灵芝生物碱甲和乙的合成

灵芝为担子菌类多孔菌科灵芝属植物的子实体。人工培养的有赤芝、紫芝、薄盖灵芝和树舌等。灵芝是我国广泛流传的珍贵药物之一。近年来,对于灵芝的临床疗效和药理作用做了多方面的研究,证明对慢性气管炎、慢性肝炎、冠心病、白细胞减少症、慢性克山病和神经衰弱等都有一定的疗效,特别是对神经系统和肝脏功能具有调节作用。深层培养的薄     

Measuring hospital mortality rates: are 30-day data enough? Ischemic Heart Disease Patient Outcomes Research Team.

OBJECTIVE. We compare 30-day and 180-day postadmission hospital mortality rates for all Medicare patients and those in three categories of cardiac care: coronary artery bypass graft surgery, acute myocardial infarction, and congestive heart failure. DATA SOURCES/COLLECTION. Health Care Financing Administration (HCFA) hospital mortality data for FY 1989. STUDY DESIGN. Using hospital level public use files of actual and predicted mortality at 30 and 180 days, we constructed residual mortality measures for each hospital. We ranked hospitals and used receiver operating characteristic (ROC) curves to compare 0-30, 31-180, and 0-180-day postadmission mortality. PRINCIPAL FINDINGS. For the admissions we studied, we found a broad range of hospital performance when we ranked hospitals using the 30-day data; some hospitals had much lower than predicted 30-day mortality rates, while others had much higher than predicted mortality rates. Data from the time period 31-180 days postadmission yield results that corroborate the 0-30 day postadmission data. Moreover, we found evidence that hospital performance on one condition is related to performance on the other conditions, but that the correlation is much weaker in the 31-180-day interval than in the 0-30-day period. Using ROC curves, we found that the 30-day data discriminated the top and bottom fifths of the 180-day data extremely well, especially for AMI outcomes. CONCLUSIONS. Using data on cumulative hospital mortality from 180 days postadmission does not yield a different perspective from using data from 30 days postadmission for the conditions we studied.     

Ocular MR imaging and spectroscopy: an ex vivo study

Six eyes, freshly enucleated because of choroidal melanoma, were imaged on a 1.4-T superconducting magnetic resonance (MR) imaging system, and relaxation times were calculated for various parts of the eye. Unfixed fresh tissue samples were obtained for nuclear magnetic resonance spectroscopy (NMRS) on a variable-field (0.19-1.4 T) resistive unit. Detailed ocular anatomy was demonstrated. The NMRS relaxation times correlated with the MR imaging intensity patterns. The sensitivity of MR imaging to states of hydration provides an excellent window for appreciation of ocular anatomy.     

Athlete shoulder injuries: CT arthrographic findings

Forty-three professional and amateur athletes with persistent shoulder pain that interfered with their sports activities were evaluated by computed tomographic (CT) arthrography. In 19 patients, glenohumeral instability (14 anterior, two posterior, three multidirectional) was diagnosed with CT arthrography based on the simultaneous presence of labral and capsular lesions. The findings were crucial in establishing the diagnosis of instability in six patients in whom the condition was not suggested or could not be confirmed clinically. Another significant injury consisted of labral lesions not associated with glenohumeral instability. These tears often involved the anterior and parasuperior segments of this structure. Other, less frequently detected lesions included segmental labral enlargement and several labra with abnormal orientation (everted labrum). Early onset of degenerative disease was present in many athletes, especially those with a long history of sports activity. CT arthrographic findings were correlated with arthroscopic or surgical results in 19 patients.     

No evidence of frequent human immunodeficiency virus type 1 infection in seronegative at-risk individuals

The possible existence of human immunodeficiency virus type 1 (HIV-1) infection in asymptomatic seronegative at-risk individuals was investigated in a prospective study of 55 seronegative high-risk individuals (42 homosexual men and 13 heterosexual individuals) and 32 seronegative hemophiliacs treated with factor VIII or IX concentrates before viral inactivation by heat treatment and systematic screening of blood donations. Tests used include the polymerase chain reaction assay with three primer pairs (one in the gag region and two in the pol region) and tests for serum p24 antigen, anti-nef serology (Western blot), and five biologic markers frequently altered by HIV infection (CD4 lymphocyte count, serum beta 2-microglobulin and neopterin concentration, and serum IgG and IgA concentration). Although 91 of 92 HIV-1-seropositive persons were positive in testing with at least one primer pair, no positive result was observed in seronegative at-risk individuals or in 117 seronegative low-risk controls. No nef antibody was found in seronegative at-risk individuals or seronegative controls, but 44 (47%) of 92 HIV-1-seropositive persons had nef antibodies. These findings do not support the existence of frequent HIV-1 infection in seronegative at-risk individuals.