Search PubMed⌕ Search

Biomedical subjects

S Horn

Publications and source records attributed to S Horn.

At least 37 records · Page 2Linked to original sources
PubMed2000

Change in identity and self-concept: a new theoretical approach to recovery following a stroke.

OBJECTIVE: To determine whether respondents reported a change in identity following stroke. DESIGN: A cross-sectional comparison study of perceived changes in the self-concept of stroke respondents and matched hospital volunteers. A questionnaire was administered to stroke respondents in their own homes and to hospital volunteers in their work setting. PARTICIPANTS: Twenty-six first-time stroke survivors who had no severe communication, cognitive or perceptual difficulties or previous physical disability, and who had returned home from hospital up to two years previously. The comparison group were 26 hospital volunteers matched for age, gender and the time from which past self-concept was considered. MAIN OUTCOME MEASURES: Included the Hospital Anxiety and Depression Scale, Frenchay Activity Index and the Head Injury Semantic Differential Scale to assess past and present self-concept. RESULTS: Overall, individuals described themselves in more negative terms than prior to their stroke. They saw themselves as less interested, capable and independent, (p < 0.001) and less in control, satisfied and active (p < 0.05). They still saw themselves as friendly, calm, caring, hopeful and talkative. The overall self-concept of the comparison group remained positive and stable over a comparable time period. CONCLUSIONS: The stroke respondents reported a negative sense of self, reduced social activity and psychological morbidity despite inpatient and outpatient rehabilitation. Individuals following stroke may settle for a restricted future because of their expectations of life with a disability. Clinicians need to be aware of the meaning of the stroke within the life of each individual.

Adaptation, Psychological↗
PubMed1999

Cholestasis and liver cell damage due to hypersensitivity to erythromycin stearate--recurrence following therapy with erythromycin succinate.

Erythromycin is a frequently used antibiotic in patients with atypical respiratory infection and/or an allergy to penicillin. We report the case of a young woman who developed severe cholestasis and jaundice following treatment with erythromycin stearate. Two years later her general practitioner prescribed erythromycin succinate for pharyngitis. She experienced a severe second episode of jaundice and malaise. Different esters of erythromycin have been introduced to reduce side effects such as allergic reactions to erythromycin. The findings in our patient underline the fact that hypersensitivity is caused by the erythromycin molecule, independent from the type of esterification. Because of these side effects newer makrolides should be given preference over erythromycin.

Adult↗
PubMed1999

Oligonucleotide facilitators enhance the catalytic activity of RNA-cleaving DNA enzymes.

From in vitro selection studies, DNA structures have been found that cleave target RNA sequence specifically and show a certain similarity to the well-investigated hammerhead ribozymes. Such DNA enzymes are more resistant to nuclease-mediated degradation than RNA enzymes. On the other hand, their cleavage activity is lower than the activity of hammerhead ribozymes. In the present study, we improved the activity of DNA enzymes by adding oligonucleotide facilitators complementary to the 5' and the 3' ends of the substrate to the cleavage reaction. DNA enzyme activity in vitro was monitored under multiple turnover conditions using short RNA model substrates. We have shown that oligonucleotide facilitators strongly enhance the multiple turnover activity of the DNA enzyme reaction. In one of our model systems with a suitable facilitator combination, we were able to observe a more than 200-fold enhancement of the k(cat)/Km value. The comparison of two DNA enzyme-substrate systems showed that the principal effects of the facilitators were independent of the substrate sequence. However, the degree of facilitator effect was noticeably dependent on the basic catalytic efficiency of DNA enzymes. Furthermore, the efficiency of the DNA enzyme reaction with facilitator was compared with the reaction of a DNA enzyme with a stem sequence extended by the sequence of the facilitator. The multiple turnover activity of such a "long DNA enzyme" is higher than the activity of the short DNA enzyme without facilitators. However, when compared with the multiple turnover reactions of the short DNA enzyme with facilitator, the reaction with the long DNA enzyme is considerably slower. The results obtained with our model systems demonstrate that oligonucleotide facilitators enable DNA enzymes to act as effective multiple turnover catalysts by cleavage of RNA substrates.

Base Sequence↗
PubMed1998

First description of recurrent pericardial effusion associated with borrelia burgdorferi infection.

