Development of a prototypic, field-usable diagnostic tool for the detection of gram-positive cocci-induced mastitis in cattle

BACKGROUND

Bovine mastitis is one of the most widespread diseases affecting cattle, leading to significant losses for the dairy industry. Currently, the so-called gold standard in mastitis diagnosis involves determining the somatic cell count (SCC). Apart from a number of advantages, this method has one serious flaw: It does not identify the etiological factor causing a particular infection, making it impossible to introduce targeted antimicrobial therapy. This can contribute to multidrug-resistance in bacterial species. The diagnostic market lacks a test that has the advantages of SCC and also recognizes the species of pathogen causing the inflammation. Therefore, the aim of our study was to develop a lateral flow immunoassay (LFIA) based on elongation factor Tu for identifying most prevalent Gram-positive cocci responsible for causing mastitis including Streptococcus uberis, Streptococcus agalactiae and Staphylococcus aureus.

RESULTS

As a result, we showed that the assay for S. uberis detection demonstrated a specificity of 89.02%, a sensitivity of 43.59%, and an accuracy of 80.3%. In turn, the second variant - assay for Gram-positive cocci reached a specificity of 95.59%, a sensitivity of 43.28%, and an accuracy of 78.33%.

CONCLUSIONS

Our study shows that EF-Tu is a promising target for LFIA and we have delivered evidence that further evaluation could improve test parameters and fill the gap in the mastitis diagnostics market.

Inhibition of Toxoplasma gondii by 1,2,4-triazole-based compounds: marked improvement in selectivity relative to the standard therapy pyrimethamine and sulfadiazine

A safer treatment for toxoplasmosis would be achieved by improving the selectivity profile of novel chemotherapeutics compared to the standard therapy pyrimethamine (PYR) and sulfadiazine (SDZ). We previously reported on the identification of the compounds with imidazole-thiosemicarbazide scaffold as potent and selective anti-Toxoplasma gondii (T. gondii) agents. In our current research, we report on the optimisation of this chemical scaffold leading to the discovery cyclic analogue 20 b with s-triazole core structure. This compound displayed prominent CC₃₀ to IC₅₀ selectivity index (SI) of 70.72, making it 160-fold more selective than SDZ, 11-fold more selective than PYR, and 4-fold more selective than trimethoprim (TRI). Additionally, this compound possesses prerequisite drug-like anti-Toxoplasma properties to advance into preclinical development; it showed ability to cross the BBB, did not induce genotoxic and haemolytic changes in human cells, and as well as it was characterised by low cellular toxicity.

2,4-Disubstituted pyridine derivatives are effective against intracellular and biofilm-forming tubercle bacilli

It was recently reported that 4-substituted picolinohydrazonamides carrying hydrophilic cyclic amines, such as morpholine and pyrrolidine, at the end of their thiosemicarbazide chain have potent antimycobacterial activity in vitro at concentrations below 1 μg/ml. Here, two selected compounds, 2,4-disubstituted pyridine derivatives 11 and 15, revealed significant bactericidal activity against Mycobacterium tuberculosis localized intracellularly within human macrophages, as well as against biofilm-forming tubercle bacilli. Mutants were selected that were resistant to the investigated compounds at an efficiency similar to that identified in the presence of the first line antituberculosis drug rifampicin. The resistant mutants were viable in the presence of the tested compounds exclusively on solid media. Genome-wide sequencing of the mutants selected in the presence of compound 11 revealed the accumulation of nonsynonymous mutations in the mmpR5 gene encoding a transcriptional repressor of the MmpS5-MmpL5 efflux pump, whose upregulation has been associated with bedaquiline resistance. The depletion of MmpR5 in wild-type M. tuberculosis using CRISPR–Cas9 technology increased the resistance of this strain to compound 11. Mass spectrometry-based proteomics (LC–MS/MS) of wild-type tubercle bacilli growing in subinhibitory concentrations of compounds 11 or 15 revealed 15 overproduced proteins not detectable in the control cells, including virulence-related proteins.

4-Arylthiosemicarbazide Derivatives as Toxoplasmic Aromatic Amino Acid Hydroxylase Inhibitors and Anti-inflammatory Agents

