The effect of synthetic octacalcium phosphate in a collagen scaffold on the osteogenicity of mesenchymal stem cells

Although the efficacy of the in vivo osteogenic capabilities of synthetic octacalcium phosphate (OCP) crystal implantation can be explained through its stimulatory capacity for the differentiation of the host osteoblastic cell lineage, direct evidence that OCP supports bone regeneration by osteogenic cells in vivo has not been shown. Mesenchymal stem cells (MSCs) isolated from 4-week-old male Wistar rat long bones were pre-incubated in osteogenic or maintenance medium in the presence or absence of basic fibroblast growth factor (bFGF). OCP/Collagen (OCP/Col) or collagen disks were seeded with MSCs that had been pre-incubated in osteogenic medium containing bFGF, which exhibited the highest differentiation induction, and then incubated for an additional day. The disks were implanted in critical-sized calvaria defects of 12-week-old male Wistar rats and the specimens were analysed radiographically, histologically, histomorphometrically, and by micro-computed tomography (CT) imaging at 4 and 8 weeks after the implantation. The OCP/Col·MSCs group rapidly induced more bone regeneration, even within 4 weeks, compared to the OCP/Col group without MSCs. The bone mineral density of the OCP/Col·MSCs group was also greater than the OCP/Col group. The Col·MSCs group did not exhibit prominent osteogenicity. These results indicate that OCP crystals in a collagen matrix efficiently promote exogenously introduced osteogenic cells to initiate bone regeneration if the cells are pre-treated in a suitable differentiation condition.

Use of quantitative intra-operative electrodiagnosis during partial ulnar nerve transfer to restore elbow flexion

The transfer of part of the ulnar nerve to the musculocutaneous nerve, first described by Oberlin, can restore flexion of the elbow following brachial plexus injury. In this study we evaluated the additional benefits and effectiveness of quantitative electrodiagnosis to select a donor fascicle. Eight patients who had undergone transfer of a simple fascicle of the ulnar nerve to the motor branch of the musculocutaneous nerve were evaluated. In two early patients electrodiagnosis had not been used. In the remaining six patients, however, all fascicles of the ulnar nerve were separated and electrodiagnosis was performed after stimulation with a commercially available electromyographic system. In these procedures, recording electrodes were placed in flexor carpi ulnaris and the first dorsal interosseous. A single fascicle in the flexor carpi ulnaris in which a high amplitude had been recorded was selected as a donor and transferred to the musculocutaneous nerve. In the two patients who had not undergone electrodiagnosis, the recovery of biceps proved insufficient for normal use. Conversely, in the six patients in whom quantitative electrodiagnosis was used, elbow flexion recovered to an M4 level.

Quantitative intra-operative electrodiagnosis is an effective method of selecting a favourable donor fascicle during the Oberlin procedure. Moreover, fascicles showing a high-amplitude in reading flexor carpi ulnaris are donor nerves that can restore normal elbow flexion without intrinsic loss.

