Airway management in paediatric emergencies outside of an intensive care setting: a quality improvement project using Lean/Six Sigma methodology.

Use of a Lean/Six Sigma methodology in a quality improvement project to reduce variation and improve safety in airway management outside of the intensive care environment in a tertiary paediatric hospital.

Introduction of a simple guideline to improve neurological assessment in paediatric patients presenting with upper limb fractures.

BACKGROUND: Neurological examination in children presenting with upper limb fractures is often poorly performed in the Emergency Department (ED). We aimed to assess the improvement in documented neurological examination for children presenting with upper limb fractures following introduction of a simple guideline. METHODS: We developed and introduced a simple guideline for upper limb neurological assessment in children ('rock, paper, scissors, OK'). We compared documentation of neurological examination and nerve injury detection at our hospital before and after introduction of this guideline, as well as for children admitted from external hospitals (where the guideline had not been introduced). RESULTS: In the period following guideline introduction, 97 children with upper limb fractures were admitted (46% presenting directly to our ED and 54% admitted from external hospitals). This cohort was similar in number and distribution to the cohort reviewed prior to the guideline. Documentation of neurological examination in our ED increased from 92% to 98% after guideline introduction. Documented information on nerves examined also increased from 2% to 68% (p<0.01). Prior to the guideline, there were six nerve injuries, all of which were missed in our ED. After guideline introduction, there were four nerve injuries, all of which were detected in our ED. Documentation and nerve injury detection at external hospitals over the same time period showed no improvement. CONCLUSIONS: A simple guideline to assist neurological examination in children with upper limb fractures can significantly improve the quality of documented neurological assessment and nerve injury detection.

Ocular manifestations of xeroderma pigmentosum: long-term follow-up highlights the role of DNA repair in protection from sun damage.

OBJECTIVE: Xeroderma pigmentosum (XP) is a rare autosomal recessive disease caused by mutations in DNA repair genes. Clinical manifestations of XP include mild to extreme sensitivity to ultraviolet radiation resulting in inflammation and neoplasia in sun-exposed areas of the skin, mucous membranes, and ocular surfaces. This report describes the ocular manifestations of XP in patients systematically evaluated in the Clinical Center at the National Institutes of Health. DESIGN: Retrospective observational case series. PARTICIPANTS: Eighty-seven participants, aged 1.3 to 63.4 years, referred to the National Eye Institute (NEI) for examination from 1964 to 2011. Eighty-three patients had XP, 3 patients had XP/Cockayne syndrome complex, and 1 patient had XP/trichothiodystrophy complex. METHODS: Complete age- and developmental stage-appropriate ophthalmic examination. MAIN OUTCOME MEASURES: Visual acuity; eyelid, ocular surface, and lens pathology; tear film and tear production measures; and cytologic analysis of conjunctival surface swabs. RESULTS: Of the 87 patients, 91% had at least 1 ocular abnormality. The most common abnormalities were conjunctivitis (51%), corneal neovascularization (44%), dry eye (38%), corneal scarring (26%), ectropion (25%), blepharitis (23%), conjunctival melanosis (20%), and cataracts (14%). Thirteen percent of patients had some degree of visual axis impingement, and 5% of patients had no light perception in 1 or both eyes. Ocular surface cancer or a history of ocular surface cancer was present in 10% of patients. Patients with an acute sunburning skin phenotype were less likely to develop conjunctival melanosis and ectropion but more likely to develop neoplastic ocular surface lesions than nonburning patients. Some patients also showed signs of limbal stem cell deficiency. CONCLUSIONS: Our longitudinal study reports the ocular status of the largest group of patients with XP systematically examined at 1 facility over an extended period of time. Structural eyelid abnormalities, neoplasms of the ocular surface and eyelids, tear film and tear production abnormalities, ocular surface disease and inflammation, and corneal abnormalities were present in this population. Burning and nonburning patients with XP exhibit different rates of important ophthalmologic findings, including neoplasia. In addition, ophthalmic characteristics can help refine diagnoses in the case of XP complex phenotypes. DNA repair plays a major role in protection of the eye from sunlight-induced damage.

