[A nested case-control study on the association of neonatal cord blood selenium, iron and copper with congenital heart disease].

Objective: To investigate the relationship between the levels of selenium, iron and copper in cord blood of neonates and the risk of congenital heart disease (CHD), and analyze their interaction effects. Methods: The subjects were obtained from the birth cohort in Lanzhou area established from 2010 to 2012. A baseline survey was conducted in the first trimester, and the follow-up was conducted in the second trimester, third trimester and 42 days after delivery. The umbilical vein blood was collected from newborns at delivery, and information on their birth outcomes was extracted from medical records. A nested case-control study was used to select 97 neonates with CHD newly diagnosed by echocardiography as the case group, and 194 neonates were selected as the control group by 1∶2 matching according to their mother's age, block and CHD onset time. Inductively coupled ion mass spectrometry was used to detect the concentrations of selenium, iron and copper in neonatal cord blood. The element exposure was categorized into three groups, the low, medium and high concentrations, according to the quartiles Q1 and Q3 of selenium, iron and copper concentrations in the control group. The association between cord blood selenium, iron and copper concentrations and CHD was analyzed by conditional logistic regression model using medium concentration as the reference standard. The association of their interactions with CHD was analyzed by a phase multiplication model. Results: The M (Q1, Q3) concentration of neonatal cord blood copper was 746.12 (467.48, 759.74) µg/L in the case group and 535.69 (425.21, 587.79) µg/L in the control group, with a statistically significant difference between the two groups (P<0.05). After adjustment for confounders, logistic regression models showed that the risk of CHD development was increased in neonates with either high copper in cord blood (OR=4.062, 95%CI: 2.013-8.199) or high copper combined with high iron (OR=3.226, 95%CI: 1.343-7.750). No correlation was observed between selenium and iron concentrations and the development of CHD in neonates. There was a multiplicative interaction between copper and iron in cord blood on the risk of developing CHD (OR=1.303, 95%CI: 1.056-1.608). Conclusion: There is a multiplicative interaction between iron and copper elements. The high copper and the high copper combined with high iron in umbilical cord blood are risk factors for neonatal CHD.

[Correlation analysis between lactic, procalcitonin and disease severity in patients with imported malaria from Africa].

Objective: To explore the clinical characteristics, the correlation between lactate, procalcitonin and disease severity of imported malaria from Africa. Methods: The clinical data of 186 patients with imported malaria were collected from January 1, 2018 to April 30, 2021 in the Guangzhou Eighth People's Hospital, Guangzhou Medical University. The general conditions, clinical symptoms, laboratory tests, treatment, and prognosis of the patients were analyzed retrospectively. Receiver operating characteristic (ROC) curves were drawn to evaluate the value of relevant indicators in predicting severe malaria. Results: A total of 186 patients were divided into severe cases (n=48) and non-severe cases (n=138) in this study, of which the mean age was (38.3±10.3) years, 169(90.9%) cases were male, 17(9.1%) cases were female. The main infection species was Plasmodium falciparum, in a total of 166 cases (89.2%). The severe cases were all falciparum malarias. Compared with the non-severe group, the lactic, procalcitonin, white blood cell count and neutrophil count of the severe group were all increased, the differences were all statistically significant (all P<0.01); the percentage of monocytes, red blood cell count, hemoglobin, hematocrit and platelet count were all decreased, the difference were all statistically significant (all P<0.01). The areas under the ROC curves (AUC)(95%CI) of lactate, procalcitonin, red blood cell count, hemoglobin, hematocrit and platelet count for predicting severe malaria was 0.753(0.663-0.844), 0.755(0.670-0.841), 0.782(0.700-0.864), 0.738(0.652-0.823), 0.760(0.676-0.844), 0.778(0.699-0.857), respectively (all P<0.01). When the Youden indexes were at their maximum, the best cut-off value of lactic was 2.29 mmol/L, with sensitivity in predicting of severe malaria was 56.3%, and the specificity was 93.5%; the best cut-off value of procalcitonin was 2.12 µg/L, with sensitivity in predicting of severe malaria was 77.1%, and the specificity was 68.1%. The fatality rate of severe malaria was 4.2% (2/48). Conclusions: Anemia and thrombocytopenia are common indicators for predicting the severity of malaria. Lactic and procalcitonin also have higher predictive value for severe malaria, which could help to identify severe malaria as early as possible, improve the cure rate and reduce the risk of death.

