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Biomedical subjects

Y Yin

Publications and source records attributed to Y Yin.

At least 145 records · Page 8Linked to original sources
PubMed1994

Endemic fluorosis of the skeleton: radiographic features in 127 patients.

OBJECTIVE: A wide range of radiographic appearances have been reported in skeletal fluorosis, but little has been written about the spectrum of radiographic features. We evaluated the spectrum of radiographic appearances in this disorder to help with its diagnosis and differentiation from other metabolic skeletal disorders. MATERIALS AND METHODS: One hundred twenty-seven patients with clinically proved endemic fluorosis had radiographs of the chest, spine, pelvis, elbow, forearm, and knee obtained. The radiographic findings were classified as osteosclerosis, osteopenia, intermittent growth lines, diaphyseal widening, or soft-tissue ossification. Two different osteopenic patterns were defined: an osteoporotic pattern with overall decreased bone density and an osteomalacic pattern that combines the features of osteoporosis with bone deformity. Soft-tissue ossification included involvement of ligaments, tendons, and interosseous membranes. RESULTS: Ninety-eight of the patients (89% of the adults) had some evidence of calcification and/or ossification of the attachments of ligaments, tendons, muscles, and interosseous membranes. Osteosclerosis was seen in 54 patients (43%), and osteopenia was seen in 51 patients (40%). Of the patients with osteopenia, the osteoporotic pattern was seen in 28 and the osteomalacic pattern in 23. Growth lines were found in 89 patients (70%). Metaphyseal osteomalacic zones were found in children. Diaphyseal widening was present in 35 patients (28%). CONCLUSION: Endemic skeletal fluorosis can have a wide variety of radiographic appearances, including calcification and/or ossification of the attachments of soft-tissue structures to bone, osteosclerosis, osteopenia, growth lines, and metaphyseal osteomalacic zones.

Adolescent↗
PubMed1994

A 47-year-old woman with a 5-year history of bilateral hand deformities.

The following case is presented to illustrate the roentgenographic and clinical findings of a condition of interest to the orthopaedic surgeon. Initial history, physical findings, and roentgenographic examinations are offered for your consideration. The final clinical and roentgenographic differential diagnoses are presented on the following pages.

Calcinosis↗
PubMed1994

Autoamputation of the fingertips in an 11-year-old boy.

The following case is presented to illustrate the roentgenographic and clinical findings of a condition of interest to the orthopaedic surgeon. The final clinical and roentgenographic differential diagnoses can be found on the following pages.

Child↗
PubMed1994

A 30-year-old woman with 13-year history of pain in multiple joints.

The following case is presented to illustrate the roentgenographic and clinical findings of a condition of interest to the orthopaedic surgeon. Initial history, physical findings, and roentgenographic examinations are found on the first two pages. The final clinical and roentgenographic differential diagnoses are presented on the following pages.

Adult↗
PubMed1994

An 11-year-old boy with swelling and progressive deformity of his finger.

The following case is presented to illustrate the roentgenographic and clinical findings of a condition of interest to the orthopaedic surgeon. Initial history, physical findings, and roentgenographic examinations are found on the first two pages. The final clinical and roentgenographic differential diagnoses are presented on the following pages.

Age of Onset↗
PubMed1994

A 73-year-old woman with stiffness in both hands.

The following case is presented to illustrate the roentgenographic and clinical findings of a condition of interest to the orthopaedic surgeon. Initial history, physical findings, and roentgenographic examinations are found on the first page. The final clinical and roentgenographic differential diagnoses are presented on the following pages.

Aged↗
PubMed1993

Conformational changes at the active site of creatine kinase at low concentrations of guanidinium chloride.

It has been previously reported that, during denaturation of creatine kinase by guanidinium chloride (GdmCl) or urea [Tsou (1986), Trends Biochem. Sci. 11, 427-429], inactivation occurs before noticeable conformational change can be detected, and it is suggested that the conformation at the active site is more easily perturbed and hence more flexible than the molecule as a whole. In this study, the thiol and amino groups at or near the active site of creatine kinase are labelled with o-phthalaldehyde to form a fluorescent probe. Both the emission intensity and anisotropy decrease during denaturation indicating exposure of this probe and increased mobility of the active site. The above conformational changes take place together with enzyme inactivation at lower GdmCl concentrations than required to bring about intrinsic fluorescence changes of the enzyme. At the same GdmCl concentration, the rate of exposure of the probe is comparable with that of inactivation and is several orders of magnitude faster than that for the unfolding of the molecule as a whole.

