A coupled modeling approach to assess the effect of forest policies in water provision: A biophysical evaluation of a drought-prone rural catchment in south-central Chile.

The effect of different forest conservation policies on water provision has been poorly investigated due to a lack of an integrative methodological framework that enables its quantification. We developed a method for assessing the effects of forest conservation policies on water provision for rural inhabitants, based on a land-use model coupled with an eco-hydrological model. We used as a case study the Lumaco catchment, Chile, a territory dominated by native forests (NF) and non-native tree farms, with an extended dry period where nearly 12,600 people of rural communities get drinking water through water trucks. We analyzed three land-use policy scenarios: i) a baseline scenario based on historical land-cover maps; ii) a NF Recovery and Protection (NFRP) scenario, based on an earlier implementation of the first NF Recovery and Forestry Development bill; and iii) a Pristine (PR) scenario, based on potential vegetation belts; the latter two based on Dyna CLUE, and simulated between 1990 and 2015. Impacts on water provision from each scenario were computed with SWAT. The NFRP scenario resulted in an increase of 6974 ha of NF regarding the baseline situation, and the PR scenario showed an increase of 26,939 ha of NF. Despite large differences in NF areas, slight increases in inflows (Q) were found between the NFRP and the PR scenarios, with relative differences with respect to the baseline of 0.3% and 2.5% for NFRP and PR, respectively. Notwithstanding, these small differences in the NFRP scenario, they become larger if we analyze the cumulative values during the dry season only (December, January, and February), where they reach 1.1% in a normal year and 3.1% in a dry year. Flows increases were transformed into water truck costs resulting in up to 441,876 USD (monthly) of fiscal spending that could be avoided during a dry period.

Advantages of non-cryopreserved autologous hematopoietic stem cell transplantation against a cryopreserved strategy.

Autologous stem cell transplantation (auto-HSCT) is an effective treatment strategy for hematological malignancies. The standard mode of handling hematopoietic progenitors for the autologous procedure (CRYO) consists on its collection and freezing with dimethyl sulfoxide (DMSO) and its subsequent thawing and re-infusion. This process is toxic and expensive. Non-cryopreserved (non-CRYO) is a less expensive mode of auto-HSCT. We designed a comparative study between both strategies performed in two different centers to analyze the short-term complications. In total 111 auto-HSCT were performed from January/2015 to October/2016 (42 non-CRYO and 74 CRYO). There were 74 males and 69 (62%) patients had the underlying diagnosis of multiple myeloma. No differences were seen on the characteristics of the apheresis products and their viability. Engraftment was significantly faster in the non-CRYO group (p = 0.001). Febrile neutropenia and severe mucositis were lower in the non-CRYO group (40% vs 92% p = 0.0001 and 11% vs 64%, p = 0.001, respectively). In addition, length of hospitalization was 5 days shorter in the non-CRYO group (p = 0.0001). Overall responses and transplantation outcomes were similar. Our data demonstrate a clear advantage of the non-CRYO over CRYO auto-HSCT with faster engraftment, lower incidence of febrile neutropenia and shorter hospital stay after the transplantation procedure. These data are especially relevant for centers with high transplant activity or with limited resources.

Apoptosis inhibition of Atlantic salmon (Salmo salar) peritoneal macrophages by Piscirickettsia salmonis.

To improve the understanding of the piscirickettsiosis pathogenesis, the in vivo apoptosis modulation of peritoneal macrophages and lymphocytes was studied in juvenile Salmo salar intraperitoneally injected with Piscirickettsia salmonis. Five fish were sampled at post-exposure days 1, 5, 8 (preclinical), 20 (clinical) and 40 (post-clinical period of the disease), and the leucocytes of their coelomic washings were analysed by flow cytometry (using the JC-1 cationic dye), TUNEL and cytology to detect apoptotic cells. A selective and temporal pattern of apoptosis modulation by P. salmonis infection was observed. Apoptosis in lymphocytes was not affected, whereas it was inhibited in macrophages but only during the preclinical stage of the induced piscirickettsiosis. Hence, it is postulated that P. salmonis inhibits macrophage apoptosis at the beginning of the disease development to survive, multiply and probably be transported inside these phagocytes; once this process is complete, macrophage apoptosis is no longer inhibited, thus facilitating the exit of the bacteria from the infected cells for continuing their life cycle.

