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Biomedical subjects

A Sheppard

Publications and source records attributed to A Sheppard.

At least 19 recordsLinked to original sources
PubMed1999

US Food and Drug Administration office of women's health: update.

The Food and Drug Administration's commitment to women's health issues began a new chapter with the establishment of the Office of Women's Health in 1994. This office has worked on the regulation of various products, on FDA policy relating to the inclusion of women of childbearing potential in early-phase drug trials, and on gender analysis of drugs. This commitment to women's health issues had its beginnings in the early 1980s. Actions taken by the agency since then include focusing on approving new drugs for diseases that specifically afflict women, taking steps to increase data on how drugs affect women, strengthening labeling information to give women a more accurate understanding of how certain drugs will affect them, and conducting public education campaigns. The Office of Women's Health will continue the agency's wide-ranging efforts from drug development and approval, to labeling, to policy formulation, to public education.

Female↗
PubMed1997

Parental separation: effects on children; implications for services.

It is commonly assumed that the children of separated or divorced parents are disadvantaged financially and in terms of social development. A small-scale study was designed involving 14 volunteer parents who were separated from their spouses/partners and their 28 children, ranging in age from 5 to 12 years. Structured interviews examined the families' attitudes and feelings about the separation, the mental health of the parents, the emotional and behavioural reactions of the children, and the families' use of services. The results suggested that over 60% of the girls showed internalizing, and over 60% of the boys displayed externalizing behavioural difficulties. About 40% of the children suffered psychosomatic disorders. Nearly 75% of the parents suffered depression before and after separation. Depression, itself, may act to exacerbate children's emotional and behavioural difficulties. Although all the parents had received medication for their depression, few of the children had received any help for their difficulties. The urgent need for services to help such children is discussed.

Child↗
PubMed1996

Evaluation of anti-viral filters.

The purification processes used to prepare medicines from human and animal cell lines provide one of the major opportunities for virus risk reduction. The purification process can be validated for its ability to remove a range of viruses and can be shown to provide a significant barrier to the transmission of viruses from cell substrates and raw materials to the patient. Ultrafiltration membranes which are manufactured with extremely tight control on pore size distribution can remove a broad spectrum of viruses with high efficiency. A scheme is described for the evaluation of anti-viral filters and the results from evaluation of two filters are presented. The experiments carried out with ultrafiltration membranes suggest that they can provide significant additional virus risk reduction factors for biopharmaceuticals.

Animals↗
PubMed1991

Proteolytic modification of neural cell adhesion molecule (NCAM) by the intracellular proteinase calpain.

The neural cell adhesion molecule, NCAM, is concentrated in synaptic regions and thus may contribute to the formation and maintenance of connections between brain cells. We present evidence that the cytoplasmic domain of NCAM can be experimentally modified by the intracellular calcium-dependent proteinase, calpain. This degradation could provide a mechanism for rapidly uncoupling and reorganizing synaptic contacts.

Animals↗
PubMed1991

Compartmentation and glycoprotein substrates of calpain in the developing rat brain.

An activated form of calpain I associates with telencephalic membranes in a developmentally regulated fashion during early postnatal ontogeny. During this period, the cytoskeletal component spectrin is available and appears to be differentially susceptible to calpain-mediated cleavage. Lectin blotting techniques demonstrated that the leupeptin-sensitive action of calpain is primarily directed toward large proteins which are glycoconjugate in nature; neuronal cell adhesion molecules are among the glycoproteins whose associations with the telencephalic membranes decrease due to calpain activity. These data suggest that cytoplasmic calpain is translocated to the membrane during early brain development in order to act on the cytoskeletal and adhesive structures responsible in part for neuronal shape and function.

Animals↗
PubMed1991

Fibronectin binding by brain synaptosomal membranes may not involve conventional integrins.

Synaptosomal plasma membranes (SPMs) from adult rat brain tested for fibronectin binding and antigenicity toward antibodies against integrin-type fibronectin receptors. Binding (1-10 pmol mg-1 protein) was considerably greater in SPMs than in homogenates for hippocampus and neocortex but not for brain stem. The tetrapeptide L-arginyl-glycyl-L-aspartyl-L-serine blocked up to 90% of the binding indicating that integrin-type receptors are present. Antibodies against two sub-classes of integrins detected high Mr integrin subunits in homogenates but not in SPMs. However, antibodies against hamster ovarian fibronectin receptor reacted intensely with polypeptides of 55,000 and 40,000 Mr that were concentrated 20 to 40-fold in SPMs compared to homogenates. These peptides may constitute a new class of matrix receptor involved in synaptic adhesion.

Animals↗
PubMed1991

Antibodies to the alpha v beta 3 integrin label a protein concentrated in brain synaptosomal membranes.

Immunochemical methods were used to test whether vitronectin receptors exist in synaptosomal membranes (SPMs) and hence are positioned to play a role in synaptic adhesion. Antibodies against the alpha v beta 3 integrin detected proteins in brain homogenates that correspond to conventional integrin subunits. Conversely, these antigens were not found in SPMs prepared from the same brain tissue. The antibodies did, however, express strong immunoreactivity towards a 27 kDa polypeptide that was greatly concentrated in SPMs from major brain regions and that was not found in tissues other than brain. This is an example of an integrin epitope contained in a synaptic polypeptide that is too small to be a conventional matrix receptor, thus, suggesting the possibility that synaptic adhesion involves unusual proteins.

Amino Acid Sequence↗
PubMed1990

Comparison of different medium bases for the semiquantitative isolation of anaerobes from vaginal secretions.

