CT angiography with helical CT in the assessment of acute stage of subarachnoid hemorrhage

PURPOSE

We evaluated the usefulness of helical CT in the preoperative assessment of ruptured cerebral aneurysms during the acute stage of subarachnoid hemorrhage (SAH).

METHODS

Nine patients with 13 aneurysms were included in this study. Helical CT scanning was performed before preoperative angiography. The section thickness and the table-movement speed were 1-2 mm/sec. Helical CT scanning was started 20 sec after the start of injection of 100 ml of contrast agent at a rate of 3 ml/sec.

RESULTS

The average CT value of SAH was 51.9 Hounsfield units (HU) and that of the aneurysm was 191.7 HU. Nine of 13 aneurysms greater than 3.0 mm in diameter were identified by three-dimensional CT angiography (3DCTA). In seven cases, the information provided by 3DCTA images, maximum intensity projection images, and multiplanar images, was very useful in surgical planning, providing information concerning the configuration of the neck and relationships between the aneurysm and brain parenchyma. Four aneurysms in two cases were not depicted by 3DCTA because they were located outside the imaging volume. This problem was overcome by changing the imaging volume according to the extent of origin of SAH.

CONCLUSION

We conclude that helical CT in patients with SAH is useful for surgical planning, providing valuable information that cannot be obtained by conventional angiography.

The levels of integrin alpha v beta 5 may predict the susceptibility to adenovirus-mediated gene transfer in human lung cancer cells

Adenovirus mediated transfer of growth-inhibiting molecules, such as p53 shows promise as an effective method of suppressing the growth of cancer cells. As the basis for in vivo studies, we examined transfection efficiency using 15 human lung cancer cell lines that differ in their endogenous p53 status. When infected with an adenovirus expressing bacterial beta-galactosidase, the different cell lines showed different levels of beta-galactosidase activity. We found a correlation between the level of integrin alpha v beta 5, which is thought to be an adherence receptor for adenoviruses, and the expression level of the transferred gene, suggesting that gene expression is largely dependent on the infection efficiency. Growth inhibition was induced in all cell lines tested following infection with an adenovirus containing p53, regardless of the genetic status of their endogenous p53 provided a sufficient amount of p53 protein was expressed. Our results (1) confirm that the examination of the susceptibility of target cancer cells to an adenovirus is important when considering performing adenovirus-mediated gene transfer and for evaluating its therapeutic effects; and (2) suggest that the quantification of integrin alpha v beta 5 may be a good way of predicting the susceptibility of cells to adenoviral vectors.

Effect of fractal dimension on drug permeation through porous ethylcellulose films

Fractal geometry was applied to quantify the complexity of an internal structure of a porous film prepared with ethylcellulose (EC) and diethylphthalate (DEP) as a plasticizer. EC was dissolved together with DEP in a water-ethanol mixture solution, and then evaporated on Teflon petri dishes in order to make porous EC films. Boundary lines of the porous structures in the EC film cross section were taken by a confocal laser microscope as image data, and these images were fed into a computer to estimate the fractal dimension. The porous structure in EC film was observed to be a typical fractal and its complexity was quantified as a non-integral fractal dimension. No clear correlation was observed between the fractal dimension and the porosity of EC films, suggesting that they were mutually independent parameters representing the porous structure in the EC films. The permeation of theophylline through the EC films was determined by using two-chamber diffusion cells. A fairly good relationship between the permeability coefficient of theophylline and the fractal dimensions was observed, suggesting the usefulness of the fractal dimension as a novel parameter for evaluating drug permeation through porous films.

Acute traumatic subdural hematoma originating from a convexity meningioma--case report

A 68-year-old male presented with a traumatic subdural hematoma originating from a convexity meningioma the day after a motorcycle accident. Computed tomography disclosed a right temporal subdural and/or epidural mass. Emergent craniotomy revealed a convexity meningioma with thin subdural hematoma. The underlying brain was apparently healthy. The histological diagnosis was angiomatous meningioma with hemorrhagic foci. The operative and histological findings indicated that the tumoral tissue was the source of the subdural hematoma.

