The human S mu bp-2, a DNA-binding protein specific to the single-stranded guanine-rich sequence related to the immunoglobulin mu chain switch region

We have cloned the cDNA encoding the human homologue of S mu bp-2, which binds to single-stranded DNA with 5'-phosphorylated guanine-rich sequences related to the immunoglobulin mu chain switch (S mu) region. The deduced amino acid sequences of the mouse and human S mu bp-2 are 76.5% homologous and contain motifs conserved among helicases. We have identified a domain essential for DNA binding at residues 638-786. The binding domain is less conserved (63% homologous) than the putative catalytic domain of N-terminal half containing most of the helicase motifs (85% homologous). The human and mouse S mu bp-2 have similar, although slightly different, binding specificities. Although the mouse S mu bp-2 preferentially binds to the mouse S mu motif (GGGGT), the human S mu bp-2 binds equally well to the human (GGGCT) and mouse S mu motifs. The human S mu bp-2 gene was mapped to chromosome 11 q13.2-q13.4 by in situ hybridization.

Plasma amino acid profile in relation to arterial ketone body ratio in surgical patients

A total of 357 plasma amino acid profiles from 93 surgical patients were statistically analyzed in relation to the changes in arterial ketone body ratio, which reflects the hepatic mitochondrial redox state. When the arterial ketone body ratio was above 0.7, all plasma amino acid levels were within the normal range. When it was between 0.7 and 0.4, plasma levels of aspartate, glutamate, valine, isoleucine, leucine, ornithine, and arginine decreased, and plasma levels of tyrosine, phenylalanine, proline, and methionine increased. Furthermore, when it was below 0.4, almost all plasma amino acids markedly increased. These results indicate that arterial ketone body ratio accurately reflects the alterations in plasma amino acid profile, and can serve as an indicator for providing nutritional support by amino acid supplement in surgical patients.

Effect of dobutamine on the arterial ketone body ratio and portal blood flow velocity in cirrhosis

We studied the relationship between the portal blood flow velocity and the arterial ketone body ratio in patients with chronic liver disease receiving a dobutamine infusion. We used an ultrasonic Doppler duplex system to evaluate the portal blood flow velocity. Dobutamine was given intravenously at 5 micrograms/kg/min for 20 min. Dobutamine infusion induced smaller changes in the portal blood flow velocity and ketone body ratio in liver cirrhosis than in chronic hepatitis. The existence of shunts and the poor increase of the cardiac index in response to dobutamine explained the limited improvement of portal blood flow velocity in cirrhosis patients. The ketone body ratio was improved by dobutamine in cirrhosis patients whose portal blood flow velocity was increased by more than 10%, while this ratio decreased when the increase of it was less than 10%. There was no change in portal oxygen extraction in the cirrhosis group, and portal oxygen uptake only increased when the portal blood flow velocity rose by more than 10%. Dobutamine should only be used to treat liver failure if the portal blood flow velocity is increased by more than 10% or the arterial ketone body ratio is improved by a test infusion.

Mapping of the 70 kDa, 34 kDa, and 11 kDa subunit genes of the human multimeric single-stranded DNA binding protein (hSSB/RPA) to chromosome bands 17p13, 1p35-p36.1, and 7p21-p22

Human single-stranded DNA binding protein (hSSB/RPA) is a multimeric single-stranded DNA binding protein consisting of three subunits of 70 kDa, 34 kDa, and 11 kDa. Human SSB was isolated from HeLa cells as an essential factor for the in vitro replication of simian virus 40 DNA. We and others have isolated and sequenced cDNAs for each subunit of the SSB. The chromosome on which each gene is located was determined through the analysis of a panel of human/hamster somatic cell hybrids using the polymerase chain reaction with pairs of synthetic oligonucleotide primers from the 3'-untranslated sequences of the genes. Genomic clones for each gene were isolated from a genomic cosmid library prepared from human lymphoblastoid cells. Using those clones as probes, we have carried out fluorescence in situ hybridization to human metaphase chromosomes and have mapped the 70 kDa subunit gene to 17p13, the 34 kDa subunit gene to 1p35-p36.1, and the 11 kDa subunit gene to 7p21-p22. Since hSSB participates in replication, recombination and repair of DNA, the physical mapping of hSSB genes may aid in the identification of human hereditary diseases associated with aberrant DNA reactions caused by genetic alterations of the hSSB.

