Evaluation of sulfate rhizofiltration by Carpobrotus chilensis for treating mining waters.

Chile, the world's leading copper producer, generates significant volumes of mining waters, some of which cannot be recirculated into the production process. These mining waters are characterized by elevated sulfate (SO42-) concentrations, requiring sustainable management strategies for potential reuse. This study aims to evaluate the rhizofiltration technique using Carpobrotus chilensis for treating mining waters with a high SO42- concentration. Initially, the mining waters exhibited a pH of 7.97 ± 0.16 and a SO42- concentration of 2,743 ± 137 mg L-1, while the control water had a pH of 7.88 ± 0.08 and a SO42- concentration of 775 ± 19.0 mg L-1. The plants were hydroponically cultivated in 40 L containers with mining waters and drinking water as a control. Over an 8-week period, the pH of the mining water decreased to 3.12 ± 0.01, and the SO42- concentration declined to 2,200 ± 110 mg L-1. Notably, the fresh weight of roots was significantly higher in plants grown in mining water (22.2 ± 6.66 g) compared to those in the control treatment (14.3 ± 4.28 g). However, an undesirable increase in the acidity was observed in the mining waters after rhizofiltration, which was attributed to hydrogen sulfate (HSO4-) and/or root exudates. Despite the unexpected increase in acidity, C. chilensis effectively reduced the concentration of SO42- in mining waters by 20%. Additionally, the C. chilensis roots accumulated 4.84 ± 1.40% of sulfur (S), a level comparable to thiophore plants. This study provides evidence that this non-aquatic plant can be used in sulfate rhizofiltration.

Caprobrotus chilensis is a good candidate for sulfate rhizolfiltration in mining waters.The accumulation of sulfur by the roots of Carpobrotus chilensis reached 4.84%Mining waters with a high concentration of sulfates require control of the redox potential.

Self-Sensing of Damage Progression in Unidirectional Multiscale Hierarchical Composites Subjected to Cyclic Tensile Loading.

The electrical sensitivity of glass fiber/multiwall carbon nanotube/vinyl ester hierarchical composites containing a tailored electrically-percolated network to self-sense accumulation of structural damage when subjected to cyclic tensile loading-unloading is investigated. The hierarchical composites were designed to contain two architectures differentiated by the location of the multiwall carbon nanotubes (MWCNTs), viz. MWCNTs deposited on the fibers and MWCNTs dispersed within the matrix. The changes in electrical resistance of the hierarchical composites are associated to their structural damage and correlated to acoustic emissions. The results show that such tailored hierarchical composites are able to self-sense damage onset and accumulation upon tensile loading-unloading cycles by means of their electrical response, and that the electrical response depends on the MWCNT location.

Phytostabilization of arsenic in soils with plants of the genus Atriplex established in situ in the Atacama Desert.

In the ChiuChiu village (Atacama Desert, Chile), there is a high concentration of arsenic (As) in the soil due to natural causes related to the presence of volcanoes and geothermal activity. To compare the levels of As and the growth parameters among plants of the same genus, three species of plants were established in situ: Atriplex atacamensis (native of Chile), Atriplex halimus, and Atriplex nummularia. These soils have an As concentration of 131.2 ± 10.4 mg kg(-1), a pH of 8.6 ± 0.1, and an electrical conductivity of 7.06 ± 2.37 dS m(-1). Cuttings of Atriplex were transplanted and maintained for 5 months with periodic irrigation and without the addition of fertilizers. The sequential extraction of As indicated that the metalloid in these soils has a high bioavailability (38 %), which is attributed to the alkaline pH, low organic matter and Fe oxide content, and sandy texture. At day 90 of the assay, the As concentrations in the leaves of A. halimus (4.53 ± 1.14 mg kg(-1)) and A. nummularia (3.85 ± 0.64 mg kg(-1)) were significantly higher than that in A. atacamensis (2.46 ± 1.82 mg kg(-1)). However, the three species accumulated higher levels of As in their roots, indicating a phytostabilization capacity. At the end of the assay, A. halimus and A. nummularia generated 30 % more biomass than A. atacamensis without significant differences in the As levels in the leaves. Despite the difficult conditions in these soils, the establishment of plants of the genus Atriplex is a recommended strategy to generate a vegetative cover that prevents the metalloid from spreading in this arid area through the soil or by wind.

