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R Linke

Publications and source records attributed to R Linke.

At least 19 recordsLinked to original sources
PubMed2007

Perfusion MRI before and after acetazolamide administration for assessment of cerebrovascular reserve capacity in patients with symptomatic internal carotid artery (ICA) occlusion: comparison with 99mTc-ECD SPECT.

INTRODUCTION: Impaired cerebral vascular reserve (CVR) in patients with symptomatic internal carotid artery (ICA) occlusion is regarded as a possible indication for performing extra-/intracranial (EC/IC) bypass surgery. As perfusion MR imaging (MRI) can demonstrate cerebral haemodynamics at capillary level, our hypothesis was that perfusion MRI could be used in these patients for the evaluation of CVR following acetazolamide challenge in a similar way to single photon emission CT (SPECT) and might provide additional information. METHODS: Enrolled in the study were 12 patients (mean age 61.3 years; 11 male, 1 female) with symptomatic unilateral ICA occlusion proven by angiography. Both perfusion MRI and 99m-technetium-ethyl-cysteinate dimer ((99m)Tc-ECD) SPECT were performed before and after injection of acetazolamide (Diamox ,1000 mg i.v.). CVR parameters including regional cerebral blood flow (rCBF) and volume (rCBV), and mean transit times (MTT) were measured by perfusion MRI. RESULTS: The patients with impaired CVR proven by SPECT (n = 9) had a negative mean rCBF increment (-46.52%), negative rCBV increment (-13.5%) and delayed MTT (mean +2.98 s), respectively, on the occluded side (Student's t-test all P < 0.05). The patients with sufficient CVR (n = 3) had a mean rCBF increment of 1.2%, a decrement of rCBV of 10.46%, and a mean MTT shortening of 0.27 s following the acetazolamide injection. CONCLUSIONS: Perfusion MRI before and after acetazolamide administration compares favourably with (99m)Tc-ECD SPECT for the detection of impaired CVR. The impact that perfusion MRI studies (before and after acetazolamide administration) might have on the treatment decision in patients with ICA occlusion has yet to be determined by a prospective study.

Acetazolamide↗
PubMed2006

Lymphoscintigraphy in penile cancer: limited value of sentinel node biopsy in patients with clinically suspicious lymph nodes.

The staging lymph node dissection in patients with penile carcinoma is accompanied with a high morbidity. As many patients are free of nodal metastases the lymphoscintigraphic sentinel node biopsy is supposed to minimize perioperative morbidity in these patients. In the current study the accuracy of the lymphoscintigraphic sentinel node biopsy was verified against the gold standard of radical inguinal dissection. In particular, patients with enlarged lymph nodes have also been included since one half of these patients is known to have histologically negative lymph nodes. Between 2000 and 2004 fifteen patients with penile carcinoma were elected to undergo bilateral groin dissection, thus 30 inguinal areas have been dissected. Nine patients have had clinically palpable nodes. All patients underwent lymphoscintigraphy after injection of Tc99-nanocolloid subcutaneously into the peritumoral area. Intraoperatively the sentinel nodes were identified with the aid of a gamma ray detection probe and excised. Afterwards a standard groin dissection was performed and the different lymph nodes were histopathologically assessed separately. In all patients lymph nodes with high radioactivity uptake were detected bilaterally. In 10 out of 30 inguinal areas histopathologically positive lymph nodes were present. In four of them the sentinel node was positive for tumor but in six dissection areas lymph node metastases were found despite a negative sentinel node. These patients had clinically palpable lymph nodes in their histologically positive inguinal regions. If no palpable nodes were present dynamic sentinel biopsy detected the positive nodes. The current study showed that dynamic sentinel node biopsy in patients with clinically suspicious lymph nodes is of low value for detection of lymphatic spread in penile cancer. Therefore the gold standard in these patients remains the radical groin dissection. However, dynamic sentinel node biospy is still a promising strategy to identify lymphatic spreading in clinically N0 patients and therefore to prevent unnecessary groin dissection.

Adult↗
PubMed2005

[Injection of botulinum toxin for diffuse esophageal spasm].

