Analysis and ultrastructural localization of Ehrlichia chaffeensis proteins with monoclonal antibodies

Ehrlichia chaffeensis, an obligately intracellular bacterium with tropism for monocytes, is the etiologic agent of human monocytic ehrlichiosis. To determine the nature and ultrastructural location of E. chaffeensis antigens, monoclonal antibodies (MAbs) to E. chaffeensis were developed. The MAbs were used for immunofluorescence and Western immunoblotting analysis of the antigens of density gradient-purified ehrlichiae. Monoclonal antibody 6A1 recognized an epitope of a 30-kD protein. This antibody reacted with a strain-specific epitope of E. chaffeensis, Arkansas strain, and did not cross-react with any other ehrlichia tested. Monoclonal antibodies 3C7 and 7C1-B recognized Arkansas strain proteins of 30 and 29 kD and reacted with E. chaffeensis (strain 91HE17) proteins of 31 and 29 kD and an E. canis protein of 30 kD. Lack of reactivity of these two MAbs with E. sennetsu and E. risticii suggests that the epitope is group-specific. Monoclonal antibody 5D11 recognized a 58-kD protein of both strains of E. chaffeensis as well as E. canis, apparently a group-specific, conformation-independent epitope. Monoclonal antibody 7C1-C reacted with 58- and 88-kD proteins of both the Arkansas and 91HE17 strains. Trypsin treatment destroyed the reactivity of E. chaffeensis antigens with all the MAbs when tested by Western immunoblotting, indicating that these antigens are proteins with trypsin-sensitive epitopes. Immunoelectron microscopy of negatively stained intact E. chaffeensis organisms showed that the 30- and 29-kD proteins are present on the surface of the ehrlichial cell wall along with the previously localized 28-kD protein.

Ligand interactions with E-selectin. Identification of a new binding site for recognition of N-acyl aromatic glucosamine substituents of sialyl Lewis X

Several N-acylglucosamine derivatives of sialyl Lewis X (1-3) were prepared using a combined chemical enzymatic approach and evaluated as an inhibitor of E-selectin-mediated cellular adhesion. Compounds with aromatic functionality, 1 and 2, were found to be 3-10 times more potent than the N-acetyl derivative (14) in an ELISA E-selectin cell adhesion assay. Conformational analysis with NMR indicated that the sialyl Lewis x domain of 1 retained the conformation of the N-acetyl derivative (14) despite the presence of the N-naphthamido group. The dramatic order of magnitude increase in potency of these monovalent structures can be utilized to design more potent selectin-based cell adhesion inhibitors.

Effect of parathyroid hormone on antioxidant enzyme activity and lipid peroxidation of erythrocytes in five-sixths nephrectomized rats

The purpose of the study was to investigate the effects of parathyroid hormone (PTH) infusion on antioxidant enzyme activity and lipid peroxidation of erythrocytes in five-sixths nephrectomized (Nx) rats. Five-sixths Nx rats had a higher osmotic fragility in red blood cells (RBC). Thyroparathyroidectomy (TPTX) effectively decreased the abnormality of osmotic fragility in RBC in Nx rats. PTH infusion in Nx-TPTX rats markedly increased the osmotic fragility in RBC. Total glutathione was measured by using the enzyme-recycling method. We found elevated glutathione levels in RBC of five-sixths Nx rats, but this elevation could be inhibited by TPTX and recovered by PTH infusion in Nx-TPTX rats. Five-sixths Nx rats had a lower glutathione peroxidase activity in RBC, but TPTX or PTH infusion was not found to alter the decrease of the glutathione peroxidase activity in RBC of five-sixths Nx rats. These rats had a higher activity in RBC superoxide dismutase as compared with sham-operated controls (p < 0.05), but the higher activity in RBC superoxide dismutase in Nx rats had been inhibited by TPTX. PTH infusion recovered the higher activity in RBC superoxide dismutase in five-sixths Nx-TPTX rats. Nx rats were not found to alter the activity of catalase in RBC. Neither could TPTX or PTH infusion in Nx rats influence the activity of catalase in RBC. A high lipid peroxidation in RBC was found in five-sixths Nx rats, namely, increased formation of malondialdehyde (MDA) in RBC had been induced to produce lipid peroxidation by H2O2, but neither TPTX nor PTH infusion could inhibit or enhance the increase of lipid peroxidation in RBC of Nx rats. These results indicate that PTH infusion did not increase the susceptibility to lipid peroxidation in RBC of five-sixths Nx rats. Thus, the increased osmotic fragility in RBC induced by PTH infusion may not result from the reduction in the RBC defense mechanism against free radical toxicity.