[Retrospective study comparing low-dose versus standard dose of bortezomib in patients with multiple myeloma]. / Estudio retrospectivo que compara dosis bajas versus dosis estándar de bortezomib en pacientes con mieloma múltiple.

INTRODUCTION: Bortezomib is a selective inhibitor of the proteosoma that is used in multiple myeloma. In combination with other antineoplastic drugs, it has a well-documented impact in progression-free survival rates and overall survival rates with standard doses (1.3-1.5 mg/m(2)). However, up to 88% of patients on standard doses have unwanted side effects (neutropenia, neuropathy or anemia. Standard dose (1.3 mg/m(2)) is used in almost all patients and low dose (0.7-0.8 mg/m(2)) is reserved for patients with kidney disease and neuropathy. OBJECTIVE: We aim to describe clinical, cytological, and cytometric outcomes, as well as overall survival and side effects of low dose versus standard dose of bortezomib in our institution. METHODS: Retrospective, descriptive study based on data recovered from clinical charts of 48 multiple myeloma patients treated in our hospital between 2011 and 2013. We included data on age, gender, type of multiple myeloma, serum albumin, serum creatinine, beta 2 microglobulin, calcemia, imaging studies, disease stage, pre-and post-therapy bone marrow studies, adverse events and rate of progression. We also recorded events like date of death or of the last medical appointment. RESULTS: Forty-eight multiple myeloma patients were treated with bortezomib-cyclophosphamide-dexamethasone. Twenty-one patients received low dose and 27 patients were treated with the standard dose. No statistical differences between the two groups were found for clinical response (p=0.6), cytological response (p=0.28), flow cytometric response (p= 0.3), rate of adverse effects and overall survival rates. CONCLUSION: This retrospective analysis suggests that lower doses of bortezomib have similar effects in disease control measured by flow cytometry and cytology compared to standard doses in multiple myeloma patients.

INTRODUCCIÓN: El bortezomib es un inhibidor selectivo del proteosoma usado en el tratamiento del mieloma múltiple. Los estudios clínicos han mostrado excelentes tasas de respuesta con dosis estándar (1,3 a 1,5 mg por metro cuadrado de superficie corporal), pero se ha documentado que hasta el 88% de los pacientes presentan efectos secundarios dados por episodios de neutropenia, neuropatía o anemia. OBJETIVOS: Describir la respuesta clínica, citológica y citométrica así como la sobrevida libre de enfermedad y los posibles efectos adversos con dosis bajas y dosis estándar, en nuestra experiencia. MÉTODOS: Estudio retrospectivo y descriptivo a partir de la información recogida en las historias clínicas de 48 pacientes con mieloma múltiple tratados en nuestro hospital en el período 2011 a 2013. Se incluyeron datos sobre: edad, género, tipo de mieloma múltiple, albúmina sérica, creatinina sérica, beta 2 microglobulina, calcemia, estudio radiológico con o sin resonancia magnética, estadio de la enfermedad, estudio medular pre y post tratamiento, eventos adversos y fecha de progresión, muerte o fecha de último seguimiento. Se identificaron pacientes en los que se empleó la dosis estándar de 1,3 mg por metro cuadrado y pacientes que recibieron una dosis más baja: 0,8 mg por metro cuadrado que definieron dos grupos de pacientes, los que recibieron dosis estándar y los recibieron dosis bajas. RESULTADOS: Veintiún pacientes recibieron dosis bajas y 27 dosis estándar. Al inicio del tratamiento ambos grupos resultaron similares respecto a edad, creatinina sérica, presencia de falla renal, albumina sérica, distribución de los tipos de mieloma y estadio de la enfermedad. En el grupo de dosis bajas, 14 pacientes (66%) y en el grupo de dosis estándar 18 pacientes (67%) tuvieron respuesta clínica, citológica y citometrica al bortezomib (p =0,45). Al término de tratamiento el aclaramiento de plasmoblastos y de células plasmáticas en ambos grupos fue similar. En cuanto a efectos adversos, se observó una baja aparición de neuropatía en ambos grupos y la presencia de trombocitopenia, anemia, infecciones virales y neutropenia fue similar en los dos grupos (sin diferencias significativas). En el momento del análisis retrospectivo, veinte pacientes habían recaído y fallecido, nueve en el grupo de dosis bajas y once en el grupo de dosis estándar. El tiempo libre de enfermedad promedio fue de 30 meses en el grupo estándar y 29 meses en el grupo de dosis bajas. CONCLUSIONES: Nuestros datos apoyan la hipótesis de que el tratamiento con dosis más bajas que lo habitual es capaz de lograr una respuesta medular y clínica similar al de la dosis considerada estándar. No se confirma que los efectos adversos puedan ser menores en los pacientes que reciben dosis más bajas.

