Biomedical subjects

C R Yang

Publications and source records attributed to C R Yang.

At least 127 records · Page 7Linked to original sources

PubMed1991

Hormonal screening in impotent patients.

Of a total 260 impotent patients entered in a hormonal study, serum testosterone, prolactin and hormonal abnormalities were detected in 30 (11.5%) patients (18 with hypotestosteronemia and 12 with hyperprolactinemia). The 18 cases of hypotestosteronemia included: 8 cases of hypergonadotropic hypogonadism due to klinefelter's syndrome (1), orchitis (2), chronic alcoholism (1), and idiopathic primary gonadal failure (4) and 10 cases etiologically unknown hypotestosteronemia. Nine of the 18 patients also displayed other organic etiologies (6 vasculogenic and 3 diabetic impotence). After replacement of testosterone propionate by intramuscular injection, the improvement in impotence was significant in 12 patients (excellent in 1, good in 11) and insignificant in 6 (poor in 3, no response in 3). The positive response rate was 89% (8/9) for sole hypotestosteronemia and 44% (4/9) for hypotestosteronemia accompanied by other organic causes of impotence. In the 12 patients with hyperprolactinemia, 4 had prolactinomas. Of these, 3 were treated by surgery and 1 with bromocriptine. Three (excellent in 2, good in 1) of the 4 showed a positive erection response afterwards, but the other patient's response was poor because of postoperative residual tumor. Two patients had drug-induced hyperprolactinemia (haloperidol and methyldopa) and for one, impotence was improved after withdrawal of haloperidol. However, the other responded poorly due to vasculogenic impotence. Six patients with hyperprolactinemia of unknown etiology (2 accompanied by vasculogenic impotence, 2 by diabetic impotence and 2 by sole hyperprolactinemia) were treated with bromocriptine and improvement was noted in 3. The positive response rate was 71.4% (5/7) for sole hyperprolactinemia and 40% (2/5) for hyperprolactinemia accompanied by other organic causes of impotence. Good results were achieved in prolactinoma, sole hyperprolactinemia and hypotestosteronemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1991

Glomerular diseases in human renal allograft.

A total of 64 renal graft biopsies performed on 44 transplant patients from among 116 transplants (12 from living donors, 104 from cadavers) were analyzed during the period from July 1983 to December 1990. The frequency of allograft glomerular disease was 22.7% (10/44). Membranous glomerulonephritis (MGN) was detected in five patients; focal segmental glomerulosclerosis (FSGS), in two; transplant glomerulopathy, in two; and IgA nephropathy, in one. Nephrotic syndrome occurred in nine of the ten patients. Progressive deterioration of graft function developed in four patients associated with chronic rejection, and two of them later lost the graft. The remaining six patients had no chronic rejection and retained a stable renal condition with one exception, a patient who suffered from acute total occlusion of the right internal iliac artery and who eventually lost the graft. It is concluded that MGN is the most common allograft glomerular disease, but the outcome of the graft is probably related to the coexistent chronic rejection.

Adult↗

PubMed1991

[Separation and identification of main medicinal saponin components from mass cell cultures of Panax notoginseng (Burk) F. H. Chen].

Five main saponins were separated from the cell cultures of Panax notoginseng (Burk) F. H. Chen. They were sanchinoside Rb1, Re, R1, Rg1 and Rh1 identified by TLC, HPLC, IR, M. P., 13CNMR and EI-MS. Saponin components of the cell cultures were almost the same as those of the cultivated plants. But the content of saponins was different between the cell cultures and the cultivated plants. Saponin extraction and separation procedure suitable for the cell cultures has to be different from that for the cultivated plants.

Medicine, Chinese Traditional↗

PubMed1991

Renal oncocytoma: report of two cases and review of literature.

