Serologic evidence of previous Campylobacter jejuni infection in patients with the Guillain-Barré syndrome

OBJECTIVE: To determine if patients with the Guillain-Barré syndrome are likely to have had Campylobacter jejuni infection before onset of neurologic symptoms. DESIGN: A case-control study. SETTING: Several university medical centers. PATIENTS: Case patients met clinical criteria for the Guillain-Barré syndrome between 1983 and 1990 and had a serum sample collected and frozen within 3 weeks after onset of neurologic symptoms (n = 118). Disease controls were patients with other neurologic illnesses (n = 56); healthy controls were hospital employees or healthy family members of patients (n = 47). MEASUREMENTS: Serum IgA, IgG, and IgM antibodies to C. jejuni were determined by enzyme-linked immunosorbent assays. Assays were done in a blinded manner. RESULTS: Optical density ratios > or = 2 in two or more immunoglobulin classes were seen in 43 (36%) of patients with the Guillain-Barré syndrome and in 10 (10%) of controls (odds ratio, 5.3; 95% CI, 2.4 to 12.5; P < 0.001). Increasing the optical density ratio or the number of immunoglobulin classes necessary to yield a positive result increased the strength of the association. The number of patients with the Guillain-Barré syndrome who had positive serologic responses was greatest from September to November (P = 0.02). Male patients were three times more likely to have serologic evidence of C. jejuni infection (P = 0.009); the proportion of patients with the syndrome who had a positive serologic response increased with age. CONCLUSIONS: Patients with the Guillain-Barré syndrome are more likely than controls to have serologic evidence of C. jejuni infection in the weeks before onset of neurologic symptoms. Campylobacter jejuni may play a role in the initiation of the Guillain-Barré syndrome in many patients.     

Differentiation of Campylobacter jejuni serotype O19 strains from non-O19 strains by PCR

Guillain-Barré syndrome (GBS), a neurologic disease characterized by acute paralysis, is frequently preceded by Campylobacter jejuni infection. Serotype O19 strains are overrepresented among GBS-associated C. jejuni isolates. We previously showed that all O19 strains tested were closely related to one another by randomly amplified polymorphic DNA (RAPD) and restriction fragment length polymorphism analyses. RAPD analysis demonstrated a 1.4-kb band in all O19 strains tested but in no non-O19 strains. We cloned this O19-specific band; nucleotide sequence analysis revealed a truncated open reading frame with significant homology to DNA gyrase subunit B (gyrB) of Helicobacter pylori. PCR using the random primer and a primer specific for gyrB showed that in non-O19 strains, the random primer did not recognize the downstream gyrB binding site. The regions flanking each of the random primer binding sites were amplified by degenerate PCR for further sequencing. Although the random primer had several mismatches with the downstream gyrB binding site, a single nucleotide polymorphism 6 bp upstream from the 3' terminus was found to distinguish O19 and non-O19 strains. PCR using 3'-mismatched primers based on this polymorphism was designed to differentiate O19 strains from non-O19 strains. When a total of 42 (18 O19 and 24 non-O19) strains from five different countries were examined, O19 strains were distinguishable from non-O19 strains in each case. This PCR method should permit identification of O19 C. jejuni strains.     

Biochemical analysis of peritoneal fluid in patients with and without bacterial infection

PURPOSE: The maximum preload torque of implant prosthetic retaining screws from four manufacturers and of two alloy types was measured to determine one index of interchangeability of intersystem components. MATERIALS AND METHODS: Implant prosthetic retaining screws from four manufacturers (3i Implant Innovations Inc, West Palm Beach, FL; Impla-Med Inc, Sunrise, FL; Nobelpharma USA Inc, Chicago, IL; and Implant Support Systems Inc, Irvine, CA) and of two metal types (gold and titanium) were investigated using an in vitro simulation model. Five screws of each type were tightened down against a gold cylinder using a Tohnichi BTG-6 torque gauge (Tohnichi American Corporation, Northbrook, IL) until fracture occurred. RESULTS: The 3i Implant Innovations gold and the Nobelpharma gold were not significantly different. The 3i Implant Innovations titanium and the Impla-Med gold were able to withstand less preload torque than the 3i Implant Innovations gold and the Nobelpharma gold. The Implant Support Systems titanium was able to withstand significantly more preload torque than all of the other screws. CONCLUSIONS: Interchanging implant prosthetic retaining screws could introduce new and unknown variables that may affect the long-term survival of implant fixtures and/or the implant prostheses.     

