The efficacy of ultraviolet light-emitting technology against coronaviruses: a systematic review.

The ongoing pandemic of COVID-19 has underlined the importance of adopting effective infection prevention and control (IPC) measures in hospital and community settings. Ultraviolet (UV)-based technologies represent promising IPC tools: their effective application for sanitation has been extensively evaluated in the past but scant, heterogeneous and inconclusive evidence is available on their effect on SARS-CoV-2 transmission. With the aim of pooling the available evidence on the efficacy of UV technologies against coronaviruses, we conducted a systematic review following PRISMA guidelines, searching Medline, Embase and the Cochrane Library, and the main clinical trials' registries (WHO ICTRP, ClinicalTrials.gov, Cochrane and EU Clinical Trial Register). Quantitative data on studies' interventions were summarized in tables, pooled by different coronavirus species and strain, UV source, characteristics of UV light exposure and outcomes. Eighteen papers met our inclusion criteria, published between 1972 and 2020. Six focused on SARS-CoV-2, four on SARS-CoV-1, one on MERS-CoV, three on seasonal coronaviruses, and four on animal coronaviruses. All were experimental studies. Overall, despite wide heterogenicity within included studies, complete inactivation of coronaviruses on surfaces or aerosolized, including SARS-CoV-2, was reported to take a maximum exposure time of 15 min and to need a maximum distance from the UV emitter of up to 1 m. Advances in UV-based technologies in the field of sanitation and their proved high virucidal potential against SARS-CoV-2 support their use for IPC in hospital and community settings and their contribution towards ending the COVID-19 pandemic. National and international guidelines are to be updated and parameters and conditions of use need to be identified to ensure both efficacy and safety of UV technology application for effective infection prevention and control in both healthcare and non-healthcare settings.

Stroke-like events after brain radiotherapy: a large series with long-term follow-up.

BACKGROUND AND PURPOSE: Patients with a history of brain radiotherapy can experience acute stroke-like syndromes related to the delayed effects of brain radiation, including stroke-like migraine attacks after radiation therapy syndrome, peri-ictal pseudoprogression and acute late-onset encephalopathy after radiation therapy syndrome. The aim of this study was to collect evidence on the long-term outcome and treatment of these conditions, whose knowledge is undermined by their rarity and fragmented description. METHODS: Cases were collected, both prospectively and retrospectively, amongst six neuro-oncology departments. Inclusion criteria were as follows: (i) history of brain radiotherapy (completed at least 6 months before the acute episode); (ii) new onset of acute/subacute neurological symptoms; (iii) exclusion of all etiologies unrelated to brain irradiation. A review of current literature on stroke-like syndromes was performed to corroborate our findings. RESULTS: Thirty-two patients with acute neurological conditions attributed to the delayed effects of radiation were identified, including 26 patients with stroke-like syndromes. Patients with stroke-like syndromes commonly presented with a mosaic of symptoms, including focal deficits (77%), encephalopathy (50%), seizures (35%) and headache (35%). Seventy-three percent of them had acute consistent magnetic resonance imaging alterations. Treatment included high-dose steroids in 65% of cases. Twenty-two patients recovered completely (85%). Sixteen patients (62%) experienced relapses (median follow-up 3.5 years). A literature review identified 87 additional stroke-like cases with similar characteristics. CONCLUSIONS: Stroke-like events related to brain irradiation may be associated with permanent sequelae. Steroids are often administered on empirical grounds, as they are thought to accelerate recovery. Relapses are common, highlighting the need to elaborate adequate prevention strategies.

Combined central and peripheral demyelination: Clinical features, diagnostic findings, and treatment.

