Search PubMed⌕ Search

Biomedical subjects

B L Zhang

Publications and source records attributed to B L Zhang.

At least 37 records · Page 2Linked to original sources
PubMed1996

Effect of nimodipine on infectious brain edema in rabbits.

AIM: To study the effect of nimodipine (Nim) on infectious brain edema (BE). METHODS: An infectious BE model was induced by injection of Bordetella pertussis suspension (BPS) into right internal carotid artery in rabbits. Eighteen rabbits were randomly divided into 3 groups (n = 6). Group BE: BPS (0.6 mL.kg-1) was given; group NS: normal saline was given as control; group Nim: 10 min after injection of BPS, Nim, 10 micrograms.kg-1, was injected i.v. as a bolus followed by continuous infusion of 0.75 microgram.kg-1.min-1. All the rabbits were kept under observation for 4 h. Evans blue staining was assessed; water, calcium, calmodulin (Cal), and sodium contents were determined in the right brain. RESULTS: Nim vs BE: water 82.2 +/- 1.0% vs 84.4 +/- 1.2 (P < 0.01); calcium 10.5 +/- 1.3 mmol.kg-1 dry tissue vs 17.5 +/- 1.4 (P < 0.01); Cal 15.9 +/- 1.8 mumol.kg-1 wet tissue vs 24.0 +/- 3.0 (P < 0.01); sodium 173 +/- 7 mmol.kg-1 dry tissue vs 275 +/- 38 (P < 0.05). No significant difference for Evans blue staining between the two groups. CONCLUSION: Nim had beneficial effect on the infectious BE.

Animals↗
PubMed1995

Site-specific isotope fractionation in the characterization of biochemical mechanisms. The glycolytic pathway.

For a given biochemical transformation, such as the fermentation reaction, the redistribution coefficients, which relate the natural site-specific isotope contents in end products to those of their precursors, are a source of mechanistic information. These coefficients characterize the traceability of specific hydrogens in the products (ethanol and water) to their parent hydrogens in the starting materials (glucose and water). In conditions of complete transformation, they also enable intermolecular exchanges with the water medium to be estimated. Thus it is directly confirmed that hydrogens 1, 2, 6, and 6' of glucose are strongly connected to the methyl site I of ethanol obtained by fermentation by Saccharomyces cerevisiae. However, whereas hydrogens 6 and 6' are transferred to a great extent, transfer is only partial for hydrogen 2, and it is even less for hydrogen 1. Because the two moieties of glucose corresponding to carbons 1-2-3 and 4-5-6 are scrambled by the aldolase and triosephosphate isomerase reactions, additional exchange of hydrogens at positions 1 and 2 must have occurred before these steps. The value of the coefficient that relates site 2 of glucose to site I of ethanol in particular can be used to quantify the contribution of intermolecular exchange occurring in the course of the transfer from site 2 of glucose 6-phosphate to site 1 of fructose 6-phosphate mediated by phosphoglucoisomerase. The average hydrogen isotope effects associated with the transfer of hydrogen from the water pool to the methyl or methylene site of ethanol are estimated. In contrast to conventional experiments carried out in strongly deuterium-enriched media where metabolic switching may occur, the NMR investigation of site-specific natural isotope fractionation, which operates at tracer isotopic abundance, faithfully describes the unperturbed metabolic pathways.

Deuterium↗
PubMed1995

Effect of response practice variables on learning spelling and sight vocabulary.

Four experiments were conducted to examine variables associated with response practice as an instructional technique for individuals with intellectual disabilities. In Experiment 1, the effect of the cover component in the "cover write" method was evaluated, as were the comparative effects of written versus oral practice of spelling words by rehabilitation clients. The results showed that the cover procedure generally did not enhance performance over and above that produced by practice alone, and written practice generally was not superior to oral practice. Experiment 2 demonstrated that less response practice (i.e., five times) was as effective as more practice (i.e., 10 and 15 times) for teaching spelling to adolescents with developmental disabilities. Experiments 3 and 4 also showed that even less response practice (i.e., one time) was as effective as more practice (five times), and irrelevant practice following errors was as effective as relevant practice for teaching spelling and sight vocabulary to adolescents with behavior disorders and developmental disabilities, respectively. The findings suggest that a parsimonious procedure of limited response practice and positive reinforcement may be effective for the tasks and populations studied.

