RESUMO
The case mortality for severe malnutrition in childhood remains high, but established best approaches to treatment are not used in practice. The energy and protein content of the diet at different stages of treatment appears important, but remains controversial. The effect on growth, urea kinetics and the urinary excretion of 5-L-oxoproline was compared between a standard infant formula (HP group) provided in different quantities at each stage of treatment and a recommended dietary regimen, which differentiates the requirements of protein and energy during the acute phase of resuscitation (maintenance intake of energy and protein, relatively low protein to energy ratio, LP group) from those during the restoration of a weight deficit (energy and nutrient dense). The energy required to maintain weight was less in the HP than the LP group, but the HP group was not able to achieve as high an energy intake during repletion of wasting because of the high volume which would have had to be consumed. Compared to the LP group, in the HP group during catch-up growth there was significantly greater deposition of lean tissue and higher rates of urea production, hydrolysis and salvage of urea-nitrogen. These, together with higher rates of 5-L-oxoprolinuria, suggest a greater constraint of the formation of adequate amounts of nonessential amino acids, especially glycine, in the face of enhanced demands. Although more effective rehabilitation might be achieved using a standard formula, there is the need to determine the extent to which it might impose metabolic stress compared with the modified formulation.
Assuntos
Proteínas Alimentares/administração & dosagem , Crescimento , Kwashiorkor/fisiopatologia , Desnutrição Proteico-Calórica/fisiopatologia , Ureia/metabolismo , Dieta , Ingestão de Energia , Humanos , Hidrólise , Lactente , Alimentos Infantis , Cinética , Kwashiorkor/dietoterapia , Masculino , Nitrogênio/metabolismo , Desnutrição Proteico-Calórica/dietoterapia , Ácido Pirrolidonocarboxílico/urina , Ureia/urina , Aumento de PesoRESUMO
The demand for glycine to satisfy normal growth during early life is considerable and most has to be made endogenously. The extent to which adequate glycine is available can be assessed by measuring the urinary excretion of 5-L-oxoproline. The excretion of 5-L-oxoproline at 6 weeks of age for infants in Trinidad of African, Indian or mixed parentage (398 mumol/mmol creatinine) was significantly greater than for infants born in England of Caucasian parentage (194 mumol/mmol creatinine). There was no relationship between 5-L-oxoproline excretion and either sex or pattern of feeding. There were significant inverse relationships between 5-L-oxoproline/creatinine and birth weight, and head circumference either at birth or 6 weeks of age, suggesting that limited availability of glycine is associated with poorer growth before and after birth. For a group of infants born in England of Indian parentage, excretion of 5-L-oxoproline (155 mumol/mmol creatinine) was not different to infants of Caucasian parentage, but significantly less than infants born in Trinidad. The demonstration that 5-L-oxoproline/creatinine was similar in infants born in England, regardless of parentage, shows that the differences between England and Trinidad are related to environment and are unlikely to be accounted for by genetic differences or ethnicity.
Assuntos
Glicina/metabolismo , Crescimento/fisiologia , Ácido Pirrolidonocarboxílico/urina , África/etnologia , Biomarcadores/urina , Creatinina/urina , Inglaterra , Humanos , Índia/etnologia , Lactente , Trinidad e TobagoRESUMO
OBJECTIVE: To determine the pattern of excretion in urine of 5-L-oxoproline, as a measure of glycine status, during the first six weeks of life in Jamaican infants. DESIGN: Spot samples of urine were collected from term and preterm infants at birth and longitudinally to four weeks of age, or at six weeks of age. 5-L-oxoproline was isolated by column chromatography and hydrolysed to L-glutamic acid, which was measured enzymatically and the results expressed relative to creatinine excretion. SETTING: Maternity wards and postnatal clinic of the University Hospital of the West Indies. SUBJECTS: African-Caribbean infants, 19 term and 21 preterm, from birth to four weeks of age, and 79 term infants at six weeks of age. RESULTS: There were no differences between term and preterm infants. Excretion of 5-L-oxoproline increased progressively from birth, 141 mumol/mmol creatinine, to 270 mumol/mmol creatinine at four weeks of age. At six weeks of age, excretion was significantly greater than at birth or four weeks of age, 525 mumol/mmol creatinine. Compared with infants born in England, the excretion of 5-L-oxoproline was not different at birth, but was significantly greater in Jamaican infants at six weeks of age. CONCLUSIONS: Glycine status, indicated by increased excretion of 5-L-oxoproline, is marginal in Jamaican infants at six weeks of age, and this possibly reflects a limitation in the endogenous biosynthesis of glycine due to a dietary limitation of folate or vitamin B-12.
