The acoustic radiation force impulse elastography evaluation of liver fibrosis in posttransplantation dysfunction of living donor liver transplantation

BACKGROUND

The acoustic radiation force impulse elastography (ARFI) is a new technology of elastography integrated into B-mode ultrasonography. It has been a reliable method to evaluate liver fibrosis of chronic liver disease in recent years, but less applied in the posttransplantation liver. The aim of the study was to evaluate liver fibrosis by the ARFI with correlation of pathological stages in living donor liver transplantation (LDLT).

MATERIALS AND METHODS

From August 2010 to August 2012, there were 57 LDLT patients with liver biopsy (LB) due to posttransplantation dysfunction; all patients also received posttransplantation ARFI liver stiffness measurement (LSM) after transplantation for liver fibrosis staging. The ARFI elastography was performed using a Siemens Acuson S2000 ultrasound system with 4V1 transducers (Acusion, Siemens Medical Systems Co. Ltd. Erlangen, Germany). The ARFI LSM value was presented by shear wave velocity (SWV, m/s). The fibrosis staging as F0 to F4 was in accordance with the Metavir scoring system.

RESULTS

A total of 57 patients had both posttransplantation LB and effective ARFI fibrosis staging for correlation. The ARFI LSM value increased with severity of liver fibrosis and had significant linear correlation with the results of histological fibrosis staging. The ARFI LSM sensitivities (Se), specificities (Sp), and cutoff values based on receiver-operator characteristic curve were F0: 0.75 m/s (Se: 93.8%, Sp: 4%), F1: 1.06 m/s (Se: 95.5%, Sp: 25.7%), F2: 1.81 m/s (Se: 50%, Sp: 83.6%) and F3: 2.33 m/s (Se: 100%, Sp: 92.9%). Predictive value of ARFI LSM reported a significant difference between early fibrosis stage (F0-F1) and advanced fibrosis stage (F ≧ 2) (P < .05).

CONCLUSION

In this study, ARFI demonstrated a strong linear correlation and severity of liver fibrosis with LB pathologic staging. ARFI can be an alternative and compensatory method for frequent LB in the posttransplantation liver.

Liver graft-to-recipient spleen size ratio as a novel predictor of portal hyperperfusion syndrome in living donor liver transplantation

Portal hyperperfusion in a small-size liver graft is one cause of posttransplant graft dysfunction. We retrospectively analyzed the potential risk factors predicting the development of portal hyperperfusion in 43 adult living donor liver transplantation recipients. The following were evaluated: age, body weight, native liver disease, spleen size, graft size, graft-to-recipient weight ratio (GRWR), total portal flow, recipient portal venous flow per 100 g graft weight (RPVF), graft-to-recipient spleen size ratio (GRSSR) and portosystemic shunting. Spleen size was directly proportional to the total portal flow (p = 0.001) and RPVF (p = 0.014). Graft hyperperfusion (RPVF flow > 250 mL/min/100 g graft) was seen in eight recipients. If the GRSSR was < 0.6, 5 of 11 cases were found to have graft hyperperfusion (p = 0.017). The presence of portosystemic shunting was significant in decreasing excessive RPVF (p = 0.059). A decrease in portal flow in the hyperperfused grafts was achieved by intraoperative splenic artery ligation or splenectomy. Spleen size is a major factor contributing to portal flow after transplant. The GRSSR is associated with posttransplant graft hyperperfusion at a ratio of < 0.6.

Successful microsurgical tissue transfer in a patient with postsplenectomy thrombocytosis treated with platelet-phoresis

With the use of platelet-phoresis, two microsurgical free-tissue transfers were successfully undertaken in a patient with postsplenectomy thrombocytosis that had initially caused flap failure. Rapid reduction in the platelet count allowed free-tissue transfer in this patient who required early wound coverage.

Going deep into chemical burns

This is a five year retrospective study of chemical burn injury in our burn center between 1 January 1987 and 31 December 1991. Of the 1,226 total burn cases, 131 patients had chemical burns. We noted a constant prevailing incidence of 10.7% per year. Males (72%) are more common than females (28%). Most of those injured are in the working age group (65%). Majority of cases had deep full thickness burn involving less than 10% of their total body surface area. Sulfuric acid is the most common chemical agent encountered. We had three mortality cases with deep third degree burns covering 60% of their total body surface area. Some clinical cases are demonstrated. Lastly, proposed solutions for the prevention of chemical burns are cited.

Combined surgery and irradiation for treatment of hypertrophic scars and keloids

This is a study of 11 patients who received combined surgery and irradiation for intractable hypertrophic scars and keloids. All of the patients received early post-operative (within 24 hours) irradiation with a 6-MeV electron beam and a total dose ranging from 1500-2100 rads in five to nine fractions after surgical excision of the lesions. The subjects were followed-up for over six months and the results are as follows: seven had a good response; three had a partial response; and one experienced a recurrence. The overall response rate was 90%, and no radiation injuries to the skin or delayed healing of the wound were noted. These preliminary outcomes are encouraging, especially for those patients who can not tolerate or have not responded well to other treatment programs.