Renal oncocytoma was previously reported as a benign tumor arising from proximal tubular epithelial cells, but malignant potential with local invasion and distant metastasis has been emphasized in recent literature. It is difficult to differentiate it from renal cell carcinoma, but four typical angiographical signs may give suggestive evidence of the tumor. Radical nephrectomy with lymphadenectomy may be the choice of treatment, except in solitary kidney, bilateral tumors, or contralateral renal cell carcinoma. We report two female patients who were found incidentally to have renal tumors during a survey of right upper quadrant pain. Typical angiographic signs were found incidentally to have renal tumors during a survey of right upper quadrant pain. Typical angiographic signs were found in one patient, and atypical signs in the other. Three and eight years after radical nephrectomy with para-aortic lymphadenectomy, there has been no evidence of local recurrence or distant metastasis.

Adenoma↗

PubMed1991

Primary retroperitoneal sarcomas--a report of 16 cases.

From November 1982 to August 1990, 16 patients with primary retroperitoneal sarcoma were treated in our hospital. The most frequent types of tumor were liposarcoma (6), malignant fibrous histiocytoma (3). The commonest clinical findings were palpable abdominal mass (14/16). In management of these patients; nine patients underwent complete resection of the tumor; three patients underwent partial resection of the tumor and four patients underwent biopsy only. The histology of tumor appeared to have prognostic significance. Patients suffering from liposarcoma (3/5) and malignant fibrous histiocytoma (1/2) survived the longest. With a mean follow up of 25.0 months, the three year overall survival rate of complete resection group was 50 per cent. No patients with partial resection and biopsy only group survive three years and the total three-years overall survival rate was 29%. The mean survival for patients after adjuvant chemotherapy and/or radiotherapy was similar to that after a radical operation alone. The prognosis of primary retroperitoneal sarcoma is grave and complete resection of the tumor as initial treatment seems to provide the only chance of cure for these patients.

Adolescent↗

PubMed1990

Dopaminergic modulation of cholinergic responses in rat medial prefrontal cortex: an electrophysiological study.

The neuromodulatory action of dopamine (DA) on acetylcholine (ACh)-evoked responses of prefrontal cortex (PFC) neurones were investigated electrophysiologically in rats anaesthetised with a combination of urethane and ketamine. Iontophoretic application of ACh-excited prefrontal cortex neurones. Concurrent application of DA (5-15 nA) resulted in complex changes in the ACh-evoked responses: (1) DA depressed spontaneous background discharges (designated as noise) proportionally more than the ACh-evoked discharges (designated as input signals), thus yielding an enhanced signal/noise ratio. This increase in signal/noise ratio by dopamine was reversed by iontophoretic application of the Da D2 antagonist sulpiride (20-50 nA). Nevertheless, iontophoretic application of D2 agonist quinpirole (5-35 nA) enhanced the ACh-evoked response, but was accompanied by some increase in spontaneous discharge, thus yielding no change in the signal/noise ratio. (2) DA also increased the signal/noise ratio by inducing a net increase of the ACh-evoked response but simultaneously suppressed the spontaneous activity of PFC neurones. This effect was more prominent following blockade of D1 receptors by SCH23390 (6 mg/kg, i.p.), suggesting that D1 receptors may normally inhibit D2 receptor function in the PFC. In addition, endogenous DA in the PFC did not play a significant part in modifying the ACh-evoked responses since the modulation of ACh-evoked response by DA or its D1 and D2 agonists was similar in both saline control and alpha-methyl-p-tyrosine-pretreated rats. (3) When ejected with larger iontophoretic current (16-35 nA), DA suppressed both the ACh-evoked and spontaneous discharge and this effect was mimicked by D1 agonist SKF38393 (5-15 nA). Taken together, these results suggest that complex dopaminergic modulation of the cholinergic responses of prefrontal cortex neurones are mediated by D1 and D2 receptors. This DA action may have a functional role in the cognitive-integrative processes occurring in the prefrontal cortex.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗

PubMed1990

Metabolic evaluation of urolithiasis.

