Long-term results with biosynthetic absorbable P4HB mesh in ventral abdominal wall repair: a multicentre analysis.

BACKGROUND: The aim of this multicentre study was to analyse the outcomes of biosynthetic absorbable poly-4-hydroxybutyrate (P4HB) prosthesis implantation in patients undergoing ventral hernia repair (VHR) in the context of different degrees of contamination. METHODS: From May 2016 to December 2021, a multicentre retrospective analysis of patients who underwent elective or urgent hernia repair with P4HB prosthesis was performed in seven hospitals in Spain and Portugal. Patients with a postoperative follow-up of less than 20 months and those within the theoretical period of prosthesis resorption were excluded from the study. Regarding the degree of contamination, patients were assessed according to the modified Ventral Hernia Working Group (VHWG) classification. Epidemiological data, hernia characteristics, surgical and postoperative variables (Clavien-Dindo classification) of these patients were analyzed. Risk factors related to long-term recurrence were studied by a multivariate analysis. RESULTS: In 236 cases of P4HB prosthesis implantation, repair in cases of Grade 3 was the most frequent (49.1%), followed by Grade 2 in 42.3% of cases and Grade 1 in 8.4%. The most frequent complications were Grade 1, with the majority occurring during the first year. The overall rate of surgical site occurrences (SSO) was 30%. The hernia recurrence rate was 14.4% (n = 34), with a mean postoperative follow-up time of 41 months (22-61). The multivariate analysis showed that the onlay location of the mesh (OR 1.07; CI 1.42-2.70, p = 0.004) was a significant independent risk factor for recurrence. CONCLUSIONS: The use of a P4HB bioresorbable mesh for the VHR with different degrees of contamination leads to favourable results overall, with an acceptable rate of hernia recurrence. The onlay location of the P4HB prosthesis is the main factor in recurrence in both elective and emergency settings.

Biosynthesis of magnetic iron oxide nanoparticles: a review.

Nanoparticles promise to revolutionize the way we think of ordinary materials thanks to the new features such small structures exhibit which include strength, durability, optical and magnetics properties. Magnetic iron oxide nanoparticles (IONPs) are a prominent class of NMs because of their potential application in magnetic separation, hyperthermia, targeted drug delivery, and catalysis. Most synthetic nanoparticulate platforms rely on the use of tough chemical procedures associated with unfriendly, harmful and costly reactants. For this reason, bio-inspired approaches have become the most successful alternatives to fabricate nanomaterials in an "eco-friendly" manner, and many bio-protocols that make use of substrates from plants and microorganisms have been successfully applied in the synthesis of magnetic IONPs. In this review, the main biosynthesis protocols applied in the synthesis of iron oxide nanoparticles are discussed. A discussion on the challenges for a second stage perspective which would be a large scale production is also given.

A genetic cluster of patients with variant xeroderma pigmentosum with two different founder mutations.

BACKGROUND: Xeroderma pigmentosum (XP) is a rare human syndrome associated with hypersensitivity to sunlight and a high frequency of skin tumours at an early age. We identified a community in the state of Goias (central Brazil), a sunny and tropical region, with a high incidence of XP (17 patients among approximately 1000 inhabitants). OBJECTIVES: To identify gene mutations in the affected community and map the distribution of the affected alleles, correlating the mutations with clinical phenotypes. METHODS: Functional analyses of DNA repair capacity and cell-cycle responses after ultraviolet exposure were investigated in cells from local patients with XP, allowing the identification of the mutated gene, which was then sequenced to locate the mutations. A specific assay was designed for mapping the distribution of these mutations in the community. RESULTS: Skin primary fibroblasts showed normal DNA damage removal but abnormal DNA synthesis after ultraviolet irradiation and deficient expression of the Polη protein, which is encoded by POLH. We detected two different POLH mutations: one at the splice donor site of intron 6 (c.764 +1 G>A), and the other in exon 8 (c.907 C>T, p.Arg303X). The mutation at intron 6 is novel, whereas the mutation at exon 8 has been previously described in Europe. Thus, these mutations were likely brought to the community long ago, suggesting two founder effects for this rare disease. CONCLUSIONS: This work describes a genetic cluster involving POLH, and, particularly unexpected, with two independent founder mutations, including one that likely originated in Europe.

Efficacy of infliximab rescue therapy in patients with chronic refractory pouchitis: a multicenter study.