Possible role of nicotinamide adenine dinucleotide as an intracellular regulator of renal transport of phosphate in the rat

In these experiments we investigated whether NAD could serve as an intracellular modulator of the brush border membrane (BBM) transport of inorganic phosphate (Pi). NAD, both oxidized (NAD+) and reduced (NADH) form, inhibited the Na+-dependent uptake of 32Pi in the concentration range of 10-300 microM NAD when added in vitro to BBM vesicles isolated from rat kidney cortex, but did not inhibit BBM uptake of D-[3H]glucose or BBM uptake of 22Na+. Neither nicotinamide (NiAm) nor adenosine alone influenced BBM uptake of 32Pi. NAD had a similar relative effect (percent inhibition) in BBM from rats stabilized on low Pi diet (0.07% Pi), high Pi diet (1.2% Pi), or normal Pi diet (0.7% Pi). Subsequently, we examined the renal effects of changing the tissue NAD level in vivo. Rats stabilized on low Pi diet were injected intraperitoneally with NiAm (0.25-1.0 g/kg body wt); urinary excretions of Pi (UPiV), of fluid, and of other solutes were measured before and after NiAm injection, then renal cortical tissue nucleotide content was determined, and a BBM fraction was isolated for transport measurements. In BBM from NiAm-treated rats, the Na+-dependent uptake of 32Pi was decreased, but BBM uptake of D-[3H]glucose and BBM uptake of 22Na+ were not changed. NiAm injection elicited an increase in NAD+ (maximum change, 290%), a lesser increase in NADH (maximum change, +45%), but no change in the content of ATP or cyclic AMP in the renal cortex. Na+-dependent BBM uptake of 32Pi ws inversely correlated with NAD+ content in renal cortex (r = -0.77 +/- 0.1; P less than 0.001) and with UPiV (r = -0.67 +/- 0.13; P less than 0.01). NAD+ in renal cortex was positively correlated with UPiV (r = 0.88 +/- 0.05; P less than 0.001). Injection of NiAm elicited a marked increase in UPiV, but no change in excretions of creatinine or K+, or in urine flow; excretion of Na+ and Ca declined. NiAm injection caused similar renal responses, in normal and in thyroparathyroidectomized rats, as well as in rats on normal Pi diet and low Pi diet. We conclude that NAD can serve as an intracellular modulator (inhibitor) of Na+-dependent transport of Pi across the renal luminal BBM and across the proximal tubular wall by its direct interaction with BBM. We propose that at least some hormonal and/or metabolic stimuli elicit phosphaturia by increasing NAD+ in cytoplasm of proximal tubular cells.

Antimutagenic effects of 2(3)-tert-butyl-4-hydroxyanisole and of antimicrobial agents

Administration of the antioxidants 2(3)-tert-butyl-4-hydroxyanisole (BHA) and ethoxyquin (1,2-dihydro-6-ethoxy-2,2,4-trimethylquinoline) with the diet resulted in a marked decrease in the levels of mutagens present in mice treated with benzo(a)pyrene. This was reflected in the results of the host-mediated assay and determinations of the mutagenic activities of the urine, with the use of the sensitive tester strains TA100 and TA98 of Salmonella typhimurium his- developed by Ames and coworkers. Treatment with BHA was effective also in reducing the mutagenic activities in vivo of hycanthone, three other antischistosomal compounds, metronidazole, diazepam, and mebendazole. These effects were accompanied by increases in the thiol levels of some tissues. The production of mutagenic metabolites of two other antischistosomal drugs, 4-isothiocyano-4'-nitrodiphenylamine and oxamniquine, was not reduced by BHA treatment. However, such reductions in mutagenicity could be achieved by the administration of enteric antibacterial agents, implicating the role of intestinal microorganisms in the mutagenic activation of certain chemical agents. Combined treatment of mice with BHA and enteric antimicrobial agents reduced the levels of mutagens derived from metronidazole by more than 90%, and the combined treatments were more effective than was either treatment alone.

Saccharin and other sweeteners: mutagenic properties

Saccharin preparations commonly distributed as artificial sweeteners exhibited mutagenic activity in bacterial tests. When administered orally to mice, mutagenic activity was demonstrable in the urines of these animals as well as in a host-mediated assay. Highly purified saccharin was not mutagenic in the direct assay, but the urines of mice to which this material had been administered exhibited mutagenic effects on one tester strain (Salmonella typhimurium TA100). Two other sweeteners, neohesperidin dihydrochalcone and xylitol, had no detectable mutagenic activity in any of these assays using his- Salmonella typhimurium strains TA100 or TA98.