Lyme disease is well known for affecting the myocardium in the form of carditis and dilated cardiomyopathy. Pericardial effusion associated with Lyme disease has not been described as yet. This article demonstrates a case of a female patient, 54 years of age, with Borrelia burgdorferi infection and associated pericardial effusion. Recurrent pericardiocenteses as well as conventional treatment of the condition were without success. Diagnosis of Borrelia infection and subsequent treatment with ceftriaxone led to permanent restitution of the pericardial effusion.

Borrelia burgdorferi Group↗
PubMed1998

[Critique of continuing medical education from the viewpoint of participants. Results of an evaluation of didactic seminars of the Academy of Continuing and Graduate Medical Education of the Hessen Federal Association].

In cooperation with the chair of academy of vocational training and educational planning of the University of Technology Darmstadt the academy planned and realized a systematic evaluation concerning participants's opinion and criticism. A half-standardized questionnaire was developed, tested and applied according to the rules and recommendations of the German medical association. Between 9/94 and 11/98, feedback from 121 of the academy's seminars was received. Most seminars were judged positively in view of clarity and stimulation of thoughts while there was considerably less praise for the contribution of self-information and the possibilities of communicating and interacting. With regard to the lecture's practical relevance most seminars were judged positively. Media design and management was considered insufficient by most of the participants, as were time management and pre-information. The idea of examining the effect of learning was rejected by most of the students: Better media were desired, as were more case studies and literature references.

Curriculum↗
PubMed1997

Effect of steroid treatment on the migration behaviour of neutrophils in patients with early rheumatoid arthritis.

The influence of methylprednisolone on the migratory characteristics of neutrophil granulocytes was investigated in 10 patients with early rheumatoid arthritis (RA) and compared to 12 controls. The migration of neutrophils was measured with a whole-blood membrane filter assay with and without stimulation by the chemoattractant N-formyl-methionyl-leucyl-phenylalanine (fMLP). Total migration index (TMI), distribution characteristics (DC) and the product of TMI and DC (neutrophil migratory activity; NMA) served to characterize the migratory behaviour of neutrophils. The data demonstrated an increased polymorphonuclear leucocyte (PMN) migration in patients with early RA, indicating a bystander role of PMNs in inflammatory joint injury. Treatment with methylprednisolone reduced significantly the penetration depth (DC) of neutrophils, but did not influence the number of migrating cells (TMI). The unstimulated NMA was significantly reduced due to the marked DC reduction, whereas steroids did not influence the stimulated NMA of neutrophils. A significant reduction in PMN penetration depth was demonstrated only after a steroid therapy of at least 10 days, suggesting that a longer period of steroid therapy is necessary to provide effective inflammatory control.

Aged↗
PubMed1997

End-stage renal failure from mushroom poisoning with Cortinarius orellanus: report of four cases and review of the literature.

Mushrooms of the ubiquitous Cortinarius species (Cs) contain nephrotoxins that can cause acute and chronic renal failure by an unknown pathomechanism. Typical is a long symptom-free interval before the onset of clinical disease. A causal form of therapy is not known. Early hemodialysis can improve the prognosis of this potentially life-threatening condition. Diagnosis of Cs poisoning can be made by detecting the responsible toxin--orellanine--in plasma or renal tissue by fluorimetry after thin-layer chromatography or by identifying the spores of left-over mushrooms as Cs. Renal histology shows nonspecific changes such as tubular dilatation and flattening of the epithelium and signs of interstitial edema followed by interstitial fibrosis. We present four cases of Cs poisoning with different outcomes and a review of the literature.

2,2'-Dipyridyl↗
PubMed1997

Functional magnetic resonance imaging of human renal allografts during the post-transplant period: preliminary observations.

