Clinical Features of Takotsubo Syndrome and Its Differential Diagnostic Criteria in Clinical Nursing Practice: A Review of the Literature.

Purpose Of Review: Takotsubo cardiomyopathy (TCM) is a heart disease that mimics the symptoms of a myocardial infarction (MI). The exact cause of TCM is unknown, but the main theory is that the syndrome is triggered by an excessive release of catecholamines, a consequence of factors related to stress or severe emotional distress. The aim of this review is to summarize the various scientific journal articles on the nursing differential diagnosis of TCM, on the specific nurse training (particularly the role of the Advanced Practice Nurse, APN), and on the nursing educational support for the patient after hospital discharge.

CSA and CSB play a role in the response to DNA breaks.

CS proteins have been involved in the repair of a wide variety of DNA lesions. Here, we analyse the role of CS proteins in DNA break repair by studying histone H2AX phosphorylation in different cell cycle phases and DNA break repair by comet assay in CS-A and CS-B primary and transformed cells. Following methyl methane sulphate treatment a significant accumulation of unrepaired single strand breaks was detected in CS cells as compared to normal cells, leading to accumulation of double strand breaks in S and G2 phases.

Overexpression of parkin rescues the defective mitochondrial phenotype and the increased apoptosis of Cockayne Syndrome A cells.

The ERCC8/CSA gene encodes a WD-40 repeat protein (CSA) that is part of a E3-ubiquitin ligase/COP9 signalosome complex. When mutated, CSA causes the Cockayne Syndrome group A (CS-A), a rare recessive progeroid disorder characterized by sun sensitivity and neurodevelopmental abnormalities. CS-A cells features include ROS hyperproduction, accumulation of oxidative genome damage, mitochondrial dysfunction and increased apoptosis that may contribute to the neurodegenerative process.

The response to oxidative stress and metallomics analysis in a twin study: The role of the environment.

Inefficient response to oxidative stress has been associated with ageing and health risk. Metals are known to inhibit DNA repair and may modify the antioxidant response. How genetic variability and lifestyle factors modulate the response to oxidative stress is poorly explored.

The cross talk between pathways in the repair of 8-oxo-7,8-dihydroguanine in mouse and human cells.

Although oxidatively damaged DNA is repaired primarily via the base excision repair (BER) pathway, it is now evident that multiple subpathways are needed. Yet, their relative contributions and coordination are still unclear. Here, mouse embryo fibroblasts (MEFs) from selected nucleotide excision repair (NER) and/or BER mouse mutants with severe (Csb(m/m)/Xpa(-/-) and Csb(m/m)/Xpc(-/-)), mild (Csb(m/m)), or no progeria (Xpa(-/-), Xpc(-/-), Ogg1(-/-), Csb(m/m)/Ogg1(-/-)) or wild-type phenotype were exposed to an oxidizing agent, potassium bromate, and genomic 8-oxo-7,8-dihydroguanine (8-oxoGua) levels were measured by HPLC-ED.

Polymorphic DNA repair and metabolic genes: a multigenic study on gastric cancer.

Risk factors for gastric cancer (GC) include inter-individual variability in the inflammatory response to Helicobacter pylori infection, in the ability of detoxifying DNA reactive species and repairing DNA damage generated by oxidative stress and dietary carcinogens. To evaluate the association between polymorphic DNA repair genes and GC risk, a case-control study including 314 histologically confirmed GC patients and 548 healthy controls was conducted in a GC high-risk area in Tuscany, Italy. Polymorphic variants of base excision repair (APE1-D148E, XRCC1-R194W, XRCC1-R399Q and OGG1-S326C), nucleotide excision repair (XPC-PAT, XPA-23G>A, ERCC1-19007T>C and XPD-L751Q), recombination (XRCC3-T241M) and alkylation damage reversal (MGMT-L84F) were tested for their potential role in the development of GC by using logistic regression models.

The role of CSA in the response to oxidative DNA damage in human cells.

