Effects of copper and zinc on embryos and larvae of the horseshoe crab, limulus polyphemus

We investigated the short-term and long-term effects of copper and zinc on horseshoe crab (Limulus polyphemus) embryos and first instar larvae from two estuaries in New Jersey, Delaware Bay and Sandy Hook Bay. Animals were exposed to nominal metal concentrations from 0.01 to 1,000 mg/L for 24 h, 48 h, 72 h, or continuously until the endpoint for the study (successful molting or death) was reached. Larvae showed greater tolerance of Cu and Zn than embryos. Under most treatment regimes, embryos and larvae were able to survive and molt in the presence of up to 100 mg/L Cu or Zn. Unexpectedly, horseshoe crabs from the more heavily polluted site (Sandy Hook Bay) were more susceptible to heavy metals than animals from a less polluted site (lower Delaware Bay). Horseshoe crab embryos and larvae were highly resistant to heavy metals in comparison to marine crustacea. The ability of Limulus embryos and larvae to survive in the presence of heavy metals implies the potential for these contaminants to be passed on to shorebirds and other predators.

Effects of a circumferentially vented mask on breathing patterns of women as measured by respiratory kinematic techniques

Since pneumotachograph masks are commonly used in studies of speech breathing, the purpose of this study was to measure the differences in respiratory volumetric and frequency measures during speech under two conditions: with and without a circumferentially vented pneumotachograph mask coupled to the face. Thus we sought to identify whether changes in breathing patterns occur with the use of a specific face mask, because these patterns are accepted as representative of normal speech breathing. Subjects were 10 normal-speaking women, each of whom produced a syllable train and a connected speech task, both at comfortable intensity levels. Respiratory measures were made using linearized magnetometers during speech production. The measurements included lung volume, rib cage volume, and abdominal volume at utterance initiation and termination, volume excursions during the utterance, and the number of breath groups during the speech task. There were no significant differences between the mask-on and mask-off conditions in volumetric and frequency measures. A significant task difference for abdominal initiation was found. It was concluded that the use of a circumferentially vented pneumotachograph mask does not alter the reliability of respiratory volume and frequency measures for studies of voice.

The politics of EPSDT policy in the 1990s: policy entrepreneurs, political streams, and children's health benefits

The Early and Periodic Screening, Diagnosis and Treatment (EPSDT) program, which was designed to ensure that Medicaid-eligible children receive comprehensive health services, is the only national attempt to provide a right to these services. The political factors that have shaped national EPSDT policy during the past decade are described, based on a conceptual framework developed by John W. Kingdon. The analysis focuses on the roles of two distinct sets of policy entrepreneurs: child health advocates and fiscally conservative governors. Their activities are described in relation to the larger political environment, or "political stream," from the period of the expansion of Medicaid eligibility for pregnant women and children in the late 1980s to the enactment of a new State Children's Health Insurance Program (SCHIP) in 1997. The relative saliency of eligibility and benefit issues in children's health policies had a major influence on the politics and outcomes.

Bone morphogenetic proteins and bFGF exert opposing regulatory effects on PTHrP expression and inorganic pyrophosphate elaboration in immortalized murine endochondral hypertrophic chondrocytes (MCT cells)

