A Novel Mutation of the Calcium Sensing Receptor Gene in a Franconian Kindred: Heterozygous Mutation c.1697_1698delTG Exon 6.

Familial hypocalciuric hypercalcemia (FHH) belongs to the disorders of a disturbed calcium homeostasis. Genetically, the disorder is inherited in an autosomal-dominant trait and represents an inactivating mutation of the calcium sensing receptor (CaSR) gene. We identified a Franconian kindred in which 6 individuals could be tested by molecular genetic means. In 5 individuals of 3 generations, the mutation could be classified as c.1697_1698delTG. This novel germline mutation creates a premature stop codon leading to a loss of 510 amino acids of the protein. The detection of CaSR gene mutations is suitable to differentiate states of hypercalcemia and may help to avoid invasive procedures such as parathyroidectomies.

Status-appropriate singing behavior, testosterone and androgen receptor immunolabeling in male European starlings (Sturnus vulgaris).

Vocalizations convey information about an individual's motivational, internal, and social status. As circumstances change, individuals respond by adjusting vocal behavior accordingly. In European starlings, a male that acquires a nest site socially dominates other males and dramatically increases courtship song. Although circulating testosterone is associated with social status and vocal production it is possible that steroid receptors fine-tune status-appropriate changes in behavior. Here we explored a possible role for androgen receptors. Male starlings that acquired nest sites produced high rates of courtship song. For a subset of males this occurred even in the absence of elevated circulating testosterone. Immunolabeling for androgen receptors (ARir) was highest in the medial preoptic nucleus (POM) in males with both a nest site and elevated testosterone. For HVC, ARir was higher in dominant males with high testosterone (males that sang longer songs) than dominant males with low testosterone (males that sang shorter songs). ARir in the dorsal medial portion of the nucleus intercollicularis (DM) was elevated in males with high testosterone irrespective of dominance status. Song bout length related positively to ARir in POM, HVC and DM, and testosterone concentrations related positively to ARir in POM and DM. Results suggest that the role of testosterone in vocal behavior differs across brain regions and support the hypothesis that testosterone in POM underlies motivation, testosterone in HVC relates to song quality, and testosterone in DM stimulates vocalizations. Our data also suggest that singing may influence AR independent of testosterone and that alternative androgen-independent pathways regulate status-appropriate singing behavior.

Three-dimensional Monte Carlo-based voxel-wise tumor dosimetry in patients with neuroendocrine tumors who underwent 177Lu-DOTATOC therapy.

BACKGROUND: Patients with advanced neuroendocrine tumors (NETs) of the midgut are suitable candidates for 177Lu-DOTATOC therapy. Integrated SPECT/CT systems have the potential to help improve the accuracy of patient-specific tumor dosimetry. Dose estimations to target organs are generally performed using the Medical Internal Radiation Dose scheme. We present a novel Monte Carlo-based voxel-wise dosimetry approach to determine organ- and tumor-specific total tumor doses (TTD). METHODS: A cohort of 14 patients with histologically confirmed metastasized NETs of the midgut (11 men, 3 women, 62.3 ± 11.0 years of age) underwent a total of 39 cycles of 177Lu-DOTATOC therapy (mean 2.8 cycles, SD ± 1 cycle). After the first cycle of therapy, regions of interest were defined manually on the SPECT/CT images for the kidneys, the spleen, and all 198 tracer-positive tumor lesions in the field of view. Four SPECT images, taken at 4 h, 24 h, 48 h and 72 h after injection of the radiopharmaceutical, were used to determine their effective half-lives in the structures of interest. The absorbed doses were calculated by a three-dimensional dosimetry method based on Monte Carlo simulations. TTD was calculated as the sum of all products of single tumor doses with single tumor volumes divided by the sum of all tumor volumes. RESULTS: The average dose values per cycle were 3.41 ± 1.28 Gy (1.91-6.22 Gy) for the kidneys, 4.40 ± 2.90 Gy (1.14-11.22 Gy) for the spleen, and 9.70 ± 8.96 Gy (1.47-39.49 Gy) for all 177Lu-DOTATOC-positive tumor lesions. Low- and intermediate-grade tumors (G 1-2) absorbed a higher TTD compared to high-grade tumors (G 3) (signed-rank test, p = < 0.05). The pre-therapeutic chromogranin A (CgA) value and the TTD correlated significantly (Pearson correlation: = 0.67, p = 0.01). Higher TTD resulted in a significant decrease of CgA after therapy. CONCLUSION: These results suggest that Monte Carlo-based voxel-wise dosimetry is a very promising tool for predicting the absorbed TTD based on histological and clinical parameters.

