Construction of cDNA bank from biopsy specimens for multiple gene analysis of cancer

We constructed a "cDNA bank" of human colorectal cancer and surrounding normal tissues with our unique mRNA assay system. Total nucleic acids extracted from patients' tissues were applied to 96-well plates, where poly(dT) sequences of oligonucleotides were immobilized. After hybridization, the cDNA was reverse-transcribed on the plate with the captured mRNA as a template, followed by synthesis of double-stranded (ds) cDNA. The resulting sense cDNA was removed from the plate, then used in PCR for analysis of various genes. The sense strand of the cDNA was repeatedly synthesized by using the immobilized antisense cDNA as a template even from plates used once and stored at 4 degrees C for as long as 6 months. Furthermore, the results of PCR could be easily compared among different specimens if the same amount of total mRNA were applied to the plate for the ds cDNA synthesis. This demonstrated that the cDNA bank constructed from clinical materials provides almost unlimited supplies of cDNA for multiple gene analysis of cancer.

Biologically active acylglycerides from the berries of saw-palmetto (Serenoa repens)

Brine shrimp lethality-directed fractionation of the 95% EtOH extract of the powdered, dried berries of Serenoa repens (Bart.) Small (saw-palmetto) (Palmae) led to the isolation of two monoacylglycerides, 1-monolaurin (1) and 1-monomyristin (2). Compounds 1 and 2 showed moderate biological activities in the brine shrimp lethality test and against renal (A-498) and pancreatic (PACA-2) human tumor cells; borderline cytotoxicity was exhibited against human prostatic (PC-3) cells. The fruits and extracts of saw-palmetto are taken orally as an herbal medicine to prevent prostatic hyperplasias.

[The relation between pyrimidine nucleoside phosphorylase (PyNPase) activity in colorectal cancer tissues and pathological effects]

Pyrimidine nucleoside phosphorylase (PyNPase) and IL-1 alpha concentration were measured in colorectal cancer tissues from 15 patients who preoperatively administered 5'-DFUR orally. The relation between changes of the PyNPase activity and pathological effects of resected specimens was studied. PyNPase activity changes showed that the increase cases were 9 patients and the decrease cases were 6 patients in pre- and post-administration of 5'-DFUR. The IL-1 alpha concentration in cancer tissues was 2933.65 +/- 2038.65 in the decrease cases and 1207.51 +/- 1378.83 in the increase cases. The level was significantly higher in the decrease case (p < 0.05). And there tended to be more pathologically effective in the decrease cases than in increase cases. The effects of preoperative oral chemotherapy in colorectal cancer was strongly influenced by changes of PyNPase activity and IL-1 alpha concentration in tumor tissues.

The effect of the disaster caused by the great Hanshin earthquake on people with intellectual disability

The vulnerability of people with intellectual disability when services are disrupted by a major earthquake is described. The value of an accessible register and multiple networks of support at the time of a major disaster is emphasized.

Severity of coronary artery calcification detected by electron beam computed tomography is related to the risk of restenosis after percutaneous transluminal coronary angioplasty

To assess the relationship between coronary artery calcification and the late success rate of percutaneous transluminal coronary angioplasty (PTCA), we performed electron beam computed tomography (EBCT) in 22 patients with ischemic heart disease who underwent PTCA. The calcification score in each coronary artery vessel was estimated and compared with the occurrence of restenosis at 3 months after PTCA. Angioplasty had been performed in 28 sites in 22 patients, and 12 sites exhibited restenosis. The mean calcium score in the unsuccessful PTCA vessels was significantly higher than in successful sites (228 vs 92). The overall late success rate of PTCA with moderate to severe calcification was extremely low at 29%. Coronary segments with diffuse and extensive calcification were not optimal target lesions for PTCA. Prediction of the late success rate after PTCA may be possible by prior evaluation of coronary artery calcification utilizing EBCT.

