Active surfactant in pharyngeal aspirates of term neonates: lipid biochemistry and surface tension function

Alveolar surfactant is well known for its ability to reduce minimal surface tension at the alveolar air–liquid interface to values below 5 mN m^?1. In addition, it has been suggested that surfactant is also present in the airways, particularly in the perinatal period. We isolated surfactant from pharyngeal aspirates obtained from 33 neonates immediately after delivery and analysed it for both phospholipid (PL) composition and surface tension function. PL classes and phosphatidylcholine (PC) molecular species were determined by normal and reversed-phase high-performance liquid chromatography (HPLC), respectively. Static and dynamic surface properties of the surfactant were studied in a pulsating bubble surfactometer. Sample volume was 1.3 ± 0.5 mL (mean ± SD) with a total amount of 2.5 ± 1.3 μmol of PL and a concentration of 2.1 ± 1.0 μmol mL^?1 PL. HPLC analyses of PL classes revealed a composition identical with surfactant prepared from alveolar washes, i.e. PC 83.6 ± 2.1%, sphingomyelin 1.4 ± 0.5%, phosphatidylglycerol 8.1 ± 1.6%, phosphatidylethanolamine 2.1 ± 0.5% and phosphatidylinositol 2.6 ± 1.1%. Thin-layer chromatography showed almost identical results but was more time-consuming and needed more material for analysis. Analysis of PC molecular species revealed a composition typical of human alveolar surfactant with 54.7 ± 3.9% dipalmitoyl PC, 10.3 ± 1.9% palmitoyloleoyl PC and 9.1 ± 1.5% palmitoylmyristoyl PC. Minimal surface tension fell to values below 5 mN m^?1 within 5 min of cycling in all subjects. The methods used in this study allowed for complete PL and surface tension analyses of surfactant obtained during routine pharyngeal suctioning after delivery at term. Whether they are also applicable to preterm neonates with respiratory distress remains to be determined.     

Attenuation of myocardial injury due to oxygen free radicals(OFR) by pretreatment with OFR or calcitonin gene-related peptide

目的：研究氧自由基（ＯＦＲ）及降钙素基因相关肽（ＣＧＲＰ）预处置对ＯＦＲ所致离体大鼠心脏损伤的拮抗作用．方法：Ｌａｎｇｅｎｄｏｒｆ法灌流心脏，电解ＫＨ液产生ＯＦＲ．结果：ＣＧＲＰ或ＯＦＲ预处置减轻ＯＦＲ所致心脏收缩功能下降，冠脉流量减少和肌酸激酶（ＣＫ）释放增加．蛋白激酶Ｃ（ＰＫＣ）抑制剂Ｈ７可取消ＯＦＲ预处置的心脏保护作用（对照组，ＯＦＲ损伤组，ＯＦＲ预处置组，Ｈ７加ＯＦＲ预处置组及Ｈ７组的ＣＫ释放量分别是１１０±７，２１５±２３，１６９±１４，２４０±３０，１１３±１９Ｕ·Ｌ－１）．结论：ＯＦＲ或ＣＧＲＰ预处置对ＯＦＲ所致心肌损伤具有拮抗作用，该作用与ＰＫＣ激活有关．     

Efficacy I: a new method for estimating relative efficacy of full agonists via a newly defined efficacy related parameter

A new method for estimating relative efficacies and relative intrinsic efficacies of agonists is described. Relative efficacy is estimated by employing a newly defined efficacy related parameter (e^ES) and it may be estimated without prior knowledge of efficacy values or the value of the equilibrium dissociation constants, K_A, of agonist-receptor complexes. The parameter e^ES is directly related to efficacy (e) and is defined as the ratio of maximal stimulus to maximal effect of an agonist. The value of e^ES indicates whether or not spare receptors are present for a particular agonist–effector system. The e^ES values of agonists are estimated by utilizing submaximal concentration–effect curves determined with fixed agonist-competitive antagonist concentration combinations and choosing a suitable reference (height of an agonistic concentration–effect curve) to which the height of the stimulus concentration–effect curves of the agonist may be compared. In addition to e^ES, other new agonist–effector parameters, namely S_Em/S_m and φ_min, were also defined.     

东北边境地区吸血蠓的调查研究

1980～1988年在东北边境的漠河、珲春县等10个县区采获吸血蠓2属37种,其中发现4个新种和4个国内新记录。不显库蠓(35.7％)和刺螯库蠓(34.9％)为优势蠓种。不同生境、场所和季节的蠓种组成有所不同。灰黑库蠓、淡角库蠓和端斑库蠓在整个活动季节均只出现一次高峰,而不显库蠓、刺螫库蠓和兴安库蠓在整个活动季节均出现两次高峰。刺螫库蠓的活动季节最长,为11旬,端斑库蠓最短,仅为5旬。刺螫库蠓、不显库蠓、兴安库蠓和灰黑库蠓在昼夜24小时均出现晨、昏两次活动高峰,而边缘库蠓只在凌晨出现一次晨峰。     

