Synthesis of a fluorescent photoaffinity probe of OSW-1 by site-selective acylation of an inactive congener and biological evaluation

A novel fluorescent photoaffinity probe of OSW-1 was prepared in two steps from a naturally occurring inactive congener by a sequential site-selective acylation strategy using Me₂SnCl₂. It displayed highly potent anticancer activity and a similar intracellular localization property to that of a fluorescently-tagged OSW-1, thereby demonstrating its potential utility in live cell studies.

Correction: Synthesis of a fluorescent photoaffinity probe of OSW-1 by site-selective acylation of an inactive congener and biological evaluation

Correction for ‘Synthesis of a fluorescent photoaffinity probe of OSW-1 by site-selective acylation of an inactive congener and biological evaluation’ by K. Sakurai et al., Chem. Commun., 2017, DOI: 10.1039/c6cc08955k.

Prostacyclin Analogue (Beraprost) Relief of Cold Intolerance After Digital Replantation and Revascularization

Cold intolerance frequently occurs after successful digital revascularization and replantation. A series of 11 patients with cold intolerance 6 to 24 months after digital revascularization/replantation were treated daily for 2 weeks with beraprost, a stable prostacyclin analogue. That pain was reduced in 9 of 11 cases after treatment and digital thermography showed significantly increased surface temperature after the 2-week course of beraprost. These findings support the use of beraprost to relieve symptoms of cold intolerance under these clinical conditions.

Tissue engineering a human phalanx

A principal purpose of tissue engineering is the augmentation, repair or replacement of diseased or injured human tissue. This study was undertaken to determine whether human biopsies as a cell source could be utilized for successful engineering of human phalanges consisting of both bone and cartilage. This paper reports the use of cadaveric human chondrocytes and periosteum as a model for the development of phalanx constructs. Two factors, osteogenic protein-1 [OP-1/bone morphogenetic protein-7 (BMP7)], alone or combined with insulin-like growth factor (IGF-1), were examined for their potential enhancement of chondrocytes and their secreted extracellular matrices. Design of the study included culture of chondrocytes and periosteum on biodegradable polyglycolic acid (PGA) and poly-l-lactic acid (PLLA)-poly-ε-caprolactone (PCL) scaffolds and subsequent implantation in athymic nu/nu (nude) mice for 5, 20, 40 and 60 weeks. Engineered constructs retrieved from mice were characterized with regard to genotype and phenotype as a function of developmental (implantation) time. Assessments included gross observation, X-ray radiography or microcomputed tomography, histology and gene expression. The resulting data showed that human cell-scaffold constructs could be successfully developed over 60 weeks, despite variability in donor age. Cartilage formation of the distal phalanx models enhanced with both OP-1 and IGF-1 yielded more cells and extracellular matrix (collagen and proteoglycans) than control chondrocytes without added factors. Summary data demonstrated that human distal phalanx models utilizing cadaveric chondrocytes and periosteum were successfully fabricated and OP-1 and OP-1/IGF-1 accelerated construct development and mineralization. The results suggest that similar engineering and transplantation of human autologous tissues in patients are clinically feasible. Copyright © 2016 John Wiley & Sons, Ltd.

Effect of local environment, fibrin, and basic fibroblast growth factor incorporation on a canine autologous model of bioengineered cartilage tissue

We developed a technique to form a bioabsorbable synthetic polymer (polyglycolic acid, PGA) combined with a natural polymer (fibrin) to serve as a scaffold to help retain seeded cells and improve the seeding efficiency of chondrocytes in an implantable construct. This approach was evaluated in a canine autologous implant model of bioengineered cartilage. The implantation site (subcutaneous or intrafascial) and the use of basic fibroblast growth factor (b-FGF) were also evaluated with this system. The intrafascial implantation site yielded optimal results, especially when used in conjunction with fibrin and a b-FGF sustained-release system incorporated into the complex. A thicker, more sustained cartilagenous layer was formed, with a more vascularized outer fibrous supporting tissue layer. This combined approach of implant environment selection, natural polymer for cell retention, and growth factor supplementation offers a more optimized method for generating bioengineered auricular cartilage.

