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Biomedical subjects

D Chi

Publications and source records attributed to D Chi.

At least 19 recordsLinked to original sources
PubMed2004

Milk and milk products consumption in relationship to serum lipid levels: a community-based study of middle-aged and older population in Japan.

The authors examined the association of milk and milk products consumption (MMPC) with serum lipid profiles including total cholesterol (TC), triacylglycerols (TG), HDL cholesterol (HDLC), LDL cholesterol (LDLC), and TC/HDLC ratio in a community-based sample. The study population comprised 461 men and 834 women aged 40-79 years who, in 2001, participated in an annual healthy examination and a lifestyle related survey Consumption frequency of 17 foods, including milk and milk products, was determined by a self-administered questionnaire. The participants were asked by "Do you drink cow's milk or eat milk products such as yoghurt and cheese everyday?", and two groups ("Yes" and "No") of MMPC were classified. Multiple linear regression analyses were conducted to examine the relationships between MMPC and 5 serum lipid profile levels adjusted for sex, age, body mass index (BMI), alcohol consumption, smoking, physical activity, and fat intake. Univariate and multivariate analyses indicated inverse associations of MMPC with TC, HDLC, and LDLC, and that the "Yes" group had higher adjusted means of serum TC by 7.133 mg/100 ml (p < 0.001), HDLC by 1.844 mg/100 ml (p < 0.05), LDLC by 5.459 mg/100 ml (p < 0.001). We suggested that MMPC has an association with serum lipid and lipoprotein levels and that MMPC may have an unfavorable effect on hypercholesterolaemia in the Japanese population.

Adult↗
PubMed2001

Radical surgical resection and high-dose intraoperative radiation therapy (HDR-IORT) in patients with recurrent gynecologic cancers.

OBJECTIVE: To determine the outcome for patients with recurrent gynecologic tumors treated with radical resection and combined high-dose intraoperative radiation therapy (HDR-IORT). METHODS AND MATERIALS: Between November 1993 and June 1998, 17 patients with recurrent gynecologic malignancies underwent radical surgical resection and high-dose-rate brachytherapy. The mean age of the study group was 49 years (range 28-72 years). The site of the primary tumor was the cervix in 9 (53%) patients, the uterus in 7 (41%) patients, and the vagina in 1 (6%) patient. The treatment for the primary disease was surgery with or without adjuvant radiation in 14 (82%) patients and definitive radiation in 3 (18%) patients. The current surgery consisted of exenterative surgery in 10 (59%) patients and tumor resection in 7 (41%) patients. Complete gross resection was achieved in 13 (76%) patients. The mean HDR-IORT dose was 14 Gy (range 12-15). Additional radiation in the form of permanent Iodine-125 implant was given to 3 of 4 patients with gross residual disease. The median peripheral dose was 140 Gy. RESULTS: With a median follow-up of 20 months (range 3-65 months), the 3-year actuarial local control (LC) rate was 67%. In patients with complete gross resection, the 3-year LC rate was 83%, compared to 25% in patients with gross residual disease, p < 0.01. The 3-year distant metastasis disease-free and overall survival rates were 54% and 54%, respectively. The complications were as follows: gastrointestinal obstruction, 4 (24%); wound complications, 4 (24%); abscesses, 3 (18%); peripheral neuropathy, 3 (18%); rectovaginal fistula, 2 (12%); and ureteral obstruction, 2 (12%). CONCLUSION: Radical surgical resection and combined IORT for patients with recurrent gynecologic tumors seems to provide a reasonable local-control rate in patients who have failed prior surgery and/or definitive radiation. Patient selection is very important, however, as only those patients with complete gross resection at completion of surgery appear to benefit most from this radical approach in the salvage setting.

Adult↗
PubMed2001

Identification of risk factors for requiring transfusion during front-line chemotherapy for ovarian cancer.