HISTORY AND ADMISSION FINDINGS: A 67-year-old man complained of recurrent retrosternal pain for 3 - 5 minutes as the only symptom for 3 - 4 years. Only when dysphagia occurred in the course of the disease was a gastroenterologist consulted. INVESTIGATIONS: The diagnosis of diffuse esophageal spasm was confirmed by esophageal manometry and radiology. Upper gastrointestinal endoscopy revealed no further pathological findings. TREATMENT AND COURSE: 100 units of botulinum toxin were injected in 10 divided doses, into the tubular esophagus, 1 cm apart, beginning at the z-line of the gastroesophageal junction, deeply into the muscular coat of the posterior part of the esophageal wall. This achieved improvement of symptoms as well as esophageal transit time measured by scintigraphy. The symptomatic benefit has now lasted for several months. CONCLUSION: The treatment of patients with diffuse esophageal spasm with botulinum toxin is a promising therapeutic option, which can be safely performed in such patients. But this regime needs evaluation in controlled prospective clinical studies.

Aged↗
PubMed2005

Separate sets of neurons of the central nucleus of the amygdala project to the substantia innominata and the caudal pontine reticular nucleus in the rat.

The central nucleus of the amygdala (CeA) is generally regarded as a control nucleus of subcortical target systems. Due to its widespread projections to different brain areas it is able to modulate emotional behavior of the organism. However, it is still not clear whether single neurons of the CeA project to different areas or to one target area. Injections of the retrograde tracers Fluorogold and True Blue into target regions of the central nucleus of the amygdala, i.e., the substantia innominata (SI) and the caudal pontine reticular nucleus (PNC), revealed overlapping but otherwise distinct neuronal populations within mainly the medial division of the CeA. From our study we conclude that SI and PNC receive input from different subsets of amygdala neurons.

Amygdala↗
PubMed2005

Is normal gastric emptying a predictor of normal gastric function?

AIM: Impaired gastric emptying is common in many disorders. Assuming that gastric disorders primarily affect gastric peristalsis, which secondarily results in impaired emptying, the aim of our study was to evaluate whether quantitative analysis of gastric peristalsis might be a more sensitive parameter than gastric emptying to demonstrate functional gastric impairment. PATIENTS, METHODS: Gastric emptying was determined scintigraphically in 141 adult (age: 18-78 years) patients (long-term Type 1 diabetes mellitus, 82 cases; systemic sclerosis, 31 cases; atrophic gastritis, 28 cases) and 20 healthy age-matched controls after ingestion of a semiliquid test meal. In addition, gastric peristalsis was evaluated by Fourier analysis of condensed images. RESULTS: Compared to the control persons emptying was delayed in 75/141 patients, regular in 63/141 patients, and accelerated in 3/141 patients. As expected, 81% of patients with delayed emptying presented with diminished gastric contraction amplitudes. However, independent of the aetiology of the underlying disorder, 40/63 patients with regular emptying also exhibited reduced peristalsis. CONCLUSION: Normal gastric emptying does not predict normal gastric function. This assumption is supported by the presence of reduced amplitudes in subgroups of patients with various disorders and normal emptying. Our results suggest that the amplitude of gastric contractions may represent a more sensitive parameter for the detection of gastric dysfunction than does gastric emptying.

Adolescent↗
PubMed2004

Axonal connections from posterior paralaminar thalamic neurons to basomedial amygdaloid projection neurons to the lateral entorhinal cortex in rats.

Stimulation of amygdaloid nuclei and emotionally relevant stimuli are known to influence the induction and maintenance of long-term potentiation in the hippocampal formation and the formation of long-term declarative memories. Because the thalamic projection from the posterior paralaminar thalamic nuclei is an important sensory afferent projection to amygdaloid nuclei mediating the fast acquisition of fear-potentiated behavior, we were interested in verifying whether this projection establishes synaptic contacts on amygdala neurons that project to the hippocampal formation. Thalamic afferents were labeled with the anterograde tracer Phaseolus vulgaris leucoagglutinin and amygdalo-hippocampal neurons were identified by injection of the retrograde tracer Fluorogold into the lateral entorhinal cortex. A massive overlap of both projection systems was observed especially in the anterior basomedial nucleus of the amygdala. Light microscopic examination revealed that single anterogradely labeled boutons were in close apposition to retrogradely labeled neurons suggesting synaptic contacts. The occurrence of such synaptic contacts was confirmed with electron microscopy. However, despite the massive overlap of anterogradely labeled axons and retrogradely labeled neurons observed at the light microscopic level, electron microscopy revealed that only 10% of all labeled profiles make direct contacts on each other; anterogradely labeled boutons predominantly contacted unlabeled profiles but synapses with direct contact between labeled profiles were rare. Altogether the findings demonstrate that the thalamic connection with the basomedial nucleus of the amygdala may represent an anatomical substrate for modulating amygdala output to the hippocampal formation.

