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.

Identification of the antigenic constituents of Ehrlichia chaffeensis

Ehrlichia chaffeensis, the novel etiologic agent of human ehrlichiosis in the United States, was first isolated in 1990 and reported in 1991. To analyze the antigenic components of E. chaffeensis, we cultivated these obligate intracellular bacteria in DH82 cells, purified the ehrlichiae by renografin density gradient centrifugation, and examined the antigens by Western immunoblotting. Rabbit and human antisera to E. chaffeensis revealed more than 20 bands ranging from 20 to 200 kD. The distinct 22-kD protein was heat labile. The rest of the major immunoreactive components were heat stable. The immunoblots of E. chaffeensis were highly similar when probed with antisera to E. chaffeensis, E. canis, and E. ewingii, indicating the close antigenic relationships among the three species. The 22-kD protein cross-reacted only with anti-E. canis serum. The antibody against E. sennetsu reacted strongly with the 66-, 64-, 55-, and 44-kD antigens of E. chaffeensis. The E. risticii antisera reacted strongly with the 55- and 44-kD bands but only faintly with the 66-kD band. The major immunoreactive antigens of E. chaffeensis (66, 55, and 44 kD) showed cross-reactions with all the different antisera tested. The results indicated that E. chaffeensis is antigenically most closely related to E. canis, is less closely related to E. ewingii, and is only distantly related to E. sennetsu and E. risticii.

Computed tomography of an exophytic gastric hemangioma with torsion and intratumoral hemorrhage

A case of exophytic gastric hemangioma with intratumoral bleeding due to torsion of the tumor pedicle is reported. A radiograph showed a mass without phleboliths. Computed tomography (CT) demonstrated a 14-cm mass with high densities due to hemorrhage, which was contiguous to the stomach and extended to the pelvis. The tumor showed no remarkable enhancement on post-enhanced CT due to torsion of the tumor pedicle.

Two-dimensional 1H NMR studies of 32-base-pair synthetic immobile Holliday junctions: complete assignments of the labile protons and identification of the base-pairing scheme

The labile protons of two 32-base-pair, four-arm models of immobile Holliday junctions have been studied by two-dimensional 1H nuclear magnetic resonance (NMR) spectroscopy. Overlap of resonances in the imino-imino region of two-dimensional nuclear Overhauser enhancement (NOE) spectra necessitates the use of a multi-pathway approach for obtaining sequence-specific assignments wherein all possible NOE connectivities to the labile protons are utilized, including those from the 2H of adenine, 5CH3 of thymine, and 5H of cytosine. Resonance assignments are obtained for all slowly exchanging imino and cytosine amino protons. Base-pairing up to and including the junction point is found in all four arms of both Holliday junctions. Several cross-arm NOE connectivities are identified and can be used to infer the geometry of the helical stacking domains. The two Holliday junctions studied, which differ only by the exchange of two base pairs at the branch point, appear to have opposite arm stacking geometries. These assignments form an important part of the critical background for detailed NMR analysis of Holliday junction structure and dynamics.

Synthesis of new amino acid and peptide derivatives of estradiol and their binding affinities for the estrogen receptor

A series of amino acid and peptide derivatives of estradiol have been synthesized by coupling 17 beta-aminoestra-1,3,5(10)-trien-3-ol, 17-hydrazonoestra-1,3,5(10)-trien-3-ol with amino acids or peptides, using tetrahydrothiazole-2-thione, N-hydroxy-1,4-epoxycyclohex-5-ene-2,3-dicarbonylimide, benzotriazolyloxy-tris(dimethylamino)phosphonium hexafluorophosphate, and p-nitrophenol as reagents. N-protected peptidyl steroids were deprotected by traditional methods. The relative binding affinities of the deprotected derivatives to the estrogen receptor were determined by competitive radioligand binding assay.