Assuntos
Creatinina/urina , Recém-Nascido/urina , Recém-Nascido Prematuro/urina , Ácido Pirrolidonocarboxílico/urina , Cromatografia , Creatinina/metabolismo , Inglaterra , Feminino , Glicina/biossíntese , Humanos , Lactente , Recém-Nascido Prematuro/metabolismo , Jamaica , MasculinoRESUMO
OBJECTIVE: We have measured urea kinetics in normal adult men and women of different body composition to determine whether adiposity is associated with differences in the rate of urea production or endogenous urea hydrolysis. DESIGN: Urea kinetics were determined from the excretion of [15N15N]urea in urine over a period of 48 h following a single oral dose of [15N15N]urea, in nine lean and nine obese women and in seven light and seven heavy males while they were consuming their habitual diets. Urinary 5-L-oxoproline was measured as an index of glycine metabolic status. SETTING: The studies were carried out in the research ward of the Tropical Metabolism Research Unit, University of the West Indies. RESULTS: Successful studies were completed in eight obese and five lean women and in six heavy and five light men. When compared with lean women, in obese women the rate of urea production and hydrolysis was significantly greater and this difference could not be accounted for by the greater fat-free mass alone, and was in part associated directly with the increase in fat mass. The rate of urea production and hydrolysis was greater in heavy men than in light men, a difference which was attributed to an increase in dietary protein. In obese women and heavy men there was a significantly higher rate of excretion of 5-L-oxoproline in urine when compared with lean women and lean men respectively. CONCLUSION: This paper highlights the difficulty in identifying an appropriate reference with which to express results in people of different body composition. In obese women urea production and the hydrolysis of urea are increased, in part related to the increased fat-free mass, but also related to the increased fat mass itself. In obese women and men on high protein diets the greater rate of hydrolysis urea may be a reflection of an increased demand for the synthesis of non-essential amino acids, especially glycine.
Assuntos
Composição Corporal , Proteínas Alimentares/administração & dosagem , Obesidade/metabolismo , Ureia/urina , Adulto , Índice de Massa Corporal , Feminino , Humanos , Hidrólise , Jamaica , Cinética , Masculino , Nitrogênio/urina , Isótopos de Nitrogênio , Ácido Pirrolidonocarboxílico/urina , Ureia/metabolismoRESUMO
Urinary 5-L-oxoproline was measured during normal pregnancies in Southampton, England and Kingston, Jamaica. The CV of 5-L-oxoproline excretion in urine, determined over 7 d in a non-pregnant woman and three pregnant women, was 10-36%. Compared with non-pregnant women, urinary 5-L-oxoproline increased three to four times from early pregnancy in women in Southampton, a highly significant difference, and remained elevated at similar levels during mid and late pregnancy. For women in Kingston, the excretion of 5-L-oxoproline was similar to that of Southampton women in the non-pregnant group and during early pregnancy. However, there was a progressive increase in the excretion of 5-L-oxoproline as pregnancy advanced and by late pregnancy excretion was from three to ten times greater than the average for the non-pregnant women. There was a significant difference between the women in Southampton and the women in Kingston during mid and late pregnancy, with women in Kingston excreting twice as much 5-L-oxoproline during late pregnancy. If the excretion of 5-L-oxoproline is a measure of glycine insufficiency, the results would indicate that in some pregnancies the ability of the mother to provide glycine for herself and the developing fetus is marginal or inadequate and the constraint appears more marked in Jamaica than in England.
