Shoki Mikata

Splenic artery embolization using contour emboli before laparoscopic or laparoscopically assisted splenectomy.

The present study assessed preoperative splenic artery embolization using spherical embolic material, super absorbent polymer microspheres (SAP-MS), before laparoscopic or laparoscopically assisted splenectomy. Distal splenic artery embolization using 250 to 400 &mgr;m SAP-MS was performed in nine cases with ITP and in seven cases with the other diseases with splenomegaly. Laparoscopic or laparoscopically assisted splenectomies, including a hand-assisted procedure and the procedure involving left upper minilaparotomy, were done 2 to 4 hours after embolization. Conversion to traditional laparotomy was not required in any of the 16 cases, while conversion to 12-cm laparotomy was required in one case with massive splenomegaly. Mean operating time was 161 minutes, and mean intraoperative blood loss was 290 mL. No major postoperative complications were identified, and only one patient reported postembolic pain before surgery. Preoperative splenic artery embolization using painless embolic material, SAP-MS, would be effective for easy and safe laparoscopic or laparoscopically assisted splenectomy.

Regulation of complement-mediated swine endothelial cell lysis by a surface-bound form of human C4b binding protein.

BACKGROUND Human C4b-binding protein (C4bp) functions as a cofactor for factor I in the degradation of C4b and C3b and, in addition, accelerates the rate of decay of the C4b2a complex. METHODS In this study, we constructed a surface-bound form of human C4b-binding protein (C4bp-PI) consisting of a short consensus repeat 1-8 of the alpha-chain of C4bp and a glycosyl phosphatidylinositol (GPI) of the decay-accelerating factor (CD55) and established stable swine endothelial cell (SEC) lines expressing C4bp-PI by transfection of cDNA. Amelioration of complement-mediated lysis by the transfectant molecules was tested as an in vitro hyperacute rejection model of swine to human discordant xenograft, using the lactate dehydrogenase assay. RESULTS Flow cytometric profiles of the stable SEC lines with C4bp-PI showed a high level of expression of this molecule. The cell lysate of the SEC line with C4bp-PI showed strong cofactor activity in not only C4b but also C3b, whereas the activity of plasma C4bp to bind to C3 was very weak. Approximately 150 x 10(4) molecules of C4bp-PI per SEC blocked human complement-mediated cell lysis by approximately 75%. CONCLUSIONS The results suggest that the surface-bound form of C4bp will be very useful in clinical xenotransplantation.

Laparoscopically assisted splenectomy following preoperative splenic artery embolization using contour emboli for myelofibrosis with massive splenomegaly.

Laparoscopically assisted splenectomy with an 8- to 10-cm left upper paramedian laparotomy was performed following preoperative splenic artery embolization using painless contour emboli (super absorbent polymer microsphere) with early successful results in two men (46 and 37 years old) with myelofibrosis accompanied by massive splenomegaly. Dissection around the lower part of the spleen and the hilum initially was performed intracorporeally with the usual laparoscopic view under 12 mm Hg pneumoperitoneum. The alternating changes of viewpoints between the direct view through an 8- to 10-cm incision and the usual laparoscopic view with or without application of a retraction method were effective for safe hilar devascularization. Preoperative splenic artery embolization at the distal site was effective for safe dissection around the enlarged spleen. The patients did not complain of pain before operation. Preoperative painless embolization and laparoscopically assisted splenectomy with small laparotomy promotes the feasibility and safety of minimally invasive splenectomy for myelofibrosis with massive splenomegaly.

Prevention of hyperacute rejection by phosphatidylinositol-anchored mini-complement receptor type 1.

