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Biomedical subjects

H Yu

Publications and source records attributed to H Yu.

At least 397 records · Page 22Linked to original sources
PubMed1998

Association between angiotensin II receptor gene polymorphism and serum angiotensin converting enzyme (SACE) activity in patients with sarcoidosis.

BACKGROUND: Serum angiotensin converting enzyme (SACE) is considered to reflect disease activity in sarcoidosis. SACE activity is increased in many patients with active sarcoid lesions. The mechanism for the increased SACE activity in this disease has not been clarified. ACE insertion/deletion (I/D) gene polymorphism has been reported to have an association with SACE levels in sarcoidosis, but no evidence of an association between angiotensin II receptor gene polymorphism and SACE in this disease has been found. A study of the association of angiotensin II receptor gene polymorphisms with sarcoidosis was therefore undertaken. METHODS: ACE (I/D), angiotensin II type 1 receptor (AGTR1), and angiotensin II type 2 receptor (AGTR2) gene polymorphisms were investigated by polymerase chain reaction (PCR) and SACE levels were measured in three groups of patients: those with sarcoidosis or tuberculosis and normal controls. RESULTS: There was no difference in allele frequency of AGTR1 and AGTR2 polymorphism among the three groups. Neither AGTR1 nor AGTR2 polymorphisms were associated with sarcoidosis. SACE activity was higher in patients with sarcoidosis with the AGTR1 A/C genotype than in others. However, this tendency was not detected in patients with tuberculosis. CONCLUSIONS: The AGTR1 allele C is associated with high activity of SACE in patients with sarcoidosis. It is another predisposing factor for high levels of SACE in patients with sarcoidosis and is considered to be an independent factor from the ACE D allele for high levels of SACE in sarcoidosis. This fact could be one of the explanations for the increased SACE activity in sarcoidosis.

Analysis of Variance↗
PubMed1998

Species variability in angiotensin receptor expression by cultured cardiac fibroblasts and the infarcted heart.

Cardiac fibroblasts, an abundant cell of the left ventricle (LV), proliferate and synthesize collagen in the heart after acute injury and during pressure overload hypertrophy. From many studies, angiotensin II (ANG II) receptors have been implicated in promoting collagen formation by the rat cardiac fibroblast. The present study examined species variability in ANG II receptor expression. Cultured rat fibroblasts expressed 43,000 +/- 15,000 ANG II (AT1-specific) receptors per cell (dissociation constant = 0.92 +/- 0.34 nM), whereas rabbit and neonate human cardiac fibroblast cultures expressed few receptors. Angiotensin increased intracellular Ca2+ concentration in rats but not in rabbit or human cardiac fibroblasts and stimulated arachidonic acid release in rat but not rabbit fibroblasts. In situ, 6 days after coronary artery ligation, angiotensin receptor expression was increased 34.8 +/- 13.4-fold in the infarcted area relative to the noninfarcted tissue in the rat LV, whereas rabbit hearts demonstrated only a 3.2 +/- 1.6-fold increase in ANG II binding within the infarcted tissue. These species differences in receptor expression raise questions as to the role of angiotensin as a mediator of collagen formation across species and as a direct target of angiotensin-converting enzyme inhibitors to regulate cardiac fibroblast function.

Angiotensin II↗
PubMed1998

Pilomotor seizures.

We report pilomotor seizures in two patients who had piloerection or gooseflesh spreading in a pattern like the 'Jacksonian march', confined ipsilaterally to the lesion side. The first patient presented this in conjunction with complex partial seizures. Left anterior temporal lobectomy abolished pilomotor and other seizures. Pathological study demonstrated hippocampal sclerosis. A meningioma near the left sphenoid region, incompletely removed, is the likely cause of pilomotor seizures in the second patient. Carbamazepine reduced these attacks. To our knowledge, hippocampal sclerosis and meningioma have never been linked to pilomotor seizures.

Adult↗
PubMed1998

Identification of human plasma kallikrein gene polymorphisms and evaluation of their role in end-stage renal disease.