Assuntos
Gravidez/urina , Ácido Pirrolidonocarboxílico/urina , Adulto , Estudos Transversais , Inglaterra , Feminino , Glicina/metabolismo , Humanos , Jamaica , Estudos Longitudinais , Gravidez/metabolismo , Segundo Trimestre da Gravidez , Terceiro Trimestre da GravidezRESUMO
Urea kinetics were measured non-invasively in 12 Chilean schoolboys aged 8-10 years who were receiving one of two diets, either predominantly animal protein or predominantly vegetable protein. Both the diets provided an equivalent level of gross protein, 1.2 g/kg/day. The study diets were given for 10 days to enable adaptation to take place. On the eighth day a single oral dose of 15N15N-urea, 100 mg, was given and the amount of label excreted as 15N15-urea in urine over the subsequent 48 hours was measured. There was little difference in any aspect of urea kinetics between the two diets with urea production (animal, 173 +/- 50 mgN/kg/day; vegetable 179 +/- 53 mgN/kg/day), urea excretion (animal, 86 +/- 19 mgN/kg/day; vegetable, 105 +/- 13 mgN/kg/day), urea nitrogen hydrolysis (animal, 87 +/- 49 mgN/kg/day; vegetable, 74 +/- 42 mgN/kg/day), and the salvaged urea-nitrogen derived from hydrolysis which returned to urea formation (animal, 12 +/- 5 mgN/kg/day; vegetable, 17 +/- 9 mgN/kg/day) all being similar. A very high proportion of the salvage nitrogen derived from urea hydrolysis was maintained within the metabolic pool, about 80%, which was equivalent to 0.4 g protein/kg/day. This is the first time urea kinetics have been measured in children of this age and shows that 57% of the ura produced is excreted in urine on average with about 43% of the urea-nitrogen being salvaged for further metabolic interaction. It is concluded that the vegetable based protein diet taken habitually by Chilean children is metabolically equivalent in terms of urea kinetics to a diet based upon animal protein at this level of intake, but that high rates of salvage of urea nitrogen are found on both diets.
Assuntos
Envelhecimento/metabolismo , Proteínas Alimentares/normas , Ureia/farmacocinética , Nitrogênio da Ureia Sanguínea , Estatura/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Criança , Chile , Proteínas Alimentares/farmacologia , Humanos , Hidrólise , Masculino , Nitrogênio/metabolismo , Nitrogênio/urina , Puberdade/metabolismo , Dobras Cutâneas , Ureia/urinaRESUMO
The pattern of aggregate nitrogen demand during pregnancy and the fetal and maternal components are unclear. Excess demand enhances efficiency of nitrogen utilization. Urea salvage contributes to enhanced efficiency. Dietary protein intake, urea production, and salvage of urea nitrogen were measured in eight nonpregnant control subjects, and trimesterly in nine pregnant women. Production was measured after prime-intermittent intravenous doses of [15N 15N]-urea by dilution of label in urinary urea. Dietary protein intake was greater in trimester 1 than in nonpregnant women (167 +/- 36 vs 224 +/- 60 mg N.kg-1.d-1), and increased further in trimester 2 (266 +/- 59 mg N.kg-1.d-1). Urea production was not higher during pregnancy. Despite higher protein intake, urea salvage was higher in pregnancy (40 +/- 24 nonpregnant vs 77 +/- 23, 61 +/- 31, and 51 +/- 12 mg N.kg-1.d-1). Therefore, the demand-supply gap for nitrogen was greatest early in pregnancy when fetoplacental growth is slowest, and implies heightened maternal demand.
