High-dose chemotherapy with peripheral blood stem-cell transplantation for hormone-refractory advanced carcinoma of the prostate: experience of two cases

Two patients with hormone-refractory advanced prostate cancer were treated with high-dose chemotherapy and peripheral blood stem-cell transplantation. A satisfactory number of stem cells were collected by appropriately timed leukapheresis in these patients. The stem-cell samples collected from the first patient were positive for prostate-specific antigen messenger ribonucleic acid expression; such expression was not detected in the samples from the second patient. The first patient has remained in complete remission as of December 1995. The second patient died of the disease.

Comparison among performances of a ligase chain reaction-based assay and two enzyme immunoassays in detecting Chlamydia trachomatis in urine specimens from men with nongonococcal urethritis

We evaluated the performances of a ligase chain reaction (LCR)-based assay and two enzyme immunoassays (Chlamydiazyme and IDEIA) in the detection of Chlamydia trachomatis in urine specimens. We compared the results of testing urine specimens by these assays with those of urethral swab culture by examining samples from 131 men with nongonococcal urethritis. Discrepant results were analyzed by testing urethral swab specimens for C. trachomatis by a PCR-based assay. After the resolution of discrepant results, the sensitivity of urethral swab culture was 85.3%, whereas those of the LCR assay, Chlamydiazyme, and IDEIA with urine specimens were 94.1, 82.4, and 94.1%, respectively. The LCR assay and IDEIA were more sensitive than was urethral swab culture. In addition, the LCR assay, with a sensitivity equal to that of IDEIA, was more specific. Overall, the LCR assay proved to be superior to the enzyme immunoassays in detecting C. trachomatis in urine specimens. Testing urine specimens by LCR assay should be a helpful alternative method for diagnosing C. trachomatis urethral infection in men with nongonococcal urethritis.

Detection of low-level expression of P-glycoprotein in ACHN renal adenocarcinoma cells

A highly sensitive reverse transcriptase-polymerase chain reaction (RT-PCR) assay and a flow cytometric assay were used to examine ACHN cells for the expression of P-glycoprotein. The expression of P-glycoprotein was detected at the RNA and protein levels in ACHN cells by RT-PCR and flow cytometry, respectively. However, it was below the limit of detection by immunoblotting. The intracellular accumulation of adriamycin in ACHN cells was enhanced by verapamil, cyclosporin A and medroxyprogesterone acetate. Therefore, this study has demonstrated that low-level expression of P-glycoprotein detectable only by RT-PCR and flow cytometry plays a significant role in reducing the intracellular concentration of antitumor agents and thus contributes to the multidrug-resistant phenotype of ACHN cells.

[Unilateral multicystic dysplastic kidney in an adult: report of a case]

A case of unilateral multicystic dysplastic kidney in a 52-year-old woman is reported. Two abnormal round-like calcifications in left upper quadrant abdomen were found on upper gastrointestinal roentgengraphy for health screening. The computerized tomographic (CT) scan revealed a very small left kidney which was not enhanced and the ring and diffuse calcifications in it. It was not visualized by drip infusion pyelography. Left nephrectomy was performed. The kidney, which was very small, had two cysts the walls of which were calcified. The left ureter and renal vessels were absent. Histological appearance shows typical multicystic dysplastic kidney (MCDK). Literature is reviewed. However, the therapy for MCDK is still controversial.

Calbindin-D28k-immunoreactivity in the trigeminal ganglion neurons and molar tooth pulp of the rat

