Characteristics of visual feedback in postural control during standing

In the present study, the visual feedback system in postural control was investigated. To suppress the vestibular and proprioceptive feedback paths, a subject stood on a force-measuring plate with a fixed back support. Because the subject's body was immovable under these conditions, the subject controlled a computer model which simulated body dynamics. Information on the sway angle of the model was fed visually. Under this condition, frequency response functions for the ankle moment in response to the sway angle were calculated. The experimental results suggest that the visual feedback system contains a large time delay and, consequently, the visual system does not by itself allow a subject to maintain an upright posture. Index Terms- Feedback control, frequency characteristics, identification, posture, visual sensory feedback.

Detection of a variety of Ser/Thr protein kinases using a synthetic peptide with multiple phosphorylation sites

A novel peptide with multiple phosphorylation sites, which we designated as multide, was developed to detect a wide variety of protein kinases in crude cell extracts. Multide, KKRKSSLRRWSPLTPRQMSFDC, has been designed to contain consensus sequences for various Ser/Thr protein kinases including cAMP-dependent protein kinase, protein kinase C, MAP kinases, and Ca(2+)/calmodulin-dependent protein kinases in a single peptide. In-gel protein kinase assay using multide was found to be very useful for analyzing the activities of protein kinases that are altered in response to various extracellular stimuli. The substrate specificities of the protein kinases thus detected were further determined by using five multide analogs with different phosphorylation sites.

Tumor suppressor p53 but not cGMP mediates NO-induced expression of p21(Waf1/Cip1/Sdi1) in vascular smooth muscle cells

Cyclin-dependent kinase inhibitor p21(Waf1/Cip1/Sdi1) has been suggested to be involved in the antiproliferative effect of nitric oxide (NO) in vascular smooth muscle cells (VSMCs). To elucidate the mechanism underlying NO-induced p21 expression, we investigated the roles of tumor suppressor p53 and the guanylate cyclase-cGMP pathway. The induction of p21 by the NO donor S-nitroso-N-acetylpenicillamine (SNAP) seemed to be due to transactivation because SNAP elevated the activity of p21 promoter but did not stabilize p21 mRNA and protein. Because SNAP did not stimulate the deletion mutant of p21 promoter that lacked p53 binding sites, we tested the involvement of p53. The expression level of p53 was down-regulated after mitogenic stimulation, whereas it was sustained in the presence of SNAP. SNAP markedly stimulated DNA binding activity of p53. Furthermore, SNAP failed to induce p21 in VSMCs obtained from p53-knock out mice and in A431 cells that contained mutated p53. The antiproliferative effect of SNAP also was attenuated in these cells. NO stimulates guanylate cyclase and its product cGMP has been shown to inhibit VSMC proliferation. However, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, a guanylate cyclase inhibitor, did not prevent SNAP-induced p21 expression. 8-Bromo-cGMP, 3-isobutyl-1-methylxanthine, and their combination did not induce p21. Although 8-bromo-cGMP had a small antiproliferative effect, the elevation of cGMP concentration induced by SNAP was little throughout the G(1) phase. The antiproliferative effect of SNAP was not attenuated by Rp-8-bromoguanosine-3',5'-monophosphorothioate, an inhibitor of cGMP-dependent protein kinase. These results suggested that NO induces p21 through a p53-dependent but cGMP-independent pathway.

Striatal perfusion of indomethacin attenuates dopamine increase in immature rat brain exposed to anoxia: an in vivo microdialysis study

Using in vivo microdialysis and HPLC, we examined the effects of indomethacin on extracellular dopamine (DA) in the striatum of immature rats submitted to anoxia. Rat pups in two indomethacin groups received intrastriatal perfusion of either 1 mM or 5 mM indomethacin throughout the experiment. The DA level reached 1185+/-400% of the basal level during anoxia; in contrast, the peak levels of DA were only 307+/-63%, 153+/-35% in indomethacin groups (p<0.05). We consider that this suppression would be one of the mechanisms of the protective effect of indomethacin on hypoxic ischemic encephalopathy.