[Analysis of bronchoscope-guided tracheal intubation in 12 cases with coronavirus disease 2019 under the personal protective equipment with positive pressure protective hood].

Endotracheal intubation is an independent risk factor for respiratory infectious diseases. We conducted a retrospective study in 12 cases with COVID-19 who underwent endotracheal intubation at ICU of the Guangzhou eighth hospital from January 20 to February 10, 2020. The intubation procedure, anesthetic regimen, and complication were collected and analyzed. The 9 healthcare workers who involved in intubation received virus nucleic acid test and 14 days temperature monitoring. All 12 patients were successfully intubated under the guidance of bronchoscope, without any complications. Midazolam, Propofol and Morphine or fentanyl were used for sedation and analgesia, avoiding patients cough and agitated during the procedure. The 9 healthcare workers were protected under the Personal Protective Equipment(PPE) with positive pressure protective hood. The detection of oropharyngeal swab virus nucleic acid were negative in all 9 healthcare workers, none of them had fever or any respiratory symptoms. The PPE with positive pressure protective hood should be needed to perform bronchoscope-guided endotracheal intubation in patients with COVID-19, it could strengthen to protect healthcare workers from virus exposure.

Review and Prospect of Pathological Features of Corona Virus Disease.

ABSTRACT: Since 2003, coronavirus has caused multiple major public health events that resulted in global epidemics, such as severe acute respiratory syndrome （SARS）, Middle East respiratory syndrome （MERS） and corona virus disease 2019 （COVID-19）. Especially since COVID-19 outbroke in Wuhan, Hubei, in December 2019, coronavirus has had a significant impact on people's health and lives. But so far, the pathological diagnosis of COVID-19 has been relatively deficient： it is still confined to the pathological findings of punctured organs, and the majority of medical workers have poor awareness of its pathological characteristics. The COVID-19, as same as SARS and MERS, is caused by coronaviruses and can cause viral pneumonia. They have certain similarities. This article comprehensively reviews the pathological features observed in the autopsies of the aforementioned three diseases, in order to provide reference to the analysis of pathological changes of COVID-19.

Retrospective Analysis of 61 Cases of Children Died of Viral Pneumonia.

ABSTRACT: Objective To retrospectively analyze the forensic pathological postmortem examination and clinical data of children who died of viral pneumonia in identification of cause of death cases and to discuss the clinical characteristics and pathological features of viral pneumonia in children, in order to provide reference to pathological diagnosis of viral pneumonia in children caused by 2019 novel coronavirus （2019-nCoV） infection. Methods Postmortem examination data from 61 cases of children whose causes of death were identified as viral pneumonia in recent years were collected from the Center of Forensic Identification, Southern Medical University. The gender, age, clinical symptoms and pathological features were comparatively analyzed. Results Among the 61 cases of children who died of viral pneumonia, most were within 2 years old （83.61%）, and a large proportion died within 2 weeks after the onset of the disease （91.80%）. Gross changes in postmortem examination included respiratory mucosal hyperemia, pleural effusion, pulmonary swelling, variegated pulmonary pleura and serosa, as well as focal pulmonary hemorrhage and pulmonary edema. A large proportion of sick children had enlarged mesenteric lymph nodes （83.61%） and thymic dysplasia （21.31%）. Histopathological changes included edema of alveoli and interstitial substance, pneumorrhagia，shedding of alveolar epithelial cells, serous and （or） fibrous exudation in the alveoli, formation of viral inclusions, formation of transparent membranes, infiltration of inflammatory cells that mainly consisted of macrophages and lymphocytes in interstitial substance and alveoli. Viral infections often affected the heart and gastrointestinal tract. Conclusion The clinical symptoms of children with viral pneumonia are difficult to notice, and because the immune systems of children are not fully developed and they have poor immunity, they can easily become severely ill and even die. Analyzing the forensic autopsies and the histopathological characteristics could provide reference for pathological diagnosis of viral pneumonia.