The cell body size and coexpression of carbonic anhydrase (CA), calretinin (CR) and calcitonin gene-related peptide (CGRP) of primary neurons with calbindin-D28k (CB) was examined in the trigeminal ganglion (TG) of the rat. CB-immunoreactive (-ir) cells were mostly large and preferentially distributed in the maxillary and mandibular divisions of the TG. 48% of CB-ir TG cells exhibited enzyme CA activity. 10% of CB-ir TG cells contained CR-ir. Most TG cells coexpressing CB- and CR-irs were localized to the maxillary and mandibular divisions and exhibited CA activity. 6.5% of CB-ir TG cells coexisted with CGRP-ir. 46% of TG cells coexpressing CB and CGRP exhibited CA activity. The innervation of the molar tooth pulp by CB-ir TG primary neurons was also examined. CB-ir thick and smooth nerve fibers projected from the root pulp to the pulp horn and the roof of the pulp chamber, where they became thinner and rarely entered the subodontoblastic layer. However, they could not be traced to the odontoblastic layer, predentin or dentine. The distribution pattern of CB-ir pulpal fibers was different from that of CR-ir ones. The trigeminal neurons cells retrogradely labeled with fast blue (FB) from the maxillary molar tooth pulp contained CB- and CR-irs. 23% and 1% of the labeled cells were immunoreactive for CB and CR, respectively. The coexpression of CB- and CR-immunoreactivities (-irs) in FB-labeled cells was negligible. An immunoelectron microscopic method revealed that 21% of pulpal nerve fibers were immunoreactive for CB, and that all CB-ir nerve fibers in the root pulp were myelinated. The present study indicated that the tooth pulp primary neurons contained CB-ir but did not coexpress CB- and CR-irs and that these neurons projected their myelinated axons to the pulp.

[Effects of amosulalol hydrochloride on intraocular pressure and aqueous humor dynamics in the rabbit eye]

The effects of amosulalol, which blocks alpha 1 adrenoceptors selectively and beta receptors nonselectively almost to the same extent, on intraocular pressure (IOP) and aqueous humor dynamics were studied in pigmented rabbits. Administration of topical amosulalol (0.5%) resulted in a significant difference in IOP between the treated and the contralateral eyes from 0.5 to 6 hours, and the maximum IOP reduction, 6.0 +/- 0.4 mmHg (mean +/- standard error), was observed at 2 hours after administration. Aqueous humor dynamics measurements (mean +/- standard error) in the amosulalol (0.5%)-treated and the contralateral eyes revealed that total outflow facility determined by the two-level constant pressure perfusion method was not significantly different, 0.14 +/- 0.01 and 0.12 +/- 0.01 microliter/min/mmHg, respectively; the aqueous flow measurements determined by fluorophotometry were 3.0 +/- 0.1 and 3.4 +/- 0.2 microliters/min, respectively (p < 0.05, -11%); the uveoscleral outflow measurements determined by the fluorescein isothiocyanate-dextran perfusion method were 0.53 +/- 0.04 and 0.46 +/- 0.04 microliter/min, respectively (p < 0.05, +15%). In conclusion, amosulalol lowers the IOP by inhibiting aqueous production and increasing uveoscleral outflow.

Quinolone-resistant Neisseria gonorrhoeae: correlation of alterations in the GyrA subunit of DNA gyrase and the ParC subunit of topoisomerase IV with antimicrobial susceptibility profiles

Fifty-five clinical strains of Neisseria gonorrhoeae were examined for mutations in the gyrA and parC genes and for antimicrobial susceptibility profiles. The MICs of quinolones for 31 strains with alterations in GyrA were significantly higher than the MICs for 24 strains without such alterations. Eleven strains with alterations in both GyrA and ParC were significantly more resistant to fluoroquinolones than those with alterations in GyrA alone. The MICs of cephalosporins for these strains were also significantly higher than those for other strains.

[Leiomyosarcoma of the scrotum: a case report]

A case of leiomyosarcoma of the scrotum is reported. A 44-year-old man referred to our hospital with the complaint of swelling of the left scrotal contents. The lesion was about 3 cm in diameter, isolated from testis, epididymis and spermatic cord. Ultrasonography revealed hypoechoic and slightly heterogenic area in the lesion. Surgical resection was easily done. Histological examination showed leiomyosarcoma. Adjuvant therapy was not performed. Three years after the resection, he is alive without any sign of recurrence or metastasis.

Failure to detect Mycoplasma fermentans, Mycoplasma penetrans, or Mycoplasma pirum in the urethra of patients with acute nongonococcal urethritis

Urethral swab specimens collected from 108 male Japanese patients with acute nongonococcal urethritis (NGU) and from 50 Japanese men without NGU were examined for the presence of Mycoplasma fermentans, Mycoplasma penetrans, and Mycoplasma pirum by means of polymerase chain reaction-based assays. These mycoplasmas were not detected in any of the specimens, which suggests that they are unlikely to have a pathogenic role in acute NGU.

