Health status in the ambulance services: a systematic review

BACKGROUND: Researchers have become increasingly aware that ambulance personnel may be at risk of developing work-related health problems. This article systematically explores the literature on health problems and work-related and individual health predictors in the ambulance services. METHODS: We identified the relevant empirical literature by searching several electronic databases including Medline, EMBASE, PsychINFO, CINAHL, and ISI Web of Science. Other relevant sources were identified through reference lists and other relevant studies known by the research group. RESULTS: Forty-nine studies are included in this review. Our analysis shows that ambulance workers have a higher standardized mortality rate, higher level of fatal accidents, higher level of accident injuries and a higher standardized early retirement on medical grounds than the general working population and workers in other health occupations. Ambulance workers also seem to have more musculoskeletal problems than the general population. These conclusions are preliminary at present because each is based on a single study. More studies have addressed mental health problems. The prevalence of post-traumatic stress symptom caseness was > 20% in five of seven studies, and similarly high prevalence rates were reported for anxiety and general psychopathology in four of five studies. However, it is unclear whether ambulance personnel suffer from more mental health problems than the general working population. CONCLUSION: Several indicators suggest that workers in the ambulance services experience more health problems than the general working population and workers in other health occupations. Several methodological challenges, such as small sample sizes, non-representative samples, and lack of comparisons with normative data limit the interpretation of many studies. More coordinated research and replication are needed to compare data across studies. We discuss some strategies for future research

Analysis of Marker-Defined HNSCC Subpopulations Reveals a Dynamic Regulation of Tumor Initiating Properties

Head and neck squamous carcinoma (HNSCC) tumors carry dismal long-term prognosis and the role of tumor initiating cells (TICs) in this cancer is unclear. We investigated in HNSCC xenografts whether specific tumor subpopulations contributed to tumor growth. We used a CFSE-based label retentions assay, CD49f (α6-integrin) surface levels and aldehyde dehydrogenase (ALDH) activity to profile HNSCC subpopulations. The tumorigenic potential of marker-positive and -negative subpopulations was tested in nude (Balb/c nu/nu) and NSG (NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ) mice and chicken embryo chorioallantoic membrane (CAM) assays. Here we identified in HEp3, SQ20b and FaDu HNSCC xenografts a subpopulation of G0/G1-arrested slow-cycling CD49fhigh/ALDH1A1high/H3K4/K27me3low subpopulation (CD49f+) of tumor cells. A strikingly similar CD49fhigh/H3K27me3low subpopulation is also present in primary human HNSCC tumors and metastases. While only sorted CD49fhigh/ALDHhigh, label retaining cells (LRC) proliferated immediately in vivo, with time the CD49flow/ALDHlow, non-LRC (NLRC) tumor cell subpopulations were also able to regain tumorigenic capacity; this was linked to restoration of CD49fhigh/ALDHhigh, label retaining cells. In addition, CD49f is required for HEp3 cell tumorigenicity and to maintain low levels of H3K4/K27me3. CD49f+ cells also displayed reduced expression of the histone-lysine N-methyltransferase EZH2 and ERK1/2phosphorylation. This suggests that although transiently quiescent, their unique chromatin structure is poised for rapid transcriptional activation. CD49f− cells can “reprogram” and also achieve this state eventually. We propose that in HNSCC tumors, epigenetic mechanisms likely driven by CD49f signaling dynamically regulate HNSCC xenograft phenotypic heterogeneity. This allows multiple tumor cell subpopulations to drive tumor growth suggesting that their dynamic nature renders them a “moving target” and their eradication might require more persistent strategies

Vitalism in contemporary chiropractic: a help or a hinderance?

