Biomedical subjects

C C Chen

Publications and source records attributed to C C Chen.

At least 271 records · Page 15Linked to original sources

PubMed1997

Effects of age and hypertension on endothelium-dependent vasodilating responses.

To investigate whether the release of endothelium-derived relaxing factors (EDRF) was affected during the development of hypertension or by age, male spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY) in the age of 4, 8, 12, 24, 36 or 48 weeks old were used for this study. The thoracic aorta and superior mesenteric arteries of these animals with different ages were excised after general anesthesia. In addition to the measurement of basal EDRF release, vascular responses to acetylcholine (ACh) were assessed with or without the treatment of various inhibitors (such as N omega-nitro-L-arginine, SQ29548 or 3-amino-1,2,4-triazole) to clarify the possible mechanisms for changes of ACh-evoked vasorelaxation. We found that 1) the basal release of EDRF was declined during the development of hypertension, especially in the mesenteric arteries; 2) ACh-induced vasorelaxation in the thoracic aorta was mainly due to the stimulated release of nitric oxide, whereas the effect of endothelium-derived hyperpolarizing factor was more prominent in the mesenteric arteries than in thoracic aortae; 3) high concentrations of ACh stimulated the release of endothelium-derived contracting factors in the thoracic aorta of SHR and WKY of 24 weeks or older, and in the mesenteric arteries of 48-week-old SHR. In conclusion, basal release of EDRF decreases before hypertension is well established, and the impairment of ACh-evoked vasorelaxation in adult SHR is mainly due to the release of contracting factors.

Acetylcholine↗

PubMed1997

TPA induces translocation but not down-regulation of new PKC isoform eta in macrophages, MDCK cells and astrocytes.

New type protein kinase C (PKC) eta was found to be expressed in RAW 264.7 and J774A.1 macrophages, Madin-Darby canine kidney (MDCK) cells and astrocytes by Western blot analysis. Both cytosol and membrane in macrophages and astrocytes express this isoform, however, the expression in the membrane is more abundant than that in the cytosol. On the other hand, only membrane PKC eta was detected in MDCK cells. Exposure of the cells to 1 microM TPA for 10 min resulted in the translocation of PKC eta from the cytosolic to the membrane fraction. This translocation maintained at a constant level after 1.5, 3, 6 and 24 h TPA treatment. However, another new type PKC delta which expressed in the macrophages and astrocytes was down-regulated after long-term (6 and 24 h) TPA treatment. The immunoreactive band of PKC eta in J774A.1 macrophages was blocked by the control PKC eta antigenic peptide. Incubation of RAW 264.7 macrophages with UTP (1, 10 and 100 microM) resulted in the accumulation of inositol phosphates, indicating the presence of P2 receptor-coupled PLC pathway in these cells. This natural activator UTP also induced translocation of PKC eta from cytosol to the membrane in RAW 264.7 macrophages after 1, 5 or 10 min treatment. Immunofluorescence microscopy revealed that in RAW 264.7 cells, PKC eta is located in the cytoplasm organelle, plasma membrane and nuclear envelope. Stimulation of the cells with TPA resulted in translocation to the plasma membrane. This translocation of PKC eta was still apparent after 24 h treatment with TPA.

Animals↗

PubMed1997

Mechanism of oxidative stress-induced intracellular acidosis in rat cerebellar astrocytes and C6 glioma cells.