Effect of Escherichia coli wild type or its derivative with high nitrite reductase activity on in vitro ruminal methanogenesis and nitrate/nitrite reduction

The effects of two kinds of Escherichia coli strains, wild-type E. coli W3110 or E. coli nir-Ptac, which has enhanced nitrite reduction activity, on in vitro CH4 production and nitrate and nitrite reduction in cultures of mixed ruminal microorganisms was investigated using continuous incubation systems. Escherichia coli nir-Ptac, a derivative of wild-type E. coli W3110, was constructed by replacing self promoter of nir BD operon encoding subunits of nitrite reductase in E. coli W3110 by tac promoter to make the expression of nir BD higher and constitutive. The nitrite reductase activity of E. coli nir-Ptac was approximately twice as high as E. coli W3110. The culture media consisted of 400 mL of strained ruminal fluid taken from two nonlactating Holstein cows receiving a basal diet of orchardgrass hay at maintenance level (55 g of DM/kg of BW0.75 daily), and 400 mL of autoclaved artificial saliva. Treatments were arranged in two separate 3 x 3 factorials consisting of nitrate (NaNO3; 0, 5, or 10 mM) without E. coli or inoculated with E. coli W3110 or E. coli nir-Ptac, or nitrite (NaNO2; 0, 1 or 2 mM) without E. coli or inoculated with E. coli W3110 or E. coli nir-Ptac. The control culture contained no chemical or microbial additives. Escherichia coli cells were inoculated into in vitro mixed ruminal cultures at approximately 2 x 10(8) to 10(9) cells/mL. Methane production by ruminal microorganisms was decreased markedly (P < 0.001) by the addition of nitrate and nitrite, and by the inoculation of cultures with E. coli W3110 or E. coli nir-Ptac (P < 0.01). With mixed nitrite-containing cultures, E. coli nir-Ptac inhibited (P < 0.001) in vitro nitrite accumulation and CH4 production more than E. coli W3110, which may be due to the tac promoter-enhanced nitrite reductase activity of E. coli nir-Ptac accelerating electrons to be consumed for nitrite reduction rather than CH4 biosynthesis. In conclusion, anaerobic cultures of E. coli W3110 or E. coli nir-Ptac may decrease CH4 production in the rumen. The inoculation of E. coli W3110 or, especially, E. coli nir-Ptac to mixed ruminal microorganisms may decrease nitrite toxicity when ruminants consume high-nitrate-containing forages and when nitrite is applied to abate ruminal CH4 production.

Effect of ruminal administration ofEscherichia coliwild type or a genetically modified strain with enhanced high nitrite reductase activity on methane emission and nitrate toxicity in nitrate-infused sheep

The effects of two kinds ofEscherichia coli(E. coli) strain, wild-typeE. coliW3110 andE. colinir-Ptac, which has enhanced NO2reduction activity, on oral CH4emission and NO3toxicity in NO3-treated sheep were assessed in a respiratory hood system in a 4×6 Youden square design. NO3(1·3g NaNO3/kg0·75body weight) and/orE. colistrains were delivered into the rumen through a fistula as a single dose 30min after the morning meal.Escherichia colicells were inoculated for sheep to provide an initialE. colicell density of optical density at 660nm of 2, which corresponded to 2×1010cells/ml. The six treatments consisted of saline,E. coliW3110,E. colinir-Ptac, NO3, NO3plusE. coliW3110, and NO3plusE. colinir-Ptac. CH4emission from sheep was reduced by the inoculation ofE. coliW3110 orE. colinir-Ptac by 6% and 12%, respectively. NO3markedly inhibited CH4emission from sheep. Compared with sheep given NO3alone, the inoculation ofE. coliW3110 to NO3-infused sheep lessened ruminal and plasma toxic NO2accumulation and blood methaemoglobin production, while keeping ruminal methanogenesis low. Ruminal and plasma toxic NO2accumulation and blood methaemoglobin production in sheep were unaffected by the inoculation ofE. colinir-Ptac. These results suggest that ruminal methanogenesis may be reduced by the inoculation ofE. coliW3110 orE. colinir-Ptac. The inoculation ofE. coliW3110 may abate NO3toxicity when NO3is used to inhibit CH4emission from ruminants.

