Virtual dissection and automated polyp detection of the colon based on spiral CT — Techniques and preliminary experience on a cadaveric phantom

Summary   Background: CT colonography was found to be sensitive and specific for detection of colonic polyps and colorectal cancer (CRC). Depending on the software used, CT colonography requires a certain amount of operator interaction, which limits it’s widespread usage. The goal of this papers is to present two novel automated techniques for displaying CT colonography: virtual dissection and automated colonic polyp detection. Methods: Virtual dissection refers to a technique where the entire colon is virtually stretched and flattened thus simulating the view on the pathologist’s table. Colonic folds show a ‘global outward bulging of the contour’, whereas colonic polyps exhibit the inverse (‘local inward bulging’). This feature is used to map areas of ‘local inward bulging’ with colours on 3D reconstructions. A cadaveric phantom with 13 artificially inserted polyps was used for validation of both techniques. Results: On virtual dissection all 13 inserted polyps could be identified. They appeared either as bumps or as local broadening of colonic folds. In addition, the automated colonic polyp detection algorithm was able to tag all polyps. Only 10 min of operator interaction were necessary for both techniques. Conclusions: Virtual dissection overcomes the shortcomings of CT colonography, and automated colonic polyp detection establishes a roadmap of the polyps.      

A new HPLC method to determine Donepezil hydrochloride in tablets.

A HPLC stability-indicating assay for Donepezil hydrochloride in tablets was developed and validated. Donepezil hydrochloride is a reversible inhibitor of acetylcholinesterase, indicated for the treatment of mild to moderate dementia of the Alzheimer's type. The HPLC method was performed with a reversed phase C18 column, detection at 268 nm and a mixture of methanol, phosphate buffer 0.02 M and triethylamine (50:50:0.5) as mobile phase. Typical retention time for Donepezil was 9 min. The method was statistically validated for linearity, accuracy, precision and selectivity following ICH recommendations. Due to its simplicity and accuracy, the method can be used for routine quality control analysis.     

The Role of Cats and Dogs in the Epidemiological Cycle of Microsporum canis*/Die Rolle von Katzen und Hunden im epidemiologischen Zyklus des Microsporum canis

Summary: In order to study the presence of dermatophytes in healthy domestic animals, 104 cats and 126 dogs were studied in São Paulo (Brazil), by using the technique of Mariat & Tapia. Microsporum canis was verified in 88.46% of cats and in 7.93% of dogs. In a lower percentage, M. gypseum, Trichophyton mentagrophytes and T. ajelloi were also isolated. In view of these data, more attention should be given to the cats due to their importance in the transmission and persistence of M. canis. Zusammenfassung: Zur Untersuchung auf Anwesenheit auf Dermatophyten in gesunden Haustieren wurden 104 Katzen und 126 Hunde in São Paulo (Brasilien) mit der Technik von Mariat & Tapia untersucht Microsporum canis konnte bei 88,46% der Katzen und bei 7,93% der Hunde isoliert werden. Mit einem niedrigeren Prozentsatz wurden auch M. gypseum, Trichophyton mentagrophytes und T. ajelloi gefunden. Die Ergebnisse zeigen die Bedeutung gesunder Katzen für die übertragung und den Weiterbestand von Microsporum canis-Infektionen.     

Growth factors and stromal support generate very efficient retroviral transduction of peripheral blood CD34+ cells from Gaucher patients

