Ultrastructural, immunocytochemical and stereological investigation of hepatocytes in a patient with the mutation of the ornithine transcarbamylase gene

We studied a male newborn suffering from deficiency of ornithine transcarbamylase (OTC) that is due to a G-to-A substitution in codon 269 of the OTC gene. This study intends to define the cell biological mechanisms in this naturally occurring OTC mutation which may explain the mild clinical course in spite of the very low residual enzyme activity. Using immunogold labeling of thawed thin frozen sections of liver from this patient and a control liver, we analyzed the quantitative distribution of several mitochondrial proteins in the cytosol and the mitochondria of hepatocytes. In addition, the absolute volumes and surface densities of mitochondria and peroxisomes were determined. Our results show that the absolute volume of mitochondria in the patient's hepatocytes was increased to 141% (P < 0.001) without any change in the surface density indicating an increased number of mitochondria. In the patient's hepatocytes the peroxisomes were increased in size but not in number. The concentration of OTC was elevated in the cytosol (P < 0.001) and to a lesser extent in mitochondria (P < 0.01) of the patient's hepatocytes thus indicating a doubling of OTC relative to control liver cells. The quantity of OTC in mitochondria was 63% higher in diseased liver cells. By conventional thin section electron microscopy, mitochondria-like structures with poorly defined cristae and an electron-dense matrix were observed in the cytoplasm of the diseased hepatocytes. By immunoelectron microscopy, they contained the cytochrome c oxidase II subunit as well as DNA but lacked OTC, carbamylphosphate synthetase, F1-ATPase beta subunit and catalase. Thus it appears that these structures represent defective and probably degenerating mitochondria. Our data indicate that the reduced enzyme activity of the mutant OTC is partly compensated by an increased amount of enzyme molecules in the cytosol as well as mitochondria combined with an increase in the biogenesis of mitochondria.

Meninges play a neurotrophic role in the regeneration of vasopressin nerves after hypophysectomy

Following hypophysectomy the regenerating fibers of magnocellular neurons are known to establish new neurohemal connections with reorganized vasculatures in the median eminence, which lead to establishment of a posterior pituitary-like structure. In order to examine the role of the meninges (the pia mater and the arachnoid) in this regeneration process, we implanted the meningeal tissues obtained from neonatal rat pups into the third ventricle of the adult rats, and then hypophysectomized the host animals. Ten days after hypophysectomy, the meningeal tissue grafts were found to be densely innervated by regenerating vasopressin-immunoreactive fibers. Such fibers had dots and frequently formed large punctuations. On the contrary, few vasopressin fibers were found within the cortical tissue grafts. Further, the exposure of primary hypothalamic cell cultures to the medium conditioned by meningeal cell cultures promoted not only the survival of vasopressin-immunoreactive neurons but also the outgrowth and aborization of the neurites. The survivals of cortical and cerebellum neurons in culture were also promoted by the conditioned medium. These findings raise the possibility that the meninges play an important role in the axonal regeneration process after hypophysectomy.

Overexpression of matrix metalloproteinase-7 mRNA in human colon carcinomas

BACKGROUND

Matrix metalloproteinase-7 (MMP-7) is a member of the family of matrix-degrading metalloproteinases (MMPs) that are considered to contribute to cancer invasion and metastasis. One of the gene products that the authors have isolated by a cDNA subtraction of human gastric cancer minus normal gastric mucosa is MMP-7. The purpose of this study was to examine the expression of MMP-7 mRNA in different stages of human colorectal carcinomas.

METHODS

A subtracted complementary DNA library was generated from a paired sample of human gastric carcinoma minus normal gastric mucosa. Screening of the library clones determined that MMP-7 mRNA was overexpressed. The complementary DNA insert was then used as a probe to evaluate the expression in a larger number of surgical samples of human colorectal carcinomas by Northern hybridization.

