Cigarette Smoke Delays Regeneration of the Olfactory Epithelium in Mice

The olfactory system is a unique part of the mammalian nervous system due to its capacity for neurogenesis and the replacement of degenerating receptor neurons. Cigarette smoking is a major cause of olfactory dysfunction. However, the mechanisms by which cigarette smoke impairs the regenerative olfactory receptor neurons (ORNs) remain unclear. Here, we investigated the influence of cigarette smoke on ORN regeneration following methimazole-induced ORN injury. Administration of methimazole caused detachment of the olfactory epithelium from the basement membrane and induced olfactory dysfunction, thus enabling us to analyze the process of ORN regeneration. We found that intranasal administration of cigarette smoke solution (CSS) suppressed the recovery of ORNs and olfaction following ORN injury. Defective ORN recovery in CSS-treated mice was not associated with any change in the number of SOX2(+) ORN progenitor cells in the basal layer of the OE, but was associated with impaired recovery of GAP43(+) immature ORNs. In the nasal mucosa, mRNA expression levels of neurotrophic factors such as brain-derived neurotrophic factor, neurotrophin-3, neurotrophin-5, glial cell-derived neurotrophic factor, and insulin-like growth factor-1 (IGF-1) were increased following OE injury, whereas CSS administration decreased the ORN injury-induced IGF-1 expression. Administration of recombinant human IGF-1 prevented the CSS-induced suppression of ORN recovery following injury. These results suggest that CSS impairs regeneration of ORNs by suppressing the development of immature ORNs from ORN progenitors, at least partly by reducing IGF-1 in the nasal mucosa.

Damage to Olfactory Progenitor Cells Is Involved in Cigarette Smoke-Induced Olfactory Dysfunction in Mice

Exposure to cigarette smoke is a major cause of olfactory dysfunction. However, the underlying mechanisms by which cigarette smoke interferes with the highly regenerative olfactory nerve system remain unclear. To investigate whether cigarette smoke induces olfactory dysfunction by disrupting cell proliferation and cell survival in the olfactory epithelium (OE), we developed a mouse model of smoking that involved intranasal administration of a cigarette smoke solution (CSS). Immunohistological analyses and behavioral testing showed that CSS administration during a period of 24 days reduced the number of olfactory marker protein-positive mature olfactory receptor neurons (ORNs) in the OE and induced olfactory dysfunction. These changes coincided with a reduction in the number of SOX2(+) ORN progenitors and Ki-67(+) proliferating cells in the basal layer of the OE, an increase in the number of caspase-3(+) apoptotic cells, and an increase in the expression of mRNA for the inflammatory cytokines IL-1β and IL-6. Notably, the proliferating ORN progenitor population recovered after cessation of treatment with CSS, resulting in the subsequent restoration of mature ORN numbers and olfaction. These results suggest that SOX2(+) ORN progenitors are targets of CSS-induced impairment of the OE, and that by damaging the ORN progenitor population and increasing ORN death, CSS exposure eventually overwhelms the regenerative capacity of the epithelium, resulting in reduced numbers of mature ORNs and olfactory dysfunction.

Recurrent cerebral aneurysm formation and rupture within a short period due to invasive aspergillosis of the nasal sinus; pathological analysis of the catastrophic clinical course

Destructive infiltration of invasive fungal sinusitis can easily occur into the central nervous system (CNS). Cerebral aneurysms associated with fungal infection are highly vulnerable to rupture, and can frequently and rapidly take a serious clinical course. We experienced a patient who twice developed cerebral aneurysm followed by rupture due to invasive fugal sinusitis. This 77-year-old man was admitted for progressive bilateral visual disturbance, which was initially treated as idiopathic hypertrophic pachymeningitis. The patient subsequently suffered subarachnoid hemorrhage (SAH) twice in only 12 days. Both SAH originated from different newly formed cerebral aneurysms. Trapping was performed for both ruptured aneurysms. Pathological examination of the resected aneurysms indicated the presence of fungi determined to be Aspergillus. This Aspergillus infection was also discovered inside the frontal sinus by endoscopic biopsy, so a regimen of antifungal agents was instituted. Prolonged antifungal therapy caused renal impairment, which ultimately led to the patient's death. Autopsy detected no mycotic infiltration of the major cerebral arteries, except for the 2 ruptured cerebral aneurysms. However, prolonged mycosis of the CNS, such as in the deep part in the falx cerebri and in the small veins proximal to the tentorium cerebelli, was observed, indicating that mycosis invading the cranium is refractory even to long-term administration of antifungal agents. The present case strongly suggests that urgent and proactive definitive diagnosis is essential to successfully treat invasive paranasal sinus aspergillosis. If infiltration of the CNS is suspected, early surgical resection and antifungal therapy must be initiated immediately.

