bluuebunny/crossref_metadata_2025 huggingface dataset:
Intellectual Disability in the Context of a South African Population
Authors: Kromberg Jennifer , Zwane Esther , Manga Prashiela , Venter Andre , Rosen Eric , Christianson Arnold
Published: June 2008

Abstract  Childhood disabilities, including intellectual disabilities (ID), are thought to occur in 5–17% of children in developing countries around the world. In order to identify and describe the childhood disabilities occurring in a rural South African population, as well as the context in which they occur, a study was carried out in the Bushbuckridge district in the poor northeast part of the country. Altogether, 6,692 children were screened in their homes in eight villages using the Ten Questions questionnaire. This questionnaire was used by local‐trained field‐workers in interviews with mothers and other carers, to screen children for five disorders (viz., intellectual, hearing, visual and movement disorders, and epilepsy). Altogether, 722 (10.8% of the total sample) children, who screened positive, were examined at clinics in their villages by a pediatrician for diagnostic, treatment, and referral purposes. In addition, 100 traditional healers in the district were interviewed with a specially designed schedule of questions to assess their attitudes toward disabilities and their management of affected children. The results showed that 291 (4.3%) children had at least one of the five disabilities. ID occurred in 3.6%, epilepsy in 0.7%, visual disorders in 0.5%, movement disorders in 0.5%, and hearing disorders in 0.3%. More boys than girls with hearing disorders were receiving special education. Many of the affected children were not receiving treatment or education, resulting in a reduction in their quality of life. Traditional healers were attempting to treat epilepsy and seldom referred affected children to hospital, although effective treatment was available there. Genetic factors were involved in about half the conditions, but genetic services were negligible. Appropriate health, diagnostic, treatment, educational, and supportive services are required for children with disabilities, and awareness of their needs and the resources to meet them should be increased in this community.
A prospective study comparing PlasmaKnife with bipolar dissection tonsillectomy: a preliminary communication of an emerging technology
Authors: Singh A. , Stephens J. , Ghufoor K. , Sandhu G.
Published: June 2008

Objective:  To clinically evaluate and compare the PlasmaKnife to bipolar electrocautery in paediatric tonsillectomy.

Design:  Prospective comparitive non‐randomised study.

Setting:  Central London teaching hospital with tertiary referrals.

Participants:  Forty‐three patients aged 3–12 years with recurrent tonsillitis or obstructive adenotonsillar hypertrophy awaiting a tonsillectomy were recruited into the study.

Main outcome measures:  Primary outcome was throat, ear and swallowing pain scores over 2 weeks. Secondary measures included: return to normal diet, return to normal activity, analgesic requirements, operation time and intraoperative blood loss.

Results:  Surgical dissection was similar between the two groups with minimal blood loss and comparable overall operative times. Median throat pain scores suggest PlasmaKnife to be less painful in the early postoperative period (at 8 h, P < 0.005) but, overall, did not quite reach statistical significance (Mann–Whitney U‐test). PlasmaKnife was similar to bipolar in all other measured categories. During the study, three secondary bleeds occurred in the PlasmaKnife group and all were managed conservatively.

Conclusion:  PlasmaKnife is a safe new technology with similar outcome to the established bipolar technique. This preliminary study finds PlasmaKnife to be an interesting instrument and warrants a larger randomised study to truly evaluate the potential advantages of lowered pain and early recovery attributed to this emerging technology.
The long‐term effect of unilateral t‐tube insertion in patients undergoing cleft palate repair: 20‐year follow‐up of a randomised controlled trial
Authors: Hornigold R. , Morley A. , Glore R.J. , Boorman J. , Sergeant R.
Published: June 2008

Objectives:  Between July 1984 and March 1987, all children that underwent repair for primary cleft palate at the Queen Victoria Hospital were enrolled in a clinical trial. Those found to have otitis media with effusion at time of surgery had a t‐tube inserted into one randomised ear, whilst the other ear received no treatment. The object of the study was to reassess the patients from the original trial to discover the impact of the unilateral t‐tube, twenty years later analysed on an intention to treat basis.

Design:  Children that underwent primary palatal closure during the study dates were identified from the cleft palate database. Patients that were involved in the original trial were identified, contacted and invited to take part in the follow‐up study.

Setting:  Tertiary referral Specialist unit.

Participants:  Twenty‐two patients were identified as potential study participants. Of this group, fourteen were contactable and seven participants agreed to take part in our follow‐up study.

Main outcome measures:  Persistent symptomatology, otoscopy, pure tone audiometry and tympanometry.

Results:  Follow‐up results were compared within the original treatment groups from the primary study, on an intention to treat basis. Otoscopically the ears were normal in 2 of the 7 treated ears compared with four of the seven non‐treated ears. All the other ear ears had various types of chronic otitis media. Four of the seven had hearing of >10 dB in the treated ear compared with the non‐treated ear.

Conclusions:  These findings would indicate need for caution in the use of t‐tubes in the cleft population and raises the question of long‐term follow‐up to assess for secondary cholesteatoma.
Sensorineural hearing loss due to Toxoplasma gondii in children: a case–control study
Authors: Noorbakhsh S. , Memari F. , Farhadi M. , Tabatabaei A.
Published: June 2008

Objective:  Sensorineural hearing loss (SNHL) can follow congenital toxoplasmosis. Treatment in the first year of life is associated with diminished occurrence of this sequel. In various parts of Iran, the prevalence of antibodies to Toxoplasma gondii ranges from 24% to 57.7%. We evaluate the possible role of Toxoplasma gondii infection on the occurrence of SNHL in children.

