Temporal variabilities of the concentrations of intra- and extracellular microcystin and toxic Microcystis species in a hypertrophic lake,Lake Suwa,Japan (1991–1994)

Temporal variability in the concentration of toxic heptapeptide microcystin was studied during the warm season of four years (1991–1994) in a hypertrophic lake (Lake Suwa) in central Honshu, Japan. Lake water samples (ca. 5 L) were filtered to separate intracellular microcystin (cell fraction) from extracellular microcystin (filtered lake water fraction). These fractions were analyzed to measure the total quantity of microcystin in lake water. Total amounts of extra- and intracellular microcystin were measured with high performance liquid chromatography. Concentrations of intracellular microcystin usually exceeded concentrations of extracellular microcystin (24 out of 26 times). High concentrations of intracellular microcystin were found during the exponential growth phase of the blooms, whereas concentrations of extracellular microcystin were highest at the end of the blooms. However, concentrations of extracellular microcystin remained very small (<4μg/L) compared to the levels of intracellular microcystin. The relatively higher percentages of microcystin in filtered lake water ( > 20%) at the end of blooms suggests that release of microcystin from cells occurs during senescence and the decomposition period of Microcystis cells. © 1998 John Wiley & Sons, Inc. Environ Toxicol Water Qual 13 : 61–72, 1998     

Hepatotoxic microcystins and neurotoxic anatoxin-a in cyanobacterial blooms from Korean lakes

Cyanobacterial bloom samples were collected in the warm season during 1992–1995 from the 12 lakes in Korea. Six species each of Microcystis and Anabaena, and two of Oscillatoria were identified in these lakes. The cyanotoxins of 47 samples collected from the lakes were identified as microcystins-RR, -YR, -LR; desmethyl-7-microcystin-LR (7-DMLR), plus anatoxin-a. Microcystins were the main components of these cyanotoxins, while anatoxin-a was detected in samples from a few lakes. Thirty-four of the 47 samples, included microcystins and the total amounts of microcystin ranged between 20–1500 μg/g freeze-dried bloom material. In four of the 26 samples, the samples contained anatoxin-a, though the amounts varied. The total microcystin concentration in 30 samples from the lakes was equal to the cellular microcystin in these lakes because no extracellular microcystin was detected. All the lakes except for Lakes Younglang and Mijae are a source of drinking water, so the presence of cyanotoxin can be a potential threat and requires more attention to water treatment. © 1998 John Wiley & Sons, Inc. Environ Toxicol Water Qual 13: 225–234, 1998     

Diabetes mellitus not an unfavorable factor on the prognosis of hepatitis C virus‐related hepatocellular carcinoma

Aim

Diabetes mellitus (DM) is a potential risk factor for hepatocarcinogenesis, especially in patients with hepatitis C virus (HCV) infection. We aimed to elucidate whether DM influences the surgical outcomes of patients with hepatocellular carcinoma (HCC).

Methods

Our patients were routinely controlled to keep urinary glucose excretion to less than 3.0 g/day before surgery, and the serum glucose level under 200 mg/dL after surgery. The surgical outcomes and postoperative complications of 112 patients with HCV‐related HCC with DM (DM group) were compared to those of 112 propensity‐matched patients without DM (non‐DM group).

Results

After a median follow‐up of 3.2 years (range, 0.2–11.3 years), the median overall (5.2 years; 95% confidence interval, 3.8–6.5 years) and recurrence‐free survival (2.2 years; 1.7–2.9 years) in the DM group were not significantly different from those (6.3 years; 5.4–7.1 years, P = 0.337; and 2.2 years; 1.7–3.6 years, P = 0.613) in the non‐DM group. The independent factors related to overall survival were the background liver (hazard ratio, 2.06; 95% confidence interval, 1.27–3.39, P = 0.014) and tumor differentiation grade (2.07; 1.14–4.05, P = 0.015). Thirty‐two patients (28.5%) in the DM group and 32 patients (28.5%) in the non‐DM group had morbidities after operation, with no significant difference between the groups (P = 1.000). Furthermore, postoperative control status of DM did not affect the prognostic outcome.

