The Environmental Health Impact of Hurricane Katrina on New Orleans

Hurricane Katrina caused unprecedented flood damage to New Orleans, Louisiana, and has been the costliest hurricane in US history. We analyzed the environmental and public health outcomes of Hurricane Katrina by using Internet searches to identify epidemiological, sociodemographic, and toxicological measurements provided by regulatory agencies.Atmospheric scientists have now warned that global warming will increase the proportion of stronger hurricanes (categories 4-5) by 25% to 30% compared with weaker hurricanes (categories 1-2).With the new $14.6 billion Hurricane Storm Damage Risk Reduction System providing a 100-year storm surge-defensive wall across the Southeast Louisiana coast, New Orleans will be ready for stronger storms in the future.

Undernutrition in childhood: Clinically based assessment tools and biological markers: Where are we and where should we go?

Despite its association with poor clinical outcomes and increased hospital costs, as of today undernutrition still goes undetected in paediatric hospitals. The reported prevalence of undernutrition in paediatric patients varies considerably. This disparity is partly due to the diversity of methods for its detection and assessment, as well as to the lack of consensus regarding its definition. Several methods, based on varied combinations of morphology characteristics, estimated nutritional intakes and medical conditions have been developed during the last 25 years. However, these tools suffer from poor sensitivity and selectivity particularly in acute conditions. Also while having their own merit, these tools mainly view malnutrition from the energy standpoint, disregarding assessment of specific micronutrients such as minerals and vitamins. In this position paper we make the point that in the era of personalized medicine, present technology offers the possibility of going beyond the traditional nutritional tools for assessing patients' status, and propose the measurement of selected micronutrients and allied metabolic markers in nutritional workup schemes adapted to each clinical condition.

Therapeutic warfarin use and the extrahepatic functions of vitamin K-dependent proteins

The impact of warfarin therapy on the functions of extrahepatic vitamin K-dependent proteins (VKDP) is less clearly understood and less widely recognised in clinical practice than that on the hepatic counterparts (clotting factors II, VII, IX and X). Warfarin inhibits osteocalcin, an abundant extrahepatic VKDP involved in the mineralisation and maturation of bone and thus, primarily by this mechanism, may have an adverse effect on bone health. Whilst some studies do link warfarin use to an increase in osteoporosis and fracture risk others have not. Warfarin also inhibits the extrahepatic VKDP matrix gla protein (MGP) which acts to prevent ectopic calcification of the vasculature. Studies have consistently found a correlation between warfarin use and vascular calcification with inhibition of MGP believed to be the main cause. Inhibition of MGP also appears to explain warfarin's well established teratogenic effect. Further adverse effects may also arise from warfarin's inhibition of other known extrahepatic VKDPs. The available evidence is intriguing, and suggests that the impact of warfarin on the extrahepatic functions of vitamin K-dependent proteins warrants further careful consideration.

Depression, Mental Distress, and Domestic Conflict among Louisiana Women Exposed to the Deepwater Horizon Oil Spill in the WaTCH Study

BACKGROUND

Psychological sequelae are among the most pronounced effects in populations following exposure to oil spills. Women in particular represent a vulnerable yet influential population but have remained relatively understudied with respect to the Deepwater Horizon oil spill (DHOS).

OBJECTIVE

To describe the relationship between oil spill exposure and mental health among women living in the southern coastal Louisiana parishes affected by the DHOS.

METHODS

The Women and Their Children's Health Study administered telephone interviews to a population-based sample of 2,842 women between 2012 and 2014 following the DHOS. Participants were asked about depression, mental distress, domestic conflict, and exposure to the oil spill.

RESULTS

Over 28% of the sample reported symptoms of depression, 13% reported severe mental distress, 16% reported an increase in the number of fights with their partners, and 11% reported an increase in the intensity of partner fights. Both economic and physical exposure were significantly associated with depressive symptoms and domestic conflict, whereas only physical exposure was related to mental distress.

CONCLUSIONS

This large, population-based study of women in southern coastal Louisiana, a particularly disaster-prone area of the country, revealed high rates of poor mental health outcomes. Reported exposure to the DHOS was a significant predictor of these outcomes, suggesting avenues for future disaster mitigation through the provision of mental health services.

CITATION

Rung AL, Gaston S, Oral E, Robinson WT, Fontham E, Harrington DJ, Trapido E, Peters ES. 2016. Depression, mental distress, and domestic conflict among Louisiana women exposed to the Deepwater Horizon Oil Spill in the WaTCH Study. Environ Health Perspect 124:1429-1435; http://dx.doi.org/10.1289/EHP167.

The Deepwater Horizon Oil Spill and Physical Health among Adult Women in Southern Louisiana: The Women and Their Children's Health (WaTCH) Study

BACKGROUND

The Deepwater Horizon Oil Spill (DHOS) is the largest oil spill in U.S. history, negatively impacting Gulf Coast residents and the surrounding ecosystem. To date, no studies have been published concerning physical health outcomes associated with the DHOS in the general community.

OBJECTIVES

We characterized individual DHOS exposure using survey data and examined the association between DHOS exposure and physical health.

METHODS

Baseline data from 2,126 adult women residing in southern Louisiana and enrolled in the Women and Their Children's Health study were analyzed. Exploratory factor analysis was used to characterize DHOS exposure. Odds ratios and 95% confidence intervals for the associations between DHOS exposure and physical health symptoms were estimated using multivariate logistic regression.

RESULTS

A two-factor solution was identified as the best fit for DHOS exposure: physical-environmental exposure and economic exposure. High physical-environmental exposure was significantly associated with all of the physical health symptoms, with the strongest associations for burning in nose, throat, or lungs (OR = 4.73; 95% CI: 3.10, 7.22), sore throat (OR = 4.66; 95% CI: 2.89, 7.51), dizziness (OR = 4.21; 95% CI: 2.69, 6.58), and wheezing (OR = 4.20; 95% CI: 2.86, 6.17). Women who had high-economic exposure were significantly more likely to report wheezing (OR = 1.92; 95% CI: 1.32, 2.79); headaches (OR = 1.81; 95% CI: 1.41, 2.58); watery, burning, itchy eyes (OR = 1.61; 95% CI: 1.20, 2.16); and stuffy, itchy, runny nose (OR = 1.56; 95% CI: 1.16, 2.08).

CONCLUSIONS

Among southern Louisiana women, both physical-environmental and economic exposure to the DHOS were associated with an increase in self-reported physical health outcomes. Additional longitudinal studies of this unique cohort are needed to elucidate the impact of the DHOS on short- and long-term human health.