Design and setting:  This case‐control study was performed in a tertiary care center in Tehran between 2002 and 2003. This study was carried out based on diagnostic parameters of the American Academy of Otolaryngology criteria for SNHL and a healthy control group.

Main outcome measures:  We compared the specific Toxoplasma gondii antibodies (IgM & IgG) measured by ELISA in 95 blood samples of infants with SNHL and 63 healthy matched infants.

Results:  Acute (IgM) and previous (IgG) immunity to Toxoplasma gondii was found in 12 and 21.2% of SNHL children, respectively. Most cases with previous infections (IgG positive) were children aged less than 1 year old (i.e. maternal immunity), but acute infection (IgM positive) was higher in 3–5 year old age group. Acute infection (IgM) was significantly more frequent in the SNHL group, and previous immunity was higher in the controls (CI 95%, P‐value = 0.01; 0.01).

Conclusion:  With respect to seropositive children, as we were unable to differentiate congenital from acquired cases, we recommend prevention of congenital toxoplasmosis by treatment of Toxoplasma infection in pregnant women and treatment of acquired Toxoplasma gondii infection after birth to minimise the risk of SNHL in children.
Failed voice restoration: closure of the tracheo‐oesophageal fistula
Authors: Judd O. , Bridger M.
Published: June 2008

Keypoints

Tracheo‐oesophageal fistula and voice prosthesis have revolutionised voice rehabilitation, but are not without their complications.

The most significant problem is widening of the tracheo‐oesophageal fistula relative to the voice prosthesis and subsequent leaking.

Three‐layer surgical closure is a means of permanently closing a problematic fistula.

Use of an interposition in situ muscle graft as a second layer provides an adequate, well vascularised barrier to prevent fistula reformation. Our technique provides a safe, effective method of closing a problematic tracheo‐oesophageal fistula.

We report a five case series in which 100% of patients acquired satisfactory closure of their fistulae and resolution of their symptoms.
The role of nervus intermedius in side specific nasal responses
Authors: Nichani J.R. , Malik V. , Woolford T.J. , Ramsden R.T. , Homer J.J.
Published: June 2008

Introduction.  Nervus intermedius (NI) dysfunction is common in patients who have had vestibular schwannoma (VS) surgery.1 Such patients have a unilateral parasympathetic‐denervated nasal cavity. A number of side‐specific nasal reflexes have been demonstrated in normals, including hand cold water immersion.2 It is not understood whether these reflexes have parasympathetic or sympathic efferent pathways.

Objectives.  To evaluate the side specific nasal reflex to cold‐water immersion in post‐operative VS patients with NI dysfunction, in order to determine the nature of the efferent pathway of these reflexes.

Method.  The study of Wilde2 was repeated in 10 normal controls. Then a cohort observational study with internal controls was designed to evaluate the role of nasal parasympathetic innervation in patients who had unilateral VS surgery and NI dysfunction (Schirmer's test). Side specific response to cold‐water immersion was tested by acoustic rhinometry.

Results.  A consistent pattern of ipsilateral congestion and contralateral decongestion after the cold water immersion was seen in normals (P < 0.001 for both responses.) We found no consistent response in 18 VS patients on testing with stimulus ipsilateral to side of NI dysfunction and contralateral (the internal control).

Conclusions.  We confirm the consistent side‐specific nasal reflexes to cold water hand immersion in normals. This is disturbed in individuals following unilateral VS surgery with NI dysfunction. We have also shown that the contralateral side‐specific reflex is disturbed in these patients. These data suggest that the reflex is parasympathetic and crosses the midline.

References.

1 Irwing R.M., Viani L., Hardy D.G., Baguley D.M. & Moffat D.A. Nervus intermedius function after vestibular schwannoma removal: clinical features and pathophysiological mechanisms. Laryngoscope 105, 809–813

2 Wilde A.D. (1999) The effect of cold water immersion on the nasal mucosa. Clin. Otolaryngol. 24, 411–413
Is laryngopharyngeal reflux associated with changes in laryngeal mucosal flora?
Authors: Birchenall K.A. , Cogan T.A. , Birchall M.A. , Rees L.E.N.
Published: June 2008

Objectives.  To determine whether laryngeal reflux (LPR) affects the population size and distribution of laryngeal mucosal flora in humans; and whether LPR alters the integrity of the laryngeal mucosa. Further, to specifically assess whether Helicobacter pylori (H. pylori) is present in the laryngeal mucosa and if LPR is associated with this.

Methods.  Laryngeal mucosal biopsies were taken from patients diagnosed LPR‐positive or LPR‐negative, none of whom had laryngeal disease. Presence of bacteria and epithelial integrity were determined by: fluorescent in situ hybridisation using oligonucleotide probes specific to all Eubacteria and H. pylori; real‐time PCR specific for H. Pylori and all bacteria; and immunofluorecence using an antibody to occludin.

Results.  Helicobacter pylori was discovered in all the biopsies tested – both in those taken from patients who did not have LPR and those that did – with no significant difference in its distribution between the two groups. Helicobacter pylori was found in both the epithelium and lamina propria of the laryngeal mucosa. Further, an increase in the number of total Eubacteria present in the laryngeal mucosa was found to be significantly associated with LPR (LPR mean 58.2 se 19.0 bacteria/field of view, non‐LPR mean 17.3 se 4.7; P = 0.02).