Juxtaglomerular cell tumor with retroperitoneal fibrosis and secondary immune-complex glomerulonephritis: a possible contribution of the renin angiotensin system to renal fibrosis

We present a case of a 25-year-old woman with a renin-secreting juxtaglomerular cell tumor, retroperitoneal fibrosis associated with glomerular hypertrophy, glomerulonephritis, and marked tubulointerstitial alterations. Myofibroblasts, as shown by positive immunostaining for alpha-smooth muscle actin, were found along with transforming growth factor-beta (TGF-beta) in the interstitium of the tumor-free kidney. Regarding the pathogenesis of renal fibrosis and glomerular hypertrophy, this case may provide evidence not only experimentally but also clinically that the renin-angiotensin system plays an important role because angiotensin II is known to induce renal fibrosis associated with increased TGF-beta and the appearance of myofibroblasts.

Phosphorylation and activation of Ca2+/calmodulin-dependent protein kinase phosphatase by Ca2+/calmodulin-dependent protein kinase II

Ca2+/calmodulin-dependent protein kinase phosphatase (CaMKPase) is a protein phosphatase which dephosphorylates autophosphorylated Ca2+/calmodulin-dependent protein kinase II (CaMKII) and deactivates the enzyme (Ishida, A., Kameshita, I. and Fujisawa, H. (1998) J. Biol. Chem. 273, 1904-1910). In this study, a phosphorylation-dephosphorylation relationship between CaMKII and CaMKPase was examined. CaMKPase was not significantly phosphorylated by CaMKII under the standard phosphorylation conditions but was phosphorylated in the presence of poly-L-lysine, which is a potent activator of CaMKPase. The maximal extent of the phosphorylation was about 1 mol of phosphate per mol of the enzyme and the phosphorylation resulted in an about 2-fold increase in the enzyme activity. Thus, the activity of CaMKPase appears to be regulated through phosphorylation by its target enzyme, CaMKII.

Accelerated healing of Dacron grafts seeded by preclotting with autologous bone marrow blood

> Studies have suggested that bone marrow-derived cells in the circulation may have the capacity and potential to endothelialize and heal vascular graft surfaces. We have investigated whether accelerated endothelialization could be achieved for Dacron grafts seeded by preclotting with bone marrow blood (BMB). Five 8 mm x 6 cm Dacron grafts seeded and preclotted with BMB and four controls preclotted with peripheral blood were implanted in the descending thoracic aorta (DTA) of mongrel dogs for 2 and 4 weeks. Two additional BMB DTA grafts were studied for 3 months. Five pairs of BMB and control grafts (4 mm x 6 cm) were bilaterally implanted into the carotids of dogs for 1 week and five pairs for 4 weeks. All grafts remained patent. BMB seeding/preclotting was a simple, effective method to accelerate early graft endothelialization without increasing thrombogenicity. Further studies are needed before clinical application can be recommended.

Stable gene expression with VSV-G pseudotyped-retrovirus vector in the rat liver

BACKGROUND

Pseudotyped-retrovirus-mediated gene transfer to the regenerating rat liver was investigated in vivo and the findings were compared with those for retrovirus-mediated gene transfer.

MATERIALS AND METHODS

Four weeks prior to gene transfer, the spleen was transpositioned to the left subcutaneous position to develop a port-splenic shunt. Twenty-four hours after a partial hepatectomy (68%) was performed, the liver was perfused in situ and kept in contact with either a pseudotyped-retrovirus vector encoding LacZ (7 x 10(7) cfu/ml, Group 1) or a retrovirus vector encoding LacZ (1 x 10(4) cfu/ml, Group 2) for 30 min. The animals were sacrificed at various points after gene transfer, and X-gal staining, reversed polymerase chain reaction (RT-PCR), and ONPG assay were performed to detect the transferred LacZ cDNA.

RESULTS

In X-gal staining, the transferred LacZ cDNA started to show a strong beta-galactosidase activity in 30 to 50% of the hepatocytes at 3 days after gene transfer. Positive staining continued to be recognized until 28 days with a slight decrease in its intensity thereafter. On the other hand, Group 2 animals showed weak staining, which was observed in about 10 to 15% of the hepatocytes from 3 days after gene transfer and then decreased thereafter. In RT-PCR, positive mRNA of LacZ was detected constitutively until 28 days after gene transfer in Group 1, whereas two-thirds of the samples showed a negative band in Groups 2 at 3 days after gene transfer.

CONCLUSION

In conclusion, the pseudotyped-retrovirus vector was useful in establishing a stable and strong expression of the in vivo gene transfer, while targeting the regenerating liver.

