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Biomedical subjects

J Y Lu

Publications and source records attributed to J Y Lu.

At least 37 records · Page 2Linked to original sources
PubMed2000

Increased excretions of beta2-microglobulin, IL-6, and IL-8 and decreased excretion of Tamm-Horsfall glycoprotein in urine of patients with active lupus nephritis.

Tubulointerstitial nephritis is a less frequently recognized but important complication of systemic lupus erythematosus. We have investigated the cytokine beta2-microglobulin (beta2M) and Tamm-Horsfall glycoprotein (THG) excretions in the urine of systemic lupus erythematosus patients to identify indices for evaluation of tubulointerstitial inflammation in lupus nephritis (LN). Daily urine was collected from 15 patients with active LN, from 12 patients with inactive LN, and from 17 normal subjects. The amounts of soluble interleukin (IL) 2 receptor, IL-6, IL-8, beta2M, and THG in urine were measured. Beta2M and THG were regarded as indicators of proximal and distal renal tubule function, respectively. The urinary excretions of IL-6 and IL-8 were significantly higher in patients with active LN than in those with inactive LN and in normal individuals. The excretion of soluble IL-2 receptor in all three groups of subjects was not significantly different. On the other hand, the excretion of beta2M in patients with LN was significantly higher than that in normal individuals. The excretion of beta2M in patients with active or inactive LN was not significantly different. The THG excretion was lower in patients with active LN and tubulointerstitial inflammation as compared with patients with inactive LN or normal individuals. Six patients underwent pulse cyclophosphamide therapy during the course of experiments. Five of them showed a decrease in IL-8 and IL-6 excretions in urine after the treatment. The excretions of beta2M and THG in urine, in addition to IL-6 and IL-8, can reflect the renal inflammatory activity in patients with lupus tubulointerstitial nephritis as well as in those having lupus glomerulonephritis.

Case-Control Studies↗
PubMed2000

Chronic myeloid leukemia initially presenting with spontaneous mediastinal hematoma and hemothorax.

Spontaneous mediastinal hematoma is rarely seen in hematologic malignancy. We report a case of chronic myeloid leukemia initially presenting with spontaneous hematoma and hemothorax. In addition to a detailed history, computerized tomography of the chest is important in analyzing whether an anterior mediastinal mass lesion is present. Magnetic resonance imaging is helpful in confirming the nature of a mediastinal hematoma. Trauma, vascular disease and coagulopathy should first be ruled out when making a diagnosis of spontaneous bleeding in the thorax. In our patient, the mediastinal hematoma regressed spontaneously after three months. Leukemia should be considered in the differential diagnosis of spontaneous mediastinal hematoma. In leukemia patients with spontaneous mediastinal hematoma, supportive observation and close follow-up may be better than surgery, unless massive hemorrhage or active bleeding in the thorax is suspected.

Hematoma↗
PubMed2000

Class III anti-arrhythmia drug E-4031 potentiates Na+/Ca2+ exchange current in rat ventricular myocytes.

AIM: To study the effects of E-4031 on the Na+/Ca2+ exchange currents (INa/Ca). METHODS: The quasi-steady state current-voltage relationship from the isolated rat ventricular myocytes was measured using whole-cell voltage-clamp techniques with a ramp pulse protocol. RESULTS: At potential of mV, E-4031 5, 10, and 20 mumol.L-1 increased Ni(2+)-sensitive current from (0.48 +/- 0.12), to (0.78 +/- 0.20), (0.96 +/- 0.16), and (1.15 +/- 0.13) pA/pF, respectively; tetradecanoylphorbol acetate (TPA) 50 nmol.L-1 increased Ni(2+)-sensitive current from (0.60 +/- 0.16) to (1.33 +/- 0.25) pA/pF. Tamoxifen 20 mumol.L-1 completely prevented the current changes induced by E-4031 and TPA. CONCLUSION: E-4031 stimulates the Na+/Ca2+ exchange via a protein kinase C-dependent pathway.

Animals↗
PubMed1999

Effect of the compression ratio on properties of lung surfactant (bovine lipid extract surfactant) films.

Using axisymmetric drop shape analysis (ADSA) and a captive bubble technique, the properties of lung surfactant (BLES) films under different compression ratios (i.e. the ratio of maximum to minimum surface area of the bubble) were investigated. In particular, the effect of the compression ratio of the films on the shape of the volume area surface tension-time (VAST) graphs and on the shape of the surface tension relative area (gamma-A ) graphs was examined at the air-liquid interface. Under relatively low compression ratios of the films, the VAST and gamma-A graphs indicate that the cycling is reversible (i.e. the gamma-A graphs are identical for expansion and compression). When the compression ratio of the films increases, failure tends to occur when the surface film can not support the increasing surface pressure, causing a hysteresis loop in the gamma-A graph. It was also found that low surface tension (i.e. below 5 mJ/m2) at the interface could be attained with a 30% compression ratio and collapse of the films always occurs near or below 1 mJ/m2.