Extracellular signal molecule(s) involved in the carbon starvation response of marine Vibrio sp. strain S14

The role of exogenous metabolites as putative signal molecules mediating and/or regulating the carbon starvation adaptation program in Vibrio sp. strain S14 was investigated. Addition of the stationary-phase supernatant extract (SSE) of Vibrio sp. strain S14 to logarithmic-phase cells resulted in a significant number of carbon starvation-induced proteins being up-regulated. Halogenated furanones, putative antagonists of acylated homoserine lactones (AHLs), inhibited the synthesis of proteins specifically induced upon carbon starvation. The effect of the furanone was the opposite of that caused by SSE with respect to the up- and down-regulation of protein expression, indicating that both the furanone and the putative signalling molecules were acting on the same regulatory pathway. Culturability was rapidly lost when Vibrio sp. strain S14 was starved in the presence of the furanone at a low concentration. The furanone also had a negative effect on the ability of carbon-starved cells to mount resistance against UV irradiation and hydrogen peroxide exposure. The SSE of Vibrio sp. strain S14 had the ability to provide cross-protection against the loss in viability caused by the furanone. We have further demonstrated that the SSE taken from low- as well as high-cell-density cultures of Vibrio sp. strain S14 induced luminescence in Vibrio harveyi. Taken together, the results in this report provide evidence that Vibrio sp. strain S14 produces extracellular signalling metabolites during carbon and energy starvation and that these molecules play an important role in the expression of proteins crucial to the development of starvation- and stress-resistant phenotypes.

Application of the polymerase chain reaction for the diagnosis of malignant lymphoma of the nasal and oral cavities

Difficulties are often encountered in the diagnosis of malignant lymphoma of the oral and nasal cavities by histology and immunohistochemistry because these malignancies may be complicated by inflammation and necrosis. In the present study, immunoglobulin heavy chain (IgH) and T-cell receptor (TCR) gene rearrangements were examined by the polymerase chain reaction (PCR) in formalin-fixed and paraffin-embedded specimens obtained from 18 patients; the advantages of this method were evaluated. Twelve of these patients were diagnosed as having malignant lymphoma and six had tumors highly suggestive of malignant lymphoma. Fourteen (78%) of the 18 cases were diagnosed as malignant lymphoma histologically and immunohistochemically. Sixteen (89%) of the 18 cases were shown to be monoclonal by PCR. The four cases that could not be histologically or immunohistochemically diagnosed as malignant lymphoma showed monoclonal gene rearrangement by PCR. As a result, six patients suspected of having a malignant lymphoma were diagnosed as having one. The diagnosis of malignant lymphoma by PCR alone still has various problems. However, when the results of PCR are evaluated together with histopathological and immunohistochemical results, PCR makes a useful contribution to the diagnosis of malignant lymphomas of the nasal and oral cavities.

NACP, a presynaptic protein, immunoreactivity in Lewy bodies in Parkinson's disease

NACP, originally identified as a precursor of the non-Abeta component of Alzheimer's disease amyloid (NAC), is now known to be identical to alpha-synuclein, a presynaptic protein in the human brain. Recently, a mutation in the alpha-synuclein gene in families with autosomal dominant Parkinson's disease (PD) was identified. We carried out immunohistochemical examinations of the brains of sporadic PD patients using anti-NACP and anti-ubiquitin antibodies. Consistent with previous studies, the anti-NACP antibody immunostained the neuropil in a punctate pattern throughout the brain. Moreover, much stronger NACP immunoreactivity was found in Lewy bodies and degenerating neurites in the brainstem. Serial sections immunolabeled with anti-ubiquitin or anti-NACP showed that all ubiquitin-immunoreactive LBs were also NACP-immunoreactive. These findings suggest that alteration of NACP metabolism is involved in the pathogenesis of PD, particularly in Lewy body formation, leading to neurodegeneration.

