Search PubMed⌕ Search

Biomedical subjects

P Hoff

Publications and source records attributed to P Hoff.

At least 55 records · Page 3Linked to original sources
PubMed1996

Mood (affective) disorders (F3). Results from the ICD-10 field trial of the Diagnostic Criteria for Research in German-speaking countries.

The present study reports results of the ICD-10 research criteria trial concerning the diagnosis of affective disorders (section F3). On the basis of written case reports and videotapes a total of 451 clinicians from 34 centres in German-speaking countries prepared 2.228 diagnostic ratings on 39 different psychiatric patients. Three of the 39 cases met the diagnostic criteria for affective disorders, and 248 of the diagnostic assessments referred to these cases. The majority of clinicians rated the reliability, the ease and the suitability of the diagnostic criteria positively. The reliability of the affective disorders was extremely good, with a kappa of 0.93 in the range of 2-character diagnoses. The reliability of the 3-character categories was much smaller: Kappa values for depressive episode (F31) and recurrent depressive disorder (F33) were 0.68 and 0.54, respectively. The lowest concordance had a kappa value of 0.22 and was found in the case report of dysthymia (F34.1). Therefore a more precise definition of the diagnostic criteria for dysthymia would be desirable.

Germany↗
PubMed1995

Alpha-particle radiotherapy with 211At-labeled monodisperse polymer particles, 211At-labeled IgG proteins, and free 211At in a murine intraperitoneal tumor model.

Four different chemical forms of the alpha-particle emitting radionuclide 211At were injected intraperitoneally in mice inoculated intraperitoneally 30 hr in advance with 10(6) cells of the K13 murine hybridoma cell line. The different 211At forms were (a) free 211At, (b) 211At-labeled TP-3 nonspecific monoclonal antibody (211At-TP-3), (c) 211At-labeled human IgG kappa (211At-hIgG kappa), and (d) 211At-labeled monodisperse polymer particles (211At-MDPP). A significantly prolonged survival (P < 0.05) was observed with injected doses down to 7 kBq for the 211At-MDPP, and down to 25 kBq for 211At-hIgG kappa. There were no significant differences in survival between 211At-MDPP, 211At-hIgG kappa, and 211At-TP-3 at the dose level of 200 kBq. The group receiving 250 kBq free 211At per animal had a shorter survival than the three other forms at 200 kBq. The groups treated with 500, 200, and 65 kBq 211At-MDPP had a similar survival. The group given the highest dose of 211At-hIgG kappa (275 kBq) had the highest fraction (50%) of long-term survivors of all groups. Biodistribution measurements and total body scintigrams in mice without tumor revealed that the free 211At was distributed all over the body within 10 min after injection while at 2 hr a high fraction of the 211At-TP-3 and 211At-hIgG kappa was still present intraperitoneally. In conclusion this study indicates that 211At-labeled MDPP and 211At-labeled IgG's may be efficient tools for treatment of intraperitoneal superficial tumor cells and malignant ascites.

Animals↗
PubMed1995

Ion channel involvement in anoxic depolarization induced by cardiac arrest in rat brain.

Anoxic depolarization (AD) and failure of ion homeostasis play an important role in ischemia-induced neuronal injury. In the present study, different drugs with known ion-channel-modulating properties were examined for their ability to interfere with cardiac-arrest-elicited AD and with the changes in the extracellular ion activity in rat brain. Our results indicate that only drugs primarily blocking membrane Na+ permeability (NBQX, R56865, and flunarizine) delayed the occurrence of AD, while compounds affecting cellular Ca2+ load (MK-801 and nimodipine) did not influence the latency time. The ischemia-induced [Na+]e reduction was attenuated by R56865. Blockade of the ATP-sensitive K+ channels with glibenclamide reduced the [K+]e increase upon ischemia, indicating an involvement of the KATP channels in ischemia-induced K+ efflux. The KATP channel opener cromakalim did not affect the AD or the [K+]e concentration. The ischemia-induced rapid decline of extracellular calcium was attenuated by receptor-operated Ca2+ channel blockers MK-801 and NBQX, but not by the voltage-operated Ca2+ channel blocker nimodipine, R56865, and flunarizine.

Adenosine Triphosphate↗
PubMed1995

[Subject and object of psychiatric research. On the history of concepts of a controversy].

The relationship between subject and object is one of the philosophical questions that are of direct relevance for understanding psychiatry as a clinical and scientific field. Characteristic examples from the history of psychiatry are analyzed, including the "romantic era", the clinical concepts in Germany at the turn of the century, and twentieth century theories associated with the linguistic turn in philosophy. The practical implications of these theoretical considerations are often underestimated; this is clarified by a critical look at operationalized diagnostic criteria in psychiatry and at one of the most influential modern epistemological theories, "Evolutionary epistemology."