Therapy for vaginismus: in vivo versus in vitro desensitization

OBJECTIVE: To verify the effectiveness of desensitization exercises with dilators in the treatment of vaginismus, while comparing 2 therapeutic variations with differing instruction procedures ("in vivo" versus "in vitro") during the desensitization exercises. METHOD: A consecutive random sample of 44 female outpatients in sexual therapy were divided into groups for either treatment on a random basis. All patients were treated until the symptoms abated on the basis of a structured therapy program. The stability of the therapeutic success was verified through follow-up interviews. RESULTS: Forty-three (97.2%) of the patients were able to have sexual intercourse after an average of 6.3 therapeutic sessions. One-third reported an increase in their sexual desire. Thirty-four of 39 patients (87.2%) would be prepared to repeat the therapy. There were no significant differences in the success and the required number of consultations for the cure between the 2 groups investigated. CONCLUSIONS: Desensitization through exercises with dilators is an effective method for treating vaginismus. The choice of instruction procedure can be left to the patient.     

Estimation of cumulative aquatic exposure and risk due to silver: contribution of nano-functionalized plastics and textiles

Products with antimicrobial effect based on silver nanoparticles are increasingly used in Asia, North America and Europe. This study presents an analysis of risk to freshwater ecosystems from silver released from these nanoparticles incorporated into textiles and plastics. The analysis is presented in four stages; (i) silver mass flow analysis and estimation of emissions, (ii) assessment of the fate of silver in a river system and estimation of predicted environmental concentrations (PECs), (iii) critical evaluation of available toxicity data for environmentally relevant forms of silver and estimation of predicted no-effect concentrations (PNECs), and (iv) risk characterization. Our assessment is based on estimated silver use in the year 2010, focusing on the Rhine river as a case study. In 2010, biocidal plastics and textiles are predicted to account for up to 15% of the total silver released into water in the European Union. The majority of silver released into wastewater is incorporated into sewage sludge and may be spread on agricultural fields. The amount of silver reaching natural waters depends on the fraction of wastewater that is effectively treated. Modeled PECs in the Rhine river are in satisfactory agreement with monitoring data from other river systems. Because a complete characterization of the toxicity of environmentally relevant silver species is lacking, only a limited risk assessment is possible at this time. However, our study indicates that PEC/PNEC ratios greater than 1 cannot be ruled out for freshwater ecosystems, in particular sediments. No risk is predicted for microbial communities in sewage treatment plants.     

Chemoselective Hydrogenation of α,β‐Unsaturated Nitriles

The chemoselective hydrogenation of cinnamonitrile to 3‐phenylallylamine proceeds with up to 80% selectivity at conversions of >90% with Raney cobalt and up to 60% selectivity with Raney nickel catalysts. Best results were obtained with a doped Raney cobalt catalyst (RaCo/Cr/Ni/Fe 2724) in ammonia saturated methanol at 100 °C and 80 bar. Major problems are the formation of hydrocinnamonitrile and of secondary amines, and overreduction to 3‐phenylpropylamine. Important parameters are the catalyst type and composition, the solvent type and the presence and concentration of ammonia. The catalytic system tolerates functional groups like OH, OMe, Cl, CO, but not aromatic nitro groups. Preliminary experiments indicate that other unsaturated nitriles with di‐ or trisubstituted CC bonds are also suitable substrates.     

Heterogeneous Enantioselective Hydrogenation of Activated Ketones Catalyzed by Modified Pt‐Catalysts: A Systematic Structure‐Selectivity Study

A systematic structure‐selectivity study was carried out for the enantioselective hydrogenation of activated ketones with chirally modified Pt/Al₂O₃ catalysts. For this, 18 modifiers containing an extended aromatic system able to form a strong adsorption complex with the Pt surface, and a suitable chiral group with an amino function capable to interact with the keto group of the substrate ( HCd, Qd, HCn, Qn , and semi‐synthetic derivatives, as well as synthetic analogues) were prepared and tested on 8 different activated ketones in AcOH and toluene under standard conditions. It was found that relatively small structural changes of the substrate and/or modifier structures strongly affected the enantioselectivity, and that no “best” modifier exists for all substrates. The highest ees for all substrates were obtained with quinuclidine‐derived modifiers in combination with naphthalene or quinoline rings, either in AcOH (substrates 1 – 5 and 8 , all carrying an sp³ carbon next to the keto group) or toluene ( 6 and 7 , with an sp² carbon next to the ketone). The presence and nature of the substituent R' at the quinuclidine significantly affected the ee (positive and negative effects). Certain combinations of an aromatic system and an amino function were preferred: For the quinuclidine moiety, quinoline and to a somewhat lesser extent naphthalene were a better match, while for the pyrrolidinylmethyl group anthracene was better suited. Methylation of the OH group often had a positive effect for hydrogenations in AcOH but not in toluene. With the exception of 8 , higher ees were obtained for the Cd / Qn series [leading to (R)‐products] than for the Cn / Qd series [leading to (S)‐products]. In several cases, opposite structure‐selectivity trends were detected when comparing reactions in toluene and AcOH, indicating a significant influence of the solvent.