Journal Article↗
PubMed1994

Pressure control of renal renin release in Lyon hypertensive rats.

OBJECTIVE: To assess whether the pressure-independence of renin release by isolated kidneys of Lyon hypertensive (LH) rats could result from long-term exposure to high blood pressure, sodium retention or an altered regulation of intracellular calcium through L-type voltage operated channels. DESIGN: Renin release was studied in kidneys from LH rats, either controls or chronically (aged 3-7 weeks) treated with hydralazine or deprived of sodium. The influence of L-type calcium channels was studied acutely using a specific activator (BAY K8644) or modulator (verapamil). Lyon low blood pressure (LL) rats served as controls. METHODS: Kidneys were isolated from LH or LL rats aged 7 weeks and single-pass perfused at three pressure levels: 70, 85 and 160 mmHg. RESULTS: LH rat kidneys differed from LL rat kidneys in having elevated vascular resistances, decreased glomerular filtration rate, pressure natriuresis and pressure-dependent renin release. Hydralazine treatment and sodium deprivation did not significantly modify the pressure-independence of renin release by LH rat kidneys. BAY K8644 (1 x 10(-8) and 5 x 10(-8) mol/l) induced significantly greater vasoconstrictor effects in LH than in LL rat kidneys but did not affect the renin release already stimulated by low perfusion pressure. Verapamil (5 x 10(-6) mol/l) dilated LH more than LL rat kidneys. It did not change the renin release observed at low, but enhanced it at high, perfusion pressure. This effect was more marked in LL than in LH rat kidneys. CONCLUSIONS: The poor stimulation of renin release by low perfusion pressure in LH rat kidneys does not appear to be a consequence of high blood pressure level, sodium retention and alteration in L-type calcium channels. However, results demonstrate that these channels participate in the increased vascular resistances exhibited by LH rat kidneys.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1994

[Infantile indirect inguinal hernia treated with laparoscopy high ligation of hernial sac].

22 cases of infantile indirect inguinal hernia were treated with laparoscopy high ligation of hernial sac. They were followed up for 9-18 months, the primary results were satisfactory and quite encouraging. The merits of this newly developed method are: The technique is relatively simple and less of postoperative complications. The technique and key point of the method were described in detail.

Child↗
PubMed1993

Effects of naftidrofuryl on isolated perfused kidneys of spontaneously hypertensive rats.

1. Experiments were designed to determine the effects of low concentrations (5-500 nmol/L) of naftidrofuryl, a 5-hydroxytryptamine (5-HT) antagonist, on renal functions and prostanoid synthesis responses to noradrenaline (NA) and 5-HT. Isolated kidneys of 8 week old male spontaneously hypertensive rats were perfused at a constant flow rate in a single-pass system. 2. In baseline conditions, naftidrofuryl did not modify the renal vascular resistance and the glomerular filtration rate (GFR), although it elicited a significant but not dose-dependent increase in the venous excretion of 6-keto-prostaglandin (PG) F1 alpha and thromboxane (Tx)B2, the stable end-products of PGI2 and TxA2, respectively. 3. NA increased renal vascular resistance and GFR in a dose-dependent manner and enhanced the venous excretion of 6-keto-PGF1 alpha and TxB2. Naftidrofuryl significantly attenuated the effects of NA on renal vascular resistance, abolished those on GFR and enhanced, at the highest concentration (500 nmol/L) only, those on 6-keto-PGF1 alpha excretion. 4. 5-HT increased renal vascular resistance but not GFR. It did not change the sodium excretion and the release of 6-keto-PGF1 alpha and TxB2. Naftidrofuryl blunted the RVR response to 5-HT without change in the prostanoid release. The inhibitory action of naftidrofuryl was not modified by indomethacin which, by itself, prevented the vasoconstrictor response to 5-HT.(ABSTRACT TRUNCATED AT 250 WORDS)

6-Ketoprostaglandin F1 alpha↗
PubMed1993

Eicosanoid-dependence of responses of pre- but not postglomerular vessels to noradrenaline in rat isolated kidneys.

