Advanced functional polymers for regenerative and therapeutic dentistry

Use of ceramics and polymers continues to dominate clinical procedures in modern dentistry. Polymers have provided the basis for adhesives, tissue void fillers, and artificial replacements for whole teeth. They have been remarkably effective in the clinic at restoration of major dental functions after damage or loss of teeth. With the rapid development of polymer science, dental materials science has significantly lagged behind in harnessing these advanced polymer products. What they offer is new and unique properties superior to traditional polymers and crucially a range of properties that more closely match natural biomaterials. Therefore, we should pursue more vigorously the benefits of advanced polymers in dentistry. In this review, we highlight how the latest generation of advanced polymers will enhance the application of materials in the dental clinic using numerous promising examples. Polymers have a broad range of applications in modern dentistry. Some major applications are to construct frameworks that mimic the precise structure of tissues, to restore tooth organ function, and to deliver bioactive agents to influence cell behavior from the inside. The future of polymers in dentistry must include all these new enhancements to increase biological and clinical effectiveness beyond what can be achieved with traditional biomaterials.

Identification of oscillatory firing neurons associated with locomotion in the earthworm through synapse imaging

We used FM imaging to identify neurons that receive sensory feedback from the body wall in a circuit for octopamine (OA)-evoked rhythmic locomotion in the earthworm, Eisenia fetida. We visualized synapses in which postsynaptic neurons receive the sensory feedback, by using FM1-43 dye to label the synapses of both motor and sensory pathways that are associated with locomotion, then clearing the motor pathway synapse labeling, and finally identifying the target synapses by distinguishing physiologically functional synapses through destaining using a high-K(+) solution. A pair of synaptic regions associated with the sensory feedback was found to be located two or three cell body-widths away from the midline, between the anterior parts of the roots of the second lateral nerves (LNs) at the segmental ganglia (SGs). Using conventional intracellular recording and dye loading of the cell bodies surrounding these synaptic regions, we identified a pair of bilateral neurons with cell bodies larger than those of other cells in these regions, and named them "Oscillatory firing neurons Projecting to Peripheral nerves" (OPPs). These had a bipolar shape and projected neurites to the ipsilateral first and third LNs, fired rhythmically, and had a burst timing synchronized with the motor pattern bursts from the ipsilateral first LNs. Current injection into an OPP caused firing in the ipsilateral first LNs, supporting the hypothesis that OPPs functionally project to the peripheral nerves. OPPs also sent neurites to the adjacent anterior and posterior SGs, suggesting connections with the adjacent segments. We conclude that FM imaging can be used to identify neurons involved in specific functions, and that OPPs are the first neurons to be associated with OA-induced locomotion in the earthworm.

Arthroscopic debridement in the treatment of patients with osteoarthritis of the elbow, based on computer simulation

We retrospectively assessed the value of identifying impinging osteophytes using dynamic computer simulation of CT scans of the elbow in assisting their arthroscopic removal in patients with osteoarthritis of the elbow. A total of 20 patients were treated (19 men and one woman, mean age 38 years (19 to 55)) and followed for a mean of 25 months (24 to 29). We located the impinging osteophytes dynamically using computerised three-dimensional models of the elbow based on CT data in three positions of flexion of the elbow. These were then removed arthroscopically and a capsular release was performed.

The mean loss of extension improved from 23° (10° to 45°) pre-operatively to 9° (0° to 25°) post-operatively, and the mean flexion improved from 121° (80° to 140°) pre-operatively to 130° (110° to 145°) post-operatively. The mean Mayo Elbow Performance Score improved from 62 (30 to 85) to 95 (70 to 100) post-operatively. All patients had pain in the elbow pre-operatively which disappeared or decreased post-operatively. According to their Mayo scores, 14 patients had an excellent clinical outcome and six a good outcome; 15 were very satisfied and five were satisfied with their post-operative outcome.

We recommend this technique in the surgical management of patients with osteoarthritis of the elbow.

Cite this article: Bone Joint J 2014;96-B:237–41.

A case report on a patient who presented with myelofibrosis, developed breast cancer with myeloid metaplasia, and finally showed immature NK-cell leukemia or AML without maturation with CD56 expression transformation in the pleura with extramedullary hematopoiesis: a 25-year course

This study reports a female patient who suffered from primary myelofibrosis at 38 years of age, breast cancer with myeloid metaplasia at 49 years of age, and pleural effusion and multiple subcutaneous nodules at 62 years of age. She was finally diagnosed with immature NK-cell leukemia or AML without maturation with CD56 expression transformation of extramedullary hematopoiesis that developed in the pleura, and died 11 months later. Atypical cells in the pleural effusion had surface markers of CD13, CD33, CD34, and CD56 using a fluorescence-activated cell sorter analysis, and were positive for myeloperoxidase, CD34, CD43, and CD56 in a cell block material using an immunohistochemical method. Megakaryocytic and erythroblastic cells were also seen in the pleural effusion.

