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Biomedical subjects

C S Miller

Publications and source records attributed to C S Miller.

At least 37 records · Page 2Linked to original sources
PubMed1999

Prevalence of infective endocarditis in patients with systemic lupus erythematosus.

BACKGROUND: Compared with the general population, patients with systemic lupus erythematosus, or SLE, have an increased prevalence of functionally impaired cardiac valves due to the presence of Libman-Sacks lesions. These lesions may place patients with SLE at risk of developing infective endocarditis, or IE. METHODS: The authors performed a retrospective chart review to determine the association between SLE with valvulopathy and IE. They reviewed the records of 361 patients from two health care facilities who had the diagnostic code of SLE. RESULTS: Of the 275 records that met the 1982 revised American Rheumatism Association criteria for SLE, 51 (18.5 percent) were for patients who had a clinically detectable heart murmur that resulted in echocardiography being performed. Nine (3.3 percent) of the 275 patients had a clinically significant valvular abnormality, three (1.1 percent) had a potentially significant valvular abnormality, and one (0.4 percent) had a history of IE that was diagnosed two years before her diagnosis of SLE was made. CONCLUSIONS: The findings suggest that 18.5 percent of this cohort of patients with SLE had a clinically detectable heart murmur that would require further investigation to determine its significance. Furthermore, between 3.3 and 4.4 percent of the study population had cardiac valve abnormalities that potentially required antibiotic prophylaxis before certain dental procedures. However, the authors identified no cases that demonstrated an association between IE and diagnosed SLE. CLINICAL IMPLICATIONS: Dentists should query their patients with SLE about their cardiac status and consult with the patient's physician if the cardiac status is unknown. Patients with confirmed valvular abnormalities should receive antibiotic prophylaxis for designated bacteremia-producing dental procedures.

Adolescent↗
PubMed1999

Establishment of a quiescent herpes simplex virus type 1 infection in neurally-differentiated PC12 cells.

Rat pheochromocytoma (PC12) cells differentiated with nerve growth factor (Nd-PC12) were used to investigate the establishment of a non-productive herpes simplex virus type 1 (HSV-1) infection that is reversible. The results of this work are as follows: (i) Nd-PC12 cultures could be maintained as long term (>7 weeks) non-dividing cultures only when plated on collagen-coated dishes in the absence of serum; (ii) Infection of Nd-PC12 with HSV-1 strains KOS and 17 in the transient presence of acycloguanosine (ACV) resulted in all cultures free of detectable levels of infectious virus at the time of ACV removal and ACV was not needed to maintain the non-productive quiescent state in the subsequent 8 weeks; (iii) These persistently infected and quiescent (QIF)-PC12 cultures demonstrated both spontaneous and forskolin-inducible virus production, at low (5%) and high frequencies (92-100%), respectively during the first 2 weeks post-ACV withdrawal. (iv) In contrast to other in vitro models, HSV-1 failed to reactivate following removal of nerve growth factor. (v) A high percentage of QIF-PC12 cultures (50-100%) produced virus in response to forskolin treatment as long as 7 weeks post-ACV withdrawal. (vi) Expression of HSV-1 productive genes (i.e. alpha0, alpha4, alpha27, UL30 and UL18) dropped precipitously in the presence of ACV and remained undetectable or continued to decline following its removal, whereas the levels of LAT and the host gene G3PDH remained relatively constant throughout the 31 day study period as measured by RT-PCR. These results indicate that QIF-PC12 cells offer a novel, neuronal cell culture system that may enhance our ability to study HSV-1 reactivation from a cryptic, latent-like, non-productive state in the absence of replication inhibitors.

Acyclovir↗
PubMed1999

Heat stress activates production of herpes simplex virus type 1 from quiescently infected neurally differentiated PC12 cells.

