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Biomedical subjects

S D Johnson

Publications and source records attributed to S D Johnson.

At least 19 recordsLinked to original sources
PubMed1995

Basal cell carcinoma and lifestyle characteristics.

BACKGROUND: A number of lifestyle factors are important in the etiology of basal cell carcinoma. Previous studies have investigated smoking, alcohol, diet, and sun exposure as possible contributing factors. No previous studies have investigated case-controlled lifestyle influences in basal cell carcinomas referred for Mohs micrographic surgery. METHODS: Cases were obtained from Mohs-referred basal cell carcinoma patients. Matched controls were selected from a busy dermatology clinic. The only criteria for selection of controls was never having had cancer previously. Cases and controls were surveyed regarding lifestyle characteristics. RESULTS: Forty-six age, sex, and skintype-matched controls were compared. Sun exposure, alcohol, and smoking were not significant factors. Dietary fat, fiber, and the vitamins A, C, and beta carotene, as well as selenium showed important, but not significant differences. Caffeine consumption was higher in the cancer group. CONCLUSIONS: Our findings agree with previously published studies in regard to antioxidant consumption as a protective factor for basal cell carcinoma. Caffeine consumption was higher in the cancer patients.

Aged↗
PubMed1995

Animal rights activism and animal welfare concerns in the academic setting: levels of activism and the perceived importance of research with animals.

Past research suggests that public support for the use of animal models as means to improve the human condition is present but many individuals have expressed ambivalence. In the present study, various sectors of the academic community (students and faculty) as well as the general population, were surveyed to assess their positions on the need for, and value of animal research, the value of psychological research in which animals are employed, and the respondents' consummatory habits. The results suggested that more information needs to be provided about the role of animal experimentation, including a discussion of the benefits produced by using animals to answer psychological questions.

Adolescent↗
PubMed1995

Model of factors related to tendencies to discriminate against people with AIDS.

This study was done to integrate previous work on discriminatory tendencies against those who have AIDS and the possible role of two new variables, perceived responsibility and God's retribution. Using interview data from 205 randomly selected respondents from "Middletown" (Muncie, Indiana), an empirical model was developed. Ratings on homosexual intolerance had the biggest influence on tendencies toward discrimination against AIDS. This type of intolerance was confirmed as a part of a traditional and politically conservative perspective in which the ideas that those with AIDS are responsible for their predicament and God punishes those who sin play an important role.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Biocompatibility studies on plasma polymerized interface materials encompassing both hydrophobic and hydrophilic surfaces.

The biocompatibility of radiofrequency plasma polymerized films (less than 100 nm thick) deposited on biomedical polymer supports has been characterized by in vitro and in vivo methods. The polymer interface materials covered a wide range of elemental composition and surface properties, and were prepared from N-vinyl-2-pyrrolidone, gamma-butyrolactone, n-hexane, and hexamethyldisilazane (PPHMDSZ). The biocompatibility studies showed that the interface materials were noncytotoxic to mouse and human fibroblasts, as shown by morphologic evaluation, and by determination of extracellular LDH; and they did not stimulate interleukin-1-like production from human monocytes, as indicated by a thymocyte proliferation assay. The human fibroblast proliferation assay showed that three of the polymers supported cell growth at levels comparable to, or greater than, polymer controls, while the hydrophobic PPHMDSZ inhibited both cell attachment and proliferation. The response to subcutaneous implantation for all test materials was indicative of biocompatibility, with rapid resolution of the acute phase response and normal wound healing. The wide range of composition and surface properties for the plasma polymerized films evaluated in this study suggest that this general class of materials is likely to exhibit excellent biocompatibility.

Animals↗
PubMed1991

Long-term follow-up of patients with recurrent malignant gliomas treated with adjuvant adoptive immunotherapy.