Conclusions.  The association between LPR and an increase in total Eubacteria in the laryngeal mucosa presents a possible aetiology for pathological symptoms associated with LPR. The fact that H. pylori was present in all of the laryngeal mucosal biopsies has significant implications for upper airway research.
Oncolytic vaccinia virus armed with the endostatin‐angiostatin fusion protein; a novel therapy for head and neck cancer
Authors: Tysome J. , Alusi G. , Fodor I. , Lemoine N. , Wang Y.
Published: June 2008

Objectives.  The survival of patients with head and neck squamous cell carcinoma (HNSCC) has not improved significantly over recent decades. This had lead to the development of new therapies. Oncolytic viral therapy is a promising new strategy for cancer treatment. The first oncolytic virus licensed for treatment was an adenovirus for HNSCC.1 However, the outcomes of clinical trials using viral monotherapy have been disappointing. Oncolytic vaccinia virus represents an attractive alternative as its replication is less dependent than adenovirus on the genetic make‐up of host cells and it has been used safely as the smallpox vaccine in millions of patients.2

Method.  This study evaluated the potential of vaccinia virus as a treatment for HNSCC in vitro and in human xenograft models in vivo.

Results.  The Lister strain of vaccinia virus was more potent than adenovirus against all tumour cells tested in vitro. The virus displayed high selectivity for cancer cells, sparing normal cells both in vitro and in vivo. In order increase antitumour potency, a novel vaccinia virus expressing the endostatin–angiostatin fusion protein was constructed. This inhibits new blood vessel formation as well as tumour growth by oncolysis. The protein was both expressed in virus‐infected tumour cells and demonstrated function by the inhibition of human umbilical vein epithelial cell proliferation and tube formation in vitro.

Conclusions.  This novel vaccinia virus is a promising therapeutic agent for HNSCC, which requires further evaluation in vivo.

References.  1 Garber K. (2006) China approves world's first oncolytic virus therapy for cancer treatment. J. Natl. Cancer Inst. 98, 298–300

2 Thorne S.H., Bartlett D.L. & Kirn D.H. (2005) The use of oncolytic vaccinia viruses in the treatment of cancer: a new role for an old ally? Curr. Gene Ther. 5, 429–443
On the Quality of Commercial Boneless Skinless Broiler Breast Meat
Authors: Lee Y.S. , Owens C.M. , Meullenet J.F.
Published: June 2008

ABSTRACT:  This study was conducted to assess the overall quality of commercial broiler breast meat products representing several brands and various industry practices (that is, chilling or enhancement procedures). Six different broiler breast products were evaluated by 75 consumers for 11 attributes related to appearance, flavor, tenderness, and juiciness, including overall acceptance. Twenty‐three sensory attributes representing basic taste, flavor, texture, and appearance were evaluated by 11 trained descriptive panelists. Tenderness of cooked meat was instrumentally predicted by the Meullenet–Owens razor shear (MORS). Water holding capacity (cook loss) of cooked meat was also evaluated, and color and pH of raw meat were determined. Significant variations in quality among products tested were reported, indicating a broad range of product quality in the marketplace. One air‐chilled and 1 water‐chilled/enhanced product were found to be most liked by consumers. Tenderness of products tested was rated in average between “neither tough nor tender” and “very tender” by consumers. Cook loss of the 2 air‐chilled products (13.5% to 19.1%, respectively) was significantly lower than that of water‐chilled products (18.7% to 24.1%). Partial least squares regression revealed that 4 sensory texture attributes (hardness, hardness of mass, cohesiveness of mass, and tooth pack) and 1 basic taste (sour) were the major attributes driving consumer overall liking of commercial broiler breast meat products.
SERMIN1 and VIDAC18: Two Proposed Reference Materials for Rare Earth Element Determination in Groundwater
Authors: Santos Rui , Machado M.J. Canto , Cortez Leopoldo
Published: June 2008

In this work, homogeneous samples of two Portuguese mineral waters, SERMIN1 and VIDAC18, have been analysed for their REE contents. The participation of twenty international laboratories made it possible to evaluate the data by robust statistical procedures. Eighty‐one percent of the participants used ICP‐QMS for REE determination in these two candidate reference materials. Assigned values are reported for SERMIN1, covering the fourteen naturally occurring lanthanides (La‐Lu). For VIDAC18, assigned values are presented only for ten REE, since accurate assigned values for La, Ce, Tb and Eu need further analytical work to improve data quality.
In Situ Multi‐Element Analysis of the Mount Pinatubo Quartz‐Hosted Melt Inclusions by NIR Femtosecond Laser Ablation‐Inductively Coupled Plasma‐Mass Spectrometry
Authors: Borisova Anastassia Yu. , Freydier Rémi , Polvé Mireille , Salvi Stefano , Candaudap Frederic , Aigouy Thierry
Published: June 2008

