[Flow cytometric analysis of the DNA content of resected non-small cell lung cancer with reference to long-term follow-up]

We measured the cellular DNA content of paraffin-embedded tumor specimens by flow cytometry from 340 cases of resected non-small cell lung cancer, and investigated the correlation of DNA content and prognosis of these cases with long-term follow-up. These 340 cases were divided into some populations according to pathological stage, histologic type, surgical curativity and N factor, and we compared the prognosis of DNA diploidy cases and DNA aneuploidy cases in each population. DNA aneuploidy cases had a significantly less favorable prognosis than DNA diploidy cases in population of stage I adenocarcinoma, stage IIIA non-small cell lung cancer and N2 cases among stage IIIA non-small cell lung cancer, all after curative operation. But in other populations, there was no significant difference in prognosis between DNA diploidy cases and DNA aneuploidy cases. In conclusion, DNA ploidy pattern is a prognostic factor for survival in patients with stage I adenocarcinoma and N2 cases of stage IIIA non-small cell lung cancer.

Effects of lipopolysaccharide on the expression of fibrinolytic factors in an established cell line from human endothelial cells

Human endothelial cells express antithrombotic properties by producing prostacyclin, heparan sulphate and plasminogen activator (PA). Bacterial extract, such as lipopolysaccharide (LPS), damaged the blood vessels and destroyed the balance between the antithrombotic and thrombotic functions of endothelial cells. The fibrinolytic system is involved in antithrombotic functions. The TKM-33 cell line was established from human endothelial cells. In order to determine whether TKM-33 is a good fibrinolytic system endothelial cell expression model, the expression of fibrinolytic factors in TKM-33 cells treated with or without LPS was studied. The endothelial cells which had not been treated with LPS produced and secreted a large amount of urokinase-type PA (u-PA), and small amounts of tissue-type PA (t-PA) and PA inhibitor-1 (PAI-1), which were identified immunohistochemically and by electrophoretic enzymography. Diisopropylfluorophosphate-treated 125I-u-PA bound specifically to acid-treated monolayered endothelial cells with a Kd of 2.83 +/- 0.61 nM, and Bmax of (0.11 +/- 0.01) x 10(6) sites/cell. u-PAR expression was detected in endothelial cells by Northern blot analysis. Thus, endothelial cells was shown to express u-PAR which binds u-PA specifically. In the binding assay, the stimulation of endothelial cells with 0.1, 1.0 and 10 micrograms/ml of LPS altered the Kd values to 6.04 +/- 0.71, 7.03 +/- 1.55 and 7.38 +/- 1.03 nM, respectively. However the Bmax values did not change significantly. Although LPS treatment increased u-PAR expression in endothelial cells in a dose-dependent manner, the expression of u-PA and t-PA mRNAs was not altered significantly. LPS stimulation (10 micrograms/ml) increased the expression of PAI-1 mRNA, significantly. The PA activity recovered from the cell surface fraction was not affected by LPS stimulation, but the PAI-1 activity was increased. These findings suggest that the established endothelial cell line, TKM-33, possesses the characteristics of endothelial cells and they express u-PAR on their cell surface, which is occupied by intrinsic u-PA secreted from the cells, and that treatment of endothelial cells with LPS changes the cell surface characteristics and inhibited the u-PAR expression thus promoting the prothrombotic function concomitantly with increased PAI-1 activity.

