Alexandre Vontobel Padoin

The Role of Ultrasound in the Diagnosis of Hepatic Steatosis in Morbidly Obese Patients

Background: Hepatic steatosis is prevalent in obese patients. Although it requires histology for diagnosis, ultrasound may indicate its presence. We evaluated the importance of ultrasound in the diagnosis of steatosis in morbidly obese patients, and considered its clinical relevance for patients with BMI of 35-40 kg/m2 without co-morbidities. Methods: 187 morbidly obese patients submitted to bariatric surgery were prospectively studied. All patients had ultrasound before the operation, and hepatic biopsies during the operation, which were compared. Results: The prevalence of steatosis histologically was 91.4%. The sensitivity and specificity of ultrasound in diagnosing steatosis was 49.1% and 75%, respectively,with a positive predictive value of 95.4%. Conclusion: The biopsies found a very high prevalence of steatosis in the studied population. The ultrasound results yielded a high positive predictive value (95.4%), suggesting its use as a diagnostic tool for this co-morbidity in morbidly obese patients.The low sensitivity of the method could be related to the lack of objective criteria for the ultrasound diagnosis of steatosis, and probably, technical problems in performing ultrasound in such patients. We believe that in patients with a BMI of 35-40 kg/m2 without other comorbidities, the ultrasound finding of steatosis could be of value as an indication for bariatric surgery.

Sources of processed lipoaspirate cells: influence of donor site on cell concentration.

Background: Recently, adipose tissue harvested by liposuction has been identified as a source of processed lipoaspirate cells. The aim of this study was to determine the concentration of processed lipoaspirate cells in adipose tissue obtained by liposuction from different harvest areas in women. Methods: A prospective cross-sectional study was conducted in 25 women in whom liposuction in four or more different zones in the same procedure was indicated. After selective liposuction, the material was sent to the laboratory, where it was processed for extraction of processed lipoaspirate cells, which were separated from the adipose tissue, quantified, and characterized through determination of c-kit expression. The following harvest regions were evaluated: upper abdomen, lower abdomen, trochanteric region, inner thigh, knee, and flank. The cell concentration obtained at each site was compared by analysis of variance for mixed models. Results: A significant difference was found for cell concentration obtained at the different harvest sites. The cell concentration in the lower abdomen was greater than in other areas, but no significant difference was found in relation to the inner thigh. Conclusions: The lower abdomen and the inner thigh may have higher processed lipoaspirate cell concentrations. These sites may turn out to be better sources of adult mesenchymal stem cells.

Effect of Bariatric Surgery on Liver Fibrosis

BackgroundAlthough bariatric surgery has been shown to improve hepatic steatosis in morbidly obese patients, the effect of weight loss on hepatic fibrosis has not been determined. Since the prognosis of patients with nonalcoholic fatty liver disease is closely related to the development of hepatic fibrosis, it is important to determine the hepatic histology of these patients after weight loss. We therefore evaluated the prevalence of hepatic fibrosis in morbidly obese patients undergoing bariatric surgery and assessed the correlation of histologic changes with weight loss.MethodsWe retrospectively evaluated 78 morbidly obese patients who underwent gastric bypass. Liver biopsies were taken during surgery and after weight loss, and the correlations between histologic findings and hepatic fibrosis were determined.ResultsOf the 78 patients, 35 (44.8%) had fibrosis at first biopsy, and 24 (30.8%) had hepatic fibrosis after weight loss, including 19 of the 35 patients (54.3%) with fibrosis at first biopsy and 5 of the 43 (11.6%) without hepatic fibrosis at first biopsy (P = 0.027).ConclusionsWeight loss in morbidly obese patients was associated with a reduction in the prevalence of hepatic fibrosis.

