Longitudinal trends in laboratory test utilization at a large tertiary care university hospital in Sweden

Background

The aim of the study was to describe and evaluate longitudinal trends in laboratory test utilization over a 7-year period from 2002 to 2008.

Method

Retrospective study using test request data from the Clinical Chemistry and Pharmacology Laboratory at Akademiska Sjukhuset, a large tertiary care university hospital in Sweden. Changes in test utilization, charges, and expenditures during the study period were used as main outcome measures.

Results

Laboratory test utilization increased by over 70%, with a mean annual increase of 9.3% during the study period. After adjustment for inflation, the laboratory expenditures increased by 20.2% during the study period but represented only approximately 2.0% of the hospital''s total expenditure in 2008. The test menu comprised 663 tests in 2008, an increase by 146% from 2002. The mean inflation-adjusted unit price charged per test increased from €34.9 to €37.5 during the study period. The top 10, 20, and 30 tests accounted for, on average, 46.9%, 66.9%, and 75.5% of the total test volume during the study period, and 47.8%, 66.4%, and 75.7% of the total test volume in 2008. In 2008, 10 analyses, i.e. 1.5% of the number of tests on the menu, accounted for almost half the number of generated test results.

Conclusions

The total number of generated test results increased by over 70% in less than a decade. Even so, the laboratory''s share of the hospital''s total expenditure remained low and virtually unchanged. A very small number of tests accounted for a disproportionately large share of the total number of generated test results.     

Irradiation causes acute and long-term spermatogonial depletion in cultured and xenotransplanted testicular tissue from juvenile nonhuman primates

Infertility is a serious late effect in childhood cancer survivors. Little is known about acute irradiation effects in immature primate testis. Radiation defects have previously only been studied in postpubertal primates. Here we use the juvenile rhesus monkey as a preclinical model. We expose fragments of testicular tissue to 0, 0.5, 1.0, and 4.0 Gy irradiation in vitro. We then maintain the fragments in organ culture for 24-48 h or xenograft the fragments into nude mice for 4 months. Histological endpoints were determined to explore the cellular responses to the irradiation. At the highest dose, irradiation provoked an acute depletion of A-spermatogonia and a rise of apoptotic germ and Sertoli cells in organ culture. A dose-dependent decrease in the number of seminiferous tubules containing type A dark and type A pale spermatogonia was observed in irradiated xenografts. The number of Sertoli-cell only tubules increased respectively. Outgrowth of grafts was affected by the 4-Gy dose. Our observations reveal that irradiation evoked an immediate and sustained depletion of A-spermatogonia. We conclude that spermatogonia in the juvenile primate testis are highly sensitive to irradiation and that spermatogonial depletion and cessation of proliferation is an acute response. In contrast to adult testes, where such damage is immediately visible, this damage in immature testes becomes apparent only when spermatogonial insufficiency leads to spermatogenic failure, and thus infertility, at the onset of puberty. Our methods are applicable to immature human testis and might serve as powerful tool to study irradiation toxicity in the juvenile human testis.     

Ten-year survival and cardiovascular mortality in patients with advanced prostate cancer primarily treated by intramuscular polyestradiol phosphate or orchiectomy

BACKGROUND: The aim of the study was to evaluate overall and prostate cancer (PCa) specific survival with special attention to cardiovascular (CV) mortality in patients primarily treated by parenteral polyestradiol phosphate (PEP) 240 mg/month or with orchiectomy (OE), taking into account the effect of pretreatment diseases and medication, and later PCa therapies. METHODS: The present Finnprostate 6 study (10-year follow-up) consisted of 244 patients with locally advanced PCa (T3-4 M0) and 200 patients with metastatic PCa (T1-4 M1). Patients were randomized to OE or PEP therapy. The T3-4 M0 and T1-4 M1 patients were analyzed separately. RESULTS: There was no difference in overall or PCa specific survival between the primary therapy groups in T3-4 M0 or T1-4 M1 patients. In the T3-4 M0 patients the primary treatment (PEP vs. OE) was statistically significantly associated with a risk of CV deaths (P = 0.001). Such an association was not found in the T1-4 M1 patients. CONCLUSIONS: The primary PEP and OE therapies are equal in terms of overall and PCa specific survival in patients with T3-4 M0 or T1-4 M1 disease. In T3-4 M0 patients PEP increases the risk of CV deaths compared to OE but not in T1-4 M1 patients.     

