Biomedical subjects

Z Cheng

Publications and source records attributed to Z Cheng.

At least 19 recordsLinked to original sources

PubMed2006

Patterns of lateral pelvic lymph node metastases and micrometastases for patients with lower rectal cancer.

AIMS: We aimed at investigating the patterns of lymph node metastases and micrometastases in regions of lateral pelvic area, examining circumferential margin involvement and clarifying their prognostic significance. METHODS: Large tissue slice and tissue array were adopted in the study of 67 patients with AJCC stages I-III lower rectal cancer who underwent total mesorectal excision with systematic lateral pelvic dissection. The outcomes were followed. RESULTS: Altogether, 726 lateral lymph nodes were examined, with 32 and 38 were involved by tumor metastases and micrometastases, respectively. Fifty-eight (82.9%) of the involved lymph nodes were smaller than 5mm. Status of lateral nodes was related to that of mesorectal ones. Middle rectal root (45.5%), internal iliac (31.8%) and obturator (22.7%) regions were more likely to be involved by metastases. Patients with lateral metastases, similar to the group with micrometastases, suffered more recurrence and poorer survival when compared with the ones without metastases. The occurrence of circumferential margin involvement suggested poor prognosis and was related to lateral node status. CONCLUSIONS: In lateral pelvic area, the majority of lymph nodes harboring tumor were small and could easily be neglected by conventional examination. Incidence of lateral metastases differed among regions, thus more attention should be given to the clearance of the highly occurred areas. More extensive range of dissection and/or adjuvant therapy was recommended for patients with lateral node metastases, micrometastases and circumferential margin involvement, since they predisposed poor prognosis.

Adenocarcinoma↗

PubMed2006

Treatment of early mixed cellular and humoral renal allograft rejection with tacrolimus and mycophenolate mofetil.

This prospective study investigated the efficiency of the tacrolimus (Tac) combined with mycophenolate mofetil (MMF) alone without immunoadsorption (IA) or plasmapheresis (PPH) as treatment for early (within 2 weeks) acute humoral rejection (AHR) in non-sensitized renal allograft recipients. Of 160 patients enrolled in this prospective study, 11 patients had histologically and clinically confirmed early steroid-resistant acute rejection with an antibody response and received Tac-MMF therapy. No other aggressive rescue methods such as IA, PPH were used, according to the study design. Patients (n=11) were followed for 13.8+/-3.5 months; nine were females. The complement-dependent cytotoxicity crossmatch was negative before transplantation in all patients and only positive for panel-reactive antibody in one patient. Most of the rejection episodes were mixed with cellular rejection (four patients met Banff IIA criteria, five patients met Banff IIB, one patient met Banff IB, and one patient met Banff borderline). After 16.19+/-6.16 days of treatment, all rejection episodes were successfully reversed and all graft functions were stable, with a mean serum creatinine level of 1.12+/-0.32 mg/dl during follow-up. No patient suffered from severe infectious complications (except one case of urinary infection). Our investigation suggests that Tac combined with MMF alone is adequate to reverse early mixed cellular and humoral C4d-positive rejection in non-sensitized renal allograft recipients.

Acute Disease↗

PubMed2006

Differences between primiparous and multiparous dairy cows in the inter-relationships between metabolic traits, milk yield and body condition score in the periparturient period.

During the early postpartum period dairy cows mobilize fat and muscle to support lactation. This is associated with alterations in blood metabolite and hormone profiles which in turn influence milk yield and fertility. This study developed models to determine how metabolic traits, milk yield and body condition score were inter-related at different times in the periparturient period and to compare these relationships in primiparous (PP, n=188) and multiparous (MP, n=312) cows. Data from four previous studies which included information on blood metabolic parameters, parity, milk yield, body condition score and diet were collated into a single dataset. Coefficients of polynomial equations were calculated for each trait between -1 week pre-calving and week +7 postpartum using residual maximum likelihood modelling. The completed dataset was used in a multiple correlation model to determine how the best fit curves were related to each other over time. PP cows had higher concentrations of insulin-like growth factor-I and lower beta-hydroxybutyrate concentrations throughout, higher leptin concentrations pre-partum and both the peak in non-esterified fatty acids and the nadir in urea concentration occurred earlier after calving. These differences were associated with significantly lower milk production. Leptin concentrations fell at calving and were related to body condition score. Insulin was negatively correlated with yield in MP cows only. In MP cows the relationship between insulin-like growth factor-I and yield switched from negative to positive between weeks +4 and +7. Both beta-hydroxybutyrate and urea were positively related to yield in PP cows. In contrast, in MP cows beta-hydroxybutyrate was negatively correlated with yield and urea was strongly related to body condition score but not yield. These results suggest that there are differences in the control of tissue mobilization between PP and MP cows which may promote nutrient partitioning into growth as well as milk during the first lactation.