Combined central and peripheral demyelination (CCPD) is rare, and current knowledge is based on case reports and small case series. The aim of our study was to describe the clinical features, diagnostic results, treatment and outcomes in a large cohort of patients with CCPD. Thirty-one patients entered this retrospective, observational, two-center study. In 20 patients (65%) CCPD presented, after an infection, as myeloradiculoneuropathy, encephalopathy, cranial neuropathy, length-dependent peripheral neuropathy, or pseudo-Guillain-Barré syndrome. Demyelinating features of peripheral nerve damage fulfilling European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) electrodiagnostic criteria for CIDP were found in 23 patients (74%), and spatial dissemination of demyelinating lesions on brain MRI fulfilling the 2010 McDonald criteria for multiple sclerosis (MS) in 11 (46%). Two thirds of the patients had a relapsing or progressive disease course, usually related to the appearance of new spinal cord lesions or worsening of the peripheral neuropathy, and showed unsatisfactory responses to high-dose corticosteroids and intravenous immunoglobulins. The clinical presentation of CCPD was severe in 22 patients (71%), who were left significantly disabled. Our data suggest that CCPD has heterogeneous features and shows frequent post-infectious onset, primary peripheral nervous system or central nervous system involvement, a monophasic or chronic disease course, inadequate response to treatments, and a generally poor outcome. We therefore conclude that the current diagnostic criteria for MS and CIDP may not fully encompass the spectrum of possible manifestations of CCPD, whose pathogenesis remains largely unknown.

Effect of complete androgen blockade on pathologic stage and resection margin status of prostate cancer: progress pathology report of the Italian PROSIT study.

OBJECTIVES: To compare the pathologic stage and surgical margin status in patients undergoing either immediate radical prostatectomy or surgery preceded by 3 or 6 months of neoadjuvant hormonal treatment (NHT) in a prospective, randomized study. METHODS: Four hundred thirty-one men with prostate cancer were enrolled in the Italian randomized prospective PROSIT study. The whole-mount sectioning technique was used. By May 1999, the reviewing pathologist had evaluated 303 specimens. One hundred seven patients were untreated before radical prostatectomy was performed, and 114 and 82 patients had been treated for 3 and 6 months, respectively, with complete androgen blockade. RESULTS: Pathologic organ-confined disease was found in 63.1% of patients with clinical Stage B disease treated with 6 months of NHT versus 61.0% after 3 months of NHT and 37.5% after immediate surgery. Among patients with clinical Stage C tumors, pathologic staging found organ-confined disease in 62.5%, 32.1%, and 11.1% of patients after 6 months of NHT, 3 months of NHT, and immediate surgery, respectively. Three months of NHT produced a significant increase in negative margins both in patients with clinical Stage B and C disease, but the addition of another 3 months of treatment did not significantly improve this result. A lower degree of benefit was observed in patients with clinical Stage C tumors. CONCLUSIONS: This study shows that complete androgen blockade before surgery is beneficial in men with clinical Stage B disease. The effects are more pronounced after 6 months of NHT than after 3 months.

Surgical pathology examination of radical prostatectomy specimens. Updated protocol based on the Italian TAP study.

Between January 1996 and June 2000, 192 men with prostate cancer underwent radical retropubic prostatectomy (RP) and bilateral pelvic node dissection in 26 centers participating in the Italian randomized prospective TAP study. The reviewing pathologist evaluated 145 RP specimens. Seventy-five cases had not been treated with total androgen ablation before RP was performed, whereas 70 had been treated for three months. Whole-mount sectioning of the complete radical prostatectomy specimens was adopted in each center for accurately evaluating the pathological stage of prostate cancer and resection limit status. The results of this study suggest that total androgen ablation before RP is beneficial in men with clinical stage T2 because of the significant pathological down-staging and decrease in the number of positive margins in the RP specimens. On the basis of the experience acquired through the Italian TAP study and recent publications on prognostic factors in prostate cancer, the original practice protocol for examination of RP specimens removed from patients with carcinoma of the prostate glands was updated.

[Sarcomatoid carcinoma of the kidney associated with urothelial carcinoma: report of a case with unusual clinical presentation]. / Carcinoma sarcomatoide del rene associato a carcinoma uroteliale: descrizione di un caso con inusuale presentazione clinica.

We report a case of sarcomatoid renal cell carcinoma and simultaneous transitional cell carcinoma of the renal pelvis in a 77 year old man admitted for uroseptic fever persisting for two months. Seven years earlier he underwent cystectomy with ureterosigmoidostomy for transitional cell carcinoma of the bladder. CT scan described a severe hydronephrosis with dilated pelvis, several pseudocystic formations with renal parenchima thinning and absence of contrast excretion. Radical nephrectomy was performed consequent to a clinical diagnosis of uroseptic fever in secondary hydronephrosis due to stenosis of ureterosigmoidostomy. Tumors were suspected on cut section and confirmed by histological examination.

