Chemoproteomic Profiling Reveals that Anticancer Natural Product Dankastatin†B Covalently Targets Mitochondrial VDAC3.

Chlorinated gymnastatin and dankastatin alkaloids derived from the fungal strain Gymnascella dankaliensis have been reported to possess significant anticancer activity but their mode of action is unknown. These members possess electrophilic functional groups that can might undergo covalent bond formation with specific proteins to exert their biological activity. To better understand the mechanism of action of this class of natural products, we mapped the proteome-wide cysteine reactivity of the most potent of these alkaloids, dankastatin B, by using activity-based protein profiling chemoproteomic approaches. We identified a primary target of dankastatin B in breast cancer cells as cysteine C65 of the voltage-dependent anion-selective channel on the outer mitochondrial membrane VDAC3. We demonstrated direct and covalent interaction of dankastatin B with VDAC3. VDAC3 knockdown conferred hypersensitivity to dankastatin B-mediated antiproliferative effects in breast cancer cells, thus indicating that VDAC3 was at least partially involved in the anticancer effects of this natural product. Our study reveals a potential mode of action of dankastatin B through covalent targeting of VDAC3 and highlights the utility of chemoproteomic approaches in gaining mechanistic understanding of electrophilic natural products.

A cross-sectional study of pediatric hidradenitis suppurativa and the value of the International Hidradenitis Suppurativa Severity Score System (IHS4) as a pediatric clinical trial inclusion criteria.

BACKGROUND: Hidradenitis suppurativa (HS) often develops in pediatrics, but few interventional studies include pediatric patients. OBJECTIVES: This dual analysis of a pediatric HS cohort and typical eligibility criteria in adult trials aims to identify potential patient characteristics and inclusion criteria for future pediatric HS studies. METHODS: This cross-sectional and descriptive study is based on a prospectively collected data registry from an HS clinic. We also queried 125 HS studies from the Clinicaltrials.gov database and information from 61 interventional systemic HS drug trials was analyzed. RESULTS: The mean abscess and inflammatory nodule (AN) count in 81 pediatric subjects was 2.3 compared to 5.0 in adults with majority being Hurley stage I (39.5%, 32/81) or II (55.6%, 45/81). Most clinical trials required patients to be Hurley stage II/III with AN count of ≥3. CONCLUSION: When developing clinical trials for pediatric HS, it is imperative to consider how baseline characteristics impact recruitment and disease assessment. Frequently used eligibility criteria in adult trials may severely limit pediatric recruitment. Although our registry had a large adult sample size, the main limitation of this study was the relatively smaller pediatric sample size.

A new imaging entity consistent with partial ectopic posterior pituitary gland: report of six cases.

BACKGROUND: Abnormal posterior pituitary development including ectopic location has been associated with endocrine manifestations of anterior pituitary dysfunction. OBJECTIVE: We describe an unreported clinical and radiologic entity we call partial ectopic posterior pituitary for which associated endocrine consequences are not known. MATERIALS AND METHODS: We selected pediatric head MRI examinations from 2005 to 2017 based on the finding of a double midline sellar and suprasellar bright spot on T1-weighted sequence. Medical history, physical examination, pituitary hormonal profile and bone age evaluation were extracted from the medical record of the selected patients. An experienced pediatric neuroradiologist reviewed head MRIs, which were performed on 3-tesla (T) magnet and included at least sagittal T1-weighted imaging centered on the sella turcica obtained with and without fat suppression. RESULTS: In six cases, two midline bright spots were identified on T1-weighted sequences obtained both with and without fat suppression. While one spot was located at the expected site of the neurohypophysis in the posterior sella, the second one was in the region of the median eminence, suggesting partial ectopic posterior pituitary gland. Growth hormone deficiency, either isolated (n=1) or combined with thyroid stimulating hormone deficiency (n=1) was found. None of the children had clinical signs of posterior pituitary dysfunction. CONCLUSION: We describe an unreported imaging entity suggesting partial ectopic posterior pituitary gland in six children. Anterior pituitary hormone deficiencies might be detected in those children and long-term follow-up could provide additional information on the development of other pituitary hormone deficiencies.

Broken heart syndrome triggered by an obstructive goiter not associated with thyrotoxicosis.

