Publications by authors named "Houck W"

Here we realize the first reported integrated photonic devices fabricated using sputtered niobium-tantalum oxide films. Sputtered niobium-tantalum oxide films are highly promising for integrated photonics as they are scalable to high volume manufacturing, possess high refractive index, and are transparent in the ultraviolet through near infrared wavelength range. At a wavelength near 1550 nm, we observe propagation losses as low as 0.

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Objectives: Minimally invasive endoscopic treatment of emphysema could provide palliation with less risk than lung volume reduction surgery and offer therapy to patients currently not considered for lung volume reduction surgery. The Intrabronchial Valve is used to block bronchial airflow in the most emphysematous areas of lung.

Methods: Patients with severe chronic obstructive pulmonary disease and heterogeneous upper lobe-predominant emphysema were eligible.

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Although modern techniques in anesthesia and surgery have reduced morbidity and mortality for pulmonary resection, some physicians still consider advanced age a contraindication to resection of lung cancer. We examined our experience with VATS lobectomy in octogenarians at Cedars-Sinai Medical Center over 12 years (1992-2004). There were 159 patients.

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Background: Although many video-assisted thoracic surgery (VATS) lobectomies have been performed over the 12 years since the first VATS lobectomy, controversies about the procedure remain regarding the safety and associated morbidity and mortality of that procedure. This series is reviewed to assess these issues.

Methods: Between 1992 and 2004, we performed 1,100 VATS lobectomies in 595 women (54.

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Purpose Of Review: The momentum for minimally invasive thoracic surgery has been growing. Thousands of video-assisted thoracoscopic surgery lobectomies have been performed since the first video-assisted thoracoscopic surgery lobectomy was performed in 1992, but currently most lobectomies are still performed via a thoracotomy. Although most lobectomies could be performed with video-assisted thoracoscopic surgery, less than 5% are currently performed that way.

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Swyer-James (MacLeod) syndrome is an acquired form of unilateral hyperlucency of the lung and is characterized by the development of severe emphysema, bronchiectasis, and/or bronchiolitis obliterans. It may develop as a complication of repeated episodes of pulmonary infection resulting in bronchiolitis obliterans and obstruction of small airways. Most patients with Swyer-James (MacLeod) syndrome can be managed clinically, and the pathologic features of the syndrome have been described in only a few reports.

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3-oxo-Delta5-steroid isomerase (ketosteroid isomerase, KSI) catalyzes the isomerization of 5-androstene-3,17-dione (1) to 4-androstene-3,17-dione (3) via a dienolate intermediate (2-). KSI catalyzes this conversion about 13 orders of magnitude faster than the corresponding reaction catalyzed by acetate ion, a difference in activation energy (DeltaG) of approximately 18 kcal/mol. To evaluate whether the decrease in DeltaG by KSI is due to enthalpic or entropic effects, the activation parameters for the isomerization of 1 catalyzed by the D38E mutant of KSI were determined.

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Resection of the left upper lobe with preservation of the lingula is the anatomic equivalent of a right upper lobectomy with preservation of the right middle lobe. Therefore, our standard operation for a small apical tumor in the left upper lobe has been an apical trisegmentectomy. The purpose of this article is to review our experience with the procedure by video-assisted thoracic surgery (VATS) and to describe the operative technique for a VATS apical trisegmentectomy.

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Background: Pulmonary nodules are frequently first diagnosed by frozen section, immediately followed by lobectomy or other procedures. The frozen section diagnosis of pulmonary nodules can be difficult, as inflammatory and fibrotic lesions can be confused for malignancy, creating intraoperative dilemmas for pathologists and thoracic surgeons.

Methods: We reviewed our experience at Cedars-Sinai Medical Center with the frozen section diagnoses of 183 consecutive pulmonary nodules smaller than 1.

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Purpose: To quantify the risk of secondary leukemias in relapsed testicular cancer patients undergoing autologous stem-cell transplantation with high-dose etoposide.

Patients And Methods: Single institution, retrospective study of germ cell tumor patients who underwent autologous transplantation using high-dose etoposide from 1987 to 2001.

Results: One hundred thirteen patients received high-dose etoposide and carboplatin followed by autologous stem-cell transplantations for germ cell tumors.

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Both acetic acid and acetate catalyze the isomerization of 5-androstene-3,17-dione (1) to its conjugated isomer, 4-androstene-3,17-dione (3), through a dienol(ate) intermediate. The temperature dependence of the overall isomerization rate constants and of the microscopic rate constants for this isomerization was determined, and the Arrhenius plots give the activation enthalpy and entropy for each step. The source of the activation energy for the overall isomerization and for each of the individual steps is predominantly enthalpic, with a moderate to low entropic penalty.

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We present a case of an 88-year-old man who presented with chest pain and shortness of breath. Chest radiography suggested the presence of a ruptured diaphragm, and on exploration a left Bochdalek defect with herniation of stomach and small bowel into the left pleural cavity was found. This was repaired and the patient eventually was discharged to a nursing facility.

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Benign metastasizing leiomyoma is a rare clinical entity that has been described in several previous reports. Although the exact pathophysiology of the disease is unknown, two predominant theories exist: (1) metastasis from an existing leiomyoma (commonly seen with uterine leiomyoma) or (2) multicentric leiomyomatous growths rather than actual metastases. We present an interesting case in which several elements of the patient's history complicated the differential diagnosis.

