Inhibition of Azoxymethane-induced Colorectal Aberrant Crypt Foci in Mice Fed a High-fat Diet by Pleurotus eryngii (Eringi) and Hypsizygus marmoreus (Bunashimeji)

Obesity markedly increases the risk of colorectal cancer. Recently, the preventive effects of edible mushrooms on triglyceride elevation and visceral fat accumulation have been reported. Here, the effects of Pleurotus eryngii (Eringi) and Hypsizygus marmoreus (Bunashimeji) on azoxymethane (AOM)-induced aberrant crypt foci (ACF; precancerous lesions) in the colorectums of mice fed a high-fat diet were examined. Eringi (ER) and Bunashimeji (BU) mushroom powder samples were used. Six-week-old male C57BL/6J mice received an intraperitoneal injection of AOM (10 mg/kg) once a week for two weeks, and were sacrificed and dissected at 6 weeks after the start of the experiment. After the initiation of the experiment, they received a normal diet (ND), high-fat diet (HFD), HFD + ER (1 or 5% of diet), or HFD + BU (1 or 5% of diet). As a result, body and fat weights were significantly lower in the 5% ER and BU groups than in the HFD group. Liver triglyceride levels were also significantly lower in the 5% ER and BU groups. Total liver cholesterol levels were significantly lower in the 5% ER group. The numbers of ACF (especially large ACF) showed strong inhibitory effects in both ER and BU groups. Measurement of the cell proliferation marker Ki-67 labeling index in the colonic mucosa demonstrated more significant suppression in both ER and BU groups than in the HFD group. These results suggest that the simultaneous intake of ER and BU may inhibit colorectal tumorigenesis in HFD-fed mice.

Effects of Aloe-emodin and Emodin on Proliferation of the MKN45 Human Gastric Cancer Cell Line

Aloe-emodin (1, 8-dihydroxy-3-hydroxyl-methylanthraquinone; AE) and emodin (1,3,8-trihydroxy-6- methylanthraquinone; EM) are anthraquinone derivatives that have been detected in some medical plants and share similar anthraquinone structures. AE and EM have been shown to exhibit anticancer activities in various cancer cell lines; however, the inhibitory effects of these derivatives on the growth of cancer cells were previously reported to be different. Gastric cancer is the second most common cause of cancer cell death worldwide. In the present study, we examined the inhibitory effects of 0.05 mM AE and 0.05 mM EM on the proliferation of the MKN45 human gastric cancer cell line. The proliferation of MKN45 cells was significantly inhibited in AE- and EM-treated groups 24 h and 48 h after treatment. Furthermore, the inhibitory effects of EM were stronger than those of AE. The cell cycle of MKN45 cells were arrested in G0/G1 phase or G0/G1 and G2/M phases by AE and EM, respectively. However, an analysis of intracellular polyamine levels and DNA fragmentation revealed that the mechanisms underlying cell death following cell arrest induced by AE and EM differed.

Dietary aloe vera gel powder and extract inhibit azoxymethane- induced colorectal aberrant crypt foci in mice fed a high- fat diet

Aloe vera gel exhibits protective effects against insulin resistance as well as lipid-lowering and anti-diabetic effects. The anti-diabetic compounds in this gel were identified as Aloe-sterols. Aloe vera gel extract (AVGE) containing Aloe-sterols has recently been produced using a new procedure. We previously reported that AVGE reduced large-sized intestinal polyps in Apc-deficient Min mice fed a high fat diet (HFD), suggesting that Aloe vera gel may protect against colorectal cancer. In the present study, we examined the effects of Aloe vera gel powder (AVGP) and AVGE on azoxymethane-induced colorectal preneoplastic aberrant crypt foci (ACF) in mice fed a HFD. Male C57BL/6J mice were given a normal diet (ND), HFD, HFD containing 0.5% carboxymethyl cellulose solution, which was used as a solvent for AVGE (HFDC), HFD containing 3% or 1% AVGP, and HFDC containing 0.0125% (H-) or 0.00375% (L-) AVGE. The number of ACF was significantly lower in mice given 3% AVGP and H-AVGE than in those given HFD or HFDC alone. Moreover, 3% AVGP, H-AVGE and L-AVGE significantly decreased the mean Ki-67 labeling index, assessed as a measure of cell proliferation in the colonic mucosa. In addition, hepatic phase II enzyme glutathione S-transferase mRNA levels were higher in the H-AVGE group than in the HFDC group. These results suggest that both AVGP and AVGE may have chemopreventive effects on colorectal carcinogenesis under the HFD condition. Furthermore, the concentration of Aloe-sterols was similar between 3% AVGP and H-AVGE, suggesting that Aloe-sterols were the main active ingredients in this experiment.

Inhibitory effects of low-dose aloe-emodin on the development of colorectal tumors in min mice

Aloe-emodin (AE), a natural anthraquinone compound, has been reported to exhibit anticancer activity in various cancer cell lines and anti-inflammatory effects in murine macrophages. In the present study, we investigated the cancer chemopreventive effects of AE in an Apc-deficient Min mouse model. In the first experiment, male Min mice were fed a basal diet or diets containing 5 ppm AE and 10 ppm AE for 12 weeks. The dietary administration of 5 ppm AE significantly reduced the number of colorectal tumors. In a second experiment, we investigated the effects of AE on colitis-related colon carcinogenesis in Min mouse treated with dextran sodium sulfate (DSS). Female Min mice were administered 1% DSS in their drinking water for 7 days. AE was given to mice in their diet at a dose of 5 or 50 ppm for 5 weeks. Feeding with AE significantly reduced the number of colorectal tumors. When proliferation of cells in normal-appearing colonic mucosa was assessed by monoclonal anti-rat Ki-67 antibody (MIB-5) immunohistochemistry in experiments 1 and 2, the AE treatment significantly decreased the mean MIB-5-labeling index. These results suggest that the dietary administration of low-dose AE may have chemopreventive effects against development of colorectal tumors in Min mice, possibly in part by reducing cell proliferation in colorectal mucosa.

Changes in serum growth factors in stroke rehabilitation patients and their relation to hemiparesis improvement

Predicting recovery from hemiparesis after stroke is important for rehabilitation. A few recent studies reported that the levels of some growth factors shortly after stroke were positively correlated with the clinical outcomes during the chronic phase. The aim of this study was to examine the relationships between the serum levels of growth factors (vascular endothelial growth factor [VEGF], insulin-like growth factor-I [IGF-I], and hepatocyte growth factor [HGF]) and improvement in hemiparesis in stroke patients who received rehabilitation in a postacute rehabilitation hospital. Subjects were 32 stroke patients (cerebral infarction: 21 and intracerebral hemorrhage [ICH]: 11). We measured serum levels of VEGF, IGF-I, and HGF and 5 items of the Stroke Impairment Assessment Set (SIAS) for hemiparesis on admission and at discharge. Age-matched healthy subjects (n=15) served as controls. Serum levels of VEGF and HGF in cerebral infarct patients on admission were higher than those in control subjects, and the serum levels of IGF-I in stroke patients were lower than those in controls. The level of HGF in ICH patients on admission was negatively correlated with gains in SIAS, and higher outliers in HGF concentration were correlated with lower gains in SIAS. Focusing on the extremely high levels of these factors may be a predictor of the low recovery from hemiparesis after stroke.

