Bridging Epidemiological Data with Features of the Urban Context: An experience of Urban Public Health within the City of Milan, Italy

Referring to the Research Project “Enhancing Healthcare and Well-Being Through the Potential of Big Data: An Integration of Survey, Administrative, and Open Data to Assess Health Risk in the City of Milan with Data Science” the Authors present preliminary results regarding a survey distributed to a sample of citizens across all neighborhoods of Milano city. This survey sought to collect data regarding health risk factors of this population, including both individual (e.g. socio-demographic characteristics, behaviors, etc.) and community (e.g. environmental/morphological features, available social services, etc.) data. A digital survey was designed to collect information on the health conditions, risk factors, and lifestyle characteristics of a representative sample of the Milanese population at the neighborhood level, with reference to the census tracts and Local Identity Units (NIL). Collected survey data are entered into a system containing corresponding individual health information acquired from the Local Health Authority databases, creating a synthesized information profile with each respondent's state of health, including existing conditions, health services used, and drug therapies. The disseminated survey was developed from comparisons with similar experiences at the national/international level and divided into 60 multiple choice questions (6 for Sociodemographic profile; 8 for Context of residence; 12 for Functional limitations; 25 for Behaviors and lifestyles; 9 for Access to health services). The data from urban analysis conducted on the NIL of the City of Milan are assessed with particular reference to the theme of bicycle-pedestrian accessibility (Walkability) in the urban context and repercussions on the adoption of Healthy Lifestyles. The models developed through this research are expected to provide critical insight for designing health promotion, health protection, and disease prevention interventions aimed both at individual and community level.

The N-linker region of hERG1a upregulates hERG1b potassium channels

A major physiological role of hERG1 (human Ether-á-go-go-Related Gene 1) potassium channels is to repolarize cardiac action potentials. Two isoforms, hERG1a and hERG1b, associate to form the potassium current IKr in cardiomyocytes. Inherited mutations in hERG1a or hERG1b cause prolonged cardiac repolarization, long QT syndrome, and sudden death arrhythmia. hERG1a subunits assemble with and enhance the number of hERG1b subunits at the plasma membrane, but the mechanism for the increase in hERG1b by hERG1a is not well understood. Here, we report that the hERG1a N-terminal region expressed in trans with hERG1b markedly increased hERG1b currents and increased biotin-labeled hERG1b protein at the membrane surface. hERG1b channels with a deletion of the N-terminal 1b domain did not have a measurable increase in current or biotinylated protein when coexpressed with hERG1a N-terminal regions, indicating that the 1b domain was required for the increase in hERG1b. Using a biochemical pull-down interaction assay and a FRET hybridization experiment, we detected a direct interaction between the hERG1a N-terminal region and the hERG1b N-terminal region. Using engineered deletions and alanine mutagenesis, we identified a short span of amino acids at positions 216 to 220 within the hERG1a "N-linker" region that were necessary for the upregulation of hERG1b. We propose that direct structural interactions between the hERG1a N-linker region and the hERG1b 1b domain increase hERG1b at the plasma membrane. Mechanisms regulating hERG1a and hERG1b are likely critical for cardiac function, may be disrupted by long QT syndrome mutants, and serve as potential targets for therapeutics.

Gating and regulation of KCNH (ERG, EAG, and ELK) channels by intracellular domains

The KCNH family comprises the ERG, EAG, and ELK voltage-activated, potassium-selective channels. Distinct from other K channels, KCNH channels contain unique structural domains, including a PAS (Per-Arnt-Sim) domain in the N-terminal region and a CNBHD (cyclic nucleotide-binding homology domain) in the C-terminal region. The intracellular PAS domains and CNBHDs interact directly and regulate some of the characteristic gating properties of each type of KCNH channel. The PAS-CNBHD interaction regulates slow closing (deactivation) of hERG channels, the kinetics of activation and pre-pulse dependent population of closed states (the Cole-Moore shift) in EAG channels and voltage-dependent potentiation in ELK channels. KCNH channels are all regulated by an intrinsic ligand motif in the C-terminal region which binds to the CNBHD. Here, we focus on some recent advances regarding the PAS-CNBHD interaction and the intrinsic ligand.

Calcium and Vitamin D Use among Older Adults in U.S.: Results from National Survey

OBJECTIVE

This study was conducted to describe a 10-year trend of the supplement from 2000 to 2009 and to evaluate age, gender and racial disparities using a national level health data.

DESIGN

Cross-sectional observational study.

SETTING AND PARTICIPANTS

Data collected from patient visit records to stand-alone US ambulatory care clinics. Visits made by men and women who were 40 years of age and older were included (n=175,830).

MEASUREMENTS

Overall prevalence of recorded calcium and vitamin D use for osteoporosis prevention and treatment, and annual visit rates were estimated by age, gender, race, insurance types, physician specialties, geographical regions, and metropolitan status using chi square test. Multivariate logistic regression was conducted to determine potential predictive factors for calcium and vitamin D supplements.

RESULTS

An increase in yearly trend of calcium and vitamin D supplements was observed. The increase was proportional to patients' age (p<0.05) and female gender was a strong predictor of calcium and vitamin D supplement (p<0.0001).Visits made by blacks were significantly less likely to be associated with the supplement (<0.05). Visits associated with self-pay and Medicaid was less likely to be recorded with vitamin D (p<0.05) but not calcium supplements. Osteoporosis diagnosis was an independent predictor of calcium and vitamin D records (p<0.0001).

CONCLUSIONS

In spite of the observed increases in the trend of visits associated with calcium and vitamin D supplements, variability in the access to the medications was observed. More focused strategies targeting elderly, men, or black population are needed to maintain and improve adequate calcium and vitamin D supplements.

Tip60 HAT activity mediates APP induced lethality and apoptotic cell death in the CNS of a Drosophila Alzheimer's disease model

Histone acetylation of chromatin promotes dynamic transcriptional responses in neurons that influence neuroplasticity critical for cognitive ability. It has been demonstrated that Tip60 histone acetyltransferase (HAT) activity is involved in the transcriptional regulation of genes enriched for neuronal function as well as the control of synaptic plasticity. Accordingly, Tip60 has been implicated in the neurodegenerative disorder Alzheimer's disease (AD) via transcriptional regulatory complex formation with the AD linked amyloid precursor protein (APP) intracellular domain (AICD). As such, inappropriate complex formation may contribute to AD-linked neurodegeneration by misregulation of target genes involved in neurogenesis; however, a direct and causative epigenetic based role for Tip60 HAT activity in this process during neuronal development in vivo remains unclear. Here, we demonstrate that nervous system specific loss of Tip60 HAT activity enhances APP mediated lethality and neuronal apoptotic cell death in the central nervous system (CNS) of a transgenic AD fly model while remarkably, overexpression of Tip60 diminishes these defects. Notably, all of these effects are dependent upon the C-terminus of APP that is required for transcriptional regulatory complex formation with Tip60. Importantly, we show that the expression of certain AD linked Tip60 gene targets critical for regulating apoptotic pathways are modified in the presence of APP. Our results are the first to demonstrate a functional interaction between Tip60 and APP in mediating nervous system development and apoptotic neuronal cell death in the CNS of an AD fly model in vivo, and support a novel neuroprotective role for Tip60 HAT activity in AD neurodegenerative pathology.

