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Biomedical subjects

C M Lee

Publications and source records attributed to C M Lee.

At least 91 records · Page 5Linked to original sources
PubMed1999

Dual kidney transplantation: older donors for older recipients.

BACKGROUND: Dual kidney transplantation, the transplantation of both donor kidneys into a single recipient, allows increased use of expanded criteria donors (eg, older donors with a history of hypertension) to alleviate the disparity between available donors and potential recipients. We evaluated outcomes in our dual kidney transplant program that started in 1995. STUDY DESIGN: A retrospective comparison of donor and recipient data between recipients of dual (n = 41) versus single (n = 199) cadaveric renal transplants from February 1, 1995, to March 22, 1998, was performed. Dual kidney transplantation was selectively performed when the calculated donor admission creatinine clearance was less than 90 mL/min and the donor age was greater than 60 years, or if the donor had an elevated terminal serum creatinine. Every attempt was made to age- and size-match the donor and recipients. RESULTS: Recipients of dual kidneys had donors who were older than single kidney donors (59 +/- 12 versus 42 +/- 17 years respectively, p < 0.0001) and had more hypertension (51% versus 29%, p = 0.024). Average urine output was lower in the dual versus single kidney group (252 +/- 157 versus 191 +/- 70 mL/hr, p = 0.036). Donors for dual kidney recipients had a lower donor admission creatinine clearance of 82 +/- 28 mL/min versus 105 +/- 45 mL/min in the single kidney group (p = 0.005). Recipients of dual versus single kidneys were older (58 +/- 11 versus 47 +/- 12 years, p > 0.0001). Dual versus single kidney recipients had similar serum creatinines up to 2 years posttransplant (1.6 +/- 0.3 versus 1.6 +/- 0.7 mg/dL at 2 years, p = NS) and a comparable incidence of delayed graft function (24% versus 33%, p = NS) and 3-month posttransplant creatinine clearance (54 +/- 23 versus 57 +/- 25 mL/min, p = NS). One-year patient and graft survival for single kidney transplantation was 97% and 90%, respectively, and 98% and 89% for dual kidney transplantation (p = NS). CONCLUSIONS: Dual kidney donors were significantly older, had more hypertension, lower urine outputs, and lower donor admission creatinine clearance. Despite these differences, dual kidney recipients had comparable postoperative function, outcomes, and survival versus single kidney recipients. We believe selective use of dual kidney transplantation can provide excellent outcomes to recipients of kidneys from older donors with reduced renal function.

Adult↗
PubMed1999

Production of seafood flavor from red hake (Urophycis chuss) by enzymatic hydrolysis.

Protein hydrolysates were prepared as a natural flavor stock from the red hake (Urophycis chuss) headed-gutted (H&G) mince and frame mince using commercial enzymes, Flavourzyme and Savorase, at the natural pH of fish (6.8) and the water/fish ratio of 2:5. The addition of 1.5% NaCl and 0.4% STPP improved the flavor quality of the hydrolysate by masking bitterness and off-flavor. A 6 h hydrolysis of H&G mince with Flavourzyme yielded a hydrolysate of the highest acceptability. Hydrolysis increased the concentration of most free amino acids except Arg and His. Leu, Lys, and Arg were predominant free amino acids in the hydrolysates, whereas Leu and Arg were major ones in the cooking juice. The concentration of Glu responsible for umami taste was increased by 6-9 times upon hydrolysis. Hydrolysates contained higher percentages of free amino acids giving both umami and sweet tastes than did cooking juice.

Amino Acids↗
PubMed1999

Review of animal models in carotenoid research.

