Increased urinary orosomucoid excretion is not related to impaired renal function in patients with type 2 diabetes

OBJECTIVES

Increased urinary orosomucoid excretion rate (UOER) independently predicted cardiovascular mortality in patients with type 2 diabetes at 5-years of follow-up. To further explore UOER in relation to local renal physiological phenomena, we studied renal glomerular and tubular functions in patients with type 2 diabetes and normal or increased UOER.

METHODS

We performed a cross-sectional study of 40 patients with type 2 diabetes (normal UOER, n=16; increased UOER, n=24) who displayed no signs of cardiovascular disease and 21 healthy control persons. The renal clearance values of [(51)Cr]ethylenediaminetetraacetic acid ([(51)Cr]EDTA), lithium, orosomucoid, albumin, and sodium were measured.

RESULTS

Patients with type 2 diabetes had normal glomerular filtration rate (GFR) measured by [(51)Cr]EDTA clearance. The clearance value of orosomucoid was highly increased in patients with increased UOER. The clearance values of albumin were similar in patients with increased UOER and in healthy controls. Investigations of renal tubular function revealed normal and similar levels of lithium clearance and proximal and distal reabsorption of sodium and water. Serum values of orosomucoid were higher in patients with increased UOER than in healthy controls (P<.001), but were still within reference limits, suggesting chronic low-grade inflammation. UOER was associated with increasing values of orosomucoid clearance (P<.0001) independently of serum orosomucoid.

CONCLUSIONS

Patients with type 2 diabetes and increased UOER had normal GFR and showed no signs of renal glomerular or tubular dysfunction. We therefore hypothesize that increased levels of UOER may be caused by local renal production of orosomucoid due to chronic low-grade inflammation.

Neuroimaging and clinical neurophysiology in cluster headache and trigeminal autonomic cephalalgias

Clinical neurophysiology and neuroimaging are two non-invasive approaches used to investigate the pathophysiological basis of primary headaches, including cluster headache (CH) and other trigeminal autonomic cephalalgias (TACs). Modern neuroimaging has revolutionized our understanding of the pathophysiology of primary headaches, and of TACs in particular, focusing on a cerebrovascular dysfunction hypothesis toward a central triggering cause. The introduction of single-photon emission computed tomography (SPECT), positron emission tomography (PET), and voxel-based morphometry has allowed us new insights into mechanisms underlying TACs and occurring during peripheral and/or central neuromodulation. The specific activation of neural structures that is observed exclusively in migraine and in TACs supports the hypothesis that primary headaches are driven predominantly by central nervous system dysfunction, and this has important implications from a therapeutic perspective. Neurophysiological examinations are of little value in the clinical setting; however, most of these tools offer vast potential for exploring further the pathophysiology of primary headaches and the effects of pharmacological treatments Trigeminofacial reflexes, the nociceptive flexion reflex, and evoked potentials have been used in TACs to explore the functional state of brainstem and spinal structures involved in pain processing, contributing to our understanding of the pathophysiology of these primary headaches.

Digoxin in atrial fibrillation: report from the Stockholm Cohort study of Atrial Fibrillation (SCAF)

BACKGROUND

Recent studies of patients with heart failure and of patients receiving intensive care indicate that digoxin may increase mortality if the patient has atrial fibrillation (AF). Objective To study which patients receive digoxin treatment for AF and what the prognosis is for patients given this treatment.

METHOD

2824 patients with AF were studied prospectively for a mean of 4.6 years. Information about medication was obtained from the local hospital registry. Information about diagnoses, hospitalisations and deaths was obtained from national registries. Propensity score matching and Cox regression was used to account for confounding.