Design and assessment of a tissue-engineered model of human phalanges and a small joint

OBJECTIVES

To develop models of human phalanges and small joints by suturing different cell-polymer constructs that are then implanted in athymic (nude) mice.

DESIGN

Models consisted of bovine periosteum, cartilage, and/or tendon cells seeded onto biodegradable polymer scaffolds of either polyglycolic acid (PGA) or copolymers of PGA and poly-L-lactic acid (PLLA) or poly-epsilon-caprolactone (PCL) and PLLA. Constructs were fabricated to produce a distal phalanx, middle phalanx, or distal interphalangeal joint.

SETTING AND SAMPLE POPULATION

Studies of more than 250 harvested implants were conducted at the Northeastern Ohio Universities College of Medicine.

EXPERIMENTAL VARIABLE

Polymer scaffold, cell type, and implantation time were examined.

OUTCOME MEASURE

Tissue-engineered specimens were characterized by histology, transmission electron microscopy, in situ hybridization, laser capture microdissection and qualitative and quantitative polymerase chain reaction analysis, magnetic resonance microscopy, and X-ray microtomography.

RESULTS

Over periods to 60 weeks of implantation, constructs developed through vascularity from host mice; formed new cartilage, bone, and/or tendon; expressed characteristic genes of bovine origin, including type I, II and X collagen, osteopontin, aggrecan, biglycan, and bone sialoprotein; secreted corresponding proteins; responded to applied mechanical stimuli; and maintained shapes of human phalanges with small joints.

CONCLUSION

Results give insight into construct processes of tissue regeneration and development and suggest more complete tissue-engineered cartilage, bone, and tendon models. These should have significant future scientific and clinical applications in medicine, including their use in plastic surgery, orthopaedics, craniofacial reconstruction, and teratology.

Thrombosis and altered expression of intercellular adhesion molecule-1 (ICAM-1) after avulsion injury in rat vessels

This study was undertaken to characterize the relative degrees of arterial and venous trauma after graded avulsion injuries. Rat femoral arteries and veins were subjected to reproducible avulsion injuries using forces of between 60 and 220g. Thrombotic occlusion occurred at lower avulsion forces in veins than in arteries. Histologic and scanning electron microscopic analysis indicated increased endothelial disruption and exposed elastic lamina with increasing avulsion force in both vessels, but more prominently in arteries. Intercellular adhesion molecule-1 (ICAM-1) mRNA expression was evident at 3 and 6 hours after avulsion injury in veins, but only with higher avulsion-force injuries in arteries. ICAM-1 mRNA expression was not found in either vessel before or after this 3 to 6 hour post-injury interval. These results indicate that the amount of avulsion force to which traumatized extremity vessels are subjected has a direct effect on the degree of intimal injury and subsequent thrombosis.

Disseminated scleroderma of a Japanese patient successfully treated with bath PUVA photochemotherapy

BACKGROUND

Localized scleroderma is known to be resistant to therapies. Recently, it has been reported that bath PUVA photochemotherapy is effective for treating this dermatosis.

OBJECTIVES

Although according in earlier reports mainly white populations have been treated successfully with bath PUVA therapy, there is little knowledge of whether it is effective in treating colored populations. We treated a 64-year-old Japanese woman suffering from disseminated scleroderma with bath PUVA photochemotherapy to see its effects.

