Search PubMed⌕ Search

Biomedical subjects

G Zhao

Publications and source records attributed to G Zhao.

At least 289 records · Page 16Linked to original sources
PubMed1992

[Cardiovascular responses to microinjection of atrial natriuretic peptide into ventrolateral medulla of rat].

Application of atrial natriuretic peptides (alpha-ANP and AP III) to glutamate sensitive area of ventrolateral medulla produced a dose-dependent decrease in MAP and HR in anesthetized rats. Lower dosage of AP III induced hypotension without bradycardia, whereas the higher dosage of AP III decreased both blood pressure and heart rate. The results suggested that ANP may inhibit the medullary sympathetic center.

Animals↗
PubMed1992

Virus infection and hand papular dermatoses in young children.

Four strains of enterovirus and 1 strain of adenovirus were isolated from stool and pharyngeal swabs by inoculation into primary human embryonic kidney cell culture in 25 cases of dorsum manus infantile papular dermatitis. Two strains of Coxsackie A-9 virus and 1 strain of Echovirus-25 were identified. With the isolated virus as antigen, a matched pair study by sera antibody test was carried out in 43 children with papular dermatitis and 40 normal individuals as controls. In 26 cases of Coxsackie A-9 virus positive papular dermatitis, a 4-fold rise (> 1:1.6) in the relative serum antibody was observed in 80.77%, while no high levels were observed in patients with Echovirus-25 and adenovirus dermatitis (< 1:16). The authors can reasonably conclude that epidemic Coxsackie A-9 virus infection is obviously related to infantile papular dermatitis and is probably the main cause of the disease.

Antibodies, Viral↗
PubMed1992

[HPLC analysis of the active ingredients of Forsythia suspensa].

Forsythia suspensa is a widely used traditional Chinese herb. Because of the need to evaluate its quality, a HPLC method was developed to analyze the active ingredients in its fruits and leaves. One g of powdered plant material was cold macerated over-night with 10 ml of methanol added then supersonic extracted for 20 min. Four ml of the extract were mixed with 1 ml of water, centrifuged (400 x g, 15 min), and then analyzed by HPLC with a Nucleosil C--18 column. The mobile phase for gradient elusion consisted of MeOH(containing 1% tetrahydrofuran) and H2O (containing 0.01 mol/L KH2PO4,pH 3.2) and monitored by UV absorption at 280 nm. The identity and purity of the peaks were checked by photodiode array detector and in comparison with standards. By this procedure, the active constituents caffeic acid, rutin, forsythoside A, forsythin, and forsythigenin were separated successfully, and the quantity of each compound was determined by peak area. Some fruit samples obtained from various sources and the leaf sample made as tea were analyzed by this method.

Caffeic Acids↗
PubMed1991

Preliminary result of mixed bacterial vaccine as adjuvant treatment of hepatocellular carcinoma.

Mixed bacterial vaccine (MBV) was employed in the multi-modality treatment of hepatocellular carcinoma (HCC) during 1985-1988. Thirty eight patients undergoing palliative resection and cisplatin therapy (Series 1) and 48 patients with unresectable HCC who received hepatic artery ligation + intraarterial cisplatin infusion + radiotherapy (Series 2) were randomized to receive MBV or not. In series 1, the 1- and 2-year survival rates of MBV group and control were 75% vs 58% (P = 0.19) and 45% vs 39% (P = 0.23). In series 2, the 1-, 2- and 3-year survival rates were 59%, 41% and 41% for MBV group and 39%, 25% and 20% for the control, respectively (P1 = 0.07, P2 = 0.09, P3 = 0.07). In addition, MBV improved the "second look" resection rate to 40% as compared to 17% in the control (P greater than 0.05). MBV could also prevent such immunosuppression as decrease of macrophage activity caused by radiotherapy. We consider MBV a potential nonspecific immunostimulant in the multimodality treatment of HCC.

Adult↗
PubMed1991

Cloning, sequencing, and expression of the P-protein gene (pheA) of Pseudomonas stutzeri in Escherichia coli: implications for evolutionary relationships in phenylalanine biosynthesis.

