Heparin-binding EGF-like growth factor (HB-EGF) antisense oligonucleotide protected against hyperlipidemia-associated atherosclerosis

BACKGROUND AND AIMS

Heparin-binding EGF-like growth factor (HB-EGF) is a representative EGF family member that interacts with EGFR under diverse stress environment. Previously, we reported that the HB-EGF-targeting using antisense oligonucleotide (ASO) effectively suppressed an aortic aneurysm in the vessel wall and circulatory lipid levels. In this study, we further examined the effects of the HB-EGF ASO administration on the development of hyperlipidemia-associated atherosclerosis using an atherogenic mouse model.

METHODS AND RESULTS

The male and female LDLR deficient mice under Western diet containing 21% fat and 0.2% cholesterol content were cotreated with control and HB-EGF ASOs for 12 weeks. We observed that the HB-EGF ASO administration effectively downregulated circulatory VLDL- and LDL-associated lipid levels in circulation; concordantly, the HB-EGF targeting effectively suppressed the development of atherosclerosis in the aorta. An EGFR blocker BIBX1382 administration suppressed the hepatic TG secretion rate, suggesting a positive role of the HB-EGF signaling for the hepatic VLDL production. We newly observed that there was a significant improvement of the insulin sensitivity by the HB-EGF ASO administration in a mouse model under the Western diet as demonstrated by the improvement of the glucose and insulin tolerances.

CONCLUSION

The HB-EGF ASO administration effectively downregulated circulatory lipid levels by suppressing hepatic VLDL production rate, which leads to effective protection against atherosclerosis in the vascular wall.

Targeted delivery of antisense oligonucleotides to pancreatic β-cells

Antisense oligonucleotide (ASO) silencing of the expression of disease-associated genes is an attractive novel therapeutic approach, but treatments are limited by the ability to deliver ASOs to cells and tissues. Following systemic administration, ASOs preferentially accumulate in liver and kidney. Among the cell types refractory to ASO uptake is the pancreatic insulin-secreting β-cell. Here, we show that conjugation of ASOs to a ligand of the glucagon-like peptide-1 receptor (GLP1R) can productively deliver ASO cargo to pancreatic β-cells both in vitro and in vivo. Ligand-conjugated ASOs silenced target genes in pancreatic islets at doses that did not affect target gene expression in liver or other tissues, indicating enhanced tissue and cell type specificity. This finding has potential to broaden the use of ASO technology, opening up novel therapeutic opportunities, and presents an innovative approach for targeted delivery of ASOs to additional cell types.

Referrals for Movement Disorder Surgery: Under-Representation of Females and Reasons for Refusal

OBJECTIVE

Referral of movement disorder patients for deep brain stimulation surgery was examined to determine whether referred patients were representative of gender proportions in our population, and reasons why patients do not proceed to surgery.

METHODS

Demographic information on referrals to the surgical program was retrospectively reviewed from our database and from a detailed chart review.

RESULTS

Although almost equal numbers of movement disorder patients are male and female, of the 91 patients referred for surgery, only 31% were female. Sixty-one percent of referred patients did not undergo surgery. Of these, the majority were denied for medical reasons, including cognitive decline (21%), psychiatric concerns (5%) and neurological reasons (42%).

CONCLUSIONS

Almost one-third of patients referred for movement disorder surgery were denied for medical reasons. This underscores the importance of evaluation of all potential patients by a multidisiplinary team to fully assess suitablity for stereotactic surgery. Interestingly, women were under-represented in those referred. In order that all appropriate patients have the opportunity to consider surgery, education of both physicians and patients, and different strategies to approach females regarding surgery may allow more patients to benefit from this treatment.

Quantitative Analysis of Human Movement Synergies: Constructive Pattern Analysis for Gait

To record three-dimensional coordinates of the joints from normal human subjects during locomotion, we used a digital motion analysis system (ELITE). Recordings were obtained under several different conditions, which included normal walking and stepping over obstacles. Principal component analysis was used to analyze coordinate data after conversion of the data to segmental angles. This technique gave a stable summary of the redundancy in gait kinematic data in the form of reduced variables (principal components). By modeling the shapes of the phase plots of reduced variables (distortion analysis) and using a limited number of model parameters, good resolution was obtained between subtly different conditions. Hence, it was possible to accurately resolve small distributed changes in gait patterns within subjects. These methods seem particularly suited to longitudinal studies in which relevant movement features are not known a priori. Assumptions and neurophysiological applications are discussed.

A TELE-EMERGENT SYSTEM FOR LONG-TERM ECG MONITORING OVER WIRELESS SENSOR NETWORK

This paper presents the design and implementation of a tele-emergent system to provide constant monitoring of cardiac patients. Our system is consisted of a user integration device attached to the patient, a wireless sensor network (WSN) and a medical gateway installed in the patient's home, and a server set up in the hospital. The user integration device includes Electrocardiogram (ECG) signal acquisition and processing circuit utilizing a "Modified So and Chan" QRS detection algorithm to discriminate the R signal wave and calculate RR intervals to subsequently detect abnormal Heart Rate Variability (HRV), and a Bluetooth transmission module to communicate with WSN. The WSN which is consisted of wireless sensor nodes with power-saving scheme is used to relay the ECG data to the medical gateway for ubiquitous monitoring at home. The medical gateway includes the heart disease symptom recognition system to further analyze the ECG data and recognize the symptoms of serious heart diseases, and a General Packet Radio Service (GPRS) module with Multimedia Messaging Service (MMS) to communicate with the server in the hospital. The server in the hospital can passively process the MMS messages from the medical gateway, and actively send commands to the medical gateway to acquire the needed ECG data from the patient. With our integrated system it is possible to provide real-time and long-term monitoring of physiological data for cardiac patients which is vital for the patients' medical care.

