The diets of school-aged Aboriginal youths in Canada: a systematic review of the literature.

BACKGROUND: Most national surveys examining diet leave large segments of the Aboriginal population under-represented. The present study aimed to: (i) review primary research studies that investigated the dietary intakes of Canadian school-aged Aboriginal youths; (ii) summarise the tools and methodologies currently used to measure diet in this population; and (iii) identify knowledge gaps and suggest areas of future research. METHODS: A systematic review of research published between January 2004 and January 2014 related to the diets of Canadian school-aged (6-18 years) Aboriginal youths was undertaken, including Medline, Scopus, ERIC, Web of Science and Google Scholar databases. Studies were summarised based on purpose, year, sample population, setting, dietary assessment method and main findings. RESULTS: Twenty-four studies were reviewed, all of which were cross-sectional in design. Most (n = 16; 67%) were from Ontario or Quebec, investigated the diets of First Nations (n = 21; 88%) youths and took place in remote or isolated settings (n = 18; 75%). Almost all of the studies used the 24-h recall to assess intake (n = 19; 79%), of which 89% used a single recall. The findings suggest that the diets of Aboriginal youths could be improved. Of particular concern are inadequate intakes of vegetables and fruit, milk and alternatives, fibre, folate, vitamin A, vitamin C, calcium and vitamin D, concomitant with an excess consumption of sugar sweetened beverages, snacks and fast foods. Traditional foods remain important but tend to be consumed infrequently. CONCLUSIONS: The diets of Canadian Aboriginal youths are energy-dense and nutrient-poor. The diets of Inuit and Métis youths, in particular, and perceptions of a balanced diet warrant further investigation.

Implementation of a community greenhouse in a remote, sub-Arctic First Nations community in Ontario, Canada: a descriptive case study.

INTRODUCTION: Food insecurity is prevalent in northern communities in Canada and there is a movement to improve food security through both the re-vitalization of traditional harvesting practices as well as through sustainable agriculture initiatives. Gardening in northern communities can be difficult and may be aided by a community greenhouse. The objective of this project was to conduct a descriptive case study of the context and process surrounding the implementation of a community greenhouse in a remote, sub-Arctic First Nations community in Ontario, Canada. METHOD: Data sources included semi-directed interviews with a purposive and snowball sample of key informants (n=14), direct observations (n=32 days), written documentation (n=107), and photo-documentation (n=621 total). Digital photographs were taken by both a university investigator during community visits and a community investigator throughout the entire project. The case study was carried out over 33 months; from early 2009 until October of 2011. Thematic data analyses were conducted and followed a categorical aggregation approach. RESULTS: Categories emerging from the data were appointed gardening-related themes: seasons, fertile ground, sustainability, gardeners, ownership, participant growth, and sunshine. Local champions were critical to project success. Uncertainty was expressed by several participants regarding ownership of the greenhouse; the local community members who championed the project had to emphasize, repeatedly, that it was community owned. Positive outcomes included the involvement of many community members, a host of related activities, and that the greenhouse has been a learning opportunity to gain knowledge about growing plants in a northern greenhouse setting. A strength of the project was that many children participated in greenhouse activities. CONCLUSIONS: Community and school greenhouse projects require local champions to be successful. It is important to establish guidelines around ownership of a greenhouse and suitable procedures for making the building accessible to everyone without compromising security. Implementing a greenhouse project can engage community members, including children, and provide a great learning opportunity for gardeners in a remote, northern community.

Study of psychrophilic and psychrotolerant micro-organisms isolated in cold rooms used for pharmaceutical processing.

AIMS: To examine for psychrophilic or psychrotolerant micro-organisms in pharmaceutical cold rooms (in relation to numbers, incidents and species) and to determine, where such micro-organisms are present, whether standard microbiological environmental monitoring regimes require modification. This is presented as a case study. METHODS AND RESULTS: Comparative environmental monitoring within different pharmaceutical facility cold rooms (using standard mesophilic and low temperature incubation). Data were collected over two periods, 5 years apart. The results indicated that psychrophilic micro-organisms were not present and that those micro-organisms deemed psychrotolerant, primarily pseudomonads, could be grown on standard media under mesophilic conditions. CONCLUSIONS: Psychrophilic micro-organisms were not detected and those considered to be psychrotolerant were only found in low numbers. Pyschrotolerant organisms were recovered under both low temperature incubation conditions and under standard conditions (between 20 and 35°C). Further evaluation may be required, using alternative agar, and microbiologists should regularly review the species recovered to note differences between different environments. SIGNIFICANCE AND IMPACT OF THE STUDY: The study came about from requests made by US and UK regulators concerning the risk of any extremophiles present in pharmaceutical manufacturing facilities upon product safety. Regulators expressed concerns about whether standard, and accepted, environmental monitoring regimes were capable of detecting such micro-organisms. The data provide a benchmark to support pharmaceutical manufacturers in relation to their existing monitoring programmes or as a case study with which to undertake a similar study.

