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Biomedical subjects

J R Anderson

Publications and source records attributed to J R Anderson.

At least 127 records · Page 7Linked to original sources
PubMed1997

Pointing, withholding information, and deception in capuchin monkeys (Cebus apella).

Brown capuchin monkeys, like 4-year-old children and human-socialized chimpanzees, showed communicative and deceptive pointing in experiments in which they benefited by indicating, accurately or falsely, the location of hidden food. All 3 capuchin monkeys tested (13, 19, and 26 years old) pointed communicatively in the presence of a cooperative trainer. One human-reared monkey pointed without any training and frequently gazed at her human respondent; as with apes, extensive exposure to humans may promote some human-like responses in monkeys. Another capuchin withheld pointing when beneficial, whereas the 3rd learned to obtain the hidden food by pointing deceptively in the presence of a competitive trainer. Such deceptive pointing by one monkey and withholding of information by another suggest that primates' deceptive pointing in an experimental situation is explainable in terms of response inhibition and conditional discrimination learning.

Animals↗
PubMed1997

A second dose of a CFTR cDNA-liposome complex is as effective as the first dose in restoring cAMP-dependent chloride secretion to null CF mice trachea.

Phase I clinical trials have provided encouraging data suggesting that gene transfer could provide a treatment for cystic fibrosis (CF). However, for all the current viral and nonviral vectors used to deliver the cystic fibrosis transmembrane conductance regulator (CFTR) gene, the duration of CFTR expression is limited, necessitating a repeat dosing regimen to provide a long-term treatment. This study was performed to determine whether a second delivery of a CFTR cDNA-liposome complex could result in a similar level of functional CFTR expression observed after a single delivery and to assess whether the deliveries produced adverse inflammatory responses. CFTR functional expression was assessed by short circuit current measurements of tracheas taken from CF null mice (Cftrtm1Cam) treated with a CFTR cDNA-liposome complex in the upper airways. Mice receiving two deliveries of this complex, the second after the response to the first had declined, showed cAMP-stimulated chloride currents which were not significantly different from normal tracheas or tissues assayed after a single dose of the complex. This double treatment was well tolerated with no discernible inflammation of lung tissue.

Animals↗
PubMed1997

Preschoolers' perception of other people's looking: photographs and drawings.

Children aged 3-4 years were tested for their ability to decide which of two photographs or drawings of a face depicted the act of fixating on a target object; in each control photograph or drawing the same face and object were present without fixation. Performance was above chance on both stimulus types, but low enough to call into question conclusions from previous research. The same children were also tested on their ability to discriminate between photographs/drawings depicting two faces fixating the same object (joint visual attention) and the same two faces fixating different objects. While discrimination of joint visual attention depicted in drawings was as good as discrimination of fixation in the single-face tasks, the ability to reliably choose between a photograph of two people attending to a common object and a control photograph was significantly poorer. The results suggest that, while young infants and children may be highly sensitive to face-on gaze, even well into the fourth year of life children are unable consistently to interpret (1) direction of non-self-directed gaze in static faces and (2) joint visual attention by others.

Art↗
PubMed1997

High-dose therapy with autologous hematopoietic rescue for follicular low-grade non-Hodgkin's lymphoma.

PURPOSE: This study evaluated the results of high-dose therapy followed by autologous bone marrow or peripheral-blood stem-cell transplantation for patients with follicular low-grade non-Hodgkin's lymphoma. PATIENTS AND METHODS: We performed a retrospective review of 100 patients undergoing autologous transplantation for follicular low-grade lymphoma between April 22, 1983 and December 31, 1993. RESULTS: Sixty-seven patients remained alive and 48 were failure-free. The median follow-up duration of surviving patients was 2.6 years (range, 1.0 to 11.7). There were eight (8%) deaths within 100 days of transplantation. Six additional patients died of nonrelapse causes up to 912 days after transplantation. Overall survival at 4 years was estimated to be 65% (95% confidence interval [CI], 54% to 75%) and failure-free survival was estimated to be 44% (95% CI, 33% to 55%). There was no definite evidence of a plateau in the failure-free survival curve. The only factor significantly associated with overall survival and failure-free survival was the number of chemotherapy regimen received before transplantation. No significant differences in outcome were observed between patients with follicular small cleaved-cell lymphoma and follicular mixed lymphoma, or between patients who received peripheral-blood stem-cell transplants and unpurged autologous bone marrow transplants. CONCLUSION: Prolonged failure-free survival is possible following high-dose therapy and autologous hematopoietic rescue for follicular low-grade lymphoma. It is unclear whether patients are cured with this therapy or if survival is prolonged.