OBJECTIVE: Anemia requiring red blood cell (RBC) transfusion is common in ovarian cancer (OC) patients receiving post-debulking surgery chemotherapy. Erythropoietin use has been shown to decrease transfusion requirements in patients receiving chemotherapy. We sought to identify pretreatment risk factors that could identify patients at increased risk for requiring RBC transfusion during first-line treatment for ovarian cancer. METHODS: One hundred seventy-five consecutive patients who received chemotherapy with either carboplatin-paclitaxel or cisplatin-paclitaxel following debulking surgery for epithelial OC from 1993 to 1996 were identified. No patient received erythropoietin. Patient characteristics recorded included: age, stage, prechemotherapy hemoglobin, nadir hemoglobin, number of cycles and doses of chemotherapy received. The outcome was requiring RBC transfusion. Independent predictors of requiring RBC transfusion were identified using multivariate analyses. RESULTS: Median age of the cohort was 62 years (range, 28-86). Seventy-one and four-tenths percent had FIGO stage III/IV disease. Median prechemotherapy hemoglobin was 11 g/dL (range, 7.1-15.4); median nadir hemoglobin was 9.3 g/dL (range, 6.6-11.1). One hundred nineteen (66%) patients received cisplatin-paclitaxel, and 61 (34%) received carboplatin-paclitaxel. Of 175 patients, 31 (18%, 95% CI = 12-23%) required RBC transfusion. Independent risk factors for RBC transfusion were prechemotherapy hemoglobin <10 g/dL (P < 0.01, odds ratio = 3.78, 95% CI = 1.52-9.44) and carboplatin-paclitaxel versus cisplatin-paclitaxel treatment (P = 0.01, odds ratio = 3.14, 95% CI = 1.27-7.76). Of 175 patients, 40 (22.8%) had a prechemotherapy hemoglobin <10 g/dL. Fifty percent of patients with prechemotherapy hemoglobin <10 g/dL who received carboplatin-paclitaxel required RBC transfusion, compared with 7.7% of patients with hemoglobin >10 g/dL who received cisplatin-paclitaxel. CONCLUSION: Ovarian cancer patients frequently require RBC transfusion during postdebulking platinum-paclitaxel chemotherapy. Patients with prechemotherapy hemoglobin <10 g/dL and those receiving carboplatin-paclitaxel are at increased risk of requiring RBC transfusion. Early initiation of erythropoietin use in such patients may reduce transfusion needs.

Adult↗
PubMed2001

The costs and efficacy of liposomal doxorubicin in platinum-refractory ovarian cancer in heavily pretreated patients.

OBJECTIVE: In clinical practice, chemotherapy agents demonstrating modest second-line activity against platinum-refractory epithelial ovarian cancer (PROC) are frequently used in patients who have received multiple prior chemotherapy agents. Whether the response rates reported in selected patients can be expected in heavily pretreated patients is not known. Similarly, the costs of palliative chemotherapy are not known. We sought to determine the response, survival, and predictors of response in an unselected cohort of PROC patients receiving liposomal doxorubicin (LD) for relapsed disease, and the overall costs of delivering liposomal doxorubicin in this setting. METHODS: In a cohort of 62 consecutive patients who initiated LD as second- or greater-line therapy for PROC, the following variables were examined: age, number of prior regimens for relapse disease, duration of first clinical remission, time from last prior treatment, dose intensity of LD received, response/clinical benefit, time to progression, toxic effects, and survival. Multivariate analyses were used to identify predictors of clinical benefit and overall survival. Direct medical charges were calculated and converted to costs, and major cost drivers determined. RESULTS: Sixty-two patients received a total of 174 cycles of LD. The mean number of cycles per patient was 2 (range, 1-8); the median number of prior regimens for recurrent PROC was 2 (range, 0-8); and the median duration of the first clinical remission was 6 months. Median dose intensity of LD delivered was 11.4 mg/m(2)/week (range, 2.8-16.7 mg/m(2)/week). Nine of sixty-two patients (14.5%) had an objective clinical response by CA-125 and/or CT scan (95% confidence interval, 6-23%). Grade 3/4 toxicity occurred in 11% of patients. In the full cohort, median time to progression was 2.2 months, and median overall survival, 9.6 months (range, 0.2-26 months). Dose intensity was the only independent predictor of overall response. Duration of first clinical remission and number of prior salvage regimens were associated with longer overall survival. The mean total direct medical cost per cycle of LD was $5763, and the major cost drivers were hospitalizations and drug acquisition/delivery costs. CONCLUSION: LD is an active agent in PROC, even when used as greater-than-second-line therapy. Among heavily pretreated patients, delivering a dose intensity of at least 9.0 mg/m(2)/week was associated with a higher probability of response. The cost per cycle of LD is driven by hospitalizations and drug acquisition/delivery costs.

Adult↗
PubMed2000

Continent urinary diversion and low-rectal anastomosis in patients undergoing exenterative procedures for recurrent gynecologic malignancies.