CITATION

Peres LC, Trapido E, Rung AL, Harrington DJ, Oral E, Fang Z, Fontham E, Peters ES. 2016. The Deepwater Horizon Oil Spill and physical health among adult women in southern Louisiana: the Women and Their Children's Health (WaTCH) study. Environ Health Perspect 124:1208-1213; http://dx.doi.org/10.1289/ehp.1510348.

Safety of long-term restrictive diets for peroxisomal disorders: vitamin and trace element status of patients treated for Adult Refsum Disease

BACKGROUND

Adult Refsum's Disease (ARD) is caused by defects in the pathway for alpha-oxidation of phytanic acid (PA). Treatment involves restricting the dietary intake of phytanic acid by reducing the intake of dairy-derived fat. The adequacy of micronutrient intake in patients with ARD is unknown.

METHODS

Patients established on the Chelsea low-PA diet had general diet macronutrients, vitamins and trace elements assessed using 7-day-weighed intakes and serial 24-h recalls. Intakes were compared with biochemical assessments of nutritional status for haematinics (ferritin), trace elements (copper, zinc, iron, selenium), water- (vitamin B6 , B12 and folate) and fat-soluble vitamins (A, D, E and K).

RESULTS

Eleven subjects (four women, seven men) were studied. Body mass index was 27 ± 5 kg/m(2) (range 19-38). All subjects had high sodium intakes (range 1873-4828 mg). Fat-soluble vitamin insufficiencies occurred in some individuals (vitamin A, n = 2; vitamin D, n = 6; vitamin E, n = 3; vitamin K, n = 10) but were not coincident. Vitamin B6 levels were normal or elevated (n = 6). Folate and 5-methyltetrahydrofolate concentrations were normal. Metabolic vitamin B12 insufficiency was suspected in four subjects based on elevated methylmalonic acid concentrations. Low copper and selenium intakes were noted in some subjects (n = 7, n = 2) but plasma levels were adequate. Iron, ferritin and zinc intakes and concentrations were normal.

CONCLUSION

Subjects with ARD can be safely managed on the Chelsea low PA without routine micronutrient supplementation. Sodium intake should be monitored and reduced. Periodic nutritional screening may be necessary for fat-soluble vitamins, vitamin B12 , copper or selenium.

Circulating concentrations of vitamin E isomers: Association with bone turnover and arterial stiffness in post-menopausal women

The effects of vitamin E on cardiovascular and bone health are conflicting with beneficial and detrimental findings reported. To investigate this further, we carried out a cross-sectional study to determine the relationship between circulating concentrations of the 2 vitamin E isomers, α- and γ-tocopherol (TP) with bone turnover and arterial stiffness. Two hundred and seventy eight post-menopausal women with mean age [SD] 60.9 [6.0] years were studied. Fasting serum α-TP and γ-TP, bone turnover markers; procollagen type 1 amino-terminal propeptide (P1NP) and C-terminal telopeptide of type 1 collagen (CTX), parathyroid hormone (PTH), total cholesterol (TC) and triglycerides (TG) were measured. Pulse wave velocity (PWV) and central augmentation index (AI) as markers of arterial stiffness were also determined. A positive correlation was observed between α-TP and γ-TP (r=0.14, p=0.022). A significant negative association between α-TP and P1NP only was seen in multiple linear regression analysis following adjustment for serum TC and TG (p=0.016). In a full multi-linear regression model, following correction for age, years since menopause, smoking habits, alcohol intake, use of calcium supplements, BMI, PTH, serum calcium, and estimated glomerular filtration rate (eGFR), the association between α-TP and P1NP remained significant (p=0.011). We did not observe any significant association between γ-TP or α-TP/γ-TP ratio with P1NP or CTX. P1NP was significantly lower in subjects with α-TP concentrations of >30 μmol/L (α-TP >30 μmol/L; P1NP: 57.5 [20.7], α-TP<30 μmol/L; P1NP: 65.7 [24.9] μg/L, p=0.005). PWV was significantly associated with α-TP/γ-TP ratio (p=0.04) but not with serum α-TP or γ-TP in a full multi-linear regression model adjusting for serum lipids, age, and blood pressure. The data suggest that high serum concentrations of α-TP may have a negative effect on bone formation. The balance of α-TP and γ-TP may be important in maintaining arterial compliance. Longitudinal studies are needed to investigate the impact of the vitamin E isomers on bone and cardiovascular health.

Vitamin K and other markers of micronutrient status in morbidly obese patients before bariatric surgery

BACKGROUND

Micronutrient deficiencies occur in morbidly obese patients. The aim of this study was to assess vitamin deficiencies prior to bariatric surgery including vitamin K about which there is little data in this population.

METHODS

A prospective assessment of 118 consecutive patients was performed. Clinical allied with haematological and biochemical variables were measured. Micronutrients measured included vitamins K1 , PIVKA-II (protein-induced in vitamin K absence factor II), vitamin D, vitamin B12 (holotranscobalamin), iron, transferrin and folate.

RESULTS

Patients were aged 49 ± 11 [mean (SD, standard deviation)] years, body mass index (BMI) 50 ± 8 kg/m(2), 66% female and 78% Caucasian. Hypertension was present in 47% and type 2 diabetes in 32%. Vitamin D supplements had been prescribed in 8%. Micronutrient insufficiencies were found for vitamin K (40%), vitamin D (92%) and vitamin B12 (25%), and also iron (44%) and folate (18%). Normocalcaemic vitamin D insufficiency with secondary hyperparathyroidism was present in 18%. Iron and transferrin levels were associated with age, sex and estimated glomerular filtration rate. Vitamin K levels were associated with age, and inversely with BMI and diabetes mellitus; and PIVKA-II with smoking, triglycerides and liver function markers. Vitamin D levels were associated with statin use and prescription of supplements and inversely with BMI. Vitamin B12 levels were associated with ethnicity and HbA1c.

CONCLUSION

Micronutrient status shows differing relationships with age, gender and BMI. Vitamin K insufficiency was present in 40% and not related to deficiencies in other vitamins or micronutrients. Vitamin D and vitamin K supplementation should be considered prebariatric surgery in patients with diabetes or severe insulin resistance.