3-Hydroxybutyric Acid↗

PubMed2006

Impact of irrigating rice paddies with groundwater containing arsenic in Bangladesh.

Soil and soil-water As profiles were obtained from 4 rice paddies in Bangladesh during the wet growing season (May-November), when surface water with little arsenic is used for irrigation, or during the dry season (January-May), when groundwater elevated in arsenic is used instead. In the upper 5 cm of paddy soil, accumulation of 13+/-12 mg/kg acid-leachable As (n=11) was observed in soil from 3 sites irrigated with groundwater containing 80-180 microg/L As, whereas only 3+/-2 mg/kg acid-leachable As (n=8) was measured at a control site. Dissolved As concentrations averaged 370+/-340 microg/L (n=7) in the upper 5 cm of the soil at the 3 sites irrigated with groundwater containing 80-180 microg/L As, contrasting with soil water As concentrations of only 18+/-7 microg/L (n=4) over the same depth interval at the control site. Despite the accumulation of As in soil and in soil water attributable to irrigation with groundwater containing elevated As levels, there is no evidence of a proportional transfer to rice grains collected from the same sites. Digestion and analysis of individual grains of boro winter rice from the 2 sites irrigated with groundwater containing 150 and 180 microg/L As yielded concentrations of 0.28+/-0.13 mg/kg (n=12) and 0.44+/-0.25 mg/kg (n=12), respectively. The As content of winter rice from the control site was not significantly different though less variable (0.30+/-0.07; n=12). The observations suggest that exposure of the Bangladesh population to As contained in rice is less of an immediate concern than the continued use of groundwater containing elevated As levels for drinking or cooking, or other potential consequences of As accumulation in soil and soil-water.

Agriculture↗

PubMed2005

Limited temporal variability of arsenic concentrations in 20 wells monitored for 3 years in Araihazar, Bangladesh.

Millions of people in Bangladesh have probably switched their water consumption to wells that meet the local standard for As in drinking water of 50 microg/L as a result of blanket field testing throughout the country. It is therefore important to know if As concentrations in those wells could change over time. To address this issue, we report here precise groundwater As analyses for time-series samples collected from a suite of 20 tube wells containing < or =50 microg/L As and ranging from 8 to 142 m in depth. For 17 out of 20 wells, the standard deviation of groundwater As concentrations was <10 microg/L over the 3-year monitoring period (n = 24-44 per well). Six of the 17 wells are community wells, each of which serves the needs of several hundred people in particularly affected villages. Of the three wells showing larger fluctuations in chemical composition including As, two are very shallow (8 and 10 m). Variations in As concentrations for one of these wells (50 +/- 32 microg/L, n = 36), as well as another shallow well showing smaller variations (48 +/- 5 microg/L, n = 36), appear to be coupled to seasonal precipitation and recharge linked to the monsoon. The other shallow well showing larger variations in composition indicates a worrisome and steady increase in As concentrations from 50 to 70 microg/L (n = 36) over 3 years. The time series of As (30 +/- 11 microg/L, n = 24) and other constituents in one deep community well (59 m) show large fluctuations that suggest entrainment of shallow groundwater through a broken PVC pipe. Even though the majority of wells that were initially safe remained so for 3 years, our results indicate that tube wells should be tested periodically.

Arsenic↗

PubMed2005

Potential for improving bioavailable zinc in wheat grain (Triticum species) through plant breeding.