1. Following ischaemic reperfusion, large amounts of superoxide anion (.O2-), hydroxyl radical (.OH) and H2O2 are produced, resulting in brain oedema and changes in cerebral vascular permeability. We have found that H2O2 (100 microM) induces a significant intracellular acidosis in both cultured rat cerebellar astrocytes (0.37 +/- 0.04 pH units) and C6 glioma cells (0.33 +/- 0.07 pH units). 2. Two membrane-crossing ferrous iron chelators, phenanthroline and deferoxamine, almost completely inhibited H2O2-induced intracellular acidosis, while the non-membrane-crossing iron chelator apo-transferrin had no effect. Furthermore, the acidosis was completely inhibited by two potent membrane-crossing .OH scavengers, N-(2-mercaptopropionyl)-glycine (N-MPG) and dimethyl thiourea (DMTU). Since .OH can be produced during iron-catalysed H2O2 breakdown (Fenton reaction), we have shown that a large reduction in pH1 in glial cells can result from the production of intracellular .OH via H2O2 oxidation. 3. We have ruled out the possible involvement of: (i) an increase in intracellular Ca2+ levels; and (ii) inhibition of oxidative phosphorylation. 4. Our results suggest that .OH inhibits glycolysis, leading to ATP hydrolysis and intracellular acidosis. This conclusion is based on the following observations: (i) in glucose-free medium, or in the presence of iodoacetate or 2-deoxy-D-glucose, H2O2-induced acidosis is completely suppressed; (ii) H2O2 and iodoacetate both produce an increase in levels of intracellular free Mg2+, an indicator of ATP breakdown; and (iii) direct measurement of intracellular ATP levels and lactate production show 50 and 55% reductions in ATP content and lactate production, respectively, following treatment with 100 microM H2O2. 5. Inhibition of the pH1 regulators (i.e. the Na(+)-H+ exchange and possibly the Na(+)-HCO3(-)-dependent pH1 transporters) resulting from H2O2-induced intracellular ATP reduction may also be involved in the H2O2-evoked intracellular acidosis in glial cells.

Acidosis↗

PubMed1997

Cyr61 and Fisp12 are both ECM-associated signaling molecules: activities, metabolism, and localization during development.

cyr61 and fisp12 are homologous immediate-early genes that are transcriptionally activated upon growth factor stimulation in fibroblasts. Their gene products belong to an emerging family of secreted proteins with a high degree of sequence homology, including conservation of all 38 cysteine residues in their secreted portions. We have recently shown that Cyr61 is an extracellular matrix (ECM) signaling molecule that promotes cell proliferation, migration, and adhesion. We describe herein the first purification of the Fisp12 protein and we compare the activities of purified Cyr61 and Fisp12, their metabolism, targeting, and their localization during development. Although Fisp12 is the mouse homolog of the human connective tissue growth factor (CTGF), it has no detectable mitogenic activity by itself. Rather, Fisp12 enhances fibroblast growth factor-induced DNA synthesis. The activities of Fisp12 and Cyr61 are nearly indistinguishable in three cell types tested: fibroblasts, endothelial, and epithelial cells. Both proteins are found in the ECM, although Cyr61 associates with the ECM more strongly and binds heparin with higher affinity. Fisp12, but not Cyr61, is also found in the culture medium, suggesting that Fisp12 might be able to act at a distance from its site of secretion, whereas Cyr61 might act more locally. Both secreted proteins are internalized and degraded through the lysosomal pathway, suggesting interaction with cell surface receptors. Both Cyr61 and Fisp12 are found in the placenta and the circulatory system as detected by immunohistochemistry, whereas Cyr61, but not Fisp12, is found in the skeletal and nervous systems. Fisp12, but not Cyr61, is found in secretory organs. Taken together, we propose that Cyr61 and Fisp12 are both signaling cell adhesion molecules that have similar or overlapping activities, and their differential sites of localization and targeting may dictate specificity in their biological roles.

3T3 Cells↗

PubMed1997

Distinctions between CD8+ and CD4+ T-cell regenerative pathways result in prolonged T-cell subset imbalance after intensive chemotherapy.

