A cross-sectional study of the knowledge and attitude of medical laboratory personnel regarding continuing professional development

Background:

Continuing professional development (CPD) in Medical Laboratory Scientists (MLS) is aimed at equipping laboratory professionals with the necessary skills to enhance practice. The laboratory scientists are usually the first contact between the patient and health care system in aspects of diagnosis and monitory of diseases. As such, it becomes imperative to assess the knowledge of laboratory personnel regarding CPD.

Materials and Methods:

Self-administered questionnaires were distributed to 200 laboratory personnel''s attending the maiden CPD workshop organized by the Association of MLS in Jos the Plateau state capital.

Results:

One hundred and thirty-five (82 males and 53 females) of the 200 administered questionnaires were returned. Only 32 of them (23.7%) attended CPD program in the last 1 year with 10 (7.5%) engaging in online CPD. Five (3.7%) of the respondents had the privilege to attend an international CPD. Majority (95.2%) of the respondents identified CPD as an essential component of professional career development. Lack of sponsorship was identified as a major setback in CPD efficiency by 93.8% of respondents. About 58 (46.4%) noted that poor attendance in CPD workshops was due to unavailability of policy guideline for CPD. One hundred and twenty (95.2%) of respondents had an aim of improving their skills after attending CPD workshops.

Conclusion:

The overall attitude of Nigerian MLS toward attending CPD workshop is poor; however, the knowledge regarding the importance of CPD is adequate. There exists a gap between sponsorship for CPD by various institutions and MLS.     

Surgical Repair of Anomalous Coronary Arteries Arising from the Opposite Sinus of Valsalva in Infants and Children

Abstract   Background: Unroofing of anomalous coronary artery originating from the opposite sinus of Valsalva has become the procedure of choice for this congenital lesion, with surgery performed in children as young as two years old. An increasing number of this anomaly is diagnosed in infancy with no clear indication whether surgical repair should be done in this age group. This paper reviews our experience with this anomaly, and focuses on its surgical management in infants. Methods: Between April 2002 and February 2007, eight patients underwent surgical repair of anomalous coronary artery arising from the opposite sinus of Valsalva and coursing between the aorta and pulmonary artery. Patients' age varied from two months to 28 years with a mean of 11.7 ± 11.1 years. Surgical Technique: Surgical repair involved unroofing the intramural segment of the anomalous coronary artery using cardiopulmonary bypass. Results: Two patients were younger than one year (Group A), and six patients were older than one year (group B). The mean intensive care unit stay was 2.5 ± 0.7 days for Group A and 2.8 ± 1.9 for Group B. The mean hospital stay was 4 ± 1.4 days for Group A and 4.3 ± 2.4 days for Group B. There was no mortality and no complications. The mean follow-up period is 14 ± 15.7 months with a range of one to 39 months. At the time of the last follow-up, all patients were asymptomatic in New York Heart Association class I and follow-up echocardiography on six of eight patients showed wide open coronary ostium. Conclusion: Unroofing the anomalous coronary artery arising from the opposite sinus of valsalva can be done in infants with minimal morbidity and mortality. Longer follow-up is needed to assess long-term results.     

Collection of Cancer Stage Data by Classifying Free-text Medical Reports

Cancer staging provides a basis for planning clinical management, but also allows for meaningful analysis of cancer outcomes and evaluation of cancer care services. Despite this, stage data in cancer registries is often incomplete, inaccurate, or simply not collected. This article describes a prototype software system (Cancer Stage Interpretation System, CSIS) that automatically extracts cancer staging information from medical reports. The system uses text classification techniques to train support vector machines (SVMs) to extract elements of stage listed in cancer staging guidelines. When processing new reports, CSIS identifies sentences relevant to the staging decision, and subsequently assigns the most likely stage. The system was developed using a database of staging data and pathology reports for 710 lung cancer patients, then validated in an independent set of 179 patients against pathologic stage assigned by two independent pathologists. CSIS achieved overall accuracy of 74% for tumor (T) staging and 87% for node (N) staging, and errors were observed to mirror disagreements between human experts.     

