Jaffe Reaction Research Articles

Predisposición adquirida al daño renal asociada al consumo de tabaco

En los últimos años se ha visto una relación entre el tabaquismo y el daño renal. En cuanto al diagnóstico temprano del daño renal, nuestro grupo ha desarrollado el concepto de predisposición, aplicable al contexto de pacientes fumadores. Así, nuestra hipótesis es que el tabaco podría causar predisposición a sufrir daño renal agudo (DRA), lo que supondría que los fumadores podrían padecer DRA tras ser expuestos a alguna nefrotoxina, incluyendo dosis inferiores al límite tolerable. Nuestro objetivo es estudiar la relación entre los biomarcadores caracterizados en nuestro laboratorio: 1, 2 y 3 (BM1, BM2 y BM3) y el consumo de tabaco.Se tomaron muestras de orina de pacientes fumadores y no fumadores, sin daño renal ni exposición a factores de riesgo de este. Se midieron la cotinina (ELISA), la creatininuria (kit comercial) y los biomarcadores (western blot). La creatinina plasmática se obtuvo del historial clínico de los pacientes.Solo se vio una mayor excreción de BM3 en fumadores con respecto a no fumadores, aunque no se obtuvo una correlación con los niveles de cotinina (metabolito de nicotina que informa del grado de tabaquismo). A pesar de ello, BM3 podría suponer un buen biomarcador clínico para detectar la predisposición al DRA, lo que ayudaría a prevenir el daño renal en pacientes fumadores.

Cobalt accumulation in horses following repeated administration of cobalt chloride.

To monitor cobalt concentrations in urine, red blood cells and plasma after chronic parenteral administration of cobalt chloride evaluate these results against the current International Federation of Horseracing Authorities thresholds for detecting cobalt misuse. Eight mares were randomly assigned to four treatment groups, with two mares in each group: Group 1 - control group, Group 2 - 25 milligrams cobalt intravenously as CoCl2 weekly, Group 3 - 50 milligrams cobalt intravenously as CoCl2 weekly, and Group 4 - 25 milligrams cobalt intravenously mid-week and at the end of the week. Urine and blood samples were collected before each weekly administration so that trough levels were assessed. In the group receiving two doses per week, urine and blood were collected prior to the dose given at the end of each week. Samples were initially collected at time zero then weekly for 10 weeks. Three further collections of urine and blood were made at days 81, 106 and 127. Urine creatinine measurements to assess horse hydration status were performed by the Jaffe reaction method. Cobalt determinations in plasma, blood and urine were by inductively coupled plasma-mass spectrometry. Haematocrit concentrations, used to calculate red cell cobalt levels, were performed using a microhematocrit centrifuge. Statistical analyses were conducted in Genstat (v17, VSNi). Marked cobalt accumulation was evident with increasing cobalt concentrations for all sample matrices in specimens collected immediately prior to cobalt administration. Correlation between the sample matrices improved when urine cobalt concentration was adjusted for creatinine level. Red cell cobalt levels remained elevated for at least 12 weeks after cessation of administration, consistent with the lifespan of the red cell. There was no significant change in haematocrit concentrations for the duration of the study. The current urine cobalt threshold was only effective at detecting acute cobalt exposure while the plasma cobalt threshold was able to consistently identify chronic high-level cobalt exposure and potential cobalt misuse. The threshold values legislated for urine cobalt do not correlate with those set for plasma. The acute nature of urinary cobalt excretion provides a relatively small window through which cobalt administration is detected. Plasma and red cell cobalt concentrations can provide a clearer picture of potential cobalt misuse.

Impact of Dietary Protein intake, Lean Body Mass percentage, Body Mass Index, Physical activity on Urinary Creatine and Urinary Creatinine excretion in a TeamSport

