The first evidence of paralytic shellfish toxins in the fresh water cyanobacterium Cylindrospermopsis raciborskii, isolated from Brazil

The blooms of toxic cyanobacteria (blue-green algae) are causing problems in many countries. During a screening of toxic freshwater cyanobacteria in Brazil, three strains isolated from the State of Sao Paulo were found toxic by the mouse bioassay. They all were identified as Cylindrospermopsis raciborskii by a close morphological examination. Extracts of cultured cells caused acute death to mice when injected intraperitoneally after developing neurotoxic symptoms which resembled to those caused by paralytic shellfish toxins. The analysis of the sample by HPLC-FLD postcolumn derivatization method for paralytic shellfish toxins resulted in the detection of several saxitoxin analogs. To avoid being misled by false peaks, the sample was reanalyzed after purification and also under the different postcolumn derivatizing conditions. Finally, the newly developed LC-MS method for paralytic shellfish toxins was applied to unambiguously identify the toxins. One isolate produced neosaxitoxin predominantly with saxitoxin as a minor component. The other two showed identical toxin profiles containing saxitoxin and gonyautoxins 2/3 isomers in the ratio of 1:9. This is the first evidence of paralytic shellfish toxins in this species and also the occurrence of the toxin producing cyanobacterium in South American countries.

Brevetoxin B4 isolated from greenshell mussels Perna canaliculus, the major toxin involved in neurotoxic shellfish poisoning in New Zealand

A new brevetoxin B analog, brevetoxin B4 (BTXB4), was isolated as the major toxin in greenshell mussels, Perna canaliculus, collected in New Zealand at the time of the neurotoxic shellfish poisoning incident. The new analog accounted for nearly two-thirds of the mouse lethality of the shellfish and was determined to be a mixture of N-myristoyl-BTXB2 and N-palmitoyl-BTXB2.

Inhibition of HIV/SIV replication by dominant negative Gag mutants

There are several major strategies against HIV/AIDS. Of these, the gene therapy is a novel, challenging, and promising one. The target genes, which have been extensively studied for the potential gene therapy of HIV/AIDS, include those of cellular and viral origins. Especially, trans-dominant negative Tat, Rev, Env, Pol, and Gag mutants of HIV have currently attracted considerable attention. In this brief review, we summarize the nature of the HIV/SIV mutants of this category and discuss their future use for gene therapy with special reference to the dominant negative Gag mutants of HIV-1.

New type of febrifugine analogues, bearing a quinolizidine moiety, show potent antimalarial activity against Plasmodium malaria parasite

Febrifugine (1) and isofebrifugine (2), isolated from the roots of Dichroa febrifuga Lour. (Chinese name: Cháng Shan), are active principles against malaria. Adducts of 1 and 2 with acetone, Df-1 (3) and Df-2 (4), respectively, were obtained using silica gel and acetone. They showed high activity against P. falciparum malaria in vitro. Compound 3 was found to be equally effective against P. berghei in vivo as the clinically used drug chloroquine, whereas 4 showed only 1/24 of the activity of 3. Metabolism studies of these compounds revealed that compound 4 is readily metabolized in mouse liver. Accordingly, the dose of 4 must be higher than that of 3 to attain blood levels sufficient for a favorable therapeutic effect.

Compatibility of Vpu-like activity in the four groups of primate immunodeficiency viruses

Env-minus mutants of the viruses of major four human and simian immunodeficiency viruses (HIVs and SIVs) were monitored for their progeny virion production upon transfection into the cells, which are dependent on the HIV-1 Vpu for efficient particle release. Of the env mutants of HIV-1 (one mutant), HIV-2/SIVmac (three mutants), SIVagm (one mutant), and SIVmnd (one mutant) examined, the mutant of SIVmnd generated a very low level of progeny virions similar to that by the HIV-1 Vpu-minus mutant. This effect of the mutation was not observed in the cells which are independent on the Vpu for virion release. The Env of SIVmnd efficiently enhanced virion release of heterologous viruses like the HIV-1 Vpu.

Surgery for mitral valve disease in the pediatric age group

OBJECTIVES

We reviewed a 20-year experience with the surgical treatment of mitral valve disease in the pediatric age group at our institution with 2 objectives: to clarify the long-term results over the last 2 decades and to evaluate the recent advances in mitral valve operation in children.

