Emotional intelligence and coping strategies as determinants of quality of life in depressed patient-caregiver dyads: An actor-partner interdependence analysis.

OBJECTIVE: Patients with major depressive disorder (MDD) and their natural caregivers experience major lifestyle difficulties. Little is known concerning dyadic (i.e., patient and natural caregiver) characteristics' impact on quality of life. In a sample of depressed patient-caregiver dyads, we examined quality of life (QoL) levels compared with the general population and whether QoL is influenced by emotional intelligence (EI) and coping strategies using the actor-partner interdependence model (APIM). METHODS: This cross-sectional study involved 79 patient-caregiver dyads. The self-reported data, completed by patients and their primary caregivers, included QoL (SF-36), EI (TEIQue-SF) and coping strategies (BriefCope). The QoL of patients and caregivers was compared with 158 French age-sex-matched healthy controls. The dyadic interactions were analyzed using structural equation modeling. RESULTS: Patients and their caregivers experienced lower QoL levels than French age-sex-matched controls. The EI findings showed actor (degree to which the person's EI was associated with his/her own QoL) and partner (degree to which the person's EI was associated with QoL of the other member of the dyad) effects for patients and caregivers. The coping strategies (i.e., problem solving, positive thinking, avoidance and social support) revealed only actor effects. CONCLUSION: QoL is seriously impaired in depressed patients and their primary caregivers and is associated with EI and coping strategies. Targeted interventions focusing on EI and coping strategies could be offered to improve QoL in dyads.

Safety, tolerability, pharmacokinetics, and antiviral activity of GSK2336805, an inhibitor of hepatitis C virus (HCV) NS5A, in healthy subjects and subjects chronically infected with HCV genotype 1.

GSK2336805 is an orally bioavailable hepatitis C virus (HCV) inhibitor working through an NS5A-mediated mechanism. This first-time-in-human study was conducted to assess the safety, tolerability, pharmacokinetics, metabolism, and efficacy of GSK2336805 in healthy subjects and subjects infected with HCV genotype 1. We performed a three-part, randomized, double-blind, placebo-controlled study in 46 healthy subjects and 23 HCV-infected subjects. After an overnight fast, healthy subjects received GSK2336805 as 10 mg, 30 mg, 30 mg plus food, and 60 mg in a single dose and 10 mg (7 days), 30 mg (7 days), and 75 mg (14 days) in a once-daily multiple dose. Subjects with HCV received GSK2336805 as a 1- to 120-mg single dose. In subjects with HCV, reductions in HCV RNA were observed within 4 h and a single dose of GSK2336805 of ≥10 mg resulted in a statistically significant ≥2-log reduction in HCV RNA compared with placebo at 24 h postdose. GSK2336805 was readily absorbed in all subjects, and the half-life (t1/2) was suitable for once-daily dosing. Administration of GSK2336805 with food had no effect on plasma GSK2336805 exposure; however, absorption was delayed, with a median tmax (time to maximum concentration of drug in serum) of 4.5 versus 2.0 h. Twenty subjects who received GSK2336805 experienced mild to moderate adverse events; none were serious. GSK2336805 was well tolerated and exhibited rapid, significant antiviral activity after a single dose in HCV-infected subjects. These results support the conduct of further studies evaluating GSK2336805 administered once daily for longer durations in combination with peginterferon, ribavirin, and other direct-acting antivirals. (This study has been registered at ClinicalTrials.gov under registration no. NCT01277692.).

Responsiveness of human monocyte-derived dendritic cells to thimerosal and mercury derivatives.

