Biomedical subjects

Q Zhang

Publications and source records attributed to Q Zhang.

At least 739 records · Page 41Linked to original sources

PubMed1996

Single 5'green-3'red hybrid gene in protanopia.

PURPOSE: To disclose the structure of visual pigment gene for a protanopia with specific variation. METHODS: Exon 5 fragments of the red and green visual pigment genes from the protanopia with specific variation as well as controls were amplified by polymerase chain reaction (PCR). The PCR products were put through heteroduplex-SSCP analysis and PCR-RFLP (restriction fragment length polymorphism) analysis to clarify the specific variation. The specific variation of the exon 5 DNA fragment from the protanopia was identified by sequencing. RESULTS: A novel 5'green-3'red hybrid gene fragment without the normal red and green visual pigment gene was discovered in the protanopia. He should only have a single visual pigment gene, 5'green-3'red hybrid gene, on his X chromosome. The fusion point is between codon 285 and codon 296 in exon 5. CONCLUSION: Unequal intragenic recombination may occur in exon 5 as well as its upstream. A 5'green-3'red hybrid gene may present independently on the X chromosome without accompanying the red or green visual pigment gene. Single visual pigment gene with 5'green-3'red hybrid fragment of exon 5 could express function which is similar to the green pigment gene. This example also gives in vivo evidence that codons 277 and 285, rather than codon 309, play a major role in tuning the absorption spectra of the red and green visual pigments.

Amino Acid Sequence↗

PubMed1996

[Study on nurse-patient relationships in patients with fractures and traumatic delirium].

Having obvious psychical defect, the fractured patients were different from other orthopedical patients. The characteristics of disease courses of 63 patients were analyzed in this study. The result indicated that at the time of pre-operation, the end of first post-operation week, and the end of second post-operation week there were significant difference in patients' psychical condition (P < 0.05). At the end of third post-operation week, the physical trauma were cured and their psychical condition turned to be almost normal. It may related to the nurse patient relationship model, active-passive model, and guidance-cooperation model which were used during deliria period, recovering period, and smooth period. Using these models effectively may improve the recovery of the patients physically and psychologically.

Adolescent↗

PubMed1996

[Dynamic study of tissues and structures in "de qi" acupoint].

Guinea pigs were acupunctured at "ZuSanli" (ST 36) with one direction twirling manipulation until an objective sensantion was felt by operator's hand. Frozen sections and scanning electromicroscopic specimens were made from the whole guinea leg acupunctured and were observed under light microscope and scanning electromicroscope respectively. In all specimens, a puncturing pore and different transformation of surrounding tissue were seen clearly. In hypodermis the connective tissue fibers circling the puncturing pore appeared as whirly form. In muscle layer, the connective tissue fibers of endomysium circled the pore and the relative muscle fiber were twisted and dislocated. Adjacent vessels and nerves were dislocated and transformed. It is infered that various needling sensative tissues and structures were simultaneously stimulated by twirling needle force, with connective tissue being as mediator, which is likely of the biological basis of needling sensation and ist complexity.

Acupuncture Points↗

PubMed1996

[Transplantation of the remedial free anteromedial thigh flap].

Over one hundred and twenty free anterolateral thigh flaps have been performed since 1988, of which ten were operated as free anteromedial flaps because the nutrient vessels emerged from the medial intermuscular space formed by the sartorius, the rectus femoris and vastus medialis muscles. Clinical study indicated that there were three types of nutrient cutaneous arteries in the space: type 1, the medial branch of the descending branch of the lateral circumflex femoral artery in 6 cases; type 2, the superficial femoris artery in 2 cases; and type 3, the branch of the femoris artery in 2 cases. The name of the flap, the operation technique and the compensative characteristics of the arteries are discussed.

Adolescent↗

PubMed1996

[Usefulness of the reversed island fasciocutaneous flap of lower leg in plastic surgery].

A total of 14 patients with scars or ulcer on their dorsum of the foot, heel, medial or lateral malleolus were treated with the reversed island fasciocutaneous flap of the lower leg. After the scars or ulcer were excised, the flap was transferred through a subcutaneous tunnel. All the operations were successful and primary healing was achieved. The surgery was easy without sacrificing a big vessel. The flap supported by rich blood supply demonstrated high viability. The authors believe that the reversed island fasciocutaneous flap of the lower leg is an ideal flap for repair of the defects on the foot.

Adolescent↗

PubMed1996

[Establishment of cervical lymph node metastasis in model rats and its microcirculation characteristics].

