Clinical Research Directory

Liver Fibrosis in HIV-Infected Patients With Elevated Liver Enzymes on Antiretroviral Therapy

This study will provide a basis for research on the impact of liver injury caused by antiretroviral therapy in HIV-infected patients. Elevated liver enzymes called AST and ALT are common in HIV-infected patients taking antiretroviral medications and can indicate liver damage. Although there are a number of possible causes for these elevations, such as infections with a hepatitis virus, antiretroviral medications alone can lead to the elevations. The study will focus particularly on evidence of liver fibrosis, which is a sign of progressive liver damage. HIV-infected patients 18 and older who 1) have been taking combination antiretroviral therapy for at least 12 months and have been on a stable regimen for at least 3 months, and 2) have had elevated AST or ALT levels for at least 6 months may be eligible for this study. Patients who have had liver biopsies performed in the past may be eligible for participation. Participants undergo the following tests and procedures over a 12-month period: * Oral glucose tolerance test: The patient drinks a glucose (sugar) drink. Blood samples are then drawn over 2 hours through an intravenous (IV) line in the patient's arm. This test measures how high the patient's blood sugar and insulin levels rise after drinking a standard glucose load. * Transient elastography: This ultrasound test uses vibration (sound waves) to measure liver stiffness (fibrosis). Vibrations move faster through a fibrotic liver. * Triple-phase CT scan and single slice CT scan of L4-5: Patients fast for 4 hours before the CT scan. A contrast material is injected through a catheter placed in an arm vein to improve the visibility of the liver in the specialized X-ray images obtained in the CT scanner. * Liver biopsy: This test removes a small sample of liver tissue for microscopic examination, particularly for evidence of fibrosis. The skin over the biopsy site is numbed and a needle is passed through the skin and rapidly in and out of the liver. Patients may be given a sedative for the procedure. * Follow-up visits. Patients return for follow-up visits 1 to 4 weeks after the liver biopsy and three more times over the course of the study for a medical history, physical examination and blood tests. Patients may participate in an additional 4-year follow-up, during which they have visits every 3-12 months and are offered the opportunity to repeat the biopsy no sooner than 1 year after the first biopsy. ...

LIVERAGE™: A Study to Test Whether Survodutide Helps People With a Liver Disease Called NASH/MASH Who Have Moderate or Advanced Liver Fibrosis

This study is open to adults who are at least 18 years old living with obesity and have: * a confirmed liver disease called non-alcoholic steatohepatitis (NASH)/metabolic associated steatohepatitis (MASH) and * moderate or advanced liver fibrosis People with a history of acute or chronic liver diseases other than MASH or chronic alcohol intake cannot take part in this study. The purpose of this study is to find out whether a medicine called survodutide helps people with MASH and moderate or advanced liver fibrosis improve their liver function. This study has 2 parts. The purpose of the first part of this study is to find out the effect of survodutide on MASH and liver fibrosis. The purpose of the second part is to find out how safe and effective survodutide is in improving liver function. Participants are put into 2 groups randomly, which means by chance. 1 group gets survodutide and 1 group gets placebo. Placebo looks like survodutide but does not contain any medicine. Each participant has twice the chance of getting survodutide. Participants and doctors do not know who is in which group. Participants inject survodutide or placebo under their skin once a week. The survodutide doses are slowly increased until the target dose is reached. All participants receive counselling to make changes to their diet and to exercise regularly. Participants are in the study for up to 7 years. During this time, they regularly visit the study site or have remote visits by video call. For about the first year of the study, participants have these visits every 2 weeks, increasing to every 4 weeks and then every 6 weeks. After being in the study for a little over a year participants will then alternate between visiting the study site or having a remote visit every 3 months until the end of the study. The doctors check participants' health and take note of any unwanted effects. The participants' body weight and effects on the stomach and intestines are regularly measured. At some visits the liver is measured using different imaging methods. At 2 or 3 visits doctors take a small sample of liver tissue (biopsy). The participants also fill in questionnaires about their symptoms and quality of life. The results are compared between the groups to see whether the treatment works.

