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Biomedical subjects

C H Miller

Publications and source records attributed to C H Miller.

At least 19 recordsLinked to original sources
PubMed1992

Differential increases of neurokinin B- and enkephalin-like immunoreactivities and their mRNAs after chronic haloperidol treatment in the rat.

Changes in neurokinin B-like immunoreactivity (NKB-IR) and neurokinin B mRNA were investigated after daily injection of haloperidol for 10 days on adjacent sections by means of immunocytochemistry and in situ hybridization in the caudate putamen of the rat. In the dorsal striatum the number of NKB immunoreactive perikarya and the staining intensity of striatal efferents increased. The number of NKB mRNA-expressing cells (45%) and the grain density over single positive cells (37%) were significantly higher after the neuroleptic treatment. The levels for enkephalin mRNA were uniformly increased throughout the rostrocaudal extent of the caudate putamen (85%). A main difference to the enkephalin system was that the dorsal pallidum was nearly devoid of NKB-IR in untreated as well as in haloperidol-treated animals. The present data for the first time provide evidence for the regulation of the biosynthesis of NKB after pharmacological intervention.

Animals↗
PubMed1992

Inhibition of microbial adherence and growth by various glass ionomers in vitro.

This study measured the in vitro inhibition of growth and adherence of five oral bacteria by glass-ionomer materials. Disks were prepared from two cavity liners and four restorative class materials, by use of Teflon plates with circular wells, five mm wide and two mm deep. The bacterial species tested included: A. viscosus, S. mitis, S. mutans, L. casei, and S. sanguis. Growth inhibition studies were performed by the spreading of 0.1 mL of standardized inocula over agar plates produced with selective media, followed by the direct application of glass-ionomer disks onto the agar. On other plates, disks were placed onto uninoculated agars for 48 h, followed by bacterial inoculation. All agar plates were incubated under optimal growth conditions for each bacterial species. The four restorative materials were also placed aseptically into sterilized bovine incisors and placed into sucrose containing broth media, inoculated with S. mutans for three days. Adhering materials were disclosed and scored. An ion-exchange electrode was used to measure fluoride release over a seven-day period for all six glass ionomers. The two cavity liners and two of the restorative materials produced the largest growth inhibition zones by direct contact. No growth inhibition occurred when the specimens were allowed to come into contact with the agars prior to inoculation. All four restorative materials reduced bacterial accumulations on enamel surfaces by over 80%. Elevations in short-term fluoride release levels were positively correlated with growth inhibition.

Actinomyces viscosus↗
PubMed1992

Tamm-Horsfall protein as a marker in interstitial cystitis.

It has been suggested that immunohistochemical staining for Tamm-Horsfall protein in bladder epithelium may be a marker for interstitial cystitis. Of bladder biopsies from 14 interstitial cystitis patients only 3 demonstrated positive staining for Tamm-Horsfall protein within the mucosa, whereas 2 of 11 control biopsies showed positive Tamm-Horsfall protein results. In addition, staining in 4 ureteral specimens from interstitial cystitis patients and 4 controls was negative in all cases. An effort to detect this protein in enterocystoplasty specimens also showed a negative pattern. Our study does not confirm the Tamm-Horsfall protein as permeating either the bladder epithelium in interstitial cystitis or bowel mucosa in enterocystoplasty. This finding does not necessarily mean that these surfaces are not permeable to substances of smaller molecular size, nor does it define whether this is of importance in the etiology of interstitial cystitis. However, it does suggest that this technique does not allow detection of a marker for the disease.

Adult↗
PubMed1992

Lymphocyte function in patients with interstitial cystitis.

To determine whether there is a primary immunological disorder involved in the etiology of interstitial cystitis, we compared the in vitro function of peripheral blood lymphocytes from 10 patients with interstitial cystitis to those from 10 healthy female controls. The lymphocytes were isolated and incubated in either cell culture medium alone, cell culture medium supplemented with the mitogen phytohemagglutinin or cell culture medium with autologous sterile filtered urine, the latter to detect any immunogenic potential of urine in this disease. We studied the relative proliferation of the phenotypes CD2, CD4, CD8, CD19, CD14 and CD56 by immunofluorescence and flow cytometry. To detect activation of T lymphocytes we also studied expression of HLA-Dr and interleukin-2 receptors. There was no difference in the rate of proliferation of the various lymphocyte phenotypes between the 2 groups in any of the culture media. Similarly, there was no difference between the 2 groups in the degree of lymphocytic activation after incubation. Furthermore, incubation in the presence of autologous urine caused no increase in activation above that seen in control cultures. We also assessed the production of the lymphokines interleukin-1, interleukin-2 and interferon-gamma in the supernatant fluid of the cell cultures. There was no difference in the production of these immunoregulatory cytokines between the control and patient groups, and again urine did not act as a mitogen in either group. We conclude from this study that there is no primary immunological disorder evident in patients with interstitial cystitis, and that the urine does not act as a stimulant to the immune system. This finding casts severe doubt on any theory suggesting that interstitial cystitis is an autoimmune disease or that urine contains an autoantigen causing the disease.