Association of bone turnover markers and arterial stiffness in pre-dialysis chronic kidney disease (CKD)

Vascular calcification (VC) is highly prevalent in CKD and leads to increased vascular stiffness and cardiovascular disease (CVD). Non-traditional cardiovascular risk factors include abnormal bone turnover and/or dysregulation of the calcification inhibitors, although their relative contribution remains unclear. We investigated the association between bone turnover, the calcification inhibitors (matrix gla protein; MGP and Fetuin-A), and the phosphate regulating hormone; fibroblast growth factor-23 (FGF-23) and arterial stiffness in pre-dialysis CKD patients. One hundred and forty-five patients with CKD stages 1-4 (74 M, 71 F) aged (mean [SD]) 53 [14] years were studied. Bone turnover markers (bone-specific alkaline phosphatase (BALP) and tartrate-resistant acid phosphatase (TRACP)) and MGP, Fetuin-A and FGF-23 were determined. BMD was measured at the lumbar spine (LS), femoral neck (FN), forearm (FARM) and total hip (TH). Arterial stiffness was assessed by contour analysis of digital volume pulse (SI(DVP)). There was a significant positive correlation between TRACP:BALP ratio and SI(DVP) ( r=0.19, p=0.023). Following multi-linear regression analysis, significant associations were seen between serum BALP (p=0.037), TRACP (p=0.009) and TRACP:BALP ratio (p=0.001) and SI(DVP) independently of traditional CVD risk factors. No significant relationship between SI(DVP) and MGP, Fetuin-A and FGF-23 was observed. A significant negative correlation was seen between BMD at the FARM and SI(DVP) in CKD stage 4 (r=-0.35, p=0.024). The association remained significant following correction for age, gender and cardiovascular risk factors (p=0.029). Our data suggest a link between imbalances in bone turnover and arterial stiffness in pre-dialysis CKD. Longitudinal studies are needed to evaluate the clinical usefulness of these bone turnover markers as predictors of CVD in CKD.

TM0486 from the hyperthermophilic anaerobe Thermotoga maritima is a thiamin-binding protein involved in response of the cell to oxidative conditions

The COG database was used for a comparative genome analysis with genomes from anaerobic and aerobic microorganisms with the aim of identifying proteins specific to the anaerobic way of life. A total of 33 COGs were identified, five of which correspond to proteins of unknown function. We focused our study on TM0486 from Thermotoga maritima, which belongs to one of these COGs of unknown function, namely COG0011. The crystal structure of the protein was determined at 2 A resolution. The structure adopts a beta alpha beta beta alpha beta ferredoxin-like fold and assembles as a homotetramer. The structure also revealed the presence of a pocket in each monomer that bound an unidentified ligand. NMR and calorimetry revealed that TM0486 specifically bound thiamin with a K(d) of 1.58 microM, but not hydroxymethyl pyrimidine (HMP), which has been implicated as a potential ligand. We demonstrated that the TM0486 gene belongs to the same multicistronic unit as TM0483, TM0484 and TM0485. Although these three genes have been assigned to the transport of HMP, with TM0484 being the periplasmic thiamin/HMP-binding protein and TM0485 and TM0483 the transmembrane and the ATPase components, respectively, our results led us to conclude that this operon encodes an ABC transporter dedicated to thiamin, with TM0486 transporting charged thiamin in the cytoplasm. Given that this transcriptional unit was up-regulated when T. maritima was exposed to oxidative conditions, we propose that, by chelating cytoplasmic thiamin, TM0486 and, by extension, proteins belonging to COG0011 are involved in the response mechanism to stress that could arise during aerobic conditions.

Pharmacodynamic resistance to warfarin is associated with nucleotide substitutions in VKORC1

BACKGROUND

Vitamin K epoxide reductase subunit 1 (VKORC1) is the molecular target of coumarin anticoagulants and mutations in VKORC1 have been identified previously in individuals who required high warfarin doses.

OBJECTIVE

Detailed characterization of the relationship between variation in VKORC1 and the warfarin resistance phenotype.

PATIENTS AND METHODS

Serum warfarin concentration and coagulation parameters were determined in 289 subjects who required warfarin doses >20 mg day(-1). The VKORC1 sequence was studied in selected study subjects.

RESULTS

Twenty-eight out of 289 (10%) subjects had serum warfarin >2.3 mg L(-1) during stable therapeutic anticoagulation indicating pharmacodynamic warfarin resistance. Detailed analysis of 15 subjects from this group showed that eight out of 15 (53%) had nucleotide substitutions in VKORC1 predictive of p.V66M, p.L128R, p.V54L or p.D36Y. VKORC1 was normal in the remaining seven out of 15 (47%) subjects and in nine out of nine (100%) subjects with high warfarin dose requirement not caused by pharmacodynamic resistance. At referral, subjects with VKORC1 mutations received a median warfarin dose of 32 mg day(-1) (range 22-55) and had a median serum warfarin concentration of 4.6 mg L(-1) (range 2.6-9.0). VKORC1 substitutions were associated with a requirement for high warfarin doses but not with adverse clinical events. Family members with VKORC1 nucleotide substitutions and not receiving warfarin had undetectable PIVKA-II and K(1) epoxide (K(1)O).

CONCLUSIONS

Nucleotide variations in VKORC1 are a common cause of pharmacodynamic warfarin resistance but are not associated with adverse outcome during anticoagulation. Mutations associated with warfarin resistance do not cause a discernible defect in VKORC1 reductase function.

A study of the prevalence of vitamin K deficiency in patients with cancer referred to a hospital palliative care team and its association with abnormal haemostasis

Background:

Many patients with advanced cancer are malnourished. Anorexia is common, as is the use of chemotherapy, which may cause nausea and poor appetite. Ten per cent of these patients experience haemorrhagic events.

Aim:

Since vitamin K deficiency (VKD) causes bleeding, to establish the prevalence of VKD in patients with advanced cancer receiving palliative care.

Methods:

Serum concentrations of vitamin K1 and undercarboxylated factor II (PIVKA-II) were determined in 46 (17 male/29 female) inpatients aged 26–85 (mean 58) years. INR and liver function tests (bilirubin, ALT, GGT and ALP) were also performed.

Results:

Vitamin K1 was below the lower limit of the reference range (0.33 nmol/l) in 22% of patients. 78% of patients had some degree of functional VKD indicated by raised (>0.2 AU/ml) PIVKA-II. Six patients (13%) had a prolonged INR, all of whom had raised PIVKA-II and GGT; 4 also had vitamin K1 <0.33 nmol/l. Three patients (6.5%) had clinically significant VKD characterised by INR >1.5, PIVKA-II >10 AU/ml, and undetectable vitamin K1.

Conclusions:

Patients with advanced cancer are prone to VKD which, while usually subclinical, may develop to a clinically relevant prolongation of the INR. Serum measurements of vitamin K1 and PIVKA-II can be used to detect VKD and monitor vitamin K status before an increased risk of bleeding develops.

Does a first trimester dating scan using crown rump length measurement reduce the rate of induction of labour for prolonged pregnancy? An uncompleted randomised controlled trial of 463 women

OBJECTIVE

To evaluate the effect of a first trimester ultrasound dating scan on the rate of induction of labour for prolonged pregnancy.

DESIGN

Randomised controlled trial to include 400 women in each arm of the trial.

SETTING

Participating general practices and a district general teaching hospital.