A fundamental question in endochondral development is why the expression of parathyroid hormone-related protein (PTHrP), which inhibits chondrocyte maturation and mineralization, becomes attenuated at the stage of chondrocyte hypertrophy. To address this question, we used clonal, phenotypically stable SV40-immortalized murine endochondral chondrocytes that express a growth-arrested hypertrophic phenotype in culture (MCT cells). Addition of individual cytokines to the medium of MCT cells revealed that bone morphogenetic protein (BMP)-6, which commits chondrocytes to hypertrophy, markedly inhibited PTHrP production. This activity was shared by three other osteogenic bone morphogenetic proteins (BMP-2, BMP-4, and BMP-7) and by transforming growth factor beta (TGF-beta), which all inhibited the level of PTHrP mRNA. In contrast, basic fibroblast growth factor (bFGF), an inhibitor of chondrocyte maturation to hypertrophy, induced PTHrP in MCT cells and antagonized the effects of BMP-2, BMP-4, BMP-6, and BMP-7 and TGF-beta on PTHrP expression. Opposing effects of bFGF and BMPs also were exerted on the elaboration of inorganic pyrophosphatase (PPi), which regulates the ability of hypertrophic chondrocytes to mineralize the matrix. Specifically, BMP-2 and BMP-4, but not BMP-6 and BMP-7, shared the ability of TGF-beta to induce PPi release, and this activity was inhibited by bFGF in MCT cells. Our results suggest that effects on PTHrP expression could contribute to the ability of BMP-6 to promote chondrocyte maturation. BMPs and bFGF exert opposing effects on more than one function in immortalized hypertrophic chondrocytes. Thus, the normal decrease in bFGF responsiveness that accompanies chondrocyte hypertrophy may function in part by removing the potential for bFGF to induce PTHrP expression and to oppose the effects of BMPs. MCT cells may be useful in further understanding the mechanisms regulating the differentiation and function of hypertrophic chondrocytes.

Potential mechanisms for a proinflammatory vascular cytokine response to coagulation activation

We have previously shown that an anticoagulant could attenuate inflammation in animal models of sepsis with disseminated intravascular coagulation (DIC) and that coagulation activation of human whole blood ex vivo results in a proinflammatory cytokine response. The current studies were performed to better understand mechanisms for the blood cell cytokine response and extend the investigation of such a response to endothelial cells as likely contributors to a vascular inflammatory response. Utilizing cell separation techniques, it was determined that the whole blood IL-8 response to coagulation activation or thrombin, specifically, was mediated by CD14+ monocytes. Moreover, thrombin was observed to stimulate both IL-8 and IL-6 production in cultured mononuclear cells. Analyses of the effects of coagulation activation and thrombin were extended to cultured human endothelial cells, and a similar cytokine response was observed. Thrombin catalytic activity appeared essential, since hirudin reduced thrombin-stimulated proinflammatory cytokine production in cultured monocytes and endothelial cells and prothrombin only weakly mimicked the thrombin response. The endothelial cell IL-8 and IL-6 response to thrombin could be mimicked by the thrombin receptor agonist peptide (TRAP), implicating a functional role of the classic thrombin receptor. Altogether, the results facilitate a better understanding of potential proinflammatory vascular responses to coagulation activation.

Neuronal overexpression of heme oxygenase-1 correlates with an attenuated exploratory behavior and causes an increase in neuronal NADPH diaphorase staining

Heme oxygenase isozymes, HO-1 (also known as hsp32) and HO-2, are the source for the formation of the putative messenger molecule carbon monoxide (CO), reactive iron, and the in vitro antioxidant bilirubin. We have developed and characterized transgenic (Tg) mice that overexpress the stress protein in neurons in various brain regions. The Tg mice were generated by the use of rat HO-1 cDNA under the control of the neuron-specific enolase promoter. Except for a tendency to have an enlarged spleen, Tg mice did not show gross anatomical changes. Increase in HO-1 mRNA, which was demonstrated by northern blot analysis and in situ hybridization, was accompanied by an increase in neuronal HO-1 protein expression, shown by immunohistochemistry and western blotting, and an increase in HO activity. Expression of the transgene correlated with an attenuation of exploratory behavior and increased circling activity and coincided with enhanced neuronal NADPH diaphorase staining. Those changes were not accompanied by an increase in DNA damage or significant change in whole-brain NO synthase activity. The HO-1 Tg mice potentially represent a good model to examine the function of CO as a neuromodulator, iron as a gene regulator, and bile pigments as in vivo antioxidants.