The impact of endoscopic variceal ligation on the pressure of the portal venous system

BACKGROUND/AIMS

Endoscopic variceal ligation is a viable substitute for injection sclerotherapy. It is still not known how endoscopic variceal ligation may influence the portal venous system. To clarify this issue we investigated the impact of endoscopic variceal ligation on the pressure of the portal venous system.

METHODS

Twenty-nine patients with a history of esophageal variceal bleeding but without ascites were enrolled. All had cirrhosis; 63% of them were post-hepatitic. Ligation was performed at intervals of 2-3 weeks until all the varices were obliterated. Portal venograms were performed before institution of ligation and after variceal obliteration to assess venographic findings and pressure changes. The pressures of the main portal vein, splenic vein and superior mesenteric vein were recorded.

RESULTS

Twenty-five patients completed the study. A mean of 4.4 sessions (range: 2-7) of ligation over a period of 2 months was needed. Seventeen (68%) patients experienced elevated pressure and eight (32%) patients reduced pressure after ligation. Mean (median) pressure changes were as follows: portal venous pressure, 26.5 +/- 4.7 (25.0) mmHg vs. 28.2 +/- 7.2 (28.0) mmHg (p > 0.05); splenic venous pressure, 28.2 +/- 4.9 (26.0) mmHg vs. 29.0 +/- 6.8 (29.0) mmHg (p > 0.05); superior mesenteric venous pressure, 28.4 +/- 6.0 (27.0) mmHg vs. 29.5 +/- 7.0 (29.0) mmHg (p > 0.05). Five patients (20%) experienced rebleeding before variceal obliteration; all of them presented elevated portal pressures after variceal obliteration. Among the eight patients with decreased portal pressure, seven (87%) had other major collaterals apart from esophageal varices, compared to three out of the 17 (18%) patients with elevated portal pressure who had other major collaterals (p < 0.01).

CONCLUSIONS

Among patients receiving endoscopic variceal ligation, 68% experienced elevated portal pressure, while 32% had decreased portal pressure. Elevation of portal pressure after variceal ligation may be an important factor in variceal rebleeding. The presence of other major collaterals apart from esophageal varices may be responsible for the decrease in portal pressure after obliteration of esophagel varices.

Ultrastructural variation of cultured Ehrlichia chaffeensis

The ultrastructure of Ehrlichia chaffeensis (Arkansas strain) was studied in non-irradiated and irradiated monolayers of mouse embryo, Vero, BGM and L929 cells, and in non-irradiated DH82 cells. Within the intracellular parasitophorous vacuoles (morulae), two types of ehrlichial cells were found regularly--those with uniformly dispersed nucleoid filaments and ribosomes (dense-cored cells), which represent the normal life cycle of ehrlichiae. In addition, large reticulate cells were observed, forming long projections of the cell wall, protrusions of cytoplasmic membrane into the periplasmic space, or budding of protoplast fragments (minute forms) into the periplasmic space. Ehrlichiae with abnormalities of protoplast fission were found, apparently leading to formation of giant, multilobular or elongated rod-like ehrlichiae. Morulae were usually surrounded by cisterns of granular endoplasmic reticulum and mitochondria and often contained vesicles, long tubules 25nm in diameter, probably originating from the ehrlichial cell wall, and fibrillar ehrlichial antigen apparently shed from the surface of the cell wall. Some cells contained, in addition to normal morulae, a whole morula that had become dense and contained degenerating ehrlichiae. These results indicate that as well as normal growth and reproduction, ehrlichiae exhibit pathological events: they can be remarkably damaged inside the host cell vacuoles, presumably phagolysosomes, or enter a process morphologically similar to bacterial L-transformation.

