Embryonic stem cells: a novel tool for the study of antiangiogenesis and tumor-induced angiogenesis

Major research initiatives in antiangiogenesis research have been undertaken to control angiogenic diseases such as polyarthritis, psoriasis, endometriosis, and diabetic retinopathy, and inhibition of tumor-induced angiogenesis has emerged as one of the most promising anti-cancer therapies currently available. Although several quantitative in vivo (i.e., animal models) as well as in vitro (i.e., pure endothelial cell cultures) angiogenesis assays have been described, the development of novel angiogenesis assays with organotypic culture systems that take into account oxygen and nutrient gradients, depth-dependent changes in intracellular pH and a redox state similar to that found in a natural tissue microenvironment are necessary to investigate blood vessel growth. Embryonic stem cells of mouse and human origin have the capacity to develop into three-dimensional tissues with functional capillaries, and this model system represents an excellent in vitro model for antiangiogenesis research. Upon confrontation of stem cells by co-culture with multicellular tumor spheroids, tumor-induced angiogenesis, i.e., the invasion of endothelial host-derived cells into a tumor tissue, can also be monitored. The current review provides an overview of embryonic stem cells as novel tools for antiangiogenesis research and outlines the use of confrontation cultures for the study of tumor-induced angiogenesis.

oscillations in a model of energy-dependent uptake by the endoplasmic reticulum

Active Ca2+ transport in living cells necessitates controlled supply of metabolic energy. Direct coupling between sarco/endoplasmic reticulum (ER) Ca2+ ATPases (SERCA) and intracellular energy-generation sites has been well established experimentally. On the basis of these experimental findings we propose a pump-driven model to investigate complex dynamic properties of a cell system. The model describes the pump process both by the Ca2+ ATPase itself and by a suitable description of the glycolysis. The associated set of differential equations shows a rich behavior, the solutions ranging from simple periodic oscillations to complex patterns such as bursting and spiking. Recent experimental results on calcium oscillations in Xenopus laevis oocytes and on dynamic patterns of intracellular Ca2+ concentrations in electrically non-excitable cells are well described by corresponding theoretical results derived within the proposed model. The simulation results are further compared to spontaneous [Ca2+] oscillations in primitive endodermal cells.

[Epidural haematoma in a newborn]

Birth injuries occur occasionally but, in contrast, perinatally acquired epidural and intracerebral hematomas as well as neonatal skull fractures are extremely rare. The appropriate diagnostic and therapeutic modalities depend on the size and site of the injury as well as any accompanying diseases. We report the case of a neonatal epidural and intracerebral haematoma with skull fracture following secondary caesarean section. There was no evidence for trauma during pregnancy, birth injury or other possible causes of bleeding. The haematoma was decompressed surgically. One year after surgery the boy suffers from moderate neurological compromise and focal seizures.

Loss of efferent vagal activity in acute schizophrenia

An increased heart rate has been reported in schizophrenia. It is unclear whether this is due to disease-related autonomic nervous system changes or a side effect of antipsychotic medication. Altered cardiac autonomic function might to some extent account for the elevated cardiovascular mortality rate of schizophrenic patients. We assessed heart rate variability (HRV) in 30 acute unmedicated schizophrenic patients and matched controls. Patients were re-investigated 2--4 days after initiation of treatment to assess effects of medication. Our study demonstrates that non-medicated schizophrenic patients were significantly different in heart rate (increase) and parasympathetic parameters (loss of efferent vagal activity) at rest and during deep respiration. No significant effect was found after initiation of neuroleptic therapy. We found a correlation between duration of disease and parasympathetic parameters as well as very low frequency power (VLF) and delusion (SAPS subscale). These data suggest that schizophrenia is accompanied by a loss of vagal efferent activity, probably due to disturbed cortical-subcortical circuits modulating the autonomic nervous system in acute psychosis. The definite mechanisms by which vagal activity might be suppressed in schizophrenia are unknown. Parasympathetic hypoactivity might increase the risk for sudden cardiac death and arrhythmias in this disease. Future studies are warranted to investigate the interaction between cardiac autonomic function and schizophrenia and to identify patients on risk.

Are we wasting our time with the sentinel technique? Fifteen reasons to stop axilla dissection

Originally, surgery for breast cancer involved removing the pectoral muscles and the regional lymph nodes. This drastic technique was based on Halsted's paradigm of continuous tumour spread via the lymph nodes. In the last century, the amount of surgery has gradually decreased as breast cancer has been recognised as a primary systemic, or partially systemic, disease. Nowadays, breast-conserving therapy is widely used, but axillary lymph node dissection (ALND) and the sentinel technique are still common. Can the patient also be spared such axillary surgery? We have assembled convincing arguments against ALND (and therefore also against the sentinel technique) based on the probability that positive lymph nodes are unlikely to metastasise and that removing them is redundant. At least a discussion of this topic is more than overdue, even if it may be too early to change behaviour.

