Pregnancy outcomes among women with hemoglobin E trait

Objective: To compare the maternal and fetal outcomes between pregnant women complicated with hemoglobin E (HbE) trait and normal controls.

Patients and methods: A retrospective cohort study was conducted by assessment of the database of maternal–fetal medicine units from January 2003 to December 2013 to identify singleton pregnant women complicated by HbE trait. Pregnancies with medical complications or fetal anomalies were excluded. The normal controls were low-risk pregnancies and were non-carrier status for thalassemia and hemoglobinopathy.

Result: During the study period, 1073 women with HbE trait and 2146 normal controls were included. The baseline characteristics of the two groups were comparable except that the number of prenatal visit was statistically higher in study group (8.55?±?3.03 versus 7.85?±?4.33, p?=?<0.001). Most pregnancy outcomes were not significantly different. However, the rate of asymptomatic bacteriuria was minimally higher in the study group, 3.5% versus 2.3%; p?=?0.042 (relative risk 1.19; 95%CI: 0.98–1.43). Note that the rates of gestational diabetes tend to be higher in the group of HbE trait (7.6% versus 6.8%), but did not reach a statistical level.

Conclusion: The HbE trait does not significantly increase risk of common adverse pregnancy outcomes, except for minimal increase in asymptomatic bacteriuria.     

Proteomic Analysis of Rickettsia parkeri Strain Portsmouth

Rickettsia parkeri, a recently recognized pathogen of human, is one of several Rickettsia spp. in the United States that causes a spotted fever rickettsiosis. To gain insights into its biology and pathogenesis, we applied the proteomics approach to establish a two-dimensional gel proteome reference map and combined this technique with cell surface biotinylation to identify surface-exposed proteins of a low-passage isolate of R. parkeri obtained from a patient. We identified 91 proteins by matrix-assisted laser desorption ionization-tandem time of flight mass spectrometry. Of these, 28 were characterized as surface proteins, including virulence-related proteins (e.g., outer membrane protein A [OmpA], OmpB, β-peptide, and RickA). Two-dimensional immunoblotting with serum from the R. parkeri-infected index patient was utilized to identify the immunoreactive proteins as potential targets for diagnosis and vaccine development. In addition to the known rickettsial antigens, OmpA and OmpB, we identified translation initiation factor 2, cell division protein FtsZ, and cysteinyl-tRNA synthetase as immunoreactive proteins. The proteome map with corresponding cell surface protein analysis and antigen detection will facilitate a better understanding of the mechanisms of rickettsial pathogenesis.Rickettsia parkeri, a member of the spotted fever group Rickettsia (SFGR), was first isolated from the Gulf Coast tick, Amblyomma maculatum, in 1937 (29). In 2004, the first confirmed human infection with R. parkeri was reported in a 40-year-old man from the Tidewater area of coastal Virginia. The agent was isolated in cell culture from an eschar biopsy specimen and designated the Portsmouth strain (28). Recently, the first recognized case of tick bite-associated human infection was described (43); however, the epidemiology of R. parkeri is not well defined. In the United States, R. parkeri has been detected in A. maculatum and A. americanum; the geographical overlap between R. parkeri and these ticks with that of the vectors of R. rickettsii (the etiological agent of Rocky Mountain spotted fever [RMSF]) suggests that many cases of R. parkeri infection have been misidentified as RMSF (27, 35). For example, Western blot analysis of serum specimens from 15 U.S. patients previously diagnosed with RMSF identified four serum specimens reactive with a 120-kDa protein of R. parkeri, suggesting infection with R. parkeri rather than R. rickettsii (30). However, a serologic test specific for this pathogen is not available (43), and little is known about its biology.Due to their obligate intracellular nature, genetic manipulation of Rickettsia has proven difficult. Alternatively, protein expression profiles (proteomes) are utilized to identify the mechanisms of pathogenesis and differentiate rickettsial species recognizing host immune response specificity to cell surface molecules, referred to as outer membrane proteins (Omps). The presence or absence of some Omps allows for differentiation between the typhus group and the SFGR, and the response to some species within the SFGR is specific (2). Proteomes have been developed for R. prowazekii (7), R. conorii (31), and R. felis (26) by using two-dimensional liquid chromatography-tandem mass spectrometry (2D LC-MS/MS), two-dimensional polyacrylamide gel electrophoresis (2D PAGE) and MS, or sodium dodecyl sulfate (SDS)-PAGE and nanoLC-MS/MS, respectively. More recently, an emphasis has been placed on better understanding surface protein expression profiles for obligate intracellular bacteria in the family Anaplasmataceae since it is well recognized that Omps for these bacteria are critical for host cell invasion (12, 13). Likewise, the rickettsial Omps are critical for bacterial attachment and invasion of host cells (21, 23, 40).To better understand the molecular basis of virulence of R. parkeri, we utilized 2D PAGE with a pH 3-10 immobilized pH gradient (IPG) coupled with matrix-assisted laser desorption ionization-tandem time of flight (MALDI-TOF/TOF) MS in order to establish the protein expression profile of a low-passage strain of R. parkeri isolated from an infected patient. This reference map will be useful for comparative analyses of protein profiling of R. parkeri as it is maintained under differing microenvironments (e.g., in the arthropod vector and vertebrate host). Biotinylation of cell surface proteins and 2D immunoblotting analysis were also used to identify the surface-exposed proteins and immunoreactive proteins as potential targets for diagnosis and vaccine development.     