Amygdala↗
PubMed2004

Two Wistar rat lines selectively bred for anxiety-related behavior show opposite reactions in elevated plus maze and fear-sensitized acoustic startle tests.

Two Wistar rat lines selectively bred for high (HAB), and low anxiety-related behavior (LAB) on the elevated plus maze were tested for the fear-sensitized acoustic startle response. The study of male rats from the F9 generation revealed a higher anxiety level of HAB rats on the elevated plus maze. However, the LAB rats displayed a higher baseline and fear-sensitized acoustic startle response compared to HAB rats, although the two rat lines did not differ in freezing duration during the interstimulus intervals in the startle experiment (neither before, nor after, footshocks). Counts of neurons immunoreactive for corticotropin-releasing factor and neuropeptide Y in amygdaloid nuclei did not reveal any differences between the two lines, which is in marked contrast to findings in the Roman rat lines. The data indicate that opposite types of anxiety/fear responses are elicited in HAB/LAB rats in the elevated plus maze and fear-sensitized startle tests. Moreover, the animals displayed a differential fear response in the startle experiment, as assessed by measuring the fear-sensitized startle response and freezing.

Acoustic Stimulation↗
PubMed2003

Fluorescence diagnosis: a novel method to guide radical inguinal lymph node dissection in penile cancer.

In penile cancer there is still a diagnostic dilemma between over treatment of lymph node-negative patients and the missing of occult metastases by watchful waiting. In the current study the value of fluorescence diagnosis during radical inguinal lymph node dissection was evaluated. Five patients with penile cancer were elected to undergo groin dissection. All patients received 5-aminolevulinic acid (5-ALA) orally before the operation for fluorescence diagnosis. Intraoperatively, fluorescence detection of the lymph nodes was performed by visual detection and spectroscopy. Two of the five patients had positive inguinal lymph nodes. Fluorescence in tumor-bearing tissue was detectable in the exposed lymph nodes. Protoporphyrin IX (PPIX) is accumulated in tumor-positive lymph nodes, making fluorescence diagnosis in penile cancer possible. More studies with higher patient numbers are necessary to evaluate optimal dosage and excitation conditions to detect tumor-bearing nodes in vivo.

Fluorescence↗
PubMed2003

Alteration of the striatal dopaminergic system in human narcolepsy.

Striatal D2/D3 dopaminergic receptors have been proposed to play a role in cataplexy. The authors studied the striatal presynaptic dopamine transporter and postsynaptic D2-receptors in seven patients with narcolepsy and seven control subjects using [123I](N)-(3-iodopropene-2-yl)-2beta-carbomethoxy-3beta-(4-chlorophenyl)tropane and [123I](S)-2-hydroxy-3-iodo-6-methoxy-([1-ethyl-2-pyrrolidinyl]methyl)benzamide SPECT. D2-receptor binding was elevated in narcolepsy (p = 0.017) and correlated with the frequency of cataplectic and sleep attacks (R > or = 0.844, p < or = 0.017). The human striatal dopaminergic system is altered in vivo in narcolepsy/cataplexy.

Aged↗
PubMed2003

[Thyroid gland ultrasound screening (Papillon Initiative). Report of 15 incidentally detected thyroid cancers].

