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Biomedical subjects

D N Stern

Publications and source records attributed to D N Stern.

At least 19 recordsLinked to original sources
PubMed1998

Non-interpretive mechanisms in psychoanalytic therapy. The 'something more' than interpretation. The Process of Change Study Group.

It is by now generally accepted that something more than interpretation is necessary to bring about therapeutic change. Using an approach based on recent studies of mother-infant interaction and non-linear dynamic systems and their relation to theories of mind, the authors propose that the something more resides in interactional intersubjective process that give rise to what they will call 'implicit relational knowing'. This relational procedural domain is intrapsychically distinct from the symbolic domain. In the analytic relationship it comprises intersubjective moments occurring between patient and analyst that can create new organisations in, or reorganise not only the relationship between the interactants, but more importantly the patient's implicit procedural knowledge, his ways of being with others. The distinct qualities and consequences of these moments (now moments, 'moments of meeting') are modelled and discussed in terms of a sequencing process that they call moving along. Conceptions of the shared implicit relationship, transference and countertransference are discussed within the parameters of this perspective, which is distinguished from other relational theories and self-psychology. In sum, powerful therapeutic action occurs within implicit relational knowledge. They propose that much of what is observed to be lasting therapeutic effect results from such changes in this intersubjective relational domain.

Countertransference↗
PubMed1995

Gene expression and phosphorylation of mouse osteopontin.

Osteopontin is expressed in many different cell types and has been proposed to play several functions. Distinct forms of the protein have been detected. Various tissues and cell lines from mouse, however, exhibit two classes of transcripts with different 5'-untranslated ends but with an identical coding region (exons II through VII). These transcripts do not arise from the alternative splicing of coding exons. These results suggest that posttranslational modifications of osteopontin, such as phosphorylation, are a major mechanism to generate different forms of the protein. Mouse osteopontin was expressed in E. coli and used as a model to study its phosphorylation.

Animals↗
PubMed1993

Comparison of rates of enamel synthesis in impeded and unimpeded rat incisors.

Periodic intubations of rats with solutions of fluoride (F) lead to the appearance of bands of disrupted pigmentation in continuously erupting incisors. Distances between fluorotic bands reflect time intervals between intubations. In this experiment, the periodicity of fluorotic banding was used for estimation of the rate of enamel synthesis in impeded and unimpeded rat incisors. Rats kept on a low-F diet and distilled water were intubated two or four times per week with 2 mg NaF/150 g body weight. In a group of rats, one of the mandibular incisors was cut at the gingival margin after two weeks, and intubations were continued for an additional two weeks. In another group of F-intubated rats, incisors were cut or notched at the gingival margin twice, six days apart. Control rats either received the same periodic F intubations or were maintained on the low-F diet without intubation. Measurements of spacing between fluorotic bands were identical in impeded and unimpeded teeth, even though the latter erupted at a faster rate. In an unimpeded mandibular incisors, there was a significant elongation of the secretory zone and a shortening of the pigmentation zone, resulting in reduced pigmentation intensity of the erupted portions of the teeth. The results show that the rate of enamel synthesis is independent of the eruption rate.

Amelogenesis↗
PubMed1992

Tubule formation and elemental detection in developing opossum enamel.

Most marsupials and some placental mammals possess enamel characterized by the presence of tubules, and the cellular origin of these structures has been the subject of a number of previous studies (See, for example, Lester, 1970; Azevedo and Goldberg, 1987). In the present report, tooth germs of the American opossum were examined to determine the structure and composition of enamel tubules during development and to analyze the enamel matrix relative to that of placental mammals with atubular enamel. For this purpose, tissues prepared by aqueous (decalcified and undecalcified) and anhydrous (undecalcified) methods were investigated by conventional transmission (TEM) and high voltage electron microscopy (HVEM), as well as by electron probe x-ray microanalysis (EPMA), selected-area electron diffraction (SAED), and electron spectroscopic imaging (ESI). Results indicate that most enamel tubules in the opossum begin as cytoplasmic remnants of Tomes' processes of ameloblasts. During development of the matrix, some of the tubules do not appear to be continuous throughout the prismatic layer. Sulfur is detectable around the lumen of the tubule in decalcified sections by EPMA and in and around the tubule by ESI. Calcium/phosphorus (Ca/P) molar ratios of the mineralizing matrix are generally higher than those found in enamel of other mammals and appear to decrease rather than increase with enamel maturation. The summary of data indicates the presence of sulfated glycoproteins or proteoglycans in this tissue, specifically around enamel tubules. Calcium and phosphorus are also present within the tubules, with the sulfated groups possibly binding calcium to prevent mineralization of the enamel tubules themselves.

Ameloblasts↗
PubMed1991

Disturbances of affect expression in failure-to-thrive.

