Factors affecting accuracy of clinical staging in resectable non-small cell lung cancer in a real-world study.

BACKGROUND: The clinical staging of non-small cell lung cancer (NSCLC) is well known to be related to their prognosis. However, there is usually a discrepancy between clinical staging and pathological staging. There are few analyses of clinical staging accuracy in patients with NSCLC. We compared the concordance rate between clinical and pathological staging of NSCLC and evaluated factors affecting the accuracy in real-world data. METHODS: Altogether, 811 patients with primary NSCLC who had undergone curative lung resection surgery in Severance Hospital from January 2019 to December 2020 were retrospectively reviewed. We used the eighth edition of the American Joint Committee on Cancer TNM staging. RESULTS: Among 811 patients, endobronchial ultrasound (EBUS) and positron emission tomography (PET-CT) were performed in 31.6% and 96.7%, respectively. The concordance rates between clinical and pathological TNM staging, T factor, and N factor, were 68.7%, 77.7%, and 85.8%, respectively. With multivariable logistic regression analysis, current smokers (OR 0.49; 95% CI: 0.32-0.76, p = 0.001) and a higher clinical stage (p < 0.001) contributed to the clinical staging inaccuracy. Additionally, the presence of a bronchoscopy specialist was significantly associated with clinical staging accuracy (OR 1.53; 95% CI: 1.10-2.13, p = 0.011). CONCLUSION: Clinical staging accuracy in NSCLC improved compared to before the widespread use of PET-CT and EBUS in clinical staging work-up. Smoking history and absence of expert bronchoscopy specialists showed a meaningful correlation with the inaccuracy of clinical staging. Thus, training more bronchoscopy experts would improve the staging accuracy of NSCLC, which could positively affect the prognosis of NSCLC.

A Quantitative Measure of Pain with Current Perception Threshold, Pain Equivalent Current, and Quantified Pain Degree: A Retrospective Study.

Background: As a subjective sensation, pain is difficult to evaluate objectively. The assessment of pain degree is largely dependent on subjective methods such as the numeric rating scale (NRS). The PainVisionTM system has recently been introduced as an objective pain degree measurement tool. The purpose of this study was to analyze correlations between the NRS and the current perception threshold (CPT), pain equivalent current (PEC), and quantified pain degree (QPD). Methods: Medical records of 398 subjects who visited the pain clinic in a university hospital from March 2017 to February 2019 were retrospectively reviewed. To evaluate the pain degree, NRS, CPT, PEC, and QPD were measured. Subjects were categorized into two groups: the Pain group (n = 355) and the No-pain group (n = 43). Results: The NRS showed a negative correlation with CPT (R = -0.10, p = 0.054) and a positive correlation with QPD (R = 0.13, p = 0.008). Among various diseases, only spinal disease patients showed a negative correlation between CPT and NRS (R = -0.22, p = 0.003). Additionally, there were significant differences in CPT and QPD between the Pain and No-pain groups (p = 0.005 and p = 0.002, respectively). Conclusions: CPT and QPD measured using the PainVisionTM system could be used to estimate pain intensity and the presence of pain. These parameters would be considered useful for predicting pain itself and its intensity.

Stimulator of interferon genes is required for Toll-Like Receptor-8 induced interferon response.