94 EFFECT OF OVARIAN SIZE ON THE VIABILITY OF CRYOPRESERVED SYRIAN HAMSTER OVARIES

Ovaries can be used in place of gametes as a resource for cryopreservation. Thus far, we have shown that in the Syrian hamster, pups can be successfully produced through the transplantation of fresh and cryopreserved ovaries. In this study, we attempted to simplify the ovarian cryopreservation procedures to facilitate the easy application of these techniques. In particular, the procedure would be easier and quicker if the ovaries did not have to be cut into small pieces before ovarian cryopreservation. Therefore, we examined the effects of ovarian fragment size on subsequent offspring production. Ovaries were cryopreserved by vitrification according to methods described for mouse ovaries (Migishima et al. 2003 Biol. Reprod. 68, 881–887). In brief, ovaries were collected from 3-week-old J2N-n strain (white coat) females. Because we had previously confirmed that quarter-sized ovaries could be used for cryopreservation, intact (∼3.5 × 2 mm) and half-sliced ovaries (∼2 × 1.5 mm) were cryopreserved by vitrification using DAP213 solution (2 M dimethyl sulfoxide, 1 M acetamide, and 3 M propylene glycol; Nakagata 1989 J. Reprod. Fertil. 87, 479–483). Thawed ovaries were transferred into the ovarian bursae (single intact ovary or two half-sliced ovarian pieces per ovarian bursa) of 3-week-old recipient females with agouti-coat (Slc:Syrian) under isoflurane anaesthesia. Not all of the recipients’ ovaries were removed immediately before transfer; both the donor’s and a small portion of the recipient’s ovaries were present in each ovarian bursa. Successful ovarian transplantation was verified by examining the coat colour (non-agouti colour) of offspring produced in test matings between mature recipients and J2N-n males. Of the 3 and 6 recipients that received intact and sliced ovaries, respectively, 2 and 5 recipients delivered pups. Based on the coat colour of the pups, 1 of the 5 recipients delivered a pup produced from transplanted half-sliced ovaries. Our results indicate that half-sliced-size ovaries (smaller than a 2-mm cube) can be successfully used for cryopreservation in the Syrian hamster. Specifically, it is not required to slice the ovary into smaller pieces. This work was supported by a grant from the Ministry of Health, Labour and Welfare, Japan and Grant-in-Aid for Scientific Research (C).

Bone regeneration by octacalcium phosphate collagen composites in a dog alveolar cleft model

Octacalcium phosphate (OCP) and porcine atelocollagen sponge composites (OCP/Col) markedly enhanced bone regeneration in a rat cranial defect model. To assess clinical application, the authors examined whether OCP/Col would enhance bone regeneration in an alveolar cleft model in an adult dog, which was assumed to reflect patients with alveolar cleft. Disks of OCP/Col or collagen were implanted into the defect and bone regeneration by OCP/Col or collagen was investigated 4 months after implantation. Macroscopically, the OCP/Col-treated alveolus was obviously augmented and occupied by radio-opacity, and the border between the original bone and the defect was indistinguishable. Histological analysis revealed it was filled and bridged with newly formed bone; a small quantity of the remaining implanted OCP was observed. X-ray diffraction patterns of the area of implanted OCP/Col indicated no difference from those of dog bone. In the collagen-treated alveolus, the hollowed alveolus was mainly filled with fibrous connective tissue, and a small amount of new bone was observed at the defect margin. These results suggest that bone was obviously repaired when OCP/Col was implanted into the alveolar cleft model in a dog, and OCP/Col would be a significant bone regenerative material to substitute for autogeneous bone.

Octacalcium phosphate: osteoconductivity and crystal chemistry

Octacalcium phosphate (OCP), which is structurally similar to hydroxyapatite (HA), is a possible precursor of bone apatite crystals. Although disagreement remains as to whether OCP comprises the initial mineral crystals in the early stage of bone mineralization, the results of recent biomaterial studies using synthetic OCP indicate the potential role of OCP as a bone substitute material, owing to its highly osteoconductive and biodegradable characteristics. OCP tends to convert to HA not only in an in vitro environment, but also as an implant in bone defects. Several lines of evidence from both in vivo and in vitro studies suggest that the conversion process could be involved in the stimulatory capacity of OCP for osteoblastic differentiation and osteoclast formation. However, the osteoconductivity of OCP cannot always be secured if an OCP with distinct crystal characteristics is used, because the stoichiometry and microstructure of OCP crystals greatly affect bone-regenerative properties. Osteoconductivity and stimulatory capabilities may be caused by the chemical characteristics of OCP, which allows the release or exchange of calcium and phosphate ions with the surrounding of this salt, and its tendency to grow towards specific crystal faces, which could be a variable of the synthesis condition. This paper reviews the effect of calcium phosphates on osteoblastic activity and bone regeneration, with a special emphasis on OCP, since OCP seems to be performing better than other calcium phosphates in vivo.