Approximately one-third of the human population is infected with the intracellular cosmopolitan protozoan Toxoplasma gondii (Tg), and a specific treatment for this parasite is still needed. Additionally, the increasing resistance of Tg to drugs has become a challenge for numerous research centers. The high selectivity of a compound toward the protozoan, along with low cytotoxicity toward the host cells, form the basis for further research, which aims at determining the molecular targets of the active compounds. Thiosemicarbazide derivatives are biologically active organic compounds. Previous studies on the initial preselection of 58 new 4-arylthiosemicarbazide derivatives in terms of their anti-Tg activity and selectivity made it possible to select two promising derivatives for further research. One of the important amino acids involved in the proliferation of Tg and the formation of parasitophorous vacuoles is tyrosine, which is converted by two unique aromatic amino acid hydroxylases to levodopa. Enzymatic studies with two derivatives (R: para-nitro and meta-iodo) and recombinant aromatic amino acid hydroxylase (AAHs) obtained in the E. coli expression system were performed, and the results indicated that toxoplasmic AAHs are a molecular target for 4-arylthiosemicarbazide derivatives. Moreover, the drug affinity responsive target stability assay also confirmed that the selected compounds bind to AAHs. Additionally, the anti-inflammatory activity of these derivatives was tested using THP1-Blue™ NF-κB reporter cells due to the similarity of the thiosemicarbazide scaffold to thiosemicarbazone, both of which are known NF-κB pathway inhibitors.

4-Arylthiosemicarbazide derivatives as a new class of tyrosinase inhibitors and anti-Toxoplasma gondii agents

We report herein anti-proliferation effects of 4-arylthiosemicarbazides, with a cyclopentane substitution at N1 position, on highly virulent RH strain of Toxoplasma gondii. Among them, the highest in vitro anti-Toxoplasma activity was found with the meta-iodo derivative. Further experiments demonstrated inhibitory effects of thiosemicarbazides on tyrosinase (Tyr) activity, and good correlation was found between percentage of Tyr inhibition and IC_50Tg. To confirm the concept that thiosemicarbazides are able to disrupt tyrosine metabolism in Toxoplasma tachyzoites, the most potent Tyr inhibitors were tested for their efficacy of T. gondii growth inhibition. All of them significantly reduced the number of tachyzoites in the parasitophorous vacuoles (PVs) compared to untreated cells, as well as inhibited tachyzoites growth by impeding cell division. Collectively, these results indicate that compounds with the thiosemicarbazide scaffold are able to disrupt tyrosine metabolism in Toxoplasma tachyzoites by deregulation of their crucial enzyme tyrosine hydroxylase (TyrH).

1,3,4-Thiadiazoles Effectively Inhibit Proliferation of Toxoplasma gondii

Congenital and acquired toxoplasmosis caused by the food- and water-born parasite Toxoplasma gondii (T. gondii) is one of the most prevalent zoonotic infection of global importance. T. gondii is an obligate intracellular parasite with limited capacity for extracellular survival, thus a successful, efficient and robust host cell invasion process is crucial for its survival, proliferation and transmission. In this study, we screened a series of novel 1,3,4-thiadiazole-2-halophenylamines functionalized at the C5 position with the imidazole ring (1b-12b) for their effects on T. gondii host cell invasion and proliferation. To achieve this goal, these compounds were initially subjected to in vitro assays to assess their cytotoxicity on human fibroblasts and then antiparasitic efficacy. Results showed that all of them compare favorably to control drugs sulfadiazine and trimethoprim in terms of T. gondii growth inhibition (IC50) and selectivity toward the parasite, expressed as selectivity index (SI). Subsequently, the most potent of them with meta-fluoro 2b, meta-chloro 5b, meta-bromo 8b, meta-iodo 11b and para-iodo 12b substitution were tested for their efficacy in inhibition of tachyzoites invasion and subsequent proliferation by direct action on established intracellular infection. All the compounds significantly inhibited the parasite invasion and intracellular proliferation via direct action on both tachyzoites and parasitophorous vacuoles formation. The most effective was para-iodo derivative 12b that caused reduction in the percentage of infected host cells by 44% and number of tachyzoites per vacuole by 93% compared to non-treated host cells. Collectively, these studies indicate that 1,3,4-thiadiazoles 1b-12b, especially 12b with IC50 of 4.70 µg/mL and SI of 20.89, could be considered as early hit compounds for future design and synthesis of anti-Toxoplasma agents that effectively and selectively block the invasion and subsequent proliferation of T. gondii into host cells.

Benzo[b]thiophene-thiazoles as potent anti-Toxoplasma gondii agents: Design, synthesis, tyrosinase/tyrosine hydroxylase inhibitors, molecular docking study, and antioxidant activity

