Anticentromere antibody as a risk factor for cancer in patients with systemic sclerosis

This study has estimated the cancer risk among patients with systemic sclerosis (SSc) using a population-based analysis. Using the inpatient and outpatient registries for patients at Kyushu University Hospital between 1982 and 1996, standardised incidence rates (SIRs) (ratio of observed-to-expected cancers) were calculated in 43 patients with SSc, 24 patients with polymyositis (PM) and 17 patients with dermatomyositis (DM). Risk factors predisposing to cancers were also investigated in the SSc patients. Compared with the Japanese general population, the SIR for developing cancer in SSc patients was 5.1 (95% confidence interval (CI), 1.7-10.8), while the SIRs for cancer in the PM and DM groups were 4.7 (95% CI, 1.5-10.3) and 61.2 (95% CI, 46.8-77.6), respectively. A statistically significant risk factor for cancers in the SSc patients was positivity for anticentromere antibody (ACA) (p<0.05), while the erythrocyte sedimentation rate, serum lactate dehydrogenase concentration, serum gamma-globulin concentration, titre of antinuclear antibody and positivity for antitopoisomerase I antibody were not associated with cancer in SSc. Our population-based study confirms the increased risk of cancer among patients with SSc in Japan and provides new evidence that positivity for ACA should be considered as a risk factor for cancer in future monitoring of patients.

Synthesis of 2-substituted 3-nitro-1,2-dihydropyridines by heterocyclic annulation reactions of a sec-nitrodienamine with aldehyde compounds

The reaction of a sec-nitrodienamine 3 with aldehyde compounds afforded 2-substituted 3-nitro-1,2-dihydropyridines 5, providing a heterocyclic annulation reaction.

Modulation of chemokine expression during ischemia/reperfusion in transgenic mice overproducing human glutathione peroxidases

Renal ischemia/reperfusion (I/R) injury is a major cause of kidney damage. There is accumulating evidence that inflammatory reactions are involved in the pathogenesis of this process. Our studies demonstrate that transgenic mice overexpressing human extracellular and intracellular glutathione peroxidases (GP) are protected against kidney I/R injury. Importantly, significant reduction in neutrophil migration was observed in GP mice compared with nontransgenic mice. Analysis of signaling molecules mediating neutrophil activation and recruitment indicates reduction in the level of KC and macrophage inflammatory protein-2 chemokine expression in transgenic animals. The molecular mechanism mediating this effect appears to involve repression of NF-kappaB activation at the level of IkappaBalpha and IkappaBbeta degradation. In the case of IkappaBalpha, no apparent phosphorylation was detected. These results suggest that IkappaBalpha proteolysis is triggered during the renal I/R pro-oxidant state by a still unknown mechanism, which might be different from other stimuli. A central role of NF-kappaB in CXC chemokine activation was demonstrated in cell culture anoxia/ATP repletion experiments as a model of I/R. The data presented indicate the important role of GP-sensitive signal transduction pathways in the development of inflammatory response and tissue injury during I/R.

Ulcerative colitis and colorectal cancer: a follow-up study in Fukuoka, Japan

BACKGROUND

Our goal was to study the higher death rate and the causes of such deaths among ulcerative colitis (UC) patients in the Japanese population, and to compare our findings in such cases with those for Crohn's disease (CD).

METHODS

In all, 174 UC (male/female: 54/120) and 66 CD (34/32) patients who were registered for the research promotion programme in Fukuoka prefecture (1971-1981) were traced up to the end of 1994. The standardized mortality ratios (SMR) were calculated based on the death rates of the Japanese population by age, sex and calendar year.

