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Lee ML. Recognition of Berry syndrome in a 4-day-old neonate by echocardiography and transvenous angiocardiography. Int J Cardiol 1999; 71:93-5. [PMID: 10522572 DOI: 10.1016/s0167-5273(99)00100-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Choo PW, Rand CS, Inui TS, Lee ML, Cain E, Cordeiro-Breault M, Canning C, Platt R. Validation of patient reports, automated pharmacy records, and pill counts with electronic monitoring of adherence to antihypertensive therapy. Med Care 1999; 37:846-57. [PMID: 10493464 DOI: 10.1097/00005650-199909000-00002] [Citation(s) in RCA: 432] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OBJECTIVES To evaluate the validity of patient report, pharmacy dispensing records, and pill counts as measures of antihypertensive adherence using electronic monitoring as the validation standard. METHODS The study was conducted among 286 members of Harvard Pilgrim Health Care, a managed care organization, who were at least 18 years of age, on monotherapy for hypertension, and had prescription drug coverage. Prescription refill adherence during the 12 months before enrollment was determined from their automated pharmacy dispensing records. Participants were interviewed about their medication adherence before and after a 3-month electronic monitoring period during which pill counts were also performed. Adherence to both recommended number and timing of doses was estimated from electronic monitoring data. Data analysis was based on statistical correlation and analysis of variance. RESULTS Electronic adherence monitoring revealed that the proportion of prescribed doses consumed was higher (0.92) than the proportion of doses taken on time (0.63). The correlation between adherence to quantity and timing of doses was 0.32. Concurrent pill counts and earlier refilling patterns were moderately correlated with electronic monitoring (pill count: r = .52 with quantity and r = .17 with timing; refill adherence r = .32 with quantity and r = .22 with timing). There was considerable misclassification of adherence reported by patients, although nonadherence was generally accurately reported. CONCLUSIONS Deviation from recommended timing of doses appears to be greater than from prescribed number of doses. Pharmacy dispensing records demonstrate predictive validity as measures of cumulative exposure and gaps in medication supply. Adherence levels determined from pill counts and pharmacy dispensing records correlate more closely with quantity than with timing of doses. Nonadherence reported by patients can serve as a qualitative indicator and predictor of reduced adherence.
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Yong JC, Yun SH, Lee ML, Kim BY. Frequency-division-multiplexed polarimetric fiber laser current-sensor array. OPTICS LETTERS 1999; 24:1097-1099. [PMID: 18073951 DOI: 10.1364/ol.24.001097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We demonstrate a novel frequency-domain-multiplexing technique for implementing polarimetric fiber laser current sensors. Each sensor operates at a different polarization-mode beat frequency that is modulated in response to applied electric current. A bank of bandpass filters can be used to separate signals from different sensors. A simple frequency-demodulation technique based on a phase-locked loop is used for signal processing.
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Chernof BA, Sherman SE, Lanto AB, Lee ML, Yano EM, Rubenstein LV. Health habit counseling amidst competing demands: effects of patient health habits and visit characteristics. Med Care 1999; 37:738-47. [PMID: 10448717 DOI: 10.1097/00005650-199908000-00004] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE This study assesses the effects of competing demands, such as poor health habits or new medical problems, on health-habit counseling during a primary care visit. METHODS We surveyed a consecutive sample of 1,259 patients visiting primary care clinicians at an academic VA medical center. Before the visit, patients reported their health status, health habits, and sociodemographics; immediately after the visit, patients reported reasons for the visit and whether they had been counseled about specific health habits. We scored visit acuity ranging from visits for unscheduled walk-in care or new medical problems to scheduled visits for check-ups or old problems. We defined counseling "triggers" as clinical indications for counseling about particular health habits (e.g., smoking). We developed a logistic model predicting primary care provider counseling during a visit. RESULTS Over two-thirds of patients (68.9%) received some health habit counseling. Controlling for other independent variables, patients with more triggers were more likely to report being counseled. Counseling rates went up as visit acuity went down; patients with the lowest visit acuity having 67% greater odds of being counseled than patients with the highest visit acuity. CONCLUSIONS Physicians set priorities for health-habit counseling during a visit based on patients' health habit problems or triggers; whether the visit is scheduled or walk-in; and whether the patient has new or acute problems. Future research about primary care performance of health habit counseling should account for these patient and visit characteristics, and prevention-oriented health care organizations should ensure access to scheduled "check-up" visits.
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Abstract
BACKGROUND An earlier retrospective review of records of over 500 remunerated donors participating in plasmapheresis programs at various levels of frequency for 10 or more years showed that there were no significant differences in mean values for total protein, microhematocrit, body weight, and individual serum proteins, regardless of the number of annualized donations for each of four frequency groups. Although these data demonstrated that donors undergoing serial plasmapheresis for 10 or more years were able to successfully continue in such programs, the review did not include information relative to individuals who had discontinued their participation. The current study investigated reasons that donors drop out of plasmapheresis programs. STUDY DESIGN AND METHODS Donors who had successfully undergone plasmapheresis at least 20 times within a recent 6-month period but who had failed to appear for at least 30 days subsequent to their last donation were defined as potential subjects for the study. Staff members at the participating center contacted the donors, inviting them to return to the center to participate in a survey. Donors were also asked for a blood sample upon their arrival at the plasma center; samples were tested for total and various serum proteins. RESULTS A total of 409 eligible subjects appeared at the centers for the survey, and 375 blood samples were analyzed for proteins. Survey responses indicated that the predominant reasons for an end to participation were socioeconomic in nature. Serum protein findings were compared to the most recent results obtained while the donors were active in the plasmapheresis program. Slightly higher mean serum protein findings were seen for samples collected on the survey date. CONCLUSION A review of the aggregate responses obtained in the survey indicates that the predominant reasons that donors ceased to participate were not health-related: the remuneration was no longer needed, and work schedule conflicts, time constraints, and relocation were frequently cited.
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Chiu IS, Wu SJ, Lee ML. One-stage repair of interrupted aortic arch and aortopulmonary window with an autologous arterial flap. J Card Surg 1999; 14:306-9. [PMID: 10874618 DOI: 10.1111/j.1540-8191.1999.tb00999.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Interrupted aortic arch associated with an aortopulmonary window is a rare congenital malformation that requires an early diagnosis and surgical treatment to avoid irreversible pulmonary vascular changes. We describe herein successful one-stage repair in a neonate without the use of pericardium or other prosthetic material. Use of a transaortic approach permitted both accurate planning of the appropriate size of pulmonary trunk flap and also facilitated easy repair of the aortopulmonary septal defect. The growth potential of both great arteries was optimized.
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Chuang HY, Lee ML, Chao KY, Wang JD, Hu H. Relationship of blood lead levels to personal hygiene habits in lead battery workers: Taiwan, 1991-1997. Am J Ind Med 1999; 35:595-603. [PMID: 10332513 DOI: 10.1002/(sici)1097-0274(199906)35:6<595::aid-ajim7>3.0.co;2-5] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND The blood lead concentrations of workers in lead battery factories are more than 4 times higher than those of the general population in Taiwan. Therefore, efforts are needed to reduce lead exposure in this high-risk population. A health promotion program on personal habits that reduce lead exposure has been carried out in a lead battery factory since 1991. This study investigated the longitudinal relationship of workers' blood lead concentrations and personal hygiene habits from 1991 through 1997. METHODS In each of the 7 years of the study, occupational physicians questioned workers regarding nine personal hygiene items, personal information, and medical history before their annual health examination. The relationship between blood lead concentrations and personal hygiene habits was analyzed by longitudinal multiple regression in a mixed effect model with adjustment for potential confounders. In addition, the risk ratio of a blood lead concentration exceeding 40 micrograms/dL in men and 30 micrograms/dL in women (the action levels set by the Department of Health, Taiwan) was estimated by generalized estimating equations. RESULTS Blood lead levels decreased significantly in the first 5 years of the study. The personal habits most closely related to blood lead concentrations were smoking at work sites (estimated coefficient = 3.13, P < 0.001), and eating at work sites (estimated coefficient = 1.38, P = 0.069). The risk ratio for workers with both these habits exceeding the action level of blood lead was 2.93 (95% CI 1.27-6.77). Difference in job titles, however, accounted for a major portion of the variance in blood lead. For example, working in "pasting" and "plate-cutting" was associated with blood lead elevations > 20 micrograms/dL in comparison to the "low- or no-exposure jobs." CONCLUSIONS Health promotion programs can decrease exposure of lead workers; reducing the practices of smoking and eating at work sites should be the core of such programs. However, a major reduction in lead exposure for some jobs (e.g., "pasting" and "plate cutting") in lead battery factories in Taiwan is unlikely to occur without major engineering changes.
