Striatal volume is related to phonemic verbal fluency but not to semantic or alternating verbal fluency in early Parkinson’s disease

Verbal fluency impairments are frequent in Parkinson’s disease (PD) and they may be present already at early stages. Semantic fluency impairment is associated with Parkinson’s disease dementia and temporal, frontal and cerebellar cortical changes. Few studies have addressed cerebral structural correlates of different verbal fluency tasks in early stage PD. We therefore studied gray matter volumes of T1-weighted MRI images using voxel-based morphometry in relation to semantic, phonemic, and alternating verbal fluency in younger (mean age <65 years), early stage (mean disease duration <3 years), non-demented PD patients (n = 28) and healthy controls (n = 27). We found a significant association between worse phonemic fluency and smaller striatal, namely right caudate gray matter volume in the PD group only (family-wise error corrected p = 0.007). Reduced semantic fluency was associated with smaller gray matter volumes in left parietal cortex (p = 0.037) and at trend level with smaller bilateral cerebellum gray matter volume across groups (p = 0.062), but not in the separate PD or control groups. There were no significant relationships between alternating fluency and gray matter volumes in the whole sample or in the groups separately. The fact that phonemic fluency, but not semantic or alternating fluency, was associated with caudate gray matter volume at early stage PD suggests that different fluency tasks rely on different neural substrates, and that language networks supporting semantic search and verbal-semantic switching are unrelated to brain gray matter volume at early disease stages in PD.     

Apolipoprotein E polymorphism and acute ischemic stroke: a diffusion- and perfusion-weighted magnetic resonance imaging study.

Diffusion- and perfusion-weighted magnetic resonance imaging (MRI) was used to study the putative effects of apolipoprotein E (ApoE) polymorphism in stroke. Thirty-one patients with acute stroke, comparative for age and gender were scanned, nine of whom were ApoE allele epsilon 4 carriers. Initially, less than 24 hours from the onset of stroke, the epsilon 4 carriers had significantly smaller volumes of hypoperfusion on relative cerebral blood volume map (P = 0.001), and smaller infarct volumes (P = 0.008) compared with the noncarriers. By day 8, this difference in the infarct volumes had disappeared, suggesting relatively enhanced infarct growth. On average, the total infarct volume increased 145% of the initial infarct volume in the epsilon 4 carriers, and 84% in the noncarriers. There were strong correlations between the imaging findings and clinical status initially and with the outcome 3 months after the stroke in the epsilon 4 noncarriers, but, with a single exception at acute phase, a lack thereof in the epsilon 4 carriers. These patterns were virtually similar in a subgroup of patients with middle cerebral artery stroke. These data support the hypothesis of increased general vulnerability of the brain in the epsilon 4 carriers. Thus, the effects of ApoE polymorphism should be accounted for when interpreting diffusion- and perfusion-weighted MRI studies, particularly if predicting lesion growth.     

Clinical usefulness of bronchoalveolar lavage in heart transplant recipients with suspected lower respiratory tract infection.

BACKGROUND: Bronchoscopy with bronchoalveolar lavage (BAL) is the recommended initial invasive diagnostic procedure when lower respiratory tract infection is suspected in solid-organ transplant recipients. In this study, we evaluated the clinical impact and safety of bronchoscopy with BAL in heart transplant recipients. METHODS: We reviewed all 44 consecutive diagnostic bronchoscopies with BAL that were performed in 35 heart transplant recipients at Helsinki University Central Hospital between May 1988 and December 2001. RESULTS: Bronchoscopy findings established specific microbiologic diagnoses in 18 of 44 (41%) cases, and 14 of 44 (32%) bronchoscopic findings led to changes in therapy. The diagnostic yield of bronchoscopy from 1 to 6 months after transplantation was 73%, significantly better (p = 0.002) than diagnostic yield during the first month (18%) and after 6 months (28%). Pneumocystis carinii and cytomegalovirus were the most frequently detected pathogens in the BAL fluid. Cytomegalovirus pneumonia carried a high mortality rate (44%), whereas all patients with P carinii pneumonia recovered. Fourteen episodes were diagnosed as bacterial pneumonia, but because of empiric antibiotic therapy that was started widely before bronchoscopy, a microbiologic diagnosis was established in only 1 case. However, all patients with community-acquired pneumonia responded to empiric therapy. Four cases of major complications occurred after bronchoscopy, all cardiovascular but none fatal. CONCLUSIONS: Bronchoscopy with BAL is a useful diagnostic tool in heart transplant recipients, especially between 1 and 6 months after transplantation.     

Differences in striatal dopamine transporter density between tremor dominant and non-tremor Parkinson’s disease

Purpose

Parkinson’s disease (PD) can manifest with a tremor-dominant or a non-tremor (akinetic-rigid) phenotype. Although the tremor-dominant subtype may show a better prognosis, there is limited information on the phenotypic differences regarding the level of striatal dopamine transmission. The present study investigated striatal dopamine transporter (DAT) binding characteristics in a large sample of patients with and without tremor.

Methods

[¹²³I]FP-CIT SPECT scans of 231 patients with a clinical diagnosis of PD and abnormal FP-CIT binding (157 with tremor, 74 without tremor) and 230 control patients with normal FP-CIT binding (148 with tremor, 82 without tremor) were analysed using an automated region-of-interest analysis of the scans (BRASS). Specific striatal binding ratios were compared between phenotypes and groups using age, sex, and symptom duration, predominant side of symptoms, dopaminergic medications and scanner as covariates.

Results

Patients with PD had 28.1 – 65.0 % lower binding in all striatal regions compared to controls (p?p?Conclusion The motor phenotype is associated with the extent of caudate dopamine terminal loss in PD, as dopamine function is relatively more preserved in tremor patients. Symptom type is related to caudate dopamine function only in association with Parkinsonian dopaminergic degeneration, not in intact dopamine systems in patients with non-PD tremor.     