A new technology for revascularization of cerebral embolism using liquid jet impact

Revascularization time is the dominant factor in the treatment of acute cerebral embolism. In this paper we describe a rapid revascularization therapy using liquid jets generated by the interaction of gas bubbles with shock waves, which impact on the thrombi. The interaction of a shock wave with a gas bubble attached to an artificial thrombus which was inserted into a tube model of a cerebral artery was investigated. The shock wave was generated by detonating a microexplosive pellet. The overpressure of the shock wave was 3.0 +/- 0.6 MPa (n = 7) and 12.7 +/- 0.4 MPa (n = 3). The initial air bubble radii were varied from 0.87 mm to 2.18 mm. The subsequent collapse of the bubble was photographed using a high-speed framing camera, and the liquid jet penetrating into the artificial thrombus was visualized using x-ray photography. The penetration depth of the liquid jet increased with increasing bubble size. There was an optimal separation distance between the bubble and the shock wave source to obtain the maximum penetration depth. Liquid jets have the potential to penetrate through thrombi in as little as a few microseconds, and with very efficient ablation.

Interleukin-8 participates in angiogenesis in non-small cell, but not small cell carcinoma of the lung

We examined interleukin-8 (IL-8) production in 17 lung cancer cell lines, IL-8 expression in tumor specimens and IL-8's contribution to tumor-induced angiogenesis in vivo. Eight of 13 non-small cell lung cancer cell lines constitutively produced high levels of IL-8. Four small cell lung cancer cell lines produced little or no IL-8. Immunohistochemical analysis of transbronchial biopsy specimens revealed IL-8 staining within adenocarcinomas (22/32), squamous cell carcinomas (12/21) and large cell carcinomas (2/3), but not within most small cell carcinomas (1/22). Anti-IL-8 antisera blocked tumor angiogenesis by two IL-8 producing cell lines in a mouse model.

Pharmacokinetic and pharmacological profiles of free and liposomal recombinant human erythropoietin after intravenous and subcutaneous administrations in rats

PURPOSE

Recombinant human erythropoietin (Epo) is used frequently through intravenous (i.v.) and subcutaneous (s.c.) administration for the clinical treatment of the last stage of renal anemia. We encapsulated Epo in liposomes to develop an alternative administration route. The purpose of our study was to evaluate the pharmacokinetics and the pharmacological effects of liposomal Epo in comparison with the Epo after i.v. and s.c. administration to rats.

METHODS

Epo was encapsulated in liposomes composed of dipalmitoylphosphatidylcholine (DPPC) and soybean-derived sterol mixture (SS) prepared by the reversed-phase evaporation vesicle method. After filtration through a 0.1 micron polycarbonate membrane, liposomes were gel filtered (Epo/liposomes).

RESULTS

Epo/liposomes showed higher pharmacological activity than Epo/liposomes before gel filtration after i.v. administration to rats. Non-encapsulated Epo lost its activity, whereas encapsulated Epo in liposomes retained it. The pharmacological effects of Epo/liposomes were greater than those of Epo after i.v. administration. Epo/liposomes afforded 3-9 times higher AUC, lower clearance and lower steady-state volume of distribution than Epo after both i.v. and s.c. administrations. Epo/liposomes had an improved pharmacokinetics profile compared with Epo. S.c. administration of Epo/liposomes at 7 h may penetrate primarily (40% of dose) through the blood as a liposome and partly (7% of dose) in lymph. CONCLUSIONS. Epo/liposomes may reduce the frequency of injections required for a certain reticulocyte effect in comparison to Epo. The lower clearance of Epo/liposomes may increase the plasma concentrations of Epo, which increases the efficacy.