1. We investigated the role of nitric oxide (NO) and of vasoactive eicosanoids in the control of renal vascular resistance (RVR) and glomerular filtration rate (GFR) and of their responses to noradrenaline (NA). This study was conducted in single-pass perfused, isolated kidney preparations of the rat. 2. NA (63, 110 and 160 nM) dose-dependently increased RVR and to a lesser degree GFR. 3. In baseline conditions, N omega-nitro-L-arginine methylester (L-NAME, 100 microM) increased GFR more than RVR, thus demonstrating a basal release of NO which predominates in postglomerular vessels. 4. In kidneys stimulated with NA, L-NAME potentiated the increases in RVR but not in GFR. Indomethacin (1.5, 150 nM and 15 microM) did not alter GFR but markedly and dose-dependently reduced the NA-induced increase in RVR. Similar results were obtained with GR 32191B (10 and 100 microM), a prostaglandin H2/thromboxane A2 (PGH2/TxA2) receptor antagonist. 5. Indomethacin (15 microM) suppressed the enhancing effects of L-NAME on RVR responses to NA but did not affect those on GFR. 6. It is concluded that the mechanisms of the response to NA differ among pre- and postglomerular vessels. In preglomerular vessels the vasoconstrictor action and the NO release depend upon the activation of PGH2/TxA2 receptors, while both are eicosanoid-independent in the postglomerular vessels.

Animals↗
PubMed1993

Techniques for isolating hair cells from guinea pig cochlea.

Isolated live hair cells are important models for studies on the electrophysiology, pathology and pharmacology of the hair cell. Using mechanical isolation method after papain treatment, 70 +/- 27 hair cells, including 0 to 4 inner hair cells, could be obtained from each cochlea of 4 guinea pigs. The criteria for a good viability of isolated cochlear hair cells were: 1) a smooth hair cell membrane; 2) hair cells not swollen; 3) the nucleus in normal position; 4) the cytoplasm in a state of translucence with a halo at the periphery (birefringence); and 5) no Brownian movement of the organelles within the cytoplasm. With short-term culturing at room temperature, approximately 90% of the isolated hair cells retained a good viability at the end of two hours. Subsequently, the hair cells gradually degenerated but still, at the end of five hours, about 40% of them appeared intact. The degeneration patterns have been carefully observed and described.

Animals↗
PubMed1991

[Regulatory effect of insulin on glucocorticoid receptor in human peripheral leukocytes].

The regulatory effect of insulin on the specific binding power of glucocorticoid receptor (GR) of human leukocytes was assessed by the unoccupied receptor sites capable of combining with [3H] labelled dexamethasone measured at 3 and 24 h after incubation with various concentrations of insulin added to the medium. After 3 h incubation the specific binding power with [3H] Dex was decreased by 23.3 +/- 10.0, 32.2 +/- 13.2 and 54.3 +/- 9.2% (P greater than 0.05, P greater than 0.05 and P less than 0.01 as compared with the control value of 100 in the absence of insulin) respectively in the presence of 20 mU/L (physiological testing concentration), 200 mU/L (physiological upper limit) and 2,000 mU/L (pharmacological concentration) insulin in the incubation medium. After 24 h incubation the decrease of these values increased respectively to 43.5 +/- 19.0, 56.1 +/- 20.7 and 80.2 +/- 15.5 (P less than 0.05, P less than 0.01 and P less than 0.01 compared with control). Thus the inhibitory effect of insulin on the GR binding power is both dose- and time-dependent, which strongly suggests that GR is tonically controlled by insulin concentration change under physiological conditions.

Cells, Cultured↗
PubMed1991

Twenty-item behavioral neurological assessment for normal newborns in 12 cities of China.

Based on the method of Brazelton and Amiel-Tison for behavioral neurological measurement in the newborn and our own experience, we formulated a 20-item neonatal behavioral neurological assessment (NBNA). For setting up a practical method and a normal range of its scores in China, we examined 714 normal newborns (male 369, female 345), with NBNA at the age of 2-3, 12-14, 26-28 days for a total of 2,142 times, in 12 provinces of China from May to October 1988. NBNA contains 5 clusters: behavior (6 items); passive tone (4 items); active tone (4 items); primary reflexes (3 items); and general assessment (3 items). Each item has 3 scales (0,1,2). Twenty items have a maximum of 40 scores. Among the 2,142 times examined, 90.4% of the 714 newborns had 39-40 scores, 97% greater than 37 and none below 35. Measurements of the first, second and third time revealed that the total scores increased with age. The difference was statistically significant. The abilities of auditory and visual orientations and active neck tone improved obviously with age. NBNA shows distinct stability and reliability. The score is not influenced by geographic location; the scoring system is simple and the manipulation takes only ten minutes.