Human Jk recombination signal binding protein gene (IGKJRB): comparison with its mouse homologue

The mouse Igkjrb protein specifically binds to the immunoglobulin Jk recombination signal sequence. The IGKJRB gene is highly conserved among many species such as human, Xenopus, and Drosophila. Using cDNA fragments of the mouse Igkjrb gene, we isolated its human counterpart, IGKJRB. The human genome contains one functional IGKJRB gene and two types of processed pseudogenes. In situ chromosome hybridization analysis demonstrated that the functional gene is localized at chromosome 3q25, and the pseudogenes (IGKJRBP1 and IGKJRBP2, respectively) are located at chromosomes 9p13 and 9q13. The functional gene is composed of 13 exons spanning at least 67 kb. Three types of cDNA with different 5' sequences were isolated by rapid amplification of cDNA ends, suggesting, the presence of three proteins. The aPCR-1 protein, which possessed the exon 1 sequence, was the counterpart of the mouse RBP-2 type protein. The aPCR-2 and 3 proteins may be specific to human cells because the mouse counterparts were not detected. The amino acid sequences of the human and mouse IGKJRB genes were 98% homologous in exons 2-11, whereas the homology of the human and mouse exon 1 sequences was 75%.

The effects of cold preservation on steatotic graft viability in rat liver transplantation

Clinical experience suggests that grafts obtained from steatotic livers result in primary nonfunction more frequently than those from nonsteatotic livers. To date, however, only a few studies have been done to verify the accuracy of this observation. To investigate the effects of cold preservation on steatotic liver viability, liver grafts obtained from rats fed with a choline-deficient diet were transplanted after periods of cold preservation. Recipient survival rates with normal liver grafts were 8/8 (100%) and those with steatotic liver grafts were 7/8 (88%) (P > 0.05) after 1-hr preservation with UW solution. After 9-hr preservation, however, these rates decreased significantly to 0/8 (0%) with steatotic grafts (P < 0.01), but were not significantly decreased with normal grafts. LDH levels in the effluent at the time of transplantation were 133 IU/L (1-hr) and 512 IU/L (9-hr) in normal livers, but in steatotic livers these were elevated to 598 and 3141 IU/L, respectively (P < 0.01). Recovery rates of hepatic blood flow measured by laser Doppler flowmeter after revascularization were 99% (1-hr) and 96% (9-hr) in normal grafts, but in steatotic grafts they were 98% (1-hr) and 63% (9-hr, P < 0.01). In addition, the oxidative phosphorylation ability of liver mitochondria obtained from steatotic grafts was decreased significantly after cold preservation. The present results suggest that steatotic liver grafts are prone to lose their viability more easily than normal liver grafts after prolonged periods of cold preservation due to a combination of causes.

Lipid metabolism after liver transplantation from a living related donor

1. The recovery of lipid metabolism was investigated in paediatric patients treated for terminal liver disease by liver transplantation from living related donors. 2. The cholesterol ester ratio (esterified cholesterol/total cholesterol) and the total cholesterol/phospholipid ratio increased from preoperative values of 0.35 +/- 0.04 and 0.59 +/- 0.03 to 0.65 +/- 0.01 and 0.68 +/- 0.01 at 3 weeks after liver transplantation in successful cases (means +/- SEM, n = 26), respectively, whereas these two parameters decreased in failed cases (n = 4). 3. Biochemical analysis indicated that weekly recoveries in the cholesterol ester ratio and the total cholesterol/phospholipid ratio are characteristic of successful liver transplantation with a graft from a living related donor.

