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Biomedical subjects

D Henderson

Publications and source records attributed to D Henderson.

337 records · Page 19Linked to original sources
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All my buddies was male: relationship issues of women with addictions.

There is a common perception that women who abuse drugs and alcohol do not like women. How does this attitude relate to women's abuse of drugs, and what difference might it make to the nursing care of addicted women. The importance of relationships to self and others has been emphasized in nursing theories, recent theories of women's psychologic development, and the social models used to explain substance abuse. This article examines what is known about the interpersonal relationships of women with addictions, including those with men and with other women, and explores how those relationships are associated with women's substance abuse behaviors. A brief explanation of current theories of women's psychologic development is followed by a review of the literature regarding the relationships of women with addiction problems, highlighting their attitudes toward themselves as women and the importance of the adult mother-daughter relationship. Implications for the treatment of addicted women by nurses are discussed.

Adult↗
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Remote masking in normal-hearing and noise-exposed chinchillas.

Remote masking (RM), the phenomenon whereby an intense high-frequency masking noise elevates thresholds for low-frequency signals, has been shown to be sensitive to various types of hearing loss in humans. We performed two experiments to evaluate the chinchilla as a model of RM and to examine changes in RM associated with temporary threshold shifts (TTSs) induced by low-frequency noise exposure. Thresholds for 0.5-, 1- and 2-kHz tones were measured in quiet, then in the presence of a narrow-band (300-Hz-wide) masking noise centered at 3 kHz. In Experiment I, effective masking was measured as a function of masker level, from 48 to 98 dB sound pressure level (SPL; referenced to 20 microPa), to determine threshold and rate of growth of RM in the chinchilla. In Experiment II, RM was measured before, during and after exposure to a low-frequency noise known to produce TTSs in chinchillas (i.e., a 0.5-kHz octave band noise at 90 dB SPL for 6 h/day for 10 days). The results show that normal-hearing chinchillas have the same pattern of RM as humans, and that a noise exposure that produces TTSs also produces rapid and significant changes in RM.

Animals↗
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Effects of combinations of sodium salicylate and noise on the auditory threshold.

Thirty-nine monaural chinchillas were used to study the interaction between sodium salicylate and various TTS-producing noise paradigms. Five animals were included in each of the following three groups: 1) sodium salicylate (400 mg/kg) plus 2-4 kHz, 95 dB SPL noise band for one hour; 2) sodium salicylate (400 mg/kg) plus 4 kHz CF octave band noise at 80 dB SPL for 96 hours; and 3) sodium salicylate (400 mg/kg) plus 50 impulses having 50 musec A-duration and 158 dB peak SPL, presented at one per minute. The remaining 24 animals served as various controls in groups exposed to sodium salicylate or the noise paradigm alone. Thresholds were estimated before, during, and after exposure using the AER technique and cochleagrams were mapped for each cochlea 30 days after exposure. When sodium salicylate was combined with the various noise conditions, the maximum TTS values obtained from the combination studies were comparable to those obtained from the single agent producing the greatest TTS at a particular frequency. No consistent alteration in either magnitude or time course of posttreatment threshold shift was found following the combination treatments as compared to the individual agents alone. Hazard to the auditory system resulting from a combination of sodium salicylate and noise was concluded to be no greater than the hazard presented by either agent alone. This result is also substantiated in the histological results.

Animals↗
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The consistent occurrence of a striated organelle (Friedmann body) in the inner hair cells of the normal chinchilla.

Striated organelles have consistently been observed in electron micrographs of serial sections from the inner hair cells of normal chinchilla cochleas. The striated organelle is located in the infracuticular plate region. It lines the cuticular plate, and the direction, pattern and periodicity of the striations vary along its length. The striated organelle is seen in close association with the cell membrane, smooth endoplasmic reticulum, microtubules and mitochondria. The striated organelle may play an active role in inner hair cell function, and its proliferation under pathological conditions, as observed by others, may be accompanied by alterations in sensitivity of the inner hair cell to stimuli.

Animals↗
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Correlation of audiometric data with changes in cochlear hair cell stereocilia resulting from impulse noise trauma.

In a previous experiment, after chinchillas had been exposed to impulse noise trauma, plastic-embedded surface preparations of the organ of Corti were examined with the light microscope. A consistent relationship between cochlear hair cell loss and hearing loss was not found (Hamernik et al., 1980). In the present study, four cochleas from that experiment were sectioned and examined with the transmission electron microscope to determine if their were consistent patterns of damage to the sensory cells at the ultrastructural level that would more closely correlate with the audiometric data. Alterations of the outer hair cell stereocilia were found when threshold was elevated 15 to 30 dB. The membranes of the stereocilia appeared loose and wrinkled and the stereocilia were no longer erect. In some cases, predominantly in the first row of outer hair cells, stereocilia were missing and in other cases, stereocilia were fused. Within these giant stereocilia, the rootlets of the individual stereocilia had disintegrated. Other alterations in sensory cell ultrastructure, though present, had no consistent pattern and could not be related to changes in hearing thresholds. Only the changes in the outer hair cell stereocilia appeared to correlate with hearing loss and the degree of damage was reflected in the amount of threshold elevation.

Animals↗
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Threshold-duration function of the acoustic reflex in man.

