Intravascular malignant lymphomatosis: diffusion-weighted magnetic resonance imaging characteristics.

Intravascular malignant lymphomatosis is an unusual condition in which malignant lymphoma cells form microscopic masses within the blood vessels of the central nervous system. Occlusion of the involved blood vessels can lead to multifocal cerebral infarcts. Diffusion-weighted magnetic resonance imaging (MRI) reveals a subacute infarction pattern (bright high signal intensity on b = 1000 s/mm2 images and intermediate apparent diffusion coefficient values) in the cerebral deep white matter. We present MRI findings of a 68-year-old woman with intravascular malignant lymphomatosis involving the cerebral white matter and the thoracic cord.

Biphasic mechanism for hypothermic induced loss of protein synthesis in hepatocytes.

BACKGROUND: A complication in liver transplantation is increased clotting times due to inhibition of protein synthesis resulting from prolonged hypothermic preservation. Protein synthesis is also blocked in cold preserved hepatocytes. In this study, the mechanism of inhibition of protein synthesis in cold preserved hepatocytes was investigated. METHODS: Hepatocytes prepared from rat liver were cold preserved in University of Wisconsin solution for 4, 24, and 48 hr. Protein synthesis was measured as incorporation of radiolabeled leucine into acid precipitable proteins. Hepatocytes were treated with antioxidants (dithiothreitol, trolox or deferoxamine, nitric oxide synthase inhibitor (N(G)-monomethyl-L-arginine monoacetate), steroids (dexamethasone or methylprednisolone), methods to keep adenosine triphosphate high (aerobic storage), and cytoskeletal disrupting agents (cytochalasin D or colchicine). RESULTS: There was a 26% decrease in protein synthesis after only 4 hr of cold storage and a further 25% decrease at 24 hr. Antioxidants, elevated adenosine triphosphate, and N(G)-monomethyl-L-arginine monoacetate did not affect the rate of loss of protein synthesis. Protein synthesis was not due to inhibition of amino acid transport or lack of amino acids in the storage medium. Steroid pretreatment of hepatocytes had no effect on the loss of protein synthesis occurring in the first 4 hr of storage but did suppress the loss occurring during the next 44 hr of storage. Cytoskeletal disrupting agents, added to freshly isolated cells, inhibited protein synthesis. CONCLUSION: The mechanism of loss of protein synthesis in cold preserved liver cells is not mediated by: (1) oxygen free radical generation or improved by antioxidant therapy, (2) nitric oxide generation in hepatocytes, (3) an adenosine triphosphate-sensitive destruction of cell viability, and (4) decreased permeability of amino acids or loss of amino acids from the cells. Loss of protein synthesis due to hypothermic storage appears biphasic. The first phase, occurring within 4 hr of storage, may be the result of the effects of hypothermia on the cell cytoskeletal system and may be untreatable. The second phase, which occurs during the next 24 to 48 hr is sensitive to steroid pretreatment. This phase may be amenable to improved preservation methodology. Improved preservation of the liver may require the use of steroids to conserve protein synthetic capabilities.

[Transcatheter arterial embolization with SMANCS and epiADM for hepatocellular carcinoma].

We have attempted transcatheter arterial embolization (TAE) with SMANCS and epiADM for 40 patients with hepatocellular carcinoma and evaluated its therapeutic effects and side effects. There were 7 cases of stage I disease, 10 cases of stage II disease, 10 cases of stage III disease and 13 cases of stage IV disease. Patients underwent TAE superselectively following infusion of w/o emulsion of epiADM and SMANCS-lipiodol. No severe side effect was observed compared with conventional Lp-TAE except in one case with hepatic biloma after treatment. The overall response rate was 70%, and 54.5% in the patients with recurrent tumor after Lp-TAE. The serum AFP value decreased in 16 patients out of 20 patients. Hepatic resection was performed in 2 patients after treatment, and no viable tumor cell was recognized in the specimen. Our result suggested that TAE with SMANCS and epiADM will contribute to improved therapeutic efficacy for hepatocellular carcinoma.

Gel Formation from Industrial Milk Whey Proteins under Hydrostatic Pressure: Effect of Hydrostatic Pressure and Protein Concentration.