Identification of Rickettsia felis in the salivary glands of cat fleas

Rickettsia felis, a flea-associated rickettsial pathogen, has been identified in many tissues, including the digestive and reproductive tissues, within the cat flea, Ctenocephalides felis. We utilized transmission electron microscopy and polymerase chain reaction to identify R. felis in the salivary glands of fed fleas and further define the distribution of R. felis within the arthropod host. We identified Rickettsia-like organisms in salivary glands using electron microscopy. Sequence analysis of portions of the Rickettsia genus-specific 17-kDa antigen gene and R. felis plasmid confirmed the morphological identification of R. felis in cat flea salivary glands. This is the first report of R. felis in tissues critical for horizontal transmission of rickettsiae.     

Polymorphisms in the glucocerebrosidase gene and pseudogene urge caution in clinical analysis of Gaucher disease allele c.1448T>C (L444P)

Background  

Gaucher disease is a potentially severe lysosomal storage disorder caused by mutations in the human glucocerebrosidase gene (GBA). We have developed a multiplexed genetic assay for eight diseases prevalent in the Ashkenazi population: Tay-Sachs, Gaucher type I, Niemann-Pick types A and B, mucolipidosis type IV, familial dysautonomia, Canavan, Bloom syndrome, and Fanconi anemia type C. This assay includes an allelic determination for GBA allele c.1448T>C (L444P). The goal of this study was to clinically evaluate this assay.     

A placebo-controlled,double-blind,randomized study of single-dose intravenous diclofenac for pain relief after a cesarean section

BackgroundThis study was conducted to avoid the pain of an intramuscular injection of diclofenac after a cesarean section, by modifying it to an intravenous infusion by diluting it with 5% dextrose in 100 mL of water.ObjectiveThe aim of this study was to determine the efficacy of a single-dose modified diclofenac being given intravenously, instead of intramuscularly, for pain relief after a cesarean section.Study designA double-blind, randomized controlled trial was conducted.ParticipantsWe enrolled 30 patients who underwent cesarean sections with Pfannenstiel skin incision.MethodsAll patients received 2.2–2.5 mL of 0.5% bupivacaine with 0.2 mg morphine for spinal anesthesia. The participants were equally and randomly allocated to two groups to receive intravenous diclofenac or placebo at 12 hours postoperatively. Both groups received the same regimen for postoperative pain control.Main outcome measurementsThe severity of postoperative pain was measured directly using a verbal numerical rating scale (0–10) and a pain-relief scale (1–4), and indirectly from the amount of tramadol used.ResultsThe characteristics of the two groups of patients were similar. The mean postoperative pain relief at 24 hours in the study group was better than that in the control group (3.14 ± 0.66 vs. 2.13 ± 0.99; p < 0.05). The severity of postoperative pain at 24 hours and the amount of tramadol used were not different between groups.ConclusionIntramuscular diclofenac (75 mg), modified by diluting it with 5% dextrose in 100 mL of water, for intravenous administration in combination with spinal morphine (0.2 mg) provided good analgesia after a cesarean section within 24 hours when assessed by the pain-relief scale; however, the mean pain intensity was not different.