Effect of total androgen ablation on pathologic stage and resection limit status of prostate cancer. Initial results of the Italian PROSIT study.

The likelihood of finding organ-confined untreated prostate cancer (PCa) by pathological examination at the time of radical prostatectomy (RP) is only 50% in patients with clinically organ-confined disease. In addition, tumour is present at the resection margin in approximately 30% of clinical T2 (clinical stage B) cases. The issue of clinical "understaging" and of resection limit positivity have led to the development of novel management practices, including "neoadjuvant" hormonal therapy (NHT). The optimal duration of NHT is unknown. We undertook the present analysis to evaluate the effect of NHT on pathologic stage of PCa and resection limit status in patients with prostate cancer and treated with total androgen ablation either for three or six months before RP. Between January 1996 and February 1998, 259 men with prostate cancer underwent radical retropubic prostatectomy and bilateral pelvic node dissection in the 26 centres participating in the Italian randomised prospective PROSIT study. Whole mount sectioning of the complete RP specimens was adopted in each centre for accurately evaluating the pathologic stage and resection limit status. By February 1998, haematoxylin and eosin stained sections from 155 RP specimens had been received and evaluated by the reviewing pathologist (RM). 64 cases had not been treated with total androgen ablation (e.g. NHT) before RP was performed, whereas 58 and 33 had been treated for three and six months, respectively. 114 patients were clinical stage B whereas 41 were clinical stage C. After three months of total androgen ablation, pathological stage B was more prevalent among patients with clinical B tumours, compared with untreated patients (57% in treated patients vs. 36% in untreated). The percentage of cancers with negative margins was statistically significantly greater in patients treated with neoadjuvant therapy than those treated with immediate surgery alone (69% vs. 42%, respectively). After six months of NHT therapy the proportion of patients with pathological stage B (67% vs. 36%, respectively) and negative margins was greater than after 3 months (92% vs. 42%, respectively). For clinical C tumours, the prevalence of pathological stage B and negative margins in the patients treated for either 3 or 6 months was not as high as in the clinical B tumours, when compared with the untreated group (pathological stage B: 31% and 33% vs. 6% in the clinical C cases, respectively. Negative margins: 56% and 67% vs. 31%, respectively). The initial results of this study suggest that total androgen ablation before RP is beneficial in men with clinical stage B because of the significant pathological downstaging and decrease in the number of positive margins in the RP specimens. These two effects are more pronounced after six months of NHT than after three months of therapy. The same degree of beneficial effects are not observed in clinical C tumours.

Metastases of the ureteral stump and bladder from renal cell carcinoma: report of a case.

The case of a 56 year-old male patient with asynchronous isolated metastases to the ureteral stump and bladder from renal cell carcinoma is presented. Ureteral metastasis was discovered 2 years after nephrectomy. Cystoscopy and MRI were performed. An excision of the ureteral stump with a cuff of bladder was carried out. No other metastasis was observed. Six months later a transurethral resection was performed on account of metastasis of the right wall of the bladder. Pathological examination demonstrated a renal cell carcinoma metastasis. After 6 months a new vesical metastasis from renal cell carcinoma was found. The small nodule of the lower part of the right wall of the bladder was removed. The literature is reviewed and the presentation, metastatic pathways, management of ureteral stump and bladder metastases from renal cell carcinoma are discussed.

Color Doppler sonography patterns related to histological findings in Graves' disease.

