A novel p27 gene mutation in a case of unclassified myeloproliferative disorder

P27 encodes a member of Cip/Kip family of cyclin dependent kinase inhibitors, the inactivation of which has been implicated in the pathogenesis of various hematological neoplasias. We report on a novel point mutation of this gene identified in a case of unclassified myeloproliferative syndrome consisting of a T --> C transversion at 821bp of p27 exon 1, resulting in a Ile --> Thr substitution at codon 119. The analysis of larger number of cases as well as the effect of this mutation on protein's function will help to clarify its significance in the pathogenesis of myeloproliferative syndromes.     

Relation between bone marrow angiogenesis and serum levels of angiogenin in patients with myelodysplastic syndromes

Angiogenesis is implicated in the progression of myelodysplastic syndromes (MDS). Bone marrow microvascular density (MVD), serum angiogenin (ANG) and interleukin 6 (IL-6) were measured in 67 patients with untreated MDS. MVD, ANG and IL-6 were significantly higher in the patient group as a whole when compared to controls (P < 0.01). MVD and ANG were significantly higher in subtypes with a high-risk for leukemic transformation (RAEB, RAEB-t and CMML) than in low-risk subtypes (RA and RARS) (P < 0.01). In the MDS group, a positive correlation was found between ANG and IL-6 (P < 0.001) and also between MVD and IL-6 (P < 0.05). Using multivariate analysis, only IL-6 displayed independent prognostic value and was inversely related to MDS survival.     

Serum evaluation of angiogenic cytokine basic fibroblast growth factor, hepatocyte growth factor and TNF-alpha in patients with myelodysplastic syndromes: correlation with bone marrow microvascular density

Recent studies have documented that angiogenesis plays a significant role in haematological malignancies, including mylodysplastic syndromes (MDS). Basic fibroblast growth factor (b-FGF), Hepatocyte growth factor (HGF) and Tumor necrosis factor-alpha (TNF-alpha) are multifunctional cytokines that potently stimulate angiogenesis. The aim of the present study was to evaluate the microvascular density (MVD) and the serum levels of these angiogenic factors in patients with myelodysplastic syndromes (MDS). In 61 patients with MDS, MVD was measured in bone marrow biopsies and b-FGF, HGF and TNF-alpha were determined in the serum of the same patients by enzyme-linked immunosorbent assay (ELISA). Serum levels of b-FGF, HGF and TNF-alpha as well as MVD in the bone marrow were increased in MDS patients compared to healthy controls (p<0.0001). Levels of b-FGF, HGF and TNF-alpha were also significantly higher in high-risk for leukemic transformation MDS than in low-risk (p<0.0001). Significant differences were also found regarding MVD in high and low risk patients (p<0.001). Both b-FGF and HGF levels were significant predictors of survival (p<0.0005, log-rank test). The present study showed that serum levels of b-FGF, HGF and TNF-alpha are significantly increased and dependent on the severity of MDS suggesting that the determination of these parameters may offer considerable information regarding disease progression and prognosis.     

Hidden chromosome 8 abnormalities detected by FISH in adult primary myelodysplastic syndromes

Acquired clonal chromosomal abnormalities are found in about 30-50% of primary myelodysplastic syndromes (MDS). These abnormalities are predominantly characterized by total/partial chromosomal losses or gains and rarely by balanced structural aberrations. Trisomy 8 represents the most common chromosomal gain. In the present study, the numerical aberration of chromosome 8 was evaluated by the fluorescence in situ hybridization (FISH) technique in MDS, and the results compared with those of conventional cytogenetics. Thirty adult patients with primary MDS, 17 with a normal karyotype and 13 with several chromosomal abnormalities except chromosome 8, were included in this study. On comparing the results of FISH and conventional cytogenetics, a superiority of FISH over the karyotype was detected in 3 cases. In one of them, further cytogenetic analysis confirmed the FISH results. Nevertheless, the FISH technique has limitations, detecting only abnormalities specific for the target FISH probe used In clinical practice, conventional cytogenetics continues to be the basic technique for MDS patient evaluation. However, a large number of metaphases, even those of poor quality, must be analyzed in each case. The FISH technique could be considered to be complementary to achieve a more accurate analysis.     

