Search PubMed⌕ Search

Biomedical subjects

J Saiki

Publications and source records attributed to J Saiki.

At least 19 recordsLinked to original sources
PubMed2001

[Determinants of occurrence of negative priming for novel shapes with matching paradigm].

We examined the effect of relation between interferences from distractor and inhibitory mechanism on the occurrence of negative priming, by using a matching paradigm. The ease of perceptual target selection was determined by magnitudes of interference. Stereoscopic depth was used to manipulate the relative position of a target, a distractor and a standard figure. When the ease of perceptual target selection was manipulated by separation of the target from the distractor in depth, positive priming occurred. However, the ease of target selection turned out to be unnecessary in the occurrence of priming effects. When the distractor and the standard figure were displayed at the same depth plane, where the distractor was supposed to interfere with the encoding of a standard figure, negative priming occurred consistently regardless of the ease of perceptual target selection. This study suggests that inhibitory mechanism contributes to the suppression of inappropriate processes by distractor, and inhibitory mechanism actively keeps distractors from interfering with standard figures.

Adult↗
PubMed2000

Occlusion, symmetry, and object-based attention: comment on Behrmann, Zemel, and Mozer (1998).

The validity of M. Behrmann, R. Zemel, and M. Mozer's (1998) finding that object-based attention can be directed toward occluded objects is examined in 3 experiments. In M. Behrmann et al.'s (1998) original study, participants made speeded judgments of whether the numbers of bumps attached to 2 arms of an X shape were the same or different. The 2 sets of bumps belonged either to a single object, 2 different objects, or 2 separated parts of an occluded object. Unfortunately, this objecthood manipulation was confounded by the symmetry of the stimuli. Experiment 1 replicated M. Behrmann et al.'s main results using identical stimuli. Experiments 2a and 2b dissociated objecthood from symmetry. The results suggest that the effects of object-based attention found by M. Behrmann et al. are largely due to symmetry. The stimuli used in M. Behrmann et al. are not appropriate for examining the relation between object-based attention and occlusion.

Adult↗
PubMed1998

Connectedness and the integration of parts with relations in shape perception.

Seven experiments investigated whether part connectedness would facilitate the perception of spatial relations among object parts. Experiments 1-4 showed that objects composed of connected parts are easier to distinguish from distractors in rapid serial visual presentation sequences than objects composed of separated parts and that this effect cannot be attributed to the presence of local features in the connected images. Experiments 5 and 6 revealed that image-based connectedness is neither necessary nor sufficient for the connectedness effect, and Experiment 7 showed that the connectedness effect is not a simple feature conjunction effect (i.e., it does not hold in a shape-color conjunction search task). These findings are consistent with the claim, central to the structural description theories, that the visual system not only decomposes objects into parts but also explicitly integrates those parts with their spatial relations.

Adult↗
PubMed1998

Connectedness and part-relation integration in shape category learning.

We investigated the role of connectedness in the use of part-relation conjunctions for object category learning. Participants learned categories of two-part objects defined by the shape of one part and its location relative to the other (part-relation conjunctions). The topological relationship between the parts (connected, separated, or embedded) varied between participants but was invariant for any given participant. In Experiment 1, category learning was faster and more accurate when an object's parts were connected than when they were either separated or embedded. Subsequent experiments showed that this effect is not due to conscious strategies, differences in the salience of the individual attributes, or differences in the integrality/separability of dimensions across stimuli. The results suggest that connectedness affects the integration of parts with their relations in object category learning.

Adult↗
PubMed1996

Attribute conjunctions and the part configuration advantage in object category learning.

Five experiments demonstrated that in object category learning people are particularly sensitive to conjunctions of part shapes and relative locations. Participants learned categories defined by a part's shape and color (part-color conjunctions) or by a part's shape and its location relative to another part (part-location conjunctions). The statistical properties of the categories were identical across these conditions, as were the salience of color and relative location. Participants were better at classifying objects defined by part-location conjunctions than objects defined by part-color conjunctions. Subsequent experiments revealed that this effect was not due to the specific color manipulation or the role of location per se. These results suggest that the shape bias in object categorization is at least partly due to sensitivity to part-location conjunctions and suggest a new processing constraint on category learning.