The innate immune system is equipped with multiple receptors to detect microbial nucleic acids and induce type I interferon (IFN) to restrict viral replication. When dysregulated these receptor pathways induce inflammation in response to host nucleic acids and promote development and persistence of autoimmune diseases like Systemic Lupus Erythematosus (SLE). IFN production is regulated by the Interferon Regulatory Factor (IRF) transcription factor family of proteins that function downstream of several innate immune receptors such as Toll-like receptors (TLRs) and Stimulator of Interferon Genes (STING). Although both TLRs and STING activate the same downstream molecules, the pathway by which TLRs and STING activate IFN response are thought to be independent. Here we show that STING plays a previously undescribed role in human TLR8 signaling. Stimulation with the TLR8 ligands induced IFN secretion in primary human monocytes, and inhibition of STING reduced IFN secretion from primary monocytes from 8 healthy donors. We demonstrate that TLR8-induced IRF activity was reduced by STING inhibitors. Moreover, TLR8-induced IRF activity was blocked by inhibition or loss of IKKε, but not TBK1. Bulk RNA transcriptomic analysis supported a model where TLR8 induces transcriptional responses associated with SLE that can be downregulated by inhibition of STING. These data demonstrate that STING is required for full TLR8-to-IRF signaling and provide evidence for a new framework of crosstalk between cytosolic and endosomal innate immune receptors, which could be leveraged to treat IFN driven autoimmune diseases. Background: High levels of type I interferon (IFN) is characteristic of multiple autoimmune diseases, and while TLR8 is associated with autoimmune disease and IFN production, the mechanisms of TLR8-induced IFN production are not fully understood. Results: STING is phosphorylated following TLR8 signaling, which is selectively required for the IRF arm of TLR8 signaling and for TLR8-induced IFN production in primary human monocytes. Conclusion: STING plays a previously unappreciated role in TLR8-induced IFN production. Significance: Nucleic acid-sensing TLRs contribute to development and progression of autoimmune disease including interferonopathies, and we show a novel role for STING in TLR-induced IFN production that could be a therapeutic target.

Aspergillus Galactomannan Titer as a Diagnostic Marker of Invasive Pulmonary Aspergillosis in Lung Transplant Recipients: A Single-Center Retrospective Cohort Study.

Invasive pulmonary aspergillosis (IPA) can occur in immunocompromised patients, and an early detection and intensive treatment are crucial. We sought to determine the potential of Aspergillus galactomannan antigen titer (AGT) in serum and bronchoalveolar lavage fluid (BALF) and serum titers of beta-D-glucan (BDG) to predict IPA in lung transplantation recipients, as opposed to pneumonia unrelated to IPA. We retrospectively reviewed the medical records of 192 lung transplant recipients. Overall, 26 recipients had been diagnosed with proven IPA, 40 recipients with probable IPA, and 75 recipients with pneumonia unrelated to IPA. We analyzed AGT levels in IPA and non-IPA pneumonia patients and used ROC curves to determine the diagnostic cutoff value. The Serum AGT cutoff value was 0.560 (index level), with a sensitivity of 50%, specificity of 91%, and AUC of 0.724, and the BALF AGT cutoff value was 0.600, with a sensitivity of 85%, specificity of 85%, and AUC of 0.895. Revised EORTC suggests a diagnostic cutoff value of 1.0 in both serum and BALF AGT when IPA is highly suspicious. In our group, serum AGT of 1.0 showed a sensitivity of 27% and a specificity of 97%, and BALF AGT of 1.0 showed a sensitivity of 60% and a specificity of 95%. The result suggested that a lower cutoff could be beneficial in the lung transplant group. In multivariable analysis, serum and BALF AGT, with a minimal correlation between the two, showed a correlation with a history of diabetes mellitus.

Superficial temporal artery injury and delayed post-cranioplasty infection.

OBJECTIVE: Complications after cranioplasty after decompressive craniectomy (DC) have been reported to be as high as 40%. The superficial temporal artery (STA) is at substantial risk for injury in standard reverse question-mark incisions that are typically used for unilateral DC. The authors hypothesize that STA injury during craniectomy predisposes patients to post-cranioplasty surgical site infection (SSI) and/or wound complication. METHODS: A retrospective study of all patients at a single institution who underwent cranioplasty after decompressive craniectomy and who underwent imaging of the head (computed tomography angiogram, magnetic resonance imaging with intravenous contrast, or diagnostic cerebral angiography) for any indication between the two procedures was undertaken. The degree of STA injury was classified and univariate statistics were used to compare groups. RESULTS: Fifty-four patients met inclusion criteria. Thirty-three patients (61%) had evidence of complete or partial STA injury on pre-cranioplasty imaging. Nine patients (16.7%) developed either an SSI or wound complication after cranioplasty and, among these, four (7.4%) experienced delayed (>2 weeks from cranioplasty) complications. Seven of 9 patients required surgical debridement and cranioplasty explant. There was a stepwise but non-significant increase in post-cranioplasty SSI (STA present: 10%, STA partial injury: 17%, STA complete injury: 24%, P=0.53) and delayed post-cranioplasty SSI (STA present: 0%, STA partial injury: 8%, STA complete injury: 14%, P=0.26). CONCLUSIONS: There is a notable but statistically non-significant trend toward increased rates of SSI in patients with complete or partial STA injury during craniectomy.