The role of lymph node dissection in the treatment of gallbladder carcinoma

BACKGROUND

Lymph node involvement is an important prognostic factor in gallbladder carcinoma (GBC). The lymph node involvement pattern, extent, and indications for systematic lymph node dissection for patients with advanced GBC were investigated.

METHODS

Forty-one patients with GBC who underwent radical resection with systematic regional lymph node dissection over the past 11 years were analyzed.

RESULTS

The lymph node metastasis rate was 63.4% overall, 0% in pT1 disease, 61.9% in pT2 disease, and 81.3% in pT3/pT4 disease. When reviewed according to site, the rate was 41.5% in pericholedochal lymph nodes, 22.0% in the lymph nodes around the common hepatic artery and the portal vein, 36.6% in the posterior pancreaticoduodenal lymph nodes, 28% (5/18) in the celiac lymph nodes, 19% (3/ 16) in the superior mesenteric artery (SMA) lymph nodes, and 26% (7/27) in the aortocaval paraaortic lymph nodes. Patients with severe hepatoduodenal ligament invasion had high rates of paraaortic lymph node involvement. The mortality rate was 2.4% (1 of 41 patients) and the 5-year survival rate was 33.1% overall, 100% in patients with pT1 disease, 49.8% in patients with pT2 disease, and 0% in patients with pT3/pT4 disease. The 5-year survival rate for pT2 disease according to lymph node involvement was 72.7% in patients with pN0+ pN1+ positive posterior pancreaticoduodenal lymph nodes and positive lymph nodes around the common hepatic artery in the N2 patients and 0% in the patients with positive celiac and SMA lymph nodes in the N2 patient group or the positive paraaortic lymph node group (P < 0.05).

CONCLUSIONS

These results suggest that systemic dissection of N1 lymph nodes, posterior pancreaticoduodenal lymph nodes, and lymph nodes around the common hepatic artery and the portal vein in N2 patients is necessary to improve the prognosis of those patients with pT2 disease without moderate or severe hepatoduodenal ligament invasion.

The role of lymph node dissection in the treatment of gallbladder carcinoma

BACKGROUND

Lymph node involvement is an important prognostic factor in gallbladder carcinoma (GBC). The lymph node involvement pattern, extent, and indications for systematic lymph node dissection for patients with advanced GBC were investigated.

METHODS

Forty-one patients with GBC who underwent radical resection with systematic regional lymph node dissection over the past 11 years were analyzed.

RESULTS

The lymph node metastasis rate was 63.4% overall, 0% in pT1 disease, 61.9% in pT2 disease, and 81.3% in pT3/pT4 disease. When reviewed according to site, the rate was 41.5% in pericholedochal lymph nodes, 22.0% in the lymph nodes around the common hepatic artery and the portal vein, 36.6% in the posterior pancreaticoduodenal lymph nodes, 28% (5/18) in the celiac lymph nodes, 19% (3/ 16) in the superior mesenteric artery (SMA) lymph nodes, and 26% (7/27) in the aortocaval paraaortic lymph nodes. Patients with severe hepatoduodenal ligament invasion had high rates of paraaortic lymph node involvement. The mortality rate was 2.4% (1 of 41 patients) and the 5-year survival rate was 33.1% overall, 100% in patients with pT1 disease, 49.8% in patients with pT2 disease, and 0% in patients with pT3/pT4 disease. The 5-year survival rate for pT2 disease according to lymph node involvement was 72.7% in patients with pN0+ pN1+ positive posterior pancreaticoduodenal lymph nodes and positive lymph nodes around the common hepatic artery in the N2 patients and 0% in the patients with positive celiac and SMA lymph nodes in the N2 patient group or the positive paraaortic lymph node group (P < 0.05).

CONCLUSIONS

These results suggest that systemic dissection of N1 lymph nodes, posterior pancreaticoduodenal lymph nodes, and lymph nodes around the common hepatic artery and the portal vein in N2 patients is necessary to improve the prognosis of those patients with pT2 disease without moderate or severe hepatoduodenal ligament invasion.

