An observational study of once-weekly carfilzomib in patients with multiple myeloma in Japan (Weekly-CAR study).

Background: The ARROW study demonstrated that once-weekly carfilzomib and dexamethasone (wKd) therapy significantly prolonged progression-free survival compared with twice-weekly carfilzomib and dexamethasone therapy in relapsed or refractory multiple myeloma patients. Aim: To describe the treatment patterns, effectiveness and safety of wKd therapy in real-world settings in Japan. Methods: We investigated data from the medical records of 126 Japanese patients with relapsed or refractory multiple myeloma. Results: The overall response rate was 66.3%. The median progression-free survival was 9.5 months. The incidence of treatment-emergent adverse events of any grade and grade ≥3 were 45.8 and 20.8%, respectively. Conclusion: There were no new or unexpected safety signals in this study. This study demonstrated the effectiveness and safety profiles of wKd therapy in Japan.

Carfilzomib became available for daily clinical practice as a drug for cancer of bone marrow (multiple myeloma) that comes back or does not respond to previous drug (relapsed or refractory). This drug was approved in the USA in 2012, and in Japan in 2016. In this study, we looked at how once-weekly carfilzomib works and how safe it is in real-life situations in Japan. We screened 126 patients with relapsed or refractory multiple myeloma in Japan. The median age of the patients was 70 years, with 25% being over 75 years. This study also included some patients who were not in the best overall health, had a history of many treatments or had heart complications. In 66.3% of patients, the cancer had disappeared or the extent of the cancer had reduced after treatment. Side effects and serious side effects occurred in 45.8 and 14.2% of patients, respectively. The most common side effects were low levels of blood platelets (9.2%), high blood pressure (5.8%), loose or watery stools (5.0%), fever (5.0%), and low levels of red blood cells (4.2%). Heart disorders occurred in five patients. But all patients recovered or improved with treatment such as blood pressure lowering drugs and diuretics. These results showed that once-weekly carfilzomib works well and is safe in real-world settings in Japan. This information can help us think about how to pick the right patients and handle heart disease risks when using carfilzomib treatment.

[Successful treatment of pure red cell aplasia with cyclosporin in a patient with T-cell large granular lymphocytic leukemia harboring the STAT3 D661V mutation].

T-cell large granular lymphocyte (T-LGL) leukemia is a chronic T-cell monoclonal disease that is occasionally associated with pure red cell aplasia (PRCA). A 71-year-old previously healthy man complained of physical fatigue and exhibited anemia (hemoglobin, 10.5 g/dl) with lymphocytosis (76%) showing LGL. The LGL cells expressed CD3, CD7, CD8, and T-cell receptor (TCR) -α/ß. TCR-ß/γ gene rearrangement was positive. He was thus diagnosed with CD8＋ T-LGL leukemia. Anemia progressed with low reticulocyte count (0.11%), and the patient became blood transfusion-dependent, but no distinct abnormality caused the anemia. Bone marrow aspiration revealed an increase in lymphocytes (33.6%) and a decrease in erythroblasts (M/E ratio, 6.1). He was thus diagnosed with T-LGL-associated PRCA. Oral cyclosporin A administration resulted in prompt improvement of anemia, suggesting its high sensitivity. Whole-exome sequencing of his peripheral blood DNA revealed somatic mutations in 33 genes, including the STAT3 gene, implying their roles in T-LGL leukemia.

Ant-mediated indirect negative effects of aphids on spider mites living on the same plant.

Some aphid species are known to have mutualistic relationships with tending ants; that is, the aphids supply the ants with honeydew and are protected by the ants. Although spider mites and honeydew-producing aphids often live on the same host plant, it has not previously been determined whether the ants tending these aphids affect spider mite survival. Using replicated microcosms, each containing an artificial ant nest, we compared experimentally the survival of two-spotted spider mites on kidney bean plants with and without cowpea aphids. Our results showed significantly fewer spider mites on plants with aphids, indicating that spider mites were preyed upon by ants tending aphids. On the other hand, there was no detectable plant-mediated indirect effect of aphids on mite performance in the microcosms. Therefore, we conclude that aphids indirectly reduced the survival of spider mites living on the same host plant via their tending ants. Nonetheless, spider mites did not avoid settling on plant leaves infested with aphids.