Adult↗
PubMed1990

[The process of constructing mental models from spatial descriptions].

This study examined the effect of word order in constructing mental models from spatial descriptions. In Experiment 1, 24 graduate and undergraduate students read three sentences in length of spatial descriptions and verified location diagrams. Experimental factors were word order and propositional combinations. In single sentence processing, reading times (RTs) of Subject-Location-Verb (SLV) word order condition were longer than RTs of Location-Subject-Verb (LSV) condition. In the integration process, the effect of propositional combinations (reflected in RTs of the second sentence) were found only in the LSV condition. To clarify the integration process, the word order of the second sentence was changed in Experiment 2. Compared with the result of Experiment 1 (with both the first and the second sentence SLV). RTs of the second SLV sentence (with the first LSV) were reduced. These results support the hypothesis that the integration process is carried out by on-line processing, and that subjects use not only proportional representations of text, which contain logical relations of terms, but also surface structure information such as word order in constructing mental models.

Adult↗
PubMed1989

Granulocyte colony-stimulating factor stimulates recovery of granulocytes in patients receiving dose-intensive chemotherapy without bone marrow transplantation.

Bone marrow colony-stimulating factors (CSF) ameliorate hematologic toxicity of standard chemotherapy regimens and may allow relatively safe use of intensive and more efficacious doses of anticancer drugs. Twenty-four patients with cancers for which no standard regimens were likely to be effective received repeated courses of a combination of cisplatin (150 mg/m2), etoposide (1,500 mg/m2), and cyclophosphamide (5,000 mg/m2) at doses for which bone marrow transplantation is usually used. A total of 10 patients received escalating doses of recombinant human granulocyte CSF (rhG-CSF); 11 patients receiving identical chemotherapy and supportive therapy without rhG-CSF served as controls for the first cycle of therapy. Five of these patients and 3 additional patients also served as their own controls, receiving rhG-CSF for all cycles after the first. No patient received bone marrow transplantation. rhG-CSF shortened the median duration of severe granulocytopenia (less than or equal to 100/mm3) in a dose-related fashion (P less than .03; Kruskal-Wallis test). Patients not receiving rhG-CSF had a median of 8.5 days of granulocytopenia. Those receiving 40 micrograms/kg of rhG-CSF for approximately 20 days from the third day after chemotherapy had a median of 7.0 days (P less than .23) and those receiving 60 micrograms/kg had a median of 5.5 days (P less than .007) of granulocytopenia. An rhG-CSF dose of 20 micrograms/kg had no effect. Recovery to a granulocyte count of at least 500/mm3 took a median of 12 days in the control group and 8 days (P less than .03) in patients receiving rhG-CSF at a dose of 60 mg/kg. The duration of antibiotic therapy (a median, 9.0 days v 5.0 days) was shortened with the two higher and effective doses of rhG-CSF compared with control patients. The duration of hospitalization (median of 20 days v 19 days) was not shortened. These findings that rhG-CSF decreases the risk of granulocytopenia associated with this particular dose-intensive chemotherapy regimen therapy administered without bone marrow transplantation.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1987

Combination chemotherapy using adriamycin, DTIC, cyclophosphamide, and actinomycin D for advanced soft tissue sarcomas: a randomized comparative trial. A phase III, Southwest Oncology Group Study (7613).

