Production of ascorbate and hydroxyl radicals in the liver of LEC rats in relation to hepatitis

The production of radicals was examined in vitro in liver supernatant prepared from LEC rats of different ages before and after the onset of jaundice. Each liver supernatant was subjected to heat-treatment at 90 degrees C for 10 min to remove heat-labile proteins, and then the production of radicals in the resultant supernatant in the presence of hydrogen peroxide and 5,5'-dimethyl-1-pyrroline oxide (DMPO) was studied by ESR. Two sharp ESR signals that completely decayed with time within 5 min after the addition of hydrogen peroxide were observed for the sample prepared from LEC rats before the onset of jaundice, followed by the appearance of four signals of a hydroxyl radical-DMPO adduct after 5 min. On the other hand, in the supernatant prepared from LEC rats after the onset of jaundice, the former two signals were not observed or observed only marginally, and the signals of the hydroxyl radical-DMPO adduct showed a different pattern of decay from that for the supernatant prepared from LEC rats before the onset of jaundice. With the addition of ascorbic acid to the liver supernatant prepared from LEC rats after the onset of jaundice, the former signals of the ascorbate and hydroxyl radicals reappeared. The present results suggest that ascorbate and hydroxyl radicals are produced in the liver of LEC rats with the onset of jaundice, depending on the relative ratio of ascorbic acid and cuprous ions.

Total excision of mesenteric cysts by laparoscopic surgery: report of two cases

Mesenteric cysts are relatively rare tumors, and most patients present nonspecific abdominal symptoms until developing larger cysts. We report two cases of mesenteric cysts that were totally excised during laparoscopic surgery. The cysts of both patients were located in the mesenterium of the cecum or ascending colon. Under laparoscopy, the cyst was punctured to collect the cystic fluid for cytology and then completely removed without bowel resection. Histological examination revealed cystic lymphangiomas with endothelial cell lining. The postoperative course was uneventful. Laparoscopic treatment of benign abdominal cysts is an alternative safe and less invasive operation.

[Posterior iris bowing after accommodation--elucidation of the etiology of pigment dispersion syndrome]

Recent advancements in imaging the anterior segment structures using the ultrasound biomicro scope (UBM) have proven the involvement of posterior iris bowing due to reverse pupillary block as the cause of pigment dispersion syndrome. In this report, we examined whether the posterior iris bowing occurs even in normal eyes following accommodation, and whether the degree of iris concavity tends to be greater in myopic eyes than in emmetropic eyes. The subjects were normal eyes with sufficient accommodation power, i.e. 5 myopic eyes with less than-5 diopter reflection, 5 emmetropic eyes within +/- 1 dioptor reflection, respectively. We obtained UBM images of the iris at 4 portions before and after accommodation, and measured the degree of posterior iris bowing. We found that almost all data shift posteriorly after accommodation, and that the iris concavity is more distinct in myopic eyes than in emmetropic eyes both before and after accommodation (before: p = 0.0004, after: p < 0.0001). From these results, we confirmed that iris concavity after accommodation occurs in normal eyes but not enough for iridozonular contact, and that pigment dispersion syndrome results from augmented iris concavity owing to pre-existing factors such as iris flexibility, myopia, and sufficient accommodation power.

Intraperitoneal fat sign

In a patient with an ovarian cystic teratoma and the peritoneal cavity filled with sebaceous material, an abdominal radiograph revealed a wide fat stripe between the parietal peritoneum and the lateral wall of the ascending colon. We called the existence of the wide fat stripe, which implied large amounts of intraperitoneal fatty material, the "intraperitoneal fat sign."

[Distribution of cell adhesion glycoproteins in the human retrobulbar optic nerve]

We examined the immunohistochemical distribution of six types of cell adhesion glycoproteins in the human retrobulbar optic nerve. The pial septa had laminin and entactin on the surface at the border with the optic nerve fibers, and fibronectin and vitronectin were distributed in the stroma of the septa. Some tenastin was also detectable both on the surface and in the stroma of the septa. Thrombospondin was associated with capillaries within the stroma. The surface of the arachnoid membrane, the pia mater, and the dura mater was covered by laminin and entactin. Diffuse staining with antifibronectin antibody was seen in all these meningeal tissues, but vitronectin showed a fine fibrillar appearance in these tissues. No significant staining could be found for tenastin. Thrombospondin showed only faint staining on the capillaries of the pia mater and the dura mater. These findings can provide clues for the discussion of how the extracellular matrix works and what roles it plays in disorders involving the retrobulbar optic nerve, such as optic neuritis and glaucoma.

