Sensitive vs. tolerant Nitzschia palea (Kützing) W. Smith strains to atrazine: a biochemical perspective.

Organic contaminants, and herbicides in particular, represent a risk for aquatic ecosystems. The primary target of herbicides are producers, the base of food webs, but frequently they end up far from the application point affecting non-target species. Its presence can work as sub-lethal stimulus, which sort the genetic and phenotypic differences within a species. Intraspecific variation allows adaptation to changes in the environment but also to new niches due to variations in species' sensitivity and biochemical response to a certain chemical. A better understanding of these variations can lead to the development of improved strategies for ecosystem protection. This research aimed to compare a sensitive and a tolerant strain of the freshwater diatom Nitzschia palea to atrazine. Strains were exposed to three concentrations within their tolerance range, during 96 h. The activity of the antioxidant enzymes superoxide dismutase, catalase, glutathione-S-transferases and glutathione peroxidases was determined. In addition, chlorophylls a and c, carotenoids, reduced glutathione, proteins and lipid peroxidation were quantified. Both strains displayed different strategies to deal with atrazine toxicity: while the sensitive strain decreased the oxidative stress, increasing the activity of antioxidant enzymes such as superoxide dismutase, the tolerant strain invested in conjugation pathways and carotenoids' maintenance.

Zostera noltei response to transplantation into historically Hg-contaminated sediments (A mesocosm experiment): Growth, bioaccumulation and photosynthetic performance.

The present study aimed to evaluate the effectiveness of seagrass recolonization as a nature-based solution for the recovery of a coastal area historically contaminated by mercury (Laranjo Bay, Ria de Aveiro, Portugal). A mesocosm approach was employed to assess the resistance of Zostera noltei to transplantation into contaminated sediments collected in-situ (0.5-20 mg kg-1 Hg). At each sampling time (15, 30, 60, 120 and 210 days), the resistance of transplanted Z. noltei was evaluated through growth parameters (biomass and coverage area), photosynthetic performance and elemental composition. Although some significant differences (p ≤ 0.05) were observed between treatments, essentially associated with the elemental composition of plant tissues, the most relevant variations were associated with seasonality. Overall, plants were found to not be affected by sediment contamination, under the tested concentrations, suggesting that recolonization with Z. noltei can be an effective restoration strategy for historically contaminated coastal areas.

Metal(oid)s accumulation (Hg and As) and their biochemical effects in Halimione portulacoides (Ria de Aveiro, Portugal).

For decades, mercury (Hg) and arsenic (As) were discharged into the Aveiro Lagoon. This study was designed to assess the natural attenuation process evolution by: (1) evaluating Hg and As concentration in sediments and in Halimione portulacoides, and assess the long-term evolution of a historically contaminated salt-marsh system; (2) evaluating the stress levels imposed by Hg and As, and the mechanisms triggered to squash oxidative damage. Concentrations of Hg and As in sediments varied considerably between sampling locations. H. portulacoides did not bioconcentrate Hg and As, restricted translocation to aerial biomass and immobilized contaminants in cell walls. The ions that reached the cytosol induced oxidative stress, restrained by antioxidant mechanisms, especially SOD and CAT activity. Results show that after 25 years of natural attenuation, contamination decreased in the sediment, but remains above non-contaminated systems and continues to induce toxicity in the saltmarsh halophyte community, evidencing the persistent effect of Hg and As contamination.

Proregion of Acanthoscelides obtectus cysteine proteinase: a novel peptide with enhanced selectivity toward endogenous enzymes.

Acanthoscelides obtectus is a devastating storage insect pest capable of causing severe bean crop losses. In order to maintain their own development, insect pest larvae feed continuously, synthesizing efficient digestive enzymes. Among them, cysteine proteinases (CPs) are commonly produced as inactive precursors (procysteines), requiring a cleavage of the peptide proregion to become active. The proregion fits tightly into the active site of procysteines, efficiently preventing their activity. In this report, a CP cDNA (cpao) was isolated from A. obtectus midgut larvae. In silico studies indicated that the complete CP sequence contains a hydrophobic signal peptide, a prodomain and a conserved catalytic region. Moreover, the encoding cDNA contains 963bp translating into a 321 residue protein, CPAo, which was expressed in E. coli, fused with thioredoxin. Enzymatic assays using the recombinant protein revealed that the enzyme was catalytically active, being able to cleave the synthetic substrate Z-Phe-Arg-7-AMC. Additionally, this report also focuses the cpao propeptide (PCPAo) subcloning and expression. The expressed propeptide efficiently inhibited CPAo, as well as digestive CP of other bean bruchids. Little or no activity was found against proteolytic enzymes of two other coleopterans: Rhyzopertha dominica and Anthonomus grandis. The data reported here indicate the possibility of endogenous propeptides as a novel strategy on bruchids control, which could be applicable to bean improvement programs.