Study of Hydroxynidone Capsules in Patients With Hepatic Impairment and Matched Healthy Controls

This trial adopts a single-center, single-dose, open-label, non-randomized, parallel-controlled design. It will be conducted in participants with varying degrees of hepatic impairment, as well as in participants with normal hepatic function matched for sex, age, and BMI. The administration method is a single oral dose of 90 mg hydroxynidone capsules under fasting conditions. Participants meeting the inclusion criteria with corresponding degrees of hepatic impairment and those with normal hepatic function will be enrolled. Each group will complete the study with 10 participants. Matched participants will be comparable in terms of sex (±1 participant per sex), mean age (±10 years), and mean BMI (±10%).

Isocaloric Navy-Bean Substitution in Adults With MASLD

This study is a 24-week randomized crossover feasibility trial evaluating an isocaloric navy-bean dietary substitution in 40 adults with metabolic dysfunction-associated steatotic liver disease (MASLD) and intermediate-stage (F2-F3) fibrosis. Participants are randomized to one of two sequences-habitual diet followed by a navy-bean-rich diet, or a navy-bean-rich diet followed by habitual diet-with each 12-week phase guided by registered dietitians so that navy beans replace an equivalent caloric load without changing total energy intake. The primary aim is to establish feasibility and acceptability, measured by recruitment and retention, adherence with biomarker (plasma pipecolic-acid) concordance, and patient acceptability.

Different Treatment Frequencies for Hepatic Fibrosis Due to Schistosomiasis

The goal of this clinical trial is to learn if treating individuals living in Uganda who have liver fibrosis (scarring) due to schistosomiasis would benefit from more frequent treatment with drug praziquantel. This drug is already approved to treat schistosomiasis and is used globally. The study will include individuals who have schistosomiasis and some degree of liver fibrosis. The main questions it aims to answer are: 1. Does treating participants three times per year as compared to once per year as currently recommended improve the likelihood the hepatic fibrosis will improve over three years. 2. Does treating participants three times per year as compared to once per year as currently recommended decrease the risk they have for bleeding due to portal hypertension over three years. 3. Is there a blood test that can tell us which individuals will experience worsening liver fibrosis before this happens. Participants will: Be screened for schistosomiasis using a urine test If participants have schistosomiasis they will undergo other screening procedures including a liver ultrasound, blood tests, and a physical exam if they have both schistosomiasis and liver (fibrosis) they will be invited to participate in the trial If they are in the trial they will: Take the drug praziquantel once per year or three times per year based on randomization for three years Have a liver ultrasound and blood samples for markers of liver fibrosis once per year Provide a urine sample to test for schistosomiasis each year

Remedial Mechanism of Simvastatin and Ursodeoxycholic Acid in Liver Cirrhosis: Crosstalk of Bile Secretion, Gut Microbiome, and Host Immune Response

This exploratory, randomized, open-label pilot study evaluated gut microbiota, fecal bile acid profiles, inflammatory markers, and fibrosis-related biomarkers in adults with chronic hepatitis B or hepatitis C after viral control. The study included a randomized cohort with advanced liver fibrosis and a non-randomized comparison cohort without advanced fibrosis. Viral control was defined as hepatitis B virus suppression during antiviral therapy or sustained virologic response after hepatitis C treatment. The main questions addressed by the study were: Do participants with advanced liver fibrosis differ from those without advanced fibrosis in their baseline gut microbiota, fecal bile acid profiles, inflammatory markers, or fibrosis-related biomarkers? What within-participant changes in these measures are observed after six months of treatment with ursodeoxycholic acid (UDCA), simvastatin, or combined UDCA plus simvastatin? What descriptive patterns of change are observed across the three active-treatment groups? Advanced liver fibrosis was operationally defined during enrollment as a FibroScan liver stiffness measurement of ≥9.5 kPa. Thirteen participants with presumed advanced liver fibrosis were randomized to observation without study medication, UDCA alone, simvastatin alone, or combined simvastatin plus UDCA. One randomized participant was subsequently excluded from the analysis after eligibility review because the advanced-fibrosis criteria were not confirmed, leaving 12 eligible randomized participants, with three participants in each study group. An additional six participants with non-advanced fibrosis, defined by a FibroScan liver stiffness measurement of \<6.0 kPa, were enrolled as a non-randomized baseline comparison group. Baseline blood and stool samples were collected from all 19 enrolled participants. The final baseline analysis set included 18 eligible participants: 12 participants with advanced fibrosis and six participants without advanced fibrosis. Follow-up blood and stool samples were collected after six months from the nine participants in the three active-treatment groups. The observation group and the non-advanced fibrosis comparison group contributed baseline data only and did not undergo post-treatment sampling. Recruitment was substantially slower than anticipated and was discontinued after the available study funding was exhausted. The study was therefore terminated before reaching its originally planned enrollment target. The final actual enrollment was 19 participants, of whom 18 were included in the final analysis set. Because only three participants were available in each randomized study group, all treatment-related analyses were considered exploratory and hypothesis-generating. The study was not designed or adequately powered to establish clinical efficacy, histological fibrosis regression, or superiority of combination therapy.