Comparative effects of disulfiram and diethyldithiocarbamate against testicular toxicity in rats caused by acute exposure to cadmium

Disulfiram (DSF) and diethyldithiocarbamate (DED) were compared for their protective effects against the testicular toxicity induced by acute exposure to cadmium (Cd) in rats. Rats were injected subcutaneously with CdCl2 126.7 mumol (3 mg) Cd/kgl, and 30 min later they were injected intraperitoneally with DSF (0.05-0.5 mmol/kg) or DED (0.1-1 mmol/kg). The treatment with DSF at dose levels of 0.1-0.5 mmol/kg prevented the increases in testicular lipid peroxidation and calcium (Ca) concentrations and the decreases in testicular weight that were observed at 7 d after Cd injection. DED at dosage levels of 0.2-1 mmol/kg likewise reduced Cd-induced testicular toxicity. An increase in testicular iron (Fe) concentrations at 7 d and sterility at 59 d after Cd injection were almost completely blocked by treatment with DSF or DED at the highest doses, but lower doses of DSF or DED were ineffective. These results indicated that DSF, which is metabolized to DED, had a protective effect against Cd-induced testicular toxicity nearly equivalent to DED at approximately one-half the dose.

Effect of TYB-2285 on antigen-induced accumulation of eosinophils into the peritoneal cavity of rats sensitized with Ascaris suum extract

1. The present study was carried out to investigate the effect of 3,5-bis-(acetoxyacetylamino)-4-chloro-benzonitrile (TYB-2285) on the accumulation of eosinophils in the peritoneal cavity of Wistar rats sensitized with Ascaris suum extract (Asc). 2. Rats were sensitized by IP injection of Asc on day 0 and were challenged by IP injection of Asc on day 7. Antigen challenge caused a specific, delayed infiltration of eosinophils into the peritoneal cavity that was inhibited by PO administration of TYB-2285, but not ketotifen fumarate, in a dose-dependent manner (3-30 mg/kg). 3. TYB-2285 inhibited the infiltration of eosinophils when during the induction phase, but not during the effector phase. The inhibitory effect of TYB-2285 when during the induction phase was stronger than any other antiallergic drugs, such as tranilast, azelastine, ibudilast, repirinast, tazanolast, oxatomide, or pemirolast. 4. Transfer of lymphocytes, but not serum, from sensitized rats to intact rats provoked a remarkable infiltration of eosinophils after the antigen challenge. In the experiment of adoptive transfer in rats, TYB-2285 was effective when given to donor rats. 5. These results demonstrate that TYB-2285 inhibits the accumulation of eosinophils presumably by inhibiting antigen recognition.

The role of lymph node dissection in the treatment of gallbladder carcinoma

BACKGROUND

Lymph node involvement is an important prognostic factor in gallbladder carcinoma (GBC). The lymph node involvement pattern, extent, and indications for systematic lymph node dissection for patients with advanced GBC were investigated.

METHODS

Forty-one patients with GBC who underwent radical resection with systematic regional lymph node dissection over the past 11 years were analyzed.

RESULTS

The lymph node metastasis rate was 63.4% overall, 0% in pT1 disease, 61.9% in pT2 disease, and 81.3% in pT3/pT4 disease. When reviewed according to site, the rate was 41.5% in pericholedochal lymph nodes, 22.0% in the lymph nodes around the common hepatic artery and the portal vein, 36.6% in the posterior pancreaticoduodenal lymph nodes, 28% (5/18) in the celiac lymph nodes, 19% (3/ 16) in the superior mesenteric artery (SMA) lymph nodes, and 26% (7/27) in the aortocaval paraaortic lymph nodes. Patients with severe hepatoduodenal ligament invasion had high rates of paraaortic lymph node involvement. The mortality rate was 2.4% (1 of 41 patients) and the 5-year survival rate was 33.1% overall, 100% in patients with pT1 disease, 49.8% in patients with pT2 disease, and 0% in patients with pT3/pT4 disease. The 5-year survival rate for pT2 disease according to lymph node involvement was 72.7% in patients with pN0+ pN1+ positive posterior pancreaticoduodenal lymph nodes and positive lymph nodes around the common hepatic artery in the N2 patients and 0% in the patients with positive celiac and SMA lymph nodes in the N2 patient group or the positive paraaortic lymph node group (P < 0.05).

