Differential role of NSs genes in the neurovirulence of two genogroups of Akabane virus causing postnatal encephalomyelitis

Akabane virus (AKAV) is a member of the genus Orthobunyavirus, family Peribunyaviridae. In addition to AKAV strains that cause fetal Akabane disease, which is characterized by abortion in ruminants, some AKAV strains cause postnatal infection characterized by nonsuppurative encephalomyelitis in ruminants. Here, we focused on the NSs protein, a virulence factor for most viruses belonging to the genus Orthobunyavirus, and we hypothesized that this protein would act as a neurovirulence factor in AKAV strains causing postnatal encephalomyelitis. We generated AKAV strains that were unable to produce the NSs protein, derived from two different genogroups, genogroups I and II, and then examined the role of their NSs proteins by inoculating mice intracerebrally with these modified viruses. Our results revealed that the neurovirulence of genogroup II strains is dependent on the NSs protein, whereas that of genogroup I strains is independent of this protein. Notably, infection of primary cultured bovine cells with these viruses suggested that the NSs proteins of both genogroups suppress innate immune-related gene expression with equal efficiency. These results indicate differences in the determinants of virulence of orthobunyaviruses.

Generation and characterization of a genetically modified live rabies vaccine strain with attenuating mutations in multiple viral proteins and evaluation of its potency in dogs

Live rabies vaccines have advantageous features that can facilitate mass vaccination for dogs, the most important reservoirs/transmitters of rabies. However, some live vaccine strains have problems in their safety, namely, risks from the residual pathogenicity and the pathogenic reversion of live vaccine strains. The reverse genetics system of rabies virus provides a feasible option to improve the safety of a live vaccine strain by, for example, artificially introducing attenuating mutations into multiple viral proteins. It was previously demonstrated in separate studies that introduction of amino acid residues Leu at position 333 in the viral glycoprotein (G333), Ser at G194, and Leu/His at positions 273/394 in the nucleoprotein (N273/394) enhance the safety of a live vaccine strain. In this study, to test our hypothesis that combinational introduction of these residues would significantly increase the safety level of a vaccine strain, we generated a novel live vaccine candidate, ERA-NG2, that is attenuated by mutations at N273/394 and G194/333, and we examined its safety and immunogenicity in mice and dogs. ERA-NG2 did not cause any clinical signs in mice after intracerebral inoculation. After 10 passages in suckling mouse brains, ERA-NG2 retained all of the introduced mutations except the mutation at N394 and the highly attenuated phenotype. These findings indicate that the ERA-NG2 is highly and stably attenuated. After confirming that ERA-NG2 induced a virus-neutralizing antibody (VNA) response and protective immunity in mice, we immunized dogs intramuscularly with a single dose (10^5-7 focus-forming units) of ERA-NG2 and found that, at all of the tested doses, the strain induced a VNA response in dogs without inducing any clinical signs. These findings demonstrate that ERA-NG2 has a high level of safety and a substantial level of immunogenicity in dogs and thus is a promising live vaccine candidate that can facilitate vaccination in dogs.

Molecular characterisation of a novel avian rotavirus A strain detected from a gull species (Larus sp.)

A recent study demonstrated the possibility that migratory birds are responsible for the global spread of avian rotavirus A (RVA). However, little is known about what types of RVAs are retained in migratory birds. In this study, to obtain information on RVA strains in migratory birds, we characterised an RVA strain, Ho374, that was detected in a faecal sample from a gull species (Larus sp.). Genetic analysis revealed that all 11 genes of this strain were classified as new genotypes (G28-P[39]-I21-R14-C14-M13-A24-N14-T16-E21-H16). This clearly indicates that the genetic diversity of avian RVAs is greater than previously recognised. Our findings highlight the need for investigations of RVA strains retained in migratory birds, including gulls.

Improved method for avian influenza virus isolation from environmental water samples

Environmental water-targeted surveillance of migratory aquatic birds at overwintering sites is potentially one of the most effective approaches for understanding the ecology of avian influenza viruses (AIVs). In this study, we improved the method for AIV isolation from environmental water samples by making a minor modification to our previously reported process. We experimentally demonstrated that the AIV recovery efficiency of the modified method was 10-100-fold higher than that of the original method. This improved isolation method allowed us to isolate a considerably larger number of AIV isolates from environmental water samples collected at an overwintering site for tens of thousands of migratory aquatic birds in Japan during the 2018/19 winter season compared with those during previous winter seasons. Genetic and phylogenetic analyses revealed that AIVs of the same subtypes with multiple genetic constellations were circulating in a single overwintering site during a single winter season. These findings indicate that our improved isolation method contributes to enhance environmental water-targeted surveillance and to a better understanding of AIV ecology in migratory aquatic bird populations by monitoring ongoing AIV circulation. This article is protected by copyright. All rights reserved.

