Euphorbia plant latex is inhabited by diverse microbial communities.

Premise Of The Study: The antimicrobial properties and toxicity of Euphorbia plant latex should make it a hostile environment to microbes. However, when specimens from Euphorbia spp. were propagated in tissue culture, microbial growth was observed routinely, raising the question whether the latex of this diverse plant genus can be a niche for polymicrobial communities.

An intravaginal ring for the sustained delivery of tenofovir disoproxil fumarate.

Recent clinical trials have demonstrated that pre-exposure prophylaxis (PrEP) may prevent HIV infection in a significant number of HIV-1 negative individuals in venerable populations; however, trial efficacy has been highly variable, with notable successes and failures. Poor adherence to PrEP regimens has been implicated as a primary factor in determining efficacy of these trials. With the exception of CAPRISA 004 where use of a pericoital tenofovir gel led to a 39% reduction in HIV infection, all successful PrEP regimens to date have used the fumarate salt of the tenofovir disoproxil ester prodrug of tenofovir (TDF) alone or in combination with emtricitabine (FTC).

Pharmacokinetics of long-acting tenofovir alafenamide (GS-7340) subdermal implant for HIV prophylaxis.

Oral or topical daily administration of antiretroviral (ARV) drugs to HIV-1-negative individuals in vulnerable populations is a promising strategy for HIV-1 prevention. Adherence to the dosing regimen has emerged as a critical factor determining efficacy outcomes of clinical trials. Because adherence to therapy is inversely related to the dosing period, sustained release or long-acting ARV formulations hold significant promise for increasing the effectiveness of HIV-1 preexposure prophylaxis (PrEP) by reducing dosing frequency.

Pharmacokinetics of injectable, long-acting nevirapine for HIV prophylaxis in breastfeeding infants.

Mother-to-child transmission (MTCT) of HIV-1 remains a global health problem. The World Health Organization (WHO) recommendations advise the administration of a once-daily, oral, prophylactic regimen of the nonnucleoside reverse transcriptase inhibitor nevirapine (NVP) from birth until 4 to 6 weeks of age for infants born to HIV-infected mothers in regions without access to safe and nutritionally adequate alternatives to breast milk. A critical factor driving the successful implementation of the WHO guidelines involves sustaining high adherence to the frequent dosing.

An intravaginal ring for the sustained delivery of antibodies.

Human monoclonal antibodies (mAbs) based on IgG and IgA have shown promise as topical microbicide candidates to protect women from HIV infection. Application of mAbs has been limited, however, by the inability of vaginal gels and conventional intravaginal ring (IVR) designs, the predominant vaginal product formulations, to effectively deliver biomolecules in a coitally independent fashion with retention of bioactivity. We have developed a novel pod-IVR platform that delivers ovine IgG (ov-IgG) as a model for IgG and IgA human mAbs.

Beta- lactam antibiotics stimulate biofilm formation in non-typeable haemophilus influenzae by up-regulating carbohydrate metabolism.

Non-typeable Haemophilus influenzae (NTHi) is a common acute otitis media pathogen, with an incidence that is increased by previous antibiotic treatment. NTHi is also an emerging causative agent of other chronic infections in humans, some linked to morbidity, and all of which impose substantial treatment costs. In this study we explore the possibility that antibiotic exposure may stimulate biofilm formation by NTHi bacteria.

Death and transfiguration in static Staphylococcus epidermidis cultures.

The overwhelming majority of bacteria live in slime embedded microbial communities termed biofilms, which are typically adherent to a surface. However, when several Staphylococcus epidermidis strains were cultivated in static liquid cultures, macroscopic aggregates were seen floating within the broth and also sedimented at the test tube bottom. Light- and electron microscopy revealed that early-stage aggregates consisted of bacteria and extracellular matrix, organized in sheet-like structures.

Pharmacokinetics and preliminary safety study of pod-intravaginal rings delivering antiretroviral combinations for HIV prophylaxis in a macaque model.

Preexposure prophylaxis using oral regimens involving the HIV nucleoside reverse transcriptase inhibitors tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC) demonstrated efficacy in three clinical trials. Adherence was determined to be a key parameter for success. Incorporation of the TDF-FTC combination into intravaginal rings (IVRs) for sustained mucosal delivery could increase product adherence and efficacy compared with those of oral and vaginal gel formulations.

