Plasma Gel Matrix as a Promising Carrier of Epigallocatechin Gallate for Regenerative Medicine

Plasma gel (PG) is a protein matrix prepared from platelet-poor plasma and can be utilized as a drug carrier for controlled release. We previously demonstrated its applicability as a carrier of polyphosphate. Epigallocatechin-3-gallate (EGCG) is the main flavonoid found in green tea and functions as a strong antioxidant. To explore the applicability of PG as an EGCG carrier, we examined the release of EGCG from the PG matrix using an in vitro system. Pooled platelet-poor plasma (PPP) was prepared from four healthy adult male donors, mixed with EGCG, and heated at 75 °C for 10 or 20 min to prepare the PG matrix. The PG-EGCG matrix was incubated in PBS at 37 °C, and the EGCG released into PBS was determined using spectrophotometry. The antioxidant capacity was determined based on the principle of the iodine decolorization reaction. EGCG precipitated and incorporated into the PG matrix during thermal preparation. Trypsin, used to simulate the in vivo degradation of PG, released EGCG from the PG matrix over time. The released EGCG maintained its antioxidant capacity during incubation. These results indicate that thermally prepared PG matrices can be utilized as a promising EGCG carrier in the fields of tissue engineering and regenerative medicine.

Plasma Gel Made of Platelet-Poor Plasma: In Vitro Verification as a Carrier of Polyphosphate

Plasma gel (PG) is a blood-derived biomaterial that can be prepared by heating or chemical cross-linking without the aid of intrinsic coagulation activity and has gradually been applied in the field of esthetic surgery. To explore the applicability of PG in regenerative therapy or tissue engineering, in this study, we focused on the advantages of the heating method and verified the retention capacity of the resulting PG for polyphosphate (polyP), a polyanion that contributes to hemostasis and bone regeneration. Pooled platelet-poor plasma (PPP) was prepared from four healthy male adult donors, mixed with synthetic polyP, and heated at 75 °C for 10 or 30 min to prepare PG in microtubes. The PG was incubated in PBS at 37 °C, and polyP levels in the extra-matrix PBS were determined by the fluorometric method every 24 h. The microstructure of PG was examined using scanning electron microscopy. In the small PG matrices, almost all of the added polyP (~100%) was released within the initial 24 h. In contrast, in the large PG matrices, approximately 50% of the polyP was released within the initial 24 h and thereafter gradually released over time. Owing to its simple chemical structure, linear polyP cannot be theoretically retained in the gel matrices used in this study. However, these findings suggest that thermally prepared PG matrices can be applied as carriers of polyP in tissue engineering and regenerative medicine.

Responses of promyelocytic leukemia HL60 cells as an inflammatory cell lineage model to silica microparticles used to coat blood collection tubes

Background

The preparation of platelet-rich fibrin (PRF) requires glass blood collection tubes, and thus, the shortage or unavailability of such tubes has driven clinicians to search for suitable substitutes, such as silica-coated plastic tubes. However, we have previously demonstrated the cytotoxicity of silica microparticles (MPs) used in plastic tubes to cultured human periosteal cells. To further establish the effects of silica MPs on inflammation, we examined silica MP-induced changes in a human promyelocytic cell model in vitro.

Methods

Human promyelocytic HL60 cells were used either without chemical induction or after differentiation induced using phorbol myristate acetate (PMA) or dimethyl sulfoxide. HL60 cells, osteoblastic MG63, and Balb/c mouse cells were treated with silica MPs, and their surface ultrastructure and numbers were examined using a scanning electron microscope and an automated cell counter, respectively. Differentiation markers, such as acid phosphatase, non-specific esterase, and CD11b, were visualized by cytochemical and immunofluorescent staining, and superoxide dismutase (SOD) activity was quantified.

Results

Regardless of SOD activity, silica cytotoxicity was observed in MG63 and Balb/c cells. At sub-toxic doses, silica MPs slightly or moderately upregulated the differentiation markers of the control, PMA-induced monocytic, and dimethyl sulfoxide-induced granulocytic HL60 cells. Although SOD activity was the highest (P < 0.05) in PMA-induced cells, a silica-induced reduction in cell adhesion was observed only in those cells (P < 0.05).

Conclusions

Silica MP contamination of PRF preparations can potentially exacerbate inflammation at implantation sites. Consequently, unless biomedical advantages can be identified, silica-coated plastic blood collection tubes should not be routinely used for PRF preparations.

Non-destructive, spectrophotometric analysis of the thickness of the cell-multilayered periosteal sheet

Background

Autologous tissue-engineered periosteal sheets, which have been clinically applied for periodontal regeneration, sinus lift, and alveolar ridge augmentation, are enriched with osteoblast precursor cells and the abundant deposition of collagen type I in the extracellular spaces. Their quality is inspected prior to clinical use; however, most criteria cannot be evaluated without sacrificing samples. To reduce such losses, we developed a non-destructive optical method that can quantitatively evaluate the thickness of the periosteal sheet.

Methods

Dispersed periosteal cells were inoculated into small pieces of collagen sponge (Terudermis®) and plated into 60-mm dishes for further explant culture using a conventional medium and a stem-cell culture medium. The thickness of periosteal sheets was evaluated using inverted microscopic, histological, labeling (CellVue®)-based imaging and spectrophotometric (Spectro-1®) methods.

Results

The three-dimensional growth of periosteal sheets did not necessarily correlate with two-dimensional growth. The periosteal sheet prepared with the stem-cell medium formed cell multilayers, a phenomenon that could be observed qualitatively by inverted microscopy. The spectrophotometric analysis enabled the quantitative evaluation of the thickness of the cell multilayer without sacrificing the samples processed for scheduled cell therapy.

Conclusions

The growth of periosteal sheets is influenced by several major factors, including the basic quality of the individual original periosteal tissue segments, the technical expertise of doctors and operators involved in tissue harvesting and processing, and culture conditions. This newly developed spectrophotometric analysis can quantify the thickness of cell-multilayered periosteal sheets for quality assurance in a non-destructive manner, thereby contributing to better bone augmentation prior to implant therapy.

