Analysis of polyhexamethylene biguanide and alexidine in contact lens solutions using capillary electrophoresis, ultra-performance liquid chromatography and quadrupole time of flight mass spectrometry.

Polymeric biguanides, as well as quaternary ammonium compounds, are ubiquitous antimicrobial agents in healthcare. Due to the highly cationic and polymeric nature of these compounds and the complex matrices in which they are found, the analytical characterization of products containing them remains challenging. In this work an efficient, sensitive, and high-resolution separation protocol was developed to perform quantitative measurements (sub-mg L-1) of alexidine dihydrochloride (ADH) and polyhexamethylene biguanide (PHMB) in commercial multipurpose contact lens solutions (MPS). Initially, contactless conductivity (C4D) detection was explored, but lacked adequate selectivity and sensitivity to quantify PHMB or ADH in commercial MPS. To overcome these limitations, an alternative approach using solid phase extraction (SPE) followed by separation with reversed phase ultra-performance liquid chromatography (RP-UPLC) was developed for both ADH and PHMB separation and detection. The most sensitive and reliable method investigated utilized standard additions to compensate for matrix effects. For ADH, concentration values measured with the presented method were consistent with data provided by the MPS manufacturer (1.6 mg L-1) within 0.10 mg L-1. PHMB quantification in MPS products was successful at concentrations <1 mg L-1 with quantitative reproducibility better than 2% RSD. Comparison of blind sample testing using the RP-UPLC method showed strong correlation (R2 = 0.939) of PHMB concentrations with results obtained by the United States Food and Drug Administration using a published HPLC-Evaporative light scattering detection (ELSD) assay. A significant advantage of this method is the ability to partially resolve PHMB polydispersity, which to date has been minimally studied and explained. By coupling with electrospray mass spectrometry (MS), a general trend was observed for increased retention as a function of PHMB chain length. The improved robustness and reproducibility of UV detection versus ELSD coupled with the superior resolving power of UPLC is an asset to the detection and characterization of PHMB and ADH. In addition to quality control of MPS, this method has potential application to the analyses skin wipes, wound dressings and other medical products where understanding how manufacturing processes lead to differences in polydispersity is important to maximize the antimicrobial properties while minimizing toxicologic effects.

Growth of the pectoral girdle in a sample of juveniles from the kellis 2 cemetery, Dakhleh Oasis, Egypt.

OBJECTIVES: This study investigates growth patterns in the scapula and clavicle in a cross-sectional juvenile skeletal sample ranging from 20 weeks gestation to 8.5 years of age from the Kellis 2 cemetery, Dakhleh Oasis, Egypt. The primary goal is to quantify growth patterns and growth velocities in the scapula and clavicle to better understand the development of the pectoral girdle. METHODS: A series of low-order polynomial regression models was used to examine growth curves in clavicle diaphyseal length, scapular height, and scapular width. Incremental growth and relative percent increase were examined among successive age groups as a proxy measure of growth velocity. Scapular body proportions were assessed with the scapular index and compared across age groups using a Kruskal-Wallis test with post-hoc tests. RESULTS: A third-order polynomial best describes growth in clavicle diaphyseal length and scapular height, and a second-order polynomial best describes growth in scapular width. Growth velocity patterns are similar among clavicle diaphyseal length, scapular height, and scapular width particularly from birth until the end of early childhood. Clavicle diaphyseal length decelerates during middle childhood while scapular height and width accelerate during this time. With increasing age, the scapular body proportionately increases more in height than in width. The relatively narrow scapular body characteristic of adult scapulae is first evident during early childhood. CONCLUSIONS: Changes in scapular body shape during ontogeny may be a reflection of the greater alterations taking place in the integrated morphology of the pectoral girdle during the biomechanical shift from crawling to bipedalism. Am. J. Hum. Biol. 28:636-645, 2016. © 2016 Wiley Periodicals, Inc.

Synthesis of cis-[Cr(diimine)2(1-methylimidazole)2](3+) Complexes and an Investigation of Their Interaction with Mononucleotides and Polynucleotides.

A protocol is presented for the synthesis of chromium(III) complexes of the type cis-[Cr(diimine)2(1-methylimidazole)2](3+). These compounds exhibit large excited-state oxidizing powers and strong luminescence in solution. Emission is quenched by added guanine, yielding rate constants that track the driving force for guanine oxidation. The cis-[Cr(TMP)(DPPZ)(1-MeImid)2](3+) species binds strongly to duplex DNA with a preference for AT base sites in the minor groove and may serve as a precursor for photoactivated DNA covalent adduct formation.

Ten-atom silver cluster signaling and tempering DNA hybridization.

