Gut resident Escherichia coli profile predicts the eighteen-month probability and antimicrobial susceptibility of urinary tract infections

Background

Community-acquired UTI is the most common bacterial infection managed in general medical practice that can lead to life-threatening outcomes. While UTIs are primarily caused by Escherichia coli colonizing the patient's gut, it is unclear whether the gut resident E. coli profiles can predict the person's risks for UTI and optimal antimicrobial treatments. Thus, we conducted an eighteen-month long community-based observational study of fecal E. coli colonization and UTI in women aged 50 years and above.

Methods and Findings

We enrolled a total of 1,804 women distributed among age groups 50-59 yo (437 participants), 60-69 yo (632), 70-79 yo (532), and above 80 yo (203), lacking antibiotic prescriptions for at least one year. The provided fecal samples were plated for the presence of E. coli and other enterobacteria resistant to trimethoprim/sulfamethoxazole (TMP/STX), ciprofloxacin (CIP) and 3rd generation cephalosporins (3GC). E. coli was also characterized as belonging to the pandemic multi-drug resistant clonal groups ST131 (subclone H30) and ST1193. Following sample collection, the women were monitored for 18 months for occurrence of UTI.E. coli was cultured from 90.8% fecal samples, with 24.1% containing bacteria resistant to TMP/STX, 19.4% to CIP, and 7.9% to 3GC. In 62.5% samples, only all-susceptible E. coli were present. Overall, there were no age-related differences in resistance prevalence. However, while the total E. coli H30 and ST1193 carriage rates were similar (4.3% and 4.2%, respectively), there was a notable increase of H30 carriage with age (P = .001), while carriage decreased with age for ST1193 (P = .057).Within 18 months, 184 women (10.2%) experienced at least one episode of UTI - 10.9% among the gut E. coli carriers and 3.0% among the non-carriers (P=.0013). The UTI risk among carriers of E. coli H30 but not ST1193 was significantly above average (24.3%, P = .0004). The UTI probability increased with age, occurring in 6.4% of 50-59 yo and 19.7% of 80+ yo (P<.001), with the latter group being especially at high risk for UTI, if they were colonized by E. coli H30 (40.0%, P<.001).E. coli was identified in 88.1% of urine samples, with 16.1% resistant to TMP/STX, 16.1% to CIP, 4.2% to 3GC and 73.1% to none of the antibiotics. Among tested urinary E. coli resistant to antibiotics, 86.1% matched the resistance profile of E. coli in the fecal samples, with the clonotyping and whole genome sequencing confirming the matching strains' identity. Positive predictive value (PPV) of using gut resistance profiles to predict UTI pathogens' susceptibility to TMP/STX, CIP, 3GC and all three antibiotics were 98.4%, 98.3%, 96.6% and 95.3%, respectively. Corresponding negative predictive values (NPV) were 63.0%, 54.8%, 44.4% and 75.8%, respectively. The AUC ROC curve values for the accuracy of fecal diagnostic testing for the prediction of UTI resistance ranged .86-.89. The fecal test-guided drug-bug mismatch rate for empirical (pre-culture) prescription of TMP-SXT or CIP is reduced to ≤2% in 89.6% of patients and 94.8% of patients with an optional 3GC prescription.

Conclusion

The resistance profile and clonal identity of gut colonizing E. coli, along with the carrier's age, can inform personalized prediction of a patients' UTI risk and the UTI pathogen's antibiotic susceptibility within an 18-month period.

Increase in the community circulation of ciprofloxacin-resistant Escherichia coli despite reduction in antibiotic prescriptions

BACKGROUND

Community circulating gut microbiota is the main reservoir for uropathogenic Escherichia coli, including those resistant to antibiotics. Ciprofloxacin had been the primary antibiotic prescribed for urinary tract infections, but its broad use has been discouraged and steadily declined since 2015. How this change in prescriptions affected the community circulation of ciprofloxacin-resistant E. coli is unknown.

