Randomized trial of tacrolimus (Prograf) in combination with azathioprine or mycophenolate mofetil versus cyclosporine (Neoral) with mycophenolate mofetil after cadaveric kidney transplantation

BACKGROUND

Our clinical trial was designed to investigate the optimal combination of immunosuppressants for renal transplantation.

METHODS

A randomized three-arm, parallel group, open label, prospective study was performed at 15 North American centers to compare three immunosuppressive regimens: tacrolimus + azathioprine (AZA) versus cyclosporine (Neoral) + mycophenolate mofetil (MMF) versus tacrolimus + MMF. All patients were first cadaveric kidney transplants receiving the same maintenance corticosteroid regimen. Only patients with delayed graft function (32%) received antilymphocyte induction. A total of 223 patients were randomized, transplanted, and followed for 1 year.

RESULTS

There were no significant differences in baseline demography between the three treatment groups. At 1 year the results are as follows: acute rejection 17% (95% confidence interval 9%, 26%) in tacrolimus + AZA; 20% (confidence interval 11%, 29%) in cyclosporine + MMF; and 15% (confidence interval 7%, 24%) in tacrolimus + MMF. The incidence of steroid resistant rejection requiring antilymphocyte therapy was 12% in the tacrolimus + AZA group, 11% in the cyclosporine + MMF group, and 4% in the tacrolimus + MMF group. There were no significant differences in overall patient or graft survival. Tacrolimus-treated patients had a lower incidence of hyperlipidemia through 6 months posttransplant. The incidence of posttransplant diabetes mellitus requiring insulin was 14% in the tacrolimus + AZA group, 7% in the cyclosporine + MMF and 7% in the tacrolimus + MMF groups.

CONCLUSIONS

All regimens yielded similar acute rejection rates and graft survival, but the tacrolimus + MMF regimen was associated with the lowest rate of steroid resistant rejection requiring antilymphocyte therapy.

Low-copy-number plasmid-cloning vectors amplifiable by derepression of an inserted foreign promoter

By insertion of a DNA fragment, containing the phage lambda pR promoter and the pM-promoted cI857 allele of the lambda repressor gene, in plasmid R1 upstream of the replication control genes, cloning vectors have been constructed which are present in one copy per chromosome at temperatures below 37 degrees C, and which display uncontrolled replication at 42 degrees C. Derivatives have been made which carry the R1 par region, stabilizing the plasmid at low temperature when grown in the absence of selection pressure. Cells harbouring these plasmids stop growing after 1-2 h incubation at 42 degrees C, and at this time 50% of the total DNA in the cells is plasmid DNA corresponding to more than 1000 plasmid molecules per cell. Concomitant with plasmid amplification at the high temperature, synthesis of plasmid-coded gene products is amplified, and these vectors can therefore be utilized for obtaining greatly enhanced yields of gene products that may be detrimental to the host cell when present in large amounts.

Control of replication of bacterial plasmids: genetics, molecular biology, and physiology of the plasmid R1 system

Plasmids are autonomously replicating DNA molecules that are present in defined copy numbers in bacteria. This number may for some plasmids be very low (2-5 per average cell). In order to be stably inherited, replication and partitioning of the plasmid have to be strictly controlled. Plasmids carry genetic information for both processes. In the present paper we summarize what is known about the replication control system of one low-copy-number plasmid, R1, belonging to the FII incompatibility group. We do so because the FII group seems to be one of the best understood examples with respect to genetics, molecular biology, and physiology of the replication control system. The paper is not a classical review, but rather an essay in which we discuss the aspects of replication control that we regard as being important.

Randomized trial of tacrolimus plus mycophenolate mofetil or azathioprine versus cyclosporine oral solution (modified) plus mycophenolate mofetil after cadaveric kidney transplantation: results at 2 years

BACKGROUND

A previous report described the 1-year results of a prospective, randomized trial designed to investigate the optimal combination of immunosuppressants in kidney transplantation. Recipients of first cadaveric kidney allografts were treated with tacrolimus+mycophenolate mofetil (MMF), cyclosporine oral solution (modified) (CsA)+MMF, or tacrolimus+azathioprine (AZA). Results at 1 year revealed that optimal efficacy and safety were achieved with a regimen containing tacrolimus+MMF. The present report describes results at 2 years.

