Impact of diet in shaping gut microbiota revealed by a comparative study in children from Europe and rural Africa

Gut microbial composition depends on different dietary habits just as health depends on microbial metabolism, but the association of microbiota with different diets in human populations has not yet been shown. In this work, we compared the fecal microbiota of European children (EU) and that of children from a rural African village of Burkina Faso (BF), where the diet, high in fiber content, is similar to that of early human settlements at the time of the birth of agriculture. By using high-throughput 16S rDNA sequencing and biochemical analyses, we found significant differences in gut microbiota between the two groups. BF children showed a significant enrichment in Bacteroidetes and depletion in Firmicutes (P < 0.001), with a unique abundance of bacteria from the genus Prevotella and Xylanibacter, known to contain a set of bacterial genes for cellulose and xylan hydrolysis, completely lacking in the EU children. In addition, we found significantly more short-chain fatty acids (P < 0.001) in BF than in EU children. Also, Enterobacteriaceae (Shigella and Escherichia) were significantly underrepresented in BF than in EU children (P < 0.05). We hypothesize that gut microbiota coevolved with the polysaccharide-rich diet of BF individuals, allowing them to maximize energy intake from fibers while also protecting them from inflammations and noninfectious colonic diseases. This study investigates and compares human intestinal microbiota from children characterized by a modern western diet and a rural diet, indicating the importance of preserving this treasure of microbial diversity from ancient rural communities worldwide.     

General lessons from large‐scale studies to identify human cancer predisposition genes. J Pathol 2010; 220: 255–262

The original article to which this Erratum refers was published in The Journal of Pathology 2010; 220: 255‐262     

Detection of alpha- and beta-human papillomavirus (HPV) in cutaneous melanoma: a matched and controlled study using specific multiplex PCR combined with DNA microarray primer extension

Abstract:  There are few contradictory studies investigating the involvement of HPV in melanoma. We designed a controlled study to evaluate the HPV DNA prevalence in melanoma. One hundred patients with cutaneous malignant melanoma diagnosed between 2002 and 2006 were included. Complementary wide excision (healthy skin) was performed in 85 patients and was used as internal control. After DNA extraction, 68 different HPV types were studied using a multiplex PCR combined with microarray primer extension. We did not observe any statistical significant difference in terms of HPV DNA prevalence in melanoma (38.8%) and in healthy skin from wide excision (42.4%). Twenty-one different HPV types were detected but only one type was present in the majority of our samples (80/85 melanoma vs 59/66 HS). The distribution of HPV genera and types was similar in melanoma and HS, and beta-HPV was predominant (30.6% and 31.8%). Among alpha-HPV (10.6%), high-risk mucosal HPV16 was predominant. Among beta-HPV, melanoma harboured significantly more type 22 than control normal skin from the same patients and significantly less type 21 than paired control normal skin. No correlation between clinical and pathological melanoma characteristics and HPV DNA prevalence was found. Our data do not support a role of HPV infection in melanocarcinogenesis, but confirm the previous data suggesting that HPV DNA is widely distributed among the population and that occult HPV infections are frequent. Furthermore, specific HPV types, such as a-HPV16 and beta-HPV species 2 may be involved in a sub-group of melanoma.     

Cholesterol crystallization in human atherosclerosis is triggered in smooth muscle cells during the transition from fatty streak to fibroatheroma

Recent studies have shown that in addition to being major constituents of the atheromatous core, solid cholesterol crystals (CCs) promote atherosclerotic lesion development and rupture by causing mechanical damage and exerting cytotoxic and pro‐inflammatory effects. These findings suggest that targeting CCs might represent a therapeutic strategy for plaque stabilization. However, little is known about how cholesterol crystallization is initiated in human atherothrombotic disease. Here, we investigated these mechanisms. We performed a thorough immunohistological analysis of non‐embedded, minimally processed human aortic tissues, combining polarized light and fluorescence microscopy. We found that CC formation was initiated during the fatty streak to fibroatheroma transition in tight association with the death of intralesional smooth muscle cells (SMCs). Cholesterol‐loaded human SMCs were capable of producing CCs in vitro, a process that was enhanced by type I collagen and by inhibition of autophagy and cholesterol esterification. The fibrous transition, which was characterized by increased type I collagen expression, was associated with changes in the expression of autophagy and cholesterol flux‐related genes, including a decrease in the autophagic adapter p62 and an increase in the cholesterol intracellular transporter Niemann–Pick C1. Collagen was identified as a potent inducer of these changes in SMCs. Collagen‐induced changes in cholesterol metabolism and autophagy flux in smooth muscle foam cells at the fibrolipid transition likely contribute to initiate cholesterol crystallization in human atherosclerosis. Also, our data are in support of a protective role of autophagy against CC formation. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

In Antisynthetase Syndrome,ACPA Are Associated With Severe and Erosive Arthritis: An Overlapping Rheumatoid Arthritis and Antisynthetase Syndrome

