bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of a Novel Gene,wosA, Regulating FlhDC Expression inProteus mirabilis
Authors: Hatt Janet K. , Rather Philip N.
Published: January 2008

In this study, we describewosA, aProteus mirabilisgene identified by its ability to increase swarming motility when overexpressed. At various times during the swarming cycle, the increased expression ofwosAresulted in a 4- to 16-fold upregulation of the transcription offlhDC, encoding the master regulator of the flagellar cascade. In turn, the expression offlaA, encoding flagellin, was substantially increased inwosA-overexpressing strains. The overexpression ofwosAalso resulted in constitutive swarmer cell differentiation in liquid medium, a normally nonpermissive condition. However, inwosA-overexpressing strains, the onset of swarming was not altered. A nullwosAallele resulted in a slight decrease in swarming motility. The expression ofwosAwas growth phase dependent during growth in liquid and on agar plates during swarmer cell differentiation. Increasing the viscosity of liquid medium by the addition of polyvinylpyrrolidone induced swarmer cell differentiation and resulted in a fourfold increase inwosAtranscription. AfliLmutation that results in constitutive swarmer cell elongation also increasedwosAtranscription. In this study, we discuss the possible role of thewosAgene product in signal transduction from solid surfaces to induce swarmer cell differentiation, possibly via alterations in the motor switch complex. This study also suggests that despite constitutive swarmer cell differentiation inwosA-overexpressing strains, there are additional regulatory and/or environmental conditions that may control the onset of swarming migration.
Maintenance Forced by a Restriction-Modification System Can Be Modulated by a Region in Its Modification Enzyme Not Essential for Methyltransferase Activity
Authors: Ohno Satona , Handa Naofumi , Watanabe-Matsui Miki , Takahashi Noriko , Kobayashi Ichizo
Published: January 2008

Several type II restriction-modification gene complexes can force their maintenance on their host bacteria by killing cells that have lost them in a process called postsegregational killing or genetic addiction. It is likely to proceed by dilution of the modification enzyme molecule during rounds of cell division following the gene loss, which exposes unmethylated recognition sites on the newly replicated chromosomes to lethal attack by the remaining restriction enzyme molecules. This process is in apparent contrast to the process of the classical types of postsegregational killing systems, in which built-in metabolic instability of the antitoxin allows release of the toxin for lethal action after the gene loss. In the present study, we characterize a mutant form of the EcoRII gene complex that shows stronger capacity in such maintenance. This phenotype is conferred by an L80P amino acid substitution (T239C nucleotide substitution) mutation in the modification enzyme. This mutant enzyme showed decreased DNA methyltransferase activity at a higher temperature in vivo and in vitro than the nonmutated enzyme, although a deletion mutant lacking the N-terminal 83 amino acids did not lose activity at either of the temperatures tested. Under a condition of inhibited protein synthesis, the activity of the L80P mutant was completely lost at a high temperature. In parallel, the L80P mutant protein disappeared more rapidly than the wild-type protein. These results demonstrate that the capability of a restriction-modification system in forcing maintenance on its host can be modulated by a region of its antitoxin, the modification enzyme, as in the classical postsegregational killing systems.
Genome of the Actinomycete Plant Pathogen
Clavibacter michiganensis
subsp.
sepedonicus
Suggests Recent Niche Adaptation
Authors: Bentley Stephen D. , Corton Craig , Brown Susan E. , Barron Andrew , Clark Louise , Doggett Jon , Harris Barbara , Ormond Doug , Quail Michael A. , May Georgiana , Francis David , Knudson Dennis , Parkhill Julian , Ishimaru Carol A.
Published: January 2008

Clavibacter michiganensis
subsp.
sepedonicus
is a plant-pathogenic bacterium and the causative agent of bacterial ring rot, a devastating agricultural disease under strict quarantine control and zero tolerance in the seed potato industry. This organism appears to be largely restricted to an endophytic lifestyle, proliferating within plant tissues and unable to persist in the absence of plant material. Analysis of the genome sequence of
C. michiganensis
subsp.
sepedonicus
and comparison with the genome sequences of related plant pathogens revealed a dramatic recent evolutionary history. The genome contains 106 insertion sequence elements, which appear to have been active in extensive rearrangement of the chromosome compared to that of
Clavibacter michiganensis
subsp.
michiganensis
. There are 110 pseudogenes with overrepresentation in functions associated with carbohydrate metabolism, transcriptional regulation, and pathogenicity. Genome comparisons also indicated that there is substantial gene content diversity within the species, probably due to differential gene acquisition and loss. These genomic features and evolutionary dating suggest that there was recent adaptation for life in a restricted niche where nutrient diversity and perhaps competition are low, correlated with a reduced ability to exploit previously occupied complex niches outside the plant. Toleration of factors such as multiplication and integration of insertion sequence elements, genome rearrangements, and functional disruption of many genes and operons seems to indicate that there has been general relaxation of selective pressure on a large proportion of the genome.
Critical Role of a Single Position in the −35 Element for Promoter Recognition by
Mycobacterium tuberculosis
SigE and SigH
Authors: Song Taeksun , Song Seung-Eun , Raman Sahadevan , Anaya Mauricio , Husson Robert N.
Published: January 2008

