Diagnosis of prostatic carcinoma: value of random transrectal sonographically guided biopsies

OBJECTIVE: We studied the efficacy of random, transrectal sonographically guided biopsies in the diagnosis of prostatic carcinoma in a high-risk population. SUBJECTS AND METHODS: During a 2-year period, 570 transrectal sonographically guided prostatic biopsies were done because of clinical findings suggestive of prostatic carcinoma. Biopsies of hypoechoic lesions that were suggestive of carcinoma and segmental random biopsies of normal-appearing lobes of the prostate were performed. Transrectal sonographic findings were correlated with results of pathologic examination of the biopsy specimen and with surgical results, when available. RESULTS: Of the 202 patients found to have carcinoma, the carcinoma was detected with directed biopsy in 145 patients (72%). One hundred twenty (71%) of 169 carcinomas were detected with random biopsy when that procedure was performed. Random biopsies were the only method of diagnosing 57 (28%) of the 202 carcinomas, increasing the yield by 39%. CONCLUSION: Yield of carcinoma on transrectal sonographically guided biopsies increases significantly when segmental random biopsies are performed. Transrectal sonographically guided biopsies should include cores through hypoechoic lesions that are suggestive of carcinoma and bilateral segmental random biopsies.     

Relating chemical activity to structure: An examination of ILP successes

Problems concerned with learning the relationships between molecular structure and activity have been important test-beds for Inductive Logic programming (ILP) systems. In this paper we examine these applications and empirically evaluate the extent to which a first-order representation was required. We compared ILP theories with those constructed using standard linear regression and a decision-tree learner on a series of progressively more difficult problems. When a propositional encoding is feasible for the feature-based algorithms, we show that such algorithms are capable of matching the predictive accuracies of an ILP theory. However, as the complexity of the compounds considered increased, propositional encodings becomes intractable. In such cases, our results show that ILP programs can still continue to construct accurate, understandable theories. Based on this evidence, we propose future work to realise fully the potential of ILP in structure-activity problem.     

SCH 45752--an inhibitor of calmodulin-sensitive cyclic nucleotide phosphodiesterase activity

A highly potent inhibitor of calmodulin-sensitive phosphodiesterase (PDE) activity was isolated from the culture broth of an unidentified fungal isolate, SCF-125. A chemically defined medium was developed for production of this compound. The PDE inhibitor was isolated from the fermentation filtrate by adsorption on a macro-reticular resin and further purified by gel filtration chromatography and reverse-phase HPLC. The major PDE inhibitor was identified as cephalochromin, a bis-naphthopyrone, by spectral data analysis. The compound, SCH 45752, inhibited calmodulin-sensitive PDE activities with IC50 values of 40-47 nM. It inhibited the activities of calmodulin-independent PDE and various protein kinases with higher IC50 values (2-40 microM). SCH 45752 does not appear to be a calmodulin antagonist. Furthermore, SCH 45752 affects smooth muscle contraction at a concentration of 30 microM; it potentiated the relaxing effect of sodium nitroprusside on carotid artery media contracted by histamine. Thus SCH 45752 is one of the most potent inhibitors of calmodulin-sensitive PDE activity known, and it is capable of exerting a pharmacological effect in at least one intact tissue model.     

Temperature and flow modulation doping of manganese in ZnS electroluminescent films by low pressure metalorganic chemical vapor deposition

A temperature and flow modulation (TFM) technique has been developed to modulate the manganese doping profile in ZnS phosphor material grown by lowpressure metalorganic chemical vapor deposition for alternating-current thin film electroluminescent devices (TFELDs). In the TFM technique, modulation of both the substrate temperature as well as the flows of metalorganic sources, diethylzinc and tricarbonyl-(methylcyclopentadienyl)-manganese (TCPMn), was used to grow a structure consisting of alternating layers of undoped ZnS at 400°C and Mn-doped ZnS where Mn being incorporated into the undoped ZnS at 550°C. X-ray results indicated that MnS_x phases were present within the ZnS host crystal matrix for the modulation doped samples, while a Mn_xZn_1-xS solid solution was present in the uniformly doped samples. The luminescence efficiency of the TFELDs could be modified by growing the phosphor with dopant (luminescent center) modulation. The TFELDs with a single modulated doping phosphor layer showed lower threshold voltages in the range 70 to 80 V with light emission in the 580 to 587 nm wavelength range. With a twofold increase in the total thickness of the undoped ZnS layer, the brightness and the luminescence efficiency, measured at the threshold voltage plus 40 V, increased by a factor of 20 and 10, respectively. The electroluminescent (EL) characteristics of the phosphors with multiple dopant layers showed higher luminescence efficiency. By using the TFM growth technique, one can engineer the luminescent center distribution in the phosphor layer to improve the EL characteristics.     

