Alkaline Phosphatases in the Complex Chronic Kidney Disease-Mineral and Bone Disorders.

Alkaline phosphatases (APs) remove the phosphate (dephosphorylation) needed in multiple metabolic processes (from many molecules such as proteins, nucleotides, or pyrophosphate). Therefore, APs are important for bone mineralization but paradoxically they can also be deleterious for other processes, such as vascular calcification and the increasingly known cross-talk between bone and vessels. A proper balance between beneficial and harmful activities is further complicated in the context of chronic kidney disease (CKD). In this narrative review, we will briefly update the complexity of the enzyme, including its different isoforms such as the bone-specific alkaline phosphatase or the most recently discovered B1x. We will also analyze the correlations and potential discrepancies with parathyroid hormone and bone turnover and, most importantly, the valuable recent associations of AP's with cardiovascular disease and/or vascular calcification, and survival. Finally, a basic knowledge of the synthetic and degradation pathways of APs promises to open new therapeutic strategies for the treatment of the CKD-Mineral and Bone Disorder (CKD-MBD) in the near future, as well as for other processes such as sepsis, acute kidney injury, inflammation, endothelial dysfunction, metabolic syndrome or, in diabetes, cardiovascular complications. However, no studies have been done using APs as a primary therapeutic target for clinical outcomes, and therefore, AP's levels cannot yet be used alone as an isolated primary target in the treatment of CKD-MBD. Nonetheless, its diagnostic and prognostic potential should be underlined.

Pathophysiology of bone disease in chronic kidney disease: from basics to renal osteodystrophy and osteoporosis.

Chronic kidney disease (CKD) is a highly prevalent disease that has become a public health problem. Progression of CKD is associated with serious complications, including the systemic CKD-mineral and bone disorder (CKD-MBD). Laboratory, bone and vascular abnormalities define this condition, and all have been independently related to cardiovascular disease and high mortality rates. The "old" cross-talk between kidney and bone (classically known as "renal osteodystrophies") has been recently expanded to the cardiovascular system, emphasizing the importance of the bone component of CKD-MBD. Moreover, a recently recognized higher susceptibility of patients with CKD to falls and bone fractures led to important paradigm changes in the new CKD-MBD guidelines. Evaluation of bone mineral density and the diagnosis of "osteoporosis" emerges in nephrology as a new possibility "if results will impact clinical decisions". Obviously, it is still reasonable to perform a bone biopsy if knowledge of the type of renal osteodystrophy will be clinically useful (low versus high turnover-bone disease). However, it is now considered that the inability to perform a bone biopsy may not justify withholding antiresorptive therapies to patients with high risk of fracture. This view adds to the effects of parathyroid hormone in CKD patients and the classical treatment of secondary hyperparathyroidism. The availability of new antiosteoporotic treatments bring the opportunity to come back to the basics, and the knowledge of new pathophysiological pathways [OPG/RANKL (LGR4); Wnt-ß-catenin pathway], also affected in CKD, offers great opportunities to further unravel the complex physiopathology of CKD-MBD and to improve outcomes.

Vitamin D and Chronic Kidney Disease Association with Mineral and Bone Disorder: An Appraisal of Tangled Guidelines.

Chronic kidney disease (CKD) is a highly prevalent condition worldwide in which the kidneys lose many abilities, such as the regulation of vitamin D (VD) metabolism. Moreover, people with CKD are at a higher risk of multifactorial VD deficiency, which has been extensively associated with poor outcomes, including bone disease, cardiovascular disease, and higher mortality. Evidence is abundant in terms of the association of negative outcomes with low levels of VD, but recent studies have lowered previous high expectations regarding the beneficial effects of VD supplementation in the general population. Although controversies still exist, the diagnosis and treatment of VD have not been excluded from nephrology guidelines, and much data still supports VD supplementation in CKD patients. In this narrative review, we briefly summarize evolving controversies and useful clinical approaches, underscoring that the adverse effects of VD derivatives must be balanced against the need for effective prevention of progressive and severe secondary hyperparathyroidism. Guidelines vary, but there seems to be general agreement that VD deficiency should be avoided in CKD patients, and it is likely that one should not wait until severe SHPT is present before cautiously starting VD derivatives. Furthermore, it is emphasized that the goal should not be the complete normalization of parathyroid hormone (PTH) levels. New developments may help us to better define optimal VD and PTH at different CKD stages, but large trials are still needed to confirm that VD and precise control of these and other CKD-MBD biomarkers are unequivocally related to improved hard outcomes in this population.