Monocyte distribution width compared with C-reactive protein and procalcitonin for early sepsis detection in the emergency department.

PURPOSE: Monocyte distribution width (MDW) has been suggested as an early biomarker of sepsis, but few studies have compared MDW with conventional biomarkers, including C-reactive protein (CRP) and procalcitonin (PCT). This study evaluated MDW as a biomarker for sepsis and compared it with CRP and PCT. MATERIALS AND METHODS: Patients aged 18-80 years who visited the emergency department were screened and prospectively enrolled in a tertiary medical center. Complete blood count, MDW, CRP, and PCT were examined. Diagnostic performance for sepsis was tested using the area under the curve (AUC) of receiver operating characteristic (ROC) curves, sensitivity, and specificity. RESULTS: In total, 665 patients were screened, and 549 patients with valid laboratory test results were included in the analysis. The patients were categorized into three groups according to the Sepsis-3 criteria: non-infection, infection, and sepsis. MDW showed the highest value in the sepsis group (median [interquartile range], 24.0 [20.8-27.8]). The AUC values for MDW, CRP, PCT, and white blood cells for predicting sepsis were 0.71 (95% confidence interval [CI], 0.67-0.75), 0.75 (95% CI, 0.71-0.78], 0.76 (95% CI, 0.72-0.79, and 0.61 (95% CI, 0.57-0.65), respectively. With the optimal cutoff value of the cohort, the sensitivity was 83.0% for MDW (cutoff, 19.8), 69.7% for CRP (cutoff, 4.0), and 76.6% for PCT (cutoff, 0.05). The combination of quick Sequential Organ Failure Assessment (qSOFA) with MDW improved the AUC (0.76; 95% CI, 0.72-0.80) to a greater extent than qSOFA alone (0.67; 95% CI, 0.62-0.72). CONCLUSIONS: MDW reflected a diagnostic performance comparable to that of conventional diagnostic markers, implying that MDW is an alternative biomarker. The combination of MDW and qSOFA improves the diagnostic performance for early sepsis.

Association Between Three-Dimensional Left Ventricular Outflow Tract Area and Gradients After Myectomy in Hypertrophic Obstructive Cardiomyopathy.

OBJECTIVE: Determine whether the intraoperative three-dimensional left ventricular outflow tract cross-sectional area may be inversely correlated with pressure gradients as a determinant of surgical success after septal myectomy in hypertrophic cardiomyopathy patients. DESIGN: Perioperative data were obtained by retrospective review. SETTING: Toronto General Hospital, University of Toronto, Toronto, Canada, a tertiary hospital. PARTICIPANTS: The study comprised 67 patients with hypertrophic obstructive cardiomyopathy. INTERVENTIONS: Transthoracic and intraoperative transesophageal echocardiographic assessment of pressure gradients. Transesophageal measurement of the three-dimensional left ventricular outflow tract cross-sectional area. MEASUREMENTS AND MAIN RESULTS: The smallest left ventricular outflow tract area increased on average 1.883 cm2 (98.3%) after septal myectomy. There was a significant correlation between the increase in the area and the transesophageal pressure gradients (r = -0.32; p = 0.01) after myectomy, but none with postoperative transthoracic gradients at rest (r = -0.10; p = 0.42). Postoperative transesophageal and transthoracic gradients were significantly correlated (r = 0.26; p = 0.04). The best risk factors to predict high residual gradients were preoperative transesophageal gradient >97 mmHg, postoperative transesophageal area <3.16 cm2, and moderate or more residual transesophageal mitral regurgitation (specificity 89%, 81%, and 78%, respectively). CONCLUSIONS: Three-dimensional left ventricular outflow tract area measurements with transesophageal echocardiography after myectomy correlated fairly well with postoperative transesophageal pressure gradients. Patients with residual transthoracic elevated gradients after surgery at follow-up had a smaller transesophageal area and higher transesophageal pressure gradients immediately after the procedure. However, transesophageal pressure gradients after myectomy correlated poorly with follow-up transthoracic gradients at rest.

Assisted Breathing with a Diaphragm Pacing System: A Systematic Review.

