[Pouchitis showed complete response to ustekinumab].

Pouchitis is the most common long-term complication following ileal pouch-anal anastomosis (IPAA) in patients with ulcerative colitis. Although several agents, including probiotics, steroids, and immunomodulators, have been used, the treatment of pouchitis remains challenging. Owing to the proven efficacy of biological therapy in inflammatory bowel disease, there is now growing evidence suggesting the potential benefits of biological therapy in refractory pouchitis. Here, we report the case of a 64-year-old woman with pouchitis due to ulcerative colitis who was successfully treated with ustekinumab (UST). The patient developed ulcerative pancolitis at the age of 35. Total colectomy and IPAA with J-pouch anastomosis were performed when the patient was 47 years old. Ileotomy closure was performed 6 months later. Postoperatively, the patient developed steroid-dependent pouchitis. Three years later, she developed steroid-induced diabetes. The patient has been taking 3mg of steroid for 20 years;therefore, her lifetime total steroid dose was 21g. The patient had over 20 episodes of bloody diarrhea a day. The last pouchoscopy in 20XX-9 revealed inflammatory stenosis with deep ulcerations of the afferent limb just before the ileoanal pouch junction. In July 20XX, when we took over her treatment, the policy of treatment was to withdraw her from steroids. Pouchoscopy revealed a widened but still tight afferent limb through which the scope could easily pass, and the ileoanal pouch still showed erosive ileitis without ulcers. Thiopurine administration and steroid tapering were initiated. Steroid tapering increased the erythrocyte sedimentation rate (ESR). As ESR increased, her arthritis exacerbated. Six months after the end of steroid administration, the patient consented to UST treatment. On April 20XX+1, the patient received her first 260-mg UST infusion. At this point, she experienced 14-15 episodes of muddy bloody stools. She had no abdominal pain;however, she experienced shoulder pain. Gradually, UST affected both pouchitis and arthritis. UST treatment was continued at 90mg subcutaneously every 12 weeks without abdominal pain recurrence. Eight months after the first UST infusion, nonsteroidal anti-inflammatory drugs were no longer necessary for shoulder pain. Follow-up pouchoscopy performed 14 months after UST optimization revealed a normal afferent limb without ulcerations in either segment. Pouchitis remission was maintained for over 2 years.

Therapy-related myeloid neoplasms after treatment for ovarian cancer: A retrospective single-center case series.

OBJECTIVE: Therapy-related myeloid neoplasms (t-MNs) are often fatal and arise as late complications of previous anticancer drug treatment. No single-center case series has examined t-MNs in epithelial ovarian cancer (EOC). METHODS: All patients with EOC treated at Chiba University Hospital between 2000 and 2021 were included. We retrospectively analyzed the characteristics, clinical course, and outcomes of patients who developed t-MNs. RESULTS: Among 895 cases with EOC, 814 cases were treated with anticancer drugs. The median follow-up period was 45 months (interquartile range, 27-81) months. Ten patients (1.2%) developed t-MNs (FIGO IIIA in one case, IIIC in three, IVA in one, and IVB in five). Nine patients were diagnosed with myelodysplastic syndrome and one with acute leukemia. One patient with myelodysplastic syndrome developed acute leukemia. The median time from the first chemotherapy administration to t-MN onset was 42 months (range, 21-94 months), with t-MN diagnoses resulting from pancytopenia in four cases, thrombocytopenia in three, and blast or abnormal cell morphology in four. The median number of previous treatment regimens was four (range, 1-7). Paclitaxel + carboplatin therapy was administered to all patients, gemcitabine and irinotecan combination therapy to nine, bevacizumab to eight, and olaparib to four. Six patients received chemotherapy for t-MN. All patients died (eight cancer-related deaths and two t-MN-related deaths). None of the patients was able to restart cancer treatment. The median survival time from t-MN onset was 4 months. CONCLUSIONS: Patients with EOC who developed t-MN were unable to restart cancer treatment and had a significantly worse prognosis.