Cloning, expression and decoding of the cold adaptation of a new widely represented thermolabile subtilisin-like protease.

AIMS: Cloning, expression and characterization of a new cold-adapted protease with potential biotechnological application, isolated from Antarctic bacteria. METHOD AND RESULTS: A subtilisin-like gene was isolated from several Antarctic bacterial genus using CODPEHOP-designed primers and a genome walking method. This gene encodes a precursor protein, which undergoes an autocatalytic cleavage resulting in a 34.6 kDa active cold-adapted protease with a maximum activity at 25-35°C and optimum pH of 8.0-9.0. It showed a higher catalytic efficiency at lower temperatures compared to its mesophilic counterpart. Heat-induced inactivation resulted in a very low melting point. Local packing analysis using the homology model indicated Ala284 as an important cold-adaptation determinant, which was corroborated by the site-directed mutagenesis. CONCLUSIONS: A new thermolabile subtilisin-like protease has been successfully cloned and analysed, and an important hot spot in the evolution of the cold adaptation and substrate specificity of this enzyme was identified and tested. SIGNIFICANCE AND IMPACT OF THE STUDY: This work reports a new cold-adapted protease with a vast representation amongst Antarctic genus, suggesting therefore its evolutionary success in this cold environment. Likewise, important sites for genetic potentiation have been identified, which are extrapolated to other enzymes of the same kind.

Degradation of biogenic amines by vineyard ecosystem fungi. Potential use in winemaking.

AIMS: To evaluate the ability of grapevine ecosystem fungi to degrade histamine, tyramine and putrescine in synthetic medium and in wines. METHODS AND RESULTS: Grapevine and vineyard soil fungi were isolated from four locations of Spain and were subsequently identified by PCR. A total of 44 fungi were evaluated for in vitro amine degradation in a microfermentation system. Amine degradation by fungi was assayed by reversed-phase (RP)-HPLC. All fungi were able to degrade at least two different primary amines. Species of Pencillium citrinum, Alternaria sp., Phoma sp., Ulocladium chartarum and Epicoccum nigrum were found to exhibit the highest capacity for amine degradation. In a second experiment, cell-free supernatants of P. citrinum CIAL-274,760 (CECT 20782) grown in yeast carbon base with histamine, tyramine or putrescine, were tested for their ability to degrade amines in three different wines (red, white and synthetic). The highest levels of biogenic amine degradation were obtained with histamine-induced enzymatic extract. CONCLUSION: The study highlighted the ability of grapevine ecosystem fungi to degrade biogenic amines and their potential application for biogenic amines removal in wine. SIGNIFICANCE AND IMPACT OF STUDY: The fungi extracts described in this study may be useful in winemaking to reduce the biogenic amines content of wines, thereby preventing the possible adverse effects on health in sensitive individuals and the trade and export of wine.

Morphological and Mechanical Properties of Electrospun Polycaprolactone Scaffolds: Effect of Applied Voltage.

The aim of this work is to investigate the effect of the applied voltage on the morphological and mechanical properties of electrospun polycaprolactone (PCL) scaffolds for potential use in tissue engineering. The morphology of the scaffolds was characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), and the BET techniques for measuring the surface area and pore volume. Stress-strain curves from tensile tests were obtained for estimating the mechanical properties. Additional studies for detecting changes in the chemical structure of the electrospun PCL scaffolds by Fourier transform infrared were performed, while contact angle and X-ray diffraction analysis were realized for determining the wettability and crystallinity, respectively. The SEM, AFM and BET results demonstrate that the electrospun PCL fibers exhibit morphological changes with the applied voltage. By increasing the applied voltage (10 to 25 kV) a significate influence was observed on the fiber diameter, surface roughness, and pore volume. In addition, tensile strength, elongation, and elastic modulus increase with the applied voltage, the crystalline structure of the fibers remains constant, and the surface area and wetting of the scaffolds diminish. The morphological and mechanical properties show a clear correlation with the applied voltage and can be of great relevance for tissue engineering.

