Study of the photoneutron generation caused by a LinAc Beryllium window with a 6 MeV treatment beam.

In most conventional radiation therapy treatments, special attention is payed for neutron contamination when working with energy beams above 8 MeV and generally it is only considered for shielding requirements, not for dose study in patients or employees. The present work is focused on studying the unwanted generated photoneutrons in a Medical Linear Accelerator (LinAc) Varian TrueBeam using a 6 MeV radiation treatment beam. To that, Monte Carlo (MC) simulation code MCNP6.1.1 was used. This version of the code allows the use of unstructured mesh geometries as a novelty, offering more reliable results and higher speed computation. The particularity of the studied LinAc is the presence of a beryllium filter at the treatment head. Since Beryllium causes photonuclear reactions (γ, n) at energies much lower than other LinAc composing materials, this work aims to analyze if this type of units, when using low energy treatment beams (6 MeV), produce neutron pollution and to ensure that this unwanted radiation can be considered negligible.

Antifungal activity of Parastrephia quadrangularis (Meyen) Cabrera extracts against Fusarium verticillioides.

Fungi are cosmopolitan organisms that grow in and adapt to a vast number of substrates and environments, and that can cause diseases in humans and animals, as well as in crops. The vast area and diverse geographical characteristics of Argentina, with the consequent climatic diversity make the country an important source of biological resources suitable for the search of new compounds. The aim of the present study was to describe the antifungal activity of extracts of Parastrephia quadrangularis, a species from northern Argentina, against Fusarium verticillioides M7075. Bio-guided fractionation and MS/MS studies were conducted to elucidate the chemical structure of active compounds. The extracts exhibited a minimum inhibitory concentration among 118·74 and 250 µg ml-1 and the differences between the treatments and the inoculum control was 12·5-16·5 mm, respectively, in colony growth. Moreover, hyphae treated with the extracts stained blue with Evans blue, showed alterations in permeability of plasma membranes. HLPC-MS analysis of active fractions revealed the presence of p-coumaroyloxitremetone, and a derivate structure for another compound is proposed. SIGNIFICANCE AND IMPACT OF THE STUDY: In Argentina, Fusarium verticillioides causes 'ear rot', a disease that produces important yield and nutritional quality losses in the maize producing region. This study suggests that Parastrephia quadrangularis extracts have potential for the growth inhibition against F. verticillioides M7075, and the bioactivity is reported for the first time. The results obtained will provide a starting point for discover new antimicotic candidate in natural products.

Outbreak of ataxia in pigs associated with consumption of piquillín (Condalia microphylla).

The plant piquillín (Condalia microphylla) grows in arid regions of Argentina and is the cause of mal del piquillín in cattle. The salient histologic features of this leukomyelopathy are vacuolation of white matter and axonal degeneration in the spinal cord. The histologic lesions can be experimentally reproduced in cattle and pigs by feeding milled bark of the plant, but naturally occurring piquillín toxicosis has not been reported previously in pigs. The authors report an outbreak of progressive ataxia on an Argentine hog farm, where partially consumed piquillín plants were found in the pens of affected pigs. Histologic lesions included vacuolation of white matter, edema, and mild axonal degeneration in lumbosacral segments of the cord. The diagnosis of mal del piquillín was based on the history, clinical signs, histologic changes, and elimination of other potential causes of leukomyelopathy. No new outbreaks developed after elimination of piquillín from the hog lots. Results of this investigation indicate that C microphylla toxicosis can affect pigs under natural conditions and should be included in the differential diagnosis for porcine ataxia and leukomyelopathy in regions where the plant grows.

Efectos inmediatos del kinesio taping en la flexión lumbar / Immediate effects of Kinesio Taping on trunk flexion

