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Biomedical subjects

S Miller

Publications and source records attributed to S Miller.

At least 253 records · Page 14Linked to original sources
PubMed1995

[Sexual abuse in children: determination, identification and interventions].

Sexual and psychological abuse of children has drawn increasing attention from both the media and therapeutic institutions in recent years. This phenomenon has been amply determined to be widespread. 62% of children are victims of broadly defined psychological, physical and sexual abuse. Using stricter criteria, child abuse occurs in 6%. Most abusers are male relatives. The psychological model of the abuser cannot be determined, although risk factors in families in which abuse occurs can be identified. Children in distress due to sexual abuse do not usually report it, but the distress can be recognized because of hints and changes in the child's behavior. When children are identified as victims of sexual abuse, the welfare clerk or social worker should be informed immediately and the need for treatment determined. The purpose of this paper is to increase awareness of physicians, and particularly family physicians, of this phenomenon and of its frequency, as well as of the necessity for their interaction with treating factors.

Adolescent↗
PubMed1995

A simple genetic basis for a complex psychological trait in laboratory mice.

Psychological traits are commonly inferred from covariation in sets of behavioral measures that otherwise appear to have little in common. Emotionality in mice is such a trait, defined here by covariation in activity and defecation in a novel environment and emergence into the open arms of an elevated plus maze. Behavioral and quantitative trait analyses were conducted on four measures obtained from 879 mice from an F2 intercross. Three loci, on murine chromosomes 1, 12, and 15, were mapped that influence emotionality. This trait, inferred from studies of strain, sex, and individual differences in rodents, may be related to human susceptibility to anxiety or neuroticism.

Animals↗
PubMed1995

Roles of metabotropic glutamate receptors in brain plasticity and pathology.

In summary, the mGluRs are a large family of receptor subtypes with diverse properties in terms of transduction coupling, pharmacology, and anatomical distribution. Many divergent studies have demonstrated that activation of these receptors can result in either neuroprotection or neuropathology. We hypothesized that the mGluRs of astrocytes may have a role in determining the response following administration of mGluR agonists in vivo, and we have defined a suitable in vitro model for the study of these receptors. The experimental plasticity demonstrated in the astrocyte culture model may represent a more general principle that conditions in the microenvironment may differentially alter mGluR subtype expression as part of development, functional specialization, or pathology. This astrocyte model of receptor regulation provides a system suitable for studying the effects of specific growth factors, neurotrophins, cytokines, and other substances released by neurons and glia that may act in both autocrine and paracrine fashions. Alteration in the ratios of receptors by such variables could then modify future signaling properties and neuroglial interactions, a form of conditioning of the astrocytic response that would alter the physiological output following glutamate release. One measure of the value of this model will be its usefulness in stimulating the generation of hypotheses that can be tested in vivo. For example, the morphology of the astrocytes when cultured in the defined medium has similarities to the morphology of astrocytes undergoing reactive gliosis in pathological states. It is also interesting to note that treatments that have been reported to increase excitatory amino acid-stimulated PI hydrolysis in ex vivo brain slices (lesions, ischemia, and kindling) are accompanied by reactive gliosis. Those findings combined with the present in vitro results lead us to speculate that mGluR5 expression may also be altered in vivo during reactive gliosis. If so, it will be important to examine the functional consequences of such a change with regard to the astrocytic response to injury and maintaining the balance between excitatory transmission and excitotoxicity.

Animals↗
PubMed1995

Effects of individualized breast cancer risk counseling: a randomized trial.

BACKGROUND: Studies have shown that a majority of women with a family history of breast cancer have exaggerated perceptions of their own risk of this disease and experience excessive anxiety. In response to the need to communicate more accurate risk information to these women, specialized programs for breast cancer risk counseling have been initiated in medical centers across the United States. PURPOSE: Our purpose was 1) to evaluate the impact of a standardized protocol for individualized breast cancer risk counseling on comprehension of personal risk among first-degree relatives of index breast cancer patients and 2) to identify women most and least likely to benefit from such counseling. METHODS: This study is a prospective randomized trial comparing individualized breast cancer risk counseling to general health counseling (control). We studied 200 women aged 35 years and older who had a family history of breast cancer in a first-degree relative. Women with a personal history of cancer were excluded. Risk comprehension was assessed as the concordance between perceived "subjective" lifetime breast cancer risk and estimated "objective" lifetime risk. RESULTS: The results of logistic regression analysis showed that women who received risk counseling were significantly more likely to improve their risk comprehension, compared with women in the control condition (odds ratio [OR] = 3.5; 95% confidence interval [CI] = 1.3-9.5; P = .01). However, in both groups, about two thirds of women continued to overestimate their lifetime risks substantially following counseling. Examination of subjects by treatment interaction effects indicated that risk counseling did not produce improved comprehension among the large proportion of women who had high levels of anxious preoccupation with breast cancer at base line (P = .02). In addition, white women were less likely to benefit than African-American women (OR = 0.34; 95% CI = 0.11-0.99; P = .05). CONCLUSION: Efforts to counsel women about their breast cancer risks are not likely to be effective unless their breast cancer anxieties are also addressed. IMPLICATIONS: Attention to the psychological aspects of breast cancer risk will be critical in the development of risk-counseling programs that incorporate testing for the recently cloned breast cancer susceptibility gene, BRCA1 (and BRCA2 when that gene has also been cloned).