Myelodysplastic syndrome diagnosed on the occasion of Fournier's gangrene.

Fournier's gangrene (FG) is a fulminant infective necrotizing fasciitis, which includes the genital, perineal, and perianal regions. A 77-year-old man had previously been diagnosed as having diabetes mellitus (DM) and was treated with pioglitazone (15 mg) and miglitol (150 mg). He developed sudden perineal discomfort, fever with painful penile, and scrotal edema, subsequently leading to urinary retention. According to physical examination and CT scan results for the swollen penis and scrotum, he was diagnosed with FG. FG was eventually controlled by extensive treatment with broad spectrum antibiotics and repeated surgical debridement including penectomy and scrotectomy. He showed persistent anemia and decreased neutrophils exhibiting hypogranulation. Bone marrow aspiration revealed hypercellularity with 9% myeloblasts, micromegakaryocytes, abnormal leukocyte granulation, and erythrocytic dyspoiesis, leading to a diagnosis of myelodysplastic syndrome (MDS) RAEB-1, and he was evaluated as high risk according to IPSS-R. After 4 courses of azacitidine treatment, he achieved HI-E and had no further recurrence of FG for more than 18 months. Although DM and alcohol misuse are common systemic comorbidities in patients with FG, MDS should be considered in elderly FG cases, even when DM complications are present.

Characterization of coherence-or-power selectable operation of an external-cavity semiconductor diode laser.

The properties of the coherence-or-power selectable operation of an external-cavity semiconductor diode laser through the control of intracavity polarization states have been characterized in detail. In our technique, a diffraction grating and a reflector functioned as a polarization-dependent output coupler, such that the portion of light fed back to the gain medium was readily controlled by rotating the intracavity polarization axis, which resulted in the selectable operation of either a high degree of coherence or a high power for the laser output. We could continuously sweep the correlation widths over a range of approximately one order of magnitude, as well as four-fold output powers by simply rotating the intracavity half-wave plate. We also demonstrated experiments on optical phase locking, using two independent coherence-or-power selectable lasers.

Simultaneous occurrence of autoimmune hemolytic anemia and pure red cell aplasia.

Simultaneous onset of autoimmune hemolytic anemia (AIHA) and pure red cell aplasia (PRCA) is rare and any possible association between these two disorders remains obscure. A 46-year-old previously healthy woman was diagnosed as having AIHA based on severe anemia, positive direct and indirect Coomb's tests, decreased serum haptoglobin, elevated serum LDH, and indirect bilirubin-dominant hyperbilirubinemia. Oral steroid administration (1 mg/kg) and subsequent half-pulse steroid therapy ameliorated the AIHA, but the anemia was unexpectedly prolonged with the low peripheral blood reticulocyte count further decreasing to 0.11%. Bone marrow aspiration revealed a marked decrease in erythroblasts with an M/E ratio of 69.5. Anti-parvovirus B19 IgM antibody and serum B19 viral DNA (109 copy/ml) were detected but no other distinct abnormalities which might have caused acquired PRCA were detected. Therefore, she was considered likely to have idiopathic AIHA and acquired PRCA simultaneously. AIHA-mediated erythroblastosis probably raised the parvovirus B19 DNA level to an extraordinary degree and thereby led to severe aplastic crisis, subsequently causing prolonged anemia. Parvovirus B19 infection should be considered in AIHA patients showing unexpectedly low reticulocyte counts.

Heat stress activates ER stress signals which suppress the heat shock response, an effect occurring preferentially in the cortex in rats.

Although heat stress induces a variety of illnesses, there have been few studies designed to uncover the molecular mechanisms underlining the illnesses. We here demonstrate that heat activates ER stress, which inhibits heat shock responses (HSR) via translational block. In heat-stressed rats, ER stress responses, as represented by eIF2α phosphorylation and XBP1 splicing, occurred mainly in the cortex, where the HSR was substantially inhibited. Heat exposure also activated ER stress signals in primary cortical neurons. Since HSF1 knockdown enhanced heat-induced ER stress and subsequent cell death, HSR inhibition in turn augments ER stress, implying a vicious spiral of both stresses. Taken together, heat-induced ER stress impairs the HSR and enhances cell damage, thereby manifesting its unique effect on heat stress.