ObjetivosAnalizar si la aplicación del kinesio taping consigue un incremento en la flexión del tronco en comparación con la aplicación de vendas placebo y vendas adhesivas convencionales. Estudiar en qué segmentos se consigue este posible incremento.Material y métodosEstudio experimental a doble ciego. Los treinta y tres sujetos participantes fueron distribuidos aleatoriamente en tres grupos: a) aplicación del kinesio taping; b) aplicación de vendas convencionales, y c) grupo placebo. Se valoró la flexión del tronco de todos los sujetos mediante la prueba sit-and-reach antes y después de la intervención siguiendo un protocolo idéntico. Posteriormente, se analizó el incremento en la flexión del tronco de los sujetos del grupo kinesio taping mediante el software e-Ruler®.ResultadosLa media de incremento de la flexión del tronco de los sujetos del grupo kinesio taping es superior a la de los otros grupos, pero la diferencia no es estadísticamente significativa (análisis de la variancia, p=0,67). Todos los sujetos del grupo kinesio taping incrementan su flexión del tronco, mientras que en los otros dos grupos la proporción es de un 77%; sin embargo, este resultado no alcanza significación estadística (Chi cuadrado p=0,06). Existe correlación entre el incremento conseguido en el grupo kinesio taping y el decremento del ángulo coxofemoral (r=−0,712; p<0,05).ConclusionesNo se ha podido demostrar que la aplicación del kinesio taping incremente la flexión del tronco. La ganancia conseguida se relaciona más con el decremento del ángulo coxofemoral que con una mayor extensibilidad del raquis(AU)

AimsThis study has aimed to analyze whether the application of Kinesio taping increases trunk flexion compared with the application of placebo bandages and conventional adhesive bandages and to study in which segments this possible increase occurs.Materials and methodsExperimental, double-blind study. The 33 subjects were randomly distributed into three groups: Kinesio taping was used in group A, conventional bandages in group B, and placebo bandages in group C. An identical protocol was followed, evaluating trunk flexion in all of the subjects with the set-and-reach test before and after the treatment. The software e-Ruler® was then used to evaluate increase in trunk flexion in the Kinesio taping group.ResultsThe average increase in trunk flexion in the Kinesio taping group was greater than that of the other groups. However, the difference was not statistically significant (ANOVA, p=0.67). Trunk flexion increased in all the subjects in the Kinesio taping group whereas it increased in 77% of the subjects in the other two groups. However, this result is not statistically significant (Chi square p=0.06). A correlation was found between the increase in the Kinesio taping group and the decrease in the coxofemoral angle (r=−0.712; p<0.05).ConclusionsIt could not be demonstrated that the application of Kinesio taping increases trunk flexion. The gain achieved is more closely related to the decrease in the coxofemoral angle than to the greater extensibility of the rachis(AU)

Antimicrobial activity in methanolic extracts of several plant species from northern Argentina.

Thirty-nine native plant species were collected from the provinces of Chaco and Formosa, in northern Argentina, and were screened for antimicrobial activity. The plants were dried and extracted thoroughly with methanol. The dry extracts, dissolved in dimethylsulfoxide, were tested for inhibition of microbial growth via microplate assay with an oxidation-reduction dye. The test organisms were: Escherichia coli, Salmonella typhimurium, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus and Enterococcus faecium. Inhibition of respiratory activities in some of these microbial species was produced by the extracts of Astronium balansae, Geoffroea decorticans, Peltophorum dubium, Geoffroea spinosa, Lantana balansae, Prosopis kuntzei, Prosopis ruscifolia and Bulnesia sarmientoi, with minimal inhibitory concentrations (MIC) ranging from 0.08 to 0.5 mg dry matter/ml. Further in vitro experiments measuring the growth of S. aureus in liquid culture confirmed that all of the above extracts at 2 x MIC were able to inhibit bacterial growth effectively, and that some of them (A. balansae, G. decorticans, P. dubium, G. spinosa, P. kuntzei and B. sarmientoi) were able to reduce the initial number of viable counts by at least one order of magnitude in 10 hours, indicating that these extracts should be investigated further for the possible presence of bactericidal components.

A simple thin-layer chromatographic method for the detection of ergovaline in leaf sheaths of tall fescue (Festuca arundinacea) infected with Neotyphodium coenophialum.

A relatively simple and inexpensive thin-layer chromatographic (TLC) method is described for the detection and semiquantitative measurement of ergovaline in leaf sheaths of tall fescue (Festuca arundinacea). Samples were finely ground and extracted with methanol. The extracts were filtered and the methanol was evaporated. The aqueous residue was extracted with hexane, followed by chloroform at pH 9. The chloroform extract was concentrated and further purified on a preparative silica gel TLC plate, developed with toluene/ethyl acetate/acetonitrile (50:10:40). The ergovaline band was scraped and eluted with methanol. The eluant was concentrated and an aliquot was applied to a silica gel TLC plate. The plate was developed successively with chloroform/acetone/acetic acid (90:10:5) and chloroform/ethanol (9:1). Ergovaline was visualized with p-dimethylaminobenzaldehyde and sulfuric acid. Semiquantitation of ergovaline was achieved by comparison with a known standard of ergotamine, which was shown to have the same Rf as ergovaline in this system. Spike recovery of ergotamine averaged 60%, with a limit of detection of 200 microg/kg of dry tall fescue leaf sheaths. The method was applied to 15 tall fescue samples with varying degrees of fungal infection, and ergovaline was identified in all contaminated samples with endophyte infection above 15%. Thin-layer chromatography may be also applicable for tall fescue seed, where the ergovaline content is usually higher and the amount of interfering pigments is much lower.