METHODS

We determined the frequency of isolation and other characteristics of E. coli resistant to ciprofloxacin in 515 and 1604 E. coli-positive fecal samples collected in 2015 and 2021, respectively. The samples were obtained from non-antibiotic-taking women of age 50+ receiving care in the Kaiser Permanente Washington healthcare system.

RESULTS

Here we show that despite a nearly three-fold drop in the prescription of ciprofloxacin between 2015 and 2021, the rates of gut carriage of ciprofloxacin-resistant E. coli increased from 14.2 % to 19.8% (P = .004). This is driven by a significant increase of isolates from the pandemic multi-drug resistant clonal group ST1193 (1.7% to 4.2%; P = .009) and isolates with relatively few ciprofloxacin-resistance determining chromosomal mutations (2.3% to 7.4%; P = .00003). Though prevalence of isolates with the plasmid-associated ciprofloxacin resistance dropped (59.0% to 30.9%; P = 2.7E-06), the isolates co-resistance to third generation cephalosporins has increased from 14.1% to 31.5% (P = .002).

CONCLUSIONS

Despite reduction in ciprofloxacin prescriptions, community circulation of the resistant uropathogenic E. coli increased with a rise of co-resistance to third generation cephalosporins. Thus, to reduce the rates of urinary tract infections refractory to antibiotic treatment, greater focus should be on controlling the resistant bacteria in gut microbiota.

Increase in the Rate of Gut Carriage of Fluoroquinolone-Resistant Escherichia coli despite a Reduction in Antibiotic Prescriptions

Background : Fluoroquinolone use for urinary tract infections has been steadily declining. Gut microbiota is the main reservoir for uropathogenic Escherichia coli but whether the carriage of fluoroquinolone-resistant E. coli has been changing is unknown. Methods . We determined the frequency of isolation and other characteristics of E. coli nonsuceptible to fluoroquinolones (at ³0.5 mg/L of ciprofloxacin) in 515 and 1605 E. coli -positive fecal samples collected in 2015 and 2021, respectively, from non-antibiotic- taking women of age 50+ receiving care in the Seattle area Kaiser Permanente Washington healthcare system. Results . Between 2015 and 2021 the prescription of fluoroquinolones dropped nearly three-fold in the study population. During the same period, the rates of gut carriage of fluoroquinolone-resistant E. coli increased from 14.4 % to 19.9% (P=.005), driven by a significant increase of isolates from the recently emerged, pandemic multi-drug resistant clonal group ST1193 (1.7% to 4.3%; P=.007) and those with an incomplete set of or no fluoroquinolone-resistance determining mutations (2.3% to 7.5%; P<.001). While prevalence of the resistance-associated mobile genes among the isolates dropped from 64.1% to 32.6% (P<.001), co-resistance to third generation cephalosporins has increased 21.5% to 33.1%, P=.044). Conclusion . Despite reduction in fluoroquinolone prescriptions, gut carriage of fluoroquinolone-resistant uropathogenic E. coli increased with a rise of previously sporadic lineages and co-resistance to third generation cephalosporins. Thus, to reduce the rates of antibiotic resistant urinary tract infections, greater focus should be on controlling the gut carriage of resistant bacteria.

What are the barriers and facilitators to community handwashing with water and soap? A systematic review

Handwashing with water and soap (HWWS) is an effective method of cleaning and disinfecting the surface of the hands. HWWS is effective in infection control and prevention transmission, such as in Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). However, rates of handwashing compliance vary globally. This systematic review aimed to identify the barriers and facilitators to community HWWS globally. We conducted a comprehensive search strategy in OVID Medline, OVID Embase, Web of Science Core Collection, and Scopus using keywords and subject headings related to handwashing. Studies were excluded if they reported hand hygiene among healthcare or food service workers, considered the use of alcohol rubs, or involved an intervention in a healthcare or food preparation setting. The quality of eligible studies was assessed using the Mixed Methods Appraisal Tool, and data were extracted from the articles and analyzed using the Theoretical Domains Framework and inductive thematic analysis. The search strategy yielded a total of 11,696 studies, and 46 studies met the eligibility criteria. Study dates ranged from 2003 to 2020 and included 26 countries; the most frequently represented were Bangladesh, India, and Kenya. A total of 21 barriers and 23 facilitators to HWWS were identified and organized into the Theoretical Domains Framework. The most frequently cited domains were environmental context and resources, goals, and knowledge. Nine themes emerged from these barriers and facilitators: resource availability, cost and affordability, handwash station design and infrastructure, accessibility, gender roles, champions, health promotion, time management, and knowledge, beliefs, and behaviors. This review uncovered multiple barriers and facilitators around a determinant framework to observe and create an in-depth, multidimensional image of a community-based hand hygiene situation. New comprehensive interventions and implementation strategies can be developed using the findings to target the contextual barriers and facilitators to improve and increase HWWS rates. Stakeholders (i.e., practitioners, researchers, policymakers) can use the findings to revise, design, or evaluate new or existing projects, interventions, and policies to improve HWWS. Registration: A protocol for this systematic review was developed and uploaded onto the PROSPERO-International prospective register of systematic reviews database (Registration number: CRD42020221210).