Microscopic melt inclusions found in magmatic minerals are undoubtedly one of the most important sources of information on the chemical composition of melts. This paper reports on the successful application of near‐infrared (NIR) femtosecond laser ablation (LA) ‐ inductively coupled plasma‐mass spectrometry to in situ determination of incompatible trace elements (Li, Rb, Sr, Y, Zr, Nb, Cs, Ba, REE, Ta, Th, U) and ore metals (As, Mo, Pb) in individual melt inclusions hosted in quartz from the Mount Pinatubo dacites, Philippines. The determined elements cover a concentration range of five orders of magnitude. Femtosecond LA‐ICP‐MS analyses of twenty‐eight individual melt inclusions demonstrate the efficiency of the microanalytical technique and suggests a spectacular homogeneity of the entrapped melt, at least with respect to the following incompatible trace elements: Rb, Sr, Nb, Cs, Ba, La, Ce, Pr, Nd, Pb, Th. The analytical precision (1s) for Na, Ca, Rb, Sr, Y, Nb, Ba and LREE ranged from 3 to 20%. Comparison of trace element concentrations in Mt. Pinatubo melt inclusions determined by femtosecond LA‐ICP‐MS with those of melt inclusions previously analysed by secondary ion mass spectrometry analysis (SIMS) and those of matrix glasses previously determined by nanosecond LA‐ICP‐MS showed an agreement typically within 30–40%. The homogeneity of trace element concentrations of the Mt. Pinatubo melt inclusions and the matrix glasses is consistent with the melt inclusion origin as homogeneous rhyolitic melt that was trapped in quartz phenocrysts at the final crystallisation stages of the host adakite (dacite) magma.
Certificate of Analysis of the Reference Material BRP‐1 (Basalt Ribeirão Preto)
Authors: Cotta Aloísio J.B. , Enzweiler Jacinta
Published: June 2008

Reference materials (RM) are essential to achieve traceability of measurements. Specific uses of RM in analytical laboratories are the validation of methods, the calibration of instruments, the quality control and the demonstration of proficiency. This paper describes the certification of a new geochemical reference material, named BRP‐1 (Basalt Ribeirão Preto), and acts as the certificate of analysis for this RM. The rock sample was crushed and pulverised at the USGS (Denver, USA), homogenised and split into 1920 bottles, with 55 g each. BRP‐1 was transported back to Brazil and the homogeneity between and within bottles was assessed to demonstrate sufficient homogeneity for certification. The chemical characterisation was performed by twenty‐five laboratories. Each laboratory received two bottles of BRP‐1 and one of BCR‐2 (Basalt Columbia River) used for quality control (QC). Reference values and uncertainties were calculated for forty‐four constituents of BRP‐1, following ISO Guide 35 recommendations and the IAG Protocol. The calculation of each reference value included data of proven traceability from at least ten laboratories using two or more analytical techniques and the uncertainties combines the characterisation and between bottle homogeneity contributions.
Therapeutic Efficacy of a Conjugate Vaccine Containing a Peptide Mimotope of Cryptococcal Capsular Polysaccharide Glucuronoxylomannan
Authors: Datta Kausik , Lees Andrew , Pirofski Liise-anne
Published: June 2008

Vaccination with P13, a peptide mimotope of the cryptococcal capsular polysaccharide glucuronoxylomannan (GXM), has been shown to confer protection against a subsequent lethalCryptococcus neoformanschallenge. In this study, we sought to investigate whether P13-based vaccines could be effective in an already-established infection. To address this question, we developed a systemic chronic cryptococcal infection model. We vaccinated chronically infected mice with P13-protein conjugates and monitored their survival. Compared to the controls, the conjugates prolonged the survival of chronically infected mice. The degree of protection was a function of the mouse strain (BALB/c or C57BL/6), the carrier protein (tetanus toxoid or diphtheria toxoid), and the route of infection (intraperitoneal or intravenous). Serum GXM levels were correlated with the day of death, but the correlation was driven by the carrier protein and mouse strain. The passive transfer of heat-treated sera from P13 conjugate-vaccinated mice conferred protection to naïve BALB/c mice, indicating that antibody immunity could contribute to protection. The measurement of peripheral blood cytokine (gamma interferon [IFN-γ], interleukin-10 [IL-10], and IL-6) gene expression showed that P13 conjugate-vaccinated BALB/c and C57BL/6 mice mounted a strong Th2 (IL-10)-like response relative to the Th1 (IFN-γ)-like response, with the degree depending on the mouse strain and carrier protein. Taken together, our data suggest that a vaccine could hold promise in the setting of chronic cryptococcosis, and that vaccine efficacy could depend on immunomodulation and augmentation of the natural immune response of the host.
Detection of All Known Parechoviruses by Real-Time PCR
Authors: Nix W. Allan , Maher Kaija , Johansson E. Susanne , Niklasson Bo , Lindberg A. Michael , Pallansch Mark A. , Oberste M. Steven
Published: June 2008

TheParechovirusgenus of thePicornaviridaefamily contains two species,Human parechovirus(HPeV) andLjungan virus(LV). The HPeVs (including the former echoviruses 22 and 23, now HPeV type 1 (HPeV1) and HPeV2, respectively) cause a wide spectrum of disease, including aseptic meningitis, gastroenteritis, encephalitis, acute respiratory illness, and neonatal sepsis-like disease. The LVs were isolated from bank voles in Sweden during a search for an infectious agent linked to fatal myocarditis cases in humans. Because of the decline in use of cell culture and neutralization to investigate enterovirus-like disease, very few laboratories currently have the capability to test for parechoviruses. We have developed a real-time reverse transcription-PCR (RT-PCR) assay for detection of all known members of the genusParechovirus. The assay targets the conserved regions in the 5′ nontranslated region (5′NTR) of the parechovirus genome and can detect both HPeVs and LVs, unlike other published parechovirus 5′ NTR assays, which only detect known HPeVs or only LVs. HPeV and LV can be differentiated by sequencing the 5′NTR real-time RT-PCR amplicon, when needed. The assay is approximately 100 times more sensitive than cell culture and may be used to test original clinical specimens. The availability of a broad-specificity PCR method should facilitate the detection of new human parechoviruses, as well as new parechoviruses in other mammalian species, and provide an opportunity to investigate the role of these viruses in human and animal disease.
Sensitive Detection of Multiple Rotavirus Genotypes with a Single Reverse Transcription-Real-Time Quantitative PCR Assay
Authors: Gutiérrez-Aguirre Ion , Steyer Andrej , Boben Jana , Gruden Kristina , Poljšak-Prijatelj Mateja , Ravnikar Maja
Published: June 2008

