Bispidine Chelators for Radiopharmaceutical Applications with Lanthanide, Actinide, and Main Group Metal Ions

Octadentate and specifically nonadentate ligands with a bispidine scaffold (3,7-diazabicyclo[3.3.1]nonane) are known to be efficiently coordinated to a range of metal ions of interest in radiopharmaceutical chemistry and lead to exceedingly stable and inert complexes. Nonadentate bispidine L2 (with a tridentate bipyridine acetate appended to N3 and a picolinate at N7) has been shown before to be an ideal chelator for 111In3+, 177Lu3+, and 225Ac3+, nuclides of interest for diagnosis and therapy, and a proof-of-principle study with an SSTR2-specific octreotate has shown potential for theranostic applications. We now have extended these studies in two directions. First, we present ligand derivative L3, in which the bipyridine acetate is substituted with terpyridine, a softer donor for metal ions with a preference for more covalency. L3 did not fulfill the hopes because complexation is much less efficient. While for Bi3+ and Pb2+ the ligand is an excellent chelator with properties similar to those of L2, Lu3+ and La3+ show very slow and inefficient complexation with L3 in contrast to L2, and 225Ac3+ is not fully coordinated, even at an increased temperature (92% radiochemical yield at 80 °C, 60 min, [L3] = 10-4 M). These observations have led to a hypothesis for the complexation pathway that is in line with all of the experimental data and supported by a preliminary density functional theory analysis, which is important for the design of further optimized bispidine chelators. Second, the coordination chemistry of L2 has been extended to Bi3+, La3+, and Pb2+, including solid state and solution structural work, complex stabilities, radiolabeling, and radiostability studies. All complexes of this ligand (La3+, Ac3+, Lu3+, Bi3+, In3+, and Pb2+), including nuclides for targeted α therapy (TAT), single-photon emission computed tomography, and positron emission tomography, are formed efficiently under physiological conditions, i.e., suitable for the labeling of delicate biological vectors such as antibodies, and the complexes are very stable and inert. Importantly, for TAT with 225Ac, the daughter nuclides 213Bi and 209Pb also form stable complexes, and this is important for reducing damage to healthy tissue.

No Evidence That RFamide-Related Peptide 3 Directly Modulates LH Secretion in the Ewe

The neuropeptide RFamide-related peptide 3 (RFRP-3) has been implicated in the control of gonadotropin secretion in both birds and mammals. However, in mammals, depending on species, sex and photoperiod, inhibitory, excitatory, or no effect of RFRP-3 on the plasma concentration of LH has been reported. In the ewe, treatment with RFRP-3 either reduced LH concentration or had no effect, and treatment with an RFRP-3 receptor antagonist (ie, RF9) resulted in increased concentration of plasma LH. To clarify these conflicting results in the present study, a set of experiments was performed in ewes. Multiple iv injections of RFRP-3 (6 × 50 μg) in ovariectomized ewes had no effect on plasma LH pulsatility. In intact ewes a bolus injection (500 μg) or an injection (250, 500, or 1000 μg) followed by a 4-hour perfusion (250, 500, or 1000 μg · h(-1)) of RFRP-3 had no effect on the LH pulse induced by kisspeptin (6.5 μg). In ovariectomized, estrogen-replaced ewes, the LH surge induced by estradiol benzoate was not modified by a 24-hour perfusion of RFRP-3 (500 μg h(-1)). Finally, although treatment with RF9 induced a robust release of LH, treatment with a more selective RFRP-3 receptor antagonist, GJ14, resulted in no evident increase of LH. In contrast to the inhibitory effect previously suggested, our data are more consistent with the concept that RFRP-3 has no direct effect on LH secretion in ewes and that RF9 effect on LH release is likely not RFRP-3 receptor mediated. Hence, RFRP-3 probably has a minor role on the control of LH secretion in the ewe.

The effect of discrimination training on responses to a new stimulus

Most previous research on the effect of the duration of preceding discrimination training on responding to a new stimulus has measured the responding during extinction. To reduce effects originating in the extinction procedure itself, the present study assessed the effect of discrimination training on responses to a new negative stimulus added during continued discrimination training. Pigeons were given a new negative stimulus (blue key) after 0, 1, 3, or 9 days of discrimination training with a yellow key as the positive stimulus, and both a green key and a red key as negative. Fewer responses were made to the blue key when it was introduced after nine days of discrimination training than after less discrimination training. That effect of long discrimination training agrees with reported results from extinction tests. However, the effect of briefer discrimination training in the present study differed from reported results with extinction testing. It appears that testing during continued discrimination training eliminates a distortion present in extinction tests of the effect of discrimination training on responding to a new stimulus.