Biochemical characterization of a Pseudomonas fluorescens strain isolated from a benzalkonium chloride solution

A bacterium isolated as the contaminant of a batch of commercial benzalkonium chloride (BAC) solution (10% (w/v)) stored in a loosely capped bottle in the Department of Pharmacy Shinshu University Hospital was identified as Pseudomonas fluorescens belonging to biotype G of Stanier, et al. The strain was highly resistant to BAC, and the lowest concentration of BAC that inhibited visible growth of the strain as measured on nutrient agar plates was > or = 5000 micrograms/ml. BAC is a typical quaternary ammonium detergent. Thus we examined the tolerable growth concentration of various strains on surfactants. We were able to confirm growth of P. fluorescens of BAC resistance strain (PFRB) in 5% concentration, but the other strains were not able to grow in 0.1% concentration. We investigated the relationship between biotype and resistance to BAC. PFRB and three clinical isolated strains were found to be the same biotype G. However, no apparent correlation was found between the same biotypes and minimum inhibitory concentration (MIC) of disinfectant or growth permissible concentration on surfactants. The strain was unable to decompose BAC, as no growth occurred in the minimum medium containing BAC as the sole source of carbon, nitrogen or both. Our finding caused us to realize that P. fluorescens might also be a contaminant of disinfectants, as we have seen in Pseudomonas cepacia.

[A case of chronic tuberculous pyothorax associated malignant lymphoma]

The patient was 69-year-old male. He has a history of treatment for tuberculosis by artificial pneumothorax about 47 years ago. He was admitted an another hospital under the diagnosis of tuberculous pyothorax. He was transferred to our hospital because of chest pain and fever. Laboratory findings on the admission were as follows: ESR was 120 mm/hr, CRP was 20.22 mg/dl and other data were almost within normal limits. Chest X-ray showed a massive shadow in the right lower lung field, adjacent to the chest wall. Computed tomography (CT) showed tumor shadow with low density and invasions into the adjacent chest wall. Histological examination of surgically excised tumor biopsy revealed malignant lymphoma. The patient's condition improved and the size of tumor decreased temporarily by chemotherapy. Then, he began to complain of chest pain and high fever, and tumor in the chest wall invaded into the whole chest wall. He died of disseminated intravascular coagulation despite continuing chemotherapy. Postmortem examination revealed the following findings : the tumor existed mainly in the parietal pleura or the chest wall, adjacent to the lesion of pyothorax, and immunohistochemical examination showed that tumor was malignant lymphoma, diffuse, large B-cell type. Recent studies have shown a close association between EBV infection and pyothorax-associated lymphoma. We have to keep in mind the possible development of malignant lymphoma following tuberculous pyothorax, when we see patients complaining of fever or chest pain with tuberculous pyothorax.

Adult respiratory distress syndrome induced by a Chinese medicine, Kamisyoyo-san

We report the first case of Kamisyoyo-san-induced adult respiratory distress syndrome (ARDS). A 59-year-old female was given Kamisyoyo-san for treatment of seborrheic dermatitis. She then presented with a respiratory illness having clinical, radiologic and functional characteristics of ARDS. Bronchoalveolar lavage fluid showed an increased number of lymphocytes, neutrophils and eosinophils. The lymphocyte stimulation test with Kamisyoyo-san was positive.

Mutagenicity of chemicals produced from sodium dodecylbenzenesulfonate by treatment with ozone and ultraviolet irradiation

The interaction of formaldehyde and glyoxal produced from linear dodecylbenzenesulfonate (DBS) in aqueous solution after simultaneous treatment with ozone and ultraviolet (UV) irradiation and the effect of DBS on the mutagenic activity of formaldehyde and glyoxal were investigated. The decomposition of DBS in aqueous solution resulted in the formation of the mutagens formaldehyde and glyoxal as intermediate products after the simultaneous treatment for 4 hr. Therefore, the aqueous solution containing decomposed DBS after the treatment for 4 hr was mutagenic for Salmonella typhimurium strains TA100 and TA104 in the presence and absence of S9 mix. However, the mutagenic activity was greater than the sum of the mutagenic activity of formaldehyde and glyoxal formed from DBS. The aqueous solution mixed with formaldehyde and glyoxal did not increase the mutagenicity above the sum of the mutagenic activity in the presence or absence of DBS. Furthermore, DBS at concentrations of 2.0 micrograms/plate or less did not affect the mutagenicity of the mixtures containing formaldehyde and glyoxal. In addition, there was little bacteriocidal effect of the mixed solution on the mutagenicity test strains. These results suggest that unidentified mutagenic intermediate products were produced from DBS after simultaneous treatment with ozone and UV irradiation for 4 hr.

