Human Milk Lipid Profiles around the World: A Systematic Review and Meta-Analysis.

Reported breast milk lipid concentrations may vary with geographical region, postnatal age, and year of sample collection. In this review, we summarized data on the concentrations of total fat, total phospholipids, cholesterol, and fatty acids in human milk worldwide and their variation according to lactation stage, study area, and sample collection year. A systematic literature search was performed using the PubMed, Embase, Web of Science, and Medline databases for English-language papers and Wanfang and China National Knowledge Infrastructure databases for Chinese-language papers. A total of 186 studies evaluating the human milk lipid profiles were included. According to random-effects models based on worldwide data, the summarized means (95% CIs) as percentages of total fat were 42.2% (41.1%, 43.3%) for SFAs, 36.6% (35.6%, 37.5%) for MUFAs, and 21.0% (19.3%, 22.7%) for PUFAs. However, the study heterogeneity was high for most types of fatty acids (I2 > 99%). Human milk from Western countries had higher concentrations of MUFAs and 18:1n-9 (ω-9), but lower concentrations of PUFAs, 18:2n-6, 20:4n-6, 18:3n-3, 20:5n-3, 22:6n-3, and total n-6 PUFA compared with those from non-Western countries (P < 0.001-0.011). Significant lactation stage differences were observed for total fat and some individual fatty acids. The concentrations of SFAs and 16:0 were significantly negatively correlated with sampling year (P < 0.001-0.028). In contrast, a significant positive correlation between the concentrations of 18:2n-6 and 18:3n-3 and sampling year was observed (P < 0.001-0.035). Our results suggest that the pooling of data on human milk lipid profiles in different studies should be done with caution due to the high between-study heterogeneity. The concentration of lipids, including total fat, cholesterol, and specific fatty acids, differs in human milk according to lactation stage, geographical region, and year of sample collection.

Quartz crystal microbalance for the detection of carbaryl using molecularly imprinted polymers as recognition element.

A new piezoelectric quartz crystal sensor using molecularly imprinted polymers (MIPs) as recognition element has been prepared for the fast detection of carbaryl. The MIPs were prepared by precipitation polymerization in ACN, and then the polymer particles were fixed on the surface of the electrode. Computer simulation technology was employed to investigate the interaction between carbaryl and methacrylic acid (MAA) for elucidating the recognition mechanism. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were employed to evaluate the obtained imprinted polymer particles and the MIP sensitive film coated on the electrode. The sensor developed exhibits a liner relationship between the frequency shift and carbaryl concentration in the range of 10-1000 ng/mL (y = 0.139 x + 2.99, r = 0.9981), and the detection limit was 12.5 ng/mL (S/N = 3). Furthermore, the influencing factors were investigated, and the experiments indicated that the obtained sensor has high sensitivity, excellent selectivity, good reproducibility, and reusable property.

[Cloning and characterization of geranylgeranyl diphosphate synthase gene of Salvia miltiorrhia].

OBJECTIVE: To obtain geranylgeranyl diphosphate synthase gene of Salvia miltiorrhiza, and conduct bioinformatic and transcript expression analysis of the cloned SmGGPS1 gene. METHOD: The degenerate primers were designed based on the conservative regions of GGPS protein sequences from public databases. The target gene was obtained from root of S. miltiorrhiza by use of homologous cDNA amplification and RACE technologies. The sequence alignment was performed using BLAST. The open reading frame was identified by use of the ORF Finder. The protein domains were defined by use of Prosite software and the signal peptide sequence was predicted by Target P1.1. MEGA4.0 was used to conduct multiple amino acid sequence alignment and construct the phylogenetic tree. Roots and leaves at the seedlings stage and roots, stems, leaves, buds and flowers in the flowering stage were sampled for transcript analysis. Semi-quantitative RT-PCR was used to detect the gene expression level. The complete gene of GGPS was obtained from S. miltiorrhiza genomic DNA by PCR using the cDNA-derived specific primer. The gene structure of GGPS was analyzed by comparison of the genomic DNA and its cDNA. RESULT: The obtained 1 298 bp SmGGPS1 cDNA sequence contains an 1095 bp ORF, encoding 364 amino acids. It is predicted that it has a plastid targeting signal peptide of approximately 52 amino acid at the N-terminal end. It is to believe that this is the polyprenyl synthetase signature, and nucleic acid sequence comparison revealed that SmGGPS1 ORF has more than 60% identity to the reported GGPS. RT-PCR semi-quantitative analysis showed that the gene expresses in the all tested tissues, and with much higher level of expression in the leaves in the flowering stage. SmGGPS1 has a 397 bp intron. CONCLUSION: For the first time the cloning of geranylgeranyl diphosphate synthase gene from S. miltiorrhiza was reported, and it provides a good basis for further functional study of SmGGPS1.

