Academic health centers in turbulent times: strategies for survival

Given the increasingly turbulent health care environment, the strategic adaptation of academic health centers (AHCs) provides an opportunity to investigate the effects of drastic change on a population of organizations. This article identifies and categorizes the adaptive behavior using existing strategic typologies, while exploring the implications for hospital managers.

Efficient literature searching in diffuse topics: lessons from a systematic review of research on communicating risk to patients in primary care

Using the example of communication about risk in a primary care setting, this paper puts forward a method of developing and evaluating a detailed search strategy for locating the literature for a systematic review of a 'diffuse' subject. The aim of this paper is to show how to develop a search strategy that maximizes both recall and precision while keeping search outputs manageable. Six different databases were used, namely Medline, Embase, PsychLIT, CancerLIT, Cinahl and Social Science Citation Index (SSCI). The searches were augmented by hand-searching, contacting authors, citation searching and reference lists from included papers. Other databases were searched but yielded no extra references for this subject matter. Of the 99 papers included, 80 were indexed on Medline. The Medline search strategy identified 54 of them and the remaining 26 were located on other databases. The 19 further unique references were found using the other databases and methods of retrieval. A combination of several databases must be used to maximize recall and to increase the precision of searches on individual databases, thus improving the overall efficiency of the search.

Survival of Escherichia coli O157 in a soil protozoan: implications for disease

Intra-protozoal growth of bacterial pathogens has been associated with increased environmental survival, virulence and resistance to biocides and antibiotics. Using laboratory microcosms we have shown that Escherichia coli O157 survives and replicates in a common environmental protozoan, Acanthamoeba polyphaga. As protozoa are widely distributed in soils and effluents, they may constitute an important environmental reservoir for transmission of E. coli O157 and other pathogens.

Specialist nurse counsellor interventions at the time of diagnosis of breast cancer: comparing 'advocacy' with a conventional approach

Over recent years, specialist breast care nurses have become increasingly recognized as core members of any breast care team within the UK. Part of the role is to support patients at the highly stressful stage of receiving a diagnosis. This paper describes an 'advocacy' style of nurse counsellor intervention which aims to improve patients' preparation for, and involvement in, the diagnostic consultation and provides a framework for future counselling support. One hundred and three women undergoing surgery following diagnosis of breast cancer or a benign breast lump were supported using either this advocacy intervention or a more conventional model of care. The aim was to identify the most effective and appropriate method of intervening at this important stage. Assessment took place before surgery, with 2-week and 6-month follow-ups, and included the Hospital Anxiety and Depression Scale, Rotterdam Symptom Check List and semi-structured interviews addressing perceived quality of care, involvement in decision-making and psycho-social functioning. Whilst the results of many measures were similar for women in the two intervention groups, qualitative data support the implementation of the advocacy method by the breast care nurse.

Unexplored reservoirs of pathogenic bacteria: protozoa and biofilms

In the natural, industrial, hospital and domestic environments, there are numerous phenotypes of pathogenic microorganisms, which vary considerably in chemical, physical and biological properties. A link exists between survival, resistance and virulence. In particular, surface-adherent biofilms and bacteria living within protozoa pose potential health problems that are unrecognized by conventional laboratory culture methods.

Biomedical applications of accelerator mass spectrometry-isotope measurements at the level of the atom

Accelerator mass spectrometry (AMS) is a nuclear physics technique developed about twenty years ago, that uses the high energy (several MeV) of a tandem Van de Graaff accelerator to measure very small quantities of rare and long-lived isotopes. Elements that are of interest in biomedicine and environmental sciences can be measured, often to parts per quadrillion sensitivity, i.e. zeptomole to attomole levels (10(-21)-10(-18) mole) from milligram samples. This is several orders of magnitude lower than that achievable by conventional decay counting techniques, such as liquid scintillation counting (LSC). AMS was first applied to geochemical, climatological and archaeological areas, such as for radiocarbon dating (Shroud of Turin), but more recently this technology has been used for bioanalytical applications. In this sphere, most work has been conducted using aluminium, calcium and carbon isotopes. The latter is of special interest in drug metabolism studies, where a Phase 1 adsorption, distribution, metabolism and excretion (ADME) study can be conducted using only 10 nanoCurie (37 Bq or ca. 0.9 microSv) amounts or less of 14C-labelled drugs. In the UK, these amounts of radioactivity are below those necessary to request specific regulatory approval from the Department of Health's Administration of Radioactive Substances Advisory Committee (ARSAC), thus saving on valuable development time and resources. In addition, the disposal of these amounts is much less an environmental issue than that associated with microCurie quantities, which are currently used. Also, AMS should bring an opportunity to conduct "first into man" studies without the need for widespread use of animals. Centre for Biomedical Accelerator Mass Spectrometry (CBAMS) Ltd. is the first fully commercial company in the world to offer analytical services using AMS. With its high throughput and relatively low costs per sample analysis, AMS should be of great benefit to the pharmaceutical and biotechnology industries as well as other life science areas.