After detailed instruction, 62 patients with urolithiasis treated at Taichung Veterans General Hospital entered this program, which ran from September 1987 to November 1988. Based on Pak's classification, there were 13 cases (21.0%) of absorptive hypercalciuria, type I (AH-I); 12 cases (19.4%) of absorptive hypercalciuria, type II (AH-II); 16 cases (25.8%) of renal hypercalciuria (RH); 3 cases (4.8%) of hyperuricosuric calcium urolithiasis (HUCU); 11 cases (17.7%) of hypocitraturia (Hypocit); 3 cases (4.8%) of hyperoxluria (HO); one case (1.6%) of primary hyperparathyroidism (PHPT) and one case (1.6%) of infectious lithiasis. Two cases (3.2%) with no metabolic abnormalities were found. Hypocitraturia, HUCU, and HO can be the primary abnormal findings, but more often coexist with various forms of hypercalciuria as a second factor. If the coexistence is considered, hypocitraturia (33 cases, 53.2%) and HUCU (24 cases, 38.7%) were the most prevalent categories. Meanwhile, 24 cases (38.7%) had only one physiological derangement, 25 cases (40.3%) had two derangements, and 13 cases (21.0%) had three. This study indicates that metabolic evaluation can elucidate the physiological derangements of urolithiasis, so that further medical treatment can be administered selectively.

Adult↗

PubMed1990

Evaluation of vasculogenic impotence using dynamic penile washout test.

Two control volunteers and 8 impotent patients entered this study for evaluation of arterial function and venous competence of the corpus cavernosum. The skin and corporeal xenon-133 (Xe-133) penile washout tests were conducted on each person before and 5 and 60 minutes after an intracavernous injection of prostaglandin E1. The half-time clearance (T 1/2) and blood flow (Q) were used for evaluation. The parameters of the skin washout test obtained from impotent patients changed from T 1/2 = 14.3 +/- 6.2 minutes, Q = 3.75 +/- 2.56 ml/100g tissue/minute preinjection to T 1/2 = 5.23 +/- 1.78, Q = 9.96 +/- 2.69 at 5 minutes post-injection and T 1/2 = 3.89 +/- 0.86, Q = 12.9 +/- 3.0 at 60 minutes post-injection, p less than 0.01; while the corporeal washout test changed from T 1/2 = 84.6 +/- 107.1 minutes, Q = 2.91 +/- 3.17 ml/100g tissue/minute to T 1/2 = 41.2 +/- 99.6, Q = 10.6 +/- 9.7 and T 1/2 = 13.9 +/- 16.2, Q = 7.78 +/- 6.35, p less than 0.05, respectively. The flow ratio (post-injection/pre-injection) was 1.01-6.04 at 5 minutes and 1.39-8.01 at 60 minutes later in the skin washout test, and 1.07-72.2 at 5 minutes and 0.60-45.7 at 60 minutes in the corporeal washout test. However, the individual variations were considerable. This study suggests that the Xe-133 penile washout test after an intracavernous injection may help in demonstrating the hemodynamics of the cavernosal arteries and dorsal arteries, and in evaluating the severity of penile vascular impairment. Moreover, the flow ratio may reflect vascular compliance; the higher the ratio, the better the compliance.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1990

Diarrhoea surveillance in children aged under 5 years in a rural area of Hebei Province, China.

A surveillance of diarrhoeal diseases in children aged under five years was carried out from March 1986 to February 1987 in a rural area of Hebei Province, China. Using a cluster sampling method, 270 study children were selected from 30 villages to represent a population of 105,405. Parents noted episodes of diarrhoea in children on a calender using a given definition of diarrhoea. The findings were verified by trained village doctors and were recorded monthly in the county Health and Anti-epidemic Stations. Stools of diarrhoea-affected children were examined to detect causal agents of diarrhoea, once in each of four seasons of the year. Of the 270 children, 218 (80.74%) suffered from one or more than one attacks of diarrhoea with a 95% confidence interval between 75.94% and 85.54%. There was no death due to diarrhoea. The diarrhoeal incidence in children of 3-4-year age group was significantly less than that in the children of less than 3 years (p less than 0.05). In the children with diarrhoea, the number of mean episodes was 3.15 per child/year, and the total mean course of suffering was 14 days per child/year. The ratio of diarrhoeal episodes in spring, summer, autumn, and winter was about 2.5:5:2:1. July was the month of highest occurrence of diarrhoea (146; 21.28% of all episodes). The epidemiological parameters of the disease declined with the growing age of the children, and there was no gender-specific preponderance in the number of episodes. During the whole year, 21.7% of the diarrhoeal episodes were due to bacterial pathogens, 4% of the episodes were due to rotavirus, and 3.65% episodes were associated with the detection of Trichomonas hominis.(ABSTRACT TRUNCATED AT 250 WORDS)

Child, Preschool↗

PubMed1990

[Steroidal saponins from Asparagus filicinus].