Reduction of intestinal polyp formation in min mice fed a high-fat diet with aloe vera gel extract

Aloe vera gel supercritical CO2 extract (AVGE) has been shown to contain five phytosterols, reduce visceral fat accumulation, and influence the metabolism of glucose and lipids in animal model experiments. Recent epidemiologic studies have shown that obesity is an established risk factor for several cancers including colorectal cancer. Therefore, we examined the effects of AVGE on intestinal polyp formation in Apc-deficient Min mice fed a high-fat diet. Male Min mice were divided into normal diet (ND), high fat diet (HFD), low dose AVGE (HFD+LAVGE) and high dose AVGE (HFD+HAVGE) groups. The ND group received AIN-93G diet and the latter 3 groups were given modified high-fat AIN-93G diet (HFD) for 7 weeks. AVGE was suspended in 0.5% carboxymethyl cellulose (CMC) and administered orally to mice in HFD+LAVGE and HFD+HAVGE groups every day (except on Sunday) for 7 weeks at a dose of 3.75 and 12.5 mg/kg body weight, respectively. ND and HFD groups received 0.5% CMC alone. Between weeks 4 and 7, body weights in the HFD and HFD+LAVGE groups were reduced more than those in the ND group. However, body weights were not reduced in the HFD+HAVGE group. Mice were sacrificed at the end of the experiment and their intestines were scored for polyps. No significant differences were observed in either the incidence and multiplicity of intestinal polyps (≥0.5 mm in a diameter) among the three groups fed HFD. However, when intestinal polyps were categorized by their size into 0.5-1.4, 1.5-2.4, or ≥2.5 mm, the incidence and multiplicity of large polyps (≥2.5 mm) in the intestine in the HFD+HAVGE group were significantly lower than those in the HFD group. We measured plasma lipid (triglycerides and total cholesterol) and adipocytokine [interleukin-6 and high molecular weight (HMW) adiponectin] levels as possible indicators of mechanisms of inhibition. The results showed that HMW adiponectin levels in the HFD group were significantly lower than those in the ND group. However, the levels in the HFD+HAVGE group were significantly higher than those in the HFD group. These results indicate that HAVGE reduced large-sized intestinal polyps and ameliorated reduction in plasma HMW adiponectin levels in Min mice fed HFD.

Pelvic axis-based gait analysis for ataxic mice

BACKGROUND

Although different gait analysis methods such as Walking Track Analysis exist, they cannot be used to demonstrate the physical condition of mice with specific gait disorder characteristic. Therefore, we developed a new method for the gait analysis of such mice to accurately assess hind limb angle based on the pelvic axis.

NEW METHOD

We established and verified a gait analysis method capable of pelvic axis-based limb angle measurement by video-recording the gait of a control mice group (C57BL/6J(B6)) and three ataxic mice (ataxic B6-wob/t, Parkinson's disease model (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine treated (MPTP)), and cerebellum hypoplasia (cytosine-β-d-arabinofuranoside treated)) from the ventral side.

RESULTS

The assessed hind limb angles of B6-wob/t and MPTP-treated mice were significantly wider than B6 mice (p<0.01). Moreover, we could draw separating lines with slopes of minus one that could separate the data of each group in the scatter plot of the normalized hind limb step width and angle.

COMPARISON WITH EXISTING METHODS

We found no significance when we applied the already existing nose-tail method for the analysis of the hind limb angles of B6 and B6-wob/t mice. In the nose-tail method, since the whole body axis of the trunk varies while the trunk of the mouse is laterally bent changing the hind limb angle, B6 and B6-wob/t mice could not be differentiated. However, the two mice groups could be differentiated by the pelvic axis-based gait analysis method.

CONCLUSION

The pelvic axis-based gait analysis method is promising and valid for mice with gait disorder.

Inhibition of ENNG-induced pyloric stomach and small intestinal carcinogenesis in mice by high temperature- and pressure-treated garlic

High temperature- and pressure-treated garlic (HTPG) has been shown to have enhanced antioxidative activity and polyphenol contents. Previously, we reported that HTPG inhibited 1,2-dimethylhydrazine-induced mucin depleted foci (premalignant lesions) and O6-methylguanine DNA adduct formation in the rat colorectum. In the present study, we investigated the modifying effects of HTPG on N-ethyl-N'-nitro-N-nitrosoguanidine (ENNG)- induced pyloric stomach and small intestinal carcinogenesis in mice. Male C57BL/6 mice were given ENNG (100 mg/l) in drinking water for the first 4 weeks, then a basal diet or diet containing 2% or 5% HTPG for 30 weeks. The incidence and multiplicity of pyloric stomach and small intestinal (duodenal and jejunal) tumors in the 2% HTPG group (but not in the 5% HTPG group) were significantly lower than those in the control group. Cell proliferation of normal-appearing duodenal mucosa was assessed by MIB-5 immunohistochemistry and shown to be significantly lower with 2% HTPG (but again not 5% HTPG) than in controls. These results in dicate that HTPG, at 2% in the diet, inhibited ENNG-induced pyloric stomach and small intestinal (especially duodenal) tumorigenesis in mice, associated with suppression of cell proliferation.

Inhibition of 1, 2-dimethylhydrazine-induced mucin-depleted foci and O⁶-methylguanine DNA adducts in the rat colorectum by boiled garlic powder

The scavenging capacity of reactive oxygen species, such as hydroxyl radicals, is reported not to decrease in boiled garlic (an odorless garlic preparation). We therefore examined the modifying effect of boiled garlic powder (BGP) on 1,2-dimethylhydrazine-induced mucin-depleted foci (MDF) and aberrant crypt foci (ACF), preneoplastic lesions, in the rat colorectum. Male F344 rats (5 weeks old) were fed a basal diet, or experimental diets containing 5% or 1% BGP for 5 weeks. One week later, all rats were injected s.c. with DMH (40 mg/kg, once weekly for 2 weeks). At 10 weeks of age, all the rats were sacrificed, and the colorectum was evaluated for MDF and ACF. In rats given DMH and the 5% or 1% BGP diets (Groups 2 and 3), the numbers of MDF decreased significantly in a dose-dependent manner, compared with the DMH and basal diet value (Group 1) (p<0.01). The numbers of ACF in Group 2, but not Group 3, showed a non-significant tendency to decrease. Next, the effects of BGP on the formation of DMH-induced O6-methylguanine (O6-MeG) DNA adducts in rats were studied. Male F344 rats (5 weeks old) were fed the basal diet, or 10% BGP diet for 5 weeks. All rats were injected i.p. once with 40 mg/kg DMH at the end of week 5. The animals were sacrificed 6 hours after DMH injection to analyze the O6-MeG DNA adducts in the colorectal mucosa. Dietary administration of BGP significantly inhibited the O6-MeG DNA adduct levels in the colorectal mucosa, compared with the controls (p<0.01). These results suggested that BGP may exert chemopreventive effects against colon carcinogenesis at least in the initiation stage.