METHODS

Since December 1978, 56 patients have undergone a total of 36 mitral valve repairs and 30 mitral valve replacements. Associated cardiac anomalies were present in 46 patients (82%), and concurrent repair of associated lesions was performed in 37 patients (66%). The age of the patients ranged from 3 months to 15 years (mean, 3.6 years) at mitral valve repair, and ranged from 2 months to 16 years (mean, 5.7 years) at mitral valve replacement. Mean follow-up period was 92.0 months (range, 1-235 months).

RESULTS

There were 2 hospital deaths and 2 late deaths in patients who underwent mitral valve repair. Reoperation was performed in 4 patients. Three of these patients underwent mitral valve replacement because of residual mitral incompetence. No hospital deaths occurred in patients who underwent mitral valve replacement. Two late deaths occurred after mitral valve replacement. Six patients had a total of 10 episodes of prosthetic valve thrombosis. Thrombolytic therapy with urokinase was successful in all episodes without serious complications. Five patients required reoperations 49 to 141 months (mean, 78.4 months) after the initial valve replacement for relative prosthetic valve obstruction as the result of somatic growth. A valve 2 or 3 sizes larger than the original prostheses was inserted without death. Actuarial survival and freedom from cardiac events at 10 years after the operation were 87.2% and 72.7% in children who underwent mitral valve repair, and 90.3% and 67.3% for those children who underwent mitral valve replacement.

CONCLUSIONS

The current risk of mitral valve operation in the pediatric age group is low, and the long-term results are satisfactory, irrespective of severe deformation of the mitral valve apparatus and associated complex cardiac anomalies.

Cell-dependent replication potentials of HIV-1 gag mutants

An infectious molecular clone of human immunodeficiency virus type 1 (HIV-1), designated pNLaiKH, which is tropic for both lymphocytic and monocytic cells, was constructed. To study the early function of HIV-1 Gag proteins in two types of cells, the mutations known to give host cell-dependent early defects were introduced into pNLaiKH, and the replication potentials and defective replication sites in the cells of the resultant mutants were monitored. All mutants grew in some lymphocytic cells, but not at all in monocytic cells. A nucleocapsid mutant was found to be defective at an early replication phase in all the cell lines to various extent, as expected. In contrast, a matrix mutant and a capsid mutant displayed a replication defect in a producer-cell-dependent manner. These results demonstrated that complex interactions of cell factors and Gag proteins are involved in an early process of HIV-1 replication.

Optical cross-sectional assessment of the macula by retinal thickness analyzer in optic disk pit maculopathy

PURPOSE

To assess the morphologic changes in optic disk pit maculopathy.

METHOD

Case report. A 45-year-old woman with optic disk pit maculopathy in the left eye was examined with the scanning retinal thickness analyzer before and after vitrectomy with intravitreal gas tamponade.

RESULTS

Preoperatively, optical cross-sectional retinal thickness analyzer images clearly demonstrated the extent of retinoschisis and outer layer detachment in the macula. Postoperatively, the retinal thickness analyzer images showed that retinal thickening decreased as the intraretinal fluid in the schisis cavity was absorbed and then gradually decreased further as the outer layer detachment in the fovea resolved.

CONCLUSIONS

Scanning retinal thickness analyzer can be used to diagnose and monitor the structural changes of the macula lesion in optic disk pit maculopathy. Vitrectomy with gas tamponade may be effective for treating this disease.

The comparative benefits of glaucoma filtering surgery with an electric-pulse targeted drug delivery system demonstrated in an animal model

PURPOSE

To evaluate the safety and effectiveness of glaucoma filtering surgery performed with the adjunctive use of bleomycin administered in conjunction with electric pulses (EP).

DESIGN

Experimental study in rabbits. CONTROLS AND METHODS: Trabeculectomies were performed on pigmented rabbits (2 to 2.5 kg) using the following adjunctive treatments: 5 microM of topical bleomycin and EP (5V, 50 msec, 8 pulses) (group A: B+E+, n=15); bleomycin but no EP (group B: B+E-, n=15); 5 ,uM mitomycin C (MMC) and EP (group C: M+E+, n= 10); MMC but no EP (group D: M+E-, n=10); EP alone (group E: E+, n=10); and no adjunctive treatment (group F: E-, negative control, n=10).

MAIN OUTCOME MEASURES

Intraocular pressure (IOP) was measured regularly for 60 days after the operation. Bleb formation and the condition of the conjunctiva, cornea, and retina were also regularly evaluated. Histologic studies were performed by light microscopy, and retinal functions were evaluated by electroretinography.