PURPOSE: Takotsubo cardiomyopathy (TC) is described as transient ventricular dysfunction following emotional or physical trauma. A few reports have described patients with TC in association with various circumstances of thyrotoxicosis. We report an unusual case of TC in a patient with a large retrosternal goiter and normal thyroid function. We speculate that TC was triggered by compromise of tracheal flow induced by the goiter. CLINICAL FEATURE: A 68-yr-old woman without primary heart disease presented with cardiorespiratory collapse requiring ventilatory and cardiovascular support, including placement of an intra-aortic balloon pump. She was diagnosed with a severe form of TC based on characteristic echocardiography findings and clinical course. Within less than a week, her myocardial function completely normalized. The patient was later found to have a large retrosternal goiter compressing her trachea, though her thyroid function was normal. A total thyroidectomy was eventually performed, and she made a full recovery. Subsequently, the patient was found to have a positive JAK2 mutation for a myeloproliferative disorder. CONCLUSIONS: Takotsubo cardiomyopathy may be regarded as the final common pathway of cardiac dysfunction triggered by various stress conditions, in this case, a large retrosternal goiter not associated with thyrotoxicosis and likely exacerbated by severe leukocytosis related to a myeloproliferative disorder.

Surgical Procedural Definitions for Hidradenitis Suppurativa Developed by Expert Delphi Consensus.

Importance: Various surgical approaches for hidradenitis suppurativa (HS) have been described in the literature, but the nomenclature is inconsistent. Excisions have been described as wide, local, radical, and regional with variable descriptions of margins. Deroofing procedures have been described with various approaches though descriptions of the approach are generally more uniform. No international consensus has been formed to globally standardize terminology for HS surgical procedures. Lack of such agreement may contribute to misunderstanding or misclassification in HS procedural research studies and impair clear communication among clinicians or between clinicians and patients. Objective: To create a set of standard definitions for HS surgical procedures. Design, Setting, and Participants: This consensus agreement study was conducted from January to May 2021 using the modified Delphi consensus method to reach agreement among a group of international HS experts regarding standardized definitions for an initial set of HS surgical terms, including "incision and drainage," "deroofing/unroofing," "excision," "lesional excision," and "regional excision," ultimately expanded to 10 terms. Provisional definitions were drafted based on existing literature and discussion among an expert 8-member steering committee. Online surveys were disseminated to members of the HS Foundation, direct contacts of the expert panel, and the HSPlace listserv to reach physicians with considerable experience with HS surgery. Consensus was defined as greater than 70% agreement to accept a definition. Results: In the first and second modified Delphi round, 50 and 33 experts participated, respectively. Ten surgical procedural terms and definitions reached consensus with greater than 80% agreement. Overall, the term "local" excision was abandoned and replaced with the descriptors "lesional" or "regional" excision. Of note, "regional" replaced the terms "wide" and "radical" excision. Furthermore, modifiers such as "partial" vs "complete" should also be included when describing surgical procedures. A combination of these terms helped formulate the final glossary of HS surgical procedural definitions. Conclusion and Relevance: An international group of HS experts agreed on a set of definitions describing surgical procedures frequently used by clinicians and in the literature. The standardization and application of such definitions are vital to allow for accurate communication, reporting consistency, and uniform data collection and study design in the future.

Chemoproteomic Profiling Reveals that Anti-Cancer Natural Product Dankastatin B Covalently Targets Mitochondrial VDAC3.

Chlorinated gymnastatin and dankastatin alkaloids derived from the fungal strain Gymnascella dankaliensis have been reported to possess significant anti-cancer activity but their mode of action is unknown. These members possess electrophilic functional groups that may undergo covalent bond formation with specific proteins to exert their biological activity. To better understand the mechanism of action of this class of natural products, we mapped the proteome-wide cysteine-reactivity of the most potent of these alkaloids, dankastatin B, using activitybased protein profiling chemoproteomic approaches. We identified a primary target of dankastatin B in breast cancer cells as cysteine C65 of the voltage-dependent anion selective channel on the outer mitochondrial membrane VDAC3. We demonstrated direct and covalent interaction of dankastatin B with VDAC3. VDAC3 knockdown conferred hyper-sensitivity to dankastatin B-mediated anti-proliferative effects in breast cancer cells indicating that VDAC3 was at least partially involved in the anti-cancer effects of this natural product. Our study reveals a potential mode of action of dankastatin B through covalent targeting of VDAC3 and highlight the utility of chemoproteomic approaches in gaining mechanistic understanding of electrophilic natural products.

