Disentangling functional trait variation and covariation in epiphytic lichens along a continent-wide latitudinal gradient

Characterizing functional trait variation and covariation, and its drivers, is critical to understand the response of species to changing environmental conditions. Evolutionary and environmental factors determine how traits vary among and within species at multiple scales. However, disentangling their relative contribution is challenging and a comprehensive trait-environment framework addressing such questions is missing in lichens. We investigated the variation in nine traits related to photosynthetic performance, water use and nutrient acquisition applying phylogenetic comparative analyses in lichen epiphytic communities on beech across Europe. These poikilohydric organisms offer a valuable model owing to their inherent limitations to buffer contrasting environmental conditions. Photobiont type and growth form captured differences in certain physiological traits whose variation was largely determined by evolutionary processes (i.e. phylogenetic history), although the intraspecific component was non-negligible. Seasonal temperature fluctuations also had an impact on trait variation, while nitrogen content depended on photobiont type rather than nitrogen deposition. The inconsistency of trait covariation among and within species prevented establishing major resource use strategies in lichens. However, we did identify a general pattern related to the water-use strategy. Thus, to robustly unveil lichen responses under different climatic scenarios, it is necessary to incorporate both among and within-species trait variation and covariation.

A case study on the re-establishment of the cyanolichen symbiosis: where do the compatible photobionts come from?

BACKGROUND AND AIMS

In order to re-establish lichen symbiosis, fungal spores must first germinate and then associate with a compatible photobiont. To detect possible establishment limitations in a sexually reproducing cyanolichen species, we studied ascospore germination, photobiont growth and photobiont association patterns in Pectenia plumbea.

METHODS

Germination tests were made with ascospores from 500 apothecia under different treatments, and photobiont growth was analysed in 192 isolates obtained from 24 thalli. We determined the genotype identity [tRNALeu (UAA) intron] of the Nostoc cyanobionts from 30 P. plumbea thalli from one population. We also sequenced cyanobionts of 41 specimens of other cyanolichen species and 58 Nostoc free-living colonies cultured from the bark substrate.

KEY RESULTS

Not a single fungal ascospore germinated and none of the photobiont isolates produced motile hormogonia. Genetic analyses revealed that P. plumbea shares Nostoc genotypes with two other cyanolichen species of the same habitat, but these photobionts were hardly present in the bark substrate.

CONCLUSIONS

Due to the inability of both symbionts to thrive independently, the establishment of P. plumbea seems to depend on Dendriscocaulon umhausense, the only cyanolichen species in the same habitat that reproduces asexually and acts as a source of appropriate cyanobionts. This provides support to the hypothesis about facilitation among lichens.

Prognostic Factors and Results of Radiation Therapy in Optic Pathway Tumors

Aims and Background

The role of radiotherapy in the management of patients with optic pathway tumors remains controversial. This study analyzes the outcome of patients treated with radiotherapy and attempts to identify the groups of patients that may require early therapy.

Methods

We retrospectively reviewed 36 patients with optic pathway tumors treated with radiotherapy alone (26 patients) or with postoperative radiotherapy (10 patients). Seven patients had optic nerve tumors and 29 patients had chiasmal tumors. The actuarial progression free survival and observed survival probabilities were calculated using the Kaplan-Meier method and differences between curves were evaluated by the Mantel-Cox test. The obtained significant variables in the univariate analysis were analyzed using the Cox proportional hazards model.

Results

The 10-year actuarial progression-free survival (10-y PFS) rate was 86% for patients with optic nerve gliomas and 47% for patients with chiasmal tumors. The 10-year actuarial observed survival (10-y OS) rate was 75% for patients with optic nerve gliomas and 53% for patients with chiasmal gliomas. In the group of patients with chiasmal tumors, progression-free survival and observed survival rates were significantly lower in infants (10-y PFS: 30%; 10-y OS: 37%), in patients with neurological deficits (10-y PFS and 10-y OS: 23%), in patients with signs of elevated intracranial pressure (10-y PFS and 10-y OS: 9%), with hydrocephalus (10-y PFS and 10-y OS: 0%), or with impairment of consciousness (10-y PFS and 10-y OS: 17%). Evaluation by computed tomography scanning was associated with a significantly higher probability of PFS. Radiation doses lower than 50 Gy were associated with significantly lower PFS and OS rates. In the Cox multivariate analysis, presence of neurological deficits and radiation dose significantly influenced observed survival. Presence of hydrocephalus significantly influenced progression-free survival.

Conclusions

The prognosis of patients with chiasmal gliomas presenting with neurologic deficits is poor and should be treated at diagnosis. A minimum tumor dose of 50 Gy is recommended.