RESULTS

Postoperative IOP was significantly lower than the preoperative level in all the animals until day 7. However, in groups E and F (the negative control) it returned to the preoperative level after day 7, and in groups B, C, and D after 15 days. The IOP of group A remained lower even on day 40. The average amount IOP was lowered or increased on day 20 was -6.4 mmHg (P < 0.05) in group A; -0.2 mmHg in group B; +1.2 mmHg in group C; and -3.25 mmHg in group D. The survival rate of the filtering blebs on day 20 was significantly higher in group A than in the other groups. Clinical and histologic studies uncovered no pathologic findings in any intra- or paraocular tissues. Electroretinographic evaluation of retinal function in group A showed no apparent change over the 60 days of the study.

CONCLUSION

Glaucoma filtering surgery in rabbits with the adjunctive use of bleomycin in conjunction with EP significantly lowered IOP for up to 40 days without clinically, morphologically, or functionally harming intraocular tissues.

Successful treatment of cytomegalovirus colitis with ganciclovir in a patient with adult T cell leukemia lymphoma: case report

An 84-year-old patient with adult T cell leukemia lymphoma (ATLL) developed diarrhea on day 5 of chemotherapy and was diagnosed with cytomegalovirus (CMV) colitis. Sigmoidoscopy revealed multiple superficial erosions surrounded by a flare. Computed tomography (CT) and ultrasonogram of the abdomen revealed marked thickening of the colonic mucosa. There were 186 CMV antigen-positive leukocytes per 31,000 white blood cells (WBC). A colonic biopsy specimen showed typical CMV nuclear inclusions. Immunohistological study of the specimen was positive for CMV antigen. Administration of ganciclovir (DHPG) 500 mg/day for 14 days improved the diarrhea and other symptoms. On day 30 of the chemotherapy, the patient developed diarrhea again but was diagnosed with pseudomembranous colitis instead of CMV colitis. At that time, CMV antigenemia and a histologic study for CMV were negative. The stool was positive for Clostridium difficile toxin antigen. ATLL patients are believed to be immunocompromised hosts and often develop opportunistic infections such as CMV infection. Most suffer from CMV pneumonia at the end of their course of therapy. Few gastrointestinal (GI) CMV infections are seen in ATLL patients and details of CMV colitis have never been reported. When an ATLL patient develops diarrhea that barely responds to conventional therapy, CMV colitis and pseudomembranous colitis should be listed in the differential diagnosis.

Intrahepatic venovenous shunting to an accessory hepatic vein after Fontan type operation

Because there are various types of systemic venous connections in patients with visceral heterotaxy, unanticipated abnormal systemic venous channels may pose additional problems after a Fontan type operation. We report a case of severe cyanosis caused by anomalous intrahepatic venovenous fistula to an accessory hepatic vein early after total cavopulmonary anastomosis.

Conversion of right atrioventricular to total cavopulmonary anastomosis in the management of post-Fontan arrhythmia: report of a case

Both the original and modified Fontan procedures are associated with several late complications such as atrial arrhythmias, thromboembolism, and right pulmonary vein compression caused by a markedly enlarged right atrium. We describe herein the case of a patient who underwent conversion of right atrioventricular to total cavopulmonary anastomosis to control atrial arrhythmia that developed 12 years after a modified Fontan operation. The procedure proved successful in alleviating his symptoms immediately. He is now doing well with no recurrence of atrial arrhythmia 1 year after the operation.

Cell-dependent functional roles of HIV-1 Nef for virus replication (review)

The stage in the human immunodeficiency virus type 1 (HIV-1) replication cycle that is affected by Nef has been investigated. Nef is dispensable during the transcription to virion production step. In contrast, Nef is critical in the early phase of the virus replication cycle, from virion adsorption to integration. Furthermore, virions produced in the absence of Nef have been demonstrated to be inefficient to complete the virus DNA synthesis. When virions are produced in particular cells without Nef, they exhibit a severe defect in the virus entry process into cells. Taken together, it is concluded that HIV-1 Nef acts via modulation of viral particles to enhance virus infectivity in a cell-dependent manner.