Rapid recovery of CD4+ T cells after intensive chemotherapy is limited by an age-dependent decline in thymopoiesis. Here we sought to determine whether similar limitations exist for CD8+ T-cell regeneration. After intensive chemotherapy, CD8+ T cells had a faster effective doubling time than CD4+ T cells (median, 12.6 v 28.2 days, P < .05). Accordingly, at 3 months posttherapy, mean CD8+ T-cell number had returned to baseline, whereas mean CD4+ T-cell number was only 35% of pretherapy values (P < .05). These differences were primarily due to very rapid expansion of CD8+CD57+ and CD8+CD28- subsets. At 3 months posttherapy, there was no relationship between age and CD8+ T-cell number (R = -.02), whereas CD4+ T-cell number was inversely related to age (R = -.66) and there were no discernible differences in CD8+ recovery among patients with or without thymic enlargement, whereas CD4+ recovery was enhanced in patients with thymic enlargement after chemotherapy (P < .01). Therefore thymic-independent pathways of T-cell regeneration appear to rapidly regenerate substantial numbers of CD8+, but not CD4+ T cells, resulting in prolonged T-cell subset imbalance after T-cell depletion. These inherent distinctions between CD4+ v CD8+ T-cell regeneration may have significant implications for immunotherapeutic strategies undertaken to eradicate minimal residual neoplastic disease after cytoreductive chemotherapy.

Adolescent↗

PubMed1997

High-dose-rate intracavitary brachytherapy (HDR-IC) in treatment of cervical carcinoma: 5-year results and implication of increased low-grade rectal complication on initiation of an HDR-IC fractionation scheme.

PURPOSE: To report the treatment results and rectal/bladder complications of cervical carcinoma radically treated with high-dose-rate intracavitary brachytherapy (HDR-IC). The current policy of using three-fraction scheme was examined. METHODS AND MATERIALS: Between November 1987 and August 1990, 173 patients with cervical carcinoma were treated with curative-intent radiation therapy. Whole pelvic irradiation was administered with 10-MV X ray. Dose to the central cervix was 40-44 Gy in 20-22 fractions, following by pelvic wall boost 6-14 Gy in three to seven fractions with central shielding. 60Co sources were used for HDR-IC, and 7.2 Gy was given to Point A for three applications, 1-2 weeks apart. Duration of follow-up was 5-7.8 years. RESULTS: Twenty-eight patients (16%) developed central-regional recurrences. Overall 5-year actuarial pelvic control rate was 83%. By stage, 5-year actuarial pelvic control rates were 94%, 87%, and 72% for Stages IB + IIA, IIB + IIIA, and IIIB + IVA, respectively. Thirty-one patients (18%) developed distant metastasis. Overall 5-year actuarial survival rate was 58%. By stage, 5-year actuarial survival rates were 79%, 59%, and 41% for Stages IB + IIA, IIB + IIIA, and IIIB + IVA, respectively. Sixty-six (38%) and 19 patients (11%) developed rectal and bladder complications, respectively. For rectal complication, the overall actuarial rate was 38% at 5 years. By grade, 5-year actuarial rectal complication rates were 24%, 15%, 4%, and 3% for Grades 1-4, respectively. Overall prevalence of rectal complications was 37% and 14% at 2 and 5 years, respectively. Prevalence of low-grade rectal complication (Grades 1 and 2) was dominant at 2 years (30%), but declined to 8% at 5 years. Prevalence of high-grade, severe rectal complication (Grades 3 and 4) remained steady at 2 and 5 years (7% and 6%, respectively). Five-year actuarial bladder complication was 9%. Five-year prevalence of bladder complication was 2%. CONCLUSION: Using a three-fraction scheme, survival rate appeared comparable with the existing results of the low-dose-rate technique. The incidence of rectal complication with this scheme remained relatively high. The increased part of rectal complication was predominantly low grade. This result suggested that therapeutic gain with this scheme may not be good enough to circumvent its biologic disadvantage. Numbers of fractions >3 must be considered in future trials.

Adenocarcinoma↗

PubMed1997

Dopamine D2 receptor gene and alcoholism among four aboriginal groups and Han in Taiwan.