CONCLUSION

Although rather high cumulative UVA doses were required for this patient compared with those needed in earlier reports, no adverse effects were observed. The lesions were markedly improved, suggesting that this therapeutic modality is well-tolerated and useful for colored patients such as the Japanese. Furthermore, it turns out that the thermographical assessment is useful to estimate clinical improvement of this sclerosing skin disorder.

Experimental use of fibrin glue to induce site-directed osteogenesis from cultured periosteal cells

The purpose of this study was to determine whether a combination of fibrin glue and cultured periosteal cells will result in new bone formation at heterotopic sites in nude mice. Growing cells and developing matrices surrounding periosteal explants from the diaphyses of radii of newborn calves were minced and mixed with fibrin glue in a syringe. The cell/matrix-fibrin glue admixture was then injected into the subcutaneous space on the dorsum of athymic nude mice. After 12 weeks of implantation, gross morphology and histologic investigations showed newly formed bone structures in all cell/matrix-fibrin glue admixtures, but none in fibrin glue injected alone and used as control samples. Osteopontin, a protein important in bone development, was identified by a Western blot assay of the cell/matrix-fibrin glue composite. This study supports the feasibility of initiating site-directed formation of bone structures at heterotopic tissue sites by means of injection of cultured periosteal cells and matrix in a fibrin glue carrier.

[Tissue engineering]

The new field of tissue engineering, applies the principles of biology and engineering to the development of functional substitutes for the loss or failure of an organ or tissue. This article describes the previous challenges and present status of this interdisciplinary field.

Formation of phalanges and small joints by tissue-engineering

BACKGROUND

This report describes the formation of small phalanges and whole joints from three types of bovine-cell sources transplanted onto biodegradable polymer matrices. The resulting structures had the shape and composition of human phalanges with joints.

METHODS

Fresh bovine periosteum was wrapped around a copolymer of polyglycolic and poly-L-lactic acid. Separate sheets of polyglycolic acid polymer were then seeded with chondrocytes and tenocytes isolated from the shoulders of freshly killed calves. The gross form of a composite tissue structure was constituted in vitro by assembling the parts and suturing them to create models of a distal phalanx, a middle phalanx, and a distal interphalangeal joint.

RESULTS

Subcutaneous implantation of the sutured composite tissues into athymic mice resulted in the formation, after twenty weeks, of new tissue with the shape and dimensions of human phalanges with joints. Histological examination revealed mature articular cartilage and subchondral bone with a tenocapsule that had a structure similar to that of human phalanges and joints. There was continuous cell differentiation at the ectopic site even after extended periods.

CONCLUSIONS

These findings suggest that the formation of phalanges and small joints is possible with the selective placement of periosteum, chondrocytes, and tenocytes into a biodegradable synthetic polymer scaffold.

Creation of viable pulmonary artery autografts through tissue engineering

BACKGROUND

"Repair" of many congenital cardiac defects requires the use of conduits to establish right ventricle to pulmonary artery continuity. At present, available homografts or prosthetic conduits lack growth potential and can become obstructed by tissue ingrowth or calcification leading to the need for multiple conduit replacements. Tissue engineering is an approach by which cells are grown in vitro onto biodegradable polymers to construct "tissues" for implantation. A tissue engineering approach has recently been used to construct living cardiac valve leaflets from autologous cells in our laboratory. This study assesses the feasibility of a tissue engineering approach to constructing tissue-engineered "living" pulmonary artery conduits.

MATERIALS AND METHODS

Ovine artery (group A, n = 4) or vein (group V, n = 3) segments were harvested, separated into individual cells, expanded in tissue culture, and seeded onto synthetic biodegradable (polyglactin/polyglycolic acid) tubular scaffolds (20 mm long x 15 mm diameter). After 7 days of in vitro culture, the autologous cell/polymer vascular constructs were used to replace a 2 cm segment of pulmonary artery in lambs (age 68.4 +/- 15.5 days, weight 18.7 +/- 2.0 kg). One other control animal received an acellular polymer tube sealed with fibrin glue without autologous cells. Animals were sacrificed at intervals of 11 to 24 weeks (mean follow-up 130.3 +/- 30.8 days, mean weight 38.9 +/- 13.0 kg) after echocardiographic and angiographic studies. Explanted tissue-engineered conduits were assayed for collagen (4-hydroxyproline) and calcium content, and a tissue deoxyribonucleic acid assay (bis-benzimide dye) was used to estimate number of cell nuclei as an index of tissue maturity.