Synthesis and investigation of anti-Toxoplasma gondii activity of novel thiazoles containing benzo [b]thiophene moiety are presented. Among the derivatives, compound 3k with adamantyl group shows exceptionally high potency against Me49 strain with IC₅₀ (8.74 μM) value which is significantly lower than the activity of trimethoprim (IC₅₀ 39.23 μM). In addition, compounds 3a, 3b and 3k showed significant activity against RH strain (IC₅₀ 51.88-83.49 μM). The results of the cytotoxicity evaluation showed that Toxoplasma gondii growth was inhibited at non-cytotoxic concentrations for the mammalian L929 fibroblast (CC₃₀ ∼ 880 μM). The most active compound 3k showed tyrosinase inhibition effect, with IC₅₀ value of 328.5 μM. The binding energies calculated for compounds 3a-3e, 3k are strongly correlated with the experimentally determined values of tyrosinase inhibition activity. Moreover, the binding energies corresponding to the same ligands and calculated for both tyrosinase and tyrosine hydroxylase are also correlated with each other, suggesting that tyrosinase inhibitors may also have an inhibitory effect on tyrosine hydroxylase. Compounds 3j and 3k have also very strong antioxidant activity (IC₅₀ 15.9 and 15.5 μM), respectively, which is ten times higher than well-known antioxidant BHT.

Systematic Identification of Thiosemicarbazides for Inhibition of Toxoplasma gondii Growth In Vitro

One of the key stages in the development of new therapies in the treatment of toxoplasmosis is the identification of new non-toxic small molecules with high specificity to Toxoplasma gondii. In the search for such structures, thiosemicarbazide-based compounds have emerged as a novel and promising leads. Here, a series of imidazole-thiosemicarbazides with suitable properties for CNS penetration was evaluated to determine the structural requirements needed for potent anti-Toxoplasma gondii activity. The best 4-arylthiosemicarbazides 3 and 4 showed much higher potency when compared to sulfadiazine at concentrations that are non-toxic to the host cells, indicating a high selectivity of their anti-toxoplasma activity.

Thiazoles with cyclopropyl fragment as antifungal, anticonvulsant, and anti-Toxoplasma gondii agents: synthesis, toxicity evaluation, and molecular docking study

Synthesis and investigation of antifungal, anticonvulsant and anti-Toxoplasma gondii activities of ten novel (2-(cyclopropylmethylidene)hydrazinyl)thiazole 3a-3j are presented. Among the derivatives, compounds 3a-3d and 3f-3j possess very high activity against Candida spp. ATCC with MIC = 0.015-7.81 µg/ml. Compounds 3a-3d and 3f-3j possess also very high activity towards most of strains of Candida spp. isolated from clinical materials with MIC = 0.015-7.81 µg/ml. The activity of these compounds is similar and even higher than the activity of nystatin used as positive control. Additionally, compounds 3c and 3e showed interesting anticonvulsant activities in the MES test, whereas compounds 3f and 3i demonstrated the anticonvulsant activity in PTZ-induced seizures. Noteworthy, none of these compounds impaired animals' motor skills in the rotarod test. Moreover, thiazoles 3a, 3h, and 3j showed significant anti-Toxoplasma gondii activity, with IC50 values 31-52 times lower than those observed for sulfadiazine. The results of the cytotoxicity evaluation, anti-Candida spp. and anti-Toxoplasma gondii activity studies showed that Candida spp. and Toxoplasma gondii growth was inhibited at non-cytotoxic concentrations for the mouse L929 fibroblast and the African green monkey kidney (VERO) cells. Molecular docking studies indicated secreted aspartic proteinase (SAP) as possible antifungal target.

[Pseudopancreatitis in entero-invasive salmonellosis]

The incidence of pancreatitis in bacterial enterocolitis is disputed. Two cases of young patients with S. enteritidis-induced enterocolitis and markedly elevated amylase and lipase blood levels are described. In both patients there were neither clinical nor ultrasonographic signs of pancreatitis. Furthermore, both had increased intestinal permeability for oral 51Cr-EDTA, a condition discussed as "leaky gut" in other publications. In one patient enzyme levels and 51Cr-EDTA resorption became rapidly normal, while in the other the values remained elevated after a 7-month interval with stool culture negative. Enhanced intestinal absorption of 51Cr-EDTA (mw 391) suggests--but does not definitely prove--an inflammatory response of the mucosa leading to increased intestinal permeability, which in turn may allow resorption of amylase (mw 62,000), lipase (43,000) or other macromolecules. Performance of a 51Cr-EDTA resorption test may be helpful in cases of clinical uncertainty.

In vitro and in vivo testing of the dopamine D1 ligand [123I]SCH 23982 with respect to its potential application in SPET investigations

[123I]SCH 23982, a dopamine D1 ligand, was labelled in a large scale process and then tested in vitro for binding to rat brain sections and membranes. Because of the promising values of KD = 1.5 x 10(-10) M and Bmax = 0.7 x 10(-11) mol/g, in vivo evaluation was performed on rats and normal volunteers to test its possible usefulness for SPET imaging. In competition experiments, a higher binding in the presence of sulpiride was found while ketanserin displaced [123I]SCH 23982 only at a 10,000-fold excess. Differences between rats and men were seen with respect to their metabolism. SPET investigations failed because the washout of [123I]SCH 23982 was too rapid.