Quantitative determination of quinocetone and its metabolites in chicken plasma by liquid chromatography/tandem mass spectrometry.

A new method has been established for the simultaneous determination of the new veterinary drug quinocetone (3-methyl-2-cinnamoyl-N-1,4-dioxyquioxaline; QTN) and its 2 metabolites de-monoxy-quinocetone (3-methyl-2-cinnamoyl-N-1-monoxyquinoxaline; DMO-QTN) and de-dioxy-quinocetone (3-methyl-2-cinnamoyl-N-quinoxaline; DDI-QTN) in chicken plasma by liquid chromatography/tandem mass spectrometry (LC/MS/MS). The detection was performed using electrospray ionization in multiple reaction monitoring mode. The analysis of the linearity, accuracy, and precision of the method is described. The limits of detection and quantification of the LC/MS/MS method used for testing QTN, DMO-QTN, and DDI-QTN were 0.002 and 0.008 microg/mL; 0.002 and 0.008 microg/mL; and 0.003 and 0.010 microg/mL, respectively. The method was validated and can be used in future pharmacokinetic studies.

[Effect of green tea polyphenols on behavioral performances in psychological stress rats].

OBJECTIVE: This study was conducted to explore the effects of green tea polyphenols modulation on changes of behavioral performances in psychological stress rats. METHODS: The animal model of psychological stress was developed by restraint stress for 3 weeks. Wistar rats were randomly assigned to five groups as follows: control group (CT), stress control group (SCT), and three stress groups with low, medium and high-doses of green tea polyphenols modulation respectively (SLG, SMG and SHG). The changes of behavioral performances were examined by open-field test, water maze and step-through test. Serum levels of cortisol, catecholamines, interleukin-6 and interleukin-2 were also detected. RESULTS: The levels of serum cortisol were all increased obviously in the four stress groups. Furthermore, serum cortisol levels in SMG and SHG were decreased than that of SCT. The behavioral performances of SCT rats in open-field test, step-through test and water maze were all changed evidently in contrast to that of CT rats. On the one hand, the changes of behavioral performances in SLG rats were similar to SCT rats. On the other hand, these changes were improved in SMG and SHG rats. In addition, compared with CT group, the levels of plasma IL-6 and IL-1 were increased clearly in the four stress groups, and the contents of serum norepinephrine and dopamine in SCT and SLG groups were decreased dramatically. The serum norepinephrine and dopamine levels in SMG and SHG rats were increased in contrast to that of SCT rats. CONCLUSION: Our results suggested that psychological stress can impair body' s behavioral performances, and moderate green tea polyphenols modulation may improve these abnormal changes.

Effects of zinc on the induction of metallothionein isoforms in hippocampus in stress rats.

Metallothioneins (MTs) are involved in the cellular metabolism of zinc and in cytoprotection against stress factors. Hippocampus plays a specific role in the body's response to stressors. The present study was conducted to evaluate the effects of zinc on the expression of metallothionein isoforms in the hippocampus of stress rats. The animal model of psychologic stress was developed by restraint for 4 weeks. Wistar rats were randomly assigned to 6 groups: control group, zinc-deficient group, zinc-supplemented group, and the corresponding 3 stress groups. Three separate diets of different zinc contents (1.73 ppm, 17.7 ppm, and 41.4 ppm, respectively) were used in this study. Compared with the control group, the stress groups had higher inductions of MTs and MT-1 and MT-3 mRNA in hippocampus. On the one hand, the expressions of MTs and their mRNAs in hippocampus were downregulated in the zinc-deficient group; however, their expressions were evidently enhanced in the stress zinc-deficient group. MT induction in the zinc-supplemented group was increased. Furthermore, the stress zinc-supplemented group had a more significant yield of MTs and their mRNAs. In addition, the levels of plasma cortisol, interleukin-6 (IL-6), IL-1, and nitric oxide (NO) were increased clearly in the zinc-deficient group and the stress groups. The results suggest that zinc deficiency may decrease and zinc supplementation may increase the expressions of MTs and their mRNAs in hippocampus; moreover, stress can increase their expressions dramatically. The impairment of stress on the body may be involved with the nutrition status of zinc, and zinc deficiency can lower the body's adaptability to stress.

[Effects of zinc on the expression of metallothionein isoforms in hippocampus of stressed rats].