BACKGROUND: Despite medical therapy, 30% of patients with ulcerative colitis (UC) need to undergo surgery. Around 50% of patients with proctocolectomy with ileal pouch-anal anastomosis (IPAA) develop complications of the pouch. Clinical evidence for the use of infliximab (IFX) in refractory pouchitis is limited. The aim of this study was to report efficacy of IFX in these patients. METHODS: A retrospective, multicenter study was designed. Patients older than 18 years with chronic refractory pouchitis treated with IFX (5 mg/kg) were included. Short-term IFX efficacy was evaluated at week 8 and mid-term efficacy at weeks 26 and 52. Complete response was defined as cessation of diarrhea and urgency and partial response as marked clinical improvement but persisting symptoms. The modified Pouchitis Disease Activity Index (mPDAI) without endoscopy was calculated when available. RESULTS: Thirty-three consecutive UC patients with chronic refractory pouchitis were included (18 male, mean age 45 years, range 21-67). At week 8, 21% patients achieved complete response and 63% showed partial clinical response. At weeks 26 and 52, 33% and 27% achieved complete response and 33% and 18% showed partial clinical response, respectively. Thirteen patients (39%) withdrew treatment (four for lack of efficacy, four for loss of response and five for adverse events). None of the potential factors analyzed had an influence on response to IFX. CONCLUSIONS: IFX was effective in the short- and mid-term in patients with chronic refractory pouchitis. However, medication had to be discontinued in a high number of patients.

Emigration to western industrialized countries: A risk factor for developing inflammatory bowel disease.

BACKGROUND: A higher incidence of inflammatory bowel disease (IBD) in industrialized areas has been previously reported, but the effect of emigrating to western industrialized countries for a period of time and returning to the country of origin is unknown. Aim of the study was to evaluate the effect of emigrating to another country and returning to the place of origin on the risk of IBD. METHODS: A prospective case-control study was performed. Inclusion criteria were all patients >18 years diagnosed with Crohn's disease (CD) or ulcerative colitis (UC) in the last 10 years. Healthy, unrelated controls, matched by sex, age and smoking habits, with no family history of IBD were included. All patients and controls were interviewed and emigration was defined as living for at least one year in another country. RESULTS: 242 consecutive patients with IBD (105 CD and 137 UC) and 242 controls were included. Patients who had previously emigrated developed more frequently IBD than controls (OR 1.93, 95%CI 1.19-3.15, p<0.01). Patients who emigrated to European countries developed more frequently IBD than controls (OR 1.91, 95%CI 1.07-3.47, p=0.02), but not those who had emigrated to Latin America (OR 1.48, 95%CI 0.67-3.27, p=0.32). Emigration plays a significant role in the development of UC (OR 2.24, 95%CI:1.29-3.88, p<0.01), but not in CD (OR 1.56, 95%IC:0.83-2.92, p=0.15). CONCLUSIONS: People who emigrate to westernised countries have a higher risk for developing IBD, especially UC. Environmental factors related with industrialization seem to play an important role in the pathogenesis of these diseases.

Intercorrência entre leucose enzoótica e tuberculose em bovinos leiteiros do estado de Pernambuco / Assessment of intercurrence of enzootic leucosis and bovine tuberculosis in dairy cows in the state of Pernambuco, Brazil

Objetivou-se com este estudo avaliar a intercorrência entre leucose enzoótica e tuberculose em rebanhos bovinos leiteiros em oito municípios do Estado de Pernambuco, pelo estabelecimento da prevalência de bovinos reagentes às provas diagnósticas específicas. Foram analisados sorologicamente 662 animais, pela técnica de imunodifusão dupla em gel de agarose e 612 foram avaliados imunoalergicamente, por meio do teste de tuberculinização. Nos 15 rebanhos examinados, as prevalências de bovinos que apresentaram positividade aos testes IDGA e tuberculina foram 32,2% (213/662) e 14,1% (86/612), respectivamente. Os resultados obtidos nesta pesquisa permitiram concluir que as doenças estudadas encontram-se amplamente disseminadas na população avaliada, com crescimento em níveis significativos da leucose, e as infecções pelo vírus da leucose bovina (VLB) e Mycobacterium bovis encontram-se ativas e em expansão, com risco do comprometimento da saúde dos rebanhos bovinos e, pelo caráter zoonótico da tuberculose bovina, das pessoas que lidam com os bovinos.

We carried out this study to evaluate the intercurrence of tuberculosis and enzootic leukosis in dairy cattle herds in 8 districts of the State of Pernambuco, Brazil, by establishing the prevalence of bovines reagent to specific diagnostic tests, and to also verify the correlation between enzootic leucosis, cattle tuberculosis, the leukocytes count and lymphocytes count among the cattle studied. A total of 662 animals were tested serologically and hematologically, by the techniques of double immunodiffusion in agarose gel and the white blood cell count with the total and differential leukocyte count, respectively, and 612 were evaluated immunoallergically by the tuberculin test. In the 15 herds examined, the prevalence of cattle that were positive to the AGID and tuberculin tests were 32.2% (213/662) and 14.1% (86/612), respectively. Analyzing the correlation between the variables total leukocytes and lymphocytes, we found that total leukocyte is highly related to the variable lymphocytes (72%). The results in this study indicated that the diseases studied are widespread in the population studied, with significant levels of growth in leukemia, and infections of bovine leukosis virus (VLB) and Mycobacterium bovis are active and growing, with risk of impairment of the health of cattle herds, and, due to the zoonotic nature of bovine tuberculosis, of the health of people who work with cattle.

