[Advances in nutritional support for children undergoing hematopoietic stem cell transplantation]. / é€ è¡€å¹²ç»†èƒžç§»æ¤å„¿ç«¥çš„è¥å »æ”¯æŒè¿›å±•.

Hematopoietic stem cell transplantation (HSCT) is a therapeutic option for various potentially life-threatening malignant and non-malignant diseases in children, such as malignancies, immunodeficiency syndromes, severe aplastic anemia, and inherited metabolic disorders. During transplantation, many factors can affect the nutritional status of the children, including radiotherapy, chemotherapy, gastrointestinal disorders, graft-versus-host disease, and medications. Malnutrition has been associated with decreased overall survival and increased complications in children undergoing HSCT, making nutritional support a crucial component of their management. However, currently, there is a lack of guidelines or consensus on nutritional support for children undergoing HSCT in China. Therefore, this review summarizes the progress in nutritional support for children undergoing HSCT, aiming to provide clinical guidance.

[Development and thoughts of digestive endoscopy in children]. / å„¿ç«¥æ¶ˆåŒ–å† é•œçš„å‘å±•ä¸Žæ€è€ƒ.

After nearly 40 years of development, digestive endoscopy in children has been widely applied, and it has helped to expand the spectrum of pediatric digestive system diseases and greatly improve the diagnosis and treatment of pediatric digestive system diseases. Pediatric digestive endoscopy has become a subject. However, there are some problems such as the unbalanced development of pediatric digestive endoscopy across China, the lack of homogeneity in diagnosis and treatment system, the tendency of adult-oriented diagnosis and treatment techniques, and the localization of training quality, which affect the standardized and healthy development of pediatric digestive endoscopy. The diagnosis and treatment with digestive endoscopy in children should adhere to both pediatric characteristics and technological innovation to propose the concept of comfort, emphasize the importance of standardization (including the space and process for endoscopic diagnosis and treatment, perioperative evaluation, training mode, and access qualification), standardize the minimally invasive techniques, and develop artificial intelligence. It is of great importance to formulate related consensus statements and guidelines on the basis of medical safety and the features of the growth and development of children, so as to achieve the high-quality development of pediatric digestive endoscopy, effectively improve the diagnosis and treatment levels of pediatric digestive endoscopy, and bring benefits to more pediatric patients.

[Role of vitamin D in pediatric irritable bowel syndrome].

Irritable bowel syndrome (IBS) is a common functional gastrointestinal disease in children and has the clinical manifestations of recurrent abdominal pain with the changes in defecation frequency or stool form. Many studies have shown that children with IBS have a significantly lower vitamin D level than the healthy population, and vitamin D supplementation can significantly improve the clinical symptoms and quality of life of the children, suggesting that vitamin D supplementation may play a role in the treatment of IBS. This article reviews the association between vitamin D and IBS in children and elaborates on the possible mechanism of action of vitamin D.

[Age distribution characteristics of intestinal segmented filamentous bacteria and their relationship with intestinal mucosal immunity in children].