Fibrosis Lessens After Metabolic Surgery

Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as non-alcoholic fatty liver disease (NAFLD), a major global public health concern, is commonly associated with obesity, diabetes, and dyslipidemia. MASLD is currently the most common cause of chronic liver disease affecting about 80% of people with obesity, ranging from simple fat deposits in the liver to Metabolic Dysfunction-Associated Steatohepatitis (MASH), cellular injury, advanced fibrosis, cirrhosis, or hepatocellular carcinoma. Patients with MASH are also at risk for cardiovascular disease and mortality. There is no universally approved medication for MASH. Weight loss remains the cornerstone of MASH treatment. Patients meeting the inclusion and exclusion criteria and who give informed consent will be enrolled in the trial and undergo the baseline liver biopsy (if none available). Approximately 120 patients with MASH and liver fibrosis (F1-F4 in baseline liver biopsy) will be randomized in a 1:1 ratio to metabolic surgery or medical treatment (incretin-based therapies ± other medical therapies for MASH) and followed for 2 years at which time a repeat liver biopsy will be performed for the assessment of the primary end point.

Study of AZD2389 Safety, Tolerability, and Pharmacodynamics in Adults With Steatotic Liver Disease and Advanced Fibrosis

The purpose of this study is to evaluate the safety, tolerability, and pharmacodynamic effects of AZD2389 in adult participants with steatotic liver disease (SLD) and advanced fibrosis.

The Phase 1, Open-label, PET Trial Designed to Investigate the Effect of AZD2389 on FAP Occupancy in the Liver in Participants With Advanced Liver Fibrosis.

This is a phase 1, open-label, PET trial. The study is designed to investigate the effect of AZD2389 on FAP occupancy in the liver in participants with advanced liver fibrosis.

Wearable Patch Ultrasound Probe for Diagnosis of Liver Stiffness

Liver stiffness measurement is a key non-invasive tool for assessing liver fibrosis and cirrhosis in patients with chronic liver disease. Transient elastography (FibroScan) is currently the most widely used non-invasive reference standard, but it requires a dedicated device and trained operator, which may limit its accessibility in some clinical settings. This study aims to evaluate the diagnostic accuracy of a novel wearable patch-type ultrasound probe for detecting significant liver fibrosis and cirrhosis, using FibroScan as the reference standard. Patients with chronic liver disease will undergo simultaneous liver stiffness measurement using both the wearable patch ultrasound probe and FibroScan. The diagnostic performance of the patch probe, including sensitivity, specificity, and area under the receiver operating characteristic curve (AUC), will be evaluated against fibrosis staging determined by FibroScan, along with the correlation and agreement between the two measurement methods.

Screening in Primary Care of Advanced Liver Fibrosis in NAFLD and/or Alcoholic Patients

The primary objective of the SOPRANO study is to compare two blood fibrosis tests, the eLIFT and the FibroMeter, for the screening of advanced liver fibrosis in patients with NAFLD and/or ALD from primary care centers.

Effect of Endoscopic Sleeve Gastroplasty in Patients With Obesity and MASH: A Randomized Controlled Trial

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common chronic liver disease globally. While weight loss through lifestyle modification is the standard treatment, most patients regain weight limiting ultimate improvement in liver disease. On the other end of the spectrum, bariatric surgery has shown promise in the treatment of MASLD/metabolic dysfunction-associated steatohepatitis (MASH) due to its efficacy in inducing weight loss. Nevertheless, its adoption has been hindered by the perceived invasiveness of surgery. Over the past decade, endoscopic sleeve gastroplasty (ESG) has gained recognition as a promising minimally-invasive approach to weight loss. The procedure involves utilizing a Food and Drug Administration (FDA)-authorized endoscopic suturing device to reduce the gastric volume by 70%. Studies reveal that ESG is associated with approximately 18.2% weight loss at one year after the procedure, with sustained results for at least 10 years. Nevertheless, the effect of ESG on MASH remains unknown. In this study, the investigators will compare ESG + lifestyle modification versus lifestyle modification alone in treating histologic MASH. The study will randomize patients to one of two different treatment options: ESG + lifestyle modification or lifestyle modification alone.