A protease inhibitor attenuates gastric erosions and microcirculatory disturbance in the early period after thermal injury in rats

The effects of camostat mesilate, a synthetic serine protease inhibitor on gastric microcirculation and active oxygen species generated by leucocytes from the gastric and jugular veins in the early period after thermal injury were assessed. Male Wistar rats were anaesthetized and a 30% full skin-thickness dorsal burn was inflicted. Camostat mesilate (100 mg/kg) was dissolved in distilled water and administered orally to rats 40 min before thermal injury (the camostat group). The control animals (the vehicle group) were administered distilled water orally. Rolling leucocytes as well as Monastral blue B deposits in venules were observed using in vivo microscopy. Active oxygen species were measured by chemiluminescence. Camostat mesilate decreased the total length of gastric erosion, venular deposits of Monastral blue B, and rolling of leucocytes in venules, and relatively increased luminol-dependent chemiluminescence activity generated by zymosan-stimulated leucocytes 15 min after thermal injury. These results suggest that serine proteases are involved in the formation of gastric erosions and gastric microcirculatory disturbance in the early period after thermal injury.     

Andrology: Analysis of sperm movement in relation to the oxidative stress created by leukocytes in washed sperm preparations and seminal plasma

The addition of luminol to unprocessed semen samples resultedin the generation of chemiluminescent signals, the intensityof which was highly correlated with the level of leukocyte contamination.Despite the spontaneous oxidant-generating capacity of seminalleukocytes, no correlations were observed between leukocytecontamination and the fertility status of the subjects or anyaspect of the semen profile, including the motility of the spermatozoaor their performance in a hyaluronate penetration assay. Luminol-dependentchemiluminescence and leukocyte contamination were also correlatedin washed sperm suspensions prepared either by repeated centrifugationor on discontinuous Percoll gradients. However, in such spermsuspensions, the spontaneous generation of oxidants by contaminatingleukocytes (>2x10⁴ leukocytes/ml) was invariably associatedwith a decreased capacity for movement. Moreover, causativeassociations between leukocyte contamination, reactive oxygenspecies generation, lipid peroxidation and impaired sperm motilitywere revealed by experiments involving the selective additionor removal of activated leukocytes. From these observationswe can conclude that low concentrations of leukocytes are acommon feature of the human ejaculate and can impair sperm function,particularly in the absence of seminal plasma. These findingshave implications for our understanding of the importance ofleukocytospermia in defining the fertility of human spermatozoain vivo and in vitro.     

Breast cancer risk with postmenopausal hormonal treatment

This review was designed to determine from the best evidence whether there is an association between postmenopausal hormonal treatment and breast cancer risk. Also, if there is an association, does it vary according to duration and cessation of use, type of regimen, type of hormonal product or route of administration; whether there is a differential effect on risk of lobular and ductal cancer; and whether hormone treatment is associated with breast cancers that have better prognostic factors? Data sources for the review included Medline, the Cochrane Database of Systematic Reviews (Cochrane Library, 2005) and reference lists in the identified citations. Eligible citations addressed invasive breast cancer risk among postmenopausal women and involved use of the estrogen products with or without progestin that are used as treatment for menopausal symptoms. Abstracted data were demographic groupings, categories of hormone use, categories of breast cancer, two-by-two tables of exposure and outcome and adjusted odds ratios, relative risks (RRs) or hazard rates. Average estimates of risk were weighted by the inverse variance method, or if heterogeneous, using a random effects model. The average risk of invasive breast cancer with estrogen use was 0.79 [95% confidence interval (95% CI) = 0.61-1.02] in four randomized trials involving 12 643 women. The average breast cancer risk with estrogen-progestin use was 1.24 (95% CI = 1.03-1.50) in four randomized trials involving 19 756 women. The average risks reported in recent epidemiological studies were higher: 1.18 (95% CI = 1.01-1.38) with current use of estrogen alone and 1.70 (95% CI = 1.36-2.17) with current use of estrogen-progestin. The association of breast cancer with current use was stronger than the association with ever use, which includes past use. For past use, the increased breast cancer risk diminished soon after discontinuing hormones and normalized within 5 years. Reasonably adequate data do not show that breast cancer risk varies significantly with different types of estrogen or progestin preparations, lower dosages or different routes of administration, although there is a small difference between sequential and continuous progestin regimens. Epidemiological studies indicate that estrogen-progestin use increases risk of lobular more than ductal breast cancer, but the number of studies and cases of lobular cancer remains limited. Among important prognostic factors, the stage and grade in breast cancers associated with hormone use [corrected] do not differ significantly from those in non-users, but breast cancers in estrogen-progestin users are significantly more likely to be estrogen receptor (ER) positive. In conclusion, valid evidence from randomized controlled trials (RCTs) indicates that breast cancer risk is increased with estrogen-progestin use more than with estrogen alone. Epidemiological evidence involving more than 1.5 million women agrees broadly with the trial findings. Although new studies are unlikely to alter the key findings about overall breast cancer risk, research is needed, however, to determine the role of progestin, evaluate the risk of lobular cancer and delineate effects of hormone use on receptor presence, prognosis and mortality in breast cancer.     

