Herpes simplex virus seropositivity and reactivation at delivery among pregnant women infected with human immunodeficiency virus-1

OBJECTIVE: Our purpose was to determine whether pregnant women infected with human immunodeficiency virus-1 have an increased risk of herpes simplex virus-2 seropositivity and herpes simplex virus reactivation at delivery. STUDY DESIGN: Sixty women infected with human immunodeficiency virus and 8408 other patients who were delivered at the University of Washington between 1989 and 1995 had herpes simplex virus serologic determinations at delivery. Genital herpes simplex virus cultures were obtained for 48 (80%) of the human immunodeficiency virus-infected women and 5567 (66%) of the controls. Logistic regression was used to adjust for possible confounding factors. RESULTS: Forty-five (75%) of human immunodeficiency virus-infected women and 2709 (32%) controls were seropositive for herpes simplex virus-2 (p < 0.0001). Eight percent of human immunodeficiency virus-infected women and 2% of controls had herpes simplex virus reactivation in labor (p < 0.05). CONCLUSIONS: Infection with herpes simplex virus-2 is common among pregnant women infected with human immunodeficiency virus. Herpes simplex virus reactivation complicates labor in this group more often than in other obstetric patients. The role of herpes simplex virus in perinatal human immunodeficiency virus transmission warrants further study.     

Chromosome 1p36 deletions: the clinical phenotype and molecular characterization of a common newly delineated syndrome

Deletions of the distal short arm of chromosome 1 (1p36) represent a common, newly delineated deletion syndrome, characterized by moderate to severe psychomotor retardation, seizures, growth delay, and dysmorphic features. Previous cytogenetic underascertainment of this chromosomal deletion has made it difficult to characterize the clinical and molecular aspects of the syndrome. Recent advances in cytogenetic technology, particularly FISH, have greatly improved the ability to identify 1p36 deletions and have allowed a clearer definition of the clinical phenotype and molecular characteristics of this syndrome. We have identified 14 patients with chromosome 1p36 deletions and have assessed the frequency of each phenotypic feature and clinical manifestation in the 13 patients with pure 1p36 deletions. The physical extent and parental origin of each deletion were determined by use of FISH probes on cytogenetic preparations and by analysis of polymorphic DNA markers in the patients and their available parents. Clinical examinations revealed that the most common features and medical problems in patients with this deletion syndrome include large anterior fontanelle (100%), motor delay/hypotonia (92%), moderate to severe mental retardation (92%), growth delay (85%), pointed chin (80%), eye/vision problems (75%), seizures (72%), flat nasal bridge (65%), clinodactyly and/or short fifth finger(s) (64%), low-set ear(s) (59%), ear asymmetry (57%), hearing deficits (56%), abusive behavior (56%), thickened ear helices (53%), and deep-set eyes (50%). FISH and DNA polymorphism analysis showed that there is no uniform region of deletion but, rather, a spectrum of different deletion sizes with a common minimal region of deletion overlap.     

Nonclinical model for assessing gastric effects of bisphosphonates

Mechanisms by which ketones potentiate manganese-bilirubin (Mn-BR)-induced cholestasis are unknown. The purpose of the present study was to investigate the effect of methyl isobutyl ketone (MiBK), a widely used ketonic solvent, at the level of the bile canalicular membrane (BCM) and to verify if altered membrane lipid dynamics could be involved in MiBK-potentiated Mn-BR cholestasis. Male Sprague-Dawley rats were exposed 4 hr/day for 3 days to MiBK vapors (200 or 600 ppm). Eighteen hours after the last exposure, manganese (Mn, 4.5 mg/kg) was given i.v. followed 15 min later by bilirubin (BR, 25 mg/kg). Rats were killed 30 min after BR; liver cell plasma membranes (bile canalicular and sinusoidal), microsomes, mitochondria, and cytosol were isolated by differential centrifugation. Lipids were extracted and cholesterol was measured in each fraction. After Mn-BR and MiBK exposure (600 ppm), results indicated a marked increase in BCM cholesterol content compared to rats exposed to air only. This increase was greater than that due to Mn-BR or MiBK given alone. Also, results indicated that cholesterol increased in a dose-related fashion in BCM after MiBK exposure, whereas PM cholesterol remained unaltered. To identify the source of the increased BCM cholesterol and to permit distinction between de novo cholesterol synthesis and subcellular shifts, the hepatic lipid pool was labeled in vivo with [3H]-cholesterol and [2-14C]-mevalonic acid, a cholesterol synthesis precursor. Results showed that after 600 ppm MiBK exposure, 14C-labeled cholesterol was greater than 3H-labeled cholesterol, indicating that the contribution of de novo cholesterol synthesis to the total cholesterol content of the various isolated hepatocellular fractions was more important than the contribution of intracellular pools. Therefore, increased BCM cholesterol content and enhanced accumulation of newly synthesized cholesterol appear to be involved in MiBK potentiation of Mn-BR-induced cholestasis.     