Effects of SARS‑CoV‑2 mRNA vaccines on platelet polyphosphate levels and inflammation: A pilot study

Platelets function as immune cells in conjunction with white blood cells, targeting invading pathogens and inducing immune reactions. Intercellular communications among these immune cells are partly mediated by platelet polyphosphate (polyP), which was originally recognized as a thrombotic and hemostatic biomolecule. To determine the involvement of polyP in SARS-CoV-2-mRNA vaccine-induced immune responses, specifically in inflammatory responses, the effects of mRNA vaccines on platelet polyP levels were examined. Before and after vaccination with the COVID-19 vaccine (BNT162b2), blood samples were obtained from healthy, non-smoking individuals who did not have any systemic diseases. Test group demographics skewed somewhat towards either older males (first vaccination, n=6; second vaccination, n=8) or younger females (first vaccination, n=14; second vaccination, n=23). polyP levels in washed platelets from the blood samples were determined using the fluorometric method with DAPI. The side-effects of vaccination were recorded as scores. In the female group, platelet polyP levels decreased after the first vaccination, and the side-effect score increased after the second vaccination. Moderate correlation coefficients were observed between the reduction in polyP levels and the side-effect scores and pre-vaccination polyP levels. Despite the small sample size, this pilot study suggests that platelet polyP may suppress the side effects induced by the mRNA vaccines after the first vaccination, but not the second vaccination in younger female subjects, who generally have higher immune responsiveness than their male counterparts.

Fluorescent Cytochemical Detection of Polyphosphates Associated with Human Platelets

Polyphosphate (polyP) is released from activated platelets and activates the intrinsic coagulation pathway. However, polyP may also be involved in various pathophysiological functions related to platelets. To clarify these functions, we established a cytochemical method to reproducibly visualize polyP in platelets. Platelets obtained from healthy non-smoking donors were suspended in phosphate-buffered saline and quickly immobilized on glass slides using a Cytospin. After fixation and membrane permeabilization, platelets were treated with 4′,6- diamidino-2-phenylindole (DAPI) and examined using a fluorescence microscope with a blue-violet excitation filter block (BV-2A). Fixed platelets were also subjected to immunocytochemical examination to visualize serotonin distribution. Under the optimized conditions for polyP visualization, immobilized platelets were fixed with 10% neutral-buffered formalin for 4 h or longer and treated with DAPI at a concentration of 10 µg/mL in 0.02% saponin- or 0.1% Tween-20-containing Hanks balanced salt solution as a permeabilization buffer for 30 min at room temperature (22–25 °C). Based on the results obtained by using activated platelets, treatment with alkaline phosphatases, and serotonin release, the DAPI⁺ targets were identified as polyP. Therefore, this cytochemical method is useful for determining the amount and distribution of polyP in platelets.

Distribution and quantification of activated platelets in platelet-rich fibrin matrices

Platelet-rich fibrin (PRF) has been widely applied in regenerative therapy owing to its simple preparation protocol. To date, the original protocol for preparing leukocyte-rich (L)-PRF has been modified to produce derivatives such as advanced (A)-PRF, concentrated growth factors (CGF), and horizontal (H)-PRF. However, these derivatives have not been rigorously compared to explore possible differences. We previously developed and validated a nondestructive near-infrared (NIR) imaging method to quantitatively examine the platelet distribution in PRF matrices. To further evaluate the characteristics of platelets in PRF, we herein examined the distribution of activated platelets. Four types of PRF matrices were prepared under different centrifugal conditions from blood samples obtained from the same healthy donors. After fixation and compression, the matrices were stained immunohistochemically without sectioning and visualized using an NIR imager. Qualitative morphological analysis revealed that whole platelets were distributed widely and homogeneously in H-PRF and A-PRF, but localized along the distal tube surface in L-PRF and CGF. Activated platelets were distributed as were whole platelets in A-PRF, L-PRF, and CGF, but localized mainly in the "buffy coat" region in H-PRF. Quantitative analysis revealed that there was no significant difference in the ratio of activated to whole platelets between PRF derivatives. These findings suggest that platelet activation is similarly induced in fibrin matrices regardless of centrifugal speed or rotor angulation. However, only the H-PRF group was distinguishable from the other PRF derivatives in terms of activated platelet distribution.

Quantitative Near-Infrared Imaging of Platelets in Platelet-Rich Fibrin (PRF) Matrices: Comparative Analysis of Bio-PRF, Leukocyte-Rich PRF, Advanced-PRF and Concentrated Growth Factors

Platelet-rich fibrin (PRF) is a fibrin matrix enriched with platelets. The PRF matrix is thought to form a steep gradient of platelet density around the region corresponding to the buffy coat in anticoagulated blood samples. However, this phenomenon has not yet been proven. To visualize platelet distribution in PRF in a non-invasive manner, we utilized near-infrared (NIR) imaging technology. In this study, four types of PRF matrices, bio-PRF, advanced-PRF (A-PRF), leukocyte-rich PRF (L-PRF), and concentrated growth factors (CGF) were compared. Blood samples collected from healthy, non-smoking volunteers were immediately centrifuged using four different protocols in glass tubes. The fixed PRF matrices were sagittally divided into two equal parts, and subjected to modified immunohistochemical examination. After probing with NIR dye-conjugated secondary antibody, the CD41⁺ platelets were visualized using an NIR imager. In L-PRF and CGF, platelets were distributed mainly on and below the distal surface, while in bio-PRF and A-PRF, platelet distribution was widespread and homogenous. Among three regions of the PRF matrices (upper, middle, and lower), no significant differences were observed. These findings suggest that platelets aggregate on polymerizing fibrin fibers and float up as a PRF matrix into the plasma fraction, amending the current “gradient” theory of platelet distribution.

