Biomechanical comparison of one pin versus two pin fixation in a canine tibial tuberosity avulsion fracture model.

OBJECTIVE: To determine whether one larger or two smaller diameter pins used for tibial tuberosity avulsion fracture (TTAF) stabilization provides greater axial tensile strength and stiffness when subjected to monotonic mechanical load to failure in normal skeletally mature canine cadavers. STUDY DESIGN: Paired ex vivo biomechanical study. SAMPLE POPULATION: Eleven pairs of adult cadaveric dog tibias. METHODS: Twenty-two tibias from 11 dogs were collected to model a TTAF. Each limb of a pair was randomly assigned a one or two-pin fixation. Tibias were subjected to monotonic, axial load to failure. Fixation stiffness, strength, and pin insertion angles were analyzed with parametric testing. Significance was set at p < .05. RESULTS: The mean strength of the single-pin fixation was 426.2 ± 50.5 N compared to two-pin fixation at 639.2 ± 173.5 N (p = .003). The mean stiffness of the single-pin fixation was 57.3 ± 18.7 N/mm and the two-pin fixation was 71.7 ± 20.5 N/mm (p = .029). The normalized ratio between one and two-pin fixation had a mean stiffness of 68% ± 25.8% and strength of 82.8% ± 24.6%. CONCLUSIONS: In an ex vivo cadaveric TTAF model, vertically aligned two-pin fixation offers greater strength and stiffness when compared to a single-pin fixation. CLINICAL SIGNIFICANCE: When repairing TTAF, surgeons should aim to apply two vertically aligned pins rather than a single pin for greater strength and stiffness.

Biology, immature stages, and systematics of snail-killing flies of the genus Colobaea (Diptera: Sciomyzidae), with overviews of aspects of the tribe Sciomyzini.

All reared larvae of flies of the genus Colobaea Zetterstedt, 1837 (Diptera: Sciomyzidae), which comprises 15 valid species, kill and consume freshwater nonoperculate pulmonate snails. New data are presented on the geographic distribution, biology, morphology of immature stages, and classification of Colobaea. Life cycle information is provided from field data and laboratory rearings for four of the 11 Palearctic species-C. bifasciella (Fallén), C. deemingi Knutson Bratt n.sp., C. pectoralis (Zetterstedt), and C. punctata (Lundbeck)-and for one of the three Nearctic species, C. americana Steyskal. Colobaea bifasciella is shown to be one of the most highly specialized parasitoid Sciomyzini, laying eggs on shells of Galba truncatula (O.F. Müller) and Stagnicola palustris (O.F. Müller) in temporary, intermittent, or vernal semiterrestrial situations. Each larva feeds in only one host snail, which is not killed until shortly before the larva completes development. Puparia are strongly modified to fit tightly within the shell of the host. The other reared species are shown to be less specialized than C. bifasciella, with eggs being laid upon vegetation, the larvae behaving as parasitoids-predators-saprophages of exposed aquatic snails, and the puparia of all four species being adapted to a lesser degree than C. bifasciella to fitting within the shell of the host snail. In nature, C. americana attacks Gyraulus parvus (Say) and Physa Draparnaud sp.; C. pectoralis attacks Anisus vortex (L.) and Bathyomphalus contortus (L.); and C. punctata attacks Gyraulus albus O.F. Müller, Lymnaea "peregra," Planorbarius corneus (L.), and Planorbis planorbis (L.). In the laboratory, these species also attacked and consumed other freshwater nonoperculate snails; C. deemingi was reared on Gyraulus intermixtus (Mousson) and Radix gedrosiana (Say), and an adult fly of the Palearctic C. distincta (Meigen) emerged from a puparium found in the shell of Anisus spirorbis (L.) collected in nature. Described and figured are eggs, larvae of all three instars, and puparia of the five laboratory-reared species. To provide perspective on features of Colobaea, diagnostic features are summarized of the immature stages of the Sciomyzini and the suprageneric categories of Sciomyzidae. The biogeography of the tribe Sciomyzini is presented, along with details of known geographical distribution. The classification and phylogenetic position of Colobaea are discussed. Included are a checklist of all known taxa of Colobaea, maps of geographic distribution, and a key to adults of the 15 valid species.

