Staging designation for bilateral Wilms' tumors.
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Humans↗
Biomedical subjects
D M Green
Publications and source records attributed to D M Green.
The number of components in profile analysis tasks.
The central issue of this paper is how detection of a change in spectral shape depends on the number of components m that define the spectrum. First, a channel theory is reviewed and the predictions relating the detectability of such a change as a function of the number of components are derived. Second, the existing literature is reviewed. Most of it concerns the detection of an increment in a single tone of an m-component, equal-amplitude complex. The data are close (+/- 2 dB) to the predictions of the theory, which suggests that there is a relatively small change in threshold as the number of components increases. The consistency of the data is also discussed and hypotheses for discrepancies are presented. Finally, the results of an experiment measuring the detectability of a special spectral shape change is explored. In this case, all the changes are equal in size but some are opposite in sign, so that the summed change is zero. The results using this "balanced" spectral change are also consistent with the predictions of the theory and show that for this special kind of spectral change thresholds improve by nearly 7 dB as m increases from 4 to 24 components.
Adult↗
On the similarity of two theories of comodulation masking release.
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Attention↗
Auditory intensity perception: successive versus simultaneous, across-channel discriminations.
This study measures the ability of observers to compare the intensities of two stimuli occupying different frequency regions. It includes three experiments, each experiment having two conditions. In one condition, the two stimuli to be compared were presented simultaneously within each interval; this condition has been called profile analysis. In the other condition, the two stimuli were presented successively within each interval. Because the overall level of the stimuli was randomized between intervals, the observers were encouraged to compare the intensities of the two stimuli within each observation interval rather than between intervals. The stimuli were two simple tones in experiment 1 and two tonal complexes in both experiments 2 and 3. The stimuli used in experiments 2 and 3 differed in frequency. The results show that simultaneous comparisons are superior to successive comparisons. For simple tones, the difference in threshold is about 8 dB; for complexes with 10 to 11 components, the difference in threshold is about 15 dB. These differences can be explained by assuming that internal noises in different channels were partially correlated when stimuli in those channels were presented simultaneously and were independent when the stimuli were presented successively. Cancellation of the correlated noise is therefore possible with simultaneous comparisons, making such discrimination better than that achievable with successive comparisons.
Acoustic Stimulation↗
Characterization of external ear impulse responses using Golay codes.
This report explains the use of a complementary series, Golay codes, for probing the impulse response of the external ear. The codes are used to measure both the resonance of the human ear canal, using a sealed sound-delivery system, and to measure the transfer function of the pinna, using a free-field source. With two series of 512 binary numbers, the improvement in signal-to-noise ratio over a single impulse approaches the theoretical value of 30.1 dB [10 log(2.512)]. This technique has many of the same properties as maximal-length sequences [M. R. Schroeder, J. Acoust. Soc. Am. 66, 497-500 (1979)], but it has the added advantage that the sequence length is an integer power of two and is, therefore, particularly convenient to use with modern Fourier transform techniques.
Ear Canal↗
Observations on a principal components analysis of head-related transfer functions.
A recent principal components analysis (Kistler and Wightman, 1992) has shown that the transfer functions of the human external ear, for a wide range of source locations, can be expressed as weighted sums of a small number of basis vectors. Directional transfer functions obtained in this laboratory, using substantially different measurement techniques, yielded principal component basis vectors that are remarkably similar to those reported by Kistler and Wightman. When this subject population was divided in half according to the overall physical sizes of subjects, basis vectors computed for the subpopulation of smaller subjects were shifted systematically to higher frequencies relative to those computed for the subpopulation of larger subjects.
Ear, External↗
Spectral shape discrimination of narrow-band sounds.