Mycobacterial SigE and SigH both initiate transcription from the
sigB
promoter, suggesting that they recognize similar sequences. Through mutational and primer extension analyses, we determined that SigE and SigH recognize nearly identical promoters, with differences at the 3′ end of the −35 element distinguishing between SigE- and SigH-dependent promoters.
The C-Terminal Extension of Ferrochelatase Is Critical for Enzyme Activity and for Functioning of the Tetrapyrrole Pathway in
Synechocystis
Strain PCC 6803
Authors: Sobotka Roman , McLean Samantha , Zuberova Monika , Hunter C. Neil , Tichy Martin
Published: January 2008

Heme and chlorophyll (Chl) share a common biosynthetic pathway up to the branch point where magnesium chelatase and ferrochelatase (FeCH) insert either magnesium for Chl biosynthesis or ferrous iron for heme biosynthesis. A distinctive feature of FeCHs in cyanobacteria is their C-terminal extension, which forms a putative transmembrane segment containing a Chl-binding motif. We analyzed the ΔH324 strain of
Synechocystis
sp. strain PCC 6803, which contains a truncated FeCH enzyme lacking this C-terminal domain. Truncated FeCH was localized to the membrane fraction, suggesting that the C-terminal domain is not necessary for membrane association of the enzyme. Measurements of enzyme activity and complementation experiments revealed that the ΔH324 mutation dramatically reduced activity of the FeCH, which resulted in highly upregulated 5-aminolevulinic acid synthesis in the ΔH324 mutant, implying a direct role for heme in the regulation of flux through the pathway. Moreover, the ΔH324 mutant accumulated a large amount of protoporphyrin IX, and levels of Chl precursors were also significantly increased, suggesting that some, but not all, of the “extra” flux can be diverted down the Chl branch. Analysis of the recombinant full-length and truncated FeCHs demonstrated that the C-terminal extension is critical for activity of the FeCH and that it is strictly required for oligomerization of this enzyme. The observed changes in tetrapyrrole trafficking and the role of the C terminus in the functioning of FeCH are discussed.
Structural and Functional Characterization of an Organic Hydroperoxide Resistance Protein from
Mycoplasma gallisepticum
Authors: Jenkins Cheryl , Samudrala Ram , Geary Steven J. , Djordjevic Steven P.
Published: January 2008

As obligate parasites,
Mycoplasma
species are continuously exposed to oxidative damage due to host-generated peroxides and reactive oxygen species (ROS). In addition, the production of endogenous oxidants is believed to be a primary virulence mechanism of several Mollicute species, indicating that oxidative stress resistance is crucial to survival of these bacteria in the host milieu. Despite the abundance of oxidants at the site of infection, enzymes responsible for the detoxification of ROS have never been characterized in mycoplasmas. Here we characterize a homolog of the
ohr
(organic hydroperoxide resistance) family from
Mycoplasma gallisepticum
(encoding MGA1142). Unlike previously characterized
ohr
genes, the
mga1142
gene is not upregulated in response to oxidative stress but displays a novel pattern of expression. Both organic and inorganic peroxides can act as substrates for MGA1142, but they are degraded with various efficiencies. Furthermore, cumene hydroperoxide, an aromatic peroxide metabolized with high efficiency by other Ohr proteins, was shown to rapidly inactivate MGA1142, accounting for the sensitivity of
M. gallisepticum
cells to this compound. Comparative modeling of the MGA1142 quaternary structure revealed that the active site of this molecule has a relatively wide conformation. These data indicate that the natural substrate for MGA1142 differs from that for previously characterized Ohr proteins. Triton X-114 partitioning demonstrated that MGA1142 is located in both cytosol and membrane fractions, suggesting that in vivo this molecule plays a role in the detoxification of both endogenous and exogenous peroxides. A model describing how MGA1142 is likely to be oriented in the cell membrane is presented.
The Rcs Phosphorelay Is a Cell Envelope Stress Response Activated by Peptidoglycan Stress and Contributes to Intrinsic Antibiotic Resistance
Authors: Laubacher Mary E. , Ades Sarah E.
Published: January 2008

Gram-negative bacteria possess stress responses to maintain the integrity of the cell envelope. Stress sensors monitor outer membrane permeability, envelope protein folding, and energization of the inner membrane. The systems used by gram-negative bacteria to sense and combat stress resulting from disruption of the peptidoglycan layer are not well characterized. The peptidoglycan layer is a single molecule that completely surrounds the cell and ensures its structural integrity. During cell growth, new peptidoglycan subunits are incorporated into the peptidoglycan layer by a series of enzymes called the penicillin-binding proteins (PBPs). To explore how gram-negative bacteria respond to peptidoglycan stress, global gene expression analysis was used to identifyEscherichia colistress responses activated following inhibition of specific PBPs by the β-lactam antibiotics amdinocillin (mecillinam) and cefsulodin. Inhibition of PBPs with different roles in peptidoglycan synthesis has different consequences for cell morphology and viability, suggesting that not all perturbations to the peptidoglycan layer generate equivalent stresses. We demonstrate that inhibition of different PBPs resulted in both shared and unique stress responses. The regulation of capsular synthesis (Rcs) phosphorelay was activated by inhibition of all PBPs tested. Furthermore, we show that activation of the Rcs phosphorelay increased survival in the presence of these antibiotics, independently of capsule synthesis. Both activation of the phosphorelay and survival required signal transduction via the outer membrane lipoprotein RcsF and the response regulator RcsB. We propose that the Rcs pathway responds to peptidoglycan damage and contributes to the intrinsic resistance ofE. colito β-lactam antibiotics.
Polarity in Archaeal Operon Transcription in
Thermococcus kodakaraensis
Authors: Santangelo Thomas J. , Čuboňová L'ubomíra , Matsumi Rie , Atomi Haruyuki , Imanaka Tadayuki , Reeve John N.
Published: January 2008