AOC reduction by biologically active filtration

Biological treatment was examined for production of biologically stable water, increase disinfectant stability, and reduced formation of disinfection by products. Monitoring of assimilable organic carbon (AOC) levels in the effluent of the Swimming River Treatment Plant (SRTP) showed that values >100 µg/L could be related to the occurrence of coliform bacteria in the distribution system. A treatment goal of <100 µg/L was established for biologically active treatment processes. Granular activated carbon (GAC) filters were found to support a larger bacterial population, and thus, provide better biological removal of AOC and total organic carton (TOC). All biologically active filters showed good performance relative to effluent turbidity levels, and headloss development. Preozonation of raw water increased AOC levels an average of 2.3 fold, and always increased filter effluent AOC levels relative to nonozonated water. Application of free chlorine to GAC filters did not inhibit biological activity. Application of chloramines to GAC filters showed a slight inhibitory affect relative to free chlorine. Effluent AOC levels averaged 82 µg/L at an EBCT of 5 min, and decreased to an average of 57 µg/L at 20 min EBCT. EBCT did affect TOC removals, with efficiencies averaging 29, 33, 42, and 51 % removal at EBCTs of 5, 10, 15 and 20 min, respectively. Trihalomethane formation potentials (THMFP) were related to TOC levels. Processes Chat decreased TOC levels also decreased THMFP. A preozonated GAC/sand filter (EBCT 10 min) achieved an annual average 54 % removal of THMFP precursors. Post disinfection of biologically treated effluents reduced HPC bacterial counts by 2-2.5log10. Post chlorination or chloramination of prechlorinated GAC/sand effluents resulted in a 20 %, or a 44 % (respectively) increase in AOC levels. Post disinfection of preozonated water resulted in small (<8%) AOC increases. Despite increases in AOC levels, prechlorinated water had lower AOC levels than preozonated water, even after post disinfection.

Acyl coenzyme A: cholesterol acyltransferase types 1 and 2: structure and function in atherosclerosis

Two enzymes are responsible for cholesterol ester formation in tissues, acyl coenzyme A:cholesterol acyltransferase types 1 and 2 (ACAT1 and ACAT2). The available evidence suggests different cell locations, membrane orientations, and metabolic functions for each enzyme. ACAT1 and ACAT2 gene disruption experiments in mice have shown complementary results, with ACAT1 being responsible for cholesterol homeostasis in the brain, skin, adrenal, and macrophages. ACAT1 -/- mice have less atherosclerosis than their ACAT1 +/+ counterparts, presumably because of the decreased ACAT activity in the macrophages. By contrast, ACAT2 -/- mice have limited cholesterol absorption in the intestine, and decreased cholesterol ester content in the liver and plasma lipoproteins. Almost no cholesterol esterification was found when liver and intestinal microsomes from ACAT2 -/- mice were assayed. Studies in non-human primates have shown the presence of ACAT1 primarily in the Kupffer cells of the liver, in non-mucosal cell types in the intestine, and in kidney and adrenal cortical cells, whereas ACAT2 is present only in hepatocytes and in intestinal mucosal cells. The membrane topology for ACAT1 and ACAT2 is also apparently different, with ACAT1 having a serine essential for activity on the cytoplasmic side of the endoplasmic reticulum membrane, whereas the analogous serine is present on the lumenal side of the endoplasmic reticulum for ACAT2. Taken together, the data suggest that cholesterol ester formation by ACAT1 supports separate functions compared with cholesterol esterification by ACAT2. The latter enzyme appears to be responsible for cholesterol ester formation and secretion in lipoproteins, whereas ACAT1 appears to function to maintain appropriate cholesterol availability in cell membranes.

12-O-Tetradecanoylphorbol-13-acetate Induces Apoptosis in Renal Epithelial Cells through a Growth Signal Conflict Which Is Prevented by Activated ras1

12-O-Tetradecanoylphorbol-13-acetate (TPA) induced apoptosis in the pig renal epithelial cell line LLC-PK1 after 24 h of treatment as assessed by caspase 3 activation. Cotreatment of the cells with bryostatin markedly reduced the apoptotic effects of TPA. Okadaic acid, another tumor promoter, also induced apoptosis. Expression of an activated ras gene prevented TPA-induced apoptosis, while a dominant negative ras retarded the process. Taken together, these results suggest that TPA-induced apoptosis in LLC-PK1 may be analogous to TPA-induced tumor promotion in the two-stage model of skin carcinogenesis. Mechanistically, TPA-induced apoptosis seemed to be the result of a conflict of the growth-promoting affects of serum and the growth-retarding effects of TPA. This was manifested by a pronounced hypophosphorylation of the retinoblastoma gene product, pRb, which was prevented by activated ras. Apoptosis and pRb hypophosphorylation were associated with a reduction in cyclin D1 levels, suggesting that the growth-retarding effects of TPA were produced by modulation of this cell cycle protein. Interestingly, the mechanism of protection by activated ras did not seem to result from downstream activation of phosphatidylinositol-3-kinase (PI3K) as has been implicated in other systems. Additional analysis revealed that TPA-induced apoptosis was associated with the downregulation of the anti-apoptotic proteins Bcl-x and Mcl-1 and dependent on the activity of the transcription factor Jun.

Differential expression of ACAT1 and ACAT2 among cells within liver, intestine, kidney, and adrenal of nonhuman primates

Two closely related enzymes with more than 50% sequence identity have been identified that catalyze the esterification of cholesterol using acyl-CoA substrates, namely acyl-CoA:cholesterol acyltransferase 1 (ACAT1) and ACAT2. Both are membrane-spanning proteins believed to reside in the endoplasmic reticulum of cells. ACAT2 has been hypothesized to be associated with lipoprotein particle secretion whereas ACAT1 is ubiquitous and may serve a more general role in cellular cholesterol homeostasis. We have prepared and affinity purified rabbit polyclonal antibodies unique to either ACAT enzyme to identify their cellular localization in liver and intestine, the two main lipoprotein-secreting tissues of the body, and for comparison, kidney and adrenal. In the liver, ACAT2 was identified in the rough endoplasmic reticulum of essentially all hepatocytes whereas ACAT1 was confined to cells lining the intercellular spaces among hepatocytes in a pattern typical of Kupffer cells. In the intestine, ACAT2 signal was strongly present in the apical third of the mucosal cells, whereas ACAT1 staining was diffuse throughout the mucosal cell, but with strong signal in goblet cells, Paneth cells, and villus macrophages. In the kidney, ACAT1 immunostaining was specific for the distal tubules and podocytes within the glomerulus. In the adrenal, ACAT1 signal was strongly present in the cells of the cortex, and absent from other adrenal cell types. No ACAT2 signal was identified in the kidney or adrenal. We conclude that only the cells of the liver and intestine that secrete apolipoprotein B-containing lipoproteins contain ACAT2, whereas ACAT1 is present in numerous other cell types. The data clearly suggest separate functions for these two closely related enzymes, with ACAT2 being most closely associated with plasma cholesterol levels.

