Vaginal swabs are the specimens of choice when screening for Chlamydia trachomatis and Neisseria gonorrhoeae: results from a multicenter evaluation of the APTIMA assays for both infections

BACKGROUND

Vaginal swabs were recently U.S. Food and Drug Administration-cleared for detecting Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) using Gen-Probe Incorporated's APTIMA COMBO2 Assay (AC2). We assessed the APTIMA CT Assay (ACT) for CT, APTIMA GC Assay (AGC) for GC, and AC2 for both organisms using patient- and clinician-collected vaginal swabs.

METHOD

Women attending family planning, obstetrics and gynecology, or sexually transmitted disease (STD) clinics had first-catch urines (FCUs), patient-collected vaginal swabs, clinician-collected vaginal swabs, and endocervical swabs tested by ACT, AGC, and AC2. A second endocervical swab and FCU were tested using BD ProbeTec (Becton Dickinson) for CT and GC. We calculated sensitivity and specificity using vaginal swabs to detect CT and GC.

RESULTS

Of 1,464 subjects enrolled, 180 had CT and 78 GC. ACT sensitivities and specificities for patient-collected vaginal swabs were 98.3% and 96.5%, respectively; for clinician-collected vaginal swabs, 97.2% and 95.2%, respectively. AGC sensitivities and specificities for patient-collected vaginal swabs were 96.1% and 99.3%, respectively; for clinician-collected vaginal swabs, 96.2% and 99.3%, respectively. AC2 results were similar. If an FCU tested positive for CT or GC, >94% of matching vaginal swabs were positive. Positive endocervical swabs showed slightly less concordance (>90% and >88%, respectively). More infected patients were identified using vaginal swabs than FCUs. With AC2, 171 CT-infected patients were identified using FCUs and 196 using patient-collected vaginal swabs. This difference was more pronounced for CT than for GC.

CONCLUSIONS

Vaginal swab specimens allowed sensitive and specific detection of CT and GC in the APTIMA assays. Vaginal swabs identified as many infected patients as endocervical swabs and more than FCUs, and may well be the specimen of choice for screening.

Real-time polymerase chain reaction for detecting bacterial DNA directly from blood of neonates being evaluated for sepsis

Speed is of the essence when evaluating an infant with symptoms consistent with sepsis. Because of the high morbidity and mortality associated with neonatal sepsis, infants receive multiple, broad-spectrum antibiotics before receiving finalized blood culture results. Incorporating an additional, reliable, yet rapid assay to detect bacteria directly from blood would facilitate timely diagnosis and appropriate care. To this end, we designed a real-time polymerase chain reaction (PCR) assay targeting the highly conserved 380 bases of 16S rDNA. DNA was extracted from whole-blood samples using a Qiagen column. The limit of detection for the TaqMan-based assay, using a Smartcycler instrument, was 40, 50, or 2000 colony-forming units per milliliter of blood (CFU/ml) of Escherichia coli, group B Streptococcus, and Listeria monocytogenes, respectively, when white blood cell counts were below 39,000/microl. Implementing this approach requires less than 4 hours for both sample preparation and real-time PCR compared with 1 to 2 days to detect growth in culture or 5 days to finalize no-growth culture results. There was an overall agreement between the results of culture and real-time PCR of 94.1% (80 of 85) in this study. These results suggest that molecular techniques can augment culture-based methods for diagnosing neonatal sepsis, especially in infants whose mothers have received intrapartum antibiotic prophylaxis.

Human parvovirus B19 VP2 empty capsids bind to human villous trophoblast cells in vitro via the globoside receptor