A frameshift variant in the EXT1 gene in a feline leukemia virus-negative cat with osteochondromatosis

Osteochondromatosis is a benign proliferative disorder characterized by cartilage-capped bony protuberances. In humans and most mammals, variants in the EXT1 or EXT2 gene are strongly correlated with the etiology of osteochondromatosis. However, in cats, osteochondromatosis has only been associated with feline leukemia virus infection. In this study, to explore other factors involved in the etiology of feline osteochondromatosis, we examined the EXT1 and EXT2 genes in a feline leukemia virus-negative cat with osteochondromatosis. Genetic analysis revealed a heterozygous single base pair duplication in exon 6 of the EXT1 gene (XM_023248762.2:c.1468dupC), leading to a premature stop codon in the EXT1 protein. Notably, this frameshift variant is recognized as one of the most common pathogenic variants in human osteochondromatosis. Our data suggest for the first time that genetic variants can have etiologic roles in osteochondromatosis in cats, as in humans and other animals.

Establishment of a reverse genetics system for avian rotavirus A strain PO-13

Avian rotavirus A (RVA) is one of major enteric pathogens that cause diarrhoea in young avian individuals. Importantly, some of the avian RVA strains of G18P[17] genotype are naturally transmitted to and cause clinical diseases in mammalian species, indicating their potential risks to animal health. Although molecular information on the pathogenesis by avian RVA strains will be useful for estimating their risks, the absence of a reverse genetics (RG) system for these strains has hindered the elucidation of their pathogenic mechanisms. In this study, we aimed to establish an RG system for the avian G18P[17] prototype strain PO-13, which was isolated from a pigeon in Japan in 1983 and was experimentally shown to be pathogenic in suckling mice. Transfection with plasmids expressing 11 genomic RNA segments of the strain resulted in rescue of the infectious virus with an artificially introduced genetic marker on its genome, indicating that an RG system for the PO-13 strain was successfully established. The rescued recombinant strain rPO-13 had biological properties almost identical to those of its wild-type strain (wtPO-13). Notably, both rPO-13 and wtPO-13 induced diarrhoea in suckling mice with similar efficiencies. It was thus demonstrated that the RG system will be useful for elucidating the pathogenic mechanisms of the PO-13 strain at the molecular level. This is the first report of the establishment of an RG system for an avian RVA strain.

Characterization of an avian rotavirus A strain isolated from a velvet scoter (Melanitta fusca): implication for the role of migratory birds in global spread of avian rotaviruses

Avian G18P[17] rotaviruses with similar complete genome constellation, including strains that showed pathogenicity in mammals, have been detected worldwide. However, it remains unclear how these strains spread geographically. In this study, to investigate the role of migratory birds in the dispersion of avian rotaviruses, we analysed whole genetic characters of the rotavirus strain RK1 that was isolated from a migratory species of birds [velvet scoter (Melanitta fusca)] in Japan in 1989. Genetic analyses revealed that the genotype constellation of the RK1 strain, G18-P[17]-I4-R4-C4-M4-A21-N4-T4-E4-H4, was highly consistent with those of other G18P[17] strains detected in various parts of the world, supporting the possibility that the G18P[17] strains spread via migratory birds that move over a wide area. Furthermore, the RK1 strain induced diarrhoea in suckling mice after oral gastric inoculation, indicating that at least some of the rotaviruses that originated from migratory birds are infectious to and pathogenic in mammals. In conclusion, it was demonstrated that migratory birds may contribute to the global spread of avian rotaviruses that are pathogenic in mammalian species.

Early detection of exacerbation of the severe acute respiratory syndrome coronavirus 2 infection using Fitbit (DEXTERITY pilot study)

 

Some patients with coronavirus disease 2019 (COVID-19) experienced sudden death because of sudden symptom deterioration. Thus, an alarm system that could detect early signs of COVID-19 exacerbation beforehand, to prevent serious illness or death of patients while receiving outpatient treatment at home or in hotels is necessary. Here, we tested whether estimated oxygen variations (EOV), a relative physiological scale that represents users' blood oxygen saturation level during sleep measured by Fitbit, predicted COVID-19 symptom exacerbation. Study period was from August to November 2020. We enrolled 23 COVID-19 patients diagnosed by SARS-CoV-2 polymerase chain reaction-positive (mean age ± standard deviation, 50.9±20 years; 70% female), let each patient wore the Fitbit for 30 days; COVID-19 symptoms were exacerbated in 6 (26%). High EOV signal (a patient's oxygen level exhibits significant dip and recovery within the index period) had 80% sensitivity before symptom exacerbations, whereas resting heart rate signal only had 50% sensitivity. Coincidental obstructive sleep apnea syndrome confirmed by polysomnography was detected in a patient by consistently high EOV signals. This pilot study successfully detected early COVID-19 symptoms exacerbation by measuring EOV and may help to identify early signs of COVID-19 exacerbation.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): The investigational device used in this study, Fitbit Charge 3, was provided by Fitbit Japan. Summary of high EOV signals and eventsThe clinical course of COVID-19

