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Biomedical subjects

C Y Chiu

Publications and source records attributed to C Y Chiu.

At least 55 records · Page 3Linked to original sources
PubMed1994

Varieties of priming.

Recent data from brain-damaged and normal subjects converge to suggest several characteristics of repetition priming: firstly, it is sensitive to the physical and structural properties of input; secondly, it is unaffected by semantic processing at encoding; thirdly, it is frequently preserved in amnesic patients with impaired explicit memory; fourthly, it depends upon perceptual representations processed and stored by modality-specific cortical memory systems; and, finally, it is subject to constraints particular to the task employed and the type of information that is primed.

Auditory Perception↗
PubMed1994

Immunogenicity of Haemophilus influenzae type b tetanus toxoid conjugate vaccine in young infants. The Kaiser-UCLA Vaccine Study Group.

In a prospective, randomized, double-blind efficacy trial, the immunogenicity of 10 lots of Haemophilus influenzae type b capsular polysaccharide-tetanus toxoid conjugate vaccine (PRP-T) was evaluated. More than 10,000 infants received PRP-T or hepatitis B vaccine at about 2, 4, and 6 months of age along with other childhood vaccines. In a subset of infants, geometric mean concentrations of total anticapsular antibody were 0.08, 0.79, and 5.29 micrograms/mL after the first, second, and third doses, respectively. Four lots of reconstituted lyophilized PRP-T vaccine were significantly more immunogenic than 6 lots of aqueous vaccine (P = .03). In a stepwise regression model, the most important additional factors affecting anticapsular antibody concentrations were the time between the third dose and the blood draw, race, and breast-feeding status at 6 months of age. Immune responses to diphtheria and tetanus toxoids were not significantly different for infants given PRP-T or hepatitis B vaccines along with diphtheria-tetanus toxoid-pertussis vaccine.

Antibodies, Viral↗
PubMed1994

Transesophageal echocardiography in diagnosis of infective endocarditis.

STUDY OBJECTIVE: To determine whether transesophageal echocardiography (TEE) was superior to transthoracic echocardiography (TTE) in defining valvular vegetations and diagnosing clinical infective endocarditis (IE) in patients suspected of having this infection. PATIENTS AND METHODS: Between April 1989 and May 1991, 64 febrile patients with clinical and/or microbiologic risk factors for IE were prospectively enrolled. Patients underwent both TEE and TTE, which were interpreted in a blinded fashion as to the patient's clinical status. Clinical criteria for the diagnosis of IE were compared with TEE and TTE findings to delineate the ability of the two echocardiographic techniques to define valvular vegetations and to establish the clinical diagnosis of vegetative IE. RESULTS: Thirty-four valves had typical valvular vegetations demonstrated by either TEE or TTE. Transesophageal echocardiography was more sensitive than TTE in identifying valvular vegetations (33/34 vs 23/34 instances, respectively; p = 0.004). Also, TEE was better at identifying smaller vegetations (< 1 cm) than TTE; 12 patients with such vegetations were identified by TEE as compared with only 5 of 12 identified by TTE (p = 0.02). Of the 64 patients enrolled, 30 (47 percent) were classified as having "definite" or "probable" IE by modified von Reyn criteria. Among these 30 patients, TEE was significantly more sensitive than TTE at documenting vegetative valvular lesions (26/30 [87 percent] vs 18/30 [60 percent], respectively) (p < 0.01). Both TEE and TTE were highly specific (91 percent) in delineating valvular vegetations in this patient population; two of the three false-positive TEE studies for valvular vegetations occurred in patients with a history of IE. All nine periannular complications of IE were identified by TEE, as compared with only two being defined by TTE (p = 0.001). CONCLUSIONS: Transesophageal echocardiography is significantly more sensitive than TTE and highly specific in both confirming the clinical diagnosis of IE, as well as in identifying valvular vegetations in patients at risk for this infection. Our data also support the concept that TEE is the echocardiographic method of choice for defining small vegetations and periannular complications in IE.

Abscess↗
PubMed1993

Perceptual and conceptual cueing in implicit and explicit retrieval.