Complement receptor type 1 (CR1, CD35) contains both factor I cofactor activity and convertase decay accelerating activity, but is, in general, thought to be an extrinsic regulator of complement activation. In this study, we prepared a phosphatidylinositol (PI)-anchored mini-CR1, which is composed of the short consensus repeat (SCR) 8-11 of CR1 and the PI anchor of DAF, and expressed it stably on a swine endothelial cell (SEC) line. We then examined the intrinsic regulatory activity of the mini-CR1, with respect to complement-mediated cell lysis as an in vitro hyperacute rejection model of a swine to human discordant xenograft. Flowcytometric profiles of the stable SEC lines with mini-CR1 showed a moderate level of expression for this molecule. Mini-CR1 blocked human complement-mediated cell lysis by approximately 50-70% on SEC. From the data of this study and our previous studies, mini-CR1 was more effective than membrane cofactor protein (MCP, CD46), and as effective as decay accelerating factor (DAF, CD55) in this system. The results suggest that PI-anchored mini-CR1 represents a useful molecule for clinical xenotransplantation.

Laparoscopic resection of intra-abdominal esophageal duplication cyst.

&NA; Esophageal duplication cysts are frequently encountered in the mediastinum and rarely in the abdomen. A case of laparoscopic resection of an intra‐abdominal esophageal duplication cyst is reported. An incidental 4.5 × 4.0 × 3.5‐cm, wellcircumscribed, homogenous mass anterior to the intra‐abdominal esophagus was detected on staging CT examinations for breast cancer in a 51‐year‐old woman. Laparoscopic resection of the lesion was performed after completion of breast‐conserving surgery and whole breast irradiation. The defect of the muscular layer of the esophagus caused by the complete removal of the lesion required repair with muscular sutures. It was helpful to inspect the integrity of the esophageal wall repair by examining the exterior wall of the esophagus laparoscopically while insufflating air into the esophageal lumen through a fiberoptic esophagoscope. A laparoscopic approach utilizing intraoperative esophagoscopy is easy and safe for removal of intra‐abdominal esophageal duplication cysts.

Reduced thiamine (vitamin B1) levels following gastrectomy for gastric cancer

Abstract.Abstract.Background: Vitamin B1 deficiency is well known as a possible complication following gastric restrictive surgery for morbid obesity; however, reduced vitamin B1 levels in patients who have undergone gastrectomy for gastric cancer have not been discussed previously.Methods: Serum vitamin B1 levels were determined after the return to normal daily activity in 54 patients with distal gastrectomy for gastric cancer, 32 patients with total gastrectomy for gastric cancer, and 30 patients with radical surgery for colorectal cancer. Changes from serum vitamin B1 levels before operation to those after return to normal daily activity, without nutritional support, were investigated in 25 patients with gastrectomy for gastric cancer and 26 patients with radical surgery for colorectal cancer.Results: Decreased serum vitamin B1 levels, below the normal range, were recognized in 7 of the 54 distally gastrectomized patients and in 5 of the 32 totally gastrectomized patients, whereas no such decrease was recognized in any patient after colorectal surgery. Decreased serum vitamin B1 level was recognized within 6 months after the operation in 6 of the 7 distally gastrectomized patients showing a decreased vitamin B1 level and in 3 of the 5 totally gastrectomized patients showing a decreased vitamin B1 level. Postoperative serum vitamin B1 levels were significantly lower than those before operation in patients with gastrectomies, whereas there was no significant difference in serum vitamin B1 levels before and after the surgeries in patients with surgery for colorectal cancer.Conclusion: Vitamin B1 levels may be reduced in gastrectomized patients, especially within 6 months after operation, even after their return to normal daily activity without nutritional support.

A monomeric human C4b-binding protein (C4bp) more efficiently inactivates C3b than natural C4bp : participation of C-terminal domains in factor I-cofactor activity

We designed a cDNA construct encoding an artificial membrane molecule consisting of all 8 short consensus repeats (SCRs) of human monomeric C4b-binding protein (C4bp) followed by DAFs GPI anchor, named mC4bp, and expressed the protein on swine endothelial cells (SEC). At the same level of expression, mC4bp protected host cells as effectively as DAF, the most potent complement (C) regulator on the membrane. This result was unexpected from the reported functional properties of natural multimeric C4bp. Here, we investigated the mechanism whereby mC4bp has potent cell-protective activity. Our results were as follows: (1) mC4bp serves more efficiently as a methylamine-treated C3 (C3ma)-inactivating factor I-cofactor than natural C4bp and as efficiently as MCP as a methylamine-treated (C4ma)-inactivating cofactor by fluid-phase cofactor assay: (2) the potency of C3ma inactivation by mC4bp and factor I is quite high compared to those of other cofactors: (3)blocking studies using mAbs against C4bp suggested that both the 48 kDa N-terminal fragment and the C-terminal domain near the portion responsible for bundle formation participate in the high C3ma-inactivating capacity of mC4bp. Thus, acquiring high C3ma-inactivating capacity secondary to monomeric alteration leads to high C regulatory activity of mC4bp. These results infer that mC4bp differs from C4bp in its potent factor I-cofactor activity and is a good candidate as a safeguard against hyperacute rejection of xenografts.