An assessment of percutaneous transhepatic biliary drainage in the correction of the metabolic capacity of the jaundiced liver by hippurate-synthesizing test

Hippurate-synthesizing ability was investigated in patients with jaundice with percutaneous transhepatic biliary drainage (PTBD) in relation to hepatic metabolic capacity. In 16 patients with PTBD because of obstructive jaundice and 11 patients without hepatic disease, 1.77 grams of sodium benzoate was injected and the amount of hippurate synthesized and excreted in the urine collected at 30, 60, 120 and 180 minutes was measured (hippurate test). In patients with jaundice and patients in the control group, an almost linear increase was observed in the level of urinary hippurate after benzoate loading. However, the values of the patients with jaundice at one and two hours after the benzoate loading were significantly lower than those of the patients in the control group. Serum levels of glutamate oxaloacetic transaminase, glutamate pyruvate transaminase, alkaline phosphatase, gamma-glutamyl transpeptidase, total bilirubin and direct bilirubin were significantly decreased during PTBD (p < 0.05). Bilirubin levels were closely correlated with hippurate test values (r = 0.567, p < 0.05). Values were also correlated with the period of PTBD before the hippurate test was performed (r = 0.632, p < 0.05). Recovery in hippurate synthesizing ability was observed when the total bilirubin levels decreased to less than 5 milligrams per deciliter or PTBD was maintained for more than three weeks. Because hippurate synthesis is dependent on adenosine triphosphate supply in the hepatic mitochondria, the value of the hippurate test reflects the metabolic viability of the liver in relation to energy metabolism. It is also suggested that the steady maintenance of PTBD for three weeks or more with a decrease in total bilirubin level less than 5 milligrams per deciliter is necessary for full recovery of the metabolic capacity of the jaundiced liver.

Hepatic cholesterol and bile acid synthesis in Japanese patients with cholesterol gallstones

In Japan the composition of gallstones is changing rapidly from the once-predominant brown-pigment stones to cholesterol ones. The present work was undertaken to clarify the mechanism of cholesterol supersaturated bile production in Japanese patients with cholesterol gallstones. In 26 non-obese and normolipidemic patients (11 with cholesterol gallstones, 8 with black- or brown-pigment gallstones, 7 without gallstones) a liver biopsy and hepatic bile were surgically obtained under standardized conditions. The cholesterol saturation of hepatic bile was significantly higher in cholesterol gallstone patients than in gallstone-free controls (195 +/- 10 vs. 146 +/- 8%, respectively; P < 0.01). The microsomal activities of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, the rate-limiting enzyme for cholesterol synthesis, cholesterol 7 alpha-hydroxylase, the rate-limiting enzyme for bile acid synthesis, and 7 alpha-hydroxy-4-cholesten-3-one 12 alpha-hydroxylase (12 alpha-hydroxylase), the rate-limiting enzyme for cholic acid synthesis, were assayed simultaneously in the same subjects. There were positive correlations between HMG-CoA reductase and cholesterol 7 alpha-hydroxylase activities (Rs = 0.62, P < 0.005), and between cholesterol 7 alpha-hydroxylase and 12 alpha-hydroxylase activities (Rs = 0.44, P < 0.05) in all subjects, irrespective of the existence of gallstones. The activities of the three rate-limiting enzymes did not differ significantly among the three groups (cholesterol stone, pigment stone and stone-free). In conclusion, the cholesterol supersaturation of hepatic bile in nonobese and normolipidemic Japanese patients with cholesterol gallstones does not result from an increased hepatic cholesterol synthesis or a decreased bile acid synthesis.

Increased deposition and serum level of type IV collagen in patients with extrahepatic biliary atresia

Increased deposition of fibrous connective tissue has been demonstrated in extrahepatic biliary atresia (EHBA). We have focused on type IV collagen, a major component of the perisinusoidal wall of the liver. We attempted to localize tyep IV collagen in liver specimens with monoclonal antibodies. Ultrastructural changes of the liver were observed by electronmicroscopy. Serum amount of type IV collagen was estimated by a recently developed sandwich enzyme immunoassay (EIA) method. Serum laminin and prolyl 4-hydroxylase were also determined by EIA for comparison with type IV collagen. Increased deposition of type IV collagen in the perisinusoidal wall was evident in the area with so-called sinusoidal capillarization. Electronmicroscopy showed a basement membrane structure underlying the endothelial cells in Disse's space. Serum type IV collagen increased in EHBA patients before living-related liver transplantation (LRLT), and returned to normal within 5 weeks after LRLT, except for some patients with postoperative complications. Serum laminin and prolyl 4-hydroxylase showed the same propensity, although less prominently so. It is suggested that the immunoassay of serum type IV collagen adopted in this study has potential application in estimating collagen synthetic activity of the liver and in monitoring the postoperative states of patients after LRLT.