Subjects saw or heard words in a list (e.g. limerick) and then took two successive tests. The first was a yes/no recognition test in which auditory/visual modality of test words was manipulated orthogonally to the study modality. The second test varied with experimental conditions: subjects produced words to either perceptual (fragment) cues (l- -e-ick) or conceptual cues (What name is given to a lighthearted five-line poem?), under either explicit or implicit retrieval instructions. The major findings were: (a) that regardless of the type of retrieval cue (perceptual or conceptual) the degree of dependency between recognition and cued recall was greater than that between recognition and implicit retrieval; and (b) that modality shifts adversely affected perceptually cued explicit and implicit retrieval, whereas they had no effect either on conceptually cued retrieval or on recognition. These results suggest that the memory system subserving, and the processes involved in, conceptual priming differ from those underlying recognition and perceptual priming.

Analysis of Variance↗
PubMed1993

Comparison of naturally acquired and vaccine-induced antibodies to Haemophilus influenzae type b capsular polysaccharide.

The objective of this study was to assess qualitative differences in the types of Haemophilus influenzae type B (Hib) capsular polysaccharide (polyribosylribitol phosphate [PRP]) antibodies induced in children 15 to 27 months of age by (i) natural exposure, (ii) PRP vaccine, and by (iii) PRP-diphtheria toxoid conjugate vaccine, (iv) PRP-group B Neisseria meningitidis outer membrane vesicle conjugate vaccine, and (v) Haemophilus type B oligosaccharide conjugate vaccine (HbOC). The highest levels of total Hib-PRP antibody measured by radioimmunoassay and immunoglobulin G (IgG) measured by enzyme-linked immunosorbent assay were seen after HbOC immunization. IgG1 Hib-PRP antibodies predominated in all groups, and there were no differences between the groups in the proportion of IgG and IgA Hib-PRP antibodies. However, the proportions of IgM differed significantly by group. The highest proportions of IgM occurred in naturally acquired antibody and after PRP vaccine, and the lowest proportion occurred after HbOC vaccine. IgG light-chain V kappa type alpha PRP antibody was present in all groups, and the level correlated with the total IgG Hib-PRP antibody level. Therefore, HbOC induced the highest concentrations of V kappa II type alpha PRP antibody, and the naturally acquired antibody group had the lowest levels. IgG light-chain V kappa III antibody levels were also highest in the HbOC group, but there was no correlation between V kappa III antibody levels and total amount of IgG Hib-PRP antibody. These data demonstrate qualitative differences in the antibody repertoires induced by natural exposure, the Hib-PRP vaccine, and each of the different Hib conjugate vaccines. We doubt that there are major differences in the protection afforded by these different antibody repertoires, because these differences do not appear to correlate with differences in protective efficacy in older children.

Antibodies, Bacterial↗
PubMed1993

Intussusception reduction by hydrostatic saline enema under sonographical guidance: clinical experience in 33 cases.

During a three-year period from August 1988 to November 1991, 33 infants and children with 35 episodes of sonogram-proven intussusception were seen at the Department of Pediatrics at the Chiayi and Pingtung Christian Hospitals. Instead of a barium enema under radiological guidance, we performed hydrostatic reduction using a saline enema under sonographical guidance. The whole procedure was monitored and adequately controlled by real-time sonography. Thirty-two out of 35 episodes of intussusception were successfully reduced with no complications. The reduction rate was 91.4%. There were no abnormal findings in the intestines of those three patients who were operated on for unsuccessful reduction. The accessibility and safety of this new method of intussusception reduction makes it promising for the future.

Child↗
PubMed1992

A study of the comparative structure of guilt and shame in a Chinese society.

On the basis of previous theoretical and empirical analyses of the comparative structures of guilt and shame, the authors hypothesized that antecedent condition (personal inadequacy vs. moral norm violation), audience presence, and personal responsibility attribution would distinguish shame from guilt. Although the subject population was Hong Kong Chinese, evidence from previous studies suggests that the comparative structures of guilt and shame are quite similar across cultures. The subjects were asked to recall either a guilt or a shame incident, and their responses were then coded into the predictor variables. The results of the study indicated that guilt was most likely to emerge when individuals had violated a moral norm and held themselves responsible for their conduct. In contrast, shame emerged more frequently when subjects felt personally inadequate than when they had violated moral norms. Moreover, when a guilt incident was reported, and audience was rarely mentioned, whereas subjects who reported a shame incident would generally feel personally responsible and often mentioned being looked at or evaluated. However, neither personal responsibility nor the presence of an audience seemed to be essential for a person to experience shame.

