Biomedical subjects

A M Lee

Publications and source records attributed to A M Lee.

At least 37 records · Page 2Linked to original sources

PubMed1999

Report of a single-institution experience using the EVT endovascular abdominal aortic aneurysm graft in 25 patients.

The purpose of this study was to review a single-institution experience with the Endovascular Technologies [(EVT) Menlo Park, CA] transfemoral, endovascular system of abdominal aortic aneurysm repair. This study was performed at a medical center participating in the phase 1 and phase 2 evaluations of the EVT device. We reviewed the 25 cases performed at our institution. The patient population consisted of 21 males (84%) and 4 females (16%), with a mean age of 73.4 years. A total of eight tube grafts (32%) and 17 bifurcated grafts (68%) were attempted. Twenty-two of the twenty-five grafts were successfully implanted endovascularly (88%). Implantation failures were due to tortuosity or inadequate caliber of the iliac arteries, or incorrect positioning of the graft. The results show that endovascular repair of abdominal aortic aneurysms is an appropriate treatment for selected patients. Conversions to open repair have decreased as experience has grown; careful patient selection can minimize the number of unsuccessful implantations. Patient selection and accurate technique can also minimize the number of endoleaks.

Aged↗

PubMed1999

Wrapping hydroxyapatite orbital implants with posterior auricular muscle complex grafts.

PURPOSE: To report the use of posterior auricular muscle complex grafts as a wrapping material for hydroxyapatite orbital implants in enucleation surgery. METHOD: In a retrospective multicenter study, autogenous posterior auricular muscle complex grafts were used to cover hydroxyapatite orbital implants in 83 patients with a mean age of 38.6 years (range, 1 to 85 years), of whom 63 had primary unilateral enucleation and 20 had secondary orbital implants following enucleation. The mean follow-up period after posterior auricular muscle complex grafts was 36 months (range, 14 to 60 months). RESULTS: Of the 83 patients, two (2.4%) developed limited orbital implant exposure, which was treated with a second posterior auricular muscle complex "patch graft." No patient developed postoperative orbital infection or implant extrusion. All patients were fitted with an acceptable prosthesis and had satisfactory cosmetic and functional results. No patient developed vascular compromise or a wound defect associated with the posterior auricular donor site. CONCLUSION: Autogenous posterior auricular muscle complex grafts should be considered as an appropriate wrapping material for hydroxyapatite orbital implants for primary enucleation and for secondary orbital implants after enucleation.

Adolescent↗

PubMed1999

Immediate and late explantation of endovascular aortic grafts: the endovascular technologies experience.

PURPOSE: The morbidity and clinical outcome of the failure to successfully repair an abdominal aortic aneurysm with Endovascular Technologies (EVT) grafts, resulting in explantation of the device, was assessed. METHODS: The records of all patients worldwide undergoing attempted endovascular repair with EVT devices from February 1993 to October 1997 were retrospectively reviewed. Of 669 patients, 19 (3%) were converted to open procedure with immediate explantation during the initial attempt at endovascular repair, and 27 patients (4%) required explantation at a later date, ranging from 1 day to 40 months. The incidence, morbidity, mortality, and effect on clinical outcome were evaluated. RESULTS: Causes of immediate conversion with explantation were: inaccurate deployment of the proximal or distal attachment systems (11 of 19; 58%); twists in the system (3 of 19; 16%); mechanism malfunction during deployment (4 of 19; 21%); and an aortic tear (1 of 19; 5%). Among the 27 patients undergoing late explantation, 20 (74%) did so because of persistent endoleaks. Three cases (11%) were performed because of aneurysm rupture, three (11%) because of graft occlusion, one because of aortic dissection (4%), and one (4%) because of graft migration into the aneurysm sac. The overall perioperative mortality rate was 11% (2 of 19) for immediate explantation and 7% (2 of 27) for late explantation. The average length-of-stay was 11 days for immediate explantation and 14 days for late explantation (NS). Complications included myocardial infarction (4%), pulmonary insufficiency (13%), wound infection (4%), and permanent renal failure (2%). There were no significant differences in the incidence rates of these complications between immediate and late explants. No cases of limb loss occurred. Median American Society of Anesthetists (ASA) classification was 3, and there was no correlation between ASA classification and mortality rate. Average operating time was 374 minutes for immediate explantation (including the time for the failed endovascular procedure) and 185 minutes for late explantation. CONCLUSION: Immediate and late explantation are infrequent events, occurring in 3% and 4%, respectively, of attempted EVT endovascular aortic stent placements. The mortality rate was higher for both immediate (11%; P <.05) and late (7%; NS) explantation when compared with the mortality rate of all patients undergoing EVT aortic endograft placement (1.5%). There does not appear to be increased long-term morbidity among patients undergoing successful explantation. Early recognition of the need to convert to open procedure, device improvement, and increased operator experience should continue to minimize the incidence of immediate and late explantation and their associated complications.