Silver clusters with ∼10 atoms are molecules, and specific species develop within DNA strands. These molecular metals have sparsely organized electronic states with distinctive visible and near-infrared spectra that vary with cluster size, oxidation, and shape. These small molecules also act as DNA adducts and coordinate with their DNA hosts. We investigated these characteristics using a specific cluster-DNA conjugate with the goal of developing a sensitive and selective biosensor. The silver cluster has a single violet absorption band (λ(max) = 400 nm), and its single-stranded DNA host has two domains that stabilize this cluster and hybridize with target oligonucleotides. These target analytes transform the weakly emissive violet cluster to a new chromophore with blue-green absorption (λ(max) = 490 nm) and strong green emission (λ(max) = 550 nm). Our studies consider the synthesis, cluster size, and DNA structure of the precursor violet cluster-DNA complex. This species preferentially forms with relatively low amounts of Ag(+), high concentrations of the oxidizing agent O2, and DNA strands with ≳20 nucleotides. The resulting aqueous and gaseous forms of this chromophore have 10 silvers that coalesce into a single cluster. This molecule is not only a chromophore but also an adduct that coordinates multiple nucleobases. Large-scale DNA conformational changes are manifested in a 20% smaller hydrodynamic radius and disrupted nucleobase stacking. Multidentate coordination also stabilizes the single-stranded DNA and thereby inhibits hybridization with target complements. These observations suggest that the silver cluster-DNA conjugate acts like a molecular beacon but is distinguished because the cluster chromophore not only sensitively signals target analytes but also stringently discriminates against analogous competing analytes.

Comparative outcomes of different endovenous thermal ablation systems on great and small saphenous vein insufficiency: Long-term results.

BACKGROUND AND OBJECTIVE: This study examined the outcomes of over a decade of endovenous thermal ablation (EVTA) treatments for great and small saphenous vein (GSV and SSV) insufficiency, utilizing three different endovenous thermal ablation systems. MATERIALS AND METHODS: This retrospective study reviewed EVTA treatments performed at an outpatient clinic (MDLSVI) from April 1999 to February 2013. Systems included 810 nm diode (hemoglobin targeting), 1,320 nm laser (water targeting) and a radiofrequency (direct thermal transfer) (RF) device. Clinical and ultrasonographic evaluation were performed before treatment and at each follow-up visit. Patients were examined yearly by Duplex ultrasonography. Success was defined as complete absence of reflux. RESULTS: Analysis of 934 treatments demonstrated that although recanalization could occur over time, endovenous ablation has a very high success rate. Ablation rates were 92.5%, 85.9%, and 71.9% at 6-months, 1-year, and 5-years after procedures. Recanalization occurred in 156 out of 934 treatments (16.7%) during the follow-up period. Among three difference systems, the total ablation success rate was significantly different (P < 0.001). The 1,320 nm Nd:YAG laser (n = 502) provided the highest ablation rate compared to the radiofrequency (n = 398) and 810 nm diode (n = 34) throughout their follow-up period, which were 8, 13, and 9 years, respectively. At 1-year follow-up, successful ablation rates of RF, 810 nm, and 1,320 nm were 78.2%, 80.8%, and 93.7%, respectively. At 5-year follow-up, successful ablation rates of RF, 810 nm, and 1,320 nm were 61.7%, 65.7%, and 84.7%, respectively. CONCLUSION: EVTA is very effective for ablation of the GSV and SSV. Complete ablation varied significantly among different systems with water targeting 1,320 nm providing the highest incidence saphenous vein ablation. This remained durable at 8-year follow-up by Duplex ultrasound.

Ontogenetic changes in intralimb proportions in a Romano-Christian period sample from the Dakhleh Oasis, Egypt.

OBJECTIVES: The purpose of this study is to document the appearance of adult patterns in intralimb indices during ontogeny in a skeletal sample from the Kellis 2 cemetery, Dakhleh Oasis, Egypt. In addition, this study explores evolvability in intralimb indices to understand relative differences in sensitivity to ecogeographic variables. METHODS: Brachial and crural indices were compared across age cohorts with Welch's ANOVA tests and post-hoc Dunnett-Tukey-Kramer (DTK) pairwise multiple comparison tests. Spearman's rank correlation coefficients were used to examine developmental conservation and evolvability in intralimb proportions. RESULTS: Brachial and crural indices are greatest in the fetus/perinate cohort as compared to all other cohorts, decrease during infancy and early childhood, and increase during middle/late childhood. The adult pattern in the brachial index is first evident in infancy, but is not maintained throughout development. Conversely, the adult pattern in the crural index appears during early childhood and is maintained throughout development. The brachial index shows a higher degree of evolvability than the crural index in utero. CONCLUSIONS: The shifting pattern in intralimb proportions during development in the Kellis 2 sample is similar to that previously reported from globally diverse samples, which likely reflects the differential growth acceleration of proximal and distal intralimb skeletal elements during ontogeny. The brachial index may be more responsive to climatic conditions while the crural index may be more conserved due to functional demands. The data indicate that Kellis 2 juveniles were under strong selective pressures from climatic factors.

