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BACKGROUND AND PURPOSE Transient receptor potential cation channel subfamily M member 7 (TRPM7) is a bifunctional protein comprising a TRP ion channel segment linked to an α-type protein kinase domain. TRPM7 is essential for proliferation and cell growth. Up-regulation of TRPM7 function is involved in anoxic neuronal death, cardiac fibrosis and tumour cell proliferation. The goal of this work was to identify non-toxic inhibitors of the TRPM7 channel and to assess the effect of blocking endogenous TRPM7 currents on the phenotype of living cells. EXPERIMENTAL APPROACH We developed an aequorin bioluminescence-based assay of TRPM7 channel activity and performed a hypothesis-driven screen for inhibitors of the channel. The candidates identified were further assessed electrophysiologically and in cell biological experiments. KEY RESULTS TRPM7 currents were inhibited by modulators of small conductance Ca2+-activated K+ channels (KCa2.1-2.3; SK) channels, including the antimalarial plant alkaloid quinine, CyPPA, dequalinium, NS8593, SKA31 and UCL 1684. The most potent compound NS8593 (IC50 1.6 µM) specifically targeted TRPM7 as compared with other TRP channels, interfered with Mg2+-dependent regulation of TRPM7 channel and inhibited the motility of cultured cells. NS8593 exhibited full and reversible block of native TRPM7-like currents in HEK 293 cells, freshly isolated smooth muscle cells, primary podocytes and ventricular myocytes. CONCLUSIONS AND IMPLICATIONS This study reveals a tight overlap in the pharmacological profiles of TRPM7 and KCa2.1-2.3 channels. NS8593 acts as a negative gating modulator of TRPM7 and is well-suited to study functional features and cellular roles of endogenous TRPM7. [ABSTRACT FROM AUTHOR]

Background: Comorbidity is an important prognostic factor for elderly patients with head and neck cancer. Investigators are faced with the dilemma of selecting the appropriate comorbidity instrument for outcomes research in cancer. The goal of this study was to compare 2 general comorbidity indices with 2 disease-specific indices.Methods: The Surveillance, Epidemiology, and End Results (SEER)-Medicare-linked database was used to identify 15,493 patients with incident squamous cell carcinomas of the oral cavity, pharynx, and larynx first diagnosed between December 1983 and December 1994. Comorbid ailments were identified through the use of the International Classification of Diseases, 9th edition codes in the Medicare inpatient and outpatient claims for 7131 patients. The overall severity of comorbidity was classified according to 2 general comorbidity indices: the Charlson Comorbidity Index and the Klabunde Index, and 2 disease-specific indices: the Washington University Head and Neck Index and the Head and Neck Cancer Index. Overall survival was the primary end point. Cox proportional hazards analysis was used to assess the performance and discrimination of the comorbidity indices.Results: For each of the 4 comorbidity indices, there was a weak trend of worse survival with higher levels of comorbidity. The 2 general indices performed as well as the 2 disease-specific indices and no instrument clearly performed better than the others.Conclusion: Both the general and disease-specific comorbidity indices provided important prognostic information. The disease-specific indices did not perform better than the general indices. In this claims-based analysis, there was no apparent advantage to using a disease-specific index when attempting to predict overall survival. [ABSTRACT FROM AUTHOR]

To study the role of endothelial ATP-sensitive K+ channels in the regulation of vascular tone we examined the intracellular calcium concentration ([Ca2+]i) in coronary capillaries consisting only of endothelial cells. Coronary capillary fragments were isolated enzymatically from the guinea-pig heart and [Ca2+]i was determined by microfluorometry of fura-2 loaded cells. Low concentrations of the K+ channel opener diazoxide, which caused pronounced glibenclamide-sensitive hyperpolarization in capillaries, induced a rapid, transient rise in [Ca2+]i followed by a sustained elevation of [Ca2+]i (19 of 40 experiments). [Ca2+]i in the endothelial cells increased from 32 ± 7 nM at rest to 66 ± 11 nM at the peak ( n = 19). One third of the [Ca2+]i-transients showed irregular oscillations of [Ca2+]i. No significant difference in the [Ca2+]i-response induced by 100 nM or 1 μM diazoxide was found. Similar results were obtained with the K+ channel opener rilmakalim. Simultaneous measurements of the membrane potential and [Ca2+]i with fluorometric methods indicated that the hyperpolarization but not the [Ca2+]i-transient could be repeatedly induced in a single capillary by the K+ channel openers. Electrophysiological recordings of the membrane potential using the ”perforated patch” method ( n = 4), showed that rilmakalim (1 μM) induced hyperpolarization of capillaries towards the K+ equilibrium potential, confirming our fluorometric measurements. In conclusion, for the first time, these data indicate that K+ channel openers induce [Ca2+]i-transients in microvascular endothelial cells. This raises the possibility that these drugs not only act as synthetic vasoactive factors via hyperpolarizing smooth muscle cells but also via NO release of microvascular endothelial cells. Interestingly, only 100 nM diazoxide was sufficient for a maximal response, suggesting the expression of a new type of KATP-channel in coronary capillaries characterised by high sensitivity to diazoxide. [ABSTRACT FROM AUTHOR]