Cockayne syndrome (CS) is a rare genetic disease characterized by severe growth, mental retardation and pronounced cachexia. CS is most frequently due to mutations in either of two genes, CSB and CSA. Evidence for a role of CSB protein in the repair of oxidative DNA damage has been provided recently.

New functions of XPC in the protection of human skin cells from oxidative damage.

Xeroderma pigmentosum (XP) C is involved in the recognition of a variety of bulky DNA-distorting lesions in nucleotide excision repair. Here, we show that XPC plays an unexpected and multifaceted role in cell protection from oxidative DNA damage. XP-C primary keratinocytes and fibroblasts are hypersensitive to the killing effects of DNA-oxidizing agents and this effect is reverted by expression of wild-type XPC.

Cell type and DNA damage specific response of human skin cells to environmental agents.

The epidermis has evolved to provide a barrier against the environment, which is essential for survival. This barrier is constituted and continuously regenerated by terminally differentiating keratinocytes. Here, we summarize the main features of the response to UVB and oxidizing agents of human keratinocytes and compare it with that of fibroblasts.

Differential role of transcription-coupled repair in UVB-induced response of human fibroblasts and keratinocytes.

Most solar radiation-induced skin cancers arise in keratinocytes. In the human epidermis, protection against cancer is thought to be mediated mainly by nucleotide excision repair (NER) of UVB-induced cyclobutane pyrimidine dimers, and by elimination of the damaged cells by apoptosis. NER consists of two subpathways: global genome repair (GGR) and transcription-coupled repair (TCR).

Characterization of the ultraviolet B and X-ray response of primary cultured epidermal cells from patients with disseminated superficial actinic porokeratosis.

Background: Disseminated superficial actinic porokeratosis (DSAP) is the most common porokeratosis and is characterized by multiple keratotic lesions which tend to occur at sun-exposed sites. A mild hypersensitivity to X-rays has been reported for DSAP-derived fibroblasts and frequent over-expression of p53 has been found in lesional epidermis.

Objectives: In order to clarify whether genome maintenance mechanisms might be compromised in this disease the following approaches were undertaken: (i) primary cultured keratinocytes and fibroblasts from DSAP patients were characterized for ultraviolet (UV) B and X-ray response; (ii) 15 lesions were studied for p53 mutations, and (iii) the differentiation status of DSAP-derived keratinocytes was evaluated.

UV mutation signature in tumor suppressor genes involved in skin carcinogenesis in xeroderma pigmentosum patients.

Molecular analysis of p53 and patched (PTCH), two candidate tumor suppressor genes for non-melanocytic skin cancer, was performed in skin tumors from six patients affected by the cancer-prone disease xeroderma pigmentosum (XP). UV-specific p53 mutations were detected at a frequency of 38-50% in all the tumor types analysed, including melanomas. Additional analysis of PTCH mutations in the subset of eight basal call carcinomas (BCC) revealed a very high mutation frequency of this gene (90%) which exceeded that detected in the p53 gene in the same tumors (38%).

Factors that influence the DNA repair capacity of normal and skin cancer-affected individuals.

DNA repair capacity (DRC) was studied in 49 patients affected by basal cell carcinoma (BCC) and 68 cancer-free controls belonging to a larger case-control population enrolled for studying BCC risk factors. DRC was measured in the subjects' peripheral blood lymphocytes by using a host-cell reactivation assay that measures cellular activation of a reporter gene irradiated with UV light. A statistically significant age-related decline in DRC was observed in the controls from 20 to 70 years of age but not in the BCC cases.

p53 mutations and chromosome instability in basal cell carcinomas developed at an early or late age.

Tumor DNA from 45 primary basal cell carcinoma (BCC) biopsies was screened for p53 gene mutations, chromosome 9 allele loss, and microsatellite instability. p53 mutation frequency increased significantly as a function of the age at BCC onset ranging from 6% (1/16) in early BCC (before age 40 years) to 35% (10/29) in late BCC. All p53 mutations found implicated sunlight as the mutagen.