West Nile virus infection and serologic response among persons previously vaccinated against yellow fever and Japanese encephalitis viruses

It is hypothesized that previous heterologous flaviviral exposure may modulate clinical illness among persons infected with West Nile virus (WNV). Little is known about the serological response in such persons. In summer 2003, a WNV outbreak occurred in Colorado, the location of the Centers for Disease Control and Prevention, Division of Vector-Borne Infectious Diseases (DVBID). DVBID employees, most previously vaccinated with yellow fever virus (YFV) or Japanese encephalitis virus (JEV) vaccines, were studied to determine whether previous vaccination affected symptom development among those subsequently infected with WNV during the outbreak, as well as their serological response. Serum samples collected in December 2003 and previously banked samples were tested using the plaque reduction neutralization test (PRNT) against WNV, Saint Louis encephalitis virus, dengue- 4 virus, JEV, and YFV. Specimens shown to have WNV antibody by PRNT were tested by IgM and IgG enzymelinked immunosorbent assays (ELISAs). Ten (9%) of 113 serosurvey participants had WNV neutralizing antibody titers in December 2003. PRNT titers from previous specimens showed that one of the ten had seroconverted to WNV before 2003. Of the remaining nine participants, seven reported illness in the summer of 2003, two of which were unvaccinated and five previously vaccinated. In the December 2003 specimens, five persons previously unvaccinated or vaccinated only against YFV had a fourfold or greater neutralizing titer with WNV than with other flaviviruses, whereas no persons previously vaccinated against JEV or JEV and YFV showed a similar difference in neutralizing titers. Eight of nine persons infected in 2003 had negative or indeterminate WNV MAC-ELISA results in the December 2003 sample; the ninth person was vaccinated against YFV one month previously, and was also YFV positive by MAC-ELISA. We conclude that previous flaviviral vaccination does not markedly affect the development of WNV fever and that the IgM antibody response in patients without neuroinvasive WNV disease is transient.

Serum levels of mannan-binding lectin in chickens prior to and during experimental infection with avian infectious bronchitis virus

Mannan-binding lectin (MBL) is a glycoprotein and a member of the C-type lectin super family, the collectin family, and the acute phase protein family. The MBL exerts its function by directly binding to microbial surfaces through its carbohydrate recognition domains, followed by direct opsonization or complement activation via MBL-associated serine proteases (MASP)-1 and -2. Thus, MBL plays a major role in the first-line innate defense against pathogens. We investigated the MBL concentrations in serum during experimental infectious bronchitis virus (IBV) infections in chickens. The results showed that the acute phase MBL response to infection with IBV was, to a degree (P < 0.0068), dependent on whether the chickens were inoculated after 12 h of rest (dark) or after 12 h of activity (light). The acute phase response in chickens challenged after 12 h of activity peaked after 4.6 d with an increase of 24%, whereas the acute phase response in chickens challenged after 12 h of rest peaked after 3.1 d with an increase of 51%. The specific antibody titer against IBV was also tested, and a difference (P < 0.0091) between the two experimental groups was found with peak titer values of 6,816 and 4,349. However, the highest value was found in chickens inoculated after 12 h of activity. Thus, an inverse relation exists between the MBL response and the IBV specific antibody response. The ability of MBL to activate the complement cascade was tested in a heterologous system by deposition of human C4 on the chicken MBL/MASP complex. The complement activation was directly associated with the concentration of MBL in serum, indicating neutralization of the virus before the humoral antibody response took over.

Toxicity of antiviral nucleoside analogs and the human mitochondrial DNA polymerase

To examine the role of the mitochondrial polymerase (Pol gamma) in clinically observed toxicity of nucleoside analogs used to treat AIDS, we examined the kinetics of incorporation catalyzed by Pol gamma for each Food and Drug Administration-approved analog plus 1-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl)-5-iodouracil (FIAU), beta-L-(-)-2',3'-dideoxy-3'-thiacytidine (-)3TC, and (R)-9-(2-phosphonylmethoxypropyl)adenine (PMPA). We used recombinant exonuclease-deficient (E200A), reconstituted human Pol gamma holoenzyme in single turnover kinetic studies to measure K(d) (K(m)) and k(pol) (k(cat)) to estimate the specificity constant (k(cat)/K(m)) for each nucleoside analog triphosphate. The specificity constants vary more than 500,000-fold for the series ddC > ddA (ddI) > 2',3'-didehydro-2',3'-dideoxythymidine (d4T) >> (+)3TC >> (-)3TC > PMPA > azidothymidine (AZT) >> Carbovir (CBV). Abacavir (prodrug of CBV) and PMPA are two new drugs that are expected to be least toxic. Notably, the higher toxicities of d4T, ddC, and ddA arose from their 13-36-fold tighter binding relative to the normal dNTP even though their rates of incorporation were comparable with PMPA and AZT. We also examined the rate of exonuclease removal of each analog after incorporation. The rates varied from 0.06 to 0.0004 s(-1) for the series FIAU > (+)3TC approximately equal to (-)3TC > CBV > AZT > PMPA approximately equal to d4T >> ddA (ddI) >> ddC. Removal of ddC was too slow to measure (<0.00002 s(-1)). The high toxicity of dideoxy compounds, ddC and ddI (metabolized to ddA), may be a combination of high rates of incorporation and ineffective exonuclease removal. Conversely, the more effective excision of (-)3TC, CBV, and AZT may contribute to lower toxicity. FIAU is readily extended by the next correct base pair (0.13 s(-1)) faster than it is removed (0.06 s(-1)) and, therefore, is stably incorporated and highly mutagenic. We define a toxicity index for chain terminators to account for relative rates of incorporation versus removal. These results provide a method to rapidly screen new analogs for potential toxicity.

Fidelity of nucleotide incorporation by human mitochondrial DNA polymerase

We have examined the fidelity of polymerization catalyzed by the human mitochondrial DNA polymerase using wild-type and exonuclease-deficient (E200A mutation) forms of recombinant, reconstituted holoenzyme. Each of the four nucleotides bind and incorporate with similar kinetics; the average dissociation constant for ground state binding is 0.8 microm, and the average rate of polymerization is 37 x s(-1), defining a specificity constant kcat/Km = 4.6 x 10(7) x m(-1) x s(-1). Mismatched nucleotides show weaker ground-state nucleotide binding affinities ranging from 57 to 364 microm and slower rates of polymerization ranging from 0.013 to 1.16 x s(-1). The kinetic parameters yield fidelity estimates of 1 error out of 260,000 nucleotides for a T:T mismatch, 3563 for G:T, and 570,000 for C:T. The accessory subunit increases fidelity 14-fold by facilitating both ground-state binding and the incorporation rate of the correct A:T base pair compared with a T:T mismatch. Correctly base-paired DNA dissociates from the polymerase at a rate of 0.02 x s(-1) promoting processive polymerization. Thus, the mitochondrial DNA polymerase catalyzed incorporation with an average processivity of 1850, defined by the ratio of polymerization rate to the dissociation rate (37/0.02) and with an average fidelity of one error in 280,000 base pairs.

Exonuclease proofreading by human mitochondrial DNA polymerase

We have examined the ability of the human mitochondrial DNA polymerase to correct errors in DNA sequence using single turnover kinetic methods. The rate of excision of single-stranded DNA ranged from 0.07 to 0.17 x s(-1), depending on the identity of the 3'-base. Excision of the 3'-terminal base from correctly base paired DNA occurred at a rate of 0.05 x s(-1), indicating that the cost of proofreading is minimal, as defined by the ratio of the k(exo) for correctly base-paired DNA divided by the rate of forward polymerization (0.05/37 = 0.14%). Excision of duplex DNA containing 1-7 mismatches was biphasic, and the rate and amplitude of the fast phase increased with the number of mismatches, reaching a maximum of 9 x s(-1). We showed that transfer of DNA from the polymerase to the exonuclease active site and back again occurs through an intramolecular reaction, allowing for a complete cycle of reactions for error correction. For DNA containing a buried mismatch (T:T followed by C:G base pairs), the 3' base was removed at a rate of 3 x s(-1). The addition of nucleotide to the reaction that is identical to the 3' base increased the rate of excision 7-fold to 21 x s(-1). We propose that the free nucleotide enhances the rate of transfer of the DNA to the exonuclease active site by interrupting the correct 3' base pair through interaction with the template base. The exonuclease contribution to fidelity is minimal if the calculation is based on hydrolysis of a single mismatch: (k(exo) + k(pol,over))/(k(pol,over)) = 10, but this value increases to approximately 200 when examining error correction in the presence of nucleotides.

