Prediction of prostate carcinoma stage by quantitative biopsy pathology.

BACKGROUND: Considerable evidence has shown that the use of computational algorithms to combine pretreatment clinical and pathology results can enhance predictions of patient outcome. The aim of this study was to prove that the application of such methods to predict patient-specific likelihoods of organ-confined (OC) prostate carcinoma (PCA) may be helpful to patients and physicians when they are choosing an optimal treatment for carcinoma of the prostate. METHODS: The authors used clinical and quantitative pathology results from the biopsy specimens of 817 PCA patients who had been evaluated at a large national pathology reference laboratory. The pathology parameters that were measured included the number of positive cores, Gleason grades and score, percentage of tumor involvement, and the tumor location. The pathologic stage of these cases, as determined by results from radical prostatectomy, lymphadenectomy, or bone scan, categorized the PCA as either OC, non-OC due to capsular penetration only (NOC-CP) or advanced disease with metastasis (NOC-Mets), i.e., seminal vesicle and/or lymph-node positive or bone-scan positive. There were a total of 481 OC cases, 185 NOC-CP cases, and 151 NOC-Mets cases. Patient-specific prediction models were trained by ordinal logistic regression (OLOGIT) and genetically engineered neural networks (GENNs), and the resulting trained models were validated by biopsy information from an independent set of 116 PCA patients. RESULTS: When the authors applied a cutoff of >or= 35% for the n = 817 training set of OC, NOC-CP, and NOC-Mets predictive probabilities, the OLOGIT model predicted OC PCA with an accuracy of 91%, whereas the GENN model predicted the same with an accuracy of 95%. When the authors employed the n = 116 validation set (76 OCs, 31 NOC-CPs, and 9 NOC-Mets), the OLOGIT and GENN models correctly identified OC PCA with 91% and 97% accuracy, respectively. CONCLUSIONS: The value of combining patient pretreatment diagnostic pathology parameters to make predictions concerning the postoperative extent of pathology was illustrated clearly in this study. This finding further confirms the need to pursue such approaches for PCA disease management in the future, especially with the increasing prevalence of clinical T1c (American Joint Committee on Cancer, 1977) disease.

Abuse of guaifenesin-containing medications generates an excess of a carboxylate salt of beta-(2-methoxyphenoxy)-lactic acid, a guaifenesin metabolite, and results in urolithiasis.

OBJECTIVES: Several urinary calculi were submitted to our institution for compositional analysis. The typical techniques of analysis, polarized light microscopy, electron microprobe analysis, and infrared spectroscopy proved inadequate for a definitive identification. As a result, a more detailed organic analysis was conducted to determine the exact chemical structure of the material. METHODS: Infrared spectroscopy and mass spectrometric analysis were carried out on the solid material, providing information concerning the functional groups and the molecular mass of the organic constituent and its components. The stone was solubilized in deuterated solvents and analyzed by nuclear magnetic resonance spectroscopy, which resulted in a definitive chemical structure. RESULTS: The spectroscopic analysis indicated that the stones were composed of a calcium salt of beta-(2-methoxyphenoxy)-lactic acid, a metabolite of the pharmaceutical guaifenesin, which is used as an expectorant. CONCLUSIONS: Guaifenesin, an expectorant common in over-the-counter cold and allergy remedies, can cause urolithiasis if taken in excess. Discussions with physicians and their patients confirmed that most patients admitted to taking large doses of guaifenesin-containing medications.

Glioblastoma multiforme of the hippocampus in advanced Alzheimer's disease.

An 87-year-old woman suffered from Alzheimer's disease diagnosed 6 years prior to her death. Autopsy showed in addition to far-advanced Alzheimer's disease, a large, partially necrotic glioblastoma occupying her right hippocampus. Occurrence of a glial neoplasm in Alzheimer's disease could well be coincidental, since both entities are fairly common in elderly individuals; it is however, uncommon for gliomas to centre on the hippocampus itself. For these reasons it is possible (although cannot be proven from a single case), that florid reactive gliosis commonly associated with Alzheimer's disease, may have played a role in eventually initiating neoplastic proliferation of astrocytes in this patient.