[Application of RT-qPCR in the Study of Forensic Pathology].

Reverse transcription quantitative real-time polymerase chain reaction （RT-qPCR） is a convenient and highly efficient method for the detection of mRNA in tissues or body fluid samples. It has the characteristics of easy operation, high sensitivity and specificity, etc. With a wide application in medicine, biology and other fields, RT-qPCR technique has made some progresses in the research field of forensic pathology. This paper reviews the application value of RT-qPCR in the study of forensic pathology and current situation, as well as the research progress at home and abroad reviews. It also summarizes the notes of samples extraction, RT-qPCR experiments and data processing, which aims to provide reference for the forensic research and its application.

Leptin promotes apoptosis and inhibits autophagy of chondrocytes through upregulating lysyl oxidase-like 3 during osteoarthritis pathogenesis.

OBJECTIVE: Leptin has been found highly expressed in human osteoarthritis. We aimed to explore the possible effects and mechanisms of leptin on the apoptosis and autophagy of chondrocytes during osteoarthritis pathogenesis. METHODS: Gene expression profile from osteoarthritis affected and preserved cartilage were downloaded from NCBI's Gene Expression Omnibus database (GSE57218). Lysyl oxidase-like 3 (LOXL3) mRNA expression in cartilage tissues and leptin concentration in joint synovial fluid (SF) was measured in samples from 45 osteoarthritis patients and 25 healthy donors by real-time PCR and radioimmunoassay, respectively. Rat osteoarthritis model was induced by anterior cruciate ligament transection (ACLT). The expression of apoptosis regulators and autophagy markers were detected by Western blot. Cell survival and cell apoptosis were identified by CCK-8 and flow cytometry, respectively. RESULTS: Re-analysis on GSE57218 indicated that LOXL3 mRNA was upregulated in osteoarthritis affected cartilage. LOXL3 mRNA was upregulated in osteoarthritis patients, which was positively correlated with SF leptin concentration. Similar results were obtained in rat osteoarthritis model. Moreover, ACLT surgery led to a significant increase in the protein levels of cleaved caspase 3, and a notable decrease in the protein levels of Bcl-2, LC3 II/LC3 I and Beclin1. Silencing of LOXL3 in ACLT and leptin treated primary chondrocytes significantly inhibited cell apoptosis, and promoted cell proliferation and autophagy. Moreover, overexpression of LOXL3 remarkably inhibited autophagy of chondrocytes via activating mTORC1. CONCLUSIONS: LOXL3, a downstream of leptin, stimulated the apoptosis, but inhibited the autophagy of chondrocytes. LOXL3 is a potential therapy target for osteoarthritis.

Consistency between molecular phylogeny and morphological classification of the Salix matsudana Koidz. complex (Salicaceae).

The morphological species concept is based on morpho-logical traits, which are often subject to subjectivity or artifact. Molecular evidence is needed to test the reliability of morphological classification of taxa that are controversial and to provide appropriate taxonomic de-limitation. In this study, we used 15 single-copy nuclear loci and 2 chloroplast fragments to verify the morphological classification of the Salix matsudana Koidz. complex using phylogenetic approaches. Complete sequence alignment showed slight diversification in nuclear sequences and no variety in chloroplast DNA fragments. Phylogenetic trees revealed a monophyletic group consisting of all individuals of S. matsudana and 2 clades within this group, with a 100% bootstrap support value and 1.00 posterior probability. The topology of the phylogenetic trees was highly consistent with the morphological classification of the S. matsudana complex. Verifying the genetic background of these classification units based on remarkable morphological differences will provide a foundation for future studies of Salix and the breeding of new horticultural varieties.

A novel set of single-copy nuclear DNA markers for the genetic study of Salicaceae.

