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Biomedical subjects

F Wei

Publications and source records attributed to F Wei.

69 records · Page 4Linked to original sources
PubMed1996

In vitro effect of hemodilution on activated clotting time and high-dose thrombin time during cardiopulmonary bypass.

BACKGROUND: Extreme dilution of clotting factors, as may occur during pediatric or neonatal cardiopulmonary bypass, often leads to inadequate monitoring of anticoagulation with activated clotting time (ACT). In this study we postulate that the high-dose thrombin time (HiTT) is less influenced by extreme dilution of clotting factors because it stimulates clotting through the common pathway. METHODS: Heparinized prebypass blood was obtained from 30 adult cardiac surgical patients and was diluted in a laboratory setting with saline solution to mimic the clinical clear prime solution (group I; n = 10), with saline solution containing similar heparin as in the prebypass blood (group II; n = 10), and with fresh frozen plasma to substitute clotting factors in the diluted blood (group III; n = 10). Blood was diluted to four different degrees: a control without dilution, 25%, 50%, and 75% dilution. The ACT and HiTT were measured and compared. RESULTS: In group I, significant prolongation of ACT was observed in blood diluted to 75% as compared with the nondiluted blood (p < 0.01). In contrast, HiTT was not prolonged at any degree of dilution but reduced proportionally to dilution up to 75%, reflecting the concomitant reduction of heparin. In group II, ACT increased at 25% dilution (p < 0.01) whereas HiTT increased at 50% dilution (p < 0.01). In group III, no prolongation of ACT or HiTT was found in any degree of dilution. Furthermore, adding fibrinogen to the diluted blood (n = 4) did not cause ACT to recover at 75% dilution, suggesting that dilution of other factors in the early clotting cascade rather than fibrinogen alone increases ACT. CONCLUSIONS: These results imply that when blood is extremely diluted during cardiopulmonary bypass with a clear prime without substituted clotting factors, HiTT is a better test than ACT for anticoagulation monitoring.

Adult↗
PubMed1996

[Chemical anatomy of the nociceptive transmission and modulation in the spinal dorsal horn].

The present study had been made to study the distribution and synaptic characteristics of primary afferent C fibers and the normal chemical architecture of some neurotransmitters in spinal dorsal horn. The changes of the neurotransmitters with acute nociceptive stimulation were measured quantitatively. We demonstrated the synaptic relationships among primary afferent C fibers, inhibitory interneurons and nociceptive dorsal horn neurons and discussed their function in nociceptive transmission and modulation. These results provide evidence that acute pain evolved co-release of substance P and glutamate from C-fiber terminals may constitute a driving force for secondary activation of ascending projection neurons or of internal GABAergic antinoceciptive system directly via their receptors in the dorsal horn of the spinal cord.

Animals↗
PubMed1995

Effect of TENS-like stimulation on C afferent-induced c-fos expression in the rat spinal cord.

Transcutaneous electrical nerve stimulation (TENS) has been widely used to relieve pain. This study examined the effect of TENS-like stimulation on primary C afferent-induced c-fos expression in the rat spinal dorsal horn. Fos-like immunoreactivity (FLI) evoked by excitation of C fibres of the tibial nerve was found ipsilaterally in laminae I-VIII and X of the spinal cord. The greatest number of FLI neurones was located in the medial half of laminae I-II0 and V at L5. When TENS-like stimulation (100 Hz) was applied proximally to the same tibial nerve, the number of FLI neurones by C afferents was reduced remarkably in ipsilateral laminae I-II0 and IV-VII. The results suggest that TENS stimulation-induced reduction of c-fos expression may reflect an inhibition of spinal nociception.

Afferent Pathways↗
PubMed1995

Are PRO discharge screens associated with postdischarge adverse outcomes?

OBJECTIVE: We evaluate whether patient outcomes may be affected by possible errors in care at discharge as assessed by Peer Review Organizations (PROs). DATA SOURCES/STUDY SETTING: The three data sources for the study were (1) the generic screen results of a 3 percent random sample of Medicare beneficiaries age 65 years or older who were admitted to California hospitals between 1 July 1987 and 30 June 1988 (n = 20,136 patients); (2) the 1987 and 1988 California Medicare Provided Analysis and Review (MEDPAR) data files; and (3) the American Hospital Association (AHA) 1988 Annual Survey of Hospitals. STUDY DESIGN: Multivariate logistic regression analysis was used to evaluate the association between the results of generic discharge administered by the PROs and two patient outcomes: mortality and readmission within 30 days. The analysis was adjusted for other patient characteristics recorded on the uniform discharge abstract. PRINCIPAL FINDINGS: Four discharge screens indicated an increased risk of an adverse outcome-absence of documentation of discharge planning, elevated temperature, abnormal pulse, and unaddressed abnormal test results at discharge. The other three discharge screens examined-abnormal blood pressure, IV fluids or drugs, and wound drainage before discharge-were unrelated to postdischarge adverse outcomes. CONCLUSIONS: Generic discharge screens based on inadequate discharge planning, abnormal pulse, increased temperature, or unaddressed abnormal tests may be important indicators of substandard care. Other discharge screens apparently do not detect errors in care associated with major consequences for patients.

