The Japanese Breast Cancer Society clinical practice guidelines for epidemiology and prevention of breast cancer, 2022 edition.

The Japanese Breast Cancer Society Clinical Practice Guidelines for Epidemiology and Prevention of Breast Cancer, 2022 Edition.

[A case of cerebral embolism with Coronavirus disease 2019].

A 63-year-old man, who had persistent fever for a month, was admitted to the hospital with sudden left arm palsy with a National Institutes of Health Stroke Scale score of 3. Consequently, brain MRI showed hyperintensity of the bilateral occipital, right parietal, and right frontal lobes on diffusion-weighted imaging. Moreover, FLAIR presented hyperintensity of the left occipital lobe. Magnetic resonance angiography detected the deficit of the blood-flow signal of the horizontal segment of the middle cerebral artery. He was diagnosed with acute ischemic stroke. In addition, chest CT showed ground-glass opacities, and test to detect SARS-CoV-2 was positive. Cerebral embolism was suspected. However, the source was unknown. His ischemic stroke was possibly associated with coagulation abnormality caused by coronavirus disease 2019.

The Cellular and Mechanical Basis for Response Characteristics of Identified Primary Afferents in the Rat Vibrissal System.

Compared to our understanding of the response properties of receptors in the auditory and visual systems, we have only a limited understanding of the mechanoreceptor responses that underlie tactile sensation. Here, we exploit the stereotyped morphology of the rat vibrissal (whisker) array to investigate coding and transduction properties of identified primary tactile afferents. We performed in vivo intra-axonal recording and labeling experiments to quantify response characteristics of four different types of identified mechanoreceptors in the vibrissal follicle: ring-sinus Merkel; lanceolate; clublike; and rete-ridge collar Merkel. Of these types, only ring-sinus Merkel endings exhibited slowly adapting properties. A weak inverse relationship between response magnitude and onset response latency was found across all types. All afferents exhibited strong "angular tuning," i.e., their response magnitude and latency depended on the whisker's deflection angle. Although previous studies suggested that this tuning should be aligned with the angular location of the mechanoreceptor in the follicle, such alignment was observed only for Merkel afferents; angular tuning of the other afferent types showed no clear alignment with mechanoreceptor location. Biomechanical modeling suggested that this tuning difference might be explained by mechanoreceptors' differential sensitivity to the force directed along the whisker length. Electron microscopic investigations of Merkel endings and lanceolate endings at the level of the ring sinus revealed unique anatomical features that may promote these differential sensitivities. The present study systematically integrates biomechanical principles with the anatomical and morphological characterization of primary afferent endings to describe the physical and cellular processing that shapes the neural representation of touch.

[A case of possible elderly onset rheumatoid meningitis without arthritis].

A 93-year-old man was admitted to our hospital with disturbance of consciousness. Brain magnetic resonance imaging (MRI) showed hyperintensity of the subarachnoid space in the left frontal and parietal lobes on diffusion weighted imaging (DWI) and fluid attenuated inversion recovery (FLAIR). Gadolinium-enhancement of the pia mater was also observed. We did not perform biopsy because of a high risk of perioperative complication. Although physical examination found no evidence of the rheumatoid arthritis, rheumatoid factors and anti-cyclic citrullinated peptides antibodies were elevated. He was suspected to have rheumatoid meningitis. We treated him with intravenous methylprednisolone (0.5 g/day) for 3 days. Rheumatoid meningitis often shows hyperintensity of the subarachnoid space on the DWI and FLAIR, and steroid therapy is effective.

A Descending Circuit Derived From the Superior Colliculus Modulates Vibrissal Movements.

The superior colliculus (SC) is an essential structure for the control of eye movements. In rodents, the SC is also considered to play an important role in whisking behavior, in which animals actively move their vibrissae (mechanosensors) to gather tactile information about the space around them during exploration. We investigated how the SC contributes to vibrissal movement control. We found that when the SC was unilaterally lesioned, the resting position of the vibrissae shifted backward on the side contralateral to the lesion. The unilateral SC lesion also induced an increase in the whisking amplitude on the contralateral side. To explore the anatomical basis for SC involvement in vibrissal movement control, we then quantitatively evaluated axonal projections from the SC to the brainstem using neuronal labeling with a virus vector. Neurons of the SC mainly sent axons to the contralateral side in the lower brainstem. We found that the facial nucleus received input directly from the SC, and that the descending projections from the SC also reached the intermediate reticular formation and pre-Bötzinger complex, which are both considered to contain neural oscillators generating rhythmic movements of the vibrissae. Together, these results indicate the existence of a neural circuit in which the SC modulates vibrissal movements mainly on the contralateral side, via direct connections to motoneurons, and via indirect connections including the central pattern generators.

Projection Patterns of Corticofugal Neurons Associated with Vibrissa Movement.

Rodents actively whisk their vibrissae, which, when they come in contact with surrounding objects, enables rodents to gather spatial information about the environment. Cortical motor command of whisking is crucial for the control of vibrissa movement. Using awake and head-fixed rats, we investigated the correlations between axonal projection patterns and firing properties in identified layer 5 neurons in the motor cortex, which are associated with vibrissa movement. We found that cortical neurons that sent axons to the brainstem fired preferentially during large-amplitude vibrissa movements and that corticocallosal neurons exhibited a high firing rate during small vibrissa movements or during a quiet state. The differences between these two corticofugal circuits may be related to the mechanisms of motor-associated information processing.

Shaping somatosensory responses in awake rats: cortical modulation of thalamic neurons.