Histological suture changes following retraction of the maxillary anterior bone segment after corticotomy

By cephalometric and dental cast analyses, the effects of corticotomy in combination with 45-50 days retraction of the maxillary anterior segment were evaluated in five female Japanese monkeys (Macaca fuscata). In addition, microscopic changes of the related sutures were examined. According to the analyses of the dental casts, the retraction of the maxillary anterior segment in the experimental group was increased when compared with that of the control group. There was no change in occlusal molar relationship. The cephalometric analysis revealed that the "Point A" and "Metal Implant" on the mid-sagittal site between the upper central incisors in the experimental group showed more pronounced retraction than that in two untreated control animals. These results were histologically evaluated by changes of the suture structure: irregularity of functional arrangement of component cells and fibers, an increase in number of cells, resorption and formation of bone, and an enlargement of the suture width. Resorption of tooth roots and alveolar bone, and irregularity of the periodontal ligament were observed. In general, these histological changes appeared more extensive in the control specimens compared with the experimental specimens. The osseous histological changes were mainly observed in the compact bone area, while in the spongy bone area of both control and experimental specimens only minimal changes occurred. These results demonstrated the efficacy of combining a corticotomy procedure with retraction of the maxillary anterior bone segment by an orthodontic force.

[An epidemiological study of malformations in infants delivered from diabetic mothers]

The purpose of this study is to investigate the risks of delivery of malformed infants in diabetic mothers in comparison with those in non-diabetic mothers and to clarify risk factors for malformation due to maternal diabetes. The delivery records available at the Department of Obstetrics and Gynecology, Mie University School of Medicine between 1979 and 1992 showed 103 mothers with diabetes mellitus among 4,353 pregnancies. The incidence of malformation in infants born to diabetic mothers was 9.7%, and it was 2.5% overall. By logistic regression analysis of all mothers in this series, diabetes as well as maternal age, and fetal age were shown to be significant risk factors for malformation. A further logistic model for diabetic mothers revealed that a younger age of the mother at the time of labour, low fetal age, older age at onset of diabetes, previous history of pregnancies, and an Hemoglobin A1 (HbA1) level higher than 9% were independent risk factors, among which HbA1 (>9%) showed the highest odds ratio of 24. Careful management is therefore needed to reduce the risk of malformation in pregnancy of diabetic mothers.

Cytogenetic analyses of hepatocellular carcinoma by in situ hybridization with a chromosome-specific DNA probe

BACKGROUND

Numerical chromosome analysis has been established in solid tumors by using in situ hybridization (ISH) with a chromosome-specific probe. We analyzed human hepatocellular carcinoma (HCC) by ISH for chromosome 17 and investigated the correlation of its copy number with histologic malignancy, proliferative activity, p53 mutation, and DNA ploidy.

METHODS

Chromosome 17 was hybridized with a pericentromere-specific DNA probe directly on the tumor cells isolated from paraffin blocks of 25 surgically resected HCCs. Proliferative activity was measured by Ki-67 immunohistochemistry, p53 mutation was analyzed by p53 immunohistochemistry, and DNA ploidy was estimated by cytofluorometry.

RESULTS

Forty-four percent of the 25 HCCs showed numerical abnormality of chromosome 17. Many disomic cases had a less malignant histology, whereas many polysomic cases had a more malignant histology. The Ki-67 positive index of polysomic cases was higher than that of disomic cases. In 22 cases (88.0%), the copy number of chromosome 17 was well matched with DNA ploidy. However, the numerical abnormality of chromosome 17 did not show a significant correlation with p53 mutation. Two of four HCCs that showed histologic heterogeneity were also heterogenous on ploidy pattern and the copy number of chromosome 17. Conversely, there was one case in which only ISH could demonstrate heterogeneity, although the other features exhibited homogeneity.

