Evaluation of the pathologic response to neoadjuvant treatment in rectal cancer. Experience at the Instituto de Cancerología de Medellín (Colombia, 2011-2017). / Evaluación de la respuesta patológica al tratamiento neoadyuvante en cáncer de recto. Experiencia del Instituto de Cancerología de Medellín (Colombia, 2011-2017).

INTRODUCTION AND AIMS: Neoadjuvant therapy in rectal cancer is associated with a decrease in tumor size and is the therapeutic indication for patients with T3 or T4 tumors or lymph node involvement. Our aim was to describe the frequency of pathologic response and the survival rate in patients that underwent neoadjuvant therapy for rectal cancer. MATERIALS AND METHODS: A retrospective follow-up study with a survival analysis was conducted. Patients with locally advanced rectal cancer that received neoadjuvant treatment and were operated on at the Instituto de Cancerología Las Américas (Medellín, Colombia) were analyzed. Survival was calculated using the Kaplan-Meier method. RESULTS: A total of 152 patients were included. Mean patient age was 59 years (12.8 SD), 53.9% were men, and 58.6% of the patients were diagnosed with stage IIIB disease. The pathologic complete response (pCR) was achieved in 17% of the patients. A total of 146 (96.1%) patients received the chemoradiotherapy protocol. Fifty-two (34.2%) patients developed metastasis and/or relapse, and one (3.8%) of those patients had presented with pCR. The median follow-up period was 33 months (Q1-Q3: 20-45), with an overall survival rate of 79.5% (95% CI 70.9-85.8). The 5-year survival rate for the patients that had pCR was 80% (95% CI 20.3-96.9). CONCLUSIONS: The frequency of pCR was similar to that in other published studies and disease recurrence was lower, compared with patients with no response. The 5-year survival rate in patients with pCR was high, albeit lower than that reported in other studies.

Poly(L-lactide)/branched ß-cyclodextrin blends: Thermal, morphological and mechanical properties.

In this work we develop poly(L-lactide)/branched ß-cyclodextrin (bßCD) blends in an attempt to obtain new biocompatible and biodegradable materials to be used in the emerging fields of pharmaceutical, biomedicine and food industry. Ionic branched ß-cyclodextrin (bßCD) was obtained by polycondensation of the ß-CD monomer and it was blended with a commercially available PLLA. Fourier transform infrared spectroscopy (FTIR) has been applied to study the occurring interactions between both partners. Thermal properties of blends have been analyzed by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), while the phase structure of the blends was analyzed by scanning electron microscopy (SEM). Finally, dynamic mechanical analysis (DMA) has been used to provide further insights into the features controlling miscibility between PLLA and bßCD. Results show the presence of a single phase irrespectively of the blend composition. Overall, this work opens new perspectives for the development of naturally available materials with tunable functional properties for applications in which cyclodextrins emerge as a new class of promising candidates.

Increased functional properties and thermal stability of flexible cellulose nanocrystal/ZnO films.

In this work we attempt to improve the functional properties and thermal stability of cellulose nanocrystal (CNC) films by means of eco-friendly materials and processes. Mechanically flexible films of closely packed CNCs with concentrations up to 5 wt.% of zinc oxide (ZnO) nanoparticles have been prepared by a simple, standard and environmentally friendly method using solely water. Results reveal that ultraviolet light is blocked by 98.5% at 1 wt.% ZnO while good transparency is maintained. A sharp hydrophobicity increase is observed with the addition of ZnO which would enhance the durability of films by decreasing the water diffusion through the material. The thermal degradation activation energy (E) presents an increase of 141%, denoting a high thermal stability of films, which would result beneficial for their potential application in the field of flexible electronics. Mechanical results demonstrate a high structural integrity of CNC/ZnO as a result of the occurring strong cellulosic inter- and intramolecular interactions within the closely packed CNC network. In overall, this work highlights the potential for environmentally friendly processing of sustainable nanostructured functional materials based on cellulose.

Crystallization, structural relaxation and thermal degradation in Poly(L-lactide)/cellulose nanocrystal renewable nanocomposites.

In this work, crystallization, structural relaxation and thermal degradation kinetics of neat Poly(L-lactide) (PLLA) and its nanocomposites with cellulose nanocrystals (CNC) and CNC-grafted-PLLA (CNC-g-PLLA) have been studied. Although crystallinity degree of nanocomposites remains similar to that of neat homopolymer, results reveal an increase on the crystallization rate by 1.7-5 times boosted by CNC, which act as nucleating agents during the crystallization process. In addition, structural relaxation kinetics of PLLA chains has been drastically reduced by 53% and 27% with the addition of neat and grafted CNC, respectively. The thermal degradation activation energy (E) has been determined from thermogravimetric analysis in the light of Kissinger's and Ozawa-Flynn-Wall theoretical models. Results reveal a reduction on the thermal stability when in presence of CNC-g-PLLA, while raw CNC slightly increases the thermal stability of PLLA. Fourier transform infrared spectroscopy and energy dispersive X-ray spectroscopy results confirm that the presence of residual catalyst in CNC-g-PLLA plays a pivotal role in the thermal degradation behavior of nanocomposites.