Coronary reoperations: indications and results

The aim of this study was to assess the results of coronary reoperations and to determine the indications. Between January 1972 and December 1990, 166 coronary reoperations were performed in 161 patients (5 patients were operated three times). The interval between the first and second operation was 93 +/- 46 months. The interval between recurrence of symptoms and reoperation was 27 +/- 40 months. Recurrence of symptoms was related to isolated problems with the bypass grafts in 23% of cases, to an aggravation of the coronary disease without problems with the bypass grafts in 17% of cases and to an association of the two conditions in 60% of cases. Mortality in the first 30 postoperative days was 7.8% (13/161). The predictive factors of mortality were age over 70 years and an interval between recurrence of symptoms and reoperation of over 12 months. The causes of death were myocardial infarction (n = 5), left ventricular failure (n = 4), sudden death (n = 3), and arrhythmias (n = 1). The average follow-up period of survivors (n = 134) was 40 +/- 32 months. Four patients have been transplanted. Seven patients died secondarily. The cause of death was cardiac in 4 cases and non-cardiac in 3 cases. The actuarial 5 year and 10 year survival rates were 85 +/- 3%. Actuarial absence of myocardial infarction, angina, Class III-IV cardiac failure and transplantation was 87 +/- 4% at 5 years and 69 +/- 10% at 10 years. These figures show that coronary reoperation gives good functional results and long-term survival.(ABSTRACT TRUNCATED AT 250 WORDS)     

Current induced on single and crossed electrically short and thin tubular cylinders by a normally incident plane electromagnetic wave

The currents induced in electrically thin conducting tubes are evaluated from the general solution of the coupled integral equations derived by C. C. Kao [5] in the form of transverse Fourier components. It is shown that on a single cylinder of length2hand radiusain a normally incidentE-polarized field with wavenumberk, the rotationally symmetric zero-order term dominates forka leq 0.1and increases in magnitude askais reduced, but only whenkh > 1. Under these conditions, supplemented with the inequalitya ll h, thin-cylinder theory is valid. The relatively small first-order term produces small departures from rotational symmetry that increase or decrease the current on the illuminated side depending on the condition of axial resonance and the location of the cross section in the standing-wave pattern. Askhis reduced so thatka < kh ll 1, the rotationaily symmetric part of the axial current decreases and becomes negligible compared to the first-order current which is proportional tocos theta. Thin-cylinder theory is then no longer useful. When two electrically thin tubes intersect, thin-wire theory and junction conditions determine only the rotationally symmetric part of the axial currents in the arms. These dominate only when the arms of the cross are not electrically short. The fast-order nonrotationally symmetric components of the axial current and the transverse currents can be determined from the incident magnetic field. They dominate when the arms of the cross are electrically short. The significance of the surface currents and charges on aircraft illuminated by an electromagnetic wave or pulse at low frequencies is pointed out.     

A closed-form linear multi-step algorithm for the steady-state response of high-speed flexible mechanismsEin schlie ungsformiger linearer mehrschrittalgorithmus zur bestimmung stationarer erzwungener schwingungen von schnell-aufenden elastischen mechanismen

Based on the general form of linear multi-step methods, a closed-form algorithm for the steady-state solution of periodically time-dependent vibrating systems—high-speed flexible mechanisms with uniform rotation input can be taken as a special case—is developed. The algorithm is tested by three examples and verified by comparing the computational responses with the previously published experimental results. Besides, the computational results also show that this algorithm, compared with Fourier series method, is of higher accuracy and far higher computational efficiency.