RESULTS

The overall follow-up rate was 96.7%. Among the UC patients, the SMR for all causes were 0.84 (95% CI: 0.11-4.31) for men; 1.05 (95% CI: 0.08-4.69) for women; and 0.94 (95% CI :0.09-4.50) for both sexes combined. When excluding deaths due to colorectal cancer, the SMR for the same groups were 0.43, 0.94 and 0.67, respectively. The SMR for both sexes were 1.82 (95% CI: 0.17-5.96) for malignant neoplasms and 9.93 (95% CI: 4.67-17.3) for colorectal cancer. Patients who died from colorectal cancer showed onset at a younger age (mean: 25.5 years) as well as a longer disease course of UC (mean: 17.0 years). Regarding the CD patients, the SMR for all causes were 1.75 (95% CI: 0.15-5.75) for both sexes. Most deaths were caused by gastrointestinal complications.

CONCLUSIONS

An excess mortality from colorectal cancers was indicated in the UC patients, especially in males. The overall SMR in male UC patients decreased by 50% when the deaths from colorectal cancer were excluded. The excess mortality in those with CD over UC patients was attributed to gastrointestinal complications rather than malignant diseases. Some carcinogenic factors therefore seem most likely to exist in the pathogenesis of UC.

Infection of the Entomopathogenic Nematode, Steinernema carpocapsae, as Affected by the Presence of Steinernema glaseri

The infection behavior of Steinernema carpocapsae infective juveniles (IJ) was investigated in the presence and absence of S. glaseri. Mixed inoculation of S. carpocapsae with S. glaseri IJ significantly raised the nictation rates of S. carpocapsae IJ. Significantly more S. carpocapsae IJ migrated to the host insect in the mixed inoculation with S. glaseri IJ on agar plates. More S. carpocapsae IJ penetrated into the host insect placed 2 cm below the surface in the mixed inoculation with S. glaseri IJ. More S. glaseri than S. carpocapsae IJ penetrated into hosts placed 7 cm deep. Irrespective of host location, the male ratio of S. carpocapsae IJ established in the host body was always higher in the mixed inoculation with S. glaseri IJ.

Excellent acceleration of the Diels-Alder reaction by microwave irradiation for the synthesis of new fluorine-substituted ligands of NMDA receptor

A series of 6,11-ethanobenzo[b]quinolizinium derivatives was synthesized through the Diels-Alder reaction between azoniaanthracne and the corresponding 1,1-disubstituted olefin. After a systematic investigation for achieving rapid synthesis, it was found that the reaction is accelerated in polar media such as H2O and trifluoroethanol. In particular, excellent acceleration was effected by microwave irradiation. The new fluorine-substituted ligands thus obtained exhibited potential affinity toward NMDA receptors.

Optimal protein requirements during the first 2 weeks after the onset of critical illness

OBJECTIVE

To obtain optimal protein requirements in critically ill sepsis or trauma patients during the first 2 wks after admission to the intensive care unit.

DESIGN

Retrospective study.

SETTING

Department of critical care medicine at a teaching hospital.

PATIENTS

Immediate posttrauma patients or severely septic patients.

INTERVENTIONS

In vivo neutron activation analysis was used to measure changes in total body protein over a 10-day period which began as soon as the patients were hemodynamically stable. The patients (trauma, n=18; sepsis, n=5) were divided into three groups according to the average daily protein intakes. Because the patients were overhydrated (approximately 10 L) and had variable amounts of body fat, the protein intakes were indexed to normally hydrated (corrected) fat-free mass (FFMc): Groups A, B, and C received an average of 1.1, 1.5, and 1.9 g/kg FFMc/day protein, respectively.

MEASUREMENTS AND MAIN RESULTS

Overall, the average loss of total body protein was 1.2=0.7 (SD) kg. Changes in total body protein were significantly (p=.011) different between the three groups. The loss of body protein was significantly more in group A compared with groups B (p=.013) and C (p=.023). When the protein intake was increased from 1.1 g/kg FFMc/day to 1.5 g/kg FFMc/day, protein loss was halved. Further increase in protein intake up to 1.9 g/kg FFMc/day resulted in no further improvement. An intake of 1.5 g/kg FFMc/day was equivalent to 1.0 g/day/kg of body weight measured at the beginning of the study.