Several cases of skin sensitization have been reported following the application of thimerosal, which is composed of ethyl mercury and thiosalicylic acid (TSA). However, few in vitro studies have been carried out on human dendritic cells (DCs) which play an essential role in the initiation of allergic contact dermatitis. The aim of the present study was to identify the effect of thimerosal and other mercury compounds on human DCs. To address this purpose, DCs derived from monocytes (mono-DCs) were used. Data show that thimerosal and mercury derivatives induced DC activation, as monitored by CD86 and HLA-DR overexpression associated with the secretion of tumor necrosis factor alpha and interleukin 8, similarly to lipopolysaccharide and the sensitizers, 1-chloro-2,4-dinitrobenzene (DNCB) and nickel sulfate, which were used as positive controls. In contrast, TSA, the non-mercury part of thimerosal, as well as dichloronitrobenzene, a DNCB negative control, and the irritant, sodium dodecyl sulfate, had no effect. Moreover, oxidative stress, monitored by ROS induction and depolarization of the mitochondrial membrane potential, was induced by thimerosal and mercury compounds, as well as DNCB, in comparison with hydrogen peroxide, used as a positive control. The role of thiol oxidation in the initiation of mono-DC activation was confirmed by a pre-treatment with N-acetyl-l-cysteine which strongly decreased chemical-induced CD86 overexpression. These data are in agreement with several clinical observations of the high relevance of thimerosal in patch-test reactions and prove that human mono-DCs are useful in vitro tools for determining the allergenic potency of chemicals.

Modulation of O6-methylguanine-DNA methyltransferase in rat and hamster liver after treatment with dimethylnitrosamine.

Distinct species differences exist between BDIV rats and Syrian Golden hamsters in the repair of methylated DNA lesions, after single exposures to dimethylnitrosamine (DMN). The promutagenic lesions O6-methylguanine (O6-MeG) and O4-methylthymidine were actively repaired in rat liver; in contrast, in hamster liver the levels of O6-MeG remained relatively stable while O4-methylthymidine levels were reduced. Species differences in the levels of two enzymes involved in the repair of DNA alkylation damage were also noted. An increase in the methylpurine-DNA glycosylase levels was seen in both species following DMN exposure; however, significant species differences in the inactivation and subsequent time course of recovery of the "suicide protein" O6-MeG-DNA methyltransferase were observed. In the rat a rapid recovery of activity began within 24 h of DMN exposure (20 mg/kg) and an approximately 3-fold induction in enzyme levels was observed at 96 h. In hamster liver, in which the constitutive level of expression of this enzyme is similar, no activity was detectable up to 96 h after treatment (25 mg/kg DMN). Only in animals in the lowest treatment group (2.5 mg/kg DMN) was a significant recovery seen, 264 h after treatment. The data presented suggest that the schedule of DMN treatment, in particular the time between doses of the carcinogen and the regeneration of the O6-MeG-DNA methyltransferase, would evoke different carcinogenic responses in hamster and rat liver following chronic exposure to alkylating agents.

Ras-transfection up-regulated HaCaT cell migration: inhibition by Marimastat.

Cell migration is an essential process in physiological and pathological conditions such as wound healing and tumor invasion. This phenomenon involves cell adhesion on the extracellular matrix mediated by integrins, and cell detachment promoted in part by metalloproteinases (MMPs). In the present study, the migration of two HaCaT-ras clones (metastatic or not), was compared with HaCaT cells, and normal human primary cultured keratinocytes. Using colloidal gold migration assay, the migration index on type I and type IV collagen was similar for primary cultured keratinocytes and HaCaT, whereas it was markedly higher for the HaCaT-ras clones. High motility of ras-transfected cells was confirmed from an in vitro wound healing assay. It was not correlated with changes in integrin expression or related to a different adhesion on extracellular matrix. The Marismastat (BB-2516), a MMP inhibitor, inhibited in a dose-dependent effect the migration in both assays, demonstrating the important role of MMPs in the migration process. Under our experimental conditions, MMP-1 activity was not detected in HaCaT and MMP-9 activity was secreted by these cells only after their stimulation by EGF. Here, MMP-2 was the major gelatinolytic activity secreted by all the cells and its secretion was markedly higher for HaCaT-nis clones compared with HaCaT. In addition, Western blotting results confirmed a higher expression of MMP-2 associated with a lower expression of TIMP-2 in HaCaT-ras compared with HaCaT. These results suggest that Ha-ras oncogene could be a stimulating factor of migration and might modified the balance between MMP-2 and TIMP-2 in keratinocyte cell lines.