A "whole-body" radioassay procedure was used to assess retention and absorption by rats of Zn in mature kernels of whole grain wheat harvested from 28 genotypes (Triticum spp.) grown in nutrient solution supplied with 2 microM ZnSO4 radiolabeled with 65Zn. Grain-Zn concentration differed among genotypes and ranged from 33 to 149 microg g(-1) of dry weight (DW); similarly, grain-Fe concentration varied approximately 4-fold, from 80 to 368 microg g(-1) of DW. Concentrations of Zn and Fe in the grain were positively correlated. Therefore, selecting genotypes high in grain-Zn also tends to increase grain-Fe concentration. Concentrations of myo-inositolhexaphosphate (phytate) in the wheat grain varied from 8.6 to 26.1 micromol g(-1) of DW. Grain intrinsically labeled with 65Zn was incorporated into test meals fed to Zn-depleted rats. All rats readily ate the test meals, so that Zn intake varied directly with grain-Zn concentration. As determined by the percentage of 65Zn absorbed from the test meal, the bioavailability to rats of Zn in the wheat genotypes ranged from about 60 to 82%. The amount of bioavailable Zn (micrograms) in the grain was positively correlated to the amount of Zn accumulated in the grain. There was a significant negative correlation between grain-phytate levels and percentage of Zn absorbed from the wheat grain, but the effect was not large. These results demonstrate that concentrations of Zn in whole-wheat grain, as well as amounts of bioavailable Zn in the grain, can be increased significantly by using traditional plant-breeding programs to select genotypes with high grain-Zn levels. Increasing the amount of Zn in wheat grain through plant-breeding contrivances may contribute significantly to improving the Zn status of individuals dependent on whole grain wheat as a staple food.

Animals↗

PubMed2005

Reliability of a commercial kit to test groundwater for arsenic in Bangladesh.

A comparison of field and laboratory measurements of arsenic in groundwater of Araihazar, Bangladesh, indicates that the most widely used field kit correctly determined the status of 88% of 799 wells relative to the local standard of 50 microg/L As. Additional tests showthatthe inconsistencies, mainly underestimates in the 50-100 microg/L As range, can be avoided by increasing the reaction time from 20 to 40 min. Despite this limitation, the field data already compiled for millions of wells by the Bangladesh Arsenic Mitigation and Water Supply Project, in combination with information on well location and depth, should prove to be extremely useful to prioritize interventions in thousands of affected villages.

Arsenic↗

PubMed2005

Identification of discrete chromosomal deletion by binary recursive partitioning of microarray differential expression data.

DNA copy number abnormalities (CNA) are characteristic of tumours, and are also found in association with congenital anomalies and mental retardation. The ultimate impact of copy number abnormalities is manifested by the altered expression of the encoded genes. We previously developed a statistical method for the detection of simple chromosomal amplification using microarray expression data. In this study, we significantly advanced those analytical techniques to allow detection of localised chromosomal deletions based on differential gene expression data. Using three cell lines with known chromosomal deletions as model system, mRNA expression in those cells was compared with that observed in diploid cell lines of matched tissue origin. Results show that genes from deleted chromosomal regions are substantially over-represented (p<0.000001 by chi2) among genes identified as underexpressed in deletion cell lines relative to normal matching cells. Using a likelihood based statistical model, we were able to identify the breakpoint of the chromosomal deletion and match with the karyotype data in each cell line. In one such cell line, our analyses refined a previously identified 10p chromosomal deletion region. The deletion region was mapped to between 10p14 and 10p12, which was further confirmed by subtelomeric fluorescence in situ hybridisation. These data show that microarray differential expression data can be used to detect and map the boundaries of submicroscopic chromosomal deletions.

Cell Line↗

PubMed2005

The effect of a diet supplemented with the n-6 polyunsaturated fatty acid linoleic acid on prostaglandin production in early- and late-pregnant ewes.