OBJECTIVE: To investigate the age distribution characteristics of intestinal segmented filamentous bacteria (SFB) in children and their relationship with intestinal mucosal immunity. METHODS: The fresh feces of 177 children and the ileocecal fluid of 47 children during colonoscopy were collected. The SFB was determined by real-time PCR. The concentration of secretory immunoglobulin A (sIgA) was determined by enzyme-linked immunosorbent assay. The numbers of interleukin 17A (IL-17A) cells and intraepithelial lymphocytes in the terminal ileum mucosa and the expression of transcription factors associated with the differentiation of T helper (Th) cells, T-box transcription factor (T-bet), forkhead box P3 (FOXP3), and retinoid-related orphan receptor gamma t (ROR-γt), were determined by immunohistochemistry. RESULTS: The positive rate of intestinal SFB in these children was 19.2% (34/177). Trend analysis showed that the positive rate of SFB was correlated with age: the rates for children aged 0-, 1-, 2-, 3-, 4-, 5-, 6-, and 7-15 years were 40%, 47%, 32%, 15%, 12%, 13%, 15% and 4% respectively (P<0.001). The concentration of sIgA in intestinal fluid was significantly higher in SFB-positive children (n=24) than in SFB-negative children (n=23) (P<0.01). The number of intraepithelial lymphocytes in the terminal ileum mucosa and the expression of T-bet, FOXP3, and ROR-γt were not significantly different between the SFB-positive group (n=12) and the SFB-negative group (n=11), but the number of IL-17A cells in the terminal ileum mucosa was significantly lower in the SFB-positive group than in the SFB-negative group (P<0.05). CONCLUSIONS: Intestinal SFB colonization in children is age-related, and the colonization rate is relatively high in children under 3 years old. In SFB-positive children, the secretion of intestinal sIgA is increased, while the number of IL-17A cells in the terminal ileum is reduced.

[Research advances in the relationship between cow's milk allergy and gastroesoph-ageal reflux in infants].

Gastroesophageal reflux (GER) and cow's milk allergy (CMA) are common disorders in infants. In recent years, more and more research has investigated the relationship between these two diseases. Some studies reported that about half of the cases of GER in infants younger than 1 year may be an association with CMA. Therefore, overall understanding the role of CMA on the pathogenesis of GER has a great importance on improving clinical level of diagnosis and therapy. This review article tried to elaborate advances in research on the relationship between CMA and GER in infants, including epidemiology, pathogenesis, clinical manifestations, diagnosis and treatment.

[Research progress on biological toxicity of zinc oxide nanoparticle and its mechanism].

Zinc oxide nanoparticle (nano-ZnO) has a size between 1 and 100 nm. Nano-ZnO has some special effects, such as small size effect, surface effect, quantum size effect, which makes it different from the ordinary ZnO, and is widely used in rubber industry, food processing, cosmetics and pharmaceutical fields. It has been reported that nano-ZnO has toxic effects in vitro and in vivo, but the mechanism of toxicity is still unclear. Therefore, it is important to evaluate the safety nano-ZnO by studying its biological toxic effects and related mechanisms. In this paper, we summarize the characterization, ingestion pathway, metabolism, systematic toxicity of nano-ZnO and its mechanisms, which may provide us with new strategy for the toxic research of nano-ZnO.

[Relationship between tight junction proteins and Helicobacter pylori-associated gastric diseases].

Helicobacter pylori (Hp) infection is an important cause of chronic gastritis and peptic ulcer, but their pathogenesis is unclear. The role of gastric mucosal barrier dysfunction induced by impaired structure and function of tight junction in the pathogenesis of Hp-associated gastric diseases has received considerable attention in recent years. Tight junction is composed of a variety of proteins and molecules, including 3 integral membrane proteins (occludin, claudins, and junctional adhesion molecules) and a cytoplasmic protein (zonula occludens). This paper mainly describes the composition and function of various tight junction proteins, changes in tight junction protein function induced by Hp infection and their relationship with the incidence of gastric diseases, and the significance of enhancing the tight junction protein function in the prevention and treatment of Hp-associated gastric diseases.

[Advances in research on extra-oesophageal symptoms of pediatric gastroesophageal reflux].

The manifestations of pediatric gastroesohageal reflux (GER) are varied and complex. Extra-oesophageal symptoms, including GER-related respiratory diseases, ear, nose and throat diseases, oral diseases and neuropsychiatric symptoms, are thought to be major manifestations of pediatric GER, but the causal relationship between GER and these extra-oesophageal symptoms is still unclear. Therefore, we describe the progress of research on the relationship between GER and asthma, chronic cough, laryngitis, pharyngitis, laryngeal papilloma, sinusitis, otitis media, dental erosion, apparent life-threatening event, and the crying baby syndrome in this review. It provides new strategies for the diagnosis and treatment of GER-related diseases in children.