Amelioration of antioxidant enzyme suppression and proteinuria in cyclosporin-treated puromycin nephrosis

The effect of cyclosporin (CS) on intrinsic glomerular level of antioxidants in puromycin aminonucleoside (PAN) nephrosis was examined. A single intravenous dose of PAN (50 mg/kg body weight) given to Sprague-Dawley rats resulted in marked proteinuria. Ten days after PAN injection, the rats were treated with daily intraperitoneal injection of CS (10 mg/kg body weight/day) for 10 days. PAN-treated rats without CS treatment (PAN rats) had significantly lower activities of glomerular superoxide dismutase (SOD) and catalase (CAT) than normal rats (p < 0.05, respectively). When compared with PAN rats, CS-treated PAN rats had significantly less proteinuria and higher activities of glomerular SOD and CAT (p < 0.01 and p < 0.05, respectively). Significant elevation of glomerular malondialdehyde (MDA) level characteristic of PAN rats was absent in CS-treated PAN rats. Moreover, segmental sclerosis with capsular adhesion, hyalinosis, epithelial cell foot process fusion and microvillous transformation seen in PAN rats were apparently attenuated in CS-treated PAN rats. When compared with normal rats, rats receiving CS only had a significantly higher CAT activity and MDA level (p < 0.01 and p < 0.05, respectively). Assessment of glomerular reduced glutathione revealed no significant differences among PAN rats, CS-treated PAN rats, normal rats, and rats receiving only CS. These data indicate that glomerular antioxidant enzyme activities are modulated by CS.

Distance distribution in a dye-linked oligonucleotide determined by time-resolved fluorescence energy transfer

Fluorescence energy transfer is potentially a useful technique for obtaining structural and dynamic information on duplex and branched DNA molecules suitably labeled with donor and acceptor dyes. We have assessed the accuracy and limitations of FET measurements in nucleic acids with respect to the localization of the dyes and the flexibility of the dye-DNA linkages. A nine base-pair duplex oligonucleotide was synthesized with donor and acceptor dyes linked at the opposing 5' termini by alkyl chains. A careful analysis of the fluorescence decay of the donor revealed that the donor-acceptor distance in this molecule was not well defined, but was described by a rather broad distribution. The mean donor-acceptor distance and the distribution of distances have been recovered from the donor decay. Orientational effects on energy transfer have been included in the analysis. The implications of these findings for FET measurements in nucleic acids are considered.

The use of capillary electrophoresis in a micropreparative mode: methods and applications

The ability to collect sufficient quantities of analytes from capillary electrophoresis for subsequent analyses is demonstrated. Fractions collected have been analyzed using the following techniques: capillary electrophoresis, mass spectrometry, and protein sequencing. Fractions can be collected directly into small volumes of buffer or directly onto membrane surfaces. Relevant parameters such as capillary diameter, mass loading, and separation parameters are addressed.

Isoelectric focusing by free solution capillary electrophoresis

A reproducible, quantitative isoelectric focusing method using capillary electrophoresis that exhibits high resolution and linearity over a wide pH gradient was developed. RNase T1 and RNase ba are two proteins that have isoelectric points (pI's) at the two extremes of a pH 3-10 gradient. Site-directed mutants of the former were separated from the wild-type form and pI's determined in the same experiment. The pI's of RNase T1 wild-type, its three mutants, and RNase ba were determined for the first time as 2.9, 3.1, 3.1, 3.3, and 9.0, respectively. The paper describes the protocol for isoelectric focusing by capillary electrophoresis, as well as presenting data describing the linearity, resolution, limits of mass loading, and reproducibility of the method.

Effect of traditional Chinese herbal medicines on the pharmacokinetics of western drugs in Sprague-Dawley rats of different ages (II): Aminophylline-huan shao tan and aminophylline-pu chung yi chi tang