Genetic Variants Associated With Hidradenitis Suppurativa.

Importance: Hidradenitis suppurativa (HS) is a common and severely morbid chronic inflammatory skin disease that is reported to be highly heritable. However, the genetic understanding of HS is insufficient, and limited genome-wide association studies (GWASs) have been performed for HS, which have not identified significant risk loci. Objective: To identify genetic variants associated with HS and to shed light on the underlying genes and genetic mechanisms. Design, Setting, and Participants: This genetic association study recruited 753 patients with HS in the HS Program for Research and Care Excellence (HS ProCARE) at the University of North Carolina Department of Dermatology from August 2018 to July 2021. A GWAS was performed for 720 patients (after quality control) with controls from the Add Health study and then meta-analyzed with 2 large biobanks, UK Biobank (247 cases) and FinnGen (673 cases). Variants at 3 loci were tested for replication in the BioVU biobank (290 cases). Data analysis was performed from September 2021 to December 2022. Main Outcomes and Measures: Main outcome measures are loci identified, with association of P < 1 × 10-8 considered significant. Results: A total of 753 patients were recruited, with 720 included in the analysis. Mean (SD) age at symptom onset was 20.3 (10.57) years and at enrollment was 35.3 (13.52) years; 360 (50.0%) patients were Black, and 575 (79.7%) were female. In a meta-analysis of the 4 studies, 2 HS-associated loci were identified and replicated, with lead variants rs10512572 (P = 2.3 × 10-11) and rs17090189 (P = 2.1 × 10-8) near the SOX9 and KLF5 genes, respectively. Variants at these loci are located in enhancer regulatory elements detected in skin tissue. Conclusions and Relevance: In this genetic association study, common variants associated with HS located near the SOX9 and KLF5 genes were associated with risk of HS. These or other nearby genes may be associated with genetic risk of disease and the development of clinical features, such as cysts, comedones, and inflammatory tunnels, that are unique to HS. New insights into disease pathogenesis related to these genes may help predict disease progression and novel treatment approaches in the future.

Whole-Exome Sequencing in Congenital Hypothyroidism Due to Thyroid Dysgenesis.

Context: Congenital hypothyroidism due to thyroid dysgenesis (CHTD) is a predominantly sporadic and nonsyndromic (NS) condition of unknown etiology. NS-CHTD shows a 40-fold increase in relative risk among first-degree relatives (1 in 100 compared with a birth prevalence of 1 in 4000 in the general population), but a discordance rate between monozygotic (MZ) twins of 92%. This suggests a two-hit mechanism, combining a genetic predisposition (incomplete penetrance of inherited variants) with postzygotic events (accounting for MZ twin discordance). Objective: To evaluate whether whole-exome sequencing (WES) allows to identify new predisposing genes in NS-CHTD. Methods: We performed a case-control study by comparing the whole exome of 36 nonconsanguineous cases of NS-CHTD (33 with lingual thyroid ectopy and 3 with athyreosis, based on technetium pertechnetate scintigraphy at diagnosis) with that of 301 unaffected controls to assess for enrichment in rare protein-altering variants. We performed an unbiased approach using a gene-based burden with a false discovery rate correction. Moreover, we identified all rare pathogenic and likely pathogenic variants, based on in silico prediction tools, in 27 genes previously associated with congenital hypothyroidism (CH) (thyroid dysgenesis [TD] and dyshormonogenesis). Results: After correction for multiple testing, no enrichment in rare protein-altering variants was observed in NS-CHTD. Pathogenic or likely pathogenic variants (21 variants in 12 CH genes) were identified in 42% of cases. Eight percent of cases had variants in more than one gene (oligogenic group); these were not more severely affected than monogenic cases. Moreover, cases with protein-altering variants in dyshormonogenesis-related genes were not more severely affected than those without. Conclusions: No new predisposing genes were identified following an unbiased analysis of WES data in a well-characterized NS-CHTD cohort. Nonetheless, the discovery rate of rare pathogenic or likely pathogenic variants was 42%. Eight percent of the cases harbored multiple variants in genes associated with TD or dyshormonogenesis, but these variants did not explain the variability of hypothyroidism observed in dysgenesis. WES did not identify a genetic cause in NS-CHTD cases, confirming the complex etiology of this disease. Additional studies in larger cohorts and/or novel discovery approaches are required.