[Value of protein array in the diagnosis of Helicobactor pylori infection in children].

OBJECTIVE: To study the value of multiple Helicobacter pylori (H.pylori) antibody detection by protein array in the diagnosis of H.pylori infection in children. METHODS: Biopsy specimens obtained by gastroscopy from 120 children with digestive system symptoms were detected by rapid urease test (RUT) and modified Giemsa staining. Positivity in both RUT and Giemsa staining was the "gold criterion" of H.pylori infection. Serum samples of these patients were obtained and the antibodies against cytotoxin associated gene A protein (CagA), vacuolating toxin A (VacA), urease, heat shock protein 60 (Hsp60) and RdxA (nitroreductase) were detected by protein array technique. RESULTS: H.pylori infection was identified according to the "gold criterion" in 60 children. Compared with the "gold criterion", the goodness of fit and the coefficient of contingency in the diagnosis of H.pylori infection of the following four groups antibody detection were all statistically significant (P<0.001): anti-Ure antibody alone, anti-Ure antibody combined with anti-CagA antibody, anti-Ure antibody combined with anti-VacA antibody and anti-Ure antibody combined with anti-CagA and anti-VacA antibody. The sensitivity, specificity and accuracy of the detection of anti-Ure antibody combined with anti-CagA antibody for the diagnosis of H.pylori infection were 81.7%, 91.7% and 86.7%, respectively. The antibody detection showed a high positive predictive value (90.7%) and a high negative predictive value (83.3%). CONCLUSIONS: The antibody detection by protein array, especially the detection of anti-Ure antibody combined with anti-CagA antibody, is valuable in the diagnosis of H.pylori infection.

[Role of oxidative stress in the pathogenesis of esophageal mucosal injury in children with reflux esophagitis].

OBJECTIVE: To investigate the role of oxidative stress in the pathogenesis of esophageal mucosa injury in children with reflux esophagitis (RE). METHODS: Esophageal mucosal samples from 36 children with RE (7 months to 16 years of age) were obtained by gastroscopy. The parameters of oxidative stress, including the contents of malondialdehyde (MDA), glutathione (GSH) and nitric oxide (NO) and total superoxide dismutase (T-SOD) activity in the esophageal mucosa as well as the protein content of the esophageal mucosa, were measured. Twenty children (3 to 16 years of age) without esophageal mucosal injury by gastroscopy served as controls. RESULTS: There was no significant difference in the protein content of the esophageal mucosa between the RE and the control groups. The content of MDA in the RE group (15.36+/- 16.67 nmol/mg) was significantly higher than that in the control group (7.51+/- 6.17 nmol/mg) (P<0.01). The activity of T-SOD in the RE group (30.43+/- 35.09 U/mg) was statistically lower than that in the control group (56.34+/- 51.73 U/mg) (P<0.05). No significant differences were observed in GSH and NO contents between the two groups. CONCLUSIONS: The MDA content increases and the SOD content decreases in the esophageal mucosa in children with RE. This suggests that oxidative stress seems to be an important mediator in generation of esophageal mucosal injury.

[Roles of enteric nervous system neurotransmitters and interstitial cells of Cajal in the colon in slow transit constipation in rats].