PURPOSE: Patients with respiratory failure associated with neurological dysfunction often require mechanical ventilator support, which poses increased economic burden and ventilator-associated complications. A diaphragm pacing system (DPS) is an implanted device that provides respiratory support for such patients. In this systematic review, we reviewed the literature to assess the safety and efficacy of DPS for patients with respiratory failure resulting from amyotrophic lateral sclerosis (ALS) or cervical spinal cord injuries. MATERIALS AND METHODS: The following databases were searched from July 10 to July 30, 2018: MEDLINE, EMBASE, Cochran library, KoreaMed, Research Information Sharing Service, Korean studies Information Service System, Korea Institute of Science and Technology Information, and Korean Medical database. The abstracts and full texts of the searched articles were reviewed by two reviewers. RESULTS: The search keywords generated 197 articles: two randomized controlled trials, two case-control studies, and one case report involving patients with ALS; one cohort study, one case-control study, and two case reports involving patients with cervical spine injury; and one case report involving patients with both conditions were included. The primary outcome was safety profile (complications and adverse event) and efficacy (overall survival and sleep improvement). Complications and adverse events were more common in patients with ALS and spinal cord injury receiving DPS than in controls. Efficacy outcomes were inconsistent across ALS studies. CONCLUSION: Based on safety and efficacy results, we do not support using DPS to manage respiratory failure in patients with ALS or cervical spine injury.

Caenorhabditis elegans Lipin 1 moderates the lifespan-shortening effects of dietary glucose by maintaining ω-6 polyunsaturated fatty acids.

Excessive glucose causes various diseases and decreases lifespan by altering metabolic processes, but underlying mechanisms remain incompletely understood. Here, we show that Lipin 1/LPIN-1, a phosphatidic acid phosphatase and a putative transcriptional coregulator, prevents life-shortening effects of dietary glucose on Caenorhabditis elegans. We found that depletion of lpin-1 decreased overall lipid levels, despite increasing the expression of genes that promote fat synthesis and desaturation, and downregulation of lipolysis. We then showed that knockdown of lpin-1 altered the composition of various fatty acids in the opposite direction of dietary glucose. In particular, the levels of two ω-6 polyunsaturated fatty acids (PUFAs), linoleic acid and arachidonic acid, were increased by knockdown of lpin-1 but decreased by glucose feeding. Importantly, these ω-6 PUFAs attenuated the short lifespan of glucose-fed lpin-1-inhibited animals. Thus, the production of ω-6 PUFAs is crucial for protecting animals from living very short under glucose-rich conditions.

MDT-15/MED15 permits longevity at low temperature via enhancing lipidostasis and proteostasis.

Low temperatures delay aging and promote longevity in many organisms. However, the metabolic and homeostatic aspects of low-temperature-induced longevity remain poorly understood. Here, we show that lipid homeostasis regulated by Caenorhabditis elegans Mediator 15 (MDT-15 or MED15), a transcriptional coregulator, is essential for low-temperature-induced longevity and proteostasis. We find that inhibition of mdt-15 prevents animals from living long at low temperatures. We show that MDT-15 up-regulates fat-7, a fatty acid desaturase that converts saturated fatty acids (SFAs) to unsaturated fatty acids (UFAs), at low temperatures. We then demonstrate that maintaining a high UFA/SFA ratio is essential for proteostasis at low temperatures. We show that dietary supplementation with a monounsaturated fatty acid, oleic acid (OA), substantially mitigates the short life span and proteotoxicity in mdt-15(-) animals at low temperatures. Thus, lipidostasis regulated by MDT-15 appears to be a limiting factor for proteostasis and longevity at low temperatures. Our findings highlight the crucial roles of lipid regulation in maintaining normal organismal physiology under different environmental conditions.

Necrotising fasciitis in the North East of Scotland: a 10-year retrospective review.

