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Biomedical subjects

H Pohl

Publications and source records attributed to H Pohl.

At least 19 recordsLinked to original sources
PubMed1990

Medication prescribing errors in a teaching hospital.

A study of prescribing errors committed by physicians that occurred in a tertiary-care teaching hospital is reported. From a total of 289 411 medication orders written during the 1-year study period, 905 prescribing errors were detected and averted, of which 522 (57.7%) were rated as having potential for adverse consequences. The overall detected error rate was 3.13 errors for each 1000 orders written and a rate of 1.81 significant errors per 1000 orders. The error rate (4.01 per 1000 orders) was greatest between 12 pm and 3:59 pm. First-year postgraduate residents were found to have a higher error rate (4.25 per 1000 orders) than other prescriber classes, and obstetrics/gynecology services (3.54 per 1000 orders) and surgery/anesthesia services (3.42 per 1000 orders) had greater error rates than other services. The study results demonstrate the significant risk to patients from medication prescribing errors. Educational, operational, and risk-management activities should include efforts directed at reducing the risk to patients from prescribing errors.

Hospital Bed Capacity, 500 and over↗
PubMed1990

Increase in luteinizing hormone content occurs in cultured human fetal pituitary cells exposed to gonadotropin-releasing hormone.

To investigate the mechanisms by which GnRH regulates LH production during intrauterine life, dispersed pituitary cells from second trimester human fetuses were cultured on extracellular matrix-coated plates for 48 h. Exposure of cells to 3 x 10(-10) mol/L GnRH for 1-48 h significantly increased cumulative LH secretion compared to that in respective controls (P less than 0.01). The rate of GnRH-stimulated LH release was accelerated during the first 6 h, after which it declined to a level similar to that of basal release. This phenomenon was associated with a decrease in the GnRH concentration of the medium. Exposure of cells to GnRH (3 x 10(-10) to 10(-6) mol/L) for 48 h induced a dose-dependent elevation of total LH which correlated with an increase in releasable, but not cellular, LH. Desensitization to GnRH (10(-7) mol/L) occurred when cells were cultured with pharmacological amounts of GnRH for 48 h. These results indicate that GnRH induces the increase in total and releasable LH in human fetal pituitary cells. These cells also appear to inactivate GnRH. Thus, GnRH may increase LH production in the human fetal pituitary and the pituitary receptor mechanism may be involved in GnRH action on LH release during intrauterine life.

Cells, Cultured↗
PubMed1989

Vitamin C intake influences the bleomycin-induced chromosome damage assay: implications for detection of cancer susceptibility and chromosome breakage syndromes.

Supplementation with 1 g of vitamin C (ascorbic acid) per day decreased the amount of chromosome damage induced in lymphocytes by an exposure to bleomycin during the last 5 h of cell culture. We did not see such changes in lymphocytes from control individuals samples at the same time but not taking vitamin C supplements. This bleomycin assay has been proposed as a test for cancer susceptibility. A similar assay for genetic instability may be useful in detecting heterozygotes for chromosome-breakage syndromes (for example, Fanconi anemia or ataxia telangiectasia). Even though our sample size is small and our results should be interpreted cautiously, statistically significant effects were found with vitamin C supplementation. It would, therefore, be prudent to consider dietary and perhaps other lifestyle factors when interpreting of results from this bleomycin assay and related assays for genetic instability.

Ascorbic Acid↗
PubMed1985

Lithium suppresses hibernation in the Turkish hamster.

Daily uptake of lithium salt (LiCl) in the drinking water at a rate of over 100 micrograms/g b.wt (or 2.4 mEq/kg) reduced or suppressed natural torpidity (hibernation) in the Turkish hamster (Mesocricetus brandti). The data indicate a direct influence of lithium on clock-related functions controlling the hibernation process rather than indirect effects by preventing gonadal regression and thereby also hibernation.

Animals↗
PubMed1985

The circadian system of the Turkish hamster, Mesocricetus brandti: responses to light.

The circadian system of the Turkish hamster controlling wheel-running activity responded to single 1-hr light pulses and to repeated 1-hr pulses in a similar way as that of Syrian hamsters studied previously. At constant light of 100 lx, the period length (tau) of the freerunning activity rhythm of Turkish hamsters was longer and the activity time (alpha) was shorter than that of Syrian hamsters. Among individuals, the ability of the system to be entrained by one 1-hr light pulse per cycle was related to the range (advance plus delay amplitude) of the phase response curve (PRC) derived from single light pulses and to the compression of alpha caused by the pulse Zeitgeber. The data support the hypothesis derived from experiments on Syrian hamsters that the range of the PRC is functionally related with alpha, possibly reflecting the phase relations (coupling) between two oscillators.

Animals↗
PubMed1985

A contribution regarding the Rett syndrome.

Andreas Rett described a "cerebral atrophic syndrome accompanying hyperammonemia" for the first time in 1966, and by 1983 over 80 such cases had been identified and described not only in Austria but also in other countries. If the information at our disposal is correct, we have reported on what we believe is the first case of a patient with a definite Rett syndrome in the German Democratic Republic. We are, regrettably, still unable to contribute decisively to the clarification of the etiology and pathogenesis of the disease, but will, through further publications and papers at pediatric and child-neuropsychiatric meetings, continue to spread the knowledge of the symptomatology. It is remarkable that in the present case neither computer tomography nor electroencephalography showed definite abnormalities despite much effort. Definite proof of cerebral atrophy cannot, therefore, yet be furnished. But we still have no doubt that our diagnosis is correct. We intend, within the framework of a joint study being conducted by the University Pediatric Hospital Rostock and the Ludwig Boltzmann Institute, Vienna, as part of the scientific and technical cooperation between the Republic of Austria and the German Democratic Republic, to investigate further the epidemiology and etiology of this disease in cooperation with our Departments of Metabolic Disturbances and Genetics.