Larvicidal activity of micronized aqueous suspension of calcium hydroxide against Aedes aegypti and Culex quinquefasciatus (Diptera: Culicidae).

In the search of alternatives for the control of mosquitoes of medical importance, we evaluated the larvicidal activity of micronized suspensions of calcium hydroxide [Ca(OH)2] against Aedes aegypti and Culex quinquefasciatus. Tests conducted under laboratory conditions determined a LC50 = 0.027% (LC90 = 0.096%) for A. aegypti and a LC50 = 0.092% (LC90 = 0.2%) for C. quinquefasciatus, at 24 h post-treatment. Considering that the LC50 for the less susceptible species killed 100% of larvae for both species at 48 h post-treatment, we decided to use the diagnostic concentration of 0.1% which eliminated 100% of larvae at 48 h under a simulated field trial. There was a residual effect for up to 84 and 70 days for A. aegypti and C. quinquefasciatus, respectively. Evaluation of Ca(OH)2 on breeding sites showed a larvicidal activity of 100% for up to 56 days. When the micronized Ca(OH)2 was incorporated at concentrations from 0.02% (w/v), a superficial film was formed which killed 100% of the larvae of both species after 24 h of contact, and the activity remains until the film broke apart due to stirring. The fact that Ca(OH)2 is cheap and the people in rural areas of Mexico and other countries know the handling procedures for this compound led us to consider that 0.1% suspensions of Ca(OH)2 could be used for mosquito control in deposits of water placed in human premises both in urban and rural areas.

Clinical Approach to Vascular Calcification in Patients With Non-dialysis Dependent Chronic Kidney Disease: Mineral-Bone Disorder-Related Aspects.

Chronic kidney disease (CKD) is associated with a very high morbimortality, mainly from cardiovascular origin, and CKD is currently considered in the high- or very high risk- cardiovascular risk category. CKD-mineral and bone disorders (CKD-MBDs), including vascular and/or valvular calcifications, are also associated with these poor outcomes. Vascular calcification (VC) is very prevalent (both intimal and medial), even in non-dialysis dependent patients, with a greater severity and more rapid progression. Simple X-ray based-scores such as Adragão's (AS) are useful prognostic tools and AS (even AS based on hand-X-ray only) may be superior to the classic Kauppila's score when evaluating non-dialysis CKD patients. Thus, in this mini-review, we briefly review CKD-MBD-related aspects of VC and its complex pathophysiology including the vast array of contributors and inhibitors. Furthermore, although VC is a surrogate marker and is not yet considered a treatment target, we consider that the presence of VC may be relevant in guiding therapeutic interventions, unless all patients are treated with the mindset of reducing the incidence or progression of VC with the currently available armamentarium. Avoiding phosphate loading, restricting calcium-based phosphate binders and high doses of vitamin D, and avoiding normalizing (within the normal limits for the assay) parathyroid hormone levels seem logical approaches. The availability of new drugs and future studies, including patients in early stages of CKD, may lead to significant improvements not only in patient risk stratification but also in attenuating the accelerated progression of VC in CKD.

Calcimimetics in the chronic kidney disease-mineral and bone disorder.