OBJECTIVE: To evaluate the roles of enteric nervous system neurotransmitters, nitric oxide (NO), substance P (SP) and vasoactive intestinal polypeptide (VIP), and interstitial cells of Cajal (ICC) in the colon in slow transit constipation in rats. METHODS: Thirty-two healthy Wistar rats were randomly assigned to control and constipated groups. In the constipated group, the rats were daily administered with diphenoxylate (8 mg/kg) to develop slow transit constipation, while the control rats were fed with water. The number and the weight of fecal granule and the body weight of rats were recorded every 5 days for 90 days. Transit functions of intestinal movement were examined by an activated charcoal suspension pushing test one week after stopping the administration of diphenoxylate. The levels of NO and SP in the colonic mucosa were measured by nitrate reductase methods and ELISA respectively. The distribution of VIP and ICC positive cells confirmed with symbolic c-kit+ cells in the colonic wall were observed by immunohistochemical methods. RESULTS: The daily number of fecal granule in the constipated group was significantly less than that in the control group (P<0.01). The mean weight of each fecal granule in the constipated group was significantly higher than that in the control group (P<0.01). The discharge time of the first granule of black faeces in the constipated group (430.2+/- 132.1 min) was significantly longer than that in the control group (337.2+/- 74.7 min; P<0.05). There were no significant differences in NO and SP levels and the density of VIP positive cells in the distal colonic segment between the two groups. The number of c-kit+ cells in the distal colonic wall in the constipated group was significantly reduced compared with that in the control group (P<0.05). CONCLUSIONS: The reduction of ICC number in the distal colon may be contributed to the pathogenesis of slow transit constipation in rats.

[Forlax in the treatment of childhood constipation: a randomized, controlled, multicenter clinical study].

OBJECTIVE: To determine the therapeutic effectiveness and safety of polyethylene glycol 4000 (forlax) in the treatment of constipation in children over 8 years old. METHODS: This study was designed as a randomized, positive medicine (lactulose) controlled multicenter trial. A total of 216 children with constipation from 8-18 years old from 7 hospitals across China who were matched with a uniform entry criteria were enrolled in this study. The 216 patients were randomized to receive either oral forlax (20 g/d, n=105) or lactulose (15 mL/d, n=111) for 2 weeks. The therapeutic effects, including bowel movement frequency, stool consistency, clinical complete remission rate of constipation and abdominal symptoms, and the safety of forlax and lactulose were evaluated at 1 and 2 weeks of treatment. RESULTS: The median weekly frequency of bowel movement in the forlax group increased by 4 and 5 times respectively after 1 and 2 weeks of treatment, and increased by 3 and 4 times in the lactulose group (P < 0.05). The stool consistency of the two groups was both improved significantly after treatment. The Bristol score of stool consistency of the forlax and lactulose groups were 3.41+/-1.11 and 3.64+/-1.33 respectively (P < 0.05) after 1 week of treatment, and were 4.26+/-0.89 and 3.63+/-1.33 respectively (P < 0.05) after 2 weeks of treatment. The clinical complete remission rate of constipation in the forlax and lactulose groups was 70% and 40% respectively (P < 0.05) by week 1 of treatment, and that was 72% and 41% respectively (P < 0.05) by week 2 of treatment. Abdominal pain disappeared in 75% of patients in the forlax group but in only 57% in the lactulose group by week 2 of treatment (P < 0.05). No serious adverse events happened and no abnormalities were found in laboratory tests and physical examinations in the two groups after medication. CONCLUSIONS: Forlax is safe and effective in the treatment of constipation in children over 8 years old.

[Noncardiac chest pain and gastroesophageal reflux in children].