INTRODUCTION: Necrotising fasciitis is a life-threatening rapidly progressing bacterial infection of the skin requiring prompt diagnosis and treatment. Optimum care warrants a combination of surgical debridement, antibiotics and intensive care support. All cases of necrotising fasciitis in 10 years in the North East of Scotland were reviewed to investigate and improve patient care. METHODS: Cases between August 2006 and February 2016 were reviewed using case notes and electronic hospital records. Data including mode of admission, clinical observations, investigations, operative interventions, microbiological and clinical outcomes was collected and reviewed. Analysis required multidisciplinary input including microbiology, infectious disease, trauma and orthopaedics, plastic surgery and intensive care teams. RESULTS: A total of 36 cases were identified. The mean laboratory risk indicator for necrotising fasciitis (LRINEC) score was 7 and 86% of patients fulfilled the criteria for necrotising fasciitis. Patients were commonly haemodynamically stable upon admission but deteriorated rapidly; 36% of patients had a temperature of over 37.5 degrees C on initial observations; 29/36 patients were discharged, 6 patients died acutely (acute mortality rate of 17%); 18/31 of cases were polymicrobial with Streptococcus pyogenes, the common organism. Six amputations or disarticulations were performed from a total of 82 operations in this group, with radical debridement the usual primary operation. The mean time to theatre was 3.54 hours. Highly elevated admission respiratory rate (50 breaths/minute) was associated with increased mortality. CONCLUSIONS: Necrotising fasciitis presents subtly and carries significant morbidity and mortality. A high index of suspicion allows early diagnosis and intervention. We believe that a pan-specialty approach is the cornerstone for good outcomes.

KIN-4/MAST kinase promotes PTEN-mediated longevity of Caenorhabditis elegans via binding through a PDZ domain.

PDZ domain-containing proteins (PDZ proteins) act as scaffolds for protein-protein interactions and are crucial for a variety of signal transduction processes. However, the role of PDZ proteins in organismal lifespan and aging remains poorly understood. Here, we demonstrate that KIN-4, a PDZ domain-containing microtubule-associated serine-threonine (MAST) protein kinase, is a key longevity factor acting through binding PTEN phosphatase in Caenorhabditis elegans. Through a targeted genetic screen for PDZ proteins, we find that kin-4 is required for the long lifespan of daf-2/insulin/IGF-1 receptor mutants. We then show that neurons are crucial tissues for the longevity-promoting role of kin-4. We find that the PDZ domain of KIN-4 binds PTEN, a key factor for the longevity of daf-2 mutants. Moreover, the interaction between KIN-4 and PTEN is essential for the extended lifespan of daf-2 mutants. As many aspects of lifespan regulation in C. elegans are evolutionarily conserved, MAST family kinases may regulate aging and/or age-related diseases in mammals through their interaction with PTEN.

Prefoldin 6 mediates longevity response from heat shock factor 1 to FOXO in C. elegans.

Heat shock factor 1 (HSF-1) and forkhead box O (FOXO) are key transcription factors that protect cells from various stresses. In Caenorhabditis elegans, HSF-1 and FOXO together promote a long life span when insulin/IGF-1 signaling (IIS) is reduced. However, it remains poorly understood how HSF-1 and FOXO cooperate to confer IIS-mediated longevity. Here, we show that prefoldin 6 (PFD-6), a component of the molecular chaperone prefoldin-like complex, relays longevity response from HSF-1 to FOXO under reduced IIS. We found that PFD-6 was specifically required for reduced IIS-mediated longevity by acting in the intestine and hypodermis. We showed that HSF-1 increased the levels of PFD-6 proteins, which in turn directly bound FOXO and enhanced its transcriptional activity. Our work suggests that the prefoldin-like chaperone complex mediates longevity response from HSF-1 to FOXO to increase the life span in animals with reduced IIS.

eIF2A, an initiator tRNA carrier refractory to eIF2α kinases, functions synergistically with eIF5B.

The initiator tRNA (Met-tRNA i Met ) at the P site of the small ribosomal subunit plays an important role in the recognition of an mRNA start codon. In bacteria, the initiator tRNA carrier, IF2, facilitates the positioning of Met-tRNA i Met on the small ribosomal subunit. Eukarya contain the Met-tRNA i Met carrier, eIF2 (unrelated to IF2), whose carrier activity is inhibited under stress conditions by the phosphorylation of its α-subunit by stress-activated eIF2α kinases. The stress-resistant initiator tRNA carrier, eIF2A, was recently uncovered and shown to load Met-tRNA i Met on the 40S ribosomal subunit associated with a stress-resistant mRNA under stress conditions. Here, we report that eIF2A interacts and functionally cooperates with eIF5B (a homolog of IF2), and we describe the functional domains of eIF2A that are required for its binding of Met-tRNA i Met , eIF5B, and a stress-resistant mRNA. The results indicate that the eukaryotic eIF5B-eIF2A complex functionally mimics the bacterial IF2 containing ribosome-, GTP-, and initiator tRNA-binding domains in a single polypeptide.