Stimulation of neurotrophic factor secretion from 1321N1 human astrocytoma cells by novel diterpenoids, scabronines A and G

Glial cells release neurotrophic factors that maintain neurons functionally. When rat pheochromocytoma cells (PC-12) were cultivated with the conditioned medium of human astrocytoma cells (1321N1) incubated with the new diterpenoids, scabronines A and G, isolated from Sarcodon scabrosus, they changed their morphology and there was neurite outgrowth. The scabronines increased the expression of mRNA for nerve growth factor (NGF), and the secretion of NGF from 1321N1 cells in a concentration-dependent manner. However, the enhanced neurite outgrowth produced by the conditioned media was slightly inhibited by NGF neutralizing antibody, and the concentration of NGF released in response to the scabronines was insufficient to cause differentiation. These results suggest that scabronines cause the secretion of other factors together with NGF from 1321N1 cells. The diterpenoids are useful drugs to clarify the mechanism of synthesis and secretion of neurotrophic factors.

[Macular morphologic reconstruction and visual recovery in patients following macular hole surgery]

PURPOSE

To examine the characteristics of retinal reconstruction at the macula following macular hole surgery and to assess the impact of postoperative macular morphological changes on the visual outcome.

METHODS

A prototype of the scanning retinal thickness analyzer (RTA) was used to obtain optical section images at the macula in 53 eyes of 52 patients who underwent macular hole surgery between April 1994 and July 1997. The mean age of participants was 64.7 years. At the time of RTA examination, macular hole was biomicroscopically closed in 49 eyes (91%) and unclosed in 5 eyes (9%).

RESULTS

There were 5 types of cross-sectional images of postoperative maculae: normal foveal depression [19 eyes (36%)], crater-like fovea formation [12 eyes (22%)], flattened fovea [8 eyes (15%)], fovea with abraded retinal pigment epithelium [9 eyes (17%)], and persistant macular hole [5 eyes (9%)]. Central macular thickness measured by RTA was 165 +/- 39 (mean +/- standard dereation) microns in the normal foveal depression group, 210 +/- 67 microns in the crater-like fovea formation group, and 300 +/- 50 microns in the flatened fovea group. There were statistically significant differences (p < 0.01) between groups. Postoperative visual acuity was significantly different (p < 0.01) between these three groups, and central macular thickness was highly correlated with postoperative visual acuity (R = 0.70).

CONCLUSION

Visual recovery following macular hole surgery is closely associated with the retinal reconstruction at the macula.

Survey of surgical indications and results of primary pars plana vitrectomy for rhegmatogenous retinal detachments

BACKGROUND

Several surgical techniques to repair rhegmatogenous retinal detachment have been developed. Recently, both the method of reattaching the retina and of obtaining an early visual recovery are considered important factors when determining which surgical techniques to perform to treat retinal detachment.

CASES

The surgical outcome in a series of 63 consecutive patients, who were treated at Osaka Rosai Hospital between 1993 and 1996, was reviewed retrospectively to evaluate the efficacy of primary vitrectomy to treat uncomplicated rhegmatogenous retinal detachment associated with posterior hyaloid separation. The criteria for vitrectomy included the presence of not only posterior retinal breaks, but also of multiple peripheral retinal breaks.

OBSERVATIONS

The reattachment rate after the first surgery was 92.1% (58 eyes), and by the final examination it increased to 100%. Of the 46 eyes with macular detachment, good visual rehabilitation and a visual acuity improvement of 5 or more lines was obtained in 33 eyes (71.7%) by 1 month postoperatively. No statistically significant difference in the reattachment rate was found when eyes that underwent an encircling procedure were compared with those that did not. In eyes with lens opacity, cataract surgery was also performed and intraocular lenses were implanted uneventfully in all but one case with myopia. There was a high incidence (53.8%) of cataract progression in phakic eyes. However, no other serious complications, such as proliferative vitreoretinopathy, were found throughout the follow-up period.

CONCLUSIONS

The results indicate that vitrectomy performed to alleviate peripheral vitreoretinal traction is an effective surgical technique to treat primary rhegmatogenous retinal detachment. Vitrectomy combined with cataract surgery may also be a valuable surgical option in selected cases to maintain long-standing visual rehabilitation.

[A comparative study of visual outcomes following primary vitrectomy and scleral buckling procedures to manage macular off rhegmatogenous retinal detachments]

PURPOSE

To determine the difference between two types of retinal detachment surgery in postoperative visual recovery in the management of macular-off rhegmatogenous retinal detachment.

