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Biomedical subjects

M Goldberg

Publications and source records attributed to M Goldberg.

At least 55 records · Page 3Linked to original sources

[Causes of death in a cohort of EDF-GDF employees: comparison between occupational medicine and official statistics data].

BACKGROUND: In an epidemiological study, medical causes of death may be obtained from different sources. In a study on French gas and electricity company (EDF-GDF) workers, they were obtained from the national INSERM database. Additionally, the causes collected by the EDF-GDF occupational physicians were available for a subset of 1,330 deaths, which occurred between 1989 and 1994. The data from the two sources were compared with each other, in order to assess whether they were globally equivalent, and the potential impact of their differences on the results of epidemiological analyses. METHODS: Concordance rates between causes of death in the INSERM and EDF-GDF physicians databases were calculated according to the International Classification of Diseases (ICD) ninth revision codes and for various causes groups. Causes of death records were also examined in order to clarify the observed divergences. SMRs were computed in order to evaluate the consequences of using each database in epidemiological analyses. Finally, some SMRs were computed with the two sources and compared with each other. RESULTS: INSERM and EDF-GDF physicians causes belonged to the same causes group in 81% of cases, but the exact cause was different for more than half of them. The concordance rate was high for the deaths by AIDS and by cancer, and low for deaths by respiratory system and digestive system diseases. More causes of death were coded as "unknown" in EDF-GDF physicians data than in INSERM data. The SMRs varied widely depending on whether the INSERM or EDF-GDF physicians causes of death databases were used. CONCLUSIONS: Causes of death recorded in the INSERM and EDF-GDF physicians databases are very different. Therefore, using the national mortality rates computed by INSERM with the EDF-GDF physicians causes of death to calculate SMRs is not valid, and it is observed that they may be very different from those computed with INSERM data. In a general way, it should be better to use the INSERM database, which is a common source, in order to generate results comparable with other studies. However, this database has its own limitations, and it may be better, in particular situations and for internal analyses, to use another source if it seems to be a better one.

Acquired Immunodeficiency Syndrome↗

Gastrostomy-site tumor recurrence is not always fatal.

Percutaneous gastrostomy (PEG) site tumor seeding is a rare occurrence with fewer than 30 reported cases. Reported treatment ranges from observation to wide excision with unanimously poor outcome. We report the first published case of a long-term survivor after resection of a PEG site recurrence and review our treatment approach.

Antineoplastic Combined Chemotherapy Protocols↗

Ultrastructure of forming enamel in mouse bearing a transgene that disrupts the amelogenin self-assembly domains.

The mouse X-chromosomal amelogenin gene promoter was used to drive the expression of mutated amelogenin proteins in vivo. Two different transgenic mouse lines based on deletions to either the amino-terminal (A-domain deletions) or to the carboxyl-region (B-domain deletions) were bred. In the molars of newborn A-domain deleted transgenic mice the formation of the initial layer of aprismatic enamel was delayed. There were severe structural alterations in the enamel of incisors of newborn mice bearing the A-domain deletion which were not apparent in animals bearing the B-domain deletion. In the A-domain-deleted animals, stippled material accumulated throughout the entire thickness of the forming enamel apparently causing a disruption of the normal rod-to-inter-rod relationship. This stippled material was likened to and interpreted as being groupings of amelogenin nanospheres. In the B-domain-deleted animals the stippled material was detected only in minute defects of the forming enamel. These data suggest significant differences in nanosphere assembly properties for animals bearing either the A-domain or the B-domain-deleted transgene. The present in vivo experimental approach suggests that at early stages of enamel formation, the A-domain plays a greater role than does the B-domain in amelogenin self-assembly, and consequently in enamel architecture and structure.

Amelogenesis↗

[Mineralization of the dental pulp: contributions of tissue engineering to tomorrow's therapeutics in odontology].

When bioactive molecules such as bone sialoprotein (BSP), bone morphogenetic protein-7 (BMP-7, also termed OP-1) and chondrogenic Inducing Agents (CIA, A+4 and A-4) were implanted in the pulp of the first upper molars, mineralizations were induced. They were either limited to the formation of a reparative dentinal bridge closing the pulpal wound (CIA A+4), or filled the mesial part of the coronal pulp (BSP), or filled totally the pulp located in the root canal (BMP-7 and CIA A-4). Consequently, these molecules may change in the next future the every day practice in dentistry.