Conclusion

Diabetes mellitus does not affect the surgical outcomes of patients with HCV‐related HCC, and it is not an unfavorable factor when selecting candidates for liver resection of HCC.     

Enhancement of reactive oxygen species and induction of apoptosis in streptozotocin-induced diabetic rats under hyperbaric oxygen exposure

An important source of reactive oxygen species (ROS) production is nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, which on activation induces superoxide production via oxidation in the mitochondria, inflammation and stress; such ROS are implicated in the pathogenesis of diabetic complications, including neuropathy. Hyperbaric oxygen (HBO) treatments are applied various diseases including diabetic patients with unhealing foot ulcers, however, and also increases the formation of ROS. In a previous study, we showed that a clinically recommended HBO treatment significantly enhanced oxidative stress of pancreatic tissue in the diabetic rats. However, no study has been undertaken with regard to the effects of HBO on the activity and gene expression of the NADPH oxidase complex and on apoptosis in the pancreas of diabetic animals. The purpose of this study was to investigate the effect of HBO exposure on gene expression of the NADPH complex, and pancreatic expression of genes related to apoptosis via the mitochondria, using the NADPH oxidase inhibitor apocynin. The mRNA expression of genes related to NADPH oxidase complex and apoptosis increased significantly (P < 0.05) in the pancreas of diabetic rats under HBO exposure. Similarly, activities of NADPH oxidase and caspase-3 changed in parallel with mRNA levels. These results suggest that oxidative stress caused by HBO exposure in diabetic animals induces further ROS production and apoptosis, potentially through the up-regulation of NADPH oxidase complex. Thus, this study can contribute to development of a better understanding of the molecular mechanisms of apoptosis via the mitochondria in diabetes, under HBO exposure.     

EGD1 (β-NAC) mRNA is localized in a novel cytoplasmic structure in Saccharomyces cerevisiae

RNA localization is a common mechanism for recruiting proteins to specific regions of a cell, which causes cell polarization and sometimes asymmetric division. We found that EGD1 mRNA accumulates dose-dependently as a cytoplasmic granule in Saccharomyces cerevisiae. EGD1 encodes a β-subunit of the nascent polypeptide-associated complex (NAC). NAC is a heterodimer consisting of α- and β-subunits, associated with ribosomes and thought to be involved in the folding of nascent polypeptide chains. Analysis of deletion constructs showed that the localization of EGD1 mRNA requires both an upstream region and an ORF of EGD1, suggesting that the translation of Egd1p is important for localization. We also showed that Egd1p and P-body components are co-localized with EGD1 mRNA. This granule, named the EGD1 granule, has features similar to cellular inclusions containing aggregated proteins. Disruption of microtubules by treatment with a drug, benomyl, resulted in loss of the EGD1 granule. When the expression level of EGD2 encoding the αNAC increased, the percentage of cells showing the EGD1 granule decreased, suggesting that the granular distribution of EGD1 depends on the quantitative balance between α- and β-subunits of NAC. Taken together, we propose a novel microtubule-dependent mechanism for controlling NAC through RNA localization.     

Case report of transarterial chemoembolization to lymph node metastasis of hepatocellular carcinoma

We performed transarterial chemoembolization (TACE) on the 67-year-old man who had hepatectomy for hepatocellular carcinoma with hepatitis C, recurrence in the liver and lymph nodes.The metastasis in lymph node did not show a clear increase until dying, and TACE showed the possibility of one treatment method to the metastasis in lymph node of the hepatocellular carcinoma.     

Component-dependent urine responses in the rat accessory olfactory bulb

To investigate how pheromonal information is processed in the rat accessory olfactory bulb, we optically imaged intrinsic signals to obtain high-resolution maps of activation induced by urinary stimulation. Application of volatile components in male urine mainly induced activation in the anterior accessory olfactory bulb, irrespective of the sex, whereas volatile female urine elicited activation not only in the anterior but also to some extent in the caudal part of the posterior accessory olfactory bulb of male, but not female, rats. Nonvolatile components of both male and female urine induced activation mainly in the rostral part of the posterior and to a lesser extent in the anterior accessory olfactory bulb, irrespective of the sex. These results indicate that volatile and nonvolatile urinary components activate the anterior and posterior subdivisions of the accessory olfactory bulb, respectively.     