METHODS

We evaluated retrospectively the postoperative visual acuity (VA) in 37 patients who underwent primary vitrectomy (group V) and 39 patients treated with conventional scleral buckling (group S).

RESULTS

Although the mean preoperative VA in group V (0.03) was significantly worse (p = 0.04) than that in group S (0.06), there was no statistically significant difference between the groups in postoperative VA throughout the follow-up period. However, in the cases with poor preoperative VA (VA < 0.1), ocular hypotony (IOP < 7 mmHg), or prolonged macular detachment (duration > 7 days), the visual recovery was significantly better (p < 0.05) in group V than in group S from 1 month postoperatively. There were more eyes with a final VA of more than 0.5 in group V than in group S. When considering only the eyes with lenses spared intraoperatively, postoperative cataract progression resulting in secondary visual reduction was statistically significantly greater (p < 0.01) in group V (62%) than in group S (8%).

CONCLUSIONS

Primary vitrectomy is effective to attain early visual rehabilitation, especially to manage macula-off retinal detachments with poor preoperative VA, ocular hypotony, and prolonged macular detachment. To prevent a secondary visual reduction, cataract surgery combined with vitrectomy is recommended in selected cases.

Activation of HIV-1 enhancer sequence by vaccinia virus

To investigate whether vaccinia virus (VV) can augment gene expression of human immunodeficiency virus type 1 (HIV-1), co-transfection experiments were carried out in which recombinant plasmids containing various portions of the HIV-1 long terminal repeat (LTR) linked to the chloramphenicol acetyltransferase (CAT) gene were transfected into cultured cells. A high level of enhancement in CAT activity directed by the HIV-1 LTRs containing the enhancer sequence was observed in cells infected with VV, as in the cells infected with type 1 herpes simplex virus (HSV-1). The sequence responsible for this augmentation of CAT activity was different from that recognized by HIV-1 Tat. These data clearly demonstrated that VV transactivates HIV-1 LTR through a mechanism distinct from that of activation by HIV-1 Tat.

Rev-dependent expression of three species of HIV-1 mRNAs (review)

The expression of structural and accessory genes of human immunodeficiency virus type 1 (HIV-1) except for nef requires a viral regulatory protein Rev. Rev-dependency of the expression of structural (gag, pol and env), regulatory (tat and rev), and accessory genes (vif, vpr, vpu and nef) has been investigated by various systems, and it has been demonstrated that unspliced (encodes gag and pol) and singly-spliced (env-vpu, vif and vpr) viral mRNAs are differentially dependent on the function of Rev. In this review, the function of HIV-1 Rev in relation to these findings is discussed.

Classic Blalock-Taussig shunt in neonates

BACKGROUND

The choice of palliative procedure for neonates with congenital cyanotic heart defects remains controversial. Several reports have questioned whether the classic Blalock-Taussig shunt is adequate in neonates, because it shows a high rate of mortality and early shunt failure. The purpose of this study is to evaluate the early and late results of classic Blalock-Taussig shunt in neonates.

METHODS

From December 1981 to December 1996, 31 neonates underwent a classic Blalock-Taussig shunt. Mean age at operation was 15.9 days (range, 2 to 28 days), and mean body weight was 3214 g (range, 2229 to 4468 g). The major diagnoses were pulmonary atresia with intact ventricular septum (6 patients) and with ventricular septal defect (4), univentricular heart (6), tricuspid atresia (5), tetralogy of Fallot (4), transposition of the great arteries (3), and double outlet right ventricle (3).

RESULTS

There were no early deaths. There was one early shunt failure. The patient underwent a replacement of Blalock-Taussig shunt by vascular graft on the 1st postoperative day. Two patients with non-confluent central pulmonary artery underwent a contralateral modified Blalock-Taussig shunt on the 22nd and 42nd postoperative day, respectively. There were two late deaths before the definitive repair was performed. Twelve patients required an additional shunt operation. The mean interval between the initial and the second shunt procedure was 27.7 months (range, 6 to 67 months). Ten patients underwent definitive operation and the mean interval to that procedure was 55.5 months (range, 14 to 121 months). Shunt patency was 94.7+/-5.1% at 3 years. The freedom from cardiac event (cardiac deaths or repeat shunting procedure) was 80.5+/-7.1% at 1 year and 54.9+/-9.4% at 3 years.