Adult↗
PubMed1991

Effects of age, breast feeding, and household structure on Haemophilus influenzae type b disease risk and antibody acquisition in Alaskan Eskimos.

Invasive Haemophilus influenzae type b (Hib) disease occurs with unusually high incidence in Alaskan Eskimos. In 1983, the authors evaluated the unique susceptibility of the Yupik-speaking Eskimo population in southwest Alaska. A matched case-control design was used to assess the influence of age, breast feeding, and household composition on disease risk, with a historical cohort design to evaluate their effects on acquisition of Hib anticapsular antibody. The authors studied 103 cases with known invasive Hib disease that occurred at a mean age of 8.7 +/- 8.6 months; healthy controls were matched for age and village of residence. Living in extended families at the time of disease onset was significantly associated with Hib disease (p less than 0.04; odds ratio = 1.8; 95% confidence interval 0.87-3.25). The authors found that breast feeding was significantly less common among cases than controls (p less than 0.03; odds ratio = 0.53; 95% confidence interval 0.27-0.98). Although there was a positive correlation between age and acquired level of total anticapsular antibody (r = 0.59; p less than 0.0001), previous exposure to invasive Hib disease did not influence these levels. Household crowding and breast feeding also did not appear to affect Hib antibody acquisition.

Age Factors↗
PubMed1989

Attending coverage in academic emergency medicine: a national survey.

We surveyed the 66 accredited emergency medicine residency programs in the United States during 1986 on the issue of attending coverage. Responses were received from 411 residents and 288 faculty; this accounted for 42% of the residents and 56% of the faculty from the 56 responding programs. Seventy-three percent of emergency medicine residency programs had 24-hour attending coverage. According to residents, faculty from programs with 24-hour coverage spent a greater percentage of their shift doing primary patient care than faculty from programs without 24-hour coverage (35% vs 17%, respectively, P less than .0001), and a smaller percentage of their shift educating residents (21% vs 30%, respectively, P less than .0001). Ninety-five percent of faculty and 71% of residents thought that the quality of patient care was better when faculty were present in the ED (P less than .0001). Sixty-one percent of residents and 60% of faculty did not think that 24-hour attending coverage in academic emergency medicine should be mandated. The impact of night-time attending coverage in emergency medicine residency programs on patient care, resident education, and faculty development is unclear and minimally studied.

Emergency Medicine↗
PubMed1989

Reward allocation among Chinese high school students in Hong Kong.

The present study examined the effects of personality and performance on reward allocation. The subjects were 89 Chinese senior high school students in Hong Kong. The results showed that the subjects would take into consideration the recipient's personality when they allocated reward to a relatively low performer. Personality factors were irrelevant, however, in the allocation of reward to a relatively high performer. Moreover, the subjects judged an allocation decision as more unfair when the allocation was intended to be a punishment for a worker with relatively low performance and a desirable personality than when the allocation was intended to be a reward for a relatively high performer.

Adolescent↗
PubMed1989

Pathogenic effects of monocytopenia, granulocytopenia and dexamethasone on the course of experimental Pseudomonas aeruginosa endocarditis in rabbits.

Intravegetation host inflammatory cell function may play a role in the more salutary clinical outcomes in human right- vs. left-sided endocarditis. To study this in vivo, 90 rabbits with tricuspid Pseudomonas aeruginosa endocarditis received either no therapy (controls), nitrogen mustard (HN2) to induce combined granulocytopenia + monocytopenia, etoposide (VP-16-213) to induce selective monocytopenia, or dexamethasone. Intravegetation inflammatory cell influxes were scored on a semiquantitative histopathologic scale. In VP-16-213 and dexamethasone recipients and tricuspid endocarditis controls, gradual decreases in mean intravegetation bacterial densities were observed over a 13-day infection period; in contrast, HN2 treatment was associated with a significant increase in intravegetation bacterial densities by day 13 of infection (p less than 0.001 vs. other tricuspid endocarditis groups). Histopathologically, vegetations from untreated controls and dexamethasone recipients showed granulocyte influxes during infection, while HN2 treatment resulted in predominantly granulocyte depletion within infected tricuspid vegetations; VP-16-213 caused mononuclear cell depletion at this site. This study supports the concept that the granulocyte plays a critical role in modulating spontaneous endocardial clearances of bacteria in experimental tricuspid endocarditis.