Between August 1986 and October 1987, the Denver Brain Tumor Research Group conducted a clinical trial using autologous human recombinant interleukin-2 (rIL-2)-activated lymphocytes to treat 20 patients with recurrent high-grade gliomas. The trial involved surgical resection and/or decompression followed by intracavitary implantation of lymphokine-activated killer (LAK) cells and autologous stimulated lymphocytes (ASL) along with rIL-2 in a plasma clot. One month later, stimulated lymphocytes and rIL-2 were infused through a Rickham reservoir attached to a catheter directed into the tumor bed. The LAK cells were rIL-2-activated peripheral blood lymphocytes cultured for 4 days; the ASL were lectin- and rIL-2-activated peripheral blood lymphocytes cultured for 10 days. Of the 20 patients treated, 11 were evaluated as a group (mean age, 44 years, range, 15-61 years; mean Karnofsky rating, 69, range, 50-100; mean Decadron dose at entry, 14 mg/d, range, 0-32). The average number of lymphocytes implanted was 7.6 x 10(9) (range, 1.9-27.5 x 10(9], together with 1 to 4 x 10(6) U of rIL-2. To date, 10 of the 11 patients died, all from recurrent tumor growth. The median overall survival time was 63 weeks (range, 36-201; mean, 86). The median survival time after immunotherapy was 18 weeks (range, 11-151; mean, 39). No significant difference in survival after immunotherapy was found between those patients who had received previous chemotherapy and those who had not. The use of steroids or prior chemotherapy did not influence the in vitro generation of ASL or LAK cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Developmental tasks: a key to reducing teenage pregnancy.

The developmental tasks of adolescence are discussed as a factor in some adolescents' risky sexual activity, which may lead to pregnancy. This theory is presented in the context of a case study. Nursing diagnoses, possible interventions, and nursing implications are examined in relation to assisting at-risk teens to meet their developmental needs. It is hoped that this article will stimulate further dialogue in the literature of developmental causes of teenage pregnancy, identification of those at risk, and appropriate nursing responses.

Adolescent↗
PubMed1990

A hydrophilic plasma polymerized film composite with potential application as an interface for biomaterials.

A hydrophilic polymer composite film (approx. 420 nm thick), with potential application as an interface for biomaterials has been prepared on nonorganic substrates, which include glass, silicon, and aluminum foil, using a glow discharge plasma polymerization technique. A thin film (110 nm thick) polymerized from hexane provided an adherent protective coating for the substrate material, and covalent bonding sites for the outer layer polymerized from N-vinyl-2-pyrrolidone. This outer layer provided the hydrophilic surface or interface. The two layers were copolymerized for a short period during transition between monomers to provide an intimate covalently bonded diffuse interphase. Preliminary in vitro and in vivo biocompatibility studies indicate that the hydrophilic film is non-cytotoxic, and does not increase the inflammatory response when compared with negative controls.

Animals↗
PubMed1990

Enterically transmitted non-A, non-B hepatitis associated with an outbreak in Dhaka: epidemiology and public health implications.

Investigation of an outbreak of hepatitis in Dhaka implicated enterically transmitted non-A, non-B (ET-NANB) hepatitis as the etiologic agent. This observation was made by exclusion in 17 of 19 patients, and confirmed serologically in one randomly selected patient by a fluorescent antibody blocking assay specific for ET-NANB hepatitis. These findings reinforce earlier suspicions that ET-NANB may be an important cause of acute hepatitis in Bangladesh. The epidemiology of ET-NANB hepatitis is discussed, and public health recommendations are made.

Bangladesh↗
PubMed1989

Interleukin-2-activated lymphocytes from brain tumor patients. A comparison of two preparations generated in vitro.

Two preparations of human recombinant interleukin-2 (rIL-2)-activated lymphocytes from patients harboring malignant brain tumors were characterized as autologous-stimulated lymphocytes (ASL) and lymphokine-activated killer (LAK) cells. ASL were generated from Ficoll-Paque-isolated, nonadherent, defibrinated peripheral blood lymphocytes (PBL) that were stimulated overnight with phytohemagglutinin (PHA) and cultured with rIL-2 (100 U/ml) for 10 days. LAK cells were produced by culturing all PBL in rIL-2 (500 U/ml) for 4 days. In 4-hour chromium release assays, LAK cells showed greater cytotoxicity than ASL against natural killer (NK)-sensitive and NK-resistant tumor cell lines; by 18 hours, the effectiveness of ASL equaled that of LAK cells. By electron microscopic study, PBL, LAK cells, and ASL showed differences. The helper/inducer to suppressor/cytotoxic ratio (T4+/T8+) of PBL, LAK cells, and ASL was 1.1:1, 1.0:1, and 0.4:1, respectively. ASL, when compared with PBL or LAK cells, have a significantly higher percentage of MO1+/DR+ and T8+/9.3+ subpopulations. ASL and LAK cells, used for the therapy of gliomas, are distinct.

