An unexpected tumor causing right ventricular obstruction

A 58‐year‐old male with a history of a soft tissue sarcoma in remission presented with a 2 weeks history of progressive dyspnea. Transthoracic echocardiography showed right ventricular dilation; right ventricular systolic pressure (RVSP) of 110 mm Hg, and a lobulated mass in the right ventricular outflow tract (RVOT) causing obstruction. Microbubble contrast was administered showing perfusion within the mass, which suggested malignancy. A CT pulmonary angiogram (CTPA) confirmed the presence of the mass in the RVOT without evidence of pulmonary embolism. This case demonstrates the importance of the multimodality imaging approach for the differential diagnosis of masses in the RVOT.     

Surgical bacterial infections and antimicrobial susceptibility patterns at Lilongwe Central Hospital

A cross sectional study was done between October 1999 and February 2000 to determine antimicrobial susceptibility patterns of consecutive bacterial isolates of 102 clinical samples among surgical in-patients at Lilongwe Central Hospital (LCH), Malawi. Antimicrobial susceptibility was determined using comparative disc diffusion techniques. 83 (81.4%) samples were culture positive for bacterial growth while 19 (18.6%) grew nothing. Of the 93 culture positive specimens, Staphylococcus aureus was the predominant organism 43(51.8%) followed by Proteus species 8(9.6%) and E. coli 7(8.4%). Overall, 98.6% of all isolates tested against ciprofloxacin were susceptible, and against gentamicin and flucloxacin were 84.8% and 66.7% respectively. 59.3% of isolates tested against chloramphenicol were resistant. We recommend a review on the use of chloramphenicol as first-line antimicrobial therapy among surgical in-patients at Lilongwe Central Hospital. We also recommend restricted use of antimicrobials so as to minimise development of drug resistance. Periodic susceptibility studies are necessary to guide judicious use of antibiotics.     

Stenting beim akuten Schlaganfall

Eine hämodynamische Insuffizienz aufgrund von Pseudookklusionen oder Verschlüssen der A. carotis interna ist eine seltene Ursache des akuten Schlaganfalls. Eine akute Revaskularisation des Gefäßes kann die zerebrale Perfusion wieder herstellen.Diese retrospektive Studie zeigt, dass eine akute Stentimplantation mit proximalen und distalen Protektionssystemen bei Patienten mit Verschluss oder Pseudookklusion der A. carotis interna und unzureichender Kollateralisation technisch möglich ist und weitere hämodynamisch bedingte Infarkte verhindern kann. Demgegenüber steht eine erhöhte Rate von Reperfusionssyndromen mit intrakraniellen Blutungen; eine periinterventionelle intensivmedizinische Überwachung und Einstellung des Blutdrucks auf normotone Werte wird empfohlen.     

d-生物素的立体专一性全合成研究

对confaione的d-生物素(1)全合成进行了改进,从半胱氨酸计算,总收率3.7%。5与4-溴代三苯膦丁酸甲酯进行Wittig-Schlosser缩合反应可立体专一性地转化成反式-烯(6)。以叠氮三甲基硅烷代替叠氮化锂亲核进攻9分子中C3-溴原子,可显著地提高顺式-叠氮内酰胺10的收率。     

侵及眶部脑肿瘤的临床特征与显微手术处理

目的 研究侵及眶部的脑肿瘤临床特征与显微外科手术治疗效果。方法 对58例本病经临床分析与影像学检查而获诊断，采用不同手术入路及显微外科技术切除肿瘤。全组病例中，肿瘤位于前颅凹50例，中颅窝8例，均侵及眶腔。其中39例（67．2％）有头痛、头晕等颅内压增高表现，54例（93．1％）出现视器症状。结果 本组46例肿瘤（79．3％）获手术全切除，12例（20．7％）为次全切除，无死亡。对48例经信访或门诊随访6个月-9年（平均3．6年），39例（81.3％）恢复满意，余9例（18．7％）有不同程度后遗症。结论 脑肿瘤侵及眶部多以视器改变为主要临床表现。采取不同手术入路、以显微外科技术切除本类肿瘤，预后良好。     

