Screening for rectal chlamydia infection in a genitourinary medicine clinic

Our department has been offering routine rectal chlamydia testing to all individuals reporting ano-receptive sex since 2002. We wanted to determine the prevalence of rectal chlamydia and if there were any factors associated with a positive diagnosis. A retrospective case-notes analysis was performed of all individuals tested for rectal chlamydia from November 2002 until March 2005. In total, 1187 case-notes were examined. Overall, the prevalence of chlamydia infection was 8.5%; in asymptomatic individuals, it was 5.1%. There was a positive association with chlamydia infection in patients who were HIV-positive, those who reported rectal symptoms and from samples in which microscopy of a rectal smear demonstrated >10 polymorphonuclear cells/high power field. The findings support our continuing to offer rectal chlamydia screening to patients attending our service. Chlamydia trachomatis infection should be considered as a possible diagnosis in patients who present with rectal symptoms outside a genitourinary medicine clinic setting.     

Predicting the status of axillary lymph nodes in breast cancer: A multiparameter approach including axillary ultrasound scanning

In a prospective study, we attempted to predict axillary metastases in 135 breast cancer patients by a preoperative multiparameter evaluation including axillary ultrasound scanning (US). After surgery, factors associated with lymph node metastases by univariate analysis were included in a multivariate model. By multivariate analysis, the stronger independent predictors of lymph node metastases were suspicious axillary US (p < 0.001), tumor location in the outer quadrants (p = 0.001) and high Ki-67 index (>10%) (p = 0.002). A predictive model based on these variables, identified a high-risk group (20.0%) represented by women with suspicious axillary US, tumor in the outer quadrants and high Ki-67 index, with axillary metastases in 100%, whereas all patients with opposite features (8.1%) had uninvolved axillary lymph nodes. This multiparameter evaluation including axillary US may be used to optimize the selection of breast cancer patients candidate to sentinel lymph node biopsy or axillary lymph node dissection. The accuracy of this predictive model still requires prospective validation in a larger sample of women.     

Axillary ultrasound scanning in the follow-up of breast cancer patients undergoing sentinel node biopsy

In breast cancer patients with negative sentinel node biopsy (SNB), surveillance of the unremoved nodes is recommended. Clinical examination has poor sensitivity. The aim of this study was to evaluate the role of axillary ultrasound scan (AUS) in the follow-up of these patients. AUS was performed every 12 months in a series of 165 patients with negative SNB. During the follow-up (median 45.6 months), in 154 patients, the AUS was carried out as a routine examination and in three cases (1.9%) it showed suspicious nodes, which underwent core biopsy. No evidence of axillary recurrence was found. Conversely, in 11 patients, AUS was performed to clarify a palpable lymphadenopathy; none of them was suspicious at US. We conclude that routine AUS to follow-up patients who have had a negative SNB is unnecessary. However, AUS may be useful in the presence of palpable nodes, to select those patients who do not require biopsy.     