POPULATION

Women attending their general practitioner in the first trimester to confirm pregnancy, in whom a first trimester ultrasound scan was not indicated.

METHODS

Women randomised to the study group (scan group) underwent an ultrasound dating scan between 8 and 12 weeks, measuring crown-rump length. The estimated date of delivery (EDD) was changed if there was a discrepancy of more than 5 days from the gestation, calculated from the last menstrual period (LMP). For the remaining women (no-scan group), gestation was determined using the LMP.

MAIN OUTCOME MEASURES

The rate of induction of labour for prolonged pregnancy.

RESULTS

Due to circumstances beyond the researchers' control, recruitment was abandoned when 463 women had been enrolled. The EDD was adjusted in 13 (5.7%) women in the scan group and in 2 (0.9%) in the no-scan group. There was no difference in the rate of induction for prolonged pregnancy between the scan (19 [8.2%]) and the no-scan (17 [7.4%]) groups (relative risk 1.10; 95% CI 0.59-2.07).

CONCLUSIONS

Acknowledging the reduced numbers recruited for study, it is concluded that there is no evidence that a first trimester ultrasound dating scan reduces the rate of induction of labour for prolonged pregnancy and may result in a more expensive healthcare strategy.

Crystal structure of a bacterial ribonuclease P RNA

The x-ray crystal structure of a 417-nt ribonuclease P RNA from Bacillus stearothermophilus was solved to 3.3-A resolution. This RNA enzyme is constructed from a number of coaxially stacked helical domains joined together by local and long-range interactions. These helical domains are arranged to form a remarkably flat surface, which is implicated by a wealth of biochemical data in the binding and cleavage of the precursors of transfer RNA substrate. Previous photoaffinity crosslinking data are used to position the substrate on the crystal structure and to identify the chemically active site of the ribozyme. This site is located in a highly conserved core structure formed by intricately interlaced long-range interactions between interhelical sequences.

Ethnic differences in osteocalcin gamma-carboxylation, plasma phylloquinone (vitamin K1) and apolipoprotein E genotype

OBJECTIVE

To investigate plasma osteocalcin gamma-carboxylation and its relationship to plasma phylloquinone concentration and apolipoprotein E (apoE) genotype in women from three ethnic groups with differing osteoporotic fracture risk.

DESIGN AND SUBJECTS

Fasted blood samples were collected from postmenopausal Gambian (n=50), British (n=31) and Chinese women (n=23), and 11 premenopausal women in each group from three cross-sectional studies.

RESULTS

After adjustment for total osteocalcin, plasma undercarboxylated osteocalcin (adjusted ucOC) was lowest in Chinese and highest in British women postmenopause (British vs Chinese 103% higher, P<0.0001; Gambian vs Chinese 66% higher, P<0.01). No differences were observed premenopause. Within each ethnic group, adjusted ucOC was similar pre- and postmenopause. Postmenopause, plasma phylloquinone was higher in Chinese women (1.0 ng/ml) than in British (0.31 ng/ml) and Gambian women (0.36 ng/ml) (P<0.0001). Premenopause, plasma phylloquinone was higher in Gambian and Chinese women (0.6 ng/ml) than in British women (0.3 ng/ml; P=0.01). Plasma phylloquinone and adjusted ucOC were inversely related in postmenopausal British women (R2=32.4%; P=0.0008). ApoE4 frequency was Gambian 32.6%, British 13.8% and Chinese 6%. A lower adjusted ucOC was associated with apoE2 genotype in British and Chinese women. Ethnic differences in adjusted ucOC persisted after adjustment for phylloquinone and apoE genotype.

CONCLUSION

These preliminary data indicate suboptimal vitamin K status in postmenopausal British compared to Chinese and Gambian women. Ethnic differences in apoE genotype may also influence osteocalcin gamma-carboxylation status. The study highlights the need for larger epidemiological investigations of ethnic differences in vitamin K status and the possible implications to bone health.

High-resolution structure of RNase P protein from Thermotoga maritima

The structure of RNase P protein from the hyperthermophilic bacterium Thermotoga maritima was determined at 1.2-A resolution by using x-ray crystallography. This protein structure is from an ancestral-type RNase P and bears remarkable similarity to the recently determined structures of RNase P proteins from bacteria that have the distinct, Bacillus type of RNase P. These two types of protein span the extent of bacterial RNase P diversity, so the results generalize the structure of the bacterial RNase P protein. The broad phylogenetic conservation of structure and distribution of potential RNA-binding elements in the RNase P proteins indicate that all of these homologous proteins bind to their cognate RNAs primarily by interaction with the phylogenetically conserved core of the RNA. The protein is found to dimerize through an extensive, well-ordered interface. This dimerization may reflect a mechanism of thermal stability of the protein before assembly with the RNA moiety of the holoenzyme.

Expression, purification, crystallization and preliminary diffraction analysis of RNase P protein from Thermotoga maritima

Ribonuclease P (RNase P), the ubiquitous endonuclease that catalyzes maturation of the 5'-end of tRNA in bacteria, is a ribonucleoprotein particle composed of one large RNA and one small protein. Two major structural types of bacterial RNase P RNA have been identified by phylogenetic comparative analysis: the A (ancestral) and B (Bacillus) types. The RNase P protein from Thermotoga maritima, a hyperthermophilic bacterium with an A-type RNase P RNA, has been expressed in Escherichia coli. A purification strategy was developed to obtain a protein preparation suitable for crystallization. Protein crystals suitable for diffraction studies were obtained and characterized.

Plasma phylloquinone (vitamin K1) concentration and its relationship to intake in a national sample of British elderly people

Plasma phylloquinone (vitamin K1) concentration was examined according to season, socio-demographic and lifestyle factors and phylloquinone intake in a nationally representative sample of British people aged 65 years and over from the 1994-5 National Diet and Nutrition Survey. Values for both plasma phylloquinone concentration and phylloquinone intake were available from 1076 participants (561 men, 515 women). Eight hundred and thirty-four were living in private households, 242 in residential or nursing homes. Weighted geometric mean plasma phylloquinone concentrations were 0.36 (inner 95% range [corrected] 0.06, 2.01) and 0.24 (inner 94% range [corrected] 0.06, 0.96) nmol/l in free-living and institution samples respectively. Plasma phylloquinone concentrations did not generally differ between men and women, although values in free-living people were significantly lower during autumn and winter (October to March). Plasma phylloquinone concentration was not significantly associated with age. Plasma phylloquinone concentrations were positively correlated with phylloquinone intake in free-living men and women (r 0.18 and 0.30 respectively, both P<0.001). Stepwise multiple regression analysis found that 11 % of the variation in plasma phylloquinone concentration was explained by phylloquinone intake, season and plasma triacylglycerol concentration. After adjustment for age and corresponding nutrient intakes, plasma phylloquinone concentration was significantly associated (each P<0.01) with plasma concentrations of triacylglycerol, cholesterol, retinol and 25-hydroxyvitamin D in free-living women but not men, and with plasma concentrations of carotenes, alpha- and gamma-tocopherols and lutein in free-living men and women. The possibility of concurrent low fat-soluble vitamin status in elderly populations may be a cause for concern.