Aged↗

PubMed1998

Repetitive DNA insertion in a protein kinase ORF of a latent FSV (Feldmannia sp. virus) genome.

We describe the structure of a Feldmannia sp. virus (FsV) genome integrated in the brown alga, Feldmannia. This integrated FsV genome appears to be permanently inactivated and lost its ability to excise and replicate. Unlike the replicated form of FsV, this integrated FsV genome contains a large (>50 kb) repeat region inserted in a protein kinase open reading frame. While related to the 173-bp repeats previously characterized in the FsV genome (Lee et al., 1995), Southern blot analysis indicates that the repeats in the inactive, integrated FsV genome are distinct from those previously characterized. Fine structural analysis of the repeat-insertion sites in the protein kinase gene indicates that there are 8- and 10-bp palindromic sequences present in multiple locations located near the repeat-insertion site. The translated protein kinase contains all of the catalytic motifs conserved in most serine/threonine protein kinases and a potential autophosphorylation site. This protein kinase gene is expressed as RNA in sporophyte plants where virus production is active but not in gametophyte plants where the virus genome is latent. The structure of the integrated virus genome is discussed.

Amino Acid Sequence↗

PubMed1998

Cross-cultural validity of the Eating Disorder Inventory: a study of Chinese patients with eating disorders in Hong Kong.

OBJECTIVE: To evaluate the cross-cultural validity of the Chinese version of the Eating Disorder Inventory (EDI) in a clinical sample of patients with eating disorders in Hong Kong. METHOD: After comprehensive clinical assessment, a consecutive series (1990-1996) of Chinese patients with bulimia nervosa (N = 17) and broadly diagnosed anorexia nervosa (N = 26) completed the Chinese EDI. Results were compared with those of Chinese female undergraduates (N = 606) and Canadian patients with eating disorders. RESULTS: The EDI profiles of bulimic and fat phobic anorectic patients were remarkably and modestly similar to those of their Canadian counterparts. The EDI meaningfully distinguished bulimic patients and fat phobic anorectic patients from local undergraduates, but exhibited deficient criterion-related validity in nonfat phobic anorectic patients. DISCUSSION: The questionable validity of certain EDI subscales in nonfat phobic patients reflects the ethnospecific constructs upon which they are based, and weakens the efficacy of the EDI in screening for anorexia nervosa in Chinese populations. Apart from illustrating some of the conceptual and methodological issues that need to be tackled in the cross-cultural study of the eating disorders, this study furnishes empirical support for the syndromal homogeneity of bulimia nervosa, and the clinical grouping of anorexia nervosa into fat phobic and nonfat phobic subtypes.

Adult↗

PubMed1998

Changes in respiratory quotient elicited in rats by a conditioned stimulus predicting food.

The present study examined whether changes in energy expenditure and energy substrate utilization occur in rats exposed to a conditioned stimulus that signals food. In a differential conditioning procedure, rats were given conditioning sessions where one of two cues (either a flashing light or buzzer) predicted a carbohydrate-rich meal (CS+) while the other cue predicted no food (CS-). In two subsequent test sessions, indirect calorimetry was used to measure respiratory quotient, energy expenditure, and locomotor activity before, during, and after a 15-min CS+ or CS- presentation. The CS+ was found to significantly increase respiratory quotient, indicating a shift in the energy substrate being utilized toward carbohydrate. The CS+ also increased energy expenditure and locomotor activity, but these effects were more variable across rats. It is concluded that respiratory quotient may rise in anticipation of a carbohydrate-rich meal. Possible mechanisms underlying this effect are discussed.

Animals↗

PubMed1998

Rigid gas permeable contact lens fitting after radial keratotomy.

