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Biomedical subjects

J C Johnson

Publications and source records attributed to J C Johnson.

At least 19 recordsLinked to original sources
PubMed1992

Prognostic significance of polymerase chain reaction detected human papillomavirus of tumors and lymph nodes in surgically treated stage IB cervical cancer.

This study describes the prognostic role of polymerase chain reaction detected human papillomavirus (HPV) in Stage IB cervical cancer patients treated with radical hysterectomy and pelvic and paraaortic node dissection. All tumors were confined to the cervix and all margins and nodes were disease free. Twenty-one patients were analyzed: 6 patients recurred within 20 months of initial therapy, while 15 had no evidence of disease with a minimum follow-up of 36 months. Polymerase chain reaction (PCR) was performed on paraffin-block tissue of the hysterectomy specimen cervical tumor and lymph nodes. Oligonucleotide probes for HPV types 6, 11, 16, 18, 31, 33, and 35 were used with consensus primers for uncharacterized HPV types created from an L1 constant region. Control tissues were run with each tumor sample to assure against contamination. HPV type confirmation was performed using diagnostic restriction sites. HPV was detected in all cervical tumors. Recurring tumors were infected with multiple types of HPV in all 6 tumors versus only 5 of 15 nonrecurring tumors being multiply infected (P = 0.023). No tumor had HPV 6 or 11, and the incidence of HPV 16, 31, 33, and 35 was not significantly different for recurrent versus nonrecurrent groups. HPV 18 was found in 5 of 6 recurring cancers versus 1 of 15 nonrecurring tumors (P = 0.0029). PCR typing of the histologically negative nodes that had been obtained at radical hysterectomy was done in all 6 recurring patients and in 6 nonrecurring patients. The recurrent patients had a significantly higher incidence of lymph nodes positive for HPV DNA (71%) than the nonrecurring patients (35%) (P = 0.0047). These observations suggest that HPV 18 cervical cancer patients, those with infections of multiple types, and those with HPV DNA in histologically negative lymph nodes may be at increased risk for recurrence.

Adult↗
PubMed1992

High frequency of latent and clinical human papillomavirus cervical infections in immunocompromised human immunodeficiency virus-infected women.

In 32 human immunodeficiency virus (HIV)-infected women, routine gynecologic examination was performed with colposcopy and Papanicolaou smear; cervical swabs were collected for human papillomavirus (HPV) DNA screening and typing; and immune status was assessed by CD4 T-cell count. Dot blot analysis was specifically chosen for HPV DNA screening to detect only relatively substantial HPV DNA infections. Polymerase chain reaction analysis was used for precise DNA typing of dot blot-positive samples. The HPV data were assessed for immune status; a subject with a CD4 T-cell count below 200/microL was considered functionally immunosuppressed. The frequency of dot blot positivity was fivefold higher among immunocompromised (nine of ten) than relatively immunocompetent (four of 22) HIV-infected women. Moreover, four immunosuppressed women, compared with no immunocompetent subjects, had evidence of HPV DNA without signs of HPV-associated lesions by cytology or histology (ie, latent HPV infection). Furthermore, four of nine of the immunocompromised, compared with four of 21 immunocompetent, subjects had cervical intraepithelial neoplasia. These frequencies are high compared with those reported in the general population. Finally, HPV 18 was detected in five of the ten women with CD4 T-cell counts below 200/microL and in only one of the 22 with CD4 T-cell counts above that level. These results suggest that the normal immune system suppresses latent and clinical HPV cervical infections and that the efficiency of suppression may be HPV type-specific. Furthermore, impaired immune status, as reflected by CD4 T-cell count, is an important factor increasing the severity of HPV-induced cervical infections in this population.

Adult↗
PubMed1992

Prospective versus retrospective methods of identifying patients with delirium.