Inhibitory effects of high temperature- and pressure-treated garlic on formation of 1,2-dimethylhydrazine-induced mucin-depleted foci and O(6)-methylguanine DNA adducts in the rat colorectum

High temperature- and pressure-treated garlic (HTPG) has been reported to have enhanced antioxidative and cytotoxic activities. However, there have been no reports on chemopreventive effects using animal cancer models. This study first examined the modifying effects of HTPG on 1,2-dimethylhydrazine (DMH)-induced mucin-depleted foci (MDF) and aberrant crypt foci (ACF), preneoplastic lesions in the rat colorectum. Male F344 rats (5 weeks old) were fed basal diet, or experimental diets containing 1% or 3% HTPG for 5 weeks. One week later, all rats were injected s.c.with DMH (40 mg/kg, once weekly for 2 weeks). At 10 weeks of age, all the rats were sacrificed, and the colorectum was evaluated for MDF and ACF. In rats given DMH and 3% HTPG, the numbers of MDF were decreased significantly as compared with those of rats given DMH alone (p< 0.01), and the numbers of ACF showed a tendency to decrease, although not significantly. Next, the effects of HTPG on the formation of DMH-induced O6-methylguanine (O6-MeG) DNA adducts in rats were studied. Male F344 rats (5 weeks old) were fed the basal diet or 10% HTPG diet for 5 weeks. All rats were injected i.p. once with 40 mg/kg DMH at the end of week 5. The animals were sacrificed 6 hours after DMH injection to analyze the O6-MeG DNA adducts in the colorectal mucosa and liver. Dietary administration of HTPG significantly reduced the adduct levels in the colorectal mucosa and liver, compared with the controls (both p< 0.01). The activities of some detoxification enzymes in the liver of DMH-treated rats were also measured. HTPG significantly reduced the activity of cytochrome P450 (CYP) 2E1, known to be responsible for activation of DMH in rat liver (p< 0.05). In contrast, HTPG significantly enhanced the activities of phase 2 enzymes, quinone reductase (QR) and glutathione S-transferase (GST), in rat liver (both p< 0.05). These results suggested that HTPG might have chemopreventive effects against colon carcinogenesis, at least in the initiation stage.

Stromal inactivation of BMPRII leads to colorectal epithelial overgrowth and polyp formation

Stromal-epithelial interactions play a central role in development and tumorigenesis. Bone morphogenetic protein (BMP) signaling in the intestine is involved in both of these processes. Inactivation of BMP pathway genes in the epithelium is known to cause intestinal polyposis. However, the role of the intestinal stroma in polyp initiation is incompletely understood. We observed that conditional inactivation of the BMP type II receptor (BMPRII) in the stroma leads to epithelial hyperplasia throughout the colon with increased epithelial cell proliferation. Mutant mice developed rectal bleeding and hamartomatous polyps in the colorectum. The polyps demonstrated increased proliferation of epithelial and mesenchymal cells in the mucosa with an expansion of the myofibroblast cell population. These results demonstrate that genetic mutations altering the BMP signaling pathway in the stromal microenvironment can lead to epithelial tumors in the colon.

An Asian variant of intravascular lymphoma: unique clinical and pathological manifestation in the gallbladder

We here present a rare case of intravascular lymphoma (IVL) in a Japanese man. 4 months after cholecystectomy due to cholecystitis, a diagnosis of intravascular lymphoma (IVL) was strongly suspected. Lymphoma cells were diffusely observed in the bone marrow parenchyma, but were absent in the vascular spaces. The patient died of respiratory failure and at autopsy a small number of lymphoma cells in the extravascular parenchyma of the adrenal gland and bone marrow were seen. Serial sections of the surgically resected gallbladder retrospectively confirmed the diagnosis of IVL. In addition, congestion and edema were observed in the connective tissue layer. It is possible that edema or ischemia in the gallbladder wall or at other anatomic sites due to the circulation disturbance induced by the intravascular obstruction of lymphoma cells may have caused the initial symptoms. In conclusion, clinicians and pathologists should keep in mind that the gallbladder may be initially involved in IVL.

[Relationship between cytokine concentration and activities of daily living in rehabilitation patients with stroke]

Stroke rehabilitation is effective in some patients, however not so effective in others. Our ultimate aim is to use the clinical laboratory assessment as a tool for effectiveness discrimination in rehabilitation. Subjects were 15 stroke patients (68.1 +/- 12.7 years old) who were admitted to our convalescent rehabilitation wards. Fasting blood samples were analyzed for serum concentrations of hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF) and insulin-like growth factor-I (IGF-I) which are considered to be involved in hypermyotrophy using ELISA methods on admission and at discharge. Sixteen healthy control subjects (63.0 +/- 7.6 years old) were also employed. As accuracy control of these analyses, decrease of serum HGF after keeping at -20 degrees C for 499 days were measured. The concentration was 0.66ng/mL from 0.71 ng/mL and residual ratio was 94.0%. Reaction specificity to MW 60 kDa HGF antibody using the Western blot method was confirmed. Average HGF and VEGF were higher in stroke patients than those in control subjects. Average IGF-I was lower in stroke patients. The correlations between HGF, VEGF, and IGF-I and the score of activities of daily living expressed by the Functional Independence Measure (FIM) were calculated. Highest correlation coefficient of 0.67 (p < 0.01) was obtained between HGF at discharge and the FIM efficiency (the gain of the FIM during hospitalization divided by length of stay). The correlation coefficients related to VEGF or IGF showed lower value. High FIM efficiency denotes rapid recovery with vigorous exercise. HGF at discharge would reflect the result of high activity.

