Rapid ratiometric determination of hemoglobin concentration using UV-VIS diffuse reflectance at isosbestic wavelengths.

We developed a ratiometric method capable of estimating total hemoglobin concentration from optically measured diffuse reflectance spectra. The three isosbestic wavelength ratio pairs that best correlated to total hemoglobin concentration independent of saturation and scattering were 545/390, 452/390, and 529/390 nm. These wavelength pairs were selected using forward Monte Carlo simulations which were used to extract hemoglobin concentration from experimental phantom measurements.

Phase I study of subconjunctival ranibizumab in patients with primary pterygium undergoing pterygium surgery.

Purpose: To evaluate the safety and tolerability of ranibizumab given via subconjunctival injection in patients with primary pterygium undergoing pterygium surgery with autograft placement.

Design: Prospective, open-label pilot study.

Setting: Single-center, academic practice.

Quality of care among obese patients.

Context: Clinicians often have negative attitudes toward obesity and express dissatisfaction in caring for obese patients. Moreover, obese patients often feel that clinicians are biased or disrespectful because of their weight. These observations raise the concern that obese patients may receive lower quality of care.

Three-dimensional dynamic in vivo motion of the cervical spine: assessment of measurement accuracy and preliminary findings.

Background Context: Previous research has quantified cervical spine motion with conventional measurement techniques (eg, cadaveric studies, motion capture systems, and fluoroscopy), but these techniques were not designed to accurately measure three-dimensional (3D) dynamic cervical spine motion under in vivo conditions.

Purpose: The purposes of this study were to characterize the accuracy of model-based tracking for measuring 3D dynamic cervical spine kinematics and to demonstrate its in vivo application.

Study Design: Through accuracy assessment and application of technique, in vivo cervical spine motion was measured.

Mycobacterium abscessus endophthalmitis after Descemet's stripping with automated endothelial keratoplasty.

Purpose: To report the first case of endophthalmitis after Descemet's stripping with automated endothelial keratoplasty caused by Mycobacterium abscessus.

Methods: Observational case report.

Results: An immunocompetent 88-year-old woman presented with endophthalmitis 2 months after a routine Descemet's stripping with automated endothelial keratoplasty resulting in decreased visual acuity and persistent vitreous opacities despite aggressive medical treatment.

Neighborhood Racial Isolation, Disorder and Obesity.

Recent research suggests that racial residential segregation may be detrimental to health. This study investigates the influence of neighborhood racial isolation on obesity and considers the role of neighborhood disorder as a mediator in this relationship. For the city of Philadelphia, we find that residence in a neighborhood with high black racial isolation is associated with a higher body mass index and higher odds of obesity among women, but not men, highlighting important sex differences in the influence of neighborhood structure on health.

Use of ultra-high-resolution optical coherence tomography to detect in vivo characteristics of Descemet's membrane in Fuchs' dystrophy.

Purpose: To demonstrate the capability of ultra-high-resolution (UHR) anterior segment optical coherence tomography (OCT) to image Descemet's membrane (DM) and measure its thickness in vivo. (2) To evaluate the use of DM characteristics and thickness in the diagnosis of Fuchs' dystrophy.

Design: Case-control study.

Social capital and glucose control.

There is a growing diabetes epidemic in the United States and if we are to halt its progress we need to better understand the social determinants of this disease and its control. Social capital, which has been associated with general health and mortality, may be one important mediator of glucose control. In this study we determine if neighborhood social capital is associated with glucose control, independent of individual factors.

Interns overestimate the effectiveness of their hand-off communication.

Objective: Theories from the psychology of communication may be applicable in understanding why hand-off communication is inherently problematic. The purpose of this study was to assess whether postcall pediatric interns can correctly estimate the patient care information and rationale received by on-call interns during hand-off communication.

Methods: Pediatric interns at the University of Chicago were interviewed about the hand-off.

Estimation of the age at onset in spinocerebellar ataxia type 2 Cuban patients by survival analysis.

Previous studies have investigated the close association that exists between CAG repeat number and the age at onset in SCA2 = spinocerebellar ataxia type 2. These studies have focused on affected individuals. To further characterize this association and estimate the risk of a carrier developing SCA2 at a particular age as a function of a specific CAG repeat size, we have analyzed a large group of 924 individuals, including 394 presymptomatic and 530 affected individuals with a CAG repeat length of 32-79 units.

Mortality attributable to obesity among middle-aged adults in the United States.

Obesity is considered a major cause of premature mortality and a potential threat to the longstanding secular decline in mortality in the United States. We measure relative and attributable risks associated with obesity among middle-aged adults using data from the Health and Retirement Study (1992-2004). Although class II/III obesity (BMI > or = or = 35.

Multiple linear regression model for predicting biomass digestibility from structural features.

A total of 147 model lignocellulose samples with a broad spectrum of structural features (lignin contents, acetyl contents, and crystallinity indices) were hydrolyzed with a wide range of cellulase loadings during 1-, 6-, and 72-h hydrolysis periods. Carbohydrate conversions at 1, 6, and 72 h were linearly proportional to the logarithm of cellulase loadings from approximately 10% to 90% conversion, indicating that the simplified HCH-1 model is valid for predicting lignocellulose digestibility. The HCH-1 model is a modified Michaelis-Menton model that accounts for the fraction of insoluble substrate available to bind with enzyme.

Metabolic syndrome and weight gain in adulthood.

Background: The influence of long-term adult weight history on metabolic risk independent of attained body mass index (BMI) is unknown.