Concentrated Growth Factor Matrices Prepared Using Silica-Coated Plastic Tubes Are Distinguishable From Those Prepared Using Glass Tubes in Platelet Distribution: Application of a Novel Near-Infrared Imaging-Based, Quantitative Technique

Platelet-rich fibrin (PRF) matrices were originally prepared using plain glass tubes without the aid of coagulation factors because coagulation factor XII is activated by glass surfaces. Recently, the use of silica-coated plastic tubes as a substitute of glass tubes has been recommended for PRF preparation. This recommendation is owing not only to the shortage of glass tubes for medical use in the market, but also the higher coagulation activity of silica-coated plastic tubes and equal quality of PRF. However, these matrices are not the same. To evaluate the differences, we compared glass- and silica-coated plastic tubes in terms of platelet distribution and quantity in concentrated growth factors (CGF). CGF matrices were immediately prepared from freshly collected blood samples, fixed after red thrombus removal, and divided into two equal pieces sagittally. One piece was used for CD41 detection and the other was applied as an isotype control. Platelet distribution in CGF matrices was examined, without embedding or sectioning, by a novel method using invisible near-infrared imaging. The dehydrated membranous CGF matrix was more transparent. Thus, the fluorescence signal was clearly detectable with less scattering. Platelets were distributed mainly in the distal side of the glass-prepared CGF matrix, but homogeneously in the silica-prepared CGF matrix. Platelet count was positively correlated with fluorescence intensity. Although not yet fully developed, this imaging technique enabled us to recognize the differences in platelet distribution and quantity in CGF matrices by excluding bias caused by the technical limitations of scanning electron microscopy and conventional immunohistochemical methods.

A Comparative Study of The Effects of Anticoagulants on Pure Platelet-Rich Plasma Quality and Potency

It is generally accepted that citrate or the A-form of acid-citrate-dextrose (ACD-A) are suitable for preparing platelet-rich plasma (PRP) for regenerative therapy. However, this is based on evidence from blood transfusions and not from regenerative medicine. Thus, we examined the effects of anticoagulants, such as ACD-A, ethylenediaminetetraacetic acid (EDTA), and heparin, on the regenerative quality of PRP to address this gap. The blood samples were collected in the presence of anticoagulants and were processed to prepare pure-PRP. Platelet size, activation status, and intra-platelet free Ca²⁺ concentration were determined while using a hematology analyzer and flow cytometer. Platelet-derived growth factor-BB (PDGF-BB) was quantified while using an ELISA. In pure-PRP samples, EDTA caused platelet swelling and activation, but yielded the highest number of platelets. Heparin aggregated platelets and disturbed the overall counting of blood cells. However, no significant differences in PDGF-BB levels were observed among the anticoagulants tested. Moreover, when considering the easy preparation of platelet suspensions, without the need for high-level pipetting skills, these findings suggest the comparable potency of EDTA-derived pure-PRP in tissue regeneration and support the use of EDTA in the preparation of pure-PRP. Further in vivo studies are required in animal models to exclude the possible negative effects of including EDTA in pure-PRP preparations.

Spectrophotometric Determination of the Aggregation Activity of Platelets in Platelet-Rich Plasma for Better Quality Control

Although platelet-rich plasma (PRP) is now widely used in regenerative medicine and dentistry, contradictory clinical outcomes have often been obtained. To minimize such differences and to obtain high quality evidence from clinical studies, the PRP preparation protocol needs to be standardized. In addition, emphasis must be placed on quality control. Following our previous spectrophotometric method of platelet counting, in this study, another simple and convenient spectrophotometric method to determine platelet aggregation activity has been developed. Citrated blood samples were collected from healthy donors and used. After centrifugation twice, platelets were suspended in phosphate buffered saline (PBS) and adenosine diphosphate (ADP)-induced aggregation was determined using a spectrophotometer at 615 nm. For validation, platelets pretreated with aspirin, an antiplatelet agent, or hydrogen peroxide (H₂O₂), an oxidative stress-inducing agent, were also analyzed. Optimal platelet concentration, assay buffer solution, and representative time point for determination of aggregation were found to be 50–100 × 10⁴/μL, PBS, and 3 min after stimulation, respectively. Suppressed or injured platelets showed a significantly lower aggregation response to ADP. Therefore, it suggests that this spectrophotometric method may be useful in quick chair-side evaluation of individual PRP quality.

Platelet adhesion on commercially pure titanium plates in vitro I: effects of plasma components and involvement of the von Willebrand factor and fibronectin

Background

Platelet-rich plasma (PRP) is widely used in regenerative dentistry. Furthermore, it is often applied in the pretreatment of titanium implants to improve their surface bioaffinity and initial stability. However, effects of PRP application on implant surface at cellular and molecular levels remain poorly understood. Therefore, we examined platelet adhesion on commercially pure titanium (cp-Ti) plates, with a particular focus on fibrinogen (FGN), von Willebrand factor (vWF), and fibronectin (FN), in the presence or absence of plasma components.

Methods

Citrated blood samples were obtained from six healthy male volunteers, and pure-PRP (P-PRP) and pure platelet suspensions in phosphate-buffered saline (PBS) were prepared. Platelet adhesion on cp-Ti plate surface was evaluated by phalloidin staining and tetrazolium dye assay. Distribution of FGN, vWF, FN, albumin, CD62P, and CD63 was examined by immunocytochemical analysis.

Results

Platelets in PBS suspensions rapidly and time-dependently adhered to cp-Ti plate surface, but this adhesion was substantially disturbed by the presence of plasma components. FGN was most preferably adsorbed regardless of the presence or absence of plasma components, while vWF and FN showed greater accumulation on platelet adhesion area.

Conclusions

Although FGN is rapidly and abundantly adsorbed on cp-Ti plate surface, vWF and FN function as major platelet adhesion molecules in citrated blood samples. After pretreatment with P-PRP, however, platelets adhered to cp-Ti much less efficiently. Therefore, P-PRP pretreatment might not directly contribute to surface functionalization, initial stabilization, and osseointegration of machined or similar types of implants.

