Assessment of Postoperative Swelling and Pain Following Alveolar Ridge Preservation with Different Biomaterials: A Randomized Controlled Trial.

Background: This randomized controlled trial aimed to assess and compare postoperative swelling and pain in patients undergoing alveolar ridge preservation using RidgeMax Pro and AlveoGraft Plus. Methods: A total of 20 patients requiring tooth extraction were enrolled in this study and randomly assigned to two groups: Group A received alveolar ridge preservation with RidgeMax Pro and Group B with AlveoGraft Plus. Postoperative swelling was evaluated by measuring facial dimensions using standardized facial photographs at baseline and at 24, 48, and 72 hours postoperatively. Pain was assessed using a visual analog scale (VAS) at the same time points. Statistical analysis was performed using t-tests and repeated measures ANOVA. Results: Both RidgeMax Pro and AlveoGraft Plus demonstrated effective alveolar ridge preservation without any reported complications. In terms of postoperative swelling, Group A (RidgeMax Pro) exhibited significantly lower facial swelling compared to Group B (AlveoGraft Plus) at all time points (P < 0.05). The mean pain scores on the VAS were consistently lower in Group A than in Group B across the assessment time points (P < 0.05). The trend of reduced swelling and pain in Group A persisted throughout the 72-hour follow-up period. Conclusion: Alveolar ridge preservation with RidgeMax Pro (Trade Name: RidgeMax Pro) resulted in significantly reduced postoperative swelling and pain compared to AlveoGraft Plus (Trade Name: AlveoGraft Plus).

How do psychobehavioural variables shed light on heterogeneity in COVID-19 vaccine acceptance? Evidence from United States general population surveys on a probability panel and social media.

OBJECTIVES: To (1) understand what behaviours, beliefs, demographics and structural factors predict US adults' intention to get a COVID-19 vaccination, (2) identify segments of the population ('personas') who share similar factors predicting vaccination intention, (3) create a 'typing tool' to predict which persona people belong to and (4) track changes in the distribution of personas over time and across the USA. DESIGN: Three surveys: two on a probability-based household panel (NORC's AmeriSpeak) and one on Facebook. SETTING: The first two surveys were conducted in January 2021 and March 2021 when the COVID-19 vaccine had just been made available in the USA. The Facebook survey ran from May 2021 to February 2022. PARTICIPANTS: All participants were aged 18+ and living in the USA. OUTCOME MEASURES: In our predictive model, the outcome variable was self-reported vaccination intention (0-10 scale). In our typing tool model, the outcome variable was the five personas identified by our clustering algorithm. RESULTS: Only 1% of variation in vaccination intention was explained by demographics, with about 70% explained by psychobehavioural factors. We identified five personas with distinct psychobehavioural profiles: COVID Sceptics (believe at least two COVID-19 conspiracy theories), System Distrusters (believe people of their race/ethnicity do not receive fair healthcare treatment), Cost Anxious (concerns about time and finances), Watchful (prefer to wait and see) and Enthusiasts (want to get vaccinated as soon as possible). The distribution of personas varies at the state level. Over time, we saw an increase in the proportion of personas who are less willing to get vaccinated. CONCLUSIONS: Psychobehavioural segmentation allows us to identify why people are unvaccinated, not just who is unvaccinated. It can help practitioners tailor the right intervention to the right person at the right time to optimally influence behaviour.

Long-Term Usage of Oral Glucocorticoids Leading to Adrenal Insufficiency: A Comprehensive Review of the Literature.

Systemic glucocorticoid therapy is used worldwide by one to three percent of the general population and 0.5-1.8% on long-term oral glucocorticoid use. It is widely used in conditions such as inflammation, autoimmune diseases, and cancer to inhibit inflammatory responses. One of the possible undesirable side effects of exogenous corticosteroid treatment is adrenal suppression upon discontinuation of the medication and adrenal insufficiency after utilizing the supraphysiologic doses for more than one month. To prevent patients from the unwanted signs and symptoms of adrenal insufficiency, including fatigue, gastrointestinal upset, anorexia/weight loss, etc., better management of the quantity and frequency of exogenous corticosteroid use, as well as better education before starting its use, is needed. For patients actively on exogenous corticosteroids, a close follow-up must be in place to avoid adrenal suppression after the eventual discontinuation of their use. This review article summarizes the important studies to date on this subject, especially oral glucocorticoid use, and analyzes risks such as dose, duration of exposure, and comorbidities of adrenal insufficiency associated with oral glucocorticoid use. We comprehensively include information on those with primary adrenal insufficiency and pediatric patients, hoping to provide better insight and clinical reference.