Animals↗
PubMed1993

Cloning and sequencing of a cDNA coding for bovine conglutinin.

A 912 bp bovine cDNA fragment encoding bovine conglutinin was amplified by the RT-PCR technique. cDNA clones encoding the bovine conglutinin were isolated from a bovine liver cDNA library using a specific probe obtained from the PCR product. These cDNAs carry an insert of 1113 bp coding for a protein of 371 amino acid residues with a signal peptide of 20 residues. The deduced amino acid sequence of cDNA agrees with that determined by conventional amino acid sequence analysis. Two polyadenylation signal sequences were detected in the DNA sequence downstream of the 3' end of the gene. Southern blot analysis of total bovine genomic DNA indicated that there is only one copy of the gene encoding bovine conglutinin. Northern blot analysis of bovine tissues showed that conglutinin mRNA of about 1.5 kb is expressed in the liver and also slightly in the lung.

Amino Acid Sequence↗
PubMed1993

Diet, aberrant crypt foci and colorectal cancer.

We have used the aberrant crypt focus (ACF) assay to test and develop hypotheses linking diet and colon cancer. The hypotheses were suggested by epidemiological studies that identified possible dietary factors associated with colorectal cancer risk. The ACF assay was used to quantitate the effect of the dietary factors on the initiation and growth of these putative precursors of colon cancers in experimental animals. Using this approach we have developed 3 new hypotheses for the role of diet in colorectal cancer. These are (1) a risk associated with 5-hydroxymethyl-2-furaldehyde in caramelized sugar, (2) a risk associated with some factor in thermolyzed casein, and (3) a risk associated with single nutrient boluses of sucrose and fructose. The importance of these hypotheses has still to be tested in long term carcinogenesis experiments, in analytic epidemiology studies and then, perhaps, in intervention trials.

Animals↗
PubMed1993

DNA repair in congenic mice: possible influence of a chromosome 4 genetic region on the rate of benzo[a]pyrene-induced DNA adduct removal.

An attempt was made to assign mouse lifespan-associated interstrain differences in DNA repair to a specific chromosomal region using a set of congenic mice. The sensitive 32P-postlabeling assay was employed to measure the removal of benzo[a]pyrene-induced DNA adducts in liver DNA of three different chromosome 4 congenic mouse strains: B6.C-H-15c, B6.C-H-16c, and B6.C-H-26c and the two parental strains, C57B1/6 and BALB/c. The removal of the one main adduct detected, trans-(7R)-N2-[10-(7 beta,8 alpha,9 alpha-trihydroxy)-7,8,9,10- tetrahydrobenzo(a)-pyrene]-yl-deoxyguanosine (BPDE-N2-dG), in liver DNA of C57Bl/6 and BALB/c mice between one and three days after treatment, was approximately 86% and 57%, respectively. The percentage removal of BPDE-N2-dG in two of the three congenic mouse strains, B6.C-H-16c and B6.C-H-26c, resembled that found in BALB/c, whereas the third strain, B6.C-H-15c, removed about the same amount as C57B1/6, i.e., approximately 88% of BPDE-N2-dG between one and three days after treatment. The usefulness of congenic mouse strains for identifying genes putatively involved in aging and/or disease susceptibility is discussed.

7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide↗
PubMed1993

Developmental and cAMP-mediated regulation of glycogen phosphorylase 1 in Dictyostelium discoideum.

