Complement-independent adherence of Escherichia coli to complement receptors in vitro.

We studied adherence to human cells by a strain of Escherichia coli. Adherence to erythrocytes was assessed directly by phase-contrast microscopy and indirectly by hemagglutination; adherence to peripheral blood leukocytes, using radiolabeled bacteria and subsequent determination of leukocyte-associated radioactivity; and adherence to renal glomeruli, by microscopy of fluoresceinated bacteria and of Gram-stained nonfluoresceinated bacteria. In serum-free systems, E. coli of this strain adhered to human erythrocytes, which have surface receptors for the third component of complement (C3), but not to erythrocytes from species lacking this receptor. 1 mM trypan blue, a reagent that inhibits complement receptor function, inhibited adherence to human erythrocytes, as well as adherence to leukocytes and glomeruli. Preincubation of erythrocytes and leukocytes with complement-coated zymosan particles partially blocked subsequent bacterial adherence. Incubation of human erythrocytes with aging human serum, with trypsin-cleaved C3, or with C3 cleaved by the classical pathway convertase (EAC142)-all of which treatments deposited C3 on the erythrocyte surface, presumably at C3 receptors-inhibited subsequent E. coli adherence. Finally, incubation of E. coli with rabbit antiserum to human C3 blocked adherence to erythrocytes.Bacterial hemagglutination and erythrocyte adherence were not inhibited by mannose in concentrations up to 2.5%. And this strain of E. coli did not adhere to or agglutinate guinea pig erythrocytes, the usual test particle used for demonstration of common pili. Finally, electron microscopy of adherent bacteria showed only rare surface pili. In contrast, adherence to and agglutination of guinea pig erythrocytes by a stock piliated E. coli was inhibited by mannose but not by trypan blue. We conclude that organisms of this strain of E. coli adhere to human erythrocytes, leukocytes, and glomeruli at complement receptors. Complement is not required for this interaction. Adherence apparently involves a C3-like structure on the bacterial surface, but bacterial surface pili play no role. The physiological or pathological role of this adherence is not apparent, but study of this phenomenon may elucidate functions of complement receptors on various cells.

Point mutations identify a conserved region of the saccharomyces cerevisiae AFR1 gene that is essential for both the pheromone signaling and morphogenesis functions.

Mating pheromone receptors activate a G protein signal pathway that leads to the conjugation of the yeast Saccharomyces cerevisiae. This pathway also induces the production of Afr1p, a protein that negatively regulates pheromone receptor signaling and is required to form pointed projections of new growth that become the site of cell fusion during mating. Afr1p lacks strong similarity to any well-characterized proteins to help predict how it acts. Therefore, we investigated the relationship between the different functions of Afr1p by isolating and characterizing seven mutants that were defective in regulating pheromone signaling. The AFR1 mutants were also defective when expressed as fusions to STE2, the alpha-factor receptor, indicating that the mutant Afr1 proteins are defective in function and not in co-localizing with receptors. The mutant genes contained four distinct point mutations that all occurred between codons 254 and 263, identifying a region that is critical for AFR1 function. Consistent with this, we found that the corresponding region is very highly conserved in the Afr1p homologs from the yeasts S. uvarum and S. douglasii. In contrast, there were no detectable effects on pheromone signaling caused by deletion or overexpression of YER158c, an open reading frame with overall sequence similarity to Afr1p that lacks this essential region. Interestingly, all of the AFR1 mutants showed a defect in their ability to form mating projections that was proportional to their defect in regulating pheromone signaling. This suggests that both functions may be due to the same action of Afr1p. Thus, these studies identify a specific region of Afr1p that is critical for its function in both signaling and morphogenesis.

Isolation of Mycoplasma pneumoniae from synovial fluid samples in a patient with pneumonia and polyarthritis.

A patient with a long history of arthritis developed pneumonia. Two weeks into her hospital course, the patient developed effusions in her knee and wrist that yielded cultures positive for Mycoplasma pneumoniae. To our knowledge, this is the third reported case of M pneumoniae isolation from a joint and the first report of isolation of M pneumoniae from two joints in a patient without hypogammaglobulinemia. The evidence suggests that in individuals with atypical pneumonia and joint effusions, M pneumoniae should be considered as a source of infection.

Successful treatment of valproic acid overdose with hemodialysis.