Effects of triiodothyronine on canine hepatic ischemia caused by Pringle's maneuver

BACKGROUND

A significant reduction in the serum concentration of triiodothyronine is frequently observed in surgical stress and may influence the severity and prognosis of the underlying disease.

METHODS

Alterations of thyroid hormone levels and effects of triiodothyronine were evaluated in the shock state after Pringle's maneuver for 60 minutes in dogs. Triiodothyronine (1 micrograms/kg/hr) was infused intravenously for 3 hours after declamping in the triiodothyronine-treated group. The effect of triiodothyronine on hepatic mitochondrial function was investigated by measuring the arterial ketone body ratio (AKBR).

RESULTS

In the control group (n = 6) the low triiodothyronine syndrome was observed and progressive deterioration of AKBR and standard liver functions represented by aspartate aminotransferase, glutamic-pyruvic transaminase, and lactic dehydrogenase were noted after declamping. All dogs went into shock and died within 24 hours. By contrast, in the triiodothyronine-treated group (n = 6), hemodynamics were stabilized and standard liver functions were maintained favorably (p < 0.01). AKBR was fully restored to the preischemic liver within 30 minutes after declamping, with a decrease in serum lactate levels (p < 0.05). All dogs survived at least 7 days after operation (p < 0.01).

CONCLUSIONS

These results indicate that triiodothyronine has beneficial effects on cytoprotection, hemodynamics, and hepatic energy metabolism in the ischemic liver injury. Furthermore, it improves survival in the shock state after Pringle's maneuver.

Transcatheter hepatic arterial drug infusion therapy for hepatocellular carcinoma. Effect on the arterial ketone body ratio

The arterial ketone body ratio (acetoacetate to beta-hydroxybutyrate) was measured in 15 patients with chronic liver disease before and after the infusion of anticancer drugs or embolic agents (gelatin sponge or iodized oil) into the hepatic artery. The arterial ketone body ratio decreased after hepatic angiography and decreased further at 15 min after infusion therapy. When the arterial ketone body ratio decreased to 1.0 or less on at least one occasion after infusion therapy, the ratio after hepatic angiography was always 1.35 or less. Such patients developed marked systemic symptoms like fever and severe liver dysfunction. Ascites also developed in three patients in whom the arterial ketone body ratio was reduced to 0.7 or less at 24 h after infusion therapy. The arterial ketone body ratios improved at 3-7 days after infusion therapy. In the seven patients treated with gelatin sponge embolization, the ratio at 3-7 days after therapy was actually higher than that before angiography.

Increased arterial ketone body ratio as a prerequisite for recovery after hepatectomy

It is reported that a prompt increase in the arterial ketone body ratio (acetoacetate/beta-hydroxybutyrate), which reflects the mitochondrial redox state of the liver graft, is a decisive prerequisite for graft survival in clinical liver transplantation. To contrast the rôle of hepatic mitochondrial redox state in partial hepatectomy with that in hepatic replacement, the changes in the ketone body ratio were investigated in 107 cases of hepatectomy. The ketone body ratio in uneventful cases (n = 70) in the first three days after hepatectomy was significantly higher than that in eventful cases. In the uneventful cases, the ketone body ratios were all increased to above 1.0 within two days after hepatectomy, except in diabetics, whose preoperative values did not reach 1.0 under oral glucose load. However, 20 (22.7%) out of 88 cases whose ketone body ratios promptly increased after hepatectomy had mild to moderate complications thereafter. It is suggested that the recovery of hepatic mitochondrial redox state is also a prerequisite in partial hepatectomy, where a reduced and often damaged liver confronts systemic metabolic load.