The Dictyostelium discoideum glycogen phosphorylase-1 (gp-1) exhibits a complex pattern of developmental expression in which differential temporal regulation of enzyme activity, protein levels and mRNA levels is observed. This pattern of expression implies that gp-1 regulation occurs at multiple levels, probably involving both transcriptional and post-transcriptional events. Post-translational control of gp-1 activity, in effect, actually regulates the protein from a developmental perspective. In this report we have examined several facets of this regulation. We show that addition of exogenous cAMP to cells in suspension culture caused changes in gp-1 enzyme activity and mRNA levels that are identical to those observed during normal development, suggesting that cAMP is involved in the regulation of gp-1. Exogenous cAMP could regulate gp-1 mRNA expression at concentrations as low as 1.0 microM. cAMP regulation of gp-1 mRNA appeared to occur through a mechanism that required intracellular cAMP signalling. We identified regions of the promoter necessary for gp-1 expression by using gp-1 promoter deletions to drive the expression of a luciferase reporter gene. Results of these experiments suggested that developmental and cAMP-mediated changes in gp-1 mRNA levels were the result of alterations in transcription. The promoter analysis also suggested that a vegetative specific element is located between -785 and -1894 nucleotides from the transcriptional start site. Elements necessary for maximal developmental and cAMP-mediated expression appear to be located between -1153 and -1894 nucleotides from the cap site. Sequence elements located between -180 and -1153 appear to be required for a basal level of late developmental expression.

Animals↗
PubMed1993

Identification of a carbohydrate recognition domain in filamentous hemagglutinin from Bordetella pertussis.

The adherence of Bordetella pertussis to ciliated cells and macrophages is critical to colonization and infection of the respiratory tract. Adherence to both types of cells involves the recognition of eukaryotic carbohydrates by the bacterial adhesin filamentous hemagglutinin (Fha). The carbohydrate recognition domain (CRD) of Fha is considered an important antigen for subcomponent vaccines to maximize the generation of antiadherence antibodies capable of protecting against colonization. For identification of the CRD of Fha, a bank of eight monoclonal antibodies (MAbs) that mapped to four contiguous regions were tested for their ability to block Fha binding to lactosylceramide or to block bacterial binding to ciliated cells. Only MAb 12.5A9, which maps to amino acid residues 1141 to 1279, blocked both Fha binding to lactosylceramide and bacterial binding to ciliated cells. An 18-kDa polypeptide corresponding to this region was expressed in Escherichia coli. Cell lysates containing this protein bound to lactosylceramide in a manner identical to that of native Fha. Mutant strains of B. pertussis that contained an in-frame deletion of the coding sequence for this region produced a truncated Fha that showed negligible cross-reactivity with MAb 12.5A9. In an adherence assay, these mutant strains failed to bind efficiently to either ciliated cells or macrophages. The numbers of adherent bacteria for these strains were reduced to the number obtained with a nonadherent strain. We conclude that the region defined by residues 1141 to 1279 of Fha constitutes a CRD critical for bacterial adherence and represents a potential candidate for a subcomponent vaccine.

Adhesins, Bacterial↗
PubMed1993

A 21-year-old man with pain and swelling of the right hand.

The following case is presented to illustrate the roentgenographic and clinical findings of a condition of interest to the orthopaedic surgeon. Initial history, physical findings, and roentgenographic examinations are found on this page. The final clinical and roentgenographic differential diagnoses are presented on the following pages.

Adult↗
PubMed1993

A 43-year-old woman with right hip pain.

Although tuberculous arthritis is currently uncommon in the United States, the hip joint is a common location. Tuberculous arthritis usually presents as a mild, slowly progressing process. It often involves a single joint. Radiological findings include osteopenia of the involved joint, soft tissue swelling, bone destruction without evidence of bone formation, and sequestrum formation. Several conditions should be considered in the differential diagnosis. The detailed roentgenographic appearances and many of the differential diagnoses are included in this paper. Final diagnosis is made by positive culture results or finding the bacillus histologically.

Adult↗
PubMed1993

A 77-year-old man with a gradually enlarging mass of the left ring finger.

The following case is presented to illustrate the roentgenographic and clinical findings of a condition of interest to the orthopaedic surgeon. Initial history, physical findings, and roentgenographic examinations are found on the first page. The final clinical and roentgenographic differential diagnoses are presented on the following pages.

Aged↗