OBJECTIVE: To investigate the relationship between noncardiac chest pain (NCCP) and gastroesophageal reflux (GER) in children and to assess the diagnostic value of esophageal pH monitoring in patients with NCCP. METHODS: Ambulatory 24 h esophageal pH monitoring was performed in 36 NCCP cases (patient group) with recurrent chest pain and without respiratory diseases and musculoskeletal abnormalities in chest, and 20 of them underwent gastric endoscopy. Eleven of the 20 cases were found to have esophagitis (esophagitis group), while the other 9 cases showed no signs of esophagitis (non-esophagitis group) according to the diagnostic criteria of esophagitis. RESULTS: The episode of esophageal pH < 4, the number of reflux longer than 5 min, the longest reflux time, the percent time of pH < 4 and Boix-Ochoa score in the patient group were 60 +/- 7, 2.44 +/- 0.74, (12.4 +/- 2.8) min, 6.72 +/- 1.39, 24.6 +/- 3.9, respectively, as compared to 33 +/- 4, 0.35 +/- 0.11, (4.3 +/- 0.9) min, 1.25 +/- 0.19, 7.7 +/- 0.9 in the control group. The difference between the two groups had reached significance (t = 3.44, 2.79, 2.73, 3.89, 4.24, respectively, all P < 0.01). The positive rate of acid reflux in the patient group was 58.3% (21/36) whose Boix-Ochoa score higher than 11.99. Eleven of the 20 cases (55.0%) receiving endoscopy were found to have esophagitis, among them the positive rate of GER occurred 81.8% (9/11). Whereas, the other 9 cases (45.0%, 9/20) showed non-esophagitis and the positive rate of GER showed 33.3% (3/9). The number of reflux longer than 5 min and the percent time of pH < 4 in the esophagitis group were 5.8 +/- 2.0, 12.5 +/- 3.5, respectively, as compared to 0.9 +/- 0.5, 3.4 +/- 1.4 in the non-esophagitis group. Significant difference were observed between the two groups (Z = -2.400, -2.545, respectively, all P < 0.05). The episode of esophageal pH < 4, the longest reflux time, and Boix-Ochoa score in the esophagitis group were 73 +/- 11, (26.4 +/- 7.3) min, 41 +/- 10, respectively, as compared to 34 +/- 11, (4 +/- 3) min, 14 +/- 5 in the non-esophagitis group. The difference between the two groups showed significance (Z = -2.926, -2.675, -2.584, respectively, all P < 0.01). CONCLUSIONS: GER is very common in children with NCCP. Esophageal pH monitoring has a therapeutic predictive value in addition to its diagnostic merit for NCCP in children.

Effects of antioxidants and NO on TNF-alpha-induced adhesion molecule expression in human pulmonary microvascular endothelial cells.

Pro-inflammatory cytokines initiate the vascular inflammatory response via upregulation of adhesion molecules on the endothelium. Recent observations suggest that reactive oxygen intermediates may play a pivotal role in TNF-alpha signaling and upregulate gene expression. We therefore evaluated the effects of pyrrolidine dithiocarbamate (PDTC; 0.1 mM) and spermine NONOate (Sper-NO; 1 mM) on adhesion molecule expression and nuclear factor kappa B (NF-kappaB) activation induced by TNF-alpha (10 ng/ml) in cultured human pulmonary microvascular endothelial cells (PMVEC). Treatment of cells with TNF-alpha for 4 h significantly induced the surface expression of E-selectin and ICAM-1. Treatment with TNF-alpha for 8 h significantly induced the surface expression of E-selectin, ICAM-1 and VCAM-1. The upregulation of these adhesion molecules was suppressed significantly by pretreatment with PDTC or Sper-NO for 1 h. 8-Bromo-cyclic GMP (1 mM) had no such effect, suggesting that the NO donor's effect was non-cGMP-dependent. The mRNA expression of E-selectin, ICAM-1 and VCAM-1, and activation of NF-kappaB induced by TNF-alpha for 2 h were decreased significantly by the above two pretreatments. N-acetylcysteine (10 mM) and S-nitroso-N-acetylpenicillamine (1 mM) had little inhibitory effects on the cell surface and mRNA expression of these adhesion molecules stimulated by TNF-alpha. Treatment with TNF-alpha for 4 h enhanced HL-60 leukocyte adhesion to human PMVEC, the effect of which was inhibited significantly by pretreatment with PDTC or Sper-NO. These findings indicate that both cell surface and mRNA expression of adhesion molecules in human PMVEC induced by TNF-alpha are inhibited significantly by pretreatment with PDTC or Sper-NO, possibly in part through blocking the activation of NF-kappaB. Although our in vitro results cannot be directly extrapolated to the in vivo situation, they suggest a potential therapeutic approach for intervention in cytokine-mediated inflammatory processes in the human lung.