Oncogenic switch and single-agent MET inhibitor sensitivity in a subset of EGFR-mutant lung cancer

[Figure: see text].

Optimal Time to Ship Human Islets Post Tissue Culture to Maximize Islet

Access to functional high-quality pancreatic human islets is critical to advance diabetes research. The Integrated Islet Distribution Program (IIDP), a major source for human islet distribution for over 15 years, conducted a study to evaluate the most advantageous times to ship islets postisolation to maximize islet recovery. For the evaluation, three experienced IIDP Islet Isolation Centers each provided samples from five human islet isolations, shipping 10,000 islet equivalents (IEQ) at four different time periods postislet isolation (no 37°C culture and shipped within 0 to 18 hours; or held in 37°C culture for 18 to 42, 48 to 96, or 144 to 192 hours). A central evaluation center compared samples for islet quantity, quality, and viability for each experimental condition preshipment and postshipment, as well as post 37°C culture 18 to 24 hours after shipment receipt. Additional evaluations included measures of functional potency by static glucose-stimulated insulin release (GSIR), represented as a stimulation index. Comparing the results of the four preshipment holding periods, the greatest IEQ loss postshipment occurred with the shortest preshipment times. Similar patterns emerged when comparing preshipment to postculture losses. In vitro islet function (GSIR) was not adversely impacted by increased tissue culture time. These data indicate that allowing time for islet recovery postisolation, prior to shipping, yields less islet loss during shipment without decreasing islet function.

Characterization of chelator-mediated recovery of pancreatic islets from barium-stabilized alginate microcapsules

INTRODUCTION

Islet recovery from within alginate-based microcapsules is necessary for certain analytical assays like flow cytometry; however, this technology has not been widely characterized. In this study, we explore the ability of EDTA, EGTA, and sodium citrate to induce reverse alginate polymerization via chelation and assess the toxicity of each chelator on pancreatic islets.

METHODS

EDTA, EGTA, and sodium citrate were used to dissolve single-layered Ba²⁺ alginate encapsulated islets and the rate of capsule breakdown calculated from analysis of imaging data. The effect of chelator exposure on islet viability and recovery was assessed using flow cytometry, while glucose-stimulated insulin release (GSIR) assay was used to measure effects on islet function.

RESULTS

EGTA demonstrated the most rapid microcapsule dissolving rate followed by EDTA and sodium citrate. Islet recovery was significantly better when encapsulated islets were treated with EDTA than EGTA and Na⁺ citrate. A decrease in viability and increase in apoptotic cells were observed when encapsulated islets were treated with Na⁺ citrate compared to islets treated with EDTA and EGTA. Islets treated with EDTA and EGTA demonstrated comparable stimulation index values to non-treated control. Conversely, islets treated with Na⁺ citrate exhibited significantly decreased SI values compared to control. All chelator groups showed significantly lower insulin secretion than non-treated islets.

CONCLUSION

Islet recovery from alginate microcapsule is possible using common chelators like Na⁺ citrate, EDTA, and EGTA. Chelation of encapsulated islets using EDTA demonstrated the most efficient dissolving capabilities with the least toxicity toward islet recovery and health.

