Heat load increases the risk of clinical mastitis in dairy cattle.

The study was aimed at assessing heat load-related risk of clinical mastitis (CM) in dairy cows. Records of CM for the years 2014 and 2015 were obtained from a large conventional dairy farm milking about 1,200 Holstein cows in central Italy. A case of CM was defined by the presence of clinical signs and veterinary confirmation. Quarter milk samples were collected and bacteriological investigated for each CM. Etiological agents were identified and classified as environmental or contagious pathogens. Hourly weather data from the nearest weather station were used to calculate heat load index (HLI). Upper and lower thresholds of HLI, at which the animal accumulates or dissipates heat, were settled and used to measure heat load balance through the accumulated heat load (AHL) model. Zero and positive values of AHL indicate periods of thermo-neutral and heat accumulation, respectively. Each case of CM was associated with HLI-AHL values recorded 5 d before the event. The risk of CM was evaluated using a case-crossover design. A conditional logistic regression model was used to calculate the odds ratio and 95% confidence intervals of CM recorded in thermo-neutral (AHL = 0) or heat load (AHL > 0) days, pooled or stratified for pathogen type (environmental or contagious). Classes of AHL as low (<6.5), medium (6.6-34.9), and high (>35) were included in the model. Other variables included in the model were milk yield as liters (<20, 20-30, and >30), days in milk (<60, 60-150, and >150), and parity (1, 2-3, and >3). A total of 1,086 CM cases were identified from 677 cows. Escherichia coli, Streptococcus spp., and Streptococcus uberis were the environmental pathogens isolated with the highest frequency; Staphylococcus aureus prevailed within contagious species. The analysis of pooled data indicated a significant effect of heat load on the occurrence of CM in the contagious pathogen stratum. Higher milk yield, middle and late stage of lactation, and older parity increased the risk of CM under heat load conditions. However, the association between pathogen type and these factors was not clear because the model provided significant odds ratios within all pathogen categories. The present study provided the first evidence of an association between HLI and CM in dairy cattle and suggested the ability of the AHL model to assess the risk of mastitis associated with heat load.

Survival of Mycobacterium avium subsp. paratuberculosis in the intermediate and final digestion products of biogas plants.

AIMS: To evaluate the survival of Mycobacterium avium subsp. paratuberculosis (MAP) during anaerobic digestion (AD), we studied two different biogas plants loaded with manure and slurry from paratuberculosis-infected dairy herds. METHODS AND RESULTS: Both plants were operating under mesophilic conditions, the first with a single digester and the second with a double digester. Mycobacterium avium subsp. paratuberculosis detection was performed by sampling each stage of the process, specifically the prefermenter, fermenter, liquid digestate and solid digestate stages, for 11 months. In both plants, MAP was isolated from the prefermenter stage. Only the final products, the solid and liquid digestates, of the one-stage plant showed viable MAP, while no viable MAP was detected in the digestates of the two-stage plant. CONCLUSIONS: Mycobacterium avium subsp. paratuberculosis showed a significant decrease during subsequent steps of the AD process, particularly in the two-stage plant. We suggest that the second digester maintained the digestate under anaerobic conditions for a longer period of time, thus reducing MAP survival and MAP load under the culture detection limit. SIGNIFICANCE AND IMPACT OF THE STUDY: Our data are unable to exclude the presence of MAP in the final products of the biogas plants, particularly those products from the single digester; therefore, the use of digestates as fertilizers is a real concern related to the possible environmental contamination with MAP.

The effect of heat waves on dairy cow mortality.

