FERNANDO PERAN - Academia.edu (original) (raw)
Papers by FERNANDO PERAN
American Journal of Surgery, Apr 1, 2007
The objective of the current study was to study different functional and anatomic features of the... more The objective of the current study was to study different functional and anatomic features of the hyperplastic gland and clinical and biochemical characteristics of renal hyperparathyroidism (HPT) patients and their relationship with the scintigraphic detection of parathyroid glands. A retrospective study was performed of 40 patients with chronic renal failure (CRF) who underwent cervical surgery for HPT. Weight, histology, and localization of hyperplastic glands were recorded. Parathyroid cell proliferation was assessed by percentage of S-phase cells. Double-phase scintigraphy with technetium 99m-sestamibi and serum parathyroid intact hormone (PTHi), creatinine, calcium, and phosphate levels were performed. Detection of hyperplastic parathyroid glands by 99mTc-sestamibi scintigraphy was associated with the weight and inferior localization of the glands. The functionality of the glands as reflected in serum PTHi and phosphorus levels was associated with the number of glands detected. Double-phase 99mTc-sestamibi scintigraphy is of limited usefulness in patients with renal HPT. Detection of hyperplastic parathyroid glands in patients with CRF depends on the weight and inferior localization of the glands. Serum PTHi, phosphorus and creatine levels are associated with the number of glands detected by means of 99mTc-sestamibi scintigraphy.
Transplantation Proceedings, 2007
Introduction. In dialysis patients, the parathyroid glands (PTGs) may increase progressively, pro... more Introduction. In dialysis patients, the parathyroid glands (PTGs) may increase progressively, producing abnormal bone metabolism. Changes in PTG volume among patients with hyperplastic PTGs are not well known after kidney transplantation. This study investigated PTG volume by ultrasound (US). Methods. US of PTG was performed immediately (US-0) and 12 months after (US-12) transplantation to identify glands in all recipients. We calculated the percentage reduction in PTG volume (R%PTG). We declared it significant when it was Ն35%. Bone biochemical markers and renal function were recorded sequentially. Results. Among engrafted patients, parathyroid US-0 was performed in 47 and US-0 and US-12 in 36. Some visible gland was observed upon US-0 in 13 recipients, a group that showed higher pretransplantation parathyroid hormone (PTH) levels than the remaining 34 patients with no visible glands (627 Ϯ 360.0 vs 280 Ϯ 240.9 pg/mL; P Ͻ .05). Of 36 recipients with US-0 and US-12, the baseline study identified PTGs in 12 patients (pϩ group), while the remaining 24 had no identified glands (pϪ group). In the pϩ group, no PTG, at US-12 were visible in four patients, and a significant R%PTG was observed in three at this time, representing a reduction in gland volume after transplantation among 58.3% of pϩ patients. There was a progressive reduction in PTH among both groups. Patients with glandular volume reduction displayed better renal function: serum creatinine 1.7 Ϯ .79 versus 2.9 Ϯ .74 mg/dL (P Ͻ .05). Conclusions. Transplantation reversed hyperparathyroidism and PTG volume among recipients who achieved nearly normal renal function.
Nefrología : publicación oficial de la Sociedad Española Nefrologia, 2007
Journal of the American College of Nutrition, 1995
The present study was undertaken to investigate the effect of dietary magnesium (Mg) deficiency o... more The present study was undertaken to investigate the effect of dietary magnesium (Mg) deficiency on plasma levels of parathyroid hormone (PTH) and calcitonin (CT), and the changes in tissue calcium (Ca) and phosphorus (P) content. Wistar rats were fed an Mg-deficient diet. Plasma levels of PTH and CT, and Ca and P content in plasma, whole blood, skeletal muscle, heart, kidney, femoral bone and brain, were determined after 7, 35, 42, 49, 56, 63 and 70 days. Mg deficiency significantly increased plasma levels of ionic Ca after 1 week of deficiency, and significantly increased total Ca in plasma and whole blood after 5 weeks. Whole blood and plasma levels of P decreased significantly after 8 and 5 weeks, respectively, in comparison with values obtained in pair-fed control rats. Plasma levels of CT were not modified by hypercalcemia and hypomagnesemia. Plasma PTH decreased significantly during the first 3 weeks, then recovered gradually, reaching control values in week 7 and remaining stable thereafter, despite elevated levels of ionic Ca. The Mg-deficient diet led to calcification in skeletal muscle, heart, kidney and femur, detectable as early as week 5. However, P content increased only in kidney after 1 week, decreased in heart and femur after 5 weeks, and did not change in muscle. The Mg-deficient diet did not significantly modify Ca or P content in brain. Mg deficiency led to tissue calcification and decreased P levels in blood, heart, and femur. These changes did not affect CT secretion. PTH appeared to be more closely related with hypomagnesemia than with hypercalcemia.
