Tunable ligand emission of napthylsalophen triple-decker dinuclear lanthanide(iii) sandwich complexes.

The fluorescent ligand 1,1'-((1E,1'E)-(1,2-phenylenebis(azanylylidene))bis(methanylylidene)) bis(naphthalen-2-ol) (H2L) was used to prepare lanthanide(iii) metal complexes. These were found to self-assemble as triple decker sandwich complexes of the type (Ln2L3), where Ln = Pr(iii), Nd(iii), Sm(iii), Eu(iii), Gd(iii), Tb(iii), Dy(iii), Ho(iii), Er(iii), Yb(iii), or Lu(iii). The structures of the complexes Nd2L3, Gd2L3, Tb2L3, Dy2L3, Ho2L3, Yb2L3, and Lu2L3 are structurally characterized by single crystal X-ray diffraction. In the Nd2L3 complex, both metals are 8 coordinate. Yb2L3, Tb2L3, Dy2L3, and Lu2L3 are isostructural. In these, as in the Gd2L3 and Ho2L3 complexes, one metal is 8 coordinate, one 7 coordinate. The ligand was found to have tunable emission in the solid state across the lanthanide series with a maximum at 556 nm for the Sm2L3 complex to 617 nm for Er2L3. Of these, most demonstrate only ligand-centered fluorescence at room temperature. The ligand was found to have much greater fluorescence in the complex Lu2L3. Here, we describe these distinctive triple decker complexes and their absorption and emission properties as both solids and solutions.

Human exposure to selamectin from dogs treated with revolution: methodological consideration for selamectin isolation.

This study was undertaken to determine selamectin residue in dog's blood and in gloves worn while petting dogs after Revolution application. Revolution contains the active ingredient selamectin (a semisynthetic avermectin), which controls endoparasites and ectoparasites, including adult fleas, flea eggs, ticks, heartworms, ear mites, and sarcoptic mange in dogs, for 30 days. Revolution was applied topically on a group of six adult house hold dogs (240 mg selamectin/dog). The gloves worn for 5 min while petting the dogs were collected in glass jars and the blood samples (5 mL/dog) were collected in EDTA tubes at 0 h, 24 h, and 72 h, and at 1, 2, 3, 4, and 5 weeks post-Revolution application for selamectin residue determination. At no time during the study did the dogs show any signs of toxicity, weight loss, or change in body temperature. Extracts of the blood and the gloves were analyzed for selamectin residue using RP-HPLC coupled with a UV detector (246 nm). Selamectin standard used for peak identification and quantitation was purified from Revolution. Selamectin residue was detected in the blood (10.26 +/- 1.06 ng/mL) only at 72 h post-Revolution application, probably due to its poor dermal absorption and rapid elimination from the circulation. In the glove extracts, the highest concentration of selamectin (518.90 +/- 66.80 ppm) was detected 24 h after Revolution application. Transferable residue of selamectin in gloves from dog's coat was detected at a lesser magnitude after 1 week of Revolution application, and that was followed by a further descending trend during the second, third, and fourth weeks. No selamectin residue was detected in the glove extracts after the fifth week. In spite of selamectin's binding to the sebaceous glands of the skin, gloves contained significant transferable residue. Thus, these findings suggest that repeated exposure to selamectin can pose potential health risks, especially to veterinarians, veterinary technologists, dog trainers/handlers, and pet owners.

Importance of hydroxyl radical in the vanadium-stimulated oxidation of NADH.

Vanadium compounds are known to stimulate the oxidation of NAD(P)H, but the mechanism remains unclear. This reaction was studied spectrophotometrically and by electron spin resonance spectroscopy (ESR) using vanadium in the reduced state (+4, vanadyl) and the oxidized state (+5, vanadate). In 25 mM sodium phosphate buffer at pH 7.4, vanadyl was slightly more effective in stimulating NADH oxidation than was vanadate. Addition of a superoxide generating system, xanthine/xanthine oxidase, resulted in a marked increase in NADH oxidation by vanadyl, and to a lesser extent, by vanadate. Decreasing the pH with superoxide present increased NADH oxidation for both vanadate and vanadyl. Addition of hydrogen peroxide to the reaction mixture did not change the NADH oxidation by vanadate, regardless of concentration or pH. With vanadyl however, addition of hydrogen peroxide greatly enhanced NADH oxidation which further increased with lower pH. Use of the spin trap DMPO in reaction mixtures containing vanadyl and hydrogen peroxide or a superoxide generating system resulted in the detection by ESR of hydroxyl. In each case, the hydroxyl radical signal intensity increased with vanadium concentration. Catalase was able to inhibit the formation of the DMPO--OH adduct formed by vanadate plus superoxide. These results show that the ability of vanadium to act in a Fenton-type reaction is an important process in the vanadium-stimulated oxidation of NADH.

Multivariate analysis of roentgenologic characteristics and risk factors for nonpalpable carcinoma of the breast.

