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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
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↗
PubMed1999

Globoside expression within the human placenta.

This report demonstrates the presence of the neutral glycosphingolipid, globoside, on the villous trophoblast layer of human placenta. Immunoreactivity for globoside which is the receptor used by human parvovirus B19 was strongest in villous trophoblast cells of first trimester placentae, with diminished reactivity in second trimester placentae, and a near lack of staining for the antigen in those of third trimester. This relative reduction in globoside-specific immunoreactivity in placentae of increasing gestational ages was confirmed using thin-layer chromatographic analyses of extracted neutral glycolipids from the syncytiotrophoblast layer and cytotrophoblast cells of first and third trimester placental villi. The presence of globoside on the protective trophoblast layer of the villi provides a potential pathway whereby B19 may be transmitted from an infected mother to the fetus. The virus once across the placental barrier, may gain access to its erythroid precursor target cells within fetal villus capillaries. The observed change found in globoside immunoreactivity correlates well with the observation that fetal outcome is worse when maternal infection occurs during first or second trimester as compared to an infection occurring near term. The reason for this observed difference in fetal outcome may be due not only to the presence of more target cells potentially to infect during the first and second trimesters, but also to the greater number of viral receptors present on the villous trophoblast layer.

Chromatography, Thin Layer↗
PubMed1999

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.

Animals↗
PubMed1999

Regulatory effects of interleukin-11 during acute lung inflammatory injury.

The role of interleukin-11 (IL-11) was evaluated in the IgG immune complex model of acute lung injury in rats. IL-11 mRNA and protein were both up-regulated during the course of this inflammatory response. Exogenously administered IL-11 substantially reduced, in a dose-dependent manner, the intrapulmonary accumulation of neutrophils and the lung vascular leak of albumin. These in vivo anti-inflammatory effects of IL-11 were associated with reduced NF-kappaB activation in lung, reduced levels of tumor necrosis factor alpha (TNF-alpha) in bronchoalveolar lavage (BAL) fluids, and diminished up-regulation of lung vascular ICAM-1. It is interesting that IL-11 did not affect BAL fluid content of the CXC chemokines, macrophage inflammatory protein-2 (MIP-2) and cytokine-inducible neutrophil chemoattractant (CINC); the presence of IL-11 did not affect these chemokines. However, BAL content of C5a was reduced by IL-11. These data indicate that IL-11 is a regulatory cytokine in the lung and that, like other members of this family, its anti-inflammatory properties appear to be linked to its suppression of NF-kappaB activation, diminished production of TNF-alpha, and reduced up-regulation of lung vascular ICAM-1.

Animals↗
PubMed1998

Endoscopic cauterization for treatment of fourth branchial cleft sinuses.

Fourth branchial cleft sinuses are rare, and the nature of their origin is controversial. Clinical presentation is varied because they may present as asymptomatic neck masses, recurrent neck abscesses, or suppurative thyroiditis. We describe herein 7 children who presented with abscesses on the left side of their necks, 3 of whom had abscesses that involved the thyroid gland. Direct laryngoscopy revealed that all 7 children had a sinus tract opening into the apex of the piriform sinus. Endoscopic obliteration of this tract was achieved using an insulated electrocautery probe either when the abscess was initially incised and drained or 4 to 6 weeks later. All 7 children recovered uneventfully. Four of the 7 children were followed up for more than 18 months without recurrence.

Abscess↗
PubMed1998

Calcium pyrophosphate deposition disease of the temporal bone.

Massive calcium pyrophosphate crystal deposition is a rare disorder that may affect the temporomandibular joint and temporal bone. The diagnosis is difficult, and misdiagnosis as malignancy, particularly chondrosarcoma, is frequent. This can lead to unnecessarily aggressive management. The clinical, radiographic, and pathologic features of this entity are reviewed, and treatment options are discussed.

Aged↗
PubMed1998

Geriatric rhinitis: what it is, and how to treat it.

In the nose, normal physiologic changes of aging include loss of nasal tip support, atrophy of mucus-producing mucosal glands, and decreased olfaction. These changes contribute to geriatric rhinitis, the symptoms of which are often attributed by the older patient to "allergies" or "sinus trouble." An understanding of these anatomic changes, linked with a thorough history and physical examination, allows the physician to properly manage geriatric rhinitis. Medical management most often involves liquifying--not drying--nasal secretions with oral and topical preparations. Conservative surgical treatment is occasionally indicated.

Aged↗