Identification by molecular techniques of halophilic bacteria producing important enzymes from pristine area in Campeche, Mexico.

Isla Arena is located in the coordinate 20° 70´ N - 90° 45´ W, from Campeche, Mexico. In these estuaries, the ocean mixes with fresh water, and ecosystems are concentrated where petenes and pink flamingos proliferate. Crustaceans and mollusks abound in the sea. Despite its enormous marine wealth, there are no studies carried out on which halophilic microorganisms are present in these waters. In this work, the diversity and structure of the microbial community was investigated through a metagenomics approach and corroborated for sequencing of 16S rRNA genes. It was found that the phylum Fimicutes predominates with more than 50%, in almost the same proportion of the class Bacilli and with almost 41% of relative abundance of the order Bacillales. The sequencing results showed that one of the samples presented a high percentage of similarity (99.75%) using the Nucleotide BLAST program with a peculiar microorganism: Bacillus subtilis. This microorganism is one of the best characterized bacteria among the gram-positive ones. Our results demonstrate that B. subtilis can be an efficient source of proteases, lipases and cellulases, from halophilic microbial communities located in poorly explored areas.

Damage Evolution and Fracture Events Sequence Analysis of Core-Shell Nanoparticle Modified Bone Cements by Acoustic Emission Technique.

In this research, damage in bone cements that were prepared with core-shell nanoparticles was monitored during four-point bending tests through an analysis of acoustic emission (AE) signals. The core-shell structure consisted of poly(butyl acrylate) (PBA) as rubbery core and methyl methacrylate/styrene copolymer (P(MMA-co-St)) as a glassy shell. Furthermore, different core-shell ratios 20/80, 30/70, 40/60, and 50/50 were prepared and incorporated into the solid phase of the bone cement formulation at 5, 10, and 15 wt %, respectively. The incorporation of a rubbery phase into the bone cement formulation decreased the bending strength and bending modulus. The AE technique revealed that the nanoparticles play an important role on the fracture mechanism of the bone cement, since a higher amount of AE signals (higher amplitude and energy) were obtained from bone cements that were prepared with the nanoparticles in comparison with those without nanoparticles (the reference bone cement). The SEM examination of the fracture surfaces revealed that all of the bone cement formulations exhibited stress whitening, which arises from the development of crazes before the crack propagation. Finally, the use of the AE technique and the fracture surface analysis by SEM enabled insight into the fracture mechanisms that are presented during four-point bending test of the bone cement containing nanoparticles.

Identification by molecular techniques of halophilic bacteria producing important enzymes from pristine area in Campeche, Mexico

Abstract Isla Arena is located in the coordinate 20° 70´ N - 90° 45´ W, from Campeche, Mexico. In these estuaries, the ocean mixes with fresh water, and ecosystems are concentrated where petenes and pink flamingos proliferate. Crustaceans and mollusks abound in the sea. Despite its enormous marine wealth, there are no studies carried out on which halophilic microorganisms are present in these waters. In this work, the diversity and structure of the microbial community was investigated through a metagenomics approach and corroborated for sequencing of 16S rRNA genes. It was found that the phylum Fimicutes predominates with more than 50%, in almost the same proportion of the class Bacilli and with almost 41% of relative abundance of the order Bacillales. The sequencing results showed that one of the samples presented a high percentage of similarity (99.75%) using the Nucleotide BLAST program with a peculiar microorganism: Bacillus subtilis. This microorganism is one of the best characterized bacteria among the gram-positive ones. Our results demonstrate that B. subtilis can be an efficient source of proteases, lipases and cellulases, from halophilic microbial communities located in poorly explored areas.

