新的高强度高选择性阿片μ受体激动剂［~11C］－羟甲芬太尼的合成

羟甲芬太尼（Ｉ）是一个新的高强度高选择性阿片μ受体激动剂。本文用ｃｉｓ－Ａ－Ｎ－［１－（２－羟基－２－苯乙基）－３－甲基－４－哌啶基］－苯胺（ＩＩ）或ｃｉｓ－Ｎ－［１－（苯甲酰甲基）－３－甲基－４－哌啶基］－苯胺（ＩＩＩ）作为前体合成了［１１Ｃ］－羟甲芬太尼，以便用正电子发射断层扫描（ＰＥＴ）来观察μ受体。通过水解ｃｉｓ－Ａ－羟甲芬太尼（Ｉ）和ｃｉｓ－Ｎ－［１－（苯甲酰甲基）－３－甲基－４－哌啶］－Ｎ－苯基丙酰胺（ｃｉｓ－ＩＶ）的４－Ｎ－丙酰基分别获得ＩＩ和ＩＩＩ。溴乙烷的格氏试剂与回旋加速器产生的［１１Ｃ］－二氧化碳反应后继而直接加入邻苯二甲酸二酰氯和２，６－二叔丁基吡啶生成同位素标记中间体［１１Ｃ］－丙酰氯。［１１Ｃ］－丙酰氯与ＯＨ－前体（ＩＩ）反应后再经ＨＰＬＣ分离纯化直接得［１１Ｃ］－羟甲芬太尼；［１１Ｃ］－丙酰氯与酮－前体（ＩＩＩ）反应后，再用硼氢化钠甲醇溶液处理，然后进行ＨＰＬＣ分离纯化得［１１Ｃ］－羟甲芬太尼。两种方法均可获得ｌｌ．１～１４．８ＧＢｑ／μｍｏｌ的特异性放射化学纯［１１Ｃ］－羟甲芬太尼。总共耗时为４０～５０ｍｉｎ（ＥＯＢ）。     

Heterologous protection in pigs induced by a plasmid-cured and crp gene-deleted Salmonella choleraesuis live vaccine

In this study, we exploited a crp (cAMP receptor protein) gene-deleted, virulence plasmid-cured Salmonella choleraesuis mutant with decreased carbon source utilization, designated S.C.-Deltacrp/vpl(-), as a live vaccine strain. Normal weight gain with no clinical signs was observed in pigs immunized with high doses of S.C.-Deltacrp/vpl(-) live vaccine. Vaccination in pregnant sows induced high maternal antibodies, which could prevent piglets from Salmonella infection. Moreover, serial transmission of the vaccine strain in piglets produced no evidence of reversion to virulence. Furthermore, the peripheral blood mononuclear cells from immunized piglets also developed Salmonella specific T-cell proliferative response in vitro. Our results indicate that immunogenic antigens in S.C.-Deltacrp/vpl(-) can induce adequate immunity to protect pigs against challenge with a heterologous virulent strain. Thus, this mutant holds promise for the development of a new live S. choleraesuis vaccine.     

Detection of Mycobacterium tuberculosis in bronchoalveolar lavage from patients with sputum smear-negative pulmonary tuberculosis using a polymerase chain reaction assay

Abstract The objective of this study was to evaluate the utility of a polymerase chain reaction (PCR) assay in detecting Mycobacterium tuberculosis in bronchoalveolar lavage (BAL) specimens of patients suspected of having active pulmonary tuberculosis (TB) but who were sputum smear-negative. Patients undergoing investigation for suspected pulmonary TB at the University Hospital, Kuala Lumpur, and who were sputum smear-negative underwent fibreoptic bronchoscopy and BAL. One portion of each lavage specimen was submitted for smear examination for acid-fast bacilli and mycobacterial culture and the other portion assayed by PCR for the presence of a 562-base pair DNA segment belonging to the insertion sequence IS986, unique to the M. tuberculosis complex. As controls, lavage specimens from patients with other lung lesions were also similarly tested. The PCR assay gave a positivity rate of 80.9% (55 of 68) compared with 8.8% of smear examination and 7.4% of culture for detecting M. tuberculosis in BAL specimens. The assay was positive in two of 45 BAL specimens from 35 control subjects. The PCR assay was more sensitive than smear and culture in detecting M. tuberculosis in BAL specimens of patients with sputum smear-negative pulmonary TB.     

Recombinant human interleukin-3 stimulation of hematopoiesis in humans: loss of responsiveness with differentiation in the neutrophilic myeloid series

Recombinant human (rh) interleukin-3 (IL-3) stimulated the proliferation and differentiation of erythroid, granulocyte, macrophage, eosinophil (Eo), and mixed colonies as well as megakaryocytes from human bone marrow cells. rh IL-3 was a weaker stimulus than rh granulocyte-macrophage colony-stimulating factor (GM- CSF) for day 14 myeloid cell colonies. At day 7 of incubation, rh IL-3 stimulated a few G, M, and Eo clusters but no colonies. This loss of responsiveness of myeloid cells to rh IL-3 was accentuated with further differentiation of the cells. rh IL-3 stimulated very few or no clones after five-day incubation with enriched promyelocytes and myelocytes, whereas rh GM-CSF was an efficient stimulus. Responsiveness to rh IL-3 was completely lost in postmitotic mature neutrophils. Incubation of these cells with rh IL-3 did not result in enhanced antibody-dependent cell-mediated cytotoxicity (ADCC) of tumor cells or superoxide anion production after stimulation with formyl-methyl-leucyl-phenylalanine (FMLP), although they could be stimulated by rh GM-CSF. In addition, preincubation of neutrophils with different concentrations of rh IL-3 failed to increase or decrease their response to rh GM-CSF. In contrast to neutrophils, mature Eos could be stimulated by rh IL-3 to kill antibody-coated tumor cells. These results show that cells of the neutrophilic myeloid series lose their responsiveness to h IL-3 as they differentiate and suggest that although h IL-3 may be an important therapeutic agent to use for hematopoietic regeneration in vivo, the lack of stimulation of mature neutrophil function makes it an unlikely sole candidate as adjunct therapy for treatment of infectious diseases.     

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.     

Fecal triglyceride excretion is not excessive in pancreatic insufficiency

Steatorrhea can result from maldigestion or malabsorption. As the pathophysiology underlying impaired digestion differs from impaired absorption, it is important to differentiate these two disorders. It is generally accepted that patients with maldigestion excrete an excessive amount of triglyceride and patients with malabsorption excrete an excess of the lipolytic product of triglyceride, fatty acid. The two-step Sudan stain has been used as a simple test to differentiate these disorders. The validity of the test has not yet been established. In this study, fecal fatty acid and triglyceride were measured after extraction and thin-layer chromatographic separation. Our results indicate that in adult patients with pancreatic insufficiency, the fecal triglyceride content does not differ from the controls. However, a fivefold to sixfold increase in fecal fatty acid content in patients with pancreatic insufficiency was revealed. As patients with maldigestion do not excrete an excess of undigested triglyceride, it is not possible to differentiate maldigestion from malabsorption by quantifying fecal triglyceride and fatty acid.     

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