Vulvoperineal Hidradenitis Suppurativa: Diagnosis, Treatment, and Management of Deformities.

IMPORTANCE: Hidradenitis suppurativa (HS) is a chronic, inflammatory disorder affecting skin of intertriginous areas that is often encountered and treated by nondermatologic specialists. OBJECTIVE: The purpose of this literature review is to provide a comprehensive, clinical source of information on HS as it relates to incidence of disease, pathophysiology, diagnosis, and overall management of this condition. EVIDENCE ACQUISITION: Sources were obtained through a comprehensive literature search using PubMed and PMC. Various terms were used to query the database, including "hidradenitis suppurativa," "pathogenesis," "prevalence," "management," "surgery," "perineal," and "vulva." RESULTS: Underreported prevalence and unknown pathogenesis have subsequently led to variable approaches in clinical management, often employing a combination of medical and surgical management. CONCLUSIONS: Early diagnosis and treatment of HS may lead to better disease control and minimize patients' associated morbidity related to disease. RELEVANCE: Knowledge of vulvoperineal hidradenitis is necessary for gynecologists and primary care physicians to ensure early diagnosis, management, and referral for optimal patient outcomes.

Is diabetic ketoacidosis at disease onset a result of missed diagnosis?

OBJECTIVE: To determine the frequency of medical encounters before diagnosis of diabetes in children in Ontario, Canada; to determine risk factors for diabetic ketoacidosis (DKA). RESEARCH DESIGN: All medical encounters within 4 weeks before date of diagnosis for all new cases of diabetes in children <18 years were identified from April 1994 to March 2000 by use of administrative databases. The main outcome measure was the frequency of medical encounters before diagnosis in children presenting with and without DKA. RESULTS: A total of 3947 new cases of diabetes were identified, 735 (18.6%) with DKA. DKA rates were 39.7% for children < or =3 years and 16.3% for children >3 years (P < .001). During the week before diagnosis, 285 children with DKA (38.8%) and 1104 children with diabetes without DKA (34.4%; P = .026) had at least 1 medical visit. Children with diabetes overall had more medical encounters before diagnosis than control subjects. Children with DKA were less likely to have had relevant laboratory testing before diagnosis than children with diabetes without DKA. CONCLUSIONS: Children with diabetes presenting with DKA more frequently had a medical encounter before diagnosis compared with children with diabetes without DKA. These data have important implications for enhancing public and physician awareness of diabetes in children.

Parenteral amino acid supplementation with high-dose insulin prevents hypoaminoacidemia during cardiac surgery.

OBJECTIVES: Surgery triggers a stress response that produces insulin resistance and hyperglycemia. During cardiac surgery, the administration of high-dose insulin along with dextrose titration maintains normoglycemia, but dramatically decreases plasma amino acids (AAs) compared with preoperative fasting levels. Hypoaminoacidemia limits protein synthesis and prevents anabolic responses after surgery. We investigated whether parenteral infusion of AAs during and immediately after cardiac surgery would prevent hypoaminoacidemia in patients who receive high-dose insulin therapy. METHODS: Sixteen patients undergoing coronary artery bypass grafting surgery were randomly allocated to receive AAs with % kcal equivalent to either 20% (n = 8) or 35% (n = 8) of their measured resting energy expenditure (REE). Insulin was infused at a constant rate of 5 mU/(kg × min), whereas dextrose was titrated to maintain normoglycemia during and until 5 h after surgery. Plasma AA concentrations were measured at baseline before and after surgery. RESULTS: Compared with the 20% AA group after surgery, AA concentrations were significantly higher in the 35% AA group for 12 of 20 AAs (P < 0.032), including all branched-chain AAs. In the 20% AA group, total essential AAs decreased by 21% and nonessential AAs decreased by 14% after surgery compared with preoperative fasting levels. In contrast, giving 35% AAs prevented this unfavorable decrease in AAs, and in fact allowed for a 23% and 12% increase in essential and nonessential AAs, respectively. CONCLUSIONS: AA supplementation at 35% REE, but not 20% REE, can effectively prevent hypoaminoacidemia caused by high-dose insulin therapy during cardiac surgery.