Nephro Urology Monthly, Sep 1, 2010
Background and Aims: Homocysteine is a sulphur amino acid derived from methionine. Epidemiologica... more Background and Aims: Homocysteine is a sulphur amino acid derived from methionine. Epidemiological studies show an association between hyperhomocysteinemia and an increased cardiovascular risk, a fact that has also been confirmed in patients with chronic renal failure. This study, conducted in stage 5 chronic kidney disease patients, seeks to define the prevalence of hyperhomocysteinemia, evaluate the clearance of homocysteine with dialysis, and describe the frequency of the mutation in the mutilen-tetrahydrofolate reductase enzyme and its relationship with plasma levels of homocysteine. Methods: The reduced percentage of homocysteine and clearance of urea were analysed every six months for seven years in patients on dialysis. Urea and total homocysteine in plasma were measured in each of these studies and the type of dialyser low or high permeability used and the dialysis duration was determined. A molecular study of the gene coding for mutilen-tetrahydrofolate reductase enzyme was carried out in a group of patients and any C-T point mutation at position 677 of this gene was investigated. Mutation was described as not present, heterozygous for this mutation or homozygous for lactation. Results: Neither the average levels of homocysteine before and after dialysis or the reduction percentage of homocysteine varied with gender, although purification of urea was higher in women. Comparisons of homocysteine levels and percentage reduction in this ratio according to the ultra filtration of the dialyser used showed significant results. The molecular study of the gene in mutilen-tetrahydrofolate reductase enzyme showed that mutation was present in 54.8%: 45.2% with heterozygous polymorphism and 9.7% with homozygous. Conclusions: Patients undergoing hemodialysis were found to have higher levels of urea and its clearance was greater with the higher the ratio of ultra filtration dialyser. Mutation of the gene in mutilen-tetrahydrofolate reductase enzyme was similar in our patients compared to the general population and had no impact on plasma levels of homocysteine.
American Journal of Hypertension, 1999
The American Journal of Surgery, 2007
The objective of the current study was to study different functional and anatomic features of the... more The objective of the current study was to study different functional and anatomic features of the hyperplastic gland and clinical and biochemical characteristics of renal hyperparathyroidism (HPT) patients and their relationship with the scintigraphic detection of parathyroid glands. A retrospective study was performed of 40 patients with chronic renal failure (CRF) who underwent cervical surgery for HPT. Weight, histology, and localization of hyperplastic glands were recorded. Parathyroid cell proliferation was assessed by percentage of S-phase cells. Double-phase scintigraphy with technetium 99m-sestamibi and serum parathyroid intact hormone (PTHi), creatinine, calcium, and phosphate levels were performed. Detection of hyperplastic parathyroid glands by 99mTc-sestamibi scintigraphy was associated with the weight and inferior localization of the glands. The functionality of the glands as reflected in serum PTHi and phosphorus levels was associated with the number of glands detected. Double-phase 99mTc-sestamibi scintigraphy is of limited usefulness in patients with renal HPT. Detection of hyperplastic parathyroid glands in patients with CRF depends on the weight and inferior localization of the glands. Serum PTHi, phosphorus and creatine levels are associated with the number of glands detected by means of 99mTc-sestamibi scintigraphy.
Research in Microbiology, 1991
Changes in total cellular composition of some ions and amino acids of the moderate halophile Dele... more Changes in total cellular composition of some ions and amino acids of the moderate halophile Deleya halophila were studied in response to external salinity changes. Among the 14 amino acids investigated, the cellular glycine and aspartic acid content increased with increasing salinity. D. halophila also accumulated Na+ at the highest external salt concentrations.