Benefit of appropriate empirical antibiotic treatment: thirty-day mortality and duration of hospital stay

Purpose

We evaluated the effect of inappropriate antibiotic treatment on mortality and duration of hospital stay in medical inpatients with bacterial infections.

Subjects and methods

Two cohorts of febrile adult patients (excluding patients with acquired immune deficiency syndrome and organ transplant recipients), hospitalized in three medical centers in Israel, Italy, and Germany, were included. Patients’ data were collected prospectively. Initial empirical treatment was defined as appropriate if an antibiotic prescribed within 24 hours of the first encounter with the patient matched the in vitro susceptibility of a pathogen deemed to be the likely cause of infection. The results of cultures and serologic or direct tests, and data on outcomes were collected 30 days after initiation of empirical treatment.

Results

A total of 920 patients (26% of 3529 included patients) had microbiologically documented infections, and mortality data were available for 895 patients (97%). Inappropriate initial antibiotic treatment was prescribed in 36% of patients (N = 319). All-cause 30-day mortality rates were 20.1% (N = 64) and 11.8% (N = 68) in patients who received inappropriate and appropriate treatment, respectively (odds ratio = 1.88, 95% confidence interval [CI], 1.29-2.72, P = .001). When adjustment was made for medical center and other variables, the association between inappropriate with mortality was significant (odds ratio = 1.58, 95% CI, 0.99-2.54, P = .058). In all 3 medical centers, the mean duration of hospital stay was at least 2 days longer for patients who were prescribed inappropriate antibiotic treatment (overall P = .002). This association was consistent after adjusting for other variables (P = .006).

Conclusion

Appropriate empirical antibiotic treatment is associated with a better survival and shortened duration of hospital stay in medical patients with bacterial infections.     

Beta-lipoprotein- and LDL-associated serum gamma-glutamyltransferase in patients with coronary atherosclerosis

Elevation of serum gamma-glutamyltransferase (GGT) activity is a risk factor for myocardial infarction and stroke. GGT activity can catalyze the oxidation of low-density lipoprotein (LDL), a process involved in the pathogenesis of atherosclerosis. Serum GGT is partially adsorbed onto circulating LDL, and catalytically active GGT has been found within atherosclerotic plaques, colocalizing with oxidized LDL and foam cells. We investigated the the nature of the LDL-associated GGT, the degree of correlation between total serum GGT levels and beta-lipoprotein (beta-LP)-associated GGT, and whether this association is altered in subjects with coronary artery disease (CAD). LDL-bound GGT showed an entire, amphiphilic heavy chain, but the association was easily lost during LDL purification by affinity chromatography. When the activity of GGT associated with polycation-precipitated beta-lipoproteins was assayed, an identical immunoreactive GGT was found in Western blot, and a statistically significant linear correlation was found between total serum GGT levels and the corresponding beta-LP-bound activities (p<0.0001) in controls and patients with CAD. Nevertheless, subjects with CAD presented a lower ratio of beta-LP-bound GGT to total serum GGT respect to controls (p<0.05) and healthy subjects with elevated serum GGT (p<0.01). In addition, a relative decrease of total serum GGT was observed in CAD subjects of older age as compared to younger ones (p<0.005).     