RNAi targeting Caenorhabditis elegans α-arrestins has little effect on lifespan.

Background: α-arrestins are a family of proteins that are implicated in multiple biological processes, including metabolism and receptor desensitization. Methods: Here, we sought to examine the roles of α-arrestins in the longevity of Caenorhabditis elegans through an RNA interference screen. Results: We found that feeding worms with bacteria expressing double-stranded RNA against each of 24 out of total 29 C. elegans α-arrestins had little effect on lifespan. Thus, individual C. elegans α-arrestins may have minor effects on longevity. Conclusions: This study will provide useful information for future research on the functional role of α-arrestins in aging and longevity.

RNA surveillance via nonsense-mediated mRNA decay is crucial for longevity in daf-2/insulin/IGF-1 mutant C. elegans.

Long-lived organisms often feature more stringent protein and DNA quality control. However, whether RNA quality control mechanisms, such as nonsense-mediated mRNA decay (NMD), which degrades both abnormal as well as some normal transcripts, have a role in organismal aging remains unexplored. Here we show that NMD mediates longevity in C. elegans strains with mutations in daf-2/insulin/insulin-like growth factor 1 receptor. We find that daf-2 mutants display enhanced NMD activity and reduced levels of potentially aberrant transcripts. NMD components, including smg-2/UPF1, are required to achieve the longevity of several long-lived mutants, including daf-2 mutant worms. NMD in the nervous system of the animals is particularly important for RNA quality control to promote longevity. Furthermore, we find that downregulation of yars-2/tyrosyl-tRNA synthetase, an NMD target transcript, by daf-2 mutations contributes to longevity. We propose that NMD-mediated RNA surveillance is a crucial quality control process that contributes to longevity conferred by daf-2 mutations.

Heat FLiPs a Hormonal Switch for Longevity.

Temperature-sensing neurons in C. elegans reduce the life-shortening effects of high temperatures via steroid signaling. In this issue of Developmental Cell, Chen et al. (2016) elucidate the underlying mechanisms by which the transcription factor CREB induces the neuropeptide FLP-6 in the temperature-sensing neurons to counteract the life-shortening effects of high temperature.

Efficacy and safety of teneligliptin, a dipeptidyl peptidase-4 inhibitor, combined with metformin in Korean patients with type 2 diabetes mellitus: a 16-week, randomized, double-blind, placebo-controlled phase III trial.

The aim of the present study was to assess the efficacy and safety of teneligliptin in combination with metformin in Korean patients with type 2 diabetes mellitus who were inadequately controlled with metformin monotherapy. Patients [glycated haemoglobin (HbA1c) 7.0-10.0%, on stable metformin ≥1000 mg/day] were randomized 2 : 1 to receive 20 mg teneligliptin plus metformin (n = 136) or placebo plus metformin (n = 68). The primary endpoint was the change in HbA1c levels from baseline to week 16. The mean baseline HbA1c was 7.9% in the teneligliptin group and 7.8% in the placebo group. The differences between the teneligliptin and placebo groups regarding changes in HbA1c and fasting plasma glucose levels were -0.78 % and -1.24 mmol/l (22.42 mg/dl), respectively, at week 16. The incidence of adverse events was similar between the groups. The addition of teneligliptin once daily to metformin was effective and generally well tolerated in Korean patients with type 2 diabetes.

{Beta}2-adrenergic receptor agonists inhibit the proliferation of 1321N1 astrocytoma cells.

