Biomedical subjects

J Locher

Publications and source records attributed to J Locher.

At least 19 recordsLinked to original sources

PubMed1996

Education of staff and students in health care settings: integrating practice and research.

A cooperative program between the University of Iowa Hospitals and Clinics (UIHC) Department of Social Service (DSS) and the University of Iowa School of Social Work (UISSW) integrates faculty and students with clinicians for both practice and/or research internships. This program has endeavored to enhance practice and research social work through the development of (1) multiple student training programs offering both practice and research placement opportunities, (2) a jointly appointed faculty position between the UISSW and the UIHC DSS designed to improve researchers' access to and involvement with practice and practitioners' involvement in practice research, and (3) specialized student training programs including research projects in practice specialties. This project has helped clinicians conduct research, provided students with practical research experience within a clinical setting, and has increased the likelihood that both staff and students will participate in research.

Clinical Clerkship↗

PubMed1993

Effect of age on D2 dopamine receptors in normal human brain measured by positron emission tomography and 11C-raclopride.

Human postmortem and animal experimental results suggest a decline of the cerebral dopaminergic neuronal system with age. In this study, the radiotracer carbon 11-labeled-raclopride and positron emission tomography were applied to determine the effect of age on striatal D2 dopamine receptors in 32 healthy volunteer subjects (age range, 21 to 68 years; median, 31 years). An index of specific 11C-raclopride binding was calculated for putamen, caudate nucleus, and other brain regions in each subject. A significant decrease with age of the index for specific tracer uptake was found in putamen and caudate nucleus. The decrease was steep until 30 years, but slower afterward. After approximately 30 years of age, the decline of specific 11C-raclopride binding in putamen was found to be 0.6% per year. Our results suggest that D2 dopamine receptor binding sites (mainly postsynaptically located) decrease as a consequence of normal aging in parallel with the decline of the presynaptic nigrostriatal dopaminergic neuronal system.

Adult↗

PubMed1993

Cholylsarcosine, a new bile acid analogue: metabolism and effect on biliary secretion in humans.

BACKGROUND: Cholylsarcosine, the synthetic conjugate of cholic acid and sarcosine, is resistant to deconjugation-dehydroxylation during enterohepatic cycling in rodents and improves lipid absorption in a canine model of intestinal bile acid deficiency caused by distal intestinal resection. Experiments were performed to define its metabolism and effect on biliary secretion in humans. METHODS: The circulating bile acid pool was labeled with [14C]cholylsarcosine, and its turnover rate and biotransformation were determined by sampling bile daily. Cholylsarcosine (or cholyltaurine) was infused into the duodenum for 8 hours to define its effect on bile flow and biliary lipid secretion. RESULTS: Cholylsarcosine was lost rapidly from the enterohepatic circulation with a t1/2 of 0.5 days. The compound was not biotransformed by hepatic or bacterial enzymes. Cholylsarcosine had choleretic activity similar to that of cholyltaurine but induced more phospholipid and cholesterol secretion than cholyltaurine in four or five subjects. Infusion of cholylsarcosine (or cholyltaurine) at a rate averaging 0.6 mumol.min-1.kg-1 gave a biliary recovery of 0.2 mumol.min-1.kg-1; this value is the Tmax for active ileal transport of conjugated bile acids in humans. Laboratory tests for liver injury remained within normal limits. CONCLUSIONS: In humans, cholylsarcosine is not metabolized, is nontoxic, and has similar effects on biliary secretion as cholyltaurine. It appears safe to test in long-term studies the effect of cholylsarcosine on bile acid-deficiency states in humans.

Adult↗

PubMed1993

Physiologic and psychologic characteristics of an elderly population with chronic constipation.

OBJECTIVES: To characterize colorectal physiologic parameters and psychological profiles in subjects > or = 60 yr with chronic constipation who have not sought medical advice. METHODS: Colorectal physiologic studies and psychologic profiles were obtained in 18 self-identified constipated subjects and 17 nonconstipated control subjects. Constipation was defined as two or fewer bowel movements/week and/or defecatory difficulty for at least 6 months. All subjects underwent colonic transit with radiopaque markers, anorectal manometry and completed a self rated inventory assessing psychological distress (SCL-90-R). RESULTS: Slow colonic transit occurred in five constipated subjects. Pelvic floor dyssynergia and/or increased rectal compliance were found in nine subjects versus only two controls. One-third of constipated subjects scored in the top 10th percentile for global psychologic distress with higher scores for somatization, depression, and anxiety than control subjects. Neither physiologic nor psychologic abnormalities were predictable on the basis of patterns of bowel complaints. CONCLUSIONS: Colorectal physiologic and psychologic dysfunctions are common in elderly constipated subjects who do not seek medical attention for bowel dysfunction.

Aged↗

PubMed1992

Immunoscintigraphy of infections using 123I and 99mTc-labeled monoclonal antibodies. Advanced experiences in 230 patients.