The effects of high hydrostatic pressure and protein concentration on the denaturation and gelation of whey protein were investigated. Industrial whey protein isolate (WPI) and whey protein concentrate (WPC) solutions (pH 6.8) at various concentrations were pressurized for 10 min at 30 degrees C under 200-1000 MPa. With the WPI solution, the concentration for affecting the turbidity was 1% and was 6% for the viscosity at 400 MPa, while for inducing gelation, it was 10% at 600 MPa. With the WPC solution, the viscosity changed at a concentration >12%, and gel formation began at >18% at 400 MPa. The hardness and breaking stress of pressure-induced WPI gels increased with increasing concentration of WPI (12-18%) and hydrostatic pressure, the ratings for the 20% WPC gels being one-third those of the 20% WPI gels. The solubility of proteins from the pressure-induced WPI gels decreased with increasing pressure, while that of WPC gel induced at >600 MPa remained constant at approximately 50%. The microstructure of the WPI gels had a porous network form, whereas the WPC gels were irregular particulates. beta-Lactoglobulin, alpha-lactalbumin, and serum albumin preferentially participated in pressure-induced aggregation and gelation through S-S bonding.

Preservation of bladder tissue in different solutions for varying times.

OBJECTIVES: To evaluate three popular storage media and the effect of 24-hour cold storage on bladder tissue. METHODS: Guinea pig bladders were stored in three solutions: UW solution (a media used for transplant organs), Reznikoff solution [cell culture medium], and Krebs' solution with and without aeration. RESULTS: Cell potassium and sodium concentrations and total tissue water (a measurement of cell swelling) are important parameters for evaluating tissue damage. Reznikoff solution and Krebs' solution without gases maintained tissues for 24 hours with the least tissue damage; these solutions require no special equipment or attention. Twenty-four hour uniterrupted aeration of Krebs' solution caused the greatest degree of cell swelling with possible redistribution of receptors and required adjustment and regulation of the preservation apparatus. UW solution induced dehydration of cells, required the longest recovery period after cold storage, and is far more expensive than the other solutions. CONCLUSIONS: Reznikoff solution caused consistent relative changes in smooth muscle receptors and was superior to aerated Krebs' and UW solutions for 24-hour bladder tissue storage. It is unnecessary to aerate Krebs' solution during 24-hour cold storage.

The effect of calcium in the UW solution on preservation of the rat liver.

In this study we investigated the effect of calcium addition to the UW solution on the quality of the preserved rat liver as judged by normothermic isolated perfusion. Rat livers were cold stored in UW solution containing varying concentrations of calcium chloride (0, 0.5, 1.5, 5.0 mM) for periods of 0, 24 and 48 hours. At the end of the preservation period the livers were reperfused for 90 minutes at 37 degrees C with Krebs Henseleit Buffer. The quality of preservation was assessed by quantification of enzyme release, bile production and protein synthesis. The addition of 1.5 mM calcium to the UW solution suppressed the incidence of damage in the 24 hour cold stored liver similar to control livers (0 hours preserved). LDH release were significantly reduced from 22.1 +/- 7.3 (units/hr/g) in regular UW to 9.4 +/- 0.8 (units/hr/g) in UW plus 1.5 mM calcium. AST release also was suppressed by the addition of calcium to the UW. Bile production was enhanced by the addition of calcium; from 21.3 +/- 0.6 (mg/hr/g) in regular UW to 46.3 +/- 5.9 (mg/hr/g) in UW plus 1.5 mM calcium. Protein synthesis was reduced to 38% of control after 24 hr cold storage and was unchanged by the addition of calcium to the preservation solution. Although the addition of calcium to the UW solution improved the preservation of the 24 hour cold stored liver it did not offer the same degree of protection to the 48 hour preserved liver. Therefore, calcium addition may be one agent for improving preservation for short term cold storage of the liver but longer term storage will require other modifications as well.

Time-course changes of contrast enhancement in iron colloid enhanced MRI in patients with hepatocellular carcinoma.