Second response to immunoglobulin in recurrent Guillain-Barré syndrome

Guillain-Barré, syndrome is the most common paralytic illness among healthy adults. With modern critical care, the mortality has fallen although prolonged hospitalisation and significant morbidity are common. Plasma exchange and intravenous immunoglobulin have only recently been shown to be equally efficacious; the combination of plasma exchange plus intravenous immunoglobulin does not confer additional advantage. Contrary to earlier fears, immunoglobulin use is not associated with an increased relapsed rate. Some patients do benefit from a second course of immunoglobulin in recurrent Guillain-Barré syndrome.

Murine mucopolysaccharidosis type VII: the impact of therapies on the clinical course and pathology in a murine model of lysosomal storage disease

Murine mucopolysaccharidosis type VII (MPS VII) is a lysosomal storage disease caused by a recessively inherited deficiency of the lysosomal enzyme beta-glucuronidase. Affected mice have clinical, biochemical and pathological findings similar to those seen in humans with MPS VII (Sly syndrome), including growth retardation, facial dysmorphism, deafness, behavioural deficits and widespread glycosaminoglycan storage in lysosomes in the viscera, skeleton and brain. This mouse model is a useful tool for the evaluation of the effectiveness and experimental therapies for the MPS disorders. Syngeneic bone marrow transplantation performed in newborn MPS VII animals--before clinical evidence of disease is pronounced--prolongs life, improves hearing and bone growth, and prevents lysosomal storage in many sites, but does not correct the central nervous system disease. Enzyme therapy with beta-glucuronidase from the first days of life does reduce lysosomal storage in the brain in murine MPS VII. The enzyme-replaced mice also have reduced visceral lysosomal storage, impressive normalization of their phenotype and an improved life span. The effectiveness of gene therapy for the treatment of lysosomal storage disease has also been tested using the MPS VII model. When transplanted into MPS VII mice, syngeneic haematopoietic stem cells or mouse skin fibroblasts infected with retrovirus expressing beta-glucuronidase decreased storage, but only in the liver and spleen. Injection of an adenovirus vector expressing beta-glucuronidase into the vitreous of the MPS VII mice reduced storage in the retinal pigment epithelium and corneal endothelium. Intravenous administration of the adenovirus vector transduced with the beta-glucuronidase gene reduced liver and spleen storage and, when instilled into the cerebral ventricles, this viral vector caused beta-glucuronidase production in epithelial cells lining the ventricles. Recently, retroviral vector-corrected MPS VII fibroblasts secreting high levels of beta-glucuronidase were engrafted directly into the brains of adult MPS VII mice with resultant reduction in storage in neurons and glia adjacent to the grafts. Future efforts aimed at prolonging expression of the beta-glucuronidase gene by viral vectors and more precisely directing the therapeutic effect to the skeleton and brain will be important in optimizing treatments for murine MPS VII and extending the results of such therapies to humans with MPS.

A tacrolimus-related immunosuppressant with reduced toxicity

BACKGROUND

Tacrolimus (FK506) has potent immunosuppressive properties reflecting its ability to block the transcription of lymphokine genes in activated T cells through formation of a complex with FK506 binding protein-12, which inhibits the phosphatase activity of calcineurin. The clinical usefulness of tacrolimus is limited, however, by severe adverse effects, including neurotoxicity and nephrotoxicity. Although this toxicity, like immunosuppression, appears mechanistically related to the calcineurin inhibitory action of the drug, a large chemistry effort has been devoted to search for tacrolimus analogs with reduced toxicity but preserved immunosuppressive activity that might have enhanced therapeutic utility.

