Enhancing effects of (2S,3S,4R)-1-O-(alpha-D-galactopyranosyl)-2-(N-hexacosanoylamino) -1,3,4-octadecanetriol (KRN7000) on antigen-presenting function of antigen-presenting cells and antimetastatic activity of KRN7000-pretreated antigen-presenting cells

(2S,3S,4R)-1-O-(alpha-D-galactopyranosyl)-2-(N-hexacosanoylamino)- 1,3, 4-octadecanetriol (KRN7000), with an alpha-galactosylceramide structure, is an immunomodulator showing potent antimetastatic activities. In an in vitro study, KRN7000 potently stimulated proliferation and enhanced natural killer activity in spleen cells from BALB/c euthymic mice, but not BALB/c athymic (nu/nu) mice, suggesting that T cells play an important role in these activities. To study the detailed immunostimulatory mechanisms of KRN7000, syngeneic mixed leukocyte reactions were then performed using dendritic cell-enriched fractions (DCEFs) from spleens of BALB/c euthymic and athymic mice. In these studies, KRN7000 enhanced the antigen-presenting cell activities of the DCEFs. In addition, marked production of interleukin-2 and interferon-gamma in BALB/c euthymic mice was observed following treatment with KRN7000 in vitro and in vivo. Because of these strong immunostimulating effects of KRN7000, its antimetastatic effects were also evaluated. Adoptively transferred KRN7000-treated DCEF markedly prolonged the survival time of mice bearing B16 pulmonary metastases. These results demonstrate that KRN7000 may be useful for cancer therapy not only as an antitumor agent but also as an activator of antigen-presenting cells such as dendritic cells, which can be used for adoptive cellular therapy.

Immunohistochemical localisation of aromatase and its correlation with progesterone receptors in ovarian epithelial tumours

Aromatase cytochrome P-450 was immunohistochemically localised exclusively in the cytoplasm of neoplastic cells of benign and malignant nonfunctional ovarian tumours, whilst (progesterone receptors (PR) and estrogen receptors) (ER) were localised exclusively inn the nuclei of neoplastic cells. Aromatase activity and PR were detected in 68% (17/25) and 32% of the malignant tumours and 82% (22/27) and 67% of the benign tumours, respectively. In postmenopausal tumours, the positivity for PR in malignant tumours was less frequent (p < 0.01) than that in benign tumours. The tumours in which both aromatase and PR were positive, were less frequent (p < 0.05) in malignant than in benign tumours. Aromatase activity was detected in 100% (8/8) of the PR-positive tumours but in only 68% (9/17) of the PR-negative tumours. With postmenopausal malignant tumours, there was a positive correlation between aromatase activity and PR level (r = 0.77, p < 0.001). However, there was no significant difference in the positivity of ER. The serum steroid levels did not correlate with the tumour levels of aromatase activity, PR or ER. These findings suggest that aromatase activity is correlated with PR in ovarian tumours of postmenopausal women. In addition to steroid receptor status, aromatase activity may be a useful factor in ovarian cancer.

Association of tumor cell proliferation with lymph node metastasis in early gastric cancer

Recently, many studies have reported on the relationship between malignant potential of neoplasms and cell proliferation. Proliferating cell nuclear antigen (PCNA) is an auxiliary protein of DNA polymerase delta and is considered to correlate with the cell's proliferative state. In this study, we investigated the correlation between tumor cell proliferation and nodal status of early gastric carcinoma. One hundred two endoscopically biopsied specimens from patients with early gastric carcinoma prior to operation were investigated by an immunohistochemical study, using anti-PCNA monoclonal antibody. Correlation of PCNA labeling index (percentage of positive cells per over 500 tumor cells) with nodal status were studied. PCNA labeling index in patients with lymph node metastasis was significantly higher in those without metastasis. Moreover, multivariate analysis indicated that PCNA labeling index is an independent significant factor for lymph node metastasis. As a result of this study, PCNA labeling index was suggested to be effective as one of the predictors of lymph node metastasis.