An in vivo archaeal gene reporter system has been established based on TK1761, a gene that encodes a nonessential β-glycosidase in
Thermococcus kodakaraensis
. Following the introduction of nonsense codons into promoter-proximal genes, polarity in operon expression in this archaeon has been established by both microarray hybridization assays and a reporter gene expression system.
Clearance of store-released Ca2+by the Na+-Ca2+exchanger is diminished in aortic smooth muscle from Na+-K+-ATPase α2-isoform gene-ablated mice
Authors: Lynch Ronald M. , Weber Craig S. , Nullmeyer Kevin D. , Moore Edwin D. W. , Paul Richard J.
Published: January 2008

Two α-isoforms of the Na+-K+-ATPase are expressed in vascular smooth muscle cells (VSMCs). The α1-isoform is proposed to serve a cytosolic housekeeping role, whereas the α2-isoform modulates Ca2+storage via coupling to the Na+-Ca2+exchanger (NCX) in a subsarcolemmal compartment. To evaluate the ramifications of this proposed interaction, Ca2+-store load and the contributions of the primary Ca2+transporters to Ca2+clearance were studied in aortic VSMCs from embryonic wild-type (WT) and Na+-K+-ATPase α2-isoform gene-ablated, homozygous null knockout (α2-KO) mice. Ca2+stores were unloaded by inhibiting the sarco(endo)plasmic reticulum Ca2+-ATPase with cyclopiazonic acid (CPA) in Ca2+-free media to limit Ca2+influx. Ca2+clearance by the plasma membrane Ca2+-ATPase (PMCA), NCX, or mitochondria was selectively inhibited. In WT VSMCs, NCX accounted for 90% of the Ca2+efflux. In α2-KO VSMCs, preferential clearance of store-released Ca2+by NCX was lost, whereas PMCA activity was increased. Selective inhibition of the α2-isoform (0.5 μM ouabain for 20 min), before treatment with CPA enhanced the store load in VSMCs from WT, but not α2-KO mice. A subsequent analysis of capacitative Ca2+entry (CCE) indicated that the magnitude of Ca2+influx was significantly greater in α2-KO cells. Our findings support the concept of a subsarcolemmal space where the α2-isoform coupled with NCX modulates Ca2+-store function and, thereby, CCE.
Transient receptor potential melastatin 6 and 7 channels, magnesium transport, and vascular biology: implications in hypertension
Authors: Touyz Rhian M.
Published: January 2008

Magnesium, an essential intracellular cation, is critically involved in many biochemical reactions involved in the regulation of vascular tone and integrity. Decreased magnesium concentration has been implicated in altered vascular reactivity, endothelial dysfunction, vascular inflammation, and structural remodeling, processes important in vascular changes and target organ damage associated with hypertension. Until recently, very little was known about mechanisms regulating cellular magnesium homeostasis, and processes controlling transmembrane magnesium transport had been demonstrated only at the functional level. Two cation channels of the transient receptor potential melastatin (TRPM) cation channel family have now been identified as magnesium transporters, TRPM6 and TRPM7. These unique proteins, termed chanzymes because they possess a channel and a kinase domain, are differentially expressed, with TRPM6 being found primarily in epithelial cells and TRPM7 occurring ubiquitously. Vascular TRPM7 is modulated by vasoactive agents, pressure, stretch, and osmotic changes and may be a novel mechanotransducer. In addition to its magnesium transporter function, TRPM7 has been implicated as a signaling kinase involved in vascular smooth muscle cell growth, apoptosis, adhesion, contraction, cytoskeletal organization, and migration, important processes involved in vascular remodeling associated with hypertension and other vascular diseases. Emerging evidence suggests that vascular TRPM7 function may be altered in hypertension. This review discusses the importance of magnesium in vascular biology and implications in hypertension and highlights the transport systems, particularly TRPM6 and TRPM7, which may play a role in the control of vascular magnesium homeostasis. Since the recent identification and characterization of Mg2+-selective transporters, there has been enormous interest in the field. However, there is still a paucity of information, and much research is needed to clarify the exact mechanisms of magnesium regulation in the cardiovascular system and the implications of aberrant transmembrane magnesium transport in the pathogenesis of hypertension and other vascular diseases.
Spontaneous baroreflex control of cardiac output during dynamic exercise, muscle metaboreflex activation, and heart failure
Authors: Ichinose Masashi , Sala-Mercado Javier A. , O'Leary Donal S. , Hammond Robert L. , Coutsos Matthew , Ichinose Tomoko , Pallante Marco , Iellamo Ferdinando
Published: January 2008