OBJECTIVE: The aim of this study was to review the complications associated with continent urinary diversion and associated procedures in patients with gynecologic malignancies. METHODS: We retrospectively reviewed the medical records of all patients who underwent construction of a continent urinary conduit between October 1991 and October 1998 on the Gynecology Service at Memorial Sloan-Kettering Cancer Center. RESULTS: Thirty-three patients were identified, of whom 22 underwent total pelvic exenteration, 8 underwent anterior exenteration, and 3 underwent urinary diversion procedures only. Complications associated with the urinary diversion procedure included ureteral strictures (2), pouch leakage (2), mild hydronephrosis, (6), pyelopnephritis (2), nocturnal incontinence (5), and difficulty with self-catheterization (2). Additional procedures performed concomitantly with continent urinary diversion and exenteration included pelvic reconstruction (18), low-rectal anastomosis (13), and intraoperative radiation therapy (9). The most significant morbidity was seen in patients undergoing concomitant low-rectal anastomosis, in whom the rate of anastomotic leaks was 54% (7 of 13 patients). CONCLUSIONS: Continent urinary diversion can successfully be accomplished at the time of exenteration in patients with recurrent gynecologic malignancies. The rate of major complications related to the urinary diversion is small and most complications can be managed nonsurgically. The greater than 50% rate of anastomotic leaks in patients undergoing concomitant low-rectal anastamosis suggests that such anastomosis should not be undertaken in this group of patients.

Adult↗
PubMed2000

The effects of HIV infection on endothelial function.

Endothelial dysfunction and/or injury is pivotal to the development of cardiovascular and inflammatory pathology. Endothelial dysfunction and/or injury has been described in Human Immunodeficiency Virus (HIV) infection. Elaboration of circulating markers of endothelial activation, such as soluble adhesion molecules and procoagulant proteins, occurs in HIV infection. Certain endothelial cells, such as those lining liver sinusoids, human umbilical vein endothelial cells, bone marrow stromal endothelial cells or brain microvascular endothelial cells, have been shown to be variably permissive for HIV infection. Entry of virus into endothelial cells may occur via CD4 antigen or galactosyl-ceramide receptors. Other mechanisms of entry including chemokine receptors have been proposed. Nevertheless, endothelial activation may also occur in HIV infection either by cytokines secreted in response to mononuclear or adventitial cell activation by virus or else by the effects of the secreted HIV-associated proteins, gp 120 (envelope glycoprotein) and Tat (transactivator of viral replication) on endothelium. Enhanced adhesiveness of endothelial cells, endothelial cell proliferation and apoptosis as well as activation of cytokine secretion have all been demonstrated. Synergy between select inflammatory cytokines and viral proteins in inducing endothelial injury has been shown. In HIV infection, dysfunctional or injured endothelial cells potentiate tissue injury, inflammation and remodeling, and accelerate the development of cardiovascular disease.

Animals↗
PubMed2000

[Biological characteristics and occurrence regularity of Phassus excrescens Bulter].

The biological characterisitics and occurrence regularity of Phassus excrescens were studied from 1997 to 2000 in the eastern part of Heilongjiang Province and Jilin Province. In this area, most of its individuals took two years to finish one generation, and over-wintered two times with eggs and larvae, respectively. At the end of June or the first ten days of July, larvae transferred to damage Fraxinus mandshurica. Feeding with artificial diet indoor, the larvae finished 6 instars before pupation. In artificial Manchurican ash forest, the larva mainly damaged the truck basal(below 20 cm) or truck of 2 to 20 years old Fraxinus mandshurica. The occurrence amount of this species was closely related to the forest age and the stand structure. Usually, pure artificial Fraxinus mandshurica stands and Fraxinus mandshurica-Pinus koraiensis mixed stands were damaged seriously, while Fraxinus mandshurica-Larix mixed forests were damaged lightly.

Animals↗
PubMed1996

Long-term effects of antidepressants on balance, equilibrium, and postural reflexes.

