[Influence of zinc administered by total parenteral nutrition on plasmatic zinc levels, on reactive C protein, on serum interleukin-6 and on serum interleukin-6 soluble receptor, in critical patients]. / Influencia del zinc administrado a pacientes críticos con nutrición parenteral sobre los niveles de zinc plasmático, proteína C reactiva, interleuquina-6 y receptor soluble de interleuquina-6.

OBJECTIVES: To study the interrelationship between serum Interleukin-6 (IL-6), serum Interleukin-6 soluble Receptor (IL-6 sR), C-Reactive Protein (C-RP), plasmatic Zinc levels (PlZn) and their response in relation to Zn administered by TPN, in critical patients. METHODS: 17 patients, receiving TPN as a consequence of acute pancreatitis (n = 4) or after a major abdominal surgery due to intestinal cancer (n = 7), intestinal fístula (n = 3), intestinal obstruction (n = 2) or intestinal íleus (n = 1) were studied. At the beginning (To) and at the end of the TPN administration (6-21 days) serum IL-6 and IL-6 sR were determined by ELISA; C-RP ultrasensitive (C-RP us) by inmunoturbidimetric method; Zn was determined in TPN and in plasma by Atomic Absorption Spectrometry. Characteristics of the patients were (mean +/- SD and ranges): age: 60.6 +/- 11.7 (37-77) years; BMI (kg/m(2)): 26.0 +/- 3.4 (19.9-34.0). RESULTS: The results (mean +/- standard deviation and ranges) were: Zn provided by TPN (mg/d): 6.1 +/- 2.0 (range 2.8 to 10.8). Biochemical levels were, at To and Tf, respectively: (mean+/-SD and ranges) were at To y Tf, respectively: Zn Pl (microg/dl): 104 +/- 46 (35-177); 120 +/- 55 (52-229); IL-6 (pg/mL) 93 +/- 74 (10-262); 117 +/- 180 (7-761); IL6sR (pg/mL): 1,012 +/- 322 (589-1855); 1,269 +/- 451 (631-2195); C-RP us (mg/L): 71 +/- 63 (2-196); 65 +/- 43 (0-137). There was no correlation between variations of IL6, IL6sR, C-RP, PlZn levels and the daily amount of Zn administered in the TPN mixtures. Two patients presented a bad evolution; they received 4.2 and 5.2 md/d of Zn and showed an increase of IL6 levels, maintained high levels of IL6sR but C-RP levels decreased. CONCLUSIONS: the range of 2.8 to 10.8 mg/d of Zn administered in TPN mixtures did not exacerbate the inflammatory response.

Body composition and bone metabolism in young Gaucher disease type I patients treated with imiglucerase.

UNLABELLED: Bone involvement is one of the most disabling complications in patients with type 1 Gaucher disease (GDI) and its pathophysiology is yet to be fully understood. It is well known that body composition is a determinant of bone mass. Previous reports indicating disturbance in glucose and lipid metabolism in GDI patients suggested a posible alteration in body composition in this group of patients. OBJECTIVE: To analyze body composition, bone mass and turnover in young adults with GDI receiving enzyme replacement therapy (ERT). POPULATION: 5 women and 4 men with GDI aged (X +/- SD) 26.9 +/- 6.9 years, receiving imiglucerase in a mean dose of 53 +/- 13 IU/kg/2weeks, during 4.9 +/- 3.9 years; and 145 sex and age matched healthy adults agreed to participate in the study. All control subjects had a body mass index (BMI) between 20 and 25 kg/m2. METHODS: Total body dual X-ray absorptiometry (DXA) was used to measure body composition and bone mass. Serum creatinine, calcium, osteocalcin (BGP), and type I collagen beta carboxy-terminal telopeptide (betaCTX) were determined in patients and controls. In addition, 25 hydroxyvitamin D (25OHD), and chitotriosidase activity were measured in patients. RESULTS: GDI patients presented statistically significant (p<0.01) lower BMI, bone mineral density (BMD), bone mineral content (BMC), lean mass (LM), and fat mass (FM), compared to controls. LM correlated positively with BMC and BMD in both groups (p<0.01). GDI patients receiving the lower dose of ERT (<60 IU/kg/2weeks) presented lower BMD values than those receiving the higher dose (> or =60 IU/kg/2weeks) (0.968 +/- 0.032 vs 1.088 +/- 0.061 g/m2, respectively, p<0.001). Mean BGP levels were similar in patients and controls, whereas betaCTX levels were higher in GDI patients (p<0.02). All patients presented deficiency levels (<30ng/ml) of 25OHD. CONCLUSIONS: Although the patients had been receiving ERT, they presented a significant diminution in all body composition parameters, the decrease was more evident in those receiving the lower dose. The reduction in bone mass was associated with an imbalance in bone turnover (increased bone resorption). The correlation between LM and bone mass, suggests that metabolic disturbance occurring in GDI patients may be indirectly responsible for bone mass reduction in GDI patients, by altering body composition.

