Successful treatment of a hemodialyzed patient with pure red cell aplasia associated with epoetin beta pegol therapy with cyclosporine.

A 42-year-old man with end-stage renal failure had been receiving hemodialysis therapy since April 2009. Initially, darbepoetin alfa was administered to treat his renal anemia. After treatment was switched to epoetin beta pegol, the patient's hemoglobin levels rapidly decreased. He was diagnosed with pure red cell aplasia (PRCA) based on the results of a bone marrow examination. Epoetin beta pegol was strongly suspected to be the cause of the PRCA, and although he tested negative for anti-epoetin beta pegol antibodies, epoetin beta pegol was discontinued and cyclosporine therapy was initiated. Thereafter, his hemoglobin levels increased, and his anemia dramatically improved after 3 months.

[Attempt to reduce the formaldehyde concentration by blowing cooled fresh air down in to the breathing zone of medical students from an admission port on the ceiling during gross anatomy class].

Cadavers in gross anatomy laboratories at most medical schools are conventionally embalmed in formaldehyde solution, which is carcinogenic to humans. Medical students and instructors are thus exposed to formaldehyde vapors emitted from cadavers during dissection. To reduce high formaldehyde concentrations in the breathing zone above cadavers being examined by anatomy medical students provisionally, dissection beds were located under existing admission ports on the ceiling to supply cooled fresh air from the admission port blowing downward on to the cadaver. In all cases, compared to normal condition, the downward flow of cooled fresh air from an admission port reduced formaldehyde concentrations by 0.09-0.98 ppm and reduced to 12.6-65.4% in the air above a cadaver in the breathing zone of students. The formaldehyde concentrations above cadavers under admission ports were not more than the formaldehyde concentrations between beds representing the indoor formaldehyde concentrations. Although the application of an existing admission port on the ceiling in this study did not remove formaldehyde, the downflow of cooled fresh air using this system reduced the formaldehyde concentration in the air above cadavers being attended by anatomy students during dissections. These results suggest the need for reducing formaldehyde levels in gross anatomy laboratories using fundamental countermeasures in order to satisfy the guidelines of 0.08 ppm established by the World Health Organization and the Japan Ministry of Health, Labor and Welfare.

[Vertical distribution of formaldehyde concentration and simulated temperature and wind velocity from computational fluid dynamics in a gross anatomy laboratory].

Cadavers for gross anatomy laboratories are typically embalmed in formaldehyde. Thus, medical students and instructors are exposed to formaldehyde vapors emitted from cadavers during dissection. In an attempt to improve the dissection environment, we examined indoor formaldehyde concentrations in a gross anatomy laboratory. Air samples were taken from 20, 110, 160, and 230 cm above the floor between dissection beds to represent areas near the floor, in the breathing zone of sitting students, in the breathing zone of standing students, and near the ceiling, respectively. Formaldehyde vapors were thoroughly diffused from the floor to the ceiling, suggesting that medical students are exposed to similar concentrations of formaldehyde based on distance from the floor. Computational fluid dynamics showed that cadavers are warmed by overhead fluorescent lights and the body heat of anatomy students, and indicated that the diffusion of formaldehyde vapors is increased by lighting and the body temperature of students. Computational fluid dynamics showed that gentle convection from anatomy students and cadavers carry formaldehyde vapors upward; downward flow near admission ports diffuse formaldehyde vapors from the ceiling to the floor in the anatomy laboratory.

[Formaldehyde concentrations in the breathing zone of medical students during gross anatomy laboratory in Toho University].

Cadavers for gross anatomy laboratories are conventionally embalmed by formaldehyde (FA) solution in most medical schools. Thus, medical students and instructors are exposed to FA vapors emitted from cadavers during dissection. As a basic survey for the improvement of the dissection environment, we examined FA concentration in the gross anatomy laboratory during the 2006 academic year at the Faculty of Medicine of Toho University. Air samples were taken from 20 cm above a cadaver as breathing zone, and above a desk between cadavers as indoor FA concentration. FA concentrations in the breathing zone were ranged from 0.24 to 3.04 (mean 1.71) ppm during systematic anatomy, and from 0.72 to 1.60 (mean 1.16) ppm during neuroanatomy, and indoor FA concentration ranged from 048 to 1.11 (mean 0.76) ppm and from 0.21 to 0.23 (mean 0.22) ppm, respectively. These results showed that medical students and instructors are exposed to higher concentrations of FA than allowed by the guidelines of the Japan Ministry of Health, Labor and Welfare, and suggested the need to reduce FA levels in the gross anatomy laboratory.

Preferential neuron loss in the rat piriform cortex following pilocarpine-induced status epilepticus.