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Platt R, Adelson-Mitty J, Weissman L, Zaleznik D, Lee ML, Baker CJ. Resource utilization associated with initial hospital stays complicated by early onset group B streptococcal disease. Pediatr Infect Dis J 1999; 18:529-33. [PMID: 10391183 DOI: 10.1097/00006454-199906000-00010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
BACKGROUND The epidemiology of early onset neonatal group B streptococcal (GBS) disease has changed appreciably, but there are no recent assessments of the in-hospital resource utilization it incurs. STUDY DESIGN We performed a retrospective cohort study of infants delivered from 1987 through 1995 at Massachusetts' largest obstetrics hospital. A matched cohort design was used to assess care occurring after transfer to another acute care hospital. RESULTS There were 135 cases of early onset neonatal GBS infection complicating 85,062 deliveries (1.6/1,000 births) in 9 years, with a substantial decline beginning in 1994, when maternal intrapartum chemoprophylaxis was widely introduced. Most (73%) infants had birth weights of 2500 g or more; 93% survived. Overall both the median and mean lengths of stay were 8 days longer for infants with GBS disease than for those without this infection (P < 0.001). Total hospital charges for neonates with GBS disease also were higher, with the difference in medians of $5323 and in means of $10,004 (P < 0.001). Differences were greatest among >2500-g birth weight infants; no excess was evident for infants with birth weights of < 1500 g. CONCLUSION There was a substantial excess length of stay and charges associated with early onset neonatal GBS disease, although this was less than previously reported.
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Chugani DC, Sundram BS, Behen M, Lee ML, Moore GJ. Evidence of altered energy metabolism in autistic children. Prog Neuropsychopharmacol Biol Psychiatry 1999; 23:635-41. [PMID: 10390722 DOI: 10.1016/s0278-5846(99)00022-6] [Citation(s) in RCA: 127] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
1. In this pilot study, the authors investigated the hypotheses there are increased concentrations of lactate in brain and plasma and reduced brain concentrations of N-acetyl-aspartate (NAA) in autistic children. 2. NAA and lactate levels in the frontal lobe, temporal lobe and the cerebellum of 9 autistic children were compared to 5 sibling controls using MRS. Plasma lactate levels were measured in 15 autistic children compared to 15 children with epilepsy. 3. Preliminary results show lower levels of NAA cerebellum in autistic children (p = 0.043). Lactate was detected in the frontal lobe in one autistic boy, but was not detected any of the other autistic subjects or siblings. 4. Plasma lactate levels were higher in the 15 autistic children compared to 15 children with epilepsy (p = 0.0003). 5. Higher plasma lactate in the autistic group is consistent with metabolic changes in some autistic children. The findings of altered brain NAA and lactate in autistic children suggest that MRS may be useful characterizing regional neurochemical and metabolic abnormalities in autistic children.
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Lee ML, DuBois A, Ross RA, Onderdonk AB. Nonlinear models for in vitro kill kinetics of antibiotics. J Biopharm Stat 1999; 9:271-7. [PMID: 10379693 DOI: 10.1081/bip-100101176] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
In this study, we developed nonlinear regression models to analyze the data generated from an in vitro continuous culture system to assess the kinetics of metronidazole and trovafloxacin in inhibiting the growth of Bacteroides fragilis. The model includes parameters describing the initial shock effect of an antibiotic pulse, the overall antibiotic wash-out rate from the system, and the long-term toxicity of the antibiotic in the environment after one pulse and before the next pulse.
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Tsaih SW, Schwartz J, Lee ML, Amarasiriwardena C, Aro A, Sparrow D, Hu H. The independent contribution of bone and erythrocyte lead to urinary lead among middle-aged and elderly men: the normative aging study. ENVIRONMENTAL HEALTH PERSPECTIVES 1999; 107:391-6. [PMID: 10210695 PMCID: PMC1566410 DOI: 10.1289/ehp.99107391] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Plasma is the component of blood from which lead is free to cross cell membranes and cause organ toxicity. Plasma lead levels, however, are extremely low and difficult to measure. Urinary lead originates from plasma lead that has been filtered at the glomerular level; thus, urinary lead adjusted for glomerular filtration rate serves as a proxy for plasma lead levels. In this investigation we examined the interrelationships of lead levels in whole blood corrected by hematocrit [i.e., erythrocyte lead (EPb)], trabecular bone (TBoPb), cortical bone (CBoPb), and urine excreted over 24 hr (UPb); all samples were obtained from 71 middle-aged and elderly men with no known occupational lead exposures. Lead was measured by graphite furnace atomic absorption spectroscopy (blood), K-X-ray fluorescence (bone), and inductively coupled plasma mass spectroscopy (urine). Lead levels were generally low, with mean EPb, TBoPb, and CBoPb values of 13.8, 31.1, and 21.7 microg/g, respectively, and a median UPb value of 6.15 microg/day. In generalized additive models adjusted for body weight and creatinine clearance rate, both EPb and bone lead variables remained independently and significantly associated with UPb. This finding suggests that bone influences plasma lead in a manner that is independent of the influence of erythrocytic lead on plasma lead. Thus, the superiority of bone lead over blood lead in predicting some chronic forms of toxicity may be mediated through bone's influence on plasma lead. In addition, this study suggests that measurement of urinary lead might be useful as a proxy for plasma lead levels in studies of lead toxicity.
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Lee ML, Chaou WT, Wang JK. Transarterial occlusion of patent ductus arteriosus with Gianturco coils in pediatric patients: a preliminary result in central Taiwan. Int J Cardiol 1999; 69:57-63. [PMID: 10362373 DOI: 10.1016/s0167-5273(99)00009-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
OBJECTIVE We wish to present the preliminary result of transarterial occlusion of patent ductus arteriosus (PDA) with Gianturco coils in pediatric patients in central Taiwan. MATERIALS AND METHODS We attempted occlusion of PDA with Gianturco coils in a total of 26 consecutive patients, 13 infants and 13 children, 23 female and three male, between July 1 1997 to September 30 1998. Median patient age was 2.57 years (from 0.25 to 14.02 years old). Median patient weight was 10.8 kg (4.0 to 36.0 kg). Premature babies with PDA, full-term babies who were less than three months old and patients who had other congenital heart disease were not included in this study. All PDAs were approached transarterially from the femoral artery. Coils were selected to provide a helical diameter that was twice or more the minimum ductus diameter and a length approximating five loops. In five patients who had a PDA diameter > or =3.5 mm, we used a snare technique to assist coil delivery beforehand, and to test coil stability, or to retrieve coil that had migrated to the pulmonary artery afterwards. Physical auscultation, chest radiographs and echocardiography with color Doppler were done in all patients within 24 h, and one, two, three, six and 12 months after coil occlusion. RESULTS The median ductus minimum diameter was 2.3 mm (range, 1.0 to 4.7 mm). Fifteen patients had the megaphone type (type A), four had the window type (type B), five had the tubular type (type C), one had the aneurysmal type (type D) and one had the elongated conical type (type E). Twenty-one patients underwent single coil occlusion and five had multiple coils occlusion. Twenty-one patients had immediate angiographic closure of the ductus and disappearance of heart murmur at 15 min after the procedure. Dark-brown urine (hemoglobinuria) was found in one patient, 10 h after the first procedure, due to a mild residual ductal shunt. Two more coils were implanted in a second procedure that was performed within 24 h, and the ductus was completely occluded. The dark-brown urine regressed. At one month follow-up, four patients had mild residual ductal shunts, which were completely occluded by one more coil in three patients and by two more coils in the other patient. Malpositioned coils were deployed in five patients immediately after the procedure. In total, the closure rate at 15 min, within 24 h, and at one, two, three, six and 12 months were 81, 85, 85, 100, 100, 100 and 100%, respectively. In one year of follow-up, there was no instance of coil migration, ductus reopening or stenosis of the left pulmonary artery. CONCLUSIONS Transarterial occlusion of PDA, with a Gianturco coil having approximately five loops, can be effectively achieved in patients with a minimum ductus diameter up to 4.7 mm. In patients with a ductus of more than 3.5 mm, the snare-assisted technique was employed advantageously to control coil delivery with accuracy and stability. Coil malposition or migration can be easily retrieved using a 10-mm Nitnol snare catheter. Hemoglobinuria, due to intravascular hemolysis, may regress within 24 h after the second attempt at coil implantation.