Animals↗

Factors associated with self-reporting of chronic health problems in the French GAZEL cohort.

The objective of this study was to examine factors associated with self-reporting of chronic health problems. The self-reports were obtained from a questionnaire sent by mail to the French GAZEL cohort, composed of workers of a French company. The disorders reported in the questionnaire were compared with diagnoses from the sick-leave database of the company. Associations between self-reporting and characteristics were studied by multiple logistic regression analyses. Three types of characteristics were analyzed: individual, methodological and disorder-related (i.e., prevalence of chronic disorders in the general population, probable disability and probable life risk scores). In 1992, the cohort consisted of 16,534 subjects aged 38 to 53 years. The reporting rate (number of self-reports in the questionnaire divided by number of records in the sick-leave database for the disorder considered) varied from 8.9% to 100%. Self-reporting was associated with individual characteristics (gender, family status, place of residence, annual number of sick days and sick leaves), disorder-related characteristics (probable disability, prevalence) and methodological characteristics (precision of the formulation, delay between the last sick-day and the patient report). By body system, the characteristics associated with self-reporting varied greatly but the annual number of sick days, probable disability and precision of formulation were the variables which remained most often in the models. These characteristics should be particularly taken into consideration in the interpretation of epidemiological results based on self-reporting.

Adult↗

Osteogenic proteins (bone sialoprotein and bone morphogenetic protein-7) and dental pulp mineralization.

Bone sialoprotein (BSP) cross-linked to collagen/gelatin was implanted in the pulp of rat's upper molars. Comparison was carried out with a sham group (non implanted), with a group of rats receiving the carrier alone, and a group of molars where the perforated pulps were capped with calcium hydroxide. The cavities were occluded with a glass-ionomer cement (GIC). After 8, 14 and 30 days respectively the rats were killed by intracardiac perfusion of the fixative and processed for light microscopy. Dentin and predentin debris pushed into the pulp during the preparation enhanced self-repair processes, with large pulp remnants. The carrier alone induced slight inflammation, and calcium hydroxide the formation of a reparative dentin bridge. BSP stimulated the recruitment of cells which produced an homogeneous atubular dentin-like structure, filling after one month the mesial third of the crown pulp. Osteogenic protein (OP-1) used in the same experimental conditions induced the formation of osteodentin in the coronal pulp and the radicular part of the pulp was totally filled by a mineralized material. The differences reported here suggest two possible different therapeutic approaches with the two osteogenic proteins, BSP inducing pulp mineralization in the crown part, and OP-1 occluding the root part of the pulp.

Journal Article↗

The dentino-enamel junction revisited.

The dentino-enamel junction is not an simple inert interface between two mineralized structures. A less simplistic view suggests that the dentino-enamel junctional complex should also include the inner aprismatic enamel and the mantle dentin. At early stages of enamel formation, fibroblast growth factor (FGF)-2 is stored in and released from the inner aprismatic enamel, possibly under the control of matrix metalloproteinase (MMP)-3. The concentration peak for MMP-2 and -9 observed in the mantle dentin coincided with a very low labeling for TIMP-1 and -2, favoring the cross-talk between mineralizing epithelial and connective structures, and as a consequence the translocation of enamel proteins toward odontoblasts and pulp cells, and vice versa, the translocation of dentin proteins toward secretory ameloblasts and cells of the enamel organ. Finally, in X-linked hypophosphatemic rickets, large interglobular spaces in the circumpulpal dentin were the major defect induced by the gene alteration, whereas the mantle dentin was constantly unaffected. Altogether, these data plead for the recognition of the dentino-enamel junctional complex as a specific entity bearing its own biological characteristics.

Aging↗

TEM observations on the ameloblast/enamel interface in the rat incisor.

The structure of rat incisor enamel is established at the topographically complex interface between secretory ameloblasts and forming enamel. The aim of this study was to gain additional information on this interface by sectioning parallel with the rows and the long axis of Tomes' processes and prisms. Rats were sacrificed and fixed by glutaraldehyde/paraformaldehyde perfusion. After dissection, demineralization and embedding transverse jaw/incisor segments were cut, reembedded, and reoriented. Sections were prepared for and observed in the transmission electron microscopy (TEM). The intraenamel part of Tomes' process was about 18 microns long. The forming prism occupied a longitudinally grooved invagination on its apical aspect. The parts of Tomes' process forming the side walls of the groove were attenuated and showed variation in extent and outline. Prism growth occurred over the whole grooved area. An estimation of Tomes' process secretory area in rat compared with data from humans suggests that there may be a relationship between secretory area and rate of prism formation. Prism crystals were oriented obliquely or parallel to the secretory surface of Tomes' process. At interprism growth sites matrix deposition was irregular and required some redistribution to conform to the pattern of interprism sheets.

