A healing ionomer crosslinked by a bis-bidentate halogen bond linker: a route to hard and healable coatings

A bis-bidentate halogen bond linker was introduced into a fully organic, phosphate based ionomer, yielding a crosslinked network with healing abilities and improved mechanical properties.

Incidentally detected splenic lesions in ultrasound: does contrast-enhanced ultrasonography improve the differentiation of benign hemangioma/hamartoma from malignant lesions?

PURPOSE

The aim of the study was to identify and validate enhancing features for differentiating benign vascular neoplasms of the hemangioma/hamartoma type from malignant splenic lesions on contrast-enhanced ultrasonography (CEUS).

MATERIALS AND METHODS

136 splenic lesions (58 benign vascular neoplasms, 78 malignant) in 136 patients underwent baseline US and pulse-inversion CEUS after sulfur hexafluoride-filled microbubble injection. Two on-site readers assessed lesion enhancement features during arterial and parenchymal phase in consensus. Best predicting CEUS features for lesion diagnosis were identified through univariate and multivariate analyses. Two blinded off-site readers independently issued a confidence rating for lesion diagnosis in baseline US and CEUS using extracted diagnostic CEUS features. Diagnostic performance, receiver operating curves (Az-value), and interreader agreement were calculated. The reference standards were histopathology or CT and/or MR imaging with clinical follow-up. 

RESULTS

Multivariate analysis outlined arterial hyperenhancement or isoenhancement to be an independent CEUS predictor of benign vascular neoplasms (odds ratio, 3.558; p < 0.0017). Within the subgroup of isoechoic or hypoechoic lesions, arterial hyperenhancement was virtually diagnostic for benign vascular neoplasm (odds ratio, 21.333; p < 0.001). The diagnostic accuracy and confidence (Az-value) of the two readers was 63.2 % and 70.6 % (0.785 and 0.818) for baseline US, which improved significantly to 87.5 % and 88.2 % (0.915 and 0.908) for CEUS (p < 0.001). Interreader agreement also increased with CEUS (қ = 0.88) compared to baseline US (қ = 0.52).

CONCLUSION

Sulfur hexafluoride-enhanced CEUS improves differentiation between benign vascular and malignant splenic tumors and may be especially useful in clinical scenarios in which the incidental hypoechoic splenic lesion is unclear on conventional US.

Reduced-toxicity conditioning with treosulfan, fludarabine and ATG as preparative regimen for allogeneic stem cell transplantation (alloSCT) in elderly patients with secondary acute myeloid leukemia (sAML) or myelodysplastic syndrome (MDS)

We investigated a dose-reduced conditioning regimen consisting of treosulfan and fludarabine followed by allogeneic stem cell transplantation (SCT) in 26 patients with secondary AML or MDS. Twenty patients were transplanted from matched or mismatched unrelated donors and six from HLA-identical sibling donors. The median age of the patients was 60 years (range, 44-70). None of the patients was eligible for a standard myeloablative preparative regimen. No graft-failure was observed, and leukocyte and platelet engraftment were observed after a median of 16 and 17 days, respectively. Acute graft-versus-host disease (GvHD) grade II-IV was seen in 23% and severe grade III GvHD in 12% of the patients. No patients experienced grade IV acute GvHD. Chronic GvHD was noted in 36% of the patients, which was extensive disease in 18%. The 2-year cumulative incidence of relapse was 21%. The relapse rate was higher in patients beyond CR1 or with intermediate two or high risk MDS (P = 0.02). The treatment-related mortality at day 100 was 28%. The 2-year estimated overall and disease-free survival was 36-34%, respectively. No difference in survival was seen between unrelated and related SCT.

Comparable results in patients with acute lymphoblastic leukemia after related and unrelated stem cell transplantation

We report the results of 84 patients with ALL after related (n = 46) or unrelated (n = 38) allogeneic SCT. Mean recipient age was 23 years (range: 1-60) and median follow-up was 18 months (range: 1-133). Forty-three patients were transplanted in CR1; 25 in CR2 or CR3; four were primary refractory; four in PR; eight in relapse. The conditioning regimen consisted of TBI/VP16/CY (n = 76), TBI/VP16 (n = 2), TBI/CY (n = 2), Bu/VP16/CY (n = 4). The OS at 3 years was 45% (44% unrelated, 46% related). Univariate analysis showed a significantly better OS for patients <18 years (P=0.03), mismatched sex-combination (P = 0.03), both with a stronger effect on increasing OS after unrelated SCT. Factors decreasing TRM were patient age <18 years (P = 0.004), patient CMV-seronegativity (P = 0.014), female recipient (P = 0.04). There was no significant difference in TRM and the relapse rate was similar in both donor type groups. Multivariate analysis showed that factors for increased OS which remained significant were mismatched sex-combination (RR: 0.70,95% CI: 0.51-0.93, P = 0.015), patient age < 18 years (RR: 0.66, 95% CI: 0.47-0.93, P = 0.016). A decreased TRM was found for female patients (RR: 0.56, 95% CI: 0.33-0.98, P=0.042), negative CMV status of the patient (RR: 0.57, 95% CI: 0.36-0.90, P = 0.015). Unrelated stem cell transplantation for high-risk ALL patients with no HLA-compatible family donor is justifiable.

