Characterization of Highly Pathogenic Avian Influenza Virus A(H5N6), Japan, November 2016

Highly pathogenic avian influenza viruses (HPAIVs) A(H5N6) were concurrently introduced into several distant regions of Japan in November 2016. These viruses were classified into the genetic clade 2.3.4.4c and were genetically closely related to H5N6 HPAIVs recently isolated in South Korea and China. In addition, these HPAIVs showed further antigenic drift.

Characterization of clade 2.3.4.4 H5N8 highly pathogenic avian influenza viruses from wild birds possessing atypical hemagglutinin polybasic cleavage sites

Since 2014, clade 2.3.4.4 H5 subtype highly pathogenic avian influenza viruses (HPAIVs) have been distributed worldwide. These viruses, which were reported to be highly virulent in chickens by intravenous inoculation, have a consensus HPAI motif PLRERRRKR at the HA cleavage site. However, two-clade 2.3.4.4 H5N8 viruses which we isolated from wild migratory birds in late 2014 in Japan possessed atypical HA cleavage sequences. A swan isolate, Tottori/C6, had a novel polybasic cleavage sequence, PLGERRRKR, and another isolate from a dead mandarin duck, Gifu/01, had a heterogeneous mixture of consensus PLRERRRKR and variant PLRERRRRKR sequences. The polybasic HA cleavage site is the prime virulence determinant of AIVs. Therefore, in the present study, we examined the pathogenicity of these H5N8 isolates in chickens by intravenous inoculation. When 10⁶ EID₅₀ of these viruses were intravenously inoculated into chickens, the mean death time associated with Tottori/C6 was substantially longer (>6.1 days) than that associated with Gifu/01 (2.5 days). These viruses had comparable abilities to replicate in tissue culture cells in the presence and absence of exogenous trypsin, but the growth of Tottori/C6 was hampered. These results indicate that the novel cleavage motif of Tottori/C6 did not directly affect the infectivity of the virus, but Tottori/C6 caused attenuated pathogenicity in chickens because of hampered replication efficiency. It is important to test for the emergence of diversified HPAIVs, because introduction of HPAIVs with a lower virulence like Tottori/C6 might hinder early detection of affected birds in poultry farms.

Cross-protective potential of anti-nucleoprotein human monoclonal antibodies against lethal influenza A virus infection

The nucleoprotein (NP) possesses regions that are highly conserved among influenza A viruses, and has therefore been one of the target viral proteins for development of a universal influenza vaccine. It has been expected that human or humanized antibodies will be made available for the prophylaxis, pre-emptive and acute treatment of viral infection. However, it is still unclear whether anti-NP human antibody can confer protection against influenza virus infection. In this study, we generated transgenic mice expressing anti-NP human mAbs derived from lymphocytes of a patient infected with H5N1 highly pathogenic avian influenza (HPAI) virus, and experimental infections were conducted to examine antiviral effects of the anti-NP antibodies against H5N1 HPAI viral infections with a high fatality rate in mammals. Transgenic mouse lines expressing the anti-NP human mAbs at more than 1 mg ml-1 showed marked resistance to H5N1 virus infections. In addition, resistance to infection with an H1N1 subtype that shows strong pathogenicity to mice was also confirmed. Although the anti-NP mAbs expressed in the transgenic mice did not neutralize the virus, the mAbs could bind to NP located on the surface of infected cells. These results suggested a possibility that the non-neutralizing anti-NP human mAbs could induce indirect antiviral effects, such as antibody-dependent cellular cytotoxicity or complement-dependent cytotoxicity. Taken together, these results demonstrated that anti-NP human mAbs play an important role in heterosubtypic protection against lethal influenza virus infections in vivo.

A metastatic haemangiopericytoma of the floor of the mouth

A case of metastatic haemangiopericytoma in the floor of the mouth is described. Haemangiopericytoma is a relatively rare slow-growing vascular tumour with variable malignant potential. This tumour has been identified in almost every region of the body, but its occurrence in the oral cavity has been rarely reported. The rate of regional and distant metastasis of the tumour is low. This case, presented 12 years after initial surgery suggested the need for careful long-term follow-ups of patients with haemangiopericytoma.