Discrimination of two functions of photoreceptor cGMP phosphodiesterase gamma subunit

cGMP phosphodiesterase, a key enzyme in phototransduction, is composed of P alpha beta and two P gamma S. P gamma has two functions in P alpha beta regulation: (I) an inhibitor of cGMP hydrolysis and (II) a stimulator of cGMP binding to their noncatalytic sites. Here we show for the first time that these functions can be discriminated. P gamma release by GTP-bound transducing from P alpha beta was stimulated by NaCl in a concentration-dependent manner. However, phosphodiesterase activity in membranes washed with NaCl-free buffer already reached the maximum level. [3H]-cGMP binding of P alpha beta in membranes washed with NaCl required more P gamma than that in membranes washed without NaCl. Other salts had a similar effect. Identical P gamma was released under different [NaCl]. These results indicate that P gamma for the function (I) is released in low [salt], but P gamma for the function (II) is released in high [salt]. These P gamma functions may be expressed separately in phototransduction.

Two-color interferometer for surface characterization using two frequency doublers and a four-phase-step method

A high-accuracy, two-color interferometer for characterizing a processed surface is described. It is composed of two frequency doublers. It is not affected by air turbulence and mechanical vibration because it is a complete common-path interferometer, and the effects from different reflectivities of various materials are canceled by a four-phase-step technique that shifts the phase of the interference fringe in steps of π/2. The processed surface is measured with subnanometer resolution.

Effects of postnatal exposure to cocaine on the development of the rat corpus callosum

We investigated the effects of cocaine on the development of the corpus callosum in rats. From postnatal days 1 (P1) to 10 (birth = P0), cocaine (10 mg/kg) was subcutaneously injected in the pups, and saline, at the same volume, was administered to control pups. The animals were sacrificed at 110 days of age and a midsagittal section of the callosum was obtained. Morphometric measurement of the corpus callosum was performed in this section. In the control group, but not in the cocaine group, males had larger callosa than females. The cocaine treatment significantly decreased the total callosal area in male rats. These findings indicate that early postnatal cocaine abolishes the sexual differentiation of the corpus callosum.

Assessment of diazepam loading dose therapy of delirium tremens

The efficacy of the diazepam loading dose method of treatment of delirium tremens was assessed in comparison with the traditional therapy. The experimental group and the control group comprised 51 and 45 patients respectively. The clinical institute withdrawal assessment for alcohol (CIWA-A) scale was applied to assess the intensity of the symptoms. Diazepam doses in the experimental group oscillated from 40 to 210 mg (mean 86.9 +/- 47.2 mg). The control group was receiving diazepam and other psychotropic drugs in divided doses. In the experimental group deliric symptoms were present from 2 to 24 h (mean 6.9 +/- 4.8 h), and in the control group from 2 to 123 h (mean 33.8 +/- 25.7 h). The results show a large efficacy of the loading dose method corresponding to substantial reduction of the psychosis duration (fivefold in comparison to the control group). The method proved to be safe, with no significant complications.

Antimetastatic effect of a novel indolocarbazole (NB-506) on IMC-HM murine tumor cells metastasized to the liver