We have previously described a novel in vitro model of a non-productive herpes simplex virus type 1 (HSV-1) infection in neurally differentiated (Nd)-PC12 cells that allows for inducible virus replication upon forskolin treatment. In this study, we further characterized the quiescent state of infection and examined the ability of heat stress (HS) to induce virus from this non-productive state. These studies demonstrated that (i) the quiescent state is characterized by the absence of cell-associated virus, capsids, and viral antigens; (ii) HS (43 degrees C, 3 h) efficiently activated virus from quiescently infected Nd-PC12 (QIF-PC12) cells; (iii) the rate of virus production was significantly greater following HS than forskolin treatment, and the rates of both were dependent on MOI; (iv) forskolin and HS appeared to affect pathways of viral activation from a quiescent state as they did not enhance viral growth in Nd-PC12 cells; (v) viral alpha4 gene and host HSP72 gene transcription were rapidly induced in QIF-PC12 as soon as 3 h post-HS initiation; (vi) induction of the viral alpha27 gene followed that of representative beta and gamma genes, U(L)30 and U(L)18, respectively, and (vii) HS induced asynchronous HSV-1 replication from QIF-PC12 cells with 1:400 to 1:22000 positive foci detected as rapid as 24 h post-induction when established at MOIs of 30 and 3, respectively. These findings provide evidence that alpha4 may be involved in the switch from quiescence to productive infection. Furthermore, this model has the potential to advance our understanding of how HS initiates the HSV-1 productive cycle from a cryptic viral genome.

Animals↗
PubMed1998

Satisfaction with obstetric care: relation to neonatal intensive care.

OBJECTIVE: To examine the relationship between admitting children to a neonatal intensive care unit (NICU) and mothers' satisfaction with obstetric care. METHODS: Mothers of live-born infants who are now normal were interviewed about their perceptions of the interpersonal, organizational, and technical care they and their babies received during pregnancy, delivery, and the neonatal period, and their and their infants' health. Comparisons between the responses of mothers whose babies were admitted to the normal nursery (n = 595) and those whose babies were sent to an NICU (n = 72) were made by chi2 analysis (1 df) and Wilcoxon rank sum tests. RESULTS: Mothers whose babies were admitted to an NICU were more likely to complain that their obstetricians did not explain things in terms they could understand (P < .05); did not give them the right amount of information about what to expect during pregnancy (P < .05); hid something from them before delivery (P < .001); did not explain the reasons for tests performed during delivery (P < .05); misled them about their child's prognosis (P < .001); failed to treat properly a problem during delivery (P < .05); and did not know the latest medical developments (P < .05). CONCLUSION: Even when children do well, admission of newborns to an NICU is associated with greater maternal dissatisfaction with obstetric care.

Adult↗
PubMed1998

What health professionals can do to identify and resolve patient dissatisfaction.

BACKGROUND: Patient satisfaction affects consistency of self-care, health outcomes, level of service utilization, choice of health professionals, and decisions to sue in the face of adverse outcomes. Understanding patients' specific dissatisfactions may help health professionals and administrators identify and rectify organizational deficiencies before they become costly. COMMON CAUSES OF COMPLAINTS: As part of a series of research projects, more than 12,000 patient/family complaint narratives were examined in which patients or patients' family members told interviewers or patient advocates about the care they received from their health professionals in both inpatient and outpatient settings. Complaints may be categorized as involving issues of care and treatment, communication, humaneness, access and availability, environment, and billing/payment. STRATEGIES FOR RESOLVING COMPLAINTS: Even though caregivers may not have control over all the factors that lead to dissatisfaction, they can often hear and address complaints. As a result, they may not only contribute to quality of care but improve the systems in which they practice. The challenges are how to prevent dissatisfaction in the first place, and, if it does occur, to identify and if possible rectify patient concerns. Three case studies are provided. CONCLUSION: All health professionals must be involved in efforts to resolve problems that compromise patient care. Some problems could be prevented if administrators and leaders used complaint data to recommend new policies and procedures or to identify and counsel with health care team members who generate disproportionate numbers of complaints. If all are involved in both prevention and problem solving, resources devoted to uncovering, understanding, and resolving patient complaints are likely to prove cost-effective.

Attitude of Health Personnel↗
PubMed1998

Selective interference with pacemaker activity by electrical dental devices.