Birth Injuries↗
PubMed1990

[Purge of malignant cells from bone marrow by hematoporphyrin derivatives and light exposure in vitro].

During autologous bone marrow graft in treatment of malignant diseases, it is critical to purge malignant cells from the marrow. In the present study, the sensitivity to photodynamic inactivation of 3 leukemic cell lines was compared with their counterpart normal hematopoietic cells. After mouse leukemic L1210 cells were treated with a preparation of hematoporphyrin derivatives, YHpD, 10 micrograms/ml for 1 h and irradiated with black light (peak wavelength 395 nm, light intensity 0.6 mW/cm2) for 5 min, the survival rate of clonogenic cells decreased to less than 10%, while that of bone marrow granulocyte-macrophage progenitor cells (CFU-GM) in DBA/2 mice remained at nearly normal level (greater than 80%). Similar results were obtained when human leukemic HL-60 cells were compared to human CFU-GM and mouse leukemic L615 cells to CFU-GM in 615 strain mice. It is suggested that hematoporphyrin photoradiation may be useful for selectivity killing leukemic cells in bone marrow.

Animals↗
PubMed1990

Developmental studies of electrical properties in cultured rat brain neurons.

The rat brain neurons isolated from 15--17-day embryos were grown in dissociated cell culture and maintained in vitro for 3 weeks. The developmental process of the neurons was observed from the early stage of development in terms of passive and active electrical parameters and their changes induced by perfusion of ionic channel blockers. The neurons' development could be morphologically divided into stages I (from seedling to 6 days), II (7-11 days), III (12-20 days) and IV (21-22 days). The relative values of resting membrane potentials (RMP) for stages I, II, III and IV were 1, 3.46, 4.07 and 6.54, respectively; the corresponding values of input resistance (Rin) were 1, 1.48, 2.53 and 4.56, respectively. The current-voltage relationship in stages II and III was exponential in the direction of depolarization and the Rin's change with time was nearly linear. Spontaneous activities increased with prolongation of culture and the amplitude of evoked action potentials reached the maximum during stages III and IV. The RMP and Rin were markedly decreased by perfusion of TEA while no change was seen in TTX perfusion group. The results indicate that potassium ionic channels develop slower in stages II and IV, faster in stages I and III and mature by the end of stage IV.

Animals↗
PubMed1989

[An analysis of blood cell pouring on the tongue surface in 3032 healthy persons].

This paper deals with the utilizing laser frequency multiplexing technique and Doppler effect, successfully to build up LDB-1 type of laser microcirculation blood flow meter. It was used to carry on a determination for blood cell pouring amount on tongue surface in 3032 healthy persons. The results were shown as follows. The average tongue blood cell pouring amount of healthy persons was 4.74 +/- 0.50, in which the male was 4.82 +/- 0.50, and the female was 4.66 +/- 0.49. Apparently, there was a great difference between them (P less than 0.01). Following the increase of age, the tongue blood cell pouring amount was gradually decreased. The average blood cell pouring amount of a group of 1-9 years old was 6.14 +/- 0.79, of over 60 years old was 3.89 +/- 0.39 (P less than 0.01). In the light red tongue, the average tongue blood cell pouring amount was 4.95 +/- 0.93, which was considered to be the highest; in the purple tongue, it was 3.96 +/- 0.44 which was considered the lowest. The average pouring amount in the red tongue was 4.94 +/- 0.77, and in the light white tongue was 4.21 +/- 0.52. The more red the tongue showed, the greater the tongue blood cell pouring amount would be; whereas, the more purple the tongue showed, the lower the tongue blood cell pouring amount would be. It obviously indicated that the tongue blood cell pouring amount would be. It obviously indicated that the tongue blood cell pouring amount could correctly reflect the different tongue characters and tongue blood circulation condition.

Adolescent↗