4-aminopyridine induces apoptosis of human acute myeloid leukemia cells via increasing [Ca2+]i through P2X7 receptor pathway.

4-AP, a voltage-gated potassium channel blocker, was identified to exert critical pro-apoptotic properties in various types of cancer cells. The present study aims to explore the effect of 4-AP on the apoptosis of human AML cells and the underlying mechanism. We found 4-AP inhibited the proliferation and induces apoptosis in both AML cell lines and primary cultured human AML cells. The apoptosis of AML cells after 4-AP treatment was further confirmed by the disruption of mitochondrial membrane potential (MMP) and activation of caspase 3 and 9. 4-AP inhibited Kv currents in NB(4), HL-60 and THP-1 cells. Furthermore, 4-AP induced significant increment in [Ca(2+)](i), which were inhibited by KN-62, a specific blocker of P(2)X(7) receptors. KN-62 also abrogated 4-AP induced apoptosis. Knockdown of P(2)X(7) receptor by small interfering RNA blocked the effect of 4-AP. Conclusively, this study indicated that 4-AP promotes apoptosis in human AML cells via increasing [Ca(2+)](i) through P(2)X(7) receptor.

2-methoxyestradiol, an endogenous mammalian metabolite, radiosensitizes colon carcinoma cells through c-Jun NH2-terminal kinase activation.

PURPOSE: 2-Methoxyestradiol (2ME), an estrogen metabolite, induces apoptosis in various cell types. We investigated whether 2ME pretreatment can radiosensitize colon adenocarcinoma cells. EXPERIMENTAL DESIGN: Radiosensitizing effects of 2ME were evaluated by cell death, clonogenic assay, nuclear fragmentation, and tumor progression of xenografts. Ionizing radiation-induced DNA damage was evaluated by histone H2AX phosphorylation and its foci. The c-Jun NH2-terminal kinase (JNK) activation was evaluated by anti-phosphorylated JNK antibody and inhibited by the JNK-specific inhibitor SP600125 or dominant-negative SEK1 expression. RESULTS: Clonogenic assays revealed that 2ME, but not estradiol, radiosensitized three colon carcinoma cells, DLD-1, HCT-8, and HCT-15, and strongly suppressed tumor progression of DLD-1 xenografts. Gene transfer-mediated Bcl-xL overexpression largely abolished both augmented apoptosis and reduced survival fractions. Pretreatment with 2ME enhanced H2AX phosphorylation, its foci, and phosphorylation of ATM kinase and delayed re-entry of cell cycle progression after ionizing radiation. Augmentation of both radiosensitivity and H2AX phosphorylation was substantially reduced by SP600125 or overexpression of a dominant-negative mutant SEK1. CONCLUSION: 2ME radiosensitized colon carcinoma cells through enhanced DNA damage via JNK activation, thereby representing a novel radiosensitizing therapy against colon cancer.

[Long-term survival after autologous peripheral blood stem cell transplantation in a patient with primary AL amyloidosis complicating congestive heart failure].

A 44-year-old man was admitted to hospital because of respiratory distress and progressive edema in the lower extremities. He was diagnosed as having congestive heart failure, but his condition improved following intensive care. Echocardiogram revealed a thickened interventricular septum, insufficient diastolic function, and granular sparkling pattern in the ventricular wall. Pathological examination of a myocardial biopsy specimen showed the deposition of AL amyloid, resulting in a diagnosis of AL amyloidosis. He was then referred to our hospital for treatment. After a course of high-dose dexamethasone therapy, peripheral blood stem cells induced by the administration of granulocyte colony stimulating factor were harvested. He then received high-dose melphalan (HDM) with autologous peripheral blood stem cell transplantation (auto-PBSCT) support, leading to complete remission. He has been well for more than three years after the transplantation and enjoys the same daily life as before the onset of symptoms. HDM/auto-PBSCT for AL amyloidosis confers a higher response rate and longer survival than conventional chemotherapies; however, treatment-related toxicity is also high. Refinements of treatment strategies are urgently needed. This case provides insights into appropriate strategies for HDM/auto-PBSCT for AL amyloidosis with regard to patient selection, the best induction therapy, and the risk-adjusted melphalan conditioning dose; all of which should be confirmed by randomized controlled trials.