IMC-HM cells were isolated from spontaneously induced ascitic IMC carcinoma cells that had been maintained intraperitoneally in CDF1 mice. Metastasis to the liver of subcutaneously implanted IMC-HM cells was detected 10 days after implantation into the flanks of mice (day 10), but metastasis to other organs was limited. Thereafter, however, tumor cells spread rapidly to lymph nodes, lung, spleen, ovary and other organs, and the mice died on day 13 to 18. We report here, together with the properties of IMC-HM cells, the effects of adriamycin, cisplatin, etoposide and a new indolocarbazole antitumor compound (NB-506) on this model of metastasis. Although these anticancer agents all inhibited the growth of the subcutaneous tumors, their effects on the life span of the tumor-bearing mice varied. Treatment with NB-506, started on day 1, more than doubled the survival period at doses 30 mg/m2 to 900 mg/m2. Further, treatment with NB-506, started on day 4 after resection of the primary tumor, inhibited growth of the metastasized tumor in the liver and other organs. Etoposide also increased the life span at a limited range of doses. However, the life-prolonging effects of adriamycin and cisplatin were marginal. These results demonstrate that IMC-HM carcinoma is a good model for spontaneous metastasis to the liver followed by lethal spread to many organs. Moreover, NB-506 was found to be highly effective against the growth not only of subcutaneous tumors, but also of tumors metastasized to the liver.

Inhibitory effect of arachidonic acid on platelet-activating factor production in rat neutrophils

Platelet-activating factor production in rat neutrophils in response to opsonized zymosan was suppressed dose dependently in the presence of 10-100 microM arachidonic acid. The amount of lyso-PAF was also reduced by these doses of arachidonic acid. Phospholipase A2 activity was not changed by addition of arachidonic acid up to 100 microM, but acetyltransferase activity was slightly reduced at a 100 microM concentration of arachidonic acid. Pretreatment with indomethacin did not alter the inhibitory effect of arachidonic acid on PAF production, indicating no involvement of cyclooxgenase products. Triacsin C, an acyl-CoA synthetase inhibitor, reversed the arachidonic acid-induced suppression of lyso-PAF and PAF production, suggesting that arachidonic acid might exert its inhibition via the acylation pathway of lyso-PAF to reduce the availability of lyso-PAF.

Inhibitory effects and toxicity of green tea polyphenols for gastrointestinal carcinogenesis

BACKGROUND

Recently, and epidemiologic study showed a lower risk of gastrointestinal carcinogenesis in green tea drinkers. An experiment on two-stage skin carcinogenesis in mice showed that (-)-epigallocatechin gallate (EGCG), one of the main constituents of green tea, inhibited tumor formation.

METHODS

The inhibitory effects of EGCG and green tea extract (GTE) on N-ethyl-N'-nitro-N-nitroguanidine (ENNG)-induced duodenal carcinogenesis in the mouse, N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced carcinogenesis of the glandular stomach in the rat, and azoxymethane-induced colon carcinogenesis in the rat were examined. The toxicity of GTE was assessed experimentally and GTE was applied clinically in normal volunteers to determine the effective dose and to assess its harmful effects.

RESULTS

EGCG and GRE inhibited chemical carcinogenesis of the gastrointestinal tract in rodents. Judging from the epidemiologic and experimental findings, it was determined that 1 g per day of GTE might be an effective dose. GTE was not toxic and no harmful effect was found during its clinical use.

CONCLUSIONS

These findings suggest that EGCG and GTE are useful in preventing gastrointestinal carcinogenesis, and the clinical usefulness of GTE, which has no harmful effects and is inexpensive, should be studied further.

Effects of a hepato-protective agent and a hepato-secreting chelator on cadmium-induced nephrotoxicity in Syrian hamsters