Advanced glycation end-products in diabetic nephropathy

Advanced glycation end-products (AGEs) are the pigmented and fluorescent adduct formed by a non-enzymatic reaction between sugar and protein. Since AGEs are generated in high glucose milieu, then induce the structural and functional alteration of matnx proteins, and have biological effects on various kinds of cells including mesangial cells, AGEs have been implicated in tissue damage of diabetic nephropathy. To elucidate the factor(s) that determine the AGEs level in diabetic nephropathy, we quantitated the plasma pentosidine level of different status of diabetic nephropathy by HPLC assay. The plasma pentosidine level in diabetic nephropathy was found to be determined by factors such as renal function control of glucose and the patient's age; of these, renal function was the most critical factor. For a better understanding of the pathological role of AGEs in diabetic nephropathy, we then examined renal tissues of diabetic nephropathy immunohistochemically using antibodies specific for AGE proteins. Immunohistochemistry revealed the positive immunostaining for AGEs in the expanded mesangial area of diffuse diabetic glomerulosclerosis. The degree of staining was stronger than that in patients of IgA nephropathy with a similar degree of mesangial expansion. The nodular lesions, characteristic of diabetic nephropathy, were also stained positive for AGEs. These findings suggests a potential link of AGEs accumulation, which may be determined by renal function, control of glucose and age, to renal tissue damage in diabetic nephropathy.

Identification and nucleotide sequence of the thymidine kinase gene of canine herpesvirus

This paper presents the entire nucleotide sequence of the thymidine Kinase (TK) gene of canine herpesvirus (CHV). The gene was located within a 2.1 kbp EcoRV fragment by Southern-blot hybridization with a probe derived from the known feline herpesvirus type 1 (FHV-1) TK gene. An open reading frame (ORF) of 987 nucleotides, capable of encoding a TK translation product of 328 amino acids, was identified. Alignment of the predicted amino acid sequence of the CHV TK with other herpesvirus TKs revealed homologies of 25-47%. The proposed nucleotide-binding site and thymidine-binding site sequences of known herpesvirus TKs could be aligned with similar sequences in CHV TK. Northern-blot analysis revealed 1.3 kb and 5.0 kb mRNAs as the TK-specific transcripts. It is probable that the 1.3 kb transcript codes for the CHV TK and that the 5.0 kb transcript codes for the CHV TK and the downstream sequence.

Thy-1 antigen mediates apoptosis of rat glomerular cells in vitro and in vivo

Injection of anti-Thy-1 antibody into a rat induces immediate glomerular cell death and subsequent development of glomerulonephritis. Whether the immediate cell death in this model is apoptotic has yet to be determined. Recent in vivo studies on thymocyte death have elucidated that the Thy-1 molecule can activate intracellular signaling for apoptosis. This observation prompted us to re-examine whether stimulation with anti-Thy-1 antibody can provoke apoptosis in the rat glomerulus. We found that anti-Thy-1 antibody could induce laddered DNA fragmentation of isolated glomeruli and mesangial cells in culture, definite biochemical evidence for random double-stranded breaks through apoptosis. Such DNA laddering was also demonstrated in the isolated glomeruli of rats that had been infused with anti-Thy-1 antibody several hours before. Furthermore, the terminal deoxynucleotidyl-transferase-mediated oligonucleotide nick end labeling technique stained a cell in the mesangium. Although apoptosis may be considered a candidate mechanism mediating resolution of hypercellularity in the anti-Thy-1 model, we propose that it is also involved in the immediate cell death in this model.