Insights into the molecular mechanism of mitochondrial toxicity by AIDS drugs

Several of the nucleoside analogs used in the treatment of AIDS exhibit a delayed clinical toxicity limiting their usefulness. The toxicity of nucleoside analogs may be related to their effects on the human mitochondrial DNA polymerase (Pol gamma), the polymerase responsible for mitochondrial DNA replication. Among the AIDS drugs approved by the FDA for clinical use, two are modified cytosine analogs, Zalcitabine (2',3'-dideoxycytidine (ddC)) and Lamivudine (beta-d-(+)-2',3'-dideoxy-3'-thiacytidine ((-)3TC])). (-)3TC is the only analog containing an unnatural l(-) nucleoside configuration and is well tolerated by patients even after long term administration. In cell culture (-)3TC is less toxic than its d(+) isomer, (+)3TC, containing the natural nucleoside configuration, and both are considerably less toxic than ddC. We have investigated the mechanistic basis for the differential toxicity of these three cytosine analogs by comparing the effects of dideoxy-CTP), (+)3TC-triphosphate (TP), and (-)3TC-TP on the polymerase and exonuclease activities of recombinant human Pol gamma. This analysis reveals that Pol gamma incorporates (-)3TC-triphosphate 16-fold less efficiently than the corresponding (+)isomer and 1140-fold less efficiently than dideoxy-CTP, showing a good correlation between incorporation rate and toxicity. The rates of excision of the incorporated analogs from the chain-terminated 3'-end of the DNA primer by the 3'-5'-exonuclease activity of Pol gamma were similar (0.01 s(-)1) for both 3TC analogs. In marked contrast, the rate of exonuclease removal of a ddC chain-terminated DNA occurs at least 2 orders of magnitude slower, suggesting that the failure of the exonuclease to remove ddC may play a major role in its greater toxicity. This study demonstrates that direct analysis of the mitochondrial DNA polymerase structure/function relationships may provide valuable insights leading to the design of less toxic inhibitors.

Human mitochondrial DNA polymerase holoenzyme: reconstitution and characterization

We have reconstituted the holoenzyme of the human mitochondrial DNA polymerase from cloned and overexpressed catalytic and accessory subunits. We have examined the polymerization activity of the catalytic subunit alone and of the holoenzyme to establish the function of the accessory subunit in this two subunit enzyme. The accessory subunit associates with the catalytic subunit with a dissociation constant of 35 +/- 16 nM as measured by the concentration dependence of its effect in stimulating maximal DNA binding and polymerization. At saturating concentrations, the accessory subunit contributes to every kinetic parameter examined to facilitate tighter binding of DNA and nucleotide and faster replication. The accessory protein makes the DNA binding 3.5-fold tighter (K(d) of 9.9 +/- 2.1 nM compared to 39 +/- 10 nM for the catalytic subunit alone) without significantly affecting the DNA dissociation rate (0.02 +/- 0.001 compared to 0.03 +/- 0.001 s(-)(1)). The ground-state nucleotide binding is improved from 4.7 +/- 2.0 to 0.78 +/- 0.065 microM, and the maximum DNA polymerization rate is increased from 8.7 +/- 1.1 to 45 +/- 1 s(-)(1) by the addition of the accessory protein. This leads to an increase in processivity from an estimated 290 +/- 46 to 2250 +/- 162. Although the accessory protein has been described as a "processivity factor" because of its effect on the ratio of rate constants defining processivity, this terminology falls short of adequately describing the profound effects of the small subunit on nucleotide-binding and incorporation catalyzed by the large subunit. By using the complete holoenzyme, we can now proceed with a comprehensive analysis of the structural and mechanistic determinants of enzyme specificity that govern toxicity of nucleoside analogues used in the treatment of viral infections such as AIDS.

Strelkovimermis amphidis n. sp. from chironomid adults emerging from Lake Itasca and Long Lake, Minnesota

Mermithid nematodes, Strelkovimermis amphidis n. sp., emerged from chironomid imagos from Lake Itasca in Minnesota in the fall of 1996, 1997 and from Long Lake in the fall of 1998. The species is distinguished from the other 11 members of the genus by the long cephalic papillae, absence of an excretory pore, pointed termini in both sexes, large amphids, body diameter decrease at the vulva, long vagina, and the absence of lateral genital papillae. Strelkovimermis amphidis n. sp. is the fifth member of this genus recorded from Lake Itasca. The presence of and nature of the bursal sleeve is suggested as a useful distinguishing characteristic. The ratios involving spicule axis length, diameter of the body at the genital pore, and the length of the tail are also discussed in distinguishing species of Strelkovimermis. An expanded key to the species of Strelkovimermis is included.

The structural basis for complement receptor type 2 (CR2, CD21)-mediated alternative pathway activation of complement: studies with CR2 deletion mutants and vaccinia virus complement-control protein-CR2 chimeras

The role of complement receptor 2 (CR2) short consensus repeats (SCR) in binding of hydrolyzed C3 (iC3) to form an alternative pathway (AP) convertase, and promoting C3 fragment deposition following AP activation, was examined. We used (1) K562 cells transfected with CR2 constructs, where the C3d-binding site of CR2 (SCR1+2) was replaced with the four-SCR vaccinia virus complement control protein (VCP), or truncation mutants thereof, and (2) COS cells transfected with wild-type (wt) CR2, or deletion mutants thereof. AP activation required iC3 binding in both systems. Thus, the VCP-CR2 chimera had an iC3 binding efficiency of 11.4 %, compared to wtCR2, and a relative AP activity of 5.5 %, the truncation mutants being inactive. Of the CR2 mutants, only EK (DeltaSCR10 - 11) had AP activity similar to wtCR2. NN (DeltaSCR6 - 8) and NOP (DeltaSCR6-mid14) had reduced AP activity, but near normal iC3 binding. XB (DeltaSCR3 - 6) and PP (DeltaSCR3-mid14) were inactive in both assays. We conclude that, whilst iC3 binding to CR2 via SCR1 - 4 is essential for AP activation, the efficiency of C3 deposition also depends on the midportion of CR2.

Hydromermis contorta (Kohn) and Hydromermis pseudocontorta n. sp. from chironomids of Lake Itasca and Long Lake, Minnesota

Hydromermis contorta (Kohn) and Hydromermis pseudocontorta n. sp. are described from chironomids in Lake Itasca and Long Lake, Minnesota, respectively. The former was recovered from adult females of Glyptotendipes paripes (Edwards) and the latter from fourth-instar larvae of Chironomus sp. Hydromermis pseudocontorta n. sp. resembles H. contorta in cephalic structures, overall size, and the presence of a restricted trophosome in the female. The terminal mouth, long uterine and vulvar limbs of the vagina, and the strongly chitinized brownish spicule of H. contorta contrast with the subventral mouth, short vaginal limbs, and the light yellow spicule of H. pseudocontorta n. sp. Both nematode species emerge from the host as sexually mature adults and both species give evidence of mating while in the host. The H. contorta described by Welch is designated as a new species, Hydromermis albionis n. sp.

