Size-strain separation in diffraction line profile analysis

Separation of size and strain effects on diffraction line profiles has been studied in a round robin involving laboratory instruments and synchrotron radiation beamlines operating with different radiation, optics, detectors and experimental configurations. The studied sample, an extensively ball milled iron alloy powder, provides an ideal test case, as domain size broadening and strain broadening are of comparable size. The high energy available at some synchrotron radiation beamlines provides the best conditions for an accurate analysis of the line profiles, as the size-strain separation clearly benefits from a large number of Bragg peaks in the pattern; high counts, reliable intensity values in low-absorption conditions, smooth background and data collection at different temperatures also support the possibility to include diffuse scattering in the analysis, for the most reliable assessment of the line broadening effect. However, results of the round robin show that good quality information on domain size distribution and microstrain can also be obtained using standard laboratory equipment, even when patterns include relatively few Bragg peaks, provided that the data are of good quality in terms of high counts and low and smooth background.

Mechanical activation of Efavirenz: the effects on the dissolution and inhibitory behavior

A poorly water-soluble drug (Efavirenz) was mechanically activated by ball-milling. The effect of the mechanical activation on the dissolution behavior and bioavailability was investigated revealing possible correlations with the grinding action, in terms of crystallinity, particle size and morphology.With proper selection of the grinding parameters the dissolution kinetics can be controlled, both in terms of dissolution velocity and as amount of dissolved drug. In vitro biological tests show that milling does not impair the ability of Efavirenz to inhibit HIV-1 infection (p value >0.05); the IC50 values of ground Efavirenz is indeed lower than values for the pristine micronized powder.

Debye-Waller coefficient of heavily deformed nanocrystalline iron

Extensive deformation of an iron alloy powder increases the static disorder contribution to the thermal factor, with an increase of ∼20% in the Debye–Waller coefficient observed by both X-ray diffraction and extended X-ray absorption fine structure. Molecular dynamics simulations shed light on the underlying mechanisms, confirming the major role played by the grain boundary.

Synchrotron radiation X-ray diffraction (XRD) patterns from an extensively ball-milled iron alloy powder were collected at 100, 200 and 300 K. The results were analysed together with those using extended X-ray absorption fine structure, measured on the same sample at liquid nitrogen temperature (77 K) and at room temperature (300 K), to assess the contribution of static disorder to the Debye–Waller coefficient (B_iso). Both techniques give an increase of ∼20% with respect to bulk reference iron, a noticeably smaller difference than reported by most of the literature for similar systems. Besides good quality XRD patterns, proper consideration of the temperature diffuse scattering seems to be the key to accurate values of the Debye–Waller coefficient. Molecular dynamics simulations of nanocrystalline iron aggregates, mapped on the evidence provided by XRD in terms of domain size distribution, shed light on the origin of the observed B_iso increase. The main contribution to the static disorder is given by the grain boundary, while line and point defects have a much smaller effect.

[Late recurrence of Wilms' tumor]

We present a patient with a Wilms' Tumor recurring after 7 years from the primitive surgical excision. After the relapse, surgery and conventional chemotherapy (with Actinomycin-D, Cyclophosphamide and Vincristine) permitted to achieve a second complete remission. Now the patient is alive without evidence of disease after 4 years from the relapse. The non-complete surgical excision of the tumor and the particular biological activity of the residual cells could explain the late relapse.

[Cerebral changes shown by computed tomography in children with acute lymphatic leukemia after therapy]

The authors discuss the CT findings of the late brain damage by the radiochemotherapic treatment for the prophylaxis of meningeal leukemia in 50 patients, 1 divided by 15 years old. The more frequent CT findings are: enlargement of the subaracnoid spaces; ventricular dilatation; hypodensity of cerebral parenchima; calcifications. These findings correspond to two clinical and anatomo-pathological conditions: subacute leucoencephalopathy and mineralizing microangiopathy. A greater damage on central nervous system was demonstrated in younger children (5 years old) at the time of prophylaxis of meningeal leukemia, that were irradiated with NSD = 950 ret.

Effect of peptichemio in nonlocalized neuroblastoma

PTC, a mixture of oligopeptides of m-L-sarcholysin, acting primarily as an alkylating agent, was utilized as initial therapy following diagnosis in 80 children with nonlocalized neuroblastoma. Of the 67 evaluable patients (21 Stage III, 41 Stage IV and five Stage IV-S), 51 had measurable lesions allowing to evaluate PTC activity; objective tumor responses to the drug were recorded in 45 of these 51 cases (88.2%); 5/5 Stage III, 37/41 Stage IV, 3/5 Stage IV-S. Complete responses were obtained in seven patients (13.7%), partial responses in 32 (62.7%), objective improvement in six (11.8%). Four patients (7.8%) had either no tumor change, or tumor progression. There have been two early drug-related deaths (3.9%). Stage III and IV patients responding to PTC were then treated by irradiation + VCR, followed by cycles of a combination of ADriamycin, vincristine, and cyclophosphamide. Stage IV-S patients received no further therapy. Thirteen of 21 Stage III (61.9%), five of 41 Stage IV (12.2%) and four of five Stage IV-S (80%) are presently alive from 19-48 months (median, 27 months). PTC is an effective agent in advanced neuroblastoma. However, the results of this report do not indicate that its addition to a "standard" treatment, at least in the schedule adopted in this protocol, has improved the final outcome of children with nonlocalized disease.

Congenital hypoplastic anaemia developed in acute megakarioblastic leukaemia. A case report

A 14-month-old child with congenital hypoplastic anemia, in temporary remission after steroid therapy, developed an acute megakarioblastic leukemia. After complete remission due to immunosuppressive treatment, the leukemia rapidly relapsed, and the child died at 23 months of age. The rapid development of leukemia puts some doubt on the initial diagnosis.