Adiposity is a major determinant of plasma levels of the novel vasodilator hydrogen sulphide.

AIMS/HYPOTHESIS: Hydrogen sulphide is a recently identified endogenous endothelium-dependent vasodilator. Animal models of diabetes have shown that low plasma H(2)S levels are associated with marked endothelial dysfunction and insulin resistance. However, human studies on H(2)S and vascular function in health and disease are lacking. METHODS: Plasma was obtained from male patients with type 2 diabetes (n = 11), overweight (n = 16) and lean (n = 11) volunteers. H(2)S levels were determined by zinc trap spectrophotometry. Anthropometric measurements (BMI/waist:hip ratio), lipid profile, systemic blood pressure, biochemical indices of diabetes (fasting glucose, insulin sensitivity, Hb(1Ac)) and microvascular function (minimum vascular resistance) were determined. RESULTS: Median plasma H(2)S levels (25th, 75th percentiles) in age-matched lean, overweight and type 2 diabetes individuals were 38.9 (29.7, 45.1) micromol/l, 22.0 (18.6, 26.7) micromol/l and 10.5 (4.8, 22.0) micromol/l, respectively. Median plasma H(2)S levels were significantly lower in patients with type 2 diabetes compared with lean (p = 0.001, Mann-Whitney) and overweight participants (p = 0.008). Median plasma H(2)S levels in overweight participants were significantly lower than in lean controls (p = 0.003). Waist circumference was an independent predictor of plasma H(2)S (R (2) = 0.423, standardised beta: -0.650, p < 0.001). This relationship was independent of diabetes, which only contributed a further 5% to the model (R (2) = 0.477). Waist circumference or other measures of adiposity (waist:hip ratio/BMI) remained independent predictors of plasma H(2)S after adjustment for systolic blood pressure, microvascular function, insulin sensitivity, glycaemic control and lipid profile. CONCLUSIONS/INTERPRETATION: Plasma H(2)S levels are reduced in overweight participants and patients with type 2 diabetes. Increasing adiposity is a major determinant of plasma H(2)S levels.

Capillary pressure may predict preclinical changes in the eye.

AIMS/HYPOTHESIS: Microvascular dysfunction is associated with end-organ damage. Macular oedema is an important component of diabetic retinopathy. Macular thickness can be accurately quantified by optical coherence tomography (OCT), enabling accurate assessment of the macular prior to clinically apparent abnormalities. We investigated whether macular (fovea) thickness in non-diabetic individuals is related to the microvascular variables controlling fluid filtration across a blood vessel wall, in particular capillary pressure and the microvascular filtration capacity (Kf). METHODS: We recruited 50 non-diabetic individuals (25 men, 25 women; age range: 26-78 years; BMI range: 20-46 kg/m(2)). Fovea thickness was assessed by OCT. Microvascular assessments included: finger nailfold capillary pressure; Kf; microvascular structural assessments, i.e. skin vasodilatory capacity, minimum vascular resistance (MVR) and microvascular distensibility; and endothelial function. RESULTS: At 214.6 (19.9) microm (mean [SD]), fovea thickness was within normal range. Capillary pressure, adjusted for BMI, was associated with fovea thickness (standardised beta 0.573, p = 0.006, linear regression). Fovea thickness was not associated with Kf, microvascular structural assessments or endothelial function. Capillary pressure was still associated with fovea thickness when adjusted for microvascular variables (Kf, vasodilatory capacity, MVR, microvascular distensibility or endothelial function), or for risk factors for diabetes (systemic blood pressure, insulin sensitivity, inflammation, glycaemic status and lipids) and age. CONCLUSIONS/INTERPRETATION: Capillary pressure, a key determinant of movement of fluid across a blood vessel wall, is associated with fovea thickness in non-diabetic individuals. This suggests that with regard to potential preventative or therapeutic targets, attention should be directed at the mechanisms determining retinal microvascular pressure.

