Biomedical subjects
Publications and source records attributed to L Cozzi.
A mechanical device for a multileaf delineator, designed and built in our department, is described. Its scope is used as an accessory mounted on the head of the radiation therapy simulator to obtain reliable images of the treatment field, shaped for multileaf collimation, on the patient's skin and to record them on the reference X-ray films normally acquired during the simulation phases.
We report the case of a 21 years old man with renal cholics in whom the diagnosis of renal hydatid disease was established by FNA. Considering the high risk of anaphylactic shock reactions and dissemination of daughter cysts, the use of FNA for the diagnosis of hydatid disease has to be limited to unexpected cases with unusual primary localization.
AIM: We studied the immunophenotype of 9 cases of secretory meningioma (SM), a rarely reported meningioma variant, characterized by small gland-like lumina filled with a PAS-positive, diastase-resistant substance. METHODS: Three samples of arachnoid tissue and 9 SMs were studied with a panel of monoclonal antibodies (MoAbs) against cytokeratins (Ck) 7,8, 20, vimentin, EMA, CEA and the mucin epitopes sialyl-Tn, Tn, CA19.9, CA125, against the BerEP4 and CD15; 3 colonic adenocarcinomas metastatic to the brain and a case of meningioma with metastasis from a gastric signet-ring cell carcinoma were also studied with the same panel of MoAbs for comparison. RESULTS: The 3 samples of arachnoid cap cells were positive only for EMA and vimentin in the supportive stroma. All 9 SMs resulted Ck7+, Ck8+, Ck20-, EMA+, CEA and mucin epitopes+, confirming at an immunohistochemical level the glandular differentiation. Notable exceptions were the negativity for BerEP4 and CD15 antigens. Conversely, the 3 metastatic colonic adenocarcinomas to the brain were Ck7-, Ck8+, Ck20+, CEA and mucin epitopes+, BerEP4 and CD15+; the gastric signet-ring cell carcinoma metastatic to a meningioma showed the same immunophenotype as the other metastatic adenocarcinomas with the exception of BerEP4 negativity. CONCLUSION: The different pattern of cytokeratin expression (Ck7+/Ck20- for SMs, and Ck7-/ Ck20+ for adenocarcinomas) and the negativity for BerEP4 and CD15 epitopes of SMs, could be relevant for the distinction between SMs and metastatic adenocarcinomas.
Cytopathological findings on three pedriatic gonadic-extragonadic pure yolk sac tumor are reported: the highly variable histological patterns (reticular, solid, festooning or pseudopapillary, polyvesicular vitelline), reflecting differentiation towards extraembryonic yolk sac structures, are not appreciated in cytologic samples. Since the tumor's cytologic spectrum is very broad, the most diagnostic differential difficulty with yolk sac tumor is adenocarcinoma. The presence of intracellular and extracellular hyaline globules, that are periodic acid-Schiff stain (PAS) positive and diastase resistant and correspond to alpha-fetoprotein production, alpha-fetoprotein positivity of the neoplastic cells; showing nuclear pleomorphism and vacuolated "bubbly" cytoplasm are the most consistent cytologic hallmarks of this neoplasm, which diagnosis would be confirmed by histologic, immunocytochemical and clinical findings.
BACKGROUND AND PURPOSE: The study was aimed at investigating the feasibility and accuracy of an in vivo quality assurance program in radiotherapy. Breast irradiation was found to be a relevant clinical model due to the fairly good uniformity of the irradiated tissue. MATERIALS AND METHODS: The investigation was based on an extension of the method described by Leunens et al. (Leunens, G., van Dam, J., Dutreix, A. and van der Schueren, E. Quality assurance in radiotherapy by in vivo dosimetry. 1. Entrance dose measurements, a reliable procedure. Radiother. Oncol. 17: 141-151, 1990; Leunens, G., van Dam, J., Dutreix, A. and van der Schueren, E. Quality assurance in radiotherapy by in vivo dosimetry. 2. Determination of the target absorbed dose. Radiother. Oncol. 19: 73-87, 1990; van Dam, J. and Marinello, G. Methods for in vivo dosimetry in external radiotherapy. Physics for clinical radiotherapy. ESTRO Booklet n. 1 (Garant), 1994), determining the absorbed dose at any point on the central axis from a measurement of entrance and exit doses with individually calibrated and corrected diodes. Treatment accuracy (delta) was quantified as the ratio of the measured and the expected isocentre dose from the treatment planning system (TPS). RESULTS: A preliminary study was carried out on a Plexiglas slab phantom to test the method ending with a frequency distribution of delta with a mean of 0.04 +/- 0.05% and a standard deviation (SD) of 0.83 +/- 0.04%. In the in vivo study, 101 patients irradiated with two tangential fields were included in the protocol over a 1-year period. The total number of patient set-ups analyzed was 421 giving a distribution of delta with a mean of -1.3 +/- 0.2% and an SD of 2.7 +/- 0.1% without any correction. Taking into account temperature effects and set-up errors as SSD accuracy and diodes positioning it was possible to implement an off-line correction method leading to a final distribution with a mean of -1.9 +/- 0.2% and an SD of 2.4 +/- 0.1%. Individual cases with large deviations were detected and evaluated and actions were undertaken whenever possible. CONCLUSIONS: The study showed that diodes can be easily used by radiographers in an accurate in vivo quality assurance (QA) program and that an accuracy level of 3% at 1 SD can be reached on average. Attention and action levels can also be identified and careful evaluation of positioning and morphological variations during treatment should be part of a comprehensive QA program.