The prevalence, angiographic profile and clinical features, management, and outcomes of coronary artery perforation secondary to percutaneous coronary interventions in Pakistan: a retrospective cohort study.

Coronary artery perforation (CAP) is a rare entity that is often fatal. The mortality rates reported as high as up to 21% hence prompt diagnosis, intervention, and treatment are paramount to survival for such patients. Several factors may predispose a patient to coronary artery intervention including chronic total occlusion, severe calcification and tortuosity, aggressive use of oversized balloons and stents, and use of athero-ablative devices. Therefore, it is significant to have an insight related to it as despite being rare, it is one of the most feared complications of percutaneous coronary intervention (PCI). Method: We conducted a retrospective study of the patients who have undergone PCI at our institution from January 2015 to December 2021. During this duration, all the patients who had developed CAP based on angiographic review during the PCI were selected. The demographic, clinical, angiographic, procedure-related features, management of the CAP, and in-hospital and follow-up outcomes were gathered. Result: Thirty-five thousand fifty-nine patients underwent PCI among which, only 93 (0.26%) patients were complicated with (CAP. Fifty-eight (62.4%) patients were in the 50-70 years age range. The most common vessel involved was the left anterior descending (36.5%) followed by the right coronary artery (32.3%). The angiographic calcification was present in 51.6% of patients, significant tortuosity greater than 90° was seen in 48.4% of patients, chronic total occlusion was observed in 42% of patients and In-stent restenosis was found in 8.6% patients. The highest mortality of four patients was seen in the CAP involving the right coronary artery. Conclusion: Mostly the CAP involves large vessel perforations however both, the distal and large vessel perforations are related to the increased incidence of adverse clinical results which indicates the significance of the prevention and early identification and treatment of the perforation.

Treatment with Testosterone Therapy in Type 2 Diabetic Hypogonadal Adult Males: A Systematic Review and Meta-Analysis.

Testosterone replacement therapy (TRT) has been used to treat hypogonadal males with type 2 diabetes mellitus (T2DM) for a long time, despite variable results. This meta-analysis examines TRT's role in hypogonadal males with T2DM. The databases PubMed, Embase, and Google Scholar were searched for relevant RCTs and observational studies. Estimated pooled mean differences (MDs) and relative risks with 95% confidence intervals were used to measure the effects of TRT (CIs). When compared to the placebo, TRT improves glycemic management by significantly reducing glycated hemoglobin (HBA1c) levels (WMD = -0.29 [-0.57, -0.02] p = 0.04; I2 = 89.8%). Additionally, it reduces the homeostatic model assessment levels of insulin resistance (WMD = -1.47 [-3.14, 0.19]; p = 0.08; I2 = 56.3%), fasting glucose (WMD = -0.30 [-0.75, 0.15]; p = 0.19; I2 = 84.4%), and fasting insulin (WMD = -2.95 [-8.64, 2.74]; however, these results are non-significant. On the other hand, HBA1c levels are significantly reduced with TRT; in addition, total testosterone levels significantly increase with testosterone replacement therapy (WMD = 4.51 [2.40, 6.61] p = 0.0001; I2 = 96.3%). Based on our results, we hypothesize that TRT can improve glycemic control and hormone levels, as well as lower total cholesterol, triglyceride, and LDL cholesterol levels while raising HDL cholesterol in hypogonadal type 2 diabetes patients. To this end, we recommend TRT for these patients in addition to standard diabetes care.

Implant-Supported Overdenture Using Ball Attachments in Maxilla and Mandible: A Case Report.

Implant-supported overdentures are advantageous over conventional dentures, as they improve patient esthetics and enable retention, stability, comfort, and psychological well-being of the patient. This article describes a simple chairside technique for loading maxillary and mandibular dentures onto implant ball attachments.

A meta-analysis: incidental intraductal papillary mucinous neoplasm and extra-pancreatic malignancy.

