Validation of key sponge symbiont pathways using genome-centric metatranscriptomics.

The sponge microbiome underpins host function through provision and recycling of essential nutrients in a nutrient poor environment. Genomic data suggest that carbohydrate degradation, carbon fixation, nitrogen metabolism, sulphur metabolism and supplementation of B-vitamins are central microbial functions. However, validation beyond the genomic potential of sponge symbiont pathways is rarely explored. To evaluate metagenomic predictions, we sequenced the metagenomes and metatranscriptomes of three common coral reef sponges: Ircinia ramosa, Ircinia microconulosa and Phyllospongia foliascens. Multiple carbohydrate active enzymes were expressed by Poribacteria, Bacteroidota and Cyanobacteria symbionts, suggesting these lineages have a central role in assimilating dissolved organic matter. Expression of entire pathways for carbon fixation and multiple sulphur compound transformations were observed in all sponges. Gene expression for anaerobic nitrogen metabolism (denitrification and nitrate reduction) were more common than aerobic metabolism (nitrification), where only the I. ramosa microbiome expressed the nitrification pathway. Finally, while expression of the biosynthetic pathways for B-vitamins was common, the expression of additional transporter genes was far more limited. Overall, we highlight consistencies and disparities between metagenomic and metatranscriptomic results when inferring microbial activity, while uncovering new microbial taxa that contribute to the health of their sponge host via nutrient exchange.

Fluoroquinolone Efficacy against Tuberculosis Is Driven by Penetration into Lesions and Activity against Resident Bacterial Populations.

Fluoroquinolones represent the pillar of multidrug-resistant tuberculosis (MDR-TB) treatment, with moxifloxacin, levofloxacin, or gatifloxacin being prescribed to MDR-TB patients. Recently, several clinical trials of "universal" drug regimens, aiming to treat drug-susceptible and drug-resistant TB, have included a fluoroquinolone. In the absence of clinical data comparing their side-by-side efficacies in controlled MDR-TB trials, a pharmacological rationale is needed to guide the selection of the most efficacious fluoroquinolone. The present studies were designed to test the hypothesis that fluoroquinolone concentrations (pharmacokinetics) and activity (pharmacodynamics) at the site of infection are better predictors of efficacy than the plasma concentrations and potency measured in standard growth inhibition assays and are better suited to determinations of whether one of the fluoroquinolones outperforms the others in rabbits with active TB. We first measured the penetration of these fluoroquinolones in lung lesion compartments, and their potency against bacterial populations that reside in each compartment, to compute lesion-centric pharmacokinetic-pharmacodynamic (PK/PD) parameters. PK modeling methods were used to quantify drug penetration from plasma to tissues at human-equivalent doses. On the basis of these metrics, moxifloxacin emerged with a clear advantage, whereas plasma-based PK/PD favored levofloxacin (the ranges of the plasma AUC/MIC ratio [i.e., the area under the concentration-time curve over 24 h in the steady state divided by the MIC] are 46 to 86 for moxifloxacin and 74 to 258 for levofloxacin). A comparative efficacy trial in the rabbit model of active TB demonstrated the superiority of moxifloxacin in reducing bacterial burden at the lesion level and in sterilizing cellular and necrotic lesions. Collectively, these results show that PK/PD data obtained at the site of infection represent an adequate predictor of drug efficacy against TB and constitute the baseline required to explore synergies, antagonism, and drug-drug interactions in fluoroquinolone-containing regimens.

Nanostructured Aptamer-Functionalized Black Phosphorus Sensing Platform for Label-Free Detection of Myoglobin, a Cardiovascular Disease Biomarker.