The aim of this work was to correlate color duplex sonography (CDS) patterns and thyroid histology in hyperthyroid Graves' disease (GD) patients. Sixteen patients with relapsed GD were studied. Before starting a new cycle of medical therapy with methimazole in decreasing doses for 3 to 6 months (baseline study), the patients underwent functional, autoimmune, and CDS studies. The same studies were carried out again just before surgery (presurgical study) after medical therapy had produced a normalization of thyroid hormone serum levels. The thyroid glands were histologically examined and their patterns were compared with CDS patterns. Thirty-three normal subjects were used as a control group. At baseline, 6 patients (group I) had intraparenchymal homogeneous vascular color spots or diffusely distributed over the parenchyma lobe or in areas alternating with avascular zones (CDS-A pattern). In 8 patients (group II) the thyroid had vascular bands with avascular or poorly vascularized parenchymal areas (CDS-B pattern). In 2 patients, the 2 patterns were present in the same thyroid (A-B pattern or mixed pattern). In these 2 patients the histological aspects were more similar to the CDS-B pattern than the CDS-A pattern. The 2 groups of patients differed in the velocity of systolic peak (VP) that was significantly higher in group I than in group II. In the presurgical study, no changes relative to CDS patterns were observed in patient groups I and II. The VP did not show any appreciable modifications in either group of patients. The thyrotropin-stimulating antibodies (TRAb) returned to normal levels in group II, but not in group I. The 2 CDS patterns, observed in the baseline study, were histologically characterized either by a richly vascularized parenchyma with prevalent endothelial hyperplasia (parenchymatous goiter, CDS-A) or by fibrotic septation with prevalent vascular intimal hyperplasia (CDS-B). In conclusion, this CDS study in GD patients showed 2 distinct vascular patterns. The thyroid glands were histologically characterized by either a richly capillary vascularized parenchyma (parenchymatous goiter, CDS-A aspect) or by fibrotic septation with prevalent intraseptal arteriolar-like hyperplasia (fibrous goiter, CDS-B aspect). Such differences may be secondary to a different duration of hyperthyroidism and/or intensity of TRAb thyroid stimulation.

Apoptosis in prostatic adenocarcinoma following complete androgen ablation.

OBJECTIVE: To analyze the cell death phenomenon in prostate cancer following complete androgen ablation. METHODS: The frequency and location of apoptotic bodies (ABs) were evaluated in haematoxylin and eosin stained sections of radical prostatectomy specimens from patients with invasive prostatic adenocarcinoma treated with neo-adjuvant endocrine combination therapy for 3 months before surgery. The results were compared with an untreated age- and stage-matched control group. RESULTS: Both in treated and untreated prostate tissue the AB frequency increased from normal prostate, through prostatic intraepithelial neoplasia, up to prostatic adenocarcinoma. The main location was in the cell layers adjacent to the stroma, their frequency decreasing towards the lumen. The frequency of ABs was higher in the treated prostate glands than in the untreated groups. The relative increase of the AB frequency in treated carcinomas as compared with untreated ones was lowest in tumours with a solid pattern, intermediate in the cribriform, and highest in the acinar pattern. CONCLUSIONS: Complete androgen ablation induces involution of prostate tissue mainly through the enhancement of apoptosis. This type of cell death is thought to play a major role and might be linked to specific changes in signal transduction mechanisms in response to hormonal withdrawal.

Subtle changes in benign tissue adjacent to prostate neoplasia detected with a Bayesian belief network.

The aim of this paper was to test the usefulness of a Bayesian belief network (BBN) as a decision support system in the uncertainty assessment of benign prostatic tissue, either associated or not with inflammation or adjacent to prostatic adenocarcinoma (PAC) or prostatic intraepithelial neoplasia (PIN). A shallow network was used with eight first-level descendant nodes for the diagnostic clues, each independently linked by a conditional probability matrix to a root node containing the diagnostic alternatives. One diagnostic evidence node was based on the tissue architecture and the others were based on cell features. The efficacy of the network was tested on a series of 45 simple prostatectomy specimens, subdivided as follows; benign prostatic tissue not associated with other diseases (15 cases), associated with acute and/or chronic inflammation (15 cases), and adjacent to accidentally discovered PAC or PIN (15 cases). The highest belief values for the diagnostic alternative normal prostate (NP) were obtained in the 15 cases not associated with other diseases, the mean value being 0.996. The 15 cases evaluated in areas with inflammation showed the lowest belief values for NP (mean 0.774). For the 15 cases evaluated in specimens with PAC or PIN, the belief values for NP were intermediate between those from normal prostatic tissue associated with inflammation and those not associated (mean 0.925). Moreover, it was found that subtle changes were also present at a certain distance from the tumour. In conclusion, the network can be used as a decision support system to differentiate with high certainty benign prostate adjacent to PAC or PIN from benign prostatic tissue either associated or not with inflammation. The subtle morphological alteration detected with the BBN may be considered malignancy-associated changes.