123I-SCH 23982 is not suitable for dopamine D1 receptor imaging in vivo in the human brain

The tracer 123I-SCH 23982 was tested with regard to its ability to image dopamine D1 receptor in the human brain in vivo with single photon emission computed tomography (SPECT). The tracer did not reach equilibrium with regard to its binding to dopamine D1 receptors, presumably owing to fast metabolism to hydrophilic products and deiodination. It is concluded that 123I-SCH 23982 is not suitable for dopamine D1 receptor imaging with SPECT in the human brain.

Evaluation of a multicentre study with Iomazenil--a benzodiazepine receptor ligand

After showing in an earlier publication that Iomazenil is a potent benzodiazepine receptor antagonist, the substance has been distributed to 11 clinical centres in Europe for further tests. The protocol asked for volunteers, epileptic cases and patients with Alzheimer's disease. Prior to the Iomazenil examination, flow images by perfusamine or HMPAO were required, and as comparative methods EEG, computed tomography (CT) and magnetic resonance imaging (MRI) were performed. The results allowed first the determination of the normal distribution of the benzodiazepine receptors in the human brain. The highest uptake was found in medial occipital cortex. Second, the evaluation of the epileptic cases shows a 100% positive prediction value for Iomazenil compared to 92% for flow images. Negative prediction values were calculated as 81% for Iomazenil and 54% for flow images. Furthermore, one group reported the successful diagnosis of Alzheimer's disease at an early stage. The visual image examination was tentatively compared to a more objective semiquantitative one based on quotients of corresponding left/right regions of interest. This semiquantitative method has not proved successful yet, but the problems have been identified. A more precise protocol for further studies is therefore proposed.

[The contribution of single-photon emission-computed tomography in cerebral function diagnosis]

Single photon emission computed tomography (SPECT) makes it possible to visualize physiological and chemical processes in the cerebrum. In this technique, single photon emitting nuclides such as 99m technetium and 123 iodine, which are tagged to other compounds, or 133xenon, are used for the study of several clinical conditions. After injection of the radiopharmaceutic agent the radioactivity is measured by a rotating gamma-camera from numerous directions. Based on the measured values, its distribution within the brain can be computed and transformed in tomographic slices. We present our experience with the method in clinical practice using preferentially N-isopropyl-(123I)-p-iodoamphetamine (123I-IMP) and 99mTc hydroxymethyl-propylene-amine-oxime (99mTc-HMPAO). These substances are distributed in accordance with regional cerebral blood flow (rCBF). Hitherto, the application of the method has concentrated on the study of cerebrovascular disease and epilepsy. SPECT has contributed to a better understanding of the pathophysiological processes and their dynamics after ischemic infarction. The method also provides essential insights in epileptics. In partial epilepsy, a focus of reduced or enhanced tracer activity can be ascertained, dependent on the timing of the examination, in the interictal and ictal stage respectively. Even in the early course of senile dementia of Alzheimer type, zones of diminished neuronal activity in temporo-parietal and frontal cortex are demarcated. Preliminary results in psychiatric diseases and parkinsonism need further confirmation. In this connection future interest will focus especially upon the use of receptor ligands.

[Tumor scintigraphy with cobalt bleomycin in ORL tumors]

Our experiences with cobalt bleomycin scintigraphy in the treatment planning of ORL tumors are described. 142 scintigrams taken from 127 patients have been examined. As is shown by our investigation, cobalt bleomycin scintigraphy is a good examination method, however, too much expenditure is needed to have the necessary data for therapy planning. To our opinion, the information obtained in oto-rhino-laryngology by an exact clinical examination is as good as that of cobalt bleomycin scintigraphy. Our treatment schemes had only to be revised in some exceptional cases.

[Semiquantitative display of regional cerebral blood flow and neuronal function using N-isopropyl-(123I)-p-iodoamphetamine (IMP) and emission tomography]

Between June 1983 and March 1985 197 patients were examined with 123I-IMP brain scintigraphy and ECT. They had various neurological diseases, the majority suffered from cerebrovascular affections. The reference for pathological findings was a group of 14 healthy volunteers. A visual interpretation of the ECT-slices alone is not reliable enough. A semiquantitative assessment of perfusion abnormalities seems to be very important, especially in diffuse or bilateral alterations. The proposed semiquantitative evaluation makes use of the total cerebral accumulation in the control group (35.6 +/- 4.3 cts/pixel/mCi/min) and right-left ratios of 14 paired and fixed regions of interest (ROI) in three ECT slices. The ROIs are related to the anatomical flow supply areas in the brain. The right-left ratios are around 1.0 with a physiological asymmetry of +/- less than 2% (standard deviation). The asymmetry is an important parameter in assessing presence and severity of disease. If pathological findings are diffuse or symmetric, the visual interpretation of scintigrams or the calculation of right-left ratios are often unsuccessful. Thus, the same ROI-data were separated for the right and left hemisphere and drawn as cts/ROI/pixel/mCi in diagrams as profile. The diagram demonstrates perfusion abnormalities semiquantitatively without using calculation of asymmetry, since asymmetry alone cannot differentiate between hypoperfusion of one and hyperperfusion of the contralateral side.