Mechanisms of inactivation of E-cadherin in breast cancer cell lines

Loss of E-cadherin (CDH1) function is thought to contribute to progression in breast cancer and other solid tumors by increasing proliferation, invasion, and/or metastasis. In some cases, the restoration of CDH1 function may be an important therapeutic option. This possibility will depend on the mechanism by which CDH1 is inactivated. Here we present analyses of CDH1 expression, genetic mutation, and promoter methylation in CDH1 in 10 commonly used breast cancer cell lines. Five cell lines (BT-474, MCF-7, MDA-MB-361, MDA-MB-468, and T-47D) expressed CDH1 and were genetically normal. Five others (SK-BR-3, 600 MPE, MDA-MB-134 IV, CAMA1, and MDA-MB-435) did not express CDH1. Fluorescence in situ hybridization analyses of each of these cell lines showed evidence for the physical deletion of one allele of CDH1, and three cell lines were found to carry homozygous deletions. SK-BR-3 was deleted from exon 12 through the promoter; exon 6 was deleted in MDA-MB-134 IV cells, and 600 MPE cells carried a 21-bp deletion in the splicing acceptor site for exon 9. CAMA1 seemed to have been inactivated through promoter methylation. No explanation was found for the inactivation of CDH1 in MDA-MB-435.

Tobacco, alcohol, and drug use in a primary care sample: 90-day prevalence and associated factors

BACKGROUND

Primary care settings are an ideal system in which to identify and treat substance use disorders.

OBJECTIVE

To ascertain the prevalence of tobacco, alcohol, and drug use in the office of 88 primary care clinicians by gender, age and ethnicity.

METHOD

21,282 adults ages 18-65 completed a self-administered Health Screening Survey while participating in a trial for early alcohol treatment.

RESULTS

The period prevalence of tobacco use was 27%. For alcohol: abstainers 40%, low risk drinkers 38%, at-risk drinkers 9%, problem drinkers 8%, and dependent drinkers 5%. Twenty percent of the sample reported using illicit drugs five or more times in their lifetime and 5% reported current illicit drug use. There were marked differences in alcohol use disorders by age and ethnicity. The majority of persons who smoked reported the desire to cut down or stop using tobacco.

SIGNIFICANCE

This is the first report on the combined prevalence of tobacco, alcohol and drug disorders in a large sample of persons attending community-based non-academic primary care clinics. This report confirms the high prevalence of these problems and suggests that patients will accurately complete a self-administered screening test such as the Health Screening Survey. The office procedures developed for this study provide Managed Care Organizations with a system of care that can be used to screen all persons for tobacco, alcohol and drug use disorders.

Hypotension and inflammatory cytokine gene expression triggered by factor Xa-nitric oxide signaling

The signaling pathway initiated by factor Xa on vascular endothelial cells was investigated. Factor Xa stimulated a 5- to 10-fold increased release of nitric oxide (NO) in a dose-dependent reaction (0.1-2.5 microG/ml) unaffected by the thrombin inhibitor hirudin but abolished by active site inhibitors, tick anticoagulant peptide, or Glu-Gly-Arg-chloromethyl ketone. In contrast, the homologous clotting protease factor IXa or another endothelial cell ligand, fibrinogen, was ineffective. A factor Xa inter-epidermal growth factor synthetic peptide L (83)FTRKL(88) (G) blocking ligand binding to effector cell protease receptor-1 inhibited NO release by factor Xa in a dose-dependent manner, whereas a control scrambled peptide KFTGRLL was ineffective. Catalytically active factor Xa induced hypotension in rats and vasorelaxation in the isolated rat mesentery, which was blocked by the NO synthase inhibitor L-N(G)-nitroarginine methyl ester (L-NAME) but not by D-NAME. Factor Xa/NO signaling also produced a dose-dependent endothelial cell release of interleukin 6 (range 0.55-3.1 ng/ml) in a reaction inhibited by L-NAME and by the inter-epidermal growth factor peptide Leu(83)-Leu(88) but unaffected by hirudin. Maximal induction of interleukin 6 mRNA required a brief, 30-min stimulation with factor Xa, unaffected by subsequent addition of tissue factor pathway inhibitor. These data suggest that factor Xa-induced NO release modulates endothelial cell-dependent vasorelaxation and cytokine gene expression. This pathway requiring factor Xa binding to effector cell protease receptor-1 and a secondary step of ligand-dependent proteolysis may preserve an anti-thrombotic phenotype of endothelium but also trigger acute phase responses during activation of coagulation in vivo.