Resumo Isla Arena está localizada na coordenada 20°70N - 90°45W, de Campeche, México. Nesses estuários, o oceano se mistura com a água doce e os ecossistemas se concentram onde proliferam petenos e flamingos rosa. Crustáceos e moluscos abundam no mar. Apesar de sua enorme riqueza marinha, não há estudos realizados sobre a presença de microrganismos halofílicos nessas águas. Neste trabalho, a diversidade e estrutura da comunidade microbiana foram investigadas através de uma abordagem metagenômica e corroboradas para o sequenciamento de genes 16S rRNA. Verificou-se que o filo Fimicutes predomina com mais de 50%, quase na mesma proporção da classe Bacilli e com quase 41% de abundância relativa da ordem Bacillales. Os resultados do sequenciamento mostraram que uma das amostras apresentou alto percentual de similaridade (99,75%) pelo programa Nucleotide BLAST com um microrganismo peculiar: Bacillus subtilis. Nossos resultados demonstram que B. subtilis pode ser uma fonte eficiente de proteases, lipases e celulases, provenientes de comunidades microbianas halofílicas localizadas em áreas pouco exploradas.

Identification by molecular techniques of halophilic bacteria producing important enzymes from pristine area in Campeche, Mexico / Identificação por técnicas moleculares de bactérias halofílicas que produzem enzimas importantes em área intocada de Campeche, México

Abstract Isla Arena is located in the coordinate 20° 70´ N - 90° 45´ W, from Campeche, Mexico. In these estuaries, the ocean mixes with fresh water, and ecosystems are concentrated where petenes and pink flamingos proliferate. Crustaceans and mollusks abound in the sea. Despite its enormous marine wealth, there are no studies carried out on which halophilic microorganisms are present in these waters. In this work, the diversity and structure of the microbial community was investigated through a metagenomics approach and corroborated for sequencing of 16S rRNA genes. It was found that the phylum Fimicutes predominates with more than 50%, in almost the same proportion of the class Bacilli and with almost 41% of relative abundance of the order Bacillales. The sequencing results showed that one of the samples presented a high percentage of similarity (99.75%) using the Nucleotide BLAST program with a peculiar microorganism: Bacillus subtilis. This microorganism is one of the best characterized bacteria among the gram-positive ones. Our results demonstrate that B. subtilis can be an efficient source of proteases, lipases and cellulases, from halophilic microbial communities located in poorly explored areas.

Resumo Isla Arena está localizada na coordenada 20°70'N - 90°45'W, de Campeche, México. Nesses estuários, o oceano se mistura com a água doce e os ecossistemas se concentram onde proliferam petenos e flamingos rosa. Crustáceos e moluscos abundam no mar. Apesar de sua enorme riqueza marinha, não há estudos realizados sobre a presença de microrganismos halofílicos nessas águas. Neste trabalho, a diversidade e estrutura da comunidade microbiana foram investigadas através de uma abordagem metagenômica e corroboradas para o sequenciamento de genes 16S rRNA. Verificou-se que o filo Fimicutes predomina com mais de 50%, quase na mesma proporção da classe Bacilli e com quase 41% de abundância relativa da ordem Bacillales. Os resultados do sequenciamento mostraram que uma das amostras apresentou alto percentual de similaridade (99,75%) pelo programa Nucleotide BLAST com um microrganismo peculiar: Bacillus subtilis. Nossos resultados demonstram que B. subtilis pode ser uma fonte eficiente de proteases, lipases e celulases, provenientes de comunidades microbianas halofílicas localizadas em áreas pouco exploradas.

Identification by molecular techniques of halophilic bacteria producing important enzymes from pristine area in Campeche, Mexico / Identificação por técnicas moleculares de bactérias halofílicas que produzem enzimas importantes em área intocada de Campeche, México

Isla Arena is located in the coordinate 20° 70´ N - 90° 45´ W, from Campeche, Mexico. In these estuaries, the ocean mixes with fresh water, and ecosystems are concentrated where petenes and pink flamingos proliferate. Crustaceans and mollusks abound in the sea. Despite its enormous marine wealth, there are no studies carried out on which halophilic microorganisms are present in these waters. In this work, the diversity and structure of the microbial community was investigated through a metagenomics approach and corroborated for sequencing of 16S rRNA genes. It was found that the phylum Fimicutes predominates with more than 50%, in almost the same proportion of the class Bacilli and with almost 41% of relative abundance of the order Bacillales. The sequencing results showed that one of the samples presented a high percentage of similarity (99.75%) using the Nucleotide BLAST program with a peculiar microorganism: Bacillus subtilis. This microorganism is one of the best characterized bacteria among the gram-positive ones. Our results demonstrate that B. subtilis can be an efficient source of proteases, lipases and cellulases, from halophilic microbial communities located in poorly explored areas.