IEEE Transactions on Power Systems, 2005
Neurological Research, 1984
Fifty-four concomitant pairs of plasma and ventricular CSF samples were obtained in eighteen pati... more Fifty-four concomitant pairs of plasma and ventricular CSF samples were obtained in eighteen patients taking advantage of some neuroradiological or therapeutical procedures. A significant linear correlation between plasma and CSF beta-Endorphin levels has been found. The results obtained and those of other papers on the subject are discussed.
Diálisis y Trasplante, 2007
Introducción y objetivos: Cinacalcet es un fármaco que pertenece a un nuevo grupo terapéutico que... more Introducción y objetivos: Cinacalcet es un fármaco que pertenece a un nuevo grupo terapéutico que mejora la sensibilidad de la célula paratiroidea por el calcio. Si bien reduce los valores de parathormona (PTH) en el hiperparatiroidismo secundario (HPTS) que no responde a la terapia estándar, desconocemos su efecto en el remodelado óseo. En el presente estudio, pretendemos describir el efecto del cinacalcet en dos marcadores de remodelado óseo, beta-crosslap (marcador de resorción) y osteocalcina N-MID (marcador de formación) en pacientes afectos de enfermedad renal crónica en estadio 5-D (ERC 5-D) con HPTS. Material y método: Durante 21 semanas hemos realizado un estudio observacional no aleatorizado, sobre 10 pacientes en hemodiálisis afectos de HPTS tratados con cinacalcet. De manera secuencial, valoramos metabolismo calcio-fósforo mediante beta-crosslap y osteocalcina N-MID. Resultados: Observamos descenso del valor medio de parathormona a partir de la tercera semana (de 726 ± 396 hasta 427,8 ± 208,10 pg/ml; p < 0,01), más notorio en la semana 21 (181,2 ± 74,10 pg/ml; p < 0,01). No hubo cambios evolutivos de calcemia y fosforemia. Beta-crosslap y osteocalcina se redujeron de manera no significativa (beta-crosslap basal, 3.052,8 ± 1.417,40 pg/ml, frente a 1.001,2 ± 389,43 pg/ml en la semana 19; osteocalcina ba-sal, 549,4 ± 572,96, frente a 216,4 ± 88,7 ng/ml la semana 19). En ambos casos hubo aumento de ambos marcadores en la semana 21. Conclusiones: Nuestros datos indican que cinacalcet, además de reducir los valores de parathormona en pacientes urémicos con HPTS, modula el remodelado óseo con una tendencia a rebajar las concentraciones de beta-crosslap y osteocalcina.
Physiology & Behavior, 1998
We have evaluated the effect of Transcendental Meditation (TM) on the hypothalamo-hypophyseal-adr... more We have evaluated the effect of Transcendental Meditation (TM) on the hypothalamo-hypophyseal-adrenal axis diurnal rhythms through the determination of hormone levels. Blood samples were taken at 0900 hours.
