Micrometastatic tumor cells in the bone marrow of patients with non-small cell lung cancer

BACKGROUND

This study was designed to evaluate the incidence and clinical implications of detection of micrometastatic cancer cells in bone marrow aspirates of patients with operable non-small cell lung cancer. The relationship between micrometastatic cells and p53 overexpression in the primary tumor was also assessed.

METHODS

Thirty-nine patients with stages I through III non-small cell lung cancer who underwent curative resection were entered into this study. Immunohistochemistry with monoclonal antibody to cytokeratin 18 was used to detect tumor cells in bone marrow. Immunostaining of p53 protein in the corresponding primary tumors was also done.

RESULTS

Cytokeratin 18-positive cells were detected in 15 (39%) of the 39 patients. Overexpression of p53 was associated with positivity of the tumor cells in the bone marrow at borderline significance (14/29 versus 1/10; p = 0.0574). The patients with cytokeratin 18-positive cells in bone marrow demonstrated a significantly earlier recurrence than those without such cells (p = 0.0083, log-rank test).

CONCLUSIONS

Micrometastatic cancer cells were frequently present in bone marrow of patients with operable non-small cell lung cancer and may be a significant predictor of early recurrence. Further evaluation of this method may be useful in identifying patients with non-small cell lung cancer who are most likely to benefit from adjuvant chemotherapy.

Detection of 14q32.33 translocation and t(11;14) in interphase nuclei of chronic B-cell leukemia/lymphomas by in situ hybridization

Abnormalities of chromosome 14 involving band q32.33 are among the most commonly observed cytogenetic alterations in B-cell malignancies. To assess the incidence and pathogenetic implications of 14q32.33 translocation in chronic B-cell leukemia/lymphomas, we performed fluorescence in situ hybridization (FISH) analysis with variable region (V(H)) and gamma constant region (Cgamma) gene probes in 37 patients with these disorders. Chromosome 14q32.33 translocation was detected in 2 of 18 patients with chronic lymphocytic leukemia (CLL), 1 of 2 with CLL of mixed cell types (CLL/PL), 1 of 2 with pro-lymphocytic leukemia (PLL), 5 of 6 with leukemic mantle-cell lymphoma (MCL), 2 of 7 with splenic B-cell leukemia/lymphoma of possible marginal zone origin (SBLL) and 2 with leukemic follicular lymphoma (FL). To further characterize 14q32.33 translocations in these patients, we developed a new procedure using double-color FISH with PRAD1, BCL2, V(H) and Cgamma gene probes. Chromosome t(11;14) was detected in 1 patient with CLL/PL, 1 with PLL and 5 with MCL. Chromosome t(14;18) was detected in 2 patients with FL. In a PLL patient with t(11;14), the cosmid CPP29 containing the PRAD1 gene and its 5'-flanking region split and co-localized with both Cgamma and V(H) gene probes, thus spanning the breakpoint. In CLL and SBLL patients, donor chromosomes were other than chromosomes 2, 11, 18 and 19, suggesting the involvement of a novel oncogene(s) in the pathogenesis of these diseases. Interphase FISH rapidly detected 14q32.33 translocation, t(11;14) and t(14;18) in B-cell malignancies with low mitotic activity at the single-cell level, facilitating the correlation of the molecular features of these translocations with clinical characteristics.

Role of gastric mucosal constitutive and inducible nitric oxide synthases in the development of stress-induced gastric mucosal lesions in rats

Changes in gastric mucosal constitutive NO synthase (cNOS) and inducible NO synthase (iNOS) activities with the development of gastric mucosal lesions induced by water immersion restraint (WIR) stress were investigated in rats pretreated with and without NOS inhibitors. A decrease in cNOS activity and an increase in iNOS activity in the gastric mucosa occurred with gastric mucosal lesion development. Pretreatment with N(G)-monomethyl L-arginine, a non-selective NOS inhibitor, enhanced gastric mucosal lesion development with inhibition of gastric mucosal cNOS and iNOS activities, although the inhibited iNOS activity was still higher than the normal level. Pretreatment with aminoguanidine, a selective iNOS inhibitor, prevented gastric mucosal lesion development with inhibition of iNOS activity and maintenance of cNOS activity in the gastric mucosa. These results indicate that in WIR-stressed rats, an increase in iNOS activity and a decrease in cNOS activity in the gastric mucosa are closely related to the development of gastric mucosal lesions.