A 43-year-old woman took a large amount of depakote (divalproex, a slow-release form of valproate), became comatose, and developed severe hypotension refractory to fluid resuscitation and high-dose vasopressors. The serum valproic acid (VPA) concentration on admission was 1,380 microgram/mL (therapeutic range, 50 to 100 microgram/mL). She also had metabolic acidosis, thrombocytopenia, and normal renal and liver functions. Hemodialysis was initiated 4 hours after presentation. After 6 hours of hemodialysis with a high-flux dialyzer, her serum VPA concentration decreased from 940 microgram/mL to 164 microgram/mL, coincident with improvement in clinical status. The half-life of VPA was reduced to 2.4 hours with hemodialysis, whereas it was 7.2 hours before the procedure. Hemodialysis could be a valuable therapeutic intervention in VPA toxicity.

Osteopetrosis: a scanning electron microscopic study.

Scanning electron microscopic investigation was conducted with bone in a case of osteopetrosis by comparing it with normal cortical bone. The fractured surface of the osteopetrotic bone was devoid of the orderly constructed lamellar haversian system seen in normal bone. It was occupied by a massive smooth cartilaginous matrix containing scattered rough areas of abnormal ossification. Tortuous channels were randomly distributed and corresponded to the abortive marrow spaces. The presence of many irregular fracture lines reflected the fragility of the bone. The findings support the concept of defective remodeling in the pathogenesis of osteopetrosis and provide a further explanation for the abnormal fragility of bone in osteopetrosis.

New approach to patency and flow assessment after left internal thoracic artery hypoperfusion syndrome with additional saphenous vein graft to the left anterior descending artery with phase-contrast magnetic resonance angiography.

OBJECTIVE: Perioperative and early postoperative flow reduction of a left internal thoracic artery conduit is a rare complication of myocardial revascularization and may lead to the potentially fatal left internal thoracic artery hypoperfusion syndrome. It has been advocated that an additional vein graft be placed to the distal left anterior descending artery to provide sufficient myocardial perfusion. Some evidence exists, however, that this high-flow vein might lead to competing or even backward flow through the internal thoracic artery. METHODS: In the past 2 years, 21 patients received an additional vein graft to the distal left anterior descending artery for left internal thoracic artery hypoperfusion syndrome. Nineteen of these patients were available for magnetic resonance imaging. Early (< 6 months) and late (> 12 months) postoperative flow measurements, both in the left internal thoracic artery and in the saphenous vein grafts, were performed by means of conventional and a segmented k-space phase-contrast magnetic resonance angiography technique. RESULTS: Early magnetic resonance examinations indicated that all conduits had adapted to the coronary flow type with predominant diastolic perfusion. Patency rate both at the early and at the late study was 100%. No concurrent flow, flow reversal, or steal phenomena were observed. Mean flow rates were 49.2 ml/min for the left internal thoracic artery and 72.6 ml/min for the saphenous vein graft. CONCLUSION: On the basis of the flow data obtained with magnetic resonance angiography, the use of an additional saphenous vein graft as the treatment of choice in left internal thoracic artery hypoperfusion syndrome does not lead to occlusion of the artery. Conduit flow adaptation to the diastolic predominance occurs in the first 6 months after operation.

A randomized, placebo-controlled study to evaluate the role of salmeterol in the in-hospital management of asthma.

STUDY OBJECTIVES: To assess the safety and efficacy of salmeterol xinafoate as an adjunct to conventional therapy for the in-hospital management of acute asthma. DESIGN: A prospective, double-blind, randomized placebo-controlled trial. SETTING: Medical wards of a large university-based hospital. PATIENTS: Forty-three patients admitted for an acute exacerbation of asthma. INTERVENTIONS: Salmeterol (42 microg) or two puffs of placebo every 12 h in addition to standard therapy (short-acting beta-agonists, corticosteroids, and anticholinergic agents). RESULTS: No clinically adverse effects were seen with the addition of salmeterol to conventional therapy. After salmeterol, there was no difference in pulse, respiratory rate, oxygen saturation by pulse oximetry, severity of symptoms, or dyspnea score. Patients receiving salmeterol had greater FEV(1) percent improvements than the placebo group at 12, 24, 36, and 48 h. These findings were not statistically significant. By paired Student's t tests, there were significant improvements in FEV(1) (p = 0.03) and FVC (p = 0.03) in the salmeterol group after 48 h of treatment with no comparable improvement in the placebo group. In a subgroup analysis of patients with an initial FEV(1) < or = 1.5 L, the absolute FEV(1) percent improvement for salmeterol vs placebo was 51% vs 16% at 24 h and 54% vs 40% at 48 h. The relative FEV(1) percent improvement for salmeterol vs placebo was 17% vs 8% at 24 h and 18% vs 14% at 48 h. CONCLUSION: The addition of salmeterol to conventional therapy is safe and may benefit hospitalized patients with asthma. Further studies are needed to clarify its role in the treatment of acute exacerbation of asthma.

