The Higher Fullerenes: Isolation and Characterization of C76, C84, C90, C94, and C70O, an Oxide of D5h-C70

The toluene extract of the fluffy carbon material produced by resistive heating of graphite contains a variety of molecules larger than C(60) and C(70) in a total amount of 3 to 4% by weight. Repeated chromatography of this material on neutral alumina has led to the isolation of stable solid samples of C(76), C(84), C(90), and C(94). The characterization, which includes mass spectrometry, (13)C nuclear magnetic resonance, electronic absorption (ultraviolet/visible) and vibrational (infrared) spectroscopy identifies these all-carbon molecules as higher fullerenes. In addition, C(70)O, a stable oxide, has been isolated that is structurally and electronically closely related to D5h-C(70). This compound forms during the resistive heating process and probably has an oxygen atom inserted between two carbon atoms on the convex external surface of the C(70) skeleton.

Oxaliplatin, tetraplatin, cisplatin, and carboplatin: spectrum of activity in drug-resistant cell lines and in the cell lines of the National Cancer Institute's Anticancer Drug Screen panel

The present study was designed to explore the activity of platinum compounds in cisplatin-resistant cell lines, the unselected cell lines of the National Cancer Institute's Anticancer Drug Screen, and the potential for use in combination. The activities of four platinum compounds in cisplatin-resistant KB and A2780 cells were investigated. The cells were highly resistant to cisplatin and cross-resistant to carboplatin, but less than one-tenth as resistant to oxaliplatin and tetraplatin. Cellular accumulation of all platinum compounds was decreased in both resistant cell lines. When the activities of cisplatin and oxaliplatin were evaluated in the National Cancer Institute's Anticancer Drug Screen, marked differences were observed. Evaluation of the activity profile using the COMPARE program revealed a different pattern for both agents: the cisplatin activity profile was similar to those of other diamine-platinum compounds, alkylating agents including melphalan, and camptothecin analogs, whereas the activity profile of oxaliplatin resembled those of other "dach" (diaminocyclohexane) platinum compounds and of acridine derivatives. The sensitivity profiles are influenced by the target(s)/mechanism(s) of action and the mechanism(s) of resistance of a drug. The dissimilarity in profiles suggests that these two platinum compounds have a different target(s)/mechanism(s) of action, a different mechanism(s) of resistance, or most likely both. Studies evaluating combinations of cisplatin/oxaliplatin suggest that the activities of these two agents are at least additive and possibly synergistic. Oxaliplatin has a different spectrum of activity and low cross-resistance to cisplatin and should be valuable in cisplatin refractory patients or in combination with cisplatin.

Targeted inhibition of galectin-1 gene expression in tumor cells results in heightened T cell-mediated rejection; A potential mechanism of tumor-immune privilege

Despite the existence of tumor-specific immune cells, most tumors have devised strategies to avoid immune attack. We demonstrate here that galectin-1 (Gal-1), a negative regulator of T cell activation and survival, plays a pivotal role in promoting escape from T cell-dependent immunity, thus conferring immune privilege to tumor cells. Blockade of immunosuppressive Gal-1 in vivo promotes tumor rejection and stimulates the generation of a tumor-specific T cell-mediated response in syngeneic mice, which are then able to resist subsequent challenge with wild-type Gal-1-sufficient tumors. Our data indicate that Gal-1 signaling in activated T cells constitutes an important mechanism of tumor-immune escape and that blockade of this inhibitory signal can allow for and potentiate effective immune responses against tumor cells, with profound implications for cancer immunotherapy.

