Plasma lipoprotein levels and the prevalence of hyperlipoproteinemia in a Canadian working population

The lipids and lipoproteins — cholesterol (C), triglyceride (TG) and high-density, low-density, very-low-density and sinking pre-β-lipoprotein cholesterol (HDL-C, LDL-C, VLDL-C and SPB-C) — in plasma samples from 1620 fasting white adults and children from the Toronto—Hamilton area were analysed. The mean concentration of HDL-C was about 45 mg/dl in men and about 60 mg/dl in women, and the levels were constant throughout adult life in both sexes. Boys had higher mean HDL-C levels than men, but girls had lower mean HDL-C levels than women. Mean LDL-C levels, like total C levels, increased with age, from about 87 mg/dl in boys to 136 mg/dl in men, and from about 91 mg/dl in girls to 145 mg/dl in women. The mean levels of VLDL-C followed the TG patterns for age and sex, rising from about 7 mg/dl in boys to 26 mg/dl in men, and from about 11 mg/dl in girls to 19 mg/dl in women. SPB-C was detectable visually in 39% of the population and with the aid of densitometry in 54%; the levels were not related to age, sex or oral contraceptive use, and the median level was 3 mg/dl.

Prevalence estimates of hyperlipoproteinemia showed that type IV was the most common, and it was found more than three times as often in men as in women. This was in part due to the customary use of plasma TG cut-off points that do not reflect the large difference in TG levels between males and females. Type IIA hyperlipoproteinemia was found in about 2% of the adults and type IIb in a further 1%. Types I, III and V were all rare. The prevalence of types II and IV hyperlipoproteinemia was four times greater in women using oral contraceptives than in nonusers in the same age range.

     

Plasma high-density lipoprotein cholesterol level. Influence of risk factor intervention.

Determinants of circulating high density lipoproteins (HDL) were sought in 301 men studied during a year of participation in a coronary prevention program. Mean plasma HDL-cholesterol concentration rose by 2.8 mg/dl (6%) in the group receiving multifactor intervention, but the change did not differ significantly from that in the comparison group. Larger changes in both directions were seen in many individuals. Multiple regression analysis of these changes indicates that increased plasma HDL levels occur when plasma triglyceride level is decreased, cigarette smoking is reduced, and habitual alcohol intake is increased. Increases in the concentration of HDL-cholesterol also tended to accompany adherence to the fat-controlled diet, reduction in LDL-cholesterol level, and loss of body weight. Conventional coronary prevention programs are unlikely to have an adverse influence on this new, risk-lowering factor.     

Incidence of coronary heart disease and lipoprotein cholesterol levels. The Framingham Study

The first report from the Framingham Study that demonstrated an inverse relationship between high-density lipoprotein cholesterol (HDL-C) and the incidence of coronary heart disease (CHD) was based on four years of surveillance. These participants, aged 49 to 82 years, have now been followed up for 12 years, and this report shows that the relationship between the fasting HDL-C level and subsequent incidence of CHD does not diminish appreciably with time. Since a second measurement of HDL-C is available eight years after the initial determination, the relationship of HDL-C measurements on the same subjects at two points in time is examined. This second HDL-C measurement is also used in a multivariate model that includes cigarette smoking, relative weight, alcohol consumption, casual blood glucose, total cholesterol, and blood pressure. It is concluded that even after these adjustments, nonfasting HDL-C and total cholesterol levels are related to development of CHD in both men and women aged 49 years and older. Study participants at the 80th percentile of HDL-C were found to have half the risk of CHD developing when compared with subjects at the 20th percentile of HDL-C.     

Hypocalcemic effect of aminoglycoside antibiotics in the dairy cow.

The effect of the parenteral administration of aminoglycoside antibiotics on the blood calcium concentration in dairy cows was investigated. Gentamicin was tested in vitro in blood drawn from cows, dihydrostreptomycin was tested in nonlactating cows and neomycin was tested in postpartum cows. The total and bound calcium fractions were significantly reduced by all three antibiotics. No change occurred in the unbound calcium fractions. Caution is advised in the use of these drugs in postpartum cows, especially those with a history of milk fever.     

Antimicrobial drug resistance of Staphylococcus aureus in dairy products

Objective

To evaluate the prevalence of multidrug resistant Staphylococcus aureus (S. aureus) in dairy products.

Methods

Isolation and identification of S. aureus were performed in 3 dairy-based food products. The isolates were tested for their susceptibility to 5 different common antimicrobial drugs.

Results

Of 50 samples examined, 5 (10%) were contaminated with S. aureus. Subsequently, the 5 isolates were subjected to antimicrobial resistance pattern using five antibiotic discs (methicillin, vancomycin, kanamycin, chloramphenicol and tetracycline). Sample 29 showed resistance to methicillin and vancomycin. Sample 18 showed intermediate response to tetracycline. The other samples were susceptible to all the antibiotics tested.

Conclusions

The results provide preliminary data on sources of food contamination which may act as vehicles for the transmission of antimicrobial-resistant Staphylococcus. Therefore, it enables us to develop preventive strategies to avoid the emergence of new strains of resistant S. aureus.     

The effect of fenfluramine on glucose tolerance, insulin, lipid and lipoprotein levels in patients with peripheral arterial disease

An investigation has been undertaken to determine the effects of fenfluramine on glucose tolerance, insulin, fasting lipid and lipoprotein levels, in a series of twenty-five patients suffering from peripheral arterial disease.     

The effect of digital rectal examination on prostate-specific antigen levels.