BACKGROUND: Pregnant women acutely infected with human parvovirus B19 (B19) may transmit the virus to the developing fetus. The mechanism whereby the virus interacts with the placenta is unknown. It is known that globoside receptor is required for successful infection of the target cells, which are the highly undifferentiated, actively dividing colony and burst-form units of the erythroid series. Globoside is present on trophoblast cells which have intimate contact with maternal blood, and may therefore serve as a potential route for B19 transmission into the fetal compartment. OBJECTIVES: The purpose of this study was to determine whether B19 VP2 capsids could bind to villous trophoblast cells in vitro and whether globoside was involved. METHODS: Binding of B19 VP2 empty capsid to first-trimester villous trophoblast cells was assessed by multiple approaches, including ICC using either biotinylated B19 VP2 empty capsid or unlabeled B19 VP2 empty capsid. Quantification of viral binding involved I125-labeled B19 VP2 empty capsid. Competition studies included excess unlabeled empty capsids or pretreatment with globoside-specific IgM antibody. RESULTS: Linear binding of B19 VP2 capsid to purified villous trophoblast cells in vitro was clearly demonstrated (R2= 0.9524). Competition studies revealed specificity of I125-labeled B19 VP2 capsid binding to villous trophoblast cells when pretreatment with either 60-fold excess unlabeled B19 capsid or globoside-specific IgM antibody took place. The results illustrated B19's ability to bind in a specific manner to globoside-containing villous trophoblast cells. CONCLUSION: We speculate that the globoside present on trophoblast cells may play a role in viral binding in vivo, which may facilitate B19 transmission across the maternal-fetal interface.

Use of pyrosequencing of 16S rRNA fragments to differentiate between bacteria responsible for neonatal sepsis

Infants admitted to neonatal intensive care units for suspicion of bacterial sepsis receive at least two broad-spectrum antibiotics for a minimum of 48 to 72 hours to cover both gram-positive and gram-negative organisms while awaiting blood culture results. On average, bacterial growth becomes detectable within 12 to 24 hours, with an additional 24 to 48 hours required for identification. We have previously described using a 16S rRNA PCR assay for screening neonatal blood for bacterial DNA. Combining PCR with DNA sequencing could prove a faster means of detecting bacteria than culture-based identification. If successful, antibiotic therapy could be appropriately tailored sooner, thus sparing infants the administration of unnecessary antibiotics. Our goal was to assess the potential of pyrosequencing to differentiate between bacteria commonly associated with neonatal sepsis. To begin, full-length sequencing of the 380-bp 16S rRNA amplicons from representative bacteria was conducted (ABI 3100) and several databases queried. These included Staphylococcus sp., Streptococcus sp., Listeria sp., and numerous gram-negative rods. The sequences from clinical isolates were identical to those present in the published databases for the same bacteria. As a result, an informative 15 bases within the 380-bp amplicon was targeted for pyrosequencing following enrichment culture and PCR amplification. A total of 643 bacterial isolates commonly associated with neonatal sepsis, and 15 PCR-positive, culture-positive neonatal whole blood samples were analyzed by pyrosequencing. Results of DNA sequencing and culture identification were compared. In summary, we were successful at using PCR and pyrosequencing together to accurately differentiate between highly diverse bacterial groups.

Factors affecting measurement of specific methanogenic activity

Specific methane production (SMP) tests have been used to determine the potential loading rate capacity of anaerobic reactors, to characterize biomass prior to its use as an inoculum for new anaerobic reactors, to detect changes in biomass activity during operation, or to assess the occurrence of toxic conditions. SMP tests also provide a basis for estimating specific methanogenic activity in mixed anaerobic cultures. SMP protocols used to date have varied widely in both procedure and objective. Tests conducted by the present authors indicated that biomass concentration, substrate type and concentration, and mixing intensity are factors that can affect the results of SMP tests.

Multicenter Study of a Rapid Molecular-Based Assay for the Diagnosis of Group B Streptococcus Colonization in Pregnant Women

BACKGROUND

Current prevention of infection due to group B Streptococcus (GBS) involves giving intrapartum antibiotics to women on the basis of either antenatal culture colonization status or presence of risk factors.

METHODS

We prospectively compared the performance characteristics of a rapid molecular diagnostic test (IDI-Strep B; Infectio Diagnostic) with culture for intrapartum GBS detection after 36 weeks' gestation in 5 North American centers during the period September 2001-May 2002. Antenatal GBS screening was done according to the usual practice of participating hospitals. Two combined vaginal/anal specimens were obtained from participants during labor by use of standard techniques and processed by the same laboratories that processed the antenatal specimens. Each swab sample was processed simultaneously by culture and with IDI-Strep B. The collected specimens were randomized for order of testing of the swab samples by culture or the rapid test.

