[Detection of abnormalities in Magdeburg according to the Mainz model]. / Fehlbildungserfassung nach dem Mainzer Modell in Magdeburg.

Between 09/01/92 and 08/31/95 the Mainz model to register birth defects had been tested in the city of Magdeburg at the same time when the regional register instituted in 1980 was continued. The aim of this hospital-based model for the thorough registry of malformations in neonates is to examine all newborns born in hospitals using clinical and sonographical methods by experienced physicians according to a standardized scheme. Additional medical and social data were recorded. Data on live-and stillborn as well as spontaneous abortions older than the 16th gestational week and induced abortions following prenatal diagnosis were included. During the survey 5255 neonates were examined. The calculated percentage of major birth defects (by definition) was 7.8% and therefore higher than reported before. The experience with the Mainz model in the city of Magdeburg demonstrates, that this model is basically applicable to other centres. It is possible to obtain valid data on malformation frequencies in a defined population. Special attention has to be paid to certain conditions in the composition of hospital populations.

Regional cerebral glucose transport and utilization in Alzheimer's disease.

We performed dynamic positron emission tomographic (PET) studies of glucose utilization, using (18F) 2-fluoro-2-deoxy-D-glucose (FDG), in patients with probable Alzheimer's disease (AD) and healthy age-matched controls, to evaluate blood-brain-barrier glucose transport and glucose utilization rates in the disease. We found no significant differences in rate constants for glucose transport (k1 and k2) and phosphorylation (k3), nor for the vascular fraction (fv), between the 2 groups, although k3 and fv were relatively depressed in temporal cortex in AD. Absolute rates of glucose use were depressed in temporal and parietal cortex, and relative rCMRglc rates were lower in frontal, temporal, parietal, and occipital cortices. These data suggest that in AD bidirectional glucose transport is intact, and that temporal-parietal hypometabolism is present upon a background of widespread cortical metabolic impairment.

31P NMR spectroscopy of the in vivo metabolism of an intracerebral glioma in the rat.

The in vivo high-energy phosphorus metabolic profile and pH of an experimental intracerebral C6 glioma in rats was examined using surface coil 31P NMR spectroscopy. Initially, phosphorus-containing metabolites of the glioma were characterized by in vivo 31P surface coil spectroscopy of subcutaneously implanted tumors and by high-resolution NMR studies of perchloric acid (PCA) extracts of both freeze-clamped subcutaneous tumor tissue and cultured cells. These studies demonstrated that the C6 glioma has reduced levels of phosphocreatine (PCr) compared to the levels found in normal rat brain. Thus, reduced spectral PCr levels were useful as a metabolic indicator for monitoring the spatial selectivity of tumor metabolism distinct from that of adjacent normal brain tissue. To maximize 31P NMR signals from intracerebral tumors, tumor cells were stereotaxically placed superficially in the brain. Proton magnetic resonance imaging (1H MRI) was used to determine the size and location of the resultant brain tumors in order to preselect rats with large superficial tumors for spectroscopic study. 31P NMR spectra of the glioma tumors revealed a consistent reduction in the PCr/ATP ratio, an increase in the Pi/ATP ratio, and a slightly increased tissue pH. No correlation was found between levels of Pi/ATP and tumor pH in subcutaneous or intracerebral gliomas and the amount of necrosis as determined histologically. This study demonstrates that phosphorus metabolites of an experimental brain tumor in the rat can be monitored in vivo with minimal contributions from adjacent normal brain tissue metabolites using surface coil 31P NMR spectroscopy.

Carbohydrate metabolism of the rat C6 glioma. An in vivo 13C and in vitro 1H magnetic resonance spectroscopy study.

Surface coil 13C nuclear magnetic resonance (NMR) spectroscopy was used to investigate the in vivo carbohydrate metabolism of rat C6 gliomas during and after infusion with [1-13C] glucose. In vivo 1H-decoupled 13C NMR spectra of the glioma following infusion with [1-13C]glucose revealed the direct production of [3-13C]lactic acid, [1-13C]glycogen, and [4-13C], [3-13C], and [2-13C]glutamate/glutamine. Lactate levels of in vivo gliomas increased and reached steady state levels during [1-13C]glucose infusion, and decreased following termination of infusion. Complementary in vitro studies using supernatant media collected from C6 glioma cells incubated with media containing [1-13C] or [6-13C]glucose and glutamine were examined by 1H NMR spectroscopy. The [3-(13C/12C)]lactate ratios obtained from 1H spectra of supernatant media containing [1-13C]glucose revealed the percentage of glucose metabolized through the hexose monophosphate shunt to be 10.01 +/- 0.85% (n = 3), while similar measurements of media containing [6-13C]glucose and glutamine showed that glutaminolysis contributed 9.0 +/- 1.0% of total lactate production under these conditions. Enzymatic analysis of media determined lactate production to be 139 +/- 9 nmol per 10(6) cells per h (n = 4). These measurements demonstrate the ability of NMR to monitor brain tumor carbohydrate metabolism both in vitro and in vivo.

Methodologic factors affecting PET measurements of cerebral glucose metabolism.

