Bayesian estimation in NONMEM

Bayesian estimation is a powerful but underutilized tool for answering drug development questions. In this tutorial, the principles of Bayesian model development, assessment, and prior selection will be outlined. An example pharmacokinetic (PK) model will be used to demonstrate the implementation of Bayesian modeling using the nonlinear mixed-effects modeling software NONMEM.

Pharmacometric modeling and machine learning analyses of prognostic and predictive factors in the JAVELIN Gastric 100 phase III trial of avelumab

Avelumab (anti–PD‐L1) is an approved anticancer treatment for several indications. The JAVELIN Gastric 100 phase III trial did not meet its primary objective of demonstrating superior overall survival (OS) with avelumab maintenance versus continued chemotherapy in patients with advanced gastric cancer/gastroesophageal junction cancer; however, the OS rate was numerically higher with avelumab at timepoints after 12 months. Machine learning (random forests, SIDEScreen, and variable‐importance assessments) was used to build models to identify prognostic/predictive factors associated with long‐term OS and tumor growth dynamics (TGDs). Baseline, re‐baseline, and longitudinal variables were evaluated as covariates in a parametric time‐to‐event model for OS and Gompertzian population model for TGD. The final OS model incorporated a treatment effect on the log‐logistic shape parameter but did not identify a treatment effect on OS or TGD. Variables identified as prognostic for longer OS included older age; higher gamma‐glutamyl transferase (GGT) or albumin; absence of peritoneal carcinomatosis; lower neutrophil‐lymphocyte ratio, lactate dehydrogenase, or C‐reactive protein (CRP); response to induction chemotherapy; and Eastern Cooperative Oncology Group performance status of 0. Among baseline and time‐varying covariates, the largest effects were found for GGT and CRP, respectively. Liver metastasis at re‐baseline predicted higher tumor growth. Tumor size after induction chemotherapy was associated with number of metastatic sites and stable disease (vs. response). Asian region did not impact OS or TGD. Overall, an innovative workflow supporting pharmacometric modeling of OS and TGD was established. Consistent with the primary trial analysis, no treatment effect was identified. However, potential prognostic factors were identified.

Use, cost-effectiveness, and end user perspectives of a home solar lighting intervention in rural Uganda: a mixed methods, randomized controlled trial

Energy poverty is prevalent in resource-limited settings, leading households to use inefficient fuels and appliances that contribute to household air pollution. Randomized controlled trials of household energy interventions in low and middle income countries have largely focused on cooking services. Less is known about the adoption and impact of clean lighting interventions. We conducted an explanatory sequential mixed methods study as part of a randomized controlled trial of home solar lighting systems in rural Uganda in order to identify contextual factors determining the use and impact of the solar lighting intervention. We used sensors to track usage, longitudinally assessed household lighting expenditures and health-related quality of life, and performed cost-effectiveness analyses. Qualitative interviews were conducted with all 80 trial participants and coded using reflexive thematic analysis. Uptake of the intervention solar lighting system was high with daily use averaging 8.23 ± 5.30 hours per day. The intervention solar lighting system increased the EQ5D index by 0.025 [95% CI 0.002 - 0.048] and led to an average monthly reduction in household lighting costs by -1.28 [-2.52, -0.85] US dollars, with higher savings in users of fuel-based lighting. The incremental cost-effectiveness ratio for the solar lighting intervention was $2025.72 US dollars per quality adjusted life year (QALY) gained making the intervention cost-effective when benchmarked against the gross domestic product (GDP) per capita in Uganda. Thematic analysis of qualitative data from individual interviews showed that solar lighting was transformative and associated with numerous benefits that fit within a Social Determinants of Health (SDOH) framework. The benefits included improved household finances, improved educational performance of children, increased household safety, improved family and community cohesion, and improved perceived household health. Our findings suggest that household solar lighting interventions may be a cost-effective approach to improve health-related quality of life by addressing SDOH.

Anticipating the future: prognostic tools as a complementary strategy to improve care for patients with febrile illnesses in resource-limited settings

In low-income and middle-income countries, most patients with febrile illnesses present to peripheral levels of the health system where diagnostic capacity is very limited. In these contexts, accurate risk stratification can be particularly impactful, helping to guide allocation of scarce resources to ensure timely and tailored care. However, reporting of prognostic research is often imprecise and few prognostic tests or algorithms are translated into clinical practice.

Here, we review the often-conflated concepts of prognosis and diagnosis, with a focus on patients with febrile illnesses. Drawing on a recent global stakeholder consultation, we apply these concepts to propose three use-cases for prognostic tools in the management of febrile illnesses in resource-limited settings: (1) guiding referrals from the community to higher-level care; (2) informing resource allocation for patients admitted to hospital and (3) identifying patients who may benefit from closer follow-up post-hospital discharge. We explore the practical implications for new technologies and reflect on the challenges and knowledge gaps that must be addressed before this approach could be incorporated into routine care settings.

Our intention is that these use-cases, alongside other recent initiatives, will help to promote a harmonised yet contextualised approach for prognostic research in febrile illness. We argue that this is especially important given the heterogeneous settings in which care is often provided for patients with febrile illnesses living in low-income and middle-income countries.

Dielectrophoresis of gold nanoparticles conjugated to DNA origami structures

DNA nanostructures are promising construction materials to bridge the gap between self-assembly of functional molecules and conventional top-down fabrication methods in nanotechnology. Their positioning onto specific locations of a microstructured substrate is an important task towards this aim. Here we study manipulation and positioning of pristine and of gold nanoparticle-conjugated tubular DNA origami structures using ac dielectrophoresis. The dielectrophoretic behavior was investigated employing fluorescence microscopy. For the pristine origami, a significant dielectrophoretic response was found to take place in the megahertz range, whereas, due to the higher polarizability of the metallic nanoparticles, the nanoparticle/DNA hybrid structures required a lower electrical field strength and frequency for a comparable trapping at the edges of the electrode structure. The nanoparticle conjugation additionally resulted in a remarkable alteration of the DNA structure arrangement. The growth of linear, chain-like structures in between electrodes at applied frequencies in the megahertz range was observed. The long-range chain formation is caused by a local, gold nanoparticle-induced field concentration along the DNA nanostructures, which in turn, creates dielectrophoretic forces that enable the observed self-alignment of the hybrid structures.