This study investigated the mortality of dairy cows during heat waves. Mortality data (46,610 cases) referred to dairy cows older than 24mo that died on a farm from all causes from May 1 to September 30 during a 6-yr period (2002-2007). Weather data were obtained from 12 weather stations located in different areas of Italy. Heat waves were defined for each weather station as a period of at least 3 consecutive days, from May 1 to September 30 (2002-2007), when the daily maximum temperature exceeded the 90th percentile of the reference distribution (1971-2000). Summer days were classified as days in heat wave (HW) or not in heat wave (nHW). Days in HW were numbered to evaluate the relationship between mortality and length of the wave. Finally, the first 3 nHW days after the end of a heat wave were also considered to account for potential prolonged effects. The mortality risk was evaluated using a case-crossover design. A conditional logistic regression model was used to calculate odds ratio and 95% confidence interval for mortality recorded in HW compared with that recorded in nHW days pooled and stratified by duration of exposure, age of cows, and month of occurrence. Dairy cows mortality was greater during HW compared with nHW days. Furthermore, compared with nHW days, the risk of mortality continued to be higher during the 3 d after the end of HW. Mortality increased with the length of the HW. Considering deaths stratified by age, cows up to 28mo were not affected by HW, whereas all the other age categories of older cows (29-60, 61-96, and >96mo) showed a greater mortality when exposed to HW. The risk of death during HW was higher in early summer months. In particular, the highest risk of mortality was observed during June HW. Present results strongly support the implementation of adaptation strategies which may limit heat stress-related impairment of animal welfare and economic losses in dairy cow farm during HW.

Adjuvant chemotherapy with cisplatin and gemcitabine versus chemotherapy at relapse in patients with muscle-invasive bladder cancer submitted to radical cystectomy: an Italian, multicenter, randomized phase III trial.

BACKGROUND: The purpose of the study was to evaluate the benefit of adjuvant chemotherapy (AC) versus surgery alone in patients with muscle-invasive bladder cancer (MIBC). PATIENTS AND METHODS: One hundred and ninety-four patients with pT2G3, pT3-4, N0-2 transitional cell bladder carcinoma were randomly allocated to control (92 patients) or to four courses of AC (102 patients). These latter patients were further randomly assigned to receive gemcitabine 1000 mg/m(2) days 1, 8 and 15 and cisplatin 70 mg/m(2) day 2 or gemcitabine as above plus cisplatin 70 mg/m(2) day 15, every 28 days. RESULTS: At a median follow-up of 35 months, the 5-year overall survival (OS) was 48.5%, with no difference between the two arms [P = 0.24, hazard ratio (HR) 1.29, 95% confidence interval (CI) 0.84-1.99]. Mortality hazard was significantly correlated with Nodes (N) and Tumor (T) stage. The control and AC arms had comparable disease-free survival (42.3% and 37.2%, respectively; P = 0.70, HR 1.08, 95% CI 0.73-1.59). Only 62% of patients received the planned cycles. A significant higher incidence of thrombocytopenia was observed in patients receiving cisplatin on day 2 (P = 0.006). A similar global quality of life was observed in the two arms. CONCLUSION: The study was underpowered to demonstrate that AC with cisplatin and gemcitabine improves OS and disease-free survival in patients with MIBC.

Molecular structure of DNA by scanning tunneling microscopy.

Uncoated DNA molecules marked with an activated tris(l-aziridinyl) phosphine oxide (TAPO) solution were deposited on gold substrates and imaged in air with the use of a high-resolution scanning tunneling microscope (STM). Constant-current and gap-modulated STM images show clear evidence of the helicity of the DNA structure: pitch periodicity ranges from 25 to 35 angstroms, whereas the average diameter is 20 angstroms. Molecular structure within a single helix turn was also observed.

Early Regression of Carotid Intima-Media Thickness after Bariatric Surgery and Its Relation to Serum Leptin Reduction.

