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H Bao

Publications and source records attributed to H Bao.

27 records · Page 2Linked to original sources
PubMed1997

[Gas chromatographic analysis of fatty acids in phosphatidylglycerol from needles of two crosses of Chinese Fir].

This paper reports a method for determination of fatty acids in phosphatidylglycerol from needles of two crosses of Chinese Fir with different cold-resistance. Some simplifications and improvements for analytical method of DEAE CL-6B column chromatography and of silica thin layer chromatography were also discussed. After being extracted with chloroform and methanol, phosphatidylglycerol was isolated from the general lipid extract by using DEAE CL-6B IEC and Silica TLC. Quantitative analysis was conducted by gas chromatography on a DB-FFAP (30m x 0.32mm i.d.) column. The results showed that there was a difference in the ratio of fatty acid (18:1+18:2+18:3)/[16:0+16:1(3t)] between the two crosses of Chinese Fir with different cold-resistance, 1.12 for that with higher cold-resistance and 1.25 for that with lower cold-resistance. A special fatty acid 16:1(3t) was found in both of the two crosses.

Chromatography, Gas↗
PubMed1996

Cholecystokinin octapeptide reverses the inhibitory effect induced by electroacupuncture on C-fiber evoked discharges.

Extracellular single unit recordings were made from spinal dorsal horn wide dynamic range neurons in spinal transected, urethane-anesthetized rats. The unit discharges elicited by noxious electrical stimulation of the hind paw were suppressed by electroacupuncture (15 Hz, 0.3 ms, 3 mA, 30 min) placed at the hind leg points (S-36 and SP-6). Local spinal superfusion with naloxone (20 micrograms/15 microliters) or CCK-8 (10 ng/15 microliters) attenuated, whereas CCK-B receptor antagonist L365,260 (2.5 micrograms/15 microliters) enhanced the electroacupuncture effect. These findings provide further evidence for the notion that CCK-8, in the spinal cord, functions as an antiopioid substrate that antagonizes opioid- or electroacupuncture-induced analgesia.

Animals↗
PubMed1995

Development of intrinsic electrophysiological properties in neurons from the gustatory region of rat nucleus of solitary tract.

There is no current understanding of the nature or time course of maturation of intrinsic electrophysiological properties for neurons in the gustatory region of the nucleus of the solitary tract (NST). Therefore, we used whole cell recordings in an in vitro slice preparation of the rat brainstem to characterize development of resting membrane, action potential and repetitive discharge properties of cells in gustatory NST at postnatal days 5, 10, 15, 20, and 30, and adult ages. Neurons were filled with Biocytin to verify location and characterize morphology. Membranes from younger neurons demonstrated a steeper current-voltage relation or higher input resistance, and a longer time constant than mature cells. Action potentials in younger cells had a slower rate of rise and were longer in duration. The afterhyperpolarization that typically follows the spike discharge usually had one phase in younger neurons, but was characterized by two or more phases in an increasing proportion of older cells. The repetitive discharge frequency in response to a range of depolarizing current pulses increased during development, and frequency/current plots were steeper in older compared with younger neurons. However, in all age groups there was clear accommodation of the discharge frequency. The greatest changes in resting membrane, action potential, and discharge properties were observed between P5 and P15, and mature values were generally reached by P20. At each postnatal age, neurons could be categorized in four neuron groups, based on the discharge pattern in response to a hyperpolarizing/depolarizing current protocol. Anatomical reconstructions indicated that although cells increased in overall dendritic expanse during development, neurons became less complex as illustrated by decreases in number of dendritic branch points, and in number and density of spines. The timing of major developmental differences in intrinsic electrical characteristics observed here is associated with a period of previously reported maturational changes in extracellular taste responses to number and concentration of chemical stimuli. However, further alterations in extracellular taste responses proceed after apparent maturation of intrinsic neural properties.

Action Potentials↗
PubMed1995

High-level expression of the human tumor necrosis factor-alpha.

Five expression plasmids for a total chemically synthesized gene of tumor necrosis factor-alpha (TNF-alpha) were constructed, which differ in two aspects: 1) distance (D) between the SD and the initiation codon ATG; 2) energy-delta G0f298 released to form the stable secondary structure in the translation initiation region. The plasmid with a (D) of 6bp has the lowest delta G0f298 (absolute value) and showed the highest expression level, up to 60% of the total bacterial proteins. Codons usage will impose much influence on expression level, so it is reasonable and understandable that the total chemically synthesized TNF-alpha gene with the codons preferable to E. coli use gave much higher expression level than the sc-TNF-alpha in which only partial N-terminal codons were modified.

