Biomedical subjects
A Meng
Publications and source records attributed to A Meng.
Modification of bacterial artificial chromosomes through chi-stimulated homologous recombination and its application in zebrafish transgenesis.
The modification of yeast artificial chromosomes through homologous recombination has become a useful genetic tool for studying gene function and enhancer/promoter activity. However, it is difficult to purify intact yeast artificial chromosome DNA at a concentration sufficient for many applications. Bacterial artificial chromosomes (BACs) are vectors that can accommodate large DNA fragments and can easily be purified as plasmid DNA. We report herein a simple procedure for modifying BACs through homologous recombination using a targeting construct containing properly situated Chi sites. To demonstrate a usage for this technique, we modified BAC clones containing the zebrafish GATA-2 genomic locus by replacing the first coding exon with the green fluorescent protein (GFP) reporter gene. Molecular analyses confirmed that the modification occurred without additional deletions or rearrangements of the BACs. Microinjection demonstrated that GATA-2 expression patterns can be recapitulated in living zebrafish embryos by using these GFP-modified GATA-2 BACs. Embryos microinjected with the modified BAC clones were less mosaic and had improved GFP expression in hematopoietic progenitor cells compared with smaller plasmid constructs. The precise modification of BACs through Chi-stimulated homologous recombination should be useful for studying gene function and regulation in cultured cells or organisms where gene transfer is applicable.
[Acupuncture therapy with TENS in chronic pain at the Neurologic Pain-Acupuncture Ambulatory Care Clinic of the Vienna Lainz Hospital].
TENS therapy represents a good completion of chronic pain treatment, prolonging the effects of acupuncture and helping to overcome therapy resistance. Application for patients who are under Warfarin treatment and anxious of needles is obvious. Under the careful control of physicians TENS therapy is harmless. This report should be stimulating and enlarge knowledge of physicians specialized on pain treatment.
Promoter analysis in living zebrafish embryos identifies a cis-acting motif required for neuronal expression of GATA-2.
We have used zebrafish embryos to dissect the promoter activity of a gene with a complex expression pattern during embryogenesis. GATA-2 is a transcription factor required for hematopoiesis and is dynamically expressed in hematopoietic tissues and in the central nervous system. Using constructs containing zebrafish GATA-2 genomic flanking sequences and the green fluorescent protein (GFP) reporter gene, we demonstrate that distinct regulatory domains are required for hematopoietic, enveloping layer (EVL), and neuronal expression of GATA-2. During gastrulation, GFP expression is confined to the ventral ectoderm and lateral mesoderm and is lacking in the dorsal shield. Cells derived from the regions expressing GFP give rise to hematopoietic progenitors, EVL cells, and neurons. Deletion analysis of the 7.3-kb GATA-2 promoter region revealed that a 1.1-kb DNA sequence is critical for expression of GATA-2 in neurons. Fine mapping revealed that a 31-bp region is required for neuron enhancer activity, and mutagenesis showed that the DNA motif CCCTCCT is essential for GATA-2 promoter activity in the central nervous system of zebrafish. Our use of zebrafish embryos can be exploited as a whole animal system for the dissection of any developmentally regulated vertebrate promoter.
GATA-1 expression pattern can be recapitulated in living transgenic zebrafish using GFP reporter gene.
In this study, DNA constructs containing the putative zebrafish promoter sequences of GATA-1, an erythroid-specific transcription factor, and the green fluorescent protein reporter gene, were microinjected into single-cell zebrafish embryos. Erythroid-specific activity of the GATA-1 promoter was observed in living embryos during early development. Fluorescent circulating blood cells were detected in microinjected embryos 24 hours after fertilization and were still present in 2-month-old fish. Germline transgenic fish obtained from the injected founders continued to express green fluorescent protein in erythroid cells in the F1 and F2 generations. The green fluorescent protein expression patterns in transgenic fish were consistent with the pattern of GATA-1 mRNA expression detected by RNA in situ hybridization. These transgenic fish have allowed us to isolate, by fluorescence-activated cell sorting, the earliest erythroid progenitor cells from developing embryos for in vitro studies. By generating transgenic fish using constructs containing other zebrafish promoters and green fluorescent protein reporter gene, it should be possible to visualize the origin and migration of any lineage-specific progenitor cells in a living embryo.
On-line buffer removal and fraction selection in gradient capillary high-performance liquid chromatography prior to electrospray mass spectrometry of peptides and proteins.
The technique for on-line removal of buffers and for fraction selection to eliminate source clogging and suppression of electrospray ionization by unwanted constituents consisted of: (i) selecting the initial mobile phase composition to retain analytes on top of a capillary high-performance liquid chromatography (HPLC) column; (ii) washing the buffer isocratically to waste, using a two-way micro dump valve; (iii) starting the gradient and switching the dump valve to introduce analytes into the source. Peptide and protein mixtures were prepared in 0.05-0.5 M phosphate and 0.55 mM tris-based buffers, and water. After buffer removal, chromatograms and electrospray spectra were indistinguishable from those of aqueous controls, down to 1 pmol (acidic fibroblast growth factor) consumed, and up to 78 kDa (bovine transferrin) molecular weight. Aided by the dump valve, 100 fmol of angiotensin could be fractionated and identified on the slope of a 10 x 10(6) fmol of leucine enkephalin HPLC peak. On-line buffer removal and fraction selection eliminate the need for additional preparation steps than can lead to excessive sample losses.
