Amniotic fluid concentration of surfactant proteins in intra-amniotic infection

Objective. Pulmonary surfactant is a complex molecule of lipids and proteins synthesized and secreted by type II alveolar cells into the alveolar epithelial lining. Both lipid and protein components are essential for lung function in postnatal life. Infection is a well-established cause of preterm delivery, and several inflammatory cytokines play a role in the mechanisms of preterm parturition. An increased concentration of inflammatory cytokines in amniotic fluid or fetal plasma has been linked to the onset of preterm parturition and fetal/neonatal injury, including cerebral palsy and chronic lung disease. Experimental evidence indicates that inflammatory mediators also regulate surfactant protein synthesis, and histologic chorioamnionitis is associated with a decreased incidence of hyaline membrane disease in neonates. This study was conducted to determine if amniotic fluid concentrations of surfactant protein (SP)-A, SP-B, and SP-D change in patients with and without intra-amniotic infection (IAI).

Materials and methods. A case–control study was conducted to determine amniotic fluid concentrations of SP-A, SP-B, SP-D, and total protein in patients who had an amniocentesis performed between 18 and 34 weeks of gestation for the detection of IAI in patients with spontaneous preterm labor with intact membranes (n = 42) and cervical insufficiency prior to the application of cerclage (n = 6). Amniotic fluid samples were selected from a bank of biological specimens and included patients with (n = 16) and without (n = 32) IAI matched for gestational age at amniocentesis. Intra-amniotic infection was defined as a positive amniotic fluid culture for microorganisms. Each group was further subdivided according to a history of corticosteroid administration within 7 days prior to amniocentesis into the following subgroups: (1) patients without IAI who had received antenatal corticosteroids (n = 21), (2) patients with IAI who had received antenatal corticosteroids (n = 9), (3) patients without IAI who had not received antenatal corticosteroids (n = 11), and (4) patients with IAI who had not received antenatal corticosteroids (n = 7). Amniotic fluid was obtained by transabdominal amniocentesis. SP-A, SP-B, and SP-D concentrations in amniotic fluid were determined by enzyme-linked immunosorbent assay (ELISA). Non-parametric statistics were used for analysis.

Results. Women with IAI had a higher median amniotic fluid concentration of SP-B and of SP-B/total protein, but not other SPs, than those without IAI (both p = 0.03). Among patients who had received antenatal corticosteroids, the median amniotic fluid concentration of SP-B and of SP-B/total protein was significantly higher in patients with IAI than in those without IAI (SP-B, IAI: median 148 ng/mL, range 37.3–809 ng/mL vs. without IAI: median 7.2 ng/mL, range 0–1035 ng/mL; p = 0.005 and SP-B/total protein, IAI: median 14.1 ng/mg, range 4.3–237.5 ng/mg vs. without IAI: median 1.45 ng/mg, range 0–79.5 ng/mg; p = 0.003). Among women who had not received antenatal corticosteroids, the median amniotic fluid concentrations of SP-B and of SP-B/total protein were not significantly different between patients with and without IAI (SP-B, IAI: median 4 ng/mL, range 0–31.4 ng/mL vs. without IAI: median 3.4 ng/mL, range 0–37 ng/mL; p = 0.8 and SP-B/total protein, IAI: median 0.55 ng/mg, range 0–6.96 ng/mg vs. without IAI: median 0.59 ng/mg, range 0–3.28 ng/mg; p = 0.9). The median amniotic fluid concentrations of SP-A, SP-A/total protein, SP-D, and SP-D/total protein were not significantly different between patients with and without IAI whether they received antenatal corticosteroids or not (all p > 0.05).

Conclusions. IAI was associated with an increased amniotic fluid concentration of SP-B in patients who received antenatal corticosteroids within 7 days prior to amniocentesis.     