The Ig heavy chain gene is frequently involved in chromosomal translocations in multiple myeloma and plasma cell leukemia as detected by in situ hybridization

Chromosome rearrangement of 14q32.33 has recurrently occurred with variable partner sites, including 11q13.3, 8q24.1, 18q21.3, and 6p21.1 in multiple myeloma (MM). To assess the actual incidence of 14q32.33 translocation and to elucidate its implication in the pathogenesis of MM, we studied 42 patients with MM, plasma cell leukemia, or plasmacytoma and 5 with monoclonal gammopathy with undetermined significance (MGUS) by G-banding and molecular cytogenetic methods. Using double-color fluorescence in situ hybridization (DCFISH) with 2 Ig heavy chain (IgH) gene probes, a yeast artificial chromosome (YAC) clone containing variable region, and a phage clone containing gamma constant region, 14q32.33 translocation was detected as split signals of the IgH gene in 31 patients with plasma cell malignancies and 3 with MGUS. In contrast, of 40 patients who were assessed by G-banding, 3 (7.5%) showed the 14q+ chromosome. DCFISH detected a split of the IgH gene on interphase nuclei in 34 (73.9%) of 46 patients analyzed, whereas on metaphase spreads, it was in 22 (51.2%) of 43 patients analyzed. Interphase DCFISH was particularly useful to detect 14q32.33 translocation in 17 (65.4%) of 26 patients with normal karyotypes. Donor sites were identified in 11 of 22 patients demonstrated as carrying 14q32.33 translocation by metaphase FISH. Chromosome t(11;14)(q13.3; q32.33) was detected in 5 patients, t(8;14)(q24.1;q32.33) in 2, t(14;18)(q32.33;q21.3) in 2, and t(7;14)(q32.1;q32.33) in 1. A complex 14q32.33 translocation involving 3q and 16q24 was detected in 1 patient. Myeloma cells with t(7;14) showed myelomonocytoid surface antigen. Because rearrangements of 14q32.33 were closely associated with translocation of proto-oncogenes into the IgH gene, our findings indicate that 14q32.33 translocation with various partner chromosomes is a critical event in the pathogenesis of MM and MGUS.

Detection of 14q32.33 translocation and t(11;14) in interphase nuclei of chronic B-cell leukemia/lymphomas by in situ hybridization

Abnormalities of chromosome 14 involving band q32.33 are among the most commonly observed cytogenetic alterations in B-cell malignancies. To assess the incidence and pathogenetic implications of 14q32.33 translocation in chronic B-cell leukemia/lymphomas, we performed fluorescence in situ hybridization (FISH) analysis with variable region (V(H)) and gamma constant region (Cgamma) gene probes in 37 patients with these disorders. Chromosome 14q32.33 translocation was detected in 2 of 18 patients with chronic lymphocytic leukemia (CLL), 1 of 2 with CLL of mixed cell types (CLL/PL), 1 of 2 with pro-lymphocytic leukemia (PLL), 5 of 6 with leukemic mantle-cell lymphoma (MCL), 2 of 7 with splenic B-cell leukemia/lymphoma of possible marginal zone origin (SBLL) and 2 with leukemic follicular lymphoma (FL). To further characterize 14q32.33 translocations in these patients, we developed a new procedure using double-color FISH with PRAD1, BCL2, V(H) and Cgamma gene probes. Chromosome t(11;14) was detected in 1 patient with CLL/PL, 1 with PLL and 5 with MCL. Chromosome t(14;18) was detected in 2 patients with FL. In a PLL patient with t(11;14), the cosmid CPP29 containing the PRAD1 gene and its 5'-flanking region split and co-localized with both Cgamma and V(H) gene probes, thus spanning the breakpoint. In CLL and SBLL patients, donor chromosomes were other than chromosomes 2, 11, 18 and 19, suggesting the involvement of a novel oncogene(s) in the pathogenesis of these diseases. Interphase FISH rapidly detected 14q32.33 translocation, t(11;14) and t(14;18) in B-cell malignancies with low mitotic activity at the single-cell level, facilitating the correlation of the molecular features of these translocations with clinical characteristics.

