No abstract available.
Animals ; Mice* ; Microinjections* ; Zygote*

Microneedles have been developed rapidly in the field of transdermal administration in the past few decades. In recent years, the development of microelectronics technology has expanded the applications of microneedles by combining with microelectronic systems, especially in biological diagnosis and treatment. Different types of microneedles have been designed to extract blood and tissue fluids for detection, or as electrodes to directly detect blood sugar, melanoma and pH in real-time in vivo, both show good prospects for real-time detection applications. In this paper, we review the design of materials and structure of microelectronic-based microneedles, and discuss their advances in biological diagnosis.
Administration, Cutaneous ; Drug Delivery Systems ; Electrodes ; Microinjections ; Needles

To determine the role of dopamine D2 receptor (D2R) in the nucleus accumbens (NAc) core in cocaine-induced behavioral sensitization, D2R antagonist, raclopride was bilaterally microinjected (2.5 or 5 nmol) into the NAc core of WT and D2R-/- mice and the initiation and expression phase of cocaine-mediated locomotor sensitization were analyzed. WT and D2R knockout (D2R-/-) mice received bilateral injections of either saline, or raclopride at the NAc core 30 min before each of five daily repeated injections of saline or cocaine (15 mg/kg i.p.). Following 2 weeks of withdrawal after repeated exposure to cocaine, the animals were pre-treated with an intra-accumbal injection of vehicle or raclopride before receiving a systemic cocaine challenge for the expression of sensitization. Animals which had been microinjected raclopride into NAc core displayed the enhancement of cocaine-induced behavioral response for the initiation but also for the expression of sensitization in WT as well as in D2R-/- mice, which was thus unaltered as compared to vehicle-injected control group. These results suggest that D2R in NAc core is not involved in cocaine-induced behavioral sensitization.
Animals ; Cocaine ; Dopamine ; Mice ; Microinjections ; Nucleus Accumbens ; Raclopride ; Receptors, Dopamine ; Receptors, Dopamine D2

The hypothalamic paraventricular nucleus (PVN) is a central site for integration of the endocrine system and the autonomic nervous system. Despite a number of studies have pointed out the importance of the PVN in the central regulation of cardiovascular functions, the chemical mediators in the PVN responsible for mediating baroreflex are not well understood. In the present study, we used the conscious rats to investigate the possible involvement of glycine (Gly) in PVN in the central regulation of baroreflex induced by intravenous injection of phenylephrine (0.8 mug/0.04 mL, in 3 min). Then, the microdialysis sampling was performed in the PVN and the concentration of Gly in the microdialysate was measured by high performance liquid chromatography (HPLC) combined with electrochemical techniques, and mean arterial pressure (MAP) and heart rate (HR) were recorded simultaneously. Injection of phenylephrine elicited a significant increase (P<0.01) in MAP from the baseline of (99.5+/-14.2) mmHg to the maximum of (149.8+/-19.5) mmHg and a decrease (P<0.01) in HR from the baseline of (400.8+/-33.1) beats/min to the minimum of (273.4+/-40.8) beats/min, respectively. Synchronously, the injection of phenylephrine increased the level of Gly in the microdialysate from the PVN to (162.9+/-27.3)% of the basal level (P<0.05). Perfusion of strychnine (100 mumol/L), an antagonist of Gly receptor, into the PVN enhanced the pressor response and attenuated the bradycardic response during the baroreflex, resulting in a decrease in baroreflex sensitivity (P<0.001). Whereas, the perfusion of Gly (1 mmol/L) into the PVN did not affect the pressor response but enhanced the bradycardic response during the baroreflex, resulting in an increase in baroreflex sensitivity (P<0.001). These results suggest that endogenous Gly in the PVN may act via strychnine-sensitive Gly receptor to produce a facilitative effect on baroreflex.
Animals ; Baroreflex ; drug effects ; Glycine ; pharmacology ; Heart Rate ; Microinjections ; Paraventricular Hypothalamic Nucleus ; physiology ; Phenylephrine ; pharmacology ; Rats

BACKGROUND: Microinjectors have been used for cell biology and development, and are useful for the study of cellular morphologic changes with response to the external milieu and intracellularly injected molecules. METHODS: This study was performed to confirm the apoptotic changes induced by intracytoplasmic microinjection of cytochrome c (5 mg/mL) to mouse 3T3 fibroblasts with and without pretreatment of Ac-DEVD-CHO (100 mol/mL), and BSA (bovine serum albumin, 5 mg/mL) as a control, and evaluate the usefulness of microinjection as a method to study apoptosis pathways. RESULTS: Mild focal cytoplasmic fragmentation was seen in the cells microinjected with cytochrome c as early as 10 min after the injection. Apoptotic morphology with apoptotic body formation was observed at 60 min after the injection, and then new apoptotic change of the injected cells was not seen. Cytochrome c-injected cells showed about 31% of apoptotic cells of the total injected cells 50-60 min after the injection. BSA-injected cells did not show apoptosis morphology at 50-60 min after the injections. Caspase-3 inhibitor, Ac-DEVD-CHO-treated cells with cytochrome c microinjection exhibited lower apoptosis indices (average apoptosis index; 11.5+/-8.6%) than non-treated cells of the inhibitor (average apoptosis index; 11.5+/-8.6%). CONCLUSIONS: It was observed that intracellular microinjection of cytochromic c induced apoptosis which was inhibited by Ac-DEVD-CHO, although apoptotic cells were so easily detached that further study could not be performed. However it is thought that microinjection should be a method to study apoptosis and signal transduction with the molecular biological techniques currently available.
Animals ; Apoptosis* ; Caspase 3 ; Cytochromes c* ; Cytochromes* ; Cytoplasm ; Fibroblasts* ; Mice* ; Microinjections* ; Serum Albumin ; Signal Transduction

OBJECTIVETo establish homozygous transgenic mouse strain expressing human tau isoform with P301L mutation.