The circulating common gamma chain (CD132) in inflammatory bowel disease

OBJECTIVE

Inflammatory bowel disease (IBD) is characterized by T cell activation. Activated T cells shed interleukin-2 receptors (IL-2R) in a soluble form. A positive correlation between sIL-2Ralpha (CD25) and disease activity is well documented in IBD, whereas IL-2Rgamma (CD132) has not been investigated in this respect. Sera from 42 patients with ulcerative colitis (UC), 34 with Crohn's disease (CD), 31 healthy volunteers, and 12 patients with infectious enterocolitis were obtained.

METHODS

Disease activity was scored according to a semiquantitative score for UC and CD. sIL-2R alpha chain and gamma chain were assessed by sandwich ELISA techniques using monoclonal antibodies specific for CD25 and CD132, respectively.

RESULTS

The concentration of IL-2Ralpha chain (CD25) was found to be median 3.8 ng/ml in healthy volunteers versus 7.0 ng/ml in UC patients (p < 0.001), and 9.6 ng/ml in CD patients (p < 0.001). With respect to IL-2Rgamma (CD132), significantly higher amounts were found in CD patients: 6.6 ng/ml as compared with healthy controls <1.0 ng/ml (p < 0.004). A Kruskal-Wallis test revealed a significant correlation between alpha chain and disease activity in CD (p < 0.001), and further significantly higher gamma chain levels were found in active CD (p = 0.03). For UC patients, a statistically significant increase of the alpha chain with increasing disease activity (p < 0.01) was observed, whereas no significant changes of the gamma chain levels were found (p > 0.05). A difference of gamma chain levels were found between CD and UC in moderate and severe disease activity (p < 0.05). Further analyses revealed that mesalazine did not influence the IL-2Ralpha or -gamma concentration either in UC or in CD patients.

CONCLUSION

An increased circulating level of the soluble common gamma chain (CD132) seems to be found in CD, and an overlap exists between CD and UC.

Side-to-side aorto-Gore-Tex central shunt

BACKGROUND

This report details our experience in 13 patients with a technical modification of the standard central shunt.

METHODS

The study was performed using a retrospective chart review approach. In our operation, the aorto-Gore-Tex (W.L. Gore & Assoc, Flagstaff, AZ) anastomosis is created in a side-to-side fashion with the free end of the Gore-Tex shunt being oversewn.

RESULTS

All patients had echocardiographic evidence of shunt patency in the immediate postoperative period, and there have been no cases of late shunt occlusion at a mean follow-up period of 10 months.

CONCLUSIONS

We believe this approach will yield patency rates equivalent to or better than those of the standard central shunt. The technique has the advantage of creating a short, straight-lying shunt that is less likely to kink or be injured on repeated sternotomy and in which flow may be more reliable.

Caprine mucopolysaccharidosis-IIID: clinical, biochemical, morphological and immunohistochemical characteristics

