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Biomedical subjects

F Herrmann

Publications and source records attributed to F Herrmann.

At least 37 records · Page 2Linked to original sources
PubMed2001

Properties of sensors based on shear-horizontal surface acoustic waves in LiTaO3/SiO2 and quartz/SiO2 structures.

Acoustic wave devices based on waveguide modes with shear-horizontal polarization, i.e., Love modes, are very promising for sensor application, especially in liquid environments. They can be used for the determination of liquid density and viscosity as well as for chemical sensors. Up to now, several systems have been reported based on standard ST quartz. Those devices lack temperature stability, which is essential for field application. Thus, temperature-compensated systems based on different Y-rotated quartz and lithium tantalate (LiTaO3) plates with SiO2 guiding layers have been investigated. Temperature behavior as well as relevant acoustic properties were considered. Furthermore, experimentally determined data for device sensitivity are compared with theoretical predictions from numerical calculations.

Journal Article↗
PubMed2001

The training analysis at a time when theory is in short supply.

The author discusses the risks confronting the training analysis when original theoretical production is lacking. In his view, little progress has been made since Freud's time in establishing a general science of the psyche based on Freud's interpretive method. What has been transmitted is stated to be not Freud's method of discovery but the knowledge thereby produced, which has been handed down in the form of doctrines, defined as theory presented as psychic fact. Hence analyses tend to apply theories rather than to discover unconscious. Some of today's most common interpretational aberrations are described, and the author shows the powerful suggestive effect on patients of using doctrines as metaphors of psychic life. Where such a training analysis is reinforced by a like form of theoretical teaching and supervision, candidates may uncritically assimilate the relevant theory. The author uses his concept of the reality-providing circuit to show how belief in a doctrine imparted by the training analysis makes that doctrine appear as the ideological basis of psychoanalytic knowledge. He finally notes that, theories being essentially heuristic instruments and not bodies of acquired information, the consequence of the current dearth of theories, which have degenerated into doctrines, is that the training analysis itself has come to constitute the theory of training in many institutes.

Education↗
PubMed2000

Refrigerator content and hospital admission in old people.

We assessed whether the refrigerator contents of elderly people could be related to subsequent admission to hospital. 132 patients aged over 65 years had a thorough assessment of their refrigerator contents and the numbers and dates of admission were recorded. Elderly people with empty refrigerators were more frequently admitted (p=0.032) in the month after assessment and three times sooner than those who did not have empty refrigerators (34 vs 100 days, p=0.002).

Aged↗
PubMed2000

Immediate causes of death of demented and non-demented elderly.

OBJECTIVE: To investigate the immediate causes of death, in autopsied demented and non-demented elderly. DESIGN: Retrospective clinicopathologic correlations. SETTING: Acute and intermediate care geriatric hospital. PARTICIPANTS: 342 hospitalized demented and non-demented elderly (mean age 84.94 +/- 6.9 years) who underwent consecutive postmortem examinations: 120 demented patients with either vascular dementia (VaD, n = 34), mixed dementia (MD, n = 65) or Alzheimer's disease (AD, n=21) neuropathologically confirmed and 222 nondemented elderly. RESULTS: Primary causes of death were similar in both demented and non-demented patients; the commonest were cardiovascular disease and bronchopneumonia. Cardiac causes of death and especially cardiac failure were more frequent in VaD than in AD or MD (respectively P = 0.027 and 0.005). Dementia was an underlying but never a primary cause of death. CONCLUSIONS: Immediate causes of death are similar in elderly demented and non-demented patients.

Aged↗
PubMed2000

Midazolam sedation for upper gastrointestinal endoscopy in older persons: a randomized, double-blind, placebo-controlled study.