Histone deacetylase inhibitors enhance phosphorylation of histone H2AX after ionizing radiation.

PURPOSE: Histone deacetylase (HDAC) inhibitors are believed to be promising radiosensitizers. To explore their effects on ionizing radiation (IR), we examined whether the HDAC inhibitors m-carboxycinnamic acid bis-hydroxamide (CBHA) and depsipeptide FK228 affect H2AX phosphorylation (gamma-H2AX), a landmark of DNA double-strand breaks after IR exposure. METHODS AND MATERIALS: We evaluated the effects of the HDAC inhibitors on clonogenic assay in human lung carcinoma A549 cells and progression of A549 xenograft tumors. IR-induced DNA damage was evaluated by histone gamma-H2AX. Histone hyperacetylation was induced by overexpression of histone acetyltransferase p300 and evaluated by Western blots. RESULTS: M-carboxycinnamic acid bishydroxyamide pretreatment radiosensitized A549 cells and strongly inhibited A549 xenograft tumor progression. CBHA and FK228, but not 5-fluorouracil, enhanced IR-induced gamma-H2AX in A549 and other cancer cell lines. Overexpression of p300 similarly augmented IR-induced gamma-H2AX. CONCLUSION: The results of this study suggest that HDAC inhibitors enhance IR-induced gamma-H2AX, most likely through histone hyperacetylation, and radiosensitize various cancers.

Sulindac enhances the proteasome inhibitor bortezomib-mediated oxidative stress and anticancer activity.

PURPOSE: The nonsteroidal antiinflammatory drug sulindac is a promising chemopreventive agent against colon cancer. Here, we address whether sulindac enhances the anticancer effects of the proteasome inhibitor bortezomib (PS-341) in colon cancer cells. EXPERIMENTAL DESIGN: The synergistic effects of sulindac with bortezomib were evaluated by cell death, colony formation assay, DNA fragmentation, and tumor progression of DLD-1 xenografts. Reactive oxygen species (ROS) generation was detected using carboxy-H2DCFDA or dihydroethidium. Oxidative stress was evaluated by heme oxygenase-1 induction and stress-activated mitogen-activated protein kinases p38 and c-Jun-NH2-kinase phosphorylation. Oxidative DNA damage was evaluated by histone H2AX phosphorylation and accumulation of 8-hydroxy-2'-deoxyguanosine. RESULTS: Sulindac and its metabolites enhanced the anticancer effects of bortezomib in DLD-1 and BM314 colon cancer cells. Sulindac induced ROS generation and enhanced bortezomib-mediated oxidative stress and subsequent DNA damage. Their combined effects were highly sensitive to free radical scavengers L-N-acetylcysteine and alpha-tocopherol, but were much less sensitive to a p38 inhibitor SB203580. CONCLUSION: Sulindac synergistically augments the anticancer effects of bortezomib primarily through cooperative ROS generation and oxidative DNA damage, thereby representing a novel combination therapy against colon cancer.

Adenovirus-mediated gene transfer of caspase-8 sensitizes human adenocarcinoma cells to tumor necrosis factor-related apoptosis-inducing ligand.