Epidemiologic studies on Dengue in Santiago de Cuba, 1997

A small, isolated outbreak of dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) due to dengue virus type 2 (DEN-2) was documented in Santiago de Cuba on the island of Cuba beginning in January 1997. There were 205 DHF/DSS cases, all in persons older than age 15 years. All but three had evidence of a prior dengue infection, with the only known opportunity being the islandwide dengue virus type 1 (DEN-1) epidemic of 1977-1979. Virtually complete clinical and laboratory surveillance of overt disease was achieved. From December 1997 to January 1998, a random, age-stratified serum sample was obtained from 1,151 persons in 40 residential clusters in Santiago. Sera were tested for DEN-1 and DEN-2 neutralizing antibodies. The prevalence of DEN-2 antibodies in children age 15 years and under, born after the 1981 DEN-2 epidemic, was taken as the 1997 DEN-2 infection rate. This was adjusted slightly to accommodate observed cases, resulting in an estimated infection rate of 4.3%. Dengue fever and DHF/DSS attack rates were calculated from estimated total primary and secondary DEN-2 infections. Only 3% of 13,116 primary infections were overt. The DHF/DSS attack rate for adults of all ages was 420 per 10,000 secondary DEN-2 infections.

Mechanism of syncope in patients with bundle branch block and negative electrophysiological test

BACKGROUND

In patients with syncope and bundle branch block (BBB), syncope is suspected to be attributable to a paroxysmal atrioventricular (AV) block, but little is known of its mechanism when electrophysiological study is negative.

METHODS AND RESULTS

We applied an implantable loop recorder in 52 patients with BBB and negative conventional workup. During a follow-up of 3 to 15 months, syncope recurred in 22 patients (42%), the event being documented in 19 patients after a median of 48 days. The most frequent finding, recorded in 17 patients, was one or more prolonged asystolic pause mainly attributable to AV block; the remaining 2 patients had normal sinus rhythm or sinus tachycardia. The onset of the bradycardic episodes was always sudden but was sometimes preceded by ventricular premature beats. The median duration of the arrhythmic event was 47 seconds. An additional 3 patients developed nonsyncopal persistent III-degree AV block, and 2 patients had presyncope attributable to AV block with asystole. No patients suffered injury attributable to syncopal relapse.

CONCLUSIONS

In patients with BBB and negative electrophysiological study, most syncopal recurrences have a homogeneous mechanism that is characterized by prolonged asystolic pauses, mainly attributable to sudden-onset paroxysmal AV block.

Generation of a drug resistance profile by quantitation of mdr-1/P-glycoprotein in the cell lines of the National Cancer Institute Anticancer Drug Screen

Identifying new chemotherapeutic agents and characterizing mechanisms of resistance may improve cancer treatment. The Anticancer Drug Screen of the National Cancer Institute uses 60 cell lines to identify new agents. Expression of mdr-1/P-glycoprotein was measured by quantitative PCR. Expression was detected in 39 cell lines; the highest levels were in renal and colon carcinomas. Expression was also detected in all melanomas and central nervous system tumors, but in only one ovarian carcinoma and one leukemia cell line. Using a modified version of the COMPARE program, a high correlation was found between expression of mdr-1 and cellular resistance to a large number of compounds. Evidence that these compounds are P-glycoprotein substrates includes: (a) enhancement of cytotoxicity by verapamil; (b) demonstration of cross-resistance in a multidrug-resistant cell line, (c) ability to antagonize P-glycoprotein, increasing vinblastine accumulation by decreasing efflux; and (d) inhibition of photoaffinity labeling by azidopine. Identification of many heretofore unrecognized compounds as substrates indicates that P-glycoprotein has a broader substrate specificity than previously recognized. This study confirms the validity of this novel approach and provides the basis for similar studies examining a diverse group of gene products, including other resistance mechanisms, putative drug targets, and genes involved in the cell cycle and apoptosis.

Deep infections caused by Scedosporium prolificans. A report on 16 cases in Spain and a review of the literature. Scedosporium Prolificans Spanish Study Group