OBJECTIVES: To investigate the benefits and risks of using midazolam for sedation during upper gastrointestinal endoscopic procedures in older persons. DESIGN: Randomized, double-blind, placebo-controlled study. SETTING: A 304-bed geriatric university hospital. PATIENTS: Sixty-five geriatric inpatients (mean age 84 +/- 7) undergoing gastroscopy. INTERVENTION: Sedation with either midazolam (30 microg/kg IV) or saline (placebo). All patients received supplemental oxygen during the procedure (2 L/minute). MEASUREMENTS AND RESULTS: Patients' recall of their tolerance to the exam (categorical scale) and pain score were significantly in favor of midazolam at 2 and 24 hours. Multivariate analysis at 2 hours showed that midazolam increased the probability of good tolerance (odds ratio (OR) = 19.3; 95% confidence interval (CI) 2.2-170.4, P = .008). Circumstantial amnesia occurred at 24 hours in 84% (midazolam) versus 27% (placebo) (P < .001). With midazolam, mean sedation time was 83 +/- 13 minutes and mean arterial pressure (MAP) was about 10 mm Hg lower without clinically significant hypotension. Hypoxemia (SaO2 < 92%) was more frequent in the midazolam group after endoscopy (44% vs. 18%, P = .033), but no major desaturation was observed. Cognitive function (Mini-Mental State Exam, MMSE) was similar before and 2 and 24 hours after the exam in both groups. Acute confusion was observed in two patients (1 midazolam, 1 placebo). In multivariate analysis, midazolam was associated with a higher risk of hypoxemia after endoscopy (OR = 3.5; 95% CI 1.1-10.8, P = .029) but not of confusion. CONCLUSIONS: Under adequate surveillance, the benefits in terms of tolerance to the procedure of low-dose midazolam for upper gastrointestinal endoscopic sedation outweigh the risks in older people.

Aged↗
PubMed2000

[Prevalence of the activated protein C resistance in indigenous and Black populations of the western Venezuela].

The Activated Protein C Resistance (APCR) is the common phenotype of Factor V Leiden (arg506gln), which is considered as a thrombotic risk factor. The aim of this study was to determine the prevalence of APCR and its association with Factor V Leiden in indian and black populations from Zulia State in western Venezuela. Blood samples were taken from 80 Yukpa indians from Sierra de Perijá and 91 black individuals from the southeast of Lago de Maracaibo. APCR was determined by the Dahlback's method with the modifications of Jorquera et al. and Trossaert et al. The results were expressed as n-APC-SR (positive value < or = 0.75). Factor V Leiden genotype was identified by PCR and restriction analysis standard methods at the Institute of Human Genetics (Greifswald, Germany). No significative difference was found between n-APC-SR from indians (mean +/- SEM 1.13 +/- 0.02, CI 95% = 1.07-1.19) and black people (1.07 +/- 0.02, CI 95% = 1.03-1.12). APCR prevalence from indians was 1.25% (1 out of 80) who was heterozygote case for F V Leiden and 4.4% (4 out of 91) from blacks (one case was heterozygous for F V Leiden). No thrombotic event personal or familial was demonstrate. Our data represent the first report related to the association between APCR and F V Leiden in venezuelan indian and black individuals. APCR without the Factor V Leiden expression suggest a different type of mutation in the Factor V molecule. In spite of high endogamy in the indian group, we can not discard the role of foreign genes in both populations. The determination of the prevalence of this phenotype and its molecular marker in various ethnic groups is important for the interpretation of their role as risk factors for thrombotic disease.

Activated Protein C Resistance↗
PubMed1999

[Epidemiological analysis of accidental falls by the elderly in Zurich and Geneva].

The purpose of the study was to determine the prevalence rate of fallers (PRF%) and fall-related consequences among the elderly according to age, gender and setting. Data derive from a cross-sectional study on dementia, depression and handicaps among the elderly, carried out between 1995 and 1996. Elderly people aged 65 and over living in Zurich or Geneva were considered eligible for the study. By means of the Canberra Interview for the Elderly, 921 subjects' and/or informants' interviews were completed. The subjects were classified as a faller if the subject and/or informant reported a fall in the year prior to the interview. Overall PRF% amounted to 27.8% and was higher to a statistically significant degree among females (30.9%) than males (22.5%). Gender difference in PRF was found only among the non-institutionalized elderly. Age-specific PRF increased significantly with the age of the elderly. However, this increase was observed only among male subjects. 143 subjects (PRF 17.1%) have fallen once and 101 (PRF 9.9%) two or more times. Females showed a substantially higher propensity to recurrent falls (age-adjusted OR 1.86; 95% confidence interval 1.11-3.10). While the risk of suffering two or more falls increased with age, it did not increase among one-time fallers. Residents of nursing homes had significantly higher risk of falling as compared with home-dwelling subjects (age-adjusted OR 2.46; 95% confidence interval 1.04-5.78). Every second fall caused fall-related consequences. 9.1% of all falls led to fall-related fracture. The risk of suffering fall-related consequences depended on neither age nor gender. One third of fallers reported fear of further falling. Falls among the elderly occur often and contribute substantially to morbidity.

