1.Variation Of The Antibodies Against Noroviruses In Human Milk Between Secretor And Non-secretor Mothers In Two Populations 2.Study On Growth Rate And Correlated Factors Of 238 Very Low Birth Weight Premature Infants

Variation of the antibodies against noroviruses in human milk between secretor and non-secretor mothers in two populationsBACKGROUND: Noroviruses (NVs) are a major cause of acute non-bacterial gastroenteritis worldwide. NVs probably infect humans through binding to histo-blood group antigens (HBGA) as receptors then replicating in the gastrointestinal tract. The soluble receptors(HBGAs) in human milk could protect infants from NVs causing diarrhea. Secretors were reported to be highly associated with infection caused by several NVs strains(like Norwalk Virus and VA387). al,2-fucosyl glycans are only expressed in FUT2 gene positive persons, which are called secretors ,but are not expressed in the non-secretors who lack an active FUT2 allele.OBJECTIVE: To test the difference of sIgA antibody level to 3 NVs strains in human milk between secretor and non-secretor mothers in two populations:2 secretor-binding strains:Norwalk Virus(NV) and VA387,1 both secretor and non-secretor binding strain:VA207.DESIGN/METHODS: Human milk samples from 51 U.S. (Cincinnati, U.S.A.) and 243 Mexican (Mexico City,Mexico) mothers were used in this study. Samples were from two milk banks for two cohort studies:Cincinnati Children's Research Human Milk Bank and a study funded by the national Institute of Child Health and Human Development of Mexico, entitled "The Role of Human Milk in Infant Nutrition and Health".Enzyme immune assay (EIA) was used for phenotyping of HBGAs and detection of sIgA antibody to secretor-binding NVs (Norwalk Virus and VA387) and a secretor and non-secretor-binding NVs (VA207). Non-secretor mothers were defined by lack of secretor HBGAs (Le^b, Le^y, and H antigens) in their milk. Recombinant virus-like particles were used for antibody detection. Difference of the level of sIgA antibody to the 3 types of NVs between nonsecretors and secretors was tested by ANOVA, p<0.05 was considered as significant.RESULTS: Of the mothers studied, 20 (39%) U.S. mothers and 4 (2%) Mexican mothers were identified as non-secretors; the rest were identified as secretors. Of the 294 milk samples, non-secretor(24 mothers) milk contained significantly lower sIgA antibody to the 3 NVs strains than secretor(270 mothers) milk(anti-NV sIgA: 0.018 vs0.077, p<0.01; anti-VA387 sIgA:0.019 vs0.143, p<0.01; anti-VA207sIgA: 0.053 vs 0.102, p<0.01) . Non-secretor milk contained significantly lower sIgA to secretor-binding NVs strains than secretor milk in each population (anti-Norwalk Virus sIgA - US:0.015 vs 0.032, p<0.05; Mexico: 0.024 vs 0.089, p<0.05. Anti-VA387 sIgA -US: 0.016 vs .066, p<0.01; Mexico: .040 vs .146, p<0.05). As expected, non-secretor and secretor milk did not differ in medium sIgA level to strain VA207 in either the U.S. or Mexican mothers (US: 0.0395 vs0.069, p>0.05; Mexico: 0.107 vs0 .113, p>0.05) .CONCLUSIONS: The milk of non-secretor mothers showed significantly lower prevelance of sIgA antibody to main secretor-binding strains of NVs compared to the milk of secretor mothers.This result is consistent with formerly reported binding patter of major NVs strains with HBGAs. The lack of milk protection of secretor infants from their non-secretor mothers by either innate (soluble HBGA receptors) or acquired immune factors highlights significance of clinical care of such secretor infants while faced with NVs. Study on growth rate and correlated factors of 238 very low birthweight premature infantsObjective Each year about 1 million premature babies are born in China.Study on the growth of such babies especially those born as very low birth weight infants still lacks.The oblective of this study was to investigate the nutrition support and growth rate of very low birth weight (VLBW) premature infants during hospital stay.Methods Clinical data of VLBW premature infants discharged from Jan.1^st,2005 to Jun. 30^th,2006 were collected retrospectively according to certain criteria from 10 tertiary NICUs in China. Nutrition support, growth pattern and factors associated with growth rates were studied.Criteria for inclusion: gestational age <37weeks;hospitalized in 12 hours after birth;NICU stay for≥14 days;discharged from the same hospital with full enteral feeding,good weight gain and stable vital sign. Criteria for exclusion:having congenital malformation or metabolic diseases that might influence growth;having received surgical course during hospital stay;died or discharged with unstable vital.Results Two hundred and thirty-eight VLBW premature infants were included in this study. Mean gestational age at birth was (30.9±1.9) w, mean bith weight was(1313±129) g. The growth rate from the 1^st week to the 6th week during hospital stay was -7.2g/kg.d, 14.2 g/kg.d, 13.6g/kg.d, 13.7g/kg.d, 14.2g/kg.d and 14.8g/kg.d respectively.Enteral feeding was started at (3.4±2.3) days of life,parenteral nutrtion was given at (3.1±1.7) days of life,total energy intake of 120kcal/kg.d was achieved at (21.3±11.6)d, enteral feeding reached 150ml/kg.d at (23.4±10.8) d. The average hospital stay was (39.8±13.9)days.The average growth rate after regaining to birth weight was(13.8±3.5) g/kg.d, infants born as small for gestational age showed higher growth rate than those born as appropriate for gestational age (24.00vs. 21.50 g/kg.d, Z=-2.325, p<0.05) .lower birth weight (1273 vs. 1334g, x²=15.765, p<0.001) , more infants born as SGA(51.6%vs.37.3%, x²=4.432,p=0.035) ,earlier starting of enteral feeding (3 vs.4d, Z=-2.290, p=0.022)) was associated with better growth rate (≥15g/kg.d) .Conclusions Most VLBW premature infants failed to achive growth rate of≥15g/kg.d as desired for normal intrauterine growth rate. Earlier enteral and parenteral nutrition might be good for the growth of VLBW premature infants.