PubMed Health⌕ Search

Biomedical subjects

P W Li

Publications and source records attributed to P W Li.

At least 19 recordsLinked to original sources
PubMed2001

Overexpression, purification, crystallization and preliminary X-ray diffraction analysis of Cu,Zn superoxide dismutase from Peking duck.

The cDNA encoding Peking duck Cu,Zn superoxide dismutase (dSOD) was cloned and sequenced. The recombinant enzyme was overexpressed in Escherichia coli, purified to homogeneity and crystallized using the sitting-drop vapour-diffusion technique. Trigonal crystals of dSOD were obtained at 278 K at low ionic strength and around neutral pH. These crystals belong to space group P3(2)21, with unit-cell parameters a = 124.4, c = 163.5 A, gamma = 120 degrees. The asymmetric unit contains four dimers (eight monomers of Cu,Zn dSOD) and has a 56% solvent content, with a V(M) of 2.8 A(3) Da(-1). On a Rigaku R-AXIS IIc image-plate area-detector system, the crystal diffracted to 2.9 A. Unusual supermolecular double-helix packing with 9(2)2 non-crystallographic symmetry in crystals has been observed in the initial structural analysis.

Amino Acid Sequence↗
PubMed2001

The sequence of the human genome.

A 2.91-billion base pair (bp) consensus sequence of the euchromatic portion of the human genome was generated by the whole-genome shotgun sequencing method. The 14.8-billion bp DNA sequence was generated over 9 months from 27,271,853 high-quality sequence reads (5.11-fold coverage of the genome) from both ends of plasmid clones made from the DNA of five individuals. Two assembly strategies-a whole-genome assembly and a regional chromosome assembly-were used, each combining sequence data from Celera and the publicly funded genome effort. The public data were shredded into 550-bp segments to create a 2.9-fold coverage of those genome regions that had been sequenced, without including biases inherent in the cloning and assembly procedure used by the publicly funded group. This brought the effective coverage in the assemblies to eightfold, reducing the number and size of gaps in the final assembly over what would be obtained with 5.11-fold coverage. The two assembly strategies yielded very similar results that largely agree with independent mapping data. The assemblies effectively cover the euchromatic regions of the human chromosomes. More than 90% of the genome is in scaffold assemblies of 100,000 bp or more, and 25% of the genome is in scaffolds of 10 million bp or larger. Analysis of the genome sequence revealed 26,588 protein-encoding transcripts for which there was strong corroborating evidence and an additional approximately 12,000 computationally derived genes with mouse matches or other weak supporting evidence. Although gene-dense clusters are obvious, almost half the genes are dispersed in low G+C sequence separated by large tracts of apparently noncoding sequence. Only 1.1% of the genome is spanned by exons, whereas 24% is in introns, with 75% of the genome being intergenic DNA. Duplications of segmental blocks, ranging in size up to chromosomal lengths, are abundant throughout the genome and reveal a complex evolutionary history. Comparative genomic analysis indicates vertebrate expansions of genes associated with neuronal function, with tissue-specific developmental regulation, and with the hemostasis and immune systems. DNA sequence comparisons between the consensus sequence and publicly funded genome data provided locations of 2.1 million single-nucleotide polymorphisms (SNPs). A random pair of human haploid genomes differed at a rate of 1 bp per 1250 on average, but there was marked heterogeneity in the level of polymorphism across the genome. Less than 1% of all SNPs resulted in variation in proteins, but the task of determining which SNPs have functional consequences remains an open challenge.

Algorithms↗
PubMed2001

[Clinical observation of music therapy combined with anti-tumor drugs in treating 116 cases of tumor patients].