Electronic supplementary material

The online version of this article (10.1186/s40729-019-0160-z) contains supplementary material, which is available to authorized users.

Safety of Elderly Living Kidney Donors: 2 Cases of Donors Older Than 80 Years: A Case Report

Much controversy exists over the performance of elderly living donor kidney transplantation. We report the safety of 2 cases of elderly living kidney donations in our hospital. CASE 1: An 82-year-old man was a living kidney donor for his 56-year-old son. The donor suffered from hypertension, but has successfully managed his blood pressure with only one medication. His serum creatinine was 0.7 mg/dL and inulin clearance was 122.5 mL/min, which met the usual criteria for living kidney donors. This was his son's secondary kidney transplantation, and no other donors existed. CASE 2: An 80-year-old woman was a living kidney donor for her 45-year-old son. Her serum creatinine was 0.61 mg/dL and inulin clearance was 71.7 mL/min, which met the marginal kidney donor criteria. In both cases, we determined that the donor kidney function was acceptable. Though we explained the risks of the transplantation thoroughly, the patients' strong will to offer a kidney to their family member did not change. We decided to carry out the transplantation. At the time of publication, nearly 2 years have passed since the transplantation, but both donors and recipients are doing well. In the future, it seems more likely that the number of elderly living donor kidney transplantation will rise. On one hand, there is no absolute contraindication for elderly donors, while on the other hand, the criteria for a living kidney donor must be strictly examined. Furthermore, careful observation of both donors and recipients after transplantation is required.

Spectrophotometric determination of platelet counts in platelet-rich plasma

BACKGROUND

Platelet-rich plasma (PRP) is widely used in regenerative dentistry and other medical fields. However, its effectiveness has often been questioned. For better evaluation, the quality of individual PRP preparations should be assured prior to use. We proposed a spectrophotometric method for determination of platelet counts and validated its applicability using two types of PRP preparations.

METHODS

Blood samples were obtained from healthy male volunteers and pure PRP (P-PRP) and leukocytes-rich PRP (L-PRP) were prepared using the double-spin method. In serial dilutions, platelet counts in P-PRP and L-PRP were determined using an automated hematology analyzer and a compact spectrophotometer. For validation, P-PRP and L-PRP independently prepared by three well-trained operators were used for comparison of the calculated and measured platelet counts.

RESULTS

In the two types of PRP samples evaluated, platelet counts were almost equal and greater amount of both white blood cells (WBCs) and red blood cells (RBCs) were included in L-PRP preparations. The calibration curve obtained from serially diluted P-PRP showed a strong correlation (R2 = 0.995), whereas that of L-PRP was relatively weaker (R2 = 0.975). In validation testing, the scatter plot of the calculated platelet counts versus the measured values showed a strong correlation in P-PRP (R2 = 0.671), whereas that of L-PRP showed a much weaker correlation (R2 = 0.0605).

CONCLUSIONS

This method can precisely determine platelet counts in PRP preparations when the inclusion of WBCs or RBCs is minimized. Therefore, we recommend that clinicians use this method for quality assurance of individual PRP preparations.

Direct activation of platelets by addition of CaCl2 leads coagulation of platelet-rich plasma

Background

Based on the notion that full activation of platelets is required for a growth factor release, in regenerative dentistry, platelet-rich plasma (PRP) in liquid form is usually clotted by addition of CaCl₂ in glassware before topical implantation. However, there has been no evidence as to which is better, full or partial activation of platelets, for minimizing the loss of growth factors and improving the controlled release of growth factors from coagulated PRP. To address this matter, here, we primarily examined direct effects of CaCl₂ on platelets in PBS and on coagulation in citrated PRP.

Methods

PRP was prepared from healthy volunteers’ blood. Platelets’ actions were monitored by scanning electron microscopy, flow cytometry, digital holographic microscopy, and immunofluorescent staining. Clot formation was examined in plasma.

Results

In plasma-free PBS, 0.1% CaCl₂ immediately upregulated CD62P and CD63, causing a release of microparticles and fibrinogen/fibrin; consequently, platelets aggregated and adhered to polystyrene culture dishes with enlargement of their attachment area. In a clot formation assay in plasma, CaCl₂ initially induced platelet aggregation, which triggered loop-like matrix formation and subsequently induced coagulation on a watch glass. Such changes were not clearly observed either with PRP in a plastic dish or in platelet-poor plasma on a watch glass: coagulation was delayed in both conditions.

Conclusions

These findings indicate that besides the well-known coagulation pathway, which activates platelets via thrombin conversion in a coagulation cascade, CaCl₂ directly activates platelets, which then facilitate clot formation independently and in cooperation with the coagulation pathway.

Quantitative evaluation of morphological changes in activated platelets in vitro using digital holographic microscopy

Platelet activation and aggregation have been conventionally evaluated using an aggregometer. However, this method is suitable for short-term but not long-term quantitative evaluation of platelet aggregation, morphological changes, and/or adhesion to specific materials. The recently developed digital holographic microscopy (DHM) has enabled the quantitative evaluation of cell size and morphology without labeling or destruction. Thus, we aim to validate its applicability in quantitatively evaluating changes in cell morphology, especially in the aggregation and spreading of activated platelets, thus modifying typical image analysis procedures to suit aggregated platelets. Freshly prepared platelet-rich plasma was washed with phosphate-buffered saline and treated with 0.1% CaCl₂. Platelets were then fixed and subjected to DHM, scanning electron microscopy (SEM), atomic force microscopy, optical microscopy, and flow cytometry (FCM). Tightly aggregated platelets were identified as single cells. Data obtained from time-course experiments were plotted two-dimensionally according to the average optical thickness versus attachment area and divided into four regions. The majority of the control platelets, which supposedly contained small and round platelets, were distributed in the lower left region. As activation time increased, however, this population dispersed toward the upper right region. The distribution shift demonstrated by DHM was essentially consistent with data obtained from SEM and FCM. Therefore, DHM was validated as a promising device for testing platelet function given that it allows for the quantitative evaluation of activation-dependent morphological changes in platelets. DHM technology will be applicable to the quality assurance of platelet concentrates, as well as diagnosis and drug discovery related to platelet functions.

