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Biomedical subjects

Y Pan

Publications and source records attributed to Y Pan.

At least 163 records · Page 9Linked to original sources

Bilateral reduction mammoplasty in a patient treated with calcium channel blocker and cyclosporine after renal transplant: a case report.

A 28-year-old woman with end-stage renal disease secondary to diabetes mellitus and hypertension underwent cadaver renal transplant in April 1992. After surgery, she developed bilateral breast enlargement while she was taking cyclosporine for immunosuppression therapy and felodipine, a calcium channel blocker, for blood pressure control. She underwent bilateral reduction mammoplasty in June 1995 to treat progressive breast enlargement which interfered with her normal life activities. Through mechanisms only partially understood, calcium channel blockers and cyclosporine are reported to increase the serum prolactin level, producing gynecomastia in men. There is no report in current literature to support a similar phenomenon in women.

Adult↗

Measurement of fetal nasal width by ultrasonography.

OBJECTIVE: This study was designed to determine the range of normal fetal nasal width by ultrasonography, which may be beneficial for detection of trisomy 21 and other chromosomal abnormalities. We hypothesize that a wide, saddle-shaped nose, which is one of the clinical neonatal anatomic features of trisomy 21, can be diagnosed prenatally. STUDY DESIGN: Fetal nasal width diameter was measured on 782 normal white fetuses by ultrasonography. Gestational ages ranged from 13.8 to 40.4 weeks. Mean and SD of fetal width diameter was calculated weekly by gestational age to establish normal values. RESULTS: The fetal nasal width increased as a function of gestational age, showing a polynomial curve during pregnancy (r = 0.912, p = 0.002). With use of mean +/- 1 SD as a cutoff value, the results showed a sensitivity of 80% with a specificity of 67% and a positive predictive value of 2.2% with a negative predictive value of 99.7% for the diagnosis of trisomy 21. CONCLUSION: The fetal nasal width diameter may be used as a biometric measurement and may be useful to identify trisomy 21 or other chromosomal abnormalities in conjunction with other already defined parameters used in a genetic ultrasonographic screen.

Amniocentesis↗

Early neuroradiologic evidence of degeneration in Menkes' disease.

We report the case of an infant with Menkes' disease who presented with moderately abnormal neurologic findings at birth and with extraaxial bleeding in the posterior fossa. Early cerebellar atrophy and hypomyelination were evident on magnetic resonance imaging at 5 weeks of age. We suggest that neurodegeneration occurs earlier than has been previously reported and may be identifiable even in neonates.

Cerebral Hemorrhage↗

mRNA expression and cDNA sequences of beta- and gamma-sarcoglycans are normal in cardiomyopathic hamster heart.

In BIO14.6 cardiomyopathic hamster heart, the dystrophin-glycoprotein complex is disrupted and sarcoglycans are greatly reduced in abundance. We examined whether the gene expression of beta- and gamma-sarcoglycans is indeed defective in this hamster. We found that mRNA expression for these proteins and the cDNA sequences of their coding regions are identical in both normal and myopathic hamster cardiomyocytes. The results strongly suggest that defect in a currently unknown sarcoglycan-associated protein(s) is responsible for the deficiency of the sarcoglycan complex that leads to muscle cell necrosis in the myopathic hamster.

Amino Acid Sequence↗

Effect of tripterine on collagen-induced arthritis in rats.

AIM: To study the therapeutic effect of tripterine (Tri) on collagen-induced arthritis (CIA). METHODS: Collagen type II (Col) 1.5 mg was injected intradermally to induce CIA in rats. Hind paw volumes of rats were measured with a water displacement method. The serum anti-collagen antibody was measured by an enzyme-linked immunosorbent assay. Delayed hypersensitivity was reflected by skin response to Col. Interleukin-1 (IL-1) and interleukin-2 (IL-2) activities were evaluated by [3H]TdR uptake. Joint was evaluated histologically. RESULTS: Tri 15 and 30 mg.kg-1.d-1 given i.g. to rats 3 d after the first sign of arthritis reduced inflammatory swelling, suppressed humoral and skin response to Col, inhibited IL-2 and IL-1 production, reduced pathological progression of joint. CONCLUSION: Tri has a therapeutic effect on CIA.

Animals↗

[Determination of mangiferin in qingqiliangying injection by reversed-phase HPLC].

A reversed-phase HPLC method has been established for the determination of mangiferin in Qingqiliangying Injection. The mangiferin was separated on a Nova-pak C18 column (150 mm x 3.9 mm) and detected at 258 nm, using methanol-tetrahydrofuran-0.85% H3PO4 aqueous solution (500:80:15) as the mobile phase. The average recovery of mangiferin was 100.9%. The method is simple, rapid, and well reproducible, and thus very reliable for the quality control of Qingqiliangying Injection.