Tumour necrosis factor inhibitor-associated sinusitis

AIM

To describe the features of chronic sinusitis associated with the use of tumour necrosis factor (TNF) inhibitors.

METHODOLOGY

A retrospective review of the medical records between 2003 and 2011 revealed that five patients had developed chronic sinusitis after the start of TNF inhibitor administration and required rhinological evaluation and treatment.

RESULTS

The incidence of refractory sinusitis associated with TNF inhibitors was approximately 2%. Of the five patients identified, four patients were medicated with etanercept and one with infliximab. The maxillary sinus was most commonly involved and cultures of the sinus discharge revealed Pseudomonas aeruginosa in three cases. Two patients showed improvement of sinusitis with antibiotic medication, despite the continuous use of TNF inhibitor, while in two other patients, sinusitis was resistant to antibiotic medication. Another patient who had developed recurrence of sinusitis after complete remission of previous chronic sinusitis by endoscopic sinus surgery showed remission only after cessation of TNF inhibitor.

CONCLUSION

Chronic sinusitis associated with TNF inhibitors is considered to be a new disease entity, and it will become more common due to the increasing use of TNF inhibitors.

Innate immune responses and neuroepithelial degeneration and regeneration in the mouse olfactory mucosa induced by intranasal administration of Poly(I:C)

The pathogenesis of postviral olfactory disorder (PVOD) has not been fully elucidated. We investigated morphological changes and innate immune responses in the mouse olfactory mucosa induced by intranasal administration of polyinosinic-polycytidylic acid [Poly(I:C)], a synthetic analog of viral double-stranded RNA. Mice received three administrations of saline with or without Poly(I:C), once every 24 h. The olfactory mucosa was harvested at various intervals after the first administration (8 h, 3, 9 and 24 days). In the Poly(I:C) group, the number of apoptotic cells in the olfactory neuroepithelium had increased at 8 h. At 9 days, the olfactory neuroepithelium had severely degenerated and behavioral tests demonstrated that the mice showed signs of olfactory deterioration. At 24 days, the structure of the neuroepithelium had regenerated almost completely. Regarding the innate immune responses, many neutrophils had infiltrated the olfactory neuroepithelium at 8 h and had exuded into the nasal cavity by 3 days. Macrophages had also infiltrated the olfactory neuroepithelium at 8 h although to a lesser extent, but they still remained in the neuroepithelium at 24 days. Poly(I:C)-induced neuroepithelial damage was significantly inhibited by a neutrophil elastase inhibitor and was suppressed in neutropenic model mice. These findings suggest that the secondary damage caused by the neutrophil-mediated innate immune response plays an important role in the pathogenesis of PVOD.

Odorant response properties of individual neurons in an olfactory glomerular module

Neuronal networks that are directly associated with glomeruli in the olfactory bulb are thought to comprise functional modules. However, this has not yet been experimentally proven. In this study, we explored the anatomical and functional architecture of glomerular modules using in vivo two-photon calcium imaging. Surprisingly, the deep portions of the glomerular modules showed considerable spatial overlap with other modules. Juxtaglomerular cells showed similar excitatory odorant response profiles to presynaptic olfactory sensory neuron inputs. Mitral cells exhibited a more sharply tuned molecular receptive range compared to juxtaglomerular cells, and their odorant response profiles varied depending on their interneuronal horizontal distances. These data suggest that glomerular modules are composed of functionally distinct neurons, and that homogenous odor inputs to each glomerulus may be parsed and processed in different fashions within the modules before being sent to higher olfactory centers.

