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  • 1
    ISSN: 1432-0991
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Legionella pneumophila isolated in guinea pigs from human lung tissues was highly virulent as determined by its infectivity and lethality in guinea pigs. Repeated passages of the bacteria on agar media resulted in the loss of virulence in guinea pigs. Virulence, however, was restored by cultivating the avirulent bacteria in cell cultures of human embryonic lung fibroblasts. Death of the host animals was the result of infection; no lethal toxin was detected in the cultural filtrate. These findings indicate that the virulent form ofL. pneumophilia is capable of surviving inside the host cells either through its endogenous resistance to environmental factors within the host cells or by host cell selection. Intracellular multiplication of the virulent bacteria followed by destruction of host cells appears to be an important pathogenic mechanism of Legionnaires' disease.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Metrika 29 (1982), S. 203-209 
    ISSN: 1435-926X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Summary A procedure is proposed in this paper for testing the shape parameter, β of the Weibull distribution. The test statistic which is based on the extremal quotient, possesses a monotone property which makes it possible for rejection earlier than the last planned observation of the null hypothesis,H 0: β=β0 when the alternative hypothesis isH a: β〈β0 and early acceptance ofH 0 whenH a: β〉β0. The test being scale-free, does not require the scale parameter to be known.
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  • 3
    ISSN: 1432-1041
    Keywords: probucol ; hypercholesterolemia ; cardiotoxicity ; electrocardiograms ; arterisclerosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Probucol is known to prolong QT intervals in some patients and to produce fatal arrhythmias in selected animal species. To assess the prevalence and clinical relevance of this effect in a controlled manner, we analyzed electrocardiograms (ECGs) and medical events in patients during a placebo-controlled crossover trial comparing single or combined administration of probucol and colestipol. Forty-two Type II hyperlipoproteinemic patients were studied for eighteen to twenty-four months. Two cardiologists independently read the tracings which were previously arranged randomly without names or dates. There were no statistical differences between the reports of the ECG parameters by the two cardiologists. The mean QTc interval of the entire patient population was lengthened after probucol administration without reaching statistical significance when compared to placebos or colestipol treatments. Forty-eight % of the patients showed lengthening of the QTc interval during probucol treatment by 11 to 70 msec increment over baseline placebo. The remaining had either no change or shortening of the interval. There were no statistically significant differences in means of R-R, PR, QRS, QTc or QoT intervals among placebo, probucol., colestipol and probucol plus colestipol treatments. It is concluded that probucol prolonged QT intervals in the electrocardiograms of about one half of patients receiving the drug with no other clinical or statistically significant evidence of cardiotoxicity or electrocardiographic effects.
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  • 4
    ISSN: 1432-0770
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Computer Science , Physics
    Notes: Abstract The firing time of a cable model neuron in response to white noise current injection is investigated with various methods. The Fourier decomposition of the depolarization leads to partial differential equations for the moments of the firing time. These are solved by perturbation and numerical methods, and the results obtained are in excellent agreement with those obtained by Monte Carlo simulation. The convergence of the random Fourier series is found to be very slow for small times so that when the firing time is small it is more efficient to simulate the solution of the stochastic cable equation directly using the two different representations of the Green's function, one which converges rapidly for small times and the other which converges rapidly for large times. The shape of the interspike interval density is found to depend strongly on input position. The various shapes obtained for different input positions resemble those for real neurons. The coefficient of variation of the interspike interval decreases monotonically as the distance between the input and trigger zone increases. A diffusion approximation for a nerve cell receiving Poisson input is considered and input/output frequency relations obtained for different input sites. The cases of multiple trigger zones and multiple input sites are briefly discussed.
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  • 5
    ISSN: 1432-0800
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
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  • 6
    ISSN: 1432-1106
    Keywords: Tectum ; Pigeon ; Directionally specific cells-background movement ; Opponent processes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The experiments reported in this paper were carried out to determine the effect moving background patterns have on the response characteristics of directionally specific neurons in the pigeon optic tectum. First, care was taken to select the optimal single stimulus for each cell, then large textured patterns were added to the test stimulus and moved either ‘in-phase’ or ‘anti-phase’. Altogether 214 cells were studied in 77 white Carneaux pigeons and it was found that all cells below a depth of 400 microns were inhibited by backgrounds moved ‘in-phase’ with the optimal test stimulus, while few cells above this level were affected in any way by backgrounds. All directions of background motion containing an ‘in-phase’ vector resulted in rather profound inhibition of the directional response while directions with an ‘anti-phase’ vector produced less inhibition and sometimes were even facilitated by direct ‘anti-phase’. The velocity tuning curves obtained with an optimal single test stimulus and by ‘anti-phase’ movement of backgrounds were essentially similar. ‘In-phase’ inhibition can also be produced by a second spot stimulus located some distance from the test stimulus. This latter effect was used to map the outer margins of the inhibitory receptive fields of deep tectal neurons displaying these effects and it was found they were extremely large, often in excess of 100 ° in diameter. When masks were used to prevent the moving background from stimulating the excitatory receptive field, ‘anti-phase’ movement always produced facilitation. This suggests a double opponent-process directionally specific receptive field organization. These neurons seem well suited to respond to local (object) motion and to ignore translation of the visual image arising from body, head and eye movements.