Effect of Sulfo Lewis C on smoke inhalation injury in an ovine model

OBJECTIVE

To evaluate the effect of Sulfo Lewis C (SO3-3âGal1-3GlcNAc-O(CH2)8-COOMe), a putative ligand of selectins, on smoke inhalation injury.

DESIGN

Prospective animal study with concurrent controls.

SETTING

An animal laboratory.

SUBJECTS

Twelve 1-yr-old female sheep, weighing 24 to 33 kg.

INTERVENTIONS

Twelve sheep received nine exposure units of smoke generated by thermolysis of pine woodchips (80 g). Group 1 (n = 6) was untreated. Group 2 (n = 6) was treated with an intravenous infusion of Sulfo Lewis C after smoke exposure. Animals were killed 48 hrs after injury.

MEASUREMENTS AND MAIN RESULTS

Cardiopulmonary variables and blood gases were measured serially. Granulocyte free-radical production was measured before smoke exposure and at 4 and 48 hrs after injury. Ventilation/perfusion distribution (VA/Q) was analyzed using the multiple inert gas elimination technique. Granulocyte free-radical production was increased after smoke exposure in both groups. Oxygenation was significantly improved by the administration of Sulfo Lewis C. VA/Q analysis demonstrated significantly less blood flow to low VA/Q lung segments in treated animals.

CONCLUSIONS

Selectin blockade attenuated lung injury after smoke exposure. These data support the hypothesis that neutrophils play a pivotal role in smoke inhalation injury.

Expression, purification, and initial kinetic characterization of the large subunit of the human mitochondrial DNA polymerase

Faulty replication of the human mitochondrial genome is thought to be the cause of many diseases; moreover, the low selectivity of the mitochondrial DNA polymerase has been implicated as the cause of many side effects observed in the treatment of viral infections such as HIV. To better understand how the mitochondrial genome is replicated, we cloned a cDNA encoding the large subunit of human DNA polymerase gamma, the enzyme that replicates the mitochondrial genome. The large subunit was recombinantly expressed and purified to near homogeneity. The purified enzyme demonstrated both polymerase and 3'-5' exonuclease activity. The purified protein was examined in single nucleotide incorporation assays, demonstrating that the enzyme had a maximum polymerization rate of 3.5 s-1 and a dissociation rate from the DNA substrate of 0.03 s-1, affording a calculated processivity of 116. The dissociation constants for the enzyme binding to DNA and nucleoside triphosphate were 39 nM and 14 microM, respectively. The 3'-5' exonuclease rate was measured at 0. 18 s-1. Though the slow rate of polymerization suggests that the large subunit of human DNA polymerase gamma may require accessory factors to increase its processivity of polymerization, the kinetic parameters indicate that the large subunit of DNA polymerase gamma could replicate the mitochondrial genome in a physiologically relevant time frame. This study provides the initial characterization of the large subunit of DNA polymerase gamma and establishes the baseline for examination of the effects of accessory proteins such as the putative small subunit.

Strelkovimermis arkansensis n. sp. and Hydromermis welchi n. sp. from chironomid imagos

Strelkovimermis arkansensis n. sp. and Hydromermis welchi n. sp. are described from chironomid adults in Arkansas and Minnesota, respectively. The host of the former is Glyptotendipes paripes (Edwards) and of the latter Polypedilum (Polypedilum) nubeculosum (Meigen). Strelkovimernis arkansensis n. sp. most closely resembles Strelkovimermis buccalis Johnson and Kleve, 1996 and is separated from that species by color in the living worms, thickness of the cuticle, and length of the cephalic papillae. Hydromermis welchi n. sp. is similar to Hydromermis gastroviridis Johnson and Kleve, 1997 and is separated from that species by color in the living worms, structure of the spicule, and number of genital papillae. A variant of H. welchi n. sp. is described. Molting in S. arkansensis was apparently facilitated by having both postparasitic males and females in the same vial.

The requirement of localized, CR2-mediated, alternative pathway activation of complement for covalent deposition of C3 fragments on normal B cells

We have shown previously that normal B cells share, with Epstein-Barr virus-transformed and malignant B cells, the ability to activate the alternative pathway (AP) of complement in vitro, resulting in the deposition of C3 fragments on the cell surface. Complement receptor type 2 (CR2, CD21) has been implicated directly as the site for formation of an AP convertase, which provides nascent C3b for deposition at secondary sites on the B-cell surface. In the present study, we have examined C3 fragment deposition in vitro in more detail by (1) assessing the importance of locally generated C3b for the deposition process, (2) investigating whether CR2 is the sole requirement for conferring AP activation capacity on a cell, and (3) determining whether CR2's function, as an AP activator, has different structural requirements from ligand binding. Increasing the availability of native C3, by increasing the serum (NHS) concentration, resulted in enhanced C3 fragment deposition on the B cells, whereas use of factor 1-depleted NHS, which showed massive fluid phase C3 conversion during the incubation, diminished the deposition. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting of untreated and hydroxylamine-treated lysates from B cells, after in vitro activation, revealed that the majority of C3 fragments (primarily iC3b and C3dg) had been covalently bound to the cell surface. Transfection of COS cells with wild-type CR2 or a deletion mutant lacking 11 of the molecule's 15 homologous domains, but retaining the ligand-binding site, revealed that expression of intact CR2 conferred a 12-fold increase in AP-activating capacity on these cells, while no increase in AP activity was apparent on cells transfected with the mutant CR2.

A comparative study of normal B cells and the EBV-positive Burkitt's lymphoma cell line, Raji, as activators of the complement system

Contradictory reports regarding the ability of complement receptor type 2 (CR2,CD21) on normal B cells to activate complement (C') via the alternative pathway (AP), prompted us to compare the performance of human peripheral blood B cells and the Epstein-Barr virus-positive Burkitt's lymphoma cell line, Raji (a well characterized AP activator) by using flow cytometry. Measured in terms of the membrane deposition of C3 fragments per cell, Raji cells were significantly (6- to 26-fold) more effective as complement activators than were normal B cells. Raji cells were also found to express approximately four to five times as many CR2 as normal B cells. In addition, they distinguished themselves by displaying a greater Ca(2+)-dependent activation, with pooled normal human sera (NHS) as the complement source, and by degrading unprotected C3b fragments from iC3b to C3dg/C3d at a significantly lower rate than the B cells. The Ca2+ dependency of Raji cell activation was found to be partially a result of classical pathway (CP) triggering by specific antibodies in the NHS, although other triggering mechanisms may also be involved. If the influence of these variations between Raji cells and normal B cells was excluded, by relating deposition of anti-C3d-reactive fragments, during AP activation, to the number of CR2 expressed, the difference in performance between the two cell types was found to be insignificant.

Two new species of imagocidal Hydromermis (Nematoda: Mermithidae) from Endochironomus subtendens (Townes) (Diptera: Chironomidae)

Hydromermis viridis n. sp. and Hydromermis gastroviridis n. sp. are described from June and August emerging imagos, respectively, of Endochironomus subtendens (Townes) in Lake Itasca, Clearwater County, Minnesota. The position of the mouth, shape of the posterior end, structure and size of the spicule, absence of an excretory pore, arrangement of male tail musculature, and measurements separate the new species form other species of Hydromermis as well as from one another. The 2 species are placed in the genus Hydromermis though having a rounded tail and only 6 hypodermal cords at midbody. An anomalous double vagina condition is reported in H. viridis.