Comparative studies on the secretion and activation of MMPs in two reconstructed human skin models using HaCaT- and HaCaT-ras-transfected cell lines.

Matrix metalloproteinases play an important role in tissue regeneration, wound healing and tumor invasion. Our previous studies have shown a higher motility of HaCaT-ras-transfected cells compared with HaCaT or normal human keratinocytes (NHK) in correlation with a higher secretion of MMP-2 (72 kDa) or MMP-9 (92 kDa), according to the medium used for cell cultures. Presently, the expression and activity of MMPs were investigated in two reconstructed skin models, using a dead de-epidermized dermis (DED) or a dermal substitute including living fibroblasts. In all experiments, MMP-9 was essentially secreted by NHK and to a greater extent by HaCaT cells. Its active form (86 kDa) was only detected in both reconstructed skin models according to keratinocyte differentiation. MMP-2 was mainly secreted by living fibroblasts included in the dermal substitute skin model. In this case, its activation was up-regulated when HaCaT cell lines were seeded onto the dermal substitute according to their culture at air/liquid interface as shown for MMP-9. The collagenase MMP-1 and stromelysin-1 (MMP-3), susceptible to activate pro-MMP-2 and -9, respectively, were detected in their inactive form by ELISA. MMP-1 was expressed in both models but MMP-3 required the presence of living fibroblasts. Their activities were not detected using specific fluorogenic substrates. In the skin equivalent model using HaCaT, the extensive secretion and activation of MMP-2 and MMP-9 could explain the defect observed in basal membrane reconstruction, suggesting a direct interaction of HaCaT with fibroblasts.

Visualization of von Willebrand factor multimers by immunoenzymatic stain using avidin-biotin peroxidase complex.

A technique for the detection of von Willebrand factor multimers separated by discontinuous SDS agarose electrophoresis has been developed using non-radioactive compounds. The multimeric patterns were visualized by monospecific anti-human vWF:Ag followed by incubation with biotinylated antibody. After addition of avidin-biotin-peroxidase complex, the peroxidase activity was detected by 4-chloro-1-naphthol, giving sharp bands with a clear background. By this method, the differences of vWF:Ag multimers could be easily observed between normal plasma and the plasmas from variant type vWD (IIA, IIB, platelet-type). Large and intermediate multimers were absent in the plasma with vWD type IIA, while only large multimers were absent in the plasma with vWD IIB and platelet-type. The absence of large multimers was also observed in two commercial FVIII preparations having the ratio of vWF/vWF:Ag 0.18 and 0.63. The preparation with the ratio of 0.63 showed the presence of larger intermediate multimers. Electrophoresis in SDS 1.5% agarose gel revealed triplet structure of each small multimer, and a relative increase of the smallest subband was observed in vWD IIA plasma, platelet-type vWD plasma and commercial FVIII preparations. The procedures described are easy and safe to perform and are useful for screening or classifying cases with vWD in general laboratories.

An ultrasensitive competitive binding assay for the detection of toxins affecting protein phosphatases.

An ultrasensitive assay is described for microcystin-LR and other substances (microcystins, nodularin, okadaic acid, calyculin A, tautomycin) which block the active site of protein phosphatases (PP) 1 and 2A. The assay is based on competition between the unknown sample and [125I]microcystin-YR for binding to the catalytic subunit of PP2A. The PP2A-bound [125I]microcystin-YR was stable (half-time of dissociation = 1.8 h), allowing non-bound [125I]microcystin-YR to be removed by Sephadex G-50 size-exclusion chromatography. Compared to current assays based on inhibition of protein phosphatase activity the present assay was more robust against interference (from fluoride, ATP, histone, and casein), and had an even better sensitivity. The detection limit was below 50 pM (2.5 fmol) for nodularin and microcystin-LR, and below 200 pM (10 fmol) for okadaic acid. The method was used successfully to detect extremely low concentrations of either microcystin or nodularin in drinking water or seawater, and okadaic acid in shellfish extract.