INTRODUCTION: Meta-analysis aimed to quantify the relationship between intraductal papillary mucinous neoplasm (IPMN) and increased incidence of extra-pancreatic malignancy (EPM) previously reported in qualitative observational cohort studies. METHODS: Study protocol was registered with PROSPERO (CRD42020169614) and conducted to the Meta-analysis Of Observational Studies in Epidemiology and systematic review reported with Preferred Reporting Items for Systematic Reviews and Meta-Analyses, Assessing the Methodological Quality of Systematic Reviews guidelines. RESULTS: Sixteen studies (total of 8240 patients) were included in the pooled, and 7399 patients in the subgroup meta-analyses. The odds ratio (OR) for any EPM in the presence of IPMN was 57.9 (95% confidence interval 40.5-82.7), fixed effects, I2 = 59% (p < 0.0014). Subgroup analysis for any gastrointestinal EPM (i.e. oesophagus, stomach, colon and rectum) in the presence of an IPMN estimated an overall OR of 12.9 (95% confidence interval 8.8-19.0), fixed effects, I2 = 64% (p < 0.0004). CONCLUSION: Patients with an IPMN are categorically at increased risk for a higher incidence of EPM and particularly the odds of a gastrointestinal malignancy are also increased in comparison with the general population. We advocate that patients presenting with an IPMN should be considered for gastrointestinal screening including colonoscopy, upper gastrointestinal endoscopy or computed tomography.

A comparison of the inflammatory response following autologous compared with allogenic islet cell transplantation.

BACKGROUND: The initial response to islet transplantation and the subsequent acute inflammation is responsible for significant attrition of islets following both autologous and allogenic procedures. This multicentre study compares this inflammatory response using cytokine profiles and complement activation. METHODS: Inflammatory cytokine and complement pathway activity were examined in two cohorts of patients undergoing total pancreatectomy followed either by autologous (n=11) or allogenic (n=6) islet transplantation. Two patients who underwent total pancreatectomy alone (n=2) served as controls. RESULTS: The peak of cytokine production occurred immediately following induction of anaesthesia and during surgery. There was found to be a greater elevation of the following cytokines: TNF-alpha (P<0.01), MCP-1 (P=0.0013), MIP-1α (P=0.001), MIP-1ß (P=0.00020), IP-10 (P=0.001), IL-8 (P=0.004), IL-1α (P=0.001), IL-1ra (0.0018), IL-10 (P=0.001), GM-CSF (P=0.001), G-CSF (P=0.0198), and Eotaxin (P=0.01) in the allogenic group compared to autografts and controls. Complement activation and consumption was observed in all three pathways, and there were no significant differences in between the groups although following allogenic transplantation ∆IL-10 and ∆VEGF levels were significantly elevated those patients who became insulin-independent compared with those who were insulin-dependent. CONCLUSIONS: The cytokine profiles following islet transplantation suggests a significantly greater acute inflammatory response following allogenic islet transplantation compared with auto-transplantation although a significant, non-specific inflammatory response occurs following both forms of islet transplantation.

Diagnostic Challenges in Canine Parvovirus 2c in Vaccine Failure Cases.

In this study, three different diagnostic tests for parvovirus were compared with vaccination status and parvovirus genotype in suspected canine parvovirus cases. Faecal samples from vaccinated (N17) and unvaccinated or unknown vaccination status (N41) dogs that had clinical signs of parvovirus infection were tested using three different assays of antigen tests, conventional and quantitative PCR tests. The genotype of each sample was determined by sequencing. In addition to the suspected parvovirus samples, 21 faecal samples from apparently healthy dogs were tested in three diagnostic tests to evaluate the sensitivity and specificity of the tests. The antigen test was positive in 41.2% of vaccinated dogs and 73.2% of unvaccinated diseased dogs. Conventional PCR and qPCR were positive for canine parvovirus (CPV) in 82.4% of vaccinated dogs and 92.7% of unvaccinated dogs. CPV type-2c (CPV-2c) was detected in 82.75% of dogs (12 vaccinated and 36 unvaccinated dogs), CPV-2b was detected in 5.17% dogs (one vaccinated and two unvaccinated) and CPV-2a in 1.72% vaccinated dog. Mean Ct values in qPCR for vaccinated dogs were higher than the unvaccinated dogs (p = 0.049), suggesting that vaccinated dogs shed less virus, even in clinical forms of CPV. CPV-2c was the dominant subtype infecting dogs in both vaccinated and unvaccinated cases. Faecal antigen testing failed to identify a substantial proportion of CPV-2c infected dogs, likely due to low sensitivity. The faecal samples from apparently healthy dogs (n = 21) showed negative results in all three tests. Negative CPV faecal antigen results should be viewed with caution until they are confirmed by molecular methods.