Simplified downward alkaline transfer of DNA.
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[Treatment of whiplash injuries of the cervical spine with acupuncture].
30 patients with whiplash injuries were treated with aural-acupuncture. The points were chosen according to a special programme. Acupuncture proved an effective form of therapy for treatment of accident patients with whiplash injuries, representing a valuable supplement to the field of rehabilitation.
[The effect of standardized acupuncture programs in the after-care of accident patients].
153 patients suffering from pain, edematous conditions, and impaired movement following traumas sustained in accidents were treated or after-treated with acupuncture. Acupuncture was applied in adherence to a standardized program according to the individual types of injury. The stimulus was applied by means of steel needles inserted into body as well as ear acupuncture points. In all 9 groups, improvement of the painful condition was significant to highly significant as it was regarding improvement of the movement impairment, the latter not having been emphasized in the other 3 groups. Remaining complaints of long standing following accident traumas could also be positively influenced. Acupuncture proved itself to be an effective form of therapy for after-treatment of accident patients, presenting a valuable supplement to the field of rehabilitation, especially when combined with other physical therapeutic measures.
[Use of various forms of acupuncture and therapy with local anesthetics in accident surgery after care].
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[Testing the effect of acupuncture in accident patients using skin temperature measurements].
Skin temperature was studied on a group of 54 patients suffering from accident traumas and 20 healthy probands during and after treatment. In all patients there was a very significant rise in skin temperature in the area of the lesion which persisted beyond the treatment period, and in some cases even increased. This effect was also observed to a lesser extent on the contralateral, untreated extremity. No change in skin temperature was observed in the healthy probands who were treated in the same manner. This leads to the conclusion that needle stimuli in the area of lesions have not only a local, hyperemic effect, but also demonstrate superregional actions; this is, however, dependent on the integrity of the organism.
Preparation for hospitalization: a stress inoculation training program for parents and children.
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The black mink (Mustela vison). A natural model of immunologic male infertility.
Breeding for fine black fur has generated a colony of mink wherein 20-30% of the males are infertile. Two clinical groups are distinguishable: one being infertile from the start (primary infertility), and the other infertile after one or more years of fertility (secondary fertility). Although the etiology of primary infertility is unknown, the available data indicate that secondary infertility is associated with an autoimmune disease of the testis. Thus, male mink with secondary infertility have (a) higher prevalence and levels of anti-sperm antibody when compared with animals with primary infertility, and the antibody prevalence varies with fur color; (b) severe monocytic orchitis (47%) and/or aspermatogenesis (75%) with negative cultures for bacterial, fungal, mumps, or Coxsackie B viral organisms; (c) massive and extensive granular deposits of mink IgG and/or C3 (71%), typical of immune complexes, along the basal lamina of seminiferous tubules; (d) testes that when eluted with buffer or low pH yielded IgG that was 10-fold enriched in anti-sperm antibody activity as compared with serum IgG; and (e) no immunopathologic evidence of Aleutian mink disease. Although the sperm antigen-antibody complexes in the testis may be important as a pathogenetic mechanism of the testicular disease, there is no correlation between fluorescent anti-sperm antibody detection in the serum and the infertile state. The infertile black mink is a new model of infertility associated with naturally occurring autoimmune disease of the testis.
The hospitalized child with asthma.
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Lessons from an evaluation of the effectiveness of an asthma day camp.
PURPOSE: To evaluate the effectiveness of applied teaching methodologies in a camp setting on asthma self-management skills in school-age children. DESIGN: This was a descriptive pilot study using a one-group pretest-posttest design. SAMPLE: Thirty-four subjects, ages 6 to 12 years, representing a typical clinical population of children with asthma. METHODS: Children's asthma knowledge, symptoms, behavior, and mastery, as well as peak-flow technique, were measured 2 to 3 weeks before camp and then again on the last day of camp. Baseline measures of parents' asthma knowledge and family stress related to asthma were obtained. Outcomes specific to asthma management, such as missed school days, emergency room visits, and hospitalizations, were evaluated by parent report the year before and after the intervention. RESULTS: Significant improvement in peak-flow technique and a reported reduction in emergency room visits and missed school days after camp were found. CLINICAL IMPLICATIONS: In this pilot study, the use of an applied teaching format for school-age children in an asthma day camp resulted in some learning. More rigorous design and instrumentation are important for better evaluation of programs such as this. Nurses working with these populations should plan structured evaluations of the programs so they can best meet the children's needs.
Continuing education for advanced nurse practitioners: preparing nurse-midwives as clinical preceptors.
Nurses in advance practice roles are increasingly being sought as clinical preceptors for master's students. These nurses have variable experience as clinical teachers. A program was designed to prepare Certified Nurse-Midwives as clinical preceptors for students enrolled in a master's-level nurse-midwifery program. The program focused on techniques to foster clinical decision making, feedback, evaluation, and learning styles. Evaluations were positive and reflected that preceptors benefited from filmed modeling simulations and case study analyses.
Preceptor development. An opportunity to stimulate critical thinking.
In this article, the authors describe a preceptor development program with several unique features. The program provides preceptors with strategies to promote critical thinking and has expanded content on feedback and evaluation processes. Ongoing professional development is continued through follow-up seminars. These seminars provided preceptors with an opportunity to share their experiences, which led to identification of important issues for further exploration. For example, preceptors need assistance developing teaching strategies to meet the needs of the middle-aged new graduate nurse.