Foods containing provitamin A carotenoids are the primary source of vitamin A in many countries, despite the poor bioavailability of carotenoids. In addition, epidemiologic studies suggest that dietary intake of carotenoids influences the risk for certain types of cancer, cardiovascular disease and other chronic diseases. Although it would be ideal to use humans directly to answer critical questions regarding carotenoid absorption, metabolism and effects on disease progression, appropriate animal models offer many advantages. This paper will review recent progress in the development of animal models with which to study this class of nutrients. Each potential model has strengths and weaknesses. Like humans, gerbils, ferrets and preruminant calves all absorb beta-carotene (betaC) intact, but only gerbils and calves convert betaC to vitamin A with efficiency similar to that of humans. Mice and rats efficiently convert betaC to vitamin A but absorb carotenoids intact only when they are provided in the diet at supraphysiologic levels. Mice, rats and ferrets can be used to study cancer, whereas primates and gerbils are probably more appropriate for studies on biomarkers of heart disease. No one animal model completely mimics human absorption and metabolism of carotenoids; thus the best model must be chosen with consideration of the specific application being studied, characteristics of the model, and the available funding and facilities.

Animals↗
PubMed1999

Biomass conversion to mixed alcohol fuels using the MixAlco process.

The MixAlco process is a patented technology that converts any biodegradable material (e.g., sorted municipal solid waste, sewage sludge, industrial biosludge, manure, agricultural residues, energy crops) into mixed alcohol fuels containing predominantly 2-propanol, but also higher alcohols up to 7-tridecanol. The feedstock is treated with lime to increase its digestibility. Then, it is fed to a fermentor in which a mixed culture of acid-forming microorganisms produces carboxylic acids. Calcium carbonate is added to the fermentor to neutralize the acids to their corresponding carboxylate salt. The dilute (approximately 3%) carboxylate salts are concentrated to 19% using an amine solvent that selectively extracts water. Drying is completed using multi-effect evaporators. Finally, the dry salts are thermally converted to ketones which subsequently are hydrogenated to alcohols. All the steps in the MixAlco process have been proven at the laboratory scale. A techno-economic model of the process indicates that with the tipping fees available in New York (126 dollars/dry tonne), mixed alcohol fuels may be sold for 0.04 dollars/L (0.16 dollars/gal) with a 60% return on investment (ROI). With the average tipping fee in the United States rates (63 dollars/dry tonne), mixed alcohol fuels may be sold for 0.18 dollars/L (0.69 dollars/gal) with a 15% ROI. In the case of sugarcane bagasse, which may be obtained for about 26 dollars/dry ton, mixed alcohol fuels may be sold for 0.29 dollars/L (1.09 dollars/gal) with a 15% ROI.

Journal Article↗
PubMed1999

Evaluation of the completeness of cancer case ascertainment in the Seoul male cohort study: application of the capture-recapture method.

Since the completeness of case ascertainment is directly related to the validity of a study, the evaluation of completeness is an essential feature of a cohort study. To estimate the completeness of cancer case ascertainment during a three year period (Jan. 1, 1993, to Dec. 31, 1995) in which the Seoul Male Cohort was followed up, we applied capture-recapture method. Data were obtained from the cancer registries, medical records and death certificates, with cases identified from each source numbering 103, 105, and 38, respectively. After eliminating duplicate cases, the total number was 141, and by using a log-linear model, the number of cases not detected by any of the three data sources was estimated to be 16. For all cancers, the estimated completeness of follow-up was 89.9%.

Adult↗
PubMed1999

Hepatic abscess due to gastric perforation by ingested fish bone demonstrated by computed tomography.

Perforation of the gastrointestinal tract by ingested foreign bodies is rare. Preoperative diagnosis of complications due to foreign bodies in the gastrointestinal tract can rarely be achieved because the conventional radiographic appearance is nonspecific. This report describes a 69-year-old woman who presented with vague clinical manifestations, intermittent abdominal pain, and low-grade fever. Hepatic abscess, secondary to a foreign body penetrating the gastric wall, was diagnosed preoperatively using computed tomography findings. On exploration, the foreign body turned out to be a fish bone. The abscess was confirmed and drained during surgery and a partial gastrectomy was performed. This case illustrates the value of CT in the evaluation of this condition.

Aged↗
PubMed1999

Development and proliferation of Trypanosoma musculi in the presence of adherent splenic cells.