Unbiased Hamiltonian Monte Carlo with couplings

We propose a method for parallelization of Hamiltonian Monte Carlo estimators. Our approach involves constructing a pair of Hamiltonian Monte Carlo chains that are coupled in such a way that they meet exactly after some random number of iterations. These chains can then be combined so that the resulting estimators are unbiased. This allows us to produce independent replicates in parallel and average them to obtain estimators that are consistent in the limit of the number of replicates, rather than in the usual limit of the number of Markov chain iterations. We investigate the scalability of our coupling in high dimensions on a toy example. The choice of algorithmic parameters and the efficiency of our proposed approach are then illustrated on a logistic regression with 300 covariates and a log-Gaussian Cox point processes model with low- to fine-grained discretizations.

Discrimination of Germline EGFR T790M Mutations in Plasma Cell-Free DNA Allows Study of Prevalence Across 31,414 Cancer Patients

Purpose: Plasma cell-free DNA (cfDNA) analysis is increasingly used clinically for cancer genotyping, but may lead to incidental identification of germline-risk alleles. We studied EGFR T790M mutations in non-small cell lung cancer (NSCLC) toward the aim of discriminating germline and cancer-derived variants within cfDNA.Experimental Design: Patients with EGFR-mutant NSCLC, some with known germline EGFR T790M, underwent plasma genotyping. Separately, deidentified genomic data and buffy coat specimens from a clinical plasma next-generation sequencing (NGS) laboratory were reviewed and tested.Results: In patients with germline T790M mutations, the T790M allelic fraction (AF) in cfDNA approximates 50%, higher than that of EGFR driver mutations. Review of plasma NGS results reveals three groups of variants: a low-AF tumor group, a heterozygous group (∼50% AF), and a homozygous group (∼100% AF). As the EGFR driver mutation AF increases, the distribution of the heterozygous group changes, suggesting increased copy number variation from increased tumor content. Excluding cases with high copy number variation, mutations can be differentiated into somatic variants and incidentally identified germline variants. We then developed a bioinformatic algorithm to distinguish germline and somatic mutations; blinded validation in 21 cases confirmed a 100% positive predictive value for predicting germline T790M. Querying a database of 31,414 patients with plasma NGS, we identified 48 with germline T790M, 43 with nonsquamous NSCLC (P < 0.0001).Conclusions: With appropriate bioinformatics, plasma genotyping can accurately predict the presence of incidentally detected germline risk alleles. This finding in patients indicates a need for genetic counseling and confirmatory germline testing. Clin Cancer Res; 23(23); 7351-9. ©2017 AACR.

Association Between Younger Age and Targetable Genomic Alterations and Prognosis in Non-Small-Cell Lung Cancer

IMPORTANCE

Non-small-cell lung cancer (NSCLC) diagnosed in young patients is rare, and the genomics and clinical characteristics of this disease are poorly understood. In contrast, the diagnosis of other cancers at a young age has been demonstrated to define unique disease biology. Herein, we report on the association of young age with targetable genomic alterations and prognosis in a cohort of 2237 patients with NSCLC.

OBJECTIVE

To determine the relationship between young age at diagnosis and the presence of a potentially targetable genomic alteration, disease prognosis, and natural history.

DESIGN, SETTING, AND PARTICIPANTS

A cohort of all 2237 patients with NSCLC who were genotyped at the Dana-Farber Cancer Institute between January 2002 and December 2014 were identified. Tumor genotype, patient characteristics, and clinical outcomes were collected and studied at a National Cancer Institute-designated comprehensive cancer center. Multivariate logistic regression was used to analyze the relationship between age and mutation status, and multivariate Cox proportional hazard models were fitted for survival analysis.

MAIN OUTCOMES AND MEASURES

The frequency of targetable genomic alterations by defined age categories as well as the association of these age groups with survival. Age categories used in this analysis were younger than 40, 40 to 49, 50 to 59, 60 to 69, and 70 years or older.