Anticitrullinated peptide/protein antibodies (ACPA), which are highly specific for rheumatoid arthritis (RA), may be found in some patients with other systemic autoimmune diseases. The clinical significance of ACPA in patients with antisynthetase syndrome (ASS), a systemic disease characterized by the association of myositis, interstitial lung disease, polyarthralgia, and/or polyarthritis, has not yet been evaluated with regard to phenotype, prognosis, and response to treatment. ACPA-positive ASS patients were first identified among a French multicenter registry of patients with ASS. Additionally, all French rheumatology and internal medicine practitioners registered on the Club Rhumatismes et Inflammation web site were asked to report their observations of ASS patients with ACPA. The 17 collected patients were retrospectively studied using a standardized questionnaire and compared with 34 unselected ACPA-negative ASS patients in a case–control study. All ACPA-positive ASS patients suffered from arthritis versus 41% in the control group (P < 0.0001). The number of swollen joints was significantly higher (7.0 ± 5.0 vs 2.9 ± 3.9, P < 0.005), with a distribution resembling that of RA. Radiographic damages were also more frequent in ACPA-positive ASS patients (87% vs 11%, P < 0.0001). Aside from a significantly higher transfer factor for carbon monoxide in ACPA–ASS patients, lung, muscle, and skin involvements had similar incidences, patterns, and severity in both groups. Although Nonbiologic treatments were similarly used in both groups, ACPA-positive patients received biologics more frequently (59% vs 12%, P < 0.0008), mostly due to refractory arthritis (n = 9). Eight patients received anti-Cluster of differentiation 20 (CD20) monoclonal antibodies (mAbs) with good efficacy and tolerance, whereas 2 of the 5 patients treated with antitumor necrosis factor drugs had worsened myositis and/or interstitial lung disease. After a >7-year mean follow-up, extra-articular outcomes and survival were not different. ACPA-positive ASS patients showed an overlapping RA–ASS syndrome, were at high risk of refractory erosive arthritis, and might experience ASS flare when treated with antitumor necrosis factor drugs. In contrast, other biologics such as anti-CD20 mAb were effective in this context, without worsening systemic involvements.     

Comparison of oncological outcomes after segmental ureterectomy or radical nephroureterectomy in urothelial carcinomas of the upper urinary tract: results from a large French multicentre study

Study Type – Therapy (multi‐centre retrospective cohort) Level of Evidence 2b What's known on the subject? and What does the study add? Upper urinary tract urothelial carcinomas (UUT‐UCs) are rare tumours. Because of the aggressive pattern of UC, radical nephroureterectomy (RNU) with bladder cuff removal remains the ‘gold‐standard’ treatment. However, conservative strategies, such as segmental ureterectomy (SU) or endourological management, have also been developed in patients with imperative indications. Some teams are now advocating the use of conservative management more commonly in cases of elective indications of UUT‐UCs. Due to the paucity of cases of UUT‐UC, only limited data are available on the oncological outcomes afforded by conservative management. We retrospectively investigated the oncological outcomes after SU and RNU in a large multi‐institutional database. Overall, 52 patients were treated with SU and 416 with RNU. There was no statistical difference between the RNU and SU groups for the 5‐year probability of cancer‐specific survival, recurrence‐free survival and metastasis‐free survival. The type of surgery was not a significant prognostic factor in univariate analysis. The results were the same in a subgroup analysis of only unifocal tumours of the distal ureter with a diameter of <2 cm and of low stage (≤T2). Our results suggest that oncological outcomes after conservative treatment with SU are comparable to RNU for the management of UUT‐UC in select cases.

OBJECTIVE

• ? To compare recurrence‐free survival (RFS), metastasis‐free survival (MFS) and cancer‐specific survival (CSS) after segmental ureterectomy (SU) vs radical nephroureterectomy (RNU) for urothelial carcinoma (UC) of the upper urinary tract (UUT‐UC) located in the ureter.

PATIENTS AND METHODS

• ? We performed a multi‐institutional retrospective review of patients with UUT‐UC who had undergone RNU or SU between 1995 and 2010.
• ? Type of surgery, Tumour‐Node‐Metastasis status, tumour grade, lymphovascular invasion and positive surgical margin were tested as prognostic factors for survival.

RESULTS

• ? In all, 52 patients were treated with SU and 416 with RNU. The median (range) follow‐up was 26 (10–48) months.
• ? The 5‐year probability of CSS, RFS and MFS for SU and RNU were 87.9% and 86.3%, respectively (P= 0.99); 37% and 47.9%, respectively (P= 0.48); 81.9% and 85.4%, respectively (P= 0.51).
• ? In univariable analysis, type of surgery (SU vs RNU) failed to affect CSS, RFS and MFS (P= 0.94, 0.42 and 0.53, respectively).
• ? In multivariable analyses, pT stage and pN stage achieved independent predictor status for CSS (P= 0.005 and 0.007, respectively); the positive surgical margin and pT stage were independent prognostic factors of RFS and MFS (P= 0.001, 0.04, 0.009 and 0.001, respectively).
• ? The main limitation of the study is its retrospective design, which is due to the rarity of the disease.

CONCLUSIONS

• ? Short‐term oncological outcomes after conservative treatment with SU are comparable to RNU for the management of UUT‐UC in select cases and should be considered an option.
• ? In every other case, RNU still represents the ‘gold standard’ for the treatment of UUT‐UC.