The effect of Chinese herbal medicines (Huan Shao Tan and Pu Chung Yi Chi Tang) and western drugs (sodium phenobarbital and cimetidine) on the serum concentration and pharmacokinetic parameters of theophylline and cytochrome P-450 of Sprague-Dawley (SD) rats of three different ages were examined. The older rats without pretreatment with Chinese herbal medicines and western drugs exhibited higher serum theophylline concentration and lower pharmacokinetic parameters of theophylline than middle-aged and younger rats (P < 0.05), but there was no difference in cytochrome P-450 activity among the three different ages of rats. All rats when pretreated with sodium phenobarbital showed lower serum theophylline concentration and higher pharmacokinetics parameters of theophylline. Also, the activity of cytochrome P-450 was higher (P < 0.05). When cimetidine was pre-administered in SD rats of three age groups, all rats exhibited lower serum theophylline concentration and higher pharmacokinetics parameters (P < 0.05), but the activity of cytochrome P-450 remained unchanged (P > 0.05). The results were opposite to other studies, probably because the dose and dosing intervals were different. No single effect occurred on the younger and middle-aged rats after pretreatment with Huan Shao Tan and Pu Chung Yi Chi Tang: their serum theophylline concentration, pharmacokinetics parameters and cytochrome P-450 activity were the same as the control group. However, the older rats after pretreatment with Huan Shao Tan or Pu Chung Yi Chi Tang showed lower serum theophylline concentration and higher pharmacokinetics parameters than the younger and middle-aged rats pretreated with similar Chinese herbal medicines. This indicates that Huan Shao Tan and Pu Chung Yi Chi Tang may perhaps improve the elimination of theophylline in older rats. This might be attributed to the increase in hepatic blood flow or in liver volume, since the activity of cytochrome P-450 was not affected by the administration of Chinese herbal medicines.

Two-dimensional NMR studies of d(GGTTAATGCGGT).d(ACCGCATTAACC) complexed with the minor groove binding drug SN-6999

The dodecadeoxynucleotide duplex d(GGTTAATGCGGT).d(ACCGCATTAACC) and its 1:1 complex with the minor groove binding drug SN-6999 have been prepared and studied by two-dimensional 1H nuclear magnetic resonance spectroscopy. Complete sequence-specific assignments have been obtained for the free duplex by standard methods. The line widths of the resonances in the complex are greater than those observed for the free duplex, which complicates the assignment process. Extensive use of two-quantum spectroscopy was required to determine the scalar correlations for identifying all of the base proton and most of the 1'H-2'H-2''H spin subsystems for the complex. This permitted unambiguous sequence-specific resonance assignments for the complex, which provides the necessary background for a detailed comparison of the structure of the duplex, with and without bound drug. A series of intermolecular NOEs between drug and DNA were identified, providing sufficient structural constraints to position the drug in the minor groove of the duplex. However, the combination of NOEs observed can only be rationalized by a model wherein the drug binds in the minor groove of the DNA in both orientations relative to the long helix axis and exchanges rapidly between the two orientations. The drug binds primarily in the segment of five consecutive dA-dT base pairs d(T3T4A5A6T7).d(A18T19T20A21A22), but surprisingly strong interactions are found to extend one residue in the 3' direction along each strand to G8 and C23. The observation of intermolecular contacts to residues neighboring the AT-rich region demonstrates that the stabilization of the bis(quaternary ammonium) heterocycle family of AT-specific, minor groove binding drugs is not based exclusively on interactions with dA-dT base pairs.

Locating essential Escherichia coli genes by using mini-Tn10 transposons: the pdxJ operon

The mini-Tn10 transposon (delta 16 delta 17Tn10) confers tetracycline resistance. When inserted between a gene and its promoter, it blocks transcription and prevents expression of that gene. Tetracycline in the medium induces divergent transcription of the tetA and tetR genes within the transposon, and this transcription extends beyond the transposon in both directions into the bacterial genes. If the mini-Tn10 inserts between an essential bacterial gene and its promoter, the insertion mutation can cause conditional growth which is dependent on the presence of tetracycline. Two essential genes in adjacent operons of Escherichia coli have been detected by screening for tetracycline dependence among tetracycline-resistant insertion mutants. These essential genes are the era gene in the rnc operon and the dpj gene in the adjacent pdxJ operon. The pdxJ operon has not been described previously. It consists of two genes, pdxJ and dpj. Whereas the dpj gene is essential for E. coli growth in all media tested, pdxJ is not essential. The pdxJ gene encodes a protein required in the biosynthesis of pyridoxine (vitamin B6).