Isla Arena está localizada na coordenada 20°70’N - 90°45’W, de Campeche, México. Nesses estuários, o oceano se mistura com a água doce e os ecossistemas se concentram onde proliferam petenos e flamingos rosa. Crustáceos e moluscos abundam no mar. Apesar de sua enorme riqueza marinha, não há estudos realizados sobre a presença de microrganismos halofílicos nessas águas. Neste trabalho, a diversidade e estrutura da comunidade microbiana foram investigadas através de uma abordagem metagenômica e corroboradas para o sequenciamento de genes 16S rRNA. Verificou-se que o filo Fimicutes predomina com mais de 50%, quase na mesma proporção da classe Bacilli e com quase 41% de abundância relativa da ordem Bacillales. Os resultados do sequenciamento mostraram que uma das amostras apresentou alto percentual de similaridade (99,75%) pelo programa Nucleotide BLAST com um microrganismo peculiar: Bacillus subtilis. Nossos resultados demonstram que B. subtilis pode ser uma fonte eficiente de proteases, lipases e celulases, provenientes de comunidades microbianas halofílicas localizadas em áreas pouco exploradas.

Prediction of retention time of cutinases tagged with hydrophobic peptides in hydrophobic interaction chromatography.

Hydrophobic interaction chromatography (HIC) is an important technique for protein purification, which exploits the separation of proteins based on hydrophobic interactions between the stationary phase ligands and hydrophobic regions on the protein surface. One way of enhancing the purification efficiency by HIC is the addition of short sequences of peptide tags to the target protein by genetic engineering, which could reduce the need for extra and expensive chromatographic steps. In the present work, a methodology for predicting retention times of cutinases tagged with hydrophobic peptides in HIC is presented. Cutinase from Fusarium solani pisi fused to tryptophan-proline (WP) tags, namely (WP)2 and (WP)4, and produced in Saccharomyces cerevisiae strains, were used as model proteins. From the simulations, the methodology based on tagged hydrophobic definition proposed by Simeonidis et al. (Phitagged), associated to a quadratic model for predicting dimensionless retention times, showed small differences (RMSE<0.022) between observed and estimated retention times. The difference between observed and calculated retention times being lower than 2.0% (RMSE<0.022) for the two tagged cutinases at three different stationary phases, except for the case of cut_(wp)2 in octyl sepharose-2 M ammonium sulphate. Therefore, we consider that the proposed strategy, based on tagged surface hydrophobicity, allows prediction of acceptable retention times of cutinases tagged with hydrophobic peptides in HIC.

Evaluation of damage progression and mechanical behavior under compression of bone cements containing core-shell nanoparticles by using acoustic emission technique.

In this work, the effect of the incorporation of core-shell particles on the fracture mechanisms of the acrylic bone cements by using acoustic emission (AE) technique during the quasi-static compression mechanical test was investigated. Core-shell particles were composed of a poly(butyl acrylate) (PBA) rubbery core and a methyl methacrylate/styrene copolymer (P(MMA-co-St)) outer glassy shell. Nanoparticles were prepared with different core-shell ratio (20/80, 30/70, 40/60 and 50/50) and were incorporated into the solid phase of bone cement at several percentages (5, 10 and 15 wt%). It was observed that the particles exhibited a spherical morphology averaging ca. 125 nm in diameter, and the dynamic mechanical analysis (DMA) thermograms revealed the desired structuring pattern of phases associated with core-shell structures. A fracture mechanism was proposed taking into account the detected AE signals and the scanning electron microscopy (SEM) micrographs. In this regard, core-shell nanoparticles can act as both additional nucleation sites for microcracks (and crazes) and to hinder the microcrack propagation acting as a barrier to its growth; this behavior was presented by all formulations. Cement samples containing 15 wt% of core-shell nanoparticles, either 40/60 or 50/50, were fractured at 40% deformation. This fact seems related to the coalescence of microcracks after they surround the agglomerates of core-shell nanoparticles to continue growing up. This work also demonstrated the potential of the AE technique to be used as an accurate and reliable detection tool for quasi-static compression test in acrylic bone cements.

