Effect of clarithromycin and azithromycin on production of cytokines by human monocytes

We examined the in vitro effect of clarithromycin and azithromycin on cytokine production by LPS and Pansorbin stimulated human monocytes. At concentrations that are physiologically achievable, both antibiotics affected in vitro production of IL-1alpha, IL-1beta, IL-6, IL-10, GM-CSF and TNF-alpha to varying degrees. Of those individuals in whom a significant increase or decrease in cytokine production was noted, clarithromycin treatment resulted in a significant suppression of production of each cytokine in 71% and a significant increase in 29% of the individuals. Similar results were noted with azithromycin. The results with IL-6 and TNF-alpha in the clarithromycin studies were most striking. A significant decrease was noted in 60% of individuals for IL-6 and 86% for TNF-alpha. For azithromycin, the most interesting results were for IL-1alpha (decrease in 100% of individuals) and for TNF-alpha (decrease in 100% of individuals). These results show that both clarithromycin and azithromycin alter cytokine production in human monocytes and thus possess immunomodulatory activity.

Identification and sequencing of a cDNA encoding 6-phosphogluconate dehydrogenase from a fungus, Cunninghamella elegans and expression of the gene in Escherichia coli

The fungus, Cunninghamella elegans has been widely used in bioremediation and microbial models of mammalian studies in many laboratories. Using the polymerase chain reaction to randomly amplify the insert directly from the single non-blue plaques of a C. elegans cDNA library, then partly sequencing and comparing with GenBank sequences, we have identified a clone which contains C. elegans 6-phosphogluconate dehydrogenase gene. The polymerase chain reaction product was cloned into a plasmid, pGEM-T Easy vector for full insert DNA sequencing. The 6-phosphogluconate dehydrogenase gene (1458 bases) and the deduced protein sequence were determined from the insert DNA sequence. The gene was found by open reading frame analysis and confirmed by the alignment of the deduced protein sequence with other published 6-phosphogluconate dehydrogenase sequences. Several highly conserved regions were found for the 6-phosphogluconate dehydrogenase sequences. The 6-phosphogluconate dehydrogenase gene was subcloned and over-expressed in a plasmid-E. coli system (pQE30). The cell lysate of this clone has a very high 6-phosphogluconate dehydrogenase enzyme activity. Most of the recombinant protein in this system was formed as insoluble inclusion bodies, but soluble in high concentration of urea-buffer. Ni-NTA resin was used to purify the recombinant protein which showed 6-phosphogluconate dehydrogenase enzyme activity. The recombinant protein has a predicted molecular size correlating with that revealed by sodium dodecylsulfate-polyacrylamide gel electrophoresis analysis. The C. elegans 6-phosphogluconate dehydrogenase was in a cluster with yeast' 6-phosphogluconate dehydrogenase in the phylogenetic tree. Bacterial 6-phosphogluconate dehydrogenase and higher organisms' 6-phosphogluconate dehydrogenase were found in different clusters.

The wandering coronary stent. Case report

Complications associated with coronary stent placement have decreased in recent years. One of the complications involved with this procedure is the possibility that the stent is stripped from the delivery catheter prior to deployment and is lost systemically. This paper reports a rare complication which resulted in vascular insufficiency necessitating surgical intervention.

Predicting hospital mortality in cirrhotic patients: comparison of Child-Pugh and Acute Physiology, Age and Chronic Health Evaluation (APACHE III) scoring systems

OBJECTIVE

The severity of hepatic abnormalities and extent of dysfunction of other organ systems influences prognosis for cirrhosis. The Child-Pugh system has been used to classify cirrhotic patients into good, intermediate, or poor risk categories in evaluation and therapy. Disregard for cardiorespiratory, renal, electrolyte balance, and acid base status limits its predictive accuracy. We evaluated the accuracy of Acute Physiology and Chronic Health Evaluation (APACHE III) to predict short term hospital mortality in patients with liver cirrhosis.