METHODSFive transgenic mice expressing human tau isoform with P301L mutation were obtained by microinjection into male nuclei. Homozygote and hemizygote were identified by PCR and real-time fluorescent quantitative PCR.

RESULTSNinety five homozygous transgenic mice were selected, and the results indicated that homozygous transgenic mice were superior to hemizygote in simulating the changes of biological characteristics.

CONCLUSIONExogenous gene tau is able to stably transmit to next generation and the combination of SYBR Green real-time fluorescent quantitative PCR with the traditional mating is a fast, reliable and economical way to screen homozygous and hemizygous transgenic mice.

Animals ; Female ; Homozygote ; Humans ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Transgenic ; Microinjections ; Mutation ; tau Proteins ; genetics

Microneedles array based on micro electro-mechanical system (MEMS) technology is one of important applications in biomedicine and brings a new means in biomedicine field. The prospect for the development of microneedles technology in precision drug injection, clinical monitoring and biochemistry test is and save broad. This paper describes three important applications of MEMS microneedles array in biomedicine field: biomedicine microneedles electrode, transdermal delivery of drugs and fluid extraction, and then summarizes their application elements and recent development. It explains the characteristics of microneedles, which provide painless, effective and save biomedical method in accordance with human requirements. In addition, a series of the fabrication technology of microneedles array is discussed.
Drug Delivery Systems ; instrumentation ; Equipment Design ; Humans ; Microelectrodes ; Microinjections ; instrumentation ; Miniaturization ; Nanotechnology ; Needles

BACKGROUND: Stabilized hyaluronic acid (S-HA) is used for soft tissue augmentation and can also be used for dermal hydration. According to previous reports, the injection volume of each shot is more than 0.02 cc for dermal hydration. Clinically, this is an excessive amount for this purpose, so I will introduce a modified method using particle type S-HA injection for dermal hydration. METHODS: One hundred fifty patients who had 1,000 injections of 1 cc S-HA by injector were analyzed. The patients were examined after 1, 2, 6, 12, and 24 months. Changes in skin texture were determined with regard to skin roughness and morphology, dermal hydration by electric resistance, dermal thickness by ultrasonic imaging, and biopsy. An intra-individual study was also performed to compare changes in skin texture between dermal and subdermal injections. RESULTS: Skin roughness significantly improved after this procedure. Electric resistance also decreased. The dermis of the face and hand were thickened about 4% after dermal injection. The injection depth was confirmed by biopsy. There were no significant changes in dermal thickness after subdermal injection with S-HA, which merely replaced fluid volume. Injections into the dermis changed both skin texture and thickness. CONCLUSIONS: Skin texture was improved after 1000 dermal injections (0.001 cc each) of particle type S-HA. Deeper injections only replaced the fluid volume and could not improve skin texture. For this purpose, the use of an injector or mesogun is recommended.
Biopsy ; Dermis* ; Electric Impedance ; Hand ; Humans ; Hyaluronic Acid* ; Hypodermoclysis ; Injections, Intradermal ; Microinjections ; Skin* ; Ultrasonography

It is very important to disrupt the stratum corneum structure and to create pathways allowing transport of macromolecules, as the traditional transdermal drug delivery has been severely limited by the skin barrier. With the development of the Micro Electro-Mechanical System (MEMS), it becomes possible for microneedles array to strengthen the transdermal drug delivery. In addition to the increase of the skin permeability, it can also be used to deliver drugs into skin, such as insulin and vaccine, providing a new direction for drug delivery systems. In this paper, we review the development and applications in transdermal drug delivery of microneedles' array. The commercial prospects and recommendations for the future research work are also represented.
Administration, Cutaneous ; Drug Delivery Systems ; instrumentation ; Equipment Design ; Micro-Electrical-Mechanical Systems ; Microinjections ; Needles

Neuro-tracing approach is a great option to study innervation of the visceral organs including the kidneys. Important factors contributing to the success of this technique include the choice of a neuro-tracer, and delivery methods to result in successful labeling of peripheral sensory and motor ganglia. The neuro-tracer is usually applied directly to the kidney accessed via a surgical opening of the abdominal wall under deep anesthesia. A series of local microinjections of the dye are performed followed by a wound closure, and recovery period from the surgery. An extra care should be taken to prevent neuro-tracer spillage and accidental labeling of the surrounding organs during injections of the dye. Retrograde neuro-tracers like Fast Blue do not cross synapses, therefore, only neuronal bodies located within dorsal root ganglion neurons and major peripheral ganglia will be labeled by this approach. Retrogradely labeled peripheral neurons could be freshly isolated and dissociated for electrophysiological recordings and biochemical analyses (gene and protein expression), whereas the whole fixed ganglia could be sectioned to undergo immunohisto- and immunocytochemical targeted staining.
Abdominal Wall ; Anesthesia ; Ganglia ; Ganglia, Spinal ; Kidney* ; Microinjections ; Neurons ; Synapses ; Wounds and Injuries