Ameloblasts↗

Phospholipids in amelogenesis and dentinogenesis.

Phospholipids have been identified in enamel and dentin. Before demineralization, a group of phospholipids extracted by lipid solvents was associated with cell membranes and is therefore closely related to cell growth and intracellular regulations. After demineralization, a second group of phospholipids, associated with the extracellular matrix, was extracted; this group is probably linked to the mineralized phase. Using imidazole-osmium tetroxide fixation of rat incisors, we stained cellular unsaturated fatty acids, so that we could visualize the membrane domains, coated pits, and endocytic inclusions. Filipin, a probe for cholesterol, varied in density along the plasma membrane of secretory ameloblasts, and allowed us to visualize membrane remnants inside the forming enamel. With respect to phospholipids located in the extracellular matrix, the malachite-green-glutaraldehyde (MGA) method or iodoplatinate (IP) reaction retains and visualizes enamel and dentin phospholipids. In predentin, aggregates appearing as granules and filaments, or liposome-like structures, were located in the spaces between collagen fibrils. In dentin, organic envelopes coating the crystals, also named "crystal-ghost" structures, outlined groups of collagen fibrils. Histochemical data provided evidence that phospholipids are co-distributed or interact with proteoglycans. Radioautography after IP reaction established that [3H] choline was detected in dentin as early as 30 min after the intravenous injection of the labeled precursor, before any labeling was seen in odontoblasts and predentin. This suggests that blood-serum-labeled phospholipids pass between odontoblasts, cross the distal permeable junctional complex, and diffuse in dentin prior to any cellular uptake and phospholipid synthesis. Pharmacologically and genetically induced pathology also supports the suggestion that phospholipids play an important role in the formation and mineralization of dental tissues.

Ameloblasts↗

Ticks parasitizing dogs in northwestern Georgia.

From January 1998 through September 1999, 324 dogs in three northwestern Georgia counties were examined for ticks. Six species of ticks were recovered. The three most commonly collected ticks were the American dog tick, Dermacentor variabilis (Say) (310 male male, 352 female female; prevalence, 97%; mean intensity 2.1); the brown dog tick, Rhipicephalus sanguineus (Latreille) (118 male male, 119 female female, 38 nymphs; prevalence, 22%; mean intensity, 3.8); and the lone star tick, Amblyomma americanum (L.) (8 male male 26 female female, 2 nymphs; prevalence, 5%; mean intensity, 2.4). Other ticks recovered were Ixodes cookei Packard (3 female female); the Gulf Coast tick, Amblyomma maculatum Koch (2 female female); and the blacklegged tick, Ixodes scapularis Say (1 female). Another adult female specimen of I scapularis was recovered from a cat, further reinforcing that this medically important tick is present in northwestern Georgia.

Animals↗

Socioeconomic position, health, and possible explanations: a tale of two cohorts.

OBJECTIVES: We examined whether the social gradient for measures of morbidity is comparable in English and French public employees and investigated risk factors that may explain this gradient. METHODS: This longitudinal study of 2 occupational cohorts-5825 London civil servants and 6818 French office-based employees-used 2 health outcomes: long spells of sickness absence during a 4-year follow-up and self-reported health. RESULTS: Strong social gradients in health were observed in both cohorts. Health behaviors showed different relations with socioeconomic position in the 2 samples. Psychosocial work characteristics showed strong gradients in both cohorts. Cohort-specific significant risk factors explained between 12% and 56% of the gradient in sickness absence and self-reported health. CONCLUSIONS: Our cross-cultural comparison suggests that some common susceptibility may underlie the social gradient in health and disease, which explains why inequalities occur in cultures with different patterns of morbidity and mortality.

Adult↗

[Occupational exposure to wood dust. Health effects and exposure limit values].

