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Biomedical subjects

C Y Yu

Publications and source records attributed to C Y Yu.

At least 55 records · Page 3Linked to original sources
PubMed1995

Renal tubular acidosis complicated with hypokalemic periodic paralysis.

Three Chinese girls with hypokalemic periodic paralysis secondary to different types of renal tubular acidosis are presented. One girl has primary distal renal tubular acidosis complicated with nephrocalcinosis. Another has primary Sjögren syndrome with distal renal tubular acidosis, which occurs rarely with hypokalemic periodic paralysis in children. The third has an isolated proximal renal tubular acidosis complicated with multiple organ abnormalities, unilateral carotid artery stenosis, respiratory failure, and consciousness disturbance. The diagnostic evaluation and emergent and prophylactic treatment for these three types of renal tubular acidosis are discussed.

Acidosis, Renal Tubular↗
PubMed1995

Diagnosis of disseminated candidiasis by fine needle aspiration of lymph node and by splenic imprint in a patient with acute promyelocytic leukemia.

Cytologic studies were done on fine needle aspirates of the lymph node and imprints of splenic biopsies from a patient with acute promyelocytic leukemia who was febrile while being treated with chemotherapy. Examination of the lymph node aspirates revealed pus and numerous pseudohyphae which were later identified as Candida tropicalis. When multiple nodular lesions were detected in the spleen by abdominal sonography and CT scan, needle biopsy of the spleen was done. Cytologic examination of touch imprints of the biopsy disclosed intracellular fungal blastospores. The patient was treated with and responded well to amphotericin B and 5-fluorocytosine. As a result of our experience with this patient we emphasize the importance of close incorporation of clinical information and diagnostic cytology. With such a cooperation, cytologic studies become a most useful method for diagnosis.

Adult↗
PubMed1995

Fat in the prediction of bone strength of porcine lumbar vertebrate by quantitative computed tomography.

The influence of fat content on quantitative computed tomography (QCT) values was studied using porcine lumbar vertebrae as a model. A total of 72 cancellous bone columns, prepared from 18 vertebrae, underwent QCT examination before and after defatting. Mechanical testing and ashing were performed to obtain the ultimate strength and bone mineral content. The ultimate strength was calculated as a power function of apparent density using linear regression on a log-log plot and the power coefficient was 1.88. QCT values were positively correlated with bone density. QCT values of defatted specimens correlated much better with ultimate strength than those of fresh specimens. The average fat content was 27.2%. The QCT values decreased linearly with increasing fat content with a slope of 7.9 mg/cm3/% fat and a correlation coefficient of 0.65. The results provided basic data for the calibration of the machine and the principles for the interpretation of QCT values excluding the fat influence.

Animals↗
PubMed1995

Magnetic resonance spectroscopic findings in patients with subcortical ischemic stroke.

BACKGROUND: Biochemical changes inside the brain during acute ictus have been extensively studied by means of magnetic resonance spectroscopy (MRS). Previous reports revealed that cerebral cortical infarction causes reduction of N-acetylaspartate (NAA) and elevation of lactate. This study was designed to evaluate the biochemical changes in subcortical infarction. METHODS: Nine normal controls and four patients, including two thalamic infarct, one basal ganglia infarct, and one putamen infarct cases were examined using MRS in addition to magnetic resonance imaging (MRI). Evaluation experiments were performed on a Siemens Wagnetom 63SP machine. A spin echo sequence with TE 270 msec was applied for the measurement. The voxel was located at basal ganglia in the controls and at the lesion site, as well as at the contralateral corresponding region in the patients. RESULTS: Three resonance signals were present in the spectrum-NAA, choline-containing compounds (Cho) and creatine-phosphocreatine (Cr). The NAA/Cho and NAA/Cr ratios were reduced significantly on the lesion side compared with the controls. NAA/Cho also decreased on the lesion side compared with the healthy side. CONCLUSIONS: There is a remarkable reduction of NAA concentration even in subcortical infarction. Further study is needed for the detection of changes in lactate in patients with subcortical lesion.

Adult↗
PubMed1995

Ultrasonographic evaluation of multicystic dysplastic kidney.