RESULTS

Of enrolled women, 803 (91.1%) were eligible for analysis. The overall intrapartum GBS colonization rate by culture was 18.6% (range, 9.1%-28.7%). Compared with intrapartum culture, the molecular test had a sensitivity of 94.0% (range, 90.1%-97.8%), specificity of 95.9% (range, 94.3%-97.4%), positive predictive value of 83.8% (range, 78.2%-89.4%), and negative predictive value of 98.6% (range, 97.7%-99.5%). The molecular test was superior to antenatal cultures (sensitivity, 94% vs. 54%; P<.0001) and prediction of intrapartum status on the basis of risk factors (sensitivity, 94% vs. 42%; P<.0001).

CONCLUSION

Use of this test for determination of GBS colonization during labor is highly sensitive and specific and may lead to a further reduction in rates of neonatal GBS disease.

Comparison of three commercially available serologic assays used to detect human parvovirus B19-specific immunoglobulin M (IgM) and IgG antibodies in sera of pregnant women

A split-sample study was conducted to evaluate the performances of three enzyme immunoassays (EIAs) utilizing one or more conformational antigens to detect human parvovirus B19 (B19V)-specific immunoglobulin M (IgM) or IgG in the sera of 198 pregnant women. We compared EIAs available from Biotrin International, Inc. (Dublin, Ireland), Medac Diagnostika (Wedel, Germany), and Mikrogen (Martinsried, Germany). Specimens with discordant results were analyzed further using an immunofluorescence assay (Biotrin). Equivocal data accounted for close to half of all the discrepant results for both IgM and IgG, with 7 of 15 discrepant results from the Medac and Mikrogen kits involving equivocal data and the Biotrin kit giving a single equivocal result. For each specimen, a consensus was established from the four test results if agreement occurred among at least three of four results. Overall, the highest percentage of agreement with the consensus results was seen when Biotrin kits were used; 194 (100%) of 194 and 194 (99.5%) of 195 results for IgM and IgG, respectively, agreed with the consensus results. When Medac kits were used, 189 (97.4%) of 194 and 191 (97.9%) of 195 results for IgM and IgG, respectively, agreed with the consensus, and when Mikrogen kits were used, 179 (92.3%) of 194 and 193 (99%) of 195 results for IgM and IgG, respectively, agreed with the consensus. Given the consensus results, the Medac EIA appeared to generate presumed false-positive results for IgM and the Mikrogen EIA appeared to generate presumed false-positive results for IgG and IgM. In summary, the Biotrin EIAs produced far fewer equivocal results than the other assays and results of the Biotrin EIAs agreed more often with the consensus results than did those of the other commercially available EIAs for detecting B19V-specific IgM and IgG antibodies.

Apoptotic activity in villous trophoblast cells during B19 infection correlates with clinical outcome: assessment by the caspase-related M30 Cytodeath antibody

Human parvovirus B19 (B19) infection during pregnancy can result in horizontal transmission of the virus and congenital infection. The main targets for B19 replication are the erythroid precursor cell of the colony and burst forming units. The cellular receptor necessary for B19 infectivity is globoside. Other non-erythroid cells can express this receptor, including megakaryocytes, endothelial cells, cardiac myocytes and placental trophoblast cells. B19 infection of globoside-containing erythroid cells results in cell death via apoptosis. We asked whether globoside-containing placental trophoblast cells, although not permissive for complete viral replication, would show evidence of apoptotic activity as a result of B19 infection. Placentas from 26 pregnancies with documented maternal and/or congenital B19 infection, 14 with poor outcomes and 12 with good outcomes were examined for evidence of apoptosis using the caspase-related M30 Cytodeath monoclonal antibody (Mab). M30 Mab recognizes a caspase 3 directed cleavage event within cytokeratin 18, a protein widely distributed in epithelial cells, of which trophoblast cells are classified. The results of the immunohistochemical analysis revealed a significant number of M30-staining placental villous trophoblast cells from B19-complicated pregnancies with poor outcomes compared to B19-complicated pregnancies with good outcomes or the 24 age-matched controls (P< 0.001). This is the first description of an association between B19-complicated pregnancies ending in foetal death and increased apoptosis within placental villous trophoblast cells. Damage due to premature death of the protective barrier of the placental trophoblast layer may compromise its integrity and play a role in pathogenesis.