Sensitive detection of apoptogenic toxins in suspension cultures of rat and salmon hepatocytes.

A number of algal toxins were tested for the ability to induce apoptosis (regulated cell death) in primary hepatocytes from salmon and rat. The tested toxins included the liver targeting substances microcystin-LR and nodularin, substances associated with the diarrhetic shellfish poison complex (okadaic acid, dinophysistoxin-1 and pectenotoxin-1) and calyculin A. All toxins induced apoptosis in both salmon and rat hepatocytes in less than 2 h. The apoptotic changes were evident both by electron and light microscopy and were counteracted by the caspase inhibitor ZVAD-fmk and by the Ca2+/calmodulin dependent kinase II inhibitor KN-93. The salmon hepatocytes were 10-20-fold more sensitive to okadaic acid and dinophysistoxin-1 (EC50=20 nM) than rat hepatocytes and other mammalian cell lines tested. An assay was devised using hepatocyte apoptosis as parameter for detection of algal toxins. This assay was at least as sensitive as HPLC determination for okadaic acid in mussel extracts. It also detected algal toxins which do not inhibit protein phosphatases, like pectenotoxin-1. Subapoptotic concentrations of the toxins inhibited hepatocyte aggregation. Using this parameter, less than 200 pg okadaic acid could be detected. In conclusion, salmon hepatocytes in suspension culture provide a rapid and sensitive system for detection of a broad range of apoptogenic toxins.

The up-regulation of vascular endothelial growth factor in mutated Ha-ras HaCaT cell lines is reduced by a farnesyl transferase inhibitor.

The induction of tumor angiogenesis is mediated in particular by an increased production of VEGF. As ras oncogene is implicated in tumorigenesis, the inhibition of farnesyl transferase activity has recently been developed. The purpose of this study was to evaluate whether expression of mutated Ha-ras oncogene is associated with an altered expression of VEGF in an in vitro model of human skin carcinogenesis and to appreciate the effect of a new farnesyl transferase inhibitor on this VEGF expression. The amounts of VEGF secreted by an HaCaT cell line and two cell clones (metastatic or not) obtained after mutated c-Ha-ras transfection were compared. Our findings showed that the release of VEGF is greater for HaCaT-ras than for HaCaT cells and could be down-regulated using a protein farnesyl transferase inhibitor, in a reversible and dose-dependent manner. These results confirm that the Ha-ras oncogene can contribute to tumor development and progression of epidermal tumors through neoangiogenesis and that farnesyl transferase inhibitors as anticancer drugs may be efficient for the reduction of skin tumor growth.

Glucocorticoid receptor localization in human epidermal cells.

Glucocorticoids, which are widely used in therapy, exert their immunosuppressive actions through specific receptors. These receptors have been characterized in cultured human skin fibroblasts and keratinocytes, but their localization in vitro and in vivo has not been established. To determine the tissue and cellular distribution of glucocorticoid receptors (GR), two specific polyclonal rabbit anti-human GR antibodies were used to detect these receptors in skin biopsy specimens, in freshly isolated and cultured human epidermal cells and in keratinocyte cell lines. Immunoreactive GR were only faintly detected in normal and abnormal differentiated cells and as well as those in the stratum granulosum and corneocytes. These immunolocalization studies were confirmed by fluorescence cell sorter analysis of isolated basal and suprabasal keratinocytes. Immunoreactive GR were highly expressed in normal cultured human keratinocytes, Langerhans cells and several cell lines whereas they were less expressed in melanocytes. Based upon these results the main targets of glucocorticoids in the epidermis appear to be basal and Langerhans cells.

Expression of annexin I in freshly isolated human epidermal cells and in cultured keratinocytes.