C5b-8 Step Lysis of Swine Endothelial Cells by Human Complement and Functional Feature of Transfected CD59

The authors established several swine endothelial cell (SEC) lines expressing human CD59 by transfection of cDNA, and assessed the function of the transfectant molecules in comparison with those of membrane cofactor protein (MCP) and decay‐accelerating factor (DAF) in an in vitro hyperacute rejection model of swine to human discordant xenograft. At the usual expression rate, DAF and MCP protected SEC from human complement mediated cell lysis, but CD59 did not block human complement attack on SEC. However, CD59 protects SEC from cell lysis when sufficiently expressed as in human umbilical vein (HUVEC). The authors examined why CD59 needed so many molecules to protect human complement‐mediated SEC lysis and found that SEC underwent lysis by human C5b‐8. The degree of C5b‐8 step lysis of SEC was approximately 70% of the total activity (C5b‐9). Additionally, CD59 protected human complement activation less efficiently at the C5b‐8 step than at the C9‐step. Therefore, to overcome human complement mediated SEC lysis, C8 activity must be inhibited by dense expression of CD59.

Essential initial immunostimulation in graft coronary arteriosclerosis induction detected by retransplantation technique in rats : the participation of T cell subsets

Graft coronary arteriosclerosis occurs as chronic rejection after heart transplantation. In the previous studies, we have examined the minimum period of allogeneic stimulation to induce this change, using heterotopic rat heart transplantation and a retransplantation model. Retransplantation of allografts back into the donor strain did not prevent graft arteriosclerosis if the grafts had resided in the primary recipient for up to five days. In this study, the participation of the T cell subset causing graft coronary arteriosclerotic change was assessed using the same model. The transplanted rats in fully allogeneic or non-MHC antigen mismatch combinations were treated with a short-course administration of FK506. The graft was removed and retransplanted into the donor strain rats to escape from further immunological stimulation. CD4+ T cells and/or CD8+ T cells of first recipient rats in both combinations were eliminated by monoclonal antibodies. The grade of arteriosclerosis in the retransplanted hearts was evaluated on a basis of a scale from 0-4 according to the histological appearance of the vessel injury on day 40 after initial engraftment. While neither anti-CD4 nor anti-CD8 monoclonal antibody alone had little effect, the administration of both mAbs reduced this arteriosclerotic change and development. In conclusion, the T cell subsets, CD4+ T cell and CD8+ T cell play a certain role in the induction of the graft coronary arteriosclerotic change.

Ileal Perforation Due to a Richter Hernia at the Drain Insertion Site Following an Operation for Idiopathic Rectal Perforation: Report of a Case

Abstract: A case of a Richter hernia at the insertion site of the drainage tube following open abdominal surgery is reported. A 54-year-old man underwent an emergency operation for an idiopathic rectal perforation. A partial resection of the rectum and drainage using four 10-mm (outer diameter) drainage tubes with round cross sections was performed. Despite an uneventful early postoperative course, an emergency reoperation was required for peritonitis due to a bowel perforation 14 days after removing the drain inserted into the rectosacral space. A laparotomy revealed an incarcerated Richter hernia with ileal perforation through the 10-mm drainage site. The postoperative course after a partial resection of the ileum and drainage with Penrose drains was uneventful. This is the first report of a Richter hernia through the insertion site of a drainage tube in abdominal surgery. The possible occurrence of a Richter hernia in cases with postoperative drainage using large-size round drainage tubes should thus be considered in such patients.