Evidence of exotoxin secretion of Piscirickettsia salmonis, the causative agent of piscirickettsiosis.

Piscirickettsia salmonis is the aetiological agent of piscirickettsiosis, a disease which affects a variety of teleost species and that is particularly severe in salmonid fish. Bacterial-free supernatants, obtained from cultures of three isolates of Piscirickettsia salmonis, were inoculated in Atlantic salmon, Salmo salar L., and in three continuous cell lines in an effort to determine the presence of secretion of extracellular products (ECPs) by this microorganism. Although steatosis was found in some liver samples, no mortalities or clinical signs occurred in the inoculated fish. Clear cytotoxicity was observed after inoculation in the cell lines CHSE-214 and ASK, derived from salmonid tissues, but not in MDBK, which is of mammalian origin. The degree of cytotoxicity of the ECPs was different among the P. salmonis isolates tested. The isolate that evidenced the highest cytotoxicity in its ECPs exhibited only an intermediate virulence level after challenging fish with bacterial suspensions of the three P. salmonis isolates. Almost complete inhibition of the cytotoxic activity of ECPs was seen after proteinase K treatment, indicating their peptidic nature, and a total preclusion of the cytotoxicity was shown after their incubation at 50 °C for 30 min. Results show that P. salmonis can produce ECPs and at least some of them are thermolabile exotoxins that probably play a role in the pathogenesis of piscirickettsiosis.

Nitric oxide synthase activity in brain tissues from llama fetuses submitted to hypoxemia.

The fetal llama (Lama glama; a species adapted to live in chronic hypoxia in the highlands of the Andes) did not increase cerebral blood flow and reduce the brain oxygen uptake during hypoxemia. Although nitric oxide (NO) is a normal mediator in the regulation of vascular tone and synaptic transmission, NO overproduction by hypoxemia could produce neuronal damage. We hypothesized that nitric oxide synthase (NOS) activity is either maintained or reduced in the central nervous system of the llama fetuses submitted to chronic hypoxemia. Approximately 85% of the Ca(2+)-dependent NOS activity was soluble, at least 12% was associated with the mitochondrial fraction, and less than 5% remains associated with microsomes. To understand the role of NO in chronic hypoxemia, we determined the effect of 24-h hypoxemia on NOS activity in the central nervous system. No changes in activity or the subcellular distribution of NOS activity in brain tissues after hypoxemia were found. We proposed that the lack of changes in NOS activity in the llama under hypoxemia could be a cytoprotective mechanism inherent to the llama, against possible toxic effects of NO.

Estudio comparativo de películas de diferente latitud en radiografía de tórax / Comparative study of the x-ray films of different latitude in chest radiography

Debido a que la radiografía de tórax es una herramienta fundamental para el diagnóstico de enfermedades torácicas, se ha incentivado la realización de múltiples investigaciones tendientes a mejorar la calidad de imagen y así la información que entrega este examen. Siguiendo esta misma línea, este trabajo determina si existen diferencias en el análisis radiográfico del examen de tórax al usar películas de diferente latitud. Para llevar a cabo este estudio. Se incluyó un grupo de 50 personas adultas, a las cuales se les realizó dos radiografías de tórax frontales (póstero-anteriores), una con película de alta latitud y otra con película de latitud de uso convencional. Estas radiografías fueron tomadas y procesadas bajo iguales condiciones técnicas. Para el análisis de las radiografías se elaboró una pauta de evaluación que incluye un conjunto de 10 estructuras anatómicas pertenecientes al tórax. Dichas estructuras fueron evaluadas, en cada placa, por tres médicos radiólogos de similar experiencia en el tema, los cuales asignaron un puntaje de 1 a 3, dependiendo de cómo se observó cada estructura en los dos tipos de película. Una vez obtenidos los resultados finales, en donde las radiografías realizadas con la película de alta latitud fueron mayoritariamente mejor evaluadas que las radiografías tomadas con la película de latitud normal, se concluyó y demostró que las radiografías tomadas con las películas de alta latitud son capaces de mejorar en forma real la calidad de imagen de la radiografía de torax, debido a que entregan mayor cantidad de información