Determination of HLA-A, -C, -B, -DRB1 allele and haplotype frequency in Japanese population based on family study

The present study investigates the human leucocyte antigen (HLA) allele and haplotype frequencies in Japanese population. We carried out the frequency analysis in 5824 families living across Japanese archipelago. The studied population has mainly been typed for the purpose of transplant, especially the hematopoietic stem cell transplantation (HSCT). We determined HLA class I (A, B, and C) and HLA class II (DRB1) using Luminex technology. The haplotypes were directly counted by segregation. A total of 44 HLA‐A, 29 HLA‐C, 75 HLA‐B, and 42 HLA‐DRB1 alleles were identified. In the HLA haplotypes of A‐C‐B‐DRB1 and C‐B, the pattern of linkage disequilibrium peculiar to Japanese population has been confirmed. Moreover, the haplotype frequencies based on family study was compared with the frequencies estimated by maximum likelihood estimation (MLE), and the equivalent results were obtained. The allele and haplotype frequencies obtained in this study could be useful for anthropology, transplantation therapy, and disease association studies.

Prognostic nomogram for nonresectable pancreatic cancer treated with gemcitabine-based chemotherapy

Background:

A nomogram is progressively being used as a useful predictive tool for cancer prognosis. A nomogram to predict survival in nonresectable pancreatic cancer treated with chemotherapy has not been reported.

Methods:

Using prospectively collected data on patients with nonresectable pancreatic cancer receiving gemcitabine-based chemotherapy at five Japanese hospitals, we derived a predictive nomogram and internally validated it using a concordance index and calibration plots.

Results:

In total, 531 patients were included between June 2001 and February 2013. The American Joint Committee on Cancer (AJCC) TNM stages were III and IV in 204 and 327 patients, respectively. The median survival time of the total cohort was 11.3 months. A nomogram was generated to predict survival probabilities at 6, 12, and 18 months and median survival time, based on the following six variables: age; sex; performance status; tumour size; regional lymph node metastasis; and distant metastasis. The concordance index of the present nomogram was higher than that of the AJCC TNM staging system at 12 months (0.686 vs 0.612). The calibration plots demonstrated good fitness of the nomogram for survival prediction.

Conclusions:

The present nomogram can provide valuable information for tailored decision-making early after the diagnosis of nonresectable pancreatic cancer.

The role of S-1 in gemcitabine-refractory pancreatic cancer: A retrospective single-institution study

e15648

Background: S-1 was reported to be active against gemcitabine (Gem)-refractory pancreatic cancer (PaC) in Japan and was introduced in February 2005 in our institution. The aim of this study was to elucidate the impact of S-1 on prognosis of patients with Gem- refractory PaC. Methods: A total of 108 patients (pts) with advanced PaC who were treated with Gem and had disease progression (PD) at the University of Tokyo Hospital were analyzed. The introduction rates of second-line chemotherapy and the causes of introduction failure were assessed. Prognostic factors for residual survival (RS) for Gem-refractory PaC were analyzed by the Cox proportional hazard model. Results: Of 108 pts with Gem-refractory PaC, 47 pts (PreS-1 Group) had PD before February 2005, the time of S-1 introduction in our institution, and 61 pts (PostS-1 Group) after February 2005. There were no differences in baseline characteristics at PD for Gem between PreS-1 and PostS-1 Groups, except for metastasis to peritoneum more prevalent in PreS-1 Group (44.7% in PreS-1 Group and 23.0% in PostS-1 Group, p=0.023). The introduction rate of second-line chemotherapy increased from 12.8% in PreS-1 Group to 45.9% in PostS-1 Group. Second-line chemotherapy was administered in 34 pts, 29 by S-1, 4 by 5-FU-based chemoradiation, and 1 by 5-FU. The causes of introduction failure of second line chemotherapy were poor PS in 64.9%, patients’ refusal in 16.2%, infection in 2.7%, adverse effects of Gem in 1.4% and jaundice in 1.4%. RR, PFS, and OS for second-line S-1 were 17.2%, 2.5 Mo, and 7.8 Mo, respectively. PFS for Gem was not prognostic of PFS for S-1 (2.5 Mo both in pts with PFS >6Mo and in pts with PFS <6Mo for Gem). RS after PD for Gem was prolonged from 3.1 Mo in PreS-1 Group to 6.5 Mo in PostS-1 Group (p<0.001). The Cox hazard model revealed PreS-1 Group (HR2.42, p=0.001) in addition to male gender (HR1.83, p=0.019), poor PS (HR3.52, p<0.001), liver metastasis (HR2.36, p=0.037), elevated LDH (per 100U/L increase) (HR 1.30, p=0.046), elevated CRP (HR 1.14, p=0.023) at PD for Gem as poor prognostic factors of RS for Gem-refractory PaC. Conclusions: Introduction of S-1 might lead to improvement of prognosis in patients with Gem-refractory PaC.

No significant financial relationships to disclose.

Possible relationship between chronic inflammation and pyloric metaplasia in a patient with lobular endocervical glandular hyperplasia

BACKGROUND

Lobular endocervical glandular hyperplasia (LEGH) is a rare entity of a pseudoneoplastic benign condition of the uterine cervix, and its histogenesis and pathological significance including a connection with carcinogenesis of the endocervical gland has not yet been fully recognized.