To assess the long-term effects of antidepressant medication on balance, equilibrium, and postural reflexes, we studied 30 patients, ages 20-76 years, who had a diagnosis of depressive disorder (as defined by DSM-III-R criteria) and had been treated with tricyclic antidepressants (TCAs) or selective serotonin reuptake inhibitors (SSRIs) for > or = 1 year. They were assessed by a Balance Master System. The assessment included three tasks: static balance, rhythmic weight shift, and limits of stability. When compared with 30 nonhospitalized healthy controls (of comparable age and the same sex), patients who took TCAs showed impaired balance function in all main indices. The results suggest that the impairment of balance function includes motor coordination, fine-motor control, postural reflexes, maintaining equilibrium, and reaction time. No obvious impairment of balance function was observed in patients who took SSRIs.

Adult↗
PubMed1994

Single missense mutation in the tyrosine kinase catalytic domain of the RET protooncogene is associated with multiple endocrine neoplasia type 2B.

Multiple endocrine neoplasia type 2B (MEN 2B) is a human cancer syndrome characterized by medullary thyroid carcinoma (MTC), pheochromocytomas, mucosal neuromas, ganglioneuromas of the intestinal tract, and skeletal and ophthalmic abnormalities. It appears both as an inherited disorder and as de novo disease. Sequence analysis of germ-line DNA from MEN 2B patients revealed the existence of the same point mutation in the RET protooncogene in 34 unrelated individuals. This sequence difference was not observed in 93 unaffected individuals, including the normal parents of 14 de novo MEN 2B patients. The mutation (ATG-->ACG) results in the replacement of methionine with threonine within the catalytic core region of the tyrosine kinase domain. We propose that this amino acid replacement effects substrate interactions and results in dominant oncogenic activity by the RET protein. Missense mutations in the extracellular ligand-binding domain of the RET protooncogene previously have been associated with two other disorders [MEN 2A and familial MTC (FMTC)] in which MTC is observed. MEN 2B represents the third form of heritable MTC known to be an allele of RET. Alterations in two different functional domains of the putative receptor protein tyrosine kinase are implicated in development of MTC.

Alleles↗
PubMed1993

Lymphocytes infiltrating rat cardiac allografts express a limited repertoire of T cell receptor V beta genes.

The T cell response to many self-MHC-restricted nominal Ag involves limited use of the TCR repertoire. The status of the TCR repertoire in allogeneic responses remains unclear. In this report, we have studied the TCR V beta gene repertoire involved in the rejection of cardiac allografts disparate for major and minor histocompatibility Ag in rats. Graft-infiltrating lymphocytes (GIL) were isolated from rejecting heart allografts and analyzed for the expression of the V beta repertoire using a cDNA library and a semiquantitative polymerase chain reaction (PCR). We report here that GIL isolated at early stages of the rejection reaction preferentially use the V beta 4 gene. First, V beta 4 comprised 36.4% (8/22) of randomly sequenced cDNA clones isolated from a TCR-beta chain-specific cDNA library established from GIL harvested 3 days posttransplantation. The V beta 4 gene in these clones was found in conjunction with several different J beta and N regions, suggesting a dominant role for the V beta 4 encoded domains in the recognition of allograft Ag. Second, the V beta 4 message comprised 56.6 to 65.7% of the transcripts expressed by the 20 rat V beta genes in three T cell lines established from GIL isolated 2 days posttransplantation. Third, fresh, unmanipulated GIL harvested at days 2 and 3 posttransplantation predominantly expressed the V beta 4 gene. Fourth, the expression of V beta 4 in naive splenocytes constituted only 5.4% of the V beta detected, suggesting that the predominant use of the V beta 4 gene by GIL was not a consequence of its high level of expression in the periphery. The limited use of the TCR repertoire in allograft rejection may provide the opportunity to interrupt the rejection process and induce donor-specific tolerance by targeting a select population of T cells for inactivation or elimination.

Amino Acid Sequence↗
PubMed1993

Identification of a human achaete-scute homolog highly expressed in neuroendocrine tumors.