RESULTS

The mRNA signal was greater in the colorectal carcinoma than in paired adjacent normal colonic or rectal mucosa in 39 of 47 cases. The expression of MMP-7 mRNA in tumor tissues increased with increasing Dukes' stage (P < 0.05). The MMP-7 mRNA expression was greatest in the metastatic liver lesions.

CONCLUSIONS

The findings imply that MMP-7 mRNA is overexpressed in human colorectal carcinomas and that MMP-7 may prove useful as a marker of biologic aggressiveness.

Overexpression of matrix metalloproteinase-7 mRNA in human colon carcinomas

BACKGROUND

Matrix metalloproteinase-7 (MMP-7) is a member of the family of matrix-degrading metalloproteinases (MMPs) that are considered to contribute to cancer invasion and metastasis. One of the gene products that the authors have isolated by a cDNA subtraction of human gastric cancer minus normal gastric mucosa is MMP-7. The purpose of this study was to examine the expression of MMP-7 mRNA in different stages of human colorectal carcinomas.

METHODS

A subtracted complementary DNA library was generated from a paired sample of human gastric carcinoma minus normal gastric mucosa. Screening of the library clones determined that MMP-7 mRNA was overexpressed. The complementary DNA insert was then used as a probe to evaluate the expression in a larger number of surgical samples of human colorectal carcinomas by Northern hybridization.

RESULTS

The mRNA signal was greater in the colorectal carcinoma than in paired adjacent normal colonic or rectal mucosa in 39 of 47 cases. The expression of MMP-7 mRNA in tumor tissues increased with increasing Dukes' stage (P < 0.05). The MMP-7 mRNA expression was greatest in the metastatic liver lesions.

CONCLUSIONS

The findings imply that MMP-7 mRNA is overexpressed in human colorectal carcinomas and that MMP-7 may prove useful as a marker of biologic aggressiveness.

[The comparison of hypnotic potency of nitrous oxide with that of sevoflurane: evaluation by the middle latency auditory evoked response]

In 10 consented patients (ASA I-II) we quantitated the hypnotic potencies of 0.7 MAC nitrous oxide and 0.7 MAC sevoflurane by measuring auditory evoked response (AER), and compared the hypnotic potency of nitrous oxide with that of sevoflurane at the same MAC. In each patient, measurements of AER waves were performed in the following three stages, 0.7 MAC nitrous oxide, 0.7 MAC sevoflurane and 0.7 MAC nitrous oxide after induction of anesthesia. Analysis of variance was used to compare the hypnotic potencies between two inhaled anesthetics. Pa and Nb latencies with sevoflurane were longer than those with nitrous oxide, and Pa and Nb amplitudes with sevoflurane were greater than those with nitrous oxide. However, we found that there were no statistical significances in our results. In conclusion, nitrous oxide exerts as much hypnotic effect as sevoflurane.

Reappearance and long-term maintenance of connexin32 in proliferated adult rat hepatocytes: use of serum-free L-15 medium supplemented with EGF and DMSO

Intercellular communication, especially gap junctional communication, is thought to be one of the highly differentiated functions of hepatocytes. In primary cultures of rat hepatocytes, it has been considered that the maintenance and the reinduction of differentiated functions is very difficult. In the present study, we succeeded in inducing the gap junctional protein connexin32 (Cx32) in adult rat hepatocytes cultured in serum-free L-15 medium supplemented with epidermal growth factor (EGF) and dimethylsulfoxide (DMSO). When the hepatocytes were cultured in L-15 medium supplemented with 20 mM NaHCO3 and 10 ng/ml EGF in a 5% CO2:95% air incubator, the cells proliferated. Fluorescence immunocytochemistry showed spots immunoreactive to Cx32 on the cell membranes between adjacent cells until day 3, but only a few Cx32-positive spots were found after day 4. Western and northern blot analyses also showed that the amounts of both the protein and mRNA of Cx32 in the cells decreased with time in culture. However, when the cells were treated with 2% DMSO from day 4, the immunoreactive spots reappeared on the cell membranes from day 6 and both their number and intensity gradually increased. The reappearance of Cx32 was accompanied by increases in both the protein and mRNA of Cx32. Furthermore, the expression of Cx32 was well maintained, together with extensive gap junctional intercellular communication, for more than 4 weeks. In addition, ultrastructurally, many gap junctional structures were observed between the hepatocytes, and the antibodies to Cx32 were shown to bind to those structures. This culture system may be useful for studies of the reconstruction of the gap junctional structure, the intracellular pathways of the proteins, and the regulation of synthesis and processing in differentiated hepatocytes.