Adult↗
PubMed1997

Ewing's sarcoma of soft tissues in childhood: a report from the Intergroup Rhabdomyosarcoma Study, 1972 to 1991.

PURPOSE: One hundred thirty of 2,792 patients (5%) registered on three Intergroup Rhabdomyosarcoma Study clinical trials (IRS-I, -II, and -III) from 1972 to 1991 had an extraosseous Ewing's sarcoma (EOE). We report here the results of multimodality therapy for this tumor. PATIENTS AND METHODS: The 130 patients were less than 21 years of age; 70 (54%) were males. Primary tumor sites were on the trunk in 41 patients, an extremity in 34, the head/neck in 23, the retroperitoneum/pelvis in 21, and other sites in 11. One hundred fourteen patients had no metastases at diagnosis. In 21 patients, the tumor was completely resected; in 30, the localized or regional tumor was grossly resected, and in 63 patients, grossly visible sarcoma was left behind. Sixteen patients (12%) had distant metastases at diagnosis. All patients were given multiagent chemotherapy and most received irradiation (XRT); none were treated with bone marrow transplantation. RESULTS: One hundred seven patients (82%) achieved a complete response. At 10 years, 62%, 61%, and 77% of the patients were alive after treatment on IRS-I, IRS-II, or IRS-III therapeutic protocols, respectively, similar to figures obtained in all IRS patients. At last follow-up evaluation, 42 patients had died of progressive tumor and one of infection. Survival at 10 years was most likely for patients with tumor that arose in the head and neck, extremities, and trunk, and for those who underwent grossly complete tumor removal before initiation of chemotherapy. For patients with localized, gross residual tumor, adding doxorubicin (DOX) to the combination of vincristine, dactinomycin, cyclophosphamide (VAC), and XRT did not significantly improve survival in 39 patients (62% alive at 10 years) compared with that of 24 patients treated with VAC and XRT without DOX (65% alive at 10 years, P = .93). CONCLUSION: This series indicated that EOE in children is similar to rhabdomyosarcoma (RMS) in its response to multimodal treatment. No benefit was apparent from the addition of DOX to VAC chemotherapy in patients with gross residual EOE.

Adolescent↗
PubMed1997

Allogeneic-blood stem-cell collection following mobilization with low-dose granulocyte colony-stimulating factor.

PURPOSE: The optimal dose of granulocyte colony-stimulating factor (G-CSF) for mobilization of allogeneic-blood stem cells (AlloBSC) has yet to be determined. As part of a prospective trial, 41 related human leukocyte antigen (HLA)-matched donors had blood cells mobilized with G-CSF at 5 micrograms/kg/d by subcutaneous administration. The purpose of this trial was to monitor adverse effects during G-CSF administration and stem-cell collection, to determine the optimal timing for stem-cell collection, and to determine the cellular composition of stem-cell products following G-CSF administration. PATIENTS AND METHODS: The median donor age was 42 years. Apheresis began on day 4 of G-CSF administration. At least three daily 12-L apheresis collections were performed on each donor. A minimum of 1.0 x 10(6) CD34+ cells/kg (recipient weight) and 8.0 x 10(8) mononuclear cells/kg were collected from each donor. All collections were cryopreserved in 5% dimethyl sulfoxide and 6% hydroxyethyl starch. RESULTS: Toxicities associated with G-CSF administration and the apheresis process included myalgias/arthralgias (83%), headache (44%), fever (27%), and chills (22%). The median baseline platelet count of 242 x 10(4)/ mL decreased to 221, 155, and 119 x 10(6)/mL on days 4, 5, and 6 of G-CSF administration, respectively. Median numbers of CD34+ cells in collections 1, 2, and 3 were 1.99, 2.52, and 3.13 x 10(6)/kg, respectively. The percentage and total number of CD4+, CD8+, and CD56+/CD3- cells remained relatively constant during the three collections. Median total numbers of cells were as follows: CD34+, 7.73 x 10(6)/kg; and lymphocytes, 6.93 x 10(8)/kg. CONCLUSION: Relatively low doses of G-CSF can mobilize sufficient numbers of AlloBSC safely and efficiently.

Adult↗
PubMed1997

The combination of laser recanalization and endoluminal intubation in the palliation of malignant dysphagia.