Integrating multi-source data for a tropical forest inventory—a case study in the Kon Tum region,Vietnam

This article presents a processing chain for forest volume mapping based on multi-source forest inventory methodology and the existing inventory data collected from the Kon Tum region, Vietnam. The modelling framework for imputing tally tree heights was built based on a mixed-effects height generalisation model. Mapping of the stem volume was based on nearest neighbour techniques (k-NN) and Landsat TM data after relative calibration with MODIS image material as underlying reference. The use of optical image materials, together with the demanding conditions set by a tropical forest structure, resulted in a moderate root mean square error value (76.6%) for the stem volume. The resulting volume maps, which were based on an objective estimation procedure, create the appropriate model dataset needed for testing the optimal large-scale inventory designs of forthcoming forest inventories that will be carried out in Vietnam.     

Differential turnover of cortical and trabecular bone in transgenic mice overexpressing cathepsin K

Cathepsin K is a major osteoclastic protease. We have recently shown that overexpression of mouse cathepsin K gene in transgenic UTU17 mouse model results in high turnover osteopenia of metaphyseal trabecular bone at the age of 7 months. The present report extends these studies to a systematic analysis of cortical bone in growing and adult mice overexpressing cathepsin K. Mice homozygous for the transgene locus (UTU17+/+) and their control littermates were studied at the age of 1, 3, 7, and 12 months. Bone properties were analyzed using peripheral quantitative computed tomography (pQCT), histomorphometry, histochemistry, radiography, and biomechanical testing. In addition, the levels of biochemical markers of bone turnover were measured in the sera. Unexpectedly, cortical thickness and cortical bone mineral density were increased in the diaphyseal region of growing and adult UTU17+/+ mice. This was associated with an increased number of vascular canals leading to increased cortical porosity in UTU17+/+ mice without changes in the ultimate bending force or stiffness of the bone. In UTU17+/+ mice, osteopenia of metaphyseal trabecular bone was observed already at the age of 1 month. In sera of 1-month-old UTU17+/+ mice, the activity of tartrate-resistant acid phosphatase 5b was decreased and the levels of osteocalcin increased. Our results support the role of cathepsin K as a major proteinase in osteoclastic bone resorption. Excessive production of cathepsin K induced osteopenia of metaphyseal trabecular bone and increased the porosity of diaphyseal cortical bone. The increased cortical thickness and bone mineral density observed in diaphyses of UTU17+/+ mice demonstrate the different nature and reactivity of trabecular and cortical bone in mice. These results suggest that the biomechanical properties of cortical bone are preserved through adaptation as outlined in Wolff's law.     

A prospective study comparing cytomegalovirus antigenemia, DNAemia and RNAemia tests in guiding pre-emptive therapy in thoracic organ transplant recipients

We evaluated the usefulness of DNAemia and mRNAemia tests in guiding the pre-emptive therapy against cytomegalovirus (CMV) infections in thoracic organ transplant recipients using antigenemia test as the reference. Seven lung (LTR) and 14 heart (HTR) transplant recipients were prospectively monitored for CMV by antigenemia, DNAemia (Cobas Amplicor PCR Monitor) and pp67-mRNAemia (NASBA) tests. However, only the antigenemia test guided pre-emptive therapy with cut-off levels of >or=2 and >or=5-10 pp65-positive leukocytes/50 000 leukocytes in the LTRs and HTRs, respectively. CMV DNAemia was detected in 26/28 (93%) and RNAemia in 17/28 (61%) of the CMV antigenemias requiring antiviral therapy (P = 0.01). Optimal DNAemia levels (sensitivity/specificity) estimated from receiver-operating characteristic curve to achieve maximal sum of sensitivity and specificity were 400 (75.9/92.7%), 850 (91.3/91.3%) and 1250 (100/91.5%) copies/ml for the antigenemia of 2, 5 and 10 pp65-positive leukocytes, respectively. The sensitivities of nucleic acid sequence-based amplification (NASBA) were 25.9%, 43.5% and 56.3% in detecting the same cut-off levels of antigenemia. In thoracic organ transplant recipients, the Cobas PCR assay is comparable with the antigenemia test in guiding pre-emptive therapy against CMV infections when threshold levels of over 5 pp65-antigen-positive leukocytes are used as the reference. In contrast, the low sensitivity of NASBA limits its usefulness in the guidance of pre-emptive therapy.     

Instrumented spondylodesis in degenerative spondylolisthesis with bioactive glass and autologous bone: a prospective 11-year follow-up

A prospective long-term follow-up study of bioactive glass (BAG)-S53P4 and autogenous bone (AB) used as bone graft substitutes for posterolateral spondylodesis in treatment of degenerative spondylolisthesis during 1996 to 1998 was conducted. The surgical procedure was a standardized instrumented posterolateral fusion that used USS/VAS. BAG was implanted on the left side of the fusion bed and AB on the right side. The operative outcome was evaluated on x-rays and computed tomography scans, and a clinical examination was also performed. Seventeen patients (12 women, 5 men) participated in the 11-year follow-up. The mean Oswestry Disability Index score at the follow-up was 21 (range 0 to 52), compared with 49 (range 32 to 64) at the preoperative time. A solid bony fusion was seen on computed tomography scans on the AB side in all patients and on the BAG side in 12 patients. The fusion rate of all fusion sites (n=41) for BAG as a bone substitute was 88% at the L4/5 level and 88% at the L5/S1 level. The use of BAG as a bone graft extender can be considered as a good alternative in spinal surgery in the future.