Arterial ketone body ratio and glucose administration as an energy substrate in relation to changes in ketone body concentration after living-related liver transplantation in children

Changes in the arterial ketone body ratio (AKBR [acetoacetate/3-hydroxybutyrate]), which reflect the redox state of the liver mitochondria (NAD+/NADH), as well as those in total ketone body concentration (TKB) and blood glucose level were studied in 30 living-related liver transplantations (LRLT) performed in pediatric patients at Kyoto University Hospital from June 1990 to January 1992. AKBR increased to over 1.0 within 6 hr after reperfusion of the graft in 11 cases (37%), within 12 hr in 7 (23%), on POD 1 in 8 (27%), and on POD 2 in the remaining 4 cases (13%). TKB significantly increased while AKBR remained below 0.7 (266 +/- 40 mumol/L), but it significantly decreased in accordance with the recovery of AKBR above 1.0 (61 +/- 6 mumol/L). This indicates the change in the predominant energy substrate for hepatic mitochondria from fatty acid to glucose during the AKBR recovery process. In 6 cases, the AKBR transiently decreased to below 1.0 after initial recovery concomitant with the fall in blood glucose level and the increase in TKB. However, the AKBR was rapidly restored to over 1.0 again immediately after the glucose administration was increased. This suggests that glucose administration to maintain blood glucose level between 150 and 250 mg/dl is essential for the AKBR recovery above 1.0 that accompanies the normalization of graft metabolic functions, and that, along with the postoperative minimal increase in serum enzymes and favorable outcome of the transplant with no incidence of a primary nonfunctioning graft, the prompt and successful recovery of AKBR reflects the expected high viability of the graft in our LRLT cases.

Enzyme immunoassay of liver-type arginase and its potential clinical application

We developed an efficient enzyme-linked immunosorbent assay (ELISA) system for measurement of human liver-type arginase in serum. A conjugate of the Fab' fragment of anti-human liver (recombinant) arginase IgG and horseradish peroxidase was used as the second antibody. This assay is highly specific, sensitive, and reproducible, enabling us to detect arginase at concentrations as low as several micrograms per liter without any prior processing of serum. The reaction is linear up to 200 micrograms/L. The arginase concentration in serum, as determined by this method, increased markedly and temporarily at the time of surgical operation or later injury to the liver. The increase was accompanied or followed by increases in serum concentrations of aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase, suggesting that the arginase emerged from damaged hepatocytes. In view of a limited tissue distribution of liver-type arginase, our ELISA system may be useful in diagnosis of various hepatic disorders as well as follow-up of postoperative conditions of patients.

MRI of soft-tissue lesions: opposed-phase T2*-weighted gradient-echo images

We evaluated the ability of opposed-phase T2*-weighted gradient-echo (T2*GE) MRI to demarcate soft tissue lesions. The series contained 37 cases, including 18 benign tumors, 8 malignant tumors, and 11 miscellaneous nonneoplastic soft-tissue lesions. Images were obtained on a 0.5 T magnet with T2*GE imaging (TR/TE 300/22 ms, 20 degrees). Results were compared with those of T1-weighted SE images (500/20-40) and T2-weighted SE (T2SE) images (2,000/80). The T2*GE images were similar to T2SE images with respect to the signal behavior and internal architecture of the masses in many cases. In some instances, they were better than T2SE images in delineating the lesions and adjacent fat tissue, in delineating the lesions and adjacent small vessels, and in depicting special features such as hemosiderin deposits. They were inferior to T2SE images in delineating the lesions and adjacent muscles. Because of reduced lesion-muscle delineation, T2*GE images can not be substituted for T2SE images in the evaluation of soft-tissue lesions, but are useful as an adjunct in some cases.

Enzyme immunoassay of liver-type arginase and its potential clinical application

We developed an efficient enzyme-linked immunosorbent assay (ELISA) system for measurement of human liver-type arginase in serum. A conjugate of the Fab' fragment of anti-human liver (recombinant) arginase IgG and horseradish peroxidase was used as the second antibody. This assay is highly specific, sensitive, and reproducible, enabling us to detect arginase at concentrations as low as several micrograms per liter without any prior processing of serum. The reaction is linear up to 200 micrograms/L. The arginase concentration in serum, as determined by this method, increased markedly and temporarily at the time of surgical operation or later injury to the liver. The increase was accompanied or followed by increases in serum concentrations of aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase, suggesting that the arginase emerged from damaged hepatocytes. In view of a limited tissue distribution of liver-type arginase, our ELISA system may be useful in diagnosis of various hepatic disorders as well as follow-up of postoperative conditions of patients.

