Human immunodeficiency virus (HIV)-1 infectivity requires actin-dependent clustering of host lipid raft–associated receptors, a process that might be linked to Rho guanosine triphosphatase (GTPase) activation. Rho GTPase activity can be negatively regulated by statins, a family of drugs used to treat hypercholesterolemia in man. Statins mediate inhibition of Rho GTPases by impeding prenylation of small G proteins through blockade of 3-hydroxy-3-methylglutaryl coenzyme A reductase. We show that statins decreased viral load and increased CD4+ cell counts in acute infection models and in chronically HIV-1–infected patients. Viral entry and exit was reduced in statin-treated cells, and inhibition was blocked by the addition of l-mevalonate or of geranylgeranylpyrophosphate, but not by cholesterol. Cell treatment with a geranylgeranyl transferase inhibitor, but not a farnesyl transferase inhibitor, specifically inhibited entry of HIV-1–pseudotyped viruses. Statins blocked Rho-A activation induced by HIV-1 binding to target cells, and expression of the dominant negative mutant RhoN19 inhibited HIV-1 envelope fusion with target cell membranes, reducing cell infection rates. We suggest that statins have direct anti–HIV-1 effects by targeting Rho.

Fructose makes up a significant proportion of energy intake in westernized diets; its increased consumption has paralleled the growing prevalence of obesity and metabolic syndrome over the past two decades. In the current study, we demonstrate that fructose administration (10% wt/vol) in the drinking water of rats reduces the trans-activating and trans-repressing activity of the hepatic peroxisome proliferator-activated receptor ␣ (PPAR␣). As a consequence, fructose decreases hepatic fatty oxidation and increases pro-inflammatory transcription factor nuclear factor B (NF-B) activity. These changes were not observed in glucose-administered rats (10% wt/ vol), although both carbohydrates produced similar changes in plasma adiponectin and in the hepatic expression of transcription factors and enzymes involved in fatty acid synthesis. Fructosefed, but not glucose-fed, rats were hyperleptinemic and exhibited increased tyrosine phosphorylation of the signal transducer and activator of transcription-3 (STAT-3) transcription factor, although they did not present a similar increase in the serine phosphorylation of nuclear STAT3. Thus, an impairment in the hepatic transduction of the leptin signal could be responsible for the observed alterations in PPAR␣ activity in fructose-fed rats. Because PPAR␣ activity is lower in human than in rodent liver, fructose ingestion in humans should cause even worse effects, which would partly explain the link between increased consumption of fructose and widening epidemics of obesity and metabolic syndrome. T he prevalence of metabolic syndrome and the risk for developing diabetes mellitus and cardiovascular disease is increasing worldwide. 1,2 Environmental factors (diet, physical activity), in tandem with predisposing genetic factors, may be responsible for this trend. Along with an increase in total energy consumption during recent decades, there has also been a shift in the types of nutrients, with an increased consumption of fructose, largely attributable to the greater intake of beverages containing high levels of fructose. 3 Once absorbed, dietary fructose is mainly taken up by the liver, promoting triacylglycerol synthesis and very low-density lipoprotein (VLDL) production. However, increases in liver fatty acid synthesis alone is not sufficient to account for such elevated triacylglycerol production. 4 Thus, those mechanisms underlying liver lipid metabolic derangements caused by high-fructose diets are not completely understood.The rat offers an effective model of human fructose metabolism. 5 A high-fructose diet in rats induces metabolic derangements similar to those found in the metabolic syndrome. 6 Nevertheless, although experimental designs using 50% to 60% of fructose in pelleted diets induce hypertriglyceridemia and a pronounced state of insulin resistance, 6,7 diets incorporating 10% wt/vol of fructose in drinking water induce hypertriglyceridemia and fatty liver without modifying plasma glucose and insulin levels. 8,9 Because high-carbohydrate diets and chronic hyperin...

We aimed to investigate the effect of atorvastatin (5 and 30 mg/kg/day for 2 weeks) on hepatic lipid metabolism in a well established model of dietary hypertriglyceridemia, the fructosefed rat. Fructose feeding (10% fructose in drinking water for 2 weeks) induced hepatic lipogenesis and reduced peroxisome proliferator-activated receptor ␣ (PPAR␣) expression and fatty acid oxidation. As a result, plasma and liver triglyceride and plasma apolipoprotein B (apoB) levels were increased. Atorvastatin, 5 and 30 mg/kg during 2 weeks, markedly reduced plasma triglyceride, but decreased apoB levels only at the highest dose tested (50%). Triglyceride biosynthetic enzymes and microsomal triglyceride transfer protein were unchanged, whereas liver PPAR␣, acyl-CoA oxidase, and carnitine palmitoyltransferase I mRNA levels (1.9-, 1.25-, and 3.4-fold, respectively) and hepatic fatty acid ␤-oxidation activity (1.25-fold) were increased by atorvastatin at 30 mg/kg. Furthermore, hepatic triglyceride content (45%) and plasma nonesterified fatty acids (NEFAs) (49%) were reduced. These results show for the first time that liver triglyceride increase in fructose-fed rats is linked to decreased expression of PPAR␣, which is prevented by atorvastatin treatment. The increase in PPAR␣ expression caused by atorvastatin was associated with reduced liver triglyceride and plasma NEFA levels.

