Renal Protection with SGLT2 Inhibitors: Effects in Acute and Chronic Kidney Disease.

PURPOSE OF REVIEW: This review offers a critical narrative evaluation of emerging evidence that sodium-glucose co-transporter-2 (SGLT2) inhibitors exert nephroprotective effects in people with type 2 diabetes. RECENT FINDINGS: The SGLT2 inhibitor class of glucose-lowering agents has recently shown beneficial effects to reduce the onset and progression of renal complications in people with and without diabetes. Randomised clinical trials and 'real world' observational studies, mostly involving type 2 diabetes patients, have noted that use of an SGLT2 inhibitor can slow the decline in glomerular filtration rate (GFR), reduce the onset of microalbuminuria and slow or reverse the progression of proteinuria. The nephroprotective effects of SGLT2 inhibitors are class effects observed with each of the approved agents in people with a normal or impaired GFR. These effects are also observed in non-diabetic, lean and normotensive individuals suggesting that the mechanisms extend beyond the glucose-lowering, weight-lowering and blood pressure-lowering effects that accompany their glucosuric action in diabetes patients. A key mechanism is tubuloglomerular feedback in which SGLT2 inhibitors cause more sodium to pass along the nephron: the sodium is sensed by macula cells which act via adenosine to constrict afferent glomerular arterioles, thereby protecting glomeruli by reducing intraglomerular pressure. Other effects of SGLT2 inhibitors improve tubular oxygenation and metabolism and reduce renal inflammation and fibrosis. SGLT2 inhibitors have not increased the risk of urinary tract infections or the risk of acute kidney injury. However, introduction of an SGLT2 inhibitor in patients with a very low GFR is not encouraged due to an initial dip in GFR, and it is prudent to discontinue therapy if there is an acute renal event, hypovolaemia or hypotension.

Treatment of type 2 diabetes: future approaches.

Introduction or background: Type 2 diabetes, which accounts for ~90% of all diabetes, is a heterogeneous and progressive disease with a variety of causative and potentiating factors. The hyperglycaemia of type 2 diabetes is often inadequately controlled, hence the need for a wider selection of glucose-lowering treatments. Sources of data: Medline, PubMed, Web of Science and Google Scholar. Areas of agreement: Early, effective and sustained control of blood glucose defers the onset and reduces the severity of microvascular and neuropathic complications of type 2 diabetes and helps to reduce the risk of cardiovascular (CV) complications. Areas of controversy: Newer glucose-lowering agents require extensive long-term studies to confirm CV safety. The positioning of newer agents within therapeutic algorithms varies. Growing points: In addition to their glucose-lowering efficacy, some new glucose-lowering agents may act independently to reduce CV and renal complications. Areas timely for developing research: Studies of potential new glucose-lowering agents offer the opportunity to safely improve glycaemic control with prolonged efficacy and greater opportunity for therapeutic individualisation.

Viral adaptation to host immune responses occurs in chronic hepatitis B virus (HBV) infection, and adaptation is greatest in HBV e antigen-negative disease.

Hepatitis B virus (HBV)-specific T-cell responses are important in the natural history of HBV infection. The number of known HBV-specific T-cell epitopes is limited, and it is not clear whether viral evolution occurs in chronic HBV infection. We aimed to identify novel HBV T-cell epitopes by examining the relationship between HBV sequence variation and the human leukocyte antigen (HLA) type in a large prospective clinic-based cohort of Asian patients with chronic HBV infection recruited in Australia and China (n = 119). High-resolution 4-digit HLA class I and II typing and full-length HBV sequencing were undertaken for treatment-naïve individuals (52% with genotype B, 48% with genotype C, 63% HBV e antigen [HBeAg] positive). Statistically significant associations between HLA types and HBV sequence variation were identified (n = 49) at 41 sites in the HBV genome. Using prediction programs, we determined scores for binding between peptides containing these polymorphisms and associated HLA types. Among the regions that could be tested, HLA binding was predicted for 14/18 (78%). We identified several HLA-associated polymorphisms involving likely known anchor residues that resulted in altered predicted binding scores. Some HLA-associated polymorphisms fell within known T-cell epitopes with matching HLA restriction. Enhanced viral adaptation (defined as the presence of the relevant HLA and the escaped amino acid) was independently associated with HBeAg-negative disease (P = 0.003). Thus, HBV appears to be under immune pressure in chronic HBV infection, particularly in HBeAg-negative disease.