A double-suicide autopsy case of potassium poisoning by intravenous administration of potassium aspartate after intake of some psychopharmaceuticals

We report a curious double-suicide autopsy case of both male and female who died of potassium poisoning by intravenous administration of concentrated potassium aspartate solution. The plasma concentrations of potassium of the male and female subjects were as high as 49.7 and 62.8 mEq/L, respectively. In addition to the high concentrations of potassium, toxic levels of phenobarbital, promethazine and chlorpromazine, and relatively low levels of etizolam and brotizolam were also detected from whole blood and urine specimens of both cadavers. Twenty empty plastic bottles (10-mL capacity) labeled ‘ASPARA® Potassium Injection 10 mEq’ were found at the suicide spot. To our knowledge, this is the first description for suicidal death by potassium aspartate; in all of the previous literature, they used potassium chloride intravenously or per os.

Appositional Bone Formation by OCP-Collagen Composite

Synthetic octacalcium phosphate (OCP) has been shown to enhance bone formation and to biodegrade if implanted into bone defects. Here, we hypothesized that an OCP-atelocollagen complex (OCP/Col) is biodegradable and can induce bone formation in a thickness-dependent manner when implanted into the calvaria. OCP/Col disks (diameter, 9 mm; thickness, 1 or 3 mm) were implanted into a subperiosteal pocket in the calvaria of 12-week-old Wistar rats for 4, 8, and 12 weeks and subsequent bone formation was monitored. X-ray diffraction analysis and Fourier transform infrared spectroscopy showed that OCP in the OCP/Col implants was converted into a carbonate-rich apatite after 4 weeks. Although thinner disks tended to be replaced by new bone, thicker disks were progressively resorbed by osteoclast-like cells until 12 weeks, possibly via the increased mechanical load in the subperiosteal pocket. Therefore, OCP/Col can increase appositional intra-membranous bone formation if the appropriate size of the implant is applied.

Curative intended radiation therapy for young patients with invasive uterine cervical carcinoma: Clinical outcomes in 105 patients in a Japanese multi-institutional study

e16558

Background: Recently, the number of young patients with invasive uterine cervical carcinoma is increasing in Japan because of earlier sexual activity and low rate of receiving screening test of uterine cervical carcinoma in Japan. However, no large studies have been performed so far to evaluate the clinical outcomes of curative intended radiation therapy for young patients with invasive uterine cervical carcinoma in Japan. Then, the current study was designed. Methods: One hundred and five patients under 40 years old were registered in the mulitiinstitutional study. The median age was 34.5 years old (range: 24–39 years old). According to FIGO, clinical stage was as follows. Stage Ib/IIa/IIb/IIIa/IIIb/IVa were 10/4/38/2/47/3, respectively. The median maximal tumor diameter was 5.5 cm (range: 2–9.2 cm). Curative intended radiation therapy was the combination of high-dose rate intracavitary brachytherapy (HDR-ICBT) combined with external beam radiation therapy (ERT). The total dose of ERT ranged from 44 Gy to 68 Gy. The total dose of HDR-ICBT to point A ranged from 12 Gy to 48 Gy. Eighty five patients received chemotherapy. Results: The 5-year overall survival rate and local control rate of all patients was 58.4 % and 59.3 %, respectively. The 5-year overall survival rates of stage Ib/IIa/IIb/IIIa/IIIb/IVa were 90.0 %/not available (NA)/73.8%/100%/37.4%/0%, respectively. The 5-year local control rates of Stage Ib/IIa/IIb/IIIa/IIIb/IVa were 80.0 %/50.0 %/73.8 %/100 %/54.6 %/NA, respectively. Sixteen patients experienced grade 3 or greater late radiation morbidity. Conclusions: Clinical outcomes of stage I-II in the young were equivalent to the Japanese standard treatment results of all ages. However, clinical outcomes of stage IIIb and IVa in the young were worse than those of all ages (5-year OS of all ages in Japan: IIIb: 50 %, IVa: 25 %).

No significant financial relationships to disclose.