Background: Creatine and Creatinine plays a role in muscle function. Urinary creatine and urinary creatinine concentration was measured in order to see significance in monitoring athlete and athlete’s performance. Objective: Evaluate association of dietary protein intake, Lean Body Mass (LBM) percentage, Body Mass Index (BMI) and physical activity on urinary creatine, urinary creatinine concentration in different team sports [cricket players (C), basketball players (B) and football players (F)]. Methodology: A total of 62 players from different team sports - C (n-20), B (n-17) and F (n-25) age of 18-30 years participated. Post training urine samples was analyzed. Using Jaffe's reaction, urinary creatinine was obtained and Urinary creatine is obtained by difference in the creatinine present before and after heating with acid solution. 24 hour dietary recall was taken to find athletes protein intake. LBM were taken using Body Impedence Analysis (BIA machine). Data were analysed using SPSS (Statistical Package for Social Sciences Version 16.0). Findings: Pearson bivariate correlation (2-tailed) was used to find the relationship between BMI, LBM, total dietary protein intake per day, dietary protein, duration of practice with urine creatinine and creatine level. Positive correlation between urinary creatine and total dietary protein intake per day, dietary protein according to body weight per day was found (p<0.001), (p<0.005) respectively. Negative correlation between urinary creatinine and dietary protein according to body weight per day and duration of practice per day was found (p<0.001), (p<0.005) respectively. Urinary creatine mean (SD) values- C group 78.63 ± 27.17, B group 102.65 ± 38 and F group 169.60±41.58. Urinary creatinine mean (SD) values- C group 46.60 ± 37.23,B group 84.88 ± 48.27 and F group 70.40±44.083. Conclusion & Significance: Significant increase was seen in urinary creatine excretion with respect to dietary protein per day, dietary protein according to body weight per day. Urinary creatine excretion is more in football players followed by basketball players. Significant decline was seen in urinary creatinine excretion with respect to increase dietary protein according to body weight per day and increase duration of practice. Urinary Creatine excretion is more in basketball players followed by football players Urinary creatine and urinary creatinine excretion depends on sports-type, duration of sports and protein consumption.

Simultaneous Determination Of BUN-Creatinine as Kidney Function Biomarkers in Blood using a Microfluidic Paper-based Analytical Devices

In this paper, we describe a Microfluidic Paper-based Analytical Devices (μPADs) for the simultaneous quantification of two important biomarkers of kidney function in blood. This paper provides a simple, disposable, portable, and inexpensive colorimetric method for the quantification of Blood Urea Nitrogen (BUN) and serum creatinine (sCRE). BUN detection is based on the Berthelot reaction, in which urea is converted to ammonium by the use of urease, ammonium ion which then reacts with a mixture of salicylate, sodium nitroprusside, and hypochlorite to yield a blue-green chromophore. sCRE detection is based on the Jaffe reaction, in which sCRE under alkaline conditions react with picrate ions forming an orange complex. The intensity of the color formed is proportional to the BUN & sCRE concentration in the sample. Various experimental parameters were optimized to achieve the best performance of the μPADs. There were no significant differences between the results obtained using the μPADs and a comparative method.

Picric acid: its extraction purification from dinitrophenols and analytical applications

A procedure of extraction purification of picric acid from impurities of dinitrophenols with diethyl ether at pH = 3 has been developed. Purified picric acid was used to determine the creatinine by the Jaffe reaction on model systems and the extraction-photometric determination of the basic substance in higher quaternary ammonium (QAS) and amine impurities in them. It was shown that both the purity and the concentration of picric acid affect the sensitivity of the creatinine quantification. It was found that to determine creatinine, a solution of HPic with a concentration of 0,035 mol/l should be used. The determination of amines in the QAS and basic substance is also necessary to be carried out only with purified picric acid to avoid distortion of the results.

Efek Konsumsi Minuman Beralkohol terhadap Kadar Kreatinin

Long-term and excessive alcohol consumption is a risk factor for chronic diseases such as impaired kidney function. Acute and chronic alcohol consumption can increase blood pressure which is a risk factor for kidney damage. Oxidative stress play a role in the kidney damage that induced by ethanol. In this study aims to the description of creatinine levels in moderate and heavy alcohol drinkers in Jalan Mendawai Kota Palangka Raya. This study used the descriptive method to describe the effect of consuming alcohol on kidney function using creatinine level parameters. Total sample used is 20 people with snowballs Sampling technique. The inclusion criteria such as male, age over 20 years old, consumed alcohol more than 5 years, consumed alcohol every day. Creatinine examination was done by Jaffe Reaction method using Photometer 5010 V5 +. The results showed that 15 people (75%) had high creatinine levels and 5 people (25%) had normal creatinine levels.