Kidney transplantation in diabetic patients using cyclosporine. Five-year follow-up.

OBJECTIVE: To review our center's experience with kidney transplantation in diabetic recipients; specifically, to compare long-term (5-year) patient and graft survival rates between diabetic and nondiabetic recipients overall and according to donor source using cyclosporine-based immunosuppression. DESIGN: A retrospective review of all kidney transplants performed over the 7-year period from 1987 to 1993. SETTING: A large urban tertiary care referral center with a long history of kidney transplantation and care of the diabetic patient. PATIENTS: All patients receiving a kidney transplant, either alone or simultaneously with a pancreas transplant, were reviewed. MAIN OUTCOME MEASURES: Actuarial patient and graft survival, serum creatinine levels, and causes of late graft loss. RESULTS: There was no significant difference in actuarial 5-year patient or kidney graft survival between diabetic and nondiabetic recipients overall or when analyzed by donor source. There was no significant difference in mean serum creatinine levels at 5 years between diabetic and nondiabetic recipients overall or between diabetic and nondiabetic cadaveric recipients. While chronic rejection was the major cause of late graft loss in nondiabetic recipients, death with a functioning graft, principally due to cardiovascular disease, was the major cause of graft loss in diabetic recipients. CONCLUSIONS: With cyclosporine-based immunosuppression, diabetic kidney transplant recipients have 5-year patient and graft survival rates and allograft function comparable to nondiabetic recipients. Given the high mortality of diabetic patients receiving dialysis, kidney transplantation is the treatment of choice for end-stage diabetic renal disease.

Specific red cell adherence test applied to tumors of ureter and renal pelvis.

The specific red cell adherence (SRCA) test used previously as a prognostic indicator of bladder tumors was used in a retrospective review of 14 patients with transitional cell carcinoma of the ureter and renal pelvis. SRCA-positive individuals appear to have better survival and progress less frequently to metastatic disease. Of five patients with positive reactions, none had distant metastases. Conversely, in SRCA-negative individuals metastatic disease developed more frequently (4 of 9). The SRCA test can be as useful a test of the prognosis of ureteral and renal pelvis tumors as it is of urinary bladder tumors.

Infection and papillary necrosis. Scanning electron microscopic comparison with bladder infection.

A case of papillary necrosis in a diabetic patient with Escherichia coli urinary tract infection is reported. Infectious contribution to the disease is presented, and the electron microscopic similarities of bladder response to infection are discussed.

Serum and urinary immunoglobulin in the rat model of acute urinary tract infection.

Total levels of urine and serum immunoglobulin IgM, IgG and IgA, and the E. coli-specific bacterial immunoglobulin response were determined by enzyme-linked immunosorbent assay (ELISA) in a rat model of acute urinary tract infection. High levels of urinary IgM were detected as early as day 3 post infection and then decreased to statistically insignificant levels. Peak levels of IgG occurred in the serum and urine on day 14. Urine and serum IgA levels remained low throughout the study period. The results demonstrate that in the rat model of acute urinary tract infection, IgM appears first in the urine and serum, and rapidly decreases. IgG then appears in the serum and urine followed by a late E. coli-specific immunoglobulin serum and urine response. Also, a non-specific component of the immunoglobulin response was noted in both the serum and urine. In the rat, IgA appears to play little or no role in the urine or in the serum response to the infection.

Serial myoglobin levels for patients with possible myocardial infarction.