Effects of aloe arborescens ingestion on azoxymethane-induced intestinal carcinogenesis and hematological and biochemical parameters of male F344 rats

We examined the modifying effect of freeze-dried whole-leaf Aloe arborescens Miller var. natalensis Berger (Kidachi aloe in Japan; designated as 'ALOE') on azoxymethane (AOM)-induced intestinal carcinogenesis in rats. Male F344 rats (4 weeks old) were fed basal diet or experimental diet containing 0.2% or 1% ALOE for 28 weeks. Starting two weeks later, the animals received subcutaneous injections of AOM once weekly for 10 weeks. The incidence of colorectal adenocarcinomas in the 0.2% (but not 1%) ALOE group showed a strong tendency for decrease (p = 0.056) from the control group. Further, the adenocarcinoma incidence in the entire intestine (small and large intestines) in the 0.2% ALOE group was significantly (p = 0.024) decreased compared to the control value. However, there were no significant differences in tumor multiplicities of colorectal or entire intestines among the 3 groups. In addition, we also studied the safety of long-term ingestion of ALOE as a health food or natural thickening stabilizer. Rats were fed the basal diet or 1% ALOE diet for 35 weeks without AOM treatment. Feeding with 1% ALOE did not affect most hematological and serum biochemical parameters in the rats. These results indicate that a low level of ALOE ingestion might have a mild suppressive effect on intestinal tumor growth without harmful side effects.

Antidiabetic effects of dietary administration of Aloe arborescens Miller components on multiple low-dose streptozotocin-induced diabetes in mice: investigation on hypoglycemic action and systemic absorption dynamics of aloe components

We carried out three experimental trials to determine antidiabetic effects of Aloe arborescens Miller components. Firstly, ICR mice which received frequent injections of streptozotocin (Sz) in small doses (low-dose Sz-induced diabetes mice) were fed ad libitum with basal diets supplemented with components of Aloe arborescens Miller var. natalensis Berger (Kidachi aloe) and Aloe vera Linne from 31 days before to 73 days after the Sz injections. Variation in blood glucose levels, incidence rates of insulitis and blood insulin levels were examined during the trial. As a result, groups receiving diets supplemented at the rate of 2% with whole leaf of Kidachi aloe and 10 KDa fraction powder (a fraction with less than 10 KDa molecular weight derived from Kidachi aloe leaf skin juice by ultra filtration) significantly suppressed the elevation of blood sugar as compared to a control group receiving basal diet. In contrast, there was no significant effect with Aloe vera leaf pulp powder. Insulitis emerged at the rate of 87% in the basal diet group. On the contrary, the whole aloe leaf and 10 KDa fraction groups significantly decreased the incidence of insulitis and incidence rates of whole aloe leaf and 10 KDa fraction powder were 51 and 38%, respectively. While insulin levels in the basal diet group averaged at 0.05 ng, more than four times the insulin level was observed in the 10 KDa group relative to the basal diet group. Secondary, the inhibitory effects of test materials on intestinal glucose absorption were observed using the jejunum of rats. A strong inhibitory action on intestinal glucose absorption was observed in the 10 KDa fraction powder group. Thirdly, phenol compounds derived from aloe in the blood serum and organs were quantitatively measured by a HPLC following forced administration of aloe components to rats to determine absorption kinetics of aloe components inside the body. The primary component of aloe phenol compounds is the same component of the 10 KDa fraction powder and it was found in the pancreas and liver in addition to in the blood serum. The above results indicate that fore and aft when Sz injections could cause selective toxicity to B cells of islets, the dietary administration of 10 KDa fraction powder to mice would lead to the persistence of aloe phenol compound having an antioxidant activity in the pancreas and blood, which could protect islets of Langerhans from the destruction caused by methyl radical derived from Sz. The results also suggested the possibility of the 10 KDa fraction powder to alleviate the burden of insulin secretion as it has an inhibitory action on glucose absorption in the jejunum of rats.

Inhibitory effects of aloe carboxypeptidase fraction on streptozotocin-induced enhancement of vascular permeability in the pancreatic islets

The protective actions of components isolated from Aloe arborescens Miller var. natalensis Berger (Kidachi aloe in Japanese) on streptozotocin (Sz)-induced necrosis of B cells in the pancreatic islets of the mouse were investigated to clarify its action mechanism involved in anti-diabetic effects. In this experiment, phenol low molecular weight components of aloin and aloin A that were anti-oxidants and derived from the leaf skin or pulp extract, an aloe carboxypeptidase fraction that is a inhibitor of enhanced vascular permeability and a glycoprotein component that decreases blood glucose were tested with mice precedently administered with Sz which is known as a cytotoxin specific to B cells. The results showed that the treatment group receiving Sz followed by the aloe carboxypeptidase fraction increased the inhibition of dye leakage by 75.8% (p<0.001) in the extract of whole pancreas in comparison to the control group and the aloe carboxypeptidase fraction group also increased the inhibition effect by 68.4% (p<0.001) in the extract of pancreatic islets as compared to the control group. The carboxypeptidase is an aloe-derived protease known to inhibit the acetic acid-related enhancement of intraperitoneal vascular permeability in mice. Further, the elevation of blood glucose in Sz-induced diabetic mice intraperitoneally given the aloe carboxypeptitase fraction was significantly (p<0.01-0.001) restrained at 3, 7 and 14 days after the injection as compared to the control group given solvent only. The results of this experiment suggested that the inhibitory effect on the enhancement of vascular permeability related to the vascular acute inflammatory response at Sz-induced lesions of pancreatic islets was involved in the action mechanism of this enzyme.

Radical-scavenging effects of Aloe arborescens Miller on prevention of pancreatic islet B-cell destruction in rats

We evaluated the possible scavenging effects of Aloe arborescens Miller var. natalensis Berger (Kidachi aloe in Japanese) on free radicals generated by streptozotocin (Sz) or alloxan (Ax). The components of Kidachi aloe were added to a reaction system in which .OH radicals derived from Sz or Ax as pancreatic islet B-cell toxins and hypoxanthine-xanthine oxidase (HX-XO)-derived O(2) radicals destroy isolated islet B-cells, and we observed its preventive effects. The Kidachi aloe components inhibited the destruction of rat pancreatic islet B-cells by Sz, Ax or HX-XO. These components were prepared in the form of a freeze-dried powder of the boiled leaf skin of Kidachi aloe, and measurement of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity showed higher radical-scavenging activity in this boiled leaf skin powder than the non-boiled leaf skin powder.Furthermore, HPLC chromatograms of the "Boiled leaf skin powder" were similar to those of commercially available aloin (barbaloin content: approximately 20%). Therefore, the main component may be a phenol compound. In addition, the phenolic fraction of the Boiled leaf skin contained large amounts of 2'-O-p-coumaroylaloesin and 2'-O-feruloylaloesin, which have higher DPPH radical-scavenging activity than barbaloin. These results suggest that the action mechanism of Kidachi aloe Boiled leaf skin components, which prevent destruction of the pancreatic islets by specific pancreatic islet toxins such as Sz, Ax, and HX-XO, involves inhibition of free radical-scavenging effects, and may be associated with a thermostable low molecular component. The co-existence of Kidachi aloe-derived 2'-O-p-coumaroylaloesin, 2'-O-feruloylaloesin, and aloin may result in the potentiation of radical-scavenging activity.

