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Lung ultrasonography derived B-line scores as predictors of left ventricular end-diastolic pressure and pulmonary artery wedge pressure. Respir Med 2023; 219:107415. [PMID: 37741582 DOI: 10.1016/j.rmed.2023.107415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 08/30/2023] [Accepted: 09/17/2023] [Indexed: 09/25/2023]
Abstract
BACKGROUND Non-invasive assessment of elevated left ventricular end-diastolic pressure (LVEDP) and pulmonary artery wedge pressure (PAWP) in patients with heart diseases is challenging. Lung ultrasonography (LUS) is a promising modality for predicting LVEDP and PAWP. METHODS Fifty-seven stable ambulatory patients who underwent right and left heart catheterization were included. Following the procedures, LUS was performed in twenty-eight ultrasonographic zones, and the correlation between five different LUS derived B-line scores with LVEDP and PAWP was examined. RESULTS The B-line index correlated with LVEDP and PAWP, with coefficients of 0.45 (p = 0.006) and 0.30 (p = 0.03), respectively. B-line index showed an AUC of 0.76 for identifying LVEDP > 15 mmHg (p = 0.01) and an AUC of 0.73 for identifying PAWP > 15 mmHg (p = 0.008). Overall, scores performances were similar in predicting LVEDP or PAWP > 15 mmHg. A B-line index ≥ 28 was significantly associated with LVEDP > 15 mmHg (OR: 9.97) and PAWP > 15 mmHg (OR: 6.61), adjusted for age and indication for heart catheterization. CONCLUSIONS LUS derived B-line scores are moderately correlated with PAWP and LVEDP in patients with heart diseases. A B-line index ≥ 28 can be used to predict elevated LVEDP and PAWP with high specificity.
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Medical, ethical, and legal aspects of end-of-life dilemmas in the intensive care unit. Cleve Clin J Med 2021; 88:516-527. [PMID: 34470756 DOI: 10.3949/ccjm.88a.14126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Physicians in the intensive care unit face a myriad of ethical dilemmas involving end-of-life care, yet they receive only minimal training about their jurisprudential obligations, and misconceptions about legal responsibilities abound. In particular, significant uncertainty exists among critical care physicians as to ethical and legal obligations for terminally ill patients. This paper presents 3 hypothetical cases to elucidate the medical, ethical, and legal considerations in common end-of-life situations encountered in the intensive care unit.
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Feasibility and safety of the antecubital venous access for right heart catheterization in patients with pulmonary hypertension. Pulm Circ 2020; 10:2045894019875380. [PMID: 32128156 PMCID: PMC7031798 DOI: 10.1177/2045894019875380] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 08/18/2019] [Indexed: 11/15/2022] Open
Abstract
Background The diagnosis of pulmonary arterial hypertension requires right heart catheterization (RHC) which is typically performed via proximal venous access (PVA). Antecubital venous access (AVA) is an alternative approach for RHC that can minimize complications, decrease procedural duration and allow for immediate patient recovery. A direct comparison between the two procedures in patients with pulmonary hypertension (PH) is lacking. Objectives To determine the feasibility, safety, and adoption rates of AVA-RHC as compared with ultrasound-guided PVA in a subpopulation of patients with PH. Methods All patients who underwent RHC for evaluation of PH between December 2014 and March 2017 at a single large academic medical center were included in this study. Demographic, procedural and outcomes data were retrieved from the medical records. Results In total, 159 RHC were included (124 AVA, 35 PVA). The duration of RHC was significantly shorter in the AVA compared with PVA group (53 (IQR 38–70) vs. 80 (IQR 56–95) min, respectively, p < 0.001). 19% of AVA (24/124) procedures were switched to PVA. Failed attempts at AVA were more common in scleroderma (50% failure rate). Success rate of AVA increased from 81.2% to 93.3% from the first to last quartile. Fluoroscopy time was similar in both groups, the difference between the groups in the radiation dose are not statistically significant (54.5 (IQR 25–110) vs. 84.5 (IQR 30–134)). Conclusion AVA-RHC is a feasible and safe alternative to PVA in patients with PH who are evaluated for pulmonary arterial hypertension diagnosis. Our experience and rapid adoption rate support the use of AVA as the preferred access site for RHC in uncomplicated PH patients.
