An analysis of totally implantable central venous port system infections in an urban tertiary referral center

A frequent complication of central venous port systems (CVP) is infection (CVP-I), either local (CVP-LI) or a life-threatening blood stream infection (CVP-BSI). We examined the course of CVP-I including results of an antibiotic eradication attempt of CVP-BSI. We investigated adults with CVP-I from 2010 to 2018 who had to undergo port explantation or were treated by a combination of systemic antibiotics and antibiotic lock therapy (ALT). In nine years we diagnosed 206 CVP-I (CVP-LI: 52; CVP-BSI: 152). In 146 patients with CVP-I the port system was primary explanted, while 56 patients received antibiotics/ALT. 79% of Gram negative pathogens and 50% of coagulase negative staphylococci (CoNS) were eradicated. Failure of antibiotic treatment was more often associated with short time span since CVP implantation, neutropenia and polymicrobial infection. All patients with non-neoplastic disease survived, while 18/173 patients (10%) with underlying malignant disease had a fatal outcome in the same hospital stay.

Relationship of Apolipoprotein B Levels to the Number of Risk Factors for Metabolic Syndrome

Low-density lipoprotein cholesterol (LDL-C) is the primary target of lipid-lowering therapy. However, all lipoproteins containing apolipoprotein B (apo B) appear to be atherogenic. Preferred targets of therapy therefore may include either the cholesterol in all apo B-containing lipoproteins (non-high-density lipoprotein cholesterol [non-HDL-C]) or total apo B itself. Apo B can be measured by three methods: chemically, by nuclear magnetic resonance (NMR), and by immunoassay. This study compares the first two methods as a function of the number of metabolic risk factors in patients with metabolic syndrome. Plasma lipid, lipoprotein cholesterol, and apo B levels were measured in 274 adults with varying numbers of metabolic syndrome components. Low-density lipoprotein (LDL) particle sizes were measured by gel electrophoresis and by NMR. Total apo B was estimated chemically and by conversion of NMR lipoprotein particle number, assuming one apo B molecule per lipoprotein particle. As the number of metabolic syndrome components increased, apo B rose by both chemical and NMR methods, but by chemical methods, increases were in the triglyceride-rich fraction, whereas by NMR, they were in LDL. The correlation between total apo B measured by the two methods was only moderate (r = .73). Further, non-HDL-C was more highly correlated with total apo B measured chemically than either LDL-C or total apo B by NMR. Non-HDL-C correlates highly with total apo B in patients with metabolic syndrome and had advantages as a target of therapy over LDL-C or NMR apo B.

Oxandrolone enhances hepatic ketogenesis in adult men

BACKGROUND

Immediate administration of oxandrolone markedly increases hepatic lipase activity and reduces levels of plasma high-density lipoprotein.

RATIONALE FOR THE STUDY

We postulated that oxandrolone should increase hepatic lipase and that the nonesterified fatty acids generated would enhance hepatic ketogenesis during an extended fat tolerance test.

MAIN RESULTS

Eighteen men participated in the study using short-term administration of oxandrolone (10 mg/d) over a week. Subjects had evaluation of hepatic ketogenesis at baseline and after 7 days of administration of oxandrolone. Ketogenesis was assessed by measuring plasma levels of 3-hydroxybutyrate during a fat tolerance test. Oxandrolone increased fasting levels of 3-hydroxybutyrate by 70%, and increased the area under the curve during an FFT by 53% above pretreatment levels without affecting the areas under the curve for nonesterified fatty acids, glycerol, or triglycerides. Fasting 3-hydroxybutyrate levels correlated with nonesterified fatty acids and with triglycerides; however, there were no significant correlations with any other parameter.

CONCLUSIONS

This study shows that short-term administration of oxandrolone results in marked increases in hepatic ketogenesis. This finding is consistent with an increased influx of fatty acids into the liver secondary to lipoprotein lipolysis by increased hepatic lipase. However, the possibility cannot be ruled out that oxandrolone acts directly in the liver to stimulate fatty acid oxidation. Therefore, the observation of increased ketogenesis will require further studies to determine the molecular basis of the response.

Variability in postheparin hepatic lipase activity is associated with plasma adiponectin levels in African Americans

BACKGROUND

African Americans commonly have normal high-density lipoprotein cholesterol (HDL-C) and low triglyceride levels despite having insulin resistance and obesity. The higher than expected HDL-C levels are usually attributed to low levels of hepatic triglyceride lipase (HTGL) activity. Factors that regulate HTGL in African Americans are not well delineated.

