A compact 7-cell Si-drift detector module for high-count rate X-ray spectroscopy.

A new Si-drift detector module for fast X-ray spectroscopy experiments was developed and realized. The Peltier-cooled module comprises a sensor with 7 × 7-mm2 active area, an integrated circuit for amplification, shaping and detection, storage, and derandomized readout of signal pulses in parallel, and amplifiers for line driving. The compactness and hexagonal shape of the module with a wrench size of 16mm allow very short distances to the specimen and multi-module arrangements. The power dissipation is 186mW. At a shaper peaking time of 190 ns and an integration time of 450 ns an electronic rms noise of ~11 electrons was achieved. When operated at 7 °C, FWHM line widths around 260 and 460 eV (Cu-Kα) were obtained at low rates and at sum-count rates of 1.7 MHz, respectively. The peak shift is below 1% for a broad range of count rates. At 1.7-MHz sum-count rate the throughput loss amounts to 30%.

Synaptic plasticity in spiking neural networks (SP(2)INN): a system approach.

In this paper, we present a digital system called (SP/sup 2/INN) for simulating very large-scale spiking neural networks (VLSNNs) comprising, e.g., 1000000 neurons with several million connections in total. SP/sup 2/INN makes it possible to simulate VLSNN with features such as synaptic short term plasticity, long term plasticity as well as configurable connections. For such VLSNN the computation of the connectivity including the synapses is the main challenging task besides computing the neuron model. We describe the configurable neuron model of SP/sup 2/INN, before we focus on the computation of the connectivity. Within SP/sup 2/INN, connectivity parameters are stored in an external memory, while the actual connections are computed online based on defined connectivity rules. The communication between the SP/sup 2/INN processor and the external memory represents a bottle-neck for the system performance. We show this problem is handled efficiently by introducing a tag scheme and a target-oriented addressing method. The SP/sup 2/INN processor is described in a high-level hardware description language. We present its implementation in a 0.35 /spl mu/m CMOS technology, but also discuss advantages and drawbacks of implementing it on a field programmable gate array.

NeuroPipe-Chip: A digital neuro-processor for spiking neural networks.

Computing complex spiking artificial neural networks (SANNs) on conventional hardware platforms is far from reaching real-time requirements. Therefore we propose a neuro-processor, called NeuroPipe-Chip, as part of an accelerator board. In this paper, we introduce two new concepts on chip-level to speed up the computation of SANNs. These concepts are implemented in a prototype of the NeuroPipe-Chip. We present the hardware structure of the prototype and evaluate its performance in a system simulation based on a hardware description language (HDL). For the computation of a simple SANN for image segmentation, the NeuroPipe-Chip operating at 100 MHz shows an improvement of more than two orders of magnitude compared to an Alpha 500 MHz workstation and approaches real-time requirements for the computation of SANNs in the order of 10(6) neurons. Hence, such an accelerator would allow for applications of complex SANNs to solve real-world tasks like real-time image processing. The NeuroPipe-Chip has been fabricated in an Alcatel 0.35-mum digital CMOS technology.

Esophageal motility disorders in critically ill patients: a 24-hour manometric study.