Resistance to apoptosis has been implicated in the poor response of cancer cells to various anti-tumor agents. Caspase-8 is a family member of executioner caspases associated with tumor necrosis factor (TNF) family death receptors-mediated apoptotic signaling cascade. In this study, to specify caspase-8-mediated apoptotic activity, we examined the anti-tumor effect of adenoviral vector expressing caspase-8 (Adv-caspase-8) in combination with TNF-related apoptosis-inducing ligand (TRAIL) which induces specifically caspase-8 activation. First, we demonstrated that expression procaspase-8 is related to apoptosis sensitivity to TRAIL in pancreatic and colonic cancer cells. In human pancreatic cancer cell line Panc1 which demonstrates low expression of procaspase-8, Adv-caspase-8 transfection strongly augmented TRAIL-induced apoptosis. Adv-caspase-8 similarly enhanced the susceptibility of human colonic cancer cell line Colo320DM to TRAIL. These results suggest that Adv-caspase-8 may be a good combination partner of TRAIL and enables TRAIL to be a more potent anticancer agent in a wide range of adenocarcinoma cells which demonstrate low expression of caspase-8.

Synergistic effect of histone deacetylase inhibitors FK228 and m-carboxycinnamic acid bis-hydroxamide with proteasome inhibitors PSI and PS-341 against gastrointestinal adenocarcinoma cells.

PURPOSE: We investigated whether the histone deacetylase inhibitors m-carboxycinnamic acid bis-hydroxamide (CBHA) and a bicyclic depsipeptide, FK228, can enhance the anticancer effect of the proteasome inhibitors PSI and PS-341 in gastrointestinal carcinoma cells. EXPERIMENTAL DESIGN: The anticancer effect of CBHA or FK228 and PSI or PS-341 was evaluated by cell death, caspase-3 activity, externalization of phosphatidylserine and DNA fragmentation, and colony formation assay. Expression of apoptosis-related molecules and cell cycle regulatory molecules, as well as phosphorylation of p38 were investigated by immunoblots. Generation of reactive oxygen species (ROS) was detected by intracellular oxidation of 5- (and-6)-carboxy-2',7'-dichlorodihydrofluorescein diacetate. RESULTS: CBHA or FK228 plus PSI or PS-341 synergistically induced apoptosis in human colonic DLD-1 and gastric MKN45 carcinoma cell lines. CBHA or FK228, but not 5-fluorouracil, plus PS-341 strongly decreased plating efficiency of DLD-1 cells. FK228 elicited ROS generation, and the free radical scavenger l-N-acetylcysteine inhibited the synergistic anticancer effect of combined therapy. In addition, l-N-acetylcysteine inhibited the combined therapy-mediated elevation of a proapoptotic BH3-only protein Bim expression, phosphorylation of H2AX, and accumulation of 8-hydroxydeoxyguanosine. CONCLUSIONS: FK228 or CBHA and PSI or PS-341 synergistically induce apoptosis in DLD-1 and MKN45 cells depending on ROS-mediated signals. Our data suggest that a combination of FK228 or CBHA with PSI or PS-341 may be a valuable therapy against gastrointestinal adenocarcinoma cells.

[Effective combination therapy of bortezomib and dexamethasone for two patients with refractory multiple myeloma].

We describe 2 cases of conventional therapy-resistant multiple myeloma (MM) that responded to bortezomib and dexamethasone therapy. Case 1: A 62-year-old woman with MM (IgG, kappa-type, stage IIIA) resistant to DMVM-IFN (dexamethasone, ranimustine, vincristine, melphalan, interferon-a), VAD (vincristine, doxorubicin, dexamethasone), high-dose melphalan with autologous peripheral blood stem cell transplantation (PBSCT) and thalidomide, received 2 courses of bortezomib treatment. In the first course, bortezomib alone was administered and then in the second course bortezomib was given in combination with dexamethasone. The patient's serum IgG level decreased from 8040 to 1020 mg/dl and the level of plasma cells in bone marrow was 1.2% after the treatments. Adverse reactions including rash, anemia, and thrombocytopenia occurred in the first course; however, they were milder in the second course combined with dexamethasone. Case 2: A 43-year-old man with MM (IgD, gamma-type, stage IIA) resistant to conventional and high-dose chemotherapy with PBSCT as well as thalidomide therapy, received treatment with bortezomib alone and then in combination with dexamethasone. His serum IgD level decreased from 2140 to 623 mg/dl. He suffered adverse reactions such as fatigue, anemia, and thrombocytopenia in the first course, which were relieved in the second course. These results indicate that the combination of bortezomib and dexamethasone is effective in the treatment of refractory MM and that dexamethasone can reduce the adverse reactions of bortezomib.