Adsorption↗
PubMed1999

Genotype-phenotype correlations in neuronal ceroid lipofuscinosis due to palmitoyl-protein thioesterase deficiency.

The infantile form of neuronal ceroid lipofuscinosis (NCL) has been well studied in Finland, where there is a high carrier frequency (1:70) for a single mutation in the causative gene, CLN1, or PPT. We have recently studied a group of 29 NCL subjects in the United States with palmitoyl-protein thioesterase (PPT) deficiency and described 19 different CLN1/PPT mutations in our population. In this report, we present a review of our previous findings, including a more detailed analysis of phenotype-genotype correlations, and present previously unpublished data concerning the clinical manifestations of the disorder in children of families with multiple affected members. Our studies indicate that about half of PPT-deficient patients in the United States are very similar to Finnish infants with INCL, but that a different mutation (R151X) accounts for 40% of U.S. alleles. The Finnish mutation (R122W) is rare in the United States. The other half of U.S. PPT-deficient patients develop symptoms after the age of 2 years, much later than Finnish patients. One common mutation (the "Scottish" allele, T75P) accounts for 13% of alleles and results in a juvenile-onset phenotype that is clinically indistinguishable from JNCL with CLN3 mutations. Other rare mutations were also associated with JNCL phenotypes, such as D79G and G250V. A preliminary expression study of two of these mutant enzymes supports the conclusion that juvenile-onset NCL (JNCL with GROD) is caused by missense mutations in the PPT gene that result in mutated enzymes with residual PPT enzyme activity.

Age of Onset↗
PubMed1999

Seroprevalence of cytotoxin-associated gene A positive Helicobacter pylori strains in Changle, an area with very high prevalence of gastric cancer in south China.

BACKGROUND: Helicobacter pylori, especially the CagA-positive strains, are closely associated with peptic ulcers and gastric cancers. We performed a large scale gastric cancer screening project and examined the prevalence of H. pylori and CagA-positive strains in Changle, China, an area with one of the World's highest gastric cancer mortality. We also compared the prevalence with that in Hong Kong which has one-tenth of the gastric cancer mortality of that in Changle. METHODS: A total of 2424 subjects in Changle and 523 subjects in Hong Kong had endoscopic examination and venesection. Sera were tested for anti-H. pylori antibody and anti-CagA antibody and correlated with endoscopic findings. RESULTS: In Changle, 80. 9% of the subjects were H. pylori carriers. Out of 551 carriers, 408 (74%) were positive for anti-CagA antibody. A total of 76% and 87% of the asymptomatic and gastric cancer patients were positive for anti-CagA antibody, respectively (P > 0.05). Compared to Hong Kong, there was a significantly (P < 0.0001) higher prevalence of CagA-positive strains in asymptomatic subjects in Changle (76%) than in Hong Kong (28%), but not in peptic ulcers or gastric cancers. CONCLUSIONS: Subjects in Changle had a high prevalence of H. pylori infection and a high prevalence of the CagA-positive strains. The contrast in the prevalence of CagA-positive strains, in asymptomatic subjects in two areas with differing gastric cancer mortality, supports the pathogenic role of CagA-positive strains in gastric carcinogenesis.

Adolescent↗
PubMed1999

Differential Helicobacter pylori infection rates in two contrasting gastric cancer risk regions of South China. China Gastric Cancer Study Group.

BACKGROUND: Carriers of Helicobacter pylori are believed to have a three- to six-fold increased risk of developing gastric cancer. We have recently conducted a simultaneous cross-sectional population study on the prevalence of H. pylori infection in a cohort of asymptomatic adult volunteers in two contrasting gastric cancer risk regions of South China, Hong Kong and Changle of Fujian. Their mean annual gastric cancer mortality has been approximately 7.5 and 75/100 000 population, respectively, since the beginning of the last decade. The aim of this study was to evaluate if H. pylori prevalence bears any relationship to gastric cancer mortality rates in these two southern regions of China. METHODS: Sera were obtained from 397 volunteers in Hong Kong. They were tested for anti-H.pylori immunoglobulin (Ig) G antibody by using a commercial enzyme-linked immunosorbent assay (ELISA) kit. Volunteers of Changle (1456) had upper endoscopy examination and were also tested for anti-H. pylori IgG antibody by the same ELISA method. RESULTS: The overall H. pylori infection prevalence was significantly higher in Changle (80.4%) than in Hong Kong (58.4%; P< 0.01). The high prevalence is associated with more atrophic gastritis. The overall risk of gastric cancer in people of Changle is approximately five-fold that of Hong Kong (adjusted odds ratio 4.9, 95% CI 2.5-9.8). CONCLUSIONS: It is concluded that the prevalence of H. pylori infection rates bear a direct relationship to gastric cancer mortality rates in these two southern regions of China. Thus, H. pylori most likely plays a significant aetiopathogenetic role in gastric carcinogenesis in subjects living in Changle.