Automated Passive Case-Finding for Advanced Liver Fibrosis in MASLD: The LiverSeek Programme

LiverSeek is a fully automated, passive case-finding programme for advanced liver fibrosis associated with metabolic dysfunction-associated steatotic liver disease (MASLD) in primary care. The programme operates through the Laboratory Information System (LIS; Modulab/Biwer Analytics) of the Clinical Biochemistry Laboratory at Hospital General Universitario Gregorio Marañón (HGUGM), covering approximately 350,000 inhabitants across 11 peri-urban primary care centres affiliated to SERMAS (Servicio Madrileño de Salud) in Madrid, Spain. When a high-risk patient (age 50-75 years with ≥1 of: ALT above ULN + HbA1c ≥6.5%; ALT above ULN + BMI \>30; BMI \>30 + HbA1c ≥6.5%) undergoes a routine blood test in primary care, the LIS automatically calculates FIB-4. If FIB-4 \>1.30, the system reflexively orders ELF and MASEF from the same serum sample, without any action required from the primary care clinician. Patients with a positive second-step NIT (ELF ≥9.8 or MASEF ≥0.33) receive an automatic alert directing them to the Hepatology Advanced Practice Nurse for VCTE (FibroScan) and clinical evaluation. The primary objective is to evaluate the prevalence of hepatic fibrosis in the high-risk population using this single-step automated strategy. Secondary objectives include head-to-head diagnostic comparison of FIB-4+ELF vs FIB-4+MASEF vs FIB-4+FAST for histologically-confirmed endpoints (significant fibrosis ≥F2, advanced fibrosis ≥F3, at-risk MASH), evaluation of the Liver Risk Score, and a health-economic analysis. A sub-study evaluates a nurse-led structured lifestyle intervention in NIT-positive patients.

Patients With Primary Biliary Cholangitis(PBC)

Primary Biliary Cholangitis (PBC) is a chronic autoimmune cholestatic liver disease characterized by the progressive destruction of small intrahepatic bile ducts, leading to chronic cholestasis, hepatic fibrosis, and, in advanced stages, cirrhosis. Recent advances in the understanding of PBC pathophysiology have highlighted the central role of immune, inflammatory, and metabolic alterations in disease onset and progression.

Incidence of Liver Disease-Related Outcomes in People With HIV

Antiretroviral therapy can effectively control the replication of HIV, prolong the lifespan of patients infected with HIV, and improve their quality of life.At the same time, non-AIDS-related diseases such as diabetes and chronic liver diseases are increasing day by day.Metabolic associated fatty liver disease (MAFLD) is a chronic progressive liver disease caused by overnutrition and insulin resistance in genetically susceptible individuals. It was formerly known as non-alcoholic fatty liver disease (NAFLD).With the continuous improvement of living standards and the constant change of lifestyles, the incidence of metabolic associated fatty liver disease is gradually increasing. Metabolic associated steatohepatitis (MASH) may further develop into liver cirrhosis, liver failure and hepatocellular carcinoma, and is the third most common cause of liver transplantation. In HIV patients, early identification of significant liver fibrosis and MASH with fibrosis is of vital importance.However, due to the fact that the pathogenesis of liver fibrosis in HIV patients is more complex than that in the general population, it involves multiple factors such as the virus, reverse transcriptase drugs, chronic inflammation, and immune disorders.However, the current clinical research on metabolic-related fatty liver fibrosis in people with HIV is still rather limited.