ACAT1 and ACAT2 membrane topology segregates a serine residue essential for activity to opposite sides of the endoplasmic reticulum membrane

A second form of the enzyme acyl-CoA:cholesterol acyltransferase, ACAT2, has been identified. To explore the hypothesis that the two ACAT enzymes have separate functions, the membrane topologies of ACAT1 and ACAT2 were examined. A glycosylation reporter and FLAG epitope tag sequence was appended to a series of ACAT cDNAs truncated after each predicted transmembrane domain. Fusion constructs were assembled into microsomal membranes, in vitro, and topologies were determined based on glycosylation site use and accessibility to exogenous protease. The accessibility of the C-terminal FLAG epitope in constructs was determined by immunofluorescence microscopy of permeabilized transfected cells. Both ACAT1 and ACAT2 span the membrane five times with their N termini in the cytosol and C termini in the ER lumen. The fourth transmembrane domain is located in a different region for each protein, placing the putative active site ACAT1 serine (Ser(269)) in the cytosol and the analogous residue in ACAT2 (Ser(249)) in the ER lumen. Mutation of these serines inactivated the ACAT enzymes. The outcome is consistent with the hypothesis that cholesterol ester formation by ACAT2 may be coupled to lipoprotein particle assembly and secretion, whereas ACAT1 may function primarily to maintain the balance of free and esterified cholesterol intracellularly.

Lateral leg raising in patients with Parkinson's disease: influence of equilibrium constraint

Patients with Parkinson's disease often have difficulty maintaining postural stability. This impairment is attributed to postural adjustment deficits. We studied the postural adjustments associated with the performance of two complex tasks which differed only in the final equilibrium constraints. Ten patients with Parkinson's disease and six age-matched control subjects were asked to raise one leg laterally to an abduction angle of approximately 45 degrees as fast as possible to the right or left in random order. In the first series of tests, the subjects were instructed to maintain the leg at 45 degrees, whereas in the second series they were instructed to place their foot back on the ground. Recordings included ground reaction forces and kinematics. In the patients with Parkinson's disease the final posture for the first task was never maintained. The strategy used to shift the body weight was different for the two groups. In control subjects, it was initiated by a whole body rotation around the ankle followed by a trunk inclination around the hip. Conversely, in patients with Parkinson's disease, the shift of the body weight was initiated by a trunk inclination around the hip and then by a whole body rotation around the ankle. The amplitude of the trunk inclination toward the supporting side was smaller than in the control subjects. The second task with less severe equilibrium constraints was, on the whole, better performed by the patients even though the same postural adjustment deficits were present.

Home telecare system using cable television plants--an experimental field trial

To solve the inconvenience of routine transportation of chronically ill and handicapped patients, this paper proposes a platform based on a hybrid fiber coaxial (HFC) network in Taiwan designed to make a home telecare system feasible. The aim of this home telecare system is to combine biomedical data, including three-channel electrocardiogram (ECG) and blood pressure (BP), video, and audio into a National Television Standard Committee (NTSC) channel for communication between the patient and healthcare provider. Digitized biomedical data and output from medical devices can be further modulated to a second audio program (SAP) subchannel which can be used for second-language audio in NTSC television signals. For long-distance transmission, we translate the digital biomedical data into the frequency domain using frequency shift key (FSK) technology and insert this signal into an SAP band. The whole system has been implemented and tested. The results obtained using this system clearly demonstrated that real-time video, audio, and biomedical data transmission are very clear with a carrier-to-noise ratio up to 43 dB.

Prognostic value of abdominal CT scanning and hepatic histopathology in patients with acute liver failure

Acute liver failure has extremely high mortality without liver transplantation. We attempted to determine the value of abdominal CT scanning and liver biopsy in its management. A retrospective analysis of patients with acute liver failure was performed; demographic, clinical, radiologic and histopathologic features were noted. Over a period of 13 years, 177 patients were evaluated. The mean age was 39 years and 63% were females. The patients were divided into three groups. Fourteen percent survived with medical management (group I), 37% died (group II), and 49% had liver transplantation (group III). Most patients showed diffuse low density of the liver on CT scanning and the proportions were similar in the three groups. Moderate to large ascites was not present in group I but occurred in 31% of patients in group II and in 15% in group III. Mean hepatic volumes were similar in the three groups; however, 97% of the patients with a liver volume of less than 1000 ml either died or required liver transplantation. Liver biopsies among patients with spontaneous recovery (group I) were distinguished by the presence of regenerative changes and a hepatic parenchymal necrosis of less than 50%. These results suggest that in patients with acute liver failure a liver volume of less than 1000 ml and/or hepatic parenchymal necrosis of greater than 50% is indicative of a poor prognosis. This information may assist decision making in such patients, in particular, regarding the need for liver transplantation.

Effects of test H-reflex size on reciprocal inhibition in forearm muscles

We studied effects of test H-reflex size on reciprocal Ia inhibition in forearm muscles. In both healthy control subjects and hemiplegic patients, the amount of Ia inhibition decreased as the test H-reflex size increased. It is possible that forearm reciprocal Ia inhibition in hemiplegics reported previously might be underestimated due to larger test H-reflexes used in the hemiplegics than in the controls.

Recent advances in telemedicine

With continuing advances in information technology, the applications of computers in medicine are increasing rapidly. Modern information technology not only affects the delivery of health care, but also significantly influences the doctor-patient relationship. Since the 1990s, technologic developments in high-bandwidth telecommunications systems and digitizing devices have led to a surge of interest in telemedicine. In recent years, the Internet, with its powerful penetration and scalability, has become an increasingly popular medical information resource and a new platform for telemedicine. The impact of modern technology on the advancement of telemedicine in Taiwan started with the 1995 National Information Infrastructure project, which uses networks of different bandwidths for teleconsultation and distance education programs. In 1998, National Taiwan University and Taipei Medical College in Taiwan, and the University of Pittsburgh and the University of Iowa in the USA, began cooperation on a new Cyber Medical Center (CMC) project that integrates the technologies of multimedia, database management, a multiple-site videoconferencing system, and the World Wide Web. The aim of the CMC is to create a multimedia network system for the management of electronic patient records, teleconsultation, online continuing medical education, and information services on the Web. In the future, telemedicine systems in Taiwan are expected to combine the Internet and cable television to connect clinics, hospitals, insurance organizations, and public health administrations; and, finally, to extend health services to every household.