Time-course changes in contrast enhancement of chondroitin sulphate iron colloid (CSIC), an MR contrast agent, were determined in 12 patients with 20 lesions of classical hepatocellular carcinoma (HCC). Spin echo T1 weighted (T1WI) and T2 weighted images (T2WI) were obtained before administration of CSIC and 1, 6 and 24 h after injection. The signal-to-noise ratio (SNR) in the tumour region and the liver and the tumour-to-liver contrast-to-noise ratio (CNR) were calculated, and time-course changes of these ratios were determined. SNRs for tumour before the administration of contrast medium did not differ significantly from SNRs after administration on T1WI or T2WI. SNRs for the liver on both T1WI and T2WI were significantly lower at each time point after administration than before administration. The tumour-to-liver CNRs for both T1WI and T2WI were significantly higher after administration than before administration. The maximum CNR was observed 6 h after administration on both T1WI and T2WI. The contrast enhancement was maintained for at least 24 h, with a peak at 6 h after administration. The prolonged enhancement obtained with CSIC has extended the time during which effective contrast is maintained.

Use of iron colloid-enhanced MRI for study of acute radiation-induced hepatic injury.

We present a case with acute radiation-induced hepatic injury using chondroitin sulfate iron colloid (CSIS)-enhanced MRI. Uptake of CSIC was decreased in the irradiated portion of the liver. CSIC-enhanced MRI is useful for obtaining information on the function of the reticuloendothelial system and demarcates between irradiated and nonirradiated zones.

Effect of hypothermia on intracellular Ca2+ in rabbit renal tubules suspended in UW-gluconate preservation solution.

Altered cellular calcium (Ca) homeostasis may be important in mediating hypothermic injury in preserved kidneys. In this study the effect of hypothermic (5 degrees C) storage on ionized intracellular Ca concentration ([Ca]i) in rabbit tubules was examined using Indo-1. Tubules were stored up to 250 min in UW-gluconate solution containing either 0.0, 0.5, 1.5, or 5.0 mM Ca (yielding about 3.6, 62, 371, and 1,010 microM ionized solution Ca (Ca2+) at 5 degrees C, respectively). [Ca]i increased to about 1,600 nM within 1 min after suspension in UW solution followed by a decrease in [Ca]i during the subsequent 60 min in all groups, suggesting mitochondrial Ca sequestration. Thereafter, [Ca]i either 1) increased in tubules incubated with 1.5 and 5.0 mM Ca to levels greater than 2,500 nM; 2) decreased to about 800 nM in tubules incubated with 0.5 mM Ca and then remained stable; or 3) continued to decrease in tubules incubated with 0.0 mM added Ca to reach an apparent steady-state concentration of about 175 nM after 180 min of incubation. The early spike in [Ca]i was unaffected by adding EGTA (solution Ca2+ = 50 nM). Ryanodine eliminated the [Ca]i spike, indicating that cooling in UW-gluconate solution caused release of endoplasmic reticulum Ca. This study shows that [Ca]i initially increases after exposure to UW-gluconate solution and appears to be transiently buffered through intracellular, probably mitochondrial, sequestration. Saturation of cellular buffer mechanisms resulted in a sustained dependence of [Ca]i on extracellular Ca2+. These results support the hypothesis that the effect of Ca on kidney viability is related to solution-induced alterations in [Ca]i.

Regeneration of ATP in kidney slices after warm ischemia and hypothermic preservation.

The current shortage of cadaveric kidneys may be alleviated to some degree by increasing our capabilities to use less than ideal donor kidneys, such as those from non-heart-beating donors. These kidneys are often exposed to no flow (ischemia) for varying lengths of time. Full utilization of these kidneys may require better methods of organ preservation that could reverse existing ischemic injury. This may conceivably require that, during preservation, energy stores (ATP) lost during warm ischemia be recharged. This would required continuous perfusion. Using a kidney slice model, we investigated the effects of simulated hypothermic machine perfusion with the UW gluconate perfusate on the capability of rabbit kidneys exposed to warm ischemia to regenerate ATP. After 30 min of warm ischemia, ATP content was low (0.2 mumol/g wet weight) but increased to 0.7-0.9 mumol/g wet weight after 24 h of simulated machine perfusion at 4 degrees C. After an additional 2 h of rewarming (37 degrees C in oxygenated Krebs Henseleit buffer), the slice ATP content increased to about 1.0 mumol/g wet weight (similar to kidneys not exposed to warm ischemia) when the antioxidants desferrioxamine and N-2-(mercaptopropionyl) glycine were included in the preservation media. Significantly less ATP was present without the antioxidants. After 60 min of warm ischemia, less ATP was regenerated after 24 h of simulated machine perfusion (about 0.4 mumol/g wet weight) than after 30 min of warm ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Cytoprotective effect of glycine in cold stored canine renal tubules.