Analyses of cell death mechanisms related to amino acid substitution at position 95 in the rabies virus matrix protein

We previously reported that the avirulent fixed rabies virus strain Ni-CE induces a clear cytopathic effect in mouse neuroblastoma cells, whereas its virulent progenitor, the Nishigahara strain, does not. Infection with Nishigahara and Ni-CE mutants containing a single amino acid substitution in the matrix protein (M) demonstrated that the amino acid at position 95 of M (M95) is a cytopathic determinant. The characteristics of cell death induced by Ni-CE infection resemble those of apoptosis (rounded and shrunken cells, DNA fragmentation), but the intracellular signalling pathway for this process has not been fully investigated. In this study, we aimed to elucidate the mechanism by which M95 affects cell death induced by human neuroblastoma cell infection with the Nishigahara, Ni-CE and M95-mutated strains. We demonstrated that the Ni-CE strain induced DNA fragmentation, cell membrane disruption, exposure of phosphatidylserine (PS), activation of caspase-3/7 and anti-poly (ADP-ribose) polymerase 1 (PARP-1) cleavage, an early apoptosis indicator, whereas the Nishigahara strain did not induce DNA fragmentation, caspase-3/7 activation, cell membrane disruption, or PARP-1 cleavage, but did induce PS exposure. We also demonstrated that these characteristics were associated with M95 using M95-mutated strains. However, we found that Ni-CE induced cell death despite the presence of a caspase inhibitor, Z-VAD-FMK. In conclusion, our data suggest that M95 mutation-related cell death is caused by both the caspase-dependent and -independent pathways.

Detection and molecular characterization of Babesia sp. in wild boar (Sus scrofa) from western Japan

Wild animals often act as reservoirs of tick-borne Babesia and Theileria spp., which cause piroplasmosis. Therefore, epidemiological investigations about the distribution of these parasites in wild animals are important for evaluating the transmission risk to humans and livestock. In this study, we surveyed Babesia and Theileria spp. infecting wild boar (Sus scrofa) in Kagoshima and Yamaguchi prefectures and Tsushima island, which are all in western Japan, and performed molecular genetic analyses on the samples. DNA was extracted from either blood or liver samples of wild boar captured in Kagoshima prefecture in 2015, 2016, and 2018 and from blood samples from wild boar captured in Yamaguchi prefecture in 2013-2015 and Tsushima island in 2018. PCR screening for the partial 18S ribosomal RNA gene (18S rRNA) of both Babesia and Theileria spp. in wild boar revealed that 63.9 % (140 of 219 samples) were positive. Sequencing of all positive samples revealed that they were all the same Babesia species. Subsequent phylogenetic analyses showed that the parasite is closely related to Babesia sp. previously detected in the hard tick, Amblyomma testudinarium in Kagoshima, and further analyses suggested that this species is genetically related to Babesia gibsoni. On the other hand, no Theileria were detected in any of the samples. In summary, we observed a high prevalence of B. gibsoni-like Babesia sp. in wild boar in western regions of Japan. The host range, distribution, pathogenicity, and life cycle of this protozoan should be further evaluated.

Molecular detection of tick-borne protozoan parasites in sika deer (Cervus nippon) from western regions of Japan

The sika deer (Cervus nippon) is one of the most common species of wildlife in Japan. This study aimed to reveal the prevalence of tick-borne protozoan parasites in wild sika deer living in western Japan. We used nested polymerase chain reaction (PCR) to detect the 18S rRNA gene of tick-borne apicomplexan parasites (Babesia, Theileria, and Hepatozoon spp.) from 276 blood and liver samples from sika deer captured in the Yamaguchi, Oita, Kagoshima, Okayama, Ehime, Kochi, and Tokushima Prefectures. In total, 259 samples (259/276; 93.8%) tested positive in the nested PCR screening. Gene sequencing revealed that 99.6% (258/259) of positive samples contained Theileria sp. (sika 1), while Theileria sp. (sika 2), another Theileria species, was detected in only 3 samples. We also found that one sample from a sika deer captured in Kagoshima contained the gene of an unidentified Babesia sp. related to Babesia sp. Kh-Hj42, which was previously collected from tick in western Siberia. In conclusion, we found a high prevalence of piroplasms in sika deer from western Japan, and DNA analysis revealed that Theileria sp. (sika 1) had the highest infection rate.