We report the electrochemical detection of the redox active cardiac biomarker myoglobin (Mb) using aptamer-functionalized black phosphorus nanostructured electrodes by measuring direct electron transfer. The as-synthesized few-layer black phosphorus nanosheets have been functionalized with poly-l-lysine (PLL) to facilitate binding with generated anti-Mb DNA aptamers on nanostructured electrodes. This aptasensor platform has a record-low detection limit (∼0.524 pg mL(-1)) and sensitivity (36 µA pg(-1) mL cm(-2)) toward Mb with a dynamic response range from 1 pg mL(-1) to 16 µg mL(-1) for Mb in serum samples. This strategy opens up avenues to bedside technologies for multiplexed diagnosis of cardiovascular diseases in complex human samples.

High Systemic Exposure of Pyrazinoic Acid Has Limited Antituberculosis Activity in Murine and Rabbit Models of Tuberculosis.

Pyrazinamide (PZA) is a prodrug requiring conversion to pyrazinoic acid (POA) by an amidase encoded by pncA for in vitro activity. Mutation of pncA is the most common cause of PZA resistance in clinical isolates. To determine whether the systemic delivery of POA or host-mediated conversion of PZA to POA could circumvent such resistance, we evaluated the efficacy of orally administered and host-derived POA in vivo Dose-ranging plasma and intrapulmonary POA pharmacokinetics and the efficacy of oral POA or PZA treatment against PZA-susceptible tuberculosis were determined in BALB/c and C3HeB/FeJ mice. The activity of host-derived POA was assessed in rabbits infected with a pncA-null mutant and treated with PZA. Median plasma POA values for the area under the concentration-time curve from 0 h to infinity (AUC0-∞) were 139 to 222 µg·h/ml and 178 to 287 µg·h/ml after doses of PZA and POA of 150 mg/kg of body weight, respectively, in mice. Epithelial lining fluid POA concentrations in infected mice were comparable after POA and PZA administration. In chronically infected BALB/c mice, PZA at 150 mg/kg reduced lung CFU counts by >2 log10 after 4 weeks. POA was effective only at 450 mg/kg, which reduced lung CFU counts by ∼0.7 log10 POA had no demonstrable bactericidal activity in C3HeB/FeJ mice, nor did PZA administered to rabbits infected with a PZA-resistant mutant. Oral POA administration and host-mediated conversion of PZA to POA producing plasma POA exposures comparable to PZA administration was significantly less effective than PZA. These results suggest that the intrabacillary delivery of POA and that producing higher POA concentrations at the site of infection will be more effective strategies for maximizing POA efficacy.

The Effect of Weight Loss on Indigenous Australians with Diabetes: a study of Feasibility, Acceptability and Effectiveness of Laparoscopic Adjustable Gastric Banding.

BACKGROUND/OBJECTIVES: Diabetes and obesity are common and serious health challenges for indigenous people worldwide. The feasibility of achieving substantial weight loss, leading to remission of diabetes, was evaluated in a regional indigenous Australian community. SUBJECTS/METHODS: A prospective cohort study of 30 obese indigenous adults from the Rumbalara Aboriginal Co-operative in Central Victoria was performed. Inclusion criteria included aboriginality, BMI > 30 kg/m(2) and diabetes diagnosed within the last 10 years. Weight loss was achieved using laparoscopic adjustable gastric banding (LAGB). Participants were treated in their community and followed for 2 years. Outcomes were compared with those of non-indigenous Australians from an earlier randomized controlled trial (RCT) using a similar protocol. RESULTS: 30 participants (26 females, mean age 44.6 years; mean BMI 44.3) had LAGB at the regional hospital. Twenty-six participants completed diabetes assessment at 2 years follow-up. They showed diabetes remission (fasting blood glucose < 7.0 mmol/L and haemoglobin A1c (HbA1c) < 6.2 % while off all therapy except metformin) in 20 of the 26 and a mean weight loss (SD) of 26.0 (14) kilograms. Based on intention-to-treat, remission rate was 66 %. Quality of life improved. There was one early event and 12 late adverse events. The outcomes for weight loss and diabetes remission were not different from the LAGB group of the RCT. CONCLUSIONS: For obese indigenous people with diabetes, a regionalized model of care centred on the LAGB is an effective approach to a serious health problem. The model proved feasible and acceptable to the indigenous people. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (ACTRN 12609000319279).