Structural basis of the enhanced stability of a mutant ribozyme domain and a detailed view of RNA--solvent interactions

BACKGROUND

The structure of P4-P6, a 160 nucleotide domain of the self-splicing Tetrahymena thermophila intron, was solved previously. Mutants of the P4-P6 RNA that form a more stable tertiary structure in solution were recently isolated by successive rounds of in vitro selection and amplification.

RESULTS

We show that a single-site mutant (Delta C209) possessing greater tertiary stability than wild-type P4-P6 also crystallizes much more rapidly and under a wider variety of conditions. The crystal structure provides a satisfying explanation for the increased stability of the mutant; the deletion of C209 allows the adjacent bulged adenine to enter the P4 helix and form an A-G base pair, presumably attenuating the conformational flexibility of the helix. The structure of another mutant (Delta A210) was also solved and supports this interpretation. The crystals of Delta C209 diffract to a higher resolution limit than those of wild-type RNA (2.25 A versus 2.8 A), allowing assignment of innersphere and outersphere coordination contacts for 27 magnesium ions. Structural analysis reveals an intricate solvent scaffold with a preponderance of ordered water molecules on the inside rather than the surface of the folded RNA domain.

CONCLUSIONS

In vitro evolution facilitated the identification of a highly stable, structurally homogeneous mutant RNA that was readily crystallizable. Analysis of the structure suggests that improving RNA secondary structure can stabilize tertiary structure and perhaps promote crystallization. In addition, the higher resolution model provides new details of metal ion-RNA interactions and identifies a core of ordered water molecules that may be integral to RNA tertiary structure formation.

Human herpesvirus 6 and multiple sclerosis: systemic active infections in patients with early disease

By means of immunohistochemical staining, cells actively infected with human herpesvirus 6 (HHV-6) were found in central nervous system tissues from 8 (73%) of 11 patients with definite multiple sclerosis (MS). Interestingly, 17 (90%) of 19 tissue sections showing active demyelination were positive for HHV-6-infected cells compared with only 3 (13%) of 23 tissue sections free of active disease (P<.0001). Central nervous system tissues from 2 of 28 normal persons and patients with other inflammatory demyelinative diseases were positive for HHV-6-infected cells (P<.0001), and the 2 positive cases were diagnosed as having HHV-6 leukoencephalitis. By use of a rapid culture assay, blood samples from 22 (54%) of 41 patients with definite MS were found to contain active HHV-6 infections, compared with 0 of 61 normal controls (P<.0001). No significant difference was found between HHV-6 viremia-positive and HHV-6 viremia-negative MS patients with respect to type of disease (relapsing/remitting or progressive). In contrast, patients with active HHV-6 viremia were significantly younger and had shorter durations of disease than did HHV-6 viremia-negative patients.

Identification of lipoprotein homologues of pneumococcal PsaA in the equine pathogens Streptococcus equi and Streptococcus zooepidemicus

Streptococcus equi and Streptococcus zooepidemicus are major etiological agents of upper and lower airway disease in horses. Despite the considerable animal suffering and economic burden associated with these diseases, the factors that contribute to the virulence of these equine pathogens have not been extensively investigated. Here we demonstrate the presence of a homologue of the Streptococcus pneumoniae PsaA protein in both of these equine pathogens. Inhibition of signal peptide processing by the antibiotic globomycin confirmed the lipoprotein nature of the mature proteins, and surface exposure was confirmed by their release from intact cells by mild trypsinolysis.

Compilation of a provisional UK database for the phylloquinone (vitamin K1) content of foods

This paper reports the compilation of a food composition database for phylloquinone (vitamin K1) derived from the direct analysis of foods, recipe calculation and the assignment of values based on food similarities. All the basic and other food items used in these calculations had been analysed by HPLC and about 170 of the items had been obtained and assayed in the UK. Recipe calculations took account of the cooking method and changes in water and fat content. Currently, approximately 1501 food items with Royal Society of Chemistry/Ministry of Agriculture, Fisheries and Food food codes have been allocated a vitamin K1 value, and a further 282 new recipe codes are included in the database. Representative values from each food group are reported together with an indication of the potential variation. Detailed examples of some recipe calculations are included, and also the impact of changing the type of fat in recipes. Vitamin K1 is associated with, and most abundant in, photosynthetic tissues of plants. Accordingly, the highest concentrations (3000-6000 micrograms/kg) are found in dark-green leafy vegetables and herbs, such as kale, parsley, spinach and green cabbage. Intermediate concentrations (1000-2000 micrograms/kg) are found in plants with paler leaves such as white cabbage and lettuce or in green, non-leafy vegetables such as broccoli and brussel sprouts. Fats and oils contain variable amounts of vitamin K1 with the highest concentrations (300-1300 micrograms/kg) in soyabean, rapeseed and olive oils and the margarines based on them. Other foods such as dairy products, meat dishes and cereal-based foods (bread, biscuits, cakes, desserts etc.), although not in themselves particularly rich in vitamin K1 (< 200 micrograms/kg), may contribute significantly to intakes when consumption of green vegetables is poor. Within the scope of this present study, it has not been possible to address issues such as inter-sample variability, losses during storage or the bioavailability from different foods and further work on these aspects is needed.

X-Ray crystal structure and molecular dynamics simulations of silver hake parvalbumin (Isoform B)

Parvalbumins constitute a class of calcium-binding proteins characterized by the presence of several helix-loop-helix (EF-hand) motifs. In a previous study (Revett SP, King G, Shabanowitz J, Hunt DF, Hartman KL, Laue TM, Nelson DJ, 1997, Protein Sci 7:2397-2408), we presented the sequence of the major parvalbumin isoform from the silver hake (Merluccius bilinearis) and presented spectroscopic and structural information on the excised "EF-hand" portion of the protein. In this study, the X-ray crystal structure of the silver hake major parvalbumin has been determined to high resolution, in the frozen state, using the molecular replacement method with the carp parvalbumin structure as a starting model. The crystals are orthorhombic, space group C2221, with a = 75.7 A, b = 80.7 A, and c = 42.1 A. Data were collected from a single crystal grown in 15% glycerol, which served as a cryoprotectant for flash freezing at -188 degrees C. The structure refined to a conventional R-value of 21% (free R 25%) for observed reflections in the range 8 to 1.65 A [1 > 2sigma(I)]. The refined model includes an acetylated amino terminus, 108 residues (characteristic of a beta parvalbumin lineage), 2 calcium ions, and 114 water molecules per protein molecule. The resulting structure was used in molecular dynamics (MD) simulations focused primarily on the dynamics of the ligands coordinating the Ca2+ ions in the CD and EF sites. MD simulations were performed on both the fully Ca2+ loaded protein and on a Ca2+ deficient variant, with Ca2+ only in the CD site. There was substantial agreement between the MD and X-ray results in addressing the issue of mobility of key residues in the calcium-binding sites, especially with regard to the side chain of Ser55 in the CD site and Asp92 in the EF site.