Serial assessment of lymphocytes and apoptosis in the prostate during coordinated intraprostatic dendritic cell injection and radiotherapy

Local radiotherapy plus intratumoral syngeneic dendritic cell injection can mediate apoptosis/cell death and immunological tumor eradication in murine models. A novel method of coordinated intraprostatic, autologous dendritic cell injection together with radiation therapy was prospectively evaluated in five HLA-A2(+) subjects with high-risk, localized prostate cancer, using androgen suppression, 45 Gy external beam radiation therapy in 25 fractions over 5 weeks, dendritic cell injections after fractions 5, 15 and 25 and then interstitial radioactive seed placement. Serial prostate biopsies before and during treatment showed increased apoptotic cells and parenchymal distribution of CD8(+) cells. CD8(+) T-cell responses to test peptides were assessed using an enzyme-linked immunosorbent spot IFN-γ production assay, demonstrating some prostate cancer-specific protein-derived peptides associated with increased titer. In conclusion, the technique was feasible and well-tolerated and specific immune responses were observable. Future trials could further test the utility of this approach and improve on temporal coordination of intratumoral dendritic cell introduction with particular timelines of therapy-induced apoptosis.     

Epigenetic analysis of cell-free DNA by fragmentomic profiling

Cell-free DNA (cfDNA) fragmentation patterns contain important molecular information linked to tissues of origin. We explored the possibility of using fragmentation patterns to predict cytosine-phosphate-guanine (CpG) methylation of cfDNA, obviating the use of bisulfite treatment and associated risks of DNA degradation. This study investigated the cfDNA cleavage profile surrounding a CpG (i.e., within an 11-nucleotide [nt] window) to analyze cfDNA methylation. The cfDNA cleavage proportion across positions within the window appeared nonrandom and exhibited correlation with methylation status. The mean cleavage proportion was ∼twofold higher at the cytosine of methylated CpGs than unmethylated ones in healthy controls. In contrast, the mean cleavage proportion rapidly decreased at the 1-nt position immediately preceding methylated CpGs. Such differential cleavages resulted in a characteristic change in relative presentations of CGN and NCG motifs at 5′ ends, where N represented any nucleotide. CGN/NCG motif ratios were correlated with methylation levels at tissue-specific methylated CpGs (e.g., placenta or liver) (Pearson’s absolute r > 0.86). cfDNA cleavage profiles were thus informative for cfDNA methylation and tissue-of-origin analyses. Using CG-containing end motifs, we achieved an area under a receiver operating characteristic curve (AUC) of 0.98 in differentiating patients with and without hepatocellular carcinoma and enhanced the positive predictive value of nasopharyngeal carcinoma screening (from 19.6 to 26.8%). Furthermore, we elucidated the feasibility of using cfDNA cleavage patterns to deduce CpG methylation at single CpG resolution using a deep learning algorithm and achieved an AUC of 0.93. FRAGmentomics-based Methylation Analysis (FRAGMA) presents many possibilities for noninvasive prenatal, cancer, and organ transplantation assessment.