The term soft tissue sarcoma refers to a large variety of malignant tumors arising in extraskeletal connective tissues that connect, support, and surround discrete anatomic structures. All visceral organs also contain a connective stroma that can undergo malignant transformation. Because of the histological similarities of this group of tumors and their relative rarity, treatment prescriptions for patients that have disseminated disease are most often uniform. In this study, we asked the question whether adding a third drug (cyclophosphamide or actinomycin D) to Adriamycin (Adr [Adria Laboratories, Columbus, OH])-(3,3-dimethyl-1-triazeno)- imidazole-4-carboxamide (DTIC) would improve the response rate and/or survival. A unique feature of this cooperative group clinical trial was the mandatory pathology review of the histological material. All patients of the Southwest Oncology Group between June 1, 1976, and November 17, 1979, who had a biopsy-confirmed diagnosis of a soft tissue sarcoma with convincing clinical or biopsy-documented evidence of metastatic disease were eligible for the study. Patients were randomized to receive (1) Adr, 60 mg/m2 intravenously, day 1, and DTIC, 250 mg/m2 every 3 weeks (104 patients); (2) Adr and DTIC as in (1) and cyclophosphamide, 500 mg/m2, day 1 (112 patients); or (3) Adr and DTIC as in (1) and actinomycin D, 1.2 mg/m2, day 1, (119 patients). There was no statistically significant difference in response rates (33%, 34%, and 24%) (P = .25). Median durations of response were 31 weeks in the Adr-DTIC arm, 26 weeks in the cyclophosphamide-DTIC-Adr arm, and 23 weeks in the Adr-DTIC-Actinomycin D arm (P = .78). Median durations of survival were 37, 42, and 50 weeks, respectively. Again, no statistically significant differences were observed (P = .59). Toxicities from each of these treatment arms were formidable and were equivalent. Prognostic factor analysis showed a prognosis based on bone marrow reserve, sex, and pathology subtype favorable to patients.

Adolescent↗
PubMed1982

Combination chemotherapy, radiotherapy, and BCG immunotherapy in limited small-cell carcinoma of the lung: a Southwest Oncology Group Study.

From November 1976 to March 1979 the Southwest Oncology Group treated 298 patients with limited (disease confined to the chest and encompassed by one radiotherapy port) small-cell carcinoma of the lung with combination chemotherapy and radiotherapy with or without BCG immunotherapy. Two induction chemotherapy programs were utilized: (1) cyclophosphamide, vincristine, methotrexate, fluorouracil; or (2) cyclophosphamide, doxorubicin, and vincristine. Patients received 4500 rads of radiation therapy to the bulk primary tumor and 3000 rads to whole brain followed by maintenance chemotherapy. One-half of all the patients were randomized to receive one vial (5 x 10(8)) of high viability Pasteur BCG by scarification technique given on days 8 and 15 of each 21--28 day treatment cycle. Increased granulocytopenia accompanied the addition of BCG immunotherapy. Patients receiving BCG achieved a response rate of 49% vs. those patients not receiving BCG of 44% (P = 0.579). Median response duration was 40 weeks for the BCG arms and 38 weeks for the arms without BCG; survival was no different, 42 weeks for the BCG arms vs. 50 weeks for the arms without BCG. In patients who responded to therapy and survived longer than one year, those who continued to receive BCG therapy demonstrated a slight, yet significant, survival benefit over those patients not receiving BCG (93 weeks vs. 81 weeks, P = 0.03). It appears that BCG immunotherapy has no beneficial effect on response rate, duration of response, or survival in programs using chemotherapy and radiotherapy for control of limited small-cell carcinoma of the lung except in this small group of long-term survivors.

Antineoplastic Agents↗
PubMed1982

Phase II trial of m-AMSA in hepatocellular carcinoma: a Southwest Oncology Group Study.

Twenty-three patients with heptocellular carcinoma were treated with m-AMSA at a dose of 120 mg/m2 iv repeated at 4-week intervals. Toxicity was primarily hematologic. Partial responses occurred in two of 14 previously treated patients and in one of nine previously untreated patients. The overall activity of m-AMSA in patients with hepatocellular carcinoma appears minimal.

Adolescent↗
PubMed1982

Perinephric and intranephric abscesses: a review of the literature.

Perinephric and intranephric (renal cortical and corticomedullary) abscesses, which may coexist, are associated with considerable mortality (21 percent to 56 percent) and are often difficult to diagnose. Most cases of renal cortical abscess are due to hematogenous seeding from distant foci of infection (often involving Staphylococcus aureus), while corticomedullary and perinephric abscesses are most often due to complications of urinary tract infections. Newer noninvasive studies such as ultrasonography, computerized tomography, gallium scanning and indium-labeled leukocyte scanning may facilitate determination of the diagnosis. While antibiotic therapy alone may suffice for the treatment of cortical abscesses, surgical drainage is an added requirement for the treatment of perinephric abscess.

Abscess↗
PubMed1981

Femoral neuropathy: a complication of renal transplantation.