Antibodies, Monoclonal↗
PubMed1989

Two related viroids cause grapevine yellow speckle disease independently.

We have confirmed that two closely related circular RNA molecules previously named grapevine yellow speckel viroid (GYSV) and grapevine viroid 1B (GV1B) are indeed viroids. Electron microscopy after spreading under non-denaturing conditions revealed that GYSV has a rod-like structure typical of viroids. Purified GYSV and GV1B replicated independently in inoculated grapevine seedlings and some of the infected plants developed yellow speckle symptoms indicating that both viroids can cause grapevine yellow speckle disease. Plus-sense RNA transcripts derived from a dimeric GYSV cDNA clone induced yellow speckle symptoms in a grapevine seedling confirming the role of GYSV in the yellow speckle disease. Two oligonucleotide probes were synthesized for the detection of the two related viroids. The probes which could detect each viroid individually were used to assess correlations between the occurrence of these viroids and the incidence of the disease.

Base Sequence↗
PubMed1989

Discrimination against AIDS victims.

Samples were taken from "Middletown" in 1985, 1986, and 1987 to assess tendencies to discriminate against AIDS victims and what factors were related to this tendency. A tendency to discriminate against AIDS victims has decreased significantly from 1985 to 1987, and those who are most likely to discriminate were members of the Christian Right and who have more of an individual than a community orientation.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Epidemiology of insulin dependent diabetes before age 20 in Wisconsin, with particular reference to seasonality.

Physicians in the State of Wisconsin were contacted by mail and asked to report all cases of diabetes in patients under 20 yr diagnosed between 1 July 1982 and 30 June 1984 in order to study factors associated with seasonality in insulin-dependent diabetes mellitus (IDDM). Wisconsin's population is fairly homogeneous and is primarily middle socioeconomic class, small-town or rural, and of northern European Caucasian descent. The incidence of IDDM in winter was higher than in summer during the first year of the study, similarly to results of other studies. However, there was no significant winter peak in diagnosis during the second year. When monthly incidence rates from both years were combined, the increased evidence of IDDM in winter vs. summer was evident in males, but not in females. There appeared to be a spike in the number of new cases of IDDM in the first year of the study which was more evident in males. Such a spike is consistent with spikes in the incidence of IDDM occurring about the same time in Europe and in North America. The percentage of patients with antibody titres to Coxsackie virus and mycoplasma pneumoniae diagnosed during the first winter's peak were equal to those in nondiabetic controls. The distributions of HLA DR types of patients diagnosed in winter were no different from diabetics diagnosed in other seasons. The distribution of HLA DR types (5% DR2, 55% DR3, 82% DR4 and 38% DR3DR4) were similar to those of other groups of Caucasian subjects with IDDM. Also similarly to other studies of IDDM, 14% of the patients had thyroid microsomal antibody titers. The results of this study support the previously-advanced idea that winter might precipitate overt carbohydrate intolerance in individuals in whom insulin cell destruction is already well established (Diabetes, 36, 265-268, 1987). If this is true, studies of seasonality in IDDM might not be informative about the causation of IDDM.

Adolescent↗
PubMed1988

The diagnosis of temporomandibular joint disease: two-compartment arthrography and MR.

The reliability and accuracy of two-compartment temporomandibular joint (TMJ) arthrography was compared with MR imaging on the basis of an analysis of surgical findings obtained from joints that had been studied preoperatively with arthrography or MR or, in some cases, both procedures. Seven hundred forty-three consecutive TMJ arthrograms were successfully obtained in a total of 443 patients by using a single 27-gauge needle and a two-compartment technique in each joint. There was a 100% correlation with surgical findings in 218 radiologically abnormal joints operated on within 90 days of arthrography with respect to the presence or degree of meniscus displacement and normal or abnormal disk morphology and function. In 604 patients 1052 TMJs were studied with high-field-strength surface-coil MR. Surgical findings were available for correlation in 170 of the joints studied. Forty-three joints were studied with both two-compartment arthrography and MR. Eight operated joints had been imaged successfully with both two-compartment arthrography and MR. Both methods of evaluation provided highly reliable and accurate information regarding meniscus position and shape. Arthrography was superior to MR in detecting capsular adhesions and the presence or absence of perforation of the disk or meniscus attachments. Simple meniscectomy (with or without insertion of a temporary Silastic TMJ implant) was the most frequently performed surgical procedure in the series, followed by meniscus repositioning procedures. Joint effusions, failed TMJ implants, and avascular necrosis were demonstrated best with MR. Soft-tissue lesions, including intrinsic degeneration of the meniscus, anomalous muscle development, muscle atrophy, tendinitis, and injuries such as contusions and hematomas, were demonstrated only with MR. Partial-flip-angle GRASS (gradient-recalled acquisition in the steady state) techniques permit both fast scanning and study of functional joint dynamic. Joint fluid may appear as high signal intensity on GRASS images because of T2*-weighting. We recommend MR as the procedure of choice for diagnosis of uncomplicated internal derangements of the TMJ. Two-compartment arthrography with videofluoroscopy is an important ancillary procedure that should be performed whenever capsular adhesions or perforations are suspected and not demonstrated with MR and whenever MR is inconclusive.