Cold preservation of the human colon and ileum with University of Wisconsin solution

The inclusion of the colon in the intestinal graft resulted in worsening patient and graft outcome and increased the incidence of infection and rejection. In this study, we examine the role of ischemia on the barrier function of the epithelium during cold ischemia. Samples were collected from 15 harvested and transplanted human donor grafts (colon, 10; ileum, 6), which were immersed in University of Wisconsin (UW) solution. Ischemia (6, 12, 24, and 48 h) and reoxygenation were performed to evaluate the mucosal electrical status using the Ussing chamber technique. The functions of enterocytes and crypt cells were tested by glucose and theophylline challenge. Modified Park's classification was applied to evaluate the severity of mucosal damage under light microscopy. The colon had higher levels of baseline potential difference, short-circuit current, and resistance than the ileum during 6 48 h of ischemia. Colonic epithelial cells responded well to theophylline stimulation at 24 h of ischemia, while there was no ileal response. The colonic mucosa was histopathologically well preserved in UW solution for 48 h, and mucosal damage induced by reoxygenation was less than in the ileum. In conclusion, electrophysiologically and histopathologically, the colon is less susceptible to cold preservation damage than the ileum during storage with UW solution.

Quantitative kinematics of gait patterns during the recovery period after stroke

BACKGROUND AND PURPOSE

The purpose of this study was to assess the potential of a new quantitative kinematic analysis for the documentation and evaluation of recovery of gait function after neurological injury.

METHODS

We assessed the kinematics of gait function in 16 patients with hemiplegia at varying intervals over a 1-year period after a stroke, using a novel method for gait pattern assessment based on principal component analysis. Conventional measures such as gait speed and stride length were also evaluated. Testing started as soon as patients became ambulatory after stroke.

RESULTS

Of the 16 patients assessed, 7 showed at least a 50% increase in self-selected gait speed from the first to the last test. The results of the pattern analysis closely mirrred self-selected gait speed at higher speeds, but relative rankings derived from gait speed and the pattern analysis did not match for 6 of the 16 patients. Kinematic pattern analysis suggested that different mechanisms were used to generate changes in gait speed at different speed levels.

CONCLUSION

There is a sizable fraction of the stroke population for whom kinematic gait pattern analysis can provide information that is different from that provided by speed, stride length, and cadence. The kinematic analysis can potentially provide information about the mechanisms of pathological gait.

Food intake patterns are altered during long-term zinc deficiency in rats

Rats experience anorexia and reduction or cessation in growth after being provided a zinc-deficient diet. While zinc deficient, intake levels may be reduced 50% or more compared to control rats. In the present report, diurnal food intake patterns of male Sprague-Dawley rats were measured during zinc deficiency. In Study 1, rats consuming a modified AIN-93 diet were tested during the dark phase using an automated food weighing system. In zinc-deficient animals (Zn-), the onset of the first meal of the dark phase was delayed compared to zinc-adequate rats (Zn+; 106+/-47 vs. 23+/-5 min; p<0.05) and the number of meals consumed during the dark phase was reduced in Zn- vs. Zn+ rats (3.9+/-0.5 vs 7.1+/-0.4; p<0.05). In Study 2, diurnal food intake patterns were tested using a three-choice macronutrient self-selection paradigm of carbohydrate-, protein-, and fat-containing diets made deficient or adequate in zinc (1 or 30 mg Zn/kg diet). Food intake was recorded in the early-, mid-, late-dark period (4 h each) and light period (12 h). Carbohydrate intake was 70% of total intake of both Zn+ and Zn- rats during the first 5 days, but decreased significantly to 50% in the Zn- group during the last 5 days. Fat intake increased significantly in the Zn- group during the last 5 days. This increase was the result of 4 of 15 Zn- rats increasing their intake of fat significantly. Results of this study indicate that zinc status alters dark phase and macronutrient selection patterns by delaying consumption of the initial meal of the dark phase, reducing the average meal number and by changing the dominant macronutrient preference of some Zn- rats.

Treatment of hilar cholangiocarcinoma (Klatskin tumors) with hepatic resection or transplantation

BACKGROUND

Because of the rarity of hilar cholangiocarcinoma, its prognostic risk factors have not been sufficiently analyzed. This retrospective study was undertaken to evaluate various pathologic risk factors which influenced survival after curative hepatic resection or transplantation.

METHODS

Between 1981 and 1996, 72 patients (43 males and 29 females) with hilar cholangiocarcinoma underwent hepatic resection (34 patients) or transplantation (38 patients) with curative intent. Medical records and pathologic specimens were reviewed to examine the various prognostic risk factors. Survival was calculated by the method of Kaplan-Meier using the log rank test with adjustment for the type of operation. Survival statistics were calculated first for each kind of treatment separately, and then combined for the calculation of the final significance value.

RESULTS

Survival rates for 1, 3, and 5 years after hepatic resection were 74%, 34%, and 9%, respectively, and those after transplantation were 60%, 32%, and 25%, respectively. Univariate analysis revealed that T-3, positive lymph nodes, positive surgical margins, and pTNM stage III and IV were statistically significant poor prognostic factors. Multivariate analysis revealed that pTNM stage 0, I, and II, negative lymph node, and negative surgical margins were statistically significant good prognostic factors. For the patients in pTNM stage 0-II with negative surgical margins, 1-, 3-, and 5-year survivals were 80%, 73%, and 73%, respectively. For patients in pTNM stage IV-A with negative lymph nodes and surgical margins, 1-, 3-, and 5-year survivals were 66%, 37%, and 37%, respectively.

CONCLUSIONS

Satisfactory longterm survivals can be obtained by curative surgery for hilar cholangiocarcinoma either with hepatic resection or liver transplantation. Redefining pTNM stage III and IV-A is proposed to better define prognosis.