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Smith PA, Bowerbank CR, Savage PB, Drown DB, Lee ML, Alexander W, Jederberg WW, Still K. Conjugation of 7-oxodehydroabietic acid to lysine, a haptenation mechanism for an oxidized resin acid with dermal sensitizing properties. APPLIED OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 1999; 14:171-6. [PMID: 10453631 DOI: 10.1080/104732299303133] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
This article explores protein conjugation of 7-oxodehydroabietic acid, a resin acid found in both aerosol from soldering with rosin flux and in rosin solids. In a murine model, conjugation (haptenation) of resin acids to proteins is required to generate antibodies against rosin. Hydroperoxy resin acids are dermal sensitizers, with haptenation thought to occur via radical mechanisms. Dermal sensitization to 7-oxodehydroabietic acid has been observed, although no radical haptenation mechanism has been proposed to explain the sensitizing properties of this compound. Conjugation of L-lysine to 7-oxodehydroabietic acid was predicted, with a Schiff base (or imine) linkage formed between C-7 of the resin acid and a free amino group of lysine. Fast atom bombardment mass spectrometry provided evidence of the conjugate; a small peak was seen for the conjugate (M+H)+ ion in aqueous ethanol with 20 mM concentrations of the free resin and amino acids. A larger conjugate peak was observed with addition of tertiary amine as a mild basic catalyst, and the intensity of the conjugate peak exceeded that of the precursors upon replacement of the ethanol with benzene. Resin acids accumulate in the plasma membrane, a non-aqueous environment apparently conducive to conjugation of 7-oxodehydroabietic acid with lysine side chains of membrane proteins. The result would be dehydroabietic acid covalently bound to protein, which could lead to interaction with immune cells having resin acid specificity. The haptenation mechanism presented may be involved in allergic contact dermatitis and occupational asthma observed from exposure to resin acid solids and aerosols. As sampling and analytical methods have been previously demonstrated for 7-oxodehydroabietic acid, this compound may be a useful exposure marker with relevance to negative health effects such as occupational asthma.
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Lee ML, Rosner BA, Weiss ST. Relationship of blood pressure to cardiovascular death: the effects of pulse pressure in the elderly. Ann Epidemiol 1999; 9:101-7. [PMID: 10037553 DOI: 10.1016/s1047-2797(98)00034-9] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE To investigate the relationship of systolic and diastolic blood pressure to fatal myocardial infarction, fatal stroke and other death related to cardiovascular diseases (CVD). METHODS The study was based on a prospective longitudinal study conducted by the Veterans Administration at the Boston Outpatient Clinic. Participants are male volunteers from the greater Boston area. Main outcome measures are fatal myocardial infarction, fatal stroke and other deaths related to cardiovascular diseases. The method of pooled logistic regression was used for statistical analysis. RESULTS For younger men (age 21-59), after adjusting for effects of other risk factors, when systolic and diastolic blood pressure were considered separately, SBP was predictive of cardiovascular death (SBP: RR = 1.23; 95% CI = (1.05, 1.45) per 10 mmHg of increase), and DBP showed a nonsignificant positive trend in relation to cardiovascular death (DBP: RR = 1.27; 95% CI = (0.95, 1.69) per 10 mmHg of increase). For older men (age 60-85), when SBP and DBP were considered separately, SBP (RR = 1.26; 95% CI = (1.02, 1.55) per 15 mmHg of increase) was directly related, but DBP (RR = 1.05; 95% CI = (0.83, 1.32) per 8 mmHg of increase) was not related to cardiovascular death. However, for the elderly group, when SBP and DBP were considered jointly in the regression model, then the regression coefficient of DBP (beta = -0.018, p = 0.30) was of approximately the same absolute magnitude as that of SBP (beta = 0.021, p = 0.02) but opposite in sign. For younger men, when SBP and DBP were considered jointly, SBP (beta = 0.021, p = 0.049) but not DBP (beta = -0.001, p = 0.953) was positively related to cardiovascular death. CONCLUSIONS We found that, for the elderly, pulse pressure (SBP-DBP) may be a more accurate predictor of cardiovascular death than either SBP or DBP alone. The relative risk per 35 mmHg of increase of pulse pressure, which equals the approximate interval from the 10th to the 90th percentile in the elderly group, is 2.1 with 95% CI = (1.1, 3.8). In younger subjects, SBP, but not DBP, is an independent predictor of fatal CVD.
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Bowerbank CR, Smith PA, Drown DB, Alexander W, Jederberg WW, Still KR, Lee ML. Chemical detection in deployment toxicology using high speed gas chromatography with a solvating mobile phase and time-of-flight mass spectrometry. Drug Chem Toxicol 1999; 22:57-71. [PMID: 10189571 DOI: 10.3109/01480549909029724] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Solvating gas chromatography (SGC) involves a mobile phase that is a supercritical fluid at the column inlet (typically 100-350 atm) and a gas upon exiting the column at ambient pressure. SGC has characteristics of both supercritical fluid chromatography and gas chromatography, and may be adaptable to a system with characteristics approaching a "universal chromatograph" capable of analyzing many classes of compounds on one instrument. We have recently found that using a solvating mobile phase such as CO2, together with small, spherical particle-packed capillary columns can offer significant advantages for rapid chemical analysis. A need exists in operational military settings to rapidly detect a wide range of chemicals with potential adverse health effects for exposed personnel. A separation step improves analytical capability by reducing or eliminating chemical background for better detection limits, and purifies or isolates target analytes and unknowns for improved identification. SGC, coupled to a high volume vapor/aerosol sampler and a rapid mass spectrometric detector such as a time-of-flight mass spectrometer could provide rapid, positive identification of separated compounds, with the resulting chromatographic and mass spectral data stored in digital format for future retrieval. Such a system will significantly advance the ability of military commanders to detect airborne chemical agents rapidly and accurately, protecting the health of military personnel.