RESULTS

The acellular control graft developed progressive obstruction and thrombosis. All seven tissue-engineered grafts were patent and demonstrated a nonaneurysmal increase in diameter (group A = 18.3 +/- 1.3 mm = 95.3% of native pulmonary artery; group V = 17.1 +/- 1.2 mm = 86.8% of native pulmonary artery). Histologically, none of the biodegradable polymer scaffold remained in any tissue-engineered graft by 11 weeks. Collagen content in tissue-engineered grafts was 73.9% +/- 8.0% of adjacent native pulmonary artery. Histologically, elastic fibers were present in the media layer of tissue-engineered vessel wall and endothelial specific factor VIII was identified on the luminal surface. Deoxyribonucleic acid assay showed a progressive decrease in numbers of cell nuclei over 11 and 24 weeks, suggesting an ongoing tissue remodeling. Calcium content of tissue-engineered grafts was elevated (group A = 7.95 +/- 5.09; group V = 13.2 +/- 5.48; native pulmonary artery = 1.2 +/- 0.8 mg/gm dry weight), but no macroscopic calcification was found.

CONCLUSIONS

Living vascular grafts engineered from autologous cells and biodegradable polymers functioned well in the pulmonary circulation as a pulmonary artery replacement. They demonstrated an increase in diameter suggesting growth and development of endothelial lining and extracellular matrix, including collagen and elastic fibers. This tissue-engineering approach may ultimately allow the development of viable autologous vascular grafts for clinical use.

Application of medical thermography to the diagnosis of Frey's syndrome

BACKGROUND

In Frey's syndrome, the secretory parasympathetic fibers of the parotid gland are thought to communicate with the sympathetic nerve fibers of sweat glands and blood vessels of the skin following parotidectomy. Miscommunication results in subjective gustatory sweating and facial flushing, which appear early with postoperative mastication. In this study, we compared the efficacy of medical thermography to the Minor's starch-iodine test to determine the presence of gustatory sweating in Frey's syndrome.

METHODS

Patients were considered to have Frey's syndrome if signs of gustatory sweating and localized skin flushing of the parotid region were present. In four patients who had undergone unilateral parotidectomy, gustatory sweating and facial flushing were present after gustatory stimulation, and the presence of Frey's syndrome was confirmed with Minor's starch test in all patients. Infrared thermography was then performed, and the same area measured. The contralateral side served as an internal control for each patient.

RESULTS

Before gustatory stimulation, the isothermal pattern of the diseased side and the nonoperative side was similar. Stress thermography using a sialogogue (lemon, 3 mL) showed a cold spot at the operative site in all four patients with Frey's syndrome. The contralateral nonoperative side showed normal skin temperature distribution in all patients. Minor's test was positive in all patients.

CONCLUSIONS

Thermography is a noninvasive, facile test that provides a qualitative visual analysis of the cutaneous capillary response in Frey's syndrome following parotid surgery.

Clinical outcome of digital replantation using the fibrin glue-assisted microvascular anastomosis technique

A series of 36 digital replants is reported in which microvascular anastomoses were each performed with four to six stitches and topically applied fibrin glue. Thirty-two digits survived, comparable to survival with conventional microvascular anastomosis. The average operative time per replanted digit was 3.2 hours, considerably less than documented with standard replantation technique (4.5 hours per digit). These clinical findings indicate that fibrin glue-assisted microvascular anastomosis does not compromise replant outcome and can reduce the operative time by reducing the number of microsutures that need to be placed in each anastomosis.