Eleven cases of multicystic dysplastic kidney (MCDK) in children were diagnosed over an 11 year period. All underwent postnatal ultrasound (US) studies. Four different patterns of MCDK were recognized: (1) Six cases presented with the classic sonogram of multicystic components. (2) Three cases had hydronephrotic form; correct diagnosis between hydronephrotic form of MCDK and hydronephrosis was difficult as there was a medially-located, large, lobulated cyst and there was connection between the large cyst and neighboring small cysts. (3) One case initially presented with normal renal sonogram but a small cyst appeared on follow up sonogram and there was also decreased renal size and increased echogenecity. (4) One case had only two moderate-sized cysts but no identifiable renal parenchyma. Two cases had follow-up US examination and one dysplastic kidney decreased in renal size on follow-up sonogram. Intravenous urography and radionuclide study revealed both these dysplastic kidneys to be nonfunctioning. Nine children had surgical resection of the diseased kidneys. Contralateral renal anomalies were detected in five children, which included ureteropelvic junction stenosis, ureterovesical junction stenosis, distal ureteral stenosis and polycystic kidney disease. Two of three hydronephrotic forms of MCDK had contralateral ureteral stenosis. Two of six classic forms of MCDK had contralateral ureteral stenosis. The proportion of contralateral ureteral stenosis was higher in the group of hydronephrotic forms of MCDK. Ultrasonography is beneficial for conclusive diagnosis of MCDK; however, a differential diagnosis of simple hydronephrosis needs to be considered.

Female↗
PubMed1994

Flexion-extension rhythm in the lumbosacral spine.

STUDY DESIGN AND OBJECTIVES: This study was conducted to depict the qualitative and quantitative changes of intervertebral rotation and translation from L1-L2 to L5-S1 during flexion, standing, and extension using dynamic lumbosacral radiographs. METHODS: A radiopaque ruler was placed on the back of each subject for the normalization of translational value. Eighty-nine volunteers were examined. RESULTS: From extension to flexion, all of the intervertebral rotations approached 0 degree from the lordotic position; the translations changed from slightly retro-listhetic to zero displacement. Using L3-L4 as a baseline for calculating the intervertebral differences in flexion, all of the rotational differences were less than 1.5 degrees, except at L5-S1, which remained 5 degrees. The mean translational difference was less than 0.6 mm, except at L5-S1, where it remained 1.5 mm. CONCLUSIONS: The amount of total flexibility was level-dependent and its frequency distribution is important. Qualitative rhythmic changes from extension to flexion and quantitative values of intervertebral difference in flexion help define the normal flexibility more accurately.

Biomechanical Phenomena↗
PubMed1994

Structure and genetics of the partially duplicated gene RP located immediately upstream of the complement C4A and the C4B genes in the HLA class III region. Molecular cloning, exon-intron structure, composite retroposon, and breakpoint of gene duplication.

The correlation of many HLA-associated autoimmune and genetic diseases with the polymorphic complement C4 genes may be attributed to the presence of disease susceptibility genes in the close proximity of C4. We have cloned and characterized a pair of partially duplicated genes, RP1 and RP2, located 611 base pairs upstream of the human C4A and C4B genes, respectively. The putative RP protein, consisting of 364 amino acid residues, is basic and highly hydrophilic. There is a bipartite nuclear localization signal at residues 114-131 and therefore RP may be a nuclear protein. Northern blot analysis suggested that RP is ubiquitously expressed. The 5' region of the RP1 gene is CpG rich, which is a characteristic of housekeeping genes. The RP1 gene contains nine exons. Located in the fourth intron is a cluster of Alu elements, and a newly defined composite retroposon SVA with a SINE, multiple copies of GC-rich VNTRs and an Alu element altogether enclosed by direct terminal repeats. Members of SVA are also present in the complement C2 gene located about 20 kilobases upstream of RP1 in the HLA and in the cytochrome CYP1A1 gene. Determination of the DNA sequences for RP2 from two different HLA haplotypes revealed identical hybrid sequences which resulted from fusion of RP with the tenascin-like Gene X and truncation of the 5' regions of both genes. Cumulative data suggest that the four tandemly arranged genes RP, complement C4, steroid 21-hydroxylase (CYP21), and Gene X altogether form a modular structure, RCCX. The number of RCCX modules varies from one to three or more in the population. Absence of the truncated genes RP2 and Gene XA have been detected in genomes with single RCCX modules. Duplication of the RCCX modules probably occurred before the speciation of great apes and humans as they contain the same breakpoint region of RP and Gene X gene duplication.

Alleles↗
PubMed1994

The dichotomous size variation of human complement C4 genes is mediated by a novel family of endogenous retroviruses, which also establishes species-specific genomic patterns among Old World primates.

The human complement C4 genes in the HLA exhibit an unusual, dichotomous size polymorphism and a four-gene, modular variation involving novel gene RP, complement C4, steroid 21-hydroxylase (CYP21), and tenascin-like Gene X (RCCX). The C4 gene size dichotomy is mediated by an endogenous retrovirus, HERV-K(C4). Nearly identical sequences for this retrotransposon are present precisely at the same location in the long C4 genes from the tandem RCCX Module I and Module II. Specific nucleotide substitutions between the long and short C4 genes have been identified and used for diagnosis. Southern blot analyses revealed that HERV-K(C4) is present at more than 30 locations in the human genome, exhibits variations in the population, and its analogs exist in the genomes of Old World primates with species-specific patterns. Evidence of intrachromosomal recombination between the two long terminal repeats of HERV-K(C4) is found near the huntingtin locus on chromosome 4. It is possible that members of HERV-K(C4) are involved in genetic instabilities including the RCCX modules, and in protecting the host genome from retroviral attack through an antisense strategy.