Effectiveness of hyaluronan on corneal epithelial barrier function in dry eye

AIMS/BACKGROUND

The aim of this study was to assess quantitatively the effectiveness of hyaluronan on corneal disruption in patients with dry eye. Corneal epithelial barrier function was evaluated by measuring fluorescein permeability using a slit-lamp fluorophotometer.

METHODS

11 patients with dry eye were assigned to this study. Hyaluronan ophthalmic solution (0.1% hyaluronic acid) was instilled five times a day to the right eye, in addition to the usual artificial tear solutions. The left eye received only the artificial tear solutions. Corneal barrier function was evaluated on the pretreatment day, and at 2 and 4 weeks after treatment. Fluorophotometry was used to measure fluorescein uptake at the central and lower corneal portions.

RESULTS

Two weeks after treatment, hyaluronan treated right corneas showed significant corneal epithelial barrier improvement in the lower portion, compared with the pretreatment day (p < 0.025). Four weeks after treatment, the treated corneas showed significant improvement in the central corneal portion (p < 0.025) and improvement in the lower portion, compared with the pretreatment day. The untreated left corneas, on the other hand showed no improvement during the course of the study.

CONCLUSION

This study suggests that hyaluronan is effective in the treatment of corneal epithelial disruption in dry eye.

Relationship between changes of active oxygen metabolism and blood flow and formation, progression, and recovery of lesions is gastric mucosa of rats with a single treatment of compound 48/80, a mast cell degranulator

The relationship between the changes of active oxygen metabolism and blood flow and the formation, progression, and recovery of lesions was examined in the gastric mucosa of rats treated once with compound 48/80, a mast cell degranulator. Gastric mucosal lesions appeared 0.5 hr after compound 48/80 treatment, became worst at 3 hr, and recovered fairly well at 12 hr. Increases in gastric mucosal lipid peroxide content and xanthine oxidase and myeloperoxidase activities and decreases in gastric mucosal vitamin E and hexosamine contents and Se-dependent glutathione peroxidase activity occurred with the formation and progression of gastric mucosal lesions. These changes were attenuated with the recovery of the lesion. Gastric mucosal nonprotein SH content decreased with the formation of gastric mucosal lesions, and this decreased SH content returned to near the original level with lesion progression. No changes in gastric mucosal superoxide dismutase and catalase activities occurred with the formation, progression, and recovery of gastric mucosal lesions. Gastric mucosal blood flow decreased with the formation of gastric mucosal lesions, and this decreased blood flow recovered with lesion progression. Serum serotonin concentration, an index of mast cell degranulation, increased with the formation of gastric mucosal lesions, and this increased serotonin level was attenuated with lesion progression and recovery. Pretreatment with ketotifen, a connective tissue mast cell stabilizer, prevented the formation of gastric mucosal lesions, the increases of gastric mucosal lipid peroxide content, xanthine oxidase and myeloperoxidase activities, and serum serotonin level; and the decreases of gastric mucosal nonprotein SH content, glutathione peroxidase activity, and blood flow found at 0.5 hr after compound 48/80 treatment. These results indicate that the changes of gastric mucosal active oxygen metabolism and blood flow are closely related to the formation, progression, and recovery of gastric mucosal lesions in rats with a single compound 48/80 treatment. The present results also suggest that this compound 48/80-induced gastric mucosal injury could be a kind of ischemia-reperfusion-induced injury occurring through degranulation of connective tissue mast cells.