Adult↗
PubMed1992

Impairment of helper T-cell function following severe head injury.

Major infections, such as sepsis and pneumonia, occur in 50-75% of patients following isolated severe head injury. Previous studies have demonstrated that this high incidence of infection following severe head injury may be related to a decrease in helper T-cell activation and function. The present study was designed to investigate the effect of severe head injury on specific subgroups of helper T cells known to enhance or suppress cellular immune function. Specifically, peripheral blood lymphocytes (PBLs) from 10 head-injured patients and 10 matched controls were evaluated following in vitro stimulation with the T-cell mitogen, phytohemagglutinin (PHA). Subsets of helper T cells evaluated included activated helper (CD4+/CD25+) T cells; helper/inducer (CD4+/CDw29+) T cells, which enhance cellular immune activity; and suppressor/inducer (CD4+/CD45R+) T-cells, which induce suppressor (CD8+) T-cells. In addition, the effect of intraventricular fluid (IVF) on PHA-stimulated in vitro CD4 and CD25 expression was investigated to determine whether severe head injury results in the production of mediators within the central nervous system capable of affecting T-cell activation. The results of this study indicate that isolated severe head injury selectively reduces the ability of PHA-stimulated PBLs to express the helper/inducer (CD4+/CDw29+) T-cell (p = 0.023) and activated helper (CD4+/CD25+) T-cell (P = 0.041) phenotypes. There was no significant change in PHA-stimulated CD4 or CD25 expression following incubation of PBLs with intraventricular fluid (IVF) from head-injured patients. The relationship between these changes in specific helper T-cell subpopulations and the infectious complications of severe head injury are discussed.

Adolescent↗
PubMed1992

The effects of alcohol and benzodiazepines on the severity of ski accidents.

Urine samples from 402 victims of ski accidents were analyzed for the presence of benzodiazepines (BZD) and alcohol. Eighty-one (20%) samples were positive for alcohol; BZD were detected in 34 (8.5%) cases. Ten of the samples (2.5%) were found to be positive for both alcohol and BZD. Subjects who were positive for either alcohol or BZD or both were older than the other persons examined. The prevalence of alcohol was significantly higher among male accident victims. BZD intake could be demonstrated to have a significant influence on the severity of injuries. Besides an increased awareness of the need for skier education regarding drug use, heightened attention of medical caregivers is warranted to inform their patients about potential accident hazards in sport activities when BZD are prescribed.

Adolescent↗
PubMed1992

Sterilization and disinfection: what every dentist needs to know.

This paper reviews infection control procedures with the related regulations and recommendations. Procedures for processing contaminated instruments include presoaking, cleaning, packaging, sterilization, spore-testing and hand-piece asepsis. Surface asepsis techniques include surface covering, surface precleaning and surface disinfection.

Dental High-Speed Equipment↗
PubMed1992

Cell-mediated immunity in severely head-injured patients: the role of suppressor lymphocytes and serum factors.