Rotaviruses are one of the major causes of diarrhea in infants and children under 5 years old, especially affecting developing countries. In natural disasters, fecal matter and potable waters can mix, allowing low, yet infective, concentrations of rotavirus to be present in water supplies, constituting a risk for the population. Any of the most commonly detected rotavirus genotypes could originate an outbreak. The development of a fast and sensitive method that could detect the broadest possible range of rotavirus genotypes would help with efficient diagnosis and prevention. We have designed a reverse transcription (RT)-real-time quantitative PCR approach targeted to the rotaviral VP2 gene, based on a multiple-sequence alignment of different human rotaviral strains. To overcome the high nucleotide sequence diversity, multiple forward and reverse primers were used, in addition to a degenerate probe. The performance of the assay was tested on isolates representing the most prevalent human genotypes: G1P[8], G2P[4], G3P[8], G4P[8], G9P[8], and G12P[8]. The developed method improved classical rotavirus detection by enzyme-linked immunosorbent assay and nested RT-PCR by 5 and at least 1 order of magnitude, respectively. A survey of 159 stool samples indicated that the method can efficiently detect a broad range of rotavirus strains, including different G-P genotype combinations of human, porcine, and bovine origin. No cross-reactivity was observed with other enteric viruses, such as astrovirus, sapovirus, and norovirus.
Dendritic Cells Preferentially Transfer CXCR4-Using Human Immunodeficiency Virus Type 1 Variants to CD4+T Lymphocytes intrans
Authors: van Montfort Thijs , Thomas Adri A. M. , Pollakis Georgios , Paxton William A.
Published: June 2008

Human immunodeficiency virus type 1 (HIV-1) preferentially utilizes the CCR5 coreceptor for target cell entry in the acute phase of infection, while later in disease progression the virus switches to the CXCR4 coreceptor in approximately 50% of patients. In response to HIV-1 the adaptive immune response is triggered, and antibody (Ab) production is elicited to block HIV-1 entry. We recently determined that dendritic cells (DCs) can efficiently capture Ab-neutralized HIV-1, restore infectivity, and transmit infectious virus to target cells. Here, we tested the effect of Abs ontranstransmission of CCR5 or CXCR4 HIV-1 variants. We observed that transmission of HIV-1 by immature as well as mature DCs was significantly higher for CXCR4- than CCR5-tropic viral strains. Additionally, neutralizing Abs directed against either the gp41 or gp120 region of the envelope such as 2F5, 4E10, and V3-directed Abs inhibited transmission of CCR5-tropic HIV-1, whereas Ab-treated CXCR4-tropic virus demonstrated unaltered or increased transmission. To further study the effects of coreceptor usage we tested molecularly cloned HIV-1 variants with modifications in the envelope that were based on longitudinal gp120 V1 and V3 variable loop sequences from a patient progressing to AIDS. We observed that DCs preferentially facilitated infection of CD4+T lymphocytes of viral strains with an envelope phenotype found late in disease. Taken together, our results illustrate that DCs transmit CXCR4-tropic HIV-1 much more efficiently than CCR5 strains; we hypothesize that this discrimination could contribute to the in vivo coreceptor switch after seroconversion and could be responsible for the increase in viral load.
Human Immunodeficiency Virus Infection Alters Tumor Necrosis Factor Alpha Production via Toll-Like Receptor-Dependent Pathways in Alveolar Macrophages and U1 Cells
Authors: Nicol Marlynne Q. , Mathys Jean-Marie , Pereira Albertina , Ollington Kevin , Ieong Michael H. , Skolnik Paul R.
Published: June 2008

Human immunodeficiency virus (HIV)-positive persons are predisposed to pulmonary infections, even after receiving effective highly active antiretroviral therapy. The reasons for this are unclear but may involve changes in innate immune function. HIV type 1 infection of macrophages impairs effector functions, including cytokine production. We observed decreased constitutive tumor necrosis factor alpha (TNF-α) concentrations and increased soluble tumor necrosis factor receptor type II (sTNFRII) in bronchoalveolar lavage fluid samples from HIV-positive subjects compared to healthy controls. Moreover, net proinflammatory TNF-α activity, as measured by the TNF-α/sTNFRII ratio, decreased as HIV-related disease progressed, as manifested by decreasing CD4 cell count and increasing HIV RNA (viral load). Since TNF-α is an important component of the innate immune system and is produced upon activation of Toll-like receptor (TLR) pathways, we hypothesized that the mechanism associated with deficient TNF-α production in the lung involved altered TLR expression or a deficit in the TLR signaling cascade. We found decreased Toll-like receptor 1 (TLR1) and TLR4 surface expression in HIV-infected U1 monocytic cells compared to the uninfected parental U937 cell line and decreased TLR message in alveolar macrophages (AMs) from HIV-positive subjects. In addition, stimulation with TLR1/2 ligand (Pam3Cys) or TLR4 ligand (lipopolysaccharide) resulted in decreased intracellular phosphorylated extracellular signal-regulated kinase and subsequent decreased transcription and expression of TNF-α in U1 cells compared to U937 cells. AMs from HIV-positive subjects also showed decreased TNF-α production in response to these TLR2 and TLR4 ligands. We postulate that HIV infection alters expression of TLRs with subsequent changes in mitogen-activated protein kinase signaling and cytokine production that ultimately leads to deficiencies of innate immune responses that predispose HIV-positive subjects to infection.
Zinc Finger Proteins Designed To Specifically Target Duck Hepatitis B Virus Covalently Closed Circular DNA Inhibit Viral Transcription in Tissue Culture
Authors: Zimmerman Kimberley A. , Fischer Karl P. , Joyce Michael A. , Tyrrell D. Lorne J.
Published: June 2008