Measurements are reported on the detectability of signals added to narrow-band sounds. The narrow-band sounds had a bandwidth of 20 Hz and were either Gaussian noise with flat amplitude spectra or sets of equal-amplitude sinusoidal components whose phases were chosen at random. Four different kinds of sinusoidal signals were used. Two signals produced symmetric changes in the audio spectrum adding a component either at the center of the spectrum or at both ends. The other two signals produced asymmetric changes adding a component at either end of the spectrum. The overall level of the sound was randomly varied on each presentation, so that the presence of a signal was largely unrelated to the absolute level of the signal component(s). A model is proposed that assumes the detection of the symmetric signals is based on changes in the shape of the power spectrum of the envelope. Such changes in the envelope power spectrum are probably heard as changes in the "roughness" or "smoothness" of the narrow-band sound. The predictions of this model were obtained from computer simulations. For the asymmetric signals, the most probable detection cues were changes in the pitch of the narrow-band sound. Results from a variety of different experiments using three listeners support these conjectures.
Adult↗
Discrimination of narrow-band spectra. I: Spectral weights and pitch cues.
The ability to detect changes in the spectral shape of narrow-band tonal complexes (spectral profiles) is examined. The standard consists of three tones of equal intensity; thresholds for detecting an increment in the level of the central, 1000-Hz tone are estimated. A roving-level procedure is used in order to impose a statistical limit on thresholds that can be obtained by basing discriminations on absolute intensity. Estimated thresholds are consistently below this limit, thus indicating the use of other cues. Generally, thresholds are constant for bandwidths ranging from less than a critical band to greater than several octaves. Spectral weight estimates, however, are highly dependent on bandwidth, providing evidence that the discrimination of narrow-band spectra involves different auditory processes than those used to discriminate wideband spectra. Additional data show that pitch cues are important within a restricted range of intermediate bandwidth, but not for wideband or very narrow-band spectra. A version of the EWAIF model involving off-frequency listening is proposed to account for the results.
Adolescent↗
Prognostic factors in nonmetastatic, favorable histology Wilms' tumor. Results of the Third National Wilms' Tumor Study.
A comprehensive statistical analysis of relapses to lung and abdomen and of deaths due to tumor that occurred among 1466 patients with nonmetastatic, favorable histology (FH) Wilms' tumor entered on the Third National Wilms' Tumor Study (NWTS-3) was undertaken. In addition to lymph node involvement, age at diagnosis and tumor size as measured by the weight of the excised specimen were the most important determinants of outcome. The effects of tumor size were most apparent for patients with localized (Stage I) disease; age effects were found for patients with regional (Stage II or III) disease. The presence of microscopic tumor in the margin of surgical resection was an independent predictor of abdominal recurrence and death in the latter group. Although the report of the surgeon of diffuse soilage of the peritoneal cavity from tumor spilled or cut across in the course of nephrectomy was highly correlated with outcome, it was not possible to establish an independent prognostic role for such a finding after adjustment for the aforementioned factors. Patients with intralobar nephrogenic rests (ILNR) had a favorable survival outlook even after accounting for their generally younger ages and lower stages.
Abdominal Neoplasms↗
Congenital anomalies in children of patients who received chemotherapy for cancer in childhood and adolescence.
BACKGROUND: Many patients who have been treated successfully for childhood cancer with regimens that contain one or more mutagenic chemotherapeutic agents are concerned that their own treatment during childhood or adolescence may adversely affect their children. METHODS: To determine the effect of chemotherapy for cancer during childhood and adolescence on the outcome of subsequent pregnancies, we reviewed the records of 306 men and women who had been treated for pediatric cancer and who responded to our questionnaire. One hundred of the 306 patients reported 202 pregnancies. Among the patients who had received chemotherapy as part of their treatment for cancer, 60 patients or wives of patients had had one or more pregnancies of 20 or more weeks' gestation. The 60 former patients had a total of 100 live-born and 2 stillborn children. RESULTS: The frequency of congenital anomalies was 8.1 percent (5 of 62) among the live-born children of the women and 7.9 percent (3 of 38) among the live-born children of the men. Structural congenital cardiac defects were identified in 10.0 percent (2 of 20) of the children of women who had been treated with dactinomycin, as compared with 0.6 percent (144 of 24,153) among the children in a multicenter survey of fetal anomalies (P = 0.0126). We found no relation between the number of mutagens received or the cumulative dose of any agent received and the frequency of congenital anomalies in the children. CONCLUSIONS: These data suggest that treatment of children and adolescents with mutagenic chemotherapeutic agents, in the dose ranges we examined, does not increase the frequency of congenital anomalies in the children subsequently born to the former patients. However, the possible adverse effect of dactinomycin on the children of such patients requires further study.
