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Biomedical subjects

J Jiang

Publications and source records attributed to J Jiang.

At least 397 records · Page 22Linked to original sources
PubMed1995

Clinical measurement of mucosal wave velocity using simultaneous photoglottography and laryngostroboscopy.

Simultaneous glottal transillumination or photoglottography (PGG), electroglottography (EGG), and video laryngostroboscopy were used to measure the traveling wave velocity of the vibrating vocal folds during phonation in human subjects. The duration of travel was calibrated from the PGG signal, while the displacement of the upper and lower lips of the vibrating vocal folds was calibrated from parallel laser beams projected onto the vocal folds. The mucosal wave velocity varied with the portion of the glottal cycle. The amplitude of displacement correlated positively with the intensity of phonation and negatively with the fundamental frequency and was decreased for breathy and pressed phonation modes. The velocity of the opening phase segment of the PGG signal directly correlated with the top lip displacement of the vibrating vocal fold, and bottom lip displacement correlated with the closing phase of the PGG signal. Therefore, with suitable calibration, the effects of mucosal lateral displacement may be measured from a PGG signal. Simultaneous measures of PGG, EGG, and stroboscopy provide a three-dimensional representation of glottal vibration that can be numerically analyzed.

Adult↗
PubMed1995

Differential detection of rat islet and brain glutamic acid decarboxylase (GAD) isoforms with sequence-specific peptide antibodies.

We studied the distribution of the M(r) 65,000 and M(r) 67,000 isoforms of glutamic acid decarboxylase, GAD65 and GAD67, in rat islets and brain by immunocytochemistry. Synthetic peptides representing selected GAD65 or GAD67 sequences were used to produce sequence-specific antibodies, allowing differential immunocytochemical detection of the two isoforms. GAD-specific reactivity of each peptide antiserum was confirmed by ELISA, immunoblotting, and immunoprecipitation. Immunostaining specificity was verified by displacement with either immunizing or irrelevant peptide. Dual immunostaining with GAD isoform-specific antibodies and polyclonal antibodies to glucagon showed that GAD65 was primarily detected in rat pancreatic islet beta-cells, whereas alpha-cells had weak GAD65 staining. In contrast, GAD67 was detected primarily in alpha-cells. In rat brain, GAD65 and GAD67 were present in neuron cell bodies and processes. These data demonstrate that antibodies raised against the N-terminus of GAD allow differential immunocytochemical identification of GAD67 and GAD65. Differential expression of GAD isoforms within islet alpha- and beta-cells supports the role of GAD65 in autoimmune diabetes and stiff-man syndrome.

Animals↗
PubMed1995

Direct preparation and meiotic analysis of human semen.

A meiotic study of human semen specimens was carried out in 60 cases. Among them, 20 were normal controls, 20 suffered from infertility, and 20 had a history of recurrent spontaneous abortions. Of the cases of infertility and abortion, 50% were found to have numerical and/or structural chromosomal aberrations in spite of the normal blood karyotype. It is suggested that chromosomal aberrations may be the cause of sterility and abortion. The success rate of semen chromosome G-banding in the infertility, abortion and control groups was 70%, 55% and 25% respectively. The semen samples of three cases of heterozygous carriers with reciprocal chromosomal translocation were also studied. The ring quadrivalents were identified in all cases. The results may explain the recurrent abortions in these patients.

Abortion, Habitual↗
PubMed1995

Randomized case-controlled trial of oral low-dose acyclovir for prevention of virus infections in recipients of renal allografts.

A randomized case-controlled trial of oral low-dose acyclovir (600-800 mg per day) has been conducted for the prevention of virus infections in 66 recipients of renal allografts since 1990. In comparison with the untreated controls, acyclovir could prevent herpes virus simplex (HSV), reduce morbidity of pneumonia from 10 cases (30%) to 3 cases (9%) (P < 0.05) and lower CMV-IgM positive rate from 30% to 12%. Serum Cr and BUN in acyclovir group were lower than those in control group. These results strongly suggested that oral administration low-dose acyclovir could prevent virus infections after renal transplantation.

Acyclovir↗
PubMed1995

[Surgical treatment of carcinoma of low rectum].