PURPOSE: Bariatric surgery (BS) promotes carotid intima-media thickness (C-IMT) regression as early as 6 months post-surgery. To verify whether C-IMT regression occurs even earlier, we aimed at the effect of Roux-en-Y gastric bypass (RYGBP) and biliopancreatic diversion (BPD) on C-IMT 1-2 months and 12 months post-surgery. SUBJECTS/METHODS: Prospective trial. BS was performed on 109 patients either with (RYGBP = 42; BDP = 40) or without type 2 diabetes (RYGBP = 27). Healthy volunteers served as control group. FOLLOW-UP: baseline, 1-2 months, 12 months post-surgery. ENDPOINTS: changes (∆) in C-IMT, weight, body mass index, fat mass, waist and neck circumferences, blood pressure, HbA1c, glucose, insulin, insulin sensitivity [HOMA-IR; OGIS, from meal tolerance test], lipids, C-reactive protein, leptin, adiponectin, MCP-1. RESULTS: All surgery subgroups had similar levels of ∆-C-IMT. C-IMT in the pooled surgery group reduced from [mean (95% confidence interval)] 0.81 (0.77-0.84) mm to 0.66 (0.63-0.69) mm, p < 0.001 [-17.1 (-20.4 to -13.8)%] at 1-2 months, and to 0.63 (0.59-0.66) mm, p < 0.001 [-21.8 (-25.3 to -18.4)%] at 12 months post-surgery. ∆-C-IMT 1-2 months and 12 months post-surgery correlated to baseline C-IMT, and with ∆-leptin at 1-2 months, but not at 12 months post-surgery. In linear regression analysis, ∆-leptin and baseline C-IMT were predictors of ∆-C-IMT 1-2 months post-surgery. CONCLUSIONS: A remarkable C-IMT regression occurred as early as 1-2 months after BS in obese patients either with or without type 2 diabetes, which was associated to the early reduction in leptin, (at least partially) independent of weight loss. Whether this is a causative or correlative association needs further investigation.

Reconstitution of cyclin D1-associated kinase activity drives terminally differentiated cells into the cell cycle.

Terminal cell differentiation entails definitive withdrawal from the cell cycle. Although most of the cells of an adult mammal are terminally differentiated, the molecular mechanisms preserving the postmitotic state are insufficiently understood. Terminally differentiated skeletal muscle cells, or myotubes, are a prototypic terminally differentiated system. We previously identified a mid-G(1) block preventing myotubes from progressing beyond this point in the cell cycle. In this work, we set out to define the molecular basis of such a block. It is shown here that overexpression of highly active cyclin E and cdk2 in myotubes induces phosphorylation of pRb but cannot reactivate DNA synthesis, underscoring the tightness of cell cycle control in postmitotic cells. In contrast, forced expression of cyclin D1 and wild-type or dominant-negative cdk4 in myotubes restores physiological levels of cdk4 kinase activity, allowing progression through the cell cycle. Such reactivation occurs in myotubes derived from primary, as well as established, C2C12 myoblasts and is accompanied by impairment of muscle-specific gene expression. Other terminally differentiated systems as diverse as adipocytes and nerve cells are similarly reactivated. Thus, the present results indicate that the suppression of cyclin D1-associated kinase activity is of crucial importance for the maintenance of the postmitotic state in widely divergent terminally differentiated cell types.

A pharmacokinetic interaction study of docetaxel and cisplatin plus or minus 5-fluorouracil in the treatment of patients with recurrent or metastatic solid tumors.

BACKGROUND: The purpose of this study was to look at the pharmacokinetics of docetaxel, cisplatin-derived platinum and 5-fluorouracil (5-FU), when used in combination, to exclude potential clinically relevant pharmacokinetic interactions. METHODS: Fifteen patients with recurrent or metastatic solid tumors were randomized to receive docetaxel 75 mg/m2 and cisplatin 75 mg/m2 in the first treatment course on day 1 and the same combination plus 5-FU 750 mg/m2/day on days 1-5 in the second course, or the two treatment courses in reversed order. Cycles were repeated every 3 weeks. A pharmacokinetic analysis was performed during the first two cycles. RESULTS: Full pharmacokinetic data was available for 12 of the 15 patients. Treatment was tolerated well, with frequency of toxicity consistent with the safety profile known for docetaxel, cisplatin and 5-FU. Mean clearance values for docetaxel and cisplatin showed no statistically significant difference across the "triple" and the "double" combination treatments, and the mean pharmacokinetic parameters of all agents were within the ranges for previously reported single agent treatment. CONCLUSION: No clinically relevant pharmacokinetic interactions between docetaxel, cisplatin and 5-FU used in combination were noticed in this study.