Characterization of the two rRNA gene operons present in Thiobacillus ferrooxidans.

The organization of rRNA genes from the autotrophic, acidophilic bacterium Thiobacillus ferrooxidans has been examined. Two rRNA operons were found in this microorganism by means of genomic hybridization studies. Recombinant plasmids, pTR-3 and pTR-1 that carry a portion of 16/23 S rDNA from one operon and the 5'-flanking region of the second operon, respectively, were identified and characterized.

Identification and structural analysis of a ribosomal RNA gene promoter from Thiobacillus ferrooxidans.

The 5'-terminus of a rRNA operon (rrnT2) from Thiobacillus ferrooxidans was characterized. The rRNA promoters from this microorganism were identified by means of a functional assay in Escherichia coli. DNA sequencing of the promoter region, upstream the 16 S rRNA gene, showed the presence of a consensus sequence for bacterial ribosomal promoters. Other features such as a 'discriminator' sequence, antiterminator elements and an upstream hexanucleotide common to several rRNA operons were also found. Two other putative transcription promoters were also identified.

Theoretical and practical uses of elective systemic (half-body) irradiation after 20 years of experimental designs.

This article traces the concept and different uses of systemic (Half-Body) irradiation (HBI) for the last 20 years. It presents both indirect and direct evidence of HBI effectiveness and discusses the various hypothesis that have been advanced to explain its success as a palliative and more recently as an elective therapeutic tool. The article discusses the transition from treating overt to subclinical metastatic disease and recalls the pioneer uses of elective HBI in lung and prostate cancers. Recent uses of elective HBI with a variety of unconventional fractionation schemes are discussed. These include clinical trials (51 patients with lung, esophagus, colorectal, prostate, ovary and endometrial cancers) and animal experiments (1195 C3H mice). An intriguing combination of hyper/hypo fractionated HBI proved to be the less toxic of all the schedules used in animals where mortality data, analyzed by the LQ Model, yielded an alpha/beta ratio of 8.3 Gy, a value generally associated with acutely responding tissue.

Once-a-week irradiation for locally advanced lung cancer.

Twenty-eight patients with very advanced lung cancer were treated with 500 rad once weekly to a total dose of 6000 rad (2050 ret). Twenty-one of the 28 patients (75%) achieved at least a partial local response. There were 9 patients (32%) who achieved a complete response and 12 patients (43%) who achieved a partial response. The responses were 9/11 for squamous cell carcinoma, 5/10 for adenocarcinoma, 5/5 for large cell carcinoma, and 2/2 for small cell carcinoma patients. Treatment was very well tolerated and in fact, no acute radiation related complications were observed during the 10-12 week treatment duration. Radiation induced fibrosis of various degrees has occurred but it has been mostly asymptomatic and similar to what is normally seen using conventional continuous schedules. In this group of very advanced lung cancer patients, failures have mostly resulted from metastatic progression; only one patient progressed locally in the irradiated field without evidence of metastatic disease. A preliminary analysis indicates that this treatment yields results that are similar to those achieved with conventional fractionation regimens and should be explored further.

Radiation therapy for chest recurrences following induction chemotherapy in small cell lung cancer.

