Citations

An instrument has been developed to acquire polarized attenuated total internal reflection (ATIR) mid-IR spectra of supported monomolecular films in situ at the lipid/water (L/W) interface. The monolayer film is applied to the treated surface of a trapezoidal germanium crystal as it is immersed into the subphase of a specially designed Langmuir-Blodgett trough. This approach offers several advantages over the study of monolayer films at the air/water (A/W) interface by external reflection techniques, including (1) an improved signal throughput and multiple reflections, both contributing to an improved signal-to-noise (S/N) ratio; (2) versatility with respect to the chemical nature of the surface; and (3) the ability to use standard spectral subtraction methods to compensate for absorption of the aqueous subphase. The enhanced sensitivity of this approach facilitates the study of in situ interactions of peptides with fully hydrated lipid membrane surfaces.

A continuously tuneable, quasi-continuous-wave (cw), ultraviolet source for resonance Raman spectroscopy has been developed. The third and fourth harmonics of a picosecond mode-locked titanium: sapphire laser were generated in nonlinear crystals. The pulses which resulted from these processes were spectrally narrow (10–15 cm −1 ) and had low peak powers (<1 kW), while the system as a whole provides high average powers. Fourth-harmonic wavelengths were generated from 208 to 230 nm with average powers from 15 to 40 mW, while the third harmonic ranged from 255 to 305 nm with over 90 mW of power. The UV light was well collimated and focused well, and the power was stable for hours. Resonance Raman spectra of tryptophan and phenylalanine were recorded to demonstrate the practical application of this system. Spectra with excellent signal-to-noise ratios were recorded in 6 min with no deleterious effects from nonlinear processes. The selective enhancement of tryptophan scattering in a 1:10 molar solution of tryptophan to phenylalanine makes clear the advantage of a continuously tuneable UV source. Elaboration of this system to the full tuning range of titanium: sapphire lasers will create a laser source suitable for resonance Raman spectroscopy throughout the ultraviolet region (205–400 nm).

Abstract Synovial chondromatosis of the shoulder has been treated in the past with an open arthrotomy, removal of loose bodies, and synovectomy. Several authors have described arthroscopy as a means of treating this rare disorder because of the excellent visualization of the glenohumeral joint, decreased morbidity, and early rehabilitation potential. This article offers a technique in which a large‐bore cannula and high pressure and flow are used to facilitate the removal of loose bodies from the joint.

Abstract The field of vascular biology has been stimulated by the concept that circulating endothelial progenitor cells (EPCs) may play a role in neoangiogenesis (postnatal vasculogenesis). One problem for the field has been the difficulty in accurately defining an EPC. Likewise, circulating endothelial cells (CECs) are not well defined. The lack of a detailed understanding of the proliferative potential of EPCs and CECs has contributed to the controversy in identifying these cells and understanding their biology in vitro or in vivo. A novel paradigm using proliferative potential as one defining aspect of EPC biology suggests that a hierarchy of EPCs exists in human blood and blood vessels. The potential implications of this view in relation to current EPC definitions are discussed.

Atherosclerosis represents one of the major causes of premature death in the United States today, and it is frequently associated with, exacerbates, and is aggravated by chronic kidney disease (CKD). Atherosclerosis integrates the response to a number of insults, and consequently, the accelerated atherosclerosis found in CKD patients is associated with activation of a variety of humoral and tissue mechanisms. Hypertension, diabetes, dyslipidemia, obesity, metabolic syndrome, and additional nontraditional risk factors can damage the kidney directly and by promoting intrarenal atherogenesis, even in the absence of obstructive lesions in the renal artery. Evidence indicates that increased oxidative stress and inflammation may mediate a large part of the effects of risk factors on the kidney. In turn, progressive deterioration of renal function in CKD may lead to dyslipidemia or accumulation of uremic toxins, which can induce production of free radicals and activate proinflammatory and fibrogenic factors, leading to vascular endothelial cell dysfunction and injury, and favoring development of atherosclerosis. Therefore, the kidney can be a villain or a victim during atherogenesis. The purpose of this review is to provide new insights into the mechanisms by which atherogenic factors may instigate early renal injury.