Aeropalinología de Santiago / Aeropalynology of Santiago

Se realizó un estudio aeropalinológico en Santiago (33º21'S-70º38'W), entre los años 1993-1996. Antecedentes clínicos publicados postulan que el polen es uno de los agentes causales importantes de las alergias en esta ciudad. A pesar de ello, hasta ahora no se conocían las concentraciones reales de granos de polen/m3 en la atmósfera a las que están expuestas las personas sensibilizadas. El presente tiene como objetivo conocer el origen del polen atmosférico, las concentraciones de granos de polen/m3, el aporte aeropolínico de las especies nativas y la dinámica aeropolínica de las especies alergogénicas, para establecer un calendario políclinico. Se cuantificó el polen aéreo desde junio 93 a junio 96 utilizando para la retención del polen un captador tipo Hirst. Paralelamente a esto se realizó una recolección de plantas urbanas y de su respectivo polen para hacer colecciones de referencia. Se registró un total de 96 taxa representados aeropolínicamente, los alergogénicos que se encuentran en mayor concentración se representan graficados en concentraciones de granos de polen/m3 porcentajes acumulados y períodos de polinización. Se concluye que el polen aéreo del área estudiada procede principalmente de especies introducidas, siendo la gran mayoría productoras de polen de comprobada alergogenicidad. El aporte políclinico en la atmósfera de la flora nativa es mínimo, no superado el 2,5 por ciento del total. Además, la cantidad del polen alergogénico en el aire está presente durante todo el año, acentuándose en los meses de primavera y verano. Por esta razón la población sensible a las alergias polínicas está expuesta a tener síntomas de polinosis permanentemente. Las taxa más importantes en el registro aéreo son plantanus, acer, poaceae, cupresaceae, fraxinus, quenopodiaceae, plantago y rumex

Ciprofloxacino en exacerbaciones agudas de enfermedad pulmonar obstructiva crónica / Ciprofloxacin in acute exacerbations of chronic obstructive pulmonary disease

Las exacerbaciones agudas de la EPOC son desencadenadas principalmente por infecciones bacterianas. Recientemente se ha revisado la racionalidad para la selección de antibióticos y se ha propuesto el empleo de ciproflaxacino como alternativa terapéutica. El objetivo de este trabajo fue evaluar la eficacia clínica y microbiológica del ciprofloxacino 750 mg (Baycip Bayer) 2 veces al día durante 9 días en pacientes EPOC con exacerbación aguda. Se realizó un estudio prospectivo, longitudinal, abierto no comparativo, multicéntrico en 57 pacientes. Existió cura clínica en 52 (96,3 por ciento) al día 10 y 49 (90,7 por ciento) al día 21. La eficacia microbiológica se midió en los 17 pacientes con cultivo positivo en la visita inicial. Hubo erradicación bacteriológica en 16 pacientes al día 10 y en 14 al día 21. Hubo 15 eventos adversos, 6 con relación posible o probable con la droga. Ciprofloxacino oral puede ser considerado un antibiótico útil en el tratamiento de las exacerbaciones agudas de EPOC

Queratectomía fotorrefractiva en miopía / Photorefractive keratectomy in myopia

La queratectomía con excimer láser (PRK), ha sido utilizada por muchos años en todo el mundo. En Chile fue introducida en 1992: 134 ojos miopes fueron sometidos a PRK entre abril de 1996 y agosto 1997 en nuestro instituto. La corrección refractiva fue exitosa en el 83 por ciento de los ojos. Complicaciones: observamos 9 Haze 8 de ellos (+) y uno de ellos (++), lo que en total representó el 6,7 por ciento de total. Nuestra experiencia con PRK muestra que éste es un procedimiento seguro y efectivo para tratar miopías

[Analgesic response and secondary effects in patients with osteoblastic metastasis, treated with Samarium 153 ethylenediaminotetramethylenephosphate]. / Respuesta analgésica y efectos secundarios en pacientes con metástasis osteoblásticas tratados con Samario-153 etilendiaminotetrametilenfosfato.