Severe head injury results in suppression of cellular immunity associated with defective in vitro functioning of effector lymphocytes, such as helper T cells and cytotoxic T cells. It is not known whether this suppression in effector lymphocyte function is due to intrinsic lymphocyte dysfunction, to suppressor peripheral blood mononuclear cells (PBMC's) such as suppressor lymphocytes or suppressor monocytes, or to serum factors capable of inhibiting effector lymphocyte function. The purpose of this study was to determine whether a subpopulation of PBMC's and/or serum factor(s) are responsible for this observed suppression in cell-mediated immunity. Cell-mediated immune activity was determined measuring in vitro lymphokine-activated killer (LAK) cytotoxicity following incubation of PBMC's from 15 head-injured patients with those from 15 heterologous normal subjects. The PBMC's were separated into lymphocyte-enriched and monocyte-enriched subpopulations by plastic adherence techniques, and the effect of each population on LAK cytotoxicity was determined. Additionally, the effect on cytotoxicity of serum from the head-injured patients was determined in a dose-response fashion. There was significant depression in LAK cytotoxicity when: 1) PBMC's from normal subjects were incubated with PBMC's from head-injured patients (p < 0.001); 2) lymphocytes (PBMC's depleted of monocytes) from head-injured patients were incubated with PBMC's from normal subjects (p < 0.001); and 3) PBMC's from normal subjects were incubated with serum from head-injured patients (p < 0.001). No suppression in cellular immunity was noted when lymphocytes from normal subjects were incubated with monocytes from head-injured patients. The results indicate that lymphocytes rather than monocytes actively inhibit cellular immunity following severe head injury. The detection of immunosuppressive serum factors suggests a mechanism by which lymphocytes might be modulated by severe head injury.

Adolescent↗
PubMed1991

Alteration in age-specific risks for chromosomal trisomy by maternal serum alpha-fetoprotein and human chorionic gonadotropin screening.

Maternal serum screening for alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG) increases the detection rate of Down's syndrome (DS) pregnancies. To estimate the risk of a DS pregnancy for a particular woman, Wald et al. combine a trivariate function of AFP, hCG, and unconjugated oestriol with age-specific risk. Calculation of independent likelihood ratios (LRs) for AFP and hCG has allowed us to examine the predictive value of each test alone and the combination. AFP and hCG were measured in stored serum samples from 672 normal, 8 trisomy 21 (DS), 9 trisomy 18, and 2 trisomy 13 pregnancies. AFP and hCG multiples of the median (MOM) were calculated for each sample. The LRs for AFP MOM and hCG MOM were calculated and combined with age-specific risk. Of eight DS pregnancies, six had increased risk based on age and AFP. Addition of hCG detected two additional DS pregnancies. Of nine trisomy 18 pregnancies, four (44 per cent) had hCG MOM under 0.25. Three out of nine would have been classified as high risk by AFP, but none by combined AFP and hCG. Amniocentesis would have been recommended in 74 per cent of aneuploid pregnancies if both age and serum screening were used. Abandonment of amniocentesis based on age alone would have excluded two abnormal pregnancies from detection. Screening programmes should note that combined risk figures are specific for DS and do not include other trisomies. Detection of other trisomies requires inclusion of low hCG level as a discriminator and continuation of age-based testing.

Age Factors↗
PubMed1991

The Hillside Akathisia Scale: a reliability comparison of the English and German versions.

Akathisia usually consists of two components, subjective restlessness and typical movements such as shuffling of the legs, pacing, shifting weight from one leg to the other, and rocking movements of the trunk. The ability to measure akathisia reliably is essential for the assessment of treatments for akathisia and for the evaluation of drug-induced side effects in general. To date, investigators have generally used self-constructed assessment scales without reporting data about reliability or validity. The Hillside Akathisia Scale (HAS) has two subjective and three objective items for which anchored rating points are provided. Reliability was 0.89 for the HAS total score. Reliability for rating subjective symptoms ranged from 0.86 to 0.92, and the objective scores ranged from 0.51 to 0.89. The correlation between HAS and a global assessment of akathisia (modified CGI) was 0.87. These values compare favorably with the original report on the scale indicating that the Hillside Akathisia Scale can validly quantify akathisia with a satisfactory degree of interrater reliability.

Adult↗
PubMed1991

The comparative antimicrobial effect of calcium hydroxide.

The antimicrobial effectiveness of calcium hydroxide, camphorated paramonochlorophenol, and formocresol in root canals of extracted human teeth was compared. Canals in single-rooted teeth were enlarged and inoculated with Streptococcus mutans, Actinomyces viscosus, and Bacteroides gingivalis or Bacteroides fragilis. After treatment with a test agent and sealing and incubation for 1 hour, the canal contents were analyzed for the number of viable test bacteria and compared with that of inoculated teeth not treated with test agents. All test agents exhibited antimicrobial activity against all bacteria, with percent reductions in viable bacteria ranging from 64.3% to 100%. The combined data for Pulpdent paste and calcium hydroxide showed significantly higher antimicrobial activity than the combined data for camphorated paramonochlorophenol and formocresol for S. mutans and B. gingivalis or B. fragilis but showed no difference for A. viscosus.