CONCLUSIONS

Current recommended protein requirements of 1.2 to 2.0 g/kg of body weight/day are excessive if they are indexed to the body weight measured soon after the onset of critical illness. Because individual patients have varying degrees of overhydration early in the illness onset, we suggest that the intensivist should obtain information on preillness body weight and prescribe 1.2g of protein/kg body weight/day. If information is not available, 1.0g of protein/day/kg of measured body weight will give a fair approximation to optimal protein requirements.

Effect of combination therapy with a methionine-mitomycin C conjugate and a methionine-deficient diet on tumor growth

BACKGROUND

We investigated effects of a combination therapy of a methionine-mitomycin C conjugate (M-M conj) and methionine-free nutrition both in vitro and in vivo, compared to mitomycin C (MMC) administration alone.

MATERIALS AND METHODS

The human esophageal cancer cell line, KE-3, incubated in either standard or methionine-free media, was treated with phosphate buffered saline (PBS), M-M conj in PBS, or MMC in PBS. The rate of cell survival was determined. The tumor bearing mice were maintained on either a standard or methionine-free diet (MFD) and treated with PBS, MMC, or M-M conj.

RESULTS

The lowest tumor cell survival rate was found with the M-M conj plus methionine-free media at every dose tested (p < 0.05). Tumor weight was significantly lower with the M-M conj plus MFD than in any other group (p < 0.003).

CONCLUSION

Methionine targets MMC to tumor during administration of MFD.

Pioglitazone reduces smooth muscle cell density of rat carotid arterial intima induced by balloon catheterization

The effect of pioglitazone on balloon catheterization-induced carotid arterial intimal thickening lesion of male Wistar fatty rats and its littermates (Wistar lean rats) was investigated. Pioglitazone was administered via gastric tube at 10 mg/kg/day to 12-week-old rats for 7 days. Age-matched rats without pioglitazone were used as respective controls. Each rat was catheterized using a balloon catheter inserted from the left femoral artery to the left common carotid artery, and the endothelium in the left common carotid artery was denuded. Rats were then treated with pioglitazone for 14 days post catheterization and the left common carotid artery was removed and stained with Elastica-Masson and anti-alpha-smooth muscle actin antibody. In addition, for smooth muscle cell (SMC) culture, pioglitazone was administered at 10 mg/kg/day for 28 days to a separate group of 12-week-old rats, and the aortic medial outgrowth rate of their SMCs was measured. Age-matched rats without pioglitazone were prepared as respective controls. In comparison with the area ratio of the thickened intima/media of fatty rats without treatment, those of fatty rats with treatment and lean rats without treatment were significantly decreased by approximately 60%, and also that of lean rats with treatment to 27%. With anti-alpha-smooth muscle actin antibody staining, almost all cells present in intimal thickening were positive. Treatment with pioglitazone reduced the amount of anti-alpha-smooth muscle actin antibody-staining cells. In addition, the outgrowth rate of SMCs at day 10 compared to that in fatty rats without treatment decreased to 42% in fatty rats with treatment, 29% in lean rats without treatment and 23% in lean rats with treatment, respectively. Therefore, pioglitazone has an inhibitory effect on the growth of SMCs, and consequently suppressed carotid intimal thickening. Furthermore, this inhibitory effect was enhanced in diabetes.