BACKGROUND: Samarium153 EDTMP, a beta and gamma emitter, is used in the palliative therapy of painful bone metastases. AIM: To evaluate the analgesic effects and myelotoxicity of Samarium153 EDTMP in patients with prostate, breast and renal carcinoma. PATIENTS AND METHODS: Twenty patients with bone metastases (11 males), aged 65 years old as a mean, received a 1 to 2 mCi/kg intravenous dose of Samarium153 EDTMP, produced in Chile. Patients were followed thereafter during 4 to 40 weeks. Pain was assessed using a visual analogue scale. RESULTS: Pain decreased from a score of 6.4 prior to treatment, to 2.7 at the fourth week of therapy and the effect lasted a mean of 12.5 weeks. Myelotoxicity was observed in 68% of cases (WHO stage I in 21%, stage II in 37%, stage III in 11% and no patients in stage IV). Platelets were the most affected series and neutrophils the least affected. Cell counts returned to normal between the sixth and eighth week. Seventy nine percent of patients decreased their basal analgesic therapy at the sixth week and 88% did so at the eighth week. Forty one percent of these patients discontinued all analgesics. CONCLUSIONS: Samarium153 EDTMP is effective in the treatment of pain in patients with bone metastases and its myelotoxicity is low to moderate. It should be considered as a therapy for this type of pain, with the precaution of performing periodical bood counts.

ATP-diphosphophydrolase activity in rat heart tissue.

Extracellular nucleotides interact with specific receptors on the cell surface and are locally metabolized by ecto-nucleotidases. Biochemical characterization of the ATPase and ADPase activities detected in rat heart sarcolemma, under conditions where mitochondrial ATPase and adenylate kinase were blocked, supports our proposal that both activities correspond to a single enzyme, known as ATP-diphosphohydrolase or apyrase. The physiological function of this enzyme could be dephosphorylation of the nucleotides present in the interstitial heart compartment acting together with 5'-nucleotidase. Both hydrolytic activities have similarities in: sarcolemma localization, bivalent metal ion dependence, optimum pH, effect of several amino acid residue modifiers, competitive inhibition of nucleotide analogs, and broad nucleoside di-and triphosphate specificity. The ATPase activity could not be separated from the ADPase either through isoelectrofocusing or electrophoresis under acid conditions.

Characterization of ATP-diphosphohydrolase from rat mammary gland.

ATP-diphosphohydrolase (or apyrase) hydrolyses nucleoside di- and triphosphates in the presence of millimolar concentration of divalent cations. It is insensitive towards sulfhydryl and aliphatic hydroxyl-selective reagents and to specific inhibitors of ATPases. We present further evidence that ATPase and ADPase activities present in rat mammary gland correspond to apyrase. Two kinetic approaches have been employed, competition plot and chemical modification with group-selective reagents. The M(r) of these activities was determined by 60Co radiation-inactivation. The kinetic approaches employed, competition plot (which discriminate whether competitive reactions occur at the same site) and chemical modification, point to the presence of a single protein which hydrolyses ATP and ADP. The similar M(r) values of ATPase and ADPase activities also support this proposal. ATPase and ADPase activities of mammary gland show a similar sensitivity or insensitivity towards several chemical modifiers. These results suggest that this enzyme is ATP-diphosphohydrolase, also known as apyrase. The results obtained are compared with the ones obtained by us and other authors with the enzyme isolated from other sources.

Biochemical, immunological, and biological characterization of Trypanosoma cruzi populations of the Andean north of Chile.