Mineral and bone disorders (MBD) are both an early and very common complication of chronic kidney disease (CKD). It is now accepted that they represent a significant risk factor, explaining the high cardiovascular morbidity and mortality in CKD patients. During the last decade, we have been witnessing many advances in the nomenclature, classification, pathophysiology, diagnosis, and treatment of CKD and some of its complications, such as CKD-MBD. The identification of the calcium-sensing receptor (CaSR) involvement in the pathogenesis of primary and secondary hyperparathyroidism (SHPT) and the availability of a new class of drugs called calcimimetics are two outstanding examples. Cinacalcet, the only available calcimimetic, has been shown to be a very effective therapeutic tool in CKD-MBD. Many clinical trials with cinacalcet in hemodialysis patients with SHPT have shown a reduction in parathyroid hormone, calcium (Ca), phosphate (P) and Ca x P product levels, allowing far greater success in reaching therapeutic goals as recommended by international guidelines. Additionally, some studies have shown that the use of cinacalcet may improve other aspects of CKD-MBD, reducing the risk of vascular calcification and parathyroidectomy, among others. Prospective studies on dialysis patients, with hard endpoint data, are currently underway. This review summarizes the most significant aspects of calcimimimetics based on both experimental and clinical results, underlining their possibilities not only for the treatment of isolated SHPT but also for other CKD-MBD related conditions.

Derivación aorta torácica descendente bifemoral para salvamento de extremidades inferiores / Descending thoracic aortabifemoral bypass to save lower extremities

Cuando la aorta abdominal no es un sitio con flujo adecuado o es técnicamente inaccesible para derivar el flujo a las extremidades inferiores por representar un alto riesgo secundario a múltiples situaciones complejas, se justifica el recurso de las derivaciones extraanatómicas en pacientes apropiadamente seleccionados con resultados de baja morbilidad y mortalidad, mejor calidad de vida y menores costos en comparación con la amputación de extremidades inferiores.Presentamos el caso de un paciente sometido a derivación aorta torácica descendente bifemoral (DATDB) como una alternativa satisfactoria de manejo diferente a las derivaciones extraanatómicas convencionales utilizadas en nuestro medio, con mayor permeabilidad reportada por tener flujo directo de la aorta y sin incremento de la morbilidad y de la mortalidad.

Iatrogenia vascular en pacientes pediátricos / Iatrogenic pediatric vascular trauma

Las lesiones vasculares en pacientes de edad pediátrica, representan un reto para el cirujano vascular. El objetivo del trabajo es reportar la experiencia del CMN 20 de Noviembre ISSSTE, en el manejo de lesión vascular iatrogénica en pacientes pediátricos, en el periodo comprendido del 28 de julio de 1998 al 1 de julio de 1999. Se operaron 6 pacientes con edades de 4 meses a 11 años; con lesión vascular secundaria a venodisección en dos casos, cateterismo cardiaco dos, cirugía ortopédica, y apendicectomía un caso respectivamente. La recuperación de pulsos periféricos se obtuvo en cuatro pacientes, en un paciente con trombosis distal se realizó amputación supracondílea y un paciente falleció por falla orgánica múltiple. El diagnóstico y tratamiento oportuno es lo que hace la diferencia entre amputación y salvamento de extremidad.

Abordaje retroperitoneal en aneurismas de aorta abdominal / REtroperitoneal approach in abdominal aortic aneurysm