Previous studies examining the putative association between DRD2 TaqI A1 and alcoholism have produced conflicting results. Major critiques of such studies include potential confounding arising from population admixture by inappropriate selection of controls, failure to screen out substance abusers from controls, and the failure to assess the severity of alcoholics. To address these issues, we compared the allelic frequency of two polymorphisms of DRD2, TaqI A and NcoI, among severe alcoholics and their ethnically matched nonalcoholic controls within four major aboriginal groups and Han (Chinese) in Taiwan. The sample of alcoholics and controls examined for the five groups included 36 and 31 (Atayal), 24 and 23 (Ami), 58 and 58 (Bunun), 35 and 35 (Paiwan), and 50 and 66 (Han). A borderline association between TaqI A1 and alcoholism among the Ami (P = 0.08) and an association between NcoI N1 and alcoholism among Han (P = 0.01) were found. Results of haplotype analysis further confirm that the frequency of haplotype A1N1 was higher in alcoholics than in controls for the Ami (P = 0.01) and Han (P = 0.03). If controls with tobacco abuse were excluded from the analysis, the results remained unchanged. Severity in medical complications of alcohol dependence with withdrawal symptoms was not associated with higher prevalence of DRD2 TaqI A1 or NcoI N1 alleles. The absence of an association between DRD2 and alcoholism among the three aboriginal groups suggests either a higher rate of phenocopies among aboriginal alcoholics or genetic heterogeneity in the susceptibility to alcoholism.

Alcoholism↗

PubMed1997

A role for calcineurin in the desensitization of the P2X3 receptor.

The sensory neurone-specific ATP-gated cation channel P2X3, when expressed in Xenopus oocytes, desensitizes rapidly. Complete removal of extracellular calcium abolishes desensitization. Pretreatment of oocytes with cyclosporin also abolishes P2X3 desensitization. When the calcineurin auto-inhibitory peptide (CaN A457-481) was injected into oocytes, the rate of desensitization of P2X3 decreased on consecutive applications of ATP, suggesting a role for calcineurin in the regulation of desensitization. Truncated P2X3 clones initiating at Met-75 lack the N-terminal intracellular region, but express functional channels in oocytes that do not desensitize. Taken together, these data suggest that P2X3 desensitizes through a calcium-dependent calcineurin-mediated dephosphorylation involving N-terminal residues that are phosphorylated in functional channels.

Animals↗

PubMed1997

Right-sided cardiac tumors detected by transesophageal echocardiography and its usefulness in differentiating the benign from the malignant ones.

Eighteen patients (3 men and 15 women; mean age 63 years) with right-sided tumors were evaluated by both transthoracic and transesophageal echocardiography from 1989 to 1996. The indications for echocardiographic studies included evaluation for a presumed mass and further evaluation of ventricular function and valvular function. Fifteen patients had right atrial tumors. These included 5 hypernephromas, 4 myxomas, 2 angiosarcomas, 1 lipoma, 1 cavernous hemangioma, 1 hepatoma, and 1 chondrosarcoma. Three patients had right ventricular (RV) tumors: 1 metastatic olfactory neuroblastoma, a leiomyosarcoma, a chondrosarcoma, and a fourth patient had infiltration of the RV free wall of unknown etiology. Biopsy of either right atrial or RV masses was performed with transesophageal echocardiographic guidance in 2 patients, and allowed histologic diagnosis before surgical resection. These findings indicate that tumors are more often found in the right atrium than in the right ventricle, and females predominate. Most tumors arising within the right atrium are benign, whereas those extending into the right atrium from outside are malignant. RV tumors are rarely encountered; when present, they are likely to be malignant.

Adult↗

PubMed1997

Expression and regulation of mRNA for inhibin/activin alpha- and betaA-subunits in the granulosa layer of the two largest preovulatory follicles during the hen ovulatory cycle.