Once small cell lung cancer fails induction chemotherapy, second line drugs are usually ineffective, accounting for mostly partial responses in the order of 0-20% and a median survival of 6-10 weeks. A review of patients with relapsed small cell lung cancer was carried out at the University of Maryland. Of 51 such patients, 44 received thoracic irradiation at the time of relapse. Excluding 8 patients who received insufficient treatment, the series consists of 36 patients (27 with limited and 9 with extensive disease) and represents the largest experience with relapsed small cell lung cancer subjected to radiation alone. Total radiation doses were 60 Gy in 11, 45-55 Gy in 14, and 38-42 Gy in the remaining 11 patients. No second line chemotherapy was given simultaneously with radiation at time of relapse and it was only given subsequently during the course of the disease to four patients. Responses to radiation were seen in 28 (77%) with 9 (25%) complete and 19 (52%) partial. The median survival was 16-40 weeks varying with disease extent, response, and total dose. Subsequent failures occurred in chest (34%) and distant sites (66%). A dose-response curve was attempted; the higher doses achieved as much as 75% local control. A poor response to induction chemotherapy did not predict a poor radiation response at time of relapse. Nearly 2/3 of patients who had not responded to induction chemotherapy responded to radiation at the time of relapse. The post-recurrence survival after radiation therapy was as long as or longer than the recurrence-free interval after induction chemotherapy, and this clearly demonstrates the value of radiation in achieving excellent palliation and good quality of life in these patients. Thoracic irradiation is recommended as a therapeutic alternative for locally recurrent small cell lung cancer after induction chemotherapy.

Carcinoma of the floor of the mouth: a 20-year experience.

From 1955 to 1975, 116 patients with squamous cell carcinoma of the floor of the mouth were primarily treated by irradiation in the Department of Radiation Oncology, University of Maryland at Baltimore. Of these, 93 evaluable patients yielded loco-regional control rates of 83, 85, 42 and 21% for Stages I-IV, respectively. A palisading technique of radium needle implants was used, either alone or combined with external beam therapy, for early tumors (Stages I-II). Similar control rates were achieved by these two techniques: 13/14 for interstitial irradiation alone and 16/24 for combined interstitial and external irradiation. In selected early cases (Stages I-II), errors in staging were minimized by the systematic use of a needle biopsy of the submaxillary triangle for suspicious submaxillary swellings. Patients with early lesions and truly negative nodes (N0) only received irradiation to the primary tumor bed. No subsequent nodal neck failures have occurred in 13 of such patients. The overall complication rate for the entire series was 17% with only 8 patients requiring surgery. No differences in complication rates were found among the treatment modalities employed. The distribution of lymph nodal involvement by anatomical level, correlation of histological differentiation or tumor aggressiveness at presentation, the dosimetric analysis of the palisading interstitial technique, the spread and failure patterns and other observations are discussed.

Once-a-week vs conventional daily radiation treatment for lung cancer: final report.

This is the final report of a prospective randomized clinical trial which began in 1982 and explored once-a-week hypofractionation in lung cancer patients with unresectable, non-metastatic, measurable, loco-regionally advanced disease. Stratification to this protocol has been done by histology, stage, and performance status categories. Patients with ipsilateral supraclavicular and/or brain metastases as the only evidence of distant spread, have been included in the study, but were stratified and analyzed separately. The two protocol arms were: (I) Conventional daily radiation [5 x W]-5 daily fractions of 2 Gy each to a total dose of 60 Gy in 6 weeks, protecting the spinal (SC) at 45 Gy and (II) Once-a-week radiation [1 x W]-one weekly fraction of 5 Gy each to a total tumor dose of 60 Gy in 12 weeks protecting the SC at 30 Gy. A total of 150 patients have been entered. Of these, 30 pts. are inevaluable, but the reasons of non-compliance, progression of disease or death due to intercurrent disease were of equal incidence in both groups. Of the 120 evaluable patients, 63 were treated 5 x W and 57 with 1 x W therapy. Complete tumor responses are similar in both arms with 1 x W pts demonstrating a numerical advantage (26% vs 17%). The average follow-up of the entire series is 3 yrs with a range of 12-66 months. Survival data is comparable in both groups with the 12 and 24 month actuarial survival of 49% and 23% for the 5 x W arm and 59% and 29% for the 1 x W arm. 1 x W patients continue to show a better tolerance than 5 x W pts. There are sufficient long-term survivors in both arms to assess chronic toxicity. The number of patients alive at 12, 18, and 24 months were 25, 11, and 5 for the 5 x W arm and 29, 16, and 7 for the 1 x W arm. No significant differences in late reactions have been noted. The longest surviving patient in the 1 x W arm is now 48 months after treatment.