High signal intensity of the infundibular stalk on fluid-attenuated inversion recovery MR

PURPOSE

To determine the MR imaging characteristics of the pituitary stalk with a fluid-attenuated inversion recovery (FLAIR) technique.

METHODS

We retrospectively studied the prevalence of a high-signal infundibular stalk on FLAIR MR images of the brain in 133 patients and compared this finding with the patients' ages. To understand the cause of the high signal intensity of the pituitary stalk on FLAIR images, we calculated the T1, T2, and proton-density values in regions of gray matter, white matter, and the pituitary stalk in nine cases.

RESULTS

FLAIR images showed the pituitary stalk as having high signal intensity in 97 (73%) of 133 cases; however, in 11 of 16 patients less than 10 years old, the infundibular stalk was not of high signal intensity. In patients with a high-signal pituitary stalk on FLAIR images, the T2 value of the pituitary stalk was longer than that of gray or white matter.

CONCLUSION

High signal intensity of the infundibular stalk was frequently seen on FLAIR MR images of the brain at all ages. A prolonged T2 value of the pituitary stalk caused the high signal intensity, presumably reflecting the fluid component of the pituitary stalk.

Renal cell carcinoma: preoperative assessment for enucleative surgery with angiography, CT, and MRI

PURPOSE

Our purpose was to assess various imaging methods in detecting a pseudocapsule of renal cell carcinoma (RCC), which is critical for successful tumor enucleation.

METHOD

In 42 patients with histopathologically proven RCC, images obtained at angiography (n = 42), CT (n = 30), and MRI (n = 19) were investigated retrospectively. All patients underwent treatment (enucleation: n = 15; nephrectomy: n = 27). The imaging criteria for the presence of a pseudocapsule were as follows: a surrounding radiolucent rim on angiography, a low or high density rim on CT, and a low intensity rim on MRI. All images were retrospectively reviewed by three radiologists without knowledge of the clinical and histological findings.

RESULTS

Thirty-three of 42 RCCs showed a pseudocapsule on the surgical specimen. A pseudocapsule was detected in 67% of tumors (22/33) on angiography, 26% (6/23) on CT, 27% (4/15) on T1-weighted MRI, 93% (14/15) on T2-weighted MRI, 67% (8/12) on dynamic enhanced T1-weighted MRI, and 15% (2/13) on delayed enhanced T1-weighted MRI.

CONCLUSION

T2-weighted MR images are superior for visualizing a pseudocapsule of RCC and for providing reliable selection criteria for tumor enucleation.

Renal cell carcinoma: preoperative assessment for enucleative surgery with angiography, CT, and MRI

PURPOSE

Our purpose was to assess various imaging methods in detecting a pseudocapsule of renal cell carcinoma (RCC), which is critical for successful tumor enucleation.

METHOD

In 42 patients with histopathologically proven RCC, images obtained at angiography (n = 42), CT (n = 30), and MRI (n = 19) were investigated retrospectively. All patients underwent treatment (enucleation: n = 15; nephrectomy: n = 27). The imaging criteria for the presence of a pseudocapsule were as follows: a surrounding radiolucent rim on angiography, a low or high density rim on CT, and a low intensity rim on MRI. All images were retrospectively reviewed by three radiologists without knowledge of the clinical and histological findings.

RESULTS

Thirty-three of 42 RCCs showed a pseudocapsule on the surgical specimen. A pseudocapsule was detected in 67% of tumors (22/33) on angiography, 26% (6/23) on CT, 27% (4/15) on T1-weighted MRI, 93% (14/15) on T2-weighted MRI, 67% (8/12) on dynamic enhanced T1-weighted MRI, and 15% (2/13) on delayed enhanced T1-weighted MRI.

CONCLUSION

T2-weighted MR images are superior for visualizing a pseudocapsule of RCC and for providing reliable selection criteria for tumor enucleation.