Long-term effect of eicosapentaenoic acid ethyl (EPA-E) on albuminuria of non-insulin dependent diabetic patients

Dietary cod-liver oil containing eicosapentaenoic acid is effective on microvascular albumin leakage in diabetic patients with albuminuria. We determined the long-term effects of oral pure eicosapentaenoic acid ethyl (EPA-E: 900 mg/day) administration on diabetic nephropathy in non-insulin dependent diabetic (NIDDM) patients. The effects of EPA-E were determined by observing the changes of the index of urine albumin excretion level/urine creatinine (Cr) excretion level (UAI), the ratio of beta 2-microglobulin excretion level/urine Cr excretion level (beta 2-MG/Cr) and the ratio of N-acetyl-D-glucosaminidase excretion level/urine Cr excretion level (NAG/Cr) at 3, 6 and 12 months after the start of the treatment. Oral EPA-E administration immediately improved the increased UAI at 3 months after the start of treatment. A significant improvement of the UAI by EPA-E was sustained 12 months later. EPA E administration also tended to decrease the urine beta 2-MG/Cr ratio from 6 months, but the difference was statistically not significant. However, the urine NAG/Cr ratio was not changed by EPA-E administration. EPA-E administration did not affect blood pressure levels, glycemic control and lipid metabolism in these patients. The present data indicated that EPA-E administration improved increased albumin excretion in NIDDM patients with nephropathy and its effects on albuminuria sustained for at least 12 months after the start of treatment. However, tubular factors were not influenced by EPA-E administration.

Immunohistochemical expression of sialyl Tn and sialyl Lewis(a) antigens in stromal tissue correlates with peritoneal dissemination in stage IV human gastric cancer

Immunohistochemical expression of sialyl Tn antigen (TKH2 and B72.3), sialyl Lewis(a) antigen (CA19-9) and CEA was examined in 52 cases with Stage IV gastric cancer, the objective being to examine whether or not these tumour-associated antigens show different expression between peritoneal dissemination and liver metastasis. Stromal type for TKH2, B72.3, CA19-9 and CEA were seen in 14 (50%), 13 (46%), 18 (64%) and nine (32%) cases with peritoneal dissemination, respectively, and in four (17%), three (13%), four (17%) and four (17%) cases with liver metastasis, respectively. The stromal type correlated to peritoneal dissemination in TKH2 (P < 0.05) B72.3 (P < 0.05) and CA19-9 (P < 0.05). In other clinicopathological factors, the stromal type for TKH2, B72.3 and CA19-9 correlated to the undifferentiated type. However, even in the undifferentiated type group, the stromal type correlated to peritoneal dissemination in TKH2 (P < 0.05), B72.3 (P < 0.05) and CA19-9 (P < 0.05). Based on these results, the spread of sialyl-rich tumour-associated antigens into the surrounding stroma in the undifferentiated type of gastric cancer may be associated with peritoneal dissemination.

