Pth1r in Neural Crest Cells Regulates Nasal Cartilage Differentiation

Neural crest cells (NCC) arise from the dorsal margin of the neural plate border and comprise a unique cell population that migrates to and creates the craniofacial region. Although factors including Shh, Fgf8, and bone morphogenetic proteins have been shown to regulate these biological events, the role of parathyroid hormone 1 receptor (Pth1r) has been less studied. We generated an NCC-specific mouse model for Pth1r and researched gene expression, function, and interaction focusing on nasal cartilage framework and midfacial development. Wnt1-Cre;Pth1rfl/fl;Tomatofl/+ mice had perinatal lethality, but we observed short snout and jaws, tongue protrusion, reduced NCC-derived cranial length, increased mineralization in nasal septum and hyoid bones, and less bone mineralization at interfrontal suture in mutants at E18.5. Importantly, the mutant nasal septum and turbinate cartilage histologically revealed gradual, premature accelerated hypertrophic differentiation. We then studied the underlying molecular mechanisms by performing RNA seq analysis and unexpectedly found that expression of Ihh and related signaling molecules was enhanced in mutant nasomaxillary tissues. To see if Pth1r and Ihh signaling are associated, we generated a Wnt1-Cre; Ihhfl/fl;Pth1rfl/fl;Tomatofl/+ (DKO) mouse and compared the phenotypes to those of each single knockout mouse: Wnt1-Cre; Ihhfl/fl;Pth1rfl/+;Tomatofl/+ (Ihh-CKO) and Wnt1-Cre;Ihhfl/+;Pth1rfl/fl;Tomatofl/+ (Pth1r-CKO). Ihh-CKO mice displayed a milder effect. Of note, the excessive hypertrophic conversion of the nasal cartilage framework observed in Pth1r-CKO was somewhat rescued DKO embryos. Further, a half cAMP responsive element and the 4 similar sequences containing 2 mismatches were identified from the promoter to the first intron in Ihh gene. Gli1-CreERT2;Pth1rfl/fl;Tomatofl/+, a Pth1r-deficient model targeted in hedgehog responsive cells, demonstrated the enlarged hypertrophic layer and significantly more Tomato-positive chondrocytes accumulated in the nasal septum and ethmoidal endochondral ossification. Collectively, the data suggest a relevant Pth1r/Ihh interaction. Our findings obtained from novel mouse models for Pth1r signaling illuminate previously unknown aspects in craniofacial biology and development.

Metastatic renal cell carcinoma of the lumbar spine with long posterior instrumented fusion and repetitive dislodgement of the set screws of the S2 alar-iliac screw

Background

S2 alar-iliac screws (S2AIS) are widely used to anchor the pelvis to a lumbar fusion. Here, we report a patient who experienced repetitive dislodgement of the set screws of the S2AIS following a posterior instrumented fusion.

Case Description

A 68-year-old male presented with an L3 metastasis and L2-L3 subluxation attributed to renal cell cancer. Following an L2-L5 posterior decompression and T9-pelvic fusion utilizing bilateral S2AIS fixation, the set screws of the S2AIS repeatedly dislodged, requiring two additional operations. The final surgery required multiple anchors to the ilium and provided adequate fixation until the patient's expiration.

Conclusion

The set screw fixing force was weaker than the fixing force of the S2AIS; multiple iliac anchors effectively salvaged this condition.