Production of hydroxyl radicals by copper-containing metallothionein: roles as prooxidant

Production of hydroxyl radicals by copper (Cu)-containing metallothionein (MT) and its relation to zinc (Zn) bound to MT were studied in vitro with reference to the mechanism of the Cu toxicity in the liver of LEC rats. Zn-MT prepared from the liver of Zn-injected rats was reacted with cupric ions at various Cu/Zn ratios, and the concentrations of the two metals bound to MT and in the solution, valence states of Cu in the solution, production of hydroxyl radicals were determined. Cupric ions replaced Zn in MT after being reduced by thiol groups, and MT, worked as an antioxidant. Cupric ions added to MT that did not contain Zn were reduced to cuprous ions by thiol groups in Cu-MT, and the Cu bound to MT was liberated in a form of cuprous ions. Hydroxyl radicals were produced in the presence of hydrogen peroxide in proportion to the amount of cuprous ions liberated from MT. Cu-containing MT was proposed to work as a prooxidant until all thiol groups in MT were oxidized when Zn was not present in MT. The results indicate that MT works as an antioxidant as long as Zn is present in Cu-containing MT, while it works as a prooxidant when Zn is not present by liberating 1.5 M equivalents of cuprous ions relative to cupric ions added, and hydroxyl radicals are produced in the presence of hydrogen peroxide. On the other hand, MT not bound by Cu does not work as a prooxidant throughout.

Elimination of low-osmolality contrast media by hemodialysis

PURPOSE

To compare the dialyzability and safety of 2 types of low-osmolality contrast media administered to end-stage renal failure patients maintained on regular hemodialysis.

MATERIAL AND METHODS

Of 44 CT examinations, iohexol was used in 22 and ioxaglate in the other 22. Adverse reactions and hemodynamic changes were recorded. Thirty minutes after the beginning of CT investigation, hemodialysis was commenced. Elimination rate and clearance of the contrast media were measured as indices of their dialyzability.

RESULTS

After 4 hours of hemodialysis, 78.4+/-6.5% of iohexol and 72.4+/-6.0% ioxaglate were eliminated. Clearance of iohexol was higher than that of ioxaglate at all sampling times. No severe hemodynamic change nor adverse reaction were observed. Minor reactions were more frequently observed in the ioxaglate group.

CONCLUSION

Iohexol, a nonionic monomeric contrast medium, is more advantageous for hemodialysis patients than ioxaglate, an ionic dimeric contrast medium.

Elimination of iomeprol by hemodialysis

Iomeprol is commercially a relatively new type of contrast medium. There have been no reports concerning its dialysability and safety when administered to patients with end-stage renal failure undergoing regular therapeutic hemodialysis (HD). One hundred milliliters of iomeprol (350 mgl/ml) was injected intravenously at computed tomography in 10 patients suffering from chronic renal failure. HD was then performed within 30 min after the start of iomeprol injection. The duration of HD was 4 h and blood samples were taken at 15, 30 min, 1, 2 and 4 h after its start. Mean dialysance of urea was 176.0-182.9 ml/min, compared to 131.4-133.3 ml/min for iomeprol. Elimination rate of iomeprol was 821.4 +/- 4.6% 4 h after the start of HD. Two of the 10 patients had side effects. One of them complained of a heat sensation and the other of sneezing and rash. As 4-h HD effectively removed iomeprol from the body and there were no severe side effects, it is concluded that iomeprol is suitable for HD patients.

[A simultaneous determination of various main components in oriental pharmaceutical decoction "heii-san" by ion-pair high-performance liquid chromatography]

A simple and precise method was established for the simultaneous determination of five selected marker components in oriental pharmaceutical decoction "Heii-San" by means of high-performance liquid chromatography using tetra-n-amylammonium bromide (TAA) as an ion-pair reagent. For the separation of these five components, such as hesperidin (1), 6-gingerol (2), honokiol (3), glycyrrhizin (4) and magnolol (5), an ODS column was used with multi-step gradient elution with 10 mM TAA (H3PO4, pH 4.0)-acetonitrile. The acetonitrile content linearly increased from 25 to 90%. This method was compared with other three methods, i.e. a water-acetonitrile method, a phosphate buffer method and an ion-suppression method. Five main components were eluted within 50 min without interference from co-existing components.

A comparison of scavenging abilities of antioxidants against hydroxyl radicals

The reactivities of various antioxidative compounds including catechol derivatives and endogenous radical scavengers toward hydroxyl radical (.OH) were investigated by an electron spin resonance-spin trapping method, thiobarbituric acid method, and DNA strand scission assay. Hydroxyl radical was generated by both the reaction of Cu(II) complex with hydrogen peroxide (H2O2) and ultraviolet (uv) photolysis of H2O2. At physiological pH, catechol derivatives such as protocatechuic acid and catechin greatly suppressed the DNA strand scission by .OH produced from the reaction of Cu(en)2 with H2O2, whereas ascorbic acid and acetylcysteine accelerated DNA strand scission. The former case is due to the chelation of catechol derivatives to Cu(II) ion, forming of Cu(II) complexes being unable to react with H2O2, and the latter case is due to the acceleration of the reduction rate of Cu(II) to Cu(I). On the other hand, all compounds used here suppressed the DNA strand scission by .OH produced from uv photolysis of H2O2. The differences of the reactivities between the reaction system of Cu(en)2-H2O2 and the uv photolysis of H2O2 have been discussed.