Primary antiphospholipid syndrome associated with small aorta syndrome: a case report.

It has been widely accepted that the antiphospholipid syndrome (APS) is an autoimmune hypercoagulability syndrome in which a variety of venous and arterial thrombotic events may occur. Peripheral obliterating arterial disease characterized by aortoiliac steno-occlusion occurring in young women, is reported in the literature under the name of Small Aorta Syndrome (SAS). Although it remains unclear whether SAS represents a separate entity, the small size of the distal aorta increases the risk for aortoiliac occlusive disease. A 41-year old white woman was admitted with acute digital ischemia of the left foot. She had positive lupus anticoagulant and IgG anti-cardiolipin antibodies (61 UI/mL), but antinuclear antibodies and anti-ds-DNA antibodies were negative. She previously had two deep venous thromboses of the legs and, despite the oral anticoagulant therapy, pulmonary embolism occurred. Shortly thereafter, abdominal angio-magnetic resonance imaging suggested that the infra-renal aorta was narrowed more than 50%, without thrombotic occlusion of the terminal aorta and common iliac arteries. These findings were compatible with the features of SAS. There were no atherosclerotic changes in the artery wall and no other prediposing risk factors such as smoking, oral contraceptive or hyperlipidemia. After adequate anticoagulation and intravenous prostacyclin treatment the patient's symptoms and the ischemic lesions improved markedly. To our knowledge this is the first report of the association of SAS and primary APS. The occurrence of SAS in patients with APS may dramatically increase the risk of trombothic events.

Telopeptido carboxilo terminal del colageno tipo i ( beta-ctx ) serico y / compromiso oseo en la insuficiencia renal cronica / Serum beta-type I collagen carboxyterminal telopeptide ( beta-CTXs ) and bone involvement in chronic renal failure

La osteodistrofia renal (ODR) se caracteriza por alteraciones óseas. Se evaluaron métodos bioquímicosalternativos a la biopsia ósea en pacientes renales para determinar cambios rápidos delremodelamiento óseo en 43 pacientes predialíticos (PD) y 49 hemodializados (HD). Los PD presentaronfosfatemia, fosfatasa alcalina ósea (FAO), hormona paratiroidea intacta (PTHi) y beta-telopéptido carboxilo terminaldel colágeno tipo I (betaCTXs) mayores y clearence de creatinina (Ccr) menores (p<0.001) que los controles.La fosfatemia de HD fue más elevada, significativamente respecto de controles (p<0.0001); FAO, PTHi y betaCTXsfueron mayores a los otros dos grupos (p<0.0001). En ambos grupos renales betaCTXs y FAO correlacionaroncon PTHi (p<0.002 y p<0.0001, respectivamente) y entre sí (p<0.0001). Los PD con Ccr <40 ml/min presentaronPTHi, FAO y bCTXs (p<0.004, p<0.05 y p<0.001, respectivamente) más elevados que aquellos con Ccr>40ml/min. En PD, betaCTXs (p<0.05) y en HD tanto betaCTXs como FAO (p<0.0001) estaban aumentados respecto decontroles, aun con PTHi normal. Los incrementos mayores en los marcadores óseos se observaron en los pacientescon mayores niveles de PTHi (p<0.001). En conclusión; aun sin PTHi elevada existe un aumento deresorción ósea (posiblemente por otros factores) y la medición de betaCTXs sería una herramienta apropiada notraumática para detectar tempranamente alteraciones óseas por IR que permitiría tomar medidas preventivaspara evitar dicha pérdida. Asimismo, instalada la ODR determinar el aumento del remodelamiento sería sumamenteútil para identificar pacientes que requieran biopsia ósea. El reemplazo de la misma por beta-CTX séricodeberá esperar estudios que demuestren la correlación existente entre ambas metodologías.

