Pax-1 in the development of the cervico-occipital transitional zone

The Pax-1 gene has been found to play an important role in the development of the vertebral column. The cervico-occipital transitional zone is a specialized region of the vertebral column, and malformations of this region have frequently been described in humans. The exact embryonic border between head and trunk is a matter of controversy. In order to determine a possible role of Pax-1 in the development of the cervico-occipital transitional zone we studied the expression of this gene in a series of quail embryos and murine fetuses with in situ hybridization and immunohistochemistry. Pax-1 is expressed in all somites of the embryo, including the first five occipital ones. During embryonic days 3–5 the gene is down-regulated in the caudal direction within the first five somites, whereas more caudally Pax-1 is strongly expressed in the cells of the perinotochordal tube. In 5-day-old quail embryos, the cartilaginous anlage of the basioccipital bone has developed and there is no more expression of Pax-1 in this region. The fusion of the dens axis with the body of the axis also coincides with switching off of the Pax-1 gene. More caudally, the gene is continuously expressed in the intervertebral discs of murine embryos and therefore seems to be important for the process of resegmentation. Quail embryos do not possess permanent intervertebral discs. Hyper- or hyposegmentation defects may be explained by an over- or under-expression of Pax-1 during development. We also reinvestigated the border between the head and trunk in chick embryos by performing homotopical grafting experiments of the 5^th somite between chick and quail embryos. Grafted quail cells formed mainly the caudal end of the basioccipital bone. They were also located in the cranial half of the ventral atlantic arch, and only a few cells were found in the tip of the dens axis.     

Advancing social work practice in end-of-life care

Insufficient training of health professionals has often been cited as a major barrier to improving the system of care for dying patients and for the bereaved. Although specific problems have been identified for physicians and nurses, the problems of social work in this substantive area have only recently been explored. This study used a practitioner survey, focus groups, and a survey of faculty of schools of social work to broaden the information base. Results suggested that not unlike the professions of medicine and nursing, social work knowledge and skill development in the care of the dying is uneven and not integrated sufficiently with theoretical concepts and research. Social workers felt unprepared for this work by their master's level training and unsupported by continuing education programs. They recognized few social work scholars who could function as role models by providing comprehensive training, knowledge building, innovation, and advocacy. A program for leadership development was created to test new approaches to professional development in the care of the dying and the bereaved.     

Modification of sexual behavior of Long-Evans male rats by drugs acting on the 5-HT1A receptor

Modulation of the sexual behavior of male rats by the anxiolytic buspirone (S-20499) and its analog gepirone were compared to the effects of 8-OH-DPAT (or DPAT, a selective 5-HT1A reference agonist), and BMY-7378 (a selective 5-HT1A partial agonist). Long-Evans rats were used; modulation of copulatory behavior and alteration of penile reflexes were examined. Modulation of copulatory behavior was assessed by three indices: frequency and length of intromission, and latency of ejaculation. DPAT, at doses of 1-8 mg/kg, reduced these three indices in a time dependent manner such that the effects peaked at 45 min and normalized at 90 min. The dose-effect relationship (assessed 45 min after DPAT injection) is bell-shaped with an ED50 approximately 1 mg/kg on the ascending limb of the curve. The effects of buspirone (2 mg/kg) and gepirone (2 mg/kg) on copulatory behavior were indistinguishable from control. BMY-7378 alone and in combination with these other 5-HT1A agonists reduced copulatory behavior, though not statistically significant. Penile reflexes, including number of erections, cups and flips, were inhibited by these agents: DPAT>buspirone>gepirone (inactive at 2 mg/kg). Furthermore, the latency period to erection was at least doubled by DPAT (2 mg/kg). Buspirone and gepirone, however, reduced the latency period to erection. BMY-7378 inhibited penile reflexes when administered alone and even more in combination with DPAT or buspirone. Two butyrophenone analogs, spiperone (a 5-HT1A and dopamine D2 antagonist) and haloperidol (a D2 antagonist), were also tested for their interaction with DPAT. Both of these drugs (at 0.25 mg/kg, 60 min after administration) reduced all indices of penile reflexes and copulation. Furthermore, in combination with DPAT (2 mg/kg, 45 min), the effects were synergistic such that sexual activity came nearly to a standstill. These opposing effects on putatively brain originated copulatory behavior and spinal mediated penile reflexes indicate that the effects of buspirone and DPAT on sexual behavior in the male rat may be possible at different parts of the central nervous system. If a tentative shared target site by DPAT and buspirone is the 5-HT1A receptor, than the same 5-HT receptor sub-type at different locations (brain, raphe nuclei, spinal cord and autonomic ganglia) may modulate rat sexual behavior in opposing ways.     