To determine the effects of vasoactive agents on blood flow in lymph node metastases, the blood flow in the cervical lymph node metastases and normal tissue were meassured using a hydrogen clearance method, at normotensive state, angiotensin I (A I) induced hypertensive state and sodium nitroprusside (SNP) induced hypotensive state. The metastases occurred frequently in the cervical lymph nodes of 17 rats on day 11-14 after Yoshida ascites hepatoma. AH109A cells were subcutaneously inoculated into back of auricule of 20 rats. The blood flow in the liver, brain and bone marrow of normal rats was of no significant changes when the mean arterial blood pressure (MABP) was elevated to approximately 20 kPa by infusion of A I and decreased to approximately 9.06 kPa by infusion of SNP. But the blood flow in the metastatic lymph nodes was increased from 1.42 +/- 0.48 ml.kg-1/s to 3.45 +/- 1.33 ml.kg-1/s (n = 13, P < 0.05) when the MABP was elevated from 14.81 +/- 1.04 kPa to 18.93 +/- 0.92 kPa by A I. On the contrary, the blood flow in the metastatic lymph node was decreased to 0.55 +/- 0.25 ml.kg-1/s (n = 13, P < 0.05) when the MABP was decreased to 8.84 +/- 0.63 kPa by SNP. The results indicated that microcirculation characteristics in the cervical lymph node metastases were different from those in the normal tissues. A I induced hypertension was useful to selectively improve delivery of chemotherapeutic drugs to the site of metastases. On the other hand, SNP induced hypotension may be useful to suppress washout of the drugs.

Animals↗

PubMed1996

[The electricity properties of polybutylcyanoacrylate nanoparticles].

Electricity properties of polybutylcyanoacrylate nanoparticles (PBCA-NP) were studied by using a U-tube electrophoresis apparatus. It was proved that all the PBCA-NP is negatively charged. The surface potential of PBCA-NP is directly proportional to the concentration of stabilizer (Dextran 70) and the pH value of the medium, while it is inversely proportional to the concentration of butylcyanoacrylate and the model drug (gentamycin). The effect of ion strength on surface potential is obvious but not linear. The effect of stabilizers and surfactants used on the surface potential is evident while the effect of electrolytes is indistinct under the experimental conditions.

Dextrans↗

PubMed1996

[Armillifer agkistrodontis disease: report of case].

A case of Armillifer agkistrodontis disease was reported. Armillifer agkistrodontis is a species of the Armillifer genus of the Linguatulida order and parasitizing agkistrodon acutus. According to literature reviewed, there has been no report of this disease caused by infection of Armillifer agkistrodontis in human being prior to this case all over the world. The clinical features of this disease are long-term high fever, abdominal pain, diarrhea, mild anemia, hepatosplenomegaly, eosinophilia in bone marrow and blood and multiple polyps in the whole colon. The pathologic features of the liver biopsy was degeneration and necrosis of hepatocytes and obvious infiltration of eosinophils. This disease should be differentiated from several other diseases which can also cause hepatomegaly, long-term high fever, abdominal pain and diarrhea. Mebendazole is an effective medication for this disease, but the long term effect of praziquantel is not certain. It is necessary to make further studies on the epidemiology, etiology, pathology, natural history, clinical features, diagnosis, differential diagnosis and therapy of this disease.

Adult↗

PubMed1996

[Detection of serum HCV RNA and HBV DNA in patients on hemodialysis].

In order to assess the relationship between seropositivity and potential infectivity caused by hepatitis C virus (HCV) and hepatitis B virus (HBV) in patients undergoing maintenance hemodialysis, 22 patients in our dialysis unit were evaluated by using nested RT-PCR to detect serum HCV RNA, ELISA to detect serum anti-HCV antibodies, dot blot to detect serum HBV DNA and RIA to detect HBV serum markers. Twenty-seven percent of the patients (6 of 22) was anti-HCV-positive. Of the 6 anti-HCV-positive patients, HCV RNA was detected in 3 (33%) patients. Among the anti-HCV-negative patients, HCV RNA was detected in one (6%) of the 16 patients. Fourteen percent (3 of 22) was HBV DNA-positive. Of the 3 HBV DNA-positive patients, HBeAG was detected in all of them. Among the nineteen HBV DNA-negative patients, no HBeAg was detected, but anti-HBc was detected in 12 (63%) of the 19 patients. Five of the seven patients with HCV infection (HCV-Ab and/or HCV RNA-positive) had evidence of additional present or past hepatitis B virus infection (4 of the 5 patients were anti-HBc-positive and one of the 5 was HBV DNA, HBeAg, HBsAg, and anti-HBc-positive). However, no HCV RNA and HBV DNA were found to coexist in the same patient in this study. These data indicate that many patients on hemodialysis have hepatitis C or B viremia and more attention should be paid to this problem.

DNA, Viral↗

PubMed1996

[The path of gastric lymphatic drainage and its significance for redical resection of gastric carcinoma].