A simple radiographic measurement method for polyethylene wear in total knee arthroplasty

This study describes a new method for evaluating polyethylene wear in total knee arthroplasty. Since the amount of wear is dependent on a number of variables such as the weight and activity of the patient, it should be estimated based on in vivo measurements. We used a computer vision technique called three-dimensional/two-dimensional (3-D/2-D) matching to perform in vivo assessment using a single-plane radiograph. Using the 3-D/2-D matching algorithm we estimated the 3-D position and orientation of each knee implant and then measured the femorotibial distance, which is defined as the shortest perpendicular distance from the tibial tray to the femoral component. The accuracy of the proposed 3-D/2-D matching method was determined by in vitro investigations. The worst errors in in-plane/out-of-plane translations and rotations were 0.20/1.95 mm and 0.17/0.29 degrees, respectively. The root-mean-square error in femorotibial distance measurements using real polyethylene inserts was 0.04 mm. Results of in vivo femorotibial distance measurements are also described.

Regulation of growth hormone-releasing hormone receptor messenger ribonucleic acid expression by glucocorticoids in MtT-S cells and in the pituitary gland of fetal rats

Regulation of GH-releasing hormone receptor (GHRH-R) messenger RNA (mRNA) expression was studied, with the ribonuclease protection assay, in the fetal rat pituitary gland and in MtT-S clonal cells. GHRH-R mRNA was first detected on embryonic day (E)19 and increased rapidly thereafter, to reach a maximum at E21. Incubation of E17 or E18 pituitaries with 50 nM dexamethasone (DEX), a synthetic glucocorticoid, induced GHRH-R mRNA expression, suggesting that glucocorticoids play a pivotal role in the developmental expression of this mRNA. In E19 pituitaries, 24 h treatment with DEX increased GHRH-R mRNA by 60%, and GH mRNA by 76%, but did not affect pit-1 mRNA level, suggesting that the effect of DEX is specific for expressions of GH mRNA and GHRH-R mRNA. The accumulation of GHRH-R mRNA by DEX was time dependent, and it was slightly enhanced by the protein synthesis inhibitor, puromycin (100 microM). In MtT-S cells (a pituitary cell line established from an estrogen-induced tumor), DEX induced GHRH-R mRNA expression within 2 h in a dose-dependent manner. This induction was augmented by puromycin (100 microM) or cycloheximide (3.5 microM). However, the RNA synthesis inhibitor Actinomycin D (1 microM) completely inhibited GHRH-R mRNA accumulation in response to either DEX or DEX plus puromycin, suggesting that glucocorticoids induce GHRH-R mRNA mainly through stimulation of mRNA transcription. These results suggest: that GHRH-R mRNA accumulation in the fetal pituitary gland of rats normally occurs at E19, probably because of the direct action of glucocorticoids on the pituitary gland, to stimulate GHRH-R mRNA transcription; and that the expression of glucocorticoid receptors is an important event in GH cell development in rats. Accordingly, immunocytochemical results suggest an increase in glucocorticoid receptors in immature GH cells between E17 and E18. The present results also imply that MtT-S cells may be a good model in which to further study the molecular mechanisms of the regulation of GHRH-R gene expression.

Molecular cloning of Ca2+/calmodulin-dependent protein kinase phosphatase

Calmodulin-dependent protein kinase (CaM-kinase) phosphatase dephosphorylates and concomitantly deactivates CaM-kinase II activated upon autophosphorylation, and CaM-kinases IV and I activated upon phosphorylation by CaM-kinase kinase [Ishida, I., Okuno, S., Kitani, T., Kameshita, I., and Fujisawa, H. (1998) Biochem. Biophys. Res. Commun. 253, 159-163], suggesting that CaM-kinase phosphatase plays important roles in the function of Ca2+ in the cell, because the three multifunctional CaM-kinases (CaM-kinases I, II, and IV) are thought to be the key enzymes in the Ca2+-signaling system. In the present study, cDNA for CaM-kinase phosphatase was cloned from a rat brain cDNA library. The coded protein consisted of 450 amino acids with a molecular weight of 49, 165. Western blot analysis showed the ubiquitous tissue distribution of CaM-kinase phosphatase. Immunocytochemical analysis revealed that CaM-kinase phosphatase is evenly distributed outside the nucleus in a cell.

Synthesis of caged peptides using caged lysine: application to the synthesis of caged AIP, a highly specific inhibitor of calmodulin-dependent protein kinase II

N(alpha)-Fmoc-N(epsilon)-(2-nitrobenzyloxycarbonyl)-lysine has been prepared and used in the solid-phase synthesis of caged peptides. The synthesized caged AIP (cagedKcagedKALRRQEAVDAL) showed characteristics required for caged peptides including a significantly reduced inhibitory activity to calmodulin-dependent protein kinase II and instantaneous recovery of the activity with photo-irradiation.