A study of different postures on isometric lifting strength in normal college students

The purpose of this study was to describe norms of isometric lifting strength for normal college students and to investigate the effects of gender, body weight, height, and upper and lower limb length on lifting strength. Three types of lifting (i.e., arm, back, and leg lifting) were measured in a sample of 104 college students aged between 18 and 26 years. A Force Evaluation and Testing System (FET 5000) was used for strength measurements with three standard lifting positions. The average of three trials for each lifting strength test was used as the subject's test score. The results showed that the highest mean lifting strength was recorded for leg lifting in both males and females. Both groups also had the lowest score in arm lifting. Of the total sample, there was a difference of strength of nearly three- times between leg and arm lifting. Males were stronger than females in all lifting patterns. In addition, lifting strengths were significantly affected by such variables as sex, weight and height. Body weight was an effective predictor of arm lifting strength, and height an effective predictor of leg lifting strength. Finally, we found that strength in one position had positive relations with strength in other positions. These findings and the establishment of data base can in future provide therapists with an objective evaluation regarding lifting strength of individuals for clinical use.

A prospective, randomized trial of sclerotherapy versus ligation in the management of bleeding esophageal varices

We conducted a prospective, randomized trial comparing sclerotherapy and ligation in 120 patients with acute bleeding of esophageal varices. All the patients were cirrhotic, 59 received sclerotherapy, and 61 received ligation. Treatment was repeated regularly until the varices were obliterated. The mean follow-up period was 295 +/- 120 days and 310 +/- 105 days for the sclerotherapy and ligation groups, respectively. The control of active bleeding was 12/15 (80%) in the sclerotherapy group and 18/19 (94%) in the ligation group (P = .23). The numbers of treatment sessions required to achieve variceal obliteration were 6.5 +/- 1.2 in the sclerotherapy group and 3.8 +/- 0.4 in the ligation group (P < .001). Recurrent bleeding from the gastrointestinal tract was 51% in the sclerotherapy group compared with 33% in the ligation group (P < .05). Recurrent bleeding from esophageal varices was 36% in the sclerotherapy group and 11% in the ligation group (P < .01). However, bleeding from ectopic varices and congestive gastropathy was less common in the sclerotherapy group (7%) than in the ligation group (18%) (P = .05). Significant complications were encountered in 19% of the sclerotherapy group and in 3.3% of the ligation group (P < .01). Comparison of Kaplan-Meier estimates of time to death of both groups showed a significantly lower mortality in the ligation group (P = .011). Both sclerotherapy and ligation can effectively arrest active bleeding from esophageal varices. However, ligation is more effective than sclerotherapy in decreasing the risk of rebleeding from esophageal varices with fewer complications. Ligation can also achieve obliteration of esophageal varices more rapidly than sclerotherapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Isolation and characterization of a new strain of Ehrlichia chaffeensis from a patient with nearly fatal monocytic ehrlichiosis

Ehrlichia chaffeensis is the causative agent of human monocytic ehrlichiosis, a disease that ranges in severity from asymptomatic infection to death. Only one isolate of E. chaffeensis has been made, the Arkansas strain, upon which all characterizations of the agent of human monocytic ehrlichiosis have been based. We report the isolation and characterization of a new strain of E. chaffeensis, the 91HE17 strain, which was cultivated from a patient with a nearly fatal illness. The new isolate grows best in culture with careful control of pH. The two isolates are nearly identical as determined by light and electron microscopy and have significant antigenic identity in fluorescent-antibody and immunoblot assays using polyclonal antisera and the E. chaffeensis-specific monoclonal antibody 1A9. Isolate 91HE17 had 99.9% nucleotide sequence identity with the Arkansas strain in the 16S rRNA gene. Parts of the Escherichia coli GroE operon homologs had identical restriction enzyme digestion patterns, and a 425-bp region of the GroEL gene had at least 99.8% sequence identity between the E. chaffeensis Arkansas and 91HE17 strains. Isolate 91HE17 lacked an epitope identified in E. chaffeensis Arkansas by the monoclonal antibody 6A1. This new E. chaffeensis isolate is very similar to the Arkansas strain and provides the opportunity to substantiate the existence of diversity among ehrlichiae which infect humans. Specific factors which differ among strains may then be compared to assess their potential contributions toward cellular pathogenicity and ultimately toward the development of disease in humans.

Ultrasonic detection of persistent small unilateral hematocolpos in two girls

Two girls with unilateral hematocolpos are reported. In both cases, a small amount of blood which had accumulated in the partially obstructed hemivagina was detected by real-time high resolution ultrasonography, and was confirmed by magnetic resonance imaging. Both patients were asymptomatic, and were regularly followed up at an outpatient clinic. To date, the hematocolpos persists but continues to be small.