Intramural bronchogenic cyst of the oesophagus

Bronchogenic cysts are relatively common mediastinal cysts. Here, we report removal of a rare paraoesophageal-type bronchogenic cyst by video-assisted thoracoscopic surgery in a 52-year-old male patient. The defect of the oesophageal wall was successfully reinforced with an intercostal muscle flap.

Ca(2)Y(2)Cu(5)O(10): the first frustrated quasi-1D ferromagnet close to criticality

Ca(2)Y(2)Cu(5)O(10) is built up from edge-shared CuO(4) plaquettes forming spin chains. From inelastic neutron scattering data we extract an in-chain nearest-neighbor exchange J(1)≈-170  K and the frustrating next-neighbor J(2)≈32  K interactions, both significantly larger than previous estimates. The ratio α=|J(2)/J(1)|=0.19±0.01 places the system close to the critical point α(c)=0.25 of the J(1)-J(2) chain but in the 1D ferromagnetic regime. We establish that the vicinity to criticality only marginally affects the dispersion and coherence of the spin-wave-like magnetic excitations but instead results in a dramatic T dependence of high-energy Zhang-Rice singlet excitation intensities.

Carbohydrate response element-binding protein (ChREBP) plays a pivotal role in beta cell glucotoxicity

AIMS/HYPOTHESIS

This study was aimed at the elucidation of the pathogenesis of glucotoxicity, i.e. the mechanism whereby hyperglycaemia damages pancreatic beta cells. The identification of pathways in the process may help identify targets for beta cell-protective therapy. Carbohydrate response element-binding protein (ChREBP), a transcription factor that regulates the expression of multiple hyperglycaemia-induced genes, is produced in abundance in pancreatic beta cells. We hypothesise that ChREBP plays a pivotal role in mediating beta cell glucotoxicity.

METHODS

We assessed the role of ChREBP in glucotoxicity in 832/13 beta cells, isolated mouse islets and human pancreas tissue sections using multiple complementary approaches under control and high-glucose-challenge conditions as well as in adeno-associated virus-induced beta cell-specific overexpression of Chrebp (also known as Mlxipl) in mice.

RESULTS

Under both in vitro and in vivo conditions, ChREBP activates downstream target genes, including fatty acid synthase and thioredoxin-interacting protein, leading to lipid accumulation, increased oxidative stress, reduced insulin gene transcription/secretion and enhanced caspase activity and apoptosis, processes that collectively define glucotoxicity. Immunoreactive ChREBP is enriched in the nucleuses of beta cells in pancreatic tissue sections from diabetic individuals compared with non-diabetic individuals. Finally, we demonstrate that induced beta cell-specific Chrebp overexpression is sufficient to phenocopy the glucotoxicity manifestations of hyperglycaemia in mice in vivo.

CONCLUSIONS/INTERPRETATION

These data indicate that ChREBP is a key transcription factor that mediates many of the hyperglycaemia-induced activations in a gene expression programme that underlies beta cell glucotoxicity at the molecular, cellular and whole animal levels.

Epstein-Barr virus-associated lymphoproliferative disorder presenting with classical Hodgkin lymphoma and developing as peripheral T-cell lymphoma 9 years later: a case report of composite lymphoma

We describe a patient who was diagnosed with classical Hodgkin lymphoma (CHL) at 67-years-old and peripheral T-cell lymphoma, not otherwise specified (PTCL) at 76-years-old, and died 5 months later. Both tumors showed prominent epithelioid cell reaction admixed with neoplastic cells. Hodgkin and Reed-Sternberg cells in the swollen lymph node were positive for CD30 and EBV-encoded RNA (EBER). PTCL cells in the skin tumor were positive for cytoplasmic CD3ε, CD4 and EBER. A rearrangement band of the T-cell receptor gene was detected in the skin tumor. This case is the first documented EBV-associated composite lymphoma composed of CHL and PTCL. The patient may show the possibility that both EBV infection and/or immunodeficiency induce the development of CHL and PTCL.