METHODS

Two hundred twenty-three recipients of first cadaveric kidney allografts were randomized to receive tacrolimus+MMF, CsA+MMF, or tacrolimus+AZA. All regimens contained corticosteroids, and antibody induction was used only in patients who experienced delayed graft function. Patients were followed up for 2 years.

RESULTS

The results at 2 years corroborate and extend the findings of the previous report. Patients randomized to either treatment arm containing tacrolimus experienced improved kidney function. New-onset insulin dependence remained in four, three, and four patients in the tacrolimus+MMF, CsA+MMF, and tacrolimus+AZA treatment arms, respectively. Furthermore, patients with delayed graft function/acute tubular necrosis who were treated with tacrolimus+MMF experienced a 23% increase in allograft survival compared with patients receiving CsA+MMF (P=0.06). Patients randomized to tacrolimus+MMF received significantly lower doses of MMF compared with those administered CsA+MMF.

CONCLUSIONS

All three immunosuppressive regi-mens provided excellent safety and efficacy. How-ever, the best results overall were achieved with tacrolimus+MMF. The combination may provide particular benefit to kidney allograft recipients who develop delayed graft function/acute tubular necrosis. Renal function at 2 years was better in the tacrolimus treatment groups compared with the CsA group.

Post-transcriptional control of expression of the repA gene of plasmid R1 mediated by a small RNA molecule

Fusions between the repA gene of plasmid R1 (required for autonomous plasmid replication) and the lac genes have been the basis for in vivo studies of regulation of repA expression. Two gene products--the CopA RNA and the CopB protein--act as inhibitors of repA expression. Comparison of the effects of addition in trans of the two Cop functions on transcription and translation of repA-lac gene fusions show that the CopB protein represses transcription of the repA gene, whereas the CopA RNA interferes with the RepA mRNA in such a way that effective translation is inhibited. The CopA RNA does not seem to have a direct effect on the transcription of the repA gene but, as a consequence of the posttranscriptional regulation, transcriptional polarity within the repA gene is observed. It is also shown that the CopA RNA interacts with its target (CopT) only when the region is transcribed to form RepA mRNA.

Health-related quality of life among patients with facial acne -- assessment of a new acne-specific questionnaire

The psychosocial effects of facial acne are well accepted but until recently few validated instruments existed which were suitable for use in clinical trials. The aim of this study was to assess measurement characteristics (reproducibility, correlation with acne severity, and sensitivity to detect change after acne therapy) of a new acne-specific quality of life instrument, the Acne-QoL. We found that the Acne-QoL is reliable, valid and able to distinguish differences across severity groups and improvement over 16 weeks of standard therapy. The use of the Acne-QoL should aid physicians in understanding the impact of facial acne on young adults, and may be useful in assessing therapeutic effects in acne clinical trials.

Readiness of critical care physicians and nurses to handle requests for organ donation

BACKGROUND: Critical care nurses and physicians usually care for those patients whose condition progresses to brain death and are also often responsible for requesting organ donation from the family of a brain-dead patient. We hypothesized that staff support, knowledge, and training levels would be significantly associated with organ donation rates. OBJECTIVE: To assess the readiness of critical care staff to successfully handle requests for organ donation. METHODS: A total of 1061 critical care staff from 28 hospitals in four separate regions of the United States completed a questionnaire that assessed (1) factual knowledge about organ donation, (2) understanding of brain death, (3) previous training in procedures for requesting donations, and (4) comfort levels with the donation process. RESULTS: Staff training in effective procedures for requesting organ donations was significantly correlated with hospitals' donation rates. Less than a third of respondents, however, had received training in explaining brain death to and requesting organ donation from a grieving family. In hospitals with high rates of organ donation, 52.9% of staff had received training; in hospitals with low rates of organ donation, 23.5% of staff had received training. Levels of factual knowledge about organ donation and brain death were unexpectedly low but were not significantly related to hospitals' rates of organ donation. CONCLUSIONS: Training of critical care nurses and physicians in effective procedures for requesting organ donation is significantly associated with higher rates of organ donation, yet two thirds of critical care staff report no relevant training. Consequently, critical care staff cannot be considered ready to effectively handle requests for organ donation.