OBJECTIVE: We sought to determine whether electromagnetic interference with cardiac pacemakers occurs during the operation of contemporary electrical dental equipment. STUDY DESIGN: Fourteen electrical dental devices were tested in vitro for their ability to interfere with the function of two Medtronics cardiac pacemakers (one a dual-chamber, bipolar Thera 7942 pacemaker, the other a single-chamber, unipolar Minix 8340 pacemaker). Atrial and ventricular pacemaker output and electrocardiographic activity were monitored by means of telemetry with the use of a Medtronics 9760/90 programmer. RESULTS: Atrial and ventricular pacing were inhibited by electromagnetic interference produced by the electrosurgical unit up to a distance of 10 cm, by the ultrasonic bath cleaner up to 30 cm, and by the magnetorestrictive ultrasonic scalers up to 37.5 cm. In contrast, operation of the amalgamator, electric pulp tester, composite curing light, dental handpieces, electric toothbrush, microwave oven, dental chair and light, ENAC ultrasonic instrument, radiography unit, and sonic scaler did not alter pacing rate or rhythm. CONCLUSIONS: These results suggest that certain electrosurgical and ultrasonic instruments may produce deleterious effects in medically fragile patients with cardiac pacemakers.

Arrhythmias, Cardiac↗
PubMed1998

Molecular aspects of herpes simplex virus I latency, reactivation, and recurrence.

The application of molecular biology in the study of the pathogenesis of herpes simplex virus type 1 (HSV-1) has led to significant advances in our understanding of mechanisms that regulate virus behavior in sensory neurons and epithelial tissue. Such study has provided insight into the relationship of host and viral factors that regulate latency, reactivation, and recurrent disease. This review attempts to distill decades of information involving human, animal, and cell culture studies of HSV-1 with the goal of correlating molecular events with the clinical and laboratory behavior of the virus during latency, reactivation, and recurrent disease. The purpose of such an attempt is to acquaint the clinician/scientist with the current thinking in the field, and to provide key references upon which current opinions rest.

Animals↗
PubMed1997

Need and Demand for Oral Medicine Services in 1996. A report prepared by the Subcommittee on Need and Demand for Oral Medicine Services, a subcommittee of the Specialty Recognition Committee, American Academy of Oral Medicine.

The need and demand for oral medicine services in the United States and Canada was determined by a prospective survey of American Academy of Oral Medicine practitioners who attended the Academy's 1996 annual meeting. Of the 50 surveys returned from 149 eligible registrants, it was determined that, on the average, oral medicine practitioner respondents practiced 2.3 days per week and treated 8.7 patients per day; this amounts to more than 40,000 patient-care visits per year. Almost 90% of patients were treated because of medically compromising conditions, oral mucocutaneous disease, or chronic orofacial pain. Most of the care (52%) was provided in non-university settings. Most treatment involved the comprehensive evaluation of complex oral problems (36.7%), the prescription of medications (24.2%), or comprehensive dental treatment (21.8%) for patients with severe and life-threatening medical conditions. These results suggest that oral medicine services are needed and that demand for these services is high.

Adolescent↗
PubMed1997

Toxicant-induced loss of tolerance--an emerging theory of disease?

This paper attempts to clarify the nature of chemical sensitivity by proposing a theory of disease that unites the disparate clinical observations associated with the condition. Sensitivity to chemicals appears to be the consequence of a two-step process: loss of tolerance in susceptible persons following exposure to various toxicants, and subsequent triggering of symptoms by extremely small quantities of previously tolerated chemicals, drugs, foods, and food and drug combinations including caffeine and alcohol. Although chemical sensitivity may be the consequence of this process, a term that may more clearly describe the observed process is toxicant-induced loss of tolerance. Features of this yet-to-be-proven mechanism or theory of disease that affect the design of human exposure studies include the stimulatory and withdrawallike nature (resembling addiction) of symptoms reported by patients and masking. Masking, which may blunt or eliminate responses to chemical challenges, appears to have several components: apposition, which is the overlapping of the effects of closely timed exposures, acclimatization or habituation, and addiction. A number of human challenge studies in this area have concluded that there is no physiological basis for chemical sensitivity. However, these studies have failed to address the role of masking. To ensure reliable and reproducible responses to challenges, future studies in which subjects are evaluated in an environmental medical unit, a hospital-based facility in which background chemical exposures are reduced to the lowest levels practicable, may be necessary. A set of postulates is offered to determine whether there is a causal relationship between low-level chemical exposures and symptoms using an environmental medical unit.