Critical appraisal of clinical practice guidelines in pediatric infectious diseases

BACKGROUND

There is a need to critically appraise clinical practice guidelines in order to ensure safe and effective practices are being implemented to optimize patient care. Appraising guidelines within one therapeutic area enable recommendations for improvement during guideline creation and dissemination.

OBJECTIVES

Study objectives were to systematically appraise selected published guidelines used in the treatment of pediatric infectious diseases and to make recommendations for improvement throughout the development and dissemination processes.

SETTING

The study occurred between collaborative academic and practice-based institutions located in Canada and Qatar.

METHODS

A literature search identified guidelines for management of pediatric infectious diseases from 1997 to 2013. Each guideline was appraised by four independent assessors, according to the appraisal of guidelines for research and evaluation II (AGREE II) instrument. Standardized domain scores were calculated for each guideline and pooled. Final endorsements for use in clinical practice were also determined. Inter-rater reliability was assessed using intraclass correlation coefficients.

MAIN OUTCOME MEASURE

Standardized domain scores according to the AGREE II instrument.

RESULTS

Twenty guidelines met inclusion criteria and were appraised. Pooled domain scores were: scope and purpose (69.9), stakeholder involvement (40.1), rigour of development (47.1), clarity of presentation (73.4), applicability (23.7), editorial independence (46.7), and overall assessment (55.8). Two (10%) guidelines were recommended for use without revision, 13 (65%) guidelines were recommended with modifications, and 5 (25%) guidelines were not recommended for implementation into practice. Inter-rater reliability was moderate to good with intra-class correlations of 0.65-0.93 per guideline.

CONCLUSION

The majority of appraised guidelines were moderately rated, with a 25% of guidelines not recommended for use. Strategies for improvement require the involvement of all key stakeholders (caregivers, patients, and allied health professionals), and consideration of facilitators, barriers and resource implications during implementation. Additionally, critical appraisal of guidelines should become standard practice prior to adoption into clinical settings.

Bioinspired self-assembly of tyrosinase-modified silicatein and fluorescent core-shell silica spheres

Inspired by the intermolecular cross-linking of mussel foot proteins and their adhesive properties, tyrosinase has been used to modify recombinant silicatein. DOPA/DOPAquinone-mediated cross-linking and interfacial interactions enhanced both self-assembly of silicatein building blocks and templating of core-shell silica spheres, resulting in fluorescent biomimetic silicatein-silica hybrid mesofibers.

Silicate modulates the cross-talk between osteoblasts (SaOS-2) and osteoclasts (RAW 264.7 cells): inhibition of osteoclast growth and differentiation

It has been shown that inorganic monomeric and polymeric silica/silicate, in the presence of the biomineralization cocktail, increases the expression of osteoprotegerin (OPG) in osteogenic SaOS-2 sarcoma cells in vitro. In contrast, silicate does not affect the steady-state gene expression level of the osteoclastogenic ligand receptor activator of NF-κB ligand (RANKL). In turn it can be expected that the concentration ratio of the mediators OPG/RANKL increases in the presence of silicate. In addition, silicate enhances the growth potential of SaOS-2 cells in vitro, while it causes no effect on RAW 264.7 cells within a concentration range of 10-100 µM. Applying a co-cultivation assay system, using SaOS-2 cells and RAW 264.7 cells, it is shown that in the presence of 10 µM silicate the number of RAW 264.7 cells in general, and the number of TRAP(+) RAW 264.7 cells in particular markedly decreases. The SaOS-2 cells retain their capacity of differential gene expression of OPG and RANKL in favor of OPG after exposure to silicate. It is concluded that after exposure of the cells to silicate a factor(s) is released from SaOS-2 cells that causes a significant inhibition of osteoclastogenesis of RAW 264.7 cells. It is assumed that it is an increased secretion of the cytokine OPG that is primarily involved in the reduction of the osteoclastogenesis of the RAW 264.7 cells. It is proposed that silicate might have the potential to stimulate osteogenesis in vivo and perhaps to ameliorate osteoporotic disorders.

Improved phylogenomic taxon sampling noticeably affects nonbilaterian relationships

Despite expanding data sets and advances in phylogenomic methods, deep-level metazoan relationships remain highly controversial. Recent phylogenomic analyses depart from classical concepts in recovering ctenophores as the earliest branching metazoan taxon and propose a sister-group relationship between sponges and cnidarians (e.g., Dunn CW, Hejnol A, Matus DQ, et al. (18 co-authors). 2008. Broad phylogenomic sampling improves resolution of the animal tree of life. Nature 452:745–749). Here, we argue that these results are artifacts stemming from insufficient taxon sampling and long-branch attraction (LBA). By increasing taxon sampling from previously unsampled nonbilaterians and using an identical gene set to that reported by Dunn et al., we recover monophyletic Porifera as the sister group to all other Metazoa. This suggests that the basal position of the fast-evolving Ctenophora proposed by Dunn et al. was due to LBA and that broad taxon sampling is of fundamental importance to metazoan phylogenomic analyses. Additionally, saturation in the Dunn et al. character set is comparatively high, possibly contributing to the poor support for some nonbilaterian nodes.

[Connection between hyponatriemia and local herpes in an old lady?]

We report the case of a 84 year old patient who developed a syndrome of inappropriate antidiuretic hormone secretion (SIADH) with severe hyponatremia in the context of a localized herpes zoster L1/2. This is a rare but known complication of localized varizella zoster infection. Under water restriction and salt administration the hyponatremia was corrected slowly. One month after hospital discharge the patient showed a normal sodium value without diet.

