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Biomedical subjects

C Murphy

Publications and source records attributed to C Murphy.

At least 37 records · Page 2Linked to original sources
PubMed1991

Sensory and semantic factors in recognition memory for odors and graphic stimuli: elderly versus young persons.

In four experiments, young (18-26 years, M = 21) and elderly (over 65 years, M = 72) people were compared for recognition memory of (a) graphic stimuli (faces of presidents and vice presidents, engineering symbols, and free forms) and (b) everyday odors. On graphic stimuli, the elderly consistently matched the young, but on odors the performance of the elderly was worse. Their poorer olfactory performance was observed after only 26 s, but became truly marked after 1 hr or more. Somewhere between 1 hr and 2 weeks, their odor performance fell to chance, but their graphic performance remained well above chance. Although the young did forget both graphic and odor materials progressively, their performance always stayed above chance over a 6-month period. Experiments 1 and 2 revealed that the elderly are less sensitive to odors than the young (with thresholds about 10-fold higher), which may explain, in part, their poorer olfactory memory performance. Knowledge that the subjects brought to the tasks by way of familiarity with and ability to name odors and faces played a positive role in recognition memory. Because of this positive role, together with the negative role played by verbal distraction, we conclude that odor recognition memory depends, perhaps heavily, on semantic processing. Impaired semantic processing may result even when odors are simply rendered desaturated, or pastel because of the weakening of olfactory sensitivity with aging.

Adolescent↗
PubMed1990

A monoclonal antibody that recognizes a phosphorylated epitope stains lampbrush chromosome loops and small granules in the amphibian germinal vesicle.

An mAb library was produced against proteins from the germinal vesicle (GV) of the frog Xenopus laevis; mAb 104 was selected from this library on the basis of its immunofluorescent staining of lampbrush chromosome loops. Chromosomes from several species of frogs and salamanders stained equally well. The antibody also stained the surface of numerous small granules in the GV nucleoplasm. The interior of the same granules was stained by antibodies against small nuclear ribonucleoproteins (snRNPs). mAb 104 also stained somatic nuclei from many vertebrate and invertebrate species, usually in a finely punctate pattern similar to that described for anti-snRNP and other antinuclear antibodies. The staining of somatic nuclei was much stronger during the mitotic stages than during interphase. Immunoblot analysis showed that mAb 104 recognizes a phosphorylated epitope.

Animals↗
PubMed1990

Epinephrine effects on major cell types of the aqueous outflow pathway: in vitro studies/clinical implications.

We have investigated the possibility that direct cellular effects may mediate the action of EPI to lower the IOP. To do this, cultured HTM and SCE cells were grown as monolayers over a millipore-filter support structure. The monolayers were exposed to various adrenergic agonists and antagonists while flow of the perfusate (DME + 5% FBS) was measured using a specially-designed computer-linked apparatus. Exposure of the cells to 10(-5) M EPI for around 2 hours led to a rapid twofold increase in HC which gradually declines over the next 12 hours. Continuous exposure of either cell type (ie, HTM or SCE cells) to EPI or ISO resulted in a four- to eightfold increase with a maximal effect measured around 10 hours and a half maximal effect at 2.5 hours. Administration of c-AMP alone gave similar responses. In agreement with clinical studies, timolol blocks EPI's effect completely while betaxolol acted as a partial antagonist. These findings suggest that the cellular changes and the increase in HC are mediated by a beta-2 receptor. There are many similarities between the responses observed using our in vitro system and the IOP-lowering response observed in vivo after the topical application of EPI (eg, concentration, time course, duration, and magnitude). The clinical implications of these preliminary results are discussed and it is proposed that the described in vitro system may be useful to select new adrenergic drugs for glaucoma therapy.

Adrenergic beta-Agonists↗
PubMed1989

Uterine receptivity in women receiving steroid replacement therapy for premature ovarian failure: ultrastructural and endocrinological parameters.

Endometrial biopsies and plasma oestradiol (E2) and progesterone (P4) levels in 23 patients were evaluated during 26 replacement therapy cycles for premature ovarian failure. Plasma E2 and P4 levels showed wide patient to patient variability, despite each patient being given the same hormone replacement therapy. Biopsies were studied by conventional histological dating and scanning electron microscopy (SEM). Eight morphological features of the surface epithelium that have previously been linked to uterine receptivity for implantation were identified and quantified. No correlation was found between endometrial surface morphology by SEM and circulating E2 and P4 levels. The results of this study do not support the hypothesis that there is an obligatory link between any of the eight morphological features measured in this study and uterine receptivity for implantation. To date, three ongoing pregnancies have been achieved following 18 embryo transfers to a total of 10 of the women in the study group.

Adult↗
PubMed1989

Quality-specific effects of aging on the human taste system.