Patient-Partners as Educators: Vulnerability Related to Sharing of Lived Experience.

Patient-partners are invaluable in health professions' education. Sharing their lived experiences with prospective and current healthcare providers can provide an opportunity for these participants to hone their patient-centric skills. However, sharing stories publicly is a vulnerable role and may feel emotionally risky for patient-partners. Using reflective dialogue, this manuscript outlines recommendations through the Sender-Receiver Model of Communication for Patient-Partners encounters when working with patient-partners in health professions' education. These recommendations include recognizing that: Patient-partners need to consider if they are ready to share their story. Some stories are wounds requiring further healing; other stories are scars fully processed by patient-partners and ready to be shared publicly.The audience should differentiate between questions that can promote critical thinking versus feel like a "personal attack." Audiences should recognize vulnerability patient-partners may experience in sharing their stories and engage accordingly.Pre-session and post-session debriefs are important. Shared stories may elicit intense emotions from patient-partners and audiences. Both groups should be given an opportunity to process and work through emotions.

Evidence for EpCAM and Cytokeratin Expressing Epithelial Cells in Normal Human and Murine Blood and Bone Marrow.

Epithelial cells have been identified in the blood and bone marrow of patients with cancer and other diseases. However, the presence of normal epithelial cells in the blood and bone marrow of healthy individuals has yet to be identified in a consistent way. Presented here is a reproducible method for isolating epithelial cells from healthy human and murine blood and bone marrow (BM) using flow cytometry and immunofluorescence (IF) microscopy. Epithelial cells in healthy individuals were first identified and isolated via flow cytometry using epithelial cell adhesion molecule (EpCAM). These EpCAM+ cells were confirmed to express keratin using immunofluorescence microscopy in Krt1-14;mTmG transgenic mice. Human blood samples had 0.18% ± 0.0004 EpCAM+ cells (SEM; n=7 biological replicates, 4 experimental replicates). In human BM, 3.53% ± 0.006 (SEM; n=3 biological replicates, 4 experimental replicates) of mononuclear cells were EpCAM+. In mouse blood, EpCAM+ cells constituted 0.45% ± 0.0006 (SEM; n=2 biological replicates, 4 experimental replicates), and in mouse BM, 5.17% ± 0.001 (SEM; n=3 biological replicates, 4 experimental replicates) were EpCAM+. In mice, all the EpCAM+ cells were immunoreactive to pan-cytokeratin, as determined by IF microscopy. Results were confirmed using Krt1-14;mTmG transgenic mice, with low (8.6 native GFP+ cells per 106 cells analyzed; 0.085% of viable cells), but significant numbers (p < 0.0005) of GFP+ cells present in normal murine BM, that were not the result of randomness compared with multiple negative controls. Further, EpCAM+ cells in mouse blood were more heterogeneous than CD45+ cells (0.58% in BM; 0.13% in blood). These observations conclude that cells expressing cytokeratin proteins are reproducibly detectable among mononuclear cells from human and murine blood and BM. We demonstrate a method of tissue harvesting, flow cytometry, and immunostaining that can be used to identify and determine the function of these pan-cytokeratin epithelial cells in healthy individuals.

Cancer and neurologic degeneration in xeroderma pigmentosum: long term follow-up characterises the role of DNA repair.