Astrocytomas and glioblastomas have been particularly difficult to treat and refractory to chemotherapy. However, significant evidence has been presented that demonstrates a decrease in astrocytoma cell proliferation subsequent to an increase in cAMP levels. The 1321N1 astrocytoma cell line, as well as other astrocytomas and glioblastomas, expresses ß(2)-adrenergic receptors (ß(2)-ARs) that are coupled to G(s) activation and consequent cAMP production. Experiments were conducted to determine whether the ß(2)-AR agonist (R,R')-fenoterol and other ß(2)-AR agonists could attenuate mitogenesis and, if so, by what mechanism. Receptor binding studies were conducted to characterize ß(2)-AR found in 1321N1 and U118 cell membranes. In addition, cells were incubated with (R,R')-fenoterol and analogs to determine their ability to stimulate intracellular cAMP accumulation and inhibit [(3)H]thymidine incorporation into the cells. 1321N1 cells contain significant levels of ß(2)-AR as determined by receptor binding. (R,R')-fenoterol and other ß(2)-AR agonists, as well as forskolin, stimulated cAMP accumulation in a dose-dependent manner. Accumulation of cAMP induced a decrease in [(3)H]thymidine incorporation. There was a correlation between concentration required to stimulate cAMP accumulation and inhibit [(3)H]thymidine incorporation. U118 cells have a reduced number of ß(2)-ARs and a concomitant reduction in the ability of ß(2)-AR agonists to inhibit cell proliferation. These studies demonstrate the efficacy of ß(2)-AR agonists for inhibition of growth of the astrocytoma cell lines. Because a significant portion of brain tumors contain ß(2)-ARs to a greater extent than whole brain, (R,R')-fenoterol, or some analog, may be useful in the treatment of brain tumors after biopsy to determine ß(2)-AR expression.

Osteocyte apoptosis and control of bone resorption following ovariectomy in mice.

INTRODUCTION: Osteocyte apoptosis has been linked to bone resorption resulting from estrogen depletion and other resorptive stimuli; however, precise spatial and temporal relationships between the two events have not been clearly established. The purpose of this study was to characterize the patterns of osteocyte apoptosis in relation to bone resorption following ovariectomy to test whether osteocyte apoptosis occurs preferentially in areas known to activate resorption. Moreover, we report that osteocyte apoptosis is necessary to initiate endocortical remodeling in response to estrogen withdrawal. MATERIALS AND METHODS: Adult female C57BL/6J mice (17 weeks old) underwent either bilateral ovariectomy (OVX), or sham surgery (SHAM) and were euthanized on days 3, 7, 14, or 21 days after OVX. Diaphyseal cross-sections were stained by immunohistochemistry for activated caspase-3 as a marker of apoptosis. The percentages of caspase-positive stained osteocytes (Casp+Ot.) were measured along major and minor anatomical axes around the femoral diaphysis to evaluate the distribution of osteocyte apoptosis after estrogen loss; resorption surface was measured at the adjacent endocortical regions. In a second study to test whether osteocyte apoptosis plays a regulatory role in the initiation of bone resorption, a group of OVX mice received the pan-caspase inhibitor, QVDOPh, to inhibit osteocyte apoptosis. Remaining experimental and sham groups received either QVD or Vehicle. RESULTS: OVX increased osteocyte apoptosis in a non-uniform distribution throughout the femoral diaphyses. Increases in Casp+osteocytes were predominantly located in the posterior diaphyseal cortex. Here, the number of apoptotic osteocytes 4- to 7-fold higher than sham controls (p<0.005) by day 3 post-OVX and remained elevated. Increases in resorption post-OVX also occurred along the posterior endocortical surface overlying the region of osteocyte apoptosis, but these increases occurred only at 14 and 21 days post-OVX (p<0.002) well after the increases in osteocyte apoptosis. Treatment with QVD in OVX animals suppressed osteocyte apoptosis, with levels in QVD-treated samples equivalent to baseline. Moreover, the increases in osteoclastic resorption normally observed after estrogen loss did not occur in OVX mice treated with QVD. CONCLUSIONS: The results of this study demonstrate that osteocyte apoptosis following estrogen loss occur regionally, rather than uniformly throughout the cortex. We also showed that estrogen loss increased osteocyte apoptosis. Apoptotic osteocytes were overwhelmingly localized within the posterior cortical region, the location where endocortical resorption was subsequently activated in ovariectomized mice. Finally, the increases in osteoclastic resorption normally observed after estrogen withdrawal did not occur in the absence of osteocyte apoptosis indicating that this apoptosis is necessary to activate endocortical remodeling following estrogen loss.