Duck hepatitis B virus (DHBV) is a model virus for human hepatitis B virus (HBV), which infects approximately 360 million individuals worldwide. Nucleoside analogs can decrease virus production by inhibiting the viral polymerase; however, complete clearance by these drugs is not common because of the persistence of the HBV episome. HBV DNA is present in the nucleus as a covalently closed circular (cccDNA) form, where it drives viral transcription and progeny virus production. cccDNA is not the direct target of antiviral nucleoside analogs and is the source of HBV reemergence when antiviral therapy is stopped. To target cccDNA, six different zinc finger proteins (ZFP) were designed to bind DNA sequences in the DHBV enhancer region. After the binding kinetics were assessed by using electrophoretic mobility shift assays and surface plasmon resonance, two candidates with dissociation constants of 12.3 and 40.2 nM were focused on for further study. The ZFPs were cloned into a eukaryotic expression vector and cotransfected into longhorn male hepatoma cells with the plasmid pDHBV1.3, which replicates the DHBV life cycle. In the presence of each ZFP, viral RNA was significantly reduced, and protein levels were dramatically decreased. As a result, intracellular viral particle production was also significantly decreased. In summary, designed ZFPs are able to bind to the DHBV enhancer and interfere with viral transcription, resulting in decreased production of viral products and progeny virus genomes.
Adeno-Associated Virus Vector Genomes Persist as Episomal Chromatin in Primate Muscle
Authors: Penaud-Budloo Magalie , Le Guiner Caroline , Nowrouzi Ali , Toromanoff Alice , Chérel Yan , Chenuaud Pierre , Schmidt Manfred , von Kalle Christof , Rolling Fabienne , Moullier Philippe , Snyder Richard O.
Published: June 2008

Recombinant adeno-associated virus (rAAV) vectors are capable of mediating long-term gene expression following administration to skeletal muscle. In rodent muscle, the vector genomes persist in the nucleus in concatemeric episomal forms. Here, we demonstrate with nonhuman primates that rAAV vectors integrate inefficiently into the chromosomes of myocytes and reside predominantly as episomal monomeric and concatemeric circles. The episomal rAAV genomes assimilate into chromatin with a typical nucleosomal pattern. The persistence of the vector genomes and gene expression for years in quiescent tissues suggests that a bona fide chromatin structure is important for episomal maintenance and transgene expression. These findings were obtained from primate muscles transduced with rAAV1 and rAAV8 vectors for up to 22 months after intramuscular delivery of 5 × 10
12
viral genomes/kg. Because of this unique context, our data, which provide important insight into in situ vector biology, are highly relevant from a clinical standpoint.
Structural Variations in Species B Adenovirus Fibers Impact CD46 Association
Authors: Pache Lars , Venkataraman Sangita , Reddy Vijay S. , Nemerow Glen R.
Published: June 2008

A majority of species B adenoviruses (Ads) use CD46 as their primary receptor; however, the precise mechanisms involved in the binding of different Ad types to CD46 have not been resolved. Although previous studies indicate close similarities between two members of species B2 Ads in their usage of CD46, our current investigations revealed a surprisingly low CD46 binding affinity of the species B1 Ad16 fiber knob (equilibrium dissociation constant of 437 nM). We determined the crystal structure of the Ad16 fiber knob and constructed a model of this protein in complex with CD46. A comparison of this model to that of the CD46-Ad11 complex revealed structural differences in the FG and IJ loops that are part of the CD46 binding site. An analysis of a panel of recombinant fiber knobs with mutations targeting these regions in Ad16 and Ad11 uncovered a major contribution of the FG loop on CD46 binding. Two extra residues in the FG loop of the Ad16 fiber significantly reduce receptor interaction. Although avidity effects permit the use of CD46 on host cells by Ad16, virus binding occurs with lower efficiency than with B2 Ad types. The longer FG loop of the Ad16 fiber knob also is shared by other species B1 Ad fibers and, thus, may contribute to the low CD46 binding efficiencies observed for these Ad types. Our findings provide a better understanding of how different Ad types associate with CD46 and could aid in the selection of specific Ad fibers for more efficient Ad gene delivery vectors.
Influenza Virus Infection Augments NK Cell Inhibition through Reorganization of Major Histocompatibility Complex Class I Proteins
Authors: Achdout Hagit , Manaster Irit , Mandelboim Ofer
Published: June 2008

The killing by natural killer (NK) cells is regulated by inhibitory, costimulatory, and activating receptors. The inhibitory receptors recognize mainly major histocompatibility complex (MHC) class I molecules, while the activating NK receptors recognize stress-induced ligands and viral products. Thus, changes in the expression of the various inhibitory and activating ligands will determine whether target cells will be killed or protected. Here, we demonstrate that after influenza virus infection the binding of the two NK inhibitory receptors, KIR2DL1 and the LIR1, to the infected cells is specifically increased. The increased binding occurs shortly after the influenza virus infection, prior to the increased recognition of the infected cells by the NK activating receptor, NKp46. We also elucidate the mechanism responsible for this effect and demonstrate that, after influenza virus infection, MHC class I proteins redistribute on the cell surface and accumulate in the lipid raft microdomains. Such redistribution allows better recognition by the NK inhibitory receptors and consequently increases resistance to NK cell attack. In contrast, T-cell activity was not influenced by the redistribution of MHC class I proteins. Thus, we present here a novel mechanism, developed by the influenza virus, of inhibition of NK cell cytotoxicity, through the reorganization of MHC class I proteins on the cell surface.
Structure, Function, and Evolution of Bacterial ATP-Binding Cassette Systems
Authors: Davidson Amy L. , Dassa Elie , Orelle Cedric , Chen Jue
Published: June 2008