Retinoids induce fibroblast growth factor-2 production in endothelial cells via retinoic acid receptor alpha activation and stimulate angiogenesis in vitro and in vivo.

The effect of retinoic acid (RA) on endothelial cells is still controversial and was examined in the present study. In bovine aortic endothelial cells (BAECs), all-trans RA (ATRA) and 9-cis RA (9CRA), but not 13-cis RA (13CRA), induced fibroblast growth factor-2 (FGF-2) production and exhibited a biphasic dose-dependent effect to enhance BAEC proliferation and differentiation into tubular structures on reconstituted basement membrane proteins (Matrigel); both processes were inhibited by FGF-2-neutralizing antibody. The pan RA receptor (RAR)-selective ligand (E)-4-[2-(5,5,8,8,-tetramethyl-5,6,7,8-tetrahydro-2-naphtalenyl)-1-propenyl] benzoic acid and the RARalpha-selective ligand 4-[1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydro-2-naphtyl)-ethenyl] benzoic acid stimulated the production of FGF-2, whereas the addition of the RARalpha-antagonist RO 41-5253 inhibited this effect. In BAECs, the forced expression of RARalpha, but not RARbeta or RARgamma, enhanced FGF-2 production, whereas the RARalpha-dominant negative, Delta403, blocked this effect. Furthermore, RARalpha overexpression directly stimulated BAEC differentiation on Matrigel and potentiated the effects of ATRA in this assay. Finally, ATRA-treated BAECs coinjected with Matrigel subcutaneously in mice induced neovascularization within the Matrigel plug, and ATRA also enhanced angiogenesis in the chicken chorioallantoic membrane assay. In conclusion, RA can stimulate endothelial cell proliferation and differentiation in vitro via enhanced RARalpha-dependent FGF-2 production, and it can also induce angiogenesis in vivo. The full text of this article is available at http://www.circresaha.org.

Medullary thyroid carcinomas in transgenic mice expressing a Polyoma carboxyl-terminal truncated middle-T and wild type small-T antigens.

Medullary thyroid carcinoma (MTC) is a rare human tumor affecting the calcitonin-secreting c-cells of the thyroid. Here we report that two independent strains of transgenic mice expressing a Polyomavirus (Py) truncated middle-T antigen (deltaMT), consisting of the amino-terminal 304 amino acids, and the full length Py small-T antigen, developed multifocal bilateral MTCs with 100% penetrance. Occasionally one strain also developed mammary and bone tumors. Furthermore, offspring from both transgenic lines displayed pronounced waviness of the whiskers and fur, previously associated with defective epidermal growth factor receptor signaling. Transgene transcription, driven by the homologous early promoter/enhancer, and the corresponding translation products were detected in tumors and in many other organs which did not develop pathologies. The subcellular distribution of deltaMT and its interactions with the adapter proteins of the SHC family have also been analysed. Our study describes a novel murine model of MTC and provides evidence that the N-terminal 304 amino acid fragment of Py middle-T antigen, possibly in co-operation with small-T antigen, acts as a potent oncogene in c-cells of the thyroid.

The 5' sequence of human factor XII gene contains transcription regulatory elements typical of liver specific, estrogen-modulated genes.

The human Factor XII gene codes for a serine proteinase synthesized in liver that activates both the coagulation and the fibrinolytic cascades. The nucleotide sequence analysis of a HincII-HincII 3129 bp fragment was performed showing that the FXII promoter region contains neither CAAT and TATA regulatory elements, nor GC islands, but revealing the presence of two tandemly repeated sequences in opposite orientation, two LF-A1 elements typical of the liver specific genes and one estrogen responsive element, that substantiates the observation of Factor XII gene modulation by estrogens.