Cytokine production by keratinocytes and mononuclear infiltrates in oral lichen planus

Cytokine generation by tissue-infiltrating mononuclear cells (TIMC) and by keratinocytes (KC) was investigated in material obtained from the oral mucosal tissues of patients with oral lichen planus (OLP). Peripheral blood mononuclear cells (PBMC) and chronically inflamed and noninflamed gingival KC (CIG-KC, NOR-KC, respectively) were used as the controls. Compared to NOR-KC and CIG-KC, KC from OLP patients (OLP-KC) produced much more interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α) and granulocyte-macrophage colony-stimulating factor (GM-CSF). The OLP-KC superiority in the production of these cytokines was more prominent when the KC were cultured in the presence of interleukin-l beta (IL-1β), lipopolysaccharide and phorbol myristate acetate. OLP-KC also produced more monocyte-chemotactic factor(s) which were not inactivated by the antibodies against GM-CSF, macrophage colony-stimulating factor and monocyte chemoattractant protein-1. TIMC in OLP tissues (OLP-TIMC) were superior to PBMC in the generation of IL-6 and GM-CSF. OLP-TIMC were stimulated to produce more TNF-a by IL-1β, IL-6 and GM-CSF, more IL-6 by IL-1β and GM-CSF, and more GM-CSF by IL-1β and IL-6 than PBMC. When compared to cytokine generation in TIMC from the chronically inflamed gingivae, more interferon-gamma, IL-6 and TNF-α were generated by OLP-TIMC. These results indicate that KC play a critical role in OLP, producing cytokines including monocyte-chemotactic factor(s), and that the cytokines produced by TIMC and OLP-KC through autocrine and paracrine processes enhance the local inflammatory response.     

Clinico-pathologic studies on post-operative maxillary cysts

Microscopic and clinical observations on 70 post-operative maxillary cysts were performed. Cysts of 47 cases were lined with the ciliatal epithelium, and 12 cases were composed of both squamous and ciliated cells. Squamous only and cuboidal lining were found in 9 and 2 cases, respectively. Duration after the antrum operation and the non-vital tooth related to the cyst did not affect the epithelial type, though many of the cases of squamous epithelium possessed infectious histories. From the results, the squamous change seemed to be accelerated by inflammatory irritations, and mucous cells in the lining epithelium were depleted as a part of the metaplastic sequence.     

细胞角蛋白18和13在术后性上颌囊肿化生上皮中的表达

目的研究口腔术后性颌骨囊肿（POMC）化生上皮起源以及细胞角蛋白（CK）在鳞状化生细胞中的表达.方法采用免疫组化SP法、原位杂交法和RT-PCR法,分别检测46例POMC中细胞角蛋白的表达情况.其中13例囊肿衬里上皮只含有假复层纤毛柱状上皮细胞;30例囊肿衬里既含有纤毛柱状上皮细胞,又含化生的鳞状上皮细胞;3例囊肿衬里只含有化生的鳞状上皮细胞.结果43例纤毛柱状上皮细胞中,39例表达CK8,9例表达CK13,43例均有CK18表达.发生鳞状上皮化生的细胞中CK13表达较多,CK8和CK18表达较少.在33例发生化生的囊肿衬里中,24例表达CK8,23例表达CK13,26例表达CK18.CK13和CK18蛋白的表达与CK13、CK18-mRNA表达水平相关.原位杂交方法检测CK1g-mRNA表达时发现,26例CK18蛋白阳性的化生囊肿衬里上皮以及7例发生化生但不表达CK18蛋白的囊肿衬里上皮都有CK18-mRNA的表达.RT-PCR结果进一步证明所有发生鳞状化生的囊肿衬里上皮都有CK18-mRNA的表达,但是其表达水平较未发生化生的柱状细胞囊肿衬里上皮弱,而且CK13-mRNA的表达与CK18-mRNA表达相反.结论在发生上皮化生的全过程中,CK18-mRNA保持不变,但是其蛋白的表达水平下降,而且发生鳞状化生时CK18表达减少,CK13表达增加.