Evolution of a protein fold in vitro.

A "switch" mutant of the Arc repressor homodimer was constructed by interchanging the sequence positions of a hydrophobic core residue, leucine 12, and an adjacent surface polar residue, asparagine 11, in each strand of an intersubunit beta sheet. The mutant protein adopts a fold in which each beta strand is replaced by a right-handed helix and side chains in this region undergo significant repacking. The observed structural changes allow the protein to maintain solvent exposure of polar side chains and optimal burial of hydrophobic side chains. These results suggest that new protein folds can evolve from existing folds without drastic or large-scale mutagenesis.

Sequence space, folding and protein design.

Protein design efforts are beginning to yield molecules with many of the properties of natural proteins. Such experiments are informed by and contribute to our understanding of the sequence determinants of protein folding and stability. The most important design elements seem to be the proper placement of hydrophobic residues along the polypeptide chain and the ability of these residues to form a well packed core. Buried polar interactions, turn and capping motifs and secondary structural propensities also contribute, although probably to a lesser extent.

Sexually-motivated song is predicted by androgen-and opioid-related gene expression in the medial preoptic nucleus of male European starlings (Sturnus vulgaris).

Across vertebrates, communication conveys information about an individual's motivational state, yet little is known about the neuroendocrine regulation of motivational aspects of communication. For seasonally breeding songbirds, increases in testosterone in spring stimulate high rates of sexually-motivated courtship song, though not all birds sing at high rates. It is generally assumed that testosterone or its metabolites act within the medial preoptic nucleus (POM) to stimulate the motivation to sing. In addition to androgen receptors (ARs) and testosterone, opioid neuropeptides in the POM influence sexually-motivated song production, and it has been proposed that testosterone may in part regulate song by modifying opioid systems. To gain insight into a possible role for androgen-opioid interactions in the regulation of communication we examined associations between sexually-motivated song and relative expression of ARs, mu opioid receptors (muORs), and preproenkephalin (PENK) in the POM (and other regions) of male European starlings using qPCR. Both AR and PENK expression in POM correlated positively with singing behavior, whereas muOR in POM correlated negatively with song. Furthermore, the ratio of PENK/muOR expression correlated negatively with AR expression in POM. Finally, in the ventral tegmental area (VTA), PENK expression correlated negatively with singing behavior. Results support the hypothesis that ARs may alter opioid gene expression in POM to fine-tune singing to reflect a male's motivational state. Data also suggest that bidirectional relationships may exist between opioids and ARs in POM and song, and additionally support a role for opioids in the VTA, independent of AR activity in this region.

Differential relationships between D1 and D2 dopamine receptor expression in the medial preoptic nucleus and sexually-motivated song in male European starlings (Sturnus vulgaris).

