Phytotoxicity of silver nanoparticles to Lemna minor: Surface coating and exposure period-related effects

Silver nanoparticles (Ag NPs) exponential production raises concern about their environmental impact. The effects of Ag NPs to aquatic plants remain scarcely studied, especially in extended exposures. This paper aims to evaluate Ag NPs effects in Lemna minor at individual and sub-individual levels, focusing on three variables: Ag form (NPs versus ions - Ag⁺), NPs surface coating (citrate vs polyvinylpyrrolidone - PVP) and exposure period (7 vs 14days). Endpoints were assessed at individual level (specific growth rate, chlorosis incidence and number of fronds per colony) and sub-individual level (enzymatic activities of catalase (CAT), guaiacol peroxidase (GPx) and glutathione-S-transferase (GST)). Generally, plants exposed to all Ag forms underwent decays on growth rate and fronds per colony, and increases on chlorosis, GPX and GST, but no effects on CAT. The most sensitive endpoints were specific growth rate and GPx activity, showing significant effects down to 0.05mg/L for Ag NPs and 3μg/L for Ag⁺, after 14days. Ag⁺ showed higher toxicity with a 14d-EC₅₀ of 0.0037mg Ag/L. Concerning surface coating, PVP-Ag NPs were more deleterious on growth rate and fronds per colony, whereas citrate-Ag NPs affected more the chlorosis incidence and GPx and GST activities. The exposure period significantly affected chlorosis: 14days triggered a chlorosis increase in Ag⁺-exposed plants and a decrease in Ag NPs-exposed plants when compared to 7days. Ag NPs induced an oxidative stress status in cells, thus ensuing upregulated enzymatic activity as a self-defense mechanism. Since Ag NPs dissolution might occur on a steady and continuous mode along time, and the average longevity of fronds, we propose longer exposures periods than the recommended by the OECD guideline. This approach would provide more relevant and holistic evidences on the overall response of freshwater plants to Ag NPs in an ecological relevant scenario.

Ipsilateral neck cancer recurrences after elective supraomohyoid neck dissection

DESIGN

Retrospective analysis of a case series.

SETTING

Referral center, private or institutional practice, hospitalized care.

OBJECTIVE

To analyze the level (site) of ipsilateral neck recurrences after supraomohyoid (SOH) dissection in patients with lip, oral, and oropharyngeal cancer treated in a single institution.

INTERVENTION

Supraomohyoid neck dissection.

PATIENTS AND METHODS

From 1979 to 1997, 154 patients with oral and oropharyngeal carcinoma and no palpable lymph nodes at the neck underwent ipsilateral elective SOH dissection.

RESULTS

Tumor sites were the lip, 5 cases (3.3%); oral cavity, 128 cases (83.1%); and oropharynx, 21 cases (13.6%). Tumor stages were T1, 13 cases (8.4%); T2, 77 cases (50.0%); T3, 40 cases (27.0%); and T4, 22 cases (14.3%). There were 7 cases (4.5%) of ipsilateral neck recurrences. Three were beyond the limits of the SOH dissection, and 4 were inside these limits. There was no association of neck recurrences with the pathological status of the lymph nodes. Six of the 7 recurrences were in patients who underwent postoperative radiotherapy.

CONCLUSIONS

The incidence of neck recurrence after selective neck dissection was 4.5%, and it occurred either inside (57.1%) or beyond (42.9%) the limits of the selective neck dissection.

Prognostic and predictive value of the thymidylate synthase expression in patients with non-metastatic colorectal cancer

AIMS

To assess the value of thymidylate synthase (TS) expression as a predictive factor in the efficacy of adjuvant chemotherapy in colorectal cancer, as well as its independent prognostic value for survival.

METHODS

We studied 114 high risk colorectal carcinoma patients (high risk stage II and stage III), distributed in two treatment groups: surgery alone (61 patients) or surgery followed by 5-FU-based chemotherapy (53 patients). TS protein expression in the tumour tissue was assessed by immunohistochemistry.

RESULTS

In the surgery alone subgroup, overall survival (OS) at 5 years were 77.5% for the patients with low TS expression, against 57.7% for the patients with high TS expression (p=0.006). Among patients with low TS, there was no difference in OS as a result of whether adjuvant chemotherapy was carried out or not (65.8 vs 77.5%, p=0.29). Among the patients with high TS, there was a significant gain in OS in favor of chemotherapy (87.8 vs 57.7%, p=0.04). Analyzing the complete sample, TS expression was not shown as an independent prognostic factor for survival in the multivariate analysis.

CONCLUSIONS

The immunohistochemical TS expression may be used for selecting patients for better adjuvant chemotherapy protocols. In this sample, TS expression was not an independent prognostic factor for survival.

SELNET clinical practice guidelines for bone sarcoma

Bone sarcoma are infrequent diseases, representing < 0.2% of all adult neoplasms. A multidisciplinary management within reference centers for sarcoma, with discussion of the diagnostic and therapeutic strategies within an expert multidisciplinary tumour board, is essential for these patients, given its heterogeneity and low frequency. This approach leads to an improvement in patient's outcome, as demonstrated in several studies. The Sarcoma European Latin-American Network (SELNET), aims to improve clinical outcome in sarcoma care, with a special focus in Latin-American countries. These Clinical Practice Guidelines (CPG) have been developed and agreed by a multidisciplinary expert group (including medical and radiation oncologist, surgical oncologist, orthopaedic surgeons, radiologist, pathologist, molecular biologist and representatives of patients advocacy groups) of the SELNET consortium, and are conceived to provide the standard approach to diagnosis, treatment and follow-up of bone sarcoma patients in the Latin-American context.

The use of silicone expander and cecal transposition after pelvic exenteration

AIMS

Describe a new approach for pelvic floor treatment employing a temporary mechanical support device with silicone expander, with or without association to cecal transposition.