Immunohistochemical study on transforming growth factor-beta1 expression in liver fibrosis of Down's syndrome with transient abnormal myelopoiesis

A case of Down's syndrome associated with liver fibrosis is reported. The fibrosis was diffusely distributed along sinusoids, and an excess of megakaryocytes was also found in the liver. To determine the mechanism of liver fibrosis in Down's syndrome, we immunohistochemically stained the liver with markers of myofibroblast-like cells, antialpha smooth muscle actin antibodies and antidesmin antibodies. The myofibroblast-like cells were found along sinusoids, suggesting that liver fibrosis in Down's syndrome is caused by the myofibroblast-like cells derived from Ito cells/lipocytes. The expression of transforming growth factor (TGF)-betal, which is an important mediator of the activation of lipocytes, was immunohistochemically examined. The accumulation of TGF-betal was observed in cells in the sinusoidal spaces, which involve the intracellular expression of megakaryocytes. Together, these findings suggest that megakaryocyte-derived TGF-betal is one of the likely candidates in the lipocyte activation of liver fibrogenesis in Down's syndrome.

Clinical significance of the F wave area in diabetic polyneuropathy

OBJECTIVE

To investigate the electrophysiological significance of the abnormal F wave are (Farea) and its ratio (F/Marea) (%) to the corresponding M wave area (Marea) in patients with diabetic polyneuropathy (DP).

MATERIALS AND METHODS

For tibial and peroneal nerves, the F/Marea and other F wave parameters (duration [Fdur], minimum latency [Fmin], amplitude [Famp]) were compared in 34 patients and age-matched controls.

RESULTS

For controls, the Farea correlated with the Marea, but this was not found for DP patients. The peroneal F/Marea for DP patients was significantly larger than that for controls. For the both nerves, however, the F/Marea for DP patients was larger in nerves with a decreased Marea than those in nerves with a normal Marea and in the controls. An increased F/Marea was accompanied by prolonged Fdur. A decreased F/Marea was uncommon. The incidence of abnormal F/Marea was somewhat larger than that of abnormal F/Mamp, but smaller than the values for MCV and Fmin.

CONCLUSIONS

The relationship between Farea and the Marea for DP patients differed from that of controls. An increased F/Marea was considered to reflect a denervation-reinnervation process or some central modification in firing of the anterior horn cells. Whereas amplitude of the F wave also reflect these electrophysiological conditions, the F/Marea is a little more sensitive than F/Mamp in detecting the abnormality.

Treatment of advanced myelodysplastic syndrome with a regimen including recombinant human granulocyte colony-stimulating factor preceding allogeneic bone marrow transplantation

We treated 13 patients with morphologically advanced myelodysplastic syndrome using cytosine arabinoside and total body irradiation, followed by allogeneic marrow transplantation from HLA-identical sibling donors. Granulocyte colony-stimulating factor (G-CSF) was added to the preparative regimen to selectively increase chemosensitivity of leukaemic cells and to improve transplant outcome. No regimen-related deaths occurred, and no side-effects related to the addition of G-CSF were observed except for transient mild bone pain. At a median follow-up time of 39 months the projected 5-year disease-free survival and 5-year overall survival were 67.7% and 75.5%, respectively, with only one case showing cytogenetic relapse. The preparative regimen including G-CSF is feasible, and preliminary results seem to be encouraging. However, a larger trial is clearly warranted to evaluate its efficacy.

Prospective evaluation for upper gastrointestinal tract acute graft-versus-host disease after hematopoietic stem cell transplantation

The incidence and clinical significance of upper gastrointestinal tract acute graft-versus-host disease (upper GI GVHD) were prospectively evaluated in 44 Japanese patients who underwent allogeneic (n = 26) or autologous (n = 18) stem cell transplantation. Endoscopic examination was routinely performed between days 20 and 50 post-transplant and when symptoms of upper GI and/or acute GVHD of other organs were present. The results were compared with the historical records of 49 allograft and 20 autograft recipients. The diagnosis of upper GI GVHD was confirmed by histologic findings of GVHD and persistent upper GI tract symptoms. The incidence of upper GI GVHD was 46% in the prospective allograft group, higher than in the retrospective group. Upper GI GVHD was not diagnosed in any autograft patients. Twelve of 19 patients with upper GI GVHD had skin GVHD, and two of the 12 had concurrent lower GI GVHD. Upper GI GVHD was successfully treated with steroids and did not progress to symptomatic lower GI GVHD. In addition, upper GI GVHD completely resolved without specific alteration in immunosuppressant therapy in six patients. No risk factors for upper GI GVHD could be identified. The presence of upper GI GVHD did not significantly affect early death rate, incidence of chronic GVHD, and overall survival. In conclusion, by the prospective evaluation of the upper GI tract by endoscopy we could accurately diagnose upper GI GVHD in half our allogeneic recipients. However, upper GI GVHD was successfully controlled with or without additional steroids in all cases and had little impact on transplant outcome.