Ein Beitrag zur semiquantitativen Darstellung der regionalen Hirndurchblutung und neuronalen Funktion mittels N-isopropyl-(123J)-p-Jodoamphetamin (IMP) und Emissionstomographie

Von Juni 1983 bis März 1985 wurden 197 Patienten eines gemischten neurologischen Krankengutes mit der 123J-IMP-Szintigrafie untersucht. Das zum Vergleich herangezogene Normkollektiv umfaßte 14 Probanden. Mit der alleinigen visuellen Bildbetrachtung der ECT-Schnitte können pathologische Befunde übersehen werden; positive Befunde können außerdem nicht objektiviert werden. Es müssen deshalb weitere, semiquantitative Kriterien herangezogen werden, um die Zuverlässigkeit der Auswertung zu erhöhen. Als Referenzwert der globalen zerebralen Speicherung diente das Normkollektiv mit 35,6 ± 4,3 cts/pixel/ mCi/min und die Einzeichnung fixer, anatomisch gefäßbezogener ROIs in die entsprechenden ECT-Schnitte. Die Impulszahlen der insgesamt 14 ROIs erlaubten einen exakten Seitenvergleich korrespondierender Stromgebiete beider Hirnhemisphären und des Kleinhirns. Die Ausprägung der Asymmetrie (Standardabweichung <2%) gibt Hinweise über das Ausmaß einer Perfusionseinschränkung, vor allem in Verlaufsuntersuchungen nach Therapie. Zur Unterscheidung einer durch Minderdurchblutung der einen Seite oder Mehrbelegung der anderen Seite verursachten Asymmetrie wurden die ROI-Daten aller Regionen beider Hemisphären getrennt als cts/ROI/pixel/ mCi im Profil dargestellt. Der Vergleich der Patientendaten mit dem Normprofil unter Berücksichtigung der Standardabweichungen erlaubt eine Objektivierung von Speicherabnormitäten ohne Seitenvergleich, da diffuse Hirnprozesse oder bilaterale Perfusionsstörungen nicht notwendigerweise zu einer feststellbaren Asymmetrie führen.

131-Iodine capsules in thyroid therapy: an individually controlled study of their uptake kinetics as compared to liquid 131-iodine

We investigated the uptake of therapeutic doses of 131-Iodine in capsular form which were given to 16 patients with benign thyroid disease, and compared it to the uptake of a diagnostic dose of liquid 131-Iodine given to the same patients. The aim of this study was to determine the additional radiation dose sustained by the gastric mucosa, and thus, to establish the safety of this galenic form of 131I. It was found that the average capsule-dissolution time was about 12 min, with a large standard deviation of about 7 min. Using these data and a theoretical radiation-dose calculation, we estimated that the maximum dose to the gastric mucosa was approximately 250 rad (250 cGy) for a therapeutic activity of 5 mCi (185 MBq), which is the maximum dose which may be given as single application to out-patients in Switzerland. Thus, 131I administered in capsular form is a safe galenic form for therapeutic use in patients with thyroid disease.

Regional quantitative noninvasive assessment of cerebral perfusion and function with N-isopropyl-[123I]p-iodoamphetamine

Although several reports on the clinical usefulness of N-isopropyl-[123]p-iodoamphetamine (IMP) in the diagnosis of cerebral disease have appeared in the literature, quantitative, noninvasive measurements of regional cerebral blood flow with this method pose difficulties because cerebral IMP uptake not only depends on cerebral perfusion but also on cerebral function. Rather than trying to develop a method to measure cerebral perfusion with IMP, we have chosen to test a method to quantitatively evaluate planar and emission computed tomographic (ECT) studies by comparing the data obtained in patients with established pathology (n = 51, number of scans = 54) with the data obtained in a group of normal individuals (n = 10, number of scans = 11). Using this method, absolute cerebral IMP uptake (counts/pixel/mCi/min) and planar anterior right-left ratios were obtained. Also measured were right-left ratios obtained from 12 paired regions in three ECT slices. In the control group, we found an IMP uptake of 35.6 +/- 4.3 cts/pixel/mCi/min and right-left ratios around 1.00 (s.d. less than 2%). The evaluation of the patients cerebral IMP uptake asymmetries relative to the normal standard values is a useful adjunct to qualitative image analysis in assessing the presence and severity of disease, as qualitative analysis is prone to false-positive and negative results. Cerebral IMP uptake as measured in cts/pixel/mCi/min is abnormal only in severe cerebral disease and therefore generally a less helpful parameter.