By dissecting 31 corpses' stomach and then thining the gastric lymphatic system with prussian blue staining, we found out that the gastric lymphatic return from the visceral surface to the parietal pleura mainly takes three ways: a lymphatic nodes of the coelica artery trunk, a lymphatic nodes beside the superior mesenteric artery, and lymphatic nodes beside the left inferior phrenic. The lympha of these paths flew to the parietal pleura around the left renal viens. This result can give reference to cleaning lymphatic nodes beside abdominal aorta during the radical operation of gastric carcinoma.

Aorta, Abdominal↗

PubMed1996

Detection of RB germline mutations using exon-by-exon heteroduplex analysis compared with SSCP.

PURPOSE: To compare heteroduplex analysis with SSCP and to develop a simple and effective method for mutational screening of RB gene. MATERIALS AND METHODS: Leukocyte DNA was prepared from 12 unrelated Japanese patients with hereditary retinoblstoma. PCR combined with simultaneous nonisotopic heteroduplex and SSCP analysis was used to screen leukocyte DNA for such mutations, exon-by-exon, without the use of restriction endonuclease digestion. PCR was conducted using 28 pairs of primers flanking all 27 exons and the promoter region of the RB gene, with PCR products ranging from 159bp to 326bp. Mutations were identified by sequencing. RESULTS: Heterozygous germline mutations were detected in 8 of 12 Japanese patients. The mutations were identified by sequencing as follows: G-->C/acceptor of exon 11, T insertion/codon 389, C-->T/codon 455, 33bp insertion/codon 455 (C decreases GA), G-->T/codon 533, C-->T/codon 579, C deletion/codon 674, and C-->T/codon 787. CONCLUSION: Our results suggest that small RB gene mutations are common. Heteroduplex analysis has advantage over SSCP and they may complement each other for the rapid detection of unknown mutations.

DNA, Neoplasm↗

PubMed1996

[Quality control of semen Cassiae].

A reversed-phase HPLC method was developed for determination of chrysophanol in Semen Cassiae. The extraction conditions were examined for free and combined chrysophanols. 14 samples collected from 6 different areas were determined. The average recoveries for two kinds of compounds were 101.2% and 103.3% respectively, and the RSDs were 3.5% and 1.8%.

Anthraquinones↗

PubMed1996

[Influence of temperature on the chemical constituents and pharmacological effects of semen Cassiae].

The influence of temperature on the chemical constituents and pharmacological effects of seeds of Cassia tora was examined. As the baking temperature was raised, the contents of free chrysophanol increased. The contents of antihepatotoxic constituents in the samples baked at different temperatures were compared. They decreased as the temperature rose. The pharmacological results basically accorded with the contents of the constituents.

Alanine Transaminase↗

PubMed1995

The experimental hardness and electronegativity of the purines and pyrimidines in DNA and RNA supported by the AM1 calculation of the electron affinities and ionization potentials.

The ionization potential and electron affinities of the purines and pyrimidines in DNA and RNA were calculated with the AM1 semiempirical method. The values support the experimental values. The electron affinities are significant, and positive, such that donor-acceptor interactions can, and indeed should play a role in the stacking of bases in nucleic acids. Based on the confirmation of the experimental values by the theoretical calculations, reliable values of the experimental hardness and electronegativity were calculated.

Chemical Phenomena↗

PubMed1995

Expression of pituitary adenylate cyclase-activating polypeptide in dorsal root ganglia following axotomy: time course and coexistence.

Pituitary adenylate cyclase-activating polypeptide (PACAP) has recently been demonstrated in sensory neurons. In the present study on rat 17.5% of all neurons, mainly of small size, contained PACAP in normal dorsal root ganglia (DRGs). Transection of the sciatic nerve induced a rapid and strong upregulation in PACAP peptide and mRNA levels which could be seen already after 15 h. After 3 days more than 51.5% of neurons of different sizes expressed PACAP. However, the intensity of PACAP-LI in the DRG neurons declined after 10 days. Thirty days after axotomy, 56.7% of the DRG neurons still expressed PACAP, but with a low intensity, in fact even lower than in normal controls. No VIP- or NPY-positive neurons were observed in normal or axotomized DRGs at 15 h. However a distinct increase in VIP and NPY levels were seen 3 days after the lesion, and their levels were considerably higher after 30 days. PACAP was often present in neurons expressing VIP, NPY and/or galanin. Thus, 3 days after injury, PACAP was present in 84.4%, 95.7%, and 76.8% of the VIP-, NPY-, and galanin-positive neurons, respectively. PACAP was also found in nerve fibers in control sciatic nerves. After nerve ligation, accumulation of PACAP was seen mainly proximal to the injury but also distally, suggesting both anterograde and retrograde transport of the peptide. Also a moderate increase (about 20%) in PACAP levels was found in the superficial spinal dorsal horn 3 days after nerve transection. Taken together, our results suggest that PACAP is involved in the response to nerve injury. The very high levels of expression in different populations of DRG neurons after axotomy, and its different time course as compared to galanin, NPY and VIP indicate that it may play a complementary and/or different role than these peptides in the adaptation to nerve injury, especially in its early phase.