Isolation of PCR quality microbial community DNA from heavily contaminated environments.

Asphalts, biochemically degraded oil, contain persistent, water-soluble compounds that pose a significant challenge to the isolation of PCR quality DNA. The adaptation of existing DNA purification protocols and commercial kits proved unsuccessful at overcoming this hurdle. Treatment of aqueous asphalt extracts with a polyamide resin afforded genomic microbial DNA templates that could readily be amplified by PCR.

Cultivated vaginal microbiomes alter HIV-1 infection and antiretroviral efficacy in colonized epithelial multilayer cultures.

There is a pressing need for modeling of the symbiotic and at times dysbiotic relationship established between bacterial microbiomes and human mucosal surfaces. In particular clinical studies have indicated that the complex vaginal microbiome (VMB) contributes to the protection against sexually-transmitted pathogens including the life-threatening human immunodeficiency virus (HIV-1). The human microbiome project has substantially increased our understanding of the complex bacterial communities in the vagina however, as is the case for most microbiomes, very few of the community member species have been successfully cultivated in the laboratory limiting the types of studies that can be completed.

Experimental approaches to investigating the vaginal biofilm microbiome.

Unraveling the complex ecology of the vaginal biofilm microbiome relies on a number of complementary techniques. Here, we describe the experimental approaches for studying vaginal microbial biofilm samples with a focus on specimen preparation for subsequent analysis. The techniques include fluorescence microscopy, fluorescence in situ hybridization, and scanning and transmission electron microscopy.

Sustained delivery of commensal bacteria from pod-intravaginal rings.

Topical administration of live commensal bacteria to the vaginal tract holds significant potential as a cost-effective strategy for the treatment of sexually transmitted infections and the delivery of mucosal vaccines. Probiotic-releasing intravaginal rings (IVRs) embody significant theoretical advantages over traditional daily-dosage forms, such as sustained and controlled delivery leading to improved adherence to therapy compared to that of frequent dosing. The conventional IVR designs, however, are not amenable to the delivery of live bacteria.

Comparison of the vaginal microbial communities in women with recurrent genital HSV receiving acyclovir intravaginal rings.

Vaginally administered antiviral agents may reduce the risk of HIV and HSV acquisition. Delivery of these drugs using intravaginal rings (IVRs) holds the potential benefits of improving adherence and decreasing systemic exposure, while maintaining steady-state drug levels in the vaginal tract. Elucidating how IVRs interact with the vaginal microbiome constitutes a critical step in evaluating the safety of these devices, as shifts the vaginal microbiome have been linked with several disease states.

Global expression of molecular transporters in the human vaginal tract: implications for HIV chemoprophylaxis.

Background: Pre-exposure chemoprophylaxis (PrECP) using antiretroviral agents is a promising strategy for the prevention of sexual HIV transmission in women. Molecular transporters in the human vaginal tract (VT) may play a pivotal role in determining drug disposition and, consequently, pharmacodynamic outcomes in these efforts. Little is known, however, on the expression of these transporters in vaginal tissues, representing a critical knowledge gap.

Pharmacokinetics of a multipurpose pod-intravaginal ring simultaneously delivering five drugs in an ovine model.

Multipurpose technologies that simultaneously protect from sexually transmitted infections and unintended pregnancy are urgently needed. Pod-intravaginal rings (IVRs) formulated with the antiretroviral agents (ARVs) tenofovir, nevirapine, and saquinavir and the contraceptives etonogestrel and estradiol were evaluated in sheep. Steady-state concentrations were maintained for 28 days with controlled, sustained delivery.

Safety and pharmacokinetics of intravaginal rings delivering tenofovir in pig-tailed macaques.

Antiretroviral-based microbicides applied topically to the vagina may play an important role in protecting women from HIV infection. Incorporation of the nucleoside reverse transcriptase inhibitor tenofovir (TFV) into intravaginal rings (IVRs) for sustained mucosal delivery may lead to increased microbicide product adherence and efficacy compared with those of conventional vaginal formulations. Formulations of a novel "pod IVR" platform spanning a range of IVR drug loadings and daily release rates of TFV were evaluated in a pig-tailed macaque model.