Adaptation, Physiological↗
PubMed1996

Potential animal model of multiple chemical sensitivity with cholinergic supersensitivity.

Multiple Chemical Sensitivity (MCS) is a clinical phenomenon in which individuals, after acute or intermittent exposure to one or more chemicals, commonly organophosphate pesticides (OPs), become overly sensitive to a wide variety of chemically-unrelated compounds, which can include ethanol, caffeine and other psychotropic drugs. The Flinders Sensitive Line (FSL) rats were selectively bred to be more sensitive to the OP diisopropylfluorophosphate (DFP) compared to their control counterparts, the Flinders Resistant Line (FRL) rats. The present paper will summarize evidence which indicates that the FSL rats exhibit certain similarities to individuals with MCS. In addition to their greater sensitivity to DFP, the FSL rats are more sensitive to nicotine and the muscarinic agonists arecoline and oxotremorine, suggesting that the number of cholinergic receptors may be increased, a conclusion now supported by biochemical evidence. The FSL rats have also been found to exhibit enhanced responses to a variety of other drugs, including the serotonin agonists m-chlorophenylpiperazine and 8-OH-DPAT, the dopamine antagonist raclopride, the benzodiazepine diazepam, and ethanol. MCS patients report enhanced responses to many of these drugs, indicating some parallels between FSL rats and MCS patients. The FSL rats also exhibit reduced activity and appetite and increased REM sleep relative to their FRL controls. Because these behavioral features and the enhanced cholinergic responses are also observed in human depressives, the FSL rats have been proposed as a genetic animal model of depression. It has also been reported that MCS patients have a greater incidence of depression, both before and after onset of their chemical sensitivities, so cholinergic supersensitivity may be a state predisposing individuals to depressive disorders and/or MCS. Further exploration of the commonalities and differences between MCS patients, human depressives, and FSL rats will help to elucidate the mechanisms underlying MCS and could lead to diagnostic approaches and treatments beneficial to MCS patients.

Animals↗
PubMed1996

Chemical sensitivity: symptom, syndrome or mechanism for disease?

Several different meanings have been attached to the term "chemical sensitivity" by those who use it. Feeling ill from odors is a symptom reported by approximately one-third of the population. The syndrome of chemical sensitivity, frequently called "Multiple Chemical Sensitivity" or "MCS" has been the subject of three federally-sponsored workshops; at least five different case definitions for research on MCS have been proposed. In contrast, the hypothesis that chemical sensitivity may be a mechanism for disease posits that a broad spectrum of "recognized" chronic illnesses, ranging from asthma and migraine to depression and chronic fatigue, may be the consequence of environmental chemical exposures. According to this theory, a two-step process occurs: (1) an initial salient exposure event(s) (for example, a one-time, intermittent, or continuous exposure to pesticides, solvents, or air contaminants in a sick building) interacts with a susceptible individual, causing loss of tolerance for everyday, low level chemical inhalants (car exhaust, fragrances, cleaning agents), as well as for foods, drugs, alcohol, and caffeine; (2) thereafter, such common, formerly well-tolerated substances trigger symptoms, thus perpetuating illness. "Masking" (acclimatization, apposition, and addiction) may hide these exposure-symptom relationships, thus obfuscating the environmental etiology of the illness. Accumulating clinical observations lend credence to a view of chemical sensitivity as an emerging theory of disease causation and underscore the need for its testing in a rational, scientific manner. While chemical sensitivity may be the consequence of chemical exposure, the term "toxicant-induced loss of tolerance" more fully describes the two-step process under scrutiny.

Disease Susceptibility↗
PubMed1996

Viral infections in the immunocompetent patient.