Effect of methionine-free total parenteral nutrition and insulin-like growth factor I on tumor growth in rats

The objectives of this study were to evaluate the effect of insulin-like growth factor I (IGF-I) on the fractional synthesis rate (FSR) of muscle and whole body protein breakdown rate (WPBR) during methionine-free total parenteral nutrition (MTPN). We also determined whether the inhibition of endogenous methionine availability reduced tumor protein synthesis. AH109A hepatoma cells were inoculated onto the backs of Donryu rats on day 0. On day 10, the rats were catheterized for TPN and assigned to one of four groups: 1) standard TPN (STPN), 2) STPN + IGF-I, 3) MTPN, or 4) MTPN + IGF-I. The addition of IGF-I to MTPN reduced the loss of body weight by both increasing muscle FSR and reducing WPBR. The tumor FSR did not differ between MTPN + IGF-I and MTPN. The methionine extraction ratio from the liver was negative with MTPN + IGF-I but positive in the other groups. We concluded that IGF-I blockage of endogenous methionine release from peripheral protein sites was associated with a shift to liver-derived methionine, with no change in tumor growth in MTPN-treated rats.

Bifidobacterium longum, a lactic acid-producing intestinal bacterium inhibits colon cancer and modulates the intermediate biomarkers of colon carcinogenesis

The human colon can be described as a complex microbial ecosystem, comprising several hundred bacterial species. Some of these enteric bacteria are beneficial to the host and have been shown to exert antimutagenic and anticarcinogenic properties. We have investigated the colon tumor inhibitory activity of Bifidobacterium longum, a lactic acid-producing enterobacterium. The modifying effects of this lactic culture on colonic mucosal and/or tumor cell proliferation, ODC activity and ras-p21 oncoprotein expression in colon carcinogenesis were also analyzed. Male F344 rats were fed a modified AIN-76A diet containing 0 or 2% lyophilized cultures of B. longum and s.c. administered azoxymethane (AOM) dissolved in normal saline at a dose of 15 mg/kg body wt, once weekly for 2 weeks. Vehicle controls received an equal volume of normal saline s.c. Animals were maintained on control or experimental diets until termination of the study. Animals intended for analysis of cell proliferation were killed 20 weeks after the second AOM injection, whereas animals intended for colon tumor analysis and measurement of ODC activity and ras-p21 expression were killed 40 weeks after the last AOM injection. The data demonstrate that dietary administration of lyophilized cultures of B. longum resulted in significant suppression of colon tumor incidence and tumor multiplicity and also reduced tumor volume. Results also revealed that ingestion of B. longum significantly inhibited AOM-induced cell proliferation, ODC activity and expression of ras-p21 oncoprotein. Data suggest that oral administration of probiotic B. longum exerts strong antitumor activity, as indicated by modulation of the intermediate biomarkers of colon cancer, and consequently reduced tumor outcome.

Glutamine and arginine metabolism in tumor-bearing rats receiving total parenteral nutrition

Arginine supplementation increases glutamine levels in muscle and plasma. Since glutamine production is increased in catabolic states, these observations prompted us to investigate whether the flux of arginine to glutamine was increased in tumor-bearing (TB) rats, and we measured the synthesis rate of glutamine from arginine in control versus TB rats receiving standard total parenteral nutrition (TPN) solution. Male Donryu rats (N = 36; body weight, 200 to 225 g) were divided into two groups, control and TB rats. Yoshida sarcoma cells (1 x 10(6)) were inoculated into the back of the rats (n = 18) subcutaneously on day 0. The rats were given free access to water and rat chow. On day 5, all animals, including non-TB rats (n = 18), were catheterized at the jugular vein and TPN was begun. On day 10, TPN solution containing either U-14C-glutamine (2.0 microCi/h) or U-14C-arginine (2.0 microCi/h) was infused as a 6-hour constant infusion. At the end of the isotope infusion, plasma was collected to determine the glutamine production rate in rats receiving U-14C-glutamine, and the ratio of specific activity of glutamine to specific activity of arginine was measured in rats receiving U-14C-arginine. Only 2 g tumor caused a decrease in glutamine levels and an increase in glutamine and arginine production. The low flux rate of arginine to glutamine was observed in control rats (Arg to Gln, 41.0 +/- 11.9 mumol/kg/h). On the other hand, TB caused a significant increase in Arg to Gln compared with the control (213.3 +/- 66.1 mumol/kg/h, P < .01 v control). An increase in the flux rate of Arg to Gln was associated with an enhancement in the ratio of specific activity of ornithine to specific activity of arginine in TB rats (control 51.5% +/- 10.9% v 77.4% +/- 8.9%, P < .05). We conclude that (1) glutamine and arginine metabolism is altered with very small tumors, (2) although the flux of Arg to Gln was increased in TB and rats, the small increase in Arg to Gln cannot explain the observed large increase in Gln production.