RESULTS

A cohort of 2237 patients with NSCLC was studied. Of the 2237 participants, 1939 (87%) had histologically confirmed adenocarcinoma, 269 (12%) had NSCLC not otherwise specified, and 29 (1%) had squamous histologic findings; 1396 (63%) had either stage IIIB or IV cancers; and median (range) age was 62 (20-95) years. We found that gene mutations for EGFR (P = .02) and ALK (P < .001) were associated with cancer diagnosis at a younger age, and a similar trend existed for ERBB2 (P = .15) and ROS1 (P = .10) but not BRAF V600E (P = .43). Among patients tested for all 5 targetable genomic alterations (n = 1325), younger age was associated with an increased frequency of a targetable genotype (P < .001). Those diagnosed at 50 years or younger have a 59% increased likelihood of harboring a targetable genotype. While presence of a potentially targetable genomic alteration treated with a targeted agent was associated with improved survival, the youngest and oldest age groups had similarly poor outcomes even when a targetable genotype was present.

CONCLUSIONS AND RELEVANCE

Younger age is associated with an increased likelihood of harboring a targetable genotype and is an underappreciated clinical biomarker in NSCLC. The survival of young patients with NCSLC is unexpectedly poor compared with other age groups, suggesting more aggressive disease biology. These findings underscore the importance of comprehensive genotyping, including next-generation sequencing, in younger patients with lung cancer.

Systematic chemical and molecular profiling of MLL-rearranged infant acute lymphoblastic leukemia reveals efficacy of romidepsin

To address the poor prognosis of mixed lineage leukemia (MLL)-rearranged infant acute lymphoblastic leukemia (iALL), we generated a panel of cell lines from primary patient samples and investigated cytotoxic responses to contemporary and novel Food and Drug Administration-approved chemotherapeutics. To characterize representation of primary disease within cell lines, molecular features were compared using RNA-sequencing and cytogenetics. High-throughput screening revealed variable efficacy of currently used drugs, however identified consistent efficacy of three novel drug classes: proteasome inhibitors, histone deacetylase inhibitors and cyclin-dependent kinase inhibitors. Gene expression of drug targets was highly reproducible comparing iALL cell lines to matched primary specimens. Histone deacetylase inhibitors, including romidepsin (ROM), enhanced the activity of a key component of iALL therapy, cytarabine (ARAC) in vitro and combined administration of ROM and ARAC to xenografted mice further reduced leukemia burden. Molecular studies showed that ROM reduces expression of cytidine deaminase, an enzyme involved in ARAC deactivation, and enhances the DNA damage-response to ARAC. In conclusion, we present a valuable resource for drug discovery, including the first systematic analysis of transcriptome reproducibility in vitro, and have identified ROM as a promising therapeutic for MLL-rearranged iALL.

Abstract 4250: 5′ deletion on ALK break-apart FISH and risk of false positive results

Purpose:

Break-apart fluorescence in situ hybridization (FISH) is the FDA-approved assay for detecting anaplastic lymphoma kinase (ALK) rearrangements in non-small cell lung cancer (NSCLC), identifying patients (pts) who may benefit from ALK tyrosine kinase inhibitors (TKIs). A case is considered positive for rearrangement either based on split 3′ and 5′ signals or loss of the 5′ signal (5′ deletion). We hypothesized that 5′ deletion on FISH may not be completely specific for presence of rearrangement, making the assay vulnerable to false positive results.

Methods:

An institutional IRB-approved database of NSCLC pts was queried for those with ALK-rearrangements. Clinical characteristics and response to ALK TKIs were reviewed. Immunohistochemistry (IHC) and next-generation sequencing (NGS) were obtained to further characterize ALK status.

Results:

Of 1614 NSCLC pts with ALK testing, 97 (6.0%) patients had abnormal ALK FISH: 30 with split signals, 24 with 5′ deletion, 3 with 3′ deletion, 1 with atypical rearrangement, and 39 with details unavailable. Pts with 5′ deletion were older (p = 0.01), had a more extensive smoking history (p = 0.03), and were more likely to harbor mutations in EGFR or KRAS (2 cases vs 0). Pts with 5′ deletion treated with ALK TKIs had a trend toward less tumor shrinkage (p = 0.07). ALK IHC and FISH were discordant in 3 of 21 pts with 5′ deletion and 0 of 26 pts with split signals (p = 0.03). NGS was concordant with ALK IHC, but not FISH, in 2 of 7 samples with 5′ deletions. All three testing modalities were concordant in 3 samples with split signals.

