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The RAD7 and RAD16 genes, which are essential for pyrimidine dimer removal from the silent mating type loci, are also required for repair of the nontranscribed strand of an active gene in Saccharomyces cerevisiae.

The rad16 mutant of Saccharomyces cerevisiae was previously shown to be impaired in removal of UV-induced pyrimidine dimers from the silent mating-type loci (D. D. Bang, R. A. Verhage, N. Goosen, J. Brouwer, and P. van de Putte, Nucleic Acids Res. 20:3925-3931, 1992). Here we show that rad7 as well as rad7 rad16 double mutants have the same repair phenotype, indicating that the RAD7 and RAD16 gene products might operate in the same nucleotide excision repair subpathway. Dimer removal from the genome overall is essentially incomplete in these mutants, leaving about 20 to 30% of the DNA unrepair…

Nucleases and Their Inhibitors: Exploring Biological Roles, Industrial Applications, and Challenges in Heterologous Expression.

Nucleases hydrolyze phosphodiester bonds and participate in numerous cellular and metabolic processes. Intracellular nucleases repair nonfunctional or damaged DNA using DNA base excision repair (BER), mismatch repair (MMR), and homologous recombination (HR). Apoptotic nucleases systematically degrade cellular DNA during programmed cell death (PCD). Non-apoptotic nucleases support DNA repair and replication. Small noncoding RNAs (sncRNAs) degrade the RNA of viral particles. Extracellular and membrane-associated nucleases replenish nucleotides, especially in biofilms where cells rely on addition…

Right atrial thrombus and pulmonary embolism one year after ventricular septal defect patch repair: successful surgical management of a complicated case.

BACKGROUND: Right heart thrombi are rare but life-threatening, with particularly high mortality when accompanied by pulmonary embolism (PE). Cardiac surgery may predispose to in-situ thrombus formation via suture lines or patch material, yet thromboembolic risk and preventive strategies following Ventricular Septal Defect (VSD) repair remain unclear. Here, we report a case of a young patient with a massive right atrial (RA) thrombus with PE one year after VSD repair in the absence of any known hypercoagulable state. CASE PRESENTATION: A 17-year-old male with a history of surgical VSD repair o

Temozolomide Treatment in Refractory Pituitary Adenomas and Pituitary Carcinomas.

BACKGROUND: Temozolomide (TMZ), a nonclassical alkylating agent, possesses lipophilic properties that allow it to cross the blood-brain barr … the potential impact of repair mechanisms such as direct repair, mismatch repair pathway, and base excision repair on TMZ treatment. The efficacy of TMZ analogs, combined TMZ therapies, and TMZ with nanomaterials following TMZ treatment failure remains uncertain. KEY MESSAGES: The involvement of experienced multidisciplinary pituitary teams in all management de …

PARP inhibitor response is enhanced in prostate cancer when XRCC1 expression is reduced.

Prostate cancer (PCa) is the second most common cancer worldwide and the fifth leading cause of cancer-related deaths among men. The emergen … deficiency can be exploited for PARPi treatment. XRCC1 is a DNA repair protein critical in the base excision repair (BER) and single strand break repair (SSBR) pathways. We analyzed PCa patients' cohorts and found that XRCC1 expression varies widely, with many patients showing low XRCC1 expression. We created XRCC1 deficiency in PCa models to examine PARPi sensit …

Cigarette smoke and decreased DNA repair by Xeroderma Pigmentosum Group C use a double hit mechanism for epithelial cell lung carcinogenesis.

Emerging evidence suggests a complex interplay of environmental and genetic factors in non-small cell lung cancer (NSCLC) development. Among these factors, compromised DNA repair plays a critical but incompletely understood role in lung tumorigenesis and concurrent lung diseases, such as chronic obstructive lung disease (COPD). In this study, we investigated the interplay between cigarette smoke, DNA damage and repair, focusing on the Nucleotide Excision Repair (NER) protein Xeroderma Pigmentosum Group C (XPC). We found decreased XPC mRNA expression in most NSCLCs compared to subject-matched, …

Механистическое восприятие аденовирусной устойчивости к ультрафиолетовому излучению: ремонт доза-депендента и запоздалое подавление реакции на повреждение ДНК-хоста.