Ammonia↗
PubMed1985

[The horror story--a contribution of horror literature to psychoanalysis].

Using the example of the vampire motif origin and psychic function of the ghost-story in context of the pertaining historical situation are presented. A comparison to the development and function of night-mares is drawn.--The vampire motif in Europe originally developed at the end of the Middle Ages. As with the collective madness of witch persecution it was a superstition which was in fact supported by the church of this time. The belief in vampires was used for splitting of, projection and acting-out of taboo aggressive, oral and sexual drives. Although the era of Englightment quenched this superstition, the motif started to crop up in sublimated form: the vampire became a favourite motif in serious as in trivial literature of the 19th century. At first it can be seen as symbolic expression of rejected anxiety and guilt feelings of the bourgoisie after having thrown the absolutistic institution from power. In the course of the century the motif developed increasingly to an enciphered representation of sexuality perverted due to repression and rejection.--Our current social and literary life has now changed--also under the influence of Freuds work. The hypothesis is presented that meanwhile science fiction literature has become the successor of the ghost story, since it allows the preconscious presentation of contemporary anxiety and conflict and their rejection. Since fictions therefore can be viewed as a serious collective nightmare of the second half of the 20th century.

Arousal↗
PubMed1983

Light pulses entrain the circadian activity rhythm of a diurnal rodent (Ammospermophilus leucurus).

Circadian rhythms of wheel-running activity of the antelope ground squirrel (Ammospermophilus leucurus) were entrained by light-dark cycles (LD: 100 1x vs total darkness) with periods (T) between ca 23.75 and 24.75 hr. Two 1-hr light pulses per cycle ('skeleton photoperiods') with T = 24.25 hr as well as one 1-hr light pulse per cycle with Ts of 23.75 and 24.25 hr were effective in entraining the circadian activity rhythms in at least 50% of the antelope ground squirrels. Phase and period responses to single 1-hr light pulses were measured which depend on the initial phase and period of the rhythm. It is concluded that discrete (phasic) light input contributes to the mechanism of entrainment to LD cycles in diurnal rodents.

Activity Cycles↗
PubMed1979

[Psychoanalytic setting and technic as forms of interpersonal relations].

Psychoanalytic attitude, technique and setting are considered forms of real human interaction which the patient will internalize during the course of analysis. Using case material, some of the aspects of "classic" technique are compared to different forms of pathogenic interaction in the patients' families. It can be demonstrated that the same behavior on the part of the analyst can have quite different effects, depending on the interaction pattern internalized. Some aspects of technique may effect a new interactional experience or may be re-traumatizing or may be a joint acting out of a defense pattern. As the effect will mostly be due to the previous experience of the patient, not a general change, but flexibility in the use of technique is warranted. Such flexibility would also be apt to prevent "professional deformation" (Déformation professionelle) in the analyst.

Humans↗
PubMed1978

Phase relations between a circadian rhythm and its zeitgeber within the range of entrainment.

The regular day-night changes in tissues, physiologic functions, and behavior of organisms are based on endogenous rhythmic processes which under constant conditions continue with periods slightly deviating from 24 h. These 'circadian' rhythms have properties of self-sustained oscillators. Under natural conditions, circadian rhythms are synchronized (entrained) to 24 h by periodic factors in the environment, the so-called 'zeitgebers'. In the laboratory, circadian rhythms can also be entrained to periods other than 24 h within certain limits. Data on the phase relationship between the circadian rhythm and an entraining light-dark cycle for vertebrates, insects, plants, and unicellular organisms are reviewed.

Activity Cycles↗
PubMed1978

Comparative aspects of circadian rhythms in homeotherms, re-entrainment after phase shifts of the zeitgeber.

Re-entrainment of circadian activity of 3 avian species (Fringillidae: Fringilla coelebs, Carduelis chloris, Pyrrhula pyrrhula) and 4 mammalian species (Rodentia: Eutamias sibiricus, Funambulus pennanti, Glis glis, Mesocricetus auratus), subjected to 12:12 h light-dark (LD) cycles as zeitgeber, was studied after shifting the LD cycle by different amounts (hours) and in different directions (advances and delays). The properties of the zeitgeber were changed by varying light intensity during dark-time (ID) and/or light-time (IL). After 6 and 9-h advance and delay shifts of the LD cycle, the 3 species of finches similarly re-entrained their activity rhythms in the direction of the shifted zeitgeber. After 10.5 and 12-h shifts, the majority of individuals re-entrained by delay phase shifts of the rhythms. After two successive 6-h advance or delay shifts (resulting in inversion of the LD cycle) most finches responded by advances. Generally, the time needed for re-entrainment of 2/3 of the full shift (2/3 tr) in finches dependend on: (a) the direction of the phase shift ('asymmetry effect'), and (b) the phase-angle difference between onset of activity and light-on (psio) before the shift. After 12-h shifts, species-specific differences in the direction of re-entrainment and in the slope of the relationship between 2/3 tr and psio were found. In two rodents, the nocturnal golden hamster and the diurnal Siberian chipmunk, the direction of re-entrainment following inversion of the LD cycle depended on psio. In both species, 2/3 tr after inversion of the zeitgeber was significantly longer than in the common dormouse. In chipmunks, changes in 2/3 tr were correlated with changes in psio due to systematic variation of the zeitgeber properties (range and/or mean level). After 6-h phase shifts, the 'asymmetry effect' was opposite in the two nocturnal rodents, the hamster and the dormouse. It is suggested that the time course (direction and rate) of re-entrainment was influenced by differences in the characteristics of the circadian systems and their responses ('sensitivity') to light changes in the various species of birds and mammals.

Animals↗