Preventing conjunctival autograft inversion in pterygium surgery.

BACKGROUND: Surgeon-dependent variables influencing pterygium surgical outcome using the conjunctival autograft technique include conjunctival retraction as a consequence of subepithelial contracting fibrous tissue, and autograft inversion causing necrosis and sloughing of the graft. METHOD: A simple and useful technique of pterygium excision is described, which helps to ensure the correct surface and linear orientations of the conjunctival autograft, and also defines the end point of adequate excision of the subepithelial connective tissue. CONCLUSION: This simple technique of defining the anterior surface and the centrifugal orientation with the letter "G" marked on the graft prevents reverse orientation of the graft.

Biliary reconstruction without T-tube in liver transplantation.

Biliary complications have been reported in 9% to 34% of liver transplant patients. Although most centers seem to prefer a duct-to-duct anastomosis without a T-tube when feasible, the best method of biliary reconstruction remains controversial. The aim of this study was to review our experience on reconstruction of the biliary tract without drainage. Forty-one patients underwent 45 liver transplants over two periods. Forty patients underwent 15 liver transplants from October 1992 to March 1995; and 27 underwent 30 liver transplants from January 2002 to February 2003. Our standard biliary reconstruction was an end-to-end anastomosis without drain. The overall actuarial survival was 72.7% at 1 year, 64.7% at 3 years, and 56.6% at 5 years. The mean follow-up was 23 months. Eight patients (22.2%) developed biliary tract complications: five patients papillary dysfunction (13.9%); two, biliary stricture (5.5%); and one, biliary sludge without evidence of stricture (2.8%). Papillary dysfunction represented 62.5% of all complications. Biliary reconstruction without drainage may be routinely performed since the complications are only those not related to the T-tube.

Early mortality in liver transplantation: bilirubin as predictor of outcome.

The shortage of donor organs and the long waiting lists have increased the need to better select liver transplant candidates using predictors of success. We reviewed the results of 29 liver transplantations performed from January 2002 to February 2003 analyzing the correlations with early mortality (30 days) of patient data, pretransplant laboratory data, warm ischemia time, intraoperations blood unit transfusions, and postoperative complications of prolonged mechanical ventilation, dialysis, and infection. Overall early mortality was 27.6% and 44% in fulminant hepatic failure (n = 9), there were four retransplants with one death, and two intraoperative deaths. Only pretransplant bilirubin (P =.045) and postoperative lactate levels (P =.002) were significantly different between alive versus dead patients. In this small population bilirubin was more related to death than the MELD score. Lactate levels, nonspecific predictor of death in shock syndromes were probably related to septic complications.

Trematode communities in cockles (Cerastoderma edule) of the Ria de Aveiro (Portugal): influence of inorganic contamination.

This work aims to assess the trematode parasites infecting the edible cockle Cerastoderma edule, collected in the Ria de Aveiro lagoon, one of the most relevant biodiversity hotspots of the Western Iberia, and evaluate the relationship between the observed patterns and environmental descriptors. A total of 11 of the 16 trematode species known to infect C. edule were identified, including Himasthla continua and Psilostomum brevicolle as new occurrences in this lagoon. Parvatrema minutum was the most abundant and dominant species. Species richness and prevalence were high. The relationship between trematode species abundance, intensity and prevalence, and also environmental variables, showed that most parasites preferred muddy sand areas with euhaline conditions in opposition to areas with contamination and/or distant from the lagoon entrance. This study highlighted the good ecological status of the ecosystem and the transitional biogeographic characteristics of the western Portuguese coast where northern and subtropical faunas can coexist.

Biochemical effects of acetaminophen in aquatic species: edible clams Venerupis decussata and Venerupis philippinarum.

Acetaminophen (paracetamol) is one of the most used pharmaceutical drugs, due to its antipyretic and analgesic properties that turn it into a primary choice in varied pathologies and conditions. However, and despite its massive use, acetaminophen is not exempt of adverse effects, especially when administered in over dosage, which are related to the formation of toxic metabolites by oxidative pathways. It is thus possible to observe that toxicity caused by acetaminophen is usually mediated by reactive oxygen species and can result in multiple effects, ranging from protein denaturation to lipid peroxidation and DNA damage. The occurrence of acetaminophen has been reported in the aquatic environment, being important to address the potential exertion of toxic effects on nontarget environmentally exposed organisms. The present study intended to characterize the effects of acute acetaminophen exposure on physiological traits (antioxidant defense, oxidative damage) of two species of bivalves, namely, the edible clams Venerupis decussata and Venerupis philippinarum. Results showed a significant increase in all oxidative stress biomarkers, evidencing the bioactivation of acetaminophen into a deleterious prooxidant, triggering the onset of deleterious effects. Furthermore, strong interspecific differences were observed among responses of the two tested species, which was a major issue due to intrinsic ecological implications when one considers that both species share the same habitat.