Knowledge of mucin immunostaining status of "nuclear inverse polarity papillary lesions lacking myoepithelial cells" may prevent unnecessary breast surgery: experience of two cases.

We previously reported on two women with breast lesions in whom radiological examination could not exclude malignancy. In both cases, mastectomy was performed, and histological analyses revealed papillary lesions lined by fibrovascular stroma and nuclear inverse polarity. Hematoxylin-eosin, p63, and calponin staining indicated an absence of myoepithelial cells. However, it was concluded that the lesions had been non-malignant. These women have now been under long-term surveillance (74 months for one case and 62 months for the other) and have had no disease recurrence. Mucin (MUC)1, MUC2, MUC4, MUC5AC, MUC5B, and MUC6 immunostaining has also been performed in these women to investigate further whether their tumors were malignant or benign. In both cases, the tumors were only positive for MUC1 in apical luminal apical cells, as in normal breast tissue. MUC5B immunostaining, even when weak, can detect early breast cancer but was completely negative in our two cases. Therefore, both tumors were considered benign. Our findings in these cases suggest that nuclear inverse polarity papillary lesions lacking myoepithelial cells are benign. This knowledge should decrease the number of unnecessary operations performed for this tumor and their negative impact on patients' quality of life.

Synthesis of a Mechanically Planar Chiral and Axially Chiral [2]Rotaxane.

In this study, we synthesized a [2]rotaxane that was both mechanically planar chiral and axially chiral, comprising a symmetrical bis-crown ether featuring a biphenyl moiety (as the macrocyclic component) and a symmetrical bis-ammonium salt (as the dumbbell-shaped component).

A case of an atypical teratoid/rhabdoid tumor with distinctive histology in the pineal region in an adult patient.

A 31-year-old man suffered from headaches and presented at a hospital after the symptom worsened. Obstructive hydrocephalus and a pineal tumor were identified, and he was transferred to our hospital for further investigation and treatment. Cranial computed tomography revealed a hypodense mass lesion on the right of the pineal region, and calcifications and enlargement of the lateral and third cerebral ventricles were also evident. Blood tests were negative for all tumor markers. Laparoscopic biopsy and third-ventricle fenestration were performed that day as an emergency surgery to treat the obstructive hydrocephalus. Postoperative cranial magnetic resonance imaging revealed a solid tumor that was hypointense on T1-weighted imaging, hyperintense on T2-weighted imaging, and heterogeneously enhanced by Gd. Subsequently, the tumor increased in size, and craniotomy and tumorectomy were performed. Histologically, the tumor proliferated as round or short spindle-shaped cells in a myxoid matrix, forming arrays that surrounded the blood vessels. As a few cells with eosinophilic cytoplasm were also present and immunostaining for INI-1 was negative, the patient was diagnosed with atypical teratoid/rhabdoid tumor (AT/RT). AT/RT of the pineal region in adults is rare, and herein, we report the morphological characteristics of this case and reviewed the relevant literature.

Apparent diffusion coefficient (ADC) values of serous, endometrioid, and clear cell carcinoma of the ovary: pathological correlation.