A nurse-led, telehealth-driven hepatitis C management initiative in regional Victoria: Cascade of care from referral to cure.

INTRODUCTION: Elimination of hepatitis C virus stands as an unresolved World Health Organization target, and is associated with complications including cirrhosis and hepatocellular carcinoma. Hepatitis C virus management has been revolutionised following the widespread availability of direct-acting antiviral agents in Australia since 2016; however, large proportions of the population remain untreated. Telehealth-based service delivery is an accessible and effective alternative, and we aimed to assess qualitative and clinical outcomes in a clinical nurse consultant-led regional telehealth model. METHODS: A prospective cohort analysis of all patients referred to a Victorian regional hospital's hepatitis C virus telehealth clinic between 1 April 2017 and 10 June 2020 was conducted. Data were collated from outpatient and electronic medical records. RESULTS: Fifty-five out of 71 referred patients were booked, with 44 patients (80%) attending at least one appointment. A history of alcohol use disorder and psychiatric comorbidity was seen in 25 (54%) and 24 (52%) patients, respectively. Twenty-one out of 24 (88%) eligible patients had direct-acting antiviral agent treatment and 14 out of 21 (67%) successfully completed the treatment. An average of 46.5 km, 54.6 min and $AUD30.70 was saved per patient for each visit. Observed benefits included: increased medical engagement, adherence to and completion of HCV treatment and cirrhosis monitoring. Telehealth-driven hepatocellular carcinoma surveillance was successful in the cirrhotic subgroup. CONCLUSION: Clinical nurse consultant-led hepatitis C virus management via telehealth allows access to marginalised regional populations. Clinical outcomes were comparable to other cohorts with additional cost-benefit, efficiency gains and carbon footprint reduction amongst a previously unreported regional Victorian hepatitis C virus population.

Characterization of the migration of lung and blood T cells in response CXCL12 in a three-dimensional matrix.

The ability of T cells to microlocalize within tissues, such as the lung, is crucial for immune surveillance and increased T-cell infiltration is a feature of many inflammatory lung conditions. T-cell migration has mainly been studied in two-dimensional assays. Using three-dimensional collagen gels to mimic the extracellular matrix of lung tissue, we have characterized the migration of T lymphocytes isolated from peripheral blood (PBT) and lung (LT) in response to interleukin-2 (IL-2) and CXCL12. Freshly isolated PBT and LT showed a low degree of migration (blood 4.0 +/- 1.3% and lung 4.1 +/- 1.7%). Twenty-four hours of culture increased the percentage of migrating PBT and LT (blood 17.5 +/- 2.9% and lung 17.7 +/- 3.8%). The IL-2 stimulation modestly increased migration of PBT after 6 days (32.3 +/- 6.0%), but had no effect on the migration of LT (25.5 +/- 3.2%). Twenty-four hours of stimulation with anti-CD3/CD28 caused a small but significant increase in the migration of PBT (to 36.4 +/- 5.8%). In a directional three-dimensional assay, CXCL12 failed to induce migration of fresh PBT or LT. Twenty-four hours of culture, which increased CXCR4 expression of PBT 3.6-fold, significantly increased the migration of PBT in response to CXCL12. Migration of PBT to CXCL12 was blocked by pertussis toxin, but not by the phosphoinositide 3-kinase inhibitor wortmannin. Twenty-four-hour cultured LT did not respond to CXCL12. CD3/CD28-stimulation inhibited CXCL12-mediated migration of PBT. These results suggest that the migration pattern of PBT is distinct from that of LT.

The chemokine CXCL16 is highly and constitutively expressed by human bronchial epithelial cells.