CASE

We describe a rare case of localized LEGH, which developed adjacent to a cesarean section scar. A 53-year-old premenopausal woman presented with a recent onset of abdominal distention and menorrhagia. Magnetic resonance imaging revealed multiple uterine myomas including submucosal myoma and localized small cystic lesions in the proximal area of the anterior wall of the cervix. Total hysterectomy was performed. The cystic lesions were diagnosed as LEGH. Thread-like foreign bodies and inflammatory reaction were demonstrated around several hyperplastic lesions. Focal immunoreactivity for MIB-1 was detected only in the LEGH cells adjacent to the fibrosis and foreign body reaction.

DISCUSSION

The histological findings, in relation to the previous cesarean section suggest that the ectopic pyloric hyperplasia in the present case could represent a heteroplastic or metaplastic process due to a multidirectional differentiation of cervical glands during chronic inflammation by foreign bodies.

Endocervical adenocarcinoma associated with lobular endocervical glandular hyperplasia showing rapid reaccumulation of hydrometra

Mucinous endocervical adenocarcinoma is characterized by increased watery vaginal discharge, but the early diagnosis is sometimes difficult because biopsy specimen might only serve to sample a superficial part of the tumor. The patient presented with complaints of abdominal distention. No vaginal bleeding or watery discharge was observed. Hydrometra was suspected by imaging studies. Rapid reaccumulation of hydrometra was seen despite drainage. Papanicolaou smear of endocervix and endometrium followed by fractional curettage was performed, but failed to confirm the diagnosis. To investigate the unknown origin of hydrometra, an exploratory laparotomy with total hysterectomy and bilateral salpingo-oophorectomy was performed, followed by pelvic lymphadenectomy because biopsy specimens during operation suggested adenocarcinoma of the cervix. The final pathologic study of surgical specimens revealed mucinous adenocarcinoma, which was located on the proximal area of cervix. Adjacent to carcinoma tissue, lobular endocervical glandular hyperplasia (LEGH) was detected. Pyloric gland mucin (HIK1083), MUC6, and MUC5AC were diffusely immunopositive in the cytoplasm of LEGH cells and the immunoreactivity became weaker in adenocarcinoma cells with tumor progression and loss of differentiation. Based on histopathologic features of the present case, there seems to be a possible link between LEGH and conventional mucinous endocervical adenocarcinomas. The physician should keep in mind the possible existence of endocervical adenocarcinoma in a patient showing rapid reaccumulation of hydrometra, when uterine malignancies are clinically suspected and biopsy finding fails to confirm the diagnosis.

Self-expandable metallic stents for malignant biliary obstruction with an anomalous pancreaticobiliary junction

BACKGROUND

Anomalous pancreaticobiliary junction (APBJ) is associated with pancreaticobiliary cancer. Limited data are available on endoscopic biliary drainage for unresectable malignant biliary obstruction with APBJ. This study evaluated the efficacy and safety of self-expandable metallic stents (EMSs) for the management of malignant biliary obstruction with APBJ.

METHODS

Between 1993 and 2005, 324 patients with unresectable malignant biliary obstruction underwent insertion of an EMS. Six of these patients with concomitant APBJ constituted the subjects of this study. Early (</=30 days after EMS insertion) and late (>30 days after EMS insertion) stent-related complications and stent patency were evaluated in these six patients.

RESULTS

The cause of biliary obstruction was gallbladder cancer in four patients and pancreatic cancer in two patients. Uncovered EMSs were inserted across the common channel without performance of a biliary sphincterotomy. The diameter of the uncovered EMS used was based on the diameter of the common channel. For all six patients, endoscopic biliary drainage was successful, and their jaundice subsided steadily. None of the six patients experienced early complications, including acute pancreatitis. The mean stent-related complication-free period was 163 days. Stent occlusion caused by tumor ingrowth occurred in two patients. Acute cholangitis and cholecystitis were observed in one patient each.

CONCLUSIONS

Uncovered EMSs are effective for palliation of unresectable malignant biliary obstruction in patients who have APBJ without increasing the risk of stent-related early complications.

Endoscopic transpapillary approach to the gallbladder for diagnosing gallbladder cancer

PURPOSE

Gallbladder cancer (GBC) has a poor prognosis that is related to delayed diagnosis. The present study evaluated the efficacy of the transcystic ductal approach in diagnosing GBC.

METHODS

A catheter was introduced into the gallbladder endoscopically via the cystic duct to obtain bile for cytology. Subsequently, cytology specimens were collected using a brush, and intraductal ultrasonography (IDUS) was performed using a miniature probe in patients suspected of having GBC.

RESULTS

Bile cytology was performed successfully in 23 of 25 patients (92%). The sensitivity, specificity and accuracy of cytology were 44.4%, 100% and 78.3%, respectively. Brush cytology and IDUS were successful in six of eight (75%) and nine of 15 (60%) patients, respectively. Brush cytology was positive in two of five patients with GBC. In all four patients with invasive cancer, IDUS showed an irregularity or disruption of the outermost hyperechoic layer.

CONCLUSIONS

The endoscopic transpapillary approach to the gallbladder was useful for the diagnosis of GBC. Brush cytology and IDUS may improve diagnostic efficacy and provide more useful information.

Quantitative evaluation of vimentin expression in tumour stroma of colorectal cancer

Recent studies have identified vimentin, a type III intermediate filament, among genes differentially expressed in tumours with more invasive features, suggesting an association between vimentin and tumour progression. The aim of this study, was to investigate whether vimentin expression in colon cancer tissue is of clinical relevance. We performed immunostaining in 142 colorectal cancer (CRC) samples and quantified the amount of vimentin expression using computer-assisted image analysis. Vimentin expression in the tumour stroma of CRC was associated with shorter survival. Overall survival in the high vimentin expression group was 71.2% compared with 90.4% in the low-expression group (P=0.002), whereas disease-free survival for the high-expression group was 62.7% compared with 86.7% for the low-expression group (P=0.001). Furthermore, the prognostic power of vimentin for disease recurrence was maintained in both stage II and III CRC. Multivariate analysis suggested that vimentin was a better prognostic indicator for disease recurrence (risk ratio=3.5) than the widely used lymph node status (risk ratio=2.2). Vimentin expression in the tumour stroma may reflect a higher malignant potential of the tumour and may be a useful predictive marker for disease recurrence in CRC patients.