The sites of action of the two copy number control functions of plasmid R1

Two negatively acting functions - the CopA-RNA and the CopB protein - are involved in the control of replication of plasmid R1. They both act as inhibitors of expression of a gene, repA, which seems to be positively required for autonomous plasmid replication. Here we show that the two control functions act separately and independently. The CopB protein represses initiation of transcription of the repA gene, and its target site lies within a 60 base pair region containing the repA promoter. The CopA-RNA acts downstream of the repA promoter in the leader sequence containing the copA gene itself, preceding the repA structural gene. Measurements of RepA-beta-galactosidase expression from wild-type and a copA mutant fusion hybrid in the presence of extra copies of the respective copA genes show that a point mutation affecting the activity of the CopA-RNA can also affect CopA target properties. It is therefore concluded that the target site for the CopA-RNA resides within the copA gene in a small region encoding the loop of a stem-loop structure in the CopA-RNA. In addition, the data indicate a direct nucleic acid-nucleic acid interaction as the basis for the CopA inhibitor activity.

Androgen metabolism in sebaceous glands from subjects with and without acne

OBJECTIVE

To determine if there are differences in the activity of 17beta-hydroxysteroid dehydrogenase and 5alpha-reductase (responsible for the production of testosterone and dihydrotestosterone, respectively) in sebaceous glands obtained from men and women with and without acne.

DESIGN

Single-center examination of androgen levels and sebaceous gland enzyme activity in a cohort of volunteers.

SETTING

Academic referral center.

PATIENTS

Thirty-four subjects, consisting of 8 women with acne, 10 women without acne, 8 men with acne, and 8 men without acne.

INTERVENTIONS

Single visit for blood sampling and 2 biopsies of forehead skin.

MAIN OUTCOME MEASURES

Serum levels of androgens were determined and compared with the activity of 5alpha-reductase and 17beta-hydroxysteroid dehydrogenase in sebaceous glands microdissected from skin samples.

RESULTS

No significant differences in the activity of 5alpha-reductase or 17beta-hydroxysteroid dehydrogenase in sebaceous glands according to the presence of acne were noted in either men or women. The activity of 5alpha-reductase and 17beta-hydroxysteroid dehydrogenase was significantly greater in sebaceous glands from men (n = 16) than women (n = 17). The oxidative activity of 17beta-hydroxysteroid dehydrogenase was 2-fold higher in men than women. Serum levels of dehydroepiandrosterone sulfate, androstenedione, testosterone, and dihydrotestosterone were significantly higher in women with acne than in women without acne. No differences in serum androgen levels were noted in men on the basis of the presence of acne.

CONCLUSIONS

Higher serum androgen levels are associated with the presence of acne in women. A role for locally produced androgens in this process, however, cannot be excluded.

Isolation and characterization of new copy mutants of plasmid R1, and identification of a polypeptide involved in copy number control

Site-specific deletions and insertions in the replication region of plasmid R1 have generated a new class of copy mutants that are present in the cell with 10-15-fold increased copy number. All mutations described inactivate a copy number control gene which is distinct from another cop inc gene that was identified previously (Molin and Nordström 1980). Insertion of the lac operon lacking the normal lac promoter has been used to determine the direction of transcription of this cop gene. The mutants may all be complemented by wild-type plasmid derivatives and are thus recessive. In incompatibility tests with wild-type R1 plasmids, these mutants are indistinguishable from the wild-type plasmid. It therefore seems that this cop function does not play an important role for the incompatibility function. A polypeptide, molecular weight 11,000, has been identified as being the product of this cop gene.