Elimination of ioversol by hemodialysis

PURPOSE

The dialysability of ioversol was investigated in 12 patients with chronic renal failure, on 4-h hemodialysis.

MATERIAL AND METHODS

One hundred ml of ioversol (320 mg I/ml) was injected in less than 10 min during CT. Hemodialysis was commenced within 30 min of starting the contrast medium injection and was continued for 4 h. Blood was sampled before and at 15 min, 30 min, 1 h, 2 h, and 4 h after the start of hemodialysis. Mean dialysance of ioversol was 114 to 129 ml/min and the elimination rate was 82.5 +/- 5.1% 4 h after starting hemodialysis. The half-life of ioversol during hemodialysis was 1.80 +/- 0.38 h. The only side effects of the ioversol injection were heat sensations, which were experienced by 3 patients.

RESULTS

As ioversol was effectively removed from the body during the 4 h of hemodialysis and no severe adverse reactions were observed, we conclude that ioversol is suitable for use in hemodialyzed patients.

Arterial embolization to control renal hemorrhage in patients with percutaneous nephrostomy

Two patients with renal hemorrhage treated by arterial embolization are reported. In one patient, one kidney was injured and the another had poor function. The other patient had one kidney. Although both patients had hematuria and underwent percutaneous nephrostomy, the bleeding location was not detected angiographically. Repeated embolization and irrigations through a nephrostomy catheter following each embolization arrested the bleeding.

[The production of high sensitive anti-myeloperoxidase monoclonal antibodies and their sensitivity and specificity]

We produced anti-myeloperoxidase(MPO) monoclonal antibodies(moAb) to detect MPO sensitivity in leukemic cells by visual light microscopy. We got seven kinds of moAbs which showed different properties to MPO. These antibodies reacted to MPO in immature and mature neutrophils, monocytes and HL-60(human myeloid leukemic cell line) by immunochemical detection using the avidin-biotin complex(ABC) staining method, but the amounts of immune complex products were significantly different at each moAb. MPO2, MPO4, MPO9 and MPO13 moAbs blocked MPO activities but MPO5 showed no such inhibition. Most of the moAbs reacted to 59kD MPO moAb using the western blotting method, while MPO4 and MPO5 reacted to both 81kD and 89kD MPO precursors. This data suggests that these moAbs are useful to demonstrate a small amount of MPO in leukemic cells.

Glycylsarcosyl-L-histidylglycine, A peptide with a "breakpoint" in complex formation: hydrolysis of the complex [CuH-1L]

Coordination of CU(II) with glycylsarcosyl-L-histidylglycine to form the series of [CuL] and [CuH-1L] was studied potentiometrically and spectroscopically. [CuL] includes the Cu(N2O)O chromophore, in which Cu(II) coordinates with nitrogens from the terminal amino and imidazole groups and a carbonyl oxygen of the Gly-Sar bond, and shows a d-d transition band at 696 nm in the absorption spectrum and at 648 nm in the CD spectrum. The predominant species around pH 8 was [CuH-1L] with Cu(N3O) chromophore, in which Cu(II) coordinates with three nitrogens from a terminal amino, a deprotonated Sar-His peptide bond, and an imidazole of a histidyl residue, and shows the d-d transition band at 652 and 580 nm in the absorption and CD spectra, respectively. This species was hydrolyzed at the Gly-Sar peptide bond, yielding the Cu(II) complex of sarcosyl-L-histidylglycine.

Gliomatosis cerebri: a case report

Gliomatosis cerebri is a rare disease that thus far was usually diagnosed at the time of autopsy. In this communication we report the case of a young woman with gliomatosis cerebri. Diagnosis was established on the basis of characteristic imaging findings and typical histopathological features of surgical specimens obtained by craniotomy.

