Cadmium toxicity on the freshwater microalga Chlamydomonas moewusii Gerloff: Biosynthesis of thiol compounds

Cadmium (Cd) toxicity and production of different thiols (phytochelatins, glutathione, gamma-Glu-Cys and cysteine) were studied in the microalga Chlamydomonas moewusii exposed to different concentrations of this metal (1, 2, 4, 6, 8, and 10 mg/L) for 96 h. The inhibitory effect of Cd on growth was demonstrated. The value of EC50 (metal concentration which reduces the population growth to 50% of the control) obtained for this microalga was estimated at 4.1 +/- 0.8 mg/L of Cd after 96 h of exposure. The amount of thiol compounds synthesized by C. moewusii changed with Cd concentration. Cysteine concentrations were significantly higher compared to those of gamma-Glu-Cys and glutathione in all the Cd concentrations assayed. The amino acid cysteine reached its higher levels in those cultures in which a decrease in the concentration of phytochelatins (PCs) was observed. Both cysteine and glutathione concentrations showed significant differences along the Cd concentrations assayed, while the amount of gamma-Glu-Cys detected remained stable. The PCs detected were of two, three, and four subunits. The level of PC(2) was higher than that of PC(3) and PC(4). PC(4) was detected only in the cultures exposed to the Cd concentrations of 1 and 2 mg/L, in which the synthesis of phytochelatins was higher. A rapid increase in the production of PC(2) and PC(3) was observed up to a Cd concentration of 2 mg/L, after which their levels began to decrease. Phytochelatins were not detected in cultures without Cd (controls) and in those exposed to the maximum Cd concentration (10 mg/L), in which cell growth was completely inhibited.

Excision repair cross-complementing 1 (ERCC1) and survival in advanced bladder cancer: Confirmatory results using immunohistochemistry

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Background: DNA damaging agents are the backbone of combination chemotherapy regimens for the treatment of advanced bladder cancer. We hypothesized that levels of DNA repair genes such as ERCC1 could predict survival in patients receiving platinum based therapy. Our previous work (Bellmunt J et al, Ann Oncol. 2007) showed that survival was significantly higher in advanced bladder cancer patients with low gene expression levels of ERCC1 measured by RT-qPCR (25.4 versus 15.4 months; p = 0.03). We aimed to confirm these findings using immunohistochemistry (IHC) in an independent cohort of advanced bladder cancer patients treated with cisplatin-based chemotherapy at our institution. Methods: Formalin-fixed paraffin-embedded tumor tissue was available from 51 patients. IHC stains for ERCC1 protein levels were scored as percentage and intensity of positive cells. ERCC1 staining was considered positive if detected in ≥1% tumor cells. The Kaplan-Meier method was used to calculate survival and the Cox proportional hazards model was used to examine the prognostic value of protein expression levels. Results: ERCC1 staining was negative in 60% of patients, weakly positive (1–10% positive cells) in 21% and strongly positive (>10% positive cells) in 19%. Median overall survival for all patients was 14.4m (95% CI 6.7–16.1m). Median disease-specific survival was significantly higher in patients negative for ERCC1 by IHC (12.6m versus 8.6m; p = 0.032). Conclusions: Our results using the more simple IHC technique confirm the prognostic value of ERCC1 expression in advanced bladder cancer. Patients with high expression of ERCC1 by IHC have a worse disease-specific survival than patients with no expression. A correlative study of IHC and RT-qPCR in both sets of samples is ongoing.

No significant financial relationships to disclose.

Distinctive clinicopathological associations of amplification of the cortactin gene at 11q13 in head and neck squamous cell carcinomas