[Massive and progressive hepatosplenomegaly caused by disseminated nontuberculous mycobacteriosis in a patient with acquired immunodeficiency syndrome]

A 28-year-old hemophilia A patient was admitted to our hospital in July, 1991 because of high fever, chronic diarrhea and anemia. The patient had been recognized as a asymptomatic carrier of human immunodeficiency virus (HIV) in 1985 and had developed Pneumocystis carinii pneumonia and had been diagnosed as acquired immunodeficiency syndrome (AIDS) in 1990. Hematologic laboratory examinations on admission revealed pancytopenia and a CD4+ cell count of 3/mm3. X-ray findings of chest and abdomen were normal and bacterial cultures of sputum, urine, blood, stool, cerebrospinal fluid and bone marrow yielded no pathogenic microorganisms. Microscopical examination of the stained specimens showed no acid-fast bacilli. On his fifth hospital day, his liver and spleen enlarged markedly and an abdominal CT scan obtained on the 13th day revealed high-grade hepatosplenomegaly. Administration of several kinds of antibiotics, antifungal agents, antiviral agents, antituberculous agents and gamma-globulin medicines did not relieve the symptoms. On the 28th day the patient had developed a subarachnoid hemorrhage and died five days later. Retrospectively all cultures for acid-fast bacilli of the specimens on his admission yielded nontuberculous mycobacteria. The bacteria were identified as Mycobacterium avium by polymerase chain reaction and his disease was eventually diagnosed as disseminated Mycobacterium avium complex (MAC) infection. The liver and spleen weighed 2,660 g and 1,840 g respectively at autopsy. Although hepatosplenomegaly is commonly recognized in AIDS patients with disseminated MAC infection, such massive and rapid enlargement has been rarely observed. This case study emphasize the importance of diagnosis and rapid treatment at the early stage of MAC infection.

Patterns of thermoregulation associated with cold intolerance after digital replantation

Twelve patients with complete thumb amputations were analyzed to determine the interrelations between thermoregulation for pain and cold intolerance and sensory nerve recovery. Patients were examined at 3 months, 6 months, 1 year, and after 2 years following replantation. Medical thermography was introduced to assess postoperative circulation following digital replantation, while vasomotor tone was assessed by cold-stress plethysmography testing. Postoperative circulation was divided into two different patterns based upon skin temperature, the transition of which over time correlated well with sensory nerve recovery. Patients with cold intolerance showed a persistent vasoconstriction pattern, the cold change of which was objectively detected by thermography.

[Fluctuation of plasma levels of fibrinogen degradation products, fibrin degradation products and total fibrin/fibrinogen degradation products in patients with DIC]

Ten patients with disseminated intravascular coagulation syndrome (DIC) were analyzed using three enzyme linked immunosorbent assays (ORGANON TEKNIKA, Belgium) for fibrin degradation products (FbDP), fibrinogen degradation products (FgDP) and total fibrin/fibrinogen degradation products (TDP). A significant elevation in each parameter and a significant depression of FgDP/FbDP (g/b) ratio were observed in the patients in early stage of DIC, comparing with normal individuals (p < 0.001 and p < 0.01). These results suggested that both fibrinolysis and fibrinogenolysis were marked accelerated, with a superiority in fibrinolysis in those patients. The levels of these parameters decreased and the g/b ratio increased with the passage of the clinical courses in five patients who were improved. Although in five deteriorated cases, the levels were kept high and their g/b ratio showed low continuously. These findings suggested that separated monitoring of fibrinolysis or fibrinogenolysis was useful to study patients with DIC and g/b ratio could be regarded as a helpful indication of therapeutic effects.