Blend design tools for Medium Combustion Plants (MCP) firing biomass wastes

A feasible alternative for agricultural or forestry waste management is the operation of a distributed network of sustainable Medium Combustion Plants (MCPs). However, one of the main factors that hinder its development is the propensity to operational problems derived from corrosion, slagging and fouling characteristics of both bottom and fly ashes. Therefore, a cost-effective approach for these multi-product MCP could be based on predictive tools for an optimal formulation of a fuel blend. This work focuses on the assessment of the ability of these methods to provide guidance for preventing ash-related operational problems and to provide fuel-blending rules. The more widespread tools pertain to two types: compositional classification based on chemical analysis of laboratory ashes, and thermodynamic prediction of the most likely species and phases. Both criterion numbers and compositional maps are ranking methods based on the chemical analysis at a given ashing temperature. Thermodynamic equilibrium modeling is not constrained by any difference in the physical conditions of the MCP compared to those in the laboratory. Both kind of prediction tools have been validated in an MCP firing olive tree pruning residues as well as its typical blends in order to mimic a plausible pattern of fuels along a full year operating campaign. An intensive experimental campaign encompasses plant monitoring and off-line analysis of the ashes along the process line. Interpretation of compositional plots has revealed to be potentially sensitive to ashing temperature. Here are presented examples showing how this variable could lead to either insignificant differences or to a substantial disparity in the a priori fuel diagnosis. Some inconsistencies have been observed between the predictions based on criterion numbers, even for the same fuel and for ranking rules specifically formulated for biomasses. Moreover, it does not match consistently with the information obtained from phase diagrams. Therefore, their use should be limited to the case of a well-established selection of a fuel index for a well-defined fuel provided empirical evidence of an enough good description of the ash behavior, which is not the most frequent case. Thermodynamic equilibrium calculations allow a more precise prediction of the main species in the condensed phase, without the constraint of the ashing temperature. Elemental closure of main ash-forming elements with the chemical analysis of the process ashes presents small differences, and their proximity localization on the phase diagrams denote similar prediction between predicted and process ashes.

Candida infection of cerebrospinal fluid shunt devices: report of two cases and review of the literature

Use of CSF shunt devices is a common practice in neurosurgery, and infection of the shunt is the most frequent complication. In spite of the fact that bacteria are the most widely implicated pathogens, reports of fungal infections, especially due to Candida sp., have increased in recent years. Their reported frequency ranges between 6% and 17%. Many factors have been implicated in the pathogenesis of Candida meningitis, such as broad spectrum antibiotics used in the treatment of a bacterial meningitis, steroids and indwelling bladder and intravenous catheters. The treatment of Candida meningitis still consists of systemic antifungal agents and removal of the shunt.

[Multicenter double-blind clinical trial comparing sucralfate vs placebo in the prevention of diarrhea secondary to pelvic irradiation]

BACKGROUND

Sucralfate has been used in the prophylaxis of acute enteric toxicity induced by radiation therapy of pelvic organs. The aim of the study was to demonstrate the efficacy of sucralfate in the prevention of the acute enteric toxicity induced by pelvic irradiation in cancer patients, compared with placebo, in a multicentric double-blind randomised clinical trial.

PATIENTS AND METHOD

One hundred and twenty patients, with a localised pelvic cancer, 18 to 80 years old, with a Karnofsky index of 80% or more, and "normal" defecation habits (3-10 defecations/week), undergoing whole pelvic irradiation, were included. The duration of the study was 7 weeks, with weekly controls. The first week all patients received placebo. In the second week the patients were randomised into two groups: sucralfate (61 patients, 2 g/tid p.o. before meals) and placebo (59 patients). Radiotherapy started at the beginning of the third week and lasted until the end of the study. All patients received 45-50 Gy total dose (1.8-2 Gy/day, 5 days/week) with the "box technique". The main variables were the number of stools per week and the number of loperamide pills per week.

RESULTS

The number of stools per week showed no differences between groups. By the contrary in the group intention to treat (120 patients) and per protocol (100 cases) the percentage of diarrhoeal stools per week showed a statistical significance in favour of sucralfate: (p < 0.05) and (p < 0.03) respectively, concerning the evolution of this variable from the baseline (first week) to the end of the pelvic radiotherapy (seventh week). Furthermore, the consumption of loperamide was significantly lower in the sucralfate group (p < 0.001).

CONCLUSION

Sucralfate is effective in the preparation of acute enteric toxicity induced by pelvic irradiation.

Phase II study of radiochemotherapy with UFT and low-dose oral leucovorin in patients with unresectable rectal cancer

PURPOSE

To determine the activity and evaluate the toxicity of uracil and tegafur in a 4:1 molar concentration (UFT) plus low-dose leucovorin administered concomitantly with pelvic irradiation in patients with unresectable or recurrent rectal cancer.