Amplification of the 11q13 region is a prevalent genetic alteration in head and neck squamous cell carcinoma (HNSCC). We investigated the clinical significance of cortactin (CTTN) and cyclin D1 (CCND1) amplification in both malignant transformation and tumour progression. CTTN and CCND1 amplification was analysed by differential and real-time PCR in a prospective series of laryngeal/pharyngeal carcinomas and archival premalignant tissues. CTTN mRNA and protein expression were respectively determined by real-time RT-PCR and immunohistochemistry, and correlated with gene status. Molecular alterations were associated with clinicopathological parameters and disease outcome. CTTN and CCND1 amplifications were respectively found in 75 (37%) and 90 (45%) tumours. Both correlated with advanced disease; however, only CTTN amplification was associated with recurrence and reduced disease-specific survival (p = 0.0022). Strikingly, CTTN amplification differentially influenced survival depending on tumour site (p = 0.0001 larynx versus p = 0.68 pharynx) and was an independent predictor of reduced survival in the larynx (p = 0.04). CCND1 amplification was detected in early tumourigenesis and increased with the severity of dysplasia. Importantly, CTTN amplification was only found in high-grade dysplasias that progressed to invasive carcinoma. CTTN gene status strongly correlated with mRNA and protein expression. Furthermore, CTTN overexpression correlated significantly with reduced disease-specific survival (p = 0.018). Taken together, these data indicate that CTTN may serve as a valuable biomarker to identify patients with laryngeal tumours at high risk of recurrence and poor outcome.

Use of a three-dimensional virtual reality model for preoperative imaging in DIEP flap breast reconstruction

BACKGROUND

The significant variation in the vascular anatomy of the abdominal wall makes preoperative imaging essential when raising a deep inferior epigastric artery perforator (DIEP) flap due to the potential for maximizing operative success, reducing intraoperative error and minimizing operative complications. Computerized models and virtual reality applications are being used to facilitate teaching and preoperative evaluation in a number of other complex anatomical regions. The variability in perforator anatomy makes DIEP flap surgery a suitable candidate for application of such technology. In this context, a study was undertaken to determine the feasibility of computed tomography angiography (CTA)-guided VirSSPA three-dimensional (3D) software for virtual reality navigation in DIEP flap surgery and to compare findings with operative measurements.

MATERIALS AND METHODS

We recruited 12 consecutive patients planned for an elective DIEP flap for breast reconstruction. Each patient underwent preoperative imaging of the anterior abdominal wall vasculature with both conventional CTA and VirSSPA 3D reconstruction. Imaging findings were compared with operative findings.

RESULTS

In all cases, the major perforators were accurately localized using both methods. 3D reconstruction of the abdominal wall with VirSSPA demonstrated a significant good correlation with perforator location compared with operative findings, showing an average error rate of 0.23cm (95% CI, 0.17-0.30).

CONCLUSION

In short, the main advantage of VirSSPA, when used in conjunction with an image assessment such as CTA, is to provide additional and potentially more accurate data over conventional CTA with regard to the site of the best perforators and its course through the muscle.

[Beta-lactam antibiotics]

Beta-lactam drugs, whose mechanism of action is inhibition of the last stage of bacterial cell wall synthesis, are the largest family of antimicrobial agents and the most widely used in current clinical practice. These drugs have a slow, time-dependent bactericidal action, generally good distribution in the body, and low toxicity. Modifications of the original molecule have led to new compounds with a greater antimicrobial spectrum and activity; nonetheless, the use and efficacy of beta-lactams is limited in some clinical settings, owing to the increasing emergence of antimicrobial resistance. Despite this problem, penicillin remains the treatment of choice in a large number of infections, cephalosporins have a wide range of indications, carbapenems are used in nosocomially-acquired infection and infection caused by multiresistant microorganisms, and beta-lactam inhibitors restore the spectrum of activity of their companion penicillins (aminopenicillins, ureidopenicillins) when resistance is caused by beta lactamase production.

[Prevalence of peripheral artery disease evaluated by ankle brachial index in patients with metabolic syndrome. MERITO I study]

INTRODUCTION

Patients with Metabolic Syndrome have high cardiovascular morbidity and mortality rate above that expected when using accepted scales for risk stratification. Ankle brachial index (ABI) is an available, straightforward and reproducible method for the detection of peripheral vascular disease and for improving risk stratification in this population. Our study aimed to evaluate the prevalence of low ABI in patients with metabolic syndrome older than 50 years and to study the risk factors associated with its development.