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Shao X, Shen Y, O'Neill K, Lee ML. Capillary electrophoresis using diol-bonded fused-silica capillaries. J Chromatogr A 1999; 830:415-22. [PMID: 10048200 DOI: 10.1016/s0021-9673(98)00851-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In this paper, 3-glycidoxypropyltrimethoxysilane was used to produce diol-bonded capillaries at room temperature for capillary electrophoresis (CE). A variety of standard reference compounds and authentic biological samples including ribonucleotides, peptides and proteins were used to test the columns. It was found that greatly suppressed electroosmotic flow was measured over a pH range of 3-10. Lower than 1.6% relative standard deviation (> 10 runs) in migration time was observed for the analysis of test proteins. For real samples of ribonucleotides in tumor cell extracts, approximately 1 million theoretical plates and excellent peak shapes were obtained. The high column efficiency and symmetrical peaks allowed the separation of samples with only 0.6% maximum difference in migration times. The diol-bonded fused-silica capillary columns were stable when used in a pH range of 2-8 under typical CE conditions. The column preparation method involved a simple dynamic coating procedure at room temperature, greatly simplifying the more typical static coating methods that require vacuum pumps and ovens.
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Abstract
A new computer-controlled capillary electrochromatography (CEC) system was built. Up to +/- 60 kV can be used for CEC separation, and buffer vials can be pressurized to prevent bubble formation and to facilitate conditioning and rinsing of columns. This CEC system is compact and flexible. Short columns can be used to achieve fast separations. A fiber optic detection assembly is used to separate the main body of the UV detector from the high potential to prevent potential discharge and disturbance of the UV absorbance signal. This system was evaluated by separating 16 polycyclic aromatic hydrocarbons (PAHs) on different types of octadecyl silane (ODS) particles. Over 200,000 plates/m (k = 4.4) were obtained using 1.5 microm ODS particles. Voltage programming was used to reduce the analysis time by nearly 50%.
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Abstract
Chronic elbow instability without fractures in adults can be broken down into three types: (1) valgus instability, (2) posterolateral rotator instability, and (3) isolated radial head instability. By far the most common is valgus instability, which usually occurs in throwing athletes as a result of repetitive microtrauma to the anterior band of the medial collateral ligament. Surgical treatment is aimed at reconstruction of the anterior band of the medial collateral ligament. Posterolateral rotatory instability is much less common and is diagnosed by the lateral pivot-shift test of the elbow. It is usually the result of an undiagnosed acute injury to the lateral ulnar collateral ligament. Surgical treatment is aimed at its reconstruction. Isolated radial head subluxation in adults is extremely rare. The essential lesion is a disruption of the annular ligament. Surgical treatment is either radial head resection or reconstruction of the annular ligament.
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Fielding JR, Griffiths DJ, Versi E, Mulkern RV, Lee ML, Jolesz FA. MR imaging of pelvic floor continence mechanisms in the supine and sitting positions. AJR Am J Roentgenol 1998; 171:1607-10. [PMID: 9843296 DOI: 10.2214/ajr.171.6.9843296] [Citation(s) in RCA: 124] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE Our goal was to determine the anatomic differences in pelvic floor anatomy for continent women and women with stress incontinence using MR imaging and to assess whether these anatomic differences depend on the position of the subject during imaging. SUBJECTS AND METHODS Eight continent volunteers and eight women with stress incontinence underwent MR imaging in the supine and sitting positions. For imaging, we used an open-configuration 0.5-T magnet. T2-weighted images were obtained in the midline sagittal plane with subjects at rest and at maximal pelvic floor strain in 5 sec using a modified fast spin-echo sequence. In the axial plane, thin-section T2-weighted images were obtained with subjects at rest using a standard fast spin-echo technique. Images were evaluated for mobility of the urethra and bladder neck and for integrity of the vagina, levator ani, and supporting fascia. RESULTS Pelvic floor laxity and abnormalities of the supporting fascia were more common in incontinent women than in continent women. Both descent of the bladder neck when subjects strained and the posterior urethrovesical angle were not significantly greater when subjects were measured in the sitting position (p < .1). CONCLUSION Changes of pelvic floor laxity related to incontinence can be seen with subjects in both the supine and the sitting positions but are increased in the sitting position.
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Lee ML, Chiu IS, Wu MH, Wang JK, Lue HC, Chaou WT, Tsao LY. Transarterial approach of the pulmonary artery in anatomically corrected malposition of the great arteries by manipulating a catheter inverted with balloon floating maneuver. Int J Cardiol 1998; 67:1-7. [PMID: 9880195 DOI: 10.1016/s0167-5273(98)00247-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
We describe two neonates with anatomically corrected malposition of the great arteries (ACM). A 1-day-old female newborn, who had the salient clinical findings of Goldenhar syndrome, behaved like a patient with the tetralogy of Fallot. The cardiac malformations included ACM, perimembranous inlet and outlet ventricular septal defect with tricuspid valve straddling, conoventricular septal malaligement, bilateral cori without aortic-mitral continuity, pulmonary stenosis at subvalvular, valvular, and supravalvular levels, and bicuspid semilunar valves. After the procedure of left Blalock-Taussig shunt at 3 months of age, cyanosis was alleviated. The other 1-month-old male newborn, who presented with prolonged feeding, tachypnea and tachycardia, likened to a patient with the hypoplastic left heart syndrome. He had a combination of ACM, mitral stenosis, hypoplastic left atrium and left ventricle, a restrictive patent foramen ovale, ventricular septal defect, subaortic conus without aortic-mitral continuity, subaortic stenosis, and a narrow ascending aortic root. Rashkind balloon atrioseptostomy was done with limited success. He survived a Norwood procedure. Transarterial entry of the catheter, which was inverted with the aid of balloon floating maneuver, to hook the retro-aortic pulmonary artery in ACM is recommended.
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Lee ML, Stavchansky S. Isothermal and nonisothermal decomposition of thymopentin and its analogs in aqueous solution. Pharm Res 1998; 15:1702-7. [PMID: 9833991 DOI: 10.1023/a:1011952511091] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
PURPOSE The degradation kinetics of thymopentin (RKDVY) and its analogs (RKDVW and RPDVY) in aqueous solution was studied by isothermal and nonisothermal methods. METHODS The isothermal decomposition of thymopentin and its analogs was investigated as a function of pH (2-10), temperature (37, 57, and 80 degrees C) and ionic strength (micro = 0.02 to 1). Nonisothermal decomposition studies were performed using a linear temperature programmer. The temperature increasing rate was set to 0.25 degrees C per hour and the temperature interval varied from 40 to 88 degrees C. RESULTS The decomposition of thymopentin and its analogs followed first order kinetics. The dependence of the rate constant on temperature followed a linear Arrhenius plot. This indicated that the degradation mechanism of thymopentin and its analogs might be the same within the temperature range studied. The energies of activation were found to be in close agreement for the isothermal and nonisothermal studies, suggesting that the nonisothermal studies may save considerable amount of time in the early stages of drug development. The logK-pH profile of thymopentin suggests that maximum stability is achieved in the pH range of 6-8. CONCLUSIONS These results indicate that the nonisothermal methodology provides an attractive alternative to isothermal methods, as it requires a much lower amount of both material and time, to determine the peptide stability and to estimate the shelf-life for peptide pharmaceutical preparations.