The effect of ionizing radiation on intraocular lenses

BACKGROUND: The native crystalline lens is the principal shield against ultraviolet radiation (UV), damage to the human retina. Every year in the United States, more than one million patients undergo removal of the natural lens in the course of cataract surgery (phakectomy), at which time an intraocular lens (IOL) is placed in the lens capsule. The IOL thenceforth serves as the principal barrier to ultraviolet radiation over the life of the implant, potentially for decades. The synthetic organic molecules of which IOLs are composed offer little UV protection unless ultraviolet-absorbing chromophores are incorporated into the lens material during manufacture. However, chromophores are alkenes potentially subject to radiolytic degradation. It is unknown whether ionizing radiation at clinical doses (e.g., to the brain or in the head-and-neck region) affects the UV-absorbing capacity of chromophore-bearing IOLs and consequently exposes the retina to potentially chronic UV damage. In addition, the polymers of which IOLs are composed are themselves subject to radiation damage, which theoretically might result in optical distortion in the visible light range. OBJECTIVE: To determine whether megavoltage photon ionizing radiation alters the absorption spectra of ultraviolet-shielding polymethylmethacrylate (PMMA) and organopolysiloxane (silicone) intraocular lenses (IOLs) in the UV (280 nm < or = lambda < 400 nm), visible (400 nm < or = lambda < or = 700 nm), and low-end near-infrared (700 nm < lambda < or = 830 nm) ranges.DESIGN: Prospective, nonrandomized trial of dose-paired IOL cohorts. METHODS: Fourteen IOLs, seven of PMMA (Chiron 6842B) and seven of silicone (IOLAB L141U), were paired and examined for absorption spectra in 1-nm intervals over the range lambda = 280-830 nm on a Cary 400 deuterium and quartz halogen source-lamp UV/visible spectrophotometer before and after undergoing megavoltage ionizing irradiation to doses of 2, 5, 10, 20, 40, 60, and 100 Gray, respectively. Because of artifactual aberrations inherent in analyzing convex lenses on a conventional flat-plate spectrophotometer, post-irradiation absorption spectra were subsequently reanalyzed on a Cary 300 spectrophotometer outfitted with a Labsphere Diffused Reflectance Accessory (DRA-CA-30-I) incorporating a Spectralon-coated integrating sphere. MAIN OUTCOME MEASURES: Primary: Changes in UV absorbance after irradiation. Secondary: Changes in visible and low-end near-infrared absorbance after irradiation. RESULTS: Photon ionizing radiation in the 2-Gy to 100-Gy range produced no detectable alterations in the UV (280 nm < or = lambda < 400 nm), visible (400 nm < or = lambda < or = 700 nm), or low-end near-infrared (700 nm < lambda < or = 830 nm) absorption spectra of any of the lenses irradiated. However, silicone IOLs as a group revealed peak post-irradiation UV absorption at a shorter wavelength than did PMMA IOLs, with marginally greater UV transmission at the uppermost extreme of the UV spectrum (lambda = 384.5-400 nm). CONCLUSIONS: At clinically relevant doses used in radiation therapy, megavoltage photon ionizing radiation produces no significant alterations in the absorption spectra of PMMA and silicone IOLs over the range lambda = 280- 830 nm. These findings indicate that, even at supraclinical doses, the UV-absorbing capacity of chromophore-bearing PMMA and silicone IOLs remains unimpaired. It is not clear whether the lower UV peak of silicone lenses represents a radiation effect or a peculiarity of the chromophore used in the lenses tested.     

Finger Impedance Evaluation by Means of Hand Exoskeleton

Modulation of arm mechanical impedance is a fundamental aspect for interaction with the external environment and its regulation is essential for stability preservation during manipulation. Even though past research on human arm movements has suggested that models of human finger impedance would benefit the study of neural control mechanisms and the design of novel hand prostheses, relatively few studies have focused on finger and hand impedance. This article touches on the two main aspects of this research topic: first it introduces a mechanical refinement of a device that can be used to effectively measure finger impedance during manipulation tasks; then, it describes a pilot study aimed at identifying the inertia of the finger and the viscous and elastic properties of finger muscles. The proposed wearable exoskeleton, which has been designed to measure finger posture and impedance modulation while leaving the palm free, is capable of applying fast displacements while monitoring the interaction forces between the human finger and the robotic links. Moreover, due to the relatively small inertia of the fingers, it allows us to meet some stringent specifications, performing relatively large displacements (∼45°) before the stretch reflex intervenes (∼25 ms). The results of measurements on five subjects show that inertia, damping, and stiffness can be effectively identified and that the parameters obtained are comparable with values from previous studies.     

Optimal dietary intake for cardiovascular risk reduction

Healthful dietary intake and physical activity are advocated as first-line prevention and treatment of many diseases. Dietary intake plays a major role in preventing and promoting the leading cause of death in the United States: cardiovascular disease. Despite continually growing evidence on the relationship between nutrition and cardiovascular risk, many Americans consume an atherogenic diet resulting in a proinflammatory and prothrombotic dysmetabolic state. Overconsumption of fat, sugar, and refined carbohydrates has led to overweight and obesity for most Americans and is associated with the increasing prevalence of cardiovascular risk factors, including type 2 diabetes mellitus, hypertension, and dyslipidemia. This article reviews the association between dietary intake and cardiovascular risk and summarizes optimal dietary intake for cardiovascular risk reduction.