Phosphodiesterase 4 inhibition reduces innate immunity and improves isoniazid clearance of Mycobacterium tuberculosis in the lungs of infected mice.

Tuberculosis (TB) caused by Mycobacterium tuberculosis (Mtb) is one of the leading infectious disease causes of morbidity and mortality worldwide. Though current antibiotic regimens can cure the disease, treatment requires at least six months of drug therapy. One reason for the long duration of therapy is that the currently available TB drugs were selected for their ability to kill replicating organisms and are less effective against subpopulations of non-replicating persistent bacilli. Evidence from in vitro models of Mtb growth and mouse infection studies suggests that host immunity may provide some of the environmental cues that drive Mtb towards non-replicating persistence. We hypothesized that selective modulation of the host immune response to modify the environmental pressure on the bacilli may result in better bacterial clearance during TB treatment. For this proof of principal study, we compared bacillary clearance from the lungs of Mtb-infected mice treated with the anti-TB drug isoniazid (INH) in the presence and absence of an immunomodulatory phosphodiesterase 4 inhibitor (PDE4i), CC-3052. The effects of CC-3052 on host global gene expression, induction of cytokines, and T cell activation in the lungs of infected mice were evaluated. We show that CC-3052 modulates the innate immune response without causing generalized immune suppression. Immune modulation combined with INH treatment improved bacillary clearance and resulted in smaller granulomas and less lung pathology, compared to treatment with INH alone. This novel strategy of combining anti-TB drugs with an immune modulating molecule, if applied appropriately to patients, may shorten the duration of TB treatment and improve clinical outcome.

Risk factors for a postoperative intraocular pressure spike after phacoemulsification.

BACKGROUND: The aim of our study was to examine several potential risk factors for intraocular pressure (IOP) spikes 2 to 3 hours after phacoemulsification. METHODS: 50 eyes of 50 consecutive patients undergoing uncomplicated phacoemulsification under topical anesthesia were included in this prospective study. The following variables were recorded: preoperative IOP, nuclear colour, cortical lens opacity, posterior subcapsular lens opacity, patient age; and presence or absence of preexisting glaucoma. RESULTS: The mean IOP at each time interval was as follows: preoperatively, 14.5 (SD 3.4) mm Hg; 2-3 hours postoperatively, 23.1 (7.0) mm Hg; and 24 hours postoperatively, 17.0 (6.0) mm Hg. The postoperative IOP was significantly higher than baseline at 2-3 hours (p<0.001) and at 24 hours (p=0.002). Overall there were 10 cases (20%) of IOP spikes 2-3 hours postoperatively. Higher mean baseline IOP was significantly associated with postoperative IOP spikes (p=0.013). Patient age, sex, operating surgeon, absolute phacoemulsification time, lens nuclear colour, cortical opacity, and posterior opacity were not significantly different between groups with or without an IOP spike (p>0.05). INTERPRETATION: Patients with high IOP at the preoperative assessment are more likely to have IOP spikes after surgery and should be scheduled at the start of the operating list. In a day-case setting with restricted opening hours, postoperative checks in those patients at risk of IOP spikes can then coincide with the time IOP reaches its peak.

Visual experiences during vitreous surgery under regional anesthesia: a multicenter study.