The inductive effect of bone morphogenetic protein (BMP) on human periodontal fibroblast-like cells in vitro

Bone morphogenetic protein (BMP) has the capability of 1) inducing bone formation in non-bone tissue such as muscle, 2) promoting proliferation and differentiation of human dental pulpal cells, and 3) inducing early formation of both osteodentin and regular tubular dentin. In addition, when BMP is implanted in periodontal defects, it stimulates regeneration of periodontal tissues. In the present study, we sought to explore the mechanisms by which BMP induces these effects, using immunohistochemical methods to investigate periodontal fibroblast-like cells in vitro. Cellular production of fibronectin, endogenous BMP and alkaline phosphatase were measured using image analysis of immunohistochemical reactivity. Periodontal fibroblast-like cells incubated with exogenous BMP showed decreased alkaline phosphatase activity, unchanged fibronectin production, but increased expression of endogenous BMP compared with control specimens incubated without BMP. These data suggest that regenerative as well as inductive effects of BMP on undifferentiated periodontal mesenchymal cells may be mediated through its ability to modulate cellular expression of these substances.

A simple classification of lymph node level in gastric carcinoma

BACKGROUND

Because insufficient lymph node examination can cause erroneous listing of earlier-nodal-stage gastric carcinoma (stage migration phenomenon), surgical results must be evaluated based on a highly accurate examination of the dissected lymph nodes. To establish a simple and useful classification of lymph node level, we analyzed the frequency and distribution of lymph node metastasis by using curatively treated node-positive gastric carcinoma.

PATIENTS AND METHODS

Various clinicopathologic data were analyzed with reference to the degree of lymph node metastasis by using 240 patients with curatively resected node-positive gastric carcinoma. The cases were divided into the following three groups: 142 with positive level I (perigastric) nodes, 71 with positive level II (intermediate) nodes, and 27 with positive level III (distant) nodes, irrespective of the location of tumors.

RESULTS

The level of lymph node metastasis clearly correlated with the survival of patients, with the 5-year survival rates for level I, II, and III cases being 67%, 35%, and 26%, respectively (P < 0.01). The degree of lymph node metastasis was determined by the number of positive nodes (P < 0.01), the depth of invasion (P < 0.01), the size of tumors (P < 0.01), and the location of tumors (P < 0.05).

CONCLUSION

This simple classification of lymph node level (level I, II, and III) is useful for the evaluation and prediction of surgical results in gastric carcinoma.

The bceT gene of Bacillus cereus encodes an enterotoxic protein

A toxin gene (bceT) on a 2.9 kb DNA fragment of Bacillus cereus B-4ac was cloned and expressed in Escherichia coli, and its nucleotide sequence determined. The DNA fragment contained an open reading frame capable of encoding a polypeptide of 336 amino acids with a molecular mass of 41039 Da. The translated product in E. coli exhibited Vero cell cytotoxicity, and was positive in a vascular permeability assay. It also caused fluid accumulation in a ligated mouse ileal loop and was lethal to mice upon injection. These biological activities are considered characteristic of diarrhoeal enterotoxins. We therefore conclude that this gene, designated bceT, encodes one of the enterotoxic proteins of B. cereus which cause food-borne diarrhoea.

Estrogen-depleted condition induces apoptosis of rat mammary cancer cells after entering the S-phase of the cell cycle

To elucidate the relationship of estrogen-depleted condition to apoptosis and tumor regression, 7,12-dimethylbenz[a]anthracene-induced mammary cancers of Sprague-Dawley rats were ovariectomized or treated with the anti-estrogenic agent epitiostanol after which proliferative activity and the incidence of apoptosis were investigated using the nick end labeling method, agarose gel electrophoresis of DNA, electron microscopy, the BrdU-labeling method and mitotic count. Tumor regression was found after 7-day treatment, and apoptosis induced by the agent on the 3rd day was clearly shown in both agarose gel electrophoresis of DNA and electron microscopy, which are two major methods used to judge apoptosis. The incidence of apoptosis revealed by the nick end labeling method reached its maximum, about threefold the control level, on the 3rd day of epitiostanol treatment compared with control tumors (P < 0.01). The incidence of the cells incorporating BrdU reached its maximum of 9.7% on the 2nd day of the treatment, while the incidence in tumors without treatment was 7.5% (P < 0.05). Subsequently, the incidence of apoptosis was reduced after 7-day treatment, and the incidence of BrdU-positive cells was significantly reduced to about 3% after 5-day treatment. The incidence of mitosis did not change until the 3rd day of the treatment and was reduced after 5-day treatment. Similarly, chronological changes of the incidences of BrdU-labeled cells, apoptotic cells and mitosis were observed in the tumors after ovariectomy. BrdU-labeled apoptotic bodies were detected in the tumors on the 3rd day in epitiostanol-treated rats that received a 6-hr bolus of BrdU before sacrifice.(ABSTRACT TRUNCATED AT 250 WORDS)