Pth1r Signal in Gli1+ Cells Maintains Postnatal Cranial Base Synchondrosis

Cranial base synchondroses are the endochondral ossification centers for cranial base growth and thus indispensable for proper skull, brain, and midfacial development. The synchondroses are composed of mirror-image growth plates that are continuously maintained from the embryonic to postnatal stage through chondrocyte differentiation. Several factors, including Pth1r signaling, are known to control fetal synchondrosis development. However, there are currently no reports regarding any role for Pth1r signaling in postnatal cranial base and synchondrosis development. Also, the mesenchymal cells that source Pth1r signaling for synchondroses are not known. Here, we employed an inducible mouse model, a hedgehog-responsive Gli1-CreERT2 driver, focusing on the postnatal study. We performed 2 inducible protocols using Gli1-CreERT2;Tomatofl/+ mice that uncovered distinct patterning of Gli1-positive and Gli1-negative chondrocytes in the synchondrosis cartilage. Moreover, we generated Gli1-CreERT2;Pth1rfl/fl;Tomatofl/+ mice to assess their functions in postnatal synchondrosis and found that the mutants had survived postnatally. The mutant skulls morphologically presented unambiguous phenotypes where we noticed the shortened cranial base and premature synchondrosis closure. Histologically, gradual disorganization in mutant synchondroses caused an uncommon remaining central zone between hypertrophic zones on both sides while the successive differentiation of round, flat, and hypertrophic chondrocytes was observed in control sections. These mutant synchondroses disappeared and were finally replaced by bone. Of note, the mutant fusing synchondroses lost their characteristic patterning of Gli1-positive and Gli1-negative chondrocytes, suggesting that loss of Pth1r signaling alters the distribution of hedgehog-responsive chondrocytes. Moreover, we performed laser microdissection and RNA sequencing to characterize the flat proliferative and round resting chondrocytes where we found flat chondrocytes have a characteristic feature of both chondrocyte proliferation and maturation. Taken together, these data demonstrate that Pth1r signaling in Gli1-positive cells is essential for postnatal development and maintenance in cranial base synchondroses. Our findings will elucidate previously unknown aspects of Pth1r functions in cranial biology and development.

Atypical clinical and radiological presentations of lumbar spinal tuberculosis mimicking a spinal tumor: A case report

INTRODUCTION

Tuberculosis (TB) is an important infectious disease worldwide. Classical spinal TB has specific radiological findings involving adjacent vertebral bodies with destruction of the intervertebral disc and involvement of paravertebral soft tissues with cold abscess formation. However, a few cases not exhibiting the radiological characteristics of TB spondylitis have been reported. We report a rare case of lumbar spinal TB with atypical clinical and radiological presentations that was difficult to differentiate from a malignant spinal tumor.

PATIENT CONCERNS

A 21-year-old man, who had immigrated to Japan from the Philippines 5 years ago, without a significant medical history, presented with back pain lasting 1 month and progression of gait disturbance 2 weeks prior to presentation.

DIAGNOSIS

Laboratory tests showed normal blood cell counts and normal value of C-reactive protein levels. Preoperative imaging studies indicated a possible spinal tumor. However, histopathologic findings of the epidural soft tissues at the first surgery led to the diagnosis of spinal mycobacterial infection. The diagnosis of spinal TB was confirmed by a positive culture of Mycobacterium tuberculosis obtained at the second surgery.

INTERVENTIONS

Given the progressive nature of neurologic deterioration, instead of needle biopsy, we proceeded with surgical intervention 8 days after admission; simultaneous neural decompression and open biopsy. Histological findings of the excised epidural soft tissues led to the diagnosis of spinal mycobacterial infection. We performed the second surgery involving additional resection of epidural soft tissues for further dural decompression and to obtain specimens for mycobacterial culture. Immediately after the second surgery, the patient commenced combination therapy with anti-tuberculous drugs.

OUTCOMES

The patient demonstrated significant recovery of motor function in the lower extremities, and was able to run at 2 months after the second surgery. The epidural granulomas completely disappeared on magnetic resonance imaging 3 months postoperatively.

CONCLUSION

Atypical clinical and radiological presentations of spinal TB present a challenge for appropriate diagnosis and early treatment. Even in developed countries where there are very few spinal TB patients, clinicians should be aware that spinal TB is an important differential diagnosis, especially in elderly patients or patients coming from countries with a middle-high prevalence of TB.

Acute femoral osteomyelitis due to hypermucoviscous Klebsiella pneumonia

Hypervirulent hypermucoviscous Klebsiella pneumoniae strains have emerged as clinically important pathogens causing invasive infections. K. pneumoniae osteomyelitis is uncommon in adult patients, and may mimic bone tumors on presentation. We report a patient with left rectus femoris muscle abscess and acute osteomyelitis of the left femur due to hypermucoviscous K. pneumoniae with negative blood culture, who was initially thought to have left thigh tumor. The patient's infection resolved with surgical drainage and debridement and intravenous and antibiotic therapy.

Clinical features, risk factors, and prognosis of anthracycline-induced cardiotoxicity in patients with malignant lymphoma who received a CHOP like regimen

Background

Anthracycline-induced cardiotoxicity is a serious complication in patients with malignant lymphoma (ML) who received chemotherapy, which threatens life prognosis and quality of life of patients. However, incidence and risk factors of cardiotoxicity in patients with ML who undergo intensive chemotherapy which aims complete remission is not clarified. Furthermore, prognosis after cardiotoxicity and that after recovery from cardiotoxicity have not been elucidated.