CONCLUSIONS

These results suggest that systemic dissection of N1 lymph nodes, posterior pancreaticoduodenal lymph nodes, and lymph nodes around the common hepatic artery and the portal vein in N2 patients is necessary to improve the prognosis of those patients with pT2 disease without moderate or severe hepatoduodenal ligament invasion.

Medicinal foodstuffs. V. Moroheiya. (1): Absolute stereostructures of corchoionosides A, B, and C, histamine release inhibitors from the leaves of Vietnamese Corchorus olitorius L. (Tiliaceae)

Three new ionone glucosides named corchoionosides A, B, and C were isolated from the leaves of Corchorus olitorius, commonly called "moroheiya" in Japanese, together with seven known compounds, an ionone glucoside (6S,9R)-roseoside, a monoterpene glucoside betulalbuside A, two flavonol glucosides astragalin and isoquercitrin, two coumarin glucosides scopolin and cichoriine, and chlorogenic acid. The absolute stereostructures of corchoionosides A, B, and C were determined by chemical and physiochemical evidence, which included the result of application of a modified Mosher's method, the CD helicity rule, and chemical correlation with (6S,9R)-roseoside. Corchoionosides A and B and (6S,9R)-roseoside were found to inhibit the histamine release from rat peritoneal exudate cells induced by antigen-antibody reaction.

Role of protein kinase a pathway in epidermal growth factor-induced liver cell repair

To gain a better understanding of the mechanisms that control the repair process in the injured liver, the actions of epidermal growth factor (EGF) and protein kinase A (PKA) were studied. Normal rat liver cells (clone 9) were grown to confluence. Standardized excisional wounds were made with a razor blade. The extent of hepatocyte migration into the wound was measured and determined at specific time intervals using a computerized digital analyzing system. Immunostaining of F-actin was performed with a fluorescein-labeled phalloidin. EGF significantly stimulated liver cell migration, whereas specific EGF-neutralizing antibody inhibited the EGF-induced migration. Agents that activate PKA at different stages of the PKA activation pathway, including 3-isobutyl-1-methylxanthine (IBMX), forskolin, and cholera toxin, inhibited EGF-induced migration. EGF triggered formation of actin stress fibers. PKA-activating agents inhibited actin stress fiber formation and stretching of cells at the wound margin. The following conclusions were drawn: (1) In excisional wounds of hepatocyte monolayers, both EGF and PKA exert action on actin microfilaments, which are stretched by EGF and inhibited by PKA; (2) the enhanced repair of wounded hepatocyte monolayers by EGF is blocked by activation of the PKA pathway at various levels; and (3) these actions of EGF and PKA indicate their important regulatory roles in controlling the rate of hepatocyte migration and restitution following the creation of excisional wounds.

Evaluation of the rodent micronucleus assay in the screening of IARC carcinogens (groups 1, 2A and 2B) the summary report of the 6th collaborative study by CSGMT/JEMS MMS. Collaborative Study of the Micronucleus Group Test. Mammalian Mutagenicity Study Group