METHODS

A total of 282 patients were prospectively enrolled. Child-Pugh and APACHE III scores were recorded on day 1 for each patient.

RESULTS

Mean age was 51.7+/-11.3 yr, with 65% men and 35% women; 57% presented with upper GI bleeding, 47% encephalopathy, 9% hepatorenal syndrome, and 7% hepatocellular carcinoma. Sixty-three patients (22%) died. Major causes of death were upper GI bleeding 38%, liver failure 21%, hepatorenal syndrome 19%, hepatocellular carcinoma 4%, and spontaneous bacterial peritonitis 6%. Child-Pugh and APACHE III scores for survivors (8.6+/-2.3 and 58.9+/-35.1) were lower than those for nonsurvivors (10.9+/-2.7 and 87.4+/-30.3) (p < 0.001). Using discriminant analysis, APACHE III correctly identified 75% of cases vs 67% of cases for Child-Pugh (p < 0.05). When information regarding ascites and prothrombin time was added to APACHE III, 81% of cases were correctly classified.

CONCLUSION

The APACHE III scoring system is superior to Child-Pugh for prognosticating short term survival of cirrhotic patients. Prognostic accuracy of APACHE III can be enhanced by incorporating information regarding ascites and prothrombin time prolongation.

Use of ketolides in combination with other drugs to treat experimental toxoplasmosis

Because combination therapy is required to treat human toxoplasmosis, we examined combinations of the ketolides HMR 3004 and HMR 3647 with atovaquone, clindamycin or sulphadiazine in a murine model of toxoplasmosis. An oral dose of 50 mg/kg/day of HMR 3004 protected 30% of mice lethally infected with Toxoplasma gondii. The same dose protected 100% of infected mice when administered in combination with non-protective doses of atovaquone, clindamycin or sulphadiazine. Similar results were noted with 25 mg/kg/day of HMR 3647. These results demonstrate that these drug combinations are highly effective for treating toxoplasmosis in mice.

Isolation and characterization of Enterobacter cloacae capable of metabolizing asparagine

A gram-negative, rod-shaped bacterium capable of utilizing L-asparagine as its sole source of carbon and nitrogen was isolated from soil and identified as Enterobacter cloacae. An intracellularly expressed L-asparaginase was detected and it deaminated L-asparagine to aspartic acid and ammonia. High-pressure liquid chromatography analysis of a cell-free asparaginase reaction mixture indicated that 2.8 mM L-asparagine was hydrolyzed to 2.2 and 2.8 mM aspartic acid and ammonia, respectively, within 20 min of incubation. High asparaginase activity was found in cells cultured on L-fructose, D-galactose, saccharose, or maltose, and in cells cultured on L-asparagine as the sole nitrogen source. The pH and temperature optimum of L-asparaginase was 8.5 and 37-42 degrees C, respectively. The half-life of the enzyme at 30 degrees C and 37 degrees C was 10 and 8 h, respectively.

Two 2-hydroxy-3-alkyl-1,4-naphthoquinones with in vitro and in vivo activities against Toxoplasma gondii

Two 3-alkyl-substituted 2-hydroxy-1,4-naphthoquinones, NSC 113452 (NSC52) and NSC 113455 (NSC55), were evaluated for activity against Toxoplasma gondii in vitro and in murine models of acute toxoplasmosis. In vitro, both NSC52 and NSC55 significantly inhibited intracellular replication of T. gondii. In vivo, each compound was examined alone and in combination with other drugs currently used for treatment of human toxoplasmosis. Although none of the compounds protected mice against death when administered orally, both were significantly protective when administered intraperitoneally. In addition, a significant increase in survival was observed when suboptimal doses of each compound were used in combination with suboptimal doses of pyrimethamine or sulfadiazine. These results indicate that combinations of NSC52 or NSC55 with pyrimethamine or sulfadiazine have promising activity against T. gondii.

