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Biomedical subjects

S Johnson

Publications and source records attributed to S Johnson.

At least 289 records · Page 16Linked to original sources
PubMed1995

Depression and anxiety disorder among older male inmates at a federal correctional facility.

The conditions of incarceration and the sociodemographic and health characteristics of 95 older male inmates of a federal correctional facility were studied to determine the relationship of such variables to rates of psychiatric disorder among older male inmates. A total of 51 inmates (53.7 percent) met one-month criteria for psychiatric disorder, a much higher rate than among a community sample of men in the same geographic area. Compared with inmates without such disorders, inmates with disorders were likely to be younger, to have a history of psychiatric disorder and substance abuse, to have poorer physical health, to have impaired social support, and to be serving a determinate sentence with no possibility of parole. Few were receiving treatment while incarcerated.

Age Factors↗
PubMed1995

Comparison of hard- and soft-copy digital chest images with different matrix sizes for managing coronary care unit patients.

OBJECTIVE: This study was to determine whether different digital display formats for portable chest radiographs of coronary care unit patients would provide comparable information for clinical care. In particular, we tried to ascertain whether 1024 x 1024 pixel (1K) images on a picture archiving and communication system (PACS) workstation would be comparable to 1760 x 2140 pixel (2K) images on workstations or to digital films. If comparability could be proved, we hypothesized that 1K workstations could considerably lower equipment and film costs and facilitate image transmission from point to point. MATERIALS AND METHODS: Four chest radiologists read a panel of chest studies assembled from 98 coronary care unit patients, comparing 1K and 2K soft-copy images with digital hard copies. For all three image types for the 98 patients, the readers evaluated nine image parameters that the cardiologists deemed essential for clinical decision making. Two other chest radiologists reviewed each patient's three image types, historical chest images, current and prior radiologic reports, and medical record to determine the consensus, or "truth findings." RESULTS: With one exception (small pleural effusions), the receiver operating characteristic analysis showed no significant differences in the clinical information derived from the three image types. CONCLUSION: For clinical management in a coronary care unit, comparable information can be obtained from digital radiologic chest studies using a 1K x 1K soft-copy format, a 2K x 2K soft-copy format, or a hard copy (film). Substantial savings in cost and time are therefore possible by using soft-copy images and lower resolution (1K x 1K) workstations and, when necessary, by transmitting images on regular telephone lines.

Coronary Care Units↗
PubMed1995

Paclitaxel by 24- or 1-hour infusion n combination with carboplatin in advanced non-small cell lung cancer: the Fox Chase Cancer Center experience.

A phase II trial of combination paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) and carboplatin included 54 chemotherapy-naive patients with advanced non-small cell lung cancer. Eligibility mandated Eastern Cooperative Oncology Group performance status of 0 or 1 and adequate hematologic, renal, and hepatic function. Paclitaxel 135 mg/m2 over 24 hours preceded carboplatin dosed to an area under the concentration-time curve of 7.5. Six planned courses were given every 3 weeks. Granulocyte colony-stimulating factor was introduced during the second and subsequent cycles, and paclitaxel increased 40 mg/m2/cycle (maximum, 215 mg/m2) in patients with absolute neutrophil and platelet nadirs exceeding 500/microL and 50,000/microL, respectively. Grade 3 or 4 neutropenia, observed in 54% of patients during cycle 1, declined to 35% during cycle 2 and to 22% or less during cycles 3 through 6. Neuropathy, myalgias/arthralgias, and thrombocytopenia were mild but cumulative. In 53 evaluable patients, the objective response rate was 62%, with 9% complete remissions and a median response duration of 6 months (range, 1 to 19+ months). At median potential follow-up of 16 months, 9% of patients remain progression free (52+ to 80+ weeks). Median survival is 12.5 months; 1-year survival is 54%. Paclitaxel/carboplatin is highly active in advanced non-small cell lung cancer; granulocyte colony-stimulating factor abrogates neutropenia as the dose-limiting toxicity, but has no effect on the cumulative incidence of thrombocytopenia or treatment delays. One-hour paclitaxel infusion is minimally myelosuppressive, logistically easier, and less costly. A follow-up study combined paclitaxel (175 mg/m2) over 1 hour followed by carboplatin (area under the concentration-time curve, 7.5). In the absence of grade 4 myelosuppression, paclitaxel was increased 35 mg/m2/cycle (maximum, 280 mg/m2). Granulocyte colony-stimulating factor was implemented only after neutropenic fever or grade 4 neutropenia. Of 17 patients entered, 13 are evaluable for toxicity and seven for response. Four patients have sustained a partial response, two a minor response, and one stable disease. The incidence of grade 3 or 4 neutropenia, thrombocytopenia, and anemia in cycle 1 was 38%, 16%, and 0%, respectively, and 72%, 28%, and 28%, respectively, during cycle 2. Major nonhematologic toxicities include myalgias and arthralgias (54%) and fatigue and neuropathy (78%), the latter cumulative and progressive over successive cycles. Preliminary data suggest comparable activity for the 1- and 24 hour paclitaxel infusions in combination with carboplatin. The more severe neuropathy of the 1-hour paclitaxel/carboplatin combination may be related to the paclitaxel dosing schema (175 mg/m2 to as high as 280 mg/m2).(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1995