Inhibition of azoxymethane-induced DNA adduct formation by Aloe arborescens var. natalensis

To clarify the possible mechanisms of inhibition of azoxymethane (AOM)-induced aberrant crypt foci (ACF) in the rat colorectum by freeze-dried whole leaves of Aloe arborescens var. natalensis (Kidachi aloe) (hereinafter referred to as ALOE) and commercial crude aloin (Sigma A-0451; from Curacao aloe) (hereinafter ALOIN), we studied the effects of ALOE and ALOIN on the formation of AOM-induced DNA adducts (O6-methylguanine; O6-MeG) in rats. Male F344 rats (4 weeks old) were fed a basal diet, or experimental diets containing 5%ALOE or 0.25%ALOIN for 5 weeks. All rats were injected s.c. twice with 15 mg/kg AOM, once at the end of week 1, and once at the end of week 2. The animals were sacrificed 6 hours after the second injection to analyze DNA adducts (O6-MeG) in the colorectum. Dietary administration of ALOE significantly inhibited the O6-MeG levels (50% reduction) compared with controls, whereas the O6-MeG levels in the ALOIN-fed rats showed a tendency to decrease (by 30%), although not significantly. In this study, we also measured the enzyme activity and mRNA level of cytochrome (CYP) 2E1, known to be responsible for the activation of AOM, in rat liver. ALOE-fed rats showed significantly reduced CYP2E1 enzymatic activity (27% reduction) compared with controls. On the other hand, the activity in ALOIN-fed rats tended to decrease by 11%, although not significantly. The CYP2E1 mRNA levels in ALOE- and ALOIN-fed rats were slightly reduced (9.7% and 5.2%, respectively). These results may explain, at least in part, the previously observed inhibitory effects of ALOE and ALOIN, especially ALOE on AOM-induced ACF formation in the rat colorectum.

Inhibitory Effects of Heated Garlic on N-Ethyl-N'-nitro-N-nitrosoguanidine-induced Carcinogenesis in the Duodenum and Jejunum of C57BL/6 Mice

We examined the modifying effects of heated garlic (Allium sativum L.) on N-ethyl-N'-nitro-N-nitrosoguanidine (ENNG)-induced duodenal and jejunal carcinogenesis in mice. Heated garlic powder used in this study was prepared as follows: unpeeled garlic bulbs were blanched in boiling water for 6 min, and then peeled, the cloves being crushed, homogenized, and finally freeze-dried. The garlic powder had almost undetectable alliinase activity and was rich in alliin (the main sulfur compound of heated garlic; 22.1 &mgr;/g dry weight). Male C57BL/6 mice were given ENNG (100 &mgr;/l) in drinking water for the first 4 weeks, and then basal diet (Group 1), or 10% (Group 2), 3% (Group 3) or 1% (Group 4) heated garlic in the diet for 30 weeks. At the termination of the experiment, the incidences of duodenal tumors in Groups 1-3 were significantly lower than those in Group 1, and the multiplicities in Group 2 were significantly lower than those in Group 1. Additionally, the incidences and/or multiplicities of the jejunal tumors in Groups 2 and 4 were also significantly lower than those in Group 1. In this study, we also examined changes in erythrocyte polyamine levels. Values for Group 1 were significantly greater than those in the control group, and this elevation in Group 1 were significantly inhibited by dietary heated garlic (10% in the diet; Group 2). These results indicated that the post-initiation-stage feeding of heated garlic, especially at 10% in the diet, inhibits ENNG-induced duodenal and jejunal carcinogenesis in mice.

Inhibition of N-ethyl-N'-nitro-N-nitrosoguanidine-induced Duodenal Tumorigenesis in Mice by Whole-leaf Aloe arborescens Miller var. natalensis Berger

We examined the modifying effects of freeze-dried whole-leaf Aloe arborescens Miller var. natalensis Berger (designated as 'ALOE') on N-ethyl-N'-nitro-N-nitrosoguanidine (ENNG)-induced duodenal tumorigenesis in C57BL/6 mice. Experiment 1: Male mice were given ENNG in drinking water for the first 4 weeks, and then 10% ALOE in basal diet for 16 weeks. Experiment 2: Female mice were given ENNG for 5 weeks, and then 5%, 1% or 0.2% ALOE in the diet were given for 15 weeks. In Experiment 1, the tumor incidence and tumor multiplicity (tumors per mouse) of the duodenum in the ENNG + 10% ALOE group were significantly decreased compared with that in the ENNG alone group. Erythrocyte polyamine levels in the ENNG + 10% ALOE group were also significantly decreased. In Experiment 2, the incidence of duodenal tumors in the ENNG + 5% ALOE group were significantly decreased compared with that in the ENNG alone group. These results indicated that ALOE, especially at 10% in the diet, inhibits ENNG-induced duodenal tumorigenesis in mice.

Aloe arborescens extract inhibits TPA-induced ear oedema, putrescine increase and tumour promotion in mouse skin

The ethyl acetate extract of the acetone-soluble Aloe arborescens fraction was found to inhibit 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced ear oedema, putrescine increase and tumour promotion in mouse skin. Chromatographic analyses of this extract revealed that phenolic compounds such as aloenin, barbaloin and isobarbaloin could be useful as cancer chemopreventive agents against tumour promotion.

Chemopreventive effects of Aloe arborescens on N-nitrosobis(2-oxopropyl)amine-induced pancreatic carcinogenesis in hamsters

The modification effects of freeze-dried aloe (Aloe arborescens) whole leaf powder during the initiation phase of carcinogenesis were investigated in hamsters treated with N-nitrosobis(2-oxopropyl)amine (BOP). Female Syrian hamsters were given four weekly subcutaneous injections of BOP at a dose of 10mg/kg and then given 0, 1 or 5% aloe in their diet for 5 weeks. At week 54 of the experiment, all surviving animals were sacrificed and development of neoplastic and preneoplastic lesions was assessed histopathologically. The incidences of pancreatic adenocarcinomas, atypical hyperplasias or total atypical hyperplasias plus adenocarcinomas were significantly (P<0.05) decreased with BOP+5% aloe, and that of adenocarcinomas were also significantly (P<0.05) reduced in the BOP+1% aloe as compared to the BOP alone group. Multiplicities of pancreatic adenocarcinomas, atypical hyperplasias or total lesions were also significantly (P<0.01 or P<0.05) lower in the BOP+5% aloe group than with the BOP alone. Quantitative data for neoplastic lesions in the lung, liver, gall bladder, kidney and urinary bladder of hamsters were not significantly different among the three groups. In a satellite experiment, pretreatment with aloe significantly (P<0.01) reduced the formation of O6-methyldeoxyguanosine in epithelial cells of pancreatic ducts as compared to the BOP alone value. Our results thus indicate that aloe prevents BOP-induced pancreatic neoplasia in hamsters in relation to decreased DNA adduct formation in the target tissue.