Cortical variability and asymmetry in normal aging and Alzheimer's disease

The onset of Alzheimer's disease (AD) is accompanied by a complex and distributed pattern of neuroanatomic change, difficult to distinguish clinically from dynamic alterations in normal aging. Extreme variations in the sulcal patterns of the human cortex have made it difficult to identify diffuse and focal variations in cortical structure in neurodegenerative disease. We report the first comprehensive 3D statistical analysis of deep sulcal structure in vivo, in both normal aging and dementia. High-resolution 3D T1-weighted fast SPGR (spoiled GRASS) MRI volumes were acquired from 10 patients diagnosed with AD (NINCDS-ARDRA criteria; age: 71.9 +/- 10.7 years) and 10 normal subjects matched for age (72.9 +/- 5.6 years), gender, educational level and handedness. Scans were digitally transformed into Talairach stereotaxic space. To determine specific patterns of cortical variation in dementia patients, 3D average and probabilistic maps of primary deep sulci were developed for both normal and AD groups. Major sulci (including supracallosal, cingulate, marginal, parieto-occipital, anterior and posterior calcarine sulci, and Sylvian fissures) were modeled as complex systems of 3D surfaces using a multi-resolution parametric mesh approach. Variations and asymmetries in their extents, curvature, area and surface complexity were evaluated. Three-dimensional maps of anatomic variability, structural asymmetry and local atrophy indicated severe regionally selective fiber loss in AD. A midsagittal area loss of 24.5% at the corpus callosum's posterior midbody (P < 0.025) matched increases in structural variability in corresponding temporo-parietal projection areas. Confidence limits on 3D cortical variation, visualized in 3D, exhibited severe increases in AD from 2 to 4 mm at the callosum to a peak SD of 19.6 mm at the posterior left Sylvian fissure. Normal Sylvian fissure asymmetries (right higher than left; P < 0.0005), mapped for the first time in three dimensions, were accentuated in AD (P < 0.0002), and were greater in AD than in controls (P < 0.05). Severe AD-related increases in 3D variability and asymmetry may reflect disease-related disruption of the commissural system connecting bilateral temporal and parietal cortical zones, regions known to be at risk of early metabolic dysfunction, perfusion deficits and selective neuronal loss in AD.

Band ligation vs endoscopic sclerotherapy in esophageal varices: a prospective randomized comparison

OBJECTIVE

A prospective randomized trial was conducted to compare efficacy, safety and complications of band ligation (BL) with sclerotherapy (Scl).

METHODS

Patients with esophageal variceal bleeding were randomized into two study groups. BL (group A) was done in 28 patients whereas 30 patients (group B) had Scl. After initial treatment, follow-up sessions were repeated by the same method every two weeks till obliteration or reduction to grade 1. Subsequent sessions of endoscopy were done every three months, same procedure was repeated for recurrence of varices and for any episode of rebleeding.

RESULTS

Initial control of bleeding by Scl was achieved in 22 of 28 patients (78%) and in 23 of 24 patients (96%) with BL. Eradication of varices was significantly better achieved in BL group, with less treatment sessions required in Group A as compared with group B 2 +/- 1.2 vs 5 +/- 2.5, P < 0.001). Major complications (3% vs 16%, P < 0.05) as well as mortality (11% vs 21%, P > 0.05) was higher in group B.

CONCLUSION

Band ligation was more effective mode of treatment and was associated with lesser early mortality and complications as compared with sclerotherapy.

Molecular cloning, nucleotide sequence, and expression in Escherichia coli of a hemolytic toxin (aerolysin) gene from Aeromonas trota