Conformational studies of the duplex d-(CCAAAAATTTCC).d-(GGAAATTTTTGG) containing a (dA)5 tract using two-dimensional 1H-n.m.r. spectroscopy

A variety of two-dimensional nuclear magnetic resonance (n.m.r.) techniques were utilized for structural studies of the dodecadeoxy-nucleotide duplex d-(CCAAAAATTTCC).d-(GGAAATTTTTGG). Overall, the duplex was found to adopt a conformation of the B-DNA type. Direct measurement of 1H-1H coupling constants of the deoxyribose rings and comparison of nuclear Overhauser effects (NOEs) involving characteristic intra- and inter-nucleotide proton-proton connectivities indicate that the sugar rings are all in predominantly C2'-endo/S-type conformation. The appearance of NOEs between adenine 2H and sugar l'H resonances indicates a narrowing of the minor groove at the 3' end of the (dA)n tracts. Several lines of evidence indicate that a conformational change in the DNA duplex is introduced by the (dA)5 tract, in support of the junction model for curved DNA. The results are compared with previous structural studies of the evidence for curvature in duplex DNA containing (dA)n tracts.

Reduced glutathione, superoxide dismutase contents and malondialdehyde formation in platelets from uremic patients: relation to plasma and platelet zinc

Platelet-reduced glutathione (GSH), superoxide dismutase (SOD) and zinc content as well as malondialdehyde (MDA) formation were studied in 55 healthy volunteers as controls and 49 patients with chronic renal failure. Uremic patients had a significantly lower GSH and SOD content as well as an abnormal MDA formation in their platelets. Their plasma zinc level was sharply below the normal value, but their platelet zinc content was similar to that of normal controls. We also found that the plasma zinc and platelet zinc level was positively correlated to the platelet GSH content in normal controls and uremic patients. Therefore, the results suggest that in uremic patients the decrease in platelet antioxidant agents (GSH and SOD) may be partially related to their low plasma zinc level.

Factors affecting survival of hemodialysis patients utilizing urea kinetic modeling. A critical appraisal of shortening dialysis times

The objective of this study was to analyze risk factors affecting mortality rates (MR) in hemodialysis patients undergoing shortened dialysis time who were regularly kinetically modeled. Over a 14-month period, 180 in-center hemodialysis patients, 54% male, 46% female, 57% Black, 39% Caucasian, and 4% Hispanic, treated with rapid high efficiency dialysis (RHED = 2-3 h, 3 times/week) and conventional dialysis (3-4 h, 3 times/week) were studied. Median patient age was 56.7 years (16-84 years) and dialysis care ranged from 6 months to 18 years (mean +/- SD = 4.0 +/- 4.2 years). The patients underwent monthly urea kinetic modeling. The dialysis prescription was based upon normalizing Kt/V between 0.8 and 1.2 and the protein catabolic rate (PCRn) between 0.9 and 1.1. Thirty-three percent of the patients received recombinant human erythropoietin (r-HuEPO). The effects of various covariates, including primary diagnosis, post/predialysis BUN ratios, creatinine, albumin, calcium, phosphate, cholesterol, hemoglobin, r-HuEPO, Kt/V, and PCRn were analyzed using analysis of variance, chi 2 and linear discriminant function (DF) statistical methods. Several significant factors emerged as influencing outcome. The DF analysis produced a highly statistically significant (p < 0.0001) model to predict mortality based upon certain laboratory and dialysis parameters. Further, the linear DF correctly predicted mortality rate in 86% of cases. The results of the analysis revealed an overall mortality rate of 15.6%; hospitalization rates (HR) were 1.4 +/- 1.8 times/year. Length of dialysis time, i.e., dialysis times between 2 and 4 h, when adjusted for Kt/V has no correlation with MR or HR. Variables associated with survival were higher post/predialysis BUN ratios, normal Kt/V (0.8-1.2), normal albumin levels (> 3.5 g/dl), higher postdialysis BUN, creatinine, and cholesterol levels, and use of r-HuEPO. The use of r-HuEPO when analyzed by DF significantly improved MR, 8.3% as opposed to 19.2%. It is concluded that urea kinetic modeling permits shortening dialysis times without affecting mortality or hospitalization rates, and that low postdialysis BUN, post/predialysis BUN ratios, creatinine, and albumin values are correlated with a lower chance of survival.