Role of IL-18 in acute lung inflammation

We have examined the role of IL-18 after acute lung inflammation in rats caused by intrapulmonary deposition of IgG immune complexes. Constitutive IL-18 mRNA and protein expression (precursor form, 26 kDa) were found in normal rat lung, whereas in inflamed lungs, IL-18 mRNA was up-regulated; in bronchoalveolar (BAL) fluids, the 26-kDa protein form of IL-18 was increased at 2-4 h in inflamed lungs and remained elevated at 24 h, and the "mature" protein form of IL-18 (18 kDa) appeared in BAL fluids 1-8 h after onset of inflammation. ELISA studies confirmed induction of IL-18 in inflamed lungs (in lung homogenates and in BAL fluids). Prominent immunostaining for IL-18 was found in alveolar macrophages from inflamed lungs. When rat lung macrophages, fibroblasts, type II cells, and endothelial cells were cultured in vitro with LPS, only the first two produced IL-18. Intratracheal administration of rat recombinant IL-18 in the lung model caused significant increases in lung vascular permeability and in BAL content of neutrophils and in BAL content of TNF-alpha, IL-1beta, and cytokine-induced neutrophil chemoattractant, whereas intratracheal instillation of anti-IL-18 greatly reduced these changes and prevented increases in BAL content of IFN-gamma. Intratracheal administration of the natural antagonist of IL-18, IL-18 binding protein, resulted in suppressed lung vascular permeability and decreased BAL content of neutrophils, cytokines, and chemokines. These findings suggest that endogenous IL-18 functions as a proinflammatory cytokine in this model of acute lung inflammation, serving as an autocrine activator to bring about expression of other inflammatory mediators.

Diagnosing human parvovirus B19 infection: guidelines for test selection

Human parvovirus B19 is the cause of a common childhood disease that usually has a mild and self-limited course. Complete viral replication and subsequent cell lysis are limited to early erythroid precursor cells expressing the globoside receptor. Individuals with shortened red blood cell half-lives and immunocompromised or immunosuppressed patients, as well as pregnant women and developing fetuses, are at risk for severe anemia and/or persistent infection from human parvovirus B19. Selection of the diagnostic test(s) to use to detect parvovirus B19 is patient dependent. Serological testing is most appropriate in immunocompetent individuals, including children and pregnant women, who have symptoms consistent with parvovirus B19 infection or a history of recent exposure. Conversely, a molecular amplification assay should be chosen to detect parvovirus B19 DNA in individuals lacking an adequate antibody-mediated immune response. In summary, it is critical that clinicians are educated about the most appropriate diagnostic test to detect parvovirus B19 infection in their patients because selecting an inappropriate or inaccurate test for parvovirus B19 can lead to misinformation and/or misdiagnosis.

TaqMan-based detection of Trichomonas vaginalis DNA from female genital specimens

A double-labeled fluorescent probe was designed and evaluated for detecting Trichomonas vaginalis DNA in a 5' nuclease (TaqMan) assay. The T. vaginalis-specific probe contains a 5'-fluorescein (5'-FAM) and a 3'-rhodamine (TAMRA) derivative. Female genital secretions were collected on Amplicor (Roche Molecular, Indianapolis, Ind.) swabs and by a transport system used for Chlamydia trachomatis and/or Neisseria gonorrhoeae DNA detection by PCR. Five hundred fifty-two female genital specimens, of which 248 (45%) were vaginal specimens and 304 (55%) were introital, were tested for both T. vaginalis DNA and viable microorganisms using the 5' nuclease assay and broth culture, respectively. Of these, 304 of 552 (55%) were also evaluated by direct microscopic examination for the characteristic motile organism. After resolving discrepancies, the comparisons produced an analytical sensitivity and specificity for the TaqMan-based PCR assay of 97.8 and 97.4%, respectively. As a result, DeltaRQ values (differences in fluorescence due to probe hybridization and resulting 5'-FAM cleavage from the specific PCR product) of > or =2.0 and < or =1.5 were established for T. vaginalis-positive and -negative cutoffs, respectively. DeltaRQ values between 1.5 and 2.0 were considered indeterminate. Overall findings revealed a high level of agreement between PCR and culture for detecting T. vaginalis. Potential benefits of the 5' nuclease assay include a greater sensitivity compared to direct microscopic examination and the ease of testing large numbers of clinical specimens in a significantly shorter turnaround time compared to culture.