Methods: Using nationally representative data on adults aged 50-64 years from the 1999-2006 National Health and Nutrition Examination Surveys, we examined weight change for two periods of adulthood: prime age (age 25-10 years ago) and midlife (the last 10 years). Weight changes in each period were categorized as stable (gain <10 kg) or gain (gain >or=10 kg) to create weight history comparison groups: stable-stable, gain-stable (prime age gain), stable-gain (midlife gain), and gain-gain (continuous gain).

Weight change, initial BMI, and mortality among middle- and older-aged adults.

Background: It is not known how the relationship between weight change and mortality is influenced by initial body mass index (BMI) or the magnitude of weight change.

Methods: We use the nationally representative Health and Retirement Study (n = 13,104; follow-up 1992-2006) and Cox regression analysis to estimate relative mortality risks for 2-year weight change by initial BMI among 50- to-70-year-old Americans. We defined small weight loss or gain as a change of 1-2.

Increased CD62e(+) endothelial microparticle levels predict poor outcome in pulmonary hypertension patients.

Background: Endothelial and leukocytes-derived microparticles (EMPs and LMPs, respectively) are increased in patients with pulmonary hypertension (PH). We hypothesized that the levels of circulating EMPs and LMPs could predict outcome in these patients.

Methods: Patients undergoing right heart catheterization for untreated pre-capillary PH were eligible for the study.

Fundamental cause theory, technological innovation, and health disparities: the case of cholesterol in the era of statins.

Although fundamental cause theory has been highly influential in shaping the research literature on health disparities, there have been few empirical demonstrations of the theory, particularly in dynamic perspective. In this study, we examine how income disparities in cholesterol levels have changed with the emergence of statins, an expensive and potent new drug technology. Using nationally representative data from 1976 to 2004, we find that income gradients for cholesterol were initially positive, but then reversed and became negative in the era of statin use.

Outcomes of cranial repair after craniectomy.

Object: Hemicraniectomy is a commonly practiced neurosurgical intervention with a wide range of indications and clinical data supporting its use. The extensive use of this procedure directly results in more cranioplasties to repair skull defects. The complication rate for cranial repair after craniectomy seems to be higher than that of the typical elective craniotomy.

Dilution rates for tailpipe emissions: effects of vehicle shape, tailpipe position, and exhaust velocity.

The rate at which motor vehicle exhaust undergoes dilution with ambient air will greatly affect the size distribution characteristics of the particulate emissions. Wind tunnel experiments were conducted to investigate the impacts of vehicle shape, tailpipe orientation, and exhaust exit velocity on the dilution profiles under steady driving conditions for three model vehicles: a light-duty truck, a passenger car, and a heavy-duty tractor head. A three dimensional array of 60 sensors provided simultaneous measurements of dilution ratios for the emissions in the near- and far-wake regions downstream of the vehicle.

Wind tunnel measurements of the dilution of tailpipe emissions downstream of a car, a light-duty truck, and a heavy-duty truck tractor head.

The particle and gaseous pollutants in vehicle exhaust emissions undergo rapid dilution with ambient air after exiting the tailpipe. The rate and extent of this dilution can greatly affect both the size evolution of primary exhaust particles and the potential for formation of ultrafine particles. Dilution ratios were measured inside of a wind tunnel in the region immediately downstream of the tailpipe using model vehicles (approximately one-fifth to one-seventh scale models) representing a light-duty truck, a passenger car, and a heavy-duty tractor head (without the trailer).

A human embryonic kidney 293T cell line mutated at the Golgi alpha-mannosidase II locus.

Disruption of Golgi alpha-mannosidase II activity can result in type II congenital dyserythropoietic anemia and induce lupus-like autoimmunity in mice. Here, we isolated a mutant human embryonic kidney (HEK) 293T cell line called Lec36, which displays sensitivity to ricin that lies between the parental HEK 293T cells, in which the secreted and membrane-expressed proteins are dominated by complex-type glycosylation, and 293S Lec1 cells, which produce only oligomannose-type N-linked glycans. Stem cell marker 19A was transiently expressed in the HEK 293T Lec36 cells and in parental HEK 293T cells with and without the potent Golgi alpha-mannosidase II inhibitor, swainsonine.

A robust Monte Carlo model for the extraction of biological absorption and scattering in vivo.

We have a toolbox to quantify tissue optical properties that is composed of specialized fiberoptic probes for UV-visible diffuse reflectance spectroscopy and a fast, scalable inverse Monte Carlo (MC) model. In this paper, we assess the robustness of the toolbox for quantifying physiologically relevant parameters from turbid tissue-like media. In particular, we consider the effects of using different instruments, fiberoptic probes, and instrument-specific settings for a wide range of optical properties.

Racial differences in the impact of comorbidities on survival among elderly men with prostate cancer.

This study investigates differences in the effects of comorbidities on survival in Medicare beneficiaries with prostate cancer. Medicare data were used to assemble a cohort of 65- to 76-year-old Black (n = 6,402) and White (n = 47,458) men with incident localized prostate cancer in 1999 who survived >or=1 year postdiagnosis. Comorbidities were more prevalent among Blacks than among Whites.

Quantitative physiology of the precancerous cervix in vivo through optical spectroscopy.

Cervical cancer is the second most common female cancer worldwide. The ability to quantify physiological and morphological changes in the cervix is not only useful in the diagnosis of cervical precancers but also important in aiding the design of cost-effective detection systems for use in developing countries that lack well-established screening and diagnostic programs. We assessed the capability of a diffuse reflectance spectroscopy technique to identify contrasts in optical biomarkers that vary with different grades of cervical intraepithelial neoplasia (CIN) from normal cervical tissues.