PURPOSE: To investigate patients' subjective intraoperative visual experiences during vitreous surgery performed under regional anesthesia, to ascertain if patients were frightened by their visual experiences, and to determine the risk factors associated with a frightening visual experience. DESIGN: Multicenter, prospective study. METHODS: Sixty-five patients who had vitreous surgery under regional (retrobulbar or peribulbar) anesthesia in five centers in Ireland, Singapore, and Hong Kong were interviewed within 2 hours of their operation using a standardized questionnaire. RESULTS: Thirty patients (46.2%) perceived light perception throughout the entire operation, 19 patients (29.2%) experienced transient loss of light perception, and 16 patients (24.6%) experienced no light perception throughout the entire duration of the surgery. Nine patients (13.8%) were frightened by their intraoperative visual experiences. Patients who were frightened by their visual experiences were more likely to see color (100%) than those who were not frightened (55.4%) (P = .010). The mean age of the patients who were frightened was lower (51.8 years) compared with those who were not frightened (64.6 years) (P = .003). The mean duration of surgery was longer for patients who were frightened (118.9 minutes) compared with those who were not frightened (91.2 minutes) (P = .047). CONCLUSIONS: Most patients undergoing vitreous surgery under regional anesthesia retained at least light perception intraoperatively. Importantly, 13.8% of patients were frightened by their visual experiences. A younger age, longer duration of surgery, and perception of color were risk factors for a frightening visual experience.

Patient pain during stretching of small pupils in phacoemulsification performed using topical anesthesia.

PURPOSE: To assess the pain experienced by patients with small pupils during pupil stretching in phacoemulsification performed using topical anesthesia. SETTING: Royal Victoria Eye & Ear Hospital and Mater Misericordiae University Hospital, Dublin, Ireland. METHODS: This was a prospective study that included 26 eyes with small pupils requiring mechanical pupil stretching during phacoemulsification cataract surgery performed under topical anesthesia without sedation. RESULTS: The mean pain score for the instillation of anesthetic drops (2.02) was higher than the mean pain score for the pupil stretch (1.63), but this difference was not significant (signed rank test = -32; P = .2738). There was no significant correlation between the duration of surgery and the overall pain score (r = 0.345; P = .08). There was no significant correlation between change in pupil size and either the pupil stretch score (r = -0.069; P = .74) or the overall pain score (r = -0.032; P = .8739). CONCLUSIONS: Pupil stretching during phacoemulsification in patients with small pupils was performed with minimal patient-reported pain using topical anesthesia. Stretching small pupils with a mechanical device during phacoemulsification performed under topical anesthesia was a safe procedure and did not result in significant patient discomfort.

Changes in the microvascular architecture of colorectal liver metastases following the administration of SMANCS/lipiodol.

BACKGROUND: Liver metastases are the major cause of death for patients with colorectal cancer. Surgical resection is at present the only curative option. Styrene maleic acid neocarzinostatin [SMANCS/Lipiodol (S/L)] targets the unique vascular architecture of tumor blood vessels, which are hyperpermeable and lack a well-developed lymphatic system. Here we report changes in the microvascular architecture of liver metastases by scanning electron microscopy (SEM) following the administration of S/L. MATERIALS AND METHODS: Liver metastases were induced by the intrasplenic injection of dimethylhydrazine induced colon cancer cells in mice. In this model tumor angiogenesis occurs at day 10, while exponential tumor growth occurs at day 16. Changes in the tumor microvasculature were observed at 3 weeks following treatment with S/L at these time points by SEM of corrosion casts. RESULTS: Tumors treated with S/L at day 10 appear similar to day 10 controls. Tumor vessels, 50 +/- 18 microm in diameter, are easily identified from hepatic vessels. Within the hepatic sinusoids are avascular spaces, 144 +/- 60 microm in diameter, which correspond to tumor cell aggregates at the initial stages of growth. Similarly, day 16 treated tumors appear comparable to day 16 controls. These vessels are narrower (84 +/- 32 microm vs. 150 +/- 70 microm) than their control counterparts. This is in contrast to vessels (216 +/- 36 microm in diameter) of a complex nature at 3 weeks. CONCLUSIONS: S/L exerts a marked and immediate effect on the tumor microvessels at both the angiogenic and the exponential phases of tumor growth. This agent is effective at the microvascular level during inhibition of metastatic growth.