Scedosporium prolificans, a mold morphologically similar to Scedosporium apiospermum, may cause asymptomatic colonization or localized or disseminated infection following trauma, surgery, and immunosuppression. S. prolificans is normally resistant to available antifungal agents, and prognosis depends largely on the host's immune status, extent of infection, and feasibility of surgical debridement. We report on 16 patients with deep S. prolificans infections, focusing on predisposing factors, clinical characteristics, outcome, postmortem findings, and antifungal susceptibility testing to 6 antifungal agents. Between 1989 and 1994, 16 cases of deep infections by S. prolificans were documented in 6 clinical centers in Spain (15 adults and 1 child: male/female = 0.77). Fifteen patients had underlying hematologic malignancy (14 with neutropenia) and 1 had a prosthetic cardiac valve. Syndromes included disseminated infection in 14 patients (1 with prosthetic valve endocarditis) and fungal pneumonia and meningoencephalitis in 1 patient each. S. prolificans was isolated from 2 specimens in 14 patients and from 1 specimen in 2 patients (blood, n = 12; respiratory tract, n = 4; CNS, n = 4; and skin biopsy, n = 3). Antifungal susceptibility testing by a micromethod with RPMI-2% glucose medium was performed in 8 isolates, all of which were resistant to amphotericin B, flucytosine, ketoconazole, fluconazole, itraconazole, and miconazole. All patients received antifungal therapy (amphotericin B, n = 9; amphotericin B+ flucytosine, n = 1; amphotericin B+ itraconazole, n = 2; liposomal amphotericin B+ itraconazole, n = 1; amphotericin B+ fluconazole, n = 1 and 2 underwent surgical procedures. Two patients survived coinciding with hematologic recovery and 14 (87.5%) patients died in a median time of 4 days after the first positive culture (range, 0-60 d). Necropsy was performed in 10 patients, and disseminated infection was found in 9. In conclusion, S. prolificans is an emerging multiresistant fungal pathogen that may cause asymptomatic colonization, localized infection related to trauma or surgery, and rapidly fatal disseminated infection in immunocompromised hosts, particularly those with neutropenia. This mycosis underscores the urgent need for new antifungal agents.

Obstetric hemorrhage: prophylactic and emergency arterial catheterization and embolotherapy

The role of arterial catheterization and embolotherapy was evaluated in 18 patients with postpartum hemorrhage or a risk of hemorrhage. Nine patients underwent emergency arterial catheterization for unanticipated postpartum hemorrhage due to uterine and vaginal tears and/or placental abnormalities. Bleeding was controlled with embolization with gelatin sponge in eight patients, while bleeding in one patient stopped spontaneously during angiography. Nine patients underwent prophylactic arterial catheterization before cesarean section or for abnormalities associated with risk of hemorrhage. Two subsequently underwent embolization before surgery, and embolization in two others was performed intraoperatively in response to serious bleeding. Bleeding in the other five was controlled by the usual surgical means. Arterial embolotherapy in these patients was an effective means of controlling postpartum hemorrhage. Prophylactic arterial catheterization has a role in patients with an increased risk for obstetric hemorrhage.

Ten years of transcriptomics in wild populations: what have we learned about their ecology and evolution?

Molecular ecology has moved beyond the use of a relatively small number of markers, often noncoding, and it is now possible to use whole-genome measures of gene expression with microarrays and RNAseq (i.e. transcriptomics) to capture molecular response to environmental challenges. While transcriptome studies are shedding light on the mechanistic basis of traits as complex as personality or physiological response to catastrophic events, these approaches are still challenging because of the required technical expertise, difficulties with analysis and cost. Still, we found that in the last 10 years, 575 studies used microarrays or RNAseq in ecology. These studies broadly address three questions that reflect the progression of the field: (i) How much variation in gene expression is there and how is it structured? (ii) How do environmental stimuli affect gene expression? (iii) How does gene expression affect phenotype? We discuss technical aspects of RNAseq and microarray technology, and a framework that leverages the advantages of both. Further, we highlight future directions of research, particularly related to moving beyond correlation and the development of additional annotation resources. Measuring gene expression across an array of taxa in ecological settings promises to enrich our understanding of ecology and genome function.