Zinc deficiency increases hypothalamic neuropeptide Y and neuropeptide Y mRNA levels and does not block neuropeptide Y-induced feeding in rats

Zinc deficiency reduces intake and produces an unusual approximately 3.5-d cycle of intake in rats. The mechanism underlying the anorexia and cycling has not yet been defined; current hypotheses suggest that alterations in amino acid metabolism and neurotransmitter concentrations may be a part of this anorexia. Recent reports indicate that appetite-stimulating neuropeptide Y (NPY) may be elevated during zinc deficiency. This suggests that a resistance to NPY may exist during zinc deficiency because NPY levels are high, yet appetite is low. The purpose of this study was to measure NPY peptide and mRNA concentrations during zinc deficiency in specific nuclei of the hypothalamus in which peptide and mRNA for NPY are known to be associated with appetite, and also to determine whether zinc-deficient rats are responsive to central infusions of NPY. Both NPY peptide levels in the paraventricular nucleus and NPY mRNA levels in the arcuate nucleus were higher (P < 0.05) in zinc-deficient rats than in zinc-adequate rats. When rats were administered exogenous NPY to the paraventricular nucleus, both zinc-deficient and zinc-adequate rats responded similarly by increasing food intake. These results suggest that NPY is elevated during zinc deficiency in an attempt to restore normal food intake levels, rather than being reduced and thereby contributing to the anorexia associated with zinc deficiency. During zinc deficiency, NPY receptors are able to bind NPY and initiate an orexigenic response.

Spatio-temporal and kinematic analysis of pointing movements performed by cerebellar patients with limb ataxia

Three patients with cerebellar limb ataxia and three age-matched controls performed arm-pointing movements towards a visual stimulus during an experimental procedure using a double-step paradigm in a three-dimensional space. Four types of trajectories were defined: P1, single-step pointing movement towards the visual stimulus in the initial position S1; P2, double-step pointing movement towards S1; P3, double-step straight pointing movement towards the second position S2; and P4, double-step pointing movement towards S2 with an initial direction towards S1. We found that the cerebellar patients, as well as the controls, were able to modify their motor programs, but with impaired timing, severe anomalies in the direction and amplitude of the changed movement trajectories and alteration of the precision of the pointing movements.

Transforming growth factor alpha (TGFalpha) in hepatocellular carcinomas and adjacent hepatic parenchyma

We examined stage T1 to T4 hepatocellular carcinomas (HCC) to determine whether transforming growth factor alpha (TGFalpha) presence differed between early- and late-stage HCC and between tumors with low and high proliferative rates. Paraffin sections from 36 HCC were evaluated for TGFalpha and the proliferation markers Kiel 67 antigen (Ki67) or proliferating cell nuclear antigen (PCNA) by immunoperoxidase staining. In 12 cases, double staining for TGFalpha and Ki67 was also performed. Eighty-one percent of tumors and 94% of adjacent liver sections contained TGFalpha. A trend toward inverse correlation was seen between the percentage of TGFalpha-positive tumor cells and the proliferative rate as determined by Ki67 staining. No clear correlation of TGFalpha to either tumor stage or percentage of PCNA-positive cells was seen. This study confirms the presence of TGFalpha in the majority of early- and late-stage HCC. Positivity within tumor tissue is consistent with autocrine or paracrine stimulation. A trend toward inverse correlation between TGFalpha-producing cells and the number of cycling cells suggests that rapidly proliferating tumors may consume this growth factor at an accelerated rate. Alternatively, other hepatic mitogens may have more functional significance in these latter tumors. Finally, the presence of TGFalpha in peritumoral hepatocytes suggests these cells as potential sources of paracrine stimulation for HCC.

Liver resection for hilar and peripheral cholangiocarcinomas: a study of 62 cases

OBJECTIVE

To analyze a single center's 14-year experience with 62 consecutive patients with hilar (HCCA) and peripheral (PCCA) cholangiocarcinomas.

SUMMARY BACKGROUND DATA

Long-term survival after surgical treatment of HCCA and PCCA has been poor.

METHODS

From March 1981 until December 1994, 62 consecutive patients with HCCA (n = 28) and PCCA (n = 34) underwent surgical treatment. The operations were individualized and included local excision of the tumor and suprapancreatic bile duct, lymph node dissection, vascular reconstruction, and subtotal hepatectomy. Clinical and pathologic risk factors were examined for prognostic influence.

RESULTS

Patients were followed for a median of 25 months (12-102 months). Postoperative morbidity and mortality (at 30 days) were 32% and 14%, respectively, for HCCA and 24% and 6% for PCCA. The survival rates for HCCA and PCCA were 79% (+/-8%) and 67% (+/-8%) at 1 year; 39% (+/-10%) and 40% (+/-9%) at 3 years; and 8% (+/-7%) and 35% (+/-10%) at 5 years, respectively. The median survival was 24 (+/-4) months for HCCA and 19 (+/-8) months for PCCA. The disease-free survival rates for HCCA and PCCA were 85% (+/-10%) and 77% (+/-9%) at 1 year; 18% (+/-11%) and 41% (+/-12%) at 3 years; and 18% (+/-11%) and 41% (+/-12%) at 5 years, respectively. Nearly 80% of these patients had TNM stage IV tumors. With HCCA, no risk factors were associated with patient survival. For PCCA, multiple tumors (relative risk [RR] = 3.5; 95% confidence interval [CI] = 1.2-10.5) and incomplete resection (RR = 8.3; 95% CI = 2.3-29.6) were independently associated with a worse prognosis. For HCCA, there was a trend for lower disease-free survival in females (p = 0.056; log rank test). For PCCA, tumor size >5 cm was the only factor associated with disease recurrence (p = 0.024; log rank test).

CONCLUSIONS

Even though rare, 5-year survival by resection can be achieved in both HCCA and PCCA, but new adjuvant treatments are clearly needed.

Chronic liver allograft rejection: a National Institute of Diabetes and Digestive and Kidney Diseases interinstitutional study analyzing the reliability of current criteria and proposal of an expanded definition. National Institute of Diabetes and Digestive and Kidney Diseases Liver Transplantation Database