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Abstract
Pulmonary arterial hypertension (PAH) is a common consideration when patients have unexplained signs of cardiopulmonary disease. Guidelines have been issued regarding diagnosis and management of this condition. Since multiple conditions can mimic components of PAH, the clinician should think about the patient's total clinical condition before diagnosing and categorizing it. Proper evaluation and etiologic definition are crucial to providing the appropriate therapy. This review offers a case-based guide to the evaluation of patients with suspected PAH.
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Sampling pleural nodules with an EBUS scope: A novel application. Respir Med Case Rep 2018; 25:36-38. [PMID: 29928584 PMCID: PMC6008285 DOI: 10.1016/j.rmcr.2018.06.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Revised: 06/07/2018] [Accepted: 06/07/2018] [Indexed: 12/30/2022] Open
Abstract
Convex endobronchial ultrasound transbronchial needle aspiration (C-EBUS-TBNA) has become an essential modality for diagnosis and staging of hilar, mediastinal, and central pulmonary lesions. A Trans-thoracic pleural biopsy is the accepted practice for diagnosing pleural nodules. However, the diagnostic yield of a pleural biopsy is limited and surgical procedures pose a greater risk. We report a unique case of using a C- EBUS scope for the diagnosis of pleural nodules and mediastinal lymph node metastasis in a man with metastatic renal cell carcinoma.
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Toxicity risk from glucocorticoids in sarcoidosis patients. Respir Med 2017; 132:9-14. [PMID: 29229111 DOI: 10.1016/j.rmed.2017.09.003] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Revised: 09/06/2017] [Accepted: 09/07/2017] [Indexed: 12/13/2022]
Abstract
BACKGROUND Glucocorticoids (GC) are considered first-line therapy for treating sarcoidosis, but there are few data about the adverse consequences of GC. Although there are several steroid-sparing medications available for treatment, a large proportion of patients are treated with prolonged courses of GC. The toxicities of GC in sarcoidosis populations have not been carefully evaluated. METHODS We performed a retrospective cohort study of all newly diagnosed sarcoidosis patients who had the entirety of their medical care in a single health system. We analyzed the time to development of a composite toxicity end-point, including diabetes, hypertension, weight gain, hyperlipidemia, low bone density and ocular complications of GC using Cox proportional hazards analysis. RESULTS One hundred and five patients were ever treated with GC, whereas 49 were not treated during a median follow-up of 101 months. GC-treated patients developed 1.3 ± 1.1 toxicities during therapy, versus 0.6 ± 1.0 in the non-treated group. After adjustment for age, gender, race and preexisting conditions, the hazard ratio for ever-treated patients was 2.37 (1.34-4.17) for the composite end-point. Age and the presence of preexisting conditions also were associated with reaching the end-point. Similar effects were seen when analyzed for cumulative GC dose and for duration of GC use. For individual end-points, weight gain (HR 2.04) and new hypertension (HR 3.36) were associated with any use of GC. CONCLUSIONS Our data suggest that GC are associated with clinically important toxicities in sarcoidosis patients, associated with both the cumulative dose and duration of treatment.