Using zebrafish to assess the effect of chronic, early developmental exposure to environmentally relevant concentrations of 5-fluorouracil and leucovorin.

Environmental contaminants can deleteriously affect aquatic animals. One such contaminant is 5-fluorouracil (5-FU), a long-prescribed chemotherapeutic drug. Leucovorin (LV) is co-administered with 5-FU, potentiating its effects. Zebrafish (Danio rerio) larvae were reared in ng/L treatments of either 5-FU, LV, or a combined 5-FU/LV mixture for 8 dy. Survival was measured daily and swimming behavior assessed every other day. After 8 dy, larval length was measured, and densitometry of p53-labeled cryostat sections determined the extent of apoptosis. No significant differences in survival or apoptosis were found; larvae in the highest concentrations were largest. Changes in behavior of 5-FU-treated larvae were based on exposure duration; changes in LV-treated larvae were affected by drug concentration and duration. Larvae co-exposed to 5-FU/LV had responses like 5-FU-treated larvae. Overall, early developmental exposure of zebrafish larvae to environmentally-relevant concentrations of 5-FU and LV did not adversely affect survival, growth, and behavior suggesting realistic concentrations are sublethal and non-toxic.

The cloned capsaicin receptor integrates multiple pain-producing stimuli.

Capsaicin, the main pungent ingredient in "hot" chili peppers, elicits buming pain by activating specific (vanilloid) receptors on sensory nerve endings. The cloned vanilloid receptor (VR1) is a cation channel that is also activated by noxious heat. Here, analysis of heat-evoked single channel currents in excised membrane patches suggests that heat gates VR1 directly. We also show that protons decrease the temperature threshold for VR1 activation such that even moderately acidic conditions (pH < or = 5.9) activate VR1 at room temperature. VR1 can therefore be viewed as a molecular integrator of chemical and physical stimuli that elicit pain. Immunocytochemical analysis indicates that the receptor is located in a neurochemically heterogeneous population of small diameter primary afferent fibers. A role for VR1 in injury-induced hypersensitivity at the level of the sensory neuron is presented.

ACAT1 and ACAT2 membrane topology segregates a serine residue essential for activity to opposite sides of the endoplasmic reticulum membrane.

A second form of the enzyme acyl-CoA:cholesterol acyltransferase, ACAT2, has been identified. To explore the hypothesis that the two ACAT enzymes have separate functions, the membrane topologies of ACAT1 and ACAT2 were examined. A glycosylation reporter and FLAG epitope tag sequence was appended to a series of ACAT cDNAs truncated after each predicted transmembrane domain. Fusion constructs were assembled into microsomal membranes, in vitro, and topologies were determined based on glycosylation site use and accessibility to exogenous protease. The accessibility of the C-terminal FLAG epitope in constructs was determined by immunofluorescence microscopy of permeabilized transfected cells. Both ACAT1 and ACAT2 span the membrane five times with their N termini in the cytosol and C termini in the ER lumen. The fourth transmembrane domain is located in a different region for each protein, placing the putative active site ACAT1 serine (Ser(269)) in the cytosol and the analogous residue in ACAT2 (Ser(249)) in the ER lumen. Mutation of these serines inactivated the ACAT enzymes. The outcome is consistent with the hypothesis that cholesterol ester formation by ACAT2 may be coupled to lipoprotein particle assembly and secretion, whereas ACAT1 may function primarily to maintain the balance of free and esterified cholesterol intracellularly.

Efficacy of electrotactile vestibular substitution in patients with peripheral and central vestibular loss.

