[Urogenital tumors following kidney transplantation-monocentric analysis of incidences and overview of urological preventive measures]. / Urogenitale Tumoren nach Nierentransplantation ­ monozentrische Aufarbeitung der Inzidenzen und Überblick urologischer Vorsorgemaßnahmen.

BACKGROUND: Urogenital tumors are among the most common solid malignancies after kidney transplantation (TX). OBJECTIVE: We analyzed the incidence and mortality of urogenital tumors after kidney TX in our own patient population as well as answered the question of recommended follow-up necessity and frequency in this cohort. MATERIALS AND METHODS: Retrospective monocentric data collection of tumor diseases and the most common urogenital tumors after kidney TX at the Transplant Center Dresden between 2010 and 2020 was done. From this, we derived recommendations for a useful follow-up concept. RESULTS: A total of 13% (93/710) of kidney TX patients developed a neoplasm. Older patients (60.1 ± 10.6 vs. 53.8 ± 12.5; p < 0.001), with higher Charlson scores (≥ 4: 68% vs. 46%; p < 0.001) and a previous tumor history (18% vs. 8%; p < 0.001) were more likely to develop a neoplasm after transplantation. In the multivariate analysis, previous tumor history was found to be an independent predictor of tumor development after renal transplantation (OR 2.2; 95%-KI [1.2-4.1]; p = 0.01). Urogenital tumors accounted for 30% (28/93) of all malignancies. Renal cell carcinoma of the native kidney was the most common (n = 12) neoplasm, followed by prostate cancer (n = 9). CONCLUSION: Most solid malignancies after kidney TX arise from the urinary tract. Due to their frequency, there is an urgent need for specialized urological therapy and long-term follow-up care. Even before listing for TX, risk factors can be recognized and individual concepts for follow-up care can be developed.

[Organ donation in Germany under the new legislation]. / Organspende in Deutschland im Zeichen der neuen Gesetzgebung.

The political debate concerning organ donations reached increased public awareness from 2012, despite the multiple scandals around organ allocation. The process of organ donation has been restructured since financing improved by the GZSO (Gesetz für bessere Zusammenarbeit und bessere Strukturen bei der Organspende). The focus should be reduction of deficits in donor identification and notification within hospitals. Hence, it is time to introduce an "opt-out" solution, a system already standard in other European countries. Finally, to increase in the much-needed organ donations within Germany a multistructured concept should be established: improving hospital pathways, staff recognition, public awareness and political support.

Identity elements for specific aminoacylation of yeast tRNA(Asp) by cognate aspartyl-tRNA synthetase.

The nucleotides crucial for the specific aminoacylation of yeast tRNA(Asp) by its cognate synthetase have been identified. Steady-state aminoacylation kinetics of unmodified tRNA transcripts indicate that G34, U35, C36, and G73 are important determinants of tRNA(Asp) identity. Mutations at these positions result in a large decrease (19- to 530-fold) of the kinetic specificity constant (ratio of the catalytic rate constant kcat and the Michaelis constant Km) for aspartylation relative to wild-type tRNA(Asp). Mutation to G10-C25 within the D-stem reduced kcat/Km eightfold. This fifth mutation probably indirectly affects the presentation of the highly conserved G10 nucleotide to the synthetase. A yeast tRNA(Phe) was converted into an efficient substrate for aspartyl-tRNA synthetase through introduction of the five identity elements. The identity nucleotides are located in regions of tight interaction between tRNA and synthetase as shown in the crystal structure of the complex and suggest sites of base-specific contacts.

The Early Psychosis Screener (EPS): Item development and qualitative validation.

A panel of experts assembled and analyzed a comprehensive item bank from which a highly sensitive and specific early psychosis screener could be developed. Twenty well-established assessments relating to the prodromal stage, early psychosis, and psychosis were identified. Using DSM-5 criteria, we identified the core concepts represented by each of the items in each of the assessments. These granular core concepts were converted into a uniform set of 490 self-report items using a Likert scale and a 'past 30days' time frame. Partial redundancy was allowed to assure adequate concept coverage. A panel of experts and TeleSage staff rated these items and eliminated 189 items, resulting in 301 items. The items were subjected to five rounds of cognitive interviewing with 16 individuals at clinically high risk for psychosis and 26 community mental health center patients. After each round, the expert panel iteratively reviewed, rated, revised, added, or deleted items to maximize clarity and centrality to the concept. As a result of the interviews, 36 items were revised, 52 items were added, and 205 items were deleted. By the last round of cognitive interviewing, all of the items were clearly understood by all participants. In future work, responses to the final set of 148 items and machine learning techniques will be used to quantitatively identify the subset of items that will best predict clinical high-risk status and conversion.

Manipulation of tRNA properties by structure-based and combinatorial in vitro approaches.