Аденовирусы относятся к числу наиболее устойчивых к ультрафиолетовому воздействию переносимых водой патогенов, что создает значительные проблемы для стратегий дезинфекции при повторном использовании питьевой воды и очистке сточных вод. В рамках этого исследования изучаются механизмы восстановления ДНК, лежащие в основе аденовального восстановления после ультрафиолетового воздействия. Аденовирус типа 2 (Адв 2) был облучен УФ-излучением низкого давления (254 нм) при дозах от 0 до 80 мДж/см2 и затем введён в клетки А549. Вирусная инфекция, целостность генома и генная экспрессия (E1A, E4orf3, E4or

Совпадение в аннотации оригинала
Adenoviruses are among the most UV-resistant waterborne pathogens, posing significant challenges to disinfection strategies in potable reuse … s delayed, coinciding with viral transcription and consistent with transcription-coupled nucleotide excision repair (TC-NER). At higher doses, lesions were repaired rapidly, preceding early gene expression, suggesting activation of global-genome NER (GG-NER). Delayed expression of E4 genes at high UV doses may facilitate host-mediated repair before the viral shut …

Novel XPG (ERCC5) mutations affect DNA repair and cell survival after ultraviolet but not oxidative stress.

Nucleotide excision repair (NER) is the most flexible of all known DNA-repair mechanisms, and XPG is a 3'-endonuclease that participates in NER. Mutations in this gene (ERCC5) may result in the human syndrome xeroderma pigmentosum (XP) and, in some cases, in the complex phenotype of Cockayne syndrome (CS). Two Brazilian XP siblings, who were mildly affected, were investigated and classified into the XP-G group. The cells from these patients were highly ultraviolet (UV) sensitive but not sensitive to photosensitized methylene blue, an agent that causes oxidative stress. This phenotype is in con…

Robotic repair of complex vesicouterine fistula with and without hysterectomy.

OBJECTIVE: To present robotic repair of vesicouterine fistulae (VUF) with and without hysterectomy in 3 cases and to discuss the technique with its outcome. METHODS: Three patients were diagnosed with VUF, of whom 2 had a prior history of multiple cesarean sections and 1 had obstructed labor. Preoperative diagnosis of VUF was based on classic history, cystoscopy and imaging studies. All patients underwent pure robotic repair of VUF with hysterectomy in 1 case. The steps of the technique are cystoscopy, bilateral ureteral catheterization, port placement, adhesiolysis, separation of bladder and

Lingual nerve injury II. Observations on sensory recovery after micro-neurosurgical reconstruction.

The aim of this study was to report on neurosensory recovery after micro-surgical lingual nerve repair, and to evaluate the effect on recovery of age, delay in repair and gender of the patient. Seventy-four patients entered the study. The micro-surgical repair performed was direct nerve suture (n=71), external neurolysis (n=2) and excision of neuroma without nerve coaptation (n=1). A standardized neurosensory examination was employed in all patients before surgery and during follow up. Recovery was significant for perception of all tested stimuli: feather light touch, pin prick, pointed/dull d

Aprataxin, the causative protein for EAOH is a nuclear protein with a potential role as a DNA repair protein.

Early-onset ataxia with ocular motor apraxia and hypoalbuminemia (EAOH) is an autosomal recessive neurodegenerative disorder characterized b … logous with polynucleotidekinase-3'-phosphatase, which has been demonstrated to be involved in base excision repair, a subtype of single-strand DNA break repair, through interaction with XRCC1, DNA polymerase beta, and DNA ligase III. These results strongly support the possibility that aprataxin and XRCC1 constitute a multiprotein complex and are involved in sing …

Functional XPB/RAD25 redundancy in Arabidopsis genome: characterization of AtXPB2 and expression analysis.

The xeroderma pigmentosum complementation group B (XPB) protein is involved in both DNA repair and transcription in human cells. It is a component of the transcription factor IIH (TFIIH) and is responsible for DNA helicase activity during nucleotide (nt) excision repair (NER). Its high evolutionary conservation has allowed identification of homologous proteins in different organisms, including plants. In contrast to other organisms, Arabidopsis thaliana harbors a duplication of the XPB orthologue (AtXPB1 and AtXPB2), and the proteins encoded by the duplicated genes are very similar (95% amino …

Targeted deletion of mNth1 reveals a novel DNA repair enzyme activity.