International Journal of Yoga, 2014
to improve the mental state, inducing physiological changes based on these relationships. Yogic p... more to improve the mental state, inducing physiological changes based on these relationships. Yogic practices cause modulation of the immune system. [2] Transcendental meditation (TM), the main technology behind the Maharishi Vedic approach to health, is a simple, effortless and stylized form of physical and mental relaxation. [3] This technique is one of the most widely studied. Subjects practicing TM show specific electroencephalographic and metabolic patterns, changes in hormonal concentrations, low anxiety levels and improve levels of health. [4,5] In previous studies, our group reported modifications in the daily secretion pattern and lowered blood levels of catecholamines, β-endorphins and adrenocorticotropic hormone. We speculated with modification of hypothalamic and hypophyseal activity due to the regular practice of meditation. [6-8] Short Communication Context: Relationships between mind and body have gradually become accepted. Yogic practices cause modulation of the immune system. Transcendental meditation (TM) is a specific form of mantra meditation. We reported previously different plasma levels of catecholamines and pituitary hormones in TM practitioners comparing with a control group, and patterns of the daytime secretion of these hormones different from those normally described. Aims: The aim of the following study is to evaluate the immune system in these meditation practitioners, by determining leukocytes and lymphocytes subsets. Methods: TM group consisted of 19 subjects who regularly practice either TM or the more advanced Sidhi-TM technique. A control group consisted of 16 healthy subjects who had not previously used any relaxation technique. Total leukocytes, granulocytes, lymphocytes and monocytes were counted by an automated quantitative hematology analyzer, whereas lymphocytes subsets were determined by flow cytometry. Samples were taken from each subject at 0900 h after an overnight fast. Results: The results indicated that the TM group had higher values than the control group in CD3+CD4−CD8+ lymphocytes (P < 0.05), B lymphocytes (P < 0.01) and natural killer cells (P < 0.01), whereas CD3+CD4+CD8− lymphocytes showed low levels in meditation practitioners (P < 0.001). No significant differences were observed in total leukocytes, granulocytes, monocytes, total lymphocytes or CD3+ lymphocytes comparing both groups. Conclusions: The technique of meditation studied seems to have a significant effect on immune cells, manifesting in the different circulating levels of lymphocyte subsets analyzed. The significant effect of TM on the neuroendocrine axis and its relationship with the immune system may partly explain our results.
Transplantation Proceedings, 2007
Introduction. In dialysis patients, the parathyroid glands (PTGs) may increase progressively, pro... more Introduction. In dialysis patients, the parathyroid glands (PTGs) may increase progressively, producing abnormal bone metabolism. Changes in PTG volume among patients with hyperplastic PTGs are not well known after kidney transplantation. This study investigated PTG volume by ultrasound (US). Methods. US of PTG was performed immediately (US-0) and 12 months after (US-12) transplantation to identify glands in all recipients. We calculated the percentage reduction in PTG volume (R%PTG). We declared it significant when it was Ն35%. Bone biochemical markers and renal function were recorded sequentially. Results. Among engrafted patients, parathyroid US-0 was performed in 47 and US-0 and US-12 in 36. Some visible gland was observed upon US-0 in 13 recipients, a group that showed higher pretransplantation parathyroid hormone (PTH) levels than the remaining 34 patients with no visible glands (627 Ϯ 360.0 vs 280 Ϯ 240.9 pg/mL; P Ͻ .05). Of 36 recipients with US-0 and US-12, the baseline study identified PTGs in 12 patients (pϩ group), while the remaining 24 had no identified glands (pϪ group). In the pϩ group, no PTG, at US-12 were visible in four patients, and a significant R%PTG was observed in three at this time, representing a reduction in gland volume after transplantation among 58.3% of pϩ patients. There was a progressive reduction in PTH among both groups. Patients with glandular volume reduction displayed better renal function: serum creatinine 1.7 Ϯ .79 versus 2.9 Ϯ .74 mg/dL (P Ͻ .05). Conclusions. Transplantation reversed hyperparathyroidism and PTG volume among recipients who achieved nearly normal renal function.
Physiology & Behavior, 2001
With the aim of evaluating the sympathetic ± adrenal medulla system in subjects practicing transc... more With the aim of evaluating the sympathetic ± adrenal medulla system in subjects practicing transcendental meditation (TM), their plasma catecholamine levels were determined at two different times of day. The study group consisted of 19 subjects who regularly practice either TM or Sidhi-TM technique, with a control group made up of 16 healthy subjects who had not previously used any relaxation technique. Catecholamine plasma levels were determined by high performance liquid chromatography, at 0900 and 2000 h. Morning and evening norepinephrine (NE) levels and morning epinephrine (E) levels were significantly lower in the TM group than in the control subjects
Nutrition Research, 1993
The effects of a diet deficient in magnesium (0.022% Mg) on the bioavailability of dietary Ca and... more The effects of a diet deficient in magnesium (0.022% Mg) on the bioavailability of dietary Ca and phosphorus were studied in Wistar rats after 1, 5, 6, 7, 8, 9 and 10 weeks. Feeding with a diet deficient in Mg significantly increased Ca absorption and balance from the,first week until the end of the experimental period, and increased phosphorus absorbed in weeks 9 and 10. However, phosphorus balance became negative in first week of study, as a result of phosphaturia.