Adult↗
PubMed1995

Influence of electrical stimulation of the tibialis anterior muscle in paraplegic subjects. 2. Morphological and histochemical properties.

In adult paraplegic subjects one tibialis anterior muscle received daily electrical stimulation for 4 weeks at twice the motor threshold to determine changes of morphological and histochemical profiles (this paper) and of contractile properties (preceding paper). Bilateral biopsies, obtained 4 weeks before, and immediately after, electrical stimulation, were studied for fibre type proportions, fibre diameters, oxidative capacity, microvasculature and histopathology. Before stimulation the biopsies showed disuse with increased type 2 fibre proportions and decreased oxidative capacity (succinate dehydrogenase (SDH) activity). The effects of two stimulus patterns were compared. Following stimulation SDH activity increased significantly in all stimulated muscles. Inconsistent changes occurred in fibre type proportions, fibre diameters, capillary density and capillary/fibre ratios. Both stimulus patterns evoked similar results. In five/seven subjects subsarcolemmal vacuolation was observed. Electrical stimulation for 4 weeks at only twice motor threshold improves oxidative capacity, but different stimulus parameters are probably needed for significant fibre type conversion.

Adenosine Triphosphatases↗
PubMed1995

Influence of electrical stimulation of the tibialis anterior muscle in paraplegic subjects. 1. Contractile properties.

In adult paraplegic subjects one tibialis anterior muscle received daily electrical stimulation for 4 weeks at twice motor threshold to determine changes of its contractile properties (this paper) and its morphological and histochemical profiles (following paper). Force, speed of contraction and fatigue resistance were assessed by percutaneous electrical stimulation of the muscle with torque measured about the ankle. Comparative contractile tests were performed on 51 normal adult subjects and new parameters for force measurement proposed, particularly where maximum voluntary contraction cannot be obtained. In paraplegic subjects before stimulation the tibialis anterior muscle showed evidence of disuse with decreased force, faster contraction and relaxation, and reduced fatigue resistance. The effects of two stimulus patterns were compared: 10 Hz, and 10 Hz with 100 Hz bursts. After stimulation contraction was slower, fatigue resistance increased and there was a tendency for force to increase. No differences occurred using the different stimulus patterns. Four weeks later fatigue resistance was partially maintained, while speed of contraction reverted to pre-stimulus levels.

Adult↗
PubMed1995

The clinical nurse specialist: a way forward?

The words clinical nurse specialist have been part of the nursing vocabulary for some time, but are these nurses specialized practitioners like many of us, or is there a larger role for them to play? This paper is a piece of reflective writing and is intended to further the debate concerning clinical nurse specialists. The paper examines clinical nurse specialists from an intensive care unit perspective. It looks at the intensive care unit and the wealth of under-utilized experience these environments contain. The paper examines the existing and envisaged roles of clinical nurse specialists, their education and utilization, and also the difficulties that they are likely to face in their evolution, both from within the nursing profession and from outside it.

Burnout, Professional↗
PubMed1995

Fission fragment relative biological effectiveness for liver tumor induction.

The risk coefficients for liver tumors as derived from 60 beagles with body burdens of 249Cf or 252Cf were used to determine the relative biological effectiveness of fission fragments relative to alpha particles. For liver malignancies the relative biological effectiveness was calculated to be about 2 +/- 3. The estimate based on the combined benign and malignant liver tumors was about 7, with a proportionately larger standard deviation of about +/- 14. Although the confidence intervals were wide, it is possible that the relative biological effectiveness of fission fragments relative to alpha particles, using liver neoplasia as the endpoint, is greater than 1.0 as compared to a value only slightly above zero when bone cancer was the lesion of interest.

Alpha Particles↗
PubMed1995

Population diversity of B-locus alleles observed by high-resolution DNA typing.