Species of Populus are widely distributed worldwide, playing a significant role in both ecology and economy. However, the lack of single-copy nuclear markers limits knowledge about the phylogeny and population genetics of this genus. In the present study, primer pairs of 15 single-copy nuclear markers were developed through bioinformatic methods based on complete genomic sequences of Populus trichocarpa and Salix arbutifolia. Twenty individuals of Populus davidiana Dode and Salix matsudana Koidz were used to evaluate the basic application of these markers with respect to marker length and diversity indices, respectively. The utility of single-copy nuclear markers is anticipated to facilitate further studies about the phylogeny, population genetics, and phylogeography of this genus, in addition to providing information about the evolutionary dynamics of Salicaceae.

Effects of RXRα on proliferation and apoptosis of pancreatic cancer cells through TGF-ß/Smad signaling pathway.

OBJECTIVE: The aim of this study was to investigate the effects of retinoid X receptor α (RXRα) on the proliferation and apoptosis of pancreatic cancer cells through the transforming growth factor-ß (TGF-ß)/Smad signaling pathway. PATIENTS AND METHODS: The expression of RXRα in pancreatic cancer tissues and para-carcinoma tissues was detected via immunohistochemistry. Human pancreatic cancer PANC-1 cells were cultured and treated with RXRα in vitro. The apoptosis rate of cells was detected via flow cytometry. Furthermore, changes in the protein expression level of TGF-ß/Smad signaling pathway were detected via Western blotting. RESULTS: The protein expression level of RXRα in pancreatic cancer tissues was significantly higher than that of para-carcinoma tissues. RXRα significantly promoted the proliferation and inhibited the apoptosis of pancreatic cancer cells. Moreover, RXRα could also activate the TGF-ß/Smad signaling pathway. CONCLUSIONS: RXRα promotes the proliferation and inhibits the apoptosis of pancreatic cancer cells through the TGF-ß/Smad signaling pathway.

[Analysis of correlation between plasma trough level and response of generic imatinib in the treatment of Chinese patients with chronic myeloid leukemia].

Objective: To analyze the correlation between plasma trough level of generic imatinib and its metabolism and clinical outcomes in Chinese patients with chronic myeloid leukemia in chronic phase (CML-CP) . Methods: The 21 patients with CML-CP who enrolled in a clinical trial YMTN 1.0 from Oct 11(th), 2012 to May 8(th), 2013 and received generic imatinib were as study subjects. The correlation between steady plasma trough levels of imatinib and its metabolism with clinical response, age, weight and body surface area (BSA) were evaluated. Results: ①The mean steady plasma trough level of generic imatinib and its metabolism was (1 185.07±417.91) µg/L and (251.53±76.50) µg/L, respectively. ②Age, weight and BSA has no significant effects on plasma trough level of generic imatinib and its metabolism (P>0.05) . ③Patients with steady plasma trough level of generic imatinib more than 1 000 µg/L are possible to have higher major molecular response (MMR) /complete molecular response (CMR) rate than those below 1 000 µg/L (42% vs 0, P<0.05) . Conclusion: Plasma trough levels of generic imatinib varied in CML patients. The steady plasma trough levels of generic imatinib is maybe related to molecular response in CML patients.

Extracts from Plastrum testudinis promote proliferation of rat bone-marrow-derived mesenchymal stem cells.

OBJECTIVES: The purpose of this study is to identify active components of PT involved in promoting proliferation of MSCs and to investigate its mechanism. PT was extracted with petroleum ether, ethyl acetate, ethanol and water respectively. MATERIALS AND METHODS: Evidence provided by MTT, HE stain, BrdUrd, PCNA immunoreactivity and cell cycle indicated that Plastrum Testudinis Extracted with ethyl acetate (PTE) is the only active components responsible for increasing MSCs proliferation. RESULTS: This finding leads us to identify the chemical component of PTE. Steroid, fatty acids and their esters components in PTE were determined by GC-MS and HPLC. The mechanism of PTE action may be associated with the up-regulation of BMP4. CONCLUSIONS: Our findings give novel insights into the promoting effects of Plastrum Testudinis on proliferation of MSCs and help to identify the chemical component and to clarify the mechanism of its pharmacological activities.