Reperfusion injury has been suggested to cause delayed graft function in renal transplantation. Methods to reduce reperfusion injury could lead to improved clinical renal transplantation. Glycine has been shown to suppress reperfusion injury in rabbit renal tubules and rat hepatocytes. In this study we have determined the effects of glycine on viability of isolated canine renal tubules. Renal tubules were cold stored at 4 degrees C under hypoxic conditions for up to 96 h in the UW solution and rewarmed to 37 degrees C for up to 2 h under oxygenated conditions to simulate reperfusion of an organ after cold static storage. Short-term storage (24 to 48 h) did not cause membrane injury (leakage of lactate dehydrogenase (LDH)) on rewarming. However, after 72 and 96 h cold storage reperfusion injury was evident and LDH leakage increased from about 25% to 59 +/- 3% and 71 +/- 2% at 72 and 96 h cold storage, respectively. The presence of 3 mM glycine in the reperfusion medium suppressed injury to cold-stored renal tubules. After cold storage for 72 and 96 h LDH leakage was reduced to control concentrations (31 +/- 3% and 29 +/- 1%, respectively). After cold storage for 72 h there was a reduction in ATP concentration in rewarmed renal tubules (3 nmol/mg protein at 48 h to 1.25 nmol/mg protein at 72 h). Also, there was a loss of mitochondrial functions including decreased stimulation of oxygen consumption by uncoupling of oxidative phosphorylation. Although glycine suppressed LDH leakage in renal tubules cold stored for 72 h it had no effect on the regeneration of ATP or mitochondrial functions, which remained depressed.(ABSTRACT TRUNCATED AT 250 WORDS)

Important components of the UW solution.

The UW solution for preservation of the liver, kidney, and pancreas contains a number of components, and the importance of each of these has not been fully resolved. In the studies reported here the importance of glutathione and adenosine is demonstrated in isolated cell models (rabbit renal tubules and rat liver hepatocytes) of hypothermic preservation and reperfusion and in dog renal transplantation. Glutathione in the UW solution is necessary for the preservation of the capability of the cell to regenerate ATP and maintain membrane integrity. Adenosine in the UW solution provides the preserved cell with substrates for the regeneration of ATP during the reperfusion period following cold storage. The omission of GHS from the UW solution results in poorer renal function in the 48 hr dog kidney preservation-transplant model. The role of other components of the UW solution is discussed including lactobionic acid; other impermeants; and the colloid, hydroxyethyl starch. It is concluded that the development of improved preservation solutions will require a more detailed understanding of the mechanism of injury due to cold storage and, once obtained, solutions more complex than the UW solution may be required for improved long-term storage of organs.

Hypothermic perfusion of rabbit livers: effect of perfusate composition (Ca and lactobionate) on enzyme release and tissue swelling.

Rabbit livers were preserved by continuous hypothermic (5 degrees C) perfusion at a flow rate of 1 ml/min-1 g-1 for as long as 72 hr. Cell swelling (total tissue water, TTW) and the rate at which intracellular enzymes were released into the perfusate were measured. Livers perfused with a simple NaCl-based solution containing hydroxyethyl starch as a colloid released relatively large amounts of aspartate aminotransferase (AST, 442 +/- 224 u/liter-1 100 g-1) and lactic dehydrogenase (LDH, 1580 +/- 688 u/liter-1 100 g-1) into the perfusate during 72 hr of perfusion. The addition of Ca (0.5 mmol/liter) to the perfusate reduced the leakage of enzymes into the perfusate (AST, 70 +/- 30 u; LDH, 450 +/- 50 u) and reduced cell swelling (TTW, 3.1 kg/kg dry mass vs 4.4 kg/kg dry mass without added Ca). But the use of a higher concentration of Ca (1.5 mmol/liter) caused membrane damage (AST, 4000 +/- 1500 u; LDH, 10,000 +/- 2222 u) and increased cell swelling (TTW, 3.7 kg/kg dry mass). The release of intracellular enzymes caused by continuous perfusion with a chloride-based perfusate also could be reduced by replacing the chloride with lactobionate (AST, 100 +/- 30 u; LDH, 400 +/- 100 u, at 72 hr). In the lactobionate-containing perfusate, the addition of Ca (0.5 or 1.5 mmol/liter) did not alter the rate at which intracellular enzymes were released. There was no tissue swelling after 72 hr of preservation with the lactobionate-containing perfusate, and the TTW (2.1 kg/kg dry mass) was similar to the TTW of freshly harvested rabbit livers.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of short-term hypothermic perfusion and cold storage on function of the isolated-perfused dog kidney.