Inhibition of azoxymethane-induced aberrant crypt foci formation in rat colorectum by whole leaf Aloe arborescens Miller var. natalensis Berger

We examined the modifying effect of whole-leaf Aloe arborescens Miller var. natalensis Berger (designated as 'ALOE') on azoxymethane (AOM)-induced aberrant crypt foci (ACF), putative preneoplastic lesions, in the rat colorectum. Male F344 rats (4 weeks old) were fed the basal diet, or experimental diets containing 1% or 5% ALOE for 5 weeks. One week later, all rats except those in the vehicle-treated groups were injected s.c. with AOM (15 mg/kg, once weekly for 3 weeks). At 9 weeks of age, all the rats were killed, and the colorectum and liver were evaluated for ACF and cytosolic quinone reductase (QR; a phase 2 enzyme), respectively. In rats given AOM and ALOE (1% or 5% in diet) the numbers of ACF/colorectum, aberrant crypts/colorectum, aberrant crypts/focus and large ACF/colorectum were significantly decreased compared with those of rats given AOM alone (all p < 0.01). No ACF were found in rats treated without AOM. In addition, ALOE significantly increased cytosolic QR activity in the liver (p < 0.01). These results indicated that ALOE inhibited the development of AOM-induced ACF in the rat colorectum, with increased QR activity in the liver, and therefore suggested that ALOE might have a chemopreventive effect against colon carcinogenesis at least in the initiation stage.

Determination of aloenin, barbaloin and isobarbaloin in aloe species by micellar electrokinetic chromatography

Aloenin, barbaloin and isobarbaloin in JP Aloe, Aloe barbadensis (Aloe vera) and Aloe arborescens Miller var. natalensis Berger (Aloe arborescens Miller) were determined by micellar electrokinetic chromatography (MEKC) with 50 mM sodium dodecyl sulfate. Aloenin, barbaloin and isobarbaloin were well separated by MEKC and as little as 5.5 pg/11 nl of the three compounds could be detected. The determination took around 14 min.

Hgs (Hrs), a FYVE domain protein, is involved in Smad signaling through cooperation with SARA

Smad proteins are effector molecules that transmit signals from the receptors for the transforming growth factor beta (TGF-beta) superfamily to the nucleus; of the Smad proteins, Smad2 and Smad4 are essential components for mouse early embryogenesis. We demonstrated that Hgs, a FYVE domain protein, binds to Smad2 in its C-terminal half and cooperates with another FYVE domain protein, the Smad anchor for receptor activation (SARA), to stimulate activin receptor-mediated signaling through efficient recruitment of Smad2 to the receptor. Furthermore, a LacZ knock-in allele of the C-terminal half-deletion mutant of mouse Hgs was created by gene targeting. The introduced mutation causes an embryonic lethality between embryonic days 8.5 and 10.5. Mutant cells showed significantly decreased responses to stimulation with activin and TGF-beta. These findings suggest that the two FYVE domain proteins, Hgs and SARA, are prerequisites for receptor-mediated activation of Smad2.

BMP type II receptor is required for gastrulation and early development of mouse embryos

Bone morphogenetic proteins (BMPs), members of the transforming growth factor-beta superfamily, play a variety of roles during mouse development. BMP type II receptor (BMPR-II) is a type II serine/threonine kinase receptor, which transduces signals for BMPs through heteromeric complexes with type I receptors, including activin receptor-like kinase 2 (ALK2), ALK3/BMPR-IA, and ALK6/BMPR-IB. To elucidate the function of BMPR-II in mammalian development, we generated BMPR-II mutant mice by gene targeting. Homozygous mutant embryos were arrested at the egg cylinder stage and could not be recovered at 9.5 days postcoitum. Histological analysis revealed that homozygous mutant embryos failed to form organized structure and lacked mesoderm. The BMPR-II mutant embryos are morphologically very similar to the ALK3/BMPR-IA mutant embryos, suggesting that BMPR-II is important for transducing BMP signals during early mouse development. Moreover, the epiblast of the BMPR-II mutant embryo exhibited an undifferentiated character, although the expression of tissue-specific genes for the visceral endoderm was essentially normal. Our results suggest that the function of BMPR-II is essential for epiblast differentiation and mesoderm induction during early mouse development.

[Hypereosinophilic syndrome associated with antineutrophil cytoplasmic antibody]

A 68-year-old man was admitted to our hospital with complaints of fever, cough, and shortness of breath. He had several erythematous maculae on the trunk and experienced hypesthesia in his lower extremities. Laboratory data showed marked eosinophilia (20,235/mm3) and enhanced hepatobiliary enzymes. Chest X-ray films and computed tomographic scans revealed diffuse patchy infiltrative changes in the lungs. Histologic findings confirmed eosinophilic infiltration of the skin, liver, and lungs. A diagnosis of hypereosinophilic syndrome (HES) was made in accordance with clinical criteria proposed by Chusid et al. The patient was positive for antineutrophil cytoplasmic antibodies (a marker for vasculitis). This suggested a clinical picture resembling Churg-Strauss syndrome (CSS) despite the lack of bronchial asthma. The findings in this report could contribute to a better understanding of the diversity of HES cases, several of which are considered to represent a continuum of pathologies sharing an etiology similar to that of CSS.

[Pneumonitis induced by the drug ougon]

We report a case of drug-induced pneumonitis associated with the herbal medications Sho-saiko-to and Ouren-gedoku-to. A 62-year-old man experienced fever and dry cough after using Ouren-gedoku-to for 2 months. He was admitted to our hospital because a subsequent 5-day course of Sho-saiko-to for suspected bronchitis aggravated these symptoms and caused exertional dyspnea. Chest X-ray films revealed a ground-glass appearance in both lower lung fields. Cessation of these medications improved the patient's clinical and X-ray findings. Bronchoalveolar lavage showed an increase in lymphocytes with a decreased CD 4/CD 8 ratio. While drug-induced lymphocyte stimulation tests gave negative results, challenge tests for Ouren-gedoku-to and Sho-saiko-to were both positive. A diagnosis of drug-induced pneumonitis was made. Our findings suggested the involvement of Ougon, the only common ingredient in the two medications.

Drosophila dSmad2 and Atr-I transmit activin/TGFbeta signals

BACKGROUND

Much is known about the three subfamilies of the TGFbeta superfamily in vertebrates-the TGFbetas, dpp/BMPs, and activins. Signalling in each subfamily is dependent on both shared and unique cell surface receptors and Smads. In invertebrates, mutants for BMP pathway components have been extensively characterized, but thus far, evidence for an activin- or TGFbeta-like pathway has been lacking, preventing the use of the extensive genetic tools available for studying several key issues of TGFbeta signalling.