L6H21 prolonged rats survival after limb allotransplantation by inhibiting acute rejection.

OBJECTIVE: Preventing and reducing allograft rejection play a far more important role in limb allotransplantation. We previously found L6H21 could inhibit LPS-induced (lipopolysaccharide LPS) overexpression inflammatory factors in macrophages and specifically targets to MD-2 (myeloid differential protein-2 MD-2) required for TLR4 (Toll-like receptor 4 TLR4) activation and represented an important therapeutic target in inflammatory disorders. Therefore, we evaluated the effect and explored the mechanism of L6H21 in rats' limb allograft model. MATERIALS AND METHODS: The efficacy of L6H21 was evaluated in limb allograft rats and cyclosporine (CY-A) was used as a positive control agent. T-Lymphocyte in blood was analyzed and dendritic cells (DCs) separated from spleens using flow cytometry. ELISA was used to measure serum cytokine levels. Analysis of protein expressions was performed using Western blotting. RESULTS: L6H21 reduced the risk of acute rejection and prolonged survival of limb allograft rats. At 3 d and 5 d post-transplant, the ratio of CD4+/CD8+ was decreased in L6H21 group. L6H21 suppressed the content of IL-1α at 7d, IL-5 and IL-10 at both 3 d and 7 d after transplantation. L6H21 decreased the protein expressions of IRF3, p-IRF3, P38, p-P38 and p-IκBα while increased IκBα expression and decreased the ratio of p-IRF3/ IRF3, p-P38/ P38, p-IκBα/IκBα correspondingly. CONCLUSIONS: L6H21 could reduce the risk of acute rejection and prolong the survival of limb allograft rats through inhibiting the ratio of CD4+/CD8+ in blood and serum cytokine levels and suppressing protein expressions of IRF3, p-IRF3, P38, p-P38 and p-IκBα in DCs. So, it may serve as a potential candidate for the treatment of allograft rejection.

Oxidation of plasma proteins is not increased after supplementation with eicosapentaenoic and docosahexaenoic acids.

BACKGROUND: It is generally thought that as the intake of dietary polyunsaturated fatty acids increases, so should that of alpha-tocopherol, to protect the polyunsaturated fatty acids from increased in vivo peroxidation. However, there are little quantitative data about the concentration of alpha-tocopherol that is necessary when eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are consumed. OBJECTIVE: The purpose of this study was to measure changes produced in 2 indexes of lipid oxidation after supplementation with EPA and DHA from fish oil and 3 doses of RRR-alpha-tocopheryl acetate in postmenopausal women. DESIGN: Daily supplements of fish oil providing 2.5 g EPA and 1.8 g DHA and 0, 100, 200, or 400 mg alpha-tocopheryl acetate were given to 46 postmenopausal women in a 4-treatment, 4-period crossover design. RESULTS: The supplements increased plasma concentrations of EPA, DHA, and alpha-tocopherol. The fish-oil supplement increased the plasma concentration of thiobarbituric acid-reactive substances (TBARS) (P: = 0.0001) but not that of oxidatively modified protein, as indicated by the carbonyl content. The alpha-tocopheryl acetate and fish-oil supplements had no significant effect on plasma concentrations of TBARS or oxidized protein. CONCLUSIONS: Although these data show a small but statistically significant increase in oxidative stress on the basis of plasma TBARS concentrations after the consumption of EPA and DHA, the clinical relevance of this change is questionable. In addition, as supplements of alpha-tocopheryl acetate were added to the diet, neither the plasma TBARS concentration nor the protein oxidation changed. Consequently, the results of this study indicate that there is no basis for vitamin E supplementation after consumption of EPA and DHA.

Effects of interaction of RRR-alpha-tocopheryl acetate and fish oil on low-density-lipoprotein oxidation in postmenopausal women with and without hormone-replacement therapy.

