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Biomedical subjects

C H Miller

Publications and source records attributed to C H Miller.

At least 91 records · Page 5Linked to original sources
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↗
PubMed1991

Sterilization beneath rings on dental instruments.

This study determined the effectiveness of standard methods of instrument sterilization beneath instrument rings. Sets of three types of dental instruments were contaminated with known amounts of bacterial spores (Bacillus stearothermophilus or Bacillus subtilis). Instrument rings were placed over the contamination and the instruments processed through standard cycles in a steam autoclave, an unsaturated chemical vapor sterilizer, a standard dry heat sterilizer, an ethylene oxide gas sterilizer or a 2.0% alkaline glutaraldehyde solution. Controls consisted of spore-contaminated instruments without rings that were not processed through any sterilizing method and that were processed through each sterilizing method. All instruments and their associated rings were cultured for the presence of live spores. The results indicate that the reliability of sterilization beneath the instrument rings used is greatest if the ringed instruments are processed through a steam autoclave or an unsaturated chemical vapor sterilizer.

Bacillus subtilis↗
PubMed1991

Vulnerable phases in adolescence represented by means of committed suicide.

This study deals with suicides of children and adolescents in the region of Tyrol, Austria from 1976-1984. The upper age limit was set at 19 years. During the time period stated above, 54 suicides were registered for the relevant age group, using police records as a source of information. Special attention was paid to the distribution of age, sex and occupation, as well as to the suicide methods. As far as age distribution is concerned, a significant increase of suicides was registered at the age of 15 and again at the age of 19. According to the authors, the reason for this increase is pronounced psychosocial changes which occur especially in these age groups and weaken social integration. The various implications ensuing from the available data are discussed.

Adaptation, Psychological↗
PubMed1991

Sterilization. Disciplined microbial control.

The goal of instrument processing is to protect patients by preventing cross-contamination from instruments. The processing involves a series of sequential steps aimed at removing and killing microbes on contaminated instruments and maintaining those instruments in an aseptic state until they are reused. These steps must be conducted carefully to assure success and to reduce chances of disease spread or physical injury to those handling the contaminated instruments. Presoaking begins the cleaning process and facilitates terminal cleaning by ultrasonic or manual scrubbing. If instruments are not properly cleaned, subsequent sterilization may be jeopardized by insulation of blood- or saliva-coated microbes from the sterilizing agent. Items that would be destroyed by heat should be cleaned and sterilized in a properly prepared glutaraldehyde solution. Cleaned instruments must be packaged prior to heat sterilization to protect them from recontamination after sterilization and before reuse. Sterilization of cleaned, packaged instruments in steam, chemical vapor, or dry heat sterilizers must involve proper loading, processing, drying, and cooling. Routine use of spore tests and chemical indicators will provide quality assessment of packaging procedures and operation of the sterilizer, as well as assist in identifying processed packages during distribution. Using the results of sterilization monitoring to adjust procedures as a means of assuring sterilization provides quality assurance to the office staff and to the patients that the instruments have been properly processed. Carefully handling storage and distribution of the sterilized instrument packs or trays reduces the chances for recontamination until the instruments are reused. Instrument processing is a major part of the office infection control program. It must be performed in a controlled manner with proper monitoring to achieve the desired outcome of patient protection.

Dental Instruments↗
PubMed1990

[Compulsory admission and detention at psychiatric hospitals in Tirol--a frequency analysis of 11 years].

Freedom and compulsion are burning questions in psychiatry, and often unsatisfactorily resolved. In this paper general aspects are discussed in the light of data obtained at the Innsbruck University Department of Psychiatry and the Mental State Hospital of Hall in Tyrol. From 1976 to 1986 364 (1.99%) patients required compulsory admission following certification by police (or civil service) doctors out of 18,207 admissions to the University Department of Psychiatry over this 11-year period. Of these patients 90 had to be jugded by a court commission with regard to further compulsory hospitalization. Most frequent reasons for compulsory admission were alcohol-related psychiatric diseases in men and endogenous psychoses in women. The data collected at the University Department are compared with the situation in the Mental State Hospital of Hall in Tyrol. Results are discussed in the light of recent literature.

Adolescent↗
PubMed1990

Sterilization of orthodontic instruments and bands in cassettes.

The purpose of this study was to determine whether orthodontic instruments and bands contaminated with blood or saliva and bacterial spores can be heat sterilized while contained in OMS-ASAPsys instrument and band cassettes. Hinged and nonhinged instruments and bands were contaminated and dried, placed in the cassettes, ultrasonically cleaned, rinsed, and dried. The cassettes were wrapped and then processed through standard steam, chemical vapor, or dry-heat sterilizing cycles. Each instrument and band was then cultured for the presence of live spores. The results showed that the residual spores on the instruments and bands after ultrasonic cleaning and rinsing had indeed been killed in all cases. The three types of sterilization were equally effective. The results indicate that contaminated orthodontic instruments and bands can be sterilized within OMS-ASAPsys cassettes.

Blood↗
PubMed1990

Suppression of cellular immune activity following severe head injury.