Three new steroidal saponins, aspafilioside A, B and C together with a known saponin 22-methoxy ASP-IV and beta-ecdysone were isolated from the root of Asparagus filicinus Buch.-Ham. (Chinese name as xiao-bai-bu), a folk medicine of the minorities in Yunnan Province, China, used for the treatment of bronchitis, pneumonitis and cough. Their structures were established as sarsasa pogenin-3-O-beta-D-xy lopyranosyl (1----4)-beta-D-glucopyranoside (I), sarsasapogenin-3-O-beta-D-xylopyranosyl (1----4) [alpha-L-arabinopyranosyl (1----6)]-beta-D-glucopyranoside (II) and (25S)-5 beta-furost-3 beta, 22, 26-triol-3-O-beta-D-xylopyranosyl (1----4) [alpha-L-arabinopyranosyl(1----6)]-beta-D-glucopyranoside-26-O-bet a-D- glucopyranoside (III) by spectral and chemical methods.

Drugs, Chinese Herbal↗

PubMed1989

The role of the hippocampal-nucleus accumbens pathway in radial-arm maze performance.

The role of the glutamatergic hippocampal-nucleus accumbens pathway in relaying hippocampal information via the nucleus accumbens to the motor system was investigated behaviorally using the radial-arm maze paradigm in rats. Bilateral injections of kynurenic acid, a glutamate antagonist, into the nucleus accumbens increased the latency to initiate movement during performance of an 8-arm radial maze with all arms baited and with 4 arms baited. Injections of kynurenic acid did not change the number of visits to previously visited arms (i.e. working memory errors) on both versions of the 8-arm radial maze. However, on the 8-arm radial maze with 4 arms baited, injections increased the number of visits to unbaited arms (i.e. reference memory errors). Similar injections were made in rats with ibotenic acid lesions of the prefrontal cortex in order to eliminate the glutamatergic prefrontal cortex-nucleus accumbens pathway so as to investigate the glutamatergic hippocampal-nucleus accumbens pathway. These rats displayed similar deficits on the radial-arm maze as non-lesioned rats (i.e. enhanced latency to initiate movement and reference memory errors). These findings suggest that the glutamatergic hippocampal-accumbens pathway plays a role in radial-arm maze performance by transferring information required for performing a radial-arm maze to the motor system.

Animals↗

PubMed1989

A comparison of the effects of electrical stimulation of the amygdala and hippocampus on subpallidal output neurons to the pedunculopontine nucleus.

Recordings were made of the electrical activity of neurons in the subpallidal area of urethane-anesthetized rats. Output neurons from the subpallidal area to the pedunculopontine nucleus were identified by antidromic activation. The inputs to subpallidal neurons to single-pulse stimulation of the amygdala and hippocampus were investigated. More than two-thirds of the subpallidal neurons antidromically activated by pedunculopontine stimulation were inhibited by hippocampal stimulation and activated by amygdala stimulation. Subpallidal neurons not antidromically activated by pedunculopontine stimulation also responded to stimulation of the amygdala and hippocampus but no differential effects were observed. The relation of these findings to limbic influences on locomotor activity is discussed.

Action Potentials↗

PubMed1989

Ventral pallidal neuronal responses to dopamine receptor stimulation in the nucleus accumbens.