CONCLUSIONS

The classic Blalock-Taussig shunt has a low operative mortality and has provided excellent long-term palliation in the neonate. We conclude that a classic Blalock-Taussig shunt should be considered a reasonable choice in neonates requiring a palliative procedure for congenital cyanotic heart defects.

Growth characteristics of T-cell tropic HIV-1 vpu gene mutants in human peripheral blood mononuclear cells

A mutant designated NL-E65, which lacks the expression of entire vpu gene, was constructed from T-cell tropic wild-type (wt) human immunodeficiency virus type 1 (HIV-1) clone and monitored for its replication property in human cells, along with a mutant NL-Ss which expresses a C-terminal truncated Vpu. The mutant NL-Ss could grow in two cell lines and in all peripheral blood mononuclear cell (PBMC) preparations to some extent, with kinetics similar to those of wt virus. Likewise, the mutant NL-E65 exhibited a replication property typical to the vpu mutant in the two cell lines and in all PBMC cultures, growing at a low level. Along with the results previously reported, these data indicate that HIV-1 Vpu is dispensable for virus replication in any of the types of cells so far tested.

Exchangeability of accessory Vif and Vpu proteins between various HIV/SIVs (review)

Representative human and simian immunodeficiency viruses (HIV/SIVs) have been monitored for their Vif and Vpu activities in a wide variety of cells. In contrast to the prototype HIV-1, viruses of the other groups do not necessarily have these activities. Only HIV-2 and SIVmnd were clearly demonstrated to show the Vif and Vpu activities, respectively. The exchangeability of these accessory activities between viruses was then assessed to determine the relatedness of the viruses. Quite different from the results for Tat and Rev trans-activators, the activities are almost fully compatible between viruses. These results may facilitate the functional grouping of various HIV/SIVs.

Isolation of iron-oxidizing bacteria from corroded concretes of sewage treatment plants

Thirty-six strains of iron-oxidizing bacteria were isolated from corroded concrete samples obtained at eight sewage treatment plants in Japan. All of the strains isolated grew autotrophically in ferrous sulfate (3.0%), elemental sulfur (1.0%) and FeS (1.0%) media (pH 1.5). Washed intact cells of the 36 isolates had activities to oxidize both ferrous iron and elemental sulfur. Strain SNA-5, a representative of the isolated strains, was a gram-negative, rod-shaped bacterium (0.5-0.6x0.9-1.5 microm). The mean G+C content of its DNA was 55.9 mol%. The pH and temperature optima for growth were 1.5 and 30 degrees C, and the bacterium had activity to assimilate 14CO2 into the cells when ferrous iron or elemental sulfur was used as a sole source of energy. These results suggest that SNA-5 is Thiobacillus ferrooxidans strain. The pHs and numbers of iron-oxidizing bacteria in corroded concrete samples obtained by boring to depths of 0-1, 1-3, and 3-5 cm below the concrete surface were respectively 1.4, 1.7, and 2.0, and 1.2 x 10(8), 5 x 10(7), and 5 x 10(6) cells/g concrete. The degree of corrosion in the sample obtained nearest to the surface was more severe than in the deeper samples. The findings indicated that the levels of acidification and corrosion of the concrete structure corresponded with the number of iron-oxidizing bacteria in a concrete sample. Sulfuric acid produced by the chemolithoautotrophic sulfur-oxidizing bacterium Thiobacillus thiooxidansis known to induce concrete corrosion. Since not only T. thiooxidans but also T. ferrooxidans can oxidize reduced sulfur compounds and produce sulfuric acid, the results strongly suggest that T. ferrooxidans as well as T. thiooxidans is involved in concrete corrosion.

Clinical application of a nonpenetrating microvascular stapling device for vascularized free tissue transfer

It is essential to develop a method that is technically easier and faster to perform microvascular anastomosis. Therefore the authors have utilized a nonpenetrating microvascular stapling device (VCS; Auto Suture, Tokyo, Japan). Eight vascularized free tissue transfers were performed using this stapling device. All of the transferred tissues were grafted successfully. The time required to perform the stapled microvascular anastomosis ranged from 8 to 18 minutes (mean, 12 minutes). Two arterial anastomoses required suture repairs because they could not be repaired with the use of this stapling device due to thickened vessel walls and intimal dissections. The microvascular stapling device proved useful for vascularized free tissue transfers, but the vessels suitable for this technique should be chosen carefully. Not only the surgeon but also the assistant must be experienced in microscopic surgery.