Accumulation of indoxyl-beta-D-glucuronide in uremic serum: suppression of its production by oral sorbent and efficient removal by hemodialysis

We identified and quantified indoxyl-beta-D-glucuronide in uremic serum and urine to determine the metabolism of indoles including indoxyl sulfate in uremic patients. Serum levels of indoxyl-beta-D-glucuronide were markedly increased in undialyzed uremic patients, in patients on hemodialysis, and in patients on continuous ambulatory peritoneal dialysis. Urinary excretion of indoxyl-beta-D-glucuronide was also increased in undialyzed uremic patients. Urinary indoxyl-beta-D-glucuronide was significantly correlated with serum indoxyl sulfate, indicating that a high serum level of indoxyl sulfate leads to the enhanced synthesis of indoxyl-beta-D-glucuronide. Oral sorbent (AST-120) administration markedly decreased the serum and urine levels of indoxyl-beta-D-glucuronide as well as indoxyl sulfate in the undialyzed uremic patients. Serum indoxyl-beta-D-glucuronide could be efficiently removed by hemodialysis despite its high protein-binding ratio of about 50%. In conclusion, the serum level of indoxyl-beta-D-glucuronide increases in uremic patients due to renal insufficiency and its increased production. The production of indoxyl-beta-D-glucuronide can be suppressed by oral sorbent treatment, and serum indoxyl-beta-D-glucuronide can be efficiently removed by hemodialysis.

Neuroendocrine mechanism mediating fasting-induced suppression of luteinizing hormone secretion in female rats

Forty-eight hours fasting profoundly suppresses LH secretion in female rats. The following neural pathway mediating fasting-induced suppression of LH secretion has been suggested by a series of experiment: a signal associated with fasting emanating from the upper digestive tract reaches the A2 region in the medulla oblongata via afferent vagal nerve so as to activate the noradrenergic pathway projecting to the hypothalamic paraventricular nucleus (PVN); this results in an increased corticotropin-releasing hormone release to suppress LHRH release and then LH release. The PVN and A2 region of the medulla oblongata are the estrogen feedback sites to activate the above-mentioned neural pathway. The estrogen feedback action on the PVN and A2 region is considered to be due to an increased expression of estrogen receptors in these nuclei after 48-h fasting. The response of gonadal axis during fasting could be due to the changes in some nutrients, such as glucose and free-fatty acids. In this context, malnutrition could be a kind of stress accompanied by an increased feeding behavior and decreased gonadal activity.

Overexpression of c-myc messenger RNA in primary and metastatic lesions of carcinoma of the stomach

BACKGROUND

Although c-myc expression in carcinoma of the stomach has been reported to be involved in progression of the disease, little is known about the mechanism or significance of its expression.

STUDY DESIGN

We measured c-myc messenger RNA (mRNA) levels by Northern blot hybridization in 51 primary gastric carcinoma lesions and 15 metastatic lesions accompanied by normal mucosal tissues from the same patients. The extent of c-myc mRNA expression in malignant lesions was determined and compared with that in normal mucosal tissues. The clinical and pathologic significance of c-myc mRNA expression was investigated.

RESULTS

In 35 (68.6 percent) of 51 primary gastric carcinomas c-myc mRNA was overexpressed. Expression was found to be more frequent and stronger in early lesions than in advanced lesions (90 percent, 6.15-fold compared with 54.8 percent, 2.42-fold, p < 0.05). However, c-myc mRNA expression in the primary lesions showed little influence on either the histologic features or the disease progression. C-myc mRNA levels were higher in every metastatic lesion than in the primary lesions (9.89-fold compared with 3.04-fold, p < 0.05).

CONCLUSIONS

These observations suggest that c-myc mRNA overexpression may play a role in the early development of primary lesions as well as in the formation of metastatic lesions of carcinomas of the stomach.