Chromatography, High Pressure Liquid↗

[Tetraploid clones characterized by double 8;21 translocations in two patients with acute myeloid leukemia].

OBJECTIVE: To report two cases of leukemia with t(8;21) and tetraploid clones. METHODS: R-banding technique was used. RESULTS: Cytogenetic studies of BM cells at diagnosis revealed that each of the two cases had three related abnormal clones besides a normal one: 46, XY, t(8;21) (2%), 46, idem, add((7)(q31)(6.8%) and 92, idem x 2 (80.6%) in case 1 and 46, XX, t(8;21) (13.4%), 47, idem, + 4 (46.3%) and 94, idem x 2 (39.1%) in case 2. They did not obtain complete remission on chemotherapy and survived 4 and 6 months, respectively. CONCLUSION: Tetraploid or near tetraploid clones are secondary events which are specifically associated with t(8;21) leukemia and the prognosis of patients with this kind of abnormal karyotype is poor.

Adult↗

Fetal atrial septal aneurysm. Prenatal diagnosis by ultrasonography.

OBJECTIVE: To assess prenatal diagnosis by ultrasonography in five cases of fetal atrial septal aneurysm. STUDY DESIGN: Five cases of fetal atrial septal aneurysm were diagnosed prenatally by ultrasound. Postpartum fetal cardiac echocardiography was performed in three of five infants from the first to the fourth day of life. The medical records of the five cases were reviewed and analyzed after delivery. RESULTS: Echocardiograms confirmed atrial septal aneurysm in two of the three neonates. One of the two infants was also found to have a patent foramen ovale, and the other infant had patent duct arteriosis in addition to a patent foramen ovale. Two had fetal cardiac arrythmias that resolved after birth. CONCLUSION: Atrial septal aneurysm in fetuses may be a natural transition in spontaneous closure of the associated patent foramen ovale or septal defect. The same phenomenon has been found in children and infants. Due to the uniqueness of the fetal circulation, atrial septal aneurysm may predispose to fetal arrythmias.

Adolescent↗

Expression of a dystrophin-sarcoglycan complex in serum-deprived BC3H1 cells and involvement of alpha-sarcoglycan in substrate attachment.

Dystrophin and alpha- and gamma-sarcoglycans were newly expressed in BC3H1 cells during differentiation induced by serum withdrawal. These proteins formed a tight complex with other dystophin-associated proteins (DAPs), as detected by immunoprecipitation with anti-dystrophin antibody. Integrins beta 1 and beta 3, vinculin, and focal adhesion kinase were also detected in the same immunoprecipitate. In a cell adhesion assay, differentiated BC3H1 cells attached more efficiently to type I collagen-coated dishes than nondifferentiated cells and loss of alpha-sarcoglycan induced by antisense ODN in differentiated cells resulted in significant inhibition of cell adhesion. Thus dystrophin and DAPs, at least partly, form a complex with the focal adhesion proteins in differentiated BC3H1 cells and alpha-sarcoglycan seems to modulate the function of the focal adhesion complex in these cells.

Animals↗

Expression of ceruloplasmin gene in human and rat lymphocytes.

The acute phase plasma protein ceruloplasmin (Cp) appears to play some role in host defense. The possibility that production of Cp in extrahepatic sites may also be essential for the activation, effector functions and cytoprotection of immune cells in localized environments has received minimal attention. Here, we have surveyed various types of human and rat immune cells for the presence of Cp mRNA using RT-PCR with primers that span exons 17-19 as an initial step in addressing this possibility. Validated Cp RT-PCR bands were obtained from RNA samples isolated from resting and activated human lymphocytes, CD4 and CD8 T-cells and B-cells. Semiquantitative RT-PCR indicated that Cp mRNA in immune cells is present at about 0.2% the level of Cp mRNA in HepG-2 human liver cell line. Various human cell lines derived from the immune system, rat splenic MNC and purified rat T-lymphocytes also constitutively express Cp gene.

Animals↗

Phosphorylation-dependent regulation of cardiac Na+/Ca2+ exchanger via protein kinase C.