Method

We screened 443 ML patients who received either rituximab (R)-CHOP or CHOP regimen between January 2008 and December 2017 at Nagoya City University Hospital. Two handled forty-four patients who underwent echocardiography before and after chemotherapy were enrolled and data were analyzed retrospectively. Cardiotoxicity was defined as a decline in left ventricular ejection fraction (LVEF) of 10% or greater and an LVEF was below 50%. Partial recovery was defined as a 5% or more of increase in LVEF and an LVEF was ≥50% after cardiotoxicity. Complete recovery was defined as an increase in LVEF became more than 95% of the baseline value. Patient's basic characteristics, chemotherapeutic regimen, laboratory data, echocardiographic data, and prognosis were collected from the medical records by two cardiologists and two hematologists.

Result

At baseline, the median age was 71 years, the median cumulative dose of doxorubicin was 302 mg/m2 and the median LVEF was 69%. During the follow-up period, cardiotoxicity was observed in 52 out of 244 patients (21%), 30 patients (12%) had a symptomatic heart failure, and 5 patients died from cardiovascular cause. Thirty-five patients developed cardiotoxicity during the first year of chemotherapy. Multivariate analysis identified that only the baseline LVEF (HR 0.949, 95% CI 0.919–0.981, p=0.002) was an independent risk factor for cardiotoxicity. In our study, patients who received more than 200 mg/m2 of doxorubicin developed cardiotoxicity frequently. Among 52 patients who experienced cardiotoxicity, partial recovery and full recovery were observed in 18 (35%) and 4 (8%) patients, respectively. Four patients without recovery died due to heart failure and 1 patient with partial recovery died suddenly. Six out of 18 patients with partial recovery developed re-cardiotoxicity.

Conclusion

ML patients who undergo more than 200 mg/m2 of doxorubicin need a watchful follow-up. Only a baseline LVEF was an independent risk factor for cardiotoxicity. one third of patients with partial recovery developed re-cardiotoxicity.

Funding Acknowledgement

Type of funding source: None

Positronium formation at 4H SiC(0001) surfaces

Positronium formation at 4H SiC(0001) surfaces were investigated upon the removal of natural oxide layers by hydrofluoric acid etching and heat treatment at 1000 K in ultra-high vacuum. Two types of positronium were observed in the positronium time-of-flight (PsTOF) measurements irrespective of conduction type and surface polarity. One type formed the major part of the PsTOF spectrum with a maximum energy of 4.7 ± 0.3 eV. This energy exceeded the theoretical value calculated with valence electrons. The PsTOF spectrum shape was different from those of metal surfaces, suggesting that the surface state electrons or conduction electrons need to be considered as the positronium source. Another positronium appeared at 1000 K in the tail of the PsTOF spectrum with a maximum energy of 0.2-0.5 eV. This thermally-assisted athermal positronium may be formed via the surface state positrons and electrons.

Cathepsin K inhibitor causes changes in crystallinity and crystal structure of newly-formed mandibular bone in rats

Cathepsin K inhibitors are new drugs with the potential for the treatment of osteoporosis because they sustain bony remodelling better than bone resorption inhibitors such as bisphosphonates. The treatment of osteoporosis with inhibitors of bony resorption is associated with osteonecrosis of the jaw, as the deterioration in bony quality that they induce is thought to be one of its causes. The quality of bone is delineated by structural and material characteristics (which include the degree and quality of mineralisation, and depends on the content of proteoglycan and the structural integrity of the bony collagen).^1,2 Animal and clinical studies have shown that cathepsin K inhibitors improve the mineral density and structural characteristics of bone, but their effect on the rest remains unknown. We therefore hypothesised that these inhibitors will affect the material characteristics of newly-formed mandibular bone. To verify our hypothesis, we used Raman microspectroscopy to examine such bone in rats that were given a cathepsin K inhibitor, and found unusual crystallinity and an increased substitution of carbonate (CO₃^2-) in its crystal structure.