Suppression of neointimal thickening by a newly developed HMG-CoA reductase inhibitor, BAYw6228, and its inhibitory effect on vascular smooth muscle cell growth

1. The aim of this study was to determine whether BAYw6228 (BAYw), a newly developed 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase inhibitor, could suppress an atherogenic process such as intimal thickening by a mechanism other than lowering the level of serum cholesterol. 2. First, we evaluated the in vitro effect of BAYw on the proliferation of vascular smooth muscle cells (SMC) from various species: Sprague-Dawley (SD) rats. New Zealand (NZ) white rabbits, intimal cells from Watanabe hereditary hyperlipidemic (WHHL) rabbit and SMC from the new-born human aorta. The increasing rate of total protein content of these cells was inhibited by the addition of BAYw in a dose-dependent fashion. In the presence of 2% foetal calf serum (FCS), the value of IC50 was 1.0 microM in SD rats, 2.1 microM in NZ white rabbits, and 0.3 microM in WHHL rabbits. With human SMC, the value was 0.02 microM in the presence of 10% FCS and 0.2 microM with a mixture of growth factors. 3. Based on these above in vitro findings, we next examined the in vivo effect of the agent to determine whether it could suppress rabbit intimal thickening induced by balloon catheterization. A balloon catheter was inserted from a peripheral branch of the left external carotid artery to the aorta to denude the endothelium of the left common carotid artery in Japanese white rabbits. After 12 days they were divided into control and BAYw groups. The former were subcutaneously injected with saline and the latter with BAYw 1 mg kg-1 day-1. Two days after the beginning of treatment, a second balloon injury was performed to the previously injured left common carotid artery in both groups. After another two weeks, the left common carotid artery was removed and variously stained. Although the total serum cholesterol in the BAYw group was significantly lower than in the control (P < 0.05), the difference was not enough to affect intimal thickening. In addition, the BAYw group had a smaller intima/media ratio than the control group, decreasing to 45% of control (P < 0.05). By anti-alpha smooth muscle actin antibody staining, these intimal thickening areas were entirely occupied by SMCs, and their amount was attenuated by BAYw. By anti-rabbit macrophage antibody (RAM 11) staining, the number of positive cells in the intimal thickening was markedly decreased in the BAYw group compared to control (P < 0.01). 4. These results indicate that BAYw has an inhibitory effect on intimal thickening by attenuating intimal SMC proliferation and infiltration of macrophages, suggesting that BAYw could be effective in the prevention of the progression of atherosclerotic plaque-like restenosis after angioplasty.

BAYw6228 suppresses accumulation of macrophages in balloon-induced intimal thickening of rabbit carotid artery

To determine the in vivo activity of BAYw6228 (BAYw), a newly developed 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase inhibitor, we examined its effect on balloon catheterization-induced carotid arterial intimal thickening in Japanese white rabbits. In all rabbits weighing approximately 3.5 kg, a balloon catheter was inserted from a peripheral branch of the left external carotid artery to the aorta in order to denude the endothelium of the left common carotid artery. At day 12, they were divided into control and BAYw groups. The latter were subcutaneously injected with BAYw, 1 mg/kg/day, for the following 17 days. At day 15, the second balloon catheterization was performed in the same left common carotid artery in both groups. After another two weeks, the left common carotid artery was removed and stained with Elastica-Masson (EM) and anti-rabbit macrophage antibody (RAM 11). With RAM 11 staining, the number of positive cells in the intimal thickening was markedly decreased in the BAYw group compared with the control group (P < 0.01). Compared with the area ratio of the thickened intima/media layer of the control group, that of the BAYw group was significantly decreased to 45% (P < 0.05). These results indicate that BAYw prevents accumulation of macrophages and consequently contributes to the inhibition of intimal thickening induced by balloon catheterization.