Comprehensive taxonomic, faunistic, biological, and geographic inventory and analysis of the Sciomyzidae (Diptera: Acalyptratae) of the Delmarva region and nearby states in eastern North America.

Genera and species of Sciomyzidae known from the Delmarva region (Delaware, the District of Columbia, Maryland, Virginia, and West Virginia) and nearby states are reviewed taxonomically, faunistically, biologically, and geographically. Although restricted to the taxa in that area, this work amounts to a revision of the sciomyzid fauna of that portion of the Nearctic region. Treated are 91 species in 19 genera, i.e. 46% of the 199 species and all but four of the 23 genera of Sciomyzidae known from the Nearctic Region. Included are 67 species in 16 genera from Delmarva and 24 other species in 10 genera from nearby states. Euthycera flavescens (Loew) is resurrected; Renocera cressoni Mathis and Knutson sp. nov. is described from eastern North America; R. amanda Cresson is given new status as a junior synonym of R. longipes (Loew); and Chaetomacera brevis Cresson, R. cyathiformis Melander, R. pacifica Curran, and R. bergi Steyskal are given new status as junior synonyms of R. striata (Meigen). Newly diagnosed are taxonomic categories ranging from family to species level, including the first diagnoses of abdomens of females of many species, where known. Provided for each genus and species are annotated taxonomic/nomenclatorial catalogs of all North American references to all species, with generic combinations noted, with previously unrecorded synonymies as well as North American literature references, illustrations, and information on natural history and morphology of immature stages. Results of cross-mating studies of Dictya are reported and discussed. Provided are label data from examined specimens, lists of Canadian provinces and U.S. states from which reviewed species have been recorded, and detailed maps of geographical distribution of species in Delmarva, with references to previously published maps.

The Snail-killing Flies (Diptera: Sciomyzidae) of West Africa.

A review of the West African "snail-killing flies" or "marsh flies" (Sciomyzidae) shows that the fauna is not as dominated by the generally aquatic, predaceous genus Sepedon as was previously considered. Twenty species in seven genera, including three new species, Colobaea occidentalis, Pteromicra zariae and Sepedonella castanea are recorded. The Holarctic-Oriental genera Colobaea and Pteromicra are documented from Africa south of the Sahara for the first time. Biogeographical analyses based on the discovery of "Palaearctic" genera of Diptera south of the Sahara, faunal connections, and dispersal routes are presented. A key for identification and illustrations of diagnostic characters for some species are included.

Comparison of bacterial 16S rRNA variable regions for microbiome surveys of ticks.

Ticks vector diverse pathogenic bacteria that are important to identify in public health and veterinary contexts. Technological advances in high throughput sequencing have given an unprecedented opportunity to comprehensively characterize bacterial associates of ticks, but recent studies have used different 16S rRNA variable regions and sequence read lengths with little consideration of whether they reveal the same bacterial diversity. We compare the effectiveness of bacterial surveys using three library preparations across nine 16S variable regions and a set of 12 tick specimens (Acari: Ixodidae). We identify the bacterial assemblages present in extractions from wild-collected Ixodes scapularis from two regions of Canada, and provide the first microbiome survey for Ixodes angustus. Four bacterial families accounted for most diversity, with Rickettsiaceae being replaced as most common by Enterobacteriaceae or Pseudomonadaceae in some I. scapularis, and Francisellaceae being most abundant in I. angustus. The commercially available Ion 16S kit, based on 6 amplicons representing 16S regions V2, V3, V4, V67, V8 and V9, gave the most comprehensive estimates of bacterial families, with the Ion V4 amplicon generally giving the highest estimated diversity. Sequencing of the V4 amplicon by the MR DNA commercial service also provided cost effective assays of tick microbiomes that were within the range of results from the Ion 16S kit. Subtraction of the number of reads found in an extraction control sample lowered estimates of the number of bacterial families by approximately half. Our study shows that diversity patterns obtained from 16S microbiome surveys depend on the amplicon and protocol used, demonstrating that more than one marker region is needed to provide reliable inferences.

Attitude of doctors towards mentally ill in Hyderabad, India: Results of a prospective survey.