PATIENTS AND METHODS

1519 subjects between 50 and 85 years, 935 of them with metabolic syndrome (Adult Treatment Panel III [ATP III] criteria), in primary prevention, without symptoms of intermittent claudication and who gave their consent to have an ABI measurement in internal medicine offices were included in the study. Cardiovascular risk factors were evaluated in all participants. An ABI < 0.9 was considered low.

RESULTS

The prevalence of a low ABI in subjects with metabolic syndrome was 27.7 (95% CI: 24.8-30.5). Factors associated with low and a pathological ABI were age, higher serum creatinine levels and presence of proteinuria. After multivariate adjustment, only age (OR: 1.07; 95% CI: 1.04-1.09) and active tobacco use (OR: 1.45; 95% CI: 1.10-1.92) continued to be significant.

CONCLUSION

Prevalence of a low ABI is elevated in subjects with metabolic syndrome without known cardiovascular disease and related with age and active tobacco use.

Health Care–Associated Pneumonia Requiring Hospital Admission

BACKGROUND

Health care-associated pneumonia (HCAP) has been proposed as a new category of respiratory infection. However, limited data exist to validate this entity. We aimed to ascertain the epidemiology, causative organisms, antibiotic susceptibilities, and outcomes of and empirical antibiotic therapy for HCAP requiring hospitalization.

METHODS

Observational analysis of a prospective cohort of nonseverely immunosuppressed hospitalized adults with pneumonia. Patients who had recent contact with the health care system through nursing homes, home health care programs, hemodialysis clinics, or prior hospitalization were considered to have HCAP.

RESULTS

Of 727 cases of pneumonia, 126 (17.3%) were HCAP and 601 (82.7%) were community acquired. Compared with patients with community-acquired pneumonia, patients with HCAP were older (mean age, 69.5 vs 63.7 years; P < .001), had greater comorbidity (95.2% vs 74.7%; P < .001), and were more commonly classified into high-risk pneumonia severity index classes (67.5% vs 48.8%; P < .001). The most common causative organism was Streptococcus pneumoniae in both groups (27.8% vs 33.9%). Drug-resistant pneumococci were more frequently encountered in cases of HCAP. Legionella pneumophila was less common in patients with HCAP (2.4% vs 8.8%; P = .01). Aspiration pneumonia (20.6% vs 3.0%; P < .001), Haemophilus influenzae (11.9% vs 6.0%; P = .02), Staphylococcus aureus (2.4% vs 0%; P = .005), and gram-negative bacilli (4.0% vs 1.0%; P = .03) were more frequent in HCAP. Patients with HCAP more frequently received an initial inappropriate empirical antibiotic therapy (5.6% vs 2.0%; P = .03). The overall case-fatality rate (< 30 days) was higher in patients with HCAP (10.3% vs 4.3%; P = .007).

CONCLUSIONS

At present, a substantial number of patients initially seen with pneumonia in the emergency department have HCAP. These patients require a targeted approach when selecting empirical antibiotic therapy.

Human DESC1 serine protease confers tumorigenic properties to MDCK cells and it is upregulated in tumours of different origin

Proteolysis of the extracellular matrix components plays a crucial role in the regulation of the cellular and physiological processes, and different pathologies have been associated with the loss or gain of function of proteolytic enzymes. DESC1 (differentially expressed in squamous cell carcinoma gene 1), a member of the TTSP (type II transmembrane serine protease) family of serine proteases, is an epithelial-specific enzyme that has been found downregulated in squamous cell carcinoma of the head and neck region. We describe new properties of DESC1 suggesting that this protease may be involved in the progression of some type of tumours. Thus, this enzyme hydrolyses some extracellular matrix components, such as fibronectin, gelatin or fibrinogen. Moreover, Madin–Darby canine kidney (MDCK) cells expressing exogenous human DESC1 acquire properties associated with tumour growth such as enhanced motility and an increase of tubular forms in a 3D collagen lattice following HGF treatment. Finally, we generated polyclonal anti-DESC1 antibodies and immunohistochemical analysis in tissues different from head and neck region indicated that this protease was overexpressed in tumours of diverse origins. Taken together, our results suggest that DESC1 could be considered as a potential therapeutic target in some type of tumours.