Background: Chiropractic emerged in 1895 and was promoted as a viable health care substitute in direct competition with the medical profession. This was an era when there was a belief that one cause and one cure for all disease would be discovered. The chiropractic version was a theory that most diseases were caused by subluxated (slightly displaced) vertebrae interfering with “nerve vibrations” (a supernatural, vital force) and could be cured by adjusting (repositioning) vertebrae, thereby removing the interference with the body’s inherent capacity to heal. DD Palmer, the originator of chiropractic, established chiropractic based on vitalistic principles. Anecdotally, the authors have observed that many chiropractors who overtly claim to be “vitalists” cannot define the term. Therefore, we sought the origins of vitalism and to examine its effects on chiropractic today. Discussion: Vitalism arose out of human curiosity around the biggest questions: Where do we come from? What is life? For some, life was derived from an unknown and unknowable vital force. For others, a vital force was a placeholder, a piece of knowledge not yet grasped but attainable. Developments in science have demonstrated there is no longer a need to invoke vitalistic entities as either explanations or hypotheses for biological phenomena. Nevertheless, vitalism remains within chiropractic. In this examination of vitalism within chiropractic we explore the history of vitalism, vitalism within chiropractic and whether a vitalistic ideology is compatible with the legal and ethical requirements for registered health care professionals such as chiropractors. Conclusion: Vitalism has had many meanings throughout the centuries of recorded history. Though only vaguely defined by chiropractors, vitalism, as a representation of supernatural force and therefore an untestable hypothesis, sits at the heart of the divisions within chiropractic and acts as an impediment to chiropractic legitimacy, cultural authority and integration into mainstream health care

Synthesis and Structural Characterization of [Te{(SePPh)₂N}₂] and [4-MeO[PhTe{(SPPh₂)₂N}]₂

Reaction of K[(SePPh2)(2)N] with [Te(tu)4]Cl-2 (tu = thiourea) in methanol gave [Te{(SePPh2)(2)N}(2)] (1), while reaction of K[(SPPh2)(2)N] with 4-MeOPhTeCl3 in methanol gave [4-MeOPhTe-{(SPPh2)(2)N}](2), (2). The crystals of 1 are triclinic and contain centrosymmetric molecules. The ligands are bidentate and form a true square planar Te(ll) complex: with TeSe4 coordination. For 2, the crystals ave also triclinic, and the dimeric molecules are centrosymmetric. Each dithiolate ligand bridges the two Te(ll) atoms; the result is a T-shaped coordination around each tellurium atom. A tendency to weak Te-Te bonding across the ring-formed dimer roughly in the direction of the missing fourth ligand in a potential square planar tellurium coordination sphere is also found [Te-Te = 3.761 (1) Angstrom]. In 1, the Te-Se bonds have an average length of 2.797 Angstrom. The Te-S bonds in 2 ave quite asymmetric with Te(1)-S(1) = 2.551 (3) Angstrom and Te(1)-S(2a) = 2.873 (3) Angstrom, while Te(1)-C(1) = 2.10 (1) Angstrom. (C) 1998 John Wiley &amp; Sons, Inc.</p

A Cu4S model for the nitrous oxide reductase active sites supported only by nitrogen ligands

To model the (His)7Cu4Sn (n = 1 or 2) active sites of nitrous oxide reductase, the first Cu4(μ4-S) cluster supported only by nitrogen donors has been prepared using amidinate supporting ligands. Structural, magnetic, spectroscopic, and computational characterization is reported. Electrochemical data indicates that the 2-hole model complex can be reduced reversibly to the 1-hole state and irreversibly to the fully reduced state

Cyclosiloxane sandwich complexes of a lanthanide metal: Na-6{[(C6H5SiO2)(8)](2)Nd-4(mu(4)-O)}

The oligocyclosiloxane cluster ('sandwich') complex of Nd3+, Na-6{[(C6H5SiO2)(8)]Nd-2(4)(mu(4)-O)} has been prepared and characterized by analyses, infrared spectra, single crystal X-ray diffraction, magnetic susceptibility, conductivity and cyclic voltammetry. The mu(4)-O2- anion is in a square planar coordination environment. Electrochemical studies identify the cluster core as a moiety with a delocalized electron system

SUPRAMOLECULAR COMPLEXATION OF N-ALKYL- AND N,N &apos;-DIALKYLPIPERAZINES WITH CUCURBIT[6]URIL IN AQUEOUS SOLUTION AND IN THE SOLID STATE

Complex stoichiometry/composition and degree of oligomerization (oligomeric supramolecular complex formation) of cucurbit[6]uril (CB[6]) with N-alkyl- and N,N&apos;-dialkylpiperazine were investigated in aqueous solutions by means of isothermal titration calorimetry (ITC), ESI-MS, NMR and light scattering measurements. It was found that the complex stability and the degree of oligomerization increase with elongating the alkyl chain attached to the piperazine core. X-ray crystallographic studies revealed a clear correlation between the structure of CB[6]-alkylpiperazine crystals obtained from aqueous solutions and the molecular weight/properties of host-guest oligomers existed in the solution as supramolecular "seeds" of crystal formation.X1111sciescopu