SIRT1 Transcription Is Decreased in Visceral Adipose Tissue of Morbidly Obese Patients with Severe Hepatic Steatosis

BackgroundVisceral adipose tissue is known to release greater amounts of adipokines and free fatty acids into the portal vein, being one of the most predictive factors of nonalcoholic fatty liver disease (NAFLD). Our study has the purpose to evaluate sirtuin 1 (SIRT1), adiponectin, Forkhead/winged helix (FOXO1), peroxisome proliferator-activated receptor (PPAR)γ1–3, and PPARβ/δ mRNA expression in morbidly obese patients in three different lipid depots: visceral (VAT), subcutaneous (SAT), and retroperitoneal (RAT). Recent studies suggest that SIRT1, a NAD+-dependent deacetylase, protects rats from NAFLD.MethodsWe divided the patients in two groups: those with slight or moderate steatosis (hepatic steatosis, HS) and other comprising individuals with severe steatosis associated or not with necroinflammation and fibrosis (severe hepatic steatosis, SHS). The adipose tissue depots were obtained during bariatric surgery. Total RNAs were extracted using TRIzol. The amount of genes of interest was determined by quantitative real-time polymerase chain reaction.ResultsWhen comparing the two groups of patients, a decrease in SIRT1 was observed in VAT of morbidly obese patients in SHS group (p = 0.006). The mRNA expression of the other genes showed no differences in VAT. No difference was found either in SAT or in RAT for all genes in the study. In addition, the homeostasis model assessment for insulin resistance (HOMA-IR) value was higher in SHS group compared to HS (p = 0.006). Also, our results show that the mRNA expression of SIRT1 and the value of HOMA-IR were positively correlated in VAT of SHS patients (r = 0.654; p = 0.048).ConclusionsDownregulation of SIRT1 mRNA expression in VAT of SHS could be possible impairing mitochondria biogenesis and fatty acid oxidation, promoting severe steatosis in obese patients. Our results provide a possible proof of SIRT1 protective potential in VAT against NAFLD in humans.

Resveratrol Upregulated SIRT1, FOXO1, and Adiponectin and Downregulated PPARγ1–3 mRNA Expression in Human Visceral Adipocytes

BackgroundThe SIRT1 enzyme is involved in adipose tissue (AT) lipolysis. FOXO1 is a protein that plays a significant role in regulating metabolism. Adiponectin is an adipokine, secreted by the AT, which has been considered to have an antiobesity function. PPARγ is one of the key actors in adipocytes differentiation. This study was undertaken to investigate whether resveratrol can regulate SIRT1, FOXO1, adiponectin, PPARγ1–3, and PPARβ/δ in human AT.MethodsThe effects of resveratrol were analyzed in freshly isolated adipocytes prepared from visceral fat tissue samples obtained during bariatric surgery. Genes messenger ribonucleic acid (mRNA) levels were determined by qRT-PCR.ResultsOurs results show that resveratrol modulates the studied genes, increasing SIRT1 (p = 0.021), FOXO1 (p = 0.001), and adiponectin (p = 0.025) mRNA expression and decreasing PPARγ1–3 (p = 0.003) mRNA in human visceral adipocytes.ConclusionsResveratrol, in vitro and at low concentration, modulates genes that are related to lipid metabolism, possibly preventing metabolic disease in human visceral adipose tissue (VAT).

A Comparison of the Use of Distal Radius Vascularised Bone Graft and Non-Vascularised Iliac Crest Bone Graft in the Treatment of Non-Union of Scaphoid Fractures

We compared two surgical techniques for the treatment of scaphoid non-union, namely, using distal radius vascularised bone graft and iliac crest non-vascularised bone graft. Eighty patients with symptomatic scaphoid non-union underwent surgical treatment, including 35 patients treated with distal radius vascularised bone graft and 45 treated by iliac crest non-vascularised bone graft. Patients were assessed objectively by examination of wrist range of motion, grip strength and radiographic findings in the postoperative period after a mean time of 2.8 (1.4) (range 1–5.2) years. Similar functional results were obtained with the two techniques. All cases of non-union in the non-vascularised group obtained consolidation in a mean time of 8.89 (2.26) months and in the vascularised group in a mean time of 7.97 (3.06) months. Three cases of consolidation failure occurred in the vascularised group and were related to technical difficulties.