PURPOSE: The purpose of our study was to determine whether radial keratotomy (RK) patients could be fit with rigid gas permeable (RGP) contact lenses based on postoperative keratometry measurements. METHODS: Thirteen eyes from eight post-RK patients were fit with RGP lenses for residual refractive errors. Since these patients were self-referred and were operated on elsewhere, preoperative keratometry readings were not available. We used postoperative keratometry readings for base curve selection; and spherical polymethylmethacrylate diagnostic lenses were used for fitting. RESULTS: Visual improvements averaged 3.85 Snellen lines (range: 1-8 lines). Prefitting visual acuities were: 20/30 (5 eyes); 20/40 (1 eye); 20/ 50 (1 eye); 20/60 (1 eye); 20/70 (3 eyes); 20/150 (1 eye); and 20/200 (1 eye). Final visual acuities were 20/20 (7 eyes), 20/25 (4 eyes), 20/30 (1 eye), and 20/40 (1 eye). CONCLUSION: We found that when fitting post-RK eyes with RGP contact lenses preoperative keratometry was unnecessary, and an empirical fitting method based on postoperative keratometry was successful.

Adult↗

PubMed1997

Age-related differences in breast carcinoma knowledge, beliefs, and perceived risk among women visiting an academic general medicine practice.

BACKGROUND: This study assessed whether age-related differences in breast carcinoma knowledge and perceived risk exist among women in a primary care setting and whether these women's beliefs about the best age to begin screening mammography reflect those of their physicians. METHODS: Consecutive women ages 30-70 years who visited an academic general medicine practice were asked to complete a questionnaire assessing breast carcinoma knowledge, beliefs, and perceived risk. Women's risk estimates were compared with individual risk probabilities derived from the Gail model. Women's beliefs about when to begin screening mammography were compared with the beliefs of the attending physicians in the practice. Questionnaire results were compared across age groups. RESULTS: Six hundred seventy-four women completed the survey. Overall, knowledge scores were negatively correlated with age (correlation coefficient = -0.30, P = 0.001). The level of knowledge about the benefits of mammography was high across all age groups. In contrast, knowledge that breast carcinoma incidence increases with age was poor. Only 28% of all women recognized that breast carcinoma is more common among women age 65 years than among women age 40 years. Among all women, 26% underestimated their risk of developing breast carcinoma in the next 10 years, 32% correctly estimated their risk, and 42% overestimated their risk. Fifty-five percent thought that mammography should begin when a woman is age 30-35 years. In contrast, all surveyed physicians recommended that a woman start undergoing mammography at age 40 years or older. CONCLUSIONS: In this primary care setting, older women had poorer breast carcinoma knowledge than younger women but were equally likely to appreciate the benefits of mammography. Most women were unaware that age is a risk factor for breast carcinoma. Improved education of females by their physicians may resolve some of the observed discrepancies regarding the optimal age to begin screening mammography.

Adult↗

PubMed1997

Identification of a structural constituent and one possible site of postembryonic formation of a teleost otolithic membrane.

A gelatinous otolithic membrane (OM) couples a single calcified otolith to the sensory epithelium in the bluegill sunfish (Lepomis macrochirus) saccule, one of the otolithic organs in the inner ear. Though the OM is an integral part of the anatomic network of endorgan structures that result in vestibular function in the inner ear, the identity of the proteins that make up this sensory accessory membrane in teleosts, or in any vertebrate, is not fully known. Previously, we identified a cDNA from the sunfish saccular otolithic organ that encoded a new member of the collagen family of structural proteins. In this study, we examined biochemical features and the localization of the saccular collagen (SC) protein in vivo using polyclonal antisera that recognize the noncollagenous domains of the SC protein. The SC protein, in vivo, was identified as a 95-kDa glycoprotein in sunfish whole-saccule lysate and in homogenates of microdissected saccular OMs. Immunohistochemical analyses demonstrated that the SC protein was localized within one of the two distinct layers of the sunfish saccular OM. The SC protein was also detected within the cytoplasm of supporting cells at the edges of the saccular sensory epithelium, indicating that these cells are a primary site for the synthesis of this structural protein. Further studies of the organization of this matrix molecule in the OM may help clarify the role of this sensory accessory membrane in vestibular sensory function.

Animals↗

PubMed1997

Psychometric properties of the Eating Disorders Inventory (EDI-1) in a nonclinical Chinese population in Hong Kong.

OBJECTIVES: To evaluate the psychometric properties of the Chinese Eating Disorders Inventory (EDI-1) in a nonclinical population in Hong Kong. METHOD: 1,172 (females 606, males 566) Chinese undergraduates completed the Chinese EDI-1; 105 of them also completed the 12-item General Health Questionnaire (GHQ-12). RESULTS: In female subjects, the Chinese EDI-1 and its subscales met conventional standards of internal consistency, item-total, item-subscale, and subscale correlations, and exhibited an excellent degree of factorial integrity. The subscales discriminated among male, female, high Drive for Thinness, high Body Dissatisfaction, constitutionally slim, and Canadian female subjects. Female GHQ-12 cases and noncases were only distinguished by the Interpersonal Distrust, Interoceptive Awareness, and Ineffectiveness subscales. 3.3% of female subjects could be characterized as being pathologically weight preoccupied. DISCUSSION: This study provides preliminary evidence that the Chinese EDI-1 is an economical, reliable, and potentially useful self-report instrument for investigating the psychological and behavioral dimensions of eating disorders in Hong Kong. But further work is needed to evaluate its transcultural validity in clinical and less modernized Chinese populations.