Aeromonas trota AK2, which was derived from ATCC 49659 and produces the extracellular pore-forming hemolytic toxin aerolysin, was mutagenized with the transposon mini-Tn5Km1 to generate a hemolysin-deficient mutant, designated strain AK253. Southern blotting data indicated that an 8.7-kb NotI fragment of the genomic DNA of strain AK253 contained the kanamycin resistance gene of mini-Tn5Km1. The 8.7-kb NotI DNA fragment was cloned into the vector pGEM5Zf(-) by selecting for kanamycin resistance, and the resultant clone, pAK71, showed aerolysin activity in Escherichia coli JM109. The nucleotide sequence of the aerA gene, located on the 1.8-kb ApaI-EcoRI fragment, was determined to consist of 1,479 bp and to have an ATG initiation codon and a TAA termination codon. An in vitro coupled transcription-translation analysis of the 1.8-kb region suggested that the aerA gene codes for a 54-kDa protein, in agreement with nucleotide sequence data. The deduced amino acid sequence of the aerA gene product of A. trota exhibited 99% homology with the amino acid sequence of the aerA product of Aeromonas sobria AB3 and 57% homology with the amino acid sequences of the products of the aerA genes of Aeromonas salmonicida 17-2 and A. sobria 33.

Unusual clinical variants of cutaneous leishmaniasis in Pakistan

Cutaneous leishmaniasis is endemic in the Baluchistan province of Pakistan and poses a great risk to non-immune visitors to the area. The wide spectrum of clinical variants of this common disease is at times a diagnostic challenge. A total of 1709 patients with cutaneous leishmaniasis were recorded over a 1-year period. In 37 (2%) patients the lesions were very unusual, and therefore worth reporting. These included acute paronychial, chancriform, annular, palmoplantar, zosteriform and erysipeloid forms. The zosteriform and erysipeloid forms have rarely been reported previously, but to the best of our knowledge, acute paronychial, chancriform, annular and palmoplantar lesions are being reported for the first time. The morphologically unusual lesions may be attributed to an altered host response or involvement of an atypical strain of parasite in these lesions.

Hiatal hernia in achalasia

Barium esophagograms of 89 patients out of 110 with manometrically proven achalasia were reviewed. Only four (4.4%) patients showed association of hiatal hernia, indicative of its rare occurrence. Presence of hiatal hernia, is said to have less likelihood of associated achalasia but this association does exist as per our report and that of others.

Pneumatic balloon dilation in achalasia: a prospective comparison of balloon distention time

OBJECTIVE

Duration of Inflation in pneumatic balloon dilatation as treatment of achalasia has been variable ranging from 15 s to 6 min. A 60 s duration appears to be most often used. We compared the efficacy of dilation of achalasia with either 6- or 60-s inflation duration using a Rigiflex dilator of 3.0 cm diameter.

METHODS

Eighty-one consecutive patients were prospectively studied in a randomized fashion, 41 in the 60-s group (A) and 40 patients in the 6-s group (B). Mean age of group A was 43 +/- 16.2 yr and of group B was 40 +/- 16.4 yr. Symptoms of dysphagia, chest pain, heartburn, regurgitation, and night cough were evaluated at basal (before dilation), 1- and 6-month intervals after dilation in both groups. Barium swallow was done to assess esophageal emptying 1 wk before dilation and 5 min postdilation in both groups.

RESULTS

Significant and sustained improvement was seen for all symptoms in both groups. In addition, the degree of improvement in symptom scores between the two groups was similar. Barium esophagram in both groups at basal and immediately postdilation showed significant improvement in barium emptying but there was no significant difference between the two groups, indicative of equal efficacy in both distention times. Two patients needed repeat dilatation in group A and one in group B, with one drop out from group A, who was lost to follow-up, and was excluded from the analysis. No perforation occurred.

CONCLUSION

Short duration of pneumatic balloon dilatation (6-s) is as effective as longer duration (60-s) in treatment of achalasia.