Epidemiology of conjugative plasmid-mediated AmpC beta-lactamases in the United States

A sample of 752 resistant Klebsiella pneumoniae, Klebsiella oxytoca, and Escherichia coli strains from 70 sites in 25 U.S. states and the District of Columbia was examined for transmissibility of resistance to ceftazidime and the nature of the plasmid-mediated beta-lactamase involved. Fifty-nine percent of the K. pneumoniae, 24% of the K. oxytoca, and 44% of the E. coli isolates transferred resistance to ceftazidime. Plasmids encoding AmpC-type beta-lactamase were found in 8.5% of the K. pneumoniae samples, 6.9% of the K. oxytoca samples, and 4% of the E. coli samples, at 20 of the 70 sites and in 10 of the 25 states. ACT-1 beta-lactamase was found at eight sites, four of which were near New York City, where the ACT-1 enzyme was first discovered; ACT-1 beta-lactamase was also found in Massachusetts, Pennsylvania, and Virginia. FOX-5 beta-lactamase was also found at eight sites, mainly in southeastern states but also in New York. Two E. coli strains produced CMY-2, and one K. pneumoniae strain produced DHA-1 beta-lactamase. Pulsed-field gel electrophoresis and plasmid analysis suggested that AmpC-mediated resistance spread both by strain and plasmid dissemination. All AmpC beta-lactamase-containing isolates were resistant to cefoxitin, but so were 11% of strains containing transmissible SHV- and TEM-type extended-spectrum beta-lactamases. A beta-lactamase inhibitor test was helpful in distinguishing the two types of resistance but was not definitive since 24% of clinical isolates producing AmpC beta-lactamase had a positive response to clavulanic acid. Coexistence of AmpC and extended-spectrum beta-lactamases was the main reason for these discrepancies. Plasmid-mediated AmpC-type enzymes are thus responsible for an appreciable fraction of resistance in clinical isolates of Klebsiella spp. and E. coli, are disseminated around the United States, and are not so easily distinguished from other enzymes that mediate resistance to oxyimino-beta-lactams.

Safety and efficacy of the laryngeal mask airway. A prospective survey of 1400 children

A survey of laryngeal mask airway usage in 1400 infants and children by ten trainee anaesthetists was undertaken to provide information about insertion and complication rates using the standard insertion technique and a limited range of standardised anaesthetic techniques. Placement was successful in 90% (1258/1400) at the first attempt, 8% (112/1400) at the second attempt and 2% (29/1400) required an alternative technique of insertion. One patient vomited during insertion and the procedure was abandoned, but aspiration did not occur. The overall problem rate was 11.5% and there were significantly more problems during induction of anaesthesia (p < 0.02). Oxygen saturation decreased below 90% briefly on 23 occasions (1.7%). The incidence of problems was unrelated to the mode of ventilation, or whether isoflurane or total intravenous anaesthesia with propofol was used for maintenance. Most problems came with use of the size 1 laryngeal mask (p < 0.001). The subspecialty with the highest problem rate was ear, nose and throat surgery (p < 0.001). There was a significant decrease in problems with increasing experience (p < 0.001). There was no major morbidity associated with use of the device. We conclude that the laryngeal mask provides a safe and effective form of airway management for infants and children in the hands of supervised anaesthesia trainees both for spontaneous and controlled ventilation using either isoflurane or total intravenous anaesthesia.

Highly sensitive polymer-based cantilever-sensors for DNA detection

We present a technology for the fabrication of cantilever arrays aimed to develop an integrated biosensor microsystem. The fabrication process is based on spin coating of the photosensitive polymer and near-ultraviolet exposure. Arrays of up to 33 microcantilevers are fabricated in the novel polymer material SU-8. The low Young's modulus of the polymer, 40 times lower than that of silicon, enables to improve the sensitivity of the sensor device for target detection. The mechanical properties of SU-8 cantilevers, such as spring constant, resonant frequency and quality factor are characterized as a function of the dimensions and the medium. The devices have been tested for measurement of the adsorption of single stranded DNA and subsequent interstitial adsorption of lateral spacer molecules. We demonstrate that sensitivity is enhanced by a factor of six compared to that of commercial silicon nitride cantilevers.

The effects of fish oil, olive oil, oleic acid and linoleic acid on colorectal neoplastic processes

BACKGROUND AND AIMS

Several nutrients play a significant role in colorectal cancer development, and fats could be among the most determinant. While several studies have shown that the n-3 fatty acids eicosapentaenoic and docosahexaenoic and its main dietary source, fish oil could exert important antineoplastic effects, much less is known about the effects of olive oil and its main fatty acid, oleic acid, and linoleic acid. The aim of these studies is to assess the role of these nutrients in crucial processes involved in colorectal carcinogenesis.