Antihypercholesterolemic effect of undigested fraction of soybean protein in young female volunteers

The significant antihypercholesterolemic effect of the undigested high molecular fraction (HMF) of soybean protein is known in rats, but such an effect has not been shown in humans. The present two experiments were designed to elucidate it in humans. Subjects were female university students who had relatively high serum cholesterol levels for their age. In Experiment 1, subjects took 8% of their total energy from casein, soybean protein isolate (SPI), or HMF daily for 14 days. Five basic menus and snacks were cycled. Energy intakes and daily activities were kept constant and body weight was maintained. The HMF group showed decreased low-density lipoprotein cholesterol (LDL-C) as compared to other groups. In Experiment 2, subjects took 4% of total energy from casein or HMF daily for a menstruation period. Five basic menus and snacks which contained two egg yolks (about 500 mg cholesterol) were cycled. Energy intakes and daily activities were kept constant and body weight was maintained. A decrease in LDL-C and an increase in high-density lipoprotein cholesterol (HDL-C) were observed in the HMF group as compared to the casein group. Fecal acidic steroid excretion was greater in the HMF group than in the casein group (p < 0.05). The results confirmed that HMF increases fecal steroid excretion and reduces serum cholesterol levels in humans.

[Epidemiological studies on enteric adenovirus gastroenteritis in children]

Enteric adenoviruses (EAd), adenovirus (Ad) types 40 and 41, have been established as causative agents of gastroenteritis. By electron microscopic (EM) survey of acute gastroenteritis in children in the Matsuyama area, Ad were detected in 275 of 6476 fecal samples obtained from 1980 to 1993. Two-hundred-thirteen Ad-positive samples were tested for serotyping by the enzyme-linked immunosorbent assay (ELISA) using three monoclonal antibodies, Ad group-specific, Ad 40 type-specific and Ad41 type-specific antibody. Of 199 samples serotyped by ELISA, 65 were identified as Ad40, 73 as Ad41, 1 as double infection with Ad40 and Ad41, and 60 as Non-EAd. About 70% of Adenovirus detected by EM were suggested to be EAd. Other epidemiological feature was as follows: EAd were detected throughout the year. The predominant serotype was Ad40 during 1980-1985, while Ad41 were observed after 1986. EAd were detected most frequently from the children aged 0-3 years. The incidence of fever in EAd positive group was lower (30%) than that (67%) in the Non-EAd positive group. The incidence of vomiting, nausea and respiratory symptoms was higher in Ad41 associated infections than Ad40.

The heterogeneity of microsatellite instability in multiple gastric cancers

To obtain a better understanding of the role of genetic instability in developing gastric cancer, it is of great interest to examine microsatellite alterations in synchronous multiple gastric cancers that are thought may have the same genetic background and the same microenvironment of the stomach. We report our experience with two patients with synchronous multiple gastric cancers; patient 1 showed two carcinomas in the stomach, whereas patient 2 showed two carcinomas and two adenomas in the stomach. We examined the DNAs from the two cases for microsatellite instability and expected that the status of microsatellite instability in each tumor from the same stomach would be the same. However, patient 2 revealed heterogeneity in the microsatellite instability, i.e., an early cancer that showed some apparent alterations, whereas the other advanced cancer and two adenomas did not. On the other hand, neither of the two carcinomas in patient 1 showed microsatellite instability. To our knowledge, there has been no previous report of microsatellite instability in multiple gastric cancers. In this report, we describe a case that revealed such a heterogeneity of the microsatellite instability, in which the carcinogenic process of each tumor may undergo different genetic alterations even under the same genetic conditions and background.