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Lee ML, Dickson RA, Campbell M, Oliphant J, Gretton H, Dalby JT. Clozapine and substance abuse in patients with schizophrenia. CANADIAN JOURNAL OF PSYCHIATRY. REVUE CANADIENNE DE PSYCHIATRIE 1998; 43:855-6. [PMID: 9806095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
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Dresselhaus TR, Luck J, Wright BC, Spragg RG, Lee ML, Bozzette SA. Analyzing the time and value of housestaff inpatient work. J Gen Intern Med 1998; 13:534-40. [PMID: 9734790 PMCID: PMC1497006 DOI: 10.1046/j.1525-1497.1998.00164.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine time allocation and the perceived value to education and patient care of the weekday activities of internal medicine housestaff on inpatient rotations and to compare the work activities of interns and residents. DESIGN An observational study. We classified activities along five dimensions (association, location, activity, time, and value), developed a computer-assisted self-interview survey, and demonstrated its face and content validity, internal consistency, and interrater reliability. Subjects were assigned survey computers for 5 consecutive weekdays over a 24-week period, into which they entered data when prompted several times a day. SETTING The medical service of a university-affiliated Veterans Administration Medical Center. PARTICIPANTS Sixty housestaff (36 interns, 24 residents) rotating on the inpatient wards. MEASUREMENTS AND MAIN RESULTS We analyzed activities according to content (direct patient care, indirect patient care, education), association, and location. Likert-scale ratings of perceived value to education and patient care were also obtained. Housestaff provided complete responses to 3,812 (95%) of 3,992 prompts by a median of 11 seconds; 93% of responses were logically consistent across the measured dimensions. Housestaff spent more time in indirect patient care (56%) than in direct patient care (14%) or educational activities (45%). Formal educational activities had the highest educational value (66 on 0-100 scale), and direct care had the highest value to patient care (81). Over 30% of time was spent in administrative activities, which had low educational value(40). Compared with residents, interns allocated significantly less time to educational activities (38% vs 57%) and more time to lower-value activities such as documentation (19% vs 12%). CONCLUSIONS Improved data collection methods demonstrate that housestaff in our program, particularly interns, spend much of their workday in activities that are low in educational and patient care value. Selective elimination or delegation of such activities would preserve higher-value experiences during reductions in overall inpatient training time. Planners can use automated random sampling to guide the rational redesign of housestaff work.
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Lazar IM, Naisbitt G, Lee ML. Capillary electrophoresis--time-of-flight mass spectrometry of drugs of abuse. Analyst 1998; 123:1449-54. [PMID: 9830158 DOI: 10.1039/a708903a] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The use of capillary electrophoresis (CE) for the determination of drugs of abuse was explored. A commercial CE system was interfaced with a laboratory-built time-of-flight mass spectrometer (TOFMS) which was equipped with a high-speed data acquisition system to provide accurate monitoring of efficient separations. Ionization of the CE eluent was achieved with an electrospray ionization source. Standard mixtures and seized samples were analyzed either by direct infusion of the analyte solutions or after separation by CE. Detection at the low femtomole level was obtained using CE-TOFMS.
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Lee ML, Lazar IM. Comparison of mass spectrometry interfacing techniques for microcolumn liquid separations. Biomed Chromatogr 1998; 12:141-2. [PMID: 9646915 DOI: 10.1002/(sici)1099-0801(199805/06)12:3<141::aid-bmc785>3.0.co;2-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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126
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Sorensen PS, Wanscher B, Jensen CV, Schreiber K, Blinkenberg M, Ravnborg M, Kirsmeier H, Larsen VA, Lee ML. Intravenous immunoglobulin G reduces MRI activity in relapsing multiple sclerosis. Neurology 1998; 50:1273-81. [PMID: 9595974 DOI: 10.1212/wnl.50.5.1273] [Citation(s) in RCA: 172] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
We wanted to assess whether intravenous immunoglobulin G (IVIG) decreases disease activity on MRI in relapsing MS. Previous trials of IVIG in relapsing-remitting MS demonstrated a reduction of acute relapses, but these studies did not include MRI. We treated 26 patients in a randomized, double-blind, crossover study of IVIG 1 g/kg daily or placebo on 2 consecutive days every month during two 6-month treatment periods. The primary end point was the number of gadolinium-enhancing lesions on monthly serial MRI. Secondary efficacy variables were the occurrence of exacerbations, clinical neurologic ratings, total MS lesion load on T2-weighted MRI, and multimodal evoked potentials. Eighteen patients completed the entire trial; eight patients did not. Twenty-one patients completed the first treatment period and at least two MRI examinations in the second treatment period and were included in the intention-to-treat analysis. On serial MRI, we observed fewer enhancing lesions per patient per scan during IVIG treatment (median, 0.4; range, 0 to 9.3) than during placebo treatment (median, 1.3; range, 0.2 to 25.7; p = 0.03). During IVIG treatment, 15 patients were exacerbation free compared with only 7 on placebo (p = 0.02). The total number of exacerbations in the IVIG period was 11 and in the placebo period, 19 (not significant). None of the remaining secondary efficacy measures were significantly different between the two treatment periods. The number of adverse events, in particular eczema, was significantly higher during IVIG therapy than during placebo treatment. These results suggest that IVIG treatment is beneficial to patients with relapsing MS.
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Nag AC, Lee ML. Breakdown and rebuilding of myofibrils in cultured adult cardiac muscle cells. TSITOLOGIIA 1998; 39:907-12. [PMID: 9505337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The myofibrils of adult rat cardiac muscle cells in culture break down and later reorganize into mature myofibrils. The myofibrillar breakdown and reorganization processes have been investigated with electron microscopical and immunocytochemical studies. The immunocytochemical studies included antibodies to actin, myosin, titin, and alpha-actinin. In addition, rhodamine-labeled phalloidin has been used. These studies revealed that the myofibrils were disorganized into amorphous and/or other forms during breakdown process. Some of these myofibrils undergo degradation and finally extrusion through exocytosis. The reorganization of myofibrils takes place mainly with the participation of the existing myofibrillar proteins in myocytes. This remyofibrillogenesis showed the emergence of punctate alpha-actinin from the existing amorphous alpha-actinin along with the differentiation of titin periodicities, which remained attached to the alpha-actinin structures. The punctate alpha-actinin later differentiated into periodicities, forming Z-lines. The periodicities of actin were differentiated from the amorphous actin and associated with the Z-lines, giving rise to titin, alpha-actinin, and actin complexes. Later, myosin filaments became associated with these complexes, forming sarcomeres where other myofibrillar proteins participated in the formation of mature myofibrils. The temporal sequence of differentiation of periodicities of certain myofibrillar proteins varied among different myocytes and within a single myocyte. The dynamic role of adult cardiac myocytes in the reconstruction of myofibrils is a remarkable phenomenon, which stabilizes adult cardiac muscle cells in long-term culture.
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Kerr EA, Hays RD, Lee ML, Siu AL. Does dissatisfaction with access to specialists affect the desire to leave a managed care plan? Med Care Res Rev 1998; 55:59-77. [PMID: 9529881 DOI: 10.1177/107755879805500104] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Frequent changes in health plan enrollment may lead to discontinuity of care and compromise quality. Using multiple logistic regression, we investigated how four dimensions of patient satisfaction were associated with the desire to disenroll from a managed care plan. A total of 17,196 enrollees from a large health plan in California responded to a survey regarding their satisfaction with care and desire to disenroll from the plan. Nineteen percent stated that they wanted to change from the plan. Dissatisfaction with access to specialty care and convenience of care produced the highest calculated relative risks of desire to leave the plan [relative risk ERR] = 2.7 and 2.6, respectively), while dissatisfaction with the quality of care and with hospital care produced lower relative risks (1.8 and 1.5, respectively). Because limiting direct access to specialists is a cardinal feature of most managed care organizations, managed care organizations may need to reexamine their approaches to the specialty care referral process.
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Lee ML, Wang JK, Wu MH, Lue HC, Chiu IS, Chang CI. Clinical implications of isolated double aortic arch and its complex with intracardiac anomalies. Int J Cardiol 1998; 63:205-10. [PMID: 9578345 DOI: 10.1016/s0167-5273(97)00325-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
From July 1, 1989 to June 30, 1996, a total of six patients, four male and two female, with double aortic arch (DAA) were registered. They aged 16 days to 6.5 years. There were two patients with isolated DAA, and four complicated with intracardiac anomalies. All six patients presented respiratory distress and feeding problem early in life. However, cyanosis, owing to decreased pulmonary blood flow, predominated the clinical picture in each patient having DAA intricated with tetralogy of Fallot (TOF) and pulmonary stenosis, TOF with absent pulmonary valve syndrome, and type II-A tricuspid atresia. DiGeorge syndrome was documented in one patient with TOF and pulmonary stenosis. Expiratory wheezing was remarkable in the patient with TOF and absent pulmonary valve syndrome. Mild cyanosis and heart failure was noted in one patient with ventricular septal defect (VSD), and bicuspid pulmonary valve with mild valvular stenosis. Barium esophagogram showed indentations on esophagus in five patients. Echocardiography was yielding in three infants. Four patients, two isolated and two complex DAA, survived the surgical division of the smaller left aortic arch. One-stage and two-stage operation was performed in patients having DAA intricated with VSD and TOF, respectively. The other two patients with complex DAA remained in close observation owing to the tolerance of symptoms related to intracardiac anomalies.