Cadmium (Cd)-induced nephropathy in male Syrian hamsters was treated with D/L-penicillamine (D/L-p) or neomynophagen C (NMC). The subcutaneous injection of CdCl(2), 3 mg/kg, three times a week led to marked renal damage, ie., increased proteinuria and the excretion of urinary N-acetyl-beta-D-glucosaminidase (NAG) as compared with the saline-injected controls. Cd-treated hamsters that were injected intraperitoneally with D/L-p, 0.1 mg/kg, five times a week, showed less renal damage, including a reduction in urinary protein from 3.60 + or - 0.42 to 1.77 + or - 0.7 mg/d. NMC-treated hamsters showed a reduced excretion of NAG (from 1.47 +/ - 0.34 to 0.91 + or - 0.68 u/d). The concentration of Cd in renal cortical tissue was reduced slightly (from 2.78 + or - 0.08 to 2.34 + or - 0.3 mg/g.prot) by NMC treatment, but not by D/L-p. The elevated malondialdehyde (MDA) in renal cortical tissue was unaffected by administering D/L-p or NMC. The concentration of glutathione (CSH) in the renal cortex was not elevated after administering Cd, but the ratio of the reduced to the oxidized GSH was elevated. The Cd induced liver dysfunction, as compared with untreated controls. The dysfunction was improved slightly by NMC administration, but not by that of D/L-p. Changes in renal morphology induced by Cd involving marked degeneration and necrosis of tubules as shown by light microscopy, were unaffected by treatment with D/L-p or NMC. We thus demonstrated the efficacy of D/L-p of NMC in treating the nephropathy induced by Cd in hamsters. The mechanism of therapeutic effect is not known.

Pharmaceutical properties of freeze-dried formulations of egg albumin, several drugs and olive oil

The freeze-dried ternary formulations of meclizine (MZ, an anti-motion sickness drug), prednisolone (PRED, an anti-inflammatory drug) and norfloxacin (NFLX, an anti-microbial drug) which are poorly water-soluble and are low bioavailability drugs, were prepared using egg albumin and olive oil. The powder X-ray diffractions, the dissolution rate and the bioavailabilities in vivo of these formulations were studied in comparison with each drug alone. By forming ternary formulations of these drugs, the dissolution rates of the drugs from the formulations were significantly improved compared with each drug alone. The results of their powder X-ray diffraction measurements showed that these drugs in the ternary formulations presented in an amorphous form, indicating increased dissolution rates. On the other hand, the plasma concentrations of these drugs increased significantly after oral administration in formulations to rats, except for the NFLX formulation, and the areas under the concentration-time curves (AUC) of the ternary formulations of MZ, PRED and NFLX were 2.1, 1.6 and 1.3 times those of the drugs alone, respectively. From these results, it was proven that formulations consisting of egg albumin, olive oil and poorly water-soluble drugs were useful preparations for improving the drug's disadvantageous pharmaceutical properties.

Death caused by undiagnosed acute pancreatitis

A fatal case of acute pancreatitis is reported. On account of difficulty in eating caused by persistent dysphagia and heartburn, the clinical condition of a 39-year-old man who had been a heavy drinker deteriorated rapidly. He was taken to a hospital in an ambulance in an unconscious state. Based on the endoscopic examination and blood chemistry data, the diagnosis of hemorrhagic esophagitis and hepatic failure was made. Treatment including fluid infusion was unsuccessful and he died on the second hospital day. Based on a strong suspicion that the pathologic change in the esophagus may have been chemical esophagitis caused by corrosives of some type, the police ordered an administrative autopsy. The postmortem examination revealed marked necrosis in the pancreas and in the abdominal fatty tissue including the omentum and the mesentery. The necrotic areas in the pancreas were accompanied by only a slight degree of hemorrhage. The cause of death was diagnosed as acute pancreatitis. The pathologic change in the esophagus was identified as Candida esophagitis. Alcohol abuse and malnutrition caused by esophagitis were both considered to be factors which lead to the acute fatal pancreatitis.

Mutations of the Btk gene in 12 unrelated families with X-linked agammaglobulinemia in Japan

Alterations of the Bruton's tyrosine kinase (Btk) gene are responsible for X-linked agammaglobulinemia (XLA). Although mutations in various regions were reported mainly in the Caucasian population, correlation between the locations of mutation and the clinical phenotypes remains unclear. We report 12 abnormalities of the Btk gene found in 12 unrelated families out of 14 XLA families in Japan and their clinical features. We utilized Southern blotting and single-strand conformation polymorphism (SSCP) analysis. Gene rearrangement in the kinase domain was identified in two patients by Southern blotting. Seven point mutations, two small deletions, and one small insertion were detected by SSCP and sequencing. The SSCP analysis also provided information about the carriers in these families. We found some clinical heterogeneity in the affected family members with the same gene mutation. Moreover, there is considerable inconsistency between the locations of gene aberrations and the immunological phenotypes. Some patients with a nonsense mutation, which may result in the lack of kinase domain, have detectable B cells and immunoglobulins. These identified alterations will provide valuable clues to the Btk protein function and the pathogenesis of XLA.

