Arterial versus total blood volume changes during neural activity-induced cerebral blood flow change: implication for BOLD fMRI.

Quantifying both arterial cerebral blood volume (CBV(a)) changes and total cerebral blood volume (CBV(t)) changes during neural activation can provide critical information about vascular control mechanisms, and help to identify the origins of neurovascular responses in conventional blood oxygenation level dependent (BOLD) magnetic resonance imaging (MRI). Cerebral blood flow (CBF), CBV(a), and CBV(t) were quantified by MRI at 9.4 T in isoflurane-anesthetized rats during 15-s duration forepaw stimulation. Cerebral blood flow and CBV(a) were simultaneously determined by modulation of tissue and vessel signals using arterial spin labeling, while CBV(t) was measured with a susceptibility-based contrast agent. Baseline versus stimulation values in a region centered over the somatosensory cortex were: CBF=150+/-18 versus 182+/-20 mL/100 g/min, CBV(a)=0.83+/-0.21 versus 1.17+/-0.30 mL/100 g, CBV(t)=3.10+/-0.55 versus 3.41+/-0.61 mL/100 g, and CBV(a)/CBV(t)=0.27+/-0.05 versus 0.34+/-0.06 (n=7, mean+/-s.d.). Neural activity-induced absolute changes in CBV(a) and CBV(t) are statistically equivalent and independent of the spatial extent of regional analysis. Under our conditions, increased CBV(t) during neural activation originates mainly from arterial rather than venous blood volume changes, and therefore a critical implication is that venous blood volume changes may be negligible in BOLD fMRI.     

Pycnogenol® as an Adjunct in the Management of Childhood Asthma

A randomized, placebo-controlled, double-blind study involving 60 subjects, aged 6-18 years old, was conducted over a period of 3 months to determine the effect of Pycnogenol® (a proprietary mixture of water-soluble bioflavonoids extracted from French maritime pine) on mild-to-moderate asthma. After baseline evaluation, subjects were randomized into two groups to receive either Pycnogenol® or placebo. Subjects were instructed to record their peak expiratory flow with an Assess® Peak Flow Meter each evening. At the same time, symptoms, daily use of rescue inhalers (albuterol), and any changes in oral medications were also recorded. Urine samples were obtained from the subjects at the end of the run-in period, and at 1-, 2-, and 3-month visits. Urinary leukotriene C₄/D₄/E₄ was measured by an enzyme immunoassay. Compared with subjects taking placebo, the group who took Pycnogenol® had significantly more improvement in pulmonary functions and asthma symptoms. The Pycnogenol® group was able to reduce or discontinue their use of rescue inhalers more often than the placebo group. There was also a significant reduction of urinary leukotrienes in the Pycnogenol® group. The results of this study demonstrate the efficacy of Pycnogenol® as an adjunct in the management of mild-to-moderate childhood asthma.     

Carotid intima-media thickness in Parkinson's disease.

There have been a few studies and inconsistent results regarding the coincidence of Parkinson's disease (PD) and atherosclerotic diseases, such as cerebrovascular disease. Carotid intima-media thickness (IMT) is a known marker for subclinical atherosclerosis. The aim of this study was to investigate the carotid IMT between PD patients and controls. We studied 43 patients with PD and 86 matched controls. The carotid IMT in PD patients was significantly smaller than in controls (0.796 +/- 0.179 mm vs. 0.913 +/- 0.237 mm, P < 0.05). In multivariate analysis, the carotid IMT was inversely associated with the duration of levodopa medication and the severity of PD. These results suggest that PD patients have a lower risk of atherosclerosis.     

Localization of ulnar neuropathy at the elbow using new stimulator for the inching test.

OBJECTIVE: To evaluate the usefulness of the TenElectrodes, a new stimulator for inching test, in the diagnosis and localization of ulnar neuropathy at the elbow (UNE). METHODS: Sixty-two ulnar nerves in 40 control subjects and 24 ulnar nerves in 23 patients with typical symptoms and signs of UNE were studied. The inching test of ulnar motor nerve using TenElectrodes was done along 8 cm across the elbow in the extended position. RESULTS: In the inching test of the control group, the mean segmental latency difference was 0.19+/-0.08 ms. Maximal latency difference over a 1 cm segment did not exceed 0.40 ms in any of the controls but exceeded 0.5 ms or more in all clinical UNE patients. In all UNE patients, the lesion sites were identified by the inching test using TenElectrodes: the retroepicondylar groove (54.2%), the humeroulnar arcade (29.2%), and dual compression (16.6%). CONCLUSIONS: TenElectrodes is a useful stimulator for the inching test in the diagnosis of UNE. The precise localization of compression was possible in all patients with UNE and the most common site was the retroepicondylar groove.     

Retropharyngeal lymph node metastasis from olfactory neuroblastoma: a report of two cases

Olfactory neuroblastoma is a rare, malignant neoplasm arising from the olfactory epithelium. It has an aggressive biological behavior that is characterized by local recurrence, atypical distant metastasis, and poor long-term prognosis. The incidence of cervical lymph node metastasis in olfactory neuroblastoma is variable, and treatment modalities are controversial. Moreover, few reports have been published concerning retropharyngeal lymph node metastasis from olfactory neuroblastoma. We present two cases of olfactory neuroblastoma with retropharyngeal lymph node metastasis. In addition, we provided a review of the current literature regarding olfactory neuroblastoma and retropharyngeal lymph node metastasis from olfactory neuroblastoma.     

Cyclosporin-A nephrotoxicity and acute cellular rejection in renal transplant recipients: correlation between radionuclide and histologic findings

Serial radionuclide studies using both Tc-99m DTPA (perfusion) and I-131 hippuran (tubular function) were correlated with histologic findings in 25 patients with renal transplants. These cases included 15 cases of cyclosporin-A nephrotoxicity (CsA-NT) and ten cases of acute cellular rejection that were retrospectively selected on the basis of biopsy findings and favorable clinical response to therapy specific for each of these conditions. The serial radionuclide studies enabled the correct diagnosis in 12 of 15 cases of CsA-NT and eight of ten cases of acute rejection. Posttherapy radionuclide studies, furthermore, demonstrated improvement consistent with clinical response. In all cases, the radionuclide results were available at least 24 hours before biopsy findings. These results indicate that serial radionuclide studies evaluating interval changes in both perfusion and tubular function are of significant value in the diagnosis and follow-up of CsA-NT and acute cellular rejection in transplant recipients. This initial experience suggests a sensitivity of 80%.