Sensitivity and specificity of helical computed tomography in the diagnosis of pulmonary embolism: a systematic review

PURPOSE: To determine the sensitivity and specificity of helical computed tomography (CT) for the diagnosis of pulmonary embolism and to determine the safety of withholding anticoagulant therapy in patients who have clinically suspected pulmonary embolism and negative results on helical CT. DATA SOURCES: The MEDLINE database was searched for all reports published from 1986 to October 1999 that evaluated the use of helical CT for the diagnosis of pulmonary embolism. Bibliographies of the retrieved articles were cross-checked to identify additional studies. STUDY SELECTION: All prospective English-language studies were selected. Retrospective studies, review articles, and case reports were excluded, and 5 of the 20 identified articles were excluded. The scientific validity of the remaining 15 articles was assessed. DATA EXTRACTION: Two of the authors used a priori, pre-defined criteria to independently assess each study. A third author resolved disagreements by adjudication. The pre-defined criteria were inclusion of a consecutive series of all patients with suspected pulmonary embolism, inclusion of patients with and those without pulmonary embolism, a broad spectrum of patient characteristics, performance of helical CT and pulmonary angiography (or an appropriate reference test) in all patients, and independent interpretation of the CT scan and pulmonary angiogram (or reference test). Specific data on sensitivity and specificity and the associated 95% CIs were recorded when available. DATA SYNTHESIS: No study met all of the predefined criteria for adequately evaluating sensitivity and specificity. The reported sensitivity of helical CT ranged from 53% to 100%, and specificity ranged from 81% to 100%. In no prospective study was anticoagulant therapy withheld without further testing for venous thromboembolism in consecutive patients with suspected pulmonary embolism. One prospective study reported the outcome of selected patients with negative results on helical CT who did not receive anticoagulant therapy. CONCLUSIONS: Use of helical CT in the diagnosis of pulmonary embolism has not been adequately evaluated. The safety of withholding anticoagulant treatment in patients with negative results on helical CT is uncertain. Definitive large, prospective studies should be done to evaluate the sensitivity, specificity, and safety of helical CT for diagnosis of suspected pulmonary embolism.     

Full thickness squamous atypia of the glans penis on a background of Zoon's plasma cell balanitis

Erythroplasia of Queyrat (EQ) or squamous cell carcinoma in situ of the glans penis developed in a 79 year old uncircumsised gentleman who had a six year prior history of biopsy proven Zoon's plasma cell balanitis (ZB) affecting the same site on the glans. Prior to the development of clinically evident EQ, the glans had been treated with topical pimecrolimus 1% for one month. The glans was subsequently treated with topical 5-flourouracil 5% for two weeks which resulted in clinical clearance.
EQ is obviously an important differential for penile plaques because of the potential for progression to squamous cell carcinoma, while ZB is generally regarded as benign. The differentiation can only be reliably made histologically.
There are other case reports of both EQ ( 1 ) and carcinoma of the penis ( 2 ) arising in patients with ZB, raising the question as to whether ZB may actually reflect a reaction to underlying pre-existing pathology or even a premalignant state.
The addition of topical pimecrolimus shortly before EQ became clinically evident in this patient is concerning in the light of recent concern regarding the carcinogenicity of topical calcineurin inhibitors ( 3 ).
This case highlights the importance of close clinical follow up of persistent penile inflammatory lesions and prompt biopsy of clinically suspicious areas as second and potentially more serious pathology may occur concomitantly.     

甲氨蝶呤的卷积极谱法测定和电极还原机理的研究

用高阶导数卷积极谱法研究了针剂和尿液中抗肿瘤药物甲氨蝶呤的微量测定法。在9.0×10^-8～1.6×10^(-5)mol/L内波高与浓度有线性关系。最低检测限为1.8×10^-8mol/L。与英国药典(1980)的标准方法进行了比较,极谱法具有更高的灵敏度。研究了甲氨蝶呤的电极还原机理。在Britton—Robinson缓冲溶液中甲氨蝶呤产生两个还原波。第一个波为可逆的2e—2H⁺电极还原过程,可供定量测定。第二个波为不可逆波。     

Upper and midureteral calculi: percutaneous extraction with an occlusion balloon catheter

