Accumulation of multiple neurodegenerative disease-related proteins in familial frontotemporal lobar degeneration associated with granulin mutation

In 2006, mutations in the granulin gene were identified in patients with familial Frontotemporal Lobar Degeneration. Granulin transcript haploinsufficiency has been proposed as a disease mechanism that leads to the loss of functional progranulin protein. Granulin mutations were initially found in tau-negative patients, though recent findings indicate that these mutations are associated with other neurodegenerative disorders with tau pathology, including Alzheimer's disease and corticobasal degeneration. Moreover, a reduction in progranulin in tau transgenic mice is associated with increasing tau accumulation. To investigate the influence of a decline in progranulin protein on other forms of neurodegenerative-related protein accumulation, human granulin mutation cases were investigated by histochemical and biochemical analyses. Results showed a neuronal and glial tau accumulation in granulin mutation cases. Tau staining revealed neuronal pretangle forms and glial tau in both astrocytes and oligodendrocytes. Furthermore, phosphorylated α-synuclein-positive structures were also found in oligodendrocytes and the neuropil. Immunoblot analysis of fresh frozen brain tissues revealed that tau was present in the sarkosyl-insoluble fraction, and composed of three- and four-repeat tau isoforms, resembling Alzheimer's disease. Our data suggest that progranulin reduction might be the cause of multiple proteinopathies due to the accelerating accumulation of abnormal proteins including TDP-43 proteinopathy, tauopathy and α-synucleinopathy.

Emergence of Mycoplasma genitalium with clinically significant fluoroquinolone resistance conferred by amino acid changes both in GyrA and ParC in Japan

We observed fluoroquinolone treatment failures in 2 men with Mycoplasma genitalium-positive non-gonococcal urethritis in Japan. A fluoroquinolone regimen of sitafloxacin 100 mg twice daily for 7 days failed to eradicate M. genitalium. In both cases, M. genitalium had fluoroquinolone resistance-associated amino acid changes both in GyrA and ParC and a macrolide resistance-associated mutation in the 23S rRNA gene. The emergence of such multi-drug resistant strains can threaten antimicrobial chemotherapy for M. genitalium infections in Japan, because we will lose the first- (azithromycin) and second-line (sitafloxacin) antimicrobial agents to treat M. genitalium infections. We prescribed an extended minocycline regimen of minocycline 100 mg twice daily for 14 days for our patients, and the regimen was successful in eradicating the M. genitalium. The extended minocycline regimen might be an option that we can try when treating multi-drug resistant M. genitalium infections in clinical practice.

Clinical courses of herpes simplex virus-induced urethritis in men

We retrieved clinical data of 13 men having herpes simplex virus (HSV)-induced non-gonococcal urethritis (NGU) without visible herpetic lesions. They visited a clinic in Sendai, Japan, between April 2013 and December 2015. All the men complained of dysuria. Meatitis was observed in 9 of the 13 men. Mononuclear cells were observed in the urethral smears from 9 men. The 13 men were treated with azithromycin or sitafloxacin regimen. First-voided urine (FVU) specimens became negative for HSV in 8 of the 10 men who returned to the clinic after antibacterial treatment, and urethritis symptoms were alleviated. However, herpetic lesions were observed at the follow-up visits in 3 men, and 2 of them were still positive for HSV in their FVU. HSV could be a cause of acute urethritis without causing visible herpetic lesions. The shedding of HSV from the urethra would spontaneously cease with alleviation of urethritis symptoms in most cases of HSV-induced NGU without antiviral therapy. However, new herpetic lesions could be developed in some cases. Early antiviral therapy is beneficial for patients with HSV infections. The development of meatitis and the mononuclear cell response in the urethral smear could be helpful to diagnose HSV-induced NGU. Therefore, we should presumptively initiate anti-HSV therapy for patients with signs and symptoms suggestive of HSV-induced NGU at their first presentation.

Tau pathology in aged cynomolgus monkeys is progressive supranuclear palsy/corticobasal degeneration- but not Alzheimer disease-like -Ultrastructural mapping of tau by EDX

Concomitant deposition of amyloid -beta protein (Aβ) and neuronal tau as neurofibrillary tangles in the human brain is a hallmark of Alzheimer disease (AD). Because these deposits increase during normal aging, it has been proposed that aging brains may also undergo AD-like changes. To investigate the neuropathological changes that occur in the aging primate brain, we examined 21 brains of cynomolgus monkeys (7–36 years old) for Aβ- and tau-positive lesions. We found, 1) extensive deposition of Aβ in brains of cynomolgus monkeys over 25 years of age, 2) selective deposition of 4-repeat tau as pretangles in neurons, and as coiled body-like structures in oligodendroglia-like cells and astrocytes, 3) preferential distribution of tau in the basal ganglia and neocortex rather than the hippocampus, and 4) age-associated increases in 30–34 kDa AT8- and RD4-positive tau fragments in sarkosyl-insoluble fractions. We further labeled tau-positive structures using diaminobezidine enhanced with nickel, and visualized nickel-labeled structures by energy-dispersive X-ray (EDX) analysis of ultrathin sections. This allowed us to distinguish between nickel-labeled tau and background electron-dense structures, and we found that tau localized to 20–25 nm straight filaments in oligodendroglia-like cells and neurons. Our results indicate that the cytopathology and distribution of tau deposits in aged cynomolgus brains resemble those of progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD) rather than AD. Thus, even in the presence of Aβ, age-associated deposition of tau in non-human primates likely does not occur through AD-associated mechanisms.