Crystal structure of epidoxorubicin-formaldehyde virtual crosslink of DNA and evidence for its formation in human breast-cancer cells

Epidoxorubicin and daunorubicin are proposed to be cytotoxic to tumor cells by catalyzing production of formaldehyde through redox cycling and using the formaldehyde for covalent attachment to DNA at G bases. The crystal structure of epidoxorubicin covalently bound to a d(CGCGCG) oligomer was determined to 1.6 A resolution. The structure reveals slightly distorted B-form DNA bearing two molecules of epidoxorubicin symmetrically intercalated at the termini, with each covalently attached from its N3' to N2 of a G base via a CH2 group from the formaldehyde. The structure is analogous to daunorubicin covalently bound to d(CGCGCG) determined previously, except for additional hydrogen bonding from the epimeric O4' to O2 of a C base. The role of drug-DNA covalent bonding in cells was investigated with synthetic epidoxorubicin-formaldehyde conjugate (Epidoxoform) and synthetic daunorubicin-formaldehyde conjugate (Daunoform). Uptake and location of drug fluorophore in doxorubicin-resistant human breast-cancer cells (MCF-7/ADR cells) was observed by fluorescence microscopy and flow cytometry. The fluorophore of Daunoform appeared more rapidly in cells and was released more rapidly from cells than the fluorophore of Epidoxoform over a 3 h exposure period. The fluorophore appeared predominantly in the nucleus of cells treated with both conjugates. The difference in uptake is explained in terms of the slower rate of hydrolysis of Epidoxoform to the species reactive with DNA and a proposed slower release from DNA based upon the crystal structures.

Tenascin is differentially expressed in endometrium and endometriosis

Endometriosis is characterized by the presence of functional endometrial tissue outside the uterine cavity, most commonly on the ovary and peritoneum. The aetiology of endometriosis is not understood, although the adhesion of endometrial cells to the extracellular matrix (ECM) would be expected to play a central role in its pathogenesis. The expression of ECM molecules in endometrium and in endometriosis has been investigated using immunohistochemistry and western blotting techniques. The ECM components collagen IV, laminin, vitronectin, and fibronectin had a similar pattern of expression throughout the menstrual cycle in endometrium and endometriosis. Expression of tenascin was elevated in the stroma of the functionalis region of the endometrium during the proliferative stage of the menstrual cycle and in endometriosis. Tenascin expression in endometriosis was not modulated according to the stage of the menstrual cycle. It is concluded that expression of tenascin is strictly regulated in endometrium and may be important in endometrial regeneration and in the pathogenesis of endometriosis.

Crystal structure of deoxy-human hemoglobin beta6 Glu --> Trp. Implications for the structure and formation of the sickle cell fiber

An atomic-level understanding of the interactions between hemoglobin molecules that contribute to the formation of pathological fibers in sickle cell disease remains elusive. By exploring crystal structures of mutant hemoglobins with altered polymerization properties, insight can be gained into sickle cell hemoglobin (HbS) polymerization. We present here the 2.0-A resolution deoxy crystal structure of human hemoglobin mutated to tryptophan at the beta6 position, the site of the glutamate --> valine mutation in HbS. Unlike leucine and isoleucine, which promote polymerization relative to HbS, tryptophan inhibits polymerization. Our results provide explanations for the altered polymerization properties and reveal a fundamentally different double strand that may provide a model for interactions within a fiber and/or interactions leading to heterogeneous nucleation.

The high resolution crystal structure of deoxyhemoglobin S

We have refined the crystal structure of deoxyhemoglobin S (beta Glu6-->Val) at 2.05 A resolution to an R-factor of 16.5% (free R=21. 5%) using crystals isomorphous to those originally grown by Wishner and Love. A predominant feature of this crystal form is a double strand of hemoglobin tetramers that has been shown by a variety of techniques to be the fundamental building block of the intracellular sickle cell fiber. The double strand is stabilized by lateral contacts involving the mutant valine interacting with a pocket between the E and F helices on another tetramer. The new structure reveals some marked differences from the previously refined 3.0 A resolution structure, including several residues in the lateral contact which have shifted by as much as 3.5 A. The lateral contact includes, in addition to the hydrophobic interactions involving the mutant valine, hydrophilic interactions and bridging water molecules at the periphery of the contact. This structure provides further insights into hemoglobin polymerization and may be useful for the structure-based design of therapeutic agents to treat sickle cell disease.

Covert poisoning with difenacoum: clinical and toxicological observations

1. The coumarin anticoagulant difenacoum was detected by high performance liquid chromatography (HPLC) with multi-wavelength UV detection in plasma from a 41 years old man who presented with a severe deficiency of vitamin K-dependent clotting factors of unknown aetiology. A longitudinal toxicological study of the consequent coagulopathy is described. 2. Plasma concentrations of difenacoum declined from 0.97 to 0.11 mgl-1 in 47 days with a terminal half life of 11.7 days. Rifampacin (300 mg bd) had no apparent effect on the terminal half life of the drug. Subsequently plasma concentrations of difenacoum and descarboxyprothrombin (DCP) unexpectedly increased. 3. Seven months after exposure clotting times were prolonged. The patient continued to have episodes of epistaxis, haematoma, purpurae and bruising and he required frequent treatment with Fresh Frozen Plasma in additional to oral phylloquinone (200 mg day-1). 4. Intermittent and unexpected increases in plasma concentrations of difenacoum and descarboxypro-thrombin suggested that covert, repeated ingestion of the anticoagulant was the most likely cause of the poisoning. The measurement of low concentrations of plasma phylloquinone except following supervised ingestion of the vitamin indicated that as an outpatient, the subject was not compliant with treatment despite his protestations to the contrary. He continued to deny this even when confronted by laboratory findings and at no time did he ever admit to self-poisoning.

Polycystic ovary syndrome: aetiology and management

Polycystic ovary syndrome (PCOS) is a heterogeneous condition with a range of clinical, endocrine and metabolic manifestations. Because the aetiology of PCOS is still unclear, it is necessary to develop a management orientated approach to the condition, depending upon the individual patient's needs.