Accidental Falls↗
PubMed1999

Properties of shear-horizontal surface acoustic waves in different layered quartz-SiO2 structures

Acoustic wave devices based on waveguide modes with shear-horizontal polarisation in Y-rotated quartz plates are very promising for sensor application. Up to now, several systems have been reported based on standard ST-quartz. Those devices lack temperature stability, which is essential for field application. However, appropriate combinations of crystal cut angle and SiO2 overlay thickness should provide temperature compensation. Thus, different systems based on Y-rotated quartz plates with cut angles between 30 and 42.75 degrees have been investigated. First- and second-order temperature coefficients of frequency change have been calculated and measured. Moreover, properties are compiled that are relevant for the device design, i.e. acoustoelectric coupling coefficients, effective dielectric constants, and phase as well as group velocities. In summary, device configurations could be identified that combine temperature stability comparable to that of surface skimming bulk waves in the AT-cut, a suitable coupling coefficient, and high gravimetric sensitivity.

Journal Article↗
PubMed1998

[Antibiotic utilization in a university geriatric hospital and drug formularies].

UNLABELLED: Inappropriate use of antibiotics needlessly increases drug expenditures, enhances the emergence of antimicrobial resistance in hospitals and heightens the risk of toxicity, especially in elderly patients. This population is very sensitive to inappropriate drug treatment because of pharmacological and pharmacokinetic changes, reduced homeostatic functional reserve, multiple underlying diseases (e.g. renal failure) and polypharmacy (leading to drug interactions and side effects). To assess antibiotic prescription in a geriatric university hospital with a restrictive drug formulary, we analyzed data extracted from the Drug Kardex (a standardized synthesis of all prescribed medicines) during 4 cross-sectional drug utilization studies, carried out in 1996 on all hospitalized patients. RESULTS: 1138 patients' Kardex have been analyzed. 20% of these patients received one or more antibiotic treatments. In total 268 antibiotic treatments (AB) were prescribed, 84 in March, 44 in June, 71 in September and 66 in December. 21 different AB were used, the five most frequently prescribed AB being amoxycillin-clavulanic acid, ceftriaxone, ciprofloxacin, metronidazole, co-trimoxazole and representing 69% of all AB. Most of the AB were given in an oral form (63%) and in one standard dose. Dose adjustments in these very old patients with a high percentage of renal failure were apparently rarely done. The choice of rather broad spectrum AB may be due to the fact that obtaining an appropriate bacteriological culture from elderly patients with respiratory tract infections is difficult, but was also due to a lack of diagnostic subcategorization of the infection. Undesirable effects of the restrictive drug formulary were also noted: large utilization of ciprofloxacine (only fluoroquinolone on the hospital's drug list) for urinary tract infections instead of other more appropriate antibiotics. CONCLUSION: It is important to individualize antibiotic drug therapy with respect to underlying diseases, site of infection and antibiotic sensitivity patterns, especially in elderly patients. Restrictive hospital drug formularies are not sufficient to assure rational drug use, but should be associated with broader educative measures.

Aged↗
PubMed1998

Exposure of Allan Hills 84001 and other achondrites on the Antarctic ice.

The enrichment of F on Antarctic meteorites is the result of their exposure to the atmosphere, and its measurement allows a subdivision of the terrestrial age into a duration of exposure on the ice and the time a meteorite was enclosed by the ice. In many cases, the periods of surface exposure are only small fractions of the terrestrial ages of meteorites collected in Antarctica. The enrichment of F on the surfaces of Antarctic achondrites was investigated by means of nuclear reaction analysis (NRA): scanning proton beams with an energy of 2.7 and 3.4 MeV were used to induce the reactions 19F(p, alpha gamma)16O and 19F(p,p gamma)19F, respectively. Gamma signals proportional to the F content were measured. The following Antarctic achondrites were investigated: Martian meteorite ALH 84001; diogenite ALHA77256; the eucrites ALHA81011 and ALHA78132; and in addition, the H5 chondrite ALHA79025. For ALH 84001, our data indicate a period of exposure on the ice of <500 years. Thus, this specimen was enclosed in the ice >95% of its terrestrial age of 13 000 years.

Antarctic Regions↗
PubMed1998

Lack of association of Graves' disease with the A2 allele of the interleukin-1 receptor antagonist gene in a white European population.