The effect of ultra-low sodium dialysate in CAPD. A kinetic and clinical analysis

In peritoneal dialysis, sodium (Na) passes through the peritoneal membrane to a lesser extent than H2O and thus hypotonic fluid is removed indicating that Na removal is inefficient. Therefore we developed an ultra-low Na dialysate (ULNaD) [Na 98 mmol/liter, osmolality 340 mOsm/kg, glucose (G), 2.48%] to facilitate trans-peritoneal Na removal. The aim of the study was to examine (a) the fluid and Na kinetics of this solution, and (b) the clinical effect in the overhydrated patient. Regarding the former, in six cases, changes in the effluent Na levels during a 240-minute dwell of ULNaD were measured at 60-minute intervals. In eighteen cases, the transperitoneal net-Na removal (Na removal) and drained ultrafiltration (UF) volume after a 240-minute dwell of ULNaD were measured and compared to two types of standard Na dialysate (SNaD) [Na 132 mmol/liter, 1.36% G (348 mOsm/kg) and 2.27% G (396 mOsm/kg)]. The effluent Na levels increased gradually until the end of the dwelling. Drained UF volume of ULNaD (224 +/- 25 ml) was more than 1.36% G SNaD (77 +/- 33 ml, p < 0.01), but it was less than 2.27% G SNaD (341 +/- 32 ml, p < 0.01). However, a significant increase in Na removal by ULNaD (78.1 +/- 5.6 mmol) was found compared with both SNaD solutions (12.6 +/- 6.4 mmol in 1.36% G solution, p < 0.001; 27.8 +/- 5.1 mmol in 2.27% G solution, p < 0.001, respectively). Regarding the latter study aim, in six overhydrated patients with a Na excess, SNaD was replaced with ULNaD once a day for 7 consecutive days. At the end of the study as compared to the pre-values, a significant reduction in body weight (-2.5 +/- 1.0%, p < 0.05) and mean arterial pressure (-12.3 +/- 3.5%, p < 0.001) was observed. An increased drainage of daily UF volume (+86.5 +/- 31.1%, p < 0.05) and a markedly increased daily Na removal (+131.1 +/- 24.2%, p < 0.01) were also observed. The results of this study suggest that ULNaD actually facilitates trans-peritoneal Na removal mainly by diffusion force, and that ULNaD could benefit overhydrated patients with a Na excess.

[Comparative study on the efficacy of ritipenem acoxil and cefotiam hexetil in chronic lower respiratory tract infections by the double-blind method]