To assess the correlation between micronucleus induction and human carcinogenicity, the rodent micronucleus assay was performed on known and potential human carcinogens in the 6th MMS/CSGMT collaborative study. Approximately 100 commercially available chemicals and chemical groups on which there was little or no micronucleus assay data were selected from IARC (International Agency for Research on Cancer) Groups 1 (human carcinogen), 2A (probable human carcinogen) and 2B (possible human carcinogen). As minimum requirements for the collaborative study, 5 male mice were treated by intraperitoneal injection or oral gavage once or twice with each chemical at three dose levels, and bone marrow and/or peripheral blood was analyzed. Five positives and 2 inconclusives out of 13 Group 1 chemicals, 7 positives and 5 inconclusives of 23 Group 2A chemicals, and 26 positives and 6 inconclusives of 67 Group 2B chemicals were found. Such low positive rates were not surprising because of a test chemical selection bias, and we excluded well-known micronucleus inducers. The overall evaluation of the rodent micronucleus assay was based on the present data combined with published data on the IARC carcinogens. After merging, the positive rates for Groups 1, 2A and 2B were 68.6, 54.5 and 45.6%, respectively. Structure-activity relationship analysis suggested that the micronucleus assay is more sensitive to the genetic toxicity of some classes of chemicals. Those to which it is sensitive consist of (1) aziridines and bis(2-chloroethyl) compounds; (2) alkyl sulfonate and sulfates; (3) acyl-type N-nitroso compounds; (4) hydrazines; (5) aminobiphenyl and benzidine derivatives; and (6) azo compounds. Those to which it is less sensitive consist of (1) dialkyl type N-nitroso compounds; (2) silica and metals and their compounds; (3) aromatic amines without other functional groups; (4) halogenated compounds; and (5) steroids and other hormones. After incorporation of structure-activity relationship information, the positive rates of the rodent micronucleus assay became 90.5, 65.2 and 60.0% for IARC Groups 1, 2A and 2B, respectively. Noteworthy was the tendency of the test to be more sensitive to those carcinogens with stronger evidence human carcinogenicity.

Ethyl nitrosourea and methyl methanesulfonate mutagenicity in sperm and testicular germ cells of lacZ transgenic mice (Muta Mouse)

The germ cell mutagens ethyl nitrosourea (ENU) and methyl methanesulfonate (MMS), were tested for their genotoxicity in sperm cells and testicular germ cells using lacZ transgenic mice (Muta Mouse). Eight- to 10-week-old Muta mice were treated with ENU (150 mg/kg) or MMS (40 mg/kg) by intraperitoneal injection. Three and 14 days after treatment, testes and sperm were collected for lacZ mutation analysis. Sperm were isolated from the epididymis and vas deferens by washing out the minced tissue. Germ cell DNA was isolated from testicular germ cells and sperm with the help of 2-mercaptoethanol, and the target lacZ gene, which is integrated into a lambda shuttle vector, was recovered by in vitro packaging. The resultant phages were allowed to infect to E. coli C (galE), and the lacZ mutant plaques were dominantly selected on a plate containing phenyl-beta-D-galactoside. Spontaneous mutant frequencies (MF) in vehicle-treated control mice were approximately 1 x 10(-5) and 3 x 10(-5) in testicular germ cells and sperm, respectively, at both sampling times. ENU treatment increased the MF in the testicular germ cells to 5 x 10(-5) on days 3 and 14, but did not affect sperm MF. MMS was not mutagenic in either tissue. The peripheral blood micronucleus assay was performed on the same animals 48 h after treatment, and strong inductions of micronucleated reticulocytes (MNRETs) were observed in both ENU- and MMS-treated mice. These data suggest that agents mutagenic to premeiotic germ cells, e.g., ENU, can be detected by transgenic mutation assay system using germ cells isolated from the testis. On the other hand, those mutagenic to postmeiotic cells, e.g., MMS, are insensitive in the assay system.