Several animal models have been developed for the mucopolysaccharidoses (MPSs), a group of lysosomal storage disorders caused by lysosomal hydrolase deficiencies that disrupt the catabolism of glycosaminoglycans (GAG). Among the MPS, the MPS-III (Sanfilippo) syndromes lacked an animal counterpart until recently. In this investigation of caprine MPS-IIID, the clinical, biochemical, morphological, and immunohistochemical studies revealed severe and mild phenotypes like those observed in human MPS III syndromes. Both forms of caprine MPS IIID result from a nonsense mutation and consequent deficiency of lysosomal N-acetylglucosamine 6-sulfatase (G6S) activity and are associated with tissue storage and urinary excretion of heparan sulfate (HS). Using special stains, immunohistochemistry, and electron microscopy, secondary lysosomes filled with GAG were identified in most tissues from affected goats. Primary neuronal accumulation of HS and the secondary storage of gangliosides were observed in the central nervous system (CNS) of these animals. In addition, morphological changes in the CNS such as neuritic expansions and other neuronal alterations that may have functional significance were also seen. The spectrum of lesions was greater in the severe form of caprine MPS IIID and included mild cartilaginous, bony, and corneal lesions. The more pronounced neurological deficits in the severe form were partly related to a greater extent of CNS dysmyelination. These findings demonstrate that caprine MPS IIID is a suitable animal model for the investigation of therapeutic strategies for MPS III syndromes.

The effect of using "race of child" instead of "race of mother" on the black-white gap in infant mortality due to birth defects

OBJECTIVE

For at least 20 years, birth defects have been the leading cause of infant mortality in the United States. Some studies have reported higher rates for black infants than white infants of mortality due to birth defects, while other studies have reported no black-white differences. The authors analyzed the effect on these rates of a change in the way the National Center for Health Statistics (NCHS) tabulates "race" for newborns.

METHODS

The authors calculated infant mortality rates due to birth defects for 1980-1993 using two standard methods of assigning newborns to "racial" categories: a "race of child" algorithm and the "race of mother" approach currently used by NCHS.

RESULTS

From 1980 through 1993, birth defect-specific infant mortality rates (BD-IMRs) were significantly higher for black infants than white infants 12 of the 14 years by "race of mother" and only 5 of 14 years by "race of child." Calculation of BD-IMRs by "race of mother" reduced the rate for white infants and increased the rate for black infants in each of the 14 years. The choice of method for assigning newborns to "racial" categories had a progressively greater effect over time on the black-white gap in BD-IMRs.

CONCLUSIONS

Calculations of trends in "race"-specific BD-IMRs by may vary substantially by whether "race of mother" or "race of child" is used. Identifying the method of tabulation is imperative for appropriate comparisons and interpretations.

Utilization of a paediatric link collection by health professionals and laypersons

The Internet is an evolving resource for health-care information. However little information exists on providers' and other web patrons' usage of the 'medical' Internet. This study aims to characterize the users of a large paediatric link collection, describe their objectives and track their use of the information provided by the site. We utilized a paediatric link collection called the Pediatric Points of Interest (POI) and a combination of a questionnaire, unique user identifier and link-tracking system to collect data about POI patrons' demographics and Internet resource utilization. During a five week period, 5216 individuals visited the POI and requested 36,187 links. The majority of users had less than one year of Internet experience and were first-time visitors to the POI. More than 83% of users were from North America. Medical professionals were more likely to return to the POI during the study period and reported visiting the POI mainly for 'medical education', 'research', 'resource identification', and 'disease specific information'; they proceeded primarily to the resource categories 'Medical Institutions and Agencies' (32%) and 'Professional Education and Resources' (28%). Laypersons expressed the greatest interest in 'disease specific information' and 'patient education' and most frequently visited the category. 'Patient Education' (42%). On average, users were able to identify resources related to their stated goals within one level of searching. Health care providers and other web patrons are actively utilizing Internet sites to seek medical information and are able to identify resources with a minimum of searching.

The children's hour: the State Children's Health Insurance Program

The State Children's Health Insurance Program (CHIP) is the product of a series of policy and political compromises and generates numerous structural and policy issues for states. CHIP entitles states to federal financial aid to provide health assistance to targeted children, through Medicaid expansions, new program implementation, or a product of the two. States that elect to operate CHIP programs apart from Medicaid have enormous discretion under the law to determine how they will structure their programs, the services they will cover, the form that benefits will take, and the conditions of participation and consumer protections that will apply. Determining what approach to take, as well as how to respond to the choices posed by the statute, represents a major test of how states address the needs of children and families.