Strelkovimermis acuticauda n. sp. and Strelkovimermis buccalis n. sp. (Nematoda:Mermithidae) from adult chironomids (Diptera:Chironomidae) from Lake Itasca, Minnesota

Specimens of 2 mermithid species were obtained from adults of undetermined species of chironomids emerging from Lake Itasca (Clearwater County), Minnesota. Both species have the characteristics of species in the genus Strelkovimermis. The new species are distinguishable from one another and from the 8 currently accepted species in the genus by their small size, shape of the posterior end, length of the buccal funnel, length of the cephalic papillae, location of the mouth, and morphology of the spicule region and vagina. Strelkovimrmis acuticauda n. sp. is unique in possessing an acute posterior end, an auxiliary protractor muscle, and a relatively long vagina, whereas Strelkovimermis buccalis n. sp. is distinguishable from other Strelkovimermis species by its thick cuticle and exceptionally long buccal funnel. The significance of the tail muscles is emphasized as a taxonomic feature to be used in describing future species of Strelkovimermis. A key to the 10 species of Strelkovimermis is provided.

Nitrate analysis in biological fluids by gas chromatography-nitrogen-phosphorous detection

Nitrate analysis in body fluids is an important part of the study of nitric oxide metabolism. A sensitive, simple procedure for nitrate analysis was developed by producing nitrobenzene from the nitrate in the samples and benzene. The nitrobenzene produced was measured on a gas chromatograph (GC) equipped with a nitrogen-phosphorous detector. Cl-, which interfered with the derivitization procedure, was removed as silver chloride after precipitation with silver lactate. Rat urine samples were also analyzed after elution through a C18 reverse-phase sample preparation column to remove organic molecules that competed with benzene for the nitrate in the sample. A benzene derivative, 2-nitro-1,3-dimethylbenzene (2-nitro-m-xylene), was chosen as an internal standard for GC analysis. Recovery of nitrate was 67 +/- 2% in serum and 87 +/- 8% in urine. Sensitivity of the procedure was 1 microM. This procedure offers improvements in sensitivity, simplicity, and consistency over previously published procedures and makes possible the measurement of nitrate and determination of isotopic ratios by GC-MS on the same sample.

The effect of inhaled nitric oxide on pulmonary ventilation-perfusion matching following smoke inhalation injury

BACKGROUND

We previously reported that inhaled nitric oxide (NO) improved pulmonary function following smoke inhalation. This study evaluates the physiologic mechanism by which inhaled NO improves pulmonary function in an ovine model.

METHODS

Forty-eight hours following wood smoke exposure to produce a moderate inhalation injury, 12 animals were anesthetized and mechanically ventilated (FIO2, 0.40; tidal volume, 15 mL/kg; PEEP, 5 cm H2O) for 3 hours. For the first and third hours, each animal was ventilated without NO: for the second hour, all animals were ventilated with 40 ppm NO. Cardiopulmonary variables and blood gases were measured every 30 minutes. The multiple inert gas elimination technique (MIGET) was performed during the latter 30 minutes of each hour. The data were analyzed by ANOVA.

RESULTS

Pulmonary arterial hypertension and hypoxemia following smoke inhalation were significantly attenuated by inhaled NO compared with the values without NO (p < 0.05, ANOVA). Smoke inhalation resulted in a significant increase in blood flow distribution to low VA/Q areas (VA/Q < 0.10) with increased VA/Q dispersion. These changes were only partially attenuated by the use of inhaled NO. The SF6 (sulfur hexafluoride) retention ratio was also decreased by inhaled NO. Peak inspiratory pressures and pulmonary resistance values were not affected by inhaled NO.

CONCLUSIONS

Inhaled NO moderately improved VA/Q mismatching following smoke inhalation by causing selective pulmonary vasodilation of ventilated areas in the absence of bronchodilation. This modest effect appears to be limited by the severe inflammatory changes that occur as a consequence of smoke exposure.

The pulmonary effect of nitric oxide synthase inhibition following endotoxemia in a swine model

OBJECTIVE

To evaluate the pulmonary effect of treatment with N-nitro-L-arginine methyl ester (NAME) with and without inhaled nitric oxide (NO) in a swine model of endotoxemia.

DESIGN

Randomized controlled trial.

SETTING

Laboratory.

INTERVENTIONS

Following a 20-minute intravenous infusion of Escherichia coli lipopolysaccharide (LPS) (200 micrograms/kg), animals were resuscitated with saline solution (1 mL/kg per minute) and observed for 3 hours while mechanically ventilated (fraction of inspired oxygen [FIO2], 0.6; tidal volume, 12 mL/kg; positive end-expiratory pressure, 5 cm H2O). Group 1 (LPS, n = 6) received no additional treatment; group 2 (NAME, n = 5) received NAME (3 mg/kg per hour) for the last 2 hours; group 3 (NO, n = 6) received NAME (3 mg/kg per hour) and inhaled NO (40 ppm) for the last 2 hours; and group 4 (control, n = 5) received only saline solution without LPS.

MAIN OUTCOME MEASURES

Cardiopulmonary variables and blood gases were measured serially. The multiple inert gas elimination technique was performed at 3 hours. The wet-to-dry lung weight ratio was measured following necropsy.

RESULTS

Administration of LPS resulted in pulmonary arterial hypertension, pulmonary edema, and hypoxemia with increased ventilation perfusion ratio mismatching. None of these changes were attenuated by NAME treatment alone but all were significantly improved by the simultaneous administration of inhaled NO.

CONCLUSIONS

Systemic NO synthase inhibition failed to restore hypoxic pulmonary vasoconstriction following LPS administration. The deleterious effects of endotoxemia on pulmonary function can be improved by inhaled NO but not by systemic inhibition of NO synthase.

The effect of inhaled nitric oxide on smoke inhalation injury in an ovine model

Smoke inhalation is a significant comorbid factor in thermal trauma. The effect of inhaled nitric oxide (NO) on smoke inhalation injury was evaluated in an ovine model. Following smoke exposure, group 1 animals (n = 9) spontaneously breathed room air, and group 2 animals (n = 8) breathed 20 parts per million of NO in air for 48 hours. Cardiopulmonary variables and blood gases were serially measured; bronchoalveolar lavage (BAL) was performed and wet-to-dry lung weight ratios (W/D) determined at 48 hours. Pulmonary vasoconstriction following smoke inhalation was significantly attenuated by inhaled NO (p < 0.05), which exerted no apparent effect on the systemic circulation. In group 2, the serial decline in pulmonary oxygenation was less than in group 1, consistent with a smaller physiologic shunt (p < 0.05). There were no significant differences in W/D, lung compliance, BAL fluid analysis results, or histologic evaluation findings between the two groups. These results suggest that inhaled NO exerted beneficial effects on pulmonary arterial hypertension and oxygenation following smoke inhalation without apparent amelioration of airway inflammation.

Effect of inhaled nitric oxide on pulmonary function after sepsis in a swine model

BACKGROUND

Inhaled nitric oxide (NO) has been shown to improve sepsis induced pulmonary dysfunction. This study evaluated the mechanism by which inhaled NO improves pulmonary function in a porcine sepsis model.

METHODS

After an infusion of Escherichia coli lipopolysaccharide (LPS, 200 micrograms/kg), animals were resuscitated with saline solution (1 ml/kg/min) and observed for 3 hours while mechanically ventilated (fraction of inspired oxygen, 0.6; tidal volume, 12 ml/kg; positive end-expiratory pressure, 5 cm H2O). Group 1 (LPS, n = 6) received no additional treatment. Group 2 (NO, n = 6) received inhaled NO (40 ppm) for the last 2 hours. Group 3 (control, n = 5) received only saline solution without LPS. Cardiopulmonary variables and blood gases were measured serially. Multiple inert gas elimination technique was performed at 3 hours. Wet to dry lung weight ratio was measured after necropsy.