Evolution of HIV resistance mutations in patients maintained on a stable treatment regimen after virologic failure

OBJECTIVE: We compared the rate of emergence of thymidine analogue mutations (TAMs) and major protease inhibitor mutations in adherent patients who remained on stable treatment with a thymidine analogue and/or protease inhibitor after the onset of virologic failure. DESIGN: Follow-up genotypic resistance testing was done using archived plasma obtained from patients having 0 or 1 TAM and/or 0 or 1 major protease inhibitor resistance mutation at the onset of virologic failure. RESULTS: The median duration of observed failure was 691 days. There were 41 thymidine analogue regimens and 34 protease inhibitor regimens; concomitant ritonavir was used 4 times. New major protease inhibitor mutations emerged more rapidly than did new TAMs (P = 0.0019); new TAMs emerged more rapidly in thymidine analogue regimens that did not include lamivudine (P = 0.0073). The emergence of TAMs and major protease inhibitor mutations did not differ if lamivudine was not part of the thymidine analogue regimen. The evolution of CD4 cell counts and plasma viral loads (pVLs) during virologic failure was similar regardless of whether or not a new TAM or major protease inhibitor mutations emerged or, for thymidine analogue-containing regimens, whether lamivudine was or was not used. CONCLUSIONS: Major protease inhibitor mutations arose more frequently and rapidly than did TAMs in patients with sustained virologic failure who received lamivudine.     

Novel antimicrobial lipopeptides with long in vivo half-lives

The pharmacokinetic (PK) properties of novel lipopeptides (semi-synthetic amphomycin analogues) with potent activity against Gram-positive organisms were evaluated in mice and rats following single intravenous (i.v.) and oral administration. Following oral administration at 50 mg/kg, plasma concentrations of amphomycin analogues were <0.3–0.9 μg/mL, suggesting that oral availability was low. Following i.v. administration (5–10 mg/kg), the majority of lipopeptides demonstrated a long half-life (5.2–8.0 h in mice and 4.6–7.1 h in rats), low clearance (0.005–0.016 mL/min in mice and 0.050–0.084 mL/min in rats) and a volume of distribution indicative of extracellular penetration (0.118–0.339 L/kg in mice and 0.121–0.133 L/kg in rats). The area under the plasma concentration–time curve extrapolated to infinity (AUC_0?∞) for a 10 mg/kg i.v. dose was determined to be 601.7–791.7 μg h/mL in mice and 511.1–850.2 μg h/mL in rats. The long half-life and low clearance observed with these novel lipopeptides indicate that drug serum concentrations will remain above the target minimal inhibitory concentration (MIC) levels for significant periods of time. When combined with the potent efficacy of these agents against Gram-positive organisms, the results of the present study support further development of these lipopeptide analogues towards clinical evaluation.     

CT dataset anisotropy management for oral implantology planning software

Purpose

Measurements accomplished on most oral implantology software are often affected by some systematic effects, of which those related to the CT dataset anisotropy are the most relevant. In fact, most of these commercial systems do not manage possible anisotropy in input datasets, leaving the responsibility to users and radiologists. Therefore, in order to achieve a better knowledge of the patient’s anatomy before inserting the implants, and thus reducing the risk of damaging the surrounding structures, the implementation of a complete and precise anisotropy management system is required.

Methods

We present an anisotropy management algorithm for pre-operative planning software that is able to handle any anisotropic CT dataset, and, as a result, provides a very precise isotropic equivalent. The developed algorithm exploits two interpolation passes to correct anisotropy and is characterised by linear complexity, needing just a few seconds to accomplish the tasks. The first pass concerns the integer-filling of possible intra-slice void spaces of the original slices, having the responsibility of a correct spreading of the radiographic details along the volume height axis. The second pass, instead, reformats its input dataset under isotropic conditions exploiting a contribution-based interpolation sub-algorithm.

Results

The algorithm has been evaluated by comparing the anisotropy implied systematic effects for both anisotropic and interpolation-reconstructed radiographic volumes of five different scans. The proposed system demonstrated to be able to successfully handle any dataset interslice—pixel-size ratio. Moreover, the precision achieved proved to be even better than that of another precise algorithm that we previously developed and published, validating the proposed approach as a consequence.

Conclusions

The proposed algorithm makes it possible to handle and correct anisotropy in input CT datasets, helping to avoid anisotropy implied systematic effects on related measurements, and consequently supporting pre-operative planning software by providing a precise and isotropic equivalent volume on which to work.