METHODS

In the current study, HTGL activity was examined in relation to indices of body fat (body mass index [BMI] and waist circumference [WC]), insulin resistance (fasting plasma insulin and homeostasis model assessment of insulin resistance [HOMA-IR] index), and adipokines (adiponectin and leptin). Sixty-three African Americans (33 men, 30 women; median age 31 years, range 20-50 years; median BMI 28.6 kg/m2, range 19.7-54.7 kg/m2) had anthropometry and measurement of postheparin lipase activities (HTGL), plasma HDL-C, triglycerides, and plasma adiponectin.

RESULTS

HTGL correlated strongly with HDL-C (r = -.52, p < .0001) and adiponectin (r = -.49, p < .001). HTGL increased with BMI and WC (r = .297, p = .018 and r = .301, p = .016, respectively). Adiponectin correlated strongly with HDL-C (r = .50, p < .0001) and triglycerides (r = -.493, p < .001). From multiple regression models, 28% of HTGL variability among African Americans can be explained by adiponectin levels in combination with gender and 35% of HTGL is explained with HDL-C included in the model.

CONCLUSION

The data suggest that adiponectin is a significant metabolic concomitant of HTGL activity in African Americans.

The lipid-lowering effect of ezetimibe in pure vegetarians

Results of previous studies have shown that ezetimibe (10 mg/day) reduces LDL cholesterol in patients with mild hypercholesterolemia on a normal-cholesterol diet (dietary intake of 200-500 mg/day) by 16-22%. However, the LDL cholesterol-lowering effect of ezetimibe in subjects with an extremely low dietary cholesterol intake (vegetarians) has not been studied. We conducted a randomized, double-blind, placebo-controlled, two-phase crossover study in 18 healthy pure vegetarians to assess the effect of ezetimibe (10 mg/day) on plasma lipids, cholesterol absorption, and its synthesis. Treatment periods lasted 2 weeks each, with an intervening 2 week washout period. Fractional cholesterol absorption was determined using the continuous dual stable isotope feeding method. Mean dietary cholesterol intake in the pure vegetarians was extremely low and averaged 29.4 +/- 16.8 and 31.4 +/- 14.4 mg/day during the placebo and ezetimibe administration phases, respectively. Fractional cholesterol absorption during the placebo phase was 48.2 +/- 8.2% and was decreased by 58% during ezetimibe treatment to 20.2 +/- 6.2% (P < 0.001). This change in intestinal cholesterol absorption was followed by a significant reduction in LDL cholesterol of 17.3%. In individuals with extremely low dietary cholesterol intake, treatment with ezetimibe (10 mg/day) leads to a significant reduction of cholesterol absorption and a clinically relevant decrease of plasma LDL cholesterol, comparable to that of subjects with a normal dietary cholesterol intake. Thus, the lipid-lowering effect of ezetimibe is mediated mainly through a reduction of the absorption of endogenous (biliary) cholesterol.

Isotopomer spectral analysis of intermediates of cholesterol synthesis in patients with cerebrotendinous xanthomatosis

Four patients with cerebrotendinous xanthomatosis (CTX) and 2 healthy controls received a constant proximal intraduodenal infusion of 1- 13 C-acetate as a stable-isotope-labeled marker of sterol synthesis. One patient was treated with pravastatin (20 mg twice daily) and another patient with chenodeoxycholic acid (250 mg tid). Every hour, venous blood and duodenal samples were obtained. Stable-isotope enrichment of neutral and polar sterols in serum and bile was assessed by gas chromatography/mass spectrometry. Isotopomer spectral analysis was performed on cholesterol, lathosterol, Delta-8-cholesterol, methylsterol, and lanosterol. Stable-isotope labeling of cholestanol, bile acids, and bile alcohols was analyzed by assessing the change over time of the ratio of M + 3 to M + 0. Eleven hours after marker infusion, we found up to 50% newly synthesized lathosterol in serum and up to 80% in bile, with similar results for other cholesterol precursors. In cholesterol, stable-isotope labeling could be demonstrated in all study subjects with a more prominent labeling in bile than in serum. No stable-isotope labeling was detected in cholestanol. Only minor stable-isotope incorporation was detectable in polar sterols in some subjects. Therapy with pravastatin did not have any effect on fractional or absolute synthesis rates or on the concentrations of cholestanol or cholesterol precursors compared to untreated patients with CTX. In contrast, therapy with chenodeoxycholic acid markedly lowered the concentrations of cholestanol and cholesterol precursors, led to a disappearance of bile alcohols, and reduced absolute synthesis rates of lathosterol. Isotopomer spectral analysis proved to be a powerful method to assess the endogenous synthesis of cholesterol precursors in patients with CTX. Higher fractional synthesis in bile than in serum may be due to the size of the pools in bile vs serum. Cholestanol exhibits no marker uptake and is therefore probably synthesized from preformed cholesterol. Biliary cholesterol secretion in patients with CTX is decreased compared to healthy controls.