Laccase isoform diversity in basidiomycete Lentinus strigosus 1566: Potential for phenylpropanoid polymerization.

Three laccase isoforms with different physicochemical properties could be purified from culture liquid of basidiomycete Lentinus strigosus 1566 obtained during submerged cultivation. The purified laccases possessed individual selectivity in relation to different phenolic compounds. Laccases I, II, and III (59, 65, and 61 kDa respectively) were more active in acidic conditions at around 70 °C. However, in contrast to laccases I and II, laccase III retained its activity (8-30%) and stability during at least one week of incubation at neutral conditions that allows its biotechnological application carried out at neutral environment. The activation phenomena for some of the purified laccases from L. strigosus 1566 during incubation at high temperature, different pH, and sulfates is shown and discussed. According to MALDI-TOF analysis, laccases I and II are most closely related to the laccase of Panus rudis (AAR13230). Transformation of phenylpropanoids by the predominant laccases of L. strigosus 1566 to different polymers was demonstrated, indicating a great potential for producing novel pharmaceutical valuable analogues of lignans, stilbenes, flavonoids, and etc.. The studied laccases, which are products of the same strain, can become a convenient model for further studies of the structural mechanisms of the shift of T-/pH-optima, activation, and T-/pH-stability.

In the radiotherapy of prostate cancer, technique determines the doses to the penile structures.

For 11 consecutive prostate cancer patients undergoing three-dimensional conformal radiotherapy (3DCRT) in our institution, penile structures (PNS) were outlined in CT images obtained for treatment planning purposes. Dose-volume histograms (DVHs) were compared in order to study dose-volume relations for three techniques: 4FLD, an axial coplanar, four-field box technique; 6FLD, a six-field coplanar technique; and 4NAX, a coplanar but non-axial, four-field technique. All three techniques delivered equal doses to the planning target volumes (PTV). Our statistical analyses strongly indicate that the three techniques can be ranked as 6FLD better than 4FLD (and 4FLD better than 4NAX) as far as irradiating PNS volume during treatment of prostate cancer (PC) is concerned. For each technique, there is a "spread" owing to differences in patient anatomy and/or target size, position, and extent, but each technique has a similar "profile" or "shape" distinct from other techniques. Whether irradiating smaller volumes of PNS will influence the sexual potency outcome remains to be demonstrated. However, PNS should be considered as another critical structure in addition to rectum, bladder and femoral heads in the radiotherapy (RT) of PC, especially in 3DCRT dose escalation studies. Sexual potency outcomes can be correlated to dose-volume relations in the future and this will help refine radiotherapy techniques further.

Thyroid nodules in the follow-up of irradiated individuals: comparison of thyroid ultrasound with scanning and palpation.

In 1974 we began a prospective study of a cohort of 4296 individuals exposed to therapeutic head and neck irradiation during childhood for benign conditions. To define the role of thyroid ultrasonography in following irradiated individuals, we studied a subgroup of 54 individuals. They all had been screened between 1974-1976 and had normal thyroid scans and no palpable nodules at that time. Thyroid ultrasonography, thyroid scanning, physical examination, and serum thyroglobulin measurements were performed. One or more discrete ultrasound-detected nodules were present in 47 of 54 (87%) subjects. There were a total of 157 nodules, 40 of which were 1.0 cm or larger in largest dimension. These 40 nodules occurred in 28 (52%) of the subjects. Thirty (75%) of these 1.0-cm or larger nodules matched discrete areas of diminished uptake on corresponding thyroid scans. The 10 that did not match (false negative scans for > or = 1.0-cm nodules) were the only nodules of this size in 7 subjects. Of 11 nodules 1.5 cm or larger, only 5 were palpable. Serum thyroglobulin correlated to the number (P = 0.04; r2 = 0.10), but not the volume of the thyroid nodules (P = 0.07; r2 = 0.08). We conclude that thyroid nodules are continuing to occur and are exceedingly common in this irradiated cohort of individuals. The results confirm that thyroid ultrasonography is more sensitive than physical examination and scanning. However, thyroid ultrasound is so sensitive and nodules so prevalent that great caution is needed in interpreting the results.

MR imaging of the forefoot: normal anatomic findings.

The MR imaging anatomy of the ankle has been well described. The anatomy of the forefoot, however, is not well understood by most radiologists. In many institutions, MR imaging studies are performed by using the head coil with large fields of view so that the appearance of the asymptomatic side can be used for comparison. At our institution, studies of the forefoot are performed with a specialized solenoid coil that allows a field of view of 8 cm with a resultant in-plane spatial resolution of approximately 0.3-0.4 mm. In this report, we present the MR imaging anatomy of the normal forefoot. Pertinent osseous, musculotendinous, and neurovascular structures are shown. Particular emphasis is placed on the compartmental anatomy of the foot, which is best imaged in the coronal plane.