Annexin I belongs to a newly characterized family of intracellular proteins involved in the regulation of the production of inflammatory lipid mediators such as prostaglandins and leucotrienes. Annexin I (named p35, lipocortin I or calpactin II) was initially described as a protein inducible by glucocorticoids. In the skin, the role of annexins has still not been elucidated. In the study reported here we investigated the expression of annexin I both in freshly isolated epidermal cells and in cultured keratinocytes using immunofluorescence, FACS analysis and immunoblotting techniques. Using epidermal cells freshly isolated from normal skin, annexin I was detected by double immunostaining mainly in basal and suprabasal keratinocytes. Langerhans cells isolated from Ficoll gradient were faintly stained compared with keratinocytes. Annexin I was also highly expressed in keratinocytes maintained in culture in a serum-free medium without hydrocortisone. By confocal microscopy, annexin I was shown to be mainly localized in the cytoplasm of the cells. The protein was characterized by Western blot and immunoprecipitation as a 35-kDa protein in freshly isolated epidermal cells and cultured keratinocytes. Results from in vivo studies confirmed the presence of annexin I in the basal and suprabasal layers of normal human skin with modified reactivity patterns in hyperproliferative lesions.

[Multidisciplinary approach as a model for detection and monitoring of psychiatric morbidity in patients treated with interferon and ribavirin]. / Abordaje multidisciplinar como modelo de detección y seguimiento de la moribilidad psiquiátrica en pacientes en tratamiento con interferón de la moribilidad psiquiátrica en pacientes en tratamiento con interferón y ribavirina.

PURPOSE: We aimed to describe the incidence of psychiatric disorders in a cohort of HCV infected patients treated with interferon and ribavirin, and their impact on treatment adherence and viral response rate (SVR). MATERIALS AND METHODS: Retrospective analysis of a cohort of HCV patients visited at an outpatient pharmacy service (OPS). We included all adult patients monoinfected with HCV who had initiated treatment in 2010. Monitoring of psychiatric disorders was assessed at weeks 0, 4, 12, 24, 48, and 72 through the self-administered questionnaires Hospital Anxiety and Depression Scale (HADS) and General Health Questionnaire (Goldberg).Adherence to treatment was assessed by counting of drug dispensations and patient reporting and drug exposure with the 80/80/80 rule. Virologic response was determined by the physician according to standard definitions. RESULTS: Among 76 included patients, 19 (25%) had a preexisting psychiatric disorder. The incidence of confirmed psychiatric disorders was 33% (n=25),with a peak of abnormal results in the tests by week 12. Overall, 43% of patients achieved an SVR. There were not significant differences between strict adherence and SVR in patients with or without medically confirmed disorders(96.0% vs 96,8%; p = NS) and SVR (39% vs 52%; p = NS], respectively. CONCLUSIONS: Psychiatric side effects had no effect on adherence to treatment nor on attainment of SVR. Multidisciplinary monitoring provided during the treatment of hepatitis C can contribute to early detection and management of psychiatric disorders and to improve integrated patient care.

Objetivo: Describir la experiencia recogida durante el programa multidisciplinar,y en particular describir la incidencia de los trastornos psiquiátricosen pacientes con hepatitis C crónica (HCC) durante el tratamiento coninterferón y ribavirina, y determinar la adherencia al tratamiento antiviraly la respuesta viral sobtenida (RVS).Material y métodos: Estudio observacional, descriptivo y retrospectivo realizadoa partir de los datos recogidos durante el programa de dispensaciónambulatoria de tratamiento antiviral.Se incluyó a todos los pacientes monoinfectados por el virus hepatitis C(VHC) que iniciaron tratamiento durante el 2010. El cribaje de lostrastornos psiquiátricos se realizó mediante el Hospital Anxiety-DepressionScale (HADS) y el General Health Questionnaire (Goldberg) las semanas 0,4, 12, 24, 48 y 72. La adherencia se evaluó mediante el recuento de dispensacionesy de la medicación sobrante del paciente y la exposición al fármacosegún la regla 80/80/80. La respuesta virológica se determinó por elmédico responsable de acuerdo a las definiciones estándar.Resultados: Se incluyeron 76 pacientes, 19 (25%) de los cuales teníanantecedentes psiquiátricos. La incidencia de trastornos psiquiátricos fue del33% (n = 25). El pico de resultados anormales en los test fue en la semana12. El 43% alcanzó RVS, sin diferencias entre ambos grupos (p > 0,05). Laadherencia (96,0% y 96,8%, p > 0,05) y RVS (39% y 52%, p > 0,05)fueron similares en ambos subgrupos con y sin trastornos.Conclusiones: Los trastornos psiquiátricos no tuvieron impacto en la adherenciay la RVS. El seguimiento multidisciplinar durante el tratamiento de la hepatitisC crónica (HCC) puede contribuir a la detección precoz y manejo de lostrastornos psiquiátricos y a mejorar la atención integral del paciente.