Animals↗
PubMed1988

Haemophilus influenzae type b anticapsular antibody responses to PRP-pertussis and PRP-D vaccines in Alaska native infants.

To evaluate immune responses in Alaska Native infants at high risk for invasive Haemophilus influenzae type b (Hib) disease, we studied PRP-pertussis and PRP-D conjugate vaccines in this population relative to responses in white infants in California and New York. Infants were immunized at two, four, and six months of age (both vaccines). In the PRP-pertussis trial, there were no significant differences in antibody levels at any age between Alaska Native infants and infants from California. Only 50% of the infants had a twofold or greater antibody rise after three doses. In the PRP-D trial, antibody levels at two months of age (presumably maternally acquired) were significantly higher for Alaska Native infants compared with infants from New York (P = .002). There were no significant differences in antibody levels after any of the three doses. Among Alaska Native infants there was no significant difference in antibody response based upon degree of ethnic purity.

Alaska↗
PubMed1988

Developmental and metabolic regulation of the Drosophila melanogaster 3-hydroxy-3-methylglutaryl coenzyme A reductase.

The enzyme 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase in Drosophila melanogaster synthesizes mevalonate for the production of nonsterol isoprenoids, which are essential for growth and differentiation. To understand the regulation and developmental role of HMG CoA reductase, we cloned the D. melanogaster HMG CoA reductase gene. The nucleotide sequence of the Drosophila HMG CoA reductase was determined from genomic and cDNA clones. A 2,748-base-pair open reading frame encoded a polypeptide of 916 amino acids (Mr, 98,165) that was similar to the hamster HMG CoA reductase. The C-terminal region had 56% identical residues and the N-terminal region had 7 potential transmembrane domains with 32 to 60% identical residues. In hamster HMG CoA reductase, the membrane regions were essential for posttranslational regulation. Since the Drosophila enzyme is not regulated by sterols, the strong N-terminal similarity was surprising. Two HMG CoA reductase mRNA transcripts, approximately 3.2 and 4 kilobases, were differentially expressed throughout Drosophila development. Mevalonate-fed Schneider cells showed a parallel reduction of both enzyme activity and abundance of the 4-kilobase mRNA transcript.

Amino Acid Sequence↗
PubMed1988

Tricuspid valve endocarditis due to Staphylococcus aureus. Correlation of two-dimensional echocardiography with clinical outcome.

We studied 53 episodes (51 patients) of tricuspid valvular endocarditis caused by Staphylococcus aureus in a predominantly addicted population and correlated two-dimensional echocardiographic findings with clinical outcome. Thirty-eight episodes with (vs 15 episodes without) tricuspid vegetations on the two-dimensional echocardiogram were significantly associated with (1) longer duration of fever on therapy (mean of 12.3 days vs 6.8 days, respectively; p less than 0.005); and (2) higher frequency of increased right ventricular end-diastolic (RVED) dimension (25 of 38 cases [66 percent] vs two of 15 cases [13 percent], respectively; p less than 0.01). Only patients with increased RVED dimension (5/25; 20 percent) required tricuspid valvular surgery for prolonged fever or progressive right-sided heart failure (p less than 0.05 vs patients with normal RVED dimension). Tricuspid vegetations greater than 1.0 cm identified a subset of patients at increased risk for developing clinical right-sided heart failure during the active or convalescent phase of endocarditis (p less than 0.02 vs patients with tricuspid vegetations less than 1.0 cm). An unexpectedly high prevalence of asymptomatic prolapse of the mitral valve was observed in this population (23 of 53 episodes; 43 percent). Detection of tricuspid vegetations in patients with endocarditis due to S aureus is not a primary indication for early surgery, but identifies patients more likely to exhibit short-term and long-term complications of their infection.

Adult↗