The Hounsfield units into density conversion for a commercial treatment planning system (TPS) is discussed. The impact of an average calibration table provided by the manufacturer on computed doses was investigated when a customer calibration could not be included in the TPS. The maximum error determined on the computed monitor units per Gy was found to be about 2%, being below 1% on average. The relative importance of the parameters used for CT image acquisition is also discussed. The applied voltage was the most relevant parameter leading to errors in the reconstructed Hounsfield numbers of about 300 units for high densities.
Kynureninase [E.C.3.7.1.3.] is one of the enzymes involved in the biosynthesis of NAD cofactors from tryptophan through the kynurenine pathway. By tryptic and CNBr digestion of purified rat liver kynureninase, we obtained about 28% of the amino acid sequence of the enzyme. The rat kynureninase cDNA, isolated by means of reverse-transcribed polymerase chain reaction and hybridization screening, codes for a polypeptide of 464 amino acids. Northern blot analysis revealed the synthesis of a 2.0 kb rat kynureninase mRNA. A cDNA encoding human liver kynureninase was also isolated. The deduced amino acid sequence is 85% identical to that of the rat protein. COS-1 cells were transfected with both cDNAs. The Km values of the rat enzyme, for L-kynurenine and DL-3-hydroxykynurenine, were 440 +/- 20 microM and 32 +/- 5 microM and of the human enzyme 440 /- 20 microM and 49 +/- 6 microM, respectively. Interestingly, COS-1 cells transfected with the cDNA coding for rat kynureninase also display cysteine-conjugate beta-lyase activity.
We report a case of Leydig cell tumor of the testis in a young man, in whom preoperative diagnosis was achieved by fine-needle aspiration biopsy cytology. Cytology, histology, and ultrastructural examination showed diagnostic Reinke's crystals, both in nuclei and in cytoplasm. Immunohistochemistry displayed strong vimentin and estrogen positivity.
Okadaic acid, the main toxin of the diarrhoetic shellfish poisoning (DSP) group, shows high cytotoxicity to Buffalo green monkey (BGM) kidney cell cultures after different times according to concentration. A rapid method of detecting the presence of okadaic acid and related compounds in contaminated mussels by means of a cytotoxicity test is presented. The method is based on direct microscopic observation of toxin-induced morphological changes in BGM cell cultures. A high correlation (r = 0.950; P < 0.001) was found between the official mouse bioassay and the cytotoxicity test conducted on naturally contaminated samples of Mytilus galloprovincialis.
We describe the case of a 46-year-old male patient who presented with pain in the left thigh, often accompanied by lumbar pain. These symptoms were sustained by a neoplasm, which was located in the sympathetic ganglia, at the level of the 3rd left lumbar spinal root and which was completely excised. Immunohistochemical positivity for S100, HMB45, and NSE antibodies suggested that the lesion was a melanotic schwannoma (MS), with both schwannian and melanocytic differentiations, the latter containing melanosomes at ultrastructural examination. Non-recurrence after 16 months of follow-up further supports our diagnosis of MS.
We present the case of a woman in whom intraoperatory examination of a laterocervical mass in the right carotid triangle (thought to be a glomus tumor) disclosed thyroid tissue. Although the overwhelming majority of cases of "thyroid parenchyma in the laterocervical region" represent a lymph node metastasis from a primary occult thyroid carcinoma, the rare occurrence of a parasitic nodule, as in our case, must be considered.
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Wedge factor (WF) variation with field size and depth has been analysed for 6 and 15 MV X-ray beams. The measured field size effect is 1.4% in the worst case, whereas the WF shows a linear dependence with depth giving a maximum variation of 0.22%/cm (60 degrees wedge, 6 MV beam). An empirical correction for WF depth dependence on wedge thickness is proposed.