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Chen HD, Shaw CK, Tseng WP, Chen HI, Lee ML. Prevalence of diabetes mellitus and impaired glucose tolerance in Aborigines and Chinese in eastern Taiwan. Diabetes Res Clin Pract 1997; 38:199-205. [PMID: 9483387 DOI: 10.1016/s0168-8227(97)00104-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The aim of this study was to determine the prevalence of diabetes mellitus and impaired glucose tolerance (IGT) in three different ethnic groups in eastern Taiwan. The study was performed among Han Chinese, aboriginal Ami and aboriginal Atayal in six rural villages. Inhabitants aged 40 years and over were invited to participate. A 75-g oral glucose tolerance test (OGTT) was used as suggested by the World Health Organization (WHO) for population screening purposes. WHO criteria were used for determining the results. A total of 1013 adults (460 men and 553 women) were examined with a response rate of 62.1%. There were no significant differences in sex, age and history of diabetes between responders and non-responders. The age-adjusted prevalence of diabetes was 11.0% (9.8% in men and 12.3% in women) in the Chinese, 9.1% (12.1% in men and 7.4% in women) in the Amis, 10.8% (11.5% in men and 9.4% in women) in the Atayal and 9.9% (11.5% in men and 8.5% in women) for the two aboriginal groups together. Although sex differences in prevalence of diabetes were not statistically significant, it seems that diabetes was slightly more prevalent in Chinese women than in Chinese men (12.3 versus 9.8%). Nonetheless, the prevalence rate of diabetes was somewhat higher in the aboriginal males than in the aboriginal females (12.1 versus 9.8% for Ami and 11.5 versus 10.7% for Atayal). The prevalence of IGT was 7.2, 8.5, 10.8 and 9.7% for the Chinese, Amis, Atayal and the two aboriginal groups, respectively. There were no substantial differences in the prevalence of diabetes and IGT among these three ethnic groups. Environment, rather than ethnicity, was more likely the predominant factor. It was found that the prevalence of diabetes in this study was about twice as high as that reported in a 1987 survey in Taiwan. The discrepancy may be due to different screening methods and assessment periods.
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Hougaard P, Lee ML, Whitmore GA. Analysis of overdispersed count data by mixtures of Poisson variables and Poisson processes. Biometrics 1997; 53:1225-38. [PMID: 9423246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Count data often show overdispersion compared to the Poisson distribution. Overdispersion is typically modeled by a random effect for the mean, based on the gamma distribution, leading to the negative binomial distribution for the count. This paper considers a larger family of mixture distributions, including the inverse Gaussian mixture distribution. It is demonstrated that it gives a significantly better fit for a data set on the frequency of epileptic seizures. The same approach can be used to generate counting processes from Poisson processes, where the rate or the time is random. A random rate corresponds to variation between patients, whereas a random time corresponds to variation within patients.
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Lee ML, Tsao LY. Spontaneous regression of aneurysmal nonpatent ductus arteriosus: report of a neonate case. ZHONGHUA MINGUO XIAO ER KE YI XUE HUI ZA ZHI [JOURNAL]. ZHONGHUA MINGUO XIAO ER KE YI XUE HUI 1997; 38:484-6. [PMID: 9473824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
We report a newborn baby boy with an aneurysmal ductus arteriosus, that underwent spontaneous regression in the 2 years follow-up. Plain chest films showed the clue. Echocardiography, magnetic resonance imaging and angiocardiography are helpful in the differential diagnosis of other superior mediastinal mass. Perinatal asphyxia and hypoxemia may contribute to the formation of the ductal aneurysm. Intravenous infusion of dopamine and dobutamine may precipitate the nonpatency of the ductal aneurysm.
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Márquez CD, Lee ML, Weintraub ST, Smith PC. Quantitative analysis of exogenous peptides in plasma using immobilized enzyme cleavage and gas chromatography-mass spectrometry with negative ion chemical ionization. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1997; 700:9-21. [PMID: 9390710 DOI: 10.1016/s0378-4347(97)00313-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A method is presented for the analysis of peptides in plasma at picomole to femtomole levels. Peptides are isolated from plasma by solid-phase extraction, the peptide of interest is purified by reversed-phase high-performance liquid chromatography (HPLC) and selectively digested using immobilized trypsin or chymotrypsin to yield specific di- or tripeptides. These di- and tripeptides are esterified using heptafluorobutyric anhydride, alkylated with pentafluorobenzyl bromide, then quantified by gas chromatography-mass spectrometry with negative ion chemical ionization. This method has been evaluated for a model synthetic heptapeptide, using a deuterium labeled analog as an internal standard. The half-life of the heptapeptide in human plasma was found to be 2 min. Extraction efficiencies of a tritiated peptide of similar size to the heptapeptide, [3H]DSLET, from plasma using either C18 or strong cation-exchange columns were 85+/-3 and 70+/-2%, respectively. Quantitation of fragments from the heptapeptide indicated that the analysis was linear from 1-50 ng of the heptapeptide per ml of plasma. This method was subsequently employed for pharmacokinetic studies of the biologically active peptide Met-enkephalin-Arg-Gly-Leu, where linearity was obtained from 50 to 1000 ng/ml in rat plasma. This method demonstrated negligible side reaction by-products due to autolysis, and has potential for extensive use given the wide availability of gas chromatography-mass spectrometry.
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Carpenter JE, Kasman RA, Patel N, Lee ML, Goldstein SA. Biomechanical evaluation of current patella fracture fixation techniques. J Orthop Trauma 1997; 11:351-6. [PMID: 9294799 DOI: 10.1097/00005131-199707000-00009] [Citation(s) in RCA: 159] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVE To compare the mechanical effectiveness of three different techniques for stabilization of transverse fractures of the patella. DESIGN Cadaveric knees were used to model acute fractures of the patella. To test three treatment techniques in pairs of knees, specimen pairs were assigned randomly to a set of predetermined treatment pairs so as to provide equal numbers of paired and unpaired data sets. Results then were analyzed using a two-way analysis of variance. SETTING The treatment techniques used are widely applicable in the clinical setting for the treatment of transverse fractures of the patella. No specialized equipment or training is required for the general or subspecialized orthopaedic surgeon. PATIENTS/PARTICIPANTS None. INTERVENTIONS Fractures were created in eighteen knees (nine pairs) and repaired by one of three techniques: (a) modified tension band (AO technique); (b) two parallel 4.5-millimeter interfragmentary lag screws; or (c) a new technique using four-millimeter cannulated lag screws with a tension band wired through the screws. MAIN OUTCOME MEASURES In mechanical testing, the amount of interfragmentary separation in simulated knee extension and the maximum load to failure at 45 degrees of flexion were measured. RESULTS Fractures stabilized with a modified tension band were found to displace significantly more than those fixed with screws alone or screws plus a tension band in simulated knee extensions (p < 0.05). The fractures fixed with the cannulated screws plus the tension band failed at higher loads (mean = 732 newtons) than those stabilized with screws alone (mean = 554 newtons, p = 0.06) or those with a modified tension band (mean = 395 newtons, p < 0.05). CONCLUSIONS Combining interfragmentary screw fixation with the tension band principle appears to provide improved stability over the modified tension band or screws alone for transverse patella fractures. Cannulated screws allow for simple, reliable addition of a tension band to screw fixation.