Polyunsaturated fatty acids derived from the diet are incorporated into cell membranes where they act as precursors for prostaglandin (PG) synthesis. Linoleic acid (LA; 18:2 n-6) is a major constituent of plant oils and its consumption in Westernized populations is increasing. This study investigated the influence of LA on PG production by the uterus and placenta. Pregnant ewes were fed a control or an LA-enriched diet. Oxytocin (OT) was injected on day 45 (early) or day 133 (late) of gestation to measure the release of 13,14-dihydro-15-keto PGF(2alpha) (PGFM). Ewes were killed on day 46 or day 138 for collection of uterine intercaruncular endometrium and fetal allantochorion. Basal and stimulated PG release from explant cultures was assessed before and after in vitro treatment with OT, lipopolysaccharide (LPS), dexamethasone (DEX) or calcium ionophore (CaI). Expression of cyclooxygenase (COX)-1 and COX-2 was determined by Western blot in endometrium of late-gestation ewes. Circulating PGFM levels in vivo did not differ according to diet but there were highly significant differences in the release of PGs in vitro. Basal production of PGF(2alpha)and PGE(2) by the endometrium and of PGE(2) by the allantochorion were all higher in tissues from LA-supplemented ewes. Endometrial tissues produced more PG following OT and CaI treatment, whereas DEX inhibited production of both PGs at both stages of gestation. In allantochorion collected at day 46 LPS did not significantly alter PGE(2) release and DEX increased output, whereas at day 138 LPS was stimulatory but DEX was inhibitory. These data show that a high-LA diet can significantly increase the ability of both endometrium and placental tissues to produce PGs in vitro. This effect of diet may only become apparent after a sustained period of PG release, so was not seen following the brief pulse caused by OT treatment in vivo. As COX protein levels were unaltered, the main influence was likely to be via conversion of LA to arachidonic acid, providing an increased supply of precursor. These results support previous studies which suggest that alterations in dietary polyunsaturated fatty acids may influence the time of labour.

Animals↗

PubMed2004

Testing groundwater for arsenic in Bangladesh before installing a well.

Profiles of groundwater and sediment properties were collected at three sites in Bangladesh with an inexpensive sampling device that is deployed by modifying the local manual drilling method. Dissolved As concentrations in the groundwater samples ranging from 5 to 600 microg/L between 5 and 50 m depth closely matched vertical profiles from nearby nests of monitoring wells. In combination with a field kit, the device provides a means of targeting aquifers for the installation of tube wells that meet the drinking water standard for As. The device is also a useful research tool for unraveling the relationships between the As content of groundwater and the complex structure of flood plain and deltaic environments throughout South Asia.

Arsenic↗

PubMed2004

Relationships between the plasma concentrations of insulin-like growth factor-I in dairy cows and their fertility and milk yield.

The relationships between insulin-like growth factor-I (IGF-I) and the fertility and milk yield of Holstein-Friesian dairy cows were investigated. The concentration of IGF-I in blood was measured weekly from one week before to 12 weeks after calving in 177 multiparous cows and at four times during this period in 142 primiparous cows; the concentration of IGF-I in milk was measured in 50 of the multiparous cows. The plasma concentrations of IGF-I were higher in the primiparous than in the multiparous animals. In the primiparous cows, high concentrations of IGF-I before calving were associated with longer calving to conception intervals. Conversely, in the multiparous cows low concentrations of IGF-I before and after calving were associated with a failure to conceive, despite repeated services. Multiparous cows with IGF-I concentrations of greater than 25 ng/ml in the week after calving were 11 times more likely to conceive to first service than those with lower concentrations. Concentrations of IGF-I greater than 50 ng/ml at first service increased the likelihood of conception five-fold. Cows with higher peak milk yields had lower plasma concentrations of IGF-I and took longer to return to ovarian cyclicity. The negative relationship between milk yield and return to cyclicity was stronger in the multiparous cows (P < 0.002) than in the primiparous cows (P < 0.04). The concentrations of IGF-I in milk followed a different pattern and were not associated with the changes in plasma IGF-I or fertility.

Animals↗

PubMed2004

Raised dietary n-6 polyunsaturated fatty acid intake increases 2-series prostaglandin production during labour in the ewe.