BACKGROUND: The frequency of cancer, neurologic degeneration and mortality in xeroderma pigmentosum (XP) patients with defective DNA repair was determined in a four decade natural history study. METHODS: All 106 XP patients admitted to the National Institutes of Health from 1971 to 2009 were evaluated from clinical records and follow-up. RESULTS: In the 65 per cent (n=69) of patients with skin cancer, non-melanoma skin cancer (NMSC) was increased 10,000-fold and melanoma was increased 2000-fold in patients under age 20. The 9 year median age at diagnosis of first non-melanoma skin cancer (NMSC) (n=64) was significantly younger than the 22 year median age at diagnosis of first melanoma (n=38)-a relative age reversal from the general population suggesting different mechanisms of carcinogenesis between NMSC and melanoma. XP patients with pronounced burning on minimal sun exposure (n=65) were less likely to develop skin cancer than those who did not. This may be related to the extreme sun protection they receive from an earlier age, decreasing their total ultraviolet exposure. Progressive neurologic degeneration was present in 24% (n=25) with 16/25 in complementation group XP-D. The most common causes of death were skin cancer (34%, n=10), neurologic degeneration (31%, n=9), and internal cancer (17%, n=5). The median age at death (29 years) in XP patients with neurodegeneration was significantly younger than those XP patients without neurodegeneration (37 years) (p=0.02). CONCLUSION: This 39 year follow-up study of XP patients indicates a major role of DNA repair genes in the aetiology of skin cancer and neurologic degeneration.

Histone deacetylase inhibitors sodium butyrate and valproic acid delay spontaneous cell death in purified rat retinal ganglion cells.

PURPOSE: Histone deacetylase inhibitors (HDACi) have neuroprotective effects under various neurodegenerative conditions, e.g., after optic nerve crush (ONC). HDACi-mediated protection of central neurons by increased histone acetylation has not previously been demonstrated in rat retinal ganglion cells (RGCs), although epigenetic changes were shown to be associated with cell death after ONC. We investigated whether HDACi can delay spontaneous cell death in purified rat RGCs and analyzed concomitant histone acetylation levels. METHODS: RGCs were purified from newborn (postnatal day [P] 0-P2) rat retinas by immunopanning with antibodies against Thy-1.1 and culturing in serum-free medium for 2 days. RGCs were treated with HDACi, each at several different concentrations: 0.1-10 mM sodium butyrate (SB), 0.1-2 mM valproic acid (VPA), or 0.5-10 nM trichostatin A (TSA). Negative controls were incubated in media alone, while positive controls were incubated in 0.05-0.4 IU/µl erythropoietin. Survival was quantified by counting viable cells using phase-contrast microscopy. The expression of acetylated histone proteins (AcH) 3 and 4 was analyzed in RGCs by immunohistochemistry. RESULTS: SB and VPA enhanced RGC survival in culture, with both showing a maximum effect at 0.1 mM (increase in survival to 188% and 163%, respectively). Their neuroprotective effect was comparable to that of erythropoietin at 0.05 IU/µl. TSA 0.5-1.0 nM showed no effect on RGC survival, and concentrations ≥ 5 nM increased RGC death. AcH3 and AcH4 levels were only significantly increased in RGCs treated with 0.1 mM SB. VPA 0.1 mM produced only a slight effect on histone acetylation. CONCLUSIONS: Millimolar concentrations of SB and VPA delayed spontaneous cell death in purified RGCs; however, significantly increased histone acetylation levels were only detectable in RGCs after SB treatment. As the potent HDACi TSA was not neuroprotective, mechanisms other than histone acetylation may be the basis on which SB and VPA are acting in this model. Additional studies are necessary to identify HDACi-targeted genes and pathways involved in RGC protection.

Ocular manifestations of trichothiodystrophy.