Screening of some plants from Northern Argentina for their antimicrobial activity.

AIMS: Screening of antimicrobial activity in 25 plant species from Northern Argentina. METHODS AND RESULTS: Inhibition of microbial growth was measured by a microplate assay with an oxidation-reduction indicator (Alamar Blue). Test organisms were: Escherichia coli, Salmonella typhimurium, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus and Enterococcus faecium. Weak inhibitory activities (MIC=0.5 mg dry matter ml(-1)) were found in methanolic extracts of Rivina humilis, Crateva tapia, Funastrum claucum and Schinopsis balansae. Stronger bacteriostatic power was detected in Vassobia breviflora (MIC=0.25 mg ml(-1) against Staphylococcus aureus, and 0.5 mg ml(-1) against Enterococcus faecium). This activity was purified five-fold by extraction with dichloromethane, and it was found equally effective against susceptible or antibiotic-resistant strains of Staph. aureus. In addition, the purified extract was synergistic with gentamicin, and it was bactericidal at 24 h, with a concentration of 0.25 mg ml(-1). CONCLUSION: There is a significant antimicrobial activity in Vassobia breviflora. SIGNIFICANCE AND IMPACT OF THE STUDY: Further studies will be required to disclose the potential importance of these findings.

Suppression of spore germination and aflatoxin biosynthesis in Aspergillus parasiticus during and after exposure to high levels of phosphine.

Agar cultures of toxigenic Aspergillus parasiticus NRRL 2999 were exposed to phosphine (PH3), in levels ranging from 0 to 2000 ppm (vol/vol). It was found that with PH3 concentrations of 400 ppm or higher the growth of the fungus was totally arrested. When PH3 was vented and the agar plates were exposed to open air, 100% of the initial CFU developed into fully grown colonies after PH3 levels below 300 ppm, but at higher PH3 concentrations only 50% of the colonies developed. The same strain of A. parasiticus was inoculated into high moisture corn under conditions highly favorable for aflatoxin production, and it was exposed to a range of PH3 levels. After exposure to 500 ppm PH3, both fungal growth and aflatoxin synthesis resumed shortly after elimination of the toxic gas, but after exposure to PH3 levels of 1000 ppm and higher, the physical appearance of the contaminated corn was remarkably changed, showing reduced mycelial growth and almost complete absence of green pigmentation. In addition, aflatoxin synthesis was totally absent for the remainder of the experiment (20 days). These results strongly suggest that exposure to PH3 levels of 1000 ppm or higher could bring about persistent metabolic changes in surviving Aspergillus organisms.

Nicardipine as antihypertensive therapy in liver transplant recipients: results of long-term use.

Arterial hypertension is frequent in liver transplant recipients on cyclosporine A (CsA). Nicardipine is a calcium channel blocker (CCB) that has been shown to be efficient in controlling postoperative hypertension. However, its use has been limited in organ recipients because of its reported interaction with CsA metabolism. In this report, we studied the results of the long-term use of nicardipine after liver transplantation. Forty-nine consecutive liver transplant recipients with a follow-up longer than 2 years were studied. Immunosuppressive regimen was based on CsA and prednisone. Patients with immediate postoperative hypertension received intravenous nicardipine, secondarily switched to oral nicardipine (group 1, n = 27). Patients with delayed hypertension (i.e., >2 weeks posttransplant) received other antihypertensive drugs which did not interact with CsA metabolism. These patients and those without hypertension formed group 2 (n = 22). The two groups were similar for age, sex, body weight, and transplantation indications. Interaction of nicardipine with CsA metabolism was confirmed. Whereas cyclosporine blood levels were similar in both groups at any time during the study, the mean cyclosporine daily dose required to achieve such levels was 30% lower in group 1 compared with group 2 (P < .01). This resulted in a significant cost-containment. The use of nicardipine was not associated with an increased incidence of graft rejection or CsA toxicity episodes. The results in liver transplant recipients showed that nicardipine interacts with CsA metabolism, leading to a 30% reduction in CsA dose and does not increase the risk of CsA toxicity or graft rejection. Nicardipine can be used safely for the treatment of arterial hypertension after liver transplantation with a potential cost-containment.

