蛋白激酶C不参与在无钙溶液内高钾引起的血管收缩

蛋白激酶Ｃ不参与在无钙溶液内高钾引起的血管收缩关超然２，ＧｅｎｎａｄｉＭＫＲＡＶＴＳＯＶ（ＤｅｐａｒｔｍｅｎｔｏｆＰｈｙｓｉｏｌｏｇｙ，ＦａｃｕｌｔｙｏｆＭｅｄｉｃｉｎｅ，ＴｈｅＵｎｉｖｅｒｓｉｔｙｏｆＨｏｎｇＫｏｎｇ，ＨｏｎｇＫｏｎｇ）关键词钙；蛋...     

Pseudomonas Septicaemia in Apparently Healthy Children

ABSTRACT. Among 27 cases of Pseudomonas septicaemia in the Department of Paediatrics of Queen Mary Hospital from 1981 to 1988, we have identified 10 children without known predisposing causes before presentation and report their clinical features. Six were infants, of whom 4 developed shock on admission and died. Ecthyma gangrenosum was present in 4 patients. Pesudomonas aeruginosa was isolated in 8 patients. All isolates, except Ps. cepacia , were sensitive to gentamicin. One patient had cyclical neutropenia. Another had an appendicular abscess. Salmonella was cultured from the stool in one patient. Although Pseudomonas septicaemia is normally considered to be associated with underlying immunodeficiency, in 22% it occurred in previously healthy children. Mortality is high especially in infants who develop septicaemic shock. It is advisable to cover for Pseudomonas septicaemia with aminoglycosides or ceftazidime in sick septic infants.     

Use of a Long-Pulse Alexandrite Laser in the Treatment of Superficial Pigmented Lesions

BACKGROUND/OBJECTIVE Although the alexandrite 755-nm-wavelength laser is effective in the treatment of unwanted hair, there are no published studies gauging the efficacy of the variable long-pulse alexandrite laser in the treatment of superficial pigmented lesions.
STUDY DESIGN/METHODS Eighteen patients underwent a single treatment session using a variable pulse-width alexandrite laser. Test sites were performed using a 10-mm spot size and up to four pulse widths (3, 20, 40, 60 ms) with and without epidermal cooling. Full treatments were performed 3 weeks later using optimum test parameters. The patients were evaluated at 3 and 6 weeks.
RESULTS Patients with darker lentigines had greater lesion clearance than those patients with lighter colored lentigines. Shorter pulse widths and treatment without cryogen cooling both, independently, lowered the fluence threshold for lentigo clearance.
CONCLUSION A long-pulse alexandrite laser is effective in clearing solar lentigines in a single pass with minimal adverse effects.     

LSCM观察三七总皂甙及其组分对游离钙离子影像变化的影响

用盖玻片或ＭａｔＴｅｋ培养皿培养猪主动脉内皮细胞（ａＥＣ）约１８ｈ后，以荧光探针（ｆｌｕｏ－３／ＡＭ终浓度１０μｍｏｌ·Ｌ－１）负载，当细胞内游离钙离子（Ｃａ２＋）与ｆｌｕｏ－３结合后，通过激光扫描共聚焦显微镜（ＩｎＳＩＧＨＴ－ｐｌｕｓＩＱ型）观察细胞的荧光影像变化。基于三七总皂甙（ｔ－ＰＮＳ）对ａＥＣ所产生的生物活性物质有明显的作用，本拟进一步探索上述药物对ａＥＣ中［Ｃａ２＋］；的影响。实验结果显示：在ＡＴＰ作用后，ｔ－ＰＮＳ可使ａＥＣ内的荧光强度在２０～８０ｓ内急剧升高至峰值。但其组分Ｒｂ１及Ｒｇ１使荧光强度有下降或无明显变化。提示ｔ－ＰＮＳ有使内皮细胞［Ｃａ２＋］；升高的作用。     

Vascular effects of Siberian ginseng (<Emphasis Type="Italic">Eleutherococcus senticosus</Emphasis>): endothelium-dependent NO- and EDHF-mediated relaxation depending on vessel size