BACKGROUND: Wide prevalence of mental illness has been documented in South India; however, the magnitude of stigma is unclear. AIMS: The aim was to investigate the magnitude of stigma prevalent among medical professionals in Hyderabad, India. MATERIALS AND METHODS: A prospective survey of seven common psychiatric disorders for eight specified perceptions was conducted. Responses of 226 out of 250 (90%) doctors were analyzed. RESULTS: Significant overall negative perception (P < 0.001), with drug addiction (52.8%) and alcoholism (48.2%) eliciting most negative perceptions (Chi-square: P <0.05) was observed. Significant negative perceptions were also seen among married doctors and those with < 10 years experience. Even though, there was no overall difference based on gender (P = 0.242), more females had significant negative perception toward eating disorders, depression, dementia, alcoholism and schizophrenic patients (P ≤ 0.05). CONCLUSIONS: This study revealed negative attitude of doctors toward mentally ill and highlighted the gender difference in perceptions.

The unilateral deep inferior epigastric perforator flap: comparing university to community hospital.

The deep inferior epigastric perforator (DIEP) flap is considered to be the gold standard for autologous breast reconstruction. This study evaluates the outcome of unilateral DIEP flap reconstructions, comparing university with a community hospital setting. A total of 77 unilateral DIEP flaps were performed at one university hospital and two community hospitals by the same two surgeons. Outcome parameters were: hospital stay, operating time, wound infection, wound dehiscence, fat necrosis, haematoma, (partial) flap necrosis and the need for surgical intervention. Forty-nine unilateral DIEP flaps were performed in the university hospital and 28 in the community hospitals. Baseline characteristics were equal. No significant difference was found in total complication rate, flap loss or need for surgical intervention. Although wound dehiscence occurred more often in the community hospitals, unilateral DIEP flap breast reconstructions can be performed with a comparable degree of safety and complication risk in both university and community hospital settings.

Effectiveness of LANAP over time as measured by tooth loss.

This study examines the effectiveness of the laser-assisted new attachment procedure (LANAP) as measured by tooth loss, comparing data to published studies using conventional surgical treatment modalities for the primary treatment of Types III and IV periodontitis. Retrospective data from 107 patients presenting with Types III and IV periodontitis were gathered and evaluated. All patients received LANAP periodontal therapy as their primary surgical treatment according to the FDA-cleared LANAP protocol. The patients averaged 6.2 years post-treatment. The data were compared to several published studies for outcome classification and tooth loss over time. The effectiveness of LANAP as a primary treatment method for Types III and IV periodontitis compares very favorably with conventional surgical treatment modalities concerning tooth loss and stability over time, need for surgical retreatment, and outcome classification. Dentistry continues to develop less invasive means of providing patient care without sacrificing results. Less invasive treatment of periodontitis, with reduced postoperative morbidity yet equal results in tooth retention over time is an important goal. LANAP treatment for moderate and advanced periodontitis provides a less invasive treatment alternative for the dentist and patient to consider as a part of informed consent.

Key aspects of the biology of snail-killing Sciomyzidae flies.

The biology of snail-killing flies (Diptera: Sciomyzidae) has been studied intensively over the past half-century, especially over the past decade. Today, sciomyzids are biologically the best-known group of higher Diptera. The overarching research objectives are evaluation of sciomyzids as biocontrols of disease-carrying or agriculturally important snails and slugs and as a paradigm group for the study of the evolution of diverse feeding and associated behaviors in flies. We present reviews and analyses of some key features of particular scientific and societal interest, including behavioral and phenological groups; laboratory experimental studies on behavior and development; population biology, bioindicators, ecosystem service provision, and conservation; phylogenetics, molecular studies, and evolutionary biology; and biocontrol.

Progress and challenges in numerically modelling solid sports balls with application to softballs.

Much of the work surrounding finite element simulation of bat-ball impacts has focused on techniques describing the ball. Determining the accuracy of these models has been hindered by challenges in experimentally characterizing the ball's response. In the following, dynamic mechanical analysis and an instrumented impact test were used to characterize the solid ball at deformation rates representative of play. The ball was described in the numerical model as a linear viscoelastic material. It was observed that a Prony series model based on small deformation dynamic mechanical analysis did not provide sufficient energy loss upon impact, while a simpler Power Law model, fitted to large deformation data, described the measured energy loss and impact force over a range of speeds. Results of a parametric study are presented as a guide towards tailoring the parameters of the Power Law model to match the measured energy loss and impact force. Discrepancies observed between the experiment and the numerical model suggest that the ball response should be characterized in environments closely resembling game conditions.