BACKGROUND: Primary epithelial ovarian cancer is divided into several subtypes. The relationships between apparent diffusion coefficient (ADC) values and their subtypes have not yet been established. PURPOSE: To investigate whether ADC values of epithelial ovarian cancer vary according to histologic tumor cellularity and evaluate the difference of clear cell carcinoma (CCC), high-grade serous carcinoma (HGSC), and endometrioid carcinoma (EC). MATERIAL AND METHODS: This retrospective study included 51 cases of epithelial ovarian cancer (17 CCC, 20 HGSC, and 14 EC) identified by magnetic resonance imaging with pathological confirmation. All patients underwent diffusion-weighted imaging and the ADC values of lesions were measured. We counted the tumor cells in three high-power fields and calculated the average for each case. The Spearman's correlation coefficient test was used to analyze correlation between ADC values and tumor cellularity. The ADC values of HGSC, EC, and CCC were compared using the Steel-Dwass test. RESULTS: The ADC values of all cases were significantly inversely correlated with tumor cellularity (rs = -0.761; P < 0.001). The mean ± SD ADC values (×10-3 mm2/s) of CCC, HGSC, and EC were 1.24 ± 0.17 (range 0.98--1.65), 0.84 ± 0.10 (range 0.67--1.06), and 0.84 ± 0.10 (range 0.67--1.07). The mean ± SD tumor cellularity of CCC, HGSC, and EC was 162.88 ± 63.28 (range 90.33--305.67), 440.60 ± 119.86 (range 204.67--655.67), and 461.02 ± 81.86 (range 333.33--602.33). CONCLUSION: There is a significant inverse correlation between ADC values and tumor cellularity in epithelial ovarian cancer. The mean ADC value of CCC was higher than those of HGSC and EC, seemingly due to the low cellularity of CCC.

Use of immunohistochemical analysis of CK5/6, CK14, and CK34betaE12 in the differential diagnosis of solid papillary carcinoma in situ from intraductal papilloma with usual ductal hyperplasia of the breast.

OBJECTIVES: The aim of this study was to use immunohistochemistry to differentiate solid papillary carcinoma in situ from intraductal papilloma with usual ductal hyperplasia (IPUDH). Three types of high-molecular-weight cytokeratins (CKs) - CK5/6, CK14, and CK34betaE12 - were targeted. METHODS: We studied 17 patients with solid papillary carcinoma in situ and 18 patients with IPUDH diagnosed by at least two pathologists. Immunohistochemical analyses used antibodies to CK5/6, CK14, and CK34betaE12 to make the differential diagnosis of solid papillary carcinoma in situ versus IPUDH. Immunohistochemical staining was scored as 0-5 using Allred score. RESULTS: Immunohistochemistry with CK5/6 and CK14 antibodies produced scores of 0-3 in all patients with solid papillary carcinoma in situ and 2-5 in all patients with IPUDH. Immunohistochemical staining with CK34betaE12 antibody produced scores of 1-3 in all patients with solid papillary carcinoma and 3-5 in all patients with IPUDH. In tissues from patients with IPUDH, significantly more cells were stained with CK34betaE12 than CK5/6 (p < 0.05) or CK14 (p < 0.05). CONCLUSION: The immunoreactivity of CK5/6, CK14, and CK34betaE12 antibodies was useful to differentiate solid papillary carcinoma in situ from IPUDH. CK34betaE12 is especially useful for distinguishing solid papillary carcinoma from IPUDH.

Nuclear inverse polarity papillary lesions lacking myoepithelial cells: A report of two cases.

Here, cases of a 68- (Case 1) and a 44-year-old (Case 2) female are presented. They had an abnormality in the breast, and came to our hospital for further examination and treatment. Radiologically, malignancy could not completely excluded so breast excision was performed. Histologically, both cases revealed papillary neoplastic lesions lined by fibrovascular core and nuclear inverse polarity without atypia. Loss of myoepithelial cells was observed by HE, p63, and calponin. Previous report indicate CK5/6, ER, p63 and MUC3 are important for distinguishing between papillary lesions according to the differential index (based on Allred score) of ([ER total score] + [MUC3 total score])/([CK5/6 total score] + [p63 total score] + 1). Based on this analysis, our two cases had benign lesions. However, based on immunopositivity for cell-cycle marker Cyclin-D1, Case 1 was negative, and Case 2 was about 70% positive. Additionally, the Ki-67 index was <1% in both cases, and no evidence of disease was observed after a maximum 62 months of follow-up in both cases, despite lack of additional treatment. Thus, we propose that lack of myoepithelial cells in papillary lesions do not necessarily indicate malignancy and are thought to be, at the most, uncertain malignant potential.