Effect of fentanyl citrate anesthesia on protein turnover in patients with esophagectomy

The objectives of this study were to determine whether high doses of fentanyl anesthesia reduced the surgical stress level and to elucidate the effect of fentanyl anesthesia on protein turnover after esophagectomy. Seventeen male patients with esophageal cancer were divided into two groups, conventional anesthesia (CA) and fentanyl anesthesia (FA). The FA patients received 134.0 +/- 15.3 microg/kg fentanyl citrate and the CA patients 15.7 +/- 7.4 microg/kg fentanyl during the surgery. Protein turnover was measured by the method of bolus infusion of [15N]glycine (1 g). High dose of fentanyl anesthesia reduced cortisol levels during the surgery (CA 38.0 +/- 13.8 pg/ml vs FA 13.5 +/- 2.4, P < 0.05) and interleukin-6 levels in the plasma after the surgery (P < 0.02). The postoperative nitrogen retention was greater with fentanyl anesthesia than with conventional anesthesia. Both protein synthesis and breakdown rates were increased with fentanyl anesthesia, while they were unaltered in CA patients. Postoperative fibrinogen synthesis rate was greater with FA than with CA (CA 51.1 +/- 9.2%/day vs FA 100.9 +/- 14.0, P < 0.01). The protein turnover and fibrinogen synthesis data suggested a shorter duration of shock phase in FA patients than in CA patients. We concluded that a high dose of fentanyl anesthesia reduced surgical stress levels and shortened the postoperative shock phase, resulting in a nitrogen-sparing effect.

Effect of methionine-deprived total parenteral nutrition on tumor protein turnover in rats

BACKGROUND

Previous studies have shown that a methionine-lacking diet inhibited tumor growth in rats. The aim of this study was to determine how methionine free total parenteral nutrition (MTPN) can result in the inhibition of tumor growth on tumor protein metabolism in rats.

METHODS

On day 0, AH109A rat ascites hepatoma cells were implanted subcutaneously into male Donryu rats (n = 68, body weight, 200-225 gm). On day 10, a catheter for total parenteral nutrition (TPN) was placed and either MTPN or standard TPN solution was given for 5 days. On day 15, 1-14C-leucine was infused continuously to measure tumor protein synthesis. Tumor proteolysis was calculated from tumor regional blood flow, using the 85Sr-microsphere injection method.

RESULTS

1) Tumor weight was reduced with MTPN. 2) MTPN did not affect tumor protein synthesis, probably because endogenous methionine production was increased with MTPN (87.3 +/- 13.5 mumole methionine/kg/hour vs. 218.6 +/- 29.5, P < 0.01); however, MTPN caused an increase of tumor proteolysis (2.68 +/- 0.53 mumole leucine/g/hour vs. 3.79 +/- 0.73, P < 0.05).

CONCLUSION

The enhanced tumor protein breakdown contributed to the inhibition of tumor growth that was found with the rats given the methionine free diet.

Identification of bifidobacteria from dairy products and evaluation of a microplate hybridization method

Sixteen strains of Bifidobacterium isolated from 15 dairy products such as yogurt, cultured milk, butter and cheese were characterized on the basis of phenotypic characteristics and DNA similarities were examined by a microplate hybridization method. Three of the strains were identified as Bifidodobacterium longum, one strain was identified as Bifidobacterium bifidm, and one strain was assigned to the species Bifidobacterium breve on the basis of phenotypic characteristics, and this identification was confirmed by the analysis of DNA similarities. The remaining 11 strains could not be identified by examining their phenotypic characteristics and, contrary to the product label information, these strains were identified as Bifudidobacterium animalis on the basis of DNA similarities. The applicability of the colorimetric hybridization method in micro dilution wells to genetic identification of Bifidobacterium species was also studied.