Pilot study: deficiency of mannose-binding lectin-dependent lectin pathway, a novel modulator in outcome from pancreatic islet auto-transplantation.

BACKGROUND: Numerous factors influence pancreatic islet survival following auto-transplantation. Of these, the host immune response in the early peri-operative period is one of the most important. In this study we investigated the role of the mannose-binding lectin (MBL)-dependent pathway in a group of total pancreatectomy (TP) islet auto-transplantation (TPIAT) patients and classified them as competent or deficient in MBL activity. Complement pathway activities, MBL protein and inflammatory cytokine concentrations were evaluated from eleven pancreatic islet auto-transplant patients from two institutions. METHODS: Eleven patients from two institutions were prospectively recruited. Serum was screened at different time points for 29 different cytokines and compared according to their MBL deficient or competent status. Twelve patients from previous TPIAT patients also underwent screening of MBL pathway activity. RESULTS: A total nine of twenty three patients (39%) were MBL pathway deficient. MCP-1, IL-7 and IL-1a concentrations were significantly lower in the MBL deficient cohort compared to the normal MBL group (P=0.0237, 0.0001 and 0.0051 respectively). IL-6 and IL-8 concentrations were significantly raised in the normal MBL group. MBL functional activity was lower in insulin-independent group compared to the insulin-dependent group. CONCLUSIONS: Complement activation is an important, possibly damaging response during intra-portal islet infusion. MBL pathway deficiency appears common in this population and the cytokine response was attenuated in MBL pathway deficient patients. Therapeutic MBL pathway blockade during and following islet auto-transplantation (IAT) may improve islet survival and function and thereby clinical outcome.

Adherence to Levothyroxine Tablet in Patients with Hypothyroidism.

Introduction Patients with hypothyroidism are managed with life-long levothyroxine (LT4) therapy. However, as with other chronic illnesses, drug adherence (DA) is a prominent issue in these patients. The aim of this study is to identify the extent of DA to LT4 in hypothyroidism patients and study the clinical factors contributing to DA in these patients. Methods This cross-sectional study assessed patient adherence to LT4 therapy by Modified Morisky Adherence Scale (MMAS). Factors predicting the pattern of medication adherence were also assessed in all patients. Data were entered and analyzed using SPSS v. 22.0. Results On MMAS, 79 (27.3%) participants indicated low adherence, 117 (40.48%) indicated medium adherence, and 93 (32.2%) participants indicated high adherence. Regular endocrinologist visits and knowledge about medication were highest in high adherent patients (p < 0.05). Need for assistance in taking medication, avoidance of medication with symptomatic relief and busy work schedule was highest in low adherent patients (p < 0.05). Conclusion Patients with hypothyroidism showed moderate adherence to their treatment.

An ex vivo porcine spleen perfusion as a model of bacterial sepsis.

An ex vivo, porcine spleen perfusion model was established to study the early events occurring in the spleen prior to the onset of bacterial sepsis, using organs retrieved from animals slaughtered for food production. Porcine spleens were harvested from adult pigs and connected to a normothermic extracorporeal perfusion circuit. A constant perfusion of heparinized blood was performed for 6 hours. After injection of Streptococcus pneumoniae to the circuit serial samples of both blood and spleen biopsies were collected and analysed. Functionality of the perfused organs was assessed by monitoring the blood-gas parameters, flow rate and filtering capability of the organ. Interestingly, we observed full clearance of bacteria from the blood and an increase in bacterial counts in the spleen. Classical histology and immunohistochemistry on biopsies also confirmed no major damages in the organ architecture and changes in the immune cell distribution, other than the presence of clusters of pneumococci. A time-course study confirmed that each focus of infection derived from the replication of single pneumococcal cells within splenic macrophages. The model proposed - in line with the 3Rs principles - has utility in the replacement of experimental animals in infection research. Murine models are prevalently used to study pneumococcal infections, but are often not predictive for humans due to substantial differences in the immune systems of the two species. This model is designed to overcome these limitations, since porcine immunology and splenic architecture in particular, closely resemble those of humans.