Behavior changes during repeated eight-day extinctions

Pigeons were given repeated two-day conditionings alternating with eight-day extinctions using a trial procedure. One group had different key colors during each of the first five conditioning-extinction pairs; another group had the same key color throughout. Total extinction responses of both groups were quite constant over successive extinctions. This finding differs from the rapid declines found in most previous studies with bar-press and key-peck responses. The difference probably was due to our longer extinctions, because responses early in each extinction did decrease. However, that decrease was neutralized by increases in responses late in each extinction. The two opposite changes indicate the influence of two different factors during repeated extinctions, with neither factor having much stimulus specificity. The reduction of early responses may result from feeding changes confounded with extinction. The increase in later extinction responses may result from a decrease in the effect of unreinforced responses after their repeated occurrence.

Postoperative development of aspirin resistance following coronary artery bypass

BACKGROUND

Aspirin therapy is known to substantially reduce mortality and the rate of ischaemic complications after coronary artery bypass grafting (CABG). Rates of perioperative aspirin resistance cited in the literature are up to 50% and could be influenced by extracorporeal circulation. Thus, aspirin resistance after CABG may have a significant clinical relevance.

MATERIALS AND METHODS

In 59 patients undergoing CABG (on-pump, off-pump and combined procedures) aspirin resistance was investigated by arachidonic acid induced platelet aggregometry. Clinical relevance was assessed with 12-month follow up.

RESULTS

Two types of resistance were observed: A preoperative resistance (despite oral aspirin or in vitro addition) was present in 29% and a postoperative developing type was seen in 49% resulting in only 22% of patients with a 'normal' reaction to aspirin. If patients were already on oral aspirin at admission, the rate of resistance was significantly reduced. Off-pump surgery or pump-times exceeding 120 min had no significant impact on resistance. During the 12-month follow up (98.3%), there were three deaths (one stroke, one intestinal ischaemia, one mediastinitis after postoperative delirium) in patients with the perioperative resistance and none in other patients (P = 0.345). In none of those patients who presented with perioperative aspirin resistance, could this aspirin resistance be demonstrated when tested again after 12 months?

CONCLUSIONS

Aspirin resistance is a transient phenomenon present in the majority of patients undergoing CABG. The three deaths in the resistant group may - although not statistically significant - indicate the possibility of a worse outcome for patients with aspirin resistance.

Relationships among salinity, egg size, embryonic development, and larval biomass in the estuarine crab Chasmagnathus granulata Dana, 1851

We studied interrelationships between initial egg size and biomass, duration of embryogenesis at different salinities, and initial larval biomass in an estuarine crab, Chasmagnathus granulata. Ovigerous females were maintained at three different salinities (15 per thousand, 20 per thousand and 32 per thousand); initial egg size (mean diameter), biomass (dry weight, carbon and nitrogen) as well as changes in egg size, embryonic development duration, and initial larval biomass were measured.Initial egg size varied significantly among broods from different females maintained under identical environmental conditions. Eggs from females maintained at 15 per thousand had on average higher biomass and larger diameter. We hypothesise that this is a plastic response to salinity, which may have an adaptive value, i.e. it may increase the survivorship during postembryonic development. The degree of change in egg diameter during the embryonic development depended on salinity: eggs in a late developmental stage were at 15 per thousand significantly larger and had smaller increment than those incubated at higher salinities. Development duration was longer at 15 per thousand, but this was significant only for the intermediate embryonic stages. Initial larval biomass depended on initial egg size and on biomass loss during embryogenesis. Larvae with high initial biomass originated either from those eggs that had, already from egg laying, a high initial biomass (reflecting individual variability under identical conditions), or from those developing at a high salinity (32 per thousand), where embryonic biomass losses were generally minimum. Our results show that both individual variability in the provisioning of eggs with yolk and the salinity prevailing during the embryonic development are important factors causing variability in the initial larval biomass of C. granulata, and thus, in early larval survival and growth.