Biological Psychiatry↗
PubMed1994

Analysis of the therapeutic gain in the treatment of human osteosarcoma microcolonies in vitro with 211At-labelled monoclonal antibody.

Microcolonies were obtained by culturing cells of two human osteosarcoma lines (OHS and KPDX) and one human melanoma line (WIX-c) for either 24 or 72 h. The microcolonies were treated with either alpha-particle radiation emitted by the 211At-labelled monoclonal antibody (MAb) TP-3 or external beam X-rays. Survival of microcolonies was assayed by colony formation. Therapeutic gain factor (TGF) values were calculated for two survival levels, 50% and 20% microcolony regeneration (i.e. at least one cell in 50% or 20% of the colonies survived the treatments). The TGF values were affected by the specific activity of the 211At-MAb conjugate, the antigen expression of the cells and the size and growth pattern of the microcolonies. Treatment with 211At-TP-3 gave TGF values that varied from 1.3 +/- 0.4 to 4.5 +/- 0.7 (mean +/- s.e.). The antigen-rich OHS cell line had on average 1.6 times higher TGF than the antigen-poor KPDX cell line. The TGF increased significantly with colony size for the densely packed colonies of the KPDX cell line but not for the OHS cell line, which had colonies with cells growing in a more scattered pattern. Control experiments with the two non-specific 211At forms, free 211At and 211At-labelled bovine serum albumin, gave TGF values from 0.6 +/- 0.1 to 1.0 +/- 0.3. This study suggests that in vivo evaluation of 211At-MAbs using relevant tumour models is desirable.

Antibodies, Monoclonal↗
PubMed1994

[Psychiatric diagnosis: Emil Kraepelin and ICD-10].

Kraepelin's main intention was to establish psychiatry as an independent, medically and scientifically oriented specialty. He tried to apply Wilhelm Wundt's complex theoretical system on psychiatric research, thereby simplifying, but not falsifying it. He regarded different kinds of mental illness as natural entities. According to his central hypothesis, all scientific methods will sooner or later arrive at these entities. The new operationalized diagnostic systems like ICD-10 and DSM-III-R stem from logical empiricism: Theoretical assumptions, especially with regard to pathogenesis and etiology, should not influence the diagnostic process. Contrary to Kraepelin, no implicit decision should be made on the fundamental nosological questions (i.e. strictly separated natural disease entities vs. blurred borders or categorical vs. dimensional approach. This comparison shows that Kraepelin, although not too much interested in epistemological issues, can be regarded a convincing example for the necessity to include them in the discussion of psychiatric research.

Germany↗
PubMed1994

Inactivation of human osteosarcoma cells in vitro by 211At-TP-3 monoclonal antibody: comparison with astatine-211-labeled bovine serum albumin, free astatine-211 and external-beam X rays.

The potential usefulness of alpha-particle radioimmunotherapy in the treatment of osteosarcoma was studied in vitro by using the monoclonal antibody TP-3 and cells of three human osteosarcoma cell lines (OHS, SAOS and KPDX) differing in antigen expression. Cell survival curves were established after treatment with (a) 211At-TP-3 of different specific activities, (b) 211At-labeled bovine serum albumin (BSA), (c) free 211At and (d) external-beam X rays. The three osteosarcoma cell lines showed similar survival curves, whether treated with external-beam X rays, 211At-BSA or free 211At. The D0's were lower for free 211At than for 211At-BSA. The survival curves for 211At-TP-3 treatment, on the other hand, differed significantly among the cell lines, suggesting that sensitivity to 211At-TP-3 treatment was governed by cellular properties other than sensitivity to external-beam X rays. The cellular property most important for sensitivity to 211At-TP-3 treatment was the antigen expression. Cell inactivation after 211At-TP-3 treatment increased substantially with increasing specific activity of the 211At-TP-3. At high specific activities, the cytotoxic effect of 211At-TP-3 was significantly higher than that of 211At-BSA. In conclusion, 211At-TP-3 has the potential to give clinically favorable therapeutic ratios in the treatment of osteosarcoma.

Antibodies, Monoclonal↗
PubMed1992

Distribution of intraperitoneally injected microspheres labeled with the alpha-emitter astatine (211At) compared with phosphorus (32P) and yttrium (90Y) colloids in mice.

