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Biomedical subjects

D Wolf

Publications and source records attributed to D Wolf.

At least 145 records · Page 8Linked to original sources

Ciprofloxacin in the treatment of acute bacterial diarrhea: a double blind study.

In a double-blind, randomized, placebo-controlled trial 50 adult patients with acute diarrhea received either 500 mg ciprofloxacin b.i.d. or a placebo for five days. Results were evaluated in 21 patients in the ciprofloxacin group (10 with Salmonella spp., 11 with Campylobacter jejuni) and 25 patients in the placebo group (16 with Salmonella spp., 5 with Campylobacter jejuni, 4 with Shigella spp.). The duration of fever in patients treated with ciprofloxacin was 1.5 days versus 2.3 days in the placebo group; the difference was not statistically significant. The duration of diarrhea in the ciprofloxacin group was 1.4 days versus 2.6 days in the placebo group (p less than 0.01); the corresponding figures in patients with salmonellosis were 1.6 versus 3.2 (p = 0.01). In the ciprofloxacin group all stool cultures became negative 48 h after start of treatment and remained negative during the follow-up period of three weeks. In the placebo group only one of the 25 patients had negative stool cultures during therapy and only seven after the treatment period (p less than 0.001). Ciprofloxacin was very well tolerated and was found to be a safe compound without major adverse effects.

Acute Disease↗

Molecular basis for heterogeneity of the human p53 protein.

The human p53 tumor antigen comprises several physically distinct proteins. Two p53 proteins, separable by polyacrylamide gel electrophoresis, are expressed by the human transformed cell line SV-80. The individual cDNAs which code for these proteins were isolated and constructed into the SP6 transcription vector. The proteins encoded by these clones were identified by in vitro transcription with the SP6 vector and translation in a cell-free system. p53-H-1 and p53-H-19 cDNA clones code for the faster- and slower-migrating p53 protein species, respectively, of SV-80. The in vitro-expressed proteins of p53-H-1 and p53-H-19 had the same antigenic determinants and were structurally indistinguishable from their in vivo counterparts. By expressing defined restricted cDNA fragments in vitro, the region of heterogeneity between the respective cDNAs was located at the 5' end of the cDNAs. Exchanging the 5' fragments of interest and expressing the chimeric clones in vitro confirmed that the DNA heterogeneity was responsible for the difference in the electrophoretic mobility of these proteins. The sequences of the two cDNAs revealed a single base pair difference (G versus C) in the coding region of the clones. This sequence difference resulted in an arginine being coded for in clone p53-H-1 and a proline being coded for at the equivalent position in clone p53-H-19. This variation accounted for the change in the electrophoretic mobility of the individual p53 protein species.

Amino Acid Sequence↗

Immunologically distinct p53 molecules generated by alternative splicing.

Transfection of a functional cloned p53 gene into an L12 p53 nonproducer cell line efficiently reconstituted p53 expression. The p53 protein synthesized in these clones was indistinguishable from that occurring naturally in tumor cells. When a p53 cDNA clone was used instead, we observed that the L12-derived clones exhibited a distinct immunological profile. In the present experiments we compared the immunological epitopes of p53 proteins encoded by several full-length cDNA clones. Immunoprecipitation of p53 proteins generated by in vitro transcription and translation of the various cDNA clones indicated variations in the content of immunological epitopes. Basically, two p53 protein species were detected. Both species contained the same antigenic determinants except the PAb421-PAb122 site, which was present in proteins encoded by p53-M11 and pcD-p53, but not in the p53 protein encoded by the p53-M8 cDNA clone. Sequence analysis of the various cDNA clones indicated the existence of a 96-base-pair (bp) insert in clone p53-M8 as compared with clone p53-M11 or pCD-p53. The 96-bp insert contained a termination signal which caused the premature termination of the protein, leading to the generation of a p53 product 9 amino acids shorter than usual. The existence of this insert also accounted for the lack of the PAb421-PAb122 epitope which was mapped to the 3' end of the cDNA clone, following the 96-bp insert. This insert shared complete homology with the p53 intron 10 sequences mapping 96 bp upstream of the 5' acceptor splicing site of p53 exon 11. It was therefore concluded that the different cDNA clones represented p53 mRNA species which were generated by an alternative splicing mechanism. Differential hybridization of the mRNA population of transformed fibroblastic or lymphoid cells with either the 96-bp synthetic oligonucleotide or the p53-M11 cDNA indicated that the various mRNA species are expressed in vivo.

Abelson murine leukemia virus↗

Expression of p53 in human leukemia and lymphoma.