An exploration of adult body shape and limb proportions at Kellis 2, Dakhleh Oasis, Egypt.

Several studies have shown that the human body generally conforms to the ecogeographical expectations of Bergmann's and Allen's rules; however, recent evidence suggests that these expectations may not hold completely for some populations. Egypt is located at the crossroads of Sub-Saharan Africa, Southern Europe, and the Near East, and gene flow among groups in these regions may confound ecogeographical patterning. In this study, we test the fit of the adult physique of a large sample (N = 163) of females and males from the Kellis 2 cemetery (Dakhleh Oasis, Egypt) against ecogeographical predictions. Body shape (i.e., body mass relative to stature) was assessed by the femur head diameter to bicondylar femur length index (FHD/BFL), and brachial and crural indices were calculated to examine intralimb proportions. Body shape in the Kellis 2 sample is not significantly different from high-latitude groups and a Lower Nubian sample, and intralimb proportions are not significantly different from mid-latitude and other low-latitude groups. This study demonstrates the potential uniqueness of body shape and intralimb proportions in an ancient Egyptian sample, and further highlights the complex relationship between ecogeographic patterning and adaptation.

Shattered lives and broken childhoods: Evidence of physical child abuse in ancient Egypt.

Much can be learned about cultural attitudes of violence towards children from the analyses of their skeletal remains and mortuary patterns of the communities in which they lived and died. A bioarchaeological approach integrating biological, socio-cultural, and physical environments is used in analyzing the remains of a 2-3-year-old child from Kellis 2, a Romano-Christian period cemetery in the Dakhleh Oasis, Egypt. The skeletal remains of this individual show an unusual pattern of trauma and healing events, possibly indicating multiple episodes of non-accidental trauma. Macroscopic, radiographic, and histologic analyses show the extent of the skeletal trauma and healing, while stable carbon and nitrogen analyses of bone and hair reveal metabolic disturbances and changes in diet correlated with these traumatic events. Results from the differential diagnosis demonstrate that this individual exhibits skeletal fracture and healing patterns consistent with repeated non-accidental trauma, which may or may not have resulted in death. In addition, this individual may also represent the earliest documented case of violence against children from an archaeological context.

Effect of ancillary ligands on the DNA interaction of [Cr(diimine)3]3+ complexes containing the intercalating dipyridophenazine ligand.

The synthesis of photoluminescent Cr(III) complexes of the type [Cr(diimine)(2)(DPPZ)](3+) are described, where DPPZ is the intercalating dipyridophenazine ligand, and diimine corresponds to the ancillary ligands bpy, phen, DMP, and TMP (where bpy = 2,2'-bipyridine, phen = 1,10-phenanthroline, DMP = 5,6-dimethyl-1,10-phenanthroline, and TMP = 3,4,7,8-tetramethyl-1,10-phenanthroline). For TMP, DMP, and phen as ancillary ligands, the complexes have also been resolved into their Lambda and Delta optical isomers. A comparison of the photophysical and electrochemical properties reveal similar (2)E(g) --> (4)A(2g) (O(h)) emission wavelengths and lifetimes, and a variation of 110 mV in the (2)E(g) excited state oxidizing power. A detailed investigation has been undertaken of ancillary ligand effects on the DNA binding of these complexes with a range of polynucleotides. For all four complexes, emission is quenched by the addition of calf thymus B-DNA, with the emission lifetime data yielding bimolecular quenching rate constants close to the diffusion controlled limit. Equilibrium dialysis studies have established a general predilection for AT base binding sites, while companion experiments with added distamycin (a selective minor groove binder) provide evidence for a minor groove binding preference. For the case of [Cr(TMP)(2)(DPPZ)](3+), concomitant equilibrium dialysis and circular dichroism measurements have demonstrated very strong enantioselective binding by the Lambda optical isomer. The thermodynamics of DNA binding have also been explored via isothermal titration calorimetry (ITC). The ITC data establish that the primary binding mode for all four Cr(III) complexes is entropically driven, a result that is attributed to the highly favorable free energy contribution associated with the hydrophobic transfer of the Cr(III) complexes from solution into the DNA binding site.