RESULTS

Factors associated with digoxin use were permanent AF (hazard ratio (HR) = 3.2, confidence interval (CI) 2.7 to 3.9), absence of pacemaker (HR = 2.3, CI 1.6 to 3.2), history of heart failure (HR = 2.0, CI 1.7 to 2.5), treatment in an internal medicine ward rather than a cardiology ward (HR = 1.6, CI 1.3 to 2.0), female sex (HR = 1.6, CI 1.3 to 1.9) and age >or=80 years (HR = 1.4, CI 1.1 to 1.7). More patients with than without digoxin died (51% vs 31%, p<0.001). After adjustment for covariates, however, no disadvantages related to digoxin use could be found for all-cause mortality, myocardial infarction, ischaemic stroke, time to readmission to hospital or days at hospital/year at risk. The only end point significantly associated with digoxin use was pacemaker implantations, which were more common in digoxin-treated patients (HR = 2.0, CI 1.2 to 3.4).

CONCLUSION

Digoxin is mainly given to an elderly and frailer subset of patients with AF and is thus associated with an increased mortality. When differences in patient characteristics are accounted for digoxin use seems to have a neutral effect on mortality and major cardiovascular events in patients with AF.

A validation of cause-of-death certification in 1,156 deaths

Swedish twins have been followed for mortality since 1961, when the Swedish Twin Registry was formed. During the years 1961-73 there were 1290 deaths among twins born in 1901-25. In 1156 cases the cause of death could be established from collected records and classified according to the 1965 revision of ICD. Using the review of records as the standard, rates of detection and confirmation relating to the death certificate diagnoses were calculated. It is concluded that Swedish death certificate data are fairly valid for use in epidemiological studies and mortality statistics with regard to most cancer forms, cerebrovascular disease, ischemic heart disease, bronchitis, asthma and emphysema, accidents and suicides, but not for diabetes mellitus, alcoholism, mental diseases, rheumatic heart diseases and other heart diseases. However, in selected clinical-epidemiological studies it is often necessary to collect all available documents prior to judging the cause of death.

Two-dimensional fusion imaging of planar bone scintigraphy and radiographs in patients with clinical scaphoid fracture: an imaging study

BACKGROUND

Although magnetic resonance imaging (MRI) is now considered the gold standard in second-line imaging of patients with suspected scaphoid fracture and negative radiographs, bone scintigraphy can be used in patients with pacemakers, metallic implants, or other contraindications to MRI. Bone scintigraphy is highly sensitive for the detection of fractures, but exact localization of scintigraphic lesions may be difficult and can negatively affect diagnostic accuracy.

PURPOSE

To investigate the influence of image fusion of planar bone scintigraphy and radiographs on image interpretation in patients with suspected scaphoid fracture.

MATERIAL AND METHODS

In 24 consecutive patients with suspected scaphoid fracture, a standard planar bone scintigraphy of both hands was supplemented with fusion imaging of the injured wrist. Standard and fusion images were evaluated independently by three experienced nuclear medicine physicians. In addition to the diagnosis, the degree of diagnostic confidence was scored in each case.

RESULTS

The addition of fusion images changed the interpretation of each of the three observers in seven, four, and two cases, respectively, reducing the number of positive interpretations of two of the observers from 11 and nine cases to six and seven cases, respectively. The degree of diagnostic confidence increased significantly in two observers, and interobserver agreement increased in all three pairs of observers from 0.83, 0.57, and 0.73 to 0.89, 0.8, and 0.9, respectively.

CONCLUSION

Image fusion of planar bone scintigrams and radiographs has a significant influence on image interpretation and increases both diagnostic confidence and interobserver agreement.

Intracranial hemodynamics during intravenous infusion of glyceryl trinitrate

The mechanisms of glyceryl trinitrate (GTN)-induced headache are not fully elucidated. In this study we administered GTN 0.5 μg/kg/min i.v. for 20 min in six healthy volunteers. Before, during and 60 min after the infusion, we investigated regional cerebral blood flow (rCBF), cerebral blood volume (CBV), both estimated with SPECT, and blood flow velocity (BFV) in the middle cerebral artery (MCA), measured with transcranial Doppler. Headache was scored on a numerical verbal rating (0–10) scale. rCBF was unchanged, CBV was slightly increased (13%) during GTN infusion, whereas BFV decreased both during (20%) and 60 min (15%) after GTN. Headache was short-lived and maximal during infusion. This discrepancy of time-effect curves for the effect of GTN on headache and dilatation of MCA indicates that MCA is most likely not the primary source of pain in GTN-induced headache. The time-effect curves for the effect of GTN on headache and on dilation of MCA differed markedly. This indicates that MCA is most likely not the primary source of pain in GTN-induced headache.