OBJECTIVE: To observe the clinical effect of music therapy in treating tumor patients. METHODS: Music therapy combined with anti-tumor drugs, including chemotherapy and Chinese drugs, was given to 162 tumor patients according to syndrome differentiation to observe the change of self-rating depression scale (SDS), self-rating anxiety scale (SAS), minnesota multiphasic personality inventory (MMPI), Hamilton rating scale for depression (HAMD) and T lymphocyte subsets (immuno-histochemical assay), NK cell anti-tumor activity (NAG method), etc. while 46 caces didn't receive music therapy were taken as the control group. RESULTS: The scale marks of SDS and SAS of the treated group after treatment were obviously lower than that of the control group significantly (P < 0.05, P < 0.01). After treatment, the average values of MMPI on falseness (F), hypochondriasis (HS), depression (D) and psychosthenia (Pt) in the treated group were all improved (P < 0.01 or P < 0.05); but in the control group, significant difference only showed in MMPI on HS (P < 0.05). HAMD in the treated group revealed some improvement in insomnia, early awakening, daily work and interest, systemic symptoms and hypochondriasis (P < 0.05), and significant improvement in depression, difficulty in falling asleep, psychiatric anxiety and somatic anxiety (P < 0.01); while in the control group, only work interest and HS had some improvement (P < 0.05). CD8 percent was reduced in both groups after treatment (P < 0.01), but in the treated group CD3, CD4 and CD4/CD8 ratio were not significantly changed after treatment (P > 0.05); while in the control group they lowered obviously (P < 0.05). As for NK cell anti-tumor activity in the treated group before and after treatment, it was not significantly lowered (P > 0.05); while in the control group the lowering after treatment was significant (P < 0.05). CONCLUSION: Music therapy could regulate the emotion of tumor patient, optimize the emotional effect, improve the somatic symptoms, enhance the immune function, motivate the active principle and raise the self-regulating power in the body.

Adult↗
PubMed2000

The genome sequence of Drosophila melanogaster.

The fly Drosophila melanogaster is one of the most intensively studied organisms in biology and serves as a model system for the investigation of many developmental and cellular processes common to higher eukaryotes, including humans. We have determined the nucleotide sequence of nearly all of the approximately 120-megabase euchromatic portion of the Drosophila genome using a whole-genome shotgun sequencing strategy supported by extensive clone-based sequence and a high-quality bacterial artificial chromosome physical map. Efforts are under way to close the remaining gaps; however, the sequence is of sufficient accuracy and contiguity to be declared substantially complete and to support an initial analysis of genome structure and preliminary gene annotation and interpretation. The genome encodes approximately 13,600 genes, somewhat fewer than the smaller Caenorhabditis elegans genome, but with comparable functional diversity.

Animals↗
PubMed2000

Comparative genomics of the eukaryotes.

A comparative analysis of the genomes of Drosophila melanogaster, Caenorhabditis elegans, and Saccharomyces cerevisiae-and the proteins they are predicted to encode-was undertaken in the context of cellular, developmental, and evolutionary processes. The nonredundant protein sets of flies and worms are similar in size and are only twice that of yeast, but different gene families are expanded in each genome, and the multidomain proteins and signaling pathways of the fly and worm are far more complex than those of yeast. The fly has orthologs to 177 of the 289 human disease genes examined and provides the foundation for rapid analysis of some of the basic processes involved in human disease.

Animals↗
PubMed1998

GDB: the Human Genome Database.

The Genome Database (GDB, http://www.gdb.org ) is a public repository of data on human genes, clones, STSs, polymorphisms and maps. GDB entries are highly cross-linked to each other, to literature citations and to entries in other databases, including the sequence databases, OMIM, and the Mouse Genome Database. Mapping data from large genome centers and smaller mapping efforts are added to GDB on an ongoing basis. The database can be searched by a variety of methods, ranging from keyword searches to complex queries. Major functionality extensions in the last year include the ongoing computation of integrated human genome maps, called Comprehensive Maps, and the use of those maps to support positional queries and graphic displays. The capabilities of the GDB map viewer (Mapview) have been extended to include map printing and the graphical display of ad hoc query results. The HUGO Nomenclature Committee continues to curate the proposed and official gene symbols and related data in collaboration with GDB. As genome research shifts its emphasis from mapping to sequencing and functional analysis, the scope of the GDB schema is being extended. We are in the process of adding representations of gene function and expression, and improving our representation of human polymorphism and mutation.

