SARS: ventilatory and intensive care

Severe acute respiratory syndrome (SARS) is an emerging infection caused by a novel coronavirus. It is characterised by a highly infectious syndrome of fever and respiratory symptoms, and is usually associated with bilateral lung infiltrates. The clinical syndrome of SARS often progresses to varying degrees of respiratory failure, with about 20% of patients requiring intensive care. Despite concern about potential aerosol generation, non-invasive ventilation (NIV) has been reported to be efficacious in the treatment of SARS-related ARF without posing infection risks to health care workers (HCW). Spontaneous pneumomediastinum and pneumothorax in SARS is common. The incidence of NIV-associated barotrauma ranged from 6.6% to 15%. Patients who fail to tolerate NIV or fail NIV with progressive dyspnoea, tachypnoea and hypoxaemia should be intubated and mechanically ventilated. Mortality rates in intensive care units for SARS patients were high: 34–53% at 28 days, when some patients were still being ventilated. Strict adherence to infection control measures including isolation, use of appropriate personal protective equipment and negative pressure environment had been reported to eliminate cross-infection to HCW.     

Infection of human T-cell leukemia virus type I and development of human T-cell leukemia lymphoma in patients with hematologic neoplasms: a possible linkage to blood transfusion

Among 354 adult patients with either hematological malignancy or aplastic anemia, eight were positive for anti-HTLV-I antibodies; six of eight had received multiple transfusions. There was an approximately 3.5-fold increase (P less than .001) of HTLV-I seropositivity in the patients with hematologic disease (8 of 354, 2.23%) compared to the healthy adults older than 20 years (34 of 5252, .65%). Two hematological patients, one with Hodgkin's disease and one with acute promyelocytic leukemia, were found to be positive for HTLV-I, and developed and died of adult T-cell leukemia/lymphoma (ATL) subsequently. Both were long-term survivors of the primary disease and had received multiple transfusions. The latent period from blood transfusion to onset of ATL was 6 months and 11 years, respectively. Immunocompromised patients, who were seropositive for HTLV-I, may be at increased risk for ATL compared to healthy carriers of HTLV-I, and the latent period may be shorter.     

A murine model of neurofibromatosis type 1 tibial pseudarthrosis featuring proliferative fibrous tissue and osteoclast‐like cells

Neurofibromatosis type 1 (NF1) is a common genetic condition caused by mutations in the NF1 gene. Patients often suffer from tissue‐specific lesions associated with local double‐inactivation of NF1. In this study, we generated a novel fracture model to investigate the mechanism underlying congenital pseudarthrosis of the tibia (CPT) associated with NF1. We used a Cre‐expressing adenovirus (AdCre) to inactivate Nf1 in vitro in cultured osteoprogenitors and osteoblasts, and in vivo in the fracture callus of Nf1^flox/flox and Nf1^flox/? mice. The effects of the presence of Nf1^null cells were extensively examined. Cultured Nf1^null‐committed osteoprogenitors from neonatal calvaria failed to differentiate and express mature osteoblastic markers, even with recombinant bone morphogenetic protein‐2 (rhBMP‐2) treatment. Similarly, Nf1^null‐inducible osteoprogenitors obtained from Nf1 mouse muscle were also unresponsive to rhBMP‐2. In both closed and open fracture models in Nf1^flox/flox and Nf1^flox/? mice, local AdCre injection significantly impaired bone healing, with fracture union being <50% that of wild type controls. No significant difference was seen between Nf1^flox/flox and Nf1^flox/? mice. Histological analyses showed invasion of the Nf1^null fractures by fibrous and highly proliferative tissue. Mean amounts of fibrous tissue were increased upward of 10‐fold in Nf1^null fractures and bromodeoxyuridine (BrdU) staining in closed fractures showed increased numbers of proliferating cells. In Nf1^null fractures, tartrate‐resistant acid phosphatase–positive (TRAP+) cells were frequently observed within the fibrous tissue, not lining a bone surface. In summary, we report that local Nf1 deletion in a fracture callus is sufficient to impair bony union and recapitulate histological features of clinical CPT. Cell culture findings support the concept that Nf1 double inactivation impairs early osteoblastic differentiation. This model provides valuable insight into the pathobiology of the disease, and will be helpful for trialing therapeutic compounds. © 2012 American Society for Bone and Mineral Research     