OBJECTIVE: Trichothiodystrophy (TTD) is a rare, autosomal recessive disorder characterized by sulfur-deficient brittle hair and multisystem abnormalities. Many TTD patients have a defect in known DNA repair genes. This report systematically evaluates the ocular manifestations of the largest-to-date cohort of TTD patients and xeroderma pigmentosum (XP)/TTD patients. DESIGN: Case series. PARTICIPANTS: Thirty-two participants, ages 1 to 30 years, referred to the National Eye Institute for examination from 2001 to 2010; 25 had TTD and 7 had XP/TTD. METHODS: Complete, age- and developmental stage-appropriate ophthalmic examination. MAIN OUTCOME MEASURES: Visual acuity (VA), best-corrected VA, ocular motility, state of the ocular surface and corneal endothelial cell density, corneal diameter, and lens assessment. RESULTS: Developmental abnormalities included microcornea (44% TTD), microphthalmia (8% TTD, 14% XP/TTD), nystagmus (40% TTD), and infantile cataracts (56% TTD, 86% XP/TTD). Corrective lenses were required by 65% of the participants, and decreased best-corrected VA was present in 28% of TTD patients and 71% of XP/TTD patients. Degenerative changes included dry eye (32% TTD, 57% XP/TTD) and ocular surface disease identified by ocular surface staining with fluorescein (32% TTD) that usually are exhibited by much older patients in the general population. The 2 oldest TTD patients exhibited clinical signs of retinal/macular degeneration. Four XP/TTD patients presented with corneal neovascularization. CONCLUSIONS: These TTD and XP/TTD study participants had a wide variety of ocular findings including refractive error, infantile cataracts, microcornea, nystagmus, and dry eye/ocular surface disease. Although many of these can be ascribed to abnormal development--likely owing to abnormalities in basal transcription of critical genes--patients may also have a degenerative course. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosures may be found after the references.

High-risk pregnancy and neonatal complications in the DNA repair and transcription disorder trichothiodystrophy: report of 27 affected pregnancies.

OBJECTIVE: To identify the frequency of pregnancy and neonatal complications in pregnancies carrying fetuses affected with trichothiodystrophy (TTD). METHODS: We identified pregnancy and neonatal complications and serum screening results from mothers of TTD patients in a DNA repair diseases study from 2001 to 2011. RESULTS: Pregnancy reports of 27 TTD patients and their 23 mothers were evaluated and 81% of the pregnancies had complications: 56% had preterm delivery, 30% had preeclampsia, 19% had placental abnormalities, 11% had HELLP syndrome, and 4% had an emergency c-section for fetal distress, while 44% had two or more complications. Only 19% of the pregnancies delivered at term without complications. Eight of the ten pregnancies tested had abnormal multiple marker results including elevated levels of human chorionic gonadotrophin. Eighty-five percent of the neonates had complications: 70% were low birth weight (<2500 g), 35% had birth weight < 10 centile for gestational age, 70% had NICU admission, 67% had a collodion membrane, and 31% of the 16 males had cryptorchidism. Cataracts were present in 54% of the TTD patients examined. CONCLUSION: TTD is a multisystem disease that predisposes mothers of affected patients to substantial risks for pregnancy complications and TTD neonates have a high incidence of multiple abnormalities.

XPC branch-point sequence mutations disrupt U2 snRNP binding, resulting in abnormal pre-mRNA splicing in xeroderma pigmentosum patients.

Mutations in two branch-point sequences (BPS) in intron 3 of the XPC DNA repair gene affect pre-mRNA splicing in association with xeroderma pigmentosum (XP) with many skin cancers (XP101TMA) or no skin cancer (XP72TMA), respectively. To investigate the mechanism of these abnormalities we now report that transfection of minigenes with these mutations revealed abnormal XPC pre-mRNA splicing that mimicked pre-mRNA splicing in the patients' cells. DNA oligonucleotide-directed RNase H digestion demonstrated that mutations in these BPS disrupt U2 snRNP-BPS interaction. XP101TMA cells had no detectable XPC protein but XP72TMA had 29% of normal levels. A small amount of XPC protein was detected at sites of localized ultraviolet (UV)-damaged DNA in XP72TMA cells which then recruited other nucleotide excision repair (NER) proteins. In contrast, XP101TMA cells had no detectable recruitment of XPC or other NER proteins. Post-UV survival and photoproduct assays revealed greater reduction in DNA repair in XP101TMA cells than in XP72TMA. Thus mutations in XPC BPS resulted in disruption of U2 snRNP-BPS interaction leading to abnormal pre-mRNA splicing and reduced XPC protein. At the cellular level these changes were associated with features of reduced DNA repair including diminished NER protein recruitment, reduced post-UV survival and impaired photoproduct removal.