Aged↗
PubMed1995

[Excision of mid-lower rectal carcinoma through abdomen and anogenital space].

28 men with male mid and lower rectal carcinoma were treated by dissecting sigmoid colon and rectum in the abdomen through the anogenital space, which refers to the potential coronoid space located between the deep transverse perineal muscles and anal sphincter muscles. The rectal segment was pulled out through the anogenital space to accomplish resection and anastomosis outside the pelvic cavity. Follow-up for 9-57 months showed that 26 cases (92.9%) survived without recurrence of carcinoma and 1 had local recurrence. The advantages of the procedure include clear exploration, minimal trauma, super-lower anastomoses under direct vision, good recovery of defecating function, and less contamination of pelviccavity.

Adenocarcinoma↗
PubMed1995

[A study of relation of cardiac function and deformity degree in children with pectus excavatum].

40 children with pectus excavatum were divided into subgroups according to the FI (> 0.2 or < 0.2) and underwent M-ME examination for their cardiac function. 28 of 40 patients had their cardiac function and thoracic index re-examined after the operation. The results showed the cardiac function of children with pectus excavatum was damaged as FI of the patients was less than 0.2 and their cardiac function was getting well as their thoracic index improved.

Adolescent↗
PubMed1994

Neurobehavioral effects of phenytoin and carbamazepine in patients recovering from brain trauma: a comparative study.

OBJECTIVE: To compare the effects of prophylactic anticonvulsant use of phenytoin and carbamazepine on the cognitive and emotional status of the patient after brain injury. DESIGN: Double-blind, placebo-controlled study with assessments before and after withdrawal from drug treatment. SETTING: Patients had been initially treated by neurosurgeons at a university hospital and were followed up during the study on an outpatient basis. PATIENTS: Forty of 64 patients receiving phenytoin and 42 of 127 patients receiving carbamazepine from 6 to 44 months for seizure prophylaxis after brain injury met study criteria and were assigned to continue or discontinue treatment. Groups were balanced for age, sex, race, weight, intelligence, type of injury, duration of therapy, and drug plasma concentration at screening. INTERVENTION: A battery of neuropsychological tests was administered twice during a 4-week baseline period, at the end of a 4- to 5-week period of continued drug treatment or placebo, and after 4 weeks of not receiving medication. MAIN OUTCOME MEASURES: Attention and concentration, psychomotor speed, memory, verbal fluency, and emotional state. RESULTS: No significant differences were found in the performance of patients in medication and placebo groups for either drug at the end of the placebo phase. Patients in the combined groups showed significant improvement (P < .01) on several measures of motor and speeded performance following cessation of drug treatment. Multivariate analyses showed additional differences between phenytoin and carbamazepine and also suggested a significant practice effect on some measures used. CONCLUSIONS: Both phenytoin and carbamazepine seem to have negative effects on cognitive performance, particularly on tasks with significant motor and speed components. Practice effects were noted and may account for much of the improvement when patients stopped taking the drugs. Overall effects of the drugs were small and of limited clinical significance, but differences among subjects were noted that may affect selection of a particular drug for the individual patient.

Adult↗
PubMed1990

Comparison of corneal epithelial wound healing rates in scrape vs. lamellar keratectomy injury.