OBJECTIVE: This study was conducted to evaluate the effects of different doses of zinc on the expression of metallothionein isoforms in hippocampus of stressed rats. METHODS: The animal model of psychological stress was developed by restraint stress for four weeks. Wistar rats were randomly assigned to eight groups as follows: control group, zinc deficiency group, pair-feed group, zinc complementarity group and their corresponding stressed groups. RESULTS: In zinc deficiency group, plasm zinc content was decreased, while in zinc complementarity group it's slightly increased. On the one hand, the expressions of metallothionein in brain and MT-1 mRNA, MT-3 mRNA in hippocampus were downregulated in zinc deficiency group, however, their expressions were evidently enhanced in stressed zinc deficiency group. On the other hand, inductions of metallothionein and it' s mRNAs in zinc complementarity group were increased, furthermore, stressed zinc complementarity group has more significantly yield of metallothionein and it' s mRNAs. In addition, the levels of plasma cortisol, IL-6, IL-1 and NO were increased clearly in zinc deficiency group and stressed zinc deficiency group. CONCLUSION: Our results suggested that zinc deficiency may decrease while zinc complementarity increase the expressions of metallothionein in brain and MT-1 mRNA, MT-3 mRNA in hippocampus, moreover, stress can increased their expressions dramatically. The impairment of stress on body may be involved with the nutrition status of zinc, and zinc deficiency can lower the body's resistibility to stress.

[Progress of molecular imprinting technique on the determination of pesticides residues].

People have paid a more attention to the pesticides residues, so the rapid detection method is required. In this paper the application of molecular imprinting technique on the detection of pesticides residues was reviewed, including recognition principles, preparation, current applications, problems and its future.

[Effect of zinc on the corticosterone-induced injury of primary cultured rat hippocampal neurons].

The effect of zinc on the damage of primary cultured hippocampal neurons induced by corticosterone (CORT) was studied. Neuronal injury and expression of NMDA receptor subunits (NR1,NR2A,NR2B) mRNA were detected by using in situ staining and RT-PCR, respectively. Neurons treated with 5 micromol/L CORT for 24 h showed decreased survival rates and increased apoptotic rates compared with the controls; co-application of CORT and 10 or 100 micromol/L Zn(2+) attenuated apoptotic rates while 250 micromol/L Zn(2+) worsened CORT-induced neuronal injury. Expression of NR1, NR2B mRNA in neurons treated by 5 micromol/L CORT for 24 h was significantly increased, while those concurrently added with 10 or 100 micromol/L Zn(2+) showed no changes. No statistic difference in NR2A mRNA was obtained under any treatment. These results suggest that zinc can bilaterally regulate neuronal injuries induced by CORT, among while NMDA receptors probably play an important role.

[Effects of zinc deficiency on bone mineralization and its mechanism in rats].

OBJECTIVE: To study the influence of zinc deficiency on bone mineralization. METHODS: Thirty Wistar rats were randomly divided into three groups with ten in each group, i.e., zinc-deficient group (ZD), control group, and pair-fed group. Histomorphological changes of bone mineralization, bone mineral content and bone density, bone contents of zinc, calcium, phosphorus, magnesium, manganese, copper and hydroxyproline, and serum levels of parathyroid hormone, calcitonin and osteocalcin in the rats were measured. RESULTS: The results showed that the mineral deposit rate and bone contents of zinc, phosphorus and hydroxyproline, and serum levels of calcitonin and osteocalcin lowered significantly in ZD group, as compared with those in the control and pair-fed groups, with (3.26 +/- 0.34) micro m/d, (64.54 +/- 2.34) g/kg, (54.4 +/- 9.5) mg/kg, (9.28 +/- 1.62) g/kg, (41.2 +/- 13.5) micro g/L, (82 +/- 30) micro g/L in ZD group; (5.37 +/- 0.53) micro m/d, (69.01 +/- 4.05) g/kg, (117.4 +/- 8.0) mg/kg, (11.31 +/- 1.30) g/kg, (68.3 +/- 14.4) micro g/L, (131 +/- 46) micro g/L in the control group; and (5.45 +/- 0.30) micro m/d, (67.81 +/- 3.56) g/kg, (106.7 +/- 8.4) mg/kg, (10.88 +/- 1.47) g/kg, (63.7 +/- 12.0) micro g/L, (120 +/- 52) micro g/L in the pair-fed group, respectively. While the time for mineralization lag and osteoid maturation obviously prolonged, (1.08 +/- 0.19) d and (7.12 +/- 2.30) d in ZD group, (0.39 +/- 0.06) d and (2.21 +/- 1.12) d in the control group, and (0.40 +/- 0.06) d and (2.12 +/- 0.58) d in the pair-fed group, respectively. In addition, bone mineral content and bone density and serum parathyroid hormone in ZD group decreased significantly and were lower than those in the control group, but not significantly different from those in the pair-fed group. There were no significant difference in femoral contents of calcium, magnesium, manganese and copper between the ZD group and the control and pair-fed groups. CONCLUSIONS: Zinc deficiency could lower the contents of parathyroid hormone and calcitonin in blood circulation affecting bone mineral deposit and causing defect in bone mineralization.