DNA N-glycosylase/AP (apurinic/apyrimidinic) lyase enzymes of the endonuclease III family (nth in Escherichia coli and Nth1 in mammalian organisms) initiate DNA base excision repair of oxidized ring saturated pyrimidine residues. We generated a null mouse (mNth1(-/-)) by gene targeting. After almost 2 years, such mice exhibited no overt abnormalities. Tissues of mNth1(-/-) mice contained an enzymatic activity which cleaved DNA at sites of oxidized thymine residues (thymine glycol [Tg]). The activity was greater when Tg was paired with G than with A. This is in contrast to Nth1, which is more a…

Toxicity of organic and inorganic mercury to Saccharomyces cerevisiae.

In this study the effect if six different forms of mercury on the growth of the yeast Saccharomyces cerevisiae is presented. Five kinds of strains of S. cerevisiae were used. They were a wild type, a mercury-resistant type, and three mutants: mutation repair-deficient mutant, excision repair-deficient mutant, and recombination repair-deficient mutant. In terms of EC50 toward the wild-type strain, the toxicity order for the inorganic forms was Hg(NO3)2>HgSO4>HgCl2. Monovalent nitrate mercury Hg(NO3)2 was more toxic than bivalent Hg(NO3)2. The toxicity of organic mercury CH3HgCl on cell growth w…

Characterization of X-ray-induced immunostaining of proliferating cell nuclear antigen in human diploid fibroblasts.

The repair of X-ray-induced DNA damage related to the proliferating cell nuclear antigen (PCNA) was characterized in human diploid fibroblas … duced DNA damage in vivo, but the repair initiation step could be different from that of nucleotide excision repair initiated by XP proteins.

[Massive pulmonary embolism treated with a reduced dose of alteplase in a patient with acute renal failure].

Repair of damaged DNA is a complex process, particularly when it is compacted into nucleosomes. There are a number of genetic disorders with deficiencies in DNA repair. Knowledge of the genes and proteins involved in these repair deficiencies is critical in developing an understanding of the molecular mechanisms utilized by proteins in the DNA repair pathways. One of these genetic disorders is xeroderma pigmentosum (XP), which is defective in nucleotide excision repair (NER). Patients in XP complementation group A (XP-A) are among the most severely affected with the lowest levels of DNA repair…

Xeroderma pigmentosum and molecular cloning of DNA repair genes.

Human cells from patients suffering with xeroderma pigmentosum (XP) characterized by extreme sensitivity to UV light and a high incidence of skin tumors fall into seven complementation groups, XPA to XPG, and are lacking a functional helicase, endonuclease, or lesion-recognizing protein involved in the initial steps during nucleotide excision repair (NER); a number of proteins involved in DNA repair are termed XPA to XPG depending on which one is defective in a particular complementation group of XP and include: (i) proteins involved in the recognition of (6-4) photoproducts (XPE) and of a bro…

Leiomyosarcoma of the Face.

Leiomyosarcoma is a rare form of soft tissue neoplasm, with only 1% to 5% occurring in the head and neck region. Current recommended treatment suggests surgical excision with a wide lateral margin, but no definite guidelines regarding excisional margin have been established yet. Recently, complete excision with a narrow surgical margin has been recommended, and the authors present a case of cutaneous leiomyosarcoma on the face that was successfully managed by complete removal with a narrow excisional margin. A 74-year-old woman presented with a 3 cm sized, rapidly growing cutaneous mass on her

Evidence that xeroderma pigmentosum cells do not perform the first step in the repair of ultraviolet damage to their DNA. 1969.

Xeroderma pigmentosum (XP) is a recessively transmitted disorder of man characterized by increased sensitivity to ultraviolet light. Homozygous, affected individuals, upon exposure to sunlight, sustain severe damage to the skin; this damage is characteristically followed by multiple basal and squamous cell carcinomas and not uncommonly by other malignant neoplasia. A tissue culture cell line was derived from the skin of a man with XP. Our measurements of ultraviolet-induced pyrimidine dimers in cellular DNA show that normal diploid human skin fibroblasts excise up to 70 per cent of the dimers

Delayed repair of skin cancer defects.

PURPOSE: A review of surgical outcomes in 280 patients who underwent in-office excision of skin lesions, open wound therapy, and delayed reconstruction is presented. Advantages of open wound therapy and delayed reconstruction are discussed. PATIENTS AND METHODS: The surgical records of all patients treated between January 1, 1994 and December 31, 1996 were evaluated for outcome and complications. RESULTS: One hundred seventeen patients presented with biopsy-confirmed malignant skin lesions of the head and neck. After surgical excision of the malignancy, the wounds were treated with a semiocc