We have achieved high-efficiency gene transfer into nonmobilized peripheral blood (PB) CD34+ cells from patients with Gaucher's disease using a clinically acceptable retroviral supernatant transduction protocol. In our studies, bone marrow (BM) and PB CD34+ cells were transduced using a high titer (10(8) particles/mL) retroviral supernatant once a day for 4 consecutive days in the presence of interleukin-3 (IL-3), IL-6, and stem cell factor (SCF), with or without an irradiated allogeneic BM stromal layer. The growth factors alone resulted in 29% +/- 10% gene transfer of PB CD34+ clonogenic cells in contrast with 71% +/- 17% gene transfer efficiency using stroma with the growth factors; a 2.5-fold increase. The increase in gene transfer efficiency was less prominent when BM CD34+ cells were used (40% +/- 16% without and 57% +/- 8% with stroma, a 1.5-fold increase). The overall transduction efficiency of both PB and BM CD34+ cells was lower when the cells were transduced over a stromal cell layer without added growth factors. The combination of IL-3, IL-6, and SCF with stroma transduced 75% of primitive long-term culture initiating cells (PB LTC- ICs) in comparison with 34% of LTC-ICs when IL-3, IL-6, and SCF were used without stromal support. Using this clinically acceptable supernatant/cytokines/stroma transduction protocol, correction of the glucocerebrosidase (GC) deficiency in the progeny cells of PBLTC-ICs from Gaucher's-disease patients has been accomplished. Efficient transduction of the PB CD34+ cells using this transduction protocol may allow repeated delivery of "GC-corrected" hematopoietic stem and progenitor cells to Gaucher's-disease patients.     

Direct demonstration that autologous bone marrow transplantation for solid tumors can return a multiplicity of tumorigenic cells

Patients with solid tumors are increasingly being treated by autologous bone marrow transplantation (BMT). Although response rates appear to be increased, disease recurrence is the commonest cause of treatment failure. Whether relapse is entirely due to residual disease in the patient or arises also from infiltrating malignant cells contained in the autologous marrow transplant has not been resolved. If the latter explanation is correct, then purging would be required as part of the transplantation procedure. We used retrovirally mediated transfer of the neomycin-resistance gene to mark BM harvested from eight patients with neuroblastoma in clinical remission. The marked marrow cells were subsequently reinfused as part of an autologous BMT. At relapse, we sought the marker gene in malignant cell populations. Three patients have relapsed, and in each the marker gene was detected by phenotypic and genetic analyses of resurgent malignant cells at medullary and extramedullary sites. Analysis of neuroblast DNA for discrete marker gene integration sites suggested that at least 200 malignant cells, each capable of tumor formation, were introduced with the autologous marrow transplant and contributed to relapse. Thus, autologous BMTs administered to patients with this solid tumor may contain a multiplicity of malignant cells that subsequently contribute to relapse. The marker-gene technique we describe should permit evaluation of the mechanisms of relapse and the efficacy of purging in patients receiving autologous marrow transplantation for other solid tumors that infiltrate the marrow.     

Quantitative fiber tracking in the corpus callosum and internal capsule reveals microstructural abnormalities in preterm infants at term-equivalent age

BACKGROUND AND PURPOSE:Signal-intensity abnormalities in the PLIC and thinning of the CC are often seen in preterm infants and associated with poor outcome. DTI is able to detect subtle abnormalities. We used FT to select bundles of interest (CC and PLIC) to acquire additional information on the WMI.MATERIALS AND METHODS:One hundred twenty preterm infants born at <31 weeks'' gestation with 3T DTI at TEA entered this prospective study. Quantitative information (ie, volume, length, anisotropy, and MD) was obtained from fiber bundles passing through the PLIC and CC. A general linear model was used to assess the effects of factor (sex) and variables (GA, BW, HC, PMA, and WMI) on FT-segmented parameters.RESULTS:Seventy-two CC and 85 PLIC fiber bundles were assessed. For the CC, increasing WMI and decreasing FA (P = .038), bundle volume (P < .001), and length (P = .001) were observed, whereas MD increased (P = .001). For PLIC, MD increased with increasing WMI (P = .002). Higher anisotropy and larger bundle length were observed in the left PLIC compared with the right (P = .003, P = .018).CONCLUSIONS:We have shown that in the CC bundle, anisotropy was decreased and diffusivity was increased in infants with high WMI scores. A relation of PLIC with WMI was also shown but was less pronounced. Brain maturation is affected more if birth was more premature.