We have previously shown that spontaneous baroreflex-induced changes in heart rate (HR) do not always translate into changes in cardiac output (CO) at rest. We have also shown that heart failure (HF) decreases this linkage between changes in HR and CO. Whether dynamic exercise and muscle metaboreflex activation (via imposed reductions in hindlimb blood flow) further alter this translation in normal and HF conditions is unknown. We examined these questions using conscious, chronically instrumented dogs before and after pacing-induced HF during mild and moderate dynamic exercise with and without muscle metaboreflex activation. We measured left ventricular systolic pressure (LVSP), CO, and HR and analyzed the spontaneous HR-LVSP and CO-LVSP relationships. In normal animals, mild exercise significantly decreased HR-LVSP (−3.08 ± 0.5 vs. −5.14 ± 0.6 beats·min−1·mmHg−1; P < 0.05) and CO-LVSP (−134.74 ± 24.5 vs. −208.6 ± 22.2 ml·min−1·mmHg−1; P < 0.05). Moderate exercise further decreased both and, in addition, significantly reduced HR-CO translation (25.9 ± 2.8% vs. 52.3 ± 4.2%; P < 0.05). Muscle metaboreflex activation at both workloads decreased HR-LVSP, whereas it had no significant effect on CO-LVSP and the HR-CO translation. HF significantly decreased HR-LVSP, CO-LVSP, and the HR-CO translation in all situations. We conclude that spontaneous baroreflex HR responses do not always cause changes in CO during exercise. Moreover, muscle metaboreflex activation during mild and moderate dynamic exercise reduces this coupling. In addition, in HF the HR-CO translation also significantly decreases during both workloads and decreases even further with muscle metaboreflex activation.
Protein kinase Cδ regulates endothelial nitric oxide synthase expression via Akt activation and nitric oxide generation
Authors: Sud Neetu , Wedgwood Stephen , Black Stephen M.
Published: January 2008

In this study, we explore the roles of the delta isoform of PKC (PKCδ) in the regulation of endothelial nitric oxide synthase (eNOS) activity in pulmonary arterial endothelial cells isolated from fetal lambs (FPAECs). Pharmacological inhibition of PKCδ with either rottlerin or with the peptide, δV1-1, acutely attenuated NO production, and this was associated with a decrease in phosphorylation of eNOS at Ser1177 (S1177). The chronic effects of PKCδ inhibition using either rottlerin or the overexpression of a dominant negative PKCδ mutant included the downregulation of eNOS gene expression that was manifested by a decrease in both eNOS promoter activity and protein expression after 24 h of treatment. We also found that PKCδ inhibition blunted Akt activation as observed by a reduction in phosphorylated Akt at position Ser473. Thus, we conclude that PKCδ is actively involved in the activation of Akt. To determine the effect of Akt on eNOS signaling, we overexpressed a dominant negative mutant of Akt and determined its effect of NO generation, eNOS expression, and phosphorylation of eNOS at S1177. Our results demonstrated that Akt inhibition was associated with decreased NO production that correlated with reduced phosphorylation of eNOS at S1177, and decreased eNOS promoter activity. We next evaluated the effect of endogenously produced NO on eNOS expression by incubating FPAECs with the eNOS inhibitor 2-ethyl-2-thiopseudourea (ETU). ETU significantly inhibited NO production, eNOS promoter activity, and eNOS protein levels. Together, our data indicate involvement of PKCδ-mediated Akt activation and NO generation in maintaining eNOS expression.
Carbon Nanotubes for Space and Bio-Engineering Applications
Authors: Lau Kin-Tak , Cheung Hoi-Yan , Lu Jian , Yin Yan-Sheng , Hui David , Li Hu-Lin
Published: January 2008

Since the last decade, most research focus in the fields of science and engineering has been dramatically shifted toward the same fashion from the investigation of traditional macroscale properties of materials to their atomic scale level (or called nanoscale). It is believed that the
mechanical, electrical and thermal properties of materials, at their nanoscale level are totally different with that measured at macro and micro scale levels due to an assumption of their perfect atomic architectures, i.e., no-defect among atoms. In such circumstance, the strength of the materials
can therefore reach to their ideal level since the maximal bonding energies among the atoms can be achieved. Recently, numerous researches have been focused on using nanomaterials as reinforcements to strengthen polymer-based composites for space and bio-engineering applications. Carbon nanotubes
are the most common types of nanomaterials that have been used to mix with polymer to form nanocomposites. The nanotubes possess superior mechanical strength and electrical conductivity at specified chiral arrangements for producing high strength conductive polymers. In this paper, a critical
review, based on the works done by authors and other researchers on the properties and applications of the carbon nanotubes for space and bio-engineering applications is given. Their advantages and disadvantages on some particular applications are also discussed in detail.
Carbon Nanotube and Nanostring Like Pitchfork as Molecular Gun
Authors: de Jesus Chaves Neto Antônio Maia , da Silva Mota Gunar Vingre
Published: January 2008

We propose a system which consists of a nanotube probe and the rigid and static nanostring internal like a pitchfork. The simulation was made by classic molecular dynamics with standard parameterization. We calculated thermodynamic properties of these devices as molar specific heat
and entropy variation. These facts could be useful for the construction of new molecular devices against cancer or cholesterol molecules.
Review of Treatment and Complications in 79 Children With Rattlesnake Bite
Authors: Sotelo Norberto
Published: January 2008

Introduction Envenomation by snakebite is a health problem in Mexico.

Objective To review the treatment and complications of rattlesnake bites in 79 children.