Previous in vivo studies evaluating the effects of growth factors on epithelial regeneration have used the scrape injury model in rabbit eyes. Since growth factors act principally on the mitotic activity of regenerating cells, the rapid wound closure rates following scrape injury may not adequately access the effects of these agents on epithelial repair. In this study, we evaluated the rates of wound healing following scrape (8.6 mm) and lamellar keratectomy (8.6 mm) injury in 25 albino rabbits. Eyes were left untreated or received daily application (two to three times) of (a) Tears Naturale II, (b) 50 mM Tris/NaCl, and (c) commercial vehicle for EGF. Eyes were evaluated daily by fluorescein staining with Ophthalmic Fluoro-Strips followed by clinical photography. The area of staining was quantitated by computer-assisted planimetry and rates calculated by linear regression analysis. Eyes receiving scrape injuries epithelialized by 3 days following surgery. Rates of wound closure in two separate groups (six eyes each) were 25.83 mm2/day (r = 0.96) and 29.56 mm2/day 9r = 0.97). Lamellar keratectomy injuries epithelialized by 7 to 8 days, which is substantially longer than that observed for scrape injuries. Rates of wound healing in two separate untreated groups (8 and 10 eyes) were 10.88 mm2/day (r = 0.95) and 9.00 mm2/day (r = 0.93), respectively, which were not significantly different. Analysis of variance comparing rates of wound closure indicated that lamellar keratectomy injuries heal at a significantly slower rate when compared to scrape injury (p less than 0.0005).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Evidence for t-tubular conduction failure in frog skeletal muscle induced by elevated extracellular calcium concentration.

In order to investigate the mechanism by which elevated extracellular calcium ions decrease tetanus tension in frog skeletal muscle, we made mechanical, electrophysiological and photographic measurements on single fibres or small bundles of fibres. Three lines of evidence point to t-tubular conduction failure as the primary mechanism of action of high calcium. They are a decrease in amplitude of the late afterpotential, attenuation or elimination of the notch and hump configuration of the early afterpotential, and the appearance of wavy myofibrils in the axial core of fibres during tetanus. These effects are fully reversible and are shared by other bivalent cations. High calcium concentration causes a change in the time course of the early afterpotential but does not alter the passive cell membrane characteristics, as reflected by the time course of decay of applied hyperpolarizing pulses.

Action Potentials↗
PubMed1987

Venous bridge used in free flap transfer for the lower leg in the presence of venous hypertension: a case report.

Reconstruction with free flaps for the lower leg in the presence of venous thrombosis or venous hypertension has a high risk of failure. We describe the use of the contralateral leg for venous drainage through a pedicled skin bridge containing a tributary of the long saphenous vein. The recipient artery was a main artery of the ipsilateral leg. Two weeks later, once there was a well-established venous communication between flap and recipient site, the venous bridge was divided. Because the arterial inflow to the flap was not interrupted by the division of the skin bridge, the flap has good viability and good resistance to infection or ulceration 3 years later.

Adult↗
PubMedDate not supplied

Pharmaceutical care for patients with chronic conditions.

OBJECTIVE: To assess factors associated with participation in pharmaceutical care and the benefits of participation--in terms of amount of information about medications, administration of medications, and awareness of side effects. DESIGN: Quasi-experimental design, with a control group. Medication Survey, administered 6 months after pharmaceutical care intervention to participants, refusers, and controls. Logistic regression analyses. SETTING: Three staff clinic pharmacies and three contract clinic pharmacies affiliated with a health maintenance organization (HMO). PATIENTS AND OTHER PARTICIPANTS: Patients with chronic health conditions (asthma, chronic obstructive pulmonary disease, or heart disease) enrolled at six intervention sites, identified through the HMO's electronic pharmacy database. Control sample with the same chronic health conditions, without access to pharmaceutical care (n = 210 participants, 162 refusers, and 368 controls; overall adjusted response rate = 72%). INTERVENTION: Pharmaceutical care, in the form of a comprehensive drug therapy management program. MAIN OUTCOME MEASURES: Predictors of participation, amount of information about medications, use of reminder methods, and awareness of side effects. RESULTS: The following variables were significantly associated with the probability of participating in pharmaceutical care (P < .05): number of medications, employment, income, health status, education, and living situation. Participants were more likely than controls to say they received "a lot of information" from their pharmacist about all aspects of medications (odds ratio [OR], 1.75 to 2.68). Participants were more likely to report leaving their medication container in a visible place and using two or more reminder methods (OR, 1.87 to 1.48). There were no significant differences in the probability of missing doses. Participants were more likely to report experiencing "symptoms or problems" associated with prescription medications (OR, 1.81). CONCLUSION: Pharmaceutical care appears to increase the information given to patients about medications, promote more effective self-administration of medications by encouraging patients to use systematic reminders, and increase awareness of medication side effects.

Chronic Disease↗
PubMedDate not supplied

Long-term ambient air pollution levels in four Chinese cities: inter-city and intra-city concentration gradients for epidemiological studies.

