Colposcopy: who, when, where and by whom?
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Adult↗
Biomedical subjects
P Walker
Publications and source records attributed to P Walker.
Visual memory for pictorial stimuli in a serial choice reaction-time task.
Three experiments investigated the nature of the single-item visual recency effect in the serial choice reaction-time task (Rabbitt & Vyas, 1979; Walker & Marshall, 1982). The first experiment demonstrated that, like single letters varying in case, pictorial stimuli yield visual priming that is limited to consecutive stimuli and is unaffected by the presentation of an irrelevant stimulus in the response-stimulus interval. The second experiment confirmed that repeating a picture produces facilitation over and above repeating the object that it portrays. In addition, it was observed that name priming, but not visual or object priming, decreases with practice. This indicated that visual priming and object priming occur during identification. Finally, in Expt 3, an irrelevant picture was presented unpredictably in the response-stimulus interval. Previous results had suggested that this manipulation would provide evidence for distinct visual and object codes. Although the results were inconclusive, they do indicate that time intervals and presence of intervening information per se do not explain the loss of visual and object priming effects. It was suggested that the unpredictable irrelevant stimulus may have been disrupting a process whereby memory and perception interact directly at the level of a visual code.
Attention↗
Identification of estrogen-responsive DNA sequences by transient expression experiments in a human breast cancer cell line.
The expression of a hybrid gene formed by the promoter region of the Xenopus laevis vitellogenin gene B1 and the CAT coding region is regulated by estrogen when the gene is transfected into hormone-responsive MCF-7 cells. Furthermore, the 5' flanking region of the gene B1 alone can confer inducibility to heterologous promoters, although to a varying extent depending on the promoter used. Deletion mapping of he vitellogenin hormone-responsive sequences revealed that a 13 bp element 5'-AGTCACTGTGACC-3' at position -334 is essential for estrogen inducibility. We have shown previously that this 13 bp element is present upstream of several liver-specific estrogen-inducible genes.
Acetyltransferases↗
Life events stress and psychosocial factors in men with peptic ulcer disease. A multidimensional case-controlled study.
We carried out a case-controlled study of multiple psychological and social factors in 49 men with complicated or uncomplicated peptic ulcer disease. Thirty-two men with renal stones or gallstones and 20 healthy men served as controls. Ulcer patients and controls experienced a similar number of potentially stressful life events. However, ulcer patients perceived their events more negatively (p less than 0.05). Ulcer patients also had significantly more personality disturbances than controls, although no one type of "ulcer personality" was found consistently. Some ulcer patients tended to be hypochondriacal complainers, overly pessimistic, and excessively dependent. Other personality disturbances were also more common in ulcer patients (e.g., immaturity, impulsivity, and feelings of social isolation and alienation). Ulcer patients had significantly lower ego strength and they had fewer friends and relatives whom they felt they could call upon in times of crisis. Finally, ulcer patients exhibited significantly more emotional distress in the form of depression and anxiety. Hypochondriasis, a negative perception of their life events, dependency, and lowered ego strength were the four variables that best discriminated ulcer patients from controls. This controlled study demonstrates a strong association between life events stress, psychosocial factors, and peptic ulcer disease.
Adaptation, Psychological↗
Distribution of epidermal growth factor receptors in the rat ovary.
The distribution of epidermal growth factor (EGF) was studied in the ovary using light microscope radioautography which was performed at different time intervals (2-60 min) after intravenous (i.v.) injection of [125I]EGF into adult rat at random stages of the estrous cycle and also after topical localization of iodinated EGF on slide-mounted frozen ovarian sections. After i.v. injection of label, the labeling was mostly observed in the theca interna cells of secondary, preovulatory and atretic follicles and luteal cells of corpus luteum. Primordial and primary follicles did not show any significant labeling. The time-course study performed on luteal cells showed that, 2 min after injection, most silver grains were found at the periphery of the cells. At the 10 min time interval, silver grains were found both at the periphery and over the cytoplasm of these cells. The number of grains was very reduced over the cytoplasm at the 60 min time interval. In the in vitro study, a positive radioautographic reaction was seen in the same cellular elements as found in vivo, with the additional labeling of the granulosa cells of growing and preovulatory follicles. Control experiments indicated that the radioautographic labeling was due to specific interaction of [125I]EGF with its receptor. These results clearly indicate that EGF binding sites are present in luteal, thecal and granulosa cells, and provide support for the inhibitory and stimulatory actions of EGF on different parameters of ovarian cells.
Animals↗
The basis of Stroop interference involving the multimodal correlates of auditory pitch.