METHODS AND MATERIALS

Thirty-five patients (22 with primary unresectable tumors and 13 with locally recurrent tumors) were enrolled in the trial. Thirty-five patients were evaluable for toxicity and 32 of these were evaluable for clinical response. Patients received 300 mg/m2/day UFT and 30 mg/day leucovorin on days 8-35 concomitantly with pelvic radiotherapy, to a total dose of 45 Gy.

RESULTS

Eight of the 35 (23%) patients developed Grade 3 diarrhea and were treated with radiotherapy alone after this event. Of the 22 patients with unresectable primary tumors, 17 underwent surgery, and resection was feasible in 15 cases (88%). Of the 32 patients evaluable for clinical response, 4 (13%) had a complete clinical response (CR) and 22 (69%) a partial response (PR). A complete pathologic response was observed in 3 cases (18%) and, a PR in 11 cases (65%).

CONCLUSION

The response rates achieved with this schedule seem comparable to those obtained with 5-FU and radiotherapy. These results warrant further evaluation of this combination in patients with unresectable or locally advanced tumors.

Influence of boost technique (external beam radiotherapy or brachytherapy) on the outcome of patients with carcinoma of the base of the tongue

We reviewed 90 patients with squamous cell carcinoma of the base of the tongue. Fifty-three patients were treated with external beam radiotherapy alone (3 T1, 11 T2, 21 T3, and 18 T4 tumors) and thirty-seven patients were treated with external beam radiotherapy plus brachytherapy boost (4 T1, 15 T2, 11 T3, and 7 T4 tumors). For patients with T1, T2 and T3 primaries, the actuarial 3-year local relapse-free survival was 42% following external beam radiotherapy alone and 67% following external beam radiotherapy plus brachytherapy (p < 0.05). The actuarial 3-year cause specific survival for these T-stages was 37% for patients treated with external beam radiotherapy alone and 53% for patients treated with external beam radiotherapy plus brachytherapy (p = 0.1). In the Cox multivariate analyses restricted patients with T1, T2 and T3 staged tumors, treatment modality was the only predictor for local control but no influence on specific survival was found. The trend towards significant differences in specific survival found in the univariate comparison of both treatment modalities was probably due to the significantly higher number of N-positive patients treated with external beam radiotherapy alone. When all stages were included in the Cox analysis, low hemoglobin level, invasion of deep muscle, number of palpable nodes, and history of weight loss significantly influenced the outcome. Soft tissue necrosis occurred more frequently in patients treated with external beam radiotherapy plus brachytherapy (33% vs. 10%, p = 0.52).

Salvage brachytherapy and salvage surgery for recurrent oropharyngeal carcinoma following radiotherapy

We reviewed 21 patients who underwent salvage treatment after a biopsy of proven locally recurrent carcinoma of the oropharynx. Two of these patients underwent a second salvage treatment after failure of the first. Treatment was performed with Ir192 interstitial implant in 17 cases (13 rT1 and 4 rT2); by surgery in five cases (3 rT1, 1 rT2, 1 rTx), including two patients who had relapsed after salvage treatment with Ir192 implant; and by hyperfractionated external beam irradiation plus concomitant Tegafur chemotherapy in one case (rT3). The primary tumour was controlled in four of the 17 cases (23 per cent) treated with Ir192 implant. Of these four patients, two remained disease-free 42 and 59 months after treatment, one died of nodal metastases eight months after treatment and another of distant metastases 19 months after treatment. Four of the five cases (80 per cent) treated with surgery, including two patients who relapsed after salvage brachytherapy, remained free from local, regional and distant relapse 21, 25, 31 and 56 months after treatment.

Episcleral iridium-192 wire therapy for choroidal melanomas

PURPOSE

To evaluate the effectivity of high-dose episcleral iridium-192 wires in the treatment of choroidal melanoma.

METHODS AND MATERIALS

In 1983, the Departments of Radiation Oncology and Ophthalmology at the Clínica Puerta de Hierro, Madrid, Spain, initiated a clinical study using removable episcleral iridium-192 wires in the treatment of choroidal melanoma. Sixty-six evaluable patients were treated from January 1983 through July 1992. Two patients had a small sized tumor (3%), 28 had a medium sized tumor (42%), and 36 patients had a large tumor (54%). The mean follow-up was 40 months (6-118 months). The dose to the apex of the tumor ranged from 66 to 97 Gy (mean 76.6 Gy), and the doses at 2 mm depth ranged from 77 to 433 Gy (mean 200 Gy).