The development and proliferation of Trypanosoma musculi parasites were studied in vitro in the presence of adherent splenic cells. The parasites grew and proliferated only when attached by their flagellar tips to adherent splenic cells. Analyses of excretory-secretory products of the adherent cells-parasites did not indicate any detectable soluble growth factor that might be responsible for the growth of these trypanosomes. During the proliferation, the kinetoplast migrated toward the nucleus, and once in the vicinity of the nucleus, nuclear division was triggered. The nucleus and kinetoplast divided at the same time Trypanosoma musculi parasites started dividing from their flagellar ends, and daughter cells were formed within 48 hr. In the absence of adherent splenic cells in vitro, the parasites were transformed into round nonviable forms.

Animals↗
PubMed1999

Congenital hepatic arterioportal fistula complicated with gastrointestinal bleeding treated with transcatheter embolization: case report.

Congenital hepatic arterioportal fistula (HAVF) is extremely rare in children. We present a patient with congenital hepaticoportal arteriovenous fistula complicated with gastrointestinal bleeding treated using transcatheter arterial embolization. Our patient was the youngest (2 days old) case ever reported with congenital HAVF and the first one to receive arterial embolization for HAVF during childhood. The 3-year-old girl was suggested of having congenital HAVF using Doppler ultrasonography. However, her family refused further investigation, and she was lost to follow-up. Three years later, she was sent to our hospital due to melaena. Repeated ultrasonography revealed dilated intrahepatic portal vein with arterial flow demonstrated using Doppler imaging. No esophageal varices or gastric or duodenal ulcer was seen during endoscopy. Angiography showed a HAVF and transcatheter embolization was done simultaneously. Follow-up at one and two weeks post-embolization revealed no more shunt flow within the portal vein, though cystic like dilatation of the portal vein persisted, and no thrombosis was observed. This case emphasizes that transcatheter arterial embolization can be easily and successfully used for treating childhood congenital HAVF. Abnormal dilatation of the portal vein in children needs doppler evaluation and possibly angiography.

Arteriovenous Fistula↗
PubMed1999

The CNS midline cells and spitz class genes are required for proper patterning of Drosophila ventral neuroectoderm.

The Drosophila embryonic central nervous system (CNS) develops from sets of neuroblasts (NBs) which segregate from the ventral neuroectoderm during early embryogenesis. It is not well established how each individual NB in the neuroectoderm acquires its characteristic identity along the dorsal-ventral axis. Since it is known that CNS midline cells and spitz class genes (pointed, rhomboid, single-minded, spitz and Star) are required for the proper patterning of ventral CNS and epidermis originated from the ventral neuroectoderm, this study was carried out to determine the functional roles of the CNS midline cells and spitz class genes in the fate determination of ventral NBs and formation of mature neurons and their axon pathways. Several molecular markers for the identified NBs, neurons, and axon pathways were employed to examine marker gene expression profile, cell lineage and axon pathway formation in the spitz class mutants. This analysis showed that the CNS midline cells specified by single-minded gene as well as spitz class genes are required for identity determination of a subset of ventral NBs and for formation of mature neurons and their axon pathways. This study suggests that the CNS midline cells and spitz class genes are necessary for proper patterning of the ventral neuroectoderm along the dorsal-ventral axis.

Animals↗
PubMed1999

Precipitation of calcium oxalate monohydrate at phospholipid monolayers.

Studies of calcium oxalate monohydrate (COM) precipitation at Langmuir monolayers of the phospholipids dipalmitoylphosphatidylglycerol (DPPG), dipalmitoylphosphatidylcholine (DPPC), and dipalmitoylphosphatidylserine (DPPS) are reported. The precipitation is heterogeneous and selective, with a majority of crystals orienting with the COM (101) face toward the monolayer interface for each phospholipid. The number density of COM crystals depends on the identity of the phospholipid monolayer, decreasing in the order DPPG > DPPS > DPPC. It was also found that COM precipitation increases as the surface pressure of the monolayer is lowered and with the addition of low levels (<0.1%) of cholesterol. The possibility that changes in monolayer fluidity influence COM attachment is discussed.