METHODS

Caco-2 and HT-29 colorectal cancer cells were supplemented with different fats and their role in apoptosis induction, cell proliferation, and differentiation was studied. COX-2 and Bcl-2 expressions were also assessed.

RESULTS

Supplementation with fish oil or olive oil results in an induction of apoptosis and cell differentiation. The latest effect was also induced by oleic and linoleic acid. Fish oil diminishes significantly cell proliferation. Supplementation with fish oil and olive oil results in an early downregulation of COX-2 followed by a decrease in Bcl-2 expression.

CONCLUSIONS

Fish oil and olive oil are capable of influencing crucial processes responsible for colorectal cancer development. COX-2 and Bcl-2 may be important mediators of some of these effects.

Transmission of HIV Drug Resistance and the Predicted Effect on Current First-line Regimens in Europe

Transmitted human immunodeficiency virus drug resistance in Europe is stable at around 8%. The impact of baseline mutation patterns on susceptibility to antiretroviral drugs should be addressed using clinical guidelines. The impact on baseline susceptibility is largest for nonnucleoside reverse transcriptase inhibitors.

Background. Numerous studies have shown that baseline drug resistance patterns may influence the outcome of antiretroviral therapy. Therefore, guidelines recommend drug resistance testing to guide the choice of initial regimen. In addition to optimizing individual patient management, these baseline resistance data enable transmitted drug resistance (TDR) to be surveyed for public health purposes. The SPREAD program systematically collects data to gain insight into TDR occurring in Europe since 2001.

Methods. Demographic, clinical, and virological data from 4140 antiretroviral-naive human immunodeficiency virus (HIV)–infected individuals from 26 countries who were newly diagnosed between 2008 and 2010 were analyzed. Evidence of TDR was defined using the WHO list for surveillance of drug resistance mutations. Prevalence of TDR was assessed over time by comparing the results to SPREAD data from 2002 to 2007. Baseline susceptibility to antiretroviral drugs was predicted using the Stanford HIVdb program version 7.0.

Results. The overall prevalence of TDR did not change significantly over time and was 8.3% (95% confidence interval, 7.2%–9.5%) in 2008–2010. The most frequent indicators of TDR were nucleoside reverse transcriptase inhibitor (NRTI) mutations (4.5%), followed by nonnucleoside reverse transcriptase inhibitor (NNRTI) mutations (2.9%) and protease inhibitor mutations (2.0%). Baseline mutations were most predictive of reduced susceptibility to initial NNRTI-based regimens: 4.5% and 6.5% of patient isolates were predicted to have resistance to regimens containing efavirenz or rilpivirine, respectively, independent of current NRTI backbones.

Conclusions. Although TDR was highest for NRTIs, the impact of baseline drug resistance patterns on susceptibility was largest for NNRTIs. The prevalence of TDR assessed by epidemiological surveys does not clearly indicate to what degree susceptibility to different drug classes is affected.

Triose-phosphate isomerase (TIM) of the psychrophilic bacterium Vibrio marinus. Kinetic and structural properties

The purification and characterization of triose-phosphate isomerase from the psychrophilic bacterium Vibrio marinus (vTIM) is described. Crystal structures of the vTIM-sulfate complex and the vTIM-2-phosphoglycolate complex (at a 2.7-A resolution) are also presented. The optimal growth temperature of Vibrio marinus is 15 degrees C. Stability studies show that vTIM is an unstable protein with a half-life of only 10 min at 25 degrees C. The vTIM sequence is most closely related to the sequence of Escherichia coli TIM (eTIM) (66% identity), and several unique structural features described for eTIM are also seen in vTIM, but eTIM is considerably more stable. The Td values of vTIM and eTIM, determined by calorimetric studies, are 41 and 54 degrees C, respectively. Amino acid sequence comparison reveals that vTIM has an alanine in loop 8 (at position 238), whereas all other TIM sequences known to date have a serine. The vTIM mutant A238S was produced and characterized. Compared with wild type, the catalytic efficiency of the A238S mutant is somewhat reduced, and its stability is considerably increased.