Serodiagnosis of tuberculosis and leprosy by enzyme immunoassay

Objective: To evaluate the use of serodiagnosis for tuberculosis and leprosy using mycobacterial antigen 38 kDa, with kits from Omega laboratories, to detect IgG by enzyme immunoassay (EIA).
Method: The study population consisted of 58 patients with evidence of tuberculous infection (culture of Mycobacterium tuberculosis complex or microscopic evidence), of whom 23 had pulmonary and 35 had extrapulmonary disease. There were six subjects who had recently been treated for tuberculosis, 11 patients on treatment for leprosy and 137 patients suspected of having tuberculosis on clinical or radiologic grounds (without laboratory evidence). A control group comprised 35 healthy individuals or patients suffering from diseases other than tuberculosis.
Results: The tests showed that there was a significant difference in antibody levels between the patients with active pulmonary disease, extrapulmonary tuberculosis and leprosy in comparison with the control group ( p <0.001). The sensitivities of the two tests together for proven pulmonary tuberculosis were 100% and 95.7% at 1.0–1.5 and >1.6 EIA cut-off points respectively, while the specificities were 88.5% and 100% at the same cut-off points. The sensitivities for extrapulmonary tuberculosis were 71.4% and only 51.4% at 1.0–1.5 and >1.6 EIA cut-off points. The test was positive in 30 (21.9%) of the 137 suspected patients, while 43 (31.4%) had an equivocal result and the remaining 64 (47.7%) suspects were definitely negative. There was again a significant difference in positivity rates between suspects and the control group.
Conclusions: Omega IgG test is useful in the serodiagnosis of active pulmonary tuberculosis and leprosy, but less sensitive in extrapulmonary disease, particularly in children. Equivocal results may only add to the evidence of tuberculosis in early or minimal disease.     

Bestimmung der biologischen Aktivität von synthetischem Secretin

Zusammenfassung Die relative Wirksamkeit von synthetischem Secretin (Wünsch) und reinem natürlichen Secretin ohne Zusatz von Cysteinhydrochlorid (Mutt) sowie von reinem natürlichem Secretin mit Zusatz von Cysteinhydrochlorid (G.I.H. Research Unit) wurde am Parameter der Volumen-und Bicarbonatsekretion des Pankreas bei 10 narkotisierten Bastardhunden geprüft. Die relative Wirksamkeit von synthetischem Secretin liegt — bezogen auf Gewichtsbasis — bei 100% gegenüber natürlichem (Mutt) (Parameter: Volumen- und Bicarbonatsekretion). Die biologische Aktivität von synthetischem Secretin beträgt ungefähr 3,58 klin. E/µg (Parameter: Volumensekretion) bzw. 3,88 klin. E/µg (Parameter: Bicarbonatsekretion) gegenüber dem Secretin mit Zusatz von Cysteinhydrochlorid (G.I.H. Research Unit). Natürliches Secretin (Mutt) hat eine biologische Aktivität gegenüber dem Secretin mit Zusatz von Cysteinhydrochlorid (G.I.H. Research Unit) von annähernd 3,52 klin. E/µg (Parameter: Volumensekretion) bzw. 3,48 klin. E/µg (Parameter: Bicarbonatsekretion).Durchgeführt mit Unterstützung der Deutschen Forschungsgemeinschaft.     

Reducing the time of sperm-oocyte interaction in human in-vitro fertilization improves the implantation rate

Human oocyte development was evaluated after a reduced timeexposure to spermatozoa in vitro. A total of 119 patients wereassigned to two study groups in a randomized prospective studyin which each patient‘s oocytes were exposed to spermatozoafor either 1 h (group 1 – 58 patients) or the standard16 h incubation period (group 2 – 61 patients). The fertilizationrate obtained in group 1 was higher than in group 2 (285/393,73%, and 272/410, 66% respectively), suggesting that the spermatozoa-oocyteinteraction occurs within 1 h. This was confirmed in a studyin vitro using fluorescently labelled spermatozoa and normaloocyte-cumulus complexes. Spermatozoa enter the cumulus complexwithin 15 min, traverse the cumulus layer within 3 h, and firstappear in the oocyte cortex at 4 h post-insemination. The incidenceof polyspermy was higher in oocytes exposed to spermatozoa for16 h (3%) than for 1 h (1%). There was no difference in thecleavage rate or morphological characteristics of embryos fromboth study groups. However, when evaluating the timing of embryodevelopment, group 1 generated a significantly higher percentageof four to five cell embryos when compared to group 2 (55 versus39%; P < 0.001), documented at 40 h post-insemination. Theimplantation and pregnancy rates for group 1 were 11 and 28%,while the corresponding rates for group 2 were 8 and 15%. Thissuggests that a reduced exposure of oocyte to spermatozoa favoursembryo viability, possibly due to a decrease in potential damagefrom sperm metabolic waste products.