Mutation analysis of the Pip interaction domain reveals critical residues for protein-protein interactions

The PU.1 interaction partner (Pip) is a member of the interferon regulatory factor family that regulates gene expression through heterodimerization with the ETS transcription factor PU.1. Binding of Pip alone to DNA is weak, and usually it is recruited by phosphorylated PU.1 to form a strong ternary complex with specific DNA sequences. An approach combining sequence homology analysis, secondary structure predictions, and a precise mutational strategy has been used to determine critical residues within the Pip heterodimerization domain that contribute to ternary complex formation. We have delimited the Pip interaction domain to residues 245-422 by using deletion analysis. Site-directed mutagenesis of conserved polar amino acids within two predicted alpha-helices contained in this region, and which are highly conserved in the IRF family, confirmed the importance of these residues for Pip-PU.1 interaction with DNA as well as for trans-activation activity. Our results suggest the existence of a functional epitope essential for heterodimerization between Pip and PU.1 and possibly, in general, between interferon regulatory factor family members and their partners.

Convergent transcription interferes with expression of the copy number control gene, copA , from plasmid R1

The copy number control gene, copA, of plasmid R1 codes for an 80-nucleotide untranslatable RNA. In Escherichia coli minicells, some copA hybrid plasmids and R1 miniplasmids also express a transcript of 200 nucleotides. Only the small RNA mediates the CopA phenotype. The switch between 80- and 200-nucleotide RNA synthesis is shown to be caused by convergent transcription; if transcription proceeds in both directions the inactive larger RNA is synthesised; the active small RNA is formed when copA transcription is not opposed by transcription from the other direction. The data presented indicate that convergent transcription interferes with copA expression by abolishing or reducing normal copA transcription termination.

Plasmodium falciparum: ingested anti-sporozoite antibodies affect sporogony in Anopheles stephensi mosquitoes

In endemic areas, malaria-infected mosquitoes may feed upon humans who possess antibodies against malaria sporozoites. Therefore, we examined the effect that ingested anti-sporozoite antibodies have upon Plasmodium falciparum sporogony within Anopheles stephensi mosquitoes. Anti-sporozoite antibodies (IgG) traversed the midgut into the hemocoel within 3 hr following ingestion and, depending upon the titer, persisted for 6-24 hr. When fed to infected A. stephensi at 12 days postinfection (p.i.), anti-sporozoite antibodies bound to sporozoites in the hemocoel, but not to sporozoites residing in the salivary glands of the same mosquitoes. Anti-sporozoite antibodies also bound to developing oocysts when fed to infected A. stephensi at 5 days p.i. Oocysts in mosquitoes that had been fed anti-sporozoite antibodies on Day 5 p.i. produced significantly more sporozoites than did oocysts in nonimmune-fed (Day 5 p.i.) mosquitoes. In addition, the sporozoites from Day 5 immune-fed mosquitoes were significantly more infective to cultured human hepatoma cells than were sporozoites from nonimmune-fed controls. Use of hetereologous immune feedings at Day 5 p.i. did not result in an enhanced production of sporozoites, suggesting that enhancement is related to the specificity of the antibody and is not merely a nutritional effect.

Invasive filamentous fungal infections associated with renal transplant tourism

'Transplant tourism,' the practice of traveling abroad to acquire an organ, has emerged as an issue in kidney transplantation. We treated a patient who developed invasive aspergillosis of the allograft vascular anastomosis after receiving a kidney transplant in Pakistan, prompting us to review the literature of invasive mycoses among commercial organ transplant recipients. We reviewed all published cases of infections in solid organ transplant recipients who bought their organs abroad and analyzed these reports for invasive fungal infections. Including the new case reported here, 19 cases of invasive fungal infections post commercial kidney transplant occurring in 17 patients were analyzed. Infecting organisms were Aspergillus species (12/19; 63%), Zygomycetes (5/19; 26%), and other fungi (2/19; 5%). Invasive mold infections were present at the transplanted graft in 6/17 patients (35%) with graft loss or death in 13/17 (76%) of patients and overall mortality (10/17) 59%. Invasive fungal infections, frequently originating at the graft site, have emerged as a devastating complication of commercial renal transplant and are associated with high rates of graft loss and death.