Kallikreins are serine proteases that release kinins from kininogens. Kinins, via their effects on cardiovascular and renal function, may be involved in the pathogenesis of hypertension and renal failure. Two groups of kallikreins exist, glandular or tissue kallikrein and plasma kallikrein. In this study, we examined the human plasma kallikrein gene KLK3 to determine whether it contributed to end-stage renal disease (ESRD) susceptibility. We identified two novel polymorphic sequences closely linked to the KLK3 gene, designated KLK3b and KLK3c (heterozygosities: 0.64 to 0.68 and 0.48 to 0.52, respectively). We mapped the KLK3 gene and the marker KLK3c to the long arm of human chromosome 4 between F11 and D4S426 using a radiation hybrid panel. The study population consisted of 142 sibling pairs concordant for ESRD from 121 African American families. The 142 sibling pairs were stratified into 78 pairs with hypertension- and chronic glomerulonephritis-associated ESRD and 64 with non-insulin-dependent diabetes mellitus-associated ESRD. Linkage analyses, using SIBPAL of SAGE, and exclusion analysis, using MAPMAKERS/SIBS, were performed. Linkage analysis of affected sibling pairs did not reveal any evidence of linkage of KLK3 to ESRD in all 142 sib-pairs or in the two stratified subsets. Exclusion analysis indicated that the KLK3 gene could be excluded from contributing to ESRD at a relative risk of 3 when the maximum log of the odds score of -2 was used as the criterion for exclusion. However, an association analysis using the relative predispositional effect technique showed that alleles 7 and 9 of KLK3b were consistently associated with ESRD. Alleles 7 and 9 were present in 11.2% and 10.8% of the 113 unrelated ESRD probands and in 6.6% and 6.6% of the 204 race-matched control subjects without renal disease (allele P=.0041 and .0016, respectively). Alleles 7 and 9 were also present in 13% and 10.4% of the proband's first siblings (allele P=.00014 and .0087, respectively). The association of KLK3b alleles with ESRD raises the possibility that polymorphisms in KLK3 may play a role in ESRD susceptibility. The lack of linkage might reflect our relatively small family set.

Alleles↗
PubMed1998

Bradykinin-induced reductions in collagen gene expression involve prostacyclin.

Cardiac fibrosis after myocardial infarction and in chronic hypertension involves an increase in the synthesis and deposition of collagen within the myocardium. Angiotensin-converting enzyme (ACE) inhibitors limit hypertrophy and fibrosis; their mechanism of action remains controversial, although kinins have been implicated to play a role. Because both bradykinin and prostaglandins (PG) have been shown to reduce collagen gene expression in cardiac fibroblasts, the goal of this study was to determine whether the bradykinin effect was mediated through enhanced prostaglandin formation by cardiac fibroblasts. Bradykinin increased [3H]arachidonic acid metabolite release 2.3-fold over control and stimulated a dose-dependent increase in 6-keto PGF1alpha (the stable metabolite of PGI2) release from these cells, in which 1 nmol/L bradykinin produced a 4-fold increase in 6-keto PGF1alpha release. Beraprost (a PGI2 analogue) reduced steady-state proalpha1(I) and proalpha1(III) collagen mRNA levels by 35.6+/-6.6% and 34.2+/-10.0%, respectively. Bradykinin-induced reductions in collagen type I and III gene expression were reversed by pretreatment with indomethacin. Our results indicate that one mechanism by which bradykinin modulates collagen biosynthesis via the rabbit cardiac fibroblast involves formation of arachidonic acid metabolites, particularly PGI2. The results of the present study argue that stabilization of endogenous kinins (as by ACE inhibitors) would enhance prostacyclin production and result in the attenuation of collagen gene expression, with potential implications for collagen synthesis and deposition within the myocardium.

Animals↗
PubMed1998

Biphasic effect of bradykinin on rabbit afferent arterioles.