Characterization of the herpes simplex virus (HSV)-1 tegument protein VP1-2 during infection with the HSV temperature-sensitive mutant tsB7.

VP1-2, encoded by the UL36 gene of herpes simplex virus (HSV), is a large structural protein, conserved across the family Herpesviridae, that is assembled into the tegument and is essential for virus replication. Current evidence indicates that VP1-2 is a central component in the tegumentation and envelopment processes and that it also possesses important roles in capsid transport and entry. However, any detailed mechanistic understanding of VP1-2 function(s) remains limited. This study characterized the replication of HSV-1 tsB7, a temperature-sensitive mutant restricted at the non-permissive temperature due to a defect in VP1-2 function. A tsB7 virus expressing green fluorescent protein-fused VP16 protein was used to track the accumulation and location of a major tegument protein. After infection at the permissive temperature and shift to the non-permissive temperature, the production of infectious virus ceased. VP1-2 accumulated in altered cytosolic clusters, together with VP16 and other virion proteins. Furthermore, correlating with the results of immunofluorescence, electron microscopy demonstrated abnormal cytosolic capsid clustering and a block in envelopment. As VP1-2 encompasses a ubiquitin-specific protease domain, the occurrence of ubiquitin-conjugated proteins during tsB7 infection was also examined at the non-permissive temperature. A striking overaccumulation was observed of ubiquitin-specific conjugates in cytoplasmic clusters, overlapping and adjacent to the VP1-2 clusters. These results are discussed in relation to the possible functions of VP1-2 in the assembly pathway and the nature of the defect in tsB7.

Microbiological evaluation of acute periradicular abscesses by DNA-DNA hybridization.

OBJECTIVE: The purpose of the present investigation was to examine the microbiota of acute periradicular abscesses of endodontic origin by using a molecular genetic method. STUDY DESIGN: Pus was collected by aspiration from 27 cases diagnosed as acute abscesses of endodontic origin, and DNA was extracted to evaluate the occurrence of 49 bacterial species by using whole genomic DNA probes and checkerboard DNA-DNA hybridization. The presence of bacterial DNA in clinical samples was confirmed by polymerase chain reaction with ubiquitous bacterial 16S rRNA gene primers. RESULTS: The results of the checkerboard DNA-DNA hybridization analysis revealed that 37 of the 49 DNA probes tested were reactive with one or more samples. The number of bacterial species in the pus samples ranged from 1 to 33 (mean, 5.9). Eighteen of the 27 pus samples were positive for at least one DNA probe. The most prevalent species found were: Bacteroides forsythus (29.6% of the cases); Porphyromonas gingivalis (29.6%); Streptococcus constellatus (25.9%), Prevotella intermedia (22.2%), Prevotella nigrescens (22.2%), Fusobacterium periodonticum (18.5%), Fusobacterium nucleatum subspecies nucleatum (18.5%), and Eikenella corrodens (18.5%). CONCLUSIONS: The microbiologic data of the present investigation indicated that molecular genetic methods could provide additional knowledge regarding the microbiota of acute periradicular abscesses by detecting bacterial species that are difficult--or even impossible--to grow.

Checkerboard DNA-DNA hybridization analysis of endodontic infections.

OBJECTIVE: The purpose of this investigation was to examine the microbiota of infected root canals by using a molecular genetic method. STUDY DESIGN: The presence and levels of 42 bacterial species were determined in 28 root canal samples by using whole genomic DNA probes and checkerboard DNA-DNA hybridization. To confirm the presence of bacterial DNA in clinical samples, a polymerase chain reaction with an ubiquitous bacterial primer was undertaken. RESULTS: The results of the checkerboard DNA-DNA hybridization analysis showed that 22 of the 42 DNA probes tested were reactive with 1 or more samples. The number of bacterial species in the root canal samples ranged from 1 to 17 (mean, 4.7). Seventeen of the 28 root canal samples were positive for at least 1 DNA probe. The most prevalent species found were as follows: Bacteroides forsythus (39. 3% of the cases); Haemophilus aphrophilus (25%); Corynebacterium matruchotii (21.4%); Porphyromonas gingivalis (17.9%); and Treponema denticola (17.9%). CONCLUSIONS: The microbiologic data of the present investigation indicated that molecular genetic methods can provide significant additional knowledge regarding the endodontic microbiota by detecting bacterial species that are difficult or impossible to culture. In addition, our findings support the current concept that endodontic infections are mixed infections of polymicrobial etiology.