Graft dysfunction is a common occurrence during the first weeks following renal transplantation. The current study was designed to evaluate the potential of renal magnetic resonance (MR) perfusion imaging to differentiate acute allograft rejection (AAR) from acute tubular necrosis (ATN) during the post-transplant period. Twenty-three consecutive patients with clinically suspected ATN and/or AAR and eight consecutive control patients (asymptomatic, serum creatinine concentration < 1.5 mg/dL) underwent MR perfusion imaging of the renal allograft within 64 days after transplantation. Histopathology was obtained in all cases with clinical suspicion of ATN or AAR. Sixty sequential fast gradient-recalled-echo MR images were acquired in each patient after intravenous administration of gadolinium-DTPA (0.1 mmol/kg). Histopathology revealed 6 patients with pure AAR, 4 patients with a combination of AAR and ATN, 12 patients with ATN and 1 patient with normal findings. Kidney graft recipients with normal renal function showed a moderate increase in signal intensity (SI) of the renal cortex and medulla after administration of contrast agent followed by an immediate and short decrease in SI of the medulla (biphasic medullary enhancement pattern). The increase in cortical SI of patients with AAR was significantly smaller (61 +/- 4% increase above baseline) than that measured in normal allografts (136 +/- 9% increase above baseline) (p < 0.05) and patients with ATN (129 +/- 3% increase above baseline) (p < .05). Patients with ATN had a slightly delayed and diminished cortical enhancement and an uniphasic and lesser medullary enhancement pattern compared to that observed in normal allografts (p < 0.05). A close correlation (r = 0.72) was found between serum creatinine concentration levels and changes in SI. Thus, MR imaging results and histopathology were in agreement in 22 of 23 patients (96%). MR perfusion imaging of renal allografts can be used to noninvasively differentiate ATN from AAR during the post-transplant period, and may also be helpful in cases were covert AAR is superimposing ATN during a phase of anuria. Patients with ATN can be separated from normals in the majority of cases as reflected by an uniphasic medullary enhancement pattern.

Adult↗
PubMed1997

Effects of a new positioner on the precision of hip bone mineral density measurements.

In an attempt to reduce patient positioning errors, the authors tested the use of a new hip-specific positioning tool, OsteoDyne's Hip Positioner System (HPS). The HPS is an "A" frame splint designed to abduct both legs approximately 15 degrees to hold them in full extension at the hips and knees and to lock the feet in a neutral position. Seventy volunteer women aged 35-82 years were randomly assigned in two age-matched groups (mean age 56 years). Each group underwent two consecutive femur dual X-ray absorptiometry (DXA) scans with intermediate repositioning using the HPS system and two others utilizing the standard hip positioner provided with Hologic and Lunar scanners. One technician performed all scans using a Hologic QDR 1000-Plus and Lunar DPX-Plus densitometer. One hundred and fifty volunteer women aged 50-84 years (mean age, 64 years) were recruited in a multicenter study for the assessment of precision. Each subject underwent three consecutive femur DXA scans with intermediate repositioning using the HPS system. The coefficient of variation (CV) was significantly improved at the femoral neck by the use of the HPS with 0.7 versus 1.2 with the Hologic densitometer but only moderately altered at other sites. Similar results were found with the Lunar densitometer with improvement of precision at the femoral neck, 0.8 versus 1.8 with a similar trend but no significant difference at the other regions. No statistical difference was noted between the femoral neck BMD measured with the HPS system and with the standard positioners in either group. The mean precision of data obtained on the QDR 1000+ was 0.8% (range 0.1-1.4) for the femoral neck BMD, 1.1% (range 0.1-3.0) for the trochanter BMD, 2.3% (range 0.2-5.2) for Ward's triangle BMD, and 0.8% (range 0.1-1.9) for the total femur BMD. The mean precision of data obtained on the QDR 2000 was 0.7% (range 0.1-2), 1% (range 0.1-4.9), 2.6% (range 0.3-5.7), and 0.7% (range 0.1-1.8), respectively. In conclusion, data obtained with the new OsteoDyne's HPS seem capable of reducing patient positioning errors for the hip measurement. Its use is likely to improve confidence in hip bone mineral density measurements.

Absorptiometry, Photon↗
PubMed1997

Treatment of depression in older primary care patients in health maintenance organizations.