A pure auditory tone has a range of multimodal qualities that are determined by its pitch. A reaction-time task was used to demonstrate that subjects respond immediately and automatically to these qualities. Subjects were required to press one of two keys depending on which word, from a limited set, appeared on a microcomputer screen. The words were antonyms that represented multimodal stimulus qualities, and they were assigned to alternative responses so that the two words that shared the same response were correlated in the same way with pitch. As an incidental stimulus, either a 50 Hz tone or a 5500 Hz tone accompanied the presentation of each word. Subjects were found to respond more slowly when the multimodal qualities of the tone were incongruent with the qualities represented by the test word. When the stimulus-response mapping rules were changed, however, the Stroop effect did not occur; suggesting that a polarised semantic code of the incidental tone, that embraces its multimodal features, accesses the same semantic register as the equivalent code for the test word itself.
Auditory Perception↗
Thyroxine increases neonatal mouse submandibular gland mRNA-directed synthesis of epidermal growth factor.
Thyroid hormones are known to modulate the concentrations of epidermal growth factor (EGF) in the mouse submandibular gland (SMG); this action is presumably mediated by the nuclear triiodothyronine receptor. To test the hypothesis that thyroid hormones act to increase SMG EGF concentrations by increasing the number of poly(A)+ -specific mRNA, poly(A)+ RNA was isolated from SMGs of neonatal mice which had been treated daily from birth through to 21 days of age with thyroxine (T4,0.4 microgram/g body weight). Poly(A)+ RNA also was extracted from SMGs of intact 21-day-old mice which had received vehicle alone. No significant differences in total nucleic acid, total RNA, or poly(A)+ RNA yields were noted between the two groups of animals. The isolated poly(A)+ RNAs from T4-treated and control mice were translated in an in vitro wheat germ system. Although no significant differences in efficiency of [35S]cysteine incorporation into trichloracetic acid precipitable material were noted between the two poly(A)+ RNA preparations, a significantly greater proportion of radioactivity was immunoprecipitable by anti-EGF antiserum in the translation medium derived from T4-treated mice (17.2 +/- 0.9%, mean +/- SEM) than in that of control mice (7.3 +/- 0.5%, P less than 0.001). Polyacrylamide gel electrophoresis of the immunoprecipitates (IMMP) revealed the presence of three radioactive bands with apparent relative masses (MrS) of 12,000, 9000, and 6000. The latter species comigrated with purified EGF, [125I]EGF, and an IMMP of a SMG extract. The translation product IMMPs following polyacrylamide gel electrophoresis were iodinated and digested with alpha-chymotrypsin.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Distribution of epidermal growth factor binding sites in the adult rat liver.
The localization of epidermal growth factor (EGF) receptors was studied in the liver by use of light microscope autoradiography performed at different time intervals (2-60 min) after intravenous injection of 125I-EGF into adult rat. The results revealed a substantial binding of EGF to parenchymal cells of the liver. Control experiments indicated that the autoradiographic labeling was due to specific interaction of 125I-EGF with its receptor. A very steep portal-to-central lobular concentration gradient for 125I-EGF uptake was observed. The time course study performed on parenchymal cells of periportal regions of lobules showed that, at the 2-min time interval, most silver grains were found at the periphery of these cells and that the maximal values were reached 7 min after injection. After, the number of grains decreased progressively and their localization in the cytoplasm indicated the internalization of the ligand. The present results demonstrate that EGF injected into the general circulation preferentially binds to hepatocytes located in the periportal area and is rapidly internalized.
Animals↗
Thyroxine increases submandibular gland nerve growth factor and epidermal growth factor concentrations precociously in neonatal mice: evidence for thyroid hormone-mediated growth factor synthesis.
Thyroxine (T4) administration to adult female mice significantly increases submandibular gland (SMG) nerve growth factor (NGF) and epidermal growth factor (EGF) concentrations and does so in a time- and dose-dependent manner. Postnatal maturation of the SMG can be markedly accelerated by T4 treatment. We, therefore, performed a series of experiments to examine the effect of T4 on SMG NGF and EGF content and concentration as a function of postnatal age in neonatal mice. In experiment 1, male and female neonatal Swiss-Webster mice received daily subcutaneous injections of T4 (0.4 micrograms/g body weight) for 6, 13, or 20 days and were sacrificed 24 h after the last injection. Vehicle injected mice served as controls. SMG NGF and EGF content and concentration were measured by specific double antibody radioimmunoassay systems. Pools were made using either female or male SMGs. Since no significant differences were noted for NGF or EGF content using sex of the animal as the determining variable, the values were combined. At 7 days of age, mean SMG NGF and EGF content and concentration of control mice significantly exceeded those of T4-treated animals (p less than 0.05). At 14 days of age, mean SMG NGF and EGF content in T4-treated mice significantly exceeded those in control mice by 39- and 22-fold, respectively (p less than 0.001). At 21 days of age, these increases were 4100- and 2400-fold, respectively. In order to determine more precisely the time of onset of responsivity of the SMG to thyroid hormones, a second series of experiments was performed.(ABSTRACT TRUNCATED AT 250 WORDS)
Age Factors↗
Progressive polyradiculopathy in acquired immune deficiency syndrome.