Cytomegalovirus (CMV) DNA levels were measured by quantitative-competitive polymerase chain reaction (PCR) in weekly leukocyte samples from 50 renal transplant recipients, including 23 with symptomatic and 27 with asymptomatic CMV infection. Peak and week 4 CMV DNA levels were higher in symptomatic subjects (P = .07 and .02, respectively). In a logistic regression model, the logarithm of the week 4 level independently predicted symptomatic infection (odds ratio, 1.78 for a 1 log10 increase; 95% confidence interval, 1.14-2.78; P = .01). All subjects whose week 4 level exceeded 1000 copies/100,000 leukocytes developed symptoms. In subjects with adequate samples for analysis, CMV levels declined exponentially with ganciclovir treatment, with an average half-life of 3.3 days. Levels exceeding 10,000 copies were associated with prolonged time to clearing of CMV DNA. Potential clinical applications of quantitative CMV PCR include predicting occurrence of symptomatic first episodes after transplantation and individualizing duration of antiviral therapy. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "Long-term remission after CD34+ -selected PBSCT in a patient with advanced intra-abdominal desmoplastic small round-cell tumor" in the August 31, 2009 issue.

The article comments on the study "Perioperative Complications after Living Kidney Donation: A National Study" by K.L. Lentine and others.

The author discusses the need for a national quality improvement initiative to reduce the costs of liver transplantation in children in the United States. The author cites a University of Michigan study which reported on the financial implications of surgical complications in pediatric liver transplant recipients. The Michigan researchers have re-confirmed that surgical complications are expensive and lead to a financial burden to payers, medical centers and the government.

Background and purpose: Mutations in the early growth response 2 gene (EGR2) cause demyelinating, but also axonal, neuropathies differing in severity and age of onset. Except for one family, all reported cases have autosomal dominant inheritance and mutations are localized within the three zinc finger (ZNF) DNA‐binding domain. The aim of this study was to provide a clinical and molecular analysis of a novel recessive mutation in EGR2. Methods: Clinical and electrophysiological assessments of three affected patients, from a consanguineous family, were performed. Genetic analyses of EGR2 were carried out by Sanger sequencing. Functional effects of clinical recessive mutations were assessed using a mammalian two‐hybrid assay. Results: A novel missense mutation (c.791C>T; p.P264L) in the homozygous state was detected outside the ZNF domains of the EGR2 gene. Three affected siblings presented with distal demyelinating polyneuropathy with severe sensory loss, progressive thoracolumbar scoliosis and trigeminal neuralgia. Respiratory compromise and cranial nerve dysfunction were also found. Our data indicate that the p.P264L mutation prevents interaction of EGR2 transcription factor with NAB corepressors, suggesting that a disruption of the NAB‐EGR2 protein interactions can result in dramatic neuropathy. Conclusion: Mutations in, or next to, the R1 domain of EGR2 should be considered with extreme caution for genetic counseling, since these could cause a severe neuropathy with an autosomal recessive manner of transmission. [ABSTRACT FROM AUTHOR]

The environmental impact of large language models (LLMs) in medicine spans carbon emission, water consumption and rare mineral usage. Prior-generation LLMs, such as GPT-3, already have concerning environmental impacts. Next-generation LLMs, such as GPT-4, are more energy intensive and used frequently, posing potentially significant environmental harms. We propose a five-step pathway for clinical researchers to minimise the environmental impact of the natural language algorithms they create., (© 2024 Royal Australasian College of Physicians.)