Neuropeptide Y receptor-specifically modulates human neutrophil function

Despite a continuously growing body of evidence highlighting the role of NPY in the immune system, surprisingly little is known about its ability to alter human leukocyte function. We therefore set out to examine NPY receptor expression and functional effects of NPY in freshly isolated human neutrophils. Our results not only demonstrate for the first time the presence of specific NPY receptors on human neutrophils, but also unveil of how these receptors differentially modulate critical functions of neutrophils such as phagocytosis of bacteria as well as the release of reactive oxygen species.     

Epstein-Barr virus encephalitis presenting with a tumor-like lesion in an immunosuppressed transplant recipient

Epstein-Barr virus (EBV) associated central nervous system (CNS) infection is a rare disease. We report an atypical manifestation of EBV encephalitis initially presenting with a tumor-like lesion of the optic tract in an immunocompromised patient 8 years after a combined kidney and pancreas transplantation had been performed. Polymerase chain reaction (PCR) in the cerebrospinal fluid (CSF) and antibody testing confirmed the diagnosis of EBV encephalitis, most likely as a consequence of a reactivated persistent EBV infection. After cessation of the immunosuppressive therapy and induction of treatment with ganciclovir, clinical and magnetic resonance imaging (MRI) findings rapidly improved.     

Effects of chronic rosiglitazone therapy on gene expression in human adipose tissue in vivo in patients with type 2 diabetes

OBJECTIVE: The aim of this study was to compare effects of therapeutic doses of rosiglitazone and metformin on expression of 50 genes in human adipose tissue in vivo. METHODS: Twenty patients with diet-treated type 2 diabetes (13 women, seven men) were randomized to receive either rosiglitazone (n = 9; 8 mg/d) or metformin (n = 11; 2 g/d) for 16 wk. Subcutaneous adipose tissue biopsies were performed before and after treatment. Expression of 50 genes, previously shown to be altered by thiazolidinediones in experimental models, was quantified by real-time PCR and normalized to two housekeeping genes. RESULTS: Rosiglitazone, but not metformin, treatment increased expression of genes involved in triacylglycerol storage [e.g. stearyl-CoA desaturase (3.2-fold), CD36 (1.8-fold)], structural genes [e.g. alpha-1 type-1 procollagen (1.7-fold) and GLUT4 (1.5-fold)], and decreased expression of inflammation-related genes [e.g. IL-6 (0.6-fold), chemokine (C-C motif) ligand 3 (0.4-fold)], 11beta-hydroxysteroid dehydrogenase 1 (0.6-fold), and resistin (0.3-fold) (all P < 0.05). CONCLUSIONS: These results suggest that the insulin-sensitizing action of rosiglitazone involves remodeling of human adipose tissue to reduce inflammation and promote lipid storage. Furthermore, we show some important differences between thiazolidinedione action in human adipose tissue and experimental models.     

Large Oncosomes in Human Prostate Cancer Tissues and in the Circulation of Mice with Metastatic Disease