[123I]Epidepride binding to cerebellar dopamine D2/D3 receptors is displaceable: Implications for the use of cerebellum as a reference region

The low density of cerebellar dopamine D(2)/D(3) receptors provides the basis for using the cerebellum as a representation of free- and non-specifically bound radioligand in positron emission tomography (PET) and single photon emission computed tomography (SPECT) studies. With the development of ultra high-affinity dopamine D(2)/D(3) ligands like [(123)I]epidepride, [(18)F]fallypride, and [(11)C]FLB-457, quantification of extrastriatal low density receptor populations including the cerebellum is possible with important implications for calculation of binding parameters. [(123)I]epidepride-SPECT was performed in 23 patients with schizophrenia before and after 3 months of antipsychotic treatment with either risperidone (n=14) or zuclopenthixol (n=9). In the unblocked situation and partially blocked situation, the average distribution volumes were 5.2+/-1.3 mL/mL and 4.0+/-0.8 mL/mL, respectively. The paired distribution volumes were reduced by 22+/-15% (mean+/-SD) after antipsychotic treatment (p<0.0001, paired Student's t-test). From the paired distribution volumes in cerebellum and extrastriatal regions, the average distribution volume representing free and non-specifically bound [(123)I]epidepride was calculated to be 3.3+/-0.8 mL/mL. Both the % [(123)I]epidepride fraction of plasma radioactivity (p>0.76) and the plasma [(123)I]epidepride concentration (p>0.45) were unchanged after antipsychotic treatment (paired Student's t-test). These results strongly suggest the presence of "non-negligible" specific [(123)I]epidepride binding to dopamine D(2)/D(3) receptors in the cerebellum. Using the cerebellum as a representation of free and non-specifically bound radioligand and neglecting the specifically bound component may lead to results that erroneously imply that antipsychotic drugs bind to extrastriatal dopamine D(2)/D(3) receptors with a higher affinity than to striatal dopamine D(2)/D(3) receptors.

Dopamine transporter imaging and the effects of deep brain stimulation in patients with Parkinson’s disease

PURPOSE

Single-photon emission computed tomography (SPECT) with [123I]FP-CIT is a marker for loss of presynaptic dopamine transporters in the striatum in Parkinson's disease (PD). We used [123I]FP-CIT SPECT in order to evaluate binding to the dopamine transporter before and after neurosurgical treatment with bilateral stimulation in the subthalamic nucleus (STN).

METHODS

Thirty-five patients with levodopa-responsive PD were examined with [123I]FP-CIT SPECT pre-operatively (baseline scan: mean 3 months before surgery), and 3 and 12 months after surgery.

RESULTS

Pre-operatively, all patients already had substantial signs of severe nigrostriatal neuronal loss as determined from the [123I]FP-CIT SPECT scans. One year after surgery the specific [123I]FP-CIT binding to the striatum was significantly reduced by 10.3% compared with the pre-operative baseline scan. The mean time span from the baseline scan before surgery to the follow-up scan 1 year after surgery was 16.2 months. Hence, the rate of reduction equals a mean annual reduction of 7.7%. A comparable control group of patients with PD who did not undergo surgery was also examined longitudinally. In this group the specific binding of [123I]FP-CIT was reduced by 6.7% per year.

CONCLUSION

The specific binding of [123I]FP-CIT was reduced equally in the STN-stimulated patients and a group of non-operated PD patients with advanced disease. Our study does not support the notion that electrode implantation and STN stimulation exert a neuroprotective effect by themselves.

