29 research outputs found
Establishing a new appropriate intramuscular injection site in the deltoid muscle
金沢大学医薬保健研究域保健学系It is becoming increasingly important for clinicians to identify a safer intramuscular (IM) injection site in the deltoid muscle because of possible complications following the vaccine administration of IM injections. We herein examined 4 original IM sites located on the perpendicular line through the mid-acromion to establish a safer IM injection site. Thirty healthy volunteers participated in this study and the distances from our 4 IM sites to some anatomical landmarks on their left arms were measured. Ultrasonography (US) was also performed to measure the thickness of the deltoid muscle and identify the posterior circumflex humeral artery (PCHA) along the course of the axillary nerve. Subcutaneous thickness was measured using 2 methods: measuring the skin thickness with caliper after pinching the skin, and with US. The results obtained revealed that the intersection between the anteroposterior axillary line (the line between the upper end of the anterior axillary line and the upper end of the posterior axillary line) and the perpendicular line from the mid-acromion was the most appropriate site for IM injections because it was distant from the axillary nerve, PCHA, and subdeltoid/subacromial brusa. At this site, depth of needle insertions was 5 mm greater than the subcutaneous thickness at a 90° angle, which was sufficient to penetrate subcutaneous tissue in both sexes. Subcutaneous thickness can be assessed with almost the same accuracy by US or measuring with calipers after pinching the skin. The results of the present study support the improved vaccine practice for safer IM injections
Photoresponsive Aqueous Dissolution of Poly(<i>N</i>‑Isopropylacrylamide) Functionalized with <i>o</i>‑Nitrobenzaldehyde through Phase Transition
We
report a sharp photoinduced aqueous dissolution of the copolymer
through phase transition based on the photochemical reaction of <i>o</i>-nitrobenzaldehyde (NBA) and the principle of polymer effect.
We synthesized the copolymers having poly(<i>N</i>-isopropylacrylamide)
main chain and NBA side chain at 4, 7, and 10 mol % functionalizations
and analyzed their photoresponsive characteristics. Light with 365
nm wavelength converted NBA groups at copolymer side chains to carboxylic
acid efficiently at the rate of 7.3 cm<sup>2</sup>/J, and in the case
of 10 mol % functionalization, the irradiation dosage no more than
56 mJ/cm<sup>2</sup> induced sharp aqueous dissolution of the copolymer
thin layer in pH 7.4 at 25 °C. As example applications, we demonstrated
on-demand release of polyethylene beads and fluorescent-labeled albumins,
which had been immobilized on a substrate surface via the copolymers,
by the precisely controlled light irradiation using a microprojection
system. Also, we examined application of the copolymers to the selective
recovery of living cells from culture substrate under microscopic
observation. As a result, mild light irradiation at room temperature
triggered immediate detachment of the cultured adherent cells only
in the irradiated areas without critical influence on their viability
Photoresponsive Aqueous Dissolution of Poly(<i>N</i>‑Isopropylacrylamide) Functionalized with <i>o</i>‑Nitrobenzaldehyde through Phase Transition
We
report a sharp photoinduced aqueous dissolution of the copolymer
through phase transition based on the photochemical reaction of <i>o</i>-nitrobenzaldehyde (NBA) and the principle of polymer effect.
We synthesized the copolymers having poly(<i>N</i>-isopropylacrylamide)
main chain and NBA side chain at 4, 7, and 10 mol % functionalizations
and analyzed their photoresponsive characteristics. Light with 365
nm wavelength converted NBA groups at copolymer side chains to carboxylic
acid efficiently at the rate of 7.3 cm<sup>2</sup>/J, and in the case
of 10 mol % functionalization, the irradiation dosage no more than
56 mJ/cm<sup>2</sup> induced sharp aqueous dissolution of the copolymer
thin layer in pH 7.4 at 25 °C. As example applications, we demonstrated
on-demand release of polyethylene beads and fluorescent-labeled albumins,
which had been immobilized on a substrate surface via the copolymers,
by the precisely controlled light irradiation using a microprojection
system. Also, we examined application of the copolymers to the selective
recovery of living cells from culture substrate under microscopic
observation. As a result, mild light irradiation at room temperature
triggered immediate detachment of the cultured adherent cells only
in the irradiated areas without critical influence on their viability
Photoresponsive Aqueous Dissolution of Poly(<i>N</i>‑Isopropylacrylamide) Functionalized with <i>o</i>‑Nitrobenzaldehyde through Phase Transition
We
report a sharp photoinduced aqueous dissolution of the copolymer
through phase transition based on the photochemical reaction of <i>o</i>-nitrobenzaldehyde (NBA) and the principle of polymer effect.