HLA B-locus typing by group-specific PCR and hybridization with SSOP was performed in 81 10th IHWS B cell lines and 334 selected subjects of our local panel, from four ethnic groups. Most of the B-locus serological specificities were well defined. However, some antigens like B41, B58, B56, the splits of B14, and some subtypes of B5, were not accurately assigned by serology. In the panel studied, we found 17 hybridization patterns that corresponded to probable new alleles. New patterns occurred in the four ethnic groups examined. Multiple subtypes of B35, B5, B15, B41, B44, B57, B58, B70, B14, B40, B22 were found in subjects of the same ethnic group. In view of the poor serological definition of some alleles, and the occurrence of multiple subtypes in the same ethnic population, it appears that high resolution B-locus typing may be an important addition for detection of potentially relevant HLA incompatibilities in transplantation. It should also be valuable for population studies and for the investigation of HLA associations with diseases.

Amino Acid Sequence↗
PubMed1995

Viral tracer studies indicate contamination of marine waters by sewage disposal practices in key largo, Florida.

Domestic wastewater disposal practices in the Florida Keys are primarily limited to on-site disposal systems such as septic tanks, injection wells, and illegal cesspits. Poorly treated sewage is thus released into the highly porous subsurface Key Largo limestone matrix. To investigate the fate and transport of sewage in the subsurface environment and the potential for contamination of marine surface waters, we employed bacteriophages as tracers in a domestic septic system and a simulated injection well in Key Largo, Florida. Transport of bacteriophage (Phi)HSIC-1 from the septic tank to adjacent surface canal waters and outstanding marine waters occurred in as little as 11 and 23 h, respectively. Transport of the Salmonella phage PRD1 from the simulated injection well to a canal adjacent to the injection site occurred in 11.2 h. Estimated rates of migration of viral tracers ranged from 0.57 to 24.2 m/h, over 500-fold greater than flow rates measured previously by subsurface flow meters in similar environments. These results suggest that current on-site disposal practices can lead to contamination of the subsurface and surface marine waters in the Keys.

Journal Article↗
PubMed1995

Comparison of antimicrobial susceptibility methods for detection of penicillin-resistant Streptococcus pneumoniae.

We sought to determine if commercially available susceptibility tests were accurate in detecting penicillin resistance and relative resistance in Streptococcus pneumoniae. We compared the reference MIC method with oxacillin disk screening and three commercial tests, E-test (AB Biodisk), JustOne (Radiometer America), and MicroScan Pos MIC Panel Type 6 (Baxter Diagnostics), with 80 selected clinical isolates. Thirty-three additional isolates were tested by the reference method and the E-test to further validate the latter method. Oxacillin screening was effective in detecting all penicillin-resistant and relatively resistant strains of S. pneumoniae. The MicroScan method was not effective in detecting penicillin resistance or relative resistance. The JustOne system classified only 6 (35%) of 17 resistant strains correctly, with 11 resistant strains classified as relatively resistant. The E-test correctly classified 30 (83%) of 36 resistant isolates, with 6 resistant isolates interpreted as relatively resistant. For determining penicillin MICs for S. pneumoniae, the E-test was the most accurate of the commercial systems that we studied.

Humans↗
PubMed1995

Cross-protective immune responses induced in rhesus macaques by immunization with attenuated macrophage-tropic simian immunodeficiency virus.

The simian immunodeficiency virus (SIV) macaque model of AIDS has provided a valuable system with which to investigate vaccine approaches for protection against human immunodeficiency virus type 1 (HIV-1) infection. In particular, the ability of macaques persistently infected with attenuated infectious molecular clones of SIV to resist challenge with the pathogenic parental swarm has conclusively demonstrated that protective immunity can be achieved by immunization prior to exposure. The breadth of these protective responses and the immunological correlates of protection, however, have not been identified. In addition, vaccine studies have mainly employed lymphocyte-tropic strains of HIV-1 and SIV. Recent studies have implicated macrophage-tropic strains in the transmission of HIV-1 and have suggested that these virus strains should be examined in vaccine strategies. Macrophage-tropic viruses may confer additional advantages in the induction of protective immunity by replication in antigen-presenting cells. In this study, the immune response of rhesus macaques inoculated with an attenuated macrophage-tropic recombinant of SIVmac239 (SIV/17E-Cl) was evaluated with respect to protective immunity by heterologous challenge at various times after infection. Vigorous type-specific neutralizing-antibody responses restricted to SIV/17E-Cl were evident by 2 weeks postinfection. By 7 months, however, cross-reactive neutralizing antibodies emerged which neutralized not only SIV/17E-Cl but also the heterologous primary isolate SIV/DeltaB670. Challenge of SIV/17E-Cl-infected monkeys with SIV/DeltaB670 at various times postinfection demonstrated that protective responses were associated with the appearance of cross-reactive neutralizing antibodies. Furthermore, passive transfer of sera from SIV/17E-Cl-infected animals passively protected two of four naive recipients.

Animals↗