Centralized isolation of Helicobacter pylori from multiple centers and transport condition influences.

AIM: To evaluate the efficacy of centralized culture and possible influencing factors. METHODS: From January 2010 to July 2012, 66452 patients with suspected Helicobacter pylori (H. pylori) infection from 26 hospitals in Zhejiang and Jiangsu Provinces in China underwent gastrointestinal endoscopy. Gastric mucosal biopsies were taken from the antrum for culture. These biopsies were transported under natural environmental temperature to the central laboratory in Hangzhou city and divided into three groups based on their transport time: 5, 24 and 48 h. The culture results were reported after 72 h and the positive culture rates were analyzed by a χ (2) test. An additional 5736 biopsies from H. pylori-positive patients (5646 rapid urease test-positive and 90 (14)C-urease breath test-positive) were also cultured for quality control in the central laboratory setting. RESULTS: The positive culture rate was 31.66% (21036/66452) for the patient samples and 71.72% (4114/5736) for the H. pylori-positive quality control specimens. In the 5 h transport group, the positive culture rate was 30.99% (3865/12471), and 32.84% (14960/45553) in the 24 h transport group. In contrast, the positive culture rate declined significantly in the 48 h transport group (26.25%; P < 0.001). During transportation, the average natural temperature increased from 4.67 to 29.14 °C, while the positive culture rate declined from 36.67% (1462/3987) to 24.12% (1799/7459). When the temperature exceeded 24 °C, the positive culture rate decreased significantly, especially in the 48 h transport group (23.17%). CONCLUSION: Transportation of specimens within 24 h and below 24 °C is reasonable and acceptable for centralized culture of multicenter H. pylori samples.

Effects of antioxidant and nitric oxide on chemokine production in TNF-alpha-stimulated human dermal microvascular endothelial cells.

Chemokines have been implicated convincingly in the driving of leukocyte emigration in different inflammatory reactions. Multiple signaling mechanisms are reported to be involved in intracellular activation of chemokine expression in vascular endothelial cells by various stimuli. Nevertheless, redox-regulated mechanisms of chemokine expression in human dermal microvascular endothelial cells (HDMEC) remain unclear. This study examined the effects of pyrrolidine dithiocarbamate (PDTC, 0.1 mM) and spermine NONOate (Sper-NO, 1 mM) on the secretion and gene expression of chemokines, interleukin (IL)-8, monocyte chemotactic protein (MCP)-1, regulated upon activation normal T cell expressed and secreted (RANTES), and eotaxin. This study also addresses PDTC and Sper-NO effects on activation of nuclear factor kappa B (NF-kappaB) induced by TNF-alpha (10 ng/ml). Treatment with TNF-alpha for 8 h significantly increased secretion of IL-8, MCP-1, and RANTES, but not of eotaxin, in cultured HDMEC. Up-regulation of these chemokines was suppressed significantly by pretreatment with PDTC or Sper-NO for 1 h, but not by 1 mM 8-bromo-cyclic GMP. The mRNA accumulation of IL-8, MCP-1, RANTES, and eotaxin, and activation of NF-kappaB were induced by TNF-alpha for 2 h; all were suppressed significantly by the above two pretreatments. These findings indicate that both secretion and mRNA accumulation of IL-8, MCP-1, and RANTES in HDMEC induced by TNF-alpha are inhibited significantly by pretreatment with PDTC or Sper-NO, possibly via blocking redox-regulated NF-kappaB activation. These results suggest that restoration of the redox balance using antioxidant agents or nitric oxide pathway modulators may offer new opportunities for therapeutic interventions in inflammatory skin diseases.

Effects of antioxidants and nitric oxide on TNF-alpha-induced adhesion molecule expression and NF-kappaB activation in human dermal microvascular endothelial cells.

