Low free to total PSA ratio is not a good discriminator of chronic prostatitis and prostate cancer: An Indian experience.

Aims: To find out the utility of free to total PSA ratio in discriminating chronic prostatitis and prostate cancer. Setting and design: The patients visited urology clinics at Batra Hospital and Medical Research Center, New Delhi. Background: The use of serum free to total PSA as a diagnostic tool for prostate cancer has led to early detection of prostate cancer; however, the effect of inflammation on f/t PSA ratio restricts its use in early detection of cancer. Materials and Methods: The study was conducted in age related 101 patients which include 27 carcinoma patients (group I), 34 BPH patients (group II) and 40 chronic prostatitis patients (group III). Serum total PSA (tPSA) and free PSA (fPSA) were analyzed on Elecsys 2010. These were compared with histological reports of biopsy specimen. Other biochemistry tests were done on Randox Imola. P Value was calculated using one way ANOVA with posthoc Bonferroni analysis. Results: Serum total PSA levels were comparable in group I and III and were higher than group II (P < 0.049). Serum fPSA in group I was not significantly different from group II and III, However, group II has higher levels than group III (P < 0.035). Difference was significant for f/t PSA ratio in group I and II (P < 0.00) and group II and III (P < 0.000).Group I and III were with comparable levels (P < 0.807). Conclusions: f/t PSA ratio is not a good discriminator for malignancy and chronic prostatitis. This limitation of f/t PSA ratio must be taken into consideration while interpreting the results clinically.

Study of CT three-dimensional reconstruction combined with Fisher discriminant in the atypical benign or malignant pulmonary nodules / 实用放射学杂志

Objective To assess the dignosis value of CT three-dimensional reconstruction with Fisher discriminant model in small solitary pulmonary nodules before operation.Methods CT data of 40 cases with SPN were retrospectively analyzed and divided into into malignant pulmonary nodules (25 cases),squamous cell carcinoma (4 cases),adenocarcinoma (13 cases),lung cancer (4 ca-ses),small cell lung cancer (2 cases),large cell carcinoma (1 case),metastases tumor (1 case),benign nodules (1 5 cases,6 cases of tuberculosis,2 cases of hamartoma,and 7 cases of non-specific inflammatory nodules)by pathology and follow-up results.The CT features of pulmonary nodules were evaluated through multi-planar reformation (MPR),curved-planar reformation (CPR),volume rendering (VR),maximum intensity proj ection (MIP)and other three-dimensional reconstruction.The three-dimensional data were divided into benign and malignant groups.In each of the two groups,the significant signs of morphological signs of discrimination indicators were adminstrated Fisher discriminant,and the probalitiy of false positives were estimated using cross-validation method. Results The positive features of pulmonary nodules in there-dismensional images were much more than in two-dimensional images. Fisher discriminant formula of solitary pulmonary nodules in three-dimensional images was Z=1.143X1 + 0.454X2+1.606X3-0.262X4+0.04X5+0.483X6+1.611X7-2.164.Discriminant boundary value Zc was-0.516.When Zcgreater than -0.516,nodules were proneed to considere as malignant nodules.In 25 cases of malignant nodules,4 cases mistook for benign.When Zc less than -0.516,nodules were proneed to considere as benign nod-ules.In 1 5 benign nodules,2 cases mistook for malignant.The total misdiagnosis and accuracy rate were 15 % and 85% respec-tively.Conclusion CT three-dimensional reconstruction combined with Fisher discriminant model have a high clinical value in dif-fereiating diagonsis of pulmonary nodules were proneed to considere as malignant nodules.In 25 cases of malignant nodules,4 cases mistook for benign.When Zc less than -0.516,nodules were proneed to considere as benign nodules. In 15 benign nodules,2 cases mistook for malignant.The total misdiagnosis and accuracy rate were 15 % and 85% respec-tively.Conclusion CT three-dimensional reconstruction combined with Fisher discriminant model have a high clinical value in differeiating diagonsis of pulmonary nodules.

CARACTERIZACIÓN DEL TALLO ACEPTOR DEL tARN MEDIANTE DESCRIPTORES LOCALES BASADOS EN CARGAS PARCIALES / tRNA ACCEPTOR STEM CHARACTERIZATION BY MEANS OF LOCAL DESCRIPTORS BASED ON PARTIAL CHARGES / CARACTERIZAÇÃO DO TALO ACEITADOR DO tRNA MEDIANTE DESCRITORES LOCAIS BASEADOS EM CARGAS PARCIAIS

En este trabajo se caracteriza la distribución de carga del tallo aceptor del tARN, considerando todas las posibles combinaciones de pares Watson-Crick. El estudio se realizó con 256 fragmentos moleculares de 10 nucleótidos que modelan los tres primeros pares del tallo aceptor, la base diferenciadora y el extremo CCA. Para caracterizar los nucleótidos se proponen dos descriptores locales basados en la distribución de carga de la base nitrogenada de cada nucleótido, los cuales se calculan a partir de las cargas parciales de Mulliken obtenidas de cálculos HF/6-31G. La caracterización y clasificación de los tallos según estos descriptores mostró cómo la base diferenciadora tiene un comportamiento particular respecto a los demás nucleótidos del tallo y una fuerte influencia sobre el extremo CCA. La clasificación de nueve variaciones del tallo aceptor del tARNAla mostró una buena relación estructura-actividad que pone en evidencia la bondad de los descriptores propuestos para caracterizar de manera local la distribución de carga de estas biomoléculas.

In this work the charge distribution of the tRNA acceptor stem is characterized, considering all the possible Watson- Crick base pair combinations. 256 RNA fragments modeled by 10 nucleotides were used in order to model the first three pairs of the acceptor stem, the discriminator base and the CCA end. We propose two local charge descriptors based on the charge distribution of the nitrogenated base to characterize each nucleotide. These descriptors were computed from atomic partial charges derived from HF/6-31G calculations. From the characterization and classification of the stems according to the proposed descriptors, we found a special behavior for the discriminator base (in contrast to the other positions) and a strong effect of this position on the CCA end. The classification of nine variations of the tRNAAla acceptor stem showed a good structure-activity relationship that makes evident the usefulness of the proposed descriptors to characterize the local charge distributions of these biomolecules.

Nesse estudo é caracterizada a distribuição da carga do talo aceitador considerando- se todas as combinações possíveis dos pares Watson-Crick. O estudo realizouse com 256 fragmentos moleculares dos 10 nucleotídeos que modelam os três primeiros pares do talo aceitador, a base diferenciadora e o extremo CCA. Com o intuito de caracterizar cada nucleotídeo, foram propostos dois descritores locais baseados na distribuição de carga da base nitrogenada de cada nucleotídeo, os quais se calculam a partir das cargas parciais de Mulliken obtidas de cálculos HF/6-31G. A caracterização e classificação dos talos segundo esses descritores demonstrou um particular comportamento da base diferenciadora em relação aos demais nucleotídeos do talo e uma forte influência sobre o extremo CCA. A classificação de nove variações do talo aceitador do tRNA mostrou uma boa relação estrutura-atividade que colocam em evidência a utilidade dos descritores propostos para caracterizar de maneira local a distribuição de carga dessas bio-moléculas.