[Raynaud's phenomenon]. / Il fenomeno di Raynaud.

Raynaud's phenomenon (RP) is a vasospastic disorder characterized by episodic color changes of blanching, cyanosis, and hyperemia in response to cold and/or emotional stress. Although most typically noted in the fingers, the circulation of the toes, ears, nose and tongue is also frequently affected. Population studies have shown that RP in adults is more common in women than men, with prevalence estimates ranging from 4% to 30%. Geographic variations in the prevalence reflect differences in climate. RP may be a primary or a secondary process. LeRoy and Medsger suggested criteria for primary RP: symmetric attacks, the absence of tissue necrosis, ulceration or gangrene, the absence of a secondary cause, negative antinuclear antibodies, normal nailfold capillaroscopy and a normal erythrocyte sedimentation rate. Secondary RP is characterized by an age of onset of more than 30 years, painful and asymmetric attacks, ischemic skin lesions, positive autoantibodies, capillaroscopic abnormalities and/or clinical features suggestive of connective tissue diseases (CTDs). Among the CTDs, systemic sclerosis has the highest frequency of RP. Finding a cause for RP requires a knowledge of the patient's occupational, smoking, drug history, physical examination, nailfold capillaroscopy, routine laboratory tests and autoantibodies. Furthermore, RP should be distinguished from acrocyanosis, a condition characterized by continuous cyanosis of the hands or feet that is aggravated by cold temperature. The most important instruction to the patient is abstinence from any smoking, offending drugs should be discontinued, and abrupt changes in temperature. If these measures are inadequate, calcium-channel blockers are the most widely used (nifedipine 30 mg up to 90 mg daily). Alternatively, sympatholytic agent (prazosin), angiotensin II -receptor type I antagonist (losartan), selective sertonin-reuptake inhibitor (fluoxetine) may be useful. In the severe cases the role of prostaglandins is well established, but standard therapeutic protocols are not jet available.

Bone mass changes in vivo during the entire reproductive cycle in rats feeding different dietary calcium and calcium/phosphorus ratio content.

The purpose of this study was to quantify in vivo the impact of different dietary Ca contents on the maternal total skeleton and skeletal sub-areas in adult rats during pregnancy and lactation, using DXA. Twenty-four female Wistar rats (approximately 5 months old) were mated and divided into three groups (n = 8) and fed one of the following diets, varying only in Ca content (LCD: 0.14%, NCD: 0.6% or HCD: 1.2%). Pups were adjusted to 8-9 per dam. Maternal ionic calcium and in vivo bone mineral density (BMD) were measured at the beginning, after delivery and after weaning. Regardless of the diet, ionized calcium decreased from onset to weaning ( P < 0.05). At weaning, bone mass decreased 7.3% in NCD, 15% in LCD and 10.5% in HCD from initial values. Total skeleton, whole and proximal tibia and spine BMDs only decreased at delivery in the LCD group ( P < 0.05) but, irrespective of the diet, at weaning, they were lower compared to delivery and initial values ( P < 0.05). LCD group presented the lowest BMD in the proximal tibia and spine regions ( P < 0.05). At birth, pups did not present differences, however, at weaning, LCD pups reached the lowest body weight ( P < 0.05), NCD presented the highest body Ca content ( P < 0.05) and there were no differences between LCD and HCD. This in vivo study showed that regardless of the dietary calcium content, the maternal skeleton is slightly affected by pregnancy but severely affected by lactation. However, the degree of such response appears to depend not only on dietary Ca content but also on dietary Ca/P molar ratio.

Efecto del nivel de calcio de la dieta consumida durante gestación y lactancia sobre el zinc en sangre y hueso, en ratas / Effect of dietary calcium during pregnancy and lactation on zinc levels in blood and bone, in rats