In order to understand the role of inhibin and activin in regulating follicular development in the hen, the steady-state mRNA levels of inhibin/activin alpha- and betaA-subunits in the granulosa layer of the largest (F1) and second largest (F2) follicles of the hen were investigated at 4-hr intervals throughout the ovulatory cycle. In addition, because it was hypothesized that luteinizing hormone (LH) regulated betaA-subunit expression, the effect of in vivo administration of ovine LH (oLH) on the expression of these subunits during the early- and mid-ovulatory cycle was examined. Northern blot analysis, using 32P-labeled cDNA probes of chicken inhibin/activin alpha- and betaA-subunits and glyceraldehyde-3-phosphate dehydrogenase (GAPDH, internal control), revealed that in the F1 follicle, the relative level of betaA-mRNA (n = 3) was low at 23.5 hr and increased (P < 0.05) at 19.5, 15.5, and 11.5 hr before the next predicted ovulation. It then decreased (P < 0.05) at 7.5 hr and was further reduced at 3.5 and 0.5 hr prior to ovulation. In the F2 follicle, betaA-mRNA was maintained at a basal level throughout the sampling period except for a brief increase (P < 0.05) at 0.5 hr before ovulation. In contrast to the betaA-subunit, inhibin alpha-mRNA was abundantly expressed with no significant variations throughout the ovulatory cycle in either the F1 or the F2 follicle. When oLH was injected at 18 hr before ovulation, 200 but not 100 or 50 microg/kg (n = 3 hens per dose) significantly (P < 0.05) reduced the betaA-mRNA level in the F1 follicle by 2 hr after injection compared to the control (saline). The experiment was repeated at 12 hr before ovulation and both 100 and 200 but not 50 microg/kg oLH significantly (P < 0.05) reduced the expression of betaA-subunit mRNA with no significant difference between 100 and 200 microg/kg oLH. In contrast to the betaA-subunit, inhibin alpha-subunit mRNA was abundantly expressed and not affected by oLH treatment. Our data indicate that the expression of inhibin/activin betaA- but not alpha-subunit mRNA is developmentally regulated in the granulosa layer of the two largest follicles during the hen ovulatory cycle. In addition, LH may participate, directly or indirectly, in negative regulation of the betaA-subunit.

Activins↗

PubMed1997

Urine lipids in patients with a history of filariasis.

The presence of lipids in postprandial urine was assessed in 116 patients with a history of filariasis and 70 normal individuals using a biochemical autoanalyzer. Urinary triglycerides (TGs) ranging from 10 to 1955 mg/dl were detected in 13 individuals with a history of chyluria, including 3 with TG levels ranging from 233 to 1955 mg/dl and cholesterol levels of 6-35 mg/dl. Three patients who had a filarial history but without chyluria were also found to have urinary TGs (13-15 mg/dl) without detectable cholesterol. Neither TGs nor cholesterol were detected in the urine of normal individuals. Fluctuations in postprandial urine lipid contents were measured by time course determinations of urinary TG and cholesterol in 17 patients with filariasis and a history of chyluria, 16 patients with filariasis and hydrocele and 16 normal individuals. The level of urine lipid excretion was found to increase within 1-4 h postprandially, with urinary TG levels ranging between 7.8 and 1284 mg/h in eight patients and urinary cholesterol levels between 1.2 and 138 mg/h in seven patients with a history of chyluria. To evaluate the origin of the urine lipids in hematochyluria, fish oil containing 360 mg eicosapentaenoic acid (EPA) and 240 mg docosahexaenoic acid (DHA) was prescribed to a patient with hematochyluria. The excretion of EPA and DHA in urine was increased postprandially in the patient, similar to the elevation of urinary TG and cholesterol. The profile of fatty acids from urine samples showed it was of dietary origin. Our results suggest that postprandial urine lipids, especially TG, might be used as markers for the clinical evaluation of chyluria.

Adult↗

PubMed1997

Lipoblastomatosis in a newborn: case report.

A male newborn had a well-circumscribed, solid mass on the right anterior chest wall at birth. Computed tomography disclosed an infiltrating soft-tissue mass over the right 6th to 9th ribs near the costochondral junction. Surgical excision was done at the age of 5 days. Pathologic examination showed lipoblastomatosis.

Humans↗

PubMed1997

In vitro hatched oncospheres of Asian Taenia from Korea and Taiwan develop into cysticerci in the peritoneal cavity of female scid (severe combined immunodeficiency) mice.

