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Biomedical subjects

S Todo

Publications and source records attributed to S Todo.

At least 145 records · Page 8Linked to original sources

Effect of ischemia on the canine large bowel: a comparison with the small intestine.

Mucosal injury caused by ischemia and reperfusion has been well documented with the small intestine, but little is known about the colon. In the present study, the effect of warm and cold ischemia on the canine colon was studied and compared to that on the small intestine. After in situ flushing, the small intestine and the colon from six beagle dogs were removed and stored for 0.5, 1.5, and 3 hr at 37 degrees C (warm ischemia) or for 1, 6, 12, 24, 36, and 48 hr at 4 degrees C (cold ischemia). Electrophysiology, permeability, biochemistry, and histopathology of the specimens at each ischemic period and after reperfusion in the Ussing chamber were determined. Warm and cold ischemia induced duration-dependent suppression of electrophysiology in both organs, but the colonic mucosa retained higher activity of absorptive enterocytes and cryptic cells than the small intestine. Only the colon showed increased permeability of FITC-conjugated Dextran from the mucosal surface to the submucosal layer after prolonged ischemia. Changes in adenine nucleotides and purine catabolites were not markedly different between the organs. Histopathologic abnormalities during ischemia and after reperfusion were more serious with the small intestine than with the colon. Compared to warm ischemia, hypothermia lessened or delayed these morphofunctional derangements in both organs, which became universally worsened after reperfusion. Colonic mucosa receives morphofunctional derangements from ischemia and reperfusion, but the severity of the damage was much less severe in the colon than in the small intestine.

Adenosine Triphosphate↗

An automated and portable low-flow pulsatile perfusion system for organ preservation.

While machine preservation reduces the incidence of delayed graft function in renal transplant recipients, it is only used in 10% of kidney transplantations. The performance of our portable, low-flow-pulsatile organ perfusion system was examined in a canine kidney autotransplantation model. Grafts were stored for 72 h by simple cold preservation in University of Wisconsin (UW) solution, or by high or low-flow machine preservation After preservation, the grafts were autotransplanted and the animals were followed for 15 days. Graft function was better in machine-preserved kidneys. Tissue biochemistry indicated that machine preservation resulted in higher levels of adenine nucleotides and better histological integrity than the cold storage. While histology and biochemistry of machine-preserved groups were similar, electromicroscopy of high-flow grafts showed mild accumulation of intravenous debris and endothelial swelling. This study shows that a simplified machine perfusion technique is effective for organ preservation.

Animals↗

Psychiatric evaluations of small intestine transplantation patients.

We are gaining experience in small intestine transplantation, however, the procedure is still experimental. Morbidity and mortality can be significant with frequent rehospitalizations. The indications for small intestine transplantation are varied though most patients have developed short gut syndrome requiring total parenteral nutrition (TPN) for nutritional support. Patients may present with a chronic illness (such as Crohn's disease), chronic pain, and psychiatric comorbidity that may need to be addressed during the perioperative period. Faced with the complicated postoperative course, transplant recipients develop a range of endogenous and organic psychiatric disorders. Psychiatric treatment may be complicated by these factors in addition to the nutritional, biochemical, and metabolic abnormalities of a transplanted small intestine.

Adult↗

Clinical intestinal transplantation.

The advent of tacrolimus allowed clinical intestinal transplantation to become a feasible procedure for patients with irreversible intestinal failure. Over last 5 years, 71 patients underwent intestinal transplantation. Forty-one recipients were children, and 30 recipients were adults. Twenty-five patients received an isolated intestinal graft, 34 patients received a combined liver-intestinal graft, and 12 received a multivisceral graft. The colon was included the intestinal graft in 29 patients. One-year, 2-year, and 4-year actuarial patient survival is 72%, 57%, and 45%, respectively. Our experience has shown that infectious, and immunological problems have caused significant morbidity and mortality. In this paper, we present our clinical experience and overview with intestinal transplantation.

Journal Article↗

Hyper-interleukin (IL)-6-naemia in haemophagocytic lymphohistiocytosis.

Clinical features in patients with haemophagocytic lymphohistiocytosis (HLH) have been demonstrated to be characterized by hypercytokinaemia. Previously, we reported the impact of high serum levels of interferon (IFN)-gamma and soluble IL-2 receptor (sIL-2R) on patient outcome; however, it was not known if serum levels of interleukin (IL)-6 also could be a prognostic factor. In a study during the active phase of disease in 25 cases of HLH in children and young adults (median age 3 years, range 0.1-23 years), we noted 12 cases which showed serum IL-6 > 100 (normal < 4.0) pg/ml. Five of these cases showed hyper-IL-6-naemia alone without hyper-IFN-gamma-naemia (group A) whereas seven cases showed both hyper-IL-6- and IFN-gamma-naemia (group B). Patient outcome did not differ between the patients with IL-6 > 100 pg/ml and those with IL-6 < 100 pg/ml, suggesting that high serum concentrations of IL-6 alone do not necessarily indicate poor prognosis in patients with HLH. Among the cases with hyper-IL-6-naemia ( > 100 pg/ml), underlying disorders causing haemophagocytosis were found to be different between groups A and B.

Adolescent↗

Pathology of human intestinal transplantation.