A study was conducted to assess the inter and intrarater agreement for the histopathologic features and diagnosis of chronic rejection (CR) and several other important causes of late liver allograft dysfunction. On two occasions, five pathologists, experienced with liver transplantation, reviewed a set of 49 slides representing a range of diagnoses, without knowledge of the clinical history or liver injury test results. The readings were correlated with the original histopathologic diagnosis, liver injury tests, and clinicopathologic follow-up. Assessment of biopsy adequacy (kappa = 0.69) and portal tract counts (kappa = 0.79) showed good to excellent intrarater agreement, whereas interrater agreement for these variables was moderate to good, respectively (kappa = 0.44 and 0.65). Likewise, the intrarater agreement for the diagnosis of CR (kappa = 0.68), hepatitis (kappa = 0.77), and obstructive cholangiopathy (kappa = 0.55) showed good to excellent agreement, whereas the interrater agreement for these same diagnoses ranged from fair to good (kappa = 0.58, 0.46, and 0.25, respectively). In 18 specimens, there was a near unanimous diagnosis of CR across both readings. These biopsies were obtained at a median of 7.1 months (range, 42 days to 4.9 years) after transplantation, and the average number of portal tracts was 8.4 (range, 4-15). Interestingly, only 13 of these 18 specimens showed bile duct loss in >50% of the portal triads; the remaining cases showed atrophy/pyknosis of the biliary epithelium in a majority of small bile ducts. Clinicopathologic correlation showed that these 18 biopsies were obtained from 16 grafts from 15 patients, 14 of whom ultimately required retransplantation or died of or with CR, whereas two of the grafts/patients recovered. A high rate of sensitivity (92%) and a somewhat lower, but acceptable, rate of specificity (71% to 80%) was found for the diagnosis of CR. Chronic rejection and other causes of late liver allograft dysfunction can be diagnosed reliably by a group of pathologists experienced with liver transplantation, and the diagnosis of CR correlates with clinical course and liver function abnormalities. Expanded criteria for the diagnosis of CR are presented, and potential problem areas for practicing pathologists are discussed.

Large cell change (liver cell dysplasia) and hepatocellular carcinoma in cirrhosis: matched case-control study, pathological analysis, and pathogenetic hypothesis

Large cell change (LCC), characterized by cellular enlargement, nuclear pleomorphism and hyperchromasia, and multinucleation of hepatocytes, is a common lesion in cirrhotic livers, but its nature, significance, and pathogenesis remain uncertain. Therefore, we assessed the prognostic value of LCC as a marker of subsequent hepatocellular carcinoma (HCC) through a case-control study that compared pretransplant liver biopsy specimens from 37 cirrhotic liver transplant recipients with HCC to specimens from a control group of recipients without HCC, matched for sex, age (+/-5 years), and cause of cirrhosis. LCC was identified in 16 (43%) of the study and 7 (19%) of the control group biopsy specimens. By matched-pair analysis, LCC conveyed a moderately increased risk of later HCC with an estimated odds ratio of 3.3 (95% CI, 1.2-15; P = .038). However, a pathology review of 45 HCCs showed adjoining LCC in only 12 (27%) and did not suggest a morphological transition or a histogenetic association between the two lesions. LCC hepatocytes displayed a low proliferative rate by Ki-67 or proliferating cell nuclear antigen immunostaining (labeling indices of 0.27 and 0.73) but showed a greater degree of apoptosis than normal hepatocytes (labeling indices of 1.9 and 0.23; P = .03) To reconcile these findings, we propose that LCC derives from derangements in the hepatocyte's normal process of polyploidization. Such derangements, possibly caused by chronic inflammation-induced DNA damage, could yield a population of enlarged liver cells with nuclear atypia and pleomorphism, frequent binuclearity, and minimal proliferation. According to this hypothesis, LCC would be a habitual feature of cirrhosis and a regular accompaniment of HCC but would not represent a direct malignant precursor.

Adenovirus hepatitis in the adult allograft liver

BACKGROUND

Adenovirus hepatitis in the allograft liver is an uncommon condition hitherto recognized only in pediatric patients. We describe two adult cases.

METHODS

Clinical information was obtained by reviewing the medical records. The diagnosis of adenoviral infection was made by immunohistochemistry or culture.

RESULTS

Both patients had received recent antirejection treatment and presented with fever, hepatic dysfunction, and progressive leukopenia. One patient had some viral inclusions resembling those described in herpes simplex infections. Adenovirus was cultured from the liver in both cases and from the lung in one case. Both patients were treated by decreasing the immunosuppression and intravenous acyclovir, but died.

CONCLUSIONS

Adenovirus infection should be considered when evaluating adult liver transplant patients with necrotizing lesions or microabscess formation at allograft biopsy. A review of the literature shows that most previously reported infections have led to graft loss or death, but occasional remissions of disease are also on record.

Survival and quality of life after liver transplantation for acute alcoholic hepatitis

The applicability of liver transplantation for ALD remains limited because of ethical arguments and also because of the perception of poor outcome after transplantation. Patients with alcoholic cirrhosis are known to do as well as patients with nonalcoholic liver disease after receiving liver allografts; however, the outcome in patients with severe acute alcoholic hepatitis in this setting is unclear. We studied 9 liver transplant recipients in whom severe acute alcoholic hepatitis was retrospectively diagnosed; 8 had underlying cirrhosis, and 1 had advanced fibrosis. All had Maddrey's discriminant function > 32, and most had hepatic encephalopathy and hepatorenal syndrome. History regarding abstinence was unreliable in some patients. Episodes of acute cellular rejection responded quickly to therapy, and despite recidivism in some patients, long-term survival was comparable to that of patients receiving transplants with alcoholic cirrhosis alone and those with a milder degree of alcoholic hepatitis and cirrhosis. This study suggests that severe acute alcoholic hepatitis may not be an appropriate contraindication for liver transplantation.

Hepatic resection and transplantation for peripheral cholangiocarcinoma

BACKGROUND

Recent publications have questioned the role of orthotopic liver transplantation (OLT) in treating advanced or unresectable peripheral cholangiocarcinoma (Ch-Ca).

STUDY DESIGN

We reviewed our experience with Ch-Ca to determine survival rates, recurrence patterns, and risk factors in 54 patients who underwent either hepatic resection or OLT between 1981 and 1994. Liver transplantation was performed in patients with unresectable tumors (n = 12) and in those with advanced cirrhosis (n = 8). There were 33 women (61%) and 21 men (39%), with a mean age of 54.3 years. The median followup period was 6.8 years. Prognostic risk factors were analyzed by univariate and multivariate analyses.

RESULTS

Mortality within 30 days was 7.4%. Overall patient and tumor-free survival rates were 64% and 57% at 1 year, 34% and 34% at 3 years, and 26% and 27% at 5 years after operation. Thirty-two patients (59.3%) experienced tumor recurrence. Univariate analysis revealed that multiple tumors, bilobar tumor distribution, regional lymph node involvement, presence of metastasis, positive surgical margins, and advanced pTNM stages were significant negative predictors of both tumor-free and patient survival. Multivariate analysis revealed that positive margins, multiple tumors, and lymph node involvement were independently associated with poor prognosis. When patients with these three negative predictors were excluded, the patient survivals at 1, 3, and 5 years were 74%, 64%, and 62%, respectively.

