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Biomedical subjects

G H Pollock

Publications and source records attributed to G H Pollock.

At least 19 recordsLinked to original sources
PubMed1995

A 25.7 x 10(3) M(r) hydra metalloproteinase (HMP1), a member of the astacin family, localizes to the extracellular matrix of Hydra vulgaris in a head-specific manner and has a developmental function.

Hydra extracellular matrix (ECM) is composed of a number of components seen in vertebrate ECM such as laminin, type IV collagen, fibronectin, and heparan sulfate proteoglycan. A number of functional studies have shown that hydra ECM plays an important role in pattern formation and morphogenesis of this simple metazoan. The present study was designed to identify matrix degrading proteinases in hydra and determine their potential function in hydra morphogenesis. Using SDS-PAGE gelatin-zymography, five gelatinolytic bands were identified with relative molecular masses of 67 x 10(3), 51-58 x 10(3) (a triplet) and 25-29 x 10(3), respectively. Inhibition studies indicated that all of these gelatinases were metalloproteinases. Gelatin-zymography indicated that there was a differential distribution of these gelatinases along the longitudinal axis of hydra, with the 67 x 10(3) M(r) gelatinase being concentrated in the body column, while the 51-58 x 10(3) M(r) gelatinase triplet and the 25-29 x 10(3) M(r) gelatinase concentrated in the head region. Purification procedures were successfully developed for the 25-29 x 10(3) M(r) metalloproteinase which has been termed hydra metalloproteinase 1 (HMP1) and which appeared as a single band with a SDS-PAGE mobility of 25.7 x 10(3) M(r). The N-terminal sequence of purified HMP1 indicated that it has structural homology with metalloproteinases that belong to the astacin family. Subsequent cloning and sequencing of cDNA clones confirmed the identification of HMP1 as an astacin-like metalloproteinase. Immunocytochemical studies with antibodies generated against the purified enzyme and to a synthetic peptide indicated that HMP1 was localized to the ECM of tentacles. Functional studies were performed in which purified HMP1, anti-HMP1 IgG, or suspected substrates of HMP1 (e.g. growth factors such as TGF-beta 1) were introduced into the interepithelial compartment of hydra using a 'DMSO loading' procedure. These studies indicated that HMP1 has a functional role during a number of developmental processes such as head regeneration and cell differentiation/transdifferentiation of tentacle battery cells.

Amino Acid Sequence↗
PubMed1987

The mourning-liberation process in health and disease.

In this article I have presented my own research on the mourning-liberation process and related it to some of the ongoing work as well as past pioneering clinical studies of this adaptational process. Included in the references at the end of this paper is a listing of my published works on the mourning research, in chronologic order, for those who may wish to study aspects of what has been reported in greater detail.

Adaptation, Psychological↗
PubMed1986

Childhood sibling loss. A family tragedy.

The loss of a significant object, the loss of a home (security, personal possessions, familiar space that has emotional meaning), the dislocation from one's home or land as occurs in wars or disasters, gives rise to stress-strain responses that may have short-term or long-term effects, eg, post-traumatic stress disorder. The hidden or neglected victims of such occurrences frequently are children--be they siblings or direct descendants. In childhood sibling loss, the effects of the loss are mediated through different members of the family. The acute stressors can give rise to later adversity unless it is recognized that there is a social context in which life and death events occur. Recognizing these individual responses in the family can lead to interventions that may prevent later difficulty. Understanding the meaning of the events to the child, appreciating the fact that events are not just single occurrences, but interact with what existed before as well as with other concomitant events, helps in our therapeutic recommendations and interventions. Sibling loss, though initially related to the death of a sibling, can now be expanded to include the loss of a sibling through chronic illness (emotional, medical, surgical, long-term hospitalization), birth injuries, disabled children (accidents or illness with body changes), chronic illness with visible as well as non-visible changes that require special parental and nursing care, medication on an ongoing basis, and restrictions in diet and activities. The impacts of these losses without death can have devastating effects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1982

On ageing and psychopathology: discussion of Dr Norman A. Cohen's paper 'on loneliness and the ageing process'.

In an aetiological perspective one has to consider the following in working with the older adult: antecedent psychopathology, situational crises that strain the ego's ability to maintain equilibrium, organic illness which can increase reactive symptoms. Age in and of itself need not preclude psychoanalytic treatment. In my successful work with middle aged and older adults, I have found: the capacity for insight, for therapeutically induced transferences for dreams and the ability to relate these dreams; the capacity for self-observation; the mobilization of motivation to change and also of libidinal and constructive aggressive energies; the institution of a mourning-liberation process. In the treatment situation, the elderly easily distinguish between the facade of interest and genuine caring and involvement on the part of the therapist. Older patients wish to be useful, and to preserve their dignity. Unlike younger patients, they do not fear death. At times they may welcome it as a relief from pain and anguish. The goal of psychoanalytic treatment is to make more of people available to themselves for present and future creative and satisfying life experiences. This can occur in individuals who are middle aged, older aged, or in the younger group of analysands.

Adult↗