Conclusions:

NSCLC pts with 5′ deletion on ALK FISH have clinical and molecular features less typical of ALK-rearranged tumors, suggesting an unappreciated risk of false positives with this assay. While the majority of patients with 5′ deletion on ALK FISH harbor a true rearrangement and respond to ALK TKI, confirming these cases with IHC or NGS could reduce the false positive rate.

Table 1.Clinicopathologic Features of NSCLC patients with positive ALK FISHSplit Signals (N = 30)5″ Deletion (N = 24)p-valueAge at Diagnosis - yearsp = 0.01MedianRange22-8228-76Age Distribution - No. (%)&lt;40517%14%40-491033%28%50-59827%1042%60-69413%833%&gt;70310%313%Race - No. (%)p = 0.03Caucasian2480%2188%Asian27%28%Other413%14%Smoking History - No. (%)p = 0.03Never Smoker1963%1042%Light Smoker (&lt;10py)620%729%Heavy Smoker517%625%Presence of Co-MutationsEGFR00%14%KRAS00%14%None30100%2292%ALK Immunohistochemistryp = 0.03Positive26100%1886%Negative00%314%Next-Generation SequencingPositive3100%571%Negative00%229%

Citation Format: Xin Gao, Lynette M. Sholl, Mizuki Nishino, Jennifer Heng, Pasi A. Janne, Geoffrey R. Oxnard. 5′ deletion on ALK break-apart FISH and risk of false positive results. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4250. doi:10.1158/1538-7445.AM2015-4250

Myeloid differentiation factor 88 gene is involved in antiviral immunity in grass carp Ctenopharyngodon idella

A full-length MyD88 cDNA (CiMyD88) was cloned and characterized from grass carp Ctenopharyngodon idella. CiMyD88 was found to be broadly expressed and was up-regulated by grass carp reovirus (GCRV) and CiMyD88 transcripts in vitro were rapidly elevated in C. idella kidney (CIK) cells after challenge with poly(I:C). These results suggest that CiMyD88 may be involved in the antiviral immune defence in C. idella.

Small-Signal Performance and Modeling of sub-50nm nMOSFETs with f above 460-GHz

We have fabricated and tested the performance of sub-50nm gate nMOSFETs to assess their suitability for mixed signal applications in the super high frequency (SHF) band, i.e. 3-30GHz. For a 30nm×40 μm×2 device, we found f(T) =465GHz at V(ds)=2V, V(g)=0.67V, which is the highest cut-off frequency reported for a MOSFET produced on bulk silicon substrate so far. However, our measurements of f(max) and noise figure indicate that parasitics impose limitations on SHF operation. We also present a high-frequency ac model appropriate to sub-50nm gate length nanotransistors, which incorporates the effects of the parasitics. The model accurately accounts for measurements of the S and Y parameters in the frequency range from 1 to 50GHz.

Redescription of Steinernema longicaudum Shen & Wang (Nematoda: Steinernematidae); geographic distribution and phenotypic variation between allopatric populations

Steinernema longicaudum Shen & Wang is redescribed based on a comparative morphological study of specimens from the type isolate from China, and two other isolates recovered from Korea and the USA. For the first and second generation female, the location of the vulva, shape of the vulval lips, and shape and length of the tail were newly observed diagnostic characters. A more detailed description of the morphology of the male spicules and gubernaculum, and the arrangement of the genital papillae is included. A description, based on scanning electron microscopy observations, of the lateral field pattern of the third-stage infective juveniles is also provided. Additionally, restriction fragment length polymorphism profiles based on the internal transcribed spacer region, and cross-breeding tests supplement the description of this species.