OBJECTIVE: To examine whether older HMO patients with depression are treated differently than younger patients in terms of diagnosis, treatment by specialty provider, and pharmacotherapy. DESIGN: Chart-review, Cross sectional study. SETTING AND PARTICIPANTS: Patients were selected from six HMOs in the United States who had one or more of five medical diagnoses: arthritis, asthma, otitis media, epigastric pain/ulcer, and hypertension, (n = 9143). From this group, chart diagnoses and pharmacy records were used to identify patients who also had a diagnosis of depression (n = 416) or who had a diagnosis of depression and/or treatment with antidepressant medication (n = 1286). MEASUREMENT: Medical records and computerized service and pharmacy records were reviewed to obtain diagnoses, office visits by provider type, and psychiatric medication prescription counts. RESULTS: Significant differences were found in treatment of depression for older versus younger patients. Although depression was identified at a similar rate for both groups, older patients received fewer mental health specialty visits and fewer prescriptions for SSRI antidepressants. Older patients with a diagnosis of depression were more likely to be treated with benzodiazepines (49.2% of older vs. 33.2% of younger) though they were less likely to receive long half-life benzodiazepines. CONCLUSIONS: Psychotropic medication management is an important target for improving quality of care for older patients with depression in HMOs. Decreasing inefficient minor tranquilizer use and increasing use of newer antidepressant medications may lead to improved outcomes for older depressed adults.

Adult↗
PubMed1996

An adenovirus mutant that replicates selectively in p53-deficient human tumor cells.

The human adenovirus E1B gene encodes a 55-kilodalton protein that inactivates the cellular tumor suppressor protein p53. Here it is shown that a mutant adenovirus that does not express this viral protein can replicate in and lyse p53-deficient human tumor cells but not cells with functional p53. Ectopic expression of the 55-kilodalton EIB protein in the latter cells rendered them sensitive to infection with the mutant virus. Injection of the mutant virus into p53-deficient human cervical carcinomas grown in nude mice caused a significant reduction in tumor size and caused complete regression of 60 percent of the tumors. These data raise the possibility that mutant adenoviruses can be used to treat certain human tumors.

Adenovirus E1B Proteins↗
PubMed1996

Abnormal axonal inward rectification in diabetic neuropathy.

An abnormal axonal membrane conductance might contribute to human diabetic neuropathy. To test this idea, we have compared the threshold changes produced by long-lasting (100-200 ms) de- and hyperpolarizing currents applied to median motor and sensory axons at the wrist in 63 diabetic patients with those from 50 normal controls and 27 amyotrophic lateral sclerosis (ALS) patients. Averages of the threshold electrotonus plots for motor and sensory axons of diabetic patients showed more subexcitability during, and slower recovery following, the application of hyperpolarizing currents. Such alterations have been previously found in isolated rat nerves after inhibition of axonal inward rectification by means of cesium ions. The abnormalities in diabetics were positively correlated with the age of patients and the presence of neuropathy. Threshold electrotonus seen in diabetes differed strongly from the effects of acute ischemia and were unlike changes recorded in ALS. The data indicate that an abnormal inward rectification of peripheral axons is associated with diabetic neuropathy. A better understanding of the neurobiology of this conductance might provide information about the pathophysiology of this disease.

Adult↗
PubMed1996

KATP channel opening does not contribute significantly to the vasodilatory effect of SH-group-containing ACE inhibitors.

Angiotensin-converting enzyme (ACE) inhibitors are widely used in the management of hypertension, heart failure, and nephropathy. It has been suggested that ACE inhibitors containing the sulfhydryl group (SH) have an additional effect on KATP channels. To prove this hypothesis, we studied the effects of the SH-containing ACE inhibitors, captopril and zofenopril, on KATP channel opening of bovine coronary arteries and guinea pig thoracic aortas. Bovine coronary arteries were precontracted with the thromboxane A2 analogue, U46619, and guinea pig thoracic aortas were precontracted with phenylephrine and then relaxed with either captopril or zofenopril (n = 8). Inhibition of KATP channel opening with glibenclamide moderately attenuated the zofenopril-induced relaxation of guinea pig thoracic aorta. However, in the bovine coronary arteries, the relaxing effect of both captopril and zofenopril remained uneffected by glibenclamide. In experiments with enalapril (a non SH-containing ACE inhibitor; n = 6) on guinea pig thoracic aortas, no effect on KATP channels could be seen. From our experiments, we conclude that the postulated opening of KATP channels by SH-group-containing ACE inhibitors contributes little to the vasodilation of guinea pig thoracic aortas caused by ACE inhibitors, and that SH groups have no influence upon KATP channels of bovine coronary arteries.

Adenosine Triphosphate↗