Attentional functioning in children and adolescents with IDDM

OBJECTIVE

To determine whether specific attentional cognitive processes are disrupted in children and adolescents with IDDM.

RESEARCH DESIGN AND METHODS

We tested 103 children and adolescents with IDDM and 100 healthy control subjects (age range 9.3-18.3 years) for intelligence and attention. Subjects were given multiple clinical tests of attention and a computerized vigilance test, all of which served to provide information about multiple components of attentional processing. Specific components studied were the abilities to focus, select, shift, suppress, inhibit, and sustain attention. A diabetic history was obtained for the IDDM group, and blood glucose levels were determined before and after computerized attention testing.

RESULTS

Across tests, IDDM subjects differed from control subjects only in the select component of attention, which was accounted for mainly by the poorer performance of children with early-onset diabetes (< 6 years). When subgrouped by history of seizures from hypoglycemia, those having had seizures demonstrated a lower verbal IQ and greater difficulty with select, focus, and inhibit attentional components, whereas sustain, suppress, and shift attentional components were unaffected. Correlation analyses showed that higher concurrent blood glucose levels were associated with less adequate ability to inhibit impulsive responses, whereas multiple regression analyses indicated that inhibit and focus were best predicted by onset age and concurrent blood glucose.

CONCLUSIONS

In children and adolescents with IDDM, attention is poorer in several but not all aspects of attention; these aspects are affected by a history of seizures from hypoglycemia and higher ambient blood glucose levels at time of testing. These results suggest both organizational and activational effects of diabetes on specific subcomponents of attention in diabetes.

Fluid shear stress induces beta-catenin signaling in osteoblasts

beta-Catenin plays a dual role in cells: one at cell-cell junctions and one regulating gene transcription together with TCF (T-cell Factor) in the nucleus. Recently, a role for beta-catenin in osteoblast differentiation and gene expression has begun to be elucidated. Herein we investigated the effects of fluid shear stress (FSS) on beta-catenin signaling. FSS is a well-characterized anabolic stimulus for osteoblasts; however, the molecular mechanisms for the effects of this stimulation remain largely unknown. We found that 1 hour of laminar FSS (10 dynes/cm(2)) induced translocation of beta-catenin to the nucleus and activated a TCF-reporter gene. Analysis of upstream signals that may regulate beta-catenin signaling activity revealed two potential mechanisms for increased beta-catenin signaling. First, FSS induced a transient, but significant, increase in the phosphorylation of both glycogen synthase kinase 3beta (GSK-3beta) and Akt. Second, FSS reduced the levels of beta-catenin associated with N-cadherin, suggesting that less sequestration of beta-catenin by cadherins occurs in osteoblasts subjected to FSS. Functional analysts of potential genes regulated by beta-catenin signaling in osteoblasts revealed two novel observations. First, endogenous, nuclear beta-catenin purified from osteoblasts formed a complex with a TCF -binding element in the cyclooxygenase-2 promoter, and, second, overexpression of either a constitutively active beta-catenin molecule or inhibition of GSK-3beta activity increased basal cyclooxygenase-2 levels. Together, these data demonstrate for the first time that FSS modulates the activity of both GSK-3beta and beta-catenin and that these signaling molecules regulate cyclooxygenase-2 expression in osteoblasts.

Therapeutic efficacy of unilateral subthalamotomy in Parkinson's disease: results in 89 patients followed for up to 36 months

BACKGROUND

Stereotactic thermocoagulative lesions of the subthalamic nucleus (STN) have been shown to induce significant motor improvement in patients with Parkinson's disease (PD).

PATIENTS AND METHODS

89 patients with PD were treated with unilateral subthalamotomy. 68 patients were available for evaluations after 12 months, 36 at 24 months and 25 at 36 months.