1230 cases of low rectal cancer were treated surgically from 1954 through 1990 with a resectability rate of 79.92% and a curative resectability rate of 63.98%. Among curative resections, abdomino-perineal excision accounted for 71.16% and sphincter-saving resection for 28.84%. Before 1980, 19.19% cases were treated with SSR and since 1980 it was raisen to 41.04%. In comparison of the results of group before 1980 with those since 1980, the mortality rate of curative resection was 1.56% and 0.99% respectively. The 5-year survival rate of curative resection (life table method) was 58.96% +/- 2.87% in APR and 80.39% +/- 5.06% in SSR before 1980, and 71.65% +/- 3.28% in APR and 83.82% +/- 3.46% since 1980. The local recurrence after curative resection was 13.57% in APR and 12.33% in SSR. The data showed that in properly selected cases, the outcome was better in SSR than in APR either in survival or in quality of life. The feasibility and reasonality of the SSR and the rules for selecting the operative procedures in low rectal cancer were discussed in detail.

Female↗
PubMed1995

[Acute effect of milrinone on pulmonary hemodynamics in patients with hypoxic pulmonary hypertension].

Milrinone is a phosphodiesterase inhibitor that has vasorelaxant activity. The authors studied its effect on pulmonary haemodynamics in 12 patients with hypoxic pulmonary hypertension. After treatment with milrinone, mean pulmonary arterial pressure (from 4.61 +/- 1.41 kPa to 3.36 +/- 1.20 kPa, 1kPa = 7.5mmHg) and pulmonary vascular resistance (from 557.56 +/- 167.70 dyne.sec.cm-5 to 392.60 +/- 133. 81 dyne.sec.cm-5) decreased (P < 0.05), while cardiac output increased (from 5.11 +/- 1.62 L/min to 5.62 +/- 1.66 L/min) (P > 0.05). The systemic blood pressure (from 11.50 +/- 1.63 kPa to 10.71 +/- 1.83 kPa) and systemic vascular resistance (from 1476.64 +/- 531.52 dyne.sec.cm-5 to 1,236.49 +/- 410.18 dyne.sec.cm-5) also decreased (P > 0.05). but there was no change in arterial oxygen saturation (SaO2). The incidence of side effects were low, 4 patients developed tackycardia, and 2 patients developed ventricular premature beats. It is therefore, shown that milrinone is a potent pulmonary vasodilator.

Aged↗
PubMed1995

Mild hyperthermia can induce adaptation to cytogenetic damage caused by subsequent X irradiation.

Many low-level environmental agents are able to induce an increased resistance to subsequent mutagenic effects induced by ionizing radiation. In this paper, an induced cytogenetic adaptation to radiation in human lymphocytes was studied with mild hyperthermia as the adaptive treatment and compared with that induced by low-dose radiation. We found that this adaptation could be induced not only in PHA-stimulated human lymphocytes (at 14, 38 and 42 h after addition of PHA), but also in unstimulated G0-phase cells (before addition of PHA) by mild hyperthermia (41 degrees C for 1 h) as well as 50 mGy X rays. When the two adaptive treatments were combined, no additive effects on the magnitude of the adaptation induced were observed, suggesting that low-dose radiation and hyperthermia may share one mechanism of induction of adaptation to cytogenetic damage. Some mechanisms which may be involved in the induction of adaptation to cytogenetic damage by low-dose radiation are discussed and compared with the effects of mild hyperthermia in inducing thermotolerance and radioresistance.

Adaptation, Physiological↗
PubMed1995

[Time course of the effect of electroacupuncture on immunomodulation of normal rat].

Lymphocyte proliferation of splenocytes induced by concanavalin A (Con A) and the induction of IL-2 production test were used to study the effects of acupuncture on immunomodulation by stimulation of Zusanli (ST 36) and Lanwei (Extra 33) points of the rat's left leg. It was observed that the lymphocyte proliferation of splenocytes was increased in EA groups of 3 days (p < 0.05) 5 days (p < 0.001) and 7 days (P < 0.05). The parabolical curve could be found by currilinear regression (R2 = 0.9901). EA groups of 3 days and 5 days had a significantly increased induction of IL-2 production (P < 0.05). These results will be helpful to choose an optimal time for clinical treatment.

Animals↗
PubMed1995

[Comparative study on pharmacological effects of various species of Pueraria].