Molecular analysis of ERCC2 mutations in the repair deficient hamster mutants UVL-1 and V-H1

The cDNA sequence of the Chinese hamster ERCC2 nucleotide excision repair and transcription gene from the UVL-1 Chinese hamster ovary (CHO) mutant cell line and the V-H1 Chinese hamster V79 mutant line was analyzed. ERCC2 encodes a presumed ATP-dependent DNA helicase and is single copy in CHO lines due to the structural hemizygosity of chromosome 9. Both UVL-1 and V-H1 have intermediate levels of (6-4) photoproduct repair but are as highly UV sensitive as the group 2 mutants that have no detectable repair. Deficiency in cyclobutane dimer removal has also been shown for V-H1. In UVL-1, a single base substitution resulting in an Arg75-->Trp substitution in helicase domain Ia was identified. The equivalent amino acid position is also Arg in the human, mouse, Xiphophorus maculatus, Saccharomyces cerevisiae, and Schizosaccharomyces pombe homologs. In V-H1, a single base substitution resulting in a Thr46-->Ile substitution in helicase domain I (the ATP-binding domain) was identified in both alleles. The equivalent amino acid position is also Thr in the five homologs. Analysis of three V-H1 partial revertants revealed that they still have the original V-H1 mutation in both alleles, indicating that these are second site reversion events. Site-specific mutagenesis was used to introduce the Thr46-->Ile, Arg75-->Trp, and Lys48-->Arg (helicase domain I) mutations into a hamster ERCC2 expression plasmid. These plasmids each failed to confer UV resistance to group 2 mutant cells, further demonstrating that the changes identified are the causative mutations in V-H1 and UVL-1. Correlations between specific mutations, biochemical activities, and repair phenotype are discussed.

Allergic granulomatous angitis (Churg-Strauss syndrome) with multiple intestinal fistulas

A 40-yr-old man who had a known diagnosis of allergic granulomatous angitis (Churg-Strauss syndrome) and had been on steroids was found to have a stone in the common bile duct. At surgery, multiple internal fistulas were found in the small bowel. Cholecystectomy, removal of the stone in the common bile duct, and resection of the small bowel because of fistulas were performed. To our knowledge, the formation of an intestinal fistula has not been reported as a clinical manifestation of allergic granulomatous angitis. This rare condition occurs in the terminal stage of this disease.

[Paraneoplastic syndrome]

Treatment for the paraneoplastic syndrome associated with lung cancer was reviewed. The principle of the treatment of paraneoplastic syndrome is to control cancer as an underlying disease. Therefore, the standard therapy for Cushing's syndrome associated with lung cancer is surgical treatment if the tumor is operable. There is no standard therapy for Cushing's syndrome associated with advanced small-cell lung cancer. Metyrapone is used in combination with systemic chemotherapy. The effects of ketoconazole and octreotide are under investigation. To control hyponatremia due to the syndrome of inappropriate antidiuretic hormone secretion, fluid restriction is standard. When hyponatremia cannot be controlled with fluid restriction, demeclocycline can be used. For life-threatening hyponatremia, hypertonic saline with intravenous furosemide is administered under careful monitoring. Followed by hydration with saline, pamidronate is effective for the control of symptomatic hypercalcemia. Combined use of calcitonin facilitates rapid normalization of serum calcium for critically ill cases. Heparin is used for patients with recurrent episodes of thrombosis resulting from chronic disseminated intravascular coagulation, although the efficacy is controversial. Thrombocytes and coagulation factors are combined with heparin for patients with uncontrollable bleeding, although the efficacy is not established.