Use of lipid-lowering agents for the prevention of age-related macular degeneration: a meta-analysis of observational studies

PURPOSE

To examine the effect of lipid-lowering agents in the development of age-related macular degeneration (AMD) through the techniques of meta-analysis.

METHODS

Case-control and cohort studies presenting relative risks and 95% confidence intervals were identified through a literature review. Inclusion was limited to studies where both the exposure of interest (lipid-lowering agents) and outcome (AMD) were explicitly defined. Pooled estimates were computed using the random effects model. To quantify heterogeneity we calculated the proportion of total variance of between study variance using the Ri statistic. The Q statistic for heterogeneity was also calculated.

RESULTS

Eight studies were identified. The pooled relative risk (RR) for all studies was 0.74 (95% CI, 0.55-1.00). When only those studies examining the use of statins were pooled (n=7), the RR was 0.70 (95% CI, 0.48-1.03). Using the Ri statistic, the heterogeneity between studies was found to be 0.85 for all studies and 0.89 for studies examining statins.

CONCLUSION

Lipid-lowering agents, including statins, do not appear to lower the risk of developing AMD, although clinically significant effects cannot be excluded. The use of these agents in the prevention of AMD cannot be recommended until well designed prospective studies with long follow up have demonstrated a benefit.

[Paraduodenal hernia: case report of an operative accidental diagnosis]

We present a case of a 65 year old female patient with diverticulitis. We performed a Hartmann's operation. The left paraduodenal hernia was diagnosed during the procedure and we incised the hernia sack. It was only retrospectively, that we saw the hernia on the preoperative CT scan pictures.

Effects of antihypertensive drug treatments on fracture outcomes: a meta-analysis of observational studies

OBJECTIVE

To quantitatively pool findings from observational studies on the risk of fracture outcomes associated with exposure to five antihypertensive drug classes: angiotensin-converting enzyme (ACE) inhibitors, diuretics (in particular thiazide diuretics), beta-blockers, calcium-channel blockers and alpha-blockers.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Publications listed in the MEDLINE, EMBASE and LILACS databases, the ISI proceedings, and bibliographies of retrieved articles. Sources were searched from the earliest possible dates through December 2005.

REVIEW METHODS

We included case-control and cohort studies presenting relative risks and confidence intervals (CIs) for the association between exposure to antihypertensive agents and fracture outcomes. Data were extracted onto a standardized computer worksheet. Study quality was assessed using a 10-point questionnaire specific to case-control or cohort study design.

RESULTS

Fifty-four studies were identified. Pooled estimates were computed using the software HEpiMA. The pooled relative risk (RR) of any fracture with use of thiazide diuretics was 0.86 (95% CI 0.81-0.92) and 1.14 (95% CI 0.84-1.54) with use of nonthiazide diuretics. There was a statistically significant reduction of any fracture with use of beta-blockers, (RR 0.86, 95% CI 0.70-0.98). The one study with ACE inhibitor data showed protection (RR 0.81, 95% CI 0.73-0.89). No significant associations were found between fractures and exposure to alpha-blockers or calcium-channel blockers.

CONCLUSIONS

Thiazide diuretics and beta-blockers appear to lower the risk of fractures in older adults. However, these agents cannot be recommended as preventive therapies for fractures until data from randomized controlled trials have established their efficacy. Patients who use these inexpensive drugs as treatments for hypertension may also benefit from a reduction in fracture risk.

Cell death in Porifera: molecular players in the game of apoptotic cell death in living fossils

Apoptosis represents the morphological manifestation of programmed cell death and, paradoxically at first sight, it is a prerequisite for metazoan life. Thus, apoptosis is responsible for the demise of cells during many physiological processes. It is also accountable for the death of cells following exposure to countless stimuli. Therefore, it is obvious that apoptosis must be regulated by a complex network of various molecular signaling pathways. Research during the past 20 years has led to the identification of major functional groups of molecules involved in apoptotic pathways. These include members of the Bcl-2 superfamily, members of the TNF family, caspases, and their activators. Yet, the evolutionary conservation of those elements of the apoptotic machinery was only established from nematode to man. Sponges (phylum Porifera) are characterized by a remarkable regeneration capacity and longevity. Furthermore, they represent the phylogenetically oldest still extant metazoan taxon. Thus, research on these living fossils opens a window to the past, to the dawn of metazoan life. It allows us to trace the evolution of programmed cell death and its core components. This review summarizes the key findings and concepts which have emerged from studies of apoptosis in Porifera.

[Fundamental mechanisms of apoptosis in the simplest invertebrates, the Porifera]

Sponges (phylum Porifera) represent the oldest metazoan taxon. Through a variety of molecular biological methods the existence of elaborated mechanisms such as programmed cell death was established in those organisms that are regarded today as living fossils. Among the apoptotic proteins identified in sponges are the key molecules of apoptotic pathways, effectors (caspases, death domain proteins) and regulators (Bcl-2 homologues) of programmed cell death. Furthermore, when introduced in vertebrate cells one sponge anti-apoptotic Bcl-2 homologue displayed its pro-survival function in the heterologous system, confirming the conserved character of apoptotic cell death. Comparing apoptotic elements of both the most ancient and the most recent of all metazoans might elucidate the evolution of programmed cell death and processes involved, such as aging.