Laser recanalization and endoluminal intubation have been combined to optimize the palliation of malignant dysphagia in 37 patients. Nine patients with an endoluminal tube in situ presented with secondary dysphagia due to tumour overgrowth. Patency of the prosthesis was restored in all patients by laser recanalization with no complications. Twenty-eight patients treated initially by laser recanalization required subsequent intubation. The indications were dysphagia secondary to external compression (n = 3), significant angulation (n = 9), tracheo-oesophageal fistula (n = 3), failure of laser recanalization (n = 8), poor palliation (n = 3) or a combination of these (n = 2). There were no complications associated with the insertion of the tube and all patients subsequently reported improved swallowing. Laser recanalization or endoluminal intubation in isolation provide adequate palliation in the majority of patients with malignant dysphagia. We have shown that the appropriate timed combination of these two modalities may optimize the palliation of dysphagia in patients in whom the primary treatment modality fails.

Adult↗
PubMed1996

p53 mutations in mantle cell lymphoma are associated with variant cytology and predict a poor prognosis.

Mutations of the p53 tumor suppressor gene have been described in several subtypes of non-Hodgkin's lymphoma, but the incidence of p53 mutations in mantle cell lymphoma (MCL) is unknown. We hypothesized that cases of MCL with a variant or high-grade cytology would have a higher likelihood of p53 mutations than typical MCL. We were also interested in the prognostic significance of p53 mutations in MCL. Therefore, a series of 53 well-characterized cases of MCL with DNA from 62 tissue samples were analyzed by the polymerase chain reaction with denaturing gradient gel electrophoresis for exons 5-8 of p53. Immunoperoxidase studies with the antibody DO-7 to p53 protein were also performed on frozen sections. We found mutations of the p53 gene in 8 of the 53 cases (15%) of MCL. Missense mutations predominated, and 50% of the mutations occurred at known p53 hotspot codons. Of 21 cases with variant cytology (ie, anaplastic or blastic), 6 (28.6%) had p53 mutations as compared with only 2 of 32 cases (6.3%) with typical MCL cytology (P = .05), and p53 mutations preceded the development of variant cytology in 2 patients. Overexpression of p53 protein was observed in 6 of the 8 cases (75%) with p53 mutations and in none of the 45 wild-type cases. The median survival of the cases with mutant p53 was only 1.3 years (all died), whereas the median survival of cases with germline p53 was 5.1 years (P = .023). These results suggest that mutations of p53 may be one mechanism involved in the development of variant forms of MCL and indicate that p53 mutations in MCL predict a poor prognosis.

Base Sequence↗
PubMed1996

Occurrence of the t(2;5)(p23;q35) in non-Hodgkin's lymphoma.

Primary CD30(Ki-1)-positive anaplastic large-cell lymphoma (ALCL) is considered by some to be a distinct clinicopathologic entity associated with the t(2;5) (p23;q35). However, the specificity of t(2;5) for ALCL has not been carefully studied. Therefore, we performed a detailed analysis of all cases of ALCL with abnormal cytogenetics results in the Nebraska Lymphoma Study Group registry, as well as all other cases of non-Hodgkin's lymphoma with t(2;5) in the registry. We found the t(2;5) in only five of 10 cases of ALCL, four of whom were young patients. However, we also found the t(2;5) in 11 other cases of nonanaplastic lymphoma, including eight children with typical peripheral T-cell lymphomas of various types. The t(2;5) was also found in three older adults with B-cell lymphomas of various types. Thus, the t(2;5) was not specific for CD30+ ALCL. However, t(2;5) may define a clinicopathologic entity in children and young adults characterized by variable morphologies with a T-cell or indeterminate phenotype, CD30-positivity, nodal disease with frequent extranodal involvement, advanced stage, and an excellent response to therapy, including bone marrow transplantation for relapsed disease. The clinical relevance of the t(2;5) in older patients requires further study.

Adolescent↗
PubMed1996

Adjuvant chemotherapy of childhood posterior fossa ependymoma: cranio-spinal irradiation with or without adjuvant CCNU, vincristine, and prednisone: a Childrens Cancer Group study.