Cell adhesion molecules expressed on endothelial cells in inflamed skin appear to be controlled by the actions of cytokines and reactive oxygen species. However, molecular mechanisms of the expression of adhesion molecules during skin inflammation are currently not well understood. To evaluate the role of antioxidants and nitric oxide in modulating inflammatory processes in the skin, we examined the effects of pyrrolidine dithiocarbamate (PDTC, 0.1 mM) and spermine NONOate (Sper-NO, 1 mM) on adhesion molecule expression and nuclear factor kappa B (NF-kappaB) activation induced by TNF-alpha (10 ng/ml) in cultured human dermal microvascular endothelial cells (HDMEC). Treatment of cells with TNF-alpha for 4 h significantly induced the surface expression of E-selectin and intercellular adhesion molecule-1 (ICAM-1). Treatment with TNF-alpha for 8 h significantly induced the surface expression of E-selectin, ICAM-1 and vascular cell adhesion molecule-1 (VCAM-1). The up-regulation of these adhesion molecules was suppressed significantly by pretreatment with PDTC or Sper-NO for 1 h. The mRNA expression of E-selectin, ICAM-1 and VCAM-1, and activation of NF-kappaB induced by TNF-alpha for 2 h were significantly decreased by the above two pretreatments. N-acetylcysteine (10 mM) and S-nitroso-N-acetylpenicillamine (1 mM) had no significant inhibitory effects on the cell surface and mRNA expression of these adhesion molecules stimulated by TNF-alpha. These findings indicate that both cell surface and mRNA expression of adhesion molecules in HDMEC induced by TNF-alpha are inhibited significantly by pretreatment with PDTC or Sper-NO, possibly in part through blocking the activation of NF-kappaB. These results suggest a potential therapeutic approach using antioxidant agents or nitric oxide pathway modulators in the treatment of inflammatory skin diseases.

Oxidative stress in neonates: evaluation using specific biomarkers.

Increased oxidative stress has been implicated in pathogenesis of serious diseases in neonates. We measured urinary levels of 8-hydroxy-2'-deoxyguanosine (a marker of oxidative DNA damage), acrolein-lysine adduct (a marker of lipid peroxidation and oxidative protein damage), and nitrite/nitrate (a marker of endogenous nitric oxide formation) in one-month-old neonates to examine the status of oxidative stress and its relationship to the degree of prematurity and clinical condition in neonates. Study subjects comprised three groups: healthy term neonates, clinically stable preterm neonates requiring no supplemental oxygen, and clinically sick preterm neonates requiring supplemental oxygen and ventilator support. Urinary levels of 8-hydroxy-2'-deoxyguanosine and acrolein-lysine adduct were significantly higher in sick preterm neonates than those of stable preterm and healthy term neonates. In the sick preterm group, neonates developing active retinopathy showed significantly higher levels of acrolein-lysine adduct than the other neonates without retinopathy. There were no significant differences in both urinary markers of oxidative stress between stable preterm and healthy term neonates. The urinary nitrite/nitrate levels were not significantly different among the three groups, suggesting no difference in endogenous nitric oxide formation. Collectively, these results provide evidence of augmentation of oxidative damage to DNA, lipids and proteins, especially in clinically sick preterm neonates.

[Methylenetetrahydrofolate reductase [correction of reducatase] polymorphism and asthma].

OBJECTIVE: To evaluate the association between the methylenetetrahydrofolate reductase C/T polymorphism and the prevalence and course of asthma. METHOD: Genotypes were determined in 433 asthmatic patients and 1 249 healthy subjects by the polymerase chain reaction and restriction fragment length polymorphism method. RESULTS: The frequencies of the three genotypes were 40.27% for CC, 48.44% for CT, 11.29% for TT and the frequency of allelic T was 35.51% in controls. The frequency of TT genotype in atopic asthmatic patients was significantly higher than that in controls (P = 0.026). The OR for the TT genotype compared with all CC and CT genotypes was 1.61 (95% CI 1.06 approximately 2.47). CONCLUSION: These results imply that homozygosity for this common mutation significantly increases the risk of atopic asthma.