Germ cell mutagenesis in lacZ transgenic mice treated with methyl methanesulfonate

Mutagenesis induced by methyl methanesulfonate (MMS), a germ cell mutagen, in the testis and the sperm isolated from epididymis and vas deferens have been investigated using lacZ transgenic mice (Muta Mouse). Male Muta Mice were injected intraperitoneally with MMS at a dose of 80 mg/kg, a potent dominant lethal dose. Animals were killed on days 3 and 7 (Experiment 1) or days 10 and 14 (Experiment 2) after the treatment. Mutant frequencies (MFs) in the testis, sperm and spleen (Experiment 2 only) were analyzed by the positive selection system using E. coli C (GalE-) strain and phenyl beta-D-galactoside. The spontaneous MFs in the testis and sperm were 2.0-3.1 x 10(-5). No induction of mutation in the testis or sperm of the MMS-treated groups was observed at any sampling point. In the spleen, the spontaneous MF was approximately twice as high as that in the germ cells although the MF at each sampling point was almost the same as the spontaneous MF. MMS is known as a potent clastogen from the results of the dominant lethal assay and the micronucleus assay. The reason for the discrepancy between the results of these assays and the present results may have been insensitivity of the in vitro packaging to large deletion due to the failure to rescue the large deleted gene. It is suggested that the transgenic mouse assay using the in vitro packaging can not replace the dominant lethal assay in the case of MMS.

Effect of TYB-2285 on passive cutaneous anaphylaxis in rats

1. TYB-2285 (1-30 mg/kg p.o.) inhibited ovalbumin (OA)- and dinitrophenyl-Ascaris (DNPAs)-induced passive cutaneous anaphylaxis (PCA) in a dose-dependent manner. 2. The ED50 of TYB-2285 and ketotifen fumarate on OA-induced PCA were 0.5 and 3.9 mg/kg, respectively. The ED50 of TYP-2285 and amlexanox on DNP-As-induced PCA were 3.5 and 0.9 mg/ kg, respectively. 3. TYB-2285 (3-30 mg/kg p.o.) inhibited histamine consumption at the PCA site. 4. Unlike cyproheptadine or amlexanox, TYB-2285 (30 mg/kg p.o.) did not inhibit histamine-, serotonin-, ascites-, 48/80-, or A23187-induced capillary permeability. It inhibited dextran-induced capillary permeability slightly. 5. These results demonstrate that TYB-2285 inhibits PCA by inhibiting histamine release, although it does not inhibit capillary permeability.

[Pleural B cell lymphoma presenting as paraplegia]

A 54-year-old man felt pain on the right side of his chest. Two months later, paraplegia developed. A chest CT scan revealed a pleural effusion and a mass lesion along the right parietal pleura. The lesion extended directly into the adjacent part of the spinal canal and compressed the spinal cord. Cytologic examination of the pleural effusion revealed atypical lymphoid cells, and examination of a transcutaneous biopsy specimen showed monotonous atypical B lymphocytes. The diagnosis was pleural malignant lymphoma. Chemotherapy induced a partial remission, but 14 months after the first examination he died of central nervous system involvement. Pleural lymphoma can directly compress the spinal cord and cause paraplegia. Early diagnosis and therapy greatly affect the outcome in patients with spinal cord compression.

Effects of TYB-2285 on the accumulation of eosinophils in the airway induced by antigen exposure in actively sensitized brown Norway rats

1. The effect of TYB-2285 on the antigen-induced accumulation of eosinophils into the airway was investigated in two models (inhalant sensitization and noninhalant sensitization) using Brown Norway (BN) rats. 2. In the method of inhalant sensitization, BN rats were sensitized by weekly exposure to ovalbumin (OA). The accumulation of eosinophils was inhibited by the oral administration of TYB-2285 for the first 2 days of each sensitization in a dose-dependent manner. 3. With noninhalant sensitization, BN rats were sensitized by i.m. injection of OA and i.p. injection of killed Bordetella pertussis. The accumulation of eosinophils was inhibited by TYB-2285 in a dose-dependent manner, when TYB-2285 is given p.o. 5 mm before and 5 hr after the antigen exposure. Moreover, this accumulation of eosinophils was inhibited by a single administration of TYB-2285 5 hr after the antigen exposure, presumably when the mast cell degranulation was already finished. 4. In the method with noninhalant sensitization, the accumulation of eosinophils was not inhibited by mast cell stabilizers such as ketotifen, tranilast, or DSCG. 5. The present study demonstrates that TYB-2285, unlike other mast cell stabilizers, inhibits the antigen-induced accumulation of eosinophils into the airway. It also suggests that this drug might be effective in asthmatic patients.