Comparison of 1.5 Tesla and 0.35 Tesla field strength magnetic resonance imaging scans in the morphometric evaluation of the lumbar intervertebral foramina.

OBJECTIVE: To compare magnetic resonance imaging (MRI) scans obtained from 1.5 Tesla (T) MRI units with scans obtained from 0.35T MRI units in the morphometric evaluation of the lumbar intervertebral foramina (IVF). DESIGN: Three dimensions of lumbar IVFs were measured on a cadaveric lumbar spine by using Vernier calipers. The spine was embedded in gelatin to simulate soft tissue and scanned twice in a 1.5T MRI unit (3-mm and 5-mm slice thicknesses) and once in a 0.35T MRI unit (5-mm slice thickness). Measurements from the scans were made independently by three observers. The results obtained from the two units were compared to the actual IVF size (as measured by calipers) and to one another. RESULTS: The greatest superior-to-inferior distance had the strongest statistically significant correlation to the actual cadaver measurements for both the 0.35T and 1.5T imaging units [r = 0.986 (0.35T); r = 0.985 (1.5T at 3 mm) and r = 0.981 (1.5T at 5 mm); p < .0001 in all cases]. Mean differences and standard errors were minimal between measurements made from MRI scans of both 1.5T and 0.35T units and measurements made directly from the cadaveric spine. CONCLUSION: Both imaging units produced images that accurately depicted the actual size of the IVF. The MRI units of 0.35T field strength produced images of high morphometric accuracy. In addition, the potential for side effects and the operating costs are less with 0.35T units. Therefore, 0.35T MRI units may be a prudent choice as a clinical and research imaging tool in the evaluation of the lumbar IVF.

Humans↗
PubMed1995

The effect of epidural anesthesia on the length of labor.

BACKGROUND: Epidural anesthesia, although effective, has been associated with changing the course of labor. Previous studies have been criticized for not pinpointing the factors determining the use of epidural anesthesia. The purpose of this study was to determine the effect of epidural anesthesia use on the course of labor. METHODS: A retrospective chart review of 224 women who gave birth from July 1, 1993, to June 30, 1994, was completed in a small-town family practice. The time frame included 6 months before and after the initiation of Tenncare, a state-funded health insurance plan designed to serve the uninsured and those previously served by Medicaid in Tennessee. RESULTS: The rate of epidural anesthesia use in this study population fell sharply after January 1, 1994, the start date for Tenncare. Epidural anesthesia by women in this study was found to increase the average length of the second stage of labor by 38 minutes for primiparas and 23 minutes for multiparas. CONCLUSIONS: The average length of the second stage of labor is significantly longer for women who receive epidural anesthesia. The rate of epidural anesthesia use in this study population was strongly influenced by a change in health-care financing.

Adult↗
PubMed1994

YAC contig organization and CpG island analysis in Xq28.