Mercury intracellular partitioning and chelation in a salt marsh plant, Halimione portulacoides (L.) Aellen: strategies underlying tolerance in environmental exposure.

In the presence of metal stress, plants can resort to a series of tolerance mechanisms. Therefore field studies should be undertaken in order to evaluate the real role of these mechanisms in stress coping. The aim of this paper was to clarify the biochemical processes behind mercury tolerance in Halimione portulacoides (L.) Aellen (Caryophyllales: Chenopodiaceae) collected in a mercury contaminated salt marsh. Different fractions of mercury were separated: buffer-soluble (mainly cytosolic) and insoluble mercury (mainly associated with membranes and cell walls). The amounts in each fraction of metal were compared and related to metal distribution within plant organs. Protein-mercury complexes were isolated and analysed for their thiol content in order to assess wether the tolerance of this salt marsh plant was associated with the induction of metal chelation by phytochelatins. Overall, the mercury tolerance strategies of the plant are likely to involve root cell wall immobilization as a major mechanism of metal resistance, rather than metal chelation in the cytosolic fraction. Nevertheless, phytochelatins were demonstrated to chelate mercury under environmental exposure.

Effect of laser therapy combined with biomaterials for treatment of periodontal bone defects

Objective: Evidence has shown that laser therapy can have a positive effect on the regeneration of periodontal tissues and improve the postoperative period through its antiinflammatory properties. The aim of the present review was to assess the effects of low-level and high-level laser in combination with different biomaterials on the regeneration of periodontal tissues in infrabony defects and furcation lesions. Materials and Methods: An electronic search of the PubMed database was performed, using ten specific descriptors. The search strategy gave 232 papers, 45 of which were initially selected based on the title, and following the reading of the abstracts, six of them were selected. After a complete reading of the texts, two papers were excluded for not fulfilling the inclusion criteria. Results: Thus, four papers were included in the present review, two of which employed low-level laser and two employed high-level laser in combination with enamel matrix derivative and bioactive glass. Non-significant results were found in the comparison of irradiated and non-irradiated groups using high-level laser, whereas statistically significant differences favoring the irradiated group were found with the use of low-level laser. Conclusions: Based on the data analyzed, low-level laser therapy has a positive effect on the regeneration of periodontal tissues, while high-level laser seems not to enhance the effect of enamel matrix derivative in the regeneration process.

The Lanindar test: a method of evaluating patient suitability for cataract surgery using assisted topical anaesthesia.

AIM: To evaluate an office-based Lanindar (light and nociceptive interaction noting distress and response) test to assist in the assessment of patient suitability for assisted topical anaesthesia (ATA) during phacoemulsification. METHODS: The Lanindar test was carried out at the preoperative assessment of 716 consecutive patients in the office of one of the authors (ICF). A standard desk lamp was shone in each patient's eye after pupillary dilation, while simultaneously elevating the upper eyelid digitally. A negative test indicated patient hypersensitivity to the light and aversion to digital pressure on the upper eyelid. A positive test was indicated by the patient feeling comfort and lack of blepharospasm and withdrawal in response to the light and digital pressure. chi (2) and Fisher's exact tests were used to assess the association between Lanindar results and suitability for ATA. The positive predictive value and specificity of the test as an indicator of patient suitability for ATA were calculated. Visual acuities at 1 and 4 weeks post-operative periods were compared between the ATA and ALA/GA (assisted local anaesthesia/general anaesthesia) group of patients. RESULTS: About 86.7% were Lanindar positive and 98.9% of these patients tolerated ATA. chi (2) and Fisher's exact tests demonstrated a significant association of a positive Lanindar test with successful ATA (chi (2)=660, P<0.001, Fisher's: P<0.001). The positive predictive value and specificity of the test were 98% (95% CI=98.04-99.7%) and 93.14% (95% CI=88.23-98.04%), respectively. Visual acuity outcomes were similar in the ATA and ALA/GA groups. CONCLUSION: The Lanindar is a simple, highly specific, office-based test to determine patient suitability for phacoemulsification under ATA.

Patient perceptions of second eye clear corneal cataract surgery using assisted topical anaesthesia.

