Francesco Minerva

T16189C mitochondrial DNA variant is associated with metabolic syndrome in Caucasian subjects

OBJECTIVES Different nuclear genes are thought to be involved in the regulation of the complex phenotype of metabolic syndrome (MS) and their number is increasing. A mutation in mitochondrial DNA (mtDNA), T4291C in transfer RNA isoleucine (tRNAile), has been associated with MS in a large American family. In addition, a mtDNA T16189C variant, already known to be associated with insulin resistance and type 2 diabetes mellitus in Caucasians, seems to underlie susceptibility to MS in the Chinese population. Our aim was to verify the T4291C and T16189C variants in subjects affected by different phenotypes of MS. METHODS Seventy patients with MS and 35 healthy individuals were investigated for the presence of the mtDNA variants by polymerase chain reaction-restriction fragment length polymorphism analysis. RESULTS The T4291C variant was absent in patients and in controls. The T16189C variant was more frequent in patients with MS than in control subjects (21.4% versus 5.7%, P<0.04) and was associated with hypertension (P=0.01), waist circumference (P=0.02), body mass index (P=0.009), visceral fat thickness (P=0.04), homeostasis model assessment (P=0.03), and the number of MS diagnostic criteria (P=0.01). CONCLUSION The mtDNA T16189C variant is associated with MS and its different clinical expressions. Prospective studies are warranted to establish the clinical relevance of this association.

Liver Function as Assessed by Breath Tests in Patients With Hepatocellular Carcinoma

BACKGROUND Little is known on hepatic function in patients with hepatocellular carcinoma (HCC). Metabolic changes were explored in HCC patients before/after nonsurgical therapy. MATERIALS AND METHODS HCV-related Child-Pugh A cirrhotic patients with (n = 37) or without HCC (n = 14) and healthy controls (n = 23) were enrolled. Subjects underwent breath testing with (13)C-methacetin or (13)C-ketoisocaproate for exploring microsomal and mitochondrial function, respectively. HCC patients repeated the tests 1-2, 30, and 180 d after radiofrequency ablation (n = 27, RFA) or transarterial chemoembolization (n = 10, TACE). RESULTS At baseline, cirrhotic patients showed decreased methacetin demethylation capacity compared with controls (8.1 +/- 2.1 versus 13.7 +/- 1.3% cum. dose exhaled at 60 min, M +/- CI, P < 0.001) and minor changes in ketoisocaproate decarboxylation. HCC patients had methacetin demethylation comparable to cirrhotic subjects, but a significantly lower ketoisocaproate decarboxylation (8.5 +/- 1.0 versus 11.6 +/- 1.9% cum. dose exhaled at 60 min, P < 0.001). Methacetin metabolism was significantly decreased following TACE (-28%, P < 0.05) but not RFA. Ketoisocaproate decarboxylation was unaffected by TACE but decreased after RFA (-27%, P < 0.05). A recovery was noticed with ketoisocaproate as a probe after 1 and 6 mo (P < 0.003). HCC recurrence was associated with early decrease of ketoisocaproate decarboxylation. CONCLUSIONS Liver mitochondrial function is decreased in cirrhotic patients with HCC suggesting a possible tumor-induced suppressant effect. RFA but not TACE appears to spare residual (microsomal) liver mass, but induces such a transient stunning effect on mitochondrial function. Improved mitochondrial function after 1 and 6 mo from RFA may represent an additional parameter of treatment efficacy. Breath test assessing liver function may have potential applications in HCC management.

Recurrent laryngeal nerve palsy and substernal goiter. An Italian multicenter study

The aim of this retrospective multicenter study was to verify whether the substernal goiter and the type of surgical access could be risk factors for recurrent laryngeal nerve palsy during total thyroidectomy. Between 1999-2008, 14,993 patients underwent total thyroidectomy. Patients were divided into three groups: group A (control; n=14.200, 94.7%), cervical goiters treated through collar incision; group B (n=743, 5.0%) substernal goiters treated by cervical approach; group C (n=50, 0.3%) in which a manubriotomy was performed. Transient and permanent unilateral palsy occurred significantly more frequently in B+C vs. A (P≤.001) and in B vs. A (P≤.001). Transient bilateral palsy was significantly more frequent in B+C vs. A (P≤.043) and in C vs. A (P≤.016). Permanent bilateral palsy was significantly more frequent in B+C vs. A (P≤.041), and in B vs. A (P≤.037). Extension of the goiter into the mediastinum was associated to increased risk of recurrent nerve palsy during total thyroidectomy.

Review article: in vitro studies of gall-bladder smooth muscle function. Relevance in cholesterol gallstone disease

The interplay between contraction and relaxation in the gall‐bladder muscularis leads to appropriate gall‐bladder emptying and refilling during fasting and in the postprandial state in vivo. Several studies in both human and animal models have focused on cellular and molecular events in the gall‐bladder wall in health and disease in vitro. Principal methods to study gall‐bladder smooth muscle function include receptor binding studies (at the level of plasmamembranes or histological sections), phase contrast microscopy (at the level of isolated smooth muscle cells), and tensiometry (at the level of smooth muscle strips or the whole gall‐bladder). At a very early stage, cholesterol gallstone disease is characterized by exposure of the gall‐bladder wall to excess of biliary cholesterol and the cytotoxic effect of the bile salt deoxycholate. On a long‐term basis, a form of gall‐bladder leiomyopathy develops with defects involving the mechanisms of signal transduction at the level of plasmamembranes. The end‐stage result is pathological contraction and/or relaxation of smooth musculature, impaired gall‐bladder motility and gall‐bladder stasis, all key factors in the pathogenesis of biliary cholesterol crystallization and gallstones.