Effect of administration of bifidobacteria and lactic acid bacteria to newborn calves and piglets

The effect of oral administration of bifidobacteria and lactic acid bacteria on newborn livestock was investigated. Oral administration of Bifidobacterium pseudolongum or Lactobacillus acidophilus to calves improved BW gain and feed conversion over that of untreated controls. The frequency of diarrhea occurrence was decreased in the group fed probiotics. However, there was no significant difference between calves administered B. pseudolongum and those administered L. acidophilus. Under conditions of feeding without antibiotics, the frequency of diarrhea was decreased markedly by administration of probiotics. The BW gain of piglets was significantly greater during both the suckling and weaning periods for the group fed probiotics than for the control group. The effect was more evident during the suckling period than during the weaning period. Under conditions of feeding without antibiotics, the frequency of piglet mortality was decreased markedly by administration of probiotics. The probiotics tested here had useful effects, including improved BW gain, feed conversion, and fecal condition of both newborn calves and piglets.

Effect of glutamine supplementation on protein metabolism and glutathione in tumor-bearing rats

BACKGROUND

Since tumor-bearing rats are deficient in glutamine, we investigated whether (1) glutamine and glutathione deficiency occur in tumor-bearing rats, (2) glutamine supplementation caused an increase of glutathione levels in host tissues and tumor, (3) glutamine enhances protein synthesis in host tissues, and (4) glutamine stimulated the tumor to synthesize protein and DNA.

METHODS

Male Donryu rats were randomized into four groups: (1) non-tumor-bearing rat (NTB) + standard total parenteral nutrition (STPN); (2) NTB + glutamine-supplemented TPN (GTPN); (3) tumor-bearing rat (TB) + STPN; (4) TB + GTPN. On day 0 AH109A rat hepatoma cells were subcutaneously injected into the backs of rats to induce tumor. The animals were maintained on TPN for 6 days from day 10 through day 15. On day 15, 1-14C-leucine was given by a 5-hour continuous infusion (2.0 microCi/h per rat) to determine the fractional synthesis rate and endogenous leucine production. The levels of glutamine and glutathione were measured by HPLC. the tumor DNA synthesis was estimated by bromodeoxyuridine labeling index.

RESULTS

Tumor development led to a significant weight loss, but this weight loss was significantly lessened by glutamine supplementation because of an increase in muscle protein synthesis. Glutamine did not enhance tumor weight, protein, and DNA synthesis in the tumor. Tumor development caused a significant reduction of glutathione in the muscle, jejunum, and liver, but supplemented glutamine increased the levels of glutathione in the jejunum.

CONCLUSION

Glutamine supplementation is beneficial in preventing deficiencies of glutamine and glutathione and in improving protein metabolism in tumor-bearing rats.

Effect of methionine-deprived total parenteral nutrition on tumor protein turnover in rats

BACKGROUND

Previous studies have shown that a methionine-lacking diet inhibited tumor growth in rats. The aim of this study was to determine how methionine free total parenteral nutrition (MTPN) can result in the inhibition of tumor growth on tumor protein metabolism in rats.

METHODS

On day 0, AH109A rat ascites hepatoma cells were implanted subcutaneously into male Donryu rats (n = 68, body weight, 200-225 gm). On day 10, a catheter for total parenteral nutrition (TPN) was placed and either MTPN or standard TPN solution was given for 5 days. On day 15, 1-14C-leucine was infused continuously to measure tumor protein synthesis. Tumor proteolysis was calculated from tumor regional blood flow, using the 85Sr-microsphere injection method.

