Measurement instruments for the core outcome set of congenital melanocytic naevi and an assessment of the measurement properties according to COSMIN: a systematic review.

Background: Congenital melanocytic naevi (CMN) can impact on patients' lives due to their appearance and the risk they carry of neurological complications or melanoma development. The development of a core outcome set (COS) will allow standardised reporting and enable comparison of outcomes. This will help to improve guidelines. In previous research, relevant stakeholders reached a consensus over which core outcomes should be measured in any future care or research. The next step of the COS development is to select the appropriate measurement instruments. Aim: Step 1: to update a systematic review identifying all core outcomes and measurement instruments available for CMN. Step 2: to evaluate the measurement properties of the instruments for the core outcomes. Methods: This study was registered in PROSPERO and performed according to the PRISMA checklist. Step 1 includes a literature search in EMBASE (Ovid), PubMed and the Cochrane Library to identify core outcomes and instruments previously used in research of CMN. Step 2 yields a systematic search for studies on the measurement properties of instruments that were either developed or validated for CMN, including a methodological quality assessment following the COSMIN methodology. Results: Step 1 included twenty-nine studies. Step 2 yielded two studies, investigating two quality of life measurement instruments. Conclusion: Step 1 provided an overview of outcomes and instruments used for CMN. Step 2 showed that additional research on measurement properties is needed to evaluate which instruments can be used for the COS of CMN. This study informs the instrument selection and/or development of new instruments.

Transcriptional organization of the erythromycin biosynthetic gene cluster of Saccharopolyspora erythraea.

The transcriptional organization of the erythromycin biosynthetic gene (ery) cluster of Saccharopolyspora erythraea has been examined by a variety of methods, including S1 nuclease protection assays, Northern blotting, Western blotting, and bioconversion analysis of erythromycin intermediates. The analysis was facilitated by the construction of novel mutants containing a S. erythraea transcriptional terminator within the eryAI, eryAIII, eryBIII, eryBIV, eryBV, eryBVI, eryCIV, and eryCVI genes and additionally by an eryAI -10 promoter mutant. All mutant strains demonstrated polar effects on the transcription of downstream ery biosynthetic genes. Our results demonstrate that the ery gene cluster contains four major polycistronic transcriptional units, the largest one extending approximately 35 kb from eryAI to eryG. Two overlapping polycistronic transcripts extending from eryBIV to eryBVII were identified. In addition, seven ery cluster promoter transcription start sites, one each beginning at eryAI, eryBI, eryBIII, eryBVI, and eryK and two beginning at eryBIV, were determined.

Sonication-dependent electroporation of the erythromycin-producing bacterium Saccharopolyspora erythraea.

We report the development of an electrotransformation method applicable to all strains of Saccharopolyspora erythraea examined to date. Vegetatively grown mycelia were rendered electrocompetent by subjecting mycelial suspensions to ultrasound pulses. The protocol provides an alternative route for the introduction of DNA into filamentous microorganisms otherwise recalcitrant to transformation techniques.

The importance of local data bases in medical expert systems: TICITL.

The database of our medical expert system, TICITL, contains the records of more than 15,000 gastroenterological patients. The data was collected over fifteen years (1977-1992) during which the patients were followed for at least three months to establish a final diagnosis. Using a new set of 230 gastroenterological cases, TICITL's first diagnosis was similar to the final diagnosis in 90% of the patients. When compared to foreign medical expert systems (M.E.S.), there is a considerable difference in diagnostic accuracy favorable to the local system. Another local program is also as accurate as TICITL. Consequently, we attribute these results to the database and strongly recommend employing real local patients whenever possible to implement M.E.S. in a new geographical area.

The major capsid protein of the lipid-containing bacteriophage PR4 is the precursor of two other capsid proteins.

We report that capsid proteins P16 and P18 of bacteriophage PR4 are synthesized by post-translational processing of a portion of the major capsid protein, P2. A polyclonal antibody raised against purified P2 reacted with P16 and P18 as well as with P2. A monoclonal antibody reacted with both P2 and P18. The amino acid sequences of the N-termini of P2 and P18 exactly matched, indicating that P18 is derived from the N-terminal segment of P2. These data were confirmed by the analysis of the proteins encoded by various nonsense and missense P2 mutants. The 3129-bp MnlI-C fragment of the PR4 genome was shown to encode P2. The nucleotide sequence of this fragment was obtained and a single continuous ORF was found to encode P2, thus excluding introns and transcript processing in the production of P16 and P18. The DNA segment contained eight ORFs sized > 200 bp and the genes encoding proteins P6 and P6A as well as P2 were mapped by marker rescue analysis. We also report the isolation and characterization of a new class of P2 missense mutants.

Synaptic reorganization in the feline ventral anterior thalamic nucleus induced by lesions in the basal ganglia.

