Digital imaging of the chest

During the past several years, image acquisition in nuclear medicine, computed tomography, ultrasonography, subtraction angiography, and magnetic resonance has been by digitization. Despite these advances, research in the development of digital imaging in conventional radiography has lagged behind. Although studies with a variety of digital techniques have been carried out on several fronts, we still do not possess a method that has captured the imagination of the majority of radiologists and other physicians to a point where it could replace conventional screen-film imaging. This article reviews the current status and general principles of the technology, focusing on the four digital radiographic techniques that have shown the greatest promise - film digitization, an image intensifier - based system, photostimulable phosphor plates, and a scanned projection system. The physical aspects of each of the four systems and the clinical results that have been reported to date, as well as the advantages and disadvantages of each system, are presented.     

Pulpal response to chemically cured and experimental light-cured glass ionomer cavity liners

This investigation evaluated the effects of an experimental light-cured glass ionomer (LCGI) cavity liner and chemically cured Ketac-Bond glass ionomer restorative material on the pulpal tissues of monkeys. Class V cavities were prepared in 71 teeth of three adult Macaca mulatta monkeys at 7- and 35-day intervals. Ketac-Bond or LCGI cavity liners were placed in cavities with the smear layer intact (groups I and II) or with the smear layer removed (groups III and IV) and were restored with composite resin. Tissues were acquired, sectioned at 7 microns, stained for microscopic evaluation, or prepared for SEM evaluation. No statistically significant differences between materials existed at either time interval, regardless of smear layer presence. Histopathologic results demonstrated minimal pulpal reactions for groups I through IV. SEM analysis showed tenacious bonding of the LCGI material to prepared cavity walls, with absence of contraction gap formation. The results indicated excellent pulpal responses to both materials.     

Obesity and body fat distribution and breast cancer prognosis

This study addresses the effect of obesity and body fat distribution on axillary lymph node involvement, tumor size, and estrogen receptor (ER) level in breast cancer patients. Anthropometric measurements were prospectively obtained on 248 consecutively and newly diagnosed women with invasive breast cancer. The anthropometric measurements evaluated were abdomen, thigh, subscapular, and midaxillary skinfolds; weight; and height. Weight and Quetelet Index (kg/m2) were significantly (P = 0.001) associated with lymph node involvement in postmenopausal patients. The abdomen:thigh skinfold ratio was significantly higher in premenopausal patients (P = 0.004) and postmenopausal (P = 0.03) without axillary node involvement compared with women with 4+ axillary node involvement. The abdomen:thigh skinfold was higher (P = 0.05) in women with smaller breast cancers (less than 2.0 cm) and higher ER levels. Weight and Quetelet Index did not affect tumor size or ER level. This study demonstrated that obese postmenopausal women who developed breast cancer tend to have more axillary node involvement than their leaner counterparts. Generalized obesity did not affect tumor size or ER level. Premenopausal and postmenopausal women with upper body fat distribution appear to be a subset of women who have a more favorable prognosis as measured by less lymph node involvement, smaller tumors, and higher levels of ER in their tumors.     

Myocardial performance after cardiopulmonary bypass and cardioplegic arrest: impact of na+/h+ exchanger inhibition.

This study was designed to determine if pretreatment with a sodium/hydrogen exchange inhibitor (EMD 96 785) improves myocardial performance and reduces myocardial edema after cardioplegic arrest (CPA) and cardiopulmonary bypass (CPB). Anesthetized canines (n = 18) were instrumented with vascular catheters, myocardial ultrasonic crystals, and left ventricle (LV) micromanometer to measure preload recruitable stroke work (PRSW), +dP/dt(max), and cardiac output. Serial myocardial tissue water content (MWC) was determined from sequential biopsy. After baseline measurements, hypothermic (28 degrees C) cardiopulmonary bypass was initiated. CPA was maintained for 2 h, followed by reperfusion/rewarming and separation from CPB. PRSW and myocardial tissue water were measured at 30, 60, and 120 min after CPB. EMD 96 785 (3 mg/kg) was given 15 min prior to CPB. Controls received the same volume of saline vehicle. It was found that MWC increased from baseline in both EMD 96 785 and controls with CPB/CPA. PRSW decreased from baseline at 30 and 60 min post CPB/CPA in controls; PRSW did not decrease from baseline with EMD 96 785, and was statistically greater at 30 and 60 min post CPB/CPA compared to controls. Thus, Na(+)/H(+) exchanger inhibition with EMD 96 785 (3 mg/kg) pretreatment improves post-CPB/CPA myocardial performance without reducing myocardial edema. Na(+)/H(+) exchanger inhibition during cardiac procedures using CPB/CPA may be a useful adjunct to improve immediate post-CPB/CPA myocardial performance.     