[Photic maculopathy by low energy laser beam. A case report]

The authors report a case of photic maculopathy that developed in a 30-year-old laboratory worker after repeated, consecutive exposure to low energy He-Ne laser. Pigmented foveal change and a small central scotoma in the right eye with window defect on fluorescein angiography characterized this maculopathy. Photochemical damage is considered to be the cause of the maculopathy.

Studies on the photochemical and photocytotoxic properties of the new PDT photosensitizer aluminum sulfonated phthalocyanine

The properties of photosensitization of sulfonated aluminum phthalocyanine (ALSPC), a new photosensitizer of potential use in cancer photodynamic therapy (PDT) was studied on both the molecular and cellular levels. The mechanism of ALSPC photosensitization on the molecular level was investigated by testing its efficiency of singlet oxygen (1O2) production, using the method of tryptophan degradation and that of ESR spectroscopy and observing the enhancing effect of D2O and the quenching effect of NaN3. Results of all these experiments confirmed the important role of the Type II or 1O2 mechanism in ALSPC photosensitization. In our in-vitro experiments, ALSPC's incorporation into cells and its photocytotoxic effect were investigated on a human liver cancer cell line. The cell incorporation was illustrated by the laser-excited fluorescence spectra emitted both from cell homogenate and cell monolayers incubated with ALSPC aqueous solution. The position of fluorescence peak observed, implied that ALSPC exists in the cells mainly as monomers. The efficiency of cell killing of ALSPC photosensitization was estimated by counting surviving cells with the method of trypan blue staining and by the method of radioisotope labelling. Experiments using the latter method also showed DNA damage caused by ALSPC photosensitization.

[Acetylcholine receptor antibody titer, sensitivity to curare electromyogram and disease severity in myasthenia gravis]

All of 39 rabbits immunized with acetylcholine receptors invariably formed anti-AChR Abs and some of them developed muscular weakness or flaccid paralysis. Pharmacological, physiological and ultrastructural studies indicated that the pathology of experimental autoimmune myasthenia gravis in rabbits resembled that of human myasthenia gravis. The titer of anti-AChR Abs correlated poorly with disease severity and did not simply predicted the muscular weakness. The results ruled out the possibility that antigenic modulation of AChR was sufficient to account for the induction of myasthenia gravis. There was a close relationship between the sensitivity to curare and disease severity, but only part of immunized animals appeared electromyogram change. This led us to conclude that serum anti-AChR concentration would not be the single pathological factor in myasthenia gravis and disease severity may correlate with amount of normal AChR.

Effect of traditional Chinese herbal medicines on the pharmacokinetics of western drugs in SD rats of different ages. I. Aminophylline-Tin chuan Tang and aminophylline-Hsiao Ching Long Tang

The effect of the traditional Chinese herbal medicines (Tin Chuan Tang and Hsiao Ching Long Tang) on the serum concentrations and pharmacokinetics of aminophylline was examined in three different ages of SD rats. Each traditional Chinese herbal medicine was orally preadministered to SD rats for one week and then aminophylline was administered intravenously. The serum concentrations and pharmacokinetic parameters of theophylline were estimated by a two-compartment open model. The liver isolated after the last blood sampling was homogenized and the activity of hepatic cytochrome p-450 was determined. Significant difference was found in some pharmacokinetic parameters of theophylline such as K10, t 1/2, Cl and Vd for three different ages of SD rats without pretreatment with Chinese herbal drugs (p less than 0.05). However, pretreatment with Tin Chuan Tang or Hsiao Ching Long Tang did not affect the pharmacokinetic parameters of theophylline in three different ages of SD rats (p greater than 0.05). We also found that there was no correlation between age and activity of cytochrome p-450 of SD rats (p greater than 0.05). The decline in some pharmacokinetic parameters of theophylline in the elderly rats perhaps might be attributed to the decrease in hepatic blood flow and liver volume. It is concluded that there was no drug interaction between theophylline and Tin Chuan Tang or Hsiao Ching Long Tang in the different ages of SD rats.