Effectiveness of computer-aided diagnosis (CADx) of breast pathology using immunohistochemistry results of core needle biopsy samples for synaptophysin, oestrogen receptor and CK14/p63 for classification of epithelial proliferative lesions of the breast.

AIMS: The aim of this study was to develop a computer-aided diagnosis (CADx) system for identifying breast pathology. METHODS: Two sets of 100 consecutive core needle biopsy (CNB) specimens were collected for test and validation studies. All 200 CNB specimens were stained with antibodies targeting oestrogen receptor (ER), synaptophysin and CK14/p63. All stained slides were scanned in a whole-slide imaging system and photographed. The photographs were analysed using software to identify the proportions of tumour cells that were positive and negative for each marker. In the test study, the cut-off values for synaptophysin (negative and positive) and CK14/p63 (negative and positive) were decided using receiver operating characteristic (ROC) analysis. For ER analysis, samples were divided into groups with <10% positive or >10% positive cells and decided using receiver operating characteristic (ROC) analysis. Finally, these two groups categorised as ER-low, ER-intermediate (non-low and non-high) and ER-high groups. In the validation study, the second set of immunohistochemical slides were analysed using these cut-off values. RESULTS: The cut-off values for synaptophysin, <10% ER positive, >10% ER positive and CK14/p63 were 0.14%, 2.17%, 77.93% and 18.66%, respectively. The positive predictive value for malignancy (PPV) was 100% for synaptophysin-positive/ER-high/(CK14/p63)-any or synaptophysin-positive/ER-low/(CK14/p63)-any. The PPV was 25% for synaptophysin-positive/ER-intermediate/(CK14/p63)-positive. For synaptophysin-negative/(CK14/p63)-negative, the PPVs for ER-low, ER-intermediate and ER-high were 100%, 80.0% and 95.8%, respectively. The PPV was 4.5% for synaptophysin-negative/ER-intermediate/(CK14/p63)-positive. CONCLUSION: The CADx system was able to analyse sufficient data for all types of epithelial proliferative lesions of the breast including invasive breast cancer. This system may be useful for pathological diagnosis of breast CNB in routine investigations.

Can synaptophysin be used as a marker of breast cancer diagnosed by core-needle biopsy in epithelial proliferative diseases of the breast?

The differential diagnosis of epithelial proliferative disease using core needle biopsy (CNB) is problematic because it is difficult to differentiate between intraductal papilloma, ductal hyperplasia, ductal carcinoma in situ, and invasive ductal carcinoma. Many studies have reported that breast cancer lesions are positive for neuroendocrine (NE) markers, whereas only a small number of studies have reported immunopositivity for NE markers in normal mammary tissues or benign lesions. We asked whether NE factors could be used as markers of breast cancer. We determined the immunopositivity rate of synaptophysin, an NE marker, in 204 lesions excised from the breast using CNB in patients who visited a university-affiliated comprehensive medical facility and examined whether synaptophysin is a marker of breast cancer. The specimens were classified as synaptophysin-negative cases (56 benign, 99 malignant); equivocal cases (<1 %: 2 benign, 15 malignant); and synaptophysin-positive cases (1 benign, 31 malignant). The sensitivity, specificity, positive predictive value, and negative predictive value for malignancy of the lesions classified as synaptophysin positive were 23.3 %, 98.2 %, 96.9 %, and 36.1 %, respectively. The respective values for lesions classified as equivocal were 11.6 %, 96.6 %, 88.2 %, and 36.1 %. Synaptophysin may provide a marker of breast cancer diagnosed by CNB.

Epigenetic Regulation of the Blimp-1 Gene (Prdm1) in B Cells Involves Bach2 and Histone Deacetylase 3.