Impressive remission of locally advanced malignant peritoneal mesothelioma treated with combination of radiotherapy and intraperitoneal paclitaxel

BACKGROUND

The results of treatment of malignant peritoneal mesothelioma are quite unsatisfactory, especially in the later stages of the disease, regardless of the treatment modality employed.

CASE

We report a case of locally advanced malignant peritoneal mesothelioma, in which the combination of radiotherapy and intraperitoneal paclitaxel was beneficial for long-term disease stabilization. A 71-year-old woman presented with abdominal pain. Abdominal ultrasound and magnetic resonance imaging confirmed the presence of a mass with both cystic and solid components with moderate ascites. Serum CA-125 concentration was 727 IU/ml. At exploratory laparotomy, a large mass originating from the pouch of Douglas was found. A total abdominal hysterectomy and bilateral salpingo-oophorectomy was performed with partial excision of the mass and involved the peritoneum of the pouch of Douglas. The histologic study showed malignant peritoneal mesothelioma. One year and five months after surgery, significant progression of the residual tumor with increasing ascites was noted. Radiotherapy to the whole pelvis with 45 Gy in 25 fractions was given over five weeks together with intraperitoneal paclitaxel (60 mg/m2) instillation, which was repeated every three weeks. The patient received eight cycles of paclitaxel instillation over seven months. The compliance of the patient was excellent under therapy and her general condition improved significantly one and half year with a marked regression of the tumor masses after this treatment.

CONCLUSION

The combination of radiotherapy and intraperitoneal paclitaxel seems suitable in palliative settings primarily aimed at improving the quality of life.

Expression of PPARdelta in multistage carcinogenesis of the colorectum: implications of malignant cancer morphology

Whether peroxisome proliferator-activated receptor (PPAR) delta is a good target for the chemoprevention and/or treatment of colorectal cancer (CRC) remains controversial. Our goal was to examine PPARdelta expression in multistage carcinogenesis of the colorectum and to assess the relevance of PPARdelta in CRC. Immunohistochemical analysis indicated that PPARdelta expression increased from normal mucosa to adenomatous polyps to CRC. In cancer tissues, the PPARdelta protein was accumulated only in those cancer cells with highly malignant morphology, as represented by a large-sized nucleus, round-shaped nucleus, and presence of clear nucleoli. Interestingly, the cancer tissue often contained both PPARdelta-positive and -negative areas, each retaining their respective specific morphological features. Moreover, this pattern persisted even when PPARdelta-positive and -negative cells were aligned next to each other within a single cancer nest or gland and was present in the majority of CRC cases. Immunohistochemistry for Ki-67 proliferation marker showed no significant correlation between Ki-67 and PPARdelta in CRC samples. Based on Western blot analysis and quantitative RT-PCR, high PPARdelta protein expression correlated with high PPARdelta mRNA levels. Peroxisome proliferator-activated receptor delta may have a supporting role in tumorigenesis, and the close association between PPARdelta expression and malignant morphology of CRC cells suggests a pivotal role in cancer tissue.

High-rate pulmonary involvement in autoimmune pancreatitis

Autoimmune pancreatitis (AIP) has extrapancreatic complications such as Sjögren's syndrome, retroperitoneal fibrosis and sclerosing cholangitis. We studied 30 patients with AIP. Of these, we identified pulmonary involvement in four patients during follow up. Among them, two patients had respiratory failure. They showed good response to steroid therapy, but a higher dose of prednisolone was necessary to maintain remission than that required in biliary involvement. Elevation of immunoglobulin G(4) and Krebs von den Lungen-6 levels were characteristic of pulmonary involvement. They may be useful for early detection of pulmonary complication.

Uterine bizarre epithelioid lipoleiomyoma with a myxoid stroma

The first case of uterine bizarre epithelioid lipoleiomyoma with a myxoid component occurring in an 86-year-old woman is described. An intramural 22 cm mass in the anterior wall of the uterine body had a lipoma-like appearance with strands of fibrous tissue. Histologically, the tumor consisted of adipocytes which varied in size and shape, and epithelioid smooth muscle cells with nuclear atypia within a myxoid stroma. No mitotic features were noted despite an extensive search. The patient was well without disease 24 months after hysterectomy. Patients with this type of tumor need close and long-term follow-up because of the paucity of clinical information.

A prospective randomised study of "covered" versus "uncovered" diamond stents for the management of distal malignant biliary obstruction

BACKGROUND AND AIM

Covered self-expandable metal stents (EMS) were recently developed to overcome tumour ingrowth in conventional EMS. However, supporting evidence for the efficacy of covered EMS is lacking.

PATIENTS AND METHODS

We enrolled 112 patients with unresectable distal biliary malignancies. They were randomly assigned to polyurethane covered (n = 57) or original diamond stent (n = 55).

RESULTS

Stent occlusion occurred in eight patients (14%) after a mean of 304 days in the covered group, and in 21 patients (38%) after a mean of 166 days in the uncovered group. The incidence of covered EMS occlusion was significantly lower than that of uncovered EMS (p = 0.0032). The cumulative stent patency of covered stents was significantly higher than that of uncovered stents (p = 0.0066). No tumour ingrowth occurred in the covered group while it was observed in 15 patients in the uncovered group. In subgroup analysis, the cumulative patency of the covered EMS was significantly higher in pancreatic cancer (p = 0.0363) and metastatic lymph nodes (p = 0.0354). There was no significant difference in survival between the two groups. Acute cholecystitis was observed in two of the covered group and in none of the uncovered group. Mild pancreatitis occurred in five of the covered group and in one of the uncovered group.