Molecular alterations of newly formed mandibular bone caused by zoledronate

Bone quality is defined by structural and material characteristics. Most studies on the mandible have focused on the analysis of structural characteristics, with insufficient investigation of material characteristics. This study tested whether zoledronate affects the material characteristics of newly formed mandibular bone. Thirty-six female Wistar rats were assigned to three groups: sham-ovariectomized rats (SHAM, n=12), ovariectomized rats (OVX, n=12), and ovariectomized rats treated with zoledronate (ZOL, n=12). The left side of the mandibular ramus of all rats was drilled bicortically. Twenty-eight days after surgery, all surviving rats were euthanized and all mandibles were removed. Raman microspectroscopy was performed, and five spectra per specimen of newly formed mandibular bone were analysed. Compared with OVX rats, the mineral/matrix ratio in ZOL rats was significantly increased (5.43±1.88 vs. 7.86±2.05), while crystallinity (0.055±0.002 vs. 0.050±0.002), relative proteoglycan content (0.43±0.10 vs. 0.31±0.05), and collagen structural integrity (1.16±0.21 vs. 0.72±0.06) were significantly decreased. These changes in material characteristics may explain why rats that received zoledronate exhibited peculiar biological phenomena such as bisphosphonate-related osteonecrosis of the jaw.

Living Related Renal Transplantation Using a Saphenous Vein Graft: A Case Report

We report a case of living related renal transplantation that used the recipient's saphenous vein as a graft to extend the length of the right donor renal vein. A 41-year-old woman underwent ABO-incompatible living related renal transplantation from her 74-year-old mother in November 2014. A retroperitoneal laparoscopic right donor nephrectomy was performed, because the right kidney showed a cyst on preoperative computed tomography. As the right kidney after donor nephrectomy had a short renal vein and the kidney was large at 280 g, anastomosis with the external iliac vein was difficult. Therefore, we obtained the recipient's 15-cm-long right saphenous vein and created a 1 cm saphenous vein graft. We anastomosed 1 side of the saphenous vein graft to the allograft renal vein in bench surgery and performed end-to-side anastomosis of the other end to the recipient's external iliac vein. The allograft renal artery was used to perform end-to-end anastomosis to the recipient's internal iliac artery. Allograft kidney function was good after transplantation. When the longer axis of the renal graft vein is short, as in the right kidney, a saphenous vein graft may be useful.

Emission of low-energy positronium from alkali-metal coated single-crystal tungsten surfaces

We have measured the time-of-flight of ortho-positronium emitted from Cs-, Na- and Li-coated single-crystal tungsten surfaces. The data obtained after the coating show a new positronium energy component with a specific energy loss in addition to the component whose emission energy is simply determined by the positron and the electron work functions. We suggest that this new component is attributed to the formation of positronium accompanied by inter-band transition and/or surface plasmon excitation at the surfaces.

Nontumorous perfusion abnormalities of liver parenchyma adjacent to the falciform ligament as revealed by angiographic helical CT and angiography

Purpose: To investigate nontumorous abnormalities in the liver around the falciform ligament as revealed by arteriography and helical CT arterial portography (CTAP) and helical CT during hepatic arteriography (CTHA).

Material and Methods: One hundred and seventeen patients simultaneously underwent hepatic arteriography and CTAP and CTHA of the common hepatic artery. The number, size, and shape of nontumorous defects of portal perfusion in the liver adjacent to the falciform ligament on CTAP as well as the nontumorous contrast enhancement in the same area on CTHA were determined. In 1 case, in which nontumorous enhancement was observed on CTHA, selective arteriography from the gastric arteries was performed.

Results: On CTAP a nontumorous area of decreased portal perfusion of the liver around the falciform ligament was detected in 18 (15.4%) of the 117 patients, while nontumorous enhancement on CTHA was seen in 7 (6.0%). In 4 patients, both of these nontumorous abnormalities were observed. In the patient undergoing selective gastric arteriography, nonportal venous inflow to the liver in the direction to the liver adjacent to the falciform ligament was seen.

Conclusion: One cause of nontumorous vascular abnormalities adjacent to the falciform ligament as shown on angiographic helical CT is aberrant gastric venous inflow to this region.