Structures within the piriform cortex (PC) including the endopiriform nucleus (DEN) and pre-endopiriform nucleus (pEn) have been implicated to be involved in seizure genesis in models of temporal lobe epilepsy. We used stereological methods to examine the specificity and extent of neuron loss in the PC of pilocarpine-treated rats. Both 7 days and 2 months post-status epilepticus rats showed significant neuron loss in the pEn and DEN, layer III of the intermediate PC, and layers II and III of the caudal PC. Total losses in the PC were 40 and 46% in 7 days and 2 months post-status epilepticus rats, respectively (p<0.01). The numbers of parvalbumin (PV)- and cholecystokinin (CCK)-immunopositive neuron profiles significantly decreased, and somatostatin (SS)-immunopositive neuron profiles tended to decrease. A large decrease in the number of PV-immunopositive neuron profiles occurred in the pEn, adjoining parts of the DEN and deep layer III of the PC, portions of the DEN bordering the claustrum and agranular insular cortex, and layer III of the caudal PC. The regions with decreased numbers of PV-, CCK-, and SS-immunopositive neuron profiles overlapped with those where many Nissl-stained neurons were lost and many degenerating cell bodies were detected. These results suggest that the decreases in the numbers of PV/SS/CCK-immunopositive neurons are related to neuron loss rather than to a low rate of synthesis of their peptides or proteins.

Quantitative analysis of axon collaterals of single superficial pyramidal cells in layer IIb of the piriform cortex of the guinea pig.

To understand the functional organization of the piriform cortex (PC), the axon collaterals of three pyramidal cells in layer IIb of the anterior PC and one pyramidal cell in layer IIb of the posterior PC were labeled and quantitatively analyzed by intracellular biocytin injection in the guinea pig. Single pyramidal cells in the anterior and posterior PCs have widely distributed axon collaterals, which exhibit little tendency for patchy concentrations inside as well as outside the PC. The total lengths of the axon collaterals of the three fully analyzed pyramidal cells ranged from 68 to 156 mm, more than 50% of which were distributed in the PC. The total number of boutons of the three cells ranged from 6000 to 14,000, 5000-7000 of which were distributed in the PC. It was estimated that individual pyramidal cells in layer IIb form synaptic contacts with 2200 to 3000 other pyramidal cells in the PC, indicating that single pyramidal cells in layer IIb receive input from a large number of other pyramidal cells. This high connectivity of the network of pyramidal cells in the PC can be regarded as the neural network operating parallel distributed processing, which may play an important role in experience-induced enhancement in odorant discrimination in the PC.

Quantitative analysis of axon collaterals of single neurons in layer IIa of the piriform cortex of the guinea pig.

To study the various types of neurons in layer IIa in the piriform cortex (PC) and the spatial distribution of their axons, axon collaterals of three neurons in layer IIa were labeled and quantitatively analyzed by intracellular injection of biocytin in the guinea pig. Individual neurons have highly distributed axon collaterals, which display a little tendency toward patchy concentrations inside as well as outside the PC. One semilunar cell in the posterior PC had 54-mm-long axon collaterals and 4,200 boutons, out of which 2,100 (49% of the total number of boutons) were distributed in the PC. One semilunar-pyramidal transitional cell in the posterior PC had 256-mm-long axon collaterals and 23,000 boutons, out of which 16,100 (70% of the total number of boutons) and 4,000 (18% of the total number of boutons) were respectively distributed in all layers and in layer Ia of the PC. One multipolar cell in the posterior PC had 188-mm-long axon collaterals and 18,000 boutons, out of which 13,700 (78% of the total number of boutons) were distributed in the PC. Our results revealed that the connection patterns of individual cells in layer IIa have most of the features required for an associative neural network, which may function as a content-addressable memory for the association of odor stimuli.

Ultrastructure of ascending cholinergic terminals in the anteroventral thalamic nucleus of the rat: a comparison with the mammillothalamic terminals.

In this study, to identify the ultrastructure and distribution of ascending cholinergic afferent terminals in the anteroventral thalamic nucleus, we used an anti-vesicular acetylcholine transporter antibody as marker of cholinergic afferents, and characterized the immunoreactive terminals at the ultrastructural level. We then compared the distribution pattern of the cholinergic terminals and that of the mammillothalamic terminals identified by anterograde transport of a tracer injected into the mammillary body. The cholinergic terminals were small, and formed both symmetrical and asymmetrical synaptic contacts throughout the dendritic arborizations, particularly in the distal region. This distribution pattern differed from that of mammillothalamic terminals, that were of LR (large terminal containing round synaptic vesicles) type and were preferentially distributed in the proximal region of dendrites. We also found relatively numerous cholinergic terminals making contact directly with immunonegative excitatory terminals, both LR and SR (small terminal containing round vesicles) terminals, without clear postsynaptic specialization. A few cholinergic terminals even seemed to form a synaptic complex with the LR or SR terminals. These findings suggest that the ascending cholinergic afferents in the anteroventral thalamic nucleus can effectively modulate excitatory inputs from both the mammillothalamic and corticothalamic terminals, in close vicinity to a synaptic site.

Antiemetic effect of a tachykinin NK1 receptor antagonist GR205171 on cisplatin-induced early and delayed emesis in the pigeon.