Converging data in songbirds support a central role for the medial preoptic nucleus (POM) in motivational aspects of vocal production. Recent data suggest that dopamine in the POM plays a complex modulatory role in the production of sexually-motivated song and that an optimal level of dopamine D1 receptor stimulation is required to facilitate singing behavior. To further explore this possibility, we used quantitative real-time PCR to examine relationships between mRNA expression of D1 as well as D2 receptors in the POM (and also the lateral septum and Area X) and sexually-motivated singing behavior in male European starlings. Results showed that both males with the highest and lowest D1 expression in the POM sang significantly less than males with intermediate levels of expression. Furthermore, singing behavior rose linearly in association with increasing levels of D1 expression in POM but dropped abruptly, such that individuals with D1 expression values higher than the mean sang very little. Analysis of birds with low and intermediate levels of D1 expression in POM revealed strong positive correlations between D1 expression and song but negative relationships between D2 receptor expression and song. These findings support prior work suggesting an optimal level of POM D1 receptor stimulation best facilitates sexually-motivated singing behavior. Results also suggest that D2 receptors may work in opposition to D1 receptors in POM to modify vocal production.

Tolerance of a protein to multiple polar-to-hydrophobic surface substitutions.

Hydrophobic substitutions at solvent-exposed positions in two alpha-helical regions of the bacteriophage P22 Arc repressor were introduced by combinatorial mutagenesis. In helix A, hydrophobic residues were tolerated individually at each of the five positions examined, but multiple substitutions were poorly tolerated as shown by the finding that mutants with more than two additional hydrophobic residues were biologically inactive. Several inactive helix A variants were purified and found to have reduced thermal stability relative to wild-type Arc, with a rough correlation between the number of polar-to-hydrophobic substitutions and the magnitude of the stability defect. Quite different results were obtained in helix B, where variants with as many as five polar-to-hydrophobic substitutions were found to be biologically active and one variant with three hydrophobic substitutions had a t(m) 6 degrees C higher than wild-type. By contrast, a helix A mutant with three similar polar-to-hydrophobic substitutions was 23 degrees C less stable than wild-type. Also, one set of three polar-to-hydrophobic substitutions in helix B was tolerated when introduced into the wild-type background but not when introduced into an equally active mutant having a nearly identical structure. Context effects occur both when comparing different regions of the same protein and when comparing the same region in two different homologues.

Iodine-123-iodo-lisuride SPECT in Parkinson's disease.

UNLABELLED: Recently, [123I]iodo-lisuride was synthesized for possible applications in SPECT studies. The purpose of this investigation was to compare the striatal binding and kinetics of this radioligand in patients with Parkinson's disease and normal controls. METHODS: Six patients with Parkinson's disease and three normal controls were examined. After intravenous injection of 111 MBq [123I]iodo-lisuride, sequential SPECT examinations at 20, 40, 80 and 120 min were performed. For each SPECT series the basal ganglia-to-cerebellum ratio of tracer accumulation was calculated. In one patient a repeat SPECT examination was undertaken under identical conditions to test the reproducibility of the procedure. In two other patients a second SPECT examination was performed after injection of cold lisuride as a receptor saturation study. In addition, the time course of the radioactivity was measured in the plasma and red blood cells in each individual. RESULTS: In both patients and controls, the highest tracer accumulation was found within the striatum. The basal ganglia-to-cerebellum ratio was 1.182 and 1.303 at 20 min, 1.353 and 1.450 at 40 min, 1.490 and 1.533 at 80 min, 1.550 and 1.583 at 120 min for patients and controls, respectively, which was not statistically different. In the saturation study, 50 micrograms and 100 micrograms cold lisuride led to a 28% and 33% reduction, respectively, of the basal ganglia-to-cerebellum ratio at 120 min. The ligand showed a rapid decline in plasma and red blood cells. The percent injected dose per liter was calculated to be 1.6 and 0.9, respectively, for plasma and red blood cells at 20 min. CONCLUSION: Iodine-123-iodo-lisuride SPECT seems useful for imaging intact striatal dopamine D2 receptors in patients with Parkinson's disease and may provide clinically relevant information for quantitative assessment of the availability and integrity of dopamine D2 receptors.

Dopamine D2 receptor imaging with iodine-123-iodobenzamide SPECT in idiopathic rotational torticollis.