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Critical illness associated with 2013-2014 influenza A (H1N1): Postpandemic characteristics, presentation and outcomes. Indian J Crit Care Med 2016; 19:636-41. [PMID: 26730113 PMCID: PMC4687171 DOI: 10.4103/0972-5229.169328] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Introduction: The United States experienced a postpandemic outbreak of H1N1 influenza in 2013–2014. Unlike the pandemic in 2009 clinical course and outcomes associated with critical illness in this postpandemic outbreak has been only sparsely described. Methods: We conducted a retrospective analysis of all patients admitted to the Medical Intensive Care Unit with H1N1 influenza infection in 2009–2010 (pandemic) and 2013–2014 (postpandemic). Results: Patients admitted in the postpandemic period were older (55 ± 13 vs. 45 ± 12, P = 0.002), and had a higher incidence of underlying pulmonary (17 vs. 7, P = 0.0007) and cardiac (16 vs. 8, P = 0.005) disease. Mechanical ventilation was initiated in most patients in both groups (27 vs. 21, P = 1.00). The PaO2/FiO2 ratio was significantly higher in the pandemic group on days 1 (216 vs. 81, P = 0.0009), 3 (202 ± 99 vs. 100 ± 46, P = 0.002) and 7 (199 ± 103 vs. 113 ± 44, P = 0.019) but by day 14 no difference was seen between the groups. Rescue therapies were used in more patients in the postpandemic period (48% vs. 20%, P = 0.028), including more frequent use of prone ventilation (10 vs. 3, P = 0.015), inhaled vasodilator therapy (11 vs. 4, P = 0.015) and extracorporeal membrane oxygenation (ECMO) (4 vs. 2, P = NS). No significant differences in mortality were seen between the two cohorts. Conclusions: Compared to the 2009–2010 pandemic, the 2013–2014 H1N1 strain affected older patients with more underlying co-morbid cardio-pulmonary diseases. The patients had worse oxygenation indices and rescue modalities such as prone ventilation, inhaled epoprostenol and ECMO, were used more consistently as compared to the 2009 pandemic.
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Glucocorticoid Toxicity Is Common in Sarcoidosis. Chest 2015. [DOI: 10.1378/chest.2267014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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Yellow nail syndrome: a case report and review of treatment options. CLINICAL RESPIRATORY JOURNAL 2015; 11:405-410. [PMID: 26257383 DOI: 10.1111/crj.12354] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2015] [Revised: 06/23/2015] [Accepted: 08/03/2015] [Indexed: 12/19/2022]
Abstract
BACKGROUND AND AIMS Yellow nail syndrome is a rare disorder involving characteristic nail changes, lymphedema and chronic respiratory symptoms. Currently there is no definitive treatment and there have been no prospective randomised controlled trials evaluating the available options. In order to strengthen the literature on this topic, we present the case of a 67-year-old man with YNS and a detailed review of current treatment options. METHODS We included 40 articles for the final review according to their relevance with the subject. RESULTS Data for use of the commonly chosen therapies for YNS remains inconclusive, with small studies and case reports showing mixed results of efficacy. CONCLUSION Although the date indicates that it is reasonable to recommend a trial of conservative therapy including vitamin E, antibiotics and compression stockings before pursuing more aggressive or invasive modalities, larger scale studies are required to determine the true efficacy of all treatment options.
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All the Bubbles “Are-Gone”: An Unusual Cause of Stroke Post Argon Plasma Coagulation in a Patient With Hereditary Hemorrhagic Telangiectasia (HHT). Chest 2014. [DOI: 10.1378/chest.1991474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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Neighbors Behaving Badly: An Unusual Case of Myocardial Infarction in a Patient With Severe Pulmonary Hypertension. Chest 2014. [DOI: 10.1378/chest.1991460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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Cumulative Dose and Duration of Glucocorticoid Use Are Associated With Metabolic Disorders in Sarcoidosis Patients. Chest 2014. [DOI: 10.1378/chest.1993329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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A Disheartening Bleed: An Uncommon Cause of Massive Gastrointestinal Hemorrhage. Chest 2014. [DOI: 10.1378/chest.1991429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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Postangioedema attack skin blisters: an unusual presentation of hereditary angioedema. BMJ Case Rep 2014; 2014:bcr-2013-201482. [PMID: 24722707 DOI: 10.1136/bcr-2013-201482] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Hereditary angioedema (HAE) is an autosomal dominant disorder characterised by attacks of self-limited swelling affecting extremities, face and intra-abdominal organs, most often caused by mutations in the C1-inhibitor gene with secondary Bradykinin-mediated increased vascular permeability. We describe a 36-year-old man with a history of HAE who presented with painful interdigital bullae secondary to an acute oedema exacerbation. Biopsy and cultures of the lesions were negative and they resolved spontaneously. It is important to highlight and recognise the development of oedema blisters after resolution of a flare of HAE (only 1 previous case report), and hence avoid unnecessary dermatological diagnostic workup and treatment.