Cisplatin (4 mg/kg, i.v.) induced both early emesis, which appears within the first 8-h period, and delayed emesis, which appears between 8 and 48 h after its administration to pigeons. GR205171 ([(2S-cis)-N-((2-methoxy-5(5-(trifluoromethyl)-1H-tetrazol-1-yl)-phenyl) methyl)-2-phenyl-3-piperidinamine dihydrochloride]) administered intramuscularly (1-10 mg/kg) reduced significantly the number of emetic response to cisplatin: this reduction was 60-81% (P < 0.05) for early emesis and 48-64% (P < 0.05) for the delayed response. Intracerebroventricularly administered GR205171 (30 microg/kg) also reduced the number of emetic responses: 53% (P < 0.05) in early emesis and 88% (P < 0.05) in the delayed response. However, the latency time to the first emesis was not affected by GR205171. Direct injection of cisplatin (10 microg/kg) into the fourth ventricle produced emesis, which was reduced by GR205171 administered via the peripheral or central route. Substance P-immunoreactive fibres were distributed throughout the dorsal vagal complex. These results suggest that the antiemetic effect of GR205171 on both emetic responses to cisplatin acts on a central site, and that the onset of the emetic response may be mediated partly via GR205171-insensitive mechanisms.

[Expression and localization of the inducible isoform of nitric oxide synthase in nasal polyps].

Nitric oxide (NO) and peroxynitrite play an important role in pathophysiology of several airway diseases. An inducible isoform of nitric oxide synthase (iNOS) is known to be expressed in the nasal mucosa in allergic and chronic rhinitis. Few reports exist, however, on the expression of iNOS in nasal polyps. We detected and localized iNOS expression in nasal polyp tissue. Nasal polyps were obtained from 10 patients following polypectomy, and divided into allergic and infectious groups based on clinical presentation and laboratory testing. One nasal mucosa of the inferior turbinate was also obtained from a cadaver without nasal disease. iNOS expression was studied by immunohistochemistry under light and electron microscopy. Immunoreactivity for iNOS was localized to the mucosal epithelium, inflammatory cells, vascular endothelium and smooth muscle, and nasal gland. Strong immunoreactivity was shown in the mucosal epithelium of both groups, and weak to moderate reactivity in the mucosal epithelium of the inferior turbinate. Vascular endothelium and smooth muscle of both groups sometimes showed weak to moderate immunoreactivity. Nasal glands of both groups sometimes showed weak immunoreactivity. A significant difference between allergic and infectious groups was observed in predominant types of inflammatory cells. Neutrophils were predominant in the infectious group (p < 0.01), and eosinophils in the allergic group (p < 0.0001). About 50%-53% in allergic and 42% in infectious groups--of inflammatory cells showed positive immunoreactivity for iNOS. Immunoreactive cells were neutrophils, eosinophils, and macrophages. Lymphocytes, plasma cells, and mast cells invariably reacted negatively. A significant difference between allergic and infectious groups was observed in predominant iNOS-immunoreactive cells. Ratios of immunoreactive neutrophils to all neutrophils (p < 0.05) and to all inflammatory cells (p < 0.05) were significantly higher in the infectious group. The ratio of immunoreactive eosinophils to all inflammatory cells was significantly higher in the allergic group (p < 0.0001), while the ratio of immunoreactive eosinophils to all eosinophils did not differ between infectious and allergic groups. The ratios of immunoreactive macrophages to all macrophages and to all inflammatory cells did not differ significantly between groups. Electron microscopy showed that degenerated cells with pyknotic nuclei were located next to immunoreactive eosinophils, suggesting the cytotoxicity of NO, peroxynitrite, or superoxide.

Origin and migration of interneurons of the olfactory bulb in the musk shrew, Suncus murinus.

The olfactory bulb of the musk shrew, Suncus murinus, is characterized by the presence of various interneurons. Our previous report (Kakuta et al., 2001) demonstrated that positive immunoreactions for calretinin were observed in periglomerular and perinidal cells in the glomerular layer, small ovoid neurons in the external plexiform layer, and granule cells in the granule cell layer of the olfactory bulb in the musk shrew aged 1 to 5 weeks, in addition to calretinin-immunoreactive bipolar cells distributed in the anterior subependymal layer and in each layer of the olfactory bulb. To examine the origin and migration of interneurons of the olfactory bulb, we labeled generated cells by injecting 28-day-old musk shrews with 5-bromo-2'-deoxyuridine (BrdU), and detected the labeled progeny cells that survived after several intervals. BrdU-labeled cells originated in the subependymal layer around the anterior horn of the lateral ventricle, and rostrally migrated in the subependymal layer from the anterior wall of the lateral ventricle into the center of the olfactory bulb, where they radially migrated into the granule cell layer, external plexiform layer, and glomerular layer. It took 2 days to migrate rostrally in the subependymal layer from the anterior lateral ventricle to the center of the olfactory bulb, and 2 to 6 days to migrate radially from the bulbar subependymal layer into the three layers mentioned. The rate of rostralward migration of the labeled cells was estimated to be 38 microm/h, while that of radial migration, 7 to 25 microm/h. The present BrdU-labeling study, together with our previous immunohistochemical study (Kakuta et al., 2001), indicates that anterior subependymal cells differentiate into granule cells in the granule cell layer, into Van Gehuchten cells in the external plexiform layer, and into periglomerular and perinidal cells in the glomerular layer of the olfactory bulb in the musk shrew.