CONCLUSIONS

Covered diamond stents successfully prevented tumour ingrowth and were significantly superior to uncovered stents for the treatment of patients with distal malignant biliary obstruction. However, careful attention must be paid to complications specific to covered self-expandable metal stents, such as acute cholecystitis and pancreatitis.

A case of aceruloplasminaemia: abnormal serum ceruloplasmin protein without ferroxidase activity

A 34 year old diabetic man with a complete deficiency of serum ferroxidase activity, regardless of the presence of serum ceruloplasmin (Cp), a multicopper ferroxidase protein, is described. The patient had had diabetes mellitus for 13 years, and was also found to have retinal degeneration accompanied by the development of a hearing disturbance of unknown aetiology. Laboratory examination showed markedly increased serum ferritin and low serum iron. Magnetic resonance imaging showed a pronounced hypointensity in the putamen, caudate, cerebellar dentate, and thalamus on T2 weighted images, and also disclosed a low level signal in the liver, suggesting the accumulation of some magnetic substances in the brain and liver. Liver biopsies histochemically identified iron deposition in the hepatocytes. Most of these findings were consistent with the newly established autosomal recessive disease "aceruloplasminaemia", except for the presence of serum Cp and the lack of apparent neurological symptoms. Interestingly, no ferroxidase activity was detected in the patient's serum, whereas suppressed ferroxidase activity was found in his mother's serum. A nucleotide sequence analysis of the Cp gene showed two mutations; a C to T substitution at nucleotide 2701 in exon 16, resulting in a nonsense mutation at amino acid 882 (Arg882ter), and a T to G substitution at nucleotide 2991 in exon 17, resulting in an amino acid alternation at amino acid 978 (His978Gln). The second mutation was also found in the patient's mother. The absence of serum ferroxidase activity despite the presence of serum Cp protein in this compound heterozygote was considered to be due to the production of a non-functional Cp harbouring no ferroxidase activity.

A phosphodiesterase inhibitor, cilostazol, prevents the onset of silent brain infarction in Japanese subjects with Type II diabetes

AIMS/HYPOTHESIS

This study aimed to evaluate the effect of a phosphodiesterase inhibitor, cilostazol, on the prevention of silent brain infarction in diabetic patients without symptoms of vascular events.

METHODS

A total of 89 subjects were allocated at random to the cilostazol group ( n = 43) or the control group ( n = 46).

RESULTS

After the study period (3.2 +/- 0.5 years), carotid intima-media thickness (IMT) (means +/- SD) had increased ( p < 0.01) by 0.18 +/- 0.19 mm in the control group. In the cilostazol group, intima-media thickness showed almost no change (-0.00 +/- 0.16 mm). In the control group, 2 out of 46 subjects showed symptomatic brain infarctions and 10 out of 34 subjects without infarct-like region assessed by standard brain MRI examination showed silent brain infarctions after the observation period. On the other hand, no subjects in the cilostazol group showed silent brain infarction or strokes during the study period. Both at the beginning and end of the study period, the number of infarct-like regions positively correlated with IMT ( r = 0.335, p < 0.001 or r = 0.347, p < 0.001 respectively). The progression of infarct-like regions was directly related to the increase in IMT during the study period ( r = 0.299, p = 0.004).

CONCLUSION/INTERPRETATION

These data demonstrated that cilostazol could prevent the onset of silent brain infarction in Japanese subjects with Type II (non-insulin-dependent) diabetes mellitus. Also, an increase in intima-media thickness of the carotid artery wall could be able to predict the onset of silent brain infarction.

Enantiodivergent synthesis of either enantiomer of ABCDE-ring analogue of antitumor antibiotic fredericamycin A via intramolecular [4 + 2] cycloaddition approach

[reaction: see text] An intramolecular enantiodivergent synthesis of both enantiomers of the ABCDE-ring analogue 22 of fredericamycin A is reported. Key steps involve an intramolecular [4 + 2] cycloaddition of 17 and an aromatic Pummerer-type reaction of 19. A lipase-catalyzed enantioselective desymmetrization of prochiral diol 2 using 1-ethoxyvinyl 2-furoate 3 led to the pivotal intermediate (R)-4.

Taurine prevents the decrease in expression and secretion of extracellular superoxide dismutase induced by homocysteine: amelioration of homocysteine-induced endoplasmic reticulum stress by taurine

BACKGROUND

Hyperhomocysteinemia is an independent risk factor for atherosclerosis. Homocysteine has been shown to induce endoplasmic reticulum (ER) stress in vascular endothelial cells. ER stress is a condition in which glycoprotein trafficking is disrupted and unfolded proteins accumulate in the ER. ER molecular chaperons, such as GRP78, are induced and an ER resident kinase, PERK, is activated when cells are subjected to ER stress. Conversely, taurine is reported to have antiatherogenic effects by unknown mechanisms. To elucidate the mechanisms by which homocysteine induces atherosclerosis and taurine prevents it, we examined whether homocysteine and taurine affect the expression and secretion of extracellular superoxide dismutase (EC-SOD), a glycoprotein secreted from vascular smooth muscle cells (VSMCs) that protects the vascular wall from oxidative stress.

METHODS AND RESULTS

We assessed the expression of EC-SOD and GRP78 mRNA in cultured rat VSMCs by Northern blot analysis. The EC-SOD protein secreted into the culture medium was examined by Western blot analysis. Homocysteine (5 mmol/L) and other ER stress inducers, including A23187, were found to decrease EC-SOD mRNA expression and protein secretion. Furthermore, they upregulated GRP78 mRNA expression and activated PERK. Taurine (0.5 to 10 mmol/L), conversely, prevented these actions induced by homocysteine.

CONCLUSIONS

Homocysteine induces ER stress and reduces the secretion and expression of EC-SOD in VSMCs, leading to increased oxidative stress in the vascular wall. Taurine restores the secretion and expression of EC-SOD by ameliorating ER stress induced by homocysteine.