Hepatocellular carcinoma: analysis of 76 cases

Hepatocellular carcinoma is one of the most common malignancies world wide. We present data on 76 patients admitted to the Shaikh Zayed Hospital. Mean age was 52.2 +/- 11.3 years. Eighty six percent were males and 14% females. Eighty-six percent patients had underlying cirrhosis documented on ultrasound examination. Seventy-five percent were positive for anti HCV, 10% for HBsAg positive, 10% for both HBsAg and anti HCV and 5% cases had negative viral serology. Main clinical features were abdominal pain, weight loss, jaundice, hepatomegaly and ascites. Forty-three percent patients were Child-Pugh class A, 30% class B and 13% class C and 14% were non cirrhotic. Mean alfa fetoprotein levels were 142 +/- 155 ng/ml (range 2.7 to 1470). Diagnosis of hepatocellular carcinoma was established in 60 patients by fine needle aspiration biopsy under ultrasound guidance. Two patients died after biopsy due to uncontrollable bleeding. Fifty-four percent patients had a solitary lesion and 46% had multifocal or diffuse lesions. The average size of lesion was 7.8 x 8.1 cm. Twenty-two patients received intralesional alcohol injection. Fifty-four percent of these with a tumor size greater than 8 cm died during follow up. The major cause of death was liver failure in 8 patients and fatal bleeding occurred in 4 patients. Hepatocellular carcinoma has a high prevalence in middle aged males with a strong association with anti HCV positive cirrhosis. Patients with a tumour size greater than 8 cm have a poor response to intralesional alcohol injection.

Effect of trovafloxacin on production of cytokines by human monocytes

Antibiotics have previously been shown to have immunomodulatory effects. We examined the effect of the broad-spectrum fluoroquinoline antibiotic trovafloxacin on cytokine synthesis by monocytes obtained from healthy human volunteers and stimulated with either lipopolysaccharide or gram-positive cells (heat-killed Staphylococcus aureus [Pansorbin]). Trovafloxacin levels achievable in humans suppressed in vitro synthesis of each of the cytokines analyzed, viz., interleukin-1 alpha (IL-1 alpha), IL-1 beta, IL-6, IL-10, granulocyte-macrophage colony-stimulating factor, and tumor necrosis factor alpha. This effect was not due to direct effects of the drug on cellular viability; at these concentrations, trovafloxacin did not have demonstrable cytotoxicity for the monocytes, as determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay. Although similar patterns of suppression of cytokine synthesis were observed in samples obtained from the same volunteers on different days, there were significant day-to-day variations. These results reveal that trovafloxacin possesses significant immunomodulatory activity in vitro and suggest that suppression of acute-phase inflammatory responses may occur in vivo, elicited through trovafloxacin's effect on cytokine synthesis by human monocytes.

Independent prognostic significance of ischemic ST-segment response limited to recovery from treadmill exercise in asymptomatic subjects

BACKGROUND

Although exercise-induced ST depression is an independent predictor of future coronary events in asymptomatic populations, the predictive value of ST depression beginning after exercise cessation is unknown.

METHODS AND RESULTS

We analyzed the treadmill exercise tests of 825 healthy volunteers who were 22 to 89 years of age from the Baltimore Longitudinal Study of Aging. All subjects were free from coronary heart disease by history, physical examination, and resting ECG. From 825 participants, 611 (group 0) had no ischemic ST-segment changes during or after treadmill exercise, while 214 subjects developed > or = 1-mm flat or downsloping ST depression: 151 (group 1) had ST changes starting during exercise, and 63 (group 2) had changes limited to recovery. Groups 1 and 2 were similar in age, sex, smoking status, hypertension prevalence, fasting plasma glucose, and serum cholesterol (CHOL). However, both groups were older and had higher CHOL and prevalence of hypertension than group 0. Treadmill exercise duration, peak oxygen consumption, and maximal heart rate were similar between groups 1 and 2 but were lower than in group 0 (each P < 0.05). During a mean follow-up time of 9 years, 55 subjects developed coronary events (angina pectoris, myocardial infarction, or coronary death): 21 of 611 (3.4%) in group 0, 22 of 151 (14.6%) in group 1, and 12 of 63 (19%) in group 2 (P = 0.001). By survival analysis, the risk of coronary events was similar in groups 1 and 2 but significantly higher than in group 0 (P < 0.0001). Multiple logistic regression showed that age (odds ratio [OR] = 1.07 per year, P = 0.00001), CHOL (OR = 1.02 per 1 mg, P = 0.0001), and presence of ST-segment depression (OR = 2.59, P = 0.007 and OR = 2.38, P = 0.04 for groups 1 and 2, respectively) were independent predictors of events.