The effect of dietary calcium (Ca) level on maternal zinc (Zn) nutritional status was studied. Female Wistar rats, weighing 250-350 g, were fed during pregnancy and lactation with an experimental diet containing/100 g different levels of calcium: 0.2 g (low calcium: LCa), 0.6 g (normal calcium: NCa) or 0.9 (high calcium: HCa). Maternal blood samples were drawn from the tail at delivery and at the end of lactation. Laboratory determinations were: Zn in whole blood (WB) at delivery and weaning; Zn (ZnF) and Ca (CaF) in the ashed femur at weaning. The results (mean +/- SEM) were: ZnWB (microgram/ml) at delivery and weaning: LCa: 8.73 +/- 1.05; 12.8 +/- 2.02; NCa: 3.49 +/- 0.19; 3.73 +/- 0.37; HCa: 3.21 +/- 0.19; 3.85 +/- 0.27. CaF (mg/100 mg): LCa: 19.2 +/- 0.8; NCa: 21.4 +/- 0.6; HCa: 20.4 +/- 1.1. ZnF (microgram/100 mg): LCa: 30.2 +/- 0.9; NCa: 24.1 +/- 0.3; HCa: 24.1 +/- 0.9. ZnWB was significantly higher in LCa (p < 0.0001) regarding NCa and Hca. ZnF showed an increase and CaF a decrease in LCa regarding NCa and HCa (p < 0.0001). There were no significant differences in ZnWB, ZnF and CaF between NCa and HCa These results show that: there was no detrimental effect when dietary Ca content was increased by 50 per cent above the normal requirements of the rat.; low dietary Ca during pregnancy and lactation produced an increase of Zn utilization, reflected in maternal blood Zn and in ZnF content.

Dietas desequilibradas en niños preescolares: estudio en un jardín integral de la provincia de Buenos Aires, Argentina / Imbalance diets in preschool children: study in a day-care center in the Province of Buenos Aires, Argentina

The purpose of this study was to investigate the impact of low fat diets in children aged 2 to 5. Eighty two children (40 females and 42 males) attending a school cafeteria (Province of Buenos Aires, Argentina), in a cross sectional study, were evaluated. Body weight (W), height (H) and body composition (BC) by bioimpedance were recorded. The anthropometric raw data were processed as Z-score of the weight-for-age (WEZ) and of the height-for-age (HAZ). Serum insulin-like growth factor 1 (IGF-1) and Zinc/haemoglobin ratio (Zn/Hb) were also measured. Results showed that 73.2 per cent of children were adequate (A) according WEZ, 13.4 per cent were lean (L) and 13.4 per cent overweight (O). 8.5 per cent presented simultaneously impairment in WEZ and HAZ. Body fat percentage and energy metabolism were higher in O than in L and A (p < 0.05). Serum IGF-1's children--aged 4 to 5 years--with HAZ deficit were low than adequate HAZ ones. No statistical differences in Zn/Hb ratio between A, L and O were found. This cross sectional study suggests metabolic disorders in young children attending school cafeterias. These conclusions will allow to design balanced diets in order to optimize the resources, promote optimal growth and development and prevent adult diseases through dietary practices in childhood.

Reversal of CSF positivity for JC virus genome by cidofovir in a patient with systemic lupus erythematosus and progressive multifocal leukoencephalopathy.

We report the case of a 36-year-old woman affected by systemic lupus erythematosus who developed rapidly progressive multifocal leukoencephalopathy. Cidofovir therapy induced disappearance of JC virus genome from the cerebrospinal fluid and stabilization of the MRI picture. Despite the fatal outcome after a few months of disease, cidofovir treatment deserves further testing as single antiviral therapy in HIV-negative PML patients.

Utilidad clínica de los marcadores de formación y resorción ósea / Clinical utility of biochemical merkers of bone turnover

Se evaluó el recambio óseo en distintas situaciones fisiológicas y patológicas que alteran el metabolismo óseo. A tal fin se analizó la utilidad de un marcador bioquímico de formación como la fosfatasa alcalina ósea (FAO) y uno de resorción ósea, como la fracción carboxilo terminal del telopéptido del colágeno tipo I (CTX). En la población adulta normal los hombres y mujeres premenopáusicas no presentaron diferencias significativas. Contrariamente, las mujeres posmenopáusicas tuvieron niveles de FAO y CTX significativamente mayores que éstos dos grupos (p<0,01). Entre el segundo y tercer trimestre de embarazo ambos marcadores aumentaron significativamente (FAO: p<0,009 y CTX: p<0,0003). Mientras la FAO no varió en posmenopáusicas ante el tratamiento hormonal de reemplazo (THR), el CTX disminuyó significativamente (p<0,001). Mujeres posmenopáusicas osteopénicas y osteoporóticas presentaron niveles de CTX y FAO significativamente menores luego de THR o tratamiento con bifosfonatos respecto de las no tratadas (FAO: p<0,05 y 0,03 y CTX: p<0,02 y 0,0001 respectivamente). Pacientes con insuficiencia renal en hemodiálisis presentaron niveles séricos de FAO y CTX significativamente mayores que los controles sanos por edad y sexo (p<0,05). Pacientes hipertiroideos, pagéticos o con patología ósea secundaria a enfermedad celíaca disminuyeron los niveles de FAO y CTX en forma significativa (p<0,05) luego del tratamiento específico. Como se esperaba, el marcador de resorción respondió más rápidamente a cambios en el remodelamiento óseo. Si le sumamos la alta especificidad y sensibilidad del CTX, se sugiere que éste marcador sería de utilidad en todas aquellas patologías en que se sospeche alteración o se quiera determinar el grado del remodelamiento óseo