Methodology of ECG Interpretation in the Nagoya Program

The outline of the Nagoya Program, the most representative software package for computerized electrocardiography in Japan, is described. First, the history and current status of research and its transfer to commercial products for computerized interpretation of electrocardiograms is briefly reviewed. Second, development and testing of the Nagoya Program is depicted, referring to a gold standard for evaluation and the database being used for this purpose, and to its participation in the CSE study. Third, a description of signal acquisition and wave identification is given, followed by the detection of rhythm disturbances. Next, algorithms for contour classification, which consist of decision-tree logic established through trial and error and making use of the database of ECGs, are described. Finally, special features and future plans of the Nagoya Program are mentioned.

Computational reconstruction of body surfact isopotential maps in myocardial infarction: comparison between nontransmural and transmural infarction

The relationship between the lack of electromotive force in myocardial infarction and body surface potential distribution was investigated on maps reconstructed from a simulated heart model and transfer impedance vectors of human torso model. The heart model, a cluster of 3-mm cubic blocks, was stored in the memory of a computer. Transfer impedance vectors between 81 lead points on the human torso model and 392 positions covering ventricular areas in the torso were measure. Body surface potential values were calculated mathematically by summing up scalar products between the electromotive force of the heart model and the measured transfer impedance vectors. Thus, reconstructed maps changed in their patterns with the alternation in lacation and/or extent of infarcted region in the heart model. In particular, the appearance of the abnormal potential minimum, which projects the infarcted region in the heart model onto the torso surface, was characteristic in both transmural and subendocardial infarction. In addition, delayed activation in the intact layer of the epicardium overlying the infarcted region produced a potential maximum on the same place as the abnormal potential minimum appeared previously.

Efficacy of endotoxin adsorption therapy (polymyxin B hemoperfusion) for methicillin-resistant Staphylococcus aureus toxic shock syndrome: a case report about five patients

BACKGROUND

Toxic shock syndrome (TSS), which can be life-threatening, is clinically and pathologically characterized by the presence of high fever, skin rash, desquamation, hypotension, and multiple organ failure caused by an enterotoxin produced by Staphylococcus aureus. In this study, we evaluated the effects of endotoxin adsorption therapy (polymyxin B [PMX] hemoperfusion) in critical patients with methicillin-resistant Staphylococcus aureus TSS (MRSA-TSS) who showed no improvement with the conventional therapy.

METHODS

Five MRSA-TSS patients (men/women: 3/2; median age: 39 years) who showed no improvement with the conventional therapy underwent PMX hemoperfusion in addition to the conventional therapy. The primary outcomes were change in the systolic arterial pressure (SAP) and requirement of a vasopressor after PMX hemoperfusion, and the secondary outcomes were change in laboratory data and sequential organ failure assessment (SOFA) scores 24 h after the therapy.

RESULTS

The median duration of PMX hemoperfusion was 9 h (range, 4-20 h). SAP significantly increased (from 89 to 125 mmHg, P<0.05) and the requirement of a vasopressor significantly decreased (from 10 to 2, P<0.05) after PMX hemoperfusion. Furthermore, the patients' white blood cell count decreased (from 17640 to 10090 /uL, P<0.05), and SOFA scores decreased (from 13 to 9, P<0.05) after PMX hemoperfusion. All patients recovered and were discharged from the ICU.

CONCLUSION

Our results showed that PMX hemoperfusion significantly improved the hemodynamics and severity in patients with life-threatening MRSA-TSS.

Single-incision laparoscopic colectomy using the Gelport system for early colon cancer

BACKGROUND

Laparoscopic surgery has spread quickly during the past twenty years, and has become one of the important treatments in the field of colorectal surgery. Recently, natural orifice transluminal endoscopic surgery (NOTES) has been studied as the next generation of minimally-invasive surgery, but the feasibility and safety of the NOTES method have not been evaluated. In such a situation, single-incision laparoscopic surgery has attracted interest from surgeons worldwide. However, single-incision laparoscopic colorectal surgery has not yet been standardized.

METHODS

From February 2010, single-incision laparoscopic colectomy was performed for 7 patients presenting with early colon cancer. All procedures were performed by two experts with the License of Endoscopic Surgical Skill Qualification System (ESSQS) of Japan Society for Endoscopic Surgery (JSES) in the field of colorectal Surgery.