The chemokine receptor CXCR6 is highly expressed on lung-derived T cells compared to blood T cells, especially in inflammatory diseases characterised by T-cell migration to the lung. This suggests that CXCR6 is a candidate lung homing receptor. The sole ligand of CXCR6, CXCL16, has previously been shown to be expressed by alveolar macrophages. The authors hypothesized that also structural lung cells express CXCL16. CXCL16 expression was detected using real-time reverse transcriptase-polymerase chain reaction (RT-PCR), Western blotting, enzyme-linked immunosorbent assay (ELISA), and flow cytometry. Chemotaxis assays were used to test functionality of the secreted protein. Human bronchial epithelial cells secreted relatively high basal levels of CXCL16 (> 1000 pg/mL). Interferon (IFN)-gamma, but not tumor necrosis factor (TNF)-alpha or interleukin (IL)-4, caused a modest but significant up-regulation in secretion. Airway smooth muscle and fibroblasts also expressed CXCL16, but at lower levels. Western blotting detected expression of the full-length (60-kDa) form of the chemokine in cell lysates, and the cleaved (35-kDa) form in culture supernatants. Concentrated supernatants from a bronchial epithelial cell line (BEAS-2B) were chemotactic for CXCR6 expressing T cells from blood. In conclusion, these results suggest that the bronchial epithelium is an important source of constitutively expressed CXCL16, which may be involved in T-cell recruitment to the lung in health and disease.

The future of new drugs for diabetes management.

The future of the newer classes of glucose-lowering drugs, namely dipeptidyl peptidase-4 (DPP-4) inhibitors, glucagon-like peptide-1 receptor agonists (GLP-1RAs) and sodium/glucose co-transporter-2 (SGLT-2) inhibitors, is being redefined by the large prospective cardiovascular outcome trials (CVOTs). These trials have more than confirmed cardiovascular (CV) safety: indeed, various cardio-renal parameters have improved during some of the trials with GLP-1RAs and SGLT-2 inhibitors in type 2 diabetes. Benefits have included reductions in major adverse cardiovascular events such as fatal and non-fatal myocardial infarction and stroke, decreased hospitalization for heart failure, a slower decline in glomerular filtration rate and reduced onset and progression of albuminuria. In consequence, the CVOTs have raised expectations that newer glucose-lowering agents should offer advantages that extend beyond glycaemic control and weight management to address complications and comorbidities of type 2 diabetes, particularly cardio-renal diseases. Although large prospective outcome trials incur a high cost which may prompt reconsideration of their design, these trials are generating evidence to enable more exacting and more effective management of type 2 diabetes and its accompanying cardio-renal diseases.

Metabolic syndrome, or What you will: definitions and epidemiology.

The metabolic syndrome is a clustering of risk factors which predispose an individual to cardiovascular morbidity and mortality. There is general consensus regarding the main components of the syndrome (glucose intolerance, obesity, raised blood pressure and dyslipidaemia [elevated triglycerides, low levels of high-density lipoprotein cholesterol]) but different definitions require different cut points and have different mandatory inclusion criteria. Although insulin resistance is considered a major pathological influence, only the World Health Organization (WHO) and European Group for the study of Insulin Resistance (EGIR) definitions include it amongst the diagnostic criteria and only the International Diabetes Federation (IDF) definition has waist circumference as a mandatory component. The prevalence of metabolic syndrome within individual cohorts varies with the definition used. Within each definition, the prevalence of metabolic syndrome increases with age and varies with gender and ethnicity. There is a lack of diagnostic concordance between different definitions. Only about 30% of people could be given the diagnosis of metabolic syndrome using most definitions, and about 3540% of people diagnosed with metabolic syndrome are only classified as such using one definition. There is currently debate regarding the validity of the term metabolic syndrome, but the presence of one cardiovascular risk factor should raise suspicion that additional risk factors may also be present and encourage investigation. Individual risk factors should be treated.

Expression of Fas and FasL in human serous ovarian epithelial tumors.