Materials and methods The variables studied were age, sex, season, hour, signs, symptoms, and complications during 1977 to 1996 (group I) and 1997 to 2006 (group II). Hospitalization time and antivenom type, including polyvalent equine antiviperin serum and a [F(ab′)2] antivenom (fabotherapic), were also studied. Results. Most incidents (35%) occurred within the perimeter of children's homes and 8.8% took place inside homes; 40.5% of the children were females; and most snakebites occurred during the summer (70.8%). Members of groups I and II received polyvalent equine antiviperin serum and fabotherapy, respectively. Hospitalization time was less in group II members ( P < .0001). The complications in group I members included hypoprothrombinemia and hypofibrinogenemia ( P < .0001).

Conclusions Hospitalization time, complications, and treatment cost were less in patients undergoing fabotherapy.
Pharmacokinetics of Glucarpidase in Subjects With Normal and Impaired Renal Function
Authors: Phillips Marc , Smith William , Balan Guhan , Ward Suzanne
Published: January 2008

Glucarpidase (formerly known as carboxypeptidase G2 or CPG2) is being evaluated for the adjunctive treatment of patients experiencing, or at risk of, methotrexate toxicity attributable to its delayed elimination. Delayed elimination of methotrexate can occur in patients with methotrexate‐induced renal toxicity. In this study, glucarpidase pharmacokinetics were assessed in volunteer subjects with normal (n = 8) and severely impaired (n = 4) renal function. Each subject received a single intravenous dose of glucarpidase 50 U/kg (equivalent to 114.5 1 μ/kg) infused over 5 minutes. The mean maximum serum concentration (Cmax) for glucarpidase in renally impaired subjects was 2.9 μg/mL, the mean half‐life (t1/2) was 10.0 hours, and the mean area under the serum concentration–time curve from time zero to infinity (AUC0‐∞) was 24.5 μgxh/mL. Similar values were found in subjects with normal renal function (mean Cmax3.1 μg/mL, mean t1/29.0 hours, and mean AUC0‐∞23.4 μgxh/mL). The results indicated little effect of renal impairment on the serum pharmacokinetics of glucarpidase.
Third-Party Forgiveness: (Not) Forgiving Your Close Other's Betrayer
Authors: Green Jeffrey D. , Burnette Jeni L. , Davis Jody L.
Published: January 2008

Building on attribution and interdependence theories, two experiments tested the hypothesis that close friends of victims (third parties) are less forgiving than the victims themselves (first parties). In Experiment 1, individuals imagined a scenario in which either their romantic partner or the romantic partner of a close friend committed the identical relationship offense. Third parties were less forgiving than first parties, a phenomenon we termed the third-party forgiveness effect. This effect was mediated by attributions about the perpetrator's intentions and responsibility for the offense. In Experiment 2, first and third parties reported an actual offense and their subsequent unforgiving motivations. The third-party forgiveness effect was replicated and was mediated by commitment to the perpetrator. Perpetrator apology or amends to the victim increased third-party forgiveness. Future third-party research can expand interpersonal forgiveness research beyond the victim-perpetrator dyad.
Selective Attention to Signs of Success: Social Dominance and Early Stage Interpersonal Perception
Authors: Maner Jon K. , DeWall C. Nathan , Gailliot Matthew T.
Published: January 2008

Results from two experiments suggest that observers selectively attend to male, but not female, targets displaying signs of social dominance. Participants overestimated the frequency of dominant men in rapidly presented stimulus arrays (Study 1) and visually fixated on dominant men in an eyetracking experiment (Study 2). When viewing female targets, participants attended to signs of physical attractiveness rather than social dominance. Findings fit with evolutionary models of mating, which imply that dominance and physical attractiveness sometimes tend to be prioritized preferentially in judgments of men versus women, respectively. Findings suggest that sex differences in human mating are observed not only at the level of overt mating preferences and choices but also at early stages of interpersonal perception. This research demonstrates the utility of examining early-in-the-stream social cognition through the functionalist lens of adaptationist thinking.
Designing a Household Survey to Address Seasonality in Child Care Arrangements
Authors: Schmidt Stefanie R. , Wang Kevin H. , Sonenstein Freya L.
Published: January 2008

In household telephone surveys, a long field period may be required to maximize the response rate and achieve adequate sample sizes. However, long field periods can be problematic when measures of seasonally affected behavior are sought. Surveys of child care use are one example because child care arrangements vary by season. Options include varying the questions posed about school-year and summer arrangements or posing retrospective questions about child care use for the school year only. This article evaluates the bias associated with the use of retrospective questions about school-year child care arrangements in the 1999 National Survey of America's Families. The authors find little evidence of bias and hence recommend that future surveys use the retrospective approach.
A Histological and Ultrastructural Evaluation of the Patellar Tendon 10 Years after Reharvesting its Central Third
Authors: Lidén Mattias , Movin Tomas , Ejerhed Lars , Papadogiannakis Nikos , Blomén Eva , Hultenby Kjell , Kartus Jüri
Published: January 2008

Purpose

This study was undertaken to evaluate the histologic and ultrastructural characteristics of the patellar tendon 10 years after reharvesting its central third.

Hypothesis

In the long term, after its central third is reharvested, the patellar tendon does not regain a normal histological and ultrastructural appearance.

Study Design

Case-control study; Level of evidence, 3.