Expression of a copy number control gene (copB) of plasmid R1 is constitutive and growth rate dependent

The copy number control gene copB from plasmid R1 was fused to the lacZ gene in vitro, resulting in expression of a fused polypeptide consisting of the first 53 amino acids of the CopB polypeptide and the beta-galactosidase polypeptide minus its first 8 amino acids. Based on measurements of specific activities of this fused protein under various conditions, it was concluded that expression of copB is gene dosage dependent, unregulated by plasmid-coded functions, and proportional to growth rate between 0.4 and 2.0 doublings per h. The rate of expression of the copB gene is surprisingly high compared with other known cases of regulatory proteins.

Immunolocalization of 5alpha-reductase isozymes in acne lesions and normal skin

BACKGROUND

Dihydrotestosterone mediates androgen-dependent diseases, such as acne, hirsutism, and androgenetic alopecia. This hormone is produced from testosterone by the 5alpha-reductase enzyme. There are 2 isozymes of 5alpha-reductase (types 1 and 2) that differ in their localization within the body and even within the skin. Activity of the type 1 isozyme predominates in sebaceous glands, where it may be involved in regulation of sebum production. Since specific inhibition of 5alpha-reductase type 1 may represent a novel therapeutic approach to acne, it is important to define the localization of these isozymes in normal sebaceous follicles and acne lesions.

OBSERVATIONS

Skin biopsy specimens were obtained from the backs of 11 subjects: 8 with acne and 3 without acne. Sections of normal follicles, open comedones, closed comedones, and inflammatory lesions were incubated with antibodies to types 1 and 2 5alpha-reductase. In all samples, the type 1 antibody localized specifically to sebaceous glands, and the type 2 antibody localized to the companion layer of the hair follicle (the innermost layer of the outer root sheath) and granular layer of the epidermis. Localization of the type 2 isozyme was also noted within the walls of open and closed comedones and in endothelial cells from sections of inflammatory lesions.

CONCLUSIONS

The immunolocalization of 5alpha-reductase isozymes in normal sebaceous follicles and acne follicles is similar to the pattern described in terminal hair follicles and corresponds with the findings of biochemical studies that have demonstrated predominance of type 1 activity in sebaceous glands. The function of type 2 5alpha-reductase in comedones or endothelial cells in inflammatory lesions is unknown.

Is laparoscopic donor nephrectomy here to stay?

BACKGROUND

Open live donor nephrectomy is safe and provides kidneys of excellent quality. The complexity of the laparoscopic donor technique has raised considerable concerns.

METHOD

Twenty-six laparoscopic live donor nephrectomies were done from October 1997 to October 1998.

RESULTS

All kidneys had immediate function. All recipients except 1 had serum creatinines less than 2.0 mg at 2 months posttransplantation. Three complications (wound infection, neuroma, reoperation) occurred. There was no mortality.

CONCLUSIONS

Proper surgical training and patient selection can result in a safe donor operation that provides kidneys of excellent quality.

Random mutagenesis of staphylococcal nuclease and phage display selection

Multiple cycles of mutagenesis and phage display selection have been investigated as a method for obtaining enzymes with altered catalytic properties. A library of staphylococcal nuclease mutants displayed on phage was created by error-prone PCR mutagenesis and selected for binding to thymidine- or guanosine-containing substrate analogs. After discarding non-binders, the binding mutants were then subjected to further mutagenesis and selection rounds. After four mutagenesis and selection cycles, the catalytic properties of some of the resulting nucleases were studied and one nuclease with nine accumulated mutations was found to have a two-fold reduction in kcat for DNA hydrolysis, but a two-fold increase in kcat/Km for hydrolysis of a thymidine containing small molecule substrate. The possibility of this technique for in vitro evolution of enzyme properties is discussed.