Virulence of acute hepatopancreatic necrosis disease PirAB-like relies on secreted proteins not on gene copy number

AIMS

To investigate the virulence of the Vp_PirAB-like genes in Vibrio parahaemolyticus- acute hepatopancreatic necrosis disease (AHPND)-causing strain and the factors that are associated with the virulence level.

METHODS AND RESULTS

The virulence of Vp_PirAB-like was examined using a non-virulent strain FP11 of V. parahaemolyticus transformed with a plasmid harbouring Vp_PirAB-like genes and then it was used to challenge shrimp Litopenaeus vannamei and Marsupenaeus japonicus. Both species experienced 100% mortality at 10 days post infection. Analysis of a mutant strain (E1M), that was originally identified as virulent strain (E1) but lost its virulence to L. vannamei, revealed that it lacked a part of the Vp_PirA-like gene and all of the Vp_PirB-like gene. The copy numbers of Vp_PirA-like and Vp_PirB-like genes varied among virulent strains and were not correlated with their virulence. In Western blotting, Vp_PirA-like and Vp_PirB-like proteins were detected in both the cell lysate and the culture supernatant. The strongest intensity of detecting band in the culture supernatant was observed in the strain that caused the highest mortality. The V. parahaemolyticus AHPND-causing strain, unlike the human tdh-positive strain, did not show any enterotoxicity.

CONCLUSION

Vibrio parahaemolyticus AHPND-causing strains secrete the Vp_PirA-like and Vp_PirB-like proteins during the growing phase. The amount of secreted proteins affects the shrimp mortality.

SIGNIFICANCE AND IMPACT OF THE STUDY

The secreted proteins of Vp_PirAB-like are key factors of virulence in the V. parahaemolyticus AHPND-causing strain, but not gene copy.

Spontaneous Osteosarcoma in a Rabbit (Oryctolagus cuniculus)

A 6-year-old male cross-breed rabbit ( Oryctolagus cuniculus) was presented with lameness and severe swelling from the right shoulder to brachium. On 16-detector helical computed tomography images of the amputated right forelimb after being fixed in formalin, evident proliferative and destructive lesions of bone were observed. On histologic examination, the tumor was composed of proliferating neoplastic cells that resembled histiocytes, with abundant osteoid production. A large number of multinucleated giant cells were found throughout. This case was diagnosed as osteosarcoma by clinical, radiographic, and histologic findings. This is a rare case report of osteosarcoma in a rabbit consistent with canine predilection sites.

Sleep disturbances and quality of life in patients after living donor liver transplantation

BACKGROUND

Following improvements in patient and graft survival after liver transplantation (LT), the recipients' quality of life has become an important focus of patient care. Sleep is closely related to physical and mental health; however, sleep disturbances in LT patients have not yet been evaluated.

METHODS

We assessed 59 LT patients (aged ≥18 years) between September 2011 and September 2012. The patients completed the restless legs syndrome (RLS), 36-item short-form health survey (SF-36), Pittsburgh Sleep Quality Index (PSQI), and Epworth Sleepiness Scale (ESS) questionnaires. In addition, laboratory data were obtained and neuropsychological tests (NPT) were performed during study entry.

RESULTS

Thirty-eight patients (64%) were included in the poor sleep group (PSQI ≥6 or ESS ≥10). The SF-36 scores were lower in the poor sleep group than in the good sleep group. Eleven patients (18%) had RLS. An NPT score ≥3 indicated minimal hepatic encephalopathy (MHE3). The MHE3 group consisted of 22 patients (43%). The time after LT was shorter; serum albumin, branched chain amino acid/tyrosine molar ratio (BTR), and role limitations due to poor physical health were lower; and serum ammonia levels were higher in the MHE3 group than in the MHE0-2 group. When the poor sleep group was divided into subgroups (control, MHE, RLS, and unknown), MHE patients had high model for end-stage liver disease scores, high ammonia levels, and low BTR, whereas RLS patients showed a short time after LT.

CONCLUSION

Sixty-four percent of recipients were classified as poor sleepers. SF-36 scores were lower for poor sleepers than good sleepers. RLS and MHE are major diseases that cause sleep disturbances in patients after LT.