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Restricting the Diagnosis: Right Ventricular Failure Three Years After Bilateral Lung Transplant. Chest 2013. [DOI: 10.1378/chest.1702999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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Geographic Distribution of Patients in the Medical Intensive Care Unit (MICU): A Low-Cost Strategic Organizational Initiative to Improve Communication, Education, and Employee Satisfaction. Chest 2013. [DOI: 10.1378/chest.1703515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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An Uncommon Presentation of Lymphocytic-Variant Hypereosinophilic Syndrome as the Cause of Respiratory Failure in a Patient With Asthma. Chest 2013. [DOI: 10.1378/chest.1703011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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Abstract
The need to provide invasive mechanical ventilatory support to patients with myocardial infarction and acute left heart failure is common. Despite the large number of patients requiring mechanical ventilation in this setting, there are remarkably few data addressing the ideal mode of respiratory support in such patients. Although there is near universal acceptance regarding the use of non-invasive positive pressure ventilation in patients with acute pulmonary oedema, there is more concern with invasive positive pressure ventilation owing to its more significant haemodynamic impact. Positive end-expiratory pressure (PEEP) is almost universally applied in mechanically ventilated patients due to benefits in gas exchange, recruitment of alveolar units, counterbalance of hydrostatic forces leading to pulmonary oedema and maintenance of airway patency. The limited available clinical data suggest that a moderate level of PEEP is safe to use in severe left ventricular (LV) dysfunction and cardiogenic shock, and may provide haemodynamic benefits as well in LV failure which exhibits afterload-sensitive physiology.
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Relative cost and outcomes in the intensive care unit of acute lung injury (ALI) due to pandemic influenza compared with other etiologies: a single-center study. Ann Intensive Care 2012; 2:41. [PMID: 22929215 PMCID: PMC3503790 DOI: 10.1186/2110-5820-2-41] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Accepted: 07/30/2012] [Indexed: 11/19/2022] Open
Abstract
Background Critical illness due to 2009 H1N1 influenza has been characterized by respiratory complications, including acute lung injury (ALI) or acute respiratory distress syndrome (ARDS), and associated with high mortality. We studied the severity, outcomes, and hospital charges of patients with ALI/ARDS secondary to pandemic influenza A infection compared with ALI and ARDS from other etiologies. Methods A retrospective review was conducted that included patients admitted to the Cleveland Clinic MICU with ALI/ARDS and confirmed influenza A infection, and all patients admitted with ALI/ARDS from any other etiology from September 2009 to March 2010. An itemized list of individual hospital charges was obtained for each patient from the hospital billing office and organized by billing code into a database. Continuous data that were normally distributed are presented as the mean ± SD and were analyzed by the Student’s t test. The chi-square and Fisher exact tests were used to evaluate differences in proportions between patient subgroups. Data that were not normally distributed were compared with the Wilcoxon rank-sum test. Results Forty-five patients were studied: 23 in the H1N1 group and 22 in the noninfluenza group. Mean ± SD age was similar (44 ± 13 and 51 ± 17 years, respectively, p = 0.15). H1N1 patients had lower APACHE III scores (66 ± 20 vs. 89 ± 32, p = 0.015) and had higher Pplat and PEEP on days 1, 3, and 14. Hospital and ICU length of stay and duration of mechanical ventilation were comparable. SOFA scores over the first 2 weeks in the ICU indicate more severe organ failure in the noninfluenza group (p = 0.017). Hospital mortality was significantly higher in the noninfluenza group (77 vs. 39%, p = 0.016). The noninfluenza group tended to have higher overall charges, including significantly higher cost of blood products in the ICU. Conclusions ALI/ARDS secondary to pandemic influenza infection is associated with more severe respiratory compromise but has lower overall acuity and better survival rates than ALI/ARDS due to other causes. Higher absolute charges in the noninfluenza group are likely due to underlying comorbid medical conditions.
