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Biomedical subjects

J A Jordan

Publications and source records attributed to J A Jordan.

At least 19 recordsLinked to original sources
PubMed2002

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.

Antibodies, Monoclonal↗
PubMed2001

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.

Acute Disease↗
PubMed2001

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.

Clinical Competence↗
PubMed2001

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.

Animals↗
PubMed2001

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.

CD3 Complex↗
PubMed2001

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.

Animals↗
PubMed2000

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.

Animals↗
PubMed2000

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.

Adult↗
PubMed2000

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.

Adolescent↗
PubMed2000

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.

Aged↗
PubMed2000

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.

Antibodies, Viral↗
PubMed2000

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.

Bacteremia↗
PubMed1999

Techniques for improving ear definition in microtia reconstruction.

Surgeons involved in microtia repair recognize the difficulty in creating a natural appearing ear. One key to successful reconstruction is to provide sufficient relief between the helix, scaphoid fossa and antihelix to create the illusion of thin skin overlying thin cartilage. Problems such as thick skin, hair-bearing skin and poor-quality cartilage serve to frustrate the surgeons attempt to achieve the desired result. Surgical techniques to improve cartilaginous framework definition in microtia repair are discussed.

Cartilage↗
PubMed1999

Regulation of acute lung inflammatory injury by endogenous IL-13.

Using IgG immune complex deposition to trigger acute lung inflammation in rats, we have previously shown that exogenously administered IL-13 suppresses the acute inflammatory response. In the same model, expression of both mRNA and protein for IL-13 has now been detected. Treatment of rats with Ab to IL-13 accentuated the inflammatory response, with significant increases in lung vascular permeability and in the number of neutrophils in bronchoalveolar lavage fluids. In the presence of anti-IL-13, activation of the transcription factor, NF-kappaB, was significantly increased in lung. In addition, anti-IL-13 caused significant increases in bronchoalveolar lavage levels of TNF-alpha, macrophage inflammatory protein-2, and cytokine-inducible neutrophil chemoattractant but no changes in lung vascular ICAM-1. These data suggest that during lung inflammation endogenous IL-13 regulates NF-kappaB activation and related cytokine/chemokine generation, all of which determines the intensity of the lung inflammatory response.

Acute Disease↗
PubMed1999

Inhibition of NF-kappaB activation and augmentation of IkappaBbeta by secretory leukocyte protease inhibitor during lung inflammation.

In earlier experiments, exogenous administration of secretory leukocyte protease inhibitor (SLPI) suppressed acute lung injury induced by deposition of IgG immune complexes. In the current studies we examined the mechanism of the protective effects of SLPI in this model. The presence of SLPI in the IgG immune complex-model of lung injury reduced the increase in extravascular leakage of 125I-albumin, the intensity of up-regulation of lung vascular intercellular adhesion molecule-1, and the numbers of neutrophils accumulating in the lung. The presence of SLPI caused greatly reduced activation (ie, nuclear translocation) of the transcription nuclear factor-kappaB (NF-kappaB) in lung cells but did not suppress activation of lung mitogen-activated protein kinase. SLPI did not alter NF-kappaB activation in alveolar macrophages harvested 30 minutes after initiation of lung inflammation. In the presence of SLPI, content of tumor necrosis factor-alpha, CXC chemokines, and C5a in bronchoalveolar fluids was unaffected. In the inflamed lungs, inhibition of NF-kappaB activation by SLPI was associated with elevated levels of lung IkappaBbeta (but not IkappaBalpha) protein in the absence of elevated mRNA for IkappaBbeta. When instilled into normal lung, SLPI also caused similar changes (increases) in lung IkappaBbeta. Finally, in the lung inflammatory model used, the presence of anti-SLPI caused accentuated activation of NF-kappaB. These data confirm the anti-inflammatory effect of SLPI in lung and point to a mechanism of anti-inflammatory effects of SLPI. SLPI appears to function as an endogenous regulator of lung inflammation.

Animals↗
PubMed1999

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.

Animals↗
PubMed1999

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.

Animals↗