Nitrogen dioxide exposure increases airway contractile response to histamine by decreasing histamine N-methyltransferase activity in guinea pigs

To determine the mechanism responsible for nitrogen dioxide (NO2)-induced airway hyperresponsiveness, we examined the effects of NO2 exposure on the contractile response to histamine and the level of histamine N-methyltransferase (HMT) activity, a histamine-degrading enzyme, in guinea pig trachea in vitro. Guinea pigs were divided into seven groups. Each group received continuous NO2 exposure (2.0 ppm) for either 2, 6, 12, 24, 48, or 96 h. The remaining group did not receive NO2 exposure (control). HMT activity in trachea was decreased from the control value of 70.3 +/- 7.7 pmol/min/mg protein to 34.6 +/- 6.7 pmol/min/mg protein by 12 h exposures of NO2. However, 24 and 48 h exposures of NO2 did not significantly alter HMT activity. In contrast, HMT activity exceeded the control value by 96 h exposures of NO2 (85.5 +/- 5.1 pmol/min/mg protein). Twelve hour exposures of NO2 shifted the concentration-response curves to histamine to lower concentrations and significantly reduced the median effective concentration (EC50) of histamine (log M) from the control value of -5.16 +/- 0.09 to -6.15 +/- 0.14 (P < 0.01). In contrast, the EC50 concentration of histamine (log M) increased from the control value of -5.20 +/- 0.10 to -4.90 +/- 0.11 by 96 h exposures of NO2 (P < 0.05). However, NO2 exposure did not alter the contractile response to acetylcholine. Morphologically, tracheal epithelial cells had vacuoles after 12 h exposures of NO2, but denudation of the epithelium did not occur during this experiment. In situ hybridization for HMT mRNA demonstrated that the level of HMT mRNA increased dominantly in tracheal epithelial cells after 96 h exposures of NO2. The present results indicated that the decrease in the level of HMT activity in the trachea was closely associated with the increase in the airway contractile response to histamine, suggesting that NO2-induced transient airway hyperresponsiveness to histamine is due to the decreased capacity of histamine catabolism in airway.

Pathophysiology of advanced glycation end-products in renal failure

beta 2-Microglobulin is a major constituent of amyloid fibrils in dialysis-related amyloidosis, a serious complication leading to bone and joint destruction in long-term haemodialysis patients. However, the molecular pathogenesis of this complication remains unknown. Intact beta 2-microglobulin per se seems an unlikely contributor to the pathogenesis, because no difference in the plasma levels of intact beta 2-microglobulin has yet been found between haemodialysis patients with and without this complication. Some investigators have therefore focused on the modification of this molecule. Recent studies have revealed a new modification of beta 2-microglobulin in amyloid fibrils-the advanced glycation end-products (AGEs) formed by a non-enzymatic reaction between sugar aldose and protein. Further studies have suggested that the interaction of AGE-modified beta 2-microglobulin with monocyte/macrophage and osteoclast/osteoblast gives a plausible albeit partial explanation for the mechanism of bone and joint destruction in dialysis-related amyloidosis. This article discusses the pathophysiology of AGEs in renal failure and the modification of beta 2-microglobulin with AGEs, especially focusing on their structure and pathological role in dialysis-related amyloidosis.

Colorimetric microtiter plate based assay for detection and quantification of amplified Actinobacillus actinomycetemcomitans DNA

We developed a colorimetric microtiter plate-based assay for the detection and quantification of polymerase chain reaction-amplified DNA fragment specific for Actinobacillus actinomycetemcomitans. We amplified the 396-bp leukotoxin-specific DNA fragment by using two oligonucleotide primers, one carrying a biotin group at the 5' end and another one with a digoxigenin at the 5' end. Following amplification, the biotinylated polymerase chain reaction products were applied to a microtiter well precoated with avidin. The colorimetric detection and quantification were achieved by an enzyme-linked immunosorbent assay using alkaline phosphatase-conjugated anti-digoxigenin antibody. The detection limit of the colorimetric assay was found to be as little as 500 fg of purified A. actinomycetemcomitans DNA and as few as 50 A. actinomycetemcomitans. Therefore, this colorimetric assay was able to estimate the amount of A. actinomycetemcomitans in subgingival plaque samples. We concluded that the colorimetric assay of the PCR product is a very useful method not only to detect the presence of A. actinomycetemcomitans but also to quantify the amount of A. actinomycetemcomitans in large numbers of subgingival plaque samples.