Cytoplasmic p27 is oncogenic and cooperates with Ras both in vivo and in vitro.

p27(Kip1) (p27) can have opposing roles during malignant transformation depending on cellular context: on one hand it functions as a tumor suppressor by inhibiting cyclin-cyclin-dependent kinase (CDK) activity in the nucleus and on the other it may adopt an oncogenic role that is less well understood. To gain further insight into the roles played by p27 during tumorigenesis, we compared the susceptibility with urethane-induced tumorigenesis of two p27 mouse models, p27(-/-) and p27(CK-) knockin, in which p27 cannot bind or inhibit cyclin-CDKs. In this K-Ras-driven tumorigenesis model, p27(CK-) mice had an increase in both tumor number and aggressiveness compared with p27(-/-), indicating a cooperation between p27(CK-) and activated Ras. In the lung, increased tumorigenesis was associated with cytoplasmic localization of p27(CK-) and bronchiolaveolar stem cell amplification. The ability of p27(CK-) to cooperate with other oncogenes was not universal. When c-Myc was used as a transforming agent, p27 status became irrelevant and c-Myc was equally potent in transforming p27(+/+), p27(-/-) and p27(CK-) cells. In fact, c-Myc induced the degradation of wild-type p27 via the Skp-Cullin-F-box (SCF)-Skp2 pathway. In contrast, p27(CK-) levels were not affected by c-Myc expression, as p27(CK-) is insensitive to Skp2-mediated degradation because of its inability to bind cyclin E/CDK2. However, in presence of c-Myc, p27(CK-) remained mostly nuclear, providing an explanation for its inability to cooperate with Myc during transformation. Thus, we propose that the p27(CK-) protein needs to be localized in the cytoplasm in order to function as an oncogene, otherwise it just behaves similar to a null allele.

Annexin 1 regulation in human epidermal cells.

Annexin 1 (named p35, lipocortin I or calpactin II), initially described as a glucocorticoid induced protein, belongs to a new characterized family of intracellular proteins. In the skin, the role of annexins has still not been elucidated. In a previous study, we reported the localization of annexin 1 in both freshly isolated human epidermal cells and in cultured keratinocytes using immunofluorescence, FACS analysis and immunoblotting techniques. The protein was characterized by Western blot and immunoprecipitation as a 35 kDa protein. Results from in vivo studies confirmed the presence of annexin 1 in basal and suprabasal layers of normal human skin with modified reactivity patterns in hyperproliferative lesions. In the present study, the role of glucocorticoids in annexin 1 regulation was investigated in epidermal cells by Western blot and immunoprecipation assays. In contrast to other studies, we found that glucocorticoid treatment of epidermal cells led to a decrease in annexin 1 content in the cytoplasm and the membranes of cells. As annexin 1 was not detected in the nucleus of cells, we conclude that there was a down regulation of annexin 1 after glucocorticoid treatments rather than a translocation of the protein to the nucleus. Despite the absence of the signal peptide sequence necessary for protein secretion, annexin 1 was released in the keratinocyte culture medium. We found that the protein was secreted only in low Ca2+ medium (0.15 mM), this process required an active metabolism.