E1A stimulates FGF-2 release promoting differentiation of primary endothelial cells.

Basic Fibroblast Growth Factor (FGF-2) is a growth and survival factor and represents one of the most potent differentiation agents of vascular system. In the present study we describe that adenoviral oncoprotein E1A regulates FGF-2 production and determines the acquisition of a pro-angiogenic phenotype in primary bovine aortic endothelial cells (BAEC). Following their transfection, wild type E1A proteins 12S and 13S (wtE1A) stimulated BAEC to differentiate on reconstituted basement membrane matrix (Matrigel). This outcome was paralleled by invasion and migration enhancement in wtE1A-transfected cells. This stimulating effect was absent with the E1A mutant dl646N. Accordingly, zymography and RT - PCR analyses showed that matrix metalloproteinase-9 protein- and mRNA-levels increased following wtE1A transfection. Interestingly, wtE1A-transfected BAEC showed FGF-2 mRNA- and protein-levels higher than controls. Further, FGF-2 neutralization reduced the amount of MMP-9 released in the supernatant of E1A-transfected cells and strongly inhibited BAEC differentiation, thus suggesting that wtE1A activates BAEC by a mechanism, at least partially, dependent on a FGF-2 autocrine/paracrine loop.

In vitro and in vivo synergy of levofloxacin or amikacin both in combination with ceftazidime against clinical isolates of Pseudomonas aeruginosa.

The aim of the present study was to explore the antibacterial activity of the levofloxacin (LVX) and ceftazidime (CAZ) combination compared with the amikacin (AMK)/CAZ combination against Pseudomonas aeruginosa. Minimum inhibitory concentrations (MICs) were determined according to NCCLS. FIC indices (Fl) were calculated by the checkerboard technique. CAZ combined with LVX or AMK yielded Fls indicating synergism (Fl < or = 0.5) for 71/102 (69.6%) and 81/102 (79.4%) (p = 0.108), indifference (FI > 0.5-4) for 24/102 (23.5%) and 12/102 (11.7%) (p = 0.027), and antagonism (Fl > 4) for 7/102 (6.8%) and 9/102 (8.8%) (p = 0.602) strains, respectively. In vivo, CAZ/LVX was as bactericidal as CAZ/AMK combination. Our results support the potential role of LVX as an alternative to AMK in the combination therapy with CAZ in the treatment of P. aeruginosa severe infections. Anyway, further investigations and clinical trials are awaited until any definitive conclusions can be drawn.

Enzootic bovine leukosis: report of eradication and surveillance measures in Italy over an 8-year period (2005-2012).

Bovine leukaemia virus (BLV) is associated with enzootic bovine leukosis (EBL). BLV causes malignant lymphoma and lymphosarcoma; however, most BLV infections remain clinically silent in an aleukaemic state. EBL is a notifiable disease, and official control measures include screening or monitoring, precautions at borders, control of movement inside the country, and stamping out. The objective of this study was to evaluate EBL eradication and surveillance measures in Italy from 2005 to 2012. One-hundred twenty-three outbreaks were recorded (1 January 2006 to 31 December 2012) in the National Veterinary Information System (SIMAN) on 7 November 2013. Of these, 101 had occurred in southern Italy. An outbreak usually lasted for a few days, but sometimes lasted for weeks. Some areas were subjected to normal eradication measures, whereas others were subjected to additional eradication measures as a consequence of persisting EBL outbreaks. During the study period, we noted an overall annual decrease from 0.21% in 2005 to 0.08% in 2012 in the herd prevalence rate, from 0.06% in 2005 to 0.04% in 2012 in the herd incidence rate, and from 0.027% in 2005 to 0.015% in 2012 in the animal prevalence rate. Regions officially recognised as EBL-free areas were found to have their own surveillance plans. Differences in their surveillance plans include the type of sample (serum, milk, or both), age at which the animals must be tested (12 or 24 months), and test frequency of herds (annually or every 2, 3, 4, 5, or 6 years). The eradication programme for EBL is difficult to implement in some Italian areas because of several factors such as incomplete herd registry, geographical location and socio-economic conditions of the region.