Virtual reality training leads to faster adaptation to the novel psychomotor restrictions encountered by laparoscopic surgeons

BACKGROUND

The fulcrum effect of the body wall on instrument handling poses a major obstacle to the mastery of instrument coordination for junior laparoscopic surgeons. This study evaluated three types of laparoscopic simulator training to assess their ability to promote the user's adaptation to the fulcrum effect.

METHODS

Thirty-two participants with no previous experience in laparoscopic surgery were randomly assigned to one of four groups representing different training conditions. One group was assigned to use a virtual reality simulator (MIST VR); two others were given a laparoscopic Z or U maze-tracking task. The control group received no training. Subjects were asked to perform a 2-min laparoscopic cutting task under normal laparoscopic imaging conditions first before and then after training.

RESULTS

In the test trial, subjects who trained on MIST VR made significantly more correct incisions (p < 0.0001) and fewer incorrect incisions (p < 0.0001).

CONCLUSION

Training on a virtual reality simulator such as MIST VR helps laparoscopic novices adapt to the fulcrum effect faster.

Placental cellular immune response in women infected with human parvovirus B19 during pregnancy

Human parvovirus B19 can cause congenital infection with variable morbidity and mortality in the fetus and neonate. Although much information exists on the B19-specific antibody response in pregnant women, little information is available describing the cell-mediated immune (CMI) response at the maternal-fetal interface. The focus of this study was to characterize the CMI response within placentas from women who seroconverted to B19 during their pregnancies and compare it to controls. Immunohistochemical techniques were used to identify the various immune cells and the inflammatory cytokine present within placental tissue sections. Group 1 consisted of placentas from 25 women whose pregnancies were complicated by B19 infection; 6 women with good outcome (near-term or term delivery), and 19 with poor outcome (spontaneous abortion, nonimmune hydrops fetalis, or fetal death). Group 2 consisted of placentas from 20 women whose pregnancies were complicated with nonimmune hydrops fetalis of known, noninfectious etiology. Group 3 consisted of placentas from eight women whose pregnancies ended in either term delivery or elective abortion. The results of the study revealed a statistically significant increase in the number of CD3-positive T cells present within placentas from group 1 compared to group 2 or 3 (13.3 versus 2 and 1, respectively) (P < 0.001). In addition, the inflammatory cytokine interleukin 2 was detected in every placenta within group 1 but was absent from all placentas evaluated from groups 2 and 3. Together, these findings demonstrate evidence for an inflammation-mediated cellular immune response within placentas from women whose pregnancies are complicated with B19 infection.

Nitric oxide diminishes apoptosis and p53 gene expression after renal ischemia and reperfusion injury

BACKGROUND

The role of nitric oxide in the ischemic injury of the kidney is still controversial. The aim of this study was to reevaluate the beneficial effect of exogenous nitric oxide and define its effects as regulator of gene p53 expression and apoptosis in the ischemic renal injury.

METHODS

Sprague-Dawley rats were subjected to 75 min of renal warm ischemia and contralateral nephrectomy. The animals were divided into six groups (n=6 per group): Two sham groups at 4 and 24 hr, two ischemic control (IC) at same times and two treated groups (Na-NP), studied at same intervals, where sodium nitroprusside (5 mg/kg) was given 15 min before reperfusion. The parameters evaluated included: serum creatinine, blood urea nitrogen, neutrophil infiltration determined by myeloperoxidase, gene p53 expression determined by reverse transcriptase polymerase chain reaction, apoptosis determined by peroxidase in situ technique and light histology.