Effect of vapor-flame treatment on plasma sprayed hydroxyapatite coatings

A vapor-flame treatment was developed to modify the crystallinity of the as-sprayed hydroxyapatite (HA) coatings. The effects of the treatment on composition, structure, and properties of HA coatings were investigated. Results showed that the vapor-flame treatment is simple and efficient to adjust the crystallinity of as-sprayed HA coating. Its crystallinities can be raised from 53.5 to 98.7% in 3-7 min. The porosities of coatings increased with an increase in the vapor-flame treating time. The microhardness of coating decreased as a result of this treatment. It may be explained in terms of the extent of microcracks caused by recrystallization of amorphous HA and relaxation of stress of the coating. The porosity, bonding strength, and hardness of HA coatings treated for 7 min were 15.7%, 32.0 MPa (300 microm thickness), and 1.9 GPa, respectively.

Low-dose oral type I interferons reduce early virus replication of murine cytomegalovirus in vivo

Immunity to viral infections involves both innate and antigen-specific immune responses. The antiviral properties of interferons (IFNs) are part of the innate immune response. Low doses of type I IFNs (IFN-alpha and IFN-beta) administered daily (10 IU per mouse) by the oral route significantly reduced the early replication of murine cytomegalovirus (MCMV) in both the spleen and liver of MCMV-infected susceptible BALB/c mice. Significant inhibition of virus replication was observed for two different inoculum doses of virus (2 x 10(4) pfu per mouse [0.6 LD50] and 2 x 10(4.12) pfu per mouse [0.8 LD50]). Analysis of IFN retention, using [35S]-labeled IFN-alpha1 compared with the nonreceptor binding mutant IFN-alpha1 (R33M) administered orally to mice, revealed binding of wild-type IFN-alpha1 to several tissues. In particular, IFN was retained by tissues proximal to lymphoid regions, including the posterior nasal cavity, posterior tongue, small intestine, and rectum. These findings suggest that type I IFNs may inhibit MCMV replication by distal binding of the orally administered IFN to various tissues, which in turn augment the primary immune response to virus infection.

Implications of malignant lymphoma on a periapical mandibular lesion

A patient who sought treatment complained of numbness. A periapical radiolucency had been observed some weeks earlier. He was subsequently treated with endodontic therapy. When he later developed soft-tissue swelling, he was treated with antibiotics. The treatment modalities were consistent with infection control. However, review of the patient's medical history of malignancy would have alerted the dentist to a possible case of metastasis.

MEF2C, a MADS/MEF2-family transcription factor expressed in a laminar distribution in cerebral cortex

We have cloned cDNA encoding a human transcription factor that belongs to the MEF2 (myocyte-specific enhancer-binding factor 2) subfamily of the MADS (MCM1-agamous-deficiens-serum response factor) gene family. This factor, which we have named MEF2C, binds specifically to the MEF2 element and activates transcription via this element. Specific isoforms of this factor are found exclusively in brain and are robustly expressed by neurons in cerebral cortex. In situ hybridization indicates that the factor is expressed preferentially in certain neuronal layers of cortex and that expression declines during postnatal development. The unusual pattern of expression in brain suggests that this transcription factor may be important in the development of cortical architecture.

Comparison of three methods for estimating the number of entomopathogenic nematodes present in soil samples

Numbers of Steinernema sp. (CB2B) and S. carpocapsae (Agriotos) exponentially declined after application into a clay loam soil. Over a 35-day sampling period, Steinernema sp. (CB2B) was more persistent than S. carpocapsae (Agriotos). The presence or absence of the second-stage cuticle on the third-stage juveniles (J3) at the time of application did not alter the rate of population decline of Steinernema sp. (CB2B). Nearly all J3 of Steinernema sp. (CB2B) and S. carpocapsae (Agriotos) lost their cuticle within 24 hours of being in soil. Centrifugal flotation recovered the greatest number of nematodes, with a lower variance than either the live bait or Baermann funnel techniques. A strong positive linear relationship was evident between numbers of nematodes present in the soil and the numbers that established in a bait insect. Approximately 40% of Steinernema sp. (CB2B) and 30% of the S. carpocapsae (Agriotos) present in the soil established in Galleria mellonella larvae. The extraction techniques had different efficiencies and gave different relative estimates of persistence for the two species. Persistence and infectivity was best measured using a combination of live bait and flotation techniques.