Animals↗
PubMed1994

Maternal immunity to measles and infant immunity at less than twelve months of age relative to maternal place of birth.

Sera from infants aged 5 to 11 months and from their mothers were used to investigate the level and duration of transplacentally derived measles antibody. The infants of foreign-born, inner-city mothers were more likely to have measles antibody and were less likely to get measles. Infants of foreign-born mothers, because they are less likely to respond to measles vaccine, may require different vaccine strategies than infants of mothers born in the United States.

Antibodies, Viral↗
PubMed1994

The effect of high salt intake on Na+, K(+)-ATPase activity of tissues in the rat.

1. The effect of chronic feeding of high salt diet on Na+, K(+)-ATPase activity of heart, liver, skeletal muscle, kidney and aorta was studied in the rat. 2. Groups of rats were either given tap water or 18 g/L saline to drink. After 7 days, 3 months or 12 months, the control group and salt loaded groups were sacrificed and Na+, K(+)-ATPase activity of heart, liver, skeletal muscle and kidney was determined by a coupled enzyme assay and that of the aorta by the K(+)-stimulated hydrolysis of 3-0-methylfluorescein phosphate. 3. Na+, K(+)-ATPase activity of heart, liver, skeletal muscle and aorta were not different between the experimental and control groups at 7 days. After 3 months, Na+, K(+)-ATPase activity of liver in salt-loaded group was higher than the control group. After 12 months of salt loading all tissues examined showed higher Na+, K(+)-ATPase activity compared to control groups. The activity of renal medulla of salt-loaded group was higher than that of control group as early as 7 days. 4. We conclude that long term salt loading causes an increase in the activity of Na+, K(+)-ATPase of kidney, heart, liver, muscle and aorta.

Animals↗
PubMed1994

Gallstone images on plain film and endoscopic retrograde cholangiopancreatography.

Different compositions of gallstone merit different treatments if a non-surgical method is chosen for these patients. In this study, gallstones collected from 125 patients were classified into cholesterol (pure, combination, mixed N = 28), brown (N = 64) and black (N = 41) stones by the Gallstone Classification of the Japanese Study Group (1986). Plain film and endoscopic retrograde cholangiopancreatography (ERCP) were reviewed in an attempt to predict the composition of the stones. We found that shape and location were highly correlated with stone composition. Most of the sandy stones were black stones (15/19, 79%); and 48% (10/21) of the irregular stones were brown stones; 70% (14) of facet stones were brown stones, 30% cholesterol stones. Stones in the gallbladder tended to be of the cholesterol type (47%, 13/28), 64% (51/81) of the bile duct stones were brown stones and 69% (11/16) of the gallbladder and bile duct stones were brown stones. We therefore conclude that imaging studies using plain film and ERCP is a fairly accurate means of predicting the composition of gallstone.

Bile Duct Diseases↗
PubMed1993

The chronic effects of long-term digoxin administration on Na+/K(+)-ATPase activity in rat tissues.