Fragmentation patterns of cell-free DNA (cfDNA) molecules contain a wealth of molecular information related to their tissues of origin (1). For instance, compared with the background DNA molecules that are mainly derived from the hematopoietic system (2, 3), size shortening of fetal and tumoral DNA molecules occurs in the plasma DNA of pregnant women and cancer patients, respectively (4–6). In addition, a series of 10-bp periodicities were present in fetal and tumoral DNA molecules below 146 bp, with a relative reduction in the major peak at 166 bp (1). Such characteristic size profiles suggest that the fragmentation of cfDNA may be associated with nucleosome structures (5, 7). Many important characteristics pertaining to cfDNA fragmentation have been unveiled recently, such as nucleosome footprints (8, 9), fragment end motifs (10), preferred ends (7, 11), and jagged ends (12), which are examples of fragmentomic markers (1).cfDNA fragmentomics is an emergent and actively pursued area, with wide-ranging biological and clinical implications. It has been reported that the use of fragmentation patterns of cfDNA could inform the expression status of genes (13, 14). Using mouse models, DNA nucleases (e.g., DNASE1L3) were found to play important roles in the generation of plasma DNA molecules (15, 16). Fragmentomic features, such as cfDNA end motifs and jagged ends, were further demonstrated to be useful for monitoring DNA nuclease activities, providing biomarkers for autoimmune diseases (e.g., systemic lupus erythematosus) (17, 18). In addition, the deficiencies of nuclease activities in a mouse model resulted in altered DNA methylation profiles of plasma DNA molecules (19). However, how cfDNA fragmentation patterns interplay with DNA methylation in human individuals under different pathophysiological conditions, such as pregnancy and oncogenesis, and in healthy patients without nuclease deficiency, is unknown. It is also not known whether fragmentomic features can be used to deduce cfDNA methylation status.A widely employed way to assess DNA methylation is through bisulfite sequencing (20). A key limitation of this approach is the severe degradation of DNA molecules caused by the bisulfite treatment (21), which greatly increases the sampling variation when analyzing rare target molecules (e.g., tumoral cfDNA at early stages of cancer). Many efforts have been made toward overcoming this issue. For example, Vaisvila et al. developed enzymatic methyl sequencing for which DNA molecules were treated using tet methylcytosine dioxygenase 2 and T4 phage β-glucosyltransferase, followed by the apolipoprotein B mRNA editing enzyme catalytic subunit 3A (APOBEC3A) treatment. Cytosine conversion based on enzymatic processes was reported to be much less destructive (22). Recently, researchers developed approaches making use of third-generation sequencing technologies such as single-molecule real-time sequencing (Pacific Biosciences) (23) and nanopore sequencing (24) to analyze cytosine-phosphate-guanine (CpG) methylation patterns in native DNA molecules, theoretically overcoming the above-mentioned limitation. However, compared with second-generation sequencing (also called next-generation sequencing [NGS]) technologies, the throughput of third-generation sequencing technologies is generally lower and the sequencing cost per nucleotide (nt) is much higher, thus restricting its immediate application in clinical settings. Here, we explore the feasibility of enabling the assessment of DNA methylation using fragmentomic characteristics of cfDNA molecules deduced from NGS results without the use of bisulfite or enzymatic treatment. If successful, such an approach could leverage the high throughput of NGS while obviating the use of chemical/enzymatic conversion and could potentially be readily integrated into currently used NGS-based platforms for cfDNA analysis.In this study, we utilize the fragmentation patterns proximal to a CpG site for deducing its methylation status. The fragmentation pattern is depicted by the frequency of cfDNA fragment ends at each position within a certain nt range relative to a CpG of interest, termed a cleavage profile (Fig. 1). Such a cleavage profile varies according to the methylation status of the CpG site of interest, providing the basis for methylation analysis by using fragmentomic features. We further correlated two types of end motifs (CGN and NCG; N represents any nucleotide of A, C, G, or T) resulting from differential cutting in the measurement window related to DNA methylation, attempting to construct a simplified approach for methylation analysis. Modeling CpG methylation using cfDNA fragmentation may facilitate noninvasive prenatal testing, cancer detection, and tissue-of-origin analysis (Fig. 1). Furthermore, we explore the feasibility of using deep learning to deduce the methylation status at single CpG resolution through the cleavage profile (Fig. 1). We refer to this FRAGmentomics-based Methylation Analysis as FRAGMA in this study.Open in a separate windowFig. 1.Schematic for FRAGMA of cfDNA molecules. cfDNA molecules were sequenced by massively parallel sequencing and aligned to the human reference genome. The cleavage proportion within an 11-nt window (the cleavage measurement window) was used to measure the cutting preference of cfDNA molecules. The patterns of cleavage proportion within a window (the cleavage profile) depended on the methylation status of one or more CpG sites associated with that window. For example, a methylated CpG site might confer a higher probability of cfDNA cutting at the cytosine in the CpG context, but an unmethylated site might not. Such methylation-dependent differential fragmentation within a cleavage measurement window resulted in the change in CGN/NCG motif ratio. Thus, the CGN/NCG motif ratio provided a simplified version for reflecting CpG methylation, allowing cfDNA tissue-of-origin analysis of cfDNA and cancer detection. Furthermore, the great number of cleavage profiles derived from cfDNA molecules might provide an opportunity to train a deep learning model for methylation prediction at the single CpG resolution.     