OBJECTIVE: To assess whether the A2-type IL-1RA polymorphism is associated with Graves' disease and Graves' ophthalmopathy. Several reports have described a genetic association between the A2 allele of the interleukin-1 receptor antagonist (IL-1RA) gene and certain inflammatory and autoimmune diseases, suggesting that certain loci within the IL-1-related genes may modulate the autoimmune inflammatory response. Recently, we demonstrated marked differences in the expression and regulation of IL-1RA gene and protein between orbital fibroblasts derived from patients with active Graves' ophthalmopathy and healthy individuals. DESIGN: A total of 144 white European patients with Graves' disease were genotyped to compare their IL-1RA A2 allele frequency with that of 174 healthy controls. METHODS: The polymerase chain reaction was used to amplify the pentallelic variable-number tandem-repeat locus in intron 2 of the IL-1RA gene. RESULTS: We found no significant differences in IL-1RA A2 allele frequencies (0.20 and 0.26 respectively) and IL-1RA A2 carriage rates (31% and 40% respectively) between patients with Graves' disease and the control group. Moreover, presence or absence of Graves' ophthalmopathy in patients with Graves' disease was not related to significant differences in IL-1RA A2 allele frequencies and IL-1RA A2 carriage rates. CONCLUSIONS: Our data do not support an association between the IL-1RA A2 allele and Graves' disease or Graves' ophthalmopathy in our study population. Thus the A2-type IL-1RA gene polymorphism does not appear to indicate an increased susceptibility to develop Graves' disease and Graves' ophthalmopathy. Mechanisms unrelated to the IL-1RA A2 allele may be responsible for altered IL-1RA production within the orbital tissues in Graves' ophthalmopathy.

Alleles↗
PubMed1997

In vivo drug-selectable genes: a new concept in gene therapy.

Chemoresistance genes, initially considered to be a major impediment to the successful treatment of cancer, may become useful tools for gene therapy of cancer and of genetically determined disorders. Various target cells are rendered resistant to anticancer drugs by transfer of chemoresistance genes encoding P-glycoprotein, the multidrug resistance-associated protein-transporter, dihydrofolate reductase, glutathione-S-transferase, O6-alkylguanine DNA alkyltransferase, or aldehyde reductase. These genes can be used for selection in vivo because of the pharmacology and pharmacokinetics of their substrates. In contrast, several other selectable marker genes conferring resistance to substrates like neomycin or hygromycin can only be utilized in tissue culture. Possible applications for chemoresistance genes include protection of bone marrow and other organs from adverse effects caused by the toxicity of chemotherapy. Strategies have also been developed to introduce and overexpress nonselectable genes in target cells by cotransduction with chemoresistance genes. Thereby expression of both transgenes can be increased following selection with drugs. Moreover, treatment with chemotherapeutic agents should restore transgene expression when or if expression levels decrease after several weeks or months. This approach may improve the efficacy of somatic gene therapy of hematopoietic disorders which is hampered by low or unstable gene expression in progenitor cells. In this article we review preclinical studies in tissue culture and animal models, and ongoing clinical trials on transfer of chemoresistance genes to hematopoietic precursor cells of cancer patients.

Animals↗
PubMed1997

The abundant presence of Söderström bodies in cytology smears of fine-needle aspirates contributes to distinguishing high-grade non-Hodgkin's lymphoma from carcinoma and sarcoma.

Söderström bodies, also termed lymphoglandular bodies (LGB) and detectable in fine-needle aspiration cytology smears, have long been accepted as indicative of lymphoid tissues. To investigate the validity of this association, we examined 588 cytologic smears from high-grade non-Hodgkin's lymphoma (NHL), carcinoma, and sarcoma. Slides with lymphocytes in the vicinity of carcinoma and sarcoma cells had been excluded. Two independent observers scored smears to number, size, color, form, and smear background of the LGB. In 68 of 359 (19%) nonlymphoid malignancies rare (defined as < 1 LGB per high-power field) or occasional LGB (defined as 1-20 LGB per high-power field) were detectable. Half of these tumors consisted of melanomas, small cell lung carcinomas, and teratomas; the other half encompassed undifferentiated sarcomas. However, none of the smears obtained from carcinoma or sarcoma tissue had abundant LGB (defined as > 20 LGB per high-power field). When number of LGB was estimated to be abundant, the sensitivity for diagnosing a lymphoma was 54%; however, specificity was 100%. The difference in showing LGB between high-grade NHL and carcinoma/sarcoma was highly significant (p = 0.0001). The presence of abundant LGB in cytologic smears strongly suggests the diagnosis of lymphoma, while the absence of LGB nearly excludes this diagnosis. No trends were observed with the other criteria which were tested. LGB in aspiration cytology smears from malignant tumors thus represent a useful tool to distinguish high-grade NHL from carcinoma and sarcoma.

Biopsy, Needle↗