The Chemokine Networks in Sponges: Potential Roles in Morphogenesis, Immunity and Stem Cell Formation

Porifera (sponges) are now well accepted as the phylum which branched off first from the common ancestor of all metazoans, the Urmetazoa. The transition to the Metazoa became possible because during this phase, cell-cell as well as cell-matrix adhesion molecules evolved which allowed the formation of a colonial stage of animals. The next prerequisite for the evolution to the Urmetazoa was the establishment of an effective immune system which, flanked by apoptosis, allowed the formation of a first level of individuation. In sponges (with the model Suberites domuncula and Geodia cydonium), the main mediators of the immune responses are the chemokines. Since sponges lack a vascular system and consequently blood cells (in the narrow sense), we have used the term chemokines (in a broad sense) to highlight that the complex network of intercellular mediators initiates besides differentiation processes also cell movement. In the present review, the cDNAs encoding the following chemokines were described and the roles of their deduced proteins during self-self and nonself recognition outlined: the allograft inflammatory factor, the glutathione peroxidase, the endothelial-monocyte-activating polypeptide, the pre-B-cell colony-enhancing factor and the myotrophin as well as an enzyme, the (2-5)A synthetase, which is involved in cytokine response in vertebrates. A further step required to reach the evolutionary step of the integrated stage of the Urmetazoa was the acquisition of a stem cell system. In this review, first markers for stem cells (mesenchymal stem cell-like protein) as well as for chemokines involved in the maintenance of stem cells (noggin and glia maturation factor) are described at the molecular level, and a first functional analysis is approached. Taken together, it is outlined that the chemokine network was essential for the establishment of metazoans, which evolved approximately 600 to 800 million years ago.

Sponge Bcl-2 homologous protein (BHP2-GC) confers distinct stress resistance to human HEK-293 cells

It is established that sponges, the phylogenetically oldest still extant phylum of Metazoa, possess key molecules of the apoptotic pathways, that is members from the Bcl-2 family and a pro-apoptotic molecule with death domains. Here we report on transfection studies of human cells with a sponge gene, GCBHP2. Sponge tissue was exposed to heat shock and tributyltin, which caused an upregulation of gene expression of GCBHP2. The cDNA GCBHP2 was introduced into human HEK-293 cells and mouse NIH-3T3 cells; the stable transfection was confirmed by the identification of the transcripts, by Western blotting as well as by immunofluorescence using antibodies raised against the recombinant polypeptide. HEK-293 cells, transfected with GCBHP2, showed high resistance to serum starvation and tributyltin treatment, compared to mock-transfected cells. In contrast to mock-transfected cells, GCBHP2-transfected cells activated caspase-3 to a lower extent. Thus, sponges contain gene(s) involved in apoptotic pathway(s) displaying their function also in human cells.

Molecular evolution of apoptotic pathways: cloning of key domains from sponges (Bcl-2 homology domains and death domains) and their phylogenetic relationships

Cells from metazoan organisms are eliminated in a variety of physiological and pathophysiological processes by apoptosis. In this report, we describe the cloning and characterization of molecules from the marine sponges Geodia cydonium and Suberites domuncula, whose domains show a high similarity to those that are found in molecules of the vertebrate Bcl-2 superfamily and of the death receptors. The Bcl-2 proteins contain up to four Bcl-2 homology regions (BH). Two Bcl-2-related molecules have been identified from sponges that are provided with two of those regions, BH1 and BH2, and are termed Bcl-2 homology proteins (BHP). The G. cydonium molecule, BHP1_GC, has a putative size of 28,164, while the related sequence from S. domuncula, BHP1_SD, has a M(r) of 24,187. Phylogenetic analyses of the entire two sponge BHPs revealed a high similarity to members of the mammalian Bcl-2 superfamilies and to the Caenorhabditis elegans Ced-9. When the two domains, BH1 and BH2, are analyzed separately, again the highest similarity was found to the members of the Bcl-2 superfamily, but a clearly lower relationship to the C. elegans BH1 and BH2 domains in Ced-9. In unrooted phylogenetic trees the sponge BH1 and BH2 are grouped among the mammalian sequences and are only distantly related to the C. elegans BH domains. The analysis of the gene structure of the G. cydonium BHP showed that the single intron present is located within the BH2 domain at the same position as in C. elegans and rat Bcl-x(L). In addition, a sponge molecule comprising two death domains has been characterized from G. cydonium. The two death domains of the potential proapoptotic molecule GC_DD2, M(r) 24,970, share a high similarity with the Fas-FADD/MORT1 domains. A death domain-containing molecule has not been identified in the C. elegans genome. The phylogenetic analysis revealed that the sponge domain originated from an ankyrin building block from which the mammalian Fas-FADD/MORT1 evolved. It is suggested that the apoptotic pathways that involve members of the Bcl-2 superfamily and of the death receptors are already present in the lowest metazoan phylum, the Porifera.

Increased expression of the potential proapoptotic molecule DD2 and increased synthesis of leukotriene B4 during allograft rejection in a marine sponge

Sponges (Porifera) are a classical model to study the events during tissue transplantation. Applying the 'insertion technique' autografts from the marine sponge Geodia cydonium fuse within 5 days. In contrast, allografts are rejected and destroyed. Here we show that during allograft rejection the cells in the grafts undergo apoptosis; 5 days after transplantation 46% of the cells show signs of apoptosis. In a previous study it was shown that during this process a tumor necrosis factor-like molecule is induced in allo- and xenografts. Molecules grouped to the superfamily of tumor necrosis factor receptors and a series of associated adapter molecules contain the characteristic death domain. Therefore, we screened for a cDNA encoding such a domain. Here we report on the first invertebrate molecule from Geodia cydonium comprising a death domain. The potential proapoptotic molecule DD2, with a calculated Mr of 24 970, possesses in contrast to all known mammalian death domain-containing proteins two such domains with highest similarity to the death domain present in human Fas/APO-1. The expression of this gene is not detectable in control tissue but strongly upregulated in allografts; only very low expression is seen in autografts. Parallel with the increase of the expression of the potential proapoptotic molecule DD2 in allografts the level of LTB4 drastically increases from 2.5 pg/mg of protein (controls) to 389 pg LTB4/mg during a period of 5 days after transplantation; the level of LTB4 in autografts does not change. Very likely in response to inflammatory reactions the LTB4 metabolizing enzyme LTB4 12-hydroxy-dehydrogenase is expressed both in auto- and allografts. These results demonstrate that sponges are provided with apoptotic pathways, similar to those present in deuterostomes and apparently absent in protostomes, which are composed of molecules comprising a death domain. In addition, it is suggested that in sponges LTB4 is one metabolite which is involved in the initiation of apoptosis. It is postulated that the potential proapoptotic effect of LTB4 is prevented in auto-grafts by the expression of the LTB4 12-hydroxy-dehydrogenase.

