance. So, this study was planned to find out effects of leadership responsibility, sleepiness and long duration working hours on cognitive performance. The 30 members (leadership: normal; 10:20) were selected from MDRS crews (Mars Desert Research Station, USA). Neurobehavioral test performance, self-ratings of fatigue and sleepiness, and salivary cortisol levels were evaluated during first day, mid and end day of mission. The leadership group did not show any signs of reduced test performance, even in elevated fatigue and sleepiness. The leadership group had faster reaction times on end of mission as compared to first and after 7 day of mission. Salivary cortisol levels were significantly higher in leadership group as compared to normal group. The results suggest that long duration work and sleepiness does not affect the cognitive performance of crew member. Further study is required while taking into account all factors and large sample size to prove this fact.

Wound healing and mucosal immunity during short Mars analog environment mission: salivary biomarkers and its clinical implications.

OBJECTIVE: Wound healing in an extreme environment with micro-gravity is not well characterized, despite the likelihood that the increasing use of manned spaceflight as a research and commercial enterprise raises the probability of traumatic injury in this state. Hence, this study was conducted to determine the impact of the isolated environment of the Mars Desert Research Station on mucosal immunity and wound healing. MATERIALS AND METHODS: Two punch biopsy wounds were placed on the hard palate of two crewmembers. The first wound was made during summer vacation, whereas the second was placed on the contra-lateral side 3 days before the Mars analog mission began. Thus, each crewmember served as his/her own control. Two independent methods were used to assess healing. A ten-item perceived stress scale, salivary cortisol, Immunoglobulin A, IgG and IgM were measured. RESULTS: There were significant differences in the proportion of the wound size healed between vacation and the mission. Salivary IgA, IgM, IgG and cortisol levels showed significant differences between vacation and mission. CONCLUSION: These data suggest that stress can have significant consequences for wound healing. The effects of stress on wound repair could have important clinical implications, including for recovery from surgery.

Possible relationship between periodontitis and dementia in a North Indian old age population: a pilot study.

BACKGROUND: Periodontitis and cognitive impairment or dementia is relatively common among older adults. Few cross-sectional studies and some longitudinal studies have attempted to link oral health with dementia diagnosis or disease pathology but none has investigated the role of inflammation as a potential mediator. OBJECTIVES: This study was planned to establish a relation of inflammatory mediators between periodontitis and dementia. MATERIALS AND METHODS: Fifty-five patients with severe periodontitis (range 60-69 years), 20 with dementia (10:10 M:F; range 59-69) and 32 healthy controls (range 58-69 years) were selected. The socio-demographic characteristics, physical health, oral health, education status, and medical status were measured. Serum C-reactive protein (CRP), matrix metalloproteinase (MMP)-8, MMP-9, total IGF-I, free IGF-I and TNF-alpha and GCF MMP-8 &MMP-9 were calculated. RESULTS: There was no significant difference between the three groups in the level of education, age, occupation, BMI, CAD, CHF and diabetes except dentate status. After adjusting for age, significant differences were found between patients and controls with respect to gingival inflammation, dental plaque, bleeding on probing and probing pocket depth. Total counts of WBCs, neutrophils, thrombocytic counts and serum CRP, MMP-8, MMP-9, TNF-alpha levels were significantly higher in dementia and periodontitis patients in contrast to healthy controls, while, RBC counts, total IGF-I and Hb levels were lowered in dementia and periodontitis patients in comparison to healthy controls, although higher in dementia as compared to periodontitis patients. CONCLUSIONS: This study data suggest a relationship of inflammatory mediators between periodontitis and dementia. Further exploration of this is warranted.

Evaluation by an aeronautic dentist on the adverse effects of a six-week period of microgravity on the oral cavity.

Objective. HDT bed rest condition is a simulated microgravity condition in which subject lies on bed inclined -6 degree feet up. To determine the influence of a simulated microgravity (HDT bed rest) on oral cavity, 10 healthy male volunteers were studied before, during, just after, and after 6 weeks of the simulated microgravity condition of -6° head-down-tilt (HDT) bed rest. Materials and Methods. Facial nerve function, facial sensation, chemosensory system, salivary biomarkers were measured. Results. Lactate dehydrogenase, MIP 1 alpha, malonaldehyde, 8-hydroxydeoxyguanosine, and thiocyanate were found to increase significantly, while flow rate, sodium, potassium, calcium, phosphate, protein, amylase activity, vitamin E and C, and mouth opening were decreased in simulation environments in contradiction to normal. The threshold for monosodium glutamate (MSG) and capsaicin increased during microgravity as compared to normal conditions. Moderate pain of teeth, facial oedema, mild pain, loss of sensation of pain and temperature, decreased tongue, and mandibular movement in simulation microgravity environments were observed. Conclusions. These results suggest that reversible effect of microgravity is oedema of face, change in taste, abnormal expression of face, teeth pain, and xerostomia. Further study will be required on large scale on long-term effects of microgravity on oral cavity to prevent the adverse effects.