Infection is a major cause of morbidity following multiple traumatic and head injury. Although immunosuppression has been demonstrated after multiple traumatic injury, the effects of head injury on immune function have not been thoroughly investigated. In a prospective study of 10 severely head-injured patients, in vitro and in vivo parameters of cellular immune activity were assessed. In vitro measurements of lymphocyte surface antigen expression following mitogen stimulation were made serially over a 3-week period in 10 patients with severe head injury. The control group consisted of 20 healthy subjects. Phenotyping of peripheral blood lymphocytes (PBLs) was performed following incubation with and without mitogens. Phenotypes were determined by flow cytometry using monoclonal antibodies (MABs) to T lymphocyte subsets and the alpha subunit of interleukin 2 (IL-2) receptors. In vivo cellular immune function was determined by measuring patient responses to delayed-type hypersensitivity (DTH) skin testing within 24 h of injury. When head-injured patients were compared to controls, PBLs incubated in the presence of phytohemagglutinin (PHA) demonstrated a decrease in cells marking as T cells (p = 0.005), helper-inducer T cells (p = 0.001), and in the number of IL-2 receptor-bearing cells (p = 0.001). The functional ability of these lymphocyte subpopulations to proliferate in the presence of PHA was significantly suppressed within 24 h of injury and normalized within 3 weeks of injury. DTH skin testing to Candida, mumps, trichophyton, and PPD antigens was performed within 24 h of injury and resulted in anergic responses in all 10 patients when measured at 24, 48, and 72 h following administration. The overall infection rate was 60%, with the majority of infections occurring within the first 4 days following injury. The results of this study indicate that severe head injury results in suppression of cellular immune function with a corresponding high rate of infection. The possible significance of the decrease in the percentage of helper-inducer T cells and in the number of cells bearing IL-2 receptors following mitogen stimulation is discussed.

Adolescent↗
PubMed1990

Carbamazepine monotherapy in the treatment of alcohol withdrawal.

More than 135 different strategies for medical treatment have been described for the treatment of alcohol withdrawal syndromes. The substances used most frequently (benzodiazepines, barbiturates, or clomethiazol) themselves pose some risk for abuse or addiction. Anticonvulsants, especially carbamazepine (CBZ), have been discussed for the treatment of alcohol withdrawal since the early seventies. Various studies report favourable results with CBZ, usually combined with sedative agents. Nineteen out-patients and 19 in-patients took part in an open study of CBZ in alcohol withdrawal. The dose of CBZ was adjusted individually and ranged from a mean dose of 761 mg on day 1 to 616 mg on day 3 and to 388 mg on day 7 in the group of out-patients, and from 789 mg on day 1, 694 mg on day 3 to 562 mg on day 7 in the sample of in-patients. The "Objective Clinical Scale in Assessment and Measurement of Alcohol Withdrawal" (OCSAMAW) was used for treatment evaluation. Statistical analysis showed a significant improvement on the 5%-level in both groups; four in-patients needed concomitant treatment with oxazepam. Nausea and pruritus were the most common side-effects of CBZ treatment.

Adult↗
PubMed1990

Treatment of neuroleptic induced akathisia with the 5-HT2 antagonist ritanserin.

Akathisia is a frequent and distressing side effect of antipsychotic medication. Little is known about its pathophysiology. Treatment trials of serotonin antagonists in Parkinson's disease and neuroleptic-induced Parkinsonism have been disappointing, with the possible exception of akathisia which has been reported to respond favorably to ritanserin. We report first results of a single-blind trial of ritanserin in the treatment of neuroleptic-induced akathisia. Ten patients received a mean dose of 13.5 mg/day (SD +/- 5.8) ritanserin for 2 to 4 days. Treatment response was assessed by the Hillside Akathisia Scale (HAS). HAS baseline ratings were 16.4 (+/- 6). After 3 days of treatment, these values dropped to 7.4 (+/- 5.2). This amelioration was statistically significant (p = .0069 matched-pairs signed rank test). Two patients did not respond. These results, although preliminary in nature, are encouraging and warrant further studies.

Administration, Oral↗
PubMed1990

Effectiveness of steam autoclaving on the contents of sharps containers.

The effectiveness of steam autoclaving on bacterial endospores placed within five types of sharps containers was tested. A variety of container physical orientations within the autoclave were evaluated. Spores were present on commercial spore strips or placed onto capped and uncapped dental needles. All strips and needles present in empty or filled containers could be sterilized within 15 minutes when the containers were placed on their sides and their vents left open. The contents of containers processed in an upward position required between 30-60 minutes of autoclaving before being sterilized. The size and shape of the containers influenced ease of sterilization.

Dental Instruments↗
PubMed1989

Intradermal inoculation with Heptavax-B. Immune response and histologic evaluation of injection sites.

The high cost of hepatitis B vaccine has limited its widespread use. Low-dose, intradermal injections of vaccine represent one option for reducing the cost. In this study, 92 nonimmune medical students were given three 0.1-mL intradermal injections of Heptavax-B containing 2 micrograms of hepatitis B surface antigen (HBsAg) at 0, 1, and 6 months. By 6 months, 90% of the subjects had developed protective levels of antibody to HBsAg (greater than or equal to 10 mIU/mL). Follow-up at 1 year showed a geometric mean concentration of antibodies to HBsAg of 396 mIU/mL for the group, and 95% had levels of antibody to HBsAg greater than or equal to 10 mIU/mL. A level of antibody to HBsAg of greater than 100 mIU/mL also was observed in more than 75% of subjects. Side effects included induration of the inoculation site in 18% at 6 months, which disappeared by 12 months, and macules that persisted at 1 year in 63%. The administration of hepatitis B vaccine intradermally is an attractive, low-cost alternative in the United States, where universal vaccination of preschool children or adolescents is being contemplated, and where booster doses are being considered.

Adult↗