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Finding the cause of acute kidney injury: Which index of fractional excretion is better? Cleve Clin J Med 2012; 79:121-6. [DOI: 10.3949/ccjm.79a.11030] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Evaluation of pediatric patients with mild-to-moderate hypertension: yield of diagnostic testing. Pediatrics 2008; 122:e988-93. [PMID: 18977966 DOI: 10.1542/peds.2008-0365] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE Children and adolescents with newly diagnosed hypertension undergo various tests to define the cause and target organ consequences of the elevated blood pressure. We tested the hypothesis that the diagnostic yield of individual components of the currently recommended assessment does not justify performance for all patients with mild-to-moderate hypertension. METHODS A retrospective chart review was conducted of patients who were referred between July 2002 and June 2007 for mild-to-moderate hypertension, defined as maximum blood pressure at >or=95% + 20/10 mmHg. The assessment included history and physical examination, nutritional assessment, urinalysis, biochemical and fasting lipid profile, renal ultrasound, echocardiogram, and 24-hour ambulatory blood pressure monitoring. RESULTS A total of 249 patients were identified, and charts for 220 (88%) were available for review. There were 156 boys and 64 girls aged 13.3 +/- 4.4 years. BMI was 26.1 +/- 6.7 kg/m(2), and 143 (65%) had a BMI of >or=90%. Results of urinalysis and serum biochemical testing were clinically normal in all cases. Among those with a lipid profile, 59 (42%) had total cholesterol values of >170 mg/dL, and 26 (19%) had severe hypercholesterolemia (>200 mg/dL). Renal sonography revealed findings plausibly associated with hypertension in 14 (8%) patients; 4 (2%) had renovascular abnormalities. Yield of echocardiography was 17%. On ambulatory blood pressure monitoring, 47 (60%) children had systolic readings of >95% at least 20% of the time, and 28 (36%) had diastolic readings of >95% at least 20% of the time. CONCLUSIONS For children and adolescents with mild-to-moderate hypertension, on the basis of a cutoff of 5% to 20% abnormal results to define a useful test, the initial evaluation can range from a serum cholesterol level and ambulatory blood pressure monitoring to a panel that consists of a fasting lipid profile, renal ultrasound, echocardiogram, and ambulatory blood pressure monitoring. Additional assessment should be guided by specific clinical features and the nature of the patient population.
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Urolithiasis in pediatric patients: a single center study of incidence, clinical presentation and outcome. J Urol 2007; 177:2300-5. [PMID: 17509344 DOI: 10.1016/j.juro.2007.02.002] [Citation(s) in RCA: 208] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2006] [Indexed: 11/16/2022]
Abstract
PURPOSE The incidence of kidney stones in adults has increased in the last 30 years. This retrospective, single site review was done to test the hypotheses that the incidence of urolithiasis in pediatric patients increased from 1994 to 2005, and that metabolic abnormalities were more common in patients with renal stones in the final 3 years of the study period. MATERIALS AND METHODS Charts from 2 time periods were reviewed, 1994 to 1996 (period 1) and 2003 to 2005 (period 2). Clinical and laboratory data, including demographics, presenting complaints, laboratory assessment, treatment and outcome, were tabulated in patients with confirmed urolithiasis. RESULTS The number of patients with urolithiasis increased from 7 in period 1 to 61 in period 2. When expressed as cases per 100 new patients the incidence increased 4.6 times (p = 0.014). Focusing on period 2, 28% of patients were younger than 10 years. While blood tests were generally normal, 76% of patients had at least 1 abnormality in the 24-hour urine collection. Hypocitraturia, which was the most common metabolic abnormality, was noted in 52% of patients. The small number of patients in period 1 precluded determination as to whether metabolic abnormalities were more common in period 2. Surgery and/or lithotripsy was required in 12 children. Stone disease recurred in 39% of the patients. CONCLUSIONS The incidence of urolithiasis in the pediatric population increased nearly 5-fold at our institution during the last decade. We recommend that the primary diagnostic test be a 24-hour urine collection. The most common metabolic abnormality was hypocitraturia, followed by hypercalciuria. Recurrence of stones is common (approximately 40% rate) and followup is advised.