Frontal dopamine D(2/3) receptor binding in drug-naive first-episode schizophrenic patients correlates with positive psychotic symptoms and gender

BACKGROUND

The aim of the study was to examine extrastriatal dopamine D(2/3) receptor binding and psychopathology in schizophrenic patients, and to relate binding potential (BP) values to psychopathology.

METHODS

Twenty-five drug-naive schizophrenic patients and 20 healthy controls were examined with single-photon emission computerized tomography (SPECT) using the D(2/3)-receptor ligand [123I]epidepride.

RESULTS

In the hitherto largest study on extrastriatal D(2/3) receptors we detected a significant correlation between frontal D(2/3) BP values and positive schizophrenic symptoms in the larger group of male schizophrenic patients, higher frontal BP values in male (n = 17) compared to female (n = 8) patients, and - in accordance with this - significantly fewer positive schizophrenic symptoms in the female patients. No significant differences in BP values were observed between patients and controls; the patients, however, had significantly higher BP in the right compared to the left thalamus, whereas no significant hemispheric imbalances were observed in the healthy subjects.

CONCLUSIONS

The present data are the first to confirm a significant correlation between frontal D(2/3) receptor BP values and positive symptoms in male schizophrenic patients. They are in agreement with the hypothesis that frontal D(2/3) receptor activity is significant for positive psychotic symptoms. Additionally, the data support a thalamic hemispheric imbalance in schizophrenia.

Hemodynamic and neuroendocrine responses to changes in sodium intake in compensated heart failure

Patients with untreated heart failure (HF) exhibit a blunted hemodynamic and neuroendocrine response to a high sodium intake, leading to excessive sodium and water retention. However, it is not known whether this is the case for patients with compensated HF receiving angiotensin-converting enzyme inhibitors and β-adrenoreceptor blockers. Therefore, we determined the hemodynamic and neuroendocrine responses to 1 wk of a low-sodium diet (70 mmol/day) and 1 wk of a high-sodium diet (250 mmol/day) in 12 HF patients and 12 age-matched controls in a randomized, balanced fashion. During steady-state conditions, hemodynamic and neuroendocrine examinations were performed at rest and during bicycle exercise. In seated HF patients, high sodium intake increased body weight (1.6 ± 0.4%), plasma volume (9 ± 2%), cardiac index (14 ± 6%), and stroke volume index (21 ± 5%), whereas mean arterial pressure was unchanged. Therefore, the total peripheral resistance decreased by 10 ± 4%. Similar hemodynamic changes were observed during an incremental bicycle exercise test. Plasma concentrations of angiotensin II and norepinephrine were suppressed, whereas plasma pro-B-type natriuretic peptide remained unchanged. In conclusion, high sodium intake was tolerated without any excessive sodium and water retention in medically treated patients with compensated HF. The observation that high sodium intake improves cardiac performance, induces peripheral vasodilatation, and suppresses the release of vasoconstrictor hormones does not support the advice for HF patients to restrict dietary sodium.

Dopa-responsive dystonia and early-onset Parkinson's disease in a patient with GTP cyclohydrolase I deficiency?

We describe a patient with a combination of dystonic and parkinsonian signs. Paraclinical studies revealed a mutation in the GTP cyclohydrolase I gene (GCH1) and a decrease in [123I]-N-omega-fluoropropyl-2beta-carbomethoxy-3beta-(4-iodophenyl) nortropane (123I-FP-CIT) binding ratios indicative of Parkinson's disease. We conclude that the patient probably suffers from a variant of dopa-responsive dystonia (DRD) or two separate movement disorders, normally considered to be differential diagnoses, DRD and early-onset Parkinson's disease with resulting difficulties concerning treatment and prognosis.