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    World journal of surgery 6 (1982), S. 66-75 
    ISSN: 1432-2323
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé De 1964 à 1981, 165 malades porteurs d'un cancer primitif du foie ont subi types d'exéréses hépatiques. Dans 85% des cas le cancer sétait développé sur un foie cirrhotique. Dans 78.4% le H.B. s Ag a été constaté cependant que dans 85.7% de cas le dosage de l'alpha protéine sérique était positif. Le taux des complications fut élevé: 42.1% ainsi que celui de la mortalité: 20%. L'intervention la plus fréquente fut l'hémi-hépatectomie droite: 42.4% des cas cependant que le taux de l'hémi-hépatectomie gauche était de 34.5%. Vingt-deux opérés (13.3%) subirent une hépatectomie dextro-médiane. La survie la plus longue (un patient opéré en 1962) fut de 20 ans cependant que le taux actuariel de survie atteint 20%.
    Notes: Abstract From 1964 to 1981, a total of 165 patients with primary carcinoma of the liver underwent various types of hepatic resections. Eighty-five percent of tumors were found in cirrhotic livers. In 78.4%, HBsAg could be demonstrated by the reverse passive hemagglutination technique, while 85.7% had positive alpha-fetoprotein in the serum. The complication rate was high (42.1%), while the hospital death rate was 20%. The most frequent operations were a right hemihepatectomy (42.4%) and a left hemihepatectomy (34.5%), while 22 patients (13.3%) underwent extended right hepatectomy. The longest survival (a patient operated on in 1962) is now 20 years, and the 5-year survival rate, as shown in the actuarial survival curve, is 20%.
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  • 8
    ISSN: 1432-2323
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé La relation entre les variations du taux de l'antigène carcino-embryonnaire et les divers types de récidive ont été étudiés chez 146 sujets qui avaient subi une opération à visée curative pour cancer du colon ou du rectum. La récidive s'est manifestée chez 51 opérés (34,9%), locale dans 24 cas, à distance dans 23 cas, locale et à distance dans 14 cas. La pente des valeurs de l'antigène fut calculée pour chaque sujet dès que le taux de l'antigène atteignait 1 ng/ml et exprimée en pourcentage d'élévation de l'antigène pour chaque mois. Les opérés qui récidivèrent présentèrent des pentes plus élevées que ceux qui furent exempts de récidive (médiane de 20,0% VS 0,3% d'élévation,p 〈0,001). Une élévation de la pente de 5% par mois séparaient les deux groupes avec un taux de précision de 79,4%, de sensibilité de 86,3%, de spécificité de 75,8%. Les valeurs moyennes de la ligne de pente de l'antigène n'ont pas présenté une différence significative selon les divers types de récidive. Cependant par comparaison avec les opérés indemnes de récidive, la plupart des sujets atteints de récidive locale présentaient une ligne de pente inférieure à une élévation de 5% par mois (8,1% VS 28,6%, respectivement), encore que chez 10 opérés sur un groupe de 14, une ligne de pente supérieure à 5% par mois ait été observée. On peut conclure de cette étude que le dosage régulier de l'antigène carcino-embryonnaire est utile pour dépister les récidives locales ou à distance. De plus, la constitution d'une ligne de pente renforce la sensibilité de la méthode de dépistage.