CONCLUSIONS

Numerical chromosome abnormalities correlated with the increase of histologic malignancy proliferative activity, and DNA ploidy. Moreover, ISH analysis was useful in assessing the intratumoral heterogeneity in HCC, especially when current methods failed to detect it. Thus, ISH provides information on important biologic features, such as malignant potential and intratumoral heterogeneity, in HCC.

Interleukin (IL)-1 beta, IL-6, tumor necrosis factor-alpha, epidermal growth factor, and beta 2-microglobulin levels are elevated in gingival crevicular fluid during human orthodontic tooth movement

Bone remodeling is a complex process regulated by several mediators. Recent work has revealed that cytokines and growth factors have significant effects on bone cell metabolism. However, little information is available concerning the production of cytokines during orthodontic tooth movement in human subjects, and there is no non-invasive model for determining the production of cytokines. Therefore, the purpose of this study was to identify and quantify the various cytokines in human gingival crevicular fluid (GCF), and to investigate the changes in their levels during orthodontic tooth movement. Twelve patients (mean age, 14.4 years) were used as subjects. An upper canine of each patient having one treatment for distal movement served as the experimental tooth, whereas the contralateral and antagonistic canines were used as controls. The GCF around the experimental and the two control teeth was taken from each subject immediately before activation, and at 1, 24, and 168 hr after the initiation of tooth movement. Cytokine levels were determined by ELISAs. The concentrations of interleukin (IL)-1 beta, IL-6, tumor necrosis factor-alpha, epidermal growth factor, and beta 2-microglobulin were significantly higher in the experimental group than in the controls at 24 hr after the experiment was initiated. All the cytokines remained at baseline levels throughout the experiment for the two control groups. In contrast to cytokine alteration, the amount of total protein in the GCF exhibited a gradual increase, but no significant difference was observed between the control and experimental groups. Since all cytokines in GCF play an important role in the bone remodeling processes in vitro, the present results indicate that the changes in cytokines in GCF are associated with orthodontic tooth movement.

Cytodifferentiation of the odontoclast prior to the shedding of human deciduous teeth: an ultrastructural and cytochemical study

BACKGROUND

In human deciduous teeth, odontoclastic resorption takes place at the pulpal surface of the coronal dentine prior to shedding, and this resorption shows clear time-related histological changes (Sahara et al., 1992).

METHODS

Using this phenomenon as an observation system, we examined the cytodifferentiation of human odontoclasts by light and electron microscopy. For a histochemical marker of odontoclast differentiation and function, tartrate-resistant acid phosphatase (TRAP) activity was determined by light and electron microscopic enzyme histochemistry.

RESULTS

As root resorption neared completion, TRAP-positive mononuclear cells were initially detected in the pulp chamber. They had abundant mitochondria, small lysosomes, and moderately developed rough endoplasmic reticulum throughout their cytoplasm. In these mononuclear cells, TRAP activity was localized in compartments of the biosynthetic pathway, i.e., in cisternae of the endoplasmic reticulum and Golgi lamellae, as well as small lysosomes. The TRAP-positive mononuclear cells first made contact with the predentine surface by their elongated cellular processes. After attachment, they spread out along the predentine surface and developed specialized membrane structures, clear zones, and ruffled borders. Next, they fused with each other on the predentine surface and formed typical multinucleate odontoclasts. After termination of their resorption function, the odontoclasts lost their ruffled borders and became detached from the resorbed surface. Most of the detached odontoclasts had numerous large pale vacuoles and secondary lysosomes and appeared to be in the process of degeneration.

CONCLUSIONS

The present study demonstrates that: (1) odontoclasts differentiated from TRAP-positive mononuclear cells, which presumably originate from circulating progenitor cells, (2) membrane specialization of odontoclasts, i.e., development of a clear zone and ruffled border, is induced following their contact with the resorption surface, (3) multinucleation of odontoclasts takes place only after their attachment to the resorption surface, (4) mature multinucleate odontoclasts can resorb predentine as well as dentine in the same way as osteoclasts resorb bone, and (5) at the end of the resorption, odontoclasts gradually lose their ruffled borders and become detached from the resorbed surface.