The overexpression of elongation factor 1 gamma mRNA in gastric carcinoma

BACKGROUND

Elongation factor 1 gamma (EF1 gamma) has been isolated from a pancreatic cancer cell line, while the overexpression of EF1 gamma has also been observed in colorectal carcinomas and adenomas. There is, however, still little information on the expression of EF1 gamma in gastric carcinoma.

METHODS

The authors examined the expression of EF1 gamma mRNA in 30 gastric carcinomas and their corresponding paired adjacent normal mucosae obtained during surgery while also examining 10 human digestive tract carcinoma cell lines using Northern blot hybridization.

RESULTS

An overexpression was observed in 22 (73%) of 30 gastric carcinomas, relative to the corresponding normal tissue. In a clinicopathologic study, no relationship was observed between the overexpression of EF1 gamma mRNA and the histologic grading or depth of tumor invasion. However, 15 (68%) of 22 overexpressed cases were positive for vascular permeation, whereas only 1 of 8 nonoverexpressed cases was positive for vascular permeation, and the difference was significant (P < 0.05). Nine (90%) of 10 with more than a 10-fold overexpression relative to the corresponding normal tissue showed severe vascular permeation in the histologic specimens. Conversely, the expression of EF1 gamma was observed not only in the pancreatic and gastric carcinoma cell lines, but also in the hepatic, ileocecal, duodenal, and colon carcinoma cell lines.

CONCLUSIONS

The overexpression of EF1 gamma mRNA was observed in both the gastric carcinoma tissue and in all the other cell lines examined. This probable correlation with vascular permeation in gastric carcinoma is thus considered to provide another piece of useful pathologic information.

Carcinogenesis and histogenesis of esophageal carcinoma

Dysplasia is one of the most important subjects regarding carcinogenesis of the esophagus, because there is continuing controversy as to whether esophageal dysplasia is a cancerous lesion or a noncancerous lesion. In this study, it is histopathologically shown that dysplasia has a close correlation with cancer itself and that there is no substantial difference in the cell proliferative activity of dysplasia and intraepithelial carcinoma. These findings thus show that dysplasia has as high a potential for malignancy, thus it should be treated as an extremely early cancerous lesion of the esophagus to substantially improve the long term results of this disease. Conversely, esophageal carcinoma with glandular and/or mucus-secreting components is commonly found in addition to the ordinary component of squamous cell carcinoma, which indicates that this type of esophageal tumor originates not only from the squamous epithelium but also from the esophageal mucus gland or the ductal epithelium. These findings support the concept of field carcinogenesis in esophageal carcinoma.

Overexpression of matrix metalloproteinase-7 mRNA in human colon carcinomas

BACKGROUND

Matrix metalloproteinase-7 (MMP-7) is a member of the family of matrix-degrading metalloproteinases (MMPs) that are considered to contribute to cancer invasion and metastasis. One of the gene products that the authors have isolated by a cDNA subtraction of human gastric cancer minus normal gastric mucosa is MMP-7. The purpose of this study was to examine the expression of MMP-7 mRNA in different stages of human colorectal carcinomas.

METHODS

A subtracted complementary DNA library was generated from a paired sample of human gastric carcinoma minus normal gastric mucosa. Screening of the library clones determined that MMP-7 mRNA was overexpressed. The complementary DNA insert was then used as a probe to evaluate the expression in a larger number of surgical samples of human colorectal carcinomas by Northern hybridization.