RESULTS

The Unified Parkinson's Disease Rating Scale (UPDRS) motor scores improved significantly contralaterally to the lesion in the "off" and "on" states throughout the follow-up, except for the "on" state at the last evaluation. Axial features and signs ipsilateral to the lesion progressed steadily throughout the study. Levodopa daily doses were significantly reduced by 45%, 36% and 28% at 12, 24 and 36 months post-surgery. 14 patients (15%) developed postoperative hemichorea-ballism which required pallidotomy in eight. These 14 patients had significantly higher dyskinesia scores (levodopa induced) preoperatively than the entire cohort.

CONCLUSION

Unilateral subthalamotomy was associated with significant and sustained motor benefit contralateral to the lesion. Further work is needed to ascertain what factors led to severe, persistent chorea-ballism in a subset of patients. Subthalamotomy may be considered an option in circumstances when deep brain stimulation is not viable.

Fatal dengue hemorrhagic fever in Cuba, 1997

OBJECTIVES

After more than 15 years without dengue activity, a dengue II epidemic was reported in Cuba in 1997. Three thousand and twelve serologically confirmed cases were reported, with 205 dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) cases and 12 fatalities. This report presents the clinical, serologic, and virologic findings in the 12 fatal DHF/DSS cases.

METHODS

Serum and necropsy samples were studied by viral isolation in C636 cell line and polymerase chain reaction. Serum samples were tested by IgM capture enzyme-linked immunoassay (ELISA) and ELISA inhibition method (EIM).

RESULTS

All 12 cases were classified as DHF/DSS according to the Pan American Health Organization Guidelines for Control and Prevention of Dengue and Dengue Hemorrhagic Fever in the Americas. All patients were older than 15 years. Women were more frequently affected. The symptoms and signs presented by these patients were similar to those previously described in DHF/DSS cases. Clinical deterioration occurred on average at day 3.75. Abdominal pain and persistent vomiting were the earliest and most frequent warning signs. Dengue infection was confirmed in all cases. IgM antibodies were detected in 11 of 12 cases, all of them with a secondary infection. Dengue II virus was detected by viral isolation in 12 samples and by polymerase chain reaction in 17. Virus or RNA was detected in various tissues, including kidney, heart, lung, and brain.

CONCLUSION

The clinical, pathologic, and laboratory features of 12 cases of fatal dengue hemorrhagic fever were reviewed. The results obtained demonstrate that adults with a primary dengue infection are at risk of developing the severe disease (DHF) if they are infected with a different serotype.

Effect of olive oil on early and late events of colon carcinogenesis in rats: modulation of arachidonic acid metabolism and local prostaglandin E(2) synthesis

BACKGROUND

Animal model studies have shown that the colon tumour promoting effect of dietary fat depends not only on the amount but on its fatty acid composition. With respect to this, the effect of n9 fatty acids, present in olive oil, on colon carcinogenesis has been scarcely investigated.

AIMS

To assess the effect of an n9 fat diet on precancer events, carcinoma development, and changes in mucosal fatty acid composition and prostaglandin (PG)E(2) formation in male Sprague-Dawley rats with azoxymethane induced colon cancer.

METHODS

Rats were divided into three groups to receive isocaloric diets (5% of the energy as fat) rich in n9, n3, or n6 fat, and were administered azoxymethane subcutaneously once a week for 11 weeks at a dose rate of 7.4 mg/kg body weight. Vehicle treated groups received an equal volume of normal saline. Groups of animals were colectomised at weeks 12 and 19 after the first dose of azoxymethane or saline. Mucosal fatty acids were assessed at 12 and 19 weeks. Aberrant crypt foci and the in vivo intracolonic release of PGE(2) were assessed at week 12, and tumour formation at week 19.

RESULTS

Rats on the n6 diet were found to have colonic aberrant crypt foci and adenocarcinomas more often than those consuming either the n9 or n3 diet. There were no differences between the rats on the n9 and n3 diets. On the other hand, administration of both n9 and n3 diets was associated with a decrease in mucosal arachidonate concentrations as compared with the n6 diet. Carcinogen treatment induced an appreciable increase in PGE(2) formation in rats fed the n6 diet, but not in those fed the n3 and n9 diets.