MultiFun, a multifunctional classification scheme for Escherichia coli K-12 gene products.

An enriched classification system for cellular functions of gene products of Escherichia coli K-12 was developed based on the initial classification by Riley. In the new classification scheme, MultiFun, cellular functions are divided into 10 major categories: Metabolism, Information Transfer, Regulation, Transport, Cell Processes, Cell Structure, Location, Extra-chromosomal Origin, DNA Site, and Cryptic Gene. These major categories are further sub-divided into a hierarchical scheme. Two thousand nine hundred twenty-two gene products of E. coli K-12 were assigned to one or more functions depending on the role they play in the cell. Functional assignments were made to 66% of E. coli gene products, ranging from 1 to 16 assignments per gene product. The expansion of cellular function categories and the assignment to more than one category (multifunction) provides a more complete description of the gene products and their roles and hence better reflects the functional complexity of organisms. We believe this classification system will be useful in the field of genome analysis, both for annotation purposes and for comparative studies. The functional classification scheme and the cellular function assignments made to E. coli gene products can be accessed from the web at the databases GenProtEC (http://genprotec.mbl.edu) and EcoCyc (http://www.ecocyc.org).

Interim report on genomics of Escherichia coli.

We present a summary of recent progress in understanding Escherichia coli K-12 gene and protein functions. New information has come both from classical biological experimentation and from using the analytical tools of functional genomics. The content of the E. coli genome can clearly be seen to contain elements acquired by horizontal transfer. Nevertheless, there is probably a large, stable core of >3500 genes that are shared among all E. coli strains. The gene-enzyme relationship is examined, and, in many cases, it exhibits complexity beyond a simple one-to-one relationship. Also, the E. coli genome can now be seen to contain many multiple enzymes that carry out the same or closely similar reactions. Some are similar in sequence and may share common ancestry; some are not. We discuss the concept of a minimal genome as being variable among organisms and obligatorily linked to their life styles and defined environmental conditions. We also address classification of functions of gene products and avenues of insight into the history of protein evolution.

Endogenous ADP-ribosylation of proteins in Mycobacterium smegmatis.

Endogenous ADP-ribosylation of two proteins with molecular weights of 30,000 (30K) and 80,000 (80K) was detected in cell extracts of Mycobacterium smegmatis. Modification of these proteins was enzymatic. The ADP-ribose bound to 30K was removed by HgCl2 but not by NH2OH, suggesting the modification of a cysteine residue. The ADP-ribose bound to 80K was not removed by either HgCl2 or NH2OH, which is consistent with the modification of an asparagine residue. ADP-ribosylation of 80K appeared to be reversible.

Macromolecular and histological studies of new tissue formation in velour vascular prostheses.

The nature and characteristics of the tissue which develops on the inner surfaces of vascular arterial prostheses have been investigated by means of histological and biochemical criteria. Velour prosthetic tubes were implanted as aortic segmental replacements in the dog. On the 60th postoperative day, a neointimal layer of collagen covered with flattened endothelial-like cells was noted. However, despite this morphological evidence the microsomic and cytosolic enzymes implicated in the biosynthesis of glycosamino-glycuronoglycans were significantly modified in comparison with the normal aortic wall. The marked decrease in enzymes corresponding to the initiation of the glucidic linkages suggests that the biosynthesis of the macromolecular components responsible for the normal blood vaessel interfact was impaired in these newly developed tissues. Therefore, it is suggested that this newly developed tissue cannot be considered as a true vascular endothelium.

Detection in human cells of alkylated macromolecules attributable to exposure to nitrosamines.

Various methods for detecting DNA alkylation adducts are described briefly, with emphasis on immunoassays using antibodies against O6-methyldeoxyguanosine (O6-medGua), O4-methylthymidine (O4-meThy) and 7-methyldeoxyguanosine (7-medGua). The application of these methods to epidemiological studies is discussed, and results obtained so far on the presence of DNA alkylation adducts in human tissues are presented.