OBJECTIVE: Impaired tubular esophageal motility is involved in the pathogenesis of gastroesophageal reflux disease, which, in turn, has been shown to cause nosocomial pneumonia in critically ill patients. As multiple factors are involved, this pilot study was undertaken to evaluate whether, similarly, impaired esophageal motility may contribute to nosocomial infections by determining esophageal motility in critically ill patients undergoing mechanical ventilation and sedation in comparison to that of a healthy control group. DESIGN: Open, single-centered study. PATIENTS AND METHODS: Fifteen consecutive ventilated intensive care unit (ICU) patients with different diseases and three regimens of analgo-sedation were included: group 1: no analgo-sedation, group 2: ketamine and benzodiazepines, and group 3: fentanyl and benzodiazepines. Six healthy volunteers were studied as controls. Twenty-four hour esophageal anterograde (propulsive) and retrograde motility changes were assessed by a manometry system. RESULTS: The frequencies of contractions were 0.67 +/- 0.1/min (no analgo-sedation) 0.093 +/- 0.02 (ketamine) and 0.076 +/- 0.01 (fentanyl) (p < 0.05 as compared to controls). The amplitudes (% of maximum) were 98 % (control), 58 % (analgo-sedation), 38 % (ketamine) and 42 % (fentanyl; p < 0.05 for the comparison of fentanyl and ketamine with controls). Whereas the percentage of propulsive contractions was significantly decreased in patients (no sedation: 45 %, ketamine: 34 %; fentanyl: 35 %, p < 0.05) as compared to controls (72 %), the percentage of retrograde contractions increased: no sedation: 29 %, ketamine: 34 % and fentanyl: 37 % as compared to controls: 10 %, p < 0.05. Analysis according to the underlying diseases showed marked inhibition of motility parameters within any disease group in comparison with controls. CONCLUSIONS: Irrespective of the underlying disease, propulsive motility of the esophageal body is significantly reduced during any kind of sedation in critically ill patients. Possibly central as well peripheral drug-related effects are involved in such a depression. Twenty-four hour motility recordings appear to be a valuable and feasible method to quantify and analyze esophageal motor disorders in critically ill patients.

[Evaluation of a rapid qualitative test for cardiac troponin T in clinical diagnosis of patients with acute coronary syndrome]. / Evaluierung eines qualitativen Schnelltestes für kardiales Troponin T zur präklinischen Diagnostik bei Patienten mit akutem Koronarsyndrom.

OBJECTIVE: To evaluate the practical performance and the diagnostic power of a rapid, qualitative assay for the detection of cardiac Troponin T (indicated cut-off level: 0.3 ng/ml) in EMS patients presenting with acute myocardial ischemia. PATIENTS: 145 consecutive patients with non-traumatic chest pain treated by the Mobile Intensive Care Unit team. During phase 1 (73 patients), blood drawn at the emergency site was used to perform a Troponin T rapid assay under defined conditions at the hospital. During phase 2 (72 patients), the rapid assay was already performed at the emergency site. RESULTS: In phase 1 all tests were performed correctly, whereas 5.6% of the test results had to be declared invalid in phase 2. 17 (11.7%) of the 145 patients showed a positive test result. Analytic sensitivity was 100%, specificity 96.3%. 37 of the 145 patients (median duration of symptoms: 150 minutes) showed a myocardial infarction (MI). Related to the diagnosis of MI diagnostic sensitivity, specificity, positive and negative predictive values were 35.1, 96.3, 76.5, and 81.3%. Mortality in patients with a positive rapid assay was 35.3%, compared to 6.3% in patients with a negative test result (p < 0.001). CONCLUSIONS: The rapid assay allows the detection of Troponin T in concentrations above the cut-off level. Meticulous observance of the manufacturer's rules is imperative. A single preclinical rapid assay does not allow to exclude a MI. However, the test enables EMS personnel to identify patients who are at increased risk of dying from an acute coronary syndrome in the immediate future.

Assessing axis II disorders by informant interview.

Although much of personality disorder research depends on diagnostic data obtained directly from patients, this approach has rarely been compared to interviews with knowledgeable informants. The purpose of this study was to determine the diagnostic agreement between these two assessment methods, as well as their relative contribution to the formulation of consensus diagnoses. Sixty-two psychiatric patients were assessed directly with the Structured Interview for DSM-III Personality Disorders (SIDP), and were asked to nominate an informant--either a family member or friend--to provide information about the patient in an interview with the same instrument. Informant interviews were conducted blind to patient-based information whenever feasible, and diagnostic consensus was achieved by an independent review of all available data by a senior clinician. Diagnostic agreement between patient-based and informant-based personality disorder interview was poor, confirming the findings of two previous studies. Information obtained from patients tended to be given greater weight in formulating consensus diagnoses than information provided by informants. However, about one quarter of diagnostic disagreements were resolved in favor of informant-based information. In contrast to a previous study, the inclusion of informant information did not appear to reveal greater psychopathology in patients. We conclude that supplementing direct patient interview with data provided by a knowledgeable informant appears to enhance the resolution of some personality disorder diagnoses. The utility of informant interviews may depend on an analysis of the costs and benefits of this additional degree of descriptive refinement.

