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Biomedical subjects

G L Hansen

Publications and source records attributed to G L Hansen.

16 recordsLinked to original sources
PubMed1997

Wound status evaluation using color image processing.

An accurate diagnosis of burns and pressure ulcers in the early stages can be made by computerized image processing. This study describes a critical assessment of potential methodologies for noninvasive wound evaluation using a color imaging system. We also developed a method for quantifying histological readings and applied these techniques to a porcine animal model of wound formation. Differences in calibrated hue between injured and noninjured skin provided a repeatable differentiation of wound severity for situations when the time of injury was known. This color analysis allowed statistically significant differentiation of mild, moderate, and severe injuries within 30 minutes after the application of the injury. It was more difficult to distinguish wound severity one to four days later, however the correlation re-emerged when the wounds were five to seven days old. This technique could be adapted for assessing and tracking wound severity in humans in a clinical setting.

Algorithms↗
PubMed1996

Relationship between dietary iron intake, corrected for diet reporting error, and serum ferritin in Danish women aged 35-65 years.

Several studies have failed to demonstrate an association between Fe status and intake of dietary Fe. However, in the long term, it seems logical to presume that body Fe reserves are, fundamentally, dependent on the intake of bioavailable dietary Fe. This discrepancy may depend on several factors: (1) interindividual variation in biological availability of dietary Fe (differences in intestinal absorption), (2) interactions between dietary Fe and absorption enhancers and inhibitors, (3) variations in physiological (menstruation, childbirth) or unphysiological (blood donation) Fe losses, (4) the failure to adjust dietary intake data for Fe supplements, (5) uncertain food composition data (discrepancies between calculated and chemically measured Fe content in the diet), and (6) diet reporting error (reported intake of dietary Fe may deviate considerably from the true intake). The present study examined associations between dietary intake of Fe (assessed by diet history interview) and Fe status (assessed by ferritin status) among 167 Danish women aged 35-65 years, who were not blood donors, by taking into account diet reporting error (assessed from p-amino benzoic acid-validated urinary N), physiological blood losses (menstruation, childbirth, abortions), and Fe supplementation. Our results indicate that the lack of a general association between Fe status and dietary Fe intake may, in part, be caused by selective diet reporting error.

Adult↗
PubMed1995

Temperature-modulated pressure ulcers: a porcine model.

OBJECTIVE: A reliable porcine model was developed to facilitate investigations of pressure ulcer formation, healing, and prevention. In the present study, it was specifically used to study the relationship between applied temperature, applied pressure, and time of application in the formation of cutaneous and deep tissue injuries. DESIGN: An apparatus and procedure were created to simultaneously apply 12 metal discs (each with a diameter of 51mm) on the dorsal aspect of the swine, all at an equal pressure of 100mmHg, for a 5-hour period, while servo-controlling disc temperatures at either 25, 35, 40, or 45 degrees C. RESULTS: The severity of the resultant tissue injuries correlated with an increase in applied temperature. No damage was observed in the superficial or deep tissues underlying the sites of the 25 degrees C pressure applicators. In general, only deep tissue damage resulted from the application of a 35 degrees C temperature, whereas the application of higher temperatures caused both cutaneous and subdermal damage (the extent of necrosis being greater at the 45 degrees C sites). There was a high degree of reproducibility of these results among a large population of sites per temperature (n = 64) and number of animals investigated (n = 16). Furthermore, subsequent healing (monitored up to 4 weeks) was uniform for the degree of induced damage. Insights into pressure ulcer formation were also sought via systematic examination of histological sides and postmortem visual assessment over the 4-week period. CONCLUSION: It was concluded that this animal model of temperature-modulated pressure ulcers has the potential for significant use in all major areas of this field, ie, wound formation, healing, and prevention.

Animals↗
PubMed1994

Expression of reverse transcriptase from feline immunodeficiency virus in Escherichia coli.

Reverse transcriptase from feline immunodeficiency virus (FIV) has been cloned and expressed in Escherichia coli. We have purified this recombinant enzyme and shown that it is a 66-kDa protein that is indistinguishable from virion-derived FIV reverse transcriptase in sensitivity to the 5'-triphosphates of 3'-azido-3'-deoxythymidine and the four 2',3'-dideoxynucleosides. The availability of large quantities of the FIV reverse transcriptase will allow more detailed physical and pharmacological studies.

Amino Acid Sequence↗
PubMed1993

Effect of methylprednisolone on the cytokine response in patients undergoing lung surgery.

Tumour necrosis factor alpha (TNF alpha), interleukin-1 alpha (IL-1 alpha) and IL-6, when released in excess, have been suggested to be important host mediators of the immunoinflammatory response to injury and infections. Corticosteroids suppress this response in vitro. This study was undertaken to investigate if a single dose of methylprednisolone (MP) could modify the cytokine response in patients undergoing lung surgery. Twenty-one patients with lung cancer were allocated randomly to treatment with MP 30 mg/kg i.v. (MP group) or isotonic saline (control group). Patients were anaesthetized with a balanced anaesthesia combined with thoracic epidural anaesthesia. MP or saline was administered immediately before induction of anaesthesia. The cytokines in plasma were measured by ELISA, and blood samples were collected preoperatively, at the end of surgery, 4 h later, and 1 and 5 days postoperatively. All patients had detectable IL-6 in plasma. Compared to preoperative values, plasma IL-6 levels in the MP group increased from 114 pg/ml (12-350 pg/ml) (mean, range) to peak value 146 pg/ml (15-580 pg/ml) on the first postoperative day. In the control group, IL-6 levels increased from 99 pg/ml (17-350 pg/ml) preoperatively to 125 pg/ml (10-300 pg/ml) on the first postoperative day. The increases were not significant. TNF alpha was detectable in only two patients, one from each group. Low levels of IL-1 alpha were demonstrated in three patients in the MP group and in four patients in the control group.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Increase in lactoferrin and elastase alpha-1-proteinase inhibitor complexes but lack of complement activation and IL-6 response following thoracic surgery.