Elderly persons are known to have elevated taste thresholds, with those for bitter more affected by age, for example, than those for sweet. Do analogous quality-specific effects occur at suprathreshold levels? Young (mean age = 20.3 years, SD = 2.99) and elderly (mean age = 72.5 years, SD = 4.58) subjects made magnitude estimates of sweetness, bitterness, sourness, and saltiness for the unmixed components sucrose, caffeine, citric acid, and NaCl at three concentration levels for each. They also made magnitude estimates of the separate taste qualities in two-component mixtures of sucrose with each of the other three qualities, at various levels of the two components in each mixture. Magnitude estimates of taste intensity were interweaved with magnitude estimates of the heaviness of six weights, which subjects were to judge on the same subjective intensity scale: This is the calibration feature of the method of magnitude matching, and permits the comparison of elderly and young subjects on the absolute intensity of tastes. When unmixed components were judged, elderly subjects found the characteristic tastes of caffeine and citric acid less intense than, but those of sucrose and NaCl as intense as, younger subjects did. In judging mixtures, the elderly found bitterness, but not the other three qualities, less intense than did the young subjects.

Adult↗
PubMed1989

Aging is associated with increased Weber ratios for caffeine, but not for sucrose.

To investigate whether age-associated changes in the human taste system are quality-specific, we compared young and elderly subjects' suprathreshold discrimination abilities for caffeine and sucrose. The method of constant stimuli was used to obtain just noticeable differences and Weber ratios. The elderly generated larger Weber ratios than did the young for both the medium and high concentrations of caffeine, but not for the low concentration. For example, a 74% increase in .005 M caffeine was required to obtain a perceptible difference for the elderly, whereas a 34% increase produced a perceptible difference for the young. The Weber ratios for sucrose did not differ for the two age groups. The results of this study indicate that age-associated changes in the taste system are quality-specific.

Adolescent↗
PubMed1989

Nail changes associated with scleroderma: a case report.

A case report and literature review on the association of nail changes and scleroderma was presented. The exact etiology of these nail changes seen in scleroderma and of the disease entity itself, has not yet been determined. The current treatment regimen, which is at best supportive, was discussed. Proper treatment of the nail changes depends on a good understanding of what to expect as the disease or condition progresses to its later stages. The extent and severity of the onychodystrophy can be correlated with the duration of the disease. Nonetheless, there are still questions that remain to be answered regarding the nail changes associated with scleroderma. For example, are these nail changes the result of Raynaud's phenomenon and its associated arterial insufficiency, or are they a normal sequelae of the integumentary degeneration so characteristic of scleroderma? Whatever the answer may be, it should be recognized that these changes are a source of clinical concern. Practitioners should take note of this clinical entity and record their findings so that these perplexing questions, as well as many others, may be discussed in the future.

Adult↗
PubMed1988

Doppler ultrasound signal analysis based on the TMS320 signal processor.

Doppler ultrasound is an established method for the study of haemodynamics. Considerable improvement in accuracy and resolution can be achieved by utilizing advanced data processing techniques. Such a system has been developed and used to assess the cardiac component of the Baroreceptor Reflex in adults and to examine cerebral blood flow in neonates.

Blood Flow Velocity↗
PubMed1988

Current developments in non-invasive measurement of arterial blood pressure.

Two new types of non-invasive method for measuring arterial blood pressure recently developed by us are reviewed. Both of the methods are based on the characteristics of the pressure-volume relationship in the artery. One is the volume-oscillometric method; and the other is the volume-compensation method, based on the vascular unloading principle. Both methods employ photoelectric plethysmography for detection of arterial volume changes in the biological segment. The volume-oscillometric method can measure systolic and mean arterial pressure, and is applicable to long-term ambulatory monitoring. The volume-compensation method allows the beat-by-beat measurement of systolic and diastolic pressure and the recording of the pressure waveform continuously and non-invasively. This paper discusses the measurement principle and evaluates the accuracy of each method as compared with direct measurements. Preliminary descriptions of newly designed instruments based on these two methods, and a few examples of the indirect pressure recordings, are also described. The results obtained show that the non-invasive methods for measuring arterial pressure presented here appear promising for use not only in physiological studies, but also in clinical practice and research laboratories.

Animals↗
PubMed1988

Endometriosis and the gut.

Six patients with endometriosis involving the intestine are described and illustrate the variety of symptoms which may occur in this condition, many of which are frequently associated with the more common gastrointestinal illnesses. A correct preoperative diagnosis based on history, clinical examination, radiology, and endoscopy may be difficult to make, and when first discovered at laparotomy endometriosis can easily be mistaken for other inflammatory, or neoplastic processes. A histological diagnosis should always be made before definitive treatment.

Adult↗