This article presents a review of the health effects of occupational exposure to wood dusts and of the data that could be used for setting occupational exposure limits for this nuisance. The causal role of wood dust in the onset of sinonasal cancers is solidly established by numerous epidemiological studies, and the magnitude of the risk is particularly high for adenocarcinoma induced by exposure to hardwood dust. However, no current data allows to rule out the carcinogenic role of softwood dusts and, in the view of protecting the health of the workers, it does not seem relevant to distinguish these two types of wood. Various impairments of the lung function have been frequently associated with exposure to both 'allergenic' and 'non-allergenic' wood dusts and may occur at very low concentrations. According to the SUMER 94 and CAREX studies, about 200 000 workers are currently exposed to wood dusts in France (about 1% of the working population between 1990 and 1994). When taking into account full professional careers, the percentage of workers having been occupationally exposed can be estimated to be about 15% for men and 5% for women. Measurements performed in France between 1987 and 2000 show that exposure levels are high, about 50% of the samplings being over 1mg/m(3) (actual TWA in France). Although the studies present limits, particularly for the quantitative assessment of individual exposure levels, it seems that nonmalignant effects are susceptible to arise at the level of 1mg/m(3); a limit value of 0.5mg/m(3) would credibly allow to protect exposed workers from most of the risks of nonmalignant pulmonary effects. However, it is impossible to assure that this value will avoid the induction of sinonasal cancer, even if this level is certainly lower than the levels to which the cases of sinonasal cancers published in the literature were exposed.

Adenocarcinoma↗

The nucleoporin Nup153 is required for nuclear pore basket formation, nuclear pore complex anchoring and import of a subset of nuclear proteins.

The nuclear pore complex (NPC) is a large proteinaceous structure through which bidirectional transport of macromolecules across the nuclear envelope (NE) takes place. Nup153 is a peripheral NPC component that has been implicated in protein and RNP transport and in the interaction of NPCs with the nuclear lamina. Here, Nup153 is localized by immunogold electron microscopy to a position on the nuclear ring of the NPC. Nuclear reconstitution is used to investigate the role of Nup153 in nucleo- cytoplasmic transport and NPC architecture. NPCs assembled in the absence of Nup153 lacked several nuclear basket components, were unevenly distributed in the NE and, unlike wild-type NPCs, were mobile within the NE. Importin alpha/beta-mediated protein import into the nucleus was strongly reduced in the absence of Nup153, while transportin-mediated import was unaffected. This was due to a reduction in import complex translocation rather than to defective receptor recycling. Our results therefore reveal functions for Nup153 in NPC assembly, in anchoring NPCs within the NE and in mediating specific nuclear import events.

Animals↗

Socioeconomic, demographic, occupational, and health factors associated with participation in a long-term epidemiologic survey: a prospective study of the French GAZEL cohort and its target population.

The purpose of this paper is to examine personal and health factors, both at the beginning of the study and thereafter, associated with participation in the GAZEL cohort, set up in 1989 in a large French company. The authors used logistic regression to analyze the associations between participation and data available for both participants (n = 20,093) and nonparticipants (n = 24,829). Higher participation was associated with male sex, marriage, children, managerial status, and residence in particular regions. Among men, lower participation was associated with sick leave in the year before recruitment and afterwards. During follow-up, participation was negatively associated with several groups of diseases, especially those associated with alcohol consumption. The risk of upper respiratory and digestive tract and lung cancer during follow-up was higher among nonparticipants. The same phenomenon occurred among women, but less markedly, for cancers of the breast and genital organs. During follow-up, mortality among men was higher among nonparticipants, especially for alcohol-related diseases. The association among women was less strong. Among men, but not among women, diseases caused by alcohol, smoking, or dangerous behavior were the primary reason for the health differences observed between participants and nonparticipants. Overall, the most important determinants of participation were cultural factors and lifestyle behaviors.

Absenteeism↗

Immunoelectron microscopic visualization of pro- and secreted forms of decorin and biglycan in the predentin and during dentin formation in the rat incisor.

Using antibodies raised against the proform and fully processed (secreted) forms of the proteoglycans decorin and biglycan, combined with gold electron immunohistochemistry, we observed in the incisors of five Sprague-Dawley rats that the proforms were mostly located in the cell bodies of odontoblasts, with a presence reduced to one-third or one-fourth in the processes. Proforms, also present in the extracellular matrix, were uniformly distributed throughout predentin, with higher labeling for probiglycan than pro-decorin. Both were present in lesser amounts in metadentin and dentin. With respect to the secreted form, grain density was at a constant level for biglycan in predentin and dentin, whereas a gradient was detected for decorin, the grain density being increased three times in the distal predentin. Although decorin labeling was diminished in metadentin, staining in circumpulpal dentin was similar to that found in distal predentin. We have previously reported a reverse gradient for chondroitin sulfate/dermatan sulfate distribution. To reconcile these diverging data, our hypothesis is that enzymatic proteolytic cleavage may remove the glycosylated N-terminal-containing region, resulting in a non- proteoglycan form of the molecule. Although substantial differences in distribution were apparent between the two proteoglycans, increasing interactions between proteoglycans and collagen, facilitated by the cleavage and loss of the N-terminal glycosaminoglycan chain region in the distal predentin, may be a prerequisite for dentin mineralization.