AbstractDuring the period 1979 to 1989, 0.1 % of all cases of acute appendicitis at our institution occurred soon after another operative procedure. The interval between primary operation and appendectomy was 5 to 31 days (mean, 14 days). Signs and symptoms did not differ from those of classical acute appendicitis. Duration of symptoms ranged from 12 hours to 8 days (mean, 2.4 days). Perforation was present in 3 patients, suppurative appendicitis in 1 patient, and acute inflammation in 4 patients. Two of the perforations were associated with abscess formation. Morbidity related to the appendiceal condition included hepatic abscesses, septic shock, and prolonged ileus. There was no mortality. Hospitalization ranged from 6 to 80 days (mean, 12.5 days).

Background— B-type natriuretic peptide (BNP) activation observed in cardiac diseases is a predictor of poor outcome; however, in organic mitral regurgitation (MR), BNP determinants and prognostic value are unknown. Methods and Results— We prospectively enrolled 124 patients with chronic organic MR (aged 63±15 years, 60% males) in whom we measured BNP level and simultaneously quantified MR degree, left ventricular (LV) remodeling, and left atrial (LA) volumes and analyzed long-term outcome. Baseline BNP level (54±67 pg/mL, median 31 pg/mL) was associated univariately with multiple clinical and echocardiographic characteristics, but in multivariate analysis, independent determinants of BNP, beyond age and sex (both P ≤0.01), were LV end-systolic volume index, LA volume, atrial fibrillation, and symptoms (all P <0.02). Conversely, MR degree was not independently associated with BNP. During follow-up, patients with high versus low BNP (≥31 versus <31 pg/mL) displayed lower survival rates (at 5 years, 72±10% versus 95±5%, P =0.03) and higher rates of the combined end point of death and heart failure (at 5 years, 42±10% versus 16±7%, P =0.03). In multivariate analysis, with adjustment for age, sex, functional class, MR severity, and ejection fraction, BNP was independently predictive of mortality (hazard ratio per 10 pg/mL, 1.23 [95% CI 1.07 to 1.48], P =0.004) and of death or heart failure (hazard ratio per 10 pg/mL, 1.09 [95% CI 1.001 to 1.19], P =0.04). Conclusions— BNP activation in organic MR reflects primarily ventricular and atrial consequences rather than degree of MR. Higher BNP level in patients with organic MR independently predicts adverse events under conservative management. Therefore, BNP activation in organic MR is an emerging biomarker of severity of MR consequences and of poor clinical outcome, and its assessment should be considered in the clinical evaluation and risk stratification of patients with MR.

AbstractWe have reviewed 108 cases of bacterial endocarditis treated surgically since 1968. The mean age of the patients was 47.7±15.6 years (± SD) (range, 14–79 yr). Seventy‐seven percent were male. The most common causative organisms were staphylococci (46%), streptococci viridans group (25%), and other streptococci (20%). Forty‐five percent, 25%, and 13% of patients had native aortic valve, native mitral valve, or native double valve (AV/MV) involvement, respectively. Eighteen patients had prosthetic valve endocarditis. No patient underwent surgery for tricuspid valve endocarditis. Seventy‐three patients were considered to have active endocarditis (AE) (positive blood or tissue cultures and/or annular abscesses). The 35 remaining patients had healed endocarditis (HE). Preoperative complications in patients with either AE or HE were stroke (11%, 11%), renal failure (33%, 3%;p<0.001), pulmonary edema (83%, 34%;p<0.001), anemia (36%, 8%;p<0.01), and inotrope dependence (22%, 6%;p<0.05). Hospital mortality for native valve AE was 19.6% (11/56), and for healed endocarditis, 5.7% (2/35). Independent predictors of hospital mortality were inotrope dependence (p<0.001), annular abscess (p<0.01), pulmonary edema (p<0.01), and staphylococcal infection (p<0.05). The 5‐year actuarial survival for operative survivors was 68.4±7.5% (AE) and 78.3±9.2% (HE). We conclude that the operative mortality for patients with continuing sepsis is high and that surgery should be undertaken early in staphylococcal endocarditis. If surgery is successful, then the long‐term prognosis is good.