Bradykinin plays an important role in the regulation of renal hemodynamics. However, there have been few studies of the effect of bradykinin on isolated afferent arterioles, vascular segments that are important for the regulation of renal blood flow and glomerular filtration rate. Our purpose was to study (1) the effects of bradykinin on isolated perfused rabbit afferent arterioles and (2) the mechanisms of actions. Afferent arterioles dissected from rabbits were perfused in vitro at 60 mm Hg. In afferent arterioles preconstricted with phenylephrine, 10(-12) to 10(-10) mol/L bradykinin increased luminal diameter from 9.0+/-1.0 to 14.3+/-1.2 microm (P<0.003). In contrast, 10(-9) and 10(-8) mol/L bradykinin decreased luminal diameter to 10.8+/-1.4 and 9.7+/-1.2 microm, respectively (P<0.001). Bradykinin added to the bath had no effect on preconstricted afferent arterioles. The addition of [des-Arg9]-bradykinin (10(-9) and 10(-8) mol/L), a B1 receptor agonist, to the lumen decreased diameter from 9.7+/-1.2 to 6.7+/-1.2 microm at 10(-8) mol/L (P<0.002). Icatibant (Hoe 140), a B2 receptor antagonist, blocked both the vasodilation and vasoconstriction induced by bradykinin as well as the vasoconstriction induced by [des-Arg9]-bradykinin. L-NAME had no effect on bradykinin-induced dilation or constriction. Indomethacin blocked both the dilation induced by 10(-12) to 10(-10) mol/L bradykinin and the constriction induced by 10(-9) to 10(-8) mol/L bradykinin. In fact, in the presence of indomethacin, 10(-9) and 10(-8) mol/L bradykinin increased luminal diameter from 6.2+/-0.7 to 10.7+/-0.6 microm at 10(-8) mol/L (P<0.001), which was attenuated by L-NAME. Finally, in the presence of SQ29548, a prostaglandin H2/thromboxane A2 receptor antagonist, bradykinin caused dilation at all concentrations tested. In conclusion, bradykinin has a biphasic effect on afferent arterioles. Both dilation and constriction may be mediated by bradykinin B2 receptors. The mechanisms of vasodilation and vasoconstriction are due to cyclooxygenase products, not nitric oxide.

Animals↗
PubMed1998

Enzyme-linked immunoabsorbent assay-detected p53 protein accumulation: a prognostic factor in a large breast cancer cohort.

PURPOSE: This study was designed to evaluate whether patients with an unfavorable breast cancer prognosis could be identified by p53 protein overexpression detected by a quantitative enzyme-linked immunoabsorbent assay (ELISA). PATIENTS AND METHODS: Extracts from 998 breast carcinomas were assayed for p53 protein by an ELISA that used both DO-1 monoclonal and CM-1 polyclonal antibodies. Relative risks (RRs) for cancer relapse and death after 6 years of follow-up for patients with p53-positive tumors based on different dichotomization criteria were determined by multivariate Cox regression, adjusted for patient age, tumor size, S-phase fraction, estrogen (ER) and progesterone (PR) receptor concentrations, DNA ploidy, and lymph node metastases. Disease-free (DFS) and overall (OS) survival probabilities of p53-positive and p53-negative groups, using a median cutoff, were also estimated by the Kaplan-Meier method and the log-rank test. These analyses were performed for all patients and for subgroups defined by ER status, node status, and primary postoperative treatment. RESULTS: Univariate analysis showed that p53 concentrations that exceeded the median indicated significantly increased risks for relapse (P < .01) and death (P = .02). Multivariate analyses confirmed these observations (RR = 1.40; P = .02 for DFS and RR = 1.50; P < .01 for OS) and showed trends for increasing risks for relapse (P = .02) and death (P = .06) when p53 was considered as a four-level categoric variable, and identified p53 positivity as a significant predictor of outcome in node-positive patients (RR = 1.67; P < .01 and RR = 2.10; P < .01 for DFS and OS, respectively), ER-positive patients (RR = 1.45; P = .02 and RR = 1.50; P = .01 for DFS and OS, respectively), and in patients treated with chemotherapy (RR = 1.73; P = .04 for relapse and RR = 2.04; P = .03 for death). CONCLUSION: Assessment of p53 overexpression by ELISA, easily incorporated into the routine biochemical work-up of breast tumors, may be an independent predictor of reduced survival of breast cancer patients.