Two-dimensional 1H NMR studies of synthetic immobile Holliday junctions

Two 32 base pair, four-arm immobile Holliday junctions have been prepared and studied by two-dimensional 1H nuclear magnetic resonance (NMR) spectroscopy. Two-quantum spectroscopy provides scalar (through bond) correlations for the 1'H, 2'H, and 2''H resonances of the deoxyribose sugar rings and the nonlabile cytosine and thymine base protons. Assignments in the deoxyribose sugars are extended to the 3'H resonances principally from relayed connectivities in total correlation spectra. Severe overlap of resonances in the standard regions of two-dimensional nuclear Overhauser enhancement (NOE) spectra necessitated the use of a unique approach for obtaining sequence-specific assignments of duplex DNA, wherein all possible NOE connectivities in the spectra are analyzed. These studies of 64-residue structures represent a substantial step forward with respect to the size of oligonucleotide for which virtually complete assignments are obtained. The assignments form the critical background for the detailed analysis of Holliday junction structure and dynamics that is required to address key issues in understanding the role of Holliday junctions in genetic recombination and repair.

Renal excretion of citrate in patients with chronic renal failure or nephrolithiasis

Using a specific citrate lyase method, renal excretion of citrate was studied in 32 normal Chinese males, 30 nondialysed uremic male patients and 35 male subjects who had a history of nephrolithiasis. Patients with uremia or nephrolithiasis were found to have a lower urinary citrate excretion. Tubular reabsorption of citrate was markedly decreased in uremic patients, but in stone patients, the increased renal tubular reabsorption of citrate was only found in patients with hypocitraturia, whose renal citrate excretion was below 650 mumol/day and whose urinary magnesium was also low. Hypocitraturia was found in 45% (16/35) of the patients with renal stones whether their filtered load of citrate was normal or subnormal. Urinary citrate excretion was correlated with renal creatinine clearance in both normal subjects and in patients with renal stones or chronic renal failure. However, urinary phosphate correlating with urinary citrate was only found in normal subjects and in patients with kidney stones. In normal subjects, we found a positive correlation between urinary citrate and phosphate, but in stone patients, we found a negative correlation. Hypercalciuria and hyperoxalaturia were noted in some stone formers, who had, moreover, a lower urinary citrate and ascorbate excretion level. Mean urinary ascorbate excretion in patients with renal stones was markedly below that in normal subjects. Thus, we suggest that low urinary citrate excretion may be prevalent in patients with renal stones or chronic renal failure, and that hypocitraturia can be found in some stone formers, whose tubular reabsorption of citrate may be increased.

[Clinical correlation of anti-receptor antibody titer, sensitivity to curare and electromyographic changes in experimental autoimmune myasthenia gravis]

Experimental autoimmune myasthenia gravis (EAMG) was studied in 39 rabbits which were repeatedly immunized with purified membrane-bound Torpedo (Nacine timilei) acetylcholine receptor (N-AchR). These rabbits invariably formed anti-AChR antibodies and some of them developed muscular weakness or flaccid paralysis. Pharmacological, physiological and ultrastructural studies showed that the pathological features of EAMG in rabbits closely resembled those of human myasthenia gravis. Antibody titer to AChR of the rabbit sera was determined with ELISA. In some of the rabbits, a rise in antibody Level occurred without appearance of weakness, while it is still likely that AChR antibody could be necessary for the induction of neuromuscular blockage. The sensitivity to curare was found to correlates closely with the severity of the disease. Typical electromyographic changes were found only in some of the EAMG rabbits with these studies. It was considered that anti-AChR concentration would not be the single pathological factor in EAMG.