OBJECTIVES: To determine the sensitivity and specificity of a new myoglobin assay for acute myocardial infarction (AMI), considering both the total amount of serum myoglobin and its percentage change over 2 hours. METHODS: A prospective, observational test performance study for the recognition of AMI was done using serial myoglobin assays of 42 admitted chest pain patients at a large, urban teaching hospital ED. Myoglobin testing was performed at presentation (time 0) and at 1 and 2 hours after arrival. A myoglobin level > 100 micrograms/L (ng/mL) or a change > or = 50% from baseline (increase or decrease) any time during the 2-hour period was considered positive. Patients and their physicians were blinded to the myoglobin results. The managing clinician's final diagnosis of the presenting event was used as the diagnostic criterion standard. RESULTS: The sensitivity of the myoglobin technique for detection of AMI in the first hours in the ED was 13/14 (93%; 95% CI: 66-100%). The 1 patient who had a false-negative test had evidence of AMI on the ECG and an initially abnormal creatine kinase-MB (CK-MB) assay. The specificity was 22/28 (79%; 59-92%). However, of the 6 patients who had "false-positive" myoglobin tests, all had serious illness: significant cardiac disease (n = 4), in-hospital death (n = 1), or deep venous thrombosis (n = 1). CONCLUSION: Myoglobin level determinations are sensitive tests to detect AMI during the first 2 hours of a patient's stay in the ED and may complement current clinical tools.

Inflammatory mediators induce sequestration of VE-cadherin in cultured human endothelial cells.

The mechanisms through which inflammatory mediators modify endothelial junctional structure are not well understood. Endothelial cells exposed to 1 mM H2O2, 0.1 mM histamine or 4 mM EDTA displayed decreased amounts of VE-cadherin on the cell surface in a time-dependent manner. H2O2 and EDTA-treated cells showed a sustained reduction in surface VE-cadherin, but histamine (0.1 mM) decreased cell surface VE-cadherin only at 5 and 15 min, not at 30 and 60 min. Sequestering of VE-cadherin could also be visualized as a decrease in immunofluorescent labeling of endothelial junctions in fixed, non-extracted monolayers. However, junctional staining was observed in these cells after membrane extraction. This decreased surface expression of VE-cadherin was actin-filament, but not PKC/MAP kinase dependent. VE-cadherin binding to the cytoskeleton was decreased by EDTA, but was not diminished by histamine or H2O2. Therefore, by promoting sequestration of junctional cadherins, inflammatory mediators may decrease adhesive bonds between apposed endothelial cells and increase solute permeability.

[Virtual intravascular endoscopy in the renal arteries: a new way of observing 3-D-MIR angiography data sets]. / Virtuelle intravasale Endoskopie in den Nierenarterien: Eine neuartige Betrachtungsform von 3-D-MRA-Datensätzen.

PURPOSE: To determine the potentials and limitations of a recently developed algorithm for virtual intravascular endoscopy (VIE) based on 3-dimensional (3-D) magnetic resonance (MR) data sets. METHOD: The data from 6 patients derived from gadolinium-enhanced MR angiography of the renal arteries were reviewed. All patients had unilateral or bilateral renal arterial pathologies (stenoses n = 2, aneurysms n = 4). Imaging was performed on a 1.5-T scanner using a 3-D gradient-echo MR sequence. The imaging parameters were as follows: TR/TE/flip angle 3.9/1.9/40 degrees, matrix 256 x 192, slice thickness 1.5 to 2 mm, FOV 32 cm, and 48 slices. Image acquisition time was 28 seconds under apnoeia conditions. A total of 60 ml 0.5 molar Gd-DTPA was injected during the scan. RESULTS: 3-D data sets could be obtained in all patients and postprocessed for VIE. The intraluminal vessel wall was depicted with high clarity in all cases. All pathologies that were not intraparenchymal could be easily seen. Limitations to the technique include the image quality of the original data set, use of the ideal threshold to minimise intraluminal artifacts, and a complicated prescription sequence. CONCLUSIONS: We have shown that VIE can be consistently performed in the renal arteries using MR data sets acquired with a contrast enhanced 3-D gradient-echo technique. It provides a hitherto unused approach to viewing 3-D vascular MR data sets.

The effect of unilateral testicular torsion on the contralateral testicle in prepubertal Chinese hamsters.