Analysis of fresh human tumors have indicated that patients with B type lymphoproliferative diseases and the majority of patients with acute lymphoblastic leukemia (ALL) express elevated levels of p53 production. It is suggested that in these human malignancies, p53 may provide a novel tool for monitoring cancer activity. Conversely, p53 is not expressed in acute myeloid leukemias, myeloproliferative diseases, or myeloid leukemic cell lines. Analysis of the p53 gene structure indicated the existence of similar patterns of p53 restriction fragments in producer and nonproducer cells, which suggests that the p53 gene is not altered in the latter. However, in one case of acute promyelocytic leukemia (APL), we have observed a rearrangement in the p53 gene. Karyotype analysis has indicated that these APL cells do not contain the typical 15;17 translocation. In other APL patients who exhibit a 15;17 translocation, we found no genomic changes of the p53, suggesting that the p53 gene, which was recently mapped to the short arm of chromosome 17 in the human, is not structurally related to the typical chromosomal break point found in the long arm of chromosome 17 of APL patients.

Antibodies, Monoclonal↗

Presynaptic inhibitory opioid delta- and kappa-receptors in a branch of the rabbit ileocolic artery.

The largest rami caecales of the ileocolic artery (a branch of the mesenteric artery) were perfused at a constant rate of flow. Either vasoconstriction or the release of previously incorporated [3H]noradrenaline was measured. The following opioid agonists inhibited the vasoconstriction elicited by electrical field pulses (5 pulses at 10 Hz; EC50 values in brackets): [Leu5]enkephalin (596 nmol/l), [D-Ala2,D-Leu5]enkephalin (69 nmol/l), dynorphin-(1-13) (366 nmol/l) and ethylketocyclazocine (668 nmol/l). Fentanyl (up to 30 mumol/l) and normorphine (up to 100 mumol/l) caused at best minimal inhibition. The effects of [Leu5]enkephalin and dynorphin-(1-13) were antagonized by naloxone. Only the effect of [Leu5]enkephalin but not that of dynorphin-(1-13) was antagonized by the delta-selective antagonist ICI 154129. [Leu5]Enkephalin and dynorphin-(1-13) did not decrease the vasoconstrictor response to exogenous noradrenaline or ATP. In arteries preincubated with [3H]noradrenaline, electrical stimulation (50 pulses at 1 Hz) increased the outflow of tritium. The stimulation-evoked overflow was reduced by [Leu5]enkephalin and dynorphin-(1-13), and the effect of [Leu5]enkephalin was antagonized by naloxone. It is concluded that the postganglionic sympathetic neurons of the ramus caecalis possess presynaptic opioid receptors which, when activated, inhibited transmitter release. The receptors appear to be of the delta- and kappa- but not the mu-type.

Animals↗

Incidence of bacteremia with elective upper gastrointestinal endoscopic laser therapy.

The incidence of bacteremia associated with endoscopy varies widely for different endoscopic procedures. This study prospectively evaluates the incidence of bacteremia in patients undergoing elective endoscopic laser therapy for two diseases of the upper gastrointestinal tract. In five patients (eight treatment sessions) with arteriovenous malformations, no bacteremia developed. In 15 patients (26 treatment sessions) with esophagogastric carcinoma, bacteremia developed at some time during the procedure in six (40%). However, bacteremia appeared to be associated with the endoscopic insertion through the tumor rather than the laser treatment per se. These findings lead us to conclude that for patients undergoing endoscopy and laser therapy for esophagogastric malignancy, but not for those being treated for arteriovenous malformations, antibiotic prophylaxis to prevent endocarditis may be indicated.

Anti-Bacterial Agents↗

Major deletions in the gene encoding the p53 tumor antigen cause lack of p53 expression in HL-60 cells.

The tumor antigen p53 is overproduced in transformed cells of various species, including man. HL-60 is an exceptional human tumor cell line that does not express this protein. Hybridization of polyadenylylated mRNA of these cells with a human p53 cDNA probe (p53-H14), which we cloned, had indicated a total absence of the mature-size (3.0 kilobases) or any aberrant p53 mRNA species. Analysis of the genomic HL-60 DNA indicated that the p53 gene in these cells was significantly altered. Most of the gene was deleted, and the residual p53 sequences of these cells, which show weak homology, mapped to the corresponding 5' region of the p53 gene. In agreement with previously documented results, we found that HL-60 cells have an amplified c-myc gene. We suggest that the deficiency of the p53 protein in HL-60 cells could have been overcome by using an alternative metabolic pathway. The c-myc product is a candidate for such an alternative protein.

Animals↗

Norwegian-type scabies mimicking contact dermatitis in an immunosuppressed patient.