CONCLUSIONS

Dietary olive oil prevented the development of aberrant crypt foci and colon carcinomas in rats, suggesting that olive oil may have chemopreventive activity against colon carcinogenesis. These effects may be partly due to modulation of arachidonic acid metabolism and local PGE(2) synthesis.

The presence of cervical and vaginal fetal fibronectin predicts preterm delivery in an inner-city obstetric population

OBJECTIVE

It has previously been shown that fibronectin bearing a specific oncofetal domain is present at the chorionic-decidual interface and that its release into cervical and vaginal secretions accurately predicts preterm delivery in patients with uterine contractions. This study examines whether serial assessment of cervical and vaginal fetal fibronectin allows for the prediction of preterm delivery in symptom-free patients derived from an inner-city, general obstetric population.

STUDY DESIGN

Cervical and vaginal samples were obtained from 429 consenting patients who received routine prenatal care between 24 and 37 weeks' gestation. A sensitive immunoassay was used to quantitate cervical and vaginal fetal fibronectin levels, and clinicians were blinded to fetal fibronectin results. Post hoc receiver operating characteristic curve analysis was used to determine which sample site (cervical or vaginal), fetal fibronectin concentration, and number of consecutive positive samples optimized screening efficacy. Logistic regression was employed to determine whether fetal fibronectin was an independent predictor of preterm delivery.

RESULTS

The spontaneous preterm delivery rate was 11% (49/429). Among the 326 patients sampled within 28 days of delivery, receiver operating characteristic curve analysis indicated that the presence of a single cervical fetal fibronectin value > 60 ng/ml between 24 and 36 weeks' gestation predicted preterm delivery with a sensitivity of 73%, a specificity of 72%, and positive and negative predictive values of 25% and 95%, respectively. A vaginal fetal fibronectin value > 50 ng/ml predicted preterm delivery with a sensitivity of 68%, a specificity of 80%, and positive and negative predictive values of 30% and 95%, respectively. Cervical and vaginal fetal fibronectin predicted preterm deliveries resulting from both membrane rupture and preterm labor with intact membranes. A positive fetal fibronectin result preceded preterm delivery by 3.4 (+/- 3.2) weeks. Stepwise logistic regression demonstrated that cervical and vaginal fetal fibronectin levels were independent predictors of preterm delivery with adjusted odds ratios of 8.9 (95% confidence interval 3.6 to 22.1) and 6.0 (95% confidence interval 2.6 to 13.7), respectively.

CONCLUSIONS

Among patients undergoing monthly cervical and vaginal sampling between 24 and 36 weeks' gestation, the presence of fetal fibronectin is a sensitive and specific predictor of preterm delivery.

Genetic and epigenetic differences associated with environmental gradients in replicate populations of two salt marsh perennials

While traits and trait plasticity are partly genetically based, investigating epigenetic mechanisms may provide more nuanced understanding of the mechanisms underlying response to environment. Using AFLP and methylation-sensitive AFLP, we tested the hypothesis that differentiation to habitats along natural salt marsh environmental gradients occurs at epigenetic, but not genetic loci in two salt marsh perennials. We detected significant genetic and epigenetic structure among populations and among subpopulations, but we found multilocus patterns of differentiation to habitat type only in epigenetic variation for both species. In addition, more epigenetic than genetic loci were correlated with habitat in both species. When we analysed genetic and epigenetic variation simultaneously with partial Mantel, we found no correlation between genetic variation and habitat and a significant correlation between epigenetic variation and habitat in Spartina alterniflora. In Borrichia frutescens, we found significant correlations between epigenetic and/or genetic variation and habitat in four of five populations when populations were analysed individually, but there was no significant correlation between genetic or epigenetic variation and habitat when analysed jointly across the five populations. These analyses suggest that epigenetic mechanisms are involved in the response to salt marsh habitats, but also that the relationships among genetic and epigenetic variation and habitat vary by species. Site-specific conditions may also cloud our ability to detect response in replicate populations with similar environmental gradients. Future studies analysing sequence data and the correlation between genetic variation and DNA methylation will be powerful to identify the contributions of genetic and epigenetic response to environmental gradients.