The pheA gene encoding the bifunctional P-protein (chorismate mutase:prephenate dehydratase) was cloned from Pseudomonas stutzeri and sequenced. This is the first gene of phenylalanine biosynthesis to be cloned and sequenced from Pseudomonas. The pheA gene was expressed in Escherichia coli, allowing complementation of an E. coli pheA auxotroph. The enzymic and physical properties of the P-protein from a recombinant E. coli auxotroph expressing the pheA gene were identical to those of the native enzyme from P. stutzeri. The nucleotide sequence of the P. stutzeri pheA gene was 1095 base pairs in length, predicting a 365-residue protein product with an Mr of 40,844. Codon usage in the P. stutzeri pheA gene was similar to that of Pseudomonas aeruginosa but unusual in that cytosine and guanine were used at nearly equal frequencies in the third codon position. The deduced P-protein product showed sequence homology with peptide sequences of the E. coli P-protein, the N-terminal portion of the E. coli T-protein (chorismate mutase:prephenate dehydrogenase), and the monofunctional prephenate dehydratases of Bacillus subtilis and Corynebacterium glutamicum. A narrow range of values (26-35%) for amino acid matches revealed by pairwise alignments of monofunctional and bifunctional proteins possessing activity for prephenate dehydratase suggests that extensive divergence has occurred between even the nearest phylogenetic lineages.

Amino Acid Sequence↗
PubMed1991

[Inherited metabolic aberration of phenylalanine in the family members of patients with essential hypertension and stroke].

L-2H-Leu, L-2H-Val, L-2H-Ile, L-2H-Phe, 14N-Lys were chosen for comparing their metabolic kinetic variables among those with prominent genetic predisposition of essential hypertension (FH*, 10 subjects), of stroke (FS*, 12 subjects) and those without (F-, 12 subjects) groups by gas chromatography-mass spectrometry. Results showed that only the metabolic kinetics of phenylalanine was dearranged: (1) The plasma pools of FH* and FS* groups were enlarged; (2) The turnover rate constant between plasma pool and cell pool of FH* was constricted; (3) The cell pool of FH* was larger, while the turnover rate constant was smaller than that of FS* group. The aberration of phenylalanine metabolism in essential hypertension and stroke might relate with hyperfunction of sympathetic nervous activity genetically. These diseases possibly belong to the category related to the inherited amino-acid metabolic aberration.

Adult↗
PubMed1991

[The facilitating effect of atrial natriuretic factor on the carotid sinus baroreflex function].

Effects of atriopeptin II (APII) on the carotid sinus baroreflex in anesthetized rats and on the sinus nerve afferent activity in the anesthetized rabbits were investigated. The results were as follows: (1) By perfusing the isolated left carotid sinus with APII (1 microgram/ml) in anesthetized rats (n = 10), the threshold pressure (TP) of the carotid baroreflex did not show any change, while the equilibrium pressure (EP), the saturation pressure (SP) and the operating range (OR) were decreased from 101 +/- 2.8 to 95 +/- 2.0 mmHg (P less than 0.05), 202 +/- 5.2 to 168 +/- 6.1 mmHg (P less than 0.001) and 128 +/- 5.5 to 93 +/- 6.3 mmHg (P less than 0.001), respectively. The function curve of the baroreflex was shifted to the left and downward with a peak slope (PS) increased during perfusing with APII. In contrast, by perfusing the carotid sinus with sodium nitroprusside (NP, 0.5 micrograms/ml), TP and EP remained unchanged, whereas SP and OR were increased from 188 +/- 6.4 to 218 +/- 6.0 mmHg (n = 6, P less than 0.01) and from 107 +/- 6.9 to 132 +/- 7.6 mmHg (P less than 0.05), respectively. The function curve of the baroreflex and its PS were not affected by NP. The sinus nerve afferent activity was quite stable with the perfusion of carotid sinus at constant intrasinus pressure (ISP) in the rabbits (n = 6) and increased during the elevation of ISP.(ABSTRACT TRUNCATED AT 250 WORDS)

Afferent Pathways↗
PubMed1991

[Central cardiovascular and renal effects of atrial natriuretic peptide].