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Chen MC, Lee ML. [Marital status and life expectancy]. IN'GU MUNJE NONJIP = JOURNAL OF POPULATION STUDIES 1997:19-38. [PMID: 12222460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
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Poteat HT, Ho GT, Lee ML, Welch WR, Loughlin KR, Sacks DB. The utility of patient age in evaluating prostate cancer. Am J Clin Pathol 1997; 107:337-44. [PMID: 9052385 DOI: 10.1093/ajcp/107.3.337] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The utility of age in examining patients for prostate cancer was assessed. Of the 462 patients in the study, 138 had prostate cancer. The age distribution of the patients with cancer was similar to that found in patients with prostate cancer in the US population, and a correlation between age and the serum prostate-specific antigen (PSA) value was noted (r = .4, P < .002). Selection of reference intervals had a significant effect on test performance. Using an interval of 0 to 4.0 ng/mL, sensitivity of the PSA assay was 90% overall and varied from 78% (patients aged 50-59 years) to 94% (patients aged 70-79 years). In contrast, age-adjusted reference ranges yielded corresponding sensitivities of 84%, 78%, and 88%. With a single, fixed reference range, specificity decreased with advancing patient age (P < .001). This trend was eliminated by adjusting the cutoff in different age groups. In addition, age-adjusted reference ranges improved specificity by 10%, and by using the results of examination of a biopsy specimen as the "gold standard," the total number of patients classified correctly by PSA increased from 226 to 250 (49%-54%). For staging before treatment, patient age, clinical stage, and Gleason score were combined to yield a single probability estimate for organ-confined disease (P < .001). The use of age-adjusted reference ranges is supported by this study, which demonstrates that assay efficiency and specificity improve and sensitivity, although decreased overall, becomes more uniform across age groups. In this patient population, age was useful in determining the probability of organ-confined prostate cancer. Use of this model in clinical decision making should await evaluation in a prospective trial.
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Lee ML, Gale RP, Yap PL. Use of intravenous immunoglobulin to prevent or treat infections in persons with immune deficiency. Annu Rev Med 1997; 48:93-102. [PMID: 9046948 DOI: 10.1146/annurev.med.48.1.93] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Intravenous immunoglobulin (IVIG) concentrates were originally developed as replacement therapy for individuals with primary deficiencies of the immune system. However, in various well-designed, controlled clinical trials, the ability of IVIG to prevent and possibly treat infections in patients with secondary immune deficiencies has also been considered. In this review, we briefly consider these different applications and suggest whether the data are sufficient to employ IVIG in these clinical settings.
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Lee ML, Chao YF. [Exercise testing and clinical application in cardiac rehabilitation]. HU LI ZA ZHI THE JOURNAL OF NURSING 1996; 43:54-60. [PMID: 9379228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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139
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Bale SJ, Russell LJ, Lee ML, Compton JG, DiGiovanna JJ. Congenital recessive ichthyosis unlinked to loci for epidermal transglutaminases. J Invest Dermatol 1996; 107:808-11. [PMID: 8941665 DOI: 10.1111/1523-1747.ep12330566] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Congenital recessive ichthyosis has a broad range of clinical presentations, which may be considered a spectrum of phenotypes with classic lamellar ichthyosis at one pole and classic congenital ichthyosiform erythroderma at the other. The identification of mutations in the transglutaminase-1 gene as a cause of lamellar ichthyosis implicates transglutaminases in other congenital recessive ichthyoses. We investigated two multiplex families with clinical manifestations between the two poles for linkage to the transglutaminase-1 locus on chromosome 14. Strongly negative lod scores prompted a search for linkage to two other epidermally expressed transglutaminases, transglutaminase-2 and transglutaminase-3, on chromosome 20. No evidence for linkage was found. These data confirm the hypothesis that the congenital recessive ichthyoses are genetically heterogeneous and in two families exclude two other transglutaminases that could be considered as candidate loci for at least some of the nonlamellar recessive ichthyoses.
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Gifford DR, Mittman BS, Fink A, Lanto AB, Lee ML, Vickrey BG. Can a specialty society educate its members to think differently about clinical decisions? Results of a randomized trial. J Gen Intern Med 1996; 11:664-72. [PMID: 9120652 DOI: 10.1007/bf02600157] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE Measure the effect of specialty society-developed continuing medical education (CME) on clinical decision making. DESIGN Randomized controlled trial. SETTING National sample of neurologists. PARTICIPANTS Of 492 neurologists randomly selected from an ongoing American Academy of Neurology CME program, 248 were randomized to receive a mailed CME course, and 244 did not receive it. INTERVENTION A mailed educational course on movement disorders, developed by the specialty society, containing information on diseases and practice recommendations with illustrative case presentations. MEASUREMENTS AND MAIN RESULTS We assessed adherence to 16 practice recommendations on disease detection, diagnostic test use, and treatments by mailed survey sent to all subjects 4.5 months after the intervention group received the course (73% response rate). The survey contained detailed clinical scenarios to measure self-reported clinical decision making and short open-ended questions to measure factual knowledge. More intervention participants (up to 2.6 times more) than control subjects reported clinical decision making adherent to 9 of the 16 recommendations (p < .05). For 4 of the other 7 recommendations, adherence exceeded 85% in both groups. Within the intervention group, neurologists who read the educational course were 2 to 6 times more likely to be adherent than neurologists who did not. The intervention group had better factual knowledge than control subjects in six of seven areas (p < .01). CONCLUSIONS This educational course improved neurologists' reported decision making. Specialty society-developed CME that utilizes a similar format may enhance the effectiveness of mailed CME information to improve physicians' approach to clinical decisions.
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Tsai CE, Chiu PC, Lee ML. Kenny syndrome: case report and literature review. J Formos Med Assoc 1996; 95:793-7. [PMID: 8961678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
A 34-month-old girl presented with a clinical picture of Kenny syndrome. The clinical manisfestations included growth retardation, persistent open anterior fontanelle, prominent forehead, mid-facial dysplasia, hypocalcemic tetany and characteristic radiologic skeletal abnormalities. Serum levels of immunoreactive parathyroid hormone (PTH) remained inappropriately low during hypocalcemic episodes in the neonatal period; indicating that hypocalcemia was a consequence of the hypoparathyroid state. This is the first reported case of Kenny syndrome in Taiwan. The literature on the pathogenesis, etiology and genetic basis of this disorder is reviewed in this paper.
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Bain PG, Motomura M, Newsom-Davis J, Misbah SA, Chapel HM, Lee ML, Vincent A, Lang B. Effects of intravenous immunoglobulin on muscle weakness and calcium-channel autoantibodies in the Lambert-Eaton myasthenic syndrome. Neurology 1996; 47:678-83. [PMID: 8797464 DOI: 10.1212/wnl.47.3.678] [Citation(s) in RCA: 138] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Intravenous immunoglobulin improves many antibody-mediated autoimmune disorders, but its mode of action is unknown. We investigated its effects on muscle strength and on the serum titer of the calcium-channel autoantibodies that are likely to be pathogenic in the Lambert-Eaton myasthenic syndrome (LEMS). In a randomized, double-blind, placebo-controlled crossover trial, serial indices of limb, respiratory, and bulbar muscle strength and the serum titer of calcium-channel antibodies in nine patients were compared over an 8-week period, using the area-under-the-curve approach, following infusion on two consecutive days of immunoglobulin at 1 g/kg body weight/day (total dose 2.0 g/kg body weight) or placebo (equivalent volume of 0.3% albumin). Calcium-channel antibodies were measured by radioimmunoassay using 125I-omega-conotoxin MVIIC. Direct anti-idiotypic actions of immunoglobulin were tested in this assay. Immunoglobulin infusion was followed by significant improvements in the three strength measures (p = 0.017 to 0.038) associated with a significant decline in serum calcium-channel antibody titers (p = 0.028). Improvement peaked at 2 to 4 weeks and was declining by 8 weeks. Mean serum titers were unchanged at 1 week, however, and direct anti-idiotypic neutralization by immunoglobulin was not demonstrable in vitro. We conclude that immunoglobulin causes a short-term improvement in muscle strength in LEMS that probably results from the induced reduction in calcium-channel autoantibodies. The reduction is not due to a direct neutralizing action of the immunoglobulin, but a delayed anti-idiotypic action cannot be excluded. Improvement following intravenous immunoglobulin in other autoantibody-mediated disorders may similarly be associated with decline in levels of pathogenic autoantibodies.