[Trauma diagnosis: difficulty in differentiating between recall and fantasy]. / Diagnose Trauma: Die Schwierigkeit der Unterscheidung zwischen Erinnerung und Fantasie.

This paper is intended as a contribution to understanding why, up until recently, there have been so few case reports of actual abuse and its sequelae in the psychoanalytic literature. We suggest that psychoanalytic insights into the nature of psychic reality, while indispensable to the evolution of psychoanalytic thinking, have nonetheless had the adverse effect of collapsing any distinction between unconscious fantasies and repressed memories. Moreover, the idea that knowledge of external reality is itself mentally constructed also has diminished interest in uncovering trauma and "real" history. We present a report of an adult analysis that illustrates the recovery of a dissociated memory of sexual abuse that occurred during adolescence, as a springboard to discuss problems analysts have had in dealing with trauma theoretically. We hypothesize that repressed memories and unconscious fantasies can often be distinguished insofar as they may "be stored" or encoded differently, and that consequently the sequelae of trauma and fantasy often, but not always, can be disentangled. We describe some different modes of encoding trauma and some different ways of remembering, re-experiencing, and re-enacting it. And, finally, we suggest why traumatic memories are increasingly accessible to patients today.

Brief solution-focused strategies for behavioral pediatrics.

In an era of shrinking resources and managed care, brief models of psychotherapy are receiving increasing attention. One of the newest and innovative of those, brief, solution-focused therapy, is particularly efficient, because it concentrates on the present and the future; builds on strengths; focuses on clear, realistic goals; uses tasks; and develops client cooperation and efficacy. Parents have long turned to pediatricians for help in addressing a variety of child-rearing and other family concerns. Behavioral pediatricians who are looking for time-effective ways to counsel families should consider the six solution-focused techniques described in this article and pursue training in this approach to family therapy, yet another example of family-focused pediatrics.

Symptom prevalence, characteristics and distress in a cancer population.

Despite the importance of symptom control in the cancer population, few studies have systematically assessed the prevalence and characteristics of symptoms or the interactions between various symptom characteristics and other factors related to quality of life (QOL). As part of a validation study of a new symptom assessment instrument, inpatients and outpatients with prostate, colon, breast or ovarian cancer were evaluated using the Memorial Symptom Assessment Scale and other measures of psychological condition, performance status, symptom distress and overall quality of life. The mean age of the 243 evaluable patients was 55.5 years (range 23-86 years); over 60% were women and almost two-thirds had metastatic disease. The Karnofsky Performance Status (KPS) score was < or = 80 in 49.8% and 123 were inpatients at the time of assessment. Across tumour types, 40-80% experienced lack of energy, pain, feeling drowsy, dry mouth, insomnia, or symptoms indicative of psychological distress. Although symptom characteristics were variable, the proportion of patients who described a symptom as relatively intense or frequent always exceeded the proportion who reported it as highly distressing. The mean (+/- SD range) number of symptoms per patient was 11.5 +/- 6.0 (0-25); inpatients had more symptoms than outpatients (13.5 +/- 5.4 vs. 9.7 +/- 6.0, p < 0.002) and those with KPS < or = 80 had more symptoms than those with KPS > 80 (14.8 +/- 5.5 vs. 9.2 +/- 4.9, p < 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Opioid responsiveness of cancer pain syndromes caused by neuropathic or nociceptive mechanisms: a combined analysis of controlled, single-dose studies.

We performed a combined analysis of the results from four controlled single-dose relative-potency studies to assess the impact of inferred pain mechanism on the response to an opioid drug. A total of 168 patients received 474 administrations of either morphine or heroin, and we assessed the analgesic response during a 6-hour period with visual analog scales. We summarized this as a total pain relief (TOTPAR) score. Two experienced pain clinicians reviewed information about pain characteristics and designated each case according to the inferred pain mechanism (neuropathic, nociceptive, or mixed) and the degree of confidence in the inferred mechanism (definite versus probable/possible). They grouped the cases as follows: nociceptive pain only (n = 205), neuropathic pain only (n = 49), and mixed (n = 220). We compared pain relief achieved by patients with different mechanisms, with TOTPAR adjusted for significant covariates (duration of prior opioid administration, doses of opioid administered in the previous 48 hours, pain intensity at the start of the study, BUN:creatinine ratio, and dose of administered opioid). The adjusted mean TOTPAR score of the group with any neuropathic pain was significantly lower than that of the group with nociceptive pain only (26.1 versus 20.4, p = 0.02). The score of the group with definite nociceptive pain alone (adjusted mean TOTPAR = 28.0) was significantly higher than scores of the groups with possible/probable nociceptive pain (TOTPAR = 19.9), mixed mechanisms (TOTPAR = 20.2), definite neuropathic pain alone (TOTPAR = 20.6), and possible/probable neuropathic pain alone (TOTPAR = 22.9).(ABSTRACT TRUNCATED AT 250 WORDS)