AIM: To assess patient recall of intraoperative pain, anxiety, fear, and sensory (visual and auditory) perceptions during second eye clear corneal cataract surgery using assisted topical anaesthesia (ATA), in comparison with first eye cataract surgery using the same technique. METHODS: This prospective, consecutive, observational study was conducted in a free-standing dedicated ophthalmic day surgery centre. A voluntary questionnaire was distributed to 129 consecutive patients who underwent clear corneal cataract surgery using ATA. Two patients had to be converted to block anaesthesia, and were excluded. Patients were asked to rate intraoperative pain, anxiety, and fear using a visual analogue scale (VAS), and recollection of intraoperative visual and auditory perceptions. Results were analysed using the Mann-Whitney U and Spearman correlation tests. RESULTS: There were 70/127 (55%) patients undergoing first eye cataract surgery and 57/127 (45%) undergoing second eye surgery. There was no significant difference in mean pain, anxiety, and fear scores between those undergoing the second eye operation compared with those undergoing their first eye operation. Similarly, there was no significant difference in sensory perceptions between the two cohorts. Overall, there was a small but significant positive correlation between recall of visual and auditory perceptions and combined pain, fear, and anxiety scores (r=0.33, P=0.0002). CONCLUSION: There was no significant difference in levels of intraoperative pain, anxiety, fear, and sensory perceptions experienced by patients between the first eye and second eye surgeries. We recommend that preoperative counselling for a patient's second eye be as comprehensive as for the first eye surgery.

Randomized clinical trial of the effectiveness of emergency day surgery against standard inpatient treatment.

BACKGROUND: The aim of this study was to assess the feasibility of treating patients with minor and intermediate general surgical emergency conditions as day cases. METHODS: Emergency referrals for minor and intermediate general surgical conditions were assessed by a surgeon. Those fitting day-case criteria and requiring operation under general anaesthesia were randomized to receive standard inpatient care or day surgery. Patients in the latter group were booked on to day-case lists or gaps on inpatient elective lists for surgery within 48 h. The process was coordinated by an experienced theatre sister. RESULTS: One hundred patients were randomized. There was a reduction in the number of nights spent in hospital in the day-case group (median 0 versus 2 nights; P < 0.001). The median time from diagnosis to treatment was 1 day in both groups, although there was a small but significant delay in the day-case group (P = 0.018). There was no significant difference in postoperative outcome or patient and general practitioner satisfaction. The day-case option had no increased impact on primary care services but was associated with a significant saving of about pound sterlings 150 per patient (P < 0.001). CONCLUSION: Certain general surgical emergencies may be managed as day cases with cost saving but without detriment to patient care.

Genital trauma due to animal bites.

PURPOSE: Animal bites to the external genitalia are rare. We retrospectively evaluated our experience with treating genital trauma caused by animal attacks. MATERIALS AND METHODS: We studied the medical records of 10 patients treated in the surgical emergency department at our hospital who presented with genital injury caused by an animal bite from 1983 to 1999. Special attention was given to the severity of injury, surgical treatment, antibiotic prophylaxis and outcome. RESULTS: Of the 2 men and 8 boys 8 were attacked by dogs, 1 by a horse and 1 by a donkey, respectively. In all cases initial local treatment involved débridement and copious wound irrigation with saline and povidone-iodine solution. Five patients who presented with minimal or no skin loss underwent primary skin closure, including 2 in whom urethral lacerations were surgically repaired. There was moderate to extensive tissue loss in 5 patients, including degloving penile injury in 2, traumatic spermatic cord amputation in 1, complete penile and scrotal avulsion in a 5-month-old infant, and partial penectomy in 1. Reconstructive procedures provided satisfactory cosmetic and functional results in 8 cases. Antibiotic prophylaxis was administered in all patients and no infectious complications developed. CONCLUSIONS: Animal bite is a rare but potentially severe cause of genital trauma and children are the most common victims. Morbidity is directly associated with the severity of the initial wound. Because patients tend to seek medical care promptly, infectious complications are unusual. Management involves irrigation, débridement, antibiotic prophylaxis, and tetanus and rabies immunization as appropriate as well as primary wound closure or surgical reconstruction. Good functional and cosmetic results are possible in the majority of cases.

Nitric oxide and cellular immunity in experimental cutaneous leishmaniasis.

We examined the local and systemic production of nitric oxide (NO) and the pattern of cytokine during the course of Leishmania mexicana infection in susceptible BALB/c and resistant C57BL/6 mice. NO derivatives were measured in serum, and the expression of inducible nitric oxide synthase (iNOS), interferon (IFN-gamma), interleukin (IL-4) and epidermal Langerhans cells (LC) was measured in the lesions by immunohistology. Circulating NO concentrations, iNOS+ cell density, IFN-gamma+ Th1 cells and CD205+ Langerhans cells were higher in early lesions of resistant C57BL/6 mice. In contrast, susceptible BALB/c mice developed chronic and progressive lesions with a predominance of IL-4+ Th2 cells. In both susceptible and resistant mice, lesion size and lymph node volume followed a similar course. The early local and systemic production of NO in resistant mice may be related with the premature production of IFN-gamma observed, contributing to the resolution of the lesion.