Expression of estrogen receptor in diseased human prostate assessed by non-radioactive in situ hybridization and immunohistochemistry

To understand the role of estrogen in the pathogenesis of benign prostatic hyperplasia, expressions of estrogen receptor (ER) mRNA and ER protein by in situ hybridization and by immunohistochemistry, respectively, were investigated in human prostatic tissues. In non-malignant region, ER mRNA and ER protein were found in cytoplasm and nucleus, respectively, of stromal cells, but not in glandular epithelial and basal cells. In benign regions, ER mRNA/ER protein positive cells were found in fibromyoadenomatous and myoadenomatous hyperplasia, but not in adenomatous hyperplasia. A striking feature was periacinar arrangement of ER mRNA/ER protein positive stromal cells in all prostate carcinoma treated with androgen withdrawal. The ER mRNA/ER protein positive cells were immunohistochemically identified as fibroblasts, myoblasts, and smooth muscle cells. These results indicate that stromal cells are the primary target of estrogen in prostate, and that androgen withdrawal upregulates the expression of ER gene.

Identification of apoptotic hepatocytes in situ in rat liver after lead nitrate administration

Apoptosis plays a major role in the regression of mitogen (lead nitrate)-induced hepatic hyperplasia. We compared the in situ end-labeling (ISEL) technique with the conventional detection of apoptotic bodies in this process. In hematoxylin and eosin (H&E) sections, apoptosis is usually recognizable by the presence of apoptotic bodies (apoptosis phase 2). Although the early phase of apoptosis (apoptosis phase 1) can be detected as a prekaryorrhectic appearance in H&E sections, it is difficult to detect and is easily overlooked. On the other hand, ISEL presents intense staining mainly in phase 1 and weak or negative staining in phase 2. Thus, simultaneous investigation by these two methods in two serial sections is the most reliable way to calculate the incidence of apoptosis and gives us precise information on the stages of apoptosis in situ. Since the colorized signals of ISEL are much easier to detect than apoptotic bodies in H&E sections, ISEL is particularly useful for liver tissues, where the incidence of apoptosis is low.

Immunohistochemical study on choline acetyltransferase in the spinal cord of patients with amyotrophic lateral sclerosis

The authors developed a polyclonal antibody against a fusion protein containing 598 amino acids from a human choline acetyltransferase (ChAT) cDNA and 12 amino acids derived from an expression vector, and examined immunohistochemical reactivity for ChAT in large motor neurons (30 microns and more in somal minimal diameter) of the lumbar spinal cords of four patients with amyotrophic lateral sclerosis (ALS) and of four control cases. In controls, the number of large neurons included in the tissue with a total thickness of 100 microns ranged from 74 to 105 (average 87). About 60-90% (average 80%) of the neurons were positively stained in their perikarya with an anti-human ChAT antibody. In the cases of ALS, the number of large motor neurons was greatly reduced (25-60, average 38). About 4-13% (average 8%) were positively stained. These results indicate that not only large neurons are reduced in number, but also their positivity for ChAT is decreased in the anterior horn of ALS spinal cord.

Expression of c-myc in altered hepatic foci induced in rats by various single doses of diethylnitrosamine and promotion by 0.05% phenobarbital

Among the proto-oncogenes examined by northern blot analysis, c-myc, c-Ha-ras, c-fos, and c-raf-1 have been reported to be activated in rat liver cell carcinomas. However, there are relatively few reports on protooncogene expression in altered hepatic foci (AHF) early during hepatocarcinogenesis in the rat. In this study, diethylnitrosamine (DEN) at doses ranging from 10 to 200 mg/kg was used to initiate and phenobarbital (0.05%) to promote AHF in rats. AHF were detected by the presence of the marker enzymes glutathione s-transferase, placental form (GST-P); gamma-glutamyltranspeptidase (GGT); glucose-6-phosphatase (G6Pase); and canalicular adenosine triphosphatase (ATPase). Proto-oncogene expression in individual AHF was investigated by in situ hybridization (ISH). ISH for the mRNAs of c-Ha-ras, c-fos, and c-raf-1 revealed little or no expression in AHF. However, the levels of c-myc mRNA were increased in about 10% of the AHF initiated by the highest dose of DEN (200 mg/kg). Thus, altered expression of proto-oncogenes was not seen in AHF initiated by nonnecrogenic doses of DEN and promoted by phenobarbital. However, at the necrogenic dose of 200 mg/kg DEN, c-myc expression was found mostly in AHF in which abnormal expression of GST-P, GGT, G6Pase, and ATPase was also present, indicating that c-myc expression is correlated with phenotypically greater complexity of the AHF, a characteristic of malignant hepatic neoplasms in the rat.