Relationship between nigrostriatal dopaminergic degeneration, urinary symptoms, and bladder control in Parkinson's disease

Patients with Parkinson's disease (PD) often have lower urinary tract symptoms (LUTS). Studies have indicated a correlation between dopaminergic degeneration and LUTS and presence of overactive bladder. We evaluated 18 patients with Parkinson's disease using single-photon emission computerized tomography (SPECT) imaging of the dopamine transporter with [(123)I]-FP-CIT, and bladder symptoms were assessed using questionnaires and full urodynamic evaluation both in medicated state and after cessation. Bladder symptoms correlated with age, stage and severity of disease but not with uptake of the ligand in the striatum. Patients with bladder symptoms had a significant lower uptake in the striatum compared with patients without LUTS. In patients with severe bladder dysfunction, LUTS correlated with putamen/caudate ratio. The specific binding of the ligand did not correlate with urodynamics parameters or any change in these after wash-out. Our findings suggest that the presence of LUTS is associated with the degeneration of the total number of nigrostriatal dopaminergic neurones, whilst the severity of bladder dysfunction is correlated with the relative degeneration of the caudate nucleus. The effects of medication on bladder control, as evaluated by urodynamics are believed to involve structures outside the basal ganglia.

"Central command" and insular activation during attempted foot lifting in paraplegic humans

The relationship between cardiovascular regulation and brain activation was investigated during attempted foot lifting in paraplegic subjects and during rhythmic handgrip exercise at one-third of maximum voluntary contraction force. Brain areas of interest were the primary sensory-motor area and the insula, a hypothesized center for a central nervous feed-forward mechanism involved in cardiovascular control ("central command"). This mechanism is complementary to the usual known feedback pathways such as skeletal muscle afferent signals. Regional cerebral blood flow (rCBF) was measured in eight normal and three paraplegic subjects using positron emission tomography (PET) and oxygen-15-labeled water. Statistical parametric maps were calculated from the images comparing rest and handgrip. Paraplegics were also scanned during attempted foot lifting, a condition without sensory feedback. During activation tasks, heart rate and mean arterial pressure increased. PET activation responses (P < 0.05, corrected for multiple comparisons) were found in the contralateral primary sensory-motor area, the supplementary motor area, ipsilateral cerebellum, and bilaterally in the insula. A conjunction analysis showing responses common to handgrip and attempted foot lifting revealed activation in the right central insula (P < 0.05, corrected) in concordance with the concept of a central command feed-forward hypothesis.

Alpha-contingent EEG feedback reduces SPECT rCBF variability

EEG feedback methods, which link the occurrence of alpha to the presentation of repeated visual stimuli, reduce the relative variability of subsequent, alpha-blocking event durations. The temporal association between electro-cortical field activation and regional cerebral blood flow (rCBF) led us to investigate whether the reduced variability of alpha-blocking durations with feedback is associated with a reduction in rCBF variability. Reduced variability in the rCBF response domain under EEG feedback control might have methodological implications for future brain-imaging studies. Visual stimuli were randomly presented to seven subjects, contingent upon the occurrence of alpha (alpha-contingent stimulation (ACS)) or alpha-blocking (not-alpha-blocking-contingent stimulation (NACS)) events. We employed a within-subjects design. rCBF was measured from multiple, cortical and sub-cortical regions. The primary dependent variables were the Mean, Standard Deviation and the ratio of Mean/Standard Deviation of: 1) the alpha-blocking response durations and 2) the temporally summated rCBF responses within the Visual Associative regions of interest (ROIs). Additional within-subjects rCBF measures were derived to quantify the variance-reducing effects of ACS across multiple, distributed areas of the brain. Both EEG and rCBF measures demonstrated decreased variability under ACS. This improved control was seen for localized as well as anatomically distributed rCBF measures.

Gamma-camera 18F-FDG PET in diagnosis and staging of patients presenting with suspected lung cancer and comparison with dedicated PET

It is not clear whether high-quality coincidence gamma-PET (gPET) cameras can provide clinical data comparable with data obtained with dedicated PET (dPET) cameras in the primary diagnostic work-up of patients with suspected lung cancer. This study focuses on 2 main issues: direct comparison between foci resolved with the 2 different PET scanners and the diagnostic accuracy compared with final diagnosis determined by the combined information from all other investigations and clinical follow-up.