RESULTS

Lipopolysaccharide resulted in pulmonary arterial hypertension, pulmonary edema, and hypoxemia. Multiple inert gas elimination technique analysis indicated a significant increase in blood flow to true shunt and high ventilation perfusion distribution (VA/Q) areas with an increased dispersion of VA/Q distribution. All of these changes were significantly attenuated by NO.

CONCLUSIONS

Inhaled NO significantly improved LPS induced VA/Q mismatching by decreasing both true shunt and high VA/Q areas, by decreasing pulmonary edema, and by redistributing blood flow from true shunt to ventilated areas.

Pica in an urban environment

The practice of pica, the compulsive ingestion of nonfood substances over a sustained period of time, was studied in 553 African American women who were admitted to prenatal clinics in Washington, D.C. Dietary, biochemical, and psychosocial correlates of the pica practices of a subset of this urban population are presented in this paper. Geophagia, compulsive eating of clay or dirt, was not observed in these women; pagophagia, or the ingestion of large quantities of ice and freezer frost, was self reported in 8.1% of the women, who consumed 1/2 to 2 cups a day from 1 to 7 days per week. Serum ferritin concentrations of pica women were significantly lower during the second and third trimesters of pregnancy; the average values for three trimesters of pregnancy for both ferritin and mean corpuscular hemoglobin were significantly lower in pica women than their nonpica counterparts (P = 0.0001 and P = 0.017, respectively). Although not significantly different, the iron (66 vs. 84% RDA) and calcium (60 vs. 75% RDA) contents of the diets of pica women were less those of nonpica women. Gestational age, body length, and body weight were not different, but head circumferences of infants delivered to pica women who consumed freezer frost and/or ice were smaller than those of nonpica women (P = 0.012). The hypothesis is presented that pica in African American women may be a mediator of stress, acting through the immune system. The size of the social support network of pica women was significantly less than that of nonpica women.(ABSTRACT TRUNCATED AT 250 WORDS)

Relationships of serum illicit drug concentrations during pregnancy to maternal nutritional status

Findings reported are for a subset of African American subjects, residing in the urban area of Washington, D. C., who participated in a Program Project designed to study nutrition, other factors, and the outcome of pregnancy. Fasting blood samples, drawn during each trimester of pregnancy and at delivery, were screened for concentrations of cocaine, phencyclidine (PCP) and marijuana. Since substance abusers are expected to consume inadequate diets, these samples were also analyzed for serum folate, vitamin B12, ferritin and ascorbic acid. Data for these biochemical variables were compared for subjects whose serum values for drugs were either above or below the drug screening threshold concentrations established by ADAMHA/NIDA. Pearson's correlations were used to determine relationships between pregnancy outcome variables and maternal serum drug concentrations. Blood samples drawn at delivery showed higher maternal: cord ratios (mean +/- SEM) for marijuana (3.3 +/- 2.2) and PCP (2.9 +/- 1.0) than for cocaine (1.0 +/- 0.2). The subjects whose serum values were above the ADAMHA/NIDA ranges for marijuana, PCP and cocaine had concentrations of folate and ferritin that were significantly less than those of subjects with lower serum drug levels (P < or = 0.05). High maternal serum concentrations of illicit drugs were accompanied by a significant increase in leukocyte count (P < or = 0.05). The level of maternal cocaine during the third trimester was inversely correlated with birthweight (r = -0.29; n = 52; P = 0.038) and head circumference (r = -0.28; n = 52; P = 0.047).(ABSTRACT TRUNCATED AT 250 WORDS)

Prenatal predictors of performance on the Brazelton Neonatal Behavioral Assessment Scale

The present study presents a prospective analysis of the interrelationships among prenatal medical, nutritional (dietary and biochemical) and behavioral determinants of Brazelton performance. Previous researchers (Scanlon 1984, Lester and Brazelton 1984) have raised questions regarding the relative roles of medical factors, nutrition, ponderal index and other behavioral factors in neonatal performance on the BNBAS. Four hundred sixty-seven predominantly Black nulliparous women and their neonates in Washington, D.C. who were enrolled in the study by the 20th week of gestation were subjects. Results of univariate tests of significant (P < 0.01) association between independent variables and Brazelton clusters from scores measured on day 2 are presented. The 26 behavioral items were summarized into 6 clusters as done in similar studies by linearizing measures made on a curvilinear scale and taking the mean. The 6 behavioral clusters are habituation, motor, orientation, range of states, regulation of states, and autonomic. Results of 16 reflex tests are used to define a seventh reflex cluster. Independent variables included demographic, lifestyle, nutritional, medical, ponderal index, and psychosocial measures. Several psychosocial variables, including stress, anxiety and partner interaction were associated with the behavioral clusters. Nutritional variables were associated with BNBAS habituation, motor, orientation, reflex score and autonomic responses. An analysis of co-variance was performed to determine the joint effect of the above variables on the variation in the Brazelton performance on the seven cluster scores. Five of the seven models (orientation, motor, range of states, autonomic, and reflex scores) were significant predictors of the outcome variables.

Multiple factors as mediators of the reduced incidence of low birth weight in an urban clinic population

A five year prospective observational study was initiated in 1985 at Howard University to describe the nutritional, clinical, dietary, lifestyle, environmental, and socioeconomic characteristics of women who enrolled in the hospital prenatal clinic. The participants were nulliparous, between the ages of 18 and 35 years, free of diabetes and abnormal hemoglobins (sickle cell disease, thalassemia, and hemoglobin C), and had been admitted prior to the 29th week of gestation. During the three year period from 1985-1988, the incidence of low birth weight (LBW) in 239 deliveries to project participants was 8.3%, whereas that of women simultaneously enrolled in the prenatal clinic with the same eligibility requirements, but not recruited for the research project, was 21.9% (P = 0.001). The incidence of LBW in infants of African American women with these eligibility requirements who were delivered by private physicians but were not enrolled in the project, was 6.3%. The reduction in LBW of infants delivered to participants in this study is attributed to the enhanced social and psychological support by project staff during their pregnancies. The caring, sensitive demeanor of the research project staff may have empowered the participants to (a) give greater compliance (91 vs. 70%) in the ingestion of the routine physician-prescribed vitamin/mineral supplement, which provided nutrients low (less than 70% of the 1989 RDAs) in their customary diets, such as folate, pyridoxine, iron, zinc, and magnesium and (b) show greater accountability in keeping prenatal clinic appointments.(ABSTRACT TRUNCATED AT 250 WORDS)

Nutrition, genital tract infection, hematologic values, and premature rupture of membranes among African American Women

Using a prospective comparative design, African American gravidae with and without genital tract infection were assessed with respect to dietary intakes, serum nutrient values, hematologic values, and pregnancy outcomes. Intakes of ascorbic acid, vitamin A, protein, and iron were the dietary variables while levels of ascorbic acid, protein, albumin, globulin, and ferritin were the variables measured in serum. The hematologic variables included hemoglobin, hematocrit, and red and white blood cell counts. Pregnancy outcome was defined on the basis of premature rupture of the membranes (PROM), and infant birth weight, birth length, gestational age, and head circumference. The sample consisted of 335 nulliparous women who were between 16-35 years of age, 96 of whom had genital tract infection based on laboratory reports. Findings indicated no significant differences between the mean dietary intakes as well as serum values of the infected and non-infected women, and no difference in the incidence of PROM. However, non-infected women had a better mean hematologic profile than the infected gravidae during pregnancy. Also, for the non-infected group, there were significant relationships between head circumference and protein consumption (P = .015) and serum ferritin (P = .05). For the infected women, the relationship between the hemoglobin and hematocrit measurements obtained at the first prenatal visit and infant birth weight, birth length and head circumference were statistically significant.