Actinomyces↗
PubMed1991

The effect of sucralfate on the growth of cariogenic streptococci.

Sucralfate, an aluminum salt of sucrose octasulfate, has been shown to be effective in reducing the discomfort of radiation therapy-induced oral mucositis. This study was done to determine whether sucralfate could be used as a nutritional source for dental caries-producing organisms. Three Streptococcus strains were cultured in a defined medium. Sucralfate powder was evaluated for its ability to be used as a carbohydrate food source by these organisms. The addition of sucralfate alone did not stimulate the organism's growth. The addition of sucralfate and glucose resulted in less growth than the addition of glucose alone. Increasing the sucralfate concentration from 1% to 10% in the glucose-containing cultures resulted in statistically significant growth inhibition (p less than 0.02). Sucralfate appears to have no cariogenic potential and may have some cariostatic potential.

Colony Count, Microbial↗
PubMed1991

Cellular immunity in interstitial cystitis.

It has been suggested that interstitial cystitis is an autoimmune disease. The evidence for this hypothesis, based on studies of humoral immune factors, has been contradictory. We assessed the immune response in interstitial cystitis by evaluating lymphocyte populations in the peripheral blood and bladder tissue of interstitial cystitis patients. The lymphocyte phenotypes in peripheral blood were entirely normal, including the CD4 (cluster designation nomenclature) and CD8 subsets, and the CD4:CD8 ratio. Bladder lamina propria showed a predominance of CD4 over CD8 lymphocytes in interstitial and other forms of cystitis. Bladder epithelium showed a similar pattern in bacterial or mechanical cystitis but specimens from patients with interstitial cystitis had a predominance of CD8 cells. The findings of normal lymphocyte populations in the peripheral blood are not supportive of an autoimmune mechanism in the disease. The findings in bladder tissue show that the urothelium is not involved in the inflammatory reaction, as is the lamina propria, and they would suggest, therefore, that the initiating factor does not originate from the bladder lumen. The CD8 predominance in the urothelium along with a CD4 predominance in the lamina propria may form a characteristic pattern for the diagnosis of interstitial cystitis and merits further study.

Adult↗
PubMed1991

Severe head injury: effect upon cellular immune function.

Infection is a major cause of morbidity following severe head injury. Although investigations have demonstrated central nervous system modulation of immune function, the effects of severe head injury on immune activity have not been well documented. This study prospectively investigated cellular immune function in 20 patients with isolated severe head injury. In vivo cellular immune status was determined by responses to delayed-type hypersensitivity (DTH) skin tests. In vitro studies included the effect of the lymphocyte mitogen, phytohaemagglutinin (PHA), on peripheral blood lymphocyte (PBL) phenotype expression and PBL blastogenesis. DTH skin testing demonstrated anergy to all antigens used during the first two weeks following head injury. Analysis of PBLs incubated with PHA demonstrated a decrease in the percent of PBL blastogenesis (p = 0.002), the percentage of cells marking as T-cells (p = 0.018), helper T-cells (p less than 0.001) and those expressing interleukin-2 receptors (p less than 0.001). There was a significant increase in the percentage of cells that marked as monocytes (p = 0.030), whereas there was no significant change in the percentage of B-cells, suppressor/cytotoxic T-cells, natural killer cells or in cells expressing the HLA-DR antigen. The infection rate was 55% with most occurring within 5 days of injury. The results of this study suggest that isolated severe head injury causes suppression of cellular immunity. The decrease in PHA stimulated PBL blastogenesis, helper T-cell phenotypic and interleukin-2 receptor expression, suggests suppression in early helper T-cell activation may be responsible for the high incidence of infection following severe head injury. The possible significance of increased monocyte phenotypic expression is discussed.

Adolescent↗
PubMed1991

Humoral and cellular immunity following severe head injury: review and current investigations.