[Limitation of blood transfusions during hepatectomies. Study of 150 consecutive hepatic resections on healthy and pathological livers]. / Limitation des transfusions sanguines au cours des hépatectomies. Etude de 150 résections hépatiques consécutives sur foie sain et pathologique.

OBJECTIVE: Over the last 5 years, a policy to limit blood transfusions has been adopted in patients undergoing liver resection. The aim of this retrospective study was to report the results of 150 liver resections performed during this period. METHODS: There were 63 major (42%) and 87 minor hepatectomies (58%). Resection was performed for malignant lesions in 64% of the patients. Vascular exclusion of the liver was used in large (> or = 10 cm) tumors and those located at the cavohepatic junction. Clamping of the portal triad or selective clamping of the pedicle of the portal lobe was used in peripheral lesions < 10 cm in diameter. Anesthesia was adapted to the type of vascular clamping and blood transfusions were deliberately limited. Red blood cells were transfused to maintain the hematocrit level above 25% in healthy patients and above 30% in patients with risk of coronary artery disease. RESULTS: Ninety three patients (62%) did not receive blood transfusions. Three patients received more than 10 units of packed red blood cells (2%). 48% of patients with major hepatectomies and 72% with minor hepatectomies were not transfused. The rate of non transfused patients was 93% for benign lesions and 44% for malignant lesions. The presence of pathologic changes in non-tumor liver parenchyma did not influence the need for transfusions. Hospital mortality was 3% (5/150). There was no mortality in patients with normal non-tumorous livers, 14% in the presence of cirrhosis, and 12% in the presence of obstructive jaundice or steatosis > 50%. The specific morbidity rate was 7% in patients with normal livers and 54% in patients with abnormal livers. CONCLUSION: This series shows that more than 60% of liver resections can be performed without blood transfusions. These results require an appropriate surgical technique and collaboration between anesthesiologist and surgeon. Thus hepatectomies in normal non-tumorous livers can be performed without mortality. In contrast, the presence of abnormalities of the non-tumorous liver parenchyma remains a major risk factor.

[Value of a powerful initial immunosuppression after liver transplantation. Prospective study of 60 cases]. / Intérêt d'une forte immunosuppression initiale après transplantation hépatique. Etude prospective de 60 cas.

With usual immunosuppression, the incidence of acute rejection after liver transplantation is higher than 60% in most series. The aim of this prospective study was to assess the value of a powerful initial immunosuppression on acute rejection, mortality and morbidity. REGIMEN. Group 1: patients with normal postoperative renal function (serum creatinaemia < 150 mumol/L) received cyclosporine from day 1 to day 15 by continuous i.v. infusion to reach a whole blood level of 400 to 500 ng/mL; after day 15, cyclosporine was reduced. Group 2: in cases of postoperative renal failure (serum creatinine > or = 150 mumol/L), anti-thymocyte globulins were used for 10 days; cyclosporine was introduced after recovery of renal failure at usual doses. In addition, all patients received steroids and azathioprine according to usual regimens. RESULTS. From January 1989 to June 1992, 60 cases were studied in 59 patients: 45 (75%) entered group 1 and 15 (25%) entered group 2. In group 1, there were 11 acute rejection episodes (24%) and one postoperative death at three months (2.3%). In group 2, two early deaths (within 5 days) were excluded from the study of rejection. Among the 13 remaining cases, there were three episodes of acute rejection (23%) and one hospital death at three months. Overall, there were 14 episodes of acute rejection (24%), 12 of which were steroid-responsive (86%), no chronic rejection, a usual rate of infections (57%), one retransplantation (1.7%) and a hospital mortality of 6.8% (4 of 59 cases). One year survival was 78%, with 5 of 7 late deaths due to recurrent cancer. CONCLUSIONS. Our results suggest that, after liver transplantation, a) high initial cyclosporine dose in patients with normal postoperative renal function is associated with reduced incidence and severity of acute rejection without increased mortality and morbidity, b) antithymocyte globulins are an efficient alternative to cyclosporine in patients with postoperative acute renal failure and saves OKT3 for the treatment of steroid-resistant rejection.

Evaluation of Doppler examination for diagnosis of catheter-related deep vein thrombosis.

