Urticaria pigmentosa localized on radiation field

A woman previously treated by radiotherapy for a breast cancer developed urticaria pigmentosa mainly restricted to the irradiation field, without any systemic symptoms. Localized forms of urticaria pigmentosa are exceptional, and their triggering factors are poorly understood. Several hypotheses can be discussed in this peculiar observation, among which a direct role of radiotherapy in the occurrence of cutaneous lesions cannot be ruled out.     

Poststroke dementia: influence of hippocampal atrophy

BACKGROUND: The prevalence of dementia is increased after stroke. Medial temporal lobe atrophy (MTLA) is associated with Alzheimer disease, and with prestroke dementia in patients who have had a stroke. OBJECTIVE: To determine the influence of MTLA on the long-term risk of dementia after stroke, after excluding the patients who had prestroke dementia. METHODS: The study was conducted in 144 consecutive patients who had a stroke, who were aged 40 years or older (66 women and 78 men; median age, 72 years), and who had an Informant Questionnaire on Cognitive Decline in the Elderly score lower than 104. On admission to the hospital all patients underwent a noncontrast computed tomographic scan including temporal lobe-positioned slices. A cut-off of 11.5 mm was used to differentiate patients with MTLA from those without MTLA. Patients were followed up with clinical and cognitive assessments over a 3-year period. RESULTS: Three years after stroke, 34 patients (23.6%) had developed new-onset dementia. The cumulative proportion of survivors without dementia was 57.6% in patients with MTLA and 80.8% in patients without MTLA (P =.02). The unadjusted relative risk of poststroke dementia associated with MTLA was 2.3 (95% confidence interval, 1.1-4.7). However, using the Cox proportional hazards model, MTLA did not seem to be an independent predictor of poststroke dementia. Independent predictors of poststroke dementia were increasing age, diabetes mellitus, severity of the clinical deficit at admission, and severity of leukoaraiosis on computed tomography. CONCLUSIONS: Patients who had a stroke and MTLA more frequently develop dementia than patients without MTLA, but our study does not suggest that MTLA independently contributes to dementia. A longer follow-up may be necessary to reevaluate the influence of MTLA.     

Neutron-activation analysis: a novel method for the assay of iohexol

Accurate measurement of glomerular filtration rate (GFR) is of great importance in both research and clinical medicine. Available methods require radiation exposure or are technically difficult, thereby limiting their utility. Recent work has validated plasma clearance of nonradioactive contrast agents (iohexol and iothalamate) for the measurement of GFR. However, their clinical utility has been restricted by the difficulties associated with the detection of contrast agents in serum. In this investigation, we evaluate the sensitivity, accuracy and precision of neutron activation analysis (NAA) to measure serum iohexol at concentrations necessary for estimating GFR. We subjected aliquots of serum containing 0 to 6470 microg/mL iohexol to neutron activation by placing them in a neutron beam for 1 minute. The activation process resulted in the elevation of iohexol's naturally abundant iodine 127 to iodine 128. The spontaneous decay of (128)I to xenon 128 (proportional to the amount of total iodine in the sample) was calculated by means of spectrographic analysis. The correlation between the predetermined elemental mass of iodine in the sample and that measured on NAA was then determined. A similar analysis was performed to establish the intra- and interday accuracy and precision, with multiple measurements taken over a single day and over the course of a month. We noted excellent correlation between iodine measured on NAA and the known elemental mass (r(2) =.99). Measurements were highly accurate (mean accuracy 2.4% +/- 1.8%), with excellent intra- and interday reliability (mean coefficient of variation 4.1% +/- 1.6%). NAA is a feasible and reproducible method of detecting iohexol for the purpose of measuring GFR.     

Atypical presentations of primary amyloid neuropathy

Primary amyloidosis (AL) may be complicated by peripheral neuropathy in 15-35% of cases. We report on four patients with atypical neurological presentations of AL neuropathy, whose diagnoses were delayed due to varied clinical presentations. The clinical presentation included painful sensory neuropathy (two patients), mononeuropathy multiplex (one patient), and primary demyelinating polyneuropathy (one patient). The latter two types of presentation have not been reported previously. The diagnosis was established by fat pad biopsy in two patients, lymph node biopsy in one, and sural nerve biopsy in one. Two patients were treated with high-dose melphalan followed by stem cell rescue, and one was treated with oral melphalan and prednisone. All three cases experienced stabilization of neuropathic symptoms. We report these cases in order to raise awareness of the varied clinical presentation of AL neuropathy.     

Retrograde reactions of Clarke's nucleus neurons after human spinal cord injury

Successful axon regeneration depends on the expression of regeneration-associated genes by axotomized neurons. Here, we demonstrate, for the first time to our knowledge, the expression of regeneration-associated genes by axotomized human CNS neurons. In situ hybridization and immunohistochemistry showed a transient induction of GAP-43 and c-jun in Clarke's nucleus neurons caudal to traumatic human spinal cord injury. These results support experimental data that nonregenerating central nervous system neurons can temporarily upregulate regeneration-associated genes, reflecting a transient regenerative capacity that fails over time.     

Histopathological alterations and functional brain deficits after transient hypoxia in the newborn rat pup: a long term follow-up

To assess temporal brain deficits consecutive to severe birth hypoxia, newborn rats were exposed for 20 min to 100% N2. This treatment induced a long-term growth retardation and a delayed, but only transient, neuronal loss (approximately 25%) in the CA1 hippocampus and parietal cortex, starting from 3 days and peaking at 6 days post-hypoxia. The expression profiles of various apoptosis-regulating proteins (including Bcl-2, Bax, p53 and caspase-3) were well correlated to the alterations of nuclear morphology depicted by 4,6-diamidino-2-phenylindole (DAPI). Whereas they confirmed a gradual histological recovery, specific DNA fragmentation patterns suggested that birth hypoxia may transiently reactivate the developmental programme of neuronal elimination. Although they successfully achieved various behavioral tests such as the righting reflex, negative geotaxis, locomotor coordination, and the eight-arm maze tasks, both developing and adult hypoxic rats were repeatedly slower than controls, suggesting that birth hypoxia is associated to moderate but persistent impairments of functional capacities.