Measurements of cerebral glucose utilization rates in similar populations of human subjects under similar conditions vary considerably because of methods used in data collection and analysis. Using data acquired in two patients, we evaluated the effects of time schedule of data collection, region of interest size, method of attenuation correction, and input function shape on LCMRglu determined by dynamic positron emission tomographic scanning and calculation of rate constants. These different strategies of data acquisition and analysis produced variations of 3 to 14% in calculated LCMRglu. These factors, in conjunction with the well described effects of instrument resolution and sensitivity may account for data discrepancies in the literature.

[Kidney sonography in glomerulopathies in childhood]. / Die Nierensonographie bei Glomerulopathien im Kindesalter.

The rapid progressive course of the glomerulonephritis shows an independent sonographic picture. Apart from the massive enlargement of the organ and the increase of the parenchyma-pyelo-index the kidneys show a high echogenicity, wavy marginal contours and unclear inner structures. In chronic glomerulonephritis both enlarged and diminished kidneys are to be found. A differentiation to the nephrotic syndrome is possible only with the help of the partly increased echogenicity. The elimination of the chronic glomerulopathies from the chronic pyelonephritis by means of sonography does not render any difficulties. In the Alport-syndrome the ultrasound diagnostic gives references to the activity or furidity of the disease. With the increase of the renal symptoms the sonographic picture of the kidneys also changes. In the sonogram no peculiarities for the Schönlein-Henoch nephritis and proteinuria are to be expected. For the acute and chronic glomerulonephritis as well as the Alport-syndrome the use of the sonography for the long-term control of the course is recommended.

Dynamic PET data analysis.

A general method for estimating the precision of parameters resulting from the use of various experimental designs (rate of injection and rate of tomographic data collection) in emission tomography studies is proposed. The sensitivity matrix of the study model and an estimate of the statistical uncertainty of the tomographic data are used to compute the covariance matrix of the parameters. The determinant of this covariance matrix (proportional to the total volume of uncertainty of the model parameters) serves as a criterion to be minimized. The method is applied to a three-compartment, three-transfer rate constant for glucose metabolism using dynamic positron emission tomography, and a comparison of various current protocols is made with simulated data. The results show that higher rates of injection and higher rates of tomographic data collection at early times lead to smaller statistical uncertainties for the estimates of rate constants. However, for the range of rate constants encountered in practice, differences are insignificant when an initial scan duration less than 30 s is used, without regarding the injection duration.

[Kidney sonography in childhood in chronic recurring pyelonephritis without a urinary transport disorder]. / Die Nierensonographie im Kindesalter bei chronisch rezidivierender Pyelonephritis ohne Harntransportstörung.

201 children with healthy kidneys and 61 patients of the paediatric nephrological dispensary with chronically relapsing pyelonephritis without disturbance of the transport of urine were examined sonographically. With the help of an atrophy score was controlled, whether the summation of unspecific parameters is in connection with the length of the kidney. A correlation of the introduced point system with the size of the kidney could be proved. The atrophy score represented shall facilitate the sonographic control of the course of non-obstructive parenchymatous renal diseases.

[Amylase and lipase as reference values for the differential diagnosis of chronic kidney failure and pancreatitis]. / Amylase und Lipase als differentialdiagnostische Bezugsgrösse bei chronischem Nierenversagen und Pankreatitis.

To differentiate between pancreatitis in patients with chronic renal insufficiency and uremic pancreopathy we investigated 23 patients with chronic renal insufficiency, 28 patients on hemodialysis before and after treatment and 13 patients after renal transplantation. As controls served 15 healthy people. The total amylase in serum is significantly elevated in patients with chronic renal insufficiency regardless if they were treated with hemodialysis or not. This elevation is due to an elevation of the pancreatic isoenzyme. The testing of both isoamylases (pancreatic and salivary) does not contribute to a better diagnosis. Patients with chronic renal insufficiency show a lower concentration of the amylases in their urine than their healthy controls. Lipase and creatinin show a linear correlation in serum. In the individual case it is not possible to draw a definite diagnostic conclusion using the above mentioned parameters because of the wide distribution of the measured values.

[The role of cardiac disease in the causation of cerebrovascular syndromes (author's transl)]. / Zur Frage der kardialen Verursachung von zerebrovaskulären Syndromen.

To obtain a clearer definition of the influence of cardiac disease on the development of cerebrovascular disease (CVD), we carried out a comparative study of two groups of patients, matched for age and sex, one with and one without CVD. These were compared with regard to the incidence of cardiac disease, hypertension and diabetes mellitus. On comparing the groups as a whole a significant preponderance of hypertension is shown in patients with CVD, but no significant difference in the frequency of cardiac disease. With regard to the site of the lesion in CVD there is a clear preponderance of cardiac arrhythmias when the territory of the carotid artery is affected. This seems to favour an embolic, rather than a haemodynamic mechanism in the aetiology of cardiogenic CVD. Hence, it follows for therapeutic purposes that in the case of arrhythmias, prophylaxis with aggregation-inhibiting drugs to prevent recurrence of embolism and adequate treatment of hypertension are useful measures, whereas administration of digitalis should be determined only by the presence of cardiac insufficiency.