Abnormalities, Drug-Induced↗
Achievement of life goals by adult survivors of modern treatment for childhood cancer.
To assess the impact of the diagnosis and modern treatment of childhood cancer on achievement of adult goals, the authors evaluated employment, health and life insurance coverage, marriage, divorce, and reproduction in 227 former pediatric cancer patients. Each area was evaluated in relation to a common set of disease and demographic factors that included age at follow-up, age at diagnosis, gender, marital status, history of disease recurrence, and diagnosis. Patients were younger than 20 years of age at diagnosis, and their diagnoses were made between January 1, 1960, and December 31, 1984. The median age at diagnosis was 11.4 years, and the median age at follow-up was 26.6 years. The percentage of unemployed male respondents did not differ from population norms. The percentage of unemployed female respondents, however, was slightly higher than that of the United States population. Approximately 11% of the survivors reported some form of employment-related discrimination, a level significantly lower than that of prior reports. Company-offered health insurance was provided to 92.4% of full-time and 90.0% of part-time employed respondents. Life insurance was purchased by 60% of full-time employed men and 55% of women. These percentages were lower than those reported for the United States population. Twenty-four percent of those with life insurance had difficulty obtaining it. Fifty-eight percent of the subjects were married or lived as married. The percentages of married men and women were significantly lower than United States norms. Twenty percent of those who were married or lived as married have divorced or separated or no longer live as married. Women aged 20 to 24 years were less likely to marry, and women aged 35 to 44 years had a significantly higher frequency of divorce than similarly aged United States women. In general, the history of childhood cancer did not influence the decision to marry or live as married but was occasionally (20%) important in the decision to dissolve a marital relationship. Many former patients indicated that their diagnosis and treatment for childhood cancer influenced their decision to have children. The current study suggests that most former pediatric cancer patients achieve adult life goals. Additional research is necessary to define those populations at greatest risk of failure to achieve these goals.
Adolescent↗
Constitutional extra chromosomal element in a family with Wilms' tumor.
We report the presence of an extra chromosomal element in a family with Wilms' tumor (WT). This family has three children, two of whom were affected. One son, the proband, had bilateral and one daughter had unilateral WT. The first child, the father, and the mother did not have WT. The son with bilateral WT had a ring chromosome (R) both in the lymphocytes as well as in the kidney tissue. The size of the ring varied considerably from cell to cell. The daughter with unilateral WT had an abnormal clone containing a small chromosomal ring (r) in phytohemagglutinin (PHA)-stimulated and Epstein-Barr virus (EBV)-transformed lymphocytes. The mother had a karyotype similar to that of the daughter with WT. We hypothesize that the proband's ring chromosome could be the amplified form of the r inherited from the mother. Chromosome 11 was cytogenetically normal in all the cells examined of the affected children and the unaffected mother. In situ hybridization with a centromere-specific DNA cocktail indicated dispersed centromeric DNA both in r and R.
Adult↗
The role of surgical excision in the management of relapsed Wilms' tumor patients with pulmonary metastases: a report from the National Wilms' Tumor Study.
To determine the effect of surgical excision of pulmonary metastases from Wilms' tumor on postrelapse survival, we retrospectively analyzed the clinical courses of 211 patients with stages I to III, favorable or unfavorable histology Wilms' tumor entered on National Wilms' Tumor Study-1, -2, or -3 whose first recurrence was limited to the lungs. There was no difference in the 4-year postrelapse survival percentage of favorable-histology patients with a solitary pulmonary metastasis who did or did not undergo surgical removal of the metastasis in addition to pulmonary irradiation and chemotherapy. Although histological confirmation of pulmonary relapse is frequently indicated, the present data suggest that therapeutic removal of pulmonary metastases from patients with relapsed Wilms' tumor does not increase the percentage of patients who survive for 4 years postrelapse, compared with treatment with whole-lung irradiation and chemotherapy.
Child↗
Extended followup of bilateral Wilms tumor: results of the National Wilms Tumor Study.