RESULTS

Here we report the identification of dSmad2, a new Drosophila Smad which is most related to the activin/TGFbeta-pathway Smads, Smad2 and Smad3. We show that dSmad2 induces activin responsive genes in Xenopus animal cap assays. dSMAD2 is phosphorylated by ATR-I and PUNT, but not by activated THICK VEINS, and translocates to the nucleus upon activation. Furthermore, we show that dSMAD2 complexes with MEDEA only in the presence of ATR-I and PUNT. dSmad2 is expressed in the imaginal disks and in the outer proliferation centre of the larval brain, suggesting that it may have important proliferative and patterning roles during Drosophila development.

CONCLUSION

Our data provide evidence for the existence of an activin/TGFbeta pathway in Drosophila. We show that dSmad2 participates in this pathway, and that it functions with Atr-I and punt. We show that Medea also participates in this pathway, indicating the conservation of roles for Co-Smads in diverse phyla. Expression patterns of dSmad2 suggest that it functions in imaginal disks and in the brain, in tissues that undergo extensive patterning and proliferation.

[Chronic hypersensitivity pneumonitis due to isocyanate in a patient presenting with acute symptoms 1 month after environmental exposure]

A 51-year-old man who had been working for 10 years with polyurethane paint containing isocyanate (MDI) was admitted to our hospital with complaints of fever and exertional dyspnea. Fine crackles were heard in both bases, and the patient had clubbed fingers. A chest X-ray film and computed tomograms of the lungs revealed patchy infiltrative shadows in both lung fields and subpleural honeycombing associated with irregular linear areas. Examination of bronchoalveolar lavage fluid showed increased T lymphocytes and a decreased CD 4/8 ratio. Specimens obtained by transbronchial lung biopsy revealed lymphoplasmacytic infiltration into the thickened alveolar walls, macrophage accumulation, and micro-epithelioid cell granulomas in the alveolar sacs. Hypersensitivity pneumonitis was suspected although the causative antigen was not identified because the results of short-term environmental provocation tests were negative in the patient's home and workplace. After discharge, the patient continued working as a paint sprayer. His acute symptoms recurred 1 month after exposure to isocyanate. Similar episodes occurred on two separate occasions. In addition, the patient tested positive for antibody to MDI-HSA in bronchoalveolar fluid. From the above observations, the patient was given a diagnosis of chronic hypersensitivity pneumonitis due to isocyanate (MDI). This condition is extremely rare. Furthermore, it is interesting that acute symptoms recurred 1 month after environmental exposure to the causative antigen.

Blood-nerve barrier in IgM paraproteinemic neuropathy: a clinicopathologic assessment

We report the pathologic findings in a patient with sensorimotor neuropathy associated with Waldenström's macroglobulinemia, particularly in relation to blood-nerve barrier defects. The monoclonal IgM was of kappa type and possessed anti-HNK-1 activity. A sural nerve biopsy specimen revealed severe loss of myelinated and unmyelinated nerve fibers and gaps between adjacent endothelial cells of small endoneurial vessels. Postmortem findings 3 years later included severe loss of myelinated nerve fibers and diffuse infiltration by lymphoplasmacytic B cells throughout the peripheral nervous system, sparing the central nervous system. Findings in this case suggest an immune attack against endoneurial endothelial cells with permeation of IgM into peripheral nerve tissue.

Atrophy of the cerebellum and brainstem in dentatorubral pallidoluysian atrophy. Influence of CAG repeat size on MRI findings

To elucidate how the size of the expanded CAG repeat of the gene for dentatorubral pallidoluysian atrophy (DRPLA) and other factors affect the atrophy of the brainstem and cerebellum, and the appearance of high-intensity signals on T2-weighted MRI of the cerebral white matter of patients with DRPLA, we quantitatively analyzed the MRI findings of 26 patients with DRPLA, the diagnosis of which was confirmed by molecular analysis of the DRPLA gene. When we classified the patients into two groups based on the size of the expanded CAG repeat of the DRPLA gene (group 1, number of CAG repeat units > or = 66; group 2, number of CAG repeat units < or = 65), we found strong inverse correlations between the age at MRI and the areas of midsagittal structures of the cerebellum and brainstem in group 1 but not in group 2. Multiple regression analysis, however, revealed that both the patient's age at MRI and the size of the expanded CAG repeat correlated with the areas of midsagittal structures. Involvement of the cerebral white matter as detected on T2-weighted images was observed more frequently in patients belonging to group 2 than in group 1 patients. Furthermore it was demonstrated that high-intensity signals can be detected on T2-weighted images of the cerebral white matter of patients with a largely expanded CAG repeat (group 1) in their thirties. These results suggest that patient age as well as the size of the expanded CAG repeat are related to the degree of atrophy of the brainstem and cerebellum, and the white matter changes in patients with DRPLA.

[An elderly woman with chronic pigeon-breeder's disease]

A 64-year-old woman had been feeding more than 60 pigeons in a coop in her back yard for 35 years. Diffuse reticulonodular shadows were found on a chest radiograph obtained as part of an annual check-up eight years before admission to the hospital. She was given a tentative diagnosis of idiopathic pulmonary fibrosis and was observed. She was admitted to our hospital because she noticed dry coughing and shortness of breath. A chest CT scan revealed segmentally distributed honeycombing and bronchi-bronchioloectasis. Tests for IgA and IgG antibodies to extracts of pigeon droppings in serum samples and in samples of bronchoalveolar lavage fluid were strongly positive, as were tests for lymphocyte blastogenic responses to samples of pigeon serum Examination of lung-biopsy specimens obtained by video-assisted thoracoscopic surgery revealed bronchiolitis, alveolitis, and honeycombing in a centrilobular distribution. The patient was given a diagnosis of pigeon-breeder's disease. Chronic hypersensitivity pneumonitis without acute episodes might be misdiagnosed as idiopathic interstitial pneumonia or bronchiectasis, as happened in this case. The possibility of chronic hypersensitivity pneumonitis should be considered when patients are suspected to have pulmonary fibrosis. It is important to obtain the detailed information on past or current avian contact, working history, and the home environment.

cDNA cloning and genomic organization of the mouse BMP type II receptor

The cDNA for the mouse bone morphogenetic protein type II receptor (BMPR-II) was isolated using the human counterpart as a probe and its genomic structure was determined. The cDNA encodes a protein of 1,038 amino acids with a single transmembrane domain, a serine/threonine kinase domain, and a long carboxy-terminal tail. The overall amino acid sequence identity between the mouse and the human BMPR-II is 96.6%. mRNA is widely distributed in various adult tissues. The gene is encoded by 13 exons spanning over 80 kb. Two large introns (intron 1 and 3) contribute to the majority of the gene size, as in the mouse activin type II receptor gene. The intron/exon boundaries were sequenced. The results suggest that alternative splicing can yield a shorter form of BMPR-II of 530 amino acids, as reported previously. Knowledge of the structure of the BMPR-II gene is essential for the understanding of the role of bone morphogenetic proteins in the developmental and physiological processes of animals.