Ontogeny of osmoregulation and salinity tolerance in a mangrove crab, Sesarma curacaoense (Decapoda: Grapsidae)

The grapsid crab Sesarma curacaoense is believed to represent the closest saltwater relative to the ancestor which gave rise to an adaptive radiation of endemic freshwater and terrestrial species on the island of Jamaica. Living in mangrove swamps with variable salinity conditions and showing semiterrestrial behaviour, S. curacaoense exhibits ecological adaptations to non-marine conditions. In laboratory experiments, we studied the salinity tolerance during development from hatching to the end of the first juvenile stage. Successful development through metamorphosis occurred in the full salinity range tested (15-32 per thousand), although mortality was significantly enhanced and development delayed at 15 per thousand. In another series of experiments, we studied the ontogeny of the capability for osmoregulation, which is considered as the physiological basis of osmotic stress tolerance. Our results show that S. curacaoense is from hatching a fairly strong hyperosmoregulator in dilute media. This capability increased gradually from hatching throughout the larval and juvenile development. In seawater (32 per thousand) and at an enhanced salt concentration (44 per thousand), the zoeal stages remained hyperosmoconformers. The capability for hypoosmoregulation in concentrated media appeared first in the megalopa stage and increased thereafter. Adult crabs were observed to be strong hyper-hypo-osmoregulators in a salinity range from at least 1 per thousand to 44 per thousand. The unusually early appearance of strong regulatory capabilities, particularly in dilute media, is interpreted as a physiological preadaptation that should have facilitated the evolutionary process of adaptive radiation in non-marine environments on Jamaica.

Immunocytochemical detection of acetylated alpha-tubulin and Drosophila synapsin in the embryonic crustacean nervous system

The caridean shrimp Palaemonetes argentinus Nobili is well suited for studying developmental aspects of the crustacean nervous system due to its rapid embryonic development and short reproductive cycle. In the present paper, we demonstrate the pattern of central axonal pathways in embryos of this species by immunohistochemical detection of acetylated alpha-tubulin. Development of the neuropil was elucidated by using an antibody to a Drosophila synapsin. In the ventral nerve cord, the segmental axonal scaffold consists of the paired lateral connectives, a median connective, and the anterior and posterior commissures. Three nerve roots were found to branch off each ganglion anlage, i.e. the main segmental nerve root, a smaller posterior nerve and the intersegmental nerve. However, this pattern is different in the mandibular segment where no intersegmental nerve and only one commissure was encountered. The anterior part of the brain consists of a tritocerebral and a deutocerebral anlage as well asthe anlage of the medial protocerebrum. The latter is connected to the eyestalk via the protocerebral tract. The sequence of development of the eyestalk ganglia was demonstrated in specimens which were stained with the anti-synapsin antibody. The medulla terminalis and medulla interna are the first neuropils to appear and are still fused in early stages. Later, the medulla interna splits off the medulla terminalis. The lamina ganglionaris is the last of the eyestalk neuropils to develop. These findings prove that immunocytochemistry against acetylated alpha-tubulin and synapsin are valuable tools for studying the development of the crustacean nervous system.

Psychiatric symptoms in clients presenting for commercial weight reduction treatment

OBJECTIVE

To study the prevalence and severity of psychiatric symptoms in a group of clients presenting to a commercial weight reduction program, compared with a group of patients seeking outpatient medical treatment.

METHOD

Sixty-six clients presenting for commercial weight loss treatment and 52 patients presenting for general outpatient medical treatment were given self-report measures of anxiety (Spielberger State and Trait Inventory), depression (Beck Depression Inventory), body dissatisfaction (Body Shape Questionnaire), and overall impairment in functioning (Sheehan Disability Scale).

RESULTS

Weight loss clients had significantly higher rates of depressive symptomatology and psychosocial disability than patients presenting for medical treatment. Weight loss clients were also more likely to demonstrate body dissatisfaction regardless of actual weight. Levels of anxiety were not significantly different, despite the medical group reporting themselves to be in poorer health as compared with the weight loss group.

DISCUSSION

Regular screening for psychiatric symptoms in clients presenting for commercial weight reduction treatment may be valuable as this group may constitute an as yet unidentified cohort requiring psychiatric intervention.

Efforts in primary-care practice to control tobacco use

In this article, the authors findings lead them to conclude that because of the devastating effects of smoking on health, the public could experience widespread health benefits if primary care physicians became more active in encouraging patients to stop smoking.