Evidence for the lack of hepatic N-acetyltransferase in suncus (Suncus murinus)

The abilities of liver cytosol fractions from the suncus and Sprague-Dawley (SD) rats to N-acetylate aniline, p-aminobenzoic acid, p-aminosalicylic acid and 2-aminofluorene (AF) were compared. The cytosol from rats N-acetylated these substrates at efficient rates, whereas the cytosol from the suncus did not N-acetylate these substrates at detectable rates. When AF was given to the suncus, 2-acetylaminofluorene (AAF), a metabolite of AF formed by N-acetyltransferase (NAT), was not detectable in serum, whereas the metabolite was seen clearly in rats. Northern blot and Southern blot analyses, using cDNAs coding for human NATs as probes, indicated that not only the transcripts but also the genes of the enzymes were undetectable in suncus. These results suggest that the suncus is among the few species known to lack NATs.

[A case report of prostate cancer resistant to endocrine therapy successfully treated with intra-arterial chemotherapy]

A 73-year-old male with low abdominal pain on urination and frequent urination was diagnosed as poorly differentiated adenocarcinoma of prostate. He received endocrine therapy with DESD and bilateral orchiectomy. This treatment was not effective, so he was given intra-arterial infusion chemotherapy with MTX, ADM and CDDP using the reservoir system. After 2 courses of this chemotherapy the regression rate was 75%, and the pathological examination after the chemotherapy revealed no cancer cells. There is no established chemotherapy for prostate cancer at present. Thus this case is very suggestive for the treatment of prostate cancer.

Comparison of different bonding materials for laser debonding

The laser-aided removal of ceramic brackets from enamel surfaces was compared between two different adhesives. The selected bonding materials were Bis-GMA composite resin and 4-META MMA resin. Debonding forces were measured as the shear bond strength, perpendicular to the brackets. Debonding force, debonding time, total illuminated laser energy, and Modified Adhesive Remnant Index were discussed. Laser illumination was very effective for debonding in both resin groups. Enamel fracture was not observed in either laser illuminated groups, whereas two teeth were cracked in the Bis-GMA control group. For MMA resin, debonding force was sufficiently decreased at 3 watts output, whereas 7 watts output was needed for Bis-GMA resin samples. Total illuminated energies until the removal of the brackets were statistically lower in the MMA groups than in the Bis-GMA groups. Laser-focused adhesives tended to be removed with the brackets in the Bis-GMA groups, whereas they tended to remain on the tooth surface in the MMA groups. We concluded that debonding MMA resin with a laser is safer than debonding Bis-GMA resin with a laser.

High-performance liquid chromatographic determination of prolylcarboxypeptidase activity in monkey kidney

A simple HPLC procedure for the determination of prolylcarboxypeptidase activity in monkey kidney was established with Cbz-Pro-Ala used as substrate. Decrease of the substrate and increase of the product were stoichiometrically related to each other. Heat treatment at 60 degrees C freed the enzyme preparation of contaminating activities. Data on substrate specificity and influence of inhibitors suggested this method was sensitive for the determination of prolylcarboxypeptidase without the use of a radioactive substrate.