Myxoedema madness: A case report

A case of psychosis in an elderly lady with hypothyroidism is described. The literature is reviewed with reference to the clinical diagnosis of myxoedema madness and the importance of its early detection.     

The phylogenetic position of the lichenicolous ascomycete Capronia peltigerae

The genus Capronia includes a number of lichenicolous (lichen-inhabiting) species, none of which have previously been characterized in vitro or considered in molecular phylogenetic studies. We cultured Capronia peltigerae from Peltigera rufescens and report here the growth of this species on a variety of media and its phylogenetic position based on the analyses of nuclear ribosomal RNA, mitochondrial ribosomal RNA, and RNA polymerase II (RPB1) gene sequences. This species differs from the majority of Capronia studied in axenic culture in lacking a conidial anamorph. Phylogenetic analyses position C. peltigerae outside the Herpotrichiellaceae within a robustly supported basal lineage of the Chaetothyriales composed primarily of melanized, rock-inhabiting anamorphic fungi. Our results demonstrate that Capronia, as circumscribed currently, is polyphyletic, but they do not resolve the relationship of C. peltigerae with members of the Chaetothyriaceae.     

A phase I dose escalation and pharmacokinetic study of vatalanib (PTK787/ZK 222584) in combination with paclitaxel in patients with advanced solid tumors

Purpose

To define the maximum-tolerated dose (MTD) for weekly paclitaxel administered in combination with daily vatalanib (PTK787/ZK 222584, PTK/ZK) and assess for a drug–drug interaction.

Methods

Patients were treated with escalating doses of weekly paclitaxel (75–85 mg/m²), and daily PTK/ZK (250–1,000 mg). During the first cycle only, paclitaxel was given on days 1 and 15, and PTK/ZK on days 3–28. Pharmacokinetic studies were conducted on cycle 1 days 1 and 15 for paclitaxel, and on cycle 1 day 15 for PTK/ZK. Therapy was given until disease progression.

Results

Twenty-seven patients were accrued to four dose levels. Two of five patients treated with paclitaxel 85 mg/m² and PTK/ZK 1,000 mg had Grade 3 transaminase elevation as dose-limiting toxicity. Paired PK analyses demonstrated a significant increase in paclitaxel clearance on day 15 (p = 0.006). Activity included one partial response and 11 patients with stable disease ≥4 months, including patients previously treated with paclitaxel.

Conclusions

The MTD for weekly paclitaxel plus daily PTK/ZK is 75 mg/m² and 750 mg. PK analysis revealed a significant drug–drug interaction, with an increase in paclitaxel clearance. This combination was well tolerated with evidence of anti-cancer activity and provides guidance for phase 2 planning.     

Stationary-phase mutation in the bacterial chromosome: Recombination protein and DNA polymerase IV dependence

Several microbial systems have been shown to yield advantageous mutations in slowly growing or nongrowing cultures. In one assay system, the stationary-phase mutation mechanism differs from growth-dependent mutation, demonstrating that the two are different processes. This system assays reversion of a lac frameshift allele on an F' plasmid in Escherichia coli. The stationary-phase mutation mechanism at lac requires recombination proteins of the RecBCD double-strand-break repair system and the inducible error-prone DNA polymerase IV, and the mutations are mostly -1 deletions in small mononucleotide repeats. This mutation mechanism is proposed to occur by DNA polymerase errors made during replication primed by recombinational double-strand-break repair. It has been suggested that this mechanism is confined to the F plasmid. However, the cells that acquire the adaptive mutations show hypermutation of unrelated chromosomal genes, suggesting that chromosomal sites also might experience recombination protein-dependent stationary-phase mutation. Here we test directly whether the stationary-phase mutations in the bacterial chromosome also occur via a recombination protein- and pol IV-dependent mechanism. We describe an assay for chromosomal mutation in cells carrying the F' lac. We show that the chromosomal mutation is recombination protein- and pol IV-dependent and also is associated with general hypermutation. The data indicate that, at least in these male cells, recombination protein-dependent stationary-phase mutation is a mechanism of general inducible genetic change capable of affecting genes in the bacterial chromosome.