Metabolic Syndrome: Differences between Psychiatric and Internal Medicine Patients

Objectives: The existence of specific features of Metabolic Syndrome (MetS) in psychiatric population in comparison to not psychiatric patients has not been systematically investigated. The purpose of this study is to evaluate the differences of MetS among a group of psychiatric patients and a group of internal medicine patients in terms of anthropometric measurements, biochemical variables, and cardiovascular risk. Methods: We enrolled 83 psychiatric inpatients under pharmacological treatment (schizophrenia n = 24, bipolar disorder n = 27, major depression n = 14, other n = 18) and 77 internal medicine patients visited for supposed MetS as affected by overweight or arterial hypertension. Results: Psychiatric patients differed from control subjects by age (yrs) (47 ± 9 vs. 52 ± 8.6, p = 0.001), waist circumference (cm) (111.9 ± 10.9 vs. 106 ± 12.6,p= 0.02), HDL cholesterol (mg/dl) (36.8 ± 7 vs. 48 ± 11.3, p = 0.001), serum insulin (µU/ml) (26 ± 12.5 vs. 16.4 ± 8.8, p = 0.001), triglyceride/HDL cholesterol ratio (4.8 ± 2.7 vs. 3.3 ± 2.2, p = 0.01). Female psychiatric patients had higher levels of triglycerides (mg) (178 + 86 vs. 115 + 53, p = 0.002) and of HOMA index (7.8 + 5 vs. 3.8 + 3.3, p = 0.005). Triglycerides and triglycerides/HDL ratio levels were higher in Unipolar Depression. A positive association was found between antidepressant drug treatment with triglycerides and triglycerides/HDL ratio levels, neuroleptic treatment with the HOMA index, and antipsychotics drugs with the Framingham index. Limitations: Psychiatric study population numerosity and duration of psychiatric illness and drug treatment. Conclusions: Specific features of MetS in psychiatric population are mainly represented by young age of onset, hyperinsulinemia, increased abdominal adiposity, and low HDL cholesterol whose common denominator may be insulin-resistance.

Long-term ursodeoxycholate improves circulating redox changes in primary biliary cirrhotic patients

BACKGROUND AND AIMS Cholestasis is associated with systemic and hepatic oxidative and nitrosative stress; in this scenario, the conjugated hydrophilic bile salt ursodeoxycholate (UDCA) might play a protective role. METHODS Circulating oxidative and nitrosative stress markers were assessed in patients with primary biliary cirrhosis (PBC) before and during UDCA (15-20mg/kg/day) therapy. RESULTS In patients with stage I-II PBC, UDCA improved ALT and alkaline phosphatase levels and near normalized serum thioredoxin (1.97 ± 0.37 vs 2.41 ± 0.39 nmol/L), nitrotyrosine (15 ± 4 vs 22 ± 7 nmol/L), nitrosothiols (144 ± 28 vs 205 ± 84 nmol/L) and K-18 levels (162 ± 21 vs 228 ± 33 U/L). Conversely, less marked changes were noted in patients with stages III-IV who showed lower thioredoxin (1.01 ± 0.31 nmol/L), higher nitrosothiols (605 ± 64 nmol/L), nitrotyrosine (62 ± 13 nmol/L) and K-18 levels (521 ± 57 U/L). Overall, thioredoxin was inversely related with nitrotyrosine (r=-0.838, P<0.001) and K-18 (r=-0.838, P<0.001) levels. Nitrosothiols and K-18 were linearly and significantly related with nitrotyrosine (r=0.862, P<0.001; r=0.894, P<0.001, respectively). CONCLUSIONS Oxidative and nitrosative changes in patients with PBC are effectively counteracted by UDCA. The protective effect of UDCA, however, are limited to early disease stages and progressively diminishes with ongoing cholestasis.

Contractility in vitro and mitochondrial response in small and large rabbit bowel after anastomosis.

Leakage of a large bowel anastomosis remains the most serious postoperative complication in gastrointestinal surgery. In a recent experimental study we found that surgically induced hypoxia resulted in more derangement of a variety of biochemical markers in the large bowel (LB) than in the small bowel (SB). We explored the question of whether spontaneous and agonist-induced contractility of SB and LB muscle strips was influenced by surgical procedures and how contractility was related to energetic oxidative metabolism capacity in smooth muscle mitochondria. Sixty male New Zealand rabbits were operated on under general anesthesia. Segments of ileum and colon were resected from each rabbit, and an end-to-end anastomosis was constructed. A representative subset of segments from SB (n = 14) and LB (n = 14) at time 0 was used as controls. Tracts containing an anastomosis were resected at days 2, 7, and 14 after operation. At each time point, 20 segments adjacent to the anastomosis of both SB and LB were used for tensiometric and biochemical studies. Tensiometric studies demonstrated modifications in the smooth muscle function at both the acute and chronic stages with intestinal inflammation that may contribute to surgical stress-associated abnormal motility. Biochemical data showed that the respiratory capacity of the resected LB was more impaired than that of the SB. In both SB and LB, changes in respiratory activity preceded tensiometric changes. Thus abnormalities of contractility after surgical stress are more evident in LB than SB in segments adjacent to the anastomoses. This could be the consequence of abnormal biochemical changes, as adenosine triphosphate (ATP) is required for membrane potential maintenance, calcium homeostasis, and actin–myosin interactions.

The “Hemolysis Model” for the Study of Cyto-Toxicity and Cyto-Protection by Bile Salts and Phospholipids

The hemolysis of human erythrocytes can be proposed as a valuable in vitro model to study the interaction of different molecules with the plasma membrane: given its simplicity and versatility, this method provides a reliable tool to screen potentially damaging or protective compounds like drugs, nutrients and endogenous molecules, with relevance to the pathophysiology and treatment of human diseases.