The isolated-perfused dog kidney was used as a model to measure the effects of short-term hypothermic preservation on renal function and metabolism. Kidneys were cold-stored in Collins' solution, hypotonic citrate, or phosphate-buffered sucrose for 4 and 24 hr, or were continuously perfused for 4 and 24 hr with a synthetic perfusate. Following preservation kidneys were perfused with an albumin-containing perfusate at 37 degrees C for 60 min for determination of renal function. The results indicate that many of the effects of short-term preservation on renal function in dog kidneys are similar to results reported for rat and rabbit kidneys. Cold storage for 4 hr resulted in a large decrease in GFR (57%), but only a small decrease in Na reabsorption (from 97 to 87%). Cold storage for 24 hr caused a further decline in renal function (GFR = 95% decrease, Na reabsorption = 49-64%). Results were similar for all cold storage solutions tested. Perfusion for 4 hr was less damaging to renal function than cold storage. The GFR decreased only 14% and urine formation and Na reabsorption were practically normal. After 24 hr of hypothermic perfusion, the GFR was reduced by 79%, urine flow was normal, and Na reabsorption was 78%. There were no obvious biochemical correlates (adenine nucleotides, tissue edema, or electrolyte concentration) with the loss of renal function during short-term preservation. The results suggest that the isolated-perfused dog kidney can be used to test the effects of preservation on renal function, and yields results similar to those obtained using small animal models.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of the effect of 3- and 5-day hypothermic perfusion of dog kidneys on metabolism of tissue slices.

Hypothermic perfusion effectively preserves the viability of kidneys for 3 days. Long-term preservation (5 days or greater) has not been consistently obtained. In this study, the differences between kidneys perfused for 3 and 5 days were compared by determining the "integrated-metabolic" capabilities of tissue slices incubated in vitro at 30 degrees C. The "integrated-metabolic" parameters determined include (1) respiration rates, (2) cell volume regulation [total tissue water (TTW) and saccharide permeable space], (3) rate of reaccumulation of K+ and pumping of Na+, (4) maintenance of ATP concentrations, and (5) mitochondrial functions. Conditions that result in high and low concentrations of ATP following perfusion of kidneys for 5 days were also compared for effects on tissue slice metabolism. The results indicate that energy metabolism in tissue slices is well preserved under all conditions and times of perfusion of kidneys. This includes average respiration rates (315 +/- 50, 275 +/- 35, and 255 +/- 45 mumol O2/hr/g dry wt at 0, 3, and 5 days, respectively, mitochondrial function [respiratory control ratio (RCR) = 4.6, 4.0, and 4.1 for 0, 3, and 5 days, respectively], and steady-state concentration of ATP in slices after incubation (4.0 +/- 1.45, 3.9 +/- 1.28, and 3.3 +/- 0.81 mumol/g/dry wt, for 0, 3, and 5 days, respectively). The primary differences between 3- and 5-day perfused kidneys were the capability of the slices to regulate cell volume and reaccumulate K+. Slices from kidneys perfused for 3 days maintained the TTW at 3.8 kg/kg dry wt, a value similar to that of control tissue slices. However, slices from 5-day perfused kidneys remained swollen (TTW = 4.6 kg/kg dry wt). Also, slices from the 5-day perfused kidney pumped K+ at less than one-half the rate found in slices from control or 3-day preserved kidneys. No significant differences were apparent in the permeability properties of the tissue slices from kidneys perfused for 3 and 5 days to radiolabeled saccharides. The defects in membrane-linked transport functions, resulting from long-term kidney perfusion, were reduced in kidneys containing a high concentration of ATP. The results suggest that one factor which may limit successful preservation of kidneys is the increased membrane permeability (to electrolytes) which is partially prevented by maintaining elevated concentrations of tissue ATP during perfusion.