American Journal of Surgery, Apr 1, 2007
The objective of the current study was to study different functional and anatomic features of the... more The objective of the current study was to study different functional and anatomic features of the hyperplastic gland and clinical and biochemical characteristics of renal hyperparathyroidism (HPT) patients and their relationship with the scintigraphic detection of parathyroid glands. A retrospective study was performed of 40 patients with chronic renal failure (CRF) who underwent cervical surgery for HPT. Weight, histology, and localization of hyperplastic glands were recorded. Parathyroid cell proliferation was assessed by percentage of S-phase cells. Double-phase scintigraphy with technetium 99m-sestamibi and serum parathyroid intact hormone (PTHi), creatinine, calcium, and phosphate levels were performed. Detection of hyperplastic parathyroid glands by 99mTc-sestamibi scintigraphy was associated with the weight and inferior localization of the glands. The functionality of the glands as reflected in serum PTHi and phosphorus levels was associated with the number of glands detected. Double-phase 99mTc-sestamibi scintigraphy is of limited usefulness in patients with renal HPT. Detection of hyperplastic parathyroid glands in patients with CRF depends on the weight and inferior localization of the glands. Serum PTHi, phosphorus and creatine levels are associated with the number of glands detected by means of 99mTc-sestamibi scintigraphy.
Transplantation Proceedings, 2007
Introduction. In dialysis patients, the parathyroid glands (PTGs) may increase progressively, pro... more Introduction. In dialysis patients, the parathyroid glands (PTGs) may increase progressively, producing abnormal bone metabolism. Changes in PTG volume among patients with hyperplastic PTGs are not well known after kidney transplantation. This study investigated PTG volume by ultrasound (US). Methods. US of PTG was performed immediately (US-0) and 12 months after (US-12) transplantation to identify glands in all recipients. We calculated the percentage reduction in PTG volume (R%PTG). We declared it significant when it was Ն35%. Bone biochemical markers and renal function were recorded sequentially. Results. Among engrafted patients, parathyroid US-0 was performed in 47 and US-0 and US-12 in 36. Some visible gland was observed upon US-0 in 13 recipients, a group that showed higher pretransplantation parathyroid hormone (PTH) levels than the remaining 34 patients with no visible glands (627 Ϯ 360.0 vs 280 Ϯ 240.9 pg/mL; P Ͻ .05). Of 36 recipients with US-0 and US-12, the baseline study identified PTGs in 12 patients (pϩ group), while the remaining 24 had no identified glands (pϪ group). In the pϩ group, no PTG, at US-12 were visible in four patients, and a significant R%PTG was observed in three at this time, representing a reduction in gland volume after transplantation among 58.3% of pϩ patients. There was a progressive reduction in PTH among both groups. Patients with glandular volume reduction displayed better renal function: serum creatinine 1.7 Ϯ .79 versus 2.9 Ϯ .74 mg/dL (P Ͻ .05). Conclusions. Transplantation reversed hyperparathyroidism and PTG volume among recipients who achieved nearly normal renal function.
Nefrología : publicación oficial de la Sociedad Española Nefrologia, 2007
Journal of the American College of Nutrition, 1995
The present study was undertaken to investigate the effect of dietary magnesium (Mg) deficiency o... more The present study was undertaken to investigate the effect of dietary magnesium (Mg) deficiency on plasma levels of parathyroid hormone (PTH) and calcitonin (CT), and the changes in tissue calcium (Ca) and phosphorus (P) content. Wistar rats were fed an Mg-deficient diet. Plasma levels of PTH and CT, and Ca and P content in plasma, whole blood, skeletal muscle, heart, kidney, femoral bone and brain, were determined after 7, 35, 42, 49, 56, 63 and 70 days. Mg deficiency significantly increased plasma levels of ionic Ca after 1 week of deficiency, and significantly increased total Ca in plasma and whole blood after 5 weeks. Whole blood and plasma levels of P decreased significantly after 8 and 5 weeks, respectively, in comparison with values obtained in pair-fed control rats. Plasma levels of CT were not modified by hypercalcemia and hypomagnesemia. Plasma PTH decreased significantly during the first 3 weeks, then recovered gradually, reaching control values in week 7 and remaining stable thereafter, despite elevated levels of ionic Ca. The Mg-deficient diet led to calcification in skeletal muscle, heart, kidney and femur, detectable as early as week 5. However, P content increased only in kidney after 1 week, decreased in heart and femur after 5 weeks, and did not change in muscle. The Mg-deficient diet did not significantly modify Ca or P content in brain. Mg deficiency led to tissue calcification and decreased P levels in blood, heart, and femur. These changes did not affect CT secretion. PTH appeared to be more closely related with hypomagnesemia than with hypercalcemia.