Drosophila ABC transporter mutants white, brown and scarlet have altered contents and distribution of biogenic amines in the brain.

Monoamines such as dopamine, histamine and serotonin (5-HT) are widely distributed throughout the brain of the fruit fly Drosophila melanogaster, where many of their actions have been investigated. For example, histamine is released from photoreceptor synapses in the lamina neuropile of the visual system. Mutations of the genes white, an important eye pigmentation marker in fly genetics that encodes an ABC transporter, and its binding partner brown, cause neural phenotypes not readily reconciled solely with actions in eye pigmentation. We find that flies mutant for these genes, and another binding partner, scarlet, have about half the wild-type amount of histamine in the head, as well as reduced 5-HT and dopamine. These differences parallel reductions in immunoreactivity to the corresponding biogenic amines. They also correlate with the amine content of fractions after differential centrifugation of head homogenates. Thus, most of the amine is found in the vesicle-rich fraction of wild-type head homogenates, whereas it is found in the supernatant fractions from white, brown and scarlet flies. White co-expresses in lamina epithelial glia with Ebony, which conjugates histamine to beta-alanine. Histamine is then released when the conjugate is hydrolyzed in photoreceptors, by Tan. Mutant white ameliorates the effects of tan on head histamine whereas it exacerbates the effects of ebony. Our results are consistent with the proposal that histamine uptake by the epithelial glia may be white dependent. Behavioral abnormalities in white, brown and scarlet mutants could arise because aminergic neurons in the Drosophila brain have reduced amine for release.

Biological monitoring of uranium exposure in south central Virginia.

In May 2004, two groundwater wells in Dinwiddie County, Virginia were found to have natural uranium levels either at or above the EPA recommended limit of 30 microg/l. As a result, a stop drinking water advisory was issued until a water treatment system could be installed to remove the uranium. In response to residents' concerns, and uncertainty of exposures, affected individuals were asked to participate in a voluntary epidemiological investigation of uranium uptake and 1-year uranium retention study. This study had two primary objectives: quantification of the uranium load on the participants, as expressed by their urine uranium concentration, and retention after 1 year of no exposure. A first-morning void urine specimen, along with survey information, was collected from 156 participants in May 2004, with a second collection occurring 12 months later of 91 participants. The samples were analyzed for uranium by ICP/MS, pH, creatinine by the Jaffe method, and RBP by LIA after both collections. A reduction of one order of magnitude for the geometric mean urine uranium concentration was observed, from 0.100 microg/g creatinine to 0.011 microg/g creatinine in 1 year. Comparatively, NHANES has reported that the geometric mean for all participants, ages 6 years and older, is 0.008 microg/g creatinine, with the 95th percentile being 0.040 microg/g creatinine. None of the second round specimens showed a urine uranium concentration higher than baseline for an individual.

Synthesis and evaluation of an intercalator-polyamide hairpin designed to target the inverted CCAAT box 2 in the topoisomerase IIalpha promoter.

The synthesis and DNA-binding properties of a novel naphthalimide-polyamide hairpin (3) designed to target the inverted CCAAT box 2 (ICB2) site on the topoisomerase IIalpha (topoIIalpha) promoter are described. The polyamide component of 3 was derived from the minor-groove binder, 2, and tailored to bind to the 5'-TTGGT sequence found in and flanking ICB2. The propensity of mitonafide 4 to intercalate between G-C base pairs was exploited by the incorporation of a naphthalimide moiety at the N terminus of 2. Hybrid 3 targeted 5'-CGATTGGT and covered eight contiguous base pairs, which included the underlined ICB2 site. DNase I footprinting analysis with the topoIIalpha promoter sequence demonstrated that 3 bound selectively to the ICB2 and ICB3 sites. Thermal-denaturation studies confirmed these results, and the highest degree of stabilization was found for ICB2 and -3 in preference to ICB1 (4.1, 4.6, and 0.6 degrees C, respectively). CD studies confirmed minor-groove binding and suggested a 1:1 binding stoichiometry. Emission-titration experiments established intercalative binding. Surface plasmon resonance results showed strong binding to ICB2 (2.5x10(7) M(-1)) with no observable binding to ICB1. Furthermore, the binding constant of 3 to ICB2 was larger than that of the parent polyamide 2. The increased binding affinity was primarily due to a reduction in the dissociation-rate constant of the polyamide-DNA complex, which can be attributed to the N-terminal naphthalimide moiety. In addition, the binding site of 3 was larger than that of 2, which innately improved sequence selectivity. We conclude that the polyamide-naphthalimide 3 selectively binds to the ICB2 site by simultaneous intercalation and minor-groove binding, and warrants further investigation as a model compound for the regulation of topoIIalpha gene expression.