CONCLUSIONS

Thus, ischemic ST-segment changes developing during recovery from treadmill exercise in apparently healthy individuals have adverse prognostic significance similar to those appearing during exercise.

Rapid method for the detection of genetically engineered microorganisms by polymerase chain reaction from soil and sediments

A rapid and sensitive method for the detection of genetically engineered microorganisms in soil and sediments has been devised by in vitro amplification of the target DNAs by a polymerase chain reaction. A cloned catechol 2,3-dioxygenase gene located on the recombinant plasmid pOH101 was transferred to Pseudomonas putida MMB2442 by triparental crossing and used as a target organism. For the polymerase chain reaction from soil and sediment samples, the template DNA was released from a 100-mg soil sample. Bacterial seeded soil samples were washed with Tris-EDTA buffer (pH 8.0) and treated with a detergent lysis solution at 100 degrees C. After addition of 1% polyvinylpolypyrrolidine solution, the samples were boiled for 5 min. Supernatant containing nucleic acid was purified with a PCR purification kit. The purified DNA was subjected to polymerase chain reaction, using two specific primers designed for the amplification of catechol 2,3-dioxygenase gene sequences. The detection limit was 10(2) cells per gram of soil. This method is rapid and obviates the need for lengthy DNA purification from soil samples.

Glyceraldehyde-3-phosphate dehydrogenase: nuclear translocation participates in neuronal and nonneuronal cell death

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) protein levels increase in particulate fractions in association with cell death in HEK293 cells, S49 cells, primary thymocytes, PC12 cells, and primary cerebral cortical neuronal cultures. Subcellular fractionation and immunocytochemistry reveal that this increase primarily reflects nuclear translocation. Nuclear GAPDH is tightly bound, resisting extraction by DNase or salt treatment. Treating primary thymocytes, PC12 cells, and primary cortical neurons with antisense but not sense oligonucleotides to GAPDH prevents cell death. Because cell-death-associated nuclear translocation of GAPDH and antisense protection occur in multiple neuronal and nonneuronal systems, we propose that GAPDH is a general mediator of cell death and uses nuclear translocation as a signaling mechanism.

Detection of erythromycin resistant methylase gene by the polymerase chain reaction

A polymerase chain reaction (PCR) protocol was developed that could specifically amplify a 520-bp region of the erythromycin resistant methylase (ermC) gene sequence. The identity of the PCR-amplified 520-bp DNA was confirmed by HinCII endonuclease restriction digestion, which produced the predicted 440-bp and 80-bp DNA fragments. A 20-mer (alpha-32P) oligonucleotide probe specifically hybridized with these amplified products confirming the specificity and reliability of this diagnostic assay. The assay could detect the ermC gene in bacterial suspensions containing as few as 10(3) cells ml-1. The assay was used to detect the presence of the ermC gene in several Gram-positive bacterial strains identified as Streptococcus sp., Staphylococcus sp., Micrococcus sp., Lactobacillus sp. and Enterococcus sp., isolated from water samples maintained in experimental animal cages and clinical sources. Only bacteria identified as Staphylococcus sp. were resistant to the antibiotic. Although 17 strains of Staphylococcus sp. isolated from clinical samples were resistant to erythromycin, only seven of these isolates tested positive for the presence of the ermC gene. Of these strains, five were identified as coagulase-positive S. aureus and the rest were identified as coagulase-negative S. epidermidis. The erythromycin resistance in all seven ermC positive isolates was constitutive. The entire diagnostic assay, including template preparation, amplification and electrophoresis can be completed within 6 h.