CONCLUSIONS

Both hepatic resection and OLT are effective therapies for Ch-Ca when the tumor can be removed with adequate margins, the lesion is singular, and lymph nodes are not involved.

Hepatic resection and transplantation for peripheral cholangiocarcinoma

BACKGROUND

Recent publications have questioned the role of orthotopic liver transplantation (OLT) in treating advanced or unresectable peripheral cholangiocarcinoma (Ch-Ca).

STUDY DESIGN

We reviewed our experience with Ch-Ca to determine survival rates, recurrence patterns, and risk factors in 54 patients who underwent either hepatic resection or OLT between 1981 and 1994. Liver transplantation was performed in patients with unresectable tumors (n = 12) and in those with advanced cirrhosis (n = 8). There were 33 women (61%) and 21 men (39%), with a mean age of 54.3 years. The median followup period was 6.8 years. Prognostic risk factors were analyzed by univariate and multivariate analyses.

RESULTS

Mortality within 30 days was 7.4%. Overall patient and tumor-free survival rates were 64% and 57% at 1 year, 34% and 34% at 3 years, and 26% and 27% at 5 years after operation. Thirty-two patients (59.3%) experienced tumor recurrence. Univariate analysis revealed that multiple tumors, bilobar tumor distribution, regional lymph node involvement, presence of metastasis, positive surgical margins, and advanced pTNM stages were significant negative predictors of both tumor-free and patient survival. Multivariate analysis revealed that positive margins, multiple tumors, and lymph node involvement were independently associated with poor prognosis. When patients with these three negative predictors were excluded, the patient survivals at 1, 3, and 5 years were 74%, 64%, and 62%, respectively.

CONCLUSIONS

Both hepatic resection and OLT are effective therapies for Ch-Ca when the tumor can be removed with adequate margins, the lesion is singular, and lymph nodes are not involved.

Treatment of fibrolamellar hepatoma with subtotal hepatectomy or transplantation

Fibrolamellar hepatoma (FL-HCC) is an uncommon variant of hepatocellular carcinoma (HCC), distinguished by histopathological features suggesting greater differentiation than conventional HCC. However, the optimal treatment and the prognosis of FL-HCC have been controversial. Follow-up studies are available from 1 year to 27 years, after 41 patients with FL-HCC were treated with partial hepatectomy (PHx) (28 patients) or liver transplantation (13 patients). In this retrospective study, the effect on outcome was determined for the pTNM stage and other prognostic factors routinely recorded at the time of surgery. Cumulative survival at 1, 3, 5, and 10 years was 97.6%, 72.3%, 66.2%, and 47.4%. Tumor-free survival at these times was 80.3%, 49.4%, 33%, and 29.3%. The TNM stage was significantly associated with tumor-free survival. Patients with positive nodes had a shorter tumor-free survival than those with negative nodes (P < .015). Patient survival was most adversely affected by the presence of vascular invasion (P < .05). FL-HCC is an indolently growing tumor of the liver, which usually was diagnosed in our patients at a stage too advanced for effective surgical treatment of most conventional HCC. Nevertheless, long-term survival frequently was achieved with aggressive surgical treatment. When a subtotal hepatectomy could not be performed, total hepatectomy (THx) with liver transplantation was a valuable option.

Central venulitis in the allograft liver: a clinicopathologic study

BACKGROUND

Central venulitis denotes a histologic lesion of the allograft liver characterized by perivenular and subendothelial mononuclear inflammation of the terminal hepatic venules associated with varying degrees of perivenular hepatocyte dropout. Although this lesion has generally been considered a manifestation of acute rejection, some have suggested that it instead represents tacrolimus hepatotoxicity.

METHODS

We therefore compared the clinicopathologic features of 30 episodes of isolated central venulitis with 22 episodes of combined central venulitis and typical portal acute rejection occurring in 27 patients. Nineteen of the patients received tacrolimus and eight received cyclosporine as primary immunosuppression.

RESULTS

No significant differences were found between the two groups, except that isolated central venulitis more often displayed a mild inflammatory component (P=0.007) with small lymphocytes as the predominant cell type (P=0.002). None of the patients had tacrolimus or cyclosporine levels that exceeded the therapeutic range, and none had other clinical evidence of drug toxicity. Usual antirejection therapy was instituted in all but two episodes; response was evident in 93% (28 of 30) of the isolated central venulitis and 86% (19 of 22) of the central venulitis-portal acute rejection group, with histologic regression documented in all follow-up specimens (four and five, respectively). Due to persistent central venulitis, two cyclosporine patients were switched to tacrolimus, with prompt resolution.

CONCLUSIONS

These findings are inconsistent with the concept that central venulitis represents drug toxicity and indicate instead that it is a form of acute allograft rejection.

Intrahepatic cholestasis due to systemic mastocytosis: a case report and review of literature

A 35-yr-old female presented with symptoms of obstructive jaundice. Liver biopsy, bone marrow aspiration, and biopsy revealed systemic mastocytosis and acute myeloid leukemia. The liver biopsy specimen showed infiltration of mast cells within portal tracts with periductal and portal edema, irregularity of interlobular duct epithelium, and centrizonal cholestasis. Endoscopic retrograde cholangiography was normal. Following chemotherapy treatment with idarubicin and cytarabine for seven days for AML, the bilirubin levels continued to increase for two weeks and then decreased, reaching normal levels in two months. Infiltration of mast cells in the liver leads to hepatomegaly, liver function abnormality and rarely portal hypertension. Intrahepatic cholestasis due to systemic mastocytosis has never been reported. We report a rare case of systemic mastocytosis causing intrahepatic cholestasis that resolved with remission of AML following chemotherapy.

Utilization of hepatocyte-specific antibody in the immunocytochemical evaluation of liver tumors

A monoclonal antibody highly specific for benign and malignant hepatocytes (HepPar 1) was evaluated as part of an antibody panel used to differentiate hepatocellular from nonhepatocellular neoplasms. Sixty-five liver tumors and two extrahepatic tumors from patients with documented liver tumors were studied. Twenty-two neoplasms were of hepatocellular origin, three were combined hepatocellular/cholangiocarcinomas, and the remainder were of nonhepatocellular origin. HepPar 1 alone had an 82% sensitivity and 90% specificity for the detection of hepatocellular neoplasms. The corresponding values for alpha-fetoprotein were 57% and 97%. Polyclonal antibody to carcinoembryonic antigen (canalicular pattern) had a sensitivity of 79% and specificity of 97% for these tumors. The use of antibody panels provided superior results when compared with individual antibodies. In summary, HepPar 1 monoclonal antibody is a useful reagent for the differential diagnosis of hepatocellular tumors. Its utility is enhanced when it is used as part of a diagnostic antibody panel.

