Childhood Maltreatment and Immune Cell Gene Regulation during Adolescence: Transcriptomics Highlight Non-Classical Monocytes

Childhood maltreatment has been repeatedly linked to a higher incidence of health conditions with an underlying proinflammatory component, such as asthma, chronic obstructive pulmonary disease, stroke, and cardiovascular disease. Childhood maltreatment has also been linked to elevated systemic inflammation prior to the onset of disease. However, childhood maltreatment is highly comorbid with other risk factors which have also been linked to inflammation, namely major depression. The present analysis addresses this issue by assessing the association of maltreatment with genome-wide transcriptional profiling of immune cells collected from four orthogonal groups of adolescents (aged 13-17): maltreated and not maltreated in childhood, with and without major depressive disorder. Maltreatment and psychiatric history were determined using semi-structured clinical interviews and cross-validated using self-report questionnaires. Dried whole blood spots were collected from each participant (n = 133) and assayed to determine the extent to which maltreatment in childhood was associated with a higher prevalence of transcriptional activity among differentially expressed genes, specific immune cell subtypes, and up- or down-regulation of genes involved in immune function after accounting for current major depression. Maltreatment was associated with increased interferon regulatory factor (IRF) transcriptional activity (p = 0.03), as well as nuclear factor erythroid-2 related factor 1 (NRF1; p = 0.002) and MAF (p = 0.01) among up-regulated genes, and increased activity of nuclear factor kappa beta (NF-κB) among down-regulated genes (p = 0.01). Non-classical CD16+ monocytes were implicated in both the up- and down-regulated genes among maltreated adolescents. These data provide convergent evidence supporting the role of maltreatment in altering intracellular and molecular markers of immune function, as well as implicate monocyte/macrophage functions as mechanisms through which childhood maltreatment may shape lifelong immune development and function.

The endoscope and the radiofrequency unit in DCR surgery

Endoscopic laser-assisted dacryocystorhinostomy (DCR) offers several advantages over standard external (SE) DCR. The technique eliminates the cutaneous scar and cosmetic blemish of an external dissection and causes less surgical trauma and bleeding than SE-DCR, with shortened postoperative recovery time and lessened postoperative pain. However, the equipment is expensive. We modified this technique using simple instruments such as the curette, Kerrison punch, Freer elevator, Storz endoscope, Ellman Surgitron unit, and the Javate DCR electrodes instead of the laser. Fifty patients with epiphora and nasolacrimal obstruction underwent surgery with our new technique. Fifty age-matched, paired external DCR were performed, and comparisons were made with the endoscopic procedure described. If preoperative epiphora was resolved and nasolacrimal patency was confirmed by lacrimal irrigation 3 months after tube removal, the operation was considered a success. The study attained a 90% success rate for endoscopic radiofrequency-assisted DCR, as compared to a 94% success rate (p > 0.05, not statistically significant) for the SE-DCR.

A comparison of antimicrobial activity of ofloxacin, L-ofloxacin, and other oral agents for respiratory pathogens

The attainable inhibitory ratios (AR) for oral antibiotics were calculated by using literature reports of concentrations attained in respiratory secretions for amoxicillin-clavulanic acid (AMX/CA), ofloxacin (OFL), L-ofloxacin (L-OFL), cefuroxime (CEFU), ciprofloxacin (CIP), and enoxacin (ENO), and using microdilution minimum inhibitory concentration data of these antimicrobials against the common bacterial respiratory pathogens. AR of each antibiotic against the pathogens was expressed as multiples of the MICs achieved at the respiratory site. Bacteria tested included Staphylococcus aureus, group-A and group-B streptococci, Viridans streptococci, Streptococcus pneumoniae, Brahamella catarrhalis, Klebsiella pneumoniae, Eikenella corrodens, Haemophilus influenzae, H. parainfluenzae, Pseudomonas aeruginosa, and Legionella pneumophila. The antimicrobials with the narrowest spectrum of activity were amoxicillin-clavulanic acid and cefuroxime which had high attainable inhibitory ratios only against Gram-positive cocci. Ofloxacin and L-oflaxacin were among the quinolones with the highest overall ARs against respiratory pathogen, including, L. pneumophila, H. influenzae, and B. catarrhalis. All agents showed no, or inadequately low ARs for P. aeruginosa.