Human herpesviruses and human papillomaviruses are ubiquitous and may cause an array of oral disease. Herpesviruses are unique because recurrent localized disease occurs after the primary infection. Human papillomaviruses are known for their ability to produce benign epithelial proliferations and increasingly are implicated in the development of oral cancer. This article reviews the pathogenesis of common oral lesions induced by these viruses.

Adult↗
PubMed1996

Human papillomavirus expression in oral mucosa, premalignant conditions, and squamous cell carcinoma: a retrospective review of the literature.

OBJECTIVES: The literature of human papillomavirus detection in normal oral mucosa and oral lesions associated with the dysplastic progression of epithelium was reviewed to help define the role of this virus in the development of oral squamous cell carcinoma. STUDY DESIGN: All available data from published studies were analyzed by chi-square test for association between the human papillomavirus and age, gender, race, DNA type, location, lesional dysplastic progression, method of detection, tissue preservation, and use of tobacco and alcohol. RESULTS: Human papillomavirus was identified with increasing frequency in normal oral mucosa (13.5%), benign leukoplakia (14.8%), intraepithelial neoplasia (18.5%), squamous carcinoma (26.2%), and verrucous carcinoma (27%). It was detected in oral squamous cell carcinoma significantly (p < 0.005) more often (37.1%; 122 of 329) in studies that used a high sensitivity assay (polymerase chain reaction) than studies that used moderate sensitivity assays (25.2%; 84 of 334) (e.g., Southern blot hybridization) and low sensitivity assays (16.9%; 61 of 362) (e.g., immunohistochemistry, in situ hybridization). Human papillomavirus DNA was detected significantly more often (p < 0.001) in frozen oral squamous cell carcinoma (51.6%; 115 of 223) than paraffin-embedded tissue (21.7%; 136 of 628). High-risk human papillomaviruses (2, 16, 18) were detected in 81.4% of OSCCs that contained the virus compared with low-risk human papillomavirus genotypes (6, 11) in 17.9% of oral squamous cell carcinoma that contained the human papillomavirus (p < 0.001). In studies that analyzed the use of chemical cofactors, the use of tobacco and alcohol (87.3%) was associated more often with oral squamous cell carcinoma than the presence of human papillomavirus (51.3%), however, the difference was not significant. CONCLUSION: High-risk human papillomavirus genotypes have a significant association with oral squamous cell carcinoma. However, the presence of this virus in a high proportion of oral normal mucosa makes the virus alone a poor prognosticator of progression to malignancy.

Adult↗
PubMed1995

Salivary cortisol response to dental treatment of varying stress.

The physiologic stress of various dental procedures (dental examination, dental prophylaxis, restoration, root canal therapy, and tooth extraction) was measured in 50 nonsmoking healthy men between the ages of 18 and 55 years (mean 34.6 years, range 21 to 53 years) with a salivary cortisol assay. Expectorated saliva was collected at four time points: 10 minutes before the start of the procedure, 15 minutes after the patient was seated, at the end of the procedure, and 1 hour after the completion of the procedure. Of the 196 samples included for analysis, mean cortisol values ranged from 0.1 to 3.8 micrograms/dl with a recovery of 100% +/- 8.4%. The mean cortisol value for the extraction group (1.09 +/- 0.42 microgram/dl) was significantly different (p < 0.05) from the mean values of the examination (0.46 +/- 0.10 microgram/dl), prophylaxis (0.64 +/- 0.64 microgram/dl), root canal (0.49 +/- 0.07 microgram/dl), and restorative (0.60 +/- 0.04 microgram/dl) groups as determined by the Duncan's multiple range test. Cortisol levels decreased from the initial reading to the end of the procedure by about 15% for patients undergoing an examination, root canal, and restorative procedure. Cortisol levels at the end of the procedure were elevated in the prophylaxis (55%) and extraction (148%) groups compared with the baseline cortisol recording. A minority of patients in the prophylaxis group had elevated cortisol levels throughout dental treatment, whereas cortisol levels were elevated during treatment in 80% of patients undergoing extraction. These data suggest that the adrenal stress response associated with tooth extraction(s) is greater than that associated with other routine dental procedures.

Adolescent↗