Oncosomes are tumor-derived microvesicles that transmit signaling complexes between cell and tissue compartments. Herein, we show that amoeboid tumor cells export large (1- to 10-μm diameter) vesicles, derived from bulky cellular protrusions, that contain metalloproteinases, RNA, caveolin-1, and the GTPase ADP-ribosylation factor 6, and are biologically active toward tumor cells, endothelial cells, and fibroblasts. We describe methods by which large oncosomes can be selectively sorted by flow cytometry and analyzed independently of vesicles <1 μm. Structures resembling large oncosomes were identified in the circulation of different mouse models of prostate cancer, and their abundance correlated with tumor progression. Similar large vesicles were also identified in human tumor tissues, but they were not detected in the benign compartment. They were more abundant in metastases. Our results suggest that tumor microvesicles substantially larger than exosome-sized particles can be visualized and quantified in tissues and in the circulation, and isolated and characterized using clinically adaptable methods. These findings also suggest a mechanism by which migrating tumor cells condition the tumor microenvironment and distant sites, thereby potentiating advanced disease.Prostate cancer is the second leading cause of cancer-related death in men in Western countries.¹ Understanding the biological aspects of progression to advanced, untreatable prostate cancer and identifying reliable markers to assess disease course before and after therapy remain major clinical challenges.To migrate into surrounding tissues and metastasize, tumor cells undergo a broad range of physical and functional alterations, including cytoskeletal rearrangements and remodeling of the extracellular matrix (ECM).^2,3 Motile tumor cells assume several phenotypes, including a mesenchymal mode, in which the cells are elongated and fibroblast-like, and a distinct amoeboid mode, with less adherent properties and extensive membrane deformation.^4,5 Amoeboid movement through tissue spaces is characteristically rapid and only minimally dependent on repetitive cycles of membrane attachment and retraction to ECM.^6,7 Amoeboid behavior is less understood in molecular terms than mesenchymal motility; however, evidence indicates that this migration mode is driven by Rho GTPase-mediated actomyosin contractility.^4,8,9 A recent study from our group demonstrates that amoeboid behavior can be induced by microtubule instability caused by loss of the formin DIAPH3.¹⁰ Silencing of DIAPH3 in prostate cancer cells and other tumor cell backgrounds results in an abrupt transition to amoeboid behavior, characterized by formation and retraction of bulky membrane protrusions, as well as increased motility, invasiveness, and metastatic potential.¹⁰ We have also shown that prostate cancer cells exhibiting amoeboid behavior release large (approximately 1- to 10-μm diameter) membrane vesicles into the medium from pinched membrane blebs.^10,11 Notably, as demonstrated for the first time, to our knowledge, in the current study, these structures are large enough to be observed by light microscopy and quantified by several methods potentially applicable to clinical practice.The term oncosome has been used to describe a category of tumor-derived microvesicle (TMV) that can propagate oncogenic information, including transfer of signal transduction complexes, across tissue spaces.^12,13 Oncosomes identified in patients with glioblastoma contained a hyperactive, mutated form of epidermal growth factor receptor, which triggered activation of downstream signaling pathways, such as mitogen-activated protein kinase and AKT, in cells that absorbed them.¹² Such a horizontal transfer mechanism can potentially deliver transforming signals of many kinds throughout tissues and even to distant sites.¹² Most TMVs described in the literature are in the approximately 80- to 500-nm-diameter range.^14–16 Because membrane blebbing can produce a type of microvesicle large enough to be detected by methods other than electron microscopy or biochemical isolation, the question we address herein is whether such a large tumor-derived vesicle can be observed and quantified in situ in tumor tissues or in the circulation. The Ras-like small GTP-binding protein ADP-ribosylation factor 6 (ARF6) was recently identified as a regulator of actomyosin-based abscission of protease-loaded vesicles from the plasma membrane of invasive tumor cell lines.¹⁷ This mechanism results in secretion of relatively large, ARF6-enriched vesicles from blebbing cells,¹⁷ suggesting the possibility that large oncosomes might be detected in vivo using antibodies to ARF6 or other informative target proteins.In the present study, we used a series of prostate cancer models to test the hypothesis that large TMVs, termed large oncosomes herein, can be identified and quantified in plasma and tumor tissue. Our findings show that such structures may be a common feature of aggressive prostate cancer, including metastatic cancer in humans and mice; their evaluation can potentially provide information on disease aggressiveness; and their presence in the microenvironment could be functionally involved in metastatic dissemination and lethal biological behavior of human tumors.