    Abstract: Resumen La relación entre el patrón de alteración del antígeno carcinoembriónico (ACE) y los diferentes tipos de recurrencia fue investigada mediante un estudio prospectivo de 146 pacientes sometidos a operaciones curativas por adenocarcinoma de colon o del recto. Se presentaron recurrencias en 51 pacientes (34,9%), y éstas fueron de tipo local en 14, distal en 23 y local y distal en 14 de ellos. Los valores de inclinación de los niveles de ACE sérico en determinaciones postoperatorias seriadas fueron calculados individualmente para cada paciente, comenzando cuando se presentó una elevación de más de 1 ng/ml, y expresados como % de la elevación del ACE por mes. Los pacientes con relapso presentaron inclinaciones significativamente mayores que los pacientes que se mantuvieron libres de enfermedad (la media fue 20,0% vs elevación del 0,3%,p〈0,001). Un valor de inclinación del 5% de aumento por mes separa en forma amplia los dos grupos, con una tasa global de seguridad de 79,4%, una tasa de sensibilidad para recurrencia de 86,3% y una tasa de especificidad de no relapso de 75,8%. Las inclinaciones medias del nivel de ACE no difirieron significativamente en el grupo de pacientes con diferentes tipos de relapso. Sin embargo, al compararlos con los pacientes que exhibían alguna recurrencia distal, se encontró que más pacientes con recurrencia local tenían inclinaciones de menos del 5% de aumento por mes (8,1% vs 28,6%, respectivamente,p de un solo final = 0,04). No obstante, una inclinación en exceso de 5% de aumento por mes fue observada en 10 de los 14 pacientes con recurrencia local. Hemos llegado a la conclusión de que la monitoría postoperatoria seriada del ACE es de utilidad en la detección de las recurrencias tanto locales como distales. Además, el uso del análisis de la inclinación puede acrecentar la sensibilidad de la monitoria postoperatoria del ACE como medio de detección del relapso.
    Notes: Abstract The relationship between the pattern of carcinoembryonic antigen (CEA) changes and the types of recurrence was investigated in a prospective study of 146 patients who underwent curative operations for adenocarcinoma of the colon or rectum. Recurrences developed in 51 patients (34.9%) and was local in 14, distant in 23, and both local and distant in 14 of them. CEA slope values were individually calculated beginning with an initial rise of more than 1 ng/ml, and expressed as the % rise in CEA per month. Patients who relapsed had significantly higher slopes than those who remained well (median 20.0% versus 0.3% rise,p〈0.001). A slope value of 5% rise per month broadly separated the two groups with an overall accuracy of 79.4%, sensitivity rate for recurrence of 86.3%, and specificity rate for no relapse of 75.8%. Median CEA slope values did not differ significantly among patients with different types of relapse. However, compared with patients who had any distant recurrence, more patients with localized recurrence had slope values of less than 5% rise per month (8.1% versus 28.6%, respectively; one-tailed p=0.04). Nevertheless, a slope exceeding a 5% rise per month was observed in 10 of the 14 patients with local recurrence. We conclude that serial postoperative CEA monitoring is useful in detecting both local as well as distant recurrence. Furthermore, the use of slope analysis may enhance the sensitivity of postoperative CEA monitoring for detecting relapse.
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  • 9
    ISSN: 1432-2323
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé Pour évaluer les mérites respectifs de la biopsie aspiration à l'aiguille et de la biopsie à l'aiguille tranchante, les auteurs ont procédé à une étude prospective contrôlée chez 384 sujets qui présentaient des nodules thyroïdiens. La première méthode permet plus de précision dans le diagnostic et présente moins de complications que la seconde. Le diagnostic porté grâce aux biopsies a été confirmé dans 41,1% des cas. Les deux méthodes atteignent un très haut degré d'exactitude et les faux positifs concernant les lésions autres que folliculaires n'ont été constatés que dans les lésions considérées comme potentiellement malignes. Cependant, aucune des deux méthodes ne permet la distinction entre tumeur folliculaire bénigne et maligne. Les tumeurs folliculaires susceptibles d'être malignes étant incluses, le taux de sensibilité a été de 86,5% pour la première méthode et de 91,90% pour la seconde. L'association des deux méthodes de biopsie a permis de porter le diagnostic exact dans 97,3% des 37 cas de tumeurs malignes. Plutôt que de démontrer la supériorité d'une méthode par rapport à l'autre, cette étude confirme la valeur de l'association des deux types de biopsie. En combinaison avec les données de la clinique et les données des explorations morphologiques, la biopsie à l'aiguille réduit le nombre des interventions inutiles, sans pour autant comporter le risque de laisser en place des cancers de la thyroïde.