RESULTS

There were significant improvements in serum creatinine and blood urea nitrogen at 24 hr in the NA-NP group when compared with the IC group (P<0.05). Myeloperoxidase levels were higher in the IC when evaluated against the Na-NP groups. Na-NP exhibited a downregulating effect in the expression of gene p53 when compared to the IC group. Apoptosis was more evident in the IC group and had moderately increased histological damage when compared to the Na-NP group.

CONCLUSIONS

Nitric oxide demonstrated a protective effect in the ischemic injury of the kidney and exerted an antiapoptotic action dowregulating the expression of gene p53.

A comparison between randomly alternating imaging, normal laparoscopic imaging, and virtual reality training in laparoscopic psychomotor skill acquisition

OBJECTIVES

To evaluate virtual reality as a laparoscopic training device in helping surgeons to automate to the "fulcrum effect" by comparing it to time-matched training programs using randomly alternating images (ie, y-axis inverted and normal laparoscopic) and normal laparoscopic viewing conditions.

METHODS

Twenty-four participants (16 females and 8 males), were randomly assigned to minimally invasive surgery virtual reality (MIST VR), randomly alternating (between y-axis inverted and normal laparoscopic images), and normal laparoscopic imaging condition. Participants were requested to perform a 2-minute laparoscopic cutting task before and after training.

RESULTS

In the test trial participants who trained on the MIST VR performed significantly better than those in the normal laparoscopic and randomly alternating imaging conditions.

CONCLUSION

The results show that virtual reality training may provide faster skill acquisition with particular reference to automation of the fulcrum effect. MIST VR provides a new way of training laparoscopic psychomotor surgical skills.

Comparison of 16S rRNA gene PCR and BACTEC 9240 for detection of neonatal bacteremia

Ten percent of infants born in the United States are admitted to neonatal intensive care units (NICU) annually. Approximately one-half of these admissions are from term infants (>34 weeks of gestation) at risk for systemic infection. Most of the term infants are not infected but rather have symptoms consistent with other medical conditions that mimic sepsis. The current standard of care for evaluating bacterial sepsis in the newborn is performing blood culturing and providing antibiotic therapy while awaiting the 48-h preliminary result of culture. Implementing a more rapid means of ruling out sepsis in term newborns could result in shorter NICU stays and less antibiotic usage. The purpose of this feasibility study was to compare the utility of PCR to that of conventional culture. To this end, a total of 548 paired blood samples collected from infants admitted to the NICU for suspected sepsis were analyzed for bacterial growth using the BACTEC 9240 instrument and for the bacterial 16S rRNA gene using a PCR assay which included a 5-h preamplification culturing step. The positivity rates by culture and PCR were 25 (4.6%) and 27 (4.9%) positive specimens out of a total of 548 specimens, respectively. The comparison revealed sensitivity, specificity, and positive and negative predictive values of 96.0, 99. 4, 88.9, and 99.8%, respectively, for PCR. In summary, this PCR-based approach, requiring as little as 9 h of turnaround time and blood volumes as small as 200 microl, correlated well with conventional blood culture results obtained for neonates suspected of having bacterial sepsis.

Comparison of a baculovirus-based VP2 enzyme immunoassay (EIA) to an Escherichia coli-based VP1 EIA for detection of human parvovirus B19 immunoglobulin M and immunoglobulin G in sera of pregnant women