RESULTS

We used the Gelport system (Applied Medical, Rancho Santa Margarita, CA, USA) as the access port and 3 trocars of different sizes (Ethicon, Inc., Cincinnati, OH, USA). Using this technique, we did not experience any difficulties or use any articulated instruments. All of the present 7 patients underwent the single-incision laparoscopic colectomy successfully and had no complications.

CONCLUSION

Single-incision laparoscopic surgery using the Gelport was performed safely in the present cases. The use of the Gelport as an access port can address the technical difficulty associated with this new technique.

Elimination of Teicoplanin by Adsorption to the Filter Membrane during Haemodiafiltration: Screening Experiments for Linezolid, Teicoplanin and Vancomycin followed by in vitro Haemodiafiltration Models for Teicoplanin

Pharmaceutical agents directed against methicillin-resistant Staphylococcus aureus can be eliminated during haemodiafiltration, not only by diffusion and ultrafiltration, but also by adsorption onto haemofilters. The latter may be affected by the binding of agents to serum albumin. The present study therefore investigated the affinity of anti-methicillin-resistant Staphylococcus aureus agents (teicoplanin, linezolid, vancomycin) for haemofilters and the pharmacokinetic properties of teicoplanin during haemodiafiltration. Linezolid, teicoplanin and vancomycin were first screened for their in vitro affinity for three different kinds of filter membranes: polysulfone, polyacrylonitrile and polymethylmethacrylate. Only teicoplanin showed significant filter-binding activity. An in vitro haemodiafiltration circulation model was then developed that incorporated a one-litre beaker containing Krebs-Ringer's bicarbonate solution with/without human albumin (0 or 3 g/dl) as an artificial plasma. Teicoplanin (initial concentration 50 μg/ml, representing the maximum plasma concentration (Cmax) resulting from a typical clinical dosage) was circulated throughout the beaker. Teicoplanin concentrations in the ‘plasma’ and ultrafiltrate were determined by high performance liquid chromatography. In the screening experiment, teicoplanin was predominantly adsorbed onto polysulfone and polymethylmethacrylate membranes. Furthermore, teicoplanin was primarily eliminated by adsorption onto these filters during in vitro haemodiafiltration. Albumin significantly reduced both haemodiafiltration clearance and the adsorption-dependent elimination, although there were complex but significant interactions between albumin and the filter membrane. Elimination of teicoplanin in an in vitro haemodiafiltration model was largely due to adsorption onto polysulfone and polymethylmethacrylate haemofilters. Future clinical studies should likely be designed to evaluate present recommendations of teicoplanin dosages in patients on haemodiafiltration.

In vitro bactericidal activity against periodontopathic bacteria by electrolyzed ion-reduced water

As typical periodontopathic bacteria, Porphyromonas gingivalis (P. gingivalis) and Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) were exposed to electrolyzed ion-reduced water (ERI) and ERI containing 1% sodium carboxymethylcellulose (CMC-Na) (ERI-1% CMC-Na), and the time course of their bactericidal action was evaluated. More than 99% of each bacteria species were killed after exposure to each solution for 15 sec. In addition, 1% CMC-Na, which was added to prolong bactericidal action, did not affect the bactericidal action of ERI. Its bactericidal action was concentration-dependent. No viable P. gingivalis bacteria were observed at a concentration of 15% of the undiluted solution and no viable A. actinomycetemcomitans bacteria were observed at a concentration of 50%, indicating differences in the bactericidal action of ERI for the two bacteria species. These results suggest that ERI may be extremely useful in preventing and treating periodontal diseases.

The treatment effect of the atopic dermatitis by electrolytic-reduction ion water lotion

A female in her late 20s was diagnosed with systemic atopic dermatitis in another hospital 5 years earlier and treated by steroid ointment application to the affected areas and oral steroid administration. She visited our hospital due to the aggravation of dermatitis symptoms over the entire face from 1 week earlier. Lesions were present on the face, chest, neck, and bilateral upper limbs, and, in particular, facial dermatitis was extensive. A diagnosis of systemic atopic dermatitis complicated by infection was made. As oral drugs, a herbal medicine and steroid/antihistamine combination tablet were used. As topical drugs, an steroid/antibiotic combination ointment and vitamin E/A ointment were applied. In addition, injections for the treatment of allergic disease were used, and acidic electrolyzed water and an electrolyticreduction ion water (ERI) lotion were topically applied. While receiving the two types of oral drug, she received a subcutaneous injection once a week and the application of acidic electrolyzed water, ERI lotion, steroid/antibiotic combination ointment, and vitamin E/A ointment to the lesions twice a day. One week after the initiation of treatment, redness and swelling decreased. After 1 month, the swelling further decreased, but the redness remained. After 1.5 months, the redness further decreased, showing a favorable course. Three months after the initiation of treatment, slight redness remained, but the skin color was almost normal. This patient showed the improvement of skin redness and swelling and an almost normal skin state without pigmented scars. These results suggest the effectiveness of complex therapy consisting of a herbal medicine and steroid/antihistamine combination drug as oral drugs and an steroid/antibiotic combination ointment and vitamin E/A ointment as topical drugs, injections for allergic disease, and acidic electrolyzed water and ERI lotion for disinfection and skin care.