Calcium Oxalate↗
PubMed1999

Investigation of an outbreak of Pseudomonas putida using antimicrobial susceptibility patterns, pulsed-field gel electrophoresis of genomic DNA and restriction fragment length polymorphism of PCR-amplified rRNA operons.

Seventeen Pseudomonas putida isolates were investigated which were collected from the urine specimens of 14 patients and one reflectrometer by comparing antimicrobial susceptibility patterns, pulsed-field gel electrophoresis (PFGE) of genomic DNA, and restriction fragment length polymorphism (RFLP) of PCR-amplified rRNA operons. Three susceptibility patterns were defined by testing 22 antimicrobial agents, with 14 isolates resistant to all agents. PFGE of XbaI-genomic DNA fragments divided the 17 isolates into 9 distinct types. One type, seen in 6 isolates showing identical patterns of approximately 35 fragments of 10 to 350 kb, was defined as the outbreak strain. Another 4 types, in a total of 6 isolates, were considered closely related to the outbreak strain; 2 types in 1 isolate each were possibly related to the outbreak strain; and 2 types in a total of 3 isolates were different from the outbreak strain. All 12 outbreak or closely related isolates were from patients in the surgical intensive care unit and a surgical ward, and were different from isolates in other wards, clearly indicating an outbreak of P. putida. Only two types were defined by the RFLP of 4.5 kb PCR-amplified rRNA operons; one type was seen in 15 isolates, while the other was seen in only 2 isolates. In conclusion, PFGE of genomic DNA is a highly discriminatory and reproducible method for epidemiological typing of P. putida.

DNA, Bacterial↗
PubMed1999

Susceptibility testing and clinical effect of fusidic acid in oxacillin-resistant Staphylococcus aureus infections.

One hundred and six oxacillin-resistant Staphylococcus aureus (ORSA) isolates collected from various clinical specimens at Mackay Memorial Hospital during the period from 1997 to 1998 were tested. The MICs of fusidic acid against ORSA isolates were in the range of 0.06 microgram/mL to 4 micrograms/mL. There was only one ORSA isolate (0.9%) resistant to fusidic acid in this study. Twenty-four patients with ORSA infection were enrolled into the study between July 1997 to June 1998. Four patients without the evidence of sepsis received oral fusidic acid only. The other 20 patients with sepsis received intravenous glycopeptide first, and then the oral fusidic acid for 7 to 10 days. Oral fusidic acid was used for mild ORSA infection and achieved satisfactory clinical outcome. In severe ORSA infection, it was found that sequential therapy with fusidic acid had relapsed in three patients. We concluded that oral fusidic acid achieved a satisfactory outcome in our patients with mild ORSA infection. In such cases, fusidic acid may provide an effective alternative treatment of choice. The rare side effect of granulocytopenia and jaundice was noted in our case series. The side effect may be not so rare as previously thought, if it had been carefully looked for.

Adult↗
PubMed1999

Psoas abscess: a 10 year review.

Psoas muscle abscesses are rarely encountered yet, and pose diagnostic and therapeutic challenges because of nonspecific clinical presentations. We retrospectively reviewed the medical records of adults with a psoas muscle abscess who were admitted to our hospital from January, 1988 to May, 1998. Over this ten year period, psoas abscesses were found in 11 cases. Six cases were primary and Staphylococcus spp. was the most commonly isolated. Five cases were a secondary psoas abscess while urological problems were the most common underlying condition. Fever, chills, lower back or flank pain and a palpable mass were the most common manifestations. Only one patient presented the classic triad of fever, flank pain, and limitation of hip movement (a typical psoas sign). Leukocytosis was the most common laboratory finding. Two of 11 cases presented septic shock. Two patients were admitted to the hospital with the initial diagnosis of psoas abscesses. Computerized tomographic (CT) scans accurately confirmed the clinical diagnosis in 9 of 11 patients. Diagnosis was then established one each by ultrasound (US) and magnetic resonance imaging (MRI), respectively. Four of 11 patients had negative findings initially by US. All patients were managed with drainage and antibiotics, nine were drained surgically, and two were managed with percutaneous drainage under CT guidance. Two patients died. Because of the lack of the classic symptoms and signs in most cases, a high degree of suspicion is important for early diagnosis of psoas abscess. CT scan is the standard technique of diagnosis. The prognosis is generally good with appropriate antibiotic treatment and complete drainage.