Reutilization of thermostable polyester wastes by means of agglomeration with phenolic resins.

We report on the possibility of obtaining organic polymeric matrixes allowing the development of new high performance fire-resistant products by recycling downsized thermostable waste materials. Phenolic resins have been used as binders for recycled waste. Furthermore, considering that reinforced plastic triturations have superior properties (chemical, mechanical, water resistance, etc.) to wood agglomerates, significant advantages over conventional materials are anticipated. In summary, we propose a viable solution to some of the known problems caused by the consumption of wood and to the needs of strengthened plastic processing engineering. Using resins as a binder, several fire-resistant prototypes were prepared from polyester waste, and their mechanical properties, thermal stability, and fire-resistant properties were analyzed.

A multicentric comparison of transabdominal versus totally extraperitoneal laparoscopic hernia repair using PARIETEX meshes.

The authors report a series of 1972 inguinal hernias treated between 1993 and 1997 by the insertion of a PARIETEX mesh via either a transabdominal-preperitoneal (TAPP) (1,290 procedures) or a totally extraperitoneal TEP approach (682 procedures). Pain scores were equivalent in both groups, while the hospital stay and time to return to normal activity was lower in the TEP group than in the TAPP group (p<0.001). In both groups, the average incidence of the total reported events (complications) was around 10% with no statistical difference. This ratio seemed to compare favorably to previously published reports. Chronic pain was extremely rare (0.6% and 0.7% in the TAPP and TEP groups, respectively). Whatever the approach was, sepsis was also very rare (1/1,526 laparoscopic procedures). These findings illustrate the local tolerance of the mesh. Recurrence rates were below 1% with no statistical difference between groups. This retrospective study demonstrates the clinically apparent local tolerance of this type of mesh. Prospective and long-term clinical results will be necessary to demonstrate that the optimized short-term tolerance of PARIETEX mesh will influence the long term functional results.

Hepatic artery aneurysm rupture: case report, imaging findings, and literature review.

Hepatic artery aneurysm rupture is a rare condition that requires urgent diagnosis and treatment in order to avoid a potentially fatal outcome. The clinical presentation is often non-specific. The classic triad of abdominal pain, gastrointestinal hemorrhage, and obstructive jaundice occurs in less than one-third of cases. Physical examination is rarely helpful since bruits, masses or pulsations are infrequent. Radiologic imaging provides the best tool to early diagnosis. Angiography has historically been the gold standard of diagnosis and is needed prior to radiologic intervention. Computerized tomography, doppler ultrasound and even magnetic resonance imaging have all demonstrated visceral artery aneurysms with success. Conventional treatment has included surgical ligation and resection. More recently transcatheter embolization or even percutaneous transhepatic injection of thrombin has been successfully performed by the interventional radiologist. This article discusses the clinical presentation, imaging findings, and review of the literature of this elusive entity.

Biotin-hydrazide derivatives for the development of steroid enzyme-linked immunoassays.

We are describing the synthesis and use of biotinamidocaproyl-derivatives of 18-oxocortisol-3-carboxymethoxylamine for the development of enzyme labels using the avidin-peroxidase system for the design of enzyme-linked immunoassays (ELISA). An ELISA for 18-oxocortisol and -hydroxycorticosterone was devised which showed improved sensitivity and specificity in comparison to an RIA using a tritiated tracer. The system is easy to prepare and offers the possibility to design immunoassays when no tritiated tracer is available.

Consideracoes sobre a casuistica do ambulatorio de medicina do trabalho da Faculdade de Ciencias Medicas da UNICAMP. / Considerations on cases from the Occupational Medicine Ambulatory of the Faculdade de Ciencias Medicas da UNICAMP

Neste estudo, procede-se a analise da casuistica do ambulatorio de Medicina do Trabalho do Departamento de Medicina Preventiva e Social da Faculdade de Ciencias Medicas da Universidade Estadual de Campinas (UNICAMP), baseada em 629 casos atendidos no periodo de julho de 1978 a setembro de 1981. Destes atendimentos, 257 referem-se especificamente a doencas profissionais tipicas, que, na ordem de frequencia, foram assim distribuidas: surdez profissional (43%), dermatoses do trabalho (26%), pneumopatias ocupacionais (19%) e intoxicacoes profissionais (8,0%). O estudo e complementado pela analise de outras caracteristicas, tais como: fonte de encaminhamento dos pacientes, ramos de atividade exercida, sexo, grupo etario, tempo de exposicao e agentes causais das dermatoses