Ecdysteroid levels during the larval development of the spider crab Hyas araneus

Ecdysteroid levels were determined by radioimmunoassay during the larval development of the spider crab Hyas araneus L. In each of the three larval instars (zoea I, zoea II, megalopa) a minimum in ecdysteroid levels was found during early postmoult and a maximum during premoult. The amounts of ecdysteroids increased during development and reached maxima of 93, 137, and 165 pg ecdysone equivalents per larva in zoea I, zoea II, and megalopa, respectively. Ecdysteroid concentrations per unit of body dry weight or carbon increased during each moulting cycle, but the average values showed decreasing tendency from the first to the last instar. The main ecdysteroid in all larval instars and during the moulting cycle was 20-OH-ecdysone, and practically no ecdysone could be detected by HPLC-RIA.

[Quantitative whole-body skeletal scintigraphy with a gamma camera and pinhole collimator]

Quantitative evaluation of whole-body bone scans is valuable for the description of metabolic activity in systemic bone disease and provides parameters of whole-body activity retention up to 24 h after injection of the radiopharmacon, of bone to soft tissue relation and of the activity in the epiphysis and diaphysis. A combination of whole-body imaging by a gamma-camera with pinhole collimator and a series of single pictures evaluated by the ROI technique is able to record these parameters with sufficient precision. This is demonstrated by measuring phantoms, and patients with and without bone disease. In 34 patients with systemic bone disease the quantitative parameters are altered partially, the changes however are insufficient for their differential diagnosis.

[Interference factors in the in vivo diagnosis of the thyroid]

Anamnestic iodine contamination and medication with thyroid drugs were registered in 260 patients of a clinical thyroid care unit and 200 patients of a thyroid doctor's office in the southern German endemic goiter region. We found in the university clinic 54% patients with interfering factors, 30% with iodine contamination and 20% with multiple interferences. In the physician's practice there were 18%, nearly all treated with thyroid hormone. The influence of those factors on thyroidal technetium uptake and the resulting restriction on its diagnostic value is discussed.

Die quantifizierende GanzkörperSkelettszintigraphie mit Gamma-Camera und Pinhole-Kollimator

Die quantitative Auswertung von Ganzkörper-Skelettszintigrammen dient bei generalisierten Skeletterkrankungen der Beschreibung der Skelettstoffwechselaktivität und umfaßt die Parameter Ganzkörperaktivitätsretention möglichst lange Zeit nach Injektion, einen Skelett-Weichteil-Quotienten und eine Aussage über das Verhältnis der Aktivität in Spongiosa und Compacta. Es wird an Phantomversuchen, an Messungen bei Patienten ohne Skeletterkrankung und an Patienten mit Skelettsystemerkrankungen gezeigt, daß eine Aufnahmetechnik des Ganzkörperszintigramms mit Gamma-Camera und Pinhole-Kollimator sowie einer anschließenden Serie von Einzelszintigrammen mit Auswertung in ROI-Technik imstande ist, diese Parameter hinreichend genau zu erfassen. An 34 Patienten mit generalisierten Skeletterkrankungen wird allerdings dargestellt, daß diese Parameter zwar zur Beschreibung von Skelett-Systemerkrankungen, nicht jedoch zu deren Differentialdiagnose geeignet sind.

Störfaktoren bei der In-vivo-Diagnostik der Schilddrüse

An 260 Patienten, die zur Schilddrüsendiagnostik in einer nuklearmedizinischen Universitätsabteilung vorgestellt wurden, und 200 Patienten einer Schilddrüsenpraxis im Kropfendemiegebiet des schwäbischen Oberlands wurde anamnestisch die Vorbelastung der Schilddrüse mit Jod oder Medikamenten erfaßt. An der Klinik fanden sich 54% vorbelastete, davon 30% jodkontaminierte und 20% mehrfach belastete Patienten. In der Praxis waren 18% der Patienten vorbehandelt, die Mehrzahl ausschließlich mit Schilddrüsenhormonen. Der Einfluß dieser Vorbelastung auf den thyreoidalen Technetium-Uptake und die daraus resultierende Einschränkung seiner diagnostischen Aussage werden diskutiert.

[Skeletal scintigraphy in the care of breast cancer . Long-term follow-up over 8 years]

In a retrospective study 1704 whole-body bone scans of 807 female and 7 male patients with breast cancer performed from 1974 to 1981 were reevaluated considering the incidence of bone metastases in staging and follow-up, the response of metastatic uptake to treatment as well as sensitivity and specificity of the diagnostic procedure. The yield of positive bone scans in staging was 23.7% at all and depended on T stage with a comparably high incidence of 8.8% in stage T1 and T2. Subsequently within 6 years follow-up further 26% were developing bone metastases. The long time response of known metastases to treatment was ambient, 65% of the scans found without some essential change. The incidence of bone metastases combined with a calculated sensitivity of 93% and specificity of 91% is justifying the use of bone scans in every stage and every phase of assessing breast cancer.