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Background: Many physicians have inadequate physical diagnosis skills and cannot detect thyroid abnormalities on physical examination.

Purpose: To evaluate a multimodality intervention to improve thyroid examination skills using a prospective controlled trial in first-year residents enrolled in an academic internal medicine program.

Methods: The intervention group received a 60-minute educational session during which an endocrinologist described anatomical landmarks, thyroid abnormalities, and examination techniques using a slide show, computerized animation, videotape, and live demonstration on a volunteer with goiter.

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Objective: Congestive heart failure (CHF) is associated with left ventricular (LV) failure, neurohormonal system activation, and diminished exercise capacity. Although alterations in systemic vascular resistive properties have been recognized to occur with CHF, whether and to what degree perfusion abnormalities occur within the brain after the development of CHF remain poorly understood. Accordingly, the present study measured brain blood flow patterns in pigs after the development of pacing-induced CHF at rest and after treadmill-induced exercise.

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Background: Release of growth hormone (GH), putatively through alterations in insulin growth factor-1 (IGF-1) levels, has been implicated to influence left ventricular (LV) myocardial structure and function. The objective of this study was to determine contributory mechanisms by which GH supplementation may influence LV function with the development of congestive heart failure (CHF).

Methods And Results: Pigs were assigned to the following groups: (1) chronic pacing at 240 bpm for 3 weeks (n = 10), (2) chronic pacing and GH supplementation (200 microg x kg(-1) x d(-1), n = 10), and (3) controls (n = 8).

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This study examined the acute effects of amlodipine treatment on left ventricular pump function, systemic hemodynamics, neurohormonal status, and regional blood flow distribution in an animal model of congestive heart failure (CHF), both at rest and with treadmill exercise. A total of 14 pigs were studied under control conditions and after the development of pacing-induced CHF (240 beats per minute, 3 weeks, n = 7) or with CHF and acute amlodipine treatment for the last 3 days of pacing (1.5 mg/kg per day, n = 7).

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The development of congestive heart failure (CHF) is associated with left ventricle (LV) dilation and myocardial remodeling. The matrix metalloproteinases (MMPs) play a significant role in extracellular remodeling, and recent studies have demonstrated increased MMP expression and activity with CHF. Whether increased MMP activity directly contributes to the LV remodeling with CHF remains unknown.

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Background: AT1 angiotensin II (AT1 Ang II) receptor activation has been shown to cause increased vascular resistance in the systemic (SVR), pulmonary (PVR), and coronary vasculature which may be of particular importance in the setting of congestive heart failure (CHF). The overall goal of this study was to examine the effects of acute AT1 Ang II receptor inhibition on left ventricular (LV) pump function, systemic hemodynamics, and regional blood flow patterns in the normal state and with CHF, both at rest and with treadmill-induced exercise.

Methods And Results: Pigs (25 kg) were instrumented to measure cardiac output (CO), SVR, and PVR, and LV myocardial blood flow distribution in the conscious state and were assigned to one of two groups: (1) pacing-induced CHF (240 bpm for 3 weeks, n = 6) or (2) sham controls (n = 5).

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Background: Pretreatment with potassium channel openers (PCOs) has been shown to provide protective effects in the setting of myocardial ischemia. The goal of the present study was to examine whether PCO pretreatment would provide protective effects on left ventricular (LV) and myocyte function after cardioplegic arrest.

Methods And Results: The first study quantified the effects of PCO pretreatment on LV myocyte contractility after simulated cardioplegic arrest.

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Background: This study examined the effects of chronic amlodipine treatment on left ventricular (LV) pump function, systemic hemodynamics, neurohormonal status, and regional blood flow distribution in an animal model of congestive heart failure (CHF) both at rest and with treadmill exercise. In an additional series of in vitro studies, LV myocyte contractile function was examined.

Methods And Results: Sixteen pigs were studied under normal control conditions and after the development of chronic pacing-induced CHF (240 bpm, 3 weeks, n=8) or chronic pacing and amlodipine (1.

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Background: AT1 receptor activation has been demonstrated to cause increased vascular resistance properties which may be of particular importance in the setting of congestive heart failure (CHF). The overall goal of this study was to examine the effects of ACE inhibition (ACEI) alone, AT1 receptor blockade alone and combined ACEI and AT1 receptor blockade on LV pump function, systemic hemodynamics and regional blood flow patterns in the normal state and with the development of pacing induced CHF, both at rest and with treadmill induced exercise.

Methods And Results: Pigs (25 kg) were instrumented in order to measure cardiac output (CO), systemic (SVR) and pulmonary vascular (PVR) resistance, neurohormonal system activity, and myocardial blood flow distribution in the conscious state and assigned to one of 4 groups: (1) rapid atrial pacing (240 bpm) for 3 weeks (n = 7); (2) ACEI (benazeprilat, 3.

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Background: This study was designed to determine the effects of prolonged hyperkalemic cardioplegic arrest under normothermic or hypothermic conditions with respect to left ventricular myocyte contractile performance and beta-adrenergic responsiveness.

Methods: Isolated left ventricular porcine myocytes were randomly assigned to one of three groups: (group 1) normothermic control, (group 2) hypothermic cardioplegic arrest, or (group 3) normothermic cardioplegic arrest. Myocyte contractility was evaluated by high-speed video microscopy at baseline and after beta-adrenergic stimulation with isoproterenol (25 nmol/L).

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