Bactericidal effects of antibiotics on slowly growing and nongrowing bacteria

Antimicrobial agents are most often tested against bacteria in the log phase of multiplication to produce the maximum bactericidal effect. In an infection, bacteria may multiply less optimally. We examined the effects of several classes of antimicrobial agents to determine their actions on gram-positive and gram-negative bacteria during nongrowing and slowly growing phases. Only ciprofloxacin and ofloxacin exhibited bactericidal activity against nongrowing gram-negative bacteria, and no antibiotics were bactericidal (3-order-of-magnitude killing) against Staphylococcus aureus. For the very slowly growing gram-negative bacteria studied, gentamicin (an aminoglycoside), imipenem (a carbapenem), meropenem (a carbapenem), ciprofloxacin (a fluoroquinolone), and ofloxacin (a fluoroquinolone) exhibited up to 5.7 orders of magnitude more killing than piperacillin or cefotaxime. This is in contrast to optimally growing bacteria, in which a wide variety of antibiotic classes produced 99.9% killing. For the gram-positive and gram-negative bacteria we examined, antibiotic killing was greatly dependent on the growth rate. The clinical implications of slow killing by chemotherapeutic agents for established bacterial infections and infections involving foreign bodies are unknown.

An in-vitro and in-vivo comparison of the activity of beta-lactamase inhibitor combinations with imipenem and cephalosporins against Escherichia coli producing TEM-1 or TEM-2 beta-lactamase

Reference strains of Escherichia coli (ampicillin-susceptible and -resistant ATCC strains, and known TEM-1 and TEM-2 beta-lactamase producers) were tested in vitro and in the in-vivo mouse thigh infection model against four beta-lactamase inhibitor compounds (BICs: amoxycillin/clavulanic acid, ampicillin/sulbactam, ticarcillin/clavulanic acid, and piperacillin/tazobactam), selected cephalosporins, and imipenem. The ATCC strains (ampicillin-susceptible and -resistant) were susceptible to the BICs in disc and MIC tests. Three or more logs of killing were observed at the NCCLS breakpoint concentrations. However, the TEM-1 and TEM-2 producers were resistant in disc tests to ampicillin/sulbactam and amoxycillin/clavulanic acid, and showed intermediate susceptibility to ticarcillin/clavulanic acid. MICs were at or near the breakpoint, but bactericidal activity was only noted at the probable breakpoint concentration of piperacillin/tazobactam. Cefoxitin, cefotaxime, cefpirome and imipenem, but not cephalothin, showed greater bactericidal activity and lower MICs for the TEM-producing strains than the BICs. The viable count of the TEM-1 producer was not reduced in the mouse thigh model by ampicillin/sulbactam or amoxycillin/clavulanic acid, but cefpirome and cefotaxime reduced the viable count by approximately three logs. There was a 50% mortality rate in mice receiving the two BICs. The ampicillin-susceptible ATCC strain of E. coli was killed to a similar degree by all agents tested. Overall, the BICs appeared inferior, in both in-vivo and in-vitro tests to selected cephalosporins and imipenem when tested against reference strains of E. coli producing TEM-1 or TEM-2 beta-lactamase. The large inoculum effect and poor bactericidal activity observed with the BICs suggest they could be less effective in certain clinical situations.

Evaluation of two methods for overcoming the antibiotic carry-over effect

The antibiotic carry-over effect occurs when antibiotic transferred onto the agar plate with the subcultured aliquot is sufficient to inhibit the growth of viable bacteria, and results in a falsely low MBC. This phenomenon was eliminated by widely streaking the transferred aliquot over at least one half of a 100 mm agar plate or by centrifugation and resuspension of the organisms in non-antibiotic-containing media prior to plating. Both methods require more effort than the current method of MBC determination, but can be performed in clinical laboratories and are thus highly recommended in the testing of organisms from endocarditis and meningitis patients.