G-CSF-producing malignant pleural mesothelioma: an autopsy case report with literature review

This study reports a 54-year-old man who was a carpenter by occupation. He suffered from left chest and back pain and left pleural effusion. Peripheral blood showed granulocytosis and high serum titers of granulocyte-colony stimulating factor (G-CSF) and CYFRA. He died 20 months later. At autopsy, a pleural tumor located around the left lung and thickening of the pericardium, diaphragm, and esophagus by tumor infiltration was seen. The tumor proliferated in papillary and solid alveolar patterns by neoplastic cells. They were positive for calretinin, D2-40, CK5/6, HBME-1, G-CSF, CK19, and E-cadherin. He was diagnosed with G-CSF-producing epithelioid malignant pleural mesothelioma.

Concurrent Gastric MALT and Hodgkin Lymphoma

This report describes a 60-year-old man with concurrent gastric extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) and classical Hodgkin lymphoma (CHL). Atypical, medium-sized, lymphoid cells proliferated in the mucosa to muscular layer of the stomach showing a lymphoepithelial lesion; admixed with Hodgkin/Reed-Sternberg (HRS) cells and an inflammatory cell background. MALT lymphoma cells expressed CD20, CD79a, PAX5, and BOB.1, and HRS cells expressed CD30, CD15, Epstein–Barr virus–encoded RNA, and EBV-latent membrane protein 1. Only CHL invaded into the regional lymph nodes. Two possibilities of transformation of MALT lymphoma into CHL and de novo CHL within MALT lymphoma are discussed.

Bence-Jones protein-type myeloma with amyloid myopathy presenting as amyloidomas and extensive amyloid deposits in the muscularis propria: a rapidly fatal autopsy case

This study reports a 59-year-old man who suffered from multiple skeletal muscle amyloidomas and showed a rapidly fatal course. He noticed left inguinal pain and gait disturbance due to muscle weakness of the left leg. Protein in urine (3.3 g/d) and Bence-Jones protein of the κ type (2.3 g/d) were detected. Bone marrow aspiration showed 11.6% monoclonal plasma cells in nucleated cells. A core needle-biopsied and resected left inguinal tumor showed the deposition of eosinophilic amorphous materials positive for Congo red stain and the κ-light chain. He was diagnosed with plasma cell myeloma with AL (amyloid light chain) amyloidosis. Multiple soft-part tumors developed, grew rapidly, and he died 3 months after admission. At autopsy, 3 large amyloidomas were observed in the skeletal muscles, and prominent amyloid deposits were also seen in the diaphragm, intercostal muscle, iliopsoas muscle, and cervical skeletal muscles examined. Massive amyloid materials deposited diffusely in the propria muscularis of the gastrointestinal tract: the tongue to the rectum.

Low-energy (<10 meV) feature in the nodal electron self-energy and strong temperature dependence of the Fermi velocity in Bi{2}Sr{2}CaCu{2}O{8+δ}

Using low photon energy angle-resolved photoemission, we study the low-energy dispersion along the nodal (π,π) direction in Bi{2}Sr{2}CaCu{2}O{8+δ} as a function of temperature. Less than 10 meV below the Fermi energy, the high-resolution data reveal a novel "kinklike" feature in the electron self-energy that is distinct from the larger well-known kink roughly 70 meV below E{F}. This new kink is strongest below the superconducting critical temperature and weakens substantially at higher temperatures. A corollary of this finding is that the Fermi velocity v{F}, as measured in this low-energy range, varies rapidly with temperature-increasing by almost 30% from 70 to 110 K. The behavior of v{F}(T) appears to shift as a function of doping, suggesting a departure from simple "universality" in the nodal Fermi velocity of cuprates.

Extensive endothelial replacement by tumor cells in the portal system: an autopsy case of intrahepatic cholangiocarcinoma

An autopsy case of intrahepatic cholangiocarcinoma (ICC) with a peculiar form of extensive portal invasion is reported here. A 76-year-old woman presented with anorexia and abdominal discomfort. A high level of serum carbohydrate antigen 19-9 and endoscopically detected esophageal varices were found. Obvious mass lesion was not identified on CT scan and no portal blood flow was found. The patient died 6 months after admission. At autopsy multiple irregular shaped tumors in the liver were found. The size of the largest one was 3 x 2 cm. These tumors were well-differentiated adenocarcinomas with partial mucinous carcinoma morphology. Surprisingly, portal veins contained mucinous fluid and the inner surface was lined with a single layer of tumor cells but not endothelial cells. Invasion of carcinoma into the tissue outside the blood vessels was hardly observed in organs other than the liver. This form of extensive invasion of the tumor, termed intimal carcinoma spreading, caused complete obstruction of the portal system. To our knowledge there has been no report on this type of portal invasion of ICC.