[Zinc deficiency on pathological changes of femur epiphyseal growth plate in rats].

To study zinc deficiency on pathological changes of femur epiphyseal growth plate in rats thirty Wistar rats were randomly divided into three groups: zinc-deficient group (Zd), control group (Ctr), and pair-fed group (Zp) to study the effects of zinc deficiency on femur epiphyseal growth plate of rats and the mechanism involved. After 8 weeks feeding, the histomorphology of right femur indicated that chondrocytes in the epiphyseal growth plate of Zd group were generally ill-organized and mis-shaped. The number of chondrocytes decreased. Trabecular bone in the epiphyseal of Zd group were also ill-organized, scarce and slim. The cavities of marrow in Zd animals were significantly larger than those of Ctr and Zp. The volume of trabecular bone, the mean trabecular plate density of Zd rats were significantly decreased, but their mean trabecular plate space was significantly increased. In addition, the Zd animals had significantly lower concentration of osteocalcin and growth hormone in sera. The above results suggested that zinc deficiency impaired proliferation and differentiation of chondrocytes and balance between osteoblast and osteoclast function by reduce growth hormone levels in sera. The lack of zinc in diet resulted in disorder of bone molding and ultrastructure.

[Effects of dietary calcium-deficiency on bone development in growing rats and the mechanism involved].

The effects of calcium on bone development in growing rats were studied by bone histomorphometry and the hormone changes in a model of calcium-deficient rats. Thirty growing Wistar rats were randomly allocated into three groups fed with low calcium diet, calcium-sufficient diet at libitum or pair fed with low calcium diet for 8 weeks. The calcium-deficient rats showed low bone mass, significantly decreased bone density and mineral content. The disorder of bone molding and ultrastructure at the femoral distal diaphysis of the calcium deficient rats were showed by histomorphometric parameters. The concentration of serum parathyroid hormone was significantly higher, calcitonin was significantly lower, and the content of hydroxyproline in bone was significantly lower. The results indicated that dietary calcium-deficiency might stimulate the secretion of parathyroid hormone, decrease bone mineral content and inhibit the synthesis of bone matrix, which might induce a defect on bone mineralization.

[Supplementation with micronutrients attenuating stress injuries in rats].

OBJECTIVE: To observe the protective effects of compound micronutrients (CMN) on stress-induced injury of the rats. METHODS: The experimental rats were fed with diet added micronutrients in small, medium and large dose respectively. The stress animal model was established by feet-electric shock. The behaviors in open-field test, hormons, metallothionein (MT) and the antioxidant ability of the rats were detected. RESULTS: Compared with control group, the abnormal behaviors in open-field test, increased cortisol level in serum, decreased epinephrine and norepinephrine contents in brain were observed in stress rats. Also stress induced significantly changes of MT levels in liver and brain, and declined antioxidant ability in serum and enhanced lipid peroxidation in liver of the animals. The most indicators mentioned above were obviously improved by supplementation with CMN for 6 weeks. CONCLUSION: Supplementation with CMN was beneficial to improve the stress adapting ability and to attenuate the stress-induced injuries in rats.

[The clinical studies of hyperhomocysteinemia and Alzheimer's disease].

OBJECTIVE: To observe the correlation between the decline of cognitive function and the level of plasma homocysteine in patients with Alzheimer's disease (AD). METHODS: Thirty six AD patients were selected from hospitals in Tianjin. The enrolled patients were in accord with the diagnosis criteria. Thirty two control subjects were corresponding patients without AD in the period. Blood samples were extracted from each subject to determine the levels of homocysteine (Hcy) and folate. Cognitive status was evaluated by the mini- mental state examination (MMSE) and clinical dementia rating scale (CDR). RESULTS: The mean value of serum Hcy concentration [(17.51 +/- 5.62) micromol/L] of AD group was higher than that of control group [(12.38 +/- 4.25)micromol/L]. The serum [(5.17 +/- 1.76) microg/L] and diet folate [(206.94 +/- 44.51) microg/d] concentration of AD group were lower than those of control group [(7.92 +/- 2.22) microg/L, (259.74 +/- 41.92) microg/ d]. The incidence of hyperhomocysteinemia in AD group (64%) was higher than that in control group (22%). A significant relation between Hcy concentrations and the CDR was observed. With the increase of Hcy concentrations the CDR raised, and with the increase of Hcy concentrations the MMSE decreased. CONCLUSION: Hyperhomocysteinemia is one of the risk factors inducing the onset of AD. There is a significant negative correlation between Hcy levels and cognitive levels in AD group. Folate deficiency is an important reason to cause elevated Hcy levels in AD.