Effect of hypertension on arterial structure and wound repair at the microvascular anastomosis site using stroke-prone spontaneously hypertensive rats (SHRSP)

Different processes of microvascular wound healing under hypertension in comparison to normotension have been suspected. To explore these differences at the site of anastomotic wound repair, we performed microvascular anastomoses of the femoral arteries in 12-week-old, stroke-prone hypertensive rats (SHRSP) whose maximum blood pressure reached 238 mm Hg and in normotensive age-matched Wistar Kyoto (WKY) rats. Morphologic changes under hypertension were examined via light microscopy. The arrangement and number of endothelial cells were examined using the en face silver staining technique. The plasma activity levels of factor XIII were also measured in each group. Transitional healing at the microvascular anastomosis site was evaluated via scanning electron microscopy. The extent of endothelial migration over the exposed media around the needle holes was determined using a computerized graphic analysis system. Histologic cross sections demonstrated a thickened media, with altered shape and arrangement of the smooth muscle cell nuclei in SHRSP arteries compared with WKY arteries. En face silver staining showed small and spindle-shaped endothelial cells with an irregular cell arrangement and distribution in SHRSP arteries relative to WKY arteries. Factor XIII was increased 36% over baseline in SHRSP rats postoperatively; this was significantly higher than the increase in WKY rats (P < 0.05). Although both SHRSP and WKY arteries had similar wound healing responses to microvascular anastomosis, endothelial cell migration over the exposed media was significantly accelerated in the SHRSP rats.

[Evaluation of novel assays for the detection of crosslinked fibrin degradation products in whole blood by the agglutination of the red blood cells]

We evaluated the clinical significance of two novel assays for the detection of crosslinked fibrin degradation products (XDP) in whole blood using the agglutination of the red blood cells (SimpliRED D dimer and SimpliRED D dimer-500, AGEN, Australia). XDP made serially by plasmin in vitro, were detected by the SimpliRED D dimer assay, but fibrinogen degradation products showed weak reactivity. Ten of the fifty four clinical samples collected with EDTA-2K, changed to positive on these assays after overnight incubation at 4 degrees C. Anemia and hemolytic samples had no effect on the assay results. The results obtained by the SimpliRED D dimer were negative for the normal subjects (n = 50) without exception. In our study, 81% and 95% of the patients, who showed abnormal levels of XDP in plasma and E fragments in serum respectively, were positive on the SimpliRED D dimer assay. The assay was as sensitive as the Rapidia-D dimer assay. In conclusion, the SimpliRED D dimer assay was clinically useful as a screening assay for the diagnosis of hypercoagulable and fibrinolytic states, since it could be performed simply and quickly.

Use of fibrin glue to minimize bleeding of microvascular repairs in hypertensive rats

The purpose of this study is to describe our technique of applying fibrin glue at the microvascular anastomotic site and to evaluate the effect of fibrin glue on anastomotic hemostasis and patency under various high pressure states using dopamine-induced acute hypertension in rats. A total of 72 male Wistar Kyoto rats, 10 weeks old, were used in this study. Under urethane anesthesia, end-to-end anastomosis of the left femoral artery was performed using 10-0 nylon suture by the standard interrupted suture technique. Pasteurized fibrin glue was then topically applied upon the suture line of the anastomosis. Thirty-six normotensive rats were divided into three groups based on the number of sutures (4, 6, or 8) used to complete the anastomosis. Groups were subdivided, half receiving fibrin glue application and half without. Thirty-six dopamine-induced acutely hypertensive rats were divided into three groups based on the blood pressure levels of 150, 200, and 250 mmHg, respectively. These groups were again subdivided, with half receiving glue applications. Microvascular anastomosis was performed using 6 nylon sutures. Patency rates and anastomotic bleeding were evaluated. The results revealed that successful anastomoses could be performed with fewer sutures when fibrin glue was used as a reinforcement at the anastomosis. Fibrin glue was also effective at the maximum blood pressure (250 mmHg) with no anastomotic leakage and no decrease in postoperative patency rate. These results suggest that conventional microsurgical suturing technique combined with fibrin glue would be effective in the prevention of leakage in microsurgical repairs, even under conditions of high blood pressure.