Adult↗
PubMed1999

Evaluation of cytokeratin 19 fragment (CYFRA 21-1) as a tumor marker in malignant pleural effusion.

BACKGROUND: The aim was to investigate the diagnostic utility of CYFRA 21-1 (cytokeratin 19 fragment) as a tumor marker in pleural effusion and evaluate the value of combining CYFRA 21-1 and carcinoembryonic antigen (CEA) assays as a diagnostic aid in the malignant pleural effusion. METHODS: One hundred and twenty-six patients (72 malignant and 54 benign pleural effusion) were included in this retrospective study. The effusion levels of CYFRA 21-1 and CEA were measured using radioimmunometric assay. RESULTS: The median values of CYFRA 21-1 in benign and malignant pleural effusion are 15 and 70 ng/ml, respectively. Using a cut-off value of 50 ng/ml, defined at 94% specificity, the diagnostic sensitivity of CYFRA 21-1 for non-small cell lung carcinoma (n = 61), squamous cell carcinoma (n = 21), adenocarcinoma (n = 40) and small cell lung cancer (n = 11) was 64, 71, 60 and 18%, respectively. Regardless of cell types, the diagnostic sensitivity of CYFRA 21-1 and CEA in malignant pleural effusion (n = 72) was 57 and 60%, respectively (cut-off value of 10 ng/ml in CEA assay). Combining CEA with CYFRA 21-1, the diagnostic sensitivity may increase up to 72%, which was defined at 89% specificity. CONCLUSION: CYFRA 21-1 assay may be a useful tumor marker for discriminating benign from malignant pleural effusion, especially in those of non-small cell lung cancer. The combined use of CEA and CYFRA 21-1 assay in the malignant effusion may increase the diagnostic yield compared with CEA or CYFRA 21-1 alone.

Antigens, Neoplasm↗
PubMed1999

Intrathoracic extramedullary haematopoiesis complicated by massive haemothorax in alpha-thalassaemia.

Intrathoracic extramedullary haematopoiesis (EMH) is a rare entity that is usually asymptomatic. A 44 year old man with alpha-thalassaemia is described who developed dyspnoea and massive left sided haemothorax. The haemoglobin disorder was established by Hgb H staining and haemoglobin electrophoretic studies. The DNA analysis revealed it to be a case of double heterozygous terminal codon mutation with the genotype alphaalphaCS/alphaalphaT. Computed tomographic scanning and magnetic resonance imaging of the thorax showed multiple paravertebral masses which were found by thoracoscopic biopsy to be extramedullary haematopoiesis. Although no additional sclerosing pleurodesis or low dose radiation therapy was given, the lung expanded well and there has been no recurrence of haemothorax to date.

Adult↗
PubMed1999

Folate-targeted enzyme prodrug cancer therapy utilizing penicillin-V amidase and a doxorubicin prodrug.

In antibody-targeted enzyme prodrug therapy, a monoclonal antibody (mAb) covalently linked to an enzyme is commonly exploited to concentrate the enzyme on the tumor cell surface prior to administration of a relatively nontoxic prodrug. The tumor-localized enzyme then converts the prodrug into a cytotoxic agent, which in turn diffuses into the tumor causing localized cell death. In this paper, we have substituted folic acid for the mAb as a mean of delivering an attached enzyme, penicillin-V amidase (PVA), to folate receptor (FR)-positive tumor cells. The enzyme PVA is capable of converting a doxorubicin-N-p-hydroxyphenoxyacetamide prodrug (DPO) into its potent parent drug, doxorubicin. For PVA targeting, each PVA molecule was covalently labeled with three molecules of folic acid via the formation of amide bonds. In vitro binding assays showed that folate-PVA-125I conjugates bind specifically to KB cells (FR-positive tumor cells) but not to A549 cells (FR-negative tumor cells). Moreover, in a series of in vitro cytotoxicity tests, folate-PVA conjugates were found to kill folate receptor positive but not receptor negative cells, and when bound to FR-positive cells, folate-PVA conjugates rendered the DPO prodrug as toxic as free doxorubicin (IC50, approximately 0.6 microM). Finally, preliminary in vivo plasma clearance studies in normal mice revealed that i.v. administered folate-PVA-125I and PVA-125I are both cleared from the blood within a 24 h time period, removing concern that nonspecifically trapped folate-PVA might activate prodrug in nontargeted tissues. In view of the fact that only a small number of folate-PVA molecules are required to mediate killing of target cells in vitro, these data argue that folate-targeted enzyme prodrug therapy should be considered for tumor eradication in vivo.