Amino Acid Sequence↗
PubMed1994

Bilateral spontaneous pneumothoraces, pneumopericardium, pneumomediastinum, and subcutaneous emphysema: a rare presentation of paraquat intoxication.

Pneumothorax, subcutaneous emphysema, and pneumomediastinum occur frequently in critically ill patients in association with blunt or penetrating injuries or other conditions while performing Valsalva-like maneuvers. We present the case of a patient with bilateral pneumothoraces, pneumomediastinum, pneumopericardium, and subcutaneous emphysema after acute paraquat intoxication.

Acute Disease↗
PubMed1994

Detection of keratinocyte growth factor (KGF) transcripts from normal human and archival canine benign prostatic hyperplastic tissues.

This study examined the expression of keratinocyte growth factor (KGF) gene in human and canine prostatic tissues. KGF transcript was detected in normal human prostatic tissues by reverse transcription and polymerase chain reactions (RT-PCR). PCR-generated human KGF complementary DNA (cDNA) clone was confirmed by restriction enzyme digestion analysis and partial DNA sequencing. Expression of KGF in archival canine benign prostatic hyperplastic tissues was also examined. In a pilot experiment, RNAs isolated from formalin-fixed (FF) and formalin-fixed and paraffin-embedded (FFPE) canine prostatic tissues were shown to be of sufficient quality to permit amplification of KGF mRNA by RT-PCR. The transcript of a housekeeping gene, glucose-6-phosphate dehydrogenase (G6PD), was detected by RT-PCR indicating the quality of RNAs to be more than adequate for RNA expression analysis. Later, total RNA from two archival canine FF prostate tissue types, benign prostatic hyperplasis and mild glandular hyperplasia, were used to amplify canine KGF transcripts. Southern hybridization analysis using rat and human KGF cDNAs as probes confirmed the fidelity of the amplified PCR product and it was indeed canine KGF.

Animals↗
PubMed1994

Successful resection of a minute icteric hepatocellular carcinoma--case report.

A 38-year-old male was admitted to our department with jaundice. Imaging studies including ultrasonography, ERCP, PTC and computed tomography (CT) revealed a hilar lesion. Right hepatic lobectomy, caudate lobectomy, excision of CBD and restoration of biloenteric continuity was performed. Pathological examination showed an icteric hepatoma (1.2 x 0.8 x 0.8 cm in size) originating in the caudate lobe. The tumor thrombus occupied the common hepatic duct and the right intrahepatic duct. The postoperative course was fairly unremarkable, and the patient has remained in good health for four years after surgery without any sign of recurrence.

Adult↗
PubMed1993

Transcriptional activation of human zeta 2 globin promoter by the alpha globin regulatory element (HS-40): functional role of specific nuclear factor-DNA complexes.

We studied the functional interaction between human embryonic zeta 2 globin promoter and the alpha globin regulatory element (HS-40) located 40 kb upstream of the zeta 2 globin gene. It was shown by transient expression assay that HS-40 behaved as an authentic enhancer for high-level zeta 2 globin promoter activity in K562 cells, an erythroid cell line of embryonic and/or fetal origin. Although sequences located between -559 and -88 of the zeta 2 globin gene were dispensable for its expression on enhancerless plasmids, they were required for the HS-40 enhancer-mediated activity of the zeta 2 globin promoter. Site-directed mutagenesis demonstrated that this HS-40 enhancer-zeta 2 globin promoter interaction is mediated by the two GATA-1 factor binding motifs located at -230 and -104, respectively. The functional domains of HS-40 were also mapped. Bal 31 deletion mapping data suggested that one GATA-1 motif, one GT motif, and two NF-E2/AP1 motifs together formed the functional core of HS-40 in the erythroid-specific activation of the zeta 2 globin promoter. Site-directed mutagenesis further demonstrated that the enhancer function of one of the two NF-E2/AP1 motifs of HS-40 is mediated through its binding to NF-E2 but not AP1 transcription factor. Finally, we did genomic footprinting of the HS-40 enhancer region in K562 cells, adult nucleated erythroblasts, and different nonerythroid cells. All sequence motifs within the functional core of HS-40, as mapped by transient expression analysis, appeared to bind a nuclear factor(s) in living K562 cells but not in nonerythroid cells. On the other hand, only one of the apparently nonfunctional sequence motifs was bound with factors in vivo. In comparison to K562, nucleated erythroblasts from adult human bone marrow exhibited a similar but nonidentical pattern of nuclear factor binding in vivo at the HS-40 region. These data suggest that transcriptional activation of human embryonic zeta 2 globin gene and the fetal/adult alpha globin genes is mediated by erythroid cell-specific and developmental stage-specific nuclear factor-DNA complexes which form at the enhancer (HS-40) and the globin promoters.