Methods

Twelve consecutive patients (4 women, 8 men) who underwent anterior cruciate ligament revision surgery using reharvested ipsilateral patellar tendon autografts were included in the study. Percutaneous biopsy samples were obtained from the central and lateral parts of the patellar tendon under ultrasonographic guidance at a median of 116 months (range, 102–127 months) after the revision procedure. Eleven biopsy specimens from asymptomatic patellar tendons obtained from open anterior cruciate ligament reconstructions served as controls. The histologic characteristics and the presence of glycosaminoglycans were assessed using a light microscope, and the ultrastructure was assessed using a transmission electron microscope.

Results

The histological evaluation revealed deterioration in fiber structure, increased cellularity, and increased vascularity in both the central and peripheral parts of the reharvested patellar tendon specimens compared with normal tendon specimens. No difference in the amount of glycosaminoglycans was seen in specimens from either part of the reharvested patellar tendons and the control specimens. The ultrastructural evaluation revealed that all the control specimens had a normal morphologic appearance and a compact extracellular matrix with regularly oriented collagen fibrils. Furthermore, in the control specimens, the fibril diameter was heterogeneous, with all fibril size classes present. Specimens from the central and the lateral part of the reharvested tendon displayed pathological cell appearance and a more heterogeneous extracellular matrix. The lateral specimens from the reharvested tendons also displayed all fibril size classes but with a more homogeneous distribution. In the central specimens, the largest fibril size class was absent.

Conclusion

Ten years after its central third was reharvested for anterior cruciate ligament revision surgery, the patellar tendon had not normalized in terms of its histological and ultrastructural appearance.
Absorption of Dexamethasone Sodium Phosphate in Human Connective Tissue Using Iontophoresis
Authors: Gurney A. Burke , Wascher Daniel C.
Published: January 2008

Background

Iontophoresis ostensibly facilitates the delivery of medications through the skin to underlying tissues using a direct electrical current. Dexamethasone is the most commonly used medication with iontophoresis to treat a variety of connective tissue disorders.

Hypothesis

Iontophoresis will facilitate the absorption of dexamethasone into connective tissue compared with diffusion.

Study Design

Controlled laboratory study.

Methods

Twenty-nine adults undergoing anterior cruciate ligament reconstructive surgery using the semitendinosus/gracilis autograft were randomly assigned to either a true iontophoresis (TI) or sham iontophoresis (SI). In the TI group, a 40-mA/min dose of iontophoresis using a 0.4% (4 mg/mL) solution of dexamethasone was used targeting the semitendinosus tendon just before surgery. The SI group underwent the same treatment, but the machine was not turned on. Tissue was extracted within 4 hours of treatment and analyzed for dexamethasone. In addition, 2 control samples were sent to the laboratory for analysis.

Results

There was a statistically significant difference in dexamethasone concentrations between the groups ( P = .0216). Of the 16 samples in the TI group, 8 had measurable amounts of dexamethasone, with an average concentration of 2.906 ng/g of tendon tissue. In the SI group, 1 of the 13 samples had measurable amounts of dexamethasone with an average concentration of 0.205 ng/g of tendon tissue. The control samples contained no dexamethasone.

Conclusion

Iontophoresis facilitates the transmission of dexamethasone to connective tissues in humans.

Clinical Relevance

Iontophoresis can deliver dexamethasone to connective tissues in humans.
Comparison of Weight Gain in Treatments for Tourette Syndrome: Tetrabenazine Versus Neuroleptic Drugs
Authors: Ondo William G. , Jong Daniel , Davis Anthony
Published: January 2008

Weight gain occurs with most neuroleptic drugs used to treat tics. Tetrabenazine, a vesicular monoamine transporter type 2 inhibitor, inhibits dopamine release. It is used to treat a variety of hyperkinetic movement disorders, including tics. Weight gain over time was compared in a group of pediatric tic patients taking only tetrabenazine with an age-matched group of tic patients taking only neuroleptic drugs. Age in the tetrabenazine group (n = 36, 32 males) at initial therapy was 13.4 (SD 3.3) years. They were monitored for 25.2 (SD 12.3) months. The average dose of tetrabenazine (all visits) was 54.4 (SD 26.6) mg/d. In the neuroleptic group (n = 41, 33 males), the age at therapy onset was 12.3 ± 4.0 years. They were monitored for 18.9 (SD 14.8) months. Weight increase was 0.8 lb/mo in the tetrabenazine group compared with 1.7 lb/mo in the neuroleptic group ( P = .006). Most patients who switched from a neuroleptic drug to tetrabenazine subsequently lost weight. Although the study was not designed to compare efficacy, this tended to be greater with tetrabenazine than with neuroleptic drugs.
Epileptic Spasms: A Variety of Etiologies and Associated Syndromes
Authors: Goldstein Joshua , Slomski Jessica
Published: January 2008