The effect of olpadronate in ovariectomized thyroxine-treated rats.

Hyperthyroidism increases bone turnover and induces bone loss. This study examines the effect of thyroid hormone excess on two biochemical markers of bone turnover (hydroxyproline and bone alkaline phosphatase) as well as on bone mineral content (BMC) and bone mineral density (BMD). The possible protective role of dimethyl-APD (olpadronate, OLP), on both suppression of bone turnover and bone mineral loss in ovariectomized (ovx) rats, was also studied. Female Sprague-Dawley rats, were assigned to five groups of eight rats each: sham, ovx, ovx OLP treated (0.3 mg/kg per week), ovx T4 treated (250 micrograms/kg per day), and ovx T4-OLP rats. Rats were killed after 5 weeks of treatment. At the end of the study, blood samples were analyzed for serum calcium, phosphorus, T4, total and bone alkaline phosphatase (ALP and b-ALP), and urinary samples for hydroxyproline/creatinine ratio (HOProl/creat). Moreover, total BMC, BMD, and scanned area were determined by DXA. Ovx T4-OLP-treated rats presented higher values of b-ALP than ovx T4-treated, ovx, and sham rats (p < 0.05). Ovx increased HOProl/creat excretion compared with sham (p < 0.05), but it was similar compared with ovx T4-treated rats. OLP treatment reduced HOProl/creat excretion in both ovx T4-treated (p < 0.05) and ovx rats (p < 0.05). The final BMC in ovx was lower than in the sham group, but the difference was not statistically significant (p < 0.08). The lowest BMC was observed in ovx T4 rats (p < 0.05). When final BMC was expressed per body weight (BMC/W), ovx rats presented a significantly lower BMC/W than sham rats (p < 0.05). Ovx OLP rats had BMC/W levels higher than ovx (p < 0.005), ovx T4 (p < 0.01), and ovx T4-OLP rats (p < 0.01). The ovx group had a final BMD lower than sham animals (p < 0.05), but not significantly different than the ovx T4 rats. BMC and BMD of OLP ovx rats, whether they received T4 or not, was similar to the sham group. The highest final BMD was observed in the ovx T4-OLP group. In summary, the prevention of an increase in HOProl excretion accompanied by the fact that final BMD and BMC in OLP-treated animals were comparable to sham control rats may reflect that OLP administration could inhibit bone resorption in both T4-treated or -untreated rats. Although further studies are necessary, these findings may have clinical relevance in estrogen-depleted patients to whom medical management other than the reduction of T4 administration would be desirable.

Fibromyalgic syndrome: depression and abnormal illness behavior. Multicenter investigation.

This study reports psychological symptoms assessed in 327 patients with fibromyalgia (FS) in a multicenter investigation. Two self-report scales, in their validated Italian translations, were used for screening: the CES-D (the Center of Epidemiologic Studies-Depression) developed at the NIMH for measuring depression and the Illness Behavior Questionnaire (IBQ) developed by Pilowsky and Spence. The cutoff point of 23 in the CES-D scores revealed about 49% of the fibromyalgic patients as depressed. In analyzing patterns of illness behavior patients with FS showed a high score on IBQ scales of disease conviction, psychological versus somatic focusing and denial. CES-D scores showed significant correlations with illness behavior scales. These results and their implications for the treatment of fibromyalgic patients are discussed.

Compensatory parathyroid hypertrophy after hemiparathyroidectomy in rats feeding a low calcium diet.