Pemphigus vulgaris autoantibody response is linked to HLA-DQB1*0503 in Pakistani patients

Pemphigus vulgaris (PV) is an autoimmune disease of the skin and mucous membranes characterized by an autoantibody response against an epidermal cadherin. We performed high resolution HLA class II typing in 19 patients with PV from Rawalpindi, Pakistan and 19 non-Jewish European PV patients from Boston by sequence-specific oligonucleotide probe hybridization. The results were compared with two separate ethnically matched control populations. WE found that PV patients from Pakistan had significantly increased frequencies of DRB1*1404 (p = 0.01), DQA1*0101 (p = 0.02), and DQB1*0503 (p = 0.01). Among the patients of non-Jewish European ancestry, DRB1*1401 (p < 10(-6)), DQA1*0101 (p < 10(-5)) and DQB1*0503 (p < 10(-6)), were increased in PV patients. Formal linkage analysis between the major histocompatibility complex and the PV antibody was performed in 67 relatives of the 19 Pakistani patients. The results showed strong evidence for linkage of HLA-DRB1*1404, DQA1*0101, DQB1*0503, with the presence of PV antibody in relatives' families with a significant logarithm of the odds score of 6.06. Based on the three dimensional structure of class II molecules, we propose that HLA-DQA1*0101 and DQB1*0503, encode a negatively charged P9 peptide binding pocket of the DQ molecule and are significantly associated with susceptibility to PV in non-Jewish populations.

The ketolide antibiotics HMR 3647 and HMR 3004 are active against Toxoplasma gondii in vitro and in murine models of infection

Ketolides are a new class of macrolide antibiotics that have been shown to be active against a variety of bacteria including macrolide-resistant bacteria and mycobacteria. We examined two ketolides, HMR 3647 and HMR 3004, for their in vitro and in vivo activities against the protozoan parasite Toxoplasma gondii. In vitro, both ketolides at concentrations as low as 0.05 microg/ml markedly inhibited replication of tachyzoites of the RH strain within human foreskin fibroblasts. HMR 3004 demonstrated some toxicity for host cells after they were exposed to 5 microg of the drug per ml for 72 h. In contrast, HMR 3647 did not show any significant toxicity even at concentrations as high as 25 microg/ml. In vivo, both ketolides provided remarkable protection against death in mice lethally infected intraperitoneally with tachyzoites of the RH strain or orally with tissue cysts of the C56 strain of T. gondii. A dosage of 100 mg of HMR 3647 per kg of body weight per day administered for 10 days protected 50% of mice infected with tachyzoites. The same dosage of HMR 3004 protected 100% of the mice. In mice infected with cysts, a dosage of 30 mg of HMR 3647 per kg per day protected 100% of the mice, whereas a dosage of 40 mg of HMR 3004 per kg per day protected 75% of the mice. These results demonstrate that HMR 3647 and HMR 3004 possess excellent activities against two different strains of T. gondii and may be useful for the treatment of toxoplasmosis in humans.

Nucleotide sequence of the gene encoding cis-biphenyl dihydrodiol dehydrogenase (bphB) and the expression of an active recombinant His-tagged bphB gene product from a PCB degrading bacterium, Pseudomonas putida OU83

The nucleotide sequence of the bphB gene of Pseudomonas putida strain OU83 was determined. The bphB gene, which encodes cis-biphenyl dihydrodiol dehydrogenase (BDDH), was composed of 834 base pairs with an ATG initiation codon and a TGA termination codon. It can encode a polypeptide of 28.91 kDa, containing 277 amino acids. Promoter-like and ribosome-binding sequences were identified upstream of the bphB gene. The bphB nucleotide sequence was used to produce His-tagged BDDH, in Escherichia coli. The His-tagged BDDH construction, carrying a single 6 x His tail on the N-terminal portion, was active. The molecular mass of the native enzyme was 128 kDa and on SDS-PAGE analysis the molecular mass was 31 kDa. This enzyme requires NAD+ for its activity and its optimum pH is 8.5. Nucleotide and the deduced amino acid sequence analyses revealed a high degree of homology between the bphB gene from Pseudomonas putida OU83 and the bphB genes from P. cepacia LB400 and P. pseudoalcaligenes KF707.