Base Sequence↗
PubMed1995

[Histochemical changes in Brugia malayi microfilariae-infected Anopheles sinensis].

Histochemical changes in normal and Brugia malayi microfilariae-infected Anopheles sinensis were observed using histochemical technique. The results showed that the activity of alkaline phosphatase (AKP) and acid phosphatase (ACP) and the content of glycogen and basic protein in Brugia malayi microfilariae-infected Anopheles sinensis were less obviously than those of the normal control. Esterase (EST) activity was reduced slightly and acetylcholinesterase (AChE) remained no change in infected mosquitoes compared with the normal control. It is suggested that the development of filaria larvae in vector mosquitoes has selective effect on their biochemical metabolism.

Acid Phosphatase↗
PubMed1995

[Studies on elements in Anopheles sinensis infected with Brugia malayi microfilariae].

Amounts of Certain elements in Anopheles sinensis, both normal ones (emerged mosquitoes, d0, d5, d8, d12 and d18 after taking blood meal) and those infected with Brugia malayi microfilaria (d5, d8, d12 and d18 after infection), were determined using IL-551 and PE-603 atomic absorption spectrometer (AAS). The results showed that 9 kinds of trace elements including Fe, Zn, Cu, Cd, Al, Pb, Mn, Ni and Cr and 4 kinds of macro elements as K, Na, Ca, Mg were present in both the noninfected and infected mosquitoes. Comparing the contents of the elements between the noninfected and infected mosquitoes, the amounts of many kinds of elements reduced obviously in mosquitoes infected with microfilaria. The quantity and kinds of elements reduced in mosquitoes with the days of infection, for instance, 10 kinds of elements on the 5th day, 11 on the 8th day, 9 on the 12th day and 7 on the 18th day after infection (Tables 1, 2).

Animals↗
PubMed1991

[C fiber is not necessary in electroacupuncture analgesia, but necessary in diffuse noxious inhibitory controls (DNIC)].

Experiments were carried on rats. We applied capsaicin topically on sciatic nerve and used the techniques of extracellular recording and nerve trunk recording, Our results showed that the size of C compound action potentials in nerve trunk and C fiber response of spinal cord WDR neurons were decreased by at least 70% (mean) after topical application of capsaicin (250 micrograms) on the nerve, but A compound action potentials and A fiber response did not change significantly. It indicated that capsaicin blocked C fiber conduction selectively. Electroacupuncture (EA: 100 Hz, 0.1 ms, 3V) applied on left Zusanli (S36) and Sanyinjiao (Sp6) points inhibited C fiber response of spinal WDR neurons in the right side. The effect was similar to animal behavior analgesia elicited by EA. After applying capsaicin (250 micrograms) topically on left sciatic nerve, the inhibitory effect of EA on WDR neurons remained essentially intact (from 61.3 +/- 12.0% to 59.0 +/- 11.6%, n = 6, P greater than 0.05). It indicated that C fiber was not important in EA analgesia. Noxious heat (NH) applied on left hind paw by immersing the hind paw into 52 degrees C water inhibited C fiber response of spinal WDR neurons in the right side. It was called diffuse noxious inhibitory controls (DNIC). After applying capsaicin (250 micrograms) topically on left sciatic nerve, the inhibitory effect of NH on WDR neurons was dramatically decreased (from 77.7 +/- 8.5% to 8.1 +/- 8.9%, n = 6, P less than 0.001). It indicated that C fiber was important in DNIC. Both inhibitory effects of NH and EA were not changed by vehicle treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗
PubMed1990

Preferred translation of human hepatitis B virus polymerase from core protein- but not from precore protein-specific transcript.

In the human hepatitis B virus (HBV) genome, the 5' end of the polymerase coding sequence overlaps with the 3' end of the core protein coding sequence. Recent results obtained from genetic studies have suggested that translation of HBV polymerase initiates from the first ATG codon of the polymerase reading frame and is not a result of frameshift translation from the core protein reading frame, as in the case of retroviruses. By using in vitro-synthesized SP6 RNA transcripts, we now demonstrate that HBV core protein-specific mRNA can direct the synthesis of polymerase from the internal polymerase ATG codon in rabbit reticulocyte lysates and Xenopus oocytes. A related message with an additional 60 nucleotides at the 5' end (pre-core protein mRNA) was not as efficient as the core protein mRNA for translation of polymerase. Furthermore, translation of polymerase from the core protein mRNA was not inhibited by the cap analog m7GpppG. This result, together with the results described above, indicates that translation of HBV polymerase occurs in a novel, cap-independent manner.

Animals↗