[Proliferation inhibition of glioma cells by vitamin K2]

The antitumor effects of vitamin K2 were studied using three glioma cell lines: C6 (rat glioma cell), RBR17T and T98G (human glioma cell). The antitumor effects were estimated by count assay. The results was that vitamin K2 induced growth inhibition in a dose-dependent manner. The RBR 17T cells exposed to vitamin K2 for 72 hours resulted in oligonucleosomal DNA fragmentation and formed a ladder on agarose gel electrophoresis. Furthermore, the RBR17T cells exposed to vitamin K2 for 24 hours were significantly accumulated in the G0G1 phase of the cell cycle. Those results suggested that vitamin K2 can inhibit the proliferation of cells through the induction of cell cycle arrest and apoptosis for tumor cells. The combined treatment of vitamin K2 with ACNU or 5-FU or INF-beta or 1,25-dihydroxyvitamin D3 enhanced growth inhibition significantly. In conclusion, vitamin K2 can be a useful drug for the treatment of glioma.

3-Methylglutaconic aciduria type I: clinical heterogeneity as a neurometabolic disease

3-Methylglutaconic (3-MGC) aciduria with 3-methylglutaconyl-CoA hydratase deficiency (3-MGC aciduria type I) is a rare inherited metabolic disease of L-leucine catabolism. We describe a 9-month-old Japanese boy with this disorder who showed progressive neurological impairments presented as quadriplegia, athetoid movements and severe psychomotor retardation from 4 months of age. This finding indicates the existence of clinical heterogeneity in 3-MGC aciduria type I, suggesting it may present as a neurometabolic disease.

Angiotensin II receptor blockade limits kidney injury in two-kidney, one-clip Goldblatt hypertensive rats with special reference to phenotypic changes

Recent evidence indicates that tubulointerstitial injury plays an important role in hypertensive kidney injury and that phenotypic changes contribute to this pathology. Moreover, angiotensin II is known to be actively involved in the pathogenesis of progressive kidney injury induced by hypertension. The present study was undertaken to see the effect of a newly developed angiotensin II type I receptor (AT1 receptor) antagonist on hypertension-induced kidney injury and to determine the contribution of phenotypic changes to morphologic alterations. Two-kidney, one-clip (2K1C), Goldblatt hypertensive rats (n = 27) were made by clipping the left renal artery. These animals were orally administered 57G709 (a selective non-peptide AT1 receptor antagonist)(10 mg/kg/day), captopril (20 mg/kg/day), or vehicle alone for 23 days beginning 4 weeks after clipping. In the non-clipped kidney of vehicle-treated 2K1 C rats, marked tubulointerstitial injury as well as glomerular sclerosis and/or hyalinosis was found in association with phenotypic changes, as shown by the neoexpression of vimentin in periglomeruli, perivascular walls, distal tubuli, and injured interstitium. Renin expression was markedly suppressed in the non-clipped kidneys of vehicle-treated 2K1C rats as compared with renin expression in normotensive control kidneys of sham-operated rats. Both 57G709 and captopril markedly ameliorated hypertensive kidney injury as reflected by the glomerular sclerosing index and by the tubulointerstitial index as determined by the point-counting method, and this improvement was accompanied by a significant decrease in blood pressure, urinary protein excretion, kidney/body weight ratio, and heart/body weight ratio. In addition, the vimentin neoexpression mentioned above was also suppressed with an inhibition of angiotensin II. These results suggest that in 2K1C Goldblatt hypertensive kidney injury, the AT1 receptor antagonist 57G709 exerts a potent renal protective effect associated with the inhibition of phenotypic changes.