Siberian ginseng (SG) has been widely and historically consumed as a health food product for the improvement of self well-being, but whether vascular relaxation may contribute to such a therapeutic health effect has not been studied. We therefore investigated the vasorelaxant effect of the aqueous extract of the roots of SG (Eleutherococcus senticosus Maxim) using several in vitro vascular rings prepared from dog carotid artery, rat aorta and rat mesenteric artery. SG extract (0.04–0.8 mg/ml) caused concentration-dependent relaxation in dog carotid arterial rings pre-contracted with 100 M phenylephrine (PE), and the relaxation was primarily endothelium-dependent. Treatment with 100 M L-NOARG (a nitric oxide synthase inhibitor) either prevented or totally reverted SG-induced relaxation, suggesting that the endothelium-dependent relaxation was mediated by NO. Similar endothelium-dependent vascular relaxant responses were also obtained with rat aortic and mesenteric arterial rings, except that it occurred over a relatively higher concentration range of SG (0.5–2.0 mg/ml). When tested in the presence of 300 M L-NAME, the vasorelaxant effect of SG was inhibited totally in rat aorta but only partially in rat mesenteric artery. The relaxation to SG that was insensitive to L-NAME in rat mesenteric arterial rings was eliminated when the rings (both proximal and distal ends) were pre-treated with a combination of 300 M L-NAME and 15 mM KCl indicating the involvement of endothelium-derived hyperpolarizing factor (EDHF). This vasorelaxant response of the SG extract was inhibited partially by atropine (1 M), completely by TEA (5 mM), but not by indomethacin (1 M) or propranolol (10 M). SG up to 2 mg/ml had no effect on KCl-induced contraction in any of the vascular rings studied. When compared with carbachol-induced (CCh) relaxation, SG resembles CCh in that the sensitivity to L-NAME inhibition is dependent on vascular size, i.e. aorta >proximal end of mesenteric artery >distal end of mesenteric artery. However, SG exhibited different potencies to relaxation while CCh showed similar potency (EC₅₀ of about 0.2 M) in all three vascular segments. In conclusion, we have demonstrated that the vascular effect of SG is endothelium-dependent and mediated by NO and/or EDHF depending on the vessel size. Other vasorelaxation pathways, such as inhibition of K⁺-channels and activation of muscarinic receptors, may also be involved.     

Nitric oxide,human diseases and the herbal products that affect the nitric oxide signalling pathway

1. Nitric oxide (NO) is formed enzymatically from l-arginine in the presence of nitric oxide synthase (NOS). Nitric oxide is generated constitutively in endothelial cells via sheer stress and blood-borne substances. Nitric oxide is also generated constitutively in neuronal cells and serves as a neurotransmitter and neuromodulator in non-adrenergic, non-cholinergic nerve endings. Furthermore, NO can also be formed via enzyme induction in many tissues in the presence of cytokines. 2. The ubiquitous presence of NO in the living body suggests that NO plays an important role in the maintenance of health. Being a free radical with vasodilatory properties, NO exerts dual effects on tissues and cells in various biological systems. At low concentrations, NO can dilate the blood vessels and improve the circulation, but at high concentrations it can cause circulatory shock and induce cell death. Thus, diseases can arise in the presence of the extreme ends of the physiological concentrations of NO. 3. The NO signalling pathway has, in recent years, become a target for new drug development. The high level of flavonoids, catechins, tannins and other polyphenolic compounds present in vegetables, fruits, soy, tea and even red wine (from grapes) is believed to contribute to their beneficial health effects. Some of these compounds induce NO formation from the endothelial cells to improve circulation and some suppress the induction of inducible NOS in inflammation and infection. 4. Many botanical medicinal herbs and drugs derived from these herbs have been shown to have effects on the NO signalling pathway. For example, the saponins from ginseng, ginsenosides, have been shown to relax blood vessels (probably contributing to the antifatigue and blood pressure-lowering effects of ginseng) and corpus cavernosum (thus, for the treatment of men suffering from erectile dysfunction; however, the legendary aphrodisiac effect of ginseng may be an overstatement). Many plant extracts or purified drugs derived from Chinese medicinal herbs with proposed actions on NO pathways are also reviewed.     

血管内皮细胞中细胞钙的动态数字荧光率影像(英文)

AIM: To study the spatial and temporal distribution of intracellular Ca2 concentration in cultured bovine pulmonary artery endothelial ( BPAE ) cells. METHODS: Cultured BPAE cells were loaded with Fura-2 and observed under an inverted microscope coupled to a microfluorimeter, which enables pixel-to-pixel ratio imaging of the BPAE cells in real time. RESULTS: Addition of Ca2 1-2 mmol·L-1 to BPAE cells, which were exposed to Ca2 -fiee medium containing egtazic acid, resulted in a transient elevation of cytosolic Ca2 concentration, which rapidly returned to the resting level. Biphasic elevation (a larger transient phase followed by a smaller sustained phase) of intracellular Ca2 concentration was observed upon the addition of ATP (via activation of surface membrane receptor). 4-Chloro-3-ethyl phenol (CEP; an activator of Ca2 -induced Ca2 channels) potently induced elevation of Ca2 level. Cyclopiazonic acid (CPA; an inhibitor of endoplasmic reticulum Ca2 -ATPase pump) offered a more sustained eleva     

Penicillium marneffei infection in a non-HIV infected child

We report a case of Penicillium marneffei infection in a previously healthy 3.5 years-old Chinese boy and review the literature. The details of the case are described with emphasis on his immune function and treatment outcome. This boy had transient immunodeficiency involving phagocytic and NK cells due to P. marneffei infection which resolved after treatment with gamma interferon and amphotericin B. A prolonged course of fluconazole of 1 year was successful in preventing relapse. Gamma interferon, amphotericin B and a prolonged course of fluconazole may be useful in the treatment of life-threatening infection by P. marneffei.