This report presents the results of quantitative analysis of synaptic coverage of the dendrites of thalamocortical projection neurons in the adult cat ventral anterior thalamic nucleus (VA) and its changes at short (4 days)- and long-term (1 year) survival times after combined unilateral kainic acid lesions in the substantia nigra pars reticularis and entopeduncular nucleus. The study showed that deafferentation induced an increase in the appositional length of the dendrites of GABAergic local circuit neurons along projection neuron dendrites, accompanied by an increase in the number of dendrodendritic synapses. Dendritic or axonic origin of other unusual presynaptic structures at 1 year postlesion could not be established with certainty. All of them displayed some features of growth cones, such as an abundance of tubular and vesicular structures many with electron-dense contents. Projection neuron dendrites postsynaptic to these profiles contained numerous coated vesicles at the same survival time. The findings suggest that (i) the lesioning of the two basal ganglia output structures induces synaptic reorganization in the VA, (ii) this process appears to be active at 1 year after deafferentation, and (iii) all reactive systems display symmetric contacts and positive GAD immunoreactivity suggesting that homotypic remodeling is taking place. Despite the signs of remodeling, the density of presynaptic terminals with symmetric contacts on primary and secondary projection neuron dendrites in the VA remained below the control level at 1 year postlesion suggesting that an imbalance of excitatory and inhibitory inputs on thalamocortical projection neurons may persist for long periods after deafferentation.

Lipoic acid metabolism in Escherichia coli: isolation of null mutants defective in lipoic acid biosynthesis, molecular cloning and characterization of the E. coli lip locus, and identification of the lipoylated protein of the glycine cleavage system.

We report the isolation and genetic characterization of novel Tn10dTc and Tn1000dKn insertion mutations in and near the lip locus of the Escherichia coli chromosome. The Tn10dTc and Tn1000dKn mutations define two genes, lipA and lipB, involved in lipoic acid biosynthesis. Two representative alleles (lip-2 and lip-9) from the previously reported genetic class of lipoic acid auxotrophic mutants (A. A. Herbert and J. R. Guest, J. Gen. Microbiol. 53:363-381, 1968) were assigned to the lipA complementation group. We have cloned the E. coli lip locus and developed a recombinant plasmid-based genetic system for fine-structure physical-genetic mapping of mutations in this region of the E. coli chromosome. We also report that a recombinant plasmid containing a 5.2-kbp PvuII restriction fragment from the E. coli lip locus produced three proteins of approximately 8, 12, and 36 kDa by using either a maxicell or in vitro transcription translation expression system. The 36-kDa protein was identified as the gene product encoded by the lipA locus. Finally, we have identified a previously unreported lipoylated protein that functions in the glycine cleavage system of E. coli.

Nonsense mutants defining seven new genes of the lipid-containing bacteriophage PR4.

Thirty-eight new nonsense mutants of the lipid-containing bacteriophage PR4 were isolated. These mutants define seven new viral genes, including the gene encoding the terminal genome protein and an accessory lytic factor. The defective gene products produced in uv-irradiated cells infected with representative mutants from each of the new genetic groups were identified using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Extracts of uv-irradiated cells infected with nonsense mutants that produce a defective major capsid protein, P2, also lacked two lower molecular weight proteins. The synthesis of all three protein species was recovered in cells infected with one-step revertants of two independent major capsid protein mutants, suggesting the possibility of post-translational processing or overlapping genes. The time course of protein synthesis in wild-type PR4-infected cells was examined using SDS-PAGE. These analyses revealed at least 34 proteins produced following phage PR4 infection that were not present in uninfected control cultures.

A physical-genetic map of the lipid-containing bacteriophage PR4.

A physical map of the bacteriophage PR4 genome was constructed which includes 59 sites for 10 restriction endonucleases. The average size of the phage PR4 genome estimated from the sum of DNA fragments generated with the restriction endonucleases Hphl, Mnll, Bgll, AlwNl, and BstXl is 15,170 +/- 240 bp. A collection of recombinant plasmids containing restriction fragments of PR4 DNA generated with Bgll, Hphl, Mnll, and Xmnl inserted into either the low copy number plasmid vector pHSG575 or the high copy number plasmid vector pUC19 was constructed. This collection of recombinant plasmids represents roughly 93% of the PR4 genome. We also constructed a bank of 136 recombinant plasmids containing PR4 DNA fragments resulting from Hpall partial digestion. We have localized 13 genes on the phage PR4 genome through marker rescue with these phage DNA clones. These genes include the structural genes for the major capsid protein (P2) and a nonstructural protein (P6A) implicated in virus assembly.

Enrichment of the bacteriophage PR4 membrane in phosphatidylglycerol is not essential for phage assembly and infectivity.

The membrane phospholipids of bacteriophage PR4 grown on wild-type Escherichia coli are markedly enriched in phosphatidylglycerol (PG) relative to host phospholipids. To investigate the role of PG in phage assembly and infectivity, we propagated PR4 on an E. coli mutant defective in PG synthesis. The PG content of PR4 grown on the mutant host accounted for 0.4% of the total viral phospholipids, representing a 90-fold decrease in PG relative to the PG content of phage grown on a wild-type host. Phosphatidylethanolamine and phosphatidic acid, the two major phospholipid species present in these phage preparations, accounted for 88.4 and 9.4% of the total viral phospholipids, respectively. This drastic alteration of the phage phospholipid composition had little or no adverse effect on either the stability or infectivity of the phage. We conclude that the enrichment of the PR4 virion in PG does not reflect an absolute structural requirement of the phage and is not essential for phage infectivity.