RESULTS

The mRNA signal was greater in the colorectal carcinoma than in paired adjacent normal colonic or rectal mucosa in 39 of 47 cases. The expression of MMP-7 mRNA in tumor tissues increased with increasing Dukes' stage (P < 0.05). The MMP-7 mRNA expression was greatest in the metastatic liver lesions.

CONCLUSIONS

The findings imply that MMP-7 mRNA is overexpressed in human colorectal carcinomas and that MMP-7 may prove useful as a marker of biologic aggressiveness.

Microsatellite instability in Japanese gastric cancer

BACKGROUND

Recent studies have shown that microsatellites are unstable in various types of cancers, and such genetic instability at the microsatellite loci (microsatellite instability) has been considered to play an important role in the development of cancer. However, the clinicopathologic significance of microsatellite instability in gastric cancer has not been clarified.

METHODS

To elucidate the role of genetic instability in the development of gastric cancer, the presence of microsatellite instability was examined in 25 cases of gastric cancer using fresh-frozen tumor-normal paired samples using a polymerase chain reaction (PCR)-based method. Microsatellite instability was defined as tumors that showed altered banding patterns at two or more microsatellite loci.

RESULTS

The incidence of microsatellite instability in gastric cancer cases was 4 of 25 patients (16%) and 4 of 26 cancers (15%). A significantly high incidence of microsatellite instability was observed in both the elderly (P < 0.01) and in lymph node metastasis-negative patients (P < 0.05). All patients with gastric cancer showing microsatellite instability were negative for lymphatic or venous permeation. A statistically significant association of microsatellite instability with no lymphatic permeation was thus observed (P < 0.05).

CONCLUSIONS

This study revealed infrequent lymph node metastasis and lymph vessel invasion in the patients with gastric cancer demonstrating microsatellite instability. Although the number of examined cases was small, these findings suggest that gastric cancer that shows microsatellite instability may thus behave in a less malignant manner.

[Plasma concentration of cytosine arabinoside (Ara-C) in the elderly patients with hematological malignancy treated by Ara-C or cytarabine ocfosfate (SPAC)]

Plasma concentration of cytosine arabinoside (Ara-C) was determined in elderly patients with myelodysplastic syndromes or acute myelocytic leukemia who were treated with subcutaneous injection of Ara-C (Ara-C s.c.; 10 mg/m2/12 hr, 14-21 days), continuous drip infusion of Ara-C (Ara-C d.i.v.; 20 mg/m2/day, 24 hr 14 days) and/or oral administration of cytarabine ocfosfate (SPAC) (SPAC p.o.; 100 mg-300 mg/body/day, 14 days) by radioimmunoassay. In the Ara-C s.c. patients, the peak plasma level (Cmax) of Ara-C was 103 ng/ml and the time to reach Cmax was 15 min. The elimination half-like (t1/2) was 25 min and no accumulation was detected after 14 days of consecutive Ara-C s.c. administrations. In the SPAC p.o. patients, Cmax of Ara-C was 3-8 ng/ml and it took 3-5 days to reach Cmax. The plasma concentration level of Ara-C remains almost at the Cmax level during the SPAC p.o. administration and it remained higher than 0.32 ng/ml for as long as 15 days after the end of administration. In a Ara-C d.i.v. patient, plasma level of Ara-C was detected 4-7 ng/ml during the administration (day 7 through day 14). In all patients bone marrow suppression was observed after chemotherapy regardless of regimen, and there was no significant difference between nadir peripheral cell blood counts of Ara-C s.c. patients and SPAC p.o. patients.