Backbone dynamics of a short PU.1 ETS domain

The resonance assignments, secondary structure and backbone dynamics of the ETS domain of the transcription factor PU.1 have been determined for the free protein in solution by NMR spectroscopy. The secondary structure for the free ETS domain is similar to that observed in the crystal structure of the PU.1 protein complexed with DNA, except that helix alpha2 and recognition helix alpha3 are shorter for the free protein in solution. Backbone dynamics of the protein have been examined using amide hydrogen-deuterium exchange and (15)N laboratory-frame spin relaxation measurements. A significant probability of local unfolding of helix alpha2, which precedes the loop-helix-loop DNA recognition domain, is inferred from the very fast hydrogen-deuterium exchange for amide protons in this helix. The (15)N relaxation measurements indicate that the protein is partially oligomerized at a concentration of 2.5 mM, but monomeric at a concentration of 0.3 mM. The (15)N relaxation data for the low concentration sample were interpreted, using the model-free formalism, to provide insight into protein dynamics on picosecond-nanosecond and microsecond-millisecond time scales. High flexibility of the protein backbone is observed for the residues in the loop between alpha2 and alpha3. This loop is variable in length and in structure within the class of winged helix proteins and is partially responsible for binding to DNA. The dynamic properties observed for alpha2, alpha3 and the intervening loop may indicate a correlation between protein plasticity in particular structural elements and recognition of specific DNA sequences.

Quality of life in the first 100 days after suspected acute myocardial infarction--a suitable trial endpoint?

STUDY OBJECTIVE

The aim was to determine the loss of quality of life following admission to hospital with suspected myocardial infarction.

DESIGN

The study involved a cohort of admissions, with interview and follow up for 100 days. Main outcome measures were the quality of life prior to admission and at each stage of convalescence, estimated using the Rosser-Kind matrix: the calculated number of quality adjusted days during a 100 d follow up period.

SETTING

The study took place in a teaching hospital in Scotland.

PATIENTS

206 patients were admitted with suspected acute myocardial infarction. Infarction was confirmed in 160 (Q wave infarcts 100, non-Q-wave infarcts 60), and unconfirmed in 46.

MAIN RESULTS

The quality of life scores before the suspected heart attack were similar for patients whose final diagnosis was Q wave infarction, non-Q-wave infarction, or non-infarction. Of the 160 patients with confirmed infarction, only 54 (34%) had regained their previous quality of life scores at the end of 100 days, compared with 26 of 46 (57%) patients with unconfirmed infarction (p < 0.01). The mean numbers of quality adjusted days lost to patients with Q wave infarction, non-Q-wave infarction, and non-infarction were 17.0, 12.4, and 5.9 respectively (infarction v non-infarction, p < 0.0001). Measurements of both quantity and quality of life contributed to these results.

CONCLUSIONS

The number of quality adjusted days lost after acute myocardial infarction is a practicable measurement that is relevant to patients' lives. It might be suitable as an outcome measure for clinical trials of thrombolytic therapy.

Expression cloning of cDNA by phage display selection

Expression cloning of a mouse kappa chain fragment has been achieved from a cDNA library by display of expressed proteins on filamentous phage and affinity selection for binding to anti-mouse Fab antibodies. Expressed proteins were anchored to the phage coat by a synthetic, anti-parallel leucine zipper, which had been selected from a semi-randomized zipper library for the ability to connect a test protein to phage. From a library of 4 x 10(6) transformants, two separate clones displaying different size cDNA inserts were recovered after four selection rounds. These results further demonstrate the utility of phage display for cDNA expression cloning.

Identification and characterization of mutations responsible for a runaway replication phenotype of plasmid R1

Initiation of replication of the resistance plasmid R1 is carefully regulated by the two negatively acting factors, CopA and CopB. It is shown here that the temperature-dependent runaway-replication phenotype of an R1 plasmid mutant is caused by two point mutations in each of the promoters for the genes of these control factors. Expression of the two genes is affected in the following way: (1) one C-to-T transition in the putative -35 box of the copB-repA operon creates a two- to three-fold stronger promoter from which expression is temperature-dependent; (2) another C-to-T transition in a G + C-rich area immediately downstream from the -10 box of the copA promoter reduces expression of the copA gene three-fold. The phenotypic consequences of the two mutations are discussed in the light of the current model for R1 replication control.