In the framework of the Thyroid initiative Papillon 2001 - 2002 thyroid nodules and sonographically detectable focal lesions with a diameter more than 5 mm were verified in 23.1% of 64.123 persons without a history of thyroid disease. The frequency of such findings was with 33.0% in 46-65 years old persons three times higher then in persons aged 18-30 years (9.6%). In the diagnostic workup thyroid cancer was detected in 15 patients operated on up to now (6 women and 9 men; papillary cancers in 12 cases, follicular cancers in 3 cases) The smallest tumor had a diameter of 1.3 cm, the mean diameter was 2.3 +/- 91 cm. In 3 patients the tumor had invaded the tissue beyond the thyroid capsule, in 4 cases multicentric growth was detected. Lymph node metastases were found in 7/15 cases and distant metastases in 2/15 cases. These result reveal, that thyroid cancer detected by chance may be relatively aggressive. In daily routine, sonographically detectable lesions with poor echogenicity, irregular margins or internal calcifications with a diameter of more than 1 cm should be clarified by fine needle aspiration biopsy.

Adolescent↗
PubMed2003

[Subjective assessment of acute tinnitus and proposal of a tinnitus score].

BACKGROUND: Frequency, loudness and the level for masking of tinnitus of many patients can be measured. The measured parameters and the subjective feelings of the patients often do not correlate. METHODS: In a prospective study the subjective experiences of symptoms of 34 in-patients with acute tinnitus without hearing loss were analysed. The patients were asked before, during, immediately after and 3 years after therapy to fill in a form each. 4 questions allowed to assume the complaints to categories, 4 times the patients were asked to mark the intensity of their complaints on horizontal visual analogue scales. Each question scored from 0 to 5 points, a total score from 0 to 40 is possible. RESULTS: The therapy improved all parameters, the score improved from 23.0 to 14.7. The introduced questionnaire and the score allow a detailed documentation of the success of the treatment and with it the possibility to compare various approaches of therapy.

Acute Disease↗
PubMed2003

Breast cancer: monitoring response to neoadjuvant chemotherapy using Tc-99m sestamibi scintimammography.

BACKGROUND: Aim of the study was to assess the value of scintimammography using Tc-99m sestamibi in the evaluation of tumor response to neoadjuvant chemotherapy. MATERIAL ANS METHODS: Results were calculated for 9 patients undergoing neoadjuvant chemotherapy. Scintimammography using 740 MBq Tc-99m sestamibi was performed before, during and after chemotherapy, and sestamibi uptake was scored visually and semiquantitatively to evaluate tumor response. RESULTS: In the case of complete response (n = 3) sestamibi uptake decreased 8 days after beginning neoadjuvant chemotherapy and normalized in the following course. Focal uptake decreased more slowly in patients with partial response (n = 3), who showed clear, persisting tracer accumulation after therapy. The patients without response (n = 3) showed a persisting high tumor activity even after chemotherapy was completed. CONCLUSIONS: The preliminary data suggest that in contrast to other imaging modalities scintimammography appears to yield early information regarding tumor response to neoadjuvant chemotherapy.

Breast↗
PubMed2002

[Breast scintigraphy using 99mTc-sestamibi--use and limitations].

AIM: Until now scintimammography did not achieve any definite role in the assessment of breast lesions. Purpose of this study was to elaborate its use as well as the limitations of scintimammography after 500 examinations completed. METHODS: Scintigraphic findings were correlated with the histopathologic outcome of 219 patients, who underwent surgery or biopsy for histopathological confirmation. The results were determined with respect to palpability of the lesion and tumour size. Additionally, a distinct analysis was performed for the patient subpopulation with indeterminate results of previously performed physical examination, mammography, and sonography. RESULTS: Overall sensitivity for scintimammography was 82.1% at a specificity of 87.5%. For palpable lesions sensitivity was 91.7% which was evidently higher as compared to 64.9% for non palpable lesions. For palpable lesions specificity was 81.1% and 88.6% for non palpable lesions. According to tumour size sensitivity ranged between 65.2% for carcinoma with a diameter < 1 cm and 93.7% for carcinoma > 1 cm. In the patients subgroup with indeterminate preliminary diagnosis (n = 143) sensitivity decreased to 71.7% at a specificity of 87.8%. Patients undergoing neoadjuvant chemotherapy showed decreasing sestamibi uptake as early as 8 days after therapy if tumour response was evident. However, small residual invasive tumours in patients with complete remission could not be visualised. CONCLUSION: Scintimammography is neither suited for screening, nor early diagnosis of breast cancer, nor for the further evaluation of small and unclear mammographic findings. Scintimammography should not be used whenever histopathological clarification of a suspicious lesion is necessary. It is useful to further investigate patients with unclear or probably benign findings in physical examination and/or mammography and to monitor tumour response to neoadjuvant chemotherapy.