[Effect of zinc deficiency on intestinal mucosal morphology and digestive enzyme activity in growing rat].

OBJECTIVE: In this study, a growing rat model of zinc deficiency was established to investigate the effect of zinc deficiency on intestinal mucosal morphology and digestive enzyme activity as well as to provide a scientific basis for zinc supplementation therapy in patients with diarrhea. METHOD: Three-week-old weaned Sprague-Dawley male rats (n = 30) were randomly divided into 3 groups with 10 in each: rats in the control group (ZA) were fed with a normal diet containing 30 µg/g zinc; rats in the zinc deficient group (ZD) were fed with a zinc-deficient diet containing 0.4 µg/g zinc (refer to AIN-76 formula); and rats in the paired fed group (PF) were fed with a normal diet, but the food intake was limited to intake of rats in ZD group in the previous day. All rats were provided with deionized water for drinking. Their body weight was measured and the food intake during the previous day was recorded early in the morning of the following day. Symptoms of zinc deficiency, such as anorexia, diarrhea, dermatitis, and growth retardation, were observed. Two weeks later, the rats were sacrificed and serum zinc concentration was measured. Jejunal mucosa was taken for biopsy and was stained with hematoxylin and eosin (HE). The height ratio of the jejunal mucosal villi and crypts was measured. In addition, the activity of lactase in the jejunal mucosal brush border, γ-glutamyl peptidase (GGT), and aminopeptidase N (APN) were measured. RESULT: The average weight of the rats in the ZA, ZD, and PF groups at the beginning of the experiment was (67.4 ± 5.3) g, (64.7 ± 4.8) g, and (66.5 ± 4.1) g, respectively, and the average daily food intake was (11.2 ± 1.0) g, (11.6 ± 1.6) g, and (11.2 ± 1.4) g, respectively. The intergroup differences were not significant. On the 7(th) day of experiment, no significant differences in average food intake were observed between the ZD group and the ZA and PF groups, but the average body weight in the ZD group was significantly lower than that in the ZA and PF groups (P < 0.01). At the end of the experiment (2 weeks), the average weight in the ZD group (112.0 ± 11.5) g was significantly lower than that in the ZA (164.0 ± 15.9) g and PF groups (137.5 ± 16.2) g. The average food intake in the ZD group (13.4 ± 5.1) g was significantly lower than that in the ZA group (18.2 ± 2.4) g (P < 0.01). Serum zinc level in the ZD group (733 ± 231) µg/L was significantly lower than that in the ZA (1553 ± 159) µg/L and PF groups (1457 ± 216) µg/L (P < 0.01). The height ratio of jejunal mucosa villus and crypt in the ZA, ZD, and PF groups was 2.98 ± 0.5, 2.77 ± 0.5, and 2.81 ± 0.7, respectively, and lactase activity was (26.1 ± 15.0) U/mg, (27.4 ± 12.8) U/mg, and (40.8 ± 18.5) U/mg, respectively, without significant intergroup differences. The GGT activity in the jejunal mucosa in the ZD group (12.7 ± 6.5) U/g was significantly lower than that in the ZA (19.1 ± 10.4) U/g and PF groups (18.5 ± 7.7) U/g, but the difference was not significant. The activity of APN in the jejunal mucosa in the ZD group (25.5 ± 7.5) U/g was significantly lower than that in the ZA (48.7 ± 16.8) U/g and PF groups (43.9 ± 14.5) U/g (P < 0.01). CONCLUSION: Zinc deficiency can cause loss of appetite, weight loss, and decreased activity of peptidase in the jejunal mucosal brush border. Zinc deficiency has little effect on the height ratio of the villus and crypt and lactase activity, thereby indicating that zinc deficiency may first affect protein digestion and absorption.