RESULTS

Tumor regression or stabilization was observed in 53 of the 66 patients (90%). Visual acuity improved following treatment in 5 out of 54 patients (9%), remaining unchanged in 30 out of 54 (56%), and decreased in 19 out of 54 (35%) patients. The remaining seven patients had undergone enucleation. Late complications have been documented in 20 out of 66 patients (30%), including 6 patients in whom enucleation was required because of radiation-related complications. The probability of survival and survival free of local progression was 93% at 5 years and 79% at 10 years. The probability of retaining the treated eye is 82% after the fifth year posttreatment.

CONCLUSIONS

Treatment of choroidal melanomas with episcleral iridium-192 wires is as effective as treatment with other radioactive applications. We feel that our results using iridium-192 wires are comparable to the other methods. However, we think that our technique is simple to implement, relatively inexpensive, and well tolerated.

Prognostic factors for local control, regional control and survival in oropharyngeal squamous cell carcinoma

We have performed univariate and multivariate analysis to identify the clinical and treatment-related prognostic factors in a series of 254 patients with newly diagnosed, histologically proven, oropharyngeal squamous cell carcinoma treated with radical radiation therapy. The probabilities of local control, regional control, disease-free survival (DFS) and adjusted survival (AS) were calculated using the Kaplan-Meier method and differences between curves were evaluated by the Mantel-Cox test. The obtained significant variables in the univariate analysis were analysed using the Cox proportional hazards model. In the Cox multivariate analysis, four variables significantly influenced local control probability in the following order: tumour diameter, N stage, alcohol intake and weight loss. N stage significantly influenced the probability of regional control. Five variables influenced both DFS and AS: N stage, tumour diameter, weight loss, alcohol intake and tumour origin within the posterior oropharyngeal wall.

Prognostic factors for survival and tumor control in cervical lymph node metastases from head and neck cancer. A multivariate study of 492 cases

A multivariate analysis was carried out in 492 patients with metastatic neck disease from squamous cell carcinoma to determine the influence of clinical and therapeutic factors on survival, local and regional control, and distant metastases. After radiation treatment with radical intent, recurrence at the primary site was the most frequent site of treatment failure (20% of cases), followed by distant metastases (14% of the cases), whereas isolated neck recurrences occurred in only 7% of the patients. The most significant factors influencing survival were primary tumor site, node fixation, N-stage, T-stage, and number of lymphatic chains. The most significant factors influencing local control were primary site, T-stage, and node fixation. Significant factors influencing regional control were radiation therapy volume, primary tumor site, node fixation, and node location (upper and lower neck). Significant factors influencing distant control were N-stage, number of nodes, and number of involved lymphatic chains.

Conjunctival intraepithelial and invasive squamous cell carcinomas treated with strontium-90

Twenty-seven patients with malignant epithelial tumors of the conjunctiva were treated between 1967 and 1987. Histological diagnosis was intraepithelial epithelioma in 15 cases (56%) and squamous cell carcinoma in 12 (44%). All patients were treated with a strontium-90 source on cup-shaped applicators of different sizes according to the extension of the tumor. Surface dose ranged from 60 Gy in a single treatment to 140 Gy in 7 fractions, depending on the thickness of the lesion. Fifteen patients were previously untreated, 7 were irradiated after some type of surgical treatment and 5 were treated for recurrence after multiple surgical excisions. Follow-up period ranged from 2 to 15 years. No patient died of his tumor. There were four local recurrences, three of them in patients with intraepithelial carcinoma. Two of the recurrences were salvaged with a new beta-ray treatment and the other two with enucleation. Since 1981, standard policy was to irradiate the entire conjunctiva in patients with diagnosis of intraepithelial epithelioma. Five patients developed cataracts. Considering the high primary control rate and minimal morbidity, strontium irradiation should be considered as a first-choice treatment for conjunctival tumors.

[Treatment and prevention of lymph node metastasis of carcinomas of the oral cavity]

From 1964-1977, 242 previously untreated patients with a oral cavity carcinoma were treated in the Service of Radiotherapy in the Clínica Puerta de Hierro of Madrid. The actuarial survival at five years was 52,5% (26 T1, 96 T2, 120 T3). The presence of nodes in the moment of treatment was of great prognostic value. And so the actuarial survival at five years of the N(+) was 31% vs 64% in the No (p less than or equal to 005). Of 161 patients without adenopathies (No), 73 patients were treated with prophylactic irradiation of the neck, and 88 patients were kept under observation without any cervical treatment; ganglionary relapses appeared in the 5,5% of the first group vs 26% in the patients who had no cervical treatment at all (p less than or equal to 001), wich reaffirms the value of prophylactic or elective radiotherapy.