Induction of heat-shock (stress) protein gene expression by selected natural and anthropogenic disturbances in the octocoral Dendronephthya klunzingeri

Previously it was found that the expression of selected heat-shock proteins is upregulated in corals after exposure to elevated temperature. We published that HSPs are suitable markers in sponges to monitor the degree of environmental stress on these animals. In the present study the heat-shock proteins (HSPs) with a molecular weight of 90 kDa have been selected to prove their potential usefulness as biomarkers under controlled laboratory conditions and in the field. The studies have been performed with the octocoral Dendronephthya klunzingeri4.5-fold higher steady-state level of the respective mRNA. Also animals taken from stressed locations in the field showed an increased expression. The amount of HSP90 protein in D. klunzingeri was found to be strongly increased under thermal stress, or exposure to polychlorinated biphenyl (congener 118), but not after treatment with cadmium. Field studies revealed that samples taken from a nonstressed area have a low level of HSP90, but those collected from locations at which the corals are under physical stress (sedimentation through landfilling) show a high expression of HSP90. It is concluded that the chaperone HSP90 might become a suitable biomarker to monitor environmental stress on corals.

Origin of the interferon-inducible (2'-5')oligoadenylate synthetases: cloning of the (2'-5')oligoadenylate synthetase from the marine sponge Geodia cydonium

In vertebrates cytokines mediate innate (natural) immunity and protect them against viral infections. The cytokine interferon causes the induction of the (2'-5')oligoadenylate synthetase [(2-5)A synthetase], whose product, (2'-5')oligoadenylate, activates the endoribonuclease L which in turn degrades (viral) RNA. Three isoforms of (2-5)A synthetases exist, form I (40-46 kDa), form II (69 kDa), and form III (100 kDa). Until now (2-5)A synthetases have only been cloned from birds and mammals. Here we describe the cloning of the first putative invertebrate (2-5)A synthetase from the marine sponge Geodia cydonium. The deduced amino acid sequence shows signatures characteristic for (2-5)A synthetases of form I. Phylogenetic analysis of the putative sponge (2-5)A synthetase indicates that it diverged first from a common ancestor of the hitherto known members of (vertebrate) (2-5)A synthetases I, (2-5)A synthetases II and III. Moreover, it is suggested that the (2-5)A synthetases II and III evolved from this common ancestor (very likely) by gene duplication. Together with earlier results on the existence of the (2'-5')oligoadenylates in G. cydonium, the data presented here demonstrate that also invertebrates, here sponges, are provided with the (2-5)A system. At present, it is assumed that this system might be involved in growth control, including control of apoptosis, and acquired its additional function in innate immune response in evolutionarily younger animals, in vertebrates.

A homolog of the putative tumor suppressor QM in the sponge Suberites domuncula: downregulation during the transition from immortal to mortal (apoptotic) cells

The activation of components of the transcription factors such as AP-1 or c-jun is essential for a physiological response of metazoan cells during aging. The activity of such proto-oncoproteins is under enzymatic control. The function of c-jun is additionally modulated by the QM protein. Here, we studied the expression of the gene, encoding the QM-like protein in the sponge Suberites domuncula. These animals contain high levels of telomerase in their somatic cells. To understand the switch from telomerase-positive immortal cells to telomerase-negative mortal cells which undergo apoptosis, the expression of the QM-like gene was measured in this system. The cDNA, termed QMSD, encoding the QM-like protein was isolated from S. domuncula; its 642 bp long open reading frame encodes a putative protein, QM-SUBDO, of 24,702 Da. Phylogenetic analysis of the sponge QM-like protein revealed that it is closely related to other metazoan QM polypeptides and distinct from sequences of Eumycota or Viridiplantae. Our investigations demonstrated that in gemmules as well as in untreated tissue the expression of the QM-like gene is significantly higher than in tissue which undergoes induced apoptosis. The level of the QM-like protein even decreases drastically in cells that are induced to apoptosis (e.g. by cadmium). We suggest therefore that one event that is involved in the transition of sponge cells from their immortal telomerase-positive to the mortal telomerase-negative state may be the downregulation of the QM-like protein, a putative tumor suppressor polypeptide.

Prolidase in the Marine Sponge Suberites domuncula: Enzyme Activity, Molecular Cloning, and Phylogenetic Relationship

: The enzyme prolidase hydrolyzes the peptide bond that involves the imino nitrogen of proline or hydroxyproline; hence, it catalyzes the final step in collagen degradation. From mammals it is known that this enzyme plays a major role in the recycling of proline for collagen synthesis and can be considered to be essential for the control of cell growth. The dominant organic exoskeleton in sponges, especially in Demospongiae, is collagen and the collagen-related spongin. Here we demonstrate that crude extracts of the demosponge Suberites domuncula contain prolidase or prolidase-like activity. The complementary DNA encoding the putative prolidase was cloned from a library of the same animal. Two different forms of cDNAs, termed SDPEPD1 and SDPEPD2, were identified, coding for the putative polypeptides PEPD_SD-1 with a molecular mass of 55,805 Da and PEPD_SD-2 with 51,684. Evidence is presented suggesting that the two different transcripts originate from the same gene but are formed by an alternative splicing event. We conclude that demosponges contain the activity as well as the gene for prolidase, a major enzyme involved in collagen metabolism, spicule formation, and cell motility. Phylogenetic analysis revealed that the sponge prolidase branches off first from the common ancestor of metazoan prolidases and later than the yeast prolidase; only distantly related are the bacterial enzymes.