Base Sequence↗
PubMed1993

Lumbosacral kinematics in the sagittal plane: a radiographic study in vivo.

Lateral functional radiographs of flexion and extension using Putto's method were examined in 89 normal subjects. A specially-designed radiopaque ruler was placed on each film for calibration. A computer-assisted method was used for digitization and analysis. There were weak negative correlations between age and range of motion, especially at the L4-L5 level (r = 0.437). No significant correlation was noted between age and translation. For flexion-extension rotation, although large variations may limit its usefulness in judging instability in some clinical settings, the data still provide a good diagnostic basis. For translation changes, 2 mm is regarded as acceptable in most cases at levels from L1 to L5, but not at the level of L5-S1 where the average translation change was only 0.4 mm. The differences in the absolute translation value among different positions were not statistically significant (p = 0.064).

Adult↗
PubMed1993

Effects of splenectomy, devascularization and esophageal transection on portal venous pressure and portal perfusion in cirrhotic patients with bleeding esophageal varices.

This investigation sought to determine the effects of splenectomy, devascularization and esophageal transection on portal venous pressure and portal perfusion in cirrhotic patients with a previous history of hemorrhage from esophageal varices. From June 1988 to June 1991, 54 patients with liver cirrhosis underwent this nonshunting procedure for esophageal varices. Of these patients, 24 patients (20 men and four women, 39 to 68 years of age, all in Child's class A) were examined for portal pressure before, during and after the nonshunting operations. Portal venous perfusion was assessed from the venous phase of the superior mesenteric arteriogram preoperatively and one year after surgery in 16 of these 24 patients. There was no significant change (p > 0.05) in cardiac output and systemic blood pressure after the operation. The portal venous pressure before surgery was 28.4 +/- 8.0 mmHg with a range from 18 to 44 mmHg. A statistically significant decrease (p < 0.05) in the portal pressure was observed after ligation of the splenic artery (26.6 +/- 8.9 mmHg), splenectomy (24.8 +/- 8.0 mmHg), and devascularization with transection (23.4 +/- 7.5 mmHg). No correlation between the portal pressure change and splenic weight was noted (p > 0.05). Postoperative portal perfusion remained the same or even improved in 15 of these 16 patients. Only in one patient was the portal perfusion worse after the operation; this patient developed encephalopathy about 18 months later. In conclusion, a significant reduction in portal pressure is noted after nonshunting procedures but a persistent, relatively high portal pressure is maintained. Good postoperative portal perfusion can also be maintained.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

The effects of putaminal hemorrhage upon motoneuron excitability.

To evaluate the putaminal influence on spinal motoneuron excitability, H-reflex recovery curve (HRRC) was studied in 24 patients with putaminal hemorrhage. Thirteen patients had increased facilitation, most significantly between 150 msec and 300 msec after the conditioning stimulus. It is proposed that putaminal dysfunction may cause an impairment in inhibition of soleus motoneuron excitability. Such a putaminal disinhibition is probably related to a disturbance of the thalamo-striatal and thalamic fasciculus circuits.

Adult↗
PubMed1992

Use of hematoma size on computerized tomography and calculated average bleeding rate as indications for immediate surgical intervention in blunt renal trauma.

One of the most demanding situations for a urologist is to decide which blunt renal trauma patients need immediate surgical exploration. Although computerized tomography can offer a lot of invaluable information, clear guidelines for selection of surgical versus conservative treatment are still lacking. A retrospective study of 15 blunt renal trauma cases showed that the hematoma size measured from computerized tomography using the method of summation planimetry bears a much closer correlation with the clinical outcome of the patient than does the degree of kidney parenchymal defect. Moreover, the average bleeding rate, calculated by dividing the size of the hematoma by the time elapsed from injury to scanning, gives a more accurate prediction for the need for immediate surgical treatment.

Adolescent↗
PubMed1992

Pancreas divisum with early pancreatic cancer--presenting as chronic obstructive pancreatitis.

A 61-year-old man experienced four bouts of pancreatitis in 1 year. Detailed history taking and a series of examinations, including sonography, computed tomography scan, and endoscopic retrograde cholangiopancreatography (ERCP), revealed pancreas divisum on the first admission. He was treated conservatively. However, repeated ERCP on the fourth admission, 1 year later, showed a small filling defect in the tail of the pancreatic duct. A distal pancreatectomy was carried out. Pathological studies revealed a small papillary adenocarcinoma (1.5 x 1.0 x 0.5 cm) confined to the pancreatic duct grossly with minimal parenchymal invasion microscopically. He has been free from cancer and pancreatitis for 13 months since the operation.

Adenocarcinoma↗