Wrist denervation for painful conditions of the wrist.

PURPOSE To evaluate the long-term (6-y) results of Wilhelms wrist denervation technique used as an isolated procedure for painful conditions of the wrist. METHODS We conducted a retrospective review of 49 wrist denervations that were performed as isolated procedures in patients with painful wrist conditions. Indication for surgery was degenerative osteoarthritis of the wrist caused by scaphoid nonunion advanced collapse in 19 patients, Kienböcks disease in 13 patients, and primary degenerative osteoarthritis in 17 patients. RESULTS The results were analyzed as a group and by comparing the 3 etiologies. Average pain improvement after surgery for all groups was 68% ± 8% after the first month and reached a plateau at the end of the first year, with the percentage remaining stable at 36 months at 79% ± 4%. Grip strength on the treated side improved from 43% of the opposite side before denervation to 69% of the opposite side. The range of motion showed improvements in all axes of movement, without statistical differences between groups. Radiological evaluation after 72 months revealed worsening in 34 patients. There was no difference in results between the 3 groups with regard to grip strength, range of motion, or pain relief obtained. CONCLUSIONS Wrist denervation resulted in improvement in pain scores in 39 patients despite radiological deterioration noted in 34 after 6 years. TYPE OF STUDY/LEVEL OF EVIDENCE Therapeutic IV.

Obesity depresses the anti‐inflammatory HSP70 pathway, contributing to NAFLD progression

To evaluate whether reduced activity of the anti‐inflammatory HSP70 pathway correlates with nonalcoholic fatty liver disease (NAFLD) progression and with markers of oxidative stress because obesity activates inflammatory JNKs, whereas HSP70 exerts the opposite effect.

Weight‐loss interventions and gut microbiota changes in overweight and obese patients: a systematic review

Imbalances in the gut microbiota, the bacteria that inhabit the intestines, are central to the pathogenesis of obesity. This systematic review assesses the association between the gut microbiota and weight loss in overweight/obese adults and its potential manipulation as a target for treating obesity. This review identified 43 studies using the keywords ‘overweight’ or ‘obesity’ and ‘microbiota’ and related terms; among these studies, 17 used dietary interventions, 11 used bariatric surgery and 15 used microbiota manipulation. The studies differed in their methodologies as well as their intervention lengths. Restrictive diets decreased the microbiota abundance, correlated with nutrient deficiency rather than weight loss and generally reduced the butyrate producers Firmicutes, Lactobacillus sp. and Bifidobacterium sp. The impact of surgical intervention depended on the given technique and showed a similar effect on butyrate producers, in addition to increasing the presence of the Proteobacteria phylum, which is related to changes in the intestinal absorptive surface, pH and digestion time. Probiotics differed in strain and duration with diverse effects on the microbiota, and they tended to reduce body fat. Prebiotics had a bifidogenic effect and increased butyrate producers, likely due to cross‐feeding interactions, contributing to the gut barrier and improving metabolic outcomes. All of the interventions under consideration had impacts on the gut microbiota, although they did not always correlate with weight loss. These results show that restrictive diets and bariatric surgery reduce microbial abundance and promote changes in microbial composition that could have long‐term detrimental effects on the colon. In contrast, prebiotics might restore a healthy microbiome and reduce body fat.

Can Local Supply of Bone Marrow Mononuclear Cells Improve the Outcome from Late Tubular Repair of Human Median and Ulnar Nerves

The purpose of this non-randomised retrospective study was to compare nerve regeneration after reconnection with silicone tubes with two different strategies. A total of 44 patients with injured median or ulnar nerves in the forearm were surgically treated. In one group of patients, a silicone tube alone was placed in the nerve gap. In a second group, the silicone tube was filled with autologous bone marrow mononuclear cells obtained by aspiration from the iliac crest. Motor function, sensation and the effect of pain on function were assessed 1 year after surgery. The tubes filled with bone marrow cells showed better recovery than the empty tubes. The use of bone marrow mononuclear cells in addition to tube re-connection may promote better nerve regeneration than conventional tubular repair.