Preterm labour is the major cause of perinatal morbidity and mortality in humans. The incidence is around 10% and the causes are often unknown. Consumption of dietary n-6 polyunsaturated fatty acids (PUFAs) in western societies is increasing. These are metabolized to arachidonic acid, the precursor for 2-series prostaglandins (PGs), major signalling molecules during labour. This study investigated the effect of dietary supplementation with linoleic acid (LA, 18: 2, n-6) on parturition. Ewes were fed a control or LA-supplemented diet from 100 days gestation. Labour was induced using a standardized glucocorticoid challenge (dexamethasone, Dex) to the fetus, starting on day 139. Electromyographic (EMG) activity and fetal and maternal circulating PG concentrations were monitored. One third of LA-fed ewes delivered early (pre-Dex) although basal uterine EMG activity preceding Dex was higher in control ewes (P < 0.05). A steep increase in EMG activity occurred 18-38 h after the start of Dex infusion. Twice basal EMG activity (defined as established labour) occurred on average 7 h earlier in the LA-supplemented ewes (P < 0.05). The basal concentrations of maternal and fetal PGFM and fetal PGE(2) were approximately doubled in LA-supplemented ewes before the start of Dex infusion (P < 0.01). The rise in fetal PGE(2) and maternal oestradiol concentrations post-Dex occurred earlier in the LA-supplemented ewes. All PG measurements remained significantly higher in the LA-supplemented ewes during labour onset. This study suggests that consumption of a high LA diet in late pregnancy can enhance placental PG production and may thus increase the risk of preterm labour.

Animals↗

PubMed2004

Laparoscopic versus open total mesorectal excision with anal sphincter preservation for low rectal cancer.

BACKGROUND: The Laparoscopic approach has been applied to colorectal surgery for many years; however, there are only a few reports on laparoscopic low and ultralow anterior resection with construction of coloanal anastomosis. This study compares open versus laparoscopic low and ultralow anterior resections, assesses the feasibility and efficacy of the laparoscopic approach of total mesorectal excision (TME) with anal sphincter preservation (ASP), and analyzes the short-term results of patients with low rectal cancer. METHODS: We analyzed our experience via a prospective, randomized control trail. From June 2001 to September 2002, 171 patients with low rectal cancer underwent TME with ASP, 82 by the laparoscopic procedure and 89 by the open technique. The lowest margin of tumors was below peritoneal reflection and 1.5-8 cm above the dentate line (1.5-4.9 cm in 104 cases and 5-8 cm in 67 cases). The grouping was randomized. RESULTS: Results of operation, postoperative recovery, and short-term oncological follow-up were compared between 82 laparoscopic procedures and 89 controls who underwent open surgery during the same period. In the laparoscopic group, 30 patients in whom low anterior resection was performed had the anastomosis below peritoneal reflection and more than 2 cm above the dentate line, 27 patients in whom ultralow anterior resection was performed had anastomotic height within 2 cm of the dentate line, and 25 patients in whom coloanal anastomosis was performed had the anastomosis at or below the dentate line. In the open group, the numbers were 35, 27, and 27, respectively. There was no statistical difference in operation time, administration of parenteral analgesics, start of food intake, and mortality rate between the two groups. However, blood loss was less, bowel function recovered earlier, and hospitalization time was shorter in the laparoscopic group. CONCLUSION: Totally laparoscopic TME with ASP is feasible, and it is a minimally invasive technique with the benefits of much less blood loss during operation, earlier return of bowel function, and shorter hospitalization.

Adult↗

PubMed2004

Rapid multi-element analysis of groundwater by high-resolution inductively coupled plasma mass spectrometry.

A rapid and sensitive method was developed to determine, with a single dilution, the concentration of 33 major and trace elements (Na, Mg, Si, K, Ca, Li, Al, P, S, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Sr, Mo, Cd, In, Sn, Sb, Cs, Ba, Re, Hg, Pb, Bi, U) in groundwater. The method relies on high-resolution inductively coupled plasma mass spectrometry (HR ICP-MS) and works across nine orders of magnitude of concentrations. For most elements, detection limits for this method are considerably lower than methods based on quadrupole ICP-MS. Precision was within or close to +/-3% (1 sigma) for all elements analyzed, with the exception of Se (+/-10%) and Al (+/-6%). The usefulness of the method is demonstrated with a set of 629 groundwater samples collected from tube wells in Bangladesh (Northeast Araiharzar). The results show that a majority of tube well samples in this area exceed the WHO guideline for As of 10 microg L(-1), and that those As-safe wells frequently do not meet the guideline for Mn of 500 microg L(-1) and U of 2 microg L(-1).