Suprasellar arachnoidal cyst as a cause of early puberty

Puberty developed in a boy before age 12 years despite a marked delay in skeletal development. A large suprasellar arachnoidal cyst was found. Such cysts may be a cause of precocious puberty.

[Difficulties in the differential diagnosis of a non-traumatic, active myositis ossificans during pregnancy (author's transl)]

A 28 year old patient complained of sensory disturbances and pain in the right upper arm during pregnancy. During the 32nd week of her pregnancy, a large painful mass developed in the flexor muscles which, radiographically, showed some calcification. A diagnosis of a parosseous sarcoma was made; biopsy, however, indicated a diagnosis of non-traumatic myositis ossificans. Since the histological appearances of active myositis may be vary difficult to distinguish from a juxtacortical sarcoma, a right brachial angiogram and scintiscan were obtained. The angiographic and scintigraphic findings were erroneously considered to suggest malignancy. Following delivery, the tumour was removed. Futher histology confirmed the diagnosis of localised, non-traumatic myositis ossificans. The value of radiology, biopsy, angiography and scintigraphy are discussed with reference to our experience.

[Asymmetric brain perfusion in the aged?]

Between 1971 and 1975 we performed 1580 dynamic perfusion studies in 1411 patients. The patients were admitted to the nuclear medicine department for brain scanning from the medical, neurological and neurosurgical departments as well as directly by private family physicians. For dynamic brain studies we used the scintillation camera (Searle Radiographics) and a bolus of 99mTc-pertechnetate intravenously injected. The polaroid frames were exposed at 4 second intervals The results of the dynamic brain study were divided into five categories: normal, moderately diminished perfusion of one hemisphere, severe perfusion defect of one hemisphere, focal or multifocal hypervascular areas ("hot areas") and stenosis or occlusion of the carotid artery. In 1009 cases we found a normal perfusion of the tracer material without any side difference between the brain hemispheres. In 68 patients with motoric hemisyndrome of the right side and in 89 patients with hemisyndrome of the left side we were able to demonstrate a diminished perfusion of the contralateral hemisphere. In 65 patients with confirmed primary or metastatic brain tumors we observed a perfusion deficiency in 39 cases and focal "hot" areas in 26 cases. In 24 epileptic patients we found asymmetrical perfusion of the brain. In 109 patients without any neurological signs or symptoms we registered a "false positive" dynamic perfusion study with an asymmetrical initial transition of the injected tracer material. The left hemisphere showed a diminished perfusion in 86 cases, the right in 23 cases. The asymmetrical brain perfusion was not observed in patients under the age of twenty years. The incidence of "false positive" dynamic brain studies was found to be dependent on the age of the investigeted patients with a maximum of asymmetrical brain perfusion scans in the age group between 61 and 70 years. At present time we are not able to explain the reason of the "false positive" results. Because of this reason the investigation will be continued together with the neurologists and radiologists to find out a possible correlation between our study, the EEG-curves and results of the morphological brain investigations such as pneumoencephalography or ACT-scans.

[The 57Co-excretion and absorption test in the diagnosis of iron deficiency anemia]

1971 Sorbie et al. described a simple 57Co-excretion test (16) as an aid in the diagnosis of iron deficiency anemia. The authors found that renal excretion of a tracer dosis of 0,5 muCi 57CoCl2 was significantly elevated in patients with iron deficiency anemia (31% of the administered dose in 24 hours' urine) as compared with the controls (18%). Between 1972-1974 we performed the 57Co-excretion test in 29 patients with different kind of anemia and in 10 healthy volunteers. The test was modified by measurement of the serum activity 1, 2, 3, 7, 11 and 24 hours after the oral administration of the test dosis. In all anemias as well as in the control group we found the maximum of serum activity three hours after the oral administration of the tracer. The three hours serum activity was elevated only in patients with iron deficiency anemia (5,53%/1 serum) as compared with the control group (1,92%/1) and renal, tumor and infectious anemia (1,20%/1). p less than 0,001. The 57Co excretion was moderately elevated in most of the patients with iron dificiency anemia (average 31,5% 57Co-activity in 24 hours' urine) in comparison to the healthy controls (average 25,30%). Contrary to the results obtained by Sorbie et al. we found a wide range of fluctuation of the Co-excretion test in each group of patients with a poor statistical significance of p greater than 0,005.

Asymmetrische Hirndurchblutung im Alter?