A split-sample study was conducted to evaluate the clinical performance of an enzyme immunoassay that detects the human parvovirus B19 virus (B19V) immunoglobulin M (IgM) or IgG in the sera of pregnant women. The initial study compared a baculovirus-expressed VP2 enzyme immunoassay (BVP2 EIA) (Biotrin International Inc., Dublin, Ireland) with the currently available and commonly used Escherichia coli-expressed VP1 enzyme immunoassay (EVP1 EIA) (MRL Diagnostics, Cypress, Calif.). There was a high degree of agreement between the two assays in the detection of IgM antibodies (283 of 307 [92.2%]) or IgG antibodies (279 of 311 [89. 7%]), with the majority of discrepancies (IgM, 17 of 24 [71%]; IgG, 16 of 31 [50%]) being due to equivocal data obtained with the EVP1 EIA. Specimens with discordant BVP2 EIA and EVP1 EIA results (23 of 24 IgM and 32 of 32 IgG results) were analyzed further by baculovirus-based VP1 immunofluorescence assays (BVP1 IFAs) (Biotrin International). The BVP2 EIA and BVP1 IFA results for 20 of 23 and 28 of 32 specimens for IgM and IgG, respectively, were concordant. In contrast, the EVP1 EIA and BVP1 IFA data for only 3 of 23 and 4 of 32 specimens for IgM and IgG, respectively, were in agreement, despite the fact that the same capsid antigen was used. Both the BVP2 EIAs and BVP1 IFAs utilize a conformational viral capsid antigen, while the EVP1 EIA uses a denatured viral capsid antigen. In conclusion, the BVP2 EIAs produced far fewer equivocal results for IgM and IgG, correlating more closely to the confirmatory BVP IFAs, than did the EVP1 EIAs and proved to be more accurate for detecting B19V antibodies in the sera of pregnant women.

Randomly alternating image presentation during laparoscopic training leads to faster automation to the "fulcrum effect"

BACKGROUND AND STUDY AIMS

The aim of this study was to evaluate four training programmes intended to help laparoscopic surgeons automate to the "fulcrum effect".

METHODS

A total of 32 participants (16 men, 16 women), were randomly assigned to one of four different image-viewing conditions: full binocular, y-axis inverted, normal laparoscopic and randomly alternating (between y-axis-inverted and normal laparoscopic). The subjects were requested to perform 10 trials of a simple laparoscopic cutting task, each lasting 2 minutes. Each then completed a 2-minute test under normal laparoscopic imaging conditions.

RESULTS

In the final test trial, participants who trained under the randomly alternating imaging conditions (y-axis inverted and normal laparoscopic) performed significantly better than those from the other groups.

CONCLUSION

Training under a randomly alternating viewing condition helps laparoscopic trainees automate to the "fulcrum effect" faster.

Stereotastic radiosurgery for glomus jugulare tumors

OBJECTIVES/HYPOTHESIS

Surgery is considered to be the mainstay of treatment for glomus jugulare tumors. A subset of patients are poor surgical candidates based on age, medical problems, tumor size, or prior treatment failure. The purpose of this study was to review our results with stereotactic radiosurgery (gamma knife treatment) in this group of patients, with particular attention to adverse reactions and symptom relief.

STUDY DESIGN

Retrospective review and phone survey.

METHODS

Charts were reviewed for size and location of tumor, history of previous treatment, symptoms before and after treatment, amount of radiation received, acute and late complications, and functional level before and after treatment. Pre-treatment and posttreatment magnetic resonance imaging scans were also reviewed. Identified patients were then contacted for a phone interview.

RESULTS

Eight patients were identified. Phone interviews were conducted with four patients. Four patients had failed previous treatment. Follow-up ranged from 7 to 104 months. One patient experienced an acute complication: intractable vertigo requiring hospitalization. No patient experienced delayed cranial neuropathies. No patient reported worsening of any of the following symptoms: pulsatile tinnitus, hearing loss, facial weakness, hoarseness, or difficulty swallowing. Three patients reported improvement in their pulsatile tinnitus. Two patients reported improvement in hearing loss, and one patient each reported improvement in vertigo and difficulty swallowing.

CONCLUSIONS

Preliminary results suggest that stereotactic radiosurgery is useful to control symptoms and may be delivered safely in patients with primary or recurrent glomus jugulare tumors who are poor surgical candidates.

Upregulation of lung chemokines associated with hemorrhage is reversed with a small molecule multiple selectin inhibitor

BACKGROUND

Hemorrhage can modify the leukocyte-endothelial cell response leading to tissue injury. The selectin family of adhesion molecules and chemokines mediate the leukocyte-endothelial cell interaction, resulting in neutrophil sequestration and activation. This work studies whether a small molecule inhibitor of selectins can ameliorate the effect of hemorrhage on chemokine expression and neutrophil infiltration in the lung. We also aimed to assess the regulatory effect of this small molecule inhibitor of selectins in the lung functional and structural response of animals subjected to hemorrhagic shock.