We evaluated the effects of RRR-alpha-tocpheryl acetate (alpha-tocopheryl acetate) and hormone-replacement therapy (HRT) on the oxidative susceptibility of low-density lipoprotein (LDL) in postmenopausal women consuming a fish oil supplement. The independent effect of fish oil was also assessed. Forty-eight women, equally divided between women using and not using HRT, participated in a double-blind crossover trial. Each of the four periods lasted 5 wk and was followed by a 4-wk washout interval. During each period all subjects were given a 15-g supplement of fish oil and either 0 (placebo), 100, 200, or 400 mg alpha-tocopheryl acetate daily. LDL resistance to oxidative modification was assessed by calculating lag time, propagation rate, and maximum production of conjugated dienes. Supplementation with fish oil and placebo shortened lag time and slowed propagation rate in women both using and not using HRT. After subjects consumed fish oil, supplementation with alpha-tocopheryl acetate increased plasma and LDL alpha-tocopherol contents significantly and lengthened lag time (at even the lowest concentration) but had no significant effect on propagation rate or maximum production compared with values measured after consumption of fish oil alone. Women not using HRT had faster propagation rates and higher maximum production than women using HRT; after supplementation with fish oil and alpha-tocopheryl acetate these differences prevailed. Supplements as low as 100 mg alpha-tocopheryl acetate/d increase the resistance of LDL to oxidation when fish oil supplements are used. HRT and fish oil supplements may independently affect LDL oxidative susceptibility.

Supplementation of postmenopausal women with fish oil rich in eicosapentaenoic acid and docosahexaenoic acid is not associated with greater in vivo lipid peroxidation compared with oils rich in oleate and linoleate as assessed by plasma malondialdehyde and F(2)-isoprostanes.

BACKGROUND: Although the replacement of dietary saturated fat with unsaturated fat has been advocated to reduce the risk of cardiovascular disease, diets high in polyunsaturated fatty acids (PUFAs) could increase lipid peroxidation, potentially contributing to the pathology of atherosclerosis. OBJECTIVE: The objective of this study was to examine indexes of in vivo lipid peroxidation, including free F(2)-isoprostanes, malondialdehyde (MDA), and thiobarbituric acid reacting substances (TBARS), in the plasma of postmenopausal women taking dietary oil supplements rich in oleate, linoleate, and both eicosapentaenoic acid and docosahexaenoic acid. DESIGN: Fifteen postmenopausal women took 15 g sunflower oil/d, providing 12.3 g oleate/d; safflower oil, providing 10.5 g linoleate/d; and fish oil, providing 2.0 g EPA/d and 1.4 g DHA/d in a 3-treatment crossover trial. RESULTS: Plasma free F(2)-isoprostane concentrations were lower after fish-oil supplementation than after sunflower-oil supplementation (P: = 0.003). When plasma free F(2)-isoprostane concentrations were normalized to plasma arachidonic acid concentrations, significant differences among the supplements were eliminated. Plasma MDA concentrations were lower after fish-oil supplementation than after sunflower-oil supplementation (P: = 0.04), whereas plasma TBARS were higher after fish-oil supplementation than after sunflower oil (P: = 0.003) and safflower oil (P: = 0.001) supplementation. When plasma MDA concentrations were normalized to plasma PUFA concentrations, significant differences were eliminated, but TBARS remained higher after fish-oil supplementation than after sunflower oil (P: = 0.01) and safflower-oil (P: = 0.0003) supplementation. CONCLUSIONS: With fish-oil supplementation, there was no evidence of increased lipid peroxidation when assessed by plasma F(2)-isoprostanes and MDA, although plasma TBARS was higher than with sunflower-oil and safflower-oil supplementation.

Influence of long-chain polyunsaturated fatty acids on oxidation of low density lipoprotein.