Electrophoretic patterns of urinary proteins of diabetics in the pre, early and overt nephropathy stages

Urinary proteins of patients with diabetes mellitus (DM) were analyzed using cellulose acetate membrane electrophoresis, to determine the clinical usefulness of fraction patterns of the proteins in detecting the group at high risk for diabetic nephropathy. We divided the protein patterns into 5 groups. Four groups (I, II, III, IV) were found in the healthy group and a newly classified group was termed group 0 and was characterized by a prominent albumin peak with a negligible or small globulin peak. The incidence of groups 0, I, II, III, and IV, was 36.6%, 13.3%, 18.7%, 10.7% and 22.7%, respectively. This distribution was clearly different from that of healthy subjects and the most characteristic feature of diabetics was that group 0 accounted for 36.6% of the total cases. Characteristic features of each group were examined from the aspect of laboratory and clinical findings. Urinary protein patterns were concluded to be useful not only to predict the high risk group for diabetic nephropathy in the preclinical stage but also to discriminate nephropathic types of glomerular or tubular origin. It is useful for clinicians to know the risk stage and prognosis for diabetic nephropathy.

Percutaneous release for trigger finger in idiopathic and hemodialysis patients

Sixty-seven trigger fingers of 58 idiopathic and hemodialysis patients were treated by percutaneous A1-pulley release technique. Severity of triggering was classified into five grades for treatment selection and prediction of possible results. Results were excellent in 41 fingers, good in 9, fair in 7, and poor in 10, requiring additional treatment. The results of the lower grades were better, and those of the higher grades were poor. Excellent or good results appeared to depend on the proper selection of the patients according to the grading system and confirmation of triggering disappearance just after the release. There were neither infections nor neuro-vascular deficits after treatment. Compared to conventional open release, this treatment was found to be more useful from the standpoints of ease and safety of the technique, and the patients' quick return to normal life.

[Use of hemostatic clips for endoscopic hemostasis and closure of an esophageal laceration caused by a fish bone]

An 82-year-old woman was admitted to our hospital because of hematemesis. She had had a feeling of a foreign substance in her throat for one week after having eaten fish. On admission she had a fever of 38 degrees C, Hb of 5.8 g/dl, CRP level of 8.8 mg/dl, and bilateral pleural effusions. Endoscopy revealed a deep longitudinal laceration with active bleeding in the esophagus that also caused mediastinitis. Endoscopic hemostasis and closure of the laceration was done with hemostatic clips. The esophageal injury seemed to have been caused by a fish bone. After the treatments described here were carried out, the patient's condition rapidly improved.

[An elderly case of post-bulbar Dieulafoy's ulcer]

The case is a 79-year-old man who came to our hospital with melena as chief complaint. Emergency endoscopy showed spurting bleeding from a small ulcer. We diagnosed as Post-Bulbar Dieulafoy's ulcer and performed hemostatic procedure with hemostatic clips. The forth endoscopy (7 days after admission) showed fresh clot and oozing bleeding after the third hemostatic clipping. Although we performed hemostatic procedure with the injection therapy of hypertonic saline epinephrine solution (HSE). The effective hemostatic procedure is discussed with reference to some related literature.

[Development of beta-lactamase inhibitors]

The proportion of beta-lactamase producing bacteria in each species of clinical isolates is high (over 90%) in these years. According to the survey of bacterial resistance in 1995, higher proportion of resistant bacterial species against ampicillin, piperacillin (PIPC), cefazolin, cefotiam was observed. To overcome the bacterial resistance against these beta-lactam antibiotics, we have made a development of beta-lactamase inhibitor and its combination antibiotic. New beta-lactamase inhibitor, tazobactam (TAZ) showed strong inhibitory activity against various kinds of beta-lactamases including cephalosporinases. The combination antibiotic, TAZ/PIPC(TAZ combined with PIPC by 1 to 4) showed stronger antibacterial activity than PIPC against beta-lactamase producing stains. And also the activity of TAZ/PIPC was superior to PIPC in the mixed bacterial infection model in mouse. The in vitro and in vivo frequency of emergence of resistant bacteria from Enterobacteriacae treated with TAZ/PIPC was lower than that of PIPC or ceftazidime (CAZ). By these data, combined antibiotics with beta-lactamase inhibitor was effective to resolve the problems of bacterial resistances caused by beta-lactamases.