METHODS

Here, we report on the identification of such an analog, which was synthetically derived from ascomycin (ASC), the C21 ethyl analog of tacrolimus, by introducing an indole group at the C32 position. The profile of biological activity of indolyl-ASC was characterized in rodent models of immunosuppression and toxicity.

RESULTS

Indolyl-ASC was found to exhibit an immunosuppressive potency equivalent to that of tacrolimus in T-cell activation in vitro and in murine transplant models, even though indolyl-ASC bound about 10 times less to intracellular FK506 binding protein-12 than tacrolimus or ASC. Further evaluation of indolyl-ASC revealed that it is threefold less potent than tacrolimus in inducing hypothermia, a response that may reflect neurotoxicity, and in causing gastrointestinal transit alterations in mice. Moreover, indolyl-ASC was at least twofold less nephrotoxic than tacrolimus upon 3-week oral treatment in rats.

CONCLUSIONS

Altogether, these data indicate a modest but definite improvement in the therapeutic index for indolyl-ASC compared with tacrolimus in rodent models.

Overexpression of the angiogenic factor platelet-derived endothelial cell growth factor/thymidine phosphorylase in psoriatic epidermis

Considerable evidence indicates that the microvascular changes observed in psoriasis are a result of angiogenesis. Vascular proliferation is driven by the local production of molecules which have angiogenic activity. Platelet-derived endothelial cell growth factor/thymidine phosphorylase (PDECGF/TP) is a potent angiogenic factor active in in vivo angiogenesis assays and overexpressed in several tumour types. We have demonstrated by ribonuclease protection analysis a consistently high degree of PDECGF/TP mRNA production in lesional psoriatic skin, while immunohistochemical studies revealed strong PDECGF/TP immunoreactivity in lesional epidermis, with nuclear staining present in basal keratinocytes and cytoplasmic immunoreactivity in suprabasal layers. Non-lesional skin showed minimal PDECGF/TP mRNA production and weak epidermal immunostaining. These results indicate a potential role for PDECGF/TP in the pathophysiology of psoriasis, and reveal a target for antiangiogenesis therapy in the treatment of this disease.

Endothelin-1 does not contribute to ischemia/reperfusion-induced vasoconstriction in skeletal muscle

The experiment reported was designed to investigate whether endothelin-1 (ET-1) contributes to vasospasm and poor perfusion during the reperfusion after prolonged ischemia in skeletal muscle. Male Sprague-Dawley rats weighting 100 to 120 g were anesthetized with Nembutal. The vascular isolated rat cremaster muscle, coupled with local interarterial infusion, was the model used in this study. The diameters of feeding arterioles and terminal arterioles were measured utilizing intravital microscopy. The number of terminal arterioles with temporary cessation of flow were counted in each cremaster. Group 1: ET-dose response (8 rats)--various concentrations of ET-1 (from 10(-8) M to 10(-5) M) were infused into the cremaster to test whether this muscle was responsive to the agent in a dose-dependent manner. Group 2: ET-antagonist response (12 rats)--PD-142893, 10(-4) M (ETab receptor antagonist) plus ET-1 10(-7) M were infused into the cremaster to test whether vasospasm caused by exogenous ET-1 could be prevented by pretreatment with this specific ETab receptor antagonist. Group 3: ischemia/reperfusion response (12 rats)--PD-142893, 10(-4) M was infused into the cremaster before ischemia (4 hr warm ischemia) and during reperfusion to test whether ETab receptor antagonism was effective in preventing the vasospasm associated with ischemia/reperfusion injury. The results from this study show that a mixed ETab endothelin antagonist, PD-142893, infused before ischemia and during reperfusion at a dose which virtually abolished the vasoconstriction produced by a high concentration of exogenous endothelin-1, had no effect on ischemia/reperfusion-induced vasoconstriction in this model. These results suggest that ET-1 probably does not contribute to the ischemia/reperfusion-induced vasoconstriction and poor reflow in rat skeletal muscle.