The aggravating factors of hyperammonemia related to 5-fluorouracil infusion—A report of two cases

Hyperammonemia or hyperammonemic leukoencephalopathy sometimes occurs as an adverse event after 5-fluorouracil (5-FU) chemotherapy. The actual mechanism responsible for hyperammonemia by 5-FU administration is not known. Patient 1, a 48-year-old woman with cervical esophageal squamous cell carcinoma (SCC) presented with transient hyperammonemic leukoencephalopathy after undergoing combined chemotherapy (750mg/body/day of 5-FU for 5 days+100mg/body/day of cisplatin). Patient 2, a 58-year-old man with oropharyngeal and lower esophageal SCCs presented with hyperammonemia without leukoencephalopathy while undergoing combined chemotherapy (1200mg/body/day of 5-FU for 5 days+120mg/body/day of cisplatin). The neural symptoms of both patients improved after the termination of 5-FU administration and the early administration of fluid replacement. Ammonia can accumulate in the body when catabolism is insufficient because of an impairment in the urea cycle. The excess production of ammonium from 5-FU catabolites in addition to aggravating factors, e.g., renal dysfunction, constipation and body weight loss, may explain the transient hyperammonemia seen in the present two cases. The incidence of hyperammonemia by 5-FU administration will be one of the adverse events to need care in future and may be decreased by being aware of the presence of renal dysfunction, taking measures to prevent constipation, and nutritional management.

Factors associated with the presence of drug-resistant bacteria and recurrent acute otitis media in children--a study in a private clinic

CONCLUSIONS

The proportion of drug-resistant bacteria was lower than previous reports. In children with acute otitis media (AOM), lower age, presence of multiple bacteria, and otitis media with effusion (OME) represented significant factors for recurrent AOM and the presence of drug-resistant bacteria.

OBJECTIVE

Recently, the proportion of drug-resistant bacteria has been increasing in children with AOM. We studied the proportion of drug-resistant bacteria and background factors for detection of drug-resistant bacteria and recurrent AOM in a private clinic.

SUBJECTS AND METHODS

Subjects comprised 170 patients <12 years old with AOM. Middle ear fluid was collected and pathogenic bacteria were identified. The following factors were considered: age, sex, use of antibiotics in the past 1 month, past history of recurrent AOM, presence of OME, and multiple bacteria of the three main strains (Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis).

RESULTS

A total of 169 strains were detected in 77% of children with AOM. Drug-resistant bacteria comprised 44 of the 169 strains (26%). Lower age (p=0.001) and presence of multiple bacteria (p<0.001) represented significant factors for the presence of drug-resistant bacteria. OME was a significant factor for recurrent AOM (p<0.001).

X-ray diffraction with a Bragg angle near pi/2 and its applications

X-ray dynamical diffraction phenomena at a Bragg angle near pi/2 are studied. The X-ray transmissivity as well as the reflectivity from the (991) lattice plane of a silicon thin plate is observed. It agrees fairly well with the diffraction pattern calculated on the basis of the Darwin approach. The possibility is discussed whether a set of two crystal plates arranged face to face, in which the diffraction condition with a Bragg angle near pi/2 is satisfied, may be used as a very high resolution monochromator.

X-ray parametric scattering by a diamond crystal

Spontaneous X-ray parametric scattering from a diamond single crystal has been observed at the Photon Factory. The high perfection of the diamond single crystal and the small angular divergence of synchrotron radiation has enabled down-converted X-ray photon pairs to scatter into two small solid angles which satisfy the phase-matching condition. High-efficiency noise reduction was performed using avalanche photodiode detectors with good time resolution.

X-ray characterization of alpha-Fe(2)O(3) single crystals containing 2.2% and 95% (57)Fe

alpha-Fe(2)O(3) single crystals containing 2.2% and 95% (57)Fe isotopes were characterized by means of X-ray topography, the diffraction rocking curve and the integrated intensity. These crystals were revealed to be nearly perfect and suitable for a further nuclear-resonant Bragg-scattering study.

Two-photon correlations in X-rays from a synchrotron radiation source

The intensity correlation experiment using visible light performed by Hanbury Brown & Twiss [Nature (London) (1956), 177, 27-29] is extended to X-ray wavelengths. Correlations of 14.4 keV X-ray photons from a synchrotron radiation source are observed by the coincidence counting technique. The high brilliance of synchrotron radiation available in the Tristan main ring enables the observation of two-photon correlations with a reasonable measurement time.