Between 1971 and 1975 we performed 1580 dynamic perfusion studies in 1411 patients. The patients were admitted to the nuclear medicine department for brain scanning from the medical, neurological and neurosurgical departments as well as directly by private family physicians.

For dynamic brain studies we used the scintillation camera (Searle Radiographics) and a bolus of 99mTc-pertechnetate intravenously injected. The polaroid frames were exposed at 4 second intervals

The results of the dynamic brain study were divided into five categories: normal, moderately diminished perfusion of one hemisphere, severe perfusion defect of one hemisphere, focal or multifocal hypervascular areas (“hot areas”) and stenosis or occlusion of the carotid artery.

In 1009 cases we found a normal perfusion of the tracer material without any side difference between the brain hemispheres.

In 68 patients with motoric hemisyndrome of the right side and in 89 patients with hemisyndrome of the left side we were able to demonstrate a diminished perfusion of the contralateral hemisphere.

In 65 patients with confirmed primary or metastatic brain tumors we observed a perfusion deficiency in 39 cases and focal “hot” areas in 26 cases.

In 24 epileptic patients we found asymmetrical perfusion of the brain.

In 109 patients without any neurological signs or symptoms we registered a “false positive” dynamic perfusion study with an asymmetrical initial transition of the injected tracer material.

The left hemisphere showed a diminished perfusion in 86 cases, the right in 23 cases.

The asymmetrical brain perfusion was not observed in patients under the age of twenty years.

The incidence of “false positive” dynamic brain studies was found to be dependent on the age of the investigeted patients with a maximum of asymmetrical brain perfusion scans in the age group between 61 and 70 years.

At present time we are not able to explain the reason of the “false positive” results. Because of this reason the investigation will be continued together with the neurologists and radiologists to find out a possible correlation between our study, the EEG-curves and results of the morphological brain investigations such as pneumoencephalography or ACT-scans.

Der 57Co-Exkretions- und Resorptionstest in der Diagnose der Eisenmangelanämie

Im Jahre 1971 beschrieben Sorbie und Mitarbeiter (16) den 57Co-Exkretionstest als eine einfache und zuverlässige Methode in der Diagnose der Eisenmangelanämie. Nach oraler Applikation von 0,5 μCi 57Co (20 μmol CoCl2) fanden die Autoren eine renale Ausscheidung der Testdosis von 31% im 24-Stunden-Urin bei Eisenmangelanämien gegenüber 18% bei gesunden Kontrollpersonen.

In den Jahren 1972—1974 führten wir diesen Test bei 29 Patientinnen und Patienten mit verschiedenen Anämien sowie bei 10 gesunden Kontrollpersonen durch. Neben der renalen Ausscheidung von 57Cobalt haben wir zusätzlich die Serumaktivität 1, 2, 3, 7, 11 und 24 Stunden nach der Applikation der Testdosis gemessen. Sowohl bei den gesunden Kontrollpersonen als auch bei allen Anämieformen fanden wir das Aktivitätsmaximum im Serum 3 Stunden p.c., danach nahm die Aktivität langsam ab. Die 3-Stunden-Serumaktivität (57Co-Resorptionstest) war bei den Patienten mit einer Eisenmangelanämie mit durchschnittlich 5,53 %/L Serum gegenüber der Kontrollgruppe (1,92 %/L) signifikant erhöht (p < 0,01). Auch bei den renalen, Tumor- und Infektanämien konnten wir eine „normale” 3-Stunden-Serum-aktivität von durchschnittlich 1,20 %/L feststellen (p < 0,01).

Im Gegensatz zu den Resultaten von Sorbie und Mitarbeiter erwies sich die Messung der 57Co-Ausschei-dung im 24-Stunden-Urin als ein wenig zuverlässiger Test. Bei den Patienten mit einer Eisenmangelanämie konnten wir zwar eine leicht erhöhte renale Ausscheidung von 31,6 % der Dosis gegenüber 25,3 % bei gesunden Kontrollpersonen feststellen. Die Streubreite der einzelnen Meßwerte war jedoch hoch und die statistische Signifikanz der Eisenmangelanämie gegenüber der gesunden Kontrollgruppe mit p > 0,05 schlecht.

[The radionuclide hepato-angiography in the clinical diagnosis (author's transl)]

In 156 patients the dynamic liver perfusion study with 99mTc-sulfur colloid and the scintillation camera was performed. Out of the 81 cases with confirmed diagnosis, the rapid sequential liver study was only in one case to provide an additional information of clinical importance, which could not be demonstrated by static liver imaging. Except for 2 patients with carcinoid metastases of the liver and 3 cases of acute hepatitis, we did not find any significant difference in the activity appearance in the liver between normal subjects and patients with liver metastases and diffuse liver diseases.