B lymphocyte-induced maturation protein 1 (Blimp-1) encoded by Prdm1 is a master regulator of plasma cell differentiation. The transcription factor Bach2 represses Blimp-1 expression in B cells to stall terminal differentiation, by which it supports reactions such as class switch recombination of the antibody genes. We found that histones H3 and H4 around the Prdm1 intron 5 Maf recognition element were acetylated at higher levels in X63/0 plasma cells expressing Blimp-1 than in BAL17 mature B cells lacking its expression. Conversely, methylation of H3-K9 was lower in X63/0 cells than BAL17 cells. Purification of the Bach2 complex in BAL17 cells revealed its interaction with histone deacetylase 3 (HDAC3), nuclear co-repressors NCoR1 and NCoR2, transducin ß-like 1X-linked (Tbl1x), and RAP1-interacting factor homolog (Rif1). Chromatin immunoprecipitation confirmed the binding of HDAC3 and Rif1 to the Prdm1 locus. Reduction of HDAC3 or NCoR1 expression by RNA interference in B cells resulted in an increased Prdm1 mRNA expression. Bach2 is suggested to cooperate with HDAC3-containing co-repressor complexes in B cells to regulate the stage-specific expression of Prdm1 by writing epigenetic modifications at the Prdm1 locus.

Endometrial cancer: correlation of apparent diffusion coefficient (ADC) with tumor cellularity and tumor grade.

BACKGROUND: Diffusion-weighted imaging (DWI) and the apparent diffusion coefficient (ADC) are widely used for detecting uterine endometrial cancer. The relationships between ADC values and pathological features of endometrial cancer have not yet been established. PURPOSE: To investigate whether ADC values of endometrial cancer vary according to histologic tumor cellularity and tumor grade. MATERIAL AND METHODS: We retrospectively reviewed 30 pathologically confirmed endometrial cancers. All patients underwent conventional non-enhanced magnetic resonance imaging (MRI) and DWI procedures, and ADC values were calculated. Tumor cellularity was evaluated by counting cancer cells in three high-power ( × 400) fields. The correlation between ADC values and tumor cellularity was assessed using Pearson's correlation coefficient test for statistical analysis. RESULTS: The mean ± standard deviation (SD) ADC value ( ×10(-3) mm(2)/s) of endometrial cancer was 0.85 ± 0.22 (range, 0.55-1.71). The mean ± SD tumor cellularity was 528.36 ± 16.89 (range, 298.0-763.6). ADC values were significantly inversely correlated with tumor cellularity. No significant relationship was observed between ADC values and tumor grade (mean ADC values: G1, 0.88 ± 0.265 × 10(-3) mm(2)/s; G2, 0.80 ± 0.178 × 10(-3) mm(2)/s; G3, 0.81 ± 0.117 × 10(-3) mm(2)/s). CONCLUSION: There is a significant inverse relationship between ADC values and tumor cellularity in endometrial cancer. No significant differences in average ADC value were observed between G1, G2, and G3 tumors. However, the lower the tumor grade, the wider the SD.

Comparison between Ki67 labeling index determined using image analysis software with virtual slide system and that determined visually in breast cancer.