The threshold-duration function of the acoustic reflex was investigated in 5 male and 5 female adult, normal-hearing humans and in 3 adult male subjects with hearing loss of cochlear etiology. Reflex threshold was obtained at stimulus durations of 10, 20, 50, 100, 200, and 500 msec and at frequencies of 500, 1 000, 2 000, 3 000, and 4 000 Hz. Three commercially available acoustic bridges were employed, the Madsen ZO-70 and Grason-Stadler 1720 electroacoustic bridges, and the Grason-Stadler-Zwislocki model 3 mechanical-acoustic bridge. A probe-tone frequency of 220 Hz was used in all measures. The reflex threshold-duration function for normal-hearing subjects was found to encompass a much greater range of intensity than the psychophysically assessed auditory threshold temporal integration function. A sex difference was found which may be explained by subclinical noise-induced cochlear pathology in the male subjects with subsequent truncation of the reflex threshold-duration function. The function was also found to be truncated in the 3 subjects with hearing loss diagnosed to be of cochlear etiology. The implications of these findings for control of stimulus duration in clinical reflex measurement was discussed.

Acoustic Stimulation↗
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Intersecting race and gender in feminist theories of women's psychological development.

Although self-in-relation theory is the predominant feminist position on women's psychological development in the nursing literature, other voices and views, particularly from feminists of color, have challenged the thinking about the psychology of women. This article explores the intersectionality of race and gender in feminist theories of women's psychological development and mental health. It begins with a brief review of psychoanalytic feminism, focusing primarily on the work of Chodorow and what is labeled "self-in-relation" theory as it has been applied in (primarily mental health) nursing. This is followed by a discussion of the perspectives of several feminists of color concerning women's psychological development, perspectives that both challenge and concur with the views of psychoanalytic feminists. The final section presents the implications of these various feminist perspectives (and their challenges to each other) for feminist work in mental health nursing.

Female↗
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Atamestane, a new aromatase inhibitor for the management of benign prostatic hyperplasia.

Atamestane is a new, competitive, and irreversible inhibitor of estrogen biosynthesis. Its pharmacologic action has been evaluated in mice, rats, rabbits, dogs, monkeys, and humans. In rats, atamestane leads to a decrease of pregnant mare serum gonadotropin-stimulated ovarian estrogen production, and inhibits androstenedione-induced estrogenic effects such as uterine growth and abortion. In all species tested, atamestane lacks other intrinsic hormonal or antihormonal activities, and shows no inhibition of other cytochrome P450-dependent enzymes of adrenal steroidogenesis. However, it inhibits estrogen-related negative feedback. The extent and consequences of the induced counterregulation of the pituitary-hypothalamic axis show major sex- and species-specific differences. Atamestane is highly effective in inhibiting estrogen-induced hyperplastic changes in the fibromuscular stroma of the prostate in androstenedione-treated dogs and monkeys. In male volunteers and patients with benign prostatic hyperplasia (BPH), atamestane induces an expected reduction of serum (and BPH tissue) estrogen concentrations without significant changes in androgen levels. In conclusion, all available results indicate that atamestane is a selective (no inhibition of adrenal function), pure (no endocrine side effects), and highly effective steroidal aromatase inhibitor, with an excellent safety profile. Based on the discussion of its clinical potential, atamestane seems to be a promising compound for the management of BPH.

Androstenedione↗
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Biologic bases of noise-induced hearing loss.

The effects of noise are pervasive, and pathology can be found in the neural, sensory, supporting, and vascular cells of the cochlea after certain noise exposures. Several issues need to be addressed. First, what is the source of the wide range of susceptibility seen in people and animals that have similar noise histories but markedly different response to noise? Does this suggest a genetic factor in susceptibility to NIHL? Second, given the complexity of the biologic changes following noise exposures, it is difficult to predict the underlying pathology from standard audiologic tests. However, it would be desirable to distinguish sensory and neural and strial pathology because it is likely that the success of any aural rehabilitation will depend on knowledge of the type of pathology. This chapter focuses on a number of the traditional issues surrounding NIHL. However, one of the most exciting recent findings that undoubtedly will affect people with NIHL is that it is possible for sensory cells to regenerate. Research into the fundamental biochemical processes responsible for inducing regeneration is being pursued at a number of laboratories. The hope is to be able to repopulate the mammalian sensory epithelium with viable sensory cells.

Animals↗
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Pentavalent 99mTc DMSA: uptake into a variety of human rhabdomyosarcoma xenografts.

BACKGROUND: Rhabdomyosarcoma is a common soft tissue sarcoma of childhood. While Ga is currently the most accurate modality for imaging residual or recurrent tumour its dosimetry is unfavourable. Pentavalent 99mTc DMSA [99mTc (V) DMSA] has been shown to accumulate in this tumour in a limited number of clinical cases. METHODS: Biodistribution of 99mTc (V) DMSA was determined in non-tumour bearing BALB-C mice. Operative specimens from four clinically 67Ga avid tumours were xenografted into nude mice and allowed to reach a significant size. Biodistribution studies were performed after the injection of 99mTc (V) DMSA in all animals and 125I HSA and 67Ga in a limited number of animals. RESULTS: None of the tumours investigated demonstrated significant 99mTc (V) DMSA accumulation. Biodistribution was identical in tumour and non-tumour bearing animals. CONCLUSIONS: Rhabdomyo-sarcoma xenografts do not demonstrate significant uptake of 99mTc (V) DMSA.

Albumins↗