Effects of maternal obesity on fasting metabolism in newborn rats

Maternal obesity is a risk factor for subsequent fasting hypoglycemia in human infants after birth. To investigate further this problem, we employed an animal model of obesity to study neonatal extrauterine metabolic adaptations in pups of obese and lean rats. Female Sprague-Dawley rats were fed a 'cafeteria diet' to induce obesity prior to and during pregnancy. Prior to mating, the cafeteria fed rats were significantly heavier (449 v. 345 g, P less than 0.001) than the controls. Furthermore, weight gain during pregnancy and weight at term were also significantly greater in the obese rats even though they consumed less food during pregnancy. Pup weights and the number of pups per litter were similar between the two groups. Pups born to obese mothers demonstrated hypoglycemia after being fasted for 150 and 180 min when compared with control pups. Hepatic glycogen stores were increased in the fetus of pups born to obese mothers. Glycogen content in pups born to obese mothers declined minimally after birth and remained greater than hepatic glycogen values in control pups throughout the study. In addition to increased fetal storage of glycogen, fetal hepatic triglyceride content was augmented in pups of obese rats. These triglyceride stores declined and were mobilized during fasting after birth. In contrast, hepatic triglyceride content increased after birth among control rats. These results suggest that maternal obesity results in augmented fetal hepatic tissue stores of both glycogen and triglycerides. Hypoglycemia among pups of excessively obese mothers may be due to attenuated mobilization of hepatic glycogen.(ABSTRACT TRUNCATED AT 250 WORDS)

Relationship of substrate level to turnover rate in fasted adult and newborn dogs

Glucose turnover, clearance and response to insulin were determined in fasted newborn and adult dogs. Fasting levels of glucose and insulin and rates of glucose turnover and clearance were not different between the two groups. Blood glucose correlated with basal glucose turnover in newborn pups but not in adult dogs. Glucose turnover was not related to fasting plasma insulin levels. Glucose clearance was an inverse function of blood glucose levels among newborn but not adult dogs. Glucose clearance and blood glucose levels were not related to insulin concentrations. In response to euglycemic hyperinsulinemia, glucose metabolism increased 4-fold among adults but only 1.7-fold in pups. Hyperglycemic hyperinsulinemia increased glucose metabolism in both groups but to a much greater extent in the pups. Euglycemic hyperinsulinemia increased the metabolic clearance rate of glucose 4.2-fold among adults but only 1.8-fold in newborn dogs. In response to hyperglycemic hyperinsulinemia glucose clearance rates were now similar. Despite euglycemic hyperinsulinemia, the newborn dog had an attenuated response to insulin, demonstrating lower rates of glucose metabolism and glucose clearance. The response to the hyperglycemic stimuli suggests that maximal glucose uptake was not achieved during hyperinsulinemia alone. This response supports the concept of glucose-mediated regulation of glucose disposal in newborn animals.

Plasma kinetics of parenteral tocopherol in premature infants

The potential use of alpha-tocopherol (alpha-T) in the prevention of retrolental fibroplasia led to a study of the plasma kinetics of alpha-T. A dose of 20 mg alpha-tocopherol acetate (alpha-T-Ac) was injected subcutaneously in 5 premature newborns. alpha-T-Ac and alpha-T were assayed by high-pressure liquid chromatography. The maximum plasma concentration of alpha-T-Ac was 2.0 +/- 0.60 mg/dl (mean +/- SEM). alpha-T concentrations remained above 0.5 mg/dl from 8 to 168 h with a mean peak plasma concentration of 2.15 +/- 0.45 mg/dl. alpha-T-Ac absorption and elimination half-lives were 7.0 +/- 0.7 and 23.2 +/- 9.0 h, respectively; alpha-T appearance and elimination half-lives were 12.8 +/- 3.1 and 80.6 +/- 21.0 h. The proposed dosage to keep a plasma level higher than 0.5 mg/dl is 20 mg of alpha-T-Ac every 5 days.