UNLABELLED: The cause of idiopathic rotational torticollis (IRT) is not completely understood to date. However, basal ganglia are believed to be involved in the pathophysiology of IRT. To elucidate this disorder further, the value of iodobenzamide (IBZM) SPECT was studied for the evaluation of striatal dopamine D2 receptors in these patients. METHODS: Striatal dopamine D2 receptor density was assessed in 10 patients with IRT using 123I-IBZM SPECT. The images were interpreted by a nuclear medicine physician initially to determine IBZM binding within the striatum and the cerebellum and, secondly, interstriatal IBZM binding. The results were correlated with the clinical parameters of the patients and compared with the results obtained from normal controls. RESULTS: No difference was found in average, specific striatal IBZM binding (basal ganglia/cerebellum ratio) between patients and controls. However, interstriatal analysis of IBZM binding revealed a significantly higher binding in the striatum contralateral to the direction of the torticollis (p = 0.026, by chi-square test). CONCLUSION: It was concluded that the striatal dopamine D2 receptor status is altered in patients with IRT.

Loss of dopamine-D2 receptor binding sites in Parkinsonian plus syndromes.

UNLABELLED: This study analyzed temporal changes of striatal dopamine-D2 receptor binding during the course of different extrapyramidal movement disorders using 123I-iodobenzamide (IBZM) SPECT. METHODS: Eighteen patients (9 with Parkinson's disease, 9 with parkinsonian plus syndrome) were followed for 11-53 mo. Dopamine-D2 receptor binding was assessed using 123I-IBZM SPECT at the beginning and at the end of the follow-up period. SPECT data were acquired 120 min postinjection of 3-5 mCi 123I-IBZM. A semiautomated algorithm was applied to the raw data for semiquantitative evaluation of regional cerebral receptor binding. RESULTS: Intraobserver (r = 0.992) and interobserver (r = 0.930) variance was low for the semiautomated interpretation of the SPECT examination of the dopaminergic D2 receptor binding, reflecting a highly reproducible SPECT algorithm. Mean specific dopamine-D2 receptor binding was lower in patients with parkinsonian plus syndrome compared to patients with Parkinson's disease on the initial (p < 0.001) as well as the follow-up study (p < 0.001). In patients with Parkinson's disease, we observed an unaffected receptor binding compared to a reduced binding of radiotracer in patients with parkinsonian plus syndrome during the course of the disease (p < 0.001). CONCLUSION: During the follow-up, patients with Parkinson's disease showed a constant dopamine-D2 receptor binding. In contrast, patients with parkinsonian plus syndrome revealed a decline of the binding of dopamine-D2 receptor. These findings are in agreement with histopathological data that demonstrated a preserved dopamine-D2 receptor status in patients with Parkinson's disease and a decline of the dopamine-D2 receptors in patients with parkinsonian plus syndrome. SPECT examinations using 123I-IBZM are useful for assessing dynamic changes of dopamine-D2 receptors in extrapyramidal movement disorders. Semiquantitative SPECT evaluations may provide valuable information for clinical management and prognosis of the patient with extrapyramidal movement disorders.

Evaluation of focal epilepsy: a SPECT scanning comparison of 123-I-iomazenil versus HM-PAO.

PURPOSE: To establish whether regional disturbances of the benzodiazepine receptor distribution in focal epilepsies can be detected by SPECT using 123-I-Iomazenil. PATIENTS AND METHODS: Benzodiazepine receptor imaging was carried out in 10 patients interictally. To be eligible for this study the patients had to have a history of focal seizures and no evidence of routine imaging abnormalities as in CT or MR. The patients were selected on the basis of a regional decreased blood flow in HMPAO SPECT that correlated with the site of a stable unifocal EEG abnormality. Benzodiazepine receptor imaging was performed after intravenous administration of approximately 110 MBq 123-I-Iomazenil using SPECT. RESULTS: A regional reduced activity was found on sequential SPECT series after 30 and 90 min post injection in the receptor study. The brain region with a reduced receptor density was concordant to the pathologic finding in HMPAO SPECT in all patients. CONCLUSION: For the evaluation of patients with focal epilepsies lomazenil SPECT offers several advantages over HMPAO SPECT. Iomazenil binds specifically to the benzodiazepine receptor complex whereas the exact binding sites of HMPAO are still unknown. In contrast to HMPAO, lomazenil can be used for sequential SPECT examinations that may detect dynamic changes of the receptor complex. For the purpose of benzodiazepine receptor imaging, lomazenil is a suitable ligand in patients with focal epilepsies.