The 2.0 A crystal structure of Scapharca tetrameric hemoglobin: cooperative dimers within an allosteric tetramer

The crystal structure of the allosteric tetrameric hemoglobin from Scapharca inaequivalvis (HbII) has been determined in the carbonmonoxy liganded state using a combination of anomalous scattering and molecular replacement. The molecular model has been refined at 2.0 A resolution to a conventional R-factor of 0.173 and a free R-factor of 0.244. The tetramer is formed from two identical heterodimers. Each heterodimer is assembled with intersubunit contacts involving the E and F helices and heme groups in a manner that is very similar to that of the cooperative Scapharca homodimeric hemoglobin. In addition, the ordered water structure observed in these dimeric interfaces is quite similar. These structural similarities strongly suggest that the dimers within the Scapharca tetramer are cooperative. Subunits assemble into a tetramer in a distinctly non-tetrahedral arrangement, with the pseudo 2-fold axes of the heterodimer oriented at an angle of 74.5 degrees relative to the molecular 2-fold. This arrangement requires that two subunit types have distinct locations and contacts, despite the very similar tertiary structures. HbII polymerizes to higher-order assemblages in a ligand, proton and anion dependent fashion. The lattice contacts in the HbII-CO crystal suggest possible modes for this association.

Progressive immunodeficiency and fatal pneumonitis associated with human herpesvirus 6 infection in an infant

Human herpesvirus 6 (HHV-6), an important opportunistic pathogen in immunocompromised patients, causes fatal pneumonitis, encephalitis, and bone marrow suppression. Its ability to infect and destroy T lymphocytes may allow it to synergize with the human immunodeficiency virus in the destruction of lymphoid tissues in patients with AIDS. We describe herein an infant who had an immunodeficiency associated with thymic atrophy and severe T lymphocytopenia who developed fatal pneumonitis due to HHV-6. Dense and disseminated infection of T lymphocytes with HHV-6 was also documented. In the absence of any other documented cause of immunodeficiency, we hypothesize that congenital infection of this infant with HHV-6 may have caused progressive destruction of her cellular immune system, leading to the fatal pneumonitis. Thus, HHV-6 infection may have been the cause of both her immunodeficiency and her fatal opportunistic infection.

Identity of Streptococcus mutans surface protein antigen III and wall-associated protein antigen A

Preparations of Streptococcus mutans surface proteins AgIII and antigen A from different laboratories were compared with regard to amino acid composition, N-terminal amino acid sequence, electrophoretic mobility, and antigenic similarity. Despite previous observations of differences in physical properties, data indicate that these two preparations represent the same protein.

Identification and genetic characterisation of melibiose-negative isolates of Streptococcus mutans

Streptococcus mutans is frequently identified on the basis of phenotypic characteristics such as the ability to ferment carbohydrates. The usefulness of some of these identification tests may be limited in the case of isolates which are atypical with regard to their fermentation properties. We previously identified isolates of S. mutans which were unable to ferment melibiose, a characteristic which is included in some typing schemes. In all of these isolates there was a large chromosomal deletion which included the multiple sugar metabolism (msm) operon which encodes several genes involved in the uptake and metabolism of a number of sugars including melibiose. In the present study, sugar fermentation tests, ribotyping, colony hybridisation with DNA probes and polymerase chain reaction (PCR) were used to investigate the relatedness of these atypical isolates. The PCR and colony hybridisation procedures were based on amplification and detection of two genes: the wapA gene which encodes a surface protein found in all S. mutans strains and the gtfA gene which lies within the msm operon. The colony hybridisation and PCR results confirmed loss of the gtfA gene in the melibiose-negative isolates. Three new melibiose-negative isolates were also identified, but in only 2 of these was the gtfA gene absent, the third did not appear to have lost this region of the chromosome. Biotyping, as well as ribotyping based on an EcoRI digest of chromosomal DNA, revealed that the melibiose-negative isolates fell into a number of distinct groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Identification and characterisation of two extracellular proteases of Streptococcus mutans

Streptococcus mutans was shown to produce two extracellular proteases capable of degrading both gelatin and collagen-like substrates. These enzymes have molecular masses of 52 and 50 kDa when analysed by SDS-PAGE. Both enzymes were inhibited by EDTA, but not by a range of other inhibitors with different specificities, indicating that they are metalloproteases. The activity of EDTA-inactivated enzymes could be restored by the addition of manganese and zinc. The identical inhibition and restoration profiles of the two enzymes suggest that one of the proteases may be a degradation product of the other.

Multiple changes in cell wall antigens of isogenic mutants of Streptococcus mutans

Isogenic mutants of Streptococcus mutans LT11, deficient in the production of the wall-associated protein antigens A and B, were generated by recombinant DNA technology. The hydrophobicity, adherence, and aggregation of the mutants were compared with those of the parent strain. These studies indicated that hydrophobicity, adherence, and saliva- or sucrose-induced aggregation were unaltered in the A- mutant but that hydrophobicity and adherence to saliva-coated hydroxylapatite were greatly reduced in the B- mutant whilst sucrose-dependent adherence and aggregation were increased. To determine whether these changes correlated with changes in the mutated gene product alone, the levels of a number of cell wall antigens were determined in each of the mutants. The loss of antigen A resulted in significantly reduced levels of wall-associated lipoteichoic acid, and loss of antigen B resulted in reductions in both antigen A and lipoteichoic acid. Data presented here thus suggest that changes in the expression of one wall antigen can have a dramatic effect on the levels of others.

Effect of maternal hyperketonemia in hyperglycemic pregnant ewes and their fetuses

The fetus of the pregnant diabetic woman is exposed to hyperglycemia frequently accompanied by ketoacidosis. Previous studies have demonstrated that beta-hydroxybutyrate, a major ketone body, crosses the ovine placenta in significant amounts, leading to significant reductions in fetal PaO2 and increased fetal heart rate. In the present study the pregnant ewe was used to evaluate the maternal and fetal cardiovascular and metabolic responses to hyperketonemia in the presence of hyperglycemia and to determine if the combined diabetic insults were more detrimental to the fetus than hyperketonemia alone. A glucose priming dose of 25 gm was administered in the maternal femoral vein followed by a continuous glucose infusion of 200 mg/min to achieve steady maternal plasma glucose levels of 180 mg/dl. Once glucose levels were stable, beta-hydroxybutyrate was infused for 2 hours at a rate of 0.39 mmol/100 ml of uterine blood flow into both left and right uterine arteries. Infusion of glucose alone did not significantly alter fetal cardiovascular and blood gas parameters but did increase the fetal glucose level from 17 +/- 4 to 58 +/- 8 mg/dl. The simultaneous infusion of beta-hydroxybutyrate and glucose produced significant decreases in fetal PaO2 and oxygen content as were reported for hyperketonemia alone and significant time-related increases in fetal lactate levels and fetal heart rate. These data suggest that hyperketonemia in the pregnant ewe leads to quantitatively similar changes in oxygenation in both normoglycemic and hyperglycemic fetuses. These observations may in part help explain the increased perinatal mortality in the pregnant woman with uncontrolled diabetes.