The Increase in Nutritional Status by Fermented Milk Supplement on Elementary School Children from Fisherman's Village in Bantul, Yogyakarta Province of Indonesia

Abstract: Probiotics drinks, containing Lactobacillus, were rapidly developed because of its benefit to the health. The bacteria reduced the pathogenic microorganism growth such as virus, fungi, and protozoa. The nutritional status is influenced by food intake, immunity and infection. The children of fisherman’s village are included in the insecure nutrition group because of the low social economic status and healthy living behavior. The aim of this research was to know the influence of daily consumption of probiotics in fermented milk to the nutrition status in elementary school children. This research is quasi-experimental with pretest-posttest control group design. Subjects of 95 elementary school children were divided into 2 groups: 62 children as treatment group and 33 children as control group. Determination of nutritional status is based on anthropometry according to CDC 2000 (BMI-age) growth-chart; and the biochemistry parameter consist of the level of serum total protein, albumin, blood urea nitrogen (BUN), urine creatinine and hemoglobin. Determination of serum total protein and BUN were carried out by Microkjeldahl method, hemoglobine by cyanmet hemoglobin method, albumin by dye-binding method, and creatinine level by Jaffe reaction method. The infection status was determined by anamnesis and laboratory examination of feces which was conducted to find the parasite in the stool. Of sixty five ml fermented milk, that contains of 6.5 x 109 Lactobacillus shirota strain, was consumed every day in 37 days. The data was analyzed by Wilcoxon test for nonparametric data and paired T-test for parametric data. The result shows that after the treatment, it increased the nutritional status athropometrically from underweight to normal (12.9%) and overweight to normal (3.23%). In biochemically, it increased the total protein level from 6,111 to 6,705 mg/dL (p=0,001) and decreased the BUN from 42,709 to 41,127 mg/dL (p=0,004) significantly eventhough it was in normal range. The conclusion is that consuming fermented milk for 37 days in children is proven to enhance the nutritional status both by anthropometric and biochemistry parameter. Keywords: probiotic, nutritional status, Lactobacillus, fermented milk supplement

Clinical Laboratory Medicine: An Alliance for the Optimal Management of Acute Kidney Injury with the Use of Biomarkers.

Clinical medicine is practiced in the now. When faced with a patient, we may formulate a treatment plan based on both medical and clinical history; however, therapy is always prescribed prospectively, not retrospectively. This is no more a relevant challenge than when faced with a patient at risk of, or with, acute kidney injury (AKI). This syndrome reflects a broad spectrum of clinical presentations ranging from relatively mild to severe that may result in dysfunction with full recovery, dysfunction with partial recovery, or nonrecovery resulting in severe or permanent loss of renal function that is associated with substantial morbidity, mortality, and costs (1, 2). Despite all the well-documented data supporting this, AKI remains a disorder that is usually underrecognized or recognized late after the damaging event due, in part, to our commonly available diagnostic tools. The first assays for the measurement of creatinine in serum and plasma were published over a century ago, and although the Jaffe reaction using alkaline picrate remains the cornerstone of most currently available routine methods this approach is poorly suited for the acute management of AKI (3). Serum creatinine (SCr) concentration and urine output are functional markers …

Immobilization of cardioprotective drug phosphocreatine on a surface of nanoparticles of silica

In this work silica aminated nanoparticles were used to show capability for chemisorbing organic compound having a carboxyl group. Phosphocreatine (creatine phosphate) was used as an active ingredient. Since the method for determination of phosphocreatine with the sample analysis using Jaffe reaction didn’t give a positive result, the definition of free phosphocreatine was carried out by the method of diacetyl in the presence of α-naphthol.

False acute kidney injury alert due to model car fuel ingestion

We report a case of accidental ingestion of model car fuel (Optifuel) resulting in an apparent elevation of serum creatinine of 274 µmol/L (3.1 mg/dL) as measured by the Jaffe...

O-35 A novel approach in paediatric drug design: the conventional pig as juvenile animal model

BackgroundTo date, the paediatric subpopulation is often neglected during drug development. The main reasons are limited economic profit of drugs adapted to children, ethical concerns for performing paediatric clinical trials...