Usefulness of microspheres composed of gelatin with various cross-linking density

The release rate of insulin, as a model peptide, from gelatin microspheres (GM) prepared with gelatin having various cross-linking densities in vitro was examined. The release of insulin from GM showed the burst effect, followed by a slow release phase regardless of the cross-linking density of gelatin. The total amount of insulin released in 2 weeks decreased with increasing cross-linking density of gelatin. The release rate of insulin within 6 h was well correlated with the cross-linking density of gelatin. The remaining amounts of both insulin and GM after injection of insulin incorporated in GM to mice femoral muscle tissue were also examined in vivo. Both insulin and GM rapidly disappeared from the injection site within 1 day, and thereafter slowly disappeared over 14 days. The time courses of the remaining amounts were fairly similar to each other. Furthermore, the remaining amount of insulin 1 day after administration was well correlated with the cross-linking density of gelatin. These data suggest that insulin was released from GM with the degradation of GM in mice muscular tissue and that the release rate of insulin can be controlled by modifying the cross-linking density of gelatin. In conclusion, the control of the release rate of insulin from GM can be achieved under both in vitro and in vivo conditions by gelatin through the alteration of cross-linking conditions.

Evaluation of gelatin microspheres for nasal and intramuscular administrations of salmon calcitonin

The suitability of gelatin microspheres for nasal and intramuscular delivery of salmon calcitonin (sCT) was examined. Negatively and positively charged gelatin microspheres were prepared using acidic gelatin [isoelectric point (IEP) value of 5.0] and basic gelatin (IEP=9.0), respectively. The average diameters of positively charged gelatin microspheres in their dried state were 3.4, 11.2, 22.5 and 71.5 microm, while that of negatively charged gelatin microspheres was 10.9 microm. Both types of gelatin microspheres were capable of adhering to the nasal mucosa. The mucoadhesion of positively charged gelatin microspheres was significantly higher than that of their negatively charged counterparts. The absorption of sCT after intranasal and intramuscular administration was evaluated by calculating the area above the hypocalcemic-time curve (AAC) in rats. The AAC values after nasal administration of sCT in positively and negatively charged gelatin microspheres were significantly greater than that in pH 7.0 PBS. Therefore, the nasal absorption of sCT was enhanced by both types of gelatin microspheres. The hypocalcemic effect after administration of sCT in positively charged gelatin microspheres of 11.2 microm was significantly greater than that of negatively charged gelatin microspheres of the same size. On the other hand, AAC values were not affected by their particle sizes. The AAC values after the intramuscular administration of sCT in positively and negatively charged gelatin microspheres were significantly increased compared to that in PBS. Furthermore, the time-courses of the plasma calcium levels differed between positively and negatively charged gelatin microspheres. The hypocalcemic effect of the negatively charged gelatin microspheres tended to appear more slowly and last longer compared to that of positively charged gelatin microspheres. The hypocalcemic effects after intramuscular administration of sCT in gelatin microspheres were not affected by their particle sizes as well as those after intranasal administration. In conclusion, the gelatin microspheres have been shown to be a useful vehicle for nasal or intramuscular delivery of sCT.

[The evaluation of pamidronate therapy for bone metastases from breast cancer]

We devised a method to evaluate comprehensively the therapy to alleviate the pain of bone metastases from breast cancer according to the three items of bone pain and effects of analgesia and radiology. In 12 patients, we evaluated the therapeutic effect of pamidronate as an alleviative treatment for the pain of bone metastases from breast cancer. Bone pain was evaluated on a 6-grade scale, as was use of analgesics. Improvement in bone pain, in addition to improvement in use of analgesia, was evaluated as markedly improved, improved, unchanged, aggravated, no pain or undeterminable. Radiological improvement in bone lesions was evaluated as markedly improved, improved, unchanged, aggravated or undeterminable. An overall evaluation was made by combining the above two. In this evaluation method, pamidronate therapy resulted in an evaluation of markedly improved in 2 patients, improved in 5, unchanged in 4 and aggravated in 1, demonstrating that the therapy was very useful as an alleviative treatment for the pain of bone metastases from breast cancer. The evaluation method, in which pain, a subjective complaint, is combined with use of analgesics, an objective factor, and to which radiological evaluation is added for further objectively, may in the future to be applicable for evaluation of various alleviative treatments of pain of bone metastases.