Femoral neuropathy occurred in 3 patients after renal transplantation. This appeared to be due to compression of the femoral nerve by medial and inferior blades of the self-retaining retractors used during renal transplantation surgery. The condition resulted in weakness of quadriceps muscles, loss of patellar reflex, and sensory deficit on the side of transplantation surgery. The rate of recovery from neurologic deficits appeared to depend on the level of transplant renal function.

Adult↗
PubMed1980

Methyl CCNU and adriamycin for patients with metastatic sarcomas: a Southwest Oncology Group study.

This protocol study (SWOG-7431) combining adriamycin and methyl CCNU (MAD) for metastatic sarcomas was initially used on patients who were refractory to cytoxan, vincristine, and/or actinomycin-D. After the initial good results, the study was expanded to include any untreated patients with metastatic sarcoma. The initial starting dose of adriamycin was 60 mg/M2 on day 1 and 45 mg/M2 on day 22. Methyl CCNU was given once every six weeks at an initial dose of 150 mg/M2 orally. Fifty-five patients received therapy and 53 were evaluable for response. The complete remission rate was 9.4%. The partial remission rate was 35.9%, with a total complete and partial remission rate of 45.3%. The median survival time was ten months. When the combination of cytoxan, DIC, vincristine and adriamycin was used, the response rate was similar and the median survival time in eligible patients was 10 months. The methyl CCNU and adriamycin combination is more convenient for the patient because it necessitates fewer clinic visits and significantly fewer injections than other combinations. These data suggest that treatment with methyl CCNU, when combined with adriamycin, increases the response rate and survival time over adriamycin alone, but that the response is similar to that seen with the combination of cytoxan, DIC, vincristine, and adriamycin.

Age Factors↗
PubMed1980

Hemodialyzability of acetazolamide.

Because the dialyzability of acetazolamide is not known, we undertook a study to determine the in vivo dialysance of this drug and found it to average 22 ml per minute. The quantity of the drug removed by four hours of dialysis was approximately 30% of the dose administered intravenously one half hour before dialysis. Accordingly, considerable amounts of the drug are removed by dialysis, despite its high intraerythrocytic distribution and plasma protein binding properties. Therefore, hemodialysis may be effective in the management of acetazolamide overdose, particularly when complicated by the presence of renal failure. The dialysance can vary under different dialyzing conditions. An acetazolamide/urea nitrogen extraction ratio of 0.16 established in this study can be used to predict the acetazolamide dialysance in various dialyzing conditions.

Acetazolamide↗
PubMed1980

Antidiuretic hormone in end-stage renal disease.

Quantative data on plasma levels of antidiuretic hormone (ADH) in renal failure are limited. We measured predialysis plasma ADH levels using a double antibody radioimmunoassay in 14 patients with end-stage renal failure. Plasma ADH was inappropriately elevated in the majority of tested patients despite normal plasma osmolality, moderately elevated blood pressure, and hypervolemia. The etiology of increased plasma ADH in our population is unclear.

Adult↗
PubMed1980

Hemodialysis studies of antidiuretic hormone.

Hemodialyzability of antidiuretic hormone (ADH) was studied in 14 patients undergoing hemodialysis procedure. In addition hemofiltration (dry dialysis) was performed in 8 patients and hemofiltrate samples were collected for ADH assay. The mean values for plasma ADH level in ingoing and outgoing blood were nearly identical. Moreover, no ADH was detectable in the hemofiltrate samples. These findings suggest lack of significant ADH removal by dialysis or hemofiltration.

Adult↗
PubMed1978

Unmaintained remissions in multiple myeloma.

Twenty-eight patients with multiple myeloma responding to prior melphalan-prednisone combinations, but without additional chemotherapy, were followed until relapse. Patients receiving no further treatment had a median survival time similar to that of those receiving indefinite courses of melphalan-prednisone or carmustine-prednisone. Prolonged periods of unmaintained remission occurred primarily in patients without extensive disease at the time of diagnosis or in whom the abnormal protein disappeared from the electrophoresis strip. The initial relapse after an unmaintained remission was controlled in 80% of patients with the resumption of melphalan-prednisone, but second remissions were usually less marked in degree and shorter in duration. Results supported the long-term evaluation without chemotherapy of selected patients with low numbers of plasma cells after treatment who were likely to experience long durations of disease stability and respond again to retreatment with melphalan-prednisone.

Cell Transformation, Neoplastic↗