The shortened combined clonidine and arginine test for growth hormone deficiency is practical and specific: a diagnostic accuracy study.

BACKGROUND: The growth hormone (GH) stimulation protocols for clonidine and arginine tests are non-standardized and can be lengthy. We examined the specificity of both tests using a shorter duration of timed samples: 90 min for clonidine and 60 min for arginine. METHODS: We retrospectively studied all children who had GH stimulation with clonidine and arginine to test for GH deficiency (GHD). We compared the diagnostic accuracy of both reference and new shortened test (index). RESULTS: We reviewed 243 charts (11.4±4.1 years old; 74.5% males). The combined reference test was performed on 159 children, 29 (18.3%) tested positive for GHD on the combined index test, Kappa 0.98, false positive rate 1 (0.8%), specificity 0.99, 95th CI (0.96-1), and p=1.0. The specificity of both the clonidine and arginine single index tests was 0.98%. CONCLUSIONS: The shortened clonidine and arginine stimulation index tests have good specificity. This is a viable option for testing children for GHD.

Catch-up growth in severe juvenile hypothyroidism: treatment with a GnRH analog.

Anecdotal reports suggest that the addition of a gonadotropin releasing hormone (GnRH) analog (GnRHa) in addition to L-thyroxine (LT4) replacement may increase adult stature in children with severe longstanding hypothyroidism by prolonging the pubertal growth period. This retrospective chart review compares the height outcome and body mass index in 33 children (21 treated with LT4 alone and 12 treated with LT4 + GnRHa) with severe longstanding hypothyroidism and bone age delay. Seventeen controls and six GnRHa-treated patients were followed to adult height (BA >14 yr [F]/16 yr [M] and/or growth velocity < 2 cm/yr). At diagnosis, GnRHa-treated patients were 1) older and shorter for chronological age, and 2) more advanced in puberty and bone age. Despite these differences, at adult height, both groups had similar improvements in height Z scores, similar height deficits, and comparable adult heights. Changes in BMI Z score were similar for both groups. Our study suggests that the addition of GnRHa to LT4 may improve interval growth without imposing a risk of obesity in children with longstanding severe hypothyroidism.

Glucose and insulin administration while maintaining normoglycemia inhibits whole body protein breakdown and synthesis after cardiac surgery.

We investigated the effect of insulin administered as part of a hyperinsulinemic-normoglycemic clamp on protein metabolism after coronary artery bypass grafting (CABG) surgery. Eighteen patients were studied, with nine patients in the control group receiving standard metabolic care and nine patients receiving insulin (5 mU·kg(-1)·min(-1)). Whole body glucose production, protein breakdown, synthesis, and oxidation were determined using stable isotope tracer kinetics (l-[1-(13)C]leucine, [6,6-(2)H2]glucose) before and 6 h after the procedure. Plasma amino acids, cortisol, and lactate were also measured. Endogenous glucose production (preoperatively 10.0 ± 1.6, postoperatively 3.7 ± 2.5 µmol·kg(-1)·min(-1); P = 0.0001), protein breakdown (preoperatively 105.3 ± 9.8, postoperatively 85.2 ± 9.2 mmol·kg(-1)·h(-1); P = 0.0005) and synthesis (preoperatively 88.7 ± 8.7, postoperatively 72.4 ± 8.4 mmol·kg(-1)·h(-1); P = 0.0005) decreased in the presence of hyperinsulinemia, whereas both parameters remained unchanged in the control group. A positive correlation between endogenous glucose production and protein breakdown was observed in the insulin group (r(2) = 0.385). Whole body protein oxidation and balance decreased after surgery in patients receiving insulin without reaching statistical significance. In the insulin group the plasma concentrations of 13 of 20 essential and nonessential amino acids decreased to a significantly greater extent than in the control group. In summary, supraphysiological hyperinsulinemia, while maintaining normoglycemia, decreased whole body protein breakdown and synthesis in patients undergoing CABG surgery. However, net protein balance remained negative.