Maternal stress and pregnancy outcomes in a prenatal clinic population

A two-fold decrease in the incidence of infant low birth weight, from 20.6% to 8.3%, occurred in Africa American women enrolled from 1985 to 1988 in this interdisciplinary research project conducted in an urban prenatal clinic. Nutritional, biochemical, medical, psychosocial, lifestyle, and environmental data were collected by trained Africa American interviewers. Several instruments were administered to the mother to specify the stress construct and assess body image, the social support network, and other psychosocial variables. The reduction in the incidence of low birth weight in an urban Africa American low income population admitted to the Howard University Hospital is attributed to the mediation of maternal stress by project personnel, in effect, providing an additional support system through the caring, sensitive environment provided by the project clinical staff, who met the women at each of their clinic-scheduled appointments. Women with a positive self attitude and higher self esteem were more likely to be delivered infants at term; the number of persons in the mother's social support network was directly correlated with her infant's gestational age. Maternal serum concentrations of the antioxidant vitamins, vitamin E and ascorbic acid, and the free radical scavenger, uric acid, were significantly correlated with serum folate and blood urea nitrogen. An hypothesis of low birth weight is presented.

Demographic profile, methodology, and biochemical correlates during the course of pregnancy

This five-year prospective, observational study of urban women during their pregnancies was initiated in 1985 with the recruitment of women between the ages of 18 and 35 years in the prenatal clinics of Howard University Hospital and the District of Columbia Department of Human Services. The objective of the investigation was to characterize African American women by nutritional, biochemical, medical, sociocultural, psychological, lifestyle, and environmental parameters which could be used to formulate interventions to improve pregnancy outcomes. The women were all nulliparous, free of diabetes and abnormal hemoglobins, such as sickle cell disease, and no more than 28 weeks pregnant. During the early course of the study, it was apparent that 96% of the low income clinic patients had delivered infants of normal birth weight (> or = 2500 g), P = 0.001. Recruitment was then initiated at the District of Columbia General Hospital; women 16 and 17 years of age and at any gestational stage were included. This paper is the first in the series on African American women and their pregnancies. It will present the demographic characteristics of this regular cohort of 443 women who delivered live infants, the methodology used for biochemical, dietary, and psychosocial data sets, the mean values for infant gestational age, head circumference, body length, and birth weight from singleton births, and correlates of the mean values of biochemical variables for three trimesters of pregnancy with other biochemical parameters and those pregnancy outcomes.

Dietary intakes, anthropometric measurements and pregnancy outcomes

The relationships of maternal prenatal dietary intakes and anthropometric measurements to pregnancy outcomes were investigated in a prospective observational study of urban African American women. The 322 subjects, a subset of the 744 women recruited for the study using purposive sampling, were all nulliparous, free of diabetes mellitus and abnormal hemoglobins, and delivered term, singleton infants. Sociodemographic data and monthly quantitative 24-hour food recalls were collected by trained interviewers. Maternal anthropometric measurements were obtained from the subjects' hospital records. Pregnancy outcome data were obtained by physical examinations of the newborn infants by the project pediatrician. With the exception of vitamin C, average maternal dietary intakes were within the ranges of intakes obtained in previous studies. Mean intakes of protein, vitamins A and C, thiamin, riboflavin, and niacin exceeded the 1989 RDA, while those of food energy, vitamin B-6, folate, calcium, iron, magnesium, and zinc were below the RDA. Underweight prior to pregnancy and low pregnancy weight gains were found among 12.9% and 44.4% of the subjects respectively. Dietary intakes were not significantly correlated with pregnancy outcomes. Maternal anthropometric measurements significantly correlated with pregnancy outcomes included delivery weight, pregnancy weight gain, weekly weight gain, prepregnancy weight, net weight gain, height, prepregnancy body mass index, and % ideal prepregnancy body weight (P < 0.05). Using the stepwise selection procedure in multiple regression analysis, delivery weight, % ideal prepregnancy body weight, and prepregnancy body mass index were selected as being predictive of infant birth weight. It was concluded that anthropometric measurements were better nutritional predictors of pregnancy outcome than dietary intake.

Biochemical profile of African American women during three trimesters of pregnancy and at delivery

The data presented are the results from a prospective observational study which was conducted to investigate the effects of nutrition and other related factors on the outcome of pregnancy in nulliparous African American women 16-35 years old. Fasting blood samples were collected from the women during the first, second and third trimesters of pregnancy. At delivery, both maternal and cord samples were collected. Biochemical variables such as, serum folate, vitamin B12, ascorbic acid, vitamin E, ferritin, selected minerals as well as complete blood count (CBC) and red cell folate were analyzed in the blood samples. The concentrations of hematocrit, hemoglobin, white blood cells, red blood cells and vitamin B12 were below the reference non-pregnant ranges throughout gestation. Maternal concentrations of folate and vitamin E increased sequentially with increased gestational age. Serum ferritin, during the third trimester, declined to 58% of the first trimester concentration. Maternal levels of ferritin at delivery were one third of the values found in the infant (cord) sample. Cord levels of folate, ascorbic acid and vitamin B12 were higher than the concentrations in the maternal delivery samples. The data suggest that among this group of pregnant women, major physiological changes, such as plasma volume expansion which alters blood chemistry and maternal to fetal transfer of nutrients, were similar to the findings of other investigators. In this population however, the findings for serum and whole blood folate are contrary to those reported by other researchers, and the sequential increase in the maternal concentration of the vitamin during pregnancy could be attributed to the use of vitamin supplements.

Selected lifestyle practices in urban African American women--relationships to pregnancy outcome, dietary intakes and anthropometric measurements

The relationships of selected lifestyle factors (cigarette smoking, consumption of alcoholic beverages, recreational drug use, and exercise during pregnancy), all self-reported, to pregnancy outcomes, dietary intake during pregnancy, and maternal anthropometric measurements, were investigated in a group of urban African American pregnant women. The 234 subjects were aged 16-35 years and were free of diabetes and abnormal hemoglobins. The lifestyle data were collected by trained interviewers during the subjects' prenatal clinic visits, and the dietary data by monthly, quantitative 24-hour food recalls conducted during these same visits. Maternal anthropometric measurements were obtained from the subjects' hospital records, and pregnancy outcome data during physical examinations of the newborn infants. Both cigarette smoking and drug use were associated with significantly lower mean birth weight, length, and head circumference, while exercise was associated with a significantly higher mean birth weight, and head circumference (P < 0.05). Drug use during pregnancy was associated with a significantly higher intake of vitamin C, and a significantly lower intake of iron; while women reporting drug use before pregnancy had significantly higher mean intakes of food energy, protein, total and saturated fat, and zinc. Prepregnancy weight, percent ideal prepregnancy body weight, prepregnancy body mass index, and delivery weight were significantly lower among those reporting drug use before pregnancy. Multiple regression analyses indicated that smoking explained a relatively small proportion of the variance in infant birth weight compared with delivery weight and percent of ideal prepregnancy body weight.