The long-term survival of patients with synchronous bilateral Wilms tumor is not well defined. Retrospective review of 185 patients registered with the National Wilms Tumor Study from January 1974 to July 1986 with stage V tumors suggests that the long-term outcome remains good. Over-all survival is 83%, 73% and 70% at 2, 5 and 10 years, respectively. Unfavorable histology, age at diagnosis and the most advanced stage of the individual tumors remain the most important prognostic variables. No significant difference in survival was noted between patients undergoing initial surgical resection of the tumor and those managed with initial tumor biopsy followed by chemotherapy with or without radiotherapy and subsequent surgical resection. Survival does not appear to be compromised by attempting to conserve native renal function with renal-sparing operations.
Age Factors↗
Remaining problems in the treatment of patients with Wilms' tumor.
Major advances have been made in the treatment of children with Wilms' tumor. Remaining areas of investigation include the role of adriamycin and the treatment of children with stage III and IV disease and the role of whole lung radiation therapy in the treatment of children with pulmonary metastases. Long-term follow up of successfully treated patients will provide valuable insight into the importance of genetic factors in the cause of Wilms' tumor.
Antineoplastic Combined Chemotherapy Protocols↗
Spectral weights and the profile bowl.
In these experiments, listeners detected changes in the shape of a complex spectrum that varied in overall level. With multicomponent complexes, a typical finding is that the listeners were more sensitive to changes made in the middle components of the spectrum than to changes made at either edge. We used a technique developed by Berg (1989) to estimate the weight listeners attached to the different components of the spectrum in making these judgements. For reasons not understood, the pattern of spectral weights was nearly optimum for a change made in the middle component of the spectrum and much poorer when the change occurred at either edge.
Attention↗
The detection of a tone added to a narrow band of noise: the energy model revisited.
In an effort to determine whether cues related to changes in energy contribute to the detection of a tone added to a narrow band of noise, we examined the effect of level variation on detection thresholds. In the first experiment, the level of each waveform was randomly varied on each presentation. Level variation had only marginal effects on performance. In addition, detection thresholds were obtained using bands of noise with equal energy across intervals. Neither increasing nor decreasing the variance of the noise-alone and tone-plus-noise energy difference distributions altered the detectability of a tone added to noise. Thus, the changes in energy that are concomitant with the addition of the tone are not the sole cue for the detection of the tone. In a second experiment, three psychometric functions were measured. One function was determined using no level variation, one was measured in the presence of level variation, and one was measured in the context of level variation, but for trials without level variation. The context of level variation slightly reduced detectability. In a third experiment, we compared detectability in three conditions: no level variation, across-trial level variation, and across-interval level variation. The thresholds obtained in the absence of level variation were superior to those measured in the presence of level variation, regardless of the manner in which the level variation was incorporated.
Attention↗
Effect of amplitude modulation on profile detection.
The effect of amplitude modulation on profile detection was examined in three experiments. The observer's task was to determine in which observation interval an increment was added to the 1000-Hz target component of a multitone complex in which the components were equally spaced on a logarithmic frequency scale from 200 to 5000 Hz. The target was unmodulated throughout the study. In some conditions, all nontarget components of the standard were modulated in phase; in other conditions, they were modulated with random phase. In experiment 1, the threshold was measured as a function of the modulation rate. The results show that, at low modulation rates, 5 Hz for example, modulation elevates threshold by about 13 dB. The threshold decreases as the modulation rate increases, with the threshold elevation being only 3 dB at 80 Hz. In experiment 2, threshold was measured as a function of modulation depth for both 21- and 5-component complexes. The results show that for a 5-Hz modulation rate the threshold decreases as the modulation depth decreases, and that the rate of decrease is greater for the 21-component complex than for the 5-component complex. In experiment 3, the effects of random-phase modulation were explored; the phase of the modulation waveform was randomly chosen for each component. The results show that there is no difference between in-phase and random-phase modulation when each component occupies a different critical band. If, however, two or more components occupy the same critical band, then randomizing the phase of modulation reduces the effective depth of modulation within that critical band, and the effect of modulation is thereby lessened.
Adult↗