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Abstract
Stimulation of the epidermal growth factor receptor (EGF-R) produces numerous effects on central nervous system (CNS) cells in vitro including neuronal survival and differentiation, astrocyte proliferation and the proliferation of multipotent progenitors. However, the in vivo role of EGF-R is less well understood. In the present study, we demonstrate that EGF-R null mice generated on a 129Sv/J Swiss Black background undergo focal but massive degeneration the olfactory bulb, piriform cortex, neocortex, and thalamus between postnatal days 5 and 8 which is due, at least in part, to apoptosis. Some of the neuronal populations that degenerate do not normally express EGF-R, indicating an indirect mechanism of neuronal death. There were also delays in GFAP expression within the glia limitans and within structures outside the germinal zones in early postnatal ages. At or just prior to the onset of the degeneration, however, there was an increase in GFAP expression in these areas. The brains of EGF-R (-/-) animals were smaller but cytoarchitecturally normal at birth and neuronal populations appeared to be intact, including striatal GABAergic and midbrain dopaminergic neurons which have previously been shown to express EGF-R. Multipotent progenitors and astrocytes derived from EGF-R (-/-) mice were capable of proliferating in response to FGF-2. These data demonstrate that EGF-R expression is critical for the maintenance of large portions of the postnatal mouse forebrain as well as the normal development of astrocytes.
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Induction of HB-EGF mRNA is intact in skin organ cultures of EGFR knockout mice. J Dermatol Sci 1998. [DOI: 10.1016/s0923-1811(98)83916-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Increased phenylalanine incorporation in regenerating skeletal muscle grafts. Can J Physiol Pharmacol 1986; 64:199-205. [PMID: 3516349 DOI: 10.1139/y86-030] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Skeletal muscle regenerates following grafting, but little is known about protein synthesis and its regulation during regeneration. We determined the sequence of changes in protein synthesis in rat extensor digitorum longus (EDL) muscle by the measurement of phenylalanine (Phe) incorporation into muscle protein at various times after grafting. Compared with control EDL, Phe incorporation in grafts doubled in 1 day, was four- to eight-fold greater from days 2 to 10 after grafting, and then subsided. Tissue mass (wet weight) increased rapidly from days 7 to 20 in EDL grafts. The maximal increase in protein synthesis occurred 7-10 days after grafting, whether or not the nerve was left intact. Autoradiography indicated that incorporated radioactivity was associated with regenerating muscle fibers on day 10. Deficiencies of insulin, pituitary or testicular hormones, or chronic in vivo administration of insulin, growth hormone, testosterone, or tri-iodothyronine did not substantially alter the elevation in incorporation of the Phe into muscle protein 10 days after grafting. The breakdown of EDL protein, measured in vitro simultaneously with protein synthesis, was increased five-fold, and overall protein degradation was elevated six-fold 10 days after grafting. These findings indicate that Phe incorporation is rapidly elevated following grafting of the EDL, and that by days 7-10 reflects synthesis in regenerating muscle fibers. The increase in protein synthesis associated with muscle regeneration at this time appears to be independent of innervation and anabolic hormones.
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