Screening mammography improves carcinoma of the breast survival through early detection and treatment of nonpalpable, often noninvasive, carcinomas. Consideration of the roentgenologic characteristics of mammographic masses and calcifications in combination with risk factors of patients may improve the yield of spot localization breast biopsy. Risk factors solicited by questionnaire were correlated with the roentgenologic appearance and histopathologic factors of 482 specimens from spot localization breast biopsies (39 percent malignant). Masses with irregular contour (p < 0.001) and high density (p < 0.005) were associated with malignant tumors. Packed, coarse and round calcifications were associated with benignity (p < 0.001), whereas scattered, fine and mixed calcifications were associated with malignant tumors (p < 0.05). Malignant masses with smooth contour were significantly more likely to be associated with noninvasive histology. Patients found to have malignant tumors were significantly older than patients with benign lesions (58 versus 52 years, p < 0.001). Stepwise logistic regression was used to evaluate the relative usefulness of demographics and roentgenologic features in predicting benign and malignant pathology among masses and calcifications. Age and irregular contour were independent significant predictors of malignancy for masses. Age, round, coarse, packed or scattered calcifications were significant independent predictors of benignity among calcifications. The radiologist correctly predicted malignant pathology in 60 percent of the patients and benign pathology in 78 percent. Parity, age at menarche, age at first pregnancy, age at menopause, history of benign breast disease, history of carcinoma of the breast, family history of carcinoma of the breast, birth control pill exposure and smoking were not significantly associated with the diagnosis of malignant tumor. These results suggest that risk factors for carcinoma of the breast are insignificant for nonpalpable lesions because patients referred for needle localization are already selected for high risk. Roentgenologic patterns of masses are useful for predicting which lesions are invasive.

Spectrophotometric and ESR evidence for vanadium(IV) deferoxamine complexes.

Complexes of vanadium(IV), vanadyl, are reported to be formed with the trihydroxamic acid deferoxamine (H3DF+). One complex exhibits a reddish-violet color, with a major absorbance peak at 386 nm and a smaller peak at 520 nm. This complex is potentially useful for the microdetermination of vanadyl. The apparent molar absorptivity is 3.91 mM-1 cm-1, and the complex obeys Beer's law in the concentration range of 0.6-63 ppm. Electron spin resonance studies indicate the formation of two vanadyl complexes that are 1:1 in vanadyl and deferoxamine, but have two or three bound hydroxamate groups. ESR and spectrophotometric evidence indicate that the red, low pH form, involves an octahedral vanadium (4+) ion coordinated by three hydroxamate ligands. One of these hydroxamates is displaced by an oxygen at pH greater than 2.8 according to the following equilibria: VO2+ + H3DF+ in equilibrium with VIV(DF)2+ + H3O+, VIV(DF)2+ + H2O in equilibrium with VO(HDF)+ + H+, where pk2 = 2.8.

In vitro and in vivo effects of vanadate on K+-dependent phosphatase activities from subcellular fractions of brain, kidney and liver.

Inhibition of K+-dependent phosphatases by sodium orthovanadate was studied in the subcellular fractions of brain, kidney and liver from male Sprague-Dawley rats. The concentration required to produce an in vitro phosphatase inhibition of 50% ranged from a low of 0.2 microM in the kidney 900 X g fraction to a peak of 400 microM in the brain soluble fraction. The concentrations required to produce 50% inhibition occurred in the micromolar range for most fractions studied. Injection of sodium vanadate (i.p., 8 mg/kg) produced phosphatase inhibition in several of the fractions, but not as pronounced as the in vitro treatment. The results indicate that vanadate is a potent inhibitor of phosphatase activity in vitro, and may have similar potential in vivo.

Mucosal proctectomy and ileoanal anastomosis.

The classical surgical therapy of ulcerative colitis and familial polyposis has been total proctocolectomy and ileostomy. In order to avoid a cutaneous stoma and to achieve continence without disruption of gastrointestinal continuity, responding to a demand particularly among younger patients, a mucosal proctectomy in association with an ileoanal anastomosis has been devised. The addition of an ileal reservoir proximal to the anastomosis results in fewer bowel movements and a greater degree of continence. In our series of 70 cases, we have analyzed the normal roentgen anatomy of the ileoanal anastomosis and the proximal ileal reservoir and present our findings on plain film and contrast examinations. To assess patients postoperatively, the radiologist should be aware of the basic surgery involved and the normal roentgen anatomy resulting from this procedure.

Anterior cervical discectomy without fusion: a comparison with Cloward's procedure.

The antero-medial microsurgical disc or osteophyte removal without formal interbody fusion is a surgical alternative in the treatment of cervical discs causing radicular compression or cervical myelopathy. In the past 20 years 379 patients underwent anterior surgery, including 240 microdiscectomies without graft and 139 Cloward's dowel procedures. The long-term results of both procedures are compared in patients suffering from radicular compression, dominant myelopathy and radiculo-myelopathy. We found no statistically significant differences between the two methods treating three different conditions. The improvement rate in patients with soft and sequestrated discs is generally better compared to those with hard discs and spondylotic changes. Functional stability of the cervical spine is present in 92% of cases treated without interbody fusion immediately after surgery. A complete osseous fusion after a period of 6-12 months was found in 90% of Cloward procedures and in 81% of discectomy without graft. No definite correlation was found between the clinical improvement and the radiological results. According to our experience the Cloward's fusion procedure has no long-term advantages over discectomy without graft except in cases of severe myelopathy caused by multilevel ventral compression due to osteophytes. No permanent postoperative complication was encountered. Most of the treated patients returned to their previous activities.