Stereochemistry of guanidine-metal interactions: implications for L-arginine-metal interactions in protein structure and function.

The geometries of 150 guanidine-metal ion interactions retrieved from crystal structures deposited in the Cambridge Structural Database have been analyzed. Metal ions exhibit a preference for anti coordination stereochemistry in the plane of the unprotonated guanidine group, usually in chelate complexes with a diguanidine moiety, but syn-oriented interactions are occasionally found for single guanidine-metal interactions. Three L-arginine-metal coordination interactions are found in metalloenzyme structures deposited in the Protein Data Bank: biotin synthase from E. coli, His-67 --> Arg human carbonic anhydrase I, and inactivated B. caldovelox arginase complexed with L-arginine. In these proteins, L-arginine-metal coordination adopts syn/out-of-plane and anti/in-plane coordination stereochemistry. The implications of these results for L-arginine-metal interactions in protein structure and function are discussed. Although such interactions are rare, this analysis serves as a useful reference point for the growing interest in enzymes containing L-arginine residues that function as general bases or metal ligands.

The role of free flaps in the treatment of persistent scalp osteomyelitis.

OBJECTIVE: To evaluate the efficacy of the combination of an extensive surgical debridement and simultaneous free flap repair in case of troublesome cranial osteomyelitis. METHODS: Five patients with persistent, frontal bone osteomyelitis were treated with surgical debridement of the infected bone and reconstruction with a free flap. In all patients, osteomyelitis occurred after neurosurgical procedures and lasted from 1 to 7 years. A latissimus dorsi muscle flap with a split skin graft has been performed. RESULTS: No flap failure occurred and donor site morbidity was negligible. No signs of osteomyelitis or soft tissue infection were observed during the mean follow-up period of 3.2 years. Furthermore, the contour of the cranium could be preserved without a need for bone grafts or implants. CONCLUSION: In our experience, the combination of an extensive surgical debridement and a free flap transfer is demonstrated to be an effective treatment for "chronic" osteomyelitis of the cranium.

Preservation of rat cremaster muscle microcirculation after prolonged cold storage and transplantation.

BACKGROUND: Microvascular surgery for the reconstruction of complex defects involves an ischemic period, which may cause flap failure as the result of ischemia/reperfusion injury. We assessed the microvascular consequences of rat cremaster muscle transplantation after prolonged periods of cold storage in HTK-Bretschneider solution (HTK). MATERIALS AND METHODS: Cremaster muscle transplantations were performed immediately or after 8 or 24 h of cold storage (4 degrees C) in HTK or saline. Intravital microscopy was used to quantify capillary perfusion and venular leukocyte-endothelium interactions following transplantation. RESULTS: The transplantation procedure itself resulted in 50-65 min of ischemia. After direct transplantation, capillary perfusion was 90% of control. Transplantation after 8 h of cold storage in either HTK or saline did not deteriorate capillary perfusion. When the tissue was stored for 24 h, HTK was superior to saline in preserving capillary perfusion (HTK: 76-83% of control, saline: 30%). Immediate transplantation induced a small increase in leukocyte adhesion. Prolonged cold storage in either fluid resulted in reduced flow velocities (qualitative observations) and edema formation, which hampered quantification of leukocyte-endothelium interactions. CONCLUSIONS: Even after 8 or 24 h of cold storage in HTK, transplantation of rat cremaster muscle was successful with good capillary perfusion. Capillary perfusion was better preserved in HTK than in saline.

A novel achiral seco-amino-cyclopropylindoline (CI) analog of CC-1065 and the duocarmycins: design, synthesis and biological studies.