Nephro Urology Monthly, Sep 1, 2010
Background and Aims: Homocysteine is a sulphur amino acid derived from methionine. Epidemiologica... more Background and Aims: Homocysteine is a sulphur amino acid derived from methionine. Epidemiological studies show an association between hyperhomocysteinemia and an increased cardiovascular risk, a fact that has also been confirmed in patients with chronic renal failure. This study, conducted in stage 5 chronic kidney disease patients, seeks to define the prevalence of hyperhomocysteinemia, evaluate the clearance of homocysteine with dialysis, and describe the frequency of the mutation in the mutilen-tetrahydrofolate reductase enzyme and its relationship with plasma levels of homocysteine. Methods: The reduced percentage of homocysteine and clearance of urea were analysed every six months for seven years in patients on dialysis. Urea and total homocysteine in plasma were measured in each of these studies and the type of dialyser low or high permeability used and the dialysis duration was determined. A molecular study of the gene coding for mutilen-tetrahydrofolate reductase enzyme was carried out in a group of patients and any C-T point mutation at position 677 of this gene was investigated. Mutation was described as not present, heterozygous for this mutation or homozygous for lactation. Results: Neither the average levels of homocysteine before and after dialysis or the reduction percentage of homocysteine varied with gender, although purification of urea was higher in women. Comparisons of homocysteine levels and percentage reduction in this ratio according to the ultra filtration of the dialyser used showed significant results. The molecular study of the gene in mutilen-tetrahydrofolate reductase enzyme showed that mutation was present in 54.8%: 45.2% with heterozygous polymorphism and 9.7% with homozygous. Conclusions: Patients undergoing hemodialysis were found to have higher levels of urea and its clearance was greater with the higher the ratio of ultra filtration dialyser. Mutation of the gene in mutilen-tetrahydrofolate reductase enzyme was similar in our patients compared to the general population and had no impact on plasma levels of homocysteine.
American Journal of Hypertension, 1999
The American Journal of Surgery, 2007
The objective of the current study was to study different functional and anatomic features of the... more The objective of the current study was to study different functional and anatomic features of the hyperplastic gland and clinical and biochemical characteristics of renal hyperparathyroidism (HPT) patients and their relationship with the scintigraphic detection of parathyroid glands. A retrospective study was performed of 40 patients with chronic renal failure (CRF) who underwent cervical surgery for HPT. Weight, histology, and localization of hyperplastic glands were recorded. Parathyroid cell proliferation was assessed by percentage of S-phase cells. Double-phase scintigraphy with technetium 99m-sestamibi and serum parathyroid intact hormone (PTHi), creatinine, calcium, and phosphate levels were performed. Detection of hyperplastic parathyroid glands by 99mTc-sestamibi scintigraphy was associated with the weight and inferior localization of the glands. The functionality of the glands as reflected in serum PTHi and phosphorus levels was associated with the number of glands detected. Double-phase 99mTc-sestamibi scintigraphy is of limited usefulness in patients with renal HPT. Detection of hyperplastic parathyroid glands in patients with CRF depends on the weight and inferior localization of the glands. Serum PTHi, phosphorus and creatine levels are associated with the number of glands detected by means of 99mTc-sestamibi scintigraphy.
Research in Microbiology, 1991
Changes in total cellular composition of some ions and amino acids of the moderate halophile Dele... more Changes in total cellular composition of some ions and amino acids of the moderate halophile Deleya halophila were studied in response to external salinity changes. Among the 14 amino acids investigated, the cellular glycine and aspartic acid content increased with increasing salinity. D. halophila also accumulated Na+ at the highest external salt concentrations.