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Tsai TC, Huang FY, Hsu JC, Lee ML, Chou LH. Continuous ambulatory peritoneal dialysis complicating with abdominal hernias in children. ZHONGHUA MINGUO XIAO ER KE YI XUE HUI ZA ZHI [JOURNAL]. ZHONGHUA MINGUO XIAO ER KE YI XUE HUI 1996; 37:263-5. [PMID: 8854347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
From May 1991 through December 1995, 10 uremic children ranging in age from 3.6 years old to 14.4 years old underwent insertion of 13 peritoneal dialysis catheters for continuous ambulatory peritoneal dialysis (CAPD). Eight abdominal hernias developed, associated with five catheters (38.5%) in four of the patients. Three hernias were inguinal, three were umbilical, one was epigastric, and one occurred at the catheter insertion site. Six hernias, including one umbilical hernia developing incarceration, were repaired. After operations because of recurrent hernias, two patients were switched from standard CAPD to night intermittent PD (NIPD) using low volumes of dialysate. Male sex and age younger than six years were possible associated risk factors (P = 0.19). In conclusion, hernia in young children undergoing CAPD is not unusual, and early surgical repair is advisable to avoid complications.
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Nag AC, Lee ML, Sarkar FH. Remodelling of adult cardiac muscle cells in culture: dynamic process of disorganization and reorganization of myofibrils. J Muscle Res Cell Motil 1996; 17:313-34. [PMID: 8814551 DOI: 10.1007/bf00240929] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The myofibrils of adult rat cardiac muscle cells in long-term culture initially break down and later reassemble into mature myofibrils. The objective of this study is to examine the disorganization process of myofibrils and to determine how disorganized myofibrillar proteins, myosin, titin, actin, and alpha-actinin are reorganized into mature myofibrils in adult cells. After dismantlement of myofibrils during initial culture period (24-72 h), myofibrillar proteins became disorganized into amorphous form. These proteins later were observed in vesicular, amorphous, and nonstriated fibrillar forms. Some vesicular structures, containing mainly myosin, titin, alpha-actin, and alpha-actinin were observed on the outer surfaces of the cell and outside the cell body. Such vesicles containing F-actin were rare. Punctate structures of alpha-actinin emerged from the pre-existing amorphous alpha-actinin along with the appearance of mostly titin periodicities. The periodicities of alpha-actinin later became prevalent, followed by the appearance of periodicities of actin. alpha-actinin provided an initiation point on which titin and actin became associated, forming titin-associated I-Z-I structures. Titin traversed the I-bands on either side of the Z-line. The phalloidin-stained I-Z-I structures bound to antibodies to muscle specific sarcomeric proteins (titin, alpha-actin, alpha-actinin). The differentiation of myosin periodicities lagged behind those of titin, alpha-actinin, and actin although presarcomeric structures of immunolabelled titin and myosin were very closely linked in their distributions in the formative myofibrils. Variations in the temporal sequence of emergence of periodicities of alpha-actinin and myosin were observed among certain myocytes. Also observed was the variation of the temporal sequence of emergence of titin and actin periodicities among different myocytes and within a single myocyte. Even in the late stage of culture (30 days), when the cell body was packed with myofibrils, the myocytes contained remnants of amorphous myofibrillar proteins.
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Lee MS, Lee ML, Fryer J, Saurajen A, Guay JL. Oral papillary plasmacytosis cleared by radiotherapy. Br J Dermatol 1996; 134:945-8. [PMID: 8736343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
We report a case of oral papillary plasmacytosis which initially responded well to etretinate and, subsequently, was successfully treated with radiotherapy, with minimal side-effects.
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Tsai TC, Huang FY, Lee ML, Chou LH. Varicella pneumonitis in a child undergoing CAPD. ARCH ESP UROL 1996; 16:192-3. [PMID: 9147562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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Lee ML, Wu MH, Wang JK, Chiu IS, Lue HC. Echocardiographic features of left juxtaposed atrial appendages associated with dextro-transposition of the great arteries. Pediatr Cardiol 1996; 17:63-6. [PMID: 8778707 DOI: 10.1007/bf02505817] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We found that echocardiography in cases of left juxtaposed atrial appendage (JAA) consistently featured a malpositioned right atrial appendage, abnormal spatial orientation of the atrial septum, and posterior deviation of the septum secundum toward the left atrium. The qualitative displacement of the septum secundum together with the posterior and leftward displacement of the right atrial appendage (with respect to the great arteries) prompted us to pose questions concerning the morphogenesis of left JAA and the implications for surgery. The importance of precatheterization and preoperative recognition of left JAA in dextrotransposition of the great arteries by echocardiography cannot be overemphasized when planning a balloon atrial septostomy or a biventricular repair.
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Ross RA, Lee ML, Onderdonk AB. Effect of Candida albicans infection and clotrimazole treatment on vaginal microflora in vitro. Obstet Gynecol 1995; 86:925-30. [PMID: 7501341 DOI: 10.1016/0029-7844(95)00318-l] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
OBJECTIVE To determine the effect of Candida albicans infection and clotrimazole treatment on vaginal microflora. METHODS Studies were conducted using a model simulating the healthy vaginal ecosystem. The model consisted of a mixed culture of Lactobacillus acidophilus, Staphylococcus epidermidis, Prevotella bivia, and group D Streptococcus sp grown in continuous culture in a chemically defined medium. The status of the model was assessed using a mathematical equation that determines the probability a microflora is normal or abnormal. RESULTS Challenge of the model with C albicans was followed within 24 hours by the development of microbial populations representing an abnormal microflora. Treatment of the system with clotrimazole (100 micrograms/mL) resulted in a decrease in C albicans counts to 0 within 48 hours. However, treatment also altered other components of the vaginal microflora, which did not return to normal. Addition of clotrimazole (100 micrograms/mL) to the system in the absence of C albicans also resulted in an abnormal model by 24 hours. CONCLUSIONS Candida albicans infection of the vaginal ecosystem, as represented by this in vitro model, has a deleterious effect on members of the normal microflora. Clotrimazole, although effective against C albicans infection, also has a deleterious effect on components of the normal vaginal microflora. One of the implications for women using clotrimazole for microbiologically undocumented vaginal yeast infections is an increased risk of infection or disease through the disruption of the protective microflora barrier.
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Lee ML, Wang JK, Wu MH, Chu SH, Lue HC. Unusual form of total anomalous pulmonary venous connection with double drainage. Pediatr Cardiol 1995; 16:301-3. [PMID: 8650019 DOI: 10.1007/bf00798067] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A patient with complex congenital heart disease was diagnosed by two-dimensional echocardiography. Total anomalous pulmonary venous connection (TAPVC) was suspected because of the results of two-dimensional echocardiography, but the exact anatomy was delineated by cineangiocardiography as an unusual form of TAPVC with double drainage or connections to the left superior vena cava at nearly the same level. The clinical implications and possible embryogenesis for such a condition are discussed.
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