One hundred nineteen YACs were assembled into 6 contigs spanning about 7.1 Mb of Xq28. The contigs were formatted with 65 STSs and 136 hybridization probes and were extensive enough to be aligned and oriented by published genetic linkage and somatic cell hybrid panel data. Selected YACs from the entire region were mapped with five rare-cutter restriction enzymes to infer the position of putative CpG islands indicative of gene locations; 48 such sites were identified by the near-coincidence of at least three rare-cutter sites. The analysis defined three subregions of Xq28: 4 Mb of moderate GC and CpG island content from the Xq27 border through the GABRA locus; 1.5 to 2 Mb, extending to the G6PD gene, that is variably and poorly cloned, but contains a high concentration of CpG islands and GC; and about 1.5 Mb between G6PD and the telomere, which is generally low in CpG and GC levels, including a subtelomeric DNA region that shows extensive homology to Yq DNA.

Chromosome Mapping↗
PubMed1994

Factor analysis of multiple measures of body image disturbance: are we all measuring the same construct?

Two studies were conducted to determine the overlap among multiple measures of subjective body image disturbance. Study 1 was conducted on 219 adolescent females (ages 14-18 years) who completed seven widely used indices of self-reported body image disturbance. Study 2 involved 162 college females (ages 17-35 years) and six measures of disturbance, five of which were identical with those instruments used in Study 1. Factor analyses indicated the existence of two factors in the adolescent sample, however, one factor was quite strong and accounted for most of the variance. Analyses on the adult subjects revealed the existence of a single body image factor. It was concluded that the measures under investigation largely reflect an underlying single factor of body image, despite their common usage in the literature as indicators of multiple aspects of body image disturbance.

Adolescent↗
PubMed1994

Entry of coronavirus into primate CNS following peripheral infection.

A previous report demonstrated that intracerebrally inoculated coronavirus produced CNS disease in two species of primates (Murray RS, Cai G-Y, Hoel K, et al., Virol 1992; 188: 274-84). We were therefore interested in testing the potential of coronaviruses to infect primate CNS tissue following peripheral inoculation. Four Owl monkeys (Aotus trivirgatus) were inoculated intranasally and ocularly and four were inoculated intravenously with coronavirus JHM OMp1 (Murray RS, Cai G-Y, Hoel K, et al., Virol 1992; 188: 274-84). Two intranasally and two intravenously inoculated animals received a second intravenous inoculum at 153 days post-infection. The animals were sacrificed 16, 35, 194, and 215 days post-infection. Tissue sections from brain and spinal cord were screened for viral products by in sity hybridization and immunostaining. Virus RNA and/or antigen was detected in the brains of all animals and the distribution corresponded to areas of inflammation and edema. Viral products were predominantly found in blood vessels and perivascular regions, suggesting hematogenous spread with entry into the central nervous system through endothelium.

Administration, Intranasal↗
PubMed1994

CO2 crop growth enhancement and toxicity in wheat and rice.

The effects of elevated CO2 on plant growth are reviewed and the implications for crop yields in regenerative systems are discussed. There is considerable theoretical and experimental evidence indicating that the beneficial effects of CO2 are saturated at about 0.12% CO2 in air. However, CO2 can easily rise above 1% of the total gas in a closed system, and we have thus studied continuous exposure to CO2 levels as high as 2%. Elevating CO2 from 340 to 1200 micromoles mol-1 can increase the seed yield of wheat and rice by 30 to 40%; unfortunately, further CO2 elevation to 2500 micromoles mol-1 (0.25%) has consistently reduced yield by 25% compared to plants grown at 1200 micromoles mol-1; fortunately, there was only an additional 10% decrease in yield as the CO2 level was further elevated to 2% (20,000 micromoles mol-1). Yield increases in both rice and wheat were primarily the result of increased number of heads per m2, with minor effects on seed number per head and seed size. Yield increases were greatest in the highest photosynthetic photon flux. We used photosynthetic gas exchange to analyze CO2 effects on radiation interception, canopy quantum yield, and canopy carbon use efficiency. We were surprised to find that radiation interception during early growth was not improved by elevated CO2. As expected, CO2 increased quantum yield, but there was also a small increase in carbon use efficiency. Super-optimal CO2 levels did not reduce vegetative growth, but decreased seed set and thus yield. The reduced seed set is not visually apparent until final yield is measured. The physiological mechanism underlying CO2 toxicity is not yet known, but elevated CO2 levels (0.1 to 1% CO2) increase ethylene synthesis in some plants and ethylene is a potent inhibitor of seed set in wheat.