Assuntos
Proteínas Alimentares/metabolismo , Nitrogênio/metabolismo , Gravidez/metabolismo , Ureia/metabolismo , Adulto , Proteínas Alimentares/administração & dosagem , Feminino , Humanos , Jamaica , Cinética , Estudos Longitudinais , Necessidades NutricionaisRESUMO
The fate of a dietary supplement, high energy supplement (HES), was studied in 16 households of moderately malnourished children (7-32 months-of-age) attending a nutrition clinic in the slums of Kingston. Two methods were used in the study: observation of the consumption of the HES and a urine collection from all household members (on three occasions) to analyse the presence of D-Xylose, a tracer mixed in the HES. Households were observed during eight (8) four-hour periods by community health workers. The results showed that 60 percent of both adults and non-index children had positive urine results for xylose. However, adults were observed less often than the non-index children to consume the supplement (23 percent and 50 percent respectively). More children of large households (more than 6 members) consumed HES than those from small households. Both methods showed that sharing occurred during dietary supplementation. High energy supplements used in rehabilitation of malnourished children in this study are frequently shared by house-hold members; hence the index child will not receive sufficient nutrients required for full catch-up growth. This experience has led the public health service to focus more on fortifying existing menus in the households of malnourished children (AU)
Assuntos
Humanos , Lactente , Pré-Escolar , Transtornos da Nutrição Infantil/dietoterapia , Metabolismo Energético , Alimentos Fortificados , Transtornos da Nutrição do Lactente/dietoterapia , Jamaica , XiloseRESUMO
The urinary excretion of 5-oxoproline, which may be used as an index of glycine status, was investigated in 30 normal pregnant women during different stages of pregnancy and in 18 non-pregnant female volunteers. During an 18-h study there was little variation in the 5-oxoproline/creatinine index, and a single sample gave a representative value. The excretion of 5-oxoproline/creatinine (mumol/mmol) rose progressively as pregnancy advanced (non-pregnant mean 10, SD 5, first trimester mean 46, SD 12, second trimester mean 150, SD 180, and third trimester mean 280, SD 320) and by the third trimester was over 20 times greater than in non-pregnant women. The data suggest that as pregnancy advances the endogenous production of glycine may be insufficient to satisfy the increasing demands.
Assuntos
Glicina/metabolismo , Gravidez/urina , Pirrolidinonas/urina , Ácido Pirrolidonocarboxílico/urina , Feminino , Humanos , Gravidez/metabolismo , Segundo Trimestre da Gravidez , Terceiro Trimestre da Gravidez , Fatores de TempoRESUMO
1. The evidence is accumulating to suggest that glycine, the simplest amino acid, is conditionally essential in man. Benzoic acid, by conjugation with glycine to form hippuric acid, is known to deplete the free glycine pool of the body. Glycine is one substrate for the enzyme glutathione synthase (EC 6.3.2.3) and in the inborn error of metabolism in which glutathione synthase function is defective, increased quantities of 5-oxoproline are excreted in the urine. 2. An oral dose of 4-10 g sodium benzoate was given to six normal adults to deplete the metabolic pool of glycine, and the urinary excretion of 5-oxoproline was followed for 6 h. In five of the six, a significant increase in the urinary 5-oxoproline was seen within 3 h. 3. These findings show that 5-oxoprolinuria can result from limited glycine availability, and may provide a useful test for assessing glycine sufficiency in a range of physiological and pathological states.
Assuntos
Glicina/metabolismo , Pirrolidinonas/urina , Ácido Pirrolidonocarboxílico/urina , Adulto , Benzoatos/farmacologia , Ácido Benzoico , Feminino , Glicina/farmacologia , Hipuratos/urina , Humanos , MasculinoRESUMO
A cross-sectional study was carried out among 18 Jamaican pregnant women divided into three groups of 6 subjects according to the stage of pregnancy: group B, 12 weeks, group C, 24 weeks and group D, 33 weeks. A group (group A) of 6 non-pregnant women was selected as control. The rate of whole-body protein turnover was measured by continuous oral administration of 15N-glycine and the resting metabolic rate by the open-circuit method. All subjects had a normal pregnancy outcome. The composition of the diet on the day of the study was comparable between the four groups (approximately 80 g protein and 9.45 MJ energy) and not significantly different from the composition of the diet during the 2 d prior to the experiment. The rates of protein synthesis and breakdown were higher in groups B and C compared to group A and lower in group D where they reached values slightly higher than in group A. Estimated from urea enrichment, these rates did not vary significantly among the groups, while estimated from ammonia enrichment the difference was significant (P less than 0.05) and there was a negative correlation between the gestational age and the rate of synthesis (r = -0.63) and breakdown (r = -0.69). Nitrogen retention was comparable between the three groups of pregnant women and significantly higher than in the group A. The resting metabolic rate was similar between the groups of pregnant women. These results suggest that the rates of protein turnover observed during gestation reflect more the changes that occur in maternal than those in fetal tissues. The values for protein synthesis and nitrogen retention indicate that the amount of protein deposited during pregnancy is greater than that expected on the basis of body composition analysis. It is also suggested that as pregnancy proceeds whole-body protein turnover represents a smaller part of the resting metabolic rate.