Electron microscopic demonstration of an adenovirus in the hepatocytes of birds experimentally infected with hydropericardium syndrome

The final part of this series attempts to evaluate the relevance of Nazi medicine for doctors today. Euthanasia, informed consent, the conflict of interests of the individual versus those of society and racism were as prominent themes of Nazi medicine as they are today. It would be foolish not to learn from experiences of the past. Nazi medicine can therefore never be an irrelevant subject of the days gone by.     

Experimental and Theoretical Study on High Strength Steel Extended Endplate Connections After Fire

In order to reveal more information and better understanding on the behavior and failure mechanisms of high strength steel (HSS) extended endplate connections at ambient temperature and after fire, an experimental and theoretical study has been conducted and presented in this paper. The provisions of Eurocode 3 are verified with the test results. Because strength of bolts decreases more rapidly than that of structural steels, failure modes of endplate connections may change after fire. Hence, a series of equations are proposed to predict failure modes of endplate connections after fire. Furthermore, FE simulations which can predicate the performance of HSS extended endplate connections with reasonable accuracy are adopted to study the behaviors of the connections after cooling down from various fire temperatures and to validate the accuracy of the proposed equations. Moreover, a parametric study is carried out to explore an optimization design method. It is found that the current provisions of EC3 can justifiably predict failure modes and plastic flexural resistances of HSS extended endplate connections both at ambient temperature and cooling down from 550 °C, but it is not the case for their initial rotational stiffness and rotation capacity. In order to avoid brittle failure mode of endplate connections after fire, appropriately increasing the diameter or grade of bolts in the design is suggested. What is more, the match of steel grade and thickness of column flange and endplate as well as beam should be considered in the optimization design of beam-column endplate connections.     

Channelled optical fibre photoreactor for improved air quality control

An optical fibre reactor with 30 hexagonal-shaped channels distributed within the optical fibre structure was investigated as a gas-phase photocatalytic reactor. TiO₂ photocatalyst, with SiO₂ sol acting as a binder, was coated on the channel walls at a thickness of 1.5 μm. Effective light propagation lengths of 3.4 and 4.9 cm were observed for incidental angles of 81.5° and 87.1°, respectively. The TiO₂-coated channelled optical fibre reactor (COFR) was assessed for the photocatalytic degradation of gas-phase ethylene. The photocatalytic reaction rate of ethylene degradation was linear with respect to the incident photons. The reaction rate order for the incident photons was determined to be 0.93. Despite a longer effective light propagation length for an incidental angle of 87.1°, the quantum yield was independent of the incidental angle. The independence of the quantum yield on the incident photons and the angle of light incidence was attributed to the COFR design, where the propagating light was wholly confined within the reactor and, in turn, more effectively utilised by the TiO₂.     

正交异性钢桥面板改造的组合粘结系统

<正>交异性钢桥面板改造的问题在于既有钢板与第二个钢板的粘结,以降低应力和增加正交异性钢板的使用寿命。通过试验和分析,对梁的弯曲性能进行参数研究。试验考虑不同厚度、温度和跨度的影响。从试验结果可见,应力降低与温度无关。最小化第二块钢板的厚度及最大化粘结层厚度,可降低重量,增加组合结构的刚度,这是最有效的解决方法。组合梁的弹性性能和屈服荷载取决于钢板的性能,温度的影响不显著。然而,粘结层的受剪最终导致梁的破坏,而粘结层的性能受温度的影响较大。     

Detection of Legionella spp. and some of their amoeba hosts in floating biofilms from anthropogenic and natural aquatic environments

Floating biofilms develop at the water-air interface and harbor numerous microorganisms, some of which are human pathogens like Legionella pneumophila. The presence of Legionella spp. and especially L. pneumophila in such biofilms was investigated. In parallel, the occurrence of Naegleria spp., Acanthamoeba spp., Willaertia spp., Vahlkampfia spp. and Hartmanella spp. was determined and it was examined whether Acanthamoeba spp. isolates were naturally infected with L. pneumophila bacteria. Eight anthropogenic and 37 natural aquatic environments were sampled between June and August 2005. Both Legionella spp. and L. pneumophila were present in 100% of the floating biofilms of the anthropogenic aquatic systems. Eighty-one percent of all natural floating biofilm samples were positive for Legionella spp. and 70% of these samples were positive for L. pneumophila. Legionella concentrations were in the range of 10(1)-10(2)cells/cm(2). Naegleria spp. and Acanthamoeba spp., two well-known L. pneumophila amoeba hosts, were present in 50-92% and 67-72% of floating biofilm samples, respectively. Acanthamoeba spp. isolates appeared to be naturally infected with L. pneumophila bacteria as proved by fluorescent in situ hybridization.