Vestibular dysfunction of either central or peripheral origin can significantly affect balance, posture, and gait. We conducted a pilot study to test the effectiveness of training with the BrainPort balance device in subjects with a balance dysfunction due to peripheral or central vestibular loss. The BrainPort balance device transmits information about the patient's head position via electrotactile stimulation of the tongue. Head position data is sensed by an accelerometer and displayed on the tongue as a pattern of stimulation. This pattern of stimulation moves forward, backward, and laterally on the tongue in direct response to head movements. Users of the device were trained to use this stimulation to adjust their position in order to maintain their balance. Twenty-eight subjects with peripheral or central vestibular loss were trained with the BrainPort balance device and tested using the following standardized quantitative measurements of the treatment effects: Computerized Dynamic Posturography (CDP) using the Sensory Organization Test (SOT), Dynamic Gait Index (DGI), Activities-specific Balance Confidence Scale (ABC), and Dizziness Handicap Inventory (DHI). All subjects had chronic balance problems and all but one had previously participated in vestibular rehabilitation therapy. The scores on the clinical tests upon entry into the study were compared to their scores following training with the BrainPort balance device. Our results exhibit consistent positive and statistically significant improvements in balance, posture and gait. These results exceed what could normally be achieved in three to five days of traditional balance training alone. Since this was not a controlled study, we are unable to distinguish the degree to which these improvements are attributable to training with the BrainPort balance device versus the balance exercises performed by all subjects as a part of the BrainPort training sessions. Nonetheless, after training with the BrainPort balance device, all subjects demonstrated significant improvements in performance beyond what might be expected from conventional vestibular rehabilitation therapy.

Foodborne and waterborne illness among Canadian Indigenous populations: A scoping review.

BACKGROUND: Indigenous populations are often at higher risk for foodborne illness than the general Canadian population. OBJECTIVE: To investigate the extent of the literature on the link between food safety and the occurrence of foodborne and waterborne illness in Canadian Indigenous populations. METHODS: A scoping review was conducted using search strings in five databases and grey literature to identify all papers that studied a Canadian Indigenous population and referred to any potential associations between food safety (including consumption and preparation of traditional foods and retail foods) or water safety practices and food or waterborne illness. Two authors screened papers based on inclusion and exclusion criteria. Included documents were analyzed for emergent themes. RESULTS: From 1,718 unique records identified, 21 documents were selected. Foodborne illness was most common in children up to 14 years old. Walrus, seal, caribou and whale were the most common traditional foods tied to foodborne illness and were primarily associated with botulism and trichinosis. Aside from consuming the food raw, fermentation was the most common traditional preparation method linked to foodborne illness. There was concern about the safety of retail food but no clear link was identified with foodborne illness. Lastly, although there was concern about tap water, the use of alternate water sources, such as untreated brook water, and hygiene and cleaning practices in communities with boil water advisories were the most common risk behaviours associated with waterborne illness. CONCLUSION: Consumption of certain game meats, as well as the use of traditional fermentation practices may lead to an increased risk of foodborne illness among Indigenous populations. Concern about tap water may lead to use of unsafe alternate water sources. Further research is needed to examine potential culturally appropriate food and water safety opportunities.

Effects of estradiol and tamoxifen on creatine kinase in rodent mammary carcinomas.

The effects of altered estrogenic environments on creatine kinase (CK) and adenylate kinase (AK) were studied in two rodent mammary tumor systems, R3230AC and primary 7,12-dimethylbenz(a)anthracene (DMBA)-induced carcinomas, to determine whether response of these enzymes could be related to their hormone dependence. The hormonal perturbations studied were ovariectomy and administration of various doses of estradiol valerate or the antiestrogen tamoxifen. Total CK activity and AK activity were assessed by a spectrophotometric assay followed by electrophoretic separation of the CK isozymes to determine their relative activities. In the ovarian-independent R3230AC tumors, estrogen treatment produced a dose-related decrease in CK activity, whereas CK was not responsive in ovarian-dependent DMBA-induced tumors. Adenylate kinase activity remained unchanged regardless of the hormonal perturbation. Glucose-6-phosphate dehydrogenase and lactate dehydrogenase, which were studied for comparative purposes, were both estrogen responsive. While both estrogenic and antiestrogenic effects on enzyme activities were observed in the DMBA-induced tumors, the effect of tamoxifen in the R3230AC tumors was generally estrogenic. We conclude that the effect of estrogen on CK-BB in DMBA-induced tumors is not sufficient to be used as a biochemical marker of hormone dependence.

Fields of aberrant CpG island hypermethylation in Barrett's esophagus and associated adenocarcinoma.