We studied three patients with acquired immune deficiency syndrome (AIDS) and progressive polyradiculopathy. Postmortem examination of one patient disclosed extensive necrosis, inflammatory infiltrates, and focal vasculitis of spinal roots. Typical cytomegaloviral (CMV), intranuclear, and intracytoplasmic inclusions were noted within enlarged endoneurial and endothelial cells. Progressive polyradiculopathy is an unusual complication of AIDS; CMV may be the causative agent in certain cases.
Acquired Immunodeficiency Syndrome↗
Distribution of epidermal growth factor binding sites in the adult rat adrenal gland by light microscope autoradiography.
The distribution of epidermal growth factor (EGF) receptors was studied in the adrenal gland using light microscope autoradiography which was carried out 2 min after intravenous (iv) injection of [125I]EGF into adult rat. At the light microscope level, the labelling was found over the cells of the capsule and adrenal medullary chromaffin cells. No specific labelling of the steroid-secreting cells was observed. Control experiments indicated that the autoradiography reaction was due to specific interaction of [125I]EGF with its receptor. These results clearly indicate that EGF receptors are present in the majority of the adrenal medulla cells. They suggest that EGF may exert a physiological role in the regulation of rat adrenal medulla.
Adrenal Glands↗
Percutaneous transluminal coronary angioplasty--the Bristol experience of the first 32 cases, June 1984 to December 1985.
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Adult↗
Gastrointestinal autonomic nerve (GAN) tumor. Ultrastructural evidence for a newly recognized entity.
We describe three cases of spindle cell tumors arising in the gastrointestinal tract, each with ultrastructural features that recapitulate the ultrastructural morphology of the enteric autonomic nervous system. These features include the presence of small, dense core granules in the synthetic-secretory Golgi structures, sparsely distributed within the ample tumor-cell cytoplasm, near plasma-membrane surfaces and within axons. Tumor cells had elongated processes and axons contained small granular vesicles, clear vesicles, or large, dense vesicles. Specific features diagnostic for smooth-muscle cell, Schwann cell, or fibroblast cellular origin were absent.
Adolescent↗
Induction of a sustained fibrinolytic response by BRL 26921 in vitro.
The role of thrombus-binding in the fibrinolytic response to the acylated streptokinase.plasminogen activator complex, BRL 26921, has been examined using human plasma clots, radiolabelled with 125I-fibrin, in vitro. When clots were briefly exposed to BRL 26921, washed and returned to homologous plasma, lysis continued for up to 3 hours and attained approximately 25% of that lysis achieved by incubating with BRL 26921 for 5 hours. This continuing lysis was potentiated by return of exposed clots to alpha 2-antiplasmin-depleted plasma, or buffer and is attributed to an initial uptake of BRL 26921 rather than the binding of exogenous plasmin that was observed for streptokinase and high concentrations of urokinase. The sustained lysis is not explained by transfer of loosely-associated surface material or by dissociation of agent from the clot with reuptake from a dilute systemic pool. The response can be attributed, at least in part, to specific fibrin binding, mediated by kringles 1-4, for a low-molecular weight plasminogen (Val442) variant was less active.
Anistreplase↗
Population of triaxial rotor levels in 182Os.
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Journal Article↗
The effects of season of collection, feeding, maturation and gender on the potency of funnel-web spider (Atrax infensus) venom.
Assays of the venom of adult male and female as well as immature funnel-web spiders (Atrax infensus) were performed both at the end of the winter hibernation period and during the active summer months. For both sexes an increase in venom potency appeared to have occurred with the approach of summer, the venom of adult males then being clearly more potent than that of adult females. However, it was also found that, at least for adult females, forced abstinence from feeding was associated with an increase in venom potency, while feeding (at least on one insect species that A. infensus is known to accept as prey) seemed to lead to a lowered potency. From these observations it was concluded that the neurotoxin in the venom of female (and presumably also male) A. infensus spiders is probably synthesized in the venom glands rather than being extracted from the prey on which A. infensus normally feeds.
Animals↗
Human lymphocyte antigens: a mini review.
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Animals↗
Stroop interference based on the multimodal correlates of haptic size and auditory pitch.
In a preliminary experiment subjects were asked to explore three wooden knobs of different sizes and to rate each one on a series of 7-point scales. The results confirmed that an object may possess a number of multimodal qualities that are contingent on its haptic size. The pattern of intercorrelations between the qualities was consistent with the pattern that is observed when subjects respond to pure auditory tones varying in pitch. For example, small (high-pitched) sounds, like small objects, are judged to be sharp, thin, light, weak, fast, tense, and bright. The main experiments used a paradigm based on the Stroop interference effect. Subjects were required to press one of two keys as quickly as possible depending on which of four possible words appeared in the centre of the screen. A 50 Hz or a 5500 Hz tone accompanied each test word, and subjects responded on two keys that differed in size. Subjects were found to respond more slowly when either the pitch of the incidental sound or the size of the key on which they responded was incongruent with the multimodal features represented by the test word. The results confirm that people are automatically and immediately sensitive to the multimodal features of a stimulus when direct sensory evidence for the features is absent.
Form Perception↗