We have studied the effects of digoxin administration on Na+/K(+)-ATPase activity in heart, liver, muscle, renal medulla and aorta in the rat. Adult male rats were either treated with digoxin for 3 days, 7 days (5 mg/kg per day) or 3 months (3 mg/kg per day). Another group of rats were treated with the vehicle as controls. At the end of the experimental period, blood samples were taken for digoxin measurements, the animals were sacrificed, and the heart, liver, kidney, skeletal muscle and aorta were removed, homogenised and assayed for Na+/K(+)-ATPase activity. In all tissues except the aorta Na+/K(+)-ATPase activity was measured by an enzyme coupled reaction. Na+/K(+)-ATPase activity in the aorta was measured by a fluorometric potassium dependent 3-O-methyl fluorescein phosphatase activity. Plasma digoxin concentration in the digoxin group was 5.34 nmol/l (S.E.M., 0.09) in the 3-day group and 4.38 (0.68) and 4.89 (0.73) nmol/l in the 7-day and 3-month groups, respectively. After treatment for 3 days and 7 days, the Na+/K(+)-ATPase activity in all tissues was significantly lower in the digoxin group (the decrease in activity ranging from 13.4% in muscle to 46.9% in the renal medulla). After 3 months of treatment, Na+/K(+)-ATPase activity in all the tissues except the aorta was similar in the digoxin and control groups. In the aorta the activity remained low. We conclude that in rats digoxin administration causes upregulation of the Na+/K(+)-ATPase in most tissues.

Animals↗
PubMed1993

Maternal and congenital syphilis in Brooklyn, NY. Epidemiology, transmission, and diagnosis.

OBJECTIVE: To define the epidemiology, to determine factors associated with transmission, and to describe the clinical and laboratory features of congenital syphilis. DESIGN: Retrospective chart review and prospective analysis. SETTING: Kings County Hospital Center, Brooklyn, NY. PATIENTS: A total of 403 pregnancies during a 23-month period associated with positive syphilis serological findings. RESULTS: Seventy-three pregnancies (18%) resulted in congenital syphilis (35 live-born and 40 stillborn neonates). Pregnancies associated with congenital syphilis were significantly associated with lack of prenatal care, lack of maternal therapy for syphilis, and a higher rapid plasma reagin titer, but not with a reported history of "crack" or cocaine use, although detection of cocaine in urine samples was more likely with positive syphilis serology. CONCLUSION: Most live-born infants with congenital syphilis (23 of 35) lacked rash, hepatosplenomegaly, or adenopathy but were identified by laboratory tests (roentgenograms, cerebrospinal fluid VDRL test, conjugated bilirubin determination, or aspartate aminotransferase levels in serum samples). Half of the infants with congenital syphilis were stillborn.

Delivery, Obstetric↗
PubMed1992

AIDS awareness and risk behaviors among dually disordered adults.

An exploratory needs assessment was conducted among 50 clients of an abstinence-oriented outpatient clinic for adults experiencing coexisting drug abuse and chronic mental disorders. Findings revealed that, despite education and prevention efforts, sample members possessed considerable misinformation about AIDS and continued to engage in high risk heterosexual practices. Their knowledge level was not associated significantly with their admission diagnoses. Knowledge level also did not correlate significantly with safer sexual practices. These findings have implications for the development of AIDS education and prevention programs for dually disordered clients. To be effective, AIDS prevention and education efforts must be targeted at the clients' specific needs. Clear, explicit information about AIDS must be provided. In addition, behavioral-attitudinal change strategies that focus on the high-risk situations encountered by the clients and teach them alternative safer sex practices are required.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Condom knowledge, history of use, and attitudes among chemically addicted populations.

The need for behavioral change of risky sexual practices has been of the highest priority since the onset of the AIDS epidemic. The major focus of education for safe sex has been emphasis on condom use. We surveyed 124 individuals applying to treatment for various chemical dependencies and 60 individuals applying for non-chemical-dependency medical treatment on various aspects of condom knowledge, history of use, and attitudes. Respondents reported that AIDS has motivated them to increase their use of condoms, however, only 13.9% always use them. Education is needed in the areas of increasing protection. Along with the use of a condom, the need for a reservoir tip and the risks associated with multiple sex partners should be stressed.

Adult↗
PubMed1991

Contrasting work environments of medical school faculty.

An attitude survey has revealed vividly contrasting institutional atmosphere and working conditions at U.S. medical schools. Environments at about one-fourth of the schools were judged to be highly positive with regard to subjective atmosphere, career development, and faculty-administration relations. Environments at another one-fourth of all schools were judged to be highly negative in all of these areas. Recognizing the existence of these differences is necessary before administrative remedies for many of the problems at the latter group of schools can be implemented.