The potential role of sonography in evaluating the response to therapy of persistent knee joint synovitis (KJS) was assessed in a longitudinal study in pre-and post-arthroscopic (AS) synovectomy in rheumatoid and psoriatic patients. At entry to the study ultrasound (US) detection of synovial proliferation was compared with arthroscopic visualization as the 'gold standard' reference. US joint effusion and synovial thickness measures and predominant patterns of synovial proliferation were recorded by comparing clinical and US indices before and at 2, 6 and 12 months after AS synovectomy, or after KJS relapse up to 24 months. A 12 month survival analysis of clinical and US outcomes of arthroscopic synovectomy was also performed. US detection of morphology and degree of synovial proliferation was correlated with AS macroscopic evaluation. After AS synovectomy, the clinical index and both US joint effusion and synovial thickness were significantly reduced, whereas US patterns of synovial proliferation did not show significant changes. US and clinical indices were significantly correlated in all follow-up measurements and US joint effusion was significantly increased in the relapsed compared with the non-relapsed KJS group. The probability at 12 months of reaching maximum improvement in US joint effusion and synovial thickness outcomes was 99 and 58%, respectively; that for clinical remission of KJS was 72%. Ultrasound evaluation has proven reliable and accurate by the arthroscopic gold standard in detecting changes of rheumatoid arthritis and psoriatic arthritis knee joint synovitis. The correlation of US with clinical findings in pre-and post synovectomy patients suggests that sonography can be used as an objective method in monitoring the response to therapy of inflammatory knee joint disease.
A long-term prospective study was performed to evaluate the safety and long-term outcome of surgical arthroscopy (AS) for persistent rheumatoid (RA) and psoriatic (PsA) knee joint synovitis (KJS). Local signs of joint inflammation (tenderness, swelling, "ballottement') and range of motion (ROM) were scored and the sum, taken as a global outcome measure, was recorded in 17 RA and 18 PsA knees, both before and at follow-up periods of 2, 6, 12, 24 and 36 months after surgical AS (knee joint synovectomy; meniscal curettage, cartilage shaving or chondrectomy, according to the degree of cartilage damage). A survival analysis (Kaplan-Meier) of the long-term outcome of surgical AS treatment and of the predictive value of clinical parameters of knee joint involvement was also performed. No intra- or post-operative morbidity, pain worsening or loss of joint motion was observed and all patients were discharged within 48 h. Comparison of the parameters of knee joint evaluation showed a significant reduction of the signs of joint inflammation and a significant increase in the ROM in all follow-up periods. At 36 months, the survival curves showed a 61.2% cumulative probability of clinical remission and 72.8% of definite improvement. No significant differences in the prognostic importance of RA, compared to PsA diagnosis, were observed, although higher percentages of PsA compared to RA knees (86.3% and 45.7% respectively) reached the end point of clinical remission at 36 months. KJS duration, radiographic severity and cartilage damage were not predictors of poor long-term outcome of AS synovectomy. Surgical AS treatment for PsA knees with more advanced cartilage damage gave a better long-term outcome. A total of 50.7% of operated knees reached the end point of a KJS relapse at 36 months, the majority (82%) within the initial 18 months of follow-up. Our study indicates that AS synovectomy is a safe procedure requiring short hospitalization which, in combination with second-line medical treatment, can reduce local inflammation in RA and PsA KJS, and preserve knee joint ROM for up to 3 yr.
Hepatopancreas samples from mussels (Mytilus galloprovincialis) experimentally contaminated with okadaic acid were analysed with Yasumoto's mouse bioassay and HPLC. A likely effect of some components of the hepatopancreas on the results (matrix effect) was evaluated, and a possible loss of toxin during the extraction phase was quantified. Experiments were conducted by comparing two different extraction procedures. Under our experimental conditions, the results obtained from mouse bioassay showed no matrix effect with either procedure. A certain quantity of the actual amount of okadaic acid contained in the sample was found to be lost after the extraction, i.e. 10.2-17.0% in samples extracted with acetone alone and 9.8-18.5% in samples extracted with acetone and ether.
The enzyme kynurenine aminotransferase (KAT) catalyses the conversion of L-kynurenine to kynurenic acid. A combination of polymerase chain reaction techniques and hybridization screening was used to isolate a cDNA clone encompassing the entire coding region of KAT from rat kidney. Identification of the cDNA as coding for KAT was based both on the comparison of amino acid sequences obtained from purified rat KAT and on the expression of KAT activity in COS-1 cells transfected with the cDNA. RNA blot analysis indicated that KAT mRNA is widely expressed in rat tissues. Cultured cells transfected with the cDNA for KAT also showed glutamine transaminase K activity. Based mainly on sequence data, these results demonstrate that rat kidney KAT is identical with glutamine transaminase K.
Mussel specimens (Mytilus galloprovincialis) collected from two different areas of the Adriatic Sea were analysed for diarrhoetic shellfish poisoning (DSP) toxin by three methods: mouse bioassay, the DSP Check enzyme immunoassay kit, and high-performance liquid chromatography (HPLC). The results obtained confirm that Yasumoto's mouse bioassay, capable of detecting all the components of the DSP group, is still necessary to determine the wholesomeness of the product. The ELISA method has not always given quantitatively reliable results. The HPLC method is advantageous in terms of sensitivity, accuracy, specificity and rapidity. However, its application is limited so far to the determination of okadaic acid in mussels.