E5531, a synthetic non-toxic lipid A derivative blocks the immunobiological activities of lipopolysaccharide.

1. The major pathological responses to Gram-negative bacterial sepsis are triggered by endotoxin or lipopolysaccharide. As endotoxin is shed from the bacterial outer membrane, it induces immunological responses that lead to release of a variety of cytokines and other cellular mediators. As part of a program aimed at developing a therapeutic agent for septic shock, we have developed E5531, a novel synthetic lipopolysaccharide antagonist. 2. As measured by release by tumour necrosis factor-alpha, human monocytes or whole blood can be activated by lipopolysaccharide, lipid A, and lipoteichoic acid (from Gram-positive bacteria). E5531 potently antagonizes activation by all these agents while itself being devoid of agonistic activity. 3. The inhibitory activity of E5531 was dependent on time of addition. When 10 nM E5531 was added simultaneously with lipopolysaccharide or 1 - 3 h before addition of lipopolysaccharide, production of tumour necrosis factor-alpha was inhibited by more than 98%. The addition of E5531 1 h after lipopolysaccharide reduced the efficacy of E5531 by 47%. 4. Antagonistic activity of E5531 was specific for lipopolysaccharide as it was ineffective at inhibiting interferon-gamma mediated NO release of RAW 264.7 cells, phorbor 12-myristate 13-acetate stimulated superoxide anion production in human neutrophils, concanavalin A stimulated mitogenic activity in murine thymocytes and tumor necrosis factor-alpha induced E-selectin expression in human umbilical vein endothelial cells. 5. E5531 as well as MY4, an anti-CD14 antibody, inhibited radiolabelled lipopolysaccharide binding in human monocytes. 6. These results support our contention that E5531 is a potent antagonist of lipopolysaccharide-induced release of tumour necrosis factor-alpha and other cellular mediators and may be an effective therapeutic agent for human septic shock due to Gram-negative bacteria.     

Uptake of iodine-123-α-methyl tyrosine by gliomas and non-neoplastic brain lesions

Using single-photon emission tomography (SPET), the radiopharmaceuticall,-3-iodine-123--methyl tyrosine (IMT) has been applied to the imaging of amino acid transport into brain tumours. It was the aim of this study to investigate whether IMT SPET is capable of differentiating between high-grade gliomas, low-grade gliomas and non-neoplastic brain lesions. To this end, IMT uptake was determined in 53 patients using the triple-headed SPET camera MULTISPECT 3. Twenty-eight of these subjects suffered from high-grade gliomas (WHO grade III or IV), 12 from low-grade gliomas (WHO grade II), and 13 from non-neoplastic brain lesions, including lesions after effective therapy of a glioma (five cases), infarctions (four cases), inflammatory lesions (three cases) and traumatic haematoma (one case). IMT uptake was significantly higher in high-grade gliomas than in low-grade gliomas and non-neoplastic lesions. IMT uptake by low-grade gliomas was not significantly different from that by non-neoplastic lesions. Diagnostic sensitivity and specificity were 71% and 83% for differentiating high-grade from low-grade gliomas, 82% and 100% for distinguishing high-grade gliomas from non-neoplastic lesions, and 50% and 100% for discriminating low-grade gliomas from non-neoplastic lesions. Analogously to positron emission tomography with radioactively labelled amino acids and fluorine-18 deoxyglucose, IMT SPET may aid in differentiating high-grade gliomas from histologically benign brain tumours and non-neoplastic brain lesions; it is of only limited value in differentiating between non-neoplastic lesions and histologically benign brain tumours.     