IEEE Transactions on Power Systems, 2005
Neurological Research, 1984
Fifty-four concomitant pairs of plasma and ventricular CSF samples were obtained in eighteen pati... more Fifty-four concomitant pairs of plasma and ventricular CSF samples were obtained in eighteen patients taking advantage of some neuroradiological or therapeutical procedures. A significant linear correlation between plasma and CSF beta-Endorphin levels has been found. The results obtained and those of other papers on the subject are discussed.
Diálisis y Trasplante, 2007
Introducción y objetivos: Cinacalcet es un fármaco que pertenece a un nuevo grupo terapéutico que... more Introducción y objetivos: Cinacalcet es un fármaco que pertenece a un nuevo grupo terapéutico que mejora la sensibilidad de la célula paratiroidea por el calcio. Si bien reduce los valores de parathormona (PTH) en el hiperparatiroidismo secundario (HPTS) que no responde a la terapia estándar, desconocemos su efecto en el remodelado óseo. En el presente estudio, pretendemos describir el efecto del cinacalcet en dos marcadores de remodelado óseo, beta-crosslap (marcador de resorción) y osteocalcina N-MID (marcador de formación) en pacientes afectos de enfermedad renal crónica en estadio 5-D (ERC 5-D) con HPTS. Material y método: Durante 21 semanas hemos realizado un estudio observacional no aleatorizado, sobre 10 pacientes en hemodiálisis afectos de HPTS tratados con cinacalcet. De manera secuencial, valoramos metabolismo calcio-fósforo mediante beta-crosslap y osteocalcina N-MID. Resultados: Observamos descenso del valor medio de parathormona a partir de la tercera semana (de 726 ± 396 hasta 427,8 ± 208,10 pg/ml; p < 0,01), más notorio en la semana 21 (181,2 ± 74,10 pg/ml; p < 0,01). No hubo cambios evolutivos de calcemia y fosforemia. Beta-crosslap y osteocalcina se redujeron de manera no significativa (beta-crosslap basal, 3.052,8 ± 1.417,40 pg/ml, frente a 1.001,2 ± 389,43 pg/ml en la semana 19; osteocalcina ba-sal, 549,4 ± 572,96, frente a 216,4 ± 88,7 ng/ml la semana 19). En ambos casos hubo aumento de ambos marcadores en la semana 21. Conclusiones: Nuestros datos indican que cinacalcet, además de reducir los valores de parathormona en pacientes urémicos con HPTS, modula el remodelado óseo con una tendencia a rebajar las concentraciones de beta-crosslap y osteocalcina.
Physiology & Behavior, 1998
We have evaluated the effect of Transcendental Meditation (TM) on the hypothalamo-hypophyseal-adr... more We have evaluated the effect of Transcendental Meditation (TM) on the hypothalamo-hypophyseal-adrenal axis diurnal rhythms through the determination of hormone levels. Blood samples were taken at 0900 hours.