In 54 anesthetized rats, the changes in arterial blood pressure, heart rate and/or urine volume, urinary sodium excretion were observed following intracarotid, intrathecal and intracerebroventricular (ICV) injection of atrial natriuretic peptide (ANP). The effects of ANP on the central actions of angiotensin II (AG II) were also examined. The results were as follows: (1) In the cross-circulation preparation of rat head, MAP of the recipient was unchanged and that of the donor was decreased in response to the administration of alpha-hANP (15 micrograms/kg) into the carotid artery of the recipient. (2) By injecting AP III (5 micrograms/kg) intrathecally, MAP, HR and urine volume (V) of the rats (n = 7) showed no change. (3) The ICV injection of AP III (20 micrograms/kg) did not result in changes in MAP, HR, and urinary sodium excretion (UNaV), but there was a transient and significant increase in V. (4) ICV injection of AG II (1 microgram/kg) resulted in an increase of MAP by 1.3 +/- 0.17 kPa (10 +/- 1.3 mmHg, n = 10, P less than 0.001), V by 106% (n = 6, P less than 0.01) and UNaV by 642% (P less than 0.01). (5) ICV injection of AP III 2 min prior to the injection of AG II by the same route, the central hypertensive effect induced by AG II was not affected, while the increments in V and UNaV were decreased significantly (P less than 0.05). The results indicate that (1) ANP is incapable of penetrating the blood-brain barrier owing to its large molecular size and therefore, the central mechanism is not involved in the hypotensive effect induced by intravenous injection of ANF and (2) the central diuretic and natriuretic actions of AG II may be markedly inhibited by ICV injection of ANP, thus indicating the existence of some central antagonistic interactions between AG II and ANP.

Angiotensin II↗
PubMed1990

Long survival and prognostic factors in hepatocellular carcinoma.

We studied survival and prognostic factors in all cases of hepatocellular carcinoma seen at a Midwestern teaching hospital from 1947 through 1986. Of the 70 cases, 56 were diagnosed during life and 14 at autopsy. There were 47 males and 23 females with age at diagnosis ranging from 14 to 88. Median survival for the 56 patients diagnosed during life was 106 days. Only 11 patients lived longer than one year. Two patients were long survivors and presumed cured, one living 27 years after diagnosis and surgical treatment and the other 19 years. Cox regression model showed young age at diagnosis and low stage of disease at diagnosis to be significant predictors of long survival. White patients survived nearly twice as long as black patients but the difference was not significant. Gender and year of diagnosis did not appear to be important determinants of survival. Pathologic material was still available for one of the two long survivors and the histology was that of fibrolamellar carcinoma of young adults.

Age Factors↗
PubMed1990

[Calcium binding capacity of erythrocyte membrane in human hypertension and spontaneous hypertensive rats].

Several abnormalities of calcium transport have been reported in human essential hypertension (EHT) and spontaneous hypertensive rat (SHR). 45Ca binding capacity to erythrocyte membrane was measured in this study by filtration technique in the presence of 80 nmol/L Ca concentration. Results showed: (1) It was much lower in EHT (33 cases) than normal control (19 men) group, being 0.22 +/- 0.13 versus 0.35 +/- 0.18 nmol Ca2+/mg membrane protein (P less than 0.01), and correlated positively with blood pressure levels. (2) The average Ca binding capacity in young offsprings (15 adolescents) with both parents hypertensive was lower, but statistically not significant. (3) The average Ca binding capacity was also lower in SHR (9 rats) than control WKY (10 rats) group, being 0.83 +/- 0.27 versus 0.98 +/- 0.24 nmol Ca2+/mg membrane protein, yet statistically not significant. Therefore a decrement of membrane binding capacity might be related to the occurrence and maintenance of hypertension.

Adolescent↗
PubMed1990

[Effects of atrial natriuretic factor on regional blood flow in anesthetized rabbit].