Recurrent histiocytic necrotizing lymphadenitis (Kikuchi's disease) in an human T lymphotropic virus type I carrier

We describe a case of recurrent histiocytic necrotizing lymphadenitis (HNL) with aseptic meningitis. The patient was a 46-year-old male and a carrier of human T lymphotropic virus type I (HTLV-I). The patient had a past medical history of at least three relapses of HNL. In addition, his sister, who was also an HTLV-I carrier, had recurrent clinical episodes consistent with those of HNL, suggesting familial HNL occurrence. This observation suggests the possibility that HTLV-I infection is relevant to the pathogenesis of HNL.

Ceramide-induced nuclear translocation of NF-kappa B is a potential mediator of the apoptotic response to TNF-alpha in murine clonal osteoblasts

Osteoblasts are affected by TNF-alpha overproduction by immune cells during inflammation. We demonstrate that apoptosis is induced in murine osteoblastic MC3T3-E1 cells by exceeding the concentrations 100 units/mL of TNF-alpha and 10 mumol/L of synthetic ceramide. The apoptotic signaling pathway activated by TNF-alpha was examined in MC3T3-E1 cells. Endogenous cellular ceramide concentrations increased within 3 min, and comparable peak levels were observed for 30 min after TNF-alpha treatment. Activation of nuclear factor-kappa B (NF-kappa B) was detected after TNF-alpha or synthetic ceramide stimulation. The concentration of NF-kappa B increased in the perinuclear region after 5 min of treatment and translocation into the nucleus was observed within 15 min of treatment. Degradation of I kappa B alpha/MAD-3 was observed after 60 min of ceramide treatment. These results indicate that nuclear translocation and activation of NF-kappa B through TNF-alpha generated ceramide may be one important apoptotic signaling pathway in MC3T3-E1 cells. The osteoblastic apoptosis triggered by TNF-alpha-generated ceramide may explain the inhibition of bone formation during severe bone inflammation.

[Expression of Mn-SOD mRNA in streptozotocin-induced diabetic rat cornea by in situ hybridization]

The pathogenesis of diabetic corneal epitheliopathy, one of the ocular complications frequently seen in diabetes patients, still remains to be elucidated. Hyperglycemia causes glycation of various proteins leading to the formation of superoxide radicals (O2.-). Copper, zinc-superoxide dismutase (Cu, Zn-SOD), a scavenger of superoxide radicals, whose function is complementary to manganese-SOD (Mn-SOD), is inactivated during glycation. As a first step to clarify whether depressed antioxidant activity is associated with diabetic corneal epitheliopathy or not, we investigated the expression of Mn-SOD mRNA (messenger ribonuclic acid) in streptozotocin-induced diabetic rat cornea by in situ hybridization using a digoxigenin-labeled Mn-SOD cDNA probe. Mn-SOD mRNA was detected in epithelial cell layer and endothelial cell layer of both diabetic rat cornea and normal rat cornea. However, the expression of Mn-SOD mMRA in the epithelial cell layer of diabetic rat cornea was weaker than that of normal rat cornea. These results suggest that decreased Mn-SOD activity might be one of factors causing diabetic corneal epitheliopathy.

Decreased levels of 2-amino-3-methylimidazo[4,5-f]quinoline-DNA adducts in rats treated with beta-carotene, alpha-tocopherol and freeze-dried aloe

To assess mechanisms of chemoprevention of hepatocarcinogenesis by trans-beta-carotene (beta-C), DL-alpha-tocopherol (alpha-T), and freeze-dried whole leaves of Kidachi aloe (Aloe), formation of 2-amino-3-methylimidazo[4,5-f]quinoline (IQ)-DNA adducts was measured by 32P-post-labeling analysis, and CYP1A1 and CYP1A2 protein levels were analyzed by ELISA. Group 1 rats were fed diet containing 0.02% beta-C, 1.5% alpha-T or 30% Aloe over an 8-day period, while group 2 was given basal diet alone. On day 7, all animals were subjected to two-thirds partial hepatectomy (PH). Twelve hours after PH, they received a single dose of the carcinogenic food pyrolysate IQ (100 mg/kg) intragastrically, to initiate hepatocarcinogenesis. Rats were killed 6, 12, 24 and 48 h after IQ administration. The levels of adducts, expressed as relative adduct labeling values in rats treated with beta-C, alpha-T and Aloe, were decreased as compared with the control group at hour 24 (36 h after PH), with a significant difference in the case of the beta-C group (46.4% of the control value). Similarly, all showed a tendency for decrease at hour 48. Furthermore, the levels of CYP1A2, known to be responsible for activation of IQ, showed a significant reduction at hour 24. It is concluded that beta-C, and possibly also alpha-T and Aloe, have the potential to reduce IQ-DNA adduct formation, presumably as a result of decreased formation of active metabolites. The results may explain, at least in part, the previously observed inhibitory effects of these compounds on induction of preneoplastic hepatocellular lesions.

The case of contaminated blood products in Japan

One of the respondents to the ISDB study described by Danielle Bardelay in the previous article dealt with the situation in Japan. The information on the infection of hemophiliacs with HIV through contaminated blood products is included here as a separate paper. It provides a case study both of the extent to which lack of transparency can contribute to a damaging lack of accountability and of the way in which this case has forced a discussion on how regulatory agencies can be made more accountable and more open to public scrutiny and audit.

A 35 kDa mannose-binding lectin with hemagglutinating and mitogenic activities from "Kidachi Aloe" (Aloe arborescens Miller var. natalensis Berger)

A novel lectin was isolated from the leaf skin of "Kidachi Aloe" (Aloe arborescens Miller var. natalensis Berger) by sequential chromatographies on Sephadex G-25 gel filtration, DEAE ion exchange, and Superdex 75 gel filtration columns. The native lectin exhibited a molecular mass of about 35 kDa on both gel filtration on a Superdex 75 column and native-PAGE under nonreducing conditions. SDS-PAGE in the presence or absence of beta-mercaptoethanol revealed two distinct peptides with molecular masses of about 5.5 and 2.3 kDa, respectively, in addition to a major 9.2 kDa subunit, indicating the presence of a partially processed subunit. The N-terminal amino acid sequence of the intact subunit showed homology with that of snowdrop lectin. The native lectin showed hemagglutinating activity toward rabbit but not human and sheep erythrocytes, and specifically bound to mannose like snowdrop lectin did, indicating that the Aloe and snowdrop lectins are structurally and functionally similar proteins. In addition, the native lectin showed strong mitogenic activity toward mouse lymphocytes.