Basic helix-loop-helix transcription factors of the achaete-scute family are instrumental in Drosophila neurosensory development and are candidate regulators of development in the mammalian central nervous system and neural crest. We report the isolation and initial characterization of a human achaete-scute homolog that is highly expressed in two neuroendocrine cancers, medullary thyroid cancer (MTC) and small cell lung cancer (SCLC). The human gene, which we have termed human achaete-scute homology 1 (hASH1), was cloned from a human MTC cDNA library. It encodes a predicted protein of 238 aa that is 95% homologous to mammalian achaete-scute homolog (MASH) 1, a rodent basic helix-loop-helix factor. The 57-residue basic helix-loop-helix domain is identical to that in the rodent gene, and the basic and helical regions, excluding the loop, are 72-80% identical to Drosophila achaete-scute family members. The proximal coding region of the hASH1 cDNA contains a striking 14-copy repeat of the triplet CAG that exhibits polymorphism in human genomic DNA. Thus, hASH1 is a candidate locus for disease-causing mutations via triplet repeat amplification. Analysis of rodent-human somatic cell hybrids permitted assignment of hASH1 to human chromosome 12. Northern blots revealed hASH1 transcripts in RNA from a human MTC cell line, two fresh MTC tumors, fetal brain, and three lines of human SCLC. In contrast, cultured lines of non-SCLC lung cancers and a panel of normal adult human tissues showed no detectable hASH1 transcripts. Expression of hASH1 may provide a useful marker for cancers with neuroendocrine features and may contribute to the differentiation and growth regulation of these cells.

Adrenal Gland Neoplasms↗
PubMed1993

A 1.5-megabase yeast artificial chromosome contig from human chromosome 10q11.2 connecting three genetic loci (RET, D10S94, and D10S102) closely linked to the MEN2A locus.

The genetic loci RET, D10S94, and D10S102 from human chromosome 10q11.2 are very closely linked to a locus responsible for the multiple endocrine neoplasia type 2 (MEN2A and MEN2B) and medullary thyroid carcinoma (MTC1) familial cancer syndromes. We have constructed a 1.5-megabase contig consisting of six genomic yeast artificial chromosome clones which include these loci and define their physical order. A critical crossover event has been identified within the map interval; this event places the MEN2A locus centromeric to D10S102 and defines the orientation of the physical map on the chromosome. The orientation of the contig and order of the markers are centromere-RET-D10S94-D10S102-telomere. In addition, a microsatellite repeat polymorphism with a heterozygosity of 71% at the RET locus and a restriction fragment length polymorphism with a heterozygosity of 42% detected by a lambda clone from the D10S94 locus have been developed for high-resolution genetic linkage mapping and predictive diagnostic testing. These data place three important markers on a contiguous physical map, narrow the MEN2 disease locus interval, and provide a framework for further candidate gene identification efforts. Placement of these genetic loci along a clone-based map and continued expansion of the contig will also facilitate efforts to determine the relationship of physical to genetic distance near the centromeres of human chromosomes.

Base Sequence↗
PubMed1993

Mutations in the RET proto-oncogene are associated with MEN 2A and FMTC.

Multiple endocrine neoplasia type 2A (MEN 2A) and familial medullary thyroid carcinoma (FMTC) are dominantly inherited conditions which predispose to the development of endocrine neoplasia. Evidence is presented that sequence changes within the coding region of the RET proto-oncogene, a putative transmembrane tyrosine kinase, may be responsible for the development of neoplasia in these inherited disorders. Single strand conformational variants (SSCVs) in exons 7 and 8 of the RET proto-oncogene were identified in eight MEN 2A and four FMTC families. The variants were observed only in the DNA of individuals who were either affected or who had inherited the MEN2A or FMTC allele as determined by haplotyping experiments. The seven variants identified were sequenced directly. All involved point mutations within codons specifying cysteine residues, resulting in nonconservative amino acid changes. Six of the seven mutations are located in exon 7. A single mutation was found in exon 8. Variants were not detected in four MEN 2B families studied for all exon assays available, nor were they detectable in 16 cases of well documented sporadic medullary thyroid carcinoma or pheochromocytoma that were tested for exon 7 variants. Coinheritance of the mutations with disease and the physical and genetic proximity of the RET proto-oncogene provide evidence that RET is responsible for at least two of the three inherited forms of MEN 2. Neither the normal function, nor the ligand of RET are yet known. However, its apparent involvement in the development of these inherited forms of neoplasia as well as in papillary thyroid carcinoma suggest an important developmental or cell regulatory role for the protein.

Amino Acid Sequence↗
PubMed1993

Effect of moderate exercise on proliferative responses of peripheral blood mononuclear cells.