Biomass↗
PubMed1994

Immunohistochemical analysis of cutaneous malignant melanoma: comparison of S-100 protein, HMB-45 monoclonal antibody and NKI/C3 monoclonal antibody.

Immunohistochemical analysis was carried out on 144 formalin fixed paraffin embedded cutaneous melanomas to ascertain the value of 3 different immune markers. The sensitivity and staining patterns regarding intensity and distribution, as well as correlation to pigment content, cell type, surface ulceration and host response was noted. The stains used were monoclonal HMB-45 (Dako product No M634), NKI/C3 antibodies (Biogenex product No MU077) and polyclonal rabbit anti S-100A protein (Dako product No L1845). Of the lesions tested, 63 were malignant melanoma with an adjacent component of superficial spreading type, 61 were malignant melanoma with no adjacent component, 2 were malignant melanoma with adjacent lentigo maligna, 8 were in situ with 7 superficial spreading melanoma and one lentigo maligna (HMF) and 10 were metastatic melanoma. All 144 lesions stained for S-100 (100% sensitivity). One hundred and thirty-seven stained for NKI/C3 (95%); 132 stained for HMB-45 (92% sensitivity). S-100 was the most sensitive marker and stained tumor cells diffusely. With HMB-45 and NKI/C3, though marginally less sensitive, staining was stronger and patchy. In addition, NKI/C3 showed a tendency for peripheral (membrane) staining. HMB-45 staining was directly proportional to the pigment content, with stronger staining of radial growth phase melanoma and negative staining of those lesions where pigment content was minimal or absent. Also, with HMB-45 a decrease in staining intensity with depth or vertical growth phase was observed. There was no relationship to cell type with HMB-45 but with NKI/C3, 5 out of the 7 that failed to stain showed spindle cell differentiation.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗
PubMed1994

Clinical courses of seven survivors of Clostridium septicum infection and their immunologic responses to alpha toxin.

Clostridium septicum bacteremia typically portends a fulminant disease associated with high mortality. We describe the clinical courses of seven survivors of C. septicum infection and their antibody responses to the alpha toxin produced by C. septicum. Three patients had clinical syndromes ranging from uncomplicated bacteremia to early typhlitis, and three patients had syndromes ranging from abscess to myonecrosis and septic shock. In addition, an AIDS patient who developed septic shock and who had extensive gas in the retroperitoneal musculature did not undergo surgery but survived after receiving antimicrobial therapy and intensive supportive care. Both immunocompetent patients with myonecrosis had detectable IgG to alpha toxin by immunoblot analysis. IgG to alpha toxin was not detected in the four immunocompetent patients who had C. septicum bacteremia but who did not have myonecrosis or in the AIDS patient with myonecrosis. Therefore, humoral responses to alpha toxin during C. septicum infection may be related to the host's clinical syndrome and immune status.

Adult↗
PubMed1994

Trends in firearm suicide among older American males: 1979-1988.

Elderly men are more likely to commit suicide than any other age group in the United States. Moreover, their rate of suicide steadily increased between 1979 and 1988. National Center for Health Statistics (NCHS) Compressed Mortality data were used to perform an age-specific analysis of linear trends. Males 65 and over were the most likely to use firearms followed by those 55-64. In 1988, nearly 8 out of 10 suicides by males 65 and over were committed with a firearm. Firearm-related suicide rates were much lower for blacks than whites 65 and over; however, suicides among blacks were more likely to involve firearms than among whites in this age group. The authors call for a broad public policy effort directed at reducing the availability of firearms.

Adolescent↗