The alpha-emitter 211At was bound to polymer microspheres with a diameter of 1.8 microns. The distributions in mice of intraperitoneally injected 211At microspheres, 90Y silicate colloid, and 32P chromic phosphate colloid were compared. The microspheres with 211At spread rapidly in the peritoneal cavity and remained mainly on the intraperitoneal surfaces. Intraperitoneal injection of 90Y colloid resulted in high levels in intraperitoneal fat and the diaphragm, but 1 day after injection 8.5% of the injected dose per gram was found in blood and after 6 days 2.5% was observed in bone. The highest accumulation of 32P was found in liver and spleen. The injection of additional nonradioactive chromic phosphate colloid resulted in an even higher accumulation of 32P in spleen and liver. The same phenomenon was not observed with 211At microspheres. It is suggested that it is not only the particle size which is important in the distribution of intraperitoneally injected colloid, but the amount of colloid, the type of colloid, the addition or presence of other substances such as ascites, and the animal species might also influence the distribution. In conclusion, the intraperitoneal distribution of 211At-labeled microspheres in mice was favorable compared with 90Y and 32P colloid. These data must be viewed cautiously since the distribution might be different in other animal species or humans.

Animals↗
PubMed1992

[Recent psychiatric classification systems and their significance for forensic psychiatry].

The influence of operationalized diagnostic systems is growing steadily in general and forensic psychiatry. This article discusses the historical context and the advantages and problems that may occur in the application of the new diagnostic systems. It is of special importance that the improvement of communication and reliability within psychiatry does not lead to an uncritical or even dogmatical understanding of the new diagnostic categories.

Diagnosis, Differential↗
PubMed1990

[Psychotic illness during treatment with clomifen].

Psychotic illness recurred in a 25-year-old manic-depressive woman during anti-infertility treatment with clomiphene citrate. The symptoms of this episode (disturbance of consciousness, psychomotoric abnormalities, paranoid-hallucinatory syndrome with transient neurological dysfunctions) differed significantly from previous and subsequent psychotic patterns. No organic cause other than treatment with clomiphene could be discovered despite intensive diagnostic efforts. The pathogenetic role of clomiphene is supported by comparable findings in certain post-partum psychoses. Women with a history of psychiatric disorders are especially at risk.

Acute Disease↗
PubMed1989

Repolarization interactions between cardiac segments of varying action potential duration.

We studied interactions between action potential duration (APD) disperse zones using a double compartment bath in which an APD lengthening solution (Ni++ 2 mmol/L, in Tyrode's solution) was added to one compartment (which contained a portion of the fiber labeled "segment A") followed by addition of an APD shortening solution (6 to 10 mmol/K+) to the other compartment ("segment B"). Standard microelectrode techniques were used in canine Purkinje fibers. With Ni++ in segment A, there was a dispersion in APD measured at both 50% (APD50) and 95% (APD95) of repolarization. After selective addition of K+ to segment B, APD50 dispersion remained constant while APD95 dispersion increased, which indicated a change in the slope of repolarization, a factor with possible arrhythmogenic potential. In addition, a characteristic transitional action potential was seen adjacent to the partition. This had a timely and normally sloping early repolarization followed by a much more gradually sloping shelf. Premature action potentials arising during this shelf had diminished upstrokes. Results of these experiments may be useful in evaluating APD dispersion in relation to arrhythmias.

Action Potentials↗
PubMed1988

Combined MAO-inhibitor and tri- (tetra) cyclic antidepressant treatment in therapy resistant depression.

1. One aspect of using MAO-inhibitors - combining them with tricyclic antidepressants in the treatment of therapy resistant depression - has always been controversely discussed in regard to its unusual toxicity and efficacy. 2. To obtain detailled information about safety and efficacy of such a combined treatment, the charts of 94 inpatients treated with a tranylcypromine - tri- (tetra) cyclic antidepressant combination were reviewed. 3. Within a mean treatment period of 21.9 days, 68% of the patients demonstrated a very good or good improvement to combined treatment, the most effective combination being tranylcypromine + amitriptyline. 4. The incidence of side effects among the patients on the combined regimen was slightly, but not significantly lower as compared to the patients on single tri- (tetra) cyclic antidepressant treatment. 5. Our retrospective study supports the general safety and efficacy of combined MAOI-TCA treatment and suggests that combined treatment, if properly administered, leads to neither serious complications nor an inordinate number of side effects.

Antidepressive Agents↗
PubMed1988

[Kraepelin's basic nosologic postulates. An attempt at a critical evaluation of the later works of Kraepelin].

This study discusses three important papers by Emil Kraepelin, published between 1918 and 1920. Kraepelin supports--in accordance with his teacher Wilhelm Wundt--the view of psychophysical parallelism as a basic principle of dealing with the questions of mental illness. Kraepelin is often called a nosologist; but one must not forget that Kraepelins nosology was not a static one, nor did he vote in favor of any kind of dogmatism. Only when Kraepelin's basic positions are reflected in a differentiated way, his enormous influence on very different parts of psychiatry as science can be understood.

Germany↗