An intravaginal ring for the simultaneous delivery of multiple drugs.

Intravaginal delivery of microbicide combinations is a promising approach for the prevention of sexually transmitted infections, but requires a method of providing simultaneous, independent release of multiple agents into the vaginal compartment. A novel intravaginal ring (IVR) platform has been developed for simultaneous delivery of the reverse-transcriptase inhibitor tenofovir (TFV) and the guanosine analogue antiviral acyclovir (ACV) with independent control of release rate for each drug. The IVR is based on a pod design, with up to 10 individual polymer-coated drug cores embedded in the ring releasing through preformed delivery channels.

Tenofovir and tenofovir disoproxil fumarate pharmacokinetics from intravaginal rings.

Objectives: To compare the distribution of tenofovir in sheep vaginal lumen, tissue, and plasma following topical delivery of the antiretroviral drug from intravaginal rings, either as tenofovir or the disoproxil fumarate prodrug.

Design: Comparative pharmacokinetic study in sheep.

Method: Intravaginal rings formulated to achieve equivalent release rates of tenofovir and its disoproxil fumarate prodrug were evaluated for 28 days in sheep, with four animals in each group.

Simultaneous delivery of tenofovir and acyclovir via an intravaginal ring.

Vaginal microbicides may play an important role in protecting women from HIV infection. A strong synergy between HSV and HIV has been observed, and epidemiological studies demonstrate that HSV infection increases the risk of HIV acquisition. Incorporation of the antiretroviral tenofovir (TFV) along with the antiherpetic acyclovir (ACV) into combination intravaginal rings (IVRs) for sustained mucosal delivery of both compounds could lead to increased microbicide product adherence and efficacy compared with conventional vaginal formulations.

Microbial biofilms on the surface of intravaginal rings worn in non-human primates.

Millions of intravaginal rings (IVRs) are used by women worldwide for contraception and for the treatment of vaginal atrophy. These devices also are suitable for local and systemic sustained release drug delivery, notably for antiviral agents in human immunodeficiency virus pre-exposure prophylaxis. Despite the widespread use of IVRs, no studies have examined whether surface-attached bacterial biofilms develop in vivo, an important consideration when determining the safety of these devices.

Characterization of structures in biofilms formed by a Pseudomonas fluorescens isolated from soil.

Background: Microbial biofilms represent an incompletely understood, but fundamental mode of bacterial growth. These sessile communities typically consist of stratified, morphologically-distinct layers of extracellular material, where numerous metabolic processes occur simultaneously in close proximity. Limited reports on environmental isolates have revealed highly ordered, three-dimensional organization of the extracellular matrix, which may hold important implications for biofilm physiology in vivo.

Determination of phosphate/arsenate by a modified molybdenum blue method and reduction of arsenate by S(2)O(4)(2-).

A modified molybdenum blue method for fast and accurate measurement of arsenate and phosphate in aqueous solution at concentrations below 10mumoll(-1) is reported. The modification consists of optimizing the composition of the molybdenum-containing solution (potassium antimony tartrate, ammonium molybdate, sulfuric acid). Selective reduction of arsenate by sodium dithionite is used to determine phosphate concentrations, and for the speciation of arsenate and arsenite, in an aqueous mixture according to the scheme developed by Johnston and Pilson.

Hydrogen cyanide exhaust emissions from in-use motor vehicles.

Motor vehicle exhaust emissions are known to contain hydrogen cyanide (HCN), but emission rate data are scarce and, in the case of idling vehicles, date back over 20 years. For the first time, vehicular HCN exhaust emissions from a modern, in-use fleet at idle have been measured. The 14 tested light duty motor vehicles were operating at idle as these conditions are associated with the highest risk exposure scenarios (i.

Non-invasive measurement of cardiac output: evaluation of new infrared absorption spectrometer.

The mass spectrometer (MS) traditionally has been the instrument of choice for measuring cardiac output (Q (T)) non-invasively using the foreign gas uptake method. However, the size and cost of the MS has hampered widespread adoption of this technique outside of the laboratory. Here, we present results, from six normal human subjects at rest and during exercise, of simultaneous Q (T) measurements by an MS and a new, portable infrared (IR) device developed in our laboratories.