国产沉香化学成分的研究——Ⅲ.异白木香醇的结构测定和低沸点成分的分离与鉴定

自国产沉香(Aquilaria sinensis)[瑞香科(Thymeleaceae)植物]的挥发油中,经硅胶柱层析和离心薄层层析分离得到一新的倍半萜,命名为异白木香醇(isobaimuxinol),根据光谱(IR,¹HNMR,¹³CNMR,2 D-NMR和MS)分析确定其结构式为(Ⅰ)所示,并用X-光衍射晶体解析进一步确定了其立体化学。同时,也从该植物挥发油的低沸点部分分离得到四个已知化合物:苄基丙酮,对甲氧基苄基丙酮,茴香酸和β-沉香呋喃。这些化合物均为首次从该植物中得到。     

High-resolution MR imaging with local coils

We propose the following rules to govern the choice of local coils by the practicing radiologist: 1. Smaller coils permit smaller FOVs and better resolution. The coil should be as small as possible. 2. Match the ROS of the coil to the FOV, which will be determined by the anatomic region of interest. 3. For the case of a choice between surface coils or between a surface and a whole- or partial-volume coil, the anatomic region should lie on the high side of the crossover point. For the case of a choice among whole-volume coils, the smallest coil that surrounds the region of interest should be chosen. 4. Considerations in regard to the anatomic shape or the need to vary the position of the structure may alter the choice of coil from that obtained by S/N considerations alone.     

Microalbuminuria. Invalidity of simple concentration-based screening tests for early nephropathy due to urinary volumes of diabetic patients

OBJECTIVE: To evaluate the possibility of replacing quantitative albumin excretion rate (AER) measurements with rapid screening tests for microalbuminuria. RESEARCH DESIGN AND METHODS: Dipstick-negative specimens from 363 consecutive insulin-dependent diabetes mellitus (IDDM) and 46 non-insulin-dependent diabetes mellitus (NIDDM) patients from primary-care and hospital clinics (11% inpatients) within the district of Turku University Hospital were studied. Albumin concentrations and 12-h nightly excretion rates (N-AER) were measured by nephelometry (sensitivity 2 mg/L). RESULTS: An increased N-AER (greater than 15 micrograms/min) was seen in 99 IDDM (27%) and 15 NIDDM (33%) patients. The median urinary volume was 900 ml/12 h, with a maximum of 3000 ml. At the level of 20 mg albumin/L, the sensitivity to detect elevated N-AER was 70% among IDDM patients and 60% among NIDDM patients. At a lower albumin concentration of 10 mg/L, the sensitivities were increased to 91 and 87% in IDDM and NIDDM patients, respectively, but the specificities were reduced to 77 and 71%, respectively. CONCLUSIONS: To evaluate incipient nephropathy, we recommend quantitative measurements of N-AER from timed urine collections only. Dipstick tests are either insensitive or nonspecific.     

EMPHYSEMATOUS PYELONEPHRITIS RESPONDING TO MEDICAL THERAPY

We describe two type 2 diabetic patients with unilateral emphysematous pyelonephritis who responded to medical treatment alone. Escherichia coli was isolated in both patients. The presence of gas was confirmed early by ultrasound and CT scan of abdomen. Following treatment, good functional recovery was demonstrable in the affected kidneys by isotope renogram. We stress the need for early diagnosis of this condition and aggressive treatment with broad spectrum antibiotics.     

Multicenter study of atherosclerosis precursors in Finnish children--pilot study of 8-year-old boys

A multicentre study was launched to analyze the prevalence of risk factors for coronary heart disease and their determinants in Finnish infants, children and adolescents and to provide facts for the planning of intervention. The present report gives the results of the pilot study conducted among 264 8-year-old boys in 5 cities and corresponding rural areas in various parts of Finland. Data on eating habits were obtained from the parents by means of a questionnaire. Fasting serum specimens were analyzed in 249 subjects for cholesterol, HDL-cholesterol, triglycerides, and immunoreactive insulin (IRI). The fatty acid composition of serum lipids was determined in 244 subjects by gas chromatography. Soft vegetable margarine was used on bread by 29% of the boys in the rural and 46% in the urban areas. Low fat or skim milk, vegetables and fruit were used more often in the western than in the eastern part of the country. The mean values for serum lipids were as follows: cholesterol 5.0, HDL-cholesterol 1.4, and triglycerides 0.7 mmol/1. The proportion of linoleic acid in the fatty acid cholesterol ester fraction was higher than expected, 53%. The IRI values ranged from 2 to 55 (mean, antilog, 9.4) mU/l. The results served as background material for the main study of blood pressure, anthropometric, biochemical and socioeconomic variables.     