[Sustained release double-layered progesterone suppository for luteal support therapy]

A sustained release suppository containing progesterone with a double-layered structure was prepared for the treatment of the luteal phase defect. Hydroxypropylcellulose-H (HPC) and Carbopol-934P (CP) were used as bases of the inner layer and Witepsol W35 was used as a base of the outer layer. The strength of the inner layer (stick) decreased with the increase of the rate of content of HPC component. The strength of the stick which was prepared from a mixture of HPC and CP in a ratio of 1:1, was inverse by proportional to the rate of the addition of crystalline cellulose (CC) and the amount of released drug was proportional to the rate of the addition of CC. The area under the drug release curve of the stick containing 60% of CC in the base was about 12 times of the stick containing no CC (control stick). Furthermore, the mean release time of the stick containing 60% of CC became about a half of the control stick. It was suggested that the drug release of progesterone from the stick could be controlled by changing the rate of the addition of CC. Two types of suppository which containing progesterone in both phases (suppository A) and in the stick alone (suppository B) were prepared. Both suppositories showed a sustained release property and suppository B had a lag time of two hours. When the suppositories were administered in to the vagina of rabbits, they showed a sustained release property and a rapid rise in the serum concentration was more suppressed than an ordinary Witepsol suppository. One hour after the administration of the two layered suppository, some parts of the suppository was identified macroscopically to be remained in the vagina. The usefulness of the double-layered suppository as a hospital preparation should be suggested after the attainment of the optimization of the formulation.

Phase II trial of dose intensification with cisplatin and carboplatin plus vindesine in patients with inoperable non-small cell lung cancer

We conducted a phase II trial of a regimen that combined cisplatin (CDDP), carboplatin (CBDCA), and vindesine (VDS) in previously untreated patients with non-small cell lung cancer (NSCLC) to evaluate the efficacy and safety of the regimen. Thirty-five patients with inoperable NSCLC entered the study. Cisplatin (CDDP 80 mg/m2) was administered on day 1, and CBDCA 100 mg/m2 and VDS 2 mg/m2) were administered on days 2, 3, and 8. We observed one complete response (CR) and 16 partial responses (PR), with a total response rate of 49% [95% confidence interval (CI) 31-66%]. The overall median survival was 58 weeks; the 1-year survival rate was 60%, and the 2-year survival rate was 23%. Major toxicities were hematologic; leukopenia of grades 3 and 4 occurred in 66% patients, and thrombocytopenia occurred in 23%. Therefore, the dose-intensified regimen of CDDP, CBDCA, and VDS was active in treating patients with inoperable NSCLC, with demonstration of a favorable median survival time.

Formulation of liposomes with a soybean-derived sterylglucoside mixture and cholesterol for liver targeting

In this study, we investigated a liposomal formulation of dipalmitoylphosphatidylcholine (DPPC) with a soybean-derived sterylglucoside mixture (SG) and cholesterol (Ch) for targeting the liver in mice. We found two distribution profiles of liposomes (reverse-phase evaporation vesicles, REV) in the liver depending on the concentration of Ch and SG in vivo; Ch tends to enhance liposomes containing 10 mol% SG accumulation in the liver, but to decrease those containing 20 mol% SG, and it prolongs the circulation in blood. Dicetylphosphate did not enhance liver targeting by liposomes with SG and Ch. More DPPC/SG/Ch-liposomes (6:1:3) were significantly taken up by cultivated hepatocytes than DPPC/SG/Ch-liposomes (6:0:4), suggesting a glucose residue. The optimal composition for the maximal liver targeting was a mixture of 0.2 micron DPPC/SG/Ch-liposomes (REV) at a molar ratio of 6:1:3. This composition of liposomes was distributed 3 times greater in hepatocytes than non-parenchymal cells 1 h after intravenous injection.

Confirmation of the structure of lipid A derived from the lipopolysaccharide of Rhodobacter sphaeroides by a combination of MALDI, LSIMS, and tandem mass spectrometry

The chemical structure of nontoxic diphosphoryl lipid A from Rhodobacter sphaeroides was confirmed using a combination of LSIMS (on a two-sector mass spectrometer) and MALDI (on time-of-flight and ion trap mass spectrometers) in conjunction with tandem mass spectrometry in both positive and negative ion modes. Accurate molecular weight measurement accompanied by the analysis of fragment ion masses yielded the composition of fatty acyl groups. Tandem experiments (collisionally induced dissociation of both quasimolecular and oxonium ions) were also performed, revealing the precise location and nature of the fatty acyl groups on the disaccharide backbone.