The possible role of ventral pallidum (VP) in expressing dopaminergic actions in the nucleus accumbens was studied electrophysiologically using extracellular single unit recording and iontophoretic techniques in urethane-anaesthetized rats. Microinjections of dopamine (130 mM, 5-10 micrograms/0.2-0.4 microliters) into the nucleus accumbens resulted in a gradual, but prolonged, increase in the firing rate of VP neurones. Injections of the D1 agonist SKF38393 (34 mM, 2 micrograms/0.2 microliters), followed by the D2 agonist quinpirole (40 mM, 2 micrograms/0.2 microliters) into the accumbens, but not in the reverse order, resulted in a similar increase in the activity of VP neurones, mimicking the dopaminergic effect. Injections of either the D1 or the D2 agonist alone into the accumbens, however, produced no significant changes. Furthermore, iontophoretic application of picrotoxin, a gamma-aminobutyric acid (GABA) antagonist, or naloxone, an opiate (including enkephalin) antagonist on the same VP neurone which responded to accumbens dopamine injection also increase its spontaneous firing rate. Thus, pre-activation of D1 receptors in the accumbens was essential for the subsequent physiological expression of D2 receptors in inducing an increase in the firing rate of VP neurones. Dopamine in the accumbens may suppress the tonic inhibitory GABAergic and enkephalinergic outputs to the VP, resulting in an increase in firing rate of VP neurones. Since previous behavioural studies have shown that dopaminergic stimulation in the accumbens increases locomotor activity, the increased firing rate of ventral pallidal neurones may be expressing the postsynaptic actions of dopamine receptor stimulations in the accumbens as initiation of locomotor activity.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗

PubMed1989

Impotence evaluated by the use of prostaglandin E1.

We screened 80 patients at our hospital for the differential diagnosis of impotence using intracavernous injection of prostaglandin E1 (20 micrograms). The rate of positive response was 78.8 per cent (63 patients). Neither systemic reactions nor priapism occurred. However, a considerable incidence (23.8 per cent, 19 of 80 patients) of tolerable injection pain was encountered. The 133xenon penile washout study was conducted routinely in impotent men for hemodynamic evaluation of penile vascularity. In 80 patients a positive correlation between the response of intracavernous prostaglandin E1 injection and the result of the washout study was found (r equals 0.381, p less than 0.0002). We selected 14 subjects randomly to receive additional intravenous infusions of prostaglandin E1 (6 ampules, 120 micrograms total) for 3 days, after which another 133xenon washout study was done. The washout studies before and after intravenous prostaglandin E1 infusion were compared, and 10 patients (71.4 per cent) appeared to obtain improvement in half-time clearance and penile blood flow. However, only 3 patients noticed improvement subjectively. We suggest that prostaglandin E1 could be a desirable alternative for the diagnosis and treatment of impotence.

Adult↗

PubMed1989

Characterization of the domain structure of chick c-erbA by deletion mutation: in vitro translation and cell transfection studies.

Chicken c-erbA (Ck-c-erbA) cDNA (1250 base pairs), a cellular homologue of the avian erythroblastosis virus v-erbA gene, encodes a 408 amino acid protein which binds L-T3 and its analogs with affinities similar to that of endogenous thyroid hormone nuclear receptors. By analogy with steroid receptors, Ck-c-erbA(Met1-Val408) contains an A and B domain (amino acids 1-50); a putative DNA binding C domain (amino acids 51-118); a hydrophilic D domain (amino acids 119-189); and a putative ligand binding E domain (amino acids 187-408). To further characterize the ligand binding region of Ck-c-erbA, two deletion mutations were constructed: Ck-c-erbA(Met120-Val408) which encodes a 289 amino acid protein lacking regions A, B, and C; and Ck-c-erbA-(Met199-Val408) which encodes a 210 amino acid protein lacking regions A, B, C, D, and the first 12 amino acids of the E region. The in vitro translation products ([35S]methionine) of cDNA transcripts of a human placental c-erbA, Ck-c-erbA (Met1-Val408), and Ck-c-erbA(Met120-Val408) efficiently bind L-[125I]T3, whereas Ck-c-erbA(Met199-Val408) does not bind L-[125I]T3. In frame substitution of the last 14 C-terminal amino acids of Ck-c-erbA(Met1-Val408) for the last 7 C-terminal amino acids of v-erbA reduces but does not eliminate L[125I]T3 binding. These results indicate that a broad region of the E domain is important for ligand binding.(ABSTRACT TRUNCATED AT 250 WORDS)

Affinity Labels↗

PubMed1989

A domain containing leucine-zipper-like motifs mediate novel in vivo interactions between the thyroid hormone and retinoic acid receptors.