First Report of Colletotrichum boninense Causing Anthracnose on Pepper in Brazil

Colletotrichum boninense was isolated from pepper (Capsicum annuum) fruits (cv. Amanda) with preharvest anthracnose symptoms collected in the Brazilian states of Rio Grande do Sul and São Paulo in July of 2005. In the field, the disease affected mature fruits and leaves with an incidence near 25%. Typical symptoms in fruits were circular, sunken lesions with orange spore masses in a dark center. Three single conidia isolates were obtained from infected fruits. When grown on potato dextrose agar at 25°C with a 12-h photoperiod, these isolates produced white colonies with a cream-to-orange color in the opposite side, but no sclerotia. Conidia were cylindrical, had obtuse ends and a hilum-like low protuberance at the base, and measured 13.5 to 15.5 × 4.6 to 5.1 μm. Conidial length/width ratio was 2.8 to 3.0. These morphological characteristics are consistent with the description of C. boninense (1). To confirm pathogen identity, the internal transcribed spacer rRNA region was sequenced (GenBank Accession Nos. FJ010199, FJ010200, and FJ010201) and compared with the same region of C. boninense (GenBank Accession No. DQ286160.1). Similarity between these sequences was 98 to 99%. The pathogenicity of the three isolates was determined on pepper fruits cv. Amanda. Attached as well as detached fruits from potted plants were inoculated. Inoculation was performed by depositing 40-μl droplets of a suspension (10⁵ conidia per ml) on the surfaces of nonwounded (detached n = 5; attached n = 5) and wounded (detached n = 5; attached n = 5) fruits with a sterilized hypodermic needle. Incubation took place in a moist chamber for 12 days at 25°C with a 12-h photoperiod. Inoculation of control fruits was similar in procedure and number to that of test fruits, except sterile distilled water was used instead of the conidial suspension. Symptoms, observed in wounded and nonwounded test fruits 3 to 5 days after inoculation, were characterized by necrotic, sunken zones containing acervuli, black setae, and orange spore masses. Control fruits presented no symptoms. Pathogens reisolated from infected fruits showed the same morphological and molecular characteristics of the isolates previously inoculated. To our knowledge, this is the first report of C. boninense infecting pepper in Brazil. Reference: (1) J. Moriwaki et al. Mycoscience 44:47, 2003.

77 SUCCESSFUL CRYOPRESERVATION OF SYRIAN HAMSTER OVARIES BY VITRIFICATION

In place of gametes, ovaries can be used as an alternative resource for cryopreservation. At the previous IETS meeting, we showed that in the Syrian hamster, pups could be successfully produced through the transplantation of fresh ovaries. In addition, the immunotolerance of interstrain ovarian transplantation was described. In this study, we attempted to produce pups via transplantation of cryopreserved ovaries to foster mothers. Our goal was to establish a preservation method for hamster strains based on ovarian cryopreservation in combination with ovarian transfer. Ovaries were cryopreserved by vitrification according to methods described for mouse ovaries (Migishima F et al. 2003 Biol. Reprod. 68, 881–887). In brief, ovaries were collected from 2- to 3-week-old HAW strain (white coat) females. Each ovary was cut into 4 sections, placed into 1 tube, and cryopreserved by vitrification using DAP213 solution (2 m dimethyl sulfoxide, 1 m acetamide, and 3 m propylene glycol; Nakagata N 1989 J. Reprod. Fertil. 87, 479–483). Thawed ovaries were transferred into the ovarian bursae (2 ovarian sections per ovarian bursa) of 3-week-old recipient females with agouti coat (Slc:Syrian) under anesthesia with isoflurane. Half of the recipients’ ovaries were removed immediately before transfer; i.e. both donor and recipient ovaries were present in each ovarian bursa. Successful ovarian transplantation was verified by examining the coat color (non-agouti color) of offspring produced in test matings between mature recipients and Slc:Syrian males. Out of 6 recipients tested, 2 became pregnant and delivered pups. According to the coat color of the pups, 1 of the 2 recipients delivered a pup produced from transplanted ovaries (1 out of 4 pups). Regardless of this low success rate, our results indicate that pups can be produced from cryopreserved ovaries via interstrain transplantation of ovaries to foster mothers in the Syrian hamster. Thus, ovarian cryopreservation by vitrification is a promising strategy for strain preservation of the Syrian hamster. This work was supported by a grant from the Ministry of Health, Labor, and Welfare, Japan.