Listener adaptive characteristics of vowel devoicing in Japanese dialogue

Listener adapative characteristics of Japanese vowel devoicing were investigated by analyzing (i) dialogues between professional teachers and hearing-impaired (HI) or normal-hearing (NH) children, and (ii) speech samples read by the teachers as fast and clearly as possible (RD). The teachers reduced the devoicing rate and lengthened the moras more in the HI vs NH samples, and even more in the HI vs RD samples. A logistic regression analysis of the devoicing rate suggests that the speech rate dependency of the devoicing rate is different among the HI, NH, and RD samples. When moras are lengthened, the predicted devoicing rate decreases more for the HI vs NH samples, and even more in the HI vs RD samples, suggesting that not only rate-dependent adjustments but also rate-independent adjustments significantly affect devoicing reduction. These results suggest the following: (1) Professional teachers of hearing-impaired children reduce their devoicing not only by lengthening the interval of successive voicing/devoicing gestures, but also by resizing component gestures to some extent, probably to improve the listener's comprehension; (2) vowel devoicing should be represented in terms of parameters of speech motor control; (3) it may be possible to develop an optimized communication method for hearing-impaired children by simulating such listener-adaptive adjustments in speech production.

Antihypertensive properties of a new long-acting angiotensin converting enzyme inhibitor in renin-dependent and independent hypertensive models

The antihypertensive properties of a new long-acting, angiotensin-I-converting enzyme (ACE) inhibiting agent, (2S,3aS,7aS)-1-(N2-nicotinoyl-L-lysyl-gamma-D-glutamyl) octahydro-1H-indole-2-carboxylic acid (CAS 116662-73-8, DU-1777), were investigated orally in various experimental models of hypertension in comparison to a standard ACE inhibitor, lisinopril. The hypotensive potency of DU-1777 was not as marked as that of lisinopril in renin-dependent hypertensive models, i.e., two-kidney one-clip renal hypertensive rats (2K-1C RHR) (ED-20mmHg: 3.1 versus 1.0 mg/kg) or two-kidney two-clip renal hypertensive dogs (2K-2C RHD) (ED-20 mmHg: 2.5 versus 1.0 mg/kg), though the actions of the two drugs were both long-lasting and dose-related. When spontaneously hypertensive rats (SHR) were used, however, DU-1777 was as active as lisinopril (ED-20 mmHg: 17.9 versus 13.6 mg/kg). The most distinguishing results with DU-1777 were its hypotensive effects in renin-independent hypertensive models. In contrast to lisinopril, the drug produced a sustained and dose-related hypotensive effect in DOCA salt hypertensive rats (DOCA-HR) and one-kidney one-clip renal hypertensive rats (1K-1C RHR). There exists an inconsistency between the long duration of the agent's hypotensive action in all tested hypertensive models and its short duration of ACE inhibiting activity as demonstrated both in vivo and ex vivo. The sustained antihypertensive action of DU-1777 cannot be reasoned solely with respect to ACE inhibition, suggesting some additional mechanisms of action yet to be defined.

Simultaneous expression of human CYP3A7 and N-acetyltransferase in Chinese hamster CHL cells results in high cytotoxicity for carcinogenic heterocyclic amines

To investigate whether several food-derived heterocyclic amines are activated to genotoxic products in human fetal livers, cell lines stably expressing CYP3A7, a human fetus-specific form of cytochrome P450, NADPH-cytochrome P450 reductase, and human monomorphic or polymorphic N-acetyltransferase (NAT1 or NAT2) were established. The expression of CYP3A7 mRNAs and proteins was determined by RNA blot and immunoblot analyses, respectively. The introduction of CYP3A7 cDNA to CR-68 cells which had been transfected with guinea pig NADPH-cytochrome P450 reductase, NAT1, or NAT2 cDNA resulted in increased sensitivity of the cells to aflatoxin B1 compared to parental cells. The cytotoxicity assay for 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ), and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) showed that 7P-145 cells, which expressed the reductase, CYP3A7, and NAT2, were approximately 4-, 30-, and 14-fold more sensitive to respective IQ, MeIQ, and MeIQx than parental CR-68 cells. There were no clear differences in sensitivity to these compounds among CHL, CR-68, and the cells which expressed the reductase and CYP3A7 (7R-54), the reductase and NAT1 (CNM-4), the reductase and NAT2 (CNP-40), and the reductase, NAT1, and CYP3A7 (7M-124). From these results, it was suggested that both CYP3A7 and polymorphic NAT2 are required for mutagenic activation of several heterocyclic amines in human fetal livers.