Lissencephaly: diagnosis by computed tomography and magnetic resonance imaging.

A patient with Miller-Dieker-Syndrome, which is associated with lissencephaly, was examined by Computed Tomography (CT) and Magnetic Resonance Imaging (MRI). While CT demonstrated the main features of lissencephaly, MRI detected disturbed myelination and cell migration in the cerebral hemispheres and a normal appearance of the cerebellum. MRI provides more accurate information of the pathomorphologic changes of lissencephaly and is thus superior to CT.

Initial experience with SPECT examinations using [123I]IBZM as a D2-dopamine receptor antagonist in Parkinson's disease.

[123I]IBZM is a new radioactive labelled ligand which has a high affinity and specificity to D2-dopamine receptors. The in vivo kinetics of [123I]IBZM were studied in patients with unilateral and bilateral accentuated idiopathic Parkinson's disease. The uptake in the basal ganglias and the imaging properties of this D2 receptor antagonist as a radiopharmaceutical for SPECT examinations had to be investigated. 5 patients, aged 42-66 years, (2 m/3 f) were examined. Each patient received 185 MBq [123I]IBZM intravenously. Blood samples were taken 0-120 min post injection (p.i.) and time activity curves were plotted. Three SPECT examinations were performed (I: 30-50 min; II: 50-70 min; and III: 70-90 min p.i.). The count rates (counts/pixel) in the basal ganglias and the cerebellum were measured for each SPECT series on transverse slices using the region-of-interest technique. The time-activity curve of [123I]IBZM shows a rapid decline in plasma during the first 10 min followed by a plateau until 120 min after injection. The SPECT examinations demonstrate the highest count rate in the basal ganglia during SPECT series III (i.e., 70-90 min p.i.). The side-to-side difference of the count rates were in the range of 3% in four patients, and 10% in one patient. The biokinetic data of [123I]IBZM make this substance capable as a radiopharmaceutical for SPECT examinations. The basal ganglia are best visualized 70-90 min p.i., thus [123I]IBZM seems to be a promising imaging agent for diseases of the D2-dopaminergic receptor system.

[Transcranial Doppler sonography in cerebrovascular diseases]. / Transkranielle Doppler-Sonographie bei zerebrovaskulären Erkrankungen.

A review of our 1 1/2 years' experience with transcranial Doppler sonography (TCD) is given. In total, 619 TCD examinations were performed. Considering physiological variations of blood flow velocities in the intracranial arteries, TCD findings in stenoses and occlusions of the extracranial and intracranial brain-supplying arteries as well as in intracranial vasospasms were evaluated. In patients with leptomeningeal anastomoses demonstrated by TCD in the region of the peripheral middle cerebral artery, the regional cerebral blood flow was measured by 99mTc-HMPAO-SPECT. The value and limitations of TCD in cerebrovascular diseases and the indications to TCD examination of the intracranial arteries are discussed.

[Ischemic brain infarct: combined determination of regional cerebral blood flow and volume by SPECT]. / Ischämische Hirninfarkte: Die kombinierte Bestimmung von regionalem zerebralen Blutfluss und Volumen mittels SPECT.

A combined measurement of regional cerebral blood flow (r CBF) and volume (r CBV) by SPECT was performed in 15 patients with ischaemic cerebral infarction. For measurement of r CBF 99mTc-HMPAO was used, and for r CBV 99mTc-labelled red blood cells. Patients with acute or subacute cerebral infarction (n = 10) showed elevation of r CBV whereas r CBF was either reduced or elevated. Patients with chronic cerebral infarction (n = 5) showed reduction of both r CBF and r CBV. The combined measurement of both r CBF and r CBV by SPECT allows imaging and semiquantitative evaluation of haemodynamic changes in ischaemic cerebral infarction at various stages. The resulting data may be helpful in describing the pathophysiologic compensatory mechanisms.