The wide knowledge accumulated over the years on the structure and function of transfer RNAs (tRNAs) has allowed molecular biologists to decipher the rules underlying the function and the architecture of these molecules. These rules will be discussed and the implications for manipulating tRNA properties by structure-based and combinatorial in vitro approaches reviewed. Since most of the signals conferring function to tRNAs are located on the two distal extremities of their three-dimensional L shape, this implies that the structure of the RNA domain connecting these two extremities can be of different architecture and/or can be modified without disturbing individual functions. This concept is first supported by the existence in nature of RNAs of peculiar structures having tRNA properties, as well as by engineering experiments on natural tRNAs. The concept is further illustrated by examples of RNAs designed by combinatorial methods. The different procedures used to select RNAs or tRNA-mimics interacting with aminoacyl-tRNA synthetases or with elongation factors and to select tRNA-mimics aminoacylated by synthetases are presented, as well as the functional and structural characteristics of the selected molecules. Production and characteristics of aptameric RNAs fulfilling aminoacyl-tRNA synthetase functions and of RNAs selected to have affinities for amino acids are also described. Finally, properties of RNAs obtained by either the structure-based or the combinatorial methods are discussed in the light of the origin and evolution of the translation machinery, but also with a view to obtain new inhibitors targeting specific steps in translation.

[Management of urological complications after renal transplantation]. / Behandlung urologischer Komplikationen nach Nierentransplantation.

Urological complications after kidney transplantation can cause a major reduction in renal function. Surgical complications like urinary leakage and ureteral obstruction need to be solved by a specialist in the field of endourological procedures and open surgical interventions. The article summarizes this and other common urological problems after kidney transplantation.

Comparative evaluation of the Bio-Rad Geenius HIV-1/2 Confirmatory Assay and the Bio-Rad Multispot HIV-1/2 Rapid Test as an alternative differentiation assay for CLSI M53 algorithm-I.

INTRODUCTION: The CLSI-M53-A, Criteria for Laboratory Testing and Diagnosis of Human Immunodeficiency Virus (HIV) Infection; Approved Guideline includes an algorithm in which samples that are reactive on a 4th generation EIA screen proceed to a supplemental assay that is able to confirm and differentiate between antibodies to HIV-1 and HIV-2. The recently CE-marked Bio-Rad Geenius HIV-1/2 Confirmatory Assay was evaluated as an alternative to the FDA-approved Bio-Rad Multispot HIV-1/HIV-2 Rapid Test which has been previously validated for use in this new algorithm. METHODS: This study used reference samples submitted to the Canadian - NLHRS and samples from commercial sources. Data was tabulated in 2×2 tables for statistical analysis; sensitivity, specificity, predictive values, kappa and likelihood ratios. RESULTS: The overall performance of the Geenius and Multispot was very high; sensitivity (100%, 100%), specificity (96.3%, 99.1%), positive (45.3, 181) and negative (0, 0) likelihood ratios respectively, high kappa (0.96) and low bias index (0.0068). The ability to differentiate HIV-1 (99.2%, 100%) and HIV-2 (98.1%, 98.1%) Ab was also very high. CONCLUSION: The Bio-Rad Geenius HIV-1/2 Confirmatory Assay is a suitable alternative to the validated Multispot for use in the second stage of CLSI M53 algorithm-I. The Geenius has additional features including traceability and sample and cassette barcoding that improve the quality management/assurance of HIV testing. It is anticipated that the CLSI M53 guideline and assays such as the Geenius will reduce the number of indeterminate test results previously associated with the HIV-1 WB and improve the ability to differentiate HIV-2 infections.

[Functional results after reconstruction of severed flexor tendons by means of free flexor tendon grafts]. / Funktionsergebnisse nach Wiederherstellung verletzter Beugesehnen durch freie Beugesehnenplastik.

From 93 free flexor tendon grafts which have been performed in the years 1959--1976 because of flexor tendon laceration 85% could be reinvestigated after 6 years 10 months (average intervall). Three reinvestigation schemes for classification of the functional results were used (VERDAN/MICHON 1961, McKENZIE 1967, BUCK-GRAMCKO 1976). This had the advantage that marked differences in the classification schemes could be demonstrated. With 56% of very good and 22% of good results according to the classification of McKENZIE or 30% of very good and 26% of good results according to the classification of BUCK-GRAMCKO the results of free flexor tendon graft in the area of the thumb are significantly better than those in the fingers. In addition the relationship between the objective reinvestigation results of the operation and the subjective results appraised by the patients is demonstrated and shows that BUCK-GRAMCKO's classification comes closest to the patients evaluation.

Influence of tRNA tertiary structure and stability on aminoacylation by yeast aspartyl-tRNA synthetase.