We studied the effects of 30 minutes of exercise on T lymphocyte counts and proliferative responses of peripheral blood mononuclear cells (PBMC) in 25 runners. Exercise resulted in a T lymphocytosis in the immediate post-exercise period in all subjects (p < 0.001), and reduced CD4+/CD8+ ratios in 22/25 subjects (p = 0.001). The change was due primarily to a 2.2-fold increase in CD8+ cells (p < 0.001). Exercise also reduced PBMC mitogenic responses to phytohemagglutinin (PHA) in 13/14 subjects (p = 0.049), and to pokeweed mitogen (PWM) in 11/14 subjects (p = 0.022), but not to concanavalin A. Postrun sera from 5 of 6 subjects inhibited PHA but not PWM responses of resting autologous PBMC with normal CD4+/CD8+ ratios (p < or = 0.05): indomethacin and monocyte depletion blocked the serum inhibition (p = 0.003, p = 0.0006, respectively). We conclude that post-exercise suppression of mitogenic responses to PHA is due to the release of a serum factor(s) capable of inducing prostaglandin synthesis by circulating monocytes, whereas exercise-induced suppression of PWM responses depends primarily on the reversal of CD4+/CD8+ ratios.

Adult↗
PubMed1992

T lymphocytes mediating protection and cellular cytolysis during the course of Mycobacterium tuberculosis infection. Evidence for different kinetics and recognition of a wide spectrum of protein antigens.

Recent evidence suggests the existence of at least two pathways of acquired specific resistance to Mycobacterium tuberculosis infection; the first consisting of cytokine-mediated activation of parasitized host cells by protective T cells, and the second involving the lysis of these cells by cytolytic T cells. Evidence presented in this report shows that both of the above mechanisms are operative in experimentally infected mice, but that they differ markedly in terms of their kinetics of emergence and loss. It was found that protective T cell activity was acquired very early during the course of the infection, and was temporally associated with the onset of bacterial elimination; however, cytolytic activity did not peak until 10 to 20 days later. This report shows further that the target Ag of these effector T cell populations were apparently numerous with no evidence for preferential recognition of a few immunodominant Ag. In view of the preponderance of target proteins in the bacterial filtrate, we present the hypothesis that such proteins secreted or otherwise leaked from the dividing mycobacterium are pinocytosed from the phagosome and used by the infected macrophage as the key protective Ag leading to T cell sensitization. This hypothesis thus explains the preferential requirement for the viable bacterium in the generation of specific resistance, and further explains why protective immunity is generated even while the organism is still multiplying in an apparently unrestrained manner.

Animals↗
PubMed1990

Replication of a study of frequency analysis of the resting awake EEG in mild probable Alzheimer's disease.

In the resting EEG, the percentage power in the delta, theta, alpha, and beta bands and the mean frequency were computed in an occipital-vertex derivation for two samples of subjects. The original sample (n = 79) and the new sample (n = 43) each contained a mild probable Alzheimer's disease (SDAT) group and a healthy elderly control group. Group medians in both samples were higher in the SDAT than in the healthy subjects for percentage delta and theta, and were lower for percentage alpha and beta and for mean frequency. Percentage theta and mean frequency were consistent across the two samples in showing statistically significant differences between SDAT and healthy groups. The ability of each EEG measure to detect individual subjects with SDAT was assessed. The most effective measure, percentage theta, had only modest sensitivity (about 20%), but this was attained at a specificity of 100%. The accurate detection of an individual at the mild stage requires that the predictive value of a positive test be high to avoid misclassification of non-SDAT subjects as SDAT. This, in turn, requires a specificity of virtually 100% when the prevalence is low. The low sensitivity puts several constraints on the usefulness of the EEG. For this reason, when the dementia is at the mild stage the EEG would be a useful detector of probable Alzheimer's disease only under certain limiting conditions, including high prevalence, high specificity, and a willingness to accept a high rate of falsely negative tests.

Aged↗
PubMed1989

A reevaluation of the effect of velocity on induced motion.

Induced motion (IM) was measured as a function of the temporal frequency of inducer oscillation. IM magnitude decreased as frequency increased above .5 Hz. Increasing the amplitude of inducer motion, and thereby its velocity, did not influence the temporal frequency dependence of IM. This suggests that it is the duration of inducer motion, rather than its velocity, that is the critical stimulus feature in studies that report decreased IM with higher frequencies of inducer oscillation. In a separate experiment, the optokinetic nystagmus elicited by the inducing stimulus in the absence of a fixation target displayed frequency-response characteristics similar to those of IM. This finding supports the hypothesis that IM magnitude is proportional to the voluntary effort required to suppress reflexive eye movements while maintaining stable fixation.

Acceleration↗