Low cerebrospinal fluid concentrations of peptide histidine valine and somatostatin-28 in Alzheimer's disease: altered processing of prepro-vasoactive intestinal peptide and prepro-somatostatin

Recent studies have indicated that deposition of beta amyloid peptide in the brains of patients with senile dementia of the Alzheimer type (SDAT) is a consequence of abnormal processing of the beta amyloid protein precursor. In addition, reduced concentrations of various peptides have been measured in post-mortem brain tissue and cerebrospinal fluid (CSF) of patients with SDAT. We determined concentrations of the peptides derived from prepro-vasoactive intestinal peptide (VIP)--peptide histidine methionine-27 (PHM-27), peptide histidine valine (PHV) and VIP--and peptides derived from prepro-somatostatin (prepro-SS), SS-14 and SS-28, in CSF of patients with SDAT by radioimmunoassay combined with high performance liquid chromatography. We found significantly reduced levels of total PHM-immunoreactivity (IR) and PHV, and unaltered levels of PHM-27 and VIP in SDAT, compared with those in controls. Total SS-IR and SS-28 concentrations were significantly reduced in SDAT, while SS-14 levels did not differ from those of controls. These results suggest that an altered processing of the prepro-peptides of VIP and SS may occur in SDAT and that these alterations might have a significant role in the pathogenesis of SDAT.

N-acetyltransferase activity in the urine in Japanese subjects: comparison in healthy persons and bladder cancer patients

The activity of urinary N-acetylamino-transferase was determined by high-performance liquid chromatographic assay of acetylisoniazid and isoniazid after administration of isoniazid to healthy Japanese male and bladder cancer patients in Japan. The healthy subjects were 47 college students and 44 company employees ranging from 18 to 64 years old (mean +/- SC = 34.5 +/- 13.7). The bladder cancer group consisted of 58 male and 13 female patients, ranging from 28 to 82 years old (mean +/- SD = 60.8 +/- 11.6), who were being treated at several hospitals. The slow phenotype, defined as an acetylation ratio (acetylisoniazid/isoniazid) of less than 2.0, was observed in 13 (14.3%) of the 91 healthy subjects, and in 20 (28.2%) of the 71 bladder cancer patients; the difference between the two groups is significant (p < 0.05). A histogram of the acetylation ratio values showed an overall leftward shift of the patient group, indicating low values of acetylation ratio in this group as a whole (p < 0.01).

Severity of alexithymia is related to psychosocial factors in patients with peritoneal dialysis

We examined the relationship between alexithymia and psychosocial factors in 72 peritoneal dialysis patients. The 72 patients had significantly higher scores on alexithymia and anxiety than did 73 healthy volunteers. The alexithymia scores were significantly and positively correlated with anxiety scores, suggesting that alexithymia may be related to anxiety derived from the stress associated with dialysis therapy. After 3 yr. of follow-up consultations, patients were still showing higher scores on alexithymia and anxiety; however, alexithymia scores were not correlated with anxiety scores but rather were significantly associated with poor social support. Alexithymic characteristics may be related to psychosocial factors such as the availability of social support.

The feline herpesvirus type 1 ICP4 down-regulates feline immunodeficiency virus long terminal repeat (LTR)-directed gene expression via the C/EBP site in the LTR

We investigated effects of feline herpesvirus type 1 (FHV-1) ICP4 on feline immunodeficiency virus (FIV) long terminal repeat (LTR)-directed gene expression by transient transfection assay in Crandell feline kidney cells. We demonstrated that FHV-1 ICP4 significantly stimulates the FIV LTR after introduction of site-specific mutation of the C/EBP site in the LTR, and the C/EBP site is sufficient to confer inhibitory effects by FHV-1 ICP4 on a heterologous promoter. These results indicate that FHV-1 ICP4 possesses both ability to transactivate FIV LTR-directed gene expression and to down-regulate the FIV LTR via the C/EBP site.