Evaluation of prostatic intraepithelial neoplasia after treatment with a 5-alpha-reductase inhibitor (finasteride). A methodologic approach.

OBJECTIVE: To develop a methodology applicable to the morphologic study of the efficacy of finasteride on prostatic intraepithelial neoplasia (PIN), a putative precursor of prostate cancer. STUDY DESIGN: Three PIN foci were reviewed in two simple prostatectomy specimens from patients with clinical diagnoses of benign prostatic hyperplasia and treated with finasteride for six months. The feasibility of PIN diagnosis and grading based on "diagnostic distance" was investigated. It is a measure of the "extent" to which the observed features are different from those of the untreated prototypes representing the following diagnostic categories: normal prostate, low and high grade PIN and prostatic adenocarcinoma with a cribriform or large acinar pattern. Uncertainty in the PIN diagnosis and grading was dealt with by means of a Bayesian belief network (BBN). RESULTS: The distance measure values of the three PIN foci from the prototype of untreated, nonneoplastic prostate were 9, 7 and 8, respectively, in relative, arbitrary units. Their distance from the two prostate cancer patterns (large acinar and cribriform) was as high as 8-10. The distance of these foci from either low or high grade PIN were as low as 5, 3 and 2, and 3, 5 and 4, respectively. BBN produced the highest belief values for PIN, thus confirming the morphology-based and diagnostic distance-supported diagnosis; however, the belief values were low for both grades. CONCLUSION: The results provided by BBN analyses and diagnostic distance measures support the conclusion that this methodology is applicable to assessing the efficacy of finasteride treatment of PIN.

TGF-beta 1 immunohistochemistry in goiter: comparison of patients with recurrence or no recurrence.

The aim of this work was to establish whether the immunohistochemical pattern for TGF-beta 1 in goiters that recur after thyroid surgery is different when compared with goiters that do not recur postoperatively. Twelve goiters, surgically removed by partial resection between 1977 and 1982, were studied. Ten years after surgery, 6 patients had recurrence of goiter or thyroid nodules (group 1); the others did not have any recurrence (group 2). The presence and location of TGF-beta 1 were evaluated a posteriori by immunohistochemistry in histological samples of the tissue that was removed. In each goiter specimen, 50 randomly selected subcapsular follicles were studied to evaluate the percentage of follicles negative or positive for TGF-beta 1 and the protein's intrathyrocyte location. In the slides of group 1, the percentage of TGF-beta 1-positive follicles was statistically (p < 0.01) greater (93.1%) than in group 2 (71.4%). No difference in the location of TGF-beta 1 was found. The authors found a greater percentage of positive follicles for the TGF-beta 1 protein in group 1 patients. In conclusion, TGF-beta 1 production in goiter is variable, time dependent, and may be a marker of active cellular proliferation due to chronic exposure to a goitrogen stimulus. Thus, the more TGF-beta 1 found, the more the cell is stimulated and, therefore, the greater the risk of relapse.

TGF beta 1 immunostaining patterns and locations in adenoma which later recurred.

To investigate whether the immunohistochemical pattern of TGF beta 1 may be a marker of relapse for adenomatous pathology, 18 follicular adenomas, surgically removed by hemithyroidectomy between 1977 and 1982, were studied. The adenomas were divided into two groups according to the presence (group 1, N = 9) or absence (group 2, N = 9) of nodules recurring in the residual thyroid tissue. The presence and location of TGF beta 1 were evaluated a posteriori by immunohistochemistry in the removed adenoma. Fifty randomly selected subcapsular follicles were studied in each adenoma in order to evaluate the percentage of positive follicles and TGF beta 1 intra-thyrocyte location. In adenoma of group 1, the percentage of positive follicles for TGF beta 1 was lower (80%) than in adenoma of group 2 (84%); this was, however, not statistically significant. The location of TGF beta 1 was mainly at the cell base of the epithelial cells in the microfollicles of group 1, but was dominant at the cell apex in group 2 (p < 0.01). In conclusion, adenoma recurrence is independent of TGF beta 1 production; it may be due to an abnormal TGF beta 1 regulation in response to hyperplasiogenic stimuli.