Background and Aims: Endothelial dysfunction (ED) is considered to be a major driver of the increased incidence of cardiovascular disease in primary aldosteronism (PA). The functionality of the epoxyeicosatrienoic acid (EET) pathway, involving the release of beneficial endothelium-derived lipid mediators, in PA is unknown. Evidence suggests this pathway to be disturbed in various models of experimental hypertension. We therefore assessed EET production in primary human coronary artery endothelial cells exposed to aldosterone excess and measured circulating EET in patients with PA., Methods: We used qPCR to investigate changes in the expression levels of essential genes for the synthesis and degradation of EET, calcium imaging to address the functional impact on overall endothelial function, as well as mass spectrometry to determine endothelial synthetic capacity to release EET upon stimulation. RNA-seq was performed to gain further mechanistic insights. Eicosanoid concentrations in patient's plasma were also determined by mass spectrometry., Results: Aldosterone, while eliciting proinflammatory VCAM1 expression and disturbed calcium response to acetylcholine, did not negatively affect stimulated release of endothelial EET. Likewise, no differences were observed in eicosanoid concentrations in plasma from patients with PA when compared to essential hypertensive controls. However, an inhibitor of soluble epoxide hydrolase abrogated aldosterone-mediated VCAM1 induction and led to a normalized endothelial calcium response probably by restoring expression of CHRNE., Conclusion: EET release appears intact despite aldosterone excess. Epoxide hydrolase inhibition may revert aldosterone-induced functional changes in endothelial cells. These findings indicate a potential new therapeutic principle to address ED, which should be explored in future preclinical and clinical trials., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Background and Hypothesis: Early steroid withdrawal (ESW) is often preferred over conventional steroid maintenance (CSM) therapy for kidney transplant recipients with low immunological risks because it may minimize immunosuppression-related adverse events while achieving similar transplant outcomes. However, the risk-benefit balance of ESW could be less favorable in retransplant recipients given their unique immunological risk profile. We hypothesized that the association of ESW with transplant outcomes would differ between first-transplant and retransplant recipients., Methods: To assess whether the impact of ESW differs between first and retransplant recipients, we studied 210 086 adult deceased-donor kidney transplant recipients using the Scientific Registry of Transplant Recipients. Recipients who discontinued maintenance steroids before discharge from transplant admission were classified with ESW; all others were classified with CSM. We quantified the association of ESW (vs. CSM) with acute rejection, death-censored graft failure, and death, addressing retransplant as an effect modifier, using logistic/Cox regression with inverse probability weights to control for confounders., Results: In our cohort, 26 248 (12%) were retransplant recipients. ESW was used in 30% of first-transplant and 20% of retransplant recipients. Among first-transplant recipients, ESW was associated with no significant difference in acute rejection (aOR = 1.04 [95% CI = 1.00-1.09]), slightly higher hazard of graft failure (HR = 1.09 [95% CI = 1.05-1.12]), and slightly lower mortality (HR = 0.93 [95% CI = 0.91-0.95]) compared to CSM. Nonetheless, among retransplant recipients, ESW was associated with notably higher risk of acute rejection (OR = 1.42 [95% CI = 1.29-1.57]; interaction p < 0.001) and graft failure (HR = 1.24 [95% CI = 1.14-1.34]; interaction p = 0.003), and similar mortality (HR = 1.01 [95% CI = 0.94-1.08]; interaction p = 0.04)., Conclusions: In retransplant recipients, the negative impacts of ESW on transplant outcomes appear to be non-negligible. A more conservatively tailored approach to ESW might be necessary for retransplant recipients., (© The Author(s) 2024. Published by Oxford University Press on behalf of the ERA.)

The non-selective transient receptor potential canonical 6 (TRPC6) cation channels have several physiological and pathophysiological effects. They are activated by the lipid second messenger diacylglycerol (DAG) and by non-lipidic compounds such as GSK 1702934A (GSK). Advances in photopharmacology led to the development of photoswitchable activators such as PhoDAG, OptoDArG, and OptoBI-1 that can be switched ON and OFF with the spatiotemporal precision of light. We aimed to elucidate whether these photopharmaceuticals allow for a reliable determination of the ion channel current kinetics. We performed electrophysiological whole-cell measurements in the overexpression system and analyzed TRPC6 currents induced by photoswitching. We observed distinct activation, deactivation and inactivation current kinetics suggesting that each photoswitchable activator elicits a distinct active channel state. Notably, the current kinetics strongly depended on the intensity of the light source. Altogether, photopharmaceuticals are advantageous for an extended biophysical characterization of whole-cell currents and provide insight into their gating mechanism., Competing Interests: The authors declare no competing interests., (© 2024 The Author(s).)

Introduction: Obstetric anal sphincter injury (OASI) is associated with serious morbidity and reduced quality of life. The role of anorectal manometry (ARM) to guide treatment is unclear. We aimed to define the role of ARM and symptom assessment after OASI in predicting anal incontinence at long-term follow-up., Methods: Prospective evaluation of 205 consecutive post-OASI women who underwent baseline ARM and symptom assessment in a tertiary setting was undertaken. Ninety-nine women were available for long-term follow-up (median 6.6 years). Associations between post-OASI ARM testing and short-term and long-term anal incontinence were examined in addition to clinical and obstetric factors., Results: Fourth degree tears and lower anal resting and squeeze pressures were associated with short-term anal incontinence. Women with anal incontinence at baseline and women with lower anal resting pressure were more likely to suffer from long-term fecal incontinence (FI). A best-fit cutoff value of 59 mm Hg for baseline anal resting pressure predicted long-term FI, and none of the short-term asymptomatic women with an anal resting pressure of >59 mm Hg reported FI at long-term follow-up., Discussion: Symptoms of anal incontinence and ARM in patients after OASI are both useful to predict subsequent long-term FI with a best-fit cutoff of 59 mm Hg for anal resting pressure. This provides rationale for routine ARM and accurate symptom assessment in all patients after OASI, to identify high-risk groups to follow and treat, and it may assist decision making regarding mode of subsequent obstetric deliveries., (Copyright © 2024 by The American College of Gastroenterology.)