STUDY DESIGN

We subjected 36 Sprague-Dawley rats to uncontrolled hemorrhagic shock for a period of 150 minutes. Three groups of animals were included (n = 12 per group)-the sham, control, and treated groups, with the latter receiving a small molecule selectin inhibitor (TBC-1269) at 25 mg/kg, which was given after tail artery transection. The following measurements were evaluated: fluid requirements during resuscitation for 150 minutes; PO2/FIO2 ratio, lung water, and lung histology, lung myeloperoxidase and lung macrophage inflammatory protein-2 (MIP-2) mRNA and cytokine induced neutrophil chemoattractant mRNA at 6 hours. Statistical analysis included Student's t-test and ANOVA.

RESULTS

There was significant improvement in lung function as expressed by PO2/FIO2 ratio and wet to dry lung water ratio in the treated group. There were no significant changes in fluid requirements between the three groups. Neutrophil infiltration, measured by tissue myeloperoxidase, was significantly (p < 0.05) decreased in the lungs of the treated animals. Lung histology was considerably improved in the treated group. The small molecule selectin inhibitor had a profound downregulating effect on macrophage inflammatory protein-2 and cytokine-induced neutrophil chemoattractant as expressed in lung tissue.

CONCLUSIONS

Our study confirms the key role that selectins play in the pathogenesis of hemorrhagic shock. The multiple selectin blockade allowed for better function and structure of the lung. The mechanism of protection may be secondary to the downregulation of chemokine expression and neutrophil infiltration.

Eotaxin expression in Sephadex-induced lung injury in rats

The CC chemokine eotaxin is a potent and specific eosinophil chemoattractant. Eosinophil-dependent tissue injury has been shown to contribute to airway inflammation such as that in asthma. In the present study, We investigated eotaxin expression in a rat model of pulmonary inflammation (featuring accumulation of eosinophils) induced by intratracheal instillation of cross-linked dextran beads (Sephadex G200). Intratracheal instillation of 5 mg/kg Sephadex caused a time-dependent eosinophil infiltration into the lung, reaching a peak at 24 hours. Eotaxin mRNA in the lung paralleled the eosinophil influx. Eotaxin protein in bronchoalveolar (BAL) fluids and lung homogenates was shown by Western blot and immunostaining to be maximally expressed by 24 hours. Sephadex-induced lung injury, as measured by (125)I-labeled albumin leakage from the pulmonary vasculature, developed in a time-dependent manner. Intravenous injection of blocking antibody to eotaxin significantly decreased eosinophil infiltration and lung permeability. These data suggest that, in the Sephadex model of lung inflammation, eotaxin up-regulation mediates intrapulmonary accumulation of eosinophils and the development of lung injury.

Fosfomycin does not inhibit the tumoricidal efficacy of cisplatinum

OBJECTIVES

This study investigates the effect of fosfomycin on the tumoricidal efficacy of cisplatinum.

STUDY DESIGN

Prospective study utilizing the FaDu squamous cell carcinoma cell line and a nude mouse tumor xenograft model.

METHODS

Tumor cell growth was assessed in vitro in the presence of cisplatinum and/or fosfomycin utilizing the MTT assay. An optimal cisplatinum dose and dosing schedule was established in a nude mouse tumor xenograft model of squamous cell carcinoma. Using this model, fosfomycin was tested at three dosages and tumor growth monitored over 4 weeks.

RESULTS

Mice treated with cisplatinum and fosfomycin had smaller tumors than those treated with cisplatinum alone (P<.01).

CONCLUSIONS

This study is the first demonstration that fosfomycin does not inhibit the tumoricidal efficacy of cisplatinum in vivo. This suggests that fosfomycin may be useful in preventing cisplatinum-induced ototoxicity and nephrotoxicity in humans without altering the tumor response rate.