Bangladesh↗

PubMed2004

GNB3 gene C825T and ACE gene I/D polymorphisms in essential hypertension in a Kazakh genetic isolate.

The Kazakh inhabitants living in Barkol pasture of northeast China belong to a genetic isolate characterized by ethnically homogeneous and a communal pastoral lifestyle. To investigate whether the polymorphisms in the G-protein beta-3 subunit (GNB3) gene and angiotensin-converting enzyme (ACE) gene are associated with essential hypertension (EH), we carried out a case-control study of 290 hypertensive subjects and 244 normotensive (NT) controls randomly selected from Kazakh populations of Barkol. A previous medical history of diabetes and hypertension, and body mass index (BMI) was recorded. Plasma glucose, triglyceride, and cholesterol were measured. The insertion/deletion (I/D) polymorphism of the ACE gene and the C825T polymorphism of the GNB3 gene were determined by the polymerase chain reaction (PCR) technique. The distributions of genotypes and alleles for the two polymorphisms did not differ significantly between the case and control populations, and odds ratio of EH related to the ACE gene D allele and GNB3 gene T allele was not significantly different from 1.0. Logistic regression analysis shows the variation at the GNB3 and ACE did not have any statistically significant synergistic effect on blood pressure (BP). Stratification of NT and untreated hypertensives according to I/D polymorphism of ACE gene and C825T polymorphism of GNB3 gene disclosed no significant difference across genotypes with respect to BMI, glucose, triglyceride, cholesterol, systolic and diastolic BP. In conclusion, the polymorphisms in the GNB3 gene and ACE gene, solely or combined, did not confer a significantly increased risk for the development of EH in the Kazakh isolate of northeast China.

Adult↗

PubMed2004

Alteration of prostaglandin production and agonist responsiveness by n-6 polyunsaturated fatty acids in endometrial cells from late-gestation ewes.

We investigated the effect of n-6 polyunsaturated fatty acids (PUFAs) on prostaglandin (PG) production by the uterus. A mixed population of endometrial cells (epthelium and stroma) from late-gestation ewes were cultured in defined medium containing linoleic acid (LA, 18:2, n-6), gamma-linolenic acid (GLA, 18:3, n-6) or arachidonic acid (AA, 20:4, n-6) in concentrations of 0 (control), 20 or 100 microM. After 45 h in test medium with or without added PUFAs, cells were challenged with control medium (CM), oxytocin (OT, 250 nM), lipopolysaccharide (LPS, 0.1 micro g/ml) or dexamethasone (DEX, 5 microM) for 22 h in the continued presence of the same concentration of PUFA and the medium was collected for measurement of PGF(2alpha) and PGE(2). Supplementation with LA inhibited the production of PGF(2alpha) but did not alter PGE(2), whereas GLA and AA increased production of both PGs. All PUFA supplements thus increased the ratio of PGE(2) to PGF(2alpha) (E:F ratio) two- to threefold. In control cells, OT and LPS challenges stimulated the production of PGF(2alpha) and PGE(2). In all challenge groups, the concentrations of PGF(2alpha) in response to PUFAs followed the same pattern - LA<control<GLA<AA - but there were significant alterations in responsiveness as a result of PUFA treatment. In the cells supplemented with 100 microM AA, there was no further increase in PGF(2alpha) output in the presence of OT or LPS and when 100 microM GLA was present neither LPS nor OT stimulated PGE(2) significantly. When LPS was given to AA-supplemented cells, the E:F ratio was increased. DEX did not change PGE(2) production in control or LA-treated cells, but the cells produced significantly less PGF(2alpha), so the E:F ratio was increased. In contrast, in GLA- and AA-treated cells, DEX reduced the production of both PGF(2alpha) and PGE(2), so the E:F ratio was unaltered. In summary, the study showed altered production of PGs in the presence of different PUFAs according to their position in the n-6 metabolic pathway. The type of PUFA present affected responsiveness to OT, LPS and DEX and also changed the ratio of PGE(2) to PGF(2alpha) produced. The possible implications of this work are discussed in relation to the effect of diet on term and pre-term labour, which both require upregulation of the endometrial PG synthetic pathway.