Superior effect of tazobactam/piperacillin compared to piperacillin on beta-lactamase-producing Pseudomonas aeruginosa

To evaluate the synergistic antimicrobial effects of tazobactam (TAZ), a beta-lactamase inhibitor, and piperacillin (PIPC) on Pseudomonas aeruginosa, we compared the antimicrobial effects of TAZ/PIPC with those of PIPC alone on bacteria inducibly or constitutively producing beta-lactamase. TAZ/PIPC had more potent antimicrobial effects compared with PIPC on clinical isolates producing beta-lactamase. In the treatment of mouse systemic infection, the therapeutic effect of PIPC was markedly decreased by beta-lactamase, but that of TAZ/PIPC was only slightly decreased. In the treatment of local infections in mice, the therapeutic effects of PIPC were decreased due to the induction of beta-lactamase and the emergence of bacterial strains constitutively producing beta-lactamase, while those of TAZ/ PIPC were not affected.

Pentoxifylline decreases brain levels of platelet activating factor in murine AIDS

Tumor necrosis factor-alpha (TNF-alpha) and platelet-activating factor (PAF) have been implicated in the pathogenesis of human immunodeficiency virus (HIV)-associated encephalopathy. The effects of pentoxifylline on brain PAF levels were examined in mice infected with the LP-BM5 murine leukemia virus (MuLV). Seven weeks after viral inoculation, significant increases in serum TNF-alpha and brain PAF levels were observed. One week of treatment with pentoxifylline initiated 6 weeks postinfection significantly reduced both serum TNF-alpha and brain PAF levels. A significant positive correlation was observed between the levels of these substances (r = 0.62; P < 0.01). This study demonstrates that pentoxifylline treatment was effective in decreasing the levels of TNF-alpha in the serum and PAF levels in the brain of mice infected with the LP-BM5 MuLV.

Histopathology and clinical results of carpal tunnel syndrome in idiopathic cases and hemodialysis patients

The results of the histological examinations of specimens of the tenosynovium of the flexor tendon, the epineurium and the transverse carpal ligament from two groups of Japanese patients with carpal tunnel syndrome (idiopathic and hemodialysis) were compared. Amyloid deposits, positively identified as beta 2-microglobulin, appeared in all patients in the long-term hemodialysis group, but in no patients in the idiopathic group. Although the pathogenesis differed between the two groups, both resulted in nerve compression in the carpal tunnel. Therefore, surgical release is considered beneficial for both groups.

Rapid detection of lymphoma-specific translocations in interphase nuclei of non-Hodgkin's lymphoma by fluorescence in situ hybridization

We have recently developed a method to detect tumor-specific rearrangement of the IgH gene in interphase nuclei by fluorescence in situ hybridization. Tumor-specific IgH gene rearrangement is equivalent to 14q32.33 translocation. Using this approach, we detected 14q32.33 translocation in 29 of 70 patients with B-cell non-Hodgkin's lymphoma (NHL). Chromosome t(3;14) was found in 10 of these 29 patients, and were demonstrated as a fusion signal of BCL6 and VH gene probes in interphase nuclei. Furthermore, in another series of 11 patients and a NHL cell line, we demonstrated t(14;18) and t(11;14) in interphase and metaphase cells with a combination of BCL2 (or PRAD1) with IgH gene probes. Interphase FISH with lymphoma-associated gene probes is a rapid procedure for cytogenetic diagnosis of B-cell NHL.

Urinary procoagulant activity and tissue factor levels in patients with diabetes mellitus

We characterized a factor important for the normal procoagulant activity in human urine and measured urinary tissue factor (TF) and thrombomodulin (TM) levels in patients with diabetes mellitus (DM). Urine shortened normal plasma-based clotting time, which is inhibited by antibody to the human TF. TF in urine presents in membrane-nonassociated and associated forms. The urine TF antigen levels in DM patients were significantly lower than those in healthy subjects, particularly in DM patients without retinopathy. Levels of TM in patients with DM and normal subjects were similar. Although urinary TF might be necessary to repair tissue injury of damaged sites in the excretory pathway of urine, the clinical relevance of the reduced TF in the urine needs further investigation.