Epileptic spasms have been described as a paroxysmal epileptic seizure type that consists of a series of motor movements, involving sudden flexion or extension predominantly of axial and/or proximal limb muscles, occurring with a noticeable periodicity, outside the age of infantile spasms, but have otherwise not been well characterized or described. The purpose of this study was to evaluate patients with epileptic spasms to describe the etiology and best treatment regimen for this seizure type. Twenty-eight children fit the selection criteria for this study, and their charts and electroencephalography (EEG) results were reviewed. Data regarding onset of seizures, characteristics of seizures, duration of seizures, activity at onset, treatments tried and/or failed, genetic or metabolic workup, and results of any imaging studies were collected. The results indicate that the genetic and metabolic workups that were done were most often negative or unrevealing. In addition, treatment regimens varied greatly from patient to patient, and it is evident that these seizures are refractory to many standard anticonvulsants, as well as the ketogenic diet. The results of imaging from this series point to a variety of structural abnormalities that could possibly explain a structural versus metabolic etiology for epileptic spasms. In conclusion, epileptic spasms remain an elusive seizure type to classify, diagnose, and treat. The results of the current series show a relationship between structural abnormalities on magnetic resonance imaging (MRI) and resultant epileptic spasms, which has further implications regarding surgical treatment of these seizures as opposed to the traditional treatment with anticonvulsants, to which epileptic spasms remain refractory.
Self-Rated Health
Authors: Wolinsky Fredric D. , Miller Thomas R. , Malmstrom Theodore K. , Miller J. Philip , Schootman Mario , Andresen Elena M. , Miller Douglas K.
Published: January 2008

Objective: Little is known about changes in self-rated health (SRH) among African Americans. Method: We examined SRH changes and trajectories among 998 African Americans 49 to 65 years old who we reinterviewed annually for 4 years, using multinomial logistic regression and mixed effect models. Results: Fifty-five percent had the same SRH at baseline and 4 years later, 25% improved, and 20% declined. Over time, men were more likely to report lower SRH levels, individuals with hypertension were less likely to report lower SRH levels, and those with congestive heart failure at baseline were more likely to report higher SRH levels. Lower SRH trajectory intercepts were observed for those with lower socioeconomic status, poorer health habits, disease history, and worse functional status. Those with better cognitive status had higher SRH trajectory intercepts. Discussion: The decline in SRH levels among 49- to 65-year-old African Americans is comparable to that of Whites.
Emotional Expression in Children Treated With ADHD Medication
Authors: Perwien Amy R. , Kratochvil Christopher J. , Faries Douglas , Vaughan Brigette , Busner Joan , Saylor Keith E. , Buermeyer Curtis M. , Kaplan Stuart , Swindle Ralph
Published: January 2008

Objective: Although existing instruments contain items addressing the effect of ADHD medications on emotional expression, a review of measures did not yield any instruments that thoroughly evaluated positive and negative aspects of emotional expression. Method: The Expression and Emotion Scale for Children (EESC), a parent-report measure, was developed from an analysis of qualitative data from parent focus groups and expert opinion. Data from 179 parents and children treated with stimulants or atomoxetine are used to examine the psychometric properties of the EESC. Results: The EESC demonstrates good internal consistency and test-retest reliability. A factor analysis yields three factors (positive, flat, and emotional lability) that were consistent with the predicted structure of the measure. Small to moderate correlations between the EESC and psychological symptom measures are found, with the strength of the relationships varying by symptom measure. Conclusion: The EESC shows appropriate psychometric properties and is appropriate for use in clinical and research settings. ( J. of Att. Dis. 2008; 11(5) 568-579)
Identifying, Evaluating, Diagnosing, and Treating ADHD in Minority Youth
Authors: Hervey-Jumper Heather , Douyon Karl , Falcone Tatiana , Franco Kathleen N.
Published: January 2008

Objective: This literature review describes evaluation and treatment of minority youth with ADHD. Method: A search of databases for reports of ADHD in minority children was conducted. Results: Interpretation of behavior varies among parents, as does their trust in health care providers and school personnel. Parents desire to avoid stigmatization of their children from diagnostic labels and medications. They may not understand the sequelae of inadequate treatment or fear side effects of treatment. Children respond to stimulant medication but fare better when it is combined with regularly scheduled psychosocial treatment, including education and support for parents. Financial struggles affect access, evaluation, and treatment. Community support is desperately needed to gain parental trust. Creative planning allows health care providers and neighborhood leaders to join in, benefiting the children. Conclusion: Quality evaluation by a competent provider, careful choice of assessment tools, clear communication with parents, and close follow-up of progress are all needed. (J. of Att. Dis. 2008; 11(5) 522-528)
A Case of ADHD and a Major Y Chromosome Abnormality
Authors: Mulligan Aisling , Gill Michael , Fitzgerald Michael
Published: January 2008

Background: ADHD is a common, heritable disorder of childhood. Sex chromosome abnormalities are relatively rare conditions that are sometimes associated with behavioral disorders. Method: The authors present a male child with ADHD and a major de-novo Y chromosome abnormality consisting of deletion of the long arm and duplication of the short arm. It is possible that the Y chromosomal abnormality is causing the ADHD syndrome in this boy. Conclusion: Considering this case and considering that (a) ADHD is more common in boys than in girls, (b) the transmission of some genes associated with ADHD may occur preferentially from fathers rather than from mothers, and (c) ADHD is more common in children with XYY syndrome and Turner's syndrome than in other children, the authors propose that the sex chromosomes may contain risk genes for ADHD. (J. of Att. Dis. 2008; 12(1) 103-105)
ADHD, Substance Use Disorders, and Psychostimulant Treatment
Authors: Kollins Scott H.
Published: January 2008