Arthrography↗
PubMed1981

Carbon-13 nuclear magnetic resonance spectroscopic study of teichuronic acid from Micrococcus luteus cell walls. Comparison of the polysaccharide isolated from cells with that synthesized in vitro.

Teichuronic acid isolated from the cell walls of Micrococcus luteus has been examined by natural-abundance (13)C NMR spectroscopy. Proton-decoupled and proton-coupled spectra were obtained for native teichuronic acid and also after the teichuronic acid had been oxidized with periodate and reduced with borohydride. The spectra are consistent with the structure [ManNAcUAp-( beta -1,6)-G1cp-( alpha -1,4)]n. Teichuronic acid synthesized in vitro from suitable substrates by the particulate enzyme fraction obtained from M. luteus yielded a (13)C NMR spectrum which is indistinguishable from that of the native teichuronic acid, indicating a structural identity of the teichuronic acid synthesized in vitro with that isolated from cell walls.

Cell Wall↗
PubMed1980

Anterior cervical discectomy without fusion: long-term results.

The long-term follow-up of patients operated by one surgeon by simple anterior discectomy without fusion have been presented. The results are much better in patients with soft extruded discs than with painful discs or degenerative discs with varying degrees of radiculopathy or myelopathy. The same statement can be made for the posterior approach. The anterior approach appears to be superior for soft central extruded discs compressing the spinal cord. There appears to be a greater incidence of another disc at an adjacent level with the anterior approach than when the operation is done posteriorly. The anterior operation is an easier surgical procedure than the posterior operation in the average surgeon's hands; otherwise, it would not be as popular as it is. Interbody fusion has no long-term advantages over simple discectomy. Complications of the anterior approach, particularly with fusion, appear greater than the limited posterior approach. Rather than continue the controversy over the anterior vs. the posterior approach, it is recommended that each surgical case be evaluated to determine the preferred approach. With the passage of time, I have preferred to operate the C4, 5, and 6 ruptured discs anteriorly, as well as all central discs or hard central cervical spondylotic bars. This seems preferable to the extensive laminectomy recommended by many for spondylotic myelopathy. However, the anterior approach has been limited to two spaces rather than multiple spaces. On the rare occasions when an extensive decompression of the cervical canal is indicated, the posterior approach has been chosen. In addition, the C7 or rare T1 soft ruptured disc have been done posteriorly. When there is a doubt about the diagnosis, e.g., when a tumor is suspected or a multiple root defect associated with atypical findings on myelography, the posterior approach is preferred.

Chronic Disease↗
PubMed1980

Reverse discrimination and aggressive behavior.

Aggression of each of 32 white male and female university students toward an opponent who had just defeated him in a competition was assessed in a 2 X 2 experiment design in which the winning opponent was either a black or a white and the loss was for one or two reasons: because the opponent 1) was economically deprived or 2) had superior ability. It was assumed that those Ss who had lost to a black opponent because this person was economically deprived experienced reverse discrimination based on race. Results indicated that white Ss were more aggressive toward a black when the loss was based on economic deprivation (reverse discrimination) than towards a white when the loss was due to economic deprivation (an arbitrary loss but not based on race), whereas white Ss were less aggressive towards a black opponent than towards a white opponent when the Ss lost because of the other's superior ability. The practical and theoretical implications of these results are discussed.

Aggression↗