Background Surgery is the main modality of cure for solid cancers and was prioritised to continue during COVID-19 outbreaks. This study aimed to identify immediate areas for system strengthening by comparing the delivery of elective cancer surgery during the COVID-19 pandemic in periods of lockdown versus light restriction. Methods This international, prospective, cohort study enrolled 20 006 adult (≥18 years) patients from 466 hospitals in 61 countries with 15 cancer types, who had a decision for curative surgery during the COVID-19 pandemic and were followed up until the point of surgery or cessation of follow-up (Aug 31, 2020). Average national Oxford COVID-19 Stringency Index scores were calculated to define the government response to COVID-19 for each patient for the period they awaited surgery, and classified into light restrictions (index <20), moderate lockdowns (20–60), and full lockdowns (>60). The primary outcome was the non-operation rate (defined as the proportion of patients who did not undergo planned surgery). Cox proportional-hazards regression models were used to explore the associations between lockdowns and non-operation. Intervals from diagnosis to surgery were compared across COVID-19 government response index groups. This study was registered at ClinicalTrials.gov , NCT04384926 . Findings Of eligible patients awaiting surgery, 2003 (10·0%) of 20 006 did not receive surgery after a median follow-up of 23 weeks (IQR 16–30), all of whom had a COVID-19-related reason given for non-operation. Light restrictions were associated with a 0·6% non-operation rate (26 of 4521), moderate lockdowns with a 5·5% rate (201 of 3646; adjusted hazard ratio [HR] 0·81, 95% CI 0·77–0·84; p<0·0001), and full lockdowns with a 15·0% rate (1775 of 11 827; HR 0·51, 0·50–0·53; p<0·0001). In sensitivity analyses, including adjustment for SARS-CoV-2 case notification rates, moderate lockdowns (HR 0·84, 95% CI 0·80–0·88; p<0·001), and full lockdowns (0·57, 0·54–0·60; p<0·001), remained independently associated with non-operation. Surgery beyond 12 weeks from diagnosis in patients without neoadjuvant therapy increased during lockdowns (374 [9·1%] of 4521 in light restrictions, 317 [10·4%] of 3646 in moderate lockdowns, 2001 [23·8%] of 11 827 in full lockdowns), although there were no differences in resectability rates observed with longer delays. Interpretation Cancer surgery systems worldwide were fragile to lockdowns, with one in seven patients who were in regions with full lockdowns not undergoing planned surgery and experiencing longer preoperative delays. Although short-term oncological outcomes were not compromised in those selected for surgery, delays and non-operations might lead to long-term reductions in survival. During current and future periods of societal restriction, the resilience of elective surgery systems requires strengthening, which might include...

There is controversy regarding whether fructose in liquid beverages constitutes another dietary ingredient of high caloric density or introduces qualitative changes in energy metabolism that further facilitate the appearance of metabolic diseases. Central to this issue is the elucidation of the molecular mechanism responsible for the metabolic alterations induced by fructose ingestion. Fructose administration (10% wt/vol) in the drinking water of Sprague-Dawley male rats for 14 days induced hyperleptinemia and hepatic leptin resistance. This was caused by impairment of the leptin-signal transduction mediated by both janus-activated kinase-2 and the mitogen-activated protein kinase pathway. The subsequent increase in activity in the liver of the unphosphorylated and active form of the forkhead box O1 nuclear factor, which transrepresses peroxisome proliferator-activated receptor ␣ activity, and a lack of activation of the adenosine monophosphate-activated protein kinase, led to hypertriglyceridemia and hepatic steatosis. These alterations are attributable to two key events: (1) F ructose makes up a significant proportion of energy in westernized diets, mainly due to the high intake of fructose-containing beverages. This situation has coincided with the growing prevalence of obesity and metabolic syndrome, recognized risk factors for cardiovascular diseases, over the past two decades. 1,2 Fructose in liquid diets induces hypertriglyceridemia to a greater extent than in solid diets. 3 A 10% dietary energy increase in