The regional blood flow changes induced by intravenous injection of atriopeptin III (AP III) and the effects of intra-arterial injection of AP III on regional vascular resistance were investigated in 42 anesthetized rabbits. The results were as follows: (1) In anesthetized rabbits (n = 8), intravenous injection of AP III (30 micrograms/kg) resulted in a decrease in mean arterial pressure by 11.0 +/- 1.5 mmHg (M +/- SE, P less than 0.01), while the heart rate showed no change. (2) By using the isotopic biomicrosphere method, it was revealed that AP III increased the blood flow in renal cortex (P less than 0.05) and decreased the blood flow in renal medulla. However, the blood flow in brain, heart, intestine, and hindlimb muscle remained unchanged. (3) With the constant autoperfusion method, renal intra-arterial administration of AP III (0.8 micrograms/kg) decreased the mean renal perfusing pressure by 21.2 +/- 3.3 mmHg (n = 9, P less than 0.001). By injecting AP III into the femoral artery, the mean perfusing pressure of hindlimb lowered by 7.8 +/- 1.1 mmHg (n = 7, P less than 0.001). No change occurred in the perfusing pressure of mesenteric vascular bed following intraarterial injection of AP III. The results showed that AP III dilated the renal artery and thereby increased the renal blood flow. The vasodilating effect of AP III appeared to be more prominent in renal vascular bed than that in the other vascular beds. The increase in renal blood flow induced by AP III may be one of the mechanisms diuretic and natriuretic actions.

Animals↗
PubMed1990

[Effects of atrial natriuretic polypeptide on arterial pressure and renal sympathetic nerve activity in anesthetized rats].

The effects of atriopeptin III (AP III) on the arterial pressure (AP), heart rate (HR) and renal sympathetic nerve activity (RSNA) were investigated in anesthetized rats. The results were as follows: (1) In intact rats (n = 12), following intravenous injection of AP III (50 micrograms/kg), systolic arterial pressure (SAP) decreased by 23.0 +/- 1.66 mmHg (M +/- SE, P less than 0.001), HR decreased by 9 +/- 3.5 beats/min (P less than 0.05), and RSNA decreased by 4.89 +/- 2.95% (P greater than 0.05). After vagotomy, the decrease in SAP following iv. AP III showed no significant difference with that of intact rats. HR showed no change, while there was a small increase in RSNA (P greater than 0.05); (2) In the intact vagi but sinoaortic denervated rats (n = 7), intravenous AP III decreased SAP by 27.4 +/- 3.25 mmHg (P less than 0.001), HR by 13 +/- 3.1 beats/min (P less than 0.01), and RSNA by 11.67 +/- 1.95% (P less than 0.001). After vagotomy, the decrease in SAP following i.v. AP III was attenuated, HR showed no significant change, but there was a small but significant increase in RSNA (P less than 0.05); (3) Following intravenous injection of nitroprusside, SAP decreased significantly. Such a hypotensive effect was associated with an increase in RSNA in either the intact or the vagotomized rats. The results indicate that (1) the hypotensive effect of AP III was mediated partly by vagi; (2) in the sinoaortic denervated rats AP III could reflexly inhibit RSNA by activation of vagal afferent fibers.

Animals↗
PubMed1987

First report of an epidemic of diarrhoea in human neonates involving the new rotavirus and biological characteristics of the epidemic virus strain (KMB/R85).

An outbreak of diarrhoea in neonates occurred at the nurseries of the Department of Obstetrics of Zhao Tong Regional Hospital, Yunnan Province, from the middle of August to the end of November, 1985. Fifty-one percent of children were affected 2-8 days after birth. The clinical symptoms were mild; patients mainly had diarrhoea and did not vomit. Rotaviruses were detected in 66.7% by RNA PAGE and in 72.7% by EM. The virus strain designated as KMB/R85 had a typical morphology, which was indistinguishable from that of infantile rotaviruses by EM. The viral RNA genome was composed of 11 segments. The buoyant density in CsCl was 1.377 g/cm3. The KMB/R85 strain possessed a hemagglutinin for rhesus monkey erythrocytes. By ELISA, IEM, and HAI, it was found that KMB/R85 strain did not possess the common group antigen shared by group A rotaviruses and was antigenically similar to the Chinese adult diarrhoea rotavirus (serogroup B).

Centrifugation, Isopycnic↗