Animals↗

Noradrenaline-induced increase in protein synthesis in adult rat cardiomyocytes: involvement of only alpha1A-adrenoceptors.

Adult rat ventricular cardiomyocytes contain alpha1A- and alpha1B-adrenoceptors (ARs, 20%:80%, assessed by [3H]prazosin binding). We studied which alpha1-AR subtype mediates noradrenaline (NA)-induced increase in rate of protein synthesis, and which signalling pathway is involved. NA (10-9-10-4 M) concentration-dependently increased inositol phosphate (IP) formation (pEC50-value=6.1+/-0.1, n=5) and protein synthesis (assessed as [3H]phenylalanine incorporation; pEC50-value=6.6+/-0.1, n=6). NA-induced IP-formation was partly inhibited by the alpha1B-AR antagonist chloroethylclonidine (CEC, 30 microM; 33+/-9% inhibition, n=5); following CEC-treatment the alpha1A-AR-selective 5-methyl-urapidil (5-MU) inhibited NA-induced IP-formation with a pKi-value of 9.2+/-0.2 (n=6); the alpha1D-AR-selective BMY 7378 was only a weak antagonist (pKi-value <7). NA-induced increase in protein synthesis was insensitive to CEC whereas 5-MU inhibited it with a pKi-value of 9.1+/-0.2 (n=6). NA (1 microM)-induced increase in protein synthesis was inhibited by the protein kinase C (PKC) inhibitor bisindolylmaleimide (IC50-value: 206 nM), the PI 3-kinase inhibitors wortmannin (IC50=3.4 nM) and LY 294002 (IC50=10 microM), and p70s6-kinase inhibitor rapamycin (IC50=123 pM) but not by the p38 MAP-kinase inhibitor SB 203580 (10 microM) or the MEK-inhibitor PD 98059 (25 microM). Moreover, 5-MU (30 nM) but not CEC inhibited NA-induced activation of p70s6-kinase. We conclude that, in adult rat cardiomyocytes, alpha1A- and alpha1B-AR mediate NA-induced IP-formation but only alpha1A-ARs mediate increase in protein synthesis. Alpha1A-AR-mediated increase in protein synthesis involves activation of a PKC, PI 3-kinase and p70s6-kinase but not of ERK- or p38 MAP-kinase.

Adrenergic alpha-1 Receptor Antagonists↗

Do cardiovascular risk factors in men depend on their spouses' occupational category?

OBJECTIVE: To analyse the relationships between major cardiovascular risk factors in French men and their spouses' occupational category (OC), taking their own OC into account. DESIGN: A large sample of volunteers working in the French National Electricity and Gas Company (GAZEL). As a check of the robustness, the same analysis was performed in a population-based survey (French multinational MONItoring of trends and determinants in CArdiovascular disease (MONICA) registers). SETTING: Any site of the company in France. Representative sample from the population of the three registers (Lille, Strasbourg, Toulouse). PARTICIPANTS: 9486 and 534 men respectively, in working activity, living in couple and aged 40 to 50 years. MAIN OUTCOME MEASURES: Self-reported arterial hypertension, diabetes, hypercholesterolemia, leisure time sedentary lifestyle, smoking status, body mass index (BMI) and alcohol consumption. RESULTS: In the GAZEL study, diabetes, smoking status, and alcohol consumption in men were associated with their own OC. In contrast, spouses' OC was independently associated with men's hypertension, hypercholesterolemia, sedentary lifestyle, and BMI: men whose spouses were unoccupied or workers have higher risk factors levels. In the MONICA study, the results were mostly comparable, at least for hypercholesterolemia, sedentary lifestyle, smoking status and alcohol consumption. CONCLUSION: Spouses' OC was independently associated with several cardiovascular risk factors in men. These results might indicate that socioeconomic status of the couple, and not only individual characteristics, should be taken into account for a better understanding of cardiovascular risk.

Adult↗