Patients taking immunosuppressive drugs are susceptible to various forms of infection, including dermatologic disease. Recently, atypical manifestations of scabies have been reported in such patients. In the case reported here, a 26-year-old woman who had had a renal transplant and was taking immunosuppressive drugs had a pruritic rash on the back that closely resembled contact dermatitis. However, skin scrapings from the involved areas and punch biopsy specimen of the back showed live scabies mites. The pruritus was relieved and the skin lesions disappeared within ten days of treatment with scabicides. We believe that current widespread use of immunosuppressive agents may result in more cases of atypical forms of scabies. Therefore, physicians who deal with immunosuppressed patients should be aware of this possibility.

Adult↗

Isolation of a full-length mouse cDNA clone coding for an immunologically distinct p53 molecule.

Transfection of a cloned p53 gene into a p53 nonproducer Abelson murine leukemia virus-transformed cell line, L12, reconstituted p53 expression. The protein expressed in these cells was indistinguishable from that naturally expressed in p53 producer tumor cells. Conversely, p53 protein expressed in L12-derived clones that were established by transfection with a full-length p53 cDNA clone (pM8) exhibited a discrete immunological form. Immunoprecipitation of p53 with a panel of monoclonal anti-p53 antibodies showed that L12-derived clones that were transfected with the genomic p53 clone contained the same antigenic determinants as those found in the p53 protein expressed in tumor cells. These p53 proteins bound all monoclonal antibody types as well as the polyclonal anti-p53 tested. However, L12-derived clones established by transfection of the p53 cDNA clone (pM8) expressed a p53 protein that bound the RA3-2C2 and PAb200.47 anti-p53 monoclonal antibodies as well as polyclonal anti-p53 serum but totally lacked the antigenic receptor for the PAb122 and PAb421 monoclonal antibodies. The p53 proteins expressed by either genomic or cDNA p53 clones exhibited the same apparent molecular sizes and identical partial peptide maps. We suggest that transfection of the p53 gene induced expression of the entire group of the possible mRNA species, whereas cloned p53 cDNA (pM8) represented a single mRNA molecule that codes for a discrete species of p53 protein.

Animals↗

In vitro expression of human p53 cDNA clones and characterization of the cloned human p53 gene.

The human p53 gene was cloned and characterized by using a battery of p53 DNA clones. A series of human cDNA clones of various sizes and relative localizations to the mRNA molecule were isolated by using the human p53-H14 (2.35-kilobase) cDNA probe which we previously cloned. One such isolate, clone p53-H7 (2.65 kilobases), spans the entire human mature p53 mRNA molecule. Construction of the human cDNA clones in the pSP65 RNA transcription vector facilitated the generation of p53 transcripts by the SP6 bacteriophage RNA polymerase. The p53-specific RNA transcripts obtained without further processing were translated into p53 proteins in a cell-free system. By using this rapid in vitro transcription-translation assay, we found that whereas clone p53-H7 (2.65 kilobases) coded for a mature-sized p53 protein, a shorter cDNA clone, p53-H13 (1.8 kilobases), dictated the synthesis of a smaller-sized p53 protein (45 kilodaltons). The p53 proteins synthesized in vitro immunoprecipitated efficiently with human-specific anti-p53 antibodies. Genomic analysis of human DNA revealed the presence of a single p53 gene residing within two EcoRI fragments. Heteroduplex analysis between the full-length cDNA clone p53-H7 and the cloned p53 gene indicated the presence of seven major exons.

Cell Line↗

Pityriasis rosea and ketotifen.

A 4-year-old female patient who developed a skin eruption similar to pityriasis rosea after treatment with ketotifen (Zaditen) is presented. The relationship between ketotifen and the eruption has been based on circumstantial evidence and confirmed by the positive results of the MIF test and the rat mast cell degranulation test.

Bronchitis↗

Studies on equine recurrent uveitis. II: The role of infection with Leptospira interrogans serovar pomona.

An enzyme linked immunosorbent assay was developed for the detection of immunoglobulin class specific antibodies to Leptospira interrogans serovar pomona in the serum and aqueous humor of horses. Serum antibody was also assayed by microscopic agglutination tests. Although higher levels of antibody were found in sera from horses with signs of uveitis, the association was not statistically significant. Antibodies to pomona were detected in the aqueous of 12 eyes from the 101 horses sampled at a slaughterhouse, and in most instances, a comparison of the aqueous/serum antibody level with that of the total aqueous/serum IgG level indicated intraocular antibody synthesis. Antibodies were also found in 4 aqueous (or vitreous) samples out of 9 obtained from horses with clinically documented uveitis and the above comparison again indicated intraocular antibody synthesis. The data point to an important role for pomona as an etiology of equine recurrent uveitis but also emphasize that the initiating cause for this disease is often obscure in that association with leptospirosis cannot be shown in many instances.

Agglutination Tests↗