Attitude↗
PubMed1991

Disseminated tuberculosis in the acquired immunodeficiency syndrome era.

To assess the influence of human immunodeficiency virus type 1 (HIV)-induced immunodeficiency on the clinical, radiographic, and pathologic features of disseminated tuberculosis (TB), we studied 79 patients presenting in 1984 through 1987 with miliary or focal disseminated disease due to Mycobacterium tuberculosis, as well as 4 additional non-HIV patients diagnosed after 1987. Clinically defined acquired immunodeficiency syndrome (AIDS) or AIDS-related complex (ARC) was present in 51 (Group 1). A total of 20 had TB unrelated to HIV disease (Group 2). The remaining 12 were excluded because the role of HIV could not be determined. Clinical features were similar between groups aside from younger age; lower hemoglobin, total leukocyte, lymphocyte, and platelet counts; and more frequent tuberculin anergy (90 versus 40%) in AIDS/ARC patients (p less than or equal to 0.03). Chest radiographs showed a miliary pattern in about half of each group. Pleural effusion occurred only in AIDS/ARC patients (24%, p = 0.02), but intrathoracic lymphadenopathy was present in about a third of each group. Tissue biopsies (n = 70) usually revealed necrotizing granulomatous inflammation in each group, with a tendency to greater necrosis and more numerous acid-fast bacilli in Group 1. Granulomas were usually poorly formed in AIDS/ARC patients (59 versus 18%, p = 0.01). Autopsy of 9 AIDS/ARC patients with overwhelming miliary TB revealed a "nonreactive" histologic pattern with poorly organized or absent granulomas, extensive necrosis, and numerous bacilli. HIV-related disseminated TB causes a major constitutional illness with a high short-term mortality (25%).(ABSTRACT TRUNCATED AT 250 WORDS)

AIDS-Related Complex↗
PubMed1990

[Body temperature changes in cancer patients with yin or yang deficiency and blood stasis syndrome].

The body temperature change of cancer patients with Yin or Yang deficiency and blood stasis syndrome varied within normal limits in a day. The researchers divided 60 cases of cancer patients into Yin or Yang deficiency and blood stasis syndrome groups. Their body temperature was measured 6 times daily with radio thermometer. The results showed: at different time during one day, temperature change of patients in Yin deficiency group fluctuated obviously. The mean temperature of patients in blood stasis group was higher than other two groups. The daily highest temperature of patients in the above two groups appeared at 6:00 pm. Temperature change of patients in Yang deficiency group was stable relatively and the highest temperature appeared at 2:00 pm. The palm temperature of patients who feel dysphoria with feverish sensation in chest, palms and sole was not higher than armpit temperature. These observations should provide new objective bases for clinical measurement time of temperature and syndrome diagnosis.

Adult↗
PubMed1988

End products of glucose and glutamine metabolism by cultured cell lines.

Rates of CO2 production from glucose and glutamine, intracellular metabolite levels, and release of metabolic end products into the culture medium were determined for 13 cultured cell lines, including a glycolysis-defective mutant. All the non-mutant lines synthesized pyruvate, lactate, alanine, proline, aspartate, and citrate, so that the metabolism of glucose and glutamine resulted mainly in the production of these compounds and only to a lesser extent in complete oxidation to CO2. These data and the pattern of metabolites produced by the mutant line were consistent with a model characterized by incomplete glutamine oxidation leading to end product accumulation. Multiple linear regression analysis identified the metabolite levels most highly correlated with the intracellular citrate level and with the amount of citrate released into the medium. The analysis also showed that the rates of CO2 production from glucose and glutamine were themselves positively correlated, suggesting that the oxidation of the two substrates is coordinately controlled under normal culture conditions.

Animals↗