The cardiac Na+/Ca2+ exchanger (NCX1) plays a major role in the extrusion of Ca2+ from cardiomyocytes. We studied the role of protein phosphorylation in the regulation of cardiac NCX1 using CCL39 stably overexpressing the canine cardiac NCX1 and rat neonatal cardiomyocytes. In both cell types, the NCX1 protein immunoprecipitated with a chicken anti-NCX1 antibody exhibited a significant basal phosphorylation that was further enhanced by treatment with endothelin-1, acidic fibroblast growth factor, phorbol 12-myristate 13-acetate, or okadaic acid. In contrast, calphostin C, K252a, or EGTA inhibited the phosphorylation. The phosphorylation occurred on two major tryptic phosphopeptides (P1 and P2) exclusively on serine residues. Evidence is presented suggesting that P2 was derived from an N-terminal half (amino acids 240-475) of the central cytoplasmic domain of NCX1 and was phosphorylated directly by protein kinase C (PKC). The agents that increased NCX1 phosphorylation significantly enhanced both the forward and reverse modes of Na+/Ca2+ exchange. This exchange activation exhibited a very good correlation with the NCX1 phosphorylation. In NCX1-transfected cells, PKC down-regulation following prolonged exposure to phorbol 12-myristate 13-acetate abolished the acidic fibroblast growth factor-induced activation of exchange activity. On the other hand, cell ATP depletion reduced the exchange activity and abolished the effects of the above agents on exchange activity. These results indicate that the cardiac NCX1 is up-regulated by PKC-catalyzed phosphorylation. The cardiac NCX1 thus could play an important role in the previously reported negative inotropic actions of phorbol esters and other PKC-activating agents.

Adenosine Triphosphate↗

S-phase fraction of 155 soft tissue sarcomas: correlation with clinical outcome.

BACKGROUND: Traditionally, grade is considered the most important prognostic factor for soft tissue sarcomas (STS). However, because of the alleged difficulties in reproducibility of grading, new, objectively determined prognostic factors would be of value. The aim of our study was to establish if S-phase fraction (SPF) measured with flow cytometry was of prognostic significance for STS. METHODS: In this study, we included all 193 adult STS patients with superficial trunk or limb tumors who were treated by the Helsinki University Central Hospital (HUCH) STS group between January 1987 and May 1993. One hundred and seventy-two formalin fixed paraffin embedded tumor samples were available. SPF measurement was successful in 155 cases. RESULTS: Eighty-six cases were diploid. Ploidy was found to have no effect on overall survival. The median SPF was 6.8% (diploid tumors, 4% and nondiploid tumors, 12.9%). A high SPF predicted a shorter survival in patients with diploid tumors (P=0.003). The prognostic value was even stronger when we studied disease specific survival and excluded from analysis samples that contained less than 50% tumor cells (P=0.011). However, no prognostic value could be detected in nondiploid tumors or in the material as a whole. CONCLUSIONS: Our results suggest that high SPF is an adverse prognostic factor for survival of patients with diploid STS. However, further studies are needed to confirm these results.

Adolescent↗

An oligodeoxyribonucleotide N3'--> P5' phosphoramidate duplex forms an A-type helix in solution.

The solution conformations of the dinucleotide d(TT) and the modified duplex d(CGCGAATTCGCG)2 with N3'--> P5' phosphoramidate internucleoside linkages have been studied using circular dichroism (CD) and NMR spectroscopy. The CD spectra indicate that the duplex conformation is similar to that of isosequential phosphodiester RNA, a A-type helix, and is different from that of DNA, a B-type helix, NMR studies of model dimers d(TpT) and N3'--> P5' phosphoramidate d(TnpT) show that the sugar ring conformation changes from predominantly C2'-endo to C3'-endo when the 3'-phosphoester is replaced by a phosphoramidate group. Two-dimensional NMR (NOESY, DQF-COSY and TOCSY spectra) studies of the duplex provide additional details about the A-type duplex conformation of the oligonucleotide phosphoramidate and confirm that all furanose rings of 3'-aminonucleotides adopt predominantly N-type sugar puckering.

Base Sequence↗

Dystrophin-glycoprotein complex purified from hamster cardiac muscle. Comparison of the complexes from cardiac and skeletal muscles of hamster and rabbit.

The dystrophin-glycoprotein complex was isolated from hamster ventricular muscle by a method involving homogenization of muscle directly in the presence of 1% digitonin, followed by chromatography on succinylated wheat germ agglutinin agarose, Diethyl aminoethyl (DEAE) cellulose, and/or immunoaffinity agarose. Protein yield of the DEAE cellulose-purified dystrophin-glycoprotein complex was 120 +/- 30 (n = 3) micrograms per 5 g hamster ventricular muscle. The cardiac dystrophin-glycoprotein complex, unlike the skeletal muscle counterpart, could not be solubilized from a microsomal fraction with digitonin or some other detergents. By sodium dodecyl sulfate gel electrophoresis, protein composition of the dystrophin-glycoprotein complexes from hamster cardiac muscle was found to be significantly different from that of rabbit skeletal muscle which has been extensively studied. This difference mainly arises from the species difference, because in hamster the cardiac and skeletal muscle complexes exhibited essentially the same protein composition. In rabbit, on the other hand, there are differences between the cardiac and skeletal complexes in the relative abundance of 60 and 64 kDa proteins and in the apparent M(r) of alpha-dystroglycan. We found that the content of the dystrophin-glycoprotein complex, estimated by quantitative immunoblot assay, is at least 5 times more abundant in cardiac than in skeletal muscle in hamster and rabbit.

Animals↗