[Prostatic cancer. Staging via transrectal prostatic sonography and computed tomography with histopathological correlation]. / Prostatakarzinom. Stadieneinteilung durch transrektale Prostatasonographie und Computertomographie mit histopathologischer Korrelation.

Pre-operative staging, using transrectal prostatic sonography and CT, was carried out in 30 patients with cytologically confirmed carcinomas of the prostate and the results compared with the clinical findings. All patients underwent radical prostatectomy and the pre-operative findings could be verified histologically. Transrectal prostatic sonography is better than CT or clinical examination for determining local tumour spread or penetration of the capsule. A high proportion of enlarged pelvic lymph-nodes shown by CT had non-specific changes; failure to demonstrate enlarged nodes excludes lymph node metastases with considerable certainty. Transrectal prostatic sonography provides a higher degree of information regarding local tumour spread, whereas CT indicates the presence or absence of lymph node metastases.

[The digital reprocessing of underexposed x-rays. Studies with a fluorescent light scanner]. / Digitale Nachbearbeitung von unterbelichteten Röntgenaufnahmen. Untersuchungen mit einem Fluoreszenzlichtscanner.

Incorrect exposure of conventional radiographs frequently leads to repetition of the examination and thereby to increased radiation exposure for the patient. Underexposed films of an Alderson-Rando phantom, an ankle joint and a patella were digitised by means of an inexpensive fluorescent light scanner, and subsequent image manipulation improved quality so as to make the image diagnostically adequate. For the demonstration of markedly underexposed structures digitalisation with subsequent contrast enhancement was used. Well exposed structures are best evaluated in contrast enhanced transmitted light. Our results suggest it should be possible to reduce the number of repeat exposures and thereby to limit radiation exposure.

[Duplex sonography in functional thyroid diagnosis]. / Die Duplexsonographie in der Schilddrüsenfunktionsdiagnostik.

PURPOSE: Assessment of the functional diagnostic value of Doppler sonographic or sonographic parameters, especially of the peak flow velocity in the inferior thyroid artery in patients with newly manifest autoimmunothyroiditis. MATERIAL AND METHOD: Morphological and Doppler sonographic measurements were done at the inferior thyroid artery on 69 patients suffering from newly manifest Graves' disease or Hashimoto's thyroiditis, as well as on a control group of 18 subjects. The measured data were correlated with thyroid hormone levels and with quantitative scintiscanning. RESULTS: A linear functional correlation was found between the peak flow velocities in the inferior thyroid artery and the fT3 or fT4 level. If the peak flow velocities were greater than 1.2 m/s, hyperthyroid metabolism prevailed, whereas at velocities below 0.3 m/s latent hypothyroidism was present. CONCLUSION: These results show that Doppler sonography of the inferior thyroid artery can supply pointers (capable of being recorded) to the state of functioning of the thyroid even before knowing the laboratory parameters.

[Osteoplastic bone metastases in prostatic carcinoma: magnetic resonance tomography and bone marrow scintigraphy]. / Osteoplastische Knochenmetastasen beim Prostatakarzinom: Magnetresonanztomographie und Knochenmarkszintigraphie.

MRI of the vertebral column was performed in 28 patients with histologically confirmed prostate carcinoma. Besides routine spin-echo sequences all patients were examined with gradient-echo sequences using the chemical shift mode. In addition, in all patients bone marrow scintigraphy (BMS) was performed, and all results were compared with routine bone scan (BS). In our study BMS was not superior to bone scan. In contrast, MRI scan revealed solitary metastases in two patients with negative BS and BMS. Osteoplastic metastases showed a contrast enhancement in the MRI and could be distinguished from benign alterations.