Interaction between the antigen and antibody is controlled by the constant domains: normal mode dynamics of the HEL-HyHEL-10 complex.

The antigen binding fragment (Fab) of a monoclonal antibody (HyHEL-10) consists of variable domains (Fv) and constant domains (CL-CH1). Normal modes have been calculated from the three-dimensional structures of hen egg lysozyme (HEL) with Fab, those of HEL with Fv, and so on. Only a small structural change was found between HEL-Fab and HEL-Fv complexes. However, HEL-Fv had a one order of magnitude lower dissociation constant than HEL-Fab. The Calpha fluctuations of HEL-Fab differed from those of HEL-Fv with normal mode calculation, and the dynamics can be thought to be related to the protein-protein interactions. CL-CH1 may have influence not only around local interfaces between CL-CH1 and Fv, but also around the interacting regions between HEL and Fv, which are longitudinally distant. Eighteen water molecules were found in HEL-Fv around the interface between HEL and Fv compared with one water molecule in HEL-Fab. These solvent molecules may occupy the holes and channels, which may occur due to imperfect complementarity of the complex. Therefore, the suppression of atomic vibration around the interface between Fv and HEL can be thought to be related to favorable and compact interface formation by complete desolvation. It is suggested that the ability to control the antigen-antibody affinity is obtained from modifying the CL-CH1. The second upper loop in the constant domain of the light chain (UL2-CL), which is a conserved gene in several light chains, showed the most remarkable fluctuation changes. UL2-CL could play an important role and could be attractive for modification in protein engineering.

Accumulation of Hsp70/Hsc70 molecular chaperone regulator BAG-1 on COPI-coated structures in gastric epithelial cells.

The multifunctional protein BAG-1 binds to molecular chaperones Hsc70/Hsp70 and regulates their activity. While a role for BAG-1 in regulating Hsc70 chaperone activity is firmly established in vitro, physiological roles of this regulation remain obscure. Here we show that BAG-1 is highly expressed in gastrointestinal epithelial cells and accumulates at the Golgi apparatus, probably through interaction with COPI coated structure. Subcellular fractionation of gastric mucosa revealed that BAG-1 was mainly recovered in the Golgi-enriched fractions. Confocal immunofluorescence studies revealed that BAG-1 was overlapped with a cis-Golgi matrix protein GM130 and a COPI component beta-COP in the vicinity of the Golgi. In response to brefeldin A, which blocks recruitment of COPI coats to the Golgi membrane, BAG-1 was dispersed throughout the cytoplasm as beta-COP was. Extensive overlap of BAG-1 immunofluorescence with beta-COP was still observed when cells were treated with nocodazole, which depolymerizes microtubules and induces fragmentation of the Golgi stacks. Immunoelectron microscopy revealed that BAG-1 signals were predominantly found on vesicular membrane structures adjacent to Golgi stacks, but not on mitochondrial membrane. Taken together, we suggest that BAG-1 is targeted to the COPI coated structures, implying its contribution toward the COPI vesicular transport in gastrointestinal epithelial cells.

Combination of tumor necrosis factor-alpha with sulindac in human carcinoma cells in vivo.

Transcription factor NF-kappaB plays a pivotal role in cancer cells in the resistance to apoptosis, since NF-kappaB is frequently activated in many primary carcinoma cells. Indeed, several NF-kappaB inhibitors are found to be promising anti-cancer agents. However, some anti-cancer agents activate NF-kappaB signals and may reduce their potential, including tumor necrosis factor (TNF)-alpha. Recently, the nonsteroidal anti-inflammatory drug (NSAID) sulindac and its metabolites have been shown to inhibit the NF-kappaB-mediated survival signals through inhibition of IKK-beta by their direct interaction. We thus investigate whether sulindac and its metabolite can augment TNF-alpha-mediated apoptosis in human carcinoma cells and be applicable for in vivo clinical usage. We here demonstrate that sulindac inhibited TNF-alpha-mediated NF-kappaB activation and greatly enhanced TNF-alpha-induced apoptosis in human gastric MKN45 and cervical HeLa carcinoma cell lines. The in vivo tumor growth of MKN45 cells was most strongly inhibited by a combination of TNF-alpha with sulindac compared with TNF-alpha or sulindac alone. Moreover, we demonstrate that sulindac sulfide further augmented TNF-alpha-mediated apoptosis. Our data strongly suggest that combination therapy of TNF-alpha with sulindac and its metabolites may sensitize cancer cells to TNF-alpha and augment its pro-apoptotic potential. Therefore, in combination with sulindac or its metabolites, TNF-alpha may become a potentially useful anti-cancer agent to suppress tumor.