Premature birth of <30 weeks'' gestation is associated with a high risk of neurodevelopmental impairments, including cognitive and motor disabilities.^1–3 The underlying neuropathology for cognitive disabilities is largely unknown, though it has been suggested that disturbances in the WM maturation play a role.^4,5 In teenagers, the effects of preterm birth are associated with thinning of the CC, widening of the ventricles, reduced volumes of the WM, and microstructural changes in the PLIC and the CC.^6–9MR imaging is commonly performed in preterm infants around TEA to detect brain injury. Different scoring systems have been developed to quantify MR imaging findings.^2,10 Although these scoring systems were related to outcome, they did not provide information about the pathology on a microstructural level. WM maturation may best be followed with DTI because this technique uses both information on the diffusion properties of water molecules that are restricted in tissue and information on the direction of diffusion (anisotropy). DTI has been shown to be sensitive to microstructural WM changes, like myelination.^11,12 Most information concerning DTI changes in relation to brain maturation is available from studies assessing selected ROIs in the WM.¹¹ It has been shown that the anisotropy in preterm infants is decreased at TEA in certain brain regions (among these, the CC and the frontal WM) compared with term-born controls.¹³Instead of measuring local effects in selected ROIs, FT can be applied to measure changes in bundles of WM. FT is a 3D visualization technique that reconstructs the underlying linear structure defined by the diffusion tensor.¹⁴ Quantification of WM tracts in infants has been performed previously^15–23 and is based on calculating an average of a certain DTI parameter over the complete bundle. Axial and radial diffusivity over specific tracts have been shown to be differentially affected by bundle maturation with age,^20,21 and DTI parameters quantifying the corticospinal tract are affected in preterm infants with WMI.²² Only 1 study recently investigated the genu and splenium of the CC in premature infants at TEA by using FT.²³ The CC is of interest because reduced callosal volumes have been shown to correlate with motor function and cognitive impairment.^24,25The aim of our study was to investigate whether diffusion tensor parameters, abstracted by using FT to select complete CC and PLIC bundles, display WM abnormalities in the premature infant at TEA. The WMI score² (as measured with conventional MR imaging) was used as a reference index.We hypothesized that WMI would be better detected with DTI and that it would give more information on the microstructure. We investigated, furthermore, how the DTI parameters were affected by GA at birth, BW, HC, sex, and the PMA, defined here as the age at the time of scanning.     

Plasma P-selectin is increased in thrombotic consumptive platelet disorders

P-selectin is a 140-kD protein found in the alpha-granules of platelets and the Weibel-Palade bodies of endothelial cells that on cell activation is expressed on the cell surface and also secreted into the plasma. The secreted form of P-selectin, like plasma P-selectin, differed from platelet membrane P-selectin in that its molecular mass was approximately 3 kD lower under reducing conditions. Both the secreted and plasma forms of P-selectin contained cytoplasmic sequence as determined by Western blot analysis with an affinity-purified rabbit anti-P-selectin cytoplasmic peptide antibody. We have measured plasma P- selectin and beta-thromboglobulin (beta TG) concurrently in (1) patients with consumptive thrombotic disorders, including disseminated intravascular coagulation (DIC), heparin-induced thrombocytopenia (HIT), and thrombotic thrombocytopenic purpura (TTP)/haemolytic uremic syndrome (HUS); (2) patients with idiopathic thrombocytopenic purpura (ITP); and (3) healthy controls. Patients with DIC, HIT, and TTP/HUS, but not ITP, had significantly elevated plasma P-selectin and beta TG levels when compared with their age-matched healthy controls. The increased plasma P-selectin and beta TG in patients with thrombotic disorders were likely to be the result of in vivo platelet and endothelial cell damage or activation. We also found that avoidance of veno-occlusion and other tedious measures customarily taken during blood collection and sample preparation to prevent in vitro platelet activation did not affect plasma P-selectin assay results. In addition, plasma P-selectin levels were not influenced by the presence of renal failure or heparin administration. These results indicate that plasma P- selectin may be a useful new marker for thrombotic diseases.