Young's double-slit experiment with undulator vortex radiation in the photon-counting regime.

Young's double-slit interference experiments with undulator vortex radiation were conducted, focusing on photon-counting regime. To isolate the second harmonic radiation in the ultraviolet range emitted from the helical undulator and achieve successful counting measurements, an ultranarrow bandpass filter was utilized under an extremely low-current mode of the electron storage ring. It was observed that the photon spots on the detector, after passing through the double slits, appeared to be randomly distributed. However, upon integrating these photon spots, it was confirmed that interference fringes with characteristic features of optical vortices, such as dark and broken/distorted stripes in the center, were formed. The reproducibility of these interference fringes was confirmed by calculating the optical path difference for the optical vortex reaching the double slits, as well as the optical path difference resulting from normal double-slit interference. Consequently, these findings indicate that even in the state of a single photon, the radiation emitted spontaneously by a high-energy electron in spiral motion possesses the nature of an optical vortex, characterized by a spiral wavefront.

Globular glial tauopathy Type II: Clinicopathological study of two autopsy cases.

Globular glial tauopathies (GGTs) are four-repeat tauopathies characterized by the presence of two types of tau-positive globular glial inclusions (GGIs): globular oligodendrocytic and astrocytic inclusions (GOIs and GAIs). GGTs are classified into three different neuropathological subtypes: Types I, II and III. We report two patients with GGTs - a 76-year-old woman and a 70-year-old man - in whom the disease duration was 5 and 6 years, respectively. Both patients exhibited upper and lower motor neuron signs and involuntary movements, and the latter also had dementia with frontotemporal cerebral atrophy evident on magnetic resonance imaging. Neuropathologically, in both cases, the precentral gyrus was most severely affected, and at the gray-white matter junction there was almost complete loss of Betz cells and occurrence of GOIs and coiled bodies with numerous neuropil threads. Both patients also showed neuronal loss and GGIs (mostly GOIs) in many other central nervous system regions, including the basal ganglia. Apart from the degree of regional severity, the distribution pattern was essentially the same in both cases. However, GAIs were not conspicuous in any of the affected regions. Based on the morphology and distribution pattern of the GGIs, we diagnosed the present two patients as having GGT Type II. Electron microscopic and biochemical findings in the former were consistent with the diagnosis. Type II cases are reported to be characterized by pyramidal features reflecting predominant motor cortex and corticospinal tract degeneration. The present observations suggest that a variety of neurological features, including dementia, can occur in GGT Type II reflecting widespread degeneration beyond the motor neuron system.

Frontotemporal dementia with co-occurrence of astrocytic plaques and tufted astrocytes, and severe degeneration of the cerebral white matter: a variant of corticobasal degeneration?

We report two patients who exhibited frontotemporal dementia (FTD) with unusual neuropathological features. The ages of the patients at death were 65 and 67 years, the disease durations were 6 and 5 years, and the clinical diagnoses were Pick's disease and corticobasal degeneration (CBD), respectively. At autopsy, both cases exhibited neuropathological findings compatible with those of CBD, including atrophy of the frontal and parietal lobes, neuronal loss and gliosis in the cortical and subcortical regions, and presence of cortical ballooned neurons and astrocytic plaques (APs). In both cases, immunoblotting of insoluble tau exhibited the pattern of selective accumulation of four-repeat tau, a finding that is also compatible with CBD. However, severe degeneration was evident in the frontal and parietal white matter in both cases. Moreover, a striking finding was the widespread presence in the affected cortex of tufted astrocytes (TAs), which are characteristic of progressive supranuclear palsy (PSP). Neither co-occurrence of APs and TAs nor severe degeneration of the cerebral white matter is a feature of either CBD or PSP. No mutations were found in the tau gene in either case. In conclusion, the possibility that these two cases represent a new neuropathological phenotype of non-familial FTD rather than simply a variant of CBD cannot be completely excluded.

[A case of mitochondrial myopathy with external ophthalmoplegia and ataxic neuropathy].

We report a 70-year-old woman with bilateral optic atrophy, external ophthalmoplegia, bilateral blepharoptosis, and sensory ataxic neuropathy. She had a visual disturbance since childhood. She had dysarthria and gait disturbance at 28 years old. She had bilateral blepharoptosis, marked gait disturbance and dysphagia at 50. On neurological examination, external ophthalmoplegia, bilateral blepharoptosis, mild weakness and muscular atrophy of promixal muscles, hyporeflexia, positive Romberg sign, glove and stocking type sensory disturbance including hypesthesia, hypalgesia, and bathyhypesthesia were found. She did not show pigmented retinopathy, cognitive dysfunctions, hearing loss, cerebellar ataxia, Hoffman reflex nor Babinski sign. She did not show increased lactic acid nor pyruvic acid in the cerebrospinal fluid but mild increase of pyruvic acid (1.0 mg/dl) in her serum. The conduction velocity and amplitude of CMAP of tibial nerve was 37.4 m/sec and 2.9 mV, respectively. The SNAP of ulner and sural nerve were not evoked. Brain MRI showed no pathological findings. Muscle biopsy from the biceps muscle showed many ragged-red fibers (5.3%) and some fibers with decreased or absent COX activity. Sural nerve biopsy showed a marked loss of large myelinated fibers with thin myelinated fibers, and onion-bulb formation. The clinical findings of our patient is similar to that of SANDO (the triad of sensory ataxic neuropathy, dysarthria, and ophthalmoparesis), however, large mtDNA deletion reported by Fadic in patients with SANDO was not found in our patient. It might be possible that her mtDNA deletion is small or point mutation is existed.