Adolescent↗

PubMed1997

Development of an instrument to assess cognitive processes in physical education classes.

Using the mediating process paradigm (Doyle, 1977) as a framework, the need to develop reliable and valid instruments for assessing cognitive processes is apparent, and that was the purpose of this study. Participants (N = 819) completed the Cognitive Processes Questionnaire in Physical Education (CPQPE), as well as three other instruments addressing dispositional goal orientation, perception of motivational climate, and beliefs about causes of success in physical education. The five-factor structure that emerged in an exploratory factor analysis produced an acceptable fit with the data in the confirmatory factor analysis. The subscales of the CPQPE were related to a task-involved goal perspective and the belief that success is attributed to motivation and effort. The results indicate the CPQPE is a valid and reliable instrument that can provide valuable information about the teaching and learning process.

Achievement↗

PubMed1997

The atypical antipsychotic sertindole: a case series.

BACKGROUND: Psychotic disorders are often difficult to treat with traditional neuroleptics. Sertindole is a new atypical neuroleptic with a broader CNS receptor profile. METHOD: Ten patients diagnosed with either schizophrenia or schizoaffective disorder were treated with sertindole for 18 months and observed for changes in Clinical Global Impression scale scores. RESULTS: Nine patients experienced a reduction of symptoms after 12 months of treatment. Eight patients completed 18 months of treatment, all exhibiting overall improvement. Despite side effects of tiredness, weight gain, headache, nausea, and decreased ejaculatory volume, sertindole was generally well tolerated. CONCLUSION: Sertindole appears to be a useful treatment in psychotic disorders. It may present an advantage over traditional neuroleptics in the form of fewer extrapyramidal symptoms and improvement of negative symptoms.

Adolescent↗

PubMed1996

A Feldmannia algal virus has two genome size-classes.

Persistent viruses occur intracellularly in brown algae, specifically the Ectocarpales, and as reported here in the genus Feldmannia. Feldmannia species are small (1 mm-several cm), filamentous forms with single-celled meiotic sporangia that normally produce haploid zoospores. In the isolate reported here, spores were not observed in the sporangia but rather numerous (approximately 10(6) per cell) polyhedral viruses are formed in their place. Two dsDNA genome classes of 158 and 178 kbp, with two restriction site variants of each, are described. The individual abundance of each genome in viral preparations is affected by culture temperature. A cosmid library was used to generate circular restriction enzyme (BamHi, Noti, and Psti) site maps.

DNA, Circular↗

PubMed1996

Body dissatisfaction among Chinese undergraduates and its implications for eating disorders in Hong Kong.

OBJECTIVES: To study the body dissatisfaction of Chinese undergraduates and its implications for eating disorders in Hong Kong. METHOD: A large sample of 1,581 subjects completed a "Body Dissatisfaction Questionnaire" (BDQ) which included 25 items about various body parts and questions on body indices, body shape dissatisfaction, and dieting. RESULTS: Whereas male subjects wanted to be taller and stronger in their upper body, the majority of female subjects felt fat in their lower body and were cognitively inclined to weigh less even though they were not obese. They desired a slimming of the stomach, thighs, waist and hip, but not the breasts. Body dissatisfaction was substantially intensified in females who reported a history of dieting in the previous year. Factor analysis of the BDQ affirmed the gender specificity and multidimensionality of body dissatisfaction. DISCUSSION: The typically "Western" pattern of body dissatisfaction has overshadowed the traditional Chinese notions of female beauty based on the face and other nontruncal features. In the context of a rapidly urbanizing Chinese society, this will predispose more females to weight control behavior and eating disorders.

Adolescent↗

PubMed1996

Disordered eating and its psychosocial correlates among Chinese adolescent females in Hong Kong.