[Quantitative lung perfusion scintigraphy in lung function diagnosis]

A new method is described for quantitative evaluation in lung perfusion scintigraphy, which allows to conclude from the increased perfusion of normal lung-tissue to a virtual total lung perfusion. The relationship between this and the real total lung perfusion leads to the pulmonary perfusion defects in per cent. The findings of a comparison of 40 patients between the perfusion scan method and the lung function tests is presented, which proves the validity of the new method. It is shown that restrictive lung diseases have a good and obstructive have a bad correlation. It is demonstrated furthermore that the perfusion defects of bronchogenic carcinoma can be quantified very well by the method.

[Gated blood pool scanning in the diagnosis of coronary disease. A prospective study to compare cineventriculography and 2-dimensional echocardiography]

38 patients with clinically suspected coronary artery disease were studied by contrast ventriculography, 2-dimensional echocardiography and multiple gated blood pool imaging (MUGA) without stress. The results were compared with each other and with the final diagnosis confirmed by coronary angiography. The left ventricular ejection fraction is evaluated nearly identically and with sufficient accuracy by both non-invasive methods, local motion abnormalities are on the other hand diagnosed in the best way by MUGA imaging in our own cases.

[Results of lung perfusion and lung ventilation scintigraphy following surgery of diaphragmatic defects]

To elucidate the question whether congenital hernias of the diaphragm and diaphragmatic defects are often combined with primary hypoplasia of the pulmonary vascular bed, we performed lung scintigraphy in twenty children after operation of a diaphragmatic defect. We found in 66% of the cases persisting perfusion disorders of the operated side. However, this does not prove primary vascular hypoplasia, because a postoperative ventilation disorder with secondary perfusion disorder cannot be excluded. Ventilation scintigraphy with krypton-81m showed good results in all cases, so that the combination of good ventilation and restricted perfusion indicates primary vascular hypoplasia.

[Quantitative whole-body bone scintigraphy. III. Clinical significance for the diagnosis of bone metastases, systemic bone diseases and diseases of the joint (author's transl)]

Quantitative whole-body bone scans were performed on 277 patients with bone metastases, diseases of the joint and systemic bone diseases in order to evaluate the clinical significance of quantitative and kinetic data in bone imaging. Metastases and other focal bone diseases are recognizable and quantifiable by the method; however, sensitivity and specificity of bone imaging are not enhanced. In metabolic bone diseases, with the exception of osteoporosis, kinetic data facilitate the analysis of bone scans. Typical signs of osteomalacia, hyperparathyroidism and renal osteodystrophy--increased retention of the activity in the skeleton and increased bone/soft tissue ratios as well as a generally changed distribution of radioactivity--are only recognizable by quantitative imaging.

[Quantitative whole-body bone scintigraphy. II. Pharmacokinetics of osteotropic radiopharmaceuticals (author's transl)]

85Sr, 99mTc-Sn-pyrophosphate and 99mTc-Sn-methylene-diphosphonate, the most important agents for skeletal imaging, are compared with each other by calculation of the plasma clearance and the urinary excretion and by a series of quantitative whole-body scans. 85Sr the distribution volume in equilibrium is the largest, shifting of activity is demonstrable for several days after injection. 99mTc-Sn-MDP is excreted most quickly, equilibrium is reached early. There is no significant difference in skeletal uptake between the phosphate complexes. The distribution however is different: 85Sr is localized to a greater extent in the extremities, the phosphate complexes more in the trunk, 99mTc-Sn-MDP and 85Sr nearer the joints than 99mTc-Sn-pyrophosphate.

[The scintigraphic diagnosis and follow-up of injuries to the epiphyseal plates (author's transl)]

Injuries to the epiphysel plates without involvement of the epiphyses or metaphyses, such as crush fractures or pure epiphysiolysis may be difficult to diagnose radiologically. Thirteen bone scans after damage to the growth plate have been performed on eight children. These indicate that these scans are able to diagnose lesions of the epiphyseal plates at an early stage and with certainty. The scintigrams also provide information concerning the healing process of the plate; they indicate when healing has been completed and when the extremity can be used for weight-bearing again. Radiation exposure of the children during scintigraphy with 99mTc-polyphosphate is within acceptable limits.