Towards an understanding of the molecular basis of immune responses in sponges: the marine demosponge Geodia cydonium as a model

The phylogenetic position of the phylum Porifera (sponges) is near the base of the kingdom Metazoa. During the last few years, not only rRNA sequences but, more importantly, cDNA/genes that code for proteins have been isolated and characterized from sponges, in particular from the marine demosponge Geodia cydonium. The analysis of the deduced amino acid sequences of these proteins allowed a molecular biological approach to the question of the monophyly of the Metazoa. Molecules of the extracellular matrix/basal lamina, with the integrin receptor, fibronectin, and galectin as prominent examples, and of cell-surface receptors (tyrosine kinase receptor), elements of sensory systems (crystallin, metabotropic glutamate receptor) as well as homologs/modules of an immune system (immunoglobulin-like molecules, scavenger receptor cysteine-rich [SRCR]- and short consensus repeats [SCR]-repeats), classify the Porifera as true Metazoa. As living fossils, provided with simple, primordial molecules allowing cell-cell and cell-matrix adhesion as well as processes of signal transduction as known in a more complex manner from higher Metazoa, sponges also show pecularities not known in later phyla. In this paper, the adhesion molecules presumably involved in the sponge immune system are reviewed; these are the basic adhesion molecules (galectin, integrin, fibronectin, and collagen) and especially the highly polymorphic adhesion molecules, the receptor tyrosine kinase as well as the polypeptides comprising scavenger receptor cysteine-rich (SRCR) and short consensus repeats (SCR) modules. In addition, it is reported that in the model sponge system of G. cydonium, allogeneic rejection involves an upregulation of phenylalanine hydroxylase, an enzyme initiating the pathway to melanin synthesis.

Phenylalanine hydroxylase from the sponge Geodia cydonium: implication for allorecognition and evolution of aromatic amino acid hydroxylases

The prophenoloxidase activating system is a defense system, frequently reported both in protostomes and in deuterostomes. The final product of the phenoloxidase activity is melanin which is ubiquitously present throughout the metazoan kingdom. The melanin synthesis pathway starts with the amino acid [aa] phenylalanine which is converted to tyrosine by the phenylalanine hydroxylase [PAH]. We show that after allo-transplantation in the marine sponge Geodia cydonium PAH is upregulated in the grafts. Enzyme determination studies revealed that PAH activity increases by three-fold two d after transplantation and reaches its maximum after 3d (by 3.7-fold). This finding was supported by determining the steady-state level of the mRNA for PAH. Furthermore the cDNA, encoding this enzyme was isolated from G. cydonium. Its deduced aa sequence encodes a protein of 51 kDa. Alignment studies indicate that the sponge PAH shares the consensus pattern as well as one characteristic pterin-binding site with the biopterin-dependent aromatic amino acid hydroxylases. Phylogenetic analysis of sponge PAH shows that all metazoan PAH fall in one group with the sponge PAH as the oldest member. The related classes of enzymes, the tyrosine hydroxylases and the tryptophan hydroxylases are statistically significantly separated from PAH; the tyrosine hydroxylase diverged as the first class from the common ancestor, a process which was calculated to have occurred 500 million years ago. It is concluded that in the sponge model system G. cydonium allogeneic rejection involves an upregulation of PAH, an enzyme initiating the pathway to melanin synthesis.

Inhibitory effects of extracts from the marine alga Caulerpa taxifolia and of toxin from Caulerpa racemosa on multixenobiotic resistance in the marine sponge Geodia cydonium

The invasive growth of the introduced green alga Caulerpa taxifolia, already affecting the richness and diversity of the littoral ecosystems, has become a major ecological problem in the Mediterranean Sea. Previously, we demonstrated that the water pollutant tributyltin induces apoptosis in tissue of the marine sponge Geodia cydonium at concentrations of 3 μM and higher. Here we show that exposure of G. cydonium to low (non-toxic) concentrations of Caulerpa extract or purified caulerpin (10 μg/ml) together with low doses of tributyltin (1 μM; non-toxic), results in a strong apoptotic effect. Evidence is presented that the enhancement of toxicity of tributyltin by Caulerpa extract is at least partially caused by inhibition of the multixenobiotic resistance (MXR) pump by the algal toxin. Caulerpa extract, as well as caulerpin, strongly enhance the accumulation of the test substrate of MXR, rhodamine B, in the gills of the mussel Dreissena polymorpha, used as a model system for testing MXR-inhibiting potential.

Child development and long-term outcomes: a population health perspective and summary of successful interventions

Studies of socioeconomic gradients in mortality in wealthy societies reveal that they have been persist, and included most of the principal causes of death, even during the era when these principal causes of death have entirely changed. This observation has led to an interest in the ways in which the diversity of conditions of life, unfolding over the life cycle, can become embedded in human biology and subsequently affect health status and vitality. There is evidence that childhood experiences affect subsequent health status (as well as well-being and competence) in profound and long-lasting ways. Conflicting explanatory models of the impact of childhood experiences have been advanced, whose conflicts are political in nature, in that the reflect divergent beliefs about how human potential expresses itself, and, also, about the nature of the obligations which members of society have to one another. Notwithstanding these conflicts, a body of evidence derived from intervention studies in the post-neonatal, preschool, and school age periods suggest that performance in two basic domains of child development, the cognitive and the social-emotional, can be modified in ways which improve health, well-being, and competence in the long-term.

Routine restaurant inspections and education of food handlers: recommendations based on critical appraisal of the literature and survey of Canadian jurisdictions on restaurant inspections and education of food handlers

Inspection of restaurants and education of food handlers are two methods used by regulatory agencies to ensure food served in restaurants is safe to eat. The variation which exists in the implementation of these programs suggests that the programs' effectiveness is lacking or is not clear. Recommendations based on the Community Health Practice Guideline methodology, the results of a critical review of the literature, the results of a survey of practices, and expert opinion were developed. The recommendations include: continuation of routine inspections at a frequency of one to two inspections per year per restaurant and the continuation of education programs. The evidence on which these recommendations are based is scant and more research is needed to ensure programs are needed, effective and efficient.