Assuntos
Gravidez , Proteínas/metabolismo , Adulto , Metabolismo Basal , Estatura , Peso Corporal , Estudos Transversais , Ingestão de Energia , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Jamaica , Nitrogênio/metabolismo , Nitrogênio/urinaRESUMO
The practice of treating females with vaginal discharges and other pelvic symptoms, on the basis of a presumptive diagnosis of "Clinical gonorrhoea" without attempting to obtain adequate laboratory tests for N. Gonorrhoea, T. Vaginalis and C. Albican in female patients. All of whom had reported to a V. D. Clinic, (some because they were reported as contacts of male gonorrhoea patients), and who had been selected for penicillin treatment. All had vaginal discharges and other evidence of genital disease. The study was carried out at the Comphrensive Health Centre in Kingston, Jamaica. Tests for Gonorrhoea included cervical and vaginal gram-stained smears and cervical cultures. Due to shortages of media and personnel, cultures for the comparison of smear and cultures involved, for about half of the female studied, a single Transgrow bottle culture from the cervix and for the other half a Transgrow bottle culture and also a small (5.5cm) Thayer-Martin plate. Other patients had a rectal culture on a small Thayer-Martin plate also. These were included not alo in the comparison of results with overall tests for N. Gonorrhoea, E. Baginalis and C. Albicans. Transgrow cultures were incubated immediately. Tests for T. Vaginalis included wet preparations and cultures on "Trichomonas medium". Tests for C. Albicans involved cultures on Sabouraud's agar with yeast identified as C. Albicans by the germination test as described by Taschdjian and associates. A total of 107 or 45.9 percent of 233 females had positive tests for gonorrhoea. (In three of these the test were doubtful). 104 or 44.6 percent had positive tests for T. Vaginalis; 72 or 30.9 percent had positive tests for C. Albicans. Overall, 187 patients or 80.2 percent were positive (or doubtful) to one or more tests and 46 or 19.8 percent were negative to all three. Patients with mixed infections were: N. gonorrhoea + T. Vaginalis - 15.4 percent, n. gonorrhoea + C. Albicans - 7.3 percent, N. gonorrhoea + C. Albicans T. Vaginalis - 6.4 percent, T. Vaginalis + C. Albicans - 5.6 percent. Of 92 or 41.8 percent of a total of 220 females studied, and who were positive or doubtful, only 40 or 18.2 percent of the total had positive or doubtful smears, while 52 or 23.6 percent of the total had only positive cultures. The latter would have been missed had smears alone been done. (i.e. 56.5 percent of cases). Of 94 or 44.3 percent of 212 females studied by T-M and Transgrow media, 76 had both tests positive. A total of 18 had one test positive, 7 with Transgrow and 11 with T-M. Of 104 patients who had both rectal and cervical cultures, 8 or 7.7 percent had only the rectal culture positive. There were 23 positive rectal cultures compared with 51 cervical positives out of a total of 59 with positive cultures. Of 140 patients with Trichomonal infestation, 107 had positive wet preparations while 114 had positive cultures. The advantage of culture over wet preparation is therefore but slight. It is clear that smears are inadeqate as anything more than supplementary diagnostic aids and that cultures for gonorrhoea are absolutely essential in the diagnosis of gonorrhoea in the female. Rectal cultures were found to add substantial increase (15.7 percent) to the number of positive cases when used in conjunction with cervical cultures. This must be clear to all physicians and cultures made available for their use(AU)