Objective: This review explores the relationship between ADHD and substance use disorder (SUD), factors that determine the abuse potential of psychostimulants, and strategies for identifying and treating at-risk ADHD patients. Method: This study uses a Medline review of literature. Results: Psychostimulants, such as methylphenidate and amphetamines, are effective first-line pharmacotherapy for ADHD and when used appropriately in individuals with ADHD do not appear to be frequently abused by patients. Diversion and misuse of prescription stimulants are growing concerns, especially among young adults and college students. Short-acting psychostimulant formulations may have higher potential for abuse, misuse, and diversion, but more data are needed to substantiate this observation. Nonstimulant treatments for ADHD may be considered for patients at particularly high risk for substance use, misuse, or diversion of stimulants. Conclusion: In treating patients with ADHD and comorbid substance use, psychostimulants may be a useful pharmacologic alternative. However, the risks of such treatment with high-risk populations must be considered alongside potential benefits. (J. of Att. Dis. 2008; 12(2) 115-125)
Adults With ADHD Benefit From Cognitive—Behaviorally Oriented Group Rehabilitation
Authors: Virta Maarit , Vedenpää Anita , Grönroos Nina , Chydenius Esa , Partinen Markku , Vataja Risto , Kaski Markus , Iivanainen Matti
Published: January 2008

Objective: In clinical practice, a growing need exists for effective nonpharmacological treatments of adult ADHD. The authors present results from a cognitive—behaviorally oriented psychological group rehabilitation for adult ADHD. Method: A total of 29 adults with ADHD participated. Rehabilitation consisted of 10 or 11 weekly sessions. Participants were assessed with self-ratings (checklist for ADHD based on the Diagnostic and Statistical Manual of Mental Disorders , Beck Depression Inventory II, Symptom Check List-90 [SCL-90], Brown ADD Scale for Adults [BADDS]), and the ratings of their significant others (BADDS) 3 months prior to treatment, at the beginning of treatment, and at the end of treatment. Also, the Wender Utah Rating Scale questionnaire was completed prior to rehabilitation. Results: Rehabilitation resulted in reduced self-reported symptoms in 16 ADHD-related items of SCL-90, BADDS total score, and BADDS subdomains of activation and affect. Conclusion: Results suggest that cognitive—behavioral group rehabilitation can be suitable in treating adult ADHD. (J. of Att. Dis. 2008; 12(3) 218-226)
Feasibility and Preliminary Efficacy of an After-School Program for Middle Schoolers With ADHD
Authors: Molina Brooke S. G. , Flory Kate , Bukstein Oscar G. , Greiner Andrew R. , Baker Jennifer L. , Krug Vicky , Evans Steven W.
Published: January 2008

Objective: This pilot study tests the feasibility and preliminary efficacy of an after-school treatment program for middle schoolers with ADHD using a randomized clinical trial design. Method: A total of 23 students with ADHD (25% female, 48% African American) from a large public middle school were randomly assigned to a 10-week program or to community comparison. Manualized treatment targeted educational, social, and recreational skills, homework completion, and school and home behavior. Parents participated. Results: Recruitment and randomization targets were easily met (87% completion). Parent and teacher satisfaction was positive. Small to medium treatment effects resulted despite greater medication use in the control group, with improvements in functioning for the program-treated youth or absence of deterioration relative to the comparison group. Conclusion: Despite testing an abbreviated version of the after-school program (< 5 months), this study reveals feasibility and palatability for this intervention and modest beneficial effects on behavioral and academic outcomes. (J. of Att. Dis. 2008; 12(3) 207-217)
Correlative Studies of Structural and Functional Imaging in Primary Progressive Aphasia
Authors: Panegyres P.K. , McCarthy M. , Campbell A. , Lenzo N. , Fallon M. , Thompson J.
Published: January 2008

Rationale: To compare and contrast structural and functional imaging in primary progressive aphasia (PPA). Methods: A cohort of 8 patients diagnosed with PPA presenting with nonfluency were prospectively evaluated. All patients had structural imaging in the form of MRI and in 1 patient CAT scanning on account of a cardiac pacemaker. All patients had single-photon emission computed tomography (SPECT) and positron emission tomography (PET) imaging. Results: SPECT and PET imaging had 100% correlation. Anatomical imaging was abnormal in only 6 of the 8 patients. Wernicke's area showed greater peak Z score reduction and extent of area affected than Broca's area (McNemar paired test: P = .008 for Z score reduction; P = .0003 for extent). PET scanning revealed significant involvement of the anterior cingulum. Conclusion: Functional imaging in PPA: ( a) identified more patients correctly than anatomic imaging highlighting the importance of SPECT and PET in the diagnosis; and ( b) demonstrated the heterogeneous involvement of disordered linguistic networks in PPA suggesting its syndromic nature.
State of the Art Reviews: Male Menopause: Fact or Fiction?
Authors: Wald Moshe , Miner Martin , Seftel Allen D.
Published: January 2008

The possible existence of a menopause-like process in aging men has been speculated, given certain age-related hormonal and other biological changes noted to occur. Specifically, a slow decline in serum testosterone levels has been reported to occur with normal male aging. Androgen deficiency, which may result from this process, could have an effect on various systems and physiologic parameters, including bone density, body composition, sexual function, and the cardiovascular system, thus significantly affecting health and quality-of-life issues in older men. There has been an increasing interest in evaluating the possible use of testosterone replacement in preventing some detrimental aspects of aging and age-related hypogonadism, as well as in the investigation of the potential adverse effects of this therapy on different target organs. It is the purpose of this review to summarize currently available information with regard to the changes in testosterone and other hormones in older men, discuss their possible clinical manifestations and relationship with other age-related changes, and provide an updated description of testosterone replacement therapy for older men, including its indications, formulations, and safety considerations.