Through comparative studies on the acute toxicity of four species of Pueraria, it was found that the toxicity of P. peduncularis was the highest, followed by P. lobata and P. omeiensis, and that of P. thomsonii was the lowest. The inhibitory effects of P. lobata, P. omeiensis and puerarin on the fever induced by 2,4-dinitrophenol in rats were very fast and significant, maintaining for about 8 hours, while the effect of P. thomsonii is relatively weak. As for influence upon the degrees of myocardiac ischemia induced by pituitrin, P. omeiensis appeared to be the most potent, and P. thomsonii the least one, while P. lobata and puerarin were intermediate between the above two. Summarily, the antipyretic and anti-myocardiac ischemia effects of P. lobata and P. omeiensis are stronger than those of P. thomsonii, and puerarin is one of their effective components.

2,4-Dinitrophenol↗
PubMed1995

[Concentrations and size distributions of aerosols in middle summer of Chengdu].

Statistical concentrations and size distributions of aerosols in middle summer of Chengdu city were measured by using optical scattering method. The influence of climate and its daily change affects on the concentration and distribution were analysed. The results showed: many of the distributions agreed with the Junge distribution; the peak concentration appeared near the noon; the relative humidity had strong influence on concentration; the clean-up effect of rain fall was evident. The measured results are useful for evaluating the environmental sanitation of the city.

Air Pollutants↗
PubMed1994

Construction and characterization of a bacterial artificial chromosome library of Sorghum bicolor.

The construction of representative large insert DNA libraries is critical for the analysis of complex genomes. The predominant vector system for such work is the yeast artificial chromosome (YAC) system. Despite the success of YACs, many problems have been described including: chimerism, tedious steps in library construction and low yields of YAC insert DNA. Recently a new E.coli based system has been developed, the bacterial artificial chromosome (BAC) system, which offers many potential advantages over YACs. We tested the BAC system in plants by constructing an ordered 13,440 clone sorghum BAC library. The library has a combined average insert size, from single and double size selections, of 157 kb. Sorghum inserts of up to 315 kb were isolated and shown to be stable when grown for over 100 generations in liquid media. No chimeric clones were detected as determined by fluorescence in situ hybridization of ten BAC clones to metaphase and interphase S.bicolor nuclei. The library was screened with six sorghum probes and three maize probes and all but one sorghum probe hybridized to at least one BAC clone in the library. To facilitate chromosome walking with the BAC system, methods were developed to isolate the proximal ends of restriction fragments inserted into the BAC vector and used to isolate both the left and right ends of six randomly selected BAC clones. These results demonstrate that the S. bicolor BAC library will be useful for several physical mapping and map-based cloning applications not only in sorghum but other related cereal genomes, such as maize. Furthermore, we conclude that the BAC system is suitable for most large genome applications, is more 'user friendly' than the YAC system, and will likely lead to rapid progress in cloning biologically significant genes from plants.

Base Sequence↗
PubMed1994

Dual effects of nicardipine: evidence from intracellular Ca2+ transients and twitch contractions observed in single myocytes obtained from rat heart.

Mechanisms responsible for dual actions of nicardipine were examined using myocytes isolated from ventricular muscle of rat heart. About 60% of isolated rat myocytes showed positive force-frequency relationships. These cells had lower intracellular Ca2+ concentrations at rest. In the remaining cells that had higher resting Ca(2+)-concentrations, an increase in frequency of stimulation from 1 Hz to 2 Hz produced either no change or reduction in the amplitude of Ca2+ transients and twitch contractions. In 13 of 34 myocytes that showed positive force-frequency relationships, nicardipine enhanced the Ca2+ transient and produced sustained positive inotropic effects. In 11 of 20 cells that showed negative force-frequency relationships, nicardipine produced negative inotropic effects. Inhibition was partly reversed by an increase in extracellular CaCl2 concentration from 1.2 to 3.6 mM. In the remaining cells, nicardipine failed to either increase or decrease the amplitude of Ca2+ transient or twitch contraction. Bay K-8644 produced positive inotropic effects in most cells. These results indicate that nicardipine either enhances or inhibits Ca2+ transients and twitch contractions depending on the Ca2+ loading state of myocytes. The present results are consistent with the hypothesis that nicardipine stabilizes the state of Ca2+ channels, either in the inactivated state in cells that are well loaded with Ca2+, or in the activated state when the degree of Ca2+ loading is relatively low.

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

Low-frequency EPR detection of chromium(V) formation by chromium(VI) reduction in whole live mice.