Structural and Biochemical Studies of Non-native Agonists of the LasR Quorum-Sensing Receptor Reveal an L3 Loop "Out" Conformation for LasR.

Chemical strategies to block quorum sensing (QS) could provide a route to attenuate virulence in bacterial pathogens. Considerable research has focused on this approach in Pseudomonas aeruginosa, which uses the LuxR-type receptor LasR to regulate much of its QS network. Non-native ligands that antagonize LasR have been developed, yet we have little understanding of the mode by which these compounds interact with LasR and alter its function, as the receptor is unstable in their presence. Herein, we report an approach to circumvent this challenge through the study of a series of synthetic LasR agonists with varying levels of potency. Structural investigations of these ligands with the LasR ligand-binding domain reveal that certain agonists can enforce a conformation that deviates from that observed for other, often more potent agonists. These results, when combined with cell-based and biophysical analyses, suggest a functional model for LasR that could guide future ligand design.

Ex vivo normothermic porcine pancreas: A physiological model for preservation and transplant study.

INTRODUCTION: An ex vivo normothermic porcine pancreas perfusion (ENPPP) model was established to investigate effects of machine perfusion pressures on graft preservation. METHODOLOGY: Nine porcine pancreata were perfused with autologous blood at 50 mmHg (control) pressure. Graft viability was compared against four ex-vivo porcine pancreata perfused at 20 mmHg ('low') pressure. Arterio-venous oxygen gas differentials, biochemistry, and graft insulin responses to glucose stimulation were compared. Immunohistochemistry stains compared the cellular viability. RESULTS: Control pancreata were perfused for a median of 3 h (range 2-4 h) with a mean pressure 50 mmHg and graft flow 141 mL min-1. In comparison, all of the 'low' pressure models were perfused for 4 h, with mean perfusion pressure 20 mmHg and graft flow 40 mL.min-1. All pancreata demonstrated cellular viability with evidence of oxygen consumption with preserved endocrine and exocrine function. However, following statistical analysis, the 'low' pressure perfusion of porcine pancreata compared favourably in important biochemical and immunohistochemistry cellular profiles; potentially arguing for an improved method for graft preservation. CONCLUSION: ENPPP will facilitate whole organ preservation to be studied in further detail and avoids use of expensive live animals. ENPPP is reproducible and mimics a "donation after circulatory death" scenario.

Clinical risk scores in the current era of neoadjuvant chemotherapy for colorectal liver metastases.

BACKGROUND: Clinical risk scores (CRS) within the context of neoadjuvant chemotherapy for colorectal liver metastases (CRLM) has not been validated. The predictive value of clinical risk scoring in patients administered neoadjuvant chemotherapy prior to liver surgery for CRLM is evaluated. METHODS: A prospective database over a 15-year period (April 1999 to March 2014) was analysed. We identified two groups: A, neoadjuvant chemotherapy prior to CRLM surgery; and B, no neoadjuvant chemotherapy. RESULTS: Overall median survival in groups A and B were 36 (2-137) months and 33 (2-137) months. In group A, nodal status, size, number of metastases and carcinoembryonic antigen levels were not found to be independent predictors of overall survival (OS). However, patients with a shorter disease-free interval of less than 12 months had an increased OS (P = 0.0001). Multivariate analysis of high- and low-risk scores compared against survival in group B (P < 0.05) confirms the applicability of the scoring system in traditional settings. CONCLUSION: Traditional CRS are not a prognostic predictive tool when applied to patients receiving neoadjuvant chemotherapy for CRLM. Disease-free interval may be one independent variable for use in future risk score systems specifically developed for the neoadjuvant chemotherapy era.

Ex Vivo Porcine Organ Perfusion Models as a Suitable Platform for Translational Transplant Research.