Common and pathogen-specific virulence factors are different in function and structure.

In the process of host-pathogen interactions, bacterial pathogens always employ some special genes, e.g., virulence factors (VFs) to interact with host and cause damage or diseases to host. A number of VFs have been identified in bacterial pathogens that confer upon bacterial pathogens the ability to cause various types of damage or diseases. However, it has been clarified that some of the identified VFs are also encoded in the genomes of nonpathogenic bacteria, and this finding gives rise to considerable controversy about the definition of virulence factor. Here 1988 virulence factors of 51 sequenced pathogenic bacterial genomes from the virulence factor database (VFDB) were collected, and an orthologous comparison to a non-pathogenic bacteria protein database was conducted using the reciprocal-best-BLAST-hits approach. Six hundred and twenty pathogen-specific VFs and 1368 common VFs (present in both pathogens and nonpathogens) were identified, which account for 31.19% and 68.81% of the total VFs, respectively. The distribution of pathogen-specific VFs and common VFs in pathogenicity islands (PAIs) was systematically investigated, and pathogen-specific VFs were more likely to be located in PAIs than common VFs. The function of the two classes of VFs were also analyzed and compared in depth. Our results indicated that most but not all T3SS proteins are pathogen-specific. T3SS effector proteins tended to be distributed in pathogen-specific VFs, whereas T3SS translocation proteins, apparatus proteins, and chaperones were inclined to be distributed in common VFs. We also observed that exotoxins were located in both pathogen-specific and common VFs. In addition, the architecture of the two classes of VFs was compared, and the results indicated that common VFs had a higher domain number and lower domain coverage value, revealed that common VFs tend to be more complex and less compact proteins.

Comparison of metabolic profiling of cyanidin-3-O-galactoside and extracts from blueberry in aged mice.

The metabonomics changes of plasma and brain tissue after dietary supplementation with blueberry extracts (BBE) and cyanidin-3-O-galactoside from blueberry (BBM) in aged mice were investigated by (1)H NMR technique. The mice received intragastric administration of BBE (200 mg/kg/day), BBM (50 mg/kg/day), and saline water (0.9%) for 6 weeks, respectively, in the BBE, BBM, and control groups. At the end of the experiment, plasma and brain samples were collected for NMR analysis. The results demonstrated that the level of choline in plasma from BBE and BBM groups were obviously elevated relative to the control group, whereas the levels of lactate and phosphocholine in plasma were remarkably reduced. Compared with those in the control group, the levels of choline and GABA in the brain from the BBE group were obviously increased, whereas glutamate and phosphocholine in the BBE group were significantly decreased. The level of taurine in the brain from the BBM group was particularly higher than that in the control group. These results indicated supplementation with BBE or BBM might induce similar changes of endogenous plasma and brain metabolic profiles in aged mice.

Effects of epigallocatechin-3-gallate on behavioral impairments induced by psychological stress in rats.

This study was conducted to explore the effects of epigallocatechin-3-gallate (EGCG) on cognitive performances in psychological stress rats. An animal model of psychological stress was developed by restraint stress for three weeks. Male Wistar rats were randomly assigned to four groups as follows: normal control group, stress control group and two stress groups with green tea polyphenols (GTPs) and EGCG modulation, respectively. The changes of behavioral performances of rats were examined by the open-field test and step-through test. Results showed that behavioral performances of stress control group were changed abnormally, and they were improved in GTPs and EGCG modulation groups. In addition, plasma levels of cortisol, dopamine, norepinephrine, 5-hydroxytryptamine, interleukin-6 and interleukin-2 were detected. Stress control group had increased contents of cortisol, interleukin-6 and interleukin-2, and meanwhile had declined levels of 5-hydroxytryptamine and catecholamines. These changes in GTPs and EGCG modulation groups were similar to that of the normal control group. The expressions of metallothioneins in the hippocampus were detected by reverse transcription polymerase chain reaction. In contrast with the normal control group, their expressions in all the three stress groups were enhanced clearly. The results suggested that GTPs and EGCG modulation could improve the cognitive impairments induced by psychological stress. The related mechanisms may be involved with the changes of catecholamines, 5-hydroxytryptamine, cytokines and expressions of metallothioneins.