UNLABELLED: Polymorphonuclear neutrophil (PMN) stimulation and degranulation can be mediated by the cytokines and by complement activation. The aim of the present study was to measure TNF alpha, IL-1 alpha, IL-6 and C3d in relation to postoperative increase in lactoferrin and elastase alpha-1-proteinase inhibitor (E alpha-1-PI) levels. Eleven patients undergoing thoracic surgery took part in the study. Blood leucocytes, E alpha-1-PI, lactoferrin and C3d were measured preoperatively, at the end of surgery and postoperatively, at 4 h and on day 1, 2, 3 and 5. TNF alpha, IL-1 alpha and IL-6 were measured preoperatively, at the end of surgery and postoperatively, at 4 h, and on days 1 and 5. The leucocyte count, lactoferrin and E alpha-1-PI levels increased significantly postoperatively (P < 0.01). There was no significant change in C3d values. Plasma IL-6 levels were unchanged in the postoperative period. Plasma TNF alpha and IL-1 alpha were detectable at low levels in only two and four patients, respectively. CONCLUSION: The postoperative increase in blood levels of PMN lactoferrin and E alpha-1-PI complexes observed in the present study was not accompanied by complement activation, or increased blood levels of IL-6.

Aged↗
PubMed1991

Chimeric human immunodeficiency virus type 1/type 2 reverse transcriptases display reversed sensitivity to nonnucleoside analog inhibitors.

Human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT), an important therapeutic target in the treatment of AIDS, is effectively inhibited by a class of nonnucleoside analog compounds that includes nevirapine (BI-RG-587) and tetrahydroimidazo[4,5,1-jk]-[1,4]benzodiazepin-2(1H)-one and -thione. We show that both tyrosine residues at positions 181 and 188 flanking the putative catalytic site of HIV-1 RT are required for sensitivity of the enzyme to these compounds. HIV-2 RT, which does not have tyrosines at these positions, is resistant to these nonnucleoside analog inhibitors. Substitution of the HIV-2 RT amino acid residues at position 181 or 188 into HIV-1 RT results in an enzyme that is resistant to these compounds while retaining sensitivity to 3'-azido-2',3'-dideoxythymidine triphosphate. HIV-2 RT substituted with amino acids 176-190 from HIV-1 RT acquires sensitivity to these nonnucleoside analog inhibitors.

Affinity Labels↗
PubMed1991

[Blood pressure among school 14-15 year old children. Blood pressure determination in school children aged 14-15 years in the county of Vejle by school physicians].

A total of 3,790 school pupils aged 14 and 15 years attending the ninth form during the school session 1986/87 were submitted to blood pressure measurements employing a digital sphygmomanometer. Where boys were concerned an average blood pressure of 123.9/65.9 mmHg was found while, in girls, the average blood pressure was 117.6/70.9 mmHg. In cases with blood pressure readings over the 90% fractile, repeated measurements are recommended. The 90% fractile for boys was 139/80 mmHg and for and for girls 133/84 mmHg. In cases where repeated measurements show blood pressure readings over the 95% fractile, further investigation and advice about risk factors are recommended. The 95% fractile for boys was 144/84 mmHg and 138/88 mmHg for girls. The influence of pubertal development and body-weight on the blood pressure are reviewed. Screening in connection with health examination in the ninth form is recommended in order to identify adolescents at risk for development of hypertension.

Adolescent↗
PubMed1990

[Reoperation for angina pectoris].

During the 16-year period from 1974 to 1989, coronary bypass operations were carried out on 938 patients. During the same period, 48 patients (5.1%) were submitted to reoperation on account of recurrent angina pectoris. Patients with early recurrence had more frequently graft-occlusion than patients with late recurrence in whom the main cause was progression of the arteriosclerotic cardiac condition. The actual rethoractomy was carried out without serious complications. The perioperative frequency of complications and the mortality correspond to the frequencies at the first operation. Follow-up control of these patients was undertaken after an average of 34 months (8-100) after reoperation. The results after reoperation as regards freedom from symptoms are not quite as good as the results after the primary operation but approximately 2/3 of the patients will benefit from reoperation.

Adult↗
PubMed1982

Androgyny, sex-role orientation, and homosexism.

In a study of the relationship between homosexism and both psychological androgyny and normative sex-role orientation, questionnaires were administered in 87 males and 119 female college students. Results indicate that males were less androgynous, more traditional in sex-role orientation and more homosexist than females. Homosexism was significantly related to sex-role orientation among males and to both androgyny and sex-role orientation among females. Homosexism appeared to contribute to maintaining traditional sexual differentiation among both males and females. This occurred more on the normative than on the psychological level.

Adult↗