Fasting blood glucose levels in patients presenting for elective surgery.

OBJECTIVE: The incidence of diabetes mellitus (DM) is increasing worldwide; however, its diagnosis is often delayed. Identifying patients with abnormal fasting blood glucose (FBG) levels preoperatively may have important implications for immediate and long-term outcomes. The aim of the present study was to determine the prevalence of impaired fasting glucose (IFG) and provisional diagnosis of DM (PDD) with potential risk factors in patients presenting for elective surgery. METHODS: We measured FBG in consecutive adult patients undergoing elective non-cardiac surgery from September 2006 to August 2007. Patient age, sex, body mass index, and FBG were collected in the morning of their scheduled intervention. FBG was classified according to the World Health Organization categorization. Patients with a history of DM were excluded from the final analysis. The prevalence of IFG and PDD and odds ratio for risk factors were calculated. RESULTS: Four hundred ninety-three patients without a prior diagnosis of DM were sampled; 19.3% (95 of 493) had IFG and 6.5% (32 of 493) had PDD. Male subjects had a greater risk of PDD than female subjects (odds ratio 2.5, 95% confidence interval 1.2-5.5, P = 0.017). Increased body mass index was not a risk factor for IFG or PDD. The prevalence of IFG but not of PDD had a tendency to increase with age after 40 y. CONCLUSION: More than 25% of patients without a prior diagnosis of DM presenting for elective surgery had increased FBG levels. Obtaining this information may initiate not only an earlier detection of DM in some patients but also affect acute perioperative management and outcomes.

High-dose insulin administration is associated with hypoaminoacidemia during cardiac surgery.

Although the effects of insulin on glucose homeostasis are well recognized in surgical patients, its effect on perioperative protein metabolism has received little attention. The purpose of this study was to examine the effect of high-dose insulin therapy on the plasma concentrations of amino acids (AAs) in patients undergoing coronary artery bypass grafting surgery. We studied 20 nondiabetic patients scheduled for elective coronary artery bypass grafting surgery. Patients were randomly allocated to receive either standard metabolic care (target glycemia 6.0-10.0 mmol/L, control group, n = 10) or high-dose insulin therapy (insulin group, n = 10). Insulin was administered at 5 mU·kg(-1)·min(-1) beginning at skin incision. Simultaneously, 20% dextrose was infused at a variable rate adjusted to maintain glycemia between 4.0 and 6.0 mmol/L. Plasma AAs, glucose, cortisol, and insulin were measured immediately before surgery and at sternal closure. Differences in mean values were assessed by Student t test. Plasma concentrations of all AAs decreased in the insulin group, with 15 of 22 AAs, including all branched-chain AAs, being significantly lower at sternal closure when compared with the control group. At the end of surgery, plasma glucose concentration was significantly lower in the insulin group (4.2 ± 0.6 vs 7.3 ± 1.0 mmol/L, P = .0001), whereas plasma cortisol levels did not show any difference between groups. High-dose insulin therapy resulted in a significant reduction in plasma AAs, particularly branched-chain AAs, during cardiac surgery.

Self-monitoring of blood glucose in children and teens with diabetes.

Improved metabolic control has unequivocally been demonstrated to delay the onset and slow the progression of microvascular complications in adolescents and adults with diabetes mellitus. Growing evidence also supports the association of tighter glucose control and more frequent blood glucose monitoring. Therefore, self-monitoring of blood glucose (SMBG) has become a fundamental part of diabetes care in children. Here, we review recent advances and ongoing trends in glucose monitoring in children with diabetes. Technologies have been developed to improve patient compliance with recommended monitoring, requiring less blood, involving less pain, and providing results more quickly. Alternate-site testing (AST) is also a potential means of improving patient compliance with SMBG by avoiding the sensitive fingertip area. The Continuous Glucose Monitoring System (CGMS) and the GlucoWatch Biographer are two recent tools that can track glucose levels continuously. However, inconsistency in their accuracy and precision remain challenges when using these technologies to guide management.