At-risk drinking in an HMO primary care sample: prevalence and health policy implications

OBJECTIVES

This study was designed to determine the prevalence of at-risk drinking using varying alcohol use criteria.

METHODS

A period prevalence survey was conducted in 22 primary care practices (n = 19372 adults).

RESULTS

The frequency of at-risk alcohol use varied from 7.5% (World Health Organization criteria) to 19.7% (National Institute on Alcohol Abuse and Alcoholism criteria). A stepwise logistic model using National Institute on Alcohol Abuse and Alcoholism criteria found male gender, current tobacco use, never married status, retirement, and unemployment to be significant predictors of at-risk alcohol use.

CONCLUSIONS

Public health policy needs to move to a primary care paradigm focusing on identification and treatment of at-risk drinkers.

Mammography use among women attending an inner-city clinic

BACKGROUND

Low-income, minority, and inner city women have breast cancer screening rates that are below those of the general population.

METHODS

The authors surveyed women who received primary care at Seattle's county hospital about their mammography behaviors in early 1995. Data were analyzed within the context of the PRECEDE framework.

RESULTS

Only half (48%) of the women were obtaining regular screening. Breast cancer and mammography beliefs differed by racial group. The following factors differentiated between inner-city women who were and were not regular users: mammography beliefs concerning early detection of disease, pressure from the machine causing breast cancer, and cost (these were less important among white women than members of other racial groups); previous physician discussions, concerns about appointment scheduling, and transportation problems; and social support from physicians, family, and friends.

CONCLUSION

Interventions to encourage regular screening among inner-city women should address predisposing, enabling, and reinforcing factors.

Hyperoxia exacerbates microvascular lung injury following acid aspiration

OBJECTIVES

To examine the effects of an increase in ambient oxygen (O2) concentrations on the extent of inflammatory pulmonary damage following acid aspiration.

DESIGN

Prospective, controlled laboratory study.

SETTINGS

University-affiliated animal research facility.

SUBJECTS

Male, Long Evans rats weighing 250 to 300 g.

INTERVENTION

Rats were injured by instillation of 1.2 mL/kg normal saline solution/HCl, pH= 1.25 (acid), into the lungs via a tracheotomy. Animals were allowed to awaken and were exposed to 21%, 50%, or 98% O2 for 0 to 5 h (n/group > or = 10). In a separate set of experiments, injured rats exposed to 98% O2 were treated with different doses of deferoxamine, just prior to injury. Uninjured rats and rats injured with normal saline solution, pH = 5.3, were used as the control group.

MEASUREMENTS

Injury was determined by assessing lung function (lung compliance and arterial blood gases) and alveolar-capillary wall integrity (wet/dry weight, lung albumin permeability index [PI], and intrapulmonary hemorrhage [HI]).

RESULTS

Intrapulmonary instillation of acid increased PI, HI, and decreased static lung compliance compared to uninjured control animals. Increased ambient oxygen following acid aspiration decreased lung compliance, 1.06+/-0.03 mL/kg/cm H2O, in oxygen-exposed lungs when compared to the lungs exposed to air, 1.26+/-0.04, following a low pH aspirate (p<0.05). An increase in protein leakage into the lung tissue was noted in oxygen-exposed animals, PI=1.33+/-0.10, vs air-exposed rats, 0.89+/-0.07 (p<0.05). The hyperoxia-induced increase in lung injury was prevented by 30 mg/kg or higher deferoxamine treatment, 0.78+/-0.05 (p<0.05). Exposure of animals to 98% O2 for 2 h was sufficient to produce the same increase in microvascular protein leakage as 5-h exposure to O2 following low pH aspirate.

CONCLUSION

Hyperoxia increases acid aspiration-induced inflammatory microvascular lung injury. This appears to be mediated by production of reactive species of O2.