Enrichment of low density lipoprotein (LDL) with long-chain fatty acids, such as eicosapentaenoic acid (EPA; 20:5 n-3) and docosahexaenoic acid (DHA; 22:6 n-3) found in fish oil, is thought to increase its oxidative susceptibility although such an increase has not been clearly demonstrated. The purpose of this study was to determine the composition and fatty acid concentration of LDL obtained from postmenopausal women given a supplement of fish oil and relate these values to its oxidative susceptibility. Fish oil supplementation significantly increased LDL concentration of EPA (P = 0.0001) and DHA (P = 0.0001) and decreased that of linoleic acid P = 0.006). The concentration of free cholesterol, cholesterol ester, phospholipids and protein was unchanged while triglyceride concentration increased 8% (P = 0.02). Cu2+-mediated oxidation resulted in a shorter lag time, slower oxidation rate and similar concentrations of conjugated dienes of EPA/DHA-enriched LDL than EPA/DHA-unenriched LDL. Stepwise multiple regression indicated that the primary predictor of oxidative susceptibility of LDL was linoleic acid, even after enrichment with EPA and DHA. The oxidation rate of EPA/DHA-unenriched LDL correlated with the cholesteryl ester concentration (P = 0.003) while that of EPA/DHA-enriched correlated with the concentration of phospholipids (P = 0.03). These data suggest that EPA/DHA-enriched LDL have decreased oxidative susceptibility and that surface lipids may mediate its rate of oxidation.

Selenium supplementation of Chinese women with habitually low selenium intake increases plasma selenium, plasma glutathione peroxidase activity, and milk selenium, but not milk glutathione peroxidase activity.

Twenty-one pregnant women living in Xichang County, China, a selenium-deficient area, were divided into two groups and given either a placebo (n = 10) as yeast or selenium-enriched yeast tablets (n = 11) to provide 100 microg selenium per day. This supplementation was begun the last trimester of pregnancy and continued for 3 months after parturition. Plasma selenium levels and glutathione peroxidase (GPX) activity steadily declined in supplemented women, but a curvilinear response occurred in milk selenium and GPX activity in both supplemented and deficient women and in plasma selenium and GPX activity in deficient women. The milk selenium levels were higher in supplemented women but there were no differences in the milk GPX activity between the two groups of women. The plasma alpha-tocopherol concentrations declined after parturition in both groups but no differences were found between the two groups of women. Plasma thiobarbituric acid reactive substances declined in supplemented women but showed a curvilinear response in unsupplemented women, suggesting peroxidative stress in these women. GPX, selenium, and peroxidative responses in plasma and milk following parturition is advocated as a new method to assess selenium status of lactating women.

Effect of dietary n-6-to-n-3 fatty acid ratio on complete blood and total white blood cell counts, and T-cell subpopulations in aged dogs.

OBJECTIVE: To determine effect of diets with variable n-6-to-n-3 fatty acid (FA) ratio on CD4+ and CD8+ T-lymphocyte subpopulations, and on results of routine laboratory analyses (CBC and total WBC count, serum biochemical analyses, and urinalysis). ANIMALS: 20 healthy, aged (9.5 to 11.5 years old) female Beagles. PROCEDURE: Dogs were fed 1 of 3 diets that contained 6% fat by weight but differed in amounts of n-6 and n-3 FA. For 11 weeks, 6 dogs were fed a low concentration of n-3 FA (ratio, 31:1), 7 were fed a medium concentration (5.4:1), and 7 were fed a high concentration (1.4:1). Preprandial blood and urine samples were collected before beginning the study and at 8 weeks for evaluation of laboratory variables. Before and at 3, 6, and 8 weeks during the study, blood was drawn for total WBC and lymphocyte counts and for characterization of T-cell subpopulations. At 8 and 10 weeks, dogs were vaccinated with keyhole limpet hemocyanin suspension. Blood was drawn 4 days after each vaccination, and lymphocytes were isolated for flow cytometry. Effects of diet and vaccination on each variable were determined. RESULTS: After vaccination, total lymphocyte count increased and CD4+ T lymphocyte count and the CD4(+)-to-CD8+ ratio decreased in dogs consuming the diet with n-6-to-n-3 FA ratio of 1.4:1. CONCLUSION: Feeding a diet with n-6-to-n-3 FA ratio of 1.4:1 had significant effects on CD4+ T lymphocytes in healthy, aged Beagles after vaccination.