The utility of p53 immunostaining of transbronchial biopsy specimens of lung cancer: p53 overexpression predicts poor prognosis and chemoresistance in advanced non-small cell lung cancer

There are few reports on the p53 status of small cell lung cancer (SCLC) and advanced non-SCLC (NSCLC) because surgically resected specimens are generally not available. Therefore, we evaluated p53 immunostaining in 175 transbronchial biopsy (TBB) specimens obtained from patients with all stages of lung cancer and retrospectively evaluated the relationship between p53 status and clinical parameters. All of the specimens were obtained prior to therapy. Formalin-fixed, paraffin-embedded TBB specimens were immunostained using an anti-p53 antibody (DO-1). p53 protein was detected in 55% (61 of 111) of NSCLCs and 58% (37 of 64) of SCLCs. The rate of positivity increased significantly with increasing stage (stages I and II, 45%; stage III, 54%; stage IV, 66%), but not with other clinical parameters. Ninety-five patients were evaluated for their response to chemotherapy. Positive staining for p53 correlated significantly with unresponsiveness to chemotherapy in NSCLC (response rate of 13 versus 60%; P = 0.006), but not in SCLC (80 versus 57%; P = 0.22). p53 positivity was a statistically significant negative prognostic factor for stage III and stage IV NSCLC (P = 0.02), but not for stage I and stage II NSCLC (P = 0.79). There was no survival difference relative to p53 status in SCLC (P = 0.35). These results indicate that p53 overexpression in TBB specimens predicts poor prognosis and chemoresistance in advanced stage NSCLC.

Mycolic acid biosynthesis: definition and targeting of the Claisen condensation step

Through the use of 2,2-[2H]palmitic acid pulse labeling of the whole cells of C. matruchotti and analysis by gas chromatography-mass spectrometry of the non-labeled and [2H]-labeled corynomycolates, we established a new mechanism for palmitate condensation devoid of the postulated carboxylation step. This evidence allowed the design and synthesis of several structurally related antagonists against the condensation reactions which were shown to possess potent in vivo activity against C. matruchotti with complete inhibition of growth on solid media at concentrations between 1-10 microg/ml. In addition, a cell-free in vitro assay of corynomycolate synthesis was developed to allow the screening of these and other antagonists.

Differences in the density of barosensitive neurons in the medulla of spontaneously hypertensive and Wistar-Kyoto rats

1. The density of barosensitive neurons in the medulla was examined in spontaneously hypertensive rats (SHR) and in normotensive Wistar-Kyoto (WKY) rats. In control experiments, rats were sham-operated, while in test experiments arterial baroreceptors were stimulated by pressor responses to i.v. administration of phenylephrine and the density of c-Fos-labelled neurons was immunocytologically examined. 2. In both control and test experiments, c-Fos-labelled neurons were distributed in cardiovascular control sites: the nucleus tractus solitarii (NTS) and the caudal and rostral ventrolateral medullas (CVLM/RVLM). 3. In both WKY rats and in SHR, the total density of labelled neurons in test experiments was significantly higher than in control experiments. 4. In control experiments, no significant difference was found in the distribution and density of labelled neurons in the NTS and in the CVLM/RVLM between rats and SHR. 5. In test experiments, no significant difference was found in the distribution and density of labelled neurons in the NTS between WKY rats and SHR. 6. In test experiments in SHR, the density of labelled neurons in the CVLM just caudal to the obex level was significantly higher than that in WKY rats, whereas the density of labelled neurons in WKY rats in the RVLM just rostral to the obex level was significantly higher than that in SHR. 7. These results indicate that stimulation of the arterial baroreceptor induces strain-specific differences in the density of barosensitive neurons in the CVLM/RVLM near the obex level.

