A 12-year Analysis of Malmquist Total Factor Productivity in Dialysis Facilities

This study examined total factor productivity of dialysis facilities in Greece over a 12-year period, using nationally representative panel data. Data Envelopment Analysis (DEA) was used to compute Malmquist productivity indices, which were decomposed into technical efficiency change and technological change. The sample consisted of 73 dialysis facilities operating throughout the entire study period (1993–2004), corresponding to 97.3% and 58.9% of all facilities in the first and last study years respectively. Production variables were nursing staff and dialysis machines (inputs) and dialysis sessions (output). The DEA model was input-oriented allowing for constant returns to scale (CRS). Technical efficiency change was decomposed into scale efficiency change and variable returns to scale (VRS) “pure” technical efficiency change. Mean overall efficiency, throughout the study years, ranged from 39.6 to 63.1% with an all-time average of 56.7%, and only 2–4% of the facilities were fully efficient in each study year. Productivity indices indicated year-by-year progress or regress up to 5%, but the efficiency and technological components differed, in some cases, by as much as 30%. Although interesting subperiod effects were observed, conclusions could not be generalized for the entire study period due to alternating trends. We suggest that preliminary insight to productivity in this sector has been obtained, but particular subperiods must be isolated and further investigated.     

Differentiated thyroid cancer: comparison of therapeutic iodine 131 biological elimination after discontinuation of levothyroxine versus administration of recombinant human thyrotropin

The biological elimination of therapeutic 131I in patients with differentiated thyroid cancer (DTC), post total or near-total thyroidectomy, was compared after withholding levothyroxine suppression against administration of recombinant human thyrotropin without stopping levothyroxine. In 163 patients (group G1) levothyroxine was withheld before 131I therapy: in 138 patients the tumor was limited to the thyroid bed (group G1.1) and in 25 patients metastases were present (group G1.2). A second group of patients (G2; n = 28) received 131I therapy after administration of recombinant human thyrotropin without stopping levothyroxine. Mean retained 131I activity (as a percentage of the administered dose) was 5%-29% (group G1.1), 20%-43% (group G1.2) and 1%-17% (group G2). The effective half-life of 131I was 0.59-0.69 days (group G1.1), 0.87-1.22 days (group G1.2) and 0.38-0.44 days (group G2). In conclusion, the use of recombinant human thyrotropin to prepare patients with thyroid cancer for therapy with 131I shortens its effective half-life and reduces its retained activity compared to preparation with discontinuation of levothyroxine suppression.     

Deregulated overexpression of hCdt1 and hCdc6 promotes malignant behavior

The accurate execution of DNA replication requires a strict control of the replication licensing factors hCdt1 and hCdc6. The role of these key replication molecules in carcinogenesis has not been clarified. To examine how early during cancer development deregulation of these factors occurs, we investigated their status in epithelial lesions covering progressive stages of hyperplasia, dysplasia, and full malignancy, mostly from the same patients. Abnormal accumulation of both proteins occurred early from the stage of dysplasia. A frequent cause of unregulated hCdc6 and hCdt1 expression was gene amplification, suggesting that these components can play a role per se in cancer development. Overexpression of hCdt1 and hCdc6 promoted rereplication and generated a DNA damage response, which activated the antitumor barriers of senescence and apoptosis. Generating an inducible hCdt1 cellular system, we observed that continuous stimulus by deregulated hCdt1 led to abrogation of the antitumor barriers and resulted in the selection of clones with more aggressive properties. In addition, stable expression of hCdc6 and hCdt1 in premalignant papilloma cells led to transformation of the cells that produced tumors upon injection into nude mice depicting the oncogenic potential of their deregulation.     

More aggressive bone marrow screening in retinoblastoma patients is not indicated: the memorial Sloan-Kettering cancer center experience

BACKGROUND: Bone marrow involvement in retinoblastoma patients is rare in the more industrialized nations. The purpose of the current study was to determine the frequency of bone marrow involvement in our series of retinoblastoma patients and to investigate whether the use of four bone marrow aspirates (BMA) and two bone marrow biopsies (BMB) has greater sensitivity for the detection of metastatic disease compared to what has been previously reported. METHODS: Retrospective analysis of the charts of 54 patients with retinoblastoma was performed. We performed 265 BMA, 134 BMB (4 aspirates and 2 biopsies per evaluation), and 67 lumbar punctures (LPs) in 54 patients with retinoblastoma. RESULTS: There were no patients found with bone marrow or cerebrospinal fluid (CSF) involvement at the time of the initial diagnosis. Although no patient died of distant metastases, two patients developed metastatic disease at recurrence, involving the bone marrow and other sites. For these two patients all four aspirates and two biopsies were positive for disease at the time of recurrence. CONCLUSIONS: Despite the use of four BMA and two BMB (as opposed to one bone marrow aspirate that is routinely performed in other centers), the detection of patients with metastatic disease was similar to what has been previously reported. Based on these data more aggressive evaluation of the bone marrow in retinoblastoma patients with clinically limited disease using four aspirates and two biopsies cannot be supported.     

Right coronary ostium agenesis with absence of the right coronary artery: a rare case of non-ST elevation coronary syndrome

We present a case with right coronary ostium agenesis with anomalous origin of the right coronary artery from the left circumflex artery, which caused a non-ST elevation coronary syndrome. A review of the literature indicates this to be an extremely rare case.     

The unexpected anabolic phenotype and extended longevity of skin fibroblasts after chronic glucocorticoid excess

Intense stress can challenge tissue homeostasis and accelerate the ageing process. However, several lines of evidence indicate that repeated mild stresses can have beneficial and even life-prolonging effects. Hypersecretion of glucocorticoids (GC) represents the major hormonal response to stress. Besides its life-sustaining role, GC excess, usually due to several side-effects that promote a "catabolic" phenotype, can be detrimental for several tissues. Cushing's syndrome patients are characterized by chronic endogenous GC excess and consequently at the time of diagnosis they have an atrophic elderly-like skin. Interestingly, when Cushing's syndrome fibroblasts were removed from the high-GC milieu in vivo and cultured in vitro under standard conditions they express an "anabolic" phenotype, i.e. they restore their ability for collagen synthesis, they secrete reduced levels of metalloproteases (MMP-1 and MMP-2) and have an increased proliferative capacity and contractility. Furthermore, these cells exhibit a significant extension of their proliferative lifespan, while they respond better to exogenous stress by producing significantly higher levels of heat-shock protein-70 (HSP70). These results imply that long-term hypercortisolism in vivo can have beneficial consequences on fibroblast physiology in vitro.