Interventional AI-Human Collaboration for Steatotic Liver Disease Screening

Steatotic liver disease (SLD) is one of the most prevalent chronic liver diseases worldwide, affecting nearly 30% of the global population and projected to exceed 55% by 2040. Timely identification and management of intermediate- and high-risk SLD patients are essential, yet early detection remains challenging because current diagnostic modalities, such as biopsy, ultrasonography, and serum indices, are invasive, insensitive, operator-dependent, or difficult to scale. In contrast, non-contrast CT is widely available in routine care and offers substantial potential for opportunistic SLD screening, although this value has not been fully utilized. Our previously developed MAOSS model accurately identifies intermediate- and high-risk individuals, with MAOSS score≥1.6 combined with Fibro Score ≥1.7, demonstrating high sensitivity and specificity in our large-scale retrospective study. However, despite these promising retrospective findings, the model has not undergone prospective interventional validation, and it remains unclear whether an AI-guided workflow can truly enhance clinical risk stratification, diagnostic yield, and downstream management in real-world SLD populations. Therefore, a prospective intervention study is needed to determine whether MAOSS-guided identification and recall of at-risk individuals can meaningfully improve fibrosis detection and optimize clinical care pathways for SLD.

Sonazoid CEUS for Early HCC Surveillance

This study is a multicenter, prospective study. In this study, enrolled subjects are cirrhotic patients of any etiology. The US and Sonazoid CEUS monitoring strategy was performed for cirrhotic patients: US and AFP joint with Sonazoid CEUS every 4 to 6 months, and combined CECT/CEMRI every 12 months.

Effect of an Early Time Restricted Eating Mediterranean Diet Compared to Naltrexone/Bupropion on Liver Fibrosis in People With Cardiometabolic Risk Factors in a Hospital Outpatient Clinic (MEDFAST-study)

In the Netherlands, there are many people with cardiometabolic diseases. More than half of these people also have fatty liver. This is a build-up of fat in the liver (steatosis) and can lead to long-term scarring (fibrosis) and even death of the liver. Losing weight can help reduce this. Losing weight can be done with medication such as naltrexone/bupropion, which is often prescribed to people with cardiometabolic diseases, but losing weight can also be done with diet. In this study, the investigators want to combine a Mediterranean diet (with lots of vegetables, fruits, whole grain products, nuts and olive oil) with intermittent fasting. In addition participants are not allowed to eat after the evening meal. The investigators will compare this with a group of participants receiving naltrexone/bupropion, to see if a diet with intermittent fasting might be better for reducing liver steatosis and fibrosis in people with cardiometabolic diseases.

Samsung S-Viscosity vs Canon Dispersion Slope in Steatotic Liver Disease (SAVID-SLD)

Steatotic liver disease (SLD) is one of the most common chronic liver diseases worldwide. Distinguishing simple steatosis from metabolic dysfunction-associated steatohepatitis (MASH) with significant fibrosis is clinically important, but liver biopsy - the current standard - is invasive. Recent ultrasound technology allows noninvasive measurement of tissue viscoelasticity, which has been linked to liver inflammation. Samsung Medison's HERA W12 system (S-Viscosity) and Canon Aplio i800 (Dispersion Slope Imaging) both provide vendor-specific viscoelasticity parameters derived from shear-wave dispersion analysis, but their relationship and agreement have not been compared in SLD patients. This prospective single-center observational study will enroll approximately 95-100 participants in three cohorts: (A) 15-20 living-donor candidates as a healthy reference, (B+C) approximately 80 adults with sonographically suspected or confirmed SLD recruited consecutively. SLD participants will be classified post-hoc into low-MASH-risk (Cohort B) and at-risk MASH (Cohort C) subgroups using a multi-parametric stratification combining liver stiffness (LSM), DeepUSFF (deep-learning-based ultrasound fat fraction), and serum AST. All participants will undergo same-day ultrasound examination with both Samsung HERA W12 and Canon Aplio i800. The primary objective is to evaluate the correlation and agreement between Samsung S-Viscosity and Canon Dispersion Slope. Secondary objectives include deriving a normal reference range from the healthy cohort, comparing viscoelasticity parameters across cohorts, and exploring a Modified US-FAST score.