Enhanced expression of transforming growth factor beta1 in rat thyroid hyperplasia is thyrotropin induced and time dependent.

Forty-three 8-week-old male Wistar rats were studied to evaluate temporal changes of transforming growth factor beta1, (TGF-beta1) mRNA levels in thyroid tissue during pharmacologically induced goiter. Four rats were treated with purified bovine thyrotropin (TSH; Ambinon, 2 mU/day sc) for 7 days before being sacrificed. Thirty-one were treated with propylthiouracil (PTU), added to their drinking water at a concentration of 0.2 g%, and subsequently were sacrificed as follows: five after 1 week (PTU-1): five after 2 weeks (PTU-2); five after 4 weeks (PTU-4); five after 8 weeks (PTU-8); five after 12 weeks (PTU-12). In six rats, after 12 weeks of treatment. PTU was withdrawn for 2 months and subsequently started again in three rats which were sacrificed after 2 weeks (PTU-R); the remaining three rats were sacrificed without any further treatment (PTU-R control). Eight rats (control rats) were never treated and served as controls. After sacrifice, blood was drawn for determination of total thyroxine and the thyroid was excised and subdivided into two lobes. Northern analysis for TGF-beta1 was performed in one lobe. while histological and immunohistochemical studies were performed in the other lobe. Gene expression of TGF-beta1 was induced in TSH- and PTU-treated rats. In TSH-treated rats TGF-beta1 gene expression was less detectable than in PTU-treated rats, where it became evident after 2 weeks and remained through weeks 4-8. Gene expression of TGF-beta1 wits also seen in PTU-R rats, but not in the control and in the PTU-R control. Immunohistochemical analysis showed a different presence and location for the TGF-beta1 protein, which appears to be dependent on the time of exposure to mitogenic stimulus. In conclusion, TGF-beta1 is produced in response to both a direct (TSH by itself) and indirect (TSH induced by PTU-induced hypothyroidism) cellular proliferative stimulus and is not linked to an adaptative phenomenon secondary to hypothyroidism. The immunohistochemical location of TGF-beta1 within the thyrocytes is influenced by mitogen exposure time. A TGF-beta1 immunohistochemical evaluation may be important to define exposure time and activity of goitrogenic stimuli.

Analysis of the capillary architecture in the precursors of prostate cancer: recent findings and new concepts.

OBJECTIVE: To report on recent findings and new concepts in the remodeling of the capillary architecture in the precursors of prostate cancer. METHODS: Immunohistochemical methods have been adopted in prostate cancer and in its precursors (prostatic intra-epithelial neoplasia) to investigate capillary pattern changes-which were mainly analyzed as capillary frequency- and the degree of endothelial cell proliferation. Several features related to the capillary architecture have been considered. Manual, semiautomatic, and automatic (machine vision) types of evaluation have been used to quantify the features. RESULTS: The data available indicate that: (1) Going from normal prostate through prostatic intra-epithelial neoplasia up to invasive adenocarcinoma, an increasing proportion of capillaries becomes shorter, with open lumen and undulated external contour and with greater proliferation of the endothelial cells and greater expression of type IV collagenase. The highest proportion of touching capillaries is seen in normal prostate, while the lowest is found in invasive adenocarcinoma, being intermediate in prostatic intra-epithelial neoplasia. (2) When total androgen ablation is induced, there is no proliferation of the endothelium, whereas the capillaries are reduced in frequency and represented by small vessels lined by flat endothelial cells and with an open lumen. (3) Automation in the evaluation of the capillary architecture is feasible with a machine vision system. CONCLUSIONS: The progression in prostate carcinogenesis is associated with changes in the capillary architecture. There are some preliminary data indicating that total androgen ablation can inhibit the angiogenesis in precursors of prostate cancer.

Androgen-deprived prostate adenocarcinoma: evaluation of treatment-related changes versus no distinctive treatment effect with a Bayesian belief network. A methodological approach.