In 1975, members of The Children's Cancer Group (CCG) initiated a trial for patients with infratentorial medulloblastomas and ependymomas. Patients, all of whom received post-operative cranio-spinal irradiation (CSI), were randomized to receive or not receive adjuvant chemotherapy (CT) with lomustine (CCNU), vincristine, and prednisone for 1 year. Thirty-six of the 42 patients with ependymoma entered on study were suitable for analysis; 22 received combined modality therapy and 14 irradiation (RT) alone. The failure-free survival (FFS) for the entire sample at 10 years is 36% and overall survival (OS) 39%, with no difference in outcomes between the two regimens. Survival was better for females (73%) than males (21%) and for those older than 10 years (51% vs. 31%). There were two toxic deaths in the group receiving CT. We conclude from this study with long-term follow-up that the CT used was not effective in improving the outcome in children with ependymoma.

Adolescent↗
PubMed1996

Effect of capacitive coupled electrical stimulation on regenerate bone.

An in vivo study was carried out to determine if capacitive coupled electrical stimulation increased the rate of recovery of strength of regenerate bone produced as a result of lengthening by the Ilizarov technique. Thirty-four adult male beagles underwent a right tibial mid-diaphyseal corticotomy, followed by a 5-day delay, and then 21 days of lengthening (1 mm/day). At the start of the post-distraction period (day 27), stimulation (3-6.3 V peak to peak, 5-10 mA root-mean-square at 60 kHz) was applied for 28 days to one group. The nonstimulated group (n = 17) underwent a 28-day period with no stimulation. From each group, four tibiae were prepared for histology; both ends of the remaining bones were embedded in polymethylmethacrylate and tested in torsion (internal rotation at 4.7 degrees/sec) until failure. Statistically significant changes included a 37% lower maximum torque capacity and a 40% decrease in strain energy to failure in the stimulated group compared with the nonstimulated group. The findings are supported by measured trends to a lower modulus of rigidity (37% decrease) and a smaller percentage of active osteoid perimeter (20% decrease) for the stimulated group. The experimental data suggest that when this dose of capacitive coupled electrical stimulation is applied to the regenerating bone created during distraction osteogenesis, it delays the recovery of bone strength compared with an untreated control.

Animals↗
PubMed1996

Working memory: activation limitations on retrieval.

Two experiments which require subjects to hold a digit span while solving an equation and then recall the digit span are performed. The size of the memory span and the complexity of the equation are manipulated as well as whether the subject is required to substitute items from the digit span for constants in the equation. As either task (digit span recall or equation solving) gets more complex there are performance decrements (accuracy or latency) not only in that task but also in the other task. It is also shown that the majority of the errors are misretrievals. These results are consistent with the proposal that working memory load has its impact on retrieval from memory. These results are fit by the ACT-R theory (Anderson, 1993) which assumes that there is a limit on source activation and that this activation has to be divided between the two tasks. As either task increases in complexity there is less activation for retrieval of information from declarative memory. Subjects' misretrievals of associatively related information could be predicted by assuming a partial matching process in ACT-R.

Adult↗
PubMed1996

Mitochondrial abnormalities in oculopharyngeal muscular dystrophy.

This report describes a 56-yr-old man with a dominantly inherited disorder affecting four generations and characterized by bilateral ptosis and dysphagia. Muscle biopsy showed only minor light microscopic abnormalities but electron microscopy revealed fibres containing paracrystalline mitochondrial inclusions. Southern analysis of mitochondrial DNA obtained from muscle did not reveal mitochondrial gene deletions. An extensive search eventually identified the characteristic intranuclear filaments of oculopharyngeal muscular dystrophy (OPMD). Abnormal mitochondria are non-specific epiphenomena in OPMD but a potential source of confusion with a late-onset mitochondrial cytopathy. This case further emphasizes the necessity for a diligent search for the diagnostic intranuclear filaments when oculopharyngeal muscular dystrophy is suspected clinically.

Blepharoptosis↗
PubMed1996

Categorization and sensitivity to correlation.

Three categorization experiments were run in which participants saw a set of stimuli that varied on 4 continuous dimensions. Participants first categorized the stimuli and tried to predict some of the dimensions, given the values of others. Experiment 1 used iris-like stimuli based on the descriptions of R. A. Fisher's (1936) taxonomic descriptions. It showed that having participants categorize the stimuli was essential to being able to perform the prediction task and that merely observing the stimuli was not sufficient. It also indicated that participants could use within-category as well as between-category correlations for predictions. Experiments 2 and 3 used stimuli with artificial variations of values. Participants processed categories that had different within-category correlations. Participants' behavior could be predicted as a combination of sensitivity to within-category correlation and bias about the sign of the correlations. These results were fit to the rational model of categorization (J. R. Anderson, 1991) and to an exemplar model (R. M. Nosofsky, 1988).

Adult↗