[The place of isotope scanning in the diagnosis of pancreatic diseases (author's transl)]

259 isotope scans of the pancreas, done between 1966 and 1973, were analysed. In 62 cases the results of operation or necropsy findings were also available. In 43 of these 62 patients the scans could be diagnostically evaluated, the others being "negative". Among the 43, agreement with operative or necroptic findings existed in 35. All the malignant pancreatic tumours diagnosed by scanning were no longer operable. The place of isotope scanning is seen in general pancreatic diagnosis, especially on careful combination with clinical, special radiological and biochemical studies.

[A proposal to improve radioactive waste disposal following metabolic radio-iodine therapy]

After metabolic radio-iodine treatments of carcinomas of the thyroid, increased activities of I 131 are secreted from the patient's body by the renal route. The highly radioactive urine represents a serious danger of contamination for the nursing staff and third persons. The ideal conditions for the isolation of treated patients in a department disposing of a sewage disposal system of its own are not fulfilled at our hospital. Collection of radioactive urine of the patients for the purpose of annihilating radioactivity over several half-lifes of I 131 is extremely intricate. For this reason, we developed a filter system by means of which we were able to free the radioactive urine of the first five female patients treated from more than 99% of radioactivity. The contaminated locked filter patterns can be stored as "closed radio-sources" essentially more securely and space saving. The advantages of this system and their practical possibilities of use are discussed.

[Detection of thyreogenic osteopathy with the aid of the modern photon absorption technic]

163 male and female patients with confirmed metabolic status of the thyroid have been investigated with the aid of the 125-J photon absorption technique ("Bone Analyzer"). In the normothyroid group pathologically low values were found in 14.6 percent of cases. Findings which fell below a standard deviation of the normal range were regarded as pathologic. In 42 male and female patients with confirmed thyroid hyperfunction and decompensated autonomous adenomas, mineral content measurements in the radius revealed pathological values in 28.5 percent.

Displacement of anterior cerebral vessels in cerebral dynamic study in cases of chronic subdural hematomas

About 75-80% chronic subdural hematomas give positive results in a brain scan. The typical scintigraphic finding of chronic subdural hematoma is a diffuse widening and increase of the peripheral activity on the anterior view. In the flow studies subdural hematomas lead occasionally to peripheral activity defects. In two cases of chronic subdural hematoma without typical patterns in a perfusion study as well as in static images, we found a displacement of the anterior cerebral vessels as an indircet sign of space occupation.

Die Leistungsfähigkeit der Leberszintigraphie

Mit Hilfe eines Keilphantoms wurde die szintigraphische Nachweismöglichkeit verschieden großer und unterschiedlich gelegener Speicherdefekte untersucht. Bei ungünstiger Lage sind Aussparungen bis 55 mm Durchmesser schlecht erkennbar. Die Aufnahmen mit der Szintillationskamera und 99mTc waren der konventionellen Szintigraphie mit beweglichem Detektor überlegen.

Die Treffsicherheit der klinischen Leberszintigraphie liegt zwischen 80—90%.

Der Einfluß von pH auf das freie Serum-Thyroxin und seine physiologische Bedeutung

Das freie, biochemisch wirksame Serum-Thyroxin bleibt im dynamischen Gleichgewicht mit dem proteingebundenen Thyroxin, welches als Reservoir wirkt. Der Thyroxin-Spiegel im Blut bleibt konstant unabhängig vom Tages/Nacht-Rhythmus, körperlichen und psychischen Belastungen. Meßbare Veränderungen des freien Serum-Thyroxins sowie der thyroxinbindenden Präalbumine konnten dagegen bei verschiedenen Stress-Situationen festgestellt werden.

Mittels Gleichgewichts-Dialyse (Equilibrium Dialysis) wird der Einfluß der Wasserstoffionenkonzentration auf die dialysierbare Thyroxin-Fraktion des Serums untersucht. Bei pH Verschiebung der Pufferlösung in saurer Richtung konnte eine Zunahme der dialysierbaren Thyroxin-Fraktion beobachtet werden.

Die elektrophoretischen Untersuchungen im Veronal-Natrium-Puffer pH 8,6 und 7,0 zeigten eine nicht signifikante Zunahme der Thyroxin-Bindung durch die Albumin-Fraktion im pH 7,0.

Die beobachteten Auswirkungen der Wasserstoffionenkonzentration auf die thyroxinbindenden Proteine des Serums und das freie Serum-Thyroxin stimmen überein mit den Literaturangaben.

Die Zusammenhänge zwischen dem pH des Serums, der Bindungskapazität der thyroxinbindenden Proteine sowie dem freien Serum-Thyroxin deuten auf eine physiologisch-regulatorische Rolle der Wasserstoffionenkonzentration.