Recent studies of experimental testicular torsion in rats, rabbits, and guinea pigs have demonstrated conflicting evidence regarding contralateral testicular damage. Those studies in which cellular damage has been found are postulated to result from an immunological mechanism whereby the blood-testis barrier is disrupted with subsequent autoantibody formation. In this study, the histologic and immunologic effects of testicular torsion on the contralateral testicle were investigated in prepubertal Chinese hamsters. Four study groups were established; (1) Left orchiectomy only, (2) sham surgery (scrotal incision), (3) 720 degrees left testicular torsion with left orchiectomy 24 hours later, (4) 720 degrees torsion of left testicle with detorsion after 24 hours. The initial procedure was performed at 1 month of age with subsequent biopsies of the contralateral testicle at 1 week, 1 month, and 6 months after the initial procedure. Testicular tissue was examined for immunofluorescent activity using fluorescent labeled goat anti-hamster IgG. Positive controls were established by rabbit immunization (rabbit anti-hamster immunoglobulin) which was subsequently combined with fluorescent labeled goat antirabbit IgG. There was no appreciable difference in immunologic activity between control and experimental animals. Representative sections were examined histologically and no tubular damage was demonstrated and active spermatogenesis was noted at 6 months in all groups. We believe that our results support the premise that testicular torsion in the prepubertal period has no effect on the contralateral testicle.

Ultrastructure of Sarcocystis sporocysts from passerine birds and opossums: comments on classification of the genus Isospora.

Sporocysts were obtained from the feces of opossums (Didelphis virginiana) which had been fed muscles of passerine birds (Molothrus ater and Cassidix mexicanus) infected with Sarcocystis. Sporocysts were examined by phas microscopy and scanning and transmission electron microscopy. Ridges on the surface of the sporocysts outlined four plates. Thin sections of the sporocyst wall showed thickened regions and gaps interpreted as cross sections of the ridges. The sporocyst wall has four major layers with a thick, granular inner layer which resembles the inner layer of sporocysts of related species. Excystation structures are discussed as a basis for classifying disporocystic coccidia to correlate with Frenkel's (1977) life cycle classification of this group.

Scanning electron microscopy of alcohol-fixed cytopathology specimens.

Cells in specimens fixed in alcohol and stained by the Papanicolaou method for routine cytodiagnosis were subsequently studied by scanning electron microscopy (SEM) to determine if they manifested topologic features described in specimens prepared for optimal SEM observation. In normal bronchial washings, ciliated columnar cells were obvious, and microridges were detected in several squamous cells. Microvilli, although sometimes coarse and blunted, were present in cells of adenocarcinoma, squamous carcinoma and malignant mesothelioma in fluid specimens. Benign histiocytes in bronchial washings, neuroblastoma cells in a smear of bone marrow aspirate and lymphocytic lymphoma cells in spinal fluid had ruffled surfaces. Should topologic features prove to be diagnostically significant, SEM may be of value in further studying equivocal specimens even though they were previously prepared for routine light microscopic observation.

Phytophotodermatitis: the other "lime" disease.

Phytophotodermatitis is a skin eruption that occurs after contact with photosensitizing compounds in plants and exposure to UV light. There are two common presentations of phytophotodermatitis. Acutely, erythema and vesiculation similar to a severe sunburn are noted. After resolution of the inflammation, the involved skin has marked hyperpigmentation. Many plants have been identified that contain furocoumarins (psoralens), including limes, lemons, and celery. We present a patient with an acute phototoxic eruption and hyperpigmentation after contact with limes during a beach vacation.

Combined effects of hyperbaric oxygen and antifungal agents on the growth of Candida albicans.

The effects of hyperbaric oxygen (HBO) and antifungal agents on Candida albicans were studied. Growth curves at O2 tensions of 160 mm Hg, 900 mm Hg, and 1800 mm Hg for prolonged exposures showed no effect of pressure alone. There was a significant dose response to increasing O2 tension; growth inhibition occurred at 900 mm Hg O2 and killing at 1800 mm Hg O2. Minimum inhibitory concentrations (MIC) and minimum cidal concentrations (MCC) at 160 and 900 mm Hg O2 were done using amphotericin B, nystatin, clotrimazole, miconazole, ketoconazole and 5-fluorocytosine. MIC and MCC's were done with amphotericin B at 90-min exposures to 1800 mm Hg O2. There was no enhancement of MIC or MCC at 900 mm Hg O2. However, ketoconazole was ineffective at killing at 900 mm Hg O2 indicating a protective effect of HBO with this drug. Oxygen tensions of 1800 mm Hg for 90 min in the presence of amphotericin B showed an enhancement of both MIC and MCC. Closer quantitation of this effect upon the in vitro growth and survival of the organism showed an additive but not synergistic effect.