Familial correlates of reduced central serotonergic system function in patients with personality disorders.

BACKGROUND: To test the hypothesis that evidence of reduced central serotonergic (5-HT) system function in probands with personality disorders is associated with an elevated morbid risk of psychopathological conditions putatively associated with 5-HT dysfunction in first-degree relatives of these probands. METHODS: Data were collected during a study of the 5-HT correlates of behavior in male patients with DSM-III personality disorders conducted at a Veterans Affairs medical center. Probands in this study were selected from those patients who had undergone both a fenfluramine hydrochloride challenge and a family history assessment. Axis II diagnosis were made according to DSM-III criteria after a structured interview of the proband, using the Structured Interview for Diagnosing Personality Disorders, given by two raters and a similar interview with a knowledgeable informant by another rater. RESULTS: Reduced prolactin responses to the 5-HT releasing/uptake inhibiting agent fenfluramine was associated with an elevated morbid risk of impulsive personality disorder traits in the first-degree relatives of patients with a primary DSM-III diagnosis of a personality disorder. Quantitative scores on assessments of impulsive aggression in the probands were not correlated with an increased morbid risk for impulsive personality disorder traits. A trend in the same direction was noted for affective personality disorder traits and alcoholism. CONCLUSIONS: These results suggest that a central 5-HT system abnormality in probands is associated with an increased risk of impulsive aggression in their first-degree relatives, and that assessment of central 5-HT system function in probands may be a more sensitive parameter for identification of this familial trait than the presence of impulsive aggressive behaviors in the proband.

The Memorial Symptom Assessment Scale: an instrument for the evaluation of symptom prevalence, characteristics and distress.

The Memorial Symptom Assessment Scale (MSAS) is a new patient-rated instrument that was developed to provide multidimensional information about a diverse group of common symptoms. This study evaluated the reliability and validity of the MSAS in the cancer population. Randomly selected inpatients and outpatients (n = 246) with prostate, colon, breast or ovarian cancer were assessed using the MSAS and a battery of measures that independently evaluate phenomena related to quality of life. Symptom prevalence in the 218 evaluable patients ranged from 73.9% for lack of energy to 10.6% for difficulty swallowing. Based on a content analysis, three symptoms were deleted and two were added; the revised scale evaluates 32 physical and psychological symptoms. A factor analysis of variance yielded two factors that distinguished three major symptom groups and several subgroups. The major groups comprised psychological symptoms (PSYCH), high prevalence physical symptoms (PHYS H), and low prevalence physical symptoms (PHYS L). Internal consistency was high in the PHYS H and PSYCH groups (Cronback alpha coefficients of 0.88 and 0.83, respectively), and moderate in the PHYS L group (alpha = 0.58). Although the severity, frequency and distress dimensions were highly intercorrelated, canonical correlations and other analyses demonstrated that multidimensional assessment (frequency and distress) augments information about the impact of symptoms. High correlations with clinical status and quality of life measures support the validity of the MSAS and indicate the utility of several subscale scores, including PSYCH, PHYS, and a brief Global Distress Index. The MSAS is a reliable and valid instrument for the assessment of symptom prevalence, characteristics and distress. It provides a method for comprehensive symptom assessment that may be useful when information about symptoms is desirable, such as clinical trials that incorporate quality of life measures or studies of symptom epidemiology.

Establishing trauma: the difficulty distinguishing between memories and fantasies.