Adult↗
PubMed1998

The acid-labile subunit of human ternary insulin-like growth factor binding protein complex in serum: hepatosplanchnic release, diurnal variation, circulating concentrations in healthy subjects, and diagnostic use in patients with growth hormone deficiency.

Circulating insulin-like growth factor-I (IGF-I) is predominantly bound in the trimeric complex comprised of IGF binding protein-3 (IGFBP-3) and acid-labile subunit (ALS). Circulating concentrations of IGF-I, IGFBP-3 and ALS are believed to reflect the GH secretory status, but the clinical use of ALS determination is not known. We therefore, determined the: 1) hepatosplanchnic release of ALS by liver vein catheterization (n=30); 2) 24-h diurnal variation of ALS (n=8); 3) normal age-related ranges of circulating ALS (n=1158); 4) diagnostic value of ALS in 108 patients with childhood-onset GH deficiency (GHD). We found: 1) no significant arteriovenous gradient over the liver ofALS, IGF-I, and IGFBP-3; 2) the diurnal variation of ALS was 12% (mean coefficient of variation percent); 3) ALS levels increased throughout childhood with maximal levels in puberty, with a subsequent decrease with age in adults; and 4) ALS levels were below -2 SD in 57 of 79 GHD patients (sensitivity 72%) and above 2 SD in 22 of 29 patients with normal GH response (specificity 76%), which was similar, compared with the diagnostic utility of IGF-I and IGFBP-3. Finally, our findings indicate that hepatic ALS production is not measurable by this approach or, alternatively, that the liver is not the primary source of circulating ALS, IGF-I, or IGFBP-3 in humans. In conclusion, we have provided extensive normal data for a novel ALS assay and found that circulating ALS levels exhibit minor diurnal variation. We suggest that ALS determination may be used in future classification of adults suspected of GHD.

Adolescent↗
PubMed1998

Altered nuclear protein binding to the first intron of the renin gene of the spontaneously hypertensive rat.

We and others have reported elevated levels of renin mRNA in extrarenal tissues of the spontaneously hypertensive rat (SHR) of the Okamoto strain. We hypothesise that this is due to mutations we have found in putative, cis-regulatory regions in the first intron of its renin gene. Here we report two G-A mutations at position +502 and +934 of the first intron of the SHR renin gene, when compared to normotensive Wistar Kyoto (WKY) and Sprague Dawley (SD) rats. These mutations fall within consensus sequences for the well described E2A and peroxisome proliferator-activated receptor (PPAR) transcription factors. We used electrophoretic mobility shift assays to determine if these mutations alter the pattern or affinity of nuclear protein binding to oligonucleotides homologous to these regions of the renin gene. Both mutations significantly altered the intensity and pattern of nuclear protein binding to oligonucleotides homologous with the renin gene regions bearing these putative transcription factor binding sites. Thus these mutations have the potential to alter the type and/or affinity of transcriptional factors for the SHR renin gene in vivo, and result in renin overproduction at an extra-renal tissue site subserving blood pressure control.

Animals↗
PubMed1998

Transurethral prostate vaporization using an oval electrode in 82 cases of benign prostatic hyperplasia.