Positive and sustained effects of highly active antiretroviral therapy on HIV-1-associated neurocognitive impairment.

OBJECTIVES: To determine whether highly active antiretroviral therapy (HAART) is effective in HIV-associated neurocognitive impairment. DESIGN: An open label, prospective, observational study. METHODS: Since April 1996, 116 patients with advanced HIV infection, reverse transcriptase inhibitor (nRTI) experienced but protease inhibitor (PI) naive, were screened for the presence of neurocognitive impairment. Ninety patients with confounding neurological illness, opportunistic infections or drug abuse were excluded. The remaining 26 patients underwent comprehensive neuropsychological testing, and laboratory measures before, after 6 and after 15 months of treatment with one PI plus two nRTI. RESULTS: The prevalence of neurocognitive impairment decreased from 80.8% (baseline) to 50.0% (P<0.05) (sixth month) and to 21.7% (P<0.001) (15th month). Among the functions explored, the impairment of concentration and speed of mental processing decreased from 65.4 to 21.7% (P<0.01) and of memory impairment from 50 to 8.7% (P<0.01). Comparing baseline with the sixth and 15th month raw scores, a statistically significant improvement was seen in measures exploring concentration and speed of mental processing (P<0.05), mental flexibility (P<0.05), memory (P<0.05), fine motor functions (P<0.05) and visuospatial and constructional abilities (P<0.01). After 6 months of HAART patients with a normal neuropsychological examination had lower mean plasma viraemia (2.95 versus 3.97 log copies/ml, P<0.05) and greater mean log plasma HIV RNA changes from baseline (-1.84 versus -0.83 log copies/ml, P<0.05) than neuropsychologically impaired subjects. CONCLUSION: HAART produces a positive and sustained effect on neurocognitive impairment in HIV-infected patients. A reduction of plasma viral load was associated with the regression of neuropsychological test abnormalities.

Fibroblast growth factor 10 induces proliferation and differentiation of human primary cultured keratinocytes.

Fibroblast growth factor 10 is a novel member of the fibroblast growth factor family, which is involved in morphogenesis and epithelial proliferation. It is highly homologous to the keratinocyte growth factor (or fibroblast growth factor 7), a key mediator of keratinocyte growth and differentiation. Both fibroblast growth factor 10 and keratinocyte growth factor bind with high affinity to the tyrosine kinase keratinocyte growth factor receptor. Here we analyzed the effect of fibroblast growth factor 10 on primary cultures of human keratinocytes, grown in chemically defined medium, and we compared the proliferative and differentiative cell responses to fibroblast growth factor 10 with those induced by keratinocyte growth factor and epidermal growth factor. Cell counting, 5-bromo-2'-deoxyuridine incorporation, and western blot analysis showed that fibroblast growth factor 10, similarly to keratinocyte growth factor, not only is a potent mitogen for human keratinocytes, but also promotes the expression of both early differentiation markers K1 and K10 and late differentiation marker filaggrin in response to the Ca2+ signal, and seems to sustain the proliferative activity in suprabasal stratified cells. Immunoprecipitation/western blot analysis revealed that fibroblast growth factor 10, similarly to keratinocyte growth factor, is able to induce tyrosine phosphorylation of keratinocyte growth factor receptor and of cellular substrates such as PLCgamma.

Molecular basis of estrogen regulation of Hageman factor XII gene expression.