Dasatinib and Quercetin to Treat Fibrotic Non-alcoholic Fatty Liver Disease

To examine the effect of dasatinib plus quercetin on liver fibrosis in individuals with biopsy proven NAFLD with fibrosis by performing a double-blind randomized controlled proof-of-principle study

Single-cell Multiomics and Spatiotemporal Omics Analyze the Mechanism of Liver Degenerative Disease

The purpose of this observational study is to employ single-cell multi-omics and spatial omics technologies to characterize the spatial and immune structures within the livers of patients with fatty liver, hepatic hemangioma, focal nodular hyperplasia, liver fibrosis, cirrhosis, and HBV infection. The primary questions it aims to address are: Investigate the mechanisms of liver degenerative changes during the processes of liver aging, fatty liver, HBV infection, liver fibrosis, and cirrhosis. Characterize the molecular features and cellular networks at different stages of liver degeneration and identify new targets and mechanisms for the cure of the aforementioned diseases. The study will collect peripheral blood and discarded liver tissue from patients with hepatic hemangioma, fatty liver, HBV infection, liver fibrosis, and cirrhosis who are undergoing hepatectomy or liver biopsy.

The Correlation Between hs CRP TG Triglycerides Glucose Index in NAFLD and Liver Fibrosis

The Correlation between hs CRP TG triglycerides Glucose index in NAFLD and liver fibrosis

Prevalence and Risk Factors of Metabolic-Associated Hepatic Steatosis in Individuals Living With Type 1 Diabetes

The goal of this observational cross-sectional study is to assess the prevalence and stage of Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD), specifically liver steatosis and fibrosis in adults aged 18 and older living with type 1 diabetes or Latent Autoimmune Diabetes in Adults (LADA) in Quebec. The main questions it aims to answer are: 1. What is the prevalence and severity of liver steatosis and fibrosis among people living with type 1 diabetes in Québec? 2. Are there patients with type 1 diabetes who have advanced, undiagnosed stages of liver disease that require management but are missed by current standard care practices? Researchers will compare three participant subgroups based on adiposity (a control group without increased adiposity, an overweight group with increased adiposity, and an obesity group with increased adiposity) to see if the prevalence and severity of hepatic steatosis and fibrosis are highest in the obesity group and lowest in the control group. They will also explore if variables and potential risk factors associated with liver disease differ across these subgroups. Participants will attend a single study visit where they will be asked to: * Provide clinical data through laboratory analyses. * Undergo specific clinical procedures. * Complete validated questionnaires.

Rapid Breath-hold Quantitative Macromolecular Proton Fraction Imaging for Liver Fibrosis

Chronic liver disease is a major health problem worldwide. Liver fibrosis is a key feature in most chronic liver diseases. When identified early, liver fibrosis may be reversible. Currently, liver biopsy is the gold standard for the diagnosis of liver fibrosis. Liver biopsy; however, is invasive. Non-invasive diagnostic tools are increasingly used in clinical practice. However, the existing noninvasive methods still have significant limitations to detect early-stage liver fibrosis. Liver fibrosis is characterized by excessive deposition of collagen-rich connective tissues in the liver. The macromolecular proton fraction (MPF) is an MRI parameter which characterizes the magnetization transfer (MT) effect in tissues. Quantitative MPF imaging is non-invasive and can be used to measure collagen deposition in the liver due to the strong MT effect of collagen. It has been reported MPF quantification can be used for diagnosis of early-stage liver fibrosis. However, the existing approaches require B1, B0, and T1 map in addition to the imaging data for MPF quantification, which makes it challenging to adopt them for routine clinical use. The investigators propose a fast and robust MPF quantification approach. In contrast to the existing methods which rely on saturation radiofrequency pulses for MPF quantification, our approach is based on spin-lock radiofrequency pulses which have minimum Rabi oscillations. The whole imaging data can be acquired within a breath-hold less than 8 seconds. Our approach only needs a B1 map in addition to the imaging data for MPF quantification. The preliminary clinical studies on 3.0T MRI show the measurement using our approach is specific to collagen content and can be used to detect early-stage liver fibrosis. To further confirm the clinical value of the proposed approach, the investigators will investigate the relationship of the collagen content measured using the proposed non-invasive imaging approach and those measured based on morphometry analysis of histology, and determine the diagnostic value of the proposed method for detection of early stage liver fibrosis in a large cohort. The investigators will also perform comparative studies of the proposed method and the state-of-the-art quantitative MPF imaging technique. This project will provide a diagnostic technology for early detection of liver fibrosis. The proposed MRI technology also has potential to be used for other clinical purposes.