The history and importance of aeronautic dentistry.

Current projected missions to Mars will require 18 to 24 months of exposure to microgravity conditions, which might have serious effects on human physiology, including that of the oral cavity. Very few studies have been published on the effect of microgravity on the oral cavity, although it has been reported that microgravity increases the prevalence of periodontitis, dental caries, bone loss and fracture in the jaw bone, pain and numbness in teeth and oral cavity tissue, salivary duct stones, and oral cancer. Aeronautic dentistry is a new field, so further study of the effects of microgravity are required. In this article, we review the role of aeronautic dentistry in space missions and offer our recommendations for the future growth of this field.

Salivary stress markers and psychological stress in simulated microgravity: 21 days in 6° head-down tilt.

Spaceflight occurs in an environment of temperature extremes, microgravity, solar and galactic cosmic radiation, lack of atmospheric pressure, and high-speed micrometeorites. Exposure to microgravity and the space environment during space missions of short and long duration has important medical and health implications for astronauts. Psychological well-being is of increasing importance in planned spaceflights and interplanetary missions of long duration. The 6° head-down tilt (HDT) is an established method of mimicking low gravity on earth. The aim of the present study was to determine the effects of 21 days of HDT on psychological stress in 12 healthy male volunteers. Psychological state was assessed by the current stress test, and chromogranin-A (CgA), cortisol, alpha-amylase, and beta-endorphin were measured in saliva. After one week of HDT, all volunteers developed psychological stress, and secretion of CgA, cortisol, alpha-amylase, and beta-endorphin were all significantly higher. Thus, 6° HDT appears to be a valid model to induce psychological stress changes in the immune system, changes that might also be encountered by astronauts and cosmonauts during both a short stay in space, such as that required while orbiting a space station, and in longer spaceflights.

Effect of simulated microgravity on salivary and serum oxidants, antioxidants, and periodontal status.

BACKGROUND: Microgravity is associated with an increase in peroxidative damage. The effect is more pronounced after long-duration space flights and can even last for several weeks after landing. The objective of the study is to determine the influence of simulated microgravity on the periodontal status and salivary and serum oxidant/antioxidant status of the body in simulated microgravity (-6° head-down-tilt [HDT) bed rest). METHODS: Twenty healthy male volunteers were studied before and after 60 days of simulated microgravity (-6° HDT bed rest). We measured salivary and serum oxidative markers, such as malondialdehyde (MDA), 8-oxo-7,8 dihydro-2 deoxyguanosine (8-OHdG), and vitamins C and E, and clinical periodontal parameters (probing depth [PD] and clinical attachment level [CAL]). RESULTS: Serum and salivary vitamin C and E concentrations were significantly decreased, whereas MDA and 8-OHdG levels were significantly increased after 60 days of simulated microgravity. Serum and salivary markers showed a strong and significant correlation. CAL and PD were higher but not statistically significant in simulated microgravity. CONCLUSIONS: This study suggests that oxidative stress in the microgravity environment was increased but did not significantly influence periodontal parameters after 2 months. Also, this study indicates the possibility that the findings may have a broader clinical relevance to patients on bed rest or who are physically inactive. Studies on larger patient samples and follow-up for a longer time are required to verify the relationship between antioxidant status in the space microgravity condition and periodontal health.

Salivary stress markers, stress, and periodontitis: a pilot study.

BACKGROUND: Some cross-sectional and longitudinal studies attempted to link periodontitis with stress. To our knowledge, only one small study was published on the mechanism by which stress may influence periodontal diseases, suggesting behavioral and physiologic mechanisms and investigating the role of inflammation as a potential mediator. The present study is planned to explore the associations among periodontal disease, psychologic factors, and salivary markers of stress, psychoneuroimmunologic variables, and health behaviors. METHODS: One hundred periodontitis patients were selected, and participants provided information on general health, chronic stress, and demographics. Stress markers (choromogranin A, cortisol, α-amylase, and ß-endorphin) were measured from saliva. A dentist assessed the presence of dental plaque on lingual and buccal surfaces, the gingival index, and the number of remaining teeth with periodontal disease. RESULTS: Stress and salivary stress markers were significantly correlated with clinical parameters of periodontal disease (ranging from 0.19 to 0.59; P <0.001). Neglecting to brush teeth during stress was associated with missing teeth. After adjusting for stress variables, salivary cortisol and ß-endorphin were significantly associated with tooth loss and periodontal clinical parameters (P <0.001; R(2) = 0.59). CONCLUSIONS: This study suggests that stress might be associated with periodontal disease through physiologic and behavioral mechanisms. In making diagnoses of psychiatric patients, the association between salivary stress markers and periodontal disease needs to be included. Further exploration of relationships between periodontitis and stress is warranted.