The functional and anatomic compensatory response of the parathyroid gland was examined in hemiparathyroidectomized (HPTx) rats whose parathyroid hormone (PTH) secretion was stimulated by a low calcium diet. These responses were compared with those observed in the thyroid gland of hemithyroidectomized (HTx) rats. Rats kept on a low calcium diet for 10 days were subjected to HPTx, HTx, or sham operations. Throughout the experiment (up to 28 days after surgery), serum calcium levels of HPTx rats were lower than the basal, with delta values (mg/dl, mean +/- SEM) of -0.66 +/- 0.17 and -0.84 +/- 0.17, (P less than 0.05) 3 and 28 days after surgery, respectively. Serum PTH decreased significantly from 7 to 21 days after HPTx, reaching normality at day 28 after surgery. In HTx rats, serum thyroxine (T4) levels diminished significantly 7 days after surgery, and attained normality thereafter. The mitotic index (number of metaphases/1,000 cells) in parathyroid glands of colchicine-treated HPTx rats increased significantly in comparison to sham-operated controls, when examined 2 or 40 days after surgery. The mitotic index of thyroid follicular cells was significantly higher than that of their respective controls, 2 but not 40 days after HTx. These results indicate that after HPTx, a delayed compensatory response is found when the animals are kept under a low calcium diet. Parathyroid response is both delayed and of a minor degree compared to that found in the thyroid gland after HTx.

[Interrelationship between vitamin D intake and absorption and retention of calcium during nutritional recovery]. / Interrelaciones entre ingesta de vitamina D y absorción y retención de calcio durante la recuperación nutricional.

We have previously reported that, in the first stages of nutritional recovery, the needs of undernourished infants, in terms of protein-calories percentage (P%) are higher than normal, producing an accelerated catch-up. Consequently, calcium (Ca) and phosphorus (P) balances increase proportionally to weight gain rate (WGR) in order to attain a normal body composition. As for the control of Ca metabolism by vitamin D, the question is whether vitamin D intake must also be increased during this accelerated catch-up growth period. In this report we have analysed retrospectively previous results in order to clarify the interrelationship between Ca absorption, Ca retention and vitamin D intake. A total of 29 undernourished infants, from 2 to 18 months of age, were fed Ad libitum with one of two proprietary milk formulas containing, per 100 g.: Ca, 0.50 and 1.17 g.; P, 0.37 and 0.50 g.; vitamin D, 350 and 400 UI (8.7 and 10 micrograms); proteins, 11.34 and 17.00 kcal/100 kcal of total diet, respectively. Recommended Dietary Allowances (RDA) of Ca and vitamin D, according to FAO/OMS and NRC, were calculated with reference to normal infants body weight and to 1000 kcal of recommended dietary energy intake. Ca intake was higher than the RDA and ranged between 60 and 413 mg/kg/day; intake of vitamin D increased proportionally to food intake; calcium absorption ranged between 40.0 and 92.0% (mean = 69.8 +/- 14.6) and CaB correlated with Ca intake (r = 0.97), being higher than normal.(ABSTRACT TRUNCATED AT 250 WORDS)

Utilizacion de la relacion calcio/creatinina urinaria como indicador del estado nutricional con respecto al calcio. / Use of urinary calcium/creatinine ratio as indicator of the nutritional status regarding to calcium.

Se estudio la relacion calcio/creatinina (Ca/Creat.) en orina basal como posible indicador del estado nutricional con respecto al calcio. A un grupo de escolares con edades comprendidas entre 5 y 12 anos se les aplico un programa de complementacion alimentaria. Luego se selecciono una submuestra en la que, por haber existido reemplazo total del alimento, pudo determinarse la ingesta diaria de calcio. No se observo minguna correlacion entre la relacion Ca/Creat. y la ingesta de Ca en mg/ dia, pero si al expresar la ingesta en mg/ Kg/dia (r=0.67). Se encontro correlacion entre dicha relacion y la velocidad de crecimiento cuando los ninos se agruparon segun su ingesta: mayor o menor de l0 mg/ Kg/dia (r=0.82 y 0.89 respectivamente).La extrapolacion del valor de la relacion Ca/Creat. en dichas rectas a crecimiento nulo (delta P = 0) indicaria el indice correspondiente al recambio de calcio para dicha ingesta: 0.068 y 0.096 para ingestas de calcio menores o mayores de 10 mg/Kg/ dia, respectivamente. Estos hechos sugieren la posibilidad de aplicar la relacion Ca/Creat. para evaluar el estado nutricional con respecto al calcio, como indicador para estudios de campo.}