Two studies were performed to determine the best medium for the isolation of anaerobes from vaginal secretions. In the first, three different medium bases (brucella, Centers for Disease Control [CDC], and Schaedler) were compared semiquantitatively for ability to support the growth of gram-negative anaerobes from vaginal fluid. Media were supplemented with laked sheep blood, kanamycin, and vancomycin. The brucella base agar formulation supported the growth of anaerobic gram-negative bacilli better than either the CDC or Schaedler base agar formulation. In a second study, nonselective brucella and CDC base sheep blood agar were compared for ability to support the growth of anaerobic gram-positive cocci. Anaerobic gram-positive cocci grew in higher concentrations on CDC base agar than on brucella base agar. On the basis of these observations, we recommend that a CDC base sheep blood agar be used for the nonselective plate and a brucella base plate supplemented with laked sheep blood, kanamycin, and vancomycin be used for isolation of gram-negative bacilli in studies of the anaerobic flora of the female genital tract.

Bacteria, Anaerobic↗
PubMed1987

Use of the fluorescent dye, fast blue, to label sympathetic postganglionic neurones supplying mesenteric arteries and enteric neurones of the rat.

Neuronal pathways in the peripheral nervous system have been traced using the fluorescent dye, Fast blue. Following implantation of a gelatin pellet containing the dye, or direct injection of the dye into the mesentery beside an artery, Fast blue is taken up by both nerve terminals and axons of passage, retrogradely transported by large numbers of sympathetic neurones and retained within the neurones for long periods of time without diffusion. Neurones projecting to both blood vessels of the mesentery and submucosa and to enteric ganglia of the segment supplied by the artery were found labelled in prevertebral and paravertebral ganglia as well as in ganglia lying along the major splanchnic nerves. Attempts to separate the vascular component from those neurones innervating enteric ganglia suggest that the latter are located in the prevertebral, coeliac and superior mesenteric ganglia and to a lesser extent in the splanchnic ganglia, while the vasomotor neurones are located in prevertebral, paravertebral and splanchnic ganglia.

Adrenergic Fibers↗
PubMed1985

A study of the substance P innervation of the intermediate zone of the thoracolumbar spinal cord.

Immunocytochemical procedures have been used to examine the distributions of substance P (SP)-positive fibres within the intermediate zone of the thoracolumbar spinal cords of rabbits, cats, and monkeys. In all three species SP fibres were concentrated in areas known to contain sympathetic preganglionic neurones. These included the intermediolateral nucleus and the funiculus just lateral to it, the medial gray matter in the area of the nucleus intercalatus, and the paracentral region. The density of the SP innervation varied in a characteristic way both between these subpopulations of sympathetic neurones and in its overall input to different segmental levels. Generally the greatest accumulations of SP fibres were found in the T3-T5 and L2-L4 regions and these were concentrated in the intermediolateral nucleus (ILN). The highest densities of SP fibres in the lateral funiculus were in the upper thoracic and upper lumbar segments whereas SP fibres forming transverse bands, possibly in association with neurones in the nucleus intercalatus, were most prominent in T5-T8. Substance P fibres adjacent to the midline were more or less equally dense throughout the segments examined. Substance P-positive cell bodies situated immediately lateral to the central canal were present at a density of 200-300 per segment throughout the cat thoracolumbar cord. These neurones may be the cells of origin of at least some of the SP fibres in the intermediate zone. The close association of sympathetic preganglionic neurones with SP fibres, many of which are thought to be derived from cells in the medulla, suggests a role for SP-containing fibres in the modulation of sympathetic activity. The variation in input to different segments and classes of sympathetic neurones further suggests a specificity which may be related to the different functions of the neurones innervated.

Animals↗
PubMed1982

Localization in transcortical sensory aphasia.

Transcortical sensory aphasia is a syndrome characterized by poor comprehension but excellent repetition. The lesions shown on computed tomography and isotope scans of 15 patients who satisfied the objective criteria based on test scores were studied. The overlap technique showed a unique posterior parieto-occipital location of lesions. The lesions seem to separate into two groups: one is more medial, inferior, and posterior and is clearly in the posterior cerebral artery territory, and the other is relatively more lateral, superior, and anterior and seems to be in a watershed area between middle cerebral and posterior cerebral arteries. The lesion sizes correlated with severity. Frequent recovery and good prognosis are associated with this entity. Association with transient visual agnosia and hemianopsia confirmed the anatomical correlation.

Aged↗
PubMed1981

The epidemiology of aphasic and cognitive impairment in stroke: age, sex, aphasia type and laterality differences.

Sex differences and age distribution are examined in various types of aphasia and in right hemisphere-damaged patients due to acute infarct. The language and performance deficits were measured by a standardized test allowing us to group patients meaningfully. The higher male to female ratio of aphasia is shown to relate to a similar sex distribution in infarcts rather than to sex differences in cerebral organization. Broca's aphasics were somewhat younger than the other groups and the slight difference may be related to pathophysiological factors favouring embolic strokes in the anterior territory of the middle cerebral artery. Sex and aphasia types were not significantly different in various age groups except about 50 years of age where the female aphasics reversed the ratio.

Adolescent↗
PubMed1981

Response to cartoons and attitudes toward aging.

Although it has commonly been asserted that cartoon images of aging convey deep psychological significance, the relationship between attitudes and cartoon appreciation has received little systematic attention. The present study examined the relationship between responses to cartoons and attitudes toward aging among college students. Subjects rated the funniness of 60 cartoons and completed the Attitudes Toward Aging Inventory, Tuckman-Lorge, and Semantic Differential. Factor analysis revealed four categories of cartoons on aging: Disparagement, Ineffectuality, Obsolescence, and Isolation. No significant relationships were found between attitudes and humor appreciation, although age and education were inversely related to several cartoon themes.

Adult↗