Mutations have been designed that disrupt the tertiary structure of yeast tRNA(Asp). The effects of these mutations on both tRNA structure and specific aspartylation by yeast aspartyl-tRNA synthetase were assayed. Mutations that disrupt tertiary interactions involving the D-stem or D-loop result in destabilization of the base-pairing in the D-stem, as monitored by nuclease digestion and chemical modification studies. These mutations also decrease the specificity constant (kcat/Km) for aspartylation by aspartyl-tRNA synthetase up to 10(3)-10(4) fold. The size of the T-loop also influences tRNA(Asp) structure and function; change of its T-loop to a tetraloop (-UUCG-) sequence results in a denatured D-stem and an almost 10(4) fold decrease of kcat/Km for aspartylation. The negative effects of these mutations on aspartylation activity are significantly alleviated by additional mutations that stabilize the D-stem. These results indicate that a critical role of tertiary structure in tRNA(Asp) for aspartylation is the maintenance of a base-paired D-stem.

Additive, cooperative and anti-cooperative effects between identity nucleotides of a tRNA.

We have investigated the functional relationship between nucleotides in yeast tRNAAsp that are important for aspartylation by yeast aspartyl-tRNA synthetase. Transcripts of tRNAAsp with two or more mutations at identity positions G73, G34, U35, C36 and base pair G10-U25 have been prepared and the steady-state kinetics of their aspartylation were measured. Multiple mutations affect the catalytic activities of the synthetase mainly at the level of the catalytic constant, kcat. Kinetic data were expressed as free energy variation at transition state of these multiple mutants and comparison of experimental values with those calculated from results on single mutants defined three types of relationships between the identity nucleotides of this tRNA. Nucleotides located far apart in the three-dimensional structure of the tRNA act cooperatively whereas nucleotides of the anticodon triplet act either additively or anti-cooperatively. These results are related to the specific interactions of functional groups on identity nucleotides with amino acids in the protein as revealed by the crystal structure of the tRNAAsp/aspartyl-tRNA synthetase complex. These relationships between identity nucleotides may play an important role in the biological function of tRNAs.

The spectrum of topography found in keratoconus.

In order to more completely understand the topographic changes associated with keratoconus we performed computer-analyzed, digitized, videokeratoscopy (CADVK) on 23 patients with clinically documented keratoconus, using the EH-270 Corneal Topographer (Visioptic, Houston, TX). The majority of analyzed eyes demonstrated the classic picture of a well defined zone of inferior to inferotemporal steepening. However, several other topographic patterns were noted, including: nasal, superior, and central steepening, as well as extension of the inferior steepening superiorly. Additionally, significant flattening was found in some portions of the cornea away from the cone, particularly in the superonasal quadrant. In all cases, the precise location and degree of steepening could be easily defined. Interestingly, for both typical and atypical topographic patterns, marked symmetry between eyes in each patient was noted. The use of CADVK may allow for a more thorough appreciation of the diverse and complex topographic abnormalities associated with keratoconus, information which could aid in contact lens management and design.

Contact lens failure in keratoconus management.

PURPOSE: Surgery is indicated for keratoconus when management with contact lenses fails. The authors sought to determine the relative contribution of various preoperative patient and ocular factors to the ultimate causes of contact lens failure. METHODS: The records of unoperated eyes of keratoconus patients whose contact lenses were managed intensively before undergoing penetrating keratoplasty (PK) at the authors' institution between 1981 and 1990 were selected for study. Univariate and multivariate analyses were performed to identify risk factors for early contact lens failure. RESULTS: The records of 99 keratoconic eyes of 75 patients with an average age of 34 years and average keratometry readings of 57.5 diopters at presentation were studied. Cases had been followed for an average of 27 months before PK. The primary reasons for PK were a best-corrected visual acuity of under 20/40 (despite good contact lens fit) causing disability for the patient (43%), contact lens intolerance (32%), frequent lens displacement (13%), and significant peripheral thinning of the cornea (12%). The referral source of the patient, sex, a history of PK in the fellow eye, or of contact lens wear in either eye did not alter the relative contributions of these parameters to surgery. CONCLUSION: Poor best-corrected visual acuity at presentation, higher keratometry readings (greater than or equal to 55 D), age (greater than or equal to 40 years), and duration of disease (greater than 5 years) were significantly associated with failure due to poor functional acuity and peripheral thinning, frequently leading to surgery within the first 12 months after presentation.

Human mitochondrial tRNAs in health and disease.

The human mitochondrial genome encodes 13 proteins, all subunits of the respiratory chain complexes and thus involved in energy metabolism. These genes are translated by 22 transfer RNAs (tRNAs), also encoded by the mitochondrial genome, which form the minimal set required for reading all codons. Human mitochondrial tRNAs gained interest with the rapid discovery of correlations between point mutations in their genes and various neuromuscular and neurodegenerative disorders. In this review, emerging fundamental knowledge on the structure/function relationships of these particular tRNAs and an overview of the large variety of mechanisms within translation, affected by mutations, are summarized. Also, initial results on wide-ranging molecular consequences of mutations outside the frame of mitochondrial translation are highlighted. While knowledge of mitochondrial tRNAs in both health and disease increases, deciphering the intricate network of events leading different genotypes to the variety of phenotypes requires further investigation using adapted model systems.