Prognostic factors and management of carcinomas of the gallbladder and extrahepatic bile ducts

Cancers of the biliary tract are uncommon but aggressive malignancies that pose difficult problems in diagnosis and management. Long-term survival with these cancers is limited by their propensity for local invasion, so that pathologic stage becomes a major prognostic factor, and by their ability to cause biliary obstruction and sepsis and interfere with hepatic function. In selected patients, surgical resection offers the possibility of cure, but effective palliation is often the principal goal of treatment. Radiologic and endoscopic modalities thus often play a major role in patient management.

Hepatic epithelioid hemangioendothelioma: biological questions based on pattern of recurrence in an allograft and tumor immunophenotype

Epithelioid hemangioendothelioma (EHE) is best considered a vascular neoplasm of intermediate malignancy. Although usually progressive, the clinical course is highly unpredictable. The present communication describes a case of extensive recurrent hepatic EHE, limited to the liver allograft and initially manifest as an insidious seeding of individual tumor cells in areas of perivenular inflammation associated with rejection. A detailed immunophenotypic characterization of this and a small series of EHE was carried out in an effort to highlight subtle disease recurrence and to gain possible insights into tumor biology associated with this intriguing disease. In a series of five cases of hepatic EHE, CD34 (QB-END/10) was found to be more sensitive than Factor VIII (F-VIII) for recognition of the disease, similar to previous reports. The former diffusely and distinctly stained both epithelioid and dendritic tumor cells, whereas staining for the latter was focal, indistinct, and showed a high background. Although the tumor cells were negative for some markers of dendritic or macrophage maturation, such as CD1a, S100 protein, Mac 387, CD68, and LN3, there was marked infiltration of hepatic EHE by factor XIIIa + (F-XIIIa), Mac 387+, CD68+, and LN3+ macrophages and dendrocytes, most of which were interpreted as reactive. The "reactive" macrophage and dendrocyte populations were present throughout the fibrotic stroma and intermingled with the epithelioid clusters of EHE. Interestingly, a small subset of tumor cells coexpressed CD34 or F-VIII and F-XIIIa, the last of which is normally restricted to cells of the monocyte/macrophage lineage and cytokine activated microvascular endothelium in vitro. The known association of F-XIIIa+ dendrocytes with granulation tissue, repair and fibrogenesis, and the modulation of F-XIIIa and F-VIII expression by inflammatory cytokines led us to speculate that EHE lesions may derive from primitive "reticuloenothelial" cells that can differentiate along endothelial and dendritic pathways. The EHE lesions may represent a neoplastic analogue of wound healing. Thus, the variability in F-VIII staining, the strong expression of CD34, the infiltration of EHE lesions with F-XIIIa+ dendrocytes, and the coexpression of CD34 and F-XIIIa on a subset of tumor cells may have an important biological basis.

A case series of transplant recipients who despite immunosuppression developed inflammatory bowel disease

OBJECTIVES

We describe 14 patients who developed inflammatory bowel disease (IBD) after transplantation despite immunosuppression.

METHODS

Using an electronic medical archival retrieval system, records of 6800 liver and kidney transplant patients were searched for evidence of IBD. The pathology was reviewed, and infectious etiologies were excluded.

RESULTS

Fourteen patients developed IBD after transplantation. Twelve patients had undergone liver transplantation, and two kidney transplantation. Four had transplantation for autoimmune hepatitis; four for non-A, non-B, non-C hepatitis; two for primary sclerosing cholangitis; one for giant cell hepatitis; one for biliary atresia; one for polycystic kidney disease; and one for obstructive uropathy. Mean age at development of IBD was 38 yr. Mean time to development of IBD after transplantation was 4 yr. Endoscopically there were two cases limited to the left side, eight of pancolitis, of which one had terminal ileal disease, and four of patchy colitis. Histology was consistent with ulcerative colitis in nine patients and Crohn's disease in five. Patients with ulcerative colitis either responded and remained in remission on maintenance therapy (seven of nine) or were refractory and required a colectomy (two of nine). Patients with Crohn's disease continued to have flares despite treatment (five of five).

CONCLUSION

1) New onset IBD can develop after solid organ transplantation, despite use of immunosuppressive therapy. 2) A full spectrum of IBD can be seen after transplantation. 3) Study of these patients could shed light on why immunosuppression is not uniformly effective for IBD and provide clues to the inflammatory determinants of IBD.

Comparison of various lazaroid compounds for protection against ischemic liver injury

Lazaroids are a group of 21 -aminosteroids that lack steroid action but have a potent cytoprotective effect by inhibiting iron-dependent lipid peroxidation. However, there have been conflicting reports on the effectiveness and potency of the various lazaroid compounds. In this study, we compared the effectiveness of three major lazaroids on warm liver ischemia in dogs using a 2-hr hepatic vascular exclusion model. The agents were given to the animals intravenously for 30 min before ischemia. The animals were divided into 5 groups: Control (n=10), no treatment; Group F (n=6), U-74006F (10 mg/kg); Group G (n=6), U-74389G (10 mg/kg); Group A1 (n=6), U-74500A (10 mg/kg); Group A2 (n=6), U-74500A (5 mg/kg). The effect of treatment was evaluated by two-week animal survival, hepatic tissue blood flow, liver function tests, blood and tissue biochemistry, and histological analyses. Animal survival in all treated groups was significantly improved compared with the control (83–100% versus 30%). Elevation of liver enzymes after reperfusion was markedly attenuated in treated groups, except for an early significant increase in Group G. Postreperfusion hepatic tissue blood flow was much higher in all treated animals (50% of the preischemic level vs. 25% in the control). Lazaroids, particularly U-74500A at 5 mg/kg (Group A2), suppressed adenine nucleotide degradation during ischemia and enhanced the resynthe-sis of high-energy phosphates after reperfusion. Although structural abnormalities in postreperfusion liver tissues were markedly ameliorated in all treated groups, Group A2 showed significantly less neutrophil infiltration. Liver injury from warm ischemia and reperfusion was attenuated with all lazaroid compounds, of which U-74500A at 5 mg/kg exhibited the most significant protective activity.