Breast↗
PubMed2001

Axonal connections of thalamic posterior paralaminar nuclei with amygdaloid projection neurons to the cholinergic basal forebrain in the rat.

Stimulation of the amygdala elicits cortical activation mediated by the corticopetal basal forebrain. An unresolved question is whether the involved amygdala neurons that project to the basal forebrain receive direct thalamic input. Using combined retrograde and anterograde tracing techniques, we demonstrate a monosynaptic contact between thalamic posterior paralaminar nuclei axons and neurons in the central amygdala that project to corticopetal cholinergic basal forebrain regions. These contacts may constitute the morphological substrate for the induction of fast cortical arousal and attention triggered by emotional events.

Amygdala↗
PubMed2001

Normal IPT and IBZM SPECT in drug-naive and levodopa-treated idiopathic restless legs syndrome.

Fourteen drug-naive and 11 levodopa-treated patients with idiopathic restless legs syndrome (RLS), and 10 controls age-matched to each RLS group separately were examined with polysomnography (PSG), [(123)I]-(N)-(3-iodopropen-2-yl)-2beta-carbomethoxy-3beta-(4-chlorophenyl) tropane ((123)I-IPT) SPECT, and [(123)I]-(S)-2-hydroxy-3-iodo-6-methoxy-[(1-ethyl-2-pyrrolidinyl)methyl] benzamide ((123)I-IBZM) SPECT. Drug-naive and levodopa-treated patients with RLS and controls showed similar striatal dopamine transporter and dopamine D(2)-receptor binding, the latter declining with age. The authors conclude that striatal dopamine transporter and receptor density is normal in drug-naive and levodopa-treated patients with RLS.

Aged↗
PubMed2001

18F-FDG PET and 99mTc-sestamibi scintimammography for monitoring breast cancer response to neoadjuvant chemotherapy: a comparative study.

Presurgical neoadjuvant chemotherapy has shown promise in the treatment of locally advanced breast carcinoma (LABC). Response assessment by clinical examination and mammography is difficult. This study evaluated and compared fluorine-18 fluorodeoxyglucose positron emission tomography (18F-FDG-PET) and technetium-99m sestamibi scintimammography (SMM) as potential methods for the early assessment of tumour response to neoadjuvant chemotherapy in patients with LABC. Seven patients underwent PET and SMM [planar and single-photon emission tomography (SPET)] before beginning chemotherapy, after the first and second cycles of chemotherapy and after completing chemotherapy prior to surgery. PET and SMM results were evaluated visually and semi-quantitatively by calculating standardised uptake values (SUV) and tumour/lung ratios in the initial and subsequent studies. The findings were correlated with the initial clinical and mammographic findings and the final histopathological diagnoses. There was a highly significant correlation between SUVmean, SUVmax and the tumour/lung ratio determined with SMM-SPET in the studies performed before and during neoadjuvant chemotherapy. All three patients with complete remission showed decreasing FDG and sestamibi uptake as early as 8 days after therapy. In the presurgical study, increased sestamibi and FDG uptake was no longer evident. Three patients had partial remission with clearly reduced but persisting focal FDG and sestamibi uptake after neoadjuvant therapy. One patient who did not respond to therapy had unchanged intense tracer uptake during chemotherapy that was evident with both techniques. An early decline in glucose metabolism or sestamibi uptake 8 days after beginning therapy did not necessarily predict complete tumour remission in the further course of chemotherapy. On the other hand, increased tracer uptake after the first cycle did not exclude a partial tumour response. After the second chemotherapeutic cycle both techniques were able to distinguish between complete and partial/no response. There was a good correlation between preoperative FDG and sestamibi uptake and the histopathologically determined tumour size. However, small residual invasive tumours in patients with clinically complete remission could not be visualised with either technique. The preliminary data demonstrate that sestamibi SMM is as useful as FDG-PET for the monitoring of tumour response to neoadjuvant chemotherapy.

Adult↗