OBJECTIVE: To develop and test a Bayesian belief network (BBN) for the identification of prostatic adenocarcinomas (PACs) with combination endocrine therapy (CET) changes from PACs with poor to no treatment CET effect and from untreated PACs. METHODS: A network was designed with a decision node containing three diagnostic alternatives (PAC with CET effect, PAC with poor to no treatment effect, and untreated PAC) and seven first-level evidence nodes for the diagnostic features: nuclear enlargement; frequency of prominent nucleoli; cell cytoplasm vacuolization; shrunken acini; individual infiltrating tumor cells; WHO prostate cancer pattern recognition, and amount of interstitial tissue stroma. Three prototype cases, one for each diagnostic alternative, were used to develop the BBN. The BBN performance was then evaluated in 40 prostatectomies for PAC, consisting of 20 CET treated and 20 untreated cases. RESULTS: The results obtained with the three prototypes showed that the network can identify the diagnostic alternatives with certainty when seven features are polled. When the performance was evaluated in the 40 PACs, the belief values were 1.0 or close to it in most of the cases (the value range is 0.0-1.0; the closer to 1.0, the greater the belief). Moreover, the BBN allowed an identification with high certainty of PACs with treatment-related changes from those either with poor to no treatment effect or untreated. CONCLUSIONS: A BBN for the evaluation of androgen-deprived PAC offers a descriptive classifier which is readily implemented and allows the use of descriptive, linguistic terms.

Quantitative evaluation of nucleolar features on cytologic material in brain tumor diagnosis.

Nucleolar-related features were quantified in toluidin blue-stained smears from 36 brain tumors in order to improve our knowledge of the nucleolar frequency, size and margination. It was observed that low-grade astrocytic tumors had high percentages of nucleolated cells but the nucleoli were mostly single with maximum nucleolar diameter smaller than 2.00 microns. The percentages of marginated nucleoli were also low, ranging between 3.00% and 30.00% (only one case had a higher percentage). The high-grade tumors, i.e. anaplastic astrocytomas and glioblastomas, did not significantly differ from low-grade astrocytomas in their percentages of nucleolated nuclei, but they showed a higher number of nuclei having three or more nucleoli and the mean nucleolar diameter was in general bigger than 2.00 microns. Glioblastomas had marginated nucleoli much more frequently than anaplastic astrocytomas, the percentage in all but one case being higher than 30.00%. The percentage of marginated nucleoli was much higher in glioblastomas than in metastases, while the nucleoli were bigger in the latter group. A wide range of values for most of the nucleolar-associated parameters was observed in the remaining non-astrocytic brain tumors. Our results, showing differences in nuclear number, size and margination in different brain tumors, lead us to consider it worthwhile to investigate nucleolar-related features and their relationships using a quantitative approach.

MRI and pathological examination of post-mortem brains: the problem of white matter high signal areas.

We examined 21 brains from individuals more than 65 years of age by MRI and neuropathological methods to study the frequency and morphology of white matter changes. There were 16 brains from neurologically normal subjects (Group 1) while the remaining 5 (Group 2) had neurological disturbances. In Group 1 MRI showed high signal areas in the periventricular white matter in 12 brains and in the deep white matter in 9. All had focal areas, with confluent zones in 4; 3 cystic infarcts were also detected. Neuropathology in this Group showed periventricular changes of variable extent in all cases, vacuolated myelin around the perivascular spaces in 14 and degenerate myelin in 4. Macroscopic inspection showed 3 cystic lacunar infarcts, while areas of recent infarction were present on histology in 2. Four of the Group 2 brains had periventricular MRI changes; high signal areas in deep white matter were focal in 2 and confluent in 1. Cystic infarcts were detected in 3 cases. Neuropathology showed periventricular changes in all the brains; in 4 myelin around the perivascular spaces was vacuolated while degenerate myelin was demonstrated in 1. There were also old (1) and recent (2) lacunar infarcts. High signal areas in the white matter thus have different histological backgrounds but only in a minority of cases do they seem to be of pathological significance and, as a rule, they are not related to the presence of neurological disturbances. Correlative MRI-neuropathological studies are helpful for characterising abnormalities detected by techniques, like MRI, which are sensitive but not very specific.