In transplantation surgery, extending the criteria for organ donation to include organs that may have otherwise been previously discarded has provided the impetus to improve organ preservation. The traditional method of cold static storage (CS) has been tried and tested and is suitable for organs meeting standard criteria donation. Ex vivo machine perfusion is, however, associated with evidence suggesting that it may be better than CS alone and may allow for organ donation criteria to be extended. Much of our knowledge of organ preservation is derived from animal studies. We review ex vivo porcine organ perfusion models and discuss the relevance to the field of transplantation surgery. Following a systematic literature search, only articles that reported on experimental studies with focus on any aspect(s) of ex vivo and porcine perfusion of organs yet limited to the context of organ transplantation surgery were included. The database search and inclusion/exclusion criteria identified 22 journal articles. All 22 articles discussed ex vivo porcine organ perfusion within the context of transplant preservation surgery: 8 liver, 3 kidney, 3 lung, 2 pancreas/islet, 4 discussed a combined liver-kidney multiorgan model, 1 small bowel, and 1 cardiac perfusion model systems. The ex vivo porcine perfusion model is a suitable, reliable, and safe translational research model. It has advantages to investigate organ preservation techniques in a reproducible fashion in order to improve our understanding and has implications to extend the criteria for organ donation.

A Study of Normothermic Hemoperfusion of the Porcine Pancreas and Kidney.

Normothermic machine perfusion has enormous potential to improve organ preservation and expand the organ donor pool. It is well established in other organs but not the pancreas, which has especially strict organ acceptance criteria. We established a model of normothermic hemoperfusion of the porcine pancreas with and without addition of the kidney as a dialysis organ. Four pancreases were harvested and perfused for 120 min with autologous whole blood at body temperature, two with parallel perfusion of the kidney and two without. The organs and perfusion circuit were evaluated for gross appearance, pH, histology and perfusion parameters. The organs maintained steadily increasing flow rate and perfusion pressure. Gross appearance of the organs was stable but appeared grossly ischemic toward the end of the perfusion period. Histology demonstrated necrosis centered in acinar tissue but islet cells were preserved. pH was significantly alkalotic toward the end of the perfusion, likely due to pancreatic tissue damage. Addition of the kidney did not result in significant improvement of the acid-base environment in this small series. In conclusion, normothermic perfusion of the pancreas is still in the experimental stages but holds great potential. Further studies to optimize perfusion parameters will significantly improve results. Parallel perfusion of the kidney may facilitate improvement in the acid-base environment.

Current principles and practice in autologous intraportal islet transplantation: a meta-analysis of the technical considerations.

OBJECTIVES: Autologous islet transplantation (IAT) following pancreatectomy is now a recognized, albeit highly specialized procedure carried out in a small number of centers worldwide. Current clinical principles and best practice with emphasis on examining the technical aspects of surgery in centers with significant IAT experience are reviewed. METHODS: Literature search for studies discussing any technical aspect of pancreatectomy with intraportal IAT was included. RESULTS: Thirty-five papers were included; all were single-center case series. The indications, surgical approach to pancreatectomy with IAT, islet yield, static pancreas preservation prior to islet digestion, portal vein access, absolute islet infusion volumes, and portal venous pressure changes during transfusion evaluated. CONCLUSIONS: IAT is considered a "last resort" when alternative approaches have been exhausted. Pre-morbid histology and prior surgical drainage adversely influence islet yields and may influence the clinical decision to perform pancreatectomy and IAT. Following pancreas digestion, absolute numbers of islets recovered and smaller islet size predict rates of insulin independence following IAT. Islet volumes and portal venous pressure changes are important factors for the development of complications. Surgical access for IAT includes intra-operative, immediate or delayed infusion via an "exteriorized" vein, and radiological percutaneous approaches. Delayed infusion can be combined with pancreas preservation techniques prior to islet isolation.

Extracorporeal machine perfusion of the pancreas: technical aspects and its clinical implications--a systematic review of experimental models.

Pancreas or pancreatic islet transplantation is an important treatment option for insulin-dependent diabetes and its complications. However, as the pancreas is particularly susceptible to ischaemic-reperfusion injury, the criteria for pancreas and islet donation are especially strict. With a chronic shortage of donors, one critical challenge is to maximise organ availability and expand the donor pool. To achieve that, continuous improvement in organ preservation is required, with the aims of reducing ischaemia-reperfusion injury, prolong preservation time and improve graft function. Static cold storage, the only method used in clinical pancreas and islet cell transplant currently, has likely reached its plateau. Machine perfusion, hypothermic or normothermic, could hold the key to improving donor pancreas quality as well as quantity available for transplant. This article reviews the literature on experimental models of pancreas machine perfusion, examines the benefits of machine perfusion, the technical aspects and their clinical implications.