长鞭红景天化学成分的研究

长鞭红景天化学成分的研究彭江南，葛永潮，李晓晖（军事医学科学院放射医学研究所，北京１００８５０）红景天是滋补强壮药物，目前正引起人们极大的兴趣，现已有一些产品上市。我们曾对数种红景天的化学成分进行过研究［１～４］。长鞭红景天（Ｒｈｏｄｉｏｌａｆａｓｔ...     

丝瓜叶化学成分研究

从丝瓜(Luffa cylinderica Roem)叶中分得三种成分,经光谱和化学方法确定其结构为21β-羟基丝石竹皂甙元(L-2),2α-羟基常春藤皂甙元-3-O-β-D-吡喃葡萄糖甙(L-8)和21β-羟基常春藤皂甙元-3-O-β-D-吡喃葡萄糖甙(L-10)。L-2和L-10为新的天然产物,依次命名为丝瓜素A(lucyin A)和丝瓜皂甙N(lucyoside N)。     

羟甲芬太尼立体异构体的晶体结构

对强效镇痛剂羟甲芬太尼的两个光学异构体体cis-(3R,4S,2′R)-羟甲芬太尼(I)和trans-(3R,4R,2′S)-羟甲芬太尼(Ⅱ)进行了X-射线衍射晶体结构分析。两个异构体均有一个sp³N(l)原子和一个sp²N(7)原子。哌啶环呈椅式构象,顺式异构体I的3-甲基处于直立键,4-N-苯基丙酰胺基处于平伏键;反式异构体II的3-甲基与4-N-苯基丙酰胺基均处于平伏键。在I分子中,C(4)原子与4-丙酰胺基组成的平面与N-苯环平面近似相互垂直,而在II中,两平面的二面角近似为100℃。两异构体分子中均存在分子内氢键O(1)一H…N(1),反式异构体II还存在分子间氢键O(1)一H(A)…O(2)(B)。     

3-甲基芬太尼立体异构体的合成、绝对构型和镇痛活性

报道3-甲基芬太尼(2)四个光学异构体的合成及其绝对构型的确定,并测定了各异构体的镇痛活性(小鼠,ip,热板法)。结果表明,cis-(+)-(3R,4S)-2的镇痛作用最强,ED₅₀0.00767 mg/kg,镇痛效能是吗啡的2600倍,比其对映体cis-(-)-(3S,4R)-2以及混旋的cis-(±)-2分别强119和1.5倍;trans-(+)-(3S,4S)-2的镇痛效能是吗啡的450倍、trans-(-)-(3R,4R)-2的4倍。     

6-(αα-二苯基乙酰哌嗪基苯基)-4,5-二氢-5-甲基-3(2H)-哒嗪酮对兔血小板聚集及TXB2,cAMP的影响

6-(αα-二苯基乙酰哌嗪基苯基)-4,5-二氢-5-甲基-3(2H)-哒嗪酮(简称DMDP)是我院新合成的哒嗪酮的衍生物。DMDP可以显著抑制由花生四烯酸(AA(?),ADP和血小板活化因子(PAF)诱导的免血小板聚集,其IC₅₀分别为1.12±0.1.4.19±0.5和2.97±0.1μmol/L。实验还表明DMDP在1～500 μmol/L浓度范围内呈剂量依赖性地抑制兔血小板内血栓素B₂含量,但升高兔血小板内环腺苷酸水平,这可能是其抑制血小板聚集的作用机理之一。