Estrogen therapy has been reported to cause multiple alterations in hemostasis and to increase blood levels of several procoagulants, including Hageman factor [factor XII (FXII)]. Liver FXII gene expression has been investigated in ovariectomized rats, treated or not with 17 beta-estradiol. A 6-fold stimulation of FXII gene transcription was observed in treated compared to untreated animals, indicating that 17 beta-estradiol is able to induce FXII gene expression in vivo. We have recently shown that human FXII promoter contains an imperfect palindrome, 5'-GGGCAnnnTGACC-3', at position -43/-31 resembling the consensus estrogen-responsive element (ERE). Portions of different length of the FXII promoter were fused to the chloramphenicol acetyltransferase (CAT) coding sequence and transiently cotransfected with human estrogen receptor (ER) into NIH3T3 and HepG2 cells in the presence or absence of 17 beta-estradiol. A 230-base pair fragment of FXII promoter, spanning nucleotides - 181/49, conferred a strong estrogen responsiveness to the CAT reporter gene, suggesting that a functional ERE resides in this region. Cognate receptors, such as those for thyroid hormone or retinoic acid, did not stimulate CAT activity. Gel mobility assays demonstrated a specific interaction between ER and the 230-bp FXII promoter fragment containing the putative ERE palindrome. Similar results were obtained when an oligonucleotide spanning the consensus ERE was used; the complex between ER and FXII promoter sequences was supershifted after the addition of an anti-ER monoclonal antibody. Insertion of FXII-ERE into the heterologous thymidine kinase promoter conferred a strong estrogen responsiveness that was abolished by mutations of the 5'-half of the palindrome. These results represent the first demonstration at the molecular level of the regulation of a blood coagulation factor gene by 17 beta-estradiol as well as the first identification of a functional ERE within this class of genes.

Retinoic acid modulates the asialoglycoprotein receptor expression in cultured fetal rat hepatocytes.

The influence of retinoic acid on the expression of a typical marker of hepatocyte differentiation, i.e. the asialoglycoprotein receptor, has been studied. Cultured hepatocytes, isolated from adult rats, a model of quiescent, mature cells and from 20-day-old fetuses, a model of proliferating and less differentiated cells, were used. The asialoglycoprotein receptor expression appears to be affected by retinoic acid during prenatal life; both mRNA level and protein amount increased in fetal hepatocytes, but no modification has been found in adult cells, suggesting a regulative effect of retinoic acid during prenatal life, acting at transcriptional and/or translational level. Surprisingly, the receptor binding activity of adult hepatocytes is decreased after retinoic acid treatment, indicating a possible further modulation by this molecule on receptor activity at the post-translational level.

Dosing strategies for anticancer drugs: the good, the bad and body-surface area.

Most anticancer drugs are characterised by a narrow therapeutic window; hence, a small change in dose can lead to poor antitumour effects or an unacceptable degree of toxicity. The rationale for using body surface area (BSA) to dose antineoplastic agents is to normalise the effects of drugs, and accordingly, it has been routinely employed as the only independent variable. In the last 10 years, however, several studies have shown a poor relationship of BSA for predicting drug exposure, and an irrelevant correlation between this variable and pharmacokinetic (PK) parameters. In this paper, the results of this relationship for various commonly used antineoplastic agents are reviewed, and the influence of BSA to decrease the total variability in clearance among patients is underlined. As reported, BSA failed to individualise the effects of the majority of the agents explored. The criteria that can predict a clinically meaningful relationship between BSA and drug clearance are discussed, and some alternative strategies to dose agents when BSA has proven to be useless are proposed.

Overproduction and purification of the Aeromonas hydrophila CphA metallo-beta-lactamase expressed in Escherichia coli.

The Aeromonas hydrophila CphA metallo-beta-lactamase was overexpressed in a soluble secreted form in Escherichia coli using a T7 RNA polymerase-based expression system, and a simple protocol based on a single cation-exchange chromatographic step was developed, which is suitable for rapid purification of the overexpressed enzyme from E. coli lysates. A yield of up to 30 micrograms of purified enzyme per milliliter of culture was obtained. The purified enzyme preparation showed properties identical to those previously reported in the literature.