In vitro effects of a recombinant toxin, mSCF-PE40, targeting c-kit receptors ectopically expressed in small cell lung cancers

Most small cell lung cancers (SCLCs) ectopically express high levels of the c-kit receptor. We have examined if the receptor can serve as a target for a chimeric toxin, mSCF-PE40 composed of murine stem cell factor (SCF) genetically fused to the N terminus of a modified form of Pseudomonas exotoxin (PE) lacking its cell recognition domain. Selective cytotoxicity was found for human c-kit receptor-negative cells. This agent thus warrants further evaluation for therapy of human CSLCs.

Attenuation of disrupted hepatic active oxygen metabolism with the recovery of acute liver injury in rats intoxicated with carbon tetrachloride

In this study, we examined how disrupted hepatic active oxygen metabolism at a progressed stage of carbon tetrachloride (CCl4)-induced acute liver injury is attenuated with the recovery of the injury in fed rats. When the progression and recovery of liver injury were assessed by measuring the activities of serum transaminases, indexes of liver cell damage, at 2, 24, 48, and 72 h after a single intraperitoneal injection of CCl4 (1.0 ml/kg body weight), an apparent liver injury was found at 2 h, the most progressed liver injury occurred at 24 h, and the progressed liver injury fairly recovered at 72 h. Hepatic superoxide dismutase and catalase activities decreased with the progression of liver injury but both decreases were maintained during the recovery of the injury. Hepatic glutathione peroxidase activity did not change with the progression and recovery of liver injury. Hepatic glutathione reductase activity decreased with the progression of liver injury and the decreased activity was returned up to the original level with the recovery of the injury. Hepatic glucose-6-phosphate dehydrogenase activity increased with the progression and recovery of liver injury but this increased activity was reduced at a late stage of the recovery. Hepatic reduced glutathione and ascorbic acid contents decreased with the progression of liver injury but both decreased contents were returned up to the original levels with the recovery of the injury. Hepatic vitamin E content decreased at an early stage of liver injury but this decreased vitamin E content increased over the original level with the progression of the injury and this increased vitamin E content was maintained during the recovery of the injury. Hepatic lipid peroxide content increased with the progression of liver injury and this increased content was returned near the original level with the recovery of the injury. These results indicate that in rats intoxicated once with CCl4, disrupted hepatic active oxygen metabolism at a progressed stage of liver injury is attenuated with the recovery of the injury mainly through the improvement of hepatic active oxygen metabolism mediated by the glutathione redox cycle and ascorbic acid.

Ocular membrane permeability of hydrophilic drugs for ocular peptide delivery

The purpose of this study is to investigate the ocular membrane permeability and the permeation mechanism of hydrophilic drugs such as thyrotropin-releasing hormone (TRH), p-nitrophenyl beta-cellopentaoside (PNP) and luteinizing hormone-releasing hormone (LHRH). The penetration of hydrophilic drugs was measured across the isolated corneal and conjunctival membranes of albino rabbits using a two-chamber diffusion glass cell. The corneal permeabilities of hydrophilic drugs were much lower than those of beta blockers reported previously. The corneal penetration of TRH was the highest among the hydrophilic drugs studied. Scraping the corneal epithelium increased the penetration of hydrophilic drugs. Conjunctival membranes showed higher permeability to hydrophilic drugs compared with corneal membranes. The permeability of drugs was also analysed by Fick's equation. The partition parameter and diffusion parameter of TRH, PNP and LHRH in the cornea were lower than those in scraped cornea and conjunctiva. In addition to the data of fluorescein isothiocyanate-dextran reported previously, the permeability coefficient of hydrophilic drugs through the cornea, scraped cornea and conjunctiva correlated with molecular weight of the drugs. The diffusion parameters of hydrophilic drugs decreased with an increase of molecular weight for all ocular membranes. The extent of dependency of partition parameters on the molecular weights of drugs varied according to the ocular membrane. These results indicate that ocular membranes are sufficiently different in permeation character and mechanism to control the extent and pathway for ocular absorption of hydrophilic drugs.