Eight years experience using the inferior epigastric artery for myocardial revascularization.

We present the initial experience with the use of inferior epigastric artery as a free graft for myocardial revascularization in a series of 41 patients operated on between 1987 and 1989 to show the clinical and angiographic results. Of the 41 patients, 29 were male, 12 female, with ages ranging from 33 to 72 years, and weights from 50 to 86 kg. The inferior epigastric artery grafts were predominantly employed to the anterior interventricular branch and diagonal branch. The proximal anastomosis into the aorta was done directly or with a patch of vein or pericardium. The 32 patients who survived had mean follow-up of 82 months and 22 are in functional class I, 8 in class II and 2 in class III of angina. The early patency rate was: inferior epigastric artery-anterior interventricular branch, 85.7% and inferior epigastric artery-diagonal branch. 85.7%. Sixteen patients underwent angiographic study at a mean follow-up of 81.2 months and the patency rate to the anterior interventricular branch was 77.7% and to the diagonal branch was 100%. Three patients with early occluded inferior epigastric artery were reoperated on 3, 3 and 11 months after the operation. A filiform lumen of the graft and a small ostium in the aorta was found and explained the imperfection of the direct anastomosis due to unbalance thickness of the graft and the aortic wall. Therefore it is occluded that the inferior epigastric artery is an alternative arterial graft for myocardial revascularization and that the use of a vein or pericardium patch can help the proximal anastomosis and improve potency of the graft.

Right internal thoracic artery through the transverse sinus in myocardial revascularization.

BACKGROUND: This study presents the late patency rate of the right internal thoracic artery (ITA) used in situ through the pericardium transverse sinus to the circumflex artery and its branches. METHODS: From April 1983 to December 1994, 2,642 patients were submitted to myocardial revascularization; 201 of them had bilateral ITAs. The right ITA through the transverse sinus was grafted to obtuse marginal artery in 170 patients (84.5%) and the left ITA was grafted to the anterior descending artery in 188 patients (93.5%). Angiographic studies were performed in 80 patients, 44 patients in the immediate postoperative period and 36 patients in the late follow-up (mean, 51.6 months). RESULTS: The right ITA was patent in 75 patients (93.7%) and the left ITA was patent in 77 (96.2%). At the late postoperative period, the right ITA was patent in 33 patients (91.6%) and the left ITA was patent in 34 (94.4%). CONCLUSIONS: The right ITA placed through the pericardium transverse sinus has a good long-term patency rate, similar to that observed with the left ITA and superior to that of saphenous vein grafts for myocardial revascularization.

Molecular approaches to diagnosis of Chagas' disease: use of defined antigens and a target ribosomal RNA sequence.

We evaluated the performance of two defined antigens in the serological diagnosis of Chagas' disease. One of them is a recombinant protein named B13 isolated from a genomic library of Trypanosoma cruzi in the expression vector lambda gtll. We show that the gene corresponding to B13 is conserved in the evolutive stages of the two "polar" strains of T. cruzi. The protein epitopes cloned in B13 are represented in 140 kDa, 116 kDa and 35 kDa polypeptides of trypomastigotes. The other antigen chosen for serodiagnosis is a lipopeptidophosphoglycan (LPPG). This glycoconjugate is also widely distributed in T. cruzi strains. The use of a rabbit serum to LPPG allowed the demonstration that this molecule bears epitopes in common to LPPG-like components and to 80-90 kDa glycoproteins of trypomastigotes. Both B13 and LPPG were evaluated in serodiagnosis by ELISA and RIA using a panel of normal human, Chagasic and Leishmaniasis sera. It was observed that B13 presents high sensitivity and specificity for Chagasic sera. For LPPG it was also concluded that this reagent discriminates between individuals infected and non-infected with T. cruzi. A heterogeneity in the level of antibodies to LPPG in Chagasic patients was detected. No correlation was found between the clinical form of Chagas' disease and the preferential reactivity to B13 or LPPG. We also report preliminary studies towards the characterization of a 100 bp sequence of the 24S alpha rRNA as a target for DNA-based detection systems for diagnosis. We show that polymerase chain reaction of total DNA of different trypanosomatids lead to the specific amplification of a 100 bp fragment only for T. cruzi. Northern blots confirmed the presence of the target region in the mature 24S alpha rRNA. Titration experiments based on the direct amplification of RNA with Taq DNA polymerase allowed the detection of 50 parasites. Studies are in progress to increase the sensitivity of the proposed system.