Effect of TYB-2285 on lung anaphylaxis in actively sensitized rats

1. We examined the effect of TYB-2285 on the acute phase and the late phase of lung anaphylaxis in rats. 2. TYB-2285 (3-30 mg/kg PO) inhibited antigen-induced bronchoconstriction and TxB2 production during the acute phase of lung anaphylaxis in a dose-dependent manner. 3. Ketotifen fumarate (30 mg/kg p.o.) inhibited bronchoconstriction and TxB2 production less potently than TYB-2285. 4. TYB-2285 (30 mg/kg p.o.) inhibited the accumulation of neutrophils during the late phase of lung anaphylaxis significantly without a significant change in total cells. 5. Hydrocortisone acetate (100 mg/kg p.o.) inhibited the accumulation of total cells as potent as neutrophils.

Two isoforms of orthodenticle-related proteins (HpOtx) bind to the enhancer element of sea urchin arylsulfatase gene

The sea urchin (Hemicentrotus pulcherrimus) arylsulfatase (HpArs) gene, expressed specifically in aboral ectoderm, contains a 229-bp enhancer in its first intron that is required for the activation of HpArs gene expression. Deletion analysis shows that a tandem repeat of orthodenticle-related protein (Otx) binding sites are responsible for the activity of this enhancer. Gel mobility shift analysis reveals that three types of Otx-proteins, which show different mobilities in gel shift assays, form complexes with the enhancer. Band I appears before hatching and gradually decreases by the gastrula stage. Band III appears at the blastula stage and Band II appears at the mesenchyme blastula stage; the levels of Band II and III remain constant until the gastrula stage. Two distinct types of HpOtx cDNA clones have been isolated from cDNA libraries of unfertilized eggs and gastrulae. Nucleotide sequences of the homeobox and downstream regions are well conserved in the two types of HpOtx cDNAs, while the region upstream from the homeobox has different nucleotide sequences. By genomic Southern blot analysis, only a single copy of HpOtx gene is detectable in the Hp genome, making it likely that two HpOtx isoforms are generated from the same gene. Results from Northern blot analysis confirm the presence of two types of HpOtx transcripts. Transcriptional regulation of the HpArs gene may, in part, be carried out through switching of Otx isoforms.

Effects of dithiocarbamates on toxicity of cadmium in rat primary hepatocyte cultures

The protective effects of N-benzyl-D-glucamine dithiocarbamate (BGD) and N-p-hydroxymethylbenzyl-D-glucamine dithiocarbamate (HBGD) on the toxicity of Cd in the rat primary hepatocyte cultures were studied. Cytotoxicity was assessed by measuring cell viability, extra cellular lactic dehydrogenase (LDH) activity, and intracellular lipid peroxidation and active oxygen species. Primary hepatocyte cultures were treated with 109CdCl2 (5, 10 or 50 microM Cd and 1.7 KBq of 109Cd/well) for 30 min or 4 h. BGD or HBGD was added to the culture medium to make the final concentration of 100 microM and incubated for 4.5 h in 30 min Cd exposure or 1 h in 4 h Cd exposure. Decreases in the hepatocyte viability caused by all Cd exposure concentrations were significantly prevented by treatment with BGD or HBGD. The treatment with the chelating agents for 4.5 h after Cd exposure for 30 min significantly prevented increases in extracellular LDH activity. Increases in the lipid peroxidation in hepatocytes exposed to Cd for 30 min or 4 h were prevented significantly by treatment with BGD or HBGD for 4.5 h or 1 h, respectively. Moreover, the increases in the level of active oxygen species caused by Cd exposure for 30 min were significantly prevented by treatment with the chelating agents for 1.5 h. These findings suggest that BGD and HBGD protect against the cytotoxicity of Cd in rat primary hepatocyte cultures and that the protective effects of chelating agents presumably result from a decrease in the Cd level, the effective sequestration of the reactive Cd ion, and the direct preventive effect on the active oxygen species in the hepatocytes.