We synthesized the copolymers having poly(<i>N</i>-isopropylacrylamide)
main chain and NBA side chain at 4, 7, and 10 mol % functionalizations
and analyzed their photoresponsive characteristics. Light with 365
nm wavelength converted NBA groups at copolymer side chains to carboxylic
acid efficiently at the rate of 7.3 cm<sup>2</sup>/J, and in the case
of 10 mol % functionalization, the irradiation dosage no more than
56 mJ/cm<sup>2</sup> induced sharp aqueous dissolution of the copolymer
thin layer in pH 7.4 at 25 °C. As example applications, we demonstrated
on-demand release of polyethylene beads and fluorescent-labeled albumins,
which had been immobilized on a substrate surface via the copolymers,
by the precisely controlled light irradiation using a microprojection
system. Also, we examined application of the copolymers to the selective
recovery of living cells from culture substrate under microscopic
observation. As a result, mild light irradiation at room temperature
triggered immediate detachment of the cultured adherent cells only
in the irradiated areas without critical influence on their viability
Establishing a new appropriate intramuscular injection site in the deltoid muscle
It is becoming increasingly important for clinicians to identify a safer intramuscular (IM) injection site in the deltoid muscle because of possible complications following the vaccine administration of IM injections. We herein examined 4 original IM sites located on the perpendicular line through the mid-acromion to establish a safer IM injection site. Thirty healthy volunteers participated in this study and the distances from our 4 IM sites to some anatomical landmarks on their left arms were measured. Ultrasonography (US) was also performed to measure the thickness of the deltoid muscle and identify the posterior circumflex humeral artery (PCHA) along the course of the axillary nerve. Subcutaneous thickness was measured using 2 methods: measuring the skin thickness with caliper after pinching the skin, and with US. The results obtained revealed that the intersection between the anteroposterior axillary line (the line between the upper end of the anterior axillary line and the upper end of the posterior axillary line) and the perpendicular line from the mid-acromion was the most appropriate site for IM injections because it was distant from the axillary nerve, PCHA, and subdeltoid/subacromial brusa. At this site, depth of needle insertions was 5 mm greater than the subcutaneous thickness at a 90° angle, which was sufficient to penetrate subcutaneous tissue in both sexes. Subcutaneous thickness can be assessed with almost the same accuracy by US or measuring with calipers after pinching the skin. The results of the present study support the improved vaccine practice for safer IM injections
Macrophage-dependent clearance of systemically administered B16BL6-derived exosomes from the blood circulation in mice
Previous studies using B16BL6-derived exosomes labelled with gLuc–lactadherin (gLuc-LA), a fusion protein of Gaussia luciferase (a reporter protein) and lactadherin (an exosome-tropic protein), showed that the exosomes quickly disappeared from the systemic circulation after intravenous injection in mice. In the present study, the mechanism of rapid clearance of intravenously injected B16BL6 exosomes was investigated. gLuc-LA-labelled exosomes were obtained from supernatant of B16BL6 cells after transfection with a plasmid DNA encoding gLuc-LA. Labelling was stable when the exosomes were incubated in serum. By using B16BL6 exosomes labelled with PKH26, a lipophilic fluorescent dye, it was demonstrated that PKH26-labelled B16BL6 exosomes were taken up by macrophages in the liver and spleen but not in the lung, while PKH26-labelled exosomes were taken up by the endothelial cells in the lung. Subsequently, gLuc-LA-labelled B16BL6 exosomes were injected into macrophage-depleted mice prepared by injection with clodronate-containing liposomes. The clearance of the intravenously injected B16BL6 exosomes from the blood circulation was much slower in macrophage-depleted mice than that in untreated mice. These results indicate that macrophages play important roles in the clearance of intravenously injected B16BL6 exosomes from the systemic circulation