Lower expression of activating transcription factors 3 and 4 correlates with shorter progression-free survival in multiple myeloma patients receiving bortezomib plus dexamethasone therapy

Bortezomib (BTZ), a proteasome inhibitor, is widely used in the treatment of multiple myeloma (MM), but a fraction of patients respond poorly to this agent. To identify factors predicting the duration of progression-free survival (PFS) of MM patients on BTZ treatment, the expression of proteasome and endoplasmic reticulum (ER) stress-related genes was quantified in primary samples from patients receiving a combination of BTZ and dexamethasone (BD). Fifty-six MM patients were stratified into a group with PFS<6 months (n=33) and a second group with PFS⩾6 months (n=23). Of the 15 genes analyzed, the expression of activating transcription factor 3 (ATF3) and ATF4 was significantly lower in patients with shorter PFS (P=0.0157 and P=0.0085, respectively). Chromatin immunoprecipitation analysis showed that these ATFs bind each other and transactivate genes encoding the pro-apoptotic transcription factors, CHOP and Noxa, which promote ER stress-associated apoptosis. When either ATF3 or ATF4 expression was silenced, MM cells partially lost sensitivity to BTZ treatment. This was accompanied by lower levels of Noxa, CHOP and DR5. Thus low basal expression of ATF3 and ATF4 may attenuate BTZ-induced apoptosis. Hence, ATF3 and ATF4 could potentially be used as biomarkers to predict efficacy of BD therapy in patients with MM.

A Pharmacokinetic/Pharmacodynamic Drug-Drug Interaction Study of Tofogliflozin (a New SGLT2 Inhibitor) and Selected Anti-Type 2 Diabetes Mellitus Drugs

OBJECTIVE

Tofogliflozin is an oral hypoglycemic agent with a novel mechanism of action that reduces blood glucose levels by promoting glucose excretion in urine, achieved by selectively inhibiting sodium-glucose co-transporter 2 (SGLT2). We evaluated the effects of several selected anti-type 2 diabetes mellitus (T2DM) drugs-glimepiride, metformin, sitagliptin, pioglitazone, miglitol, nateglinide, and voglibose-on the pharmacokinetics and pharmacodynamics of tofogliflozin, and the effects of tofogliflozin on the pharmacokinetics of these anti-T2DM drugs in healthy male volunteers.

METHODS

A single dose of either tofogliflozin alone, one of the anti-T2DM drugs alone, or co-administration of tofogliflozin and the anti-T2DM drug was administered to 108 healthy men. Cmax, AUCinf, and cumulative urine glucose excretion after co-administration of tofogliflozin and each of the anti-T2DM drugs was evaluated relative to the values of those parameters after administration of each drug alone.

RESULTS

None of the anti-T2DM drugs had any effect on tofogliflozin exposure. Tofogliflozin had no or little effect on the exposure of any anti-T2DM drug. No anti-T2DM drug had any major effect on the cumulative urine glucose excretion induced by tofogliflozin. There were no safety concerns evident after administration of any drug alone or in co-administration.

CONCLUSIONS

Neither the pharmacokinetics nor the pharmacodynamics of tofogliflozin was affected by any of the anti-T2DM drugs evaluated in this study, nor was the pharmacokinetics of any of the anti-T2DM drugs affected by tofogliflozin in healthy male volunteers.

Acute and chronic rejection: compartmentalization and kinetics of counterbalancing signals in cardiac transplants

Acute and chronic rejection impact distinct compartments of cardiac allografts. Intramyocardial mononuclear cell infiltrates define acute rejection, whereas chronic rejection affects large arteries. Hearts transplanted from male to female C57BL/6 mice undergo acute rejection with interstitial infiltrates at 2 weeks that resolve by 6 weeks when large arteries develop arteriopathy. These processes are dependent on T cells because no infiltrates developed in T cell-deficient mice and transfer of CD4 T cells restored T cell as well as macrophage infiltrates and ultimately neointima formation. Markers of inflammatory macrophages were up-regulated in the interstitium acutely and decreased as markers of wound healing macrophages increased chronically. Programmed cell death protein, a negative costimulator, and its ligand PDL1 were up-regulated in the interstitium during resolution of acute rejection. Blocking PDL1:PD1 interactions in the acute phase increased interstitial T cell infiltrates. Toll-like receptor (TLR) 4 and its endogenous ligand hyaluronan were increased in arteries with neointimal expansion. Injection of hyaluronan fragments increased intragraft production of chemokines. Our data indicate that negative costimulatory pathways are critical for the resolution of acute interstitial infiltrates. In the arterial compartment recognition of endogenous ligands including hyaluronan by the innate TLRs may support the progression of arteriopathy.