Correlation of uric acid, urea, ammonia and creatinine of seminal plasma with semen parameters and fertilization rate of infertile couples

Background: Ammonia, urea, uric acid, and creatinine are the major non-protein nitrogenous compounds (NPNs). It is reported that the concentration of NPNs in the seminal plasma of normal and infertile individuals is different and sperm is affected by NPNs. Objectives: The aim of this study was to determine the quantities of ammonia, urea, uric acid, and creatinine in seminal plasma and the correlation of these compounds with the fertilization rate after an intracytoplasmic sperm injection (ICSI). Methods: The levels of ammonia, urea, uric acid, and creatinine were determined in seminal plasma collected from 50 men. The ammonia and urea were determined by L-glutamate dehydrogenase and diacetyl monoxime method, respectively. Uric acid and creatinine were detected by enzymatic method and Jaffe reaction, respectively. The fertilization was evaluated around 16–18 hours post-ICSI on the appearance of 2 pronuclei and 2 polar bodies. The fertilization rate was calculated by the number of fertilized oocytes per the number of oocytes injected. Results: There was a significant negative correlation between seminal ammonia and sperm motility (P<0.05). Urea and creatinine had a negative correlation with respect to the sperm count (P<0.05). In addition, there was an inverse correlation between urea and uric acid of seminal plasma and sperm morphology (P<0.05). A significant negative correlation was found between seminal uric acid and urea with respect to the percentage of the fertilization rate (P<0.05). Conclusions: The findings of the present study showed that urea and uric acid in seminal plasma have a negative impact on the fertilization rate.

Development and characterization of an electrochemical biosensor for creatinine detection in human urine based on functional molecularly imprinted polymer

In this work, sensor based on a new molecularly imprinted polymer (MIP) for creatinine (Cre) detection, using screen-printed gold electrodes (Au-SPE), was developed. A carboxylic polyvinyl chloride (PVC-COOH) layer was first deposited on Au-SPE surface. The creatinine molecules were attached to the surface of Au-SPE/PVC-COOH. Afterward, the polymerization of acrylamide and N, N′ methylenebisacrylamid filled vacant spaces around them. The subsequent templates removal left binding sites within the polymer which are capable of selectively recognizing creatinine at different concentrations. To test the sensitivity of this biosensor, the same procedure without creatinine was performed on a gold non-imprinted polymer (Au-SPE/NIP). Their retention and molecular-recognition properties were qualitatively investigated by means of three instrumental techniques: voltammetry (cyclic voltammetry (CV) and differential pulse voltammetry (DPV)), electrochemical impedance spectroscopy (EIS), and UV–Visible spectrophotometry (UV–Vis). The obtained results indicate that the MIP had a specific recognition ability for creatinine, while other structurally related compounds, such as urea or glucose, could not be recognized on the MIP. In addition, the biosensor was tested on volunteers with different creatinine urine levels and seemed a promising tool for screening creatinine in point-of-care. Moreover, Partial Least Square (PLS) analysis was used to obtain a correlation between the predicted creatinine concentrations from voltammetric measurements and concentrations measured by Jaffe's reaction as a reference method. The EIS and DPV biosensor responses show a limit of detection of 0.016ng/mL and 0.081ng/mL, respectively, with a linear range from 0.1ng/mL to 1μg/mL. This study provides a promising strategy to fabricate sensor devices based on MIP with highly selective recognition ability, simplicity of operation, small size and low cost.

Urine creatinine and anthropometric indices of sportsmen and women

Background: Interpretation of the different aerobic and anaerobic metabolism, training, and anthropometric indices of sportspersons from different sports discipline can aid in improving sports performance. This study sought to evaluate the association between urine creatinine concentration (UCR) and percentage body fat (%BF), body mass index (BMI), and duration of training (DOT) among University of Ghana sportspersons. Methods: A cross-sectional study design was used. Information on background characteristics, body weight, height, %BF, and sporting activity profiles were gathered on a convenient sample of 101 University of Ghana sportsmen and women across all levels of study. BMI and %BF were determined using the Omron Fat Loss Monitor™. Creatinine concentration in 24-h urine samples was analyzed using Jaffe's reaction, and absorbance read spectrophotometrically at 530 nm. Results: Mean age was 22 ± 3 years. Thirty-one percent (31%) of the participants played football, whereas 69% took part in other sports (handball, volleyball, rugby, and baseball). Average daily DOT of 113.6 ± 44 min (males) and 95.1 ± 54 min (females) was reported by the participants. Mean BMI and %BF were 23.1 ± 3.7 Kg/m2 and 23.2 ± 9.0%, respectively. The mean BMI was within normal range as per the WHO standards, whereas %BF exceeded required limits for each sports discipline. UCR was higher for males (1.2 ± 0.5 g/d) as compared to females (0.8 ± 0.5 g/d). There was a weak positive correlation between UCR and BMI (r = 0.123; P = 0.22) and between UCR and DOT (r = 0.074; P = 0.46). %BF and UCR were inversely related (r = −0.114, P = 0.26). There was no association between UCR and type of sports (P = 0.24). There was a significant association between the type of sports and BMI (P = 0.002). Conclusion: There was a weak positive correlation between creatinine and BMI as well as training duration. Type of sports played is a significant predictor of sportspersons' BMI.