Combined treatment of metastatic breast cancer (MBC) by high-dose chemotherapy (HDCT) and bispecific antibodies: a pilot study

This pilot study analyzed the efficacy and toxicity of high-dose chemotherapy (HDCT), autologous stem-cell transplantation (ASCT) and subsequent immunotherapy with T-cell reinfusion and trifunctional antibodies (trAbs) in chemotherapy-sensitive patients with metastatic breast cancer (MBC).

PATIENTS AND METHODS

After leukapheresis and cryopreservation of T-cells, patients received 2 cycles of induction chemotherapy ET (epirubicin/paclitaxel) and 1 cycle of El (epirubicin/ifosfamide), followed by G-CSF and stem-cell harvest. After a final cycle of ET, responders (CR/PR) underwent HDCT (thiotepa 600 mg/m2/melphalan 140-180 mg/m2) and ASCT. Once reconstitution was achieved, T-cells were reinfused, followed by application of trifunctional antibodies with specificities anti-EpCAM X anti-CD3 and anti-Her2/neu X anti-CD3.

RESULTS

Thirty-three patients were recruited into the study and 19, who had responded to initial chemotherapy, underwent HDCT and ASCT (4 CR, 15 PR, OR = 57.6%; 95% CI: 40-75%). Two early deaths were observed (1 toxic, 1 early progression). T-cell reinfusion and trAbs were given to 17 patients. TrAbs treatment resulted in intermittent fever, chills and elevated liver enzymes, which were seen in all patients. The median overall survival was 27.7 months (range: 5.9-82.6+). Patients who received 3 trAbs doses showed a trend towards an improved overall survival (47.2 vs. 22.4 months, p = 0.08 log rank).

CONCLUSION

This pilot study has shown the feasibility of combining HDCT with immunotherapy in MBC. Further investigation of this approach is indicated.

Impaired niacin sensitivity in acute first-episode but not in multi-episode schizophrenia

Niacin (vitamin B3) flushing--a marker of altered prostaglandin signaling--is indirectly linked to the phospholipid-prostaglandin metabolism. Diminished skin flushing was repeatedly found in schizophrenia, but has not been systematically investigated at different stages of disorder as yet. We compared niacin sensitivity of 32 first-episode and 32 multi-episode patients (mainly on stable medication) with age and gender matched healthy controls. Methylnicotinate was applied in three concentrations onto the inner forearm skin. Flush response was assessed in 3 min intervals over 15 min using optical reflection spectroscopy. Whereas first-episode patients showed significantly diminished flush response as compared to controls, comparable differences were not found between multi-episode patients and controls. Comparison of niacin sensitivity at different stages of schizophrenia support the notion of altered prostaglandin signaling primarily at the onset of disorder. Longitudinal studies have to rule out possible long-term effects of neuroleptic medication.

Schizophrenie als Diskonnektionssyndrom

Aside from characteristic psychopathological symptoms, cognitive deficits are a core feature of schizophrenia. These deficits can only be addressed within the context of widespread functional interactions among different brain areas. To examine these interactions, structural equation modeling (SEM) was used for the analysis of fMRI datasets. In a series of studies, both in antipsychotic-treated and drug-free schizophrenic patients, a pattern of enhanced thalamocortical functional connectivity could be observed as an indicator for possible disruptions of frontostriatal thalamocortical circuitry. Moreover, drug-free patients and those receiving typical antipsychotic drugs were characterized by reduced interhemispheric corticocortical connectivity. This difference relative to normal controls was less in patients under atypical antipsychotic drugs. The results could be interpreted as a beneficial effect of atypical antipsychotic drugs on information processing in schizophrenic patients. The present findings are consistent with the model of schizophrenia as a disconnection syndrome and earlier concepts of "cognitive dysmetria" in schizophrenia.

Identification and characterization of embryonic stem cell‐derived pacemaker and atrial cardiomyocytes

The aim of this study was to identify and functionally characterize cardiac subtypes during early stages of development. For this purpose, transgenic embryonic stem cells were generated using the alpha-myosin heavy chain promoter driving the expression of the enhanced green fluorescent protein (EGFP). EGFP-positive clusters of cells were first observed as early as 7 days of development, thus, even before the initiation of the contractile activity. Flow cytometry and single-cell fluorescence measurements evidenced large diversities of EGFP intensity. Patch-clamp experiments showed EGFP expression exclusively in pacemaker and atrial but not ventricular cells. The highest fluorescence intensities were detected in pacemaker-like cardiomyocytes. In accordance, multielectrode-array recordings of whole embryoid bodies confirmed that the pacemaker center coincided with strongly EGFP-positive areas. The cardiac subtypes displayed already at this early stage differential characteristics of electrical activity and ion channel expression. Thus, quantitation of the alpha-myosin heavy chain driven reporter gene expression allows identification and functional characterization of early cardiac subtypes.