The evaluation of the effectiveness of routine restaurant inspections and education of food handlers: critical appraisal of the literature

Literature databases were scanned to locate articles pertaining to food handler education and restaurant inspection. Papers which met pre-established criteria, as described in the generic protocol produced by the Community Health Practice Guidelines Project (CHPG), were evaluated by standardized consideration of criteria. Studies were rated on a scale of one to three. There were eight papers related to the intervention of education, four papers dealing with the intervention of restaurant inspection, and one pertaining to both. the evidence presented in the papers regarding the effectiveness of food handler training in improving food establishment sanitation was weak, but it appeared that some training resulted in improved inspection scores. It appeared that inspections were beneficial, although it was not clear whether three or more inspections were better than two. No inspections appeared to result in worse inspection scores.

The evaluation of the effectiveness of routine restaurant inspections and education of food handlers: restaurant inspection survey

To determine restaurant inspection and food handler education practices in Canada, a survey of 141 jurisdictions was conducted. The response rate was 100%. All jurisdictions inspected restaurants, but the frequency of routine inspection varied from none to six or more times per year. The frequency of violations found on routine inspection was associated with foodborne illness. However, the frequency of inspection was not correlated with disease or with violations. Food handler education courses were mandatory in 32% of jurisdictions. Most courses were one to two days. No correlation was found between the numbers of individuals trained in the past year and violations or reported foodborne disease. This lack of reduction in reported foodborne illness may be due to the ecological nature of the survey or to the lack of effectiveness of food handler education or of routine restaurant inspections in reducing violations.

A case-control study of Parkinson's disease in a horticultural region of British Columbia

We compared personal histories of 127 cases and 245 controls to identify possible environmental risk factors for idiopathic parkinsonism (IP). Of our controls, 121 had cardiac disease (CD) and 124 were randomly selected from electoral lists (voters). Using logistic regression and adjusting for sex and age, we ran separate analyses: IP versus CD and IP versus voters. A full occupational history was collected, as was known contact with all pesticides associated with the tree fruit sector of the agricultural industry. We found a significant association between IP and having had an occupation in which exposure through handling or directly contacting pesticides was probable, but no specific chemicals were associated with IP. We conclude that although occupations involving the use of agricultural chemicals may predispose to the development of IP, it seems likely that the pathogenesis is multifactorial rather than related to a specific agent.

Demonstration of cytomegalovirus by polymerase chain reaction after liver transplantation

The polymerase chain reaction (PCR) is a highly sensitive and specific technique for detection of cytomegalovirus DNA. With this method we prospectively analyzed buffy coat leukocytes at weekly intervals over 3 months in 60 patients after liver transplantation (LTX). The PCR results were correlated with the pretransplant donor/recipient CMV antibody status and with the occurrence of CMV-induced disease. Thirty-three of 60 (55%) patients became PCR-positive during their posttransplant course. None of the 27 patients with permanent negative PCRs developed CMV disease. Of 33 patients with positive PCRs, 13 (39%) became ill. CMV disease developed in 9 of 22 (41%) antibody-negative recipients but only in 4 of 38 (10%) seropositive graft recipients. The incidence of CMV disease was 75% (9 of 12 patients) in seronegative recipients who converted to positive PCR results and 19% (4 of 21 patients) in seropositive patients with positive PCR findings. The predictive value of a positive PCR was 75% in seronegative patients but it was low (19%) in seropositive recipients. The predictive value of a negative PCR is 100%. Thus, PCR determinations are useful in identifying patients who will not develop CMV disease and in narrowing down the number of individuals who will become sick. Further, PCR is a helpful tool in the follow-up of patients under antiviral treatment.

Comparison of quadruple immunosuppression after liver transplantation with ATG or IL-2 receptor antibody

Treatment with monoclonal IL-2 receptor antibodies has been successfully used for immunosuppressive induction therapy following organ transplantation in the recent past. The present study was conducted to compare for the first time a cyclosporine-based quadruple immunosuppressive regimen including a monoclonal IL-2 receptor antibody or ATG as induction therapy after orthotopic liver transplantation. In two groups of 33 patients each, postoperative survival, graft biopsies, liver function enzymes, and the clinical courses after OLT were evaluated. Our results indicate that monoclonal IL-2 receptor antibody therapy as part of a quadruple immunosuppressive regimen is better tolerated and is at least as effective as ATG in prevention of allograft rejection following OLT. Furthermore, our data indicate that a slightly better liver function in general and a lower incidence of rejection reactions necessitating treatment could be observed in the group of patients treated with the monoclonal IL-2 receptor antibody. This study provides evidence that monoclonal IL-2 receptor antibody therapy may be a useful tool for the immunosuppressive induction therapy following clinical orthotopic liver transplantation.

Concentrations of organochlorine pesticides in the adipose tissue of British Columbia residents

Adipose tissue from a sample of 41 British Columbians was analyzed for a number of organochlorine pesticides. Pesticide concentrations were very low. Persistent fat-soluble compounds like DDT were found at the highest concentrations, whereas compounds that either quickly metabolize to other forms or are readily excreted were found at low levels or not detected. Data on age, sex, area of residence, occupation, diet and weight were obtained by interview. Increasing age was related to increasing levels of several of the persistent pesticides. Although there were insufficient data for statistical analysis, two individuals with potential occupational exposures had much higher levels of the pesticides than other subjects. Although population-based surveys of these organochlorine pesticides in human tissue may have little value, further study may be warranted for groups known to have had high exposures (e.g. occupationally exposed).

