Mechanism of action of nonachlazin on nervous regulation of coronary circulation

In experiments on cats and dogs under general anesthesia nonachlazine, a new antianginal agent, depressed the reflex decrease of the blood flow to the coronary arteries (electromagnetic recording). Nonachlazine also depressed the reflex decrease of the blood flow in the system of common carotic artery, and the pressure vasomotor reflexes. During recording the tonic and reflex activity in the heart sympathetic nerves nonachlazine proved to selectively inhibit the vasoconstrictor impulses from Adelta-afferent fibers of the spinal nerves, that is it influenced the vasomotor component of the "primary" pain reaction. This mechanism could underlie the block by nonachlazine of the pain syndrome during the heart ischemia disease.     

Synthesis of nanocrystalline fluorinated hydroxyapatite by microwave processing and its in vitro dissolution study

Synthetic hydroxyapatite, (Ca₁₀(PO₄)₆(OH)₂, HA), is an important material used for orthopedic and dental implant applications. The biological hydroxyapatite in the human bone and tooth is of nanosize and differs in composition from the stoichiometric HA by the presence of other ions such as carbonate, magnesium, fluoride, etc. Osseointegration is enhanced by using nanocrystalline HA. This stimulates the interest in synthesizing nanocrystalline HA by different routes and among the methods, microwave processing seems to form the fine grain size and uniform characteristic nanocrystalline materials. Fluorinated hydroxyapatite, (FHA, Ca₁₀(PO₄)₆(OH)_2−x F _x ), possesses higher corrosion resistance in biofluids than pure HA and reduces the risk of dental caries. The present work deals with the synthesis of nanocrystalline FHAs by microwave processing. The crystal size and morphology of the nanopowers were examined by X-ray powder diffraction (XRD) and transmission electron microscopy (TEM) methods. The functional groups present in FHA powders were ascertained by Fourier transform infrared spectroscopy (FT-IR) and laser Raman spectroscopy. Since the physiological stability is an important parameter while selecting the material for implantation, the in vitro dissolution studies of FHAs with different fluorine contents were carried out.     

HIV risk behaviors associated with the injection process: multiperson use of drug injection equipment and paraphernalia in injection drug user networks

This study examines drug acquisition and multiperson use of paraphernalia, drugs, and needles/syringes. Ethnographers observed 54 injection episodes in which IDUs were linked by HIV risk behaviors, and developed a typology of higher-risk, lower-risk, and nonsharing-risk networks. Multiperson use of injection paraphernalia or drug solution occurred in most injection events (94%). Serial use of syringes/needles occurred infrequently (14%) relative to "backloading" (37%) and reuse of paraphernalia (cookers 84%, cotton 77%, water 77%). Higher-risk injection networks were characterized by larger size and pooling of resources for drugs. Prevention messages must include avoiding reuse of injection paraphernalia and transfer of drug solution.     

Establishing the doctor-patient relationship: science, art, or competence?

Establishing and sustaining strong doctor-patient relationships is an important aim in clinical practice, since it is through these relationships that the effectiveness of our work as healers is mediated. In recent years, a research literature emerging from the application of social science to medicine is beginning to highlight certain specific physician behaviors, especially those involved in doctor-patient communication, as actions of considerable importance to both physicians and patients. Successful physicians will further understand that our patients and their families also have high expectations for additional behaviors of physicians, particularly those recognized in the popular culture as professional, respectful of patients' circumstances, and supportive of patients' efforts. To the extent that physicians make an explicit effort to understand and appreciate the "life-world" of patients, and even to modify medical recommendations in order to maximize the meaningfulness and goodness-of-fit of these recommendations, the "art" of medicine also becomes an essential part of routine clinical practice. In the final analysis, new science, art, and behavioral competence are all required for strengthening doctor-patient relationships.     

Self-rated health as a predictor of ischemic heart disease development

The study objective was to analyse the association between self-rated health and the incidence of fatal and non-fatal coronary heart disease in a Danish cohort followed up over 16 years. The study included 1052 men and women born in 1936. During the 16 years' follow-up 50 cases of coronary heart disease were registered either with the Danish register of deaths or the register of hospital admissions. Univariate analysis showed the following relative risks of coronary heart disease in the four self-rated health groups: "extremely good": 1.0, "good": 4.0, "poor": 5.8, "miserable": 12.1 (p = 0.02). After control for the conventional coronary risk factors and a substantial number of other potential confounders the relative risks were: 1.0, 4.2, 6.5, and 18.6 (p = 0.02) respectively. Self-rated health was an independent predictor of coronary heart disease in this recent cohort. If confirmed, the association between self-rated health and coronary heart disease may lead to new insights into psychosocial processes leading to this disease.     