Short disease-free interval is a significant risk factor for intrapulmonary recurrence after resection of pulmonary metastases in colorectal cancer

OBJECTIVE

Surgical resection has been the first choice of treatment for resectable pulmonary metastases from colorectal cancer. However, early intrapulmonary recurrence is often observed and appropriate assessment of prognostic factors is controversial. The aim of this study was to define the factors affecting survival and intrapulmonary recurrence after surgical treatment of metastatic pulmonary tumours from colorectal cancer.

METHOD

A retrospective analysis was performed of 56 consecutive patients who underwent pulmonary resection for colorectal metastases with a focus on prognostic factors and risk factors for intrapulmonary recurrence.

RESULTS

The overall 5-year survival rate was 48.2%. In a univariate analysis, a short disease-free interval (DFI), multiple pulmonary metastases and abnormal prethoracotomy carcinoembryonic antigen (CEA) levels were poor prognostic factors. In a multivariate analysis, a short DFI and abnormal prethoracotomy CEA levels were independent prognostic factors. Twenty-two (39.3%) of the 56 patients had recurrences in the remnant lung after resection for pulmonary metastases, and 8 (36.4%) of these 22 patients underwent repeated pulmonary resections. The median DFI between first and second lung metastasis was 13 months. Univariate analyses revealed that multiple and bilateral lung metastases were risk factors for intrapulmonary recurrence. There was also a strong correlation between the DFI for intrapulmonary recurrence after the first pulmonary resection and the DFI for first pulmonary metastases.

CONCLUSIONS

A short DFI was a risk factor for early tumour recurrence after resection for pulmonary metastases. The DFI might reflect oncological characteristics such as the tumour doubling time in colorectal cancer.

Analysis of T cell receptor Vbeta diversity in peripheral CD4 and CD8 T lymphocytes in patients with autoimmune thyroid diseases

Autoimmune thyroid diseases are characterized by intrathyroidal infiltration of CD4(+) and CD8(+) T lymphocytes reactive to self-thyroid antigens. Early studies analysing T cell receptor (TCR) Valpha gene usage have shown oligoclonal expansion of intrathyroidal T lymphocytes but not peripheral blood T cells. However, TCR Vbeta diversity of the isolated CD4(+) and CD8(+) T cell compartments in the peripheral blood has not been characterized fully in these patients. We performed complementarity-determining region 3 (CDR3) spectratyping as well as flow cytometric analysis for the TCR Vbeta repertoire in peripheral CD4(+) and CD8(+) T cells from 13 patients with Graves' disease and 17 patients with Hashimoto's thyroiditis. Polyclonal TCR Vbeta repertoire was demonstrated by flow cytometry in both diseases. In contrast, CDR3 spectratyping showed significantly higher skewing of TCR Vbeta in peripheral CD8(+) T cells but not CD4(+) T cells among patients with Hashimoto's thyroiditis compared with healthy adults. We found trends towards a more skewed CDR3 size distribution in those patients having disease longer than 5 years and requiring thyroid hormone replacement. Patients with Graves' disease exhibited no skewing both in CD4(+) and CD8(+) T cells. These findings indicate that clonal expansion of CD8(+) T cells in Hashimoto's thyroiditis can be detected in peripheral blood and may support the role of CD8(+) T cells in cell-mediated autoimmune attacks on the thyroid gland in Hashimoto's thyroiditis.