Maternal low level lead and pregnancy outcomes

We examined the relationship between the concentrations of blood lead and pregnancy outcomes in a subset of 349 African American women who enrolled in the program project, "Nutrition, Other Factors, and the Outcome of Pregnancy." Vitamin-mineral supplement users had significantly higher serum levels of ascorbic acid and vitamin E. Also, in supplement users, there were significantly lower mean concentrations of maternal blood lead. Inverse correlations were found between maternal levels of lead and the antioxidant vitamins, vitamin E and ascorbic acid. In addition, significant Pearson's correlations were observed between maternal blood lead levels and the following variables: positive correlations with calcium, phosphorus, mean corpuscular volume; inverse correlations with gestational age, Ponderal Index, infant orientation, and hematologic values. In the total subset, the three trimester sample means for maternal blood lead concentrations were not significantly different for mothers of infants who weighed less than 2500 g (low birth weight) and those who were delivered infants who weighed 2500 g or more. Clinically, nutrition may play a role in the reduction of potentially adverse effects from lead during pregnancy, i.e. protection of the fetus against lead toxicity and/or free radical damage through the antioxidant actions of vitamin E and ascorbic acid. Even when maternal blood lead levels are within the so-called "safe" range, maternal/use of a vitamin supplement supplying vitamin E and ascorbic acid during pregnancy may offer protection.

Deoxyribonucleic acid, ribonucleic acid, and protein in the placentas of normal and selected complicated pregnancies

Placenta from uncomplicated term pregnancies resulting in the birth of male infants weighing between 2900 and 3800 grams were analyzed for deoxyribonucleic acid (DNA), ribonucleic acid (RNA), and protein content. The mothers of the infants all had pre-pregnancy weights within +/- 15 percent expected body weight for body frame, according to the Metropolitan Life Tables. There were no significant differences, as regards the content of DNA, RNA and protein, between the placental cotyledons. Nine placenta from mothers giving birth to growth retarded infants were analyzed along with the placenta from six mothers with insulin dependent diabetes mellitus. A trend suggesting less DNA in the placenta of the severely growth retarded (symmetric) infants when compared with placenta from the normal pregnancies was not noted in the less severely growth retarded (asymmetric) infants. The placenta from the infants of diabetic pregnancies contained DNA and RNA in amounts similar to that found in normal pregnancy placenta but the protein content was greater.

Prenatal substance abuse and pregnancy outcomes among African American women

Subjects in this prospective observational study were 467 nulliparous women, ages 16-35, recruited at the prenatal clinics of a university hospital and a public hospital. Using a purposive sampling approach, and entry questionnaire and a series of psychosocial instruments were administered throughout the pregnancy course to assess stress, anxiety, body image, self-esteem, pregnancy symptoms, locus of control, and partner's interaction. Several pregnancy outcome measures were determined after delivery. Brazelton neonatal behavioral assessments were performed two days after birth of infants delivered to the maternal subjects. Self-reported substance abuse data were obtained from the entry questionnaire and the medical intake records, with usage characterized in terms of occurrence prior to and/or during pregnancy. Illicit drug users during pregnancy had lower self-esteem, greater stress, more pregnancy symptoms, a more negative pre-pregnancy body image and less favorable interactions with their partners. T test results show that infants of smokers had smaller head circumferences, shorter body length, and less optimal Brazelton orientation performance. Infants of illicit drug users had smaller head circumferences and shorter body lengths.

The effects of pentoxifylline on pulmonary function following smoke inhalation

Bronchopulmonary injury secondary to smoke inhalation is a significant comorbid factor following major thermal trauma. The present study evaluates the effects of pentoxifylline (PTX) on pulmonary function in an ovine model of inhalation injury. Following smoke exposure to produce a moderate inhalation injury, 16 animals were divided into two groups. Group 1 animals (n = 8) were untreated; Group 2 animals (n = 8) were treated continuously with pentoxifylline following smoke exposure. The animals were observed in the unintubated, awake state for 48 hr. Cardiopulmonary variables and blood gases were measured serially. Ventilation perfusion distribution (VA/Q), analyzed using the multiple inert gas elimination technique, and bronchoalveolar lavage (BAL) were performed at 48 hr. The wet to dry lung weight ratio was measured following necropsy. In Group 2, the progressive hypoxemia observed following smoke inhalation was attenuated with less VA/Q mismatching than in Group 1 (P < 0.05). Pulmonary hypertension secondary to increased vascular resistance was also attenuated in Group 2 (P < 0.05). In BAL fluid, polymorphonuclear leukocytes, total protein content, and conjugated dienes were less in Group 2 than in Group 1 (P < 0.05). Plasma-conjugated diene levels were also lower in Group 2 at 48 hr. Extravascular lung water and decrease in lung compliance were greater in Group 1. There was less morphologic evidence of airway injury in Group 2 compared to Group 1. The improvement of pulmonary function following treatment with PTX suggests that this agent may be useful in the management of smoke inhalation injury.

Simultaneous determination of lactulose and mannitol in urine of burn patients by gas-liquid chromatography

Ratios of lactulose/mannitol excretion in urine have been used to assess the extent of intestinal permeability in various disease and trauma conditions. Reported studies have used this technique to correlate altered gastrointestinal mucosal permeability to translocation of bacteria and endotoxin, leading to occult sepsis in burn patients. Enzymatic methods of analysis for urine concentrations of mannitol and lactulose were used in these studies. We have found that urine from patients with severe burns frequently contains compounds that interfere with the enzymatic methods. We describe using gas-liquid chromatography to determine mannitol and lactulose simultaneously in the urine of burn patients. To avoid the multiple peaks for the anomeric forms of the reducing sugars during precolumn trimethylsilyl derivatization, we converted the sugars to oximes before the silylation step. The method gave good recoveries of mannitol and lactulose added to burn patients' urine samples. Unlike the enzymatic methods, gas-liquid chromatography eliminates the effect of interfering compounds and allows for the simultaneous determination of both sugars in urine samples.

Simultaneous Determination of Lactulose and Mannitol in Urine of Burn Patients by Gas-Liquid Chromatography

Ratios of lactulose/mannitol excretion in urine have been used to assess the extent of intestinal permeability in various disease and trauma conditions. Reported studies have used this technique to correlate altered gastrointestinal mucosal permeability to translocation of bacteria and endotoxin, leading to occult sepsis in burn patients. Enzymatic methods of analysis for urine concentrations of mannitol and lactulose were used in these studies. We have found that urine from patients with severe burns frequently contains compounds that interfere with the enzymatic methods. We describe using gas-liquid chromatography to determine mannitol and lactulose simultaneously in the urine of burn patients. To avoid the multiple peaks for the anomeric forms of the reducing sugars during precolumn trimethylsilyl derivatization, we converted the sugars to oximes before the silylation step. The method gave good recoveries of mannitol and lactulose added to burn patients' urine samples. Unlike the enzymatic methods, gas-liquid chromatography eliminates the effect of interfering compounds and allows for the simultaneous determination of both sugars in urine samples.

An epidemic of Oroya fever in the Peruvian Andes

Between February and October 1987, a febrile illness killed 14 persons and seriously affected at least 14 others in Shumpillan, a remote Peruvian mountain village of 353 people. The illness was characterized by fever, headache, chills, and pallor. The fatality rate of untreated cases was 88%. The patients, 71% of whom were male, were 1-75 years of age. Fatal illnesses progressed from lethargy to coma to death in 3-60 days. Patients treated empirically with chloramphenicol survived. Bartonella bacilliformis was isolated from the whole blood of 3 patients. A serologic study revealed a high prevalence of antibodies to B. bacilliformis in the villagers. It is concluded that the villagers suffered from an epidemic of Oroya fever.