Cultivation of Ehrlichia chaffeensis in mouse embryo, Vero, BGM, and L929 cells and study of Ehrlichia-induced cytopathic effect and plaque formation

We successfully propagated Ehrlichia chaffeensis in mouse embryo, Vero, BGM, and L929 cells inoculated with host cell-free ehrlichiae, indicating that E. chaffeensis is capable of entry, survival, and growth in a relatively wide range of cell types derived from different species. We demonstrated rapid adaptation of E. chaffeensis in these cell lines, so that typical morulae could be detected as early as 5 days after inoculation. E. chaffeensis-induced cytopathic effect with different morphological characteristics in mouse embryo, Vero, and L929 cells. The earliest cytopathic effect appeared in untreated and irradiated mouse embryo cells at 4 days postinoculation. As the infected foci gradually expanded, the center of the foci showed necrotic cells with pyknotic nuclei and degraded morulae. E. chaffeensis caused cell lysis in untreated and irradiated L929 cells, with formation of distinct, round macroscopic plaques at 18 days postinoculation. In untreated and irradiated Vero cells, E. chaffeensis produced infected foci composed of loosely interwoven necrotic cells, spaces of detached cells, cells filled with morulae, and uninfected cells, resulting in characteristic reticular foci. Irradiated cells generally contained many large morulae and presented larger cytopathic foci. DH82 and BGM cells did not develop obvious cytopathic foci under the conditions employed. The findings reported herein offer the opportunity to study the pathogenic mechanism of cell injury by E. chaffeensis, the basis for quantification of infectious E. chaffeensis, improved approaches for recovery of ehrlichiae from human patients and tick hosts, and additional methods for cultivation of E. chaffeensis for molecular analysis.

Serum thyrotropin-binding inhibiting immunoglobulin and thyroperoxidase antibody in Graves' hyperthyroidism after 131I therapy

Seventeen patients who received radioiodine (131I) therapy for Graves' hyperthyroidism had serial blood samples taken before therapy and after therapy for a period of at least 1 year. At 1 year post-therapy, six patients were hypothyroid. Seven patients were euthyroid, and four patients were hyperthyroid. Prior to isotope administration, 14 patients had detectable serum thyrotropin-binding inhibiting immunoglobulin (TBII) and 16 patients had detectable serum thyroperoxidase antibody (TPOAb). Three to 6 months after therapy, 11 of 14 TBII-positive patients demonstrated a marked increase (> 10%) in serum TBII activity. Four patients out of 11 developed hypothyroidism and six of the 11 developed euthyroidism. A decrease in TBII was observed in three patients who developed hyperthyroidism. In the three patients with undetectable TBII prior to therapy, two had high titers of TPOAb. Seven patients demonstrated a marked increase in TPOAb 3 to 6 months after therapy. Of these, four developed hypothyroidism and three developed euthyroidism, whereas three of the four patients who had a marked decrease in TPOAb developed hyperthyroidism. This study demonstrated that an increase in serum TBII and TPOAb activity 3 to 6 months after 131I therapy, may be useful in predicting which patients may develop euthyroidism or hypothyroidism after 1 year of 131I therapy.

Function of streptokinase fragments in plasminogen activation

Several peptide fragments of streptokinase (SK) were prepared by incubating SK with immobilized human plasmin (hPlm) and purified by h.p.l.c. with a reverse-phase phenyl column. The N-terminal sequences, amino acid compositions and molecular masses of these peptide fragments were determined. The SK peptide fragment of 36 kDa consisting of Ser60-Lys387 (SK-p), was the only peptide fragment that could be tightly bound to immobilized hPlm. Another three large SK peptide fragments, SK-m, SK-n and SK-o, with molecular masses of 7 kDa, 18 kDa and 30 kDa, and consisting of Ile1-Lys59, Glu148-Lys333, Ser60-Lys333 respectively, were also obtained from the supernatant of the reaction mixture. The purified SK-p had high affinity with hPlm and could activate human plasminogen (hPlg) with a kPlg one-sixth that of the native SK. SK-o had low affinity with hPlm and could also activate hPlg, although the catalytic constant was less than 1% of the native SK. SK-n, as well as SK-m, which is the N-terminal 59 amino acid peptide of the native SK, had no activator activity. However, SK-m could enhance the activator activity of both SK-o and SK-p and increase their second-order rate constants by two- and six-fold respectively. It was concluded from these studies that (1) SK-o, the Ser60-Lys333 peptide of SK, was essential for minimal SK activator activity, (2) the C-terminal peptide of SK-p, Ala334-Lys387, was essential for high affinity with hPlm, and (3) the N-terminal 59-amino-acid peptide was important in maintaining the proper conformation of SK to have its full activator activity.