Delayed growth and maturation of astrocytic cultures following exposure to ethanol: electron microscopic observations

This investigation examined the effects of ethanol on the morphologic features of cultured rat astrocytes using a treatment paradigm that provided consistent exposure to ethanol at concentrations of 0.2%, 0.5%, or 1.0% (w/v). Cultures were assessed between 4 and 8 days in vitro during the logarithmic phase of growth; differences in culture growth, cell profile area and ultrastructural configuration were found. A dose-dependent inhibition of culture growth was observed after 48 and 96 h of ethanol exposure. In control cultures, the consequences of culture growth included the progressive crowding of cells, a concomitant reduction in the cell profile area, and increased cell-cell contact. On culture day 8, electron microscopic examination of control cultures demonstrated a complex stratified cellular layer, the junction of cells by puncta adhaerentia and the acquisition of intermediate filament bundles. In contrast, the impaired growth in ethanol-exposed cultures was associated with the retention of an extensive cell profile area suggesting restrained morphologic development. At the electron microscopic level, ethanol-exposed cultures showed a dose-dependent attenuation in both the depth and complexity of the cell layer. These findings indicated that the growth kinetics and morphologic development of astrocytic cultures are vulnerable to ethanol exposure at moderate and high levels. These findings were attributed to both ethanol cytotoxicity and a deprivation of cellular interaction resulting from the restricted population size.     

Use of monoclonal antiestrogen receptor antibody to evaluate estrogen receptor content in fine needle aspiration breast biopsies.

A monoclonal antibody prepared against estrogen receptor has been shown to be highly specific and sensitive for the detection and quantification of estrogen receptor in human breast lesions using immunohistochemical methods. A semiquantitative relationship has been shown between the intensity of staining and biochemical receptor analysis. To evaluate the usefulness of this technique in fine needle aspiration biopsies, 41 cases of breast cancer were studied. Nuclear localization of receptor antibody PAP complex was observed. Comparison of the immunocytochemical analysis of the aspiration cytologic specimens to the biochemical analysis of the excised tumor mass revealed a sensitivity and specificity of 80% and 89%, respectively. There was a significant semiquantitative correlation between the methods. These results extend the observation that antireceptor monoclonal antibody in immunohistochemical analysis is an effective tool in the evaluation of estrogen receptor content in human breast lesions and with careful specimen handling and proper controls may be extended to the evaluation of fine needle aspiration biopsies.     

Female sexual response and the timing of partner orgasm

Although orgasm can be experienced in many ways with or without a partner, partner involvement continues to be a noted preference for many women. In order to examine the timing of partner orgasm in relationship to female sexual response, women who usually experience orgasm before, simultaneously, or after their male partner's first orgasm were examined in the context of their orgasmic behaviors, role of their partners in sexual interaction, and their level of sexual satisfaction. A survey research design, which utilized the responses of 709 adult women, indicated that those women who usually experienced orgasm after their male partners perceived less physiological and psychological sexual satisfaction. Furthermore, several other significant results were found regarding timing of partner orgasm. With the failure to reach orgasm through sexual intercourse being reported by women as a common sexual complaint, sex educators and therapists can use these findings to facilitate an increased awareness of timing factors influencing satisfying sexual relationships.