Testosterone pretreatment mitigates cadmium toxicity in male C57 mice but not in C3H mice

Previous work has indicated that testosterone pretreatment protects against cadmium-induced toxicity in male rats while other data indicate that pretreatment of mice with testosterone offers no such protection against cadmium. Since cadmium toxicity may vary widely with species and strain, we examined the effect of testosterone pretreatment on cadmium toxicity in two strains of mice, one that is sensitive (C3H) and one that is resistant (C57) to cadmium toxicity. A single sc injection of 20 micromol CdCl2/kg to C3H mice or 45 micromol CdCl2/kg to C57 mice proved very toxic, causing 50%, and 44% mortalities, respectively. However, when C57 mice were pretreated with testosterone (5 mg/kg, s.c., at - 48, - 24, and 0 h) prior to cadmium (45 micromol/kg), complete resistance to cadmium-induced lethality developed. Testosterone had no effect on cadmium-induced lethality in C3H mice. Testosterone prevented extensive hepatocellular damage caused by cadmium in C57 mice and also significantly reduced cadmium-induced elevations in serum lactate dehydrogenase (LDH) activity and blood urea nitrogen (BUN), which are indicators of hepatic and renal function, respectively. The toxicokinetics of cadmium were apparently not affected by testosterone pretreatment, as the distribution of cadmium to liver in either strain was unchanged by the steroid. Cadmium-induced metallothionein (MT) levels in liver and kidney of C57 mice were increased in testosterone-pretreated mice given the higher doses of metal but no such enhancement of MT synthesis occurred in C3H mice. This increase in MT may provide some level of protection against cadmium toxicity in the C57 mice. These results indicate that testosterone pretreatment prevents toxicity of cadmium in male C57 mice, possibly through enhancement of MT synthesis, but has no effect in male C3H mice.

Metabolic engineering for the production of carotenoids in non-carotenogenic bacteria and yeasts

The crt gene clusters responsible for the biosynthesis of carotenoids such as lycopene, beta-carotene and astaxanthin have been isolated from carotenogenic bacteria such as Erwinia species and the marine bacterium Agrobacterium aurantiacum. The functions of the individual genes have been identified. The first substrate of the enzymes encoded by the Erwinia crt clusters is farnesyl pyrophosphate which is not only the precursor for carotenoid biosynthesis but also sterols, dolichols and other numerous isoprenoid compounds. Escherichia coli does not naturally synthesize carotenoids, but by using the carotenogenic genes recombinant strains accumulating lycopene, beta-carotene and astaxanthin have been produced. Other non-carotenogenic bacteria such as Zymomonas mobilis have also been engineered to produce beta-carotene by the introduction of the corresponding crt genes. A gene capable of enhancing carotenoid levels in E. coli has also been isolated from cDNA libraries of the yeast Phaffia rhodozyma and the green alga Haematococcus pluvialis. This gene has been found to encode an isopentenyl pyrophophate isomerase. It has further been shown that the edible yeasts Candida utilis as well as Saccharomyces cerevisiae, which possess no carotenoid biosynthetic pathway, acquire the ability to produce carotenoids, when the carotenogenic genes are expressed under the control of yeast-derived promoters and terminators. It has been observed in the yeasts S. cerevisiae and C. utilis carrying the lycopene biosynthesis genes that ergosterol content is decreased by 10 and 35%, respectively. It is therefore likely that the carbon flux for the ergosterol biosynthesis has been partially directed from farnesyl pyrophosphate to a new pathway for the lycopene biosynthesis. Further, the expression of a truncated gene which codes for the catalytic domain of the endogenous 3-hydroxy-3-methylglutaryl coenzyme. A reductase, has been found to be effective for enhancing carotenoid levels in the yeast C. utilis.