Repeated measurements of pulmonary function following spinal cord injury

Twelve subjects (11 males, 1 female) with complete spinal cord lesion (level of lesion ranging from C4 to T10), with a mean age of 23.5 years participated in pulmonary function testing (PFT). Inspiratory and expiratory flow measurements were made at 2-month intervals from 25 to 351 days post injury. The values were interpolated and extrapolated to common dates to facilitate comparison. The effect of time on pulmonary function was determined by a repeated measures ANOVA. Forced expiratory volume in 1 second (FEV1.0) significantly increased during the course of the study (40%, p < 0.05), but increases in forced vital capacity (FVC) (32.5%) and maximal voluntary ventilation (MVV) (16%) were not statistically significant. Lesion level was found to be correlated (Spearman Product Moment Correlation) with pulmonary function if a single measure was made (r = 0.55 to 0.73), but emerged as a stronger predictor if the average of several repeated PFTs was correlated with lesion level (r = 0.74 to 0.84). In addition, lesion level was not correlated with the amount of improvement attained during the time period studied. We conclude that the time course of recovery of pulmonary function is variable between individuals with spinal cord injuries and can only be weakly predicted by knowledge of the initial value and the lesion level.

Quadruple immunosuppression including a new IL-2-receptor antibody and the incidence of infections after liver transplantation

Immunosuppression is a primary concern after orthotopic liver transplantation (OLT). On the one hand, the graft is at jeopardy through acute or chronic rejection, and on the other, immunosuppression and antirejection therapy increase the risk of infectious complications. Effective immunosuppression therefore should prevent rejections without leading to a high rate of infections, bearing in mind the fact that infections and infection-related complications are the most frequent causes of early death after liver transplantation. With more specific immunosuppression the infectious complications can potentially be minimized. Antithymocyte globulin (ATG) and the first monoclonal antibody OKT3 immunosuppression are non-specific. The replacement of these antibodies in a quadruple immunosuppressive regimen with the new monoclonal IL-2R antibody BT 563 probably reduces the early infection rate. We report on our first experience with BT 563. The incidence of infection was compared with a historical control group with ATG.

Recognizing acute health effects of substitute fungicides: are first-aid reports effective?

Recently, many British Columbia sawmills stopped using traditional chlorophenate anti-sapstain fungicides and substituted 2-(thiocyanomethylthio) benzothiazole (TCMTB) and copper-8-quinolinolate (Copper 8). We conducted a cross-sectional study with two aims: to ascertain which acute health effects, if any, were associated with the use of the substitute fungicides; and to determine the effectiveness of first-aid records as a means of detecting acute health outcomes. Workers in five coastal sawmills were asked to complete a self-administered questionnaire about symptoms considered potentially related and unrelated to fungicide exposure, and about injuries commonly reported in sawmills. In addition, we collected first-aid records from the mills, and asked senior workers to estimate the duration of exposure to fungicides for each job. Symptoms found to be consistently elevated in TCMTB mills included dry skin around the eyes, blood-stained mucus from the nose, nose bleed, peeling skin, burning or itching skin, and skin redness or rash. No symptoms were consistently elevated in the Copper 8 mills. Symptoms related to TCMTB exposure were recorded only 12 times in first-aid logs during the study period (versus 335 questionnaire self-reports). This low symptom-recording frequency may be a function of established patterns of first-aid use in which illness symptoms are reported less frequently than injuries.

Parkinson's disease: a case-control study of occupational and environmental risk factors

We compared personal histories of 57 cases and 122 age-matched controls to identify possible environmental determinants of Parkinson's disease (PD). Odds ratios (OR) adjusted for sex, age, and smoking were computed using stepwise logistic regression. We found a statistically significant increased risk for working in orchards (OR = 3.69, p = 0.012, 95% CI = 1.34, 10.27) and a marginally significant increased risk associated with working in planer mills (OR = 4.11, p = 0.065, 95% CI = 0.91, 18.50). A Fisher's exact test of the association between PD development and (1) paraquat contact, and (2) postural tremor gave statistically significant probability estimates of 0.01 and 0.03, respectively. The relative risk of PD decreased with smoking, an inverse relationship supported by many studies.

A community survey of Parkinson's disease

In a rural community of 80,000 people 69 patients were identified as having a diagnosis of Parkinson's disease. After interview and examination we found that 55 met the generally accepted diagnostic criteria for Parkinson's disease, 4 had possible Parkinson's disease, 6 had essential tremor, 2 had dementia and 2 had other conditions. The patients with Parkinson's disease had clinical and epidemiologic characteristics similar to those of patients in previous, mainly hospital-based, studies. These characteristics included mean age at onset (63 years), frequency rate of dementia (20%) and presence of postural tremor (11%). The pattern of treatment varied, some patients receiving more medication than is usual for the severity of their illness, and some patients receiving less than is usual. Parkinson's disease can be difficult to diagnose and manage because of the clinical variation between patients in presentation and response to treatment.

Reciprocal inhibition following lesions of the spinal cord in man

1. Reciprocal inhibition was studied in normal subjects and patients with spinal cord lesions by stimulating the posterior tibial nerve below the threshold of the soleus alpha-motoneurone axons and recording the changes in firing probability of single tibialis anterior motor units activated by voluntary contraction. A short-latency (about 35 ms) period of decreased firing probability was assumed to represent reciprocal inhibition. 2. For a given stimulus intensity this inhibition was greater in patients with spinal lesions than in normal subjects. 3. The stimulus intensities at which soleus motoneurones and the Ia inhibitory interneurones were brought to threshold provided an estimate of the relative excitability of these two neural populations. In the patients with spinal lesions the Ia inhibitory interneurones were more excitable than soleus motoneurones, whereas in normal subjects the excitabilities were approximately equal. 4. Stimulation of the posterior tibial nerve below the threshold of alpha-motoneurone axons also resulted in a second period of inhibition with a latency of approximately 50 ms. This was less prominent in the patients with spinal cord lesions. 5. It is concluded that transmission through the pathways mediating reciprocal inhibition of flexor muscles during their voluntary contraction is enhanced following a spinal cord lesion in man but that a later inhibitory process is depressed.