Infection is a common and serious complication of severe head injury. Immunocompetence in 25 severely head injured patients was investigated by measuring: (1) delayed-type hypersensitivity (DTH) skin test responses to common antigens; (2) phytohaemagglutinin (PHA) stimulated peripheral blood lymphocyte (PBL): blastogenesis, phenotype expression, and lymphokine production; (3) lymphokine-activated killer (LAK) cytotoxicity, antibody dependent cellular cytotoxicity (ADCC) and natural killer (NK) cytotoxicity; and (4) immunoglobulin and complement levels. The incidence of anergy to DTH skin testing was 100%. There was a decrease in PHA stimulated: PBL blastogenesis (p = 0.002), T-cell expression (p = 0.018), helper T-cell expression (p less than 0.001), interleukin-2 receptor expression (p less than 0.001), interleukin-2 production (p = 0.035) and gamma-interferon production (p less than 0.001). LAK cytotoxicity was depressed following incubation with IL-2 (p less than 0.001). There was no significant decrease in immunoglobulin levels and all acute phase reactants tested increased. The results of this study indicate that the cellular arm of immune response, including lymphocyte activation and cytokine production, is suppressed following severe head injury. The lack of enhancement in LAK cytotoxicity following incubation of PBLs with interleukin-2 suggests that factors other than decreased interleukin-2 production, such as the inherent lymphocyte dysfunction, other soluble mediators or suppressor cells, may be responsible for the reduction in cellular immunity observed following severe head injury.

Adolescent↗
PubMed1991

A microbiological comparison of young adults based on relative amounts of subgingival calculus.

This study compared the relative amounts of Actinobacillus actinomycetemcomitans (Aa), Eikenella corrodens (Ec), and black-pigmented anaerobic rods, and the proportions of coccoid forms, nonmotile rods, motile rods, spirochetes, and total motile organisms in subgingival plaque samples from 2 groups of young adults with generalized moderate to severe periodontitis. Two groups of 12 untreated patients were selected based on the relative amounts of subgingival calculus detected. Subgingival plaque samples (2 sites/patient) were taken with a sterile curet, dispersed, and plated under anaerobic conditions on ETSA, ETSA-kanamycin, ETSA-clindamycin, and TSBV agar. Appropriate biochemical tests were performed to confirm suspected microorganisms. Phase-contrast microscopy also was used to count the relative numbers of coccoid forms, nonmotile rods, motile rods, and spirochetes in each of the samples. Patients with no clinically detectable subgingival calculus harbored significantly greater proportions (%) of coccoid forms and Aa and greater amounts (CFU/mg) of Aa than did patients with obvious amounts of subgingival calculus. Subjects with clearly detectable subgingival calculus possessed greater proportions of motile rods, total motile organisms, and black-pigmented anaerobic rods than did subjects with little or no subgingival calculus. Young adult patients with generalized moderate to severe disease and little or no detectable subgingival calculus may possess a subgingival microbiota with relatively higher numbers of Aa and coccoid forms, and a lower percentage of BPB, motile rods, and total motile organisms as compared to similar patients with greater amounts of subgingival calculus.

Adult↗
PubMed1991

Impairment of helper T-cell function and lymphokine-activated killer cytotoxicity following severe head injury.

Infection is a major complication of severe head injury, occurring in 50% to 75% of patients who survive to hospitalization. Previous investigations of immune activity following head injury have demonstrated suppression of helper T-cell activation. In this study, the in vitro production of interferon-gamma (INF-gamma), interleukin-1 (IL-1), and interleukin-2 (IL-2) was determined in 25 head-injured patients following incubation of peripheral blood lymphocytes (PBL's) with the lymphocyte mitogen phytohemagglutin (PHA). In order to elucidate the functional status of cellular cytotoxicity, lymphokine-activated killer (LAK) cell cytotoxicity assays were performed both prior to and following incubation of PBL's with IL-2 in five patients with severe head injury. The production of INF-gamma and IL-2 by PHA-stimulated PBL's was maximally depressed within 24 hours of injury (p less than 0.001 for INF-gamma, p = 0.035 for IL-2) and partially normalized within 21 days of injury. There was no change in the production of IL-1. When comparing the in vitro LAK cell cytotoxicity of PBL's from head-injured patients and normal subjects, there was a significant depression in LAK cell cytotoxicity both prior to (p = 0.010) and following (p less than 0.001) incubation of PBL's with IL-2. The results of this study indicate that IL-2 and INF-gamma production, normally required for inducing cell-mediated immunity, is suppressed following severe head injury. The failure of IL-2 to enhance LAK cell cytotoxicity suggest that factors other than decreased IL-2 production, such as inhibitory soluble mediators or suppressor lymphocytes, may be responsible for the reduction in cellular immune activity following severe head injury. These findings may have significant implications in designing clinical studies aimed at reducing the incidence of infection following severe head injury.

Adolescent↗