Esophageal adenocarcinoma (EAC) is thought to develop through a multistage process in which Barrett's metaplasia progresses through low- and high-grade dysplasia to invasive cancer. Transcriptional silencing of tumor suppressor genes by promoter CpG island hypermethylation has been observed in many types of human cancer. Analysis of CpG island hypermethylation in EAC has thus far been limited to the CDKN2A (p16) gene. In this study, we extend the methylation analysis of EAC to include three other genes, APC, CDH1 (E-cadherin), and ESR1 (ER, estrogen receptor alpha), in addition to CDKN2A. Molecular analysis can provide insight into the complex relationships between tissues with different histologies in Barrett's esophagus and associated adenocarcinoma. Therefore, we have mapped the spatial distribution of methylation patterns in six esophagectomy cases in detail. Hypermethylation of the four CpG islands was analyzed by the MethyLight technique in 107 biopsies derived from these six patients for a total of 428 methylation analyses. Our results show that normal esophageal squamous epithelium is unmethylated at all four CpG islands. CDH1 is unmethylated in most other tissue types as well. Hypermethylation of ESR1 is seen at high frequency in inflammatory reflux esophagitis and at all subsequent stages, whereas APC and CDKN2A hypermethylation is found in Barrett's metaplasia, dysplasia, and EAC. When it occurs, hypermethylation of APC, CDKN2A, and ESR1 is usually found in a large contiguous field, suggesting either a concerted methylation change associated with metaplasia or a clonal expansion of cells with abnormal hypermethylation.

Epigenetic patterns in the progression of esophageal adenocarcinoma.

Esophageal adenocarcinoma (EAC) arises after normal squamous mucosa undergoes metaplasia to specialized columnar epithelium (intestinal metaplasia or Barrett's esophagus), which can then ultimately progress to dysplasia and subsequent malignancy. Epigenetic studies of this model have thus far been limited to the DNA methylation analysis of a few genes. In this study, we analyzed a panel of 20 genes using a quantitative, high-throughput methylation assay, METHYLIGHT: We used this broader approach to gain insight into concordant methylation behavior between genes and to generate epigenomic fingerprints for the different histological stages of EAC. Our study included a total of 104 tissue specimens from 51 patients with different stages of Barrett's esophagus and/or associated adenocarcinoma. We screened 84 of these samples with the full panel of 20 genes and found distinct classes of methylation patterns in the different types of tissue. The most informative genes were those with an intermediate frequency of significant hypermethylation [ranging from 15% (CDKN2A) to 60% (MGMT) of the samples]. This group could be further subdivided into three classes, according to the absence (CDKN2A, ESR1, and MYOD1) or presence (CALCA, MGMT, and TIMP3) of methylation in normal esophageal mucosa and stomach, or the infrequent methylation of normal esophageal mucosa accompanied by methylation in all normal stomach samples (APC). The other genes were less informative, because the frequency of hypermethylation was below 5% (ARF, CDH1, CDKN2B, GSTP1, MLH1, PTGS2, and THBS1), completely absent (CTNNB1, RB1, TGFBR2, and TYMS1), or ubiquitous (HIC1 and MTHFR), regardless of tissue type. Each class undergoes unique epigenetic changes at different steps of disease progression of EAC, suggesting a step-wise loss of multiple protective barriers against CpG island hypermethylation. The aberrant hypermethylation occurs at many different loci in the same tissues, suggestive of an overall deregulation of methylation control in EAC tumorigenesis. However, we did not find evidence for a distinct group of tumors with a CpG island methylator phenotype. Finally, we found that normal and metaplastic tissues from patients with evidence of associated dysplasia or cancer had a significantly higher incidence of hypermethylation than similar tissues from patients with no further progression of their disease. The fact that the samples from these two groups of patients were histologically indistinguishable, yet molecularly distinct, suggests that the occurrence of such hypermethylation may provide a clinical tool to identify patients with premalignant Barrett's who are at risk for further progression.

Health-related quality of life in patients served by the Department of Veterans Affairs: results from the Veterans Health Study.