In 44 patients with one or more calculi in the upper two-thirds of the ureter, single-stage percutaneous nephrolithotomy was performed through a middle or upper calyceal nephrostomy after cystoscopic placement of an occlusion balloon catheter distal to the calculus; in 42, the procedure was successful. The occlusion balloon catheter permitted retrograde opacification of all systems for enhanced renal puncture. In the last 30 patients an attempt was made either to push the calculus upward mechanically or to flush it upward into the renal pelvis with carbon dioxide or dilute contrast material. This was successful in 24 of these patients. Prior overnight occlusion of the ureter by means of ureteral dilatation further facilitates dislodgment of the calculus, which was successful in 12 of 13 patients.     

Biophysical and biological activity of a synthetic 8.7-kDa hydrophobic pulmonary surfactant protein SP-B.

We have synthesized pulmonary surfactant apoprotein SP-B peptides by solid-phase chemistry and demonstrated their ability to enhance the surface-active properties of synthetic lipid mixtures. The synthetic peptides were reactive with antiserum generated against the native bovine surfactant peptide. Both peptides conferred surfactant-like properties to synthetic lipid mixtures as assessed by a Wilhelmy balance and pulsating bubble surfactometer. Likewise, mixtures of synthetic SP-B peptides and lipid restored compliance of isolated surfactant-deficient rat lungs. This work demonstrates the utility of SP-B as a functional component of pulmonary surfactant mixtures for treatment of respiratory distress syndrome or other disorders characterized by surfactant deficiency.     

Peripheral airway cell differentiation in human lung cancer cell lines

Clara cells and type II pneumocytes are the progenitor cells of the bronchioles and alveoli, respectively. These peripheral airway cells (PAC) contain characteristic cytoplasmic structures and express surfactant associated proteins. PAC cell markers are expressed by many pulmonary adenocarcinomas having papillary and/or lepidic growth patterns, which are characteristics of the bronchioloalveolar and papillary subtypes. We investigated the expression of PAC markers in a panel of 41 lung cancer cell lines. Ultrastructural studies demonstrated the presence of cytoplasmic structures characteristic of Clara cells or of type II pneumocytes in 9 of 34 (26%) non-small cell lung cancer cell lines, including 7 of 17 (41%) adenocarcinomas, one squamous cell carcinoma, and one large cell carcinoma. Of interest, the cytoplasmic structures were present in 5 of 6 (83%) cell lines initiated from papillolepidic adenocarcinomas. In addition, we examined the lines for expression of the surfactant associated proteins SP-A, SP-B, and SP-C. Eight of the nine cell lines containing cytoplasmic inclusions characteristic of PAC cells also expressed protein and/or RNA of SP-A, the major surfactant associated protein. Five of these lines expressed SP-B RNA (either constitutively or after dexamethasone induction), while a single line expressed SP-C only after dexamethasone induction. None of six small cell lung cancer cell lines examined expressed any of the PAC markers. Thus, PAC markers are expressed frequently (but not exclusively) in pulmonary adenocarcinoma cell lines, especially in those initiated from tumors having papillolepidic growth patterns. The establishment and identification of multiple cell lines expressing PAC features provide an important new resource for biological and preclinical therapeutic studies.     

Laser densitometric analysis of class I HLA antigen expression by corneal epithelium

Laser densitometric analysis of immunoperoxidase stained tissue was used to quantitate class I HLA (HLA-A,B,C) antigen expression by human corneal epithelium. Frozen sections of human donor corneas stored in modified McCarey-Kaufman medium for less than 24 hr were evaluated for class I HLA antigen by an indirect immunoperoxidase technique using a monoclonal antibody reactive against a class I HLA antigen determinant. Photomicrographs of stained epithelium taken under standardized conditions were evaluated by laser densitometry. Measurements from peripheral and central corneal epithelium on the same tissue section were compared. Total stain, stain density, and stain intensity were higher for peripheral than for central corneal epithelium, indicating that class I HLA antigen expression is greater for peripheral than for central epithelium.