Effect of Gestational Age and Birth Weight on Serum Creatinine in the First Week of Newborn Life

ABSTRACT Introduction Serum creatinine concentration in health is essentially a function of muscle mass. We designed a prospective study to know the influence of gestational age and birth weight on creatinine in the first week of life. Materials and methods A total of 218 neonates were enrolled during a 2-year study period (May 2014—April 2016) at Kamineni Hospitals, Hyderabad, India. The study group was categorized based on gestational age [very preterm (VPT), preterm (PT), and term] and birth weight [very low birth weight (VLBW), low birth weight (LBW), and normal birth weight (NBW)]. The serum creatinine was assayed on the day of delivery in the mother and on days 0, 3, 5, and 7 in the neonates. The method of estimation of serum creatinine was by the modified kinetic Jaffe's reaction. Results Serum creatinine was high in the VPT neonates (28—33 weeks of gestational age) and VLBW neonates (<1.5 kg) on day 0. An increase in mean serum creatinine was recorded on day 3 in VPT and VLBW neonates. Mean neonatal serum creatinine in all the subgroups based either on gestational age or birth weight decreased on day 7. Conclusion The serum creatinine in the first week of a newborn should be interpreted cautiously as the kidneys are in the process of maturation. High serum creatinine in neonates with insignificant muscle mass is a reflection of maternal serum creatinine coupled with an immature kidney. How to cite this article Ayyala VL, Devabathina N, Gurappagari P. Effect of Gestational Age and Birth Weight on Serum Creatinine in the First Week of Newborn Life. Indian J Med Biochem 2017;21(2):131-135.

Prediction of Preeclampsia in Early Pregnancy by Estimating the Spot Urinary Albumin/Creatinine Ratio.

To assess whether a spot urinary albumin:creatinine ratio (ACR) measured before 20weeks of gestation can predict subsequent development of preeclampsia. The ACR was determined from midstream urine sample taken between 17 and 20weeks of gestation. Urine albumin was measured by immunoturbidimetric method using commercially available kit (Beckman Coulter) through Beckman AU 480 fully automated biochemistry analyzer. Urine creatinine was measured by modified kinetic Jaffe reaction without deproteinization.[Formula: see text]Participants were then followed until delivery. Primary outcome measure was preeclampsia, secondary outcome measures were gestational hypertension, gestational diabetes mellitus, IUGR, and normal range estimate of urinary albumin-to-creatinine ratio was established. The median spot urinary albumin-to-creatinine ratio measured between 17 and 20weeks of gestation was 5.2mg/g of creatinine (2.5-9.6). Women who subsequently developed preeclampsia had higher spot urinary albumin-to-creatinine ratio (median 30.795 [9.7-92.8]) in comparison with women who developed gestational hypertension (median 5.2 [0.7-7.2]) and unaffected women (median 5.2 [2.5-9.6]). The urinary albumin-to-creatinine ratio of the mother who developed IUGR was significantly higher. By ROC analysis, the optimum ACR to predict preeclampsia was 9.85mg/g of creatinine. The relative risk of developing preeclampsia in women with urinary albumin-to-creatinine ratio more than 9.85mg/g of creatinine was higher than in the women who had urinary albumin-to-creatinine ratio less than 9.85mg/g of creatinine. A spot urinary albumin-to-creatinine ratio of more than 9.8mg/g of creatinine can predict the development of preeclampsia in later pregnancy with the sensitivity and specificity of 67 and 76%, respectively. However, additional studies and cost-benefit analysis are required to confirm these finding before recommending this test for screening purposes.