Advanced experiences show an extremely high diagnostic potential in immunoscintigraphy of infections using monoclonal antigranulocytes antibodies (Mab). There was no hampering of the biological properties of the granulocytes after in vivo labeling with 123I or 99mTc-tagged Mabs. There were mostly identical findings and an equal functional behavior of the granulocytes observed with the use of different agents. Diagnosis of infections was made mostly within four to six hours p.i. 99mTc labeling is more advantageous than 123I because of better image quality, constant availability, and lower costs. 123I Mab 47 seems to be recommended in some cases of chronic osteomyelitis and spondylitis. No relevant antigenicity was observed in follow-up studies of testing HAMA serum levels. Only a few short-time reactions were seen after repeated administration of 99mTc Mab. There were no side effects and no allergic or adverse reactions. Despite these methodical advantages of the immunoscintigraphic detection of infectious and inflammatory lesions, this method should be further restricted to severe cases or patients in whom other methods would not be practicable or have failed. HAMA controls are continued in all our patients undergoing immunoscintigraphy.

Antibodies↗

PubMed1992

[Evaluation algorithm for eye movement patterns during a problem solving task].

Cognitive processes are accompanied by eye movements, which are interrupted by fixations of an almost infinite number of points in the visual field. To investigate these processes, a systematic analysis of those movements is required to structure the long sequences of fixations. This task is possible if there are interrelationships between the ongoing thought processes and the fixations. Such interrelationships may manifest themselves through certain patterns of eye movements. It often happens that subsets of visual points are being looked at repeatedly. This is because a cognitive connection among the subset's elements is being discovered or created by such repetition. The method presented here attempts to achieve automatic recognition of fixation point patterns. Its usefulness is demonstrated using data from an experiment where eye movements were recorded while subjects were solving Raven Test items. The method may be characterized as a variant of time series analysis for nominal data. It is suitable for non-numerical data in general.

Algorithms↗

PubMed1992

Psychological evaluation of patients with severe idiopathic constipation: which instrument to use.

We prospectively evaluated 38 patients with chronic severe idiopathic constipation who failed to respond to conventional therapy. Colonic transit studies, the Hopkins Symptom Checklist (SCL-90-R), and the Minnesota Multiphasic Personality Inventory (MMPI) were completed. Colonic transit studies identified 23 patients with slow transit and 15 with normal transit. Patients with normal transit constipation scored higher than those with slow transit on every scale of both the SCL-90-R and MMPI, but the SCL-90-R appeared to detect greater differences between the two groups. We conclude that the SCL-90-R is the preferred psychological instrument to evaluate patients with chronic severe constipation who fail to respond to conventional therapy. It provides information similar to the MMPI with which to measure behavioral profiles of patients in an office setting, and it can be completed and scored more rapidly.

Adult↗

PubMed1991

Lower extremity arterial disease in elderly subjects with systolic hypertension.

The ratio of ankle-to-arm systolic blood pressure (ankle/arm index or AAI) appears to be a non-invasive indicator of flow-significant atherosclerosis and may be a useful measure of burden of disease in a high risk population. The prevalence of lower extremity arterial disease (LEAD) was assessed by this method in the Systolic Hypertension in the Elderly Program (SHEP). Subjects were aged 60 and older with systolic blood pressure greater than 160 mmHg upon entry to the study. An AAI of 0.90 or less was considered indicative of flow-significant LEAD. The prevalence of LEAD by this method was 26.7% (50/187), while the prevalence of intermittent claudication (IC) was only 6.4% (12/187). Of those with IC, 66.7% (8/12) had confirmed LEAD. The prevalence of LEAD as measured by AAI increased with age in women and was associated with a history of current smoking and lower levels of high density lipoproteins. In this study population with systolic hypertension, LEAD, as measured by the AAI, is more prevalent than previously described in elderly populations and is associated with other risk factors for atherosclerosis.

Age Factors↗

PubMed1986

The effects of renal pelvic pressure elevation on isotope nephrography and renal transit time, an experimental study.

Radionuclide procedures are clinically used for assessing obstruction in dilated urinary tracts. The precise correlation of the isotope retention function with the level of the renal pelvic pressure is not known as yet. It was measured experimentally using 20 minipigs. By means of ureterostomies in situ reaching into the pyelon the 40 kidneys were subjected to varying pressures (seven to 62 cm. H2O) while the renal processing of 123-I-orthoiodine-hippuric-acid was recorded. The correlation of five radionuclide parameters with the pelvic pressure was computed: the time to the peak value of the isotope nephrography (t-max) and renal transit time correlated very well with high grade pelvic pressure (greater than 37 cm. H2O): r = 0.91 and 0.86 respectively, but much less well with low grade pelvic pressure (less than 37 cm. H2O): r = 0.73 and 0.62 respectively. The slope of the third phase of the isotope nephrography (tan-turn) and the time to the turning point of its tangent (t-turn) correlated only weakly with elevated renal pelvic pressure: r = 0.62 and 0.59 respectively. In conclusion, radionuclide procedures give excellent qualitative information on the level of pelvic pressure. They cannot, however, be used even as an indirect means for quantitatively assessing elevated renal pelvic pressure, which in urinary obstruction is thought to be one of the factors jeopardizing renal function.

Animals↗

PubMed1979