OBJECTIVES: To study the prevalence of disordered eating and its relationship with body dissatisfaction, family dysfunction, and depression among Chinese adolescent females in Hong Kong. METHOD: Two hundred ninety-four schoolgirls completed a demographic and weight history sheet, Eating Attitudes Test-26, Body Dissatisfaction Scale, cohesion and conflict subscales of the Family Environment Scale, and the Beck Depression Inventory. RESULTS: 6.5% of subjects were EAT-26 high scores. Disordered eating was positively predicted by body dissatisfaction and, to a lesser extent, family cohesion and conflict. Body dissatisfaction was in turn positively predicted by depression, which was negatively predicted by family cohesion. DISCUSSION: Western patterns of body dissatisfaction and disordered eating attitudes are common among Chinese adolescent females. In the presence of psychosocial vulnerability factors, more weight control behavior and eating disorders may be expected to arise in Hong Kong.

Adolescent↗

PubMed1996

Cloning of m-ehk2 from the murine inner ear, an eph family receptor tyrosine kinase expressed in the developing and adult cochlea.

To identify receptor tyrosine kinases (RTKs) present in the murine inner ear, a degenerate polymerase chain reaction (PCR) methodology was employed to clone partial cDNAs encoding RTKs from embryonic day-17.5 mouse whole inner ear RNA. At least 20 distinct TKs were identified within the first 50 subcloned PCR products obtained by this analysis (Davis/Lee et al., 1996). One of the receptor RTKs identified encoded an eph-related kinase not previously described in the mouse. Analysis of full-length cDNAs revealed that this RTK is the mouse homolog of the rat ehk-2 gene product (Maisonpierre et al., 1993). Differences in the carboxyl terminal of the mouse and rat ehk2 RTKs suggest that differential splicing of this gene may occur resulting in transcripts encoding truncated and nontruncated forms of the ehk2 RTK. Multiple transcripts corresponding to this RTK were detected by Northern blot analysis only in the mouse brain. RT-PCR analysis revealed the presence of transcripts encoding this kinase in adult mouse brain, inner ear, testes, ovary, thymus, and spleen. Transcripts encoding this kinase were localized using in situ hybridization to the postembryonic day 1 cochlear ganglion neurons in the inner ear and to neurons in discrete regions of the nervous system. This is the first report of eph-related RTK in inner ear tissue that is present in both the developing and adult inner ear tissue. Because this is a member of a family of RTKs that is implicated in establishing the specificity of neuron-target cell interactions (Garrity and Zipursky, 1995), additional studies to determine if the ehk-2 gene product is involved in such processes in the murine cochlea are warranted.

Amino Acid Sequence↗

PubMed1996

A pilot study of the marginal adaptation and surface morphology of glass-cermet cements.

This study investigated changes in the marginal adaptation and surface morphology of Ketac-Silver and Chelon-Silver glass-current cements over time. Dispersalloy amalgam was used as a control. Contralateral pairs of carious primary molars were restored with the test materials and amalgam. Clinical evaluations were scheduled at 12, 18, and 24 months after placement. Gold-plated replicas of the restorations were observed with scanning electron microscopy. Fractures and cracks in the surface of the Dispersalloy and Chelon-Silver increased the surface roughness; however, the damage was superficial and self-limiting in the Dispersalloy restorations, while in Chelon-Silver the fractures caused the material to break down in layers. A substantial quantity of pores, usually smaller than 50 microns in diameter, were observed throughout the surface of the Chelon-Silver restorations. The pores in the surface of Ketac-Silver were fewer and smaller. The incidence of cavomarginal breakdown increased with time. Chelon-Silver restorations had a higher rate of cavomarginal breakdown than did Ketac-Silver and Dispersalloy restorations up to 18 months. However, there was no statistically significant difference in the marginal adaptation of the three groups at 24 months.

Cermet Cements↗

PubMed1995

Characterization of a repetitive DNA element in a brown algal virus.

We describe a family of repetitive sequences found in viruses infecting the brown alga Feldmannia sp. Previously we have demonstrated that the dsDNA genomes of viruses infecting one Feldmannia sp. isolate exist as two size classes of 160 and 179 kb. Repetitive sequences within these genomes were first demonstrated based on the anomalous hybridization among five BamHI fragments from digested virus DNA. Sequence analysis of one of those fragments, B2.4, revealed the presence of 173-bp direct repeats. The restriction maps of the cross-hybridizing BamHI fragments in the two FsV (Feldmannia sp. virus) genome size classes show that these repeats are not widely dispersed, rather they are confined to a small region of each virus genome. We estimate the number of these repeats in the 179-kb genome to be about 109 and in the 169-kb genome to be about 41. In the 179-kb genome, the repeats are contained within a 22-kb region, about 12% of that virus genome, and in the 160-kb genome the repeats are contained within a 10-kb region, about 6% of the genome. The difference in repeat numbers can account for 62% of the size difference between the two size classes of the FsV genome.

Base Sequence↗