Picric acid capped silver nanoparticles as a probe for colorimetric sensing of creatinine in human blood and cerebrospinal fluid samples

Creatinine is the most important parameter to be determined in the diagnosis of renal, muscular and thyroid function. The most common method for the determination of creatinine is Jaffe's reaction, a routine practice for blood and urine analysis. However, in cases of icteric and haemolyzed blood samples, interference occurs during the estimation of creatinine by other constituents present in the blood like bilirubin, creatine, and urea, which lead to wrong diagnosis. To overcome such difficulty, we have developed a silver nanoparticle (Ag NPs) based sensor for the selective determination of creatinine. In this study, a new approach has been given to the traditional Jaffe's reaction, by coating Ag NPs with picric acid (PA) to form an assembly that can selectively detect creatinine. The Ag NPs based sensor proficiently and selectively recognizes creatinine due to the ability of picric acid to bind with it and form a complex. The nanoassembly and the interactions were investigated by transmission electron microscopy (TEM), dynamic light scattering (DLS) analysis, UV-Vis spectroscopy, FT-IR spectroscopy and ESI-MS, which demonstrated the binding affinity of creatinine with PA-capped Ag NPs. A linear correlation was obtained in the range of 0.01 μM-1 μM with an R(2) value of 0.9998 and a lower detection limit of 8.4 nM. The sensor was successfully applied to different types of blood and CSF samples for the determination of creatinine, and the results were compared to that of the Jaffe's method. With the advantages of high sensitivity, selectivity and low sample volume, this method is potentially suitable for the on-site monitoring of creatinine.

마이크로 플루이딕 칩을 기반으로 한 크레아티닌 여과장치

매년마다 신장질환으로 고통 받는 사람들이 증가하는 추세이다. 가장 흔한 치료법 중 하나는 혈액 투석인데, 이 방법은 많은 시간이 걸리고, 비용이 많이 드는 방법이다. 이러한 이유 때문에, 인공신장연구의 중요성이 대두되고 있다. 혈액에서 크레아티닌을 여과하는 것은 신장의 주요 기능 중 하나이다. 우리는 이 기능에 초점을 맞춘 새로운 2 채널 마이크로 플루이딕 칩을 고안하였다. 두 개의 PDMS 층을 결합하기 위하여, 아크릴을 가공한 하우징 시스템이 개발하였으며, 이 방법은 여과막을 쉽게 바꿀 수 있다는 이점이 있다. 우리는 알루미늄 양극 산화물(AAO)을 여과막으로 사용하였다. 여과된 용액은 자페반응(Jaffe reation)을 이용하여, 크레아티닌 농도별 흡광도 차이를 분석하였다. 크레아티닌의 양에 대한 표준식을 만들어, 측정한 데이터를 보간하여 여과된 용액의 농도를 확인하였다. 실험을 통하여 유량 및 크레아티닌 농도에 따른 여과율을 얻을 수 있었다.

A novel lab-on-a-chip design by sequential capillary–gravitational valves for urinary creatinine detection

For the first time, instead of the high centrifugal acceleration (or force) by high speed rotation as the driving source that commonly used in the literature, a novel design of capillary–gravitational valves has been developed in a disposable plastic chip by simple control of the balance between capillary and gravitation forces for sequential functions of fluid material delivery, metering and mixing with much less needed power in this study. An integrated lab-on-a-chip (LOC) module with full functions from the sampling to detection for the urinary creatinine measurement has been further tested and verified its use by simply adjusting the LOC tilt angle. The sequential operation can be even operated by hand in the cases of unstable electricity or for regions without AC electric power. Furthermore, the concentration of urinary creatinine was measured by the transmitting optical density (O.D.) change for a Jaffe reaction and calibrated with the coefficient of variations (CV) less than 3.5%. Real urine samples were also tested and showed highly consistent in compare with clinical method.

CREATININA EN LIQUIDO AMNIOTICO

Se han realizado 162 pruebas de creatinina en líquido amniótico, en gestantes normales que concurren al Hospital Militar Central, Lima, en etapas de gestación que van desde las 24 a las 42 semanas. El líquido amniótico ha sido obtenido por omniocentesis abdominal y por vía vagínal. Para el dosaje de la creatinina se ha empleado el método de Follin Wu, basado en la reacción de Jaffe. Se han establecido valores promedios de creatinina en líquido amniótico en los diferentes grupos consignados en los cuadros respectivos, donde se nota que esta substancia va en aumento progresivo a medida que la gestación avanza. Se han efectuado cálculos estadísticos para presentar los resultados de este trabajo.