    Abstract: Resumen Con el propósito de evaluar los méritos relativos de la aspiración con aguja fina (AAF) y de la biopsia Tru-cut (BTC), establecimos un ensayo prospectivo controlado en 384 pacientes con nódulos tiroideos dominantes. La AAF exhibió un mejor rendimiento diagnóstico y menos complicaciones que la BTC. La confirmación definitiva del diagnóstico por biopsia fué obtenida en el 41,1% de los pacientes. Ambas técnicas lograron un muy elevado grado de certeza, y los errores positivos falsos ocurrieron sólo en lesiones no foliculares en casos señalados como posiblemente malignos. Sin embargo, ninguno de los dos métodos pudo distinguir en forma confiable la neoplasia folicular benigna de la maligna. Incluyendo las neoplasias foliculares como sospechosas de malignidad, las tasas de sensibilidad individual para cáncer fueron de 86,5% para AAF y de 91,9% para BTC. Sin embargo, el uso combinado de AAF y BTC pudo detectar el 97,3% de 37 tumores malignos. En vez de demostrar una ventaja abrumadora para ninguno de los métodos, este estudio da apoyo al uso tanto de la AAF como de la BTC en la investigacíon de nódulos tiroideos. Cuando se combina con la información clínica y con los procedimientos imagenológicos, la biopsia percutánea con aguja (AAF y la BTC) reduce el número de operaciones innecesarias sin comprometer la necesidad de resección de los cánceres tiroideos.
    Notes: Abstract In order to evaluate the relative merits of fine-needle aspiration (FNA) and Tru-cut® needle biopsy (TNB), we conducted a prospective controlled trial in 384 patients who had dominant thyroid nodules. FNA had a slightly higher diagnostic yield and fewer complications than TNB. Definitive confirmation of the biopsy diagnoses was obtained in 41.1% of the patients. Both techniques achieved a very high degree of overall accuracy, and false-positive errors among non-follicular lesions occurred only in cases labeled as possibly malignant. However, neither method could reliably distinguish between a benign and malignant follicular neoplasm. Including follicular neoplasms as suspicious for malignancy, the individual sensitivity rates for cancer were 86.5% and 91.9% for FNA and TNB, respectively. The combined use of FNA and TNB, however, detected 97.3% of the 37 malignancies. Rather than demonstrating any overwhelming relative advantage, this study would support the use of both FNA and TNB to investigate dominant nodules. When combined with clinical information and imaging studies, needle biopsy can reduce the number of unnecessary operations without seriously compromising the removal of thyroid cancers.
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  • 10
    ISSN: 1432-2323
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé Nous avons, au cours des 14 dernières années, réalisé une pharyngo-laryngo-oesophagectomie avec anastomose pharyngo-gastrique chez 157 malades; 67 cancers de l'hypopharynx, 7 cancers de l'oesophage cervical et 83 cancers du larynx envahissant l'hypopharynx. La technique opératoire utilisée est celle qui a été décrite par ONG en 1960 et modifiée en 1971. La mortalité hospitaliére globale a été de 31%; pour les deux dernières années, elle a été réduite à 18%. La mortalité est plus élevée chez les malades dont l'état cardiopulmonaire est précaire et dans les cas où la tumeur, étendue jusqu'à la base de la langue, exigeait la résection du 1/3 postérieur de celle-ci. La radiothérapie préopératoire augmente le risque de lachage des anastomoses. Pour améliorer les résultats postopératoires précoces, il faut que l'estomac soit sain et bien préparé, que l'anastomose soit réalisée dans des conditions parfaites, que les vaisseaux vulnérables soient protégés. La récupération fonctionnelle est bonne pour la déglutition, mais pauvre pour la parole. La survie à 5 ans est de 17.8%. Notre plus longue survie est de 10 années après l'opération initiale. Les métastases sont la cause la plus fréquente d'échecs à long terme. Pour améliorer la survie, il faudra peut-Être compléter la chirurgie par des thérapeutiques adjuvantes.
    Notes: Abstract During the last 14 years, pharyngogastric anastomosis following pharyngolaryngoesophagectomy was performed in 157 patients, among whom 67 had carcinoma of the hypopharynx, 7 had carcinoma of the cervical esophagus, and 83 had carcinoma of the larynx involving the hypopharynx. The operative procedure was that described previously by Ong in 1960, and modified in 1971. The overall hospital mortality was 31%, which in the last 2 years of the study had fallen to 18%. It was found that the mortality was higher in patients with poor cardiopulmonary status and in patients whose tumors had extended into the vallecula, thus requiring resection of the posterior third of the tongue. Previous failed radiotherapy increased the risk of leakage of the anastomosis. The immediate results of the operation can be improved if the surgeon ensures that a healthy stomach is prepared, a secure anastomosis is performed, and the vulnerable blood vessels are protected. Postoperative function in terms of swallowing ability was good, but rehabilitation of speech was poor. The 5-year survival rate was 17.8%. The longest surviving patient is still alive 10 years after the original operation. The most common cause of long-term failure was the development of metastatic disease. Improvement in survival results may require the use of adjuvant therapy to operative treatment.
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