Anoxic and hypoxic immature rat model for measurement of monoamine using in vivo microdialysis

The immature brain is considered relatively resistant to anoxia and ischemia. Although hypoxia without ischemia has not been considered to produce brain damage in immature rats as well as in adult rats (S. Levine, Anoxic-ischemic encephalopathy in rats, Am. J. Pathol., 36 (1960) 1-17 [8]; D.E. Levy, J.B. Brieley, D.G. Silverman, F. Plum, Brief hypoxia-ischemia initially damages cerebral neurons, Arch. Neurol., 32 (1975) 450-456 [9]; J.E. Rice, R.C. Vannucci, J.B., Brieriey, The influence of immaturity on hypoxic-ischemic brain damage in rat, Ann. Neurol., 9 (1981) 131-141 [14]), hypoxia in postnatal period is possible to cause a functional brain damage (T. Hender, P. Lundborg, Regional changes in monoamine synthesis in the developing rat brain during hypoxia, Acta. Physiol. Scand., 106 (1979) 139-143 [3]; W. Ihle, J. Gross, R. Moller, Effect on chronic postnatal hypoxia on dopamine uptake by synaptosomes from striatum of adult rats, Biomed. Biochem. Acta., 44 (1985) 433-437 [7]; A. Lun, J. Gross, M. Beyer, H.D. Fischer, C. Wustmann, J. Schmidt, K. Hecht, The vulnerable period of perinatal hypoxia with regard to dopamine release and behavior in adult rats, Biomed. Biochem. Acta., 45 (1986) 619-627 [10]). Using microdialysis, we studied the anoxic or hypoxic effect on catecholamine metabolism in immature rat brain by measuring extracellular concentrations of norepinephrine (NE), dopamine (DA), and its metabolites and also 5-hydroxyindole-3-acetic acid (5-HIAA), the serotonin metabolite. DA is a well established excitatory neurotransmitter (R.C. Vannucci, Experimental biology of cerebral hypoxia-ischemia: relation to perinatal brain damage, Pediatr. Res., 27 (1990) 317-326 [16]), and in the previous report using hypoxic 7-day-old rat pups increase of DA was not detected without additional stimulations (K. Gordon, D. Johnston, M.V. Robinson, T.E. Statman, J.B. Becker, F. Silverstein, Transient hypoxia alters striatal catecholamine metabolism in immature brain: An in vivo microdialysis study, J. Neurochem., 54 (1990) 605-611 [2]). Whereas recently in newborn piglets, hypoxic hypoxia produced increase of extracellular DA (C.-C. Huang, N.S. Lajevardi, O. Tammela, A. Pastuszko, Relationship of extracellular dopamine in striatum of newborn piglets to cortical oxygen pressure, Neurochem. Res., 19 (1994) 649-655 [6]; Olano, M., Song, D., Murphy, S., Wilson, D. F. and Pastuszko, A., Relationships of dopamine, cortical oxygen pressure, and hydroxyl radicals in brain of newborn piglets during hypoxia and posthypoxic recovery, J. Neurochem., 65 (1995) 1205-1212 [13]). We consider that hypoxic ischemic brain damage of human newborns that we can treat is a damage, which does not show overt neuropathological changes. We therefore tried to show that transient anoxia and hypoxia caused biochemical alteration if the exposure did not produce marked morphological changes. This rodent model is adequate to study perinatal asphyxia and alteration of monoamine level could be useful for evaluation of brain damage, even if it is not detected histologically.

Genetic tracing of arterial graft flow surface endothelialization in allogeneic marrow transplanted dogs

In order to trace genetically the source of fallout endothelialization on arterial grafts, six beagle dogs with successful autologous bone marrow transplantation received composite tandem aortic grafts with an isolated, totally impervious Dacron graft and a porous Dacron graft for 12 weeks. For impervious segments, five of 12 fresh tissue samples were Factor VIII/von Willebrand factor + (FVIII/vWF) and seven had faint or negative signals; three of the FVIII/vWF + samples had alpha-actin + smooth muscle cells. Polymerase chain reaction (PCR) study showed eight had a pure donor DNA genotype and four had donor/host mixed, with the donor predominant. Of 12 AgNO3-stained samples, 11 showed pure donor type and one had donor/host mixed, with the donor predominant. For porous segments, all 12 fresh samples had positive flow surface FVIII/vWF and alpha-actin cells. PCR showed all these samples and all 12 AgNO3-stained samples had donor/host mixed type, but the host pattern was predominant. Porous graft healing appears to involve both cellular fallout and tissue ingrowth, and bone-marrow-derived cells may be a source for fallout.