[Unrelated donor stem cell transplantation in children: low toxicity using a GvHD-prophylaxis regimen with CSA, MTX, metronidazole,iv-immunoglobulin and ATG]

BACKGROUND

Unrelated donor (UD) hematopoietic stem cell transplantation (HSCT) is accepted as a therapy for leukaemic diseases and varying inborn diseases if a suitable related donor cannot be found. The goal of immunosuppressive therapy with UD-HSCT is an effective prevention of graft-versus-host-disease (GvHD) on one hand. On the other hand an optimal balance with immunocompetence of the transplanted bone marrow is desirable in order to prevent graft failure, infection and, in the case of leukaemic diseases, potentially control the underlying disease.

PATIENTS AND METHODS

Between 1992 and 2000 49 patients aged 11 months to 16.7 years received an UD-HSCT in Hamburg. Underlying diseases were leukaemia or MDS in 35, of these ALL in 21, hemophagocytic lymphohistiocytosis (HLH) in 9, immunodeficiency or inborn error of metabolism in 5 patients. GvHD-prophylaxis consisted of a combination of Cyclosporin A (CSA), methotrexate (MTX), metronidazole, IgM-enriched iv-immunoglobulin (ivIg) (Pentaglobin(R)) or ivIgG and anti-thymocyte-globulin (ATG). Within the same time span 10 patients with ALL received a matched related donor HSCT (MRD-HSCT). GvHD-prophylaxis in these patients was done without ATG in 8 of 10 cases. UD-HSCT were analyzed for survival, relapse and toxicity. Probability of survival of the patients with ALL after UD-HSCT was compared with results of MRD-HSCT in children with ALL.

RESULTS

The Kaplan-Meier estimates of three year overall-survival (OS) were 74 % for all patients. Probability of disease-free survival (DFS) at three years was 62 % for leukaemia/MDS-patients and 100 % for the HLH-patients. Acute GvHD (aGvHD) grades II or III occurred in 51 % of patients. Chronic GvHD (cGvHD) occurred in 22 % of patients. There were 5 cases of treatment-related mortality (TRM). Probability of DFS for patients with ALL at three years was 65 % after UD-HSCT and 30 % in the patients after MRD-HSCT.

CONCLUSIONS

UD-HSCT in children is an effective and safe therapy. A GvHD-prophylaxis regimen combining the standard immunosuppressive agents CSA and MTX with ivIg, metronidazole and serotherapy using ATG may result in a low incidence of severe GvHD-complications and low TRM rate without increase in relapse rates.

Optimizing fast spin echo acquisitions for hepatic imaging in normal subjects

The purpose of this study was to determine which implementations of a T2-weighted fast spin-echo sequence of the liver resulted in observer preference in normal subjects. Five volunteers were scanned with a series of fast spin-echo sequences modified to allow for flow compensation, respiratory triggering (RT), ECG triggering, randomized phase encoding (RPE), breath-holding, and echo train length (ETL). Images were compared with conventional 2500/40/80 msec spin-echo images using flow compensation and spatial presaturation by two observers blinded to the specific sequence parameters. All FSE sequences were completed in less than the 12 minutes necessary to perform a conventional spin-echo sequence. The most preferred fast spin-echo sequence employed flow compensation, RT, and used an 8 ETL. Analysis of image preference, signal to noise, and contrast to noise showed that RT was the single most important variable in determining each image response (P < .01, P < .02, P < .01, respectively). There was some evidence that images obtained with an 8 ETL were preferred over those using a 16 ETL (P = .07). No other variables approached statistical significance although one reader preferred images with flow compensation in the frequency direction to those either not flow compensated or flow compensated in the slice direction. Respiratory triggered fast spin-echo images combined with flow compensation in the frequency direction and using ETL = 8 can provide image quality equal to conventional spin-echo sequences with significant time savings.

A ventilator for magnetic resonance imaging

Breathing motion severely degrades the quality of magnetic resonance images (MRI) of the thorax and upper abdomen and interferes with the acquisition of quantitative data. To minimize these motion effects, we built an MRI compatible ventilator for use in animal studies. Solid state circuitry is used for controlling ventilation parameters. The ventilator can be triggered internally at frequencies of 0.1 to 30 Hz or it can be triggered externally such as by the MRI pulse sequence. When triggered by the scanner, ventilation is synchronized to occur between image data acquisitions. Thus, image data are obtained when there is no breathing motion and at a minimum lung volume when hydrogen density is maximum. Since the ventilator can be adjusted to operate at virtually any frequency from conventional to high frequency, ventilation can be synchronized to all commonly used repetition times (100 ms to 2000 ms or more; 600 to 30 breaths/min). Scan synchronous ventilation eliminates breathing motion artifacts from most imaging sequences (single and multiple spin echo and inversion recovery). Best image quality is obtained when scan synchronous ventilation is combined with cardiac gating. These methods are also useful for quantitative research studies of thoracic and abdominal organs.