To objectively evaluate the efficacy, safety and usefulness of the newly developed penem oral antibiotic, ritipenem acoxil (RIPM-AC), against chronic lower respiratory tract infections, we conducted a multi-center double-blind comparative study using cefotiam hexetil (CTM-HE) as a control drug. RIPM-AC was orally administered at 200 mg, and CTM-HE at 400 mg, t.i.d. for 14 days, in principle. The results were as follows: The total number of patients enrolled in this trial was 202, of which 151 cases (RIPM-AC group: 75, CTM-HE group: 76) were evaluable for clinical efficacy. 1. The clinical efficacy rates (excellent+good) were 85.3% (64/75) in the RIPM-AC group and 80.3% (61/76) in the CTM-HE group. There was no significant difference between the two groups, hence the clinical equivalency of RIPM-AC to CTM-HE was demonstrated. 2. In the patients enrolled in the evaluation of clinical efficacy, the eradication rates of the causative organisms were 50.0% (13/26) in the RIPM-AC group and 75.0% (18/24) in the CTM-HE group, with no significant difference between the two groups. 3. Side effects were noted in 10 cases (11.0%) of the RIPM-AC group and 10 cases (10.9%) of the CTM-HE group. Abnormal laboratory test findings were observed in 8 cases(9.5%) of the RIPM-AC group and in 14 cases (16.7%) of the CTM-HE group. There were no significant differences between the two groups in the incidence of side effects and abnormal laboratory test findings. In the safety evaluation, RIPM-AC was judged to be safe in 73 cases (80.2%) and CTM-HE in 71 cases (77.2%), with no significant difference. 4. The usefulness rates (markedly useful+useful) were 79.5% (62/78) in the RIPM-AC group and 76.9% (60/78) in the CTM-HE group. There was no significant difference between the two groups. Since RIPM-AC showed clinical efficacy similar to those of CTM-HE and posed no particular safety problems, it is expected to be a useful antibiotic for the treatment of chronic lower respiratory tract infections.

Effects of calcium channel blockers on cultured rat embryos

Gestational day 11 rat embryos were cultured for 20 h in the presence of nifedipine (NIF), diltiazem (DIL) and verapamil (VER), and the effects of these calcium channel blockers on embryonic heart rate and gross morphology were examined. Reductions of embryonic heart rate were dose dependent and reversible. Effects on the heart rate were seen at doses as low as 0.3, 1 and 20 micrograms ml-1 for VER, DIL and NIF, respectively. Retardation of embryonic growth and morphological abnormalities, which were related to circulation defects, were seen at termination. The minimum doses to produce 100% effect on gross morphology were 2, 6 and 40 micrograms ml-1 for VER, DIL and NIF, respectively. These findings suggest that embryolethality seen in vivo studies is partly due to circulation defects and the associated morphological abnormalities in rats.

A radioresistant variant cell line, NMT-1R, isolated from a radiosensitive rat yolk sac tumour cell line, NMT-1: differences of early radiation-induced morphological changes, especially apoptosis

A radioresistant variant cell line, NMT-1R, was isolated by repeated radiation exposure of a radiosensitive rat yolk sac tumour cell line, NMT-1, producing alpha-fetoprotein, with the potential for lymphatic metastasis in the inbred Wistar rat. Cultured NMT-1R cells showed more cobblestone-like appearances, although the morphological features were almost the same as radiosensitive NMT-1 cells reported previously. The doubling time of NMT-1R cells was 13.6 h, being shorter than that of NMT-1 cells (16.0 h). For NMT-1R cells, D0 for radiation sensitivity was 165 +/- 3 cGy, 1.7 times as large as for NMT-1 cells. The extrapolation number, n, was 1.48 +/- 0.17 for NMT-1R cells although that for NMT-1 cells was 1.08 +/- 0.15. The surviving fractions at 2 Gy (SF2) were 0.42 for NMT-1R cells and 0.28 for NMT-1 cells. The population of G2-M phase for NMT-1R cells was larger than for NMT-1 cells (32.5 versus 26.8%) in exponentially growing cells. Although a clear G2 delay was observed after irradiation with a dose of 182 cGy for both cell lines, NMT-1R cells had a shorter recovery time from G2 block than NMT-1 cells, G1 arrest was observed in NMT-1 cells. NMT-1 cells showed much higher incidence of early morphological changes, especially apoptosis, after irradiation with a dose > 500 cGy compared with NMT-1R cells.

Investigation on neurotoxicity of occupational exposure to cyclohexane: a neurophysiological study

OBJECTIVES

To examine the effect of occupational exposure to cyclohexane on the peripheral nervous system.