In vitro hatched (but not activated) oncospheres of Asian Taenia obtained in Korea and Taiwan, prepared by the sodium hypochlorite method, rinsed with sterile PBS several times and adjusted to 5 x 10(4)/0.5 ml PBS, were injected intraperitoneally or subcutaneously into male or female scid mice of 3 different strains. When these scid mice were sacrificed 4 months later, the females harboured fully developed cysticerci either in the peritoneal cavity or under the back skin, whereas males did not. All cysticerci from the peritoneal cavity were easily recovered by rinsing the abdomen with PBS. Although most cysticerci recovered from pig liver usually become calcified within 1-2 months, in female scid mice they all increased in size and were viable. Intraperitoneal (i.p.) injection of in vitro hatched oncospheres is recommended for easier recovery of Asian Taenia metacestodes in laboratory animals.

Animals↗

PubMed1997

Analysis of the effect of pattern adaptation on pattern pedestal effects: a two-process model.

Pattern contrast thresholds for vertical Gabor patterns were measured on pattern pedestals that were vertical or horizontal. Contrast of the pedestal was varied to measure the function relating target contrast threshold to pedestal contrast (TvC function). TvC functions were measured without an adaptor and after adaptation to vertical, horizontal and plaid patterns. For a pedestal with the same orientation as the target, the vertical and plaid adapters increased thresholds at low pedestal contrasts, but not high. For the pedestal orthogonal to the target, the same two adaptors increased thresholds over the whole range of pedestal contrasts. These asymmetric effects are described by a model of adaptation and masking derived from a model of masking (Foley, 1994a) by allowing two parameters to vary with the adapt state; one of them is an additive parameter in the denominator of the response function, which can be interpreted as adaptor-produced divisive inhibition that persists after adaptor offset; the other is the sensitivity to pedestal-produced divisive inhibition, which is changed by adaptation for the pedestal orthogonal to the target. Other models do not account for both effects.

Adaptation, Physiological↗

PubMed1997

Alcohol problems and long-term psychosocial outcome in Chinese patients with bipolar disorder.

BACKGROUND: A high comorbidity of alcohol use disorders among Western bipolar patients is recognized and worsens the outcome of bipolar illness. In view of lower prevalence of alcohol use disorders in some Asian groups, we attempted to investigate the alcohol problems among Chinese bipolar patients in Taiwan. METHODS: The clinical data of bipolar patients (DSM-III-R) having been followed-up naturally for at least 15 years were obtained by a combination of chart reviews and interviews with patients and family members. RESULTS: Based on a retrospective chart review of 158 patients, 8.2% of them were found to have alcohol problems. The lifetime prevalence of alcohol abuse was 6.9%, and of alcohol dependence 3.0% among 101 subjects accepting interview. According to the Global Assessment of Functioning Scale (APA, 1994) nearly one-third of them were clearly dysfunctional. LIMITATION: As subjects had a greater mean age, the age-related effects probably worsened the psychosocial outcome and reduced the incidence of new substance abuse. CONCLUSION: Chinese bipolar patients, despite a lower comorbidity of alcohol use disorders, do not have a more favorable long-term psychosocial outcome (marriage, work, and social adjustment) than Western patients.

Adult↗

PubMed1997

Nucleotide sequence and transcriptional analysis of a portion of the bovine herpesvirus genome encoding genes homologous to HSV-1, UL25, UL26 and UL26.5.

We determined the nucleotide sequence of a 3,811 base pair (bp) region of the bovine herpesvirus type-1 (BHV-1) HindIII-A fragment covering map units 0.429-0.456, which contained the HSV-1 homologues of the UL25, UL26 and UL26.5 genes. Sequence overlap was verified with previously published BHV-1 sequences, resulting in contiguous sequence spanning from UL24 to UL27 (encoding glycoprotein B). We found that the UL25 open reading frame (ORF) overlapped that of UL24 by 16 nucleotides, an unexpected feature based on previous herpesvirus sequences. We previously showed that the BHV-1 UL26 and UL26.5 genes encoded proteins that functioned in proteinase and scaffolding activity during capsid assembly, similar to the homologues in herpes simplex virus type-1. Northern blotting was used to map the four major transcripts from this region. As expected from the ORF analysis, the BHV-1 UL25 transcript initiated within the UL24 ORF. The BHV-1 UL24, UL25, UL26 and UL26.5 transcripts all terminated at a common 3'-polyadenylation site and varied significantly in their relative abundance.