BACKGROUND: The Department of Veterans Affairs Health Care System (VA) is the largest integrated single payer system in the United States. To date, there has been no systematic measurement of health status in the VA. The Veterans Health Study has developed methods to assess patient-based health status in ambulatory populations. OBJECTIVES: To describe the health status of veterans and examine the relationships between their health-related quality of life, age, comorbidity, and socioeconomic and service-connected disability status. METHODS: Participants in the Veterans Health Study, a 2-year longitudinal study, were recruited from a representative sample of patients receiving ambulatory care at 4 VA facilities in the New England region. The Veterans Health Study patients received questionnaires of health status, including the Medical Outcomes Study Short Form 36-Item Health Survey; and a health examination, clinical assessments, and medical history taking. Sixteen hundred sixty-seven patients for whom we conducted baseline assessments are described. RESULTS: The VA outpatients had poor health status scores across all measures of the Medical Outcomes Study Short Form 36-Item Health Survey compared with scores in non-VA populations (at least 50% of 1 SD worse). Striking differences also were found with the sample stratified by age group (20-49 years, 50-64 years, and 65-90 years). For 7 of the 8 scales (role limitations due to physical problems, bodily pain, general health perceptions, vitality, social functioning, role limitations due to emotional problems, and mental health), scores were considerably lower among the younger patients; for the eighth scale (physical function), scores of the young veterans (aged 20-49 years) were almost comparable with the levels in the old veterans (>65 years). The mental health scores of young veterans were substantially worse than all other age groups (P<.001) and scores of screening measures for depression were significantly higher in the youngest age group (51%) compared with the oldest age groups (33% and 16%) (P<.001). CONCLUSIONS: The VA outpatients have substantially worse health status than non-VA populations. Mental health differences between the young and old veterans who use the VA health care system are sharply contrasting; the young veterans are sicker, suggesting substantially higher resource needs. Mental health differences may explain much of the worse health-related quality of life in young veterans. As health care systems continue to undergo a radical transformation, the Department of Veterans Affairs should focus on the provision of mental health services for its younger veteran.

Synthesis, characterization, and water oxidation by a molecular chromophore-catalyst assembly prepared by atomic layer deposition. The "mummy" strategy.

A new strategy for preparing spatially-controlled, multi-component films consisting of molecular light absorbing chromophores and water oxidation catalysts on high surface area, mesoporous metal oxide surfaces is described. Atomic layer deposition (ALD) is used to embed a surface-bound chromophore in a thin layer of inert Al2O3, followed by catalyst binding to the new oxide surface. In a final step, catalyst surface-binding is stabilized by a subsequent ALD overlayer of Al2O3. The ALD assembly procedure bypasses synthetic difficulties arising from the preparation of phosphonic acid derivatized, covalently-linked assemblies. An ALD mummy-based assembly has been used to demonstrate photoelectrochemical dehydrogenation of hydroquinone. Electrocatalytic water oxidation at pH 8.8 is observed over a 2 hour electrolysis period and light-assisted water oxidation over a 6 hour photolysis period with O2 detected with a generator-collector electrode configuration.

The management of ductal carcinoma in situ of the breast.

Ductal carcinoma in situ (DCIS) of the breast is a heterogeneous group of lesions with diverse malignant potential. It is the most rapidly growing subgroup within the breast cancer family with more than 42 000 new cases diagnosed in the United States during 2000. Most new cases are nonpalpable and are discovered mammographically. Treatment is controversial and ranges from excision only, to excision with radiation therapy, to mastectomy. Prospective randomized trials reveal an approximate 50% reduction in local recurrence rate overall with the addition of radiation therapy to excisional surgery, but the published prospective data do not allow the selection of subgroups in whom the benefit from radiation therapy is so small that its risks outweigh its benefits. Nonrandomized single facility series suggest that age, family history, nuclear grade, comedo-type necrosis, tumor size and margin width are all important factors in predicting local recurrence and that one or more of these factors could be used to select subgroups of patients who do not benefit sufficiently from radiation therapy to merit its use. When all patients with ductal carcinoma in situ are considered, the overall mortality from breast cancer is extremely low, only about 1-2%. When conservative treatment fails, approximately 50% of all local recurrences are invasive breast cancer. In spite of this, the mortality rate following invasive local recurrence is relatively low, about 12% with eight years of actuarial follow-up. Genetic changes routinely precede morphological evidence of malignant transformation. Lessons learned from ongoing basic science research will help us to identify those DCIS lesions that are unlikely to progress and to prevent progression in the rest.

Prostanoid concentrations in maternal/fetal plasma and amniotic fluid and intrauterine tissue prostanoid output in relation to myometrial contractility during the onset of adrenocorticotropin-induced preterm labor in sheep.