RESULTS

1) Tumor weight was reduced with MTPN. 2) MTPN did not affect tumor protein synthesis, probably because endogenous methionine production was increased with MTPN (87.3 +/- 13.5 mumole methionine/kg/hour vs. 218.6 +/- 29.5, P < 0.01); however, MTPN caused an increase of tumor proteolysis (2.68 +/- 0.53 mumole leucine/g/hour vs. 3.79 +/- 0.73, P < 0.05).

CONCLUSION

The enhanced tumor protein breakdown contributed to the inhibition of tumor growth that was found with the rats given the methionine free diet.

Effect of glutamine supplement and hepatectomy on DNA and protein synthesis in the remnant liver

One of the physiological roles of glutamine is as a precursor for DNA synthesis. The aims of this study were to determine (1) whether glutamine-supplemented total parenteral nutrition (TPN) enhanced DNA and protein synthesis in the liver and (2) whether glutamine uptake was increased following partial hepatectomy in rats. Male Donryu rats (n = 59; body weight, 250-275 g) were randomized into four groups: (1) sham operation + standard TPN solution (C-STPN); (2) C + glutamine-supplemented TPN (C-GTPN); (3) 70% partial hepatectomy + STPN (H-STPN); (4) partial hepatectomy + GTPN (H-GTPN). On Day 0, rats underwent either a sham operation or 70% partial hepatectomy and concomitantly were catheterized in the jugular vein. TPN was begun immediately after the surgery. GTPN was isocaloric and isonitrogenous with STPN and 25% of total nitrogen was given as glutamine. On Day 2, the animals were sacrificed after either a continuous infusion of 1-14C-leucine or a bolus i.v. injection of bromodeoxyuridine. The rate of hepatic regeneration was enhanced with glutamine supplementation (H-STPN, 60.8 +/- 1.6% vs H-GTPN, 66.3 +/- 2.0, P < 0.05) due to an increase in protein synthesis in the liver (H-STPN, 134.0 +/- 10.3%/day vs H-GTPN, 160.9 +/- 6.9, P < 0.05) and DNA synthesis in hepatocytes (H-STPN, 23.1 +/- 2.5% vs H-GTPN, 31.4 +/- 2.9, P < 0.05). The uptake of glutamine by the liver was increased following hepatectomy with GTPN supplementation.(ABSTRACT TRUNCATED AT 250 WORDS)

Potentiometric butyrylcholine sensor for organophosphate pesticides

A highly sensitive potentiometric butyrylcholine (BuCh) sensor based on plasticized poly(vinyl chloride) membrane was fabricated using tetrakis (3,5-bis[2-methoxy-hexafluoro-methyl] phenyl) borate (HFPB) as a cation exchanger. The sensor showed a Nernstian response from 10(-1) M to 10(-6) M for BuCh. The detection limit of the sensor was 1.8 x 10(-7) M. The potential stability, lifetime and detection limit of the BuCh-sensor were improved in comparison with corresponding parameters of BuCh-sensors using prepared other cation exchangers. This improvement was proved to be due to higher hydrophobicity of the cation exchanger, HFPB. Enzyme activity of butyrylcholinesterase (BuChE) was determined by the BuCh-sensor fabricated. Since the selectivity coefficient of the BuCh-sensor for BuCh against a product of the enzyme reaction, choline, was as low as 6.3 x 10(-3), the sensor was not affected by interference from choline even when the enzyme reaction proceeded up to about 80%. Michaelis parameters for the BuChE reaction were obtained by the sensor. Determinations of organophosphate pesticides, 2,2-dichlorovinyldimethylphosphate and o-(4-bromo-2-chlorophenyl)o-ethyl S-propylphosphothiolate) were conducted by measuring inhibition of enzyme activity. The enzyme reaction rate was related to the concentration of pesticides. Pesticides were successfully determined between micromole and sub-nanomole levels by the BuCh-sensor.