Efficacy of the electrothermal bipolar vessel sealer in laparoscopic spleen-preserving distal pancreatectomy with conservation of the splenic artery and vein

INTRODUCTION

Laparoscopic spleen-preserving distal pancreatectomy (LSPDP) with conservation of the splenic artery and vein has recently been performed as a minimally invasive surgery to retain splenic function in the treatment of pancreatic diseases. As the branches of the splenic vessels are very delicate, division of these branches increases the risk of bleeding.

MATERIALS AND METHODS

To overcome this problem, we have used the electrothermal bipolar vessel sealer (EBVS) to divide branches of the splenic vessels in LSPDP while conserving the splenic vessels themselves.

RESULTS

The EBVS reliably provided excellent and safe hemostasis, minimizing the risk of serious blood loss.

CONCLUSION

Use of the EBVS is safe and efficient in LSPDP with conservation of the splenic vessels.

Analysis of appositional bone formation using a novel rat experimental model

AIM

To analyze the process of appositional bone formation using our original rat experimental model.

MATERIALS AND METHODS

Rats were anesthetized and a ring made of polytetrafluorethylene was placed on the parietal bone surface in the surgical procedure. The time course of appositional bone formation was analyzed with histomorphometry and in situ hybridization for type I collagen and bone sialoprotein.

RESULTS

The rat experimental model allowed new bone to be formed on the pre-existing bone surface and persist for 12 weeks. We demonstrated that bone is apposed actively for the first 4 weeks and less actively thereafter.

CONCLUSIONS

The experimental model may contribute to biological analysis for appositional bone formation expected to occur in clinical procedures such as alveolar bone augmentation and sinus lifting.

Bone regeneration by synthetic octacalcium phosphate and its role in biological mineralization

Octacalcium phosphate (Ca8H2(PO4)6 * 5H2O; OCP) has been advocated to be a precursor of biological apatite crystals in bone and tooth. Recent studies, using physical techniques, showed that OCP is present as a transient phase during biological apatite formation in human dentin, porcine enamel and murine bone. However, there is still a controversy regarding the chemical nature of the first mineral formed in the biominerals. A number of studies have demonstrated that synthetic OCP shows bone regenerative and biodegradable characteristics, rather than other calcium phosphate bone substitute materials, such as hydroxyapatite (Ca10(PO4)6(OH)2; HA) ceramic. It seems likely that synthetic OCP may be an alternative to autogenous bone graft. It is known that OCP contains alternative layers of water molecules and an apatite structure, and that the transition of OCP to HA is likely to be spontaneous and irreversible. The conversion process induces modification of local environment adjacent to OCP surface, including the changes in adsorption of serum proteins and concentration of calcium and inorganic phosphate ions. This article reviews the possible application to bone regeneration by synthetic OCP and the mechanism to enhance bone regeneration in relation to biological mineralization in bone and tooth.

Computed tomography evaluation of regional lymph node metastases in patients with biliary cancer

BACKGROUND

Identification of lymph node metastases in biliary cancer is important for determining prognosis and surgical planning, but the effectiveness of computed tomography (CT) in diagnosing node metastases of the hepatoduodenal ligament (peribiliary and retroportal nodes) or around the common hepatic artery is unknown.

METHODS

CT scans and pathological results from 146 patients who had undergone regional lymphadenectomy for biliary carcinoma were reviewed. To evaluate the regional lymph nodes, long- and short-axis diameters of lymph nodes were measured and axial ratios calculated (short-axis diameter/long-axis diameter). Nodes were considered round if the axial ratio exceeded 0.7. Internal lymph node structures were also evaluated.

RESULTS

The presence of a round node with a short-axis diameter exceeding 16 mm had a positive predictive value (PPV) of 56 per cent for the presence of metastatic foci, and node heterogeneity had a PPV of 64 per cent. The highest PPV (67 per cent) was obtained for round nodes greater than 18 mm in short-axis diameter, but nodes of this size and character were rare.

CONCLUSION

CT is not useful for predicting regional lymph nodal metastases in biliary carcinoma.