The thyroid hormones and retinoic acid are potent modulators of differentiation, development, and gene expression. The transcriptional activities of these ligands are mediated by closely related nuclear receptors which bind and activate identical hormone responsive DNA elements. We noticed that a region within the ligand binding or E domain is well conserved between receptors for these hormones. This region contains hydrophobic heptad repeats that are structurally similar to the leucine-zipper dimerization domain. To study the function of this conserved domain, we examined the transcriptional responses of thyroid hormone receptor/c-erbA deletion mutants which lacked the heptad repeats. We previously reported that the chick c-erbA-alpha possesses hormone-independent (constitutive) activity in cells which express endogenous rat thyroid hormone receptor. We now demonstrate that this activity is abolished upon deletion of the conserved heptad repeats. This suggests that the heptad repeats mediate in vivo interactions between chick c-erbA and rat thyroid hormone receptors. To further test this hypothesis deletion mutants of chick c-erbA were constructed which contained all eight heptad repeats but which lacked the zinc-finger DNA binding domain. Although these mutants are transcriptionally inactive, they act in a dominant-negative fashion to block trans-activation by both the chick c-erbA-alpha and the endogenous thyroid hormone and retinoic acid receptors. We suggest that the heptad repeats mediate the formation of inactive mutant/wild-type hetero-dimers. Dimer formation suggests a mechanism to account for the dominant-negative phenotypes displayed by nonhormone binding variants of c-erbA, the proto-oncoprotein v-erbA and patients with the generalized thyroid hormone resistance syndrome.

Amino Acid Sequence↗

PubMed1989

[Studies on saponins from the leaves of Panax japonicus var. bipinnatifidus(Seem.)Wu et Feng].

Two new saponins, bipinnatifidusoside F1(XII) and F2(XIII), were isolated along with eleven known saponins from the dried leaves of Panax japonicus var.bipinnatifidus(Seem.)Wu et Feng collected in the Range of Qinling Mountains in China. By spectrometric analysis(FAB-MS,1H and 13CNMR,1H-1H COSY), their structures were elucidated as dammar-25(26)-ene-3 beta, 12 beta, 20(S),24 zeta-tetraol-(20-O-beta-D-glucopyranosyl)-3-O- beta-D-glucopyranosyl(1-2)-beta-D-glucopyranoside (bipinnatifidusodie F1) and dammar-22(23) ene-3 beta, 12 beta, 20(S),24 zeta-tetraol-(20-O-beta-D-glucopyranosyl)-3-O-beta- D-glucopyranosyl(1-2)-beta-D-glucopyranoside (bipinnatifidusoside F2), respectively. The known saponins were identified as ginsenoside F1,F2,F3,Rg2,Re,Rd,Rb1,Rb3, 24(S)-pseudoginsenoside F11, panasenoside and majoroside F1. Compared with bipinnatifidusoside F2, majoroside F3 was corrected as dammar-22(23)-ene-3 beta, 12 beta,20(S),24 zeta-tetraol-(20-O-beta-D- glucopyranosyl)-3-O-beta-D-glucopyranoside.

Chemical Phenomena↗

PubMed1989

[Further study on dammarane saponins of leaves of Panax japonicus var. major collected in Quinling Mountains China].

In continuation of our studies on the leaves of Panax japonicus var. major (Burk.) Wu et Feng, two new dammarane saponins are isolated. By means of FAB-MS and 13CNMR, their structures were elucidated as dammar-22(23)-ene-3 beta, 6 alpha, 12 beta, 20(S), 24 section-pentaol- (20-O-beta-D-glucopyranosyl)-6-O-alpha-L-rhamnopyranosyl (1-2)-beta-D- glucopyranoside (majorosids F5) and dammar-23(24)-ene-3 beta, 6 alpha, 12 beta, 20(S), 25-pentaol-(20-O-beta-D- glucopyranosyl)-6-O-alpha-L-rhamnopyranosyl(1-2)-beta-D-glucopyranoside (majoroside F6).

Chemical Phenomena↗