International liquid biopsy standardization alliance white paper.

The promise of precision medicine as a model to customize health care to the individual patient is heavily dependent upon new genetic tools to classify and characterize diseases and their hosts. Liquid biopsies serve as a safe alternative to solid biopsies and are thus a useful and critical component to fully realizing personalized medicine. The International Liquid Biopsy Standardization Alliance (ILSA) comprises organizations and foundations that recognize the importance of working towards the global use of liquid biopsy in oncology practice to support clinical decision making and regulatory considerations and seek to promote it in their communities. This manuscript provides an overview of the independent liquid biopsy- and standardization-based programs engaged with ILSA, their objectives and progress to date, and the tools and resources each is developing to contribute to the field. It also describes the unique areas of effort as well as synergy found within the group.

Strict sun protection results in minimal skin changes in a patient with xeroderma pigmentosum and a novel c.2009delG mutation in XPD (ERCC2).

We examined the clinical, molecular and genetic features of a 16-year-old boy (XP2GO) with xeroderma pigmentosum (XP) and progressive neurological symptoms. The parents are not consanguineous. Increased sun sensitivity led to the diagnosis of XP at 2 years of age and a strict UV protection scheme was implemented. Besides recurrent conjunctivitis and bilateral pterygium, only mild freckling was present on his lips. He shows absent deep tendon reflexes, progressive sensorineural deafness and progressive mental retardation. MRI shows diffuse frontal cerebral atrophy and dilated ventricles. Symptoms of trichothiodystrophy (brittle hair with a tiger-tail banding pattern on polarized microscopy) or Cockayne syndrome (cachectic dwarfism, cataracts, pigmentary retinopathy and spasticity) were absent. XP2GO fibroblasts showed reduced post-UV cell survival (D(37) = 3.8 J/m(2)), reduced nucleotide excision repair, reduced expression of XPD mRNA and an undetectable level of XPD protein. Mutational analysis of the XPD gene in XP2GO revealed two different mutations: a common p.Arg683Trp amino acid change (c.2047C>T) known to be associated with XP and a novel frameshift mutation c.2009delG (p.Gly670Alafs*39). The latter mutation potentially behaves as a null allele. While not preventing neurological degeneration, early diagnosis and rigorous sun protection can result in minimal skin disease without cancer in XP patients.

Implementing arthritis clinical practice guidelines in primary care.

BACKGROUND: Multi-faceted interventions are among the strongest methods for changing provider behavior. AIMS: This paper reports the design, implementation and process evaluation of an educational program to disseminate clinical practice guidelines (CPGs) on the management of rheumatoid arthritis (RA) and osteoarthritis (OA) in primary care. METHODS: Organizations were invited to participate in inter-professional workshops on OA and RA followed by six months of activities to support the delivery of care in the community. Confidence in ability to manage arthritis was assessed at baseline using a 10 point numerical rating scale. Qualitative assessments were done immediately and 3-12 months post workshop. RESULTS: 646 multidisciplinary providers from 216 organizations attended one of 30 workshops. Providers (n = 584) reported moderate confidence in managing arthritis: family physicians: mean: SD = 7.46(1.42), n = 145; nurse practitioners: 6.10(1.84), n = 73; other health care professionals: 5.23(2.83), n = 389. Participants identified team learning, the opportunity to network and the involvement of trained patient educators as strong features of the workshops. At follow-up, participants indicated the greatest impact of the program was on collaborative care (83%) and patient self-management (79%). CONCLUSIONS: Qualitative results suggest that inter-professional learning may be a successful strategy for improving the delivery of collaborative arthritis care and supporting patient self-management.