Isolated diffuse hemangiomatosis of the spleen: case report and review of literature

Small localized hemangiomas are common neoplasms of the spleen. Isolated diffuse splenic hemangiomatosis, however, is very rare. This lesion can be accompanied by severe hypersplenism and other complications. We report on a case with significant splenomegaly caused by diffuse hemangiomatosis, which was an incidental finding without any clinical disorders. After splenectomy, the normal parenchyma was found to be widely replaced by multiple spongy nodules. Histologically, cavernous vessels were distributed throughout the whole organ, with endothelial cells expressing vimentin, factor VIII and CD 31, but not CD8. Splenic sinus lining cells exhibited a strongly positive reaction with CD8, which became faint and disrupted in highly dilated sinuses in the vicinity of cavernous vessels. In some areas, there seemed to be a gradual transition from cystically dilated splenic sinuses to cavernous vessels. The differential diagnosis must consider other splenic vascular tumors, such as littoral cell angioma, lymphangioma, peliosis of the spleen, and hamartoma. The pathogenesis of diffuse splenic hemangiomatosis is controversial, and a malformative or neoplastic origin is under debate. A derivation from splenic sinusoidal cells was suggested by some authors, but was rejected by others. Our findings cannot exclude a neoplastic origin from splenic sinuses but, finally, the etiology and pathogenesis of this vascular lesion remain uncertain.

Implication of therapeutic cloning for organ transplantation

Replacement of damaged myocardium with electrically functional, contracting syncytium with a balanced blood supply remains a key goal for the treatment of hearts damaged by coronary heart disease or other disorders. Stem cell therapy offers a potential solution. This paper describes the value of in vitro stem cell research to unravel the roles of key regulatory molecules in embryogenesis of myocardium and blood vessels. Studies have shown that functioning myocytes can be derived from stem cells in vitro and engrafted into infarcted areas of heart where they develop into functional adult like cardiomyocytes with action potentials and capacity for beta adrenergic and muscarinic regulation. Further studies have identified specific roles for platelet endothelial cell adhesion molecule (PECAM), vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF) in the sequential differentiation of blood vessels and capillaries.

[Mismatch negativity in schizophrenia research. An indicator of early processing disorders of acoustic information]

Mismatch negativity (MMN) represents an event-related component of the auditory evoked potentials at about 100-250 ms, evoked by discernible changes in an ongoing uniform acoustic stimulation. The current paper reviews all recently published MMN studies in the field of schizophrenia research. A reduced MMN in schizophrenic patients is found in the majority of the studies. This deficit is likely to be related to the disorder, since antipsychotic medication seems to have little influence on these results. Interestingly, a reduced MMN is also found in first-degree relatives of patients. Clear evidence for a hemispheric lateralization of the MMN reduction in schizophrenic patients is lacking. A hypofunction of the N-methyl-D-aspartate (NMDA) receptor is discussed as a possible explanation of this deficit.

[Additive treatment for central vestibular vertigo]

We have observed in our own practice that numerous patients with primary symptoms of vertigo exhibit cervical segmental muscular imbalance and increased tension in the masticatory musculature. This is frequently associated with functional blockades, especially in the joints of the head and upper cervical spine. Particularly important are special receptors of the small vertebral joints and muscle insertions at the cervicocranial transition. Evidence indicates that there are neuroanatomic structures between these receptors and the central vestibular and cochlear core area of the brain stem, which can explain the vertigo symptoms as well as the frequently associated tinnitus, headache or otalgia. Therapeutic approaches include interruption of the pathological reflex arcs so that muscle tension can resolve and imbalances are equalized. The nociceptive stimulus to the brain stem and its core centers thus recedes. Deafferentation follows from the reflex zones of the posterior oral cavity in the sense of oral acupuncture. Additional procedures include neural therapeutic injections at acupuncture points at the cervicocranial transition, the ear, and maxillary area as well as needle acupuncture of the head, ear, and hand. In isolated cases, improvement of the vertigo symptoms is noticed as early as after the first treatment session. Among other methods, spinovestibular tests according to Romberg and Unterberger can be employed to objectify treatment results.