The accuracy of Doppler examination was evaluated for the diagnosis of catheter-related venous thrombosis in 40 postoperative patients. Deep vein thrombosis was detected by venography in 15 patients and confirmed by the Doppler technique in a double blind study. Only one false-positive and one false-negative result were obtained with the Doppler technique. This technique appears to be valuable for the early diagnosis of catheter-related vein thrombosis, even in asymptomatic patients.

[Value of a fraction of low molecular weight heparin, enoxaparine, in patients at high risk of hemorrhage and thrombosis]. / Intérêt d'une fraction d'héparine de bas poids moléculaire, l'énoxaparine, chez des patients à hauts risques hémorragique et thrombotique.

Treatment of patients with both thromboembolic manifestations and acute bleeding episodes is poorly defined. The use of low molecular weight heparin fractions has been shown to provide prophylactic antithrombotic activity in humans, with the possibility of fewer hemorrhagic complications because of their low anticoagulant activity and weaker action on platelets. An open trial was carried out in 50 patients. 47 of whom had a recent history of thromboembolic accident (34 venous thrombosis, including 13 with pulmonary embolism, 9 systemic arterial episodes, 4 cardiac emboli) and 3 who required prophylaxis. Conventional heparin therapy was contraindicated in all patients: 30 because of major digestive or muscle hemorrhage and 20 with high hemorrhagic risk (neurosurgery, deep thrombocytopenia). Enoxaparine (Laboratoire Pharmuka, Gennevilliers) was administered as 1 mg/kg/24 hours as 2 divided injections with adjustment to maintain an anti-Xa activity of 0.1 to 0.4 IU/ml. Antithrombotic efficacy as function of type of pathology was rated excellent in all patients, while tolerance, evaluated similarly by tests chosen as a function of type of hemorrhage, was good: one patient had moderate bleeding after accidental overdose and 4 patients minor bleeding. Enoxaparine by subcutaneous injection could represent a new therapeutic approach by improving the efficacy/risk ratio in this type of patients.

Post-operative rigidity after fentanyl administration.

A case of thoraco-abdominal rigidity leading to respiratory failure is described in the post-operative period in an elderly patient who received a moderate dose of fentanyl. This was successfully reversed by naloxone. The mechanisms possibly implicated in this accident are discussed.

[Treatment of acute necrotizing pancreatitis with peritoneal lavage. 12 cases]. / Traitement des pancréatites aiguës nécrosantes par lavage péritonéal. 12 observations.

In an intensive care unit 12 consecutive patients with acute necrotizing pancreatitis were treated with peritoneal lavage. All clearly improved: pain was promptly relieved and the symptoms of shock and respiratory failure regressed. None of the patients died during the first 10 days. The five deaths recorded were due to late septic shock consecutive to suppuration of the pancreatic gland. It is concluded that peritoneal lavage helps to tide patients over the critical first days of severe acute pancreatitis.

[Outcome of surgery in 300 cases of hyperthyroidism, including 40 with cardiotoxicity (author's transl)]. / Evolution de 300 hyperthyroïdies operees dont 40 cardiothyreoses.

Of 300 patients who underwent subtotal thyroidectomy, 204 had Graves' disease, 52 solitary toxic goiter and 39 multinodular toxic goiter. Cardiotoxicity was present in 40 cases. Immediate post-operative complications could be avoided by the use of propranolol, neuroleptanalgesia and, in a few very severe cases, hypothermia. Long term results were satisfactory, even after surgery for diffuse hyperthyroidism. Relapses occurred in only 2%, and permanent hypothyroidsm developed within 3 years in only 18% of patients with Graves' disease, this being due to the preservation of 6 grams of thyroid tissue systematically measured by comparative double-weighing. The authors insist on the value of this technique, guess evaluation being unreliable. Cardiotoxicity did not increase post-operative complications, nor the risk of permanent hypothyroidism. The good results obtained should encourage wider surgical indications for the treatment of Graves' disease, solitary toxic goiter or multinodular toxic goiter.

[Acute haemorrhagic pancreatitis. Criteria of letality (author's transl)]. / Pancréatites aiguës nécrosantes. Les facteurs de létalité.

A retrospective study of severity symptoms in a series of 102 patients operated upon for acute haemorrhagic pancreatitis showed that the risk of death was much significantly higher when shock (p less than 0,00001) and renal failure (p less than 0,0001) were present. The association, during the post-operative period, of shock and renal failure with one of the following symptoms: digestive haemorrhage, psychic disorders, pulmonary oedema, post-operative peritonitis and evisceration invariably proved fatal. It is suggested that controlled therapeutic trials should be carried out in patients presenting with these complications.