Twenty-one Trypanosoma cruzi stocks isolated from Triatoma infestans and humans of the Chilean Andean highlands were studied at the genotypic level by schizodeme and molecular karyotype analyses, which allowed a clear distinction of the parasites from those hosts. A phenotypical characterization was performed by proteolytic activity after electrophoretic fractionation without discrimination among the stocks. Metacyclic trypomastigotes obtained in vitro proved to be infective to Swiss mice and the study of immune response and biological behavior was assessed. Of a total of 21 T. cruzi stocks, only 11 proved to be infective in mice due to difficulties in obtaining metacyclic trypomastigotes with the parasite populations isolated from humans. Western blot analysis revealed a complex immune response even in the first days postinfection with each T. cruzi strain studied. Antigenic recognition by each immune serum is characteristic, although several major and common antigens were detected. Lytic antibodies were studied by the in vitro complement-mediated lytic assay using purified metacyclic trypomastigotes as target cells. All the T. cruzi isolates tested induced lytic antibodies in this experimental model. Parasitemias were moderate and characteristic for each T. cruzi strain. Results are compared with metacyclic forms of the infective and pathogenic Tulahuen strain.

Perforación del esófago torácico: dos casos clínicos / Thoracic esophage perforation: 2 clinical cases

La ruptura del esófago, independiente de su etiología o localización, es un evento catastrófico debido al depósito de saliva, flora oral o ácido gástrico en los tejidos del cuello mediastino o pleura. EL diagóstico es difícil y su evolución depende de la localización y del tiempo transcurrido entre el inicio del cuadro y la instauración de la terapia. Se presentan los casos clínicos de dos pacientes aquejados por esta patología. Uno de ellos era un hombre de 44 años portador de SIDA que desarrolló una candidiasis esofágica intratable, una perforación esofágica iatrogénica y mediastinitis. Murió posteriormente en shock séptico. El segundo caso afectó a una mujer de 66 años portadora de asma bronquial, úlcera gástrica y herida del hiato, que presentó una perforación distal, secundaria a la ingesta de un trozo de carne. El esófago se fistulizó hacia la pleura, manifestándose con derrame pleural. Fue tratada exitosamente con una intervención quirúrgica. En esta comunicación se analiza ambos casos y se comenta su diagnóstico y su enfoque terapéutico

Caso clínico: hernia de Morgagni / Clinical case: Morgagni's hernia

La hernia de Morgagni es una patología poco frecuente que habitualmente es un hallazgo radiológico y se caracteriza por dar escasos o nulos síntomas. A la radiografía se presenta como una imagen redondeada, lisa, homoogénea, que ocupa el ángulo cardiofrénico derecho. El saco herniario contiene de preferencia omentun y rara vez vísceras o intestino. Emerge por el foramen de Morgagni que normalmente contiene los vasos mamarios, grasa y tejido conectivo. Se presenta el caso clínico de un paciente de 66 años que ingresa en malas condiciones, con apremio respiratorio, fiebre de 10 días de evolución y radiografía con imagen de condensación basal derecha. Fue tratado con antibióticos con el diagnóstico de neumonía aspirativa. Sin embargo, la persistencia de la imagen radiológica en discordancia con la mejoría clínica del paciente, llevaron a practicar procedimientos diagnósticos adicionales. Finalmente, la tomografía axial computarizada de tórax, reveló la presencia de asas intestinales en la base del hemitórax derecho emergiendo a través del foramen de Morgagni

[Microalbuminuria after unilateral nephrectomy in humans: study of effects of dietary protein]. / Microalbuminuria postnefrectomia unilateral en humanos: estudio del effecto del contenido habitual de proteina de la dieta.

Microalbuminuria may be due to increased glomerular capillary pressure. In turn, this increased pressure may be associated to augmented protein intake or reduction of renal mass. 85 normal subjects who had a unilateral nephrectomy were studied. Creatinine clearance, microalbuminuria and blood pressure were measured. Hyperfiltration was evaluated by comparison of creatinine clearance before and after nephrectomy. Protein intake was evaluated by a nutritional questionnaire. Hyperfiltration was estimated as 38% and microalbuminuria was not different in patients submitted to nephrectomy (9.8 micrograms/min) compared to controls (9.7). Microalbuminuria post nephrectomy was not correlated to level of hyperfiltration, protein intake, age, blood pressure or time after surgery. These results suggest that the remaining kidney is able to double the excretion of albumin with a likely increase in glomerular filtration and intracapillary pressure.