Adult↗
PubMed1998

Molecular epidemiology and trends of HIV-1 subtypes in Taiwan.

To understand the trends of distribution and risk factors associated with different HIV-1 subtypes in different populations in Taiwan, blood samples and questionnaires were collected from 267 male and 21 female HIV-1-infected people in a multicenter survey from 1993 to 1996. This group represented about one quarter of the total registered HIV-1 cases in Taiwan. The HIV-1 subtypes were determined using V3-based peptide-enzyme immunoassays complemented by heteroduplex mobility assay and phylogenetic tree analysis. The results showed that in Taiwan, men were primarily infected with HIV-1B (68.2%) and HIV-1E (27.3%), whereas women were mainly infected with non-B subtypes (4.8% A, 4.8% C, 71.4% E, and 9.5% G). In addition, 71.4% of men with HIV-1B were homosexual or bisexual, whereas 56.2% of men with HIV-1E were heterosexual (p < .001). Although HIV-1E subtype came to Taiwan later than HIV-1B, it has become a major subtype in the heterosexual population.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Influences of caloric restriction on age-associated skeletal muscle fiber characteristics and mitochondrial changes in rats and mice.

The effect of caloric restriction (CR) initiated in adult rats (17 months of age) on the abundance of deleted mitochondrial genomes, mitochondrial enzymatic abnormalities, and fiber number was examined in rat skeletal muscle. Vastus lateralis muscle from young (3-4 months) ad libitum-fed, old (30-32 months) restricted (35% and 50% CR, designated CR35 and CR50, respectively), and old ad libitum-fed rats (29 months) was studied. CR preserved fiber number and fiber-type composition in the CR50 rats. In the old rats from all groups, individual fibers were found with either no detectable cytochrome-c oxidase activity (COX-), hyperactive for succinate dehydrogenase activity (SDH++), or both COX- and SDH++. Muscle from the CR50 rats contained significantly fewer COX- and SDH++ fibers than did the muscle from the CR35 rats. CR50 rats also had significantly lower numbers of mtDNA deletion products in two (adductor longus and soleus) of the four muscles examined compared to CR35 rats. These data indicate that CR begun in late middle age can retard age-associated fiber loss and fiber-type changes as well as lower the number of skeletal muscle fibers exhibiting mitochondrial enzyme abnormalities. CR can also decrease the accumulation of deleted mitochondrial genomes.

Aging↗
PubMed1998

Association of age-related mitochondrial abnormalities with skeletal muscle fiber atrophy.

The hypothesis that mitochondrial dysfunction contributes to the senescent loss of skeletal muscle was investigated in quadriceps from 2- to 39-year old rhesus monkeys. Histological approaches, both cross-sectional (a single cross-section of the muscle) and longitudinal (multiple cross-sections of individual fibers spanning a 350-1600 microm region), were used to identify muscle fibers with abnormal mitochondrial electron transport system (ETS) enzyme activities and mitochondrial DNA deletions. Fibers were examined for two ETS activities, succinate dehydrogenase (SDH, ETS complex II) and cytochrome c oxidase (COX, ETS complex IV). The number of individual fibers containing ETS abnormalities (predominately negative for cytochrome c oxidase activity and/or hyperreactive for succinate dehydrogenase) increased with age. Deletions of the mitochondrial genome were observed in 89% of these ETS abnormal fibers. Longitudinal analysis allowed characterization of the ETS abnormal phenotype along their length. A decrease in cross-sectional area in 14% of the ETS abnormal fibers supports the hypothesis that deleted mitochondrial genomes may contribute to age-related fiber atrophy.

Aging↗