OBJECTIVE: To present our initial experience in transurethral vaporization of the prostate (TVP) using an oval electrode for the treatment of benign prostatic hyperplasia (BPH). METHODS: A total of 82 patients underwent TVP procedures with the oval electrode. The newly designed oval-shaped electrode can work with a High Frequency Electrosurgery Unit. Prostate gland tissue was vaporized through an Fr 24 percutaneous nephroscope transurethrally. The operation procedure was similar to transurethral resection of the prostate (TURP) or transurethral laser prostatectomy (TULP). Power setting ranged from 240 W to 320 W. Local vaporization temperature reached 120 degrees C. RESULTS: Urination was recovered in all 82 patients after TVP. Mean post-treatment International Prostate Symptom Score (I-PSS) reduced from 27.10 to 5.05; mean bladder residual urine volume dropped from 147.71 ml to 33.2 ml; and mean urine flow rate (MFR) increased from 4.45 ml/s to 14.57 ml/s (P < 0.01). The initial results of short-term follow-up were excellent. CONCLUSIONS: TVP with the oval electrode is easy to perform and causes less hemorrhage and few complications. It especially benefits elderly and/or critically-ill patients. We believe that TVP with our oval electrode is feasible with low risk.

Aged↗
PubMed1998

Development of serial bio-shock tubes and their application.

OBJECTIVE: To design and produce serial shock tubes and further examine their application to experimental studies on blast injury. METHODS: Bio-medical engineering technique was used for the design and development of the serial shock tubes. One thousand four hundred and fifty nine animals (757 rats, 105 guinea pigs, 335 rabbits, 240 dogs and 22 sheep) were then used to test the wounding effects of the shock tubes. RESULTS: Three types of bio-shock tubes, that is, large-, medium- and small-scale shock tubes were made in our laboratory. The large-scale shock tube is 39 meters long; the inner diameter of the test section is 1 meter; and the maximum overpressure in the driving section is 10.3 MPa. A negative pressure could be formed by means of the reflected rarefactive wave produced by the end plate. The medium-scale shock tube is 34.5 meters long; the maximum overpressure in the driving section is 22 MPa; the test section is designed to be a knockdown, showing 5 basic types with inner diameter of 77 to 600 millimeters, which could be used for researches on overpressure, explosive decompression, underwater explosion, and so on. The small-scale shock tube is 0.5 meter long with the maximum endured overpressure of 68.6 MPa. Results from animal experiments showed that this set of shock tubes could induce various degrees of systemic or local blast injury in large or small animals. CONCLUSIONS: This set of bio-shock tubes can approximately simulate typical explosive wave produced by nuclear or charge explosion, and inflict various degrees of blast injury characterized by stability and reproducibility. Therefore, they can meet the needs of blast research on large and small animals.

Animals↗
PubMed1998

Crossroads of the effects of cyclophosphamide pulse therapy for lupus nephritis--experience of 11 cases.

In this study time for initial assessment of monthly intravenous cyclophosphamide (CP) pulse therapy is discussed for a better outcome with less complications. Eleven patients with lupus nephritis (LN) resistant to conventional therapy (serum creatinine level < or = 2.7 mg/dl) were given 500 mg/m2 of CP 7-9 times with an interval of one month. Urinary protein (Up) decreased in all patients after 3 courses of CP pulse therapy and kept similar levels thereafter. In one group of patients (n = 7), Up decreased to < 2 g/day after 3 courses, while in the other group (n = 4), it did not decrease to < 4 g/day. Creatinine clearance increased by 0-100% in the former group, while it decreased by 5-20% in the latter group after 6-9 courses. Renal function of the patients with insufficient response after 3 courses tended to show no further improvement or worsened thereafter, although Up decreased during CP pulse therapy. A relatively small dose of CP (500 mg/m2) pulse therapy was useful in most LN patients regardless of the renal histology and it was thought important to assess its effects after 3 courses for a prediction of the clinical course. Modification of the protocol at that time might be necessary in regard to dose or interval of CP administration especially for patients with insufficient outcome.

Adult↗
PubMed1998

[Application of antigen linked with chemicals on nitrate cellulose membrane for dot-enzyme immunoassay].