Die quantitative Ganzkörper-Skelettszintigraphie

Die quantitative Ganzkörper-Skelettszintigraphie, in der das Originalszintigramm durch die zusätzliche Angabe kinetischer Parameter und den automatischen lokalen Vergleich mit einem Normalszintigramm ergänzt wird, wurde an 277 Patienten mit Knochenmetastasen, Gelenkerkrankungen und Skelett-Systemerkrankungen auf ihren klinischen Wert überprüft. Metastasen und andere herdförmige Skeletterkrankungen sind mit dieser Technik erkennbar und in ihrer Aktivität quantifizierbar, Sensitivität und Spezifität der Skelettszintigraphie werden jedoch durch die quantitative Auswertung bei der Metastasensuche nicht erhöht. Die Diagnostik metabolischer Skeletterkrankungen mit Ausnahme der Osteoporose wird dagegen durch die Einbeziehung kinetischer Parameter in die Szintigrammauswertung erheblich bereichert, da die mit Osteomalacie, Hyperparathyreoidismus und renaler Osteodystrophie verbundene erhöhte Aktivitätseinlagerung im Skelett und allgemeine Aktivitätsumverteilung nur im quantitativen Szintigramm erkennbar ist.

Die quantitative Ganzkörper-Skelettszintigraphie

Die quantitative Ganzkörper-Skelettszintigraphie wird als Auswertemethode für digitale Skelettszintigramme vorgestellt. Sie zeichnet sich durch die konsequente Anwendung der Prinzipien einer quantitativen Szintigraphie mit Doppel - detektor-Scanner, Schwächungs- und Organdickenkorrektur aus. Sie erlaubt damit in einem digital erfaßten Ganzkörper-Skelettszintigramm die Bestimmung von retinierter Gesamtaktivität, Verhältnis von Skelett-, Organ- und Weichteilaktivität und prozentualer Aktivitätsverteilung auf einzelne Skelettabschnitte. Der Meßfehler liegt dabei im Schnitt um 10%. Der Vergleich mit einem standardisierten Normalszintigramm ergibt einen lokalen Anreicherungsquotienten für herdförmige und diffuse Knochenveränderungen und damit ein direktes Maß für die Erhöhung der Knochenstoffwechselaktivität. Der Gang der Szintigrammauswertung ist mit Hilfe von Computerprogrammen weitgehend automatisiert. Über die Anwendung der Methode für die Untersuchung der Kinetik osteotroper Radiopharmaka und klinische Ergebnisse soll in weiteren Arbeiten berichtet werden.

Die quantitative Ganzkörper-Skelettszintigraphie

Mit den konventionellen pharmakokinetischen Methoden der Bestimmung von Plasmaclearance und Ausscheidung sowie einer Serie von quantitativen Ganzkörperszintigrammen wird das Verhalten der osteotropen Radiopharmaka 85Sr, 99mTc-Sn-Pyrophosphat und 99mTc-Sn-Methylendiphosphonat überprüft und verglichen. 85Sr weist den größten Verteilungsraum im Gleichgewicht und Aktivitätsverschiebungen noch Tage nach der Injektion auf, 99mTc-Sn-MDP wird am raschesten ausgeschieden und erreicht am schnellsten das Gleichgewicht zwischen Skelett- und Weichteilaktivität. Die prozentuale Einlagerung ins Skelett unterscheidet sich nicht signifikant zwischen den Phosphatkomplexen. Zum Scanzeitpunkt ist 85Sr mehr im Extremitätenskelett, die 99mTc-Phosphatkomplexe mehr im Stammskelett lokahsiert. 99mTc-Sn- MDP und 85Sr weisen eine stärkere Betonung der gelenknahen Skelettabschnitte auf als 99mTc-Sn-Pyrophosphat.

[First clinical experience with axial emission computer tomography (author's transl)]

104 examinations were carried out on 81 patients with a new commercial emission computer tomographic scanner. The technique provides additional information in half the brain scans, but only in one third of liver scans. No indications for this examination could be discovered in a relatively small clinical material for the examination of the kidneys or the skeleton. Other organs were not included in this assessment. The authors confirm reports in the literature which show that this method is not particularly valuable for finding pathology. It finds its application in conforming or excluding suspected abnormalities and for better localisation and delineation of lesions, thereby aiding differential diagnosis. However, further technical improvements and increased clinical experiency may increase the applicability of the technique.