Measurements by direct low frequency EPR spectroscopy provide the first evidence that Cr(V) is generated in one-electron reduction of Cr(VI) in live mice. The Cr(V) yield reached a maximum about 10 min following Cr(VI) intravenous injection and then decayed slowly with a life time of approximately 37 min. The time for the Cr(V) EPR signal to reach maximum intensity increased with the dose of Cr(VI). A discernible EPR signal was still observable at a dose as low as 0.1 mmol/kg. The Cr(V) was found predominantly in the liver, with a small amount in the blood. No Cr(V) signal was detectable in heart, spleen, kidney, and lung. Pretreatment of the animals with metal ion chelators, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, and 1,10-phenanthroline significantly reduced the intensity of the Cr(V) signal that was observed.

Animals↗
PubMed1994

New 18S.26S ribosomal RNA gene loci: chromosomal landmarks for the evolution of polyploid wheats.

Three new 18S.26S rRNA gene loci were identified in common wheat by sequential N-banding and in situ hybridization (ISH) analysis. Locus Nor-A7 is located at the terminal area of the long arm of 5A in both diploid and polyploid wheats. Locus Nor-B6 is located in N-band 1BL2.5 of the long arm of chromosome 1B in Triticum turgidum and Triticum aestivum. ISH sites, similar to Nor-B6, were also detected on the long arms of chromosomes 1G in Triticum timopheevii and 1S in Aegilops speltoides, but their locations on the chromosomes were different from that of Nor-B6, indicating possible chromosome rearrangements in 1GL and 1BL during evolution. The third new locus, Nor-D8, was only found on the short arm of chromosome 3D in the common wheat Wichita. The loss of rRNA gene locus Nor-A3 and gain of repetitive DNA sequence pSc119 on the terminal part of 5AS suggest a structural modification of 5AS. Comparative studies of the location of the 18S.26S rRNA gene loci in polyploid wheats and putative A and B (G) genome progenitor species support the idea that: (1) Triticum monococcum subsp. urartu is the donor of both the A and A(t) genome of polyploid wheats. (2) Ae. speltoides is closer to the B and G genome of polyploid wheats than Aegilops longissima and is the most probable progenitor of these two genomes.

Biological Evolution↗
PubMed1994

Introgression of Elymus trachycaulus chromatin into common wheat.

A number of wheat-Elymus trachycaulus (2n = 4x = 28, genomically StStHtHt) chromosome addition, substitution, and translocation lines were isolated from the derivatives of an E. trachycaulus x wheat hybrid. Eighteen out of a total of 28 chromosome arms of E. trachycaulus were recovered in the addition lines. The genomic affinity of individual E. trachycaulus chromosomes was analysed by comparative chromosome banding and in situ hybridization using genome-specific repetitive DNA sequences as probes. The homoeology of the E. trachycaulus chromosomes added to wheat was determined by storage protein, isozyme, and restriction fragment length polymorphism analysis. Alloplasmic wheat-E. trachycaulus chromosome additions were isolated which only involved chromosome 1Ht and 1St that carry fertility restoration gene Rf-Ht1 and Rf-St1, respectively. Based on the results of production and characterization of a wheat-E. trachycaulus 5Ht(5B) substitution line, it is likely that some wheat chromosomes can be well compensated genetically by E. trachycaulus chromosomes. Several spontaneous wheat-E. trachycaulus chromosome translocation lines were detected. All the translocation lines involved either 1Ht or 1St. To estimate the potential of recombination between wheat and E. trachycaulus chromosomes, a backcross population derived from a plant which was double monosomic for chromosomes 7A and 7AL.7AS-1StS and a ph1b gene was developed. The plants from this population were analysed for 1St-specific genetic markers and no recombinant was recovered.

Chromosome Banding↗
PubMed1994

Different species-specific chromosome translocations in Triticum timopheevii and T. turgidum support the diphyletic origin of polyploid wheats.

Triticum timopheevii ssp. timopheevii and T. timopheevii ssp. araraticum were analysed by sequential N-banding and genomic in situ hybridization. Three chromosomes, 6At, 1G and 4G, were involved in At-G intergenomic translocations in all six lines analysed. These chromosomes may be derived from a cyclic translocation that is species-specific to T. timopheevii. In contrast, Triticum turgidum has a species-specific cyclic translocation involving chromosomes 4A, 5A and 7B. The discovery of different species-specific chromosome translocations supports the diphyletic hypothesis of the evolution of tetraploid wheats. The results from genomic blocking analysis also revealed that the chromosomes of Aegilops speltoides are closer to the G genome than the B genome chromosomes. The possible role of species-specific translocations in the evolution of wheat is discussed.

Chromosome Banding↗