OBJECTIVE: To determine if DSM-III criteria or clinical or discharge diagnoses, reviewed retrospectively, are as accurate an indicator of the presence of delirium as prospective evaluation by a psychiatrist. DESIGN: Selection of delirious patients prospectively by a psychiatrist, followed by retrospective record review of the same patients. SETTING: A referral-based university hospital. PATIENTS: From a sample of 235 consecutive medical patients over age 70, 47 delirious patients were identified prospectively by a research psychiatrist using DSM-III criteria. The medical record of these delirious patients was reviewed after discharge for evidence of delirium. RESULTS: Four patients were assigned ICD-9 codes suggestive of delirium (sensitivity 0.09). Review of physicians' diagnoses correctly identified 8 of 47 (sensitivity 0.17) patients as being delirious or acutely confused. The specific diagnostic criteria necessary to meet a DSM-III diagnosis of delirium could be ascertained from 10 of 47 records (sensitivity 0.21). CONCLUSION: The retrospective medical record review is very imprecise in establishing the diagnosis of delirium. As research in this field moves from descriptive epidemiology to studies of pathogenesis and treatment, prospective designs will be needed.

Abstracting and Indexing↗
PubMed1992

Functional status outcomes of a nursing intervention in hospitalized elderly.

This paper examines the effectiveness of a nursing intervention for elderly hospitalized patients (N = 235) as measured by functional outcomes. A nursing intervention targeted at factors which influence acute confusion or delirium employed strategies to educate nursing staff, mobilize patients, monitor medication and make environmental and sensory modifications. Subjects who received the intervention were more likely to improve in functional status from admission to discharge than subjects who did not receive the intervention.

Activities of Daily Living↗
PubMed1992

Effect of sleep deprivation on brain metabolism of depressed patients.

OBJECTIVE: Sleep deprivation is a rapid, nonpharmacologic antidepressant intervention that is effective for a subset of depressed patients. The objective of this study was to identify which brain structures' activity differentiates responders from nonresponders and to study how metabolism in these brain regions changes with mood. METHOD: Regional cerebral glucose metabolism was assessed by positron emission tomography (PET) with [18F]deoxyglucose (FDG) before and after total sleep deprivation in 15 unmedicated awake patients with unipolar major depression and 15 normal control subjects, who did the continuous performance test during FDG uptake. RESULTS: After sleep deprivation, four patients showed a 40% or more improvement on the Hamilton Rating Scale for Depression. Before sleep deprivation the depressed responders had a significantly higher cingulate cortex metabolic rate than the depressed nonresponders, and this normalized after sleep deprivation. The normal control subjects and nonresponding depressed patients showed no change in cingulate metabolic rate after sleep deprivation. CONCLUSIONS: Overactivation of the limbic system as assessed by PET scans may characterize a subset of depressed patients. Normalization of activity with sleep deprivation is associated with a decrease in depression.

Adult↗
PubMed1992

Calculation of radiation dose at a bone-to-marrow interface using Monte Carlo modeling techniques (EGS4)

Radiation dose rate profiles at a bone-to-marrow interface were calculated by simulating a uniform radiation source at the center of the endosteal layer in a long bone. Isotopes (153Sm, 186Re, and 166Ho) were assumed to assimilate as surface agents and the dose profiles were calculated on a microscopic scale using the Electron-Gamma Shower (EGS4) computer program. We validated our computational model against published dose factors (delta) for uniform volume distributed sources replicating them to an accuracy of better than 95%. The calculated dose distributions illustrate the relative contribution of atomic electrons, beta, and photon fractions. The backscatter contribution to marrow dose increased from 3% to 4% at the source to 6% to 8% at a marrow depth of 100 microns. Backscattered dose fraction was not significantly different among the three isotopes. The dose contribution from the three isotopes was remarkably similar at ranges between 25 and 125 microns.

Bone Marrow↗
PubMed1991

PET in generalized anxiety disorder.