METHODS

From January 2000 to June 2006, 106 patients were submitted to pelvic exenteration. A retrospective evaluation was done of the last 30 patients previously submitted to total pelvic exenteration without neither urinary nor faecal sphincter preservation who latter were submitted to a pelvic floor treatment with silicone expander with or without association to cecal rotation.

RESULTS

Twenty-six patients were female and four male. The most common primary neoplasm site were of gynecological origin (20 cases). The median follow-up period was 12 months (0.36-38). Only one patient presented small intestine loops slipping after expander removal. No other patient had small intestine loops slippage into the pelvis, probably because of cecal transposition. All patients were submitted to a post-operative CT scan to confirm that intestinal loops remained out of the pelvis. Six patients presented pelvic hollow infection after device removal. All cases had complete resolution with local cleaning using physiological solution associated with systemic antibiotic therapy, except one who needed a trans-abdominal surgical approach.

CONCLUSIONS

Pelvic floor treatment employing a temporary mechanical support device with silicone expander, associated or not to cecal transposition is a low-morbidity procedure. The most common complication is pelvic floor infection, but maintaining a cutaneous perineal hole allows easy access and treatment of possible pelvic abscesses as well as early recurrence diagnosis.

Functional, Aromatic, and Fluorinated Monothiosemicarbazones: Investigations into Their Structures and Activity toward the Gallium-68 Incorporation by Microwave Irradiation

We report on the synthesis and spectroscopic characterization of a new series of coordinating monothiosemicarbazones incorporating aromatic backbones, featuring O/N/S donor centers monosubstituted with different aliphatic, aromatic, fluorinated, and amine-functionalized groups at their N centers. Their ability to bind metal ions such as Zn(II) and Ga(III) was explored, and the formation of two different coordination isomers of the Zn(II) complex was demonstrated by X-ray diffraction studies using synchrotron radiation. These studies showed the planar geometry for the coordinated mono(thiosemicarbazone) ligand and that the metal center can adopt either a heavily distorted tetrahedral Zn center (placed in an N/S/S/N environment, with CN = 4) or a pseudo-octahedral geometry, where the Zn(II) center is in the O/N/S/S/N/O environment, and CN = 6. Furthermore, 2-(4,5-dimethyl-2-thiazolyl)-3,5-diphenyl-2H-tetrazolium bromide (MTT) assays and cellular imaging in living cells were subsequently performed in two different cancer cell lines: PC-3 (a standard cell line derived from a bone metastasis of a stage IV prostate cancer) and EMT6 (a commercial murine mammary carcinoma cell line). The radiolabeling of new functional and aromatic monothiosemicarbazones with either gallium-68 (under pH control) or fluorine-18 is discussed. The potential of this class of compounds to act as synthetic scaffolds for molecular imaging agents of relevance to positron emission tomography was evaluated in vitro, and the cellular uptake of a simultaneously fluorinated and [⁶⁸Ga]-labeled mono(thiosemicarbazone) was investigated and is reported here.

Silica granulomas secondary to the explosion of a land mine

We describe a patient with multiple silica granulomas in the skin occurring fifteen years after trauma produced by the explosion of a land mine. The presence of silica in the granulomas was confirmed by x-ray microanalysis.

[Retention of knowledge. I--Dermatology and psychiatry programs]

The authors present the results of an education investigation of knowledge retention. The programs of Dermatology and Psychiatry were studied, comparing the marks obtained in the fourth and fifth years. The examinations had the same content but were not identical and the fifth year's examination was applied in the first day of the training program. The losses of knowledge observed (average +/- standard error) were 20.0 +/- 2% for Dermatology and 27.0 +/- 3% for Psychiatry. These losses were not influenced by the time between the two examinations, by student's sex or race (oriental or not), or by the fact that the student had studied the contents of the disciplines out of the University program (hidden curriculum).

Primary cancer of the head and neck

One hundred and seventy-eight cases of squamous cell carcinoma of the head and neck were reviewed. The incidence of second malignant neoplasms was 15%. The authors conclude that environmental and life-style factors contributed to the development of a second malignancy.

DNA Mismatch Repair-Deficient Colorectal Carcinoma: Referral Rate for Genetic Cancer Risk Assessment in a Brazilian Cancer Center

BACKGROUND

Approximately 15% of colorectal cancers (CRCs) are deficient in DNA mismatch repair proteins (dMMR), a characteristic that can occur in both sporadic and hereditary CRC. Due to sparse studies on dMMR CRC in the Brazilian population, we conducted a retrospective analysis of referral rates for Genetic Cancer Risk Assessment of this population and also describing clinical and molecular characterization of these tumors.

METHODS

A retrospective, longitudinal, and unicenter study that included patients with dMMR CRC detected by IHC analysis from Pathology Database of our institution, from January 2015 to July 2017.

RESULTS

MMR IHC testing was performed in 998 CRC tumors, and 78 tumors (7.8%) had dMMR. The mean age at diagnosis was 56.8 years (17-90), and most patients were female (41 out of 78, 52.6%). Of the 52 patients with right-sided CRC, 40 tumors (77%) had loss of the MLH1 and/or PMS2 expression, and 12 tumors (23%) had loss of MSH2 and/or MSH6 expression (p = 0.005). From 78 patients with dMMR CRC, only 43 patients (55.1%) were referred for genetic counseling (GC), and of them, only 33 patients (76.7%) really went to GC consultation. A total of 21 patients with dMMR CRC performed genetic testing.

CONCLUSION

Overall, genetic referral was less than expected in our population. Most of dMMR CRC patients did not receive GC, even in a cancer center, either due to the absence of referral or personal decision and few patients who pursued genetic counseling performed genetic testing.