The expression of Fas and FasL was studied in 86 patients with benign, borderline, and malignant serous ovarian lesions. Four normal ovaries, and monolayer epithelial cultures from a human fetal ovary, a borderline, and a serous adenocarcinoma were used for comparison. Expression of Fas and FasL was studied immunohistochemically and flowcytometrically. Fas was expressed in all 90 lesions; FasL in 57 lesions, including 2 normal ovaries. Fas expression was significantly increased in borderline tumors compared with benign (P = 0.005, t = -2.94) or malignant serous tumors (P = 0.0001, t = 4.15). FasL expression was significantly increased in malignant tumors compared with benign (P = 0.039, t = -2.10) and borderline tumors (P = 0.0016, t = -3.33). Flow cytometry showed a range of Fas expression in short-term cultures isolated from normal, borderline, and malignant ovarian serous tissue; in the few samples studied, FasL was not expressed. Expression in three serous ovarian cell lines was similar. Fas and FasL expression differed throughout the spectrum of ovarian lesions. FasL expression was increased in malignant tumors, and Fas expression was increased in borderline tumors. Changes in Fas/FasL expression in ovarian surface epithelium might play a functional role in the biology of ovarian tumors.

Future therapies.

New and improved therapies are required for type 1 and type 2 diabetic patients to assist the return of glucose homeostasis to as near normal as possible. More intensive use of existing therapies is proving beneficial, while potential new agents are progressing in development. These include agents to improve and partially mimic insulin action, such as peroxisome proliferator-activated receptor-gamma (PPARgamma) agonists, stimulants of intracellular insulin signalling intermediates, and inhibitors of substances that deactivate insulin receptor tyrosine kinase activity. Novel agents to enhance nutrient-stimulated insulin release and promote the replication and neogenesis of beta-cells are emerging, along with new agents to combat obesity and dyslipidaemia. Gene therapy approaches to replace defective or destroyed beta-cells are feasible future options for both type 1 and type 2 diabetes.

Clinical and diagnostic significance of blood in cervical smears.

A heavy admixture of blood in cervical smears can be problematic for the screener, as the presence of blood can influence the staining quality of the cancer cell nuclei. However, it might also be a blessing in disguise. A retrospective study of 40 clinically important smears, 34 originally signed out as negative for squamous cell carcinoma of the cervix and 6 smears as unsatisfactory, was carried out in comparison with 100 smears from healthy women. Sample parameters were analyzed by macroscopy and neural network scanning. Differences between the two study groups were measured by Pearson's chi(2) test. Of the 40 study cases, one case featured insufficient material, while 16 cases (40%) could confidently be classified as malignant or negative for malignancy. The most important macroscopic parameter of the smears was an admixture of blood. This background feature was also highlighted by the NNS system. Angiogenesis was visualized by the expression of CD34 in many sampled capillary fragments included in the smears. In conclusion, blood in cervical smears may have clinical and diagnostic significance. The rate of "failed smears" in routine cervical screening might thus by CD34 be considerably decreased.

Hippo signaling regulates pancreas development through inactivation of Yap.

The mammalian pancreas is required for normal metabolism, with defects in this vital organ commonly observed in cancer and diabetes. Development must therefore be tightly controlled in order to produce a pancreas of correct size, cell type composition, and physiologic function. Through negative regulation of Yap-dependent proliferation, the Hippo kinase cascade is a critical regulator of organ growth. To investigate the role of Hippo signaling in pancreas biology, we deleted Hippo pathway components in the developing mouse pancreas. Unexpectedly, the pancreas from Hippo-deficient offspring was reduced in size, with defects evident throughout the organ. Increases in the dephosphorylated nuclear form of Yap are apparent throughout the exocrine compartment and correlate with increases in levels of cell proliferation. However, the mutant exocrine tissue displays extensive disorganization leading to pancreatitis-like autodigestion. Interestingly, our results suggest that Hippo signaling does not directly regulate the pancreas endocrine compartment as Yap expression is lost following endocrine specification through a Hippo-independent mechanism. Altogether, our results demonstrate that Hippo signaling plays a crucial role in pancreas development and provide novel routes to a better understanding of pathological conditions that affect this organ.

Detection of low-level PTFE contamination: An application of solid-state NMR to structure elucidation in the pharmaceutical industry.

We report a novel use of solid-state ¹9F nuclear magnetic resonance to detect and quantify polytetrafluoroethylene contamination from laboratory equipment, which due to low quantity (up to 1% w/w) and insolubility remained undetected by standard analytical techniques. Solid-state ¹9F NMR is shown to be highly sensitive to such fluoropolymers (detection limit 0.02% w/w), and is demonstrated as a useful analytical tool for structure elucidation of unknown solid materials.