This paper is intended as a contribution to understanding why, up until recently, there have been so few case reports of actual abuse and its sequelae in the psychoanalytic literature. We suggest that psychoanalytic insights into the nature of psychic reality, while indispensable to the evolution of psychoanalytic thinking, have nonetheless had the adverse effect of collapsing any distinction between unconscious fantasies and repressed memories. Moreover, the idea that knowledge of external reality is itself mentally constructed also has diminished interest in uncovering trauma and "real" history. We present a report of an adult analysis that illustrates the recovery of a dissociated memory of sexual abuse that occurred during adolescence, as a springboard to discuss problems analysts have had in dealing with trauma theoretically. We hypothesize that repressed memories and conscious fantasies can often be distinguished insofar as they may be "stored" or encoded differently, and that consequently the sequelae of trauma and fantasy often, but not always, can be disentangled. We describe some different modes of encoding trauma and some different ways of remembering, reexperiencing, and reenacting it. And, finally, we suggest why traumatic memories are increasingly accessible to patients today.

Nativity, complications, and pathology are determinants of surgical results for gastric cancer.

BACKGROUND: About half the patients involved in the current study were born outside of the United States. Epidemiologic and histologic features and survival estimates were compared with persons born in the United States. Results of gastrectomy with lymph node dissection were studied. METHODS: Records of 187 patients with adenocarcinoma of the stomach were reviewed. Seventy-six with a curative gastrectomy were staged retrospectively. Univariate and multivariate analyses were done. RESULTS: Seventy-six percent of histologically reviewed curative resections had the intestinal subtype with the same frequency in U.S.-born and foreign-born patients. Fewer patients with proximal third lesions were foreign born. Thirty-six percent had complications. The overall 5-year Kaplan-Meier survival estimate was 46%: 77% for patients with negative nodes and 33% for patients with positive nodes. N1 survival estimate was 44%; N2, 25%; N3(M1), 0%. All six patients with early gastric cancer are alive 50-147 months after surgery. Other stage I patients had estimated survival of 65%; Stage II, 52%; Stage III, 40%; and Stage IV, 0%. Multivariate analysis revealed four significant prognostic variables: nativity, histologic subgroup, presence of complications, and number of positive nodes. CONCLUSIONS: Proximal gastric cancer was more common in U.S.-born persons. Gastric cancer may be more malignant in U.S.-born persons than in foreign-born persons because their survival was significantly poorer. Complications, a significant adverse factor, were more common in U.S. series. Pancreatectomy with gastrectomy is rarely indicated, because microscopic involvement is rare and complications frequent. The prognostic advantage of a regional lymphadenectomy remains unclear.

Long-term functional results of coloanal anastomosis for rectal cancer.

In a survey of patients treated with coloanal anastomosis for rectal cancer, 81 of 90 eligible patients responded to a questionnaire evaluating current anorectal function. Time from operation to assessment ranged from 1.3 to 12.3 years (median: 4.3 years). The median stool frequency was two per day; 22% of patients reported four or more stools per day. In the patients surveyed, fecal continence was complete in 51%, incontinence to gas only in 21%, minor leak in 23%, and significant leak in 5%. Complete evacuation of the neorectum was problematic in 32%. Overall function was excellent in 28%, good in 28%, fair in 32%, and poor in 12%. The impact of treatment variables on functional outcome was assessed by univariate and multivariate analyses. No surgical technique correlated with improved or impaired outcome. Time since surgery (reduced stool frequency) and use of postoperative adjuvant radiotherapy (increased stool frequency, increased difficulty with evacuation) did appear to influence functional outcome. We conclude that the functional results of coloanal anastomosis are good but not optimal. Continued investigation of the effects of surgical technique and adjuvant therapy is warranted.

Infectious morbidity associated with long-term use of venous access devices in patients with cancer.