Quality of life and vocal health of teachers

OBJECTIVE: To evaluate aspects of teachers' quality of life and describe associated factors to their vocal health. METHODS: A sample comprising 128 high school teachers from four state schools in the city of Rio Claro, Southeastern Brazil, was studied in 2002. The World Health Organization Quality of Life/bref and Voice-Related Quality of Life questionnaires were applied and there were calculated the averages, standard deviation values for the first questionnaire scores and the self-evaluation question of the Voice-Related Quality of Life. The Wilcoxon's test was used to compare teachers' genders; the Kruskal-Wallis's test was used to compare schools and Spearman's correlation coefficient and t-test were performed to assess the association between the domains of quality of life, the vocal self-evaluation question and age, and the number of working shifts by a teacher. RESULTS: Most teachers evaluated their voice as good (42.2%) and the mean score of the quality of life questionnaire was 66, with the highest scores in the domain of social relations, and the lowest ones in the environment domain. The most affected aspects were leisure opportunities, financial conditions, work environment and access to information. The number of hours worked by a teacher had a positive significant correlation with vocal self-evaluation. There were no significant differences between genders. There were significant differences in the physical domain when comparing schools. CONCLUSIONS: Although teachers showed to be reasonably satisfied with their vocal and life quality, they showed misperceptions of their health disorder process and evidenced neglected aspects of life quality and health needs that may compromise teachers' voice/vocal health.     

Inadequate aldosterone response to hyperkalemia during angiotensin converting enzyme inhibition in chronic renal failure

To assess the mechanism involved in hyperkalemia during angiotensin converting enzyme inhibition with captopril in chronic renal failure, captopril, 150 mg/day, was administered to 16 patients with hypertension with plasma creatinine levels between 1.6 and 12.4 mg/dl. After 4 weeks of therapy, plasma potassium levels increased from 3.9 +/- 0.1 to 5.5 +/- 0.2 mEq/L (P less than 0.001) and the final plasma potassium levels correlated with plasma creatinine levels (r = 0.67; P less than 0.01). In six patients with plasma creatinine levels greater than or equal to 3 mg/dl, aldosterone excretion decreased after 4 weeks of captopril, from 7.5 +/- 3.1 to 1.8 +/- 0.5 micrograms/24 hr, whereas plasma renin activity increased from 0.6 +/- 0.2 to 4.4 +/- 1.1 ng/ml/hr (P less than 0.05). This was associated with increases in plasma potassium levels from 3.9 +/- 0.2 to 5.4 +/- 0.4 mEq/L (P less than 0.005) and a significant reduction in fractional excretion of potassium from an average of 34% to 25%. No significant changes in plasma creatinine levels were observed during therapy. There was a significant positive correlation between aldosterone excretion and the potassium excretion fraction (r = 0.53; P less than 0.01). Increases in plasma potassium levels were not able to increase aldosterone excretion, although the greater the plasma potassium level attained, the smaller the reduction in aldosterone excretion (r = 0.47; P less than 0.05). Our results indicate that adequate aldosterone production is essential to preserve potassium homeostasis in chronic renal failure. Moreover, angiotensin II appears necessary for an adequate aldosterone response to potassium stimulation.     

Attentional systems in target and distractor processing: a combined ERP and fMRI study

The interplay of "top-down" and "bottom-up" regulated mechanisms is of particular relevance for the rapid (re-)focusing of attention to environmental changes. The purpose of the study was to explore the differential contributions of frontoparietal attentional networks involved in top-down and stimulus-driven processing to the detection of "target" and "distractor" events in a visual three-stimulus oddball paradigm. Thirteen healthy subjects underwent separate event-related potential (ERP) and whole-brain functional magnetic resonance imaging (fMRI) measurements during the oddball task. The targets, which were difficult to detect, elicited a classical posterior P3b whereas the distractor stimuli were followed by a centro-frontal P3a ERP. The fMRI data showed activation of the temporoparietal junction (TPJ) bilaterally and right prefrontal cortex associated with both the target and distractor conditions. This network has previously been described as an attentional system that is predominantly stimulus driven and that responds to rare events. Furthermore, target processing produced bilateral perisylvian activity, which has been related to the "retrieval mode". Processing of the distractors activated the frontal eye fields (FEFs) and bilateral superior parietal cortex, areas engaged in attention switching and voluntary allocation of attention. Additional left prefrontal activation suggested an involvement of the cortical system for working memory encoding. Our results thus demonstrate that distractor and target processing engage a common neuronal system for the detection of rare events, but also task-specific subsystems related to attention and memory processes.