Positron emission tomography (PET) measurements of cerebral glucose use were made in 18 patients with generalized anxiety disorder (GAD) during a passive viewing task off medication, and an active vigilance viewing task before and after medication or placebo treatment. In the passive viewing task, patients with GAD were compared with 15 normal controls. A significant difference in pattern of absolute brain metabolism was found. Patients showed lower absolute metabolic rates in basal ganglia and white matter. Relative metabolism was increased in the left inferior area 17 in the occipital lobe, right posterior temporal lobe, and the right precentral frontal gyrus. Significant left-right asymmetry of the parahippocampal gyri was not found in patients with GAD. An active vigilance task resulted in activation of relative basal ganglia metabolism in patients. Benzodiazepine therapy resulted in decreases in absolute metabolic rates for cortical surface, limbic system, and basal ganglia and was not associated with normalization of patterns of glucose metabolism. Change in anxiety scores was significantly correlated with change in limbic system and basal ganglia for the placebo group. The normal-anxious difference in the basal ganglia and the change seen in this region after benzodiazepine treatment are suggestive of a role in anxiety for this structure.

Adult↗
PubMed1991

Amantadine-related adverse reactions among African-American elderly nursing home residents.

To identify factors associated with the development of adverse reactions to amantadine prophylaxis for influenza in a predominantly African-American nursing home population, we retrospectively reviewed the records of 100 residents who did and 45 who did not receive amantadine. During the 4 weeks of amantadine treatment, three independent observers rated all new symptoms as either related or unrelated to amantadine. Two types of comparison were made. Among patients receiving amantadine, those who did or did not develop new symptoms believed to be related to amantadine were compared by age, underlying diagnoses, type and number of medications, and renal function. Similar comparisons were made between patients who did and those who did not receive amantadine. The 100 residents who received amantadine prophylaxis had significantly more nonspecific symptoms than the 45 who did not receive amantadine. Otherwise, the two groups were comparable with regard to age, renal function, number of diagnoses, and medications. Of the 100 residents given amantadine, 16% were judged to experience amantadine-related adverse reactions. Those developing amantadine-related symptoms were significantly more likely to have nonspecific symptoms and to use psychotropic medications.

Aged↗
PubMed1979

Aberrant jugular bulb presenting as a middle ear mass.

Case reports of 3 patients seen with a bluish mass behind the tympanic membrane are presented. The initial diagnosis was probable glomus tumor. In 1 patient, middle ear exploration confirmed the presence of a high-lying jugular bulb. In the other 2, venography demonstrated that the jugular bulb projected superiorly into the middle ear cavity. In all 3, polytomography demonstrated a dehiscence of the bony septum which normally separates the jugular bulb from the hypotympanum. When a bony dehiscence is seen in the absence of destructive changes, a diagnosis of aberrant jugular bulb is strongly suggested.

Adult↗
PubMed1978

Normal pressure hydrocephalus, parkinsonism, and primary empty sella--coincidence or cause-effect?

The triad of normal-pressure hydrocephalus, parkinsonism, and primary empty sella appeared in a 70-year-old woman. There was dramatic resolution of the extrapyramidal signs and symptoms on treatment with levodopa-carbidopa and ventriculojugular shunt. The syndrome may be the result of several mechanisms, but an alteration of cerebrospinal fluid (CSF) pressure dynamics may be the sole etiology for this triad.

Aged↗
PubMed1978

Comparison of analysis techniques for electromyographic data.

Electromyography has been effectively employed to estimate the stress encountered by muscles in performing a variety of functions in the static environment. Such analysis provides the basis for modification of a man-machine system in order to optimize the performances of individual tasks by reducing muscle stress. Myriad analysis methods have been proposed and employed to convert raw electromyographic data into numerical indices of stress and, more specifically, muscle work. However, the type of analysis technique applied to the data can significantly affect the outcome of the experiment. In this study, four methods of analysis are employed to simultaneously process electromyographic data from the flexor muscles of the forearm. The methods of analysis include: 1) integrated EMG (three separate time constants), 2) root mean square voltage, 3) peak height discrimination (three level), and 4) turns counting (two methods). Mechanical stress input as applied to the arm of the subjects includes static load and vibration. The results of the study indicate the comparative sensitivity of each of the techniques to changes in EMG resulting from changes in static and dynamic load on the muscle.

Electromyography↗