METHODS

Eighty-six patients were recruited to this study through a routine diagnostic program. They all had changes on their chest radiographs, suggesting malignant lung tumor. In addition to the standard diagnostic program, each patient had 2 PET scans that were performed on the same day. After administration of 419 MBq (range = 305-547 MBq) (18)F-FDG, patients were scanned in a dedicated PET scanner about 1 h after FDG administration and in a dual-head coincidence gamma-camera about 3 h after tracer injection. Images from the 2 scans were evaluated in a blinded set-up and compared with the final outcome.

RESULTS

Malignant intrathoracic disease was found in 52 patients, and 47 patients had primary lung cancers. dPET detected all patients as having malignancies (sensitivity, 100%; specificity, 50%), whereas gPET missed one patient (sensitivity, 98%; specificity, 56%). For evaluating regional lymph node involvement, sensitivity and specificity rates were 78% and 84% for dPET and 61% and 90% for gPET, respectively. When comparing the 2 PET techniques with clinical tumor stage (TNM), full agreement was obtained in 64% of the patients (Cohen's kappa = 0.56). Comparing categorization of the patients into clinical relevant stages (no malignancy/malignancy suitable for treatment with curative intent/nontreatable malignancy), resulted in full agreement in 81% (Cohen's kappa = 0.71) of patients.

CONCLUSION

Comparing results from a recent generation of gPET cameras obtained about 2 h later than those of dPET, there was a fairly good agreement with regard to detecting primary lung tumors but slightly reduced sensitivity in detecting smaller malignant lesions such as lymph nodes. Depending on the population to be investigated, and if dPET is not available, gPET might provide significant diagnostic information in patients in whom lung cancer is suspected.

Neurophysiological tests and neuroimaging procedures in non-acute headache: guidelines and recommendations

The use of instrumental examinations in headache patients varies widely. In order to evaluate their usefulness, the most common instrumental procedures were evaluated, on the basis of evidence from the literature, by an EFNS Task Force (TF) on neurophysiological tests and imaging procedures in non-acute headache patients. The conclusions of the TF regarding each technique are expressed in the following guidelines for clinical use. 1 Interictal electroencephalography (EEG) is not routinely indicated in the diagnostic evaluation of headache patients. Interictal EEG is, however, indicated if the clinical history suggests a possible diagnosis of epilepsy (differential diagnosis). Ictal EEG could be useful in certain patients suffering from hemiplegic and basilar migraine. 2 Recording of evoked potentials is not recommended for the diagnosis of headache disorders. 3 There is no evidence to justify the recommendation of autonomic tests for the routine clinical examination of headache patients. 4 Manual palpation of pericranial muscles, with standardized palpation pressure, can be recommended for subdividing patient groups but not for diagnosis. Pressure algometry and electromyography (EMG) cannot be recommended as clinical diagnostic tests. 5 In adult and paediatric patients with migraine, with no recent change in attack pattern, no history of seizures, and no other focal neurological signs or symptoms, the routine use of neuroimaging is not warranted. In patients with atypical headache patterns, a history of seizures and/or focal neurological signs or symptoms, magnetic resonance imaging (MRI) may be indicated. 6 If attacks can be fully accounted for by the standard headache classification [International Headache Society (IHS)], a positron emission tomography (PET) or single-photon emission computerized tomography (SPECT) and scan will generally be of no further diagnostic value. 7 Nuclear medicine examinations of the cerebral circulation and metabolism can be carried out in subgroups of headache patients for diagnosis and evaluation of complications, when patients experience unusually severe attacks, or when the quality or severity of attacks has changed. 8 Transcranial Doppler examination is not helpful in headache diagnosis. Although many of the examinations described are of little or no value in the clinical setting, most of the tools have a vast potential for further exploring the pathophysiology of headaches and the effects of pharmacological treatment.