Effects of hypergravity on growth and cell wall properties of cress hypocotyls

Elongation growth of etiolated hypocotyls of cress (Lepidium sativum L.) was suppressed when they were exposed to basipetal hypergravity at 35 x g and above. Acceleration at 135 x g caused a decrease in the mechanical extensibility and an increase in the minimum stress-relaxation time of the cell wall. Such changes in the mechanical properties of the cell wall were prominent in the lower regions of hypocotyls. The amounts of cell wall polysaccharides per unit length of hypocotyls increased under the hypergravity condition and, in particular, the increase in the amount of cellulose in the lower regions was conspicuous. Hypergravity did not influence the neutral sugar composition of either the pectin or the hemicellulose fraction. The amount of lignin was also increased by hypergravity treatment, although the level was low. The data suggest that hypergravity modifies the metabolism of cell wall components and thus makes the cell wall thick and rigid, thereby inhibiting elongation growth of cress hypocotyls. These changes may contribute to the plants' ability to sustain their structures against hypergravity.

Plant growth processes in Arabidopsis under microgravity conditions simulated by a clinostat

The life cycle of Arabidopsis plants was examined by growing them on a horizontal clinostat. Seeds on agar media were allowed to germinate and seedlings were grown under a simulated microgravity on a horizontal clinostat. Clinorotation (3 rpm) did not appear to interfere with germination of plant seeds and development of cotyledons and leaves. Stress relaxation parameters of the cell wall, the minimum relaxation time and the relaxation rate did not appear to be affected by clinostat rotation. On the other hand, the length of inflorescences was reduced to 61-62% by clinostat rotation. Rotation was found to inhibit the polar transport of auxin, although inflorescence growth and auxin transport were not completely inhibited. From these facts, it is possible that the life cycle in Arabidopsis plants could be accomplished in space, although growth phenomena involving auxin transport and its action may be disturbed. Plants may have a capacity to grow in space and we may be able to cultivate crops in space.

Kimura disease: CT and MR findings

The lesions of Kimura disease showed slightly high and very high intensity on T2-weighted MR, and low and intermediate intensity, respectively, on T1-weighted images. The degree of enhancement also differed between the two cases. These discrepancies may be attributable to differing degrees of fibrosis and vascular proliferation.

Oxidation of spin-traps by chlorine dioxide (ClO2) radical in aqueous solutions: first ESR evidence of formation of new nitroxide radicals

The reactivities of the chlorine dioxide (ClO2), which is a stable free radical towards some water-soluble spin-traps were investigated in aqueous solutions by an electron spin resonance (ESR) spectroscopy. The ClO2 radical was generated from the redox reaction of Ti3+ with potassium chlorate (KClO3) in aqueous solutions. When one of the spin-traps, 5,5-dimethyl-1-pyrroline N-oxide (DMPO), was included in the Ti3+-KClO3 reaction system, ESR spectrum due to the ClO2 radical completely disappeared and a new ESR spectrum [aN(1) = 0.72 mT, aH(2) = 0.41 mT], which is different from that of DMPO-ClO2 adduct, was observed. The ESR parameters of this new ESR signal was identical to those of 5,5-dimethylpyrrolidone-(2)-oxyl-(1) (DMPOX), suggesting the radical species giving the new ESR spectrum is assignable to DMPOX. The similar ESR spectrum consisting of a triplet [aN(1) = 0.69 mT] was observed when the derivative of DMPO, 3,3,5,5-tetramethyl-1-pyrroline N-oxide (M4PO) was included in the Ti3+-KClO3 reaction system. This radical species is attributed to the oxidation product of M4PO, 3,3,5,5-tetramethylpyrrolidone-(2)-oxyl-(1) (M4POX). When another nitrone spin-trap, alpha-(4-pyridyl-1-oxide)-N-t-butylnitrone (POBN) was used as a spin-trap, the ESR signal intensity due to the ClO2 radical decreased and a new ESR signal consisting of a triplet [aN(1) = 0.76 mT] was observed. The similar ESR spectrum was observed when N-t-butyl-alpha- nitrone (PBN) was used as a spin-trap. This ESR parameter [a(N)(1) = 0.85 mT] was identical to the oxidation product of PBN, PBNX. Thus, the new ESR signal observed from POBN may be assigned to the oxidation product of POBN, POBNX. These results suggest that the ClO2, radical does not form the stable spin adducts with nitrone spin-traps, but oxidizes these spin-traps to give the corresponding nitroxyl radicals. On the other hand, nitroso spin-traps, 5,5-dibromo-4-nitrosobenzenesulfonate (DBNBS), and 2-methyl-2-nitrosopropane (MNP) did not trap the ClO2 radical. This result indicates that an unpaired electron of the ClO2 radical is localized on oxygen atom, because nitroso spin-traps cannot form the stable spin adduct with oxygen-centered radical.