Effect of histamine receptor agonists and antagonists on the uterine vasculature

Histamine H1 and H2 receptors are known to exist in uterine smooth muscle; however, neither receptor has been clearly identified in the uterine vasculature. In the present study, 12 nonpregnant ewes were chronically instrumented with catheters in the carotid artery, jugular vein, uterine arteries, and electromagnetic flow probes on the uterine arteries for continuous measurement of uterine blood flow. Dose response curves were determined for bolus injections of Histamine (1-10 micrograms), the H1 receptor agonist 2PEA (10-100 micrograms), and the H2 receptor agonist Dimaprit (30-300 micrograms) before H1 receptor blockade with pyrilamine, following H1 receptor blockade, and following H2 receptor blockade with metiamide. Uterine vasodilator responses to histamine and 2PEA were essentially abolished by pyrilamine, while responses to dimaprit were not altered. Following addition of metiamide, responses to histamine were reduced further and responses to dimaprit were abolished. Baseline uterine blood flow was not altered by either H1 or H2 receptor blockade or their combination. Intraarterial bolus injections of the mast cell histamine-releasing compound 48/80 (100-1000 micrograms) had no effect on uterine blood flow. These experiments demonstrate that the uterine vasculature of the ovine contains almost exclusively H1 receptors, does not contain compound 48/80 sensitive mast cells and is not dependent upon endogenous histamine to maintain blood flow.

Effect of maternal ketoacidemia on the pregnant ewe and the fetus

Poorly controlled diabetic pregnancies are associated with hyperglycemia and elevated ketones. While glucose is known to cross the placenta, there is limited information regarding the placental transfer of ketones and their associated cardiovascular and metabolic effects in the fetus. Thus, the present study was undertaken to evaluate the transfer of the ketoacid beta hydroxybutyrate across the ovine placenta and to determine the effects of this ketoacid on maternal and fetal physiologic and metabolic parameters. Pregnant ewes (110 to 120 days' gestation) were instrumented with catheters in the lateral branch of both uterine arteries, uterine veins, femoral artery, and femoral vein, and electromagnetic flow probes were placed on both middle uterine arteries. Catheters were placed in the fetal carotid artery and jugular vein, and a catheter and balloon were placed in the amniotic fluid. Beta hydroxybutyrate (0.39 mmole/100 ml of uterine blood flow) and antipyrine (00.27 mmole/100 ml of uterine blood flow) as a second reference marker, were infused simultaneously into the uterine arteries for a period of 2 hours. The beta hydroxybutyrate concentrations in the uterine vein increased to 5.93 +/- 1.32 mmoles/L, and were associated with a significant increase in maternal heart rate and a slight but significant reduction in uterine blood flow. No changes in maternal arterial blood gas values were noted. The concentration of beta hydroxybutyrate in the fetal carotid arteries increased from 0.01 +/- 0.01 mmole/l to 0.15 +/- 0.03 mmole/L, and were associated with a significant reduction in fetal PaO2 (24.2 +/- 0.9 to 17.9 +/- 1.9 mm Hg) and an elevation of fetal lactate levels (1.86 +/- 0.17 to 5.07 +/- 1.56 mmoles/L).

Cardiovascular and biochemical effects of infusion of beta hydroxybutyrate into the fetal lamb

Previous studies from our laboratory have shown that beta hydroxybutyrate crosses the ovine placenta in small amounts during maternal hyperketonemia and produces significant reductions in fetal PaO2 and increased fetal lactate levels. The present study evaluates the effects of fetal hyperketonemia on fetal and maternal cardiovascular and biochemical parameters. Pregnant ewes (110 to 120 days' gestation) were instrumented with catheters in the femoral artery, femoral vein, and uterine veins, and electromagnetic flow probes were placed on the middle uterine arteries. The fetal carotid artery and jugular vein were catheterized, and a catheter and balloon were placed in the amniotic fluid. Beta hydroxybutyrate (0.44 mmole/min) and antipyrine (0.03 mmole/min) were simultaneously infused directly into the fetal jugular vein for 90 minutes. The fetal beta hydroxybutyrate level increased from a baseline of 0.12 +/- 0.08 to 6.80 +/- 0.46 mmoles/L and was associated with a significant decrease in fetal PaO2 (23.7 +/- 2.4 to 16.0 +/- 0.4 mm Hg) and a large increase in the fetal lactate (1.85 +/- 0.27 to 5.43 +/- 0.92 mmoles/L) at 90 minutes. The present results suggest that during fetal hyperketonemia fetal oxygenation is significantly reduced and may contribute to the increased perinatal mortality in the pregnant diabetic patient.

Effect of the prostacyclin synthetase inhibitor tranylcypromine on uterine blood flow in pregnancy

Prostacyclin is a potent vasodilator in a number of vascular beds including the uterus. However, the role of prostacyclin in maintaining uterine blood flow during pregnancy is not well established. Recent reports have appeared suggesting that tranylcypromine can selectively inhibit prostacyclin synthesis. Thus, the present study was undertaken using an unanesthetized chronically catheterized pregnant sheep preparation to evaluate the effects of direct intra-arterial infusions of tranylcypromine on the uterine vasculature of late-term pregnant ewes. Infusions of 1,3 and 10 mg/min of tranylcypromine led to dose-related reduction in uterine blood flow (16, 21 and 47 percent, respectively) and increased blood pressure (7, 10 and 23 percent, respectively). However, these alterations were not associated with reductions in the uterine production rates of the prostacyclin metabolite, 6-keto-PGF1alpha, as determined by unextracted plasma RIA. In addition, pre-treatment of animals with the alpha-adrenergic blocking agent, phenoxybenzamine, almost totally abolished uterine and systemic blood pressure responses to tranylcypromine. These data suggest that tranylcypromine either releases or elevates levels of an alpha adrenergic stimulant which constricts the uterine and systemic vasculature and does not alter prostacyclin levels at the dose tested.

The Capture of Fauna other than FIshes in Eel and Mesh Nets

The effects of eel (fyke) and mesh nets on fauna other than fishes were studied over 21 months from July 1975 to March 1977, at Macleods Morass, Vic. Tortoises were caught 272 times, birds five times and mammals twice in nets set to catch fishes. All fauna except two tortoises, two birds and the two mammals were released unharmed. Methods for preventing such animals being caught are suggested.