El abordaje retroperitoneal izquierdo para el manejo de aneurismas de aorta abdominal ofrece ventajas técnicas, menor morbimortalidad, y menores costos de hospitalización.Objetivo: Reportar la experiencia del Centro Médico Nacional "20 de Noviembre", ISSSTE, en el manejo de aneurismas de aorta abdominal con abordaje retroperitoneal. Pacientes y métodos: Estudio prospectivo, observacional, comparativo, del 1º de marzo de 1995, al 1º de junio de 2000, se operaron 45 pacientes con diagnóstico de aneurisma de aorta abdominal, 10 pacientes se abordaron por vía retroperitoneal, por tener indicaciones para el mismo y 10 por vía transperitoneal elegidos en forma aleatoria, se aplicó prueba estadística de Mann-Whitney (Wilcoxon), y de Moses. Resultados: No se observaron diferencias en sangrado transoperatorio y número de paquetes globulares transfundidos, tiempo de pinzamiento mayor en el grupo retroperitoneal, no existió diferencia en el tiempo quirúrgico total para los dos grupos (p 0.089), el tiempo de intubación en el grupo retroperitoneal fue de 30 horas, y los del grupo transperitoneal de 53.4 horas (p 0.043); el inicio de vía oral en los pacientes del grupo transperitoneal fue de 4.5 días y para el retroperitoneal de 1.8 días (p 0.002). Las complicaciones en ambos grupos no fueron significativas, el tiempo de estancia en UCI fue menor (p 0.03).Conclusiones: El abordaje RP es el procedimiento de elección en pacientes con indicaciones establecidas ofreciendo menor tiempo de apoyo ventilatorio, inicio temprano de la vía oral y menor tiempo de estancia en la Unidad de Cuidados Intensivos.

Aneurisma de aorta abdominal roto y contenido a cavidad peritoneal / Rupture abdominal aortic aneurysm restrained in peritoneal cavity

El aneurisma de aorta abdominal roto se asocia con un alto índice de mortalidad reportándose entre 15 por ciento hasta 80 por ciento de los casos. Presentamos el caso de una paciente de 80 años de edad con un aneurisma de aorta abdominal roto y contenido a la cavidad peritoneal presentando tres síntomas relevantes a su ingreso a urgencias: tumoración abdominal pulsátil, dolor abdominal súbito e hipotensión, caracterizada por lipotimia y diaforesis profusa, se documenta con radiografía y tomografía computarizada de abdomen, ya que permaneció hemodinámicamente estable en urgencias. El curso postoperatorio fue satisfactorio. Conclusiones: El síndrome de abdomen agudo tiene como diagnóstico diferencial el aneurisma de aorta abdominal roto y por lo tanto, el cirujano general en las unidades de urgencias debe tener el suficiente criterio para poder diferenciar las modalidades clínicas de cómo se presenta esta patología en especial.

Secuencia del subprograma de control prenatal en el segundo nivel de atención en salud Hospital Bertha Calderon, Managua julio-agosto 1989 / Subprogram of prenatal control in the second level of health care in Hospital Bertha Calderon; Managua

Estudio de tipo descriptivo e corte transversal y prospectivo, sobre la secuencia del control prenatal (CPN) en el segundo nivel de atención, Hospital Bertha Calderon (HBC), julio-agosto 1989. La muestra se selccionó al azar 100 pacientes atendidas en sala de Alto Riesgo Obstétrico (ARO) y puerperico. Se encontró que el 82% de las pacientes asistió CPN en edades 21-35 años, y hubo un 100% de asistencia CPN entre técnicas y profesionales y un 78% las amas de casa. También el 78% expresó haber recibido buena atención en el nivel primario. Unicamente al 16% de las pacientes les fue solicitada la tarjeta de CPn en otra sala, de ellas el 50% fueron requeridas en la sala de labor y parto el 38% en la sala de ARO. El 90% de las pacientes presentaron dos o más factores de riesgo y el 35% 4 ó más fectores; sin embargo al 35% del total se le solicitó la tarjeta de CPN. Recomienda el no rechazo de la paciente que acude a CPN por no corresponder su domicilio con el centro de salud, así como mejorar la educación popular del CPN a travéz de los medios de difusión y sinsibilizar personal medico del HBC sobre la importancia de la secuencia del CPN en el abordaje incial de la paciente y la identificación de los factores de ARO; a la vez orientar que las tarjetas del CPN sean solicitadas la 100% de las pacientes de consulta obstétrica, las cuales deberan ser anexadas y comentadas en el expediente