Two-dimensional 1H NMR studies of immobile Holliday junctions: nonlabile proton assignments and identification of crossover isomers

The nonlabile protons of two 32-base-pair models of the Holliday junction intermediate in genetic recombination have been studied by two-dimensional 1H nuclear magnetic resonance (NMR) spectroscopy. The sequence of these models is designed to fully inhibit branch migration of the junction and to probe the possible sequence dependence of these four-arm DNA structures. Overlap of resonances in homonuclear two-dimensional nuclear Overhauser enhancement (NOE) spectra necessitates the use of a multipathway approach for obtaining sequence-specific assignments, wherein all possible NOE connectivities are analyzed in parallel. Using this strategy, 1H resonance assignments were obtained for virtually all nonlabile base protons and C1', C2', and C3' sugar protons. Several unambiguous cross-arm NOE connectivities were identified, directly establishing the stacking arrangements of each contiguous (two-arm) helical domain. The distribution of the two possible stacking isomers is distinctly different for the two junctions studied, thereby indicating that the relative stability of the isomers is dependent on the sequence at the junction.

Serum and ascitic concentration of C3, C4 and protein in cirrhotic patients with spontaneous bacterial peritonitis

BACKGROUND

Lower concentration of ascitic or serum complement (C3, C4) or protein has been reported to participate in the development of spontaneous bacterial peritonitis (SBP). In Taiwan, the etiology of hepatic cirrhosis is mainly post-hepatic and SBP is the common complication. This study aims to determine the role of protein and complements in the pathogenesis of SBP.

METHODS

119 cirrhotic patients were divided into two groups, 30 SBP and 89 non-SBP. The concentrations of ascitic and serum complement and protein were measured for comparison.

RESULTS

The ascitic and serum C3, C4 and protein levels were significantly lower (P < 0.05) in patients with SBP than in non-SBP patients. No significant differences were noted in the ascites/serum ratio of C3, C4 and protein in patient with or without SBP.

CONCLUSIONS

Low levels of ascitic and serum protein and complements, C3 and C4, may be prone to develop SBP in our patients mostly with post-hepatitic cirrhosis.

Human granulocytic ehrlichiosis in the upper Midwest United States. A new species emerging?

OBJECTIVE

To characterize the clinical presentation and course, laboratory findings, and treatment outcome of 12 patients with human granulocytic ehrlichiosis.

SETTING

The 12 patients were male, ranged in age from 29 to 91 years, and contracted their illness in Wisconsin or Minnesota.

METHODS

Cases were recognized by the presence of intracytoplasmic inclusions (morulae) in peripheral neutrophils of patients presenting with temperature of 38.5 degrees C or higher, chills, severe headache, and myalgias. All patients had a complete blood cell count and blood chemistry profile. Blood smears were examined by light microscopy. All available paired serum samples were analyzed for presence of indirect fluorescent antibodies against Ehrlichia chaffeensis, Ehrlichia phagocytophila, and Ehrlichia equi. Blood samples from 12 patients were subjected to polymerase chain reaction analysis using primers specific for the E phagocytophila/E equi group, primers that include the agent identified in our patients, as well as E chaffeensis.

RESULTS

Varying combinations of leukopenia, anemia, and thrombocytopenia were found in all but one patient. All 12 patients demonstrated morulae in the cytoplasm of neutrophils, but not in mononuclear white blood cells. Serum assays failed to detect antibodies against E chaffeensis, but eight of 10 patients and seven of 10 patients tested had antibody titers of 1:80 or more for E phagocytophila and E equi, respectively. Polymerase chain reaction products obtained with primers for E phagocytophila, E equi, and the granulocytotropic Ehrlichia revealed that seven patients were infected with the same agent. The results of serological assays or polymerase chain reaction strongly suggest that all 12 patients were infected by E phagocytophila, E equi, or a closely related Ehrlichia species. Two of the 12 patients died. The other 10 patients improved rapidly with oral doxycycline treatment.