Nutzen-Risiko-Abw?gung bei Antiinfektiva aus der Sicht der Zulassungsbeh?rde

Die Anforderungen zum Nachweis der Wirksamkeit von Antibiotika/Chemotherapeutika sind so hoch, daß der Nutzen eines neuen Wirkstoffes meistens sehr gut abgeschätzt werden kann. Im Zulassungsverfahren liegt das Schwergewicht bei der Nutzen-Schaden-Abschätzung eher auf der Seite der Risikoermittlung. Bei einem neuen Wirkstoff stützt sich die klinische Dokumentation in der Regel auf ca. 2 000–4 000, in seltenen Ausnahmefällen auf bis zu 9 000 auswertbare Patienten. Nebenwirkungen mit Inzidenzen < 0,5%=" können=" selbst=" bei=" so=" großen=" patientenzahlen=" nicht=" entdeckt=" werden.=" die=" beurteilung=" der=" risiken=" eines=" neuen=" antiinfektivums=" stützt=" sich=" auf=" erkenntnisse=" aus=" folgenden=" quellen:=" studien=" zur=" toxizität=" am=" tier,=" untersuchungen=" zur=" sicherheitspharmakologie=" (mensch=" und=" tier),=" klinische=" studien=" zur=" wirksamkeit=" und=" verträglichkeit,=" nebenwirkungsprofil=">fingerprint) bei Substanzen aus bekannten Stoffklassen, Erfahrungen aus anderen Ländern, Erfassung von unerwünschten Wirkungen nach Zulassung. Bei neuen Wirkstoffen aus bekannten chemischen Klassen sind viele unerwünschte Wirkungen auf Grund des fingerprints und bekannter Struktur-Nebenwirkungsbeziehungen vorhersagbar. Bei Substanzen, die zu keiner eingeführten Wirkstoffklasse gehören, besteht eine größere Unsicherheit. Gibt es anerkannte Alternativen, dann dürfen die möglichen Risiken auf keinen Fall höher sein als bei diesen. Wenn keine Alternativen verfügbar sind, können unter Umständen hohe Risiken akzeptiert werden. Zu den unerwünschten Wirkungen, die nicht vorhersehbar sind, zählen zum Beispiel Überempfindlichkeitsreaktionen, Okulotoxizität, ZNS-Reaktionen. Letztere sind bei Chinolonen, Mefloquin, Chloroquin, Trimethoprim, Ketoconazol, Aciclovir, Ganciclovir bekannt. Diese Wirkungen wurden manchmal erst viele Jahre nach Einführung beobachtet. Eine endgültige Nutzen-Schaden-Abschätzung ist daher erst mehrere Jahre nach der Zulassung möglich. Bei Bekanntwerden unerwarteter und schwerwiegender Risiken kann unter Umständen eine völlig neue Bewertung erforderlich werden (Stufenplanverfahren).The present standard requirements for the clinical evaluation of anti-infective drugs are so high that in most cases strong evidence for the benefit of a new medicine can be provided. Therefore risk estimation is much more emphasized than proof of efficacy during the review process performed by the regulatory authority. The total number of patients treated with an investigational drug before an application is made for a product licence varies between 2,000 and 4,000; in rare instances up to 9,000 patients are evaluable. It is obvious that adverse effects with incidences of 0.5% cannot be detected during clinical investigation, even with such a great number of patients. The risk estimation of a new anti-infective drug is based on results from the following sources: toxicity studies in animals, studies on general pharmacology (preclinical and clinical), clinical studies on safety and efficacy, finger-print of adverse reactions of new compounds belonging to approved chemical classes, experience in other countries, and monitoring of safety after licensing. As many drugs share chemical or pharmacological characteristics with approved drugs, the pattern of adverse effects can be anticipated. When reviewing a new anti-infective agent not belonging to an approved chemical class, there remains more uncertainty. In the case of infections for which current treatment exists, the possible risks which can be accepted for a new compound cannot be higher than that of the alternatives. If no alternatives exist, in certain cases high risks can be accepted, especially when a potentially life-saving or life-prolonging drug is being evaluated. Among the adverse effects which cannot be anticipated are: hypersensitivity, ocular toxicity and CNS reactions. In humans, quinolones, antimalarials such as mefloquine and chloroquine, trimethoprim, ketoconazole, aciclovir and ganciclovir can produce various CNS effects. In some cases (e. g. ketoconazole, chloroquine), these effects have been described for the first time only several years after marketing. Often, a final benefit risk assessment of a new drug can be made several years after marketing and broad clinical experience. When unanticipated and serious adverse effects become known with the use of a new anti-infective drug, a total new benefit-risk assessment may be necessary (Stufenplan-Verfahren, graduated plan in accordance with article 63 of the German Drug Law). This was true in 1983 for the NMTT-cephalosporins when bleeding caused by coagulation disturbances was detected.     

Morphologic dysplasia in de novo acute myeloid leukemia (AML) is related to unfavorable cytogenetics but has no independent prognostic relevance under the conditions of intensive induction therapy: results of a multiparameter analysis from the German AML Cooperative Group studies.

