Glucocorticoids improve endothelial function in rheumatoid arthritis: a study in rats with adjuvant-induced arthritis.

To determine the effect of glucocorticoids (GCs) on endothelial dysfunction (ED) and on traditional cardiovascular (CV) risk factors in the adjuvant-induced arthritis (AIA) rat model. At the first signs of AIA, a high dose (HD) [10 mg/kg/day, intraperitoneally (i.p.), GC-HD] or low dose (LD) (1 mg/kg/day, i.p., GC-LD) of prednisolone was administered for 3 weeks. Endothelial function was studied in aortic rings relaxed with acetylcholine (Ach) with or without inhibitors of nitric oxide synthase (NOS), cyclooxygenase 2 (COX-2), arginase, endothelium derived hyperpolarizing factor (EDHF) and superoxide anions ( O2-°) production. Aortic expression of endothelial NOS (eNOS), Ser1177-phospho-eNOS, COX-2, arginase-2, p22phox and p47phox was evaluated by Western blotting analysis. Arthritis scores, blood pressure, heart rate and blood levels of cytokines, triglycerides, cholesterol and glucose were measured. GC-HD but not GC-LD reduced arthritis score significantly and improved Ach-induced relaxation (P < 0·05). The positive effect of GC-HD resulted from increased NOS activity and EDHF production and decreased COX-2/arginase activities and O2-° production. These functional effects relied upon increased phospho-eNOS expression and decreased COX-2, arginase-2 and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase expression. Despite the lack of effect of GC-LD on ED, it increased NOS and EDHF and down-regulated O2-° pathways but did not change arginase and COX-2 pathways. GC-HD increased triglycerides levels and blood pressure significantly (P < 0·05). Both doses of GCs decreased to the same extent as plasma interleukin (IL)-1ß and tumour necrosis factor (TNF)-α levels (P < 0·05). Our data demonstrated that subchronic treatment with prednisolone improved endothelial function in AIA via pleiotropic effects on endothelial pathways. These effects occurred independently of the deleterious cardiometabolic effects and the impact of prednisolone on systemic inflammation.

[Devices for the reduction of N2O pollution during conscious sedation in dentistry]. / Dispositivi per la riduzione dell'inquinamento da N2O durante la sedazione cosciente in odontoiatria.

We considered data of environmental monitoring during three working days in a dentist's office who habitually employs nitrous oxide (N2O): conscious sedation is used to alleviate anxiety and to diminish or eliminate dental pain. Three different nose masks were tested to determine influence on environmental pollution by N2O. The study shows that the levels of N2O always remains low with the use of proper dental procedures, although the chose of the type of nose mask can further diminish air pollution and the exposure of dental personnel.

Atypical cells in radiation dermatitis express factor XIIIa.

Dendritic cells that express factor XIIIa are present in the normal dermis and are increased in a variety of pathologic conditions. Atypical dermal cells are often seen in biopsy specimens of skin that has been previously irradiated. We sought to determine whether the atypical dermal cells in chronic radiation dermatitis express factor XIIIa. We employed standard immunohistochemical techniques with antibodies to factor XIIIa and CD34 to study 16 biopsy samples showing changes of radiation dermatitis. All cases showed diffuse positive cytoplasmic staining of atypical dermal cells with antibody to factor XIIIa. Of 16 cases, 10 showed focal staining of dermal cells with antibody to CD34, but this antibody did not react with most of the atypical dermal cells. We conclude that the majority of atypical dermal cells in radiation dermatitis are derived from dermal dendritic cells which express factor XIIIa.

Validity of clinic biopsy specimens in classifying histopathologic characteristics of recurrent nasopharyngeal carcinoma.

OBJECTIVE: To evaluate nasopharyngeal carcinoma resection specimens for heterogeneity of histologic patterns to determine if preoperative histologic characteristics of the clinic biopsy specimen are representative of the entire lesion. The null hypothesis is that clinic biopsy specimens are not necessarily representative. DESIGN: Preoperative clinic biopsy specimens were measured to calculate their average size. Resection specimens were then sectioned and evaluated in increments corresponding to this size. Each of these increments was then histologically classified according to the World Health Organization (WHO) criteria. This classification of the preoperative biopsy specimens was compared with that of the resection specimen as a whole. SETTING: University referral center. PATIENTS: Twenty-six consecutive patients with recurrent nasopharyngeal carcinoma who underwent surgical resection. Radiation therapy failed in all patients. MAIN OUTCOME MEASURE: The presence or absence of WHO histologic heterogeneity in the nasopharyngectomy specimen was recorded. Disparity between preoperative clinic biopsy and resection specimens was recorded. RESULTS: The mean clinic biopsy specimen size was 13.9 mm2 or less than 1% of the available surface area of the nasopharynx. Of 26 resection specimens classified in 5 increments of this size, 15 (57.7%) were a single WHO type, and 11 (42.3%) were found to be mixtures of WHO types I, II, and III. Of 16 cases with preoperative biopsy specimens available, 4 (25%) were a different WHO classification than their corresponding resection specimen. CONCLUSIONS: Most clinic biopsy specimens were representative of their corresponding tumor resection specimens in their entirety; however, tumor heterogeneity is such that some biopsy specimens will not be representative. This finding may interfere with WHO classification data determined on the basis of clinic biopsy specimens and hence confound any meaningful data on treatment outcomes. It is recommended then that multiple nasopharyngeal biopsy specimens be obtained from disparate areas of the lesion and each subjected to independent histopathologic review.

MRI of radiation-induced prostate sarcoma.

A patient with a history of pelvic radiation therapy for seminoma presented with a prostatic tumor, which appeared predominantly of high signal intensity on T2-weighted magnetic resonance images; low-signal-intensity tissue also extended to the pelvic sidewall. At surgical pathology, the tumor was determined to be radiation-induced sarcoma of the prostate, and the extraprostatic tissue was postradiation fibrosis.

Characterization of atherosclerosis with a 1.5-T imaging system.

It is shown that a conventional 1.5-T magnetic resonance (MR) imaging system can help characterize some of the key components of atherosclerotic plaque ex vivo. Fresh human aorta with atheromata was suspended in solutions of agarose and manganese chloride and heated to body temperature. The specimens were imaged with modified Dixon and projection-reconstruction imaging sequences. The specimens were then examined histologically to obtain direct correlation between images, spectra, and histologic characteristics. The results show that vessel wall and plaque components can be identified by means of their MR characteristics and correlated with their histologic appearance. The authors were able to identify normal vessel wall components, such as adventitial lipids and smooth muscle. They were also able to identify and localize plaque components such as fibrous tissue, calcification, lipids, and possible areas of hemorrhage and hemosiderin deposition.