Immunohistochemical evaluation of tenascin in benign eccrine gland tumors: comparison with laminin and fibronectin

Surgically resected specimens of skin appendage tumors, spiradenoma, poroma of eccrine glands, syringoadenoma, syringoadenoma papilliferum and mixec tumor of skin were evaluated for tenascin, as well as the basement membrane-associated protein laminin, and the extracellular matrix protein fibronectin, using immunohistochemical methods. In normal sweat glands, tenascin was localized as a delicate, thin band in the immediate vicinity of the basement membrane and laminin was limited to the basement membrane. Tenascin in syringoadenoma was also expressed linearly adjacent to the basement membrane. Mixed tumors of skin showed a characteristic distribution of tenascin in the modified myoepithelial cell area adjacent to the tumor epithelia with a heterogeneous pattern, and particularly strong expression in the hyalinous and chondroid areas. In addition, the localization of laminin in the basement membranes of tumors, intracellular immunoreactivity was observed in syringoadenoma, syringocystadenoma papilliferum, and mixed tumor of skin. Fibronectin reactivity was visualized as a diffuse staining in the tumor stroma of eccrine poroma but its expression was restricted in eccrine spiradenoma. The present study suggests a heterogeneity in the distribution of basement membrane and extracellular matrix proteins in skin appendage tumors and elucidation of their functional roles would assist in understanding the changes in the supporting tumor stroma following neoplastic changes.

Ca(2+)-free, high-Ca2+ coronary perfusion suppresses contractility and excitation-contraction coupling energy

We studied the mechanoenergetic effects of a short-term Ca(2+)-free, high-Ca2+ Tyrode solution coronary perfusion in eight excised, cross-circulated canine hearts. The perfusion protocol consisted of coronary perfusion with Ca(2+)-free Tyrode solution for 10 min followed by high-Ca2+ (16 mM) Tyrode solution for 5 min. This new protocol successfully induced acute contractile failure in seven hearts, without myocardial ultrastructural changes. We studied the end-systolic pressure-volume relation (slope = Emax, a contractility index) and the relation between oxygen consumption per beat (VO2) and systolic pressure-volume area (PVA) in these failing hearts. These hearts had no increase in end-diastolic pressure at a given volume, a 40% decrease in Emax and a proportional decrease in the PVA-independent VO2 for 1-4 h, but no decrease in the oxygen cost of PVA, defined as the slope of the VO2-PVA relation. The oxygen cost of Emax for Ca2+ handling, defined as the slope of the relation between PVA-independent VO2 and Emax, was unchanged in the failing hearts. We conclude that the present protocol induced left ventricular contractile failure, primarily involving the suppression of Ca2+ handling energy for excitation-contraction coupling.

The high hepatocarcinogen susceptibility of LEC rats is genetically independent of abnormal copper accumulation in the liver

We previously reported that LEC rats, which show a spontaneous occurrence of liver injury and hepatocellular carcinoma (HCC), are highly susceptible to chemical carcinogens such as diethylnitrosamine (DEN). Since abnormal copper accumulation in the liver of LEC rats was found to be a cause of liver injury, it is necessary to elucidate whether the carcinogen susceptibility of LEC rats is related to the accumulation of copper in the liver. In this study we have examined the relationship between the susceptibility of FI [LEC x LEA or LEC x Fischer 344 (F344)] and FI backcross rats to DEN and hepatic copper concentration, as copper accumulation has been demonstrated to be inherited as an autosomal recessive trait. The groups of F1 and F1 backcross rats were given a single intraperitoneal injection of DEN (20 mg/kg wt) and subjected to a modified Solt-Farber protocol for assaying glutathione S-transferase placental form (GST-P)-positive foci. The hepatic copper concentration was examined by atomic absorption. Although no F1 rats showed a high copper concentration in the liver, the numbers of foci were as high as those in LEC rats which accumulate copper. Backcross rats separated into high and low copper concentration groups at an almost 1:1 ratio, but there was no significant difference in the mean numbers of foci between these two groups. The results clearly indicate that the high susceptibility of LEC rats to DEN is genetically independent of copper accumulation in the liver. A possible dominant inheritance of this high carcinogen susceptibility was suggested. Biochemical measurement of cytochromes P450 and b5 in the liver of F1 rats indicated that alterations in drug metabolizing enzymes may be partially responsible for the high carcinogen susceptibility of LEC rats.