[Differentiation between fibrin degradation products and fibrinogen degradation products by using newly developed ELISAs]

We should distinguish fibrin degradation products (FbDP) from fibrinogen degradation products (FgDP) in order to analyze fibrinolysis in vivo. We analyzed some disorders associated with hyperfibrinolytic states using ELISA for FbDP, FgDP and total fibrin (ogen) degradation products (TDP) (ORGANON TEKNIKA). Each ELISA was useful in terms of reproducibility and dilution linearity of plasma samples. There was no cross-reaction between FbDP and FgDP. The FgDP/FbDP ratio in normal individuals was 1.65. In patients with DIC, it was 0.43, with FgDP level being increased. These results suggest that fibrinolysis is enhanced in patients with DIC, but it is accompanied by fibrinogenolysis. On the other hand, the FgDP/FbDP ratio in patients given urokinase (UK) was 2.88. This suggests that fibrinogenolysis is enhanced in them. In our study, the FgDP/FbDP ratio increased as DIC improved. Thus, we can regard this as an index of therapeutic effects in patients with DIC. We conclude that these three ELISA are useful in analyzing disorders associated with hyperfibrinolytic states.

The observation of endothelial cells in vein grafts by the en face silver staining method

The introduction of en face silver staining to microsurgery has provided useful, detailed information about endothelial cells with regard to their size, shape, and number. With this staining method, endothelial cells of rat vein grafts have been morphologically investigated following division of the site of observation into three areas: the recipient artery, the proximal part of the vein graft, and the midportion of the vein graft. The results show that the arterial endothelial cells are small and spindle-shaped, whereas the cells in the proximal vein graft location are larger. Finally, large, rounded endothelial cells are seen in the midportion of the graft. These results are quantitated through a computerized graphic analysis system, which provides estimations of the cell size, Feret's diameters, and irregularities in the cell borders. The combination of en face silver staining and computerized graphic analysis has been especially useful for comparing minute changes that occur in recovering/regenerating endothelial cells.

Wound healing at the site of microvascular anastomosis: fibrin-stabilizing factor XIII administration and its effects

Factor XIII has recently been recognized to play an important role as a fibrin-stabilizing factor to accelerate the wound healing process. We made an attempt to analyze the effect of how Factor XIII affects the results of the healing process at the site of a microvascular anastomosis. The strong fibrin stabilizing property of plasma Factor XIII maintained its high activity when administered intravenously and was effective for wound healing in a low-activity state made by subcutaneous administration of carbon tetrachloride. The enhanced network formation of the Factor-XIII-injected group was indicated by the accelerated maturation of the fibrin structure at the anastomotic site, exhibited both qualitatively and quantitatively. Stimulation and acceleration by Factor XIII of the healing process at the site of microvascular anastomosis were observed. It is therefore suggested that clinical use of Factor XIII may enhance the microvascular repair process. Details of the analysis using scanning electron microscopy (SEM) and a computerized graphic analyzer system (CGAS) are reported.

Re-endothelialization stages at the microvascular anastomosis

After microsurgical suturing, the wound healing process at the rat femoral artery anastomosis was studied with scanning electron microscopy. The re-endothelialization was divided into four successive stages, based on the development of a fibrin network and the rate of endothelial regrowth. Within 5 minutes of blood flow re-establishment the fibrin network formation started to cover the wound surface; it was completed by the 3rd or 4th day. The endothelial recovery started on the 2nd day and continued to the base of the suture by the 6th day. Re-endothelialization from the wound edge, which was formed between intact and injured endothelium toward the suture-restrained site, was a two-fold process: initially, a single endothelial film covered the anastomosis site, then, the singled endothelial sheet proliferated and thickened to complete the endothelialization. A better understanding of the stages involved in microvascular repair is beneficial in evaluating vascular recovery and its relationship to patency rates in microvascular surgery.