Rho-associated kinase inhibitor reduces tumor recurrence after liver transplantation in a rat hepatoma model

Tumor recurrence after liver transplantation still remains a significant problem in patients with hepatocellular carcinoma. The small GTPase Rho/Rho-associated kinase (ROCK) pathway is involved in the motility and invasiveness of cancer cells. We investigated whether tacrolimus activated the Rho/ROCK signal pathway to promote the invasiveness of rat hepatocellular carcinoma cells. We also investigated whether the ROCK inhibitor Y-27632 suppressed tumor recurrence after experimental liver transplantation in a rat hepatocellular carcinoma model. Orthotopic liver transplantation was performed in hepatocellular carcinoma cell line McA-RH7777-bearing rats. Tacrolimus was administered to liver transplant rats and these rats were divided into two groups: the Y-27632-treated (10 mg/kg, for 28 days) group and the Y-27632-untreated group. Tacrolimus enhanced the cancer cell migration and stimulated phosphorylation of the myosin light chain (MLC), a downstream effector of Rho/ROCK signaling. Y-27632 suppressed the cancer cell migration and tacrolimus-induced MLC phosphorylation. Suppression of tumor recurrence after liver transplantation and significant prolongation of survival were observed in the Y-27632-treated rats in comparison with theY-27632-untreated rats. Tacrolimus stimulates the Rho/ROCK signal pathway to enhance the invasiveness of hepatocellular carcinoma, and the ROCK inhibitor Y-27632 can be used as a new antimetastatic agent for the prevention of tumor recurrence after liver transplantation.

A groundbreaking new suturing device: the Excalibur

BACKGROUND

Laparoscopic knot tying can be stressful. We reported two simple techniques, known as the Thumbs up! knot and the Tornado knot. We have further refined these procedures with the development of a new needle holder, called the Excalibur suturing needle holder.

MATERIALS

This forceps differ from most conventional forceps in that the hinge is designed to stick out. The large hinge is stored out of the way when the forceps are closed, to prevent the thread accidentally catching.

RESULTS

The thread is hooked on the projected hinge, which resembles the heel of a high-heel shoe. By using this forceps, the laparoscopic knot tying becomes easier for not only well experienced but also less experienced surgeons.

CONCLUSIONS

The Excalibur, with its high heel, can complete knots with simple straight-line motion, making knot tying easier. This forceps will help reduce the stresses associated with intra-corporeal knot tying.

Multimedia article. The keys to the new laparoscopic world Thumbs up! knot and Tornado knot

Most laparoscopic surgeons feel some anxiety when performing intracorporeal knotting with conventional techniques [1, 2]. Two factors contribute to this anxiety. The first is the necessity of recognizing three dimensions on a two-dimensional monitor. The conventional intracorporeal knotting techniques make loops by twisting the thread with a second pair of forceps. This necessitates cooperative movement of both hands, with the added difficulties of depth perception. Regular touch confirmations reduce problems with depth perception. However, touch confirmation is more complicated in laparoscopic surgery than in laparotomy. The second problem is that tied loops can come loose and escape the instruments, especially with hard thread. This is not only stressful but also increases operation time.

Clinical usefulness of oral itraconazole, an antimycotic drug, for refractory atopic dermatitis

We investigated the clinical usefulness of oral itraconazole for refractory atopic dermatitis in a crossover study. Patients with refractory atopic dermatitis were divided into two groups: Group A; a combination of itraconazole plus a conventional lactobacillus preparation was administered for 8 weeks, followed by lactobacillus preparation alone for 8 weeks, Group B; lactobacillus preparation alone was administered for 8 weeks, followed by itraconazole plus lactobacillus for 8 weeks. In both groups, a decrease in dose or strength of concomitant topical steroids was observed at the end of the treatment course of itraconazole, and improvement of parameters such as eosinophil count, serum IgE level and specific IgE antibody titers to fungi was also observed after the administration of itraconazole. These results suggest that oral itraconazole is useful for the treatment of intractable atopic dermatitis patients who do not respond to conventional therapeutic approaches.

Improvement of macromolecular clearance via lymph flow in hamster gingiva by low-power carbon dioxide laser-irradiation

BACKGROUND AND OBJECTIVE

Although therapeutic effects of low-power laser-irradiation on periodontal disease have been reported, little is known about the biological effects of laser-irradiation in the gingiva. Recently we reported that topical warming stimulated macromolecular clearance via lymph flow in hamster gingiva. This study was conducted to investigate whether low-power laser-irradiation affects macromolecular clearance via the lymph flow in the gingiva.

STUDY DESIGN/MATERIALS AND METHODS

We injected 14C-methylated albumin into the mandibular gingiva of anesthetized hamsters followed by topical carbon dioxide (CO2) laser-irradiation (30 seconds, 0.5-1.5 W). We measured the clearance of radiolabeled albumin from the gingiva and its drainage into submandibular lymph nodes during 10 minutes.

RESULTS

The clearance of the radiolabeled albumin from the gingiva and the influx into the submandibular lymph nodes were increased by CO2 laser-irradiation.

CONCLUSION

Low-power CO2 laser-irradiation improves macromolecular clearance via the lymph flow in hamster gingiva.

