Broca's region subserves imagery of motion: a combined cytoarchitectonic and fMRI study

Broca's region in the dominant cerebral hemisphere is known to mediate the production of language but also contributes to comprehension. Here, we report the differential participation of Broca's region in imagery of motion in humans. Healthy volunteers were studied with functional magnetic resonance imaging (fMRI) while they imagined movement trajectories following different instructions. Imagery of right-hand finger movements induced a cortical activation pattern including dorsal and ventral portions of the premotor cortex, frontal medial wall areas, and cortical areas lining the intraparietal sulcus in both cerebral hemispheres. Imagery of movement observation and of a moving target specifically activated the opercular portion of the inferior frontal cortex. A left-hemispheric dominance was found for egocentric movements and a right-hemispheric dominance for movement characteristics in space. To precisely localize these inferior frontal activations, the fMRI data were coregistered with cytoarchitectonic maps of Broca's areas 44 and 45 in a common reference space. It was found that the activation areas in the opercular portion of the inferior frontal cortex were localized to area 44 of Broca's region. These activations of area 44 can be interpreted to possibly demonstrate the location of the human analogue to the so-called mirror neurones found in inferior frontal cortex of nonhuman primates. We suggest that area 44 mediates higher-order forelimb movement control resembling the neuronal mechanisms subserving speech.     

Molekulare Formen des prostataspezifischen Antigens und des humanen Kallikreins 2 als mögliche Indikatoren in der Prostatakarzinomdiagnostik

Prostate-specific antigen (PSA) is the most useful marker in the early detection of prostate cancer and in the monitoring of patients with this diagnosis. Molecular forms of PSA and human kallikrein 2 (hK2) have been used to discriminate between benign prostatic hyperplasia and prostate cancer, as well as for the detection of prostate cancer within the gray zone of PSA. In this respect, a literature survey on the diagnostic validity of free PSA (fPSA) related to total PSA (tPSA), PSA bound to alpha 1-antichymotrypsin (ACT-PSA), and complexed PSA (cPSA) is given together with our own results. The ratio of fPSA/tPSA has been shown to improve both sensitivity and specificity of prostate cancer diagnosis based on tPSA measurements. The number of biopsies can be reduced in the total PSA range of 4-10 micrograms/l. Furthermore, carcinomas can be detected in patients with PSA values less than 4 micrograms/l. ACT-PSA or cPSA alone and the calculated derivatives are not superior in their discriminatory power compared with tPSA and the fPSA% value. The other molecular PSA forms and hK2 are still objects of research and their diagnostic significance needs to be evaluated in more extensive clinical trials.     

Accurate determination of cast weight for neonates with clubfoot

The purpose of this study was to determine changes in cast weight during the first 48 hours after application so that the true weight of a neonate can be estimated without the need for removing the cast. Five types of cast materials were compared. Cast weight measurements were obtained before and after application and at intervals during 48 hours. Final cast weight averaged 107.5% of dry weight for plaster and 99% of dry weight for synthetic cast materials. For very low birth weight infants, the difference between the initial wet weight of plaster of Paris and its final dry weight may be significant for calculating drug and fluid dosages. The weight of an infant can now be calculated without the necessity of cast removal.     

Detection and clinical implications of early systemic tumor cell dissemination in breast cancer.

Blood-borne distant metastasis is the leading cause of cancer-related death in breast cancer. The onset of this fundamental process can now be assessed in cancer patients using ultrasensitive immunocytochemical and molecular assays able to detect even single metastatic cells. Analyses of bone marrow (BM) samples show that disseminated cells are present in 20-40% of primary breast cancer patients without any clinical or histopathological signs of metastasis. The common homing of circulating breast cancer cells in BM is indicative for systemic tumor cell spread and predictive for growth of overt metastases in relevant organ sites such as bone, lung, or liver. Recent clinical studies involving more than 3000 breast cancer patients demonstrated that the presence of tumor cells in BM at primary diagnosis is an independent prognostic factor for unfavorable clinical outcome. To date, sampling of BM, however, is not a routine procedure in clinical management of breast cancer patients. Therefore, several research groups have developed sensitive assays for detection of circulating tumor cells in peripheral blood. Studies evaluating the clinical relevance of these blood assays are ongoing. Here, we will review the existing tumor cell assays and discuss their current clinical relevance and perspectives for the clinical management of breast cancer patients.     

A Clinical and Histologic Comparison of Percutaneous Dilational Versus Conventional Surgical Tracheostomy

To directly compare percutaneous dilational tracheostomy (PDT) with conventional surgical tracheostomy, a prospective study was performed in 83 patients requiring tracheostomy for prolonged mechanical ventilation in the intensive care unit or after surgery for a large tumor in the upper respirodigestive tract. Median follow-up was 355 days after PDT and 338 days after conventional tracheostomy. The overall morbidity rate was significantly lower with PDT than with conventional tracheostomy (6.4% vs 36.1%; P < 0.001). Compared with conventional tracheostomy, PDT was also associated with a significantly lower incidence of postoperative bleeding (2.1% vs 13.9%; P < 0.05) and postoperative wound infection (0% vs 22.2%; P < 0.001). There were no clinical signs of laryngotracheal stenosis in either group. In conclusion, PDT is a simple, fast, safe bedside procedure that is associated with significantly lower morbidity than standard surgical tracheostomy.     

Reverse mutations – spontaneous amelioration or cure of inherited disorders?

Some recent publications indicate that inherited disorders can ameliorate or possibly disappear if mutations responsible for the disease revert to normal. This review tries to summarize our current knowledge about reverse mutations as this information may be of special interest for attempts at somatic gene therapy. Received: 14 July 1997 / Accepted: 2 March 1998     

Neural response to emotional salience in schizophrenia.

Neuroimaging probes of brain regions implicated in emotion represent an important research strategy for understanding emotional dysfunction in schizophrenia. Anterior limbic structures, such as the ventral striatum and the amygdala, have been implicated in the pathophysiology of schizophrenia and the generation of emotional responses, although few studies to date have used emotion probes to target these areas in schizophrenia. With this goal in mind, emotionally salient visual images were used in a simple, nondemanding task. In all, 13 medicated, schizophrenic patients, five unmedicated patients, and 10 healthy volunteers viewed complex visual pictures and a nonsalient, blank screen while regional cerebral blood flow was measured with the [O-15] water technique. Pictures consisted of real world scenes with aversive, positive, and nonaversive content. Eye movements were recorded simultaneous with scan acquisition. Positron emission tomography images were analyzed for baseline, tonic activity, in addition to phasic changes ('activation') to salient stimuli. Lateral eye movement measures and on-line ratings showed good behavioral compliance with the task. Patients with schizophrenia showed impaired neural responses to salient stimuli in the right ventral striatum (VS), and they exhibited elevated tonic activity levels in the right VS and bilateral amygdala, inversely correlated with overall symptom severity. The patients also showed reduced modulation of visual cortex by salient stimuli. The results show that patients with schizophrenia exhibit impaired neural responses to emotionally salient stimuli in the VS, supporting a role for this structure in the pathophysiology of the illness. Reduced modulation of visual cortex by emotionally salient stimuli also suggests a failure to organize cerebral activity at a global level.