International Journal of Yoga, 2014
to improve the mental state, inducing physiological changes based on these relationships. Yogic p... more to improve the mental state, inducing physiological changes based on these relationships. Yogic practices cause modulation of the immune system. [2] Transcendental meditation (TM), the main technology behind the Maharishi Vedic approach to health, is a simple, effortless and stylized form of physical and mental relaxation. [3] This technique is one of the most widely studied. Subjects practicing TM show specific electroencephalographic and metabolic patterns, changes in hormonal concentrations, low anxiety levels and improve levels of health. [4,5] In previous studies, our group reported modifications in the daily secretion pattern and lowered blood levels of catecholamines, β-endorphins and adrenocorticotropic hormone. We speculated with modification of hypothalamic and hypophyseal activity due to the regular practice of meditation. [6-8] Short Communication Context: Relationships between mind and body have gradually become accepted. Yogic practices cause modulation of the immune system. Transcendental meditation (TM) is a specific form of mantra meditation. We reported previously different plasma levels of catecholamines and pituitary hormones in TM practitioners comparing with a control group, and patterns of the daytime secretion of these hormones different from those normally described. Aims: The aim of the following study is to evaluate the immune system in these meditation practitioners, by determining leukocytes and lymphocytes subsets. Methods: TM group consisted of 19 subjects who regularly practice either TM or the more advanced Sidhi-TM technique. A control group consisted of 16 healthy subjects who had not previously used any relaxation technique. Total leukocytes, granulocytes, lymphocytes and monocytes were counted by an automated quantitative hematology analyzer, whereas lymphocytes subsets were determined by flow cytometry. Samples were taken from each subject at 0900 h after an overnight fast. Results: The results indicated that the TM group had higher values than the control group in CD3+CD4−CD8+ lymphocytes (P < 0.05), B lymphocytes (P < 0.01) and natural killer cells (P < 0.01), whereas CD3+CD4+CD8− lymphocytes showed low levels in meditation practitioners (P < 0.001). No significant differences were observed in total leukocytes, granulocytes, monocytes, total lymphocytes or CD3+ lymphocytes comparing both groups. Conclusions: The technique of meditation studied seems to have a significant effect on immune cells, manifesting in the different circulating levels of lymphocyte subsets analyzed. The significant effect of TM on the neuroendocrine axis and its relationship with the immune system may partly explain our results.
Transplantation Proceedings, 2007
Introduction. In dialysis patients, the parathyroid glands (PTGs) may increase progressively, pro... more Introduction. In dialysis patients, the parathyroid glands (PTGs) may increase progressively, producing abnormal bone metabolism. Changes in PTG volume among patients with hyperplastic PTGs are not well known after kidney transplantation. This study investigated PTG volume by ultrasound (US). Methods. US of PTG was performed immediately (US-0) and 12 months after (US-12) transplantation to identify glands in all recipients. We calculated the percentage reduction in PTG volume (R%PTG). We declared it significant when it was Ն35%. Bone biochemical markers and renal function were recorded sequentially. Results. Among engrafted patients, parathyroid US-0 was performed in 47 and US-0 and US-12 in 36. Some visible gland was observed upon US-0 in 13 recipients, a group that showed higher pretransplantation parathyroid hormone (PTH) levels than the remaining 34 patients with no visible glands (627 Ϯ 360.0 vs 280 Ϯ 240.9 pg/mL; P Ͻ .05). Of 36 recipients with US-0 and US-12, the baseline study identified PTGs in 12 patients (pϩ group), while the remaining 24 had no identified glands (pϪ group). In the pϩ group, no PTG, at US-12 were visible in four patients, and a significant R%PTG was observed in three at this time, representing a reduction in gland volume after transplantation among 58.3% of pϩ patients. There was a progressive reduction in PTH among both groups. Patients with glandular volume reduction displayed better renal function: serum creatinine 1.7 Ϯ .79 versus 2.9 Ϯ .74 mg/dL (P Ͻ .05). Conclusions. Transplantation reversed hyperparathyroidism and PTG volume among recipients who achieved nearly normal renal function.
Physiology & Behavior, 2001
With the aim of evaluating the sympathetic ± adrenal medulla system in subjects practicing transc... more With the aim of evaluating the sympathetic ± adrenal medulla system in subjects practicing transcendental meditation (TM), their plasma catecholamine levels were determined at two different times of day. The study group consisted of 19 subjects who regularly practice either TM or Sidhi-TM technique, with a control group made up of 16 healthy subjects who had not previously used any relaxation technique. Catecholamine plasma levels were determined by high performance liquid chromatography, at 0900 and 2000 h. Morning and evening norepinephrine (NE) levels and morning epinephrine (E) levels were significantly lower in the TM group than in the control subjects
Nutrition Research, 1993
The effects of a diet deficient in magnesium (0.022% Mg) on the bioavailability of dietary Ca and... more The effects of a diet deficient in magnesium (0.022% Mg) on the bioavailability of dietary Ca and phosphorus were studied in Wistar rats after 1, 5, 6, 7, 8, 9 and 10 weeks. Feeding with a diet deficient in Mg significantly increased Ca absorption and balance from the,first week until the end of the experimental period, and increased phosphorus absorbed in weeks 9 and 10. However, phosphorus balance became negative in first week of study, as a result of phosphaturia.