ATP-binding cassette (ABC) systems are universally distributed among living organisms and function in many different aspects of bacterial physiology. ABC transporters are best known for their role in the import of essential nutrients and the export of toxic molecules, but they can also mediate the transport of many other physiological substrates. In a classical transport reaction, two highly conserved ATP-binding domains or subunits couple the binding/hydrolysis of ATP to the translocation of particular substrates across the membrane, through interactions with membrane-spanning domains of the transporter. Variations on this basic theme involve soluble ABC ATP-binding proteins that couple ATP hydrolysis to nontransport processes, such as DNA repair and gene expression regulation. Insights into the structure, function, and mechanism of action of bacterial ABC proteins are reported, based on phylogenetic comparisons as well as classic biochemical and genetic approaches. The availability of an increasing number of high-resolution structures has provided a valuable framework for interpretation of recent studies, and realistic models have been proposed to explain how these fascinating molecular machines use complex dynamic processes to fulfill their numerous biological functions. These advances are also important for elucidating the mechanism of action of eukaryotic ABC proteins, because functional defects in many of them are responsible for severe human inherited diseases.
Potential Role of Sponge Spicules in Influencing the Silicon Biogeochemistry of Florida Lakes
Authors: Conley Daniel J. , Schelske Claire L.
Published: June 2008

Amorphous silica, e.g. biogenic silica (BSi), contained in diatoms and in sponge spicules was estimated by time course extraction from surficial sediment samples of 82 Florida lakes. Separation of diatom BSi from sponge BSi was based on the observation that diatoms completely dissolve within 2 h of digestion at 85 °C in 1% Na2CO3 whereas sponge spicules, which are generally larger than diatoms, take longer to dissolve. Sponge samples from four lakes in northern Wisconsin ranged widely in the time required to dissolve completely (1.5–12 h), but no significant differences were observed in the rates of dissolution among the lakes. In Florida lake sediments, diatom BSi averaged 49.2 (± 48.4) mg∙g−1 and sponge BSi averaged 31.5 (± 35.8) mg∙g−1, with sponge BSi comprising on average 40% of the total amorphous silica extracted. The procedure for separating diatom BSi from sponge BSi underestimates sponge BSi because smaller and/or lightly silicified components of sponges are completely dissolved early in the digestion. However, because sponge spicules comprise a significant fraction of total amorphous silica extracted, we hypothesize that sponge spicules, which on average are larger than diatoms and require a longer time for complete dissolution, may constitute an important sink for BSi in Florida lakes.
Quantitative Dietary Lysine Requirement of Atlantic Salmon (Salmo salar) Fingerlings
Authors: Anderson J. Stewart , Lall Santosh P. , Anderson Derek M. , McNiven Mary A.
Published: June 2008

Triplicate groups of Atlantic salmon (Salmo salar) fingerlings, initial mean weight 4.7 ± 0.2 g, were fed to satiation diets containing 1.24, 1.76, 1.90, 2.19, 2.45, 2.68, and 2.94% lysine and 24.1 MJ of gross energy per kilogram of diet (dry matter basis, DMB) for 70 d. The fish were reared in brackish water (10 ppt) at a temperature of 15 ± 0.9 °C on a 12-h photoperiod. The dietary requirement for lysine, estimated by broken-line regression of growth against dietary lysine level (DMB), was 1.99 ± 0.11%, or 3.98% of the protein when protein was 50.0% of the diet. A dietary lysine requirement of 1.84 ± 0.16% (DMB) was estimated from broken-line regression of expired 14CO2 (following an intraperitoneal injection of L-[U – 14C]lysine) against dietary lysine concentration. Except for loss of appetite, resulting in low food intake and depressed growth, no nutritional deficiency signs were observed in fish fed a lysine-deficient diet for 140 d.
Evidence for Inheritance of Age of Maturity in Chinook Salmon (Oncorhynchus tshawytscha)
Authors: Hankin David G. , Nicholas Jay W. , Downey Timothy W.
Published: June 2008

We report results of age-specific mating experiments carried out with chinook salmon (Oncorhynchus tshawytscha) at Elk River Hatchery, Oregon. Our analysis of returns from these experiments includes assessment of the marine growth of progeny, and we also account for the negative bias on mean age of returning mature progeny that is a consequence of troll fishery harvest of immature salmon. Results suggest that (a) heritability of age of maturity is relatively high in this species (calculated h2 were 0.49–0.57 and 0.39–0.41 for males and females, respectively), (b) inheritance of age of maturity of females appears to be independent of age of male parent, and (c) for a given parental age, "faster-growing" progeny generally mature at younger ages, but (d) progeny from older parents are not generally smaller at age than progeny from younger parents. Inheritance of age of maturity therefore cannot be a simple reflection of inheritance of growth rate. We tentatively propose the existence of heritable minimum threshold lengths that differentially trigger maturation according to age and sex of parents. We also consider the significance of these experiments for artificial propagation of this species.
Differential Predation by Chaoborus americanus on Males and Females of Two Species of Diaptomus
Authors: Blais Jules M. , Maly Edward J.
Published: June 2008