METHODS

A nerve conduction study was performed on 18 workers exposed to cyclohexane in a luggage factory and on age and sex matched occupationally unexposed controls. 12 workers had been exposed to n-hexane (median 2.8 years) before the start of exposure to cyclohexane. To confirm the effect of exposure, a follow up study was performed on nine workers one year after the first study. The mean exposure to cyclohexane was 1.2 years in the first study. A symptom survey was performed. The exposure was measured by air sampling of the breathing zone of each worker. The urinary metabolite cyclohexanol was also monitored.

RESULTS

The concentration of airborne cyclohexane ranged from 5 to 211 ppm. The urinary concentration of cyclohexanol ranged from 0.12 to 1.51 mg/l. There was a strong correlation between the cyclohexane exposure in personal air and urinary cyclohexanol. No differences were found in nerve conduction velocities (NCV) between workers exposed to cyclohexane and age and sex matched controls. The results of the follow up study showed significant improvements in peroneal motor NCV (P < 0.01) and sural sensory NCV (P < 0.05) and in ulnar motor distal latency (MDL, P < 0.05) and peroneal MDL (P < 0.05) compared with the first study. Although the past n-hexane exposure affected the first neurophysiological study, the effect had disappeared in the second study, one year later.

CONCLUSION

Occupational exposure to the concentrations of cyclohexane experienced in this study had no adverse effects on the peripheral nervous system.

Evidence that cytochrome P-4502E1 contributes to ethanol elimination at low doses: effects of diallyl sulfide and 4-methyl pyrazole on ethanol elimination in the perfused rat liver

The roles of cytochrome P-4502E1 and alcohol dehydrogenase (ADH) on ethanol (EtOH) hepatic elimination was examined in the perfused rat liver. EtOH concentration-time curves of outflow after instantaneous administration (0.46 mg) through the portal vein with or without perfusion of diallyl sulfide (DAS), a selective cytochrome P-450E1 inhibitor, and/or 4-methyl pyrazole (4-MP), a classical ADH inhibitor, were analyzed by the statistical moment analysis and the compartment dispersion model. Recovery ratios obtained by moment analysis significantly changed with perfusion of inhibitors (p < 0.01). Values of the hepatic volume of distribution and the relative dispersion were significantly higher by the perfusion of DAS and 4-MP (p < 0.01). In the two-compartment dispersion model, the partition ratio (K') and the first-order elimination constant (K0) were decreased significantly by DAS (p < 0.05). By the addition of 4-MP, the blood volume of distribution (VB) and the backward partition rate constant (k21) were increased significantly (p < 0.05). K sigma values were decreased significantly to 0 (p < 0.001). The decrease of elimination rates by DAS and/or 4-MP shows the inhibition of metabolic pathways. The change of V beta and k21 caused by DAS and 4-MP indicates that EtOH taken into hepatic tissues was not metabolized and flowed out into the perfusates. Inhibition rates calculated from the efficiency number with addition of DAS and DAS + 4-MP were 40.7 and 99.3%. Therefore, cytochrome P-4502E1 and ADH accounted for 40 and 60% of the hepatic EtOH elimination at low doses.

Metabolism of barnidipine hydrochloride, a potent calcium antagonist, in rat and dog

1. In vitro experiments in the rat indicated that barnidipine was metabolized extensively in the liver and was catalyzed by P450s. 2. After oral dosing, nine metabolites were identified in the urine and bile of rat and dog. No unchanged drug was detected in urine and bile. Ester hydrolysis and pyridine formation were the main metabolic pathways in urine in both species, whereas glucuronide conjugates of the debenzylated metabolite and the hydrolyzed pyrrolidine ester were noted in bile. 3. The metabolism of barnidipine in the rat and dog were qualitatively similar. Metabolites are generated by one or several of the following pathways: (a) N-debenzylation of the side chain, (b) hydrolysis of the pyrrolidine ester, (c) oxidation of the dihydropyridine ring to a pyridine ring, (d) hydrolysis of the methylester, (e) reduction of the nitro group to the amino group, and (f) conjugation of the generated metabolites with glucoronic acid.