In-situ ocular absorption of ophthalmic beta-blockers through ocular membranes in albino rabbits

Ocular membranes have been characterized by in-situ absorption of the ophthalmic beta-blockers carteolol (hydrophilic) and timolol and befunolol (lipophilic) using a cylindrical cell. After introduction of drug solution into the cell on the cornea, sclera (bulbar conjunctival and scleral layer) or palpebral conjunctiva, the disappearance of the drug from the cell was determined as in-situ absorption. The ophthalmic drugs disappeared from the conjunctival and scleral membranes although disappearance from the cornea was hardly observed. The conjunctival membrane showed the highest permeability. Lipophilic drugs were more permeable than hydrophilic. In-situ apparent permeability coefficients of the ophthalmic drugs through the conjunctiva and sclera correlated with the lipophilicity of drugs. A high drug concentration in the aqueous humor was observed after corneal application. There is a relationship between concentration in the aqueous humor was observed after corneal application. There is a relationship between concentrations of drugs in the aqueous humor and previously reported in-vitro apparent permeability coefficients of the drugs in the cornea. This in-situ method using a cylindrical cell is a useful method of investigating the ocular absorption of ophthalmic drugs.

Urinary nitrite/nitrate excretion in infancy: comparison between term and preterm infants

We measured urinary nitrite/nitrate (NOx-) excretion, an index of endogenous nitric oxide formation, in term and preterm infants aged 1 week and 1, 4, 7 months. In normal term infants, urinary NOx excretion increased from 1 week to 1 month and then decreased until 4 months where it stabilized thereafter. Urinary NOx- excretion in preterm infants was significantly higher compared with term infants at 1 week of age. This finding suggests that the nitric oxide pathway in preterm infants may be activated compared with term infants in early life. With the reference values obtained in this study, this urinary marker can now be used for identifying infants with abnormal nitric oxide production.

Modulating role of endogenous reduced glutathione in tert-butyl hydroperoxide-induced cell injury in isolated rat hepatocytes

The role of endogenous reduced glutathione (GSH) in tert-butyl hydroperoxide (TBHP)-induced cell injury was examined in isolated rat hepatocytes. When liver cell injury was estimated from release of transaminases from hepatocytes into the incubation medium, cell injury in hepatocytes (2 x 10(6) cells/ml) incubated in Hanks' balanced salt solution (pH 7.2) containing 1.0 mM TBHP at 37 degrees C was potentiated with enhanced lipid peroxidation by prior depletion of intracellular GSH which was induced by diethylmaleate, a GSH depletor. GSH-depleted hepatocytes were incubated with gamma-glutamylcysteinylethyl ester (gamma-ECOEt), which is known to be converted to GSH via glutathione synthetase after its hydrolysis by esterase, at concentrations of 1.0 to 10 mM in order to replenish intracellular GSH. Although TBHP-induced cell injury and lipid peroxidation were enhanced in GSH-depleted hepatocytes, these enhancements were prevented with the consumption of intracellular GSH in GSH-depleted hepatocytes pretreated with 5.0 mM gamma-ECOEt. These preventive effects were observed at any time point during the TBHP treatment over a 60 min period and depended on the concentration of gamma-ECOEt used. But, no preventive effect was found in GSH-depleted hepatocytes pretreated with 5.0 mM GSH. No prevention of the potentiation of TBHP-induced cell injury found in GSH-depleted hepatocytes occurred in GSH-depleted hepatocytes pretreated with both 5.0 mM gamma-ECOEt and 250 microM bis-(p-nitrophenyl)phosphate, a nonspecific esterase inhibitor. gamma-ECOEt treatment caused an increase in intracellular GSH content in GSH-depleted hepatocytes, while treatments of both gamma-ECOEt and the esterase inhibitor caused no increase in intracellular GSH content in the cells. These results indicate that endogenous GSH modulates TBHP-induced cell injury and lipid peroxidation in isolated rat hepatocytes. The present results suggest that endogenous GSH should play a critical role in TBHP-induced cell injury in isolated rat hepatocytes and that in rat hepatocytes treated with TBHP, enhanced lipid peroxidation with the consumption of intracellular GSH could be associated with the initiation of cell injury.