Integrated FISH, Karyotyping and aCGH Analyses for Effective Prenatal Diagnosis of Common Aneuploidies and Other Cytogenomic Abnormalities.

Current prenatal genetic evaluation showed a significantly increase in non-invasive screening and the reduction of invasive diagnostic procedures. To evaluate the diagnostic efficacy on detecting common aneuploidies, structural chromosomal rearrangements, and pathogenic copy number variants (pCNV), we performed a retrospective analysis on a case series initially analyzed by aneuvysion fluorescence in situ hybridization (FISH) and karyotyping then followed by array comparative genomic hybridization (aCGH). Of the 386 cases retrieved from the past decade, common aneuploidies were detected in 137 cases (35.5%), other chromosomal structural rearrangements were detected in four cases (1%), and pCNV were detected in five cases (1.3%). The relative frequencies for common aneuploidies suggested an under detection of sex chromosome aneuploidies. Approximately 9.5% of cases with common aneuploidies showed a mosaic pattern. Inconsistent results between FISH and karyotyping were noted in cases with pseudo-mosaicism introduced by culture artifact or variable cellular proliferation from cells with mosaic karyotypic complements under in vitro cell culture. Based on findings from this case series, cell-based FISH and karyotyping should be performed to detect common aneuploidies, structural chromosomal abnormalities, and mosaic pattern. DNA-based aCGH and reflex FISH should be performed to detect and confirm genomic imbalances and pCNV. Practice points to ensure the diagnostic accuracy and efficacy were summarized.

Persistence of repair proteins at unrepaired DNA damage distinguishes diseases with ERCC2 (XPD) mutations: cancer-prone xeroderma pigmentosum vs. non-cancer-prone trichothiodystrophy.

Patients with xeroderma pigmentosum (XP) have a 1,000-fold increase in ultraviolet (UV)-induced skin cancers while trichothiodystrophy (TTD) patients, despite mutations in the same genes, ERCC2 (XPD) or ERCC3 (XPB), are cancer-free. Unlike XP cells, TTD cells have a nearly normal rate of removal of UV-induced 6-4 photoproducts (6-4PP) in their DNA and low levels of the basal transcription factor, TFIIH. We examined seven XP, TTD, and XP/TTD complex patients and identified mutations in the XPD gene. We discovered large differences in nucleotide excision repair (NER) protein recruitment to sites of localized UV damage in TTD cells compared to XP or normal cells. XPC protein was rapidly localized in all cells. XPC was redistributed in TTD, and normal cells by 3 hr postirradiation, but remained localized in XP cells at 24-hr postirradiation. In XP cells recruitment of other NER proteins (XPB, XPD, XPG, XPA, and XPF) was also delayed and persisted at 24 hr (p<0.001). In TTD cells with defects in the XPD, XPB, or GTF2H5 (TTDA) genes, in contrast, recruitment of these NER proteins was reduced compared to normals at early time points (p<0.001) and remained low at 24 hr postirradiation. These data indicate that in XP persistence of NER proteins at sites of unrepaired DNA damage is associated with greatly increased skin cancer risk possibly by blockage of translesion DNA synthesis. In contrast, in TTD, low levels of unstable TFIIH proteins do not accumulate at sites of unrepaired photoproducts and may permit normal translesion DNA synthesis without increased skin cancer.

Influence of XPB helicase on recruitment and redistribution of nucleotide excision repair proteins at sites of UV-induced DNA damage.