The field data collection of an air pollution epidemiologic study was carried out from 1993 to 1996 in four Chinese cities of Lanzhou, Chongqing, Wuhan, and Guangzhou. In each city, an urban district and a suburban district were selected. Ambient concentrations of total suspended particles (TSP), size-fractionated particulate matter including PM2.5, PM2.5-10, and PM10, sulfur dioxide (SO2), and oxides of nitrogen (NOx) were measured in these districts. The results indicate the presence of wide inter-city and intra-city gradients in long-term ambient levels of these measured pollutants. Across the eight districts, the 1993-1996 4-year means of TSP, SO2, and NOx ranged from 198 to 659 microg/m3, from 14.6 to 331 microg/m3, and from 31.5 to 239 microg/m3, respectively, and the 1995-1996 2-year means of PM2.5, PM2.5-10, and PM10 ranged from 51.5 to 142 microg/m3, from 29.2 to 107 microg/m3, and from 80.7 to 232 microg/m3, respectively. These pollution ranges substantially extended the upper end of the pollution ranges of previous air pollution epidemiologic studies conducted in North America and Europe. In each district, significant correlations among the measured pollutants were observed for daily concentrations. However, the gradient patterns in long-term means of different pollutants were different across the eight districts. (e.g., PM2.5-10 and TSP were highest in the Lanzhou urban district, PM2.5 and PM10 were highest in the Guangzhou urban district, SO2 was highest in the Chongqing urban district, and NOx was highest in the Guangzhou urban district). In general, seasonal variations were present in the ambient concentrations with high levels often occurring in winter months. The eight districts may be classified into four district clusters based on integrated levels of all measured pollutants. These features of the ambient air pollution have important implications for epidemiological studies and may provide unique opportunities to study exposure-effects relationships in the four Chinese cities.

Air Pollutants↗
PubMedDate not supplied

A CQI intervention to change the care of depression: a controlled study.

CONTEXT: Although new strategies for managing depression in primary care (e.g., nurse telephone calls, collaborative care) have been shown to be effective, no models are available for their systematic implementation in the "real world." OBJECTIVE: To test whether a continuous quality improvement (CQI) intervention could be used to implement systems in primary care clinics to improve the care and outcomes for patients diagnosed with depression. DESIGN: Before-after study with concurrent controls. INTERVENTION: A multidisciplinary team from the three intervention clinics developed and implemented a graded set of five care management options, ranging from watchful waiting (nurse telephone call in 4 to 6 weeks) to mental health management, which clinicians could order for their patients with depression. SETTING: 9 primary care clinics in greater Minneapolis-St. Paul, Minnesota. PATIENTS: Outpatients 18 years of age and older whose primary care clinic visit included an International Classification of Diseases, 9th revision, code for depression and who completed baseline and 3-month follow-up surveys before and after the intervention. MAIN OUTCOME MEASURES: Measures of process of care (follow-up depression visits to physician, mental health visits, follow-up telephone calls) and outcomes of care (improved depression symptoms over 3 months, satisfaction with care). RESULTS: Although the CQI team appeared to function well, only 30 of the 257 patients identified from depression-coded visits for this study were referred to the new system during the 3-month evaluation period. In both the intervention and control clinics, follow-up visits, mental health referrals, and follow-up telephone calls did not improve significantly from the preintervention levels of about 0.5 for a primary care visit, 0.4 for a mental health visit, or 0.1 for a follow-up phone call per person. The same was true of patient outcomes: The proportion of patients in the intervention and control clinics who had improved depression symptoms and those who were very satisfied with their depression care did not change significantly from the preintervention levels of 43% and 26%, respectively. CONCLUSIONS: Our attempt to improve the primary care management of depression failed because physicians used the new order system so infrequently. Whether a greater leadership commitment to change or a different improvement process would alter our findings is an open question.

Adolescent↗
PubMedDate not supplied

A regional integrated information system to assure maternal-child health services: a progress report.

Priorities for improving the health of our nation include rebuilding the public health infrastructure through increasing assessment, policy development, and assurance capacities in our communities. Capacity building necessitates formalizing and strengthening public health practice linkages to achieve Year 2000 objectives. Determining progress in achieving objectives requires development of public health infrastructure surveillance and data system capabilities. The Tracking Center of Tracking and Outreach Program for St. Louis (TOPS), through unique collaboration among academic and practice partners, laid the foundation for a Regional Integrated Information System (RIIS) by developing a centralized maternal-child health data base for prenatal and pediatric care providers. The RIIS model provides an example of a capacity building system designed to provide public health surveillance, assessment, planning, and evaluation capabilities. Medical Subject Headings (MeSH): health information systems, prenatal care, immunization, maternal-child health care, public health surveillance.

Child↗