Blood glycated haemoglobin, serum fructosamine, serum glycated albumin and serum glycated total protein as measures of glycaemia in diabetes mellitus.

Blood glycated haemoglobin (HbAlc), serum fructosamine (FA), serum glycated albumin (GA), and serum glycated total protein (GTP) were determined in 61 subjects (19 pregnant women with gestational diabetes, 24 pregnant women with insulin-dependent diabetes mellitus [IDDM] and 18 nonpregnant subjects with IDDM). FA, GA, and GTP correlated with HbAlc similarly (r = 0.791, 0.816, and 0.794, respectively, p < 0.001). In a subgroup of 22 subjects data on blood glucose home monitoring was recorded and used for calculating mean blood glucose as an index of average glycaemia preceding sampling of the glycation products. Mean blood glucose levels preceding sampling of HbAlc by 2 months and FA, GA, or GTP by three weeks correlated significantly with HbAlc (r = 0.668, p < 0.001) and GA (r = 0.441, p < 0.05) whereas no significant correlation was found between mean blood glucose and FA (r = 0.003) or GTP (r = 0.252). In conclusion, such methods which measure specifically the non-enzymatic glycation of a single species of protein (i.e. FPLC for HbAlc and affinity chromatography for GA) are to be preferred for assessing glycaemia.     

Correlation of serum lipids with diabetes control in sulfonylurea-treated diabetic patients

The relationships between fasting blood glucose, glycosylated hemoglobin A1, and several lipid parameters were studied in 67 non-insulin-dependent diabetic patients (19 men, 48 women) being treated with tolbutamide, chlorpropamide, or glibenclamide. All patients were over 60 yr of age with a mean age of 76.4 +/- 6.7 yr (+/- SD). There were positive associations between fasting blood glucose and serum cholesterol, LDL cholesterol, and serum triglycerides. A strong association between total cholesterol and triglycerides was also evident. Diabetes control and HDL cholesterol did not correlate with each other. A weak inverse correlation existed between fasting blood glucose and the HDL cholesterol/total cholesterol ratio. HDL cholesterol concentrations were low in the diet- and drug-treated diabetic patients. No deleterious sulfonylurea effects on cholesterol, LDL cholesterol, and triglyceride concentrations or HDL cholesterol/total cholesterol ratio were noted.     

Decreased large artery distensibility in borderline hypertension is related to increased in vivo low-density lipoprotein oxidation

The present study tested the hypothesis that reduced arterial elasticity seen in hypertension is related to increased oxidation of LDL. Fifteen men with borderline hypertension (BHT), with blood pressure values classified as high normal (systolic blood pressure 130-140 mmHg or diastolic blood pressure 85-89 mmHg) were included. The control group comprised 22 men with normal blood pressure values (<135/80 mmHg) matched for age, body size and LDL-cholesterol level. Distensibility of aorta was measured using magnetic resonance imaging, and distensibility of the common carotid artery using ultrasound. Baseline LDL diene conjugation was used as a marker for ox-LDL. Aortic and carotid distensibilities were lower in the BHT men than in controls (1.4 +/- 0.6 vs. 1.9 +/- 0.6%/10 mmHg, p<0.05 for aortic distensibility; 2.9 +/- 0.9 vs. 3.6 +/- 0.6%/10 mmHg, p<0.05 for carotid distensibility). Ox-LDL was significantly higher in the BHT men than in controls (44 +/-15 vs. 28 +/- 8 micromol/L, p<0.01). In univariate analysis, ox-LDL associated with aortic distensibility (r=-0.43, p<0.05). In multivariate analysis, the differences in distensibilities between the groups disappeared when the values were adjusted for ox-LDL. These data show decreased arterial elasticity and increased LDL oxidation in young men with borderline hypertension, and suggest that oxidative modification of LDL particles may play a pathophysiological role in the development of reduced arterial distensibility in hypertension.