BACKGROUND: In recent papers, Ki67 labeling index (LI) has been used to classify breast cancer patients into the low and high Ki67LI groups for comparison studies, which showed significant differences in many prognostic factors. It has not been clarified whether image analysis software can be used for calculating LI in breast cancer. In our study, we examined whether Ki67LI in breast cancer calculated using image analysis software correlates with that measured on the basis of visual. METHODS: Fifty patients were randomly selected among breast cancer patients who underwent surgical operation from March, 2010 to May, 2010 in our hospital without preoperative chemotherapy. In this study, for the virtual slide system (VSS: VS120-L100, Olympus, Tokyo, Japan), the high-resolution VSs of all the 50 patients were prepared as samples. The image analysis software use for calculating LI was Tissuemorph Digital Pathology (Tissuemorph DP: Visiopharm, Hoersholm, Denmark). The calculated LI was extracted from 3 to 5 views containing hot spots. The LI calculated using Tissuemorph DP was designed as LI/image/T. The digital image of 3 to 5 LI/image/T views was printed out, and on the digital photograph, we counted visually the number of Ki67-immunopositive cells in exactly the same area, and the percentage of Ki67-immunopositive cells was designed as LI/direct. Moreover, a pathologist's assistant (PA) determined the tumor area in the same specimen using VSS and calculated LI using Tissuemorph DP, which was designed as LI/image/PA. The chief pathologist (CP) similarly calculated LI which was designed as LI/image/CP. We evaluated the degree of agreement between different data sets "LI/image/T and LI/direct" and "LI/image/T, LI/image/CP, and LI/image/PA" by using interclass correlation coefficient (ICC). RESULTS: The average counts of cells were as follows: LI/direct, 3209.7 ± 1970.4 (SD); LI/image/T, 2601.6 ± 1697.1; LI/image/PA, 2886.5 ± 2027.5; LI/image/CP, 18805.5 ± 22293.4. The values of LI/direct and LI/image/T showed almost perfect agreement as showed by an ICC of 0.885 (95 % CI, 0.806-0.933; p < 0.001). The agreement among three investigators was almost perfect. The obtained ICC was 0.825 (95 % CI, 0.739-0.890; p < 0.001) among the data of LI/image/T, LI/image/CP and LI/image/PA. There were five cases that immunopositivity for Ki67 showed a more than 10 % disagreement between LI/direct and LI/image/T. CONCLUSION: The merits of calculating Ki67 LI using Tissuemorph DP are as follows. First, the staining intensity of the cells to be counted can be adjusted. Second, the portion of a tumor including "hot spots" for counting can be chosen. Third, many cancer cells can be counted more rapidly using Tissuemorph DP than by visual observation. However, it is important that pathologist should check and carry out the final decision of the data, when Ki67 LI using Tissuemorph DP is calculated.

Highly sensitive detection of platelet-derived growth factor on a functionalized diamond surface using aptamer sandwich design.

Aptamer-based fluorescence detection of platelet-derived growth factor (PDGF) on a functionalized diamond surface was demonstrated. In this work, a sandwich design based on the ability of PDGF to bind with aptamers at its two available binding sites was employed. It was found that this sandwich design approach significantly increases the fluorescence signal intensity, and thereby a very low detection limit of 4 pM was achieved. The effect of the ionic strength of MgCl(2) buffer solution was also investigated, and the most favourable binding for PDGF-BB occurred at a Mg(2+) concentration of 5.5 mM. Since the aptamers bind to the target PDGF with high affinity, fluorescence detection exhibited high selectivity towards different biomolecules. The high reproducibility of detection was confirmed by performing three cycles of measurements over a period of three days.

A case of a fibroadenoma coexisting with an invasive lobular carcinoma in the breast.

A case of a fibroadenoma coexisting with an invasive lobular carcinoma of the breast in a 60-year-old female is presented, and its pathological features are correlated with high-resolution magnetic resonance imaging (HR-MRI) and other imaging findings. The patient presented with the chief complaint of having a palpable mass in her right breast for 3 months. Mammography revealed a lobular mass with a micro-lobulated margin, which suggested a malignant nature; however, it included coarse calcifications. Sonographic imaging and HR-MRI findings were compatible with malignant tumor. Cytology was performed, and the results indicated an invasive carcinoma. Breast-conserving surgery was performed as a curative operation. The pathological features revealed a fibroadenoma coexisting with an invasive lobular carcinoma. This case suggests that radiologists should always pay attention to the associated malignant imaging characteristics, such as the shape and border of the mass, whenever a mass demonstrates benign-like calcifications.

Aptamer-based biosensor for sensitive PDGF detection using diamond transistor.