Interferon-gamma differentially regulates CD80 (B7-1) and CD86 (B7-2/B70) expression on human Langerhans cells

CD80 (B7-1) and CD86 (B7-2/B70) have recently been identified in cultured human Langerhans cells (LCs), although their role and regulatory properties remain unclear. We present our comparison of the expression of the molecules, mRNAs and the function between CD80 and CD86 in human LCs treated by interferon gamma (IFN-gamma). We examined the regulatory properties of CD80 and CD86 expression in human LCs pretreated with IFN-gamma. Flow cytometric analysis indicated that the mean fluorescence intensity of CD86 but not CD80 was enhanced. However, the percentage modulation of both CD80 and CD86 positive cells were significantly up-regulated in a dose-dependent manner, after 48-h culturing with IFN-gamma. The regulatory properties of CD80 and CD86 mRNA expressions in human LC were studied using polymerase chain reaction methods. We found that both CD80 and CD86 mRNA of enriched LCs following IFN-gamma pretreatment for 12 h were higher than those without pretreatment. We have demonstrated that the primary allogeneic mixed epidermal cell-lymphocyte reaction induced by human LCs treated by IFN-gamma increased in a dose-dependent manner. There was a 61.5% inhibition by anti-CD86 monoclonal antibody and a 32.5% inhibition by anti-CD80 monoclonal antibody. These data indicate that the CD80 and CD86 expression of human LCs may be differently regulated by IFN-gamma.

Role of the major antigen of Mycobacterium tuberculosis in cell wall biogenesis

The dominant exported proteins and protective antigens of Mycobacterium tuberculosis are a triad of related gene products called the antigen 85 (Ag85) complex. Each has also been implicated in disease pathogenesis through its fibronectin-binding capacities. A carboxylesterase domain was found within the amino acid sequences of Ag85A, B, and C, and each protein acted as a mycolyltransferase involved in the final stages of mycobacterial cell wall assembly, as shown by direct enzyme assay and site-directed mutagenesis. Furthermore, the use of an antagonist (6-azido-6-deoxy-alpha, alpha'-trehalose) of this activity demonstrates that these proteins are essential and potential targets for new antimycobacterial drugs.

Glutathione derivatives enhance adriamycin cytotoxicity in a human lung adenocarcinoma cell line

We evaluated the effects of a panel of glutathione derivative (S-butyl, S-decyl, S-ethyl, S-heptyl, S-hexyl; S-methyl, S-nonyl, S-octyl, S-propyl and S-pentyl glutathiones) on glutathione-S-transferase activity in the cell lysates of a human lung cancer, PC-9. Glutathione derivatives inhibited glutathione-S-transferase activity in PC-9 cell lysates by up to 67%. When PC-9 cells were incubated with the IC50 concentration of adriamycin (200 nM) and with nontoxic concentrations (1 microM) of the glutathione derivatives, cytotoxicity ranged from -20% to +55% of the control levels. Enhancement of adriamycin toxicity by glutathione derivatives was significantly correlated with the inhibition of glutathione-S-transferase activity. S-decyl-glutathione, which was one of the most potent inhibitors of glutathione-S-transferase activity, significantly enhanced the adriamycin-induced antitumor effect in vivo. Findings suggest that some glutathione derivatives, including the S-decyl, S-octyl, and S-hexyl glutathiones, enhance adriamycin-induced cytotoxicity in part by inhibiting glutathione-S-transferase and that these agents may be useful as chemosensitizers for adriamycin therapy. In conclusion, the present results showed that some glutathione derivatives enhanced sensitivity of tumor cells to ADR by inhibiting GST activity. The use of BSO and EA as sensitizers to chemotherapy is currently being evaluated in clinical trials. The present data suggest that the use of GSH derivatives to modulate GST activity may improve the response to ADR.