[Chemotherapy with mitoxantrone for the treatment of recurrent breast cancer]

Two cases of recurrent breast cancer are reported in which chemotherapy with mitoxantrone proved remarkably effective. Case 1 was a 61-year-old postmenopausal female. At 32 postoperative months, multiple metastases of lung and bone were found. Following unsuccessful treatment with anthracyclin and an antiestrogenic agent, we used MVP modified therapy (mitoxantrone (MIT) 16 mg and vincristine (VCR) 1.6 mg once per 4 weeks and medroxyprogesterone acetate (MPA) 1,200 mg/day) and 5'-deoxy-5-fluorouridine (5'-DFUR) 800 mg/daily. After 12 cycles were performed, the patient showed a partial response (PR) (nearly complete response (CR)) on a chest X-ray and bone scintigram. Case 2 was a 49-year-old premenopausal female. At 42 postoperative months, a local recurrence was found and resection was performed. However, after endocrine therapy with goserelin acetate (ZOL) and chemotherapy with CAF (cyclophosphamide, adriamycin and 5-FU) and UFT, local recurrence and pleural effusion were found 6 months after surgical operation. We then used MVP modified chemotherapy and endocrine therapy with ZOL. The patient showed a PR at 9 cycles after therapy. MVP modified chemotherapy is considered an effective treatment for recurrent breast cancer, especially for adriamycin or epirubicin resistant breast cancer.

Gelatin microspheres as a pulmonary delivery system: evaluation of salmon calcitonin absorption

The use of negatively and positively charged gelatin microspheres for pulmonary delivery of salmon calcitonin was examined in rats. The microspheres were prepared using acidic gelatin (isoelectric point (IEP):, 5.0) and basic gelatin (IEP, 9.0) for the negatively and positively charged microspheres, respectively. The average diameters of positively charged gelatin microspheres in the dry state were 3.4, 11.2, 22.5 and 71.5 microm, and that of negatively charged gelatin microspheres was 10.9 microm. Neither positively nor negatively charged gelatin microspheres underwent any degradation in pH 7.0 PBS and there was less than 8% degradation in bronchoalveolar lavage fluid (BALF) after 8 h. In in-vitro release studies in pH 7.0 PBS, salmon calcitonin was rapidly released from positively charged gelatin microspheres within 2 h, and its cumulative release was approximately 85%. In addition, the release profiles were not influenced by particle sizes. The release rates of salmon calcitonin from negatively charged gelatin microspheres were lower than that from positively charged gelatin microspheres. The cumulative release was approximately 40% after 2 h, but there was no evidence of any sustained release. The pulmonary absorption of salmon calcitonin from gelatin microspheres was estimated by measuring its hypocalcaemic effect in rats. The pharmacological availability after administration of salmon calcitonin in positively and negatively charged gelatin microspheres was significantly higher than that in pH 7.0 PBS. The pharmacological availability after administration of salmon calcitonin in positively charged gelatin microspheres was significantly higher than that in negatively charged gelatin microspheres. Administration of salmon calcitonin in positively charged gelatin microspheres with smaller particle sizes led to a higher pharmacological availability. The pharmacological availability after pulmonary administration of salmon calcitonin in positively charged gelatin microspheres with particle sizes of 3.4 and 11.2 microm was approximately 50%. In conclusion, the gelatin microspheres have been shown to be a useful vehicle for pulmonary delivery of salmon calcitonin.

Excess loss of single-mode jacketed optical fiber at low temperature

This paper describes excess loss of single-mode jacketed optical fibers at low temperature. A structural model is proposed for the jacketed fiber in order to investigate the relationship between the structure and excess loss. This model clarifies the excess loss increase mechanism that any initial irregularity existing in the jacketed fiber increases due to shrinkage of the jacket and causes excess loss. These results show that reducing the buffer diameter and controlling the fiber deformation inside the jacket are effective in suppressing excess loss at low temperature.

Submarine optical fiber cable: development and laying results

This paper describes the structural design, trial production, and laying results for submarine optical fiber cables that can be deployed in shallow seas between islands and/or channel crossings without repeaters. Structural design methods for the submarine optical fiber cable are proposed, which take into consideration suppressing cable elongation under tension and excess loss under hydraulic pressure. This paper describes good laying results for the cable using this structural design method. The average loss for single-mode fibers was 0.72 dB/km, and the average loss for multimode fibers was 0.81 dB/km for a 10.2-km long cable operated at 1.3-microm wavelength.

Jacketed optical fiber characteristics under lateral pressure

Stress in an optical fiber has not been measured because of its small diameter. This paper explains the protective quality of a jacketed fiber from lateral pressure by a new experimental method, which enables the stress in the fiber to be measured using the photoelastic effect. Results show that the effect of the nylon jacket with a silicone rubber layer depends on the shell effect of the nylon jacket within its elastic deformation region and is so large that little lateral pressure is actually applied on the fiber. However, fiber stress and excess loss increase suddenly when the nylon jacket shell yields.