Eye movements during emotion recognition in faces

When distinguishing whether a face displays a certain emotion, some regions of the face may contain more useful information than others. Here we ask whether people differentially attend to distinct regions of a face when judging different emotions. Experiment 1 measured eye movements while participants discriminated between emotional (joy, anger, fear, sadness, shame, and disgust) and neutral facial expressions. Participant eye movements primarily fell in five distinct regions (eyes, upper nose, lower nose, upper lip, nasion). Distinct fixation patterns emerged for each emotion, such as a focus on the lips for joyful faces and a focus on the eyes for sad faces. These patterns were strongest for emotional faces but were still present when viewers sought evidence of emotion within neutral faces, indicating a goal-driven influence on eye-gaze patterns. Experiment 2 verified that these fixation patterns tended to reflect attention to the most diagnostic regions of the face for each emotion. Eye movements appear to follow both stimulus-driven and goal-driven perceptual strategies when decoding emotional information from a face.

Effect of occlusal rehabilitation on spatial memory and hippocampal neurons after long-term loss of molars in rats

Experimental loss of occlusal support caused by the extraction or grinding of molar teeth has been reported to foment the impairment of learning and memory in laboratory animals. The purpose of this study was to examine the effect of occlusal reconstruction after long-term loss of molars on spatial memory by using 8-arm radial maze and by assessing histopathological changes of neuron density in the hippocampus. Experimental dentures were inserted into the oral cavities of molarless rats to recover the occlusal support. Age-matched groups of control, molarless and denture-wearing rats were trained to perform the maze tasks. The difference of the error incidence in the maze task was evaluated between three groups. The difference of neuron density between three groups was also evaluated at the end of the maze task. Serum corticosterone levels were also measured to estimate the chronic stress, which could be caused by extraction, insertion of the experimental denture or any experimental procedure. The error incidence in the denture-wearing group was significantly higher than that of the control group, but significantly lower than that of the molarless group. Significant differences of neuron density were observed between three groups in each of the hippocampal CA1, CA3 and DG subfields. No significant difference of the serum corticosterone levels between three groups could be observed. From the results of this study, it was suggested that the recovery of occlusal support would bring amelioration of cognitive impairment concomitant with long period loss of molars in rats.

Endogenous memory CD8 T cells directly mediate cardiac allograft rejection

Differences in levels of environmentally induced memory T cells that cross-react with donor MHC molecules are postulated to account for the efficacy of allograft tolerance-inducing strategies in rodents versus their failure in nonhuman primates and human transplant patients. Strategies to study the impact of donor-reactive memory T cells on allografts in rodents have relied on the pretransplant induction of memory T cells cross-reactive with donor allogeneic MHC molecules through recipient viral infection, priming directly with donor antigen or adoptive transfer of donor antigen primed memory T cells. Each approach accelerates allograft rejection and confers resistance to tolerance induction, but also biases the T cell repertoire to strong donor reactivity. The ability of endogenous memory T cells within unprimed mice to directly reject an allograft is unknown. Here, we show a direct association between increased duration of cold ischemic allograft storage and numbers and enhanced functions of early graft infiltrating endogenous CD8 memory T cells. These T cells directly mediate rejection of allografts subjected to prolonged ischemia and this rejection is resistant to costimulatory blockade. These findings recapitulate the clinically significant impact of endogenous memory T cells with donor reactivity in a mouse transplant model in the absence of prior recipient priming.

[Immunohistochemical evaluation of somatostatin receptor subtypes in surgical pathology specimens of neuroendocrine tumors]

The clinical development of specific/selective or more potent analogues of somatostatin has made the evaluation of somatostatin receptor subtypes in archival specimens or 10% formalin-fixed and paraffin-embedded specimens of neuroendocrine tumor (NET) critical to conferring the maximum clinical benefits on NET patients. Immunohistochemistry of somatostatin receptor subtypes could contribute to profiling their expression patterns in these patients. Therefore, surgical pathologists are expected to be asked to immunostain and evaluate somatostatin receptor subtypes in NET specimens in the near future by clinicians. However, there are problems associated with immunohistochemistry of somatostatin receptor subtypes, in particular with their evaluation and interpretation. Therefore, both pathologists and clinicians involved in the care or management of NET patients should be aware of the advantages and limitations of immunohistochemical evaluation of somatostatin receptor subtypes in order to achieve the most efficient treatment outcome for patients.