Misincorporation rate and type on the leading and lagging strands of UV-damaged DNA.

We have examined the fidelity of replication of the leading and lagging strands of UV-irradiated DNA by using an EBV-derived shuttle vector system which contains as marker gene for mutation analysis the bacterial gpt gene in both orientations relative to the EBV oriP. Human cells stably transformed with this vector were UV irradiated and gpt mutation rate and type were analysed. An increased mutagenicity associated with UV irradiation was observed, but the average error frequency was unaffected by the direction of replication of the target gene.

Genetic alterations in skin cancer.

Cancer is a multi-stage process in which the accumulation of genetic changes allows clonal expansion of abnormal cells that will eventually form a tumor. Skin cancer is the most common malignancy affecting human beings. Mutations of the tumor suppressor gene p53 are often found in non-melanoma skin cancer and pre-invasive lesions, like actinic keratosis.

Strand bias of ultraviolet light-induced mutations in a transcriptionally active gene in human cells.

Ultraviolet (UV)-induced repair and mutational spectra were analyzed in an inducible marker gene, the metallothionein-l/guamine-xanthine phosphoribosyl transferase (gpt) fusion gene, carried by an Epstein-Barr virus-derived shuttle vector episomically maintained in human cells. The repair rate of UV photodimers from the shuttle-vector molecules was typical of transcriptionally active sequences, 70% of the dimers being removed within 8 h after irradiation. The spectrum obtained under basal gene transcription was compared with that obtained under induced transcription.

Molecular analysis of mutations induced by chemical carcinogens in mammalian cells. II. The use of recombinant DNA vectors.

One approach to molecular and mechanistic studies of mutagenesis in mammalian cells is to introduce a mutational target gene into the cells as part of a shuttle vector which is capable of replication in both mammalian cells and bacteria. Following mutagenesis in the mammalian cell host, the shuttle vector sequences are recovered from the mammalian cells and introduced into bacteria, where large amounts of the mutant gene can be produced for sequence analysis. The variety of shuttle vector systems which have been developed for this purpose will be described.

Mutagenic processing of ethylation damage in mammalian cells: the use of methoxyamine to study apurinic/apyrimidinic site-induced mutagenesis.

The aldehyde reagent methoxyamine is able to interact with apurinic/apyrimidinic sites formed in vivo within cells and displays both an anti-cytotoxic and an antimutagenic activity on N-ethyl-N'-nitro-N-nitrosoguanidine-induced DNA damage in Chinese hamster ovary cells. To clarify the underlying mechanism we have examined the mutational spectra induced by N-ethyl-N'-nitro-N-nitrosoguanidine alone and in the presence of methoxyamine in the hypoxanthine-guanine phosphoribosyltransferase gene of Chinese hamster ovary cells. In both cases all mutations were base pair substitutions, and their distribution among various classes did not differ significantly.

Quantitative relationship between ethylated DNA bases and gene mutation at two loci in CHO cells.

In a previous study we showed that the formation of O6-ethylguanine (O6-EtGua) in the DNA of CHO cells in culture correlated with mutations induced by ethylnitrosourea (ENU) and diethylsulfate (DES) at the hypoxanthine-guanine-phosphoribosyltransferase (hprt) locus but not at the Na, K-ATPase locus. This study was extended to another ethylating agent, ethyl methanesulfonate (EMS). DNA adduct formation and induction of mutation at the two gene loci were determined simultaneously in CHO cells after EMS exposure.

N-methyl-N-nitrosourea-induced mutations in human cells. Effects of the transcriptional activity of the target gene.

In this study we addressed the question as to whether the mutagenesis by methylating agents is affected by the transcriptional activity of the damaged gene. An Epstein-Barr virus (EBV)-derived shuttle vector system was developed where the genetic target for mutation analysis, the bacterial gpt gene, is under the control of an eukaryotic inducible promoter in plasmid pF1-EBV and lacks the eukaryotic promoter in plasmid pF2-EBV. Two human cell lines that episomically maintain these shuttle vectors were established.