Prostanoid [prostaglandin (PG)] concentrations were measured in ovine maternal and fetal plasma and amniotic fluid during the onset of preterm labor induced by the administration of a pulsatile infusion of ACTH-(1-24) (P-ACTH; 66.7 ng/min for 15 min every 2 h) to the fetus and in saline-infused controls. P-ACTH administration stimulated a change in intra-uterine pressure from type A-activity, characterized by sustained increases of low amplitude, to type B labor-like activity of short duration, high amplitude (greater than or equal to 10 mm Hg) increases which occurred between 12 and 8 h before the onset of labor. PGF2 alpha and/or PGFM (13,14-dihydro-15-keto PGF2 alpha) concentrations increased consistently in all fluids 16 h or earlier before labor. All PGs increased in fetal carotid arterial plasma (PGE2 greater than PGF2 alpha) and amniotic fluid, and the relative increases in each PG were similar. However, PGF2 alpha and PGFM selectively increased in maternal vena caval and aortic plasma, whereas smaller or negligible increases in the prostacyclin hydrolysis metabolite 6-keto PGF1 alpha (6KF) and PGE2 were noted. The output of PGs E2 and F2 alpha (picograms per 10(5) cells/8 h) increased 1.6- and 1.7-fold, respectively, by cells dispersed from the chorioallantois of P-ACTH-treated animals compared to that in control animals infused with saline for 100 h. From fetal cotyledons, these increases were 2.4-fold (P less than 0.05) and 3.6-fold, respectively. No significant changes occurred in 6-keto PGF1 alpha output from any tissue or PGE2 or PGF2 alpha output from amnion or maternal cotyledons. We conclude 1) that PGs increase in all fluids before the increase in uterine mechanical activity during induced preterm labor, implying that PGs mediate this event and are not a result thereof; 2) that syntheses of PGs E2 and F2 alpha increase similarly in intrauterine tissues with the onset of labor; and 3) that a selective increase in PGF2 alpha, a myometrial stimulatory PG, occurs exclusively in maternal plasma, suggesting that endoperoxide conversion to PGF2 alpha is specifically enhanced during parturition or suggesting the existence of an intrauterine tissue source of 9-keto PG reductase.

Prostaglandin output in relation to parturition by cells dispersed from human intrauterine tissues.

Collagenase-dispersed cells from human amnion, chorion, decidua, and placenta have been maintained in short term cultures to study prostaglandin (PG) biosynthesis in relation to parturition. Cells retained metabolic function during the 6-h incubation period, as determined by the apparently linear utilization of radioactive glucose and the formation of tritiated water. All cells synthesized PGs (E, F, and 6-keto F1 alpha) from endogenous precursors. The output of all three PGs significantly increased in amnion and chorion, but not in decidua or placenta, obtained from women who had entered labor spontaneously at term and delivered vaginally (SL) when compared to women at term, but not in labor, delivered by elective cesarean section (CS). For example, PGE output (picograms per 10(5) cells/6 h) increased from 207 +/- 77 (n = 5) to 908 +/- 334 with labor (mean +/- SEM). The addition of indomethacin (10(-7)-10(-5) M) to SL amnion cells significantly decreased (P less than 0.001, by analysis of variance) PGE and PGF, but not 6-keto PGF1 alpha output. Comparison of PGF output with its metabolite, 13,14-dihydro-15-keto PGF2 alpha (PGFM); indicated that PGF values were similar to or higher than PGFM for all tissues other than CS chorion, where PGFM output was significantly greater (142 +/- 63 vs. 486 +/- 95; n = 5; P less than 0.05). PGFM levels in amnion increased with labor [104 +/- 51 (n = 5) to 341 +/- 96 (n = 5); P less than 0.05], suggesting that PG output increased with labor in the fetal membranes as a result of increased synthesis and not decreased metabolism.

The structure of the fourth abdominal ganglion of the crayfish, Procambarus clarki (Girard). I. Tracts in the ganglionic core.

The organization of the fourth abdominal ganglion of the crayfish, Procambarus clarki, was studied with the light microscope in serial sections stained with osmium ethyl gallate. This ganglion is composed of a ventral rind of somata and a core of alternating layers of through-tracts and commissures. The longitudinal tracts of the ganglion are named according to the system in use for the orthopteran insects, because the basic plans of the crustacean and insect ventral ganglia exhibit striking anatomical parallels. The dorsal tracts are the largest and the most regular in their path through the ganglion. In the ventral posterior quadrant of the ganglion the tracts diverge from the basic plan to pass around the major synaptic neuropil and the bases of the peripheral nerves. This paper reports the three-dimensional anatomy of the major longitudinal through-tracts, internal tracts and commissures, and bases of peripheral nerves. Landmark features of the ganglion--including the tracts, the major artery of the vascular system, the shape of the ganglionic core in section, and prominent single cells, all of which make it possible to recognize specific regions of the ganglion--are described.