Spontaneous repair of asymptomatic osteonecrosis associated with corticosteroid therapy in systemic lupus erythematosus: 10-year minimum follow-up with MRI

Systemic lupus erythematosus (SLE) patients are at high risk of developing osteonecrosis. This study utilized MRI to document the long-term natural history of asymptomatic osteonecrosis associated with corticosteroid therapy in SLE patients. Two hundred and one SLE patients treated with high-dose corticosteroids were prospectively observed from 1986 to 1997. The inclusion criterion was that patients had received periodic MRI examinations of all their hip and knee joints for ≥10 years. Joints that were already collapsed and symptomatic at the first examination were excluded. Five hundred and thirty-seven joints (251 hips and 286 knees) were identified in 144 patients, with a mean follow-up period of 13.6 years (range, 10—20 years) and a follow-up rate of 73%. Mean age of SLE onset was 26 years, and the mean highest oral corticosteroid dosage was 57 mg/day. Osteonecrosis developed in 238 (44%) of 537 joints. At final follow-up, 117 (49%) of these 238 joints demonstrated spontaneous repair in the necrotic area. Osteonecrosis completely disappeared in 21 joints. Enlargement of osteonecrosis was noted in 35 joints (15%) following increased steroid dosage because of SLE recurrence. Finally, 52 joints (22%) were collapsed. Spontaneous repair of asymptomatic osteonecrosis was observed, whereas enlargement occurred only after corticosteroid dosage increases. Lupus (2010) 19, 1307—1314.

Site-specific DNA inversion is enhanced by a DNA sequence element in cis

A segment of the bacteriophage P1 genome, called the C segment, can be inverted by site-specific recombination; the two different orientations of the invertible segment confer different host ranges to the phage. Inversion is catalyzed by the product of the cin gene which is adjacent to one of the crossover sites flanking the C segment. The Cin-catalyzed recombination can be measured in trans by using tester plasmids in which inversion switches on antibiotic-resistance genes. We show here that an additional sequence, distinct from the two crossover sites, is needed in cis for efficient inversion. This sequence is part of the cin structural gene and stimulates recombination more than 100-fold. We have localized the major enhancer sequence on a 72-base-pair fragment and found its activity to be largely independent of the orientation or position of the sequence with respect to the crossover sites.

Bortezomib-resistant myeloma cell lines: a role for mutated PSMB5 in preventing the accumulation of unfolded proteins and fatal ER stress

Bortezomib is an effective agent for treating multiple myeloma (MM). To investigate the underlying mechanisms associated with acquired resistance to this agent, we established two bortezomib-resistant MM cell lines, KMS-11/BTZ and OPM-2/BTZ, the 50% inhibitory concentration values of which were respectively 24.7- and 16.6-fold higher than their parental cell lines. No activation of caspase and BH3-only proteins such as Noxa was noted in bortezomib-resistant cells after exposure to the drug. The accumulation of polyubiquitinated proteins was reduced in bortezomib-resistant cells compared with the parental cells, associated with avoidance of catastrophic ER stress as assessed by downregulation of CHOP expression. These resistant MM cells have a unique point mutation, G322A, in the gene encoding the proteasome beta5 subunit (PSMB5), likely resulting in conformational changes to the bortezomib-binding pocket of this subunit. KMS-11 parental cells transfected to express mutated PSMB5 also showed reduced bortezomib-induced apoptosis compared with those expressing wild-type PSMB5 or the parental cells. Expression of mutated PSMB5 was associated with the prevention of the accumulation of unfolded proteins. Thus, a fraction of MM cells may acquire bortezomib resistance by suppressing apoptotic signals through the inhibition of unfolded protein accumulation and subsequent excessive ER stress by a mutation of the PSMB5 gene.

Regulation of Trigeminal Respiratory Motor Activity in the Brainstem

The trigeminal motor system participates in the control of respiration as well as suckling and mastication. However, the central mechanism underlying respiratory activity in trigeminal motoneurons is not well-understood. In this study, we aimed to elucidate brainstem circuitry for rhythm generation and signal transmission of trigeminal respiratory activity in in vitro neonatal rat brainstem-spinal cord preparations. We further examined the role of midline-crossing trigeminal interneurons in the bilateral synchronization of respiratory and suckling activity in trigeminal motor nerves. The results of brainstem-sectioning experiments indicated that respiratory rhythms were generated in the medulla and ipsilaterally transmitted to trigeminal motoneurons in the pons. We conclude that the trigeminal motor system, as well as the hypoglossal and phrenic motor system, is regulated by medullary respiratory networks, and that pontine interactions between bilateral trigeminal interneurons are not critical for the generation or synchronization of trigeminal respiratory activity, but are crucial for trigeminal suckling activity.