Chronic evaluation of orthotopically implanted bileaflet mechanical aortic valves in adult domestic sheep

Papillary carcinoma is the most common form of thyroid carcinoma and, generally, it has a more favorable prognosis than other carcinoma types, although diverse variants or subtypes have been described, some of which appear to have a less favorable prognosis. Recently, a new variant, the so-called "Warthin-like tumor" or "tall-cell variant with extensive lymphocytic infiltration of papillary thyroid carcinoma" with behavior similar to the usual papillary carcinoma, has been described. We present a case with the cytohistological pattern of "Warthin-like tumor" of the thyroid. Immunohistochemistry revealed reactivity at the epithelium lining papillae for antimitochondrial 113-I antibody and also membranous positivity for CD15 (Leu M1). Lymphoid stroma showed an immunoprofile similar to chronic lymphocytic thyroiditis. These findings point to the consideration of "Warthin-like tumor" as being a hybrid neoplasm between the tall-cell variant and oxyphilic papillary carcinoma associated to a lymphoid-rich stroma.     

Prognosis of gastrointestinal smooth-muscle (stromal) tumors: dependence on anatomic site

OBJECTIVES: To assess how the community urologist employs intravesical therapy in patients with transitional cell carcinoma (TCC) of the bladder because most data on intravesical therapy reflect the experience of major referral centers. METHODS: The medical records of 234 consecutive patients with TCC were reviewed. Sixty-nine patients received intravesical treatment before referral. The initial pathologic findings, the indication for treatment (eg, grade and stage, initial versus recurrent tumor), the schedule of intravesical therapy, and the drug selected for each course of treatment were assessed. RESULTS: A total of 1 39 courses of intravesical treatment were given to 69 patients; thus, the avarage number of courses was 2.02 per patient. The drug used was bacillus Calmette-Guerin (BCG) in 81 (58%), mitomycin C in 34 (24%), thiotepa in 16 (12%), Adriamycin in 4 (3%), and unknown in 4 (3%). Intravesical treatment was given after transurethral resection of the initial tumor in 33 patients; the initial pathologic finding was high grade (ie, grade 3 or carcinoma in situ) and/or Stage T1 in 22, TaG1-G2 in 9, and unknown in 2. One course of treatment was administered to 34 patients (49%) and two or more courses to 35 patients (51%). Eleven patients with TaG 1 -2 tumors were treated repetitively despite failure, with an average of 3.5 courses per patient; the drug used was BCG in 44%. Nineteen percent of patients received maintenance therapy. Intravesical therapy had to be discontinued in 10 patients because of side effects; 8 patients (12%) developed small contracted bladders and severe irritative symptoms, 3 required cystectomy despite the lack of bladder cancer. CONCLUSIONS: Intravesical therapy in community practice conforms with the generally accepted indications for high-grade and T1 disease. However, the use of BCG for low-grade TCC appears to be quite common. Repeated courses may result in significant side effects. We emphasize that excessive treatment should be avoided for low-grade, Ta lesions and BCG reserved for patients with TaG3, carcinoma in situ, or T1 TCC.     

A Facile Strategy for Preparation of Fluorescent SWNT Complexes with High Quantum Yields Based on Ion Exchange

The fluorescent imidazolium salt (1,3‐bis(9‐anthracenylmethyl)imidazolium chloride, [bamim]Cl) has been grafted onto the surfaces of single‐walled carbon nanotubes (SWNTs) using an ion exchange strategy based on metathesis of the K⁺ ion in CO₂K derivatized SWNTs with [bamim]⁺. The resulting SWNT‐[bamim] complex has been characterized with high‐resolution transmission electron microscopy (HR‐TEM), X‐ray photoelectron spectroscopy (XPS), elemental mapping, and elemental linear profiles analysis. A blue light emission can be observed at 392, 414 and 438 nm for SWNT‐[bamim] upon being excited at 254 nm. The quantum yield (QY) of the SWNT‐[bamim] complex (0.40) is much higher than that of SWNT/[bamim]Cl (0.02), used as a control, and prepared using a π‐π stacking method, indicating that ion exchange is a far more effective strategy for retaining a high QY. Additionally, UV‐Vis‐NIR and Raman spectroscopy show that the SWNT‐[bamim] complex can maintain the one‐dimensional electronic states of SWNTs. Other imidazolium salts have also been successfully grafted onto SWNTs via the same strategy, indicating that the ion exchange process can serve as a universal strategy for the functionalization of SWNTs.     

Interaction of dendritic cells with skin endothelium: A new perspective on immunosurveillance

The goal of this study was to determine the mechanisms by which dendritic cells (DCs) in blood could interact with endothelium, a prerequisite to extravasation into tissues. Our results indicate that DCs express both HECA-452-reactive and nonreactive isoforms of P-selectin glycoprotein ligand 1 (PSGL-1) and can tether and roll efficiently on E- and P-selectin under flow conditions in vitro. Freshly isolated blood DCs were further observed to roll continuously along noninflamed murine dermal endothelium in vivo. This interaction is strictly dependent on endothelial selectins, as shown by experiments with blocking antibodies and with E- and P-selectin-deficient mice. We hypothesize that DCs in blood are constitutively poised at the interface of blood and skin, ready to extravasate upon induction of inflammation, and we showed that cutaneous inflammation results in a rapid recruitment of DCs from the blood to tissues. We propose that this is an important and previously unappreciated element of immunosurveillance.