Animals↗
PubMed1999

Small cell lung carcinoma associated with paraneoplastic limbic encephalitis.

Limbic encephalitis is an unusual presentation of paraneoplastic syndrome. We report a case of small cell lung carcinoma associated with limbic encephalitis. A 67-year-old man presented with convulsions, memory impairment, and neuropsychiatric disturbances as initial symptoms. Subsequently, small cell lung carcinoma was diagnosed by bronchoscopic biopsy. The cerebrospinal fluid studies, electroencephalography, and magnetic resonance imaging findings had distinctive features compatible with paraneoplastic limbic encephalitis. The neuropsychiatric symptoms improved significantly after six cycles of systemic chemotherapy and adjuvant radiotherapy, resulting in partial remission of the tumor. A follow-up computed tomography scan of the head showed no evidence of intracranial metastasis 7 months after the diagnosis of cancer. Limbic encephalitis may be an initial manifestation of lung cancer. Greater awareness for diagnosis and early treatment of the primary tumor offers the best chance for improvement in patients with lung cancer presenting with limbic encephalitis.

Aged↗
PubMed1999

Ethambutol-induced psychosis: a case report.

Clinically, ethambutol (EMB)-induced psychosis is rare. In our review of the literature, most cases of antituberculosis agent-associated psychoses were caused by isoniazid (INH). We report the case of a 51-year-old man with suspected tuberculosis (TB) pleurisy. An anti-TB trial with INH, rifampicin and EMB was given initially. Dizziness, disorientation, and auditory and visual hallucinations developed after seven days of therapy. Laboratory examinations, including routine biochemistry tests, serum titer of antinuclear antibodies, cerebrospinal fluid analysis and computerized tomography of the head showed no abnormal findings. Following discontinuation of anti-TB agents, the psychiatric symptoms subsided. When the patient was challenged with EMB, the same psychiatric symptoms recurred, but resolved again after discontinuation of EMB. It is important to be aware that EMB can induce psychosis when anti-TB medications are prescribed.

Antitubercular Agents↗
PubMed1999

Na+/Ca2+ exchange current in myocytes isolated from rat hypertrophied heart.

Effects of myocardial hypertrophy on the Na+/Ca2+ exchange current in isolated rat cardiac myocytes were investigated, using whole cell patch techniques. Goldblatt 2-kidney, one-clip technique was used to induce cardiomyocyte hypertrophy. The results demonstrated that the Ni(2+)-sensitive Na+/Ca2+ exchange current density was larger in hypertrophied cells than that in normal cells. At a holding potential of mV, the outward current densities were 1.53 +/- 0.31 pA/pF in normal cells and 2.62 +/- 0.53 pA/pF in hypertrophied cells (P < 0.01). At a holding potential of -100 mV, the inward current densities were 0.42 +/- 0.14 pA/pF in normal cells and 1.12 +/- 0.33 pA/pF in hypertrophied cells (P < 0.001). The results suggest that during myocardial hypertrophy the Na+/Ca2+ exchange current is significantly increased.

Animals↗
PubMed1998

Molecular genetics of palmitoyl-protein thioesterase deficiency in the U.S.

Mutations in a newly described lysosomal enzyme, palmitoyl-protein thioesterase (PPT), were recently shown to be responsible for an autosomal recessive neurological disorder prevalent in Finland, infantile neuronal ceroid lipofuscinosis. The disease results in blindness, motor and cognitive deterioration, and seizures. Characteristic inclusion bodies (granular osmiophilic deposits [GROD]) are found in the brain and other tissues. The vast majority of Finnish cases are homozygous for a missense mutation (R122W) that severely affects PPT enzyme activity, and the clinical course in Finnish children is uniformly rapidly progressive and fatal. To define the clinical, biochemical, and molecular genetic characteristics of subjects with PPT deficiency in a broader population, we collected blood samples from U.S. and Canadian subjects representing 32 unrelated families with neuronal ceroid lipofuscinosis who had GROD documented morphologically. We measured PPT activity and screened the coding region of the PPT gene for mutations. In 29 of the families, PPT deficiency was found to be responsible for the neurodegenerative disorder, and mutations were identified in 57 out of 58 PPT alleles. One nonsense mutation (R151X) accounted for 40% of the alleles and was associated with severe disease in the homozygous state. A second mutation (T75P) accounted for 13% of the alleles and was associated with a late onset and protracted clinical course. A total of 19 different mutations were found, resulting in a broader spectrum of clinical presentations than previously seen in the Finnish population. Symptoms first appeared at ages ranging from 3 mo to 9 yr, and about half of the subjects have survived into the second or even third decades of life.