The design, synthesis and DNA binding properties of a novel achiral and amino-containing seco-cyclopropylindoline analog (seco-amino-CI-TMI, 1) of the duocarmycins are described. Thermal induced DNA cleavage studies on pUC18 DNA revealed compound 1 to preferentially bind in the minor groove and to covalently react with AT-rich sequences, particularly at the underlined adenine-N3 group of 5'-AAAAA(865)-3'. This sequence specificity is similar to adozelesin and CC-1065. Using a 4-day continuous exposure, compound 1 inhibited the growth of K562 human chronic myeloid leukemia cells in culture. Compound 1 has appreciable cytotoxicity (IC50 value of 1.30 microM) relative to compound 2 (0.15 microM), the corresponding racemic and hydroxy-seco-CI-TMI analog. These results indicate that the aminophenethyl chloride group present in compound 1 has similar sequence specific and cytotoxic properties to the hydroxy-containing seco-precursors of CC-1065 and the duocarmycins. Moreover, the results suggest that the chiral center present in the natural products is not absolutely necessary for biological activity. The novel aminophenethyl halide moiety is, therefore, a useful template from which to develop future achiral analogs of CC-1065 and the duocarmycins.

Laser-assisted new attachment procedure in private practice.

Three private dental practices conducted a retrospective analysis of patients receiving the laser-assisted new attachment procedure (LANAP). Retrospective results were compared to clinical trial data from the University of Texas Health Sciences Center in San Antonio (UTHSCSA) to determine if outcomes from a controlled clinical trial can be duplicated in private practice. Results also are compared with published results of other surgical and nonsurgical therapies for inflammatory periodontal disease.

Genomic imprinting in Drosophila is maintained by the products of Suppressor of variegation and trithorax group, but not Polycomb group, genes.

Genomic imprinting is a form of epigenetic inheritance that is characterized by differential expression of a gene depending on its parental origin. The mini-X chromosome Dp(1;f)LJ9 in Drosophila shows this type of classical imprinting; when transmitted by the maternal parent genes on this chromosome are fully expressed, but when the chromosome is transmitted by the male parent at least three genes are subject to silencing, resulting in a variegated expression pattern. Chemical and environmental modifiers of position-effect variegation have been shown to alter the somatic maintenance of the imprint. To extend these observations, several mutations in chromatin-associated proteins were examined for their effect on imprinting on the Dp(1;f)LJ9 mini-X chromosome. Effects on establishment and maintenance were independently assessed by genetically associating the mutations in chromatin modifiers with the mini-X chromosome in either the parents, where the imprint is established, or the progeny, in which the imprint must be maintained. Nine Suppressor of variegation [ Su(var)] mutations, including alleles of the Su(var)2-5 gene, which encodes the well characterized heterochromatin-associated protein HP1, abolished maintenance but not the establishment of the imprint. Mutant alleles of two genes in the trithorax group ( trx-G), brahma and trithorax, showed a maternal-effect enhancement of the paternal imprint. Surprisingly, however, with the exception of an Enhancer of Polycomb [ E(Pc)] allele, none of the Polycomb-group ( Pc-G) mutations tested affected the imprint. Thus, the maintenance of this imprint relies on the wild-type products of Su(var) and trx-G, but not Pc-G, genes. Finally, none of the mutations tested affected the maintenance of the maternal imprint or the establishment of either the maternal or paternal imprint, suggesting that the maternal and paternal imprints depend on different molecular processes and that imprint establishment and maintenance are independently regulated.

Essential genes in proximal 3L heterochromatin of Drosophila melanogaster.

We have further characterized essential loci within the centric heterochromatin of the left arm of chromosome 3 (3L) of Drosophila melanogaster, using EMS, radiation and P element mutagenesis. We failed to find any new essential genes, a result that suggests a lower-than-average gene density in this region. Mutations affecting expression of the most proximal gene [lethal 1, l1 or l(3)80Fj] act as dominant suppressors of Polycomb (Pc), behavior which is consistent with a putative trithorax group (trx-G) gene. The third gene to the left of the centromere [lethal 3, l3 or l(3)80Fh] is likely to correspond to verthandi (vtd), a known trx-G gene that plays a role in the regulation of hedgehog (hh) expression and signalling. The intervening gene [lethal 2, l2 or l(3)80Fi] is required throughout development, and mutant alleles have interesting phenotypes; in various allelic combinations that survive, we observe fertility, bristle, wing, eye and cuticle defects.