The XPB DNA helicase, a subunit of the basal transcription factor TFIIH, is also involved in nucleotide excision repair (NER). We examined recruitment of NER proteins in XP-B cells from patients with mild or severe xeroderma pigmentosum (XP) having different XPB mutations using local UV-irradiation through filters with 5 microm pores combined with fluorescent antibody labeling. XPC was rapidly recruited to UV damage sites containing DNA photoproducts (cyclobutane pyrimidine dimers, CPD) in all the XP-B and normal cells, thus reflecting its role in damage recognition prior to the function of XPB. Cells from the mild XP-B patients, with a missense mutation, showed delayed recruitment of all NER proteins except XPC to UV damage sites, demonstrating that this mutation impaired localization of these proteins. Surprisingly, in cells from severely affected patients, with a C-terminal XPB mutation, XPG and XPA proteins were normally recruited to UV damage sites demonstrating that this mutation permits recruitment of XPG and XPA. In marked contrast, in all the XP-B cells recruitment of XPF was absent immediately after UV and was delayed by 0.5 and 3 h in cells from the mild and severely affected XP patients, respectively. Redistribution of NER proteins was nearly complete in normal cells by 3 h but by 24 h redistribution was only partially present in cells from mild patients and virtually absent in cells from the severely affected patients. Ineffectual repair of UV-induced photoproducts resulting from delayed recruitment and impaired redistribution of NER proteins may contribute to the markedly increased frequency of skin cancer in XP patients.

The Genomic Health of Human Pluripotent Stem Cells: Genomic Instability and the Consequences on Nuclear Organization.

Human pluripotent stem cells (hPSCs) are increasingly used for cell-based regenerative therapies worldwide, with embryonic and induced pluripotent stem cells as potential treatments for debilitating and chronic conditions, such as age-related macular degeneration, Parkinson's disease, spinal cord injuries, and type 1 diabetes. However, with the level of genomic anomalies stem cells generate in culture, their safety may be in question. Specifically, hPSCs frequently acquire chromosomal abnormalities, often with gains or losses of whole chromosomes. This review discusses how important it is to efficiently and sensitively detect hPSC aneuploidies, to understand how these aneuploidies arise, consider the consequences for the cell, and indeed the individual to whom aneuploid cells may be administered.

Heterogeneity of dimer excision in young and senescent human dermal fibroblasts.

We have examined the relationship between nucleotide excision of the main UV-induced photoproduct, the cyclobutane pyrimidine dimer and in vitro cellular senescence. An in situ semiquantitative immunocytochemical assay has demonstrated that, following a UV-C dose of 15 J m-2, young human dermal fibroblasts maintained in a high level of serum are more efficient than senescent fibroblasts in the removal of dimers. However, in G0-arrested cultures (serum-starved), young fibroblasts are compromised in their ability to remove dimers and are significantly less efficient than senescent cells in this process. Supplementation of the culture medium with 0.1 mm deoxyribonucleosides enhances the removal of dimers in both young and senescent fibroblasts in proliferating or serum-starved cells. These data indicate that overall there is a modest but significant reduction in nucleotide excision of dimer photoproducts in cells as they age in vitro. In addition, G0-arrested young cells exhibit reduced removal of dimers, although this can be complemented by deoxyribonucleoside addition. In addition, this in situ assay has revealed heterogeneity in both susceptibility to UV-C-induced damage and excision. Overall, we provide evidence of reduced UV-induced damage excision in senescent compared with young fibroblasts, and demonstrate modulation of these processes in young and senescent cells under specific growth conditions.

Perceived parental approval of drinking and its impact on problem drinking behaviors among first-year college students.

There is a paucity of research investigating the impact that parents may have on college drinking. In this study, the authors investigated the relationship between students' perceptions of parent approval of drinking and problem drinking occurrence. They conducted a Web-based survey of 265 first-year students living on campus during their second semester. The authors used logistic regression to examine the relationship between students' perceptions of their mothers' and fathers' attitudes toward their drinking, their mothers' and fathers' drinking habits, and problem drinking since they had begun college. Sixty-nine percent of respondents reported experiencing at least 1 drinking problem. Over one third of students perceived that their parents would approve of them drinking occasionally. Students perceiving more parental approval for their drinking were more likely to report at least 1 drinking problem. Student perceptions of parental approval of drinking warrant further investigation as a potentially mutable correlate of problem drinking.