Adolescent↗
PubMed1998

Characteristics and composition of peanut oil prepared by an aqueous extraction method.

Peanut is one of the crops being tested for NASA's Advanced Life Support (ALS) program for future long-duration human space missions. The ALS program is developing an integrated system for biomass (food, oxygen) production and resource recycling. Oil will be used mainly for cooking and its availability is important for food preparation. Peanut seeds contain 40-50% oil and hence are considered an excellent source of oil. In the ALS environment, a simple, compact, and energy-efficient system is needed. The feasibility of such a method, peanut oil preparation by water extraction, was investigated. The results indicated the important processing conditions to be: a peanut particle size of 0.02 cm or less, a pH of 4, simmering for 20 min plus churning at 65 degrees C for a few hours, and a centrifugation at 6000 x gn to separate the oil. The oil recovery yield was about 80%. The saponification value, specific gravity, refractive index, and viscosity were similar to that of commercial peanut oil except the color was lighter for the water-extracted oil. Gas and thin-layer chromatographic analyses showed that fatty acid and lipid profiles were similar to the commercial peanut oil. The only difference observed was that the oil prepared by the aqueous method had lower linoleic and higher oleic acids than the commercial peanut oil. The oil prepared by this aqueous method appeared to be of high quality.

Arachis↗
PubMed1998

Consumer acceptance of vegetarian sweet potato products intended for space missions.

Sweet potato is one of the crops selected for NASA's Advanced Life Support Program for potential long-duration lunar/Mars missions. This article presents recipes of products made from sweet potato and determines the consumer acceptability of products containing from 6% to 20% sweet potato on a dry weight basis. These products were developed for use in nutritious and palatable meals for future space explorers. Sensory evaluation (appearance/color, aroma, texture, flavor/taste, and overall acceptability) studies were conducted to determine the consumer acceptability of vegetarian products made with sweet potato using panelists at NASA/Johnson Space Center in Houston, TX. None of these products including the controls, contained any ingredient of animal origin with the exception of sweet potato pie. A 9-point hedonic scale (9 being like extremely and 1 being dislike extremely) was used to evaluate 10 products and compare them to similar commercially available products used as controls. The products tested were pancakes, waffles, tortillas, bread, pie, pound cake, pasta, vegetable patties, doughnuts, and pretzels. All of the products were either liked moderately or liked slightly with the exception of the sweet potato vegetable patties, which were neither liked nor disliked. Mean comparisons of sensory scores of sweet potato recipes and their controls were accomplished by using the Student t-test. Because of their nutritional adequacy and consumer acceptability, these products are being recommended to NASA's Advanced Life Support Program for inclusion in a vegetarian menu plan designed for lunar/Mars space missions.

Diet, Vegetarian↗
PubMed1998

Sweet potato in a vegetarian menu plan for NASA's Advanced Life Support Program.

Sweet potato has been selected as one of the crops for NASA's Advanced Life Support Program. Sweet potato primarily provides carbohydrate--an important energy source, beta-carotene, and ascorbic acid to a space diet. This study focuses on menus incorporating two sets of sweet potato recipes developed at Tuskegee University. One set includes recipes for 10 vegetarian products containing fom 6% to 20% sweet potato on a dry weight basis (pancakes, waffles, tortillas, bread, pie, pound cake, pasta, vegetable patties, doughnuts, and pretzels) that have been formulated, subjected to sensory evaluation, and determined to be acceptable. These recipes and the other set of recipes, not tested organoleptically, were substituted in a 10-day vegetarian menu plan developed by the American Institute of Biological Sciences (AIBS) Kennedy Space Center Biomass Processing Technical Panel. At least one recipe containing sweet potato was included in each meal. An analysis of the nutritional quality of this menu compared to the original AIBS menu found improved beta-carotene content (p<0.05). All other nutrients, except vitamin B6, and calories were equal and in some instances greater than those listed for NASA's Controlled Ecological Life Support Systems RDA. These results suggest that sweet potato products can be used successfully in menus developed for space with the added benefit of increased nutrient value and dietary variety.

Diet, Vegetarian↗