OBJECTIVE: To evaluate infectious morbidity associated with long-term use of venous access devices. DESIGN: Prospective, observational study. SETTING: Comprehensive cancer center at a university hospital. PARTICIPANTS: 1431 consecutive patients with cancer requiring 1630 venous access devices for long-term use inserted between 1 June 1987 and 31 May 1989. MEASUREMENTS: Quantitative microbiologic tests to identify device-related bacteremia and fungemia, catheter tunnel infection, pocket infection in implantable port devices, and site infections; number of days the device remained in situ and time until infectious morbidity; vessel or device thrombosis and device breakage. RESULTS: At least one device-related infection occurred with 341 of 788 (43% [95% CI, 39% to 47%]) catheters compared with 57 of 680 (8% [CI, 6% to 10%]) completely implanted ports (P < or = 0.001). Device-related bacteremia or fungemia is the predominant infection occurring with catheters, whereas ports have a more equal distribution of pocket, site, and device-related bacteremia. The predominant organisms isolated in catheter-related bacteremia were gram-negative bacilli (55%) compared with gram-positive cocci (65.5%) in port-related bacteremia. The number of infections per 1000 device days was 2.77 (95% CI, 2.48 to 3.06) for catheters compared with 0.21 (CI, 0.16 to 0.27) for ports (P < or = 0.001). Based on a parametric model of time to first infection, devices lasted longer in patients with solid tumors than in those with hematopoietic tumors. Ports lasted longer than catheters across all patient groups. CONCLUSIONS: The incidence of infections per device-day was 12 times greater with catheters than with ports. Patients with solid tumors were the least likely to have device-related infectious morbidity compared with those with hematologic cancers. The reasons for the difference in infectious complications is uncertain but may be attributable to type of disease, intensity of therapy, frequency with which devices are accessed, or duration of neutropenia.

Long-term results of transhiatal esophagectomy for esophageal carcinoma. A multivariate analysis of prognostic factors.

BACKGROUND: Perioperative mortality and survival after esophagectomy have improved over the past 10 years. Although stage is the most powerful predictor of long-term survival, it remains unclear whether other factors influence prognosis. METHODS: Between 1981-1991, 100 patients with esophageal carcinoma were uniformly treated by transhiatal esophagectomy without adjuvant therapy. Results and prognostic factors of long-term survival were analyzed by univariate and multivariate analyses (log-rank test and Cox regression model). RESULTS: Forty-eight patients had severe associated medical conditions, and 26 patients were older than 69 years of age. Mortality was 3%, and morbidity was 68%. With a median follow-up of 52 months, median survival was 18 months. The overall 5-year survival was 23%, but it was 63% for early stages (pT1 + pT2). In the multivariate analysis, the risk of dying was increased by 4.9 (risk ratio) for patients with carcinomas invading beyond the muscularis propria (pT3 + pT4), compared to lower stages (pT1 + pT2) (P < 0.0001). To a lesser extent, longterm survival was also adversely affected by transfusions (packed erythrocytes) after controlling for stage (risk ratio 1.7; P = 0.047). Age (> 69 years), preoperative weight loss, tumor location, histology (adenocarcinoma versus squamous cell carcinoma), fresh frozen plasma, and splenectomy did not influence survival. CONCLUSION: In this study, transhiatal esophagectomy provided palliation for esophageal cancer with a low-perioperative mortality. Prolonged survival or cure was obtained for the majority of patients operated on in the early stages. Blood transfusions had a slight adverse effect on long-term survival.

The TRH-stimulation test in DSM-III personality disorder.

The authors examined thyrotropin-releasing hormone (TRH) stimulation testing in the neuroendocrine evaluation of DSM-III major depressive disorder in 26 consecutive medication-free, medically healthy patients meeting a primary DSM-III diagnosis of axis II personality disorder. Thyroid-stimulating hormone (TSH) responses to TRH challenge were not significantly different between patients with or without major depression at time of study, or between patients with or without a life history of major affective disorder. Further, TSH responses to TRH among 11 healthy male nonpsychiatric controls were not significantly different from those in patients with personality disorders. Comparison of those patients with blunted TSH responses (< 7.0 microU/ml) versus those without blunted response (< or = 7.0 microU/ml) also did not reveal a significant difference. In addition, the TSH response to TRH did not correlate with dimensional assessments of state or trait depression, anxiety, or with past history of suicide attempt or alcohol abuse. These data suggest that TRH stimulation testing has limited utility in the evaluation of major depression or other relevant affective states/traits in personality-disordered patients. Affective symptoms in personality-disordered patients do not seem to be associated with dysregulation of the hypothalamic-pituitary-thyroid axis.