Animals↗

PubMed2003

Effects of conjugated linoleic acid on prostaglandins produced by cells isolated from maternal intercotyledonary endometrium, fetal allantochorion and amnion in late pregnant ewes.

The anticarcinogenic properties of conjugated linoleic acid (CLA) are, at least partially, attributed to its ability to interrupt the n-6 polyunsaturated fatty acid (PUFA) metabolic pathway for the biosynthesis of eicosanoids, including prostaglandins (PG). Both PGE(2) and PGF(2alpha) play key roles in parturition. In the present study, we compared the effects of CLA (a mixture of cis- and trans-9, 11- and -10, 12-octadecadienoic acid) and linoleic acid (LA) on PG production by cells isolated from maternal intercotyledonary endometrium, fetal allantochorion and amnion from late pregnant ewes. The results demonstrated that supplementation of LA and CLA significantly affected both the proportions and the amounts of PGs produced by all three tissue types. The ability of the uterus and placenta to respond to oxytocin (OT, endometrium only) and lipopolysaccharide (LPS) was also affected. LA inhibited PGE(2) and PGF(2alpha) production in the absence or presence of either oxytocin or LPS. In endometrial cells with or without oxytocin or LPS, CLA dose-dependently suppressed PGF(2alpha) generation, whereas low doses of CLA (20 microM) increased PGE(2) generation. Supplementation with CLA therefore increased the PGE(2)/PGF(2alpha) ratio in the endometrial cells. These results suggest that dietary supplementation of LA or CLA may affect both the initiation and progression of parturition.

Allantois↗

PubMed2003

Iron and zinc absorption from two bean (Phaseolus vulgaris L.) genotypes in young women.

Extrinsic and intrinsic iron and zinc labels were used to test iron and zinc absorption from two bean (Phaseolus vulgaris) genotypes, containing normal (common beans, CB) or higher (HFeZnB) iron and zinc concentrations, fed in single meals to young women with low iron reserves. The women were divided into two groups, with one receiving a CB test meal (n = 12) and the other, an HFeZnB test meal (n = 11). The beans were intrinsically labeled hydroponically with (55)Fe (CB and HFeZnB) and with (70)Zn (HFeZnB). Concentrations of zinc and iron were 98 and 65% higher, respectively, in HFeZnB as compared to CB, but phytic acid contents were similar. Extrinsic labels were (59)Fe (CB and HFeZnB), (67)Zn (CB), and (68)Zn (HFeZnB). Iron and zinc percent absorption levels were calculated from radio-iron activity in red blood cells and from urinary excretion of zinc isotopes. Intrinsic and extrinsic iron absorption measures were highly correlated (R (2) = 0.986) (average extrinsic/intrinsic ratio was 1.00). Iron absorption was low (geometric mean < 2%) in both bean types, and total iron absorbed was not different between types. Intrinsic zinc absorption from the HFeZn beans was higher than extrinsic absorption (15.2% vs 13.4%, p < 0.05) (average extrinsic/intrinsic was 0.90). The correlation between intrinsic and extrinsic zinc measures was not as high as that for iron (R (2) = 0.719). Percent zinc absorption levels were similar in both bean types, but total extrinsic zinc absorbed was 90% higher (p < 0.05) from the HFeZnB meal. Thus, the less expensive and time-consuming extrinsic labeling may be used to screen various varieties of beans for iron bioavailability in humans, but it underestimates zinc absorption by approximately 10%. Selective breeding for high-zinc bean genotypes may improve zinc status. However, high-iron genotypes appear to have little effect on iron status when fed alone in single meals to women with low iron reserves.

Adult↗