Amino Acid Sequence↗

PubMed1997

Effects of long-term administration of octreotide on sodium retention and atrial natriuretic peptide in carbon tetrachloride-induced cirrhotic rats.

BACKGROUND/AIMS: To realize the roles of peripheral vasodilatation and atrial natriuretic peptide in the formation of cirrhotic ascites, the effects of long-term administration of octreotide on carbon tetrachloride-induced cirrhotic rats were evaluated. METHODS: Urine sodium excretion, hemodynamics, plasma atrial natriuretic peptide levels, renin activities and aldosterone concentrations were compared between cirrhotic and control rats (protocol 1); and between octreotide- (65 micrograms/kg, twice daily for 10 days, subcutaneously) and placebo-treated (5% dextrose) cirrhotic rats (protocol 2). In an in vitro experiment, right atrial tissue of cirrhotic rats was incubated with different concentrations of octreotide to evaluate the release of atrial natriuretic peptide (protocol 3). RESULTS: Cirrhotic rats had significantly lower urine sodium excretion and systemic vascular resistance, and significantly higher plasma atrial natriuretic peptide levels, renin activities and aldosterone concentrations than control rats. Compared with placebo-treated cirrhotic rats, octreotide caused increased urine sodium excretion (-10 +/- 4% vs. 13 +/- 8% from baseline values, p < 0.05) and systemic vascular resistance (2.6 +/- 0.1 vs. 3.3 +/- 0.3 mmHg.min.100 g.ml-1, p < 0.05); and decreased plasma atrial natriuretic peptide levels (166.7 +/- 24.8 vs. 234.0 +/- 19.2 pg/ ml, p < 0.05), renin activities (2.45 +/- 0.49 vs. 4.36 +/- 0.53 ng.ml-1.h-1, p < 0.01) and aldosterone concentrations (290.2 +/- 40.0 vs. 483.3 +/- 82.6 pg/ml, p < 0.05). In the in vitro experiment, right atrial release of atrial natriuretic peptide of cirrhotic rats was not significantly changed when incubated with different concentrations of octreotide. CONCLUSIONS: Octreotide ameliorates renal sodium retention and suppresses plasma levels of atrial natriuretic peptide of ascitic cirrhotic rats with a novel mechanism via, at least partly, the modification of peripheral vascular resistance.

Animals↗

PubMed1997

Blood levels of reduced haloperidol versus clinical efficacy and extrapyramidal side effects of haloperidol.

1. The studies of relationships between blood levels of reduced haloperidol HL (RH) and clinical efficacy in haloperidol (HL)-treated patients have yielded variable results. On the other hand, the contribution of RH upon HL's extrapyramidal side effects (EPS) had been suggested in animal models as well as in preliminary clinical studies with limited subjects. 2. This study explored the relationships between blood drug levels and clinical effects and EPS of HL in 48 Chinese acutely exacerbated schizophrenic inpatients. After a single-blind placebo period of one week, the patients were treated with a fixed dose 10 mg of HL for two weeks. Steady-state levels of HL and RH in plasma (n = 48) and in red blood cells (RBC) (n = 37) were measured by high performance liquid chromatography. 3. The mean RH/HL ratio in RBC in the Chinese (0.55) is lower than that in non-Chinese patients as reported in the literature (> 2), so is the RH/HL ratios in plasma. 4. No significant relationship emerged between percent improvement in BPRS total score and any of drug indices (HL, RH, sum of two compounds (HL+RH), and RH/HL ratio) in plasma and in RBC. Furthermore, the responders did not differ significantly from the nonresponders in each drug index. 5. Plasma RH levels were significantly higher in 30 patients experiencing EPS compared with the other 18 patients (mean 2.14 +/- 1.71 (S.D.) ng/ml vs. 1.38 +/- 0.37 ng/ml, p < 0.05). No significant differences in other drug indices were noted between subjects with or without EPS.

Adolescent↗