Systematic synthesis of sulfur-containing p-nitrophenyl alpha-maltopentaoside derivatives for a differential assay of human alpha-amylases

For use in a differential assay of human alpha-amylases, a variety of 6(5)-S-substituted p-nitrophenyl alpha-maltopentaoside derivatives (6-54) were systematically synthesized via the key intermediate, p-nitrophenyl O-(2,3-di-O-acetyl-6-S-acetyl-4-O-benzoyl-6-thio-alpha-D-glucopyranosyl) - (-->4)-tris[O-(2,3,6-tri-O-acetyl-alpha-D-glucopyranosyl)-(1-->4)]-2,3,6 -tri-O-acetyl-alpha-D-glucopyranoside (4), which was easily prepared from p-nitrophenyl alpha-maltopentaoside (G5P) in four steps. The sulfoxide and sulfone derivatives were prepared by oxidizing the corresponding sulfides with m-chloroperbenzoic acid.

Simultaneous determination of mevalonate and 7 alpha-hydroxycholesterol in human plasma by gas chromatography-mass spectrometry as indices of cholesterol and bile acid biosynthesis

A very sensitive and specific method for the simultaneous determination of mevalonate and 7 alpha-hydroxycholesterol in human plasma is described. The assay is based on isotope dilution mass spectrometry: the extracts from plasma were treated with benzylamine followed by dimethylethylsilylimidazole, then the resulting dimethylethylsilyl ether derivatives of mevalonylbenzylamide and 7 alpha-hydroxycholesterol were determined by gas chromatography-mass spectrometry using high-resolution selected-ion monitoring. Simple regression analysis revealed significant correlations between the plasma level of mevalonate and the hepatic activity of 3-hydroxy-3-methylglutaryl-coenzyme A reductase (EC 1.1.1.34) (r = 0.83, P < 0.01) and between the plasma level of free 7 alpha-hydroxycholesterol and the hepatic activity of cholesterol 7 alpha-hydroxylase (EC 1.14.13.7) (r = 0.76, P < 0.05).

Decreased adenylate energy charge and superoxide anion release in polymorphonuclear leukocytes in septic patients after hepatectomy

To clarify the process of multiple organ failure after hepatectomy, the adenylate energy charge (EC) and superoxide anion (O2-) release of polymorphonuclear leukocytes (PMN) were measured 19 times on 11 septic patients after curative hepatic resection in relation to arterial ketone body ratio (AKBR), which reflects hepatic mitochondrial redox potential. PMN EC was measured by labeling the adenine nucleotide pool of PMN with radioactive adenine. The data of the septic patients (n = 19) was divided into two groups according to the hepatic energy status: AKBR above 0.7 (septic state A; n = 8) and AKBR below 0.7 for at least 3 successive days (septic state B; n = 11). Thirteen nonseptic patients undergoing hepatic resection were applied to the control group, and all of them showed AKBRs higher than 0.7. The PMN EC of septic patients was significantly lower than that of nonseptic patients [0.80 +/- 0.01 (SEM) vs. 0.88 +/- 0.02, P < 0.01]. In septic patients, moreover, the PMN EC of septic state A was significantly higher than septic state B (0.85 +/- 0.01 vs. 0.77 +/- 0.03, P < 0.05). Superoxide anion release of septic patients was significantly lower than that of nonseptic patients (19.0 +/- 2.1 nmol/5 x 10(5) cells/15 min vs. 29.3 +/- 1.7 nmol/5 x 10(5) cells/15 min, P < 0.01). Superoxide anion release of septic state A was significantly greater than that of septic state B (26.0 +/- 2.8 nmol/5 x 10(5) cells/15 min vs. 15.0 +/- 1.9 nmol/5 x 10(5) cells/15 min, P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Large epidermal cyst involving the ischiorectal fossa: MR demonstration

A large subcutaneous mass was noted in the buttock of a 79-year-old man. Computed tomography (CT) and magnetic resonance imaging (MRI) showed a thin-walled cystic mass that involved the ischiorectal fossa. The content appeared hyperintense on T1-weighted images. T2-weighted images demonstrated a considerable amount of debris. At surgery an epidermal cyst with markedly keratinized squamous epithelium was found. It contained much keratin and cholesterin.