Massive corticothalamic afferents originating from layer 6a of primary sensory cortical areas modulate sensory responsiveness of thalamocortical neurons and are pivotal for shifting neuronal firing between burst and tonic modes. The influence of the corticothalamic pathways on the firing mode and sensory gain of thalamic neurons has only been extensively examined in anesthetized animals, but has yet to be established in the awake state. We made lesions of the rat barrel cortex and on the following day recorded responses of single thalamocortical and thalamic reticular neurons to a single vibrissal deflection in the somatosensory system during wakefulness. Our results showed that the cortical lesions shifted the response of thalamic neurons towards bursting, elevated the response probability and the gain of thalamocortical neurons, predominantly of recurring responses. In addition, after the lesions, the spontaneous activities of the vibrissa-responsive thalamic neurons, but not those of vibrissa-unresponsive cells, were typified by waxing-and-waning spindle-like rhythmic spiking with frequent bursting. In awake rats with intact cortex, identified layer 6a corticothalamic neurons responded to a single vibrissal deflection with short latencies that matched those of layer 4 neurons, strongly suggesting the existence of an immediate corticothalamic feedback. The present results show the importance of corticothalamic neurons in shaping thalamic activities during wakefulness.

Similarity in Neuronal Firing Regimes across Mammalian Species.

UNLABELLED: The architectonic subdivisions of the brain are believed to be functional modules, each processing parts of global functions. Previously, we showed that neurons in different regions operate in different firing regimes in monkeys. It is possible that firing regimes reflect differences in underlying information processing, and consequently the firing regimes in homologous regions across animal species might be similar. We analyzed neuronal spike trains recorded from behaving mice, rats, cats, and monkeys. The firing regularity differed systematically, with differences across regions in one species being greater than the differences in similar areas across species. Neuronal firing was consistently most regular in motor areas, nearly random in visual and prefrontal/medial prefrontal cortical areas, and bursting in the hippocampus in all animals examined. This suggests that firing regularity (or irregularity) plays a key role in neural computation in each functional subdivision, depending on the types of information being carried. SIGNIFICANCE STATEMENT: By analyzing neuronal spike trains recorded from mice, rats, cats, and monkeys, we found that different brain regions have intrinsically different firing regimes that are more similar in homologous areas across species than across areas in one species. Because different regions in the brain are specialized for different functions, the present finding suggests that the different activity regimes of neurons are important for supporting different functions, so that appropriate neuronal codes can be used for different modalities.

[Overlap case of Fisher syndrome and pharyngeal-cervical-brachial variant of Guillain-Barré syndrome].

A 29-year-old female developed diplopia, nasal voice and gait disturbance after an upper respiratory infection. On admission, she presented with bilateral external ophthalmoplegia, slight bilateral facial nerve palsy, dysarthria, dysphagia, cervical and brachial muscle weakness, ataxia and areflexia. She had serum anti-GT1a, anti-GQ1b and anti-galactocerebroside IgG antibodies. She was diagnosed with an overlap case of Fisher syndrome and pharyngeal-cervical-brachial variant of Guillain-Barré syndrome. Intravenous immunoglobulin therapy was effective for the ophthalmoplegia and ataxia, but did not improve the bilateral facial nerve palsy and brachial muscle weakness. The facial nerve palsy clearly worsened despite improvement in other symptoms, and therefore high-dose intravenous methylprednisolone therapy was added. The distinct response to treatment may be caused by different activity, production, clearance and reactivity to intravenous immunoglobulin of the autoantibodies. The present case suggests that treatment response and patterns of recovery differ according to the causative anti-ganglioside antibodies.

[Successful treatment of a case of steroid-dependent neuro-Sweet disease with dapsone].

A 35-year-old Japanese man was admitted to our hospital with recurrent meningoencephalitis of unknown etiology. He presented with fever, convulsions and loss of consciousness, which started at age 33. We diagnosed him with neuro-Sweet disease (NSD) based on human leukocyte antigen (HLA) B-54/Cwl positivity and neutrophilic infiltration into the dermis in a biopsied skin plaque. Intravenous methylprednisolone and oral prednisolone markedly improved his fever and CSF pleocytosis. Five years later he was again admitted to our hospital with high fever, oral aphthae and dull-red edematous plaques on the face and body. He was conscious, but he had neck stiffness, mild hyperreflexia in all limbs and an extensor plantar response. Laboratory tests revealed increased white blood cell, erythrocyte sedimentation rate (ESR) and C-reactive protein level. CSF analysis indicated mild pleocytosis. A skin biopsy from an edematous plaque revealed neurotrophils infiltrating the upper dermis. We treated him with intravenous methylprednisolone (1 g/day) for 3 days, followed by oral prednisolone (50 mg/day). His symptoms improved remarkably; however, he had recurrence of symptoms, such as fever, meningial irritation and oral aphtae, with attempted taper of prednisolone. We started treatment with dapsone (75 mg/day) in addition to prednisolone, and could taper oral prednisolone, without a relapse. However, because some mildly recurred with the tapering of dapson, we maintained dapsone treatment at 75 mg daily, added colchicine (1 mg/ day) and tapered only prednisolone. His symptoms were improved and no relapse has been observed. NSD is characterized by neurotrophic hyperactivation and infiltration of tissues. It is highly responsive to systemic corticosteroid therapy; however, some cases show frequent recurrences on tapering of corticosteroids. Dapsone is considered to prevent neurotrophic overactivity. In this case, dapsone was supposed to be effective to prevent reccurence of NSD upon tappering corticosteroids. Dapsone should be a therapeutic options for steroid-dependent NSD showing frequent recurrence.