Positive and negative affects were assessed in 28 6- to 36-month-old children with failure-to-thrive and 14 normally growing children in feeding and nonfeeding situations. The roles of malnutrition and severity of organic effects also were examined. Failure-to-thrive children expressed less positive affect in the feeding and nonfeeding situations and more negative affect in feeding than normally growing children. Among failure-to-thrive children, the presence of both acute and chronic malnutrition was associated with heightened negative affect during feeding, whereas the degree of organic contribution had no effect. These results, if replicated, may have implications for clinical assessment and are discussed in terms of current theories of failure-to-thrive.

Affective Symptoms↗
PubMed1989

Implications of research on infant development for psychodynamic theory and practice.

Recent research on infant development is reviewed to consider its implications for psychodynamic theory and practice. To address the question of the importance of early experiences for development, research on continuities and discontinuities in development, temperament, motivational systems in infancy, affect development and regulation, development of the sense of self, and infant-caregiver attachment are reviewed. Two major implications emerge, both emphasizing the need for more complexities in our conceptualizations. First, research on infant development underscores the importance of context in development and cautions about the limits of reductionistic thinking and theories. Second a major paradigmatic shift away from the fixation-regression model of psychopathology and development is indicated. A new model that better fits available data is proposed instead. In this continuous construction model, there is no need for regression, and ontogenetic origins of psychopathology are no longer necessarily tied to specific critical or sensitive periods in development. Implications for psychodynamic treatment are also described.

Humans↗
PubMed1989

Scanning electron microscopy of monkey secretory- and transitional-stage enamel organ cells.

This scanning electron microscope (SEM) study of secretory- and transitional-stage enamel organ cells of the permanent dentition of Macaca mulatta and Macaca arctoides was undertaken because the topography of these cells in primates has not been described in the literature. Comparison of our results with murine enamel organ morphology reported previously revealed not only many similarities, but also some significant differences. Tooth buds of the permanent dentition were routinely prepared for SEM. Murine secretory-stage ameloblasts have been described to be 65-70 microns long, with smooth lateral membranes, but those of monkeys were only 30-35 microns tall, with four different lateral plasma membrane configurations: smooth, filamentous, longitudinally ridged, and transversely ridged. The filamentous form was most common. Cells were seen with either transverse or longitudinal ridges in the basal half, and with filamentous ridges in the apical portion; this indicates modulation between these forms. Because of the extraordinary similarity between these lateral membrane modulations and those of rat incisor maturation ameloblasts, a comparable function is proposed--namely, that monkey secretory ameloblasts function, in part, in the resorption and mineralization of enamel matrix. There were several layers of rounded stratum intermedium cells basal to monkey secretory-stage ameloblasts, but only one layer of cuboidal stratum intermedium in rodents. The stellate reticulum cells of rats and monkeys appeared attenuated, with large extracellular spaces. There was little or no reduction in cell length of monkey transitional-stage ameloblasts. The position of the nuclear bulge differentiated transitional- from secretory-stage ameloblasts.(ABSTRACT TRUNCATED AT 250 WORDS)

Ameloblasts↗
PubMed1988

A scanning electron microscope study of monkey maturation-stage ameloblasts.

The maturation-stage enamel organs of Macaca arctoides and Macaca mulatta were examined in order to determine whether the cells were similar to those of the continuously erupting rat incisor. Tooth buds of the permanent dentition were fixed in formaldehyde-glutaraldehyde and post-fixed in OsO4. The enamel organs were separated from the enamel during dehydration, critical-point-dried, metal-coated, and examined in a scanning electron microscope. The results showed that there were few differences in the morphology of maturation-stage ameloblasts of these primates compared with those of other species reported in the literature. The apical plasma membranes were either smooth- or ruffle-ended, while the later membranes had maze, microvillous, or ridge configurations, also seen in rats, and an additional configuration of interdigitating bulbous extensions. The blood vessels of the papillary layer in monkeys were about 7 micron in diameter, considerably larger than those of the rat.

Ameloblasts↗
PubMed1988

Affect in the context of the infant's lived experience: some considerations.

Affect is considered in the context of the infant's lived-experience. It is considered as one of the attributes of experience, among many (cognition, perception, motive, action). Several different positions concerning the relative weight and role allotted to affect compared to other attributes are discussed along with the implications of each position for defining the infant's subjective, memorial and representational world.

Affect↗
PubMed1987

[Affective attunement: division of emotional states between mother and child by cross-modal exchange].

From a rigorous clinical methodology, the author describes an interaction of a particular pattern between mother and child, the behavior of attunement, which appears around 8 months. It is a matching, more than an imitation, that is cross-modal, each partner using a mode of expression different, unconsciously the most often. The reference for the match is the internal state and not the external behavioral act. Attunement is felt like an unbroken process in the time and leads to define a new quality of feeling, vitality. The quality of the relation of attunement determines probably the ulterior level of the inter-subjective relatedness of the ability to "be-with", to share.

Child Behavior↗