HCMV-IgG in sera of pregnant women was detected by means of dot-enzyme immunoassay (DEIA), in which antigen was cross-linked on nitrate cellulose membrane through chemical reagent. The results showed better repetition by DEIA, compared with ELISA, and no significant differences were noted between the two methods in the rates of detecting HCMV-IgG in positive, weak positive and negative sera. The rate of agreement was 93.2%. In examining the sera which had been examined by ELISA for three times with the same, results the sensitivity, specificity, index and efficiency of diagnosis by DEIA were 100%, 96.6%, 196.6% and 98.7% respectively. Since this method is convenient, fast, of good repetition, economical and its diagnosis index meets the application criterion, it is more suitable for clinical laboratories.

Cellulose↗
PubMed1998

[Diagnosis and treatment of thoracic outlet syndrome].

OBJECTIVE: Thoracic outlet syndrome (TOS) is clinically common, but liable to be misdiagnosed. We would like to emphasize the recognition of TOS, and through thorough examination for a complete relief from indicated operation. METHODS: 13 cases receiving surgical operations in PUMC hospital from 1982 to 1996 are reported and discussed the cause of misdiagnosis, investigate the various kinds of abnormalities and compare the result of operation. RESULTS: 92% of the patients had experence of being misdiagnosed for other diseases, the history may be as long as 10 years. In the operations we found 8 kinds of anatomic abnormalities that cause the symptoms and complete relief is satisfactory. CONCLUSIONS: We have to emphasize the recognition of TOS. The thorough physical examination is important to diagnosis. Patients with typical and apparent symptoms need an operation to relieve the thoracic outlet through the transaxillary approach.

Adolescent↗
PubMed1998

[Subxiphoid pericardial window drainage in the management of large pericardial effusions].

OBJECTIVE: To choose a safe, effective, minimum invasive procedure for treatment of patients with a large pericardial effusion and cardiac tamponade. METHODS: Retrospective analysis of 30 cases with large pericardial effusion or cardiac tamponade diagnosed by echocardiography during four years (1993-1997). The subxiphoid pericardial window drainage and pericardial tissue biopsy was performed. RESULTS: The symptoms were improved immediately following the drainage. The drainage volume during operation was 200-2,000 ml, and postoperation was 0-2,000 ml. The drainage tube was kept in position for average of 5.6 days. With the echocardiography follow up, the pericardial effusion disappeared or remained only minimum fluid in 96.7% of the patients. The complications happened in 6 cases. The 30-days mortality was 6.7%. CONCLUSIONS: The subxiphoid pericardial window drainage procedure is the first choice for a safe, effective, minimal invasive and easy to do procedure for the patients with a large pericardial effusions or cardiac tamponade.

Adolescent↗
PubMed1998

[The relationship of facet orientation to intervertebral disc protrusion and lateral recess stenosis in lower lumbar spine].

OBJECTIVE: To investigate the relationship of facet orientation to intervertebral disc protrusion and lateral recess stenosis in lower lumbar spine. METHOD: The relationship between facet geometry (joint angle and tropism) and disc protrusion, lateral recess stenosis was investigated with computer tomography (CT) at the vertebral levels L(3 - 4), L(4 - 5), and L(5) - S(1). 772 facet joint angles (386 lower lumbar levels of 136 patients) were measured on coronal CT scans by transverse inter-facet angle (TIFA). RESULT: There was no statistically significant relationship between facet joint asymmetry and disc protrusion (P > 0.05). Disc protrusion occurred more frequently on side of sagittally oriented facet joint than coronal side (P < 0.01). The patients whose lumbar transverse inter-facet angle less than 20 degrees easily suffered from degenerative lumbar lateral recess stenosis in the elderly. The TIFA in Asian less evident than in European may be the important cause for high incidence of lumbar lateral recess syndrome in Asia. CONCLUSION: Stress on the lower lumbar spine leads to disc protrusion. No association is found between facet joint asymmetry and lumbar disc protrusion. The asymmetry of facet joint will influence the direction of intervertebral disc protrusion at level from L(4) - S(1). The patient whose lower lumbar spine inter-facet angle may unlikely suffer from degenerative lumbar lateral recess stenosis.

Adolescent↗