BACKGROUND & AIMS: Intestinal transplantation is a developing therapeutic option for patients with irreversible intestinal failure or short bowel syndrome. The aim of this study was to delineate the histopathology of human intestinal allografts and to define the features of intestinal rejection. METHODS: The histological features of 3015 endoscopic biopsy specimens and 23 allograft specimens from 62 intestinal recipients were analyzed retrospectively and correlated with clinical findings. RESULTS: Acute allograft rejection was characterized by a varying combination of crypt injury, mucosal infiltration primarily by mononuclear cells (including blastic lymphocytes), and increased crypt cell apoptosis (more than 2 per 10 crypts). It represented a patchy, often ileal-centered process that could progress to mucosal ulceration; later episodes (more than 100 days posttransplant) tended to show lesser cellular infiltration and greater apoptosis than earlier episodes. Correlation with clinical rejection was good (false-positive rate of 9%; false-negative rate of 26%). Two resected specimens showed obliterative arteriopathy indicative of chronic rejection. In other specimens, preservation injury, cytomegalovirus infection, post-transplant lymphoproliferative disorder, and nonspecific features of active or past mucosal injury could be recognized. CONCLUSIONS: Mucosal biopsy specimens are a useful means of monitoring intestinal allografts. Based on features validated by clinical correlation, acute rejection can be identified reliably and can be differentiated from the other pathological processes affecting the intestinal allograft.

Acute Disease↗

Orthotopic liver transplantation in U.S. veterans under primary tacrolimus immunosupression.

The evolution and refinement of surgical techniques, per ioperative patient care, and immunosuppression hav~ estab~ished orthoto~ic li~er transplantation (OLTX) as a ~ighly successful therapeutic modality for patients wrth end-stage hver disease. In February 1989,Tacrohmus (Prograf®, formerly FK 506)was first used successfully at the University of Pittsburgh Medical Center to treat patients with rejection refractory to cyclosporine-based immunosuppression." Clinical trials utilizing Tacrolimus in solid organ transplantation followed, and in April of 1994 it was approved for use by the Food and Drug Administration,

Journal Article↗

The Pittsburgh randomized trial of tacrolimus compared to cyclosporine for hepatic transplantation.

BACKGROUND: Tacrolimus (formerly FK506) was first used clinically in 1989 to successfully replace cyclosporine in hepatic transplant recipients who were experiencing intractable rejection or as the baseline drug from the time of operation. After extensive pilot experience, an institutional review board-mandated clinical trial comparing cyclosporine with tacrolimus was performed. STUDY DESIGN: From February 16, 1990 to December 26, 1991, 154 patients were recruited. The competing drugs were combined with equal induction doses of prednisone in both arms of the study for the first 81 patients and with subsequently higher doses of prednisone in the remaining 35 patients who received cyclosporine and were entered into the trial. Drug crossover was permitted for lack of efficacy or adverse events. End points were rejection confirmed by biopsy and treatment failure leading to retransplantation or death. RESULTS: Seventy-nine patients were randomized to the tacrolimus arm and 75 to the cyclosporine arm during 1990 and 1991. All patients were available for follow-up throughout the trial, which terminated on May 30, 1995. The mean duration of follow-up was four years. Patients randomized to the tacrolimus arm were less likely to experience acute rejection than were those receiving cyclosporine, with 36.2 percent of the patients receiving tacrolimus and 16.8 percent of the patients receiving cyclosporine showing freedom from rejection at one year (p = 0.003, likelihood ratio test). Survival of patients over the course of the study was virtually the same in the two groups.

Adolescent↗

Liver allograft pathology in liver/small bowel or multivisceral recipients.

Combined liver/small bowel (LSB) and multivisceral (MV) transplantation represents an alternative treatment for patients with short-gut syndrome complicated by end-stage liver disease. However, the question of whether the addition of an intestinal allograft alters the pathologic features of the transplanted liver remains unanswered. We, therefore, evaluated the histologic features of 51 liver biopsy specimens from 13 LSB or MV recipients and compared them with a matched control group of specimens from recipients of isolated liver allografts. In general, the histologic alterations were comparable in the LSB/MV and control groups. The primary difference was that portal and sinusoidal neutrophilia accompanied acute cellular rejection in 10 (63%) of 16 LSB/MV specimens but none of the control specimens. Concurrent culture results were positive in 5 of the 10 cases: bacterial overgrowth of the intestinal allograft was found in 3 cases, and bacteremia in 2 other cases, 1 of which had also a positive liver culture. In contrast, these cultures (n = 7) were negative in the six LSB/MV cases of neutrophil-free acute cellular rejection. Neutrophilia was also present in 26 additional LSB/MV specimens, including instances of preservation injury, sepsis, impaired bile flow due to ampullary dysfunction, and one case without an underlying diagnosis, but its frequency did not significantly differ from that of corresponding control cases. An additional finding was the occurrence of a "fibrosing cholestatic" pattern of acquired hepatitis C in 10 specimens from 2 LSB/MV recipients. Acute cellular reaction-associated neutrophilia in LSB/MV recipients may reflect portal bacteremia resulting from bacterial overgrowth and translocation from the intestinal graft or represent simply a nonspecific hepatic response to intestinal inflammatory processes.

Adult↗

[Chemotherapy for B lymphoid malignancy in childhood--results in BLK88 protocol].

Ten cases of newly diagnosed pediatric B cell non-Hodgkin's lymphoma or acute lymphoblastic leukemia (B-NHL, stage I & II 6 cases, stage III & IV 2 cases/ALL 2 cases) experienced during the last 7 years (1987-1994) were treated by BLK88 protocol, which consisted of HD-CPM (1,200 mg/m2), and HD-MTX (1,000 mg/m2) with VCR, ADR, and/or AraC combination, and CNS prophylaxis by triple intrathecal injection. The therapy duration was 24 weeks for B-NHL (36 weeks for B-ALL). The results showed that while one of the six cases in stage I & II relapsed, and other 4 cases of stage III & IV B-NHL/ALL remained in complete remission. On the other hand, all of the four cases in stage III & IV in historical controls had relapsed. Neutropenia and liver dysfunction were observed during therapy, but they were tolerable. We conclude that BLK88 is a very useful protocol for B-NHL/ALL in childhood.

Adolescent↗