PURPOSE: On the basis of cytomorphology according to the French-American-British (FAB) classification, we evaluated the prognostic impact of dysplastic features and other parameters in de novo acute myeloid leukemia (AML). We also assessed the clinical significance of the recently introduced World Health Organization (WHO) classification for AML, which proposed dysplasia as a new parameter for classification. PATIENTS AND METHODS: We analyzed prospectively 614 patients with de novo AML, all of whom were diagnosed by central morphologic analysis and treated within the German AML Cooperative Group (AMLCG)-92 or the AMLCG-acute promyalocytic leukemia study. RESULTS: Patients with AML M3, M3v, or M4eo demonstrated a better outcome compared with all other FAB subtypes (P <.001); no prognostic difference was observed among other FAB subtypes. The presence or absence of dysplasia failed to demonstrate prognostic relevance. Other prognostic markers, such as age, cytogenetics, presence of Auer rods, and lactate dehydrogenase (LDH) level at diagnosis, all showed significant impact on overall and event-free survival in univariate analyses (P <.001 for all parameters tested). However, in a multivariate analysis, only cytogenetics (unfavorable or favorable), age, and high LDH maintained their prognostic impact. Dysplasia was not found to be an independent prognostic parameter, but the detection of trilineage dysplasia correlated with unfavorable cytogenetics. CONCLUSION: Our results indicate that cytomorphology and classification according to FAB criteria are still necessary for the diagnosis of AML but have no relevance for prognosis in addition to cytogenetics. Our results suggest that the WHO classification should be further developed by using cytogenetics as the main determinant of biology. Dysplastic features, in particular, have no additional impact on predicting prognosis when cytogenetics are taken into account.     

Online-Kurs Notfallmedizin Kurrikulare Integration von Computer-based Training

Emergency medicine is characterized by rapid decision making to help patients in life-threatening situations. Teaching these skills requires a high level of interaction between medical students and the lecturer. We designed, implemented, and evaluated a generic computer-based training (CBT) system to provide a more active way of learning emergency medicine. The content of the training program is adapted to the knowledge of third year medical students and is focused on basic skills and real-world problems. The teacher presents the case with authentic video sequences and slides. The cases are classified into four groups: heart (e.g., myocardial infarction), respiration (e.g., asthma bronchiale), trauma (e.g., car accident), and loss of consciousness (e.g., coma). Within a realistic time frame, the students have to answer free text and multiple choice questions on a work-station. All answers given by the students are processed anonymously by the CBT system via a central server and displayed on a large video screen, thus enabling a detailed discussion without intimidation of individual students. This interactive technique allows for immediate feedback from the lecturer based on the specific knowledge of his group and his own experience. The IT concept, which is scalable to many subjects, is based on state of the art internet technology and therefore suitable for teleteaching. A major design objective for the program was a self-explaining and robust user interface. The system has been in routine use since 1998. We designed an evaluation form consisting of 21 items focused on subjective rating of learning success, acceptance of CBT, and technical feasibility. We analyzed forms from 138 students and found high scores for acceptance and learning success (median 5 on a 6-point scale). user problems with the program were denied (median 1 on a 6-point scale). Computer-based training with Internet technology can provide a successful method for interactive teaching of emergency medicine and is well accepted by students.     

BCR-ABL-transduced human cord blood cells produce abnormal populations in immunodeficient mice.

In this study, we describe the successful use of a gene transfer approach to demonstrate the ability of forced BCR-ABL expression to deregulate the growth and differentiation of primitive naive human hematopoietic cells after their transplantation into immunodeficient mice. Human CD34+ cord blood cells were exposed to an MSCV retrovirus containing a BCR-ABL-IRES-GFP (P210) cassette and then injected immediately into sublethally irradiated nonobese diabetic-severe combined immunodeficiency (NOD/SCID) or NOD/SCID-beta2microglobulin-/- mice. P210- and control-transduced (GFP+) human hematopoietic cells were produced in the bone marrow of the mice at similar levels until termination of the experiments 5-6 months later. However, the P210-transduced cells produced a markedly different spectrum of progeny, with an increased ratio of myeloid to B-lymphoid cells and a frequently prolonged increase in erythroid and megakaryocytic cells. After 5 months, several of the mice transplanted with P210-transduced cells developed an increased WBC count and/or splenomegaly due to an expansion of the human GFP+ population. These findings demonstrate that forced expression of BCR-ABL in primitive transplantable human hematopoietic cells is sufficient to cause a rapid and persistent deregulation of their growth and differentiation in vivo with occasional evidence after several months of progression to an early stage of disease.     

Anti-inflammatory effects of fructose-1,6-bisphosphate on carrageenan-induced pleurisy in rat.

In the present study, we evaluated the effect of fructose-1,6-bisphosphate (FBP), a high energy intermediate metabolite of glycolysis, in an acute model of lung injury. Injection of carrageenan into the pleural cavity of rats elicited an acute inflammation response characterized by a fluid accumulation in the pleural cavity which contained a large number of polymorphonuclear neutrophils. FBP (500mg/kg) attenuated the inflammation parameters: exudate volume, total leukocytes and the number of polymorphonuclear leukocytes, but the protein concentration in the exudate was not significantly affected by treatment with FBP. The precise site and mechanism of the anti-inflammatory effect was not addressed, considering the diverse pharmacological actions of FBP. This drug has anti-inflammatory actions suggesting that it may represent a novel strategy for the modulation of inflammatory response.