The detection of platelet-derived growth factor (PDGF) via a solution-gate field-effect transistor (SGFET) has been demonstrated for the first time using aptamers immobilized on a diamond surface. Upon introduction of PDGF to the immobilized aptamer, a shift of 31.7 mV in the negative direction is observed at a source-drain current of -50 µA. A shift of 32.3 mV in the positive direction is detected after regeneration by SDS solution, indicating that the static measurement returns to its original value. These SGFETs operate stably within the large potential window of diamond (>3.0 V), and hence the surface channel does not need passivating with a thick insulating layer. Thereof, the immobilized aptamer channels have been exposed directly to the electrolyte solution without a gate insulator. Immobilization is achieved via aptamers covalently bonding to amine sites, thereby increasing the sensitivity of the biosensors. Diamond SGFETs have potential for the detection of PDGF and show durability against biological degradation after repeated usage and regeneration.

Evaluation of CD56 and CD57 immunostainings for discrimination between endocrine ductal carcinoma in situ and intraductal papilloma.

Endocrine ductal carcinoma in situ (E-DCIS) is an intraductal carcinoma characterized by endocrine features and expression of neuroendocrine markers. E-DCIS and intraductal papilloma (IDP) resemble in their clinical features. However, the former is an intraductal carcinoma, and the latter is an intraductal benign lesion. It is sometimes difficult to distinguish E-DCIS from IDP because both can show near solid intraductal cellular proliferation. Discrimination between lesions is important not only histopathologically, but also clinically. This study aimed to evaluate the applicability of CD56 and CD57 for the discrimination between E-DCIS and IDP. Specimens were obtained from 17 E-DCIS patients as the subject group, and 27 IDP patients as the control group, diagnosed in St Marianna University Hospital. E-DCIS was diagnosed using Chromogranin A, Synaptophysin, and Grimelius stainings by the premise of histopathological features. These specimens were subjected to CD56, CD57 immunostainings. Staining results were compared between E-DCIS and IDP. In our study, CD56 revealed significant differences for distinguishing E-DCIS from IDP as determined by Fisher's test (cutoff: not less than 33-67%< immunopositivity, P < 0.05). We found that not only E-DCIS but also IDP revealed immunopositivity for CD56. However, it is considered that E-DCIS diagnosis is possible by diffuse immunopositivity of CD56 after having been based on histopathology.

Fabrication of biporous low-crystalline apatite based on mannitol dissolution from apatite cement.

Biporous (macro- and microporous) calcium phosphate gains much attention as a bone substitute material because of its large surface area and that it improves cell penetration. In the present study, we evaluated the feasibility of biporous, low-crystalline apatite based on dissolution of mannitol from self-setting apatite cement (Biopex). Mannitol--known as a biocompatible, easily dissolved monosaccharide alcohol--was recrystallized to obtain larger crystals. It was crushed with pestle and mortar, sieved to obtain crystals which passed through a 500-microm mesh but which remained against a 300-microm mesh, and then used as porogen. Although Biopex containing 60 wt% mannitol was not able to be taken out of the mold, addition of mannitol caused no initial setting inhibition to Biopex if the amount was 40 wt% or less. Similarly, transformation to apatitic product was confirmed when the apatite cement was immersed in 0.9% saline kept at 37 degrees C for seven days. The set mass became low-crystalline, biporous apatite with approximately 60% porosity.

Effects of added sodium alginate on mechanical strength of apatite cement.

Effects of added sodium alginate on the mechanical strength of Biopex, one type of apatite cement, were investigated since sodium alginate addition is very effective for Biopex to acquire anti-washout property. Addition of sodium alginate into the liquid phase of Biopex resulted in a slower transformation to apatitic monolith. As a result, mechanical strength of set Biopex in terms of diametral tensile strength (DTS) decreased when it was hardened in an incubator kept at 37 degrees C and 100% relative humidity for 7 days. However, DTS value increased with increase in the amount of added sodium alginate when the Biopex paste was immersed in 0.9% saline at 37 degrees C for 7 days. Set Biopex with less sodium alginate also showed larger porosity. Based on these findings, we concluded that added sodium alginate was effective in increasing the mechanical strength of Biopex by inhibiting liquid penetration into its paste when it is exposed to body fluids.