Animals↗

PubMed1995

In vivo binding of trimethylpsoralen detects DNA structural alterations associated with transcribing regions in the human beta-globin cluster.

In order to increase our knowledge about the mechanisms that regulate expression of human beta-like globin genes, we have used a novel technique to analyze the chromatin structure in living cells. This approach allowed us to detect specific DNA regions in vivo where nucleosome folding or unconstrained DNA supercoiling in erythroid cells differs from that in non-erythroid cells. In this method, we use 4,5',8-trimethylpsoralen (TMP) as a probe capable of detecting altered chromatin conformations. Our results show that TMP binds to DNA with a higher affinity over the regions in the locus that are actively expressed, including both the promoter and the transcribed region. This higher affinity detected when comparing erythroid cells with non-erythroid cells does not extend to other regions inside the beta-globin cluster. Our data suggest that the observed effect is likely due to nucleosome displacement. Alternatively, it could result from localized DNA supercoiling, but not from widespread torsional stress across the entire beta-like globin locus as hypothesized previously.

Base Sequence↗

PubMed1995

Prominent expression of bFGF in dorsal root ganglia after axotomy.

Using quantitative in situ hybridization and immunohistochemistry the expression of acidic and basic fibroblast growth factors (aFGF, bFGF) in dorsal root ganglia (DRGs) was examined. Around 5% of the small neurons expressed bFGF mRNA in normal DRGs. Nerve injury induced a very dramatic and rapid up-regulation in bFGF mRNA levels, and around 80% of all DRG neurons expressed bFGF mRNA 3 days after axotomy. A distinct increase in bFGF-like immunoreactivity (LI) was also detected as early as 15 h after axotomy. The elevation of bFGF mRNA and protein levels declined after 1 week. bFGF mRNA was also up-regulated in non-neuronal cells following axotomy. Normally bFGF-LI was mainly localized in the nuclei of DRG neurons and in some non-neuronal cells. After nerve section, bFGF-LI was in addition found in the cytoplasm, and many more bFGF-positive non-neuronal cells were observed. By means of confocal microscopy analysis of axotomized DRGs, some bFGF-LI could be detected in vesicle-like structures in the cytoplasm as well as in the nucleoli, in addition to the nuclear location. Application of leukaemia inhibitory factor to the transected sciatic nerve significantly increased the number of bFGF-positive neurons, whereas the bFGF-LI in non-neuronal cells was strongly suppressed. About 70% of the normal DRG neurons expressed aFGF mRNA and aFGF-LI. Axotomy produced a moderate increase in aFGF mRNA levels, but no detectable effect on protein levels. Taken together, the results show that bFGF may be involved in the neuronal response to injury and suggest a role in neuronal survival and regeneration in axotomized DRG neurons.

Animals↗

PubMed1995

Carrier frequency of the IVS4 + 4 A-->T mutation of the Fanconi anemia gene FAC in the Ashkenazi Jewish population.

Fanconi anemia (FA) is a genetically and phenotypically heterogeneous autosomal recessive disorder defined by a cellular hypersensitivity to DNA cross-linking agents. One of the FA genes, FAC, has been cloned and the genomic structure of the coding region has been characterized. We have developed amplification refractory mutation system (ARMS) assays for five known mutations in FAC, and have applied these assays to determine the carrier frequency of the IVS4 + 4 A-->T (IVS4) mutation in an Ashkenazi Jewish population. We tested 3,104 Jewish individuals, primarily of Ashkenazi descent, for the two most common FAC mutations, IVS4 and 322delG. Thirty-five IVS4 carriers were identified, for a carrier frequency of 1 in 89 (1.1%; 95% confidence interval 0.79% to 1.56%); no 322delG carriers were found. To determine if the IVS4 mutation was confined to the Ashkenazi Jewish population, we tested 563 Iraqi Jews for IVS4, and no carriers were found. Because the IVS4 mutation has only been found on chromosomes of Ashkenazi Jewish origin and is the only FAC mutation found on these chromosomes, we suggest that a founder effect is responsible for the high frequency of this mutation. With a carrier frequency greater than 1% and simple testing available, the IVS4 mutation merits inclusion in the battery of tests routinely provided to the Jewish population.

Base Sequence↗