CONCLUSIONS

We believe that all 12 patients have been infected with a granulocytic Ehrlichia species, reflecting a recently described new disease entity. The infective organism appears to be closely related to E phagocytophila and E equi. The geographic domain of human granulocytic ehrlichiosis is currently unknown. This novel granulocytic Ehrlichia species is capable of causing fatal infections in humans. Early detection and treatment with tetracycline drugs appear to offer the best chance for complete recovery.

Effect of intradialytic parenteral nutrition on mortality rates in end-stage renal disease care

Several studies have now demonstrated that low serum albumin and/or low protein catabolic rates correlate with increased risk of death in the chronic hemodialysis patient. A study involving 81 patients receiving thrice-weekly hemodialysis treatments and who had either a low serum albumin and/or protein catabolic rate was conducted to compare the effect of intradialytic parenteral nutrition (IDPN) on mortality rates. Fifty patients received IDPN and 31 patients did not. Thirty-eight of the patients were black (47%), 34 were white (42%), and 9 were Hispanic (11%). The study included 33 diabetic patients (41%), 20 of whom received IDPN. Nondiabetic patients received an average of 725 kcal/hemodialysis treatment and diabetic patients received an average of 670 kcal/hemodialysis treatment. The average length of treatment was 9 months. The results of the study revealed a better survival rate (64% v 52%) for patients treated with IDPN. Using Cox analysis, the IDPN-treated group had a significantly better survival rate (P < 0.01). Serum albumin increased by 12% in the survivors. There was no difference in survival when considered separately for diabetic and nondiabetic patients who received IDPN (mortality rate for diabetics: 50% for treated patients and 54% for untreated patients; mortality rate for nondiabetics: 26% for treated patients and 44% for untreated patients). However, the nondiabetic treated patients had the lowest mortality rates. In conclusion, correction of hypoalbuminemia by IDPN significantly reduced mortality rates overall.

Early detection of unilateral occlusion of duplicated müllerian ducts: the use of serial pelvic sonography for girls with renal agenesis

For early detection of unilateral occlusion of duplicated müllerian ducts, serial pelvic sonography was performed in 215 girls with known renal agenesis, especially following menarche, during the last 6 years. To date, 16 girls with unilateral occlusion of duplicated müllerian ducts were detected. We stress the value of this modality, which can lead to a prompt diagnosis, and allow for early and appropriate surgical intervention.

Identification of a granulocytotropic Ehrlichia species as the etiologic agent of human disease

Six patients from northern Minnesota and Wisconsin with a febrile illness accompanied by granulocytic cytoplasmic morulae suggestive of ehrlichial infection were identified. Two patients died, and splenic granulocytes of one patient contained cytoplasmic vacuoles with organisms ultrastructurally characteristic of ehrlichiae. From one patient, a 1.5-kb DNA product was amplified by PCR with universal eubacterial primers of 16S rDNA. Analysis of the nucleotide sequence of the amplified product revealed 99.9 and 99.8% similarities with E. phagocytophila and E. equi, respectively, neither of which has previously been known to infect humans. From the variable regions of the determined sequence, a forward primer specific for three organisms (human granulocytic ehrlichia, E. phagocytophila, and E. equi) and a reverse primer for these ehrlichiae and E. platys were designed. By nested PCR with amplification by the universal primers and then reamplification with the specific primers described above, the expected 919-bp product was generated from the blood of the index patient and three additional patients. Blood from these four patients and two more patients with granulocytic morulae contained DNA which was amplified by nested PCR involving a combination of a universal primer and the human granulocytic ehrlichia-E. phagocytophila-E. equi-E. platys group-specific primer. This apparently vector-borne human granulocytic ehrlichia has only 92.5% 16S rDNA homology with E. chaffeensis. Nested PCR with group-specific primers did not amplify E. chaffeensis DNA, and E. chaffeensis-specific primers did not amplify DNAs of the human granulocytic ehrlichia. Thus, six patients were shown to be infected by an Ehrlichia species never previously reported to infect humans.