Development of PCR markers to detect the glb1 and Lgc1 mutations for the production of low easy-to-digest protein rice varieties

Limiting the ingestion of protein is the fundamental idea in the diet therapy for patients with chronic renal failure. Two mutations involved in the content of major rice storage proteins useful for developing low easy-to-digest protein rice variety have been isolated. The glb1 mutation causes the deficiency of alpha-globulin, and the Lgc1 mutation reduces the glutelin content. By combining the glb1 and the Lgc1 mutations, it is possible to reduce the easy-to-digest protein content by approximately 50%. The Lgc1 mutation has been shown to be caused by a 3.5-kb deletion between the glutelin structural genes, GluB4 and GluB5, while the molecular basis of glb1 mutation has been less understood. PCR analysis of the glb1 mutation revealed a 62.8-kb deletion, including the structural gene of alpha-globulin. Based on these lines of information, we generated PCR markers that make it possible to detect the glb1 and Lgc1 mutations. Using those PCR markers, we genotyped F(2) plants segregating for the glb1 mutation and the Lgc1 mutation and confirmed the consistency of genotype and phenotype. Because the PCR marker sets can distinguish heterozygotes, they will be very useful in developing new varieties of low easy-to-digest protein rice.

All-trans-retinoic acid inhibits tumour growth of malignant pleural mesothelioma in mice

Malignant pleural mesothelioma (MPM) is an aggressive malignant tumour of mesothelial origin associated with asbestos exposure. Because MPM has limited response to conventional chemotherapy and radiotherapy, the prognosis is very poor. Several researchers have reported that cytokines such as interleukin (IL)-6 play an important role in the growth of MPM. Previously, it was reported that all-trans-retinoic acid (ATRA) inhibited the production and function of IL-6 and transforming growth factor (TGF)-beta1 in experiments using lung fibroblasts. We investigated whether ATRA had an inhibitory effect on the cell growth of MPM, the origin of which was mesenchymal cells similar to lung fibroblasts, using a subcutaneous xenograft mouse model. We estimated the tumour growth and performed quantitative measurements of IL-6, TGF-beta1 and platelet-derived growth factor (PDGF) receptor (PDGFR)-beta mRNA levels both of cultured MPM cells and cells grown in mice with or without the administration of ATRA. ATRA significantly inhibited MPM tumour growth. In vitro studies disclosed that the administration of ATRA reduced 1) mRNA levels of TGF-beta1, TGF-beta1 receptors and PDGFR-beta, and 2) TGF-beta1-dependent proliferation and PDGF-BB-dependent migration of MPM cells. These data may provide a rationale to explore the clinical use of ATRA for the treatment of MPM.

Acute antibody-mediated rejection in living ABO-incompatible kidney transplantation: long-term impact and risk factors

The impact of acute antibody-mediated rejection (AAMR) on the long-term outcome on ABO-incompatible (ABOI) kidney transplantation is not well understood. We retrospectively analyzed the long-term impact of AAMR and risk factors for AAMR in 57 consecutive recipients performed between 1999 and 2004. Nineteen patients (33%) who developed AAMR within 3 months posttransplantation constituted of the AMR group. The graft survival rate was significantly lower in the AMR group (AMR vs. non-AMR, respectively; 5 years: 84% vs. 95%; 8 years: 45% vs. 95%; p = 0.009). The prevalence of transplant glomerulopathy at 1 year posttransplantation was significantly higher in the AMR group (AMR 64% vs. non-AMR 3%, p < 0.001). Multivariate analysis demonstrated that anti-blood group IgG antibody titers of 1:32 at the time of transplantation (OR, 9.52; p = 0.041) and donor-specific anti-HLA antibodies (DSHA) detected by Luminex single bead method (OR, 5.68; p = 0.015) were independent risk factors for AAMR regardless of baseline anti-blood group IgG antibody titers. Our results indicate that AAMR has a heavy impact on the long-term outcome and preoperative DSHA appears to have a more significant association with poor graft outcomes than anti-blood group antibodies, even in ABOI kidney transplantation.