Feeding experiments were performed to determine relative feeding rates of fourth-instar Chaoborus americanus larvae (Diptera) on both sexes of two calanoid copepod species, Diaptomus leptopus and D. minutus. Feeding rates, using a single prey type, showed that predation rates by Chaoborus on female D. minutus were highest, followed by male D. minutus, male D. leptopus, and female D. leptopus, respectively, when exposed to Chaoborus individually. Selectivity experiments with the four prey types made available simultaneously confirmed this pattern. Prey sizes and swimming speeds were determined, and both strike efficiency and handling time of Chaoborus were measured. Data suggested that selection between prey species was determined primarily by prey size whereas selection between sexes was determined primarily by differential swimming speed.
Groundwater microbiological quality in Canadian drinking water municipal wells
Authors: Locas Annie , Barthe Christine , Margolin Aaron B. , Payment Pierre
Published: June 2008

To verify previous conclusions on the use of bacterial indicators suggested in regulations and to investigate virological quality of groundwater, a 1-year study was undertaken on groundwater used as a source of drinking water in 3 provinces in Canada. Raw water from 25 municipal wells was sampled during a 1-year period for a total of 167 samples. Twenty-three sites were selected on the basis of their excellent historical bacteriological water quality data, and 2 sites with known bacteriological contamination were selected as positive controls. Water samples were analyzed for general water quality indicators (aerobic endospores, total coliforms), fecal indicators ( Escherichia coli , enterococci, somatic and male-specific coliphages), total culturable human enteric viruses (determined by cell culture and immunoperoxidase), noroviruses (analyzed by reverse-transcriptase – polymerase chain reaction (RT–PCR)), adenovirus types 40 and 41 (analyzed by integrated cell culture (ICC) – PCR), and enteroviruses and reoviruses types 1, 2, and 3 (analyzed by ICC–RT–PCR). General water quality indicators were found very occasionally at the clean sites but were frequently present at the 2 contaminated sites. Only one of 129 samples from the 23 clean sites was positive for enterococci. These results confirm the value of raw water quality historical data to detect source water contamination affecting wells that are vulnerable. Samples from the 2 contaminated sites confirmed the frequent presence of fecal indicators: E. coli was found in 20/38 samples and enterococci in 12/38 samples. Human enteric viruses were not detected by cell culture on MA-104 cells nor by immunoperoxidase detection in any sample from the clean sites but were found at one contaminated site. By ICC–RT–PCR and ICC–PCR, viruses were found by cytopathic effect in one sample from a clean site and they were found in 3 samples from contaminated sites. The viruses were not detected by the molecular methods but were confirmed as picornaviruses by electron microscopy. Noroviruses were not detected in any samples. The results obtained reinforce the value of frequent sampling of raw water using simple parameters: sampling for total coliforms and E. coli remains the best approach to detect contamination of source water by fecal pollutants and accompanying pathogens. The absence of total coliforms at a site appears to be a good indication of the absence of human enteric viruses.
EXTENDED CRITICAL SITUATIONS: THE PHYSICAL SINGULARITY OF LIFE PHENOMENA
Authors: BAILLY FRANCIS , LONGO GIUSEPPE
Published: June 2008

In this paper, we propose to consider living systems as "coherent critical structures," though extended in space and time, their unity being ensured through global causal relations between levels of organization (integration/regulation). This may be seen as a further contribution to the large amount of work already done on the theme of self-organized criticality. More precisely, our main physical paradigm is provided by the analysis of "phase transitions," as this peculiar form of critical state presents interesting aspect of emergence: the formation of extended correlation lengths and coherence structures, the divergence of some observables with respect to the control parameter(s), etc…. However, the "coherent critical structures" which are the main focus of our work cannot be reduced to existing physical approaches, since phase transitions, in physics, are treated as "singular events," corresponding to a specific well-defined value of the control parameter. Whereas our claim is that in the case of living systems, these coherent critical structures are "extended" and organized in such a way that they persist in space and time. The relation of this concept to the theory of autopoiesis, as well as to various forms of teleonomy, often present in biological analyses, will be also discussed.
BOX-COUNTING ANALYSIS OF MICROGLIA FORM IN SCHIZOPHRENIA, ALZHEIMER'S DISEASE AND AFFECTIVE DISORDER
Authors: KARPERIEN A. L. , JELINEK H. F. , BUCHAN A. M.
Published: June 2008

In pathological brain, a variety of morphological forms exist that reflect differences in functional requirements. To better understand microglia function in neurological disease, it is important to identify and quantify microglia morphology associated with specific neuropathologies. Traditional feature parameters such as area or cell diameter are not sufficient. In this study microglia were quantified by the box-counting fractal dimension (DB). One hundred and four cells from post-mortem tissue were analyzed comprising cells of controls, Alzheimer's disease, schizophrenia and affective disorder. The DBwas significantly different from the control (1.36) compared to schizophrenia (1.41), Alzheimer's disease (1.41) and affective disorder (1.43) with p < 0.01. Thus fractal analysis provides a useful quantitative and objective measure of microglial form associated with normal function and diverse neuropathology. The distribution of fractal dimensions associated with microglia structure and activation with disease progression also differs, suggesting a different etiology for these diseases.
INTERSECTIONS OF SELF-SIMILAR SETS
Authors: MCCLURE MARK
Published: June 2008

We study sets of the form T ∩ g(T), where T is self-similar and g is a bijection. Under certain assumptions, this intersection may be described using a digraph IFS.