Functional electrical stimulation of laryngeal adductor muscle restores mobility of vocal fold and improves voice sounds in cats with unilateral laryngeal paralysis.

Functional electrical stimulation (FES) has been proposed as a potential treatment for restoring motor functions of denervated motor systems. We investigated whether FES of paralyzed laryngeal adductor muscles could restore adduction to the vocal folds. In addition, we studied the effect of stimulated vocal fold adduction on the intensity and overall quality of voice production. We recorded movement of the vocal fold, electromyographic activity of muscles recruited for vocalization, and sound production in unanesthetized decerebrate cats during FES of the paralyzed thyroarytenoid (TA) muscle. FES of the paralyzed TA muscle induced adduction of the vocal fold. Appropriate stimulus parameters for induction was 1.5-3.0 mA intensity pulses delivered at a frequency of 30-50 pulses per second (pps). FES of the paralyzed TA muscle prolonged phonation time and increased intensity of voice sounds during vocalization induced by electrical stimulation (0.2 ms, 20-50 microA, 50 pps) of the periaqueductal gray (PAG). The quality of voice sounds evaluated by sound spectrography was shown to improve during vocalization with FES. We conclude that FES of the paralyzed laryngeal adductor muscle was effective in restoring adduction of the vocal fold and improving voice sounds impaired by unilateral laryngeal paralysis.

The neuronal circuit of augmenting effects on intrinsic laryngeal muscle activities induced by nasal air-jet stimulation in decerebrate cats.

We previously demonstrated that during nasal air-jet stimulation, both the activities of intrinsic laryngeal adductor and abductor muscles persistently increase, whereas the respiratory cycle prolongs and the activity of diaphragm decreases [Am. J. Rhinol. 9 (1995) 203-208; Neurosci. Res. 31 (1998) 137-146]. The purpose of this study was to clarify the neuronal circuit underlying the augmentation of intrinsic laryngeal muscles evoked by nasal air-jet stimulation. The immunohistologic analysis of Fos-expression was reported to determine the distribution of activated neurons in cat brainstem evoked by sneeze-inducing air puff stimulation of the nasal mucosa [Brain Res. 687 (1995) 143-154]. In sneezing cats, immunoreactivity was evoked in projection areas of the ethmoidal afferents, e.g. the subnuclei caudalis, interpolaris and in interstitial islands of the trigeminal sensory complex. Immunoreactivity was also enhanced in the solitary complex, the nucleus retroambiguus, the pontine parabrachial area and the lateral aspect of the parvocellular reticular formation [Brain Res. 687 (1995) 143-154]. In the present study, we focussed on the parvocellular reticular nucleus (PRN) as a relay of the neural circuit contributed to the augmentation of intrinsic laryngeal muscles evoked by nasal air-jet stimulation. We recorded the neuronal behavior of PRN during the nasal air-jet stimulation in precollicular-postmammillary decerebrate cats. As the results, 24% (17/71) of recorded neurons which were activated orthodromically by the electrical stimulation to anterior ethmoidal nerve, increased their firing rates in response to the nasal air-jet stimulation. Furthermore, spike-triggered averaging method revealed that four of these 17 PRN neurons activated intrinsic laryngeal muscles, suggesting that such neurons have excitatory projections to the intrinsic laryngeal muscle motoneurons in the nucleus ambiguus. These results suggest that the some of PRN neuron play a role in augmentation of the intrinsic laryngeal muscles activities during nasal air-jet stimulation.