OBJECTIVE--To identify the effect of digital rectal examination (DRE) on serum prostate-specific antigen (PSA) levels. DESIGN--A prospective trial before and after DRE. SETTING--Multicenter outpatient screening program. PATIENTS--A total of 2754 healthy men aged 40 years and older who presented to a prostate cancer screening program and consented to two phlebotomies. MAIN OUTCOME MEASURE--Changes in serum PSA levels after DRE. RESULTS--Patients were divided into four groups based on their initial serum PSA levels. The levels were chosen based on previous studies that showed different incidences of prostate cancer within these groups. The two groups with the lowest initial PSA values (0.1 through 4 micrograms/L and 4.1 through 10 micrograms/L) were found to have statistically insignificant changes in the serum PSA levels after DRE. The group with initial PSA levels of 10.1 through 20 micrograms/L had increases in serum PSA values that showed a trend toward statistical significance. The group with initial PSA levels of greater than 20 micrograms/L had statistically significant increases in serum PSA values after DRE. The alterations in serum PSA levels in the two groups with the highest PSA values were not clinically important as the patients' clinical treatment was not altered. CONCLUSIONS--No clinically important effects on serum PSA levels were noted after DRE.     

辛基酚对雌性大鼠生殖能力的影响

目的:研究环境雌激素辛基酚(octylphenol,OP)对雌性大鼠生殖能力的影响。方法:将50只初成年雌性大鼠随机分为5组,其中设阴性对照和己烯雌酚(30μg/kg)阳性对照各1组。隔日染毒60d后与未染毒的雄性成年大鼠交配,研究OP对母鼠的受孕、分娩及子代发育的影响。结果:随着染毒剂量的升高,每窝平均产仔量下降。低剂量组子鼠平均出生体重与对照组相比差异无统计学意义(P>0.05),中、高剂量组与对照组相比差异有统计学意义(P<0.05和P<0.01)。断乳后,各剂量组母鼠的体重和卵巢、子宫、肝脏、肾脏、脑体系数差异均无统计学意义(P>0.05)。结论:在本实验剂量下,随着母鼠交配前OP接触剂量的升高,子鼠的出生体重有降低的趋势。     

The effect of sulphonylurea therapy on serum total cholesterol and high density lipoprotein cholesterol.

A study was conducted on 50 cases comprising 25 patients of non-insulin dependent diabetes mellitus and 25 age and sex matched normal individuals. The diabetic state of the patients was controlled by glibenclamide, a sulphonylurea. The levels of serum total cholesterol and high density lipoprotein cholesterol were measured at the start and 15 and 30 days after glibenclamide therapy. There was a significant (p < 0.001) decrease in the levels of serum total cholesterol from initial 222.96 +/- 31.04 mg% to 218 +/- 28.99 mg% after 15 days and to 211.8 +/- 28.42 mg% after 30 days of therapy. In no case there was increase in serum total cholesterol level. There was a significant (p < 0.001) increase in the levels of serum high density lipoprotein cholesterol from initial 20.96 +/- 4.59 mg% to 21.8 +/- 4.78 mg% after 15 days to 23.72 +/- 5.07 mg% after 30 days of glibenclamide therapy and no case showed a fall in serum high density lipoprotein cholesterol level. This favourable alteration in serum total cholesterol and high density lipoprotein cholesterol was observed in patients of non-insulin dependent diabetes mellitus having ischaemic heart disease as well.     

Decrease in plasma high-density lipoprotein cholesterol levels at puberty in boys with delayed adolescence. Correlation with plasma testosterone levels

A three-phase study tested the hypothesis that the decrease in the high-density lipoprotein cholesterol (HDL-C) level observed in boys at puberty is related to an increase in the plasma testosterone concentration. In phase I, 57 boys aged 10 to 17 years were categorized into four pubertal stages based on clinical parameters and plasma testosterone levels. These four groups showed increasing plasma testosterone values and decreasing HDL-C levels. In phase II, 14 boys with delayed adolescence were treated with testosterone enanthate (100, 200, and 200 mg/mo, respectively, for three months). Plasma testosterone levels during therapy were in the adult male range. Levels of HDL-C decreased by a mean of 7.4 mg/dL (0.20 mmol/L) and 13.7 mg/dL (0.35 mmol/L), respectively, after the first two doses. In phase III, 13 boys with delayed adolescence demonstrated increasing plasma testosterone levels and decreasing HDL-C levels (-12.0 mg/dL [-0.30 mmol/L]) during spontaneous puberty. Levels of HDL-C and apolipoprotein A-1 were correlated during induced and spontaneous puberty. Testosterone should be considered a significant determinant (not necessarily directly causal) of plasma HDL-C levels during pubertal development.     

Plasma lipids and lipoprotein patterns in angiographically graded atherosclerosis of the legs and in coronary heart disease.

The prevalence and type of plasma lipoprotein abnormalities were determined in 114 French-Canadian patients with angiographically proven peripheral vascular disease (PVD). The severity of atherosclerosis was positively correlated with plasma triglyceride concentration, especially in the younger patients (r = 0.29, P less than 0.05), and (not significantly) with plasma cholesterol concentration. Of the risk factors believed to predispose individuals to atherosclerosis, cigarette smoking was the most frequently found in the PVD patients (72.8%), especially among the men. Combination of two or more risk factors was the rule. Findings were compared with those in 114 patients who had undergone coronary angiography for suspected coronary heart disease (CHD). The CHD patients were, on average, younger by 10 years. Hyperlipidemia was present in 58.8% of CHD patients, compared with 43.9% of PVD patients. A far higher proportion of CHD patients showed the type II plasma lipoprotein pattern (24.6% v. 7.9%), although the type IV pattern was more common in both groups (31.6% and 28.9%, respectively). A high proportion of all patients (56.1% with PVD and 41.2% with CHD) showed a normal lipoprotein pattern on paper electrophoresis.