Accumulation of beta-catenin protein and mutations in exon 3 of beta-catenin gene in gastrointestinal carcinoid tumor

The molecular basis of carcinogenesis in gastrointestinal carcinoid tumors is not well understood. To clarify the contribution of the Wnt/beta-catenin signaling to this type of carcinogenesis, we investigated 72 cases of gastrointestinal carcinoid tumor both immunohistochemically and by direct sequencing of beta-catenin. Accumulation of beta-catenin in the cytoplasm and/or nucleus was observed in 57 cases (79.2%). We also detected mutations in exon 3 of beta-catenin in 27 cases (37.5%) and one mutation in APC (1.4%). Our results suggest that alterations in the Wnt/beta-catenin signaling pathway may be involved in the development of gastrointestinal carcinoid tumors.

Duodenogastric reflux following cholecystectomy in the dog: role of antroduodenal motor function

BACKGROUND

Duodenogastric reflux has been implicated in the pathogenesis of gastric ulcer and gastritis. Duodenogastric reflux after cholecystectomy is also a possible cause of post-cholecystectomy syndrome.

AIM

To investigate the role of antroduodenal motor function in increased duodenogastric reflux following cholecystectomy and the effect of trimebutine maleate (trimebutine) on the duodenogastric reflux in conscious dogs.

METHODS

Antropyloric and duodenal motility and bile acids content in the gastric juice were measured for 3 h during the inter-digestive state in dogs with or without cholecystectomy.

RESULTS

Bile acids content in the gastric juice of cholecystectomized dogs was significantly higher than that of non-cholecystectomized dogs. The frequency of pyloric relaxation during phase II of the migrating motor complex was significantly increased following cholecystectomy. Intravenous infusion of trimebutine inhibited both the increased duodenogastric reflux and the frequency of pyloric relaxation in the cholecystectomized dog.

CONCLUSION

Duodenogastric reflux and frequency of pyloric relaxations were increased in cholecystectomized dogs and trimebutine suppressed both of them. These findings suggest that the increased frequency of pyloric relaxation contributes to the duodenogastric reflux following cholecystectomy.

Gasless hand-assisted laparoscopic surgery for colorectal cancer: an option for poor cardiopulmonary reserve

Gasless hand-assisted surgery, an alternative technique for colorectal cancer, is described. The abdomen is lifted by two metal disks especially designed for this procedure. The gasless condition evokes no hazard from pneumoperitoneum, and the procedure is greatly simplified by the hand assistance.

Lactate dehydrogenase isozymes in and intralesional steroid injection therapy for pseudocyst of the auricle

BACKGROUND

Various treatments for pseudocyst of the auricle have been reported. Recently, several patients have been treated successfully with steroid injections. The lactate dehydrogenase (LDH) levels of cystic fluid have been reported to be high, and the LDH-4 and LDH-5 isozymes were found to predominate, although the serum LDH levels and LDH isozyme patterns were normal.

OBJECTIVE

To find a way of preventing auricular pseudocyst recurrences after steroid injection therapy and to examine the relationships between recurrences and the LDH level and isozyme pattern of the cystic fluid.

METHODS

Steroid injection therapy was given to nine Japanese patients with pseudocyst of the auricle at our clinic between 1994 and 1999. We determined the LDH level and isozyme pattern of the cystic fluid and sera of seven patients.

RESULTS

All nine patients in this series were treated successfully with steroid injections, although three suffered recurrences. Although the serum LDH levels of seven patients were almost normal, their cystic fluid LDH levels were very high. LDH-4 and LDH-5 predominated in the cystic fluid of all seven, although their serum LDH isozyme patterns were virtually normal.

CONCLUSIONS

Auricular pseudocyst recurrences show no relationship with either the LDH levels or isozyme pattern. An undiluted solution of steroid fluid should be used in order to prevent recurrences.

[A case report of unresectable colon cancer that disappeared following pharmacokinetic modulation chemotherapy (PMC)]

We encountered a case of unresectable colon cancer that disappeared following pharmacokinetic modulating chemotherapy (PMC). A 41-year-old male underwent ileotransverse anastomosis following a diagnosis of ileus due to unresectable colon cancer with peritoneal dissemination and multiple liver metastases. He was treated weekly with an intravenous infusion of 5-FU, 1,000 mg/body/24 hours and an oral administration of UFT 400 mg/day (PMC). After 6 months of weekly treatment of PMC, colon tumor disappeared and metastatic liver tumors decreased in size. PMC can be administered to outpatients without serious side effects; thus, this therapy improves the prognosis and the patient's quality of life.